KR19980087242A - Manufacturing Method of Base Material of Vacuum Valve - Google Patents

Abstract

TECHNICAL FIELD This invention relates to the manufacturing method of the base material of a vacuum valve. Specifically, It is related with the manufacturing method of the base material of a vacuum valve which is hard to melt by the arc at the time of shutoff.

For this reason, in the manufacturing method of the base material of this invention, an electrode green compact which pressed the base material into the mixed powder by the highly conductive metal powder and the high melting point metal powder, and the high melting point metal powder, and the high melting point metal powder is smaller than a high level. A diffusion member obtained by powdering a mixed powder made of a malleable metal powder and a support member made of a highly conductive metal are laminated and heated in a heating furnace to disperse the electrode containing the electrode powder and the high melting point metal. In forming a vacuum valve base material consisting of.

Description

Manufacturing Method of Base Material of Vacuum Valve

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a base material of a vacuum valve, and more particularly, to a method of manufacturing a base material of a vacuum valve, in which the life of an electrode that is difficult to melt due to an arc at the time of shutoff is extended.

Vacuum circuit breaker is used together with disconnector, grounding switch, lightning arrester and current transformer. It is a device used as a substation facility.

In the vacuum valve provided in the vacuum circuit breaker, a pair of fixed electrodes and movable electrodes are disposed correspondingly, and a support member connected to the back of both electrodes extends to the outside, and these electrodes and the support member are formed of a conductive base material. The positive electrode is composed of a high melting point member.

The high melting point member is directly exposed to the arc to open and close high voltage and high current. Characteristics required for high melting point members include high breaking capacity, high breakdown voltage, low contact resistance (excellent electrical conductivity), excellent welding resistance, low contact consumption, and cutting current value. Basic elements, such as a small dot.

However, it is difficult to satisfy all of these characteristics, and in general, a material that is particularly important depending on the application is considered, and a material that sacrifices other characteristics to some extent is used. As a contact material for high current and high voltage interruption, Japanese Unexamined Patent Publication No. 63-96204 discloses a method of infiltrating Cu in Cr or Cr-Cu skeleton. Moreover, the same manufacturing method is also disclosed by Unexamined-Japanese-Patent No. 50-21670.

The manufacturing method of the high melting point member is sintering Cr powder, Cu powder, W powder, Co powder, Mo powder, V powder, Nb powder, or a mixed powder thereof in a predetermined composition, shape, and porosity. After that, the contact member manufactured by the so-called infiltration method for injecting Cu or its alloy molten metal into the skeleton of the sintered body or the so-called powder metallurgy method with a density of 100% in the sintering process before infiltration is machined again to a predetermined shape. do. The support members are cut out from the pure Cu material into predetermined shapes.

In this way, a soldering member is soldered to the back of the machined electrode after infiltration to form a series of electrode structures. However, in the soldering method, a solder material having good wettability is inserted between each of the high melting point member and the support member, and the solder is bonded by heating in a vacuum or in a reducing atmosphere. However, the electrode composed of the solder joint is used to machine each member. It takes a lot of trouble and time to assemble for over soldering, and also causes an accident of destruction or dropping of electrode material due to poor soldering.

Thus, as a method of integrating the above-mentioned high melting point member and the supporting member in the manufacturing process, the supporting member is formed on the skeleton formed by mixing the mixed powder composed of the components of the high melting point member into a predetermined composition, shape, and porosity. The so-called integral immersion method has been developed in which a highly conductive metal is placed, the temperature is raised to infiltrate the highly conductive metal into the high melting point member, and a support member is formed with the rest of the highly conductive metal. This manufacturing method is disclosed in Japanese Patent Laid-Open No. 7-29461.

The integrated immersion method eliminates the need for machining and soldering parts for each member, which greatly improves productivity, and does not destroy or drop electrodes due to poor soldering, and provides excellent reliability and safety. You can get it. Further, during infiltration, a part of the components constituting the high melting point member is melted by high temperature heating for dissolving the highly conductive metal constituting the support member, and diffused and dissolved in the molten highly conductive metal. This has the advantage that the strength of the supporting member is improved.

However, on the other hand, the high melting point member of the obtained electrode becomes eroded toward the support member by diffusion and solid solution, and there is a problem that the desired thickness and shape can not be obtained as the high melting point member. As a countermeasure, the thickness of the high melting point member and the shape of the high melting point member are secured by preliminarily producing the skeleton of the high melting point member by the amount of reduction in advance by predicting the amount of reduction of the high melting point member toward the support member and by the solid solution. Doing.

According to this countermeasure, the raw materials corresponding to the high melting point members are required as much as the decrease due to diffusion and solid solution, and the manufacturing cost increases. In addition, since the amount of reduction of the high melting point member changes considerably due to the irregularity of the composition and the amount of voids in the skeleton, as shown in FIG. 5 as the prior art, Cr as a high melting point metal and Cu as a highly conductive metal are shown. In the case of using, the interface position with the high melting point member becomes irregular, not only the production yield is lowered, but also a large amount of Cu agglomerates on the electrode contact surface, which is easily melted by the arc at the time of interruption, and the life as an electrode is short. .

An object of the present invention is to provide a method for producing a base material of a vacuum valve, which prolongs the life of an electrode that is difficult to melt due to an arc at the time of interruption.

In this invention, in order to achieve the said objective, this invention is a manufacturing method of the base material of the vacuum valve which consists of at least one pair of electrode arrange | positioned in a vacuum valve, and the support member extended from an electrode, The base material is a highly conductive metal powder Electrode powder compacted with a powder mixed with a high melting point metal powder, and a diffusion powder compact with a high melting point metal powder and a powder mixed with a smaller amount of highly conductive metal powder than the high melting point metal powder. And a vacuum valve base material comprising a support member made of a highly conductive metal laminated in a heating furnace and heated to form an electrode containing a green compact for the electrode and a support member in which a high melting point metal is dispersed.

Moreover, in order to achieve the said objective, in the manufacturing method of the base material of the vacuum valve of this invention, after heating the green compact for electrodes, the green compact for diffusion, and a support member, the component of a spreading green compact is a pressure of the said electrode for pressure. Diffusion is carried out in powder and a support member, and the spreading green compact disappears.

Moreover, in order to achieve the said objective, the manufacturing method of the base material of the vacuum valve of this invention arrange | positions an electrode green compact, a spreading green compact, and a support member in a heating furnace, and heats it in a vacuum state after that. have.

Moreover, in order to achieve the said objective, in the manufacturing method of the base material of the vacuum valve of this invention, after making the inside of a heating furnace into a vacuum state, the electrode green compact, the spreading green compact, and a support member are arrange | positioned in a heating furnace, It is in heating.

In addition, in order to achieve the above object, in the method of manufacturing the base material of the vacuum valve of the present invention, the base material is mixed with 65 to 35 weight (%) of high melting point metal powder and 35 to 65 weight (%) of highly conductive metal powder. An electrode green compact obtained by compacting a mixed powder, a diffusion green compact obtained by compacting a mixed powder obtained by mixing 97 to 80 weight% of high melting point metal powder and 3 to 20 weight% of highly conductive metal powder. It is in use.

In addition, in order to achieve the above object, the manufacturing method of the base material of the vacuum valve of the present invention, the conductive base material is a mixed powder of 65 to 35 weight (%) Cr powder and 35 to 65 weight (%) Cu powder mixed The present invention is to use a diffusion green compact obtained by compacting a compacted electrode green compact and a mixed powder obtained by mixing 97 to 80 weight% of Cr powder and 3 to 20 weight% of Cu powder.

In addition, in order to achieve the above object, the manufacturing method of the base material of the vacuum valve of the present invention, the electrode green compact and the diffusion green compact is a high melting point metal, Cr, W, Mo, Ta, Nb, Be, Hf, Ir , Pt, Zr, Ti, Te, Si, Rh and Ru, or a mixture of one or two or more thereof, and a highly conductive metal made of Cu, Ag, or Au, or an alloy of a highly conductive metal mainly containing them. The support member is to use a highly conductive metal or an alloy containing a highly conductive metal.

In addition, in order to achieve the above object, the manufacturing method of the base material of the vacuum valve of the present invention, the green compact for the electrode is a high melting point metal, Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, It consists of a composite metal containing 35 to 65% by weight of a total of one or two or more of Ti, Te, Si, Rh and Ru and 35 to 65% by weight of Cu as a highly conductive metal, and the diffusion green compact is a high melting point metal. It consists of a composite metal containing one or two or more of the total amount of Cr, W, Mo and Ta of 80 to 97% by weight and 3 to 20% by weight of Cu as a highly conductive metal, the support member is Cr, Ag, W, One or two or more total amounts of V, Nb, Mo, Ta, Zr, Si, Be, Co, and Fe are used to use an alloy of 4 wt% or less with Cu, Ag, or Au.

Moreover, in order to achieve the said objective, in the manufacturing method of the base material of the vacuum valve of this invention, when the 0.2% yield strength of the base material produced by this manufacturing method is 10 kg / mm <2> or more, the specific resistance is 2.8 microohm cm or less.

According to the manufacturing method of the base material of the vacuum valve of this invention, it is a high melting-point member used for the electrode of a vacuum valve, Comprising: It consists of a composite metal of a refractory metal and a highly conductive metal, The former has a melting point of Cr, W, Mo, Ta, etc. The high melting point metal of 1800 degreeC or more is used, and it is preferable that the solid solution at the infiltration temperature in an integrated manufacturing process with respect to Cu, Ag, and Au as a highly conductive metal is 4% or less. Pure Cu is particularly preferred for the support member, but a highly conductive metal containing 4% or less of the above-mentioned refractory metal is used because of its low strength. Since the diffusing member contains a refractory metal as a main component, even if the refractory metal of the diffusing member is dissolved into the supporting member, the reduction in dimensions is small, and the component of the high melting point member can be effectively prevented from diffusing and dissolving into the supporting member. Can be.

As the high melting point member, 35 to 65% by weight of one or two or more of Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, Ti, Te, Si, Rh and Ru, in particular A composite metal containing 40 to 60% by weight and 35 to 65% by weight of Cu and containing Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, Ti, Te, Si, Rh and Ru It is preferable to use a composite material in which Cu is melt-impregnated into one or two or more porous green compacts or molded bodies or a porous molded article containing 40 wt% or less of Cu.

Further, as the diffusion member, a composite metal containing one or two or more of the total amounts of Cr, W, Mo, and Ta, of 80 to 97% by weight and 3 to 20% by weight of Cu. It is preferable to set it as the composite material which melted and impregnated Cu with the seed | species or 2 or more types of porous molded objects (a compacted body), or the porous molded object containing 10 weight% or less Cu in it. By refracting and solidifying refractory metals such as Cr from the diffusion member layer to the support member layer, the support member layer reaches a solid solution limit and does not employ the refractory metal in the high melting point member. The shape can be secured.

In addition, as a supporting member, one or two or more total amounts of Cr, Ag, W, V, Nb, Mo, Ta, Zr, Si, Be, Co, and Fe may be 4% by weight or less and an alloy of Cu, Ag, or Au. By doing so, strength sufficient to reinforce the high melting point member can be obtained.

In addition, according to the present invention, the support member is formed in the same process, and the total amount of Cr, Ag, W, V, Nb, Mo, Ta, Zr, Si, Be, Co, and Fe or 4 or more in total is 4% by weight. The following can be contained in Cu, Ag, or Au. Therefore, the mechanical strength, in particular, the yield strength can be greatly increased without significantly reducing the conductivity, and as a result, the contact resistance between the electrodes can be increased, the impact force at the time of opening and closing of the electrodes can be sufficiently coped with, and the deformation with time can be solved.

As described above, the high melting point member and the supporting member have a gold-integrated continuous structure, and a diffusion member is provided between the high melting point member and the supporting member to remove the high melting point member from the diffusion and solid solution. And it is possible to provide a high safety vacuum valve.

According to the manufacturing method of the base material of the vacuum valve of this invention, 1, 2 or more types of powders of Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, Ti, Te, Si, Rh, Ru Alternatively, Cu, Ag, and Au powders are mixed in a predetermined composition, and the mixed powder is molded at a predetermined pore content to form a porous green compact for electrodes. In addition, one or two or more powders of Cr, W, Mo, and Ta or a small amount of Cu, Ag, and Au powders are mixed in a predetermined composition, and the mixed powder is molded at a predetermined pore content to form a porous diffusion pressure. Make powder.

The latter diffusion green compact is superimposed on the former electrode green compact, and a block made of Cu, Ag, Au or these infiltrating alloys is placed thereon, followed by melting, thereby melting Cu or Cu alloy in the pores of the porous formed article. Impregnate the metal. Thereby, the electroconductive base material whose composition after infiltration is the content mentioned above is produced. After the infiltration is completed, the ingot is processed into an electrode having a predetermined shape.

As a heating environment, a method of heating the inside of the furnace in a vacuum state by placing a diffusion compact on the electrode green compact in the furnace and placing a metal mass serving as a support member thereon again. In addition, when producing a large amount of the base material of the present invention, it is also possible to produce a base material in a flow operation by providing a chamber for reducing and pressurizing air pressure in a heating furnace that always maintains a vacuum state.

In the infiltration of the highly conductive metal, the infiltration temperature and the holding time are set so that the infiltration is sufficiently performed in consideration of the melting point of the highly conductive metal to be melted, the wettability to the porous green compact or the molded body, the porosity of the porous molded body, and the like. As a result, an infiltration material having high strength and small specific resistance can be obtained, and a high-performance electrode can be obtained.

Moreover, in the manufacturing method of the conductive base material of the vacuum valve of this invention, as a metal member used as a support member, the member with a clearance gap, such as a metal ingot or powder body, can also be used.

The electrode in the present invention can be obtained by a combination of infiltration and casting technique in a desired shape as described above, but is obtained by cutting as the final shape described above.

1 is a schematic cross-sectional view showing a method for manufacturing a conductive base material 1 which is an embodiment of the present invention;

2 is a schematic cross-sectional view showing a manufacturing method of the conductive base material 1 of FIG.

3 is a schematic cross-sectional view of the conductive base material 1 of FIG.

4 is a partially enlarged schematic cross-sectional view of the conductive base material 1 of FIG.

5 is a schematic cross-sectional view of a conventional conductive base material 1,

6 is a structural example of an electrode unit using the base material of the present invention,

7 is a structural example of a vacuum valve using the electrode part of FIG. 6;

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Example 1

1 shows a cross section of an ingot of the conductive base material 1 produced by the manufacturing method of the present invention. The green compact 3 for electrodes, the green compact for diffusion 4, and the Cu ingot 5 for infiltration are piled up one after another on the graphite crucible 2. The electrode green compact 3 and the diffusing green compact 4 are produced as follows.

(1) 60 wt% Cr powder and 40 wt% Cu powder were mixed by V mixer, and then 80 mm in diameter and 80 mm in diameter and 9 mm in thickness were formed using a mold of 80 mm in diameter. Powder (3) was produced.

(2) After mixing 95% by weight of Cr powder and 5% by weight of Cu powder with a V mixer, a 80 mm diameter die was used and a diffusion pressure of 80 mm in diameter and 2 mm in thickness at 1.5 ton / cm 2. The molten compact 4 was produced.

(3) The diffusion green compact 4 is superimposed on the green compact for electrodes 3 placed on the bottom of the graphite crucible 2, and the ingot Cu ingot 5 having a diameter of 80 mm and a length of 75 mm is placed thereon again. The support member 5 which consists of these is overlapped and set.

(4) After covering the graphite crucible 2 with a lid and vacuuming, the infiltration conditions are heated at 1200 ° C. for 90 minutes in a vacuum of 6.7 × 10 ⁻³ Pa or less. At this time, as shown in FIG. 2, Cu of the electrode green compact 3, Cu of the green compact for diffusion 4, and Cu ingot 5 for infiltration are melt | dissolved, and accordingly, Cr and Cr of the green compact 3 for the electrode diffuse into the green compact 3 for the electrode and the Cu ingot 5 for infiltration. In place of Cr diffused from the electrode green compact 3, Cr of the diffusive green compact 4 diffuses into the electrode green compact 3, and most of Cr to be dissolved and dissolved in the Cu ingot 5 for infiltration. Since it is supplied from the diffusion green compact 4, Cr of the electrode green compact 3 does not run short, and Cr and Cu disperse | distribute uniformly.

(5) When these are taken out from the graphite crucible 2 after solidification, the conductive base material 1 is formed, and the appearance schematic view of the ingot from the cross section is shown in FIG. FIG. 4: is a schematic diagram of the result of having observed the structure of the high melting point metal layer 3A in FIG. 3 with the optical microscope. Cr and Cu are uniformly dispersed in the high melting point metal layer 3A as compared with those produced by the prior art. If the supporting member layer 5A is being melted, the molten Cu contains about 5% of Cr. However, after cooling, Cr is arbitrarily dispersed in the Cu of the supporting member at about (0.6 to 0.7%). Cr, which is not completely dissolved, hardens on the Cu surface due to the specific gravity difference with Cu.

5 shows a conventional technique, and in the conventional example of FIG. 5, when the Cr diffusion insulator 4 is not used during vacuum heating, Cr to be diffused and dissolved in the infiltration Cu ingot 5 Since all are supplied from the electrode green compact 3 and there is no Cr to replenish the diffused Cr, the area by the Cu agglomerate becomes larger than that of the Cu of the present invention, and the Cu agglomerates are easily melted by the arc at the time of interruption. .

Thus, according to this invention, as can be understood from FIG. 3, it turns out that the electrode which consists of the high melting point metal layer 3A and the support member layer 5A integrally can be manufactured. It is understood that the interface between the high melting point metal layer 3A and the support member layer 5A is completely integrated in the shape of gold, and joining by soldering or the like is unnecessary. By machining the obtained infiltration material into a desired shape, an electrode suitable for the purpose of the present invention can be produced.

Example 2

The performance of the electrically conductive base material 1 by this invention is demonstrated by Table 1 and Table 2.

No. Porous green compact thickness (mm) Thickness (mm) of each layer after infiltration (difference with green compact before infiltration) Cr content of 5A (wt%) 4 3 4 3A One none 9.1 - 4.6 (-4.5) 0.67 2 0.5 9.1 0 (-0.5) 5.8 (-3.3) 0.69 3 1.1 9 0 (-1.1) 6.7 (-2.3) 0.81 4 1.5 9 0 (-1.5) 7.9 (-1.1) 0.79 5 2 9.1 0 (-2.0) 8.6 (-0.5) 1.02 6 2.4 9.2 0 (-2.4) 9.0 (-0.2) 1.03 7 3.2 9.1 0.7 (-2.5) 9.1 (0) 0.98 8 3.6 9 1.0 (-2.6) 9.0 (0) 1.02

No. 4, composition: 95Cr-5Cu

No. 3, composition: 60Cr-38Cu-2Nb

Table 1 shows the result of measuring the thickness of the high-melting-point metal layer 3A after infiltration when the thickness of the diffusion green compact 4 was changed when the infiltration electrode was produced by the method shown in Example 1. And the result of measuring the Cr content of the supporting member layer 5A. The diameter of the infiltration material is 80 mm, the composition of the diffusion green compact 4 is Cr-5 wt% Cu, the composition of the electrode green compact 3 is Cr-38 wt% Cu-2 wt% Nb, and Molding was performed at a pressure of 1.5 ton / cm 2. The composition of the contact member after infiltration is Cr-59Cu-1Nb. In addition, pure Cu was used for the supply material for infiltration corresponding to a support member layer.

From the results in Table 1, it can be seen that the thickness of the high melting point metal layer 3A after infiltration can be secured by setting the thickness of the diffusion green compact 4 large (No. 7, 8). In this case, when the thickness of the spreading green compact 4 is 3 mm or more, the thickness reduction of the high melting point metal layer 3A is eliminated. As shown in Table 1, since Cr, which is a refractory metal, is dissolved in the supporting member layer 5A, the thickness of the diffusion green compact 4 or the electrode green compact 3A decreases, or the diffusion green compact 4 Since a) is a refractory metal as a main component, it is possible to prevent the reduction due to the solid solution of the high melting point metal layer 3A with a thin green compact.

By the same method, with respect to the diameter of the infiltration material, the thickness of the diffusion green compact 4 required to prevent the diffusion of the high melting point member and the decrease by the solid solution is increased as the diameter increases. It turns out that Cr of melting | fusing point metal layer 3A increases, and the thickness of Cr diffusion layer becomes large (No. 7 and No. 8). This is because the larger the diameter, the greater the absolute high capacity of Cu for infiltration. The high capacity also changes with the infiltration temperature and time. Therefore, the thickness of the green compact of the high melting point metal layer 3A is preferably set in consideration of the infiltration temperature, the holding time, the dimensions of the infiltration material, and the like.

Electric resistance value (μΩ ・ ㎝) Tensile test results (㎏ / ㎠) 0.2% yield strength Strength Comparative Example 1 4.82 (interface) 4 to 5 - Comparative Example 2 1.73 4 to 5 23-22 No. 7 2.24 12 to 13 24-23 No. 8 2.72 12 to 13 23-22

Table 2 shows the case where the high melting point metal layer 3A (composition: 40 wt% Cr-60 wt% Cu) and the pure Cu material are solder-bonded by the conventional method (conditions: temperature 800 ° C, in vacuum, Ni-based solder) Measurement results of the electrical resistance and strength of the junction (thickness: about 3 μm) (Comparative Example 1), the high melting point metal layer 3A (composition: 40 wt% Cr-60 wt% Cu) and pure Cu material annealed at 800 ° C Measurement results of electrical resistance and strength of pure Cu (Comparative Example 2) and the above-described No. of the present invention. The measurement results of electrical resistance and strength of the infiltrate obtained in 7 and No. 8 are shown. The electrical resistance was measured by a four-point resistance measurement method, and the strength was measured using an Amsler tensile tester.

The strength of the interface welded by the conventional method (comparative example 1) was weak, and the solder failure part was confirmed by the test piece of strength 12 kg / mm <2>. The electrical resistance value including the interface portion is about 3 to 4 times higher than that of 4.82 µPa · cm and the pure Cu material (Comparative Example 2). In contrast, the strengths of Nos. 7 and 8 were stable at 24 to 22 kg / mm 2, and no defects in the test pieces were observed.

Moreover, although the counterpart material of the high melting-point metal member of Comparative Example 1 is pure Cu, although the counterparts No.7 and No.8 are Cu alloys containing about 1% Cr, there is no interface, so the specific resistance is comparative example. It is less than 1. This shows that the resistance value of the junction interface by solder of the prior art is very large.

On the other hand, while the strength of the pure Cu of Comparative Example 2 is the maximum value of 22 to 23 kg / mm 2, 0.2% yield strength is very weak (4 to 5 kg / mm 2), and when used for the support member layer 5A to withstand a shock load It can be seen that it will deform with time.

On the other hand, the electrical resistance values of No. 7 and No. 8, which are Cu alloys containing Cr, showed 1.3 to 1.6 times the resistance compared to Comparative Example 2, but were about half or less compared to the conventional solder joint interface resistance. It can fully be used for the electrode material for vacuum circuit breakers.

In addition, the strength of No. 7 and No. 8 is the maximum strength of 24 to 22 kg / mm 2, but does not change much with pure Cu, but the 0.2% yield strength is doubled to 12 to 13 kg / mm 2. Moreover, even if it contains V, Ag, Nb, Zr, Si, W, Be, etc. in addition to Cr, it becomes a support member excellent in strength, without increasing an electrical resistance very much.

As described above, the conductive base material 1 containing Cr or V, Ag, Nb, Zr, Si, W, Be and the like according to the present invention is a high melting point metal layer 5A and a support member layer thinner than that. The cross-sectional shape of (5A) is used for electrodes such as a so-called T-shaped electrode or a cup-shaped seed-type electrode, a seed-type electrode having a main electrode and a coil electrode, and the impact when the electrode is opened and closed. Since deformation does not occur due to repetition of the load, welding failure due to deformation is prevented and reliability and safety are improved.

Figure 6 shows the electrode portion produced using the base material produced by the method of manufacturing the base material of the vacuum valve of the present invention described above.

6A is a cross-sectional view of the electrode portion, and FIG. 6B is a plan view of the electrode portion 602 viewed from the electrode surface.

The electrode portion 602 is an electrode having a linear groove, and has a linear arc liner 604 at an angle of 120 °, and a groove 606 is provided between each arc liner 604. The linear groove 606 can be formed by machining.

In addition, the electrode portion is composed of an interface between the high melting point metal layer 3A and the support member layer 5A, and the electrode portion is machined so that a flat disc is formed by the high melting point metal layer 3A and the support member layer 5A. Is formed. The supporting member layer 5A is formed with a supporting portion whose diameter is thinner than that of the high melting point metal layer 3A, and then a second disk 608 is formed.

In the structure of such an electrode part, when using the base material produced by the manufacturing method of this invention, compared with the base material by the prior art of FIG. 5, the interface by the high melting-point metal layer 3A and the support member layer 5A is Since it is formed stably, the thickness of the supporting member layer 5A and the high melting point metal layer 3A becomes uniform, the electrode contact surface is not melted even if an arc occurs at the time of interruption, so that the life of the electrode portion can be increased. do. In addition, since the thickness of the high melting point metal layer 3A can be configured uniformly, it is possible to increase the strength of the disk by the supporting member layer 5A and the high melting point metal layer 3A, thereby reinforcing the entire electrode portion. .

In addition, the use of expensive high melting point metals can be reduced as much as possible, and the high melting point metal layer can be made thin, so that the conductivity can be increased as compared with the electrode portion produced by the prior art.

Although not shown, a simple, so-called flat plate structure without a straight groove 606 is used for the electrode of the vacuum breaker of the type having a low short-circuit current, but the electrode produced according to the present invention also in these plate structure electrode portions. It is also possible to use wealth.

FIG. 7 is a cross-sectional view of a vacuum valve using the base material produced by the manufacturing method of the present invention described in FIG.

The basic configuration of this vacuum valve is basically the same as that shown in Japanese Patent Laid-Open No. 7-29461, and is fixed to the fixed side electrode sealing ring 704 in the upper opening of the cylinder 702 formed of an insulating material and movable to the lower opening. The side electrode sealing ring 706 is provided to form a vacuum chamber to form a vacuum chamber, and the fixed side electrode 710 is vertically installed at the middle of the fixed side electrode sealing ring 704, and the fixed side electrode ( The movable holder 708 supported by the guide 707 is freely provided in the middle of the movable side electrode sealing ring 706 located just below the 710, and the movable side electrode (708) is provided on the movable holder 708. By fixing the 712, the high melting point metal layer 722 of the movable side electrode 706 may be in contact with the high melting point metal layer 720 of the fixed side electrode 710. A metal bellows 730 is stretched and capped inside the movable side electrode sealing ring 706, and an intermediate shield member 740 of a metal plate forming a cylindrical shape is formed around both of the high melting point metal layers. The shield member 740 is provided with a movable side shield 742 on the movable side electrode 712 without impairing the insulation of the cylinder 702.

Further, the high melting point metal layers 720 and 722 are joined to the support members 750 and 752 obtained by the above-described production method of the present invention.

The supporting member 750 and the movable holder 708 are connected to the terminal and serve as a passage for the current. The above parts are assembled by placing a brazing filler material on the joint, and then heated and soldered in a vacuum atmosphere, whereby the inside of the vacuum valve shown in FIG. 7 can be vacuum sealed.

According to the vacuum valve according to this embodiment, since the base material produced in accordance with the present invention is used, it is difficult to melt the arc at the time of interruption, and the life of the vacuum valve can be longer than that of the conventional electrode.

As described above, in the conductive base material 1 of the present invention, Cu of the electrode green compact 3 and infiltration Cu ingot 5 melt at the time of heating, and thus, the diffusion green compact 4 Cr and Cr of the green compact 3 for the electrode diffuse into the green compact 3 for the electrode and the Cu ingot 5 for infiltration. Instead of Cr diffused from the electrode green compact 3, Cr of the diffusing green compact 4 diffuses from the electrode green compact 3, and most of Cr to be solid-dissolved in the infiltration Cu ingot 5 Since it is supplied from the diffusing green compact 4, Cr of the electrode green compact 3 does not run short, and the ratio of Cr and Cu disperse | distributes uniformly in the high melting-point metal layer 3A.

As a result, the electrode produced by the conductive base material 1 of the present invention becomes difficult to melt against the arc at the time of interruption, and not only can prolong the life compared with the conventional electrode, but also the high melting point metal layer 3A. Sufficient mechanical strength can also be obtained even at the interface between the support member layer 5A.

Claims (9)

In a method of manufacturing a base material of a vacuum valve having at least one pair of electrodes disposed in a vacuum valve and a supporting member extending from the electrode, the base material is an electrode obtained by compressing a mixed powder of a highly conductive metal powder and a high melting point metal powder. The green compact, the high melting point metal powder and the diffusion powder obtained by compacting a mixed powder of a smaller amount of the highly conductive metal powder than the high melting point metal powder and the supporting member using the highly conductive metal are laminated and heated in a heating furnace, A method of manufacturing a base material of a vacuum valve, comprising forming an electrode containing a green compact for electrodes and the support member in which a high melting point metal is dispersed. 2. The method according to claim 1, wherein after heating the green compact for the electrode, the green compact for diffusion, and the support member, the components of the green compact for diffusion diffuse into the green compact for the electrode and the support member. A method for manufacturing a base material of a vacuum valve, characterized in that the components of the green body disappear. 2. The method of manufacturing a base material of a vacuum valve according to claim 1, wherein the electrode green compact, the green compact for diffusion, and the support member are disposed in the heating furnace, and then heated in a vacuum state. 2. The base material of the vacuum valve according to claim 1, wherein the electrode compact, the diffusion compact and the support member are disposed in the heating furnace and heated after the inside of the heating furnace is in a vacuum state. Manufacturing method. The method of claim 1, wherein the base material is an electrode green compact obtained by powdering a mixed powder of 65 to 35% by weight (%) of high melting point metal powder and 35 to 65% (%) of highly conductive metal powder; A method for producing a base material of a vacuum valve, characterized by using a diffusion green compact obtained by mixing a mixed powder of 80 wt% (%) of high melting point metal powder and 3 to 20 wt% (highly conductive metal powder). The method of claim 5, wherein the conductive base material is an electrode green compact obtained by compacting a mixed powder of 65 to 35 weight (%) Cr powder and 35 to 65 weight (%) Cu powder, and 97 to 80 weight (%) Method for producing a base material of a vacuum valve, characterized in that for use a diffusion green compact obtained by compacting a mixed powder mixed with Cr powder of 3) and Cu powder of 3 to 20% by weight (%). The method of claim 1, wherein the green compact for the electrode and the green compact for diffusion are high melting point metals Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, Ti, Te, Si, Rh and Ru Or a mixture of one or two or more thereof, or a compound thereof and a highly conductive metal composed of Cu, Ag, or Au, or a highly conductive metal mainly containing them, and the support member layer is a highly conductive metal or a highly conductive metal. The manufacturing method of the base material of the vacuum valve which consists of an alloy containing these. The method of claim 1, wherein the green compact for the electrode is a high melting point metal, one or two of Cr, W, Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, Ti, Te, Si, Rh and Ru It consists of a composite metal containing 35 to 65% by weight of the total amount of species or more and 35 to 65% by weight of Cu as a highly conductive metal, and the diffusion green compact is a high melting point metal, one or two of Cr, W, Mo, and Ta. It is composed of a composite metal containing 80 to 97% by weight of the total amount of species or more and 3 to 20% by weight of Cu as a highly conductive metal, and the support member layer is made of Cr, Ag, W, V, Nb, Mo, Ta, Zr, Si. A method for producing a base material of a vacuum valve, wherein the total amount of one, two or more of Be, Co, and Fe is 4 wt% or less and an alloy of Cu, Ag, or Au. The method of manufacturing a base material of a vacuum valve according to any one of claims 1 to 8, wherein the base material according to the production method has a 0.2% yield strength of 10 kg / mm 2 or more and a specific resistance of 2.8 μm cm or less.