JP2003083202A - Fuel injection valve - Google Patents

Abstract

(57) [Problem] To provide a fuel injection valve capable of accurately controlling a lift amount and a valve opening time of a needle valve. When a lift amount of a needle valve is zero, an injection hole is closed and fuel is not injected.
The amount of fuel injected from the injection hole 101 increases as the lift amount increases, and the amount of fuel injected is determined by the lift amount of the needle valve 4. , Means 26 for detecting a change in magnetic flux of the magnet 21.
A change in the lift amount of the needle valve 4 is obtained from the change in the magnetic flux detected by the control unit 6, and the operation of the needle valve 4 is controlled based on the obtained change in the lift amount.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fuel injection valve.

[0002]

2. Description of the Related Art A fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine is disclosed in US Pat. No. 5,779,149. This fuel injection valve is a common rail type fuel injection valve, and a piezoelectric actuator is used to open and close the injection valve of the fuel injection valve. Since the piezoelectric actuator has a very small expansion / contraction amount, even if the piezoelectric actuator is connected to the injection valve so that the expansion / contraction amount of the piezoelectric actuator directly becomes the lift amount of the injection valve, the injection valve is hardly lifted. Therefore, the fuel injection valve has a large-diameter piston and a small-diameter piston fluidly connected between the piezoelectric actuator and the injection valve. The expansion amount of the piezoelectric actuator is amplified by these pistons, and the lift amount of the injection valve can be increased even if the expansion amount of the piezoelectric actuator is small.

Further, the fuel injection valve disclosed in the above patent publication is provided with a check valve for supplying fuel into the chamber between the large diameter piston and the small diameter piston. By this check valve, even if the fuel in the chamber leaks from the small diameter piston, the fuel is supplied into the chamber and the pressure of the fuel in the chamber is kept constant. This allows
Compensation for chamber dimensional tolerances, assembly errors, and temperature changes.

[0004]

By the way, in the fuel injection valve disclosed in the above patent publication, the expansion and contraction of the piezoelectric actuator causes the injection valve to be opened through various components including the chamber and fuel. It The path from the expansion and contraction of the piezoelectric actuator to the opening of the injection valve is complicated, and there are many uncertain factors such as the temperature of the inflowing fuel. Therefore, merely compensating the error in the chamber cannot accurately control the lift amount and the valve opening time of the needle valve by changing the voltage applied to the piezoelectric actuator. If the lift amount and the valve opening time of the needle valve cannot be accurately controlled, the amount of fuel injected from the fuel injection valve cannot be grasped, and the operation of the internal combustion engine will be affected.

Therefore, an object of the present invention is to provide a fuel injection valve capable of accurately controlling the lift amount and valve opening time of a needle valve.

[0006]

In order to solve the above problems, in the first invention, when the lift amount of the needle valve is zero, the injection hole is closed and fuel is not injected, and the lift amount of the needle valve is reduced. In the fuel injection valve in which the amount of fuel injected from the injection hole increases as the value of V increases, and the amount of fuel injected is determined by the lift amount of the needle valve, the magnet disposed in the needle valve and the magnetic flux change of the magnet are changed. A means for detecting the change in the lift amount of the needle valve is obtained from the change in the magnetic flux detected by the means, and the operation of the needle valve is controlled based on the obtained change in the lift amount. That is, the change in the lift amount of the needle valve obtained from the change in magnetic flux is fed back for controlling the operation of the needle valve.

According to a second invention, in the first invention, a cylinder for providing a valve body for controlling the operation of the needle valve and a seat for accommodating the valve body and seating the valve body is provided. A body having the same, another body providing another seat for seating the valve body, and only the two bodies so as to align the two seats and the valve body in a predetermined relationship And a ring that holds the The ring causes the two bodies to be accurately aligned, which in turn causes the two sheets to be accurately aligned.

According to a third aspect of the present invention, in the first aspect, an actuator for controlling the operation of the valve body is further provided, and the actuator is provided with a centering mechanism. By providing the actuator with the centering mechanism as described above, the actuator is prevented from being eccentric.

According to a fourth aspect of the present invention, in the first aspect, the centering mechanism adjusts the tilt of the shaft of the actuator and a spacer ring arranged around one end of the actuator via a cushion ring. And an axial tilt adjusting mechanism arranged at the other end of the actuator.

In a fifth aspect based on the first aspect, the valve body is actuated by an actuator via a large-diameter piston, and a load applied to the large-diameter piston by a spring for urging the large-diameter piston. An eccentric load reduction mechanism is provided to reduce the eccentricity. As a result, the bias of the load applied to the large diameter piston by the spring is reduced.

According to a sixth aspect of the present invention, in the first aspect of the present invention, a spring for urging the needle valve is provided with an eccentric load reducing mechanism for reducing a bias of a load applied to the needle valve.

In the seventh invention, a high-pressure volume space for holding fuel under high pressure, a medium-pressure volume space for holding fuel under medium-pressure, a low-pressure volume space for holding fuel under low-pressure, and a high-pressure space A high pressure side through hole connecting the volume space and the medium pressure volume space, a low pressure side through hole connecting the medium pressure volume space and the low pressure volume space, a high pressure side pin accommodated in the high pressure side through hole, and a low pressure side A low-pressure side pin housed in the through hole, the medium-pressure volume space is connected to the high-pressure volume space via the fuel introduction passage of the high-pressure side pin, and the medium-pressure volume space forms a fuel discharge passage of the low-pressure side pin. First intermediate pressure is generated in the medium pressure volume space by the flow resistance of the fuel introduction passage and the fuel discharge passage.
In the fuel injection valve of the invention described above, the high pressure side region of the high pressure side pin is press-fitted into the high pressure side through hole, the high pressure side region of the low pressure side pin is press fit into the low pressure side through hole, and the fuel introduction passage is connected to the high pressure side pin. An annular groove formed at the low pressure side end of the high pressure side region, and an introduction groove communicating the annular groove with the high pressure volume space,
An annular space formed between the low pressure side region of the high pressure side pin and the inner wall surface of the high pressure side through hole, and the fuel discharge passage is formed at the low pressure side end of the high pressure side region of the low pressure side pin. It comprises an annular groove, an introduction groove that communicates the annular groove with the medium pressure volume space, and an annular space formed between the low pressure side region of the low pressure side pin and the inner wall surface of the low pressure side through hole. In the embodiments described later, the element forming the high-pressure volume space is, for example, the high-pressure introducing passage (114), the element forming the medium-pressure volume space is, for example, the intermediate pressure chamber (135), and forming the low-pressure volume space. The element to perform is, for example, the low-pressure fuel passage (143).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an embodiment of a fuel injection valve adopting the present invention. The fuel injection valve of this embodiment is used to directly inject fuel into the combustion chamber of a diesel engine.
However, the fuel injection valve of the present invention can also be used to directly inject fuel into the combustion chamber of an internal combustion engine that is not a diesel engine, or to inject fuel into an engine intake passage connected to the combustion chamber. It can also be used.

FIG. 1 is a sectional side view of an embodiment of the fuel injection valve of the present invention. In FIG. 1, the fuel injection valve 1 is basically a retainer 2, a cover 3, a first body 10, and a second body 1.
1, a third body 12, a fourth body 13 and a fifth body 14 are provided. The bodies 10 to 14 have a substantially cylindrical shape, and the retainer 2 holds the bodies 10 to 14 so that the bodies 10 to 14 are substantially coaxial. Hereinafter, in FIG. 1, the side where the first body 10 is arranged is referred to as the lower side, and the side where the fifth body 14 is arranged is referred to as the upper side. Therefore, the bodies 10 to 14 are arranged from the bottom to the top in the order of the first body 10, the second body 11, the third body 12, the fourth body 13, and the fifth body 14. However, when using the fuel injection valve of this embodiment, it is not always necessary to arrange the fuel injection valve so that the first body 10 is on the lower side, and the fuel injection valve may be used in any orientation.

An injection hole 101 for injecting fuel is formed in the first body 10 at a lowermost protruding portion of the first body 10. The injection hole 101 communicates with a needle valve receiving chamber 102 formed in the first body 10. The needle valve 4 is housed in the needle valve receiving chamber 102 so as to be vertically slidable. When the needle valve 4 is at the lowermost position within the slidable range, that is, when the lift amount of the needle valve 4 is at the position of zero, the injection hole 101 is closed and the injection hole 1 is closed.
No fuel is injected from 01. Needle valve 4
Is lifted from the position where the lift amount is zero, the injection hole 10
1 is opened, and fuel is injected from the injection hole 101. At this time, the fuel injection amount injected from the injection hole 101 changes according to the lift amount of the needle valve 4. That is,
The fuel injection amount injected from the injection hole 101 per unit time is substantially proportional to the lift amount of the needle valve 4. Therefore, as the lift amount of the needle valve 4 increases, the injection hole 1
The fuel injection amount from 01 increases.

A fuel reservoir 103 is formed near the axial center of the needle valve receiving chamber 102. High-pressure fuel is always held in the fuel pool 103, and when the needle valve 4 is lifted, the fuel held in the fuel pool 103 passes through the space between the needle valve 4 and the inner wall surface of the needle valve receiving chamber 102. And is ejected from the injection hole 101. Further, the fuel sump 103 includes the first body 10 and the second body 1.
1, through the high pressure fuel passage 6 formed in the third body 12, the fourth body 13, and the fifth body 14, to communicate with the high pressure fuel inlet 141 formed in the fifth body 14, and thus, in the fuel sump 103. High-pressure fuel is supplied from this high-pressure fuel inlet 141.

A shoulder that faces upward is formed around the middle of the needle valve 4 in the axial direction. One end of the first spring 22 is placed on this shoulder via a first centering ring 23 and a second centering ring 24. First alignment ring 2
The third and second centering rings 24 are rings having a substantially trapezoidal cross section and each have a spherical surface and a conical surface. The centering rings 23 and 24 are arranged so that the spherical surface and the conical surface face each other. . The other end of the first spring 22 is placed on the second body 11 via the stopper plate 28. The stopper plate 28 is an annular plate arranged in the second body 11 around the magnet chamber 111 described later. Therefore, the needle valve 4 is biased downward by the first spring 22. The first spring 22 is housed in the control chamber 104 formed in the first body 10.

A magnet 21 is mounted above the needle valve 4 coaxially with the needle valve 4, and the magnet 21 moves up and down as the needle valve 4 moves up and down. The magnet 21 extends upward beyond the first body 10 and is housed in a magnet chamber 111 formed in the second body 11. The magnet chamber 111 includes the magnet 2
1 extends upward from the lower surface of the second body 11 through the center of the stopper plate 28 so that the magnet 21 can be accommodated even when the needle valve 4 moves up and down together with the needle valve 4. As shown in FIG. 2, the magnet 21 is surrounded by the magnet 21.
The magnetic lines of force 51 are generated by. Also, the second body 1
A bobbin 25 is provided above the first body 11 around the longitudinal axis of the second body 11. The bobbin 25 is a member having a low magnetic permeability having an I-shaped cross section, and a detection coil 26 is wound around the bobbin 25. Then, as shown in FIG.
The magnetic force line 51 generated by passes through the center of the detection coil 26. Since the magnet 21 works with the needle valve 4,
When the needle valve 4 moves up, the magnet 21 also moves upward together. As the magnet 21 moves upward, the detection coil 2
The magnetic flux density of the magnetic force lines 51 passing through the inside 6 changes, and this change in magnetic flux density is detected by the detection coil 26. From the change in the magnetic flux density detected by the detection coil 26, the magnet 21
Can be calculated, and the position of the magnet 21, that is, the position of the needle valve 4 can be always grasped by integrating the amount of movement of the magnet 21. The data of the magnetic flux density detected by the detection coil 26 is the ECU
(Electronic control unit; not shown) or a control device provided for each fuel injection valve.

The control chamber 104 described above is connected to a valve chamber 136 formed in the fourth body 13 through an orifice passage 112 formed in the second body 11 and a valve chamber passage 123 formed in the third body 12. Communicate. The valve chamber 136 is a substantially cylindrical space, and the upper portion thereof has a substantially conical shape. In addition, the valve chamber 136 is the same as the valve chamber 1 in the fourth body 13.
36, a space formed on the side of 36, an inflow orifice 122 formed in the third body 12, and an inflow orifice passage 12
1, and communicates with the high-pressure fuel passage 6. Therefore, the high pressure fuel is supplied to the valve chamber 136 from the high pressure fuel inlet 141 via the inflow orifice passage 121. A substantially spherical valve element 32 is arranged in the valve chamber 136, and the valve element 32 can move in the valve chamber 136 along the longitudinal axis of the valve chamber 136. The inflow orifice 122 has an inner diameter smaller than that of other passages such as the inflow orifice passage 121.

Further, the upper part of the valve chamber 136 communicates with the outflow volume 131 formed in the fourth body 13 through the passage at the top of its conical shape. The outflow volume 131 is a substantially cylindrical space that is open above the fourth body 13, and the cylindrical small-diameter piston 31 slides in the outflow volume 131 along the longitudinal axis of the outflow volume 131. Be arranged so that The lower side portion of the outflow volume 131 communicates with an outflow passage 132 formed in the third body 13, and the outflow passage 132 is connected to the low pressure fuel outlet 142 via the low pressure fuel 143 formed in the fifth body 14. It is in communication. Therefore, the lower side of the outflow volume 131 is below the low-pressure fuel outlet 14.
2 and communicates with the low pressure fuel outlet to discharge fuel. Therefore, the low pressure fuel is supplied to the lower side of the small diameter piston 31 arranged in the outflow volume 131. The upper side of the outflow volume 131 is in communication with the intermediate pressure outlet passage 133 via the check valve body 33, so that it is generated in the outflow volume 131 and above the small diameter piston 31 as described later. Intermediate pressure fuel is supplied. In addition, the check valve body 33 has the intermediate pressure outlet passage 133.
Is a check valve that prevents the fuel from flowing from the outflow volume 131 to the intermediate pressure outlet passage 133 while flowing the fuel from the outflow volume 131 to the outflow volume 131. Therefore, the large-diameter piston 40 passes through the gap between the small-diameter piston 31 and the outflow volume 131 from the upper side to the lower side of the small-diameter piston 31 or passes through the gap between the large-diameter piston 40 and the actuator chamber 146 described later. Even if the fuel leaks from below to above, the pressure of the fuel supplied between the small diameter piston 31 and the large diameter piston 40 by the check valve body 33 is maintained at the intermediate pressure.

The small-diameter piston 31 is connected to the valve body 32 via a rod-shaped portion extending between the valve body 32 and the small-diameter piston 31, and the valve body 32 is driven by the hydraulic pressure in the valve chamber 136 and the valve chamber passage 123. Is biased in the direction of. Therefore, the small diameter piston 31 and the valve body 32 move in the same direction in the outflow volume 131 and the valve chamber 136 by the same amount. When the valve body 32 is at the uppermost position in its movement range, that is, when the lift amount of the valve body 32 is zero, the valve body 32 has an upper seat 138 (see FIG. 5) formed in a conical portion of the valve chamber 136. Placed in
The passage between the outflow volume 131 and the valve chamber 136 is sealed. Therefore, in this case, the unsealed valve chamber passage 123 and the inflow orifice passage 121 communicate with each other. Further, when the valve body 32 is at the lowermost position in its movement range,
That is, when the lift amount of the valve body 32 is maximum, the valve body 32
Is mounted on the lower end portion of the valve chamber 136, that is, the lower seat 125 (see FIG. 5) formed on the third body 12, and seals the valve chamber passage 123. Therefore, in this case, the passage to the outflow volume 131 which is not sealed and the inflow orifice 121 communicate with each other.

A large-diameter piston 40 is arranged above the small-diameter piston 31 via intermediate pressure fuel. Large piston 4
0 has a T-shaped cross section and is a shape in which columnar members are stacked, and the radius thereof is larger than the radius of the small diameter piston 31. The large-diameter piston 40 is arranged in the actuator chamber 146 formed in the fifth body 14 so as to be slidable along the longitudinal axis of the actuator chamber 146. The actuator 5 is arranged in the actuator chamber 146 above the large-diameter piston 40. In this embodiment, the actuator 5 is a piezoelectric element that is distorted according to the applied voltage.

The lower end of the actuator 5 has a large-diameter piston 4
0 is in contact with the upper end of the actuator 5, and the upper end of the actuator 5 is covered by the aligning block 37 and aligning plate 36.
Placed on. Therefore, due to the strain of the actuator 5 generated according to the voltage applied to the actuator 5,
The large-diameter piston 40 is lifted downward or returned upward. A spacer ring 38 and a plurality of cushion rings 39 are arranged between the actuator 5 and the fifth body 14 on the side of the actuator 5.

A shoulder facing downward is formed above the T-shaped large-diameter piston 40 in the axial direction. In this shoulder, one end of the second spring 42 accommodated in the low pressure spring chamber 144, which is a space between the fifth body 14 formed in the actuator chamber 146 and the large diameter piston 40, is It is placed via the third alignment ring 43 and the fourth alignment ring 44. Third alignment ring 43 and fourth alignment ring 4
Similar to the first centering ring 23 and the second centering ring 24, 4 is a ring having a substantially trapezoidal cross section and has a spherical surface and a conical surface, respectively. The faces are arranged so that they face each other. Also,
The other end of the second spring 42 is placed on a shoulder formed on the fifth body 14. Therefore, the large-diameter piston 40 and the actuator 5 are biased upward by the second spring 42. The low-pressure spring chamber 144 communicates with the low-pressure fuel outlet 142 via the low-pressure discharge passage 145, so that the low-pressure spring chamber 144 is always filled with the low-pressure fuel.

The second body 11 is formed with a high pressure side through hole 115 which is radially separated from the axis of the second body 11 and extends in the longitudinal direction of the fuel injection valve 1. The lower end of the high pressure side through hole 115 communicates with the high pressure fuel passage 6 formed in the second body 11 via the high pressure side introduction passage 114. Therefore, the high pressure fuel is introduced into the lower end portion of the high pressure side through hole 115. The upper end of the high-pressure side through hole 115 is provided with a second body 11 through a passage 124 formed in the third body 12.
To the intermediate pressure chamber 135 formed in. The high voltage side pin 27 is inserted into the high voltage side through hole 115 as described later. Further, the fourth body 13 is formed with a low pressure side through hole 137 which is radially separated from the axis of the fourth body 13 and extends in the longitudinal direction of the fuel injection valve 1. The lower end of the low pressure side through hole 137 communicates with the intermediate pressure chamber 135. Therefore, the intermediate pressure fuel is introduced into the lower end of the low pressure side through hole 137. The upper end of the intermediate pressure side through hole 137 communicates with the low pressure fuel outlet 142 via the low pressure fuel passage 143 formed in the fifth body 14. The low voltage side pin 34 is inserted into the low voltage side through hole 137.

Further, the third body 12 and the fourth body 1
The cylindrical coaxial peripheral ring 35 is arranged on both outer peripheral surfaces of the cylindrical member 3. By disposing the coaxial peripheral ring 35 in this manner, the coaxial peripheral ring 35 can be arranged in the third body 12 and the fourth body 1.
Accurately determine the relative position with respect to 3.

Next, the operation of the fuel injection valve 1 of the present invention will be described with reference to FIGS. 1 and 2. Here, first
The operation of the valve element 32 will be described. When a voltage is applied to the actuator 5, the actuator 5 is distorted and presses the large-diameter piston 40 downward. When the large-diameter piston 40 is pressed downward due to the strain of the actuator 5, the intermediate-pressure fuel between the large-diameter piston 40 and the small-diameter piston 31 acts as a hydraulic pressure to move the small-diameter piston 31 downward. At this time, since the diameter of the large diameter piston 40 is larger than the diameter of the small diameter piston 31, the lift amount of the small diameter piston 31 is larger than the lift amount of the large diameter piston 40. Generally, the strain amount of the actuator 5, especially the piezoelectric element, is very small, but the lift amount can be amplified by changing the size of the piston in this way. Next, since the small diameter piston 31 and the valve body 32 are connected while receiving hydraulic pressure, when the small diameter piston 31 is lifted, the valve body 32 is also lifted. From the above,
It can be seen that the actuator 5 and the valve body 32 are interlocked, and the lift amount of the valve body 32 is larger than the strain amount of the actuator 5.

Next, the operation of the needle valve 4 will be described. When no voltage is applied to the actuator 5,
That is, a schematic diagram of the fuel injection valve 1 when the lift amount of the valve body 32 is zero is shown in FIG. Here, the valve body 32 is the valve chamber 1
It is located above 36 and seals the passage between the valve chamber 136 and the outflow volume 131. Therefore,
The inflow orifice passage 121 and the valve chamber passage 123 communicate with each other, and the high pressure fuel flowing from the high pressure fuel passage 6 into the valve chamber 136 is filled in the control chamber 104, that is, above the needle valve 4. Further, high-pressure fuel is directly introduced from the high-pressure fuel passage 6 below the needle valve 4. In this way, the high-pressure fuel is introduced both above and below the needle valve 4, so that the needle valve 4 is urged downward by the first spring to close the injection hole 101 and prevent fuel injection.

When a voltage is applied to the actuator 5 to slightly distort the actuator 5, that is, the valve body 32
3 (b) is a schematic view of the fuel injection valve 1 when the lift amount of the valve is medium and the valve body 32 is substantially in the center of the valve chamber 136.
Shown in. Here, all three passages leading to the valve chamber 136, that is, the passage from the outflow volume 131, the inflow orifice passage 121, and the valve chamber passage 123 are open to the valve chamber 136. However, since the inflow orifice 122 is provided in the inflow orifice passage 121, the amount of high-pressure fuel flowing into the valve chamber 136 from the high-pressure fuel passage 6 is limited. Therefore, the pressure of the fuel in the valve chamber 136 is lowered, and the valve chamber 136 is filled with the low pressure fuel. Accordingly, the control chamber 104 communicating with the valve chamber 136 via the valve chamber passage 123 is also filled with the low pressure fuel. At this time, since the orifice 113 is formed between the valve chamber passage 123 and the control chamber 104, the pressure of the fuel in the control chamber 104 gradually decreases.

When the inside of the control chamber 104 is filled with the low pressure fuel in this manner, a pressure difference is generated between the upper side and the lower side of the needle valve 4 because the lower side of the needle valve 4 is filled with the high pressure fuel. Due to the pressure difference between the upper and lower sides of the needle valve 4, the needle valve 4 rises against the first spring 22. Needle valve 4
Rises, the injection hole 101 is opened, and the high-pressure fuel flowing into the fuel pool 103 through the high-pressure fuel passage 6 is injected into the injection hole 101.
Is jetted from. The needle valve 4 continues to rise to the maximum lift position where the upper end of the needle valve 4 contacts the stopper plate 28 while the lift amount of the valve body 32 is medium.

A schematic view of the fuel injection valve 1 when the voltage applied to the actuator 5 is maximized, that is, when the lift amount of the valve body 32 is maximum and the valve body 32 seals the valve chamber passage 123 is shown. It is shown in FIG. In order for the lift amount of the valve body 32 to be maximized, the state in which the lift amount of the valve body 32 shown in FIG. That is, at the time when the lift amount of the valve body 32 is maximized and the valve body 32 seals the valve chamber passage 123, the needle valve 4 is elevated from the position where the lift amount is zero or the position where the lift amount is maximized. is there. When the lift amount of the needle valve 4 is maximum, even if the valve body 32 seals the valve chamber passage 123, the fuel in the control chamber 104 and the valve chamber passage 123 remains at a low pressure, so that the position of the needle valve 4 is The position of the maximum lift remains unchanged. When the needle valve 4 rises above the position where the lift amount is zero at the time when the valve body 32 seals the valve chamber passage 123, the control chamber 104 and the valve chamber are closed at the moment when the valve body 32 seals the valve chamber passage 123. Since the fuel in the passage 123 has a low pressure, the needle valve 4 continues to rise. When the needle valve 4 continues to rise, the pressure of fuel in the control chamber 104 and the valve chamber passage 123 gradually increases. Then, the force due to the pressure difference between the fuel pressure in the control chamber 104, which is gradually increased, that is, the pressure above the needle valve 4 and the pressure of the high-pressure fuel below the needle valve 4, causes the first spring 22 to move. The needle valve 4 stops rising at a point balanced with the urging force. Therefore, the rise of the needle valve 4 stops after some time lag after the lift amount of the valve element 32 becomes maximum.

Fuel injection when the voltage applied to the actuator 5 is made zero, that is, when the lift amount of the valve body 32 is returned to zero and the valve body 32 seals the passage with the outflow volume 131 again. A schematic diagram of the valve 1 is shown in FIG. When the lift amount of the valve element 32 is returned to zero, the high pressure fuel flows from the high pressure fuel passage 6 into the control chamber 104 via the inflow orifice passage 121, the valve chamber 136 and the valve chamber passage 123, and the needle valve 4 High-pressure fuel is introduced both above and below. In this way, the needle valve 4 is urged downward by the first spring and the lift amount becomes smaller, and eventually the lift amount becomes zero and the injection hole 101 is closed, so that fuel is not injected from the injection hole 101. It should be noted that if the lift amount of the valve body 32 is set to a medium level or the maximum amount immediately after the lift amount is set to zero, the lift amount of the needle valve 4 does not become zero and the needle valve 4 is again set.
Can be raised or the needle valve 4 can be stopped while the injection hole 101 is open.

As described above, the valve body 32 is lifted by zero,
The needle valve 4 can be controlled as desired by moving it in various combinations between the three positions of medium lift amount and maximum lift amount. Further, when the lift amount of the valve body 32 is medium, the lift speed of the needle valve 4 can be changed according to the position of the valve body 32 in the valve chamber 136. That is, when the lift amount of the valve body 32 is very small or when the lift amount of the valve body 32 is slightly smaller than the maximum, the ascending speed of the needle valve 4 becomes slow, and the valve body 32 is substantially centered in the valve chamber 136. When located at, the lift speed of the needle valve 4 increases.

The control of the above-described fuel injection valve 1 of the present invention will be described with reference to FIG. In the graph of FIG. 4, the x-axis shows time, and the y-axis shows the drive voltage of the actuator 5 and the lift amount of the needle valve 4. In the figure, (a) to (a) shown in the graph of the drive voltage of the actuator 5
3D corresponds to the drive voltage of the actuator 5 in FIGS. 3A to 3D, respectively.

First, the simplest first control pattern of the fuel injection valve 1 will be described. In the control pattern shown in FIG. 4A, the voltage is not applied to the actuator 5 before the fuel injection is started, the lift amount of the needle valve 4 is zero, and the fuel injection valve 1 is shown in FIG. It is in the state shown. Therefore, fuel is not injected from the fuel injection valve 1. Then, first, a voltage is applied to the actuator 5. The voltage applied at this time is an intermediate voltage such that the lift amount of the valve element 32 becomes medium, as shown in FIG. When a voltage is applied to the actuator 5, the valve body 32 is lowered by a medium amount, and the pressure of the fuel in the control chamber 104 is lowered, so that the needle valve 4 is released after a slight time lag after the voltage is applied to the actuator 5. Ascends and fuel is injected from the injection hole 101. When the needle valve 4 rises and the lift amount of the needle valve 4 reaches the target value, the voltage applied to the actuator 5 is changed from the intermediate voltage to the maximum lift amount of the valve body 32 as shown in FIG. Change to the maximum voltage. The needle valve 4 stops rising after a certain time lag after the lift amount of the valve element 32 is maximized. At this time, the needle valve 4 remains open at the position where the lift amount is medium and the fuel is continuously injected. After the fuel injection, if the voltage applied to the actuator 5 is set to zero, the lift amount of the valve element 32 becomes zero and the pressure of the fuel in the control chamber 104 becomes high. The lift amount of the needle valve 4 also becomes zero after the time lag of. The descending speed of the needle valve 4 when the needle valve 4 is closed is faster than the ascending speed of the needle valve 4 when the needle valve 4 is opened.

FIG. 4B shows the second control pattern of the needle valve 4. In the control method shown in FIG. 4B, the voltage of the actuator 5 is changed to the maximum voltage shown in FIG.
A voltage is applied to the actuator 5 in the same manner as the control method shown in FIG. That is, the intermediate voltage is applied to the actuator 5 from the state where the voltage applied to the actuator 5 is zero and the lift amount of the needle valve 4 is zero. Then, after a certain time lag, the needle valve 4 starts to rise and fuel is injected from the injection hole 101. When the lift amount of the needle valve 4 reaches the target value, the maximum voltage is applied to the actuator 5. After some time lag after applying the maximum voltage to the actuator 5, the rise of the needle valve 4 stops, the needle valve 4 remains open at that position, and fuel continues to be injected. Then, after a predetermined time elapses after the needle valve 4 has stopped rising, the intermediate voltage is applied to the actuator 5 again. The needle valve 4 starts to rise again after some time lag after applying the intermediate voltage to the actuator 5. If the intermediate voltage is applied to the actuator 5 as it is, the lift amount of the needle valve 4 is maximized, the lift of the needle valve 4 is stopped, and the fuel injection amount is maximized. After the fuel injection, the voltage applied to the actuator 5 is set to zero, and after a slight time lag, the needle valve 4
Lift amount becomes zero and one cycle of fuel injection ends. Such a fuel injection pattern is called boot injection, and is the injection pattern most often used in diesel engines.

FIG. 4C shows the third control pattern of the needle valve 4. In the control method shown in FIG. 4C, first, when the voltage applied to the actuator 5 is zero, the needle valve 4
The intermediate voltage is applied to the actuator 5 from the state where the lift amount is zero. Then, after some time lag, the needle valve 4 starts to rise. If the intermediate voltage is applied to the actuator 5 as it is, the lift amount of the needle valve 4 is maximized. The applied voltage to the actuator 5 is set to zero after a predetermined time has passed since the start of applying the intermediate voltage to the actuator. This causes the needle valve 4 to start descending. When the needle valve 4 descends and reaches the target value, the maximum voltage is applied to the actuator, and after a short time lag, the needle valve 4 stops. After the fuel injection, the voltage applied to the actuator 5 is set to zero, and after some time lag, the lift amount of the needle valve 4 becomes zero and one cycle of fuel injection ends.

In the first control pattern and the second control pattern, the detected lift amount of the needle valve 4 is
It is only used to change the voltage applied to the actuator 5 from the intermediate voltage to the maximum voltage to stop the rise of the needle valve 4 and keep it at a medium lift. In this case, a lift amount slightly lower than the lift amount desired to lift the needle valve 4 at the intermediate lift position is set as the target value. The target value of the lift amount of the needle valve 4 is a predetermined value. By maximizing the voltage applied to the actuator 5 when the lift amount of the needle valve 4 reaches the target value, the needle valve 4 reaches the desired lift amount at the intermediate lift position after some time lag. Further, in the third control pattern, the voltage applied to the actuator 5 is changed from zero to the maximum voltage to stop the lowering of the needle valve 4 to determine the timing for maintaining the lift amount at the intermediate position. used. In this case, a lift amount slightly higher than the desired lift amount of the needle valve 4 at the medium lift position is set as the target value. Thus, by detecting the lift amount of the needle valve 4 and using the result for controlling the needle valve 4, the needle valve 4 can be positioned in the intermediate lift position almost accurately.

Although the target value of the lift amount of the needle valve 4 is a predetermined value, it may be a different value. For example, the lift speed of the needle valve 4 is calculated from the lift amount of the needle valve 4 with respect to time, and after the lift amount of the needle valve 4 reaches a target value from this lift speed, the lift desired to lift the needle valve 4 at a medium lift position. The target value of the lift amount of the needle valve 4 may be set by calculating the time required to reach the amount. By thus setting the target value from the lift speed, the needle valve 4 can be more accurately positioned at the intermediate lift position.

Further, in fuel injection of a certain cycle,
As described above, after the lift amount of the needle valve 4 reaches the target value, the lift amount of the valve element 32 is maximized and the lift amount of the needle valve 4 is set to an intermediate value and stopped. At this time, if the lift amount of the needle valve 4 in the fuel injection of a certain cycle is larger than the desired lift amount at the medium lift position, the target value of the lift amount of the needle valve 4 is slightly set in the fuel injection of the next cycle. If the lift amount of the needle valve 4 is smaller than the desired lift amount at the intermediate lift position in the fuel injection of a certain cycle, the target value of the lift amount of the needle valve is slightly increased in the fuel injection of the next cycle. In this way, the needle valve 4 may be feedback-controlled. By performing feedback control in this manner, the needle valve 4 can be accurately and practically positioned at the intermediate lift position.

Further, the detected lift amount of the needle valve 4 is used only for determining the timing of stopping the rise of the needle valve 4 and keeping it in the intermediate lift state. It may be used in different ways. For example, the fuel injection amount corresponding to the lift amount of the needle valve 4 is obtained in advance, and the fuel injection amount corresponding to the detected lift amount of the needle valve 4 is integrated to obtain the total fuel injection amount after starting the fuel injection. Ask for. Then, from the total fuel injection amount and the cycle of the internal combustion engine, the needle valve 4
The timing for raising, stopping, and lowering the lift may be optimally controlled. As a result, the fuel injection from the fuel injection valve 1 can be freely controlled.

The advantages of the fuel injection valve 1 of the present invention will be described. Conventionally, the valve element is generally a hemispherical shape having a flat surface on the valve chamber passage side. Therefore, when the valve body closes the valve chamber passage, the flat surface of the valve body is in surface contact with the upper end surface of the third body around the valve chamber passage. However, in this conventional valve body, when the valve body opens the valve chamber passage, in particular, when the valve body lift amount is set to a middle level so that the valve body is located in substantially the center of the valve chamber, the valve using the piezoelectric element Since the lift amount of the body is small, there is only a small gap between the flat surface of the valve body and the upper end surface of the third body, and the fuel flow path formed by the valve body and the third body is small. The shape was very difficult to flow. Therefore, even if the valve body opens the valve chamber passage, the amount of fuel flowing into the valve chamber passage or fuel flowing out from the valve chamber passage is extremely limited.

By the way, as shown in FIG. 5, the valve body 32 of the present invention has a substantially spherical shape, and when the lift amount is zero, the valve body 32 comes into contact with the upper seat 138 formed on the fourth body 13 to form the outflow volume 131. Close the passageway to the valve chamber 136,
When the lift amount is maximum, it contacts the lower seat 125 formed on the third body 12 to close the valve chamber passage 123. Here, since the valve element 32 has a spherical shape, the lift amount is increased when the valve element 32 is opened to the valve chamber passage 123, particularly when the valve element 32 is lifted moderately so as to be located substantially in the center of the valve chamber. Despite being small, the fuel passage formed by the valve body 32 and the third body 12 has a very easy flow shape. Therefore, when the valve body opens the valve chamber passage, the amount of fuel flowing into the valve chamber passage or fuel flowing out from the valve chamber passage is
The number is larger than that of a conventional hemispherical valve body. Therefore, when the valve body 32 is lifted to a medium degree, the control chamber 104
Since the amount of high-pressure fuel flowing from the valve chamber 136 through the valve chamber 136 to the outflow passage 132 increases, the rising speed of the needle valve 4 can be increased. The speed of the needle valve 4 can be adjusted by controlling the lift amount of the valve element 32 between the medium lift amount and the maximum lift amount. That is, when the lift amount of the valve body 32 is slightly larger than the medium lift amount to bring the valve body 32 slightly closer to the lower seat 125, the speed of the needle valve 4 is such that the lift amount of the valve body 32 is medium. Slightly slower than if By finely controlling the lift amount of the valve element 32 in this manner, the rising / lowering speed of the needle valve 4 can be controlled.

Here, as shown in FIG. 5, the fourth body 13 in which the valve body 32 and the small diameter piston 31 are housed.
And the third body 12 having the lower seat 125 for the valve body 32 is a separate body. Because of this, these two bodies 1
Even if 2 and 13 are slightly displaced in the direction perpendicular to the longitudinal axis of the fuel injection valve 1, when the lift amount of the valve body 32 reaches the maximum lift amount, the valve body 32 does not properly contact the lower seat 125. . In this case, the valve body 32 and the lower seat 12
No proper seal is formed between the fuel cell and the fuel cell 5, and fuel leaks. By the way, the fuel injection valve of the present invention is provided with the coaxial peripheral ring 35 arranged so as to surround the third body 12 and the fourth body 13 as shown in FIG. The coaxial peripheral ring 35 accurately maintains the relative position between the third body 12 and the fourth body 13, that is, the relative position such that the valve body 32 appropriately contacts the lower seat 125, These bodies 12, 13 are held. Therefore, the inner surface of the coaxial peripheral ring 35 and the third body 1
The outer surfaces of the second body 4 and the fourth body 13 are formed more precisely than the other parts of the fuel injection valve 1. By manufacturing the fuel injection valve 1 in this way, it is not necessary to precisely form the inner surfaces of the retainer 2 and the cover 3 and the outer surfaces of the first body 10, the fourth body 13 and the fifth body 14, and the manufacturing cost is reduced. Can be reduced.

Another advantage of the fuel injection valve 1 of the present invention will be described. As described above, when the actuator 5 is a piezoelectric element, the piezoelectric element is vulnerable to a force other than a compressive force such as a shearing force, so that there is a risk that the actuator 5 may be cracked or short-circuited if the actuator 5 is eccentric. Therefore, first, the fuel injection valve 1 of the present invention is provided with the spacer ring 38 and the cushion ring 39 around the actuator 5, as described above and shown in FIG.
The spacer ring 38 is a precisely manufactured cylindrical member, and the longitudinal axis of the cylindrical space formed therein exactly coincides with the longitudinal axis of the fifth body 12. The radius of the inner surface of the spacer ring 38 is slightly larger than the radius of the actuator 5. A number of grooves corresponding to the number of cushion rings 39 are formed on the inner surface of the spacer ring 38, and an O-ring shaped cushion ring 39 is arranged in this groove. That is, the cushion ring 39 is arranged between the groove of the spacer ring 38 and the actuator 5. The spacer ring 38 and the cushion ring 39 enable the actuator 5 to be positioned so that the axis of the actuator 5 coincides with the axis of the actuator chamber 146. That is, the spacer ring 38 and the cushion ring 39 function as a centering mechanism.

Further, in the fuel injection valve 1 of the present invention, a disc-shaped aligning block 37 is mounted above the actuator 5 and has a dome-shaped upper surface, and is arranged above the aligning block 37. Actuator chamber 146
And a disk-shaped aligning plate 36 that comes into contact with the wall surface of the disk. The aligning plate 36 has a conical recess facing downward, and the dome-shaped upper surface of the aligning block 37 abuts on this recess. These aligning block 37 and aligning plate 36
This prevents the upper side of the actuator 5 from being displaced in the direction perpendicular to the axial direction. That is, the alignment block 37 and the alignment plate 36 function as an axial tilt adjusting mechanism. Therefore, the alignment plate 36, the alignment plate 37, the spacer ring 38, and the cushion ring 39 function as a centering mechanism, so that the actuator 5 is prevented from being eccentric with respect to the longitudinal axis of the fifth body 14. It is held accurately, and there is almost no risk of cracking or short circuit of the actuator 5.

Another advantage of the fuel injection valve 1 of the present invention will be described. Generally, a spring such as a spiral spring does not uniformly apply a biasing force to an object to be biased on a biasing surface. Therefore, the object to be biased is eccentrically biased by the spring.
By the way, in the fuel injection device of the present invention, the first spring 22 urges the shoulder of the needle valve 4 via the first centering ring 23 and the second centering ring 24, and the second spring 42 is the third centering ring. The large-diameter piston 40 is urged via the ring 43 and the fourth alignment ring 44. The first centering ring 23 and the second centering ring 24, and the third centering ring 43 and the fourth centering ring 44 are rings having a substantially trapezoidal cross section and have a spherical surface and a conical surface, respectively. As shown in FIG. 1, the spherical surface and the conical surface are arranged so as to face each other. With these alignment rings 23, 24, 43, 44,
The eccentricity of the first spring 22 with respect to the shoulder of the needle valve 4 and the eccentricity of the second spring 42 with respect to the shoulder of the large-diameter piston 40 are compensated, and thus the deviation of the load applied to the needle valve 4 and the large-diameter piston 40 is reduced. That is, the centering rings 23 and 24 and the centering rings 43 and 44.
Respectively function as an unbalanced load reducing mechanism. As a result, the needle valve 4 and the large-diameter piston 40 are biased in the axial direction of the first body 10 and the axial direction of the fifth body 14, respectively.

Another advantage of the fuel injection valve 1 of the present invention will be described. As described above, the high voltage side pin 27 is inserted into the high voltage side through hole 115 of the second body 11.
As shown in FIG. 6, the high-voltage side pin 27 has an annular groove 271 substantially at the center in the longitudinal direction, and further below the annular groove 271, that is, on the high-pressure side, on the outer periphery of the high-pressure side pin 27, the high-voltage side pin 27 is located. It has an introduction groove 272 extending in the longitudinal direction. The introduction groove 272 is provided to guide the high pressure fuel to the annular groove 271. The high pressure side pin 27 has a dimensional tolerance of 2 to 6 μm on the high pressure side of the annular groove 271 and the high pressure side through hole 1
It is press-fitted in 15. For example, the fuel injection pressure is 180 MPa
When the diameter of the high-pressure side through hole 115 expands by about 2 μm (when the pin diameter is 2 mm), when the high-pressure side pin 27 is not press-fitted as described above, the high pressure in the high-pressure side through hole 115 is high. The side pin 27 is eccentric, and the flow coefficient of fuel leakage increases by a maximum of 2.5 times compared to the case where it is not eccentric. However, by press-fitting as described above, the high pressure side pin 27 is positioned at the high pressure side through hole At the center of 115, the flow coefficient of fuel leakage becomes stable. Further, the high-voltage side pin 27 is located above the annular groove 271, that is, between the high-voltage side pin 27 and the high-voltage side through hole 115 on the low-pressure side.
It is formed with a size that allows a diameter clearance (annular space) of 3 μm. This can reduce leakage of high-pressure fuel that passes through the diameter clearance.
The annular groove 271, the introduction groove 272 and the diameter clearance formed in the high pressure side pin 27 form a fuel introduction passage. In addition, the introduction groove 2 for easy lapping
In place of 72, the introduction groove 27 is provided at approximately the center of the high voltage side pin 27.
It is also possible to form a hole extending in the same manner as 2 and further form a horizontal hole at the height of the annular groove 271 so as to communicate with this hole and introduce the high pressure fuel into the annular groove 271.

As described above, the low voltage side pin 34 is inserted into the low voltage side through hole 137. The low-voltage side pin 34, like the high-voltage side pin 27, has the annular groove 3 substantially at the center in the longitudinal direction.
41, and further has an introduction groove 342 below the annular groove 341, that is, on the outer circumference of the low pressure side pin 34 on the intermediate pressure side and extending in the longitudinal direction of the low pressure side pin 34. The introduction groove 342 is provided to guide the intermediate pressure fuel to the annular groove 341. Further, the low-pressure side pin 34 is formed in a size that allows a diameter clearance of 2 to 3 μm on the intermediate pressure side of the annular groove 341 so as to reduce the influence of eccentricity. It should be noted that, here, since it is not possible to selectively fit the low-voltage side pin when press-fitting, it is formed so as to have a diameter clearance. Further, on the upper side of the annular groove 341, that is, on the low pressure side, the low pressure side pin 34 and the low pressure side through hole 137.
It is formed in such a size that a diameter clearance of 9 to 10 μm can be provided between and. This diametral clearance is adjusted so that the intermediate pressure becomes an appropriate pressure for the high pressure fuel. In addition, the annular groove 341 formed in the low voltage side pin 34,
The introduction groove 342 and the diameter clearance form a fuel introduction passage. By the high-pressure side pin 27 and the low-pressure side pin 34, more specifically, by the diameter clearance of the high-pressure side pin 27 and the diameter clearance of the low-pressure side pin, the fuel pressure in the intermediate pressure chamber 135 becomes higher than that of the high-pressure fuel and the low-pressure fuel. It becomes an intermediate pressure which is a proper pressure between and. The amount of fuel leaked from the diameter clearance is proportional to the pin diameter / pin length (clearance length),
It is proportional to the cube of the diameter clearance. Although the leakage amount is inversely proportional to the viscosity coefficient, the high pressure side pin 27 and the low pressure side pin 34 are in substantially the same temperature environment, and therefore do not affect the intermediate pressure set value. In this manner, the high pressure side pin 27 and the low pressure side pin 34 can set an appropriate intermediate pressure.

[0050]

According to the first aspect of the present invention, the change in the lift amount of the needle valve is obtained from the change in the magnetic flux detected by the means for detecting the change in the magnetic flux of the magnet. By controlling the operation, it becomes possible to accurately control the lift amount and the valve opening time of the needle valve.

According to the second aspect of the present invention, the first sheet and the second sheet are accurately aligned so that a seal is formed between these sheets even if a spherical valve element is used. Like

According to the third aspect of the invention, since the actuator is prevented from being eccentric, the actuator is not cracked or short-circuited.

According to the fifth aspect of the invention, the bias of the load applied to the large-diameter piston by the spring is reduced, so that the friction between the large-diameter piston and the actuator chamber is reduced.

[Brief description of drawings]

FIG. 1 is a sectional side view of an embodiment of a fuel injection valve of the present invention.

FIG. 2 is an enlarged view of a magnet and a detection coil provided in an embodiment of the fuel injection valve of the present invention.

FIG. 3 is a diagram showing an operation of the embodiment of the fuel injection valve shown in FIG. 1.

FIG. 4 is a diagram showing three injection patterns of the fuel injection valve of the present invention.

FIG. 5 is an enlarged view of a valve body of the fuel injection valve of the present invention.

FIG. 6 is an enlarged view of a low pressure side pin or a high pressure side pin of the fuel injection valve of the present invention.

[Explanation of symbols]

1 ... Fuel injection valve 2 ... Retainer 3 ... Cover 4 ... Needle valve 5 ... Actuator 21 ... Magnet 26 ... Detection coil 27 ... High-voltage side pin 31 ... Small diameter piston 32 ... Valve 34 ... Low-voltage side pin 40 ... Large-diameter piston

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 51/06 F02M 51/06 GN 61/12 61/12 65/00 306 65/00 306C 308 308 ( 72) Inventor Kenji Oshima 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Yoshimasa Watanabe 1 Toyota-cho, Toyota-shi, Aichi (72) Inventor Omae Kazuhiro 1st Toyota-cho, Toyota-shi, Aichi F-term in Toyota Motor Corporation (reference) 3G066 AA02 AD07 BA51 CC06T CC06U CC08U CC14 CC51 CC64U CC70 CD10 CD25 CE13 CE27 DA01 DC06

Claims (7)

[Claims] 1. When the lift amount of the needle valve is zero, the injection hole is closed and fuel is not injected, and as the lift amount of the needle valve increases, the fuel amount injected from the injection hole increases and the needle valve In the fuel injection valve in which the amount of fuel to be injected is determined by the lift amount, a magnet arranged in the needle valve and a means for detecting a magnetic flux change of the magnet are provided, and the magnetic flux change detected by the means. A fuel injection valve in which the change in the lift amount of the needle valve is calculated from the above, and the operation of the needle valve is controlled based on the calculated change in the lift amount. 2. A valve body for controlling the operation of the needle valve, a body having a cylinder for accommodating the valve body and providing a seat for seating the valve body, and the seating body for the valve body. A separate body for providing a separate seat for the valve and a ring that holds only the two seats together to align the two seats and the valve body in a predetermined relationship. 1. The fuel injection valve according to 1. 3. The fuel injection valve according to claim 1, further comprising an actuator for controlling the operation of the valve element, wherein the actuator is provided with a centering mechanism. 4. The centering mechanism is arranged on one end of the actuator via a cushion ring and a spacer ring on the other end of the actuator to adjust the tilt of the actuator shaft. 4. The fuel injection valve according to claim 3, further comprising an axial tilt adjusting mechanism. 5. The unbalanced load reduction for reducing the deviation of the load applied to the large-diameter piston by a spring for urging the large-diameter piston, wherein the valve element is actuated by an actuator via the large-diameter piston. The fuel injection valve according to claim 3, further comprising a mechanism. 6. The fuel injection valve according to claim 1, wherein a spring for urging the needle valve is provided with an eccentric load reducing mechanism for reducing a bias of a load applied to the needle valve. 7. A high pressure volume space for holding fuel under high pressure, an intermediate pressure volume space for holding fuel under medium pressure, a low pressure volume space for holding fuel under low pressure, and a high pressure volume space. A high pressure side through hole connecting the pressure volume space, a low pressure side through hole connecting the medium pressure volume space and the low pressure volume space, a high pressure side pin housed in the high pressure side through hole, and a low pressure side through hole. A medium pressure volume space is connected to the high pressure volume space via the fuel introduction passage of the high pressure side pin, and the medium pressure volume space has a low pressure volume via the fuel discharge passage of the low pressure side pin. The fuel injection valve according to claim 1, wherein the fuel injection valve is connected to a space, and an intermediate pressure is generated in the medium pressure volume space by the flow resistance of the fuel introduction passage and the fuel discharge passage. When pressed into the side through hole The high pressure side region of the low pressure side pin is press-fitted into the low pressure side through hole, and the fuel introduction passage has an annular groove formed at the low pressure side end of the high pressure side region of the high pressure side pin, and the annular groove and the high pressure volume space. The fuel discharge passage includes a communication groove and an annular space formed between the low pressure side region of the high pressure side pin and the inner wall surface of the high pressure side through hole, and the fuel discharge passage has a low pressure in the high pressure side region of the low pressure side pin. It is formed between an annular groove formed at a side end portion, an introduction groove communicating the annular groove with the medium pressure volume space, a low pressure side region of the low pressure side pin and an inner wall surface of the low pressure side through hole. Fuel injection valve consisting of an annular space that