JPS5930484A - Production of thin-walled hollow spherical shell of stainless steel - Google Patents

Abstract

PURPOSE:To produce a hollow spherical shell having exact out of roundness with good efficiency, by forming two pieces of semispherical shells, forming the outside circumferential surface of a reinforcing ring that conceals the inside circumferential surfaces in both openings of the respective semispherical shells to a true spherical surface and subjecting the semispherical shells to butt welding. CONSTITUTION:A stainless steel plate which is blanked to a circular shape by blanking or the like is drawn to form two semispherical shells 1a, 1b. The circumferential edges in the openings of the shells 1a, 1b are machined to have the edges of a prescribed diameter. On the other hand, a reinforcing joint ring 3 having the width concealing the inside circumferential surfaces near the circumferential edges in both openings of the shells 1a, 1b is formed and the outside circumferential surface thereof is machined to form a true spherical surface 4. A projecting annular line 3a is formed in the central part of the ring 3 and the circumferential edges in the openings of the respective semispherical shells are butted to the top and bottom surfaces of the line 3a, and are welded by TIG welding or the like. The projecting parts in the weld joint parts 5a, 5b are machined and the entire surface of the outside circumference is polished, whereby the thin-walled hollow spherical shell of stainless steel is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a thin stainless steel hollow spherical shell that can efficiently and easily produce a thin stainless steel hollow spherical shell having accurate roundness. Exhaust valves, float valves, etc. (= are used, but their roundness is strictly required 0) Conventionally, the major disadvantage of roundness in manufacturing this thin-walled hollow spherical shell is: In the case of manufacturing thick-walled hollow spherical shells, the adverse effects caused by material distortion are noticeable only in the manufacture of thin-walled hollow spherical shells.

In other words, when the opening Ffii edge of a hemispherical shell formed by press drawing etc. is edge-trimmed, the flow line is cut due to the exposure of internal creases caused by press drawing etc. and the rolling direction. The periphery of the opening of the hemispherical shell warps due to springback, etc., and as it is butt welded, there is a major problem in that a hollow spherical shell with accurate roundness cannot be manufactured.

The present invention aims to solve these problems and provide a method for manufacturing a thin stainless steel hollow spherical shell with high roundness.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

Two hemispherical shells (la) (lb) are formed by drawing a punched stainless steel plate (2 hemispherical shells (lB) (lb) (D) 2
8) (2b) is formed with a predetermined diameter edge (two) by turning etc.
On the other hand, both opening peripheries (21
'1) (2b) A reinforcing joint ring (3) having a width that hides the inner peripheral surface in the vicinity is formed by turning the vibrator material.

The outer peripheral surface of the reinforcing joint ring (3) is formed into a perfect spherical surface (4) by turning or the like.

In this embodiment, an abutment ring (3a) is formed in the center of the reinforcing joint ring (3), and each opening periphery (2a) (2b)'& abutment center is formed on the upper and lower m1 of this abutment ring (3a). This allows accurate (T7.@) determination of the hemispherical shells (la) and (lb), making subsequent seam welding easy and reliable.

Note that the reinforcing joint ring (3) of this example has a hemispherical shell (1a).
It is made of the same stainless steel material as (1b).

Butt each hemispherical shell (la) (lb) with the inner peripheral surface near both opening peripheries (2a) (2b) of each hemispherical shell (la) (lb) in close contact with the true spherical circular surface (4). In this state, welding is performed, for example, by Alcon welding, TIGffj welding, etc.

Next, the protruding parts of the welded joints (5a) and (5b) are removed with a forming tool or the like (2). Then, a thin stainless steel hollow spherical shell (5) is manufactured.

As mentioned above, each half Tf, shell (la) (lb)
Reinforcing joint ring (3) with a width that hides the inner circumferential surface near the same edges (2a) and (2b) of both openings (2) Turning the rubber/rpe material, etc. The outer circumferential surface of the hemispherical shell (la) (lb) is formed by turning, etc. ) (2b) Weld each hemispherical shell (18) (lb) in a butt state with the inner circumferential surfaces in close contact with each other ゛3
Therefore, the inner peripheral surface of each hemispherical shell (1g) (lb) is welded in close contact with the true spherical surface (4) of the reinforcing joint ring (3). is each hemispherical shell (
The purpose is to correct the opening periphery (2a) (2b), which is warped due to internal strain of la) (lb), rolling direction, etc., into a perfect circle. Will be welded in high degree condition, therefore high precision,
^ It is possible to manufacture thin-walled stainless steel hollow spherical shells with good roundness (Second).

In addition, since the reinforcing joint ring (3) is interposed at the butt part of each hemispherical shell (la) (lb), that is, the welded joint part (5a) (5b), the welded joint part (5g) (5
In addition to providing the connection reinforcement effect described in b), the welding strength is also significantly improved (Second).

Also, after welding the welded joints (5a) and (5b), we cut them.

Since the polishing process is performed, it is possible to manufacture a product with a higher -N74 circularity and a smoother surface.

In addition, since the manufacturing process is simplified and the work in each process is simple, the production efficiency is also increased, resulting in a product with an extremely high reputation.

As described above, according to the present invention, a method for manufacturing a thin stainless steel hollow spherical shell that exhibits revolutionary effects such as being able to efficiently and easily manufacture a thin stainless steel hollow spherical shell having accurate roundness is provided. will be provided.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an exploded perspective view, FIG. 2 is a longitudinal cross-sectional view, and FIG. 3 is a diagram of a completed product. (to) Thin-walled stainless steel hollow spherical shell, (la) (lb)
... Hemispherical shell, (2a) (2b) ... Opening rim, (3)
・Reinforced joint link, (4)...True spherical surface, (5a) (5
b)...Welded joint. August 11, 1981 Applicant: Niigata Stainless Co., Ltd. Inventor: Shigeaki Kosaka〕／Sakai＾〕／Junior 1

Claims (1)

[Claims] Two hemispherical shells are formed by drawing a stainless steel plate cut out into a circular shape from C2 by punching, etc., and a constant diameter edge is formed by turning the open circumference of each hemispherical shell, etc. On the other hand, the reinforcing joint ring of the sleeve of the sleeve which hides the inner circumference near the outer edge of the six-hemispherical shell is turned, etc. (2). The outer circumferential surface is formed into a perfect spherical surface by turning or the like, and each hemispherical shell is welded to the perfect spherical surface in an abutted layer with the inner circumferential surface near the periphery of both openings of each hemispherical shell being tightly packed. 1. A method for manufacturing a thin stainless steel hollow spherical shell, which comprises: 1) turning or polishing the protruding portion of the welded joint, and then polishing to produce a thin stainless steel hollow spherical shell;