JP3273018B2 - Method for manufacturing base material of vacuum valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a base material of a vacuum valve used for an electrode, a support member and the like.

[0002]

2. Description of the Related Art Vacuum circuit breakers are used together with disconnectors, grounding switches, lightning arresters, and current transformers, and are used for high-rise buildings, hotels, intelligent buildings, underground shopping centers, oil complexes, various factories, stations, hospitals, halls, subways, This device is used as high-voltage receiving and transforming equipment such as public facilities such as water and sewage.

A pair of fixed electrodes and a movable electrode are arranged in a vacuum valve installed in the vacuum circuit breaker.
Support members connected to the back surfaces of both electrodes extend to the outside, and these electrodes and the support members are formed of a conductive base material. The two electrodes are made of a high melting point member.

[0004] High melting point members are directly exposed to arcs to open and close high voltages and large currents. Satisfactory characteristics required for high melting point members are high breaking capacity, high withstand voltage, low contact resistance (excellent electrical conductivity), and excellent welding resistance. And basic requirements such as a small amount of contact wear and a small cutting current value.

[0005] However, it is difficult to satisfy all of these characteristics, and in general, a material is used which emphasizes particularly important characteristics according to the application and sacrifices other characteristics to some extent. As a contact material for breaking a large current and a high voltage, JP-A-63-96204 discloses Cr or Cr-
A method of infiltrating Cu into a Cu skeleton is disclosed. A similar manufacturing method is also disclosed in Japanese Patent Publication No. 50-21670.

[0006] The method of manufacturing the high melting point member includes Cr powder, Cu
Powder, W powder, Co powder, Mo powder, V powder, Nb powder or a mixed powder of these are molded into a predetermined composition, shape, and vacancy amount, and after sintering, Cu or a molten alloy thereof is poured into a skeleton of a sintered body. A contact member manufactured by a so-called infiltration method of infiltrating or by a so-called powder metallurgy method in which the density is made 100% in a sintering process before infiltration is further machined into a predetermined shape. The support member is cut out from a pure Cu material into a predetermined shape.

After the infiltration in this way, a support member is brazed to the back of the machined electrode to form a series of electrode structures. However, in the brazing method, a brazing material having good wettability is put between each of the high melting point member and the supporting member, and the temperature is raised in a vacuum or a reducing atmosphere, and brazing is performed. The electrode configured as described above requires a great deal of labor and time to assemble each member for machining and brazing, and at the same time, may cause breakage or dropout of the electrode material due to poor brazing.

Therefore, in the manufacturing process, as a method of integrating the above-mentioned high melting point member and the supporting member, a mixed powder composed of the components of the high melting point member is placed on a skeleton formed into a predetermined composition, shape and porosity. So-called integral infiltration in which the high-conductivity metal constituting the support member is placed, the temperature is raised, and the high-conductivity metal is infiltrated into the high-melting-point member, and the support member is formed with the remainder of the high-conductivity metal. A law was developed. This manufacturing method is disclosed in JP-A-7-29461.

[0009]

According to the integral infiltration method,
This eliminates the need for machining each component and assembling parts for brazing, dramatically improving productivity and preventing electrodes from being broken or falling off due to poor brazing, and providing electrodes with excellent reliability and safety. can get. Also, at the time of infiltration, by high-temperature heating to dissolve the highly conductive metal constituting the support member,
A part of the components constituting the high melting point member is melted and diffused and solid-dissolved in the molten high-conductivity metal, so that the strength of the supporting member is improved.

However, on the other hand, there is a problem that the high melting point member of the obtained electrode is eroded on the support member side due to diffusion and solid solution, and the desired thickness and shape of the high melting point member cannot be obtained. As a countermeasure, the amount of diffusion of the high melting point member toward the support member and the amount of reduction due to solid solution are predicted, and the skeleton of the high melting point member is made thicker by the amount of reduction in advance, so that the thickness of the high melting point member after infiltration is Well, the shape is secured.

According to this measure, the amount of the raw material corresponding to the high melting point member is required to be increased by the amount reduced by the diffusion and solid solution.
Manufacturing costs increase. Further, since the amount of reduction of the high melting point member changes remarkably due to variations in the composition and the amount of vacancies in the skeleton, as shown in FIG. 5 as a conventional technique, Cr is used as a high melting point metal and Cu is used as a high conductive metal.
When using, the interface position with the high melting point member becomes an irregular coarse metal structure, not only lowering the production yield,
In addition, a large amount of Cu lumps are formed on the electrode contact surface, and are easily melted by an arc at the time of interruption, and the life of the electrode is short. In addition, when the vacuum valve using the electrode and the support portion of the coarse metal structure has been operated for many years, a crack is generated from the boundary between Cu and Cu, and air from the outside enters the vacuum valve from the crack of the support portion and the electrode. Penetrates, insulation is deteriorated, and the life of the vacuum valve is shortened.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a base material of a vacuum valve in which the life of an electrode hardly melted by an arc at the time of interruption and the life of a vacuum valve are increased.

[0013]

According to a first aspect of the present invention, there is provided a method for manufacturing a base material of a vacuum valve, comprising: at least one pair of electrodes disposed in the vacuum valve;
A method of manufacturing a base material of a vacuum valve comprising a support member extending from an electrode, wherein the base material is a green compact for an electrode obtained by pressing a mixed powder of a highly conductive metal powder and a high melting point metal powder, and a high melting point metal powder. And a diffusion compact obtained by compacting a mixed powder of a high-conductivity metal powder and a small amount of the high-conductivity metal powder, and a support member using a high-conductivity metal are stacked in a heating furnace and heated. ,
An object of the present invention is to form an electrode including a green compact for an electrode and a support member in which a high melting point metal is dispersed.

According to a second aspect of the present invention, in the method of manufacturing a base material for a vacuum valve, the components of the diffusion green compact are heated after the electrode green compact, the diffusion green compact and the supporting member are heated. It is to diffuse into the electrode compact and the support member, and the diffusion compact disappears.

According to a third aspect of the present invention, there is provided a method of manufacturing a base material for a vacuum valve, comprising placing a green compact for an electrode, a green compact for diffusion, and a support member in a heating furnace, and thereafter heating in a vacuum state. It is in.

According to a fourth aspect of the present invention, in the method of manufacturing a base material for a vacuum valve, after the inside of the heating furnace is evacuated, the green compact for electrodes, the compact for diffusion and the supporting member are arranged in the heating furnace. And then heating.

According to a fifth aspect of the present invention, in the method of manufacturing a base material for a vacuum valve, the base material comprises a high melting point metal powder of 65 to 35% by weight and a high conductive metal powder of 35 to 65% by weight. A powder mixture obtained by mixing a powder compact for an electrode obtained by compacting a powder mixture obtained by mixing a high melting point metal powder of 97 to 80% by weight (%) and a high conductive metal powder of 3 to 20% by weight (%) is pressed. And a powdered diffusion compact.

According to a sixth aspect of the present invention, in the method of manufacturing a base material for a vacuum valve, the conductive base material is a mixture of 65 to 35% by weight of Cr powder and 35 to 65% by weight of Cu powder (%). An electrode compact obtained by compacting the mixed powder and 97 to 80% by weight of C
An object of the present invention is to use a diffusion green compact obtained by compacting a mixed powder obtained by mixing r powder and Cu powder of 3 to 20% by weight (%).

According to a seventh aspect of the present invention, in the method of manufacturing a base material for a vacuum valve, the green compact for electrodes and the green compact for diffusion are Cr, W, Mo, Ta, Nb, Be, Hf, I
1 of r, Pt, Zr, Ti, Te, Si, Rh and Ru
A kind or a mixture of two or more kinds thereof or a compound thereof;
It consists of a highly conductive metal made of u, Ag or Au or an alloy thereof mainly composed of a highly conductive metal, and the supporting member is made of a highly conductive metal or an alloy containing a highly conductive metal. .

[0020] In the method for manufacturing a base material of a vacuum valve according to claim 8 of the present invention, the electrode green compact is made of Cr, W,
Mo, Ta, Nb, Be, Hf, Ir, Pt, Zr, T
One or more of i, Te, Si, Rh and Ru in a total amount of 35 to 65% by weight, and Cu 35 to
And 65% by weight of a composite metal, and the green compact for diffusion is one or two of Cr, W, Mo and Ta as high melting point metals.
A composite metal containing 80 to 97% by weight of the total amount of the above species and 3 to 20% by weight of Cu as a highly conductive metal, and the supporting member is made of Cr, Ag, W, V, Nb, Mo, Ta, Zr, S
An object of the present invention is to use an alloy of Cu, Ag, or Au with one or more of i, Be, Co, and Fe in a total amount of 4% by weight or less.

In the method for manufacturing a base material of a vacuum valve according to the ninth aspect of the present invention, the base material manufactured by this manufacturing method is used in a vacuum valve.
It has a 2% proof stress of 10 kg / mm ₂ or more and a specific resistance of 2.8 μΩcm or less.

That is, according to the method of manufacturing the base material of the vacuum valve of the present invention, the high melting point member used for the electrode of the vacuum valve is made of a composite metal of a refractory metal and a highly conductive metal. Melting point of Cr, W, Mo, Ta, etc. about 1800
It is preferable to use a metal having a high melting point of not less than ° C. and a solid solution amount of 4% or less at the infiltration temperature in the integrated manufacturing step with respect to Cu, Ag, and Au as the highly conductive metals. Pure Cu is particularly preferable for the support member, but a highly conductive metal containing 4% or less of the above-described refractory metal is used because of its low strength. Since the diffusion member contains a refractory metal as a main component, even if the refractory metal of the diffusion member is solid-dissolved in the support member side, the reduction in dimension is small, and the components of the high melting point member diffuse and solidify in the support member side. Melting can be efficiently prevented.

Further, as the high melting point member, Cr, W, M
o, Ta, Nb, Be, Hf, Ir, Pt, Zr, T
one or more of i, Te, Si, Rh and Ru in a total amount of 35 to 65% by weight, particularly 40 to 60% by weight, and Cu3
A composite metal containing 5 to 65% by weight of Cr, W, M
o, Ta, Nb, Be, Hf, Ir, Pt, Zr, T
One, two or more kinds of porous compacts or compacts of i, Te, Si, Rh and Ru or 40% by weight or less of C
It is preferable to use a composite material in which a porous molded body containing u is melt-impregnated with Cu.

Further, Cr, W, Mo can be used as the diffusion member.
And one or more of Ta is a composite metal containing 80 to 97% by weight and 3 to 20% by weight of Cu;
One or two or more kinds of W, Mo and Ta porous compacts (compacts) or a composite material obtained by melting and impregnating Cu into a porous compact containing 10% by weight or less of Cu. preferable. The diffusion of the refractory metal such as Cr from the diffusion member layer to the support member layer side causes the solid solution of the refractory metal such as Cr, so that the support member layer reaches the solid solution limit, and the refractory metal in the high melting point member does not form a solid solution. Desired dimensions and shape can be secured.

Further, Cr, Ag, W,
V, Nb, Mo, Ta, Zr, Si, Be, Co and F
e or one or two or more kinds of e and 4% by weight or less and Cu,
By using an alloy with Ag or Au, sufficient strength for reinforcing the high melting point member can be obtained.

Further, according to the present invention, the support member is formed in the same process, and the Cr, Ag, W, V, Nb, Mo, T
One, two or more of a, Zr, Si, Be, Co and Fe may be contained in Cu, Ag or Au in a total amount of 4% by weight or less. Therefore, the mechanical strength, particularly the proof stress, can be greatly increased without significantly lowering the conductivity. As a result, the contact resistance between the electrodes can be increased, and the impact force when opening and closing the electrodes can be sufficiently coped with. Deformation can also be solved.

As described above, the high melting point member and the supporting member have a monolithically continuous integrated structure, and a diffusion member is provided between the high melting point member and the supporting member to diffuse the high melting point member.
By eliminating the decrease due to solid solution, a highly reliable and safe vacuum valve can be provided.

According to the method of manufacturing the base material of the vacuum valve of the present invention, Cr, W, Mo, Ta, Nb, Be, Hf, I
One or more powders of r, Pt, Zr, Ti, Te, Si, Rh, and Ru, or Cu, Ag, and Au powders are mixed into a predetermined composition, and the mixed powder contains a predetermined void. To produce a porous electrode compact. Cr, W,
Mo or Ta powder or two or more powders or a small amount of Cu, Ag and Au powders are mixed with a predetermined composition, and the mixed powder is formed into a predetermined void content to be used for porous diffusion. Make green compacts.

The former compact for diffusion is placed on the former compact for electrode, and a block made of Cu, Ag, Au or their infiltration alloy is further placed thereon. Is melted to impregnate the voids of the porous molded body with a metal such as Cu or a Cu alloy. Thus, a conductive base material whose composition after infiltration has the above-mentioned content is manufactured. The ingot after completion of infiltration is processed into an electrode having a predetermined shape.

As an environment for heating, a diffusion compact is placed on an electrode compact in a heating furnace, and a metal block serving as a support member is further placed thereon. The method of heating the inside of the heating furnace in a vacuum state can be adopted.When a large amount of the base material of the present invention is manufactured, a heating furnace that always maintains a vacuum state is provided with a chamber for reducing and increasing the air pressure. It is also possible to produce a base material in a flow operation.

In the infiltration of a highly conductive metal, the infiltration is sufficient in consideration of the melting point of the highly conductive metal to be melted, wettability to a porous compact or a compact, porosity of a porous compact. The infiltration temperature and the holding time are set so that As a result, the above-described infiltration material having high strength and low specific resistance can be obtained, and a high-performance electrode can be obtained.

Further, in the method for producing a conductive base material of a vacuum valve according to the present invention, as a metal member serving as a support member, a member having a gap such as a metal ingot or powder can be used.

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

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a cross section of an ingot of a conductive base material 1 manufactured by the manufacturing method of the present invention. An electrode green compact 3, a diffusion green compact 4, and an infiltration Cu ingot 5 are sequentially stacked on a graphite crucible 2 and set. The electrode compact 3 and the diffusion compact 4 are manufactured as follows.

(1). After mixing 60% by weight of Cr powder and 40% by weight of Cu powder with a V mixer, the diameter is 80 mm.
80 m diameter at 1.5 ton / cm ₂ molding pressure
An electrode compact 3 having a thickness of 9 mm and a thickness of 9 mm was produced.

(2). Also, 95% by weight of Cr powder and 5%
% By weight and mixed with a V mixer by a V mixer.
Using a mold having a diameter of 0 mm and a molding pressure of 1.5 ton / cm ₂ , the diameter is 80 mm.
A green compact 4 for diffusion having a thickness of 2 mm and a thickness of 2 mm was produced.

(3). A diffusion compact 4 is placed on the electrode compact 3 placed on the bottom of the graphite crucible 2, and a support member 5 made of an infiltration Cu ingot 5 having a diameter of 80 mm and a length of 75 mm is further placed thereon. Set.

(4). After the graphite crucible 2 is covered with a lid and evacuated, the infiltration condition is heating 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 and C of the diffusion green compact 4 are used.
The u and the Cu ingot for infiltration 5 are melted, and accordingly, the Cr of the green compact for diffusion 4 and the Cr of the green compact for electrode 3 diffuse into the green compact for electrode 3 and the Cu ingot for infiltration 5. Cr of diffusion compact 4 instead of Cr diffused by electrode compact 3
Is diffused into the electrode compact 3 and the Cr to be diffused and dissolved in the infiltration Cu ingot 5 is mostly supplied from the diffusion compact 4, so that the Cr in the electrode compact 3 is insufficient. In addition, Cr and Cu are uniformly dispersed in proportion.

(5). When these are taken out of the graphite crucible 2 after solidification, the conductive base material 1 is formed, and FIG. 3 is a schematic external view of the ingot in cross section. FIG. 4 is a schematic view showing the result of observing the structure of the high melting point metal layer 3A in FIG. 3 with an optical microscope. Cr and Cu are more uniformly dispersed in the refractory metal layer 3A than those produced by the conventional technique. If the support member layer 5A is being melted, about 5% of Cr is contained in the melted Cu, but after cooling, the Cr of the support member contains about (0.6%) Cr. About 0.7%), and the undissolved Cr is Cu due to the difference in specific gravity from Cu.
Solidifies on the surface.

FIG. 5 shows the prior art. In the conventional example shown in FIG. 5, when the green compact 4 for diffusing Cr is not used during vacuum heating, the Cr is diffused and dissolved in the Cu ingot 5 for infiltration. Since all of the Cr to be supplied is supplied from the electrode compact 3 and there is no Cr that supplements the diffused Cr, the area of the Cu lump is larger than the Cu area of the present invention, and the Cu lump melts due to the arc at the time of interruption. It's easy to do. In addition, external air enters the vacuum valve through a crack at the boundary surface between Cu and Cu, causing insulation deterioration and shortening the life of the vacuum valve.

Thus, according to the present invention, as can be seen from FIG. 3, it can be seen that an electrode in which the refractory metal layer 3A and the support member layer 5A are integrally formed can be sufficiently manufactured.
It can be seen that the respective interfaces between the refractory metal layer 3A and the support member layer 5A are completely integrated in a metallographic manner, and that joining by brazing or the like is unnecessary. By machining the infiltration material thus obtained into a desired shape,
An electrode for the purpose of the present invention can be manufactured. Further, Cr melted at the boundary surface between Cu and Cu increases the strength and makes it difficult for cracks to occur, and can extend the life of the vacuum valve as compared with FIG.

Example 2 The performance of the conductive base material 1 according to the present invention will be described with reference to Tables 1 and 2.

[0044]

[Table 1]

Table 1 shows that when the thickness of the green compact 4 for diffusion was changed when the infiltration electrode was manufactured by the method shown in Example 1, the high melting point metal layer 3A after infiltration was formed. It is a result of measuring the thickness and a result of measuring the Cr content of the support member layer 5A. The diameter of the infiltrant is 80 mm, the composition of the green compact 4 for diffusion is Cr-5 wt% Cu, and the composition of the green compact 3 for electrodes is Cr-
38% by weight Cu-2% by weight Nb, molding pressure 1.5ton / c
It was molded in m _2. This is because the composition of the contact member after infiltration is Cr
-59Cu-1Nb. It should be noted that pure Cu was used as a supply material for infiltration corresponding to the support member layer.

From the results shown in Table 1, by setting the thickness of the green compact 4 for diffusion to be large, the high melting point metal layer 3 after infiltration was obtained.
It can be seen that the thickness of A can be secured (NO7, 8). In this case, if the thickness of the green compact 4 for diffusion is 3 mm or more, the thickness of the refractory metal layer 3A does not decrease. As shown in Table 1, Cr, which is a refractory metal, forms a solid solution in the supporting member layer 5A, so that the thickness of the diffusion compact 4 or the electrode compact 3A decreases. Since the body 4 contains a refractory metal as a main component, it is possible to efficiently prevent the refractory metal layer 3A from being reduced by solid solution with a thin green compact.

In a similar manner, the thickness of the green compact 4 for diffusion required to prevent the diffusion of the high melting point member and the decrease due to solid solution with respect to the diameter of the infiltration material increases as the diameter increases. It can be seen that the amount of Cr in the high melting point metal layer 3A on the layer 5A side increases and the thickness of the Cr diffusion layer increases (No. 7 and N).
o. 8). This is because the larger the diameter, the larger the absolute solid solution amount of Cu for infiltration, and the solid solution amount also changes depending on the infiltration temperature and time. Therefore, it is desirable to set the thickness of the green compact of the high melting point metal layer 3A in consideration of the infiltration temperature, the holding time, the dimensions of the infiltration material, and the like.

[0048]

[Table 2]

Table 2 shows that the high melting point metal layer 3A (composition: 40% by weight Cr-60% by weight Cu) and a pure Cu material were brazed by a conventional method (conditions: 800 ° C., vacuum, Ni-based brazing material). ), The electrical resistance and strength of the joint (thickness: about 3 μm) (Comparative Example 1), the refractory metal layer 3A (composition: 40 wt% Cr-60 wt% Cu) and pure Cu material Was measured at 800 ° C., and the electrical resistance and strength of pure Cu were measured (Comparative Example 2). 7 and N
o. 8 shows measurement results of electric resistance and strength of the infiltration material obtained in FIG. Electric resistance measurement is a four-point resistance measurement method.
The strength measurement was performed using an arm-slur tensile tester.

[0050] Brazing bonding was performed by a conventional method (Comparative Example 1).
The strength of the interface was weak, and a bad brazing portion was confirmed on a test piece having a strength of 12 kg / mm ₂ . The electric resistance including the interface is 4.82 μΩ · cm, which is about 3 to 4 times higher than the pure Cu material (Comparative Example 2). No. 7 and no. The strength of Sample No. 8 was stable at 24 to 22 kg / mm _2, and no defect was observed on the test piece.

Further, while the counterpart material of the high melting point metal member of Comparative Example 1 was pure Cu, 7 and no. Although the mating material of No. 8 is a Cu alloy containing about 1% of Cr, there is no interface, so the specific resistance is smaller than that of Comparative Example 1.
This indicates that the resistance value of the joint interface by the conventional brazing is very large.

On the other hand, the strength of pure Cu of Comparative Example 2 was a maximum value of 2
0.2% proof stress is 4 ~ 5k while ₂ ~ 23kg / mm2
g / mm _{2, which} is very soft, indicating that when used for the support member layer 5A, it cannot withstand an impact load and is deformed over time.

On the other hand, No. 2 which is a Cu alloy containing Cr was used. 7 and no. The electrical resistance of No. 8 was 1.3 to 1.6 times that of Comparative Example 2, but was about half or less as compared with the conventional brazing junction interface resistance, and the vacuum was sufficiently interrupted. It can be used for dexterous electrode materials.

No. 7 and no. The strength of No. 8 is 24 to 22 kg / mm _{2 at} maximum strength, which is not much different from pure Cu, but the 0.2% proof stress is doubled to 12 to 13 kg / mm ₂ . In addition to V, Ag, N
Even when b, Zr, Si, W, Be, or the like is contained, the supporting member is excellent in strength without increasing the electric resistance so much.

As described above, the conductive base material 1 containing Cr or V, Ag, Nb, Zr, Si, W, Be, or the like according to the present invention was formed by cutting the refractory metal layer 5A and the diameter to be smaller than this. When used for an electrode such as a so-called T-shaped electrode or a cup-shaped vertical magnetic field electrode, a vertical magnetic field electrode having a main electrode and a coil electrode having a cross section composed of the support member layer 5A, and this electrode is opened and closed. Since the deformation due to the repetitive impact load does not occur, welding failure due to the deformation is prevented, and the reliability and safety are improved.

FIG. 6 shows an electrode portion manufactured using the base material manufactured by the above-described method of manufacturing the base material of the vacuum valve of the present invention.

Here, FIG. 6A is a 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 section 602 is an electrode having a straight groove, and has a linear arc liner 604 at an angle of 120 °, and a groove 60 is provided between each arc liner 604.
6 are provided. This linear groove 606 can be formed by machining.

The interface between the high melting point metal layer 3A and the supporting member layer 5A as the coil electrode is formed on the main electrode as the electrode portion, and a flat disk is formed by the high melting point metal layer 3A and the supporting member layer 5A. The electrodes are formed by machining. Then, a support portion having a smaller diameter than the refractory metal layer 3A is formed on the support member layer 5A, and then a second disk 608 is formed.

In such a configuration of the electrode portion, when the base material manufactured by the manufacturing method of the present invention is used, the refractory metal layer 3A and the supporting member layer 5A are compared with the base material according to the prior art shown in FIG. Is formed stably, so that the thickness of the support member layer 5A and the refractory metal layer 3A become uniform, and the electrode contact surface does not melt even if an arc is generated at the time of interruption.
The service life of the electrode portion can be extended. In addition, since the thickness of the high melting point metal layer 3A can be made uniform, the strength of the disk formed by the support member layer 5A and the high melting point metal layer 3A can be increased, and the entire electrode portion can be strengthened.

Since the use of expensive high-melting-point metal as a material can be minimized and the high-melting-point metal layer can be thinned, the conductive material is more conductive than the electrode portion manufactured by the prior art. Can be enhanced.

Although not shown, a simple so-called flat plate structure without a linear groove 606 is used as an electrode of a vacuum circuit breaker of a type having a small short-circuit current. It is also possible to use an electrode unit manufactured according to the present invention.

FIG. 7 is a sectional view of a vacuum valve using a base material manufactured by the manufacturing method of the present invention described with reference to FIG. 6 as an electrode.

The basic structure of this vacuum valve is disclosed in
The structure is the same as that shown in Japanese Patent Application Laid-Open No. 29461, and a fixed-side electrode seal ring 704 is provided in an upper opening of a cylinder 702 made of an insulating member formed of an insulating material, and a movable-side electrode seal ring is provided in a lower opening. 706 is provided to form a vacuum chamber, a fixed-side electrode 710 is provided in the middle of the fixed-side electrode seal ring 704, and the movable-side electrode seal ring 706 located immediately below the fixed-side electrode 710. A movable holder 708 supported by a guide 707 is provided in the middle in a movable manner, and a movable electrode 712 is fixed to the movable holder 708 so that the movable holder 708 is movable with respect to the high melting point metal layer 720 of the fixed electrode 710. The refractory metal layer 722 of the side electrode 706 can be contacted. Inside of the movable electrode seal ring 706 and the movable holder 70
8 and a part of the support member 752, the metal bellows 7
And an intermediate shield member 740 formed of a cylindrical metal plate around the refractory metal layers.
The shield member 740 is mounted on the cylinder 70
2, and a movable side shield 742 is provided on a part of the support member 752.

Further, the refractory metal layers 720 and 722
Is a supporting member 75 obtained by the above-described method of the present invention.
0, 752.

The support member 750 and the movable holder 708 are connected to terminals, and serve as a current path. After the above components are assembled by placing a brazing material on the joint, the components are heated in a vacuum atmosphere and brazed, so that 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 manufactured according to the present invention is used, it is difficult to be melted by the arc at the time of interruption, and the life is extended as compared with the conventional electrode. It becomes possible.

[0068]

As described above, in the conductive base material 1 of the present invention, the Cu of the electrode compact 3 and the Cu ingot 5 for infiltration are melted at the time of heating. Cr and Cr of electrode compact 3 are electrode compact 3 and infiltration C
It diffuses to u ingot 5. Cr of the diffusion compact 4 is diffused into the electrode compact 3 instead of Cr diffused by the electrode compact 3, and most of the Cr to be dispersed and dissolved in the infiltration Cu ingot 5 is the diffusion compact. Since it is supplied from the body 4, Cr of the electrode green compact 3 is not insufficient, and Cr and Cu are uniformly dispersed in the high melting point metal layer 3A.

As a result, the electrode manufactured using the conductive base material 1 of the present invention is not easily melted by an arc at the time of interruption, and can not only have a longer service life than the conventional electrode, Sufficient mechanical strength can be obtained even at the interface between the melting point metal layer 3A and the support member layer 5A.

Further, a pair of electrodes corresponding to each other and a supporting member extending from the back surface of the electrode to the outside of the vacuum valve are formed of C inside the vacuum valve manufactured by the conductive base material 1 of the present invention.
The boundary between u and Cu has a dense metal structure due to the nucleus of Cr as compared with the coarse metal structure of only Cu crystal. During operation of the vacuum valve for many years, air enters the vacuum valve from the electrode through the support through the support. This makes it difficult for the vacuum valve to deteriorate and the vacuum to be deteriorated more hardly than the conventional vacuum valve, and the life of the vacuum valve can be greatly extended as compared with the conventional vacuum valve. The support is also C
The mechanical strength is increased by the amount of diffusion of Cr as compared with the u single genus, so that no reinforcement is required unlike the conventional case.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view when a conductive base material according to an embodiment of the present invention is housed in a crucible.

FIG. 2 is a schematic cross-sectional view of the infiltration conductive base material when the conductive base material 1 of FIG. 1 is melted in a crucible.

FIG. 3 is a schematic sectional view of the infiltration conductive base material 1 of FIG. 2;

FIG. 4 is a detailed schematic cross-sectional view enlarging a portion of the infiltration conductive base material 1 of FIG. 3;

FIG. 5 is a schematic sectional view of a conventional conductive base material 1.

FIGS. 6A and 6B are a side sectional view of an electrode portion using the base material of the present invention and a plan view of FIG.

FIG. 7 is a side sectional view of a vacuum valve using the electrode unit of FIG. 6;

[Description of Signs] 1 ... conductive base material, 2 ... graphite crucible, 3 ... compact for electrode,
3A: High melting point metal layer, 4: Green compact for diffusion, 5: C for infiltration
u ingot, 5A: support member layer.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Tanimizu 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside the Kokubu Plant of Hitachi, Ltd. No. 1 Hitachi, Ltd. Kokubu Plant (72) Inventor Katsuzo Kuroda 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Hitachi Ltd. Kokubu Plant (72) Inventor Hitoshi Okabe Kokubu, Hitachi City, Ibaraki Prefecture 1-1-1, Machi, Kokubu Plant, Hitachi, Ltd. (72) Inventor Noboru Baba 7-1, 1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (56) References JP Hei 7 JP-A-335092 (JP, A) JP-A-7-320608 (JP, A) JP-A-6-203692 (JP, A) JP-A-4-154017 (JP, A) JP-A-4-137326 (J , A) JP flat 4-129119 (JP, A) JP Akira 63-96204 (JP, A) Tokuoyake Akira 58-649 (JP, B2) (58 ) investigated the field (Int.Cl. ^7, DB (Name) H01H 33/66

Claims (9)

(57) [Claims] 1. A method for manufacturing a base material of a vacuum valve comprising at least a pair of electrodes arranged in a vacuum valve and a support member extending from the electrode, wherein the base material is a highly conductive metal powder and a high melting point metal. A green compact for an electrode obtained by compacting a mixed powder with a powder; a green compact for diffusion obtained by compacting a mixed powder of a high melting metal powder and a small amount of a highly conductive metal powder than the high melting metal powder; A support member using a conductive metal is stacked and disposed in a heating furnace and heated to form an electrode including the electrode compact and the support member in which a high melting point metal is dispersed. A method for manufacturing a base material for a vacuum valve. 2. The method of manufacturing a base material for a vacuum valve according to claim 1, wherein after heating the green compact for an electrode, the green compact for diffusion and the support member, the green compact for diffusion. Wherein the component (d) diffuses into the electrode compact and the support member, and the component of the diffusion compact disappears. 3. The method for manufacturing a base material for a vacuum valve according to claim 1, wherein the green compact for an electrode, the green compact for diffusion, and the support member are arranged in the heating furnace, and then the vacuum is applied. A method for producing a base material of a vacuum valve, comprising heating in a state. 4. The method for producing a base material of a vacuum valve according to claim 1, wherein the heating furnace is evacuated to a vacuum state.
A method for manufacturing a base material for a vacuum valve, wherein the green compact for an electrode, the green compact for diffusion, and the support member are arranged in the heating furnace and heated. 5. The method for manufacturing a base material of a vacuum valve according to claim 1, wherein the base material is 65 to 35% by weight (%) of a high melting point metal powder and 35 to 65% by weight (%) of a highly conductive metal. A powder compact for an electrode obtained by compacting a mixed powder obtained by mixing powder and
A vacuum characterized by using a diffusion compact obtained by compacting a mixed powder obtained by mixing a high melting point metal powder of about 80% by weight (%) and a highly conductive metal powder of 3 to 20% by weight (%). A method of manufacturing a base material for a valve. 6. The method of manufacturing a base material of a vacuum valve according to claim 5, wherein the base material has 65 to 35% by weight of C.
An electrode compact obtained by compacting a mixed powder obtained by mixing r powder and 35 to 65 wt (%) Cu powder, and 97 to 80 wt (%)
A method for producing a base material for a vacuum valve, characterized by using a diffusion compact obtained by compacting a mixed powder obtained by mixing a Cr powder and a Cu powder of 3 to 20% by weight (%). 7. The method according to claim 1, wherein the green compact for electrodes and the green compact for diffusion are Cr, W, Mo, Ta, Nb, Be, and high melting point metal.
One or a mixture of two or more of Hf, Ir, Pt, Zr, Ti, Te, Si, Rh and Ru, or a compound thereof, and a highly conductive metal made of Cu, Ag or Au, or mainly A method of manufacturing a base material for a vacuum valve, wherein the support member layer is made of an alloy with a highly conductive metal described above, and the support member layer is made of a highly conductive metal or an alloy containing a highly conductive metal. 8. The method for manufacturing a base material of a vacuum valve according to claim 1, wherein the green compact for an electrode is Cr, W, Mo, Ta, Nb, Be, Hf, I as a refractory metal.
1 of r, Pt, Zr, Ti, Te, Si, Rh and Ru
The diffusion compact is composed of a composite metal containing 35 to 65% by weight of a total of two or more kinds and 35 to 65% by weight of Cu as a highly conductive metal, and the green compact for diffusion is Cr, W, M as a high melting point metal.
One or two or more of o and Ta are made of a composite metal containing a total amount of 80 to 97% by weight and a highly conductive metal of 3 to 20% by weight of Cu, and the support member layer is made of Cr, Ag, W,
V, Nb, Mo, Ta, Zr, Si, Be, Co and F
e or one or two or more kinds of e and 4% by weight or less and Cu,
A method for producing a base material of a vacuum valve made of an alloy with Ag or Au. 9. The method for manufacturing a base material of a vacuum valve according to claim 1, wherein the base material according to the manufacturing method has a 0.2% proof stress of 10 kg / mm ₂ or more and a specific resistance of 2.2. 8μ
A method for manufacturing a base material of a vacuum valve, wherein the base material is not more than Ωcm.