JPH0337669B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an electronic valve that directly opens and closes a valve seat with a valve body provided on an electrostrictive element, and more specifically,
The present invention relates to an electronic valve in which a driving power source for such an electrostrictive element is integrally provided in a valve body.

(Prior Art) As a directional control valve used in a pneumatic circuit, an electronic valve that directly opens and closes a valve seat using an electrostrictive element is attracting attention.

First, the basic configuration of the electronic valve already proposed by the applicant will be explained.

Figure 4 is a sectional view showing the basic configuration of the electronic valve;
The figure is a perspective view showing an example of an electrostrictive element used in the electronic valve.

The valve body 1 has an air space 1 in the center that is open at the top.
00 is formed. In addition, main unit 1 has an import IN, an out port OUT, and an exhaust port EXH.
is provided. Import IN is flow path 10
1 to an annular air space 102. The outport OUT is in direct communication with the air space 100. Exhaust port EXH is flow path 106
It communicates with an annular air space 107 via.

The main body 1 is provided with valve seat members 11 and 12. The valve seat members 11 and 12 have valve seats 11a and 1 at their tips.
It is a cylindrical member having a diameter 2a, and threaded portions 11b and 12b are provided on the outer periphery of the cylinder. The rear ends of the valve seat members 11 and 12 are sealed with fillers 13 and 14, forming air spaces 104 and 109 inside, and the air spaces 104 and 109 communicate with the outer air spaces 102 and 107, respectively. flow path 103,
Flow paths 105 and 110 are provided which communicate with the openings of the valve seats 11a and 12a.

The valve seat members 11, 12 are O-rings 15, 15a,
It is positioned and fixed to the main body 1 via screw portions 11b and 12b while maintaining airtightness via screw portions 16 and 16a. At this time, the air space 102 communicating with the import IN communicates with the air space 100 of the main body 1 via the flow path 103, air space 104, and flow path 105 of the valve seat member 11. Similarly, the air space 107 communicating with the exhaust port EXH is the flow path 1 of the valve seat member 12.
08, an air space 109 communicates with the air space 100 of the main body 1 via a flow path 110. Note that the valve seats 11a and 12a of the valve seat members 11 and 12 are provided facing each other.

As shown in FIG. 5a, 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. If two electrostrictive elements 3 are stacked on top of each other as shown in Figure 5b, the force due to strain can be reduced by 2.
Can be doubled.

The electrostrictive element 3 is connected to lead wires 35 and 36, and is connected to the front side of the two piezoelectric ceramics and the metal plate 33.
It is soldered on the side. A resistor 34 is connected to the lead wires 35 and 36. The upper end of the electrostrictive element 3, the connection portion between the lead wires 35, 36, and the resistor 34 are integrally molded with a polymeric material 18. This is to prevent accidents such as poor contact and disconnection due to high-speed operation of the electrostrictive element 3, thereby improving the reliability of the valve. The reason why the resistor 34 is inserted is to discharge the electric charge accumulated in the electrostrictive element 3 when the electrostrictive element 3 is made non-conductive, thereby making it easier for the electrostrictive element 3 to return to its original state. The lid 10 has screws 19, 19
The central part of the lid 10 is sealed with a bush 10a. At the tip of the electrostrictive element 3, valve bodies 41 and 42 are connected to the valve seat 11 of the valve seat members 11 and 12.
a, 12a. The element holder 17 seals the air between the upper part of the air space 100 and the outside, and is further completely sealed with a polymer material 18. The element holder 17 is made of an elastic material such as rubber and has a rectangular shape along the electrostrictive element 3, and is fitted into the main body 1. This is to reduce the size of the valve, reduce the capacity of the air space 100, and improve load response.

Next, the operation of the basic electronic valve will be explained.

When the lead wires 35 and 36 are not energized, the electrostrictive element 3 is not distorted.
A valve body 41 provided in the valve seat 11a closes the valve seat 11a. For this reason, from the import IN to the flow path 101,
air space 102, flow path 103, air space 104,
Air pressure supplied via flow path 105 is blocked.

If the lead wires 35 and 36 are now energized, the electrostrictive element 3 will be distorted to the right. Therefore, the valve body 41 provided on the electrostrictive element 3 opens the valve seat 11a, and the valve body 42 closes the valve seat 12a. Therefore, from import IN to flow path 101 and air space 1
02, flow path 103, air space 104, flow path 105
The air pressure supplied through the air space 10
0 and flows to the outport OUT.

When the power to the lead wires 35 and 36 is stopped,
The electrostrictive element 3 returns to its original state due to its own rigidity. Therefore, the valve body 41 closes the valve seat 11a,
The valve body 42 opens the valve seat 12a. Therefore, the air pressure from the outport OUT is the air space 100,
Exhaust port via flow path 110, air space 109, flow path 108, air space 107, flow path 106
Exhausted from EXH.

(Problems to be Solved by the Invention) The electrostrictive element used in such an electronic valve consumes extremely little power, so it has the advantage of being directly driven by an IC or the like.

However, the power supply for ICs, etc. is about 3 to 18V, and the electrostrictive element produces distortion that is approximately proportional to the applied voltage. is unable to function as a valve due to insufficient strain and seating force.

An object of the present invention is to provide an electronic valve that can be directly driven by a weak signal from an electronic control circuit by integrally providing an electrostrictive element driving power source in the electronic valve.

(Means for Solving the Problems) In order to achieve the above object, the electronic valve according to the present invention has a valve body provided in an electrostrictive element having a bimorph structure, and a valve body provided in a valve body according to a control signal from an electronic control circuit. In the electronic valve that opens and closes the valve seat, an oscillator, a multi-voltage rectifier circuit that rectifies the output of the oscillator into a multi-voltage multiplier, and the electrostrictive element are connected in parallel, and the multi-voltage rectifier circuit a semiconductor switch connected to an output terminal of the switch; and a drive circuit that turns on the oscillator and turns off the semiconductor switch when the control signal is present, and turns off the oscillator and turns on the semiconductor switch when the control signal is not present. The electrostrictive element driving power source and the electronic valve body are integrated.

(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 an electronic valve according to the present invention. Note that the same reference numerals are given to parts having the same functions as those of the conventional example described above.

A circuit board 5 is provided on the upper side of the main body 1 via a stay 50. On the circuit board 5, an electrostrictive element driving power source 6 made up of a group of electronic components is mounted. A lead wire from the electrostrictive element 3 is fixedly connected to the circuit board 5 by soldering or the like. The circuit board 5, together with the lid 10, is fixed to the main body 1 with screws 19, 19 via stays 50, 50a. Lead wires 51, 52, 53 from the circuit board 5
has been derived. The lead wire 51 is for power supply, the lead wire 52 is for ground, and the lead wire 5
3 is a lead wire for control signals.

FIG. 2 is a circuit diagram showing an embodiment of the electrostrictive element driving power source used in the electronic valve according to the present invention.

The electrostrictive element drive power supply 6 includes an oscillator 61, a multiple voltage rectifier circuit 62, a semiconductor switch 63, and a drive circuit 64.

The oscillator 61 is composed of inverters In ₁ and In ₂ , a capacitor C ₁ , a diode D ₁ , resistors R ₁ and R _2, etc., and its output is sent to the multiple voltage rectifier circuit 6.
Connected to 2.

The multiple voltage rectifier circuit 62 is a circuit for rectifying the output of the oscillator 61 into multiple voltages, and includes inverters In ₃ to In ₅ , capacitors C ₂ to C ₅ , and diodes.
It is composed of _D2 to _D6 , a resistor _R4, etc., and its output is connected to a semiconductor switch 63.

The semiconductor switch 63 has the electrostrictive element 3 connected in parallel, is connected to the output terminal of the multiplier voltage rectifier circuit 62, and has a transistor TR and a resistor R ₅ ,
It is made from _R6 . The output from the drive circuit 64 is connected to the base of the transistor TR.

A control signal from an electronic control circuit 7 configured by a microcomputer or the like is connected to the drive circuit 64. The drive circuit 64 is a circuit for turning on the oscillator 61 and turning off the semiconductor switch 63 when there is a control signal from the electronic control circuit 7, and turning off the oscillator 61 and turning on the semiconductor switch 63 when there is no control signal. It consists of an inverter In ₆ , diodes D ₇ and D ₈ , etc.

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

When the control signal from the electronic control circuit 7 is low level, the output of the inverter In ₆ of the drive circuit 64 is high level, so the oscillator 61 is turned off and the transistor TR of the semiconductor switch 63 is turned on. , the electrostrictive element 3 is non-conductive. At this time, since the electrostrictive element 3 is not distorted, the valve body 41 provided on the electrostrictive element 3 closes the valve seat 11a. Therefore, from import IN to flow path 1
01, air space 102, flow path 103, air space 1
04, the air pressure supplied via the flow path 105 is cut off.

When the control signal from the electronic control circuit 7 becomes high level, the semiconductor switch 63 is turned off and the oscillator 61 is turned on, and its output is amplified multiple times by the multiple voltage rectifier circuit 62.
It is connected to the electrostrictive element 3. At this time, the electrostrictive element 3
distorted to the right. Therefore, the valve body 41 provided in the electrostrictive element 3 opens the valve seat 11a, and the valve body 42
closes the valve seat 12a. For this reason, import
From IN to flow path 101, air space 102, flow path 10
3. Air pressure supplied through the air space 104 and flow path 105 passes through the air space 100 and flows to the outport OUT.

FIG. 3 is a perspective view showing another embodiment of the electronic valve according to the present invention.

In this embodiment, the head portion of the electronic valve will be mainly explained, and the same reference numerals are given to parts that perform the same functions as those in the previous embodiment.

The polymer material 18 that seals the opening of the main body 1 includes:
Connector pin 35a connected to electrostrictive element 3,
36a is provided. The upper surface of the main body 1 includes a connector 35b connected to the pins 35a and 36a,
A connector member 54 having 36b is provided. A stay 50 is placed on this connector member 54.
An electrostrictive element driving power source 6 mounted on the substrate 5 is provided via the substrate 5. This board 5 has a stay 50
It is fixed to the main body 1 together with the lid 10 with screws 19, 19 via the lid 10. In addition, 51a, 52a,
53a is a connector pin connected to the lead wires 51, 52, and 53.

The configuration shown in FIG. 1 has the advantage of low manufacturing cost and miniaturization.

On the other hand, with the configuration shown in FIG. 3, the electrostrictive element can be driven by a power source different from the power source for driving the electrostrictive element by disconnecting the connector. Furthermore, maintenance such as installation, removal, and replacement in case of failure is easy. Furthermore, when the drive power supply breaks down, it is only necessary to replace the drive power supply, which has the advantage of reducing costs.

(Effects of the Invention) As explained in detail above, according to the present invention,
Since the electrostrictive element drive power source is provided integrally with the electronic valve and an amplified voltage is applied to the electrostrictive element, it can be directly driven by a weak signal from an electronic control circuit such as a microcomputer.

For example, in the example shown in FIG. 2, a voltage approximately five times lower than that of the IC power supply can be obtained. In other words, if the IC power supply is 9V, the electrostrictive element can be driven with a voltage of about 45V, so sufficient functions as a valve (strain and seat force) can be obtained.

Therefore, the electronic valve can be driven for a long time with one dry battery. Further, there is no need to separately provide a power source for the electronic valve and a power source for electronic control, and the electronic valve can be driven by a single power source for electronic control. moreover,
This simplifies the electronic control circuit for driving the electronic valve, resulting in space savings and other effects.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of an electronic valve according to the present invention. FIG. 2 is a circuit diagram showing an embodiment of the electrostrictive element driving power source used in the electronic valve according to the present invention. FIG. 3 is a perspective view showing another embodiment of the electronic valve according to the present invention. FIG. 4 is a sectional view showing the basic configuration of the electronic valve, and FIG.
FIG. 2 is a perspective view showing an example of an electrostrictive element used in the electronic valve. 1...Body, 10...Lid, 10a...Button, 1
1, 12... Valve seat member, 11a, 12a... Valve seat, 1
1b, 12b...Threaded part, 15, 15a, 16, 1
6a... O ring, 17... Element holder, 18... Polymer material, 19... Screw, 3... Electrostrictive element, 31, 32
...piezoelectric ceramic, 33...metal plate, 34...resistance, 35,
36... Lead wire, 41, 42... Valve body, 5... Circuit board, 50, 50a... Stay, 54... Connector member, 6... Electrostrictive element drive power source, 61... Oscillator, 62
...Multiple voltage doubler rectifier circuit, 63...Semiconductor switch,
64...Drive circuit, 7...Electronic control circuit.

Claims (1)

[Scope of Claims] 1. An electronic valve that opens and closes a valve seat provided on a valve body using a valve body provided on an electrostrictive element having a bimorph structure in response to a control signal from an electronic control circuit, comprising an oscillator and the oscillator. a multi-voltage rectifier that rectifies the output of the multi-voltage rectifier into a multi-voltage multiplier, the electrostrictive element is connected in parallel, a semiconductor switch connected to an output end of the multi-voltage rectifier, and the control signal. The electronic valve body is integrated with an electrostrictive element drive power source comprising a drive circuit that sometimes turns on the oscillator and turns off the semiconductor switch, and when there is no control signal, turns off the oscillator and turns on the semiconductor switch. An electronic valve that is characterized by: 2. The electrostrictive element driving power source is electrically connected to the electrostrictive element by a connector member that electrically connects a pin connected to the driving power source and a pin connected to the electrostrictive element by fitting them together. An electronic valve according to claim 1.