CN101071701B - Circuit breaker - Google Patents

Abstract

The invention discloses a circuit breaker, which can not only prevent the partition from being damaged due to the internal pressure rise of the circuit breaker, but also connect the side of the circuit breaker including the fixed contact, the movable contact and the arc extinguishing chamber to the side of the circuit breaker including the switching mechanism and the circuit breaker. The load side of the current trip unit is isolated with a bulkhead. The circuit breaking part including the fixed contact (3), the movable contact (5) and the support frame (9) and the arc extinguishing chamber (6) are accommodated in the casing (1), and the trip mechanism including the trip lever (17) and The opening and closing mechanism (4) is accommodated in the middle cover (2), and a conductive connecting plate such as a metal connecting plate (14) is used to connect the fixed contact (3), the movable contact (5) and the arc extinguishing chamber ( 6) The circuit breaker side is isolated from the load side including the switching mechanism (4) and the overcurrent tripping device (15).

Description

circuit breaker

technical field

The invention relates to a circuit breaker, which is especially suitable for protecting a switch mechanism and an overcurrent tripping device on the load side from being damaged by high-temperature gas blown from an arc generating part.

Background technique

In low-voltage circuits, circuit breakers such as wiring circuit breakers and earth leakage circuit breakers are used to interrupt the short-circuit current or load current flowing into the load.

In this circuit breaker, it includes: a contact part provided with a fixed contact and a movable contact, a support frame that rotatably supports the movable contact, an arc extinguishing device for eliminating the arc generated by the contact part, and a drive that can The opening and closing mechanism that opens and closes the moving contact, the tripping mechanism that releases the lock of the opening and closing mechanism, and the overcurrent tripping device that detects an overcurrent and activates the tripping mechanism. These constituent parts are housed in a molded case composed of a case main body and a cover mounted thereon.

In addition, in such a circuit breaker, once a large current such as a short-circuit current is interrupted, an arc occurs between the fixed contact and the movable contact, and a high-temperature, high-voltage arc containing metal particles and resin evaporated by the heat of the arc The gas fills the interior of the circuit breaker. For this reason, sometimes it will cause damage to the switching mechanism and overcurrent tripping device, causing poor connection or tripping, or causing carbonization or adhesion of soot to the insulating container and internal molded parts, resulting in a drop in resistance and poor withstand voltage.

For this reason, in Patent Document 1, for example, a method is disclosed in which a molded case of a circuit breaker is divided into a case main body, a middle cover mounted on the case main body, and a top cover covered on the middle cover. The contact part and the arc extinguishing device composed of the contact and the movable contact are stored in the main body of the housing, and the opening and closing mechanism and the tripping mechanism are stored in the middle cover, so that the movable parts such as the opening and closing mechanism are shielded from Pollution due to melting of metallic or insulating materials due to arc heat.

In addition, the following method is disclosed in the specification and drawings of the applicant's previous application, that is, Japanese Patent Application No. 2005-50268. Insulation is reduced, and a pole partition and a middle partition are provided. The pole partition surrounds the contact part and the arc extinguishing device for each pole and isolates them from each other. The middle partition isolates the contact part of each pole and other Between the overcurrent tripping devices arranged behind.

Patent Document 1: Japanese Patent Laid-Open No. 2005-228669

However, in the method disclosed in the specification and drawings of Japanese Patent Application No. 2005-50268, the pole separator and the middle separator are integrally formed with the case main body or the middle cover by molding. Therefore, when high-temperature and high-pressure arc gas is generated when a large current is interrupted, the internal pressure rises, causing a problem that the separator is damaged. Furthermore, when the space for arranging the partitions is insufficient for the internal structure, the thickness of the partitions becomes thin, and there is a problem that it is difficult to secure the strength of the partitions.

Contents of the invention

The present invention is proposed to solve the problems existing in the above-mentioned prior art, and its purpose is to provide a circuit breaker, which can prevent the damage of the partition caused by the rise of internal pressure, and can use the partition The plate isolates the circuit breaker side including the fixed contacts, the movable contacts, and the interrupter from the load side including the switching mechanism and the overcurrent tripping device.

In order to achieve the above object, the present invention proposes the following technical solutions.

(1) A circuit breaker, characterized in that it comprises:

Fixed contacts provided with fixed contacts;

a movable contact provided with a movable contact capable of opening and closing with said fixed contact;

a support frame that rotatably supports the movable contact;

an arc extinguishing chamber for eliminating arcing between said fixed and movable contacts;

an opening and closing mechanism that drives the opening and closing of the movable contact;

a trip mechanism for tripping the latch of said opening and closing mechanism;

An overcurrent trip device that detects overcurrent and activates the trip mechanism;

a wire connected to the movable contact;

housing the fixed contact, the movable contact, the support frame and the housing of the arc extinguishing chamber;

a cover for accommodating the opening and closing mechanism and the tripping mechanism and mounted on the housing; and

having a conductive connection plate that isolates the circuit breaker side including the fixed contact, the movable contact, and the arc extinguishing chamber from the load side including the switching device and the overcurrent tripping device, And connect the wire with the overcurrent tripping device.

Therefore, in order to isolate the circuit breaker side including the fixed contact, the movable contact, and the arc extinguishing chamber from the load side including the switching device and the overcurrent tripping device, a conductive connecting plate can be used as a partition. Therefore, even when the space for arranging the separator is insufficient, the strength of the separator can be ensured, and damage to the separator due to an increase in internal pressure can be prevented. As a result, even when the high-temperature and high-pressure arc gas fills the circuit breaker side, it can prevent the high-temperature and high-pressure arc gas from entering the load side, preventing the load-side switching mechanism and overcurrent tripping device from being damaged, causing poor connection and tripping, Or prevent the occurrence of carbonization or adhesion of soot on the insulating container and internal molded parts on the load side, resulting in poor withstand voltage.

(2) In the circuit breaker described in (1),

The connecting plate is a metal connecting plate.

(3) In the circuit breaker described in (1) or (2),

The connecting plate is arranged so as to overlap the housing and the ends of the cover from the inside.

In this way, even when the pressure on the disconnecting portion side rises, the connection plate can be pressed against the case and the cover, and it is possible to prevent the connection plate from moving away or being displaced from the position of the connection plate. Therefore, even when an arc occurs on the circuit breaker side, the arc gas can be prevented from entering the load side, damage to the switching mechanism and the overcurrent tripping device can be suppressed, and connection failures and tripping failures can be reduced.

As described above, according to the present invention, a conductive connection plate, especially a metal connection plate, is used as the connection between the circuit breaker side including the fixed contact, the movable contact, and the arc extinguishing chamber, and the switching device and the overcurrent trip unit. The separator on the load side of the device is isolated, so even if the high-temperature and high-pressure arc gas fills the side of the circuit breaker, it can prevent the damage to the separator caused by the rise of internal pressure, and prevent the high-temperature and high-pressure arc gas from entering the load side.

Description of drawings

Fig. 1 is a longitudinal sectional view showing a schematic configuration of a circuit breaker according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view showing part of the connection plate 14 of the circuit breaker of FIG. 1 .

FIG. 3 is an enlarged top view of a part of the connection plate 14 of the circuit breaker of FIG. 1 viewed from the direction D2.

FIG. 4 is an enlarged longitudinal cross-sectional view showing part of the connection plate 14 of the circuit breaker in FIG. 1 as viewed from the direction D1.

Fig. 5 is an enlarged longitudinal sectional view showing part of a disconnecting portion of the circuit breaker in Fig. 1 .

Label description

1-shell, 2-middle cover, 3-fixed contact, 4-opening and closing mechanism, 5-movable contact, 6-interrupting chamber, 7-fixed contact, 8-movable contact, 9-support frame, 10-side wall, 11-grid, 12-protective plate, 13-conductor, 14-connection plate, 15-overcurrent tripping device, 16-load side terminal, 17-tripping rod, 18-top cover, 19-arc .

Detailed ways

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following embodiments, although various limitations are made on constituent elements, types, combinations, shapes, relative arrangements, etc., these are merely examples, and the present invention is not limited thereto.

Fig. 1 is a longitudinal sectional view showing a schematic configuration of a circuit breaker according to an embodiment of the present invention.

In FIG. 1 , the circuit breaker is provided with a fixed contact 3 , a movable contact 5 , and a support frame 9 for an insulator. The fixed contact 3 is fixed on the housing 1, the movable contact 5 is substantially linear, and can be opened and closed with the fixed contact 3, and the support frame 9 holds the movable contact 5 , so that it can rotate through the opening and closing shaft. Further, a movable contact 8 is provided at the front end of the movable contact 5, and a fixed contact 7 is provided at one end of the fixed contact 3, and a power supply side terminal is integrally formed at the other end of the fixed contact 3. The breaking part of the circuit breaker is constituted by the fixed contact 3 , the movable contact 5 and the supporting frame 9 . In addition, an arc extinguishing chamber 6 for extinguishing an arc generated by the switching operation between the fixed contact 3 and the movable contact 5 is provided in the disconnecting portion.

Here, the arc extinguishing chamber 6 is provided with a side wall 10 serving as an insulator support, and a plurality of grid pieces 11 made of magnetic materials are stacked and supported on the side wall 10 at predetermined intervals. Furthermore, the grid piece 11 is configured in a U-shape, and forms a notch through which the movable contact 5 can pass. In addition, an arc gas discharge port is provided in front of the circuit breaker, and the arc gas discharge port is closed by an insulator shield 12 for preventing entry of foreign matter, and the shield 12 is fixed by the shape of the support.

In addition, the circuit breaker is provided with an opening and closing mechanism 4 for opening and closing between the movable contact 5 and the fixed contact 3, and the opening and closing mechanism 4 can use the opening and closing shaft integrally formed with the support frame 9 as a fulcrum. Drive the movable contact 5 to open and close.

In addition, the circuit breaker is provided with a trip mechanism that releases the latch of the switching mechanism 4, and an overcurrent trip device 15 that detects an overcurrent and operates the trip mechanism. Here, a bimetal, a conductive heating element, an armature, and an electromagnet are incorporated in the overcurrent tripping device 15, and based on the detection result of the overcurrent flowing through the load-side terminal 16, a thermal or electromagnetic mechanical switch can be generated. sexual deflection. In addition, the trip mechanism can transmit the mechanical deflection generated in the overcurrent trip device 15 to the opening and closing mechanism 4 through the trip lever 17, so that the lock of the opening and closing mechanism 4 can be released.

A flexible lead wire 13 is connected to the rear end of the movable contactor 5 , and the lead wire 13 is connected to an overcurrent tripping device 15 through a metal L-shaped connection plate 14 . As a conductive material constituting the connection plate 14 , for example, a metal material, copper, stainless steel, or an aluminum alloy can be used, for example.

Here, the insulating container of the circuit breaker can be constituted by the case 1, the middle cover 2, and the top cover 18 made of molded resin. And, the circuit breaker and the arc extinguishing chamber 6 including the fixed contact 3, the movable contact 5, and the support frame 9 are accommodated in the casing 1, and the tripping mechanism and the switching mechanism 4 including the tripping lever 17 are accommodated in the middle cover. 2. The middle cover 2 can be installed on the shell 1 , and the top cover 18 can be installed on the middle cover 2 . In order to connect the toggle lever of the opening and closing device 4 to the support frame 9, a slit can also be set on the partition plate at the bottom of the middle cover 2.

The circuit breaker side including the fixed contact 3 , the movable contact 5 and the arc extinguishing chamber 6 is isolated from the load side including the switching mechanism 4 and the overcurrent tripping device 15 by a metal connecting plate 14 . Here, when the disconnecting part side and the load side are separated by the connecting plate 14, it is preferable to arrange the connecting plate 14 so as to overlap the ends of the case 1 and the inner cover 2 from inside.

In the structure shown in FIG. 1 , the disconnecting part of the central pole part is shown, but the interior of the insulating container can be divided by phase partitions, and the disconnecting parts of each phase can be accommodated in each divided space.

Moreover, when the fixed contact 3 and the movable contact 5 are closed, the current can pass through the power supply side terminal → the fixed contact 3 → the movable contact 5 → the wire 13 → the connecting plate 14 → the overcurrent tripping device 15 → the load side Terminal 16 path flow.

Moreover, once a large current such as a short-circuit current flows into the load-side terminal 16, the overcurrent tripping device 15 will operate, and the switching device 4 will be disconnected by the trip lever 17. Thereby, the movable contact 5 is detached from the fixed contact 3 .

When the movable contact 8 is separated from the fixed contact 7 , the current flowing into the load is cut off, and an arc occurs between the fixed contact 3 and the movable contact 5 . In addition, when an arc occurs, high-temperature and high-pressure arc gas containing metal particles and resin evaporated by the arc heat fills the inside of the interrupter.

Here, since the connection plate 14 is used to isolate the circuit breaker side including the fixed contact 3, the movable contact 5, and the arc extinguishing chamber 6 from the load side including the switching mechanism 4 and the overcurrent tripping device 15, even at high temperature When high-pressure arc gas fills the interrupter side, it is also possible to prevent high-temperature and high-pressure arc gas from entering the load side. In this way, it is possible to prevent the switch mechanism 4 and the overcurrent tripping device 15 on the load side from being damaged, causing poor connection or tripping, or preventing the insulating container and internal molded parts on the load side from being carbonized or soot adhered to causing poor withstand voltage. .

In addition, by using the metal connecting plate 14 as the separator, even when the space for arranging the separator is insufficient, the strength of the separator can be ensured, and the rupture of the separator due to an increase in internal pressure on the disconnecting portion side can be prevented.

Fig. 2 is an enlarged longitudinal sectional view showing part of the connection plate 14 of the circuit breaker of Fig. 1, Fig. 3 is a top view of a part of the connection plate 14 of the circuit breaker of Fig. 1, viewed from the direction D2, and Fig. 4 is an enlarged view It shows a longitudinal cross-sectional view of part of the connection plate 14 of the circuit breaker in FIG. 1 as viewed from the direction D1.

In FIGS. 2-4 , the connecting plate 14 is configured to overlap the ends of the case 1 and the middle cover 2 from the inside (parts A and B of FIG. 2 , part C of FIG. 3 ). In this way, even when the pressure on the disconnecting portion side rises, the connecting plate 14 can be pressed against the case 1 and the middle cover 2 to prevent the connecting plate 14 from being disengaged or the position of the connecting plate 14 being shifted. Therefore, even if an arc occurs on the circuit breaker side, the arc gas can be prevented from entering the load side, damage to the switching mechanism 4 and the overcurrent tripping device 15 can be suppressed, and poor connection and tripping can be reduced.

Fig. 5 is an enlarged longitudinal sectional view showing part of a disconnecting portion of the circuit breaker in Fig. 1 .

In FIG. 5 , if the movable contact 8 is separated from the fixed contact 7 , an arc 19 occurs between the fixed contact 3 and the movable contact 5 . And, when an arc 19 occurs, the arc 19 is cut off by the grid piece 11 to extinguish the arc.

In addition, when the arc 19 occurs, the high temperature and high pressure arc gas containing metal particles and resin evaporated by the arc heat fills the inside of the interrupter and flows toward the load side. If the arc gas flows to the load side, it is blocked by the connecting plate 14 and turns to the direction of the arc extinguishing chamber 6 .

Thereby, the flow rate of the arc gas entering the arc extinguishing chamber 6 can be increased, and the arc 19 generated between the fixed contact 3 and the movable contact 5 can quickly move to the arc extinguishing chamber, thereby promoting arc extinguishing of the arc 19 .

The embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the above-described embodiments. Various changes can be made within the scope of the technical thought of the present invention, and they all belong to the protection scope of the present invention.

For example, in the above-mentioned embodiments, a metal plate is exemplified as the connection plate, but the present invention is not limited thereto, and other conductive materials may also be used.

Claims (2)

1. A circuit breaker, characterized in that, comprising: Fixed contacts provided with fixed contacts; A movable contact with a movable contact that can realize opening and closing with the fixed contact; a supporting frame that rotatably supports the movable contact; an arc extinguishing chamber for eliminating arcs generated between said fixed and movable contacts; an opening and closing mechanism that drives the opening and closing of the movable contact; a tripping mechanism for releasing the lock of the opening and closing mechanism; An overcurrent trip device that detects overcurrent and activates the trip mechanism; a wire connected to the movable contact; housing the fixed contact, the movable contact, the support frame and the housing of the arc extinguishing chamber; a cover for accommodating the opening and closing mechanism and the tripping mechanism and mounted on the housing; and a metal connection plate that isolates the side of the circuit breaker including the fixed contact, the movable contact, and the arc extinguishing chamber from the load side including the switching device and the overcurrent tripping device, and Connect the wire to the overcurrent trip device. 2. The circuit breaker of claim 1, wherein: The connecting plate is configured to overlap end portions of the housing and the cover from the inner side of the housing.

Images