Title of Invention

TWO-WHEELED MOTOR VEHICLE

Abstract

It is a task of the present invention to provide a two-wheeled motor vehicle having a frame structure which is capable of reducing the size of the motor vehicle without involving an increase in the width of the motor vehicle,/ [Solving Means] The frame structure of a two-wheeled motor vehicle 10 includes a main frame 25 having two left and right frames 24L, 24R, a power unit 15 swingably mounted on a rear end of the main frame 25, and a rear cushion unit 31 disposed between a rear portion of the power unit 15 and the main frame 25. One of the left and right frames 24L, 24R has an overlapping portion 81 overlapping the power unit 15 as viewed from above the motor vehicle, and the overlapping portion 81 includes a clearance region 82 clearing the power unit 15 in an upward direction of the motor vehicle./ [Selected Drawing] Fig. 2

Full Text

[Name of Document] Specification [Title of the Invention] Two-Wheeled Motor Vehicle [Technical Field] [0001] The present invention relates to an improvement in a two-wheeled motor vehicle including a power unit swingably mounted on a main frame. [Baclcground Art] [0002] There are known two-wheeled motor vehicles including a power unit swingably mounted on a main frame and having an engine and a transmission that are integrally combined with each other (see, for example, Patent Document 1). [Patent Document 1] International Laid-Open Publication No. 2004/071858 (Fig. 4) [0003] Fig. 4 of Patent Document 1 shows a motor vehicle frame assembly including a head pipe 20 (the reference character cited from the publication, as with other reference characters) from which a down tube 21 extends, a left side tube 22 and a right side tube 23, each of a circular cross section, extending from the down tube 21 on left and right sides of a vehicle body, and a cross pipe 25 extending between the rear end portions of the left side tube 22 and the right side tube 23. [0004] A rectangular pipe frame 24 having a rectangular cross section extends obliquely upwardly from the rear end portion of the left side tube 22. The rectangular pipe frame 24 doubles as a left seat pipe. The right side tube 23 which has a circular cross section projects outwardly and extends obliquely upwardly from the rear end portion of the right side tube 23. The right side tube 23 is coupled to a right seat pipe 26 which extends from the rectangular pipe frame 24. A power unit including an integral combination of an engine 11 and a transmission is swingably disposed between the rectangular pipe frame 24 and the right side tube 23. [0005] According to the art of Patent Document 1, the right side tube 23 projects outwardly and extends to avoid interference of the power unit with the right side tube 23. However, since the right side tube 23 projects outwardly and extends, the width of the motor vehicle increases, making it difficult to reduce the size of the motor vehicle. In particular, there is a demand for improving the right side tube 23 because it is in a position for affecting the bank angle of the motor vehicle. [Disclosure of the Invention] [Problem to be Solved by the Invention] [0006] It is a task of the present invention to provide a two-wheeled motor vehicle having a frame structure which is capable of reducing the size of the motor vehicle without involving an increase in the width of the motor vehicle. [Means for Solving the Problem] [0007] According to an invention recited in claim 1, there is provided a two-wheeled motor vehicle including a main frame having two left and right frames, a power unit swingably mounted on the main frame, and a rear cushion unit disposed between a rear portion of the power unit and the main frame, wherein one of the left and right frames has an overlapping portion overlapping the power unit as viewed from above the motor vehicle, and the overlapping portion includes a clearance region clearing the power unit in an upward direction of the motor vehicle. [0008] According to an invention recited in claim 2, the left and right frames include a round pipe frame and a rectangular pipe frame, the rear cushion unit being coupled to the rectangular pipe frame, and the clearance region being provided on the round pipe frame, [0009] According to an invention recited in claim 3, the power unit includes an external air inlet member for introducing external air to cool the power unit, the external air inlet member being disposed in overlapping relation to the clearance region as viewed from above the motor vehicle. [0010] According to an invention recited in claim 4, the left and right frames extend obliquely upwardly in a rearward direction of the motor vehicle, and overlap each other near a seat support as viewed laterally of the motor vehicle. [Effect of the Invention] [0011] According to the invention recited in claim 1, there is an overlapping portion between one of the left and right frames and the power unit as viewed from above the motor vehicle, and the overlapping portion includes a clearance region clearing the power unit in an upward direction of the motor vehicle. [0012] As one of the frames has the clearance region, the power unit is prevented from interfering with the clearance region even though the overlapping portion is present between the frame and the power unit. Since the clearance region is provided in the upward direction of the motor vehicle, the width of the motor vehicle is not increased. As the width of the motor vehicle is not increased, the size of the motor vehicle is reduced. [0013] According to the invention recited in claim 2, the clearance region is provided on the round pipe frame, and the frame can be bent more easily than the rectangular pipe frame. Forces from the road are transmitted through the rear cushion and borne by the rectangular pipe frame which is of higher rigidity, and the round pipe frame can be reduced in weight. Furthermore, as the round pipe frame can be bent easily, the cost of machining the frame is reduced. [0014] According to the invention recited in claim 3, the power unit includes an external air inlet member which is disposed in overlapping relation to the clearance region. Consequently, the width of the motor vehicle is not increased, and the size of the motor vehicle is reduced. [0015] According to the invention recited in claim 4, the left and right frames extend obliquely upwardly in a rearward direction of the motor vehicle, and overlap each other near a seat support. Therefore, a seat can be installed in position with ease. There is no need to add new parts for installing the seat on the left and right frames. [Best Mode for Carrying out the Invention] [0016] A best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the drawings, the terms "front", "rear", "left", "right", "upper", and "lower" represent directions as viewed from the rider of the motor vehicle. The drawings should be viewed in the direction in which the reference characters look normally. Fig. 1 is a left side elevational view of a two-wheeled motor vehicle according to the present invention. The two-wheeled motor vehicle 10, which is in the form of a scooter-type motor vehicle, includes a power unit 15 swingably mounted on a rear portion of a vehicle frame 11 by a link mechanism 14 including a pivot shaft 12. [0017] The power unit 15 includes an engine 16 as a driving force source and a transmission case 17 disposed behind the engine 16. The transmission case 17 houses therein a belt-type continuously variable transmission 18 for transmitting the driving force of the engine 16 to a rear wheel 19. The transmission case 17 is swingably mounted on a rear end portion of the vehicle frame 11 for transmitting driving force of the engine 16 to the rear wheel 19. [0018] The vehicle frame 11 includes a head pipe 21, a down frame 22 connected to and extending obliquely downwardly from the head pipe 21 and then substantially horizontally rearwardly, a cross member 23 mounted on a rear end portion of the down frame 22, and left and right frames 24L, 24R rising obliquely rearwardly from the cross member 23. The down frame 22, the cross member 23, and the left and right frames 24L, 24R jointly make up a main frame 25. [0019] The two-wheeled motor vehicle 10 has a front fork 26 steerably mounted on the head pipe 21, a front wheel 2 8 mounted on the lower end of the front fork 26, and a steering handle 2 9 mounted on the upper end of the front fork 26. A read wheel 19 is mounted on the rear end of the power unit 15 which doubles as a rear swing arm. A rear cushion unit 31 extends between the rear end of the power unit 15 and the frame 24L. [0020] The link mechanism 14 which is interposed between the power unit 15 and the cross member 23 includes a support shaft 32 disposed near the cross member 23, a link member 33 extending rearwardly from the support shaft 32, and the pivot shaft 12 which is mounted on the rear end of the link member 33. [0021] The transmission case 17 has an opening 35 defined in a front portion 17a thereof, and a duct 36 as an external air inlet pipe is connected to the opening 35. External air is introduced through the duct 3 6 connected to the opening 3 5 in the transmission case 17 into the transmission case 17 for thereby cooling the belt-type continuously variable transmission 18. [0022] The engine 16, which is located as a front portion of the power unit 15, has a cylinder block 3 7 to which an intake device 3 8 and an exhaust device 3 9 are connected. The intake device 3 8 includes an air cleaner 41 and a fuel supply unit 42 connected to the air cleaner 41. The exhaust device 3 9 includes an exhaust pipe 43 connected to and extending rearwardly from the engine 16, and a muffler 44 connected to and extending rearwardly from the exhaust pipe 43. [0023] An upwardly open storage box 45 is mounted on the frames 24L, 24R. A seat 46 for the rider to be seated thereon is disposed above the storage box 45. A fuel tank 47 is disposed behind the storage box 45. The seat 46 is openably and closably mounted on the storage box 4 5 and fuel tank 47. [0024] The reference numeral 51 denotes a passenger step frame, 52 a step floor support frame supporting a step floor 58, 53 a grab rail, 54 a front brake unit, 55 a front fender, 56 a cowl member, and 57 a rear fender. [0025] The two-wheeled motor vehicle 10 is thus a scooter-type motor vehicle including the vehicle frame 11, the transmission case 17 swingably mounted on the vehicle frame 11 and housing the belt-type continuously variable transmission 18 for transmitting driving force of the engine 16 to the rear wheel, the seat 46 mounted on an upper portion of the vehicle frame 11 for the rider to be seated thereon, the storage box 45 disposed below the seat 46 for storing objects therein, and the duct 36 disposed between the storage box 45 and the transmission case 17 for introducing external air into the transmission case 17. [0026] Fig. 2 is a cross-sectional view of an engine cooling mechanism disposed around the engine according to the present invention. Fig. 3 is a perspective view of the engine cooling mechanism disposed around the engine according to the present invention. The engine cooling mechanism will be described below with reference to Figs. 2 and 3. The engine cooling mechanism 60 includes a case 61 disposed around the cylinder block 37 of the engine 16, a fan 62 disposed laterally of the case 61 for supplying external air to the case 61, and an external air inlet member 64 disposed laterally of the fan 62 and having an external air inlet port 63. [0027] The case 61 has a front end engaging a front portion 16f of the engine 16 and a rear end fastened to the transmission case 17 by a bolt 65. The fan 62 is connected to a crankshaft 66 of the engine 16. When the engine 16 rotates its crankshaft S6, the fan 62 rotates to introduce external air into the case 61 from the external air inlet port 63. [0028] The external air inlet member 64 which has the external air inlet port 63 is disposed on the right side of the motor vehicle. The case 61 has a discharge port 67 defined in a lower portion thereof for discharging waste heat air. External air is introduced from the external air inlet port 63 and flows between the case 61 and the engine 16, and waste heat air heated by the engine 16 is discharged from the discharge port 67, thereby cooling the engine 16. The reference numeral 68 denotes a bolt which fastens the external air inlet member 64 to the case 61. [0029] Fig. 4 is a left side elevational view of a frame structure of the two-wheeled motor vehicle according to the present invention, and Fig. 5 is a view as viewed along the arrow 5 in Fig. 4. The frame structure will be described below with reference to Figs. 4 and 5. The vehicle frame 11 includes the single down frame 22 connected to and extending obliquely downwardly from the head pipe 21 and then substantially horizontally rearwardly, the cross member 23 mounted on the rear end portion of the down frame 22 and extending laterally in a substantially horizontal direction, and the left and right frames 24L, 24R rising obliquely rearwardly from side surfaces 23s, 23s on the opposite ends of the cross member 23. [0030] The reference numeral 71 denotes a bracket supporting the cowl member, 72 a stiffening member for increasing the coupling strength between the head pipe 21 and the down frame 22, 73 a cross frame extending between the left and right frames 24L, 24R and supporting the storage box (45 in Fig. 1), 74L, 74R pivot plates supporting the power unit 15, 75 a seat cross frame, 76 a rear cross frame, 77 a cushion bracket to which the rear cushion.unit 31 is attached, and 78 a bracket to which the rear fender 57 is attached. [0031] Referring back to Fig. 2, as viewed from above the motor vehicle, the right frame 24R of right and left flames 24R and 24L includes an overlapping portion 81 which overlaps the power unit 15, and the overlapping portion 81 includes a clearance region 82 clearing the power unit 15 in an upward direction of the motor vehicle As shown in Fig. 4, the clearance region 82 is a region of the overlapping portion 81 where the right frame 24R is positioned higher than the left frame 24L as viewed laterally of the vehicle frame 11. [0032] The left and right frames 24L, 24R include a round pipe frame 83 and a rectangular pipe frame 84, the clearance region 82 being provided on the round pipe frame 83 as the right frame 24R. The rear cushion unit 31 is coupled to the rectangular pipe frame 84. [0033] Since the clearance region 82 is provided on the round pipe frame 83, the round pipe frame 83 including the clearance region 82 can be machined more easily than the rectangular pipe frame 84. Forces from the road are transmitted through the rear cushion 31 and borne by the rectangular pipe frame 84 which is of higher rigidity, and the round pipe frame 83 can be reduced in weight. Furthermore, as the round pipe frame 83 can be bent easily, the cost of machining the vehicle frame 11 is reduced. [0034] As shown in detail in Fig. 2, the power unit 15 includes the external air inlet member 64 for introducing external air to cool the power unit 15. The external air inlet member 64 is disposed in overlapping relation to the clearance region 82 as viewed from above the motor vehicle. [0035] Heretofore, since the main frame 25 has had a portion extending so as to project outwardly to avoid interference with the external air inlet member 64 of the power unit 15, the width of the motor vehicle has increased. According to the present invention, since the external air inlet member 64 is disposed in overlapping relation to the clearance region 82, the width of the motor vehicle is prevented from increasing, and the motor vehicle can be reduced in size. [0036] Referring back to Fig. 1, the left and right frames 24L, 24R extend obliquely upwardly in the rearward direction of the motor vehicle, and overlap each other near the seat support 85 including the seat cross frame 75 and the rear cross frame 76 as viewed laterally of the motor vehicle. [0037] Since the left and right frames 24L, 24R extend obliquely upwardly in the rearward direction of the motor vehicle, and overlap each other near the seat support 85 which supports the seat 46, there is no need to add new parts for installing the seat 46 in position with ease. [0038] Fig. 6 is an enlarged view of an area 6 shown in Fig. 4. A left pivot plate 74L formed in the shape of a plate and having a pivot hole 87 defined therein is joined by welding to the left end of the cross member 23. The step floor support frame 52, a passenger step frame 91, and a stand (the reference character 52 in Fig. 1) bracket 92 are joined by welding to an outer surface of the left pivot plate 74L. The step floor support frame 52 is a member for supporting the step floor (the reference numeral 58 in Fig. 1) . The support shaft (the reference numeral 32 in Fig. 1) is mounted in the pivot hole 87. [0039] Fig. 7 is a cross-sectional view taken along line 7 - 7 of Fig. 5. A right pivot plate 74R formed in the shape of a plate and having a pivot hole 87 defined therein is joined by welding to the right end of the cross member 23. The step floor support frame 52 and the passenger step frame 91 are joined by welding to an outer surface of the right pivot plate 74R. The support shaft (the reference numeral 32 in Fig. 1) is mounted in the pivot hole 87. [0040] Referring back to Fig. 5, the frame structure of the scooter-type motor vehicle 20 includes the main frame 25, pivots 86 mounted on the main frame 25 and by which the power unit (the reference numeral 15 in Fig. 1) is swingably coupled, and step floor support frames 52, 52 mounted on the pivot plates 74L, 74R of the pivot 86 and supporting the step floor (the reference numeral 58 in Fig. 1). As described above, the cross member 23 is directly welded to the pivot 86. The step floor support frames 91, 91 are directly welded to the pivots 86. [0041] In the present embodiment, the vehicle frame 11 is made of carbon steel. However, the vehicle frame 11 may be made of aluminum alloy. The welding is fillet welding for joining workpieces with a filler metal that is melted and added to the boundary between the workpieces. Though the welding is performed by an arc welding process, any of other welding processes such as a gas welding process, a laser beam welding process may be employed. [0042] Operation of the frame structure of the two-wheeled motor vehicle described above will be described below. Referring back to Fig. 2, since the clearance region 82 is provided on the right frame 24R as one frame, even though the right frame 24R and the power unit 15 overlap each other in the overlapping portion 81, the power unit 15 is prevented from interfering with the clearance region 82. As the clearance region 82 extends in the upward direction of the motor vehicle, the width of the motor vehicle is not increased. As the width of the motor vehicle is not increased, the size of the motor vehicle can be reduced. [0043] Fig. 8 is a view illustrative of the positional relationship between the main frame and the power unit. The overlapping portion 81 includes the clearance region 82 which clears the power unit 15 in the upward direction of the motor vehicle. As the main frame 25 has the clearance region 82, even when the power unit 15 swings greatly upwardly and downwardly, the power unit 15 is prevented from interfering with the main frame 25, so that the rear wheel 19 can have a large cushioning stroke When the power unit 15 swings, there is no danger for the external air inlet member 64 to interfere with the main frame 25. [0044] In the drawings, the air cleaner 41 partly overlaps the frames 24L, 24R. However, inasmuch as the air cleaner 41 is disposed between the left frame 24L and the right frame 24R, the air cleaner 41 and the frames 24L, 24R do not interfere with each other. [0045] Referring back to Fig. 5, the step floor support frames 52, 52 which support the step floor (the reference numeral 58 in Fig. 1) are directly welded to the pivots 86, 86 including the pivot plates 74L, 74R without the intervention of other parts, so that the vehicle frame 11 can be simplified in structure. In addition, the number of parts on the vehicle frame 11 can be reduced. By simplifying the structure of the vehicle frame 11, the number of steps of welding the vehicle frame 11 can be reduced. Furthermore, the weight of the vehicle frame 11 can be reduced. [0046] Referring to Figs. 1 and 2, as the round pipe frame 83 which can be machined more easily than the rectangular pipe frame 84 is disposed on one side, i.e., the side where the external air inlet member 64 is disposed, it is easy to hold the round pipe frame 83 out of interference with the power unit 15. As the rectangular pipe frame 84 is disposed on the other side, the left frame 24L to which the rear cushion unit 31 is connected is sufficiently strong. [0047] While the frame structure according to the present invention is applied to the two-wheeled motor vehicle in the embodiment, it may be applied to a saddle-type motor vehicle. In Claim 1, the left and right frames may include round pipe frame only or rectangular pipe frames only. [Industrial Applicability] [0048] The present invention is suitable for scooter-type two-wheeled motor vehicles. [Brief Description of the Drawings] [0049] [Fig. 1] Fig. 1 is a left side elevational view of a two-wheeled motor vehicle according to the present invention. [Fig. 2] Fig. 2 is a cross-sectional view of an engine cooling mechanism disposed around an engine according to the present invention. [Fig. 3] Fig. 3 is a perspective view of the engine cooling mechanism disposed around the engine according to the present invention. [Fig. 4] Fig. 4 is a left side elevational view of a frame structure of the two-wheeled motor vehicle according to the present invention. [Fig. 5] Fig. 5 is a view as viewed along the arrow 5 in Fig 4. [Fig. 6] Fig. 6 is an enlarged view of an area 6 shown in Fig. 4. [Fig. 7] Fig. 7 is a cross-sectional view taken along line 7 - 7 of Fig. 5. [Fig. 8] Fig. 8 is a view illustrative of the positional relationship between a main frame and a power unit. [Description of Reference Symbols] [0050] 10••-two-wheeled motor vehicle, 15-•-power unit, 24L'•-left frame, 24R-•-right frame, 25-•-main frame, 31-•-rear cushion unit, 64••-external air inlet member, 81••-overlapping portion, 82-•-clearance region, 83---round pipe frame, 84-•-rectangular pipe frame. [Name of Document] Drawings [Fig. 1] lA: Up IB: Down IC: Front ID: Rear [Fig. 2] 2A: Right 2B: Left 2C: Front 2D: Rear [Fig. 3] 3A: Up 3B: Down 3C: Rear 3D: Front 3E: Right 3F: Left [Fig. 4] 4A: Up 4B: Down 4C: Front 4D: Rear [Fig. 5] 5A: Left 5B: Right 5C: Front 5D: Rear [Fig. 6] 6A: Up 6B: Down 6C: Front 6D: Rear [Fig. 7] 7A: Up 7B: Down 7C: Front 7D: Rear [Name of Document] Claims [Claim 1] A two-wheeled motor vehicle including a main frame having two left and right frames, a power unit swingably mounted on the main frame, and a rear cushion unit disposed between a rear portion of the power unit and the main frame, wherein one of said left and right frames has an overlapping portion overlapping said power unit as viewed from above the motor vehicle, and the overlapping portion includes a clearance region clearing said power unit in an upward direction of the motor vehicle. [Claim 2] The two-wheeled motor vehicle according to claim 1, wherein said left and right frames comprise a round pipe frame and a rectangular pipe frame, said rear cushion unit being coupled to said rectangular pipe frame, and said clearance region being provided on said round pipe frame. [Claim 3] The two-wheeled motor vehicle according to claim 1 or 2, wherein said power unit includes an external air inlet member for introducing external air to cool said power unit, said external air inlet member being disposed in overlapping relation to said clearance region as viewed from above the motor vehicle. [Claim 4] The two-wheeled motor vehicle according to claim 1 or 3; wherein said left and right frames extend obliquely upwardly in a rearward direction of the motor vehicle, and overlap each other near a seat support as viewed

Documents:

2632-CHE-2007 AMENDED CLAIMS 21-12-2012.pdf

2632-CHE-2007 AMENDED PAGES OF SPECIFICATION 21-12-2012.pdf

2632-CHE-2007 CORRESPONDENCE OTHERS 17-01-2012.pdf

2632-CHE-2007 EXAMINATION REPORT REPLY RECEIVED 21-12-2012.pdf

2632-CHE-2007 FORM-3 21-12-2012.pdf

2632-CHE-2007 OTHER PATENT DOCUMENT 21-12-2012.pdf

2632-che-2007-abstract.pdf

2632-che-2007-claims.pdf

2632-che-2007-correspondnece-others.pdf

2632-che-2007-description(complete).pdf

2632-che-2007-drawings.pdf

2632-che-2007-form 1.pdf

2632-che-2007-form 18.pdf

2632-che-2007-form 26.pdf

2632-che-2007-form 3.pdf

2632-che-2007-form 5.pdf