JPS6336918Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a vacuum interrupter, and particularly to a so-called vertical magnetic field type vacuum interrupter that applies an axial magnetic field (vertical magnetic field) to an arc.

Prior art Vertical magnetic field type vacuum interrupters apply a parallel vertical magnetic field to the arc, thereby stably and uniformly dispersing the arc on the electrode surface, thereby improving current flow and breaking ability. .

Conventionally, a vertical magnetic field type vacuum interrupter has a disc-shaped base and a disc-shaped base extending radially from the circumferential surface of the base at the inner end of a pair of conductive shafts that are introduced into a vacuum container so that they can move toward and away from each other. A so-called shunt type coil, which is made up of a plurality of arms and a circular arc section curved in an arc shape from the end of each arm centering on the base, is connected through one surface of the base, and
A disk-shaped electrode is coaxially connected to the other surface of the base of the coil with a high-resistance spacer interposed, and the end of the arc portion and the periphery of the back surface of the electrode are connected by an axial connecting conductor. It is configured.

However, the vacuum interrupter described above
Since the coil is made of an electrode material with low mechanical strength, such as copper or copper alloy, it needs to be reinforced, and since it is provided at a distance from the back surface of the electrode, there is a problem that the strength of the longitudinal magnetic field is reduced.

Furthermore, since the electrodes are made of a highly conductive electrode material such as copper, there is a problem in that eddy currents are generated in the electrodes so as to reduce the magnetic flux density of the longitudinal magnetic field and cause a phase lag in the magnetic field.

In order to reduce the generation of the above-mentioned eddy current, electrodes are known in which multiple slits are provided in the radial direction, but this leads to a decrease in the mechanical strength of the electrode itself and a decrease in withstand voltage due to the edges of the slits. There's a problem.

Purpose of the invention In view of the above-mentioned problems, the present invention aims to provide a vertical magnetic field type vacuum interrupter that can effectively utilize a vertical magnetic field and has excellent durability.

Structure of the invention In order to achieve the above object, the present invention introduces a pair of conductive shafts into a vacuum container so as to be able to approach and separate from each other, and has an inner end of each conductive shaft extending radially outward. The adapter is provided with an adapter having one or more arm portions, which are made of metal with high tensile strength and low conductivity, and are formed into a cap-shaped disk shape with a flat contact portion at the center of the opposing surface, and a disk-shaped adapter on the back surface. and 1 or 2 extending radially outward from this base.
The above-mentioned electrodes each having a coil connected to the arm portion and a ring portion connected to the end portion of the arm portion and concentrically surrounding the base portion are connected coaxially with a high-resistance spacer interposed therebetween. The ends of the arms of the adapter and the portions of the annular portions of the respective coils that are equidistant in the circumferential direction from the connection positions with the arms are connected via axial connection conductors.

Embodiments Hereinafter, embodiments of this invention will be described with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a vacuum interrupter showing an embodiment of the present invention.
are connected in series through one side of a thin annular sealing metal 2 made of Fe-Ni-Co alloy or Fe-Ni alloy fixed to both ends to form a single insulating cylinder, and both A vacuum container 4 is formed by closing the open end with disk-shaped metal end plates 3a and 3b via the other sealing fitting 2, and evacuating the inside to a high vacuum. A pair of conductive shafts 5a, 5b are introduced into the vacuum container 4 from the center of each metal end plate 2a, 2b so that they can be relatively approached and separated while maintaining the airtightness of the vacuum container 4.

Note that one (upper side in FIG. 1) conductive shaft 5
a is airtightly inserted into one metal end plate 3a, and the other conductive shaft 5b is inserted into the other metal end plate 3b while maintaining the airtightness of the vacuum vessel 4 with a metal bellows 6.
is inserted so that it can move freely in the axial direction (in the vertical direction in FIG. 1). Further, in FIG. 1, 7a and 7b are shaft shields and bellows shields attached to the respective conductive shafts 5a and 5b, 8a is a main shield concentrically surrounding each conductive shaft 5a and 5b, etc., and 8b is an auxiliary shield. .

At the inner end of each of the conductive shafts 5a, 5b, a second
3 and 4, it is made of a highly conductive metal such as copper, and has a disk-shaped mounting portion 9a and a radial direction from the outer peripheral surface of this mounting portion 9a (in FIG. 2). An adapter 9 consisting of an arm portion 9b extending outward (left-right direction) is fitted by brazing through a circular recess 10 provided on one surface of the attachment portion 9a.

The adapter 9 is for changing the course of the axial current flowing through the conductive shafts 5a and 5b in the radial direction so as to guide it to a coil to be described later.
A circular recess 11 which is suitably shallower than the recess 10 on one surface is provided on the other surface. In the recess 11, a high resistance spacer 12, which has a cylindrical shape integrally formed with a flange portion 12a at both ends and is made of a metal with low conductivity and high mechanical strength such as stainless steel or Inconel, is attached to the flange portion 12a at one end. It is fixed by intervening brazing.

The high-resistance spacer 12 is for coaxially connecting a coil and an electrode to the conductive shafts 5a, 5b while cutting off direct electrical connection with the conductive shafts 5a, 5b. .

Flange portion 12a at the other end of the high resistance spacer 12
As shown in FIGS. 2, 5 and 6, the metal is made of a highly conductive metal such as copper, and
A base 14a that is shaped like a cup and has a hole 13 in the center of its bottom, an arm 14b extending radially outward from the outer peripheral surface of the base 14a, and a concentric circle connected to the end of the arm 14b. A coil 14 consisting of an annular portion 14c surrounding the coil 14 is fixed by brazing via a base portion 14a such that its arm portion 14b is axially symmetrical to the arm portion 9b of the adapter 9.

The coil 14, together with the adapter 9, transfers the axial current flowing through the conductive shafts 5a and 5b to the conductive shaft 5.
This is for generating a vertical magnetic field by changing the current to a loop centered on a and 5b, and one end is connected to the annular portion 14c.
A hole 16 is fitted into a recess 15 formed equidistantly in the circumferential direction from the connection position with the arm 14b, and the other end is provided at the end of the arm 9b of the adapter 9.
(See Figs. 3 and 4) The axial connection conductor 17 connects the conductive shafts 5a and 5 via the adapter 9.
It is electrically connected to b.

Note that the base 14a of the coil 14 is connected to the arm 14b.
and is provided so as to slightly protrude in the axial direction from the annular portion 14c. In addition, the coil 14
Since the currents flowing through these are divided into different directions, longitudinal magnetic fields with different polarities are generated.

As shown in FIG. 2, an electrode 18 is fixed to the coil 14 through its back surface. That is, the electrode 18 includes an arc diffusion portion 18a in the shape of a cap-shaped disk having a flat circular opposing surface at the center of the surface;
A recess 1 provided at the center of the opposing surface of the arc diffusion section 18a
9 and a disk-shaped contact portion 18b that slightly protrudes from the surface and is fixed.

This electrode 18 is connected to the arc diffusion section 18a.
It is fixed to the base 14a of the coil 14 by brazing through the recess 20 provided at the center of the back surface of the coil 14, and
The back surface of the arc diffusion section 18a is joined to each arm section 14b and annular section 14c of the coil 14 by brazing.

Therefore, the arc diffusion portion 18a of the electrode 18 is
In order to reduce eddy current and improve mechanical strength,
It is made of a metal with low conductivity and high tensile strength.

The above metal is made by infiltrating copper into a porous base material made by diffusion bonding iron powder and chromium powder to each other at a temperature below their respective melting points. Composite metal of chromium and 5-40% by weight iron (electrical conductivity (IACS) 5-30%, tensile strength 30Kgf/mm2 or ^more ), or stainless steel (electrical conductivity 2-30%, tensile strength 50Kgf/ ^mm2 or more), Or, it is made by infiltrating copper into a porous base material made by bonding stainless steel powder to each other at a temperature below its melting point30~
A composite metal of 70% by weight copper and 30 to 70% by weight stainless steel (conductivity 4 to 30%, tensile strength 30 Kgf/mm ² or more) is used.

The contact portion 18b is made of a porous base material in which chromium and molybdenum powders are diffusion-bonded to each other at a temperature below their melting points in order to improve dielectric strength and current shedding ability and reduce current shedding value. It is made of a composite metal of 20 to 70% by weight copper, 5 to 70% by weight chromium, and 5 to 70% by weight molybdenum.

Note that the electrode 18 is not limited to the case where the arc diffusion part 18a and the contact part 18b are made of different electrode materials. For example, the electrode 18 is formed of a flat circular shape at the center of the surface using an electrode material with low conductivity and high tensile strength such as stainless steel. In other words, the arc diffusion part 18a may be formed only with the opposing surface as the contact part without providing the contact part 18b with a separate material. be.

Further, the thickness of the arc diffusion portion 18a is set to 10 m/m or less in order to reduce Joule heat, and the outer diameter of the flange portion 12a of the high resistance spacer 12 is
D ₂ and the diameter D ₃ of the contact 18b of the electrode 18 are set to be less than or equal to 1/2 of the diameter D ₁ of the arc diffusion portion 18a, respectively, for durability against impact force and reduction of eddy current.

The adapter 9, coil 14 and electrode 18
are reinforced by reinforcing members 21 fitted near the inner ends of the conductive shafts 5a, 5b.

That is, the reinforcing member 21 is made of a metal with low electrical conductivity and high mechanical strength, such as stainless steel, and as shown in FIGS. 2, 7, and 8,
It is formed from a ring-shaped attachment part 21a and four support arms 21b extending radially outward from the outer peripheral surface of the attachment part 21a with a length approximately equal to the arm part 9b of the adapter 9. ing. Then, the reinforcing member 21 has its appropriate supporting arm portion 21b.
is joined to the arm portion 9b of the adapter 9 by brazing, and is also fixed near the inner end portions of the conductive shafts 5a, 5b by brazing via the attachment portion 21a.

The end of the support arm 21b of the reinforcing member 21 and the annular part 14c of the coil 14 are made of a metal with low electrical conductivity and high mechanical strength, such as stainless steel, and one end is connected to the annular part 14c of the coil 14. The connection pin 24 is fitted into the recesses 22 (see FIGS. 5 and 6) drilled at equal positions of the support arm 21c, and the other end is inserted into the hole 23 provided at the end of the support arm 21b. connected.

In addition, in the embodiment described above, the adapter 9
Although the case has been described in which the mounting portion 9a is formed into a disk shape and is fixed to the conductive shafts 5a and 5b through one surface, the present invention is not limited to this. For example, the mounting portion may be formed into a ring shape and the conductive shafts 5a, 5b may be fitted.

Furthermore, although the coil 14 has been described as a 1/2 shunt type, the present invention is not limited to this, and can similarly be applied to a 1/4 shunt type or a 1/6 shunt type.

Effects of the Invention As described above, the present invention provides the following various effects compared to conventional ones.

(1) Since the coil is bonded to the back side of the electrode, the distance between both coils is shorter than in conventional models, making it possible to effectively utilize the vertical magnetic field.

(2) Since the electrodes are made of a metal with low conductivity and high tensile strength, the generation of eddy current can be significantly reduced.
It does not cause a decrease in the strength of the longitudinal magnetic field or a phase delay unlike the conventional ones, and it is possible to prevent the electrodes and the like from being damaged.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a vacuum interrupter showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the main parts, and Fig. 3 is a longitudinal sectional view of a vacuum interrupter showing an embodiment of the present invention.
4 is a plan view of the adapter, FIG. 4 is a cross-sectional view of FIG. 3, FIG. 5 is a plan view of the coil, FIG. 6 is a cross-sectional view of FIG. 5, and FIG. 7 is a plan view of the reinforcing member. FIG. 8 is a - sectional view in FIG. 7. 4... Vacuum container, 5a, 5b... Conductive shaft, 9...
...Adapter, 9a...Mounting part, 9b...Diversion part,
12...High resistance spacer, 14...Coil, 14
a...base, 14b...arm, 14c...arc part,
17... Connection conductor, 18... Electrode.

Claims (1)

[Scope of utility model registration request] A pair of conductive shafts 5a and 5b are introduced into the vacuum container 4 so as to be able to approach and separate from each other.
1 extending radially outward at the inner ends of a and 5b.
Alternatively, the adapter 9 is provided with two or more arm portions 9b, and is formed of a metal with high tensile strength and low conductivity into a hat-shaped disk shape with a flat contact portion at the center of the opposing surface, and has a disk shape on the back surface. base 14 of
a, one or more arm portions 14b extending radially outward from the base portion 14a, and an annular portion 14c connected to the end of the arm portion 14b and concentrically surrounding the base portion 14a. Bonded electrode 1
8 are coaxially connected with each other with a high-resistance spacer 12 interposed therebetween. A vacuum interrupter is formed by connecting a portion equidistant to a portion thereof via an axial connecting conductor 17.