JPS6074316A - Vacuum interrupter - 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 Field of the Invention The present invention relates to a vacuum interrupter, and more particularly to a so-called vertical magnetic field type vacuum interrupter that is equipped with means for generating an axial magnetic field (a vertical magnetic field) parallel to an arc.

Conventional vertical magnetic field type vacuum incretors apply a vertical magnetic field parallel to the arc to disperse the arc over the entire electrode surface, resulting in local concentration of the arc. Prevents excessive melting of the electrode! A pair of electrode rods are introduced into the vacuum container so that they can be moved relatively toward and away from each other, and an arc diffusion part and a contact part are installed at the inner end of each electrode rod. and a coil as a means for generating a longitudinal magnetic field.
As described in Japanese Patent Publication No. 3045, etc., a cylinder provided outside the vacuum container, or Japanese Patent Publication No. 53-41793, Japanese Patent Publication No. 54-22813, or Japanese Patent Application Laid-Open No. 1987-56
As described in Japanese Utility Model Application Publication No. 130037, etc., there is a It consists of a hole provided around the outer periphery of the electrode.

By the way, the following properties (1) to (V) are required for the electrode material of the vacuum interrupter.

(1) High current cutting ability (11) High withstand voltage (IIL) Low wear and tear (LV) Small current cutting value (■) Low contact resistance (VIL Low welding force) However, in the electrodes of conventional vertical magnetic field type vacuum interrupters, for example, shear arc diffusion parts made of a composite metal of austenitic stainless steel and copper (Cu) disclosed in Japanese Patent Laid-Open No. 53-21777 are used. At the same time, the contact portion is made of Cu as described in Japanese Patent Publication No. 41-12131,
It is known to be formed from a Cu-B1 alloy (for example, a Cu-0,5B1 alloy) containing a small amount of bismanu (Bi). However, such electrodes can suppress the generation of eddy currents due to longitudinal magnetic fields, have large current cutting ability,
Although it has excellent welding resistance and contact resistance, it is not suitable for high voltage applications.

In addition, for high voltage applications, the austenitic stainless steel/
The shear arc diffusion part is formed of a composite metal of steel and Cu, and the contact part is made of a Cu-W alloy (e.g. 20Cu -80W alloy) is known.

However, this electrode has the disadvantage that it is difficult to cut off large currents such as fault currents.

On the other hand, in order to deal with the rise in current and pressure associated with recent system expansion,
There is a demand for an electrode that has both excellent current cutting ability and dielectric strength.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a vertical magnetic field vacuum interrupter equipped with electrodes capable of interrupting large currents and high voltages.

Structure of the Invention In order to achieve the above object, the present invention introduces a pair of electrode rods into a vacuum container so that they can approach and separate from each other freely, and an arc diffusion part and a contact part are provided at the inner end of each electrode rod. A vacuum interrogator comprising: a coil for applying an axial magnetic field parallel to the arc to the outside of the vacuum vessel or inside the vacuum vessel;
The arc diffusion part of each electrode is made of a composite metal made of 30 to 70% by weight of austenitic stainless steel and 30 to 70% by weight of copper, and the contact part is made of 20 to 70% by weight of copper.
70% by weight, chromium 5-70% by weight and molybde 75
It is made of a composite metal with a weight of ~70%.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a vacuum ink tank showing an embodiment of the present invention. This vacuum ink box is positioned on the axis of a circular vacuum container, and a pair of electrode rods 2, 2 are placed relatively close to each other. A pair of electrodes 3゜3 in the shape of a hat-shaped disk is mechanically fixed to the inner end of each electrode rod 2 with an insulating spacer interposed, and each electrode rod 2 and electrode 3 are connected as electrodes. The coils 4, 4 are disposed on the back of the electrode rod 3 and generate a vertical magnetic field by changing the axial current flowing through the electrode rod 2 (in the vertical direction in Fig. 1) into a loop current centered on the electrode rod 2. The structure is roughly connected with spots.

That is, the vacuum container 1 has two cylindrical insulating tubes 5, 5 made of glass or ceramics fixed to both ends.
Thin annular sealing fittings 6, 6. made of a-Ni-Co alloy, Fo-Ni alloy, or the like. . . . to form a single insulating cylinder, and both open ends thereof are connected to disk-shaped metal end plates 7, 7 through the other sealing fittings 6, 6.
Close the circle and place it under high vacuum (for example, 5 x 1
It is formed by evacuating to a pressure below 0-' Torr. The electrode rods 2 are introduced into the vacuum container 1 from the center of each metal end plate 7 so as to be able to approach and separate from each other while maintaining the airtightness of the vacuum container 1.

Note that one electrode rod 2 (upper in FIG. 1) is hermetically inserted into one metal end plate 7, and the other electrode rod 2 is connected to the vacuum vessel l through a metal bellows 8. The metal end plate 7 is inserted through the other metal end plate 7 so as to be movable in the axial direction while maintaining airtightness. Further, in FIG. 1, 9 and 10 are a shaft shield and a bellows shield, 1 is a main shield, and 12 is an auxiliary shield.

As shown in FIGS. 2 and 3, the inner end of each electrode rod 2 is made of a material with high conductivity such as Cu, and has a disc-like diameter suitably larger than the diameter of the electrode rod 2. a mounting base 4a, two arms 4b extending outward in the radial direction (left and right directions in FIG.
A branching type coil 4 consisting of a circular arc portion 4c curved in an arc shape in the same direction with the center at It is firmly fixed.

The coil 4 has a ring-shaped attachment part 14 a fitted to the outer periphery of the inner end of the electrode rod 2 by brazing, and an attachment part 14 a.
The coil reinforcement body 14 is brazed to the coil reinforcement body 14, which is made up of a plurality of support arms 14b extending radially outward from the outer periphery of the support arm 14b, and a ring-shaped support part 14c connecting the ends of each support arm 14b. It has been reinforced.

The coil reinforcing body 14 is made of a material having mechanical strength holes and low conductivity, such as stainless steel.

A circular recess 15 is provided on the other surface of the mounting base 4a of the coil 4, and the recess 15 is made of a material with mechanical strength and low conductivity, such as stainless steel or Inconel. An insulating spacer 16 formed into a short cylindrical shape is fixed by brazing through a small diameter flange 1.6 formed at one end thereof. The large diameter flange 16b formed at the other end of the insulating spacer 16 has this large diameter flange 16. An annular plate-shaped mounting base 17B having a diameter suitably larger than b and having a through hole of approximately the same diameter as the inner diameter of the insulating spacer 16 and a mounting base 17a from opposing positions on the outer periphery outward in the medial direction. Two arms 1 extending to
7b, and the arc portion 4 of the coil 4 from the end of each arm 17b.
A circular arc portion 17 curved in an arc shape with a radius of curvature approximately equal to that of C and an appropriate length in the same direction opposite to this. The auxiliary coil 17 is fixed by brazing via a retaining step 18 provided on one (lower side in FIG. 2) surface of the mounting base 17a. Then, the auxiliary coil 17 and the coil 4
This means that one end is fixed to the recess 19 provided at the end of each arcuate portion 17e of the auxiliary coil 17, and the other end is inserted into the through hole 21 provided at the end of each arcuate portion 4C of the coil 4. They are electrically connected via an axial current-carrying pin 20.

The electrode 3, which is formed to have approximately the same diameter as the coil 4, is connected to the auxiliary coil 17 by brazing through the four parts 22 provided at the center of the back surface, and is also connected to the mounting base 17 through the back surface. It is joined to each arm 17b and arc portion 17e by brazing. The electrode 3 has a circular recess 23 in the center of the opposing surface (upper surface in FIG. 2), and an arc diffusion section 3a formed in the shape of a hat-shaped disk that gradually becomes thinner as it approaches the periphery, and a flat circular recess 23 on the opposing surface. The concave portion 23 of the arc diffusion portion 3a is formed in the shape of a cap-shaped disk and has a contact surface of
The contact portion 3b is fixed to the contact portion 3b by brazing, and is provided in the shape of a cap-shaped disk as a whole.

The arc diffusion part 3a of the electrode 3 is made of austenitic stainless steel (for example, 5us304, 316L, etc.) 30
It is formed of a composite metal consisting of ~70M N% and Cu30-70% by weight. In addition, this composite metal is 4 to 30 4 trains (IACS de) + 30 kIf
Tensile strength of f/mt1 or more and 100-180Hv
(1 kg) of hardness.

In addition, the contact portion 3b contains Cu2O to 70% by weight, chromium (
Cr) 5-70iffi% and Molytubu y (M
o) Made of 5-70% by weight composite metal. Note that this composite metal has an electrical conductivity of 20 to 60% and a hardness of 120 to 180 HV (1 kg).

On the other hand, the composite metal forming the arc diffusion part 3a and the contact part 3
The composite metal forming b is manufactured in the same manner as above. Next, various clothing manufacturing methods will be explained using a composite metal forming the contact portion 3b as an example.

(1) For example, -100 mesh Cr powder and -100 mesh
A predetermined amount of Mo powder of mesh is mixed, and this mixed powder is placed in a container made of a material that does not react with Cr, No, and Cu (e.g., alumina), and 10 pieces of Cu are placed thereon. to-II Torr
), first heated at 1000°C for 10 minutes to degas and form a porous base material made of Cr and Mo, then heated to 1100°C at a temperature higher than the melting point of Cu (1083°C). The porous base material is infiltrated with Cu by heating for 10 minutes.

(2) Powder Cr and MO, mix them in a predetermined amount, place this mixed powder in a container made of alumina, etc., and place it in a non-oxidizing atmosphere (for example, in a vacuum, hydrogen gas, nitrogen gas, or (argon gas, etc.),
The temperature below the melting point of each metal (for example, if the Cu material is placed on the powder in advance, the temperature below the melting point of Cu or the Cu
If the material is not placed in advance, heat and hold at a temperature below the melting point of Cr (e.g. 5-60℃ at 600-1000℃).
After that, the porous base material is heated and maintained in the above atmosphere above the melting point of Cu (for about 1 minute).
This is done by infiltrating Cu into this base material and integrally bonding it.

(3) Powder each metal of Cu, Cr and MO, mix them in a predetermined amount, and prepare this mixed powder.

is press-molded to form a mixed powder, and then this mixed element is heated in a non-oxidizing atmosphere at a temperature below the melting point of Cu (e.g. 1000°C) or above the melting point of Cu and below the melting point of other metals (e.g. 1100°C). Heating and holding at a temperature of (5°C)
(about 60 minutes), and then each metal powder particle is integrally bonded.

Here, the particle size of the metal powder is -100 mesh (149
(μm or less) (-60 mesh (250 μm or less) is sufficient. However, if the particle size becomes larger than 60 mesh, the diffusion distance will increase when each metal powder particle is diffusion bonded. When it is necessary to increase the heating temperature or increase the heating time,
Productivity will decrease. On the other hand, as the upper limit of the particle size decreases, uniform mixing (uniform dispersion of each metal powder particle) becomes difficult, and it is easy to oxidize, making handling troublesome and requiring pretreatment before use. Since there are problems such as smearing, etc., there is naturally a limit, and the upper limit of the particle size is selected based on various conditions.

Note that the same considerations apply to the particle size of the metal powder when manufacturing the composite metal forming the arc diffusion portion 3a. In addition, the above-mentioned manufacturing method (2), (
In any of 3), a vacuum atmosphere is preferable as a non-oxidizing atmosphere since it has the advantage that degassing can be performed simultaneously during heating and holding. However, even when manufactured in a non-oxidizing atmosphere other than a vacuum atmosphere, there is no difference in performance as an electrode for a vacuum interrupter.

Next, I-A produced in substantially the same manner as production method (1)
Ingredient composition (5us30450% by weight and Cu5Q weight r
The structural state of the composite metal with rr,%) is shown in Figure 4 (A) to (
The result looked like the X-ray photograph shown in El.

In other words, the X-ray photograph in Figure 4 (N) is a secondary electron image, and the X-ray photograph in (B) is a characteristic X-ray image showing the dispersion state of Fe, with white parts scattered like islands. It is Fe.Also,
The X-ray photograph in (C) is a characteristic X-ray image showing the dispersion state of Cr, and the gray parts scattered like islands are Cr. (DJ's X-ray photograph is a characteristic X image showing the dispersed state of Ni, and the gray areas scattered like islands are Ni.

Furthermore, the X-ray photograph in (E) is a characteristic X-ray image showing the dispersed state of Cu, with the white portion being Cu.

Therefore, the particles of SUA 304 are bonded to each other to form a porous base material, and Cu is infiltrated into the pores (voids) of this base material to form a strongly bonded composite gold column. I know that there is.

In general, the composition of the II-A component produced according to the production method (1) (Cu50% by weight, CrlO weight Ei% and Mo
4Q weight H%).

I [-B component composition (Cu5Q wt%, Cr25 wt% and Mo 25 wt%) and II-C component composition (Cu
5Q weight section.

The structural state of each composite metal of Cr4Q weight t% and Mo weight % is shown in Figure 5 (Al- (D), Figure 6 (A) to (Di) and Figure 7 (2) (N to CD+). X to show
It looked like a line photo.

That is, the X-ray photographs in Figures 5 (CA), 6 (A), and 7 (N) are secondary electron images;
The radiograph is a characteristic X-ray image showing the dispersion state of Cr, and there are white parts scattered like islands of Cr'T:. In addition, each figure (C
) is a characteristic X-ray image showing the dispersion state of Mo,
The white parts scattered like islands are Mo. In addition, each figure (
The X-ray photograph in D) is an LRF X-ray image showing the dispersion state of Cu, and the white part is CuT.

Therefore, the Cr and M particles are diffusion bonded to each other to form a porous base material, and Cu is infiltrated into the pores (voids) of this base material to form a strong bond with the composite metal. It turns out that it is.

On the other hand, the I-A component composition forming the arc diffusion part 3a,
Each composite metal of I-B component composition and 1-c component composition and II-A component composition forming contact portion 3b, n-B
The test results of the component composition and the properties of each composite metal of the -C component #[II composition] were as follows. This cr, I-B
The composition of the components is SUS 30470'rR@CH and 30% by weight of Ca, I-C/leather string composition, SUS
30430% by weight and Cu 7Q heavy metal. Each of the composite metals having the I-B component composition and the I-C component composition was produced in the same manner as the composite metal having the I-A component composition.

(1) Electrical conductivity (IACS Chi) Arc diffusion part I-A component composition 5 to 15 coefficient I-B
Ingredient composition 4-8 rice cake 1-c component group W, to-30 contact part I [-A component composition 40-50 Yu I [-B
Ingredient composition: 40-50 cm m-c component composition: 40-50% (2) Hardness Arc diffusion part: 100-180 Hv (1 kg) Contact part: 120-1801 F (v (1 kg))
The arc diffusion part 3a is made of a composite metal with an I-A component composition and is formed into a hat-shaped disk shape with a diameter of 100%, and the welding part 3b is made of a composite metal with a II-A component composition and has a diameter of 60%.
The electrodes 3 shown in Fig. 2 were formed by forming the cap-shaped disk shape of FX, and the performance verification results of the vacuum interrupter shown in Fig. 1 by incorporating this pair of electrodes 3 are as follows. It became like this.

(The new conditions for 1 current and assist capacity are rated voltage 1.2KV (restart voltage 2),
K.V.

JEC-181), L and breaking speed 1.2 to 1.5 m
It was possible to cut off a current of 60 KA (r, m, s, ) at lg.

In addition, the rated voltage is 84KV (restarting voltage is 143I (V, J
EC-181)? Shutoff speed &Ot'n/! At the time of 1, I was able to do a 50 KA (r, m, s.) 'rrr, flow, and do it.

In addition, when the arc diffusion part 3a is made of each composite metal of I-B component composition and ■-C component composition, and when the contact part 3b is made of each composite metal of n-B component composition and n-c component composition, and comparison. The current breaking ability of each product tested under the same conditions is as follows:
The results are shown in Table 1.

1 (2) Dielectric strength When the gap was maintained at 30% and a shock wave withstand voltage test was conducted, a dielectric strength of ±400 KV (variation ±LOKV) was shown. Further, similar tests were conducted after cutting off a large current (60 KA) many times, but there was no change in dielectric strength. Ishi et al. conducted a similar test after cutting off a small current (80 A), but the dielectric strength hardly changed.

In addition, when the arc diffusion part 3a is made of composite metals (-B component composition, I-C component composition), and the welding part 3b is made of n-B
The dielectric strength of each composite metal of component composition and [-C component composition both showed values similar to those of the combination of I-A component composition and II-A component composition. Table 2 shows the results of each shock wave withstand voltage test of the product of the present invention (combination of I-A component composition and II-A component composition) and Hiku product.

Table 2 (3) Welding resistance 130 kl? under a pressure of 25 KA (r, m,
s, ) for a total of 3 seconds (IEC short-time current standard), it can be removed without any problem with a static removal force of 200 yen, and the subsequent increase in contact resistance is 2 to 3 seconds.
It remained at 8%. In addition, under a pressure of 1000 kg, 5
0KA(r.

There was no problem in tripping after applying a current of m, a, ) for 3 seconds, and the increase in contact resistance after that was only 0 to 5 cm, indicating sufficient welding resistance.

In addition, when the arc diffusion part 3a is made of each composite metal of I-B component composition and I-C component composition, and the contact part 3b is made of n-B component composition.
Similar results were obtained when using composite metals having the component composition and the component composition ①-c.

(4) Breaking capacity for delayed small current (inductive load) 30
The current test conducted with A current applied showed an average of a9A (standard deviation σn=0.96=number of samples n=100).

In addition, when the contact part 3b has a II-B#: partial composition, the average a7A (σn = 1.26, n = 10
0), and the l-C component composition, the average &9A(σ
n = 1.5, n = 100). Further, the same @ was also shown when the arc diffusion portion 3a had an i-B component composition and a 1-c component composition.

(5) Handling small lead current (capacitive load) [Capability 1.
25 Voltage; 84KV x-7;j, 80A cD M
-+ Small equipment flow test (JEC-181), 1000
It was repeated 0 times, but the restrike occurred 0 times.

In addition, when the arc diffusion part 3a is made of each composite metal of I-B component composition, ■-〇 component composition, and the contact part 3b is made of If-
Similar results were obtained when composite metals having the B component composition and the nc component composition were used.

By the way, when the component composition of the composite metal forming the arc diffusion part 3ae is outside the composition range of 30 to 70% by weight of austenitic stainless steel and 30 to 70% by weight of Cn, satisfactory characteristics could not be obtained. .

That is, 30% by weight of austenitic stainless steel
In the case of very low conductivity, the occurrence of wide eddy currents with high conductivity became significant. In addition, the strength was lowered, the durability was deteriorated, and the thickness of the arc diffusion part had to be increased. On the other hand, when the content of the austenitic stainless steel exceeds 70% by weight, the breaking performance significantly deteriorates.

Further, the component composition of the composite metal forming the contact portion 6b is C
u2O~70wt% + Cr 5~70M fit
%, Mo other than the composition range of 5 to 70% by weight, satisfactory properties could not be obtained.

That is, when Cu is 20% less by weight, the conductivity decreases and the contact resistance is significantly increased, while when it exceeds 70% by weight, the welding force and tearing value are significantly increased, and the insulation Yield strength decreased significantly. Also,
When Cr was less than 5% by weight, the dielectric strength decreased significantly, while when it exceeded 70 M, -f/-t% gold, the electrical conductivity and mechanical strength decreased significantly. Furthermore, when Mo was less than 5% by weight, the dielectric strength decreased significantly, while when it exceeded 70% by weight, the mechanical strength decreased significantly and, in addition, the δ break value became significantly large. .

In addition, in the above-mentioned implementation, the coil 4 was described as a dedicated/divided flow type, but the coil 4 is not limited to this. It's also good. Further, the electrical connection between the electrode 3 and the coil 4 is not limited to the case where the auxiliary coil 17 bonded to the back of the electrode 3 is used. One end may be directly connected to the center of the back surface of all the electrodes. Moreover, it is not limited to the case where the coil 4 is provided on the back of the electrode 3.
As described in Publication No. 6-57443, etc., 1. Of course, the coil may be arranged so as to surround the pair of electrodes, or the coil may be arranged outside the vacuum vessel as described in Japanese Patent Publication No. 13045/1983.

Effects of the Invention As described above, the present invention provides an arc diffusion portion of each electrode of a vacuum ink jetter made of austenitic stainless steel 30 to 70.
% by weight and a composite metal consisting of 30 to 70% by weight of Cu, and the contact portion is made of a composite metal of 30 to 70% by weight of Cu2O.
Since it is made of a composite metal consisting of 5 to 70% weight of Cr, and 5 to 70% of Mo, the current cutting ability can be greatly improved compared to conventional ones.

Moreover, it is possible to obtain an excellent dielectric strength similar to the conventional one in which the contact portion is formed of a 20Cu-80W alloy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the vacuum interrupter of the present invention, FIGS. 2 and 3 are X-ray photographs showing m-filament M of composite metal, and FIG. 5 (A) . CB) t (Cn, (J)), Figure 6 (A),
(B), (C), (D) and Figure 7 (AJ
1 (B) 1 (C) 1 (D) are X-ray photographs showing the structural states of different aIy of the composite metals forming the contact portions. 1... Vacuum container, 2... Electrode rod, 3... Electrode, 3
a... Arc diffusion part, 3b... Contact part, 4... Coil. Figure 2 Figure 7 (A-) Figure 7 (B) Figure 7 (I))

Claims (1)

[Claims] (1) A pair of electrode rods are introduced into a vacuum container so that they can approach and separate from each other freely, and an electrode consisting of an arc diffusion part and a contact part is fixed to the P3 end of each electrode rod, respectively. In a vacuum intambuter comprising a coil for applying an axial magnetic field parallel to the arc to the outside of the vacuum vessel or a circular portion of the vacuum vessel, the arc diffusion portion of each electrode is made of austenitic steel/renu steel 30 to 70. Made of composite metal consisting of 30-70% by weight of copper.
1, and the contact area is made of 20-70% by weight of copper and 5% of chromium.
70% by weight and molybdenum by 5-70% by weight.