JPS61142620A - Vacuum breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vacuum breaker, and more particularly, to a vacuum breaker that generates a magnetic field in the axial direction of the electrodes with respect to a pair of electrode parts that can be brought into and out of contact with each other. be.

[Conventional technology]

FIG. 9 shows, for example, a magnetic field (hereinafter referred to as longitudinal magnetic field) in the axial direction of the electrode part shown in Japanese Patent Publication No. 45-14607.
In Figure 1, 0η is a fixed contact part, @ is a container made of an insulating material, (to) is an arc shield for depositing metal vapor, and 0 !9I/'i Fixed side current terminal, (To) is the drive coil, (2) is the bellows, @ is the movable side current terminal, (To) is the fixed end plate, ■ is the movable end plate, (B) indicates the vacuum chamber, 2) indicates the lead wire, and the fixed and movable end plates (to)
The vacuum is maintained by a ring, a container, and a bellows.

FIG. 10 is a diagram showing the electrode structure of a conventional vertical magnetic field type vacuum breaker disclosed, for example, in Japanese Patent Publication No. 54-22818. In the figure, - is a conductive rod, +52 is a coil electrode, and 1- The main pole is provided so as to overlap the lower side of the coil electrode canno.

It is generally known that in a vacuum breaker, if the arc generated when the circuit is broken is magnetically driven, the breaking capacity will increase, and the wear and tear of the contacts will be reduced and uniform.
Various driving methods have already been proposed. The above-mentioned conventional example is a method in which magnetism is applied in parallel to the arc. For example, in the one shown in Japanese Patent Publication No. 14607/1983 shown in Fig. 9, the drive coil (to) connects the lead wire to It is connected to the fixed contact part 6p through the circuit '1 flow 1 is connected to the terminal (to), the coil (to), the lead wire -1 fixed liquid point part 0
υ flows in the direction of the arrow through the movable contact portion (2) and the terminal (to), and magnetic flux Φ is generated near the contact in the vacuum chamber (b) in the direction of the arrow.

Also, for example, in the one shown in Sukyu VF322818, shown in Figure 1θ, the current path enters the mounting base (58a) of the coil electrode 6 from the conductive rod (2), and then connects to the tip of each arcuate portion (51). Enter the main electrode-barrel through the protrusion (5gd). Therefore, the current flowing through the coil electrode section passes through each arm section (5Bb) and flows through the arc section (52c), which is generally equivalent to one turn of a loop current. The magnetic field of the turn appears as an axial magnetic field on the main electrode surface.

[Problem that the invention seeks to solve]

In the former type of conventional vertical magnetic field type vacuum breaker as mentioned above, it is necessary to provide a coil part outside the vacuum breaker, so the shape of the vacuum breaker becomes large and the coil diameter becomes large. Therefore, there was a problem in that the number of turns of the coil had to be increased in order to obtain the necessary magnetic field. Moreover, in the latter case, the electrode structure is complicated, the number of parts increases, and the number of brazed parts increases. In addition, there was a problem that the mechanical strength was low because there were many spaces.

This invention was made to solve the above-mentioned problems, and it is an object of the present invention to provide a vacuum breaker having a small number of parts and having a vertical magnetic field electrode with high strength.

[Means for solving problems]

The vacuum breaker according to the present invention has a contact current-carrying layer for switching circuits and a current path layer for generating a magnetic field in its electrodes, and the current path layer has an insulating material or a material with high electrical resistance inside. The contact current-carrying layer and the current path layer are separated by the current-limiting part except for several electrically conductive parts, and are integrated by powder metallurgy or melting. It is characterized by being molded.

[Effect]

According to the present invention, a vacuum breaker that can be used in ffi improves the breaker performance, is inexpensive, and has a contact current-carrying layer, a current path layer, and a current limiting part formed in one body to generate a vertical magnetic field in its electrode part. Manufactured in a small size with high mechanical strength? What to do0 [Embodiments of the invention] Examples of the invention will be described below.

(Example 1) Fig. 1 is a cross-sectional view showing one embodiment of the present invention, in which ill is a contact/separation conductive layer that connects and separates from the opposing electrode when opening/closing the T-path, and (2) is an insulating layer. It is a high-resistance material made of a metal or a material with high electrical resistance, and the part (2a) thereof is a part that restricts the current path for generating a magnetic field parallel to the electrode. The high-resistance material (2) is separated from the contact current-carrying layer il+ and the current path layer (3) except for several cutout portions, that is, layer connection portions (3c)'i5 around the periphery. A current path layer (3) for generating a magnetic field is connected to a conductive rod (not shown) and a current collecting portion (3) from a soldered portion at its center (4).
a) to the outer circumferential part (8b), and the layer connection part (3
C) is connected to the contact current-carrying layer.

FIG. 2 shows the manufacturing process of the electrode shown in FIG. 1. 9,151 is a contact conductive layer +11 and a current path layer (3
) indicates the mixture of copper powder and chromium powder, the weight ratio of copper powder and chromium powder is 75:
25yk! It is time mixed.

On the other hand, (7) is a high resistance bar made of 5US804 etc.
(8) shows a high-resistance part for current path restriction obtained by completely machining this bar (7), and (9) shows how the electrode is formed. Approximately half of the mixed powder prepared earlier is After filling the mold of the forming press, the part (8) is inserted into the mold, and finally the remaining mixed powder is filled into the mold and molded at a pressure of 10 tons per unit area.

Next, the molded body thus obtained was placed in a hydrogen atmosphere for 10
Sintering at 50°C (101°C) to obtain an electrode blank.

Then, this blank plate was machined using a lathe to obtain an electrode, which became the electrode shown in Figure 1.

(Example 2) Figure 8 shows another manufacturing process for obtaining the electrode of the present invention, in which (5) shows the amount of copper powder and chromium powder that are the materials forming the contact conductive layer fi+; (6) shows a mixture of copper powder and chromium powder, and the weight ratio of copper powder and chromium powder is 75.
:25 and mixed in a ball mill for 2 hours. On the other hand, as shown in Figure 0, ceramic insulators are created by firing alumina ceramic as an insulator that limits the current path.
Prepare. First, prepare copper powder A3 as the material for forming the entire current path layer (3). As shown in Forming C (9), a mold is first filled with copper powder (2), inserted into the ceramic insulator with the current path restricting part facing down, and temporarily formed at 8.8 tons per unit area. Next, take out only the upper punch of the press, fill it with the copper chromium mixed powder prepared in step 6), and perform molding at 10 tons per unit area.

(Example 8) Figure 4 shows other manufacturing steps for obtaining the electrode of the present invention.The main steps are the same as those in Example 1), and the difference is that the current path is limited. As an insulator, we first prepared a S[Ta205 plate 041 with a thickness of 2H, press-molded this to obtain a blank plate shown in CIFA, and then thermally sprayed alumina on this blank plate as shown by H. .

(Example 4) FIG. 5 shows the manufacturing process for obtaining the electrode of the present invention. (6) shows the contact conductive layer 11) and the current path layer (
3) Intoxication of copper powder and tungsten powder, which are the materials for total formation, (6) shows the mixture of copper powder and tungsten powder,
Copper powder and tungsten powder were mixed in a weight ratio of 10:9G in a ball mill for 2 hours. On the other hand, (6)
As shown in FIG. 1, an alumina ceramic similar to that used in Example 2, which was entirely coated with molybdenum-manganese metallization, was prepared as an insulator for restricting the current path. Molding #-j (As shown in 91, one part of the copper-tungsten mixed powder is filled into the molding die, then the metalized ceramic is inserted, and the remaining copper-tungsten powder is filled to form a mold of 1 ton per unit area. Molding is performed under pressure.Next, the molded product thus obtained is heated to 1000°C in a vacuum.
Temporarily sintered (lO), then placed a copper lump on the calcined product,
Copper is infiltrated at 1250°C in a hydrogen atmosphere to form an electrode material.

In this case, the final copper-tungsten weight ratio r/'i25 is 5.

(Example 5) Figure 6 shows another manufacturing process for obtaining the electrode of the present invention, which is almost the same process as Example 2.The difference is that the alumina ceramic is In addition, a part QllK with only cutouts for the path and the contact part,
One part of the copper chromium mixed powder is filled into a press mold, all the ceramic parts are inserted, and the first forming process is pre-sintered at 3.3 tons per unit area.Then, the upper punch rod is removed and the remaining copper is removed. - It has a secondary molding screen in which a part of the mixed powder from the chromium powder is filled into a mold, the ceramic part a2 is inserted, and the remaining mixed powder is filled thereon and molded at 10 tons per unit area.

(Example 6) Figure 7 shows a high-resistance material part machined from a bar of 5US304, and the method of manufacturing an electrode using this is the same as that shown in Figure 8. be. The connection point with (Example 1) is +11 on the contact current-carrying layer side as an electrode.
A wall (
2) 1t- is provided.

In the vacuum breaker electrode constructed as described above, as shown in Fig. 1, the current flows through the central part (4), which is brazed to the conductive rod, to the current extraction part (3a), and then to the outer circumference. (3b) The current flows in the direction of the arrow and generates a magnetic field Φ in the direction shown in the figure. ), and the electrical circuit is opened and closed by connecting and separating the electrode portion facing the contact current-carrying layer (1).

In addition, what is shown in FIG. 8 #-i (Example 1) (FIG. 1)
FIG. 2 is a perspective view of the electrode, which is exploded to make the structure of the electrode easier to understand. The actual one is (1) 12+ ta in the diagram.
Since 11 is manufactured as one piece, it is difficult to divide it as shown in the figure. It should also be mentioned again that the conductive rod and the electrode are only brazed at the center (4).

In the above embodiment, copper powder, chromium powder, and tungsten powder are used as the materials for forming the contact electrode layer 111, but other contact materials to which so-called powder sintering methods such as sintering and impregnation methods can be applied may also be used. All can be applied to the present invention.

In addition, in the above (Example 4), the Fi current path part was also filled with copper-tungsten mixed powder and molded, but the contact current-carrying layer +11
Fill only the sides, and then pre-sinter the molded product in a vacuum. Then, when infiltrating copper in a hydrogen atmosphere, increase the amount of steel* and fill the excess copper into the current path layer (3). Electrodes can also be made using this method.

In addition, in the above embodiment, the current in the current path layer (3),
Although this is an example of dividing pItS, other numbers of divisions can be considered for the soil.

In addition, although the above embodiment mainly explained the powder metallurgy method, it is also important to ensure that the insulating material or material with high electrical resistance that constitutes the current limiting part (2) does not react with the melted contact material at all, or that the anti-F5 If the amount of occurrence is very small, a casting method using melting is also effective, and produces the same effects as the above embodiments.

〔Effect of the invention〕

As described above, according to the present invention, the electrode is made of an insulator or a material with high electrical resistance that limits the path through the contact current-carrying layer and separates the contact current-carrying layer from the current path except for a few notches. Second, since the electrode is manufactured in one piece by a so-called powder sintering method, it can be manufactured at low cost, has a small number of parts, has few brazed parts, and does not require a complicated manufacturing process.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing an electrode of a vacuum breaker according to an embodiment of the present invention, FIGS.
The figure is an exploded perspective view showing the entire electrode structure of FIG. 1, and FIG. 9 and FIG. 1θ are views showing a conventional vacuum breaker and electrode structure, respectively. In the figure, (II is a contact conductive layer, (2) is a high-resistance material (current limiting part), and (:11 is a current path layer. In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] (1) In a device that opens and closes an electric circuit using a pair of electrodes that are housed in a vacuum container and can be freely moved toward and away from each other and each is attached to a conductive rod, the electric circuit is opened and closed on the opposite electrode surface side of at least one of the electrodes. It has a current path layer for generating a magnetic field parallel to the electrode axis on the mounting surface side with the conductive bar, and the current path layer has an insulating material or an electrically resistive material inside it. The contact current-carrying layer and the current path layer are separated by the current-limiting part except for several electrically conductive parts, and the contact current-carrying layer and the current path layer are separated by the current-limiting part except for a few electrically conductive parts, and are made of a mixed powder sintered or infiltrated. 1. A vacuum breaker characterized in that the electrode is integrally formed by a powder metallurgy method consisting of a molten alloy casting method, or a melting method consisting of a molten alloy casting method. (2) The vacuum breaker according to claim 1, wherein the current limiting portion is embedded within the contact conductive layer. (3) The vacuum breaker according to claim 1 or 2, wherein the current path layer is composed of a plurality of layers.