JPH10213507A - Pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure sensor capable of mutually positioning the positions of a sensor element and a body. SOLUTION: This is a pressure sensor, which is provided with a cylindrical metal made body 1 including a bottom part 11 provided with a through hole and its one side with respect to the through hole formed in hexagon head bolt shape, a sensor element 2 fitted to the body 1, and a fixed tube 4 including a separate through hole and arranged inside the cylinder of the body 1 with the element 2 provided with a resin made base 21, a pressure induction hole 22a and a collar 22b, protruding orthogonally with respect to a shaft, provided on the base edge, and also provided with a pressure induction tube 22, which is inserted into a through hole of the body 1 with the collar 22b arranged on one side fixed to the base 21, and a pressure sensor part 23 tightly fixed to the surface of the base edge of the pressure induction tube 22, has the fixed tube 4 composed with a separate screw, which is screwed to a screw provided on the tip of the pressure induction tube 22, provided in its inner or outer circumference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure sensor which is packaged in a metal body having high pressure resistance and measures the pressure of a high-pressure fluid.

[0002]

2. Description of the Related Art Conventionally, as a pressure sensor of this type, FIG.
And the configuration shown in FIG. This device has a bottom portion A2 provided with a through hole A1, and the bottom portion A2 has a through hole A1.
And a sensor element B mounted on the body A, the sensor element B being a resin base.
1, a pressure introducing hole B21 for introducing a fluid to be measured with pressure, and a flange B projecting in a direction perpendicular to the axis.
22 is provided at the base end, and a metal pressure introducing pipe B2, which is inserted through the through-hole A1 of the body A and has a flange B22 disposed on one side thereof, fixed to the base B1, and a base of the pressure introducing pipe B2. A pressure sensor unit B3 that is tightly fixed to the end surface to convert the pressure into an electric signal by blocking the pressure introduction hole B21;
Is provided.

[0003] More specifically, the body A has a female screw portion A3.
Is on the inner peripheral portion of the through hole A1, and the pressure introducing tube B2 is a male screw portion B
23 are respectively formed on the outer peripheral portions. Pressure introduction pipe B2
The male screw portion B23 is screwed to the female screw portion A3 and fixed to the body A so that the flange portion B22 is arranged on one side of the through hole A2 of the body A.

[0004]

In the above-mentioned conventional pressure sensor, the external thread B23 of the pressure introducing pipe B2 is connected to the body A.
The pressure of a fluid such as air can be measured up to a high pressure in a state where the pressure introducing pipe B2 is fixed to the body A while being screwed to each other with the female screw portion A3.

However, the position of the sensor element B in the rotational direction of the shaft of the pressure introducing hole B21 with respect to the body A is not determined, and therefore, there is a problem that the sensor element B cannot be positioned with respect to the hexagonal bolt of the body A.

The present invention has been made in view of the above problems, and has as its object to provide a pressure sensor capable of positioning the mutual position of a sensor element and a body in the direction of rotation of the axis of a pressure introduction hole B21. Is to provide.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to claim 1 has a bottom portion provided with a through hole, and one side of the through hole is formed in a hexagonal bolt shape. A cylindrical metal body, a sensor element mounted on the body, and a fixed tube having another through hole and disposed inside the cylinder of the body on the other side, wherein the sensor element is made of resin. A base, a pressure introduction hole for introducing a fluid to be measured with pressure and a flange protruding in a direction perpendicular to the axis are provided at the base end, and are inserted through the through hole of the body and disposed on one side. A metal pressure introducing pipe having a flange portion fixed to the base, and a pressure sensor section for converting pressure into an electric signal by shielding the pressure introducing hole by being tightly fixed to a base end face of the pressure introducing pipe. , Wherein the pressure sensor comprises: Is another threaded portion for threaded portion screwed which is provided at the distal end of the pressure introducing tube, are a configuration provided on the inner periphery or the outer periphery.

According to a second aspect of the present invention, in the first aspect, the pressure introducing pipe has a notch portion on an outer peripheral portion which is in contact with a projection provided from an inner peripheral wall of a through hole of the body. The configuration is provided.

According to a third aspect of the present invention, in the second aspect, the cut-out portion of the pressure introducing pipe is rotated about the axis of the pressure introducing hole and is in contact with the projecting portion of the body. Further, one of the protruding portion and the notch portion is formed so as to be inclined at a predetermined angle with respect to the other.

According to a fourth aspect of the present invention, in the first to third aspects, the contact means for making close contact with the flange of the pressure introducing pipe and the bottom of the body respectively surrounds the pressure introducing pipe. The configuration is provided.

[0011]

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

Reference numeral 1 denotes a body, which is formed of a metal such as steel or stainless steel and has a bottom portion 11 and is formed in a tubular shape having a hexagonal bolt 1a on one side and a male screw on the other side. A first through hole 12 is provided at the center position, and a protruding portion 12a projects from an inner peripheral wall of the first through hole 12 as shown in FIG. A first concave portion 13 is provided on one side of the first through hole 12 and a second concave portion 14 is provided on the other side, and the second concave portion 14 has a step portion 14a to form the inside of the cylinder. In addition, the first recess 13 and the second recess 1
4 are concentrically formed in communication with the first through holes 12.

A sensor element 2 includes a base 21, a pressure introducing pipe 22, and a pressure sensor section 23. The base 21 is formed of an insulating resin into a substantially rectangular tube shape, the inside of which forms a housing space, and is housed in the first recess 13.

The pressure introducing pipe 22 is made of Kovar or FeNi.
A flange 22b, which is formed in a substantially cylindrical shape by a metal such as an alloy, is provided with a pressure introducing hole 22a for introducing a fluid to be measured with pressure, and projects in a direction perpendicular to the axial direction
Is provided at the base end, and the flange 22b is fixed to the base 21 by integral molding. Further, a screw portion, that is, a male screw portion 22c is formed on the outer peripheral portion of the distal end portion, and as shown in FIG. 4, a notch portion 22d is provided on the outer peripheral portion by being cut out along the axial direction.

Here, a predetermined amount of clearance is provided between the inner diameter of the first through hole 12 and the outer diameter of the pressure introducing pipe so that the flange portion 22b is disposed on one side of the first through hole 12 of the body 1. In the state provided, it is inserted into the first through hole 12. When the rotation is made about the axis of the pressure introducing hole 22a, the notch 22d comes into contact with the protruding portion 12a protruding from the inner peripheral wall of the first through hole 12 of the body 1, and the protruding portion 12a is brought into contact with the protruding portion 12a. It is formed so as to be positioned at a predetermined position with respect to the body 1 in a state of being inclined at a predetermined angle with respect to the notch 22d.

The pressure sensor section 23 is provided with a silicon diaphragm 23a and a glass pedestal 23b having a shaft hole 23c. The silicon diaphragm 23a forms a strain gauge by disposing a piezo resistor (not shown). ,
Converts fluid pressure into an electrical signal. Glass pedestal 23b so that silicon diaphragm 23a shields shaft hole 23c.
And the glass pedestal 23
The other surface of b is tightly fixed to the base end surface 22e of the pressure introducing tube 22 by soldering in a state where the axes of the pressure introducing hole 22a and the shaft hole 23c of the pressure introducing tube 22 are aligned with each other. That is, the pressure introduction hole 22 a is shielded by the pressure sensor unit 23.

Reference numeral 3 denotes a contacting means, which comprises an O-ring 31 and a washer 32 made of a metal formed in a ring shape. The O-ring 31 is formed in a ring shape with a circular cross section by using synthetic rubber or synthetic resin. When pressed, elastic deformation occurs. O-ring 31 and washer 32
2 and the flange 22b and the body 1
And is in close contact with each other.

Reference numeral 4 denotes a fixed tube, which is formed of a metal such as iron or stainless steel and has a cylindrical shape having a second through hole 41, and another threaded portion, that is, a female threaded portion 42 having an inner peripheral portion on one end side. Another flange 43 protrudes in the direction perpendicular to the axial direction, and an outer peripheral portion on the other end side, and a slit 44 is provided in the other flange 43, respectively. The female screw portion 42 is disposed in the second concave portion 14 inside the cylinder on the other side of the body 1 and inserts a tool into the slit 44 and rotates it.
Is rotated and screwed together with the male screw portion 22 c, and the second through hole 41 communicates with the first through hole 12 of the pressure introducing pipe 22.

The terminal 5 is fixed to the base 21 and the base 2
1 has an internal terminal disposed inside and a bent external terminal disposed outside, and the internal terminal is electrically connected to an electrode (not shown) provided on the silicon diaphragm 23a by wire bonding. It is connected.

The printed circuit board 6 is fixed to the first concave portion 13 of the body 1 by a ceramic substrate on which a circuit is formed, and is electrically connected to the pressure sensor section 23 by inserting and soldering the terminal 5. Connected. The terminal block 7 is formed by simultaneously molding three connector terminals 71, and the connector terminals 71 are connected to the terminals 5 via the printed circuit board 6.

The connector 8 is made of a synthetic resin and has a rectangular tube-shaped attaching / detaching portion 81 and a cylindrical pedestal portion 82 having a diameter larger than the outer shape of the attaching / detaching portion 81. At this time, the connector terminal 71 of the terminal block 7 projects into the cylinder of the attaching / detaching portion 81 and is led out.

Here, in a state where the pressure introducing pipe 22 is surrounded, the washer 32 is located between the flange 22 b of the pressure introducing pipe 22 and the O-ring 31, and the O-ring 31 is located between the washer 32 and the bottom 11 of the body 1. The pressure introducing pipe 22 is inserted through the first through-hole 12 of the body 1 so as to be disposed between the pressure introducing pipes. Projection 12a
And the notch 22d are engaged with each other to form the pressure introduction hole 2
The mutual position of the body 1 and the sensor element 2 in the rotation direction of the shaft 2a is determined, and the fixed tube 4 is disposed in the second concave portion 14 of the body 1.

When the fixed tube 4 is rotated, the female screw portion 42 is rotated and screwed with the male screw portion 22c of the pressure introducing tube 22 in a state where another flange portion 43 and the step portion 14a of the body 1 are in contact with each other.
The pressure introducing pipe 22 is tightened. The sensor element 2 includes a flange 22b and a male screw 22c of the pressure introducing pipe 22.
With the body 11 sandwiching the bottom 11 of the body 1
Fixed to

At this time, as described above, the protrusion 12a
Is provided on the body 1 so that the pressure introducing pipe 22 is prevented from rotating by the notch 22d abutting on the protrusion 12a, and the protrusion 12a is inclined by a predetermined angle with respect to the notch 22d. As a result, even if the sensor element and the body are displaced from each other due to the clearance, the sensor element 2 is fixed at a predetermined position with respect to the body 1 in abutting opposition. Next, the O-ring 31 is pressed and uniformly elastically deformed, and the contacting means 3 comes into close contact with the flange 22 b and the bottom 11 of the body 1, and comes into contact with the outer peripheral surface of the pressure introducing pipe 22.

The operation of this will be described. The high-pressure fluid such as air is introduced into the pressure introducing hole 22 a of the pressure introducing tube 22 via the second through hole 41 of the fixed tube 4. Pressure introduction pipe 2
2 is fixed to the body 1, the O-ring 31 is pressed and the outer peripheral surface of the pressure introducing pipe 22 and the bottom 11 of the body 1 are pressed.
Of the pressure introducing pipe 22 so that the pressure sensor 23 contacts the pressure introducing hole 22a.
2e. Therefore, the fluid applies the pressure to the pressure sensor unit 23 without leaking from the pressure introduction hole 22a to the outside.

When the pressure of the fluid is applied to the pressure sensor 23, the silicon diaphragm 23a formed in the pressure sensor 23 bends in proportion to the difference between the pressure of the fluid and the atmospheric pressure. Then, the resistance value of the piezoresistor formed on the silicon diaphragm 23a changes in proportion to the magnitude of the deflection, and outputs this resistance value to the terminal 5 as an electric signal, and the amplification element ( (Not shown), and outputs the amplified signal to the connector terminal 71 to measure the pressure of the fluid.

In the pressure sensor according to the embodiment, as described above, the external thread 22c is provided on the outer peripheral portion of the distal end of the pressure introducing pipe 22, and the internal thread 42 screwed with the external thread 22c is attached to the fixed pipe 4 as shown in FIG. The female threaded portion 42 of the fixed tube 4 disposed inside the cylinder of the body 1 in a state where the sensor element 2 is inserted into the through hole of the body 1 and is positioned with respect to the hexagon bolt 1a. Is pressure introduction pipe 2
2 is screwed together with the external thread portion 22c of the pressure introduction pipe 2
The sensor element 2 and the body 1 can be positioned relative to each other in the direction of rotation of the axis of the pressure introducing hole 22a by fixing the sensor element 2 to the body 1 with the bottom 11 of the body 1 sandwiched therebetween.

A notch 22 abutting on a protruding portion 12 a protruding from the inner peripheral wall of the first through hole 12 of the body 1.
d is provided on the outer peripheral portion of the pressure introducing tube 22, so that the female screw portion 42 of the fixed tube 4 becomes the male screw portion 22 c of the pressure introducing tube 22.
Is screwed into each other, the notch 22d is
Therefore, the rotation of the pressure introducing pipe 22 is prevented, and the positioning between the sensor element 2 and the body 1 can be easily performed without using a positioning jig.

Further, since the protruding portion 12a of the body 1 is formed to be inclined at a predetermined angle with respect to the notch 22d of the pressure introducing pipe 22, the inner diameter of the through hole of the body 1 and the outer diameter of the pressure introducing pipe 22 are reduced. Even if the positions of the sensor element 2 and the body 1 are shifted from each other due to the clearance between the two, when the protruding portion 12a and the notch portion 22d abut, the sensor element 2 is fixed to the body 1 at the abutting position. The position is fixed so that the body 1 and the sensor element 2 can be positioned at any desired position regardless of the clearance.

A flange 22b is provided at the base end of the pressure introducing pipe 22, and the flange 22b and the body 1
Is provided between the flange portion 22b and the bottom portion 11 in a state where the contact portion 3 surrounds the pressure introducing tube 22 and is pressed and adhered to the bottom portion 11 in a state where the pressure introducing tube 22 is surrounded. The pressure introducing pipe 22 can be hermetically sealed from the outside without contacting the outer peripheral surface of the pressure transmitting tube 22 and leaking fluid through the outer peripheral surface.

In the present embodiment, the male screw portion 22c is provided on the outer peripheral portion of the distal end of the pressure introducing tube 22 and the female screw portion 42 is provided on the inner peripheral portion of one end of the fixed tube 4. At one end outer peripheral portion, a female screw portion 42 is connected to the pressure introducing pipe 2.
It may be provided on each of the inner peripheral portions of the two distal ends, and is not limited.

[0032]

According to the first aspect of the present invention, a screw portion is provided at the tip of the pressure introducing tube, and another screw portion to be screwed with the screw portion is provided on the inner or outer peripheral portion of the fixed tube. , The sensor element is inserted through the through hole of the body and the hexagonal bolt 1a
When another threaded part of the fixed pipe arranged inside the cylinder of the body is screwed with the threaded part of the pressure introduction pipe in a state where it is positioned with respect to the body, the pressure introduction pipe sandwiches the bottom of the body. Fixed to the body, the mutual position of the sensor element and the body in the rotation direction of the axis of the pressure introduction hole,
Positioning can be done.

According to a second aspect of the present invention, in addition to the effect of the first aspect, a notch portion which comes into contact with a projection projecting from an inner peripheral wall of the through hole of the body is provided at an outer peripheral portion of the pressure introducing pipe. When the other threaded portion of the fixed tube is screwed with the threaded portion of the pressure introducing tube, the notch comes into contact with the projecting portion, so that the rotation of the pressure introducing tube is prevented, and the positioning jig is provided. The positioning between the sensor element and the body can be easily performed without using the sensor element.

According to a third aspect of the present invention, in addition to the effect of the second aspect, one of the projecting portion of the body and the cutout portion of the pressure introducing pipe is formed to be inclined at a predetermined angle with respect to the other. Therefore, even if the position of the sensor element and the body are displaced from each other due to the clearance between the inner diameter of the through hole of the body and the outer diameter of the pressure introducing pipe, if the projection and the notch contact each other, the contact At the contact position, the sensor element is fixed at a predetermined position with respect to the body, and the body and the sensor element can be positioned at a desired position regardless of the clearance.

According to a fourth aspect of the present invention, in addition to the effects of the first to third aspects, the flange is provided at the base end of the pressure introducing pipe, and is in close contact with the flange and the bottom of the body. Since the contacting means is provided, the contacting means is sandwiched and pressed between the flange portion and the bottom in a state of surrounding the pressure introducing pipe and is brought into close contact therewith, and comes into contact with the outer peripheral surface of the pressure introducing pipe through the outer peripheral surface thereof. Thus, the pressure introducing pipe can be hermetically sealed from the outside without air leakage.

[Brief description of the drawings]

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

FIG. 2 is a right side view of the same.

FIG. 3 is a left side view of the same.

FIG. 4 is a cross-sectional view of the pressure introduction pipe in a state where the pressure introduction pipe is inserted into a through hole of a body.

FIG. 5 is a front sectional view showing a conventional example.

FIG. 6 is a right side view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 11 Bottom part 12 First through hole (through hole) 12a Projection part 14 Second concave part (inside of cylinder) 2 Sensor element 21 Base 22 Pressure introduction pipe 22a Pressure introduction hole 22b Flange part 22c Male thread part (screw part) 22d Cut Notched portion 22e Base end surface 23 Pressure sensor portion 3 Adhesion means 4 Fixed pipe 41 Second through hole (another through hole) 42 Female thread (another screw)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hirohisa Tanaka 1048 Kazumasa Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd.

Claims (4)

[Claims] 1. A cylindrical metal body having a bottom provided with a through hole and having a hexagonal bolt on one side with respect to the through hole, a sensor element mounted on the body, and a separate through hole. A fixed tube having a hole and disposed inside the cylinder of the body on the other side, wherein the sensor element comprises:
A resin base, a pressure introduction hole for introducing a fluid to be measured with pressure, and a flange protruding in a direction perpendicular to the axis are provided at the base end portion, and are inserted through the through hole of the body to one side. A pressure introducing pipe made of metal having a flange portion fixed to a base, and a pressure sensor which is closely fixed to an end face of a base end portion of the pressure introducing pipe and converts pressure into an electric signal by shielding the pressure introducing hole. A pressure sensor, wherein the fixed tube is provided with another screw portion screwed with a screw portion provided at a tip portion of the pressure introduction tube at an inner peripheral portion or an outer peripheral portion. Pressure sensor characterized by the above-mentioned. 2. The pressure as set forth in claim 1, wherein the pressure introducing pipe has a cutout portion provided on an outer peripheral portion thereof, the cutout portion being in contact with a projecting portion projecting from an inner peripheral wall of a through hole of the body. Sensor. 3. A position where the notch of the pressure introducing pipe rotates around the axis of the pressure introducing hole and abuts on the protruding portion of the body, and one of the protruding portion and the notch is provided. 3. The pressure sensor according to claim 2, wherein the pressure sensor is formed to be inclined at a predetermined angle with respect to the other. 4. The pressure as set forth in claim 1, wherein said pressure-introducing tube is provided with contact means for closely adhering to a flange portion of said pressure-introducing tube and a bottom portion of said body, respectively. Sensor.