JP2008151043A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an externally valve-opening type fuel injection valve capable of improving seating force of a needle when opening the valve without enlarging a size of the injection valve. <P>SOLUTION: In the fuel injection valve 1 which injects or stops a high-pressure fuel of a fuel source 11, the fuel injection valve 1 has a housing 16 in which an injection hole 46 is formed, a fuel reserve chamber 48, in which the high-pressure fuel is led, communicating with the injection hole 46, a pressure control chamber 32 in which the high-pressure fuel is led, and a needle 7 which has a pressure receiving surface where pressure of the high-pressure fuel in the fuel reserve chamber 48 and pressure of the high-pressure fuel in the pressure control chamber 32 are acted and opens the injection hole 46 when the needle moves to an injection hole side by the pressure acted on the pressure receiving surface and closes the injection hole 46 when the needle moves to an anti-injection hole side. The pressure receiving surface facing the pressure control chamber 32 among the pressure receiving surfaces of the needle 7 has a first pressure receiving surface 85 which generates force to make the needle 7 move to an anti-injection hole side when the pressure of the high-pressure fuel acts in the pressure control chamber 32. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel injection valve.

  2. Description of the Related Art Conventionally, a so-called externally-open fuel injection valve that controls fuel injection and stopping by moving a valve body formed on a needle outward from an injection hole formed in a housing is known. (See Patent Document 1).

This fuel injection valve has a hydraulic control chamber that generates a force for moving the needle in the valve opening direction (hereinafter referred to as a force in the valve opening direction) at the end of the needle opposite to the injection hole, and moves the needle in the valve closing direction. And a spring for applying a force (hereinafter referred to as a force in the valve closing direction). By increasing the pressure in the pressurizing chamber, the force in the valve opening direction is increased on the needle. Fuel is injected from the injection hole.
Japanese Patent Laid-Open No. 11-351098

  In general, in order to improve the combustion efficiency of internal combustion engines and to suppress fuel consumption, the injection holes of the fuel injection valve are exposed to the combustion chamber and the fuel injected from the injection holes is atomized. Therefore, the pressure of the fuel supplied to the fuel injection valve suitable for them is relatively high. In addition, this tendency becomes stronger and the fuel pressure supplied to the fuel injection valve is higher.

  However, since the fuel injection valve having the needle of the above-described outer valve type has a structure in which the end surface on the side opposite to the injection hole of the needle simply faces the hydraulic control chamber, the fuel is supplied when fuel is supplied to the hydraulic control chamber. This pressure acts on the end face, and the needle generates only the force in the direction toward the injection hole, that is, the valve opening direction. Hereinafter, when fuel pressure is applied to various parts of the needle, the pressure receiving surface that generates force in the valve opening direction is referred to as the valve opening direction pressure receiving surface, and conversely, the pressure receiving surface that generates force in the valve closing direction is closed. It is called a direction pressure receiving surface.

  As described above, when the fuel pressure supplied to the fuel injection valve is increased, the force in the direction of opening the needle is increased. Therefore, in order to maintain the valve closing, it is necessary to increase the force in the valve closing direction.

  In addition, the injection hole side of the outer valve-opening type needle faces the fuel reservoir chamber. From the structure, a valve-opening direction pressure receiving surface and a valve-closing direction pressure receiving surface can be provided on the needle injection hole side. . According to this, force in the valve closing direction can be generated by adjusting the area of both pressure receiving surfaces of the needle.

  Here, the area of the pressure-receiving surface in the valve opening direction depends on the size of the seat diameter. Since the seat diameter is set in consideration of securing a desired injection amount, it is difficult to set the seat diameter with priority given to the force in the valve opening and closing directions as described above. That is, it is difficult to increase the force in the valve closing direction on the injection hole side of the needle.

  According to the above circumstances, in the fuel injection valve of the prior art, in order to maintain the valve closing, it is necessary to set a large biasing force of the spring biasing in the valve closing direction. The problem of increasing the size arises.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a needle at the time of valve closing without increasing the size of the injector in an externally opened fuel injector. It is providing the fuel injection valve which can improve the seat force of this.

In order to achieve the above object, according to the first aspect of the present invention, in a fuel injection valve for injecting or stopping high-pressure fuel from a fuel source, a housing having an injection hole formed at a tip thereof, an injection hole, A high-pressure fuel or high-pressure fluid different from high-pressure fuel is connected to the fuel reservoir chamber into which high-pressure fuel from a fuel source is introduced and the fuel reservoir chamber, and is provided on the side opposite to the injection hole from the fuel reservoir chamber. A pressure control chamber into which the pressure is introduced, and a pressure receiving surface in which the pressure of the high pressure fuel in the fuel reservoir chamber and the pressure of the high pressure fuel or the high pressure fluid in the pressure control chamber are applied. A fuel injection valve having a needle that opens the injection hole when moved to the injection hole side and closes the injection hole when moved to the counter-injection hole side by an acting pressure,
Among the pressure receiving surfaces of the needle, the pressure receiving surface that faces the pressure control chamber is a first pressure receiving surface that generates a force that moves the needle to the side opposite to the injection hole when the pressure of the high-pressure fuel or high-pressure fluid in the pressure control chamber acts. It is characterized by having.

  According to this configuration, in the fuel injection valve having the needle of the valve opening type, the pressure receiving surface facing the pressure control chamber among the pressure receiving surfaces formed on the needle facing the fuel reservoir chamber and the pressure control chamber is the pressure control chamber. When the pressure of the high-pressure fuel or high-pressure fluid is applied, the first pressure-receiving surface that generates a force for moving the needle to the side opposite to the injection hole is provided. The increase in the size of the physique can be suppressed, and the seating force of the needle when the valve is closed can be improved.

  According to the second aspect of the present invention, the housing is formed with an axial hole in which the needle is accommodated, and the needle is formed in the order of the axial hole from the injection hole to the fuel reservoir chamber, the pressure control chamber, and the low pressure chamber. The first pressure receiving surface faces the pressure control chamber and is disposed so as to face the injection hole.

  According to this configuration, since the first pressure receiving surface formed on the needle faces the pressure control chamber and faces the injection hole, high pressure fuel or high pressure fluid is supplied to the pressure control chamber. When a pressure is applied to the first pressure receiving surface, it is possible to generate a force that moves the needle to the side opposite to the injection hole with respect to the needle.

  According to the third aspect of the present invention, the pressure value in the pressure control chamber is equal to or higher than the pressure value in the low pressure chamber. According to this configuration, it is possible to easily generate a force for moving the needle toward the counter-injection hole with respect to the needle.

  According to a fourth aspect of the present invention, the low pressure chamber is connected to the low pressure side. According to this configuration, the pressure value in the pressure control chamber can be easily made equal to or higher than the pressure value in the low pressure chamber.

According to the fifth aspect of the present invention, the pressure receiving surface facing the fuel reservoir chamber among the pressure receiving surfaces of the needle generates a force that moves the needle toward the injection hole when the pressure of the high pressure fuel in the fuel reservoir chamber acts. The housing has a second pressure receiving surface, the housing supplies the high-pressure fuel or high-pressure fluid of the fuel source to the pressure control chamber, and discharges the high-pressure fuel from the pressure control chamber to the low-pressure side; An injection hole side connection flow path for supplying to the fuel reservoir, and a control valve chamber formed in the middle of the anti-injection hole side connection flow path,
In the control valve chamber, the anti-injection hole side connection flow path is opened and closed to control the supply of high-pressure fuel or high-pressure fluid to the pressure control chamber and the discharge of high-pressure fuel or high-pressure fluid from the pressure control chamber. It has the control valve which controls the pressure of a control room.

  According to this configuration, the pressure in the pressure control chamber can be controlled by the control valve. Thereby, the balance of force on the injection hole side or anti-injection hole side generated in the needle can be changed, and the needle can be moved arbitrarily.

  According to the sixth aspect of the present invention, the anti-injection hole side connection flow path includes the first connection flow path that always connects the fuel source and the pressure control chamber, or the high pressure fluid supply source and the pressure control chamber, and the low pressure And a pressure control chamber. The second connection flow path is controlled by a control valve so that communication or blocking between the low pressure side and the pressure control chamber is controlled.

  According to this configuration, the second connection flow path that connects the low pressure side and the pressure control chamber and is controlled by the control valve to communicate or block the low pressure side and the pressure control chamber is used as the high-pressure fuel or supply of the fuel source. Since the high-pressure fluid of the source is provided separately from the first connection flow path that can always supply the pressure control chamber, the discharge of fuel or fluid in the pressure control chamber to the low pressure side is stopped and the needle is opened When shifting from the state to the valve closing state, the pressure in the pressure control chamber can be quickly increased, and the valve closing characteristic can be improved.

  According to the seventh aspect of the present invention, when the control valve is opened, the second connection flow path is made of high-pressure fuel or high-pressure fluid that is discharged from the pressure control chamber to the low-pressure side via the second connection flow path. It is characterized in that the amount of high-pressure fuel or high-pressure fluid supplied to the pressure control chamber via the first connection flow path is smaller than the amount.

  According to this configuration, when the control valve is opened and the fuel in the pressure control chamber is discharged to the low pressure side, the amount of high pressure fuel or high pressure fluid supplied to the pressure control chamber via the first connection flow path is Since the amount of high-pressure fuel or high-pressure fluid discharged to the low-pressure side through the second connection channel is smaller, the pressure in the pressure control chamber can be easily controlled by operating the control valve.

According to the invention described in claim 8, the housing has a sub chamber connected to the control valve chamber, and a connecting flow path always connected to the fuel source or the supply source in the sub chamber,
When the control valve blocks communication between the low pressure side and the pressure control chamber, the connection flow path and the second connection flow path are connected.

  According to this configuration, when the control valve is operated to stop the discharge of the high-pressure fuel or high-pressure fluid in the pressure control chamber and the communication between the low-pressure side and the pressure control chamber is shut off, the high-pressure fuel or supply source of the fuel source The high-pressure fluid is supplied not only from the first connection flow path but also from the second connection flow path through the connection flow path, so that the pressure in the pressure control chamber can be quickly increased, and further The valve closing characteristics of the needle can be improved.

  According to the ninth aspect of the present invention, the housing has a branch part that branches the high-pressure fuel or the high-pressure fluid into the first connection flow path and the connection flow path, and the branch part is formed in the vicinity of the control valve chamber. It is characterized by that. According to this configuration, the flow passage formed in the fuel injection valve is not provided with a branching portion in the fuel injection valve, and the first connection flow passage and the connection flow passage are directly connected to the fuel source or the supply source. It can be simplified.

  According to a tenth aspect of the present invention, the control valve has a sub chamber piston portion that faces the sub chamber and has a pressure receiving surface facing the end surface of the control valve on the sub chamber side. According to this configuration, when the high-pressure fuel of the fuel source or the high-pressure fluid of the supply source is supplied to the control valve chamber and the sub chamber, the force in the direction opposite to the direction of the force generated when acting on the control valve is Since it occurs in the piston portion, the force required when operating the control valve can be reduced.

  According to the eleventh aspect of the invention, the end portion on the side opposite to the injection hole of the needle has a large-diameter piston portion that slides in an axial direction in an axial hole formed in the housing, and a diameter larger than that of the large-diameter piston portion. A small-diameter piston portion, a connecting portion is formed between the large-diameter piston portion and the small-diameter piston portion, and a first pressure-receiving surface is formed on the end surface of the large-diameter piston portion on the small-diameter piston portion side. It is characterized by being.

  According to this configuration, the end portion on the side opposite to the injection hole of the needle has the large-diameter piston portion and the small-diameter piston portion that slide in the axial direction in the axial hole formed in the housing. Since they are connected by a connecting portion formed between the two piston portions, an outer valve-opening type needle having a portion whose diameter increases toward the counter-injection hole can be easily accommodated in the housing.

  In addition, since the first pressure receiving surface is formed on the end surface of the large diameter piston portion on the small diameter piston portion side, when the pressure in the pressure control chamber acts on the first pressure receiving surface, A force for moving to the side opposite to the injection hole is generated. Since both piston parts are connected by the connection part, the force of the said direction can be provided to a needle, and the seat force of the needle at the time of valve closing can be improved.

(First embodiment)
Hereinafter, a fuel injection valve according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a fuel injection valve 1, for example, a fuel injection valve 1 used in a direct injection gasoline engine (hereinafter abbreviated as an engine). The fuel injection valve 1 is provided corresponding to each cylinder of the engine, and is supplied with fuel from a delivery pipe 11 (corresponding to a fuel source described in claims) via a fuel pipe 14.

  The delivery pipe 11 is provided with the same number of fuel pipes 14 as the number of fuel injection valves 1 provided in the engine, and one fuel injection valve 1 is connected to each fuel pipe 14. Note that the fuel in the fuel tank 13 (corresponding to the low-pressure side described in claims) is pumped by the supply pump 12 and stored at a predetermined fuel pressure in the delivery pipe 11. Control of fuel injection into each cylinder is performed by controlling the fuel injection valve 1 with a control device (not shown). Further, the fuel that has not been injected from the fuel injection valve 1, so-called surplus fuel, is returned to the fuel tank 13 via the return pipe 15.

  As shown in FIG. 1, the fuel injection valve 1 is a rod-like body, and is attached so that a lower portion in the drawing penetrates a combustion chamber wall (not shown) of the engine and protrudes into the combustion chamber. The housing 16 of the fuel injection valve 1 is configured by stacking a plurality of substantially cylindrical parts (nozzle body 2, valve body 5, and nozzle holder 6) in the axial direction. These bodies 2, 5, 6 are fixed to each other by a retaining nut 17.

  The above-mentioned components constituting the housing 16 are formed therein with a flow path and a space through which the fuel flows, and further, in the flow path and the space, there are parts for controlling the flow of the fuel flowing through the flow path. Is provided. By controlling the flow of fuel in the housing 16, the amount and timing of fuel injected from the fuel injection valve 1 can be controlled.

  The nozzle body 2 is a component that is disposed closest to the combustion chamber when the fuel injection valve 1 is mounted on the engine, and is a component that supports the needle 7 so as to be slidable in the axial direction. The nozzle body 2 is composed of a large-diameter side nozzle body 3 and a small-diameter side nozzle body 4, and the small-diameter side nozzle body 4 is composed of an upper nozzle body 41 and a lower nozzle body 43.

  In the large-diameter side nozzle body 3, a vertical hole 31 that supports a part of the needle 7 so as to be slidable in the axial direction is formed so as to penetrate through both end faces of the nozzle body 3. On the outer peripheral side of the vertical hole 31, a part of the high-pressure channel 33 (corresponding to the first connection channel according to the claims) through which the fuel passes and the control pressure channel 35 (second connection flow according to the claims) A part of the nozzle body 3 is formed so as to penetrate both end faces of the large-diameter side nozzle body 3. The high pressure channel 33 and the control pressure channel 35 correspond to the anti-injection hole side connection channel described in the claims.

  An orifice 34 is formed in the middle of the high-pressure channel 33, and an orifice 36 is formed in the middle of the control pressure channel 35. The flow path diameter of the orifice 34 is smaller than the flow path diameter of the orifice 36. For this reason, the amount of fuel passing through the orifice 34 is smaller than the amount of fuel passing through the orifice 36. Further, on the outer peripheral side of the high-pressure flow path 33, a part of the supply flow path 37 (the injection hole side connection flow path described in the claims) through which the fuel from the delivery pipe 11 passes is formed on the large diameter side nozzle body 3. It is formed so as to penetrate both end faces.

  An upper nozzle body 41 of the small diameter side nozzle body 4 is provided below the large diameter side nozzle body 3. The nozzle body 41 is also formed with a vertical hole 42 having a central axis that substantially coincides with the central axis of the vertical hole 31 described above. The vertical hole 42 includes a portion that supports a part of the needle 7 so as to be slidable in the axial direction, and a portion that accommodates a component that biases the needle 7 upward.

  The diameter of the part that accommodates the part that urges the needle 7 upward is larger than the diameter of the part that supports the needle 7. The diameter of the portion that supports the needle 7 is smaller than the diameter of the vertical hole 31 described above. The upper nozzle body 41 is formed with a part of a supply flow path 37 that communicates with a portion that accommodates the aforementioned accessories.

  Between the large-diameter side nozzle body 3 and the upper nozzle body 41, the needle 7 is accommodated in the nozzle body 2, thereby being surrounded by the side surface of the vertical hole 31, the side surface of the needle 7, and the end surface of the upper nozzle body 41. A pressure control chamber 32 is formed. In addition, a low-pressure chamber 38 surrounded by the large-diameter side end face 86, the vertical hole 31, and the lower end face of the valve body 5 is formed on the side opposite to the injection hole of the needle 7. The pressure control chamber 32 is connected to the high-pressure channel 33 and the control pressure channel 35 described above. By controlling the pressure in the pressure control chamber 32, the pressure acting on the needle 7 can be controlled, and the force in the valve closing direction generated on the needle 7 can be controlled.

  A lower nozzle body 43 is provided below the upper nozzle body 41. The nozzle body 43 is also formed with a vertical hole 44 having a central axis substantially coincident with the central axes of the vertical hole 31 and the vertical hole 42 described above. The vertical hole 44 is formed so as to penetrate the tip 45 (corresponding to the tip described in the claims) of the nozzle body 43, and the opening of the vertical hole 44 becomes the injection hole 46. A seat portion 47 on which the needle 7 is seated is formed around the injection hole 46.

  The diameter of the vertical hole 44 decreases as it approaches the injection hole 46. The diameter on the upper nozzle body 41 side is a diameter that can accommodate the above-described components, and the lower diameter is a diameter that locks a part of the above-described components.

  When the upper nozzle body 41 and the lower nozzle body 43 are overlapped in the axial direction, a space that can accommodate the above-described components is formed. This space becomes the fuel reservoir chamber 48. Fuel that has passed through the supply passage 37 is stored in the fuel reservoir chamber 48, and the fuel reservoir chamber 48 communicates with the injection hole 46. The fuel reservoir chamber 48 accommodates an upper spring receiving portion 481, a lower spring receiving portion 482, and a coil spring 483, which are components for urging the needle 7 upward.

  The coil spring 483 is disposed between the upper spring receiving portion 481 and the lower spring receiving portion 482 in a compressed state. The upper spring receiving portion 481 is locked to the step portion of the needle 7, and the lower spring receiving portion 482 is locked to the step portion formed in the lower nozzle body 43. For this reason, the urging force of the coil spring 483 acts upward on the needle 7. A gap of a distance L is formed between the spring receiving portions 481 and 482 in a state where the needle 7 is seated on the seat portion 47. The structure of the needle 7 will be described later in detail.

  Above the large-diameter side nozzle body 3, a valve body 5 that houses a control valve 521 that controls the fuel pressure in the pressure control chamber 32 is provided. The valve body 5 is formed with a control valve chamber 52 that accommodates the control valve 521 and a sub chamber 53 that is always in communication with the control valve chamber 52 in a substantially central portion. A vertical hole 51 is formed below the sub chamber 53, and a spring chamber 57 is formed below the vertical hole 51. Below the spring chamber 57, a connection channel 59 that connects the spring chamber 57 and the low-pressure chamber 38 formed at the end of the needle 7 is formed.

  These chambers 52, 53, 57, 38 and the hole 51 and the flow path 59 are arranged from the counter-injection hole side to the control valve chamber 52, the sub chamber 53, the vertical hole 51, the spring chamber 57, the connection flow path 59, and the low pressure chamber 38. Are arranged side by side in the axial direction. Further, a return flow path 58 communicating with the fuel tank 13 is connected to the spring chamber 57, and when the injection hole 46 is closed, the pressure in the spring chamber 57 and the low pressure chamber 38 is controlled by the control valve chamber 52. The sub chamber 53, the pressure control chamber 32, and the fuel reservoir chamber 48 are lower.

  A part of the high-pressure channel 33 and a part of the control pressure channel 35 are formed on the outer peripheral side of the chambers 52, 53, 57, 38 and the hole 51 and the channel 59. A part of the supply channel 37 is formed on the outer peripheral side of the high-pressure channel 33. Furthermore, a branch portion 55 is formed on the upper end surface of the valve body 5 to branch the fuel from the delivery pipe 11 into the high-pressure channel 33 and the supply channel 37. Further, a connecting channel 56 (corresponding to the connecting channel described in the claims) connected to the sub chamber 53 is formed in the branch portion 55.

  By providing the branch portion 55 in the vicinity of the control valve chamber 52 in this way, ports for the high pressure flow path 33 and the connection flow path 56 for supplying fuel from the delivery pipe 11 are individually formed in the fuel injection valve 1. This eliminates the necessity for reducing the flow path length of the connection flow path 56 as much as possible, thereby simplifying the flow path formed in the fuel injection valve 1. The control valve 521 will be described in detail later.

  Above the valve body 5, a piezo actuator 611 that is an actuator that drives the control valve 521 and a nozzle holder 6 that houses a transmission piston 612 that transmits the displacement of the actuator 611 to the control valve 521 are provided. The nozzle holder 6 comprises two substantially cylindrical parts, and has a receiving hole 61 whose lower part communicates with the control valve chamber 52 and whose upper part communicates with the discharge port 63. The accommodation hole 61 accommodates a piezo actuator 611 and a transmission piston 612. A part of the supply passage 37 having a supply port 62 to which the fuel pipe 14 is connected is formed on the outer peripheral side of the accommodation hole 61. The supply channel 37 is formed so as to pass through the branch portion 55.

  Next, the control valve 521 will be described. The control valve 521 is a valve that functions as a so-called two-position three-way valve, and a flow path for supplying the fuel in the supply flow path 37 to the pressure control chamber 32 and a flow for discharging the fuel in the pressure control chamber 32 to the return pipe 15. Switching between roads.

  Specifically, when the control valve 521 is controlled to one position, the fuel flows in the order of the supply flow path 37, the branch portion 55, the connection flow path 56, the sub chamber 53, the control valve chamber 52, and the control pressure flow path 35. When the first path is formed and controlled to the other position, the second path through which the fuel flows is formed in the order of the pressure control chamber 32, the control pressure channel 35, the control valve chamber 52, the accommodation hole 61, and the discharge port 63. Is done.

  An upper seat portion 541 on which the control valve 521 is seated is formed on the lower end surface of the nozzle holder 6. When the control valve 521 moves upward and sits on the upper seat portion 541, the flow path between the control valve chamber 52 and the discharge port 63 is cut off, and the first path described above is formed.

  A lower seat portion 542 on which the control valve 521 is seated is formed between the control valve chamber 52 and the sub chamber 53. When the control valve 521 moves downward and sits on the lower seat portion 542, the flow path between the sub chamber 53 and the control valve chamber 52 is cut off, and the above-described second path is formed.

  The control valve 521 has a sub chamber piston portion 522 below. A coil spring 524 that biases the control valve 521 and the sub chamber piston portion 522 upward is provided below the sub chamber piston portion 522. The sub chamber piston 522 is supported in the longitudinal hole 51 so as to be slidable in the axial direction. The upper end surface 523 of the sub chamber piston part 522 faces the sub chamber 53, and the lower end surface is arranged as desired in the spring chamber 57.

  It is possible to control whether the control valve 521 is seated on the upper seat portion 541 or the lower seat portion 542 by releasing the charge of the piezo actuator 611 or injecting the charge.

  When the electric charge of the piezo actuator 611 is released, the actuator 611 contracts, so that the transmission piston 612 moves upward. Since the sub chamber piston portion 522 is biased upward by the coil spring 524, the control valve 521 moves upward and is seated on the upper seat portion 541.

  When electric charge is injected into the piezo actuator 611, the actuator 611 extends, so that the transmission piston 612 moves downward. The control valve 521 is pushed downward by the transmission piston 612 and is seated on the lower seat portion 542.

  Since the control chamber 521 is provided with the sub chamber piston portion 522, when fuel is supplied from the delivery pipe 11 through the connection channel 56, the fuel pressure is applied to the upper end surface 523 of the sub chamber piston portion 522. Therefore, when the control valve 521 is moved downward, the burden on the piezo actuator 611 can be reduced.

  Next, the needle 7 will be described in detail. As shown in FIG. 1, the needle 7 has a valve body portion 71 that opens and closes the injection hole 46 at one tip portion. The valve body 71 is a so-called outer valve. When the needle 7 moves downward, the valve body 71 moves away from the seat 47 of the injection hole 46, and when the needle 7 moves upward, the valve body 71 is moved to the seat 47. Sit down.

  The needle 7 has a large-diameter piston portion 8 and a small-diameter piston portion 9 having different outer diameters at the end on the side opposite to the injection hole. The large-diameter piston portion 8 is provided on the side opposite to the injection hole from the small-diameter piston portion 9. The piston portions 8 and 9 are supported in the longitudinal holes 31 and 42 so as to be slidable in the axial direction, respectively.

  The large-diameter piston portion 8 and the small-diameter piston portion 9 are composed of separate parts. The large-diameter piston portion 8 is formed with a large-diameter side locking portion 82, and the small-diameter piston portion 9 has a small-diameter side. A locking portion 91 is formed. By locking the large diameter side locking portion 82 and the small diameter side locking portion 91, the large diameter piston portion 8 and the small diameter piston portion 9 are connected to each other. In addition, the large diameter side latching | locking part 82 and the small diameter side latching | locking part 91 are equivalent to the connection part as described in a claim. By connecting the large-diameter piston portion 8 and the small-diameter piston portion 9 by the locking portions 82 and 91, the needle 7 becomes an integral body and can move together in the axial direction.

  Next, the large diameter piston part 8 and the small diameter piston part 9 will be described in detail. The large-diameter piston portion 8 includes two parts, a substantially cylindrical large-diameter side sliding portion 81 and a substantially cylindrical large-diameter side locking portion 82 having an outer diameter larger than that of the large-diameter sliding portion 81. Have. At least the large-diameter side sliding portion 81 is supported in the longitudinal hole 31 formed in the large-diameter side nozzle body 3 so as to be slidable in the axial direction. Thereby, the vertical hole 31 is divided into the pressure control chamber 32 and the low pressure chamber 38.

  As shown in FIG. 3, the large-diameter side locking portion 82 has a groove 83 that opens downward. The groove 83 is formed so as to open also on the radial side surface of the large-diameter side locking portion 82. On the inner wall of the groove 83, a large-diameter side locking surface 84 that contacts the small-diameter side locking portion 91 is formed. The large-diameter side locking surface 84 is formed on the inner wall of the groove portion 83 so as to intersect the axial direction of the needle 7 and so that the surface 84 faces upward. When the groove part 83 is viewed from the side, the distance between the inner walls above the opening part is larger than the distance between the inner walls of the opening part of the groove part 83. In the present embodiment, the groove 83 includes two large diameter side locking surfaces 84.

  FIG. 6 is a plan view of the large-diameter side locking portion 82 of the large-diameter piston portion 8. These two large-diameter side locking surfaces 84 are formed so that the distance L1 between the large-diameter side locking surfaces 84 is substantially the same, as shown in FIG.

  The small-diameter piston portion 9 has two parts, a substantially cylindrical small-diameter side sliding portion 95 and a substantially cylindrical small-diameter side locking portion 91 having an outer diameter equal to or smaller than the outer diameter of the small-diameter side sliding portion 95. is doing. The small diameter side sliding portion 95 is supported by the vertical hole 42 formed in the small diameter side nozzle body 4 so as to be slidable in the axial direction.

  Here, the gap between the large-diameter side sliding portion 81 and the vertical hole 31 and the gap between the small-diameter side sliding portion 95 and the vertical hole 42 are set to such an extent that the liquid tightness of the pressure control chamber 32 can be secured. Yes. For example, it is set to a very small value such as 1 to 5 μm.

  The small diameter side locking portion 91 includes a head portion 92 and a rod portion 93 that connects the head portion 92 and the small diameter side sliding portion 95. As shown in FIG. 3, the head portion 92 has an outer diameter larger than that of the rod portion 93, and a small-diameter side locking surface 94 facing the above-described large-diameter side locking surface 84 is formed on the lower surface of the head portion 92. Is formed. The large-diameter side locking portion 82 and the small-diameter side locking portion 91 correspond to the connecting portion described in the claims.

  When connecting the large-diameter piston portion 8 and the small-diameter piston portion 9, as shown in FIG. 4, the small-diameter side end surface 99 of the head portion 92 faces the bottom portion 87 of the groove portion 83 from the side of the groove portion 83. The head portion 92 and the rod portion 93 are inserted into the small diameter side engaging surface 84 and the small diameter side engaging surface 94 is brought into contact with the large diameter side engaging surface 84. When the small-diameter piston portion 9 is connected to the large-diameter piston portion 8, the small-diameter side locking portion 94 is covered with the groove portion 83, so that the axial length of the needle 7, that is, the overall length of the fuel injection valve 1 becomes long. Can be suppressed.

  Thus, since both piston parts 8 and 9 are connected, when the force of the direction away from each other generate | occur | produces in both piston parts 8 and 9, large diameter side locking surface 84 and small diameter side locking surface 94 Can abut both piston portions 8 and 9 together in either the upward or downward direction. Contact between the large-diameter side locking surface 84 and the small-diameter side locking surface 94 is surface contact. Thereby, the load concerning the large diameter side latching surface 84 and the small diameter side latching surface 94 can be disperse | distributed.

  As shown in FIG. 1 and FIG. 3, the needle 7 in a state where the large-diameter piston portion 8 and the small-diameter piston portion 9 are connected includes an end portion below the large-diameter piston portion 8 and an end portion of the small-diameter piston portion 9. Is disposed in the housing 16 so as to face the pressure control chamber 32. Therefore, when the fuel of the delivery pipe 11 is supplied to the pressure control chamber 32 via the high pressure flow path 33, the large diameter side pressure receiving surface 85, which is the lower end surface of the large diameter side locking portion 82, and the small diameter side slide. Fuel pressure acts on a small diameter side pressure receiving surface 96 which is a surface formed between the moving portion 95 and the rod portion 93. The large-diameter side pressure receiving surface 85 is disposed in the pressure control chamber 32 so as to face the injection hole 46. The large diameter side pressure receiving surface 85 corresponds to the first pressure receiving surface recited in the claims.

  When fuel having a predetermined fuel pressure is supplied to the pressure control chamber 32, the same pressure acts on the large diameter side pressure receiving surface 85 and the small diameter side pressure receiving surface 96. When fuel pressure acts on the large diameter side pressure receiving surface 85, a force that moves the needle 7 upward is generated in the large diameter piston portion 8. Further, when fuel pressure acts on the small diameter side pressure receiving surface 96, a force that moves the needle 7 downward is generated in the small diameter piston portion 9. Since the large diameter side pressure receiving surface 85 has a larger projected area in the axial direction than the small diameter side pressure receiving surface 96, a force that moves upward is generated in the needle 7.

  As described above, since the pressure in the low pressure chamber 38 is connected to the fuel tank 13 on the low pressure side, the pressure value in the pressure control chamber 32 becomes equal to or higher than the pressure value in the low pressure chamber 38 and the needle 7 moves upward. The force to be increased can be increased.

  If it demonstrates in detail, the force which moved this piston part 8 to the large diameter piston part 8 will generate | occur | produce in the large diameter piston part 8 from the pressure which acted on the large diameter side pressure-receiving surface 85. FIG. The pressure acting on the small diameter side pressure receiving surface 96 generates a force in the small diameter piston portion 9 that moves the small diameter piston portion 9 downward. Since the upward force generated in the large-diameter piston portion 8 is superior to the downward force generated in the small-diameter piston portion 9, the large-diameter piston portion 8 moves upward so as to pull the small-diameter piston portion 9 upward. .

  Since the pressure in the pressure control chamber 32 can be adjusted by the control valve 521, the upward force generated in the needle 7 can be adjusted. Part of the fuel supplied to the pressure control chamber 32 passes between the side surfaces of the large-diameter side locking portion 82 and the large-diameter side sliding portion 81 and the inner wall of the vertical hole 31, the connection flow path 59, and the spring chamber. 57 and the return passage 58 to return to the fuel tank 13.

  Next, the relationship between the fuel pressure acting on the needle 7 and the force generated on the needle 7 will be described. The axial position of the needle 7 is determined by the balance between the force that moves the needle 7 downward and the force that moves the needle 7 upward.

  The force for moving the needle 7 downward is such that the fuel pressure supplied to the fuel reservoir chamber 48 via the supply flow path 37 acts on the pressure receiving surface 72 of the valve body 71 (second pressure receiving surface described in claims). And a force generated when the fuel pressure in the low-pressure chamber 38 acts on the large-diameter side end face 86.

  The force for moving the needle 7 upward is such that the biasing force of the coil spring 483 accommodated in the fuel reservoir chamber 48 and the fuel pressure supplied to the pressure control chamber 32 are smaller than the aforementioned large diameter side pressure receiving surface 85. This is the total force with the force generated by acting on the area obtained by subtracting the pressure receiving surface 96.

  As shown in FIG. 1, when the pressure in the pressure control chamber 32 is the same as that of the delivery pipe 11, the force for moving the needle 7 upward is superior to the force for moving the needle 7 downward. Therefore, the needle 7 tries to move upward.

  The balance of forces described above can be changed by adjusting the pressure in the pressure control chamber 32. When the pressure in the pressure control chamber 32 is decreased, the force to move upward is weakened, so that the force to move downward is superior to the force to move upward, and the needle 7 moves downward. From this state, when the pressure in the pressure control chamber 32 is increased again (the pressure is the same as that of the delivery pipe 11), the force to move upward is superior to the force to move downward, and the needle 7 moves upward. To do.

  In this embodiment, when the large-diameter side pressure receiving surface 85 of the large-diameter piston portion 8 of the needle 7 faces the pressure control chamber 32 and a pressure in the pressure control chamber 32 acts, a force that moves the needle 7 upward is generated. Therefore, the seat force when the valve body 71 is seated on the seat 47 is improved without increasing the physique of the coil spring 483 compared to the conventional open valve type. It is done.

  Further, by adjusting the pressure in the pressure control chamber 32, the force that moves the needle 7 upward can be adjusted, and the movement of the needle 7 can be controlled. That is, the movement of the needle 7 can be controlled without preparing a separate drive device for moving the needle 7.

  That is, the large-diameter side pressure receiving surface 85 faces the pressure control chamber 32 and the pressure control chamber 32 can be adjusted to improve the seat force of the needle 7 when the injection hole 46 is closed, and the needle 7 can be combined with the function of controlling the movement of 7.

  Further, since the outer diameter of the large-diameter side locking portion 82 is larger than the outer diameter of the large-diameter side sliding portion 81, the area of the large-diameter side locking surface 84 that comes into contact with the small-diameter-side locking surface 94 is increased. be able to. According to this, the load concerning each locking surface 84 and 94 at the time of the needle 7 moving upward can be disperse | distributed.

  And as shown in FIG. 5, the cross section of the rod part 93 becomes a shape which cut off two cylindrical side surfaces in the axial direction. By forming the rod portion 93 in this way, the cross-sectional area of the rod portion 93 can be made as large as possible while ensuring the area of the small-diameter side locking surface 94 formed on the head portion 92. Strength reduction can be suppressed.

  Further, as shown in FIG. 3, the shape of the connecting portion 97 between the head portion 92 and the rod portion 93 and the connecting portion 98 between the rod portion 93 and the small diameter side sliding portion 95 are curved or chamfered. As a result, the stress concentration at each of the connection portions 97 and 98 that occurs when the small-diameter piston portion 9 moves upward as pulled by the large-diameter piston portion 8 can be reduced.

  Further, as shown in FIG. 6, the large-diameter side locking surface 84 of the large-diameter piston portion 8 is formed so that the distance L1 between the large-diameter side locking surfaces 84 is substantially the same. When the small diameter side locking surface 94 is brought into contact with the locking surface 84 and the needle 7 moves upward or downward, the side surfaces of the large diameter side sliding portion 81 and the small diameter side sliding portion 95 are in the vertical holes 31 and 42. It can suppress that it touches and can connect both piston parts 8 and 9 stably.

  The large-diameter side locking surfaces 84 formed in the groove 83 are not limited to two. As shown in FIG. 7, the large-diameter side locking surfaces 84 may be three. Even when there are three or more large-diameter side locking surfaces 84, it is preferable that the distance L2 between the large-diameter side locking surfaces 84 is the same as in the large-diameter side locking surface 84 shown in FIG.

  Next, the operation of this embodiment will be described with reference to FIGS. FIG. 1 shows a state where fuel injection is stopped, and FIG. 2 shows a state where fuel injection is being performed.

  In the state of FIG. 1, the piezo actuator 611 is in a state in which charges are released. In this state, the actuator 611 contracts and the transmission piston 612 moves upward. Since the transmission piston 612 is moved upward, the control valve 521 is moved upward by the urging force of the coil spring 524, and the control valve 521 is seated on the upper seat portion 541.

  In this state, when fuel having a predetermined fuel pressure is supplied from the delivery pipe 11 to the supply channel 37 from the supply port 62, the fuel is supplied to the fuel reservoir chamber 48 via the supply channel 37. . The fuel in the supply flow path 37 is supplied to the pressure control chamber 32 from two paths of the high pressure flow path 33, the connection flow path 56, the sub chamber 53, the control valve chamber 52, and the control pressure flow path 35.

  At this time, as described above, the needle 7 has a downward force generated when the fuel pressure of the fuel reservoir chamber 48 is applied to the pressure receiving surface 72, and the pressure control chamber is connected to the large diameter side pressure receiving surface 85 and the small diameter side pressure receiving surface 94. An upward force generated when 32 fuel pressures are applied and an upward force due to the biasing force of the coil spring 483 are generated. In this state, since the upper force is superior to the lower force, the needle 7 tries to move upward. For this reason, the state in which the valve body portion 71 is seated on the seat portion 47 is maintained.

  Subsequently, when electric charge is injected into the piezo actuator 611, the actuator 611 extends and the transmission piston 612 moves downward. When the transmission piston 612 moves downward, the control valve 521 also moves downward, and the control valve 521 is seated on the lower seat portion 542.

  When the control valve 521 is seated on the lower seat portion 542, the communication between the control valve chamber 52 and the sub chamber 53 is cut off, so that the fuel flow path changes. That is, a path of the pressure control chamber 32, the control pressure channel 35, the control valve chamber 52, the accommodation hole 61, and the discharge port 63 is formed, and the fuel in the pressure control chamber 32 is discharged from the fuel injection valve 1. Fuel is supplied to the pressure control chamber 32 through the high-pressure flow path 33 in the same manner as when the injection is stopped. However, since the diameter of the orifice 34 is smaller than the diameter of the orifice 36, the pressure in the pressure control chamber 32 decreases. To do.

  Then, the balance of the above-described forces acting on the needle 7 changes. That is, the downward force generated in the needle 7 is superior to the upward force, and the needle 7 moves downward. Therefore, the valve body portion 71 is separated from the seat portion 47, and the fuel in the fuel reservoir chamber 48 is injected from the injection hole 46.

  When the fuel is injected for a predetermined time and the electric charge of the piezo actuator 611 is released again, the fuel injection valve 1 returns to the state shown in FIG. 1 and the fuel injection stops. In this embodiment, since there are two fuel supply paths to the pressure control chamber 32 (a path supplied via the high-pressure channel 33 and a path supplied via the control pressure channel 35), the pressure control chamber The pressure recovery within 32 is relatively fast. For this reason, the speed at which the needle 7 is moved upward can be increased, and the valve closing characteristics of the fuel injection valve 1 can be improved.

  Next, the manufacturing procedure of the fuel injection valve 1 will be described with reference to FIG. Since the needle 7 used in the fuel injection valve 1 of this embodiment is of a so-called outer valve type, first, the needle 7 in a state where the large-diameter piston portion 8 is separated is used as the injection hole of the lower nozzle body 43. The small diameter piston portion 9 is inserted from 46.

  Thereafter, the lower spring receiving portion 482, the coil spring 483, and the upper spring receiving portion 481 are inserted into the needle 7 in this order from above. Thereafter, the upper nozzle body 41 is placed on the lower nozzle body 43 from above. At this time, as shown in FIG. 8, a small-diameter side locking portion 91 protrudes from the upper end surface of the upper nozzle body 41.

  Then, the small diameter side locking part 91 and the large diameter side locking part 82 are connected as shown in FIG. Then, the large-diameter side nozzle body 3 is covered from above, and the large-diameter side sliding portion 81 is inserted into the vertical hole 31.

  Thereafter, although not shown, the valve body 5 with the control valve 521 and the like and the nozzle holder 6 with the piezo actuator 611 and the like are sequentially covered from above the large-diameter side nozzle body 3. Finally, the retaining diameter 17 integrates the small diameter side nozzle body 4, the large diameter side nozzle body 3, the valve body 5, and the nozzle holder 6.

  As described above, even if the needle 7 is an outer valve-opening type needle 7 having a portion (large diameter piston portion 8) in which the outer diameter of the needle 7 increases as it goes upward, the needle 7 is a large diameter piston. Since the portion 8 and the small-diameter piston portion 9 can be separated from each other, the nozzle body 2 (the large-diameter side nozzle body 3 and the small-diameter side nozzle body 4) can be easily accommodated only by following the procedure described above. be able to.

  In this embodiment, the nozzle body 2 is composed of a large-diameter side nozzle body 3 and a small-diameter side nozzle body 4, and each nozzle body 3, 4 has a vertical hole 31 that supports the needle 7 slidably in the axial direction, 42 is formed. Therefore, depending on the accuracy of processing, the axis of each of the vertical holes 31 and 42 may be displaced.

  In this embodiment, the inner wall of the head portion 92 and the rod portion 93 of the small diameter side locking portion 91 and the groove portion 83 of the large diameter side locking portion 82 are connected when the small diameter piston portion 9 is connected to the large diameter piston portion 8. The gap fitting dimensional tolerance is such that a gap is formed between the side surfaces of the head portion 92 and the rod portion 93 and the inner wall of the groove portion 83. For this reason, the shift | offset | difference of the axis of each vertical hole 31 and 42 can be absorbed.

  In the first embodiment, the pressure control chamber 32 is supplied with the same fluid as the fluid supplied to the fuel reservoir chamber 48, that is, the fuel in the delivery pipe 11. However, as shown in FIG. The fluid supplied to the chamber 32 and the fluid supplied to the fuel reservoir chamber 48 may be different. For example, as shown in FIG. 9, other high-pressure fluid (hydraulic oil) that is not fuel is supplied to the pressure control chamber 32, and fuel in the delivery pipe 11 is supplied to the fuel reservoir 48.

  Specifically, in addition to the delivery pipe 11, a hydraulic oil pipe 11a as a supply source described in the claims is provided, and the hydraulic oil is supplied from the pipe 11a to the pressure control chamber 32 and the sub chamber 53 via the hydraulic oil pipe 14a. Supply. In the hydraulic oil pipe 11a, the hydraulic oil in the hydraulic oil tank 13a is pumped by the hydraulic oil supply pump 12a and stored at a predetermined pressure.

  In this case, unlike the first embodiment, the supply flow path 37a for supplying fuel to the fuel reservoir chamber 48, the pressure control chamber 32, and the sub chamber 53 hydraulic oil flow path 37b need to be independent flow paths. is there. The hydraulic oil discharged from the pressure control chamber 32 and the sub chamber 53 is returned to the hydraulic oil tank 13a via the hydraulic oil return pipe 15a.

  Since the components other than those described above of the fuel injection valve 1a in the other embodiments have the same configuration, the description of each component and the operation description of the fuel injection valve 1a are omitted.

(Second Embodiment)
Next, a fuel injection valve 1b according to a second embodiment of the present invention will be described with reference to FIG. FIG. 10 is a diagram corresponding to FIG. 1 of the first embodiment, and shows the time when fuel injection is stopped. Here, only differences from the above-described first embodiment will be described.

  The difference from the first embodiment is that in the first embodiment, the high-pressure flow path 33 is formed as shown in FIG. 1, whereas in the second embodiment, the above-described high-pressure flow is shown in FIG. This is a point where the flow path 33 is not formed. In FIG. 10, since the high-pressure channel 33 is not formed, the supply / discharge of fuel to / from the pressure control chamber 32 is performed as follows.

  In the state where the electric charge of the piezo actuator 611 is released, the actuator 611 is contracted, so that the transmission piston 612 is moved upward. At this time, the control valve 521 moves upward by the biasing force of the coil spring 524, and the control valve 521 is seated on the upper seat portion 541.

  In this state, when fuel having a predetermined fuel pressure is supplied from the delivery pipe 11 to the supply channel 37 from the supply port 62, the fuel is supplied to the fuel reservoir chamber 48 via the supply channel 37. . The fuel in the supply flow path 37 is supplied to the pressure control chamber 32 from a single path including the connection flow path 56, the sub chamber 53, the control valve chamber 52, and the control pressure flow path 35.

  At this time, as described in the first embodiment, the needle 7 tends to move upward, so that the state in which the valve body 71 is seated on the seat portion 47 is maintained, and fuel injection is stopped.

  Subsequently, when electric charge is injected into the piezo actuator 611, the actuator 611 expands, so that the transmission piston 612 moves downward. When the transmission piston 612 moves downward, the control valve 521 also moves downward, and the control valve 521 is seated on the lower seat portion 542.

  When the control valve 521 is seated on the lower seat portion 542, the communication between the control valve chamber 52 and the sub chamber 53 is cut off, so that the fuel flow path changes. A path of the pressure control chamber 32, the control pressure channel 35, the control valve chamber 52, the accommodation hole 61, and the discharge port 63 is formed, and the fuel in the pressure control chamber 32 is discharged from the fuel injection valve 1, and the pressure in the pressure control chamber 32 is Will decline.

  Then, as described in the first embodiment, the needle 7 tends to move downward, so that the valve body 71 is separated from the seat portion 47 and the fuel in the fuel reservoir chamber 48 is injected from the injection hole 46. Is done. When the fuel is injected for a predetermined time and the electric charge of the piezo actuator 611 is released again, the needle 7 moves upward, the valve body 71 is seated on the seat portion 47, and the fuel injection stops.

  In the present embodiment, unlike the first embodiment, the high-pressure channel 33 is not provided. Therefore, when the fuel in the pressure control chamber 32 is discharged, no new high-pressure fuel is supplied to the pressure control chamber 32, so that loss of fuel pressure in the delivery pipe 11 can be suppressed.

It is sectional drawing at the time of the injection stop of the fuel injection valve in 1st Embodiment of this invention. It is sectional drawing at the time of injection of the fuel injection valve in 1st Embodiment of this invention. It is principal part sectional drawing of the needle of FIG. It is a disassembled perspective view of the needle of FIG. It is sectional drawing of the rod part of the needle of FIG. It is a top view of the large diameter side latching | locking part of the large diameter piston part of FIG. It is a top view of the large diameter side latching | locking part in the modification of the large diameter side latching | locking part of FIG. FIG. 2 is an exploded cross-sectional view of a nozzle body portion of FIG. It is sectional drawing of the fuel injection valve in other embodiment of 1st Embodiment of this invention. It is sectional drawing of the fuel injection valve in 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Fuel injection valve, 11 Delivery pipe (fuel source), 12 Supply pump, 13 Fuel tank (low pressure side), 14 Fuel piping, 15 Return piping, 16 Housing, 17 Retaining nut, 2 Nozzle body, 31 Vertical hole (shaft) Direction hole), 32 pressure control chamber, 33 high pressure flow path (anti-injection hole side connection flow path, first connection flow path), 35 control pressure flow path (anti-injection hole side connection flow path, second connection flow path), 37 Supply flow path (injection hole side connection flow path), 38 low pressure chamber, 42 vertical hole (axial hole), 43 lower nozzle body, 44 vertical hole (axial hole), 45 tip, 46 injection hole, 48 fuel pool Chamber, 5 valve body, 51 vertical hole, 52 control valve chamber, 53 sub chamber, 55 branching section, 56 connecting flow path (connecting flow path), 57 spring chamber, 521 control valve, 522 sub chamber piston section, 523 upper end surface ( Pressure-receiving surface facing the sub-chamber end surface of the control valve), 6 nozzle holder, 61 receiving hole, 611 piezo actuator, 612 transmission piston, 7 needle, 71 valve body, 72 pressure-receiving surface (second pressure-receiving surface), 8 Large-diameter piston portion, 81 Large-diameter side sliding portion, 82 Large-diameter side locking portion (connecting portion), 83 Groove portion, 84 Large-diameter side locking surface, 85 Large-diameter side pressure-receiving surface (first pressure-receiving surface) , 9 Small diameter piston part, 91 Small diameter side locking part (connecting part), 92 Head part, 93 Rod part, 94 Small diameter side locking surface, 95 Small diameter side sliding part, 96 Small diameter side pressure receiving surface

Claims (11)

In a fuel injection valve that injects or stops high pressure fuel from a fuel source,
A housing in which an injection hole is formed at the tip,
A fuel reservoir chamber that communicates with the injection hole and into which the high-pressure fuel from the fuel source is introduced;
A pressure control chamber that is provided on the side opposite to the injection hole from the fuel reservoir chamber and is introduced with a high-pressure fluid different from the high-pressure fuel or the high-pressure fuel;
A pressure received in the housing and having a pressure receiving surface on which the pressure of the high pressure fuel in the fuel reservoir chamber and the pressure of the high pressure fuel or the high pressure fluid in the pressure control chamber act, and acting on the pressure receiving surface A fuel injection valve having a needle that opens the injection hole when moved to the injection hole side and closes the injection hole when moved to the anti-injection hole side,
Among the pressure receiving surfaces of the needle, the pressure receiving surface facing the pressure control chamber is a force that moves the needle to the side opposite to the injection hole when the pressure of the high pressure fuel or the high pressure fluid in the pressure control chamber is applied. A fuel injection valve having a first pressure receiving surface for generating The housing is formed with an axial hole for accommodating the needle,
The needle is accommodated so as to divide the axial hole from the injection hole in the order of the fuel reservoir chamber, the pressure control chamber, and the low pressure chamber,
2. The fuel injection valve according to claim 1, wherein the first pressure receiving surface is disposed so as to face the pressure control chamber and to face the injection hole.   The fuel injection valve according to claim 2, wherein the pressure value in the pressure control chamber is equal to or greater than the pressure value in the low pressure chamber.   The fuel injection valve according to claim 2 or 3, wherein the low-pressure chamber is connected to a low-pressure side. Of the pressure receiving surface of the needle, the pressure receiving surface facing the fuel reservoir chamber generates a force for moving the needle toward the injection hole when the pressure of the high pressure fuel in the fuel reservoir chamber is applied. Having a pressure-receiving surface,
The housing supplies the high-pressure fuel or the high-pressure fluid from the fuel source to the pressure control chamber, and discharges the high-pressure fuel from the pressure control chamber to the low-pressure side. An injection hole side connection flow path for supplying to the reservoir chamber, and a control valve chamber formed in the middle of the anti-injection hole side connection flow path,
In the control valve chamber, the anti-injection hole side connection flow path is opened and closed to supply the high-pressure fuel or the high-pressure fluid to the pressure control chamber, and the high-pressure fuel or the high-pressure from the pressure control chamber. The fuel injection valve according to any one of claims 1 to 4, further comprising a control valve that controls discharge of fluid and controls a pressure of the pressure control chamber.   The anti-injection hole side connection flow path includes a first connection flow path that always connects the fuel source and the pressure control chamber, or a supply source of the high pressure fluid and the pressure control chamber, and the low pressure side and the pressure control. The fuel injection according to claim 5, further comprising: a second connection flow path connected to a chamber and controlled by the control valve to communicate or block the low pressure side and the pressure control chamber. valve.   The second connection flow path is more than the amount of the high-pressure fuel or the high-pressure fluid discharged from the pressure control chamber to the low-pressure side via the second connection flow path when the control valve is opened. The fuel injection valve according to claim 6, wherein the amount of the high-pressure fuel or the high-pressure fluid supplied to the pressure control chamber via the first connection flow path is smaller. . The housing has a sub-chamber connected to the control valve chamber, and a connecting flow path always connected to the fuel source or the supply source in the sub-chamber,
8. The connection flow path and the second connection flow path are connected when the control valve blocks communication between the low pressure side and the pressure control chamber. The fuel injection valve described in 1. The housing has a branching portion that branches the high-pressure fuel or the high-pressure fluid into the first connection channel and the connection channel,
The fuel injection valve according to claim 8, wherein the branch portion is formed in the vicinity of the control valve chamber.   10. The fuel according to claim 8, wherein the control valve has a sub chamber piston portion facing the sub chamber and having a pressure receiving surface facing an end surface of the control valve on the sub chamber side. Injection valve. The end of the needle on the side opposite to the injection hole has a large-diameter piston portion that slides in the axial direction in the axial hole formed in the housing and a small-diameter piston portion that has a smaller diameter than the large-diameter piston portion. And
A connecting portion is formed between the large diameter piston portion and the small diameter piston portion,
The fuel injection valve according to any one of claims 1 to 10, wherein the first pressure receiving surface is formed on an end surface of the large-diameter piston portion on the small-diameter piston portion side.

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