JPH0193679A - Automatic opening/closing valve - Google Patents

Abstract

PURPOSE:To eliminate precision flow control and a retardation mechanism, and miniaturize the valve by enabling a valve disc to be driven by means of a piezoelectric actuator. CONSTITUTION:A one side passage 12 is provided on one side of a casing 10, an other side passage 17 being provided on the other side of the casing. A valve disc 20 is installed in the connection area of these passages 12, 17 so that it can be freely opened and closed with respect to the connections, and the valve disc 20 can be driven by a piezoelectric actuator A. A control unit or an operating unit operates the piezoelectric actuator A to open and close the valve disc 20 at a preset opening, and thus a preset flow of fluid flows from the one side passage 12 to the the other side passage 17.

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. I can't do it.

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. This invention relates to an automatic opening/closing valve characterized in that a valve body is attached to the communication portion so as to be openable and closable, and the valve body can be driven by a piezoelectric actuator.

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

■Since the valve body is configured so that it can be driven by a piezoelectric actuator, the valve body can be advanced or retreated on the order of μ division or μ increase depending on the number of voltage applications, making it possible to precisely adjust the flow rate. can.

(2) Since the valve body is configured to be driven by a piezoelectric 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 extremely compact.

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

In FIG. 1, reference numeral 10 denotes a casing in the form of a cylindrical box, and the casing 10 has an L-shaped cylindrical body 11 with openings at both ends protruding from one side wall on one end side of the casing 10. An L-shaped one-side flow path 12 is formed.

The one-side flow path 12 has its outer open end 12 a communicating with the water supply pipe 13 .

On the other hand, the inner open end 12b of the one-side flow path 12 communicates with a compartment 14 formed at one end of the casing 10.

Further, on the other side wall of the casing 10, an L-shaped cylindrical body 15 with both ends open is protruded approximately symmetrically through a partition wall 16, and inside the L-shaped cylindrical body 15, an L-shaped cylindrical body 15 is provided. The other side flow path 17 is formed.

The other side flow path 17 has an outer opening end 17a.
communicates with the mixed water pipe 18, while its inner open end 17b communicates with the compartment 14.

Further, a valve seat '1 is provided at the inner opening of the L-shaped cylinder 15.
9 is provided, and the valve seat 19 is provided with a casing 10
A valve element 20 is provided which is a diaphragm valve that moves forward and backward in the axial direction to come into contact with and separate from the valve seat 19 to open and close the inner opening end 17b.

Furthermore, a piezoelectric actuator A is attached to the other end of the casing 10.

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 2o can freely come into contact with the rear part of the valve body 2o, and three piezoelectric elements e and f are arranged concentrically on the outer peripheral surface of the plunger d.

It is constructed by arranging a piezoelectric element assembly B consisting of g.

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

That is, the piezoelectric elements e and f extend and clamp the plunger d when not energized, and contract and release the plunger d when energized. - side, piezoelectric element g
is extended in the axial direction on the plunger d when it is not energized, and when it is energized, it contracts on the plunger d, shortening its total length in the axial direction.

The plunger d then connects these three piezoelectric elements e and f.
, g can be appropriately controlled to move in the axial direction.

As shown in FIGS. 1 and 2, the piezoelectric elements e and f are ring-shaped elements formed by laminating a large number of piezoelectric element pieces concentrically around the axis of the plunger d, and the ring is attached to the plunger d. Electrodes are attached to the outside as well as the inside in contact with d, and the ring is configured to contract when a voltage is applied.

Moreover, as shown in FIGS. 1 and 3, the piezoelectric element g is
It is a cylindrical element formed by laminating a large number of piezoelectric element pieces at right angles to the axis of the plunger d. Electrodes are provided at both ends of the cylinder, and it is configured to contract by applying a voltage to both ends. ing.

Furthermore, h is an elastic body such as a disc spring interposed between the rear end of the piezoelectric element g and the rear wall, and the piezoelectric element e.

The piezoelectric element assembly B is integrated by always elastically pressing f and g toward the front wall a.

Note that in the above configuration, piezoelectric elements e, r, g
has not only a circular cross section (for example, it can also have a rectangular cross section, etc.), and can also be composed of divided pieces shown in FIGS. 4 and 5.

The movement of the plunger d by the piezoelectric element assembly B will be explained below with reference to FIGS. 6 to 8.

As shown in FIG. 6, the plunger d is clamped while leaving the piezoelectric element f as it is, and a voltage is applied to the piezoelectric element e to contract it, thereby releasing the clamp on the plunger d.

Next, as shown in FIG. 7, when a voltage is applied to the piezoelectric element g to contract it, the piezoelectric element f moves in the direction of the arrow, and the plunger d, which the piezoelectric element f clamps, also moves in the same direction. do.

Thereafter, as shown in FIG. 8, when a voltage is applied to the piezoelectric element f to release the clamp of the plunger d and at the same time the voltage applied to the piezoelectric element g is released, the piezoelectric element g extends in the direction of the arrow, and the piezoelectric element f also extends in the same direction.

After that, by repeating the above operation, plunger d
can be moved gradually with a stroke on the μm order or sub-μm order, and the opening/closing amount of the valve body 20, that is, the flow rate can be finely adjusted.

Further, in FIG. 1, reference numerals 21 and 22 indicate U seals provided to improve the watertightness of the piezoelectric actuator A.

In addition, since the plunger d is clamped many times by the piezoelectric element e+'+g, the linear expansion coefficient is small (hardness, strength, creep resistance and wear resistance are large,
Furthermore, it is desirable to have a material with high processing accuracy, and for example, a material made of a ceramic material can be considered.

Next, the operation of the automatic on-off valve having the above structure will be explained with reference to FIG.

That is, when a desired control section or operation section is actuated to operate the piezoelectric actuator A of the automatic opening/closing valve, the valve body 20 opens and closes at the set opening degree, and the flow path 12 from one side flows to the other side flow path 17. Fluid will flow at the set flow rate.

In this embodiment, since the valve body 20 is operated by the piezoelectric actuator A, the flow rate can be controlled more reliably and precisely.

As described above, the invention according to 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. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view showing the internal structure of the automatic on-off valve according to the present invention, and FIGS. 2 and 3 are line I-■ and n-n in FIG.
4 and 5 are cross-sectional views of piezoelectric elements according to other embodiments, and FIGS. 6 to 8 are diagrams illustrating operating states of the piezoelectric actuator. In the figure, A: piezoelectric actuator B: piezoelectric element assembly 10: casing 12 knee side passage 17: other side passage 20: valve body Fig. 1 Fig. 7

Claims (1)

[Claims] 1. One side flow path (12) is provided on one side of the casing (10), and the other side flow path (17) is provided on the other side, and the one side flow path (12) is communicated with the other side flow path (17). An automatic opening/closing valve characterized in that a valve body (20) is attached to the communication portion so as to be openable and closable, and the valve body (20) can be driven by a piezoelectric actuator (A).