JP2008143340A - Motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the efficiency of the assembling work of a return pipe in a motorcycle having a fuel tank arranged above an engine. <P>SOLUTION: The motorcycle is provided with the engine 14; the fuel tank 12 arranged above the engine 14; a filter device arranged in a position lower than that of the fuel tank 12 and filtering fuel from the fuel tank 12; a fuel injection pump 22 for injecting fuel passed through the filter device 21 to the inside of an intake passage 31 of the engine 14; and the return pipe 28 for returning evaporation gas V from the fuel injection pump 22 to the fuel tank 12. The fuel tank 12 is relatively movable from the fuel injection pump 22, and the return pipe 28 is connected to the bottom wall 40b side of the fuel tank 12. In the return pipe 28, a connection position A to the fuel tank 12 is relatively movable to a connection portion C to the fuel injection pump 22. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel tank, a filter device that is disposed lower than the fuel tank and filters fuel from the fuel tank, and a fuel injection pump that injects fuel that has passed through the filter device into an intake passage to the engine And a motorcycle including a return pipe for returning the evaporated gas from the fuel injection pump to the fuel tank.

  In a conventional fuel injection system (FI system), fuel in a fuel tank is constantly pressurized by a fuel pump, adjusted to a constant pressure by a regulator, and fuel that has passed through a high-pressure filter device passes from the fuel tank through a high-pressure pipe. It is metered and injected into the intake passage to the engine by an injector.

On the other hand, in the fuel supply device used in a small motorcycle such as a scooter newly proposed in Patent Document 1, the functions of the fuel pump, the regulator, and the injector are integrated into one fuel injection pump, and the fuel injection pump Is arranged lower than the liquid level in the fuel tank, and fuel is supplied at low pressure from the fuel tank to the fuel injection pump through the filter device by the water head pressure. The evaporative gas generated by the fuel injection pump is returned by a return pipe connected to the fuel tank so as to communicate with the air layer in the fuel tank. According to this fuel supply device, since power is supplied and pressurized only at the time of fuel injection, power consumption can be reduced, and since fuel is supplied at a low pressure, pipes and filters, etc., are not used. The cost of used parts can also be reduced.
JP 2004-278526 A

  However, when the configuration proposed in Patent Document 1 is newly applied to a medium- or large-sized motorcycle, the fuel tank is arranged between the handle and the rider, which also serves as a design. In fact, it is impossible to connect the return pipe to the side wall of the fuel tank. In addition, when considering connecting the return pipe to the bottom wall of the fuel tank, the engine etc. are densely arranged directly under the fuel tank, so there is not much work space for the assembly workers to access. As a result, the assembly workability is significantly reduced.

  Therefore, an object of the present invention is to improve the return pipe assembly workability in a motorcycle in which a fuel tank is disposed above an engine.

  The present invention has been made in view of the circumstances as described above, and a motorcycle according to the present invention includes an engine, a fuel tank disposed above the engine, and a fuel tank disposed lower than the fuel tank. A filter device that filters fuel from a fuel tank, a fuel injection pump that injects fuel that has passed through the filter device into an intake passage to the engine, and a return pipe that returns evaporated gas from the fuel injection pump to the fuel tank The fuel tank is movable relative to the fuel injection pump, and the return pipe has one end connected to the fuel tank on the bottom wall side and the other end connected to the fuel injection pump. It is connected, and either one of the one end and the other end is configured to be relatively movable with respect to the other.

  In this way, even if the engine is arranged below the fuel tank and there is not much work space for the assembly worker to connect the return pipe to the fuel tank on the bottom wall side, the return pipe Since the connecting portion with the fuel tank can be moved relative to the connecting portion with the pump, the connecting operation can be performed while moving the fuel tank to avoid the interference. Therefore, it is possible to improve the return pipe assembly workability.

  The return pipe has a circulation pipe for returning surplus fuel from the fuel injection pump to the upstream side of the fuel injection pump, one end of the circulation pipe is branched and connected to the fuel tank, and the other end is connected to the fuel tank. The connecting pipe may have a structure in which one end of the connecting pipe is movable relative to the other end.

  If it does in this way, since one end part of a connection pipe can move relatively to the other end part, connection work can be performed, moving a fuel tank and avoiding an interference object. Therefore, it is possible to improve the return pipe assembly workability.

  The fuel tank is attached to the vehicle body frame so as to be pivotable upward with its front portion as a pivot, and a connection portion between the connection pipe and the fuel tank is a connection between the connection pipe and the circulation pipe. You may arrange | position near the said rotation fulcrum rather than a part.

  In this case, the connecting portion between the connecting pipe and the fuel tank is close to the rotation fulcrum of the fuel tank. Therefore, even if the working space is secured by rotating the fuel tank upward, the position of the connecting portion varies. Therefore, the connecting work can be easily performed without providing an extra length in the connecting pipe.

  The connecting pipe may have flexibility.

  If it does in this way, since a connection pipe has flexibility, even if it moves a fuel tank, an assembly operator can connect a connection pipe to a circulation pipe easily.

  A protective member may be attached to the outer peripheral surface of the connecting pipe.

  If it does in this way, even when the connecting pipe which has flexibility vibrates by vehicle vibration etc. and contacts other members in the neighborhood, damage to the connecting pipe can be prevented suitably.

  The fuel tank integrally has a built-in pipe that penetrates the bottom wall portion thereof and communicates with an air layer in the fuel tank, and is provided at a lower end portion of the built-in pipe that projects downward from the bottom wall portion. By connecting the return pipe, the return pipe may be connected to the fuel tank.

  If it does in this way, evaporation gas can be led to the air layer in a fuel tank via a built-in pipe, connecting a return pipe to the bottom wall side of a fuel tank.

  The bottom wall portion of the fuel tank is at least partially raised and has a bottom shape, and a connection portion between the return pipe and the fuel tank is located above the lowermost surface of the fuel tank and is located in the fuel tank in a side view. It may be covered.

  In this case, the connecting portion between the return pipe and the fuel tank is disposed in the raised bottom space of the fuel tank and the engine or the like is disposed below the fuel tank. However, since the return pipe can move relative to the connecting part with the fuel injection pump, the connecting part of the return pipe can be connected to each other while moving the fuel tank to avoid interference. It can be carried out. Therefore, it is possible to effectively improve the return pipe assembly workability.

  As is clear from the above description, according to the present invention, the assembly workability of the return pipe can be improved in the motorcycle in which the fuel tank is arranged above the engine.

  Embodiments according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a left side view of a motorcycle 1 according to an embodiment of the present invention. Note that the concept of direction used in the present embodiment will be described as being consistent with the concept of direction viewed from a rider who has boarded the motorcycle 1.

  As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 and a rear wheel 3, and the front wheel 2 is rotatably supported by a lower portion of a front fork 4 extending substantially in the vertical direction. The front fork 4 is supported by the steering shaft 7 via an upper bracket 5 provided at an upper end portion thereof and an under bracket 6 provided below the upper bracket 5. The steering shaft 7 is rotatably supported by the head pipe 8. A bar-type steering handle 9 extending to the left and right is attached to the upper bracket 5. Therefore, the rider can turn the front wheel 2 in a desired direction by operating the steering handle 9 with the steering shaft 7 as the rotation axis.

  A vehicle body frame 10 extends rearward from the head pipe 8. A front end 11 a of a swing arm 11 is pivotally supported on the body frame 10, and the rear wheel 3 is rotatably supported on the rear end of the swing arm 11. A fuel tank 12 is provided above the vehicle body frame 10 and behind the steering handle 9, and a riding seat 13 is provided behind the fuel tank 12. An engine 14 is mounted almost directly below the fuel tank 12. The engine 14 is an upright single-cylinder four-cycle engine erected in a substantially vertical direction, and a crankcase 15 is provided below the cylinder 42. A gear case 16 is provided at the rear part of the crankcase 15, and its output is transmitted to the rear wheel 3 via the chain 17.

  A throttle body 18 having an intake passage 31 (see FIG. 2) for adjusting the intake air amount by a butterfly valve 23 (see FIG. 2) is connected to the rear portion of the engine 14. An intake duct 19 having an intake passage whose upstream side communicates with an air cleaner (not shown) is connected to the rear portion of the throttle body 18. The throttle body 18 is provided with a known fuel injection pump 22 that integrates the functions of the fuel pump, the regulator, and the injector. A fuel tap 20 is attached to the fuel tank 12, and the fuel flowing down from the fuel tap 20 is supplied to the fuel injection pump 22 via the filter device 21.

  FIG. 2 is a conceptual diagram illustrating a fuel supply system of the motorcycle 1 shown in FIG. As shown in FIG. 2, a fuel tap 20 is attached to the fuel tank 12 so that the fuel in the fuel tank 12 can flow down to open and close the fuel flow path. One end of the first feed pipe 24 is connected to the fuel tap 20, and the other end of the first feed pipe 24 is connected to the filter device 21 on the upstream side of the filter element (not shown). The filter device 21 is installed at a position lower than the fuel tank 12. One end of a second feed pipe 25 is connected to the filter device 21 on the downstream side of a filter element (not shown). The other end of the second feed pipe 25 is connected to the fuel injection pump 22 so that fuel is metered and injected from the fuel injection pump 22 into the intake passage 31 in the throttle body 18.

  A circulation pipe 26 that returns excess fuel from the fuel injection pump 22 to the filter device 21 (that is, upstream of the fuel injection pump 22) is connected to the fuel injection pump 22. The circulation pipe 26 is connected to the filter device 21 on the downstream side of the filter element (not shown). The circulation pipe 26 is connected to a flexible connecting pipe 27 that is branched and connected upward. That is, the return pipe 28 for returning the evaporated gas V generated by the fuel injection pump 22 and the like to the fuel tank 12 is constituted by the circulation pipe 26 and the connecting pipe 27. The fuel tank 12 has a built-in pipe 29 that is integrally penetrated and fixed, and an opening of the built-in pipe 29 projects into an air layer (a space portion when full) in the fuel tank 12. The upper end portion of the connecting pipe 27 is connected to the lower end portion projecting downward from the built-in pipe 29.

  The fuel flow will be described with reference to FIG. 2. The fuel that has flowed down from the fuel tank 12 through the fuel tap 20 through the first feed pipe 24 is filtered by the filter device 21 and then injected through the second feed pipe 25. It is supplied to the pump 22. Excess fuel in the fuel injection pump 22 is returned to the filter device 21 via the circulation pipe 26. The evaporative gas V generated by heat from the outside in the fuel injection pump 22 floats inside the return pipe 28 (circulation pipe 26, connection pipe 27) and the built-in pipe 29 and is returned to the fuel tank 12.

  FIG. 3 is an enlarged left side view of the vicinity of the fuel tank of the motorcycle 1 shown in FIG. 4 is a partial cross-sectional rear view of the motorcycle 1 shown in FIG. As shown in FIG. 4, the fuel tank 12 has a metal inner panel 40 that mainly forms a bottom wall portion and a metal outer panel 41 that forms a dome-shaped outer wall portion, and is welded to each other. The fuel space is formed by joining with the like. In particular, the inner panel 40 has a raised bottom shape, the left and right first bottom wall portions 40a that are the lowermost surfaces, the second bottom wall portion 40b of the raised bottom portion positioned between them, the first bottom wall portion 40a, It has the inclined 3rd bottom wall part 40c which continues the 2 bottom wall part 40b. That is, the fuel tank 12 has a center portion in the left-right direction that is recessed upward when viewed from the back. In the space where the fuel tank 12 is raised, the vehicle body frame 10 is inclined and arranged obliquely downward. The fuel tap 20 is attached to the first bottom wall portion 40a on the left side when the fuel tank 12 is viewed from the back. A filter device 21 is connected to the fuel tap 20 via a first feed pipe 24, and the filter device 21 is disposed substantially immediately below the intake duct 19.

  As shown in FIGS. 3 and 4, a fuel injection pump 22 is connected to the filter device 21 via a second feed pipe 25, and the fuel injection pump 22 is attached to the upper portion of the throttle body 18. That is, since the filter device 21 and the fuel injection pump 22 are disposed at a position lower than the fuel tank 12, the fuel head pressure of the fuel in the fuel tank 12 causes a low pressure to the fuel injection pump 22 through the filter device 21. The fuel is supplied.

  A circulation pipe 26 that returns excess fuel from the fuel injection pump 22 to the filter device 21 is connected to the fuel injection pump 22. The circulation pipe 26 includes a first pipe 32 having one end portion 32a directly connected to the fuel injection pump 22, and a separator 33 having an input side connected to the other end portion 32b of the first pipe 32 and branching the output side in two directions. And a second pipe 34 having an upper end connected to the lower part of the output side where the separator 33 is branched. The lower end of the second pipe 34 is connected to the filter device 21. The separator 33 is fixed to the vehicle body frame 10 that passes through the raised bottom space below the second bottom wall portion 40b of the fuel tank 12 by a fixing member 35.

  A lower end portion 27a of a flexible connecting pipe 27 made of a rubber tube or the like is connected to an upper portion on the output side where the separator 33 is branched. Connected to the upper end portion 27b of the connecting pipe 27 is a lower end portion 29a of a built-in pipe 29 that is passed through and fixed to the second bottom wall portion 40b of the fuel tank 12 by brazing or the like. A lower end portion 29a of the built-in pipe 29 of the fuel tank 12 protrudes downward from the second bottom wall portion 40b. The built-in pipe 29 has an inverted L shape, and its upper part protrudes into the air layer above the liquid level when the fuel tank 12 is full, and has an opening 29b with a mesh filter (not shown). is doing. The lower end portion 27 a of the connection pipe 27 is fastened to the upper portion of the separator 33 by a clamp member 36, and the upper end portion 27 b of the connection pipe 27 is fastened to the lower end portion 29 a of the built-in pipe 29 by a clamp member 37. .

  Further, a protective member 38 for protecting the vehicle from being in contact with the vehicle body frame 10 disposed in the vicinity in the front-rear direction along the connection pipe 27 is provided at an intermediate portion of the connection pipe 27. Further, the connecting portion A between the upper end portion 27 a of the connecting pipe 27 and the lower end portion 29 a of the built-in pipe 29 (that is, the connecting portion A between the return pipe 28 and the fuel tank 12), or the lower end portion 27 a of the connecting pipe 27 and the separator 33. And the connection portion C between the one end portion 32a of the first pipe 32 of the circulation pipe 26 and the fuel injection pump 22 are located above the first bottom wall portion 40a that is the lowermost surface of the fuel tank 12. It is located and is covered with the fuel tank 12 in side view. Therefore, these connection parts A, B, and C are hidden so that they cannot be visually recognized from the outside, and the design is good.

  Further, a bearing portion (tank front support portion) 42 having a horizontal axis is attached to the front portion of the fuel tank 12, and a rotation shaft 39 having a horizontal axis provided on the vehicle body frame 10. The bearing portion 42 is rotatably fitted to the shaft. That is, the fuel tank 12 can be rotated upward together with the built-in pipe 29 using the rotation shaft 39 as a rotation fulcrum. Further, the connection portion A between the upper end portion 27 b of the connection pipe 27 and the lower end portion 29 a of the built-in pipe 29 is closer to the rotating shaft 39 than the connection portion B between the lower end portion 27 a of the connection pipe 27 and the separator 33. .

  FIG. 5 is a view for explaining a state in which the fuel tank 12 shown in FIG. 3 is rotated upward. As shown in FIG. 5, when the rear portion of the fuel tank 12 is lifted, the fuel tank 12 rotates upward with the axis of the rotation shaft 39 as a rotation fulcrum. At that time, the connecting pipe 27 has flexibility, and the upper end portion 27b can move relative to the lower end portion 27a. Therefore, the fuel tank 12 can be rotated without difficulty. Furthermore, the connection portion A between the upper end portion 27 b of the connection pipe 27 and the lower end portion 29 a of the built-in pipe 29 is closer to the rotating shaft 39 than the connection portion B between the lower end portion 27 a of the connection pipe 27 and the separator 33. Therefore, even if the fuel tank 12 is rotated upward, the position fluctuation of the lower end portion 29a of the built-in pipe 29 and the distance fluctuation between both ends of the connecting pipe 27 are relatively reduced.

  According to the above configuration, as shown in FIGS. 3 and 4, the connection portion A between the connection pipe 27 and the built-in pipe 29 and the connection portion B between the connection pipe 27 and the circulation pipe 26 are the raised bottom space of the fuel tank 12. Since the engine 14 and the like are arranged below the fuel tank 12 and there is not much work space, it is very difficult to connect the connecting pipe 27 to the circulation pipe 26 or the built-in pipe 29 as it is. However, as shown in FIG. 5, both end portions 32a and 27b of the return pipe 28 can move relative to each other, that is, both end portions 27a and 27b of the flexible connecting pipe 27 can move relative to each other. The attaching operator can perform the connection work while rotating the fuel tank 12 upward to avoid the interference. Therefore, the assembly workability of the return pipe 28 can be improved.

  For example, at the time of assembling, the work tank 12 is rotated upward with the axis of the rotation shaft 39 as a fulcrum while the upper end 27b of the connecting pipe 27 is connected in advance to the lower end 29a of the built-in pipe 29. The lower end 27a may be connected to the separator 32 of the circulation pipe 26 while the connecting pipe 27 is bent. The fuel tank 12 may be removed from the front side toward the rear upper side, and the connection portion A between the upper end portion 27b of the connection pipe 27 and the lower end portion 29a of the built-in pipe 29 may be attached or removed.

  Further, the connecting portion A between the return pipe 28 and the built-in pipe 29, that is, the connecting portion A between the connecting pipe 27 and the built-in pipe 29 is close to the rotating shaft 39 of the fuel tank 12. Even if it is rotated, the position fluctuation of the lower end portion 29a of the built-in pipe 29 and the distance fluctuation between the both end portions 27a and 27b of the connecting pipe 27 are reduced, and the connecting work can be easily performed even if the extra length is not provided in the connecting pipe 27 It can be carried out.

  In the above-described embodiment, an upright single cylinder engine is illustrated. However, the present invention is not limited to this, and may be, for example, a 2-4 cylinder, an inline type, a horizontally opposed type, or a V type engine. . The motorcycle according to the present invention is not limited to the above-described embodiment, and the configuration can be changed, added, or deleted without departing from the spirit of the present invention.

  As described above, the motorcycle according to the present invention has an excellent effect of improving the workability of assembling the return pipe, and can be widely applied to medium and large-sized motorcycles that can demonstrate the significance of this effect. it can.

1 is a left side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a conceptual diagram illustrating a fuel supply system of the motorcycle shown in FIG. 1. FIG. 2 is a left side view in which a vicinity of a fuel tank of the motorcycle shown in FIG. 1 is enlarged and displayed. FIG. 2 is a partial cross-sectional rear view of the motorcycle shown in FIG. 1 as viewed from the rear in the vicinity of a fuel tank. It is drawing explaining the state which rotated the fuel tank shown in FIG. 3 upwards.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 10 Body frame 12 Fuel tank 14 Engine 21 Filter apparatus 22 Fuel injection pump 26 Circulation pipe 27 Connection pipe 28 Return pipe 29 Built-in pipe 38 Protection member V Evaporative gas

Claims (7)

An engine, a fuel tank disposed above the engine, a filter device disposed lower than the fuel tank to filter fuel from the fuel tank, and an intake passage for the fuel that has passed through the filter device to the engine A fuel injection pump that injects into the fuel tank, and a return pipe that returns the evaporated gas from the fuel injection pump to the fuel tank.
The fuel tank is relatively movable from the fuel injection pump;
The return pipe has one end connected to the fuel tank on the bottom wall side and the other end connected to the fuel injection pump.
One of the one end and the other end is configured to be relatively movable with respect to the other. The return pipe has a circulation pipe for returning surplus fuel from the fuel injection pump to the upstream side of the fuel injection pump, one end of the circulation pipe is branched and connected to the fuel tank, and the other end is connected to the fuel tank. Connecting pipes,
The motorcycle according to claim 1, wherein one end portion of the connection pipe is relatively movable with respect to the other end portion. The fuel tank is attached to the vehicle body frame so as to be pivotable upward with its front portion as a pivot point.
The motorcycle according to claim 2, wherein a connection portion between the connection pipe and the fuel tank is disposed closer to the rotation fulcrum than a connection portion between the connection pipe and the circulation pipe.   The motorcycle according to claim 2 or 3, wherein the connecting pipe has flexibility.   The motorcycle according to claim 4, wherein a protective member is attached to an outer peripheral surface of the connection pipe. The fuel tank integrally has a built-in pipe that penetrates through a bottom wall portion thereof and communicates with an air layer in the fuel tank.
6. The automatic according to claim 1, wherein the return pipe is connected to the fuel tank by connecting the return pipe to a lower end portion of the built-in pipe protruding downward from the bottom wall portion. Motorcycle. The bottom wall of the fuel tank is at least partially raised and has a bottom shape;
The motorcycle according to any one of claims 1 to 6, wherein a connection portion between the return pipe and the fuel tank is located above the lowermost surface of the fuel tank and is covered with the fuel tank in a side view. .

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