KR101573605B1 - Trip device of circuit breaker - Google Patents

Abstract

A trip device of a circuit breaker capable of adjusting a trip gap according to an embodiment of the present invention includes a bimetal, a guide cap provided in the bimetal and having a hole, a hollow guide rod connected to the hole of the guide cap, And a torsionally adjustable trip shaft having a tapered cross section at a region facing the adjustment bar, the adjustment groove being spaced apart from the adjustment bar and partially projecting therefrom, the adjustment bar being spaced apart from the adjustment bar.

Description

TRIP DEVICE OF CIRCUIT BREAKER [0002]

The present invention relates to a trip device of a circuit breaker, and more particularly, to a trip device of a circuit breaker capable of adjusting a trip gap capable of setting a gap between a bimetal and an adjustment trip shaft when a fault current is detected and a circuit is shut off .

A circuit breaker is a device that opens or closes a load in a transmission, substation or electrical circuit, or disconnects the current when an accident such as a ground or short circuit occurs. The circuit breaker switches the electrical line to the open or closed state by the user's operation.

This circuit breaker protects the load device and the line by shutting off the circuit when an overload or short circuit occurs in the line.

Among them, the circuit breaker mainly used has a one-time trip characteristic and an instantaneous trip characteristic. The short-time tripping characteristic refers to the overcurrent tripping characteristic having an operating time inversely proportional to the overcurrent value.

At this time, the stop-and-go characteristic is a thermal coin type using a thermal element such as bi-metal and a full-electron type using an ODP (oil dash pot) braking action.

The instantaneous trip characteristic trips the circuit breaker quickly due to a relatively large overcurrent such as a short circuit current. The tripping characteristic is that when an overcurrent exceeding the rated current flows, the circuit trips the circuit breaker before the temperature reaches a dangerous state by joule heat.

In this case, it is desirable that the circuit breaker operates quickly in terms of protection. However, in the converter, a transient overcurrent such as the starting current of the motor flows in addition to the normal load current.

Therefore, it is preferable to operate with a time delay within a range where the temperature of the converter does not exceed the allowable temperature so that the circuit breaker is not operated by such an overcurrent. In that sense, it is also called the demonstration operation characteristic.

Determination of the time delay in the demonstration operation characteristic corresponds to the time from when the bimetal begins to bend due to the overcurrent flow to when the opening / closing mechanism is actuated by the rotation of the adjustment trip shaft.

This delay time is determined by the initial setting gap of the bimetal and the adjustment trip shaft, the time from when the bimetal comes into contact with the adjustment trip shaft to the time when the adjustment trip shaft starts rotating, Is determined as an important factor.

A prior art related to the present invention is Korean Patent Laid-Open Publication No. 10-2005-0050999 (published on Jun. 1, 2005), which discloses a technology related to a voltage trip device of a circuit breaker.

The present invention provides a tripping device for a circuit breaker capable of adjusting a trip gap capable of setting an interval between a bimetal and an adjustment trip shaft when an accident current is detected and a circuit is shut off.

The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by those skilled in the art from the following description.

A trip device of a circuit breaker capable of adjusting a trip gap according to an embodiment of the present invention includes: a bimetal; A guide cap provided in the bimetal and having a hole; A hollow guide rod connected to the hole of the guide cap; An adjusting bar connected through the hollow of the guide rod and partially protruding therefrom; And an adjustable trip shaft spaced apart from the adjustment bar and capable of contacting the adjustment bar by operation of the bimetal and having a sloped cross section at a region facing the adjustment bar.

The trimming trip shaft includes a recessed contact provided at intervals spaced along the length direction and a protruding contact provided between the recessed contacts.

An inclined surface is provided between the depressed contact point and the protruding contact point.

When the adjustment trip shaft is pressed by the adjustment bar, it is rotated to separate the movable contact of the circuit breaker from the fixed contact.

The adjustment bar is disposed at a predetermined interval from the adjustment trip shaft, and is then joined to the guide rod by an applied current.

The adjustment bar is movable on the guide rod before being joined to the guide rod.

The guide cap is integrally or detachably connected to the upper portion of the bimetal. The guide cap may be made of a synthetic resin material.

According to the trip device of the circuit breaker capable of adjusting the trip gap according to an embodiment of the present invention, the gap (hereinafter referred to as a trip gap) between the bimetal and the adjustment trip shaft can be automatically adjusted and fixed without manual operation.

Thereby improving work productivity and reducing costs.

In addition, the trip gap can be adjusted and fixed to reduce the possibility of an error, thereby improving the quality of the circuit breaker.

In addition, it is possible to provide a plurality of trip gaps through the provisionally adjusted trip shaft having tapered cross-sectional shape contacts.

1 is a perspective view schematically showing a circuit breaker;
2 is a sectional view taken along the line A-A 'shown in Fig.
3 is a perspective view schematically showing a trip device of a circuit breaker installed in a circuit breaker according to an embodiment of the present invention.
4 is a perspective view schematically showing a tripping trip shaft of a trip circuit breaker according to an embodiment of the present invention.
FIG. 5 to FIG. 6 are schematic views showing an operation relationship between configurations of a trip device of a circuit breaker according to an embodiment of the present invention; FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: It is intended that the invention be described in its entirety by reference to the appended claims and their equivalents.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, a trip device of a circuit breaker capable of adjusting a trip gap according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a perspective view schematically showing a circuit breaker;

Referring to FIG. 1, the circuit breaker 10 functions to protect the load and the facility from a fault current which is several tens to several hundreds of times larger than the rated current such as an overcurrent or a short-circuit current due to a circuit failure.

At this time, the fault current is largely divided into an overload current and a short-circuit current. When each current flows above a reference value, the circuit breaker 10 opens the line.

In particular, the amount of current when short-circuit current flows flows from as few as several hundred amperes to as many as tens of thousands of amperes depending on the facility capacity, and the circuit breaker 10 is operated at this moment to open (block) the circuit.

In the operation mechanism due to the short circuit current of the circuit breaker 10, the demonstration operation characteristic is that heat is generated in the heater when an overcurrent flows in the circuit breaker.

The generated heat is transferred to the bimetal, and the bimetal is bent due to the difference in thermal conductivity between the two members constituting the bimetal, thereby pressing the adjusting trip shaft, thereby rotating the adjusting trip shaft.

Accordingly, the opening and closing mechanism is operated to switch the electric line to the open state to shut off the circuit.

Determination of the time delay in the demonstration operation characteristic corresponds to the time from when the bimetal begins to bend due to the overcurrent flowing to when the switching mechanism is actuated by the rotation of the adjustment trip shaft.

This delay time is the initial set gap of the bimetal and the adjustable trip shaft, the amount of ineffective curvature from when the bimetal comes into contact with the adjustable trip shaft to when the bimetal's curved load begins to rotate the adjustable trip shaft The rotation distance of the adjustment trip shaft from the rotation of the adjustment trip shaft to the start of operation of the opening / closing mechanism is determined as an important factor.

Thereby forming a bending amount which is the degree of rotation of the bimetal. Among the above factors, since the amount of invalid curvature and the rotation distance of the trip shaft are influenced by the characteristics of the individual circuit breaker, fine adjustment is difficult unless the component is replaced.

Therefore, in the demonstration operation characteristic, a factor that can adjust the necessary delay time is the gap between the bimetal and the adjustment trip shaft.

If the interval is too small, the tripping time of the circuit breaker 10 is shortened and tripped too fast, so that the circuit can be shut off even with a transient overcurrent such as a starting current.

On the other hand, if the interval is too large, the trip time of the circuit breaker 10 may not be delayed or tripped, and an overcurrent may be supplied to the circuit, thereby causing damage to the circuit.

Accordingly, the circuit breaker 10 calculates the amount of heat generated by the heater when the overcurrent flows and the amount of curvature of the bimetal, and develops it into several parts. For the accurate demonstration operation characteristic, the interval between the bimetal and the adjustment trip shaft .

2 is a cross-sectional view taken along the line A-A 'shown in Fig.

2, the circuit breaker 10 includes a case 20, a trip device 100, an opening / closing mechanism 200, a terminal portion 300, and an arc soffit portion 600.

The case 20 is made of an insulating outer structure for housing the components of the circuit breaker 10. The case 20 is molded with an insulating material to insulate the inside from the outside. This structure is general and will not be described in detail.

The trip device 100 of the circuit breaker according to the embodiment of the present invention has a function of detecting an abnormal current and an accident current such as an overcurrent and shutting off the circuit.

The trip device 100 of the circuit breaker according to an embodiment of the present invention includes a bimetal 110, a guide cap 120, a guide rod 130, an adjustment bar 140, and a trip adjustment shaft 150 .

Hereinafter, a trip device 100 of a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The opening / closing mechanism 200 has a function of mechanically turning the converter on and off, and includes a handle 210 and a lever 220.

The handle 210 provides a manual operation means capable of opening and closing the circuit by a pushing or pulling operation.

The lever 220 is connected to the handle 210 and serves as a means for providing a rotation support (not shown) of the handle 210. The lever 220 may be a U-shaped bent metal plate.

The lever 220 may be connected to the handle 210 in such a manner that the upper flat flat portion is fitted to the lower portion of the handle 210, or the like.

The terminal portion 300 includes a fixed contact 310 to which a power source and a load are connected, and a movable contact 320.

In other words, the terminal unit 300 includes a fixed contact 310 connected to the input side power source and fixed to the case 20, and a movable contact 320 connected to the load side and capable of separating or contacting the fixed contact 210 .

The stationary contactor 310 is configured to shut down the fault current of the line, and has a function of transmitting the power supplied from the converter to the load side.

The movable contact 320 is rotatably mounted in the case 20 and is mechanically connected to the opening / closing mechanism 200.

That is, the movable contactor 320 is manually operated by the lever 220 or operated by the opening / closing mechanism 200 triggered by the trip device 100.

The movable contactor 320 is disposed in contact with the fixed contactor 310 so as to be energized. The movable contactor 320 is disposed at a position where it can be contacted or separated from the stationary contactor 310 and is rotatable.

On the other hand, when protecting the circuit by tripping the circuit by disconnecting the movable contactor 320 from the fixed contact 310 in the event of a fault current, insulation in the air is destroyed by the current between the contacts, State arc is generated.

In addition, arc may cause arc to occur due to melting of insulation around the arc by the arc.

At this time, the arc extinguishing unit 400 has a function of dividing and cooling the generated arc, and discharging the arc pressure to the outside.

The arc extinguishing unit 400 can improve the breaking performance of the circuit breaker 10 by isolating the moving path where the stationary contactor 310 and the movable contactor 320 of the terminal unit 300 are in contact with or separated from each other.

FIG. 3 is a perspective view schematically showing a trip device of a circuit breaker installed in a circuit breaker according to an embodiment of the present invention, and FIG. 4 is a perspective view schematically showing a trip device of a trip device.

3 and 4, a trip device 100 of a circuit breaker according to an embodiment of the present invention includes a bimetal 110, a guide cap 120, a guide rod 130, a control bar 140, And an adjustable trip shaft (150).

The bimetal 110 is a bar-shaped member made of two sheets of thin metal plates having different coefficients of thermal expansion. The bimetal 110 can control the temperature of the device by using the bending property when the heat is applied.

When heat is transferred from the heater 160 that generates an appropriate amount of heat when an overcurrent is generated, the bimetal 110 is curved to one side (in the direction of the adjustment trip shaft).

The guide cap 120 may be integrally or detachably connected to the upper portion of the bimetal 110. The guide cap 120 is made of a lightweight synthetic resin material.

The guide rod 130 is connected to the guide cap 120 and has a hollow shape.

The adjustment bar 140 is connected to the guide rod 130 and has a part protruding. The adjustment bar 140 may be made of the same material as the guide bar 130.

The adjustment trip shaft 150 is disposed at a distance apart from the adjustment bar 140. [ The adjustment trip shaft 150 is capable of contacting the adjustment bar 140 by bending the bimetal 110.

When the adjustment trip shaft 150 is contact-pressed by the adjustment bar 140, the adjustment trip shaft 150 is rotated to separate the movable contact of the circuit breaker from the fixed contact.

At this time, the misalignment trip shaft 150 has a sloped cross section at a portion facing the adjustment bar 140.

The adjustment trip shaft 150 has a recessed contact 151, a protruding contact 152 and a slanted surface 153. Here, the recessed contact 151 and the protruding contact 152 refer to a contact with which the adjustment bar 140 is contacted.

The recessed contact points 151 are provided at intervals spaced along the body length direction of the temporary adjustment trip shaft 150.

A protruding contact 152 is provided between the depressed contact points 151.

At this time, an inclined surface 153 is provided between the depressed contact point 151 and the protruding contact point 152. The inclined surface 153 has a predetermined angle a and can be determined according to the distance t between the depressed contact point 151 and the protruding contact point 152.

5 to 6 are schematic views illustrating an operation relationship between the configurations of a trip device of a circuit breaker according to an embodiment of the present invention.

5 to 6, a trip device 100 of a circuit breaker according to an embodiment of the present invention includes a bimetal 110, a guide cap 120, a guide rod 130, a control bar 140, An adjustable trip shaft 150, and a heater 160. As shown in FIG.

When heat is transferred from the heater 160 that generates an appropriate amount of heat when an overcurrent is generated, the bimetal 110 is curved at one side (in the direction of the adjustment trip shaft).

The guide cap 120 is provided in the bimetal 110 and has a predetermined hole 121 penetrated therethrough. The guide cap 120 may be integrally or detachably connected to the upper portion of the bimetal 110.

The guide cap 120 is made of a lightweight synthetic resin material.

The guide rod 130 is connected to the hole 121 of the guide cap 120 and has a hollow shape. The guide bar 130 includes a hollow portion 131 to be wrapped around the hole 121 of the guide cap 120 and a step portion 132 extending from both ends of the hollow portion 131.

Here, the step portion 132 is formed to surround a part of both ends of the hole 121 of the guide cap 120.

The adjustment bar 140 is connected to the guide rod 130 and has a part protruding. The adjustment bar 140 may be made of the same material as the guide bar 130. At this time, the adjusting bar 140 may be provided with a latching jaw 141 at an end thereof.

The adjustment trip shaft 150 is disposed at a distance apart from the adjustment bar 140. [ The adjustment trip shaft 150 is capable of contacting the adjustment bar 140 by bending the bimetal 110.

When the adjustment trip shaft (150) is pressed by the adjustment bar (140), it is rotated to separate the movable contact of the circuit breaker from the fixed contact.

Here, the adjustment bar 140 is disposed at a preset distance D from the adjustment trip shaft 150, and then is connected to the guide rod 130 by an applied current.

The predetermined interval D can prevent the circuit from being damaged even if the circuit is not blocked by the overcurrent through the conditions such as the tripping condition of the adjustment bar 140 and the adjustment trip shaft 150, Means the minimum reference interval.

Thus, the predetermined interval D may be different for each circuit breaker, and such a difference need not be limited to the present invention.

If the distance between the adjustment bar 140 and the adjustment trip shaft 150 is smaller than the preset distance D, the trip time of the circuit breaker is shortened and the circuit is tripped too quickly to prevent the circuit from being over- .

On the other hand, if the interval is larger than the preset interval D, the trip time of the circuit breaker is not delayed or tripped, and an overcurrent is supplied to the circuit, which may cause damage to the circuit.

Meanwhile, the adjusting bar 140 can freely move on the guide rod 130 before being joined to the guide rod 130.

That is, when the adjustment bar 140 is disposed at a predetermined distance D from the adjustment trip shaft 150, the adjustment bar 140 is fixed on the guide rod 130 by the applied current.

As described above, the trip device of the circuit breaker capable of adjusting the trip gap according to an embodiment of the present invention can automatically adjust the gap (hereinafter referred to as a trip gap) between the bimetal and the adjustment trip shaft .

Thereby improving work productivity and reducing costs.

In addition, the trip gap can be adjusted and fixed to reduce the possibility of an error, thereby improving the quality of the circuit breaker.

In addition, it is possible to provide a plurality of trip gaps through the provisionally adjusted trip shaft having tapered cross-sectional shape contacts.

The trip device of the circuit breaker capable of adjusting the trip gap according to an embodiment of the present invention has been described above.

It is to be understood that the terminology or words used in the foregoing detailed description and in the following claims should not be construed as limited to ordinary or dictionary meanings and the inventor shall not be construed to limit the concept of the term to the best of his / Should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be properly defined.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory only and are not restrictive of the invention, It should be understood that water and variations may be present.

10: Circuit breaker
20: Case
100: Circuit breaker trip device
110: Bimetal
120: guide cap 121: hole
130: guide rod 131: hollow part
132:
140: adjusting bar 141: latching jaw
150: Adjustable trip shaft 151: Thrust contact
152: protruding contact 153: inclined surface
160: Heater
200: opening / closing mechanism 210: handle
220: Lever
300: terminal portion 310: fixed contact
320: Operational contact
400: arc soho

Claims (8)

Bimetal;
A guide cap connected to an upper portion of the bimetal;
A hollow guide rod connected to the hole of the guide cap;
An adjusting bar connected through the hollow of the guide rod and partially protruding therefrom; And
And an adjustable trip shaft spaced apart from the adjustment bar and capable of contacting the adjustment bar by operation of the bimetal, the adjustment trip shaft having a sloped cross section at an area facing the adjustment bar,
Wherein the adjustment bar is formed to be movable on the guide rod,
Wherein the adjustment bar is disposed at a predetermined interval from the adjustment trip shaft, and then the adjustment bar is joined to the guide bar by applying a current.
The method according to claim 1,
The variable-speed trip shaft includes:
A recessed contact provided at intervals spaced along the longitudinal direction,
And a protruding contact provided between the depressed contacts, wherein the protruding contact is provided between the depressed contacts.
3. The method of claim 2,
And a sloped surface is provided between the depressed contact point and the protruding contact point.
The method according to claim 1,
The variable-speed trip shaft includes:
And when the contact bar is pressed by the adjustment bar, the movable contact of the circuit breaker is rotated and separated from the stationary contactor.
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