KR20170052367A

KR20170052367A - Instantaneous Trip Device of Circuit Breaker

Info

Publication number: KR20170052367A
Application number: KR1020150154731A
Authority: KR
Inventors: 함승진
Original assignee: 엘에스산전 주식회사
Priority date: 2015-11-04
Filing date: 2015-11-04
Publication date: 2017-05-12

Abstract

The present invention relates to an instantaneous trip device of a small circuit breaker, and more specifically, to an instantaneous trip device of a small circuit breaker which can block instantaneous currents in a small circuit breaker. The instantaneous trip device of a small circuit breaker, according to one embodiment of the present invention, contains a fixing contact connecting one terminal portion thereof, a movable contact which conducts or blocks a circuit as contacting or separated from the fixing contact, and an opening device portion which moves the movable contact. The instantaneous trip device comprises: an instantaneous lever which is coupled with a handle shaft of the opening/closing device to rotate along with a handle, and has a protrusion unit on one side thereof; an armature which is coupled with a lower part of the instantaneous lever; a bimetal which is coupled with the movable contact and can be curved when overcurrent flows in the circuit; a magnet which is coupled with an upper part of the bimetal; and a trip bar which restricts or releases operations of the opening/closing device and can be rotated by the protrusion unit.

Description

[0001] The present invention relates to an instantaneous trip device of a circuit breaker,

[0001] The present invention relates to an instantaneous trip device for a small circuit breaker, and more particularly, to an instantaneous trip device for a small circuit breaker which can interrupt an instantaneous current in a small circuit breaker.

In general, the small circuit breaker is installed in a small panel board which forms low voltage circuit (15 ~ 30A) of AC 110 / 220V and is used for overcurrent protection and short circuit protection. It is built in the distribution panel by switches such as shopping center, office, department store, It is used as a device that conveniently opens and closes a large number of loads. It is also used to open and close the power of equipment such as machine tools and factory facilities.

This small circuit breaker maintains the On position when a normal current flows in the circuit, and when the abnormal current such as an overcurrent flows in the circuit, the trip device operates to place the circuit breaker in the Off position, From the track to protect the track and the load facility.

Typical fault current ranges from over 130% of rated current to overcurrent or fault current of more than 10 times rated current and short-circuit current. In the overcurrent region, a method of tripping a breaker with a time characteristic is mainly used by using a bimetal element, and an instantaneous current of about 10 times the rated current uses an electronic trip unit in the case of a short circuit current. In the case of an electronic trip unit, a mechanism utilizing a principle of electromagnetism that generates a magnetic force by using a magnetic field generated by a current is widely used.

However, in the case of a small-capacity circuit breaker with a short-circuit capacity of less than 5 kA, some circuit-breakers do not use an electronic trip unit. In this case, the bimetal can be applied from the overcurrent region to the short-circuit current region only depending on the characteristics of the bimetal. However, in recent years, there has been a tendency that load commutation lush current is increased due to complication of electrical system, increase in load with switching characteristics, and increase in capacitive inductive load. In this case, There is a need to quickly isolate the load.

In particular, a low-capacity circuit breaker with a short-circuit capacity of less than 2.5 kA should operate quickly even at the above-mentioned instantaneous current. However, since the miniature circuit breaker according to the related art has a bimetallic structure, instantaneous current can not be cut off promptly.

Fig. 1 shows a partial perspective view of a small-sized shortage according to the prior art, and Fig. 2 shows a partial perspective view in the other direction.

The handle 1 is axially coupled to a side plate 11 and is capable of rotating. A U-pin (10) is assembled to the handle (1), and a lever (9) is axially coupled to the other end of the U-pin (10).

When the handle 1 is inserted, the U-pin 10 rotates and descends due to its rotation. At this time, one end of the lever 9 presses the upper end of the cross bar 7, The other end of the trip bar 12 is caught by the latching portion of the trip bar 12. When the handle 1 is continuously rotated, the lever 9 is pivoted about the other end, and one end of the lever 9 continues to push the upper end of the cross bar 7, so that the cross bar 7 moves downward. At the same time, the movable contact 4, which is hooked on the cross bar 7, is simultaneously rotated downward, so that the movable contact 5 and the fixed contact 6 contact each other and a current flows.

If a fault current such as an overcurrent occurs, the bimetal 3 is bent and the gap screw 13 coupled to the trip bar 12 is pushed. At this time, the trip bar 12 is rotated clockwise, The restraint of the lever 9 which extends over the latching portion of the trip bar 12 is released. At this time, the crossbar 7 which the lever 9 has been pressing in the face contact is lifted up by the compression spring at the lower side. At the same time, the movable contact 4 pressed by the cross bar 7 is lifted at the same time, so that the fixed contact 6 and the movable contact 5 are separated from each other and the current is cut off.

FIG. 3 is a side view showing a state in which a transient current flows in a short-circuiting short-circuit according to the prior art.

When a current flows in the bimetal 3, a heat corresponding to the amount of current is generated in the bimetal 3, and at this time, the bimetal 3 is bent in the direction in which the gap screw 13 is present by the expansion coefficient corresponding to the metal coefficient of the bimetal 3 When the end of the bimetal 3 pushes the gap screw 13, the breaker trips.

In general, the tripping device using the bimetal operation requires a bending time of the bimetal, so that it takes a blocking time of several tens of ms. That is, a circuit breaker having a trip device using only a bimetal is disadvantageous in that it cuts off the overcurrent and the instantaneous / short circuit current only depending on the bimetal, so that it can not be blocked promptly when an accident current of 8 to 10 times the rated current flows. Generally, to prevent the spread of accidents, it should normally be shut off within 10ms.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a small-trip short-term instant trip device which includes a trip device using a principle of an electromagnet in a small-sized circuit breaker, .

The instantaneous trip device of a small-short circuit according to an embodiment of the present invention includes a stationary contactor connected to one side terminal portion, a movable contact connected to the other side terminal portion and energized or shut off the circuit as the contact or separation of the stationary contactor, An instantaneous lever which is coupled to a handle shaft of the opening and closing mechanism and rotates together with the handle and has a protrusion formed on one side thereof; An armature coupled to a lower portion of said instantaneous lever; A bimetal coupled to the movable contact and capable of being bent when an overcurrent flows through the circuit; A magnet coupled to an upper portion of the bimetal; And a trip bar capable of restraining or releasing motion of the opening and closing member and being rotatable by the protrusion.

The instant lever may be formed in a three-stage structure having an inverted triangle shape. The instant lever may have an insertion port coupled to the handle shaft at a first end thereof, the protrusion is provided at a second end of the upper lever, And a mounting portion to which the armature can be coupled is provided in the third stage.

Further, the insertion port is formed in a circular tube shape.

Further, the protrusion is formed as a bar parallel to the handle shaft.

Further, the mounting portion is formed as a flat plate.

In addition, the trip bar is characterized in that a latching portion capable of engaging with the protruding portion is formed to protrude from the trip bar.

In addition, the latching portion may include an inclined portion protruding rearward and a contact portion extending from the inclined portion and capable of contacting the protruding portion.

Also, the amateur is formed in a 'C' shape in which the portion facing the bimetal is opened.

Further, the magnet is formed in a 'C' shape in which a portion facing the armature is opened.

According to the instantaneous trip device of the small-sized short-circuit according to the embodiment of the present invention, the instantaneous trip device using the principle of the electromagnet in the small-sized circuit breaker has the effect of rapidly breaking even in the instantaneous current region. To this end, a three-stage instantaneous lever is provided to operate the trip bar in the event of a fault current.

In addition, there is an effect that the magnet is directly attached to the bimetal and the armature is sandwiched between the levers, thereby improving the assemblability.

Also, since the instantaneous current is rapidly cut off, there is an effect of preventing damage to the contact portion and the breaker portion of the breaker.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial perspective view of a prior art miniature car short.
2 is a partial perspective view of another embodiment of a small truck shortage according to the prior art.
3 is a side view of a prior art miniature car short.
4 is a partial perspective view of a small vehicle shortage according to an embodiment of the present invention.
5 is a partial detail view of Fig.
6 is a perspective view of the instantaneous lever in Fig.
FIG. 7 is a cross-sectional view of a miniature truck according to an embodiment of the present invention, in which the magnet and the armature are in contact with each other.
FIG. 8 is another embodiment of the magnet and the armature in FIG.
9 is a side view of an off state in a short-circuiting vehicle according to an embodiment of the present invention.
10 is a side view of an on-state in a short-circuiting vehicle according to an embodiment of the present invention.
FIG. 11 is a side view of the armature in contact with the magnet due to the instantaneous current in the short-circuiting motor according to the embodiment of the present invention. FIG.
FIG. 12 is a side view of a state in which a trip operation is caused by an instantaneous current in a small-sized short circuit according to an embodiment of the present invention. FIG.
FIG. 13 is a side view of a small-sized short circuit according to an embodiment of the present invention in a state in which it is switched to an off state after a trip operation by an instantaneous current.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 a manner that allows a person skilled in the art to easily carry out the invention. And does not mean that the technical idea and scope of the invention are limited.

FIG. 4 is a partial perspective view of a small car shortage according to an embodiment of the present invention, and FIG. 5 is a partial detail view of FIG. 6 is a perspective view of the instantaneous lever in Fig. FIG. 7 is a side view of an off-state in a short-circuiting vehicle according to an embodiment of the present invention. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The instantaneous trip device for a small truck shortage according to an embodiment of the present invention includes a stationary contactor 21 connected to one side terminal portion 20 and a second side terminal portion 25 connected to the other side terminal portion 25, (30) for moving the movable contactor (26), characterized in that the handlebar shaft (31) of the opening and closing device part (30) is provided with a movable contactor An instant lever (40) coupled with the handle (32) and rotated at one side to form a protrusion (44); An armature (50) coupled to a lower portion of the instantaneous lever (40); A bimetal 55 coupled to the movable contact 26 and capable of being bent when an overcurrent flows through the circuit; A magnet 60 coupled to an upper portion of the bimetal 55; And a trip bar (65) for restraining or releasing movement of the switchgear section (30) and being rotatable by the protrusion section (44).

For the convenience of understanding, the basic operation of the switchgear 30 will be described first. The opening and closing device 30 is connected to the handle 32 by a handle 32 and a link 33 that can be operated to an on-off position according to a user's operation, A cross bar 36 which is in contact with one end of the lever 34 and receives a pressing force to vertically move; a side plate 35 on which the handle 32 and the lever 34 are rotatably installed; .

The circuit portion includes a fixed contact 21 coupled to one terminal portion 20 and a movable contact 21 coupled to the other terminal portion 25 and capable of being contacted with or separated from the fixed contactor 21 by a pressing force of the crossbar 36, (26).

The on-off operation of the breaker according to the operation of the handle 32 is as follows. When the handle 32 is placed in the ON position, one end of the lever 34, which is rotated and lowered by the handle 32, presses the crossbar 36. The crossbar 36 moves downward, (26) is brought into contact with the fixed contact (21). As a result, energization of the circuit occurs (see Fig. 10). [

When the handle 32 is in the off position, as one end of the lever 34 is lifted by the handle 32, the pressure that pressed the crossbar 36 disappears and the crossbar 36 moves up and down do. Thereby, the movable contact 26 is separated from the fixed contact 21. (See Fig. 9)

Next, the main configuration of the instantaneous trip device of a small-vehicle short-period according to an embodiment of the present invention will be described.

The instantaneous lever 40 is provided between the side plate 35 and the trip bar 65 while enclosing the handle 32. The instantaneous lever 40 can be formed symmetrically with respect to the longitudinal center plane (the center cross-section among the vertical longitudinal cross-sections of the small-vehicle short-term end, the same applies hereinafter).

The instantaneous lever 40 can be formed in a three-stage structure having an inverted triangular shape when viewed from the side view. That is, a first end and a second end may be formed at an upper portion, and a third end may be formed at a lower portion. And an insertion port 41 coupled to the handle shaft 31 is provided at a first end formed on one side of the upper portion. Here, the insertion port 41 may be formed in the shape of a pipe protruding perpendicularly to the longitudinal center plane. The handle shaft 31 is inserted into the insertion port 41.

The protruding portion 44 is provided at the second end formed on the other side of the upper portion of the instantaneous lever 40. The protrusion 44 may be provided as a rod parallel to the handle shaft 31. The protruding portion 44 can press the trip bar 65.

And a mounting portion 47 to which the armature 50 can be coupled is provided at a third end formed at the lower portion of the instantaneous lever 40. Here, the mounting portion 47 may be formed as a flat plate. The mounting portion 47 may be provided with a hook 48 to which the armature 50 can be fastened.

The insertion port 41 and the protrusion 44 and the mounting portion 47 may be formed as a single component when the instantaneous lever 40 is manufactured as a detailed component of the instantaneous lever 40. [ That is, the instantaneous lever 40 can be made of one injection-molded product.

The instantaneous lever 40 can be rotated clockwise or counterclockwise about the insertion port 41 as an axis.

The trip bar 65 fixes and supports the other end of the lever 34 so that one end of the lever 34 can press the crossbar 36 when the normal ON operation is performed, So that the cross bar 36 can be raised to the original position by the force of the return spring.

The trip bar (65) is provided with a latching portion (66) for allowing the protrusion (44) to contact rearward. The engaging portion 66 may be composed of an inclined portion 67 projecting upwardly upward and a contact portion 68 extending from the inclined portion 67 and capable of contacting the protruding portion 44 of the instantaneous lever 40 . At this time, the upper surface of the contact portion 68 may be formed to have a larger inclination angle than the upper surface of the inclined portion 67. The inclination angle of the upper surface of the contact portion 68 is formed in a direction orthogonal to the rotation direction of the protruding portion 44 so that the pressing force can be easily received. When the instantaneous lever 40 rotates clockwise, the trip bar 65 receives the force of the protrusion 44 and rotates in the clockwise direction, so that the other end of the lever 34 is released from the restraint.

A bimetal (55) is coupled to a portion of the movable contact (26). The bimetal 55 is rotated by heat generated when an overcurrent flows through the circuit, thereby pushing the trip bar 65 to block the circuit. More precisely, when the bimetal 55 is bent, the upper end of the bimetal 55 contacts the gap screw 70 provided in the wing portion of the trip bar 65 to push the trip bar 65. The bimetal 55 can be used as a conventional tripping device when an overcurrent flows through the circuit. The bimetal 55 can be used as an instantaneous trip device by magnetizing the magnet 60 and the armature 50, which will be described later, by the current flowing in the bimetal 55 when a fault current flows through the circuit.

The magnet 60 is coupled to the intermediate portion of the bimetal 55 and is magnetized when an electric current flows through the bimetal 55 to generate an electromagnetic force. The magnet 60 may be made of an iron core. The magnet 60 may be formed in a 'C' shape so as to surround the bimetal 55. Here, the open face of the magnet 60 can be coupled to the trip bar 65. The magnet 60 may be coupled to the bimetal 55 by screwing or welding.

The armature (50) is installed in the mounting portion (47) of the instantaneous lever (40). The armature 50 can be made of an iron core. The armature 50 is formed in a 'C' shape and can be coupled in a state of wrapping the mounting portion 47. Here, the open face of the armature 50 can be coupled to the bimetal 55. That is, the armature 50 can be installed in a position opposite to the magnet 60. As a result, a magnetic path connecting the magnet 60 and the armature 50 can be formed. The armature 50 can be fixed by the hook 48 of the mounting portion 47. [ Of course, the amateur 50 may be coupled to the bimetal 55 by screwing, welding, or the like.

7 is a cross-sectional view of the magnet 60 being magnetized and the armature 50 being in contact. The magnet 60 and the armature 50 form a single closed loop to maximize the magnetic force generated.

8 shows an example in which the magnet 61 and the armature 51 form one circular magnetic path in another embodiment. The magnetic force generated by this circular path can be maximized.

The operation of the instantaneous trip device of the small-vehicle short-period according to the embodiment of the present invention will be described. FIG. 9 is a side view of the off state, FIG. 10 is a side view of the on state, FIG. 11 is a side view of the state in which the armature is in contact with the magnet by the instantaneous current, Is a side view of a state in which the inverter is switched to the off state after the trip operation by the instantaneous current.

9, when the handle 32 is in the off state, the movable contactor 26 is disconnected from the fixed contact 21 and no current flows through the circuit.

As shown in FIG. 10, when the handle 32 is placed in the on state, that is, in the engaged state, the movable contact 26 comes into contact with the stationary contact 21 and current flows in the circuit. At this time, the instantaneous lever 40 is in the same position as the off state, and the protruding portion 44 is in a state of being in contact with the contact portion 68 of the trip bar 65 without applying any force. The magnet 60 coupled to the bimetal 55 and the armature 50 coupled to the mounting portion 47 of the instantaneous lever 40 are spaced apart from each other by a predetermined distance.

In the steady state, when a fault current which instantaneously reaches 10 times or more of the rated current flows in the circuit, a sudden current change occurs in the bimetal 55 and the magnet 60 is magnetized and attracts the armature 50. That is, the state shown in FIG. 11 is obtained.

Referring to FIG. 12, the armature 50 is in contact with the magnet 60 to rotate the instantaneous lever 40. The instantaneous lever 40 rotates in the clockwise direction about the handle shaft 31 and the protrusion 44 pushes the contact portion 68 of the trip bar 65 and the trip bar 65 rotates in the clockwise direction. As a result, the lever 34, which has been restrained by the lower portion of the trip bar 65, is released. The lever 34 is released and the crossbar 36 is moved upward by the restoring force of the return spring (not shown) and the force pressing the movable contact 26 is removed so that the movable contact 26 is moved to the fixed contact 21 ), And the current flowing through the circuit is cut off. Further, the force of the lever 34 is transmitted by the link 33, and the handle 32 is rotated to the Off position.

When the fault current disappears or the magnetic force of the magnet 60 disappears, the instantaneous lever 40 is returned to its original position by the torsion spring (not shown) provided on the trip bar 65 and is in a state as shown in FIG.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the scope of the present invention but to limit the scope of the technical idea of the present invention. That is, the scope of protection of the present invention should be construed according to the following claims, and all technical ideas which are within the scope of the same should be interpreted as being included in the scope of the present invention.

20, 25 terminal portion 21 fixed contact
26 Operational contact 30 Braking device
31 Handle shaft 32 Handle
33 Link 34 Lever
35 Sideboards 36 Crossbars
40 Instant lever 41 Insertion hole
44 protrusion 47 mounting part
50 amateur 55 bimetal
60 Magnet 65 Trip Bar
66 engaging portion 67 inclined portion
68 Contacts 70 Gap Screw

Claims

An instantaneous trip device of a small-sized short-circuit device including a fixed contact connected to one terminal portion, a movable contact connected to the other terminal portion and energized or cut off the circuit as the fixed contactor is contacted or disconnected, and an opening / closing device for moving the movable contact ,
An instantaneous lever coupled to a handle shaft of the switchgear portion and rotating together with the handle and having a protrusion formed on one side thereof;
An armature coupled to a lower portion of said instantaneous lever;
A bimetal coupled to the movable contact and capable of being bent when an overcurrent flows through the circuit;
A magnet coupled to an upper portion of the bimetal;
And a trip bar capable of restraining or releasing motion of the opening and closing member and being rotatable by the protrusion.

[2] The apparatus as claimed in claim 1, wherein the instant lever is formed in a three-stage structure having an inverted triangle shape, and has an insertion port coupled to the handle shaft at a first end of the upper portion, And an attachment portion capable of engaging with the armature is provided at a third end of the lower portion.

3. The instantaneous trip device of claim 2, wherein the insertion port is formed in a circular tube shape.

The instantaneous trip device of claim 1, wherein the protrusion is formed as a rod parallel to the handle shaft.

3. The instantaneous trip device of claim 2, wherein the mounting portion is formed of a flat plate.

The instantaneous trip device of claim 1, wherein the trip bar is formed with a latching portion protruding from the trip bar.

7. The instantaneous trip device of claim 6, wherein the latching portion comprises an inclined portion protruding rearward and a contact portion extending from the inclined portion and capable of contacting the protruding portion.

The instantaneous trip device of claim 1, wherein the armature is formed in a 'C' shape having an opening toward the bimetal.

The instantaneous trip device of claim 1, wherein the magnet is formed in a 'C' shape with an opening toward the armature.