Gap adjusting method in trip mechanism of molded case circuit breaker

Abstract

Disclosed is a gap adjusting method which easily adjusts a gap between a bimetal and a crossbar by using a gap adjusting block and an adjusting screw in a trip mechanism of a molded case circuit breaker without a separate additional device. The gap adjusting method in the trip mechanism of the molded case circuit breaker includes setting a reference gap between a crossbar and a bimetal, measuring a total resistance of the trip mechanism and a trip stroke of a switching mechanism to set a compensation gap, placing a gap adjusting block on a position separated from a crossbar by a gap based on the sum of the reference gap and the compensation gap, rotating an adjusting screw assembled with the bimetal to contact the adjusting screw with the gap adjusting block, and adhering the adjusting screw to the bimetal.

Claims

1. A gap adjusting method in a trip mechanism of a molded case circuit breaker, the gap adjusting method comprising: setting a reference gap between a crossbar and a bimetal; measuring a total resistance of the trip mechanism and a trip stroke of a switching mechanism to set a compensation gap; placing a gap adjusting block on a position separated from a crossbar by a gap based on a sum of the reference gap and the compensation gap; rotating an adjusting screw assembled with the bimetal to contact the adjusting screw with the gap adjusting block; and adhering the adjusting screw to the bimetal.

2. The gap adjusting method of claim 1, wherein a contact surface of the gap adjusting block is planarly formed.

3. The gap adjusting method of claim 1, wherein a contact surface of the gap adjusting block is vertical to a rotation axis of the adjusting screw.

4. The gap adjusting method of claim 1, wherein a front end of the adjusting screw is formed of a round surface of a planar surface.

5. The gap adjusting method of claim 2, wherein a rear end of the adjusting screw is formed of one of a straight-shaped groove, a cross-shaped groove, a straight-shaped projection, and a cross-shaped projection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the disclosure.

(2) In the drawings:

(3) FIG. 1 is a cross-sectional view of a related art molded case circuit breaker;

(4) FIG. 2A is a front view of a related art trip mechanism;

(5) FIG. 2B is a side view of the related art trip mechanism;

(6) FIG. 3 is a flowchart of a related art gap adjusting method;

(7) FIGS. 4A, 4B and 4C are process views of a related art gap adjusting operation;

(8) FIG. 5A is a partial front view of a trip mechanism according to an embodiment of the present invention;

(9) FIG. 5B is a partial side view of the trip mechanism according to an embodiment of the present invention;

(10) FIGS. 6A and 6B are front view and side view of a bimetal according to an embodiment of the present invention;

(11) FIGS. 7A and 7B are detailed views of an adjusting screw according to an embodiment of the present invention;

(12) FIG. 8 is a flowchart of a gap adjusting method according to an embodiment of the present invention; and

(13) FIG. 9 is a view of a gap adjusting operation according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE DISCLOSURE

(14) Description will now be given in detail of the exemplary embodiments, with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components will be provided with the same reference numbers, and description thereof will not be repeated.

(15) FIGS. 5A and 5B are partial front view and partial side view of a trip mechanism according to an embodiment of the present invention; FIGS. 6A and 6B are front view and side view of a bimetal according to an embodiment of the present invention; FIGS. 7A and 7B are detailed views of an adjusting screw according to an embodiment of the present invention; FIG. 8 is a flowchart of a gap adjusting method according to an embodiment of the present invention; and FIG. 9 is a view of a gap adjusting operation according to an embodiment of the present invention. Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

(16) A gap adjusting method in a trip mechanism of a molded case circuit breaker, according to an embodiment of the present invention, includes: setting a reference gap between a crossbar and a bimetal; measuring a total resistance of the trip mechanism and a trip stroke of a switching mechanism to set a compensation gap; placing a gap adjusting block on a position separated from a crossbar by a gap based on the sum of the reference gap and the compensation gap; rotating an adjusting screw assembled with the bimetal to contact the adjusting screw with the gap adjusting block; and adhering the adjusting screw to the bimetal.

(17) A hole 11 may be formed at an upper portion of the bimetal 10, and a tap process may be performed for the hole 11.

(18) An adjusting screw 20 may be coupled to the hole 11 of the bimetal 10. The adjusting screw 20 may rotate to move forward and backward, and a gap between the adjusting screw 10 and a crossbar 30 may be adjusted.

(19) When a fault current is applied to a circuit breaker, a heater 50 generates heat, and the heat is transferred to the bimetal 10 to bend the bimetal 10. At this time, the adjusting screw 20 assembled with the bimetal 10 pushes the crossbar 30 of a switching mechanism to move a nail (not shown), and binding of a latch is released by the nail, whereby a trip of the switching mechanism is performed.

(20) Here, an amount of applied current and a time are changed according to a gap between the crossbar 30 and the adjusting screw 20 coupled to the bimetal 10.

(21) A front end 21 of the adjusting screw 20 is a surface which contacts the crossbar 30. The front end 21 may be formed of a round surface of a planar surface so that a contact surface is not changed despite rotation.

(22) In a rear end 22 of the adjusting screw 20, a straight-shaped or cross-shaped surface may be engraved or embossed so as to enable an angle to be easily adjusted. That is, the rear end 22 of the adjusting screw 20 may be formed of one of a straight-shaped groove, a cross-shaped groove, a straight-shaped projection, and a cross-shaped projection.

(23) The gap between the crossbar 30 and the adjusting screw 20 coupled to the bimetal 10 may be determined based on the sum of a reference gap and a compensation gap.

(24) First, the reference gap between the crossbar 30 and the bimetal 10 may be set. The reference gap may be determined based on a rating for each product.

(25) The compensation gap may be determined by a trip stroke of the switching mechanism and a total resistance of the trip mechanism. Here, the trip stroke denotes a distance from a position of the crossbar 30 in a normal state to a position in which the crossbar 30 rotates and thus the switching mechanism is released. The total resistance of the trip mechanism is measured including the heater 50.

(26) By rotating the adjusting screw 20, the front end 21 of the adjusting screw 20 may be disposed at a position separated from the crossbar 30 by a setting gap. The gap is a gap determined based on the sum of the reference gap and the compensation gap. In this case, this gap may be set by a gap adjusting block 60.

(27) The gap adjusting block 60 may be freely moved in up, down, left, and right directions at a side of a product. The gap adjusting block 60 may be operated by a auxiliary device. The gap adjusting block 60 may be inserted between the crossbar 30 and the adjusting screw 20, and may be separated from the crossbar 30 by the determined gap. Also, the adjusting screw 20 may be automatically rotated to move to a contact surface 61 of the gap adjusting block 60, and thus, the gap can be optimized as a gap suitable for the each product.

(28) An initial position of the gap adjusting block 60 may start from a surface of the crossbar 30. The gap adjusting block 60 may move by the determined gap in a direction of the adjusting screw 20, and deviation, based on a bending amount of the bimetal 10, for each product is included in gap adjustment.

(29) A contact surface 61 of the gap adjusting block 60, which contacts the adjusting screw 20, may be planarly formed. Also, the front end 21 of the adjusting screw 20 may be planarly formed, and the front end 21 of the adjusting screw 20 and the contact surface 61 of the gap adjusting block 60 are not slid and thus do not cause an error of each product.

(30) Moreover, the contact surface 61 of the gap adjusting block 60 may be vertical to a rotation axis of the adjusting screw 20. Therefore, it is easy to adjust a gap between the contact surface 61 of the gap adjusting block 60 and the front end 21 of the adjusting screw 20 by moving the gap adjusting block 60.

(31) Moreover, the gap adjusting block 60 may have a thickness and stiffness which are not modified by an adhering force of the adjusting screw 20. The gap adjusting block 60 is movable in up, down, left, and right directions, and thus may simultaneously adjust a single phase or a plurality of phases of the circuit breaker.

(32) According to the gap adjusting method in the trip mechanism of the molded case circuit breaker, a gap may be set even in a state where a current is not applied (i.e., a trip state of the circuit breaker), and thus, equipment such as a current applying device, a laser welding device, and a cooling device are not needed. Accordingly, the cost for equipment is reduced, and the cost and a time for maintenance are reduced.

(33) Moreover, since a cooling process is not needed, a process is shortened in time, and scattering caused by cooling does not occur.

(34) According to the gap adjusting method in the trip mechanism of the molded case circuit breaker, assembly is easy, and a consistency of quality for each product is enhanced.

(35) The foregoing embodiments and advantages are merely exemplary and are not to be considered as limiting the present disclosure. The present teachings can be readily applied to other types of apparatuses. This description is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. The features, structures, methods, and other characteristics of the exemplary embodiments described herein may be combined in various ways to obtain additional and/or alternative exemplary embodiments.

(36) As the present features may be embodied in several forms without departing from the characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be considered broadly within its scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.