JPS6160530B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a vacuum valve, and particularly to improvements in an insulating container and an end plate. Generally, a vacuum valve consists of an insulating container and a pair of electrodes that can be freely connected to and separated from the vacuum container, which has an internal pressure of 10 ^-4 Torr or less and is constructed by closing both ends of the container with end plates. A fixed shaft is attached to one of the electrodes, and the electrode passes through one end plate in an airtight manner and is led out to form an electric path. A movable shaft serving as an electric path is attached to the other electrode, and a bellows is attached to the movable shaft to enable the electrode to be opened and closed in a vacuum-maintained state attached to the other end plate. Further, an arc shield is arranged around the electrode. As methods for attaching these parts, there are methods such as brazing using metal wax and arc welding. This internal brazing method is often used. This method is a method in which metal wax is placed in advance near the parts to be joined together, and the parts are joined together by heating to high temperature in a non-oxidizing atmosphere furnace to melt the wax material. As the non-oxidizing atmosphere furnace, a vacuum furnace or a hydrogen furnace is generally used. By the way, general vacuum valves use an exhaust pipe installed in the vacuum valve to create a high vacuum inside the vacuum valve, exhaust the internal gas with a vacuum pump, and after obtaining a predetermined high vacuum, the exhaust pipe is crimped. The vacuum valve was completed by sealing it off using this method. However, there was a drawback that the tip of the exhaust pipe sealing part was easily damaged. In order to eliminate this drawback, a vacuum valve without an exhaust pipe has been proposed, and this manufacturing method involves partially assembling it in a hydrogen furnace or in a vacuum furnace, and then soldering it in a vacuum. This is a method of vacuum sealing. By the way, the vacuum sealing method using vacuum brazing involves placing metal wax between the insulating container and the end plates at both ends, and partially assembling the container in a high vacuum at a pressure of 10 ^-4 Torr or less in a vacuum furnace. Vacuum sealing is performed by heating at a temperature within a range that does not melt the metal wax used in the process and waxing in vacuum. The metal wax used is a plate or a linear one, but if the insulating container, the metal wax, and the end plate are in direct contact with each other before the wax material melts, the internal gas inside the container cannot be exhausted. Therefore, the shape of metal wax is generally shaped into a wave shape, etc.
A gap is created between the inside and outside of the container so that the internal gas can be exhausted. After the exhaust is completed, the metal wax is melted and vacuum sealed, completing the vacuum valve. By the way, the above-mentioned conventional method of making metal wax into a corrugated shape or the like to create a gap to exhaust internal gas and vacuum sealing has the following drawbacks. In other words, because the gap _δ1 between the insulating container and the end plate is large, when the metal wax melts and the insulating container and end plate contact and seal, the end plate does not contact and adhere to the predetermined position on the end surface of the insulating container. As a result, the center of the end plate and the insulating container were misaligned, and as a result, the electrodes were also misaligned, creating a problem in maintaining the quality of the vacuum valve. In addition, metal wax is generally expensive, and it takes time and effort to form thin metal wax into a corrugated shape.
It became increasingly expensive and became an economic problem. The present invention has been made to eliminate the above-mentioned problems, and its purpose is to make it possible to exhaust the internal gas during brazing in a vacuum without depending on the waveform shape of the metal wax, thereby achieving economical and excellent quality. Our objective is to provide a vacuum valve with DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, details of the present invention will be described with reference to an embodiment shown in the drawings. FIG. 1 shows a vacuum valve. 1 is a vacuum valve, and an insulating container 2 made of alumina porcelain
A pair of electrodes 4a, which can be freely connected and separated, is placed in a vacuum container with an internal pressure of 10 ^-4 Torr or less, which is constructed by closing both ends with end plates 3a and 3b made of an alloy whose coefficient of thermal expansion is similar to that of alumina porcelain. 4b. A stationary electric shaft 5a is attached to one electrode 4a and is led out through one end plate 3a in an airtight manner to form an electric path. A movable current-carrying shaft 5b serving as an electric path is attached to the other electrode 4b, and is attached to the end plate 3b via a bellows 7, making it possible to open and close the electrodes 4a and 4b in a vacuum-maintained state. The arc shield 6 is arranged around the electrodes 4a, 4b to prevent the inside of the insulating container 2 from being contaminated by metal vapor generated from the electrodes 4a, 4b when current is switched on and off. 2 and 3 show embodiments of the present invention, in which FIG. 2 shows an end plate 3a, and FIG. 3 shows an insulating container 2 with a gap for exhausting internal gas. Second
In the figure, a plate-shaped or linear metal wax 8a (not shown) is placed on the end face of the insulating container 2, and end plates 3a are placed so as to sandwich the metal wax 8a. A groove having a depth α ₁ and a width β ₁ is machined in the front of the end plate 3a.
As shown in Table 1 of the test results, _α1 was 0.5 mm or less and _β1 was 0.1 to 5 mm, making it possible to exhaust internal gas and perform brazing. Brazing involves melting only the metal wax 8a and blending it into the base material, filling the gaps using capillary action.

This method achieves the purpose of joining by filling the [Table] with metal wax, and it has been found that the gap does not adversely affect the brazing characteristics. FIG. 3 shows an embodiment in which grooves similar to those described above are provided on the end face of the insulating container 2. A groove having a depth α ₁ and a width β ₁ is formed in the insulating container 2, and a metallized layer coated with Mo-Mn or the like is formed thereon to enable metal brazing. α ₁ is 0.5 mm or less β ₁ is a gap of 0.1 to 5 mm. As explained above, the present invention is a vacuum valve that vacuum-seals an insulating container and its end plates at both ends with metal wax in a high vacuum at a pressure of 10 ^-4 Torr or less, and exhausts internal gas inside the container to the outside. By creating a groove in the end plate or insulating container without creating a gap in the metal wax, it is possible to prevent misalignment between the insulating container and the end plate, and to eliminate misalignment of the internal electrodes, thereby improving quality. Therefore, it is possible to provide a vacuum valve that can maintain the following conditions and improve reliability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a vacuum valve showing one embodiment of the present invention, FIG. 2a is an enlarged front view of a portion of FIG. 1, FIG. 2b is a plan view, and FIG. The front view shown in FIG. 3b is a plan view. 1... Vacuum valve, 2... Insulating container, 3a, 3
b... End plate, 4a, 4b... Electrode, 5a, 5b...
...Electrifying shaft, 6... Arc shield, 7... Bellows, 8a, 8b... Metal wax.

Claims (1)

[Claims] 1 A vacuum container has a pair of separable electrodes inside the vacuum container, and the insulating container and the end plates at both ends are connected under pressure.
For vacuum valves that are vacuum-sealed with metal wax in a high vacuum of 10 ^-4 Torr or less, grooves with a depth of 0.5 mm or less and a width of 0.1 to 5.0 mm are provided on the insulating container or end plate. Features a vacuum valve.