JPS6074317A - 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 provided with means for generating an axial magnetic field (longitudinal magnetic field) parallel to an arc.

Conventional vertical magnetic field type vacuum interrupters apply a vertical magnetic field parallel to the arc to disperse the arc on the electrode surface and prevent its local concentration, thereby preventing excessive melting of the electrode. This aims to improve the current interrupting ability by placing a pair of electrode rods in a vacuum container so that they can approach and separate from each other, and at the inner end of each electrode rod from the arc diffusion part and the contact part. Naruden and elm were fixed to each other, and a coil as a means for generating a longitudinal magnetic field was created using the Japanese Patent Publication No. 42-13045.
As described in Japanese Patent Publication No. 53-41793, Japanese Patent Publication No. 54-22813, or Japanese Patent Application Laid-Open No. 56-130,
As described in Japanese Patent Application No. 037, etc., it is provided on the back of each electrode in the vacuum container, and furthermore,
As described in Japanese Patent No. 7443, etc., it is arranged around the outer periphery of a pair of electrodes in a vacuum container.

By the way, the electrode material (?l.

The following characteristics (1) to (1) are required.

(1) High current cutting ability (11) High withstand voltage (Ill) Low consumption (1■) Small current cutting value (v) Small contact resistance (vl) Small welding force As disclosed in Japanese Utility Model Application Publication No. 57-89242, for example, some conventional vertical magnetic field type vacuum interrupter electrodes have an arc diffusion part and a contact part made of stainless steel.

Such an electrode can suppress the generation of a thin current generated in the electrode due to a vertical magnetic field, and is made of a material having high mechanical strength. However, if stainless steel, which has low conductivity and high mechanical strength, is used for the contact part, the above characteristics (tVL (V) and (vl) cannot be obtained.

Therefore, the arc diffusion part was formed of stainless steel, and the contact part was made of copper (Cu) with a small amount of bismuth (B i
Cu-Bi alloy containing (e.g. Cu-0,
5B1 alloy) is known. However, such electrodes do not have large current blocking capabilities.

Although it has excellent welding resistance and contact resistance, it is not suitable for high voltage applications.

In addition, for high voltage applications, the arc diffusion part is made of stainless steel, and the contact part is
An electrode made of a Cu-W alloy (e.g. 20Cu-80W alloy) in which Cu contains tungsten (W) is known, as described in Publication No. 21. '1d style and it is difficult to cut the JP.

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 is excellent in both current interrupting 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 relatively close to each other in an empty container, and at the same time introduces arc diffusion into the inner part of each electrode rod. A vacuum interrupter comprising a coil for applying an axial magnetic field parallel to the arc to the outside of the vacuum vessel or the inside of the vacuum vessel, to which electrodes consisting of a part and a contact part are respectively fixed, The arc diffusion part of the pole is made of magnetic stainless steel, and the contact part is made of copper 20~70.
weight%.

It is made of a composite metal consisting of 5 to 70% by weight of chromium and 5 to 0% by weight of molybdenum.

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 interrupter showing an embodiment of the present invention, and this vacuum ink crack is positioned on the axis of a vacuum vessel 1 and a pair of electrode rods 2, 2 are connected relative to each other. A pair of electrodes 3゜3 in the shape of a hat-shaped disk are mechanically fixed to the inner end of each electrode rod 2 with an insulating spacer interposed between the electrode rods 2 and 3. A loop tl that is arranged on the back of the electrode 3 and flows in the axial direction (vertical direction in FIG. 1) through the electrode rod 2 is connected to the electrode rod 2.
It is generally constructed by electrically connecting coils 4, 4 that generate a vertical magnetic field by changing the current flow.

That is, the vacuum container 1 has two cylindrical insulating tubes 5, 5 made of glass or ceramics fixed to both ends.
e -Ni-Co alloy or Fe-N'i alloy, etc., are joined through one side of the thin annular sealing fittings 6, 6... to form a single insulating cylinder, and both open ends thereof is closed by disk-shaped metal end plates 7, 7 via the other sealing fittings 6, 6, and the inside is vacuumed (for example, 5
It is formed under pressure below Q Torr. Each of the electrode rods 2 is introduced into the vacuum container 1 from the center of each quadrant end plate 7 so as to be able to approach and separate relative vC 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 1 through a metal bellows 8. It 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 'ε electrode rod is made of a material with high conductivity such as Cu, and has a disk shape with a suitably larger diameter than the diameter of the electrode rod 2. a mounting base 4a, two arms 4b extending outward in the radial direction (in the left-right direction in FIG. 2) from opposing positions on the outer periphery of the mounting base 4a, and two arms 4b extending outward from the end of each arm 4b to the mounting base 4a.
A 1/2 branch type coil 4 consisting of an arc portion 4c curved in an arc shape in the same direction with the center at the mounting base x 4
The four parts 1 formed on one (lower side in Fig. 2) of a
It is fixed by brazing through 3.

The coil 4 includes a ring-shaped attachment part 14a fitted to the outer periphery of the inner end of the electrode rod 2 by brazing, and a mantissa support arm 14b extending radially outward from the outer periphery of the receiving part 14a. , and is reinforced by brazing with a coil reinforcing body 14 consisting of a ring-shaped support portion 14c connecting the ends of each support arm 14b.

The coil reinforcing body 14 is made of a material with high fundamental strength and low conductivity, such as stainless steel.

Four circular parts 15 are provided between the other mounting bases 4a of the coil 4, and these four parts 15 are made of a material with high mechanical strength and low conductivity, such as stainless steel or Inconel. An insulating spacer 16 formed into a short cylindrical shape from a material has a small diameter flange 16a formed at one end thereof.
It is fixed by brazing through. The large-diameter flange 16b formed at the other end of the insulating spacer 16 is fitted with a circular plate shape having a diameter appropriately larger than that of the large-diameter flange 16b and having a through hole with approximately the same diameter as the inner diameter of the insulating spacer J6. A base 17a, two arms 17b extending radially outward from opposing positions on the outer periphery of the mounting base 17a, and a radius of curvature approximately equal to the arcuate portion 4C of the coil 4 from the i'iiA portion of each arm 17b. The auxiliary coil 17 is formed of a material with high conductivity and has a circular arc portion 17C curved in an arc shape with an appropriate length in the same direction opposite to the circular arc portion 17C. The auxiliary coil 17 and the coil 4 are fixed to each other by brazing through an engagement step 18 provided on the surface (lower in FIG. 2). One end is fixed to the provided recess 19, and the other end is electrically connected via an axial current-carrying pin 20 inserted into a through hole 21 provided at the end of each arcuate portion 4C of the coil 4. There is.

On the auxiliary coil 17, the electrode 3 formed to have approximately the same diameter as the coil 4 is joined to the mounting base 17a by brazing through the four parts 22 provided at the center of the back surface, and is also connected to the mounting base 17a by brazing through the back surface. It is joined to each arm 17b and arc portion 17c. IK (r3 is an arc expansion 1) formed in the shape of a cap-shaped disk with four circular parts 23 provided at the center of the opposing surface (upper surface in FIG. 2) and gradually becoming thinner as it approaches the periphery! -3a, and arc diffusion part 3a, which has a flat circular contact surface on the opposing surface and is formed in a cap-shaped circle/plate shape that becomes gradually thinner as it approaches the periphery.
and a contact portion 3b fixed to the recess 23 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 magnetic stainless steel,
For example, it is made of ferritic or martensitic stainless steel. Ferritic stainless steels include 5us405, 429°430, 43
Martensitic stainless steels such as 0F and 434 include SUS 403, 410, 416, and 4.
20.

431, 440C and the like. In addition, ferritic stainless steel has a conductivity of approximately 2.5 cm (IACS%
), tensile strength of 49 kgf/un2 or more and 1
Martensitic stainless steel has a hardness of 90Hv (Iky) and has a 4-electricity of approximately 3.0 chi 60 kgf
/ mm2 or more and a tensile strength of 190 Hv (1k
g) hardness.

Mata, m Contact part 3 b C, Cu 20-70 @ skin (formed of a composite metal containing chromium (Cr) 5-70% f% and molybdenum (Mo) 5-70% by weight. This composite metal has a conductive leather of 20-60% and a hardness of 120-1801-1V (1ky).

On the other hand, the encapsulated metal forming the contact portion 3b is manufactured by the various methods described below. Cr, Mo
and a container made of a material that does not react with Cu (e.g. alumina), place a Cu block on top of the container, and place it in a vacuum (5X 1O-Torr) for 10 minutes.
Heating at 00℃ for 10 minutes to degas and remove Cr and M.
A porous base material made of O is formed, and then Cu is infiltrated into the porous base material by heating at 1100'C, which is higher than the melting point of Cu (1083C), 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.),
Temperature below the melting point of each metal (for example, below the melting point of Cu if Cu material is placed on the initial body in advance, or below the melting point of Cu)
If the material is not placed in advance, the temperature is below the melting point of Cr).
60 minutes) to form a porous base material, and then heated and held above the melting point of Cu in the above atmosphere (for example, at 1100°C for about 5 to 20 minutes) to form a porous base material.
This is done by infiltrating and bonding them together.

(3) Make metal powders of Cu, Cr, and Mo, mix them in predetermined amounts, press-mold this mixed powder to form a mixed element body, and then place the mixed element body in a non-oxidizing atmosphere. (for example, 1000 °C) or above the tm+ point of Cu and below the melting point of other metals (for example, 1100 °C).
(approximately 5 to 60 minutes i+I), and each metal powder particle is integrally bonded.

Here, the particle size of the metal powder is -100 mesh (149
The thickness is not limited to -60 mesh (250 μm or less).

However, when the particle size becomes larger than 60 meshes, when diffusion bonding each metal powder particle, it is necessary to increase the heating temperature (or increase the heating time m) as the diffusion distance increases. 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 Since there are problems such as the need for pretreatment before use, there is a natural limit, and the upper limit of the particle size is selected based on various conditions.

Further, in any of the above manufacturing methods C2) and (3), a vacuum atmosphere is preferable as the 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 with two A-ink inks.

Next, component composition (Cu) manufactured by manufacturing method (1)
50 wt' Ir t Cr 10 M41)l % and 84. o 40%), II component composition (Cu
50% by weight, Cr 25 Jli: i+? and Mo25% by weight) and I (r component composition (Cu50
Weight %, Cr 40 weight value and Mo 10-f1@
%) of each composite metal is the fourth Dl(
A)~p), Figure 5 (Spring ~ (D)) and Figure 6 West ~ Mountain!

That is, the X-ray photographs in FIG. 4), FIG. 5, and FIG. 6 (A) are secondary electron images, and the
(The Q photo is a characteristic X-ray image showing the dispersion state of Cr, and the white parts scattered like islands are Cr.
The X-ray photograph in C) shows the dispersion state of MO!
The white parts scattered like islands are MO. Furthermore, the X-ray photographs in each figure (c) are characteristic X-ray images showing the dispersion state of Cu, with the white portion being Cu.

Therefore, Cr and MO particles are diffusely 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 metal. It can be seen that

On the other hand, the test results of the properties of the composite metals of the I component composition, the ■component composition, and the ■component composition that form the contact Sir *lj 3 b are as follows.

(1) 2F7. Calculator (IAC8%) 40-50 factor (2) Hardness 120-180 Hv (1k!9) In addition, the arc diffusion part 3a is formed from ferritic stainless steel 5us430 into a cap-shaped disk shape with a diameter of 100 tn/m. The contact portion 3b is made of a single-component composite metal in the shape of a hat-shaped disk with a diameter of 60 rn/m to form the electrode 3 shown in FIG. The results of various performance verifications conducted as a vacuum ink cleaner (not shown) are as follows.

(1) Current breaking ability and JP cutting condition are rated voltage 12 kV (emf voltage 21
kV, JEC-181), shi'<"breaking velocity i,
2~], 62 kA (r, m, s) at 5771/S.

) was able to cut off the current. Also, the rated voltage 8
4 kV (Inverted N pressure 143 kV, JRC-181,)
, 41 kA (r, m,
s,)'s 'iji: I was able to do this and cut off JP.

Note that the arc diffusion part 3a is made of martensitic stainless steel V.
;C, when steel SUS 410 is used, when the contact part 3b is made of each composite metal of component composition 1, 1F 1 component, and for comparison products tested under the same conditions, the current interrupting ability is as shown in Table 1. became.

Table 1 (2) The dielectric strength gap was maintained at 30 m/m and the shock wave 1. lII'
When the pressure test was carried out, the voltage was 400kV (variation ±
It showed a dielectric strength of 10kV). Also, dog 1wa 5 style (
In 1962, a similar test was conducted after multiple interruptions, but there was no change in dielectric strength. Furthermore, advance small tit (80
After A) was cut off, a test was conducted on the same surface, but there was almost no change in dielectric strength.

In addition, the arc diffusion part 3a is made of SUS 410! 2
) When the contact portion 3b is made of 6 complex metals with the component composition (■) and the composition (■), the insulation force is 5us434 in both cases.
It showed a value similar to that of the combination of the composite metal with the I-component composition. In addition, 11% of each of the fu6aki product (combination of sus4:3-1 and component composition) and the comparative product. (7:l The results of the Seriwa withstand voltage test were jc as shown in Table 2.

(3) Bath resistance: 25 kA (r, m, s,'
.

After energizing 4 currents for 3 seconds (IEC short-time current standard), the contact resistance could be removed without any problem with a static removal force of 200 kg, and the increase in contact resistance after that was only 2 to 8 lines. Also, under a pressure of 1000 kg, 50 kA (
There was no problem in disconnection after applying a current of r6m, s, ) for 3 seconds, and the subsequent increase in contact resistance remained at 0 to 59b, providing sufficient 1llt swamp df properties.

In addition, the arc diffusion part 3a was made of 5uS410, and the contact part 3b had a component composition of (2) and a component composition of 111.

Similar results were obtained when using a scratched alloy metal.

(4) Interrupting capacity for delayed small current (conductive load) The current interrupt value obtained by applying 308 currents was 3.9 A on average (standard deviation an = 0.96, number of samples n = 10 (
1) was shown.

In addition, when the contact part 3b has a component composition of
．． 7A (q, n=1.26.n=100), with a composition of 111 components, the average is 3.9A (σn=1.5.
n=1oo). In addition, the arc diffusion part 3a is 5u
Similar results were obtained when using s410.

(5) Breaking capacity of small leading current (customer load) Bi
; 84 icV x'7;F', 80 A 77)
Mmi small E 61e trial (JEC-181), 1000
This was carried out 0 times, but the ladle ignition was 0 times.

In addition, when the arc diffusion part 3a is made of SUS 410 and the contact ↑4j (3b is
Similar results were obtained when the percentage of each Ki alloy was set at 4%.

By the way, the component composition of the genus A-0) that forms the contact portion 3b is Cu-1jt-20 to 70 gi%, C
r 5-70 for regular company, Mo5-70 for weight, in cases outside the composition range, add 1 h'1 to 1 person q'j to 'I
I couldn't do anything about it.

That is, if Cu is less than 20%, 1.
0 city rate decreased and contact resistance increased significantly, while 70
When the electric current exceeds iit%, the melting force and shearing force become significantly large, and the dielectric strength significantly decreases. Moreover, when Cr was less than 5% by weight, the dielectric strength decreased significantly, while when it exceeded 70% by weight, the electrical conductivity and mechanical strength decreased significantly. Furthermore, when MO was less than 5% by weight, the dielectric strength was significantly lowered, while when it was more than 70% by weight, the mechanical strength was significantly lowered and its 5% cutoff value became significantly large.

In addition, in the above-mentioned embodiment, a case was described in which the coil 4 was a 1/2 shunt type, but the coil 4 is not limited to this.
/3 branch type or 1/4 branch type may be used. 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. may be connected directly to the center of the back of the electrode. Furthermore, the coil 4 is not limited to the case where the coil 4 is provided on the back of the electrode 3;
As described in Japanese Patent Publication No. 6-57443, a coil is arranged to surround a pair of electrodes, or as described in Japanese Patent Publication No. 42-13045, a coil is placed in a vacuum container. Of course, it may be arranged outside the .

Effects of the Invention As described above, in the present invention, the arc diffusion part of each electrode of the vacuum intercalator is formed of magnetic stainless steel, and the contact part is made of Cu2O~70% by weight.

Since it is made of a composite metal containing 5 to 70% by weight of Cr and 5 to 70% by weight of Mo, the current interrupting ability can be greatly improved compared to conventional ones. Moreover, the contact part is 2
It is possible to obtain the same excellent dielectric strength as the conventional one made of 0Cu-80W alloy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the vacuum interrupter of the present invention, FIGS. 2 and 3 are a longitudinal sectional view and an exploded perspective view of the electrode in FIG. 1, respectively, and FIG.
d, (C), (1'), six 5 Figures (N, m
, + (O), ・(D) O and Figure 6 (4), (υ,
@, 0) are X-ray photographs showing the structural states of different compositions 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 4 (A,) Figure 4 CB) Figure 6 (0

Claims (1)

[Claims] (1) A pair of electrode rods are introduced into a vacuum container so as to be able to approach and separate from each other, and an electrode consisting of an arc diffusion part and a contact part is fixed to the inner end of each electrode rod, and In a vacuum interrupter, the arc diffusion part of each electrode is formed of magnetic stainless steel, and the contact part is made of copper. 20
A vacuum interrupter characterized in that it is formed of a composite metal consisting of ~70% by weight, 5 to 7031 ift% chromium, and 5 to 70% by weight molybdenum.