JPH0554783A - Circuit breaker - Google Patents

Abstract

PURPOSE:To quickly exhaust a high pressure gas generated at the time of opening a contact out of an equipment without dispersing the pressure. CONSTITUTION:A contact 21 is disposed near an exhaust hole 26a opened to the circumferential wall of an equipment 1 between a pair of opposed wall surfaces formed in the equipment 10. The exhaust hole 26a and the contact 21 are provided in different positions along the circumferential wall of the equipment 1. A guide cover 27 enclosing the passage extending from the contact 21 to the exhaust hole 26a together with both the wall surfaces and partitioning a contact tripping device 20 from the passage is provided between both the wall surfaces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker having an exhaust hole formed in a peripheral wall of a body for discharging high-pressure gas generated inside the body when a contact is opened.

[0002]

2. Description of the Related Art Generally, a circuit breaker is designed to forcibly open the contact to protect the main circuit when an abnormal current passes through the main circuit with the contact inserted.
In order to discharge high pressure gas such as arc gas generated when the contact is opened to the outside of the container, an exhaust hole is formed in the peripheral wall of the container near the contact. In the vicinity of the contacts, it is usual to arrange a member for extending the arc generated when the contacts are opened to extinguish the arc in a short time, and a terminal plate connected to the fixed contacts among the contacts. Therefore, the contact points and the exhaust holes are provided at different positions along the peripheral wall of the body.

[0003]

By the way, since the contact and the exhaust hole are provided at different positions along the peripheral wall of the body, the high pressure gas generated together with the arc when the contact is opened is exhausted. There is a problem that the pressure is not dispersed quickly because the pressure is dispersed inside the container until it is discharged from the hole. Further, since such a high-pressure gas is ionized by the arc or contains a pyrolysis gas of surrounding members, it may adversely affect the contact trip device, and is further melted or carbonized by the arc. Droplets may adhere to the contact trip device and adversely affect it.

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and enables high-pressure gas generated at the time of contact opening to be quickly discharged from the body without dispersing pressure.
Moreover, it is an object of the present invention to provide a circuit breaker in which high-pressure gas or droplets generated when the contacts are opened prevent the contact trip device from being adversely affected.

[0005]

According to the invention of claim 1, in order to achieve the above-mentioned object, a main electric path in which a contact is inserted is passed between a pair of wall surfaces formed inside the body and facing each other. In a circuit breaker with a contact trip device that forcibly opens the contact when an abnormal current is detected, and the contact is placed near the exhaust hole that opens in the peripheral wall of the body between both walls, the peripheral wall of the body A contact cover and a guide cover are provided between the two wall surfaces, which are provided at different positions along the contact point and the exhaust hole, and surround the path extending from the contact point to the exhaust hole with both wall surfaces to separate the contact trip device and the path. -ing

According to the second aspect of the present invention, the guide cover is provided with mounting projections fitted in the holding grooves formed on the both wall surfaces along the opening surface of the exhaust hole, and the mounting projections are made of a flexible material. At the same time, the bending groove running in the direction along the holding groove is formed so as to be flexible in the width direction of the holding groove.

[0007]

According to the structure of the first aspect, the contact trip device and the guide cover for partitioning the path from the contact to the exhaust hole are surrounded by both wall surfaces. The high-pressure gas, the molten or carbonized droplets, etc., generated when the electrode is opened are guided to the exhaust hole through the path surrounded by the guide cover and both wall surfaces. As a result, the pressure of the high pressure gas does not disperse in the internal space of the body,
The high-pressure gas can be quickly exhausted from the exhaust hole, and the guide cover is interposed between the contact and the contact trip device, so that the contact pulling due to the high-pressure gas or splash generated when the contact is opened. It is possible to prevent adverse effects on the removal device.

According to the structure of claim 2, since the mounting projection of the guide cover is provided with the bending groove and the mounting projection of the guide cover is fitted in the holding groove provided on the wall surface of the body, the mounting projection can be mounted. Since it can be press-fitted into the holding groove by utilizing its flexibility, it is possible to increase the mounting strength of the guide cover to the body and to keep the guide cover in the vicinity of the exhaust hole so that high pressure gas can be discharged. It can be led to the exhaust hole without leakage.

[0009]

【Example】

(Embodiment 1) As shown in FIG. 1, a body 10 includes a base 11, a body 12, and a cover 13 each made of synthetic resin.
And a terminal 14 with a screw connected to a power source and a load at both ends of the body 12.
Is exposed. A main electric path in which a contact 21 is inserted is formed between both terminals 14. An abnormal current detection device 30 that operates when an abnormal current such as an overcurrent of about several times the rated current or a short-circuit current of several tens of times or more of the rated current flows through the main circuit in addition to the contact 21 in the main circuit. Is inserted. The body 12 is
As shown in FIG. 4, there are three chambers formed between a pair of wall surfaces facing each other, the abnormal current detection device 30 and the contact 21 are housed in each chamber, and terminals 14 are provided at both ends of each chamber. Is provided. That is, three independent electric paths are formed in the body 10 and can be used for three-phase alternating current and single-phase three-wire alternating current.

The abnormal current detection device 30 includes a coil 31 inserted in the main electric path, and an armature 33 which is attracted to an iron core 32 around which the coil 31 is wound when a large abnormal current passes through the coil 31. Equipped with. The coil 31 is shown in FIG.
As shown in FIG. 3, one end is connected to the terminal 14 and the other end is connected to the movable contact 22 via the connection wire 34. The armature 33 is pivotally attached to the other end of a yoke 35, one end of which is connected to one end of the iron core 32, and is biased by a return spring 36 in a direction away from the other end of the iron core 32. Further, inside the iron core 32, a mover (not shown) made of an oil-dumped magnetic material is movable in the axial direction of the iron core 32 and is biased in a direction away from the armature 33. It is stored. Therefore, when an overcurrent flows through the coil 31 for a long time, the movement of the mover increases the magnetic flux passing through the iron core 32, and the armature 33 is attracted against the spring force of the return spring 36. Further, when a short-circuit current flows through the coil 31, the armature 33 is attracted without moving the mover.

In the center of the three chambers formed in the body 12, an abnormal current detection device 30 and a contact trip device for forcibly opening the contact 21 when an abnormal current flows in the main circuit. A trip device 40 that constitutes 20 is housed. The trip device 40 supports the interlocking bar 42, the latch link 43, the cradle 44, and the handle 45 by the metal frame 41, and the movable contact 21a of the contact points 21a among the contacts 21 via the link 46 having the intermediate portion pivotally mounted. The movable contact 22 having the above is connected to the cradle 44, and the handle 45 and the intermediate portion of the link 46 are connected via the handle return spring 47. The interlocking bar 42 is formed so as to straddle the three chambers in the body 12, and when any of the amateurs 33 of the three abnormal current detection devices 30 is attracted to the iron core 32, the armature 32. The tip portion of 33 is rotated by kicking the kick piece 42a.

The handle 45 projects upwardly and downwardly from the upper surface of the body 10. As shown in FIG. 1, when the handle 45 is tilted to the left end side, the movable contact 21a is brought into contact with the fixed contact 21b. The contact 21 is closed. That is, in this state, the latch link 43 is engaged with the interlocking bar 42, and the cradle 44 is engaged with the latch link 43, so that the rotation of the cradle 44 is blocked. The spring force acts in the direction in which the link 46 is extended to push the movable contact 22 downward. Here, each movable contactor 2 is provided by an interlocking body 23 that is pivotally attached to the body 10 so as to extend over the three chambers of the body 12.
2 is held, and each movable contact 22 is held by a contact pressure spring 24 provided between each movable contact 22 and the interlocking body 23.
Is biased in a direction to bring the movable contact 21a into contact with the fixed contact 21b.

On the other hand, when the interlocking bar 42 rotates and the engagement state with the latch link 43 is released, the cradle 44 can freely rotate, and as shown in FIG. The spring force causes the link 46 to bend and the movable contact 22 to be pulled upward. That is, the movable contact 21a is the fixed contact 21
The contact 21 is opened apart from b. When the contact 21 is opened, the contact pressure spring 24 urges the movable contact 22 so that the movable point 21a moves away from the fixed contact 21b. Since the movable contacts 22 are connected to each other through the interlocking body 23, if the movable contactor 22 moves so that any one of the three contact points 21 is opened, the interlocking body is moved. By rotating 23, the other movable contact 22 also moves so as to open the contact 21. At this time, the handle 45 is located near the middle position of the movement range. To close the contact 21 from this state, the handle 45 may be first tilted to the right end and then to the left end. Such a trip device 40 has a known structure.

On the other hand, the overcurrent detection device 30 and the movable contact 2
Since there are three connection lines 34 that connect 2 to each other, in a three-phase alternating current or a single-phase three-wire alternating current, there is a difference in the amount of current flowing through the connection line 34 when an electric leakage occurs, resulting in imbalance. Since the current flows, the current transformer 51 detects the unbalance of the currents flowing through the three connection lines 34, thereby detecting the leakage current as an abnormal current. Current transformer 51
Is connected to the leakage detection circuit 53 mounted on the circuit board 52, and when leakage is detected by the leakage detection circuit 53, the solenoid 54 is driven to drive the above-mentioned interlocking bar 42.
By kicking the kick piece 42a provided at the key point, the trip device 40 is operated to open the contact 21. Further, when the solenoid 54 is driven, the reset button 55 is projected from the body 10 to notify that the contact 21 is opened due to electric leakage. The leakage detection circuit 53 is configured to allow an unbalanced current to flow through the connection line 34, and by pressing the test switch 56, a simulated test of the operation against the leakage current can be performed.

By the way, the contact 21 is provided at an end portion in the vicinity of the terminal 14 in each chamber of the body 12, and between the contact 21 and the interlocking body 23, a slit 25a within a range in which the movable contact 22 can move is formed. A partition plate 25 provided is provided.
The partition plate 25 is formed of an insulating material such as fiber having excellent arc resistance, and prevents the arc generated when the contact 21 is opened from wrapping around to the base side of the movable contact 22. On the other hand, the peripheral wall of the body 10 at the portion facing the partition plate 25 is open, and a plurality of exhaust holes 26a are formed in this opening.
Is closed by a perforated exhaust plate 26. Along the exhaust plate 26, the fixed contact 21b is arranged at the bottom of FIG.
The exhaust hole 26a is provided at the upper part. Exhaust plate 26
A central piece of a yoke 29 made of a substantially U-shaped magnetic body having a pair of leg pieces arranged on the side of the contact 21 is fixed to the lower part of the. The yoke 29 bypasses a part of the magnetic flux formed around the arc generated when the contact 21 is opened, thereby exerting a Lorentz force in the direction of extending the arc toward the central piece of the yoke 29. Of.

A guide cover 27 is provided above the yoke 29.
Is provided. The guide cover 27 is arranged so as to surround the path from the contact point 21 to the exhaust hole 26a together with both wall surfaces of each chamber. The upper end of the guide cover 27 contacts the upper end of the exhaust plate 26 and a part of the guide cover 27 contacts the exhaust plate 26. It is formed to face each other. Therefore, the guide cover 27 separates the contact 21 from the trip device 40. Further, mounting protrusions 27a (see FIG. 3) are provided on both sides of the guide cover 27, and the mounting protrusions 27a are fitted in the holding grooves 16 formed so as to run in the vertical direction on both wall surfaces of each chamber. Thus, the guide cover 27 is fixed to the body 10. A step portion 16a is provided at a key portion of the holding groove 16.
Is formed, and the guide cover 27 is placed on the stepped portion 16a, whereby the guide cover 27 is positioned in the vertical direction. The guide cover 27 is made of a synthetic resin such as melamine resin or trimethylpentene, and its material is selected so that the arc heat is easily extinguished by the generation of pyrolytic gas. A flexible valve plate 28 is arranged on the outer side surface of the exhaust plate 26 so as to close the exhaust hole 26a with its lower end fixed to the exhaust plate 26.

According to the above construction, when the contact 21 is opened and an arc is generated, a high pressure gas is generated due to a rapid temperature rise, ionization of gas, thermal decomposition of surrounding materials, etc., but the guide cover 27 Due to the presence of the high pressure gas, the high pressure gas is guided to the exhaust hole 26a without the pressure being dispersed, and the high pressure gas pushes the valve plate 28 to exhaust the high pressure gas. At this time, the guide cover 27
The pyrolysis gas generated from the arc enhances the action of extinguishing the arc. The droplets of the melted material and the carbide generated by the heat of the arc when the contact 21 is opened do not scatter on the trip device 40 due to the presence of the guide cover 27, and it is possible to prevent the droplets from adversely affecting the trip device 40. Of. When the contact 21 is closed, the valve plate 28 closes the exhaust hole 26a, so that dust from the outside is removed from the body 1.
It is prevented from entering 0.

(Embodiment 2) In Embodiment 1, since the mounting projection 27a provided on the guide cover 27 is mounted in the vertical holding groove 16 provided on the body 10, the guide cover 27 is formed.
May move up and down. Therefore, in the present embodiment, as shown in FIG. 5, a vertical bending groove 27b is formed in the mounting projection 27a so that the mounting projection 27a is flexible in the width direction of the holding groove 16. That is, since the guide cover 27 is made of a flexible material, the guide cover 27 is prevented from moving in the vertical direction by press-fitting into the holding groove 16 by utilizing the elasticity of the mounting protrusion 27a. Of. Further, since the guide cover 27 is in close contact with the exhaust plate 26, no gap is formed between the guide cover 27 and the exhaust plate 26, and the high pressure gas can be guided to the exhaust hole 26a without leaking. Other configurations and operations are similar to those of the first embodiment.

[0019]

According to the structure of the first aspect of the present invention, the contact trip device and the guide cover for partitioning this path are provided between both wall surfaces by surrounding the path extending from the contact point to the exhaust hole together with both wall surfaces. The high-pressure gas generated when the contacts are opened and the molten or carbonized droplets are guided to the exhaust hole through a path surrounded by the guide cover and both wall surfaces. As a result, the pressure of the high-pressure gas does not disperse in the internal space of the body, and the high-pressure gas can be quickly exhausted from the exhaust hole, and the guide cover is provided between the contact and the contact trip device. The interposition of the contact has an advantage that it is possible to prevent the contact trip device from being adversely affected by high-pressure gas or droplets generated when the contact is opened.

According to the structure of claim 2, since the mounting projection of the guide cover is provided with the bending groove and the mounting projection of the guide cover is fitted into the holding groove provided on the wall surface of the body, the mounting projection can be mounted. Since it can be press-fitted into the holding groove by utilizing its flexibility, it is possible to increase the mounting strength of the guide cover to the body and to keep the guide cover in the vicinity of the exhaust hole so that high pressure gas can be discharged. The effect is that it can be guided to the exhaust hole without leakage.

[Brief description of drawings]

FIG. 1 is a sectional view of a contact when a contact is closed.

FIG. 2 is a cross-sectional view of a contact when the contact is opened.

FIG. 3 is an exploded perspective view of a main part showing an embodiment.

FIG. 4 is a plan view showing the embodiment with a cover removed.

FIG. 5 is a perspective view of a guide cover used in another embodiment.

[Explanation of symbols]

 10 Body 16 Holding Groove 20 Contact Tripping Device 21 Contact 26 Exhaust Plate 26a Exhaust Hole 27 Guide Cover 27a Mounting Protrusion 27b Bending Groove

Claims (2)

[Claims] 1. A contact tripping device forcibly opening a contact when an abnormal current passing through a main electric path in which the contact is inserted is provided between a pair of wall surfaces formed inside the body and facing each other. , In a circuit breaker in which contacts are arranged in the vicinity of the exhaust hole opening on the peripheral wall of the body between both wall surfaces, the contact and the exhaust hole are provided at different positions along the peripheral wall of the body. A circuit breaker characterized in that a guide cover that surrounds a path leading to an exhaust hole together with both wall surfaces and separates the contact trip device and the path is provided between both wall surfaces. 2. The guide cover includes mounting protrusions that fit into holding grooves formed on the both wall surfaces along the opening surface of the exhaust hole, and the mounting protrusions are formed of a flexible material and are held. 2. The circuit breaker according to claim 1, wherein a bending groove running in a direction along the holding groove is formed so as to be flexible in the width direction of the groove.