JP2003239830A - Fuel injector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injector effectively discharging vapor generated in a fuel supply passage 31 communicating a fuel pump with a fuel injection valve J into a fuel tank T via a pressure regulator R, continuously supplying accurate fuel from the fuel injection valve J to an engine E, and suiting a two wheeler with small displacement. <P>SOLUTION: A plunger pump 1 is used as the fuel pump, the plunger pump 1 is arranged adjacently to the fuel tank T in a position higher than the engine E, and a discharge passage 7 of the plunger pump 1 is communicated with the fuel injection valve J arranged in a lower position in a neighborhood of the engine E via the fuel supply passage 31. The pressure regulator R is arranged at the upper part than the fuel injection valve J and in proximity to the plunger pump 1, an inflow passage 23 of the pressure regulator R is connected with the discharge passage 7 of the plunger pump 1, and an outflow passage 24 is connected with the fuel tank T via a return fuel passage 33. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device that sucks fuel in a fuel tank by a fuel pump and supplies the fuel pressurized by the fuel pump to an engine through a fuel injection valve. In particular, the present invention relates to a fuel injection device used for a two-wheeled vehicle and an equivalent three-wheeled vehicle or four-wheeled vehicle, a general-purpose engine, or the like.

[0002]

2. Description of the Related Art A conventional fuel injection device is disclosed in Japanese Patent Laid-Open No. 2001-1.
No. 40733. According to this, the fuel tank is arranged above the engine, the plunger pump is arranged below the fuel tank, and the inflow passage of the plunger pump and the fuel tank are connected via the fuel inflow passage. Further, a fuel injection valve for injecting and supplying fuel to the engine is attached to an intake pipe connected to the engine, and this fuel injection valve is connected to the discharge passage of the plunger pump via the fuel supply passage. On the other hand, the pressure regulator that regulates the fuel pressure in the fuel supply passage toward the fuel injection valve to a predetermined pressure is
It is attached to the end of the fuel injection valve on the fuel inflow side, and the return fuel passage of the pressure regulator is connected to the fuel tank. Thus, the fuel stored in the fuel tank flows into the plunger pump through the fuel inflow passage, and the fuel boosted by the plunger pump flows into the fuel injection valve through the discharge passage and the fuel supply passage. The fuel pressure that is supplied toward the fuel supply passage and that flows in the fuel supply passage at this time is adjusted to a predetermined fuel pressure by the pressure regulator, and thus fuel having a predetermined fuel pressure is supplied to the fuel injection valve. On the other hand, the surplus fuel in the pressure regulator is recirculated into the fuel tank through the return fuel passage.

[0003]

According to such a conventional fuel injection device, the vapor generated in the fuel supply passage connecting the plunger pump and the fuel injection valve is located at the end of the fuel injection valve on the fuel inflow side. However, some of this vapor may be caught in the fuel flow toward the fuel injection valve and enter the fuel injection valve. When the vapor is discharged from the fuel injection valve toward the engine, accurate metering of fuel is hindered. And fuel is intermittently supplied. However, it will not be possible to obtain good engine operation. This is particularly remarkable when the engine displacement is small (for example, 50 cc to 250 cc).

The present invention has been made in view of the above problems, and prevents vapor generated in the fuel supply passage connecting the fuel pump and the fuel injection valve from being discharged from the fuel injection valve. An object of the present invention is to provide a fuel injection device capable of continuously supplying accurate fuel from a fuel injection valve to an engine, and particularly suitable for use in an engine having a small displacement.

[0005]

In order to achieve the above-mentioned object, a fuel tank according to the present invention has a fuel tank arranged above an engine, the fuel in the fuel tank is pressurized by a fuel pump, and a pressure regulator is provided. In the fuel injection device in which the fuel whose pressure is adjusted to a predetermined fuel pressure is supplied to the engine through the fuel injection valve, the fuel pump is
An electromagnetically driven plunger type fuel pump, which supplies fuel to a fuel injection valve which is disposed near a bottom portion of a fuel tank and whose discharge passage is disposed near the engine below the fuel tank. On the other hand, a pressure regulator for adjusting the fuel pressure discharged from the fuel pump to a predetermined pressure, which is connected through a passage, is arranged above the fuel injection valve and close to the fuel pump, and The first feature is that the inflow passage is connected to the discharge passage of the fuel pump, and the outflow passage of the pressure regulator is connected to the fuel tank via the return fuel passage.

According to the present invention, in addition to the first feature, the pump body forming the plunger type fuel pump has an insertion cylinder portion extending upward and a mounting collar arranged on a side of the insertion cylinder portion. And a solenoid portion including a housing, a fixed iron core, an electromagnetic coil, and a movable iron core is attached to the mounting flange portion, and a plunger reciprocally driven by the solenoid portion and a suction side are provided in the pump body. The fixed iron core is equipped with a pressure regulator, and the fixed iron core is equipped with a pressure regulator, while the fixed iron core is provided with a discharge passage communicating with the pump portion, and the pressure regulator is introduced. A second feature is that the passage is connected to the discharge passage and the fuel supply passage connected to the fuel injection valve is connected to the discharge passage.

Further, in addition to the second characteristic, the present invention provides
A third feature is that the fuel supply passage is connected from a lower position in the gravity direction toward the discharge passage of the fixed iron core.

Further, in addition to the second feature of the present invention, the insertion cylinder portion of the pump body is provided with a first fuel passage which is in the insertion cylinder portion and opens toward an upper end surface of the insertion cylinder portion. , A second fuel passage is bored, the first fuel passage is connected to the pump portion via the inflow passage, the second fuel passage is connected to the pressure regulator outflow passage via the return fuel passage, and the insertion tubular portion is further provided. The fourth feature is that the pump body is attached to the fuel tank by inserting and arranging the pump body into the insertion hole that opens at the bottom of the fuel tank.

[0009]

According to the first feature of the fuel injection device of the present invention, the fuel stored in the fuel tank is boosted by the plunger type fuel pump disposed near the bottom of the fuel tank, and the fuel is The fuel is supplied to the fuel injection valve arranged below the fuel tank through the discharge passage and the fuel supply passage of the plunger type fuel pump. On the other hand, the pressure regulator is located above the fuel injection valve and close to the plunger type fuel pump. A part of the fuel flowing through the discharge passage of the plunger type fuel pump enters the pressure regulator through the inflow passage. The surplus fuel flowing in and in the pressure regulator is recirculated into the fuel tank through the outflow passage and the return fuel passage. here,
The vapor generated in the fuel supply passage that connects the plunger type fuel pump and the fuel injection valve moves upward in the fuel supply passage due to the buoyancy of the vapor itself, and the vapor is the plunger type. It enters into the pressure regulator from the discharge passage of the fuel pump, and is further discharged into the fuel tank from the return fuel passage. As described above, the vapor generated in the fuel supply passage is discharged into the fuel tank by using the plunger type fuel pump as the fuel pump, and the discharge pressure of the pump is, for example, 150.
The pressure was low around kpa, and the discharge amount per pulse of the plunger of the plunger type fuel pump could be set to a small amount, for example, about 3 mm ³ . And the plunger type fuel pump is arranged near the bottom of the fuel tank, the fuel injection valve is arranged below the fuel tank, and the pressure regulator is arranged near the plunger type fuel pump above the fuel injection valve. by.
Thus, the fuel injected and supplied from the fuel injection valve to the engine does not contain vapor, and accurate and stable fuel can be supplied to the engine.

According to the second aspect of the present invention, the pump body of the plunger type fuel pump is provided with an insertion cylinder portion and a flange portion, and is a solenoid portion including a housing, a fixed iron core, an electromagnetic coil and a movable iron core. Is attached to the mounting flange, and the pump portion including the plunger, the suction side check valve, and the discharge side check valve is arranged in the pump body, and the pressure regulator is attached to the fixed iron core. The fixed iron core of the solenoid portion is provided with a discharge passage continuous with the pump portion, and the inflow passage of the pressure regulator and the fuel supply passage are connected to the discharge passage. Thus, the pressure regulator can be extremely easily arranged in the vicinity of the plunger type fuel pump, and the fuel supply passage and the discharge passage and the pressure regulator inflow passage and the discharge passage can be easily connected.

Further, according to the third aspect of the present invention, since the fuel supply passage connected to the fuel injection valve is connected from the lower position toward the discharge passage of the fixed iron core, the vapor generated in the fuel supply passage is self-contained. Due to the buoyancy of the, it surely flows into the discharge passage. The vapor in the discharge passage can be surely discharged into the fuel tank from the return fuel passage through the inflow passage and the outflow passage of the pressure regulator opening in the discharge passage.

Still further, according to the fourth aspect of the present invention, the first fuel passage and the second fuel passage are provided on the upper end surface of the insertion cylinder portion of the pump body.
The fuel passage and the fuel passage are opened, the first fuel passage is connected to the inflow passage of the pump portion, and the second fuel passage is connected to the return fuel passage of the pressure regulator. The plunger type fuel pump can be connected and arranged to the fuel tank by inserting and arranging the insertion tube portion into the insertion hole of the fuel tank, and by this, the connecting pipe between the inflow passage of the plunger type fuel pump and the fuel tank and Connection piping between the return fuel passage and the fuel tank can be easily performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the fuel injection device according to the present invention will be described below. FIG. 1 shows an electromagnetically driven plunger type fuel pump that constitutes a fuel injection device, and will be referred to as a plunger pump in the following description. Plunger pump 1 is formed by: Reference numeral 2 denotes a pump body having an annular mounting flange portion 2B formed at the left end 2A of FIG. 1, and a movable iron core guide hole 2C and a plunger are provided from the left end 2A toward the right pump body 2. The hole 2D is continuously provided, and the inflow passage 2F opens from the bottom of the plunger hole 2D toward the right end via the intake valve seat 2E. S is
A solenoid portion arranged at the left end 2A of the pump body 2 and includes the following. Reference numeral 3 denotes a bottomed cup-shaped housing made of a conductive material, and a flange portion 3A extending laterally is formed at an opening end on the right side. Reference numeral 4 denotes a cylindrical coil bobbin which is inserted and arranged from the opening end on the right side of the housing 3 toward the bottom, and the electromagnetic coil 5 is laminated and wound around the outer circumference thereof. Reference numeral 6 denotes a fixed iron core fixed to the center of the bottom of the housing 3 and to the right of the fixed iron core made of a conductive material inserted and arranged in the coil bobbin 4. From the right end to the left end at the center of the fixed iron core 6. The discharge passage 7 is penetrated and drilled. Reference numeral 8 denotes a hollow cylindrical movable iron core that is arranged opposite to the right end of the fixed iron core 6 and is slidably arranged in the coil bobbin 4. The movable iron core 8 is fixed by the first spring 9 to the fixed iron core 6 of the fixed iron core 6. It is biased away from the right end. The movable iron core 8 is made of a magnetic material.

The solenoid portion S having the above structure is attached to the pump body 2 as follows. The open end of the housing 3 is inserted and arranged on the outer periphery of the mounting flange portion 2B of the pump body 2. At this time, a sealing member such as an O-ring is arranged between the inner periphery of the opening end of the housing 3 and the outer periphery of the mounting collar 2B, and the left end 2A of the pump body 2 and the right end of the coil bobbin 4 are arranged. A magnetic pole disk 10 made of a magnetic material is disposed between the movable core 8 and the flange portion, and the right end of the movable iron core 8 is movably inserted in the movable iron core guide hole 2C of the pump body 2. Then, in such a state, the flange portion 3A extending to the side of the housing 3 is screwed to the pump body 2 with a screw, so that the solenoid portion S is attached to the pump body 2. On the other hand, the plunger 11 is arranged so as to be able to move back and forth facing the inside of the plunger hole 2D of the pump body 2.
Is movably centered and supported, its right end faces the plunger hole 2D, and its left end abuts on the locking step portion 8A of the movable iron core 8. In addition, 13 is a second for contacting the left end of the plunger 11 with the locking step portion 8A of the movable iron core 8.
It is a spring. Therefore, the movable iron core 8 and the plunger 11 are brought into contact with each other in the locking step portion 8A by the spring force of the first spring 9 and the second spring 13, and are supported in the locked state. The state of the movable iron core 8 and the plunger 11 shown in FIG. 1 shows a state in which the electromagnetic coil 5 is not energized. On the other hand, the plunger hole 2D forms the pump chamber 14 by disposing the plunger 11,
The pump chamber 14 has a suction valve seat 2E connected to the inflow passage 2F.
Is opened, and the suction side check valve 1 faces the suction valve seat 2E.
5 are arranged. Further, the pump chamber 14 and the movable iron core guide hole 2C are communicated with each other through the outflow passage 16, and the outflow passage 16 is provided with a discharge valve seat 2G facing the movable iron core guide hole 2C. Discharge side check valves 17 are arranged opposite to each other. That is, the plunger 11, the suction-side check valve 15, and the discharge-side check valve 17 constitute the pump portion P. Further, at the left end of the fixed iron core 6, the fixed iron core 6
A fuel joint 18 connected to a discharge passage 7 penetrating through the fuel passage 18 is screwed, and the fuel joint 18 includes a first fuel joint 18A connected to the discharge passage 7 and a second fuel joint 18B connected to the discharge passage 7. Prepare That is, the first fuel joint 18A and the second fuel joint 18B both branch to the discharge passage 7.

FIG. 2 shows the pressure regulator R. The reference numeral 20 designates a housing having a fuel chamber 21 and a spring chamber 22.
The fuel chamber 21 has an inflow passage 23 and an outflow passage 24, and the outflow passage 24 opens in the fuel chamber 21 with a valve seat 25. On the other hand, a valve body 26 for controlling the opening of the valve seat 25 is integrally attached to the diaphragm 20.
A diaphragm spring 27 that is contracted inside 2 urges the valve seat 25 to close it.

The plunger pump 1 and the pressure regulator R having the above structure are mounted on a motorcycle as follows. This is shown in FIG. In the two-wheeled vehicle 2W in this example, the engine E is arranged in the lower position near the wheels, and the fuel tank T is arranged in the upper position near the seat. An intake pipe EA and an exhaust pipe EB are connected to the engine E, and the intake pipe EA is connected to an air cleaner C via a throttle body B.
And the exhaust pipe EB is connected to the muffler D.
An intake passage Ba that penetrates the inside of the throttle body B is opened and closed by a throttle valve Bb operated by a driver, and the fuel injection valve J is attached to the throttle body B as in this example, or It is attached to the intake pipe EA. Therefore, the fuel injection valve J is in the vicinity of the engine E and the fuel tank T
It will be arranged in a lower position.

The plunger pump 1 is attached to the bottom portion Ta of the fuel tank T by a fastening member such as a fastening band (not shown). Therefore, the plunger pump 1 is arranged above the fuel injection valve J. Further, the pressure regulator R is arranged close to the plunger pump 1, and in this example, is attached to a position near the bottom Ta of the fuel tank T and above the plunger pump 1 by a fastening member such as a fastening band. .
Therefore, the pressure regulator R is arranged close to the plunger pump 1 and above the fuel injection valve J.

The fuel injection valve J, the plunger pump 1 and the pressure regulator R are connected by piping as follows. That is, the inflow passage 2F of the plunger pump 1 and the fuel tank T are connected by the fuel inflow passage 30. Further, the first fuel joint 18A of the plunger pump 1 and the fuel injection valve J are connected by the fuel supply passage 31.

The operation of the fuel injection device constructed as above will be described. A driving pulse signal is input to the electromagnetic coil 5 of the plunger pump 1 in synchronization with the operation of the engine E, and the movable iron core 8 resists the spring force of the first spring 9 when the electromagnetic coil 5 is energized. Then, it is sucked and moved from the original position to the fixed iron core 6 side.
The spring force of the spring 13 moves to the left in FIG. 1 so as to follow the movable iron core 8. According to the above, the chamber volume of the pump chamber 14 increases and the pressure in the pump chamber 14 decreases, whereby the discharge side check valve 17 closes the discharge valve seat 2G and the suction side check valve 15 sucks. The valve seat 2E is opened, and the fuel in the fuel tank T is introduced into the fuel inflow passage 3
0, and is sucked into the pump chamber 14 through the inflow passage 2F.
Next, when the power supply to the electromagnetic coil 5 is cut off, the movable iron core 8
Is returned to the right-side original position by the spring force of the first spring 9, and at this time, the plunger 11 moves the movable iron core 8
It is mechanically pressed to the right by the locking stepped portion 8A and is returned to the original position on the right in synchronization with the movable iron core 8. According to the above,
As the chamber volume of the pump chamber 14 decreases, the pump chamber 14
The internal pressure rises, whereby the suction side check valve 15 closes the suction valve seat 2E and the discharge side check valve 17 opens the discharge valve seat 2G. The sucked fuel is discharged into the movable core guide hole 2C through the outflow passage 16. The plunger 11 reciprocates in the pump chamber 14 by continuously inputting the drive pulse signal for energizing and blocking the electromagnetic coil, and the pressurized fuel flows out from the pump chamber 14. It is continuously discharged through the passage 16, the movable iron core guide hole 2C, and the inside of the movable iron core 8 to the discharge passage 7 formed in the fixed iron core 6. In addition, 11A is a notch groove provided in the flange portion at the left end of the plunger 11, and this notch groove 11A allows the fuel flow from the movable core guide hole 2C to the discharge passage 7.

Then, a part of the fuel in the discharge passage 7 is supplied to the fuel injection valve J via the first fuel joint 18A and the fuel supply passage 31, and the other portion of the fuel in the discharge passage 7 is supplied to the second fuel. It is supplied to the pressure regulator R via the joint 18B and the fuel introduction passage 32. In the pressure regulator R, the fuel pressurized by the plunger pump 1 is introduced into the fuel chamber 21 of the pressure regulator R via the discharge passage 7, the fuel introduction passage 32, and the inflow passage 23, and the fuel chamber 21 Is filled with fuel and pushes up the valve element 26 through the diaphragm 20 to open the valve seat 25, and the diaphragm spring 27 in the spring chamber 22 is set at a set pressure.
And the fuel pressure discharged from the discharge passage 7 can be maintained at a predetermined set pressure. On the other hand, when the valve body 26 opens the valve seat 25, the fuel flowing from the fuel chamber 21 into the outflow passage 24 is recirculated into the fuel tank T through the return fuel passage 33. Therefore, from the plunger pump 1 to the discharge passage 7, the first
Fuel having a predetermined fuel pressure can be supplied toward the fuel injection valve J via the fuel joint 18A and the fuel supply passage 31, and the fuel injection valve J is supplied to the engine E based on an injection signal from an ECU (not shown). Fuel is injected toward

Here, in the motorcycle, the ambient temperature of the engine becomes a high temperature state, for example, during idling operation in summer,
Alternatively, vapor is generated in the fuel supply passage 31 having a relatively long passage in the vicinity of the engine E, which is easily affected by heat during low-speed traveling operation, etc. By using a fuel injector,
It is possible to effectively prevent the vapor from being discharged from the fuel injection valve J without preparing special vapor separating means and vapor discharging means. This is achieved by: First, the electromagnetically driven plunger pump 1 was used as the fuel pump. Secondly, the fuel injection valve J is arranged at a low position near the engine E, and the plunger pump 1 is arranged near the fuel tank T above the engine E. Thirdly, the pressure regulator R is arranged above the fuel injection valve J and in the vicinity of the plunger pump 1. Is organically bound. That is, since the plunger pump 1 is used as the fuel pump, the discharge pressure of the pump is 250 kp for the Wesco type pump and the roller type pump, which are conventionally used in four-wheel vehicles.
The pressure can be easily lowered as compared with a from 300 kpa, and the pressure-reduced fuel can be further easily adjusted to a predetermined low pressure by the pressure regulator R. The fuel pressure reduced by the pressure regulator R is about 150 kpa, for example. It is possible to lower the fuel pressure of 250 kpa to 300 kpa by the conventional fuel pump to 150 kpa by using the pressure regulator R, but it is not preferable because it is necessary to enhance the pressure regulation accuracy of the pressure regulator R. Moreover, by using the plunger pump 1, the discharge amount per pulse of the plunger 11 can be made small, for example, about 3 mm ³ . According to the above, the pressure of the fuel flowing in the fuel supply passage 31 from the plunger pump 1 to the fuel injection valve J and the flow velocity of the fuel can be greatly reduced as compared with the conventional case. On the other hand, focusing on the fuel supply passage 31, the lower end of the fuel supply passage 31 is connected to the fuel injection valve J in the lower position, and the upper end of the fuel supply passage 31 is connected to the plunger pump 1 in the upper position. The pressure regulator R is arranged close to the plunger pump 1. Therefore, the vapor generated in the fuel supply passage 31 easily moves upward in the fuel supply passage 31 toward the plunger pump 1 in the upper position by the buoyancy of the vapor.

As described above, according to the fuel injection device of the present invention, when vapor is generated in the fuel supply passage 31 which is arranged in the vicinity of the engine and has a relatively long passage length, the vapor is generated. The vapor moves upward in the fuel supply passage 31 due to the buoyancy of the vapor itself. At this time, the pressure of the fuel flowing in the fuel supply passage 31 and the flow velocity of the fuel are greatly reduced. The inside of the supply passage 31 can be reliably moved upward, and the first fuel joint 18A of the plunger pump 1 can be integrated into the discharge passage 7 of the plunger pump 1. On the other hand, the pressure regulator R is arranged in the vicinity of the plunger pump 1 and the fuel introduction path 3 of the pressure regulator R is provided.
2 is connected to the discharge passage 7 of the plunger pump 1 via the second fuel joint 18B, the vapor collected in the discharge passage 7 is
B, the fuel chamber 2 along with the fuel flowing from the fuel introduction passage 32 and the inflow passage 23 to the fuel chamber 21 of the pressure regulator R
Introduced into 1. Then, the vapor that has entered the fuel chamber 21 is, when the valve body 26 opens the valve seat 25 for pressure regulation,
The surplus fuel is discharged into the fuel tank T through the outflow passage 24 and the return fuel passage 33. In this way, the vapor can be effectively discharged from the pressure regulator R because the pressure regulator R is the fuel injection valve J.
This is because it is located at a higher position and close to the plunger pump 1. Further, during idling operation and low speed operation of the engine, the amount of return fuel from the return fuel passage 33 of the pressure regulator R to the fuel tank T is particularly large, which is the vapor during the above operation where vapor is likely to occur. The dischargeability of can be greatly improved. Further, according to the present invention, the plunger pump 1 and the pressure regulator R are arranged in the vicinity of the fuel tank T, whereby the fuel connecting the fuel tank T and the inflow passage 2F of the plunger pump 1 is connected. It is possible to shorten the passage length of the fuel inlet passage 32 that connects the inlet passage 30 and the plunger pump 1 to the pressure regulator R, and the return fuel passage 33 that connects the pressure regulator R and the fuel tank T. The pipe exposed to the outside can be shortened, and it is particularly preferable for a motorcycle exposed to the outside of the pipe.
Further, since the fuel supply passage 31 is opened from the lower position in the direction of gravity toward the discharge passage 7 of the plunger pump 1 via the first fuel joint 18A, the fuel supply passage 31 is
The vapor generated inside is more easily collected in the discharge passage 7, and the dischargeability of the vapor through the pressure regulator R can be improved. Further, a discharge passage 7 is bored in the fixed iron core 6, and the first fuel joint 1 is attached to the fixed iron core 6.
By mounting the fuel joint 18 including the 8A and the second fuel joint 18B, the pipe connectivity with the fuel supply passage 31 and the fuel introduction passage 32 can be improved.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a vertical cross-sectional view showing a state in which a plunger pump having a pressure regulator is attached to a fuel tank. FIG. 5 is a top plan view of the plunger pump with the pressure regulator of FIG. Is. It should be noted that the same reference numerals are used for the same structural parts as those in FIGS. The pump body 40 includes an insertion cylinder portion 40A having a cylindrical shape extending upward and an insertion cylinder portion 4
A mounting flange portion 40B formed on the side of 0A is provided. A solenoid portion S including a housing 3, an electromagnetic coil 5, a fixed iron core 6, and a movable iron core 8 is screwed to the mounting flange portion 40B by screws. A pump portion P including a plunger 11, a suction side check valve 15, and a discharge side check valve 17 is arranged in the pump body 40, and the right end of the plunger 11 is moved by a first spring 9 and a second spring 13 into a movable core. It is locked to the locking step portion 8A of No. 8. The insertion cylinder 40A has a first fuel passage 41 opening toward the upper end surface 40B.
And the second fuel passage 42 are bored, and the first fuel passage 41 is connected to the pump chamber 14 via the inflow passage 25. Further, the fixed iron core 6 is provided with the discharge passage 7 from the right end to the left end, and the first fuel joint 18A branches downward from the middle of the discharge passage 7. Further, a pressure regulator R is screwed and fixed to a discharge passage 7 opening to the right end of the fixed iron core 6. This is a discharge passage through a male screw formed on the outer circumference of an inflow passage 23 connected to the fuel chamber 21. 7
It was screwed and fixed to. Therefore, the fuel chamber 21 is connected to the discharge passage 7 of the fixed iron core 6 via the inflow passage 23. The structure of the pressure regulator R itself is the same as that of FIG. 2, and 43 is a lock nut screwed to the male screw on the outer circumference of the inflow passage 23. Reference numeral 44 denotes a filter inserted and arranged in the first fuel passage 41 opening to the upper end surface 40B of the insertion tube portion 40A, and the filter 44 is arranged so as to project above the upper end surface 40B. According to the above, the insertion tube portion 4
0A and a mounting collar 40B are provided on the pump body 40. The pump body 40 includes a solenoid portion S and a pump portion P, and a pressure regulator R is provided on the fixed iron core 6 of the solenoid portion.
Is fixedly arranged, and the insertion cylinder portion 40A of the pump body 40 is inserted through the seal ring 44 into the insertion hole Tb formed in the bottom portion Ta of the fuel tank T. It is fixed to the tank T. In this example, it is fixed to the fuel tank T by a tightening band 45 arranged on the outer periphery of the housing 3. According to the above, the pump chamber 14 includes the inflow passage 2F and the first fuel passage 4
The second fuel passage 42, which is connected to the inside of the fuel tank T through the filter 44 and opens into the fuel tank T, includes the pressure regulator R through the return fuel passage 33.
To the outflow passage 24 of The first fuel joint 18A that opens to the discharge passage 7 of the fixed iron core 6 is connected to the fuel injection valve J, which is located below the fuel tank T and near the engine E, by the fuel supply passage 31.

According to this embodiment, as for the fuel in the fuel tank T, the fuel whose pressure is increased by the drive of the pump portion P by the solenoid portion S is discharged toward the discharge passage 7 of the fixed iron core 6, and the discharge passage 7 is formed. The fuel inside is regulated to a predetermined pressure by being introduced into the pressure regulator R, and the fuel having the regulated fuel pressure is supplied to the fuel supply passage 3
Is supplied to the fuel injection valve J via 1. On the other hand, the vapor generated in the fuel supply passage 31 moves upward in the fuel supply passage 31 due to its own buoyancy, as in the above-described embodiment, and from the discharge passage 7 of the fixed iron core 6 to the inflow passage 23 of the pressure regulator R. , Outflow passage 24, return fuel passage 3
3, the fuel is discharged into the fuel tank T through the second fuel passage 42.

According to this embodiment, since the discharge passage 7 is bored in the fixed iron core 6 which constitutes the solenoid S and the pressure regulator R is fixedly attached to the fixed iron core 6, the pressure regulator R is special. The plunger pump can be extremely closely arranged without using a fastening member. Further, since the pressure regulator R is directly attached to the fixed iron core 6, the fuel introduction passage 32 that connects the inflow passage 23 of the pressure regulator R and the discharge passage 7 of the plunger pump is unnecessary. The fuel piping can be simplified, which is particularly preferable in the piping layout of the motorcycle. Further, according to the above, the plunger pump and the pressure regulator R can be assembled in advance, the return fuel passage 23 can be connected by piping, and the plunger pump can be attached to the fuel tank T for mounting on the motorcycle. As a result, the assemblability was greatly improved.

Further, the insertion cylinder portion 40A of the pump body 40
Is provided with a first fuel passage 41 and a second fuel passage 42 that open to the upper end surface 40B of the insertion tubular portion 40A.
1 is connected to the pump chamber 14 via the inflow passage 2F, and the second fuel passage 42 is connected to the outflow passage 24 of the pressure regulator R via the return fuel passage 33. Insert hole T of tank T
By inserting into b, the connection between the pump chamber 14 and the fuel tank T and the connection between the outflow passage 24 of the pressure regulator R and the fuel tank T are completed. In particular, providing only a single insertion hole Tb in the fuel tank T makes it easy to modify the conventionally used fuel tank T.

[0027]

As described above, according to the fuel injection device of the present invention, an electromagnetically driven plunger type fuel pump is used as a fuel pump and is arranged close to the bottom portion Ta of the fuel tank T located above the engine E. , The discharge passage 7 of the plunger pump 1 is connected to the fuel injection valve J in the lower position in the vicinity of the engine E via the fuel supply passage 31, and the pressure regulator R is located above the fuel injection valve J and in the plan. By arranging in the vicinity of the jar pump 1, the vapor generated in the fuel supply passage 31 can be surely prevented.
The fuel can be discharged from the inside to the fuel tank T, and thereby the fuel can be supplied more accurately and stably than the fuel injection valve J, and the idling drivability and the low speed drivability can be improved especially in a motorcycle with a small displacement. it can. In addition, the passage lengths of the fuel inflow passage 30, the fuel introduction passage 32, and the return fuel passage 33 can be made extremely short, and the pipeability in a two-wheeled vehicle can be particularly improved. Further, its lower end is connected to the fuel injection valve J, and its upper end is the fixed iron core 6 of the plunger pump 1.
Since the fuel supply passage 31 connected to the discharge passage 7 provided in the fuel supply passage 31 is opened from the lower position in the gravity direction into the discharge passage 7, the vapor generated in the fuel supply passage 31 is collected toward the discharge passage 7. It is easy to do so that the dischargeability of vapor from the pressure regulator R into the fuel tank T can be further improved. In addition, the pump body 40 of the plunger pump 1 is formed by the insertion cylinder portion 40A and the mounting flange portion 40B, the solenoid portion S is attached to the mounting flange portion 40B, and the pump portion P is provided in the pump body 40. Attach the regulator R to the fixed iron core 6 of the solenoid S.
The pressure regulator R is extremely easy to be mounted by connecting the discharge passage 7 attached to the fixed core 6 to the fuel supply passage 31 connected to the fuel injection valve J and the inflow passage 23 of the pressure regulator R. In addition, the plunger pump 1 and the pressure regulator R can be sub-assembled in the vicinity of the plunger pump 1 and the mountability on the fuel tank T can be improved. Further, the first fuel passage 41 opening to the upper end surface 40B of the insertion tubular portion 40A is connected to the pump chamber 1 via the inflow passage 2F.
4 and the second fuel passage 42 is connected to the outflow passage 24 of the pressure regulator R via the return fuel passage 33. Therefore, the insertion cylinder portion 40A is inserted and arranged in the insertion hole Tb of the fuel tank T. The fuel tank T can be connected to the plunger pump 1 and the pressure regulator R by the fuel tank T.
The connection workability with can be greatly improved. Further, since the fuel tank T may be provided with the single insertion hole Tb, the production of the fuel tank T is simplified.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a plunger pump used in a fuel injection device of the present invention.

FIG. 2 is a vertical cross-sectional view of a pressure regulator used in the fuel injection device of the present invention.

FIG. 3 is a piping diagram showing a state where the fuel injection device of the present invention is mounted on a motorcycle.

FIG. 4 is a vertical cross-sectional view showing an embodiment of a plunger pump having a pressure regulator used in the fuel injection device of the present invention.

5 is a top plan view of the plunger pump in FIG.

[Explanation of symbols]

1 Plunger pump 2F inflow path 3 housing 5 electromagnetic coil 6 fixed iron core 7 discharge path 8 movable iron core 11 Plunger 15 Intake side check valve 17 Discharge side check valve 23 Inflow path 24 Outflow 31 Fuel supply path 33 Return fuel passage 40A insertion tube 40B upper end surface 41 First fuel passage 42 Second fuel passage E agency J fuel injection valve P pump section R Pressure Regulator S solenoid part T fuel tank

Claims (4)

[Claims] 1. A fuel tank is arranged above the engine, the fuel in the fuel tank is pressurized by a fuel pump, and the fuel whose pressure is regulated to a predetermined fuel pressure by a pressure regulator is sent to the engine through a fuel injection valve. In the fuel injection device to be supplied, the fuel pump is an electromagnetically driven plunger type fuel pump 1, which is arranged close to the bottom Ta of the fuel tank T and the discharge passage 7 of the fuel pump is connected to the fuel tank T. A pressure regulator R, which is connected to a fuel injection valve J arranged near the engine E at a lower position via a fuel supply passage 31, and which regulates the fuel pressure discharged from the fuel pump to a predetermined pressure, It is located above the fuel injection valve J and is arranged close to the fuel pump, and the inflow passage 23 of the pressure regulator R is connected to the fuel pump. Pump discharge passage 7 and pressure regulator R outflow passage 24 to return fuel passage 3
A fuel injection device characterized in that the fuel injection device is connected to a fuel tank T via a fuel cell. 2. A pump body 40 forming the plunger type fuel pump has an insertion cylinder portion 40A extending upward.
And the mounting collar 40 arranged on the side of the insertion cylinder 40A.
B, a solenoid portion S including a housing 3, a fixed iron core 6, an electromagnetic coil 5, and a movable iron core 8 is attached to the mounting flange portion, and is reciprocally driven in the pump body 40 by the solenoid portion. A pump portion P including a plunger 11, a suction side check valve 15, and a discharge side check valve 17.
In addition, the fixed core 6 is provided with a pressure regulator R, while the fixed core 6 is provided with a discharge passage 7 communicating with the pump portion P, and an inflow passage 23 of the pressure regulator R is provided in the discharge passage 7. The fuel supply device according to claim 1, wherein a fuel supply passage 31 connected to and connected to the fuel injection valve J is connected to the discharge passage 7. 3. The fuel supply device according to claim 2, wherein the fuel supply path is connected from a lower position in the direction of gravity toward the discharge path 7 of the fixed iron core 6. 4. A first fuel passage 41 and a second fuel passage 42, which are in the insertion cylinder portion 40A and open toward an upper end surface 40B of the insertion cylinder portion 40A, are provided in the insertion cylinder portion 40A of the pump body. The first fuel passage 41 is formed in the inflow passage 2F.
Connected to the pump portion P via the second fuel passage 42 via the return fuel passage 33.
The pump body 40 is attached to the fuel tank T by connecting to the outflow passage 24 of the fuel tank T and further inserting the insertion cylindrical portion 40A into the insertion hole Tb opening to the bottom Ta of the fuel tank T. Item 2. The fuel supply device according to item 2.