JPH0749128B2 - Method for manufacturing deformed container for metal thermos - Google Patents

Description

TECHNICAL FIELD The present invention relates to a deformed container for metal thermos, and more particularly to a method for manufacturing a deformed container for metal thermos.

(Prior Art) Recently, instead of a water bottle or a portable glass thermos, a metal thermos with excellent durability is widely used. These metal thermos bottles usually employ stainless steel as the material from the viewpoints of corrosion resistance and strength, and form the inner and outer container components by expanding, contracting and other plastic working methods.
These are welded together to form a double-walled structure. The space forming surface between both containers is plated with silver or copper, and the space between both containers is vacuum-insulated. The form is usually cylindrical. Has been adopted.

(Problems to be solved by the invention) However, compared to an oval-type water bottle, a thermos having a cylindrical shape has a small contact area with the human body when it is hung from the shoulder and carried, so it easily sways,
Moreover, since the diameter increases as the content volume increases,
There is a problem that handling becomes difficult, such as when holding by hand or removing the lid. The latter problem is not limited to hanging strings,
The problem can be solved by providing a handle on the body of the thermos, but there is a problem that portability is further deteriorated because the handle protrudes from the thermos.

On the other hand, the problem of handling and portability can be solved by making the shape of the thermos oval type or by making the cross section of both the inner and outer containers elliptical, oval, cocoon-shaped, etc. Flanged joints made by bending the ends of the material together have good productivity, but have a fatal drawback for thermos bottles that easily cause crevice corrosion.Therefore, the butt joints do not deteriorate corrosion resistance. Must be adopted. However, butt welding is difficult even if it is circumferential welding together with the thin wall thickness of the container material, and welding is extremely difficult when the radius of curvature changes continuously such as elliptical shape, oval shape and cocoon shape. There was a problem that it was difficult.

(Means for Solving Problems) As a means for solving the above problems, the present invention forms a cylindrical container by forming a container body member and a bottom member each having a circular end surface, and butt-welding both members. After forming, the cylindrical container is placed in a split mold that forms a cavity of a predetermined shape when the mold is clamped, and a liquid is put into the cylindrical container to mold the mold while clamping the split mold. By increasing the pressurizing pressure to the liquid according to the degree of tightening, the cylindrical container is flattened and the cylindrical container is expanded in a direction orthogonal to the flattening direction and the bottom member is deformed into a taper shape. The present invention provides a method for manufacturing a deformed container for a metal thermos, which is characterized in that

(Operation) That is, in order to improve portability, the present invention provides a deformed container having a cross-sectional shape of an elliptical shape, an oval shape, a cocoon shape, etc. Since it is extremely difficult because the radius of curvature of the portion changes continuously, welding of both members is performed in advance by forming the welding line into a circular shape, that is, by forming the container body member and the bottom member having circular end faces. It is possible to flatten a cylindrical container formed by butt welding with a split mold, and at the same time, expand it in the flattening direction and the orthogonal direction by the pressure of the liquid put in the cylindrical container. It is possible to manufacture.

Hereinafter, examples in which the method of the present invention is applied to manufacture of an inner container will be specifically described with reference to the accompanying drawings.

First, the inner container body member 1a is formed by subjecting a 0.5 mm-thick stainless steel plate to a tubular steel pipe obtained by rounding welding or forging or a commercially available stainless steel pipe by subjecting it to expansion and contraction processing (FIG. 1A), Deep drawing is performed on a stainless steel plate to form a bottom member 1b which is a bottomed container having a circular end surface (first
(B), these are butt-welded to form a cylindrical container 1 (c).

Next, as shown in FIG. 2, the cylindrical container 1 is divided into molds 11
Place it inside. This split mold is composed of an upper mold 12 and a lower mold 13, and the upper mold 12 is divided into two parts, which retains the cylindrical shape of the cylindrical container 1 without deforming the neck portion of the cylindrical container 1 during processing. A liquid, for example, water is put into the container through the mouth of the container 1, and the inside of the container is communicated with a pressurizing device, for example, a hydraulic pump or a hydraulic cylinder. The lower die 13 is divided into four members, and a pair of opposing divided dies are arranged so that they can advance and retreat with each other to form an oval-type cavity when the die is clamped.

In this state, when the pressure applied from the hydraulic cylinder to the liquid inside the container is increased according to the degree of mold clamping while clamping the mold, the cylindrical container 1 advances and retreats in the direction perpendicular to the paper surface of FIG. The pair of split molds are flattened by approaching each other, and are expanded in the flat direction and the orthogonal direction by the hydraulic pressure applied to the liquid, and the split molds 14a, 14b are advanced and retracted horizontally in the plane of FIG. Molded along the cavity surface 15.

When the mold is completely clamped, the plastic working of the oval type odd-shaped inner container 1'as shown in FIGS. 1 and 3 is completed. As shown in FIG. 1D, the side portion 1c of the bottom member 1b of the deformed inner container 1'is deformed into a taper shape because when an outer shell having an arcuate cross section is formed, plastic working by mold clamping is performed. This is because the inner container 1 is sometimes damaged from the welded portion 3 at that time. In order to improve workability and prevent damage during processing, the outer circumference of the body of the cylindrical container 1 should be set to be equal to or slightly smaller than the outer circumference of the body of the deformed container 1 '. It is effective to keep it.

After forming a metal coating such as silver plating or copper plating on the outer surface of the irregular-shaped inner container 1'obtained as described above as a radiation preventing film or winding a metal foil such as copper foil, silver foil or aluminum foil Separately, a main body 5 of the outer container 4 and a deformed inner container 1 ', which are separately prepared, are welded at the tips 6 of their mouths. Next, the bottom member 9 to which the getter 7 and the tip tube 8 are previously attached is welded to the end portion of the outer container body 5 to form a container having a double wall structure. Since the outer container 4 does not always come into contact with the liquid, it can be manufactured by a known method, and in order to improve productivity, the neck member 5a, the body member 5b, and the body forming the outer container body 4 are formed. Member 5b and bottom member 9
Is a flange joint 10 in which the ends of the respective members are bent to form a fitting.

This double-walled container is evacuated at a temperature not higher than the transformation point of stainless steel, and the space formed between the inner container and the outer container is evacuated, and then the tip tube is sprayed and a getter is used. By activating, the vacuum insulated double-walled container having the structure shown in FIGS. 3 and 4 can be manufactured.

By the way, the vacuum insulating double-walled container having the above-described structure showed heat retention performance equivalent to or higher than that of a thermos using a commercially available cylindrical vacuum insulating double-walled container even when a copper foil was used as a radiation preventing film. By processing the cylindrical container 1 into the deformed container 1 ', the internal volume was increased by about 10%.

(Effects of the Invention) As is apparent from the above description, according to the present invention, since a cylindrical container is manufactured in advance and is plastically processed, any arbitrary shape such as an elliptical cross section, an oval shape, or a cocoon shape can be obtained. Since it is possible to manufacture a deformed container having an outer shape and the ratio of the major axis to the minor axis can be set relatively arbitrarily, it is possible to manufacture an oval type thermos bottle having a wide contact area with a human body and having good portability. Further, since the internal volume can be increased without increasing the minor axis, it is possible to obtain an excellent effect such as easy handling even when holding the thermos by hand or removing the lid.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing process of a deformed container for a thermos bottle according to the method of the present invention, FIG. 2 is an explanatory view showing a state of plastic working from the form of FIG. 1C to the form of FIG. FIG. 4 is a partially cutaway side view of a vacuum-insulated double-walled container using a deformed container manufactured by the method of the present invention, and FIG. 4 is a partially sectional front view thereof. 1 ... Cylindrical inner container, 1a ... Inner container body member, 1b ... Bottom member, 3 ... Welded part, 4 ... Outer container, 5 ... Outer container body,
11 …… Split mold, 12 …… Upper mold, 13 …… Lower mold.

Claims (1)

[Claims] 1. A split mold for forming a container body member and a bottom member each having a circular end surface, forming a cylindrical container by butt-welding both members, and then forming a cavity of a predetermined shape during mold clamping. While placing the cylindrical container in,
At the same time as flattening the cylindrical container, a liquid is put into the cylindrical container and the pressure applied to the liquid is increased according to the degree of mold clamping while clamping the split mold. A method of manufacturing a deformed container for a metal thermos, characterized in that the cylindrical container is expanded in the flat direction and the orthogonal direction, and the bottom member is deformed into a taper shape.