JPH0777100B2 - Method for manufacturing electrode of vacuum interrupter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for manufacturing a vacuum interrupter electrode including an arc portion and a contact portion.

B. Outline of the Invention The present invention is to integrally manufacture a vacuum interrupter electrode composed of an arc portion and a contact portion without brazing or the like. Therefore, a metal powder layer serving as the arc portion and a metal powder serving as the contact portion are formed. The layers and the cups made of infiltrant are respectively placed and overlapped, and the mixture is heated and held to make the metal powder layer a sintered body, and the cup made of the infiltrant is melted and infiltrated into the sintered body. The arc part and the contact part are integrated.

In addition, when the separately formed sintered bodies for the arc portion and the contact portion are housed in the cup made of the infiltrant, the infiltrant is infiltrated into the sintered body by heating them together. Thus, the arc portion and the contact portion are integrated.

C. Conventional Technology The electrodes of the vacuum interrupter have large current interruption characteristics,
Various characteristics such as low breaking current value characteristics, high withstand voltage value characteristics, low contact resistance characteristics, low welding force characteristics, and low wear characteristics are required.

At present, Cu-Cr alloys (Cu-Cr, Cu-Mo, Cu-Mo-Cr) are used as electrode materials, because they practically almost satisfy the above-mentioned characteristics.

Then, in order to further improve the breaking performance, as shown in FIGS. 5 and 6, the electrode 1 is made into two parts, that is, a central contact part 2 and an arc part (arc diffusion part) 3 around it, and There is provided an electrode in which a material suitable for each function is selected as a portion and both are joined by brazing or the like. In the figure, 4 is a brazing material.

D. Problems to be Solved by the Invention In the two-part structure electrode having the above structure, since it has a two-region structure by joining such as brazing, a minute gap 5 is formed at the boundary surface of the electrode surface, and The brazing material 4 may exude from the gap 5 portion.

Such a gap 5 or the like causes deterioration in withstand voltage characteristics, and also hinders the diffusion and movement of the arc column generated at the contact portion 2 to the arc portion 3, that is, the arc easily stops and the cutoff performance is deteriorated.

In addition, the cost is increased because the members having different shapes are made of two different materials.

Furthermore, since two different kinds of materials are joined, the cost is increased.

E. Means for Solving the Problems In order to solve the above problems, the present invention provides a method of manufacturing an electrode of a vacuum interrupter, which comprises an arc portion and a contact portion at a central portion thereof. A first metal powder layer made of at least one kind of metal powder to be an arc portion is housed in the cup to form a temporary arc portion, and at least one kind to be a contact portion is provided in the second cup made of the infiltrant. The second contact layer is formed by accommodating the second metal powder layer made of the metal powder, the temporary contact section is placed on the temporary arc section, and the temporary arc section and the temporary contact are placed in a non-oxidizing atmosphere. Part is heated and maintained at a temperature equal to or lower than the melting point of the infiltrant to sinter the first metal powder layer and the second metal powder layer into a porous sintered body. The infiltrant is melted in each sintered body by heating and maintaining the temperature above the melting point of the sintered body. It was soaked so that the arc part and the contact part were integrated.

Further, when the first metal powder sintered body and the second metal powder sintered body separately molded in the first cup and the second cup made of the infiltrant are respectively housed as the temporary arc portion and the temporary contact portion, , Superimposing these, in the non-oxidizing atmosphere, the temporary arc portion,
The temporary contact portion is heated and maintained at a temperature higher than the melting point of the infiltrant and lower than the melting point of the sintered body to infiltrate the infiltrant into each sintered body and integrate the arc portion and the contact portion. I did so.

F. Action Since the infiltrant between the porous sintered bodies is melted and infiltrated into both sintered bodies, and both are integrally connected, an electrode having an arc portion and a contact portion can be obtained.

G. Examples (1) Example 1 FIG. 1 shows a schematic process of one example of an electrode manufacturing method according to the present invention.

A first cup 12 made of an infiltrant made of Cr powder, Mo powder, or a mixed powder of Cr and Mo, which will be the arc portion, as the first powder metal layer 11.
It is filled in and the temporary arc part 13 is formed.

On the other hand, the Cu, Cr mixed powder or the Mo, Cu mixed powder or the Cr, Mo, Cu mixed powder to be the contact portion is filled as the second powder metal layer 14 into the second cup 15 made of the infiltrant to make a temporary contact. Form part 16.

The above-mentioned compositions of the first metal powder layer 11 which becomes the arc portion and the second metal powder layer 14 which becomes the contact portion are merely examples.
Various other compositions are possible. In short, a material having a low contact resistance may be used for the joint portion, and a material having a large current breaking performance may be used for the arc portion.

Further, as the infiltrant as the material of the first cup 12 and the second cup 15, Cu, Cu alloy, Ag, Ag alloy or the like is adopted.
In this embodiment, it is assumed that Cu is used.

The temporary contact portion 16 is placed on the temporary arc portion 13 obtained as described above, and the temporary contact portion 16 is placed in the vacuum furnace 17 that creates a non-oxidizing atmosphere.

Then, for example, in a vacuum of about 5 × 1.333 mPa (5 × 10 ⁻⁵ mmHg), a temperature of 1083 ° C. or lower (for example, 10
The mixture is heated at 00 ° C.) for 10 to 60 minutes to diffuse and fuse the metal powders to form the first and second powder metal layers 11 and 14 as porous sintered bodies 11a and 14a, respectively.

Then, heating is performed at a temperature (for example, 1100 ° C.) that is equal to or higher than the melting point of Cu that is the infiltrant and is equal to or lower than the melting point of the metal powder for about 10 minutes to infiltrate Cu into the voids of the sintered bodies 11a and 14a. Between the sintered body 14a serving as the contact portion and the sintered body 11a serving as the arc portion, the second
Since the bottom of the cup 15 is present, Cu in this portion is infiltrated into both sides at the boundary between the sintered bodies 11a and 14a, and the sintered body 11a
By combining a and 14a, an electrode 18 in which the arc portion 11b and the contact portion 14b are integrated is obtained.

In the above method, when the arc portion 11b has a spiral shape, a spiral cup is used as the first cup 12 for housing the first powder metal layer 11, as shown in FIG.

As the non-oxidizing atmosphere in which the infiltration work is performed, a non-oxidizing atmosphere such as argon gas or nitrogen gas is adopted in addition to the above-mentioned vacuum atmosphere.

(2) Embodiment 2 FIG. 3 shows schematic steps of an electrode manufacturing method according to another embodiment of the present invention.

In this embodiment, separately formed pressure-molded bodies 11s and 14s are used as the powder metal layer housed in the cup made of the infiltration material.

The pressure-molded bodies 11s and 14s are produced by charging the powder metal into a mold mounted on the pressure-molding machine and then activating the pressure-molding machine to perform compression-pressure molding at a predetermined pressure. To be

The pressure molded body 11s for the arc portion and the pressure molded body 14s for the contact portion thus obtained are housed in the first cup 12 and the second cup 15 made of the infiltrant, respectively. Sintered and infiltrated in the same manner as in the example, arc portion 11b, contact portion
An electrode 18 with integrated 14b is obtained.

(3) Example 3 A first powder metal sintered body 11a and a second powder metal sintered body 14a to be housed in the cups 12 and 15 were separately prepared, and these were respectively prepared as shown in FIG. 4, for example. They are housed in the first and second cups 12 and 15 made of an infiltrant, and they are overlapped as a temporary arc part 13 and a temporary contact part 16, and these are put in a vacuum furnace at a predetermined temperature (for example, 1100 ° C). It is heated and held for a predetermined time (for example, about 10 minutes).

The first and second cups 12 and 15 are melted, the infiltrant is infiltrated into the first and second powder metal sintered bodies 11a and 14a, and the arc portion 11b and the contact portion 14b.
Thus, the electrode 18 integrated with and is obtained.

H. Effect of the Invention According to the method for manufacturing a vacuum interrupter electrode according to the present invention, the arc portion and the contact portion are made into a sintered body, which are housed in a cup made of an infiltrant and stacked, and heated in this state. Since the infiltrant is infiltrated into both sintered bodies, an integrated electrode having no boundary between the arc portion and the contact portion can be obtained, and its withstand voltage characteristic and cutoff characteristic are improved. Moreover, since the integrated electrode can be obtained in a series of steps, it is possible to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a schematic process drawing of an embodiment of the present invention, FIG. 2 is a plan view of an example of an arc portion cup, FIG. 3 is a schematic process drawing of another embodiment, and FIG. 4 is still another embodiment. In the example, a cross-sectional view of a state in which the temporary arc portion and the temporary contact portion are overlapped, FIG. 5 and FIG. 6 are a vertical cross-sectional view and a plan view of a conventional electrode. In the drawing, 11 is a first powder metal layer, 12 is a first cup, 13 is a temporary arc part, 14 is a second powder metal layer, 15 is a second cup, 16 is a temporary contact part, 17 is a vacuum furnace, 18 is a It is an electrode.

Claims (4)

[Claims] 1. A method of manufacturing an electrode of a vacuum interrupter comprising an arc portion and a contact portion at a central portion thereof, wherein at least one kind of metal powder to be an arc portion is provided in a first cup made of an infiltrant. The first metal powder layer is formed to form the temporary arc portion, and the second metal powder layer made of at least one kind of metal powder to be the contact portion is stored in the second cup made of the infiltrant. Form a contact part, place the temporary contact part on the temporary arc part, and heat and hold the temporary arc part and the temporary contact part at a temperature lower than the melting point of the infiltrant in a non-oxidizing atmosphere. Then, the first metal powder layer and the second metal powder layer are sintered to form a porous sintered body, and further heated and held at a temperature not lower than the melting point of the infiltrant and not higher than the melting point of the sintered body. The infiltration material is infiltrated into each sintered body to integrate the arc portion and the contact portion. Method of manufacturing electrode of vacuum interrupter. 2. The electrode of the vacuum interrupter according to claim 1, wherein the first metal powder layer and the second metal powder layer are filled in the first cup and the second cup without pressure, respectively. Production method. 3. The first metal powder layer and the second metal powder layer respectively housed in a first cup and a second cup made of an infiltrant are respectively pressure-molded. Of manufacturing electrodes of vacuum interrupter of. 4. A method of manufacturing an electrode of a vacuum interrupter comprising an arc portion and a contact portion at a central portion thereof, wherein at least one kind of metal powder to be an arc portion is provided in a first cup made of an infiltrant. The first metal powder sintered body formed by sintering is housed to form a temporary arc portion, and at least one kind of metal powder to be a contact portion is sintered in a second cup made of an infiltrant. The second powder metal sintered body is housed to form a temporary contact portion, the temporary contact portion is placed on the temporary arc portion, and the temporary arc portion and the temporary contact portion are placed in a non-oxidizing atmosphere. The arc portion and the contact portion are integrated by heating and holding the infiltrant into each sintered body by heating and holding at a temperature higher than the melting point of the infiltrant and lower than the melting points of the first and second powder metal sintered bodies. A method of manufacturing an electrode of a vacuum interrupter, comprising: