JPH01176872A - Automatic gate valve - Google Patents

Abstract

PURPOSE:To perform precise flow regulation by fixing a spring for resetting a plunger to a waiting position when it is not clamped to a piezoelectric actuator. CONSTITUTION:When power is not supplied, piezoelectric elements (e), (f) contract to bring a plunger (d) into non-clamped state, while when power is supplied, they elongate to clamp the plunger (d). When power is supplied, a piezoelectric element (g) contracts above the plunger (d) and shorten the overall length thereof in axial direction. The plunger (d) can move in the axial direction when three piezoelectric elements (e), (f), (g) are controlled properly. A piezoelectric actuator A comprises a spring S for resetting the non-clamped plunger (d) to a waiting position.

Description

[Detailed description of the invention] (b) Industrial application fields 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. , a valve body is attached to the communication portion so as to be openable and closable, the valve body can be driven by a piezoelectric actuator, and a return spring is attached to the piezoelectric actuator to return the plunger to the standby position when it is not clamped. This relates to a characteristic automatic on-off valve.

(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 driven by a piezoelectric actuator, the valve body can be advanced or retreated on the μm order or subμ-order depending on the number of voltage applications, allowing precise flow rate adjustment.

(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.

■The piezoelectric actuator is equipped with a return spring that returns the unclamped plunger to the standby position, so in the event of a power outage, for example, the return spring can easily return the unclamped plunger to the valve fully closed position. It can be moved by force to completely close the valve to ensure that no fluid flows out or leaks.
-(f) Examples The present invention will be explained in detail below based on the examples shown in the attached 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 of the casing 10. An L-shaped i-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, a single-shaped cylinder 15 with openings at both ends protrudes approximately symmetrically through a partition wall 16, and inside the same cylinder 15, an L-shaped cylinder 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 19 is provided at the inner opening of the single-shaped cylindrical body 15, and the valve seat 19 moves back and forth in the axial direction within the casing 10 to come into contact with and separate from the valve seat 19. edge 17
A valve body 20 consisting of a diaphragm valve that opens and closes b is disposed.

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 can be freely advanced and retreated concentrically and along the axis within a cylindrical actuator casing C having front and rear walls a and b. Install plunger d, and
The tip of the plunger 20 can freely come into contact with the rear part of the valve body 20, 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 off.

That is, the piezoelectric elements e and f contract when not energized to put the plunger d in a non-clamped state, and extend and clamp the plunger d when energized. On the other hand, when the piezoelectric element g is not energized, it extends in the axial direction on the plunger d, 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.

In addition, the piezoelectric elements e and f are ring-shaped elements formed by stacking a large number of piezoelectric element pieces concentrically around the axis of the plunger d, as shown in FIGS. 1 and 2. Electrodes are attached to the outside as well as the inside where the ring contacts the plunger d, and the ring is configured to expand 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 layering many piezoelectric element pieces with Mi layered 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. has been done.

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.O) is a ferroelectric material with a perovskite crystal structure.

Ti)O, system, or PLZT (Pb (Zr, Ti)0
*), a PT (PbT i Os ) system, or a three-component system based on PZT can be used.

Moreover, the piezoelectric elements e and r 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 will be changed by 90 degrees.

On the other hand, the piezoelectric element g can also be formed by stacking a large number of elongated thin-walled cylindrical piezoelectric element pieces concentrically around the plunger d, as shown in FIG.

Note that in this case as well, the direction of voltage application is changed by 90 degrees.

Further, h is a holder made of an elastic body such as a disc spring, which is interposed between the rear end of the piezoelectric element g and the rear wall, and the end face of the piezoelectric elements e, f, and g is always kept close to the actuator casing C. It is intended to be elastically pressed toward the front wall a to maintain the relative position and to integrate the piezoelectric element assembly B.

In addition, in FIG. 1, i and j are piezoelectric actuator A
This is a U-packet installed to improve watertightness.

In addition, k is a spring storage chamber provided at the back of the rear wall C of the actuator casing a, and the storage chamber contains:
Return spring receiving plate 1. m is arranged.

The spring receiving plate 1 on one side is integrally connected to the plunger d, and the spring receiving plate m on the other side is integrally connected to a screw punch 0 screwed onto the auxiliary wall n.

With this configuration, when the plunger d is in the unclamped state, the plunger d can be extended to the maximum forward position corresponding to the standby position by the restoring force of the return spring S.

In addition, the restoring force of the return spring S is applied by rotating the screw punch 0 to both spring receiving plates 1. This can be easily done by adjusting the interval between m.

Note that in the above configuration, piezoelectric elements e, f, g
can have not only a circular cross section but also a rectangular cross section, for example, and can also be composed of divided pieces as shown in FIGS. 5 and 6.

The movement of the plunger d by the piezoelectric element assembly B will be explained below with reference to FIGS. 7 to 10.

As shown in FIG. 7, the plunger d is clamped while leaving the piezoelectric element r 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. 8, 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. 9, when a voltage is applied to the piezoelectric element f to release the clamp on the plunger d and the voltage applied to the piezoelectric element g is also 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 in a linear manner 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.

Moreover, since the piezoelectric actuator A is equipped with a return spring S that returns the plunger d in the unclamped state to the standby position, for example, in the event of a power outage, the plunger d in the unclamped state can be moved as shown in FIG. can be easily returned to the standby position.

In addition, since the plunger d is clamped many times by the piezoelectric elements e, f, and H, the linear expansion coefficient is small, and the 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.

In addition, in the event of a power outage, even if the plunger d becomes unclamped, the return spring S will easily move the plunger d to the valve closing position, completely closing the valve and preventing leakage accidents. can do.

FIG. 11 shows another embodiment of the present invention.

In this figure, piezoelectric elements e, f, and g are held by a holding body at the center of g to maintain their relative positions in the actuator casing C.

t is a bridge portion that elastically connects the piezoelectric elements e and f with the piezoelectric element g, and U is the piezoelectric element e.

Pi! suitable for restraining during plunge by f! Friction force,
It is a lining material with wear resistance.

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 subμ-order depending on the number of voltage applications, allowing precise flow rate adjustment. Can be done.

■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. .

■Since the piezoelectric actuator A is equipped with a return spring S that returns the unclamped plunger d to the standby position, for example, in the event of a power outage, the unclamped plunger d can be easily brought to the valve completely closed position. It is moved by the restoring force of the return spring S to completely close the valve, thereby reliably preventing outflow or leakage of fluid.

[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 lines I-■ and ■-■ in FIG.
4 to 6 are cross sectional views of piezoelectric elements according to other embodiments, FIGS. 7 to 10 are illustrations of operating states of the piezoelectric actuator, and FIG. 11 is a cross sectional view of a piezoelectric element according to another embodiment. FIG. 7 is a cross-sectional side view showing the internal structure of another embodiment of such an automatic on-off valve. In the figure, A: piezoelectric actuator B = piezoelectric element assembly S: return spring 10: casing 12 knee side flow path 17: other side flow path 20: valve body patent applicant Totoki Co., Ltd.

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). 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), and a plunger (d) is attached to the piezoelectric actuator (A). An automatic opening/closing valve characterized by being equipped with a return spring (S) that returns to the standby position when clamped.