Title of Invention

"A VEHICULAR FUEL PIPE STRUCTURE OF A VEHICLE"

Abstract

A vehicular fuel pipe structure of a vehicle wherein said fuel pipe comprises at least an internal combustion engine-side swing-direction extending portion (125), a part of said extending portion (125) being supported by a pipe support portion (97), (98) provided in the body portion of the internal combustion engine, said fuel pipe includes a vehicle body-side swing-direction extending portion (124) extending from a vehicle body-side hose support portion (93) provided in the vehicle body and a U-shaped extending portion (126) extending along an outer surface of said cylinder head (48), said U-shaped extending portion (126) connecting said extending portions (124), (125) with each other, and said internal combustion engine-side swing-direction extending portion (125) and said vehicle body-side swing-direction extending portion (124) are arranged substantially side by side in the transverse direction of the vehicle body.

Full Text

The present invention relates to a vehicular fuel pipe structure. [Background Art] As a conventional vehicular fuel pipe structure, there is known a structure wherein a fuel pipe extends from a fuel tank disposed below a step floor up to an engine disposed at the back of the fuel tank (see, for example, Patent Document 11 - Fig. 2 in Patent Document 1 will be described below in terms of Fig. 9 attached hereto, to which reference numerals were newly assigned. Fig. 9 is a plan view showing a conventional vehicular fuel pipe structure. In the same figure, an engine 202 and a fuel tank 203 disposed in front of the engine 202 are secured to a body frame 201, a fuel supply unit 204 is integrally secured to the fuel tank 203, a fuel injection valve (not shown) is secured to a cylinder portion 206 of the engine 202 by means of a fuel connector 207, and a fuel conduit 212 is connected to a fuel outlet pipe 208 mounted on top of the fuel supply unit 204 and also to a. connecting pipe (not shown) provided in the fuel connector 207. In the above technique, the fuel conduit 212 is extended long in the longitudinal direction of the vehicle in order to make small a deflection angle of the fuel conduit 212. However, since the fuel conduit 212 is long, a vertical vibration quantity of the fuel conduit 212 is large when the engine 202 swings in the vertical direction (in the obverse and reverse direction of the figure) relative to the body frame 201. For example, therefore, it is necessary that the step floor disposed above the fuel tank 203 be positioned high so as to avoid interference thereof with the fuel conduit 212 when the fuel tank vibrates upward. Further, it is required that a space for vibration of the fuel conduit 212 be provided around the fuel conduit 212, particularly in the vertical direction. With this space, the vehicle becomes larger in size. Particularly, in a small-sized vehicle, it is difficult to ensure such a space. Further, if the fuel conduit 212 is long, its weight also becomes larger and a large force acts on a mounting portion of the fuel conduit 212 upon vibration of the fuel conduit. To bear this force, it is necessary to increase the rigidity of the said mounting portion, which results in an increase in both size and weight. [Disclosure of the Invention] [Problems to be Solved by the Invention] It is an object of the present invention to provide a vehicular fuel pipe structure capable of decreasing the amount of vibration of a fuel pipe to attain a compact structure of the vehicle and diminishing a force acting on a fuel pipe mounting portion to attain the reduction of both size and weight. [Means for Solving the Problems] According to the invention defined in claim 1, a power unit having a body portion of an internal combustion engine comprising a cylinder and a cylinder head is secured to a vehicle body frame swingably with the cylinder head facing forward of the vehicle body. A fuel pump is connected to a fuel tank secured to the vehicle body frame, and a fuel injection valve is disposed in an intake passage formed in the body portion of the internal combustion engine. The fuel pump and the fuel injection valve are connected with each other through a fuel pipe. In such a vehicle, there is provided a vehicular fuel pipe structure characterized in that the fuel pipe includes at least an internal combustion engine-side swing-direction extending portion extending in the swing direction around the body portion of the internal combustion engine. A part of the internal combustion engine-side swing-direction extending portion is supported by a pipe support portion provided in the body portion of the internal combustion engine. When the power unit swings, the internal combustion engine-side swing-direction extending portion of the fuel pipe is moved in an axial direction thereof to suppress the amount of vibration in the swing direction of the internal combustion engine-side swing-direction extending portion. Further, a force acting on the pipe support portion is diminished by decreasing the amount of vibration of the internal combustion engine-side swing direction extending portion. The invention defined in claim 2 is characterized in that the fuel pipe includes a vehicle body-side swing-direction extending portion extending in the swing direction from a vehicle body-side hose support portion provided in the vehicle body and a U-shaped extending portion extending in U shape along an outer surface of the cylinder head. The U-shaped extending portion connects the vehicle body-side swing-direction extending portion and the internal combustion engine-side swing-direction extending portion with each other. The vehicle body-side swing-direction extending portion and the internal combustion engine-side swing-direction extending portion are connected with each other through the U-shaped extending portion. When the power unit swings, the internal combustion engine-side swing-direction extending portion is moved substantially in parallel with the vehicle body-side swing-direction extending portion to diminish a change in curvature of the U-shaped extending portion. The invention defined in claim 3 is characterized in that the fuel pipe is disposed in such a manner that the internal combustion engine-side swing-direction extending portion and the vehicle body-side swing-direction extending portion are arranged substantially side by side in the transverse direction of the vehicle body . The internal combustion engine- side swing-direction extending portion and the vehicle body-side swing-direction extending portion are disposed substantially in the transverse direction of the vehicle body to shorten the distance between the two in the longitudinal direction of the vehicle body. The invention defined in claim 4 is characterized in that the vehicle is provided in front of the body portion of the internal combustion engine with a step floor for a rider to step thereon. The fuel tank is disposed below the step floor and the fuel pump is disposed within the fuel tank and is secured to an upper wall of the fuel tank. The fuel pipe is formed of metal or resin and is disposed above the fuel pump and below the step floor. The U-shaped extending portion is formed of rubber. Since the fuel pipe positioned above the fuel pump and below the step floor is formed of metal or resin, vertical vibrations of the fuel pipe are suppressed to permit lowering of the step floor position. The invention defined in claim 5 is characterized in that the cylinder head includes a head cover on a front side of the vehicle body, and the pipe support portion is provided in each of the cylinder head and the head cover. The pipe support portion is provided in each of the cylinder head and the head cover, and when the head cover is removed for maintenance, the fuel pipe is supported by the pipe support portion provided on the cylinder head side . [Effects of the Invention] In the invention defined in claim 1, the fuel pipe includes the internal combustion engine- side swing-direction extending portion. Therefore the extending portion moves in a direction of its axis when the power unit swings, so that it is possible to suppress the amount of vibration in the swing direction of the internal combustion engine-side swing-direction extending portion. Thus, the amount of vibration of the entire fuel pipe can be made small and it is possible to diminish the space for vibration of the fuel pipe. Consequently, other parts can be disposed in proximity to the fuel pipe, thus making it possible to construct the vehicle compactly. Besides, since the amount of vibration of the internal combustion engine-side swing-direction extending portion is decreased, it is possible to diminish the load imposed on the pipe support portion and hence possible to attain the reduction in both size and weight of the pipe support portion. In the invention defined in claim 2, the fuel pipe includes the vehicle body-side swing-direction extending portion and the U-shaped extending portion. The vehicle body-side swing-direction extending portion and the internal combustion engine-side swing-direction extending portion are connected with each other through the U-shaped extending portion. Therefore, when the power unit swings, the internal combustion engine- side swing-direction extending portion moves substantially in parallel to the vehicle body-side swing-direction extending portion. Thus a change in curvature of the U-shaped extending portion can be made small. A change in bending rate of the fuel pipe in the present invention is small, for example, in comparison with the case where one end of a straight fuel pipe moves relative to the other end and the fuel pipe bends largely. In the invention defined in claim 3, since the fuel pipe is disposed in such a manner that its internal combustion engine-side swing-direction extending portion and vehicle body-side swing direction extending portion are arranged substantially side by side in the transverse direction of the vehicle body, the distance between the internal combustion engine-side swing-direction extending portion and the vehicle body-side swing-direction extending portion in the longitudinal direction of the vehicle body can be shortened and so can be the distance between the fuel tank and the body portion of the internal combustion engine. Consequently, it is possible to shorten the wheel base of the vehicle. In the invention defined in claim 4, since the fuel pipe positioned above the fuel pump and below the step floor is formed of metal or resin, it is possible to suppress vertical vibrations of the fuel pipe, the step floor can be made closer to the fuel tank, and it is possible to lower the step floor. In the invention defined in claim 5, since the pipe support portion is provided in each of the cylinder head and the head cover, the fuel pipe can be supported by the pipe support portion provided on the cylinder head side when the head cover is removed for maintenance. Consequently, the fuel pipe can be kept positioned near the mounting portion of the head cover and it is possible to improve the working efficiency at the time of mounting the fuel pipe to the pipe support portion in the head cover. [Best Mode for Carrying Out the Invention] The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. It is assumed that the drawings should be seen in the directions of reference numerals. The present invention relates to a vehicular fuel pipe structure of a vehicle wherein a power unit having a body portion of an internal combustion engine (56) comprising a cylinder (47) and a cylinder head (48) is secured to a vehicle body frame (11) swingably with said cylinder head (48) facing forward of the vehicle body, a fuel pump (61) is connected to a fuel tank (16) secured to said vehicle body frame (11), and a fuel injection valve (105) is disposed in an intake passage (48a) formed in the body portion of said internal combustion engine (56), said fuel pump (61) and said fuel injection valve (105) being connected with each other through a fuel pipe, characterized in that said fuel pipe comprises at least an internal combustion engine-side swing-direction extending portion extending in the swing-direction around the body portion of said internal combustion engine (56), a part of said internal combustion engine-side swing-direction extending portion (125) being supported by a pipe support portion (97), (98) provided in the body portion of the internal combustion engine, said fuel pipe includes a vehicle body-side swing-direction extending portion (124) extending in the swing direction from a vehicle body-side hose support portion (93) provided in the vehicle body and a U-shaped extending portion (126) extending in U shape along an outer surface of said cylinder head (48), said U-shaped extending portion (126) connecting said vehicle body-side swing-direction extending portion (124) and said internal combustion engine-side swing-direction extending portion (125) with each other, said internal combustion engine-side swing-direction extending portion (125) and said vehicle body-side swing-direction extending portion (124) are arranged substantially side by side in the transverse direction of the vehicle body. [Brief Description of the Drawings] [Fig. 1] Fig. 1 is a side view of a vehicle according to an embodiment of the present invention. [Fig. 2] Fig. 2 is a side view of a principal portion, showing a fuel pipe structure in the vehicle embodying the present invention. [Fig. 3] Fig. 3 is a plan view of a principal portion, showing the fuel pipe structure in the vehicle embodying the present invention. [Fig. 4] Fig. 4 is a view as seen in the direction of arrow in Fig. 3. [Fig. 5] Fig. 5 is an explanatory diagram showing a fuel pipe according to the present invention. [Fig. 6] Fig. 6 is an operation diagram showing operations of the fuel pipe structure according to the present invention. [Fig. 7] Fig. 7 is an operation diagram showing operations of a fuel pipe as a comparative example. [Fig. 8] Fig. 8 is a side view of a principal portion, showing a vehicle according to another embodiment of the present invention. [Fig. 9] Fig. 9 is a plan view showing a conventional vehicular fuel pipe structure. Fig. 1 is a side view of a vehicle embodying the present invention. In the vehicle, which is a two-wheeled motor vehicle indicated at 10, a body frame 11 is composed of a front frame 12 and a rear frame 14 which is connected to a rear portion of the front frame 12 with bolts 13 ... (the dots ... indicate a plural number and this is also true in the following) . A fuel tank 16 is secured to a lower portion of the front frame 12 . A power unit 17, which comprises an engine 18 and a power transfer mechanism 21 connected to the engine 18, is secured to the rear frame 14 substantially horizontally in the longitudinal direction of the vehicle and swingably through a link 22. A rear portion of the power unit 17 is connected to a rear portion of the rear frame 14 through a rear cushion unit 23 . The numeral 31 denotes a head pipe secured to the front pipe 12, numeral 32 denotes a steering shaft supported rotatably by the head pipe 31, numeral 33 denotes a front fork secured to a lower end of the steering shaft 32, numeral 34 denotes a front wheel secured to a lower end of the front fork 33, numeral 36 denotes a bar handle secured to an upper end of the steering shaft 32, numeral 37 denotes a front cover which covers an upper portion of the front frame 12, numeral 38 denotes a front fender which covers an upper portion of the front wheel 34, numeral 41 denotes a step floor disposed above the fuel tank 16, numeral 42 denotes a receptacle box mounted on top of the rear frame 14, numeral 43 denotes a seat mounted over the receptacle box 42 so that it can be opened and closed, and numeral 44 denotes a body cover which covers the vehicle body portion located under the seat 43 . Further, numeral 45 denotes a rear wheel secured to the rear portion of the power unit 17, numeral 46 denotes a rear fender which covers an upper portion of the rear wheel 45, numeral 47 denotes a cylinder in which a piston (not shown) is received movably, numeral 48 denotes a cylinder head secured to a front portion of the cylinder 47, numeral 51 denotes a head cover which covers an end opening of the cylinder head 48, numeral 52 denotes an intake device extending backward from an upper portion of the cylinder head 48, numeral 53 denotes an exhaust device extending backward from a lower portion of the cylinder head 48, and numeral 54 denotes a stand. The cylinder 47 and the cylinder head 48 (including the head cover 51) are members which constitute a body portion 56 of an internal combustion engine. Fig. 2 is a side view of a principal portion, showing a fuel pipe structure in the vehicle embodying the present invention. As shown in the same figure, inside the fuel tank 16, a fuel pump 61 is secured to an upper wall 16a of the fuel tank 16. A fuel discharge port 61a is formed on top of the fuel pump 61. One end of a fuel pipe 62 is connected to the fuel discharge port 61a, and an opposite end of the fuel pipe 62 is connected to the cylinder head 48 side of the engine 18. The fuel pipe 62 extends partially between the fuel tank 16 and the step floor 41 and partially between the fuel tank 16 and the head cover 51. Numeral 71 denotes a cap for closing a fuel supply port of the fuel tank 16 and numeral 72 denotes a spark plug. Fig. 3 is a plan view of a principal portion, showing the fuel pipe structure in the vehicle embodying the present invention. The fuel pipe 62 comprises a tank-side mounting member 81 connected to the fuel discharge port 61a, a first hose 82 made of resin and connected to an extreme end of the tank-side mounting member 81, a metallic tube member 83 connected to an extreme end of the first hose 82, a second hose 84 made of rubber and connected to an extreme end of the tube member 83, and an engine- side mounting member 86 connected to an extreme end of the second hose 84 . The tube member 83 comprises a tube 88 and a plate piece 91 integrally secured to the tube 88. The plate piece 91 is secured with a bolt 92 to a vehicle body-side mounting member 93 which serves as a vehicle body- side hose support portion. Numeral 95 denotes a bolt for mounting the vehicle body- side mounting member 93 to the front frame 12 (see Fig. 1) . The second hose 84 is supported intermediately by a first support member 97 and a second support member 98 as pipe support portions mounted on the engine 18 side. The first support member 97 is mounted with a bolt 102 to a first mounting portion 101 provided in the head cover 51, while the second support member 98 is mounted with a bolt 104 to a second mounting portion 103 provided in the cylinder head 48.The engine-side mounting member 86 is for connecting the second hose 84 to the cylinder head 48 and for fixing a fuel injection valve 105 to the cylinder head 48. The fuel injection, valve 105 injects fuel into an intake passage 48a and a combustion chamber formed in the cylinder head 48. The engine-side mounting member 86 is secured to the cylinder head 48 with a pair of bolts 106. Numerals 111 . . . and 112 . . . denote bolts and nuts for mounting the fuel pump 61 to the fuel tank 16. Numeral 113 denotes a conductor for supplying an electric current to the fuel pump 61, and numeral 114 ... denote bolts for mounting the head cover 51 to the cylinder head 48. Fig. 4 is a view as seen in the direction of arrow 4 in Fig. 3. The second hose 84 (a cross-hatched portion for facilitating the understanding of its shape) is a generally C-like extending portion when seen in the arrowed direction. The second hose 84 comprises a flexible portion 121 extending from the first support member 97 to the tube member 83 side and adapted to deflect with swing motion of the power unit 17 (see Fig. 1) and a fixed portion 122 extending from the first support member 97 to the engine -side mounting member 86 and fixed to the engine 18 . The flexible portion 121 comprises a vehicle body-side extending portion 124 as a vehicle body-side swing-direction extending portion located near the connection with the tube member 83 and extending in a substantially vertical direction (i.e., in the swing direction of the cylinder head 48 and the head cover 51 in the power unit 17), a head cover-side extending portion 125 as an internal combustion engine-side swing-direction extending portion located near the support portion in the first support member 97 and extending in a substantially vertical direction, and a U-shaped extending portion 126 connected integrally to each of the vehicle body- side extending portion 124 and the head cover- side extending portion 125. The vehicle body-side extending portion 124 and the head cover-side extending portion 125 are located in a substantially transverse direction of the vehicle. Thus, in Figs. 2 and 4, the second hose 84 is disposed around the cylinder head 48 and the head cover 51 and between the body portion 56 of the internal combustion engine and the fuel tank 16. Accordingly, it is possible to effectively utilize the space around the cylinder head 48 and the head cover 51 and the space between the body portion 56 of the internal combustion engine (see Fig. 1) and the fuel tank 16. Consequently, it is possible to construct the vehicle 10 (see Fig. 1) compactly and reduce the size thereof. Fig. 5 is an explanatory diagram showing the fuel pipe according to the present invention. The tank-side mounting member 81 of the fuel pipe 62 is provided at one end thereof with a fitting portion 81a to be fitted in the fuel discharge port 61a (see Fig. 3) to ensure sealing performance. The connecting portion 81a has an ant i-dis lodgment mechanism. The tank-side mounting member 81 is provided at an opposite end thereof with a connecting portion 81b. The connecting portion 81b has plural grooves formed in an outer periphery thereof for fitting therein of a sealing member for connection to the first hose 82. The tube member 83 includes connecting portions 83a and 83b. The connecting portion 83a has plural grooves formed in an outer periphery thereof for fitting therein of a sealing member for connection to the first hose 82. The connecting portion 83b is provided for connection to the second hose 84. Numeral 131 denotes a hose clamp for clamping the second hose 84 . The engine- side mounting member 86 includes a connecting portion 86a for connection to the second hose 84. The first support member 97 and the second support member 98 comprise cylindrical portions 97a, 98a to be fitted on the second hose 84 and plate portions 97b, 98b extending sideways from the cylindrical portions 97a, 98a. Mounting holes 97c and 98c are formed in the plate portions 97b and 98b, respectively, and bolts are inserted through the mounting holes 97c and 98c to mount the first and second support members 97, 98 to the head cover 51 and the cylinder head 48, respectively. Operations of the fuel pipe structure constructed as above will be described below. Figs. 6 (a) and 6 (b) are operation diagrams showing operations of the fuel pipe structure according to the present invention. Fig. 6 (a) shows a deflected state of the second hose 84 (more particularly, the cross-hatched flexible portion 121; this is also true in the following) when the head cover 51 moves upward from the position shown in Fig, 4 by a movement quantity Ml with swing motion of the engine relative to the vehicle body frame. Numeral 141 denotes a point on the head cover 51 before movement, while numeral 142 denotes a point after movement of the point 141 with movement of the head cover 51. It is to be noted that the imaginary line in the figure represents the flexible portion 121 before the deflection. (This is also true in (b) . ) The head cover-side extending portion 125 of the second hose 84 moves substantially in parallel with the vehicle body-side extending portion 124 and substantially in the axial direction of the head cover-side extending portion 125, with no change in curvature of the U-shaped extending portion 126. Fig. 6 (b) shows a deflected state of the second hose 84, more particularly, the flexible portion 121, when the head cover 51 moves downward from the position shown in Fig. 4 by a movement quantity M2 with swing motion of the engine relative to the vehicle body frame. Numeral 143 denotes a point after movement of the point 141 with movement of the head cover 51. In the same manner as in Fig. 6 (a) , the head cover-side extending portion 125 of the second hose 84 moves substantially in parallel with the vehicle body-side extending portion 124 and substantially in the axial direction of the head cover-side extending portion 125, with no change in curvature of the U-shaped extending portion 126 . As described above in connection with Figs. 6 (a) and 6 (b) , since the head cover-side extending portion 125 moves axially, it deflects little in the vertical direction. Besides, since a mounting length LI in the vehicular transverse direction (i.e., in the vehicle width direction) of the flexible portion 121, i.e., distance LI between the vehicle body-side extending portion 124 and the head cover-side extending portion 125, is small, the amount of vertical vibrations of the U-shaped extending portion 126 is small and so is the amount of vibrations of the flexible portion 121 as a whole . Therefore, a large vertical force is exerted on neither the vehicle body-side mounting member 93 as a mounting portion on the vehicle body frame 11 side of the second hose 84 nor the first support member 97 as a mounting portion on the engine 18 side. Thus, it is not necessary to increase the rigidity of the vehicle body- side mounting member 93 and the first support member 97 and hence it is possible to attain the reduction in size and weight of both members. Figs. 7 (a) to 7 (c) are operation diagrams showing operations of a fuel pipe as a comparative example. Fig. 7 (a) shows that a fuel pipe 223 is connected rectilinearly between a discharge pipe 221 mounted on the fuel pump side and a suction pipe 222 mounted on the engine side. Fig. 7 (b) shows that the suction pipe 222 moves downward by a movement quantity M3 with swing motion of the engine, resulting in one end of the fuel pipe 223 being deflected downward. At this time, the fuel pipe 223 bends largely near the connection between the fuel pipe 223 and the discharge pipe 221 and also near the connection between the fuel pipe 223 and the suction pipe 222. That is, a bending load is imposed on the fuel pipe 223 . If a mounting length of the fuel pipe 223, i.e., distance between the discharge pipe 221 and the suction pipe 222, is assumed to be L2 , the bending angle of the fuel pipe 223 can be made small by making the mounting length L3 of the fuel pipe 223 larger than L2 , as shown in Fig. 7 (c) . However, if the mounting length L3 is made large, when the suction pipe 222 moves downward, a vibration quantity B of the fuel pipe 223 becomes large and so does the weight of the fuel pipe 233. Consequently, the forces acting on the discharge pipe 221 and the suction pipe 222 become large upon vibration of the fuel pipe 223 . Thus, if the fuel pipe 223 is mounted rectilinearly, the mounting length L2 becomes larger than the mounting length LI (see Fig. 6 (a) ) of the second hose 84 (see Fig. 6 (a) ) in the present invention and the vibration quantity of the fuel pipe 223 becomes large; besides, a large force is exerted on the mounting portion of the fuel pipe 223 . But these points can be remedied in the present invention . As described above in connection with Figs. 1, 3 and 4, in the present invention, the power unit 17 having the body portion 56 of the internal combustion engine comprising the cylinder 47 and the cylinder head 48 is secured to the vehicle body frame 11 swingably with the cylinder head 48 facing forward of the vehicle body. The fuel pump 61 (see Fig. 2) is connected to the fuel tank 16 secured to the vehicle body frame 11. The fuel injection valve 105 is disposed in the intake passage 48a formed in the body portion 56 of the internal combustion engine. The fuel pump 61 and the fuel injection valve 105 are connected with each other through the fuel pipe 62 . The vehicular fuel pipe structure according to the present invention is characterized in that the fuel pipe 62 includes at least the head cover-side extending portion 125 extending in the swing direction around the internal combustion engine body portion 56 (see Fig. 1). A part of the head cover- side extending portion 125 is supported by the first support member 97 and the second support member 98 both provided in. the internal combustion engine body portion 56. Since the head cover-side extending portion 125 is provided in the fuel pipe 62, when the power unit 17 swings, the head cover-side extending portion 125 moves in the axial direction thereof, so that it is possible to suppress the amount of vibration in the swing direction of the head cover-side extending portion 125. Consequently, the amount of vibration of the fuel pipe 62 as a whole can be diminished and it is possible to diminish the space for vibration of the fuel pipe 62. That is, other components can be disposed in proximity to the fuel pipe 62 and it is possible to construct the vehicle 10 (see Fig. 1) compactly. Moreover, since the amount of vibration of the head cover-side extending portion 125 becomes small, it is possible to diminish the forces acting on the first support member 97 and the vehicle body- side support member 93 . Accordingly, it is not necessary to increase the strength and rigidity of the first support member 97 and the vehicle body- side support member 93 and it is possible to attain the reduction in size and weight of both members . The present invention is secondly characterized in that the fuel pipe 62 includes the vehicle body-side extending portion 124 extending in the swing direction from the vehicle body-side mounting member 93 provided in the vehicle body and the U-shaped extending portion 126 extending in U shape along an outer surface of the cylinder head 48. The U-shaped extending portion 126 connects the vehicle body-side extending portion 124 and the head cover-side extending portion 125 with each other. The fuel pipe 62 is provided with the vehicle body-side extending portion 124 and the U-shaped extending portion 126. By connecting the vehicle body-side extending portion 124 and the head cover-side extending portion 125 through the U-shaped extending portion 126, the head cover- side extending portion 125 moves substantially in parallel with the vehicle body-side extending portion 124 when the power unit 17 (see Fig. 1) swings. Consequently, it is possible to diminish a change in curvature of the U-shaped extending portion 126. For example, in the present invention it is possible to diminish a change in bending rate of the fuel pipe 62 in comparison with the case where a change in bending of the fuel pipe becomes large when one end of a straight fuel pipe moves relative to an opposite end of the pipe. The present invention is thirdly characterized in that the head cover- side extending portion 125 and the vehicle body-side extending portion 124 of the fuel pipe 62 are arranged substantially side by side in the transverse direction of the vehicle body. Since the head cover-side extending portion 125 and the vehicle body-side extending portion 124 of the fuel pipe 62 are arranged substantially side by side in the transverse direction of the vehicle, the distance between both extending portions can be shortened in the longitudinal direction of the vehicle body. Besides, in Fig. 1, it is possible to let the fuel tank 16 and the body portion 56 of the internal combustion engine approach each other and hence possible to shorten the wheel base of the vehicle 10. As described above in connection with Figs. 1 and 2, the present invention is fourthly characterized in that the vehicle 10 is provided in front of the body portion 56 of the internal combustion engine with the step floor 41 for the rider to step thereon. The fuel tank 16 is disposed below the step floor 41, and the fuel pump 61 is disposed within the fuel tank 16 and is secured to the upper wall 16a of the fuel tank 16. The fuel pipe disposed above the fuel pump 61 and below the step floor 41, i.e., the tank-side mounting member 81 and the first hose 82, are formed of metal. The tube member 83 is formed of resin, and the U-shaped extending portion 126 (see Fig. 4) is formed of rubber. Since the fuel pipe 62 positioned above the fuel pump 61 and below the step floor 41 is formed of metal or resin, it is possible to suppress vertical vibrations of the fuel pipe 62 and the step floor 41 can be positioned closer to the fuel tank 16 and hence can be made lower. As described above in connection with Fig. 3, the present invention is fifthly characterized in that the cylinder head 48 includes the head cover 51 on the front side of the vehicle body, and the first support member 97 and the second support member 98 are provided in the head cover 51 and the cylinder head 48, respectively. Since the first support member 97 and the second support member 98 are provided in the head cover 51 and the cylinder head 48, respectively, when the head cover 51 is removed for maintenance, the fuel pipe 62 can be supported by the second support member 98 located on the cylinder head 48 side. Consequently, the fuel pipe 62 can be kept positioned near the mounting portion of the head cover 51 and hence it is possible to improve the working efficiency at the time of again mounting the fuel pipe 62 to the first support member 97 located on the head cover 51 side. [Fig. 8 is a side view of a principal portion of a vehicle according to another embodiment of the present invention. In this vehicle, indicated at 150, a fuel tank 148 is secured to the rear portion of the rear frame 14. In the embodiment, the same constructional portions as in the embodiment illustrated in Fig. 1 are identified by the same reference numerals as in Fig. 1, and detailed explanations thereof will be omitted. In Figs. 3 and 8, a fuel pipe 151 for conducting fuel from the fuel tank 148 to the engine 18 comprises a first hose 153 connected at one end thereof to a fuel pump (not shown) on the fuel tank 148 side and at an opposite end thereof to a tube member 152, the tube member 152, a second hose 84 connected to the tube member 152, and the engine-side mounting member 86 described above . The tube member 152 is mounted to the vehicle body-side mounting member 93 . Although in the above embodiments the flexible portion 121 of the fuel pipe 62 is formed in a downwardly projecting U shape as in Fig. 4, this constitutes no limitation. For example, it may be formed in an upwardly projecting U shape. [Industrial Applicability] The vehicular fuel pipe structure of the present invention is suitable for a two-wheeled motor vehicle. [Description of Reference Numerals] [0060] 10 ... vehicle 11 ... vehicle body frame 16 ... fuel tank 16a ... upper wall 17 ... power unit 18 ... engine 41 ... step floor 47 ... cylinder 48 ... cylinder head 48a ... intake passage 51 ... head cover 56 ... body portion of an internal combustion engine 61 ... fuel pump 62 ... fuel pipe 93 ... vehicle body-side hose support portion (vehicle body-side mounting member) 97, 98 ... pipe support portion (first support member, second support member) 124 ... vehicle body-side swing-direction extending portion (vehicle body-side extending portion) 125 ... internal combustion engine-side swing-direction extending portion (head cover-side extending portion) 126 ... U-shaped extending portion WE CLAIM: 1. A vehicular fuel pipe structure of a vehicle wherein said fuel pipe comprises at least an internal combustion engine-side swing-direction extending portion (125), a part of said extending portion (125) being supported by a pipe support portion (97), (98) provided in the body portion of the internal combustion engine, said fuel pipe includes a vehicle body-side swing-direction extending portion (124) extending from a vehicle body-side hose support portion (93) provided in the vehicle body and a U-shaped extending portion (126) extending along an outer surface of said cylinder head (48), said U-shaped extending portion (126) connecting said extending portions (124), (125) with each other, and said internal combustion engine-side swing-direction extending portion (125) and said vehicle body-side swing-direction extending portion (124) are arranged substantially side by side in the transverse direction of the vehicle body. 2. The vehicular fuel pipe structure substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

Documents:

1709-del-2004-abstract.pdf

1709-del-2004-claims.pdf

1709-del-2004-complete specification (granted).pdf

1709-del-2004-correrspondence-po.pdf

1709-del-2004-correspondence-others.pdf

1709-del-2004-description (complete).pdf

1709-del-2004-drawings.pdf

1709-del-2004-form-1.pdf

1709-del-2004-form-19.pdf

1709-del-2004-form-2.pdf

1709-del-2004-form-3.pdf

1709-del-2004-form-4.pdf

1709-del-2004-form-5.pdf

1709-del-2004-gpa.pdf

1709-del-2004-petition-137.pdf

1709-del-2004-petition-138.pdf