JPS59186223A - Circuit breaker - 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] This invention relates to a circuit breaker.

Note that the circuit breaker as used in this invention refers to a device that generates an arc within a container, usually a small container.

Figures 1 to 3 are cross-sectional views showing conventional circuit breakers.
Each shows a different operating state.

(1) is a cover, (2) is a base, and the cover (1) and base (2) constitute a container (3). (4) is a fixed contact, and a fixed contact (6) is attached to one end of the fixed conductor (5).
), and the other end is a terminal portion to be connected to an external conductor (not shown). A movable contact (7) has a movable contact (9) at one end of a movable conductor (8) opposite to a fixed contact (6)K. (10) The l'i movable contact device, al) is a movable arm, which is fixed to the crossbar (12) and configured to open and close each pole at the same time. (13
) is the arc extinguishing chamber, and the arc extinguishing plate (14 is held by the side plate (15).06) is a toggle link mechanism that connects the upper link (17).
1 and the lower link (1, 8+).One end of the upper link (17) is attached to the fredle (19), and the other end is attached to one end of the lower link 08), respectively, with the shaft (20) + (21).
are connected to each other. The other end of the lower link (18) is connected to the movable arm (11) of the movable contact device (10).

Reference numeral (22) is an up/down operation handle, and reference numeral (23) is an operating spring, which is stretched between +il+ (21) of the toggle link mechanism 06) and the operation handle (22). C2A
J, (25+) are thermal and electromagnetic tripping mechanisms, respectively, which, when activated, rotate the retrieval bar (28) counterclockwise by a bimetal (2G) and a movable iron core (a), respectively. (2)) has one end locked to the trip bar (28) and the other end of the fredle (1
, 9).

When the operating handle (22) is tilted to the closing position with the fredle (19) locked to the latch (5)), the toggle link mechanism 06) extends, and the shaft (2D) is locked to the fredle (19), opening the movable contact. (9) is connected to the fixed contact (6). This state is shown in Figure 1. Next, when the operating handle is tilted to the open position 16, the toggle link mechanism (1G) is bent and the movable contact (9) is opened by the fixed contact (6), and the movable arm (11) is locked to the fredl shaft (30). This state is shown in FIG. Furthermore, if an overcurrent flows through the circuit in the closed state shown in Figure 1, the thermal tripping mechanism (25) or the electromagnetic tripping mechanism (25) will operate.
9) and the latch (29) are released, the fredle (19) rotates clockwise around the fredle shaft side and is locked to the stopper shaft (3).

Since the connection point between the fredle (19) and the upper link (17) crosses the line of action of the above-mentioned operating spring (■), the toggle link 4m ## (16) is bent by the spring force of the operating spring (23) and the crossbar is bent. (12) Automatically performs 117 shots in conjunction with each pole. This state is shown in FIG.

Next, we will explain the behavior of the arc that occurs when the circuit breaker interrupts the current.

When the movable contact (9) and fixed contact (6) are in contact with each other, the power is transferred from the power supply side to the fixed conductor (5).
), fixed contact (6), movable contact (9) and movable conductor (
8) and is sequentially supplied to the load side. In this state, when a large current such as a short circuit current flows through this circuit, the movable contact (9) is separated from the fixed contact (6) as described above. At this time, the fixed and movable contacts (6),
(An arc (proverb) is generated between the fixed and movable contacts (61 and (9)), and an arc voltage is generated between the fixed and movable contacts (61 and (9). This a is attracted by magnetic force in the direction of the arc extinguishing plate (14) and expands. In this way, the arc current reaches a flow zero point and extinguishes the arc, completing the interruption.However, this injected beautiful arc energy is ultimately converted into heat. Although it completely escapes out of the container in the form of energy, it transiently increases the temperature of the gas inside the limited container, which in turn causes a sudden increase in gas pressure.This causes the circuit to break. There was a risk of damage to the insulation inside the circuit breaker and an increase in the amount of sparks emitted to the outside of the circuit breaker, leading to power short-circuit accidents and destruction of the circuit breaker itself.

This invention was made in view of the above circumstances, and includes a vertical surface part formed at the tip of the arc travel path in an electric contact having an arc travel path formed therein, and an opposing wall surface part formed at the rear end of the arc extinguishing plate. By configuring the contacts to face each other with a specific area relationship, the arc generated between the contacts can be quickly commutated to the desired position, improving the breaking performance and suppressing the internal pressure. The purpose is to provide a circuit breaker that can suppress wear and tear.

An embodiment of this optical system will be described below with reference to the drawings.

FIGS. 4 and 5 show the configuration of essential parts in an embodiment of the circuit breaker of the present invention.

In the same figure, (ioi) is one of a pair of venting contacts, for example, a movable contact, and the movable conductor (102
) and a movable contact point (103) fixed to the tip of the movable conductor (102) by brazing or caulking means. (104) is a pressure reflector that covers the movable conductor (102) around the movable contact (103), and this is made of a high resistance material that also has high resistivity as the movable conductor (102).

The high resistance materials constituting the pressure reflector (104) include organic or inorganic insulators or high resistance materials such as nickel iron 9 copper nickel, copper manganese, copper manganin, iron-carbon, iron nickel, and iron chromium. . The pressure reflector (104) can be formed by directly coating the movable conductor (102) with the above-mentioned material using a plasma jet spraying method, or by gluing a molded material using the above-mentioned material onto the movable conductor. It can be easily formed by tightening method. According to the above-mentioned covering means, it is easy to manufacture and inexpensive, and the increase in weight on the movable contact (101) side is suppressed, the moment of inertia is reduced, the opening speed is reduced, and the arc voltage is reduced. There are benefits that can be enhanced. (105)
is an arc running path formed in the movable contact (101), which extends from the movable contact (103) in the arc moving direction (direction of arrow a). This arc running path (105)
The pressure reflector (104) is also highly conductive, and here the pressure reflector (104) has a notch (104).
a) and is composed of a movable conductor portion exposed here. At the tip of the arc traveling path (105) in the arc moving direction, there is a surface portion (tosa
) is formed.

Among the plurality of arc extinguishing plates (106) to (110) (Fig. 6), the arc extinguishing plate (106) corresponding to the movable contact (101) in the open position has its rear end along the arc travel path. (105) is bent to face the vertical surface portion (105a) to form an opposing wall surface portion (106a).

The area of the vertical surface portion (105a) is set to be larger than the area of the opposing wall surface portion (106a). That is, the area of the vertical surface portion (105a) is 81, and the area of the opposing wall surface portion (105a) is 81.
Letting the area of 06a) be S, the relationship is S, > S.

On the other hand, as shown in FIG. 6, the fixed contact (111) also has a fixed conductor (112) and a fixed contact (113), and is provided with a pressure reflector (114) and an arc travel path (115) similar to those described above. The area relationship between the vertical surface portion (115a) at the tip of this arc traveling path (115) and the opposing wall surface portion (110a) at the rear end of the arc extinguishing plate (110) is also similar to that on the movable contact (101) side. are set the same way.

Next, the operation of the above configuration will be explained with reference to FIG.

When the movable contact (101) and the fixed contact (111) are separated due to the occurrence of fault current, etc., the movable and fixed contact (10
3), Ark country occurs between (113). The arc (32) then receives the following action. Pressure reflectors (104) of said movable and fixed contacts (101), (ill).

(114) has a high resistance, the expansion of the legs of the arc (32) is suppressed, and the positive column part reduces the sound pressure on the surfaces of the pressure reflectors (104) and (114) using the explosive force of the arc itself. It is narrowed down by causing an upward movement, and is further attracted and driven toward the arc extinguishing plates (101) to (110) by the variable distortion magnetic fields of the F arc extinguishing plates (101) to (110). Due to these functions, the shear voltage increases rapidly.

On the other hand, the pressure reflectors (104) and (114) have arc-extinguishing plates (10
6) - (110) are arranged so that the side opposite to the arrangement side is closed, so the arc mark) remains the pressure reflector (104) even if the arc voltage increases.

It cannot move in the direction in which (114) is closed, but moves along arc travel paths (105) and (115). Therefore, the legs of arc (321) are contacts (103), (113
) away from the arc running path (105), (115)
The current flows to the vertical plane portions (105a) and (115a) of the furthest house. Since the arc (32) originally has the property of blowing out in a direction perpendicular to the plane that makes up its legs, the arc (32) at the time of commutation assumes a posture as shown in Figure 6, and the arc extinguishing plate (10
6) Each opposing wall surface portion (106a) of (110).

(110a), and then each arc extinguishing plate (106)
It is divided at ~(110). In other words, since the arc (32) is completely cooled by contacting the arc extinguishing plates (106) to (iio), the rise in internal pressure due to the generation of the arc is suppressed. Arc (3
2) is removed from the contacts (103) and (113), thereby suppressing unnecessary wear and tear on the contacts (103) and (113).

In particular, the area of the opposing wall portions (106a) and (110a) of the arc extinguishing plates (106) and (110) is also larger than the area of the arc running path (105).

(115) Each vertical surface part (105a), (115a)
Since the area of is set large, when the arc (32) transfers from the vertical surface portions (105a), (115a) to the opposing wall surface portions (106a), (116a), the contact points (103), (113) Since the arc voltage between the two electrodes further increases and the current limiting effect is promoted, the above effect can be more reliably achieved.

In the above embodiment, the configuration of the main part of the present invention is explained as an example in which it is applied to both the movable and fixed contacts (101) and (111).
, (111) may be applicable.

Further, the vertical one-page surface portions (105a) and (115a) at the tips of the arc running paths (105) and (115) are constructed from parts of the movable and fixed conductors (102) and (11, 2), respectively. However, this vertical surface part (105a
), (115a) i4 Above possible: rth and fixed conductors (102), (112) can also be constructed with a separate good conductor.

Ma/ζ, the movable contact (101) and the fixed contact (11)
Even if 1) is configured with a repulsive type contact that opens by electromagnetic repulsion, the same effect as the above structure can be achieved.

As described above, in the present invention, a vertical surface portion is formed at the tip of the arc travel path in an electric contact having an arc travel path, and the area of the opposing wall surface portion corresponding to this is formed at the rear end of the arc extinguishing plate. In addition, by setting the area of the vertical surface portion to a certain value, it is possible to provide a circuit breaker that improves breaking performance, suppresses internal pressure, and ensures a long life of the contacts.

[Brief explanation of drawings]

Figures 1 to 3 are cross-sectional views of a conventional circuit breaker in different operating states, Figure 4 is an exploded perspective view of the main parts of a circuit breaker according to the present invention, and Figure 5 is an exploded perspective view of the circuit breaker according to the invention. FIG. 6, a sectional view of the main part, is an explanatory diagram of the operation of the circuit breaker of the present invention. t32)...Arc, (101), (111)...
- Electrical contact, (102). (112)...-conductor, (10,3), (113)...
・Contact points, (104), (114)...pressure reflector, (
105), (115) ---Arc running path, (10
5a), (115a)...vertical surface portion, (106) to (
110)...Arc-extinguishing plate, (106a), (110a)-
= Opposing wall surface portion, Sl, - Area of vertical surface portion, S2...
Area of opposing wall. Note that the same reference numerals in the figures indicate the same or similar parts. Agent Masuo Oiwa (2 others) Figure 3 Figure 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) At least one pair of electric contacts consisting of a conductor and a contact rod fixed to the conductor for opening and closing operation, and a plurality of extinguishers made of a good magnetic conductor to cool and extinguish the arc generated between the contacts. A pressure reflector is formed on at least one of the arc plate and the paired electric contact and is made of a high-resistance material that has a high resistivity as well as the conductor and covers the area around the contact of the conductor, and the pressure reflector is surrounded by the pressure reflector. an arc traveling path extending from the contact point in the arc moving direction and having higher conductivity than the pressure reflector, and forming a vertical surface portion substantially perpendicular to the arc traveling path surface at the tip of the arc traveling path in the arc moving direction. Then, at the open position of the electric contact having the arc running path, an opposing wall portion located at the rear end in the arc movement direction and facing the vertical surface portion is formed on the arc extinguishing plate corresponding to the opening position of the electric contact having the arc travel path, and A circuit breaker characterized in that the area of the vertical surface portion is set to be larger than the area. (2) The circuit breaker according to claim 1, wherein the pair of electric contacts operate to open each other by electromagnetic repulsion.