Actuator for circuit breaker and method for manufacturing the same

Abstract

The present disclosure may fix the second yoke without using an upper cover and a lower cover, thereby having an effect of simplifying the entire structure, and reducing the fabrication cost, and decreasing the fabrication time.

Claims

1. An actuator for a circuit breaker comprising: a frame; a coil provided at both inner sides of the frame; a permanent magnet disposed adjacent to the coil; a first yoke provided to surround the coil to form a main magnetic path; and a second yoke provided at a lower side of the first yoke to form an auxiliary magnetic path, wherein: fitting portions are provided at both ends of the second yoke; fitting holes are formed at both upper sides of the first yoke and configured to accommodate the fitting portions; engaging protrusions are formed at both upper sides of the fitting holes to secure the fitting portions to the fitting holes; and an upper surface of each of the engaging protrusions is formed to be inclined downward and in an inward direction toward the fitting hole.

2. An actuator for a circuit breaker, comprising: a coil; and a stationary core, a movable core configured to be brought into contact with or separated from the stationary core, and an operating rod configured to move the movable core provided within the coil, wherein: the stationary core is formed with a first elastic member accommodating portion and a first operating rod moving hole configured to accommodate the operating rod; the movable core is formed with a second elastic member accommodating portion and a second operating rod moving hole configured to move the operating rod; an elastic member is provided in the first elastic member accommodating portion and the second elastic member accommodating portion to provide an elastic force to the movable core.

3. The actuator for a circuit breaker according to claim 2, wherein: a width of the first elastic member accommodating portion is larger than a width of the first operating rod moving hole to form a first step between the first elastic member accommodating portion and the first operating rod moving hole; a width of the second elastic member accommodating portion is larger than a width of the second operating rod moving hole to form a second step between the second elastic member accommodating portion and the second operating rod moving hole; a movement adjuster disposed on an outer circumferential surface of the operating rod proximate to the second step; and the movement adjuster is configured to move the movable core in a direction away from the stationary core when an elastic force is provided to the operating rod by the elastic member provided within the first elastic member accommodating portion and the second elastic member accommodating portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

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

(2) In the drawings:

(3) FIG. 1 is an exploded perspective view illustrating an actuator for a circuit breaker in the related art;

(4) FIG. 2 is a cross-sectional view illustrating an actuator for a circuit breaker in the related art;

(5) FIG. 3 is a schematic view illustrating the path of a main magnetic field formed within an actuator for a circuit breaker in the related art;

(6) FIG. 4 is a schematic view illustrating the path of an auxiliary magnetic field formed within an actuator for a circuit breaker in the related art;

(7) FIG. 5 is a perspective view illustrating an actuator for a circuit breaker according to the present disclosure;

(8) FIG. 6 is a cross-sectional view illustrating an actuator for a circuit breaker according to the present disclosure;

(9) FIG. 7 is a schematic view illustrating a configuration in which an actuator for a circuit breaker according to the present disclosure is fixed to a fixing jig; and

(10) FIG. 8 is a flow chart illustrating a fabrication process of an actuator for a circuit breaker according to the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

(11) Hereinafter, an actuator for a circuit breaker according to an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

(12) FIG. 5 is a perspective view illustrating an actuator for a circuit breaker according to the present disclosure, and FIG. 6 is a cross-sectional view illustrating an actuator for a circuit breaker according to the present disclosure, and FIG. 7 is a schematic view illustrating a configuration in which an actuator for a circuit breaker according to the present disclosure is fixed to a fixing jig, and FIG. 8 is a flow chart illustrating a fabrication process of an actuator for a circuit breaker according to the present disclosure.

(13) As illustrated in FIGS. 5 and 6, the actuator 100 for a circuit breaker according to the present disclosure may include a frame 500, a coil 140 wound within the frame 140, a permanent magnet 200 disposed adjacent to the coil 140, a first yoke 110 formed to surround the coil 140 to form a main magnetic path, and a second yoke 120 located at a lower side of the first yoke 110 to form an auxiliary magnetic path, a stationary core 150 provided within the coil 140, a movable core 160 brought into contact with or separated from the stationary core 150, an operating rod 170 configured to move the movable core 160, a first magnetic force adjustment plate 190 and a second magnetic force adjustment plate 210 located between the first yoke 110 and the second yoke 120 to adjust a magnetic strength formed through the main magnetic path.

(14) The frame 500 may include each constituent element therewithin, and the coil 140 may be provided at both inner sides of the frame 500 to generate a magnetic flux when a current is applied thereto, thereby generating a magnetic force between the stationary core 150 and the movable core 160 to be brought into contact with each other.

(15) The permanent magnet 200 may enhance the generated magnetic flux to efficiently carry out contact between the stationary core 150 and the movable core 160.

(16) The first yoke 110 has a U-shape and forms a main magnetic path along with the stationary core 150 and the movable core 160.

(17) The second yoke is formed in a plate shape, and located at a lower side of the first yoke 110 to form an auxiliary magnetic path.

(18) Here, fitting holes 113 are formed at both upper sides of the first yoke 110, and fitting portions 121 are formed at both ends of the second yoke 120, and the fitting portions 121 are fitted into the fitting holes 113, thereby allowing the second yoke 120 to be connected to the first yoke 110.

(19) Furthermore, engaging protrusions 111 in which an upper surface 111a thereof is inclined downward as being positioned in an inward direction of the fitting holes 113 are formed at both upper sides of the fitting holes 113, and the fitting portions 121 are fitted into the fitting holes 113 in a state that a lower surface of the engaging protrusions 111 is brought into contact with an upper surface of the second yoke 120, and thus the second yoke 120 is more securely fixed to the first yoke 110 as well as the upper cover 10 and the lower cover 20 are not additionally required to fix the second yoke 120, thereby simplifying the entire structure of the actuator 100, reducing the fabrication time as well as greatly decreasing the fabrication cost.

(20) On the other hand, the stationary core 150 is located within the coil 140, and formed to have a circular cross section, so as to be brought into contact with or separated from the movable core 160.

(21) Furthermore, a first operating rod moving hole 151 is formed on the stationary core 150 to move in a state that the operating rod 170 is inserted thereinto, and a first elastic member accommodating portion 153 into which an elastic member 180 such as a spring is inserted is formed thereon to provide an elastic force to the operating rod 170.

(22) Here, a width of the first elastic member accommodating portion 153 is formed to be larger than that of the first operating rod moving hole 151 to form a first step 155 between the first elastic member accommodating portion 153 and the first operating rod moving hole 151.

(23) The movable core 160 is located within the coil 140, and formed to have a circular cross section, so as to be brought into contact with or separated from the stationary core 150 through the movement of the operating rod 170 or a magnetic force.

(24) Furthermore, a second operating rod moving hole 161 is formed on the movable core 160 to move in a state that the operating rod 170 is inserted thereinto, and a second elastic member accommodating portion 163 into which an elastic member 180 such as a spring is inserted is formed thereon to provide an elastic force to the operating rod 170.

(25) Here, a width of the second elastic member accommodating portion 163 is formed to be larger than that of the second operating rod moving hole 161 to form a second step 165 between the second elastic member accommodating portion 163 and the second operating rod moving hole 161.

(26) Accordingly, the elastic member 180 is located such that an end thereof is brought into contact with the first step 155 and the other end thereof is brought into contact with a movement adjuster 171 formed on the operating rod 170 in a state being inserted into the first elastic member accommodating portion 153 and the second elastic member accommodating portion 163, thereby providing an elastic force to the movable core 160.

(27) The operating rod 170 receives an elastic force of the elastic member 180 such as a spring in a state of being inserted into the first operating rod moving hole 151 and the second operating rod moving hole 161 to move the movable core 160 in an opposite direction to the stationary core 150.

(28) Here, the movement adjuster 171 is formed on an outer circumferential surface of the operating rod 170 such that an end of the movement adjuster 171 is brought into contact with the other end of the elastic member 180, and the other end of the movement adjuster 171 is brought into contact with the second step 165, thereby pressing the movable core 160 in an opposite direction to the stationary core 150 through an elastic restoring force of the elastic member 180.

(29) On the other hand, a magnetic strength formed on the main magnetic path and auxiliary magnetic path is adjusted through the first magnetic force adjustment plate 190 and the second magnetic force adjustment plate 210, and if a magnetic strength generated through a current applied to the coil 140 is A, and a magnetic strength due to the main magnetic path is B, and a magnetic strength due to the auxiliary magnetic path is C, then the relationship of A=B+C is established, and a magnetic strength (A) due to the main magnetic path is adjusted through the first magnetic force adjustment plate 190 and a magnetic strength due to the auxiliary magnetic path is adjusted through the second magnetic force adjustment plate 210.

(30) In other words, in case of the first magnetic force adjustment plate 190, the magnetic strength (A) due to the main magnetic path may be enhanced by increasing the thickness and number thereof or using a magnetic body, thereby enhancing a contact strength between the stationary core 150 and the movable core 160.

(31) In case of the second magnetic force adjustment plate 210, when it is made of a non-magnetic body, the auxiliary magnetic path formed through the second magnetic force adjustment plate 210 is formed through the non-magnetic body, and thus an effect of the auxiliary magnetic path on the main magnetic path is reduced to enhance a contact strength between the stationary core 150 and the movable core 160.

(32) Furthermore, when the second magnetic force adjustment plate 210 is formed with a magnetic body, a magnetic strength (B) due to the auxiliary magnetic path is enhanced to enhance a contact strength between the stationary core 150 and the movable core 160.

(33) Due to the foregoing configuration, when a current is applied to the coil 140 of the actuator 100 for a circuit breaker, a magnetic flux is generated, and thus a magnetic force is generated between the stationary core 150 and the movable core 160, thereby allowing the movable core 160 to be brought into contact with the stationary core 150 while pressing the elastic member 180 such as a spring in a direction of the stationary core 150. Here, the movable core 160 is in a state of receiving an elastic restoring force in an opposite direction to the stationary core 150 due to the spring.

(34) On the other hand, when a current applied to the coil 140 is suspended, a magnetic flux is not generated, and thus a magnetic force between the stationary core 150 and the movable core 160 disappears, thereby allowing the movable core 160 to be separated from the stationary core 150 while moving in an opposite direction of the stationary core 150 due to an elastic restoring force of the elastic member 180.

(35) A fabrication process of the actuator 100 for a circuit breaker according to an embodiment of the present disclosure will be described in detail with reference to FIGS. 6 through 8.

(36) First, the actuator 100 in which the second yoke 120 is not provided is fixed to a fixing jig 300 located in a vertical direction in a state that each constituent element such as the coil 140, permanent magnet 200 or the like is provided in the frame 500 (S101).

(37) Then, the second yoke 120 is closely adhered to the first yoke 110, and then a load is applied to the second yoke 120 using a load application member 400, thereby allowing the second yoke 120 to be fixed to the first yoke 110 and frame 500 (S103).

(38) Then, a contact strength (retaining force) due to a magnetic force of the stationary core 150 and the movable core 160 is measured, and the location of the second yoke 120 is adjusted when the measured contact strength is not greater than an elastic restoring force of the elastic member 180 (S105).

(39) At this time, as a separation distance between the second yoke 120 and the first yoke 110 increases, the extent of eliminating a magnetic force formed on the main magnetic path due to the first yoke 110 decreases by a magnetic force formed on the auxiliary magnetic path due to the second yoke 120, thereby increasing a contact strength between the stationary core 150 and the movable core 160.

(40) For example, when the measured contact strength between the stationary core 150 and the movable core 160 is less than an elastic restoring force applied to the movable core 160 through the elastic member 180, the stationary core 150 is not brought into contact with the movable core 160 even when a current is applied thereto, and thus the location of the second yoke 120 fixed through the load application member 400 is adjusted to be further away from the first yoke 110 to some extent, so as to increase a contact strength between the stationary core 150 and the movable core 160, thereby efficiently performing contact and separation between the stationary core 150 and the movable core 160 according to whether or not a current is applied thereto.

(41) Subsequent to adjusting the location of the second yoke 120, the engaging protrusion 111 is formed to finish the actuator 100 (S107).

(42) In case of the present disclosure, the actuator 100 for a circuit breaker is fabricated through the foregoing process to adjust the location of the second yoke 120 during the fabrication process so as to appropriately adjust a contact strength between the stationary core 150 and the movable core 160, thereby greatly enhancing the productivity of the actuator 100.

(43) While the present invention has been described in terms of its preferred embodiments, various alternatives, modifications and equivalents will be apparent to those skilled in the art, and it is clear that the invention is applicable in the same manner by appropriately modifying the above embodiments. Accordingly, the disclosure is not intended to limit the scope of the invention as defined by the limitation of the following claims.