JPS59157917A - 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 with improved breaking performance.

Conventionally, in a circuit breaker configured so that the direction of current flowing through the fixed contact and the movable contact is the same when closed, and the current flows in a horizontal direction, the magnetic force is strong when the current is closed. Therefore, arc drive or arc extension was insufficient. This will be explained in detail with reference to FIGS. 1 to 6.

FIG. 1 is a partially cutaway side view of the circuit breaker, and FIG. 2 is a view taken along the line 8-A in FIG. 1. In these figures,
(1) is an enclosure composed of an insulator G, (2) is a fixed contact made of a fixed conductor (3) and a fixed contact (4), and (5) is a movable conductor (6). A movable contact made by fixing the contact (7), (8) is an operating device @ part that drives the movable contact (5) to open and close with respect to the fixed contact (2), (9
) is an arc generated between the fixed contact (4) and the movable contact (7), and (101 is an arc extinguishing plate for extinguishing the arc (9)).

Next, the operation will be explained. When circuit LJP disconnector G fault current flows, the operating mechanism section (8) operates and the movable contact (
5) opens from the fixed contact (2), and an arc (9) is generated between the movable contact (7) and the fixed contact (4). This arc (9) is possible! The arc extinguishing plate (10
) direction and comes into contact with the arc extinguishing plate (10). When the arc (9) comes into contact with the arc extinguishing fiIO+, it is further subjected to magnetic attraction, is elongated, cooled, and extinguished.

A conventional circuit breaker operates almost as described above, but next, the action of the magnetic force exerted by the current flowing through the pair of contacts (2) and (5I) will be explained with reference to FIG.

FIG. 6 depicts the contact portion of FIG. 1.

In this figure, electric current 1 is flowing to the fixed conductor (3) from the cloth to the left in the figure, and electric current 4 is flowing to the movable conductor (6) as well. Now, the arc (9) generated between the movable contact (7) and the fixed contact (4) has the movable conductor (6)
An electromagnetic repulsion force called Fb is working from this point. As shown by the arrow in the figure, the direction of Fb is the direction away from the movable conductor (6), and the strength is large near the movable contact (7) and decreases as it approaches the fixed conductor (3). Become. On the other hand, an electromagnetic repulsive force ld" is acting from the fixed conductor (3), and its direction and strength exhibit characteristics completely opposite to those described above.

Therefore, the arc (9) receives driving force toward the tip of the movable conductor (6) on the movable contact (7) side, and toward the tip of the fixed conductor (3) on the fixed contact (4) side. The arc (9) that received the force in the direction either did not expand its positive column, or it was difficult to move in the direction of the arc extinguishing plate 0α, so it did not receive the sufficient cooling effect of the arc extinguishing plate 00. Therefore, the conventional structure could not provide sufficient arc extinguishing performance.This invention was developed to overcome the above drawbacks.
The purpose of the present invention is to provide a circuit breaker that has a simple structure, strengthens arc extension and drive, and improves arc extinguishing performance.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a partially cutaway side view of a circuit breaker according to an embodiment of the present invention. In this figure, the same parts as those in Fig. 1 are given the same reference numerals, so their explanation will be omitted. Also, Fig. 5 is an explanatory diagram of the fixed contact part in Fig. 4, and Fig. 6 is an explanatory diagram of the fixed contact part in Fig. 4. As shown in FIG. 5, which is a view taken along the line B-B in FIG.
A convex portion (6b) has a central axis a-a perpendicular to the central axis D-D of the conductor main portion (6a) and has a cross-sectional size that is approximately the same as the fixed contact (4). It is formed with an integral G-shaped bend, and is arranged so that the direction of the electric current 2 flowing through the convex portion (6b) is perpendicular to the electric current 1 flowing through the fixed conductor main portion (6a). . A fixed contact (4) is fixed to the tip of the convex portion (6b), and a base (11a) of an arc traveling plate (11) made of a magnetic good conductor such as iron is fixed to the side surface on the arc extinguishing plate oO) side. ing. Arc running plate (
1]) is the arc (9) generated on the fixed contact (4),
The current is commutated from above this fixed contact (4) toward the arc-extinguishing & +10) side to generate a current flowing through the main portion of the fixed conductor (6a), and a current flowing parallel to and in a different direction. It is placed in a state where it can be used. In other words, the arc running plate (
1]) are arranged to form a current path parallel to and in the opposite direction to the current flowing through the movable conductor (6) shown in FIG.

Note that caulking with rivets or spot welding is applied to fix the arc traveling plate (11) to the convex portion (6b).

In Figure 5, the fixed contact (4) and the movable contact (Figure 4)
When arc (9) occurs between ff1, this arc (
9) The electromagnetic repulsion force Fa acting on can be approximately expressed by the following equation.

μ F a == −11−−−−−− 4π(y+h) However, in the above equation, F is the current, μ is the magnetic permeability, h (Fig. 5) is the height of the fixed contact, and y (the Figure 5) shows the high arc from the fixed contact to any arbitrary point on the arc.

The above power? The force a exhibits a completely opposite characteristic to the force Fb described in Fig. 6, and is small near the movable contact (7) and small near the fixed contact (7).
4) becomes larger as it approaches, and the arc-extinguishing plate (10)
Since it is a force that acts in the direction away from the movable conductor (
The force Fb having the opposite characteristic due to 6) becomes relatively large, and the arc (9) is easily extended toward the arc extinguishing plate (]0).

Further, as shown in FIG. 5, the central axis DD of the fixed conductor main portion (3a) and the central axis o- of the convex portion (6b).

The angle θ between the two is a right angle. Conventionally, the angle θ was made acute in order to strengthen the effective force against the arc (9), but in this case, electromagnetic repulsive force acts on the movable conductor (6), reducing the contact pressure in the closed state. It was supposed to happen.

, If the angle θ is set to 90° as in this invention, the driving force of the arc (9) can be increased without reducing the contact pressure at the time of injection. is easily driven to the arc extinguishing plate Od side by increasing the fixed contact height h, but in this invention, as mentioned above, since the arc traveling plate 0υ made of a magnetic material is provided, the magnetic Due to this effect, the arc spot on the fixed contact (4) gains a driving force and becomes easier to move to the arc running plate 0υ.Furthermore, once the arc spot is commutated onto the arc running plate θη, the arc spot on the fixed contact (4) is moved to the movable conductor (6). Arc running plate Q
Since the currents flowing through the arc (9) and (1) are configured to be parallel to each other and in different directions, the arc spot is increasingly driven toward the arc extinguishing plate 00, causing the arc (9) to elongate and the arc extinguishing plate The cooling effect by QCI is increased and the arc extinguishing performance is improved. In Fig. 5, the arc traveling plate (1]) is fixed to the arc extinguishing plate 110) side of the convex part (6b) of the fixed conductor (8). However, the electric current flowing through the arc traveling plate (11) after arc commutation and the fixed conductor main portion (6a) other than the convex portion (lobe b) 7. It is clear that the fixed conductor (3) may be fixed at any position as long as the wires 3 are parallel to each other and in different directions.

As can be seen from the above description, according to the present invention, it is possible to obtain a circuit breaker with a relatively simple structure that strengthens arc extension and drive and improves arc extinguishing performance.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway side view of a conventional circuit breaker, Figure 2 is a view taken along line A-A in Figure 1, Figure 6 is an illustration of the magnetic force exerted by current, and Figure 4 is a diagram of this circuit breaker. FIG. 5 is an explanatory diagram of the fixed contact portion in FIG. 4, and FIG. 61 is a view taken along line B-B in FIG. 5. be. (2)... Fixed contact, (3)... Fixed conductor, (6
a)... Fixed conductor main part, (6b)... Convex part, (4)
...Fixed contact, (5)...Movable contact, (6)...
・Movable conductor, (7)...Movable contact, (9)...Arc (1])...Arc traveling plate, 0-0 and D-D・
...Central axis. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) Figure 1 Figure 2

Claims (1)

[Claims] (1) Consisting of a conductor and a contact fixed to the conductor,
It has at least one pair of contacts that are driven to open and close;
In a circuit breaker configured such that when a pair of contacts is closed, the currents flowing through them are in the same direction and run approximately parallel to each other, one of the conductors of the pair of contacts is fixed to the fixed conductor. Forming a convex portion having a central axis perpendicular to the central axis of the main portion of the conductor, fixing a fixed contact to the tip of the convex portion, and commutating the arc generated on the fixed contact,
A circuit breaker characterized in that the fixed conductor is provided with an arc traveling plate that generates a current parallel to and in a direction opposite to the current flowing through the main portion of the fixed conductor.