JPH0314616Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an on-off valve that opens and closes a flow path of a fluid such as liquid, air, or combustible gas, and particularly relates to a piezoelectric on-off valve using a piezoelectric element.

[Conventional technology]

Solenoid valves consume a lot of power and generate a lot of electromagnetic noise, but piezoelectric on-off valves using piezoelectric elements are characterized by low power consumption and no electromagnetic noise.

In conventional piezoelectric on-off valves, the piezoelectric element directly drives the valve body.

[The problem that the idea attempts to solve]

Therefore, the valve body cannot be driven greatly (the stroke is small). The valve closing force is small because it is only the driving force from the piezoelectric element. The displacement characteristics of piezoelectric elements vary significantly depending on temperature and other factors, resulting in unstable operation. When opening and closing channels for liquid or flammable gas, there is a high risk of electric shock and explosion. It is necessary to maintain the open or closed state of the valve body by keeping the power applied, and the power consumption increases accordingly. There were issues such as the inability to adjust the operating point and operating sensitivity.

[Means to solve the problem]

In order to solve the above-mentioned problems, the piezoelectric on-off valve of the present invention fixes one end of the piezoelectric element 2 in the casing 1 and provides the connecting member 3 at the other end of the piezoelectric element 2, as shown in the first figure. The connecting member is swingably supported by the casing, and the arcuate plate spring 5 is supported between the end of the connection member 3 on the side opposite to the element and the casing portion facing thereto. A valve body 8 is provided in the center of the spring 5 to open and close between the inflow and outflow ports 6 and 7.

[Effect]

When the drive power 12 is applied to the piezoelectric element 2, the piezoelectric element 2 is displaced and the arcuate leaf spring 5 snaps as shown by the solid line in FIG.
is pressed against the valve seat 9a of the flow path 9 provided between the inflow and outflow ports 6 and 7, thereby closing the flow path 9.

When the driving power source 12 of the piezoelectric element 2 is turned off or when the polarity is applied in the opposite direction, the piezoelectric element 2 is displaced in the opposite direction to that described above, and the arcuate leaf spring 5 is moved as shown by the imaginary line in FIG. As a result, the valve body 8 separates from the valve seat 9a of the flow path 9 provided between the inflow and outflow ports 6 and 7, thereby opening the flow path 9.

〔Example〕

An embodiment of the piezoelectric on-off valve of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a casing, and 2 is a piezoelectric element, one end of which is insulated and fixed within the casing 1 by a support part 13.

The piezoelectric element 2 includes, for example, two film-like piezoelectric bodies 11 and 1.
1 are bonded together and film-like electrodes 10a and 10b are formed on the bonded surface and both outer surfaces, and the entire surface is preferably insulated.

The other end of the piezoelectric element 2 is connected to a connecting member 3,
This connecting member 3 is swingably supported on the inner surface of the casing by an elastic partition plate 4 made of rubber or the like that divides the casing 1 into sections. An arcuate leaf spring 5 is supported between the end of the connection member 3 on the side opposite to the element and the casing part facing thereto. Reference numeral 15 denotes a support portion of this leaf spring 5.

As the leaf spring 5, phosphor bronze, stainless steel,
Other spring steels, plastics, etc. can be used.

A valve body 8 is provided in the center of the arcuate leaf spring 5 to open and close the flow path 9 by coming into contact with and separating from the valve seat 9a of the flow path 9 provided between the inflow and outflow ports 6 and 7. .

Reference numeral 12 is a driving power source which is applied to the piezoelectric element 2 by turning it on and off or by switching the polarity. In FIG. 1, a voltage E is applied between electrodes 10a and 10b of a piezoelectric element 2 by changing the polarity of a DC power source 12 using a switch 14.

In the above configuration, the membrane electrode 10 of the piezoelectric element 2
The voltage E of the DC power supply 12 is applied to the electrode 10 between a and 10b.
When a voltage is applied so that a has a positive polarity and electrode 10b has a negative polarity, the piezoelectric element 2 bends and the connecting member 3 is displaced, causing the arcuate leaf spring 5 to snap as shown by the solid line in FIG. As a result, the valve body 8 comes into pressure contact with the valve seat 9a of the flow path 9 provided between the inflow and outflow ports 6 and 7, thereby closing the flow path 9.

Since the valve body 8 is driven not only by the displacement force of the piezoelectric element 2 but also by the snapping action of the arcuate leaf spring 5, it can be driven to a greater extent (the stroke can be made larger) than when it is driven only by the conventional driving force from the piezoelectric element 2.

The valve closing force becomes much larger because not only the displacement force of the piezoelectric element 2 but also the spring force due to the snapping action of the arcuate leaf spring 5 acts, and the flow path can be reliably shut off.

The voltage E of the DC power source 12 is applied between the membrane electrodes 10a and 10b of the piezoelectric element 2 to the electrode 10a with the opposite polarity to the above.
When the voltage is applied so that the polarity is negative and the electrode 10b is positive, the piezoelectric element 2 is displaced in the opposite direction to the above, and the arcuate leaf spring 5 snaps in the opposite direction as shown by the imaginary line in FIG. As a result, the valve body 8 separates from the valve seat 9a of the flow path 9 provided between the inflow and outflow ports 6 and 7, thereby opening the flow path 9.

Although the displacement characteristics of the piezoelectric element 2 vary considerably depending on temperature and the like, since the valve body 8 is opened and closed by the snap action of the arcuate leaf spring 5, its operation is stable regardless of changes in characteristics.

Further, as shown in the second figure, by setting the initial pressure applied to the connecting member 3 using the spring 16 and the adjusting screw 17, the operating point and operating sensitivity can be adjusted.

Furthermore, if an AC power source is used as the drive power source 12,
The valve body 8 can be opened and closed according to its frequency, and the flow rate of the fluid can be controlled.

[Effect of idea]

As described above, according to the present invention, since the piezoelectric element 2 is used, the power consumption is small and there is no generation of electromagnetic noise.
It can be driven not only by the displacement force but also by the snap action of the arcuate leaf spring 5. Since not only the displacement force of the piezoelectric element 2 but also the spring force due to the snapping action of the arcuate leaf spring 5 acts, the valve closing force can be much increased, and the flow path can be reliably shut off. Since the valve body 8 can be opened and closed by the snap action of the arcuate leaf spring 5, stable operation can be obtained regardless of changes in displacement characteristics due to temperature or the like. Since the open or closed state of the valve body 8 can be maintained by the snap operation state of the arcuate leaf spring 5, there is no need to maintain the applied state of the power supply, and power can be saved accordingly. This provides effects such as being able to adjust the operating point and operating sensitivity.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of an embodiment of the piezoelectric on-off valve of the present invention, and FIG. 2 is a sectional view showing a part of the structure in which the operating point and operating sensitivity can be adjusted. DESCRIPTION OF SYMBOLS 1... Casing, 2... Piezoelectric element, 3... Connection member, 4... Elastic partition plate, 5... Arcuate leaf spring,
6... Inflow port, 7... Outlet port, 8... Valve body, 9...
...Flow path, 9a... Valve seat.

Claims (1)

[Scope of utility model registration request] one end of a piezoelectric element is fixed within a casing, a connecting member is provided at the other end of the piezoelectric element, and the connecting member is swingably supported by the casing;
An arcuate leaf spring is supported between the opposite end of the connecting member and the casing part opposite thereto, and a valve body is provided in the center of the arcuate leaf spring to open and close between the inflow and outflow ports. A piezoelectric type on-off valve.