Contact of vacuum interrupter

Abstract

A contact of a vacuum interrupter comprises a contact body portion formed in the shape of a circular plate, having a contact surface in a flat shape on one surface thereof, and provided with a plurality of cut portions formed in a spiral shape from a center of the contact surface toward an outer side in a radial direction, and an inclination area formed between the contact surface and an outer circumferential surface of the contact body portion, wherein the inclination area is provided with multi-stage inclined portions each forming a multi-stage inclination along the outer side of the contact body portion in the radial direction.

Claims

1. A contact of a vacuum interrupter, the contact comprising: a contact body portion formed in the shape of a circular plate, and having a contact surface formed in a flat shape on one surface of the contact body portion, wherein the contact body portion is provided with a plurality of cut portions formed in a spiral shape from a center of the contact surface toward an outer side in a radial direction; and an inclination area formed between the contact surface and an outer circumferential surface of the contact body portion, wherein the inclination area is provided with multi-stage inclined portions each forming a multi-stage inclination along the outer side of the contact body portion in the radial direction, wherein each of the multi-stage inclined portions comprises a first inclined surface downwardly inclined to have a first inclination angle with respect to the contact surface, and a second inclined surface extending from the first inclined surface and having a second inclination angle with respect to the first inclined surface, the second inclination angle being steeper than the first inclination angle, and wherein the first inclined surface is formed in a curved shape, and the second inclined surface is formed in a linear shape.

2. The contact of claim 1, further comprising auxiliary inclined portions formed between the contact surface and each of inner walls formed on the contact body portion by the plurality of cut portions, the auxiliary inclined portions downwardly inclined into a multi-stage shape from the contact surface.

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 a view of a vacuum interrupter according to the related art;

(4) FIG. 2 is a side view showing a contact of the related art vacuum interrupter;

(5) FIG. 3 is a planar view showing the contact of the related art vacuum interrupter;

(6) FIG. 4 is a view showing a configuration of a vacuum interrupter in accordance with the present invention;

(7) FIG. 5A is a cross-section showing a contact of the vacuum interrupter in accordance with the present invention;

(8) FIG. 5B is an enlarged view of a portion of the vacuum interrupter of FIG. 5A.

(9) FIG. 6 is a planar view showing the contact of the vacuum interrupter in accordance with the present invention; and

(10) FIG. 7 is a view illustrating another embodiment of multi-stage inclined portions in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(11) A detailed description of a contact of a vacuum interrupter according to the present invention will now be given with reference to the accompanying drawings.

(12) FIG. 4 is a view showing a configuration of a vacuum interrupter in accordance with the present invention.

(13) As illustrated in FIG. 4, the vacuum interrupter according to the present invention may include an insulating container 9, a movable electrode 1, a movable contact 100, a fixed electrode 4, a fixed contact 200, a fixed-side seal cup 8, a movable-side seal cup 7, a bellows tube 5, a bellows tube shield 6, and a center shield 10.

(14) The insulating container 9 which is a container for accommodating the components of the vacuum interrupter, and may be formed of ceramic which is an electric insulating material. The insulating container 9 may be formed in a cylindrical shape.

(15) The movable electrode 1 may be connected to a driving force transfer member, such as a rod, a lever or a link (not shown) so as to be linearly movable by a driving force transferred through the driving force transfer member. The movable electrode 1 may be configured as a conductive material.

(16) The movable electrode 1 may be electrically connected to a load side of an electric power circuit.

(17) The movable contact 100 may be attached to an upper end of the movable electrode 1 which faces the fixed electrode 4. The movable contact 100 may be made of a metal having characteristics, such as conductivity, resistance to fusion, current breaking, and high voltage withstand capability.

(18) The fixed electrode 4 which is located at a fixed position may be disposed to face the movable electrode 1, and electrically connected to a power source side of the electric power circuit, for example.

(19) The fixed contact 200 may be attached to a lower end of the fixed electrode 4 which faces the movable electrode 1. The fixed contact 200 may be made of the same material and in the same shape as the movable contact 100.

(20) A detailed description of the movable contact and the fixed contact according to the present invention will be given as below.

(21) The fixed-side seal cup 8 refers to a member in the shape of a cup with a low height so as to air-tightly close one of openings at both ends of the ceramic insulating container 9, namely, one opening at which the fixed electrode 4 is disposed. The fixed-side seal cup 8 may be provided with a through hole formed through a center thereof such that the fixed electrode 4 is inserted therethrough.

(22) The fixed-side seal cup 8 may be air-tightly welded on the ceramic insulating container 9 and the fixed electrode 4.

(23) The movable-side seal cup 7 refers to a member in the shape of a cup with a low height so as to air-tightly close one of the openings at the both ends of the ceramic insulating container 9, namely, one opening at which the movable electrode 1 is disposed. The fixed-side seal cup 8 may be provided with a through hole formed through a center thereof such that the movable electrode 1 is inserted therethrough.

(24) The movable-side seal cup 7 may be air-tightly welded on the ceramic insulating container 9 and the bellows tube 5.

(25) The bellows tube 5 may be implemented as a metal tube which has a hollow inside such that the movable electrode 1 is inserted therethrough, and has a plurality of folds with flexibility so as to allow the movement of the movable electrode 1.

(26) One end portion of the bellows tube 5 may be welded on the movable-side seal cup 7, and another end portion thereof may be welded on the bellows tube shield 6.

(27) The bellows tube shield 6 may be implemented as a metal member in the shape of a cup which surrounds the bellows tube 5 to protect the bellows tube 5 from arc, which is generated when the movable contact 2 is separated from the fixed contact 3, and metal vapors generated by the arc.

(28) A penetrating portion formed at the center of the bellows pipe shield 6 may be welded on a flange which protrudes from an outer circumferential surface of the movable electrode 1, such that the bellows tube shield 6 can be linearly moved together with the movable electrode 1. Simultaneously, another end portion of the bellows tube 5 can also be linearly moved together.

(29) The center shield 10 may be supported by a shield supporting shaft 11 which is inserted into the ceramic insulating container 9, and also protect an inner wall of the ceramic insulating container 9 from the arc and the metal vapors.

(30) Hereinafter, the configurations of the movable contact and the fixed contact disposed in the vacuum interrupter will be described.

(31) In the following description, the configuration of the movable contact will be described representatively because the movable contact and the fixed contact have the same configuration.

(32) As illustrated in FIGS. 5A, 5B and 6, the movable contact 100 according to the present invention may have a contact body portion 110 with a contact surface A on an upper surface thereof.

(33) Here, as illustrated in FIG. 6, an inclination area E with a predetermined width may be formed between the contact surface A and an outer circumferential surface C of the contact body portion 110.

(34) The contact body portion 110 may generally be formed in the shape of a circular plate.

(35) The contact body portion 110 may be provided with a plurality of cut portions 111 formed in a spiral shape from a center thereof to an outside in a radial direction. By the formation of the cut portions 111, a plurality of spiral petal portions 112 may be formed between the cut portions 111.

(36) Here, as illustrated in FIG. 4, the movable contact 100 and the fixed contact 200 have the same shape, and they may be disposed to face each other in a vertical direction.

(37) The contact surfaces A of the movable contact 100 and the fixed contact 200 may be brought into contact with each other upon a closing operation, and spaced apart from each other upon an opening operation.

(38) The contact surface A may correspond to the remaining portion except for the inclination area E and be formed as a flat surface.

(39) The inclination area E of the contact body portion 110 may include multi-stage inclined portions 120.

(40) Each of the multi-stage inclined portions 120 may be formed on the contact body portion 110, and have a multi-stage inclination formed toward an outer side b in a radial direction of the contact body portion 110 at the inclination area E.

(41) The multi-stage inclination may be an inclination with two stages or more.

(42) The present invention exemplarily illustrates that each of the multi-stage inclined portions 120 forms a two-stage inclination.

(43) Each of the multi-stage inclined portions 120 may be provided with a first inclined surface 121 and a second inclined surface 122.

(44) The first inclined surface 121 may be downwardly inclined toward an outer side in the radial direction so as to have a first inclination angle θ1 with respect to the contact surface A.

(45) Also, the second inclined surface 122 may extend from the first inclined surface 121. Here, the second inclined surface 122 may be downwardly inclined toward the outer side in the radial direction so as to have a second inclination angle θ2 with respect to the first inclined surface 121. The second inclination angle θ2 may be greater than the first inclination angle θ1.

(46) Therefore, the first inclination angle θ1 may be formed smoother than the second inclination angle θ2 on the basis of the contact surface A.

(47) That is, the multi-stage inclination may form inclination angles which gradually get steeper from an edge of the contact surface A toward the outer side of the contact body portion 110.

(48) Hereinafter, an operation in case where the contacts having such configuration is disposed in the vacuum interrupter will be described.

(49) The fixed contact 200 and the movable contact 100 according to the present invention may be formed in the same configuration.

(50) As illustrated in FIG. 4, the fixed contact 200 may be fixed to a lower end of the fixed electrode 4, and the movable contact 100 may be fixed to an upper end of the movable electrode 1.

(51) Each of the contact surface A of the fixed contact 200 and the contact surface A of the movable contact 100 may have a flat shape and the surfaces A of the movable contact 100 and the fixed contact 200 may be disposed to face each other.

(52) In this state, in case of opening a vacuum circuit breaker after closed, when the movable electrode 1 is moved down by a driving force transfer member (not shown), the movable contact 100 and the fixed contact 200 may be separated from each other and arc may be generated at the moment.

(53) In this instance, the arc is rotated by the spiral petal portions 112, in particularly, the first inclined surface 121, by a force, which is generated by interaction between an arc current flowing along the arc electrically connecting the movable contact 2 and the fixed contact 3 and a radial magnetic field generated by the arc current. Accordingly, the arc is evenly extinguished on surfaces of the movable contact 100 and the fixed contact 200.

(54) The second inclined surface 122 of each of the multi-stage inclined portions 120 in the present invention may more increase a spaced distance between the fixed contact 200 and the movable contact 100, as compared with the case illustrated in FIG. 1, which may decrease an electric field generated between the fixed contact 200 and the movable contact 100, thereby ensuing insulating capability.

(55) Consequently, the first inclined portion 121 according to the present invention may increase arc-extinguishing efficiency by inducing rotation of the arc, and the second inclined portion 122 may improve the insulating capability between the fixed contact 200 and the movable contact 100, thereby preventing damages on the fixed contact 200 and the movable contact 100.

(56) The present invention has been described under assumption that the first inclination angle θ1 of the first inclined surface 121 is set in the range of 10 to 15° and the second inclination angle θ2 of the second inclined surface 122 is set in the range of 20 to 25°.

(57) The reason of setting the first and second inclination angles θ1 and θ2 of the first and second inclined surfaces 121 and 122 may be as follows. Namely, the first inclination angle θ1 of the first inclined surface 121 may be set in the range of 10 to 15° to ensure arc extinguishing capability between the contacts, and the second inclination angle θ2 of the second inclined surface 122 may be set in the range of 20 to 25° to ensure the insulating capability between the contacts.

(58) FIG. 7 is a view illustrating another embodiment of the multi-stage inclined portions in accordance with the present invention.

(59) As illustrated in FIG. 7, each of multi-stage inclined portions 120′ may include a first inclined surface 121′ formed in a curved shape and a second inclined surface 122 formed in a linear shape.

(60) When the first inclined surface 121′ is formed in the curved shape, as aforementioned, the first inclined surface 121′ may induce rotation of arc such that the arc generated on the contact surface A upon the opening operation of the vacuum circuit breaker can be extinguished by the curved first inclined surface 121′.

(61) Also, the second inclined surface 122 may has a linear inclination steeper than the first inclined surface 121′. This may sufficiently increase a spaced distance between the second inclined surfaces 122 of the respective fixed and movable contacts 200 and 100, so as to reduce an electric field, thereby improving the insulating capability between the fixed contact 200 and the movable contact 100.

(62) Although not illustrated, the first inclined surface and the second inclined surface may also be formed to have different curvatures.

(63) Preferably, the curvature of the first inclined surface may be greater than the curvature of the second inclined surface.

(64) Therefore, arc generated upon separating the contacts may be distributed by the first inclined surface with the different curvature from the second inclined surface, and also a sufficient distance for reducing the electric field can be ensured by the second inclined surface.

(65) Also, in order to reduce an electric field, the second inclined surface may preferably be wider in width than the first inclined surface.

(66) In addition, as illustrated in FIGS. 5A, 5B, auxiliary inclined portions f which are downwardly inclined into multiple stages from the contact surface A may further be formed between the contact surface A and each of inner walls 111a (see FIG. 6) which are formed at the contact body portion 110 defined by the plurality of cut portions 111.

(67) The auxiliary inclined portions f may be formed in the same configuration as the first and second inclined surfaces, so detailed description thereof will be omitted.

(68) According to the present invention, an arc distribution, namely, arc-extinguishing efficiency can be improved by the formation of the multi-stage inclined portions and also an insulating performance can be ensured by reducing an electric field at each petal portion.

(69) This may result in easily solving the problem that the contacts are fused or deformed due to the concentration of the electric field on the plurality of petal portions which are formed by the plurality of cut portions.

(70) Meanwhile, when a plural form such as “(the) contacts” is used, it should be understood as referring to a movable contact and a fixed contact, separately. On the other hand, when a singular form such as “a (the) contact” is used, it should be understood as referring to one of the movable contact and the fixed contact.

(71) The foregoing description has been given of the detailed embodiments related to the contact of the vacuum interrupter, but it may be obvious that different variations can be made without departing from the scope of the present invention.

(72) Therefore, 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.

(73) That is, the aforementioned embodiments are merely illustrative and should not be understood to be limited thereto. Also, 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.