JP2008138617A - Motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a filter structure of a return pipe in a motorcycle having a metallic fuel tank. <P>SOLUTION: This motor cycle has the metallic fuel tank 12, a filter device 21 arranged lower than the fuel tank 12 and filtering fuel flowing down from the fuel tank 12, a fuel injection pump 22 injecting the fuel passed through the filter device 21 into an intake flow passage 41 to an engine 14, and the return pipe 27 sending back evaporated gas V from the fuel injection pump 22 to the fuel tank 12. The return pipe 21 has a metallic pipe 34 fixed to the fuel tank 12 in a state of projecting to an air layer above an upper limit liquid level FL in the fuel tank 12. An opening 34c is arranged above the upper limit liquid level FL in the metallic pipe 34. A metallic filter 40 is integrally installed in the opening 34c. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes a metal fuel tank, a filter device that is disposed lower than the fuel tank and filters fuel from the fuel tank, and fuel that has passed through the filter device is injected into an intake passage to an engine. The present invention relates to a motorcycle including a fuel injection pump that performs the above operation and a return pipe that returns 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 air passage to the engine by the 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 used as a fuel. The fuel is disposed lower than the liquid level in the tank, and the fuel is supplied from the fuel tank to the fuel injection pump through the filter device by the water head pressure at a low pressure. The evaporative gas generated by the fuel injection pump is returned by a return pipe connected to the fuel tank. A resin pipe is formed at the end of the return pipe protruding into the air layer in the fuel tank. A filter member is press-fitted. 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, if the configuration proposed in Patent Document 1 is to be applied to medium and large-sized motorcycles, the fuel tank is made of metal, so the resin filter member is deformed in the heating process of the fuel tank coating, There is a possibility that the filter member may fall off from the end opening of the return pipe. That is, in a small two-wheeled vehicle such as a scooter, the fuel tank is made of resin, and the heating process of the fuel tank becomes unnecessary, so there is no fear of dropping of the resin filter member press-fitted into the end opening of the return pipe.・ This is a problem for large motorcycles. As described above, when a fuel injection pump is applied to a fuel supply system in a motorcycle having a metal fuel tank, inconvenience occurs in a filter of a return pipe. Therefore, it is currently applied only to a small motorcycle such as a scooter. .

  Therefore, an object of the present invention is to improve the filter structure of the return pipe in a motorcycle having a metal fuel tank.

  The present invention has been made in view of the above circumstances, and a motorcycle according to the present invention is disposed lower than a metal fuel tank and the fuel tank, and filters fuel from the fuel tank. A filter device; 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. Has a metal pipe fixed to the fuel tank in a state of projecting into an air layer above the upper liquid level in the fuel tank, and the metal pipe is provided with an opening above the upper liquid level. A metal filter is integrally attached to the opening.

  In this way, the metal pipe is fixed to the metal fuel tank, and the metal filter is integrally attached to the opening of the metal pipe, so the filter is not easily thermally deformed even in the heating process of the fuel tank, It is possible to prevent the filter from dropping out in the fuel tank. Further, since the metal filter is provided integrally with the metal pipe, it is not necessary to retrofit the filter member, and the assembly workability is improved.

  The metal pipe may have a horizontal portion that is above the upper liquid level and has a horizontal axial direction, and the opening may be formed in an upper portion of the horizontal portion.

  In this case, since there is an opening in the upper part of the horizontal portion of the metal pipe, the evaporative gas returned by buoyancy through the return pipe can be smoothly discharged from the opening into the fuel tank through the metal filter. . In addition, since the opening is provided in the horizontal part of the metal pipe, even when the opening formation position is limited to the upper part of the pipe, a large area of the metal filter can be secured in the horizontal direction, and the pressure in the return pipe increases. It is possible to improve the degassing property by suppressing the above.

  The metal filter may be formed by brazing a metal mesh to the opening of the metal pipe.

  If it does in this way, since the metal mesh is being fixed by brazing, there is no possibility of damaging the metal mesh by a spark during the manufacturing operation like welding, and the manufacturing efficiency can be improved.

  The bottom wall portion of the fuel tank may be at least partially raised and have a bottom shape, and the metal pipe may be fixed to the bottom wall portion.

  If it does in this way, since a return pipe is connected to the raised bottom-like bottom wall part of a fuel tank, compared with the case where it is connected to the side wall part of a fuel tank, the appearance becomes good. Further, the lead pipe lead-out location is located above the lowermost surface of the fuel tank, and the lead-out location is covered so that it cannot be seen from the outside in a side view, so that the design is further improved.

  As is apparent from the above description, according to the present invention, the metal pipe is fixed to the metal fuel tank, and the metal filter is integrally attached to the opening of the metal pipe. Also in the process, the filter can be prevented from falling off in the fuel tank.

  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 frame 10 constituting the skeleton of the vehicle body extends rearward from the head pipe 8. A front end 11 a of a swing arm 11 is pivotally supported on the 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 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 41 (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. A known fuel injection pump 22 that integrates the functions of a fuel pump, a regulator, and an injector is attached to the throttle body 18. 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 41 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). A return pipe 27 is branchedly connected to the circulation pipe 26 to return the evaporated gas V generated in the fuel injection pump 22 and the like and floating in the liquid of the circulation pipe 26 to the fuel tank 12. It protrudes into the air layer of the fuel tank 12 (space when full).

  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 and the like floats inside the circulation pipe 26 and the return pipe 27 and is returned to the fuel tank 12.

  FIG. 3 is an enlarged left side view of the fuel supply system of the motorcycle 1 shown in FIG. 4 is a partial cross-sectional rear view of the fuel supply system of the motorcycle 1 shown in FIG. 1 as viewed from the rear. As shown in FIG. 4, the fuel tank 12 has a metal inner panel 38 that mainly forms a bottom wall portion and a metal outer panel 39 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 38 has a raised bottom shape, and the first bottom wall portion 38a which is the lowermost surface, the second bottom wall portion 38b of the raised bottom portion, the first bottom wall portion 38a and the second bottom wall portion 38b are continuous. And an inclined inner wall portion 38c. A fuel tap 20 is attached to the first bottom wall portion 38 a of the fuel tank 12.

  As shown in FIGS. 3 and 4, a filter device 21 is connected to the fuel tap 20 via a first feed pipe 24, and the filter device 21 is behind the fuel tap 20 and directly below the intake duct 19. Has been placed. 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 above the throttle body 18 behind the fuel tap 20. 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 injection pump from the fuel tap 20 through the filter device 21 due to the water head pressure of the fuel in the fuel tank 12. The fuel is supplied to 22 at a low pressure.

  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 30 that is directly connected to the fuel injection pump 22, a separator 31 that is connected to the first pipe 30 and branches the output side in two directions up and down, and an upper end portion at a branched lower portion of the separator 31. Are connected to the second pipe 32. The lower end of the second pipe 32 is connected to the filter device 21. The separator 31 is fixed by a fixing member 32 to a main frame (not shown) that passes through a raised bottom space below the bottom wall portion 38 b of the fuel tank 12.

  A lower end portion of the return pipe 27 is connected to the branched upper portion of the separator 31, and the upper end portion of the return pipe 27 protrudes into the air layer above the upper limit liquid level FL of the fuel tank 12. The return pipe 27 includes a flexible pipe 33 such as a rubber tube whose lower end portion is directly connected to the separator 31, and a lower end portion connected to the upper end portion of the flexible pipe 33 so as to be previously soldered to the second bottom wall portion 38 b of the fuel tank 12. And a metal pipe 34 fixed by penetration. The lower end portion of the flexible pipe 33 is fastened to the upper portion of the separator 31 by a clamp member 35, and the upper end portion of the flexible pipe 33 is fastened to the lower end portion of the metal pipe 34 by a clamp member 36.

  Further, a protective member 37 for protecting the flexible pipe 33 from contact with the main frame (not shown) or the like disposed in the vicinity is covered at an intermediate portion of the flexible pipe 33. Further, the lead-out point (the connection point between the metal pipe 34 and the flexible pipe 33) from the second bottom wall portion 38b of the metal pipe 34, the connection point between the flexible pipe 33 and the separator 31, etc. It is located above the first bottom wall 38a, which is the lower surface, and is covered with the fuel tank 12 in a side view. Therefore, these connection parts are hidden so that they cannot be visually recognized from the outside, and the design is good.

  FIG. 5 is a left side view of the return pipe 27 of the motorcycle 1 shown in FIG. As shown in FIG. 5, the metal pipe 34 of the return pipe 27 includes a vertical portion 34a that is fixed to the second bottom wall portion 38b of the fuel tank 12 by brazing or the like, and a front portion continuously from the upper end of the vertical portion 34a. And a horizontal portion 34b protruding toward the surface. The horizontal portion 34b is arranged so that the axial direction is substantially horizontal above the upper limit liquid level FL, and the front end portion 34d is closed. An opening 34c is formed in the upper half of the required portion of the horizontal portion 34b, and the metal mesh 40 is integrally attached to the opening 34c by brazing.

  With the above configuration, the metal pipe 34 is fixed to the metal fuel tank 12, and the metal filter 40 is integrally attached to the opening 34 c of the metal pipe 34. It is possible to prevent the filter 40 from falling off in the fuel tank 12 in the heating process. Further, since the metal filter 40 is provided integrally with the metal pipe 34, it is not necessary to retrofit the filter member, and the assembly workability is improved.

  Furthermore, since there is an opening 34c in the upper part of the horizontal portion 34b of the metal pipe 34, the evaporated gas V returned by buoyancy through the metal pipe 34 is smoothly discharged from the opening 34c into the fuel tank 12 through the metal filter 40. can do. Further, since the opening 34c is provided in the horizontal portion 34b of the metal pipe 34, a large area of the metal filter 40 can be secured in the horizontal direction even if the opening forming position is limited to the upper part of the pipe. The pressure increase in the return pipe 27 can be suitably reduced. Furthermore, since the metal mesh 40 is fixed to the metal pipe 34 by brazing, there is no possibility of damaging the metal mesh 40 due to sparks during manufacturing operations like welding, and the manufacturing efficiency can be improved.

  In the above embodiment, the metal mesh 40 is fixed to the metal pipe 34 by brazing, but other fixing methods may be used as long as the metal mesh 40 does not fall off in the heating process. In the above embodiment, an upright single-cylinder engine is illustrated. However, the present invention is not limited to this, and may be, for example, 2 to 4 cylinders, an in-line type, a horizontally opposed type, or a V-type engine. . Furthermore, 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 preventing the filter from falling off in the fuel tank even in the heating process of the metal fuel tank, and the significance of this effect can be demonstrated. -Can be widely applied to large motorcycles.

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 fuel supply system of the motorcycle shown in FIG. 1 is enlarged and displayed. FIG. 2 is a partially sectional rear view of the motorcycle shown in FIG. 1 as viewed from the rear. Fig. 2 is a left side view of a return pipe of the motorcycle shown in Fig. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 12 Fuel tank 21 Filter apparatus 22 Fuel injection pump 26 Circulation pipe 27 Return pipe 34 Metal pipe 34b Horizontal part 34c Opening 40 Metal mesh FL Upper limit liquid level V Evaporative gas

Claims (4)

A fuel tank made of metal, a filter device disposed lower than the fuel tank and filtering fuel from the fuel tank, and a fuel injection pump for injecting fuel that has passed through the filter device into an intake passage to the engine And a return pipe that returns the evaporated gas from the fuel injection pump to the fuel tank,
The return pipe has a metal pipe fixed to the fuel tank in a state of protruding into the air layer above the upper liquid level in the fuel tank,
2. The motorcycle according to claim 1, wherein an opening is provided in the metal pipe above the upper liquid level, and a metal filter is integrally attached to the opening.   2. The motorcycle according to claim 1, wherein the metal pipe has a horizontal portion that is above the upper liquid level and is substantially horizontal in the axial direction, and the opening is formed in an upper portion of the horizontal portion.   The motorcycle according to claim 1 or 2, wherein the metal filter has a metal mesh attached to the opening of the metal pipe by brazing.   The motorcycle according to any one of claims 1 to 3, wherein at least a part of the bottom wall portion of the fuel tank has a raised bottom shape, and the metal pipe is fixed to the bottom wall portion.

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