JPH0392740A - Liquid pressure sensor - Google Patents

Abstract

PURPOSE:To prevent the breakdown of a semiconductor pressure sensor by hydraulic surge by providing a device for discharging surge pressure at a liquid- pressure introducing hole in the vicinity of the semiconductor pressure sensor. CONSTITUTION:An opening is formed in the wall of a liquid-pressure introducing hole of a housing 5. The hole is normally closed with a check valve 11 which is pushed with a spring 11a. When hydraulic surge in pressure oil 12 exceeds a specified value determined with the spring 11a, the hydraulic surge is discharged into a drain. Therefore, a semiconductor diaphragm 1a comprising glass is not broken.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hydraulic pressure sensor device, and more particularly to a structure for preventing a diaphragm portion of a semiconductor pressure sensor from being destroyed by hydraulic surge.

[Conventional technology]

FIG. 3(a) is a sectional view showing a general hydraulic pressure sensor device using a semiconductor pressure sensor, and FIG. 3(b) is an enlarged view showing the inside of the semiconductor pressure sensor. In the figure, (1) is the semiconductor pressure J sensor, (1a) is the semiconductor diaphragm of the semiconductor pressure sensor, (2) is the screw, (3) is the sabot, (4) is the circuit board, and (5) is the semiconductor diaphragm of the semiconductor pressure sensor.
) is the housing, (6) is the sensor mount, (7) is O
Ring, (8) is O-ring, (9) is holder, (12)
indicates pressure oil from a hydraulic bomb. This pressure is used, for example, to select the clutch in a car transmission.

In order to detect this oil pressure, a semiconductor pressure sensor (1) is attached to the sensor mount (6) via a housing (5). This semiconductor pressure sensor (1) passes pressure oil (12) from a hydraulic bomb through a hydraulic pressure introduction hole provided in the housing (5) and a hydraulic pressure introduction pipe connected to the sensor (1). It is received by the semiconductor diaphragm (1a) in (1). The thus measured oil pressure fluctuates as shown in FIG. 2(b), and it is recognized that there is a hydraulic surge in particular. That is,
The semiconductor pressure sensor detects oil pressure sharply.

[Problems to be Solved by the Invention] However, the semiconductor guyafram of the semiconductor pressure sensor is made of glass and does not have the strength of metal materials, and is destroyed by large hydraulic surges that occur from time to time.

The present invention has been made to solve these problems, and its purpose is to prevent semiconductor pressure sensors from being destroyed by hydraulic surges. The pressure sensor device is provided with a device for releasing surge pressure into the hydraulic pressure introduction hole to the semiconductor pressure sensor.

[Effect]

In this invention, a device for releasing surge pressure is provided to the hydraulic pressure introduction hole near the semiconductor pressure sensor, so the surge pressure is released to the outside before destroying the semiconductor diaphragm of the semiconductor pressure sensor. .

[Embodiment] FIG. 1(a) is a sectional view showing a hydraulic pressure sensor device according to an embodiment of the present invention, and FIG. 1(b) is an enlarged view showing the inside of a semiconductor pressure sensor. In the figure, (1)
- (9) and (12) indicate the same members or equivalent parts as in the conventional example. In the present invention, an orifice plate (10) is provided at the entrance of the hydraulic pressure introduction hole of the housing (5), and an opening having a larger area than the central opening of this orifice plate (O) is the opening of the hydraulic pressure introduction hole. It's hanging on the wall. This opening is a check valve [J1] pressed by a spring (lla).
is normally closed. In addition, (llb) is a blind stopper, and (13) is a toren.

Thus, the hydraulic surge in the pressure oil (12) is caused by the spring (
lla), the drain (
13). Therefore, the glass semiconductor diaphragm (1a) will not be destroyed.

By the way, by providing a rounded chair plate (10) and making the area of its central opening smaller than the area of the surge pressure release opening, the check valve can be made smaller and can effectively release surge pressure. If only a check valve is provided, the check valve would have to be larger, and the response would be delayed, making the protection of the semiconductor diaphragm less effective.

〔Effect of the invention〕

As explained above, the present invention is provided with a device for releasing surge pressure at the hydraulic pressure introduction hole of a hydraulic pressure sensor device using a semiconductor pressure sensor, so that the semiconductor diaphragm is prevented from being destroyed by surge pressure. It will disappear.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a first embodiment of a hydraulic pressure sensor device according to the present invention. FIG. 2 is a diagram comparing waveforms of oil pressure measured by a hydraulic pressure sensor device. FIG. 3 is a diagram showing a conventional hydraulic pressure sensor device. In the figure, (1) is a semiconductor pressure sensor, (la) is a semiconductor diaphragm of the semiconductor pressure sensor, (2) is a screw, (3) is a support, (4) is a circuit board, (
5) is the housing, (6) is the sensor mounting base, (7).
(8) is an O-ring, (9> is a holder, (10) is a rifling plate, (11) is a check valve, (12) is a pressure oil,
(13) is a tren. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A hydraulic pressure sensor device using a semiconductor pressure sensor, characterized in that a surge pressure release device is provided at a portion of a hydraulic pressure introduction hole to the semiconductor pressure sensor.