Title of Invention

"FLOOR STRUCTURE FOR MOTORCYCLE"

Abstract

A floor structure for a motorcycle, characterized in that a floor member (52) having floor surface (53) for placing a foot of the rider is joined to a vehicle body cover ( C ) fixedly supported on a vehicle body frame (F) on which an engine (E) is supported, the floor member (52) has an opening (55) which is open in said floor surface (53), a step plate (56) supported on the vehicle body frame (F) by an elastic support member (57) is disposed in said opening (55), with a gap (g) provided between the step plate (56) and an inner peripheral edge of said opening (55) for allowing said elastic support member (57) to be elastically deformed, and a flexible floor mat (60) is laid from said floor surface (53) to said step plate (56) in covering relation to upper surfaces of said floor surface (53) and said step plate (56) and said gap (g). Fig. 6

Full Text

[Name of Document] Specification [Title of the Invention] Floor structure for motorcycle [Technical Field] [0001] The present invention relates to an improvement in a floor structure for a motorcycle wherein a step plate placing a foot of the rider is mounted by a support member on a vehicle body frame which supports an engine for blocking, as much as possible, the transmission of vibrations from the engine. [Background Art] [0002] Such a floor structure for a motorcycle is already known as disclosed in Patent Document 1 given below, for example. [Patent Document 1] Japanese Utility Model Laid-open No. Sho 59-35287 [Disclosure of the Invention] [Problems to be Solved by the Invention] [0003] In the floor structure disclosed in Patent Document 1 given above, a floor is constructed in its entirety of a step plate that is elastically supported on a vehicle body frame, and a gap for preventing the step plate and a vehicle body cover from interfering with each other when the elastic support member is deformed is provided between the step plate and the vehicle body cover erected adjacent to the step plate. Since the gap is visible from outside, the floor structure is not of a good appearance. In addition, while the motorcycle is running, muddy water or the like splashed by the front wheel tends to pass through the gap from below and smear the upper surface of the step plate. [0004] The present invention has been made in view of above drawbacks. It is an object of the present invention to provide a floor structure for a motorcycle which employs a structure elastically supporting a step plate on a vehicle body frame, and is of an improved appearance and can prevent muddy water or the like from smearing the step plate and a floor surface. [Means for Solving the Problems] [0005] To achieve the above object, a floor structure for a motorcycle according to the present invention has a first feature in that a floor member having a floor surface for placing a foot of the rider is joined to a vehicle body cover fixedly supported on a vehicle body frame on which an engine is supported, the floor member has an opening which is open in the floor surface, a step plate supported on the vehicle body frame by an elastic support member is disposed in the opening, with a gap provided between the step plate and an inner peripheral edge of the opening for allowing the elastic support member to be elastically deformed, and a flexible floor mat is laid from the floor surface to the step plate in covering relation to upper surfaces of the floor surface and the step plate and the gap. [0006] In addition to the first feature, the present invention provides a second feature in that an auxiliary floor surface of the floor surface, which extends rearwardly from a rear end of the opening, is inclined rearwardly upwardly, and bulging ends bulging leftwardly and rightwardly from a crankcase of the engine are disposed directly below the auxiliary floor surface. [0007] In addition to the second feature, the present invention provides a third feature in that the bulging end houses therein a torque converter mounted on an end of a crankshaft of the engine. [0008] In addition to the second feature, the present invention provides a fourth feature in that the bulging end houses therein a generator actuatable by an end of a crankshaft of the engine. [Effects of the Invention] [0009] According to the first feature of the present invention, since the elastic support member absorbs vibrations of the engine under its elasticity, the transmission of vibrations from the engine to the step plate can be prevented as much as possible. Though the elastic support member is elastically deformed, the step plate and the floor member are prevented from interfering with each other by the gap. [0010] Since the floor surface of the floor member spreads around the step plate, a wide space is provided for placing the foot of the rider therein for increased riding comfort. [0011] As the floor mat conceals the gap between the step plate and the floor member in covering relation to the floor surface of the floor member and the upper surface of the step plate, the appearance can be improved. The floor mat is effective to prevent foreign matter such as muddy water splashed from the front wheel from passing through the gap from below, so that the floor mat, the step plate, and the floor surface are prevented from being smeared. Because the floor mat is flexible, the step plate and the floor member are allowed to be displaced relatively to each other when the elastic support member is elastically deformed. [0012] According to the second feature of the present invention, the auxiliary floor surface can be expanded without interference with the left and right protrusions of the crankcase of the engine for better riding comfort. [0013] According to the third feature of the present invention, the auxiliary floor surface can be expanded without interference with the bulging end of the crankcase which houses the torque converter for better riding comfort. [0014] According to the fourth feature of the present invention, the auxiliary floor surface can be expanded without interference with the bulging end of the Crankcase which houses the generator for better riding comfort. The present invention relates to a floor structure for a motorcycle, characterized in that a floor member (52) having floor surface (53) for placing a foot of the rider is joined to a vehicle body cover ( C ) fixedly supported on a vehicle body frame (F) on which an engine (E) is supported, the floor member (52) has an opening (55) which is open in said floor surface (53), a step plate (56) supported on the vehicle body frame (F) by an elastic support member (57) is disposed in said opening (55), with a gap (g) provided between the step plate (56) and an inner peripheral edge of said opening (55) for allowing said elastic support member (57) to be elastically deformed, and a flexible floor mat (60) is laid from said floor surface (53) to said step plate (56) in covering relation to upper surfaces of said floor surface (53) and said step plate (56) and said gap (g). [Best Mode for Carrying Out the Invention] [0015] An embodiment of the present invention will be described below with reference to the accompanying drawings. [Brief Description of the Drawings] [0059] [FIG. 1] FIG. 1 is a side elevational view of a motorcycle according to the present invention. [FIG. 2] FIG. 2 is a side elevational view of the motorcycle with a vehicle body cover removed. [FIG. 3] FIG. 3 is a view as viewed in the direction indicated by the arrow 3 in FIG. 1. [FIG. 4] FIG. 4 is a plan view of parts around an auxiliary frame. [FIG. 5] FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 1. [FIG. 6] FIG. 6 is an exploded perspective view of a portion of the vehicle body cover. [FIG. 7] FIG. 7 is a cross-sectional view taken along line 7 - 7 of FIG. 3. [FIG. 8] FIG. 8 is a cross-sectional view taken along line 8 - 8 of FIG. 3. [FIG. 9] FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 3. [FIG. 10] FIG. 10 is a cross-sectional view taken along line 10 - 10 of FIG. 3. [FIG. 11] FIG. 11 is a cross-sectional view taken along line 11 - 11 of FIG. 3. [FIG. 12] FIG. 12 is a cross-sectional view taken along line 12 - 12 of FIG. 11. [FIG. 13] FIG. 13 is an enlarged vertical cross-sectional view of an area 13 in FIG. 11. [FIG. 14] FIG. 14 is a vertical sectional side elevational view of an air cleaner (a cross-sectional view taken alone line 14 - 14 of FIG. 15). [FIG. 15] FIG. 15 is a cross-sectional view taken along line 15 - 15 of FIG. 14. [FIG. 16] FIG. 16 is a cross-sectional view taken along line 16 - 16 of FIG. 15. [FIG. 17] FIG. 17 is a side elevational view of parts around an oil cooler.' [FIG. 18] FIG. 18 is a cross-sectional view taken along line 18 - 18 of FIG. 17. [0016] FIG. 1 is a side elevational view of a motorcycle according to the present invention. FIG. 2 is a side elevational view of the motorcycle with a vehicle body cover removed. FIG. 3 is a view as viewed in the direction indicated by the arrow 3 in FIG. 1. FIG. 4 is a plan view of parts around an auxiliary frame. FIG. 5 is a cross-sectional view taken along line 5 - 5 of FIG. 1. FIG. 6 is an exploded perspective view of a portion of the vehicle body cover. FIG. 7 is a cross-sectional view taken along line 1 - 1 of. FIG. 3. FIG. 8 is a cross-sectional view taken along line 8 - 8 of FIG. 3. FIG. 9 is a cross-sectional view taken along line 9 - 9 of FIG. 3. FIG. 10 is a cross-sectional view taken along line 10 - 10 of FIG. 3. FIG. 11 is a cross-sectional view taken along line 11 - 11 of FIG. 3. FIG. 12 is a cross-sectional view taken along line 12 - 12 of FIG. 11. FIG. 13 is an enlarged vertical cross-sectional view of an area 13 in FIG. 11. FIG. 14 is a vertical sectional side elevational view of an air cleaner (a cross-sectional view taken alone line 14 - 14 of FIG. 15). FIG. 15 is a cross-sectional view taken along line 15 - 15 of FIG. 14. FIG. 16 is a cross-sectional view taken along line 16 -16 of FIG. 15. FIG. 17 is a side elevational view of parts around an oil cooler. FIG. 18 is a cross-sectional view taken along line 18 - 18 of FIG. 17. [0017] Front, rear, left, and right in the description below are referred to with respect to a motorcycle. [0018] In FIGS. 1 through 4, a motorcycle M has a vehicle body frame F, a front fork 1 steerably supported on a front end of the vehicle body frame F and supporting a front wheel Wf with a shaft, a rear fork 2 vertically swingably pivoted on a rear portion of the vehicle body frame F and supporting a rear wheel Wr, an engine E supported on the vehicle body frame F between the front wheel Wf and the rear wheel Wr, a luggage box 3 of synthetic resin supported on the vehicle body frame F, a fuel tank 4 mounted on the vehicle body frame F immediately behind the luggage box 3, a tandem seat 5 doubling as a lid of the luggage box 3 and covering the fuel tank 4, and a vehicle body cover C of synthetic resin mounted on the vehicle body frame F in covering relation to the vehicle body frame F, the engine E, and the luggage box 3. The luggage box 3 functions as a support base of the seat 5. To the engine E, there are connected a carburetor 6, an air cleaner 7, and an oil cooler 8. A steering handle 18 is connected to a handle stem which extends upwardly from the front fork 1. [0019] The above components of the motorcycle M will successively be described below. [0020] As shown in FIGS. 2 through 4, the vehicle body frame F comprises a main frame Fm having a head pipe 10 on its front end which supports the front fork 1, and an auxiliary frame Fs removably coupled to the main frame Fm. The main frame Fm comprises a main pipe 11 extending rearwardly downwardly from the head pipe 10, and a pair of left and right rear pipes 12, 12 coupled respectively to left and right side surfaces of a rear end portion of the main pipe 11. The rear pipes 12, 12 have their rear ends connected integrally to each other. [0021] In the vehicle body frame F, the main pipe 11 has a rear half extending rearwardly downwardly at a smaller angle than a front half thereof, i.e., extending nearly horizontally. The main pipe 11 has a rear end terminating short of a front end of a bottom wall 3b of the luggage box 3 . [0022] The rear pipes 12, 12 are connected to the rear end of the main pipe 11. The rear pipes 12, 12 have a rear frame front portion extending rearwardly downwardly at an angle close to the horizontal direction, like the rear half of the main pipe 11, and a rear frame rear portion bent upwardly from the rear end of the rear frame front portion along a front surface of the rear wheel Wr and then extending further rearwardly. To a cross member 65 mounted on the rear frame front portion, there are fixed a pair of left and right engine hangers 14, 14 projecting downwardly. The engine E disposed forwardly of center brackets 13, 13 is fixedly supported on the center brackets 13, 13 and the engine hangers 14, 14 by a plurality of hanger bolts 3 0 (see FIG. 12). [0023] The rear fork 2 is vertically swingably coupled to the center brackets 13, 13 by a horizontal pivot shaft 15 A chain transmission device 16 for transmitting power between the engine E and the rear wheel Wr is disposed in surrounding relation to the rear fork 2. A rear cushion 17 is interposed between a rear end portion of the rear fork 2 and the rear pipes 12, 12. [0024] The auxiliary frame Fs comprises a pair of left and right L-shaped side pipes 20, 20, a cross pipe 21 interconnecting lower front end portions of the side pipes 20, 20 with a joint bracket 19 (see FIG. 17), and a pair of left and right floor support pipes 22, 22 having opposite ends coupled to both left and right ends of the cross pipe 21 and intermediate portions of the left and right side pipes 20, 2 0 and extending outwardly to the left and right. A plurality of first support brackets 23 disposed on front and rear portions of the floor support pipes 22, 22 and a plurality of second support brackets 24 disposed on intermediate portions of the floor support pipes 22, 22 are welded to upper surfaces of the floor support pipes 22, 22. Front joint plates 25, 25 and rear joint plates 26, 26 are integrally formed with upper end portions and rear end portions of the side pipes 20, 20. The left and right front joint plates 25, 25 are removably coupled by bolts 31 to left and right side surfaces of the main pipe 11. The left and right rear joint plates 26, 26 are removably coupled by bolts 32 to the center brackets 13, 13. [0025] Before the auxiliary frame Fs is coupled to the main frame Fm, the air cleaner 7 and the oil cooler 8 are installed on the auxiliary frame Fs, as described later in detail. [0026] As shown in FIGS. 2, 5, and 17, the engine E comprises a crankcase 28 housing and supporting a crankshaft 27 lying horizontally with its opposite ends directed to the left and right, and a single-cylinder cylinder block 29 coupled to the crankcase 28 and inclined forwardly in a substantially horizontal state. The carburetor 6 is connected by an elbow-shaped intake pipe 41 to an upper surface of a cylinder head 40 which is joined to an end face of the cylinder block 29. The intake pipe 41, the carburetor 6, and the air cleaner 7 jointly make up an intake system of the engine E. The intake system extends upwardly and forwardly of the cylinder head 40. [0027] The crankcase 2 8 has bulging ends 2 8a, 2 8b formed on respective left and right ends thereof and extending outwardly beyond left and right side surfaces of the cylinder block 29. The bulging end 28a houses therein a torque converter 42 and a starter clutch 43 which are mounted on an end of the crankshaft 27. The other bulging end 2 8b houses therein an outer-rotor generator 44 which is actuatable by the other end of the crankshaft 27. A starter motor 45 is mounted on a central portion of the upper surface of the crankcase 28. [0028] In FIGS. 1 and 3 through 8, the vehicle body cover C is made of synthetic resin and has an engine cover 50 of inverted U-shaped cross section covering the main pipe 11 and the engine E from above and a pair of left and right leg shields 51, 51 joined to the front end of the engine cover 50. A pair of left and right floor members 52, 52 of synthetic resin is joined to the engine cover 50 and the leg shields 51, 51. The floor members 52, 52 comprise respective side walls 52a connected to the lower end of the engine cover 50, respective floor panels 52b extending from the lower ends of the side walls 52a outwardly to the left and right, and respective skirts 52c bent downwardly from the outer ends of the floor panels 52b. The side wall 52a of the right floor member 52 has an engine inspection window 49. [0029] The floor panels 52b have respective floor surfaces 53 comprising respective horizontal main floor surfaces 53m disposed in side regions of the cylinder block 29 as viewed in side elevation and respective auxiliary floor surfaces 53s inclined rearwardly upwardly from the rear ends of the main floor surface 53m and extending to left and right sides of the luggage box 3. [0030] As shown in FIGS. 4 and 8, the floor members 52, 52 are fixed by bolts 33 to the first support brackets 23 of the floor support pipes 22, 22 on the same sides. The bolts 33 have respective heads disposed in recesses 54 defined in the main floor surfaces 53m so that the heads do not project into the main floor surfaces 53m. The floor members 52, 52 have respective rear ends fixed by bolts 34 to the rear pipes 12, 12 of the main frame Fm (see FIGS. 3 and 10). [0031] The floor members 52, 52 have longitudinally elongate rectangular openings 55 (see FIG. 6) that are open in the main floor surfaces 53m. Step plates 56 that are elastically supported on the floor support pipes 22, 22 on the same sides are disposed in the openings 55. Specifically, as shown in FIGS. 4 and 7, each step plate 56 is mounted by bolts 3 5 on the second support brackets 24, 24 ••• of the floor support pipe 22 on the same side with an elastic support member 57 interposed therebetween. The bolts 35 have heads disposed in recesses 58 defined in an upper surface of the step plate 56 so that the bolts 35 do not project into the upper surface of the step plate 56. The elastic support member 57 is interposed between the second support brackets 24 and the step plate 56, and preloaded by tightening the bolts 35 that extend through the step plate 56, the elastic support member 57, and the second support brackets 24. To limit the preload, collars 59 are fitted over the shanks of the bolts 35 and interposed between the heads of the bolts 35 and the second support brackets 24. [0032] The step plate 56 is of a longitudinally elongate rectangular shape as with the openings 55 that are open in the main floor surfaces 53m. A gap g for allowing the elastic support member 57 to be elastically deformed is defined between the step plate 56 and the inner peripheral edge of the opening 55. The step plate 56 is disposed such that the upper surface thereof lies flush with the main floor surface 53m. [0033] A floor mat 60 made of a flexible material such as rubber or the like is laid entirely over the floor surface 53 of the floor members 52, 52, i.e., the main floor surface 53m, the auxiliary floor surface 53s, and the step plate 56. The floor mat 60 covers the gap g between the step plates 56 and the floor members 52, 52. As shown in FIG. 9, the floor mat 60 has a plurality of locking fingers 61, 61 ••• projecting from the lower surface thereof and elastically fitted in respective locking holes 62, 62 -•• defined in the step plates 56 and the floor panels 52b of the floor members 52, 52. Thus, the floor mat 60 is retained on the step plate 56 and the floor panel 52b. [0034] While the motorcycle M is being driven, vibrations of the engine E are transmitted to the vehicle body frame F which supports the engine E. Since the elastic support member 57 elastically absorbs the vibrations, the vibrations of the engine E are prevented, as much as possible, from being transmitted from the vehicle body frame F to the step plates 56. Though the elastic support member 57 is elastically deformed, the step plates 56 and the floor members 52, 52 are prevented from interfering with each other by the gap g. [0035] Since the floor surface 53 of the floor members 52, 52 spreads around the step plate 56, a wide space is provided for placing the foot of the rider therein for increased riding comfort. [0036] As the floor mat 6 0 conceals the gap g between the step plate 56 and the floor members 52, 52 in covering relation to the floor surface 53 of the floor members 52, 52 and the upper surface of the step plate 56, the appearance of the motorcycle M can be improved. The floor mat 60 is effective to prevent foreign matter such as muddy water splashed from the front wheel Wf from passing through the gap g from below, so that the floor mat 60, the step plate 56, and the floor surface 53 are prevented from being smeared. Because the floor mat 60 is flexible, the step plate 56 and the floor members 52, 52 are allowed to be displaced relatively to each other when the elastic support member 57 is elastically deformed. [0037] The auxiliary floor surfaces 53s extending rearwardly from the rear ends of the openings 55 in the left and right floor members 52, 52 are inclined rearwardly upwardly. The bulging end 2 8a of the crankcase 28 of the engine E which houses the torque converter 42 and the starter clutch 43 therein, and the bulging end 28b thereof which houses the outer-rotor generator 44 therein are disposed directly below the auxiliary floor surfaces 53s. Therefore, the auxiliary floor surfaces 53s can be extended to the left and right sides of the luggage box 3 without interference with the bulging ends 28a, 28b, allowing the rider to place the legs, with the knees bent, on the auxiliary floor surfaces 53s for better riding comfort. [0038] In FIGS. 11 through 13, the luggage box 3 is mounted on the left and right rear pipes 12, 12 of the main frame Fm with its bottom disposed between the left and right rear pipes 12, 12. Specifically, a pair of left and right front attachment brackets 66, 66 is fixed to a rear surface of the cross member 65 which interconnects the front ends of the left and right rear pipes 12, 12, and a pair of left and right rear attachment brackets 67, 67 is fixed to upper portions of the rear pipes 12, 12. The bottom wall 3b of the luggage box 3 is mounted on the front attachment brackets 66, 66 by bolts 36 with elastic support members 68 interposed therebetween, and flanges 3a integrally projecting from an upper rear surface of the luggage box 3 are mounted on the rear attachment brackets 67, 67 by bolts 37 with elastic support members 6 9 interposed therebetween. A cross member 65' interconnecting portions of the left and right rear pipes 12, 12 where they start bending upwardly is connected to the left and right rear pipes 12, 12. The bottom wall 3b of the luggage box 3 is disposed closely to the cross member 65', increasing the depth of the luggage box 3 as much as possible. [0039] The luggage box 3 thus mounted between the left and right rear pipes 12, 12 is deeper particularly on the rear portion of the bottom wall 3b for a large storage capacity without being obstructed by the rear pipes 12, 12. Specifically, the bottom wall 3b of the luggage box 3 is inclined rearwardly downwardly along the upper surface of the front portion of the rear frame which is inclined rearwardly downwardly nearly horizontally. The luggage box 3 allows a full-face helmet H to be stored therein in a rearwardly downward attitude with its lower opening directed downwardly. The luggage box 3, whose storage capacity is large enough to store the full-face helmet H, is thus effective to prevent the seat 5 from increasing in height. [0040] An ancillary box 70 which projects downwardly and is open in its upper surface is integrally formed with a central portion of the bottom wall 3b of the luggage box 3. The ancillary box 70 is disposed between the cross members 65, 65'. The ancillary box 70 houses an accessory such as battery 71 or the like therein. A lid 72 for opening and closing the ancillary box 70 is mounted on the bottom wall 3b of the luggage box 3 by a hinge pin 73 The lid 72 has a distal end that can be fixed to the bottom wall by a screw 38. The lid 72 has a central portion bulging into the luggage box 3 for increasing an effective storage capacity of the ancillary box 70. The bulging portion 72a is placed in a hollow in the helmet H that is stored in the luggage box 3, and hence does not interfere with the helmet H. [0041] The seat 5 is mounted on an upper front end of the luggage box 3 by a hinge pin 63 for opening and closing the opening of the luggage box 3. A latch 64 for keeping the opening of the luggage box 3 closed is disposed between the seat 5 and the rear end of the rear pipes 12, 12. [0042] The luggage box 3 and the engine E are disposed such that the bottom wall 3b and the crankcase 2 8 are vertically adjacent to each other. This layout of the luggage box 3 and the engine E is made possible by making the rear end of the main pipe 11 terminating short of the front end of the bottom wall 3b of the luggage box 3 and also making the bottom wall 3b of the luggage box 3 extending along the upper surface of the rear frame front portion, inclined rearwardly downwardly nearly horizontally, of the rear pipes 12, 12, thus providing a wide space out of interference with the main pipe 11 beneath the bottom wall 3b, and effectively utilizing the space to place the crankcase 28 of the engine E. As a result, a relatively wide space can be provided between the cylinder block 29 and the front wheel Wf, allowing accessories such as the air cleaner 7 and the oil cooler 8 to be installed with ease, and shortening the wheelbase [0043] In FIGS. 14 through 16, the air cleaner 7 of the engine E is mounted on the left and right front joint plates 25, 25 of the auxiliary frame Fs by bolts 39, and is disposed forwardly and upwardly of the cylinder block 29 that is inclined forwardly substantially horizontally. The air cleaner 7 has a case, i.e., a cleaner case 75, comprising a front case half 75a and a rear case half 75b joined to the front case half 75a by a plurality of screws 46. An element holder 78 holding a cleaner element 77 is sandwiched between the case halves 75a, 75b. Each of the case halves 75a, 75b is made of synthetic resin. The front case half 75a is shallow in the fore-and-aft direction of the motorcycle, and the rear case half 75b is deep in the fore-and-aft direction of the motorcycle. A pair of left and right brackets 79, 79 is integrally formed with an upper surface of the rear case half 75b and coupled by the bolts 3 9 to the left and right front joint plates 25, 25 of the auxiliary frame Fs. [0044] The element holder 7 8 is also made of synthetic resin, and comprises a partition wall 78a having a seal projection 80 on its outer circumference and a vertically elongate rectangular holder frame 78b integrally formed with a central portion of the partition wall 78a. The cleaner element 77, which is made of paper, is inserted in an inner peripheral wall of the holder frame 78b. A frame trap 81 comprising a perforated plate covering one side of the cleaner element 77 is thermally crimped on an end face of the holder frame 78b which faces the rear case half 75b. [0045] The seal projection 80 on the outer circumference of the partition wall 78a is fitted in seal grooves 82, 83 defined in mating surfaces of the front and rear case halves 75a, 75b. A pair of left and right air inlet pipes 84 which projects rearwardly is integrally formed with the upper end of the partition wall 78a. A pair of left and right upwardly bulging portions 85, 85 is formed on the upper end of the front case half 75a. The left and right air inlet pipes 84 project rearwardly outwardly through the bulging portions 85, 85 for introducing air into the front case half 75a. [0046] A connecting tube 86 has an end connected to a side wall of the rear case half 75b and an opposite end connected to the carburetor 6 of the engine E. Therefore, the interior of the front case half 75a serves as an uncleaned air chamber 87, and the interior of the rear case half 75b as a cleaned air chamber 88. [0047] The holder frame 78b of the element holder 78 projects from front and rear side surfaces of the partition wall 78a. Left and right side walls of the holder frame 78b projecting into the uncleaned air chamber 87 and left and right side walls of the front case half 75a define vertically extending groove-like air guide passages 89, 89. The air inlet pipes 84 are connected to the upper ends of the air guide passages 89, 89. The air guide passages 89, 89 communicate with the cleaner element 77 beyond the side wall of the holder frame 7 8b. [0048] The front case half 75a and the partition wall 78a have guide walls 90, 90 for directing an air flow that has passed through the air inlet pipes 84 downwardly of the air guide passages 89, 89. Each of the guide walls 90, 90 comprises a convex wall 90a formed on the front case half 75a and a pair of convex walls 90b, 90b formed on the partition wall 78a in laterally sandwiching the convex wall 90a therebetween. [0049] While the engine E is in operation, ambient air is introduced from the left and right air inlet pipes 84 into the uncleaned air chamber 87 during an intake stroke of the engine E. At this time, the air that has passed through the air inlet pipes 84 is guided downwardly of the air guide passages 89, 89 by the guide walls 90, 90, and then flows from the entire air guide passages 89, 89 beyond the side wall of the holder frame 78b to the cleaner element 77. Therefore, even though the uncleaned air chamber 87 is flat in the fore-and-aft direction of the motorcycle, the introduced air can be distributed to the entire cleaner element 77 and can efficiently be cleaned. [0050] Since the left and right air guide passages 89, 89 are defined by the holder frame 78b projecting into the uncleaned air chamber 87 and left and right side walls of the front case half 75a, no special passage members for the air guide passages 89, 89 are required, and the structure is simplified. In addition, the uncleaned air chamber 87 can sufficiently be flattened, contributing to a reduction in the dimension of the entire air cleaner in the fore-and-aft direction of the motorcycle, and making it easy to lay out the air cleaner 7 in a small space between the front fork 1 and the main pipe 11. [0051] As the air inlet pipes 84, 84 connected to the upper ends of the left and right air guide passages 89, 89 are integrally formed with the partition wall 78a of the element holder 78, the number of parts of the air cleaner 7 can be reduced, and the structure thereof can be simplified. [0052] In FIGS. 2, 17, and 18, the oil cooler 8 is of the air-cooled type for cooling the lubricating oil of the engine E. The oil cooler 8 has an integral succession of cooling shells 91, 91 ••• each having a cooling fin 91a on its outer circumference, and is of a flat shape in the fore-and-aft direction of the motorcycle. The oil cooler 8 is mounted by bolts 47 on upper and lower brackets 93, 94 disposed respectively on the left and right side pipes 20, 20 with elastic support members 95 interposed therebetween. The oil cooler 8 is inclined rearwardly upwardly at a sharp gradient between the left and right side pipes 20, 20 with its upper end disposed between the cylinder head 4 0 coupled to the forwardly inclined cylinder block 2 9 and the carburetor 6 disposed above the cylinder head 40. The cross pipe 21 is disposed so as to cover the front side of the lower end of the oil cooler 8 [0053] Between the front wheel Wf and the auxiliary frame Fs, there is disposed a louver 92 supported on the left and right side pipes 20, 20 for guiding run air substantially perpendicularly to the front surface of the oil cooler 8. [0054] As the oil cooler 8 is inclined rearwardly at a sharp gradient with its upper end disposed between the cylinder head 40 coupled to the forwardly inclined cylinder block 29 and the carburetor 6 disposed above the cylinder head 40, the oil cooler 8 of large capacity can be installed effectively in a small space between the cylinder head 40 and the front wheel Wf for efficiently cooling the engine E and shortening the overall length of the motorcycle M. At the same time, the required height above ground of the oil cooler 8 can be achieved. [0055] Though the oil cooler 8 is inclined rearwardly, the oil cooler 8 can effectively be cooled as run air is guided substantially perpendicularly to the front surface of the oil cooler 8 by the louver 92. [0056] The oil cooler 8 is protected from interference with protrusions on the road by the cross pipe 21 which covers the lower end of the oil cooler 8. The cross pipe 21 interconnects the left and right side pipes 20, 20 and also the left and right floor support pipes 22, 22. Therefore, the auxiliary frame Fs can effectively be reinforced. [0057] As the oil cooler 8 is mounted, together with the air cleaner 7, on the auxiliary frame Fs that is removably attached to the main frame Fm, the oil cooler 8 and the air cleaner 7 can be installed on the auxiliary frame Fs easily without being obstructed by adjacent members such as the main frame Fm and the engine E if they are installed before the auxiliary frame Fs is coupled to the main frame Fm. The oil cooler 8 and the air cleaner 7 can be serviced for maintenance easily while the auxiliary frame Fs is being disconnected from the main frame Fm. Accordingly, the assembly and maintenance of the oil cooler 8 and the air cleaner 7 can favorably be performed. [0058] The present invention is not limited to the above embodiment, but various design changes may be made therein without departing from the gist of the invention. For example, if the engine E is of the water-cooled type, then the oil cooler 8 may be replaced with a radiator. [Description of Reference Characters] [0060] C-•-vehicle body cover F---vehicle body frame M---motorcycle 27-•-crankshaft 28•- -crankcase 2 8a, 28b---bulging end 52 - -•floor member 53 - - - floor surface 53m---main floor surface 53s•-•auxiliary floor surface 55 - --opening 56 - --step plate 57---elastic support member 60 - - - floor mat WE CLAIM: 1. A floor structure for a motorcycle, characterized in that a floor member (52) having floor surface (53) for placing a foot of the rider is joined to a vehicle body cover ( C ) fixedly supported on a vehicle body frame (F) on which an engine (E) is supported, the floor member (52) has an opening (55) which is open in said floor surface (53), a step plate (56) supported on the vehicle body frame (F) by an elastic support member (57) is disposed in said opening (55), with a gap (g) provided between the step plate (56) and an inner peripheral edge of said opening (55) for allowing said elastic support member (57) to be elastically deformed, and a flexible floor mat (60) is laid from said floor surface (53) to said step plate (56) in covering relation to upper surfaces of said floor surface (53) and said step plate (56) and said gap (g). 2. A floor structure for a motorcycle as claimed in claim 1, wherein that an auxiliary floor surface (53s) of said floor surface (53), which extends rearwardly from a rear end of said opening (55), is inclined rearwardly upwardly, and bulging ends (28a, 28b) bulging leftwardly and rightwardly from a crankcase (28) of said engine are disposed directly below said auxiliary floor surface (53s). 3. A floor structure for a motorcycle as claimed in claim 2, wherein that said bulging end (28a) houses therein a torque converter (42) mounted on an end of a crankshaft (27) of said engine (E). 4. A floor structure for a motorcycle as claimed in claim 2, wherein that said bulging end (28b) houses therein a generator (44) actuatable by an end of a crankshaft (27) of said engine (E). 5. A floor structure for a motorcycle substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

1305-DEL-2004-Abstract-(02-06-2010).pdf

1305-del-2004-abstract.pdf

1305-DEL-2004-Claims-(02-06-2010).pdf

1305-del-2004-claims.pdf

1305-DEL-2004-Correspondence-Others-(02-06-2010).pdf

1305-del-2004-correspondence-others.pdf

1305-DEL-2004-Description (Complete)-(02-06-2010).pdf

1305-del-2004-description (complete).pdf

1305-del-2004-drawings.pdf

1305-DEL-2004-Form-1-(02-06-2010).pdf

1305-del-2004-form-1.pdf

1305-del-2004-form-19.pdf

1305-del-2004-form-2.pdf

1305-DEL-2004-Form-3-(02-06-2010).pdf

1305-del-2004-form-3.pdf

1305-del-2004-form-5.pdf

1305-DEL-2004-GPA-(02-06-2010).pdf

1305-DEL-2004-Petition-137-(02-06-2010).pdf

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