Electromagnetic contactor

Abstract

An electromagnetic contactor includes: a lower frame having an accommodation space therein; a bobbin having a fixed core, and accommodated in the lower frame; a movable core inserted into the bobbin so as to be moveable up and down; a spring installed between the bobbin and the movable core, and configured to provide an upward restoration force to the movable core; and a b contact switch installed at one side of the bobbin, wherein a button for operating a switch lever of the b contact switch is provided at a movable core plate positioned above the movable core.

Claims

1. An electromagnetic contactor, comprising: a lower frame comprising an opening defining an accommodation space; a bobbin comprising a fixed core and configured to be accommodated in the lower frame; a movable core configured to be inserted into the bobbin and moveable up and down; a spring disposed between the bobbin and the movable core and configured to provide an upward restoration force to the movable core; a b contact switch disposed at one side of the bobbin; a movable core plate disposed above the movable core; a button disposed at the movable core plate and configured to operate a switch lever of the b contact switch as the movable core is moved up and down; an extension portion extending from a front surface of the movable core plate; and an insertion portion disposed at the extension portion and comprising a groove configured to accommodate the button, wherein the button is formed as an elastic member and is fixedly coupled to the insertion portion.

2. The electromagnetic contactor of claim 1, wherein the insertion portion comprises an opening defining an opening portion and a fixing portion, wherein a width of the opening portion is smaller than a width of the fixing portion.

3. The electromagnetic contactor of claim 1, wherein the button comprises a button body having a cylindrical shape and a circumferential groove along an outer circumferential surface of the button body.

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 exemplary embodiments 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 of an electromagnetic contactor in accordance with the conventional art;

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

(5) FIG. 3 is a perspective view illustrating a state where a movable core of FIG. 1 is inserted into a bobbin;

(6) FIG. 4 is a longitudinal sectional view of an electromagnetic contactor in accordance with the conventional art;

(7) FIG. 5 is an exploded perspective view of an electromagnetic contactor according to an embodiment of the present invention;

(8) FIG. 6 is a perspective view of a movable core assembly according to an embodiment of the present invention;

(9) FIG. 7 is a perspective view illustrating a state where a movable core of FIG. 5 has been assembled into a bobbin; and

(10) FIG. 8 is a longitudinal sectional view of a button according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(11) Description will now be given in detail of preferred configurations of an electromagnetic contactor according to the present invention, with reference to the accompanying drawings.

(12) FIG. 5 is an exploded perspective view of an electromagnetic contactor according to an embodiment of the present invention. FIG. 6 is a perspective view of a movable core assembly according to an embodiment of the present invention. FIG. 7 is a perspective view illustrating a state where a movable core of FIG. 5 has been assembled into a bobbin. Various embodiments of the present invention will be explained in more detail with reference to the attached drawings.

(13) The electromagnetic contactor according to an embodiment of the present invention includes a lower frame 10 having an accommodation space therein; a bobbin 20 having a fixed core 21, and accommodated in the lower frame 10; a movable core 40 inserted into the bobbin 20 so as to be moveable up and down; a spring 30 installed between the bobbin 20 and the movable core 40, and configured to provide an upward restoration force to the movable core 40; and a b contact switch 27 installed at one side of the bobbin 20. A movable core plate 42, which is positioned above the movable core 40, is provided with a button 46 for operating a switch lever 28 of the b contact switch 27.

(14) The lower frame 10 has a box shape where an upper surface is open, and the bobbin 20, the spring 30 and the movable core 40 to be explained later are accommodated in the lower frame 10. The lower frame 10 is detachably coupled to an upper frame 60 where a holder assembly 50 is mounted.

(15) The holder assembly 50, accommodated in the upper frame 60, is provided with movable contacts 51. A fixed contact (not shown) is installed at two-side terminal walls 25 disposed above the bobbin 20. In case of a three-phase AC power, fixed contacts may be disposed at a power side and a load side for each phase, in parallel.

(16) The bobbin 20 is provided with a bobbin body (not shown) long formed in upper and lower directions at a central part thereof. A fixed core 21 is installed around the bobbin body. Fixed core insertion portions 22 are provided at an upper end and a lower end of the bobbin 20.

(17) The bobbin body (not shown) is provided with a cavity (hollow portion) 24 therein, and the movable core 40 is insertable into the bobbin body through the cavity 24. A coil (not shown) is wound on the bobbin body. Accordingly, if an external power is applied to the coil (not shown), a magnetic field is generated.

(18) A printed circuit board 26 having an electronic circuitry portion is provided on a front surface of the bobbin 20, and the b contact switch 27 is installed at the printed circuit board 26. The b contact switch 27 serves to supply a current to the coil (not shown), or to disconnect power supply to the coil. In a normal state, the b contact switch 27 is in an on state. On the contrary, when the switch lever 28 is pressed, the b contact switch 27 is in an off state.

(19) The holder assembly 50 is installed in the upper frame 60 so as to be moveable up and down, and is provided with movable contacts 51 protruding toward a power side and a load side in parallel.

(20) The movable contacts 51 are elastically supported by elastic springs, and are disposed above fixed contacts (not shown) with a distance therebetween. As aforementioned, the movable contacts 51 may be provided with the same number as phases.

(21) The movable core 40 has a cylindrical structure, and is inserted into the bobbin 20. The movable core 40 includes a body portion 41 having a cylindrical shape, a movable core plate 42 coupled to an upper part of the body portion 41, and a coupling plate 44 having a U-shape and coupled to an upper surface of the movable core plate 42.

(22) As the body portion 41 of the movable core 40 is inserted into the cavity 24 of the bobbin 20, the movable core 40 is moveable up and down. In this case, a movement force is provided from the holder assembly 50 to which the coupling plate 44 is fixed.

(23) An extension portion 43 protrudes from a front surface of the movable core plate 42, and an insertion portion 45 for inserting a button 46 to be explained later is formed on a front surface of the extension portion 43. The insertion portion 45 may be formed as a groove of a gourd bottle.

(24) The button 46 is fixed into the insertion portion 45. The button 46 is formed as a circumferential groove 48 to be fitted into the insertion portion 45 is formed at a button body 47 having a cylindrical shape. The button 46 performs an up-down motion by being installed at the movable core plate 42. The button 46 presses the switch lever 28 while downward moving.

(25) The button 46 may be formed as an elastic member. The elastic member may be formed of rubber, fiber, etc. As the button 46 is formed as the elastic member, an impact generated when a force is applied to the switch lever 28 is attenuated. This can increase durability and reduce damage.

(26) An operation of the electromagnetic contactor according to an embodiment of the present invention will be explained in more detail.

(27) Once a current of an external power is applied to a coil (not shown) through the b contact switch 27, a magnetic field is generated around the coil. And the bobbin 20 and the fixed core 21 are magnetized by the magnetic field. The movable core 40 is sucked into the fixed core 21 by a magnetic force generated from the magnetized bobbin 20 and fixed core 21, thereby being moved downward. As a result, the movable contact 51 comes in contact with the fixed contact (not shown), so that a current flows from a power side to a load side.

(28) The button 46, coupled to the extension portion 43 of the movable core 40, presses the switch lever 28 while moving downward. As the switch lever 28 is pressed, the b contact switch 27 is in an off state, and a current from an external power flows into the coil with a value reduced through a resistance (not shown). As a result, a contacted state between the movable contact 51 and the fixed contact is maintained.

(29) FIG. 8 illustrates another embodiment of the button 46 applied to the electromagnetic contactor according to the present invention.

(30) Button bodies 47a, 47b may include a first button body 47a having a cylinder shape, and a second button body 47b having a piston shape. A coil spring 49 is disposed between the first button body 47a and the second button body 47b, thereby providing an elastic force. Since the first button body 47a and the second button body 47b are elastically moveable, they may be formed of various materials such as synthetic resin or steel.

(31) 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 construed 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.