JP6018366B2 - Manufacturing method of vacuum valve - Google Patents

Description

Embodiments described herein relate generally to a method of manufacturing a vacuum valve having a pair of contact points that can be separated from each other.

  Conventionally, in a contact using a Cu—Cr alloy, Cr particles as arc-resistant components are refined to improve withstand voltage characteristics. As this means, it is known to irradiate energy to the contact surface before assembling the vacuum valve with an electron beam (for example, refer to Patent Document 1). In addition, it is known to perform a current conditioning process for discharging between contacts after assembling the vacuum valve (see, for example, Patent Document 2).

  However, at the contact subjected to energy irradiation, the particle diameter of the arc-resistant component may increase due to heat input during the assembly of the vacuum valve. Further, at the time of assembling, although the contact time is short, the contact is exposed to the atmosphere, oxidation occurs, and it is difficult to improve the withstand voltage characteristics.

  On the other hand, in the current conditioning process, although a predetermined number of discharges of several tens to several hundreds are generally performed, it is difficult to process the entire contact area, and there is a limit in improving the withstand voltage characteristics.

JP-A-8-111131 JP 2010-123347 A

The problem to be solved by the present invention is that of a vacuum valve capable of improving withstand voltage characteristics by adding miniaturization by current conditioning treatment while maintaining miniaturization of arc resistance component by energy irradiation before vacuum valve assembly . It is to provide a manufacturing method .

In order to solve the above problems, a manufacturing method of the vacuum valve of the embodiment is a method of manufacturing a vacuum interrupter having a pair of contacts of the universal separable, predetermined amounts mixing the conductive component and arc-proof component the contact First, a first fine layer in which the arc-resistant component is refined by providing energy irradiation over the entire contact surface is provided, and after cooling, this is incorporated into a vacuum valve, and the first fine layer is provided. The surface is subjected to a current conditioning process, and a second fine layer is randomly provided in which the arc-proof component has a grain size equal to or less than that of the first fine layer .

Sectional drawing which shows the structure of the vacuum valve which concerns on the Example of this invention. The figure which shows the manufacturing method of the vacuum valve which concerns on the Example of this invention. Explanatory drawing which cuts and shows immediately after manufacture of the contact of the vacuum valve which concerns on the Example of this invention. Explanatory drawing which shows in cross section the time of energy irradiation of the contact of the vacuum valve which concerns on the Example of this invention. Explanatory drawing which shows the cross section at the time of the current conditioning process of the contact of the vacuum valve which concerns on the Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  A vacuum valve according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a configuration of a vacuum valve according to an embodiment of the present invention, FIG. 2 is a diagram showing a manufacturing method of a vacuum valve according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is an explanatory view showing a cross section immediately after the manufacture of the contact of the vacuum valve, FIG. 4 is an explanatory view showing the energy irradiation of the contact of the vacuum valve according to the embodiment of the present invention, and FIG. It is explanatory drawing which carries out the cross section at the time of the electric current conditioning process of the contact of the vacuum valve which concerns on an Example.

  As shown in FIG. 1, a fixed-side sealing metal fitting 2 and a movable-side sealing metal fitting 3 are sealed at both end openings of a cylindrical vacuum insulating container 1 made of alumina porcelain. The fixed-side sealing metal fitting 2 has a fixed-side energizing shaft 4 penetrating and fixed at the center, and a fixed-side contact 5 is fixed to an end of the vacuum insulating container 1. Opposite to the fixed side contact 5, a movable side contact 6 that is detachable is fixed to the end of the movable side energizing shaft 7 that movably penetrates the movable side sealing fitting 3. One end of a telescopic bellows 8 is sealed at the intermediate portion of the movable side energizing shaft 7, and the other end is sealed at the central opening of the movable side sealing fitting 3. Thereby, the movable side energizing shaft 7 can be moved in the axial direction while maintaining the vacuum in the vacuum insulating container 1. A cylindrical arc shield 9 is provided around the contacts 5 and 6.

  Here, the contacts 5 and 6 are made of a Cu—Cr alloy, and the base layers 5a and 6a of this alloy and the first particles obtained by refining Cr particles provided by energy irradiation over the entire surface to be contact and separation surfaces. It is composed of fine layers 5b and 6b and second fine layers 5c and 6c obtained by miniaturizing Cr particles randomly provided by current conditioning.

  Next, a manufacturing method using the fixed contact 5 will be described with reference to FIGS. The same applies to the movable contact 6.

As shown in FIG. 2, a base layer 5a having a predetermined shape is manufactured from a sintered body of a Cu—Cr alloy mixed with a predetermined amount (st1). As shown in FIG. 3, in the base material layer 5a, Cr particles 5a2 having a particle size of several tens of μm are mixed in a Cu matrix 5a1. First, the surface of the base material layer 5a is irradiated with energy of 1 W / mm ² by, for example, an electron beam to melt the depth of 20 to 30 μm (st2) and cool (st3). By melting and cooling, the first fine layer 5b is formed as shown in FIG. First to several μm of first fine Cr particles 5b1 are formed.

  Next, the contact 5 having the first fine layer 5b is incorporated into a vacuum valve by brazing work or the like (st4). In this case, it may be exposed to the atmosphere during transportation. After assembly, the contacts 5 are opened at a predetermined interval, and a current conditioning process is performed to discharge a predetermined number of times from several tens to several hundreds using a small current of several A (st5). Then, as shown in FIG. 5, the second fine layer 5c having the second fine Cr particles 5c1 is randomly formed on the surface of the first fine layer 5b. Depending on the discharge conditions, the second fine layer 5c may reach the base material layer 5a.

  Even if the second fine Cr particles 5c1 grow due to heat input at the time of assembling the vacuum valve and the Cr particle size increases, they are refined by the current conditioning process. Further, even if impurities such as an oxide adhere to the surface of the first fine layer 5b, they are removed. If the temperature of the first fine layer 5b immediately after melting and cooling is higher than the ambient temperature (normal temperature), an increase in the particle size of the fine Cr particles 5b1 is suppressed.

  In the current conditioning process, the place where the second fine layer 5c is formed cannot be controlled. However, the withstand voltage characteristics can be improved because the first fine layer 5b is formed even in the portion where the second fine layer 5c is not formed. The particle diameter of the second fine Cr particles 5c1 is equal to or less than that of the first fine Cr particles 5b1.

  In the case where a sintered body is manufactured with a Cu65 (wt%)-Cr35 (wt%) alloy, energy irradiation is performed on the breakdown voltage obtained only by the base material layer 5a, and the first fine layer 5b is provided. There was a 30% improvement. In the case where this was incorporated in a vacuum valve and subjected to the current conditioning process 50 times to provide the second fine layer 5c, an improvement of about 25% was observed. The breakdown voltage is a stable value after 30 times of application.

  According to the vacuum valve of the above embodiment, energy is irradiated on the entire contact / separation surface during the manufacture of the contacts 5 and 6, the Cr particles 5a2 are made finer, and after the vacuum valve is assembled, the current conditioning process is performed to obtain the Cr particles 5a2. Therefore, the withstand voltage characteristics can be greatly improved.

  In the said Example, although demonstrated using Cr for an arc-proof component, at least 1 or more types can be used among the carbide | carbonized_materials of W, Nb, Ta, Ti, and Mo. For this reason, when the arc resistance component is summarized, the carbide after the energy irradiation including the first fine Cr particles 5b1 is the carbide after the current conditioning treatment including the first fine arc resistance component and the second fine Cr particles 5c1. Can be referred to as a second fine arc resistant component. Further, as an auxiliary component, at least one of Bi, Te, Se, Sb, and Co can be contained in an amount of 5 (wt%) or less. Furthermore, although Cu was used for the conductive component, Ag can be used.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Vacuum insulating container 2 Fixed side sealing metal fitting 3 Movable side sealing metal fitting 4 Fixed side electricity supply axis | shaft 5 Fixed side contact 5a, 6a Base material layer 5a1 Cu matrix 5a2 Cr particle 5b, 6b 1st fine layer 5b1 1st fine layer Cr particle 5c, 6c Second fine layer 5c1 Second fine Cr particle 6 Movable side contact 7 Movable side energizing shaft 8 Bellows 9 Arc shield

Claims (1)

A method for manufacturing a vacuum valve having a pair of contactable and separable contacts,
The contact is produced by mixing a predetermined amount of a conductive component and an arc resistant component,
First, a first fine layer in which the arc-resistant component is refined by performing energy irradiation over the entire contact surface is provided,
After cooling this, it is built into the vacuum valve,
Then, a current conditioning process is performed on the surface of the first fine layer,
A method of manufacturing a vacuum valve , wherein a second fine layer having a particle size of the arc-resistant component equal to or less than that of the first fine layer is randomly provided .

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