JPS6014954B2 - Fluid control method and device using piezoelectric elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid control method and apparatus that use piezoelectric elements to enable high-speed and reliable switching.

Conventionally, electromagnetic drive using a solenoid has been used to drive a fluid control valve using an electric signal. However, in the case of solenoid drive, the driving force is determined by the ampere turns of the coil, so in order to obtain high output it is necessary to increase the number of turns of the coil or increase the current value. However, these methods have problems such as decreased response due to increased inductance and coil burnout due to Joule heat. Therefore, if you try to obtain a high-speed valve using a solenoid drive method for the follower, you will inevitably have to send a large fin flow through a coil with a small number of turns, and there are many practical constraints, so there is a limit to the response speed. In the case of a solenoid, a holding current flows while the driving force is being held, which also causes heat generation, but it is also efficient in that it consumes energy even when it is not doing external work. I also didn't like it. One way to supplement the solenoid drive method described above is to make the control valve a two-stage amplification type and use a solenoid to drive the pilot stage to reduce the load on the solenoid.
There are methods to increase the speed, but even in this case, it is not possible to eliminate the transmission delay between the pilot and the main valve, and there is a limit to the response speed, especially when the main valve has a large capacity. The present invention corrects the above-mentioned drawbacks of the conventional example by using a laminated type Shoden driver that expands and contracts by utilizing the dew distortion effect of a piezoelectric element, and enables high-speed and high-precision switching of the fluid. This was created for the purpose of providing a control valve, in which a voltage is applied to the actuating body with the large cross-sectional area of the actuating body with the large cross-sectional area and the actuated body with the small cross-sectional area to a driver using a piezoelectric element and replacing the displacement of the piezoelectric element with the amplified displacement of the actuated body with a small cross-sectional area based on the continuity of the fluid sealed between the actuation body and the actuated body, By the amplified displacement, the two-way seat surface is opened, and then the applied voltage of the piezoelectric agitator is released, and the seat surface is closed by the elastic force of the elastic body provided in the valve body. It is.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention, and the figure shows a laminated piezoelectric separation device.

The pressure crab driver 12 also includes an appropriate number of laminated ceramic electric elements, positive electrode plates and negative electrode plates inserted alternately between the piezoelectric elements, a protective casing for insulation, and a driven part flange. The driven end flange 2 is formed to be able to move in the order of several low by applying a pressure of 1,500 to 2,000 y. A large-diameter piston, which is housed in a cylinder with a casing and can slide inside the cylinder, is provided in contact with the lower part of the driven end flange 2, and the large-diameter piston 4 At the bottom, there is a back of a large chamber that is sealed with a suitable fluid such as oil.

Large chamber 5 has a lotus passage through chamber 4 and chamber 6.
At the bottom of the chamber 6, a piston 1 is arranged so as to be able to slide inside the cylinder.

A valve body 8 is attached to the lower part of the small diameter piston 7. The valve body 8 is provided with a guide part 9 having a relatively large diameter and capable of sliding inside the casing 3 at its upper part, and a valve body 11 having two seats 8 at its lower part. .

An oil passage 13 is provided on the casing 3 side between the guide portion 9 and the valve body 11, and the oil passage 13 that fits the oil passage turtle 2 is provided, and when the valve body Kametomi moves downward, the seat surface turtle 0 is separated from the valve seat 4, allowing high-pressure fluid to flow out through the oil passage 15 and turtle 6. Further, the valve body 8 is supported by a spring turtle 7, and is pushed up by the spring 17 when the applied voltage of the laminated piezoelectric drive device 1 is released, so that the oil passage stove 2 and the oil machine turtle 5 can be cut off. It is formed like this. When a high voltage is applied to the laminated piezoelectric actuator, the piezoelectric element expands in accordance with the voltage, and the flange 2 at the end of the piezoelectric element moves downward by the total amount of elongation of each piezoelectric element. The fluid sealed in the large chamber 5 flows into the chamber 4 and pushes the small piston 7 downward by the amount of movement of the end flange 2.

The amount of movement of the small-diameter piston 7 is the cross-sectional area of the large-diameter piston turtle. It will be amplified.

When the small-diameter piston) moves downward, the valve body 8 also moves downward, and the seat surface 88 separates from the valve seat mechanism. ] Honey,
The oil flows from j5 to the outside through the oil passageway 6, and operates a predetermined driven object.

When the application of the laminated piezoelectric agitator turtle is released, the piezoelectric element shortens and returns to its original position.On the other hand, the valve body crab is pushed up by the spring 171, so it rises and returns to its original position. At this time, a part of the fluid in the small chamber 6 also flows back into the large chamber 5. FIG.
This is an example, which is a more specific version of the one shown in FIG.

In this embodiment, the laminated type piezoelectric driver is housed in a casing 18, and a lid is placed over its upper end so that it can receive the reaction force generated by the operation of the piezoelectric driver. is formed.

In addition, the large diameter piston W is fitted with iron so that it can slide inside the large diameter cylinder 2Q mounted on the casing 3.
In the military there is a sliding iron fitting.

An oil passage 35 provided with a check valve 3 having a spring 33 is connected to an oil channel 35 provided on the side of the small diameter cylinder 21, and the sealed fluid in the small chamber 6 and the large chamber fleas is If the fluid leaks to the outside for some reason and the fluid in these chambers 6, 5 becomes less than a predetermined amount, the fluid sent from the auxiliary fluid pressure line is sent to the small chamber through the oil passages 35, 22. It is formed so that it can be replenished within 6.

The check valve 34 is for preventing the fluid in the large and small chambers 6, 6 from leaking to the oil path 35 side. The valve body 8 located at the lower part of the small diameter piston 7 has a straight-shaped guide part 9 at its upper part and is in slidable contact with the inner wall of the casing 3, but its lower part has a tapered shape that becomes narrower as it goes downward. The lower end thereof is connected to the horizontal portion of the valve body 11 with an appropriate curvature, and a ring-shaped seat surface 10 is provided at the outer peripheral end.

Further, a ring-shaped valve seat body 23 having a valve seat 14 in contact with the seat surface 10 of the valve body 11 is attached to the upper end of the oil passage 15 .

Then, due to the space surrounded by the tapered part of the valve body 8, the curved part, the horizontal part of the valve body 11, the inner wall of the ring-shaped seat surface 10, etc., water is ejected from the seat surface 10 toward the oil passage 15 side. The momentum vector becomes close to perpendicular to the axial direction, and as a result, the fluid reaction force in the fly line direction (so-called Bernoulli fluid reaction force) applied to the valve body 8 becomes close to zero. The valve element 11 is formed in a somewhat elongated cylindrical shape, and a spring 17 is inserted into the hollow part of the valve element 11. The upper end of the valve body 17 is in contact with the wall of the valve body, and its lower part is in contact with the casing 25.A valve body guide 26 is attached to the central projection of the casing 25, and the valve body guide 26 of the valve body 8 is in contact with the valve body wall. The outer circumferential cylindrical part of the tortoiseshell is adhered to the central hollow part of the valve body guide 26 so as to be movable.

The upper part of the valve body guide 26 has a tapered shape that becomes narrower as it goes upward.
Iron is attached to the tapered hole. Furthermore, the flange portion of the valve body guide 26 is fixed to the casing 3 via bolts. The valve body guide 26 is provided with an appropriate number of through holes 24 that are connected to the oil passage 15, and the lower ends of the through holes 24 are connected to the gap 27 provided between the valve body guide 26 and the casing 25. ing.

Note that in the figure, 13 is an oil passage communicating with the oil passage 12, and 16 is an oil passage that sends fluid to the outside.

When a high voltage is applied to the piezoelectric driver 1, the large-diameter piston 4 moves downward due to the expansion of the piezoelectric element, and pushes out the compressed fluid in the large chamber 5 into the small chamber 6.

Then, the small diameter piston 7 is amplified and moves downward,
Accordingly, the valve body 8 also moves downward, causing the seat surface 10 of the valve body 11 to separate from the valve seat 14 of the valve seat body 23, and the seat surface 10 to move downward.
A predetermined gap is created between the valve seat 14 and the oil passages 12 and 1.
5 is far away. When oil passage 12 and oil passage 15 pass through each other,
The high pressure fluid sent into the oil passages 13 and 12 flows into the oil passage 15, passes through the oil passage 16 from the oil passage 15, and is sent to the driven object side.

When high-pressure fluid flows from the oil passage 12 to the oil passage 15, the momentum vector of the fluid ejected from the seat surface 10 to the outer periphery of the valve body 11 becomes close to perpendicular to the axis, and as a result, the fluid applied to the valve body 8 in the direction of the The reaction force becomes close to zero. The pressure of the fluid that has entered the oil passage 15 is transmitted to the gap 27 through the through hole 24 of the valve body guide 26, and a force that pushes the valve body guide 26 upward is applied to the tapered portion of the valve body guide 26. Therefore, since the valve body guide 26 hardly moves, there is no misalignment or wobble when guiding the valve body 8.

When the voltage application to the piezoelectric driver 1 is released, the spring 1
7 is pushed up by the valve body 8, the seat surface 10 and the valve seat 14 come into contact, and the oil passages 12 and 15 are closed. The small diameter piston 7 is also pushed upward by the valve body 8, and a portion of the fluid in the small chamber 6 returns to the large chamber 5. FIG. 3 shows an example of the fluid control valve shown in FIG. 2 in which a check valve is provided in the oil passage for supplying fluid to the large chamber and the small chamber within the small diameter cylinder.

Even with such a configuration, leakage of fluid to the outside can be effectively prevented. In the drawing, 36 is a ball, 37 is a set screw, and the same reference numerals as those shown in FIG. 2 indicate the same parts. FIG. 4 shows an example in which the large chamber and the small chamber are formed by forming a large metal bellows 29 and a small bellows 30, and the small diameter piston 7 is housed in the small diameter bellows 38. There is.

The lower end of the small diameter bellows 38 is attached to the guide 31 in a sealed state so that the fluid in the small chamber 6 does not leak to the outside, and the upper end of the small diameter bellows 30 covers the small diameter piston 7. The upper end of the large bellows 29 is attached to the large diameter piston 4, and the lower end thereof is attached to the guide 31 to prevent fluid leakage.Even with this configuration, the small diameter piston 7 is amplified by driving the piezoelectric driver 1. It is possible to completely prevent the fluid in the large chamber 5 and the small chamber 6 from leaking to the outside.In addition, the same reference numerals as those shown in FIG. Figure 5 shows a diaphragm 3 at the bottom of the large piston 4.
This is an example in which a small diameter piston 7 is covered with a small diameter bellows 30 to form a large chamber 5 and a small chamber 6, as in the case of FIG.

Even with such a configuration, the small diameter piston 7 can be amplified and moved, and leakage of the fluid in the large chamber 5 and small chamber 6 can be completely prevented in the same manner as shown in FIG. In the drawings, the same reference numerals as those shown in FIGS. 2 and 5 indicate the same components. In the embodiments of the present invention, the case where the fluid control valve is used as a 20,000 valve has been described, but it is also possible to arrange two units in parallel and use it as a three-way valve, and other modifications may be made without departing from the gist of the present invention. Of course, various changes may be made.

A fluid control method and device using a Shoelectric element of the present invention amplifies and operates an actuated body with a small cross-sectional area through a sealed fluid by an actuating body with a large cross-sectional area operated by a piezoelectric driver. , this amplification action opens the valve body,
Furthermore, since the valve body is closed by the elastic force of the elastic body, an excellent effect can be achieved in that the valve body can be switched at high speed and with high precision.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a first embodiment of the fluid control method and device using a piezoelectric element of the present invention, and FIG. 2 is a second embodiment of the fluid control method and device using a piezoelectric element of the present invention. An explanatory diagram of an example: ``Figure 3 is an explanatory diagram when the check valve of the fluid control valve of the second embodiment is installed on a small diameter piston.'' Figure 4 is an explanatory diagram of the case where the check valve of the fluid control valve of the second embodiment is installed on a small diameter piston. Figure 5 is an explanatory diagram when a diaphragm is provided in the large chamber, and a metal bellows is provided in the chamber 4. 1 is a piezoelectric drive, 4 is a large piston, and 5 is a large chamber
6 is the small chamber, 7 is the 4-piston, 8 is the valve body,
10 is a seat surface, 12, 13, 15, 16 are oil passages, 14
'Ma valve seat, 17 indicates a spring. Murasaki - Tsutomu 3 Figure 2 Figure 4 Festival S Figure

Claims (1)

[Scope of Claims] 1. Among an actuating body with a large cross-sectional area and an actuated body with a small cross-sectional area, the actuating body with a large cross-sectional area is driven by applying a voltage to a driver using a piezoelectric element, and The displacement of the piezoelectric element is replaced by the amplified displacement of the actuated body with a small cross-sectional area based on the continuity of the fluid sealed between the actuation body and the actuated body, and by the amplified displacement, A fluid control method using a piezoelectric element, characterized in that the two-way seat surface is opened, then the applied voltage of the piezoelectric driver is released, and the seat surface is closed by the elastic force of an elastic body provided in the valve body. . 2. A fluid-sealed chamber is provided between an actuating body with a large cross-sectional area and an actuated body with a small cross-sectional area, which are actuated by a piezoelectric driver, and a chamber is provided on the side opposite to the chamber of the actuated body, and which contacts the valve seat when closed. Providing a valve body that separates from the valve seat when opening,
A fluid control device using a piezoelectric element, characterized in that the valve body is provided with an elastic body that closes the valve body when the voltage applied to the piezoelectric driver is released.