JPH0325467Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a directional control valve, and more particularly, to a directional control valve whose valve seat is opened and closed by a piezoelectric actuator.

[Conventional technology]

A directional control valve that utilizes the property of a piezoelectric element to be distorted when energized and opens and closes a valve seat using a valve body provided in a piezoelectric actuator using the piezoelectric element,
This is already known from Japanese Patent Application Laid-Open No. 56-76779 and Japanese Utility Model Application No. 61-152872.

However, in the above-mentioned known directional control valve, the valve seat is opened and closed by a valve body fixedly provided on a single piezoelectric actuator having one or both ends fixed, so that the seating of the valve body on the valve seat is difficult. There is a problem in that not only is the flow uneven and easy to leak, but also that the usable flow rate and pressure are limited because the sealing force is small.

In order to solve this problem, it is possible to drive the valve body using multiple piezoelectric actuators, but due to variations in the performance of piezoelectric actuators, it is difficult to simply increase the number of piezoelectric actuators. The acting force of the actuator will interfere and reduce the efficiency of the actuator.
A new problem arises in that sufficient sealing force cannot be exerted.

[The problem that the idea attempts to solve]

The problem to be solved by the present invention is to provide a directional control valve that does not reduce the efficiency of the piezoelectric actuator and improves the sealing force and sealing performance of the valve body.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a directional control valve in which a valve seat formed in a valve chamber of a valve body is opened and closed by a valve body provided on a piezoelectric actuator whose one end is fixed to the valve body. are arranged hierarchically in the opening/closing direction of the valve seat, and the amount of displacement of these is sequentially increased from the valve seat side toward the direction opposite to the closing direction of the valve seat,
The amount of displacement of the piezoelectric actuator on the valve seat side is set to be sufficient to close the valve seat, and a plurality of piezoelectric actuator groups arranged hierarchically are arranged at approximately equal angles to the valve body, and these piezoelectric actuators The valve body is characterized in that the free end of the valve body is swingably locked to the valve body.

[Effect]

When a voltage of a predetermined polarity is applied to the piezoelectric actuators, each piezoelectric actuator is distorted in one direction and the valve body closes the valve seat.

In this case, the displacement amount of the plurality of piezoelectric actuators hierarchically arranged in the closing direction of the valve seat is gradually increased from the valve seat side toward the opposite direction to the closing direction of the valve seat, and the piezoelectric actuator on the valve seat side is By making the amount of displacement sufficient to close the valve seat, the piezoelectric actuator on the valve seat side is subjected to an acting force in the direction of closing the valve seat by other piezoelectric actuators arranged hierarchically. In addition, since the displacement amount of each piezoelectric actuator was sequentially increased, the acting forces of each piezoelectric actuator did not interfere with each other.
That acting force can be used effectively. Furthermore, by arranging a plurality of the piezoelectric actuator groups at approximately equal angles to the valve body, the valve body is strongly pressed against the valve seat by the sum of the acting forces of each actuator group, so that the flow rate and pressure can be reduced. The range can be expanded dramatically.

In addition, a plurality of piezoelectric actuator groups are installed at equal angles, and the free end of each actuator is swingably locked to the valve body, so that when the piezoelectric actuator is distorted, the movement posture of the valve body is stable, and the valve seat It can be seated uniformly and improve sealing performance.

When the voltage is removed from the piezoelectric actuator or when a voltage of opposite polarity is applied, the piezoelectric actuator and the valve body return to their original positions and open the valve seat.

〔Example〕

1 and 2 show a first embodiment in which the switching valve of the present invention is a 3-port valve, and the valve body 1
is constructed by integrating main body members 1a and 1b by appropriate means, and a valve seat 2 is formed inside, and the main body members 1a and 1b are provided with an inlet port 3 and a discharge port communicating with the valve chamber. 4 is the valve seat 3a, 4
The valve chamber 2 has an output port 5 open therein.

The valve bodies 1a, 1b have an actuator group 1 consisting of piezoelectric actuators 7a, 8a, 9a.
actuators 0a are arranged hierarchically in the closing direction of the valve seat 4a, and near one end of these actuators is hermetically fitted to the peripheral wall of the main body portions 1a, 1b. Further, another actuator group 10b consisting of piezoelectric actuators 7b, 8b, and 9b is arranged on the peripheral wall of the main body members 1a, 1b, facing the actuator group 1a, and constitutes the piezoelectric actuator group 10a, 10b. Each actuator has the same length, and the actuators 7a, 7b, . . . are arranged to face each other.

Note that the actuator groups described above are not limited to the two groups illustrated, but three or more groups can be arranged at equal angles.

The piezoelectric actuators 7a, 7b, . . .
It is a bimorph type, etc., which is constructed by pasting together piezoelectric elements 12a and 12b that expand and contract depending on the polarity of voltage applied to both sides of a substrate 11.When a voltage is applied with a predetermined polarity, it is distorted in one direction, and the voltage When the application of voltage is removed or a voltage of opposite polarity is applied, the piezoelectric actuators 7a, 7b, . . . are distorted in the opposite direction.

In addition, the piezoelectric actuators 7a, 7b, 8
a and 8b and 9a and 9b can respectively constitute the fixing part of the board 11 in common, and in this case,
The displacement portion of the piezoelectric actuator extends from the fixed portion toward the center at equal angles. When the substrate 11 has the above-described configuration, wiring to the substrate becomes easy.

On the other hand, the valve body 14 is connected to the valve member 15 and the valve member 15.
Seal members 16, 16 fitted to both longitudinal ends of
The free ends 17, . . . of the piezoelectric actuator are swingably locked in substantially V-shaped locking grooves 15a, . The valve body 14 is biased in the closing direction of the valve seat 3a by a return spring 18 compressed within the valve chamber 2.

The piezoelectric actuators 7a, 8a, and 9a in the piezoelectric actuator group 10a are connected in parallel to a power supply together with a resistor 20, as shown in FIG. , 22 are connected in series, so that the voltage applied to the piezoelectric actuators 9a, 8a, 7a is sequentially increased so that the amount of displacement becomes larger sequentially, and the piezoelectric actuators on the valve seat 4a side are The amount of displacement of the actuator 9a is set to be sufficient to close the valve seat 4a. On the other hand, each actuator of the piezoelectric actuator group 10b is also connected to the power source by a circuit similar to that shown in FIG. 3A, but as shown in FIG. 3B, each actuator 7
a, 7b, . . . can also be connected in parallel. Reference numerals 23 and 24 in FIGS. 3A and 3B are diodes and resistors provided in an attached circuit to promote discharge of the piezoelectric actuator.

Although not shown, the valve seats 3a, 4a
can be formed by a hollow screw member screwed onto the main body portions 1a, 1b, and in this case, the stroke of the valve body 14 can be adjusted by moving the screw member back and forth.

In the first embodiment, as shown in FIG. 1, in a state where the valve body 14 closes the valve seat 3a and opens the valve seat 4a, the piezoelectric actuators 7a, 7b,
When a voltage of a predetermined polarity is applied to . . . , the piezoelectric actuators 7a, 7b, . . .
Since the fitting portion with b is bent in one direction as a fixed portion, the valve body 10 opens the valve seat 3a and opens the valve seat 4a. Therefore, the pressure fluid from the inlet port 3 flows out from the outlet port 5.

In this case, a resistor 21 is provided in the power supply circuit of the piezoelectric actuators 8a and 8b, and a resistor 21 is provided in the power supply circuit of the piezoelectric actuators 8a and 8b.
Since the resistors 21 and 22 are connected in series to the power supply circuits a and 9b, the voltage applied to the piezoelectric actuator decreases toward the valve seat, and the amount of displacement increases from the piezoelectric actuators 9a and 9b to the piezoelectric actuators 7a and 7a, respectively.
It gradually increases toward 7b.

Therefore, even if there is some variation in the performance of each piezoelectric actuator, the actuators 8a, 8
b and 9a, 9b, actuators 7a, 7
valve seat 4a by b and 7a, 7b, 8a, 8b
Not only is a force acting in the direction of closing the actuators 7a, 7b, . . . the free ends 17, .
Since the piezoelectric actuators 7a, 7b, . . . are pivotally locked to the valve body 14, there is no interference between the acting forces of the actuators 7a, 7b, . . . and the acting forces of the plural piezoelectric actuators can be effectively utilized. Therefore, the valve body 14
Since the valve seat 4a is closed with a large force consisting of the sum of the acting forces of the piezoelectric actuators 7a, 7b, . . . , the usable range of flow rate and pressure can be dramatically expanded.

Furthermore, piezoelectric actuators 7a, 7b,...
Since the free ends 17, . .

FIG. 4 shows a second embodiment of the present invention, in which the valve body 2
The main body members 26a, 26b in 6 have opposing side walls made thicker in order toward the valve seat 4a, and piezoelectric actuators 7a, 7b, . As a result, the displacement length of the piezoelectric actuator is gradually shortened toward the valve seat 4a, and the displacement amount is gradually increased from the valve seat 4a side.

Other configurations and operations of the second embodiment include the resistor 2
Since it is the same as the first embodiment except that 1 and 22 are unnecessary, the same reference numerals are given in the drawings and detailed explanation will be omitted.

FIG. 5 shows a third embodiment of the present invention, in which the valve member 31 in the valve body 30 of the third embodiment is gradually enlarged in diameter toward the valve seat 4a, and a substantially V-shaped lock is formed at each enlarged diameter portion. Grooves 31a, 31b, 31c are formed, and the free ends of piezoelectric actuators 32a, 33b, which are hermetically fitted to the valve bodies 1a, 1b, are locked into the grooves 31a.
Then, the free ends of the actuators 33a, 33b are swingably locked in the locking groove 31b, and the free ends of the actuators 34a, 34b are rockably locked in the locking groove 31c, whereby the piezoelectric actuators 32a, 3
2b, . . . are gradually increased from the valve seat 4a toward the valve seat 3a, and the amount of displacement is gradually increased.

In the illustrated example, piezoelectric actuators 32a, 33a, 34a and 32b, 33b,
34b is sequentially shortened toward the valve seat 4a, but these actuators may be formed to have the same length and the lengths protruding outward from the main body members 1a, 1b may be sequentially increased. Even so, the displacement length of the piezoelectric actuator can be gradually increased from the valve seat 4a toward the valve seat 3a.

Other configurations and operations of the third embodiment include the resistor 2
Since it is the same as the first embodiment except that 1 and 22 are unnecessary, the same reference numerals are given in the drawings and detailed explanation will be omitted.

[Effect of idea]

The directional control valve of the present invention sequentially increases the displacement of a plurality of piezoelectric actuators arranged hierarchically in the valve seat closing direction from the valve seat side toward the opposite direction to the valve seat closing direction. The amount of displacement of the piezoelectric actuators on the seat side is sufficient to close the valve seat, and the free ends of these actuators are swingably locked to the valve body, so the acting force of each piezoelectric actuator can be used effectively. Moreover, by providing a plurality of these piezoelectric actuator groups, the sealing force of the valve body becomes stronger, and the usable range of flow rate and pressure can be dramatically expanded.

Furthermore, a plurality of piezoelectric actuator groups are installed at equal angles, and the free end of each piezoelectric actuator is swingably locked to the valve body, so the movement posture of the valve body is stable and the valve body is seated uniformly on the valve seat. Seal performance can be improved.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional front view of the first embodiment, and FIG. 2 is a plan view of the main parts of the same.
3A and 3B are circuit diagrams showing an example of power supply to the piezoelectric actuator of the first embodiment, FIG. 4 is a longitudinal sectional front view of the second embodiment, and FIG. 5 is a longitudinal sectional front view of the third embodiment. be. 1, 26... Valve body, 2... Valve chamber, 7a, 7
b, 8a, 8b, 9a, 9b...piezoelectric actuator, 10a, 10b...piezoelectric actuator group, 14, 30...valve body, 32a, 32b, 33
a, 33b, 34a, 34b...Piezoelectric actuator.

Claims (1)

[Scope of Claim for Utility Model Registration] A directional control valve in which a valve seat formed in a valve chamber of a valve body is opened and closed by a valve body provided on a piezoelectric actuator whose one end is fixed to the valve body, wherein the piezoelectric actuator is connected to the valve body. A plurality of piezoelectric actuators are arranged hierarchically in the opening/closing direction of the seat, and the amount of displacement of these piezoelectric actuators is increased sequentially from the valve seat side toward the direction opposite to the closing direction of the valve seat, and the amount of displacement of the piezoelectric actuator on the valve seat side is A plurality of piezoelectric actuator groups arranged hierarchically are arranged at substantially equal angles to the valve body, and the free ends of these piezoelectric actuators are swung to the valve body. A directional valve characterized in that it is capable of being locked.