JPH11265641A - Arc extinguishing chamber for circuit breakers - Google Patents

Abstract

An object of the present invention is to provide a small-sized arc-extinguishing chamber for a circuit breaker having a self-extinguishing ability and an ability to rotate an arc. A fixed contact device (16) cooperating with a movable contact (14) and a coil (18) for rotating an arc on an annular arc migration track (32). The fixed contact device 16
It includes a plurality of contact claws 42 arranged on the outer periphery, each contact claw 42 comprising a composite metal structure, which achieves an optimal guide of the arc on said (arc migration) track (32). You.
Because the fixed contact device doubles as a main contact and an arc contact, it is possible to form a very compact arc extinction chamber at very low manufacturing costs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high dielectric strength (high die)
lectric strength)
An extinguishing chamber for a high voltage circuit breaker comprising an extinguishing device that utilizes the self-expansion of gas. Here, the arc-extinguishing chamber comprises: an enclosure of insulating material including a fixed contact device, said fixed contact device working in conjunction with a movable contact. The movable contact is located at the end of a conductive tube that can slide through one of the panels of the enclosure, and the sliding of the conductive tube causes the contact to move between a closed position and an open position. (Switch). The arc quenching chamber further includes an electromagnetic coil for rotating an arc on a contact (arc migration) track located on its front. The electromagnetic coil is fixed to the fixed contact device, thereby forming a fixed contact device module that overhangs (overhangs) on the panel opposite the enclosure. The arc extinguishing chamber further includes means for allowing the arc extinguishing chamber to communicate with the external volume of the enclosure when the contacts are released and self-expansion of the gas occurs;
The cylindrical electromagnetic coil is wound coaxially, and the fixed contact device includes a plurality of contact claws arranged on an outer periphery, thereby forming a hollow space for receiving the movable contact.

[0002]

2. Description of the Related Art In known arc-extinguishing chambers similar to the type described above, rated current flow usually occurs in the main circuit. The main circuit includes a fixed main contact and a movable main contact that separate before the arc contact opens and close after the arc contact closes. This main circuit is formed by a circuit separate from the arc circuit and is arranged coaxially around the coil or is laterally offset with respect to the arc circuit (for details see document EP-A-768). , 692). Conventional arc extinguishing chambers for circuit breakers are not suitable for substations where small dimensions are required due to their complex architecture.

In the circuit breaker disclosed in document US-A-4,431,886, the coil is permanently excited by the rated current when the contacts are closed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a self-extinguishing self-extinguishing type (self-extinguishing type) which can be accommodated in a compact substation.
-extinguishing expansion) to provide an improved arc-extinguishing chamber for circuit breakers.

[0005]

According to an arc-extinguishing chamber according to the invention, as an improvement, each contact pawl comprises a composite metallic structure, which comprises: the movable contact is in a closed position; When the permanent current (pe
a body of copper formed as a cylindrical sector for allowing a rmanent current to flow, brazed to the front side of the body of copper and located near the arc rotating (migration) track Refractory of fixed arc contacts
And a segment of ferromagnetic material brazed to a portion of said electrode and said copper body, said segment being located inside said electromagnetic coil, whereby said ( Arc migration) An optimal guide of the arc on the track is achieved.

According to the invention, the fixed contact device occupying the inner volume of the electromagnetic coil is designed to function dually as a main contact and an arc contact, so that at very low manufacturing costs very low It is possible to form a compact arc extinguishing chamber.

According to one preferred embodiment, the electrode is made of a copper-tungsten alloy and the segments are made of steel. The electrode and the segment of each contact claw are separated from the contact (arc migration) track by a small axial gap, so that when the movable contact is separated from the electrode,
An arc is generated (switched) towards the migration track and the electromagnetic coil is excited. Each of the contact claws includes a rear latch edge mounted on a centering shoulder of a conductive stud by a latch mechanism.

According to one aspect of the invention, the electromagnetic coil is connected to the conductive stud by a support arm made of copper, the support arm forming a spacer separated from the contact nail by an insulating pad. A spring having the form of a curved blade is inserted between each of the insulating pads and the corresponding contact nail.

[0009] Other advantages and features will become more apparent from the following description of one embodiment of the invention, given by way of example and not by way of limitation, with reference to the drawings, in which:

[0010]

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

FIG. 1 is a schematic sectional view of an arc-extinguishing chamber according to the present invention, showing a state where a contact is in a closed position.
FIG. 2 is a cross-sectional view similar to FIG. 1, but showing a state where the contact is in an open position.

As shown in FIGS. 1 and 2, the self-extinguishing expansion t
ype) high voltage circuit breaker
extinction chamber (extinguishi) for pole
The ng chamber 10 includes an enclosure 12. The enclosure 12 is made of an insulating material and has a high withstand voltage gas, for example, sulfur hexafluoride SF6.
Is satisfied. Inside the arc-extinguishing chamber 10, a tubular movable contact 14 is provided. Movable contact 1
4 works with the fixed contact device 16 associated with the electromagnetic coil 18 to rotate the arc. The movable contact 14 is provided at an end of an elongated tube 20 made of a conductive material. The elongate tube 20 penetrates one of the panels 22 of the enclosure 12 made of insulating material and can slide up and down in close contact. The outer end of the tube 20 closes the movable contact 14 in the closed position (FIG. 1)
And an operating mechanism (not shown) designed to move between the open position (FIG. 2).

The fixed contact device 16 is extended by a cylindrical conductive stud 24. That is, it passes through the opposite panel 26 in the longitudinal direction of the enclosure 12 and is connected to the outside by the connecting strips 28 of the poles. Because of this hollow tube 20, contact 1
As soon as 4 and 16 are separated, the arc-extinguishing chamber 10 communicates with the outer volume of the enclosure 12, thereby allowing the gas to expand on its own. An insulating enclosure 12 is formed by abutting the two half shells 12A, 12B. These shells 12
A and 12B are molded from a polymer resin having good mechanical strength and thermal resistance.

FIG. 3 is a schematic perspective view showing a coil and a fixed contact device module mounted in advance.

FIG. 4 is an elevation view of FIG.

FIG. 5 is a schematic sectional view taken along line 5-5 in FIG.

Referring to FIGS. 3-5, the electromagnetic coil 18 used to extinguish the arc is a copper conductive winding 18A stacked adjacent to each other in the longitudinal direction.
including. The conductive windings 18A are electrically connected in series by fixing screws 30, and an interlayer member 18B made of an insulating material is inserted between the conductive windings 18A. Front 3 of coil 18
1 has an arc migration track (arc migrat)
ion track) 32 is provided. This track 32
It is tubular and has an inner diameter slightly larger than the diameter of the movable contact 14. The back winding 33 opposite the front 31 is connected to the conductive stud 24 by a support arm 34.
The support arm 34 consists of a copper spacer and is separated from the inner fixed contact device 16 by an insulating pad 36. The two steel washers 38, 40 are
It is fixed to the back of the coil 18 with the insulating washer 41 interposed.

The fixed contact device 16 of the self-extinguishing arc expansion circuit breaker has three contact claws 42. These contact claws 42 have the form of a circular center, are arranged on the outer circumference and form a cylindrical hollow contact. The inner diameter of the hollow contact is substantially equal to the outer diameter of the movable contact 14 so that the movable contact can be extended and contracted at the start of the opening movement and at the end of the closing movement, respectively.

Each contact claw 42 has a spring 44 associated therewith. This spring 44 has the form of a curved blade, the convex surface of which corresponds to the insulating pad 3 of the corresponding support arm 34.
Hang by 6. Centering of these three contact claws 42 with respect to the longitudinal axis of the fixed contact device 16 is achieved by an edge 46. This edge 46
Is provided at the rear of the contact claw 42 and is mounted on the centering shoulder 48 of the stud 24 by a latch mechanism.

The coil 18 is a fixed contact device 1
6 are coaxially surrounded by a small annular gap. The pre-mounted assembly thus forms an overhanging module, which is
It is secured to the panel 26 by a nut 50 that can be accessed from outside the enclosure 12.

The structure of the fixed contact device 16 inside the coil 18 is designed to have two functions.
That is, firstly, it functions as a fixed main contact through which a permanent current flows, and secondly, it functions as a fixed arc contact for releasing the contact and switching the current to the coil 18.

FIG. 6 is a conceptual diagram showing a contact claw element of a fixed contact device.

FIG. 7A is a front view of the contact claw.

FIG. 7 (b) is a view of FIG.
It is sectional drawing along line 9.

FIG. 8 is a sectional view taken along the line 8-8 in FIG.

Referring to FIGS. 6-8, each contact claw 42 comprises a composite metal structure formed of different materials assembled by brazing. The body 52 of the contact pawl 42 is made of copper and is formed as a cylindrical sector, and carries a permanent current when the movable contact 14 is in the closed position. A copper tungsten electrode 54 is brazed to the rear of the contact claw body 52 located opposite the latch edge 46.
d) is done. This electrode 54 performs the function of a fixed arc contact and protects the fixed contact device 16 from the effects of the arc.

The inner cylindrical part of the body 52 of the contact pawl is connected to the electrode 54 by a curved intermediate member 56, whereby the closing phase of the circuit breaker is closed.
In a phase), the movable contacts 14 are made easy to insert. The segment 58, made of steel or other ferromagnetic material, is
It is brazed to the outer circumference of the two electrodes 54, thereby achieving a guide of the arc and a good distribution of the magnetic field generated by the coil 18 when the arc is switched on the track 32. The axial length of the segment 58 is
4 and extends to near the cylindrical portion of the body 52 of the contact pawl.

The operation of the arc extinguishing chamber 10 according to the present invention
It is as follows. That is, in the closed position (FIG. 1), the movable contact 14
6 and engage with the main body 52 of the contact claw made of copper to allow a permanent current to flow to obtain a rated strength of 630A. Contact pressure is applied to the contact pawl 42 by a spring 44. At this point, the coil 18 has a total current of stud 24, contact claw 42,
And flow to the movable contact 14 of the tube 20, so that it is in a non-operating state. Due to the striction forces, a compensation effect is obtained on the contacts, which keeps the contacts closed.

When a short-circuit current occurs, the tube 20 is slid upward by the operating mechanism, and the movable contact 1
4 is pulled away from the electrode 54. The movable contact 14 is located at a small axial distance from the track 32, and as soon as the movable contact 14 separates from the electrode 54, an arc is generated during this. This causes the arc to move to the migration track 32, which causes current to flow through the coil 18 and the support arm 34. This creates a magnetic field that causes the arc to rotate around the migration track 32 at high speed. At this time, no current flows through the contact claw 42. Due to the increase in temperature due to the arc, the pressure of SF6 gas in the enclosure 12 increases, so that gas passes through the tube 20 and expands the tank (not shown).
n volume). The arc disappears as soon as it is sufficiently cooled by this gas flow (FIG. 2).

According to the present invention, as described above, the fixed contact device 1 is provided inside the electromagnetic coil 18.
6 is designed to operate dually as a main contact and an arc contact, so that a very compact arc extinction chamber (extingui) at very low manufacturing costs.
shing chamber).

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an arc extinguishing chamber according to the present invention, with a contact in a closed position.

FIG. 2 is the same view as FIG. 1, but with the contacts in the open position.

FIG. 3 shows a pre-loaded coil and fixed contact device module.

FIG. 4 is an elevation view of FIG. 3;

FIG. 5 is a sectional view taken along lines 5-5 in FIG. 4;

FIG. 6 shows a contact claw element of a fixed contact device.

7A is a front view of a contact claw, and FIG. 7B is a cross-sectional view taken along line 9-9 of FIG.

FIG. 8 is a sectional view taken along line 8-8 in FIG. 7 (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Arc extinguishing chamber 12 Enclosure 14 Tubular movable contact 16 Fixed contact device 18 Electromagnetic coil 20 Elongated tube 22 Panel 24 Cylindrical conductive stud 26 Opposite panel 28 Connection strip 12A, 12B Half shell 18A Stacked in longitudinal direction Copper conductive winding 18B Interlayer member 31 Front of coil 18 Arc migration track 33 Back winding 36 Insulation pad 38, 40 Steel washer 41 Insulation washer 42 Contact nail 44 Spring 46 Edge 48 Centering shoulder 50 Nut 52 Contact nail 42 Body 54 Copper tungsten electrode 56 Curved intermediate member 58 Ferromagnetic segment

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Dominique, Selbu, Chlor, Ryu, Leo, Lagrange, France 419 (72) Inventor Philip, La Marechal, La Chapelle, Blanche

Claims (9)

[Claims] An arc-extinguishing chamber for a high-voltage circuit breaker, provided with an arc-extinguishing device that is insulated by a gas having a high dielectric strength and uses self-expansion of the gas. An enclosure (12) having a device (16), wherein said fixed contact device (16) operates in conjunction with a movable contact (14), said movable contact (14) being a panel (22) of said enclosure (12). ) Provided at the end of a conductive tube (20) slidable through one of the contacts, the slide of the conductive tube (20) being moved between a closed position and an open position of a contact. 12) and an electromagnetic coil (18) for rotating an arc on a track (32), wherein the track (32) is Provided on the front side of the magnetic coil (18), said electromagnetic coil (18) is fixed to said fixed contact device (16), so that the module which overhangs on the panel (26) opposite said enclosure (12) When the contact is separated from the forming electromagnetic coil (18) and the gas expands itself,
Communication means for allowing the arc-extinguishing chamber (10) to communicate with the outside of the enclosure (12), wherein the fixed contact device (16) is coaxial with the cylindrical electromagnetic coil (18). And a plurality of contact claws (42) arranged on the outer periphery so as to form a hollow space for receiving the movable contact (14), and each contact claw (42) of the fixed contact device (16). ) Comprises a composite metal structure comprising: a copper body (52) formed as a cylindrical sector for allowing a permanent current to flow when the movable contact (14) is in the closed position; Made of conductive material and brazed to the front end of the copper body (52) to form a fixed arc contact near the track (32). An electrode (54), a segment (58) of ferromagnetic material brazed to said electrode (54) and part of said copper body (52), said segment being inside said coil (18). Arc extinction chamber provided with a segment (58), thereby achieving optimal guidance of the arc on said track (32). 2. The arc quenching chamber according to claim 1, wherein said electrode is made of a copper-tungsten alloy. 3. The arc quenching chamber according to claim 1, wherein said segments are made of steel. 4. The track (3), wherein the electrode (54) and the segment (58) of each of the contact claws (42) are provided.
2), the arc is switched and the electromagnetic coil (1) is switched when the movable contact (14) is separated from the electrode (54).
8. The method according to claim 1, wherein the step (8) is excited.
An arc-extinguishing chamber according to claim 1. 5. A centering portion (4) of a conductive stud (24) is formed by a latch mechanism.
8) Arc extinguishing chamber according to claim 1, characterized in that it has an edge (46) mounted on it. 6. The electromagnetic coil (18) is connected to the conductive stud (24) by a support arm (34) made of copper, the support arm (34) being connected to an insulating pad (3).
6. An arc-extinguishing chamber according to claim 5, wherein the spacer formed by 6) is separated from the contact claws. 7. A curved blade-like spring (44) is inserted between each of said insulating pads (36) and a corresponding contact claw (42). An arc extinguishing chamber as described. 8. The electromagnetic coil (18) is formed by axially laminated conductive windings (18A) insulated from each other by an insulating interlayer member (18B), and the electromagnetic coil on the opposite side of the track (32). The arc quenching chamber according to claim 6, characterized in that steel washers (38, 40) are provided on the back side of the coil (18) and are fixed by fixing screws (30). 9. The movable contact (1)
The arc quenching chamber according to claim 1, characterized in that it is formed by said hollow tube (20) of 4).