JP2000337304A - Valve device and hydraulic actuator control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a load hold check valve or drift reducing valve in a meter-in/meter-out separation type control circuit to control the working fluid of a hydraulic actuator. SOLUTION: Meter-in valves A1IMV and A2IMV of a bridge circuit installed in a passage leading from a pump 1 to a hydraulic actuator 2 are configured so that a poppet valve 41 is provided in such a way as contacting with and separating from a seat part 49 and a spring chamber 51 is provided oppositely to the part 49 about the poppet valve 41, wherein the chamber 51 is fitted with a built-in spring 52 to press the poppet valve 41 to the seat part 49. A high pressure selecting means selects either the pressure in the passage 13 on the pump side or the pressure in the passage 15 on the actuator side, whichever is the higher, and leads it to the spring chamber 51. A pilot spool valve 54 is formed with a smaller diameter than the poppet valve 41 so as to control the rate of pilot flow flowing out from the spring chamber 51 to either the passage 74 on the side nearer the pump than the poppet valve 41 or the passage 73 on the actuator side, whichever is the lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve device using a poppet valve and a control device for a fluid pressure actuator.

[0002]

2. Description of the Related Art FIG. 11 shows a meter-in / meter-out type control circuit provided in a conventional construction machine such as a hydraulic excavator.
Cylinder type hydraulic actuator 2 for driving load W
Between them, there is provided a bridge circuit 3 including two meter-in valves A1IMV and A2IMV and two meter-out valves A3IMV and A4IMV.

Further, a load hold check valve 4 is provided in a passage between the pump 1 and the bridge circuit 3, and a drift preventing leak is provided in two passages between the bridge circuit 3 and the hydraulic actuator 2. Reduction valves (pilot-operated check valves) 5 are provided.

[0004] A bridge circuit (not shown) for controlling another fluid pressure actuator (not shown) is similarly connected to the discharge port of the pump 1 through a passage 6.

Further, between the discharge port of the pump 1 and the tank 7, one common bypass valve 8, which is controlled in conjunction with the control of the bridge circuit 3 of the plurality of fluid pressure actuators 2, and a pump, A main relief valve 9 for setting the discharge pressure is provided.

Meter-in valves A1IMV, A2IMV, meter-out valves A3IMV, A4IMV and common bypass valve 8
Is an open / close valve with a middle throttle notch of a spool valve type. The spool valve stroke is controlled by an electromagnetic actuator which is operated by an electric signal output from a controller (not shown) according to the operation amount of an operation lever. Is done.

In this circuit, for example, when the fluid pressure actuator 2 is extended against the load W, the drift reducing valve 5 is opened, the meter-in valve A1IMV and the meter-out valve A4IMV are closed, and the variable displacement pump is closed. 1, the control is performed so that the common bypass valve 8 is gradually closed, and the meter-in valve A2IMV and the meter-out valve A3IMV are gradually opened.

On the other hand, when the fluid pressure actuator 2 is contracted, the discharge amount of the variable displacement pump 1 is gradually increased while opening the drift reduction valve 5 and closing the meter-in valve A2IMV and the meter-out valve A3IMV. At the same time, control is performed such that the common bypass valve 8 is gradually closed, and the meter-in valve A1IMV and the meter-out valve A4IMV are gradually opened. Such control is performed by an operation lever (not shown) via a controller.

Normally, in this control circuit, a state in which the load W is stopped (stalled) by the resistance of the ground G or the like due to extension of the fluid pressure actuator 2, for example, when a stick cylinder of a hydraulic shovel is operated in a stick-in manner. , The control pressure of the head side chamber 2h located on the cylinder head side of the fluid pressure actuator 2 is controlled by the opening degree of the common bypass valve 8 and the pump discharge amount by the operation amount of the operation lever (bleed-off control). For example, it changes as shown by a dotted line in FIG. 9, and this change becomes substantially common and fixed for a plurality of fluid pressure actuators.

For this reason, the most preferable pressure modulation curve for each fluid pressure actuator, for example, FIG.
It is difficult to individually realize the pressure modulation curves indicated by the solid line and the one-dot chain line.

Further, when the operating lever is fully operated and the corresponding fluid pressure actuator 2 is in the stall state, the pump discharge pressure is increased to the set pressure of the main relief valve 9 by closing the common bypass valve 8. Sometimes, even if an attempt is made to perform modulation control on a bridge circuit for another fluid pressure actuator, the pump discharge pressure has already risen to the main relief pressure due to the closing of the common bypass valve 8 and cannot be controlled. When the meter-in side of the actuator is opened, there is a disadvantage that the high pressure wraps around as shown by the one-dot chain line in FIG. 9 and the pressure modulation characteristic cannot be selected.

As shown in FIG. 10, the operation speed of the hydraulic actuator 2 is controlled by a solid line for one hydraulic actuator and a dotted line or a dashed line for another hydraulic actuator. Although it is desirable to control the velocity modulation curve to be ideal and optimal, it is difficult to interfere with each other.

In addition, a load hold check valve 4 for maintaining load pressure and a drift reducing valve 5 for reducing leakage from a spool valve constituting the bridge circuit 3 are required. Particularly, conventionally, since the bridge circuit 3 is constituted by a spool valve, it is necessary to form the spool with a large diameter in order to secure a required flow rate. With this large-diameter spool valve, the amount of leak cannot be ignored. So many
Drift reduction valve 5 was essential.

[0014]

As described above, in the conventional meter-in / meter-out separated control circuit, it is difficult to realize a pressure modulation curve and a speed modulation curve corresponding to the fluid pressure actuator 2 and the load is increased. There is a problem that a load hold check valve 4 for maintaining pressure and a drift reduction valve 5 for reducing leakage at the spool valve of the bridge circuit 3 are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to eliminate the need for a load hold check valve and a drift reduction valve, and to provide a meter-in for controlling a working fluid of a hydraulic actuator. In a meter-out separated control circuit, it is an object of the present invention to achieve a pressure modulation characteristic and a velocity modulation characteristic that can be controlled by an operator by operating a lever most suitable for the hydraulic actuator. .

[0016]

According to a first aspect of the present invention, there is provided a poppet valve for controlling a working fluid supplied from a pump to a fluid pressure actuator, and a pressure chamber for applying pressure in a direction to close the poppet valve. And a high-pressure selecting means for selecting a higher pressure between the pump discharge pressure and the load pressure on the fluid pressure actuator side and guiding the selected pressure to the pressure chamber.

The load pressure on the side of the fluid pressure actuator higher than the discharge pressure of the pump is guided to the pressure chamber by the high pressure selecting means, so that the poppet valve capable of controlling the flow rate also has a load hold check valve function. Can be omitted, and the valve housing can be made compact.

According to a second aspect of the present invention, there is provided a poppet valve for controlling a main flow rate, a pressure chamber for applying pressure in a direction to close the poppet valve, and a poppet for controlling a pilot flow rate discharged from the pressure chamber. And a pilot spool valve having a smaller diameter than the valve.

The main flow rate is controlled by a poppet valve which does not easily cause a leak, and the pilot flow rate from the pressure chamber of the poppet valve is controlled by a small-diameter pilot spool valve having a small leak amount. The leak amount is reduced as compared with the conventional case where the main flow rate is controlled by a large-diameter spool valve having

According to a third aspect of the present invention, there is provided a pump,
3. A pump-side two meter-in valve using a valve device according to claim 2, which is provided between the pump and the hydraulic actuator, the hydraulic actuator being operated by a working fluid discharged from the pump. It is a control device for a fluid pressure actuator including a bridge circuit formed by two meter-out valves on the actuator side, and a controller for controlling the meter-in valve and the meter-out valve.

A meter-in valve and a meter-out valve using a pilot flow amplification type poppet valve are combined to form a bridge circuit for controlling a fluid pressure actuator, and these meter-in valve and meter-out valve are controlled by a controller. Because of the control, it is possible to control the direction and the flow rate of the fluid pressure actuator, and to prevent the leakage that is required when the main flow rate is controlled by a conventional bridge circuit composed of, for example, a large-diameter spool valve having the same diameter as a poppet valve. Drift reduction valve can be eliminated.

According to a fourth aspect of the present invention, there is provided a control device for a hydraulic actuator, wherein the controller in the control device for the hydraulic actuator according to the third aspect controls both of the two meter-in valves to open.

By controlling the two meter-in valves to open together, the working fluid is regenerated from one meter-in valve to the other meter-in valve.

According to a fifth aspect of the present invention, in the control device for a fluid pressure actuator according to the third or fourth aspect, the meter-in valve is provided between the pump and the fluid pressure actuator. A poppet valve capable of bidirectional flow control, which is provided on the seat part so as to be able to contact and separate,
A spring chamber located on the opposite side of the seat portion with respect to the poppet valve, a spring built in the spring chamber to press the poppet valve against the seat portion, a pressure in a passage on a pump side and a pressure in a passage on a fluid pressure actuator side. High pressure selecting means for selecting a high pressure in the spring chamber and guiding it to the spring chamber, and a pilot spool smaller in diameter than a poppet valve for controlling a pilot flow rate discharged from the spring chamber to a low pressure side of a passage on the pump side and a passage on the fluid pressure actuator side. A control device for a fluid pressure actuator comprising a valve. The high-pressure selecting means may be built in the poppet valve, or may be installed outside the poppet valve, for example, in a valve housing enclosing the poppet valve.

The high pressure selecting means selects a high pressure between the pressure of the passage on the pump side and the pressure of the passage on the side of the fluid pressure actuator and guides it to the spring chamber. The pilot spool valve controls the pilot flow discharged to the low pressure side with the passage, and the poppet valve can perform bidirectional flow control. When the pressure in the passage on the side of the fluid pressure actuator is high, the pressure is guided to the spring chamber through the high pressure selecting means. At this time, when the pilot spool valve is in the closed position, the internal pressure of the spring chamber causes the poppet valve to seat. Since the pressure on the pump side passage is high, the pressure is guided to the spring chamber through the high pressure selection means, and the pilot spool valve is displaced at this time. The pilot flow is discharged from the spring chamber to the passage on the fluid pressure actuator side through the pilot spool valve in accordance with the amount of displacement of the spool valve, and the pressure in the spring chamber is reduced in accordance with the pilot flow, and the poppet valve is opened. A pilot flow amplification operation in which the degree is controlled is obtained. In addition, when the pilot spool valve is in the neutral closed position, the load pressure acts on the spring chamber via the high pressure selecting means, but the pilot spool valve having a smaller diameter than the poppet valve can reduce the amount of leakage, thus reducing the conventional drift reduction. The valve can be abolished.

According to a sixth aspect of the present invention, in the control apparatus for a fluid pressure actuator according to the fifth aspect, an electromagnetic actuator for axially propelling the pilot spool valve, and the pilot spool valve is set at a neutral position with respect to the electromagnetic actuator. A biasing pilot spring, a spool valve stroke detection sensor for detecting a displacement amount of the pilot spool valve, and a load pressure receiving surface provided on the pilot spool valve and receiving a load pressure on the fluid pressure actuator side,
The controller determines the thrust from the current value supplied to the electromagnetic actuator, calculates the spring force from the axial displacement of the pilot spool valve detected by the spool valve stroke detection sensor, and calculates the thrust and spring force of the electromagnetic actuator. The load pressure applied to the load pressure receiving surface of the pilot spool valve is calculated by dividing the difference of the pressure by the area of the load pressure receiving surface, and the pressure modulation curve representing the change of the supply pressure to the fluid pressure actuator with respect to the manipulated variable is calculated. Is a control device for a fluid pressure actuator that controls according to the following.

Since the load pressure can be calculated from the current value and the displacement of the electromagnetic actuator that drives the pilot spool valve having the load pressure receiving surface for load pressure feedback, a pressure sensor for detecting the load pressure is not required. A plurality of hydraulic actuators can be individually controlled with suitable pressure modulation characteristics.

According to a seventh aspect of the present invention, in the control apparatus for a fluid pressure actuator according to the sixth aspect, a pump discharge pressure sensor for detecting a pump discharge pressure of a working fluid discharged from the pump, and a displacement of the poppet valve. An opening area monitoring means for monitoring the opening area of the poppet valve from the amount, wherein the controller calculates the pump discharge pressure applied to the poppet valve detected by the pump discharge pressure sensor and the load pressure receiving surface of the pilot spool valve. The differential pressure applied to the poppet valve is calculated from the obtained load pressure value applied to the poppet valve, and the operation supplied to the fluid pressure actuator based on the differential pressure and the opening area of the poppet valve detected by the opening area monitoring means. Calculates the flow rate of the fluid and flows through a velocity modulation curve representing the change in the speed of the hydraulic actuator with respect to the manipulated variable. A control device for a fluid pressure actuator for controlling in response to the pressure actuator.

By controlling the differential pressure applied to the poppet valve and the opening area of the poppet valve, a plurality of hydraulic actuators can be individually controlled with suitable speed modulation characteristics. In particular, even if another hydraulic actuator stalls (stops) and, for example, the pump reaches a high pressure determined by the main relief valve, the above-mentioned structure for feeding back the load pressure and the opening area monitoring means make it possible to control each hydraulic actuator. Suitable speed control and pressure control can be achieved individually. This effect can be obtained even when a plurality of hydraulic actuators are operated independently or simultaneously.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 and 2, and another embodiment will be described with reference to FIGS. 3 and 4. FIG. Will be described with reference to FIGS. 5, 6, 7 and 8. FIG.

First, an embodiment shown in FIGS. 1 and 2 will be described. The same parts as those of the conventional control circuit shown in FIG. 11 are denoted by the same reference numerals.

FIG. 2 shows meter-in valves A1IMV and A2IMV.
A bridge circuit 3 in which a meter-in / meter-out valve A3IMV and A4IMV are combined to form a meter-in / meter-out type control circuit. A pump discharge passage 11 is connected to the pump discharge passage 11, and passages 12 and 13 communicating with two meter-in valves A1IMV and A2IMV of one bridge circuit 3 for controlling one hydraulic actuator 2 of a cylinder type are respectively provided. Also connected to the pump discharge passage 11 is a passage 6 communicating with another bridge circuit (not shown) for controlling another fluid pressure actuator (not shown).

Further, the pump 1
A common bypass valve 8 for controlling the supply amount of the working fluid discharged from each of the bridge circuits 3 and a main relief valve 9 for setting an upper limit of the pump discharge pressure are provided in common for the plurality of bridge circuits 3. I have.

Each bridge circuit 3 has two meter-in valves A1IMV and A2 connected to a pump discharge passage 11 through passages 12 and 13.
Each IMV is connected and these meter-in valves A1
Two meter-out valves A3IMV and A4IMV for controlling between the passages 14 and 15 and the tank passages 16 and 17 are connected to the IMV and A2IMV, respectively, and the tank passages 16 and 17 are connected to the tank 7.

Further, the meter-in valve A1IMV and the meter-out valve A3
The passage 14a drawn through the IMV is connected to a chamber (hereinafter, referred to as a chamber) on the rod side of the piston 2p of the fluid pressure actuator 2.
"Rod side chamber 2r"), and the meter-in valve A2IMV and meter-out valve
The passage 15a drawn through the A4IMV is connected to a chamber (hereinafter, referred to as "head side chamber 2h") located closer to the head than the piston 2p of the fluid pressure actuator 2.

Each of the meter-out valves A3IMV, A4IMV
To be more specific, a pilot flow amplification type poppet valve provided in the valve housing 21 (hereinafter, this poppet valve is referred to as a "meter-out poppet valve 22").
And a meter-out side poppet valve in a valve chamber 23 formed in the valve housing 21.
Numerals 22 are provided to be displaceable, respectively, and return passages 14a, 15a from the fluid pressure actuator 2 are respectively connected to the respective valve chambers 23.

On the side surfaces of these meter-out side poppet valves 22, variable slots 25 whose opening areas are proportionally enlarged and changed as the axial displacement of each meter-out side poppet valve 22 are increased. It is formed in the axial direction.

The variable slots 25 are provided in a state where the drain flow control units 26 formed at the opposite ends of the respective meter-out side poppet valves 22 are seated on the seat 27.
The valve housing 21 has a slight opening 25a communicating with a spring chamber 28 formed therein. Each seat part
27 is connected to the tank 7 by tank passages 16 and 17, respectively.

Each of the spring chambers 28 for the meter-out side poppet valve 22 is provided with a drain flow control section 26 and a seat section 27.
A compression coil spring 29 that presses in the direction of pressing toward the side, that is, in the closing direction, is respectively incorporated.

As means for controlling the degree of opening of each meter-out side poppet valve 22, each spring chamber 28 is connected to each tank passage.
A passage 31 and a passage 32 are drawn out over 16 and 17, respectively, and a modulation stem 33 is interposed in each passage 31, respectively.
Drain control of each spring chamber 28 is performed in accordance with an electric signal from a controller (not shown). A coil spring 34 is provided for each modulation stem 33, and a modulation stem 33
And an electromagnetic actuator 35 for controlling the position of each.

Further, passages 36 are provided in parallel with the respective passages 31. In these passages 36, pilot poppet valves 37 each having a relief valve function for preventing overload are interposed.

Each of these pilot poppet valves 37 is provided with a compression coil spring 38 and an electromagnetic actuator 39 acting in a direction to close each pilot poppet valve 37 in parallel, and a return passage 14a from the fluid pressure actuator 2 is provided. , 15a are guided by passages 40 to the opposite sides of the pilot poppet valves 37, respectively.

Thus, when an excessive load pressure is generated in the return passages 14a and 15a from the fluid pressure actuator 2, each pilot poppet valve 37 opens against the thrust of the compression coil spring 38 and the electromagnetic actuator 39, and each pilot poppet valve 37 opens. By controlling the drainage of the spring chamber 28 of the meter-out side poppet valve 22, the seat portion of each meter-out side poppet valve 22 is controlled.
27 are respectively opened. Each electromagnetic actuator 39 has a function of variably controlling a set pressure as a relief valve.

In each of the meter-out side poppet valves 22 configured as above, a part of the return flow Q from the fluid pressure actuator 2 flows into the spring chamber 28 through the opening 25 a of the pilot variable slot 25. . The stroke control of the meter-out side poppet valve 22 is achieved by controlling the opening degree of a modulation stem 33 communicating with the spring chamber 28, and the flow rate passing through the modulation stem 33 is q in the figure.
Indicated by ₂ . Incidentally, the pilot flow rate q ₁ towards the pilot poppet valve 37 is zero at the time of closure of the pilot poppet valve 37, at that time becomes q = q _2.

By controlling the stroke of the meter-out side poppet valve 22, the drain flow control unit 26 controls the opening degree of the valve seat 27, so that the main flow rate LQ is controlled.
This main flow rate LQ is as if the modulation stem 33
Shows the appearance of the pilot flow rate q ₂ is amplified at.

Meanwhile, this was modulation stem 33 is closed, when the flow rate q ₂ also has a main flow LQ even zero value, than the fluid pressure actuator 2 return passages 14a, 15a
When the return pressure of the piston poppet rises and the force acting on the pilot poppet valve 37 via the passage 40 overcomes the thrust of the compression coil spring 38 and the electromagnetic actuator 39, the pilot poppet valve
37 is open, the pilot flow rate q ₁ starts to flow (in this case becomes q = q _1), the pressure difference is generated in the front and rear openings 25a of the variable slot 25 of the meter-out poppet valve 22, the meter-out side poppet valve 22 moves to the spring chamber 28 side, and the seat 27
Is opened, and the return pressure of the return passage 14a or 15a from the fluid pressure actuator 2 is suppressed from abnormally rising due to the generation of the main flow rate LQ, and the compression coil spring 38 and the electromagnetic actuator acting substantially on the pilot poppet valve 37 are suppressed. It has a relief valve function to settle at a constant pressure value set by 39 thrusts.

Next, the meter-in valves A1IMV and A2IM
V is configured around a meter-in side poppet valve 41 as a pilot flow rate amplification type poppet valve provided inside the valve housing 21, and this point is the same as the meter-out valves A3IMV and A4IMV. The structure of the meter-in side poppet valve 41 itself and its pilot control means are different from the meter-out valves A3IMV and A4IMV.

Since the structures of the meter-in valves A1IMV and A2IMV are the same, the meter-in valve A2IMV on the cylinder head side will be described in detail here as an example.
As shown in the above, the meter-in side poppet valve 41,
In FIG. 1, a shuttle valve 42 as a high pressure selecting means is provided inside, and a passage 43 formed on one inlet side of the shuttle valve 42 is a passage communicated with the discharge port of the pump 1 via the pump discharge passage 11. 13, a passage 44 formed on the other inlet side of the shuttle valve 42 for guiding the pump discharge pressure to the shuttle valve 42, and an annular passage communicating with the head side chamber 2h of the fluid pressure actuator 2 via the passage 15 is provided. Opened in the space 45, the pressure supplied to the hydraulic actuator 2 or the load pressure of the hydraulic actuator 2 is guided to the shuttle valve 42, and the shuttle valve 42 selects the higher pressure side among these pressures.

A passage 46 in the poppet valve formed on the output side of the shuttle valve 42 communicates with a variable slot 47 formed on the outer periphery of the meter-in side poppet valve 41. The opening area of the variable slot 47 increases in accordance with the movement stroke of the meter-in side poppet valve 41.

The variable slot 47 communicates with a spring chamber 51 as a pressure chamber formed in the valve housing 21 when the flow control unit 48 of the meter-in side poppet valve 41 is seated on the seat 49. Has an opening 47a.

The spring chamber 51 for the meter-in side poppet valve 41 has a flow control unit 48 of the meter-in side poppet valve 41.
Compression spring 52 as a spring for pressing the
The spring chamber 51 is communicated by a passage 53 with a fitting hole 55 in which a pilot spool valve 54 is slidably fitted.

The stroke of the pilot spool valve 54 is controlled by a push-pull actuator 56 as an external electromagnetic actuator.

In the push-pull actuator 56, a coil 58 is fitted in an actuator body 57 fixed to the valve housing 21, and a core 59 provided integrally with one end of the pilot spool valve 54 is provided in the coil 58. It is movably fitted, and it is possible to obtain an exciting force that urges the pilot spool valve 54 in a direction of pulling out the pilot spool valve 54 from the valve housing 21 and a direction of pushing the pilot spool valve 54 into the valve housing 21 depending on the direction of current supply to the coil 58. .

The other end of the pilot spool valve 54 is inserted into a spring chamber 61 formed in the valve housing 21 and has a locking portion 62 that moves integrally in the spring chamber 61. A compression coil spring 64 serving as a pilot spring is provided between the pair of engagement flanges 63 engaged with the other end of 54 and the locking portion 62, and each compression flange 63 is moved by the compression coil spring 64 into a spring chamber 61. Are applied to the pilot spool valve 54 at a neutral position.

A first land portion 67 and a second land portion 68 are formed in the pilot spool valve 54 via an intermediate groove 66, and a first land 67 is provided on the intermediate groove 66 side of the first land 67. A metering notch 69 is provided, and an intermediate groove 66 of the second land portion 68 is provided.
A second metering notch 70 is provided on the side, and a spring chamber 51 communicates with the meter-in side poppet valve 41 by the passage 53 on the upstream side of the metering notches 69 and 70.

On the other hand, these metering notches 69, 70
The annular spaces 71, 72 are respectively provided at positions downstream of the pilot spool valve 54 at a position where a fixed cutoff distance can be secured from the metering notches 69, 70 when the pilot spool valve 54 is at the illustrated neutral position. Is connected to the passage 15 to the fluid pressure actuator 2 via a passage 73, and the other annular space 72 is connected to the pump discharge passage 11 via a passage 74.

Therefore, the push-pull actuator
When the piston 56 is excited and moves in the direction in which the pilot spool valve 54 is pushed against the spring force of the compression coil spring 64, the metering notch 69 provided on the first land 67 of the pilot spool valve 54 becomes annular. Open to space 71, passage
Because it communicates with 73, the spring chamber of the meter-in side poppet valve 41
The passage 51 communicates with the supply passage 15 to the fluid pressure actuator 2 via the passage 53, the intermediate groove 66, the metering notch 69, the annular space 71, the passage 73, and the annular space 45.

On the other hand, when the push-pull actuator 56 is excited in the opposite direction and moves in the direction in which the pilot spool valve 54 is pulled out against the spring force of the compression coil spring 64,
The metering notch 70 provided on the second land 68 of the pilot spool valve 54 opens into the annular space 72 and communicates with the passage 74, so that the spring chamber 51 of the meter-in side poppet valve 41
Is connected to the pump discharge passage 11 through a passage 53, an intermediate groove 66, a metering notch 70, an annular space 72, and a passage 74.

Further, the meter-in side poppet valve 41 is provided with a poppet valve stroke detection sensor 75 as an opening area monitoring means capable of monitoring the opening area of the poppet valve 41 by detecting its operation stroke.
That is, the stroke detection sensor 75 is provided at the center of the meter-in side poppet valve 41 with a movable core 76 such as an operating transformer.
Are integrally fitted, and a coil 77 such as an operation transformer is fitted to the valve housing 21 so as to surround the movable iron core 76. And this poppet valve stroke detection sensor
The amount of displacement of the meter-in side poppet valve 41 is detected by 75, and the opening area of the seat portion 49 is monitored based on the amount of displacement.

Further, the push-pull actuator
The space in the actuator body 57 of 56 is communicated with a lower spring chamber 61 by a drain hole 78 formed in the pilot spool valve 54, and the interior of the spring chamber 61 is externally connected by a drain hole 79. To prevent the high pressure from acting on both ends of the pilot spool valve 54.

Next, the operation and effect of the embodiment shown in FIGS. 1 and 2 will be described.

When an operation lever (not shown) is operated, an electric signal transmitted from the operation lever is processed by a controller, and the electric signal such as a current value output from the controller is used to generate the common bypass valve 8 and the meter-in valve A1IMV. , A2IMV push-pull actuator 56
The electromagnetic actuators 35 of the meter-out valves A3IMV and A4IMV are controlled to be excited or de-energized, respectively, and supplied from the pump 1 to one of the rod side chamber 2r and the head side chamber 2h of the fluid pressure actuator 2 and discharged from the other to the tank 7. Hydraulic oil has two meter-in valves
A1IMV, A2IMV and two meter-out valves A3IMV
, A4IMV. Since the control example relating to the cylinder expansion and contraction has already been described, it is omitted here.

(1) Leak Reduction Function When the operation lever (not shown) is in the neutral position and a command (current value) is not given to each push-pull actuator 56, the pilot spool valve 54 is turned on as shown in FIG. Thus, in the neutral position, the first and second metering notches 69, 70 are both closed.

Since the common bypass 8 is open and the pump discharge from the variable displacement pump 1 is also minimal, the pressure in the passage 13 is low.

In this case, if a holding pressure higher than the pressure in the passage 13 is present in the head side chamber 2h of the cylinder type hydraulic actuator 2, a high pressure is selected from the passage 15 by the shuttle valve 42, and this holding pressure is changed to the variable slot 47. Is introduced into the spring chamber 51 from the opening 47a of the valve, and presses the meter-in side poppet valve 41 toward the seat portion 49 together with the spring force of the compression coil spring 52.

Therefore, unlike the case where a spool valve having a diameter substantially equal to that of the poppet valve 41 is used as a meter-in valve, a leak from the passage 15 through the large-diameter annular gap to the passage 13 does not occur. However, although there is some leakage from the annular gap of the small-diameter pilot spool valve 54, this leakage is small because the spool valve diameter is small and the overlap of the metering notches 69 and 70 is large. It can be.

(2) Load Hold Check Valve Function The operation lever is operated, the common bypass valve 8 is closed, the pump discharge amount is increased, and a command (current value) is sent from the controller (not shown) to the push-pull actuator 56. When supplied and acts in the direction of pushing the pilot spool valve 54, the metering notch 69 opens the passage 53 and the passage 73.

At this time, if the pressure of the passage 15 is still higher than the pressure of the passage 13, the spring chamber 51 of the meter-in side poppet valve 41 is equal to the pressure of the high-pressure side passage 15, and this poppet valve
41 remains closed, which functions as a load hold check valve.

Further, when the common bypass valve 8 is closed and the pump discharge amount increases, the pump discharge pressure of the passage 13 eventually increases beyond the pressure of the passage 15.

At this time, the pressure on the passage 13 side is selected to be high by the shuttle valve 42 and acts on the metering notch 69 from the spring chamber 51 of the poppet valve 41, and this pressure is applied to the pressure (=
Therefore, a pilot flow is generated from the passage 53 toward the passage 73 at the notch 69.

Since the meter-in side poppet valve 41 has a pilot flow rate amplifying function, the pressure in the spring chamber 51 decreases as the pilot flow rate increases, and the flow rate control section 48 of the meter-in side poppet valve 41 changes the seat section. Lifting from 49, a controlled main flow from the passage 13 to the passage 15 is generated by the gradual increase in the opening area of the valve tip, and the cylinder-type fluid pressure actuator 2 gradually expands.

(3) Regeneration Function In FIG. 2, when the cylinder-type fluid pressure actuator 2 is contracted, energy may be regenerated to the pump supply unit by using the holding pressure of the head side chamber 2h. In other words, by opening the meter-in valve A1IMV, closing the meter-out valve A3IMV, partially opening the meter-out valve A4IMV, and fully opening the meter-in valve A2IMV, a part of the return flow from the head side chamber 2h can be reduced. Reverse the flow from the meter-in valve A2IMV to the pump side to join the pump supply oil.

In the meter-in valve A2IMV of FIG. 1, a controller (not shown) supplies current to the coil 58 of the push-pull actuator 56 in the direction of pulling out the pilot spool valve 54 (upward in the figure), and the metering notch 70 And the passage 74 are communicated.

At the time of this regeneration, since the holding pressure of the head side chamber 2h of the fluid pressure actuator 2 is higher than the pressure of the passage 13,
From the passage 15, it reaches the passage 53 via the shuttle valve 42, the variable slot 47 and the spring chamber 51 in FIG. 1, and is higher than the pressure in the passage 74 (= pressure in the passage 13). A pilot flow is generated to 74, the poppet valve 41 is opened by the pilot flow amplification function of the meter-in side poppet valve 41 due to the pressure reduction of the spring chamber 51, and the main flow controlled by the poppet valve lift amount from the passage 15 to the passage 13 is reduced. It is generated, merged and regenerated with the pump discharge oil, and supplied to the meter-in valve A1IMV via the passage 12.

As another regenerating method, when both the meter-in valves A1IMV and A2IMV are opened and both the meter-out valves A3IMV and A4IMV are closed, the piston 2p having a different pressure receiving area causes the piston rod to move due to the pump discharge pressure. Although it moves in the protruding direction, at this time, the hydraulic oil extruded from the rod side chamber 2r is regenerated to the head side chamber 2h.

Next, another embodiment shown in FIGS. 3 and 4 will be described. The same parts as those in the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 shows a load pressure feedback type meter-in valve A2IMV ', and the meter-in side poppet valve 41 thereof.
Spool valve that controls the opening (stroke) of the valve
The stroke 54 is controlled by the same push-pull actuator 56 and the spring reaction force of the compression coil spring 64 as in FIG.

A spool valve stroke detection sensor 81 for detecting the stroke of the pilot spool valve 54 is provided. This spool valve stroke detection sensor 81
Actuator body 57 of push-pull actuator 56
A coil 82 such as a differential transformer is fitted in the
An iron core 83 integral with the pilot spool valve 54 is movably fitted in the core 82 via the core 59.

Further, the passage 73 communicating with the passage 15 is guided to a position below the metering notch 69 via the first land 67 of the pilot spool valve 54 and the first land of the pilot spool valve 54 is formed. At 67, a small-diameter step on the lower side in FIG. 3 is formed in a portion facing the middle of the passage 73, so that an annular step-shaped donut area-shaped load pressure receiving surface 84 is formed in this portion. Therefore, the supply pressure to the fluid pressure actuator 2 in the passage 15 or the load pressure of the fluid pressure actuator 2 acts on this donut area-shaped load pressure receiving surface 84 via the passage 73, and the fluid is applied to the push-pull actuator 56. The load pressure of the pressure actuator 2 is configured to be fed back.

Further, there is provided a controller 85 having a built-in central processing unit (CPU).
An operation signal related to the operation amount from the operation lever 86 as an input signal, a pump discharge pressure signal from a pump discharge pressure sensor 87 that detects a pump discharge pressure provided in the pump discharge passage 11,
The spool valve stroke signal from the spool valve stroke detection sensor 81 and the poppet valve stroke signal from the poppet valve stroke detection sensor 75 for detecting the stroke of the poppet valve 41 are obtained, and each meter-in valve A1IMV,
A control current is output to the push-pull actuator 56 of A2IMV, the electromagnetic actuators 35 and 39 of meter-out valves A3IMV and A4IMV, the common bypass valve 8, and the electromagnetic actuator 88 for controlling the pump discharge amount.

FIG. 4 shows a load pressure feedback meter-in valve A2IMV 'shown in FIG. 3, a load pressure feedback meter-in valve A1IMV' having a similar structure, and a meter-out valve A3IMV shown in FIG. , A4IMV in combination with a hydraulic circuit diagram of a bridge circuit 3 '.

Next, the operation and effect of the embodiment shown in FIGS. 3 and 4 will be described.

First land portion of pilot spool valve 54
By providing a step in 67, a load pressure receiving surface 84 in the form of a donut area is provided, and the pressure in passage 73, that is, the load pressure in passage 15 is applied in the direction in which pilot spool valve 54 is pushed out.

While the pump discharge oil is being metered from the passage 13 to the passage 15, the push-pull actuator 56 pushes the metering notch 69 in the opening direction against the spring force of the compression coil spring 64. Pressure) × (the area of the donut area-shaped load pressure receiving surface 84) and the spring force of the compression coil spring 64 are the push-pull actuator.
When the pushing thrust exceeds 56, the pilot spool valve 54 returns to the direction in which the metering notch 69 is closed,
Since the meter-in side poppet valve 41 also operates in the direction to close the seat 49, the pump discharge pressure is reduced by the seat 49, and the supply pressure to the fluid pressure actuator 2 is reduced to a predetermined value.

Since the thrust of the push-pull actuator 56 is also controlled by the current value outputted from the controller 85, as shown in FIG. 9, each fluid pressure actuator is provided with a suitable pressure (force) modulation curve. be able to.

During the flow rate supply to the fluid pressure actuator 2, the central processing unit (CPU) of the controller 85
Corresponds to the push-pull actuator 56 based on the data in the memory previously input from the command current value.
The spring force of the compression coil spring 64 is known from the amount of displacement of the pilot spool valve 54 detected by the spool valve stroke detection sensor 81, and therefore, the load pressure receiving surface 84 in a donut area shape is known. Since the load pressure value acting on the pump discharge pressure sensor 87 can be calculated backward, the differential pressure across the seat 49 of the meter-in side poppet valve 41 is determined from the pump discharge pressure signal detected by the pump discharge pressure sensor 87.

The displacement amount of the meter-in side poppet valve 41 is detected by a poppet valve stroke detection sensor 75 for detecting the stroke of the meter-in side poppet valve 41, and the opening area of the poppet valve inlet can be determined from the displacement amount. The flow rate supplied to the pressure actuator 2 can be controlled, and as shown in FIG. 10, a suitable flow rate, that is, a velocity modulation curve can be provided for each fluid pressure actuator.

As described above, the pilot stage of each poppet valve 41 is a small pilot spool valve 54.
Since the leak is very small, the conventional meter-in valve and meter-out valve are provided with a drift reducing valve 5 (FIG. 11) for reducing a large amount of leak when the spool valve has a large diameter. No need.

Similarly, the load hold check valve 4
Is unnecessary, and there is an advantage that the valve housing 21 is compact and inexpensive.

Next, in FIG. 5, the poppet valve stroke detection sensor 75 for monitoring the stroke of the meter-in side poppet valve 41 is moved to the pilot spool valve 54 side from the embodiment shown in FIG. FIG. 6 shows an embodiment in which a poppet valve stroke detection sensor 75 is removed from the embodiment shown in FIG.

FIG. 7 shows a modification of the high voltage selecting means in each of the embodiments shown in FIGS. 1, 3, 5 and 6, and FIG. In each embodiment, the shuttle valve 42 is provided inside the meter-in side poppet valve 41 as the high pressure selecting means. However, as shown in FIG. It is not necessary.

That is, a circumferential groove 91 is provided at a position corresponding to the variable slot 47 on the inner peripheral surface of the poppet valve sliding hole of the valve housing 21, and a passage 13 on the pump discharge side is provided in the valve housing 21. A passage 92 communicating with the circumferential groove 91 is provided, a high-pressure selection check valve 42a as high-pressure selecting means is interposed in the passage 92, and a passage between the actuator-side passage 15 and the circumferential groove 91 is provided. A high-pressure selection check valve as high-pressure selection means in the passage 93.
42b is interposed, but the shuttle valve is functionally
Same as 42.

Then, the pressure in the passage 13 on the pump discharge side is guided to the high pressure selection check valve 42a via the passage 92, and the load pressure in the passage 15 on the fluid pressure actuator 2 side is guided to the high pressure selection check valve 42b via the passage 93. The high pressure side of these pressures is selected by the high pressure selection check valves 42a and 42b, and the circumferential groove is selected.
It may be introduced at 91.

FIG. 8 shows a modification of the load pressure receiving surface in each of the embodiments shown in FIGS. 3 and 6.
In each of the embodiments shown in FIGS. 3 and 6, a small-diameter step is formed at an intermediate portion of the first land portion 67 of the pilot spool valve 54 to form the load pressure receiving surface 84 having a donut area shape. In the embodiment shown in FIG. 8, a small-diameter cylindrical load pressure receiving rod 94 is formed integrally with a lower end portion of the pilot spool valve 54 via a locking portion 62 for receiving a spring. Load pressure receiving surface 95 with small diameter circular end face
Is formed.

In this case, the valve housing 21 is provided with a locking portion fitting hole 96 for fitting with the locking portion 62. A load pressure introducing chamber 98 is formed. The load pressure introducing chamber 98 is communicated by a passage 99 with a passage 73 through which the load pressure of the fluid pressure actuator 2 is led. The surface 95 always faces the load pressure introducing chamber 98.

Then, the load pressure of the fluid pressure actuator 2 is guided from the passage 73 to the load pressure introduction chamber 98 via the passage 99, and in the load pressure introduction chamber 98, the load pressure receiving surface 95 at the distal end of the load pressure receiving rod 94. The push-pull actuator 56
, The load pressure of the fluid pressure actuator 2 is fed back.

As described above, the meter-in side poppet valve 41 capable of bidirectional flow control has a load hold check valve function, so that the valve housing 21 can be made compact and regeneration control can be performed. In addition, the bridge circuit 3 for controlling the fluid pressure actuator is formed by combining the meter-in side poppet valve 41 and the meter-out side poppet valve 22 of the pilot flow rate amplification type, and the poppet valve is formed by a low leak type. In a bridge circuit composed of a large-diameter spool valve having the same diameter as that of 22, 41, a drift (leak) reduction valve required for the bridge circuit is eliminated, and the cost can be reduced.

Further, a load pressure calculating mechanism for calculating the load pressure from the current value and displacement of the push-pull actuator 56 of the pilot spool valve 54 having the load pressure receiving surface 84 formed by the load pressure feedback step is formed. For example, a plurality of fluid pressure actuators 2 can be individually controlled by suitable pressure modulation without requiring a pressure sensor required for detecting a load pressure. On the other hand, the velocity modulation suitable for the fluid pressure actuator 2 can be controlled by the load pressure calculation mechanism and the opening area monitoring means (poppet valve stroke detection sensor 75). Then, the other fluid pressure actuator stalls (stops) and the pump 1
Is high as determined by the main relief valve 9,
A suitable pressure control and pressure control of the fluid pressure actuator 2 can be individually achieved by the load pressure feedback mechanism (pressure reduction function) and the opening area monitoring mechanism by the load pressure receiving surface 84.

[0099]

According to the first aspect of the present invention, the load pressure on the fluid pressure actuator side is reduced by the high pressure selection means for selecting a higher pressure between the pump discharge pressure and the load pressure on the fluid pressure actuator side. When the pressure is higher than the pressure, the load pressure is guided to the pressure chamber and the poppet valve is controlled in the closing direction. A check valve can be dispensed with, and the valve housing can be made compact.

According to the second aspect of the present invention, the main flow rate is controlled by the poppet valve which is unlikely to leak, and the pilot flow rate from the pressure chamber of the poppet valve is controlled by the small-diameter pilot spool valve having a small leak amount. For example, the leak amount can be reduced as compared with the conventional case where the main flow rate is controlled by a large-diameter spool valve having the same diameter as the poppet valve.

According to the third aspect of the present invention, a meter-in valve and a meter-out valve using a pilot flow rate amplification type poppet valve are combined to form a bridge circuit for controlling a fluid pressure actuator, and these are controlled by a controller. Since the meter-in and meter-out valves are controlled, the directional control and flow rate of the fluid pressure actuator can be controlled, and the main flow rate is controlled by a conventional bridge circuit composed of, for example, a large-diameter spool valve having the same diameter as a poppet valve. In this case, the necessary drift reduction valve for preventing leakage can be eliminated, and the cost can be reduced.

According to the fourth aspect of the present invention, the working fluid can be regenerated from one meter-in valve to the other by opening both the meter-in valves.

According to the fifth aspect of the present invention, the high pressure selecting means selects a high pressure from the pressure of the passage on the pump side and the pressure of the passage on the side of the fluid pressure actuator, and guides the high pressure to the spring chamber.
Further, since the pilot flow discharged from the spring chamber to the low pressure side of the passage on the pump side and the passage on the fluid pressure actuator side is controlled by the pilot spool valve, bidirectional flow control can be performed by one poppet valve. When the pressure in the passage on the side of the fluid pressure actuator is high, the pressure is guided to the spring chamber through the high pressure selecting means. At this time, when the pilot spool valve is in the closed position, the internal pressure of the spring chamber causes the poppet valve to seat. , The load hold check valve function is obtained. Further, when the pressure in the passage on the pump side is high, the pressure is guided to the spring chamber through the high-pressure selecting means. At this time, when the pilot spool valve is displaced, the pilot chamber is moved from the spring chamber in accordance with the amount of displacement of the spool valve. A pilot flow discharged to the passage on the fluid pressure actuator side through the spool valve is generated, and the pressure in the spring chamber is reduced according to the pilot flow, so that a pilot flow amplification operation in which the opening of the poppet valve is controlled is obtained. In addition, when the pilot spool valve is in the neutral closed position, the load pressure acts on the spring chamber via the high-pressure selecting means. The valve can be abolished.

According to the present invention, the load pressure can be calculated from the current value and the displacement of the electromagnetic actuator that drives the pilot spool valve having the load pressure receiving surface for load pressure feedback. A plurality of hydraulic actuators can be individually controlled with suitable pressure modulation characteristics without the need for a pressure sensor.

According to the seventh aspect of the present invention, by controlling the differential pressure applied to the poppet valve and the opening area of the poppet valve, a plurality of hydraulic actuators can be individually controlled with suitable speed modulation characteristics. In particular, even if another fluid pressure actuator stalls (stops) and, for example, the pump reaches a high pressure determined by the main relief valve, the structure for feeding back the load pressure and the opening area monitoring means provide:
Suitable speed and pressure control of each hydraulic actuator can be achieved individually. This effect can be obtained even when a plurality of hydraulic actuators are operated independently or simultaneously.

[Brief description of the drawings]

FIG. 1 is a sectional view and a hydraulic circuit diagram showing an embodiment of a valve device and a hydraulic actuator control device according to the present invention.

2 shows a meter-in valve of the valve device shown in FIG. 1;
FIG. 3 is a hydraulic circuit diagram showing a bridge circuit formed in combination with a meter-out valve including a pilot flow amplification type poppet valve.

FIG. 3 is a cross-sectional view and a hydraulic circuit diagram showing another embodiment of the valve device and the fluid pressure actuator control device according to the present invention.

4 shows a meter-in valve of the valve device shown in FIG. 3,
FIG. 3 is a hydraulic circuit diagram showing a bridge circuit formed in combination with a meter-out valve including a pilot flow amplification type poppet valve.

5 is a cross-sectional view and a hydraulic circuit diagram showing a modification of the embodiment shown in FIG. 1, in which the poppet valve stroke detection sensor is moved to the pilot spool valve side.

FIG. 6 is a cross-sectional view and a hydraulic circuit diagram showing a modified example of the embodiment shown in FIG. 3, in which the poppet valve stroke detection sensor is removed.

FIG. 7 is a partial cross-sectional view showing a modification of the high-pressure selecting means in each of the embodiments shown in FIGS. 1, 3, 5, and 6;

FIG. 8 is a partial sectional view showing a modification of the load pressure receiving surface in each of the embodiments shown in FIGS. 3 and 6;

FIG. 9 is a characteristic diagram of a pressure (force) modulation curve showing a relationship between an operation amount of an operation lever and a control pressure of a fluid pressure actuator.

FIG. 10 is a characteristic diagram of a speed modulation curve showing a relationship between an operation amount of an operation lever and a speed of a fluid pressure actuator.

FIG. 11 is a hydraulic circuit diagram showing a conventional meter-in / meter-out separated control circuit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pump 2 Fluid pressure actuator 3 Bridge circuit A1IMV, A2IMV Meter-in valve A3IMV, A4IMV meter-out valve 13 Pump side passage 15 Fluid pressure actuator side passage 41 Meter-in side poppet valve as poppet valve 42 Shuttle valve as high pressure selection means 42a, 42b High pressure selection check valve as high pressure selection means 49 Seat part 51 Spring chamber as pressure chamber 52 Compression coil spring as spring 54 Pilot spool valve 56 Push-pull actuator as electromagnetic actuator 64 Compression coil spring as pilot spring 75 Opening area Poppet valve stroke detection sensor as monitoring means 81 Spool valve stroke detection sensor 84 Ring-shaped step-type load pressure receiving surface 95 Load-pressure receiving surface of small-diameter circular end face 85 Controller 87 Pump discharge pressure sensor

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazunori Yoshino 4-10-1, Yoga, Setagaya-ku, Tokyo Inside New Caterpillar Mitsubishi Corporation (72) Inventor Shoji Tozawa 4-1-1 Yoga, Setagaya-ku, Tokyo New Caterpillar Mitsubishi F-term (reference) 3H052 AA01 BA25 CA04 CA13 EA16 3H089 AA22 AA23 AA60 AA74 BB01 BB19 DB03 DB14 DB73 DB78 DB79 EE07 EE31 GG02 JJ01 3H106 DA05 DA23 DA35 DB02 DB12 DB23 DB32 DC09 DD03

Claims (7)

[Claims] 1. A poppet valve for controlling a working fluid supplied from a pump to a hydraulic actuator, a pressure chamber for applying pressure in a direction to close the poppet valve, a pump discharge pressure and a load pressure on a hydraulic actuator side. And a high-pressure selecting means for selecting a higher pressure and guiding the selected pressure to the pressure chamber. 2. A poppet valve for controlling a main flow rate, a pressure chamber for applying pressure in a direction to close the poppet valve, a pilot spool valve smaller in diameter than a poppet valve for controlling a pilot flow rate discharged from the pressure chamber, and A valve device comprising: 3. A pump, comprising: a pump; a hydraulic actuator that is operated by a working fluid discharged from the pump; and a pump-side pump provided with the valve device according to claim 2, provided between the pump and the hydraulic actuator. A controller for a fluid pressure actuator, comprising: a bridge circuit formed by two meter-in valves and two meter-out valves on a fluid pressure actuator side; and a controller for controlling the meter-in valve and the meter-out valve. . 4. The control apparatus according to claim 3, wherein the controller controls the two meter-in valves to open together. 5. A meter-in valve comprising: a seat portion provided between a pump and a fluid pressure actuator; a bi-directional flow controllable poppet valve provided to be able to contact and separate from the seat portion; A spring chamber located on the opposite side to the seat portion, a spring built in the spring chamber to press the poppet valve against the seat portion, and a high pressure due to the pressure of the pump side passage and the pressure of the fluid pressure actuator side passage. And a pilot spool valve having a smaller diameter than a poppet valve for controlling a pilot flow rate discharged from the spring chamber to the low pressure side of the passage on the pump side and the passage on the fluid pressure actuator side from the spring chamber. 5. The control device for a fluid pressure actuator according to claim 3, wherein the control device is provided. 6. An electromagnetic actuator for pushing a pilot spool valve in an axial direction, a pilot spring for urging the pilot spool valve to a neutral position with respect to the electromagnetic actuator, and a spool valve stroke detection sensor for detecting a displacement of the pilot spool valve. And a load pressure receiving surface provided on the pilot spool valve for receiving a load pressure on the fluid pressure actuator side. The controller determines the thrust from a current value supplied to the electromagnetic actuator, and the spool valve stroke detection sensor The load on the load pressure receiving surface of the pilot spool valve is calculated by calculating the spring force from the detected axial displacement of the pilot spool valve and dividing the difference between the thrust of the electromagnetic actuator and the spring force by the area of the load pressure receiving surface. Calculates the pressure and the fluid pressure actuator for the operation amount Control device for a fluid pressure actuator of the pressure modulation curve representing the variation of the supply pressure according to claim 5, wherein the controlling in response to the fluid pressure actuator. 7. A pump discharge pressure sensor for detecting a pump discharge pressure of a working fluid discharged from a pump, and an opening area monitoring means for monitoring an opening area of the poppet valve based on a displacement amount of the poppet valve, wherein the controller comprises: A differential pressure applied to the poppet valve is calculated from a pump discharge pressure applied to the poppet valve detected by the pump discharge pressure sensor and a load pressure applied to the poppet valve obtained by an operation related to a load pressure receiving surface of the pilot spool valve. The flow rate of the working fluid supplied to the hydraulic actuator is calculated based on the differential pressure and the opening area of the poppet valve detected by the opening area monitoring means, and the speed modulation representing the change in the speed of the hydraulic actuator with respect to the operation amount is calculated. 7. The hydraulic actuator according to claim 6, wherein the curve is controlled according to a hydraulic actuator. Over other control devices.