JPS62233578A - Piezoelectric element type valve - Google Patents

Abstract

PURPOSE:To make a setting pressure alteration performable at high speed, by receiving reaction force at a time when a valve body moves in a direction closing a valve seat by extension of a piezoelectric element laminated body for valve body control use, with a position device. CONSTITUTION:When there is no voltage command for a piezoelectric element laminated body 10, a valve body 15 has no pressing force to a valve seat 3, whereby pressure oil to be fed out of an input port 4 flows into an outlet port 6 after passing through a space between the valve seat 3 and the valve body 15. From this state, first at adjusting screw 16 is operated, setting the regulating position of a movable body 9, and afterward, when voltage is impressed on the piezoelectric element laminated body 10 by a pressure setter 17, the right side of the movable body 9 is positioned by the adjusting screw 16 so that the movable body 9 is extended to the side of the valve seat 3 centering on this spot.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) This invention relates to improvements in movable mechanisms for opening and closing passages in various valves.

(Prior art) A valve is a general term for equipment with a movable mechanism that can open and close a passage to pass, stop, or control fluid, and in particular to change the shape of flow or control pressure or flow rate. Functionally, control valves can be broadly divided into directional control valves, pressure control valves, and flow control valves.

Conventionally, a proportional solenoid system has been widely used as a mechanism for moving a valve body. As an example, in the pressure control valve shown in FIG. 5, a valve seat 3 is provided in the valve chamber 2, and a passage 5 on the inlet port 4 side and a passage 7 on the outlet port 6 side are connected to the valve seat 3 and the valve chamber. 2. A movable element 25 is movably fitted into the valve chamber 2, and a solenoid 26 is disposed around the outer periphery of the movable element 25. A valve body 27 is attached to the valve body holding portion 25a of the movable element 25 via a compression coil spring 28, and the valve body 27 is pressed against the valve seat 3 so as to be openable and closable. When a current is applied to the solenoid 26, the movable element 25 moves and the compression coil spring 2
8 is compressed, and the pressing force of the valve body 27 against the valve seat 3 increases. The solenoid thrust changes proportionally according to this current value.

When the solenoid thrust and the compression coil spring 28 are balanced, the movable element 25 stops, the degree of deflection of the compression coil spring 28 is determined, and the pressing force of the valve body 27 against the valve seat 3 is also determined. When the pressure on the inlet port 4 side increases and the saw acting on the valve body 27 overcomes the elastic force of the compression coil spring 28, the valve body 27 opens the valve seat 3 and the inlet port 4 side and the outlet port 6 side communicate with each other. Then, the pressure on the inlet port 4 side decreases. Therefore,
Prevents excessive pressure rise on the inlet port 4 side. When the force acting on the valve body 27 and the elastic force of the compression coil spring 28 are balanced, the valve body 27 closes the valve seat 3. This operation is repeated and the pressure on the inlet port 4 side becomes approximately constant. In this way, the set pressure on the inlet port 4 side can be adjusted by changing the current value of the solenoid 26.

(Problems to be solved by the invention) However, in this proportional solenoid system, (a)
The solenoid thrust is not very large due to the structure of obtaining a thrust proportional to the current, and due to the demagnetization delay caused by the solenoid's inductance, the switching of the valve body is slow and the response is poor. (b) Solenoid thrust Characteristics tend to change due to thermal effects, resulting in variations in set pressure.
(c) The suction action of the solenoid acts not only on the mover but also on the body, which causes hysteresis loss, which reduces the solenoid thrust and causes a delay in the mover's operation. (d) The proportional solenoid is a magnetic circuit. It has its own drawbacks, such as the need for special processing.

Therefore, the present invention does not employ the proportional solenoid system which has various drawbacks as described above, but instead employs a novel piezoelectric element system.

Structure of the Invention (Means for Solving Problems) That is, the first invention provides a valve seat in the valve chamber, and connects the passage on the inlet port side and the passage on the outlet port side through the valve seat and the valve chamber. A valve that includes a movable mechanism that communicates with the valve chamber and has a valve body that can open and close with respect to a valve seat, wherein the movable mechanism includes a movable body that is expandable and retractable by a piezoelectric element laminate for controlling the valve body;
A positioning means is provided which receives a reaction force when the valve body attached to the movable body moves in the direction of closing the valve seat due to the extension of the movable body.

Further, in the second invention, a valve seat is provided in the valve chamber, a passage on the inlet port side and a passage on the outlet port side are communicated through the valve seat and the valve chamber, and the valve chamber can be opened and closed with respect to the valve seat. The movable mechanism includes a movable body that can be expanded and contracted by a piezoelectric element laminate for controlling the valve body and that can move within the valve chamber in the direction of expansion and contraction, and a spring that is attached to the movable body. A positioning means having a piezoelectric element laminate for clamping which can be fixed to the inner surface of the valve chamber under pressure and which is fixed to a movable body and can be moved together with the valve body is provided. A valve body housing chamber corresponding to the valve seat and a back pressure chamber on the opposite side are separated by the movable body, the positioning means 6, and the valve seat, and the back pressure chamber and the passage on the inlet port side are connected by a pilot passage. It is connected.

(Function) Then, to explain the case where the pressure-N accumulator type valve according to the first invention is used as a pressure control valve, when there is no voltage command to the piezoelectric element stack for controlling the valve body, the voltage is supplied from the inlet port. Pressure oil flows between the valve seat and the valve body to the outlet port. When a voltage is applied to the piezoelectric element laminate for controlling the valve body, this piezoelectric element fim body expands by a dimension corresponding to the applied voltage, and due to this expansion dimension, the distance between the valve seat and the valve body im+,
Or the pressure force of the valve body against the valve seat is determined. Therefore, by changing this applied voltage, the pressure on the incoming port side can be maintained at an arbitrary set value.

Moreover, the piezoelectric element type valve according to the second invention has a pressure tfiljlJ
To explain when used as a valve, valve body #II
When there is no voltage command for the piezoelectric element stack for use and clamping, the movable body and the piezoelectric element stack for clamping can move within the valve chamber, and the pressure oil supplied from the inlet port is applied to the valve seat and the valve body. and to the exit port. first,
When a voltage is applied to the piezoelectric element stack for clamping, the piezoelectric element stack for clamping expands and is fixed to the inner surface of the valve chamber. Next, when a voltage is applied to the piezoelectric element laminate for controlling the valve body, this piezoelectric M element laminate expands by a dimension corresponding to the applied pressure, and the elastic force of the spring changes depending on this expansion dimension, causing the valve body to move against the valve seat. The pressure welding force is determined. When the voltage applied to the piezoelectric element stack for clamping is cut off for a short time, the movable body and the piezoelectric element stack for clamping move toward the valve seat side due to the pressure oil flowing into the back pressure chamber from the inlet port side through the pilot passage. The pressure of the valve body against the valve seat increases. When a voltage is again applied to the clamping piezoelectric element stack after a short period of time, the piezoelectric element stack expands and is fixed to the inner surface of the valve chamber, and the movable body is positioned at this movement position.

Therefore, by changing the voltage applied to the piezoelectric element stack for controlling the valve body and carefully adjusting the voltage applied to the piezoelectric element 41iWi body for clamping, the inlet bow can be fixed. - Side pressure can be maintained at any set value.

(Embodiment) First, a first embodiment in which the first invention is embodied in a pressure control valve will be described with reference to FIGS. 1 and 2.

A valve chamber 2 is provided in the body 1, and a valve fA3 is provided on the left side of the valve chamber 2.
is formed. An inlet port 4 and an outlet port 6 are connected to the left side of the body 1, and a passage 5 on the inlet port 4 side and a passage 7 on the outlet port 6 side are connected to a valve F! 3 and the valve chamber 2.

A movable mechanism 8 for opening and closing the valve seat 3 is installed inside the valve chamber 2. That is, the movable body 9 includes a piezoelectric element laminate 10 for controlling a valve body that is expandable and retractable (pressure I! elements having a thickness of about 1+u+ are stacked so that their expansion and contraction directions are the same),
It consists of a pair of left and right guides 11 and 12 that sandwich this in one direction, and these guides 11 and 12 are in sliding contact with the inner circumferential surface of the valve chamber 2 and are movable in the direction of expansion and contraction of the piezoelectric element laminate 10. It has become. An O-ring 13 is fitted into the left guide 11 corresponding to the valve seat 3, and a valve body housing chamber 2a is provided between the guide 11 and the valve seat 3. This guide 11
A valve body holding portion 14 is provided to protrude toward the valve seat 3, and a fitting shaft 5I115a formed on the valve body 15 is movably fitted into a fitting hole 14a formed in the holding portion 14. . This valve body 15 is designed to be able to open and close the valve seat 3. An Ilm screw 16 is screwed onto the right side of the body 1 corresponding to the right side guide 12, and its inner end is connected to this guide 12.
It is designed so that it can come into contact with the This adjustment screw 16 controls the rightward movement of the movable body 9 so that when the valve body 15 moves in the direction of closing the valve seat 3 due to the expansion of the piezoelectric element laminate 10 (in the direction of the arrow), it receives the reaction force. do.

Each piezoelectric element of the piezoelectric element body 10 is connected to a pressure setting device 17. The pressure setting device 17 outputs a predetermined voltage command to the piezoelectric element based on input from a pressure sensor (not shown) that detects the pressure on the inlet port 4 side. Note that it is also possible to use a part of the piezoelectric element laminate 10 as a pressure sensor in place of the pressure sensor.

Now, if there is no voltage command for the piezoelectric element stack 10,
The valve body 15 is either separated from the valve seat 3 without any pressing force against the valve seat 3, or is held by the valve body holding portion 14 of the movable body 9 in a state where it can be separated.

Pressure oil supplied from the input port 4 passes between the valve seat 3 and the valve body 15 and flows to the outlet port 6.

From this state, first operate the adjustment screw 16 to determine the movement restriction position of the movable body 9, and then apply voltage to the piezoelectric element laminate 10 using the pressure setting device 17.
0 is extended in the direction of arrow A by a dimension corresponding to the applied voltage. At this time, since the right side of the movable body 9 is positioned by the adjustment screw 16, the movable body 9 is extended toward the valve seat 3 with this as the center. Due to this expansion, the valve body 15
moves in the direction of closing and is pressed against it. When the valve seat 3 is closed by the valve body 15, the flow from the inlet port 4 side to the outlet port 6 side is blocked, and the pressure on the inlet port 4 side increases. The pressure on the inlet port 4 side is detected by the pressure sensor, and this detected pressure is input to the pressure setting device 17. When this detected pressure becomes higher than the set value of the pressure on the inlet port 4 side, the applied voltage is changed according to the pressure difference, and the piezoelectric element stack 10 contracts in the direction opposite to the arrow A.

Due to this contraction, the valve seat 3 and the valve body 15 as shown in FIG.
A gap S is formed between the two, and the pressure oil on the inlet port 4 side flows through this gap S to the outlet port 6 side, and the pressure on the inlet port 4 side decreases. When this pressure approaches the set value, the applied voltage is changed according to the pressure difference, and the piezoelectric element stack 10 expands again and the valve seat 3 is closed by the valve body 15, or the valve seat 3 and the valve The gap S between the body 15 becomes narrower.

In this way, by changing the applied voltage according to the pressure on the inlet port 4 side, the expansion and contraction dimensions of the piezoelectric element laminate 10 are changed, and the valve seat 3 is closed or the valve seat 3 and the valve body 15 are closed. By increasing or decreasing the gap S, the pressure on the inlet port 4 side can be maintained at an arbitrary set value.

On the other hand, as another control method, the expansion and contraction of the piezoelectric cord w4 layer body 10 is controlled by the pressure setting device 17 so that an arbitrary gap S can always be secured between the valve seat 3 and the valve body 15. For example, the restricting resistance of this gap S enables pressure control and flow rate control.

Next, a second embodiment in which the first and second inventions are embodied in a pressure control valve will be described with reference to FIG. 3, focusing on the differences from the first embodiment.

Inside the movable body 9, another piezoelectric element laminate 18 for clamping is integrally sandwiched between the piezoelectric element laminate 10 for controlling the valve body and the right side guide 12, and is movable within the valve chamber 2 together with the movable body 9. It is. Each piezoelectric element of this clamping piezoelectric element stack 18 is connected to a pressure setting device 17. The piezoelectric element laminate 18 is expanded by the applied voltage from the pressure setting device 17 and can be fixed to the inner surface of the valve chamber 2 under pressure. This piezoelectric element laminate 18 for clamping prevents the movable body 9 from moving to the right so that it receives a reaction force when the valve body 15 moves in the direction of closing the valve seat 3 due to the expansion of the piezoelectric element laminate 10 for controlling the valve body. One regulation. Valve body housing chamber 2 in valve chamber 2
In a, the valve body 15 is connected to this and the left guide 1 of the movable body 9.
1 and is pressed against the valve seat 3 by a compression coil spring 19 for the valve body. A compression coil spring 20 for returning the movable body is interposed between the inner surface of the valve body housing chamber 2a and the left side guide 11. An O-ring 21 is fitted into the right guide 12 of the movable body 9, and the inside of the valve chamber 2 is partitioned by the movable body 9 and the piezoelectric element laminate 18 for clamping therein, and the inside of the valve chamber 2 is divided into the valve body housing chamber 2a and the opposite side thereof. A back pressure chamber 2b is provided. This back pressure chamber 2b and the passage 5 on the side of the inlet port 4 are communicated through a pilot passage 22. A throttle 23 is provided in the passage 5 on the inlet port 4 side between the pilot passage 22 and the inlet port 4.

Now, piezoelectric element laminate 10 for valve body control and clamping.
When there is no voltage command in 18, the movable body 9 and the piezoelectric element laminate for clamping 18 are movable within the valve chamber 2, and the valve body 15 has no pressure contact force against the valve seat 3. Separated or ready to be separated. Pressure oil supplied from the inlet port 4 passes between the valve seat 3 and the valve body 15 and flows to the outlet port 6.

From this state, first operate the one-bar screw 16 to determine the movement restriction position of the movable body 9, and then apply voltage to the clamping piezoelectric element laminate 18 using the pressure setting device 17. It is extended and fixed to the inner surface of the valve chamber 2. Next, when a voltage is applied to the valve body control piezoelectric element stack 10 by the pressure setting device 17, the valve body control piezoelectric element stack 10 is expanded in the direction of arrow A by a dimension corresponding to the applied voltage. At this time, since the movable body 9 is positioned by the clamping piezoelectric element stack 18, the movable body 9 is extended toward the valve seat 3 with this as the center. Due to this expansion, the valve body compression coil spring 19 is compressed, and the valve body 15 is pressed against the valve seat 3. When the valve seat 3 is closed by the valve body 15, the flow from the inlet port 4 side to the outlet port 6 side is blocked, and the pressure on the inlet port 4 side increases.

In this state, when the voltage applied to the clamping piezoelectric element li layer body 18 is cut off for a short time, the pressure oil flowing from the inlet port 4 side through the pilot passage 22 into the back pressure chamber 2b guides the right side of the movable body 9. Acts on 12. As a result, the movable body 9
The clamping piezoelectric element stack 18 moves toward the valve seat 3 against the biasing force of the movable body return compression coil spring 20, and the pressing force of the valve body 15 against the valve seat 3 increases. When voltage is applied to the piezoelectric element stack 18 for clamping again after a short time, the piezoelectric element stack 18 for clamping expands and is fixed to the inner surface of the valve chamber 2, and the movable body 9 is positioned at this movement position. Ru.

The pressure on the inlet port 4 side is detected by a pressure sensor, and this detected pressure is input to the pressure setting device 17. When this detected pressure becomes higher than the pressure setting value on the inlet port 4 side,
The force acting on the valve body 15 overcomes the elastic force of the compression coil spring 19 for the valve body, and the valve body 15 opens the valve seat 3 to communicate the inlet port 4 side and the outlet port 6 side, and the pressure on the inlet port 4 side is reduced. goes down.

Therefore, excessive pressure rise on the inlet port 4 side can be prevented, and the pressure on the inlet port 4 side can be maintained at an arbitrary set value.

When the voltage applied to the valve body control piezoelectric element stack 10 is changed, the valve body control piezoelectric element stack 10 expands and contracts in accordance with the applied voltage, and the amount of deflection of the valve body compression coil spring 19 changes. The pressing force of the valve body 15 against the valve seat 3 is determined according to this amount of deflection, and the set pressure on the inlet port 4 side can be changed.

When the cutting time of the piezoelectric element laminate 18 for clamping is changed, the fixing position of the piezoelectric element laminate 18 for clamping is changed. Therefore, the valve body 1 by the piezoelectric element laminate 10 for controlling the valve body
In addition to adjusting the pressure contact force of the valve body 15, the pressure contact force of the valve body 15 can also be adjusted by this piezoelectric element laminate 18 for clamping.

When the voltage applied to the valve body control and clamping piezoelectric element stack 10°18 is cut off, the valve body control piezoelectric element stack 10 contracts in the direction of the arrow A, the valve seat 3 opens, and the pressure oil on the inlet port 4 side is released. flows to the exit port 6 side. Since there is a throttle 23 in the passage 5 on the side of the inlet port 4, this throttle 23 and the valve seat 3
The pressure becomes low between the two, and the pressure oil in the back pressure chamber 2b passes through the pilot passage 22 and flows back into the passage 5 on the inlet port 4 side. As a result, the movable body 9 and the clamping piezoelectric element laminate 18
is returned to the right by the movable body return compression coil spring 20 and stops when it comes into contact with the adjustment screw 16.

The third embodiment shown in FIG. 4 replaces the movable body return compression coil spring 20 in the second embodiment with a back pressure chamber 2b.
A tension coil spring 24 for returning the movable body is provided, and both ends thereof are fixed to the right side guide 12 of the movable body 9 and the inner surface of the back pressure chamber 2b.The function of this third embodiment is the same as that of the second embodiment. It is similar to

Effects of the Invention In short, according to the first invention, since the conventional proportional lenoid system is not adopted and a piezoelectric element system is adopted instead, it is possible not only to eliminate the drawbacks peculiar to the proportional lenoid system, but also to ) The set pressure can be changed quickly, resulting in better responsiveness and better prevention of pulsation.
(b) Power consumption can be reduced, there is no need to worry about overheating, and miniaturization is possible. (c) The number of parts can be reduced and the structure simplified. (d) The same structure can be maintained by changing the control method. (e) Depending on the control method, it is possible to create a relief valve without contact between the valve body and the valve seat, reducing valve noise and improving product life. There are various advantages.

Further, according to the second invention, there are effects similar to those in (a) to (d) except for (e) among the effects of the first invention, and in addition, the valve body pressure contact force by the piezoelectric element laminate for controlling the valve body is reduced. In addition to the adjustment, M nodes of the pressure contact force of the valve body by the pilot passage and the piezoelectric element stack for clamping can be performed, so that fine pressure control over a wide range is possible, which has the effect of improving controllability.

[Brief explanation of drawings]

Fig. 1 is a top view showing the pressure control valve according to the first embodiment, Fig. 2 is a partially enlarged sectional view showing the valve seat and valve body in the first embodiment, and Fig. 3 is a top view showing the pressure control valve according to the first embodiment. FIG. 4 is a sectional view showing a pressure control valve according to a third embodiment, and FIG. 5 is a sectional view showing a conventional pressure control valve. In the figure, 2 is a valve chamber, 2a is a valve body storage chamber, 2b is a back pressure chamber, 3
1 is a valve seat, 4 is an inlet port, 6 is an outlet port, 8 is a movable mechanism, 9 is a movable body, 10 is a piezoelectric element laminate for controlling the valve body, 1
5 is a valve body, 16 is an adjustment screw (positioning means), 18 is a piezoelectric element stack for clamp (positioning means), 19 is a compression coil spring for the valve body, 20 is a compression coil spring for movable body return, and 22 is a pilot passage. , 24 are tension coil springs for returning the movable body.

Claims (1)

[Scope of Claims] 1. A valve seat is provided in the valve chamber, and a passage on the inlet port side and a passage on the outlet port side are communicated via the valve seat and the valve chamber, and the valve chamber is configured to open and close with respect to the valve seat. In this valve, the movable mechanism includes a movable body that can be expanded and contracted by a piezoelectric element stack for controlling the valve body, and the valve body attached to this movable body moves the valve seat by the expansion of the movable body. A piezoelectric element type valve comprising positioning means that receives a reaction force when the valve moves in the closing direction. 2. The movable body is movable within the valve chamber in the direction of expansion and contraction of the piezoelectric element laminate for controlling the valve body, and the positioning means is configured to receive the reaction force when the valve body moves in the direction of closing the valve seat due to the expansion of the movable body. The piezoelectric element type valve according to claim 1, which is an adjustment screw that can come into contact with the movable body. 3. The movable body is movable within the valve chamber in the direction of expansion and contraction of the piezoelectric element laminate for controlling the valve body, and the positioning means is a piezoelectric element laminate for clamping that can be fixed to the inner surface of the valve chamber by pressure, and is fixed to the movable body. A piezoelectric element valve according to claim 1, which is movable together with the piezoelectric valve. 4. A valve seat is provided in the valve chamber to communicate the passage on the inlet port side and the passage on the outlet port side via the valve seat and the valve chamber, and the valve chamber has a valve body that can be opened and closed with respect to the valve seat. In a valve equipped with a movable mechanism, the movable mechanism includes a movable body that can be expanded and contracted by a piezoelectric element laminate for controlling the valve body and that can be moved within the valve chamber in the direction of expansion and contraction, and a spring attached to the movable body that moves the movable body against the valve seat. A pressure-welded valve body and a positioning means having a piezoelectric element stack for clamping which can be fixed to the inner surface of the valve chamber by pressure contact and which is fixed to a movable body and can be moved together with the movable body are provided. A piezoelectric element valve comprising a valve body housing chamber corresponding to a valve seat and a back pressure chamber on the opposite side, which are divided by a means, and the back pressure chamber and a passage on the inlet port side are communicated by a pilot passage. .