JP4108954B2 - Motorcycle fuel system layout structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an arrangement structure of a fuel system such as a fuel supply system and a fuel control system of a motorcycle.
[0002]
[Prior art]
In a small motorcycle such as a scooter, a swing unit type engine is used. This swing unit type engine forms an engine unit by integrally connecting an engine crankcase and a speed reducer case, and connects a rear wheel to the speed reducer and swingably attaches to a vehicle body frame via a damper. The front part is pivotally attached to the vehicle body frame via a pivot. As a result, the engine unit can rotate within the angular range centered on the pivot together with the rear wheel, and swings with respect to the vehicle body frame to absorb vibration during traveling.
[0003]
Conventionally, a two-cycle engine equipped with a carburetor has been used as a swing unit engine for such a small motorcycle. However, in order to improve high-precision operation control and exhaust gas emission, a fuel-injected four-cycle engine is used. Is under development.
[0004]
In the intake system of this engine, an air cleaner is provided at the end of the intake passage, and outside air is introduced through the air cleaner. A throttle body constituting a part of the intake passage is connected in the middle of the intake passage. A throttle valve is provided in the throttle body to control the intake air amount. An injector is provided facing the intake passage on the downstream side of the throttle body to inject fuel. The intake air that has been injected with fuel to become an air-fuel mixture passes through the intake manifold and is sucked into the engine combustion chamber via the intake valve at the downstream end of the intake passage.
[0005]
This fuel injection type engine is provided with an injector on the intake passage, and the fuel in the fuel tank is made high by a fuel pump and supplied to the injector through a fuel hose. The fuel hose is made of a hard resin and connects the fuel tank and the injector, and a return pipe branches near the injector and communicates with the fuel tank. A pressure regulator is provided on the return pipe of the fuel hose branch near the injector. The fuel is maintained at a predetermined pressure by a pressure regulator and supplied to the injector, and excess fuel is returned to the fuel tank through a return pipe. Such a fuel piping structure is conventionally used for a fuel injection engine of a four-wheeled vehicle.
[0006]
In order to perform injection control and ignition control according to the operating state of such a fuel injection engine, the coolant temperature, the intake air temperature, the intake air negative pressure, and the like are detected, and these detection signals are sent to the engine control unit (ECU). The ECU controls the drive of the engine according to a predetermined program or map based on these operation state detection signals.
[0007]
[Problems to be solved by the invention]
The fuel system including the fuel supply system such as the fuel tank, the fuel hose and the injector, and the fuel control system such as the coolant temperature sensor for performing the injection control is a space particularly in a motorcycle such as a small scooter. Due to large restrictions, the engine must be compactly arranged around the engine.
[0008]
As a fuel system for such a motorcycle, for example, it is considered that a cylinder of an engine is tilted forward almost to the horizontal and a fuel tank is disposed above the engine to achieve a compact configuration in the vertical direction.
[0009]
However, in the case of a swing unit type engine, since the engine swings in the vertical direction, a clearance from the fuel tank disposed above the engine is necessary, and the capacity of the fuel tank is required for downsizing around the engine. Must be reduced.
[0010]
The present invention has been made in consideration of the above prior art, and an object of the present invention is to provide a fuel system arrangement structure for a motorcycle that can efficiently arrange fuel system parts in a limited space around the engine to obtain a compact configuration. To do.
[0011]
[Means for Solving the Problems]
  In order to achieve the above object, in the present invention,A fuel for a motorcycle in which an engine unit that integrates an engine and a reduction gear connected to a rear wheel is swingably attached to a vehicle body frame, and a fuel tank is disposed above the engine and fixed to the vehicle body frame. The fuel tank has a system arrangement structure in which a concave portion that opens downward, leftward, and rearward is formed on a bottom surface side of the fuel tank, and an injector attached to an intake pipe of the engine is disposed in the concave portion. The fuel hose connecting the injector and the injector is positioned on the opposite side of the recess so as to extend in a direction away from the recess.A fuel system arrangement structure for a motorcycle is provided.
[0012]
According to this configuration, the concave portion is formed on the bottom surface side of the fuel tank above the engine, and the fuel control component attached to the engine side is disposed in the concave portion, so that a compact structure in the vertical direction can be obtained. As a result, the seat position can be lowered and the wheelbase length can be reduced. In addition, fuel system parts can be centrally laid out to reduce the cost of the vehicle by making it compact and reducing piping.
[0014]
  Also,According to this configuration, the swing unit type fuel injection engine is provided in the engine.InjectorBy disposing the fuel tank so as to be located in the recess of the fuel tank, it is possible to swing within the height range of the recess of the fuel tank when the engine swings. Forming a compact structure is obtained.
[0015]
  In a preferred configuration example,The fuel hose extends downward and leftward from the injector and is spaced from the recess.
  In a further preferred configuration example, the injector is characterized in that it overlaps the fuel tank in a plan view and is positioned on the left side of the rear portion of the fuel tank.
  In a further preferred configuration example, a fuel pump is disposed in the fuel tank at a position other than the portion where the concave portion is formed.
[0016]
According to this configuration, an in-tank type fuel supply structure is formed by providing the fuel pump in a deep portion other than the concave portion where the fuel tank becomes shallow, thereby further simplifying the structure around the engine.
[0017]
  In a further preferred configuration example, the fuel pumpAnd the injectorIt is characterized by being arranged at a position almost lined up in the vehicle width direction.
[0018]
  According to this configuration, an in-tank fuel pump andWith the injectorSince they are arranged side by side in the vehicle width direction (at substantially the same position in the front-rear direction), a compact structure can be obtained in the front-rear direction of the vehicle body.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an external view of a small motorcycle to which the present invention is applied.
[0020]
The vehicle body 1 has a handle 2 at the front, and the handle 2 is connected to a front wheel 5 via a steering shaft 4 through which a head pipe 3 is inserted. A body frame 6 is coupled to the head pipe 3. The body frame 6 forms a frame structure of the entire vehicle body. The front part of the vehicle body is covered with a cowling 7. The vehicle body 1 is covered with a vehicle body cover 8 from the outside of the vehicle body frame 6. A seat 9 is provided at the center of the vehicle body, a fuel tank 10 is provided on the lower side, and a helmet box (case) 11 is provided on the rear side. The fuel tank 10 supplies fuel to an injector (not shown) via a fuel hose (not shown). One end of the breather hose 12 is connected to the upper portion of the fuel tank 10, and the other end is connected to the canister 13. The canister 13 is connected to an intake system (for example, a throttle body) via a purge hose 14. A throttle wire 15 is attached to a throttle grip (or lever) of a right handle portion (not shown) and is connected to a throttle valve of an intake system. Similarly, a brake cable 16 is attached to a brake lever (not shown) of the handle portion and is connected to a brake cam shaft 18 of the rear wheel 17.
[0021]
An engine unit 19 is attached to the vehicle body frame 6 at the center of the vehicle body. The engine unit 19 includes an engine (not shown) and a speed reducer 24 integrally coupled to a crankcase (not shown). The engine unit 19 is suspended via an engine bracket 20 so as to be rotatable around a pivot 22 with respect to a lower body frame member 21 constituting a part of the body frame 6. The rear wheel 17 is connected to the rear portion of the engine unit 19 and the lower end of the damper 23 is pivoted. The upper end of the damper 23 is pivotally attached to a rear body frame (not shown) constituting a part of the body frame 6. As a result, the engine unit 19 can swing around the pivot 22 together with the rear wheel 17 to form a swing unit type engine.
[0022]
An air cleaner 25 is provided above the speed reducer 24. An outside air intake opening 25 a is opened at the front of the air cleaner 25, and a dustproof cover 26 made of rubber or resin is provided inside the vehicle body cover 8 so as to cover the opening. Reference numeral 27 denotes a stand, and 28 denotes a kick lever.
[0023]
2 and 3 are a side view and a plan view, respectively, showing a main part of the motorcycle equipped with the fuel injection engine according to the present invention. FIG. 4 is an enlarged view of the intake system portion.
[0024]
An engine 29 is provided below the fuel tank 10. The engine 29 is a four-cycle single cylinder engine having a fuel injection injector. A crankcase (not shown) of the engine 29 is integrally coupled with a speed reducer 24 composed of, for example, a V-belt type continuously variable reduction mechanism, and constitutes an engine unit 19 of a swing unit engine type as a whole. A duct 30 is connected to the front portion of the speed reducer 24, and outside air is sucked from the open end 30a and supplied to the speed reducer 5 to cool the inside. A rear output shaft (not shown) of the speed reducer 24 is connected to the axle of the rear wheel 17.
[0025]
An engine bracket 20 is integrally coupled to a front portion of the engine unit 19 of the swing unit engine type. A link plate 32 is pivotally attached to the engine bracket 20 via a shaft 31. The link plate 32 is rotatably attached to the lower body frame member 21 via the pivot 22.
[0026]
  A damper (shock absorber) 23 is provided at the rear of the engine unit 19. The upper end 33 of the damper 23 is pivotally attached to the rear body frame member 34, and the lower end 35 is pivotally attached to a bracket 36 at the rear end portion of the engine unit 19. As a result, the engine unit 19 is mounted so as to be swingable with respect to the vehicle body frame around the pivot 22 on the front side. As shown in FIG. 4, the cylinder 37 of the engine 29 is tilted forward almost to the horizontal. The crankshaft 38 is used together with the shaft 31 of the engine bracket 20 (FIG. 2) around the pivot 22 described above.InSwings as indicated by arrow D.
[0027]
The intake side of the engine 29 is provided with an intake manifold 39 communicating with an intake port (not shown) of the cylinder head and an intake pipe 40 (FIGS. 3 and 4) connected thereto, and an exhaust pipe 41 (FIG. 3) is provided on the exhaust side. ) Is connected. The intake pipe 40 is a bent elbow-like intake pipe. As shown in FIG. 4, the flange 43 is abutted against each other via a resin heat insulating material 42 and is fixed by two bolts 44. Reference numeral 45 denotes a valve cam maintenance cover. The engine 29 is provided with a water temperature sensor 46 (FIGS. 3 and 4). The detection output signal of the water temperature sensor 46 is sent to the engine control unit 47 (FIG. 3) via the water temperature signal cable 89 (FIG. 3) and the wire harness 72. Further, a detection signal cable (not shown) of an intake air temperature sensor and an intake pressure sensor, which will be described later, is connected to the engine control unit 47 via a wire harness 72, and the throttle valve (not shown) is controlled to open and close based on these detection data. To do.
[0028]
A throttle body 48 is connected to the intake manifold 39 via the bent elbow-shaped intake pipe 40 described above. The throttle body 48 is connected to the air cleaner 25 via a joint 49. An injector 50 is attached to the intake pipe 40.
[0029]
A throttle valve (not shown) is mounted in the throttle body 48, and a diaphragm type suction piston 51 is mounted on the upstream side thereof. As will be described later, the suction piston 51 has a diaphragm chamber 52 provided on the upper side of the throttle body 48, and an air inlet (atmosphere open end) 54 of an air passage 53 for introducing the air into the diaphragm chamber 52 is a throttle. Provided on the lower side of the body 48. A throttle wire 15 connected to a throttle lever (not shown) or a throttle grip is connected to a valve shaft of the throttle valve via a link 55.
[0030]
The air intake opening 25a at the front of the air cleaner 25 is covered with a dustproof cover 26 (a chain line in FIG. 1) made of rubber or resin. A vehicle body cover is further attached to the outside of the dust cover 26. The air intake 54 of the suction piston 51 opens inside the dust cover 26.
[0031]
Adjacent to the suction piston 51, the throttle body 48 is provided with a heater-type wax type auto choke 56 and an intake pressure sensor 57 (FIG. 3). The auto choke 56 opens and closes a bypass pipe (not shown) that communicates the upstream side and the downstream side of the throttle valve. The intake pressure sensor 57 communicates with the intake manifold 39 or the intake pipe 40 via a negative pressure hose 58 (FIG. 4). An intake air temperature sensor 59 (FIG. 3) is provided in the air cleaner 25.
[0032]
The intake pressure sensor 57 may be provided in the vicinity of the intake manifold. Further, a throttle position sensor (not shown) may be provided on the valve shaft of the throttle valve opposite to the link 55. In this case, the auto choke 56 is provided upstream of the throttle valve so as not to interfere with the throttle position sensor.
[0033]
The front lower portion of the fuel tank 10 is fixed to the left and right vehicle body frame members 61 via the bracket 60. A fuel hose 62 is pulled out from the rear of the fuel tank 10 to supply fuel to the injector 50. The fuel hose 62 is fixed to the rear body frame member 34 via a stay 63 (FIGS. 2 and 4). 64 (FIG. 2) is an overflow pipe. 65 (FIG. 3) is a battery, and 66 (FIG. 3) is a cooling water recovery tank. As shown in FIG. 3, a secondary air introduction system 86 for purifying exhaust gas is provided on the right side of the center of the vehicle body. The secondary air introduction system 86 communicates with the intake manifold via a negative pressure hose 87, and supplies outside air to a catalyst (not shown) via an air hose 88 in accordance with the intake negative pressure to reburn the exhaust gas.
[0034]
As shown in FIG. 2, a blow-by gas hose 90 is connected to the air cleaner 25. The blow-by gas hose 90 communicates with a cam chain chamber (not shown) that leads to a crankcase (not shown) of the engine 29, and prevents oil seal drop and loss horsepower due to a pressure increase in the crankcase of the engine. This blow-by gas hose 90 is connected to the clean side after passing through the element in the air cleaner, and the blow-by gas is again introduced into the combustion chamber.
[0035]
FIG. 5 is a configuration diagram of a fuel tank according to the present invention.
Fuel 107 is accommodated in the fuel tank 10. Reference numeral 108 denotes a float type fuel gauge. A fuel pump 109 is provided in the fuel tank 10 and sucks up the fuel 107 through the filter 110. The fuel pump 109 constitutes an in-tank type pump unit 112 together with the pressure regulator 111, and is fixed to the fuel tank 10 by a plurality of bolts 114 through a disk-shaped lid 113. A coupler 115 for electrical wiring is provided on the upper surface side of the lid 113. A rubber fuel hose 62 is fitted into the discharge port 116 of the pump unit 112. The fuel tank 10 is formed with a recess 117 having a reduced height on the rear side. The pump unit 112 is attached to the recess 117.
[0036]
6 and 7 are a top view and a side view, respectively, of the fuel tank portion of the motorcycle shown in FIG.
[0037]
As shown in FIG. 6, the left and right of the front portion of the fuel tank 10 are fixed to the vehicle body frame member 61 via the bracket 60, and the rear portion is fixed to the left and right rear vehicle body frame members 34 by bolts 119 via the tank flange 118. Fixed to. A recess 117 is formed in the rear portion of the fuel tank 10 and has a narrow right side. The in-tank pump unit 112 is fixed to the right portion of the recess 117 with six bolts 114 through a cap 113. The coupler 115 on the upper surface of the cap 113 is connected to the engine control unit 47 (FIG. 3) via the cable 120. The fuel hose 62 is bent downward through the left portion (narrow portion) of the recess 117 and connected to the injector 50 (see FIG. 7). The fuel hose 62 is held by a stay 63 fixed to the rear body frame member 34 (described later). A suction piston 51 and a battery 65 are disposed behind the fuel tank 10.
[0038]
A fuel inlet 122 surrounded by a filler cover 121 is provided at the front of the fuel tank 10 and is closed with a cap 123. The breather hose 12 taken out from the upper part of the fuel tank 10 communicates with the canister 13 via a rollover valve 124 (see FIG. 7). The canister 13 communicates with the throttle body 48 via the purge hose 14. An overflow pipe 64 is connected to the filler cover 121.
[0039]
The fuel hose 62 is held by a grommet 153 (see FIG. 10 described later), the periphery thereof is held by a holder 150, and the end of the holder is fixed to the stay 63 by a bolt 149.
[0040]
  The fuel piping system of the motorcycle of this embodiment is a returnless piping. As shown in FIG. 7, only the fuel hose 62 is connected to the injector 50, and the return piping is not connected. Therefore, the suction piston51The piping system can be efficiently arranged in a narrow space around the engine behind the fuel tank 10 narrowed by the battery 65 or the like. The fuel hose 62 is made of a soft rubber having a high flexibility.
[0041]
The fuel hose 62 is preferably composed of a molded hose made of high-pressure rubber. By molding the high-pressure rubber hose material, the layout of the fuel hose 62 can be determined in accordance with a preset component arrangement, and the fuel hose 62 can be formed in the shape of the layout. As a result, when the fuel hose is disposed, the initial load is not increased by hitting other components, and external force is not applied or rubbed and deteriorated with the swing. In addition, the looseness of the connecting part due to the elasticity of the fuel hose and the occurrence of twisting due to unreasonable mounting are suppressed, and clearance with other parts is secured in a place where the parts are confined in a narrow space, and a compact configuration ensures reliability. High connection is achieved.
[0042]
  FIG. 8 is a side view of the entire body frame of the motorcycle shown in FIG. 1, and FIG. 9 is a top view of the main part thereof. Body frame138The center down tube 139 fixed to the head pipe 3 at the front of the vehicle body, the front vehicle body frame members 140 provided on the left and right sides of the down tube 139, and the elbow frame 145 to the left and right front vehicle body frame members 140 The rear vehicle body frame member 34 is continuous with the vehicle body. A cross member 142 is provided between the left and right rear body frame members 34. A battery bracket 143 is fixed in the middle of the cross member 142, and a battery 65 (see FIGS. 3 and 6) is mounted. A damper bracket 144 is fixed to a rear lower side of the rear body frame member 34 on the left side of the vehicle body, and a damper mounting hole 33a is provided to which an upper end 33 (see FIG. 2) of the damper 23 (see FIG. 2) is pivotally attached.
[0043]
A vehicle body frame member 61 is provided between the intermediate portion of the down tube 139 and the left and right rear vehicle body frame members 34 obliquely behind the down tube 139, and the bracket 60 is fixed to the vehicle body frame member 61. A support member 141 is provided by connecting the upper end portions of the left and right brackets 60. A tank flange 118 (see FIGS. 6 and 7) at the front of the fuel tank is supported on the support member 141, and is fixed by two bolts 148 (FIG. 8) through the bolt holes 146. The left and right rear body frame members 34 are each fixed with a stay 63 having a U-shaped cross section. The left and right rear portions of the tank flange 118 are respectively supported on the left and right stays 63 and are fixed by bolts 119 (see FIGS. 6 and 7) through the bolt holes 147.
[0044]
A notch 118 a is formed in the rear left corner of the tank flange 118. A fuel hose 62 is disposed through the notch 118a. The fuel hose 62 is clamped by a holder (FIG. 6) and fixedly held on the stay 63 by a bolt 149.
[0045]
FIG. 10 is a perspective view of the fuel tank 10.
The fuel tank 10 has an upper and lower divided structure, and has a flange around each of the upper and lower divided bodies, and the flanges are joined together to form a tank flange 118. As described above, the recess 117 is formed in the rear portion of the upper divided body of the fuel tank 10 (the portion above the tank flange 118). The pump unit 112 is attached to the right side portion of the recess 117. The depth (height from the flange surface) of the recess 117 is determined so that the tops of the components such as the coupler 115 protruding on the upper surface of the pump unit 112 do not protrude from the upper surface of the fuel tank 10. The depth of the dent 117 is approximately the same as or slightly higher than the flange surface, depending on the height of the part.
[0046]
The fuel hose 62 is inserted into the discharge port 116 of the pump unit 112 and fixed with a band 152. The fuel hose 62 made of high-pressure rubber molded as described above is disposed across the recess 117, and is disposed in the lower portion of the fuel tank through the notch 118a of the flange 118. The fuel hose 62 is disposed in the injector 50 (see FIG. 7). Connected. A grommet 153 is attached to the fuel hose 62 adjacent to the notch 118a, the periphery thereof is held by a holder (indicated by reference numeral 150 in FIG. 6), and the end of the holder is secured by a bolt 149 (see FIGS. 8 and 8). 9) (see FIG. 6). The fuel hose 62 on the pump unit 112 side from the grommet 153 becomes a fixed hose portion 62a fixed rigidly to the vehicle body frame 138 (FIG. 8) to which the fuel tank 10 is fixed. The fuel hose 62 below the grommet 153 becomes a swing hose portion 62b that swings together with the injector.
[0047]
A recess 154 is formed in the left side portion from the vicinity of the rear center of the bottom surface of the fuel tank 10. In the recess 154, the injector 50 (FIG. 7) and the water temperature sensor 46 (FIG. 3) are arranged with a clearance by swinging. 151 is a breather pipe to which the breather hose 12 is connected.
[0048]
FIG. 11 is a plan view of a fuel tank according to an embodiment of the present invention, and FIG. 12 is a rear view thereof.
As described above, the in-tank pump unit 112 is installed in the fuel tank 10. The in-tank pump unit 112 is provided on the right side of the rear portion of the fuel tank 10, and a concave portion 154 is formed on the bottom surface side (a portion below the tank flange 118) of the fuel tank 10 at a position avoiding this. An injector 50 and a water temperature sensor 46 are provided in the recess 154. The fuel pump 109, the injector 50, and the water temperature sensor 46 are arranged side by side substantially side by side in the vehicle width direction.
[0049]
In order to compensate for the reduction in tank capacity due to the provision of the recess 117 and the recess 154 in the fuel tank 10, the left and right side surfaces of the tank are inflated as much as possible toward the body cover (not shown) to form a smooth convex curved surface. Is desirable.
[0050]
A fuel hose 62 is connected to the injector 50. A blow-by gas hose 90 is connected in the vicinity of the injector 50. The blow-by gas hose 90 is actually connected so as to communicate with the intake manifold 39. The other end of the blow-by gas hose 90 is connected to the clean side of the air cleaner 25 (FIG. 3). The water temperature sensor 46 is attached to a cylinder head (not shown), and is connected to the engine control unit 47 (FIG. 3) via a water temperature signal cable 89 in the wire harness 72.
[0051]
The injector 50 is provided with an electrode 157 for driving a solenoid, and is connected to the engine control unit 47 (FIG. 3) via an electric cable 156 in the wire harness 72.
[0052]
【The invention's effect】
  As described above, in the present invention, a recess is formed on the bottom surface side of the fuel tank above the engine, and the recess is attached to the engine side in the recess.InjectorIs arranged, a compact structure can be obtained in the vertical direction. As a result, the seat position can be lowered and the wheelbase length can be reduced. In addition, fuel system parts can be centrally laid out to reduce the cost of the vehicle by making it compact and reducing piping.
[0053]
  The engine is a fuel injection engine having an injector facing the intake passage, and the engine and a speed reducer connected to the rear wheel are integrated to form an engine unit,InjectorAccording to the configuration disposed in the recess, in the swing unit type fuel injection engine, the engine is provided in the engine.InjectorBy disposing the fuel tank so as to be located in the recess of the fuel tank, it is possible to swing within the height range of the recess of the fuel tank when the engine swings. Forming a compact structure is obtained.
[0054]
Furthermore, according to the configuration in which the fuel pump is disposed in the fuel tank at a position other than the portion where the concave portion is formed, the in-tank type is provided by providing the fuel pump in a deep portion other than the concave portion where the fuel tank becomes shallow. A fuel supply structure is formed, which further simplifies the structure around the engine.
[0055]
  Furthermore, the fuel pumpAnd the injectorAccording to the configuration arranged almost in the vehicle width direction, the in-tank type fuel pump andWith injectorSince they are arranged almost horizontally, a compact structure can be obtained in the longitudinal direction of the vehicle body.
[Brief description of the drawings]
FIG. 1 is an external view of a small motorcycle according to the present invention.
FIG. 2 is a side view of the main part of the motorcycle shown in FIG.
Fig. 3 is a plan view of the main part of the motorcycle shown in Fig. 1;
4 is a configuration diagram of an engine portion of the motorcycle shown in FIG. 1. FIG.
FIG. 5 is a configuration diagram of a fuel tank according to the present invention.
6 is a top view of a fuel tank portion of the motorcycle of FIG. 1. FIG.
7 is a side view of the fuel tank portion of FIG.
8 is an overall side view of the body frame of the motorcycle shown in FIG. 1. FIG.
FIG. 9 is a top view of the main part of the vehicle body frame of FIG.
FIG. 10 is a perspective view of a fuel tank according to the present invention.
FIG. 11 is a plan configuration diagram around the fuel tank of the present invention.
12 is a rear view of the fuel tank of FIG.
[Explanation of symbols]
1: body, 2: handle, 3: head pipe, 4: steering shaft.
5: front wheel, 6: body frame, 7: cowling, 8: body cover.
9: Seat, 10: Fuel tank, 11: Helmet box.
12: Breather hose, 13: Canister, 14: Purge hose.
15: Throttle wire, 16: Brake cable, 17: Rear wheel.
18: Brake camshaft, 19: Engine unit.
20: engine bracket, 21: lower body frame member, 22: pivot.
23: Damper, 24: Reducer, 25: Air cleaner l.
25a: Opening for air intake, 26: Dust-proof cover, 27: Stand.
28: kick lever, 29: engine, 30: duct, 30a: open end.
31: shaft, 32: link plate, 33: upper end, 33a: damper mounting hole.
34: rear body frame member, 35: lower end, 36: bracket.
37: Cylinder, 38: Crankshaft, 39: Intake manifold, 40: Intake pipe.
41: exhaust pipe, 42: heat insulating material, 43: flange, 44: bolt.
45: Maintenance cover, 46: Water temperature sensor, 47: Engine control unit.
48: throttle body, 49: joint, 49a: joint end.
50: Injector, 51: Suction piston, 52: Diaphragm chamber.
53: Air passage, 54: Air intake, 55: Link, 56: Auto choke.
57: Intake pressure sensor, 58: Negative pressure hose, 59: Intake temperature sensor.
60: bracket, 61: body frame member, 62: fuel hose.
62a: fixed hose part, 62b: swinging hose part, 63: stay.
64: overflow pipe, 65: battery.
66: Recovery tank, 72: Wire harness, 74: Throttle valve.
78: rubber joint, 78a: recess, 79: piston.
80: Diaphragm, 81: First chamber, 82: Second chamber, 83: Negative pressure port.
84: Spring, 86: Secondary air introduction system.
87: Negative pressure hose, 88: Air hose, 89: Water temperature signal cable.
90: Blow-by gas hose.
107: fuel, 108: float type fuel gauge, 109: fuel pump.
110: filter, 111: pressure regulator, 112: pump unit.
113: Lid, 114: Bolt, 115: Coupler, 116: Discharge port.
117: hollow part, 118: tank flange, 118a: notch.
119: Bolt, 120: Cable, 121: Filler cover.
122: Fuel inlet, 123: Cap, 124: Rollover valve.
138: body frame, 139: down tube.
140: front body frame member, 141: support member, 142: cross member.
143: Battery bracket, 144: Damper bracket.
145: Elbow frame, 146: Bolt, 147: Bolt hole.
148, 149: bolt, 150: holder, 151: breather pipe.
152: Band, 153: Grommet, 154: Recess.
156: Electric cable, 157: Electrode.

Claims (5)

A fuel for a motorcycle in which an engine unit that integrates an engine and a reduction gear connected to a rear wheel is swingably attached to a vehicle body frame, and a fuel tank is disposed above the engine and fixed to the vehicle body frame. System layout structure,
Forming a recess on the bottom side of the fuel tank that opens downward, leftward and rearward;
An injector mounted on the intake pipe of the engine is disposed in the recess,
A fuel system arrangement for a motorcycle , wherein a connecting portion of the fuel hose connecting the fuel tank and the injector is positioned on the side opposite to the recess so as to extend in a direction away from the recess. Construction. 2. The fuel system arrangement structure for a motorcycle according to claim 1, wherein the fuel hose extends downward and leftward from the injector and is separated from the recess. 3. 2. The fuel system arrangement structure for a motorcycle according to claim 1, wherein the injector overlaps with the fuel tank in a plan view and is positioned on a left side of a rear portion of the fuel tank. 3. The fuel system arrangement structure for a motorcycle according to claim 1 , wherein a fuel pump is arranged in a fuel tank at a position other than the portion where the recess is formed. The fuel system arrangement structure for a motorcycle according to claim 4 , wherein the fuel pump and the injector are arranged at a position substantially aligned in the vehicle width direction.

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