EP2800122A1

EP2800122A1 - Instant adjusting device for molded case circuit breaker

Info

Publication number: EP2800122A1
Application number: EP12862436.8A
Authority: EP
Inventors: Se Yong Kim; Young Min Jun
Original assignee: Hyundai Heavy Industries Co Ltd
Current assignee: HD Hyundai Heavy Industries Co Ltd
Priority date: 2011-12-28
Filing date: 2012-12-23
Publication date: 2014-11-05
Anticipated expiration: 2032-12-23
Also published as: KR101206540B1; RU2573642C1; EP2800122B1; WO2013100504A1; EP2800122A4

Abstract

A circuit breaker of this application includes a fixable contact, a movable contact, a switchgear unit, a handle, a trip unit and an arc chamber unit, the circuit breaker being connected with a main circuit to cause a current to flow and the trip unit includes a fixed magnet being fixed on the main circuit, the fixed magnet configured to generate an electromagnetic force when the main circuit generates an abnormal current; an armature configured to be in contact with the fixed magnet in a rotation, one side thereof being spaced apart from the fixed magnet with a fixed interval and another side thereof forming a stepped slope; and an instant bar being in contact with the stepped slope of the armature, the instant bar performing a left and right rectilinear motion for adjusting the interval between the fixed magnet and the armature to rotate the armature. Therefore, this application has an effect where with an armature having a stepped slope with an inclination angle and an instant bar performing a left and right rectilinear motion to rotate the armature, an interval between a fixed magnet and an armature is adjusted and an abnormal current value triggering a trip is set.

Description

[Technical Field]

This application relates to an instant adjusting device for molded circuit breaker and more particularly to an instant adjustable trip device of a circuit breaker that may use an instant bar of trip unit to accurately adjust an interval between a fixed magnet and an armature and to increase a stability of the circuit breaker.

[Background Art]

Generally, a circuit breaker is an electrical safety device which automatically blocks a circuit to protect a circuit and load when an abnormal current (e.g., an overcurrent, an instantaneous current or a short current) flows between a power source and a load.
A trip for the instantaneous current of abnormal currents detects a situation where a current of a constant magnification of a rated current is instantaneously applied to the circuit breaker to trip the circuit breaker in a proper time so as not to damage the circuit or load for a corresponding magnification. This function may be referred to as an instantaneous trip function.
Korean Patent Publication No. 10-2006-0101035 discloses an instant adjustable trip device of a circuit breaker.
FIG. 1 is a vertical cross sectional diagram illustrating a conventional instant adjustable trip device of a circuit breaker.
Referring to FIG. 1, the conventional instant adjustable trip device of a circuit breaker 100 includes a magnet 110 being fixed on a main circuit to generate an electromagnetic force when an abnormal current is generated, an armature 120 rotating by the electromagnetic force of the magnet 110, a cross bar 130 linking with an operation of an armature 120 to rotate, a shutter 140 linking with an operation of the cross bar 130 to trigger a mechanism operation and perform a circuit blocking operation, an instant spring 150 adding a load toward an opposite rotation direction of the armature 130 to limit an operation range for a current, an instant bar 160 controlling the load of the instant spring 150 to adjust an operating current value and an instant dial 170 designating a position of the instant bar 160 by a user.
By these components, an electromagnetic force being generated between the magnet 110 and the armature 120 in the abnormal current is inversely proportional to the load being added by the armature spring 150. Therefore, in order that a trip may be generated in a higher current, the user rotates the instant dial 170 to incline to a bottom side of a inclination angle and the instant dial 170 is in contact with the instant bar 160 to guide an initial load increase of the instant spring 150.
According to the above described procedure, when an abnormal current value triggering the trip is set and the abnormal current is generated on a line, the electromagnetic force is generated by the magnet 110, the armature 120 is pulled by a gravitational force generated by the electromagnetic force of the magnet 110 and is rotated in an anticlockwise direction thereby the armature 120 is in contact with the magnet 110. At this time, because the armature 120 is supported by the instant spring 150, the electromagnetic force may be larger than an elastic force of the instant spring 150.
Because the conventional instant adjustable trip device of the circuit breaker 100 uses the elastic force of the instant spring 150, it is difficult to maintain a consistency of the load value due to a deviation (±10%) inherent in the instant spring not to constantly adjust the interval between the magnet and the armature.

[Technical Problem]

To solve the above described problem, this application proposes to provide an instant adjustable trip device of the circuit breaker that may use an instant bar to constantly adjust an interval between a magnet and an armature.

[Technical Solution]

In some embodiments, a circuit breaker includes a fixable contact, a movable contact, a switchgear unit, a handle, a trip unit and an arc chamber unit, the circuit breaker being connected with a main circuit to cause a current to flow and the trip unit includes a fixed magnet being fixed on the main circuit and generating an electromagnetic force when the main circuit generates an abnormal current, an armature being in contact with the fixed magnet in a rotation where one side thereof is spaced apart from the fixed magnet with a fixed interval and another side thereof forms a stepped slope and an instant bar being in contact with the stepped slope of the armature and performing a left and right rectilinear motion for adjusting the interval between the fixed magnet and the armature to rotate the armature.
In one embodiment, the circuit breaker may further include an armature supporter supporting one side of the armature and an armature spring connecting the armature and the armature supporter to provide an elasticity for the rotation of the armature according to a movement of the instant bar.
In one embodiment, the instant dial may further include an instant dial forming thereon a groove being embodied for an instantaneous current value.

[Technical Effects]

According to an embodiment of the invention, this application has an effect where with an armature having a stepped slope with an inclination angle and an instant bar performing a left and right rectilinear motion to rotate the armature, an interval between a fixed magnet and an armature is adjusted and an abnormal current value triggering a trip is set.
Also, this application has an effect where the instant dial may form thereon a groove being embodied through an instantaneous current value to accurately set an abnormal current value triggering a trip.

[Description of Drawings]

FIG. 1 is a vertical cross sectional diagram illustrating a conventional instant adjustable trip device of a circuit breaker.
FIG. 2 is a cross sectional diagram illustrating a general circuit breaker.
FIG. 3 is a perspective diagram illustrating a trip unit structure of a circuit breaker according to an example embodiment of the described technology.
FIG. 4 is a side elevation diagram illustrating a trip unit operation of a circuit breaker in FIG. 3.
FIG. 5 is a perspective diagram illustrating a trip unit operation of a circuit breaker in FIG. 3.
FIG. 6 is a diagram illustrating a combination status of a plurality of trip units in FIG. 3.

[Mode for Invention]

The embodiments and the configurations depicted in the drawings are illustrative purposes only and do not represent all technical scopes of the invention, so it should be understood that various equivalents and modifications may exist at the time of filing this application. Although a preferred embodiment of the disclosure has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
Terms and words used in the specification and the claims shall be interpreted as to be relevant to the technical scope of the invention based on the fact that the inventor may property define the concept of the terms to explain the invention in best ways.
The terms "first" and "second" can be used to refer to various components, but the components may not be limited to the above terms. The terms will be used to discriminate one component from the other component. For instance, the first component may be referred to the second component and vice versa without departing from the right of the disclosure.
The term "and/or" should be understood as including all of combination that can be made from one or more relevant items. For example, the term "the first item, the second item, and/or the third item" means not only the first, the second, or the third item, but the combination of all of items that can be made from two or more of the first, second, or third items.
When a component is referred to as being "connected to" or "linked to" another component, the component may be directly connected to or linked to another component or an intervening component may be present therebetween. In contrast, if a component is referred to as being "directly connected to" or "directly linked to" another component, an intervening component may not be present therebetween.
The terms used in the specification are for the purpose of explaining specific embodiments and have no intention to limit the disclosure. Unless the context indicates otherwise, the singular expression may include the plural expression. In the following description, the term "include" or "has" will be used to refer to the feature, the number, the step, the operation, the component, the part or the combination thereof without excluding the presence or addition of one or more features, the numbers, the steps, the operations, the components, the parts or the combinations thereof.
Identification letters (e.g., a, b, c, etc.) in respective steps are used for the sake of explanation and do not described order of respective steps. The respective steps may be changed from a mentioned order unless specifically mentioned in context. Namely, respective steps may be performed in the same order as described, may be substantially simultaneously performed, or may be performed in reverse order.
Unless defined otherwise, the terms including technical and scientific terms used in this specification may have the meaning that can be commonly apprehended by those skilled in the art. The terms, such as the terms defined in the commonly-used dictionary, must be interpreted based on the context of the related technology and must not be interpreted ideally or excessively.
FIG. 2 is a cross sectional diagram illustrating a general circuit breaker.
Referring to FIG. 2, a circuit breaker includes a fixable contact 210 being connected with a power source and a load, a moveable contact 220 being connected or disconnected with the fixable contact 210 through a rotation, a switchgear unit 230 adjusting a movement of the moveable contact 220 to switch a circuit, a trip unit 240 detecting an abnormal current (i.e., an overcurrent or an instantaneous current and a short current) if occurs to trigger an operation of the switchgear unit 230 and to block the circuit and an arc chamber unit 250 removing an arc being generated when the circuit is blocked.
FIG. 3 is a perspective diagram illustrating a trip unit structure of a circuit breaker according to an example embodiment of the described technology.
Referring to FIG. 3, the trip unit 240 of the circuit breaker includes a fixed magnet 310 generating an electromagnetic force when an abnormal current is generated in the main circuit, an armature 320 forming a stepped slope 321 and being in contact with the fixed magnet 310 in a rotation and an instant bar 330 rotating the armature.
In one embodiment, the trip unit 240 of the circuit breaker may further include an armature supporter 340 and an armature spring 350 connecting the armature 320 and the armature supporter 340 to provide an elasticity for a rotation of the armature 320. In one embodiment, the instant bar 330 may further include an instant dial 360 forming thereon a groove being embodied for an instantaneous current value.
The fixed magnet 310 is fixed on the main circuit. The fixed magnet 310 generates an electromagnetic force when an abnormal current is generated in the main circuit.
One side of the armature 320 is spaced apart from the fixed magnet with a fixed interval and the armature 320 is rotatably installed. The armature 320 is in contact with the fixed magnet 310 when the armature 320 is rotated. Another side of the armature 320 forms a stepped slope 321. In one embodiment, the armature 320 may further include a coupling projection 322 capable of fixing the instant spring 350.
When the instant bar 330 performs a left and right rectilinear motion, one side thereof is in contact with the stepped slope 321 of the armature 320 thereby the instant bar 330 rotates the armature 320 according to a height difference in the stepped slope 321 to adjust an interval between the fixed magnet 310 and the armature 320. In one embodiment, the instant bar 330 is in contact with the stepped slope 321 of a plurality of armatures 320 to adjust the interval between each of the plurality of the armatures 320 and each of the plurality of the fixed magnets 310.
The armature supporter 340 supports one side of the armature and fixes one side of the armature spring 350.
The armature spring 350 connects the armature 320 and the armature supporter 340 to provide an elasticity for a rotation of the armature 320 according to a movement of the instant bar 330.
The instant dial 360 is connected with the instant bar 330 and causes the instant bar 330 to perform a left and right rectilinear motion when the instant dial 360 is rotated. In one embodiment, the instant dial 360 may form thereon a groove 361 being embodied for an instantaneous current value. Therefore, the instant dial 360 links a driver to easily rotate.
FIG. 4 is a side elevation diagram illustrating a trip unit operation of a circuit breaker in FIG. 3 and FIG. 5 is a perspective diagram illustrating a trip unit operation of a circuit breaker in FIG. 3.
Referring to FIG. 4 and FIG.5, when the instant dial 360 is rotated, the instant bar 330 performs a left and right rectilinear motion and one side of the instant bar 330 is in contact with the stepped slope 321 of the armature 320 thereby the instant bar 330 rotates the armature 320 according to a height difference in the stepped slope 321 to adjust the interval between the fixed magnet 310 and the armature 320. That is, an abnormal current value triggering a trip is set.
When an abnormal current is generated, an electromagnetic force being generated from the fixed magnet 310 is inversely proportional to the interval between the fixed magnet 310 and the armature 320. Therefore, in order that a trip is triggered at a higher current than a pre-set current, the instant dial 60 may be rotated to connect a high side 321 b of the stepped slope 321 of the armature 320 and one side of the instant bar 330.
When a high side 321 b of the stepped slope 321 of the armature 320 is in contact with one side of the instant bar 330, the armature 320 rotates toward the fixed magnet 310 and the interval between the fixed mange 310 and the armature 320 becomes narrower. Therefore, the armature spring 350 is more stretched and an elastic force is larger.
In the other hands, in order that a trip is triggered at a lower current than a pre-set current, the instant dial 60 is rotated to connect a lower side 321 a of the stepped slope 321 of the armature 320 and one side of the instant bar 330.
When a lower side 321 a of the stepped slope 321 of the armature 320 is in contact with one side of the instant bar 330, the armature 320 rotates toward an opposite direction of the fixed magnet 310 and the interval between the fixed mange 310 and the armature 320 becomes wider. Therefore, the armature spring 350 is more shrunk and an elastic force is smaller.
When the abnormal current value triggering the trip is set by the above described procedure and the abnormal current is generated on the main circuit, the electromagnetic force is generated by the fixed magnet 310 and the a gravitational force is applied to the armature 320 by the electromagnetic force of the fixed magnet 310.
The armature 320 is supported by the armature spring 350 and when the gravitational force being applied to the armature 320 by the electromagnetic force of the fixed magnet 310 is larger than the elastic force of the armature spring 350, the armature 320 is rotated to be in contact with the fixed magnet 310.
FIG. 6 is a diagram illustrating a plurality of trip units connected with a cross bar and a shutter in FIG. 3.
Referring to FIG. 6, one side of the armature 320 is connected with a cross bar 610 and another side of the cross bar 610 is connected with a shutter 620.
In one embodiment, when the armature 320 of the trip unit 240 is rotated to be in contact with the fixed magnet 310, the armature 320 may apply pressure to a lower side of the cross bar 610. In one embodiment, the cross bar 610 restricts the shutter 620 and the shutter 620 is connected with the switchgear unit and when the cross bar 610 is rotated, the shutter 620 restricted by the cross bar 610 is removed from a rotation by the cross bar 610 and the switchgear unit 240 is tripped.
Therefore, when the armature is rotated to be in contact with the fixed magnet 310, the armature 320 applies pressure to the lower side of the cross bar 610 to rotate the cross bar 610 toward a clockwise direction and when the cross bar 610 is rotated toward a clockwise direction, a constriction state of the shutter 620 constrained by the cross bar 610 is removed to cause the switchgear unit to trip.
According to the described technology, this application has an effect where with the armature having the stepped slope with an inclination angle and the instant bar performing a left and right rectilinear motion to rotate the armature, the interval between the fixed magnet and the armature may be adjusted and the abnormal current value triggering a trip may be set.
Also, this application has an effect where the instant dial may form thereon a groove being embodied through an instantaneous current value to accurately set the abnormal current value triggering a trip.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure.

Claims

In a circuit breaker including a fixable contact, a movable contact, a switchgear unit, a trip unit and an arc chamber unit, the circuit breaker being connected with a main circuit to cause a current to flow, the trip unit comprising:
a fixed magnet being fixed on the main circuit, the fixed magnet configured to generate an electromagnetic force when the main circuit generates an abnormal current;

an armature configured to be in contact with the fixed magnet in a rotation, one side thereof being spaced apart from the fixed magnet with a fixed interval and another side thereof forming a stepped slope; and

an instant bar being in contact with the stepped slope of the armature, the instant bar performing a left and right rectilinear motion for adjusting the interval between the fixed magnet and the armature to rotate the armature.
The circuit breaker of claim 1, further comprising:
an armature supporter configured to support one side of the armature; and

an armature spring connecting the armature and the armature supporter to provide an elasticity for the rotation of the armature according to a movement of the instant bar.
The circuit breaker of claim 1, wherein the instant bar further includes an instant dial forming thereon a groove being embodied for an instantaneous current value.