JPH0233373B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal thermos flask, which enables a metal thermos flask with improved heat insulation performance to be obtained through a process that is almost the same as the conventional method.

Conventionally, in a metal thermos flask consisting of an inner cylinder and an outer cylinder, with a vacuum insulation layer between the inner and outer cylinders, a shield is placed in the vacuum insulation layer to prevent heat loss or heat intrusion due to radiation between the inner and outer cylinders. Methods of reducing radiation and heat transfer by interposing a plate, filling the vacuum insulation layer with powder such as perlite, or stacking aluminum vapor-deposited films in multiple layers within the vacuum insulation layer are well known. However, with this conventional method, several manufacturing processes are carried out separately, which makes the design complicated, and the cost increases due to high material costs. There was an inconvenience.

This invention was made in view of the above circumstances,
The purpose is to provide a method for manufacturing a metal thermos flask with low manufacturing cost, easy manufacturing, and high heat generation performance. In this invention, the method for manufacturing a metal thermos flask is
A metal thermos bottle shell consisting of a metal inner cylinder and an outer cylinder with exhaust holes provided on either side is heated under vacuum to create a vacuum insulation layer between the inner and outer cylinders, and the holes are filled with metal wax. In a method for manufacturing a metal thermos flask that is vacuum-sealed with a sealing member using Vacuum heat treatment is performed at a temperature above the melting temperature of the metal wax and at a temperature below the melting temperature of the dissimilar metal, and the above-mentioned hole is vacuum-sealed to form a vacuum insulation layer and the dissimilar metal is fixed to the inner and outer cylinder surfaces. At the same time, the heat-evaporated dissimilar metal molecules or atoms form a highly reflective dissimilar metal thin film layer on the surfaces of the inner and outer cylinders on the vacuum insulation layer side to make them mirror-like.

The present invention will be explained below with reference to the drawings. In FIG. 1, reference numeral 1 indicates a metal thermos flask shell, and this shell 1 is composed of an inner tube 2 and an outer tube 3 made of metal. These inner and outer cylinders 2 and 3 are usually made of stainless steel and are joined to each other at their upper parts. Further, a hole 4 for evacuation is formed at the bottom of the outer cylinder 3 with an appropriate diameter. At the top of this hole 4 (between the inner cylinder 2 and outer cylinder 3),
As a sealing member, a sealing plate 5 having a diameter slightly larger than the diameter of this hole 4 is installed via a metal solder 6 in the form of a rod or powder. The sealing plate 5 is made of the same material as the inner and outer cylinders 2 and 3, and is used to close the hole 4 with a metal solder 6 during heating under vacuum, as will be described later. The inner surface of each of the inner cylinder 2, outer cylinder 3, and sealing plate 5, that is, the entire inner peripheral surface of the shell 1, is made of metal such as gold or copper, which has a lower emissivity than the metal (stainless steel) constituting the shell 1. A dissimilar metal 7 such as nickel, tin, or the like is coated by plating, vapor deposition, coating, or the like. When the shell 1 thus constructed is placed in a vacuum heating furnace and subjected to vacuum heating treatment, the atmosphere between the inner cylinder 2 and the outer cylinder 3 is exhausted through the hole 4 at the bottom of the outer cylinder 2. Next, the metal solder 6 is heated to the melting temperature of the solder metal 6, and as shown in FIG. A heat insulating layer 8 is formed. Through this heat treatment, the dissimilar metal 7 is more firmly attached to the inner circumferential surface of the shell 1, and the dissimilar metal 7 is heated to a temperature higher than the melting temperature of the metal solder 6.
When heated to a temperature below the melting temperature of dissimilar metal 7
evaporates, and the metal molecules or atoms float inside the vacuum insulation layer 8. Thereafter, when the shell 1 is slowly cooled under vacuum, the metal wax 6 solidifies, and the evaporated molecular or atomic dissimilar metal 7 re-attaches (evaporates) to the inner surface of the shell 1, resulting in reflectance. A dissimilar metal thin film layer with a highly uniformly mirrored surface is formed. This redeposition is done evenly and gradually by molecular or atomic metals, so
Not only the surfaces of the inner and outer cylinders 2, 3 and the sealing plate 5, which were previously coated with the dissimilar metal 7, but also the entire surface of the sealing plate 5 and the metal solder 6 facing the vacuum insulation layer 8 are coated with an extremely fine-grained mirror surface 9. is formed.

The metal thermos flask thus formed has a dissimilar metal 7 with a low emissivity coated on the inner surface of the shell 1 and the sealing plate 5 on the vacuum insulation layer 8 side. Heat radiation directed from the outer cylinder 3 into the vacuum insulation layer 8 can be suppressed to a low level, and the heat retention or cold retention performance of the thermos flask can be improved. In addition, the heat radiation slightly emitted from the inner tube 2 and outer tube 3 through the dissimilar metal 7 into the vacuum insulation layer 8 is reflected by the finely textured mirror surface 9, so that the thermos can be kept warm. Alternatively, the cold storage performance can be further improved. especially,
According to the manufacturing method of the present invention, parts of the inner surface facing the vacuum heat insulating layer 8 that have not been coated with the dissimilar metal 7 before the vacuum heat treatment, that is, the end face of the sealing plate 5 and the surface of the metal solder 6 Also,
Finely textured mirror surface made of metal with low emissivity 9
can be easily formed. Therefore, even if the sealing plate 5 and the metal solder 6 are made of a metal with high emissivity, the mirror surface 9 suppresses heat radiation toward the vacuum insulation layer 8 and prevents heat radiation inside the vacuum insulation layer 8. Since a very small amount of heat radiation emitted by the thermos can be reflected, this also makes it possible to further improve the heat retention and cold retention performance of the thermos flask. Further, according to the manufacturing method of the present invention, the formation of the vacuum heat insulating layer 8 and the formation of the mirror surface 9 can be performed simultaneously, so that the work can be simplified and simplified. Further, since materials such as a shielding plate and an aluminum vapor-deposited film are not required, manufacturing costs can be reduced.

In order to investigate the heat retention performance of the metal thermos manufactured as described above, the same amount of boiling water in the same container (kettle) was poured into each thermos of the above structure and a conventional thermos of the same size, and 24 hours later. When we measured the water temperature, we got the following results.

〔Measurement result〕

Water temperature after 24 hours Conventional product: 54°C Thermos manufactured by this method: 64°C As described above, the thermos manufactured by the method for manufacturing a metal thermos according to the present invention has clearly demonstrated its heat retention performance. It turned out that it was improving.

As explained above, the method for manufacturing a metal thermos flask according to the present invention involves coating the inner and outer cylinders and the surface of the sealing member on the vacuum insulation layer side with a dissimilar metal having a low emissivity such as copper, and then forming a shell consisting of the inner and outer cylinders. By heating under vacuum, a vacuum insulation layer is formed between the inner and outer cylinders, and at the same time, the dissimilar metals are firmly attached to the inner surfaces of the inner and outer cylinders, and the molecules or atoms of the dissimilar metals evaporated by heating are removed from the inner and outer cylinders. Since it is attached to the entire inner surface facing the vacuum insulation layer of the sealing member and metal wax to form a mirror-like dissimilar metal thin film layer, a metal thermos flask with high insulation performance can be easily manufactured at low manufacturing cost. .

[Brief explanation of drawings]

Figures 1 and 2 are for explaining the method for manufacturing a metal thermos flask according to the present invention. FIG. 1 is a configuration diagram of a metal thermos flask manufactured by the manufacturing method of the invention. 1... Shell body, 2... Inner cylinder, 3... Outer cylinder, 4... Hole, 7...
Dissimilar metal, 8...Vacuum insulation layer, 9...Mirror surface.

Claims (1)

[Claims] 1 A metal thermos bottle shell consisting of a metal inner cylinder and an outer cylinder with exhaust holes provided on either side is heated under vacuum to create a vacuum insulation layer between the inner and outer cylinders, and the holes are filled with metal wax. In the method for manufacturing a metal thermos flask that is vacuum-sealed with a sealing member through a vacuum insulation layer, the inner and outer cylinders and the surfaces of the sealing member on the vacuum insulation layer side are coated in advance with a dissimilar metal having a low emissivity such as copper, Vacuum heat treatment is performed at a temperature above the melting temperature of the metal solder and at or below the melting temperature of the dissimilar metal, and the above hole is vacuum sealed to form a vacuum insulation layer and the dissimilar metal is fixed to the inner and outer cylinder surfaces. A metal product characterized in that the surfaces of the inner and outer cylinders on the vacuum insulation layer side are mirror-finished by forming a thin film layer of different metals with high reflectance by the molecules or atoms of the different metals heated and evaporated. How to make a thermos flask.