JPH07195135A - Production of thermos bottle - Google Patents

Abstract

PURPOSE:To obtain a thermos bottle of metal by welding ends of a cylinder like inner body and a cylinder like outer body, leaving a recessed position at the welding and arranging a getter to realize an excellent vacuum state in a clearance between the cylinder like inner body and the cylinder like outer body. CONSTITUTION:A bottom member 3 is fitted to the inside of a cylinder like inner body 2, and welded its end part to an end part of a joining piece and the cylinder like inner body 2. Successively, a prescribed position of the cylinder like inner body 2 is pressed inward and one of recessed part is provided. Then, the cylinder like body 2 integrated with this bottom member 3 is co-axially arranged inside the cylinder like outer body 1, while interposing a prescribed clearance. Successively, the end parts of the cylinder like inner body 2 and the cylinder like outer body 1 are welded. In this welding, a recessed part 4 is left, a brazing filler metal 7 is built in a space surrounded with this recessed part and the cylinder like outer body 1, a wire 6 of a prescribed length is placed on it. Successively, it is heated in a vacuum furnace, sealed in vacuum and the excellent electric kettle is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal thermos bottle such as an electric water heater.

[0002]

2. Description of the Related Art As a conventional method for manufacturing a metal thermos bottle, for example, Japanese Patent Publication No. 61-11.
No. 35 (hereinafter referred to as the conventional method) has been proposed.

This conventional method, as shown in FIG.
An inner cylinder 31 is disposed inside 32, a brazing material 33 is disposed in the gap between the inner cylinder 31 and the outer cylinder 32 on the mouth side, and the mouth is placed downward (state of FIG. 8) in a vacuum heating furnace. In the above, the mouth portion is vacuum-sealed.

Therefore, in the conventional method, unless the wax material 33 surely seals the entire circumference of the gap between the inner cylinder 31 and the outer cylinder 32 on the mouth side (the wax material 33 does not spread well over the entire circumference). And), inner cylinder 31 and outer cylinder 3
The gap with 2 is in a poor vacuum state (if there is a sealing failure, the degree of vacuum may decrease due to continued use).

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing a metal thermos bottle which can obtain a metal thermos bottle having a good vacuum state. .

[0006]

The gist of the present invention will be described with reference to the accompanying drawings.

A metal-made large-diameter tubular outer body 1, a metal-made small-diameter tubular inner body 2 and a metal-made bottom member 3 fitted inside the tubular inner body 2. A method for manufacturing a metal thermos, in which a gap between a cylindrical outer body 1 and a cylindrical inner body 2 is vacuum-insulated, wherein a joining piece 3 ′ is erected on an outer periphery of a bottom member 3,
The bottom member 3 is fitted inside the tubular inner body 2 and the joining piece 3 ′ of the bottom member 3 and the end portion of the tubular inner body 2 are welded together.
A predetermined position of the cylindrical inner body 2 is pressed inwardly to provide a recess 4, and then the cylindrical inner body 2 integrated with the bottom member 3 is coaxially arranged in the cylindrical outer body 1 to form a gap. And arranging them to accommodate them, and subsequently welding the ends of the cylindrical inner body 2 and the cylindrical outer body 1 except for the position of the recess 4, and subsequently, an appropriate wire rod in the recess 4. 6 and a suitable brazing material 7 are placed, and subsequently, the cylindrical outer body 1 and the cylindrical inner body 2 are vacuum-sealed by vacuum heating in accordance with a conventional method. It is related.

[0008]

[Function] Since the portion to be vacuum-sealed by the wax material 7 is small (small), a metal vacuum bottle in a good vacuum state can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings are embodiments of the present invention, which will be described below.

A cylindrical outer body 1 made of stainless steel and having a large diameter, a cylindrical inner body 2 made of stainless steel and having a small diameter, and a disk-shaped bottom member 3 having a diameter substantially equal to the inner diameter of the cylindrical inner body 2 made of stainless steel.
To provide. On the outer periphery of the bottom member 3, a joint piece 3'formed by bending is erected.

The bottom member 3 is fitted in the cylindrical inner body 2 and the end of the joining piece 3'and the end of the cylindrical inner body 2 are welded together (see FIG. 1).

Subsequently, a predetermined position of the cylindrical inner body 2 is pressed inwardly (by press working) to form one recess 4 therein.
(See Figures 2 and 3).

Subsequently, the cylindrical inner body 2 integrated with the bottom member 3 is coaxially housed in the cylindrical outer body 1 with a predetermined gap interposed therebetween.

Subsequently, the ends of the cylindrical inner body 2 and the cylindrical outer body 1 are welded. In this welding, the recess 4 position is left. The cylindrical inner body 2 and the cylindrical outer body 1 are, of course, welded to each other on the mouth side end portions, and a good vacuum state is realized in the gap between the cylindrical inner body 2 and the cylindrical outer body 1. Therefore, a getter is installed.

Subsequently, a brazing material 7 is placed in a space surrounded by the recess 4 and the tubular outer body 1, and a wire of a predetermined length is placed on the brazing material 7 (see FIGS. 4 and 5). The brazing material 7 may be laid on the wire, or the brazing material 7 alone can be used for manufacturing.

Then, in this state, it is housed in a vacuum heating furnace,
When heated at a vacuum degree of 10 ^-2 Torr or less and a temperature of 600 ° C to 1200 ° C, the wax material 7 is melted and vacuum suction is performed from a portion in Fig. 6, so that the cylindrical outer body 1 and the cylindrical inner body 2 are separated from each other. Is vacuum-sealed, and the electric water heater 5 shown in FIG. 7 having good heat insulation is manufactured.

In the figure, reference numeral 8 is a heater section, and 9 is a switch section.

Since this embodiment uses the above-described manufacturing method, there are few portions to be vacuum-sealed by the wire and the brazing material 7, that is, there are few portions where the brazing material 7 must be melted and spread, and the sealing is ensured. Since there are many welded portions that can be formed, it is possible to reduce the vacuum sealing failure between the tubular outer body 1 and the tubular inner body 2, and a good vacuum state can be realized as much as that. Further, according to the present embodiment. Since the product is formed by welding the tubular outer body 1 and the tubular inner body 2 by welding, the product is a product according to the conventional method in which the tubular outer body 1 and the tubular inner body 2 are joined only by the wax material 7. On the other hand, it is firm and the vacuum sealing is performed by appropriately combining the wire and the wax material 7.
Therefore, the strength of the vacuum-sealed portion is improved (the wire acts as a reinforcing material) as much as the wire is present as compared with the case where only the wax material 7 is used.

[0019]

As described above, according to the present invention, since the portion to be vacuum-sealed by the wax material is reduced as described above, a good vacuum state can be surely obtained. You will be able to provide a thermos.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a manufacturing process of this embodiment.

FIG. 2 is a cross-sectional view of a manufacturing process of this embodiment.

FIG. 3 is a cross-sectional view of the manufacturing process of the present embodiment (cross-section taken along the line BB in FIG. 5).

FIG. 4 is a cross-sectional view of the manufacturing process of the present embodiment (cross section taken along the line AA in FIG. 5).

FIG. 5 is a plan view of the manufacturing process of this embodiment.

FIG. 6 is a cross-sectional view of the manufacturing process of the present embodiment (cross section taken along the line AA in FIG. 5).

FIG. 7 is a front view in which a metal thermos bottle manufactured according to the present embodiment is partially cut away.

FIG. 8 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Tubular outer body 2 Tubular inner body 3 Bottom member 3'Joint piece 4 Recess 6 Wire rod 7 Wax material

Claims (1)

[Claims] 1. A cylinder comprising a metal-made large-diameter tubular outer body, a metal-made small-diameter tubular inner body, and a metal-made bottom member fitted inside the tubular inner body. A method for manufacturing a metal thermos, wherein a gap between a cylindrical outer body and a cylindrical inner body is vacuum-insulated, in which a joining piece is erected on the outer periphery of a bottom member, and the bottom member is placed inside the cylindrical inner body. By fitting and welding the joining piece of the bottom member and the end portion of the cylindrical inner body, subsequently, a predetermined position of the cylindrical inner body is pressed inward to form a recess, and then the bottom portion The cylindrical inner body integrated with the material is accommodated and arranged coaxially in the cylindrical outer body with a gap therebetween, and subsequently, the end portions of the cylindrical inner body and the cylindrical outer body are placed in the recessed position. Except for welding, subsequently place an appropriate wire material and an appropriate wax material in the recess, and subsequently vacuum heat the cylindrical outer body and the cylindrical inner body by vacuum heating according to a conventional method. Gold characterized by A method of manufacturing a genus-made thermos.