JP2010223198A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the reliability of a piezo actuator while improving energy efficiency in a direct-acting fuel injection valve having a variable displacement magnification which is opened when the piezo actuator extends (i.e., when charged). <P>SOLUTION: Members to be driven 20-24 are driven in the valve closing direction of a nozzle needle 13 when a piezo actuator 14 extends. The displacements of the members to be driven 20-24 are transmitted to the nozzle needle 13 after the directions of the displacements are inverted by two types of levers 25, 26. The two types of levers 25, 26 have different lever ratios. While the piezo actuator 14 extends, at the beginning of the extension of the piezo actuator 14, the nozzle needle 13 is driven in the valve opening direction mainly by the lever having a smaller lever ratio, and at the last of the extension of the piezo actuator 14, the nozzle needle 13 is driven in the valve opening direction by the lever having a larger lever ratio. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel injection valve for injecting fuel into an internal combustion engine.

  A fuel injection valve that drives a nozzle needle by transmitting a driving force of a piezo actuator to the nozzle needle via a hydraulic or mechanical mechanism is called a direct acting type. In a direct acting fuel injection valve, a large force is required to drive the nozzle needle at the start of valve opening. In addition, when the nozzle is lifted after opening the valve, the pressure that urges the nozzle needle toward the valve closing balances with the pressure that urges the nozzle needle toward the valve opening. It is necessary to secure a large amount of displacement.

  The fuel injection valve disclosed in Patent Document 1 is a direct-acting fuel injection valve, which charges a charge and extends a piezo actuator to drive a nozzle needle in a valve closing direction, thereby discharging the charge and discharging the piezo. The nozzle needle is driven in the valve opening direction by contracting the actuator.

  In addition, the fuel injection valve disclosed in Patent Document 1 has a displacement expansion ratio after opening the valve rather than a displacement expansion ratio at the start of the valve opening (where the displacement expansion ratio is the displacement amount of the nozzle needle / the expansion / contraction amount of the piezo actuator). Since the rate is increased, a large driving force can be obtained at the start of the valve opening, and a large displacement amount of the nozzle needle can be ensured at the time of the nozzle lift after the valve opening. As a result, the charging energy to the piezo actuator can be reduced as compared with the fuel injection valve having a constant displacement expansion rate. That is, energy efficiency can be improved.

US Pat. No. 6,776,354

  However, in the case of the method of charging and closing the valve as in the fuel injection valve disclosed in Patent Document 1, during the operation of the internal combustion engine, the time during which the piezoelectric actuator is at a high voltage is Since it is longer than the time during which the voltage is low, the piezo actuator is liable to cause dielectric breakdown, which is undesirable in terms of reliability (durability, etc.) of the piezo actuator.

  The present invention has been made in view of the above points, and it is an object of the present invention to improve the reliability of a piezo actuator in a direct-acting fuel injection valve that improves energy efficiency by changing a displacement magnification rate.

  In order to achieve the above object, according to the first aspect of the present invention, the piezoelectric actuator (14) that expands and contracts due to charging and discharging of the charge, and the nozzle needle (13) in the valve closing direction as the piezoelectric actuator (14) extends. The driven member (20-24) to be driven and the displacement of the driven member (20-24) accompanying the extension of the piezo actuator (14) are transmitted to the nozzle needle (13) by reversing the direction. Levers (25, 26), and the two types of levers (25, 26) have different lever ratios. In the process of extending the piezoelectric actuator (14), the lever ratio is mainly at the initial stage of expansion of the piezoelectric actuator (14). The nozzle needle (13) is driven in the valve opening direction by the smaller lever, and the lever ratio is large in the later stage of expansion of the piezo actuator (14). Nozzle needle (13) by gastric how levers, characterized in that it is configured to be driven in the valve opening direction.

  According to this, a direct-acting fuel injection valve in which the displacement expansion rate at the start of valve opening is small and the displacement expansion rate at the time of nozzle lift after opening the valve is increased as the piezo actuator (14) extends (ie, Therefore, the reliability of the piezo actuator (14) can be improved while improving energy efficiency.

  According to a second aspect of the present invention, in the fuel injection valve according to the first aspect, the driven member (20-24) is a bottomed cylindrical member in which the first cylinder guide hole (200) is formed. A bottomed cylindrical member having a first cylinder (20) driven by a piezo actuator (14) and a second cylinder guide hole (210), the first cylinder guide hole ( 200) and a second cylinder guide hole which is slidably inserted and driven by the pressure of the first oil tight chamber (27) formed in cooperation with the first cylinder (20). And a piston (22) that is slidably inserted into (210) and driven by the pressure of the second oil-tight chamber (28) formed in cooperation with the second cylinder (21). .

  According to this, by providing the first oil-tight chamber (27) and the second oil-tight chamber (28), the zero point correction of the positions of the piezo actuator (14) and the levers (25, 26) can be performed. In other words, it is possible to eliminate rattling in the path for transmitting displacement from the piezo actuator (14) to the lever (25, 26) in the valve closed state.

  According to a third aspect of the present invention, in the fuel injection valve according to the second aspect, the two types of levers (25, 26) include two first levers set to a predetermined lever ratio and a first lever. And two second levers set at different lever ratios, and the driven members (20 to 24) have intermediate portions in contact with the second cylinder (21) and both ends at the first levers. The first plate (23) that transmits the displacement of the second cylinder (21) to the first lever, the intermediate portion contacts the piston (22), and both end portions contact the second lever. And a second plate (24) for transmitting the displacement of the piston (22) to the second lever.

  According to this, by providing the first plate (23), the height positions of the two first levers (25, 26) can be corrected. In other words, rattling between the first plate (23) and the two first levers can be eliminated in the valve closed state. Further, by providing the second plate (24), the height positions of the two second levers can be corrected. In other words, rattling between the second plate (24) and the two second levers can be eliminated in the valve closed state.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is sectional drawing which shows the structure of the fuel injection valve which concerns on 1st Embodiment of this invention. (A) is a front view of the 1st plate of FIG. 1, (b) is a right view of (a). It is a front view of the 1st plate of FIG. It is a perspective view of the 1st lever-type drive lever of FIG. It is a perspective view of the 2nd lever-type drive lever of FIG. It is sectional drawing of the principal part in alignment with the AA of FIG. It is a figure which shows the relationship between the load which acts on a nozzle opening direction with respect to a nozzle needle, and the displacement amount of a nozzle needle. It is sectional drawing which shows the structure of the fuel injection valve which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
The fuel injection valve of the present embodiment is mounted on a cylinder head of an internal combustion engine (more specifically, a diesel engine, not shown), and high-pressure fuel stored in a pressure accumulator (not shown) is transferred into the cylinder of the internal combustion engine. It is to be sprayed on.

  In FIG. 1, the cross section shown in the left part of the center line x is different from that of the right part of the center line x by 90 degrees.

  As shown in FIG. 1, the body of the fuel injection valve is divided into a substantially cylindrical nozzle body 10 and a substantially cylindrical piezo body 11, and these bodies 10 and 11 are arranged in series in the injection valve axial direction. The retaining nut 12 is integrally held by a substantially cylindrical retaining nut 12.

  The piezoelectric body 11 has an upstream high-pressure fuel passage 110 through which high-pressure fuel supplied from the pressure accumulator flows. The nozzle body 10 is formed with a downstream high-pressure fuel passage 100 that guides the high-pressure fuel supplied via the upstream high-pressure fuel passage 110 to the tip end side of the nozzle body 10.

  A nozzle hole 101 through which high-pressure fuel supplied via the downstream high-pressure fuel passage 100 is injected into the cylinder of the internal combustion engine is formed at the tip side of the nozzle body 10. Further, a body sheet portion 102 is formed on the upstream side of the nozzle hole 101 on the tip side of the nozzle body 10.

  The substantially cylindrical nozzle needle 13 that opens and closes the nozzle hole 101 has a needle piston portion 130 slidably held in a nozzle body guide hole 103 of the nozzle body 10. The nozzle needle 13 is formed with a tapered needle seat portion 131 at an end portion (that is, a tip portion) on the nozzle hole 101 side, and the needle seat portion 131 becomes the body sheet portion 102 as the nozzle needle 13 reciprocates. The nozzle hole 101 is opened and closed by contacting and separating.

  The end of the nozzle needle 13 on the side opposite to the injection hole (that is, the rear end) protrudes from the end surface on the side opposite to the injection hole 104 of the nozzle body 10 (hereinafter referred to as the nozzle body rear end surface). The part is formed with a needle flange part 132 projecting radially outward.

  The upstream high-pressure fuel passage 110 houses a piezo actuator 14 in which a large number of piezo elements are stacked and expands and contracts due to charge / discharge. Further, in the upstream high-pressure fuel passage 110, a first cylinder 20, a second cylinder 21, a piston 22, a first plate 23, and a second plate 24 constituting a driven member are arranged. Further, a first lever 25 and a second lever 26 are disposed in the upstream high-pressure fuel passage 110.

  The first cylinder 20 has a bottomed cylindrical shape, and a first cylinder guide hole 200 is formed in the first cylinder 20. The bottom of the first cylinder 20 is in contact with the piezo actuator 14, and the first cylinder 20 is driven to close the nozzle needle 13 (downward in the drawing in FIG. 1) as the piezo actuator 14 extends. It has become.

  The second cylinder 21 has a bottomed cylindrical shape, and a second cylinder guide hole 210 is formed in the second cylinder 21. A second cylinder flange portion 211 that protrudes radially outward is formed on the opening end side of the second cylinder 21. The bottom side is slidably inserted into the first cylinder guide hole 200, and the second cylinder flange portion 211 protrudes from the first cylinder guide hole 200.

  The piston 22 has a cylindrical shape, and one end side is slidably inserted into the second cylinder guide hole 210 and the other end side protrudes from the second cylinder guide hole 210.

  As shown in FIGS. 1 and 2, the first plate 23 includes a plate-like first plate plate portion 230, a first plate through-hole 231 formed in the central portion of the first plate plate portion 230, and a first plate 23. Two plate leg portions 232 projecting from both ends of the plate plate portion 230 are provided. The two first plate legs 232 extend perpendicularly to the first plate plate 230 and in the same direction.

  The first plate 23 is disposed such that the first plate plate portion 230 abuts on the second cylinder flange portion 211 and the first plate leg portion 232 extends toward the nozzle body rear end surface 104. Further, the piston 22 extends through the first plate through hole 231 toward the second plate 24 side.

  As shown in FIGS. 1 and 3, the second plate 24 includes a plate-like second plate plate portion 240, a tapered concave portion 241 formed at the center of the second plate plate portion 240, and a second plate. Two plate leg portions 242 projecting from both ends of the plate portion 240 are provided. The two second plate legs 242 extend perpendicularly to the second plate plate 240 and in the same direction.

  The second plate 24 is arranged such that the tip of the piston 22 enters the recess 241 and the second plate leg 242 extends toward the nozzle body rear end face 104. Note that the tip of the piston 22, that is, the part that contacts the recess 241 has a spherical shape.

  As shown in FIGS. 1, 4, and 6, the first lever 25 is disposed between the first plate leg portion 232 and the needle flange portion 132 and the nozzle body rear end surface 104. Further, two first levers 25 are arranged at positions facing each other with the nozzle needle 13 interposed therebetween. One first plate leg 232 abuts on one first lever 25, and the other first plate leg 232 abuts on the other first lever 25.

  The first lever 25 is a rectangular parallelepiped, and a first lever fulcrum protrusion 250 which is in contact with the nozzle body rear end surface 104 and serves as a fulcrum is formed on a surface facing the nozzle body rear end surface 104. On the surface of the first lever 25 facing the first plate leg portion 232 and the needle flange portion 132, a first lever force point projection 251 that abuts on the first plate leg portion 232 and becomes the force point, and a needle flange portion A first lever action point protrusion 252 that is in contact with 132 and serves as this action point is formed.

  Here, the distance between the first lever fulcrum protrusion 250 and the first lever force point protrusion 251 is L1, and the distance between the first lever fulcrum protrusion 250 and the first lever action point protrusion 252 is L2. Then, the lever ratio R1 of the first lever 25 is L2 / L1.

  As shown in FIGS. 1, 5, and 6, the second lever 26 is disposed between the second plate leg portion 242 and the needle flange portion 132 and the nozzle body rear end surface 104. Further, two second levers 26 are arranged at positions facing each other with the nozzle needle 13 interposed therebetween. Furthermore, the first lever 25 and the second lever 26 are alternately arranged around the nozzle needle 13 at intervals of 90 degrees. One second plate leg 242 contacts one second lever 26, and the other second plate leg 242 contacts the other second lever 26.

  The second lever 26 is a rectangular parallelepiped, and a second lever fulcrum projection 260 that is in contact with the nozzle body rear end surface 104 and serves as a fulcrum is formed on the surface facing the nozzle body rear end surface 104. On the surface of the second lever 26 facing the second plate leg portion 242 and the needle flange portion 132, a second lever force point projection portion 261 that is in contact with the second plate leg portion 242 and becomes the force point, and a needle flange portion A second lever action point protrusion 262 that is in contact with 132 and serves as this action point is formed.

  Here, the distance between the second lever fulcrum protrusion 260 and the second lever force point protrusion 261 is L3, and the distance between the second lever fulcrum protrusion 260 and the second lever action point protrusion 262 is L4. Then, the lever ratio R2 of the second lever 26 is L4 / L3. In this embodiment, R1 <R2 is set.

  As shown in FIG. 1, a first oil-tight chamber 27 is formed by the first cylinder 20 and the second cylinder 21. The second oil-tight chamber 28 is formed by the second cylinder 21 and the piston 22.

  A first spring 29 is sandwiched between the opening end side of the first cylinder 20 and the second cylinder flange portion 211 of the second cylinder 21. The first spring 29 urges the first cylinder 20 toward the piezo actuator 14 and urges the second cylinder 21 and the first plate 23 toward the valve closing direction of the nozzle needle 13.

  A second spring 30 is disposed in the second oil tight chamber 28, and this second spring 30 biases the piston 22 and the second lever 26 toward the valve closing direction of the nozzle needle 13.

  Next, the operation of the fuel injection valve will be described. FIG. 1 shows a closed state of the fuel injection valve. At this time, the piezoelectric actuator 14 is contracted due to discharge of electric charge. The nozzle needle 13 is urged toward the valve closing direction by the fuel pressure of the upstream high-pressure fuel passage 110 acting on the rear end portion of the nozzle needle 13, and the needle seat portion 131 abuts on the body seat portion 102 and the nozzle hole 101 is closed.

  In the closed state, the fuel in the upstream high-pressure fuel passage 110 flows into the first oil-tight chamber 27 through the clearance of the sliding portion between the first cylinder 20 and the second cylinder 21. The first cylinder 20 is biased toward the piezoelectric actuator 14 by the pressure in the first oil tight chamber 27. Further, the second cylinder 21 and the first plate 23 are biased toward the first lever 25 by the pressure of the first oil-tight chamber 27. Thereby, the zero point correction of the positions of the piezo actuator 14 and the first lever 25 is performed. In other words, the rattling in the path for transmitting the displacement from the piezo actuator 14 to the first lever 25 is eliminated.

  Similarly, the fuel in the upstream high-pressure fuel passage 110 flows into the second oil-tight chamber 28 through the clearance of the sliding portion between the second cylinder 21 and the piston 22. The piston 22 and the second plate 24 are biased toward the second lever 26 by the pressure in the second oil tight chamber 28. Thereby, the zero point correction of the positions of the piezo actuator 14 and the second lever 26 is performed. In other words, the rattling in the path for transmitting the displacement from the piezo actuator 14 to the second lever 26 is eliminated.

  Further, even if the height positions of the two first levers 25 (more specifically, the height position of the top portion of the first lever force point protrusion 251) are shifted, the first plate 23 is adjusted in accordance with the shift amount. Since the posture changes, rattling between the first plate 23 and the two first levers 25 is eliminated.

  Similarly, even if the height positions of the two second levers 26 (more specifically, the height position of the top portion of the second lever force point projection 261) are deviated, the second plate 24 is matched to the deviation. Therefore, the rattling between the second plate 24 and the two second levers 26 is eliminated.

  Next, when the piezo actuator 14 is charged, the piezo actuator 14 expands, and the first cylinder 20 is driven in the valve closing direction of the nozzle needle 13 as the piezo actuator 14 extends.

  As the first cylinder 20 moves, the volume of the first oil-tight chamber 27 is reduced and the pressure in the first oil-tight chamber 27 increases. The second cylinder 21 and the first plate 23 are driven in the valve closing direction of the nozzle needle 13 by the pressure increase in the first oil tight chamber 27. As the second cylinder 21 moves, the volume of the second oil-tight chamber 28 is reduced and the pressure in the second oil-tight chamber 28 increases. The piston 22 and the second plate 24 are driven toward the valve closing direction of the nozzle needle 13 by the pressure increase in the second oil tight chamber 28.

  Then, the first lever force point protrusion 251 is pushed by the first plate leg 232, and the first lever 25 is rotated with the first lever fulcrum protrusion 250 as a fulcrum, via the first lever action point protrusion 252. The driving force of the piezo actuator 14 is transmitted to the nozzle needle 13. At this time, the first lever 25 transmits the displacement of the first cylinder 20 and the like to the nozzle needle 13 by reversing the direction, and the nozzle needle 13 is opened in the valve opening direction as the piezo actuator 14 extends (in FIG. Energize upward).

  Further, the second lever force point projection 261 is pushed by the second plate leg 242, and the second lever 26 is rotated with the second lever fulcrum projection 260 as a fulcrum, via the second lever action point projection 262. The driving force of the piezo actuator 14 is transmitted to the nozzle needle 13. At this time, the second lever 26 transmits the displacement of the first cylinder 20 or the like to the nozzle needle 13 with its direction reversed, and urges the nozzle needle 13 in the valve opening direction as the piezo actuator 14 extends.

  As described above, the nozzle needle 13 is urged in the valve opening direction through the first lever 25 and is urged in the valve opening direction through the second lever 26, but the process in which the piezo actuator 14 extends. At the beginning of expansion of the piezo actuator 14 (that is, at the start of valve opening), the nozzle needle 13 is driven in the valve opening direction mainly by the driving force transmitted through the first lever 25 having a small lever ratio. As a result, the needle seat portion 131 is separated from the body seat portion 102 to open the injection hole 101, and fuel injection into the cylinder of the internal combustion engine is started. In the present embodiment, the displacement enlargement ratio at the start of valve opening = the lever ratio of the first lever 25.

  After the opening of the valve, the driving force transmitted through the first lever 25 having a small lever ratio is rapidly reduced by the movement of the nozzle needle 13 in the opening direction, but when the valve is opened and fuel injection is started. Since the pressure of the high-pressure fuel acts on the needle seat portion 131, the nozzle needle 13 can move in the valve opening direction with a small force. Therefore, at the time of the nozzle lift after the valve opening (that is, the later stage of expansion of the piezo actuator 14), the nozzle needle 13 is moved in the valve opening direction by the driving force transmitted through the second lever 26 having a large lever ratio. The nozzle needle 13 is driven to the fully open position by the driving force transmitted through the second lever 26. In this embodiment, the displacement enlargement ratio at the time of nozzle lift after the valve opening = the lever ratio of the second lever 26.

  Thereafter, when the electric charge is discharged from the piezo actuator 14, the piezo actuator 14 contracts, and the first cylinder 20 is pushed back to the piezo actuator 14 side by the first spring 29. The movement of the first cylinder 20 increases the volume of the first oil-tight chamber 27 and the pressure of the first oil-tight chamber 27 decreases, and the second cylinder 21 moves toward the bottom side of the first cylinder 20 (that is, the nozzle Driven in the direction of opening of the needle 13). Further, the movement of the second cylinder 21 expands the volume of the second oil-tight chamber 28 and the pressure of the second oil-tight chamber 28 decreases, and the piston 22 moves toward the bottom side of the second cylinder 21 (that is, the nozzle Driven in the direction of opening of the needle 13).

  The nozzle needle 13 is driven in the valve closing direction by the pressure of the high pressure fuel acting on the rear end portion of the nozzle needle 13, the needle seat portion 131 comes into contact with the body seat portion 102, the nozzle hole 101 is closed, and the fuel injection Ends.

  Next, the fuel that changes the displacement expansion rate with respect to the characteristics related to the load acting on the nozzle needle 13 in the valve opening direction (valve opening driving force) and the displacement amount of the nozzle needle 13 when the piezo actuator 14 is charged. The characteristics in the case of an injection valve and the characteristics in the case of a fuel injection valve with a constant displacement magnification will be described.

  As shown in FIG. 7, a large load is required as indicated by point a at the start of valve opening, and a large displacement amount of the nozzle needle 14 is required as indicated by point b when the nozzle is lifted after the valve is opened.

  In the fuel injection valve of the present embodiment, when the charging energy to the piezo actuator 14 is controlled to a predetermined value, the displacement enlargement rate is small at the start of valve opening, so that a large load such as line c is obtained. At the time of subsequent nozzle lift, since the displacement enlargement ratio is large, a large displacement amount of the nozzle needle 14 as shown by the line d is obtained. And the characteristic which passes the point a and the characteristic which passes the point b can be set by setting those displacement magnification rates suitably.

  On the other hand, in the case of a fuel injection valve with a constant displacement expansion rate, if the charging energy for the piezo actuator is set to the same value as in the present embodiment, the required load at the start of valve opening and None of the required displacement during the nozzle lift can be achieved. Then, in the fuel injection valve having a constant displacement expansion rate, when trying to obtain the characteristic f passing through both points a and b, the charging energy for the piezo actuator must be made larger than in the case of this embodiment.

  Therefore, the fuel injection valve that changes the displacement expansion rate can reduce the charging energy to the piezo actuator 14 than the fuel injection valve with a constant displacement expansion rate.

  As described above, in this embodiment, since the displacement expansion rate at the time of nozzle lift after the valve opening becomes larger than the displacement expansion rate at the time of opening the valve, a large driving force is obtained at the start of valve opening, A sufficient amount of displacement of the nozzle needle 13 can be secured during the nozzle lift after the valve is opened. As a result, the charging energy to the piezo actuator 14 can be reduced as compared with the fuel injection valve having a constant displacement expansion rate. That is, energy efficiency can be improved.

  Further, since the direct-acting fuel injection valve that changes the displacement expansion rate is realized by opening the piezo actuator 14 with the extension of the piezo actuator 14 (that is, by charging the electric charge), energy efficiency is improved. However, the reliability of the piezo actuator 14 can be improved.

(Second Embodiment)
In the present embodiment, the arrangement of the first lever 25 and the second lever 26 is different from the first embodiment. In addition, since it is the same as that of 1st Embodiment regarding others, only a different part is demonstrated. Further, in FIG. 8, the cross section shown in the left part of the center line x and the right part of the center line x are different by 90 degrees.

  As shown in FIG. 8, the first lever 25 having a small lever ratio is driven by the second plate 24, and the second lever 26 having a large lever ratio is driven by the first plate 23.

  When the valve is opened, the nozzle needle 13 is driven in the valve opening direction by the driving force transmitted through the first lever 25. When the nozzle is lifted after the valve is opened, the drive is transmitted through the second lever 26. The nozzle needle 13 is driven to the fully open position by the force.

  In this embodiment, since the displacement expansion rate at the time of nozzle lift after opening the valve is larger than the displacement expansion rate at the time of starting valve opening, a large driving force can be obtained at the start of valve opening. Sometimes, a sufficient amount of displacement of the nozzle needle 13 can be ensured. As a result, the charging energy to the piezo actuator 14 can be reduced as compared with the fuel injection valve having a constant displacement expansion rate. That is, energy efficiency can be improved.

  Further, since the direct-acting fuel injection valve that changes the displacement expansion rate is realized by opening the piezo actuator 14 with the extension of the piezo actuator 14 (that is, by charging the electric charge), energy efficiency is improved. However, the reliability of the piezo actuator 14 can be improved.

DESCRIPTION OF SYMBOLS 10 Nozzle body 11 Piezo body 13 Nozzle needle 14 Piezo actuator 20 First cylinder (driven member)
21 Second cylinder (driven member)
22 Piston (driven member)
23 1st plate 23 (driven member)
24 Second plate 24 (driven member)
25 First lever 26 Second lever 100 Downstream high-pressure fuel passage 101 Injection hole 110 Upstream high-pressure fuel passage

Claims (3)

High pressure fuel passages (100, 110) through which high pressure fuel flows and injection holes (101) connected to the high pressure fuel passages (100, 110) are formed in the body (10, 11). A fuel injection valve that opens and closes at a tip surface of a nozzle needle (13),
A piezo actuator (14) that expands and contracts by charge and discharge of electric charge;
Driven members (20 to 24) driven in the valve closing direction of the nozzle needle (13) as the piezoelectric actuator (14) extends;
Two types of levers (25, 26) for transmitting the displacement of the driven members (20 to 24) accompanying the extension of the piezoelectric actuator (14) to the nozzle needle (13) by reversing the direction;
The two types of levers (25, 26) have different lever ratios,
In the process of extending the piezo actuator (14), at the initial extension of the piezo actuator (14), the nozzle needle (13) is driven in the valve opening direction mainly by the lever having a smaller lever ratio, and the piezo actuator (14) is driven. The fuel injection valve characterized in that the nozzle needle (13) is driven in the valve opening direction by the lever having the larger lever ratio in the later stage of expansion of the actuator (14). The driven members (20 to 24) are
A bottomed cylindrical member in which a first cylinder guide hole (200) is formed, the first cylinder (20) driven by the piezo actuator (14);
A bottomed cylindrical member in which a second cylinder guide hole (210) is formed, and a bottom side is slidably inserted into the first cylinder guide hole (200), and the first cylinder (20) A second cylinder (21) driven by the pressure of the first oil-tight chamber (27) formed in cooperation with
A piston (22) that is slidably inserted into the second cylinder guide hole (210) and driven by the pressure of a second oil-tight chamber (28) formed in cooperation with the second cylinder (21); The fuel injection valve according to claim 1, comprising: The two types of levers (25, 26)
Two first levers set to a predetermined lever ratio;
Two second levers set to a different lever ratio from the first lever,
The driven members (20 to 24) are
An intermediate portion abuts on the second cylinder (21), and both end portions abut on the first lever, respectively, so that the displacement of the second cylinder (21) is transmitted to the first lever (23). )When,
An intermediate portion abuts on the piston (22), and both end portions abut on the second lever, respectively, and a second plate (24) that transmits the displacement of the piston (22) to the second lever. The fuel injection valve according to claim 2.

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