JPH02106831A - Manufacture of electrode for vacuum interruptor - Google Patents

Abstract

PURPOSE:To accurately form an electrode for a vacuum interruptor, with plural through-grooves, in a short time by grinding the electrode through a water jet method using the abrasive material of metal powder not including oxide and having the particle size of 100 mesh or less. CONSTITUTION:An electrode for a vacuum interruptor, with plural through- grooves is manufactured by a water jet method using the abrasive of metal powder not including oxide and having the particle size of 100 mesh or less, and also applying high water pressure. With this arrangement, it is possible to obtain such an electrode as harming the performance of the vacuum interruptor and simplify the grooving without being affected by the electrode material, groove shape and the groove position, thus improving the productivity.

Description

[Detailed Description of the Invention] A. Industrial Application Field The present invention relates to a method of manufacturing an electrode for a vacuum interrupter.
In particular, the present invention relates to a method of forming a plurality of grooves in an electrode material using a water jet method.

B1 Summary of the Invention The present invention provides an abrasive material that does not contain oxides and has a particle size of 10
This is a method for manufacturing an electrode for a vacuum interrupter in which a plurality of grooves can be easily formed in an electrode material by a water jet method using metal powder with a mesh size of 0 or less.

C1 Prior Art Conventionally, the electrodes of vacuum incretors have one straight groove and one circular arc groove in order to perform arc control, magnetic field control, current control, etc. and improve the breaking performance.

It is common practice to provide various planting grooves such as slanted grooves.

As an example of an electrode of a vacuum interrupter equipped with such grooves, an electrode having a plurality of spiral grooves (arc grooves) as shown in FIGS. 5 and 6 is known.

That is, this electrode is provided at the end of the leat rod 3 with an arc portion 2 around a contact portion l protruding from the center. A plurality of spiral grooves 4 are provided in the arc portion 2, and an arc petal 5 is formed between each groove 4.

In the electrode formed in this way, the arc 6 generated at the contact part 1 at the time of interruption moves outward on the arc plane and 5 along the spiral groove 4, and during the movement, it reaches the current zero point and is interrupted. This is the end of the process.

Therefore, since the arc is moving, there is no concentration or stagnation, and as a result, the breaking performance can be improved.

D1 Problems to be Solved by the Invention By the way, as means for forming the grooves 4 on the electrodes as described above, generally the following methods are considered: (1) band saw, (2) end mill, (2) wire cutting, and (2) laser machining.

(1) However, the electrodes of the vacuum incretor are made of copper (Cu).
), the pressurizing means described in ■ and ■ above will cause oxidation due to the heat during processing, which will have a negative effect on current interrupting performance, withstand voltage characteristics, etc. Measures are being taken.

(2) Recently, chromium (Cr) has been used as an electrode material to improve current cutoff performance and withstand voltage performance.

Molybdenum (Mo), tungsten (W), iron (Pc)
Addition of metals such as When grooves are formed on electrode materials containing such metals using the processing methods described in (1) and (2) above, there are problems such as (a) the processing takes a long time, and (b) the cutting blade is severely worn out. However, the electrode productivity is poor and it is not practical.

(3) Furthermore, although electrode materials formed by sintering powder are generally used, cutting oil cannot be used when forming grooves in this type of electrode materials. In other words, since pores remain in the electrode material, oil enters into the pores, and this oil remains even after the vacuum interrupter is constructed, so that it does not adversely affect the interrupting performance or the like.

Therefore, in the above-mentioned processing methods (1) and (2), processing must be performed without using cutting oil, which poses problems such as (a) long processing time, and (b) severe wear and tear on the cutting blade. It is unproductive and impractical.

(4) In addition to the above-mentioned problems caused by the electrode materials, the following problems arise in processing using the aforementioned bunt saws and end mills.

In other words, with the band saw described in (2), the finish of the machined surface is poor and burr is generated, and since this burr is formed on the electrode surface exposed to the arc, it is necessary to remove it. , productivity is poor.

In addition, in the case of the end mill (3), although the occurrence of burrs was small, it was not possible to form narrow grooves, and there was a limit to the range of applicability of groove processing.

(5) As explained below, conventional electrode groove processing methods known for boat fishing have not been manufactured due to problems caused by the electrode materials and processing methods. At present, it is difficult to improve the properties and new processing methods are expected.

Means for Solving Problem E1 As a result of considering the problems with the conventional processing means mentioned above, we focused on the water jet method, which involves processing such as cutting by applying high water pressure together with an abrasive material.

In other words, this processing method ■No cutting oil required.

■Cutting width can be changed freely depending on the nozzle diameter.

■Cutting groove shape can be made into any shape.

■Water used can be easily removed.

■The cut is clean and no cracks occur.

■Since high water pressure is used, the cut surface will not be altered.

We focused on such points.

Although the water jet method has the above-mentioned advantages, when the object to be processed is an electrode material for a vacuum ink cleaner, selection of the abrasive is important.

That is, since the water jet method uses an abrasive material, a portion of this abrasive material remains on the electrode surface, and it is expected that this will not adversely affect the performance of the vacuum interrupter.

As a result of repeated experiments, the inventor determined that the conditions for the abrasive material were: ■A metal that does not contain oxides.

■ Moreover, the powder has a particle size of 100 mesh or less.

We have discovered that if this is the case, it is unlikely to remain on the surface of the electrode material, and even if it remains, it will not adversely affect the withstand voltage characteristics of the electrode, and furthermore, it can be processed with stable accuracy without being affected by the electrode material.

The present invention has been achieved based on the above-mentioned facts, and the key point is to use a water jet that processes by applying high water pressure together with an abrasive material made of metal powder that does not contain oxides and has a particle size of 00 mesh or less. According to the present invention, an electrode for a vacuum incrector having a plurality of through grooves is manufactured by a method.

In addition, as the electrode of the vacuum incluctor having a plurality of through grooves, for example, a magnetic rotation drive type electrode having a circular arc Wlt (spiral M), a straight groove, etc., which is known from Japanese Patent Application Laid-Open No. 62-76225, etc. This includes a vertical magnetic field application type electrode having a vertical magnetic field, a cup (contrate) type electrode having an inclined groove, and an electrode having a through groove.

Further, the positions of the grooves in the electrode correspond to grooves located in parts exposed to the arc generated at the time of interruption, and in parts where there is a risk of such occurrence.

On the other hand, metal powder as an abrasive is aluminum (Af
2), silicon (Si), iron (Fe), chromium (Cr)
This applies to metals such as .

Furthermore, the conditions for the water jet are as follows: feed rate: I50zm/min or less pressure crab 1000-4000 kg/c11' nozzle diameter 1-5 m, tn (select one that is the same as the groove width) desirable.

Since the through-groove is formed in the electrode material by the water jet method, which is processed by applying high water pressure with a 20-acting abrasive material, it is possible to obtain an electrode that will not have a negative effect on the performance of the vacuum interrupter, and moreover, the electrode material Grooving can be easily performed without being affected by the groove shape and groove position, and productivity is significantly improved.

G. Example The present invention will be explained below based on one embodiment.

FIG. 1 shows a schematic overall view of the processing equipment, in which 11 is a filter, 12 is an ultra-high pressure pump, 13 is a cutting head, 14 is a work table, 15 is an abrasive tank, 1
6 shows the air for controlling abrasive material mixing, 17 shows the air for controlling water and water, and 18 shows the beam water equipment.Each part is connected with piping, and "water" flows as shown by the arrow in the figure. It is.

An electrode material 21 is fixedly placed on the work table 14, and a predetermined groove is formed in the electrode material 21 by a water jet stream A ejected from a nozzle 22 at the lower end of the cutting head I4. .

The conditions at this time are as follows.

■The abrasive material is aluminum powder with a particle size of 80 mesh or less and containing no oxides.

■The machining conditions are: feed speed near 0 mm, partial pressure 2500 kg/am” nozzle diameter: 2
mg (same as groove width) ■Electrode material: Cu-25Fe-25Cr formed by infiltrating copper into a skeleton made of powdered iron and chromium.
weight%) of composite metals.

Shape: Outer diameter is 80mm, thickness is 121m, diameter of spiral groove inner end is 25cm, number of spiral grooves is 12, groove width is 211M.

Under the above conditions, spiral grooves were formed on the electrode material, and the arc portion with the spiral grooves (see Figures 5 and 6 above)
(see figure) was assembled into a vacuum ink club shown in FIG. 2.

That is, in the center of the arc part 2 formed by the double water-on-esotho method, there is a ring having a composition of Cu-Mo-Cr and having an outer diameter of 40rnrn, an inner diameter of 25U, and a thickness of 3mrp. The fixed electrode 10a and the movable electrode 10b were constructed by joining the contact portions 1 of the shape.

These pair of electrodes 10a and lOb are each fixed on a lead rod 3.
a, joined to the inner end of the movable lead rod 3b and arranged facing each other;
In addition, the vacuum interrupter was constructed by secretly penetrating the vacuum container 31 provided with an insulating section (the movable lead rod 3b was inserted through the hollow tube 32).

In addition, in the figure, 33, 34, and 35 are shields, respectively.

In the vacuum incluctor constructed in this way, the withstand voltage characteristics and current interrupting performance after assembly were investigated.

For comparison, the particle size of the abrasive containing oxide was 8.
A similar test was conducted on a vacuum incretor equipped with an arc section grooved using zero-mesh garnet powder (other conditions being the same).

Figure 3 shows the measurement results (relative values) of withstand voltage characteristics, and the results for the aluminum abrasive material of the present invention (○-○ line, 1
It can be seen that the water jet method (×-X-ray, 60%) using metal powder of garnet or less has poorer characteristics than that of the metal powder (00%).

In addition, Figure 4 shows the measurement results (relative values) of current interrupting performance.
The result of the aluminum abrasive material of the present invention (○
It can be seen that garnet (X-X rays, 80%) has poorer characteristics than garnet (x-X rays, 80%).

From these results, it was found that the manufacturing method according to the present invention using a metal that does not contain oxides as the abrasive material can contribute to improving the performance of a vacuum incluctor.

H3 Effects of the Invention As described above, according to the manufacturing method of the present invention, since the abrasive does not contain oxides and is processed with a grain size of 100 mesh, it is possible to produce an electrode for a vacuum incretor equipped with a through groove in a short time. It can be processed and formed with high precision, and productivity can be significantly improved.

Moreover, the composition and form of the electrode material (alloy, sintered).

Since the process can be performed in the same way in any case, regardless of the difference in infiltration (infiltration), groove position, groove shape, etc., productivity can be significantly improved and inexpensive electrodes can be used. Therefore, it is possible to provide an inexpensive vacuum ink cleaner.

Furthermore, the abrasive material does not have any negative effect on the performance of the vacuum ink cleaner and does not contain any oxides, so even if some of the abrasive material remains on the electrode surface, the performance will not deteriorate and the production process will be improved. The synergistic effect with the improved performance makes it possible to provide a high-performance vacuum interrupter at a low cost.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of processing equipment used in the manufacturing method of the present invention,
Figure 2 is a cross-sectional view of the vacuum incrector, Figure 3 is a characteristic diagram of the measurement results of withstand voltage characteristics, Figure 4 is a characteristic diagram of the measurement results of current interrupting performance, and Figure 5 is a plane view of the electrode with spiral grooves. 6 is a sectional view taken along line BB in FIG. 5. ■... Contact part, 2... Arc part, 3, 3a, 3b.
...Lead rod, 4...Spiral groove, 5...Arc petal, 10a...Fixed electrode, lOb...Movable electrode,
12...Ultra high pressure pump, 13...Cutting head, 14...Work table, 15...Abrasive tank, I6...Air for controlling abrasive mixture, I7...Air for water jet control , 21... electrode material, 22...
··nozzle. 1. Explanatory diagram of the processing equipment for the water shedding method. 2. Cross-sectional view of the vacuum interrupter. 3. Characteristic diagram of the measurement results of withstand voltage characteristics. -- Garnet Aluminum abrasive Figure 5 Plan view of electrode

Claims (1)

[Claims] (1) Manufacture of an electrode for a vacuum interrupter, characterized in that through-grooves are formed in the electrode material by a water jet method using metal powder with a particle size of 100 mesh or less and without containing oxides in the abrasive material. Method.