JPH04134233A - Caulking method for tubular thin-plate metal piece and manufacture of gasket-type pressure sensor - Google Patents

Abstract

PURPOSE:To prevent generation of buckling on the inner peripheral wall of a caulked body after its caulking by caulking a protruding tubular portion protruded from a ring-form end face so that with the position of nearly halving the protruding tubular portion as the bounding the angle between the ring-form end face and the tubular portion is about 60 deg. at the tip and about 45 deg. at the base. CONSTITUTION:An assembly 1 is inserted into a tubular portion 220 of a metal piece 200 of L sectional form consisting of a tubular portion 220 and a flange portion 210 extending outward from one end thereof. A tubular portion 221 protruding from a rear-end face 18 of the assembly is caulked so that with the position (n) of nearly halving the protruding tubular portion as the boundary the angle between the ring-form end face 18 and the tubular portion 220 is 60 deg.+ or -15 deg. at the tip 222 and 45 deg.+ or -15 deg. at the base 223 (however, the angle at the tip theta1 > the angle at the base theta2). The base 223 is flat caulked so that the base 223 may abut on the rear-end face 18 of the assembly. Therefore, there occurs no buckling on the inner-peripheray wall 22 of a metal housing 2, so that cracking of a piezo-electric element 11 or of an insulating plate 14 and deformation of an electrode plate 12 and plate packings 13, 15 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique suitable for manufacturing a gasket-type pressure sensor that is attached to the seating surface of a spark plug to measure pressure changes in a combustion chamber.

[Prior Art] Conventionally, when manufacturing a gasket-type pressure sensor, caulking of a thin plate metal fitting is performed by caulking a metal fitting 300 having a cross-sectional shape consisting of a flange portion and a cylindrical portion 310, as shown in FIG. 2(I). Cylinder part 3
10, a piezoelectric element 410, an insulating plate 420, an insulating tube 430, a presser foot 440, an electrode plate 450, and a plate packing 46
Insert the ring shape 400 with the 0 etc. attached, Fig. 2 (II)
As shown in FIG. 3, this is done by caulking a portion 311 protruding from the upper end surface 401 of the ring 400.

[Problems to be Solved by the Invention] However, in the above conventional technology, the length of the caulked portion is 4
If 03 is relatively short (4.0mm to 4.5mm),
Although no seating surface is generated on the inner peripheral wall 321 of the caulking body 320,
If the length 403 of the caulked portion is long (8, Om or more), as shown in FIG. There is.

An object of the present invention is to provide a method for crimping a cylindrical thin sheet metal fitting and a method for manufacturing a gasket-type pressure sensor in which a seat surface does not appear on the inner circumferential wall of the crimped body after crimping, even when the ring shape or the sensor body is relatively thick. It is in.

[Means for Solving the Problems] In order to solve the above problems, the present invention employs the following configuration.

(1) A step of fitting a ring shape containing a brittle body into the cylindrical part of a cylindrical thin sheet metal fitting having a truncated cross-section, which consists of a cylindrical part and a flange extending outward from one end of the cylindrical part, and a protrusion protruding from the ring-shaped end surface. This protruding cylindrical portion is bent so that the angle formed between the annular end face and the cylindrical portion is approximately 60° at the tip and approximately 45° at the base, with the cylindrical portion approximately bisected.

a step of caulking so that the base portion comes into contact with the ring-shaped end surface; a step of caulking so that the tip portion comes into contact with the ring-shaped end surface; caulking a portion extending from the outer peripheral surface of the ring shape in the direction of the outer peripheral surface. Consists of processes.

(2) A cylindrical thin sheet metal fitting with a cross section consisting of a cylindrical portion and a flange extending outward from one end of the cylindrical portion has a piezoelectric element made of Ceramic Lif, an electrode plate, an insulating plate, and a plate plate ( In the process of fitting the ring-shaped sensor body made of laminated pieces, etc., the angle formed by the end face of the sensor body and the cylindrical part is the tip of the protruding cylindrical part that protrudes from the end face of the sensor body. Approximately 60 in total
゜, a step of caulking this protruding cylinder so that the angle at the base is about 45 degrees, a step of caulking so that the base comes into contact with the end surface of the sensor body, a step of caulking so that the tip comes into contact with the end surface of the sensor body. a tightening step, and a step of tightening a portion extending from the outer circumferential surface of the sensor body in the direction of the outer circumferential surface.

[Actions and Effects of the Invention] (Regarding Claim 1) With the approximately bisecting portion of the protruding cylindrical portion protruding from the ring-shaped end surface as the border,
The protruding cylindrical portion is caulked so that the angle formed between the ring-shaped end face and the cylindrical portion is approximately 60° at the tip and approximately 45° at the base, and then,
The base is caulked so as to come into contact with the annular end surface, and the tip is caulked so as to come into contact with the annular end surface.

For this reason, the stress caused by the caulking work is not easily applied to the base of the base, so that even if the length of the caulked portion is relatively long, no seating surface is generated on the inner circumferential wall of the caulked body.

Therefore, damage to the brittle body due to the seat surface does not occur.

Incidentally, if the angle formed between the annular end face and the cylindrical portion deviates significantly from the range of 60° at the tip and 45° at the base (by more than ±15° each), a seat surface is likely to occur.

(Regarding Claim 2) The angle formed by the end surface of the sensor body and the cylinder part is about 60 degrees at the tip and about 45 degrees at the base, with the protruding cylinder part protruding from the end surface of the sensor body dividing into approximately equal parts. The protruding cylindrical portion is caulked so that the protruding tube has an angle of 1.degree., the base portion is caulked so as to come into contact with the end surface of the sensor body, and the tip portion is further caulked so as to come into contact with the end surface of the sensor body.

Therefore, the stress caused by the caulking work is not easily applied to the base of the base, so that even if the length of the caulking part is relatively long, no seating surface is generated on the inner circumferential wall of the caulking body.

Therefore, damage to the ceramic piezoelectric element and the insulating plate due to the seat surface does not occur.

Note that the angle formed by the end surface of the sensor body and the cylindrical portion is 6 mm at the tip.
If it deviates significantly from the range of 0° and 45° at the base (more than ±15° each), a seat surface is likely to occur.

[Example] An embodiment of the present invention will be described based on FIG.

As shown in Figure 1 (V), gasket type pressure sensor A
The assembled body 1 is a metal housing 2 formed of a thin metal plate.
It will be surrounded by

The assembly 1 has a ring shape as a whole and is composed of a piezoelectric element 11, an electrode plate 12, a plate packing 13, 15, an insulating plate 14, an insulating tube 16, and a presser foot 17.

The piezoelectric element 11, which is a brittle body, has an annular shape and is formed by sintering piezoelectric ceramic such as lead zirconate titanate, and generates an electromotive force in response to applied pressure. The electrode plate ] 2 is stacked on the top surface of the piezoelectric element 11 in the drawing, and the plate !2 is stacked on the bottom surface in the drawing. <Cooking 13 is stacked.

The electrode plate 12 has an annular shape and is made of stainless steel, silicon, or copper-based metal plate, and is electrically conductive with the piezoelectric element 11 and sends the electromotive force generated by the piezoelectric element 11 to a detection device (not shown). It is connected by welding to a connecting cord (not shown).

Further, an insulating plate 14 is stacked on the upper surface of the electrode plate 12 in the drawing.

The insulating plate 14, which is a brittle body, has an annular shape and is an insulating material made of ceramic. Also, the illustration of this insulating plate 14"-
A plate packing 15 is stacked on the surface.

Plate packing] 3.15 is an annular metal plate made of stainless steel or copper, and softens the external force applied to the piezoelectric element 11 and the insulating plate 14.

The insulating tube 16 is made of Teflon resin that electrically insulates the electrode plate 12 from the housing 2.

The presser foot 17 is a metal tube whose outer surface is coated with resin to maintain airtightness.

The metal housing 2 is made of austenitic 5US304.
(thickness 0.3 mm), hollow ring shape with opening 21 (inner diameter 14 mm, outer diameter 22 mm, height 8.6 m
m).

Next, the manufacturing method (crimping process) of the gasket type pressure sensor A will be explained.

(1) As shown in FIG.
20 and a flange 210 extending outward from one end of the metal fitting 200, which has an angular cross section.

(2) As shown in FIG. 1 (U), the rear end surface 18 of the assembled body and the cylinder The angle formed with the part 220 is 60°±15 at the tip 222 and 45°±1 at the base 223.
This protruding cylindrical portion 221 is caulked so that the angle is 5° (where the angle θ1 at the tip is greater than the angle θ2 at the base).

(3) As shown in FIG. 1 (I[[), the base portion 223 is flat caulked so that the base portion 223 comes into contact with the rear end surface 18 of the assembled body.

(4) As shown in FIG. 1 (IV), the tip portion 222 is flat caulked so that the tip portion 222 comes into contact with the rear end surface 18 of the assembled body.

(5) Furthermore, the parts p and q extending from the outer circumferential surface 19 of the assembled body 1 are laterally caulked, resulting in the gasket type pressure sensor A shown in FIG. 1(V).

The effects of this embodiment will be described below. (A) No seating surface occurs on the inner circumferential wall 22 of the metal housing 2, cracks in the piezoelectric element 11 and the insulating plate 1°1, and deformation of the electrode plate 12 and the plate packing 13 and 15. can be prevented.

(2) Since the inner circumferential wall 22 of the metal housing 2 does not deform, the gas get type pressure sensor A can be placed on the seat surface of the spark plug with high precision.

(c) Since the caulking process is simple, manufacturing costs do not increase significantly.

Kue> The thickness of the metal fitting 200 used for the metal housing 2 is 0
．． A value of 2 mm to 0.6 mm is particularly good.

[Brief explanation of the drawing]

FIG. 1 is a manufacturing process diagram of a gasket type pressure sensor according to an embodiment of the present invention. FIG. 2 is a process diagram for manufacturing a gasket type pressure sensor using a conventional method. In the diagram 1... Assembly body ring-shaped, sensor body) 11...
Piezoelectric element 12... Electrode plate 13.15... Plate plate
Socking 14... Insulating plate 18... Rear end surface of the assembly (
Ring-shaped end surface, end surface of sensor body) 200... Thin sheet metal fitting (cylindrical thin sheet metal fitting) 210... Flange portion 220... Cylindrical portion 221... Projecting cylinder portion 222... Tip portion 223.
...Base n...Approximately bisecting part θ1...Angle (angle formed by the ring-shaped end face and the cylinder part, angle formed by the end face of the sensor body and the cylinder part) θ-...Angle (the angle formed by the ring-shaped end face and the cylinder part) The angle formed by the
Angle formed between the end face of the sensor body and the cylinder part) A... Gaskera 1~ type pressure sensor

Claims (1)

[Claims] 1) A method for caulking a cylindrical thin sheet metal fitting comprising the following steps. A step of fitting a ring shape containing a brittle body into the cylindrical portion of a cylindrical thin sheet metal fitting having an L-shaped cross section and consisting of a cylindrical portion and a flange portion extending outward from one end of the cylindrical portion. Bordering the approximately bisecting portion of the protruding cylinder protruding from the ring-shaped end surface,
The process of caulking this protruding cylindrical portion so that the angle formed between the ring-shaped end face and the cylindrical portion is approximately 60° at the tip and approximately 45° at the base. crimping the base so that it comes into contact with the ring-shaped end surface. A step of caulking so that the tip comes into contact with the ring-shaped end surface. A step of caulking the portion extending from the outer peripheral surface of the ring shape in the direction of the outer peripheral surface. 2) A method for manufacturing a gasket type pressure sensor comprising the following steps. A cylindrical thin sheet metal fitting having an L-shaped cross section and consisting of a cylindrical portion and a flange extending outward from one end thereof, and a ceramic piezoelectric element, an electrode plate, an insulating plate, a plate packing, etc. are laminated on the cylindrical portion. The process of fitting the ring-shaped sensor body. This is done so that the angle formed by the end surface of the sensor body and the cylindrical portion is approximately 60° at the tip and approximately 45° at the base, with the approximately bisecting portion of the protruding cylindrical portion protruding from the end surface of the sensor body. Process of caulking the protruding cylinder. crimping the base so that it comes into contact with the end surface of the sensor body. crimping the tip so that it comes into contact with the end surface of the sensor body. a step of caulking a portion extending from the outer peripheral surface of the sensor body in the direction of the outer peripheral surface;