JP2015220094A - Opening/closing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an opening/closing device which opens and closes a cable way of a power system and prevents abrasion of a contact point and opening failure due to metal particles generated by arc.SOLUTION: Disclosed is an opening/closing device 20 in which a movable contact point 1 having a finger contact 1a provided therein moves inside of a cylindrical fixed contact point 2 in the axial direction. In an insulation part 3 of the outer peripheral part of the fixed contact point 2, an insulation crown part 3a is formed having a through-hole 3c through which the movable contact point 1 penetrates so as to cover the end 2a of the fixed contact point 2. The inner diameter Dof the through-hole 3c is smaller than the outer diameter Dof the finger contact 1a.

Description

  The present invention relates to a switchgear such as a disconnector or a circuit breaker that opens and closes an electric circuit of an electric power system, and particularly relates to improvement of a contact point structure of the switch.

In a conventional buffer type gas circuit breaker, a fixed arc contact of an axial conductor and an arc contact movable in the axial direction of the fixed arc contact are placed in a tank filled with an arc extinguishing gas. A movable arc contact that contacts and separates from the fixed arc contact by being put in and out of the lumen is arranged, and the arc generated in the opening gap between the fixed arc contact and the movable arc contact is blown out by the compressed gas. A technique in which the movable arc contact side of the contact is formed in a spiral shape is disclosed (for example, Patent Document 1).
Further, the contact type electronic component is a sliding contact electronic component in which a conductor portion is formed on the surface of the insulating substrate so that the slider is in sliding contact, and the surface of the conductor portion and the insulating substrate surface on the locus of the slider are on the same surface. A technique is disclosed in which a gap is formed between the sliding contact end portion of the conductor portion and the insulating substrate, which is narrower than the contact portion of the slider (for example, Patent Document 2).

JP-A-8-315696 Japanese Utility Model Publication No.5-1120

  However, in the circuit breaker shown in Patent Document 1 above, when arranged in the horizontal direction with respect to the driving direction of the movable contact, metal particles are generated from the contact due to wear due to friction between the contacts and melting due to arcing, The metal particles are scattered on the insulating member. When metal particles are present between the contacts, the metal particles re-ignite, resulting in an increase in arc time. As the arc time increases, contact damage increases, and there is a problem in that a large amount of metal particles causes poor opening. Further, the contact structure as described in Patent Document 2 is applied to a small current region of a contact of an electronic component, and when used in a large current region such as a power system, a large amount of metal particles are generated by an arc. Therefore, when metal particles are generated between the fixed contact and the insulating member so as to exceed the capacity of the gap, the metal particles are scattered on the insulating member, and as with the above-mentioned Patent Document 1, the opening failure is accompanied by an increase in arc time. There is a problem of causing.

  The present invention has been made to solve the above-described problems, and has a configuration in which metal particles generated by contact wear and arcing are not scattered on the insulating portion, so that the electric power can be reliably transferred between the insulating portion and the contact. An object of the present invention is to provide a switchgear that can be divided in an automatic manner and that can prevent an increase in arc time, thereby suppressing damage caused by the arc and causing no poor opening.

  According to a first aspect of the present invention, in the switchgear having a movable contact that moves in the axial direction inside a cylindrical fixed contact, the movable contact is provided with a finger contact that contacts the fixed contact. The insulating portion provided on the outer periphery of the contact is formed with an insulating crown portion having a through hole through which the movable contact passes so as to cover the end of the fixed contact, and the inner diameter of the through hole is outside the finger contact. It is smaller than the diameter.

  According to a second aspect of the present invention, there is provided a switchgear having a movable contact that moves in an axial direction inside a fixed contact formed in a cylindrical shape. A finger contact is provided at the end of the fixed contact, and the outer diameter of the leading insulating portion is larger than the inner diameter of the finger contact.

  According to the switchgear according to the first aspect of the present invention, the metal particles generated from the contact are prevented from entering the insulating crown due to wear of the movable contact and the fixed contact or melting damage caused by the arc. It is possible to reliably electrically separate the gaps between the two, and by preventing an increase in the arc time, there is an effect that the damage due to the arc can be suppressed and the opening failure does not occur.

  Further, according to the switchgear according to the second invention, the metal particles are prevented from entering the contact surface between the leading insulating portion and the fixed contact, and the same effect as the first invention can be obtained.

3 is a cross-sectional view showing a closed state of the switchgear according to Embodiment 1. FIG. FIG. 3 is a diagram showing a finger contact according to the first embodiment. FIG. 3 is a cross-sectional view showing an opening state of the switchgear according to Embodiment 1. It is sectional drawing which shows the closing state of the switchgear by Embodiment 2. It is sectional drawing which shows the opening state of the switchgear by Embodiment 2. FIG. 6 is a sketch diagram illustrating a finger contact according to a second embodiment. FIG. 6 is a cross-sectional view showing a contact opening state of a switchgear according to Embodiment 3. It is sectional drawing which shows the opening state of the switchgear by Embodiment 4. It is sectional drawing which shows the opening state of the switchgear by Embodiment 5.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings. FIG. 1 is a conceptual cross-sectional view showing a main part of the switchgear 20 in a closed state. The switchgear 20 is installed in a tank filled with an insulating gas (not shown). In FIG. 1, a cylindrical finger contact 1a shown in FIG. The movable contact 1 is movable by a not shown drive unit in the axial direction (horizontal direction) in FIG. 1, the finger contact 1a slides in contact with the inside diameter D _S of the fixed contact 2 formed in a cylindrical shape . As shown in FIG. 3, a predetermined corner curvature R or a predetermined chamfer is provided on the inner diameter side of the end 2a of the fixed contact 2, and the corner S between the end 2a and the insulating crown 3a is provided. Is formed. In yet closed state shown in FIG. 1, the inner diameter D _S of the outer diameter D _F and the fixed contact 2 fingers contact 1a are equal. An insulating portion 3 made of an insulating material is provided on the outer peripheral portion of the fixed contact 2, and an insulating crown portion 3 a is formed so as to cover the end portion 2 a of the fixed contact 2. The insulating crown 3a has a predetermined length L _2, and has a through hole 3c of the inner diameter D _3. Further, the movable contact 1 finger contact 1a is provided with a predetermined length L ₁ has a movable contact outer diameter D _4, an inner diameter D _3> movable contacts outer diameter D ₄ of the insulating crown 3a is there.

Next, the finger contact 1a of the movable contact 1 will be described with reference to the drawings. FIG. 2 shows an example of the finger contact 1a. The metallic finger contact 1a formed in a cylindrical shape has a plurality of slits 1b on the circumference. Further, the finger contact 1a, together with an outer diameter D _F, has an inner diameter D _5, the inner diameter D ₅ parts of the end face of the finger contact 1a, and has a predetermined length L _3. If this reason the movable contact 1 as shown in FIG. 3 in the open electrode state moves, the inner diameter D ₅ side outer diameter D _F is in contact with the finger contact 1a to the inside diameter D ₃ of the through hole 3c of the insulating crown 3a To bend and deform. Conversely when inserting the movable contact 1 into the inner diameter D _S side of the fixed contact 2, so that the contact pressure is applied to the inner diameter D _S by the elastic force of the fixed contact 2 fingers contact 1a. The material of the movable contact 1 and the finger contact 1a may be formed using the same metal material or different materials. Further, the end 2a and the base 2b of the fixed contact 2 may be made of the same metal material or different materials. That is, different metal materials may be used for the portion where the arc is generated and the energized portion, or the same metal material may be used. Examples of the material for the insulating portion 3 and the insulating crown portion 3a include polytetrafluoroethylene, polyacetal, acrylate copolymer, aliphatic hydrocarbon resin, polyvinyl alcohol, polybutadiene, polyvinyl acetate, polyvinyl acetal, and isoprene resin. A combination of any one or more of ethylene propylene rubber, ethylene vinyl acetate copolymer, polyamide resin and the like is suitable. When the materials as described above are used for the insulating portion 3 and the insulating crown portion 3a, the surface of the insulating portion 3 and the insulating crown portion 3a evaporates and decomposed gas is generated by contact of the arc generated when the switchgear 20 operates. (This phenomenon is called ablation). Since the arc can be cooled by the latent heat of vaporization when the insulating portion 3 and the insulating crown portion 3a are vaporized, the arc is easily extinguished. Thus, if the material excellent in ablation is used, it will become possible to improve interruption | blocking performance. In the case of a three-phase alternating current, for example, the switchgear 20 shown in FIG. 1 is provided in parallel with a necessary number corresponding to the number of phases with a predetermined interval therebetween.

Next, the operation of the opening / closing device 20 will be described with reference to FIGS. In the closed state shown in FIG. 1, the movable contact 1 and the fixed contact 2 are joined, and energization is performed in this state. Subsequently, the movable contact 1 moves to the left in FIG. 1 and starts to open by a driving device (not shown) that operates in response to an opening command signal from the outside. 3 to move the movable contact 1 and reaches the insulating crown 3a, since the inner diameter D ₃ of the through hole 3c of the insulating crown 3a is smaller than the outer diameter D _F of the finger contact 1a, insulating deflected finger contact 1a is It passes through the crown 3a. As shown in FIG. 3, in the open state where the contact between the end 2a of the fixed contact 2 and the finger contact 1a is separated, the energized state is turned off. In the first embodiment, since the insulating crown portion 3a is provided so as to cover the insulating portion 3 surrounding the outside of the fixed contact 2 and the end portion 2a, the metal particles 4 generated by arc or wear are insulated from the finger contact 1a. The end of the fixed contact 2 formed by the inner diameter D _S of the fixed contact 2> the inner diameter D ₃ of the insulating crown ₃ a and the corner curvature R of the fixed contact 2 while preventing entry into the contact surface with the crown 3 a Metal particles 4 accumulate in the corner S between the portion 2a and the insulating crown 3a. As a result, the switchgear can be made compact and capable of reliably performing electrical interruption, preventing an increase in arc time, suppressing the damage caused by the arc, and preventing the occurrence of poor opening.

Embodiment 2. FIG.
Next, the opening / closing device 20 according to the second embodiment will be described. FIG. 4A is a conceptual cross-sectional view showing the main part of the switchgear 20 in a closed state as in the first embodiment. Yes and tipping insulating portion 3b to the distal end portion 1c of the embodiment 2, the movable contact 1 of this embodiment is provided, also finger contact 2c having a length L ₁ to the end portion 2a of the fixed contact 2 is provided. Above with the insulating portion 3b has an outer diameter D ₆ and has a length L _3. Here, the finger contact 2c has a shape similar to the structure shown in FIG. 2 described in the first embodiment, but the finger contact 2d shown in FIG. 6 can be used as another shape. A finger contact 2d shown in FIG. 6 is formed in a cylindrical shape, and a metal plate-like contact 11 formed in a plate shape is formed on a support plate 10 having a plurality of grooves in the circumferential direction. A coil spring (not shown) is arranged so as to surround the outer surface A of the plate-like contact 11. When this finger contact 2d is used for the fixed contact 2 of the second embodiment, the movable contact 1 or the leading insulating portion 3b contacts the inner surface B of the plate contact 11, so that the tip of the plate contact 11 is the inner surface. Deformation from B to outer surface A direction. Then, contact pressure is applied to the movable contact 1 or the leading insulating portion 3b by the elastic force resulting from the deformation.

Next, the operation will be described with reference to FIGS. In the closed state of FIG. 4A, the movable contact 1 and the fixed contact 2 are coupled and energized. Subsequently, the movable contact 1 starts to be opened by an external opening command signal. FIG. 5 is a cross-sectional view of the opening / closing device 20 in the separated state. Beginning to the movable contact 1 is opening, that reaches the above with an insulation portion 3b, since the outer diameter D ₆ of the above with an insulation portion 3b is larger than the inner diameter D ₇ of the finger contact 2c, taking the above with an insulation portion 3b The hook contacts 2c are separated by bending. The tip portion 1c of the movable contact 1, since the above with an insulation portion 3b having a larger outer diameter D ₆ than the outer diameter D ₄ of the movable contact 1 is arranged, the metal particles 4 generated by the arc and wear, It accumulates in the corner S of the joint portion between the movable contact 1 and the leading insulating portion 3b, and therefore can be reliably electrically separated between the leading insulating portion 3b and the movable contact 1, thereby preventing an increase in arc time. Therefore, damage due to the arc is suppressed, and no poor opening occurs. FIG. 4B shows an example in which a stepped portion 1d is provided at the tip 1c of the movable contact 1 as another embodiment. A corner S is formed between the stepped portion 1d and the leading insulating portion 3b, and the same effect as described above can be obtained.

Embodiment 3 FIG.
Next, a third embodiment will be described. FIG. 7 is a sectional view of the opening / closing device 20 in the open state, in which a gap portion 5 is provided between the end portion 2a of the fixed contact 2 and the insulating crown portion 3a of the insulating portion 3, and other configurations are carried out. It is the same as that of FIG. In the switchgear 20 having such a configuration, the metal particles 4 generated by arcing or wear enter the gap portion 5 and prevent the metal particles 4 from entering the contact surface between the insulating crown portion 3a and the finger contact 1a. Therefore, an increase in arc time is prevented, damage due to the arc is suppressed, and an effect of not causing poor opening is produced.

Embodiment 4 FIG.
A fourth embodiment is shown in FIG. The insulating part 3 according to the fourth embodiment is provided with exhaust ports 6 at a plurality of locations on the circumference of the insulating part 3 corresponding to the gap part 5 shown in the third embodiment. This is the same as the third embodiment. In addition, the number of exhaust ports 6 and the installation position in the circumferential direction are not particularly limited, and may be arranged at one or more locations where metal particles 4 are likely to accumulate. There is no need to arrange them symmetrically. In the embodiment 4 configured as described above, the metal particles 4 that have entered the gap portion 5 due to arcing or wear are removed by the exhaust port 6, thereby preventing an increase in arc time and damage caused by the arc. Suppresses and does not cause poor opening.

Embodiment 5 FIG.
FIG. 9 is a sectional view showing the opening / closing device 20 in the open state according to the fifth embodiment. In the fifth embodiment, a permanent magnet 7 is embedded in an insulating crown 3a, and is arranged so that a magnetic field is applied to the fixed contact 2 and the movable contact 1. Other configurations are the same as those in the first, third, and fourth embodiments. The permanent magnet 7 is arranged in the direction of the N pole, the S pole, or the S pole, the N pole along the axial direction, that is, the moving direction of the movable contact 1. Further, the permanent magnet 7 may be embedded integrally in the insulating crown 3a, or may be configured separately and incorporated into the insulating crown 3a at the time of assembly. The shape of the permanent magnet 7 may be a cylindrical shape or a ring shape, or a cylindrical shape may be arranged on the circumference. In the fifth embodiment configured as described above, the arc rotates by receiving a force in the circumferential direction by the magnetic field generated by the permanent magnet 7. That is, since the arc rotates, the interruption performance is improved by suppressing the temperature rise of the fixed contact 2 and the movable contact 1 and cooling effect of forced convection. At the same time, the arc has a characteristic of extending along the magnetic field in the opening direction of the movable contact 1, and the arc is attracted to the permanent magnet 7. Since the periphery of the permanent magnet 7 is covered and protected by the insulating portion 3 and the insulating crown portion 3a, the arc attracted by the permanent magnet 7 comes into contact with the insulating portion 3 and the insulating crown portion 3a, so that the decomposition gas is generated. Since the arc is cooled by the latent heat of vaporization when the cracked gas is generated, the interruption performance can be improved.

  It should be noted that within the scope of the present invention, the embodiments can be freely combined, or the embodiments can be appropriately modified or omitted.

1 movable contact, 1a finger contact, 1c tip, 1d gap,
2 fixed contact, 2a end, 2c finger contact, 3 insulation, 3a insulation crown, 4 metal particles, 5 gap, 6 exhaust, S corner, R corner curvature, 20 switchgear.

Claims (10)

In a switching device provided with a movable contact that moves in the axial direction inside a cylindrical fixed contact, the movable contact is provided with a finger contact that contacts the fixed contact, and an outer periphery of the fixed contact An insulating crown portion having a through hole through which the movable contact passes is formed so as to cover an end portion of the fixed contact, and an inner diameter of the through hole is outside the finger contact. A switchgear characterized by being smaller in diameter. In a switching device provided with a movable contact that moves in the axial direction inside a fixed contact formed in a cylindrical shape, a disc-shaped leading insulating portion is provided at the tip of the movable contact, and the fixed contact A switchgear characterized in that a finger contact is provided at an end of the contact, and an outer diameter of the leading insulating part is larger than an inner diameter of the finger contact. Either the corner curvature or chamfering is applied to the inner diameter side of the end portion of the fixed contact in contact with the insulating crown portion, and a corner portion is formed between the end portion and the insulating crown portion. The switchgear according to claim 1, wherein The switchgear according to claim 1, wherein a gap is provided between the insulating crown and the end of the fixed contact. The switchgear according to claim 4, wherein an exhaust port is provided on a circumference of a portion corresponding to the gap portion of the insulating portion. The permanent magnet is provided in the said insulation crown part so that a magnetic field may be applied to the said movable contact and the said fixed contact, The any one of Claims 3-5 The switchgear described in 1. The insulating part and the insulating crown part are materials excellent in ablation, and any one kind or a plurality of kinds of materials are used in combination. The switchgear according to claim 6. The distal end portion of the movable contact is subjected to either a corner curvature or a chamfer to form a corner portion between the leading insulating portion and the leading insulating portion. The switchgear according to claim 2. The switchgear according to claim 2, wherein a stepped portion is provided at the tip of the movable contact, and a corner is formed between the tip insulating portion. The said leading insulation part is a material excellent in ablation, Comprising: Arbitrary 1 type or several types of material is used in combination, The claim 2, Claim 8, or Claim 9 characterized by the above-mentioned. The switchgear according to any one of the above.

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