JPH03521B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Application This invention provides a method for controlling and controlling a control stroke and a working fluid flow rate.
This is an electrohydraulic proportional valve that can be adjusted, and a proportional solenoid plunger that operates in proportion to an input electrical signal opens and closes an adjustment spool with a seat valve, providing feedback on the opening of the control valve on the controlled side. The pin transmits information to the seat valve via the adjustment spring, and the control valve is configured to open and close in proportion to the electric signal by causing the working fluid to flow in and out at a constant rate, and is not affected by the working fluid pressure. The present invention relates to an electrohydraulic proportional valve that can control and adjust stroke control and working fluid flow rate with good responsiveness in proportion to input electrical signals, and does not require a hydraulic adjustment circuit for mitigating hydraulic vibration.

BACKGROUND ART In general, it is well known that servo valves and control valves that can adjust the stroke are useful for adjusting the stroke of the control spool, but are not suitable for adjusting the stroke of the seated valve that they control. There is.

In particular, in order to quickly and flexibly control linear or rotary hydraulic fluid motors, it is necessary to arrange large seat valves in multiple stages and combine them with the valve unit that controls them. This circuit provides stroke adjustment or flow rate adjustment regardless of the load, allowing control and regulation of the working fluid.

In the past, such control and regulation generally required the use of complex and expensive circuitry.

As a conventional electromagnetic proportional flow control valve, a pilot system for a seat valve in which a known multi-directional control valve is used as a pilot valve is proposed in the West German Publication Specification (DE-OS 2835771).

This means that the opening stroke of the seat valve piston is controlled in parallel by the stroke of the tappet of the pilot cylinder disposed in between, through the seat valve in the seat valve piston, and the multi-directional adjustment of the pilot cylinder piston and the pilot switching valve It is determined by a control spring arranged between the valve and the proportional solenoid in response to the electrical signal of the proportional solenoid.

Furthermore, Japanese Patent Application Laid-open No. 53-32280 discloses an electromagnetic pressure reducing valve section in which a pilot spool is coaxially arranged with the main spool via a main spring on both sides of a flow direction control valve section whose opening degree is changed by the main spool. established,
Further, a feedback spring is arranged coaxially and in series with the main spring on each opposing end surface of the main spool and the pilot spool, and the pressure of one electromagnetic pressure reducing valve is fed back to the electromagnetic pressure reducing valve via the feedback spring on the other side, A configuration is shown that provides position control of the main spool proportional to the electrical input to the solenoid valve.

Problems to be Solved by the Invention The former electromagnetic proportional flow control valve is an expensive three-stage hydraulic control device that operates from a multi-directional control valve with a proportional solenoid to a seat valve through a pilot cylinder to control the required pressurized medium flow. The opening stroke is controlled.

In this case, multi-way control valves with a closed central position require a large adjustment stroke, which on the one hand hinders the rapid conversion of electrical signals into hydraulic signals, and on the other hand has the problem of causing vibrations.

In the latter configuration having the feedback spring, the pilot chamber is supplied with pilot hydraulic pressure reduced by the pressure control section. For this reason, even if the original pressure is 100 atm, the pilot pressure is around 10 to 20 atm, which causes problems with slow response.Also, since the pressure is reduced in the pilot spool, dirt in the oil may cause the spool to malfunction. There were problems with reliability, such as the possibility that the system might stop working.

This invention has a simple configuration that does not require a hydraulic adjustment circuit for mitigating hydraulic vibrations, and controls stroke control and the flow rate of the working fluid with high responsiveness in proportion to the input electrical signal without being affected by the working fluid pressure. - Aims to provide an electrohydraulic proportional valve that can be adjusted.

Means for Solving the Problems The present invention will be described using the reference numerals shown in FIG. A plunger 2 of a proportional solenoid 1 is attached to one end of a freely inserted adjustment spool 3.
The adjustment spring 1 in the adjustment spring chamber 15 formed by the inner inner end of the spool housing 4 and the inner inner end of the center hole of the end cover 21a is in contact with the seat valve 9 at the other end.
0 comes into contact and a reaction force is applied in the direction of the plunger 2, and the control spring 18 in the control spring chamber 23 formed by the innermost end of the end cover 21a and the valve hole of the body 21
A control valve 19 of a seat valve piston that closes a port is disposed coaxially with the proportional solenoid 1 and the adjustment spool 3, and a feedback pin (hereinafter referred to as FB pin) 17 that abuts the inner end of the control valve 19 is connected to the adjustment spool 3. The plunger 2 is connected to the adjustment spool 3 via the spring 10.
The adjustment spring chamber 15 and the control spring chamber 23 communicate with each other through a plurality of holes 14 provided in the peripheral wall of the adjustment spring chamber 15, and the end surface of the adjustment spool 3 on the plunger 2 side A front chamber 12 is provided between the inner end surface of the proportional solenoid 1 and the outer end surface of the spool housing 4 to balance the pressure of the regulating spool 3 by pressurizing the spool. The control valve 19 reaches the seat part of the seat valve 9 of the adjustment spool 3, and when the seat valve 9 is opened, the passage 7 communicates with the adjustment spring chamber 15 through a plurality of holes 8 provided in the wall of the spool housing 4. The valve 9 is opened by the protrusion of the plunger 2 of the proportional solenoid 1 and the control valve 19 is opened. FB
The pin 17 is connected to the adjustment spring 1 according to the opening degree of the control valve 19.
This is an electrohydraulic proportional valve characterized in that it has a stroke in which the seat valve 9 is closed by applying a pressure of 0, and the control valve 19 is opened and closed in response to electrical input to the proportional solenoid 1.

Further, the present invention has a structure similar to the above structure, but further has a structure in which the control working fluid flows out from the control spring chamber 31 through the seat valve 9 to the Y port, and an intermediate portion is provided between the FB pin 27 and the adjustment spring 10. A control spring chamber 31 with a pin 29 disposed within the compensating cylinder 24 and receiving actuating fluid pressure from the X port.
and an annular chamber 1 filled with pressureless working fluid.
6. As a stroke transmission member between the control spring chamber 15 and the control spring chamber 15, it is configured so as not to receive axial force, and transmits the control spring 10 according to the opening stroke of the control valve 19 via the FB pin 27 and the intermediate pin 29. It is characterized by compression.

That is, the present invention will be explained using the reference numerals in FIG. 3. An end cover 2 fixed to an end surface of a body 21
An adjustment spool 3 is slidably inserted into a spool housing 4 which is inserted and fixed into the center hole of 1a.
The plunger 2 of the proportional solenoid 1 is in contact with one end of the spring, and the other end, on the seat valve 9 side, is in the adjustment spring chamber 15 formed by the inner inner end of the spool housing 4 and the inner end of the center hole of the end cover 21a. adjustment spring 10
contact, and a reaction force is applied in the two directions of the plunger, causing the inner inner end of the end cover 21a and the body 21
A control valve 19 of a seat valve piston, which closes a port by a control spring 18 in a control spring chamber 31 formed with a valve hole of FB pin 2 that touches
A compensating piston 25 is housed in a compensating cylinder 24 that holds the compensating piston 7, and is engaged with the adjusting spring 10 via an intermediate pin 29 that slides inside the cylinder 24. Applying reaction forces in two directions, the internal pressure of the control spring chamber 31 acts on one end surface of the piston 25, and the internal pressure of the adjustment spring chamber 15 acts on the other end surface through the through hole of the intermediate pin 29, The adjustment spring chamber 15 and the control spring chamber 31 are independent, and the FB pin 27 does not compress the adjustment spring 10 with fluid pressure when the control working fluid is supplied from the port X, and the plunger 2 of the adjustment spool 3 A front chamber 12 is provided between the inner end surface of the proportional solenoid 1 and the outer end surface of the spool housing 4 for pressure balancing the regulating spool 3 by pressurizing the side end surfaces, and has a passage to the control spring chamber 31 and a passage from said passage. The inlet port X of the working fluid for control of the control valve is connected to the passage 7 which branches out and reaches the seat valve 9 of the regulation spool 3 and communicates with the regulation spring chamber 15 when the seat valve 9 is opened. An annular chamber 1 communicating with a plurality of holes 14
6 and the front chamber 12 are communicated through a passage, for example, a passage 13, and the annular chamber 16 is connected to the working fluid outlet port Y.
When the plunger 2 of the proportional solenoid 1 protrudes, the seat valve 9 is opened, and the control valve 19 is further opened.
The FB pin 27 has a stroke in which the control spring 10 is compressed via the intermediate pin 29 according to the opening degree of the control valve 19 to close the seat valve 9, and the control valve 19 is compressed in accordance with the electrical input to the proportional solenoid 1. This is an electrohydraulic proportional valve that is characterized by opening and closing.

Function The electrohydraulic proportional valve of the present invention controls the control valve consisting of a seat valve piston or spool, which closes the operating ports A and B by the pressing force of the control spring, by the linear movement of the plunger of the proportional solenoid. A control valve and a proportional solenoid are arranged in series, and an adjustment spool with a seat valve between them and an FB pin that is pressed by an adjustment spring and comes into contact with the end face of the control valve are arranged in series, and one end of the adjustment spool is connected to the tip of the plunger. , and the other end is pressed by an adjustment spring to close the seat part for adjusting the inflow and outflow of the control working fluid, and the same working fluid pressure is applied to both ends of the adjustment spool. On the other hand, the adjustment spring that acts and presses the seat valve is
The FB pin is brought into contact with the end face of the control valve, and when the operating port is opened, the force is transmitted to the seat valve via the adjustment spring.

That is, the electrohydraulic proportional valve according to the present invention:
A proportional solenoid serves as a target value unit in which the electric signal is converted and is transmitted from the plunger as an upward force to the regulating spool with the seat valve, and in the opening stroke of the control valve, it acts on the regulating spring via the FB pin to control the seat valve. an adjustment spool with a
It consists of a control valve as a measured value unit that transmits downward against the force of the plunger acting oppositely, and a seat valve on the adjustment spool calibrates the target value and the measured value in proportion to the electric signal. The feature is that this is done by opening and closing.

This invention controls and adjusts the stroke of seat valves, spools, and other devices by mechanically converting the movement of the seat valves, etc., arranged in series and coaxially, that is, the stroke, into force, and the force generated by the plunger of a proportional solenoid. The feedback force of the FB pin, which is linearly opposed to the It adjusts the pressure.

In the electrohydraulic proportional valve of the present invention, with the above-described configuration, the adjustment spool equipped with a long cylindrical vibration-damping contact surface, together with the seat valve as the adjustment valve, contacts the working fluid between them during operation. Therefore, vibration can be damped, and a hydraulic adjustment circuit for mitigating hydraulic vibration is not required. In addition, the control spool with a seat valve has the same working fluid pressure applied to both ends, and only the input from the proportional solenoid and the feedback force of the FB pin act in the axial direction, causing the control valve to open. When adjusting the temperature, the target value/actual value can be finely adjusted via the FB pin, and it has the advantage of excellent conversion from electrical signals to hydraulic signals, and excellent responsiveness.

Disclosure of the Invention Based on the Drawings The configuration of the electrohydraulic proportional valve according to the present invention will be described in detail below based on the drawings.

Configuration 1 As shown in Fig. 1, an end cover 21a containing a proportional solenoid 1, an adjustment spool 3, and an adjustment spring 10, and a body 21 into which a control valve 19 is inserted and each port is provided are arranged coaxially. .

The adjustment spool 3 is fitted into a spool housing 4 inserted into the central hole of the end cover 21a, and the housing 4 is adjusted within the end cover 21a by an elastic plug 5 and adjustment screw 6 that abut at right angles. It has a screw-tight structure for positioning, and is used for structural position adjustment.

The lower end of the adjustment spool 3 is connected to the proportional solenoid 1.
The plunger 2 protrudes into the front chamber 12 located between the front chamber 12 and the plunger 2.

Further, the upper end of the adjustment spool 3 is constituted by a seat valve 9, the upper end of the spool housing 4 is a seat, a small chamber is formed in the lower part thereof, a hole 8 through which working fluid flows is opened, and the valve is connected to a passage 7.

An adjustment spring chamber 15 is formed in the upper end of the end cover 21a, and an adjustment spring 10 is enclosed in the chamber 15, which contacts the top of the seat valve 9 and applies force to the adjustment spool 3 in the direction of the plunger 2.

Further, an FB pin 17 is inserted through the upper end of the adjustment spring chamber 15, and the lower end of the FB pin 17 is in contact with the adjustment spring 10 via a washer 11, so that a constant length always projects out of the adjustment spring chamber 15.

Furthermore, the adjustment spring chamber 15 is provided with a hole 14 through which the working fluid flows and communicates with the control spring chamber.

Here, a seat valve piston is used for the control valve 19 to be controlled, and is fitted into a hole on the body 21 side and sealed by an end cover 21a to form a control spring chamber 23 containing a control spring 18, and an adjustment spool. It is arranged coaxially with 3.

Further, the control spring 18 is adjusted so that the control valve 19 always closes the A and B ports, and the P and T ports are connected to the annular chamber 20.

In addition, P is pressure port, T is tank port, A and B are working ports, X is the control fluid inlet port, Y is the control fluid outlet port.

The FB pin 17 is protruded by a certain length by the adjustment spring 10 and abuts on the spring chamber side of the control valve 19 that closes the A and B ports.

Further, a passage 13 is connected to the control spring chamber 23 and the front chamber 12.

Next, the functions of each part of the electrohydraulic proportional valve of the present invention having the above-described configuration will be explained.

First, in a state where there is no input electrical signal, that is, in a stationary state, the seat valve 9 and the control valve 19 are in close contact with each seat by the adjustment spring 10 and the control spring 18, respectively, and there is no movement of the working fluid.

That is, a control working fluid having the same pressure as the working fluid in the P port flows from the X port through the throttle 22 and from the passage 13 into the front chamber 12 and the control spring chamber 23, and also flows into the adjustment spring chamber 15. Fluid is flowing.

Therefore, the adjustment spool 3 is balanced by the same pressure working fluid acting on the front chamber 12 and the adjustment spring chamber 15, so that the seat valve 9 is in the closed state, and the control valve 19 is in the closed state. A working fluid of the same pressure acts on both ports, and this control valve 19 can be held in a closed state against the pressure of the working fluid acting on the A or B port.

Next, an electric signal is input to the proportional solenoid 1, and when the protrusion force of the plunger 2 becomes larger than the force of the adjustment spring 10 opposing it, and the adjustment spool 3 is moved upward, the seat valve 9 opens and the adjustment spring chamber The working fluid in 15 flows out under its own pressure and begins to flow out through hole 8 and passage 7 to the Y port.

For example, by providing a throttle 22 in the passage 13 from the Therefore, the setting is made so that the amount of working fluid flowing out to the Y port is increased.

Therefore, the pressure of the working fluid with the closing force of the control valve 19 in the control spring chamber 23 is lower than the working fluid pressure for actuation acting in the annular chamber 20 and the A or B port, so that the control valve 19 is closed. It will be released.

At this time, since the FB pin 17 is in contact with the control valve 19, the FB pin 17 compresses the adjustment spring 10 according to its opening, and the force of this adjustment spring 10 is greater than the protrusion force of the plunger 2 opposing it. The control valve 19 is opened until the value becomes large.

That is, the FB pin 17 transmits the opening degree of the control valve 19 to the adjustment spring 10, which is compressed and fed back. ,
When the force becomes larger than the protrusion force of the plunger 2, it is closed, and the working fluid in the control spring chamber 23 is stopped from continuously flowing out from the passage 7 to the Y port.

Therefore, by closing the seat valve 9, the control spring chamber 2
3 is prevented from reducing the pressure in the control valve 19.
The process of opening operating ports A and B also stops.

Through the above series of steps, the electrohydraulic proportional valve of the present invention has the plunger 2 of the proportional solenoid 1, which operates in proportion to the input electric signal, opening and closing the regulating spool 3 having the seat valve 9 accordingly. The FB pin 17 transmits the opening degree of the control valve 19 to the seat valve 9 via the adjustment spring 10, so that the working fluid flows in and out at a constant rate, and the control valve 19 is opened and closed at a magnitude proportional to the electric signal. It is becoming possible.

The present invention has been described above in detail based on FIG. 1, which shows the configuration in which the seat valve-shaped control valve 19 is controlled proportionally.
Its structure is not limited to what is shown in the diagram,
Any electrohydraulic proportional valve may be used as long as it has the function of the series of strokes described above. Further, not only when the working fluid is pressure oil, but also when water is used instead of pressure oil, the same action and function are obtained.

For example, if the adjustment spool 3 has a hole in its center in the axial direction so that the adjustment spring chamber 15 and the front chamber 12 communicate with each other so that the pressure is balanced, the passage 13 from the X port to the front chamber 12 becomes unnecessary. .

It is also preferable to arrange an intermediate member of elastic material between the plunger 2 and the adjusting spool 3.

Alternatively, the FB pin 17 may be composed of two members in series, one of which can be adjusted in length in the axial direction, for example, one may be screwed onto the other. Also, the FB pin 17 can be omitted and the adjustment spring 1
0 may be configured to directly contact the control valve 19.

Further, a plurality of passage restrictors 22 may be arranged coaxially, and may be provided not only in the main body passage but also in a control valve, a regulating spool, etc.

Configuration 2 Next, regarding the direction of the control working fluid flowing in and out of the seat valve 9, as shown in Fig. 2, in the same configuration as the electrohydraulic proportional valve described above, the X port on the inflow side of the working fluid is The passage 7 and the hole 8 lead to the seat valve 9, and the Y port on the outflow side is connected to the adjustment spring chamber 1.
5, the hole 14, the control spring chamber 23, and a configuration in which the control spring chamber 23 is placed on the path side leading to the passage 13 can be used. In this case, although the control working fluid flows in the opposite direction to the case shown in FIG. 1 described above, the operating stroke and function of the electrohydraulic proportional valve are exactly the same.

That is, by opening and closing the seat valve 9 of the adjustment spool 3, the control valve 19 opens and closes in a magnitude proportional to the electric signal input to the proportional solenoid 1.

Configuration 3 FIG. 3 shows a configuration in which the control working fluid flows out from the control spring chamber 31 to the Y port via the seat valve 9, and an intermediate pin 29 is provided between the FB pin 27 and the adjustment spring 10. A configuration disposed within the cylinder 24 is shown. The configuration is detailed below.

From the X port through the aperture 22, the control spring chamber 31
The passage 7 communicates with the hole 8 and the seat valve 9, the adjustment spring chamber 15 communicates with the Y port through the hole 14 and the annular chamber 16, and the annular chamber 16 communicates with the front chamber 12 through the passage 13. ing.

The intermediate pin 29 is then inserted into the compensation cylinder 24, which is mounted between the FB pin 27 and the adjustment spring 10 and communicates with the control spring chamber 31, so that the FB
A compensating piston 25 is connected to the lower end of the pin 27, and is attached to the body by a safety catch 26 to slide inside the cylinder 24.

Moreover, the intermediate pin 29 is bored in the center and provided with a hole passage 30, so that the working fluid of the adjustment spring chamber 15 flows into the annular chamber 28 above the compensation piston 25, and the control spring chamber 31 is formed below the piston 25. of working fluid is flowing in.

Therefore, the intermediate pin 29 serves as a stroke transmission member between the control spring chamber 31 receiving the working fluid pressure from the X port and the annular chamber 16 and the adjusting spring chamber 15 filled with pressureless working fluid. , a working fluid regulating unit configured to be free from axial forces.

The electrohydraulic proportional valve having the above structure also performs the same operation as the structure shown in FIG. 1 described above.

That is, when it is at rest, the pressure in the front chamber 12 and the adjustment spring chamber 15 is balanced, and the seat valve 9 is closed by the adjustment spring 10. On the other hand, the working fluid from the X port flows into the control spring chamber 31, and The control valve 19 is closed by the control spring 18 against the pressure of the working fluid acting on the T port and the A or B port.

Next, when the plunger 2 pushes the adjustment spool 3 in proportion to the electric signal input to the proportional solenoid 1 and the seat valve 9 opens, the working fluid in the control spring chamber 31 passes through the passage 7 and the hole 8 to the adjustment spring chamber 15. It then flows out from the annular chamber 16 to the Y port.

By providing the above-mentioned throttle 22, the amount of outflow to the Y port becomes larger than the outflow amount from the X port, and the pressure in the control spring chamber 31 decreases.

Therefore, the control valve 19 opens in response to the pressure drop in the control spring chamber 31. As the control valve 19 opens, the FB pin 27 begins to compress the adjustment spring 10 via the intermediate pin 29 and washer 11, and when the spring force becomes greater than the protruding force of the plunger 2, the seat valve 9 is closed.

Therefore, the flow of the control working fluid to the Y port is stopped, pressure reduction in the control spring chamber 31 is prevented, and the opening stroke of the control valve 19 is stopped.

Through the above series of steps, the seat valve 9, which is proportionally opened and closed according to the electric signal input to the proportional solenoid 1, is set to the proportional solenoid 1 as the target value.
The opening stroke of the control valve 19 proportional to the input of the proportional solenoid 1 can be obtained by comparing and controlling the force of the control valve 19 with the force of the control valve 19 as an actual value.

By disposing the compensating cylinder 24 and applying working fluid pressure to the upper and lower ends of the compensating piston 25 disposed around the intermediate pin 29, it acts as a stroke transmitting member between the adjusting spring chamber 15 and receives the axial force. Moreover, in the configurations of various embodiments to be described later, the pressure of the FB pin 27 can be compensated by applying the working fluid pressure of each working port.

The compensating cylinder 24 can also consist of a sleeve and a disc, for example in such a way that these parts are held against each other in a non-compressive state relative to the adjusting spring 10.

Furthermore, although the compensating piston 25 is made into a separate member, it can be made into one member integrally with the safety catch 26 and the intermediate pin 29 or the FB pin 27.

Examples Application examples of the electrohydraulic proportional valve according to the present invention will be described below.

Embodiment 1 Although FIGS. 1 to 3 show the case where the electrohydraulic proportional valve of the present invention opens and closes a seat valve-like control valve 19, the same applies even if the controlled object is a control spool. It is possible to have the function of

For example, as shown in FIG. 4, electrohydraulic proportional valves according to the invention can be operated at both ends of the control spool 33 as a directional valve.

To explain in detail, the pair of electrohydraulic proportional valves disposed at both ends of the control spool 33 have the same configuration as that described above based on FIG.
3 is brought into contact with the control spring 18 via the spring support portion 32, which is a perforated disc, and is positioned in a neutral position.

That is, when the control spool 33 is at rest, the A and B ports are closed, and the working fluid from the P port passes through the passage 36, the throttle 35, and the passage 34, and then enters the control spring chamber 2.
Similarly, at the other end of the control spool 33, it flows into the control spring chamber 23 through the passage 36, the throttle 37, and the passage 38, so that the pressure at both ends of the control spool 33 is balanced, and the pressure at both ends of the control spool 33 is balanced. 3 is also a seat valve 9
Department is closed.

Here, the adjustment spool 3 is pushed in response to the signal input to the lower proportional solenoid 1, and the seat valve 9
By opening the opening, the amount of working fluid flowing out to the T port becomes larger than the amount flowing in from the P port through the throttle 35, the pressure inside the control spring chamber 23 decreases, and the control spool 33 moves downward in the drawing. Then, the working fluid flows from the pressure port P port to the working port A port.

The FB pin 17 then moves by measuring the amount of movement of the control spool 33 and pushes back the adjustment spool 3 so that the force pushing the adjustment spool 3 from the proportional solenoid 1 is greater than the force pushing the adjustment spool 3 and closes the seat valve 9.

Therefore, the stroke of the control spool 33 can be controlled in accordance with the electrical signal input to the proportional solenoid 1.

Embodiment 2 The electrohydraulic proportional valve shown in FIG. 5 is used, for example, to control the direction of movement of a linear or rotary working fluid motor by adjusting the flow rate of working fluid proportional to the magnitude of an input electric signal. Are suitable.

That is, the electrohydraulic proportional valve shown in FIG. 5 is basically the electrohydraulic proportional valve of the present invention having the compensation cylinder 24 and intermediate pin 29 shown in FIG. In addition to the control valve 19 provided in the circuit for the working fluid flowing out from the motor, a second control valve is provided in the circuit for the working fluid flowing from the P port to the A port into the working fluid motor.
A control valve 43 is provided, and a control spring chamber 31 and a seat valve 9 are provided.
The working fluid flowing into the second control valve 43 is introduced through a constriction 44 of a hole penetrating the second control valve 43 and a second control spring chamber 48 . Its operation is as follows.

First, in a stationary state, the working fluid of the P port is
The flow flows from the annular chamber 45 of the second control valve 43 into the second control spring chamber 48 through a throttle 44 installed in a hole penetrating the valve 43, and the working fluid pressure in the annular chamber 45 and the A port are balanced. , the spring 5 of the spring chamber 48
5 force closes the second control valve 43.

Furthermore, the working fluid of the P port is supplied to the spring chamber 4.
From 8, the end cover 57 attached to the body 21
It flows into the regulating spring chamber 31 through the passage 46 provided in the control valve 19 and closes the control valve 19 together with the spring force of the control spring 18 against the working fluid in the annular chamber 20 of the control valve 19 and the B port. There is.

Further, the working fluid reaches the seat valve 9 from the hole 8 through the passage 7 branched from the passage 46, and as mentioned above, the working fluid to the seat valve 9 has to push the adjustment spool 3 to open the seat valve. If the flow cannot flow to the T port, the seat valve 9 is closed by the force of the adjustment spring 10.
is closed.

Therefore, the connected working fluid motor is held fixed because no working fluid flows in or out.

Then, to control the connected working fluid motor in a predetermined direction of movement, the regulating spool 3 is controlled by inputting the necessary electrical signals to the proportional solenoid 1.
The amount of working fluid flowing out to the T port through the amplifying seat valve spring chamber 15, annular chamber 16, and passage 47 flows from the P port through the second control spring chamber 48 to the seat valve 9. When the amount of working fluid reaches the valve 9, that is, by providing the throttle 44 to limit the inflow, the working fluid pressure in the second control spring chamber 48 and the control spring chamber 31 decreases, and the pressure of the working fluid in the P port decreases. The pressure within the annular chamber 45 becomes relatively high and the second control valve 43 opens.

Subsequently, as the pressure within the control spring chamber 31 decreases, the control valve 19 opens in proportion to the electric signal input to the proportional solenoid 1, as described above.

Next, the working fluid flowing from the P port to the A port operates the connected working fluid motor, and the working fluid from the motor flows from the B port to the control valve 1.
9 to the T port, and the control valve 19 is closed when the FB pin 27 in contact therewith presses the adjustment spring 10 via the intermediate pin 29 to adjust the flow rate in proportion to the electric signal input.

Therefore, the operating speed of the working fluid motor is controlled in proportion to the magnitude of the electrical signal input. Of course, in order to operate the working fluid motor in the opposite direction to the above-mentioned operating direction, it goes without saying that one more system of this electrohydraulic proportional valve is required.

Embodiment 3 In addition to the electrohydraulic proportional valve of Embodiment 2, an amplification seat valve 53 for handling a large amount of working fluid is added to the control valve 1.
The electrohydraulic proportional valve incorporated into the circuit No. 9 will be explained based on FIG.

That is, this electrohydraulic proportional valve basically has the same configuration as that shown in FIG.
between the control spring chamber 31 via the control spring chamber 31 and the hydraulic fluid circuit which also passes through the channel 7 to the seat valve 9 for the main control adjustment, and which receives the hydraulic fluid into the second control spring chamber 48 and reaches the channel 7. It is characterized in that an amplification seat valve 53 is provided for preliminary control.

The amplifying seat valve 53 is slidably fitted into a hole provided in a cover 50 attached to the body 21 and is configured to abut against a valve seat 56 by a spring 55 in the hole. When attached to the end cover 57, the support portion of the passage 46 is disposed around the support portion.

Further, a hole that penetrates the amplification seat valve 53 and houses the throttle 52 is connected to the amplification seat valve spring 5 from the passage 46.
4. It communicates with passage 7, and the aperture 4 is connected to the P port.
The working fluid flowing into the second control spring chamber 48 via the amplifying seat valve 53 is configured to reach the seat valve 9 via the amplifying seat valve 53. Furthermore, the amplification seat valve 53
The annular chamber 51 communicates with the T port via a passage 49.

Next, to explain the function of this electrohydraulic proportional valve, firstly, when it is at rest, the amplifying seat valve 53 resists the pressure in the passage 46 and increases the pressure in the spring chamber 54 and the spring 5.
It will be closed with 5 forces.

Further, as described above, the working fluid to the seat valve 9 pushes the adjustment spool 3 and cannot flow out to the T port unless the seat valve 9 is opened.
The second control valve 43 and the amplification seat valve 53 are all closed. That is, the connected motor is held fixed at the current position without the flow of working fluid.

Next, when a predetermined electric signal is input to the proportional solenoid 1, the seat valve 9 of the adjustment spool 3 opens in proportion to the input, and the working fluid in the amplification seat valve spring chamber 54 flows out through the passage 7 to the T port. The working fluid flowing in from the spring chamber 54 of the amplifying seat valve 53 is smaller than the above-mentioned outflow amount because it flows from the second control spring chamber 48 through the throttle 52, and as a result, the pressure inside the spring 54 decreases and the amplifying seat valve Valve 53 opens.

When the amplification seat valve 53 opens, the working fluid in the second control spring chamber 48 flows out from the annular chamber 51 through the passage 49 to the T port, and then from the P port to the spring chamber 48 through the throttle 44. Although the working fluid flows in, a large amount flows out to the T port, and the pressure inside the second control spring chamber 48 decreases, causing the second control valve 43 to open.

Furthermore, by opening the amplification seat valve 53, the working fluid in the control spring chamber 31 is transferred to the passage 46 and the annular chamber 5.
1. It flows out to the T port via the passage 49, and as mentioned above, the pressure inside the spring chamber 31 decreases, and the control valve 1
9 opens.

At this time, the FB pin 27 compresses the adjustment spring 10 according to the opening degree of the control valve 19 to counteract the force of the plunger 2 and close the seat valve 9 of the adjustment spool 3.

That is, the outflow of the working fluid from the amplification seat valve 53 system is prevented and the same valve 53 is closed, and subsequently the outflow from the control valve 19 system is also prevented and the second control valve 43 and the control valve 19 are closed. . Through the above steps, the control valve 19 is maintained at a small opening in proportion to the electric signal.

Therefore, when the second control valve 43 is opened, the working fluid enters the A port from the P port, reaches the working fluid motor connected to this port, and is transferred from the motor to the B port.
The flow rate from B to T port is controlled by a control valve 19 that opens in proportion to the electric signal input to the proportional solenoid 1.
The operating speed of the actuating fluid motor is controlled in proportion to the magnitude of the input signal.

Further, it is natural that another system of the above-mentioned electrohydraulic proportional valve is required to operate the working fluid motor in the opposite direction to the above-mentioned operating direction.

Embodiment 4 In an application example of the electrohydraulic proportional valve of the present invention to be described next, a seat valve-shaped control valve 19 is installed in the passage communicating from the B port to the T port of the working fluid motor. It is equivalent to a hydraulic proportional valve, and furthermore, an auxiliary seat valve 39 is provided in the passage from the B port to the T port, and the auxiliary valve spring chamber 40 is arranged in series with the second control spring 48 to control the flow rate of the working fluid in the control valve 19. An electrohydraulic proportional valve configured to perform measurements without consuming working fluid at rest and to control a working fluid motor.

That is, the electrohydraulic proportional valve shown in FIG. 7 is basically the electrohydraulic proportional valve shown in FIG.
The control spring chamber 31 is sealed except that it communicates with the annular chamber 20 of the control valve 19 through a through hole having a throttle 44 provided in the control valve 19 itself, and further, the annular chamber 20 communicates with the B1 passage, An auxiliary seat valve 39 is formed between this and the T port, and a control valve 1 is connected between the B port and the T port via the B1 passage.
The difference is that 9 and an auxiliary seat valve 39 are provided.

Further, the working fluid from the P port passes through the restrictor 44, passes through the passage 59 and the passage 7, and reaches the seat valve 9 of the adjustment spool 3. Similarly, it also flows into the auxiliary valve spring chamber 31 from the passage 7, and the spring 55 of the auxiliary seat valve It also acts as a closing force for the hull 39.

The control valve 19 is configured such that its control spring chamber 31 is sealed and the working fluid can flow in and out through a passage bored in the valve body, so that the pressure inside the B port or the annular chamber 20 can be controlled. spring 18
It opens when the closing force is higher than the closing force. of course,
The B1 passage and the control spring chamber 31 may be communicated through a passage provided in the body 21.

That is, the control valve 19 is opened according to the flow rate of the working fluid from the working fluid motor. On this occasion,
The opening degree of the control valve 19 is measured by the FB pin 27, which compresses the adjusting spring 10 via the intermediate pin 29, counteracting the force of the plunger 2 protruding in proportion to the signal input to the proportional solenoid 1; Pushing the adjustment spool 3 acts as a closing force for the seat valve 9.

Next, when a predetermined electric signal is input to the proportional solenoid 1, the adjustment spool 3 is pushed and the seat valve 9
opens, and the working fluid in the auxiliary valve spring chamber 40 flows out to the T port through the hole 14, the annular chamber 16, and the passage 47, and then flows through the P port to the throttle 44 and the second control spring chamber 4.
8. The amount of working fluid flowing in through the passages 59 and 7 is smaller than the amount flowing out to the T port due to the restriction 44, so the working fluid acts as a closing force for the valves in the second control spring chamber 48 and the auxiliary valve spring chamber 40. Pressure decreases.

As a result, the second control valve 43 is opened, the P port and the A port communicate with each other, and the working fluid flows into the connected motor.

In addition, the auxiliary seat valve 39 also has the same valve spring chamber 40.
As a result, the pressure inside the control spring chamber 31 is released from the B1 passage to the T port, and since the working fluid pressure is lower than the pressure acting on the B passage, the pressure flows out from the B port to the T port via the B1 passage. It has a function of causing fluid to flow out to the T port in an amount whose flow rate is measured by the control valve 19.

That is, as described above, the opening degree of the control valve 19 is
Adjustment spool 3 measured by FB pin 27
acts as a closing force for the seat valve 9, and when the seat valve 9 is closed, the flow of working fluid to the T port is prevented, and the auxiliary seat valve 39 is moved in the closing direction as a reaction, reducing the flow rate from B1 to the T port. Since the fluid pressure in the throttle, B1, or the control spring chamber 31 increases,
The control valve 19 can flow into the T port in an amount that controls the flow rate of the working fluid proportional to the magnitude of the input electrical signal.

Therefore, in this electrohydraulic proportional valve, when it is in a stationary state and no electric signal is input, the control working fluid is not consumed and the operating working fluid does not flow in or out, so that the motor is held stationary.

In this electrohydraulic proportional valve, the working fluid flows from the P port, through the A port, the working fluid motor, and the B port to the T port, and is controlled in proportion to an input electrical signal.

That is, the working fluid motor is constrained by the working fluid regardless of variations in its working load, and is controlled at an operating speed proportional to the input electrical signal.

Example 5 The electrohydraulic proportional valve of Example 4 is provided with the aforementioned amplification seat valve 53 to amplify the signal generated by the working fluid for controlling the second control valve 43 and the auxiliary seat valve 39 generated by the adjustment spool 3. It's also good to let them do it.

The electrohydraulic proportional valve shown in FIG. 8 basically has the same structure as the electrohydraulic proportional valve shown in FIG.

That is, an amplifying seat valve 53 is provided between the passage 59 and the passage 47 connected to the T port, and the amplifying seat valve spring chamber 54 communicates with the passage 7, and when the amplifying seat valve spring chamber 54 is closed, the aperture 52 bored in the valve body is opened. The working fluid from the P port reaches the seat valve 9 of the regulating spool 3 through the hole, and the amplifying seat valve 53
When the valve is opened, a passage 59 communicating with the second control spring chamber 48 and the auxiliary valve spring chamber 40 is connected to a passage 47 leading from the annular chamber 51 to the T port.

Embodiment 6 The electrohydraulic proportional valve shown in FIG.
Similar to the electrohydraulic proportional valve shown in Fig. 8 and Fig. 8, a control valve 19 and an auxiliary seat valve 39 are provided between the B port and the T port from the working fluid motor to control the working fluid motor in proportion to the input signal. However, in contrast to the electrohydraulic proportional valve of the present invention of the type in which the control spring chamber 31 and the adjustment spring chamber 15 are not independently communicated with each other, the control spring chamber 23 and the adjustment spring chamber 23 shown in FIG. This is an application example using a type of electrohydraulic proportional valve in which the adjustment spring chamber 15 is in direct communication with the hole 14. The configuration is as follows.

The second control valve 43 provided between the P port and the A port is not different from the one described above, but
The working fluid in the P port that serves as the closing force for the valve flowing into the second control spring chamber 48 passes through the passage 60 from the P port and is introduced into the passage 59 communicating with the spring chamber 48 via the throttle 44. It consists of

Further, the configuration of the auxiliary seat valve 39 itself is the same as in the previous application example, but it is provided between the B port and the B1 passage, and the annular chamber 41 communicates with the B1 passage.

The control valve 19 has the same construction as that shown in FIG. 3 described above, and its annular chamber 20 provided between the B1 passage and the T port communicates with the B1 passage.

The control spring chamber 23 and the adjustment spring chamber 15 are arranged concentrically and communicate through the hole 14.
3 is connected to the T port by a passage 47, and the working fluid in the adjustment spring chamber 15 can flow out to the T port.

The same pressure as the working fluid in the T port acts on the spring chamber 23, and the control valve 19 is closed by the force of the control spring 18 against the fluid pressure in the B1 passage.
Due to the pressure higher than the force of the spring 18 in the flow of working fluid from the port to the B1 passage and the T port,
The control valve 19 will be opened depending on the amount of working fluid passing through.

Of course, the opening degree of the control valve 19 is determined by the FB pin 17.
is transmitted to the adjusting spring 10 by the force acting as a force to close the seat valve 9 of the adjusting spool 3 against the protrusion force of the plunger 2.

Therefore, through the series of steps described below, the flow rate of the working fluid can be adjusted in proportion to the magnitude of the electrical signal input to the proportional solenoid 1, and the connected working fluid motor can be controlled.

Proportional solenoid 1 according to the input electrical signal
opens the seat valve 9 of the regulating spool 3, and the working fluid in the valve spring chambers 40, 48 flows out to the T port.

Following this, the working fluid flowing into the valve spring chambers 40, 48 through the passage 60 and the passage 59 is
Since the amount of water flows in from the port through the throttle 44 and is smaller than the outflow amount, the pressure in the second control spring chamber 48 and the auxiliary seat valve spring chamber 40 decreases.

First, the second control valve 43 opens to communicate the P port and the A port connected to the working fluid motor, and then the auxiliary seat valve 39 opens.

At this time, the auxiliary seat valve 39 is
The control valve 19 opens due to the pressure increase due to the inflow of the working fluid in the B1 passage, and the FB pin 17 protrudes in accordance with the input signal according to the opening degree of the plunger. 2
transmits a force counteracting to the adjustment spring 10, causing the seat valve 9 of the adjustment spool 3 to close.

Therefore, when the seat valve 9 is closed, the working fluid is prevented from flowing out, and the pressure in the second control spring chamber 48 and the auxiliary valve spring chamber 40 increases, causing both the seat valves 4
3 and 39 are moved in the closing direction, and the working fluid is
The inflow into the B1 passage decreases and the pressure inside the passage decreases.

In other words, the auxiliary seat valve 39 is able to flow from the B port to the T port just enough for the control valve 19 to measure a flow rate of working fluid proportional to the input signal.

Therefore, when the electrohydraulic proportional valve is at rest, the control working fluid is not consumed, the inflow and outflow of the operating working fluid is also prevented, and the working fluid motor is held fixed.

The above series of operations is completely equivalent in function to the electrohydraulic proportional valve shown in FIGS. 7 and 8. Thus, the connected working fluid motor is constrained by the working fluid regardless of variations in its working load and is controlled at an operating speed proportional to the input electrical signal.

Embodiment 7 An amplifying seat valve 53 is provided in the electrohydraulic proportional valve shown in FIG. The signal can be amplified.

That is, the structure of the electrohydraulic proportional valve shown in FIG. 10 is basically the same as the electrohydraulic proportional valve shown in FIG. and control spring chamber 2
The above-mentioned amplification seat valve 53 is installed between the passage 42 that leads to the T port through the passage 59, and the passage 59 is provided in the valve 53 itself, and the amplification valve spring chamber 54 and the seat valve 9 connected thereto are connected through the hole. It communicates with passage 7 leading to.

Therefore, the signal input to the proportional solenoid 1 opens the seat valve 9 and the working fluid starts flowing out to the T port, and as the pressure in the spring chamber 54 decreases, the amplification seat valve 53 opens and the second control spring Room 48
and the working fluid in the auxiliary valve spring chamber 40 is transferred to the annular chamber 5.
1 through the passage 42 to the T port, and both valves 43 and 39 are opened.
This electrohydraulic proportional valve is suitable for handling large amounts of working fluid.

As described above, in the electrohydraulic proportional valve of the present invention shown in FIGS. 7 to 10, the control valve 19 measures the flow rate of the working fluid by the unit shown in FIG. Two other controllable seat valves are controlled and regulated.

Effects of the Invention According to the present invention, a valve unit for controlling and adjusting the stroke of a controlled seat valve, spool, etc. can be simplified, and a working fluid motor can be connected without being affected by load. etc. can be controlled and adjusted.

Due to the above-mentioned configuration, which is a feature of the electrohydraulic proportional valve of the present invention, during operation, the adjustment spool equipped with a long cylindrical vibration-damping contact surface works with the seat valve as the adjustment valve, and the control fluid in between acts on the adjustment spool. Vibration damping is possible.

In addition, the adjustment spool having the seat valve allows fine adjustment of the target value/actual value via the feedback pin when adjusting the opening degree of the control valve.
It has the advantage of being able to convert electrical signals into hydraulic signals and having excellent responsiveness.

Further, according to the structure of the present invention, the source pressure is supplied to the control spring chamber and acts as a pilot pressure, so when used in a directional control valve, as in the first embodiment, for example, there is an advantage that responsiveness is extremely improved.

Furthermore, since the control spool's poppet-type seat valve is configured to release the pressure oil in the control spring chamber to the T port, it is not affected by dirt in the oil.
Proportional electrohydraulic system that operates smoothly, is responsive, can control and adjust stroke control and working fluid flow, is simple to configure, is reliable, and does not require a hydraulic adjustment circuit to dampen hydraulic vibrations. A valve is obtained.

[Brief explanation of the drawing]

1 to 3 show an electrohydraulic proportional valve of the present invention, which is configured to control a control valve in proportion to the magnitude of an electric signal input to a proportional solenoid.
4 to 10 are circuit diagrams showing embodiments of the electrohydraulic proportional valve according to the present invention. FIG. 4 shows a case where this electrohydraulic proportional valve is suitable for a directional switching valve. FIG. 5 shows a case where a second control valve is provided between the P port and the A port to stably control and adjust two controllable seat valves. FIG. 6 shows a case where an amplifying seat valve is further added to the example of FIG. 5. FIG. 7 shows a case where the flow rate of the working fluid is measured using an electrohydraulic proportional valve, and two other controllable seat valves are thereby controlled and adjusted. Figure 8 is the 7th
This is the case where an amplifying seat valve is added to the example shown in the figure. Figure 9 shows that the flow rate of the working fluid is measured by the unit of Figure 3, in which the control spring chamber and the adjustment spring chamber communicate with each other through holes, and the flow rate of the working fluid is measured accordingly. This is a case of controlling and adjusting. FIG. 10 shows a case where an amplifying seat valve is added to the example of FIG. 9. 1... Proportional solenoid, 2... Plunger,
3... Adjustment spool, 4... Spool housing, 5... Plug, 6... Adjustment screw, 7... Passage, 8... Hole, 9... Seat valve, 10... Adjustment spring, 11... Washer, 12...front chamber, 13
... Passage, 14 ... Hole, 15 ... Adjustment spring chamber, 1
6, 20... annular chamber, 17, 27... FB pin,
18... Control spring, 19... Proportional valve, 21... Body, 22... Throttle, 23, 31... Control spring chamber,
24... Compensation cylinder, 25... Compensation piston, 26... Safety catch, 28... Annular chamber, 29... Intermediate pin, 30... Hole passage, 32...
Spring bearing part, 33... Control spool, 34, 3
6, 38... passage, 35, 37... aperture, 43...
...Second control valve, 39...Auxiliary seat valve, 53...
Amplified seat valve.

Claims (1)

[Claims] 1. A plunger of a proportional solenoid is in contact with one end of an adjustment spool that is slidably inserted into a spool housing that is inserted and fixed into a center hole of an end cover that is fixed to an end face of a valve body. , and the adjustment spring in the adjustment spring chamber formed by the inner end of the spool housing and the inner end of the center hole of the end cover comes into contact with the seat valve side at the other end, and a reaction force in the direction of the plunger is applied. A control valve that closes the port by a control spring in a control spring chamber formed by the inner inner end of the end cover and the valve hole of the body is disposed coaxially with the proportional solenoid and the adjustment spool, and is in contact with the inner end of the control valve. The feedback pin is configured to apply a reaction force in the plunger direction to the adjustment spool via the adjustment spring, and the adjustment spring chamber and the control spring chamber communicate with each other through a plurality of holes provided in the peripheral wall of the adjustment spring chamber. A front chamber is provided between the inner end surface of the proportional solenoid and the outer end surface of the spool housing for pressurizing the end surface of the adjusting spool on the plunger side to balance the pressure of the adjusting spool, and communicating the front chamber with the control spring chamber. A working fluid for controlling the control valve is connected to a passageway and a passageway that reaches the seat part of the seated valve of the regulating spool and communicates with the regulating spring chamber through a plurality of holes provided in the wall of the spool housing by the release of the seated valve. The opening of the control valve is controlled by the stroke of opening the seat valve and then opening the control valve by the protrusion of the plunger of the proportional solenoid. 1. An electrohydraulic proportional valve characterized in that the valve has a stroke of closing a seat valve by compressing an adjustment spring in response to an electric current, and opens and closes a control valve in response to an electrical input to a proportional solenoid. 2. The plunger of the proportional solenoid is in contact with one end of the adjustment spool, which is slidably inserted into the spool housing which is inserted and fixed into the center hole of the end cover which is fixed to the end surface of the body, and the plunger of the proportional solenoid is in contact with the other end of the adjustment spool, and the seat valve is attached to the other end. An adjustment spring in an adjustment spring chamber formed by the inner inner end of the spool housing and the inner inner end of the center hole of the end cover comes into contact with the side, and a reaction force in the direction of the plunger is applied to the inner inner end of the end cover. A control valve that closes the port by a control spring in a control spring chamber formed by a valve hole in the body and a proportional solenoid is arranged coaxially with the regulating spool, and a feedback pin that abuts the inner end of the control valve closes the port. A compensating piston is housed in a compensating cylinder and is engaged with the compensating piston, which is engaged with an adjusting spring via an intermediate pin that slides in the cylinder, and applies a reaction force to the adjusting spool in the direction of the plunger, thereby causing the piston to The internal pressure of the control spring chamber acts on one end surface of the control spring chamber, and the internal pressure of the adjustment spring chamber acts on the other end surface through the through hole of the intermediate pin. The feedback pin does not compress the adjustment spring with fluid pressure when supplying the control working fluid, and the front chamber is used as a proportional solenoid to pressurize the end face of the adjustment spool on the plunger side and balance the pressure of the adjustment spool. is provided between the inner end surface of the spool housing and the outer end surface of the spool housing, and has a passageway to the adjustment spring chamber, and a passageway that branches from the passageway, reaches a seat valve of the adjustment spool, and communicates with the adjustment spring chamber when the seat valve is opened. Connect the inlet port X of the working fluid for control of the control valve, connect the annular chamber that communicates with the adjustment spring chamber through a plurality of holes with the front chamber through a passage, and connect the annular chamber to the outlet port Y of the working fluid. The protrusion of the plunger of the proportional solenoid opens the seat valve and then the control valve, and the feedback pin that comes into contact with the inner end of the control valve opens the intermediate pin according to the opening degree of the control valve. An electrohydraulic proportional valve characterized in that the valve has a stroke of closing a seat valve by pressing an adjustment spring through the valve, and opens and closes the control valve in response to electrical input to a proportional solenoid. 3. The spool housing of the adjustment spool has a screw-fastened structure, and the spool housing is positioned relative to the adjustment spool by an elastic body that comes into contact with the spool housing and an adjustment spring that compresses the elastic body. Electrohydraulic proportional valve of item 1 or item 2.