DE112021007922T5 - METHOD FOR MANUFACTURING A VACUUM VALVE - Google Patents

Abstract

In an object of achieving a low-cost vacuum valve, there is provided a method of manufacturing a vacuum valve, whereby an intermediate assembly of a vacuum valve, which is formed by connecting a fixed-side end plate (2) and a moving-side end plate (3) by brazing each to a respective end of a cylindrical insulating chamber (1), is arranged in a mold (12, 14), and whereby an insulating resin layer (9) is formed by molding an insulating resin material in an outer periphery of the intermediate assembly, characterized in that a region of an outer edge portion of the fixed-side end plate (2) is formed such that a stress generated in a brazed portion (10) between the insulating chamber (1) and the fixed-side end plate (2) when the insulating resin material (13) is molded in the outer periphery of the intermediate assembly is smaller than an allowable stress of the brazed portion (10).

Description

Technical area

The present application relates to the field of a method for producing a vacuum valve.

Technological background

A method whereby an outer peripheral portion of a vacuum valve is molded using an insulating resin and the vacuum valve is closed, and whereby insulation is strengthened along an outer peripheral portion surface of the vacuum valve by increasing a creepage distance, has been used to improve an insulating performance of a vacuum valve. When an outer peripheral portion of a vacuum valve is molded from an insulating resin in this manner, it is necessary to consider a generated stress applied to the vacuum valve, and to date, a mold has been used (see, for example, Patent Literature 1) in which an insulating resin material that liquefies at a high temperature is poured into a mold and the resin is hardened by cooling it.

Quotation list

Patent literature

PTL1: JP2013-93276A

Summary of the invention

Technical problem

However, although the mold used to mold a vacuum valve from an insulating resin is such that a generated stress acting on the vacuum valve when it is manufactured is small, it is necessary to wait until the high-temperature resin poured into the mold cools to form the outer peripheral portion. Therefore, there is a problem that the time taken by the mold and other manufacturing equipment for manufacturing a vacuum valve is long, that a manufacturing lead time is several hours to one day, that a manufacturing cycle is long, and that the manufacturing cost is high.

The present application has been made to solve the above problem, and an object of the present application is to provide a method for manufacturing a vacuum valve so that the manufacturing cost is low.

the solution of the problem

A method of manufacturing a vacuum valve disclosed in the present application is a method of manufacturing a vacuum valve, whereby a vacuum chamber is formed by connecting a fixed-side end plate and a moving-side end plate by brazing each to respective ends of a cylindrical insulating chamber, together with which an intermediate assembly of a vacuum valve formed by accommodating a fixed-side electrode and a moving-side electrode within the vacuum chamber is arranged in a mold, and whereby an insulating resin layer is formed by molding an insulating resin material in an outer periphery of the intermediate assembly, wherein a region of an outer edge portion of the fixed-side end plate is formed in such a manner that a stress generated in a brazed portion between the insulating chamber and the fixed-side end plate when the insulating resin material is molded in the outer periphery of the intermediate assembly is smaller than an allowable stress of the brazed portion.

Advantageous effects of the invention

According to the method for manufacturing a vacuum valve disclosed in the present application, a stress applied to a brazed portion of a vacuum valve due to a molding pressure when an insulating resin is molded can be reduced, and an inexpensive vacuum valve whose manufacturing cycle is short can be manufactured.

Short description of the drawings

• [ 1 ] 1 is a sectional view showing a configuration of an entire vacuum valve manufactured using a method of manufacturing a vacuum valve according to a first embodiment.
• [ 2 ] 2 represents a sectional view showing an A-section of the 1 enlarged.
• [ 3A ] 3A is a schematic view for describing the method of manufacturing a vacuum valve according to the first embodiment.
• [ 3B ] 3B is a schematic view for describing the method of manufacturing a vacuum valve according to the first embodiment.
• [ 3C ] 3C represents a schematic view for describing the process for Manufacture of a vacuum valve according to the first embodiment.
• [ 4 ] 4 is a schematic view and a characteristic diagram for describing a relationship between a stress when a vacuum valve is molded according to the first embodiment and an area of an outer peripheral portion.
• [ 5 ] 5 is a sectional view showing a configuration of an entire vacuum valve manufactured using a method of manufacturing a vacuum valve according to a second embodiment.
• [ 6 ] 6 represents a sectional view showing a B-section of the 5 enlarged.
• [ 7 ] 7 represents a perspective view of a major section of the 6 represents.
• [ 8A ] 8A is a sectional view showing a manufacturing process relating to a method of manufacturing a vacuum valve according to a third embodiment.
• [ 8B ] 8B represents a perspective view showing a portion of the manufacturing process of the 8A in cross section.
• [ 9 ] 9 is a sectional view showing an example of another manufacturing process concerning the method of manufacturing a vacuum valve according to the third embodiment.
• [ 10 ] 10 is a sectional view showing an example of another manufacturing process concerning the method of manufacturing a vacuum valve according to the third embodiment.
• [ 11 ] 11 is a sectional view showing an example of another manufacturing process concerning the method of manufacturing a vacuum valve according to the third embodiment.
• [ 12A ] 12A is a schematic view for describing a method of manufacturing a vacuum valve according to a fourth embodiment.
• [ 12B ] 12B is a schematic view for describing the method of manufacturing a vacuum valve according to the fourth embodiment.
• [ 12C ] 12C is a schematic view for describing the method of manufacturing a vacuum valve according to the fourth embodiment.
• [ 13 ] 13 is a timing chart showing a change in a stress generated in a main portion in a case of the methods of manufacturing a vacuum valve according to the third embodiment and the fourth embodiment.

Description of the embodiments

First embodiment

Hereinafter, a method of manufacturing a vacuum valve according to the present application will be described using the drawings. In the drawings, identical reference numerals are assigned to identical or corresponding parts.

1 is a sectional view showing a configuration of an entire vacuum valve manufactured using a method of manufacturing a vacuum valve according to a first embodiment, and 2 represents a sectional view showing an A-section of the 1 enlarged.

In 1 a vacuum valve 100 is arranged to include a cylindrical insulating chamber 1 formed of ceramics or the like, a fixed-side end plate 2 and a moving-side end plate 3 connected by brazing to each end of the insulating chamber 1, a fixed-side electrode rod 4 fixed to the fixed-side end plate 2, a fixed-side electrode 5 fixed to an end portion of the fixed-side electrode rod 4 and arranged inside the insulating chamber 1, a moving-side electrode rod 7 supported by the moving-side end plate 3 via a bellows 6 so as to be able to slide, a moving-side electrode 8 connected to an end portion of the moving-side electrode rod 7 and arranged inside the insulating chamber 1, and in an outer periphery an insulating resin layer 9 formed by molding an insulating resin material using a BMC (bulk cast composition: unsaturated polyester) material as main element.

The insulating chamber 1 forms a vacuum chamber which is hermetically sealed by being connected to the fixed-side end plate 2 and the moving-side end plate 3 by brazing, and a brazed portion 10 which is normally a thin metal foil in a µm order is formed in a connecting portion as shown in 2 Also, the fixed-side electrode 5 and the moving-side electrode 8 are arranged opposite each other in a axial direction in an interior of the insulating chamber 1 and are arranged such that contact with the fixed-side electrode 5 can be made or broken in accompaniment to a movement of the moving-side electrode 8.

A process for forming the insulating resin layer 9 in this type of vacuum valve 100 using direct molding is described using the 3A , the 3B and the 3C to be discribed.

First, a vacuum chamber is formed by brazing the fixed-side end plate 2 and the moving-side end plate 3 to each end of the cylindrical insulating chamber 1, as shown in 3A , together with which an intermediate assembly of a vacuum valve formed by accommodating the fixed-side electrode 5 and the moving-side electrode 8 within the vacuum chamber is assembled, a core 11 is attached to the intermediate assembly and arranged in a fixed-side molding die 12, and an insulating resin material 13 having a BMC material as a main element is arranged in a semi-cured state at an upper portion of the insulating chamber 1 in the intermediate assembly.

As in 3B Next, as shown, a moving-side mold 14 is moved, and the insulating resin material 13 is pressed and thereby caused to flow.

Finally, with the moving-side mold 14 moved to a final position, an outer periphery of the intermediate assembly is filled with the insulating resin material 13 as shown in 3C that the vacuum valve 100 with the insulating resin layer 9 formed in the outer periphery can be manufactured by curing the insulating resin material 13.

When the outer periphery of the assembly is filled with the insulating resin material 13, the BMC material requires a high molding pressure (about 10 megapascals), but if the molding pressure P is too large, there is a concern that the brazed portion 10 of the vacuum valve 100 will be damaged, so a relationship between a stress F1 generated in the brazed portion 10 and an allowable stress F2 of the brazed portion 10 must be set to F1 < F2.

Here, because the load F1 caused by the molding pressure P is proportional to an area S of an outer peripheral portion of the fixed-side end plate 2 and the moving-side end plate 3, the fixed-side end plate 2 and the moving-side end plate 3 are arranged such that the area S is such that a ratio between a load F caused by the molding pressure P and the area S is F1 < F2, as shown in 4 whereby damage to the brazed portion 10 can be prevented, and the vacuum valve 100 can be manufactured with the outer peripheral portion formed using direct molding.

Second embodiment

5 is a sectional view showing a configuration of an entire vacuum valve manufactured using a method for manufacturing a vacuum valve according to a second embodiment, wherein 6 is a sectional view showing a B-section of the 5 enlarged, and where 7 a perspective view of a main section of the 6 represents.

In the second embodiment, a cover 15 formed of a cup-shaped conductive member inserted into 7 is arranged so that the fixed-side end plate 2 is covered, and the insulating resin layer 9 is formed by molding the entire intermediate assembly using the insulating resin material 13. Since the other configurations are the same as in the first embodiment, identical reference numerals are assigned to corresponding parts and description is omitted.

By disposing the cover 15 formed of a cup-shaped conductive member and molding the insulating resin material 13 in this manner, a stress applied to the brazed portion 10 and generated in molding can be reduced, and a degree of freedom in the configuration of the vacuum valve 100 can be increased.

Also, because the cover 15 formed of a cup-shaped conductive member reduces a concentration of an electric field in the brazed portion 10, a dielectric strength of the vacuum valve 100 can be further increased.

Third embodiment

8A is a sectional view showing a manufacturing process relating to a method of manufacturing a vacuum valve according to a third embodiment, and 8B presents is a perspective view showing a portion of the manufacturing process of the 8A in a cross section.

The vacuum valve 100 is such that it is necessary to secure a space on the movable side in which the moving-side electrode rod 7 can move, and therefore molding an entire outer periphery of the moving-side end plate 3 is not feasible. Therefore, a projected area over which the intermediate assembly is molded in the axial direction of the vacuum valve is such that that on the movable side is smaller than that on the fixed side, and a stress generated in the intermediate assembly when it is molded is such that that on the fixed side is larger than that on the movable side.

This means that when an axially directed pressure is received during molding through an external discharge port 4a coupled to the fixed-side end plate 2 and the fixed-side electrode rod 4, a total load is received by the fixed-side end plate 2 and there arises a concern that distortion will occur. Therefore, the insulating chamber 1 is supported from a circumferential direction by the core 11 of the molds 12 and 14, and filling with the insulating resin material 13 is carried out in this state, as shown in FIG. 8A and 8B wherein the axially directed stress generated in the fixed-side end plate 2 can be reduced, and damage to the brazed portion 10 caused by molding can be prevented.

9 , 10 and 11 are sectional views showing an example of another manufacturing process relating to the method for manufacturing a vacuum valve according to the third embodiment, wherein 9 shows an example in which the insulating chamber 1 is supported from the axial direction by a front end of the core 11. Also 10 shows an example where the movement-side end plate 3 is supported from the circumferential direction, and further shows 11 an example wherein the moving-side end plate 3 is supported from the axial direction, and in both cases, the axially directed load generated in the fixed-side end plate 2 can be reduced.

Fourth embodiment

12A , 12B and 12C are schematic views for describing a method of manufacturing a vacuum valve according to a fourth embodiment, and show a manufacturing process in a case of using transfer molding. 13 also illustrates a timing chart showing a change in a stress generated in a main portion in a case of the method of manufacturing a vacuum valve according to the fourth embodiment.

First, in a state where a core 20 is attached in a manner that a circumferential direction of the moving side end plate 3 is supported in the intermediate arrangement of a vacuum valve, as shown in 12A As shown, the core 20 is arranged between a preheated fixed-side mold 21 and a moving-side mold 22, and an insulating resin material 30 having a preheated BMC material as a main element is placed in a material filling pot 23 of the moving-side mold 22.

Next, as in 12B shown, the insulating resin material 30 is injected into the molds 21 and 22 by moving a pressurizing device 24, and finally, as shown in 12C As shown, outer peripheries of the intermediate assembly and the core 20 are filled with the insulating resin material 30 by causing the pressurizing device 24 to move to a final position.

Thereafter, the vacuum valve 100 can be manufactured, wherein the insulating resin layer 9 is formed in the outer periphery of the intermediate assembly of the vacuum valve by curing the insulating resin material 30.

This type of transfer molding is such that when the preheated insulating resin material 30 flows inside the molds 21 and 22, because the molds 21 and 22 are preheated, the insulating resin material 30 is further heated and changes into a gel form and a viscosity of the insulating resin material 30 decreases. This means that, as shown in 13 As shown, a pressure applied to the vacuum valve intermediate assembly while it is filled with the insulating resin material 30 decreases, and a stress F4 generated in the brazed portion 10 can be caused to decrease.

Since molding conditions such as a position or an injection speed of the insulating resin material 30 filling the mold are determined by controlling a mold structure and a molding device, the molding condition control is also easy, and a change in the stress F4 generated in the brazed portion can be restricted.

Consequently, the vacuum valve 100 can be manufactured with a more stable quality.

Direct compression molding is such that an operator performs placement of an insulating resin material, and a deviation may occur in operation, and in particular, a deviation in a location and a timing of a pressure applied to the intermediate assembly may be significant depending on a displacement of the insulating resin material 30 in a semi-cured state as indicated by a stress F3 generated in the brazed portion 10 in the first embodiment in 13 is generated, and there is a concern that a change will increase accompanied by the fact that the stress F3 generated in the brazed portion 10 also increases, but according to the transfer molding, there is an advantage that molding condition control is easy.

Although a configuration in the fourth embodiment is such that the insulating resin layer 9 is formed using a transfer molding method, a configuration may also be adopted wherein the insulating resin layer 9 is formed using an injection molding method.

Furthermore, in the embodiments described hereinbefore, a configuration is such that an insulating resin layer is formed using an insulating resin material having an unsaturated polyester resin as a main element of an insulating resin material, but a phenol resin, a vinyl ester resin, or an acrylic resin may also be used as a main element.

Also, an insulating resin layer may be formed of an insulating resin material including a main element of 20 to 30% of a glass fiber, a carbon fiber, an aramid fiber, a polyethylene fiber, a zylon fiber or a boron fiber as a reinforcing fiber of 15 to 20% and a calcium carbonate, aluminum hydroxide or a silicate as a filler of 50 to 60%.

Although the present application is described above in terms of various exemplary embodiments and implementations, it should be understood that various features, aspects, and functionality described in one or more of the individual embodiments are not limited in applicability to the particular embodiment in which they are described, but instead may be applied alone or in various combinations to one or more of the embodiments.

It is therefore to be understood that numerous modifications not exemplified may be devised without departing from the scope of the present application. For example, at least one of the constituent components could be modified, added, or omitted. At least one of the constituent components mentioned in at least one of the preferred embodiments could be selected and combined with the constituent components mentioned in another preferred embodiment.

List of reference symbols

1

Isolation chamber

2

fixed end plate

3

movement-side end plate

4

fixed-side electrode rod

5

fixed-side electrode

6

Bellows

7

movement-side electrode rod

8th

movement-side electrode

9

insulating resin layer

10

brazed section

11

core

12

fixed-side forming tool

13

insulating resin material

14

movement-side forming tool

15

cover

20

core

21

fixed-side mold

22

movement-side mold

23

Material filling pot

24

Pressurization device

30

insulating resin material

100

Vacuum valve

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• JP 2013093276 A [0003]

Claims (6)

A method of manufacturing a vacuum valve, whereby a vacuum chamber is formed by connecting a fixed-side end plate and a moving-side end plate by brazing each to a respective end of a cylindrical insulating chamber, together with which an intermediate assembly of a vacuum valve formed by accommodating a fixed-side electrode and a moving-side electrode within the vacuum chamber is arranged in a mold, and whereby an insulating resin layer is formed by molding an insulating resin material in an outer periphery of the intermediate assembly, wherein a region of an outer edge portion of the fixed-side end plate is formed such that a stress generated in a brazed portion between the insulating chamber and the fixed-side end plate when the insulating resin material is molded in the outer periphery of the intermediate assembly is smaller than an allowable stress of the brazed portion. Method for producing a vacuum valve according to Claim 1 , wherein direct compression molding, transfer molding or injection molding is used as the molding method for forming the insulating resin layer. Method for producing a vacuum valve according to Claim 1 or 2 wherein the insulating resin layer is formed by filling the outer periphery of the intermediate assembly with the insulating resin material in a state where a portion of the moving-side end plate side of the insulating chamber or the moving-side end plate is supported by a core. Method for producing a vacuum valve according to one of the Claims 1 until 3 wherein an insulating resin having one of an unsaturated polyester resin, a vinyl ester resin, a phenol resin or an acrylic resin as a main element is used as the insulating resin material. Method for producing a vacuum valve according to one of the Claims 1 until 4 wherein the intermediate assembly is formed by further providing a cover covering the outer edge portion of the fixed-side end plate. Method for producing a vacuum valve according to Claim 5 , wherein the cover is formed by a conductive member.