JPH0325719Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to the mouth structure of a metal double container, and in particular, to a metal double container suitable for use in a vacuum insulated container such as a metal thermos flask. This concerns the structure of the mouth.

"Prior Art" Conventionally, a metal thermos flask as shown in FIG. 2 has been known as one type of metal double container.

The metal thermos flask 1 has an outer cylinder 2 and an inner cylinder 3 made of stainless steel, each having openings 2a and 3a.
Both mouth parts 2a, 3a are overlapped with each other at
It has a mouth structure in which the peripheral walls 4 and 5 forming the opening are airtightly integrated by Teig welding, MIG welding, or seam welding.

``Problems to be Solved by the Invention'' The present invention attempts to solve the following problems in the conventional technology described above.

If all of the inner and outer cylinders, which make up most of the metal thermos flask 1, are made of stainless steel, the product cost will likely increase because stainless steel itself is expensive.

In order to eliminate the above-mentioned problems, the outer cylinder 2 is made of mild steel, which does not require as much corrosion resistance as the inner cylinder 3 that comes into direct contact with the contents, or the outer cylinder 2 is less likely to be directly affected by external force. It is possible to form the inner cylinder 3 with a thinner wall, but in the former case, it would be a special weld between different metals, or the inner cylinder 3, which is made of stainless steel, would be diluted during welding. Corrosion resistance may deteriorate. In addition, the inner and outer cylinders 2 and 3 are originally thin-walled, and if mild steel, which has lower strength, is used in addition to this, the shape of the disc electrode 6 during seam welding as shown by the arrow in FIG. If the mouth portions 2a, 3a are deformed by the pressure and the roundness of the mouth portions 2a, 3a is disrupted, new problems arise. As shown in Fig. 2, such a problem may deteriorate the sealing performance of the gasket 7 that is brought into contact with the outer circumferential surface of the opening 2a of the outer cylinder 2 when assembled as a product, so that it cannot be fixed later. It is necessary to make corrections depending on the process. On the other hand, in the latter case, due to the difference in wall thickness, the strength decreases as in the former case, and the circularity of the openings 2a, 3a is likely to be lost during seam welding as described above.

When performing seam welding, the relationship between welding conditions such as the pressure applied by the disc electrode 6 and the welding current must be strictly controlled, but due to the above-mentioned problems, the pressure applied is limited. The welding current obtained becomes unstable, causing spatter to fly off, which tends to cause leaks that damage the vacuum layer.

If residual stress occurs after welding, it tends to accelerate corrosion, so it is necessary to perform heat treatment to stabilize it.
If they are made of different metals, there is a risk of cracking due to the difference in thermal expansion coefficient between the two.

The welded portion between the outer cylinder 2 and the inner cylinder 3 is formed by supporting the inner cylinder 3 with a cantilever structure.
External forces tend to concentrate during vibrations and shocks, so it is necessary to sufficiently increase the strength. However, if the outer cylinder 2 is made of mild steel, it will become thinner due to the pressing force of the disc electrode 6, and the nugget part will be coated with marten. Site structure may occur and become brittle, and as a result, sufficient strength may not be obtained.

"Means for Solving the Problems" The present invention aims to provide a mouth structure for a metal double container that can effectively solve the problems in the conventional technology described above. , an insert metal made of a plating layer is formed on at least one wall surface of the outer surface of the circumferential wall of the mouth of the inner cylinder and the inner surface of the circumferential wall of the mouth of the outer cylinder, and the insert metal made of the plating layer is formed on the mouth of the inner cylinder through the insert metal of the outer cylinder. These are integrated by seam welding with the mouths fitted.

"Function" The opening structure of the metal double container according to the present invention is as follows:
The insert metal interposed between the mouth of the inner cylinder and the mouth of the outer cylinder ensures the strength of the fitting part of both mouths and prevents deformation, and also prevents deformation of the fitting part of both cylinders. To prevent dilution of one of the cylinders during welding, and to form an insert metal interposed between the mouths of both cylinders as a plating layer on at least one wall surface of both cylinders. This reduces the pressure applied during seam welding as much as possible. In addition, by forming an insert metal made of a plating layer on at least one wall surface of both cylinders, it is possible to eliminate the positional deviation of the insert metal when the inner cylinder and outer cylinder are assembled and fitted. Unlike a piece of insert metal, the inner cylinder and outer cylinder can be easily assembled, and the insert metal can be positioned reliably.

"Embodiment" Hereinafter, a preferred embodiment of the present invention will be described based on FIG. 1.

This embodiment is applied to a metal thermos flask 8 in the same way as in FIGS. 2 and 3, and includes an outer cylinder 9 made of mild steel, an inner cylinder 10 made of stainless steel, and It has an insert metal 11 interposed between an outer cylinder 9 and an inner cylinder 10, and has a general configuration in which the insert metal 11, the outer cylinder 9, and the inner cylinder 10 are integrated by seam welding. .

The outer cylinder 9 has an opening 9a at one end, and the opening 9 has a mouth 9a at one end.
A is formed by a peripheral wall 12 that is straight or tapered to have a diameter that gradually becomes smaller toward the outside.

The inner cylinder 10 has a mouth 10a at one end, and the mouth 10a is formed by a peripheral wall 13 having a smaller diameter than the inside diameter of the mouth 9a of the outer cylinder 9.

On the other hand, in this embodiment, the insert metal 11 is formed by forming a plating layer in an annular shape on the wall surface of at least one of the outer cylinder 9 and the inner cylinder 10, and between each of the outer cylinder 9 and the inner cylinder 10. In addition, the material of the insert metal 11 is determined by the bondability between the mild steel and stainless steel, which are the constituent materials of the outer cylinder 9 and the inner cylinder 10, and the composition of the two metals (particularly the carbon content). ) They are selected based on differences in melting point or electrical properties, but copper or its alloys are an example, and in particular copper has an electrical resistance about 4 to 5 times that of iron, and a melting point of 900℃.
Copper-manganese (Cu-Mn) alloys, which have a lower hardness than iron, are preferred.

The outer cylinder 9, inner cylinder 10, and insert metal 11 formed in this way are
can be reliably fixed and arranged between the inner cylinder 10 and the peripheral wall 12 of the outer cylinder 9, and as a result, the positions and shapes of these three parts can be maintained and assembled in a close contact state.

Then, when seam welding is performed by applying a welding current while pressing the disk electrode 6 to the above-mentioned opening part from the inside and outside as shown in FIG. Insert metal 11 starts melting first and outer cylinder 9 and inner cylinder 1
0 and the opening of the metal thermos flask 8 is formed.

During such a mouth forming operation, an insert metal 11 is interposed at the welding location and the insert metal 11 acts as a reinforcing member;
In addition, since the outer cylinder 9 and the inner cylinder 10 are pressed against the insert metal 11, the pressing force during seam welding is reduced by the pressure, and the outer cylinder 9 and the inner cylinder Even when the outer tube 10 is thin and the outer tube 9 is made of mild steel, the deformation of the openings 9a and 10a of the outer tube 9 and the inner tube 10 is suppressed and the roundness is maintained. Then, an insert metal 11 is installed on the peripheral wall surface of the opening between the outer cylinder 9 and the inner cylinder 10.
By forming the plating layer in advance as a plating layer, the interfacial resistance is made uniform, making it easy to control the pressing force applied during seam welding, and in conjunction with this, it also becomes easy to control the welding current. As a result, nuggets are formed at appropriate positions within the joint interface formed by the outer cylinder 9, inner cylinder 10, and insert metal 11, and the occurrence of spatter is suppressed. Furthermore, the insert metal 11 interposed between the outer cylinder 9 and the inner cylinder 10 suppresses the dilution phenomenon between the inner cylinder 10 made of stainless steel and the outer cylinder 9 made of mild steel.

Therefore, due to these synergistic effects, even when the outer cylinder 9 of the metal thermos flask 8 is made of mild steel, the mouth part can be manufactured easily, and leakage and corrosion resistance can be reduced. This improves the yield, ensures the positioning of the insert metal 11 at the container mouth, and facilitates the assembly work of the outer cylinder 9 and the inner cylinder 10, thereby reducing product costs. be able to.

Note that the shapes, dimensions, materials, etc. of each component shown in the above embodiments are merely examples, and can be variously changed based on design requirements and the like. for example,
The cylinders 9 and 10 may be made of the same metal instead of different metals, and the same effect can be obtained even if one of the cylinders is thinner than the other. Further, the insert metal 11 has a plating layer on at least one wall surface of one or both of the outer surface of the peripheral wall 13 forming the opening 10a of the inner cylinder 10 or the inner surface of the peripheral wall 12 forming the opening 9a of the outer cylinder 9. Of course, it would be better if it was formed by forming.

"Effects of the Invention" As explained above, the mouth structure of the metal double container according to the present invention provides the following excellent effects.

An insert metal is interposed in the fitting part between the mouth of the outer cylinder and the mouth of the inner cylinder, and seam welding is performed at the fitting part, so the outer cylinder and the inner cylinder are formed with thin walls. To prevent the deformation of the inner and outer cylinders against the pressure applied during seam welding even in the case of seam welding.

Since the insert metal is formed as a plating layer on the wall surface of at least one of the outer cylinder and the inner cylinder, and seam welding is performed with these parts pressed together, the three parts are integrated. This makes it possible to make the interfacial resistance uniform, which in turn makes it easier to control the pressing force and applied welding current during seam welding. In addition, by interposing a plated layered insert metal, the inner cylinder mouth, insert metal, and outer cylinder mouth can be fitted more tightly than when using a metal piece insert metal, so that the applied current during seam welding can be interrupted. The stability of seam welding can be improved, and a uniform joint without leakage can be achieved. Therefore, in a metal double container formed by joining an inner cylinder and an outer cylinder at the mouth, the most important part, the airtight structure of the mouth, can be made completely leak-free.

According to the above, the nugget can be formed at an appropriate position within the bonding interface, and the occurrence of spatter can be suppressed.

Even when both cylinders are formed of a combination of different metals such as mild steel and stainless steel, a dilution phenomenon between the cylinders is suppressed by an insert metal to prevent deterioration of the corrosion resistance of the stainless steel.

Unlike insert metal, which is a metal piece, by arranging the insert metal as a plating layer, the position of the insert metal is reliably fixed, making it easier to assemble the inner and outer cylinders,
Moreover, due to the synergistic effect of the above-mentioned ~, it is possible to manufacture products with high manufacturability and high quality at a high yield.

Furthermore, since the insert metal made of a plating layer is formed on at least one of the inner surface of the peripheral wall of the mouth of the outer cylinder and the outer surface of the peripheral wall of the mouth of the inner cylinder, the insert metal is formed on the outer cylinder before assembling the outer cylinder and the inner cylinder. and at least one of the outer surface of the mouth of the inner cylinder. Then, when assembling the outer cylinder or inner cylinder with insert metal, even if there is resistance when fitting the outer cylinder and the inner cylinder, the plating layer will not shift its position, and the plating layer will not shift the position of the outer cylinder. The insert metal can be positioned accurately and reliably even during the assembly and fitting process of the outer cylinder and inner cylinder because it makes sure contact with the predetermined position on the inner surface of the mouth peripheral wall and the predetermined position on the outer surface of the mouth peripheral wall of the inner cylinder. This has the effect of producing a reliable seam weld as described above.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main part showing an embodiment of the present invention, Fig. 2 and Fig. 3 show an example of the structure of a metal double container, and Fig. 2 is a cross-sectional view of the main part. Third
The figure is a schematic explanatory diagram showing a method of welding the mouth part. 8... Metal thermos flask, 9... Outer tube, 9a... Mouth, 10... Inner tube, 10a... Mouth, 11... Insert metal, 12, 13... Surrounding wall.

Claims (1)

[Claims for Utility Model Registration] A metal double cylinder comprising an inner cylinder and an outer cylinder made of metal, a vacuum layer formed between the inner cylinder and the outer cylinder, and the inner cylinder and the outer cylinder being joined at their mouths and maintained under vacuum. In the mouth structure of a heavy container, an insert metal comprising a plating layer is formed on at least one of the outer surface of the mouth peripheral wall of the inner cylinder and the inner surface of the mouth peripheral wall of the outer cylinder, and the plating layer is formed on the mouth of the inner cylinder. 1. A mouth structure for a double metal container, characterized in that the mouth of an outer cylinder is fitted through an insert metal made of metal and integrated by seam welding.