JPS63297898A - Manufacture of vacuum structure member - Google Patents

Abstract

PURPOSE:To make it possible to carry out the fixing work of a lid for a vacuum container under the atmospheric pressure by returning the pressure of a vacuum tank to the atmospheric pressure after the container provided with the lid is evacuated in the vacuum tank so that the lid is pressed by the atmospheric pressure in order to maintain a vacuum in the container. CONSTITUTION:After a lid 3 is set on a container body 2 through the intermediary of an O-ring 4 while a gap is left therebetween, they are all disposed in a vacuum tank so as to be evacuated in order that a vacuum is effected in the container body 2. When the pressure of the vacuum tank is returned at once to the atmospheric pressure, the lid 3 is pressed against the container body 2 by the atmospheric pressure, and accordingly, a vacuum condition is maintained in the container body 2 by the sealing action of the O-ring 4. Finally, the lid 3 is fastened to the container body 2 by screws.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for easily manufacturing a vacuum structure without requiring work in a vacuum.

[Conventional technology]

A vacuum structure with a vacuum inside can be obtained by placing the entire structure in a vacuum atmosphere and sealing the structure using an O-ring or welding, or by evacuating the structure through a pipe attached to the structure. It was manufactured by sealing off the pipe and creating a vacuum inside.

FIG. 4 shows several examples of this conventional manufacturing method.

In FIG. 3A, the entire structure 1 is placed in a vacuum atmosphere, and the container body 2 and the lid 3 are screwed together via an O-ring 4 in this state. In the case of FIGS. 1 and 2), the container body 2 is sealed by welding the lid 3 to the container body 2 through fillet welding 5 in a vacuum atmosphere. Further, in FIG. 3C, the lid 3 provided with the vibro is welded 5 to the container body 2 in an atmospheric atmosphere to make the connection between the container body 2 and the lid 3 airtight. Next, a vacuum is drawn through the vibro, and the vibro is sealed off while the inside of the container body 2 is evacuated. The base of the vibro is also welded to the lid 3 by fillet welding 5.

[Problem that the invention seeks to solve]

When manufacturing a vacuum structure by the method shown in FIGS. 4(a) and 4(b), it is necessary to perform operations such as screw tightening and welding in a vacuum atmosphere. Therefore, large-scale equipment is required, and the work itself becomes complicated. On the other hand, Fig. 4 (
When method C) is used, the sealed vibro remains as a convex portion on the vacuum structure. This convex portion becomes a hindrance when the vacuum structure is incorporated into other equipment, and imposes restrictions on layout and the like.

Therefore, the present invention was devised to solve such problems, and by utilizing the force applied to the vacuum structure when the vacuum chamber is returned from vacuum to atmospheric pressure, it is possible to The purpose is to enable sealing and fixing work and to facilitate the manufacture of vacuum structures.

[Means for solving problems]

In order to achieve the objective, the method for manufacturing a vacuum structure of the present invention maintains a minute gap between the lid of the vacuum structure and the container body, and interposes an O-ring in the gap. After the vacuum structure is evacuated in a vacuum chamber, the vacuum chamber is returned to atmospheric pressure and the lid is pressed against the container body, and then the lid is screwed onto the container body and sealed and fixed by welding or the like. It is characterized by

Here, it is also possible to apply pressurization to the lid when returning the vacuum chamber to atmospheric pressure, and to release the pressurization when the inside of the vacuum chamber reaches atmospheric pressure.

〔Example〕

Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.

FIG. 1 is a diagram for explaining a method for manufacturing a vacuum structure according to a first embodiment of the present invention.

In this example, the vacuum structure 1 adopts a structure in which the inside is completely sealed by screwing the lid 3 to the container body 2 via the O-ring 4. The gap between the container body 2 and the lid 3 is maintained at approximately several tens of micrometers, and the lid 3 is set to be able to move up and down freely. While maintaining this gap, the entire container is placed in a vacuum chamber with the O-ring 4 interposed between the container body 2 and the lid 3, and the inside of the container body 2 is evacuated. At this time, the air inside the container body 2 is exhausted to the outside through the gap between the container body 2 and the lid 3, and the inside of the container body 2 becomes completely vacuumed. Next, when the vacuum chamber is returned to atmospheric pressure at once, the lid 3 is pressed against the container body 2 with a force of 1 atmosphere, and the inside of the container body 2 continues to be kept in a vacuum state by the seal of the O-ring 4. Therefore, the lid 3 is firmly fastened to the container body 2 using bolts 7 or the like. In this way, the vacuum structure 1 can be easily obtained without requiring any screw-fastening work within the vacuum chamber.

FIG. 2 is a diagram for explaining a second embodiment of the present invention.

In this example as well, the lid 3 is connected to the container body 2 via the O-ring 4.
Place the whole thing in a vacuum chamber with the setting set to . In this case, as in the first embodiment, the gap between the container body 2 and the lid 3 is maintained at approximately several tens of μm. After the air inside the container body 2 is exhausted, the vacuum chamber is returned to atmospheric pressure and the lid 3 is pressed against the container body 2. Next, the container body 2
The lid 3 is firmly attached to the container body 2 by sealing welding 8 between the lid 3 and the lid 3. In this example, compared to the case shown in FIG. 1, there is no need to form a flange on the container body 2 for fastening the bolt 7, so the vacuum structure 1 becomes compact.

FIG. 3 is a diagram illustrating a third embodiment.

In this example, an O-ring 4 is provided between the container body 2 and the lid 3.
The whole assembly is placed in a vacuum chamber 9 and evacuated to an ultra-high vacuum. Then, while pressurizing the lid 3 with the linear introduction device 10, the vacuum chamber 9 is returned to atmospheric pressure at once. Because of this pressurization, when the vacuum chamber 9 is returned to atmospheric pressure, the vacuum structure 1 can be maintained at an ultra-high vacuum without air being mixed into the container body 2. Even if pressurization is subsequently released, the lid 3 is pressed against the container body 2 by atmospheric pressure, and the vacuum structure l
The internal vacuum remains intact. In this state, when the lid 3 is sealed and fixed to the container body 2 by screwing, welding, etc.,
An ultra-high vacuum vacuum structure 1 is manufactured.

〔Effect of the invention〕

As explained above, in the present invention, after evacuation is performed in the vacuum chamber, by returning the vacuum chamber to atmospheric pressure,
The lid of the vacuum structure is pressed against the container body, and in this state, the lid is fixed to the container body. Therefore, a vacuum structure can be easily obtained without requiring work such as screw tightening or welding in a vacuum chamber. Therefore, production costs, equipment, etc. can be simplified, and product reliability can be improved. Furthermore, since no vacuum pipe is attached, the resulting vacuum structure has no protrusions, which reduces restrictions when incorporating it into other equipment.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the first embodiment of the present invention.
3 and 3 are diagrams for explaining the second and third embodiments, respectively. On the other hand, FIG. 4 is a diagram illustrating various conventional methods for manufacturing a vacuum structure. 1: Vacuum structure 2: Container body 3: Lid 4: 0 ring 5: Fillet weld 6: Pipe 7: Bolt
8: Sealing welding 9: Vacuum chamber 10: Straight line introduction machine patent applicant Yasuyo Electric Manufacturing Co., Ltd. Agent
Masu Kobori (2 idiots) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. The vacuum structure is evacuated in a vacuum chamber with a minute gap maintained between the lid of the vacuum structure and the container body, and an O-ring interposed in the gap. After performing the above, the vacuum chamber is returned to atmospheric pressure, the lid is pressed against the container body, and the lid is then screwed onto the container body and hermetically fixed by welding or the like. Method. 2. A vacuum structure characterized in that pressurization is applied to the lid when the vacuum chamber according to claim 1 is returned to atmospheric pressure, and the pressurization is released when the inside of the vacuum chamber reaches atmospheric pressure. How the body is manufactured.