JPS61206878A - Pressure control valve using electric strain element - Google Patents

Abstract

PURPOSE:To obtain a small-sized and lightweight control valve at a low cost by controlling the air pressure applied onto a diaphragm by electric signals by using an electric strain element as nozzle flapper. CONSTITUTION:When an electric strain element 2 closes a nozzle 11a and opens a nozzle 11b, the pressure P2 becomes equal to the atmospheric pressure, and the force F1 acting onto a joint element 5 dissipates, and a valve seat 13a is closed, and the pressure P4 becomes equal to the atmospheric pressure. When the electric strain element 2 closes the nozzle 11b and opens the nozzle 11a, the pressure P2 becomes equal to the pressure P1, and the force F becomes max., and the pressure P4 becomes equal to P3. Therefore, when the voltage applied onto the electric strain element 2 is made variable, the strain of the electric strain element 2 varies in proportion to the voltage, and each opening degree of the nozzles 11b and 11a is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure control valve using an electrostrictive element as a nozzle flamper.

(Prior art) Pneumatic equipment is largely dependent on pressure (if pressure is not maintained properly, various pneumatic equipment cannot demonstrate their full performance. For this reason, pneumatic circuits are A pressure control valve is used.The valve used when it is desired to supply a constant pressure from an air source to a pneumatic circuit is particularly called a pressure reducing valve.

This type of pressure reducing valve basically sets the compression force of the pressure regulating spring by moving an adjustment screw forward and backward by rotating the handle, and by transmitting this compression force to the diaphragm via the spring seat, the diaphragm Displace the pulp pin that contacts the valve seat provided in the center to open the pulp provided on the valve pin, connect the air on the negative side to the secondary side, and direct some of the air on the secondary side to the diaphragm. When the air pressure on the secondary side becomes lower than the set pressure, the diaphragm is pushed down by the compression force of the pressure regulating spring, displacing the valve pin and moving it in the direction of opening the valve. When the side air pressure becomes higher than the set pressure, the force through the diaphragm becomes greater than the compression force of the pressure regulating spring, so the diaphragm is pushed up, displacing the valve pin and moving the valve in the direction of closing. When the air pressure on the secondary side becomes high, the valve is closed and the valve pin moves away from the valve seat to release the air on the secondary side to the atmosphere through the relief hole provided in the valve seat. It was designed to keep the side air pressure constant.

(Problems to be Solved by the Invention) In the pressure control valve described above, the mechanical structure is large, and the adjustment screw must be moved back and forth to adjust the pressure on the secondary side, so I couldn't control it.

An object of the present invention is to use an electrostrictive element as a nozzle flapper to control the air pressure applied to a diaphragm using an electric signal, thereby making it possible to use a compact electrostrictive element to precisely control the secondary side pressure. The purpose of this invention is to provide a control valve.

(Means for Solving the Problems) In order to achieve the above object, a pressure control valve using an electrostrictive element according to the present invention includes a first nozzle communicating with a first import and facing the first nozzle. a first air space in which a second nozzle is formed and communicates with the first exhaust port; and a second air space that communicates with the second exhaust port.

A valve body having a third air space that communicates with the out port, a valve seat that opens and closes a passage that communicates from the second inlet to the out port, and an electrostrictive bimorph structure that opens and closes the first and second nozzles. an element, and the first and second
a first diaphragm that airtightly partitions the air space, a second diaphragm that airtightly partitions the second and third air spaces, and a diaphragm supported by the first and second diaphragms and connected to the second air space. A communicating sliding relief valve seat is composed of a joint formed on the third air space side, and a plunger biased in a direction to close the valve seat of the valve body and the relief valve seat of the joint. .

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings and the like.

FIG. 1 is a sectional view showing an embodiment of a pressure control valve using an electrostrictive element according to the present invention.

The valve body 1 includes blocks 11 to 13. It consists of a lid body 10°14. The block 11 has an air space 100 in which the electrostrictive element 2 operates and an air space 101 with a large diameter that communicates with the air space 100. The air space 100 has a nozzle 11a.

11b are formed to face each other. Nozzle lla is connected to import 1-4n, and nozzle llb is connected to exhaust port exh. The air pressure of pressure P1 is connected to the import in, and the exhaust port e
xh is connected to the atmosphere.

An air space 102 is formed in the block 12,
Air space 102 is connected to the atmosphere via exhaust port EXH. Air space 102 of block 12
The air space 101 of the block 11 and the air space 103 of the block 13 (described later) are respectively defined by the diaphragm 3.
, 4 to maintain airtightness. The diaphragm 3.4 supports the joint 5 in the air space 103 of the block 13. The joint 5 has an internal space 1 of the block 12.
02 and the air space 103 of the block 13 are formed.
A relief valve seat 52 is provided at the opening to 3.

Block 13 includes import) IN, outport OU
T is formed, and the out port OUT is air space 1
It is connected to 03. The import IN has the primary side air pressure P3, and the outboard 1-OUT has the secondary side air pressure P3.
4 is connected.

The block 13 is provided with a plunger 6 having an axis in the same direction as the axis of the joint 5. A valve seat 13a is located between the import IN and the output port OUT of the block 13.
is provided, and its valve seat 13a is opened and closed by the flange portion 62 of the plunger 6.

The conical part 63 formed at the tip of the plunger 6 is
The relief valve 52 of the jointer 5 is opened and closed. The plunger 6 is urged by a spring 64 in a direction to close the valve seat 13a. This spring 64 is received by the lid 14. A passage 61 is formed inside the plunger 6,
It communicates with an air space 104 formed by the plunger 6 and the lid 14. 65 to 67 are O rings that maintain airtightness.

FIG. 2 is a perspective view showing an embodiment of an electrostrictive element used in a pressure control valve using an electrostrictive element according to the present invention.

As shown in FIG. 2, the electrostrictive element 2 consists of two piezoelectric ceramics 21
．． The element has a bimorph structure in which a metal plate 22 and a metal plate 23 made of different materials are bonded together. Piezoelectric ceramic 21.2
A silver electrode is formed on the surface of 2 by baking. The piezoelectric ceramics 2] and 22 are suitably ones having a relatively large piezoelectric coefficient, and for example, lead zirconate titanate (PZT) ceramics are used. The metal plate 23 is used as an electrode, and is made of brass, for example. If two electrostrictive elements 2 are stacked together, the force due to distortion of the electrostrictive elements 2 will be doubled. 2
The same thing can be said even if more than one sheet is stacked. Further, by increasing the width of the electrostrictive element 2, a pressure contact force proportional to the width can be obtained.

The electrostrictive element 2 is connected to lead wires 71 and 72, and the lead wire 71 and the lead wire 72 are soldered to the surface side of the piezoelectric ceramic 21 and 22 and the metal plate 23, respectively. The connection between the electrostrictive element 2 and the lead wires 7] and 72 is connected to the lid 1.
0 is integrally molded with a polymeric material 10a.

This is to prevent accidents such as poor contact and disconnection due to high-speed operation of the electrostrictive element 2, thereby improving the reliability of the pressure control valve. The lid body 10 is secured to the block 11 with screws 10b, 10b.
It is connected to the.

In the present invention, the term "electrostrictive element" is used in the broadest sense, including not only an element having an original electrostrictive effect, but also a piezoelectric element having an inverse piezoelectric effect.

FIG. 3 is a circuit diagram showing an embodiment of a drive circuit for driving an electrostrictive element of a pressure control valve using an electrostrictive element according to the present invention.

The electrostrictive element 2 can be driven by either an AC power source (FIG. 3(a)) or a DC power source (FIG. 3(b)).

By adjusting the variable resistor VR, the strain of the electrostrictive element 2 can be changed. Alternatively, it can be driven directly by a control signal from a microcomputer, etc. using a multiple voltage doubler circuit (see Fig. 3 (C1)).Furthermore, by detecting pressure using a sensor S made of a piezoresistive element, etc. , it is also possible to feedback control the electrostrictive element 2. Here, the force of the resistor R1 (the reason why it is inserted is
This is to release the charges accumulated in the electrostrictive element 2 when the electrostrictive element 2 is made non-conductive, thereby facilitating recovery.

Next, the operation of the pressure control valve using the electrostrictive element according to the present invention will be explained by taking as an example the case where it is used as a pressure reducing valve. Here, the pressure reducing valve refers to a pressure control valve that controls the pressure on the secondary side to a set pressure lower than the pressure on the primary side, regardless of the pressure on the downstream side. Therefore, the pressure P3 from the pneumatic source is connected to the import IN, and the pneumatic circuit to be controlled is connected to the out port OUT, and the pressure to be controlled is F4.

When the electrostrictive element 2 is driven by the drive circuit shown in FIG.
The opening degree of the nozzles lla and llb is adjusted to control the pressure P2 in the air space 101 with respect to the import in air pressure P1. This pressure P2 acts on the diaphragm 3,
This becomes a force F1 that displaces the joint 5.

On the other hand, the pressure P4 is applied to the joint 5 via the diaphragm 4, and the force of the spring 64 is applied via the plunger 6. Therefore, if this resultant force is F2, force F1 becomes force F
If it is larger than 2, the valve seat 13a opens and invokes) I
Air pressure P3 on the N side is supplied to out port 0UT (11), and pressure P4 increases.

When the force F2 becomes larger than the force F1 due to an increase in the pressure P4, the valve seat 13a closes and the plunger 6 and
Since the joint 5 is separated and the relief valve seat 52 is opened, the air pressure from the out port OUT is transferred to the air space 103. It flows into the air space 102 through the passage 51 of the joint 5 and is exhausted to the atmosphere from the exhaust port EXH. Therefore, the pressure P4 at the outboard (outboard) OUT decreases. Therefore,
By changing the voltage applied to the electrostrictive element 2, the pressure P4 at the out port OUT can be controlled within a certain range.

In other words, the electrostrictive element 2 closes nozzle lla and nozzle llb
is open, the pressure P2 becomes atmospheric pressure, the force F1 acting on the joint 5 disappears, the valve seat 13a closes, and the pressure P2 becomes atmospheric pressure.
4 becomes atmospheric pressure. On the other hand, when the electrostrictive element 2 closes the nozzle llb and opens the nozzle lla, the pressure P2 changes to the pressure P1.
becomes equal, force F becomes maximum, and pressure P4 becomes pressure P3
is equal to

In this way, when the voltage applied to the electrostrictive element 2 is varied,
Since the strain of the electrostrictive element 2 changes in proportion to the voltage, the opening degrees of the nozzles llb and lla are controlled. Nozzle 11b
, 11a, the pressure P4 is adjusted. Therefore, the pressure P4 can be adjusted to an arbitrary pressure by the strain of the electrostrictive element 2, that is, the voltage applied to the electrostrictive element 2. will be done.

(Effects of the Invention) As explained in detail above, according to the present invention, the electrostrictive element is used as a nozzle flapper and the air pressure applied to the diaphragm is controlled by an electric signal, so the entire control valve is small and lightweight. In addition to becoming cheaper, the pressure opening can now be controlled by voltage, and the control valve can be operated remotely to precisely control the secondary pressure.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a pressure control valve using an electrostrictive element according to the present invention, and FIG. 2 is a perspective view showing an embodiment of the electrostrictive element used in the pressure control valve. Figure 3 shows
FIG. 3 is a circuit diagram showing an example of a drive circuit that drives the electrostrictive element. 1... Valve body 10.14... Lid body 11.
12.13...Blocks 100.101, 102, 103.104...Air space 10a...Polymer material 10b, 10b...Screw 113.11b...Nozzle 2...Electrostrictive element 3 .4...Diaphragm 5...Joiner 51...Passage 52...Relief valve seat 6.
...Plunger 61...Passage 62...Brim portion 63...
Conical part 64...Spring 65.66.67...
0 ring 1 figure 3 (C) (cl)

Claims (1)

[Claims] a first nozzle communicating with the first import; and a first nozzle communicating with the first import;
a first air space in which a second nozzle is formed opposite to the nozzle and communicates with the first exhaust port;
a second air space communicating with the second exhaust port;
A valve body having a third air space that communicates with the out port, a valve seat that opens and closes a passage that communicates from the second inlet to the out port, and an electrostrictive bimorph structure that opens and closes the first and second nozzles. an element, and the first and second
a first diaphragm that airtightly partitions the air space, a second diaphragm that airtightly partitions the second and third air spaces, and a diaphragm supported by the first and second diaphragms and connected to the second air space. An electrostrictive device comprising: a joint in which a communicating relief valve seat is formed on the third air space side; and a plunger biased in a direction to close the valve seat of the valve body and the relief valve seat of the joint. Pressure control valve using elements.