JP4378877B2 - Hydraulic control valve and fuel injection valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic control valve using a piezoelectric or magnetostrictive actuator, and a fuel injection valve for an internal combustion engine incorporating the hydraulic control valve.
[0002]
[Prior art]
In a common rail fuel injection system of a diesel engine, a common rail (accumulation chamber) is provided in each cylinder, the high pressure fuel pumped from a high pressure pump is accumulated, and the fuel is injected into each cylinder at a predetermined injection timing. . In recent years, it has been proposed to use a hydraulic control valve that drives a valve body via hydraulic pressure using a piezoelectric actuator with good response as a drive source for the fuel injection valve. Such a hydraulic control valve includes, for example, a displacement expansion chamber filled with hydraulic oil between a large-diameter piston and a small-diameter piston that are displaced as the piezoelectric actuator expands and contracts, and the displacement of the large-diameter piston is detected by the displacement expansion chamber and the small-diameter piston. Enlarging and transmitting to the disc.
[0003]
The valve body selectively closes one of the high pressure port communicating with the common rail and the low pressure port communicating with the drain passage to control the back pressure of the nozzle needle of the fuel injection valve. That is, when the valve body opens the low pressure port and closes the high pressure port, the pressure in the control chamber that applies the back pressure to the nozzle needle decreases, the nozzle needle rises, and fuel is injected from the injection hole. On the other hand, when the valve body opens the high pressure port and closes the low pressure port, the pressure in the control chamber rises again, the nozzle needle descends, and fuel injection is stopped.
[0004]
By the way, in the common rail fuel injection system, in order to perform fuel injection according to the operating state of the engine, the controllability of fuel injection pressure (common rail pressure) and fuel injection rate (fuel injection amount per unit time) should be improved. is important. The common rail pressure is usually adjusted by the pumping amount from the high-pressure supply pump to the common rail, and sudden pressure reduction requests are handled by the pressure reducing valve provided on the common rail. It has been studied to perform pressure reduction control through a control valve. This is possible by lifting the valve body of the hydraulic control valve to the lift position (half lift) between the low pressure port and the high pressure port and letting the common rail fuel escape to the drain passage with the nozzle needle held closed. become. In addition, regarding the fuel injection rate, the pressure in the control chamber can be easily controlled by enabling the valve body to be half lifted, so that a small amount of fuel injection can be performed with high accuracy and an improvement in fuel injection valve performance can be expected. .
[0005]
[Problems to be solved by the invention]
However, the conventional fuel injection valve requires a large amount of energy to lift the valve body receiving the fuel pressure of the high pressure port from the low pressure port, and once the valve body is lifted, the fuel pressure also acts in the lift direction. Therefore, it is extremely difficult to stably control the valve body to the half lift position. Therefore, at present, it is difficult to perform the half lift control in the fuel injection valve to which the hydraulic control valve having the above configuration is applied.
[0006]
An object of the present invention is to enable stable half lift control in a hydraulic control valve using a piezoelectric actuator, and to improve the controllability of fuel injection valve injection rate control and common rail decompression control.
[0007]
[Means for Solving the Problems]
The hydraulic control valve according to claim 1 converts the displacement of the piezoelectric or magnetostrictive actuator into hydraulic pressure, drives the valve body by increasing or decreasing the hydraulic pressure, and connects the high pressure port and low pressure passage communicating with the high pressure passage by the valve body. One of the low-pressure ports that communicate with each other is selectively closed. The hydraulic control valve is configured to open the low-pressure port and close the high-pressure port when energy is supplied to the actuator, and to open the high-pressure port and close the low-pressure port when the energy is released. The energy required to close the high-pressure port is larger than the energy required to open the port.
[0008]
In the above configuration, when the valve body supplies energy necessary for the valve body to open the low pressure port, the valve body lifts and starts moving toward the high pressure port. However, since this energy is smaller than the energy required when closing the high pressure port, the valve body cannot close the high pressure port. That is, if the energy supplied to the actuator is set to an appropriate value lower than the energy required when closing the high pressure port, a half lift that holds the valve body between the low pressure port and the high pressure port becomes possible. The lift amount of the half lift can be stably controlled by the energy supply amount or the applied voltage to the actuator.
[0009]
In claim 1, the hydraulic control valve is specifically includes a hydraulic chamber to increase or decrease the hydraulic pressure by the displacement of the actuator, the piston member for driving the valve body by receiving the hydraulic pressure of the hydraulic chamber. The seat area of the low pressure port is S _L (mm ² ), the seat area of the high pressure port is S _H (mm ² ), the volume of the hydraulic chamber is V (mm ³ ), and the volume of hydraulic oil in the hydraulic chamber The elastic modulus is γ (Kg / mm ² ), the pressure receiving area of the piston member is s (mm ² ), the lift amount for moving the valve body from the low pressure seat to the high pressure seat is L (mm), and the high pressure When the pressure in the passage is defined as P (Kg / mm ² ), the following formula S _H · P · L + 1/2 · (S _H · P / s) ² · V / γ
> 1/2 ・ (S _L・ P / s) ²・ V / γ
Each member is configured so as to satisfy the following relationship.
[0010]
In the hydraulic control valve, the energy required to close the high pressure port is expressed as S _H · P · L + 1/2 · (S _H · P / s) ² · V / γ. On the other hand, the energy required to open the low-pressure port is 1/2 · (S _L · P / s) ² · V / γ. Accordingly, the hydraulic pressure is set so that S _H · P · L + 1/2 · (S _H · P / s) ² · V / γ> 1/2 · (S _L · P / s) ² · V / γ holds. If the control valve is configured, the above-described effect can be reliably obtained.
[0011]
Specifically, as in claim 2, the actuator is supplied with energy that is greater than or equal to the energy required when the valve element opens the low pressure port and less than the energy required when the high pressure port is closed. Thus, the valve body can be controlled to the half lift position.
[0012]
A third aspect of the present invention is a fuel injection valve comprising the hydraulic control valve according to the first or second aspect , wherein the start and stop of fuel injection are controlled by controlling the hydraulic pressure acting on the nozzle needle by driving the valve body. To do. By applying the hydraulic control valve, the fuel injection rate control by half lift and the common rail pressure depressurization control are facilitated, and a high-performance fuel injection valve can be realized.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a fuel injection valve V including a hydraulic control valve 1 to which the present invention is applied. For example, the fuel injection valve V is suitably used in a common rail injection system of a diesel engine. The fuel injection valve V opens and closes the nozzle hole 11 provided at the tip of the nozzle body B1 by the vertical movement of the nozzle needle 12 to start or stop fuel injection. The nozzle hole 11 is opened when the nozzle needle 12 is at the upper end position, is connected to the fuel reservoir 31 following the high-pressure passage 3, and is supplied with fuel. On the other hand, when the nozzle needle 12 is at the lower end position, the nozzle hole 12 is closed. The connection with the reservoir 31 is cut off, and the fuel supply is stopped. The lower end position of the nozzle needle 12 is determined by the nozzle sheet 13 on which the nozzle needle 12 is seated, and the upper end position is determined by the orifice plate P1 above the nozzle body B1.
[0014]
The nozzle body B1 is disposed at the lower end of the housing H of the valve drive device 1 via orifice plates P1 and P2, and is oil-tightly fixed by a cylindrical nozzle holder B2. The high-pressure passage 3 extends upward from the fuel reservoir 31 and communicates with the external common rail (not shown) through the orifice plates P1 and P2 and the housing H. In the housing H, a drain passage 2 is formed as a low-pressure passage for returning fuel that communicates with an external fuel tank (not shown). A control chamber 4 is formed between the upper end of the nozzle needle 12 and the orifice plate P1, and the nozzle needle 12 is always closed in the closing direction (by the spring force of the spring 41 disposed in the control chamber 4 and the hydraulic pressure of the control chamber 4). (Downward).
[0015]
The hydraulic pressure in the control chamber 4 is controlled by a three-way valve 5 that forms part of the hydraulic control valve 1. The three-way valve 5 is composed of a substantially conical valve chamber 51 formed at the lower end of the housing H and a substantially spherical valve body 52. The valve chamber 51 has a passage passing through the orifice plates P1 and P2 and a main provided at the lower end thereof. The control chamber 4 is always in communication with the orifice 42. The valve chamber 51 has two ports, a low-pressure port, a drain port 21 and a high-pressure port 32. The valve body 52 in the valve chamber 51 moves upward or downward to selectively select one of the two ports. When closed, the other is opened and connected to the control room 4. The drain port 21 communicates with the drain passage 2 via the spill chamber 22 provided above the valve chamber 51, and the high-pressure port 32 penetrating the orifice plate P2 vertically is a groove 33 provided in the lower end surface of the orifice plate P2 in the radial direction. It communicates with the high-pressure passage 3 via
[0016]
Therefore, when the valve body 52 opens the drain port 21 and closes the high pressure port 32, the fuel in the control chamber 4 flows out from the valve chamber 51 through the drain port 21. As a result, when the pressure in the control chamber 4 decreases and becomes equal to or lower than the valve opening pressure of the nozzle needle 12, the nozzle needle 12 moves away from the nozzle seat 13 and fuel is injected. On the other hand, when the valve body 52 opens the high pressure port 32 and closes the drain port 21, the pressure in the control chamber 4 is increased by the fuel flowing in from the high pressure port 32, and the nozzle needle 12 is lowered and seated on the nozzle seat 13.
[0017]
The control chamber 4 is always in communication with the high-pressure passage 3 without passing through the three-way valve 5 by the sub-orifice 43 provided in the orifice plate P 1 in communication with the lower end of the high-pressure port 32. The sub-orifice 43 causes fuel to flow into the control chamber 4 from the high-pressure passage 3 through the sub-orifice 43, thereby relaxing the pressure drop in the control chamber 4 at the start of injection and gradually opening the nozzle needle 12 to inject At the end, the pressure increase is promoted and the nozzle needle 12 is quickly closed.
[0018]
Here, the opening to the valve chamber 51 of the drain port 21 forms a conical drain seat 53, and the opening to the valve chamber 51 of the high pressure port 32 forms a flat high pressure sheet 54. ing. The reason why one side is made flat is to allow the axial displacement of the valve body 52. The valve body 52 closes the corresponding port by sitting on one of the seats 53, 54, but the pressure of the valve chamber 51 is always higher than the pressure of the drain port 21, so the valve body 52 is seated on the drain seat 53. It is a normal condition. The seating force on the high pressure seat 54 is given by the small diameter piston 18 of the hydraulic control valve 1. Next, details of the hydraulic control valve 1 will be described.
[0019]
The hydraulic control valve 1 has a piezoelectric actuator 14 housed in the upper end portion of the housing H as a drive source. The displacement of the piezoelectric actuator 14 is transmitted to the piezo piston 15 integrally provided in contact with the lower end thereof, and further transmitted to the small diameter piston 18 which is a piston member via the large diameter piston 17 and the displacement expansion chamber 6 which is a hydraulic chamber. The The piezoelectric actuator 14 has a known configuration and is formed by laminating piezoelectric materials such as PZT. The piezoelectric actuator 14 extends by supplying energy from the outside, and contracts by releasing the injected energy to drive the piezo piston 15. . The piezo piston 15 is slidably disposed in the piezo cylinder H 1 and is connected to the large-diameter piston 17 by a small-diameter rod 16. The large-diameter piston 17 and the small-diameter piston 18 are slidably disposed in the large-diameter cylinder H3 and the small-diameter cylinder H4 formed coaxially with the cylinder forming member H2, and the rod 16 is located above the upper surface of the large-diameter piston 17. And is press-fitted and fixed to the lower surface of the piezo piston 15.
[0020]
A space formed around the rod 16 below the piezo piston 15 is an oil reservoir chamber 7 communicating with the drain passage 2, and a spring 71 is accommodated to urge the piezo piston 15 upward. At the same time, the large-diameter piston 17 connected integrally with the piezo piston 15 is also urged upward by the spring 71. As a result, the piezo piston 15 and the large-diameter piston 17 move up and down integrally according to the expansion and contraction of the piezoelectric actuator 14. An O-ring 73 is provided on the outer periphery of the piezo piston 15 in order to prevent the hydraulic oil in the oil reservoir chamber 62 from contaminating the piezoelectric actuator 14. The passage for communicating the oil sump chamber 7 with the drain passage 2 is formed by forming a through hole in the oil sump chamber 7 in the radial direction from the side wall of the housing H and then closing with the blind plug 74.
[0021]
The cylinder forming member H <b> 2 has a reduced diameter portion at the upper part of the small diameter piston 18, and forms a stopper 61 that restricts the upward movement of the small diameter piston 18. The large and small cylinders H3 and H4 communicate with each other through the reduced diameter portion, and a hydraulic chamber A formed between the reduced diameter portion and the small diameter piston 18 and a hydraulic chamber formed between the large diameter piston 17. The displacement expansion chamber 6 is formed by B. The displacement expansion chamber 6 hydraulically converts the displacement of the piezoelectric actuator 14 and amplifies it according to the difference in diameter between the large and small pistons 17 and 18 (for example, 2 to 3 times the displacement of the large diameter piston 17). introduce. The lower end portion of the small-diameter piston 18 is located in a spill chamber 22 formed below the cylinder forming member H2, and a small-diameter tip portion is inserted into the drain port 21 and abuts against the valve body 52.
[0022]
A passage 72 is provided in the large-diameter piston 18 in the axial direction, and the upper end of the passage 72 extends into the base end portion of the rod 16 and branches into a T shape and opens into the oil reservoir 7. The lower end of the passage 72 opens at the lower end surface of the large-diameter piston 18 and communicates with the displacement expansion chamber 6 via a check valve 8 attached to the lower end of the large-diameter piston 18. The check valve 8 is for replenishing fuel from the oil sump chamber 7 to the displacement expansion chamber 6 when the fuel in the displacement expansion chamber 6 decreases due to leakage or the like, and is a flat valve 81 that closes the lower end opening of the passage 72. And a disc spring 82 for urging the flat valve 81 upward. The flat valve 81 and the disc spring 82 are housed and held in a bottomed cylindrical holder 83 that is press-fitted and fixed to the outer periphery of the lower end of the large-diameter piston 18. A through hole 85 is provided on the bottom surface of the holder 83, and the fuel flows freely between the space inside the holder 83 and the displacement expansion chamber 6.
[0023]
The flat valve 81 is a disk-like thin plate (thickness: 0.1 to 0.2 mm) with two upper and lower portions cut in parallel, and a pinhole 84 (diameter: 0.02 to 0.5 mm) in the center. Is provided. By this pinhole 84, even if an abnormality occurs in the energizing circuit during fuel injection, the fuel in the displacement expansion chamber 6 can be leaked to the oil sump chamber 7, so that the fuel injection can be stopped. In addition, after the fuel injection valve V is assembled, the displacement expansion chamber 6 can be easily evacuated and filled with fuel through the pinhole 84, so that air does not remain and no trouble occurs.
[0024]
The operation of the fuel injection valve having the above configuration will be described. During normal fuel injection control for full lift of the valve body 52, a sufficient voltage (for example, 100 to 150 V) is applied to the piezoelectric actuator 14 to open the drain port 21 and close the high pressure port 32 at the start of fuel injection. Is done. The piezoelectric actuator 14 generates a displacement (for example, 40 μm) proportional to the voltage, moves the piezo piston 15 and the large-diameter piston 17 downward by the same displacement amount, and increases the hydraulic pressure in the displacement expansion chamber 6. The small-diameter piston 18 descends due to the hydraulic pressure increase in the displacement expansion chamber 6, and the valve body 52 is pushed down from the drain seat 53 to be lifted and seated on the high-pressure seat 54. At this time, the lift of the valve body 52 is expanded by the area ratio (for example, twice) of the large diameter piston 17 and the small diameter piston 18 with respect to the displacement of the piezoelectric actuator 14.
[0025]
As the valve body 52 is lifted, the drain port 21 opens and then the high-pressure port 32 closes, so the pressure in the valve chamber 51 decreases. When the pressure of the control chamber 4 communicating with the valve chamber 51 decreases and the oil pressure of the fuel reservoir 31 acting upward on the nozzle needle 12 exceeds the oil pressure of the control chamber 4 and the spring force of the spring 41, the nozzle needle 12 Lifts from the nozzle sheet 13 and fuel injection is started.
[0026]
In stopping the fuel injection, the voltage of the piezoelectric actuator 14 is made zero by releasing the electric charge of the piezoelectric actuator 14. During this time, the piezoelectric actuator 14 contracts by the amount of displacement at the time of voltage application and returns to its original length, and the piezo piston 15 is urged by the spring 71 and rises. The large-diameter piston 17 connected to the piezo piston 15 by the rod 16 is also lifted together with the piezo piston 15 to lower the hydraulic pressure in the displacement expansion chamber 6. The small-diameter piston 18 loses the force that presses the valve body 52 against the high pressure of the high-pressure port 32 due to a decrease in hydraulic pressure in the displacement expansion chamber 6, and ascends together with the valve body 52.
[0027]
When the valve body 52 is seated on the drain seat 53 again and the lift position returns to the initial state, the high pressure port 32 is opened, and then the drain port 21 is closed, so that the pressure in the valve chamber 51 and the control chamber 4 is restored. . When the pressure in the control chamber 4 rises and the force acting downward on the nozzle needle 12 exceeds the oil pressure in the fuel reservoir 31, the nozzle needle 12 descends and seats on the nozzle seat 13 again to stop fuel injection. .
[0028]
Next, a case where the valve body 52 of the hydraulic control valve 1 is half lifted will be described. In the present invention, each member is set such that the energy E required for the piezoelectric actuator 14 to open the drain port 21 is smaller than the energy E ′ required for the piezoelectric actuator 14 to close the high-pressure port 32. To design. The energy supplied to the piezoelectric actuator 14 is equal to or higher than the energy E required for the piezoelectric actuator 14 to open the drain port 21 and from the energy E ′ required for the piezoelectric actuator 14 to close the high-pressure port 32. If appropriately set within a small range, the valve body 52 can be held at the half lift position between the drain port 21 and the high pressure port 32.
[0029]
FIG. 2 is a diagram schematically showing the configuration of the fuel injection valve V. As main components for transmitting the displacement of the piezoelectric actuator 14 to the valve body 52, the large-diameter piston 17, the displacement expansion chamber 6, the small-diameter Piston 18 is shown. Here, the seat area of the drain port 21 opened and closed by the valve body 52 is S _L (mm ² ), the seat area of the high-pressure port 32 is S _H (mm ² ), the diameter is d _H (mm), and the displacement expansion chamber 6 V (mm ³ ), the operating pressure when the drain port 21 is opened is p (Kg / mm ² ), the operating pressure when the high pressure port 32 is closed is p ′ (Kg / mm ² ), The volume elastic modulus of the hydraulic oil is γ (Kg / mm ² ), the pressure receiving area of the small diameter piston 18 is s (mm ² ), the diameter is d _s (mm), the pressure receiving area of the large diameter piston 17 is S (mm ² ), The lift amount for the valve body 52 to move from the drain seat 53 to the high pressure seat 54 is L (mm), the pressure of the high pressure passage 3 (= common rail pressure) is P (Kg / mm ² ), and the displacement of the piezoelectric actuator 14 is Let δ. At this time, the force F for opening the drain port 21 is expressed by the following formula (1).
(1) F = S _L · P = s · p = s · γ · (S · δ / V)
At this time, the energy E required for the piezoelectric actuator 14 is represented by the following formula (2).
(2) E = 1/2 · δ · S · p
= 1/2 · (V · S _L · P / s · γ · S) · S · (S _L · P / s)
= 1/2 ・ (S _L・ P / s) ²・ V / γ
[0030]
On the other hand, the force F ′ for closing the high-pressure port 32 is expressed by the following formula (3).
(3) F ′ = S _H · P = s · p ′ = s · γ · (S · δ ′ / V)
At this time, the energy E ′ required for the piezoelectric actuator 14 is expressed by the following formula (4).
(4) E ′ = p ′ · s · L + 1/2 · δ ′ · S · p ′
= _SH・ P ・ L + 1/2 ・ ( _SH・ P / s) ²・ V / γ
In Equation (4), S _H · P · L represents the work amount of the valve body 52, and 1/2 · (S _H · P / s) ² · V / γ represents the work of increasing pressure.
[0031]
From these formulas (1) to (4), the relationship among S _L , S _H , V, s, and L for satisfying E ′> E is expressed by the following formula (5).
(5) _SH * P * L + 1/2 * ( _SH * P / s) ² * V / γ
> 1/2 ・ (S _L・ P / s) ²・ V / γ
Therefore, if these values of S _L , S _H , V, s, and L are set so that Expression (5) is established, the high pressure port 32 is closed from the energy E for opening the drain port 21. Therefore, half lift control can be easily performed.
[0032]
Specific examples are shown below. For example, the diameter d _H of the high-pressure seat 54 = 0.5 mm, the pressure P of the common rail P = 2000 Kg / cm ² = 20 Kg / mm ² , the lift amount L of the valve body 52 = 0.03 mm, and the diameter d _s of the small diameter piston 18 = 5 mm The diameter d _L of the drain sheet 53 when the volume V of the displacement expansion chamber 6 is 5 mm ³ and the volume modulus of elasticity γ is 100 Kg / mm ² is obtained.
The seat area S _H of the high pressure port 32 and the pressure receiving area s of the small diameter piston 18 are calculated from the following equations, respectively.
S _H = π / 4 · d _H ² = π × (0.5) ² /4=0.196 (mm ² )
s = π / 4 · d _s ² = π × 5 ² /4=19.6 (mm ² )
Therefore, substituting these values into equation (5) gives
0.196 × 20 × 0.03 + 1/2 · (0.196 × 20 / 19.6) ²
· 100/5> 1/2 · (S _L · × 20 / 19.6) ² · 100/5
It becomes. Accordingly, the sheet area S _L of the drain port 21 and the diameter d _L of the drain sheet 53 are expressed as follows.
0.118 × 0.001> 0.026 · S _L ²
S _L <√ (0.119 / 0.026) = 2.14 (mm ² )
d _L <√ (4 × 2.14 / π) = 1.65 (mm)
[0033]
As described above, when the diameter d _L of the drain sheet 53 is set to be smaller than 1.65 (mm), Expression (5) is established. Then, if the voltage applied to the piezoelectric actuator 14 is set so that it is equal to or higher than the energy E for opening the drain port 21 and smaller than the energy E ′ for closing the high-pressure port 32, the high-pressure port 32 becomes Since it is not closed, the valve body 52 can be reliably held in the half lift position. Therefore, the injection rate control of the fuel injection valve using the half lift control and the decompression control of the common rail are possible, and a compact and high-performance fuel injection valve is realized.
[0034]
In the above-described embodiment, the piezoelectric actuator is used. However, the present invention is not limited to this, and a magnetostrictive actuator using a magnetostrictive element that generates displacement when energized may be used. Further, it is not necessary to use a three-way valve as the control valve, and a configuration in which the nozzle needle is opened and closed by another method such as a two-way valve may be used.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall configuration of a fuel injection valve according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram showing a schematic configuration of a fuel injection valve in the first embodiment.
[Explanation of symbols]
H Housing B1 Valve body 1 Hydraulic control valve 11 Injection hole 12 Nozzle needle 13 Nozzle seat 14 Piezoelectric actuator 15 Piezo piston 16 Rod 17 Large diameter piston 18 Small diameter piston (piston member)
2 Drain passage (low pressure passage)
21 Drain port 22 Spill chamber 3 High pressure passage 31 Fuel reservoir 32 High pressure port 4 Control chamber 5 Three-way valve 51 Valve chamber 52 Valve body 53 Drain seat 54 High pressure seat 6 Displacement expansion chamber (hydraulic chamber)
7 Oil reservoir 71 Spring 72 Passage 8 Check valve 81 Flat valve 82 Belleville spring 83 Check valve holder 84 Pin hole 85 Through hole

Claims (3)

The displacement of the piezoelectric or magnetostrictive actuator is converted to hydraulic pressure, and the valve body is driven by increasing or decreasing the hydraulic pressure, and either the high pressure port communicating with the high pressure passage or the low pressure port communicating with the low pressure passage is connected by the valve body. A hydraulic control valve that selectively closes,
A hydraulic chamber that increases or decreases the hydraulic pressure by displacement of the actuator; a piston member that receives the hydraulic pressure of the hydraulic chamber to drive the valve body; and a seat area of the low-pressure port is S _L (mm ² ), and the high-pressure port sheet area of the S _H (mm ^2), volume of V (mm ³⁾ of the hydraulic chamber, the bulk modulus of the hydraulic oil of the hydraulic chamber γ (Kg / mm ^2), a pressure receiving area of the piston member s (Mm ² ), when the lift amount for moving the valve body from the low pressure seat to the high pressure seat is L (mm) and the pressure of the high pressure passage is P (Kg / mm ² ),
_{S H · P · L + 1} /2 · (S H · P / s) 2 · V / γ
> 1/2 ・ (S _L ・ P / s) ² ・ V / γ
In relation to
When the energy is supplied to the actuator, the low pressure port is opened to close the high pressure port, and when the energy is released, the high pressure port is opened to close the low pressure port, and the energy required to open the low pressure port A hydraulic control valve characterized in that the energy required for closing the high pressure port is increased. The valve body is controlled to a half lift position by supplying the actuator with energy that is greater than energy required when the valve body opens the low pressure port and less than energy required when closing the high pressure port. Item 1. The hydraulic control valve according to Item 1. A fuel injection valve comprising the hydraulic control valve according to claim 1 or 2, wherein start and stop of fuel injection are controlled by controlling a hydraulic pressure acting on a nozzle needle by driving the valve body.

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