JPH0719978A - Pressure sensor - Google Patents

Abstract

PURPOSE:To measure pressure in a wide range by integrally forming a substrate with a diaphragm section deformed by the measured pressure and a connecting terminal section protruded partially, providing a resistor strain gauge near the center of the diaphragm section, and providing a connecting terminal on the connecting terminal section. CONSTITUTION:A substrate 10 made of a metal plate is integrally formed with a nearly circular thin plate-like diaphragm section 11 supporting an edge section 16 with a pedestal 18 and a rectangular connecting terminal section 12 partially protruded from it to the outside of a case 21 and receiving no pressure. A groove-like slit 17 is formed between the diaphragm section 11 and the connecting terminal section 12 of the substrate 10. The pedestal 18 having a pressure chamber forming recess 19 for introducing pressure is stuck to the lower face of the substrate 10, and a pressure feed port 20 is communicated with the recess 19. A fluid is fed into the recess 19 from the feed port 20, the pressure presses and strains the diaphragm section 11, the strain quantity is detected by a resistor strain gauge 30, and it is detected by another detecting mechanism through a connecting terminal 14. The displacement quantity of the diaphragm section 11 can be measured in a wide range, and the pressure can be accurately measured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor having a deformable substrate equipped with a resistor strain gauge and capable of measuring pressure in a relatively wide range.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for pressure sensors as means for detecting the pressure at various parts in order to optimize the control of automobile engines and refrigeration systems. For example, Japanese Patent Publication No. 62-12458. There are pressure sensors as described. The conventional pressure sensor will be described below.

FIG. 5 is an exploded perspective view of a conventional pressure sensor. In FIG. 5, 1 is a pressure sensor, 2 is a pressure sensor element, and 3 is a terminal. In the prior art pressure sensor 1,
The terminal 3 is provided on the outer peripheral portion of the pressure detecting portion of the pressure sensor element 2. Reference numeral 4 is a lead wire, and 5 is a circuit board.

In the prior art pressure sensor 1, a lead wire 4 is used to electrically connect the pressure sensor element 2 to the circuit board 5, and the lead wire 4 is projected from the terminal 3 of the pressure sensor element 2. They were connected together by soldering. Then, the lead wire 4 connected to the terminal 3 of the pressure sensor element 2 by soldering as described above is inserted into the through hole 5a of the circuit board 5 to insert the pressure sensor element 2 into the through hole 5a.
Was electrically connected to the circuit board 5.

[0005]

However, in the configuration of the prior art as described above, since the terminal 3 is provided on the outer peripheral portion of the portion of the pressure sensor element 2 which detects the pressure, the portion which detects the pressure is not provided. There is a problem in that the accuracy is deteriorated because the amount cannot be made large and therefore the displacement amount is small.

Further, since the strain of the pressure sensor element 2 due to the pressure is transmitted to the terminal 3, the lead wire 4 and the through hole 5a of the circuit board 5 as it is, a crack is generated in the soldered portion in terms of reliability. There were also problems.

The present invention solves the above-mentioned problems of the prior art, and an object thereof is to provide a pressure sensor having a wide range of pressure detection, a large displacement amount, high accuracy, and high reliability. It was done.

[0008]

According to the present invention for achieving the above object, a diaphragm portion deformably formed by a measured pressure and a connecting terminal portion partially protruding from the diaphragm portion are integrally formed. The pressure sensor is characterized in that a resistor strain gauge is arranged in the vicinity of the center of the diaphragm portion of the formed base body, and a connection terminal connected to the resistor strain gauge is provided in the connection terminal portion.

The preferred embodiment of the invention described above is
It is characterized in that a slit is provided between the diaphragm portion of the base and the connection terminal portion.

[0010]

In the pressure sensor of the present invention, a part of the base body constitutes the diaphragm portion, and a part of the base body is further provided with a connection terminal portion partially protruding from the diaphragm portion. A resistor strain gauge is arranged near the center of the diaphragm portion, and a connection terminal portion is provided with a connection terminal connected to the resistor strain gauge. Therefore, according to the pressure sensor of the present invention, it is not necessary to provide a lead wire around the resistor strain gauge.
Therefore, the pressure sensor of the present invention has a wide range of portions for detecting pressure. Further, since the pressure sensor of the present invention does not require a lead wire, there is no place to solder the lead wire.

Further, in the pressure sensor of the present invention, since the slit is provided between the diaphragm portion of the base and the connecting terminal portion, the vibration generated in the connecting terminal portion is difficult to be transmitted to the diaphragm portion.

With the above structure, the pressure sensor of the present invention can measure pressure in a wider range than the prior art in which only a small range of pressure can be measured.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment showing a pressure sensor according to the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a pressure detecting portion of a pressure sensor according to a specific embodiment of the present invention. FIG. 2 is a vertical sectional view of a pressure sensor according to a specific embodiment of the present invention. Figure 3
FIG. 2 is a perspective view of a pressure detector used in the embodiment of FIG. 1. FIG. 4 is a vertical sectional view of a pressure sensor according to a modified embodiment of the present invention.

In the pressure sensor of the present invention, the pressure detector 23 is mounted in the case 21. The main part of the pressure detection part 23 is composed of the base body 10 and members arranged around the base body 10, and is formed of the diaphragm part 11, the connection terminal part 12, the resistor strain gauge 30, the connection terminal 14, the slit 17, and the insulating coating 13. Has been done.

The base body 10 is a metal plate, and the edge portion 16 is supported by a pedestal 18 which will be described later, and a thin plate-shaped diaphragm portion 11 which receives a substantially circular pressure F, and a portion which protrudes from the diaphragm 11 to form a case. A rectangular connection terminal portion 12 that projects to the outside of 21 and does not receive the pressure F is integrally formed. A groove slit 17 is formed between the diaphragm portion 11 and the connection terminal portion 12 on the base body 10.

The base 10 is entirely covered with an insulating coating 13 made of an insulating material such as alumina, beryllium, zirconium oxide, and enamel. The resistor strain gauge 30 is arranged near the center of the diaphragm portion 11, is formed by printing, drawing or firing on the insulating coating 13, and has a thick film shape. The connection terminal 14 is formed on the connection terminal portion 12 by printing or the like, and is connected to the resistance strain meter 30 by the conductor pattern 15.

The diaphragm portion 1 of the base body 10 as described above.
1, the connection terminal portion 12, the edge portion 16, the slit 17, the insulating coating 13 on the surface of the base body 10, the connection terminal 14, the conductor pattern 15, and the resistor strain gauge 30 constitute a pressure detection portion 23.

The shape of the diaphragm portion 11 is not limited to a circular shape, but may be an elliptical shape, a square shape, or another polygonal shape, as long as it has a large area for receiving pressure.

On the lower surface of the base 10, there is a pedestal 18 fixed via an adhesive layer. The pedestal 18 has a pressure chamber forming recess 19 for introducing pressure. A pressure supply port 20 communicates with the pressure chamber forming recess 19.

Further, the pedestal 18 is accommodated in a case 21 together with the base body 10 by an adhesive or the like, and a cap 22 is attached to the opening of the case 21.

The pressure sensor of the present invention is configured as described above, and by supplying a fluid or the like from the pressure supply port 20 into the pressure chamber forming concave portion 19, the pressure F is a part of the diaphragm portion 11 of the substrate 10 or The entire surface can be pressed and distorted, and the amount of the distortion can be detected by the resistor strain gauge 30, and further detected by the detection mechanism separately provided via the connection terminal 14.

Thus, the diaphragm portion 1 of the base 10
1, a resistor strain gauge 30 is arranged, a rectangular projecting terminal portion 12 is provided on the same substrate 10 as the diaphragm portion 11, and the diaphragm portion 11 receiving the pressure F and the terminal connecting portion 12 are the same. Since they are provided separately on the plane, the diaphragm portion 11 that receives the pressure F can be taken in a wide range, the displacement amount can be made large, and the diaphragm portion 11 can be obtained.
The influence of the strain on the terminal connection portion 12 is eliminated, and accurate pressure can be measured.

Further, in the pressure sensor of this embodiment, since the groove slit 17 is provided between the diaphragm portion 11 and the terminal connecting portion 12, the strain applied to the terminal connecting portion 12 is prevented from propagating to the diaphragm portion 11. In addition, the function of the pressure sensor with higher accuracy and higher reliability can be exhibited.

In the pressure sensor 1 of the above embodiment, the base 1
Although 0 has been disclosed as a plate-shaped member having a constant thickness, it is also preferable that the thickness of the base body 10 is different depending on the partial portions. The embodiment shown in FIG. 4 is a mode in which the thickness of the base body 10 is changed, and the diaphragm portion 40 is thin and the terminal connecting portion 41 is thick. According to the configuration of FIG. 4, since the diaphragm portion 40 is thin, it is easily deformed by pressure, and thus the sensitivity is high. On the other hand, the terminal connecting portion 41 has a large thickness and is preferable because of its high rigidity.

[0026]

As described above, according to the pressure sensor of the present invention, in the substrate deformable by the pressure to be measured, the diaphragm portion in which the resistor strain gauge is arranged near the central portion and the resistor strain gauge are provided. Since the terminal connecting portion for outputting the output signal is provided on the same substrate so as to be partially projected from the diaphragm portion, and the diaphragm portion for detecting the pressure can be provided in a wide range, it is possible to detect the pressure with high accuracy. .

Further, since the groove-shaped slit is provided between the diaphragm portion of the base and the terminal connecting portion, the distortion of the terminal portion has no influence on the diaphragm portion for detecting pressure, so that the pressure detection accuracy and reliability are improved. Has the effect of significantly improving

[Brief description of drawings]

FIG. 1 is a plan view of a pressure detector of a pressure sensor according to a specific embodiment of the present invention.

FIG. 2 is a vertical sectional view of a pressure sensor according to a specific embodiment of the present invention.

FIG. 3 is a perspective view of a pressure detector used in the embodiment of FIG.

FIG. 4 is a vertical cross-sectional view of a pressure sensor according to a modified embodiment of the present invention.

FIG. 5 is an exploded perspective view of a conventional pressure sensor.

[Explanation of symbols]

 10 Base 11,40 Diaphragm 12,12 Connection Terminal 30 Resistor Strainmeter 17Slit

Claims (2)

[Claims] 1. A resistor strain gauge in the vicinity of the center of the diaphragm of a base body integrally formed with a diaphragm portion which is deformable by a measured pressure and a connecting terminal portion which partially projects from the diaphragm portion. And a connection terminal connected to the resistor strain gauge at the connection terminal portion. 2. The pressure sensor according to claim 1, wherein a slit is provided between the diaphragm portion of the base and the connection terminal portion.