JPH03239935A - Constitution of pressure sensor and its assembling method - Google Patents

Abstract

PURPOSE:To eliminate the propagation of cracking and to increase the strength of connection by providing a pressure-sensitive element with a step which is thick enough for strength, fitting a stepped joint in contact, and forming a weld zone which is deep enough for strength while exceeding the step. CONSTITUTION:The joint 2 is provided with the step part 11 to have surfaces 11a-11d, the pressure-sensitive element 1 is provided with the step part 12 to have surfaces 12a-12d, and the thickness of the vertical surface 12a is set to such sectional area that the element 1 and joint 2 do not separate with ease even when pressure is applied. Then the step parts 11 and 12 are set in an abutting state to form a weld zone 8 between the vertical surfaces 11a and 12a, a gap 13 which is not welded is formed between the step parts 11 and 12, and the weld zone 8 intersects the horizontal surfaces 12b and 11b at right angles and extend to specific depth beyond the horizontal surfaces. Consequently, the unwelded zone gap (rupture surface) becomes parallel to the weld zone 8 and intersects a cracking generation direction 10 at right angles, so the cracking is prevented from being propagated with pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure sensor. More specifically, the present invention relates to a connection structure between a pressure-sensitive element of a pressure sensor and a joint, and a method for assembling the same.

(Prior Art) A connection structure between a pressure-sensitive element and a joint of a conventional pressure sensor will be described with reference to FIG. 4 of the accompanying drawings.

A pressure-sensitive element 1 with a pressure-receiving element g is fixed to the end of the joint 2.

The joint f-2 has a pressure introduction hole 3 in the center, and also has a threaded portion 4 and a nut portion 15 for attachment to the device to be measured.

Usually, the pressure sensitive element 1 and the joint 2 are connected by welding. It is necessary to perform welding to maintain sufficient sealing performance so that the pressure medium introduced through the pressure introduction hole 3 does not leak to the outside, and to maintain sufficient strength so as not to cause destruction under the specified pressure. There is. Laser welding, electron beam welding, etc. are usually used as welding methods that can achieve this type of purpose, as they provide sufficient sealing performance and strength, and have less thermal damage to the surrounding area. The fourth welding method
As shown in Figure (B), a vertical surface 6a provided on the joint 2,
The legs 7 of the pressure-sensitive element 1 are arranged on the L-shaped stepped portion 6 having a horizontal surface 6b. The horizontal surface 7b of the leg 7 is located on the horizontal surface 6b of the L-shaped stepped portion 6, and the vertical surface 7a It faces the abutment of the vertical surface 6a of the character-shaped stepped portion 6. Welding 8 is performed on this abutting surface to assemble the joint 2 and the pressure sensitive element 1.

The problems to be solved by the present invention will be explained below with reference to these drawings.

(Problem to be Solved by the Invention) As a method for welding the pressure-sensitive element 1 and the joint 2, first, with both members fitted closely together, the surfaces 6a and 7a to be welded are butted against each other, and the circumference is The essential conditions for performing welding 8 along the welding line are: (1) sealing performance between the pressure sensitive element 1 and the joint 2 (2) maintenance of the strength of the welded portion 8. Therefore, welding requires continuous and defect-free welding in order to satisfy . Welding without cracks or defects is required.

In the welded structure of the conventional example already described, as shown in FIG. It extends into the weld surface. Therefore, when pressure is applied by an external force, the pressure sensitive element 1 and the joint 2 are separated, and the gap 9 becomes larger. The direction in which the crack in the gap 9 propagates coincides with the direction 10 in which the welded portion 8 is ruptured by pressure. Therefore, the gap 9 is equivalent to a crack in the weld 8 when viewed from the weld 8 itself, and therefore, when pressure is applied, the weld 8 is likely to propagate and break, etc. There was a problem. Therefore, in order to eliminate the above-mentioned problem, it is possible to use a method of digging the depth of the weld 8 to reduce the stress applied to the weld 8 as shown in FIG. In addition, there are various problems such as prevention of welding defects due to excessive temperature rise during welding, and it is technically difficult to easily overcome this problem.In the present invention, the above-mentioned The purpose is to overcome various problems, and the means for achieving this purpose will be described below.

(Means for Solving the Problems) The means for achieving the above object are as follows, and the details thereof will be explained below based on embodiments of the present invention. As shown in FIGS. 1 and 2(B), in a pressure sensor in which a pressure sensitive element 1 is mounted on one side of a joint 2, a plurality of vertical surfaces 11a are provided on one side.

a joint 2 provided with a stepped portion 11 having a horizontal surface 11b and a lid; and a stepped portion 14 of the joint on the surface facing the joint 2.
A pressure sensitive element 1 is provided with a stepped portion 12 having a plurality of vertical surfaces 12a, 12c and horizontal surfaces 12b, 12d formed in the same manner as shown in FIG. ll respective vertical surfaces 11a, llc, 12a,
12c, horizontal surfaces 11b, lid, 12b, 12d are combined so that they are in contact with each other; In this pressure sensor, the pressure sensing element 1 is mounted on one side of the joint 2, and a plurality of vertical surfaces 11a, llc, and horizontal surfaces 11b provided on the sides of the joint 2. ,l
A plurality of vertical surfaces 12a, 12c of the pressure-sensitive element l formed on the step portion 11 with the pressure-sensitive element l formed in imitation of the step portion 11,
A step of placing the horizontal surfaces 12b and 12d so that they are in contact with each other, and a step of welding the vertical surfaces 11a and 12a by bringing them into contact with each other so that the upper surfaces of the two upper vertical surfaces 11a and 12a form the same plane. This is a method for assembling a pressure sensor joint and a pressure sensing element.

Thus, the welded portion 8 is connected to the joint 2 and the pressure sensitive element l.
The first and second parallel surfaces 11b, 12b, lid are parallel to the unwelded portion formed by the second vertical surfaces 11e, 12c.
, 12d.

(Function) According to the above structure and assembly method, the direction in which cracks propagate due to the gap in the unwelded part is perpendicular to the fracture surface of the welded part, and the welded part is arranged parallel to the two perpendicular parts. This prevents damage to the weld due to cracks in the gap.

(Example) The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a partially enlarged view of FIG. 1, and FIG.
, (B), the joint 2 is provided with a stepped portion 11 forming two stages. That is, the stepped portion 11 has the first vertical surface 11a and the first vertical surface 11a.
The pressure sensitive element 1 is composed of a horizontal surface ttb, a second vertical surface 11c, and a second horizontal surface lid, and a stepped portion 12 is formed in the pressure sensitive element 1 so as to correspond to the stepped portion 11. That is, the stepped portion 12 is
First vertical surface 12a, first horizontal surface 12b, second vertical surface 12
c. A second horizontal surface 12d is provided. However, the first vertical plane 1
The wall thickness of 2a is set to such a cross-sectional area that the pressure sensitive element 1 and the joint 2 will not easily separate from each other due to the applied pressure.

After the step portions 11 and 12 are disposed so as to be in contact with each other, the first vertical surface 11a of the step portion 11 and the first vertical surface 12a of the step portion 12 are butt welded 8 to form the step portion. 11
．． A gap 13 of an unwelded portion is formed between the gaps 12 and 12. Welding part 8
is orthogonal to the horizontal planes 12b and 12b and exceeds them to reach a predetermined depth.

In the above configuration, the unwelded gap (fractured surface) formed between the second vertical part 12c of the stepped part 11 of the joint 2 and the second vertical part 12c of the stepped part 1 of the pressure-sensitive element 1 is connected to the welded part 8. Since it is parallel to the opposite direction and perpendicular to the crack generation direction lO, propagation of cracks due to pressure is prevented. Therefore, the connection between the joint 2 and the pressure-sensitive element 1 is strong, and there is no reduction in strength due to the occurrence of cracks. Reference numeral 17 is a collar forming a cap of the pressure-sensitive element.

An embodiment of the present invention is also illustrated in FIGS. 3(A) and 3(B).

In this example, a two-step portion is provided as in the first example, but the crack direction is opposite. That is, the stepped portion 14 of the joint 2 has a first vertical surface 14a, a first horizontal surface 14b, a second vertical surface 14c, and a second horizontal surface 14d, and the stepped portion 15 of the pressure sensitive element 1 has a first vertical surface 15a and a second horizontal surface. 15b, a second vertical surface 15C9, and a second horizontal surface 15d.

Therefore, the step portions 14 and 15 are combined, and each first
When butt welding 8 is performed on the vertical surfaces 14a and 15a, an unwelded gap 16 is formed.

The crack direction 10 of the gap 16 is therefore opposite to that of the first embodiment, as indicated by the arrow.

In this embodiment as well, based on the same principle as in the first embodiment, the unwelded gap 9 formed by the second vertical surfaces 14c and 15c is used.
is parallel to the welded portion 8 and perpendicular to the crack generation direction 10, so that propagation of cracks due to pressure is prevented. Therefore, the joint between the joint 2 and the pressure sensitive element is strong, and there is no possibility of a decrease in strength due to the occurrence of cracks.

(Effects of the Invention) As explained in detail above, according to the present invention, a pressure-sensitive element is provided with a step having a thickness necessary for strength, and a joint having a step that follows this step is fitted closely together. , a weld is formed that goes over the step and reaches a certain depth required for strength, and the weld is performed at the same time as the direction in which the gap caused by the unwelded part generates and propagates as a crack is perpendicular to the weld fracture surface. Since it is manufactured and constructed so that the gap formed between the vertical surfaces other than the vertical joint surfaces is parallel to the welded part, it prevents the propagation of the crack and also prevents the joint between the joint and the pressure-sensitive element. It has the effect of making it stronger.

[Brief explanation of drawings]

1 and 2 show an embodiment of the pressure sensor according to the present invention, FIG. 1 is a side view partially shown in cross section, and FIG.
) and (B) are partially enlarged sectional views of FIG. FIGS. 3(A) and 3(B) are enlarged sectional views of another embodiment. FIG. 4 (A) is a partially sectional side view of a conventional pressure sensor. No. 41 Δ(B) is a partially enlarged sectional view of the same (A). FIG. 5 is an enlarged sectional view of FIG. 4 CB) with a welded part. FIG. 6 is an enlarged sectional view corresponding to FIG. 5 of another conventional example provided with a welded portion. l...Pressure sensitive element, 2...Joint, 8...Welding, 10...Arrow (crack direction), 11...Step, ll
a...first vertical plane, llb...first horizontal plane, 11c
...Second vertical plane, lid...Second horizontal plane, 12...
- Step portion 12a...first vertical surface, 12b...first horizontal surface, 12c...second vertical surface, 12d...second horizontal surface, 13...gap, 14...step portion, 14a...first
Vertical surface 14b...first horizontal surface, 14c...second vertical surface, 14d...second horizontal surface, 15...step, 15a
...first vertical surface, 15b...first horizontal surface, 15c.
...Second vertical surface, 15d...Second horizontal surface 6...Gap.

Claims (1)

[Claims] 1. A pressure sensor in which a pressure-sensitive element is mounted on one side of a joint, in which a joint is provided with a stepped portion having a plurality of vertical surfaces and horizontal surfaces on one side, and a surface facing the joint. a pressure-sensitive element provided with a stepped portion having a plurality of vertical surfaces and horizontal surfaces formed in imitation of the stepped portions of the joint; and the joint and the pressure-sensitive element are brought into contact with each other by the respective vertical surfaces and horizontal surfaces of the stepped portions. and a welded portion formed between a pair of upper vertical surfaces that are combined and abutted against each other. 2. In a pressure sensor in which a pressure-sensitive element is attached to one side of a joint, a stepped portion provided on one side of the joint with a plurality of vertical and horizontal surfaces is formed in imitation of the stepped portion. A step of placing a plurality of vertical surfaces and horizontal surfaces of a pressure sensitive element so that they are in contact with each other, and a step of welding the vertical surfaces by bringing the upper surfaces of the two upper vertical surfaces into contact with each other so as to form the same plane. A method of assembling a pressure sensor. 3. The welded portion is configured to be parallel to the unwelded portion formed by the second vertical plane of the joint and the pressure sensitive element, and perpendicular to the unwelded portion formed by the first and second parallel surfaces. or a structure of the pressure sensor according to claim 1 or 2 and a method of assembling the same. 4. The configuration of the pressure sensor according to claim 1, wherein stepped portions are formed on the joint and the pressure-sensitive element so that cracks occur in opposite directions in the gap between the unwelded portions. 5. The configuration and assembly method of a pressure sensor according to claim 1 or 2, wherein the pressure sensor has a welded portion formed at a predetermined depth perpendicularly to and beyond the first horizontal plane of the joint and the pressure-sensitive element.