JP2010096071A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device which is reduced in size and allows control valves to be operated with good response by a small drive force of an actuator. <P>SOLUTION: The second control valve 23 is moved forward to a second control valve second position by a load from the actuator 24 to flow a high-pressure fuel from a fourth fuel passage 44 to a first control valve back pressure chamber 14 via a second fuel storage chamber 21 and a fifth fuel passage 45. When the first control valve 13 is moved forward to a first control valve second position by the fuel pressure in the first control valve back pressure chamber 14, the fuel flows out from a needle valve back pressure chamber 34 to a third fuel passage 43 via a second fuel passage 42 and a first fuel storage chamber 11. Since a needle valve 33 is retreated by the fuel pressure in a third fuel storage chamber 31, and is separated from a nozzle body 2, the fuel in the third fuel storage chamber 31 is injected through a nozzle hole 5. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection device. Specifically, the present invention relates to a fuel injection device that is used in a diesel engine and injects fuel supplied at a high pressure from a fuel supply source.

  Conventionally, a fuel injection device that injects fuel is used for a diesel engine. In such a fuel injection device, the opening and closing operation of the needle valve for switching between fuel injection and stop is performed by controlling the pressure in the back pressure chamber of the needle valve. The control of the back pressure is performed by a control valve that switches the passage leading to the back pressure chamber to selectively communicate with a high pressure passage or a low pressure passage.

Here, the control valve communicates the back pressure chamber to the low pressure passage by being displaced by a piezoelectric actuator, for example (see, for example, Patent Document 1). As a mechanism for amplifying the load and displacement by the actuator, it has been proposed to use a displacement enlarging mechanism that combines a large-diameter piston and a small-diameter piston (for example, see Patent Document 2).
JP 09-184463 A JP 2002-195446 A

  However, in the device of Patent Document 1, a large displacement is required for the actuator for switching the control valve, and a large load is necessary for maintaining the displacement against the high pressure. Further, in the device of Patent Document 2, the displacement of the actuator can be enlarged, but a complicated mechanism for enlargement is required, so that the device becomes large. Furthermore, since the apparatus (enlargement mechanism) is interposed between the actuator and the control valve in the apparatus of Patent Document 2, there is a concern that the response of the control valve drive to the actuator drive may be reduced.

  An object of the present invention is to provide a fuel injection device that can be miniaturized and can operate a control valve with high responsiveness by a small driving force of an actuator.

  The fuel injection device of the present invention includes a nozzle body having a nozzle hole formed at a tip thereof, a first fuel storage chamber formed in the nozzle body, and a first control valve holding portion formed in the nozzle body. A first control valve that is held and is capable of advancing and retracting the first fuel storage chamber, and a first control valve back pressure that is disposed on the opposite side of the first fuel storage chamber across the first control valve holding portion A second control chamber that is held in a chamber, a second fuel storage chamber formed in the nozzle body, and a second control valve holder formed in the nozzle body, and is capable of advancing and retracting the second fuel storage chamber. A valve, an actuator disposed on the opposite side of the second fuel storage chamber across the second control valve holding portion, a third fuel storage chamber formed in the nozzle body, and the nozzle body The third fuel storage chamber is held by the formed needle valve holding portion. A needle valve that can be advanced and retracted, a needle valve back pressure chamber disposed on the opposite side of the third fuel storage chamber across the needle valve holding portion, and a fuel supply source (for example, a common rail 51 described later) from the first 3 a high pressure fuel passage leading to the fuel storage chamber, a first fuel passage communicating the first fuel storage chamber and the high pressure fuel passage, and a first communication passage connecting the first fuel storage chamber and the needle valve back pressure chamber. A second fuel passage, a third fuel passage communicating with the first fuel storage chamber and an external low pressure portion (for example, a fuel tank 52 described later), and a communication between the second fuel storage chamber and the high pressure fuel passage. A fourth fuel passage, a fifth fuel passage communicating the second fuel storage chamber and the first control valve back pressure chamber, and a sixth fuel passage communicating the second fuel storage chamber and the external low pressure portion. And the needle valve includes a back pressure chamber in the needle valve Loaded in the forward direction by the fuel pressure, moved forward, the tip of the needle valve seated on the nozzle body, moved backward and separated from the nozzle body, so that the third fuel storage chamber and the nozzle hole Switching between shut-off and communication, the first control valve is loaded in the forward direction by the fuel pressure in the first control valve back pressure chamber, and moves forward to the second position of the first control valve, whereby the first fuel storage chamber And the first fuel passage are shut off and retracted to the first position of the first control valve to shut off the first fuel storage chamber and the third fuel passage, and the second control valve is connected to the actuator. By being driven in the forward direction by the driving force and moving forward to the second position of the second control valve, the second fuel storage chamber and the sixth fuel passage are shut off and retracted to the second position of the second control valve. The second fuel The fuel storage chamber and the fourth fuel passage are shut off.

  According to the present invention, the operation of the fuel injection device is as follows. Fuel compressed to high pressure is supplied from the fuel supply source to the high-pressure fuel passage. In this state, when the second control valve is advanced to the second position of the second control valve by the load from the actuator, the second fuel storage chamber and the sixth fuel passage are shut off, and the second fuel storage chamber and the second fuel control chamber 5 The fuel passage communicates. Therefore, high-pressure fuel flows from the fourth fuel passage through the second fuel storage chamber and the fifth fuel passage into the first control valve back pressure chamber, and the fuel pressure in the first control valve back pressure chamber rises. Then, the first control valve advances to the second position of the first control valve due to the fuel pressure in the first control valve back pressure chamber, so that the first fuel storage chamber and the first fuel passage are shut off, and the first The fuel storage chamber communicates with the third fuel passage. Therefore, the fuel flows out from the needle valve back pressure chamber through the second fuel passage and the first fuel storage chamber to the third fuel passage, and the fuel pressure in the needle valve back pressure chamber decreases. For this reason, the needle valve moves backward due to the fuel pressure in the third fuel storage chamber and moves away from the nozzle body. As a result, the fuel in the third fuel storage chamber is injected from the injection hole.

  On the other hand, when the load input from the actuator is stopped and the second control valve is retracted to the second position of the second control valve, the second fuel storage chamber and the fourth fuel passage are shut off, and the second fuel storage chamber The sixth fuel passage communicates with the sixth fuel passage. Therefore, the fuel flows out from the first control valve back pressure chamber through the fifth fuel passage and the second fuel storage chamber to the sixth fuel passage, and the fuel pressure in the first control valve back pressure chamber decreases. Then, the first control valve moves back to the first position of the first control valve due to the pressure difference between the first control valve back pressure chamber and the first fuel storage chamber, so that the first fuel storage chamber and the third fuel passage are The first fuel storage chamber and the first fuel passage communicate with each other while being blocked. Therefore, high pressure fuel flows from the first fuel passage through the first fuel storage chamber and the second fuel passage into the needle valve back pressure chamber, and the fuel pressure in the needle valve back pressure chamber rises. For this reason, the needle valve advances by the fuel pressure in the needle valve back pressure chamber. As a result, the needle valve is seated on the nozzle body, and fuel injection stops.

  Thus, the first control valve moves forward or backward depending on the fuel pressure in the first control valve back pressure chamber switched by the second control valve. That is, the displacement of the actuator can be converted to the switching of the fuel pressure, and the first control valve can be moved greatly. Furthermore, when the second control valve is advanced to shut off the low pressure passage, it is not necessary to counter the high pressure, so that the fuel pressure in the first control valve back pressure chamber can be controlled by a small load of the actuator. That is, a large displacement and load can be generated for the first control valve by a simple means called a three-way valve (second control valve) without using a complicated mechanism. As a result, the fuel injection device can be downsized, and the first control valve can be operated with good responsiveness by the small driving force of the actuator.

  In the fuel injection device of the present invention, in the first control valve, a pressure receiving area that receives a pressure in the forward direction from the first control valve back pressure chamber fuel, and a pressure in the reverse direction from the fuel in the first fuel storage chamber. It is preferable that it be formed to be larger than the pressure receiving area.

  According to the present invention, when high-pressure fuel flows into the first control valve back pressure chamber while the first control valve is in the first position of the first control valve, the fuel in the first control valve back pressure chamber moves forward. The force received is greater than the force received in the backward direction. Accordingly, a forward force acts on the first control valve. That is, since the first control valve quickly moves forward to the first position of the first control valve, the fuel pressure in the needle valve back pressure chamber can be quickly reduced and the fuel injection response can be improved.

  In addition, the fuel injection device of the present invention preferably includes an elastic member (for example, a spring 15 described later) that biases the first control valve in the backward direction.

  According to the present invention, the first control valve moves backward more quickly to the first position of the first control valve. Therefore, it is possible to quickly increase the fuel pressure in the needle valve back pressure chamber and improve the responsiveness to stop fuel injection.

  According to the present invention, the fuel injection device can be downsized, and the control valve can be operated by a small driving force of the actuator.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of a fuel injection device 1 according to the present embodiment. In addition, in the following FIGS. 1-4, the positional relationship of each valve, the dimension of each part, etc. are exaggerated and simplified for easy understanding. Further, along with this, the illustration of the substantially cylindrical nozzle body 2 that accommodates each part is omitted.

  The fuel injection device 1 includes a nozzle body 2 having a nozzle hole 5 formed at the tip thereof, a first fuel storage chamber 11 formed in the nozzle body 2, and a first control valve holding portion formed in the nozzle body 2. The first control valve 13 held by the first control valve 13 is capable of advancing and retracting the first fuel storage chamber 11, and the first control is disposed on the opposite side of the first fuel storage chamber with the first control valve holding portion 12 in between. The valve back pressure chamber 14, the spring 15 as an elastic member that biases the first control valve 13 in the backward direction, the second fuel storage chamber 21 formed in the nozzle body 2, and the nozzle body 2 are formed. A second control valve 23 held by the second control valve holding part 22 and capable of advancing and retracting the second fuel storage chamber 21, and the opposite side of the second fuel storage chamber across the second control valve holding part 22 The piezoelectric actuator 24 and the second control valve 23 which are disposed in the direction are urged in the backward direction. Springs 25 serving as sexual members, a third fuel storage chamber 31 formed in the nozzle body 2, and a needle valve holding portion 32 formed in the nozzle body 2 to advance and retract the third fuel storage chamber 31. As a possible needle valve 33, a needle valve back pressure chamber 34 disposed on the opposite side of the third fuel storage chamber across the needle valve holding portion 32, and an elastic member for biasing the needle valve 33 in the forward direction A high pressure fuel passage 40 extending from the common rail 51 as a high pressure fuel supply source to the third fuel storage chamber 31, a first fuel passage 41 communicating the first fuel storage chamber 11 and the high pressure fuel passage 40, A second fuel passage 42 communicating with the first fuel storage chamber 11 and the needle valve back pressure chamber 34; a third fuel passage 43 communicating with the first fuel storage chamber 11 and a fuel tank 52 as an external low pressure portion; Second fuel storage A fourth fuel passage 44 that communicates with the high-pressure fuel passage 40, a fifth fuel passage 45 that communicates between the second fuel storage chamber 21 and the first control valve back pressure chamber 14, and a second fuel storage chamber 21. And a sixth fuel passage 46 communicating with the fuel tank 52.

  The common rail 51 is a portion in which high-pressure fuel compressed by a high-pressure pump (not shown) that has been pumped from the fuel tank 52 by a low-pressure pump (not shown) is stored.

  The needle valve 33 is loaded in the forward direction (the tip direction of the nozzle body 2 in which the nozzle hole 5 is formed) by the fuel pressure in the needle valve back pressure chamber 34, and is retracted by the fuel pressure in the third fuel storage chamber 31. The load is applied (in the direction of the proximal end of the needle valve 33). Then, the needle valve 33 moves forward, the tip of the needle valve 33 is seated on the nozzle body 2, moves backward and is separated from the nozzle body 2, so that the third fuel storage chamber 31 and the injection hole 5 are blocked. Switch communication. That is, when the fuel pressure in the needle valve back pressure chamber 34 increases, the needle valve 33 moves forward and sits, so that the third fuel storage chamber 31 and the injection hole 5 are shut off and fuel injection stops. On the other hand, when the fuel pressure in the needle valve back pressure chamber 34 decreases, the needle valve 33 moves backward and separates, so that the third fuel storage chamber 31 and the injection hole 5 are communicated with each other, so that fuel flows from the injection hole 5. Injected outside. The fuel pressure in the needle valve back pressure chamber 34 is controlled by the first control valve 13.

  Here, the spring 35 urges the needle valve 33 in the forward direction. Thereby, since the needle valve 33 moves forward more quickly to the seating position, the response of stopping the injection is improved. Further, the force that the needle valve 33 receives in the backward direction due to the fuel pressure in the third fuel storage chamber 31 is equal to the force that the needle valve 33 receives in the forward direction due to the fuel pressure in the needle valve back pressure chamber 34. Even so, the urging force of the spring 35 can keep the needle valve 33 in a seated state, so that there is a slight fluctuation in the fuel pressure or an external force such as an inertial force. However, it is possible to suppress erroneous fuel injection.

  The first control valve 13 is loaded in the forward direction by the fuel pressure in the first control valve back pressure chamber 14, and is loaded in the reverse direction by the fuel pressure in the first fuel storage chamber 11. When the fuel pressure in the first control valve back pressure chamber 14 rises, the first control valve 13 moves forward to the first control valve second position, which is the most advanced position, so that the first control valve 13 and the first fuel storage chamber 11 The first fuel passage 41 is blocked, and the first fuel storage chamber 11 and the third fuel passage 43 are communicated. Thereby, the needle valve back pressure chamber 34 and the low pressure fuel tank 52 communicate with each other. On the other hand, when the fuel pressure in the first control valve back pressure chamber 14 decreases, the first control valve 13 moves backward to the first control valve first position which is the last retracted position, thereby The third fuel passage 43 is blocked, and the first fuel storage chamber 11 and the first fuel passage 41 are communicated. Thereby, the needle valve back pressure chamber 34 and the high-pressure common rail 51 communicate with each other. The fuel pressure in the first control valve back pressure chamber 14 is controlled by the second control valve 23. The needle valve back pressure chamber 34 and the first fuel storage chamber 11 are always in communication with each other by the second fuel passage 42 regardless of the position of the first control valve 13.

  In the first control valve 13, the pressure receiving area S <b> 1 that receives the pressure in the forward direction from the fuel in the first control valve back pressure chamber 14 is the pressure receiving area that receives the pressure in the backward direction from the fuel in the first fuel storage chamber 11. It is formed to be larger than S2. Since the force in the forward or backward direction received by the fuel pressure is proportional to the pressure receiving area receiving the pressure, the fuel pressure in the first fuel storage chamber 11 is equal to the fuel pressure in the first control valve back pressure chamber 14. In some cases, since the area S1 is larger than the area S2, the force in the forward direction is overcome.

  Here, the spring 15 biases the first control valve 13 in the backward direction. Thereby, the 1st control valve 13 will retreat more rapidly to the 1st position of the 1st control valve. Therefore, the fuel pressure in the needle valve back pressure chamber 34 can be quickly raised, and as a result, the responsiveness of stopping fuel injection can be improved. The urging force of the spring 15 is a force in the forward direction due to the high pressure fuel pressure in the first control valve back pressure chamber 14 even if it is combined with a force in the backward direction due to the high pressure fuel pressure in the first fuel storage chamber 11. It is set so that it does not satisfy.

  The second control valve 23 is loaded in the forward direction by the driving force of the actuator 24 and is loaded in the backward direction by the biasing force of the spring 25. Then, when the driving force of the actuator 24 increases, the second control valve 23 moves forward to the second control valve second position, which is the most advanced position, thereby connecting the second fuel storage chamber 21 and the sixth fuel passage 46. The second fuel storage chamber 21 and the fifth fuel passage 45 are communicated with each other while blocking. Thereby, the first control valve back pressure chamber 14 and the high-pressure common rail 51 communicate with each other. On the other hand, when the driving force of the actuator 24 decreases, the second control valve 23 moves backward to the second control valve first position, which is the last retracted position, by the biasing force of the spring 25, thereby The fourth fuel passage 44 is shut off, and the second fuel storage chamber 21 and the sixth fuel passage 46 are communicated. Thereby, the first control valve back pressure chamber 14 and the low pressure fuel tank 52 communicate with each other. The first control valve back pressure chamber 14 and the second fuel storage chamber 21 are always in communication with each other by the fifth fuel passage 45 regardless of the position of the second control valve 23.

Next, the operation of the fuel injection device 1 that accompanies the driving of the actuator 24 will be described when fuel is injected and when it is stopped.
FIG. 2 is a diagram illustrating an operation at the time of fuel injection in the fuel injection device 1 according to the present embodiment. At the time of fuel injection, a voltage is applied to the actuator 24 based on a predetermined command signal, whereby a load input to the second control valve 23 is generated.

  By the load input to the second control valve 23, the second control valve 23 moves forward to the second position of the second control valve. As a result, the second fuel storage chamber 21 and the sixth fuel passage 46 leading to the low-pressure fuel tank 52 are shut off, and the second fuel storage chamber 21 and the fourth fuel passage 44 continuing to the high-pressure common rail 51 communicate with each other. As a result, high pressure fuel flows from the high pressure side (common rail 51) into the first control valve back pressure chamber 14 via the fourth fuel passage 44, the second fuel storage chamber 21, and the fifth fuel passage 45.

  When high pressure fuel flows into the first control valve back pressure chamber 14, the first control valve 13 moves forward in the forward direction by the high pressure fuel in the first control valve back pressure chamber 14 and the high pressure fuel in the first fuel storage chamber 11, respectively. And receive force in the backward direction. At this time, since the pressure receiving area S1 from the first control valve back pressure chamber 14 is larger than the pressure receiving area S2 from the first fuel storage chamber 11, the first control valve 13 moves forward to the first position of the first control valve. . As a result, the first fuel storage chamber 11 and the first fuel passage 41 leading to the high-pressure common rail 51 are shut off, and the first fuel storage chamber 11 and the third fuel passage 43 leading to the low-pressure fuel tank 52 communicate with each other. As a result, fuel flows out from the needle valve back pressure chamber 34 to the low pressure side (fuel tank 52) via the second fuel passage 42, the first fuel storage chamber 11, and the third fuel passage 43. The fuel pressure in the pressure chamber 34 decreases.

  When the fuel pressure in the needle valve back pressure chamber 34 decreases, the needle valve 33 moves backward due to the pressure difference from the high pressure fuel in the third fuel storage chamber 31, and is separated from the nozzle body 2 to fuel from the nozzle hole 5. Injection starts.

  FIG. 3 is a diagram illustrating an operation of stopping fuel injection in the fuel injection device 1 according to the present embodiment. When the fuel injection is stopped, the voltage applied to the actuator 24 is reduced based on a predetermined command signal, and the load input to the second control valve 23 is reduced.

  When the load input decreases, the second control valve 23 moves backward to the second control valve first position by the biasing force of the spring 25. As a result, the second fuel storage chamber 21 and the fourth fuel passage 44 leading to the high-pressure common rail 51 are shut off, and the second fuel storage chamber 21 and the sixth fuel passage 46 continuing to the low-pressure fuel tank communicate with each other. As a result, the fuel flows out from the first control valve back pressure chamber 14 to the low pressure side (fuel tank 52) via the fifth fuel passage 45, the second fuel storage chamber 21, and the sixth fuel passage 46. 1 The fuel pressure in the control valve back pressure chamber 14 decreases.

  When the fuel pressure in the first control valve back pressure chamber 14 is reduced, the pressure received in the forward direction of the first control valve 13 is weakened, so the fuel pressure in the first fuel storage chamber 11 and the biasing force of the spring 15 The first control valve 13 retracts to the first control valve first position. As a result, the first fuel storage chamber 11 and the third fuel passage 43 leading to the low-pressure fuel tank 52 are blocked, and the first fuel storage chamber 11 and the first fuel passage 41 leading to the high-pressure common rail 51 communicate with each other. As a result, high pressure fuel flows from the high pressure side (common rail 51) into the needle valve back pressure chamber 34 via the first fuel passage 41, the first fuel storage chamber 11, and the second fuel passage 42, and the needle valve back. The fuel pressure in the pressure chamber 34 increases.

  When the fuel pressure in the needle valve back pressure chamber 34 increases, the fuel pressure in the needle valve back pressure chamber 34 received by the needle valve 33 and the fuel pressure in the third fuel storage chamber 31 become equal. Then, the needle valve 33 is moved forward by the force in the forward direction from the needle valve back pressure chamber 34 having a large pressure receiving area and the urging force of the spring 35, and the needle valve 33 is seated on the nozzle body 2 to stop the fuel injection.

According to this embodiment, there are the following effects.
(1) The fuel pressure in the first control valve back pressure chamber 14 is switched by the second control valve 23 to move the first control valve 13 forward or backward. Therefore, a large displacement and load can be generated for the first control valve 13 by a simple means such as a three-way valve (second control valve 23) without using a complicated mechanism. As a result, the fuel injection device 1 can be reduced in size, and the first control valve 13 can be operated with good responsiveness by the small driving force of the actuator 24.

  (2) In the first control valve 13, a pressure receiving area S1 that receives pressure in the forward direction from the fuel in the first control valve back pressure chamber 14, and a pressure receiving area S2 that receives pressure in the backward direction from the fuel in the first fuel storage chamber 11. It was formed to be larger than. Therefore, the force received in the forward direction from the fuel in the first control valve back pressure chamber 14 is greater than the force received in the reverse direction. Accordingly, a forward force acts on the first control valve. That is, since the first control valve 13 quickly moves forward to the first position of the first control valve, the fuel pressure in the needle valve back pressure chamber 34 can be quickly reduced and the fuel injection response can be improved. .

  (3) A spring 15 that urges the first control valve 13 in the backward direction is provided. Therefore, the 1st control valve 13 will retreat more rapidly to the 1st control valve 1st position. Therefore, the fuel pressure in the needle valve back pressure chamber 34 can be quickly increased to improve the responsiveness to stop fuel injection.

In addition, this invention is not limited to the above-mentioned embodiment, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, in the present embodiment, the second control valve 23 is driven by the piezoelectric actuator 24. However, the present invention is not limited to this, and the second control valve 23 may be driven by an electromagnetic or hydraulic actuator.

  In the present embodiment, the base end side of the first control valve 13 has a planar shape. However, the present invention is not limited to this, and for example, a conical shape as shown in FIG. 4 or other shapes may be used. . In this case, the surface area where the first control valve 13 contacts the fuel in the first control valve back pressure chamber 14 is larger than the area S1. However, of the pressure received perpendicular to the surface, the component in the forward direction of the first control valve 13 decreases according to the inclination of the surface. That is, the force obtained by integrating the components in the forward direction is equal to the force in the forward direction when pressure is applied to the projection of the surface area onto the plane (area S1).

  Moreover, in this embodiment, although the fuel tank 52 was used as a low voltage | pressure part, it is not restricted to this. For example, in addition to the fuel tank 52, a fuel passage between the low pressure pump and the high pressure pump, a fuel passage upstream of the pressurizing chamber in the high pressure pump, and the like can be used as the low pressure portion.

It is a figure which shows the structure of the fuel-injection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the operation | movement at the time of the fuel injection in the fuel-injection apparatus which concerns on the said embodiment. It is a figure which shows the operation | movement which stops the fuel injection in the fuel-injection apparatus which concerns on the said embodiment. It is a figure which shows the shape of the 1st control valve which concerns on the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus 2 Nozzle body 5 Injection hole 11 1st fuel storage chamber 12 1st control valve holding part 13 1st control valve 14 1st control valve back pressure chamber 15, 25, 35 Spring (elastic member)
DESCRIPTION OF SYMBOLS 21 2nd fuel storage chamber 22 2nd control valve holding part 23 2nd control valve 24 Actuator 31 3rd fuel storage chamber 32 Needle valve holding part 33 Needle valve 34 Needle valve back pressure chamber 40 High pressure fuel passage 41 First fuel passage 42 Second fuel passage 43 Third fuel passage 44 Fourth fuel passage 45 Fifth fuel passage 46 Sixth fuel passage 51 Common rail (fuel supply source)
52 Fuel tank (low pressure part)
S1, S2 Pressure receiving area

Claims (3)

A nozzle body with a nozzle hole formed at the tip;
A first fuel storage chamber formed in the nozzle body;
A first control valve held in a first control valve holding portion formed in the nozzle body and capable of advancing and retracting the first fuel storage chamber;
A first control valve back pressure chamber disposed on the opposite side of the first fuel storage chamber across the first control valve holding portion;
A second fuel storage chamber formed in the nozzle body;
A second control valve held in a second control valve holding portion formed in the nozzle body and capable of moving back and forth in the second fuel storage chamber;
An actuator disposed on the opposite side of the second fuel storage chamber across the second control valve holding portion;
A third fuel storage chamber formed in the nozzle body;
A needle valve held in a needle valve holding portion formed in the nozzle body and capable of moving back and forth in the third fuel storage chamber;
A needle valve back pressure chamber disposed on the opposite side of the third fuel storage chamber across the needle valve holding portion;
A high-pressure fuel passage from a fuel supply source to the third fuel storage chamber;
A first fuel passage communicating the first fuel storage chamber and the high pressure fuel passage;
A second fuel passage communicating the first fuel storage chamber and the needle valve back pressure chamber;
A third fuel passage communicating the first fuel storage chamber with an external low pressure portion;
A fourth fuel passage communicating the second fuel storage chamber and the high pressure fuel passage;
A fifth fuel passage communicating the second fuel storage chamber and the first control valve back pressure chamber;
A sixth fuel passage communicating the second fuel storage chamber and the external low-pressure part,
The needle valve is loaded in the forward direction by the fuel pressure in the needle valve back pressure chamber, moves forward, the tip of the needle valve sits on the nozzle body, and moves backward to separate from the nozzle body. Switching between the communication and disconnection between the third fuel storage chamber and the nozzle hole;
The first control valve is loaded in the forward direction by the fuel pressure in the first control valve back pressure chamber, and moves forward to the second position of the first control valve, whereby the first fuel storage chamber and the first fuel passage. And the first control valve is retracted to the first position to shut off the first fuel storage chamber and the third fuel passage,
The second control valve is loaded in the forward direction by the driving force of the actuator and advances to the second position of the second control valve, thereby shutting off the second fuel storage chamber and the sixth fuel passage, 2. A fuel injection device characterized in that the second fuel storage chamber and the fourth fuel passage are shut off by retreating to the first position of the control valve.   In the first control valve, the pressure receiving area that receives pressure in the forward direction from the fuel in the back pressure chamber in the first control valve is formed to be larger than the pressure receiving area that receives pressure in the reverse direction from the fuel in the first fuel storage chamber. The fuel injection device according to claim 1.   The fuel injection device according to claim 1, further comprising an elastic member that urges the first control valve in a backward direction.

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