JPH064299Y2 - Metal diaphragm type pressure sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a metal diaphragm type pressure sensor, and in particular, a hollow portion formed in a housing is divided into two parts by a metal diaphragm, and one of them is a pressure receiving side, and The other relates to a metal diaphragm type pressure sensor on the pressure detection side.

[Prior art]

The conventional metal diaphragm type pressure sensor of this type has a second
As shown in the figure, a pressure-receiving side housing 12 having a pressure-receiving port 11 and a detection-side housing 14 connected to the detection portion 13 are superposed on each other with a metal diaphragm 15 sandwiched therebetween. The outer peripheral edge of the diaphragm 15 is welded like a welded portion 19 shown in the figure, so that the diaphragm 15 is integrally joined.

Then, the pressure receiving side housing 12 and the detection side housing 14
The hollow portion 18 formed between the metal diaphragm 15 and
Is divided into upper and lower parts, the lower side of the metal diaphragm 15 becomes a pressure receiving side which is continuous with the pressure receiving port 11, and the metal diaphragm 1
The upper side of 5 is connected to the detection unit 13 and is the pressure detection side in which the oil 20 is sealed.

[Problems to be solved by the invention]

However, in such a conventional device, the welded portion 19 (that is, the joined portion of the metal diaphragm 15 to the housings 12 and 14) supporting the metal diaphragm 15 which is the pressure receiving element of the pressure sensor is in contact with the atmosphere side. Therefore, the welded portion (joint portion) 19 has a housing 1
Since a pressure difference between the pressures in 2 and 14 and the atmospheric pressure is applied, particularly when high pressure is handled, the large pressure difference from the atmospheric pressure acts as a load and is applied to the welded portion (joint portion) 19, and this portion There is a problem that not only the joint strength of No. 1 is threatened but also fatigue is caused to shorten the life.

An object of the present invention is to provide a metal diaphragm type pressure sensor which solves the above-mentioned problems of the conventional one and can prevent a pressure load from being applied to a joint portion of the metal diaphragm to the housing. It is a thing.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention forms a recess in one side of the pressure receiving housing, and screws the detection side housing into the opening of the recess to connect the detection side housing and the A hollow portion that is hermetically sealed with the pressure receiving housing is formed, and a pressure receiving opening that opens the hollow portion to the outside is formed in the pressure receiving housing, and a detection opening that opens the hollow portion to the outside in the detection housing. With each of which is bored, the peripheral portion of the metal diaphragm is welded to the hollow-side surface of the detection-side housing, and the opening on the hollow-portion side of the detection port is closed with this metal diaphragm,
A detector in which a detector is connected to the opening on the outside of the detector to form a fluid chamber sealed between the detector and the metal diaphragm, and a pressure transmission medium is enclosed in the fluid chamber. Is.

[Action]

By adopting the above-mentioned means in this invention, no pressure load is applied to the joint portion of the metal diaphragm.

〔Example〕

 An embodiment of the present invention shown in the drawings will be described below.

FIG. 1 shows an embodiment of a metal diaphragm type pressure sensor according to the present invention. This metal diaphragm type pressure sensor includes a pressure receiving side housing 2, a detection side housing 4 and a metal diaphragm 5. There is.

A recess 2a having an appropriate depth is formed on one side (upper surface side) of the pressure receiving side housing 2, and an appropriate screw 6 is screwed on the inner surface side of the recess 2a. , Recess 2
A pressure receiving port 1 penetrating to the other side (bottom surface side) of the pressure receiving side housing 2 is formed in the center of the bottom surface side of a.

Further, the detection side housing 4 has a disk shape, and has a screw 7 corresponding to the screw 6 of the recess 2a on the outer peripheral surface.
And a detection port 4a penetrating from one side (upper surface side) to the other side (lower surface side).

Then, the screw 7 of the detection side housing 4 configured as described above is screwed into the screw 6 of the recess 2a of the pressure receiving side housing 2, and the detection side housing 4 is attached to the pressure receiving side housing 2 to form the concave portion. The opening of the place 2a is closed,
A sealed hollow portion 8 is formed between the detection-side housing 4 and the pressure-receiving housing 2, and the hollow portion 8 is formed through a pressure-receiving port 1 of the pressure-receiving housing 2 and a detection port 4a with the detection-side housing 4. It is open to the outside.

The metal diaphragm 5 has a thin disk shape, and its peripheral portion is fixed to the surface of the detection side housing 4 on the hollow portion 8 side through a ring-shaped support member 4b. In this case, between the support member 4b and the detection side housing 4, and between the support member 4 and the metal diaphragm 5
The two are fixed together by welding. Therefore, the welded portion 9 of the metal diaphragm 5 to the detection side housing 4 is located inside the hollow portion 8 that is shielded from the atmosphere. The opening of the detection port 4a on the hollow portion 8 side is closed by the metal diaphragm 5 fixed to the detection side housing 4 in this manner.

On the other hand, a bag-shaped detection unit 3 is connected to the other opening (upper surface side) of the detection port 4a of the detection side housing 4.

By thus fixing the metal diaphragm 5 to the lower surface side of the detection-side housing 4 and connecting the detection portion 3 to the upper surface side, the fluid chamber A sealed between the metal diaphragm 5 and the detection portion 3 is formed. A pressure transmitting medium 10 such as oil is enclosed in the fluid chamber A formed.

Next, the operation of the above will be described.

First, when pressure in the direction of lifting the metal diaphragm 5 is applied to the metal diaphragm 5 from the pressure receiving port 1, this pressure causes the metal diaphragm 5 to be displaced upward in the drawing, and the displacement of the metal diaphragm 5 via the pressure transmission medium 10. The pressure is transmitted to the detection unit 3, and the pressure is detected by the detection unit 3.

In this case, the metal diaphragm 5 is located in the hollow portion 8 that is shielded from the atmospheric pressure, and furthermore, the pressure on the detection side by the pressure transmission medium 10 such as oil that acts on the inside of the metal diaphragm 5 and the action on the outside. Since the pressure on the pressure receiving side is balanced, the welded portion (joint portion) 9 of the metal diaphragm 5 is
There will be no pressure load on.

Further, the detection side housing 4 to which the metal diaphragm 5 is fixed is screwed into the recess 2 a of the pressure receiving side housing 2.
Since it is fixed by the action of 7, it can be attached and detached, which is very advantageous in terms of maintenance.

[Effect of device]

By having the above-mentioned structure according to the present invention, it is possible to prevent a pressure load from being applied to the joint portion of the metal diaphragm to the housing, so that there is no concern about the joint strength and fatigue of this portion, and the life is greatly extended. You will be able to do it. Further, since the detection side housing to which the metal diaphragm is fixed is screwed to the pressure receiving side housing so as to be detachable, it has an excellent effect such as being very advantageous in terms of maintenance.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a metal diaphragm type pressure sensor according to the present invention, and FIG. 2 is a sectional view showing an example of a conventional metal diaphragm type pressure sensor. 1, 11 ...... Pressure receiving port 2, 12 ...... Pressure receiving housing 3, 13 ...... Detection part 4, 14 …… Detection side housing 5, 15 …… Metal diaphragm 6, 7 …… Screw 8, 18 …… Hollow part 9, 19 ... Welded part (joint part) 10, 20 ... Pressure transmission medium (oil) 2a ... Recess, 4a ... Detection port, 4b ... Support member, A
...... Fluid chamber

Claims (1)

[Scope of utility model registration request] 1. A recess (2) on one side of the pressure receiving housing (2).
a) is drilled, and the detection side housing (4) is screwed into the opening of the recess (2a) to seal between the detection side housing (4) and the pressure receiving side housing (2). And a pressure receiving port (1) for opening the hollow portion (8) to the outside, and the detection side housing (4) with the pressure receiving port (1). Each of the detection ports (4a) for opening (8) to the outside is bored, and the peripheral portion of the metal diaphragm (5) is welded to the hollow portion (8) side surface of the detection side housing (4). The detection opening (4a) is formed by the metal diaphragm (5).
The opening on the hollow part (8) side is closed, and the detection part (3) is connected to the opening on the outer side of the detection port (4a) to detect the detection part (3) and the metal diaphragm ( 5) A metal diaphragm type pressure sensor, characterized in that a fluid chamber (A) is formed between the fluid chamber (A) and the pressure transmission medium (10) enclosed in the fluid chamber (A).