JPS62165829A - 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 [Field of Industrial Application] This invention relates to a circuit breaker having a pair of electrical contacts.

[Conventional technology]

FIGS. 8 to 10 are cross-sectional views of conventional circuit breakers, each showing different operating states. In the figure, (1) is a cover, (2) is a base, and the cover (1) and the case (2) constitute a housing (3). (
4) is a fixed contact, which has a fixed conductor (5), has a fixed contact (6) at one end, and an outer conductor (not shown) at the other end.
It has a terminal section so that it can be connected to.

(7) is a movable contact, which has a movable conductor (8), and one end of which has a movable contact (9) opposite to the fixed contact (6).

αO is a movable contact device, and αυ is a movable contact arm, which is fixed to the crossbar and is opened and closed when each pole is spaced. 03 is an arc extinguishing chamber, and an arc extinguishing plate σ is held by a side plate αG. αQ is a toggle link mechanism, and upper link σ
It consists of force and lower link (g). Above link (1
7) One end is connected to the frame member 0, and the other end is connected to one end of the lower link (g) by the shaft (1) and Cυ. The other end of the lower link (G) is connected to the movable arm (6) of the movable contact device α0. (2) is the tilting type operation handle, the handle is the operating spring, and the toggle link mechanism 3
It is stretched between the axis Qυ of No. 6 and the operation handle (A). (C) and (C) are thermal and electromagnetic trip mechanisms, respectively, and when activated, they are bimetallic (4
) and a movable iron core to rotate the trip bar (c) counterclockwise. (4) has one end locked to the trip bar and the other end
This is the latch that locks it in place.

When the operating handle (A) is tilted to the closing position with the Freddle 00 locked to the latch handle, the toggle link mechanism α is extended, the shaft ■υ is locked to the Freddle 00, and the movable contact (9
) is joined to the fixed contact (6). This state is shown in FIG.

Next, when the operating handle is tilted to the open position, the toggle link mechanism α→ is bent, and the movable contact (9) changes to the fixed contact (6).
), and the movable arm αυ is locked to the fredl shaft (7). This state is shown in Figure @9.

In addition, if an overcurrent flows through the circuit in the closed circuit state shown in Fig. 8 above, the thermal force trip ttfflt (c) or the electromagnetic trip mechanism (c) will operate to release the engagement between the freddle 0 flaw and latch 4. 0 scratches on the Fredol axis (1
) and is stopped by the stopper '@OD. At this time, since the connection point between the fredle αI and the upper link Q″i) crosses the line of action of the actuation spring (a), the toggle link mechanism αQ is bent by the spring force of the actuation spring (a), and the crossbar According to (6), automatic shutoff is performed in conjunction with each pole. This state is shown in FIG.

Next, the arc oscillation that occurs when the circuit breaker interrupts the current will be explained.

Now, when the movable contact (9) and the fixed contact (6) are in contact, the power is transferred from the power source 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, an arc is generated between the fixed and movable contacts (9), and the fixed and movable contacts (6)) (
9) An arc voltage is generated during the interval. This arc voltage increases as the separation distance between the fixed contact (6) and the movable contact (9) increases, and at the same time the arc voltage (
) is attracted by the magnetic force and extends in the direction of the arc-extinguishing plate α→, so it further rises. In this way,
The arc current reaches the current zero point, extinguishes the arc, and completes the interruption.

[Problem that the invention seeks to solve]

With conventional circuit breakers, the arc voltage at the zero current point does not rise, and the current/flow breaker arc is near the contacts, so insulation recovery near the contacts where the insulation distance is short is slow.
For this reason, it is difficult to increase the voltage.

An object of the present invention is to provide a circuit breaker that can easily promote higher voltage.

[Means for solving problems]

In the circuit breaker according to the present invention, an arc runner is provided in a fixed contact, a second arc extinguishing plate is arranged at an angle with respect to a conventional first arc extinguishing plate, and the second arc extinguishing plate The plate is positioned further away from the tip of the movable conductor when opened.

[Effect]

In this invention, the second arc-extinguishing plate extends the arc just before the current zero point above the movable contact and covers the arc voltage at the current zero point. At the same time, the second arc extinguishing plate moves the arc foot to the tip of the movable contact. Due to the arc runner of the one-way fixed contact, the legs of the arc on the fixed contact side also move away from the contact, speeding up insulation recovery in the space near the contact where the insulation distance is short. By these effects, 74 voltage cut-off is achieved.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure shows the configuration of the main parts of the circuit breaker according to the present invention, and the same parts as those of the conventional circuit breaker are given the same reference numerals and the explanation thereof will be omitted. In the figure, (to) is an arc runner fixed to the fixed conductor (5), and extends from the fixed contact (6) to the base end side. ■ is a second arc-extinguishing plate, and this second arc-extinguishing plate (b) is almost perpendicular to the first arc-extinguishing plate 0, and extends above the tip of the movable conductor (8) when opened. They are located at a distance.

Next, the operation will be explained. Contact (9) e (6
) is elongated in the direction of the first arc-extinguishing plate Q4 under the magnetic force of the first arc-extinguishing plate a<. The upper half of the extended arc can be subjected to the action of the second arc-extinguishing plate (2). This action becomes a force that pulls the upper half of the arc toward the second arc-extinguishing plate (b). This force drags the arc on the movable contact (9) and easily moves it to the tip of the movable conductor (8).

The arc foot on the fixed contact (6) moves to the arc runner).

At the current zero point, the arc is caused by the first and second arc-extinguishing plates α
It is stretched in the Φ, 041 direction. Second arc extinguishing plate (
B) is located in the h direction from the tip of the movable conductor (8), and since there is a large space for the arc to extend, the arc length is longer, a high arc voltage is generated, and high voltage interruption is facilitated. On the other hand, since there is no arc foot on contact (9) e (6),
Insulation recovery proceeds rapidly in the space around this area, where the insulation distance is short and dielectric breakdown is most likely to occur. As a result, dielectric breakdown after the current zero point is less likely to occur. The above two effects facilitate high voltage interruption.

In the above embodiment, the movable conductor (8) has a simple shape, but as shown in FIG. As shown in the figure, a groove (92) may be provided near the tip of the movable conductor (8). By shaping the current flow at the tip of the movable conductor (8), these can promote the action of the second arc-extinguishing plate (2) which pulls the arc upward.

In addition, in the configuration shown in FIG. 4(A), the planar shape of the second arc-extinguishing plate (■) may be U-shaped (see FIG. 4(9)), and the bottom of the 0-shaped notch (84a) A slit (340) may be provided as shown in Figure (C). In this case, the bottom of the 0-shaped notch (84a) may be positioned above the position of the tip of the movable conductor (8) when opened.

Furthermore, the tip end of the fixed conductor (5) is shaped into a U shape as shown in Figure 5 ii! ! A structure that exerts magnetic repulsion may also be used.

Furthermore, as shown in FIG. 6, the angle θ formed by the first arc-extinguishing plate α and the second arc-extinguishing plate ■ does not have to be perpendicular.

Further, as shown in FIG. 7, the first arc-extinguishing plates α may be arranged in a fan shape with respective angles.

〔Effect of the invention〕

As described above, according to the present invention, the second arc extinguishing plate is located above the position of the tip of the movable contact when opened and has an angle with respect to the first arc extinguishing plate, which is the same as the conventional one. By arranging the arc plate and further installing the arc runner on the fixed conductor, a circuit breaker capable of interrupting high voltage can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of essential parts showing an example of a circuit breaker according to the present invention, and FIGS. 2 to 7 are block diagrams showing other embodiments of the present invention. Figure (4) is a plan view of the second arc-extinguishing plate, and Figure (C) is a plan view showing another modification of the second arc-extinguishing plate. FIGS. 8 to 10 are cross-sectional views showing conventional circuit breakers. (4) is a fixed contact, (5) is a fixed conductor, (6) is a fixed contact, (7) is a movable contact, (8) is a movable conductor, (9)
is the movable contact, α is the first arc extinguishing plate, (2) is the arc, (
(to) is the arc runner, the trowel is the second arc extinguishing plate, (84a)
is notch, (91) is arc horn, (92) is groove, (8
40) is a slit, and θ is an angle. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (7)

[Claims] (1) In a circuit breaker equipped with a pair of movable and fixed contacts consisting of a contact point and a conductor, and a first arc-extinguishing plate that extinguishes an arc generated when both contacts are opened, an arc occurs in the fixed conductor. A runner is provided, and a second arc-extinguishing plate having an angle with respect to the first arc-extinguishing plate is provided near the tip of the movable contact when opened, and this second arc-extinguishing plate is movable when opened. A circuit breaker characterized by being located above the tip of a contact. (2) The circuit breaker according to claim 1, wherein the movable contact has an arcing horn at its tip. (3) The circuit breaker according to claim 1, wherein the movable contact has a groove at its tip for adjusting the direction of current flow. (4) The circuit breaker according to claim 1, wherein the fixed contact has a U-shaped tip end side of the fixed conductor. (5) The circuit breaker according to claim 1, wherein the second arc-extinguishing plate has a U-shaped planar shape. (6) The circuit breaker according to claim 5, wherein the second arc-extinguishing plate has a slit at the bottom of the U-shaped notch. (7) The circuit breaker according to claim 1, wherein the first arc-extinguishing plates are arranged non-parallelly to each other and have a fan-like shape as a whole.