CN111566772A

CN111566772A - Circuit breaker

Info

Publication number: CN111566772A
Application number: CN201880083983.6A
Authority: CN
Inventors: 禹相贤; 朴珍映; 咸承珍
Original assignee: LS Electric Co Ltd
Current assignee: LS Electric Co Ltd
Priority date: 2018-02-06
Filing date: 2018-11-19
Publication date: 2020-08-21
Anticipated expiration: 2038-11-19
Also published as: KR20190095025A; KR102017804B1; CN111566772B; WO2019156319A1

Abstract

The present invention relates to a circuit breaker, and more particularly, to an opening and closing mechanism assembly of a circuit breaker. The circuit breaker of an embodiment of the present invention includes: a housing having a side plate insertion portion formed at a portion thereof; a side plate having a coupling portion formed at a portion thereof, the side plate being inserted into the side plate insertion portion and being disposed at the side plate insertion portion; a trip bar rotatably coupled to the coupling portion; and a return spring for providing an elastic force to return the trip bar to a home position, wherein the coupling portion is formed as a coupling groove, a coupling shaft protruding to both sides is formed at a lower portion of the trip bar, and the coupling shaft is inserted into and coupled with the coupling groove.

Description

Circuit breaker

Technical Field

The present invention relates to a circuit breaker, and more particularly, to an opening and closing mechanism assembly of a circuit breaker.

Background

Generally, a circuit breaker is an electrical device that is installed in a power transmission line, a power transformation line, or a part of a circuit, and that protects an electrical facility and a load by opening the circuit when a fault such as a short circuit occurs or switching on and off the load. Among them, a small circuit breaker (circuit breaker for small wiring) is installed in a small distribution board forming a low-voltage circuit (15 to 30A) of 110/220V ac for overcurrent protection and short-circuit protection, and is installed in a distribution board as a switch for a house, a market, an office, a market, or the like, and is used as a device capable of conveniently switching on and off a plurality of loads at one place. In addition, the present invention is also used for turning on and off a power supply of a machine such as a machine tool or a factory equipment.

As in the case of an industrial general circuit breaker, a small-sized circuit breaker includes a contact portion including a fixed contact and a movable contact, an on-off mechanism portion capable of opening and closing the contact portion, a detection mechanism portion for detecting an abnormal current, a trip portion for protecting a line or a load by separating the on-off mechanism portion when an abnormal current such as an overcurrent or a short-circuit current occurs, and an arc extinguishing portion for performing a function of extinguishing and cooling an arc generated at the time of opening.

Fig. 1 shows a prior art miniature circuit breaker. For the explanation of the internal structure, the state where the cover is omitted is shown. The figure shows a housing 1 which is insulated from the outside and used for fixing and supporting the position of each component, a terminal part 2 connected with a power supply or a load, and an on-off mechanism part comprising a handle 3; a contact portion including the fixed contact 4 and the movable contact 5, and a trip portion including the armature 7, the magnet 15, the bimetal 16, the trip bar 10, and the like.

Fig. 2 shows a switching mechanism assembly of a related art small circuit breaker.

The on-off mechanism assembly includes: a handle 3 rotatably coupled to an upper portion of the side plate 6; a trip bar 11 rotatably coupled to one side of the side plate 6; a trip bar pin 12 serving as a shaft of the trip bar 11; a trip bar spring 13 providing a reset force to the trip bar 11; a U-shaped pin 9 which is engaged with the lower portion of the handle 3 and actuates a lever 10; and a lever 10 connected to the U-shaped pin 9, which moves the crossbar 8 and is restrained at one end by the trip bar 11.

In the conventional small circuit breaker, an operation of breaking an overcurrent is as follows. When an overcurrent flows on the circuit, the current flowing in the bimetal 16 coupled to the movable contact 3 also sharply increases, and heat is generated. This increase in current increases the magnetic flux density of the magnet 15 and the armature 7, thereby generating electromagnetic force. The armature 7 is pulled in the direction in which the magnet 15 is located, and the lever 10 restricted by the trip bar 11 is released, whereby the crossbar 8 is reset to separate the movable contact 5 from the fixed contact 4, thereby opening the circuit.

On the other hand, the bimetal 16 is also deformed by heat generated in the bimetal 16. The bimetal 16 pushes the trip bar 11 when bent, and releases the lever 10 restricted by the trip bar 11. Therefore, the movable contact 5 is separated from the fixed contact 4 when the crossbar 8 is reset, and the circuit is opened.

Fig. 3 is an exploded perspective view illustrating the trip bar combined with the side plate in fig. 2.

The trip bar 11 is rotatably coupled to a lower portion of the side plate 6. At this time, the trip bar 11 is coupled with the side plate 6 by the trip bar pin 12. A trip bar spring 13 is provided at the trip bar pin 12 to reset the trip bar 11 to the home position.

However, when assembling the related art miniature circuit breaker, the trip bar pin 12 needs to be inserted through a hole (not labeled) formed in the side plate 6, the hole 11a of the trip bar 11, and the hole 13a of the trip bar spring 13. As described above, since it is necessary to hold four kinds of members during the operation, it is difficult for the operator to perform the operation. In addition, the trip bar spring is formed of a single torsion spring combined with a portion of the trip bar, and thus, the acting force is weak, so that it is difficult to continuously maintain the performance.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a circuit breaker in which an assembling property of a trip mechanism is improved. In addition, a circuit breaker that stably maintains the performance of a trip mechanism is provided.

Technical scheme for solving problems

The circuit breaker of an embodiment of the present invention includes: a housing having a side plate insertion portion formed at a portion thereof; a side plate having a coupling portion formed at a portion thereof, the side plate being inserted into the side plate insertion portion and being disposed at the side plate insertion portion; a trip bar rotatably coupled to the coupling portion; and a return spring for providing an elastic force to return the trip bar to a home position, wherein the coupling portion is formed as a coupling groove, a coupling shaft protruding to both sides is formed at a lower portion of the trip bar, and the coupling shaft is inserted into and coupled with the coupling groove.

Here, a shielding part may be protrusively formed at the side plate insertion part, the shielding part shielding and supporting the coupling part.

In addition, the entrance of the combining portion may be narrower than the central portion.

In addition, a support part protruding forward and downward and supporting a rotational movement of the trip bar may be formed at an upper portion of the coupling part, and a front surface of the support part may be formed as a vertical surface.

In addition, the shielding portion may be formed with an entrance surface formed obliquely to allow the support portion to easily enter and a contact surface contacting the support portion.

In addition, a spring receiving portion formed as a groove and capable of supporting the return spring may be formed at the trip bar.

In addition, spring support portions formed to protrude may be provided at upper and lower portions of the spring seating portion, respectively, so that the return spring is difficult to be detached.

In addition, a leg portion may be provided at a middle portion of a lower portion of the trip bar, the coupling shaft may be formed at the leg portion, and a guide portion supporting and guiding the return spring may be provided at a back surface or a front surface of the leg portion.

Further, the return spring may be constituted by a double torsion spring.

Effects of the invention

According to the circuit breaker of the embodiment of the invention, the trip bar is directly combined with the side plate through the insertion combination, so that the assembly performance is improved.

In addition, because the tripping bar and the tripping bar pin are formed into a whole, the action is common, and the stability is improved.

In addition, because the trip bar pin is omitted, the number of parts is reduced, the operation is easy, the production procedures are reduced, and the production efficiency is improved.

In addition, a double torsion spring is applied to a spring for returning the trip bar, whereby the returning force is excellent, durability is increased, and thus a service life is increased.

Drawings

Fig. 1 is an internal perspective view of a related art small circuit breaker.

FIG. 2 is a perspective view of the on-off mechanism assembly of FIG. 1.

Fig. 3 is an exploded perspective view of the trip bar of fig. 2.

Fig. 4 is an internal perspective view of a circuit breaker according to an embodiment of the present invention.

Fig. 5 is a perspective view of the housing of fig. 4.

FIG. 6 is a perspective view of the on/off mechanism assembly of FIG. 4.

Fig. 7 is an exploded perspective view of fig. 6.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to illustrate the present invention in detail so that those skilled in the art can easily carry out the present invention, but it is not intended to limit the technical spirit and scope of the present invention thereto.

Fig. 4 is an internal perspective view of a circuit breaker according to an embodiment of the present invention, fig. 5 is a perspective view of a case of fig. 4, fig. 6 is a perspective view of an opening and closing mechanism assembly of fig. 4, and fig. 7 is an exploded perspective view of fig. 6. A small-sized circuit breaker according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The circuit breaker of an embodiment of the present invention is a trip mechanism of a small circuit breaker, including: a side plate 20 having a coupling portion 25 formed at a portion thereof; a trip bar 30 rotatably coupled to the coupling portion 25; and a return spring 40 for providing an elastic force to return the trip bar 30 to a home position, wherein the coupling portion 25 is formed as a coupling groove, a coupling shaft 36 protruding to both sides is formed at a lower portion of the trip bar 30, and the coupling shaft 36 is inserted into and coupled with the coupling groove.

The case constituting the external appearance of the circuit breaker according to an embodiment of the present invention may be in the shape of a box, and may be composed of a case 60 whose top surface is opened, and a cover (not shown) whose bottom surface is opened and coupled to an upper portion of the case 60.

The housing 60 is provided with components such as a contact portion 66, an on-off mechanism portion 67, a trip portion 68, and a terminal portion 69.

The housing 60 is provided with a side plate insertion portion 61 into which the side plate 20 of the opening/closing mechanism portion 67 can be inserted.

A shaft groove 62 is formed in an inner wall of the side plate insertion portion 61, and the shaft groove 62 provides a space into which the coupling shaft 36 of the trip bar 30 can be inserted and operated. The shaft groove 62 may be formed long in the up-down direction.

A shielding portion 63 is formed to protrude inside the side plate insertion portion 61, and the shielding portion 63 shields and supports the coupling portion 25 of the side plate 20. The shielding portion 63 may be formed adjacent to the shaft groove 62. An entrance surface 63a and a contact surface 63b are formed in the shielding portion 63, the entrance surface 63a is formed as an inclined surface to facilitate insertion of the support portion 26 formed to protrude from the side plate 20, and the contact surface 63b is in contact with the support portion 26 of the side plate 20.

The side plate 20 includes a pair of side faces 21 and a lower face 22. The handle 50 of the opening/closing mechanism 67 is rotatably provided at the upper end of the side plate 20. The handle shaft 51 is inserted into the handle shaft hole 23 as a rotation shaft of the handle 50.

The lever 5 for actuating the cross bar 52 is connected to the handle 50 by a link pin 54 formed in a U-shape.

The side plate 20 is formed with a pin operation groove (or a pin operation hole) 24 that can operate the link pin 54.

The side plate 20 is formed with a coupling portion 25 into which the trip bar 30 can be inserted and coupled. Here, the coupling portion 25 may be formed as a coupling groove. The entrance to the junction 25 is preferably narrower than the central portion. Thus, the coupling shaft 36 is less likely to fall off when inserted into the coupling portion 25.

A support portion 26 is formed to protrude from the upper portion of the coupling portion 25. The support portion 26 protrudes forward (load side) and downward. The support portion 26 supports the trip bar 30 to make it difficult for the trip bar 30 to be separated from the coupling portion 25, and supports the rotational movement of the trip bar 30.

The front surface of the support portion 26 may be formed as a vertical surface. The front surface (the left side is set to the rear and the right side is set to the front in the drawing) of the support portion 26 can be in contact with the contact surface 63b of the side plate insertion portion 61.

The trip bar 30 is provided to restrict the lever 53 in a normal state and to release the restriction of the lever 53 to cause a trip operation when a fault current occurs. The trip bar 30 can be rotated by the bimetal 55 or the shaft lever 56, and thus the lever 53 is released from the restriction. The trip bar 30 is biased rearward by a return spring 40. When the bimetal 55 is bent by a fault current or the shaft lever 56 is rotated in conjunction with the rotation of the armature 57, the trip bar 30 is pushed forward, and the trip bar 30 releases the restriction of the lever 53 to generate a trip operation, thereby opening the circuit.

The trip bar 30 is formed substantially in a "Y" shape. An adjusting member 31 for adjusting the interval between the trip bar 30 and the bimetal 55 is coupled to the upper end of the trip bar 30.

The trip bar 30 is provided with a spring receiving portion 32 capable of supporting the return spring 40. The spring placing portion 32 is preferably formed as a groove.

Spring support portions

33, 34 are provided at upper and lower portions of the spring placing portion 32, respectively, so that the return spring 40 is difficult to be easily detached. The

spring support portions

33, 34 may be formed to protrude.

A leg portion 35 is provided at a lower portion of the trip bar 30. A single leg portion 35 may be formed at a middle portion of a lower portion of the trip bar 30.

Coupling shafts 36 are protrusively formed along both sides of the leg portions 35. The coupling shaft 36 is inserted and coupled to the coupling portion 25. The coupling shaft 36 is a rotation shaft of the trip bar 30.

A guide portion 37 is provided on the back or front surface of the leg portion 35. The guide portion 37 may be formed to have the same width as that of the leg portion 35 and to protrude with a prescribed thickness. The guide portion 37 may be formed in an arc or ring shape. The guide portion 37 supports the return spring 40 to prevent the return spring 40 from being inclined to one side, and functions to guide the movement of the return spring 40.

A return spring 40 is provided. The return spring 40 applies a force to rotate the trip bar 30 in the backward direction by providing an elastic force to the trip bar 30. The return spring 40 applies force by inserting its middle portion 41 into the spring seating portion 32 of the trip bar 30.

The return spring 40 may be constructed of a double torsion spring. That is, the coil portions 42 wound on both sides of the middle portion 41 are formed, and the coupling shaft 36 is inserted into the coil portions 42 and supported by the guide portion 37.

The trip unit operates to interrupt an overcurrent as follows.

When an overcurrent or a fault current flows in the circuit, the current flowing through the bimetal 55 coupled to the movable contact of the contact portion 66 is increased and heat is generated.

When the current in the bimetal 55 increases, the magnetic flux density of the magnet 68 and the armature 57 increases, and the electromagnetic force is generated. When the current in the bimetal 55 sharply increases, the armature 57 is pulled in a direction in which the magnet 68 is located by the generated electromagnetic force. When the armature 57 moves in the direction of the magnet 68, the shaft lever 56 engaged with the armature 57 rotates, and the trip bar 30 is pushed forward. Thereby, the restriction of the lever 53 restricted to the trip bar 30 is released, and the movable contact of the contact portion 66 is separated from the fixed contact when the crossbar 52 is reset, and the circuit is opened.

The disconnection may also be performed by heat generated in the bimetal 55. The bimetal 55, which is a thermally deformable material, is bent due to heat generated by an overcurrent flowing through the circuit. The bimetal 55 pushes the trip bar 30 when it is bent, thereby releasing the lever 53 from being restrained by the trip bar 30. Thus, when the crossbar 52 is reset, the movable contact is separated from the fixed contact, and the circuit is opened.

According to the miniature circuit breaker of the embodiment of the invention, since the trip bar is directly combined with the side plate through the insertion combination, the assembling property is improved.

In addition, because the trip bar and the trip bar pin are formed into a whole, the action is common and the stability is improved.

In addition, a double torsion spring is applied to a spring for returning the trip bar, whereby the returning force is excellent, durability is increased, and thus the lifespan is increased.

The embodiments described above are embodiments for realizing the present invention, and various modifications and variations can be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments of the present invention are disclosed for illustrating the technical idea of the present invention, and are not intended to limit the scope of the technical idea of the present invention. That is, the scope of the present invention is defined by the claims, and all technical ideas within the scope equivalent to the scope of the claims are included in the scope of the present invention.

Claims

1. A circuit breaker, comprising:

a housing having a side plate insertion portion formed at a portion thereof;

a side plate having a coupling portion formed at a portion thereof, the side plate being inserted into the side plate insertion portion and being disposed at the side plate insertion portion;

a trip bar rotatably coupled to the coupling portion; and

a return spring providing an elastic force to return the trip bar to a home position,

the coupling portion is formed as a coupling groove,

and a coupling shaft protruding to both sides is formed at the lower part of the trip bar, and the coupling shaft is inserted into and coupled with the coupling groove.

2. The circuit breaker of claim 1,

and a shielding part for shielding and supporting the combining part is formed at the side plate inserting part in a protruding way.

3. The circuit breaker of claim 1,

the inlet is narrower in the junction than in the central portion.

4. The circuit breaker of claim 2,

and a support part which protrudes forward and downward and supports the rotation motion of the trip bar is formed at the upper part of the combining part, and the front surface of the support part is formed into a vertical surface.

5. The circuit breaker of claim 4,

an entrance surface and a contact surface are formed in the shielding portion, the entrance surface is formed to be inclined so that the support portion can easily enter, and the contact surface is in contact with the support portion.

6. The circuit breaker of claim 1,

a spring placing portion formed as a groove to support the return spring is formed at the trip bar.

7. The circuit breaker of claim 6,

spring support portions are formed to protrude at upper and lower portions of the spring seating portion, respectively, so that the return spring is hard to be detached.

8. The circuit breaker of claim 1,

a leg portion is provided at a middle portion of a lower portion of the trip bar, the coupling shaft is formed at the leg portion, and a guide portion that supports and guides the return spring is provided at a back surface or a front surface of the leg portion.

9. The circuit breaker of claim 1,

the reset spring is composed of a double torsion spring.