JPH0843233A - Pressure sensor - Google Patents

Abstract

PURPOSE:To provide a pressure sensor pressure detecting accuracy of which is not deteriorated by fixing a connector to the body of the sensor by welding by using a metallic fixing member. CONSTITUTION:The pressure sensor is provided with a metallic body 1, pressure sensor chip 2 mounted on the body 1, and resin connector 7 which is fixed to the body 1 so that signals can be inputted and outputted between the chip 2 and external equipment through the connector 7. When the connector 7 is fixed to the body 1, a metallic fixing member 9 is fixed to the body 1 by laser welding while the connector 7 is held by the member 9 between the member 9 and body 1. Therefore, the pressure sensor can detect pressures with accuracy, because stresses are hardly applied to the body 1 and no stress acts on the strain gauge of the chip 2 mounted on the body 1. In addition, the pressure sensor can be constituted in a waterproof structure, because the space between the body 1 and member 9 is sealed by laser welding and, at the same time, the space between the connector 7 and member 9 is sealed with a sealing member 9.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a pressure sensor having a connector.

[0002]

2. Description of the Related Art Conventionally, as a pressure sensor of this type, FIG.
There is a configuration shown in. This is a metal body A and a pressure sensor chip B mounted on the body A.
And a resin connector C fixed to the body A so that signals can be input and output between the pressure sensor chip B and external equipment.
And are equipped with.

More specifically, this pressure sensor is designed so that when pressure is applied to the pressure sensor chip B which is a strain gauge, the pressure is detected by the strain at that time. State The body A is that the recess A ₁ provided at the center, accommodates the constituent members for detecting the pressure such as a pressure sensor chip B, was fitted to the connector C to the opening of the concave portion A ₁ Then, the peripheral edge portion A ₂ of the opening is deformed by pressure from the outside, so that the connector C is caulked and fixed by the peripheral edge portion A ₂ .

[0004]

In the above-mentioned conventional pressure sensor, the connector C is a recess formed in the body A.
Since the peripheral portion A ₂ of the opening of A ₁ by pressure deformation from the outside, are caulked and fixed to the body A, the pressure sensor residual stress upon the pressure deformation is attached to the body A It may not be able to detect the accurate pressure due to the strain gauge on the tip B.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a pressure sensor which does not adversely affect pressure detection accuracy by fixing a connector to a body.

[0006]

In order to solve the above-mentioned problems, according to a first aspect of the present invention, a metal body, a pressure sensor chip mounted on the body, a pressure sensor chip and an external device are provided. A connector made of resin fixed to the body so that signals can be input and output between the body and a metal connector that is welded and fixed to the body with the connector held between the body and the connector. The fixing member is provided.

According to a second aspect of the present invention, in the first aspect, a sealing member for sealing between the fixing member and the connector is attached.

According to a third aspect of the present invention, in the first aspect, the fixing member has a fitting portion that fits into the connector and is positionally regulated.

[0009]

According to the first aspect of the present invention, when fixing the connector to the body, the fixing member made of metal is sandwiched between the fixing member made of resin and the body made of metal, and the fixing member is fixed. Since it is only welded and fixed to the body, unlike the conventional example in which a pressure deformation force is applied to the body to fix it by caulking, stress is less likely to be applied to the body.

According to the second aspect, the body and the fixing member can be sealed by welding and fixing,
A waterproof structure can be obtained by sealing between the connector and the fixing member with a sealing member.

According to the third aspect of the present invention, the position of the fixing member is regulated only by fitting the fitting portion of the fixing member to the connector, and welding fixing is easy.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes a body, which is made of metal such as steel or stainless steel and is formed in a hexagonal bolt shape by providing a concave portion 1a having a concentric circular step on one surface side, and the concave portion 1a has an opening portion formed by a cylindrical portion 1b. In addition to being formed, an inflow hole 1c into which an object whose pressure is to be measured flows in is provided at the center position so as to penetrate to the outside.

Reference numeral 2 is a pressure sensor chip, and a strain gauge is formed by arranging a diffusion resistance on a silicon diaphragm. As shown in FIG. 3, the pressure sensor chip 2 is mounted on a glass pedestal 2b joined to a metal pedestal 2a by being joined to the metal pedestal 2a by laser welding and then placed in the recess 1a of the body 1. Fixed.

A printed circuit board 3 is provided with circuits for temperature compensation, amplification, etc., and the pressure sensor chip 2 is positioned in a square hole 3a provided in the center of the printed circuit board and fixed to the concave portion 1a of the body 1 with a silicone adhesive. In addition, the pressure sensor chip 2 is connected by wire bonding.

Reference numeral 4 denotes a shield cap, which is formed of a metal material in a circular box shape, and as shown in FIG. 4, a through-hole capacitor 4a is provided in a hole formed in the bottom of the shield cap.
It is fixed in the concave portion 1a of 1. At this time, the terminal piece 4b previously soldered to the printed circuit board 3 is passed through the feedthrough capacitor 4a and fixed by soldering.

Reference numeral 5 denotes a terminal block, which is formed by simultaneously molding the connector terminals 5 a and is mounted on the shield cap 4. At this time, the terminal piece 4b is soldered to the connecting portion 5b provided on the connector terminal 5a.

6 is a waterproof cap, made of rubber material,
It is formed in a flat plate shape having a through hole 6a, and the connector terminal 5a is inserted into the through hole 6a and mounted on the terminal block 5.

Reference numeral 7 denotes a connector, which is made of a synthetic resin and has a cylindrical tubular shape in which a detachable portion 7a having a rectangular tubular shape and a circular step portion 7c having a diameter larger than the outer shape of the attachable portion 7a are connected to one end of the attachable portion 7a. Pedestal
7b, and a circular step portion 7c of the pedestal portion 7b is provided with a circular ring-shaped groove 7d. This connector 7
The pedestal portion 7b is fitted inside the concave portion 1a of the body 1, and at this time, the connector terminal 5a of the terminal block 5 is projected and drawn into the cylinder of the attachment / detachment portion 7a, and the connector terminal 5a is waterproof. The cap 6 has a waterproof structure, and the circular step portion 7c is flush with the end surface of the cylindrical portion 1b of the body 1.

Reference numeral 8 denotes a sealing member, which is formed of a rubber material in a ring shape and is fitted into the groove 7d of the connector 7. At this time, the top of the sealing member 8 is slightly protruding from the groove 7d.

Reference numeral 9 denotes a fixing member, which is made of a metal material and has a through hole (fitting portion) formed in the center thereof in conformity with the outer shape of the detachable portion 7a of the connector 7.
It is formed in a disc shape with 9a, and its through hole (fitting part) 9a
By attaching the to the attachment / detachment portion 7a, the circular stepped portion of the pedestal portion 7b
7c Specifically, it is arranged on the sealing member 8 in a position-regulated state. The fixing member 9 is sandwiched between the pedestal portion 7b and the concave portion 1a of the body 1 so that the sealing member 8 is pushed into the groove 7d, and the fixing member 9 is located at the same height as the circular step portion 7c. The end surface of the cylindrical portion 1b is irradiated with laser light and fixed by welding. At this time, the body 1 and the fixing member 9 are laser welded, the connector 7 and the fixing member 9 are sealing members 8,
Each is sealed to form a waterproof structure.

The above-mentioned pressure sensor is used by detachably attaching a detachable portion connected to an external device to the detachable portion 7a of the connector 7, and an object whose pressure is to be measured flows into the body 1 from the outside. When flowing into the hole 1c, the pressure is applied to the pressure sensor chip 2 which is a strain gauge, and the pressure is detected by the strain at that time, and the detection output signal and the input signal from the external device are the connector 7 It is transmitted via the connector terminal 5a.

In such a pressure sensor, as described above, when the connector 7 is fixed to the body 1, the resin-made connector 7 is fixed by the metal fixing member 9 to the metal body.
1 and the fixing member 9
Unlike the conventional example in which pressure deformation force is applied to the body due to caulking fixation, stress is not easily applied to the body 1, and therefore the pressure sensor chip mounted on the body 1 No stress acts on the strain gauge of 2 and accurate pressure can be detected.

Since the body 1 and the fixing member 9 are sealed by laser welding and the connector 7 and the fixing member 9 are sealed by the sealing member 8, a waterproof structure can be obtained.

Further, the fixing member 9 is regulated in position only by fitting the through hole (fitting portion) 9a thereof into the attaching / detaching portion 7a of the connector 7, and the fixing at the time of laser welding is easy.

In this embodiment, the sealing member 8 is arranged on the circular step 7c of the pedestal 7b of the connector 7, but as shown in FIG. 5, it is arranged on the outer surface of the pedestal 7b. You can set it up,
In this case, the sealing member 8 is pushed into the inner surface of the cylindrical portion 1b of the body 1 to seal between the connector 7 and the fixing member 9.

The sealing member 8 may be omitted if it is not necessary to have a waterproof structure, and the fixing member 9 may be provided with a through hole (fitting portion) 9a if the position can be regulated by another means. It may not be provided.

[0028]

According to the first aspect of the present invention, when the connector is fixed to the body, the resin-made connector is sandwiched between the metal-made fixing member and the metal-made fixing member. Unlike the conventional example in which a pressure deformation force is applied to the body due to caulking fixation, it is difficult to apply stress to the body because it is only fixed by welding to the body, so stress is also applied to the pressure sensor chip mounted on the body. Does not work and can detect accurate pressure.

According to the second aspect, in addition to the effect of the first aspect, since the body and the fixing member can be sealed by welding and fixing, the connector and the fixing member are sealed. A waterproof structure can be obtained by sealing with a member.

According to the third aspect of the invention, in addition to the effect of the first aspect, the position of the fixing member is regulated only by fitting the fitting portion of the fixing member to the connector, and welding fixing is easy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same.

FIG. 3 is a cross-sectional view showing a portion of the above pressure sensor chip.

FIG. 4 is a cross-sectional view showing a connected state of the above-mentioned printed board and shield cap.

FIG. 5 is a cross-sectional view showing a modification example of the above.

FIG. 6 is a sectional view showing a conventional example.

[Explanation of symbols]

 1 Body 2 Pressure sensor chip 7 Connector 8 Sealing member 9 Fixing member 9a Mating part (more details: through hole)

Claims (3)

[Claims] 1. A metal body, a pressure sensor chip attached to the body, and a resin connector fixed to the body so as to input and output signals between the pressure sensor chip and an external device. A pressure sensor provided with a metal fixing member that is welded and fixed to the body in a state where the connector is sandwiched between the body and the pressure sensor. 2. The pressure sensor according to claim 1, further comprising a sealing member that seals between the fixing member and the connector. 3. The pressure sensor according to claim 1, wherein the fixing member has a fitting portion which is fitted into the connector and whose position is regulated.