Title of Invention

INTERNAL COMBUSTION ENGINE WITH FORCED AIR COOLING

Abstract To efficiently cool an ignition plug in an internal combustion engine with forced air cooling in which a cylinder block and cylinder head from which cooling fins project are covered with a shroud forming a cooling air path between the shroud and the cylinder block and cylinder head. A cooling fan for ventilating cooling air aspirated from outside the shroud toward the cooling air path is associated with and coupled to a crankshaft with an air outlet for discharging the cooling air flowing through the cooling air path to the outside being provided to the shroud. A notched space is formed to a part of a periphery of the cylinder block by partially shortening or removing the cooling fins projecting from the periphery of the cylinder block. A first projection projecting inwardly along the notched space and a second projection projecting inwardly at a position where an ignition plug is between the second projection and first projection are formed to the shroud.
Full Text

INTERNAL COMBUSTION ENGINE WITH FORCED AIR COOLING
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a internal combustion engine with forced air cooling in which a cylinder block which is joined with a crankcase rotatably receiving a crankshaft and from which cooling fins project. A cylinder head is joined with the cylinder block with an ignition plug attached thereto. A shroud forms a cooling air path between the shroud and the cylinder block and cylinder head. A cooling fan is provided for ventilating cooling air aspirated from outside the shroud toward the cooling air path which is associated with and coupled to the crankshaft. An air outlet is provided for exhausting the cooling air flowing through the cooling air path that is formed to the shroud.
Description of Background Art [0002] An internal combustion engine with forced air cooling is disclosed in JP-A No. H7-332084. In this intemal combustion engine with forced air cooling, an air outlet is provided to a shroud covering a cylinder block and a cylinder head, near the cylinder block and cylinder head to thoroughly cool the cylinder block and cylinder head.
[0003] Cooling is needed particularly around an ignition plug, but the ignition plug is far from the air outlet in JP-A No. H7-332084. The ignition plug needs to be cooled

more efficiently.
[0004] An international combustion engine mounted on, for example, a scooter-type
motorcycle is disposed inside body covers which cover a front portion and side
portions of the intemal combustion engine, so that it is difficult to use a flow of air
caused by operating the vehicle to cool the intemal combustion engine.
[0005] To address such a problem, configurations have been proposed in which a
cylinder and a cylinder head of an intemal combustion engine are covered by a shroud
configured such that air sucked in by a cooling fan is guided to flow around the
cylinder and the cylinder head so as to forcedly cool the intemal combustion engine.
See, for example, JP-A No. H07-026533,
[0006] In the international combustion engine with forced air cooling disclosed in
JP-A No. H07-026533, a shroud surrounding a cylinder and a cylinder head includes a
right shroud covering right side portions of the cylinder and the cylinder head. The
right shroud extends rearwardly from the right side and is linked to a fan cover
covering a cooling fan provided at a right end portion of a crankshaft.
[0007] The shroud also includes a left shroud covering left side portions of the
cylinder and the cylinder head with an exhaust duct extending downwardly from the
left shroud.
[0008] In the configuration, cooling air sucked in by rotation of the cooling fan in an
approximately horizontal leftward direction is led diagonally forwardly by the right
shroud and then changes the flow direction to flow leftwardly around the cylinder and
the cylinder head thereby cooling them. The air having cooled the cylinder and the
cylinder head changes the flow direction downwardly by hitting the left shroud to be
then discharged from the exhaust duct to the outside.
[0009] As described above, the shroud described in the JP-A No. H07-026533 is
configured such that the cooling air having cooled the cylinder and the cylinder head

by flowing in a horizontal leftward direction perpendicularly changes its flow direction by hitting the left shroud to be then downwardly exhausted from the exhaust duct. In such a configuration, the air flow may become locally stagnant in internal comers of the left shroud and the air flow resistance is high, so that the cooling air flow rate is not likely to increase.
SUMMARY AND OBJECTS OF THE INVENTION [0010] In view of the circumstances, an object of an embodiment of the present invention is to provide an internal combustion engine with forced air cooling for cooling an ignition plug efficiently.
[0011] To achieve the above object according to an embodiment of the present invention, an internal combustion engine with forced air cooling is provided wherein a cylinder block is joined with a crankcase rotatably receiving a crankshaft and from which cooling fins project. A cylinder head is joined with the cylinder block with an ignition plug being attached thereto. A shroud forming a cooling air path between the shroud and the cylinder block and cylinder head is provided. A cooling fan for ventilating cooling air aspirated from outside the shroud toward the cooling air path is associated with and coupled to the crankshaft. An air outlet for discharging the cooling air having flowed through the cooling air path is formed to the shroud. A notched space is formed to a part of a periphery of the cylinder block by partially shortening or removing the cooling fins projecting from the periphery of the cylinder block. A first projection projecting inward along the notched space and a second projection projecting inward at a position where the ignition plug attached to one side of the cylinder head is between the second projection and first projection are formed to the shroud. [0012] According to an embodiment of the present invention, the air outlet is

provided to the shroud to be adjacent to an exhaust pipe which communicates with an exhaust port provided to the cylinder head and which is connected to the cylinder head. [0013] According to an embodiment of the present invention, the notched space is formed to the periphery of the cylinder block, the periphery being on a side corresponding to an inlet port provided to the cylinder head.
[0014] According to an embodiment of the present invention, the air outlet and second projection are formed to one of a pair of sides of the shroud, the pair of sides being disposed to opposing sides of a plane including an axis of the ignition plug, such that a portion corresponding to the ignition plug is between the air outlet and second projection.
[0015] According to an embodiment of the present invention, the first projection and second projection are offset from each other in the direction along the plane including the axis of the ignition plug when viewed from the direction along the cylinder axis. [0016] According to an embodiment of the present invention, the ignition plug is attached to the cylinder head while being tilted toward the cooling fan. [0017] According to an embodiment of the present invention, cooling air ventilated by the cooling fan is discharged from an air outlet. First and second projections are formed to a side of a shroud such that an ignition plug is between the projections. Accordingly, the cooling air flowing toward the air outlet can be efficiently introduced around the ignition plug by the first and second projections to cool the ignition plug efficiently. Additionally, since the first projection projects inwardly along a notched space formed to a periphery of a cylinder block, an amount of cooling air flowing around a cylinder head having a higher temperature can be increased. [0018] According to an embodiment of the present invention, since the air outlet is disposed adjacent to an exhaust pipe, efficient cooling can be done around an exhaust port, which tends to have a high temperature.

[0019] According to an embodiment of the present invention, since the first projection is formed to a side of the shroud, the side corresponding to an inlet port, an amount of cooling air flowing around the inlet port having a relatively low temperature can be reduced, and an amount of cooling air flowing around the ignition plug and the exhaust port can be increased by the reduction.
[0020] According to an embodiment of the present invention, the air outlet and second projection are formed to one of a pair of sides of the shroud, the pair of sides being disposed to opposing sides of a plane including an axis of the ignition plug, such that a portion corresponding to the ignition plug is between the air outlet and second projection. Accordingly, a path for the cooling air flowing around the ignition plug to the air outlet and a path for the cooling air flowing through the other side of the pair to the air outlet can be positively formed.
[0021] According to an embodiment of the present invention, the first projection and second projection are offset from each other in the direction along the plane including the axis of the ignition plug. Accordingly, a path area for the cooling air flowing from around the cylinder block to around the cylinder head can be secured. Thus, the cooling air can be collected around the ignition plug without reducing the amount of the total cooling air.
[0022] According to an embodiment of the present invention, the ignition plug is made closer to the cooling fan, so that the ignition plug can be cooled by the cooling air having a lower temperature.
[0023] The present invention has been made in view of the above situation, and it is an object of an embodiment of the present invention to provide an internal combustion engine with forced air cooling having a shroud configured to make cooling air for cooling portions to be cooled of the internal combustion engine flow unidirectionally and smoothly at a low air flow resistance to achieve a high cooling effect.

[0024] To achieve the above object, according to an embodiment of the present invention an intemal combustion engine with forced air cooling includes a power unit having an intemal combustion engine with a forwardly tilted cylinder, a power transmission mechanism rearwardly extending from the intemal combustion engine, and a rear wheel joumaled to a rear portion of the power transmission mechanism which are unitedly and swingably supported by a vehicle body frame with a shroud surrounding the cylinder and a cylinder head of the intemal combustion engine. A cooling fan is driven by rotation of a crankshaft which sucks in outside air from a neighborhood of the crankshaft into the shroud to cool the cylinder and the cylinder head. An air cleaner is provided above a crankcase of the intemal combustion engine. In the intemal combustion engine with forced air cleaning the air cleaner has a cleaner air intake port provided above an axis of the cylinder with the shroud having a cooling air intake port formed on a side of the crankcase. A cooling air outlet port is formed in a side wall opposing another side wall where the cooling air intake port is formed with an air exhaust duct extending from the cooling air outlet port being located below the cylinder axis as seen in a side view while being located, as seen in a vehicle width direction, approximately outside the air cleaner and inside an outer surface of a transmission case cover covering the power transmission mechanism. [0025] According to an embodiment of the present invention, an air intake duct for taking outside air into the transmission case cover is provided with the air intake duct having an air intake port provided above the cylinder axis.
[0026] According to an embodiment of the present invention, the air intake port of the air intake duct is provided between the cleaner air intake port and the air exhaust port as seen in the vehicle width direction.
[0027] According to an embodiment of the present invention, the air intake duct and the cleaner air intake port are disposed to overlap with each other as seen in a side

view.
[0028] According to an embodiment of the present invention, the air exhaust duct extends rearwardly along a lower end surface of the air intake duct to outside a vehicle body cover. The air exhaust duct having a rear-end air exhaust port which is opened rearwardly.
[0029] According to an embodiment of the present invention, the shroud surrounding the cylinder and cylinder head has a cooling air outlet port formed in a side wall opposing another side wall in which a cooling air inlet port is formed. Therefore, the cooling air sucked in the shroud flows from the cooling air inlet port to the cooling air outlet port unidirectionally, evenly and smoothly to be discharged from the exhaust duct without locally stagnating in the shroud. As a result, portions to be cooled of the cylinder and cylinder head of the internal combustion engine can be cooled evenly and efficiently by the cooling air flowing at a low flow path resistance and at a high flow rate. Thus, a great cooling effect can be expected.
[0030] Furthermore, the cleaner air intake port of the air cleaner provided above the crankcase is provided above the axis of a forwardly tilted cylinder as seen in a side view, and the air exhaust duct is provided below the cylinder axis. Therefore, the engine cooling air discharged, at a high temperature from the air exhaust port of the air exhaust duct can be prevented from being sucked into the cleaner air intake port provided above the cylinder axis. This can prevent the temperature of the intake cooling air from rising.
[0031] Still furthermore, the air exhaust duct has an air exhaust port provided below the cylinder axis while being located, as seen in a vehicle width direction, outside the air cleaner and inside an outer surface of the transmission case cover covering the power transmission mechanism. Therefore, the air exhaust duct can be made small and can be installed compactly.

[0032] According to an embodiment of the present invention, the air intake duct for taking outside air into the transmission case cover has an air intake port provided above the cylinder axis. Therefore, the engine cooling air discharged, at a high temperature, from the air exhaust port of the air exhaust duct provided below the cylinder axis can be prevented from being sucked into the air intake port. [0033] According to an embodiment of the present invention, the air intake port of the air intake duct is provided between the cleaner air intake port and the air exhaust port as seen in the vehicle width direction. Therefore, if the engine cooling air exhausted from the air exhaust port flows upwardly, for example, when the vehicle is stopped, the exhaust air is led to the nearer air intake port, so that the exhaust air is prevented from reaching and being sucked into the farther cleaner air intake port. This can prevent the intake air temperature from rising.
[0034] According to an embodiment of the present invention, the air intake duct and the cleaner air intake port are disposed to overlap with each other as seen in a side view, so that the air intake duct serves as a guard to further prevent the engine cooling air exhausted from the air exhaust port from being sucked into the cleaner air intake port. The air intake duct can also prevent foreign matter from entering the cleaner air intake port.
[0035] According to an embodiment of the present invention, the air exhaust duct extends, rearwardly along a lower end surface of the air intake duct, to outside a vehicle body cover, the air exhaust duct having a rear-end air exhaust port which is opened rearwardly. Therefore, the engine cooling air discharged from the air exhaust port is not held inside the body cover. The flow of air caused by operating the vehicle and flowing rearwardly along the lower-end surface of the transmission case cover particularly applies a negative pressure to the engine cooling air. This all the more promotes discharging of the engine cooling air, increases the flow rate of the engine

cooling air, and improves the cooling effect.
[0036] Furthermore, the air exhaust duct extends rearwardly along a lower-end
surface of the air intake duct without causing the air exhaust duct to bulge to the sides.
This improves the external appearance of the internal combustion engine.
[0037] Further scope of applicability of the present invention will become apparent
from the detailed description given hereinafter. However, it should be understood
that the detailed description and specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the invention will become
apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS [0038] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0039] FIG. 1 is a left side of a scooter motorcycle;
[0040] FIG. 2 is an enlarged cross section view taken from line 2-2 of FIG 1; [0041] FIG 3 is an enlarged cross section view taken from line 3-3 of FIG. 1; [0042] FIG. 4 is a view along arrow 4 of FIG 2; [0043] FIG. 5 is a view along arrow 5 of FIG. 2; [0044] FIG. 6 is a view along arrow 6 of FIG 4;
[0045] FIG 7 is a view of a lower cover member of a shroud viewed from arrow 7 of FIG 6;
[0046] FIG 8 is a view of an upper cover member of the shroud viewed from arrow 8 of FIG 6;

[0047] FIG. 9 is a cross section view taken from line 9-9 of FIG 8;
[0048] Fig. 10 is an overall side view of a scooter-type motorcycle according to an
embodiment of the present invention;
[0049] Fig. 11 is a side view of a power unit of the scooter-type motorcycle;
[0050] Fig. 12 is a plan view of the power unit of the scooter-type motorcycle;
[0051] Fig. 13 is a front view of the power unit of the scooter-type motorcycle;
[0052] Fig. 14 is a cross-sectional view taken along line V - V in Fig. 11;
[0053] Fig. 15 is a cross-sectional view taken along line VI - VI in Fig. 14;
[0054] Fig. 16 is a cross-sectional view taken along line VII - VII in Fig. 11;
[0055] Fig. 17 is a side view of a transmission case cover;
[0056] Fig. 18 is a left side view of an inner wall member of an air intake duct;
[0057] Fig. 19 is a right side view of the inner wall member of the heel guide
member;
[0058] Fig. 20 is a cross-sectional view taken along line VII - VII in Fig. 19;
[0059] Fig. 21 is a left side view of an outer wall cover member of the air intake
duct;
[0060] Fig. 22 is a right side view of the outer wall member of the heel guide
member;
[0061] Fig. 23 is a cross-sectional view taken along line XIV - XIV in Fig. 22;
[0062] Fig. 24 is a right side view of the air intake duct wherein the inner wall
member and the outer wall cover member are united; and
[0063] Fig. 25 is a cross-sectional view taken along line XV - XV in Fig. 24.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0064] Modes of the present invention are explained below in accordance with one embodiment of the present invention in reference to the appended drawings.

[0065] As illustrated in FIG. 1, a body frame 15 of the scooter motorcycle includes a head pipe 18 steerably receiving a front fork 16 to which a front wheel WF is joumaled with a steering handlebar 17 coupled to the front fork 16. A down tube 19 extends rearwardly and downwardly from the head pipe 18. A left and right pair of lower frame pipes 20 with front ends that are respectively fixed to both lower sides of the down tube 19 extend rearwardly. A left and right pair of rear frame pipes 21 are integrally connected to the rear ends of the lower frame pipes 20. Each of the rear frame pipes 21 includes a rise frame portion 21a extending rearwardly and upwardly from the rear end of each of the lower frame pipe 20 and an upper frame portion 21b extending rearwardly from the rear end of the rise frame portion 21a almost horizontally. The rear portions of the rear frame pipes 21 are coupled to each other. [0066] A bracket 22 is provided to an integrally-connected portion of the lower frame pipes 20 and rear frame pipes 21 in the body frame 15. A front portion of a power unit P is vertically-pivotally received by the bracket 22 via a link mechanism 23. A rear wheel WR disposed to the right rear portion of the power unit P is joumaled to the rear portion of the power unit P. A rear shock absorber 24 is provided between the rear portion of the left rear frame pipe 21 of the rear frame pipes 21 and the rear portion of the power unit P.
[0067] In front of the power unit P, a fuel tank 25 is disposed between, and supported by the lower frame pipes 20. A storage box 26 is disposed above the power unit P, and supported by the rear frame pipes 21.
[0068] The body frame 15 is covered with a body cover 27 made of synthetic resin. The body cover 27 includes a leg shield 28 shielding the front of legs of a rider with a step floor 29 connected to the lower portion of the leg shield 28 to cover the fuel tank 25. A side cover 30 is connected to the step floor 29 to cover the rear portion of the body from the both sides. A tandem seat 31 which can be opened and closed which

covers the storage box 26 from above is provided above the side cover 30.
[0069] In FIG 2, the power unit P includes a cylinder four-cycle OHC internal
combustion engine E with forced air cooling disposed in front of the rear wheel WR
and a continuously variable transmission M provided between the intemal combustion
engine E and rear wheel WR.
[0070] An engine body 34 of the internal combustion engine E includes a crankcase
35 rotatably receiving a crankshaft 45 having a rotation axis parallel to a rotation axis of the rear wheel WR; a cylinder block 36 joined with the crankcase 35 and having a sleeve 39 having a cylinder bore 40 in which a piston 41 coupled to the crankshaft 45 slidably fits with a cylinder head 37 joined with the opposite side of the cylinder block
36 to the crankcase 35. Ahead cover 38 is joined with the opposite side of the cylinder head 37 to the cylinder block 36.
[0071] The cylinder block 36, cylinder head 37, and head cover 38 are disposed
between the rear frame pipes 21 of the body frame 15. The cylinder block 36 is
tilted until an axis of the cylinder bore 40 becomes almost horizontal so that the front
of the cylinder block 36 is slightly lifted. Thereafter, the cylinder block 36 is joined
with the crankcase 35.
[0072] A combustion chamber 42 is formed between the cylinder block 36 and
cylinder head 37, and faces the top of the piston 41. The piston 41 is coupled to the
crankshaft 45 via a connecting rod 43 and crank pin 44.
[0073] The crankcase 35 includes a pair of case halves 35a, 35b joined with each
other at a plane including the axis of the cylinder bore 40 and perpendicular to the axis
of the crankshaft 45. The crankshaft 45 is rotatably received between the both case
halves 35a, 35b.
[0074] Also in reference to FIG. 3, an inlet port 47, which can communicate with the
combustion chamber 42, is provided to the upper side surface of the cylinder head 37,

and an exhaust port 48, which can communicate with the combustion chamber 42, is provided to the lower side surface of the cylinder head 37. An inlet valve 49 which opens and closes the intake port 47 and an exhaust valve 50 which opens and closes the exhaust port 48 are provided to the cylinder head 37. The intake valve 49 and exhaust valve 50 are arranged in a substantially V shape projecting on a plane perpendicular to the rotation axis of the crankshaft 45. The intake valve 49 and exhaust valve 50 are biased by springs in the directions of closing the inlet port 47 and the exhaust port 48, respectively An ignition plug 51 facing the combustion chamber 42 is attached to the right side of the cylinder head 37 with the motorcycle facing the traveling direction.
[0075] A valve mechanism 52 for opening and closing the inlet valve 49 and exhaust valve 50 is disposed between the cylinder head 37 and head cover 38. A rotational driving force of the crankshaft 45 is transmitted to a camshaft 53 housed in this valve mechanism 52 via a timing transmission mechanism 55 having a cam chain 54 through a one-half reduction ratio. The cam chain 54 is rotatably housed in a cam chain chamber 56 formed over the cylinder block 36, cylinder head 37, and head cover 38.
[0076] The valve mechanism 52 includes the camshaft 53 rotatably received by the cylinder head 37 to have an axis parallel to the axis of the crankshaft 45 with the camshaft 53 having an inlet cam 101 and an exhaust cam 102. An inlet rocker shaft 103 and exhaust rocker shaft 104 are provided having axes parallel to the camshaft 53, and supported by the cylinder head 37. An inlet rocker arm 105 is pivotally received by the inlet rocker shaft 103 to drive the inlet valve 49 by following the inlet cam 101. An exhaust rocker arm 106 is pivotally received by the exhaust rocker shaft 104 to open and close the exhaust valve 50 by following the exhaust cam 102. [0077] In addition, a decompression device 32 having a decompression cam 33

projecting from a base circle portion 102a of the exhaust cam 102 when the speed of the internal combustion engine E is low, under a predetermined value, is provided to the camshaft 53. The decompression device 32 can open the exhaust valve 50 at a valve closing timing defined by the base circle portion 102a of the exhaust cam 102 when the speed of the internal combustion engine E is under the predetermined value. Accordingly, the exhaust valve 50 opens slightly to reduce a pressure of the combustion chamber 42 slightly, so that cranking torque can be reduced. [0078] An inlet pipe 57 communicating with the inlet port 47 is fastened to the upper side of the cylinder head 37. The inlet pipe 57 is formed to curve arcuately toward the rear of the motorcycle. As shown in FIG 1, the upstream end of the inlet pipe 57 is connected to the downstream end of a carburetor 58 disposed rearwardly of the inlet pipe 57 via a connecting tube 59. The upstream end of the carburetor 58 is connected to an air cleaner 60 disposed to the right side of the rear wheel WR and above the power unit P.
[0079] An exhaust pipe 61 communicating with the exhaust port 48 is connected to the lower side of the cylinder head 37. The downstream end of the exhaust pipe 61 is connected to an exhaust muffler 62 disposed to the right side of the rear wheel WR. [0080] Referring to FIGS. 4 and 5, a transmission case 80 extending to the left of the rear wheel WR is coupled to the crankcase 35 with the motorcycle facing the traveling direction. The transmission case 80 includes a case body 81 integrally provided to the case half 35b of the crankcase 35 and extending rearwardly with a left cover 82 fastened to the left side of the case body 81 to form a first transmission chamber 84 between the left cover 82 and the case body 81. A right cover 83 is fastened to the left side of the case body 81 to form a second transmission chamber 85 between the right cover 83 and the case body 81. [0081] In front of the case body 81 in the transmission case 80, a support arm 86 is

disposed to the side of the cylinder block 36 in the internal combustion engine E in a projecting manner. The support arm 86 is pivotally supported by the bracket 22 of the body frame 15 via the link mechanism 23.
[0082] An axle 87 of the rear wheel WR is rotatably received by the rear portion of the case body 81 in the transmission case 80 and by the right cover 83. The rear shock absorber 24 is provided between the rear portion of the case body 81 and an upper frame 21a in the rear frame pipe 21 on the left side in the body frame 15. [0083] The continuously variable transmission M uses a V belt, and is housed in the first transmission chamber 84. A reduction gear train 88 is provided between the continuously variable transmission M and axle 87.
[0084] The continuously variable transmission M is well known, and includes a drive pulley 89 coupled to the other end of the crankshaft 45 outside the crankcase 35 with a driven pulley 92 mounted, via a centrifugal clutch 91, to a driven shaft 90 which has an axis parallel to the crankshaft 45 and which is rotatably received by the rear portion of the case body 81 and by the right cover 83. An endless V belt 93 is wrapped around the drive pulley 89 and driven pulley 92.
[0085] Thereafter, the drive pulley 89 operates to increase a contact radius between the drive pulley 89 and the V belt 93 as multiple weight rollers 95 housed between a ramp plate 94 fixed to the crankshaft 45 and the drive pulley 89 in a floating state move in the radius direction of the crankshaft 45 in response to the increase of the speed of the crankshaft 45.
[0086] On the other hand, the driven pulley 92 operates to decrease a contact radius between the driven pulley 92 and the V belt 93 as a contact radius between the drive pulley 89 and the V belt 93 increases. Accordingly, a continuously variable transmitting is done in accordance with the speed of the crankshaft 45 between the crankshaft 45 and driven shaft 90.

[0087] The reduction gear train 88 is provided between the driven shaft 90 and axle 87 and is housed in the second transmission chamber 85. Rotational power of the driven shaft 90 in the continuously variable transmission M is reduced by the reduction gear train 88, and then transmitted to the axle 87 of the rear wheel WR. [0088] A kick shaft 97 is rotatably received by the left cover 82 in the transmission case 80. A kick pedal 98 (see FIG. 1) is provided to the outer end of the kick pedal 97. Inside the left cover 82, a kick starter 99 which can transmit driving force of the kick shaft 97 to the crankshaft 45 in response to the depression of the kick pedal 98 is provided between the kick shaft 97 and crankshaft 45.
[0089] Referring to FIG 2, an outer rotor 66 of a generator 65 is fixed to one end of the crankshaft 45 outside the crankcase 35. A stator 67 surrounded by the outer rotor 66 is fixed to the crankcase 35. A cooling fan 68 is fixed to the crankshaft 45 outside the generator 65. The cooling fan 68 has multiple blades 68b integrally provided to the periphery of a base 68a fastened to the outer rotor 66 of the generator 65. [0090] In the engine body 34, part of the crankcase 35, the cylinder block 36, and the cylinder head 37 are covered with the shroud 70. Air for forced air cooling discharged from the cooling fan 68 flows through a cooling air path 71 formed between the engine body 34 and shroud 70. To achieve efficient cooling by cooling air flowing through the cooling air path 71, multiple cooling fins 36a and multiple cooling fins 37a project from the outer surfaces of the cylinder block 36 and cylinder head 37 respectively. A notched space 78 is formed to a part of the periphery of the cylinder block 36 by partially shortening or removing the cooling fins 36a projecting from the periphery of the cylinder block 36. In this embodiment, the notched space 78 is formed to the periphery of the cylinder head 36 on the side corresponding to the inlet port 47 provided to the cylinder head 36, namely the portion corresponding to the upper side of the periphery of the cylinder block 36.

[0091] The shroud 70 includes a vertical pair of an upper cover member 72 and a lower cover member 73 joined with each other to cover the cylinder block 36 and cylinder head 37 in cooperation with each other with a fan cover 74 covering part of the crankcase 35 and joined with the cover members 72, 73. The upper cover member 72, lower cover member 73, and fan cover 74 are made of a synthetic resin. [0092] Multiple engaging pawls 108 projecting from a matching surface 107 for the upper cover member 73 to the lower cover member 73 is provided to the upper cover member 72. Locking portions 109 are provided to the lower cover member 73 to achieve a resilient engagement of the engaging pawls 108. Multiple fastening portions 110 and multiple fastening portions 111 abutting on each other at the matching surface 107 are provided to the upper cover member 72 and the lower cover member 73, respectively. The fastening portions 110 and fastening portions 111 abutting on each other are fastened with each other by screw members 112. [0093] By resiliently engaging the engaging pawls 108 with the locking portions 109 and by fastening the fastening portions 111 and fastening portions 112 with each other by use of the screw members 112, the upper cover member 72 and lower cover member 73 are joined with each other. The upper cover member 72 and lower cover member 73 joined with each other are joined with the crankcase 35 of the engine body 34 by use of multiple bolts 113. The head cover 38 forwardly projects from the upper cover member 72 and lower cover member 73.
[0094] The fan cover 74 is joined with the case half 35a to cover the case half 35a, which is part of the crankcase 35, and the cooling fan 68. Then, the fan cover 74 is joined with the upper cover member 72 and lower cover member 73. [0095] An inlet pipe 76 forming an inlet opening 75 for aspirating air from the outside to the cooling fan 68 is provided to the fan cover 74 to correspond to the cooling fan 68 outside the cooling fan 68. A louver 77 is provided to the inlet

opening 76.
[0096] In FIG 1, a flange portion 114 facing the opening end of the exhaust port 48 is provided to the lower side of the cylinder head 37 for the connection of the exhaust pipe 61. An opening 115 whose front has a shape corresponding to the flange portion 114 is provided to the lower cover member 73 of the shroud 70, and extends from the portion corresponding to the flange portion 114 in the posterior direction. With the exhaust pipe 61 being connected to the flange portion 114, an air outlet 116 is formed between the outer surface of the exhaust pipe 61 and the periphery of the opening 115. In other words, the air outlet 116 is provided to the lower cover member 73 of the shroud 70 to be adjacent to the exhaust pipe 61. [0097] The ignition plug 51 whose axis is disposed on a plane including the matching surface 107 of the upper cover member 72 and lower cover member 73 of the shroud 70 is attached to the right side of the cylinder head 37 facing in the traveling direction of the motorcycle On the other hand, the air outlet 116 is formed to one of a pair of sides of the shroud 70, the pair of sides being along a plane including the axis of the ignition plug 51, namely to the lower side of the lower cover member 73 of the shroud 70 in this embodiment.
[0098] In FIGS. 8 and 9, a first projection 72a projecting inwardly along the notched space 78 formed to the periphery of the cylinder block 36 is formed to a side of the shroud 70, the side corresponding to the inlet port 47 of the cylinder head 36, namely to the upper side of the upper cover member 72. A second projection 73a projecting inwardly at a position where the ignition plug 51 attached to the side of the cylinder 37 is between the second projection 73a and first projection 72a is formed to the lower cover member 73 of the shroud 70.
[0099] As designated in FIG. 6, the first projection 72a and second projection 73a are offset from each other in the direction along the axis of the ignition plug 51 when

viewed from the direction along the cylinder axis. The air outlet 116 and second projection 73a are formed to one of a pair of sides of the shroud 70, the pair of sides being disposed to opposing sides of the plane including the axis of the plug 51, namely to the lower side of the lower cover member 73 of the shroud 70 in this embodiment, such that a portion corresponding to the ignition plug 51 is between the air outlet 116 and second projection 73a.
[00100] The ignition plug 51 is attached to the cylinder head while being tilted toward the cooling fan 68. A through opening 117 for enabling the attachment of the ignition plug 51 and for introducing a high tension cord connected to the ignition plug 51 from the shroud 70 to the outside is formed to the matching surface 107 between the upper cover member 72 and lower cover member 73 of the shroud 70. [00101] The operation of this embodiment is explained below. The cylinder block 36 and cylinder head 37 are surrounded by the shroud 70 forming the cooling air path 71 between the shroud 70 and the cylinder block 36 and cylinder head 37. The cooling fan 68 for ventilating the cooling air aspirated from outside the shroud 70 toward the cooling air path 71 is associated with and coupled to the crankshaft 45. The first projection 72a projecting inwardly along the notched space 78 formed to a part of the periphery of the cylinder block 36 by partially shortening or removing the cooling fms 36 projecting from the periphery of the cylinder block 36 and the second projection 73a projecting inwardly at the position where the ignition plug 51 attached to one side of the cylinder head 37 is between the second projection 73a and first projection 72a are formed to the shroud 70.
[00102] The cooling air ventilated by the cooling fan 68 is discharged from the air outlet 116 on the lower side of the lower cover member 73. The first projection 72a and second projection 73a are formed to the side of the shroud 70 such that the ignition plug 51 is between the first projection 72a and second projection 73a.

Accordingly, the cooling air flowing toward the air outlet 116 is efficiently introduced around the ignition plug 51 by the first projection 72a and second projection 73a, so that the ignition plug 51 can be efficiently cooled. Since the first projection 72a projects inwardly along the notched space 78 formed to the periphery of the cylinder block 36, an amount of the cooling air flowing around the cylinder head 37 having a higher temperature can be increased.
[00103] Further, the air outlet 116 is formed to the lower cover member 73 of the shroud 70 to be adjacent to the exhaust pipe 61 which communicates with the exhaust port 48 of the cylinder head 37 and which is connected to the cylinder head 37. Accordingly, efficient cooling can be done around the exhaust port 48, which tends to have a high temperature.
[00104] The projection 72a projecting inwardly is formed to the side of the shroud 70, the side corresponding to the inlet port 47 of the cylinder head 36, namely, to the upper side of the upper cover member 72. Accordingly, an amount of the cooling air flowing around the inlet port 47 having a relatively low temperature can be reduced, and an amount of the cooling air flowing around the ignition plug 51 and exhaust port 48 can be increased by the reduction.
[00105] The air outlet 116 and second projection 73a are formed to one side of the pair of sides of the shroud 70 with the pair of sides being disposed to opposing sides of the plane including the axis of the plug 51, namely to the lower side of the lower cover member 73 of the shroud 70 in this embodiment, such that the portion corresponding to the ignition plug 51 is between the air outlet 116 and second projection 73a. Accordingly, the path for the cooling air flowing around the ignition plug 51 toward the air outlet 116 and the path for the cooling air flowing around the upper cover member 72 toward the air outlet 116 can be positively formed. [00106] The first projection 72a and second projection 73a are offset from each other

in the direction along the axis of the ignition plug 51 when viewed from the direction
along the cylinder axis. Accordingly, the path area for the cooling air flowing from
around the cylinder block 36 to around the cylinder head 37 can be secured. Thus, the
cooling air can be easily collected around the ignition plug 51 while preventing the
reduction of the amount of the total cooling air.
[00107] Further, the ignition plug 51 is attached to the cylinder head 37 while being
tilted toward the cooling fan 68. Accordingly, the ignition plug 51 is made closer to
the cooling fan 68, so that the ignition plug 51 can be cooled by the cooling air having
a lower temperature.
[00108] An embodiment of the present invention will be described below with
reference to Figs. 10 to 25.
[00109] Fig. 10 is a side view of a scooter-type motorcycle according to an
embodiment of the present invention.
[00110] In the following description of the embodiment, the directions front, rear, left,
and right are as seen in the forward direction of the scooter-type motorcycle 201.
[00111] A vehicle body front portion 20IF and a vehicle body rear portion 20IR are
connected to each other via a low floor portion 20IC, and a vehicle body frame
making up a vehicle body skeleton includes a downtube 203 and main pipes 204.
[00112] The downtube 203 extends downwardly from a headpipe 202 included in the
vehicle body front portion IF. The downtube 203 is bent at its lower end portion into a
horizontal direction to further extend rearwardly below the floor portion 201C. The
left and right main pipes 204 are connected to a rear end portion of the downtube 203.
The main pipes 204 extend, from where they are connected to the downtube 203,
rearwardly and upwardly to be then bent at a predetermined height into a horizontal
direction to further extend rearwardly.
[00113] The main pipes 204 support a fuel tank and a storage box with a seat 205

disposed over them.
[00114] The seat 205 is longitudinal in the front-rear direction. It includes a driver
seat 205f formed in a front half portion thereof and a pillion 205r formed rearward of
the driver seat 205f
[00115] The vehicle body front portion 20IF includes a handlebar 206 disposed in an
upper portion thereof and a front fork 207 extending in a lower portion thereof The
handlebar 206 is joumaled to the headpipe 202. A front wheel 208 is journaled to a
lower end portion of the front fork 207.
[00116] A bracket 204a projects at a lower end portion of the rearwardly upwardly
extending main pipes 204. A swing-type power unit 210 is swingably linked to and
supported by the bracket 204a via a link member 209.
[00117] Figs. 11-13 show a side view, a plan view, and a front view of the power unit
10, respectively.
[00118] A single-cylinder, four-stroke internal combustion engine 230 is installed in a
front portion of the power unit 210 with the internal combustion engine 230 being
tilted forward to such an extent that a cylinder block 232 is almost horizontally
positioned. A hanger bracket 210a is forwardly projecting from a lower end portion of
the portion corresponding to the crankcase of a unit case 231. An end portion of the
hanger bracket 210a is linked to the link member 209 via a pivot shaft 209a (see Fig.
10).
[00119] A continuously variable belt-type transmission 235 is configured in an area
ranging from the internal combustion engine 230 to an area rearward of the intemal
combustion engine 230. A rear wheel 221 is joumaled to a speed reduction mechanism
238 provided in a rear portion of the transmission 235.
[00120] A rear shock absorber 222 is disposed between a rear end portion of the unit
case 31 and a rear portion of the main pipes 4.

[00121] A carbureter 224 which is connected to an intake pipe 223 extending from an
upper portion of a cylinder head 233 of the internal combustion engine 230 and an air
cleaner 225 coupled to the carburetor 224 are disposed above the power unit 210.
[00122] A main stand 226 is pivotally attached to the hanger bracket 210a projecting
in a lower portion of the unit case 31.
[00123] Referring to Fig. 10, a front portion and a rear portion of the vehicle body
front portion 201F are covered by a front cover 211 and a rear cover 212, respectively.
A left side and a right side of the vehicle body front portion 20IF are covered by a
front lower cover 213 and a central portion of the handlebar 206 is covered by a
handle cover 214.
[00124] A step plate 215 is installed in the floor portion 201C. The step plate 215
includes a horizontal floor step portion 215f and a pillion step portion 215r extending,
on the left and right sides, rearwardly and upwardly.
[00125] The pillion step portion 215r projects horizontally and laterally so that the
passenger sitting on the pillion 205r can rest, on each side, his or her foot F (shown in
dotted line in Fig. 10) on it.
[00126] A lower side cover 216 extends, below the step plate 215, along the edge on
each side of the step plate 215.
[00127] The vehicle body rear portion 201R is connected to an upper portion of the
pillion step portion 215r of the step plate 215. A body cover 217 covers a portion of
the vehicle body rear portion 201R, the portion extending from a location forward of
the main pipes 204 to left and right sides of the vehicle body rear portion 20IR. An
upper-end opening of the body cover 217 is openably covered by the seat 205.
[00128] As seen in a side view, a rear fender 218 extends rearwardly and downwardly
from a rear portion of the body cover 217 thereby covering the rear wheel 221 from
above, the rear portion of the body cover 217 extending rearwardly and upwardly to

be gradually thinner.
[00129] As seen in a left side view (see Fig. 10), the rear end portions 217e, 215e, and
216e, being successively overlaid, of the body cover 217, step plate 215, and lower
side cover 216 are generally inclined rearwardly. Portions around where the step plate
215 and the lower side cover 216 are fitted to each other of the rear end portions 215e
and 216e project rearwardly. A horizontal portion included in the rearwardly
projecting portion of the rear end portion 215e of the pillion step portion 215r is
designed to be where the passenger rests the heel Fh of his or her foot F.
[00130] An upper portion of the rearwardly projecting portion of the rear end portion
215e of the step plate 215 is shaped to be forwardly concave and continuous with the
rear end portion 217e of the body cover 217, thereby forming a concave 219.
Therefore, when the passenger rests the heel Fh of his or her foot F on the pillion step
portion 215r, there is the uncovered concave 219 on the inside of the heel Fh placed
on the pillion step portion 215r (see Fig. 1).
[00131] Fig. 14 is a cross-sectional view, taken generally along line V - V in Fig. 11,
of the power unit 210.
[00132] The unit swing case 231 includes a left unit case 23IL and a right unit case
23IR which are coupled together. The right unit case 23IR makes up one half part of
a crankcase section. The left unit case 23IL includes a crankcase section 231a which
is longitudinal in the front-rear direction, a transmission case section 231b, and a
reduction gear case section 231c, the three sections being located in a front portion, a
center portion, and a rear portion of the left unit case 23 IL, respectively.
[00133] The left open side of the left unit case 23 IL is covered by a transmission case
cover 236 which is a part of the transmission case. The continuously variable belt-type
transmission 235 is housed in the left unit case 23IL. The right open side of the
reduction gear case section 231c located in the rear portion of the left unit case 23 IL

is covered by the reduction gear case 237. The speed reduction mechanism 238 is
housed in the left unit case 23IL.
[00134] In the so-called crankcase including the crankcase section 231a and the right
unit case 23IR, a crankshaft 240 is rotatably supported by left and right main bearings
241 with the crankshaft 240 horizontally extending beyond the left and right main
bearings 241. An AC generator 260 is provided on the right extending portion of the
crankshaft 240. A cam chain drive sprocket 255 and a belt drive pulley 276 of the
continuously variable belt-type transmission 235 are provided on the left extending
portion of the crankshaft 240.
[00135] In the internal combustion engine 230, a piston 242 which reciprocates in a
cylinder liner 244 of a cylinder block 232 and a crankpin 240a of the crankshaft 240
are linked by a connecting rod 243.
[00136] The present four-cycle internal combustion engine 230 employs a SOHC
valve system. A valve mechanism 250 is provided in a cylinder head cover 234. A cam
chain 251 for driving the valve mechanism 250 is wound between a cam shaft 254 and
the crankshaft 240. A cam chain chamber 252 is formed through the crankcase section
231a, cylinder block 232, and cylinder head 233.
[00137] More specifically, the cam chain 251 is wound, through the cam chain
chamber 252, between a driven sprocket 254 fitted to a left end portion of a cam shaft
253 which is horizontally oriented in the lateral direction and the drive sprocket 255
fitted to the crankshaft 240.
[00138] A spark plug 245 is fitted into the cylinder head 233 diagonally from the
opposite side to the cam chain chamber 252 (from the right side) toward a combustion
chamber.
[00139] The valve mechanism 250 is provided inside the cylinder head cover 234 as
shown in Fig. 15. With the cylinder largely inclined forwardly into a nearly horizontal

position, an intake valve 256 and an exhaust valve 257 are provided above and below the cam shaft 253, respectively. A rocker arm 259i and a rocker arm 259e are rockably fitted to an upper rocker shaft 258i and a lower rocker arm 258e, respectively. As the cam attached to the cam shaft 253 turns, the rocker arms 259i and 259e are rocked to open and close the intake valve 256 and the exhaust valve 257 at a predetermined timing.
[00140] The AC generator 260 is provided on the right side surface of the right unit case 23IR. A bowl-shaped outer rotor 262 is fixed, via an ACG boss 261, to an end portion of the crankshaft 240 projecting from a central cylindrical portion 23 Id of the right unit case 23IR. A magnet 263 is circumferentially disposed along the inner circumference of the outer rotor 262, Inside the magnet 263, a stator 264 aroimd which a stator coil 265 is wound is fixed to the central cylindrical portion 23 Id. [00141] A forced-cooling fan 266 is attached on the right side face of the outer rotor 262. The side of the fan 266 is covered by a fan cover 267. A shroud 268 surroundingly covering the cylinder block 232 and cylinder head 233 is provided continuously with the fan cover 267.
[00142] In the crankcase section 231a of the unit swing case 231, the cam chain chamber 252 is formed being separated from the crankcase by the main bearing 241. The left side wall of the cam chain chamber 252 forms a separation wall 271 which separates the continuously variable belt-type transmission chamber 270 to the left of the separation wall 271 from the cam chain chamber 252. A circular through hole 271a, through which the crankshaft 240 extends, is formed through the separation wall 271, the through hole 271a having a flat cylindrical shape with a large diameter. An annular sealing member 272 is press-fitted in the through hole 271a. The crankshaft 240 extends through the hollow portion of the annular sealing member 272. [00143J The drive sprocket 255 is fitted in a portion between the sealing member 272

and the main bearing 241 of the crankshaft 240. The cam chain 251 is wound on the
drive sprocket 255.
[00144] The sealing member 272 watertightly separates the continuously variable
belt-type transmission chamber 270 and the cam chain chamber 252, so that oil
leakage from the latter to the former is prevented.
[00145] A belt drive pulley 276 is rotatably provided on the crankshaft 240 extending
through the sealing member 272.
[00146] The belt drive pulley 276 includes a fixed pulley half 277 and a movable
pulley half 278. The fixed pulley half 277 is fixed, via a boss 279, to a left end portion
of the crankshaft 240. The movable pulley half 278 is spline-fitted, on the right of the
fixed pulley half 277, to the crankshaft 240. The movable pulley half 278 rotates
together with the crankshaft 240. While rotating, the movable pulley half 278 can
axially slide toward or away from the fixed pulley half 277. A V-belt 275 is rotatably
held between the fixed pulley half 277 and the movable pulley half 278.
[00147] A cam plate 280 is fixedly provided, closely to the annular sealing member
272, to the right of the movable pulley half 278. A slide piece 280a provided in an
outer peripheral end portion of the cam plate 280 is slidably engaged with a cam plate
sliding boss portion 278a axially formed in an outer peripheral end portion of the
movable pulley half 278.
[00148] The side surface on the cam plate 280 side of the movable pulley half 278 is
tapered toward the cam plate 280. A dry weight roller 281 is accommodated on the
inner side of the tapered surface, that is, between the tapered surface and the cam plate
280.
[00149] When the rotation speed of the crankshaft 240 increases, the dry weight roller
281 also rotating between the movable pulley half 278 and the cam plate 280 is
centrifugally moved in the centrifugal direction to push and move the movable pulley

half 278 leftward closer to the fixed pulley half 277. As a result, the V-belt 275 held between the pulley halves 277 and 278 is moved in the centrifugal direction to increase the winding diameter.
[00150] A belt-driven pulley 286 corresponding to the belt-drive pulley 276 is disposed rearward of the belt drive pulley 276 and includes a fixed pulley half 287 and a movable pulley half 288. The fixed pulley half 287 is fitted to an inner sleeve 289 which is supported to be rotatable relative to a speed reducer input shaft 292 of the speed reduction mechanism 238. The movable pulley half 288 is fitted to an outer sleeve 290 which is axially movably supported, to the left of the fixed pulley half 287, by the inner sleeve 289.
[00151] The V-belt 275 is held between the pulley halves 287 and 288. [00152] A centrifugal clutch 291 is provided on the left side of the speed reducer input shaft 292 and inner sleeve 289. When the rotation speed of the inner sleeve 289 increases, the centrifugal clutch 291 engages to transmit the power transmitted to the inner sleeve 289 via the V-belt 275 to the speed reducer input shaft 292. [00153] In the speed reduction mechanism 238, the power transmitted to the speed reducer input shaft 292 is transmitted to an output shaft 294 via an intermediate shaft 293, that is, the rotation of the input shaft 292 is transmitted to the output shaft 294 after deceleration by means of a gear engagement. The output shaft 294 makes up a rear wheel shaft to rotate the rear wheel 221.
[00154] Referring to Fig. 14, a transmission case cover 236 covering the continuously variable belt-type transmission chamber 270 from the left side covers a portion of the continuously variable belt-type transmission chamber 270 extending from the belt-drive pulley 276 on the front side to the centrifugal clutch 291 on the rear side. A kick shaft 227 is rotatably inserted through and supported at a portion slightly forward of a middle portion of the transmission case cover 236. A drive helical gear 2100 is fitted

to an inner end portion of the kick shaft 227. The drive helical gear 2100 is biased by
a return spring 2101.
[00155] A sliding shaft 2102 is supported at a front inner portion of the transmission
case cover 236 coaxially with the crankshaft 240, rotatably, and axially slidably. A
driven helical gear 2103 is formed on the sliding shaft 2102 and is engaged with the
drive helical gear 2100. A ratchet wheel 2104 is fixed to a right end portion of the
driven helical gear 2103. These parts as a whole are biased leftward by a friction
spring 2104.
[00156] On the boss 279 on the crankshaft 240 side, a ratchet 279a opposing the
ratchet wheel 2105 is formed. They can be brought into or out of contact with each
other by sliding the sliding shaft 2102.
[00157] When a kick pedal is pressed down and the kick shaft 227 rotates opposing
the return spring 2101, the drive helical gear 2100 rotates integrally with the kick
shaft 227. This causes the driven helical gear 2103 engaged with the drive helical gear
2100 to rotate integrally with the sliding shaft 2102 and slide rightward opposing the
friction spring 2105. As a result, the ratchet wheel 2104 engages the ratchet 279a
formed on the boss 279, and the crankshaft 240 is forcedly rotated to start the intemal
combustion engine 230.
[00158] In the present intemal combustion engine, a starter motor 2110 is disposed
above the crankcase section 231a of the left unit case 23IL. As shown in Fig. 16, the
starter motor 2110 includes a leftwardly projecting pinion 2113 around which an inner
rotor coil 2112 surrounded by an outer stator magnet 2111 is wound. A gear 2113a is
formed at an end portion of the pinion 2113.
[00159] A jump gear mechanism 2115 held between the crankcase section 231a and
the transmission case cover 236 is positioned between the starter motor 2110 and the
belt-drive pulley 276 with its shaft laterally horizontally oriented. The pinion gear

2113a of the starter motor 2110 is engaged with an input gear 2116 disposed to the
right of the jump gear mechanism 2115. A left jump gear 2117 is disposed to the left
of the jump gear mechanism 2115. When the left jump gear 2117 jumps out leftward,
it engages a starter ring gear 277a formed on an outer peripheral edge of the fixed
pulley half 277.
[00160] Therefore, when the starter motor 2110 is started, the rotation of the pinion
2113 is transmitted to the input gear 2116 of the jump gear mechanism 2115, causing
the jump gear 2117 to jump out leftward and engage the starter ring gear 277a of the
fixed pulley half 277. As a result, the fixed pulley half 277 rotates together with the
crankshaft 240 to start the internal combustion engine 230.
[00161] When the starter motor 2110 stops, the jump gear 2117 retracts to be
disengaged from the starter ring gear 277a.
[00162] The fixed pulley half 277 on which the starter ring gear 277a to be engaged
with the jump gear 2117 is formed has a cooling fan 2118 made of iron and bolted
(not shown) to its side (left side) opposite to the side where the V-belt 275 is held. The
cooling fan 2118 operates to take in the outside air for cooling the continuously
variable belt-type transmission 235.
[00163] The transmission case cover 236 includes a side wall and a peripheral wall,
the former covering a left side portion and the latter surrounding an outer peripheral
portion, respectively, of the continuously variable belt-type transmission 235. As
shown in Fig. 17, the side wall includes, in a front portion thereof, a concave wall
portion 236a which is continuous, via a step 236b, with the remaining portion of the
side wall. The concave wall portion 236a has a case air intake port 236c which, facing
leftward, has a deformed rectangular shape.
[00164] As shown in broken line in Fig. 17, a cylindrical case air exhaust duct 236d is
formed to extend, in an approximately central portion in the front-rear direction of the

side wall, in a diagonal upward-downward direction along the inner surface of the side
wall. The upper end of the exhaust duct 236d is opened to the chamber interior. The
lower end is opened to the outside.
[00165] Thus, the case air intake port 236c in a front portion of the transmission case
cover 236 is opened toward the cooling fan 2118 heat-bonded to the fixed pulley half
277 (see Fig. 14). The rotation of the cooling fan 2118 can take cooling air into the
continuously variable belt-type transmission chamber 270 through the case air intake
port 236c. The cooling air having cooled the continuously variable belt-type
transmission 235 can be exhausted to the outside through the case air exhaust duct
236d
[00166] A support 236e to support the jump gear 2117 is formed in an upper portion
of the concave wall portion 236a provided in a front portion of the transmission case
cover 236, the support 236e having a partially circular conic shape. Bolt holes 236i
and 236j are formed above and below the case air intake port 236c, respectively.
[00167] An air intake duct 2150 serving also as a heel guide member is fitted to the
concave wall portion 236a provided in a front portion of the transmission case cover
236.
[00168] An inner wall member 2151 and an outer wall cover member 2161 of the air
intake duct 2150 are united to form an air intake duct which internally provides air
passage space.
[00169] As shown in Figs. 18 to 20, the inner wall member 2151 includes an inner
wall 2152 which is shaped like a pectoral fin of a fish as seen in a side view (see Figs.
18 and 19). The inner wall 2152 includes an upper wall portion 2152u, a lower wall
portion 21521, and a slanted wall portion 2152s, the three wall portions being vertical
as seen in a front view and shaping the inner wall 2152 such that the upper wall
portion 2152u and the lower wall portion 21521 being laterally shifted from each other

are linked by the slanted wall portion 2152s (see Fig. 20).
[00170] A peripheral wall 2153 projects on the left side surface of the inner wall 2152
to be shghtly inside the peripheral edge of the inner wall 2152 (see Fig. 18).
[00171] The upper wall portion 2152u of the inner wall 2152 includes an air intake
port 2154 formed inside the peripheral wall 2153. A louver 2155 is installed over the
air intake port 2154.
[00172] In the lower wall portion 21521 of the inner wall 2152, a connection port
2152c corresponding to the case air intake port 236c formed in the concave wall
portion 236a is formed.
[00173] In the slanted wall portion 2152s, a circular conic portion 2152e
corresponding to the circular conic support 236e formed on the transmission case
cover 236 is formed.
[00174] On the left side surface of the inner wall 2152, a projecting strip is projects to
extend to be curved forwardly and downwardly from above the cormection port 2152c
along a f|-ont side of the connection port 2152c. A front lower portion of the projecting
strip 2156 extends downwardly in parallel with a front side portion of the peripheral
wall 2153, forming a drain passage 2170 between them.
[00175] The drain passage 2170 has an open lower end.
[00176] A linear projecting strip 2157 projects upwardly of the projecting strip 2156
and downward of the air intake port 2154.
[00177] The projecting strip 2157 extends, below the air intake port 2154, forwardly
and slightly downwardly from a rear edge portion of the peripheral wall 2153. A rear
portion of the lower projecting strip 2156 is positioned below a front portion of the
upper projecting strip 2157, forming an air passage 2160 between them.
[00178] A cutout 2153b is formed at a location downward of a rear end portion of the
projecting strip 2156 with the location being in a slanted rear edge portion of the

peripheral wall 2153. A fixing hole 2158i is formed in an upper end portion of the
portion below the cutout 2153b of the peripheral wall 2153. A projecting strip 2153a
extends forwardly and upwardly from the fixing hole 2158i,
[00179] The fixing hole 2158i is located above the connection port 2152c and
corresponds to the bolt hole 236i formed in the transmission case cover 236. A fixing
hole 2158J corresponding to the bolt hole 236j is formed below the connection port
2152c.
[00180] A catching projection 2159p projects on a rear edge portion, which is more
rearwardly positioned than the air intake port 2154, of the upper wall portion 2152u of
the inner wall 2152. Another catching projection 2159q projects on a curved lower
front edge portion of the lower wall portion 21521.
[00181] As shown in Figs. 21 to 23, the outer wall cover member 2161 includes an
outer wall 2162 which is shaped approximately the same as the inner wall 2152 of the
inner wall member 2151 as seen in a side view (see Figs. 21 and 22). The outer wall
2162 includes an upper wall portion 2162u, a lower wall portion 21621, and a slanted
wall portion 2162s, the three wall portions being vertical as seen in a front view and
shaping the outer wall 2162 such that the upper wall portion 2162u and the lower wall
portion 21621 being laterally shifted from each other are linked by the slanted wall
portion 2162s (see Fig. 23).
[00182] A peripheral wall 2163 slightly larger than the peripheral wall 2153 of the
inner wall member 2151 projects on the right side surface of and along the peripheral
edge of the outer wall 162 (see Fig. 22).
[00183] A projecting strip 2166 projects on the right side surface of the outer wall
2162, the projecting strip 2166 being shaped to fit the upper side of the projecting
strip 2156 curvedly formed on the left side surface of the inner wall 2152. Thus, the
drain passage 2170 is also formed between the projecting strip 2166 and the

peripheral wall 2163.
[00184] A projecting strip 2167 projects upwardly of the projecting strip 2166, the
projecting strip 2167 being shaped to fit the upper side of the linear projecting strip
2157 formed on the left side surface of the inner wall 2152.
[00185] Fixing holes 2168i and 2168j corresponding to the fixing holes 2158i and
2158J are formed in a middle portion and a lower end portion of the rear slanted
portion of the peripheral wall 2163.
[00186] Catching pieces 2169p and 2169q corresponding to the catching projections
2159p and 2159q are formed in an upper rear edge portion and a lower front edge
portion, respectively, of the peripheral wall 2163.
[00187] The catching piece 2169p is shaped like a hook to catch and engage the
catching projection 2159p. The catching piece 2169q has a hole into which the
catching projection 2159 is inserted for engagement.
[00188] The inner wall member 2151 and the outer wall cover member 2161 are
joined together by aligning the inner wall 2152 and the outer wall 2162 such that they
face each other and fitting the peripheral wall 2163 of the outer wall cover member
2161 around the outer periphery of the peripheral wall 2153 of the inner wall member
2151. In doing this, first, the catching projection 2159q of the inner wall member
2151 is inserted into the catching piece 2169q of the outer wall cover member 2161
thereby engaging the two parts, and then the inner wall member 2151 and the outer
wall cover member 2161 are joined together by fitting the peripheral wall 2153 and
the peripheral wall 2163 to each other. When this is done, the catching projection
2159p of the inner wall member 2151 is caught by the catching piece 2169p of the
outer wall cover member 2161. As a result, the inner wall member 2151 and the outer
wall cover member 2161 are united into an air intake duct 2150.
[00189] Inside the air intake duct 2150, an air passage 2160 is formed by the linear

upper projecting strips 2157 and 2167 and the curved lower projecting strips 2156 and 2166. The air passage 2160 has a labyrinth structure and leads from the air intake port 2154 formed in an upper portion of the inner wall 2152 to the connection port 2152c formed in a lower portion of the inner wall 2152.
[00190] If mud or water enters the air passage 2160 through the air intake port 2154, the mud or water flows forward over the upper surfaces of the inclined upper projecting strips 2157 and 2167, drops from the front ends of the inclined upper projecting strips 2157 and 2167 onto the lower projecting strips 2156 and 2166. The mud or water then further flows forward over the curved projecting strips 2156 and 2166, that is, down through the drain passage 2170 to be subsequently discharged to the outside.
[00191] The air intake duct 2150 is fitted to the concave wall portion 236a formed in a front portion of the transmission case cover 236.
[00192] In doing this, the lower wall portions 21521 and 21621 and slanted wall portions 2152s and 2162s of the air intake duct 2150 are fitted to the concave wall portion 236a, and the mutually fitted fixing holes 2158i and 2168i and the mutually fitted fixing holes 2158j and 2168j are fitted to the corresponding bolt holes 236i and 236j, respectively, formed in the transmission case cover 236. Bolts 2171 and 2172 are then inserted through the corresponding fixing holes and bolt holes thus fitted together and tightened to fix the air intake duct 2150 to the transmission case cover 236,
[00193] When the air intake duct 2150 has been fixed to the transmission case cover 236, the outer surface of the outer wall cover member 2161 of the air intake duct 2150 is coplanar with the outer surface of the transmission case cover 36. The connection port 2152c formed in a lower portion of the inner wall member 2151 is connected to the case air intake port 236c formed in the transmission case cover 236.

[00194] The upper wall portions 2152u and 2162u of the air intake duct 2150 project upwardly above the transmission case cover 236 while curving toward the vehicle inside. The air intake portion 2154 formed in the upper wall portion 2152u of the inner wall member 2151 is open to the right (toward the vehicle inside). [00195] The louver 2155 provided at the air intake port 2154 faces the right (the vehicle inside) with its blades inclined to the right (toward the vehicle inside) and downwardly not to easily allow mud or water to enter the air intake port 2154 from above.
[00196] As described above, the air intake duct 2150 to serve also as a heel guide member is attached to a front portion of the transmission case cover 236. Therefore, when the cooling fan 2118 attached to the fixed pulley half 277 of the continuously variable belt-type transmission 235 rotates, the outside air is introduced, as a cooling air, from the air intake port 2154 of the air intake duct 2150 into the continuously variable belt-type transmission chamber 270 via the air passage 2160. Thus, the case air intake port 236c, and the cooling air having cooled the continuously variable belt-type transmission 235 is exhausted from the case air exhaust duct 236d to the outside. [00197] If foreign matter such as mud or water enters the air passage 2160 through the air intake port 2154, the foreign matter is discharged to the outside through the drain passage 2170 formed by the projecting strips 2157 and 2167 and the projecting strips 2156 and 2166, so that foreign matter is prevented from entering the continuously variable belt-type transmission 270.
[00198] The air intake duct 2150 serves as a heel guide member. The upper wall portions 2152u and 2162u projecting above the transmission case cover 236 make up a guide portion 2150u. As shown in Fig. 10, the guide portion 2150u is partly overlapped, as seen in a side view, by a rear end portion of the pillion step portion 215r of the step plate 215 and extends upwardly covering the concave 219 formed

above the overlapped portion.
[001991 In the air cleaner 225 disposed upward of the crankcase section of the internal
combustion engine 230, a rear portion of a container 225a is laterally bulging to both
sides, and an intake duct 225b extends forward from the left bulging portion along the
left wall of the container 225a.
[00200] A cleaner air intake port 225i which is opened at a front end of the intake duct
225b is inwardly separated from the guide portion 2150u of the air intake duct 2150
(see Figs. 12 and 13) and overlaps with the guide portion 2150u as seen in a side view
(see Fig. 11).
[00201] Thus, with the guide portion 2150u of the air intake duct 2150 covering, from
outside, the cleaner air intake port 225i of the air cleaner 225, foreign matter, for
example, mud or water is prevented from entering the air cleaner 225.
[00202] The heel portion Fh of the passenger's foot F (shown in two-dot chain line in
Fig. 10) placed on the pillion step portion 215r is guided in place by the guide portion
2150u closing the concave 219 from an inner side of the vehicle.
[00203] The air intake duct 2150 serving also as a heel guide member enables a cost
reduction by decreasing the numbers of components and assembly man-hours required.
[00204] The shroud 268 covering the periphery of the cylinder block 232 and cylinder
head 233 of the intemal combustion engine 230 has a rectangular opening in its front
end portion and, as shown in Figs. 11 to 14, the cylinder head cover 234 is fitted
through and projecting forward from the rectangular opening. An upper wall 268u, a
lower wall 268d, and a left wall 2681 extend rearwardly from the rectangular opening
along the sides of the cylinder head 233 and cylinder block 232. The right wall 268r
largely bulges rightward to be increasingly separated from the cylinder head 233 and
cylinder block 232 until being connected to the fan cover 267.
[00205] The fan cover 267 includes an annular frame 267a whose central axis is the

crankshaft 240. A front peripheral portion of the annular frame 267a is screwed, with a screw 2120, to a rear end portion of the right wall 268r of the shroud 268. The portion other than the front peripheral portion of the annular frame 267a is fixedly bolted, with a bolt 2121, to a right edge portion of the right unit case 23IR. The fan cover 267 is regarded as an extension member of the shroud 268, and a cooling air intake port 267i is provided, facing the forced-cooling fan 266, in the right wall (see Fig. 14). [00206] A cooling air outlet port 268e is opened in a rear lower-half portion of the left wall 2681 of the shroud 268 with a front end portion of the air exhaust duct 269 connected to the cooling air outlet port 268e.
[00207] The air exhaust duct 269 extends to the left from the cooling air outlet port 268e provided in the left wall 2681 and then is curved and further extends rearwardly and downwardly. The air exhaust duct 269 is partly fitted to the concave wall portion 236a of the transmission case cover 236, along the lower end surface of the air intake duct 2150 until reaching the step 236b of the transmission case cover 236 where a rear-end air exhaust port 269e is opened rearwardly and downwardly (see Figs. 11-13). [00208] The shroud 268 surroundingly covering the cylinder block 232 and cylinder head 233 includes the cooling air intake port 267i provided in the fan cover 267 that is a rearward extension of the right wall 268r and the cooling air outlet port 268e formed in the left wall 2681 opposing the right wall 268r. Therefore, as seen in Fig. 14, the cooling air sucked in from the cooling air intake port 267i by the rotation of the forced-cooling fan 266 flows, while being diagonally forwardly guided by the curved right wall 268r, leftward passing around the peripheral portions of the cylinder block 232 and cylinder head 233, thereby cooling the cylinder block 232 and cylinder head 233. The cooling air having cooled the cylinder block 232 and cylinder head 233 flows out of the cooling air outlet port 268e provided in the left wall 2681 without changing the flow direction.

[00209] Thus, the cooling air flows evenly and smoothly, without becoming locally
stagnant, through the inside of the shroud 268 unidirectionally from the cooling air
intake port 267i to the cooling air outlet port 268e before being let out from the air
exhaust duct 269. The cooling air can, therefore, cool the portions to be cooled of the
cylinder block 232 and cylinder head 233 of the internal combustion engine 230
thoroughly and efficiently. Furthermore, with the passage resistance being small and
the cooling air volume being large, a great cooling effect can be expected.
[00210] Referring to the side view shown in Fig. 11 of the power unit 210, the air
exhaust duct 269 is located below the cylinder axis C - C that is the central axis of the
cylinder bore of the cylinder block 232.
[00211] Referring to the front view shown in Fig. 13 of the power unit 210, the air
exhaust duct 269 is located, in the motorcycle width direction, approximately outside
(to the right of, as seen in Fig. 13) the air cleaner 225 and inside (to the left of, as seen
in Fig. 13) the outer surface of the transmission case cover 236.
[00212] Thus, the air exhaust duct 269 is small and can be compactly installed on the
left of the shroud 268 to extend along the lower end surface of the air intake duct 2150.
This makes the air exhaust duct 269 less conspicuous resulting in better appearance.
[00213] The cleaner air intake port 225i of the air cleaner 225 and the air intake port
2154 of the air intake duct 2150 are both located higher than the cylinder axis C - C as
seen in a side view (see Fig. 11).
[00214] Namely, whereas the air exhaust port 269e of the air exhaust duct 269 is
located below the cylinder axis C - C, the cleaner air intake port 225i and the air
intake port 2154 are located higher than the cylinder axis C - C. Moreover, the air
intake duct 2150 and the transmission case cover 236 exist between them.
[00215] Therefore, the warm exhaust air coming out of the air exhaust port 269e
below the air intake duct 2150 mostly flows rearward along the lower surface of the

transmission case cover 236. If part of the exhaust air flows upward along the side surface of the transmission case cover 236, it is unlikely to be sucked into the cleaner air intake port 225i or the air intake port 2154. This can prevent the intake air temperature from rising and the cooling efficiency for the continuously variable belt-type transmission 35 from lowering.
[00216] The air intake port 2154 is located, in the motorcycle width direction, between the cleaner air intake port 225i and the air exhaust port 269e of the air exhaust duct 269 (see Fig. 13).
[00217] Therefore, if the engine cooling air exhausted from the air exhaust port 269e flows upward, for example, when the motorcycle is stopped, the exhaust air is likely to be led to the nearer air intake port 2154 before reaching the farther cleaner air intake port 225i, so that the exhaust air is quite unlikely to be sucked into the farther cleaner air intake port 225i. This can prevent the intake air temperature from rising. [00218] Furthermore, the air intake duct 2150 and the cleaner air intake port 225i are located to overlap with each other as seen in a side view, so that the guide portion 2150u serves as an external guide to securely prevent the engine cooling air exhausted from the air exhaust port 269e from being sucked into the cleaner air intake port 225i. This makes it more possible to prevent the intake air temperature from rising and foreign matter, for example, mud or water from entering through the cleaner air intake port.
[00219] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.












WHAT IS CLAIMED IS:
1. An internal combustion engine with forced air cooling in which a cylinder
block (36) which is joined with a crankcase (35) rotatably receiving a crankshaft (45)
and from which cooling fins (36a) project and a cylinder head (37) which is joined
with the cylinder block (36) and to which an ignition plug (51) is attached are
surrounded by a shroud (70) forming a cooling air path (71) between the shroud (70)
and the cylinder block (36) and cylinder head (37), a cooling fan (68) for ventilating
cooling air aspirated from outside the shroud (70) toward the cooling air path (71) is
associated with and coupled to the crankshaft (45), and an air outlet (116) for
discharging the cooling air having flowed through the cooling air path (71) to an
outside is formed to the shroud, comprising:
a notched space (78) formed to a part of a periphery of the cylinder block (36) by partially shortening or removing the cooling fins (36a) projecting from the periphery of the cylinder block (36); and
a first projection (72a) projecting inwardly along the notched space (78) and a second projection (73a) projecting inwardly at a position where the ignition plug (51) attached to one side of the cylinder head (37) is between the second projection (73a) and the first projection (72a) are formed to the shroud (70).
2. The internal combustion engine with forced air cooling according to
claim 1, wherein the air outlet (116) is provided to the shroud (70) to be adjacent to an
exhaust pipe (61) which communicates with an exhaust port (48) provided to the
cylinder head (37) and which is connected to the cylinder head (37).

3. The internal combustion engine with forced air cooling according to claim 1, wherein the notched space (78) is formed to a periphery of the cyHnder head (36) on a side corresponding to an inlet port (47) provided to the cylinder head (36).
4. The internal combustion engine with forced air cooling according to claim 2, wherein the notched space (78) is formed to a periphery of the cylinder head (36) on a side corresponding to an inlet port (47) provided to the cylinder head (36).
5. The internal combustion engine with forced air cooling according to claim
1, wherein the air outlet (116) and the second projection (73a) are formed to one of a
pair of sides of the shroud (70), the pair of sides being disposed to opposing sides of a
plane including an axis of the ignition plug (51), such that a portion corresponding to
the ignition plug (51) is between the air outlet (116) and second projection (73a).
6. The internal combustion engine with forced air cooling according to claim
2, wherein the air outlet (116) and the second projection (73a) are formed to one of a
pair of sides of the shroud (70), the pair of sides being disposed to opposing sides of a
plane including an axis of the ignition plug (51), such that a portion corresponding to
the ignition plug (51) is between the air outlet (116) and second projection (73a).
7. The intemal combustion engine with forced air cooling according to claim
3, wherein the air outlet (116) and the second projection (73a) are formed to one of a
pair of sides of the shroud (70), the pair of sides being disposed to opposing sides of a
plane including an axis of the ignition plug (51), such that a portion corresponding to
the ignition plug (51) is between the air outlet (116) and second projection (73a).

8. The internal combustion engine with forced air cooling according to claim
1, wherein the first projection (72a) and the second projection (73a) are offset from
each other in a direction along the plane including the axis of the ignition plug (51)
when viewed from a direction along a cylinder axis.
9. The internal combustion engine with forced air cooling according to claim
2, wherein the first projection (72a) and the second projection (73a) are offset from
each other in a direction along the plane including the axis of the ignition plug (51)
when viewed from a direction along a cylinder axis.
10. The internal combustion engine with forced air cooling according to claim
3, wherein the first projection (72a) and the second projection (73a) are offset from
each other in a direction along the plane including the axis of the ignition plug (51)
when viewed from a direction along a cylinder axis.
11. The internal combustion engine with forced air cooling according to claim
5, wherein the first projection (72a) and the second projection (73a) are offset from
each other in a direction along the plane including the axis of the ignition plug (51)
when viewed from a direction along a cylinder axis.
12. The internal combustion engine with forced air cooling according to
claim 1, wherein the ignition plug (51) is attached to the cylinder head (37) while
being tilted toward the cooling fan (68).

13. The internal combustion engine with forced air cooling according to claim 2, wherein the ignition plug (51) is attached to the cylinder head (37) while being tilted toward the cooling fan (68).
14. The internal combustion engine with forced air cooling according to claim 3, wherein the ignition plug (51) is attached to the cylinder head (37) while being tilted toward the cooling fan (68).
15. The internal combustion engine with forced air cooling according to claim 4, wherein the ignition plug (51) is attached to the cylinder head (37) while being tilted toward the cooling fan (68).
16. The intemal combustion engine with forced air cooling according to claim 5, wherein the ignition plug (51) is attached to the cylinder head (37) while being tilted toward the cooling fan (68).
17. An intemal combustion engine with forced air cooling, comprising:
a power unit having an intemal combustion engine with a forwardly tilted cylinder, a power transmission mechanism rearwardly extending from the intemal combustion engine, and a rear wheel joumaled to a rear portion of the power transmission mechanism which are unitedly and swingably supported by a vehicle body frame, comprising:
a shroud surrounding the cylinder and a cylinder head of the intemal combustion engine,
a cooling fan which is driven by rotation of a crankshaft and which sucks in outside air from a neighborhood of the crankshaft into the shroud to cool the cylinder

and the cylinder head, and
an air cleaner provided above a crankcase of the internal combustion engine;
wherein the air cleaner has a cleaner air intake port provided above an axis of the cylinder;
the shroud has a cooling air intake port formed on a side of the crankcase;
a cooling air outlet port is formed in a side wall opposing another side wall where the cooling air intake port is formed; and
an air exhaust duct extending from the cooling air outlet port is located below the cylinder axis as seen in a side view while being located, as seen in a vehicle width direction, approximately outside the air cleaner and inside an outer surface of a transmission case cover covering the power, transmission mechanism.
18- The internal combustion engine with forced air cooling according to claim 17, wherein an air intake duct for taking outside air into the transmission case cover is provided, the air intake duct having an air intake port provided above the cylinder axis.
19. The internal combustion engine with forced air cooling according to claim 18, wherein the air intake port of the air intake duct is provided between the cleaner air intake port and the air exhaust port as seen in the vehicle width direction.
20. The intemal combustion engine with forced air cooling according to claim 18, wherein the air intake duct and the cleaner air intake port are disposed to overlap with each other as seen in a side view.

21. The internal combustion engine with forced air cooling according to
claim 19, wherein the air intake duct and the cleaner air intake port are disposed to
overlap with each other as seen in a side view.
22. The internal combustion engine with forced air cooling according to
claim 18, wherein the air exhaust duct extends, rearwardly along a lower end surface
of the air intake duct, to outside a vehicle body cover, the air exhaust duct having a
rear-end air exhaust port which is opened rearwardly.
23. The internal combustion engine with forced air cooling according to
claim 19, wherein the air exhaust duct extends, rearwardly along a lower end surface
of the air intake duct, to outside a vehicle body cover, the air exhaust duct having a
rear-end air exhaust port which is opened rearwardly.
24. The internal combustion engine with forced air cooling according to
claim 20, wherein the air exhaust duct extends, rearwardly along a lower end surface
of the air intake duct, to outside a vehicle body cover, the air exhaust duct having a
rear-end air exhaust port which is opened rearwardly.


Documents:

2965-CHE-2007 AMENDED CLAIMS 28-12-2011.pdf

2965-CHE-2007 EXAMINATION REPORT REPLY RECEIVED 28-12-2011.pdf

2965-CHE-2007 FORM-3 28-12-2011.pdf

2965-CHE-2007 CORRESPONDENCE PO.pdf

2965-CHE-2007 OTHER PATENT DOCUMENT 28-12-2011.pdf

2965-che-2007-abstract.pdf

2965-che-2007-claims.pdf

2965-che-2007-correspondnece-others.pdf

2965-che-2007-description(complete).pdf

2965-che-2007-drawings.pdf

2965-che-2007-form 1.pdf

2965-che-2007-form 18.pdf

2965-che-2007-form 26.pdf

2965-che-2007-form 3.pdf

2965-che-2007-form 5.pdf

2965-che-2007-other document.pdf


Patent Number 250897
Indian Patent Application Number 2965/CHE/2007
PG Journal Number 06/2012
Publication Date 10-Feb-2012
Grant Date 06-Feb-2012
Date of Filing 11-Dec-2007
Name of Patentee HONDA MOTOR CO., LTD.
Applicant Address 1-1, MINAMI-AOYAMA 2-CHOME MINATO-KU, TOKYO 107-8556
Inventors:
# Inventor's Name Inventor's Address
1 TSUCHIYA, RYUJI C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
2 TSUTSUMI, HIDEKATSU C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
3 TAKAMURO, MASATO C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
4 NUMAZAKI, YOSHIMI C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
PCT International Classification Number F01P5/06
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2007-032762 2007-02-13 Japan
2 2007-025814 2007-02-05 Japan