JPS5847628Y2 - Vacuum cutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum breaker, and more particularly to a vacuum breaker equipped with a so-called vertical magnetic field electrode.

Recently, in order to improve the breaking capacity of vacuum circuit breakers, devices have been equipped with so-called vertical magnetic field electrodes that apply an axial magnetic field (vertical magnetic field) parallel to the arc generated when the electrodes open. Vacuum circuit breakers are known.

A conventional vacuum breaker equipped with so-called vertical magnetic field electrodes has a pair of electrode rods arranged facing each other in a vacuum container so that they can move toward and away from each other, and an external circuit is inserted into the inner end of each electrode rod.
Pairs of disc-shaped contact electrodes that touch and separate from each other are provided by joining them with a disc-shaped spacer made of a high-resistance material interposed therebetween, and each electrode rod and each contact electrode are connected to each other. It is electrically connected by an annular coil electrode with an end placed close to the outer periphery of the opposite back surface.
A nearly loop-shaped current flowing through the coil electrode generates a vertical magnetic field parallel to the electrode rod, and this vertical magnetic field causes the arc generated when the contact electrode opens to be stably and uniformly distributed over the contact electrode surface, increasing the breaking capacity. We are trying to improve.

However, the spacer for electrically insulating the electrode rod and the contact electrode as well as for bonding and supporting the contact electrode to the inner end of the electrode rod is generally made of a high resistance material such as austenitic stainless steel. If the electrode is made of a material with lower conductivity than the commonly used copper, it will be difficult to completely electrically insulate the electrode rod and the contact electrode, and the contact will occur from the electrode rod through the coil electrode. The current flowing into the electrode is shunted to the spacer, albeit slightly.

In addition, conventional spacers are formed into a disk shape, and both end surfaces of the spacer are completely joined to the inner end surfaces of the contact electrode and electrode rod by brazing, which tends to further increase the shunt current. Ta.

Furthermore, when forming a contact electrode with a large diameter in response to an increase in breaking capacity, the spacer must also have a large diameter to strengthen the bonding support of the contact electrode. There was a risk that the current would increase.

Therefore, the current flowing through the coil electrode is reduced as the current flowing into the contact electrode through the spacer increases,
As the longitudinal magnetic field generated by the coil electrode became weaker, the breaking capacity decreased.

The present invention was made in view of the above-mentioned problems, and its purpose is to connect a spacer to a first annular spacer that connects and supports a contact electrode and an electrode rod at their respective centers; A second spacer is fitted to the first spacer to bond and support the vicinity of the outer periphery of the opposite back surface of the electrode, and the spacer is configured to reduce the bonding area of the spacer to the contact electrode and the electrode rod, thereby reducing the longitudinal magnetic field caused by the coil electrode. In addition to making it stronger and improving its breaking capacity,
An object of the present invention is to provide a brushless breaker that strengthens the bonding support of contact electrodes.

Hereinafter, one embodiment of this invention will be described in detail using the drawings.

FIG. 1 is a schematic configuration diagram of a vacuum breaker 1 according to the present invention.
Both ends of an insulating tube 2 formed into a cylindrical shape and made of an insulating material such as glass or ceramic are sealed with disk-shaped end plates 3 and 4 made of metal, and the inside of the insulating tube 2 is kept in a high vacuum in a vacuum container 5. A cylindrical fixed electrode rod 7 made of copper, into which a reinforcing rod 6 made of austenitic stainless steel is fitted and protruded appropriately, is inserted into the center of one end plate 3 and inserted into the center of the axis. The movable electrode rod 9 is fixedly disposed, and similarly to the fixed electrode rod 7, a reinforcing rod 8 is appropriately protruded and inserted into the movable electrode rod 9, and the movable electrode rod 9 is slidably inserted through the center of the other end plate 4. In addition, it is airtightly mounted via a metal bellows 10, and is disposed opposite to the fixed electrode rod 7 so as to be able to approach and separate from it.

The inner ends of the fixed and movable electrode rods 7 and 9 are joined via a spacer 11 made of a non-magnetic high resistance material such as austenitic stainless steel, as will be described later, and are brought into contact with and separated from each other to form an external circuit ( (not shown), and a coil electrode 13 disposed close to the outer periphery of the opposite back surface of each contact electrode to electrically connect each contact electrode 12 and each electrode rod 7, 9. Fixed and movable electrodes 14, 15 are mounted.

Note that the reinforcing rod 8 fitted into the movable electrode rod 9 is appropriately connected to an operating mechanism (not shown) that reciprocates the movable electrode rod 9 in the axial direction (up and down direction in FIG. 1), and is fixed,
External leads (not shown) for connecting the vacuum breaker 1 to an external circuit are appropriately connected to the outer ends of the movable electrode rods 7 and 9.

In addition, in FIG. 1, 16.16 is a cap-shaped shaft shield for protecting the fixed and movable electrode rods 7 and 9 and the bellows 10, and 17 is the vicinity of the inner circumference of the insulating tube 2. The main shield is disposed in the main shield, and the center part of its outer periphery is supported by a ring-shaped support fitting 18 implanted in the insulating cylinder 2.

As shown in FIGS. 2 and 3, the inner end of the movable electrode rod 9 has an annular coil portion 13a with an end centered around the movable electrode rod 9, and a coil portion 13a at the center of curvature of the coil portion 13a. The provided disk-shaped attachment portion 13b and the attachment portion 13b and the coil portion 13
The coil electrode 13 constituting a part of the movable electrode 15 consisting of the radial arm portion 13C connecting with the one end of the mounting portion 13b is connected to the reinforcing rod through a recess 19 formed in one end surface of the mounting portion 13b. It is fitted concentrically to the protruding end of 8, and
One end surface of the movable electrode rod 8 and the inner end surface of the movable electrode rod 8 are hermetically joined by brazing and attached to the inner end portion of the movable electrode 9.

The coil electrode 13 electrically connects the contact electrode 12 and the movable electrode bar 9, which are electrically insulated and joined to the inner end of the movable electrode bar 9, and uses a loop-shaped current flowing through the coil electrode 13 to A through hole 20 parallel to the movable electrode rod 9 is bored at the other end of the coil portion 13a, and the coil electrode 13 and the contact electrode 12 are formed in the through hole 20 to generate a vertical magnetic field. The axial connection conductor 21 that connects the
The base of is inserted.

Four circular portions 22 are concentrically bored on the other end surface of the attachment portion 13b of the coil electrode 13, and a first annular portion forming a part of the spacer 11 is provided in the recessed portion 22. The base of the spacer 23 is fitted and integrally soldered.

The first spacer 23 is for electrically insulating the contact electrode 12 and the movable electrode bar 9, and for connecting and supporting the contact electrode 12 to the movable electrode bar 9 while appropriately separating the contact electrode 12 from the coil electrode 13. The body is provided with a gas vent hole 24 for brazing while degassing in a vacuum furnace.

Further, a coil electrode 1 is provided near the base of the first spacer 23.
A second spacer 25 formed in the shape of a disk having a diameter suitably smaller than that of the second spacer 25 is integrally fitted with the other end surface of the mounting portion 13b of the coil electrode 13 at a suitable distance therefrom.

The second spacer 25 is for reinforcing the support of the contact electrode 12, and has a gas vent hole 26 bored in its body like the first spacer 23, and has a contact electrode 12 in its outer periphery. An annular protrusion 25a protruding toward the electrode 12 is integrally molded.

The annular protrusion 25 a of the second spacer 25 is fitted into a circular first recess 27 formed on the opposing back surface (lower surface in FIG. 3) of the contact electrode 12 and is integrally brazed. There is.

Further, in the center of the first recess 27, a circular second recess 28 is provided.
is bored, and the end of the first spacer 23 is fitted into the second recess 28 and is integrally brazed thereto.

The contact electrode 12 is electrically connected to the coil electrode 13 by brazing or joining the end of the connection conductor 21 to a connection recess 29 formed on the outer periphery of the opposite back surface. A flat circular contact portion 12a provided at the center of the opposing surface (upper surface in FIG. 3) and contact portion 12a
It is provided in the shape of a cap-shaped disk having approximately the same diameter as the coil electrode 13, which is made up of a sloped portion 12b on the outer periphery of the coil electrode 13.

Also, in the figure, 30 is a coil support member that supports the coil electrode 13, and is made of austenitic stainless steel like the spacer 1, and is formed into a disc shape with a suitably smaller diameter than the outer diameter of the coil electrode 13. The movable electrode rod 8 is integrally fitted with the inner end thereof, and its body is provided with a plurality of through holes 31 extending in the axial direction.

The movable electrode 15 has been described in detail above, but the fixed electrode 14
Since it has almost the same configuration as the movable electrode 15, the same reference numerals are given to the constituent members that perform the same functions as the movable electrode 14, and the explanation thereof will be omitted.

As described above, the present invention arranges a pair of electrode rods facing each other in a vacuum container so that they can move toward and away from each other, and a pair of contact electrodes made of a high-resistance material are made of a high-resistance material. In a vacuum breaker in which each of the electrode rods and each of the contact electrodes are connected via a coil electrode that is disposed close to the outer periphery of the opposing back surface of each of the contact electrodes, the spacer is A first spacer formed in an annular shape that connects each of the electrode rods and the contact electrode at the center thereof, and a second spacer formed in a disk shape that fits into the first spacer, Since the annular protrusion is integrally molded on the outer periphery of the second spacer and the annular protrusion connects and supports the vicinity of the outer periphery of the contact electrode, the contact area of the spacer bonded to the contact electrode and the electrode rod can be reduced. .

Therefore, the current shunted to the spacer is reduced, and the longitudinal magnetic field generated by the coil electrodes becomes stronger, making it possible to improve the insulation capacity.

Further, by providing the second spacer, it is possible to reliably and firmly support the contact electrode with respect to the electrode rod.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the vacuum breaker according to the present invention, Figure 2 is a schematic diagram of the vacuum breaker according to the present invention;
The figure is an explanatory plan view with a part of the main part cut away, and FIG. 3 is a sectional view taken along the line III--III in FIG. 2. 5... Vacuum container, 7, 9... Electrode rod,
11... Spacer, 12... Contact electrode, 13... Coil electrode, 23... First
Spacer, 25...Second spacer, 25a...
...Annular protrusion.

Claims (1)

[Scope of utility model registration request] A pair of electrode rods 7 and 9 are arranged facing each other in the vacuum container 5 so that they can approach and separate from each other, and a pair of contact electrodes 12 and 12 that come into contact with and move away from each other are connected to the inner ends of each electrode rod 7 and 9 with high resistance. A coil electrode 13 in which each of the electrode rods 7 and 9 and each contact electrode 12 are arranged close to the outer periphery of the opposite back surface of each contact electrode 12, and is provided by joining with a spacer 11 made of a material interposed therebetween.
In the vacuum breaker, the spacer 11 is connected to each of the electrode rods 7, 9 and the contact electrode 1.
2, which is formed in an annular shape and joins at its center.
A spacer 23 and a disk-shaped second spacer 25 that fits into the first spacer 23 are provided, and an annular protrusion 25a is integrally molded on the outer peripheral edge of the second spacer 25. A vacuum breaker characterized in that the vicinity of the outer periphery of the contact electrode 12 is bonded and supported by the protrusion 25a.