JPS6134612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to various gas or liquid pressure sensors.

Conventionally, as means for detecting and measuring atmospheric pressure or water pressure, there are methods using a mercury column, an aneroid method, a capacitance method, and the like. However, although these conventional methods have high accuracy in measuring absolute pressure, it is difficult to measure minute changes in atmospheric pressure or water pressure, and they are also difficult to measure when placed in places with strong vibrations, such as vehicles. The problem was that it was not possible to make measurements.

The present invention improves the disadvantages of the conventional pressure sensor and provides a pressure sensor that has an extremely simple structure, operates accurately, and has quick response.

The present invention will be described below with reference to the drawings showing embodiments. The pressure sensor according to the present invention has a sealed three-dimensional space 1, and at least two wall surfaces of the peripheral wall, preferably opposing wall surfaces, are flexible thin plates 2. .
Flexible piezoelectric elements 4, 4 are polymerized and pasted on the outer surface of the lead wires 5, 4 with the same polarity facing each other.
5 in parallel. The cylindrical body 3 includes a closing body 6 that seals the upper and lower openings of the cylindrical body 3.
6 is fixed to the inner surface of the frame 7 by an appropriate means, and the cylindrical body is inserted through the open portion 8 of the frame 7 or the through hole 9 appropriately bored in the wall surface of the frame 7. Atmospheric pressure or hydraulic pressure is applied directly to the surface of 3.

In this way, the pressure sensor according to the present invention has flexible thin plates 2, 2 formed on the opposing wall surfaces of the peripheral wall forming the sealed three-dimensional space 1, and has flexible thin plates 2, 2 on the outer or inner surfaces of the thin plates 2, 2. Since the piezoelectric elements 4, 4 are polymerized and connected in parallel, when the external pressure increases more than the pressure in the sealed internal space 1 of the cylindrical body 3, As shown in FIG. 2, the piezoelectric elements 4, 4 are distorted inwardly together with the flexible thin plates 2, 2, and a potential corresponding to the amount of distortion of the piezoelectric elements 4, 4 is generated between A and B. By detecting the magnitude of this potential, it is possible to know the magnitude and change of external pressure. Conversely, when the external pressure decreases, the thin plates 2, 2 and the piezoelectric elements 4, 4 are distorted outward in the opposite manner to the above, and a different potential is generated, and low pressure can be detected in the same way.

However, rather than changes in external pressure, one thin plate 2 is affected by vibration, turbulence, acceleration, etc.
When the thin plate 2 is distorted inwardly or inwardly, the other thin plate 2 is distorted outwardly or inwardly in parallel with the one thin plate 2, as shown in FIG. This is canceled out by no output, and distortions in the piezoelectric elements 4 due to factors other than external pressure fluctuations are not detected as pressure changes.

Although the embodiment shows a mode in which the piezoelectric elements 4, 4 are bonded to thin plates 2, 2 facing each other in a polymer manner, in order to offset the generation of erroneous signals due to disturbance factors to the cylindrical body 3 from multiple directions, In this case, the cylindrical body 3 is made into a polygonal shape, for example, hexagonal or octagonal, and each side of the cylindrical body 3 is made of a flexible thin plate, and piezoelectric elements are superimposed and bonded to all the thin plates and connected in parallel. You may.

As described above, according to the pressure sensor of the present invention, pressure changes can be accurately detected with an extremely simple structure, and distortion of the piezoelectric element due to factors other than external pressure such as vibration, rocking, or acceleration can be canceled out. Since the pressure sensor is not detected as a signal, it is particularly suitable as a pressure sensor installed inside a moving object such as a ship or a vehicle.

[Brief explanation of the drawing]

The drawings schematically show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional view, Fig. 2 is a sectional view showing the operation procedure, and Fig. 3 shows the state of distortion due to factors other than external pressure. FIG. 1 is an internal space, 2 is a flexible thin plate, 3 is a cylindrical body,
4 is a piezoelectric element, 5 is a lead wire, 6 is a closed body, 7 is a frame, 8 is an open part of the frame, and 9 is a through hole.

Claims (1)

[Claims] 1 The opposing wall surfaces of the peripheral wall forming a sealed three-dimensional space are formed of flexible thin plates, piezoelectric elements are superimposed on the outer or inner surface of the thin plates, and the piezoelectric elements are connected in parallel, and changes in external pressure are achieved. A pressure sensor characterized in that the piezoelectric element is distorted by the distortion of the thin plate caused by the distortion, and the potential generated by this distortion is detected to measure pressure fluctuations.