JPH01203777A - Automatic opening/closing valve - Google Patents

Abstract

PURPOSE:To correctly drive the plunger of a continuous drive type actuator for minute distance by forming a contracted diameter top edge part at the top edge of the plunger. CONSTITUTION:Onto one side wall 12b of a casing 10, a piezoelectric actuator A as a form of a continuous drive type actuator for minute distance is installed coaxially with a valve body 16, and the valve body 16 is opened and closed by driving said actuator A. A plunger (d) has a contracted diameter top edge part (q) at the top edge, and the edge surface area of said top edge part (q) is made markedly less than the sectional area of the plunger (d). Therefore, a thrust force which the plunger (d) receives can be minimized, and the piezoelectric actuator A can be correctly driven.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to an automatic on-off valve that controls fluid flow.

(B) Prior Art Conventionally, various types of automatic on-off valves are known, such as electromagnetic on-off valves using solenoids, electric valves driven by motors, and the like.

Such automatic opening/closing valves can be automatically operated using sensors and various switches.

(c) Problems to be solved by the invention However, since the drive source of such conventional automatic on-off valves is a solenoid or motor, it is not possible to perform highly accurate positioning, and it is difficult to precisely control the flow rate. could not.

An object of the present invention is to provide an automatic on-off valve that can solve the above problems.

(d) Means for solving the problem The present invention provides one side flow path on one side of the casing, and provides the other side flow path on the other side, and communicates the one side flow path with the other side flow path. , the valve body is attached to the communication part so that it can be opened and closed freely, and the valve body can be driven by a minute distance stepless drive type actuator, and the plunger of the actuator has a reduced diameter tip with a reduced pressure receiving area at the tip. This invention relates to an automatic on-off valve characterized by the following features.

In this case, the micro-distance stepless drive actuator refers to a stacked piezoelectric actuator, a piezoelectric bimorph actuator, a stamping linear motor, a piezoelectric linear motor, a combination of an ultrasonic motor (rotary type) and a rotating screw,
A combination of a stepping motor (rotary type) and a rotating screw.

(e) Actions and Effects With the configuration described above, the present invention has the following actions and effects.

(2) Since the valve body is configured to be able to be driven by a micro-distance stepless drive type actuator, the valve body can be moved forward and backward, for example, on the μm order or sub-μm order, and precise flow rate adjustment can be performed.

■Since the valve body is configured so that it can be driven by a micro-distance stepless drive type actuator, there is no need to interpose a speed reduction mechanism between the actuator and the valve body, and the overall structure of the automatic opening/closing valve can be made significantly more compact. can.

(2) Since a reduced diameter tip with a reduced pressure receiving area is formed at the tip of the plunger, the thrust force applied to the plunger can be made as small as possible, and the plunger can be driven accurately. Therefore, the automatic control valve can be driven more accurately and precisely.

(f) Examples The present invention will now be explained in detail based on examples shown in the accompanying drawings.

In FIG. 1, lO is a 5-shaped cylindrical casing that constitutes the main body of the automatic on-off valve C, and the casing 10 is
It is comprised of an inflow side pipe 12 that forms one side flow path 11 inside, and an outflow side pipe 14 that forms the other side flow path 13 inside.

The upper end of the inflow side pipe 12 is closed by an end wall 12a, and an opening 15 is formed in the one end side wall 12b.
A valve body 16 made of a diaphragm valve is attached to the opening 15.

On the other hand, the outflow side pipe 14 extends through the proximal cylindrical portion 14a to the opening 15, and its distal end abuts the valve body 16 so as to be movable toward and away from the valve body 16.

With this configuration, the inflow side pipe 1 is opened and closed by driving the piezoelectric actuator A, which will be described later, to open and close the valve body 16.
One side flow path 11 formed in the outflow side pipe 14 and the other side flow path 13 formed in the outflow side pipe 14 can be connected or disconnected from each other.

Note that the one side flow path 11 has its outer open end connected to the water supply pipe 17.
The other side channel 13 is in communication with the water pipe 18.

Further, a valve body 16 is provided on one side wall 12b of the casing 10.
A piezoelectric actuator A, which is one of the micro-distance stepless actuators, is installed coaxially with the actuator A, and by driving the actuator A, the valve body 16 can be opened and closed.

In this embodiment, as shown in FIG. 1, each piezoelectric actuator A has a plunger movable in a cylindrical actuator casing C having front and rear walls a and b, so that it can move back and forth concentrically and along its axis. d and the same plunger d.
The tip of the plunger d can freely come into contact with the rear part of the valve body 16, and a piezoelectric element assembly B consisting of four piezoelectric elements e+Lg+h is arranged concentrically on the outer peripheral surface of the plunger d. There is.

Furthermore, in the illustrated embodiment, the piezoelectric elements g and h are arranged in the center of the actuator casing C, and are fixed to the tip of a holder H whose base end is fixed to the actuator casing C.

Further, i and j are cantilever-like elastic bridges whose base ends are fixed to the piezoelectric elements g and h, and whose tips extend toward the front and rear walls a and b.

Piezoelectric actuators e and f are attached to the outer peripheral surfaces of the tips of the elastic bridges i and j, and l is fixed to the brake shoes on the inner peripheral surfaces thereof.

The piezoelectric elements e, f, g, and h are configured to contract when the power is turned off.

That is, when the piezoelectric element elf is energized, it expands and expands its inner diameter to unclamp the plunger d, and when it is not energized, it contracts and reduces its inner diameter to clamp the plunger d.

On the other hand, the piezoelectric elements g and h extend in the axial direction on the plunger d when energized, and when not energized, they contract in the axial direction on the plunger d, shortening the total length in the axial direction. become.

Then, the plunger d connects these four piezoelectric elements e+f
It is possible to move in the axial direction by controlling the voltage application procedure to +gJ by a control device C, which will be described later.

As shown in FIGS. 1 and 2, the piezoelectric elements e, f, g, and h are cylindrical elements formed by laminating a large number of piezoelectric element pieces in the axial direction of the plunger d. electrodes are provided at the , and by applying a voltage to both ends,
It is configured to stretch.

Note that the piezoelectric element piece can be made of, for example, piezoelectric ceramics, and examples of such piezoelectric ceramics include AB
PZT (Pb (Zr.

Tt)03) system, or PLZT (Pb (Zr, Ti)
03), PT (PbTiO3) system, or PZT
A three-component system based on can be used.

The piezoelectric element e+f t L h can also be formed by laminating a large number of thin ring-shaped piezoelectric element pieces in the axial direction around the axis of the plunger d, as shown in FIG. In this case, the direction of voltage application is changed by 90 degrees.

Further, in FIG. 1, m is a U seal with low sliding resistance, which is provided to improve the watertightness of the actuator A.

In the above configuration, the piezoelectric element "+LgJ" does not have only a circular cross section, but can also have a rectangular cross section, for example, and can also be formed from divided pieces as shown in FIGS. 4 and 5. .

In addition, since the plunger d is clamped to the brake shoe many times by l, it has a small linear expansion coefficient, high hardness, strength, creep resistance, and wear resistance, and has high processing accuracy. Desirably, for example, a ceramic material may be considered.

Furthermore, in this embodiment, the piezoelectric actuator A has a manual return button p attached to the center of the rear wall at a location facing the plunger d. When the manual return button p is pressed, its front surface projects forward and comes into contact with the rear end of the plunger d, pushing the plunger d forward against the clamping force of the piezoelectric elements e and f. be able to.

Therefore, when the plunger d stops with the valve part of the automatic on-off valve B open during a power outage, etc., the automatic on-off valve C can be completely closed by pressing the manual return button p immediately.

Furthermore, in this embodiment, the plunger d has a diameter-reduced tip q formed at its tip, and the tip q has an end surface area (pressure-receiving area) that is significantly smaller than the cross-sectional area of the plunger d. There is.

Note that an elastic body is attached to the tip of the diameter-reduced tip q.

Therefore, when used in a valve, etc., as described later, the pressure receiving area can be significantly reduced, so the thrust force applied to the plunger d can be minimized, and the influence of the thrust force on the drive of the plunger d can be minimized. This makes it possible to drive the piezoelectric actuator A accurately.

Furthermore, if the stepped portion of the plunger d is brought into contact with the rear surface of the front wall a when the plunger d has moved forward a certain distance (for example, at a fully closed position 1 or a position slightly further advanced than that), Further advancement of the plunger d can be restricted,
Damage to the diaphragm, etc. of the on-off valve due to excessive forward movement can be reliably prevented.

Further, FIG. 6 shows the configuration of a control device C for controlling the piezoelectric actuator A.

As shown, the control device C includes a microprocessor r
, input/output interfaces s and t, and the piezoelectric element e
It is composed of a memory U that stores a drive order program of 1f+Lh.

Next, the movement of the plunger d by the piezoelectric actuator A having such a configuration will be explained with reference to FIGS. 7 to 9.

As shown in FIG. 6, when the actuator drive button V is pressed, the control device C controls the piezoelectric element e according to the drive order program read out from the memory U, as shown in FIG.
The voltage applied to the piezoelectric element f is removed to reduce its inner diameter to clamp the plunger d, and a voltage is applied to the piezoelectric element f to enlarge its inner diameter to release the clamp on the plunger d.

Next, as shown in FIG. 8, when a voltage is applied to the piezoelectric elements g and h to extend them, the piezoelectric elements e and f move in the direction of the arrow.
Along with this, the plunger d clamped by the piezoelectric element e also moves in the direction of the arrow.

Thereafter, as shown in FIG. 9, when a voltage is applied to the piezoelectric element e to expand its inner diameter and the clamp of the plunger d is released, and when the voltage applied to the piezoelectric element g+FLO is released, the piezoelectric element g+11 moves in the direction of the arrow. , and the plunger d further extends in the direction of the arrow.

After that, by repeating the above operation, plunger d
can be moved in a linear manner with a stroke on the μm order or sub-μm order, and various devices and machines can be operated precisely.

In this embodiment, as described above, the plunger d of the piezoelectric actuator A has a reduced diameter tip q at its tip.
, the thrust force applied to the plunger d can be minimized, and the influence of the thrust force on the drive of the plunger d can be minimized, making it possible to accurately drive the piezoelectric actuator A. .

Next, the automatic opening/closing valve having the above configuration is operated by the first
This will be explained with reference to the figures.

That is, when a desired control section or operation section is activated to operate the piezoelectric actuator A of the automatic opening/closing valve, the valve body 16 opens and closes at the set opening degree, and the flow from one side flow path 11 to the other side flow path 13 is performed. Fluid will flow at the set flow rate.

In this embodiment, since the valve body 16 is operated by the piezoelectric actuator A, the flow rate can be controlled reliably and precisely.

Furthermore, in this embodiment, as described above, the plunger d of the piezoelectric actuator A has the diameter-reduced tip q formed at its tip, so that the piezoelectric actuator A can be driven accurately and the flow rate can be further controlled. It can be done reliably and precisely.

As described above, this embodiment has the following functions and effects.

■Since the valve body 20 is configured to be driven by the piezoelectric actuator A, the valve body 20 can be moved forward or backward on the μm order or sub-μm order depending on the number of voltage applications, making it possible to perform precise flow rate adjustment. can.

■Since the valve body 20 is configured to be driven by the piezoelectric actuator A, there is no need to interpose a speed reduction mechanism between the actuator A and the valve body 20 (and the overall structure of the automatic opening/closing valve can be made extremely compact). can.

■Plunger d of piezoelectric actuator A has a diameter-reduced tip p at its tip, so the pressure-receiving area that receives water pressure etc. can be reduced, enabling accurate drive of piezoelectric actuator A, and more reliable flow control. And it can be done precisely.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing the internal structure of an automatic on-off valve according to the present invention, FIG. 2 is a cross-sectional view taken along line II in FIG. 1, and FIGS. 3 to 5 are piezoelectric elements according to other embodiments. Cross-sectional view of, No. 6
The figure is an explanatory diagram of the configuration of the control device, and Figures 7 to 9 are the operating states of the piezoelectric actuator! :, is an explanatory diagram. In the figure, A: Piezoelectric actuator B: Piezoelectric element assembly C: Automatic opening/closing valve 10: Casing 11 Knee side flow path 13: Other side flow path 16: Valve body d Ni plunger q: Diameter reducing tip Patent applicant Toto Kiki Co., Ltd.

Claims (1)

[Claims] 1. One side flow path (11) is provided on one side of the casing (10), and the other side flow path (13) is provided on the other side, and the one side flow path (11) is communicated with the other side flow path (13). A valve body (16) is attached to the communication portion so as to be openable and closable, and the valve body (16) can be driven by a minute distance stepless drive type actuator.
And at the tip of the plunger (d) of the actuator,
An automatic on-off valve characterized by having a reduced diameter tip (q) with a reduced pressure receiving area.