JP4253009B2 - Structure of fuel system in scooter type motorcycle - Google Patents

Description

  The present invention relates to a fuel system arrangement structure for supplying fuel to an engine in a scooter type motorcycle.

  Conventionally, in a scooter type motorcycle, a fuel tank is disposed under a seat on which a passenger sits on a seat and is supported by a vehicle body cover, and a fuel pipe extending from the fuel tank passes through the inside of the vehicle body cover. It is common to be connected to an engine located in front of the tank.

By the way, in a scooter type motorcycle, when a fuel system including a fuel tank having a relatively large capacity is arranged in a limited space in a body cover surrounding a body frame,
1) Preventing the wheelbase from becoming longer and preventing an increase in weight to reduce costs.
2) Lower seat height to improve boarding / exitability
3) Easy to protect and maintain the fuel system,
Etc. are required.

  An object of the present invention is to provide a fuel system arrangement structure in a novel scooter type motorcycle that can satisfy the above requirements as much as possible.

The invention according to claim 1, a traveling engine unit on the body frame to the rear of the engine unit with bound together to support the swing arm vertically swingably with a pivot shaft, wheel rear at a rear end of the swing arm A vehicle body cover covering the vehicle body frame is formed in a cross-sectional channel shape so as to cover the upper surface and both left and right side surfaces of the engine unit, and the left and right foot rests are removed from the lower sides of the left and right sides. A floor extending substantially horizontally toward the vehicle is provided, and a tunnel extending in the longitudinal direction of the vehicle body is formed between the channel-shaped portion of the cross section of the floor and the engine unit, and is supported by the vehicle body frame. A fuel system piping structure in a scooter type motorcycle in which a fuel tank and a fuel pipe are connected between the fuel tank and the engine unit. The engine unit is supported by the vehicle body frame with the cylinder of the engine body at the front, and the fuel tank is above the engine unit and below the seat, and the bottom wall of the tank and the top surface of the engine unit. is arranged so as to overlap in close proximity bets with each other, the fuel pipe extends downward along the fuel tank, yet within said tunnel, with and extends forwardly along the upper and side surfaces of the engine unit The connection end of the fuel pipe on the engine unit side is arranged at the upper part of the engine body .

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, a connection end of the fuel pipe on the engine unit side is connected to an intake system that is connected to an upper portion of the engine body and is directed obliquely forward. It is characterized by being.

  Furthermore, in the invention of claim 3, in addition to the configuration of claim 1 or 2, a part of the fuel pipe passing through the tunnel is curved in a downwardly protruding arc shape on the side of the engine unit. According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, a part of the fuel pipe is arranged in the vehicle width direction above the engine body at the front of the engine unit. The invention of claim 5 is characterized in that, in addition to any of the features of claims 1 to 4, a part of the fuel pipe passing through the tunnel is part of the body frame in the tunnel. It extends in the longitudinal direction of the vehicle body along the upper part of the vehicle.

  As described above, according to the present invention, in the fuel system arrangement structure in the scooter type motorcycle, the fuel tank and the engine unit can be arranged close to each other, and the total length of the fuel pipe can be shortened. In addition, since the fuel pipe passes through the tunnel between the cross-section channel-like portion of the floor of the vehicle body cover and the engine unit, the fuel pipe can be protected by the floor of the vehicle body cover by effectively using the dead space.

  Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

  An embodiment of the present invention will be described with reference to FIGS.

  In the following description, “up, down”, “left, right”, and “front, rear” are based on the traveling direction of the motorcycle.

  FIG. 1 is a partially broken side view of a scooter type motorcycle having a fuel system arrangement structure of the present invention, FIG. 2 is a plan view of a scooter type motorcycle excluding a vehicle body cover and a seat, and FIG. 1 is an enlarged view of a portion surrounded by an imaginary line 3 shown in FIG. 1, FIG. 4 is a longitudinal sectional view taken along line 4-4 in FIG. 2, and FIG. 5 is a longitudinal sectional view taken along line 5-5 in FIG.

1 and 2, a vehicle body frame F which is a skeleton of a motorcycle is configured by integrally connecting a front frame Ff, a traveling engine unit Eu, and a rear frame Fr. The front frame Ff includes a head pipe 1 and a bifurcated main pipe 2 that integrally extends downward and rearward therefrom. The main pipe 2 is a square pipe. As usual, a front fork 3 having a front wheel Wf pivoted on a lower end is supported on the head pipe 1 so as to be steerable. A steering handle 4 is fixed to the upper end of the front fork 3. The upper part of the engine unit Eu is fixed to the lower end of the main pipe 1 and the lower end of the support frame 5 extending downward from the main pipe 1 by a plurality of coupling bolts 6. The part is suspended and supported by the front frame Ff. Engine unit Eu has a horizontally opposed type engine main body 7 in front thereof, the engine body 7, the left-right direction, a pair of cylinders ₇₁ which extend substantially horizontally outward, and the crankshaft Extends in the front-rear direction. The rear transmission portion 8 of the engine unit Eu is suspended and supported by the rear frame Fr.

  The rear frame Fr is formed in a frame shape with its upper and lower surfaces opened by a rear pipe 10, a seat rail 11 above the rear pipe 10, and a plurality of connecting pipes 12 that integrally couple them, and a helmet is formed therein. An H storage box B is provided. The front end of the rear pipe 10 is integrally connected to both sides of the rear end of the transmission case of the transmission unit 8 of the engine unit Eu by connecting bolts 13 and extends rearwardly upward, while the seat rail 11 has its left and right sides. Both ends are integrally connected to the upper left and right sides of the engine unit Eu by connecting bolts 14 and extend rearwardly above the rear pipe 10 substantially in parallel with the rear pipe 10. The rear pipe 10 and the rear end of the seat rail 11 are integrally connected by a connecting pipe 12.

  Most of the vehicle body frame F constituted by the front frame Ff, the engine unit Eu, and the rear frame Fr is covered with a vehicle body cover C made of a synthetic resin plate or a metal plate of a monocoque.

  A swing arm 18 is pivotally supported by a pivot shaft 19 so as to be swingable in a vertical direction at a lower portion of the transmission case of the transmission unit 8 at the rear of the engine unit Eu. A wheel Wr is rotatably supported, and a rear damper 20 is connected between the swing arm 18 and the rear frame Fr. A conventionally known power transmission mechanism (not shown) is accommodated in the swing arm 18, and the power of the engine unit Eu is transmitted to the rear wheel Wr via this power transmission device. Further, a footrest frame 9 that protrudes to the side is fixed to the lower portion of the engine unit Eu.

  In the rear frame Fr, a space part opened in the vertical direction is formed above the rear wheel Wr, and the storage box B of the helmet H is accommodated in the space part. The storage box B is formed in a square box shape in plan view with an entrance opening on the upper surface by a metal plate or a synthetic resin plate, and is fixedly supported by the rear frame Fr in a detachable manner.

  A tire house 30 is formed on the bottom wall of the storage box B so that the upper surface of the rear wheel Wr faces. The tire house 30 is formed in an arch shape at the center in the left-right direction of the bottom wall in the front-rear direction into the storage box B, and the tire house 30 includes an upper surface of the rear wheel Wr. Is facing. By forming the tire house 30, the storage box B can be disposed close to the rear wheel Wr.

  As clearly shown in FIG. 3, a pair of support arms 22 that are inclined forward and forward are fixed to the front left and right of the seat rail 11 constituting the rear frame Fr. A front support plate 23 of a tandem seat S that is long in the front-rear direction, on which an occupant sits, is pivotally supported by a hinge shaft 32 that is pivotally mounted on the front end of the tandem. The hinge shaft 32 can be opened and closed rearwardly. The upper surface of the vehicle body cover C immediately below the tandem seat S is opened 24. When the tandem seat S is closed, the tandem seat S closes the opening 24, and the tandem seat S is stored in the storage box. Close the entrance of B.

  Next, a fuel system that is a feature of this embodiment for supplying fuel to the engine main body 7 of the engine unit Eu will be described with reference to FIGS. A fuel tank Tf made of a synthetic resin is disposed below the front half of the fuel tank, and the fuel tank Tf is supported by the rear frame Fr. The front half of the fuel tank Tf is shallow and extends above the transmission unit 8 of the engine unit Eu. The front half of the fuel tank Tf and the transmission unit 8 overlap each other in the front-rear direction, and the bottom wall of the fuel tank Tf and the upper surface of the transmission unit 8 are arranged as close as possible to each other. As a result, the wheel base of the motorcycle can be shortened and the seat height can be lowered.

  As shown in FIGS. 2 and 3, the pipe connection portion 26 at the upper part of the fuel tank Tf has one end of a fuel supply pipe Ps and a fuel return pipe Pr made of a flexible tube such as a hose as the fuel pipe P. Each is connected. Both the fuel supply pipe Ps and the fuel return pipe Pr extend downward from the lower surface of the seat S along the front surface of the fuel tank Tf after passing below the hinge shaft 32 of the seat S. The engine unit Eu extends forward along the side surface from the upper surface. The other end of the fuel supply pipe Ps is connected to one carburetor 27l of the pair of left and right carburetors 27l and 27r of the engine body 7 of the engine unit Eu, and further to the other carburetor 27r via the communication pipe 28. It is communicated. On the other hand, the fuel return pipe Pr is connected to a fuel return portion of the engine body 7. During operation of the engine unit Eu, the fuel in the fuel tank Tf is supplied from the fuel pump 29 in the tank Tf to the left and right carburetors 27l and 27r via the fuel supply pipe Ps and the communication pipe 28, and the engine unit Eu. Unburned fuel such as evaporated fuel from the fuel is returned to the fuel tank Tf through the fuel return pipe Pr. Further, as shown in FIG. 1, the middle of the fuel supply pipe Ps is curved in a downwardly convex arc shape on the side of the engine unit Eu.

  As shown in FIGS. 4 and 5, a portion of the vehicle body cover C made of a metal plate or a synthetic resin plate that covers the engine unit Eu constitutes a floor 31, and the floor 31 includes an upper surface of the engine unit Eu and It is formed in a cross-sectional channel shape so as to cover both the left and right side surfaces, and further, the left and right side lower sides protrude outwards substantially horizontally to form wide left and right foot rests 31l and 31r. The right foot rests 31l and 31r are supported by a foot rest frame 9 that integrally projects outward from the left and lower right portions of the engine unit Eu. The channel-shaped portion of the cross section of the floor 31 forms a tunnel Tu extending in the front-rear direction between the upper surface of the engine unit Eu, and a flexible fuel supply pipe Ps and fuel are formed in the tunnel Tu. The return pipe Pr extends in the front-rear direction.

  Therefore, both the fuel supply pipe Ps and the fuel return pipe Pr can be arranged using a dead space between the floor 31 of the vehicle body cover C and the engine unit Eu, and these pipes Ps and Pr are connected to the floor. In addition, the pipes Ps and Pr are not interfered with the sheet S even when the sheet S is opened and closed.

  A battery box Ba containing a battery is disposed between the fuel tank Tf and the storage box B, and is supported by a cross member 35 that is horizontally mounted on the rear pipe 10. Thus, the shallow front portion of the storage box B projects over the battery box Ba, and the front wall of the storage box B is brought as close as possible to the rear wall of the fuel tank Tf. The capacity of the fuel tank Tf or the storage box B can be increased while shortening the wheel base of the motorcycle.

  Next, the operation of this embodiment will be described.

  According to the operation of the motorcycle, the fuel in the fuel tank Tf is supplied to the engine body 7 through the fuel supply pipe Ps, the one carburetor 27l, the communication pipe 28, and the other carburetor 27r. Further, unburned fuel such as evaporated fuel in the engine unit Eu is returned to the fuel tank Tf through the fuel return pipe Pr.

  Thus, since both the fuel supply pipe Ps and the fuel return pipe Pr as the fuel pipe P are inserted through the tunnel Tu formed between the engine unit Eu and the floor 31 of the vehicle body cover C, dead fuel pipe Ps. It is possible to arrange the pipes Ps and Pr using the space effectively, and to make the total length of the pipes Ps and Pr as short as possible. In addition, the pipes Ps and Pr can be protected by the floor 31. The fuel supply pipe Ps and the fuel return pipe Pr both extend under the hinge shaft 32 of the seat S and below the seat S, and are connected to the pipe connection portion 26 of the fuel tank Tf. Therefore, the sheet S does not interfere with the opening / closing operation of the sheet S.

  In the figure, reference numeral 38 denotes a grip that is fixed to the seat rail 11 so as to surround the rear portion of the seat S.

  As mentioned above, although the Example of this invention was described, this invention is not limited to the Example, A various Example is possible within the scope of the present invention. For example, the seat may be constituted by a front seat and a rear seat divided into front and rear. Further, the engine body of the engine unit may be a model other than the horizontally opposed type.

Partially cutaway side view of a scooter type motorcycle equipped with a fuel system arrangement structure Top view of scooter type motorcycle without body cover and seat Enlarged view of the phantom line encircled portion in FIG. Longitudinal section along line 4-4 in FIG. Longitudinal sectional view along line 5-5 in FIG.

Explanation of symbols

31 ... Floor 32 ... Hinge shaft C ... Car body cover Eu ... Engine unit P ... Fuel piping S ... Seat Tf ... Fuel tank Tu ... Tunnel

Claims (5)

The vehicle running engine unit on the body frame (F) (Eu) to the rear of the engine unit with bound together (Eu), supporting a pivot shaft (19) swing arm with a (18) vertically swingably, the A vehicle body cover (C) that rotatably supports a rear wheel (Wr) at the rear end of the swing arm (18) and covers the vehicle body frame (F) is provided on the upper surface and both left and right side surfaces of the engine unit (Eu). A floor (31) is formed which is formed in a channel shape so as to cover and the left and right foot rests (31l, 31r) project substantially horizontally toward the outside from the lower left and right sides, and the floor (31 ) Between the engine unit (Eu) and the cross-sectional channel-shaped portion of the cross section, and a tunnel (Tu) extending in the longitudinal direction of the vehicle body is formed and supported by the vehicle body frame (F). A fuel tank (Tf), the between the engine unit (Eu) a piping structure of a fuel system in a scooter type motorcycle connected by a fuel pipe (P),
The engine unit (Eu) is supported by the vehicle body frame (F) with the cylinder (7 ₁ ) of the engine body (7) as a front portion,
The fuel tank (Tf) is located above the engine unit (Eu) and below the seat (S), with the bottom wall of the tank (Tf) and the top surface of the engine unit (Eu) close to each other. Arranged to overlap,
The fuel pipe (P) extends downward along the fuel tank (Tf), and further extends forward along the upper surface and side surfaces of the engine unit (Eu) in the tunnel (Tu) . A fuel system arrangement structure in a scooter type motorcycle, wherein a connecting end of the fuel pipe (P) on the engine unit (Eu) side is arranged on an upper part of the engine body (7) .   The connection end of the fuel pipe (P) on the engine unit (Eu) side is connected to the upper part of the engine body (7) and connected to an intake system (271, 27r) directed obliquely forward. The fuel system arrangement structure in a scooter type motorcycle according to claim 1,   A part of the fuel pipe (P) passing through the tunnel (Tu) is curved in a downwardly convex arc shape on the side of the engine unit (Eu). 3. A fuel system arrangement structure in the scooter type motorcycle according to 2.   The part (28) of the fuel pipe (P) passes in the vehicle width direction above the engine body (7) at the front of the engine unit (Eu). A fuel system arrangement structure in any one of the scooter type motorcycles.   A part of the fuel pipe (P) passing through the tunnel (Tu) extends in the longitudinal direction of the vehicle body along the upper part of the vehicle body frame (F) in the tunnel (Tu). The arrangement structure of the fuel system in the scooter type motorcycle according to any one of claims 1 to 4.

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