Relay

Abstract

A relay according to one embodiment of the present invention includes a housing, a cylinder, a fixed contactor coupled to the housing, a movable contactor contactable with or separated from the fixed contactor, a coil assembly disposed in the housing to generate a magnetic field, a movable shaft coupled with the movable contactor at an upper portion thereof, a fixed core inserted into the cylinder, a moving core fixed to the movable shaft to move the movable shaft in a pressing manner, a wipe spring to supply elastic force to the movable shaft, and a return spring located between the fixed core and the moving core. The moving core includes a cylindrical protrusion extending toward the fixed core and surrounding the movable shaft.

Claims

1. A relay comprising: a housing; a cylinder coupled to an inner side of the housing; a fixed contactor coupled to the housing; a movable contactor located within the housing and configured to contact or separate from the fixed contactor; a coil assembly located in the housing and configured to generate a magnetic field when a current is applied; a movable shaft coupled with an upper portion of the movable contactor; a fixed core inserted into the cylinder and surrounding the movable shaft; a movable core fixed to the movable shaft and configured to move the movable shaft in response to the generated magnetic field; a wipe spring configured to supply elastic force to the movable shaft such that the movable contactor contacts the fixed contactor; and a return spring located between the fixed core and the movable core and surrounding the movable shaft, wherein the movable core comprises a cylindrical protrusion extending toward the fixed core and surrounding the movable shaft such that initial magnetic force between the fixed core and the movable core is increased, wherein the fixed core comprises a cylindrical accommodating portion configured to accommodate the cylindrical protrusion, wherein an inner circumferential surface of the cylindrical protrusion contacts the movable shaft and an outer circumferential surface of the cylindrical protrusion contacts an inner circumferential surface of the fixed core, wherein an end of the cylindrical protrusion comprises a chamfer, wherein the cylindrical accommodating portion is further configured to accommodate the return spring, wherein an upper end of the return spring contacts an end of the cylindrical accommodating portion, and wherein a lower end of the return spring contacts the chamfer such that the return spring does not enter the movable core and is elastically deformed between the end of the cylindrical accommodating portion and the cylindrical protrusion.

2. The relay of claim 1, wherein an outer diameter of the cylindrical protrusion is smaller than or equal to an inner diameter of the cylindrical accommodating portion.

3. The relay of claim 1, wherein the chamfer is formed at an angle of approximately 45.

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 sectional view of a relay having a moving core of a planar shape according to the related art;

(4) FIG. 2 is a perspective view of the moving core of FIG. 1;

(5) FIG. 3 is a sectional view of a relay having a corn-shaped moving core according to the related art;

(6) FIG. 4 is a sectional view illustrating a state that a protrusion of a moving core is accommodated in a fixed core in a relay in accordance with one exemplary embodiment of the present invention;

(7) FIG. 5 is a sectional view illustrating a state that the protrusion of the moving core is separated from the fixed core in the relay in accordance with the one exemplary embodiment of the present invention;

(8) FIG. 6 is a perspective view of a moving core illustrated in FIG. 4; and

(9) FIG. 7 is a graph showing intensity of magnetic force according to a distance between a moving core and a fixed core.

DETAILED DESCRIPTION OF THE DISCLOSURE

(10) Description will now be given in detail of a relay according to the present invention, with reference to the accompanying drawings. Explaining the features of the present invention, similar/like portions to those of the related art will briefly be described within a necessary range.

(11) FIG. 4 illustrates a relay 200 in accordance with one exemplary embodiment of the present invention. As illustrated in FIG. 4, a movable shaft 241 is movably located within a housing 210. A movable contactor 249 and moving core 245 are coupled to upper and lower portions of the movable shaft 241, respectively. The moving core 245 is coupled to the movable shaft 241 so as to move along with the shaft 241. When the moving core 245 is moved by magnetic force generated from a coil assembly 230, the movable shaft 241 and the movable contactor 249 move together, such that the movable contactor 249 can be brought into contact with a fixed contactor 220.

(12) The moving core 245 is located within a cylinder 260. The magnetic force which is generated when a current is applied to the coil assembly is transferred to the moving core 245. The moving core 245 which has received the magnetic force allows the movable shaft 241 to be moved in a pressing manner.

(13) The moving core 245 includes a protrusion 246. The protrusion 246 is a cylindrical member protruding toward the fixed core 243, and surrounds the movable shaft 241.

(14) As illustrated in FIG. 6, the protrusion 246 may be provided with a chamfer processed on one end thereof. The chamfer of the protrusion 246 may derive an improvement of an assembly property and a reduction of interference between the moving core 245 and a return spring 283. The chamfer of the protrusion 246 receives elastic force of the return spring 283. The chamber of the protrusion 246 may be formed at an angle of about 45 or formed within a range of facilitating an elastic deformation of the return spring 283. However, the present invention may not be limited to this, but be practiced in another embodiment illustrating a structure of a moving core having a cylindrical protrusion without a chamfer.

(15) The moving core 245 may be movable within the cylinder 260 by the magnetic force while coming in contact with an inner circumferential surface of the cylinder 260, or fixedly welded onto an outer side of the movable shaft 241. The protrusion 246 of the moving core 245 is formed integrally with the moving core 245.

(16) The fixed core 243 has a cylindrical shape and is fixed into the cylinder 260. The fixed core 243 is provided with a hole formed therethrough in a lengthwise direction thereof, so as to guide the movement of the movable shaft 241, which will be explained later.

(17) The fixed core 243 includes an accommodating portion 244. The accommodating portion 244 is a space in which the return spring 283 is located and the protrusion 246 is accommodated. The accommodating portion 244 may have an inner diameter which is wider than an outer diameter of the protrusion 246, or equal to the outer diameter of the protrusion 246 such that an inner circumferential surface of the accommodating portion 244 can come in contact with an outer circumferential surface of the protrusion 246.

(18) With the formation of the protrusion, when a current is applied to an excitation coil 233, the moving core 245 can be more closely adhered onto the fixed core 243. This may allow for generating stronger initial magnetic force between the fixed core 243 and the moving core 245, thereby improving an operation performance of the relay. The initial magnetic force, as aforementioned, refers to the magnetic force generated at the moment when a current is applied to a coil while the fixed core and the moving core are spaced apart from each other.

(19) A wipe spring 281 is located at an upper side of the movable shaft 241 in a contact state with the movable contactor 249. A return spring 283 may be located between the moving core 245 and the fixed core 243 or between the movable contactor 249 and the movable shaft 241.

(20) The wipe spring 281 may apply elastic force to the movable shaft 241 such that the movable contactor 249 can be brought into contact with the fixed contactor 220, and maintain contact pressure between contacts when the movable contactor 249 is in the contact state with the fixed contactor 220. The wipe spring 281 is elastically deformed by being pressed between the movable contactor 249 and the movable shaft 241.

(21) The return spring 283 applies elastic force to the moving core 245 such that the movable contactor 249 can be separated from the fixed contactor 220. The return spring 283 is elastically deformed by being pressed between the moving core 245 and the fixed core 243.

(22) The relay includes the housing 210. The housing 210 may further include a first housing 211 and a second housing 212.

(23) The first housing 211 may be located at an upper outer portion of the relay and coupled to a first barrier (not illustrated) which comes in contact with a part of a second barrier 218 to be explained later. The first housing 211 is divided into an arc-extinguishing area, in which the fixed contactor 220 and the movable contactor 249 come in contact with each other, and the other area. The first housing 211 may be made of a ceramic material for insulation. A pair of fixed contactors 220 is airtightly coupled to the first housing 211 through an upper surface of the first housing 211.

(24) The second housing 212 may be located at a lower outer side of the relay and coupled to the second barrier 218. The cylinder 260 is coupled to an actuator area defined by the second housing 212 and the second barrier 218, and a coil assembly 230 surrounds the cylinder 260.

(25) Hereinafter, description will be given in more detail of an operation of an embodiment of a relay according to the present invention with reference to FIGS. 4 and 5.

(26) First, as illustrated in FIG. 4, while a current is not applied to the coil assembly 230, elastic force of the return spring 283 is merely applied to the moving core 245. Hence, the movable shaft 241 is maintained in a downwardly-moved state, and accordingly the movable contactor 250 is spaced apart from the fixed contactor 220.

(27) Meanwhile, when a current is applied to the coil assembly 230 to magnetize the coil 233, magnetic flux generated in the coil 233 moves along the moving core 245, the fixed core 243, the second barrier 218 and the like, thereby forming a closed circuit. Accordingly, the moving core 245 is subject to magnetic force applied in an upward direction.

(28) The moving core 245 receives strong initial magnetic force at the moment of moving up, by virtue of the protrusion 246. Therefore, with high operation characteristic, the moving core can move along with the movable shaft 241 by receiving sufficient magnetic force.

(29) As illustrated in FIG. 5, the moving core 245 moves toward the fixed core 243 such that the protrusion 246 is accommodated in the fixed core 243. The movable contactor 249 accordingly comes in contact with the fixed contactor 220 and the wipe spring 281 is pressed.

(30) When the current supplied to the coil assembly 230 is cut off, the moving core 245 is moved downward along with the movable shaft 241 by the return spring 283, and accordingly the movable contactor 249 and the fixed contactor 220 are separated from each other.

(31) A graph of FIG. 7 shows initial magnetic force which is improved by the protrusion as one embodiment of the present invention. An x-axis indicates a distance between the moving core and the fixed core, and y-axis indicates strength of the magnetic force. As aforementioned, intensity of initial magnetic force at the moment of applying a current to the coil assembly has an important influence on the operation performance of the relay. Referring to the right side of the graph, the intensity of the magnetic force is about 2200 [g.Math.f] when there is the protrusion at a distance of 2.5 [mm] and about 1800 [gf] when there is no protrusion. It can thusly be noticed that there is not a great difference of the initial magnetic force.

(32) The foregoing detailed description is a detailed example as the embodiment of the present invention to be practiced by those skilled in the art, and not construed to limit the applicant's right. The applicant's right is defined by the utility registration claims to be described below.

(33) According to one embodiment of the present invention, a moving core of a relay is further provided with a protrusion. In an initial state that the moving core and a fixed core are spaced apart from each other, the protrusion can reduce a distance between the moving core and the fixed core. Accordingly, when a current is applied to a coil, strong initial magnetic force can be obtained. Consequently, an initial operation characteristic of the relay can be improved by virtue of the protrusion of the moving core.

(34) Also, with the structure of fixing a return spring using the protrusion, interference between the return spring and other relevant components, such as the moving core, the fixed core and a shaft, can be reduced, thereby improving assembly property.

(35) With the formation of the protrusion of the moving core, unnecessary abrasion between the return spring and the relevant components can be reduced, resulting in improvement of durability of the return spring and the like.