JP2010190069A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device for achieving a reduced size, simplified construction, atomized spray, stabilized spray forms, stabilized injection characteristics, and the like. <P>SOLUTION: The fuel injection device integrally includes a plunger pump 20 using a plunger 21 for compressing fuel, an injection valve 30 for injecting the fuel compressed by the plunger pump, a fuel passage 14 for communicating the plunger pump with the injection valve, and a fuel storage part 40 communicated with the fuel passage for storing the fuel compressed by the plunger pump. The fuel storage part 40 includes a fuel chamber 41 communicated with the fuel passage, a moving member 42 to be moved to define part of the wall face of the fuel chamber and change the capacity of the fuel chamber, a back pressure chamber 43 shut off via the moving member from the fuel chamber, and an energizing member 44 for energizing the moving member in the direction of reducing the capacity of the fuel chamber. Thus, the device achieves a reduced size, simplified construction, atomized spray, stabilized spray forms, stabilized injection characteristics, and the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection device that pumps and injects fuel with a reciprocating plunger, and more particularly to a fuel injection device that is applied to inject fuel into an intake passage of a small engine mounted on a motorcycle or the like.

  As an electronically controlled fuel injection device mounted on a motorcycle or the like, a plunger pump that pressurizes fuel guided from a fuel tank by an electromagnetically driven plunger, and temporarily stores fuel pressurized by the plunger pump And a pressure regulator for returning excess pressurized fuel to the fuel tank, and a fuel injection valve for injecting fuel stored in the pressure regulator. It is known that fuel is injected into the fuel tank and excess fuel is returned from the pressure regulator to the fuel tank.

  However, in this fuel injection device, since the pressure of the fuel pressurized by the plunger pump is kept constant using a pressure regulator that returns excess pressurized fuel to the fuel tank, the fuel is injected by the fuel injection valve. When the fuel is injected, the pressure (fuel pressure) of the stored fuel in the pressure regulator is temporarily reduced, and the injection amount varies. In addition, due to the decrease in fuel pressure, it is difficult to make the spray finer, stabilize the spray shape, and the like, and it is difficult to stably inject the fuel. Further, since the pressure regulator is used to return a part of the fuel to the fuel tank, not all the fuel pressurized by the plunger pump is used (all the pressurized energy of the fuel can be converted into the kinetic energy of the fuel). But not energy efficient).

JP 2005-23800 A

  The present invention has been made in view of the circumstances of the above-described conventional apparatus, and its object is to simplify the structure, reduce the size of the apparatus, reduce pipe loss, improve energy efficiency, An object of the present invention is to provide a fuel injection device capable of achieving stable injection characteristics by miniaturization, stabilization of a spray shape, and the like.

A fuel injection device of the present invention communicates a plunger pump that pressurizes fuel by an electromagnetically driven plunger, an electromagnetically driven injection valve that injects fuel pressurized by the plunger pump, and the plunger pump and the injection valve. A fuel injection device that integrally includes a fuel passage that is connected to the fuel passage and that stores fuel pressurized by a plunger pump, the fuel storage portion communicating with the fuel passage. A moving member that defines a part of the wall surface of the fuel chamber and moves to change the volume of the fuel chamber, a back pressure chamber that is blocked from the fuel chamber through the moving member, and a volume of the fuel chamber is reduced. The structure includes a biasing member that biases the moving member in the direction.
According to this configuration, when the plunger pump is electromagnetically driven, fuel is pressurized by the pump action and supplied to the fuel passage and the fuel chamber as the downstream fuel reservoir, and the injection valve is electromagnetically driven. The fuel stored in the fuel passage and the fuel chamber is injected into the intake passage. At this time, even if the fuel stored in the fuel chamber (and the fuel passage) decreases, the moving member is urged by the urging member to reduce the volume of the fuel chamber, that is, the fuel stored in the fuel chamber. Because it works to constantly pressurize the fuel, it is possible to inject a predetermined amount of fuel stably (with no variation) at the desired timing. Also, atomization of the spray, stabilization of the spray shape, air pollution, etc. Reduction or the like can be achieved. Further, compared with the conventional technique in which the pressurized fuel is returned to the fuel tank, there is less loss when the pressurized energy is converted into kinetic energy, and energy efficiency can be improved. Furthermore, since the plunger pump, the injection valve, the fuel passage, and the fuel storage part are integrally formed, it is possible to achieve simplification of the structure, size reduction of the apparatus, and the like.

In the above configuration, the fuel chamber and the fuel passage may be arranged coaxially with the plunger pump.
According to this configuration, the fuel pressurized and discharged by the plunger pump is directly guided to the fuel passage and the fuel chamber that are located upstream of the injection valve and arranged coaxially with the plunger pump. There is little flow path loss, the energy efficiency in the pumping action of the plunger pump can be improved, the structure can be simplified, the number of parts can be reduced, and the apparatus can be downsized.

In the above configuration, the back pressure chamber may be configured to be open to the atmosphere or communicated with the intake passage that injects fuel.
According to this configuration, the pressure fluctuation in the intake passage can be corrected with respect to the fuel pressure on the upstream side (fuel chamber) of the injection valve, and a predetermined amount of fuel can be stably injected with high accuracy.

The above configuration includes a pressure sensor that detects the pressure of the fuel in the fuel passage or the fuel chamber, and a control unit that drives and controls the plunger pump and the injection valve. The control unit is configured to control the plunger pump and the injection based on a signal from the pressure sensor. A configuration for driving and controlling the valve can be employed.
According to this configuration, the plunger pump and the injection valve are driven and controlled by the control means in accordance with the signal from the pressure sensor (in accordance with the fuel pressure in the fuel chamber or the fuel passage). Thus, it is possible to pressurize the fuel (drive the plunger pump) and inject the fuel (drive the injection valve) without waste. Therefore, fuel can be efficiently pressurized and converted into kinetic energy with the minimum necessary energy, and the necessary fuel can be injected while atomizing at the optimal timing, improving engine combustion and improving fuel efficiency. Can do.

  According to the fuel injection device having the above configuration, the structure is simplified, the device is downsized, the pipeline loss is reduced, the energy efficiency is improved, the spray is refined, the spray shape is stabilized, and the like. A fuel injection device capable of obtaining the injection characteristics can be obtained.

1 is a system diagram showing a fuel injection system including a fuel injection device according to the present invention. It is sectional drawing which shows the fuel-injection apparatus contained in the fuel-injection system shown in FIG. It is a system diagram which shows the other fuel-injection system containing the fuel-injection apparatus which concerns on this invention. It is sectional drawing which shows the fuel-injection apparatus contained in the fuel-injection system shown in FIG.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, a fuel injection system including a fuel injection device of the present invention has an intake pipe 1 that defines an intake passage 1 a of an engine E, a throttle valve 2 disposed in the intake passage 1 a, and a throttle valve 2. A fuel injection device M attached to the intake pipe 1 on the downstream side, a supply pipe 4 for guiding the fuel in the fuel tank 3 to the fuel injection device M, a low-pressure filter 5 disposed in the middle of the supply pipe 4, and the fuel injection device M; A return pipe 6 is connected to the fuel tank 3 to return excess fuel to the fuel tank 3.

  Further, as shown in FIG. 2, the fuel injection device M includes a body 10, a plunger pump 20 (including a plunger 21, a coil 22, a return spring 23, a check valve 24) provided integrally with the body 10, The injection valve 30 (including the valve body 31, the coil 32, the return spring 33, etc.) provided integrally with the body 10 is disposed between the plunger pump 20 and the injection valve 30, and is pressurized by the plunger pump 20. A fuel storage unit 40 that stores fuel (including a fuel chamber 41, a moving member 42, a back pressure chamber 43, and an urging spring 44), a pressure sensor 50 that is attached to the body 10 and detects the pressure of the stored fuel, and a plunger An ECU 60 and the like are provided as control means for driving and controlling the pump 20 and the injection valve 30.

As shown in FIG. 2, the body 10 has a fuel supply connector 11, a fuel return connector 12, a pump housing portion 13, a fuel passage 14, an injection valve housing portion 15, a seating portion 16, an injection port 17, and a fuel passage 14. A check valve 18 provided, a magnetic member (not shown) for forming a magnetic path, and the like are provided.
The fuel supply connector 11 is formed so as to define a supply passage 11 a and to connect the supply pipe 4.
The fuel return connector 12 is formed so as to define a return passage 12 a and connect the return pipe 6.
The pump accommodating portion 13 accommodates the plunger 21 so as to reciprocate in the axis S direction and accommodates the coil 22 fixed at a predetermined position.
The fuel passage 14 is formed so as to extend on the axis S (on the same axis as the plunger 21) so that the plunger pump 20 (the pressurizing chamber C thereof) and the injection valve 30 (the fuel passage 31a thereof) communicate with each other. .
The injection valve accommodating portion 15 accommodates the valve body 31 so as to reciprocate in the axis S direction and accommodates the coil 32 in a fixed position.
The seating portion 16 is formed so that the valve body 31 is seated to block the passage, and the valve body 31 is detached to open the passage.
A plurality of (for example, annularly and radially arranged) injection ports 17 are provided on the downstream side of the seating portion 16 on which the valve body 31 is seated.
As shown in FIG. 2, the check valve 18 includes a valve body 18a and a biasing spring 18b that biases the valve body 18a in the valve closing direction. The check valve 18 prevents the fuel pressurized by the plunger pump 20 and fed into the fuel passage 14 from flowing back upstream.

As shown in FIG. 2, the plunger pump 20 includes a plunger 21 that reciprocates in the axis S direction, an excitation coil 22, a return spring 23 that returns the plunger 21 to a predetermined rest position, a check valve 24, and the like. Yes.
As shown in FIG. 2, the plunger 21 is formed in a cylindrical shape with a flange, and defines an introduction passage 21 a that guides the fuel guided from the fuel tank 3 through the supply passage 11 a to the pressurizing chamber C on the axis S thereof. is doing.
The coil 22 is formed so as to generate an electromagnetic driving force that moves the plunger 21 to the upstream side (upward in FIG. 2) in cooperation with a magnetic member that forms a magnetic path when energized.
The return spring 23 is disposed so as to urge the plunger 21 downstream in the axis S direction (the direction in which the pressurizing chamber C is compressed).
The check valve 24 includes a valve body 24a and a biasing spring 24b that biases the valve body 24a in the valve closing direction. The check valve 24 opens the introduction passage 21a when the plunger 21 moves upstream against the urging force of the return spring 23 by energizing the coil 22, and supplies the fuel to the pressurizing chamber C. The lead-in passage 21a is closed when the coil 22 is turned off and the energization of the coil 22 is cut off and the plunger 21 moves downstream by the biasing force of the return spring 23.
That is, in the plunger pump 20, the coil 21 is energized to the upstream side (upward in FIG. 2), the fuel is sucked into the pressurizing chamber C, and the coil 22 is deenergized. The plunger 21 moves to the downstream side (downward in FIG. 2) by the urging force of the return spring 23, so that the fuel in the pressurizing chamber C is pressurized and discharged toward the fuel passage 14. .

As shown in FIG. 2, the injection valve 30 includes a valve body 31 that reciprocates in the direction of the axis S, an excitation coil 32, a return spring 33 that returns the valve body 31 to a predetermined rest position, and the like.
As shown in FIG. 2, the valve body 31 defines a fuel passage 31 a through which the fuel guided to the fuel passage 14 (and the fuel chamber 41) passes on the axis S.
The coil 32 is formed so as to generate an electromagnetic driving force that moves the valve element 31 to the upstream side (upward in FIG. 2) in cooperation with a magnetic member that forms a magnetic path when energized.
The return spring 33 is arranged to urge the valve body 31 downstream in the axis S direction so as to be seated (closed) on the seat portion 16.
That is, in the injection valve 30, the energization of the coil 32 causes the valve element 31 to move upstream (upward in FIG. 2) and open, and the fuel pressurized in the fuel passage 14 and the fuel chamber 41. Is injected from the injection port 17 (through the fuel passage 31a), and on the other hand, the valve body 31 moves downstream (downward in FIG. 2) by the urging force of the return spring 33 after the power supply to the coil 32 is cut off. By closing the valve, the injection is stopped.

  As shown in FIG. 2, the fuel reservoir 40 defines a fuel chamber 41 communicating with the fuel passage 14, a part of the wall surface of the fuel chamber 41, and moves in the direction of the axis S so as to change the volume of the fuel chamber 41. The moving member 42, the back pressure chamber 43 cut off from the fuel chamber 41 via the moving member 42, and the biasing disposed in the back pressure chamber 43 to bias the moving member 42 in the direction of reducing the volume of the fuel chamber 41. A biasing spring 44 as a member, and a communication passage 45 that communicates the back pressure chamber 43 with the pump housing portion 13 and the low pressure fuel portion of the return passage 12a are provided.

As shown in FIG. 2, the fuel chamber 41 is formed so as to communicate with the fuel passage 14 on the axis S (on the same axis as the plunger 21).
That is, the fuel chamber 41 and the fuel passage 14 are arranged coaxially with the plunger pump 20. As a result, the fuel pressurized and discharged by the plunger pump 20 is directly guided to the fuel passage 14 and the fuel chamber 41 located on the upstream side of the injection valve 30, so that there is little fuel flow path loss and the plunger pump 20 It is possible to improve the energy efficiency in the pumping action, and to simplify the structure, reduce the number of parts, reduce the size of the apparatus, and the like.
As shown in FIG. 2, the moving member 42 is configured to block the fuel chamber 41 and the back pressure chamber 43 and to be movable in the direction of the axis S to change the volume of the fuel chamber 41. .
The back pressure chamber 43 accommodates the biasing spring 44 and is formed to allow the movement of the moving member 42 that changes the volume of the fuel chamber 41.
As shown in FIG. 2, the urging spring 44 is disposed in the back pressure chamber 43 and is formed so as to urge the moving member 42 in the direction of decreasing the volume of the fuel chamber 41 (downward in FIG. 2). Has been.
The communication passage 45 is formed so as to return the fuel or vapor leaked into the back pressure chamber 43 to the return passage 12a.

In the fuel storage section 40, the moving member 42 is urged by the urging spring 44 to reduce the volume of the fuel chamber 41, that is, the fuel stored in the fuel chamber 41 (and the fuel passage 14) is constantly added. It comes to be pressed.
That is, even if the fuel stored in the fuel chamber 41 and the fuel passage 14 decreases due to the fuel injection by the injection valve 30, the moving member 42 is biased by the biasing spring 43 so that the volume of the fuel chamber 41 is reduced. Since the fuel stored in the fuel chamber 41 is constantly pressurized, a predetermined amount of fuel can be injected stably (without variation) at a desired timing, and the atomization of the spray can be reduced. Stabilization, reduction of air pollution, etc. can be achieved. Further, compared to the conventional technique in which the pressurized fuel is returned to the fuel tank 3, there is less loss when the pressurized energy is converted into kinetic energy, and energy efficiency can be improved. Furthermore, since the plunger pump 20, the injection valve 30, the fuel passage 14, and the fuel storage part 40 are formed integrally with the body 10, simplification of the structure, size reduction of the apparatus, and the like can be achieved. .

As shown in FIG. 2, the pressure sensor 50 is attached to the body 10 so as to detect the pressure of the fuel in the fuel passage 14 and the fuel chamber 41.
The pressure sensor 50 outputs a detected fuel pressure signal to a detection circuit in the ECU 60.

The ECU 60 (control means) generates various control signals based on various information for controlling the operation of the engine, and controls the driving of the plunger pump 20 based on various signals including the signal from the pressure sensor 50 ( A drive circuit that performs energization control of the coil 22, a drive circuit that performs drive control of the injection valve 30 (energization control of the coil 32) based on various signals including the signal of the pressure sensor 50, other drive circuits, and various controls A storage circuit for storing information is provided.
That is, the ECU 60 controls the plunger pump 20 and the injection valve 30 according to the signal from the pressure sensor 50 (according to the fuel pressure in the fuel chamber 41 or the fuel passage 14), so that a desired timing is obtained when necessary. Therefore, it is possible to pressurize the fuel (drive the plunger pump 20) and inject the fuel (drive the injection valve 30) without waste.
Therefore, it is possible to efficiently pressurize the fuel with the minimum necessary energy and convert it into kinetic energy, and to inject it while atomizing the necessary fuel at the optimum timing, improving the combustion of the engine E and improving the fuel efficiency. be able to.

Next, the operation and drive control of the fuel injection device M will be described.
First, in the resting state, the plunger 21 stops at the downward movement end in FIG. 2, and the valve body 31 stops at the downward movement end in FIG. 2 (sits on the seating portion 16 and closes the valve).
In this state, when the coil 22 is energized, the plunger 21 moves forward (ascends in FIG. 2), sucks fuel into the pressurizing chamber C, and when the coil 22 is de-energized, the return spring. The fuel is moved back by the urging force of 23 (lowered in FIG. 2), and the fuel in the pressurizing chamber C is pressurized and fed into the fuel passage 14 and the fuel chamber 41 on the downstream side.
The fuel fed into the fuel chamber 41 is constantly pressurized to a predetermined level of pressure by the moving member 42 that is constantly urged in the direction of reducing the volume of the fuel chamber 41.

  In this state, when the coil 32 is energized at a desired timing, the valve element 31 moves forward (ascends in FIG. 2) and opens, and fuel is injected from the injection port 17 into the intake passage 1a. The During the injection, even if the fuel in the fuel chamber 41 is reduced, the fuel stored in the fuel chamber 41 is reduced so that the moving member 42 is biased by the biasing spring 44 and the volume of the fuel chamber 41 is reduced. Since it is constantly pressurized, it is possible to stably inject a predetermined amount of fuel at a desired timing, and to achieve atomization of the spray, stabilization of the spray shape, reduction of air pollution, and the like. Further, compared to the conventional technique in which the pressurized fuel is returned to the fuel tank 3, there is less loss when the pressurized energy is converted into kinetic energy, and energy efficiency can be improved.

  In this drive control, the plunger pump 20 and the injection valve 30 are appropriately driven and controlled based on the signal from the pressure sensor 50, that is, the fuel pressure in the fuel chamber 41 or the fuel passage 14 has become a predetermined level or less. By controlling so that the plunger pump 20 is driven only in the case, unnecessary driving can be omitted, and when the engine is operated at a low load, the injection valve 30 is used for one discharge amount of the plunger pump 20. Since the injection amount is small, the injection valve 30 can be driven a plurality of times and the injection can be performed a plurality of times while the plunger pump 20 is not driven. In particular, during idle operation, the plunger pump 20 can be driven and controlled to set the fuel pressure higher to promote atomization of the spray.

3 and 4 show another embodiment of the fuel injection device according to the present invention. In this embodiment, the back pressure chamber 43 ′ of the fuel reservoir 40 ′ is communicated with the intake passage 1 a and is the same as the above-described embodiment except that the parts are partially changed. Are denoted by the same reference numerals and description thereof is omitted.
In this embodiment, a fuel injection system including a fuel injection device includes an intake pipe 1 that defines an intake passage 1a of an engine E, a throttle valve 2 disposed in the intake passage 1a, and a throttle valve 2 as shown in FIG. The fuel injection device M ′ attached to the intake pipe 1 on the downstream side, the supply pipe 4 for guiding the fuel in the fuel tank 3 to the fuel injection device M ′, the low pressure filter 5 arranged in the middle of the supply pipe 4, the fuel A return pipe 6 for connecting the injection device M ′ and the fuel tank 3 to return excess fuel to the fuel tank 3, and a communication pipe 7 for connecting the back pressure chamber 43 ′ of the fuel injection device M ′ to the intake passage 1 a are provided. Yes.

  As shown in FIG. 4, the fuel injection device M ′ includes a body 10 and a plunger pump 20 ′ provided integrally with the body 10 (including a plunger 21 ′, a coil 22, a return spring 23, a check valve 24, etc.). The injection valve 30 (including the valve body 31, the coil 32, the return spring 33, etc.) provided integrally with the body 10 is disposed between the plunger pump 20 ′ and the injection valve 30, and is added by the plunger pump 20 ′. Fuel storage section 40 'for storing pressurized fuel (including fuel chamber 41', moving member 42 ', back pressure chamber 43', biasing spring 44, cap 46 having connector 46a), pressure sensor 50, ECU 60, etc. It has.

As shown in FIG. 3, the plunger pump 20 ′ includes a plunger 21 ′, a coil 22, a return spring 23, and a check valve 24. The plunger 21 ′ is formed in a cylindrical shape without wrinkles, and its axis S An introduction passage 21a is defined above.
As shown in FIG. 3, the fuel reservoir 40 ′ defines a fuel chamber 41 ′ communicating with the fuel passage 14, a part of the wall surface of the fuel chamber 41 ′, and an axis S for changing the volume of the fuel chamber 41 ′. A diaphragm-type moving member 42 ′ that moves in a direction perpendicular to the back surface, a back pressure chamber 43 ′ that is cut off from the fuel chamber 41 ′ via the moving member 42 ′, and a moving member 42 that reduces the volume of the fuel chamber 41 ′. A biasing spring 44 as a biasing member disposed in the back pressure chamber 43 ′ to bias ′, and a connector 46 a that is fixed to the body 10 to define the back pressure chamber 43 and connects the communication pipe 7. A cap 46 and the like are provided.

In the fuel storage section 40 ′, the moving member 42 ′ is urged by the urging spring 44 to reduce the volume of the fuel chamber 41 ′, that is, stored in the fuel chamber 41 ′ (and the fuel passage 14). Fuel is constantly pressurized.
That is, even if the fuel stored in the fuel chamber 41 ′ and the fuel passage 14 decreases due to the fuel injection by the injection valve 30, the moving member 42 ′ is urged by the urging spring 44 and the volume of the fuel chamber 41 ′ is increased. Since the fuel stored in the fuel chamber 41 ′ is constantly pressurized so as to be small, a predetermined amount of fuel can be injected stably (with no variation) at a desired timing, and fine spraying can be performed. , Stabilization of spray shape, reduction of air pollution, etc. can be achieved. Further, compared to the conventional technique in which the pressurized fuel is returned to the fuel tank 3, there is less loss when the pressurized energy is converted into kinetic energy, and energy efficiency can be improved. Furthermore, since the plunger pump 20 ′, the injection valve 30, the fuel passage 14, and the fuel storage portion 40 ′ are formed integrally with the body 10, the structure can be simplified, the apparatus can be downsized, and the like. Can do.
In this embodiment, since the back pressure chamber 43 ′ communicates with the intake passage 1 a via the communication pipe 7, the intake pressure is increased with respect to the fuel pressure upstream of the injection valve 30 (fuel chamber 41 ′). The pressure fluctuation in the passage 1a can be corrected, and a predetermined amount of fuel can be stably injected with high accuracy.
Note that the operation and drive control of the fuel injection device M ′ are the same as those in the above-described embodiment, and thus description thereof is omitted.

In the above embodiment, the moving member 42 that moves in the direction of the axis S and the moving member 42 ′ that moves in the direction perpendicular to the direction of the axis S are shown as the moving members that form part of the fuel reservoirs 40, 40 ′. However, the present invention is not limited to this, and it is also possible to adopt one that is movable in other directions and is urged in the direction of reducing the volume of the fuel chamber.
Moreover, in the said embodiment, although the biasing spring 44 arrange | positioned in the back pressure chambers 43 and 43 'was shown as a biasing member which biases the moving members 42 and 42', it is not limited to this. Alternatively, a biasing member such as a tension spring that is disposed in the fuel chamber and biases the moving member may be employed.
In the above embodiment, the case where the back pressure chamber 43 ′ of the fuel storage unit 40 ′ is communicated with the intake passage 1 a is shown, but the present invention is not limited to this, and the back pressure chamber 43 ′ is opened to the atmosphere. However, the same effect can be obtained.

  As described above, the fuel injection device of the present invention achieves simplification of structure, downsizing of the device, reduction of pipeline loss, improvement of energy efficiency, refinement of spray particle size, stabilization of spray shape, etc. However, since stable injection characteristics can be obtained, it can be applied to a small engine such as a two-wheeled vehicle, and is useful not only for a two-wheeled vehicle but also for an engine such as an outboard motor or a general-purpose machine.

E Engine 1 Intake pipe 1a Intake passage 2 Throttle valve 3 Fuel tank 4 Low pressure filter 5 Supply pipe 6 Return pipe 7 Communication pipe M, M 'Fuel injector 10 Body 11 Fuel supply connector 11a Supply path 12 Fuel return connector 12a Return path 13 Pump accommodating portion 14 Fuel passage 15 Injection valve accommodating portion 16 Seating portion 17 Injection port S Axis C Pressurizing chamber 20, 20 'Plunger pump 21, 21' Plunger 21a Introduction passage 22 Coil 23 Return spring 24 Check valve 24a Valve element 24b Energizing spring 30 Injection valve 31 Valve element 31a Fuel passage 32 Coil 33 Return springs 40, 40 'Fuel reservoirs 41, 41' Fuel chambers 42, 42 'Moving members 43, 43' Back pressure chamber 44 Energizing spring (urging) Element)
45 Communication path 46 Cap 46a Connector 50 Pressure sensor 60 ECU (control means)

Claims (4)

A plunger pump that pressurizes fuel by an electromagnetically driven plunger; an injection valve that is electromagnetically driven to inject fuel pressurized by the plunger pump; and a fuel passage that communicates the plunger pump and the injection valve; A fuel injection device that integrally includes a fuel reservoir that communicates with the fuel passage and stores fuel pressurized by the plunger pump,
The fuel reservoir includes a fuel chamber communicating with the fuel passage, a moving member that defines a part of the wall surface of the fuel chamber and moves to change the volume of the fuel chamber, and the moving member via the moving member. A back pressure chamber cut off from the fuel chamber; and a biasing member that biases the moving member in a direction to reduce the volume of the fuel chamber.
The fuel-injection apparatus characterized by the above-mentioned. The fuel chamber and the fuel passage are arranged coaxially with the plunger pump.
The fuel injection device according to claim 1. The back pressure chamber is open to the atmosphere or communicated with an intake passage for injecting fuel.
The fuel injection device according to any one of claims 1 to 3, wherein A pressure sensor for detecting the pressure of the fuel in the fuel passage or the fuel chamber, and a control means for driving and controlling the plunger pump and the injection valve;
The control means drives and controls the plunger pump and the injection valve based on a signal from the pressure sensor.
The fuel injection device according to any one of claims 1 to 3, wherein

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