JPH02169184A - Vacuum sealing device for metal tubes - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a device for vacuum sealing the inside of a container.

In particular, the present invention relates to a device suitable for vacuum-sealing the inside of a container to a predetermined degree of vacuum without variation.

[Conventional technology]

A conventional device is described in Japanese Patent Application Laid-Open No. 56-63780, and as shown in FIG. 1, a vacuum source 15 is attached to the tip of a metal tube 2 for sealing. as well as.

After evacuating the storage tank 1 beyond that, sealing gold gtM? is sandwiched between the pressure heads 5 and the walls of the tube are brought into close contact.

It is heated with electricity and vacuum sealed. In addition to this,
A related example is Japanese Patent Application Laid-Open No. 58-154464, which first applies a solvent to the inner wall of the pipe and performs welding and sealing using the same procedure.

[Problem to be solved by the invention]

The above-mentioned conventional technology is a sealing metal tube and this metal tube.

Also, no consideration was given to the connection method to the vacuum source that evacuates the storage tank, resulting in (1) leaks at the connection, (2) tedious connections, making automation difficult, and (3) sealing. The stop metal pipe becomes longer.

There was a problem.

That is, in the known example shown in FIG. 3, a sealing metal tube 2 is inserted into a vacuum connection port 20, and air is supplied from an air pressure source 19 to an elastic sealing member 18 to inflate it around the outer circumference of the metal tube. After temporarily sealing, the metal tube 2. Container 3 consisting of storage tank 1
Vacuum. Thereafter, after reaching a predetermined degree of vacuum, the metal tube 2 is sandwiched between the pressurizing heads 5 and the walls of the tubes are brought into close contact with each other, and then the walls are welded and vacuum sealed.

However, with this method, (1) Although the space between the metal tube and the metal tube is temporarily sealed with an elastic sealing member, the outer diameter and surface roughness of the metal tube must be processed with high precision.
Temporary sealing is difficult, and even after sealing, vacuum sealing may not be possible and air may remain in the storage tank. Further, when inserting the metal tube into the elastic sealing member 18, there is a risk that the elastic sealing member may be damaged by the end face of the metal tube, and the tube may be sealed without reaching a predetermined degree of vacuum.

Machining the outer periphery of a metal tube to make the outer diameter uniform and the surface roughness highly accurate requires a large amount of man-hours.

(2) When sealing, it is necessary to crush the metal tube and bring the tube walls into close contact with each other; 1. The elastic sealing member 18 and the metal tube 2.
The temporary sealing position must be far enough away from the sealing position of the metal tube by the pressure head, and must be in a position where the metal tube cannot be deformed even if it is crushed, and the metal tube for sealing must be long. I don't get it.

(3) There is also a method of connecting a vacuum source and a metal tube using a threaded joint, but this method has problems in that it lacks reliability against vacuum and ease of operation.

(4) In addition, when welding, the inner surface of the metal tube was in vacuum and the outer surface was at atmospheric pressure, so there was a risk that the molten metal would drop when the gold was melted, resulting in defective welding.

(5) Furthermore, when the pressure head is energized and the metal tube walls are welded, there is a problem in that the pressure head overheats, metal is welded, and welding becomes unstable thereafter.

The purpose of the present invention is to: (1) always maintain a vacuum-sealed container at a constant predetermined degree of vacuum;
(2) Eliminate the pressure difference between the inner and outer surfaces of the metal tube in contact with the ifl.

The purpose is to prevent melt from dripping during metal melting and to prevent welding defects. (3) The purpose is to prevent metal from adhering to the pressure head when welding metal pipes and to perform stable weld sealing. .

[Means to solve the problem]

The above purpose is to store the substance to be stored in the container. A container made up of metal tubes attached to the top of the tank and storage tank is placed into a vacuum container through an opening/closing door, and the inside of this vacuum container is evacuated to achieve a predetermined degree of vacuum inside and outside the container. This is accomplished by crimping the tubes with a pressure head inside a vacuum container and welding them under appropriate energization and pressure conditions.

[Effect]

Containers are taken in and out through the opening/closing door of the vacuum container.

Depending on the degree of vacuum required, the opening/closing door can be selected from 4 highly reliable and reliable sealing mechanisms. There is no variation in the degree of vacuum.

Since it is placed in a vacuum container and evacuated, there is no need to connect it to a vacuum source every time the sealed container is replaced. Moreover, it is therefore not necessary to add the metal tube with high precision. Furthermore, the gold 5c tube only needs to be long enough to be welded once after crimping.

Since the inside and outside of the metal tube is vacuumed, there is no pressure difference between the inside and outside, so even in the case of thin-walled metal tubes, when welding all 5I tubes, all the molten metal will not drop, and the range of welding conditions is wide. Become.

After setting the degree of vacuum inside and outside the container to be sealed to the specified value, adjust the pressure of the pressurizing cylinder, the pressurizing time, the amount of energization, the energizing time, and the timing of energizing and pressurizing. , to prevent the pressure spatula 1- from overheating and to prevent metal from welding to the pressure head.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

A pressure head 5 for applying ff1l'+ at the time of welding is arranged opposite to sandwich the metal tube 2 of the container 3 to be vacuum sealed, and this pressure head 5 is attached to the tip of the slide rod. ing. The slide rod 6 is supported by an electrode bearing 11, and an O-ring 9 is installed between the electrode bearing 11 and the slide rod. A vacuum vessel flange 12 is installed on the vacuum vessel 4, and an electrode portion bearing 11 is attached to the flange 12N via an insulating spacer 10 made of Teflon. Vacuum vessel flange 12. An O-ring 8.7 is attached to the electrode bearing 11 for sealing. A pressure cylinder 13 is attached to the rear end of the slide rod 6, and a welding power source 14 is connected thereto.

An opening/closing door 17 for taking in and out the container 3 to be sealed is attached to the end face of the vacuum container 4, and is sealed with an O-ring 17 inserted between the opening and closing doors 17. Further, the vacuum container 4 is permanently connected to a vacuum pump 15 which is a vacuum source.

The container 3 inserted into the vacuum container 4 from opening/closing of the vacuum container B%17 is evacuated by the vacuum pump 15, and as the inside of the vacuum container 4 is evacuated, the storage tank 1° of the container 3 and the metal tube 2 for sealing are also evacuated. becomes. When a predetermined degree of vacuum is obtained, first, the pressurizing cylinder 13 is activated, and the slide rod 6 slides inside the electrode bearing 11.

The pressure head 5 at the tip of the slide rod 6 presses the sealing metal tube 2 from the left and right to bring the metal tube walls into close contact. after that,
The metal tube 2g is welded by applying electricity from the power source 14 while applying pressure. The welding power source 14 is connected to the slide rod 6, and since the slide rod 6 is electrically insulated from the vacuum vessel 1 by the insulating spacer 10, the welding current is transmitted from the welding power source 1 to the metal tube through the slide rod 6. 2. Opposite pressure head 5. It flows and is welded to the slide rod 6.

Pressure force when welding metal tubes, pressurization time 1 energization amount 2 energization time 9
The timing and interval of energization and pressurization are carried out according to the pattern shown in Fig. 2. After contacting the cutting head with the metal tube, the -th energization is performed, and after the first energization is temporarily stopped in a pressurized state, the second energization is performed.

Even after the second energization is stopped, the welded part is cooled while being pressurized. - By stopping the energization after completing the energization of the same port, the temperature of the pressure head is reduced to F to prevent overheating. Also, cooling under pressure prevents welding deformation and springback.

According to this embodiment, the insulating spacer 10 performs electrical insulation and vacuum sealing, and by bringing the pressurized cylinder out of the vacuum container 4, the size of the vacuum container is reduced to the size of the metal container to be sealed. On the other hand, it is possible to make the size of the container efficient so as not to make it excessively large, and it is possible to reduce the cost of manufacturing the container and to facilitate vacuum evacuation.

[Effects of the Invention] According to the present invention, it is possible to maintain a stable vacuum state inside the container at all times, and it is possible to manufacture a container with a highly accurate degree of vacuum after vacuum sealing.

When vacuum-sealing, it is not necessary to connect each container to a vacuum source, which eliminates the need for complicated operations and high-precision processing of metal tubes, making it easier to automate production and reduce processing man-hours.

The metal pipe for connection can be shortened, and many sealed containers can be stored in a small space.

This has the effect of increasing the reliability of vacuum sealing.

Further, by selecting the pressure 1 energization conditions, it is possible to prevent metal from melting into the pressure head.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a diagram showing the pressurization and energization conditions of FIG. 1, and FIG. 3 is a sectional view of a conventional example. 1... Storage tank, 2... Metal tube for sealing, 3... Container, 4
...Vacuum container, 5...Pressure head, 6...Slide rod, 7.8, 9.17...○ ring, 10...
Insulating spacer, 11... Electrode part bearing, 12... Vacuum vessel flange, J3 - Pressure cylinder, 14... Welding power source, 15... Vacuum source, 16... Opening/closing, 17... Elastic sealing Element. 1 pneumatic source, 20...metal tube insertion port.

Claims (1)

[Scope of Claims] 1. In an apparatus for vacuum sealing a container having a metal tube as a vent, the container is placed in a vacuum container and the inside of the vacuum container is evacuated to seal the container. 1. A vacuum sealing device for a metal tube, comprising: means for evacuating the metal tube; means for energizing and crimping the metal tube; and means for controlling these. 2. A patent characterized in that the welding conditions are applied pressure, pressurization time, energization amount, energization time, timing of energization and pressurization, and interval after evacuation so that the degree of vacuum reaches a predetermined value. The vacuum sealing device according to claim 1.