JPH01176874A - Automatic gate valve - Google Patents

Abstract

PURPOSE:To protect a plunger from damage by providing a limit device for regulating the maximum advance position and the maximum retreat position of the plunger in a piezoelectric actuator. CONSTITUTION:Respective piezoelectric actuators A are provided with limit devices L1, L2 for limiting the maximum advance position and the maximum retreat position of the piezoelectric actuator A. When a plunger (d) advanced to the maximum advance position then tries to advance furthermore, a limit switch 42 functions to stop advancing operation of the piezoelectric actuator A immediately. When the plunger (d) retreats to the maximum retreat position then tries to retreat furthermore, a limit switch 51 functions to stop retreating operation of the piezoelectric actuator A immediately.

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 control the flow rate accurately. 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 Problems The present invention provides two flow passages on one side of the casing and one flow passage on the other side, and connects the flow passages on the one side to the flow passages on the other side. communicates with the passageway, and attaches a valve body to the communication part so that it can be opened and closed freely.
The present invention relates to an automatic opening/closing valve characterized in that both of the valve bodies can be driven by a piezoelectric actuator, and that the valve body is equipped with a limit device that regulates the maximum advanced position and the maximum retracted position of the plunger of the piezoelectric actuator.

(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-〇 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 limit device that regulates the maximum forward position and maximum retracted position of the plunger, so it can reliably prevent the plunger from advancing or retracting beyond the same position, thereby preventing damage or failure of the plunger. This can be prevented as much as possible.

(f) Examples The present invention will now be explained in detail based on examples shown in the accompanying drawings. Note that this embodiment shows a case where the automatic on-off valve according to the present invention is used as a hot water mixing faucet.

In FIG. 1, IO is a casing in the form of a cylindrical block, and the casing IO has a pair of one-side flow passages 11, 12 extending in parallel toward the inside on one end wall thereof. .

The one-side channels 11 and 12 function as the water supply channel and the hot water supply channel for the hot and cold mixer faucet, and their outer open ends 11a and 12a are connected to the water supply pipe 13 and the hot water supply pipe 1, respectively.
It communicates with 4.

On the other hand, the inner open ends 11b, 12 of the one side flow path 11.12
b communicate with compartments 15 and 16 formed at both ends of the casing 10, respectively.

Further, a T-shaped other side flow path 17 is formed in the other side end wall of the casing 10 .

The other side flow path 17 functions as a mixed water flow path of a hot and cold water mixing faucet, and its outer open end 17a communicates with the mixed water pipe 18, while its inner bifurcated frontage end 17b , 17c communicate with compartment 15.16.

Furthermore, the inner bifurcated opening end 17b of the other side flow path 17, 1
7c is provided with valve seats 20 and 21, respectively,
The valve seats 20 and 21 have an inner bifurcated open end 1 that moves forward and backward in the axial direction in the casing lO to come into contact with and separate from the valve seat 20.21.
Valve body 2 consisting of a diaphragm valve that opens and closes 7b and 17c
2.23 is installed.

Furthermore, piezoelectric actuators A are attached to both sides of the casing 10, respectively.

To attach each piezoelectric actuator A to the casing lO, actuator mounting spaces 32 and 33 are provided at the rear ends of the left and right actuator mounting blocks 30 and 31 provided on both side walls 10a and 10b of the casing 10, respectively. This is done by fitting the piezoelectric actuator A into the mounting space 32, 33 so as to be movable in the axial direction.

Furthermore, in this embodiment, each piezoelectric actuator A is
As shown in the figure and FIG. 2, the front and rear walls a.

In a cylindrical actuator casing C comprising b,
A valve rod 22a is provided at the tip of the plunger d, and a plunger d is attached concentrically and movably along the axis.
23a to actuator mounting block 30.31
The valve rods 22a and 23a extend through through holes 36 and 37 provided on the valve body side, and the tips of the valve rods 22a and 23a can freely come into contact with a pilot hole provided in the center of the valve body 22 and 23, and the outer periphery of the plunger d. Three piezoelectric elements e, concentrically arranged on the surface,
It is constructed by arranging a piezoelectric element assembly B consisting of r and g.

Furthermore, in the above configuration, 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 bring the plunger d into a non-clamped state, and expand when energized to clamp the plunger d. 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.

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. 2 and 3. Electrodes are attached to the outside as well as the inside where the ring contacts the plunger d, and the ring is configured to contract when a voltage is applied.

On the other hand, the piezoelectric element g, as shown in FIGS. 2 and 4,
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 when a voltage is applied to both ends. ing.

Note that piezoelectric ceramics can be used for the piezoelectric element pieces, for example, and such piezoelectric ceramics include A
PZT (Pb (Zr.

Tl) Os system, or PLZT (Pb (Zr, Ti)0
), PT (PbTiOi) system, and a three-component system based on PzT can be used.

Moreover, the piezoelectric elements e and f 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 laminating 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, the direction of voltage application is changed by 90 degrees.

Furthermore, h is a holder composed 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, (, g is always held between the actuator casing The piezoelectric element assembly B is elastically pressed toward the front wall a of C to maintain the relative position and to integrate the piezoelectric element assembly B.

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

In the above configuration, the piezoelectric elements e, f, and g may have not only a circular cross section but also a rectangular cross section, for example, and may be formed from divided pieces as shown in FIGS. 6 and 7. You can also do that.

The movement of the plunger d by the piezoelectric element assembly B will be explained below.

As shown in FIG. 8, the plunger d is clamped while leaving the piezoelectric element f as it is, and the voltage on the piezoelectric element e is released to contract it, thereby releasing the clamp on the plunger e.

Next, as shown in FIG. 9, 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. 10, when the voltage of the piezoelectric element f is released and the clamp of the plunger d is released, 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 24, 25, that is, the mixing ratio of the mixed water can be finely adjusted.

In this embodiment, each piezoelectric actuator A is provided with a limit device iL1. L2 is provided.

First, the configuration of the limit device L1 that regulates the maximum advance position will be explained. As shown in FIG.
Along the rear end of the actuator body a, an annular ring 40 is fixed onto the outer peripheral surface of the actuator body a with a connecting bolt 41.

Further, a limit switch 42 is provided on the outer peripheral surface of the actuator mounting block 30.31 at a location corresponding to the outer peripheral edge of the annular ring 40, and the tip of the limit switch 42 is connected to the annular ring 40. They are in contact with each other so that they can be freely approached and separated.

Further, a spring receiving plate 43 that is integral with the actuator mounting block 30.31 is provided at a position away from the rear end of the actuator mounting block 30.31.
There is a sprung IJ 7 between the annular ring 40 and the annular ring 40 described above.
4 is interposed. The annular ring 40 is always urged toward the limit switch 42 and brought into contact with each other.

With this configuration, when the plunger d advances to the maximum advanced position, that is, the position where the valve rods 22a and 23a come into contact with the valve bodies 22 and 23, and attempts to advance further, the piezoelectric actuator A is forced to retreat due to the reaction force. I will do it.

When the piezoelectric actuator A moves slightly backward, the annular ring 40 separates from the limit switch 42.
This activates the limit switch 42.

Then, the output is sent to a control unit (not shown), and the energization to the piezoelectric actuator A is stopped, so that the advancing operation to the piezoelectric actuator can be immediately stopped.

Next, the configuration of the limit device L2 that restricts the maximum retracted position of the plunger d will be explained.

The annular ring 40 has the base end of a limit switch mounting plate 50 extending parallel to and in the same direction as the axis of the piezoelectric actuator A mounted on its outer periphery. A switch 51 is attached.

On the other hand, the base end of a plunger 52 extending in the radial direction is fixed to the penetrating end of the plunger d that passes through the through hole provided in the rear wall C of the piezoelectric actuator A, and the tip thereof is connected to the limit switch 51 described above. They are located opposite each other.

With this configuration, when the plunger d retreats to the maximum retraction position, that is, the maximum opening position of the valve bodies 22 and 23, and attempts to retreat further, the kicker 52 comes into contact with the limit switch 51, and the limit switch 51 is activated. Then, the output is sent to a control unit (not shown), and the power supply to the piezoelectric actuator A is stopped, so that the backward movement of the piezoelectric actuator A can be immediately stopped.

If the control unit continues to apply voltage to the piezoelectric elements e and f based on the output of the limit switch 42 or 51, the plunger d is stopped and held at that position.

In FIG. 1, 60 is a temperature sensor provided in the other side flow path 17, which detects the temperature of the mixed water, feeds back the detected value to the control unit, and causes the control unit to automatically control the temperature based on the detected value. Both piezoelectric actuators A of the on-off valve are operated to control the appropriate temperature.

In addition, since the plunger d is clamped many times by the piezoelectric elements e, f, and g, it has a small coefficient of linear expansion, and has high hardness, strength, creep resistance, and wear resistance.
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 configuration will be specifically explained with reference to the case where it is used as a hot water mixing faucet.

That is, when the detected value from the temperature sensor 60 is fed back to the control unit and the control unit separately operates both piezoelectric actuators A of the automatic opening/closing valve based on the detected value,
The valve bodies 22 and 23 open and close at the set opening degree, and the one side flow path 11.
The amount of water supplied and the amount of hot water flowing from 12 to the other channel 17 can be mixed at a constant mixing ratio.

In this action, since the valve bodies 22 and 23 are actuated by the piezoelectric actuator A,
Flow rate control can be performed more reliably, and appropriate temperature control can be performed more reliably.

In addition, in this example, the automatic on-off valve was used as a hot water mixing faucet, but the automatic on-off valve can also be used for other purposes. For example, the automatic on-off valve can be used for other purposes. It can also be used when branching.

Further, a limit device ZL1.
Since it is equipped with L2, the plunger d can be moved beyond the same position.
It is possible to reliably prevent the advance or retreat of the

FIG. 11 shows another embodiment of the present invention.

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

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

This lining material has frictional force and wear resistance suitable for restraining the plunger d by f.

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

The spring receiving plate l is integrally connected to the plunger d, and the other spring receiving plate m 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 by the restoring force of the return spring S to the maximum forward position corresponding to the standby position, for example, to the position where the valve body 22, 23 is closed. Can be done.

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.

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

(2) Since the valve bodies 24 and 25 are configured to be able to be driven by the piezoelectric actuator A, the valve bodies 24 and 25 can be driven on the order of μm or sub μl depending on the number of times the voltage is applied.
can move forward and backward, allowing precise flow rate adjustment.

■Since the valve bodies 24 and 25 are configured to be able to be driven by the piezoelectric actuator A, the piezoelectric actuator A and the valve body 24
．． 25, there is no need to interpose a speed reduction mechanism between the automatic opening and closing valve, and the overall structure of the automatic opening/closing valve can be made extremely compact.

■Since it is equipped with limit devices LL and L2 that regulate the maximum advanced position and maximum retracted position of the plunger d of the piezoelectric actuator A, it is possible to reliably prevent the plunger d from advancing or retracting beyond the same position. Damage or failure of the plunger d can be prevented as much as possible.

[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, Fig. 2 is an enlarged explanatory view of the main parts, and Figs. 3 and 4 are Fig. 2 line 1-1 and ■-■ line. FIGS. 5 to 7 are cross sectional views of piezoelectric elements of other embodiments, and FIGS. 8 to 1
FIG. 0 is an explanatory diagram of the operating state of the piezoelectric actuator, and FIG. 11 is an enlarged explanatory diagram of the main part according to another embodiment of the present invention. In the figure, A: piezoelectric actuator B: piezoelectric element assembly Ll, L2: piezoelectric actuator 10: casing 13, one side passage 14; one side passage 20: other side passage 24: valve body
25X valve body Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 7 Fig. 5 Fig. 8 Fig. 11

Claims (1)

[Claims] 1. Two one-side channels (13) on one side of the casing (10)
) (14) and one other side flow path (
17), and one side flow path (13) (14) is connected to the other side flow path (13) (14).
17), and the valve bodies (22) and (23) are attached to the communication part so as to be openable and closable, and the valve bodies (22 and 23) are respectively driveable by the piezoelectric actuator (A), and the piezoelectric actuator (A) A limit device (L1) that regulates the maximum advance position and maximum retreat position of the plunger (d)
) (L2).