JPS5826430A - 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 The present invention relates to a circuit breaker f, and in particular, to a circuit breaker with improved current-limiting performance during interruption.

FIG. 1(&) is a sectional plan view showing a general circuit breaker, and FIG. 1(b) is a side sectional view taken along the line 'b-bf of FIG. 1(a). Figure 1 (!L), ('b) Vr
- Put ~ + - Movable contact (302) and fixed contact (202)
) is closed, the current flows from fixed conductor (201) + fixed contact (202) + movable contact (so2) → movable conductor (3
(+1)17) Flows in the path.

In this state VC, when a large current such as a short circuit current flows through this circuit, the operating mechanism section (4) is activated and the movable contact (30
2) is moved R away from the fixed contact (202). At this time,
A gap A occurs between the fixed contact (202) and the movable contact (302), and the fixed contact (202) and the movable contact (302)
An arc voltage is generated. This termination voltage increases as the separation distance of the movable contact (502) from the fixed contact (202) increases. At the same time, the arc voltage is attracted and expanded in the direction of the arc-extinguishing plate (5) by the magnetic force, so the arc voltage rises roughly. In this way, the arc current reaches the current zero point. At the end, A is extinguished, and L and rupture are completed. During such critical operation, the movable contact (302) and the fixed contact (202
), a large amount of energy is generated by A in a short period of time, that is, within several milliseconds. for that,
The temperature of the gas inside the enclosure (1) rises, and the IE force also rises rapidly, but this high-temperature, high-pressure gas flows through the exhaust port (101).
) is released into the atmosphere.

The circuit breaker and its internal components operate as described in 1.
2) and the operation of the movable contact (302) will be particularly explained. Generally, arc resistance R is given by the following formula. That is, R = ρ − sag, R: resistance to resistance (2) ρ: resistance to resistance (Ω・crn) t; resistance length cm) 8: resistance cross-sectional area Cctil) However, In general, it is a large current of several μm or more and has a long length.
In the case of a short end A with a pitch of 50 or less, the end space is occupied by metal particles. Moreover, this release of metal particles occurs in a direction perpendicular to the contact surface. In addition, at the time of release, the metal particles reach a temperature close to the boiling point of the metal at the contact point. It becomes electrically conductive and expands in a direction that follows the pressure distribution in the space, flowing away from the conductor at high speed. Then, the resistivity ρ in the evening sky 1vjJ and the
It is determined by the amount of metal particles generated and the direction in which they are released. Therefore, the arc voltage is also determined by the behavior of the metal particles. Next, the behavior of such metal particles will be explained using FIG. 2.

In Fig. 2, there is J3, (2 ( ) 2) is a fixed contact, (302
) indicates a movable contact 2, and contact (202), (3
02) are contact points (202), (302
) are the opposing surfaces in case of contact, and the contact point (202),
Each Y plane of (302) is other than the opposing surface X plane・1)
Part of the contact surface and conductor surface is shown. In addition, the rings indicated by the dashed-dotted lines in the figure, contact points (202), (302)
1141 K generated lure hcn is shown on the outside, roughly, metal particle a and metal particle through, contact (202)
, (302) Schematically shows the respective metal particles emitted by evaporation from the The streamline is fil.

The metal particles a and b released from such contacts (202) and (302) rise in temperature from about 3,000°C, which is the boiling point of the conductive metal, due to the energy of the arc strain. −Take away energy from the evening space,
The temperature of the end space is lowered and the end resistance R is increased as a result. Note that the amount of energy taken away by the gold M particles a and b from the arc space is 1/2 due to the degree of temperature rise of the metal particles.
The degree of temperature rise is as large as that at the contact point (202), ('
502) metal particles emitted from &.

It is determined by the position in space and the emission path of b. L or L, the conventional circuit ML or disconnector V shown in Figure 2
In c, metal particles a emitted from near the center of the opposing surface X take away a large amount of energy from the outer space, but L
The metal particles emitted from the contact surface and part of the Y plane of the conductor surface take away less energy from the Ryo-Yuzora 1 edition than metal particles a.

In other words, in the range where the metal particles flow, a large amount of energy is taken away and the temperature of the space is lowered, thus increasing the resistivity ρ, but in the range where the metal particles flow, a large amount of energy is taken away. Because it's not there, I'm sorry.
The temperature drop in the evening space is also small, so it is not possible to increase the drop resistivity ρ, and moreover, the drop occurs from the opposing surface X plane and the gutter point surface Y plane, so the 1r27 cross-sectional area also increases. 1-5 As a result, the resistance also decreases.

Since the outflow of energy from the total amount of metal particles j/7' is balanced with the gaseous injection energy, the metal particle space generated between the L1 contacts is also If the amount of injection into It turns out that it is possible.

Roughly speaking, the major drawback of conventional contact conductors (1) is that the arc foot expands directly to the junction with the conductor, which is often provided on the Y plane. There was a risk that this heat would melt the joining member with a low melting point and cause the contact to fall off.

SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit breaker which has a high cut-off voltage, has good current-limiting performance during cut-off, and is free from contact dropout.

Embodiments of the present invention will be described below based on the drawings. Third
Figure (&) is a plan sectional view showing an embodiment of the circuit breaker according to the invention, and Figure 3 ('b) is a cross-sectional view of Figure 3 (- line b).
-bvc side sectional view. Figure 3(a).

(b) In the vc, the enclosure (1) is made of an insulator and forms the outer frame of the switchgear.
). The fixed contact (2) is composed of a fixed conductor (201) fixed to the enclosure (1) and a fixed contact (202) attached to one end of the fixed conductor (201). The movable contact (3) opens and closes with respect to the fixed contact (2), and has a movable conductor (301) that opens and closes with respect to the fixed conductor (201), and a T-seal with the fixed contact (202). A movable contact (302) is attached to one end of a μ-dynamic conductor (301). The operating mechanism section (4) opens and closes the movable contact (3). The arc extinguishing plate (5) has a movable contact (302) and a fixed contact (20
2) This is to extinguish the arc that occurs when opening. The pressure reflectors [6] and (7) are each made of diphenyl oxide resin, and each has a fixed contact (20
2) A fixed conductor (302) surrounds the outer periphery of the movable contact (302) and faces each other.
201), movable conductor (301) [attached.

Now, when the movable contact (302) and the fixed contact (202) are closed, the current flows from the fixed conductor (201) to the fixed contact (202).
02) + moving contact (302) → moving conductor (301), flowing from the power supply side to the load side. In this state VC-H,
When a large current such as a short-circuit current flows through this circuit, the operation mechanism section (4) is activated 1-, and the movable contact (302) is connected to the fixed contact (
202). When the fixed contact (20
2) 71 people are generated at the contact point (302) l-. In this completion A, as shown in Fig. 4,
The metal particles are reflected by the pressure reflectors (6) and (7) VC, and the pressure in the exhaust space becomes compensating, and the resulting atmosphere is effectively cooled and extinguished.

41iJ is a schematic illustration of the behavior of gold kA particles in the circuit breaker of FIG. 5. In Figure 4, it is '13, (
202) Kobi (302) is a pair of contacts for one eye, surrounding the entire circumference of each contact (202), (302), and at the end is a fixed conductor (201) facing AC.
, ij ■ A pressure reflector (6) on the dynamic conductor (301),
(7) is provided.

Metal particles between the contacts in such a circuit/disconnector are
It behaves like the following g).

In other words, the pressure value in the air QVc cannot be greater than the pressure value in A's own space, but it must be L or L less (
In both cases, the values are overwhelmingly 1-6 lower than in the case where the pressure reflectors (6) and +7) are not provided. Therefore, the surrounding space Q with considerably high pressure generated by the pressure reflectors (6) and (7)
It provides a force that suppresses its spread and "squeezes" Ri-A into a narrow space. In other words, the streamlines m, o of the metal particles a, o, etc. emitted from the X plane, which is the opposing surface, are squeezed into the arc space and confined. Therefore, metal particles emitted from the X plane &.

Ok″i is effectively injected into the evening space. As a result,
The large amount of effectively injected metal particles removes a large amount of energy from the arc space, which is incomparable to conventional devices, and thus cools the arc space thoroughly. Therefore, the resistivity .rho., that is, the end resistance R is increased (increased), and the end voltage is increased extremely sharply.

By the way, in this invention, the pressure reflector (6).

Since (7) is made of diphenyl oxide resin, there are the following advantages. In other words, the telekinetic pressure reflector is made of diphenyl oxide resin.
This causes the temperature to rise and decomposition gas to be generated. This decomposed gas deprives it of energy and cools it down. In addition, due to the generation of decomposition gas, the pressure on the surface of the pressure reflector increases, promoting the narrowing effect, and increasing the pressure that the pressure reflector receives, so that if this pressure is applied to the movable conductor, It is possible to increase the degree of opening. In this way, the effect peculiar to the organic material is added to the effect of the pressure reflector alone, and the end voltage can be greatly increased. In addition, since diphenyl oxide resin has excellent creep properties, it can be attached with high fixation reliability by using metal rivets or the like. Moreover, since it is highly flexible, it does not crack or break even when subjected to impact during the opening and closing operations of the birth canal, and does not generate powder. Therefore, an abnormal increase in contact temperature of 1M due to foreign matter entering between the contacts will not occur. This material exhibits high heat resistance and is characterized by minimal carbonization during arc contact. Because it can be laminated with rough glass cloth prepreg, it has strong mechanical strength, and since it adheres to the conductor, it has excellent heat conduction, and +72, which has a mechanical impact force, is extremely strong against bending force. It can be used as a reflector, and is especially suitable for circuit breakers for large-frame, large-capacity magnets.

In addition, by fixing the pressure reflector (6) i7) made of this insulator as described above, the leg of A is expanded to the Y plane LVc<<, and the contact point provided on this Y plane is generally (202), (302) and conductor (201), (
301) when Ryo-ri's foot directly touches the joint (((),
As a result, it has the advantage that there is no risk of contact falling out.

FIG. 5(a) is a side view showing another embodiment of the pressure reflector (6) iγ), and FIG. 5('b) is a plan view of the one in FIG. 5(&). That is, the pressure reflector (6) i7) shown in Fig. 3 is plate-shaped, but as shown in Fig. 5 (&) and Fig. 5 (b) E, it is made of a conductor ( Pressure reflectors 0) and (7) may be formed to cover the outer circumferences of 201) and (301').

Ma7hi, 61st Δ(&) is pressure reflector (6), (7
6(b) is a plan view of the one in FIG. 6(a). That is, the pressure reflector to), (7) - Grooves (601) and (701) are provided so that the surfaces of the conductors (201) and (301) are exposed in the direction away from the contacts (202) and (502) from one side of the mK+H point.

In this way, the sliding is completed, and A's foot is in the groove (601), (7
01), the end A touches the arc-extinguishing plate (5), and is cooled to improve I- and breaking performance.

FIG. 7(a) is a side view showing another embodiment of the pressure reflectors (6) and (7), and FIG. 7(b) is a plan view of the seventh (distribution (a)). In other words, the surfaces of -parts (801) and (901) of the conductor exposed in the groove are the same as the surface of the pressure reflector +(+1. (7)). With this configuration, it is possible to quickly move to the end, and there is an advantage that the breaking performance is improved.

As described above, according to the present invention, it is possible to obtain a safe circuit breaker which has a current limiting performance of 4 iL, which is much higher than that of the conventional circuit breaker, and which does not cause the contacts to fall off.

[Brief explanation of drawings]

FIG. 1(&) is a plan view showing a general circuit breaker, FIG. 1(b) is a sectional view taken along line bb of FIG. 1(&),
Figure 2 is a schematic explanatory diagram of the behavior of metal particles in the circuit breaker of Figure 1, Figure 3 (&) is a plan view showing an embodiment of the circuit breaker according to the present invention, Figure 3 (1) ) is the fifth
Fig. 4 is a schematic explanatory diagram of the behavior of metal particles in the circuit breaker of Fig. 3, and 5th FA (a) is a side sectional view taken along the line b-'b of the pressure reflector. Side view showing an example, Figure 5(b) is the same plan view, Figure 6(!L) V
i A side view showing still another embodiment of the pressure reflector, FIG. 6(b) is a plan view of the same, and FIG. 7g! J(a) is a side view showing still another embodiment of the pressure reflector, and FIG. 7(b) is a plan view thereof. (2)... Fixed contact, (201)... Fixed conductor -
(202)... Fixed contact, (3)... Movable contact,
(3Q1)...Movable conductor, (302)...Movable contact, (6)i7)...Pressure reflector. Note that the same reference numerals in the figures do not indicate the same or equivalent parts. Agent Shin Kuzuno (1 other person)

Claims (5)

[Claims] (1) At least one pair of electrical contacts consisting of a conductor and a contact fixed to the conductor is provided, and each of the electrical contacts is mounted on the conductor so as to surround the outer periphery of the contact, and a pressure reflector is provided. At least one of the pressure reflectors is formed of an insulating composition mainly containing diphenyl oxide resin. (2) The circuit breaker according to claim 1, wherein the pressure reflector is a coating that covers the outer periphery of the conductor. (3) The circuit breaker according to claim 1, wherein the pressure reflector is a plate member attached to the contact side surface of the conductor. (4) At least one of the pressure reflectors has a groove at one end extending from a side surface of the contact and exposing a portion of the conductor in a direction moving away from the contact. The circuit breaker according to item 2 or 3. (5) The circuit I- or disconnector according to claim 4, wherein a part of the surface of the conductor exposed in the groove protrudes to be the same as or more than the surface of the pressure reflector.