Title of Invention

A SWING-TYPE POWER UNIT

Abstract A swing-type power unit swingably supported by a body frame (F) of a motorcycle or a motor-tricycle comprising: an engine (E) including an engine block (32, 33); and a transmission (T) for transmitting a drive force of said engine (E) to a drive wheel (Wr), said transmission (T) being integrally connected to said engine (E); wherein said engine block (32, 33) is divided into a first engine block (32) having a cylinder block (321) extending forwardly of a vehicular body and being connected to a cylinder head (34) and a half (322) of a crank case, and a second engine block (33) having the other half of said crank case; and a hanger bracket (98R) for pivotably supporting said engine (E) on said body frame (F) via a pivot (15) is integrally formed on said half (322) of said crank case of said first engine block (32), a hanger bracket (98R) is disposed to circumference of a cylinder block (321).
Full Text FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
COMPLETE SPECIFICATION
[See Section 10]
"A" SWING-TYPE POWER UNIT"
HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan,
The following specification particularly describes the nature of the invention and the manner in which it is to be performed:-



GRANTED
28-9-2004


Technical Field to which the Invention Pertains
The present invention relates to a swing-type power unit. The present invention particularly relates to a swing-type power unit, which integrally includes an engine and a transmission for driving a drive force of the engine to a drive wheel and is swingably supported by a body frame.
Related Art
Such a swing-type power unit is suitably used as a simple drive source of a small-sized motorcycle or a motor-tricycle, and has been disclosed, for example, in Japanese Patent No. 2649179. In the related art swing-type power unit, the axial line of a cylinder block of an engine disposed at a front portion of the power unit, and a hanger bracket provided on the upper surface of a high rigid crank case of the engine is vertically swingably supported on a body frame via a pivot.
The co-pending Indian patent application No. 19/MUM/2000 provides a swing type power unit comprising an engine block for supporting a crank shaft of the engine, separable from a casing of the transmission, the engine block is divided into two parts along a parting plane extending in the vertical direction along a crank shaft.
The co-pending Indian patent application No. 28/MUM/2000 provides a swing type power unit comprising accessories for cooling the engine concentratedly disposed on the engine side.
Problem to be Solved by the Invention

In the case of the swing-type power unit in which the axial line of the cylinder block extends forwardly of the vehicular body, if the position of the pivot is largely separated rearwardly from the cylinder head, the cylinder head is largely moved in the vertical direction by the swing motion of the swing-type power unit. This causes a problem in which it becomes easy for the cylinder head to interfere with another member such as a step floor. To avoid such a problem, it may be considered to move the position of the pivot forwardly as much as possible to be made close to the cylinder head; however, if the crank case and the cylinder block are formed of separate members as shown in Japanese Patent No. 2649179, it is difficult to move the position of the pivot forwardly as much as possible.
Specifically, to prevent strain from being exerted on the cylinder block for containing a piston and a cylinder, the hanger bracket to which a large load is applied is required to be provided on the high rigid crank case. From this viewpoint, if the crank case and the cylinder block are formed of separate members, the hanger bracket cannot extend on the cylinder block side over a parting plane between the crank case and the

cylinder block because the parting plane must be finished by machining. Accordingly, the front end of the hanger bracket provided on the crank case must be stayed at a position behind the parting plane to which the cylinder block is connected, thereby causing a problem that the position of the pivot is inevitably offset to the rear side of the vehicular body.
In view of the foregoing, the present invention has been made, and an object of the present invention is to dispose a hanger bracket for pivotably supporting a swing-type power unit on a body frame in such a manner as to offset the position of the hanger bracket to the front side of a vehicular body as much as possible, thereby preventing a cylinder head from interfering with another member such as a step floor.
[Means for Solving the Problem]
To achieve the above object, according to an
invention there is provided a |

swing-type power unit swingably supported by a body frame of a motorcycle or a motor-tricycle, including: an engine including an engine block; and a transmission for transmitting a drive force of the engine to a drive wheel,


the transmission being integrally connected to the engine; wherein the engine block is divided into a first engine block including a cylinder block extending forwardly of a vehicular body and being connected to a cylinder head and a half of a crank case, and a second engine block including the other half of the crank case; and a hanger bracket for pivotably supporting the engine on the body frame via a pivot is integrally formed on the half of the crank case of the first engine block.
With this configuration, since the engine block is divided into the first and second engine blocks, and the hanger bracket for pivotably supporting the engine on the body frame via the pivot is integrally formed on the half of the crank case of the first engine block composed of the cylinder block and the half of the crank case, it is possible to make the position of the pivot sufficiently close to the cylinder head without obstructing the machining. As a result, the movement range of the cylinder head in the vertical direction by the swing motion of the engine around the pivot is reduced, so that it is possible to avoid the interference of the cylinder head with another member such as a step floor.

According to an invention addition to the configuration of the invention a carburetor is disposed directly after the pivot, and the carburetor and the cylinder head are connected to each other via an intake pipe.
With this configuration, since the carburetor is disposed directly after the pivot provided sufficiently close to the cylinder head, it is possible to shorten the length of the intake pipe for connecting the carburetor to the cylinder head, and hence to enhance the output of the engine.
[Brief Description of the Drawings]
[Fig. 1]
A side view showing an entire configuration of a
scooter-type motorcycle. [Fig. 2]
An enlarged view of an essential portion shown in
Fig. 1.


[Fig. 3]
A sectional view taken on line 3-3 of Fig. 2. [Fig. 4]
A view seen along line 4-4 of Fig. 3. [Fig. 5]
A sectional view taken on line 5-5 of Fig. 3. [Fig. 6]
A sectional view taken on line 6-6 of Fig. 3. [Fig. 7]
A sectional view taken on line 7-7 of Fig. 3. [Fig. 8]
An enlarged view of an essential portion of Fig. 2. [Fig. 9]
A sectional view taken on line 9-9 of Fig. 8. [Fig. 10]
A left side view of a power unit. [Fig. 11]
A view illustrating the function of the present invention upon assembly of the power unit.


[Mode for carrying Out the Invention]
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
Figs. 1 to 11 show one embodiment of the present invention, wherein Fig. 1 is a side view showing an entire configuration of a scooter-type motorcycle; Fig. 2 is an enlarged view of an essential portion shown in Fig. 1; Fig. 3 is a sectional view taken on line 3-3 of Fig. 2; Fig. 4 is a view seen along line 4-4 of Fig. 3; Fig. 5

is a sectional view taken on line 5-5 of Fig. 3; Fig. 6 is a sectional view taken on line 6-6 of Fig. 3; Fig. 7 is a sectional view taken on line 7-7 of Fig. 3; Fig. 8 is an enlarged view of an essential portion of Fig. 2; Fig. 9 is a sectional view taken on line 9-9 of Fig. 8; Fig. 10 is a left side view of a power unit; and Fig. 11 is a view illustrating the function of the first embodiment upon assembly of the power unit.
Referring to Figs. 1 and 2, a scooter-type motorcycle V includes a front wheel Wf steered by a steering handle 11 and a rear wheel Wr driven by a swing-type power unit P. A body frame F of the motorcycle V is divided into three parts, that is, a front frame 12, a center frame 13, and a rear frame 14. The front frame 12 is made from an aluminum alloy by casting, and integrally includes a head pipe 121 a down tube 122, and a step floor supporting portion 123. The center frame 13 by means of which the power unit P is vertically swingably supported via a pivot 15 is made from an aluminum alloy by casting and is connected to the rear end of the front frame 12. The rear frame 14 extending rearwardly, upwardly from the power unit P is formed of an annular pipe. A fuel tank 16 is supported on the upper surface of


the rear frame 14. A helmet case 17 is supported on the upper surface of the center frame 13. The helmet case 17 and the fuel tank I6 are openably/closably covered with a cover 19 integrated with a seat 18.
The power unit P includes a water-cooled type single-cylinder/four-cycle engine E with its cylinder directed forwardly of the vehicular body, and a belt-type continuously variable transmission T which is integrally connected to the left side surface of the engine E and extends rearwardly of the vehicular body therefrom. The upper rear surface of the belt-type continuously variable transmission T is connected to the rear end of the center frame 13 via a rear cushion 20. An air cleaner 21 and a carburetor 24 are supported on the upper surface of the belt-type continuously variable transmission T. A muffler 22 is supported on the right side surface of the belt-type continuously variable transmission T, and a main stand 23 capable of being raised up and brought down is supported on the back surface of the engine E. A kick shaft 26 of a kick-tyPe starter 25 projects from the left side surface of the belt-type continuously variable
transmission T and a crank type kick pedal 27 is
provided at the leading end of the kick shaft 26.

As is apparent from Figs. 3 to 5, the engine E is divided along a parting plane P1 extending in the vertical direction along a crank shaft 31 into a first engine block 32 and a second engine block 33. The first engine block 32 constitutes a cylinder block 321 and a half 322 of a crank case, and the second engine block 33 constitutes the other half of the crank case. A cylinder head 34 is connected to the front end of the first engine block 32 via a parting plane P2, and a head cover 35 is connected to the front end of the cylinder head 34 via a parting plane P3. A generator cover 36 is connected to the right side surfaces of the first and second engine blocks 32 and 33 via a parting plane P4.
The belt-type continuously variable transmission T includes a right side first transmission casing 37 and a left side second transmission casing 38 which are connected to each other via a parting plane P5. The right side surface of a front portion of the first transmission casing 37 is connected to the left side surfaces of the first and second engine blocks 32 and 33 via a parting plane P6. The right side surface of a rear portion of the first transmission casing 37 is connected to a reducer

casing 39 via a parting plane P7.
As shown in Fig. 3, a piston 42 slidably fitted in a cylinder 41 provided in the first engine block 32 is connected to a crank shaft 31 via a connecting rod 43. A cam shaft 44 is rotatably supported by the cylinder head 34, and intake valves and exhaust valves (not shown) provided in the cylinder head 34 are opened/closed by the cam shaft 44. A timing chain 45 contained in a chain passage 323 provided in the first engine block 32 is wound around a drive sprocket 46 provided on the crank shaft 31 and a driven sprocket 47 provided on the cam shaft 44. The cam shaft 44 makes one revolution for two revolutions of the crank shaft 31.
An ac generator 48 provided on the right side of the crank shaft 31 is covered with the generator cover 36, and a radiator 49 is provided on the right side of the generator cover 36. A cooling fan 50 fixed at the right end of the crank shaft 31 for supplying cooling wind to the radiator 49 is disposed between the ac generator 48 and the radiator 49. A thermostat case 52 containing a thermostat 51 is connected to the right side surface of the cylinder head 34 via a parting plane P6. A cooling

water pump 53 provided at the right end of the cam shaft 44 is contained in a space surrounded by the cylinder head 34 and the thermostat case 52.
A drive pulley 54 as an input rotational member of the belt-type continuously variable transmission T is provided at the left end of the crank shaft 31 projecting in the first and second transmission casings 37 and 38. The drive pulley 54 includes a fixed side pulley half 55 fixed on the crank shaft 31, and a movable side pulley half 56 movable close to or apart from the fixed side pulley half 55. The movable side pulley half 56 is biased toward the fixed side pulley half 55 by a centrifugal weight 57 moved radially outwardly in accordance with the increased rotational number of the crank shaft 31. ]
A driven pulley 59 is provided on an output shaft 58 supported between a rear portion of the first transmission casing 37 and the reducer casing 39. The driven pulley 59 includes a fixed side pulley half 60 relatively rotatably supported by the output shaft 58, and a movable side pulley half 61 movable close to or apart from the fixed side pulley half 60. The movable pulley half 61 is biased toward the fixed side pulley

half 60 by a spring 62. A starting clutch 63 is provided between the fixed pulley half 60 and the output shaft 58. An endless V-belt 64 is wound between the drive pulley 54 and the driven pulley 59.
An intermediate shaft 65 and an axle 66 in parallel to the output shaft 58 are supported between the first transmission casing 37 and the reducer casing 39. A reduction gear train 67 is provided among the output shaft 58, the intermediate shaft 65, and the axle 66. The rear wheel Wr is provided at the right end of the axle 66 projecting rightwardly through the reducer casing 39.

The rotation of the crank shaft 31 of the engine E is transmitted to the drive pulley 54 as the input member of the belt-type continuously variable transmission T, and is transmitted from the drive pulley 54 to the rear wheel Wr via the V-belt 64, the driven pulley 59, the starting clutch 63, and the reduction gear train 67.

Upon low speed rotation of the engine E, since the centrifugal force applied to the centrifugal weight 57 of the drive pulley 54 is small, the groove width between the fixed side pulley half 60 and the movable side pulley

half 61 is reduced by the biasing force of the spring 62 of the driven pulley 59, with a result that the speed change ratio becomes the "LOW" ratio. As the rotational number of the crank shaft 31 is increased from such a state, the centrifugal force applied to the centrifugal weight 57 is increased, so that the groove width between the fixed side pulley half 55 and the movable side pulley half 56 of the drive pulley 54 is reduced and correspondingly the groove width between the fixed side pulley half 60 and the movable side pulley half 61 of the driven pulley 59 is increased. As a result, the speed change ratio is continuously variably changed from the ratio "LOW" to the ratio "TOP".
As is apparent from Figs. 3 and 4, a lower front portion of the radiator 49 is connected to the thermostat cover 521 by a cooling water pipe line 71; the thermostat case 52 is connected to the first engine block 32 by a cooling water pipe line 72; and the cylinder head 34 is connected to an upper rear portion of the radiator 49 by a cooling water pipe line 73.
In a state in which the warming operation of the engine has been completed, cooling water discharged from

the cooling water pump 53 is supplied to a water jacket provided in the first engine block 32 and the cylinder head 34 via the thermostat case 52 and the cooling water pipe line 72. During passing through the water jacket, the cooling water cools the engine E. Then, the cooling water is supplied to the radiator 49 via the cooling water pipe line 73. During passing through the radiator 49, the temperature of the cooling water is reduced. The cooling water is then returned to the cooling water pump 53 via the cooling water pipe line 71 and the thermostat 51. During warming operation of the engine E, that is, when the temperature of the cooling water is low, the thermostat 51 is operated to allow the cooling water to be circulated in the engine E not by way of the radiator 49, so that the temperature of the cooling water is rapidly increased.
In this way, the accessories for cooling the engine such as the radiator 49, the cooling fan 50, the thermostat 51, the cooling water pump 53, and the cooling water pipe lines 71, 72 and 73 are concentratedly arranged on the right side surface of the engine E. As a result, the accessories can be efficiently mounted/dismounted along one direction without largely

changing the posture of the engine E upon assembly or maintenance, and further the lengths of the cooling water pipe lines 71, 72 and 73 can be minimized.
In particular, since the belt-type continuously variable transmission T is separable from the engine E, it is possible not only to facilitate the transportation of the engine E and the change in posture of the engine E, but also to make stable the posture of the engine E in such a manner as to allow the accessories to be easily mounted/dismounted, by supporting the engine E while directing downwardly the parting plane P6 to which the belt-type continuously variable transmission T is connected. Since the timing chain 45 for driving the cam shaft 44 and the cooling water pump 53 is also disposed on the right side surface of the engine E, the timing chain 45 can be assembled simultaneously with the assembly of the cooling water pump 53, to thereby further improve the workability. Further, as compared with the conventional integral structure in which the engine block is not separable from the transmission casing, it is possible not only to miniaturize individual parts and hence to reduce the cost required for the molds, but also to combine a plurality of kinds of engines with a


plurality of kinds of transmissions in various manners and hence to improve the general versatility. -
The engine block is divided along the axial line of the crank shaft 31 into the first and second engine blocks 32 and 33, and further the cylinder 41, the piston 42, the connecting rod 43, and the crank shaft 31 can be previously assembled to the first engine block 32 side, and accordingly, it is possible to facilitate the assembly of the engine E. As is apparent from Fig. 3 and Figs. 5 to 7, the first and second engine blocks 32 and 33 are integrally connected to the first transmission casing 37 with two bolts 74 and two bolts 75 screwed from the first transmission casing 37 side. The heads of the front side two bolts 74 for connecting the first transmission casing 37 to the first engine block 32 and the head of the lower rear side one bolt 75 for connecting the first transmission casing 37 to the second engine block 33 are exposed outside the belt-type continuously variable transmission T. The head of the upper rear side one bolt 75 for connecting the first transmission casing 37 to the second engine block 33 is covered with the second


transmission casing 38 and is not viewed from the outside of the belt-type continuously variable transmission T.
A circular opening 76 (see Fig. 5) centered at the crank shaft 31 is formed in the left side surfaces of the first and second engine blocks 32 and 33. A circular opening 77 (see Figs. 6 and 7) centered at the crank shaft 31 is also formed in the first transmission casing 37 . When the first and second engine blocks 32 and 33 are connected to the first transmission casing 37, an annular seat 78 formed at the peripheral edge of the opening 76 formed in the first and second engine blocks 32 and 33 is brought into contact with an annular seat 19 formed at the peripheral edge of the opening 77 formed into the first transmission casing 37 via an annular seal member 80 (see Fig. 3). The diameter of the opening 77 of the first transmission casing 37 is slightly larger than the maximum diameter of the drive pulley 54 of the belt-type continuously variable transmission T, and accordingly, the drive pulley 54 is allowed to pass through the opening 77 of the first transmission casing 37.
Two bosses 81 and two bosses 82, through which the front side two bolts 74 pass, project from the first

engine block 32 and the first transmission casing 37, respectively. Two bosses 83 and two bosses 84, through which the rear side two bolts 75 pass, project from the second engine block 33 and the first transmission casing 37, respectively.
Accordingly, when the first and second engine blocks 32 and 33 are connected to the first transmission casing 37 with the four bolts 74 and 75, the four bosses 81 and 83 of the first and second engine blocks 32 and 33 are brought into contact with the four bosses 82 and 84 of the first transmission casing 37, respectively. In Figs. 5 and 6, the portions at which the first and second engine blocks 32 and 33 are in contact with the first transmission casing 37 are designated by crosshatching.
Spaces S (see Fig. 3) constituting heat insulating air layers are formed between the seat 78 of the first and second engine blocks 32 and 33 and the seat 79 of the first transmission casing 37, which are in contact therewith, and between the bosses 81 and 83 of the first and second engine blocks 32 and 33 and the bosses 82 and 84 of the first transmission casing 37, which are in contact therewith. By forming the spaces S constituting

the heat insulating air layers between the first and second engine blocks 32 and 33 and the first transmission casing 37 as described above, it is possible to prevent the heat transfer from the engine E to the belt-type continuously variable transmission T, and hence to ensure the durability of the V-belt 64 being weak against heat without increasing the cooling function of the belt-type continuously variable transmission T so much.
As shown in Fig. 11, upon assembly of the power unit P, the drive pulley 54 of the belt-type continuously variable transmission T is assembled with the crank shaft 31 of the engine E previously sub-assembled, and then the first and second engine blocks 32 and 33 are connected to the first transmission casing 37 with the four bolts 74 and 75. At this time, since the diameter of the opening 77 of the first transmission casing 37 is larger than the maximum outside diameter of the drive pulley 54 assembled with the crank shaft 31, the first and second engine blocks 32 and 33 can be easily connected to the first transmission casing 37, to thereby enhance the assembling performance.
As is apparent from Figs. 2 and 3, the kick shaft


26 and a starter shaft 85 of the kick-type starter 25 are supported in cantilever by the second transmission casing 38 positioned outside the vehicular body. The kick shaft 26 projects outwardly from the second transmission casing 38, and the starter shaft 85 is coaxially opposed to the end of the crank shaft 31. A sector gear 87 fixed to the kick shaft 26 biased to its original state meshes with a pinion 88 integrally formed on the starter shaft 85. The starter shaft 85 is supported in such a manner as to be axially movable close to or apart from the crank shaft 31. When moved close to the crank shaft 31 against the biasing force of the spring 86, the starter shaft 85 is allowed to mesh with the end of the crank shaft 31.
When the kick pedal 27 is kicked, the rotation of the kick shaft 26 is transmitted to the starter shaft 85 via the sector gear 97 and the pinion 88, so that the starter shaft 85 is rotated and axially moved to mesh with the end of the crank shaft 31. As a result, the crank shaft 31 is cranked by the starter shaft 85, to start the engine E.
Since the kick shaft 26 is supported in cantilever by the second transmission casing 85 positioned outside

the vehicular body, the V-belt 64 contained in the first and second transmission casings 37 and 38 does not interfere with the kick shaft 26. Accordingly, the position of the kick shaft 26 can be sufficiently moved upwardly. As is apparent from Fig. 2, the position of the kick shaft 26 is located over a line L1 connecting the center of the drive pulley 54 of the belt-type continuously variable transmission T (the axis of the crank shaft 31) to the center of the driven pulley 59 of the transmission T (the axis of the output shaft 58), and also located over a line L2 passing through the center of the drive pulley 54 and extending in parallel to a road surface. Although the kick shaft 26 is overlapped to the V-belt 64, such a kick shaft 26 does not interfere with the V-belt 64 because it is supported in cantilever by the second transmission casing 38 (see Fig. 3).
As shown in Fig. 7, the upper surfaces of the first and second transmission casings 37 and 38 partially project, to form a projecting portion 90. The boss 84, which allows the upper side bolt 75 for connecting the first transmission casing 37 to the second engine block 33 to pass therethrough, is disposed inside the first casing 37 positioned at the projecting portion 90. When

the kick pedal 27 is kicked and the sector gear 97 is rotated clockwise in Fig. 7 together with the kick shaft 26, the sector gear 97 is contained in the projecting portion 90, whereby it does not interfere with the upper walls of the first and second transmission casings 37 and 38. Since the boss 84 of the upper side bolt 75 and the sector gear 97 of the kick-type starter 25 are contained in the projecting portion 90 formed by part of the upper surfaces of the first and second transmission casings 37 and 38 as described above, it is possible to compactly dispose the boss 84 and the sector gear 97 while minimizing the enlargement of the first and second transmission casings 37 and 38.
As shown in Figs. 8 and 9, a pair of right and left bolts 92 are supported by the center frame 13 via rubber bushes 91, and right and left link plates 93 and 94 are swingably supported by the bolts 92. Stopper rubbers 96 are mounted in two box-like stopper rubber supporting members 95 provided on the outer side surface of the link plate 93 positioned on the left side of the vehicular body. Two receiving planes 131 and 132 to be in contact with the stopper rubbers 96 are formed on the center frame 13. The right and left link plates 93 and 94 are


integrally connected to each other via a connecting rod 97 and the pivot 15. As shown in Fig. 5, a right hanger bracket 98R projects forwardly, upwardly from the upper surface of the crank case half 322 of the first engine block 32 composed of the cylinder block 321, and the crank case half 322. As shown in Fig. 6, a left hanger bracket 98L projects forwardly, upwardly from the upper surface of the first transmission casing 37. The right and left hanger brackets 98R and 98L are supported by the pivot 15 via rubber bushes 99.
A load inputted from the power unit P to the pivot 15 via the right and left hanger brackets 98R and 98L is absorbed by elastic deformation of the rubber bushes 99 for supporting the pivot 15, and is also absorbed by elastic deformation of the stopper rubbers 96 which are pressed on the receiving planes 131 and 132 of the center frame 13 by swing motion of the link plates 93 and 94 around the bolts 92. The above load is also absorbed by elastic deformation of the rubber bushes 91 for supporting the bolts 92 on the center frame 13.
As is apparent from Fig. 5, since the right hanger bracket 98R is integrally formed on the crank case half

322 integrally formed on the cylinder block 32l such a right hanger bracket 98R is allowed to project upwardly from the cylinder block 321 to be made sufficiently close to the parting plane P2 to which the cylinder head 34 is connected.
If the cylinder block and the crank case are formed by separate members and are connected to each other along a parting plane, the hanger bracket provided on the crank case cannot extend to the cylinder block side over the parting plane because the parting plane of the crank case must be machined, with a result that the hanger bracket cannot project upwardly from the cylinder block to be made close to the cylinder head.
Since the left hanger bracket 98L provided on the first transmission casing 37 can freely extend forwardly of the vehicular body, it is formed symmetrically with the right hanger bracket 98R on the left and right sides.
Since a distance d (see Fig. 5) between the axial line of the crank shaft 31 and the pivot 15 positioned forwardly of the crank shaft 31 can be sufficiently largely ensured as described above, a distance between


the pivot 15 and the cylinder head 34 portion at the front end of the engine E is reduced, and accordingly, when the power unit P is vertically swung around the pivot 15, the movement range of the cylinder head 34 portion of the engine E in the vertical direction is reduced. As a result, it is possible to effectively avoid the interference of the front portion of the engine E with another member such as a step floor of the vehicular body. As is apparent from Figs. 2 and 10, the carburetor 24 disposed between the helmet case 17 and the right and left hanger brackets 98R and 98L is positioned directly after the pivot 15. Accordingly, since the right and left hanger brackets 98R and 98L and the pivot 15 are disposed close to the cylinder head 34, the carburetor 24 can be made close to the cylinder head 34, As a result, it is possible to shorten the length of the intake pipe 40 for connecting the carburetor 24 to the cylinder head 34 and hence to reduce the intake resistance in the intake pipe 40. This contributes to the improvement of the output of the engine E.
While the embodiment of the present invention will

be described in detail, the present invention is not limited thereto, and it is to be understood that many changes in design may be made without departing from the scope of the present invention.
For example, description has been made of the swing type power unit P of the motorcycle V in the above embodiment; however, the swing-type power unit P of the present invention can be applied to a motor-tricycle. In the above embodiment, the first transmission casing 37 is separable from the first and second engine blocks 32 and 33; however, the engine block and the transmission casing can be integrated with each other. Further, only the right hanger bracket 98R is provided on the first engine bracket 32 in the above embodiment; however, the right and left hanger brackets 98R and 98L can be both provided on the first engine block 32. [Effect of the Invention]
As described above, according to the present invention described in claim 1, since the engine block is divided into the first and second engine blocks, and the hanger bracket for pivotably supporting the engine on the body frame via the pivot is integrally formed on the half

of the crank case of the first engine block composed of the cylinder block and the half of the crank case, it is possible to make the position of the pivot sufficiently close to the cylinder head without obstructing the machining. As a result, the movement range of the cylinder head in the vertical direction by the swing motion of the engine around the pivot is reduced, so that it is possible to avoid the interference of the cylinder head with another member such as a step floor.
According to the invention described in claim 2, since the carburetor is disposed directly after the pivot provided sufficiently close to the cylinder head, it is possible to shorten the length of the intake pipe for connecting the carburetor to the cylinder head, and hence to enhance the output of the engine.
[Explanation of Characters]
E: engine, F: body frame, T: belt-type continuously variable transmission (transmission), Wr: rear wheel (drive wheel), 15: pivot, 24: carburetor, 32: first engine block (engine block), 321:cylinder block, 322:
half of crank case, 33: second engine block (engine block), 34: cylinder head, 40: intake pipe, 98R: right hanger bracket (hanger bracket)

We claim:
1. A swing-type power unit swingably supported by a body frame (F) of
a motorcycle or a motor-tricycle comprising:
an engine (E) including an engine block (32, 33); and
a transmission (T) for transmitting a drive force of said engine (E) to a drive wheel (Wr), said transmission (T) being integrally connected to said engine (E);
wherein said engine block (32, 33) is divided into a first engine block (32) having a cylinder block (321) extending forwardly of a vehicular body and being connected to a cylinder head (34) and a half (322) of a crank case, and a second engine block (33) having the other half of said crank case; and
a hanger bracket (98R) for pivotably supporting said engine (E) on said body frame (F) via a pivot (15) is integrally formed on said half (322) of said crank case of said first engine block (32),
a hanger bracket (98R) is disposed to circumference of a cylinder block (321).
2. A swing-type power unit as claimed in claim 1, wherein a carburetor (24) is disposed directly after said pivot (15), and said carburetor (24) and said cylinder head (34) are connected to each other via an intake pipe (40).
3. A swing-type power unit substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
Dated this 10th day of January, 2000.
(Dr. RAMESH KUMAR MEHTA)
OF REMFRY 8 SAGAR
ATTORNEY FOR THE APPLICANTS

Documents:

27-mum-2000-cancelled pages(28-09-2004).pdf

27-mum-2000-claims(granted)-(28-09-2004).pdf

27-mum-2000-correspondence(15-02-2007).pdf

27-mum-2000-correspondence(ipo)-(11-04-2003).pdf

27-mum-2000-drawing(28-09-2004).pdf

27-mum-2000-form 1(10-01-2000).pdf

27-mum-2000-form 2(granted)-(28-09-2004).pdf

27-mum-2000-form 3(10-01-2000).pdf

27-mum-2000-form 3(23-09-2004).pdf

27-mum-2000-form 4(30-06-2004).pdf

27-mum-2000-form 5(10-01-2000).pdf

27-mum-2000-petition under rule 137(23-09-2004).pdf

27-mum-2000-power of attorney(11-04-2000).pdf

27-mum-2000-power of attorney(23-09-2004).pdf

abstract1.jpg


Patent Number 204328
Indian Patent Application Number 27/MUM/2000
PG Journal Number 23/2007
Publication Date 08-Jun-2007
Grant Date 15-Feb-2007
Date of Filing 10-Jan-2000
Name of Patentee HONDA GIKEN KOGYO KABUSHIKI KAISHA
Applicant Address BUSINESS AT 1-1, MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO,
Inventors:
# Inventor's Name Inventor's Address
1 YOSHIYUKI SEKIYA AND AKIO YAGASAKI C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA,
PCT International Classification Number B 62 M
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 HEI - 11 - 007854 1999-01-14 Japan