JPS63312582A - Piezoelectric valve - Google Patents

Abstract

PURPOSE:To have no influence of liquid pressure and dynamic pressure produced by flowing of a fluid by providing a plurality of movable plates which are flexed in the direction of board thickness when voltage is applied, valve elements and valve ports confronting a part of a moving path for the valve elements. CONSTITUTION:When voltage is applied, the movable plates of plural movable plates 10 to which voltage is applied are flexed in the direction of board thickness and shifted laterally, confronting valve element 14 and valve ports 15. The flexure of the movable plates 10 is changed depending upon the magnitude of voltage to change the opening degree of the valve ports 15. As the valve elements 14 are disposed vertically to a flexible shaft 12 on extension substantially parallel to a flexible shaft of the movable plates 10, dynamic pressure produced by flowing of a fluid exerts stress in the direction substantially parallel to the flexible shaft 12 of the movable plates 10 through the valve elements 14. The rigidity for bending stress in the direction substantially parallel to the flexible shaft 12 of the movable plate 10 is large to hardly be influenced by dynamic pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a piezoelectric valve that controls fluid with a movable plate that bends when a voltage is applied.

2. Description of the Related Art As shown in FIG. 10, a conventional piezoelectric valve of this type has a valve actuating plate 1 made of a pair of ferroelectric materials bonded together, and a valve body 2 provided thereon so as to face the valve body 2. The valve seat 3 is configured, and the voltage applied to the valve actuating plate 1 causes the valve actuating plate 1 to bend due to the electrostrictive transverse effect, and the valve body 2 changes the lift height a with the valve seat 3, thereby controlling the flow rate. I was starting to take control.

(For example, Japanese Patent Publication No. 55-30143) However, in the above configuration, since the dynamic pressure stress due to the flow of fluid acting on the valve body 2 is received in the thickness direction of the valve actuation plate 1, the valve actuation plate The rigidity of No. 1 is weak against the dynamic pressure of the scum, and the flow rate characteristics with respect to voltage are distorted as shown in FIG. 11, which is a problem. In other words, in addition to the deflection of the valve operating plate 1 due to the applied voltage, the deflection strain was easily affected by the dynamic pressure of the flow.

Furthermore, as shown in FIG. 12, a valve body 5 is provided at the cantilever-supported free end of the bimorph type electrostrictive element plate 4, and switching channels 6 and 7 are formed in the substantially centrifugal direction of the valve body 5. There was a switching valve in which the valve body 5 slides with respect to the opening 8.9 of the valve.

(For example, Japanese Unexamined Patent Publication No. 61-38278) However, even in such a configuration, the valve element 5 receives fluid pressure and dynamic pressure due to the flow of the fluid, and the electrostrictive element plate acts to bend due to the force. It was not sufficient to be unaffected by pressure or dynamic pressure. In other words, although it is a well-known fact that bimorphs have weak rigidity in the direction of deflection, this is due to the fact that the force received by dynamic pressure is in the same direction as the direction of deflection due to voltage in any configuration.

In addition, piezoelectric flow control devices having a plurality of piezoelectric members, valve seats, and valve bodies have the same problems as above. (For example, Japanese Unexamined Patent Publication No. 59-140980) Problems to be Solved by the Invention The present invention solves these conventional problems, and is less susceptible to the influence of fluid pressure and dynamic pressure due to fluid flow. It is an object of the present invention to provide a piezoelectric valve having a plurality of valve bodies.

Means for Solving the Problems In order to solve the above problems, the piezoelectric valve of the present invention has a movable plate that is at least partially supported, and when a voltage is applied, the movable plate deflects in the thickness direction about the supported portion as a deflection axis. and a valve body provided perpendicularly to the deflection axis on an extension substantially parallel to the deflection axis, and a plurality of valve ports facing a part of the movement path of the valve body. This is a modified version of a piezoelectric valve.

Function: With the above-described configuration, the movable plate deflects in the thickness direction when voltage is applied, and the valve body shifts laterally while facing the valve port. The amount of deflection of the movable plate changes depending on the magnitude of the voltage, and the degree of opening of the valve port also changes. The valve body is installed perpendicular to the deflection axis of the movable plate on an extension that is almost parallel to the deflection axis, so the dynamic pressure due to the fluid flow is transmitted through the valve body and is almost parallel to the deflection axis of the movable plate. This will exert stress in the direction.

Therefore, the stiffness against bending stress in a direction substantially parallel to the deflection axis of the movable plate is much greater than the stiffness in the plate thickness direction, making it possible to obtain a piezoelectric valve that is less susceptible to the effects of dynamic pressure.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In FIGS. 1 to 3, reference numeral 10 denotes a movable plate of a bimorph element made of a piezoelectric ceramic material, and a part of this movable plate 10 is supported by a support 11. The movable plate 10 is supported so that when a voltage is applied, the movable plate 10 is deflected in the thickness direction 13 with the portion supported by the support 11 serving as a deflection axis 12. Further, the valve body 14 is fixed to the movable plate 10 on an extension substantially parallel to the deflection shaft 12 and perpendicular to the deflection shaft 12. The valve port 15 is configured to face a part of the movement path 16 of the valve body 14.

Note that the movable plate 10. Valve body 14. A plurality of valve ports 15 are arranged, and FIG. 1 shows an example thereof in a perspective view.
FIGS. 2 and 3 show the movable plate 10. Valve body 14. Valve port 15-1
This figure shows the unit taken out.

In the above configuration, when the applied voltage is zero, the movable plate 10
is flat, and the valve body 14 covers the entire valve port 15. Therefore, the fluid flow is blocked. When a voltage is applied to the movable plate 10, the amount of deflection of the movable plate 10 changes depending on the magnitude of the voltage. In order to change the amount by which the valve body 14 is laterally displaced from directly above the valve port 15 in accordance with the deflection of the movable plate 10, the opening area of the valve port 14 is changed to vary the fluid flow rate.

In this case, the fluid can flow either in the direction of the arrow in FIG. 3 or in the opposite direction. Further, the fluid pressure and the dynamic pressure due to the fluid flow act in a direction parallel to the deflection axis 12 of the movable plate 10. Since this acts in the direction in which the rigidity of the movable plate 12 is greatest, the movable plate 10 does not bend due to dynamic pressure and has the effect of being almost unaffected by the dynamic pressure. Furthermore, when a voltage is applied, the movable plate 10 bends in the thickness direction, and the valve body 14 bends at the valve port 15.
Since the configuration is such that a straight flow path can be formed without anything interfering with the flow flowing out from or flowing into the valve port 15, a piezoelectric valve with extremely small pressure loss in the flow path is used. It has the unique effect of being realized. Also, the movable plate 10 is placed under a bimorph type pressure'? When composed of element plates,
As is well known, bimorph has a structure in which two pieces of piezoelectric material are glued together, and when a voltage is applied, one contracts and the other expands, allowing for a relatively large amount of deflection, and the length of the movable plate can be short, making it a small and compact piezoelectric valve. can.

Furthermore, the fact that the movable plate 10 is of a cantilever type is also effective in increasing the amplitude of the valve body. Further, when the voltage applied to the movable plate 10 is unidirectional, the valve body 14 is also displaced in only one direction on one side with respect to the valve port 15, thereby varying the degree of opening of the valve port. When the applied voltage is in two directions, forward and reverse, the valve body 14 is also displaced in both left and right directions. In particular, the voltage frequency applied to the movable plate 10 is
By controlling the movable plate at the resonant frequency, the amplitude of the movable plate becomes larger compared to the case of a non-resonant frequency voltage, so there are effects such as a relatively low voltage, a short movable plate, and miniaturization.

Furthermore, by matching the resonant frequency of the movable plate to the commercial power frequency of 5 Q Hz or 60 Hz, the control circuit can be simplified. The reason why the fluid flow rate can be controlled by changing the amplitude of the valve body when controlling the voltage at the resonance frequency is that as the amplitude becomes thicker, the area of the valve opening increases, as shown in Figure 4. be.

Furthermore, as shown in FIG. 1, a movable plate 10. In a configuration in which a plurality of valve bodies 14 and valve ports 15 are each arranged,
By applying voltages to the plurality of movable plates 10 with different phases, there is a unique effect that pulsation of the flow rate can be alleviated. To make this easier to understand, the fifth
Figures (a) and (b) show a comparison of flow rate waveforms with time on the horizontal axis and flow rate on the vertical axis.

Figure 6 shows an example of the voltage-flow characteristics when the voltage applied to the movable plate 10 is increased or decreased. The effect is that smooth and stable characteristics can be obtained without causing discontinuous abnormal changes.

In addition, in FIG. 1, the plurality of valve ports 15 have the same flow path cross-sectional area, but by configuring them to have different predetermined cross-sectional areas, the flow path of the valve ports 15 opened by applying a voltage to the movable plate 10. This has the effect that a flow rate corresponding to the size of the cross section can be reliably obtained.

For example, if this is used in a gas combustion device, multiple valve ports 1
By sequentially opening 5, the firepower can be reliably adjusted in multiple stages. In this way, instead of configuring the flow path cross-sectional areas of the plurality of valve ports 15 to have different sizes, at least one of the plurality of valve ports 15 or the flow path leading thereto has a certain restriction for regulating the flow rate. A similar effect can be achieved with the configuration.

Further, by arranging a plurality of movable plates 10 in parallel as shown in FIG. 1, the terminal portions electrically connected to the movable plates 10 can be grouped in the same direction, which has the effect of making wiring work easier.

Furthermore, in other embodiments of the present invention, particularly regarding the movable plate, FIGS.
This will be explained using FIG.

FIG. 7 shows an example in which the lengths of the vaginas from the bending axes of the plurality of movable plates 10 to the valve body 14 are different.
This has the effect that the 4 swing spaces can be arranged without waste, and the piezoelectric valve can be made small and compact. Further, FIG. 8 shows an example in which a plurality of movable plates 10 are arranged in a peg-like manner, and the same effect as in the case of FIG. 7 is obtained.

The movable plate 15 shown in FIGS. 9 and 10 is formed of a piezoelectric element plate 18 on the side near the deflection shaft 12, and a plate 17 having spring properties such as a metal plate or a resin plate on the side near the valve body 14. , when a voltage is applied to the piezoelectric element plate 18, the spring plate 17
The movement resembles a fish's tail fin, and acts to further expand the amplitude displacement of the valve body 14, which has the effect of making the piezoelectric body 18 smaller.

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

(1) A movable plate, at least partially supported, which deflects in the thickness direction with the supported portion as the deflection axis when a voltage is applied; Since the structure has a plurality of valve bodies and a plurality of valve ports facing a part of the movement path of the valve body, stable characteristics are hardly affected by dynamic pressure due to fluid flow. This has the effect that it can be obtained.

(2) Since it has multiple movable plates, valve bodies, and valve ports, it has unique effects such as varying the flow rate in multiple stages and mitigating flow pulsations depending on the timing of opening the valve ports. There is.

(3) When a voltage is applied, the movable plate bends in the thickness direction, and the valve body shifts sideways while facing the valve port, so that there is nothing to obstruct the flow flowing out from or flowing into the valve port, and the flow flows straight. Since the structure is such that a passage can be formed, it has the unique effect of realizing a piezoelectric valve with extremely small passage pressure loss.

(4) Since the movable plate is configured to receive fluid dynamic pressure via the valve body in the direction in which the bending rigidity is highest, the valve opening degree can be controlled by voltage regardless of the fluid flow state, so the opening/closing valve
It has a wide range of uses, including not only switching valves but also flow rate proportional control valves.

(5) Compared to valves that use electromagnetic force or motors, the structure is simpler, the number of parts is smaller, and the power consumption is lower.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a piezoelectric valve according to a first embodiment of the present invention, Fig. 2 is a partial plan view of the piezoelectric valve, Fig. 3 is a partial sectional view of the piezoelectric valve, and Fig. 4 is a partial sectional view of the piezoelectric valve. Figure 5 (a), (b) is an explanatory diagram of the principle of varying the flow rate when controlled by constant frequency voltage.
6 is a typical flow rate characteristic diagram of the same piezoelectric valve, and FIGS. 7 to 10 are partial plan views and front views of piezoelectric valves according to still other embodiments of the present invention. , FIG. 11 is a front sectional view of a conventional piezoelectric valve, FIG. 12 is a typical flow characteristic diagram of the same piezoelectric valve, and FIG. 13 is a front sectional view of another conventional piezoelectric valve. DESCRIPTION OF SYMBOLS 10... Movable plate, 11... Support body, 12... Deflection shaft, 134... Plate thickness direction, 14... Valve body, 15...
... Valve port, 16... Movement route. Name of agent: Patent attorney Toshio Nakao Idiot 1 person 10 - 1 movable rebellion / 1 - 1 single cross stock / 2 - bending glaze 3 - 1 rishishi 4 counterfeit 1 ri 16 - waiting Fujibuta 10 - One mobile hire No. 4 map. Medicine 5 Figure 6 Figure 7 Figure 9

Claims (9)

[Claims] (1) A movable plate, at least partially supported, which deflects in the thickness direction with the supported portion as the deflection axis when a voltage is applied; A piezoelectric valve comprising a plurality of valve bodies and a plurality of valve ports facing a part of a movement path of the valve body. (2) The piezoelectric valve according to claim 1, wherein the voltage applied to at least one of the plurality of movable plates can be adjusted based on the resonance frequency. (3) The piezoelectric valve according to claim 1, wherein the voltage applied to the plurality of movable plates can be applied with a phase shift. (4) The piezoelectric valve according to claim 1, wherein at least one of the plurality of valve ports or the flow path leading thereto has a certain restriction for regulating the flow rate. (5) The piezoelectric valve according to claim 1, in which at least one of the plurality of valve ports has a different flow path cross-sectional area. (6) The piezoelectric valve according to claim 1, wherein a plurality of movable plates are arranged in parallel. (7) The piezoelectric valve according to claim 1, wherein the plurality of movable plates are configured with different combinations of arm lengths from the deflection shaft to the valve body. (8) The piezoelectric valve according to claim 1, wherein a plurality of movable plates are arranged radially. (9) A patent in which at least one of the plurality of movable plates is composed of a piezoelectric element plate on the side near the deflection axis, and a flexible and springy material such as a metal plate or a resin plate on the side near the valve body. A piezoelectric valve according to claim 1.