JPH0326300B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a fluid control valve for flow rate adjustment applied to combustion equipment using fluid fuel such as gas or oil, or to a control mechanism using air pressure. .

BACKGROUND OF THE INVENTION A control valve that continuously changes a fluid flow rate using an electric signal is used, for example, in an instantaneous water heater that controls the amount of heat generated by combustion and stabilizes the temperature of hot water. An example is shown in FIG. (Jikko 59-18216
In this system, a valve body 4 is provided at the lower end of a plunger 3 in which the center of a coil 1 is supported by a leaf spring 2, and the opening degree of a valve hole 6 formed in a gas passage 5 is adjusted. As the coil current increases, the plunger 3 is attracted upward and the valve opening becomes larger, making it possible to control the gas amount using the current value. In this configuration, since the position of the plunger 3 is continuously varied, a condition is satisfied in which the attractive force of the plunger 3 and the reaction force of the leaf spring 2 are balanced, resulting in a magnetic circuit with many magnetic gaps. Therefore, there is a problem in that a large amount of current is required to be supplied to the coil, and the capacity of the drive power source is inevitably increased. Next, FIG. 4 shows an example in which a piezoelectric element is used as a driving source. (Unexamined Japanese Patent Publication No. 60-4682)
This connects the two piezoelectric elements 7 and 8 with spacers 9 at both ends.
The amount of displacement is expanded by connecting with
The opening degree of a valve hole 12 provided in a passage 11 is adjusted by a valve body 10 interlocking with the center of a lower piezoelectric element 8. Since the amount of deformation changes depending on the applied voltage, the valve opening can be adjusted by voltage control, and power consumption is minimal. In this configuration, the valve part and the drive part are formed separately, and in order to eliminate external leakage of fluid, it is necessary to provide an airtight seal at the valve body 10 or to make the storage part of the drive part a sealed structure. The former causes hysteresis due to lack of smoothness of operation, and the latter causes structural complexity.

Problems to be Solved by the Invention As mentioned above, the conventional examples have problems such as high power consumption or structural complexity. The purpose is to obtain a control valve.

Means for Solving the Problems In order to solve the above problems, the fluid control valve of the present invention includes a disc-shaped piezoelectric element, an inlet hole formed corresponding to the central flat surface of the disc-shaped piezoelectric element, and a valve housing having an outlet hole; a sealing means for airtightly sealing between the valve housing and the peripheral edge of the disc-shaped piezoelectric element;
It is constructed from a holding means that brings the peripheral edge of the disc-shaped piezoelectric element into close contact with the valve housing side.

Effects According to the present invention, with the above-described configuration, the deflection of the central portion of the disc-shaped piezoelectric element due to voltage application causes a change in the passage area of the inlet hole and the outlet hole, so that the flow rate can be adjusted by voltage control. Further, since the piezoelectric element is disk-shaped and its peripheral edge is held and is in an airtight state, there is no fear of external leakage. In this way, the disc-shaped piezoelectric element itself is a valve body that adjusts the flow rate, and is a part of the sealing means for preventing external leakage, so that power consumption can be reduced and the structure can be simplified.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIGS. 1A and 1B, reference numeral 13 denotes a disc-shaped piezoelectric element in which a piezoelectric ceramic material 14 is attached to a metal disc 15, and the lower surface of its peripheral edge 16 is connected to an elastic ring 18 provided in a groove of a valve housing 17. The upper surface is pressed by a holding case 19 and is in close contact with the elastic ring 18. Disc-shaped piezoelectric element 1
An inlet hole 20 and an outlet hole 21 correspond to the flat bottom surface of No. 3.
is provided in the valve housing 17 and the flow path 22
This configuration is arranged in series as follows. Elastic valve seats 23 and 24 made of rubber or the like are fixed to the inlet hole 20 and the outlet hole 21, respectively, at the portions that come into contact with the disc-shaped piezoelectric element 13. Flexible electric wires 25 and 26 are connected to the disc-shaped piezoelectric element 13, and a voltage is applied from terminals 27 and 28.

In the above configuration, when the applied voltage is zero, the disc-shaped piezoelectric element 13 is flat, so the elastic valve seat 23
and 24 are in contact with the lower surface of the piezoelectric element, and the flow path is closed. When a voltage is applied, the central portion of the disc-shaped piezoelectric element 13 is bent into a convex shape as shown in FIG. 1B, so that the inlet hole 20 and the outlet hole 21 communicate with each other to form a fluid passage. Since the amount of deflection at this time can be controlled by the voltage value, the fluid passage area can be adjusted by the voltage. The upper surface of the peripheral edge 16 of the disc-shaped piezoelectric element 13 is in contact with the rigid holding case 19, but the lower surface is in contact with the elastic ring 18, so that when it bends, the elastic ring 18 deforms and obstructs the bending. There isn't.

Next, another embodiment of the present invention will be explained based on FIG. An elastic sheet 29 is pasted on the lower surface of the disc-shaped piezoelectric element 13, and a seal ring 30 protruding inward is integrally molded at the lower part of the bend. The seal ring 30 is in close contact with the valve housing 17 in the radial direction to form an airtight state. The peripheral edge of the upper surface of the disc-shaped piezoelectric element 13 is configured to be pressed and held toward the valve housing 17 by a spring 32 via a retaining ring 31.

With this configuration, when no voltage is applied as shown in FIG. 2A, the flat surface of the disc-shaped piezoelectric element 13 presses the elastic sheet 29 toward the inlet hole 20 and the outlet hole 21, and the flow path is blocked. The state will be as follows. Next, when a voltage is applied, the flow path becomes open as shown in FIG. 1B, and the passage area can be controlled by the voltage value, as in the embodiment shown in FIG. 1. In this configuration, the disk-shaped piezoelectric element 1
3 is pressed and held by a spring 32, the opening area is larger than that of the embodiment shown in FIG. 1 without hindering the bending. Furthermore, since it is completely separated from the fluid passage 22 by the elastic sheet 29, it is suitable for fluids that require electrical insulation.

Effects of the Invention As described above, the fluid control valve of the present invention provides the following effects.

(1) Since the disc-shaped piezoelectric element is used as the driving source, power consumption is low, and the structure can be simplified because the peripheral part of the disc has a sealed structure and the central part is used as a valve body.

(2) Since there are no resistance elements such as sliding parts for the operation of the disc-shaped piezoelectric element, there is no operation hysteresis.

(3) The disc-shaped piezoelectric element is structured so that at least one side thereof is in contact with the fluid, and no potential difference is applied to the fluid. Therefore, it is safe when used for fluids with low electrical resistance or flammable fluids, and does not cause an increase in power consumption due to leakage current.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a fluid control valve according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of a second embodiment, and FIG. 3 is a longitudinal sectional view of a conventional fluid control valve. FIG. 4 is a longitudinal sectional view of another conventional example. 13...Disc-shaped piezoelectric element, 16...Disc-shaped piezoelectric element periphery, 17...Valve housing, 18...Elastic ring, 19...Holding case, 20...Inlet hole, 21...Outlet hole, 29...Elastic sheet, 30
... Seal ring, 32 ... Spring.

Claims (1)

[Scope of Claims] 1. A valve housing having a disk-shaped piezoelectric element whose central portion is deformed by voltage application, an inlet hole and an outlet hole formed corresponding to the central flat surface of the disk-shaped piezoelectric element, and the valve housing. A fluid control valve comprising: a sealing means for airtightly sealing between a valve housing and a circumferential edge of the disc-shaped piezoelectric element; and a holding means for bringing the circumferential edge of the disc-shaped piezoelectric element into close contact with the valve housing. 2. The fluid control valve according to claim 1, wherein the sealing means is constituted by an elastic member that deforms integrally with the piezoelectric element at the center and closely contacts the valve housing in the radial direction at the periphery.