JPH064509Y2 - Contact device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a contact device applied to a circuit breaker.

[Background technology]

The arc gas of high temperature and high pressure generated when the movable contact is opened prevents the arc from being pushed back to the mechanical part of the circuit breaker, and effectively discharges the arc gas from the exhaust plate opposite to the mechanical part to the outside of the housing. Therefore, there is a contact device in which a partition plate made of an insulator is provided in the vicinity of the movable contact of the movable contactor to partition the movable contact and the mechanism section of the circuit breaker.

However, this contact device has a drawback that the current limiting performance at the time of an abnormality such as a relatively small short-circuit current is not sufficient, and when an arc occurs, the insulation gas in the vicinity of the contact portion is deteriorated by the high temperature and high pressure arc gas. . In particular, when the arc extinguishing device is composed of an inverted U-shaped yoke, the structure is simple, but there is no cooling action, so the above-mentioned drawback is remarkable.

[Purpose of device]

The purpose of this device is to cool the arc gas,
An object of the present invention is to provide a contact device that can improve current limiting performance.

[Disclosure of device]

A contact device according to the present invention includes a movable contact having a movable contact, a fixed contact facing the movable contact, and an inverted U-shape bent from the movable contact side to the movable contact and the fixed contact. In a contact device including a yoke that extends an arc generated between the movable contact and the fixed contact, and an insulator that covers an inner surface of the yoke, the fixed contact is provided near the movable contact of the movable contact. It is characterized in that a partition plate made of an inverted U-shaped flat plate made of a magnetic material is provided across the opposite side of the contact to generate an electromagnetic force in the opening direction in the movable contact when an abnormal current flows.

According to the structure of this invention, since the partition plate is formed of a magnetic material, the high-temperature arc gas can be effectively cooled by the partition plate, and the magnetic flux due to the current of the movable contact element passes through the partition plate to cause the movable contact inside the partition plate. Since a magnetic flux interlinking with the child is generated, an electromagnetic force in the opening direction is generated in the movable contact at the time of an abnormal current, and the opening speed of the movable contact can be increased. Therefore, since the arc gas can be cooled, insulation deterioration due to carbonization due to the arc in the vicinity of the contact portion can be prevented, and the opening force of the movable contact can be increased and the driving force of the arc can be improved, so that the current limiting performance can be improved. Moreover, reverse U
The arc can be extended and extinguished by the character-shaped yoke, which simplifies the structure.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 6. That is, the contact device of this circuit breaker has the movable contact 1, the fixed contact 2, the arc extinguishing device 3, and the partition plate 4.

The movable contact 1 has a movable contact 5 at its tip. The base end portion of the movable contactor 1 is connected to a mechanism portion (not shown) of the circuit breaker, and the movable contactor 1 is opened / closed by the opening / closing operation of the handle 6, and an abnormal current detecting means such as a short circuit (Fig. When an abnormal current (not shown) is detected, the mechanism section trips and the movable contact 1 opens.

The fixed contact 2 is provided on the fixed contact 7. The fixed contact 7 is provided with a terminal screw 8 for connecting to the power source at one end, and a U-shaped cut line 7a is formed at the opposite end so that both sides are reverse U-shaped.
The drive coil 9 of the arc extinguishing device 3 is integrally formed by bending it into a letter, and the fixed contact 2 is provided between the drive coils 9. The fixed contactor 7 is fixed to the base 22 with a mounting screw 21.

The arc extinguishing device 3 is arranged near the movable contact 5 and the fixed contact 2 to extinguish the arc generated between the fixed contact 2 and the movable contact 5. The arc-extinguishing device 3 is arranged on both sides of the fixed contact 2 and generates an electromagnetic force in the opening direction in the movable contact 1 at the time of an abnormal current and a drive coil 9 for extending the arc, and is bent in an inverted U shape. The yoke 10 extends over the drive coil 9 from the side opposite to the fixed contact 2 so as to form the magnetic path of the drive coil 9, and extends the arc, and an insulator 11 coated inside the yoke 10. The yoke 10 is made of a magnetic material and is formed in an inverted U shape by the back plate 12 and the pair of side plates 13 and 14, and one of the pair of openings in the direction parallel to the back plate 12 is used as the arc entrance opening 15 and the other is formed. The exhaust opening 16 is formed, and the arc entrance opening 15 is stepped.

The insulator 11 is formed in an inverted U shape and has a yoke 1 on the outer surface.
A recess 17 into which 0 is fitted is formed, and a tongue piece 18 is formed on the side of the arc entrance opening 15 opposite to the back plate 12. As the insulator 11, a polymer material, for example, polymer pentene resin, which is heated by arc heat to generate a large amount of pyrolysis gas for compressing and cooling the arc, is selected as an example. The arc extinguishing device 3 is held and fixed by a holding plate 26 of the cover 23.

The partition plate 4 is made of an inverted U-shaped flat plate made of a magnetic material, and extends in the vicinity of the movable contact 5 of the movable contact 1 from the side opposite to the fixed contact 2 to open the movable contact 1 when an abnormal current occurs. Generate electromagnetic force in the direction. Reference numeral 20 is an inner slit. The partition plate 4 is arranged so as to be insulated from the yoke 10 via the collar 11a of the insulator 11. Both sides 25 of the partition plate 4 are supported by grooves (not shown) formed in the device base 22, and the lower surface is placed on the tongue piece 18 of the insulator 11 and insulated from the fixed contactor 7.

Reference numeral 24 is an exhaust plate having exhaust holes.

The operation will be described. In the ON state, the rated current flows through the movable contact 1 and the fixed contact 7. When an excessive current flows due to an increase in load or a short-circuit accident, the abnormal current detection means detects the abnormal current and the movable contact 1 opens, an arc is generated between the movable contact 5 and the fixed contact 2. Sometimes. FIG. 4 shows the initial state of the contact opening. At this time, the magnetic flux due to the current flowing through the movable contact 1 and the fixed contact 7 is as shown in FIG. 4 (b). That is, the magnetic flux Φ ₁ is due to the drive coil 9 of the arc extinguishing device 3 (○
The "x" mark indicates that the current flows through the drive coil 9 from the front side to the back side of the paper surface, and the "." Mark indicates that the current direction is opposite to the above. This magnetic flux passes between the movable contact 5 and the fixed contact 2, and further the yoke 10
And pass through the partition plate 4. Further, magnetic flux Φ ₂ due to the current flowing through the movable contact 1 flows through the partition plate 4 (FIG. 6). As a result, the magnetic fluxes Φ ₁ and Φ ₂ are linked with the current of the movable contact 1, so that the movable contact 1 receives an electromagnetic force in the opening direction. The movable contact 1 is instantly opened by this electromagnetic force, and at the same time, the movable contact 1 is opened with a slight delay due to the mechanical portion that started the trip opening operation.

FIG. 5 shows the contact opening state of the movable contactor 1. The arc X is driven by the following electromagnetic force and extends toward the exhaust opening 16 side of the yoke 10. That is, the magnetic flux generated around the current flowing through the movable contact 1 and the fixed contact 7 through the arc X interlinks with the arc X, and the magnetic flux generated by the current flowing through the drive coil 9 is linked by the arc X. The electromagnetic force generated by the intersection and the magnetic flux generated around the arc X flows through the yoke 10 and a part of the magnetic flux
It is an electromagnetic force caused by interlinking with the arc X when flowing between 3 and 14.

The arc X that extends inside the insulator 11 from the arc entrance opening 15 side to the exhaust opening 16 side generates thermal decomposition gas due to the heat of the arc X by the insulator 11 and compresses and cools the arc X. At the same time, the arc X extends and disappears in the vicinity of the exhaust opening 16.

Further, the arc gas generated with the generation of the arc X is prevented by the partition plate 4 from moving to the opposite side of the movable contact 5 from the arc extinguishing device 3 and flowing into the mechanism portion, and at the same time, the partition plate 4
To cool the high temperature arc gas.

According to this embodiment, since the partition plate 4 is made of a magnetic material, the high-temperature arc gas can be effectively cooled by the partition plate 4, and the magnetic flux due to the current of the movable contact 1 passes through the partition plate 4 to prevent the partition plate 4 from moving. Since a magnetic flux interlinking with the inner movable contactor 1 is generated, the movable contactor 1 at the time of an abnormal current
An electromagnetic force in the opening direction is generated in the contact opening, and the opening speed of the movable contact 1 can be increased. Therefore, since the arc gas can be cooled, the insulation deterioration due to the carbonization due to the arc in the vicinity of the contact portion can be prevented, and the opening force of the movable contact 1 can be increased to improve the driving force of the arc. Flow performance can be improved. Moreover, since the arc is extended and extinguished by the inverted U-shaped yoke 10, the structure can be simplified.

A second embodiment of this invention is shown in FIG. That is, in this contact device, the partition plate 4 is folded in two and the slit 20 is formed in a notch shape from the bent side. In this case, the width of one piece 4a of the partition plate 4 is lengthened so that its side portion 25 is locked in a groove (not shown) of the device base 22, and the width of the slit 20b of the other piece 4b is set to the width of the piece 4a. It is formed to be narrower than the width of the slit 20a.

According to this embodiment, the area of the partition plate 4 that comes into contact with the arc gas is increased, so that the cooling effect is enhanced and more carbon and molten metal powder are adsorbed, so that the insulation deterioration is more effectively prevented.

A third embodiment of this invention is shown in FIG. That is, this contact device is one in which the partition plate 4 is bent in three, and the slit 20 becomes narrower as it moves away from the movable contact 5 for each piece. Others are the same as those in the second embodiment.

[Effect of device]

According to the contact device of the present invention, since the partition plate is formed of a magnetic material, the high-temperature arc gas can be effectively cooled by the partition plate, and the magnetic flux due to the current of the movable contact element passes through the partition plate to move inside the partition plate. Since a magnetic flux interlinking the contacts is generated, an electromagnetic force in the opening direction is generated in the movable contact at the time of an abnormal current, and the opening speed of the movable contact can be increased. Therefore, since the arc gas can be cooled, insulation deterioration due to carbonization due to the arc in the vicinity of the contact portion can be prevented, and the opening force of the movable contact can be increased and the driving force of the arc can be improved, so that the current limiting performance can be improved. Moreover, since the arc is extended and extinguished by the inverted U-shaped yoke, the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a side view of a partially broken state in which a first embodiment of the present invention is applied to a circuit breaker, FIG. 2 is a perspective view of a contact device, FIG. 3 is its exploded perspective view, and FIG. Explanatory drawing showing the initial state of contact opening, FIG. 5 is an explanatory drawing showing the contact opening state, FIG. 6 is an explanatory drawing of the partition plate, FIG. 7 is a perspective view of the partition plate of the second embodiment, FIG. 8 is a perspective view of the partition plate of the third embodiment. 1 ... Movable contactor, 2 ... Fixed contact, 3 ... Arc extinguishing device,
4 ... Partition plate, 5 ... Moving contact, 10 ... Yoke, 1
1 ... Insulator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-180916 (JP, A) Actual development S59-36558 (JP, U) Actual public S44-30031 (JP, Y1)

Claims (3)

[Scope of utility model registration request] 1. A movable contact having a movable contact, a fixed contact facing the movable contact, and an inverted U-shape bent from the movable contact side to the movable contact and the fixed contact. In a contact device including a yoke that extends an arc generated between the movable contact and the fixed contact, and an insulator that covers an inner surface of the yoke, the fixed contact is provided near the movable contact of the movable contact. A contact device, characterized in that a partition plate made of an inverted U-shaped flat plate made of a magnetic material is provided across the opposite side to generate an electromagnetic force in an opening direction in the movable contactor when an abnormal current flows. 2. The arc extinguishing device has a pair of drive coils, which are arranged on both sides of the fixed contact and generate an electromagnetic force in the opening direction in the movable contactor at the time of an abnormal current and extend the arc. Contact device according to claim (1) of claim for new model registration. 3. The partition plate is formed by folding back a plurality of times,
The contact device according to claim (1), wherein the inner space is gradually narrowed away from the movable contact.