JPH0435649Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electronic valve in which a valve seat is directly opened and closed by a valve body provided on an electrostrictive element, and more particularly to an electronic valve in which an electrostrictive element is supported on a valve body with a both-end support structure.

Conventionally, in directional control valves used in pneumatic circuits, solenoid valves that switch valves using electromagnets have been frequently used. If you try to operate this solenoid valve at high speed, the electromagnet will become large.
Electromagnets have been an impediment to miniaturization and high-speed operation of solenoid valves. Furthermore, in the case of electromagnetic valves, there is a heavy burden on the power source and the like on the control side, resulting in large power consumption, and the accompanying heat generation causes deterioration of the elastic materials forming the valve body, seals, etc. moreover,
There was also the problem that the electromagnets generated noise when operated at high speeds.

Utility Model Application No. 57-93680 "Poppet-type flow passage opening/closing valve"
Now, regarding the valve that uses the back pressure of the nozzle flapper mechanism as the pilot pressure of the poppet valve for opening and closing the flow path,
A valve structure in which flapper operation is performed by an electrostrictive element is disclosed. However, in this structure, the pilot on-off valve uses a bleed mechanism, resulting in a large waste of air usage.

The purpose of this invention is to reduce power consumption by operating the directional control valve with an electrostrictive element, and
An object of the present invention is to provide an electronic valve that is compact and capable of high-speed operation by directly opening and closing the valve by improving the support structure of the electrostrictive element and the structure of the electrostrictive element itself.

In order to achieve the above object, the electronic valve according to the present invention has first, second and third ports in a main body and first and second valve seats in an air space in the main body, and has a first port and a first port. is connected to the first valve seat, the second port is connected to the air space, and the third port is connected to the second valve seat, and the first and second valve seats are connected to an electrostrictive structure having a bimorph structure. An electronic valve that switches the direction of fluid by driving an element to open and close, the first and second valve seats being provided facing the air space, and on both sides of the midsection of the bimorph electrostrictive element. , a first valve seat made of a material different from that of the electrostrictive element in association with the first and second valve seats.
and a second valve body, such that the first valve body of the electrostrictive element closes the first valve seat and maintains a position in which the second valve body opens the second valve seat. means is provided on both ends of the element to sandwich and support the element through cylindrical members, and to supply a voltage to the electrostrictive element, and by energizing the electrostrictive element, the first valve body is configured to open the first valve seat, and the second valve body closes the second valve seat.

According to the above structure, the object of the present invention can be completely achieved.

Hereinafter, the present invention will be explained in more detail with reference to the drawings and the like.

FIG. 1 is a sectional view showing an embodiment of an electronic valve according to the present invention, and FIG. 2 is a perspective view showing an embodiment of an electrostrictive element used in the electronic valve according to the present invention.

The valve body is composed of a main body 1 and a main body 2, and the main bodies 1 and 2 are airtightly connected by seals 9, 9 to form an air space 100. The main body 1 is provided with an import IN, which flows into the air space 100 via channels 101 and 102. Channel 102
A valve seat 11 is provided at the outlet of the air space 100. On the other hand, the main body 2 is provided with an out port OUT and an exhaust port EXH, the out port OUT communicates with the air space 100 via flow paths 103 and 104, and the exhaust port EXH
5,106 to the air space 100. A valve seat 21 is provided at the outlet of the air space 100 of the flow path 106. The diameter of the passages 102, 106 determines the capacity of the valve, ie, the flow rate of air through the passages 102, 106. In order to increase this diameter, the pressure force applied by the electrostrictive element 3 must be increased. For this reason, as will be described later, two or more electrostrictive elements 3 are used in a stacked manner.

The electrostrictive element 3 is provided in an air space 100, and the cushion rubber 51 provided on the main bodies 1 and 2
It is supported by support lines 52 in a support structure at both ends. The support wire 52 is an elongated cylindrical member, and supports the ends of the electrostrictive element 3 with two cylindrical generating lines. In this way, the cushion rubber 51,
The reason why the electrostrictive element 3 is supported by the support wire 52 is to make it easier to bend the electrostrictive element 3. A valve body 4 is provided in the center of the electrostrictive element 3, and the valve body 4 includes a valve body 41 provided opposite to the valve seat 11, and a valve body 42 provided opposite to the valve seat 21. It is configured.

As shown in FIG. 2a, the electrostrictive element 3 includes two piezoelectric ceramics 31 and 32 and a metal plate 33 made of different materials.
This is an element with a bimorph structure in which both are bonded together. Silver electrodes are provided on the surfaces of the piezoelectric ceramics 31 and 32 by baking. It is suitable for the piezoelectric ceramics 31 and 32 to have a relatively large piezoelectric coefficient; for example, lead zirconate titanate (PZT) ceramic is used. The metal plate 33 is used as an electrode, and is suitably made of brass, for example. FIG. 2b shows an example in which two electrostrictive elements 3 are stacked one on top of the other. In this way, the force due to strain on the electrostrictive element 3 is doubled. The same thing can be said even if three or more sheets are stacked. Further, by increasing the width of the electrostrictive element 3, a pressure contact force proportional to the width can be obtained.

The electrostrictive element 3 is connected to lead wires 61 and 62, and the lead wire 61 is soldered to the surface side of the piezoelectric ceramics 31 and 32, and the lead wire 62 is soldered to the metal plate 33 side. A resistor 7 is connected between the lead wires 61 and 62. The connection portions between the right end of the electrostrictive element 3, the lead wires 61 and 62, and the resistor 7 are integrally molded with a polymeric material 8. This is to improve the reliability of the valve by preventing accidents such as poor contact and disconnection due to high-speed operation of the electrostrictive element 3. The reason why the resistor 7 is inserted is to discharge the charges accumulated in the electrostrictive element 3 when the electrostrictive element 3 is made non-conductive, so that the electrostrictive element 3 can be easily restored. Therefore, the switching speed can be changed by appropriately selecting the resistance value. In reality, the electrostrictive element 3 is connected to the cushion rubber 5.
1. After supporting with support wires 52, the electrostrictive element 3 is molded integrally with the main body 1, also serving as a fixing member. For this reason, the support structure of the electrostrictive element 3 is fixed at the right end, so
In order to make it a simple support beam, the left end is designed to be rotatable and free from lateral constraints.

Next, the operation of the embodiment of the electronic valve according to the present invention will be explained.

When the lead wire 6 is not energized, the electrostrictive element 3 is not distorted, so the valve body 41 provided on the electrostrictive element 3 closes the valve seat 11. Therefore, the air pressure supplied from the import IN via the channels 101 and 102 is blocked.

Now, if the lead wire 6 is energized, the electrostrictive element 3 will be convexly distorted downward in FIG.
A valve body 41 provided in the valve body opens the valve seat 11, and a valve body 42 closes the valve seat 21. For this reason import
Air pressure supplied from IN via channels 101 and 102 passes through electrical space 100, and then passes through channels 104 and 103 to the out port OUT.
flows to

When the power supply to the lead wire 6 is stopped, the electrostrictive element 3 returns to its original state due to its own rigidity, the valve body 41 closes the valve seat 11, and the valve body 42 opens the valve seat 21. Therefore, the air pressure from the outport OUT is applied to the flow paths 103, 104, the air space 100, and the flow path 1.
The air is exhausted from exhaust port EXH via ports 06 and 105.

This embodiment has been explained using a directional control valve as an example, but by sealing the exhaust port EXH and controlling the voltage applied to the electrostrictive element 3, the flow rate of air pressure flowing from the import IN to the out port OUT is adjusted. It can also be used as a flow rate regulating valve. In addition, although this embodiment has been explained as a normally closed type control valve, the import IN and exhaust ports shown in Figure 1
If EXH is replaced, it can be used as a normally open control valve.

As described in detail above, according to the present invention, since an electrostrictive element is used, power consumption can be reduced, and the generation of heat is small, preventing deterioration of elastic members and the like. Furthermore, since the amount of strain in the electrostrictive element can be controlled by the applied voltage, it has become possible to adjust the flow rate, which has been difficult in the past. Furthermore, since a plurality of electrostrictive elements are used in a stacked manner and are supported by a support structure at both ends, it is now possible to secure the amount of strain to directly actuate the valve body. Therefore, the operation speed can be increased and the structure is simplified, so the operation can be ensured and the shape can be reduced. Specifically, the size has been reduced to about 1/2 compared to a solenoid valve with the same capacity. The switching speed can be varied by changing the value of the resistor, but it can be increased to about 500Hz at 22KΩ.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of an electronic valve according to the present invention, and FIG. 2 is a perspective view showing an embodiment of an electrostrictive element used in the electronic valve according to the present invention. 1, 2... Main body, 11, 12... Valve seat, 3...
Electrostrictive element, 31, 32... Piezoelectric ceramic, 33... Metal plate, 4, 41, 42... Valve body, 51... Cushion rubber, 52... Support wire, 6, 61, 62...
Lead wire, 7...Resistor, 8...Polymer material, 9
...Sealing material.

Claims (1)

[Claims for Utility Model Registration] (1) A main body has first, second, and third ports and first and second valve seats are provided in the air space in the main body, and the first port is connected to the first port. The second port is connected to the first valve seat, the third port is connected to the air space, and the third port is connected to the second valve seat, and the first and second valve seats drive an electrostrictive element having a bimorph structure. The electronic valve opens and closes to switch the direction of fluid, and the first and second valve seats are provided facing the air space, and the first and second valve seats are provided on both sides of the midsection of the bimorph-structured electrostrictive element. providing first and second valve bodies made of a material different from the material of the electrostrictive element in association with the first and second valve seats;
on both sides of both ends of the electrostrictive element so that the first valve body of the electrostrictive element closes the first valve seat and the second valve body opens the second valve seat. Means is provided to sandwich and support the electrostrictive element via a cylindrical member and to supply voltage to the electrostrictive element, and when the electrostrictive element is energized, the first valve body opens the first valve seat. and an electronic valve configured such that the second valve body closes the second valve seat. (2) The electronic valve according to claim 1, wherein the means for supplying voltage is configured to supply voltage by connecting a resistor in parallel to the electrostrictive element.