JPH0793093B2 - Switch - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a switch such as a circuit breaker or a circuit breaker having an improved performance of a circuit or a circuit breaker.

[Prior Art] FIGS. 1 to 3 are cross-sectional views showing conventional circuits and circuit breakers.
The different operating states are shown. In the figure,
(1) is a cover and (2) is a base, and the cover (1) and the base (2) form a housing (3). (4) is a fixed contact, which has a fixed conductor (5), has a fixed contact (6) at one end thereof, and has the other end connected to a terminal portion so as to be connected to an external conductor (not shown). ing. A movable contact (7) has a movable conductor (8), and a fixed contact (6) is provided at one end thereof.
Has a movable contact (9) facing to. (10) is a movable contact device, (11) is a movable contact arm, and a crossbar (1
It is fixed to 2) so that each pole can be opened and closed at the same time. (13) is an arc extinguishing chamber, and an arc extinguishing plate (14) is held by a side plate (15). (16) is a toggle link mechanism, which is composed of an upper link (17) and a lower link (18). One end of the upper link (17) is connected to the cradle (19), and the other end is connected to one end of the lower link (18) by shafts (20) and (21), respectively. The other end of the lower link (18) is connected to the movable arm (11) of the movable contact device (10).
(22) is an upright operation handle, and (23) is an actuating spring, which is stretched between the shaft (21) of the toggle link mechanism (16) and the operation handle (22). (24) and (25) are thermal and electromagnetic tripping mechanism, respectively.
The trip bar (28) is rotated counterclockwise by the bimetal (26) and the movable iron core (27). (29) is a latch having one end locked to the trip bar (28) and the other end locked to the cradle (19).

When the operating handle (22) is tilted to the closed position with the cradle (19) locked to the latch (29), the toggle link mechanism (16) extends and the shaft (21) is locked to the cradle (19). , The movable contact (9) is joined to the fixed contact (6). This state is shown in FIG.

Next, when the operation handle (22) is tilted to the open position, the toggle link mechanism (16) bends and the movable contact (9) is separated from the fixed contact (6), and the mover arm (11) moves to the cradle shaft. Locked in (30). This state is shown in FIG.

Further, in the closed state shown in FIG. 1, when an overcurrent flows in the circuit, the thermal trip mechanism (24) or the electromagnetic trip mechanism (25) operates to operate the cradle (19) and the latch (2).
9) is disengaged and the cradle (19) is
It rotates clockwise around 0) and is locked by the stopper shaft (31). At this time, the cradle (19) and the upper link (17)
Since the connecting point of exceeds the line of action of the operating spring (23),
The toggle link mechanism (1
6) bends, and the crossbar (12) interlocks with each pole to automatically turn on and off. This state is shown in FIG.

Next, the behavior of the arc generated when the circuit breaker or the circuit breaker draws a current or breaks will be described.

Now, when the movable contact (9) and the fixed contact (6) are in contact with each other, the electric power is supplied from the power source side to the fixed conductor (5), the fixed contact (6), the movable contact (9) and the movable conductor (6). 8) is sequentially supplied to the load side. In this state, when a large current such as a short circuit current flows in this circuit, the movable contact (9) is separated from the fixed contact (6) as described above. At this time, an arc (32) is generated between the fixed and movable contacts (6) and (9), and an arc voltage is generated between the fixed and movable contacts (6) and (9). This arc voltage increases as the separation distance of the movable contact (9) from the fixed contact (6) increases, and at the same time, the arc (32) is magnetized toward the arc extinguishing plate (14). It rises further because it is attracted by force and extends. In this way, the arc current reaches the current zero point, extinguishes the arc, and the break is completed.

However, conventionally, in this breaking action, the arc (32) does not move more easily than the contacts (6) and (9), and the foot of the arc (32) always exists on the contacts (6) and (9). As a result, not only is the contact (6), (9) consumed significantly, but the arc (32) is less likely to come into contact with the arc extinguishing plate (14), so cooling is also less likely to occur, and sufficient arc extinguishing capability at the current zero point is achieved. Was never obtained.

FIG. 4 shows an arc extinguishing chamber in a conventional switch.
That is, in the conventional case, the arc extinguishing chamber is formed by stacking a plurality of arc extinguishing plates (14) of the same shape.

Fig. 5 shows the arc (32) and the arc extinguishing plate (1) in the arc extinguishing chamber.
4) shows the relative relationship with. In the disconnection operation,
The arc (32) is attracted by the arc extinguishing plate (14) when the movable conductor (8) is opened and its length is extended, but at the time of a large current, spots are placed on the surface of the arc extinguishing plate (14). The arc voltage does not rise so much. Therefore, as shown in FIG. 6, although the arc voltage V increases with the current I,
It decreases as the current I decreases. This is an arc (32)
This is because the arc is not long enough and the arc (32) is not divided by the arc extinguishing plate (14). As described above, the conventional switch has a drawback in that the arc voltage at the current zero point is low, and sufficient disconnection and disconnection performance cannot be obtained.

[Summary of the Invention] The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and it is possible to greatly increase the arc voltage at the time of opening and closing and to greatly improve the breaking performance. An object of the present invention is to provide a switch which can reduce wear.

In order to achieve the above object, the switch according to the present invention,
A fixed contactor having a fixed contact, a movable contactor having a movable contact that comes into contact with and separated from the fixed contact, and a movable contactor that overlaps in the opening direction of both contacts in order to extinguish the arc generated between the two contacts. A switch having a plurality of arranged arc extinguishing plates housed in a housing, wherein the arc extinguishing plate located most in the opening direction among the arc extinguishing plates has a flat surface portion, An arc transition part bent at an angle is formed with respect to the other part of the arc extinguishing plate, and the arc transition part is formed at the tip of the movable contactor while the movable contactor moves to the final open position. The surface and the flat portion of the arc transition portion are arranged so as to face each other at an angle of 45 ° or less.

According to the switch having the above structure, when the movable contact is separated from the fixed contact, an arc is generated between the two contacts, and the foot of the arc is the arc in the arc-extinguishing plate positioned most in the opening direction of both contacts. The arc foot is formed in series between other arc-extinguishing plates that are transferred to the transition part, which increases the arc voltage and significantly improves the predetermined interruption performance. It will be.

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

7 (a) and 7 (b) show the structure of the arc-extinguishing plate (14) which is the main part of the switch according to the present invention. The arc-extinguishing plate (14) shown in the figure includes a fixed contact (6) fixed to one end of a fixed conductor (5) on the fixed contactor (4) side and a movable conductor (8) on the movable contactor (7) side. Of the plurality of arc-extinguishing plates that are juxtaposed in parallel with the movable contact (9) fixed at one end in the opening direction, the arc-extinguishing plate is located most in the opening direction, and the arc-extinguishing plate ( 14) has a flat portion of a constant area, and integrally forms an arc transition portion (141) bent at an angle x with the other portion of the arc extinguishing plate (14). However, unlike the conventional one, the other configuration is the same as the conventional one, and thus the description thereof is omitted.

FIG. 8 shows a state in which the high temperature steam (32a) is jetted by the arc emitted from the tip surface of the movable conductor (8). According to experimental observations, this high-temperature steam (32a) forms a straight line E that makes an angle of about 30 ° with respect to the normal line n standing on the tip surface of the movable conductor (8).
It is emitted particularly strongly in the space created by. This high temperature steam (32
a) constitutes the main path of the arc current, commonly called the arc core. In FIG. 8, the arc transition part (14) of the arc extinguishing plate (14) is arranged within the range of the jet stream of the high temperature steam (32a). In such a situation, the arc (32) The foot easily forms spots at the arc transition part (141). FIG. 9 shows how the spots are actually formed.

By the way, in order for the spots of the arc (32) to be surely formed in the arc transition portion (141), the inventors of the present invention have designed the tip surface (81) of the movable conductor (8) and the plane of the arc transition portion (141). It was found that the angle θ formed by and is an important factor.

That is, as shown in FIG. 10, four arc extinguishing plates (14) are stacked, the arc transition part (141) is formed on the uppermost arc extinguishing plate (14), and θ is 0 to 90 °. Change the range,
The relationship between θ and the arc voltage was investigated. In addition, the opening distance of the movable conductor (8) is 17 mm, and the energizing current depends on the short circuit.
20KA.

Figure 11 shows the experimental results at this time. The vertical axis is the sustain voltage V0 at the current zero point, and the level of this sustain voltage V0 is
It is a criterion for determining whether or not the foot of the arc (32) forms a spot on the arc transition portion (141). That is, when the foot of the arc (32) transfers to the arc transfer section (141), the arc voltage rises to about 400V all at once, and this value is always maintained until the current zero point.

As is clear from FIG. 11, the presence or absence of the arc transition phenomenon is divided when θ is approximately 45 °. That is, 0
If ° ≦ θ ≦ 45 °, the foot of the arc (32) can surely form a spot on the arc transition portion (141).
However, when θ exceeds 45 °, the transition of the arc (32) becomes extremely difficult. It is considered that this is because the current flowing through the arc extinguishing plate (14) shown by I in FIG. 9 acts as an electromagnetic repulsive force on the arc (32).

FIG. 12 is a perspective view of an arc extinguishing chamber in the embodiment of the present invention, and FIG. 13 is a front view thereof. In FIG. 13, θ is set to 0 ° ≦ θ ≦ 45 ° for the above reason. As shown in the figure, when the arc spots are formed in the arc transition part (141), the arc spots are formed in series between the plurality of arc extinguishing plates (14). The voltage rises significantly. Of course, since the arc (32) has moved to the arc transition part (141), its length has also increased.

Therefore, as shown in FIG. 14, the arc voltage V at this time does not decrease in the latter half of the arc time Ta as in the conventional case and can maintain a high voltage V0 at the current zero point. is there. As a result, the current for the latter half is remarkably limited by the high voltage, and the breaking performance at the current zero point is also greatly improved.

From the original purpose, the arc transfer portion (141) in the above embodiment is at least once contacted with the tip surface of the movable contact (7) while the movable contact (7) moves to the final open position. Naturally, must be in a position where they can face each other.

FIG. 15 shows another embodiment of the present invention, in which the movable contact (9)
The insulating material (40) is arranged around the contact tip end surface (81) side. With this structure, there is no place where the legs of the arc (32) expand except on the tip surface (81). Therefore, if the arc transition part (141) is used together, the legs of the arc (32) can be quickly moved. It is more effective because it can be moved to the tip surface (81) and transferred to the transfer portion (141).

Further, since the tip end surface (81) of the movable contactor (7) and the plane of the arc transfer portion (141) may face each other at an angle of 45 ° or less, the movable conductor (8) and the arc transfer portion (141) are opposed to each other. ) May have a relationship as shown in FIG.

Further, the shape of the arc transition portion (141) is not limited to the above embodiment, and various shapes such as those shown in FIGS. 17 and 18 are conceivable. The fixed contactor (4) may be a so-called repulsive contactor that is separated from the movable contactor (7) by receiving an electromagnetic repulsive force due to an energized current. Further, although the switch has been described as an example in the above embodiment, the invention can be applied to an electromagnetic switch that generates an arc in the housing, a current limiter, etc., in addition to the switch of the present invention.

[Effects of the Invention] As described above, according to the present invention, the arc-extinguishing plate, which is located closest to the contact in the opening direction, has the flat portion, and the other part of the arc-extinguishing plate. With respect to the arc transition portion, which is bent at a certain angle, and while the movable contact element moves to the final open position, the tip surface of the movable contact element and the arc transition portion are formed. Since it is arranged so as to face the flat part of the arc at an angle of 45 ° or less, it is possible to transfer the foot of the arc to the arc transition part of the arc-extinguishing plate when the contacts are opened. , It is possible to generate arc legs in series between other arc extinguishing plates, and therefore, the arc extinguishing force of the spots of these arc legs keeps the arc voltage at the current zero high and significantly improves the breaking performance. be able to. Further, there is an effect that the consumption of the contacts can be reduced by the transfer of the arcs from both the contacts.

[Brief description of drawings]

1 to 3 are sectional views showing different operating states of conventional circuit breakers and circuit breakers, FIG. 4 is a perspective view showing a conventional arc extinguishing chamber, FIG. 5 is a front view thereof, and FIG. FIG. 7 is a diagram showing changes in arc voltage and arc current with time, FIG. 7 (a) is a perspective view of an arc extinguishing plate in an embodiment of the present invention, and FIG. 7 (b).
Is a front view thereof, FIG. 8 is a view showing a high temperature steam jetting state by an arc, FIG. 9 is a view showing a state when an arc spot is formed at an arc transition portion, and FIG. 10 is a view showing the principle of the present invention. Figure for explaining, FIG. 11 is a diagram showing the relationship between θ and arc voltage in FIG. 10, FIG. 12 is a perspective view of an arc extinguishing chamber in an embodiment of the present invention, and FIG. 13 is a front view thereof. Fig. 14 is a diagram showing changes over time in arc voltage and arc current, Fig. 15
FIG. 15A is a front view showing another embodiment of the present invention, FIG. 15B is a plan view thereof, and FIG. 16 is a front view showing another embodiment of the present invention, FIGS. Each of the drawings is a perspective view showing another embodiment of the present invention. (3) ... Case, (4) ... Fixed contact, (6) ... Fixed contact, (7) ... Movable contact, (9) ... Movable contact,
(14) …… Extinguishing plate, (32) …… Arc, (81) …… Tip surface, (141) …… Arc transition part. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Murata 1-8 Midoricho, Fukuyama-shi, Hiroshima Mitsubishi Electric Corporation Fukuyama Works (72) Inventor Hiroshi Fujii 1-8 Midoricho, Fukuyama-shi, Hiroshima Mitsubishi Electric Corporation Fukuyama Plant (56) References: Actually open Sho 56-135647 (JP, U) Actually open 58-30254 (JP, U)

Claims (2)

[Claims] 1. A fixed contact having a fixed contact, and a movable contact having a movable contact that comes in contact with and separates from the fixed contact.
A switch in which a plurality of arc extinguishing plates, which are stacked in the opening direction of both contacts in order to extinguish the arc generated between the two contacts, are housed in a housing. Of these arc-extinguishing plates, the arc-extinguishing plate has a flat portion and forms an arc transition part bent at a certain angle with respect to the other part of the arc-extinguishing plate. Means that the movable contactor is arranged so that the tip end surface of the movable contactor and the flat surface portion of the arc transition portion face each other at an angle of 45 ° or less while the movable contactor moves to the final open position. Characteristic switch. 2. The switch according to claim 1, wherein an insulator is arranged around the movable contact of the movable contact except for the tip end surface.