JP2003129912A - Fuel system and pump injector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel system and a pump injector, which can eliminate a problem of an arrangement space and heighten a degree of freedom of arrangement by miniaturizing the device, and which can prevent bubbles, so-called vapor gas mixed in fuel, from staying in a fuel feed piping and a return piping. SOLUTION: A fuel pump and an injection nozzle for fuel injection are integrated to constitute a small pump injector 126. At least one of a fuel feed piping 127 and a return piping 128 linked with the pump injector 126 is introduced in an approximately horizontal direction, so as to facilitate suction, separation and exhaust of the vapor gas mixed in the fuel. The fuel feed piping 127 and the return piping 128 may have the inside diameter for smoothly transferring the vapor gas generated in the piping through the piping by a buoyancy. A small auxiliary pump and a filter may be installed in the fuel feed piping 127. Because low pressure fuel and vapor gas pass through the fuel feed piping 127 and the return piping 128, a flexible pipe made of rubber and the like can be used for facilitating the layout.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel injection system (fu
In particular, regarding the fuel system and pump / injector of an el injection system), the miniaturization eliminates the problem of the arrangement space and enhances the freedom of layout. Furthermore, the bubbles containing the fuel mixed with the fuel, so-called The present invention relates to a fuel device and a pump / injector capable of preventing vapor gas from accumulating in a fuel feed pipe or a return pipe and improving starting and operating performance.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional fuel injection type fuel device, in which fuel contained in a fuel tank 1 is a fuel feed pipe 2 and a fuel filter 3 provided in the middle of the fuel feed pipe 2. And is supplied to the fuel pump 4. The fuel pressurized by the fuel pump 4 is supplied to the injector 6 through the discharge pipe 4. The vapor gas existing in the fuel feed pipe 2, the fuel filter 4, and the fuel pump 4 at the time of initial and fuel exhaustion is returned to the fuel tank 1 through the air vent pipes 7 and 8 which are return pipes by supplying fuel to the fuel tank 1. . Further, the fuel pool chamber 9 provided in the middle of the air vent pipe 8 prevents the air from being mixed into the fuel, so that the fuel with the vapor gas mixed therein is not supplied to the injector 6. This type of fuel system is disclosed in Japanese Utility Model Publication No. 61-32567.

[0003]

In the conventional fuel system, the fuel pump and the injector are constructed separately, and they are connected by a metal discharge pipe capable of feeding high-pressure fuel. The number of parts is large and the cost is high. Also,
The entire structure is large, and a space for arranging the fuel pump and injectors and a space for arranging the discharge pipe between them are required.Metal discharge pipes are difficult to lay out. It is disadvantageous when applied to vehicles such as motorcycles and motorbikes.

Further, the vapor gas is mixed with the fuel when the pressure is reduced by suctioning the fuel from the fuel tank or at a high temperature. A part of the mixed vapor gas is discharged through the return pipe, but the vapor gas left without being discharged is retained in the fuel feed pipe and the return pipe, hinders smooth fuel supply, and makes it difficult to start the engine. Further, when the vapor gas is supplied to the fuel pump, the efficiency of the fuel pump is reduced, the fuel metering accuracy is reduced, and a fixed amount of fuel cannot be supplied to the injector.

The object of the present invention is to reduce the size of a fuel injection type fuel device by eliminating the problem of the arrangement space and increasing the freedom of layout. It is to prevent the vapor gas mixed in the fuel from being satisfactorily separated and discharged by preventing it from staying in the pipe.

[0006]

In order to solve the above-mentioned problems, the present invention provides a pump injector in which a fuel pump for fuel injection and an injection nozzle are integrated, and a fuel is supplied from a fuel tank to the pump injector. And a return pipe for returning excess fuel and vapor gas from the pump / injector to the fuel tank, and at least one of the fuel feed pipe and the return pipe is substantially separated from the pump / injector. The first feature lies in the point derived in the horizontal direction.

The present invention has a second feature in that the pump injector is arranged with its axis inclined from the vertical direction, and the fuel feed pipe is led out from the lower side of the pump injector. The present invention has a third feature in that an auxiliary pump is provided in the fuel feed pipe. Further, the present invention has a fourth feature in that a filter is further provided in the fuel feed pipe. Further, the present invention has a fifth characteristic in that the pump injector is located at a position lower than the fuel tank.

A sixth feature of the present invention is that at least one of the fuel feed pipe and the return pipe has an inner diameter equal to or larger than an inner diameter at which vapor gas generated in the pipe can smoothly move in the pipe due to its buoyancy. is there. The seventh aspect of the present invention is that the fuel feed device and the return pipe are flexible pipes. The eighth feature of the present invention is that the flexible pipe is a rubber pipe.

A ninth feature of the present invention is that the open end of the return pipe is exposed at a position above the fuel surface in the fuel tank. A tenth feature of the present invention is that a filter is provided to prevent foreign matter such as dust from entering through the open end of the return pipe. The present invention has an eleventh feature in that a check valve is provided at the open end of the return pipe. The present invention has a twelfth feature in that the fuel system is applied to a motorcycle. Further, the present invention has a thirteenth feature in that the fuel feed pipe and the return pipe are arranged along an underbone frame.

Further, the present invention is a pump injector in which a fuel pump and an injection nozzle are integrated with each other, and includes a fuel intake port, a supply port for supplying internal fuel to the fuel pump, and an internal part provided at an upper part. A sub-tank having a discharge port for discharging vapor gas, a fuel pump concentrically provided in the sub-tank, for injecting fuel supplied from the sub-tank from an injector and discharging surplus fuel from a return port, and the fuel pump. A fourteenth feature is that it comprises an injection nozzle for injecting pressurized fuel. The present invention is a pump injector in which a fuel pump and an injection nozzle are integrated, and has a fifteenth feature in that a fuel pump is provided outside the sub tank.
Furthermore, the 16th feature of the present invention is that the discharge pipe connected to the discharge port of the sub-tank is oriented in the same direction as the flow direction of the surplus fuel returned from the return port of the fuel pump.

According to the first to sixteenth features, the fuel device can be downsized, the problem of the arrangement space can be eliminated, and the degree of freedom of layout can be increased.
Further, according to the first to thirteenth features, it is possible to prevent the vapor gas mixed in the fuel from staying in the fuel feed pipe and the return pipe, and it is possible to favorably separate and discharge the vapor gas mixed in the fuel.

Further, according to the second feature, it is possible to effectively utilize the height difference between the fuel tank and the pump / injector, and it is possible to prevent vapor gas mixed in the fuel from accumulating in the fuel feed pipe or the return pipe. It can be prevented more effectively. Further, according to the third feature, it is possible to compensate for the decrease in suction force that accompanies the miniaturization of the pump / injector, and it is possible to supply fuel to the pump / injector at a position higher than the fuel tank without any trouble. Further, according to the fourth feature, it is possible to prevent foreign matter generated from the auxiliary pump from entering the pump / injector.

Further, according to the sixth feature, it is possible to prevent the vapor gas from staying in the fuel feed pipe and the return pipe due to surface tension. Moreover, according to the seventh feature, the layout of the pipe can be freely and easily performed. Further, according to the eighth feature, it is possible to reduce the generation of vapor gas due to the heat insulating property of rubber. According to the ninth to eleventh features, it is possible to prevent dust and dirt from entering from the open end of the return pipe. Further, according to the twelfth and thirteenth characteristics, the layout of the motorcycle in the limited arrangement space becomes easy.

According to the fourteenth feature, the concentric structure of the pump / injector makes the operation stable when the vehicle or the like is inclined, and the degree of freedom in arrangement is high because the shape is not directional. According to the fifteenth feature, the capacity of the sub-tank can be increased, the vapor gas can be separated and discharged favorably, and the fuel can be discharged stably. Further, according to the sixteenth feature, the vapor gas in the sub tank can be satisfactorily discharged along with the flow of the surplus fuel.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is premised on the use of a pump / injector in which a fuel pump and an injection nozzle are integrated in order to reduce the size of a fuel injection type fuel device, thereby achieving downsizing and eliminating the problem of arrangement space. , Also increase the freedom of layout.

FIG. 8 is a schematic view showing an example of the pump / injector used in the present invention.
For example, it is an example in which a fuel pump including a solenoid type plunger pump is arranged. The fuel is supplied from the fuel tank to the sub tank 10. In the pump drive unit 11, as schematically shown in FIG. 9, a plunger 18 having a spring 17 moves up and down by energization of a solenoid coil 16 to move from a suction port 12 having a check valve to a fuel pump unit 14. Of the fuel, exhaust of excess fuel from the return port 13 and injection of fuel from the injection nozzle 15.

The injection nozzle 15 is a poppet nozzle equipped with an injection valve that opens and closes in response to pressurization of fuel by a fuel pump. The pump driving unit 11 stores the fuel in the sub tank 10
The fuel is sucked into the fuel pump section 14 from the above, the excess fuel is returned to the fuel tank, and a fixed amount of fuel is injected from the injection nozzle 15. The fuel pump can also be configured by a Wesco pump that sucks and discharges by utilizing rotation.

Excess fuel is returned from the return port 13 to the return pipe 19
Through the fuel tank. The discharge pipe connected to the discharge port above the sub-tank 10 is in the same direction as the return direction of the return pipe 19 and communicates with the return pipe 19. The vapor gas in the sub-tank 10 is sucked by the flow of surplus fuel returned to the fuel tank and discharged to the fuel tank.

FIG. 10 is a schematic view showing another example of the pump injector used in the present invention, which is an example in which a fuel pump is combined with another structure outside the sub-tank 20 in front of the drawing. The pump / injector sucks the fuel supplied from the fuel tank to the sub-tank 20 into the fuel pump section 25 through the suction port 22 by driving the pump driving section 21,
The function of returning the excess fuel to the fuel tank through the return port 23 and the return pipe 24 and injecting a fixed amount of fuel from the injection nozzle 26 is the same as in FIG.

With this construction, the capacity of the sub-tank 20 can be increased, the vapor gas can be separated and discharged satisfactorily, and the fuel can be discharged stably. On the other hand, in the configuration of FIG. 8, the operation is stable when the pump / injector is tilted, and since the shape is not directional, the degree of freedom of arrangement is high.

When a pump / injector in which a fuel pump and an injection nozzle are integrated is used, the suction force decreases with the downsizing of the fuel pump, and low pressure is applied to the fuel feed pipe from the fuel tank to the pump / injector. Since the fuel is supplied, the vapor gas generated in the fuel feed pipe at the time of sucking the fuel from the fuel tank or at a high temperature may stay in the fuel feed pipe and may not be discharged.

Further, there is a possibility that the surplus fuel and vapor gas in the return pipe may not be smoothly returned to the fuel tank. In particular, in a vehicle such as a motorcycle, the fuel tank and the power unit are usually disposed far apart from each other, and the fuel feed pipe and the return pipe are relatively long, which is a serious problem.
The present invention solves the above-mentioned problem of vapor gas by arranging the fuel feed pipe and the return pipe and devising the structure.

FIG. 1 is a configuration diagram showing a first embodiment of the present invention applied to a motorcycle, and a motorcycle 100
Is an underbone frame (main frame) 101 composed of one frame extending in an L-shape or a U-shape from the head pipe to the rear side downward, and a head pipe 102.
And the front fork 1 attached to the head pipe 102
03 and the front wheel 104 attached to the front fork 103
And a pair of left and right side arms 105 coupled to the underbone frame 101, a rear fork 106, a rear wheel 107 and a shock absorber 108 attached to the rear fork 106, a seat 109, and a stand 110. A storage box (luggage box) 111 for storing a helmet or the like is provided below the seat 109.

A power unit is suspended below the underbone frame 101 via brackets 112, 113 and 114. Power unit and bracket 112, 11
3, 114 are connected with bolts. The driving force by the power unit is the crankshaft 11 in the crankcase 115.
6, the rear wheel 107 is driven through a gear (not shown), a drive sprocket 117, and a chain in a chain case 118. The power unit has a kick spindle 119.
Also, a starter motor 120 is attached. Rear fork 10
6 is pivotally supported by a pivot 121 provided on the bracket 114.

The power unit has an air cleaner 122 and an intake pipe 123 arranged in front of the vehicle body, and intakes air through them and exhausts them from a muffler arranged at the rear part of the vehicle body through an exhaust pipe 124. A throttle valve 125 and a pump injector 126 are provided in the middle of the intake pipe 124.
To provide. The pump / injector 33 is connected to a fuel tank 129 arranged above the rear portion of the vehicle body by a fuel feed pipe 127 and a return pipe 128. The fuel feed pipe 127 and the return pipe 128 are arranged along the underbone frame 101, for example. Fuel tank 129
A lid 130 that is a fuel supply port from the outside and a strainer 131 that is a filter on the fuel supply side are provided in the.

The pump / injector 126 is, as shown in FIG. 8 or 10, integrated with a fuel pump and an injection nozzle. Pump / Injector 126
On the other hand, the fuel feed pipe 127 is introduced from a substantially horizontal direction. As shown in the figure, if the pump / injector 126 is arranged with the fuel intake port on the lower side and its axis is tilted from the vertical direction and the fuel feed pipe 127 is introduced from a substantially horizontal direction, the height difference from the fuel tank 129 is effective. Fuel can be supplied to the pump injector 126.

In a vehicle such as a motorcycle, the stand 110 is usually arranged on the left side in the traveling direction and tilts to the left when the vehicle is stopped. It is also advantageous to supply the fuel to the pump / injector 126 at the time of restarting by disposing the fuel feed pipe 127 from a substantially horizontal direction. When the pump / injector 126 is arranged so as to be inclined, the arrangement direction is considered so that the fuel injection direction faces the intake direction of the intake pipe 123.

With this configuration, the fuel feed pipe 127
The vapor gas mixed in the fuel inside is sucked by the pump injector 126 with a small resistance, separated in the pump injector 126, and discharged into the fuel tank 129 through the return pipe 128 together with the surplus fuel. The vapor gas in the fuel feed pipe 127 at a position near the fuel tank 35 returns to the fuel tank 35 by its own buoyancy based on the height difference. In addition, the fuel feed pipe 127
Can be shortened by introducing the pump into the pump injector 126 from a substantially horizontal direction.

As described above, by using the pump injector 126 which is miniaturized by integrating the fuel pump and the injection nozzle, the problem of the space for disposing the fuel device is solved, and the fuel feed pipe 127 is a pump. The vapor gas mixed in the fuel is prevented from staying in the fuel feed pipe 127 by devising the arrangement so that it does not rise near the injector 126 and the height difference from the fuel pump can be effectively used. It can be prevented.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention applied to a motorcycle, and the same reference numerals as those in FIG. 1 are the same or equivalent parts. In this embodiment, unlike the first embodiment, the introduction of the fuel feed pipe 127 from a substantially horizontal direction is not considered, and instead, the filter 133 and the auxiliary pump 13 are provided in the middle of the fuel feed pipe 127.
4 and are provided.

The auxiliary pump 134 compensates for the decrease in suction force due to the use of the pump injector 126, and may be small in size. The filter 133 prevents foreign matter generated by the auxiliary pump 134 from entering the pump injector 126. The filter 133 can be omitted if the auxiliary pump 134 does not have a risk of generating foreign matter. The auxiliary pump 134 can also circulate the fuel positively through the fuel feed pipe 127 and the return pipe 128 to discharge the vapor gas. In addition, in the first embodiment, an auxiliary pump and a filter may be provided as in the second embodiment.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention applied to a motorcycle, and the same reference numerals as those in FIG. 1 denote the same or equivalent parts. The present embodiment does not consider introducing the fuel feed pipe 127 from a substantially horizontal direction as in the first embodiment, and does not include the auxiliary pump and the filter as in the second embodiment. Instead, the fuel feed pipe 127 is set to have an inner diameter larger than the inner diameter that allows vapor gas generated in the pipe to move smoothly in the pipe due to its buoyancy.

Generally, the diameter of vapor gas bubbles is 5 mmφ.
Is less than. Therefore, if the inner diameter of the fuel feed pipe 127 is small, bubbles may stay due to the surface tension. By making it 5 mmφ or more, the fear disappears. In practice, the inner diameter of the fuel feed pipe 127 is preferably about 7 to 10 mmφ from the viewpoint of space, cost and the like. Also in the first and second embodiments, the fuel feed pipe 127 may have an inner diameter not smaller than the inner diameter that allows vapor gas generated in the pipe to move smoothly in the pipe due to its buoyancy.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention applied to a motorcycle which is a scooter type vehicle. The motorcycle 200 includes a vehicle body frame 201 and a head pipe 201a of the vehicle body frame 201. The attached front fork 202, the front wheel 203 attached to the front fork 202, the handle 204 connected to the front fork 202, the power unit 205 attached to the rear portion of the vehicle body frame 201 so as to be vertically swingable, and the rear wheel attached to the power unit 205. 206 and a rear cushion unit 2 in which the rear end of the power unit 205 is suspended.
07, a storage box (luggage box) 208 attached to the upper rear portion of the vehicle body frame 201, and a seat 209 openably and closably attached on the storage box 208. A helmet or the like can be stored in the storage box 208.

The body frame 201 includes the head pipe 20.
A front frame 201F and a rear frame 201R, which are integrally formed with 1a, are connected by a connecting portion 201X.
The power unit 205 includes an engine 210 and a belt type continuously variable transmission 211 with a centrifugal clutch. The engine 210 includes a cylinder block 212 and a cylinder head 2.
13 to face the head cover 214, that is, the cylinder portion between the storage box 208 and the fuel tank 215,
It is a water-cooled 4-cycle engine that is tilted in a substantially horizontal direction.

The refueling cap 215a with a lock provided in the fuel tank 215 appears when the refueling lid 216 is opened to the front upper side, and refueling is possible from here. The fuel tank 215 is provided with a fuel unit 217 for detecting the remaining amount of fuel.

Body cover 2 for covering the body frame 201
18 is a front cover 219 and a leg shield 22.
0, a step floor (a low floor type footrest plate) 221, a pair of left and right floor side covers 222, and an undercover 22
3, a lower seat cover 224, and a rear cover 225
And a pair of left and right side covers 226. A fuel tank 215 and an auxiliary pump 227 are arranged below the step floor 221.

The motorcycle 200 includes an air cleaner 228 provided on the left side of the vehicle body and a crankshaft 21 of the engine 210.
0a radiator provided on the right side of 0a,
Engine exhaust pipe 231, exhaust muffler 232 provided on the right side of the vehicle body, engine starting kick pedal 233, main stand 234, fuel feed pipe 235, return pipe 2
36, the auxiliary pump 22 in the middle of the fuel feed pipe 235
7 is provided with a filter 237 and a pump / injector 238. The pump injector 238 is shown in FIG.
Alternatively, as shown in FIG. 10, the fuel pump and the injection nozzle are integrated.

In the motorcycle 200, the fuel tank 215
Is higher than the pump injector 238. Reduction of suction force due to use of pump / injector 238, fuel tank 215 and pump / injector 236
The auxiliary pump 227 compensates for the decrease in the suction force due to the difference in reverse height with respect to. Further, by using the pump injector 238 in which the fuel pump and the injection nozzle are integrated, the problem of the arrangement space of the fuel device is solved. Similar to the third embodiment, when the fuel feed pipe 235 has an inner diameter that allows the vapor gas generated in the pipe to move smoothly in the pipe due to its buoyancy, the vapor gas discharge effect can be further enhanced.

Although the fuel feed pipe on the fuel supply side has been described above, the return pipe may be modified as described below. Further, the present invention becomes more effective by devising the fuel feed piping described in the first to third embodiments in addition to the devising of the return piping described below. The device of the return pipe will be described below.

As shown in FIG. 2, the pump injector 126
If the return pipe 128 takes the form of a mountain portion near the outlet of, the vapor gas may accumulate at that portion. As shown in FIG. 1, the return pipe 128 is connected to the pump injector 126.
From the horizontal direction, as shown in FIG. 3, the return pipe 128 has a diameter larger than the inner diameter such that vapor gas generated in the pipe can smoothly move in the pipe due to its buoyancy. The retention of vapor gas in the section can be reduced.

The structure of the open end of the return pipe 128 may be devised. Three examples of this are shown in FIGS. In FIG. 5, a convex chamber 31 partitioned by a filter 30 is formed at a position above the oil level in the fuel tank 129, for example, in the upper part of the fuel tank 129, and the open end of the return pipe 128 is exposed there. is there.

With this structure, the resistance of excess fuel and vapor gas when returning through the return pipe 128 becomes small. Further, even if the oil level rises above the open end of the return pipe 128 when the vehicle is inclined, foreign matter such as dust contained in the fuel passes through the return pipe 128 and the pump / injector 12
Do not break into 6.

FIG. 6 shows that the open end of the return pipe 128 is exposed at a position above the oil level in the fuel tank 129.
Similar to, but at the open end of the return pipe 128, for example,
A check valve in which a steel ball 41 is arranged is provided in the chamber where the return hole 40 is formed, and excess fuel or vapor gas is returned through the return pipe 128 and the fuel in the fuel tank is returned through the return pipe 1.
Prevent entry into 28. FIG. 7 shows that when the vehicle tilts above a certain level, the steel ball 51 moves and the force of the spring 52 causes the valve 5 to move.
When 0 is closed, the open end of the return pipe 128 is closed. In addition, various modified configurations can be adopted such as an open end of the return pipe 128 having a bending structure similar to that of a snorkel.

The fuel feed pipes 127 and 235 and the return pipes 128 and 236 do not feed the high pressure fuel pressurized by the fuel pump and are not required to have a high pressure resistance, so that they are made of flexible pipes such as rubber. Tubes can be used, which makes the layout free and easy. In a vehicle such as a motorcycle, the vertical movement of the power unit that occurs during driving is damped by using a flexible pipe.

[0046]

As is apparent from the above description, according to the present invention, a fuel pump for fuel injection and an injection nozzle are integrated to form a small pump injector, and a fuel feed pipe for the pump injector is formed. By devising the return pipe and the return pipe, it is possible to reduce the size, eliminate the problem of the arrangement space and increase the degree of freedom of layout.Furthermore, bubbles mixed in the fuel, so-called vapor gas, are generated in the fuel feed pipe and the return pipe. Can be prevented from staying in the.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention applied to a motorcycle.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention applied to a motorcycle.

FIG. 3 is a configuration diagram showing a first embodiment of the present invention applied to a motorcycle.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention applied to a motorcycle which is a scooter type vehicle.

FIG. 5 is a configuration diagram showing an example of an open end of a return pipe according to the present invention.

FIG. 6 is a configuration diagram showing another example of the open end of the return pipe in the present invention.

FIG. 7 is a configuration diagram showing still another example of the open end of the return pipe in the present invention.

FIG. 8 is a schematic diagram showing an example of a pump injector used in the present invention.

FIG. 9 is a schematic diagram showing an example of a pump drive unit of a pump / injector.

FIG. 10 is a schematic view showing another example of the pump injector used in the present invention.

FIG. 11 is a configuration diagram showing a conventional fuel injection type fuel device.

[Explanation of symbols]

10, 20 ... Sub-tank, 11, 21 ... Pump drive unit, 14, 25 ... Fuel pump unit, 15, 26 ... Injection nozzle, 19, 24, 128, 236 ... Return pipe, Three
0, 133, 237 ... Filter, 100, 200 ... Motorcycle, 101 ... Underbone frame, 122,
228 ... Air cleaner, 123 ... Intake pipe, 124, 2
31 ... Exhaust pipe, 125 ... Throttle valve, 126,
238 ... Pump / injector, 127, 235 ... Fuel feed pipe, 129, 215 ... Fuel tank, 13
4,227 ... Auxiliary pump

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 37/00 331 F02M 37/18 Z 37/18 55/00 A 55/00 B D 55/02 340Z 55 / 02 340 57/02 330A 57/02 330 59/44 G 59/44 B60K 15/02 Z F term (reference) 3D038 CA11 CA26 CC17 3G066 AA00 AA01 AB02 AD10 BA37 BA67 CA01U CA03 CA08 CA09 CA18 CA20T CB01 CB04 CB16 CC06T CC40 CD01 CD02 CD12 CD17 CD30 CE13 CE22 DB01

Claims (19)

[Claims] 1. A pump injector in which a fuel pump for fuel injection and an injection nozzle are integrated, a fuel feed pipe for supplying fuel from a fuel tank to the pump injector, and excess fuel from the pump injector. And a return pipe for returning vapor gas to the fuel tank, wherein at least one of the fuel feed pipe and the return pipe is led out from the pump / injector in a substantially horizontal direction. 2. The fuel system according to claim 1, wherein the pump injector is arranged with its axis inclined from the vertical direction, and the fuel feed pipe is led out from the lower side of the pump injector. . 3. A pump injector in which a fuel pump for fuel injection and an injection nozzle are integrated, a fuel feed pipe for supplying fuel from a fuel tank to the pump injector, and excess fuel from the pump injector. And a return pipe for returning vapor gas to the fuel tank, and an auxiliary pump provided in the middle of the fuel feed pipe. 4. The fuel system according to claim 3, further comprising a filter provided on the fuel feed pipe on a side closer to the pump / injector than the auxiliary pump. 5. The fuel system according to claim 3, wherein at least one of the fuel feed pipe and the return pipe is led out from the pump injector in a substantially horizontal direction. 6. The fuel system according to claim 3, wherein the pump injector is located lower than the fuel tank. 7. A pump injector in which a fuel pump for fuel injection and an injection nozzle are integrated, a fuel feed pipe for supplying fuel from a fuel tank to the pump injector, and excess fuel from the pump injector. And a return pipe for returning vapor gas to the fuel tank, and at least one of the fuel feed pipe and the return pipe has an inner diameter equal to or larger than the vapor gas generated in the pipe can smoothly move in the pipe due to its buoyancy. A fuel device characterized by being present. 8. The fuel system according to claim 7, wherein at least one of the fuel feed pipe and the return pipe is led out from the pump injector in a substantially horizontal direction. 9. The fuel system according to claim 7, further comprising an auxiliary pump provided in the fuel feed pipe. 10. The fuel device according to claim 1, wherein the fuel feed device and the return pipe are flexible pipes. 11. The fuel system according to claim 10, wherein the flexible pipe is a rubber pipe. 12. The fuel system according to claim 1, wherein the open end of the return pipe is exposed at a position above the fuel surface in the fuel tank. 13. The fuel system according to claim 12, further comprising a filter for preventing foreign matter such as dust from entering through the open end of the return pipe. 14. The fuel system according to claim 12, wherein a check valve is provided at an open end of the return pipe. 15. The fuel system according to claim 1, which is applied to a motorcycle. 16. The fuel system according to claim 15, wherein the fuel feed pipe and the return pipe are arranged along an underbone frame. 17. A pump injector in which a fuel pump for fuel injection and an injection nozzle are integrated, comprising a fuel intake port, a supply port for supplying internal fuel to the fuel pump, and an internal part provided at an upper part. A sub-tank having a discharge port for discharging vapor gas, a fuel pump concentrically provided in the sub-tank, for injecting fuel supplied from the sub-tank from an injector and discharging surplus fuel from a return port, and the fuel pump. An injection nozzle for injecting pressurized fuel, the pump injector. 18. A pump / injector in which a fuel pump for fuel injection and an injection nozzle are integrated, the fuel injector, a supply port for supplying internal fuel to the fuel pump, and an internal part provided at an upper part. A sub-tank having a discharge port for discharging vapor gas, a fuel pump provided outside the sub-tank for injecting fuel supplied from the sub-tank from an injector and discharging surplus fuel from a return port, and pressurizing by the fuel pump And a fuel injection nozzle for injecting the injected fuel. 19. The discharge pipe connected to the discharge port of the sub-tank is directed in the same direction as the flow direction of the surplus fuel returned from the return port of the fuel pump. The listed pumps and injectors.