JP2008176942A - Gas-insulated switch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas-insulated switch preventing its diameter from enlarging in a simple structure by making an arc efficiently rotate, and with compactness and downsizing aimed at due to low operating force. <P>SOLUTION: An opposite side insulating member 17a is arranged at an opposite surface side of a non-contact recessed section 22 on spiral electrodes 15a and 15b, and a rear-face side insulator 17b having an equivalent or greater diameter is arranged at a rear face side of the spiral electrodes 15a and 15b. Even though a part of an outer periphery of the arc 26 is stuck out of an arc travelling section 23 toward the non-contact recessed section 22 side or outside the arc travelling section 23, a part of the current flowing in the arc 26 is prevented from flowing at the non-contact recessed section 22 astride a groove 24b or flowing at a rear face side of the spiral electrodes 15a and 15b by the opposite side insulating members 17a and 17b. Thus, electromagnetic force depending on a shape of the groove as a whole and magnitude of current can always be made to stably act on the arc 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a gas-insulated switch, and more particularly to a gas-insulated switch having an arc contact that is in electrical contact with each other in a closed state and ignites an arc when opened.

  In general, in gas-insulated switches, arc contacts are arranged to prevent damage to the current-carrying contactor or shield due to the arc generated at the time of opening, and the fixed-side conductor and the movable conductor are separated by a predetermined distance. A side conductor is arranged, an arc contact is arranged on the fixed side conductor, a mover is arranged on the movable side conductor, and an elastic contact member is provided at the tip of the arc contact or the mover. A structure in which arc contacts are electrically connected is known.

  In addition, a permanent magnet is disposed in the center of the arc contact, and a smooth continuous annular arc traveling part is provided at the tip of the arc contact to facilitate the rotation of the arc. In addition, a configuration is known in which the current interruption performance is improved by causing the arc to rotate with a permanent magnet (see, for example, Patent Document 1). Furthermore, an arc driving coil is arranged on the tip of the mover, and the arc is rotated in a short time using the magnetic force generated by the current flowing through the arc driving coil and the electromagnetic force generated by the current flowing through the arc when the current is interrupted. A configuration in which the arc is extinguished is known (see, for example, Patent Document 2). These gas-insulated switches can reduce the operating force compared to the gas spraying method and the high-speed operation side-by-side method, reducing the size and weight of the operating device, and reducing the operating force of the operating device. Excellent reliability and economy.

JP 2003-346611 A JP 58-204429 A

  However, the conventional arc-driven gas-insulated switch using electromagnetic force has the following problems. For example, in the case of an arc drive method using a permanent magnet, a design that takes into account the aging deterioration of the permanent magnet due to the temperature that changes depending on the current that flows during operation is required, and it takes a lot of time and effort to evaluate the degree of deterioration of the permanent magnet. Further, when the AC current is interrupted, the rotation direction of the arc is reversed every half cycle, so that it is not suitable in principle to efficiently drive the arc. In addition, in the case of an arc drive method using an arc drive coil, the arc drive coil must be disposed in the vicinity of the arc generating portion, or an insulation structure must be provided so that no current flows through the arc drive coil in a steady operation state. The structure of the same part was complicated and the outer diameter was large, which hindered downsizing of the equipment.

  An object of the present invention is to provide a gas-insulated switch that has a simple configuration and prevents an increase in diameter and efficiently rotates an arc to reduce the size and weight with a low operating force.

  In order to achieve the above-mentioned object, the present invention provides an arc contact, a fixed-side contact arranged so as to surround the arc contact, and the fixed-side contact and the arc in a sealed container filled with an insulating gas. A gas-insulated switch comprising a mover that contacts the contact and opens from the stationary contact prior to opening the arc contact, and at least one side of the mover and the arc contact facing each other A spiral electrode is provided at the tip, and the spiral electrode has an annular arc traveling portion located on the outer peripheral portion, a non-contact concave portion located inside the arc traveling portion, and a spiral extending from the arc traveling portion to the non-contact concave portion. A groove and a groove provided on the surface on the opposite side of the non-contact recess and generated by the arc running portion are formed in the non-contact recess. And having an opposite insulating material to prevent the ingredients of.

  The present invention according to claim 2 is characterized in that a back-side insulator having an outer diameter equal to or greater than that of the spiral electrode is disposed on the opposite side of the spiral electrode.

  In the gas insulated switch according to the present invention, by providing the facing insulating material on the facing surface of the non-contact recess in the spiral electrode, a part of the arc generated in the arc traveling portion of the spiral electrode straddles the groove of the non-contact recess. When crossing the groove of the non-contact recess, it is possible to reliably prevent the electromagnetic force that rotationally drives the arc in the arc running part from greatly decreasing due to a large change in the current loop. Stable shut-off performance can be obtained. Moreover, since a magnetic drive coil is not required as in the prior art, it is possible to prevent the diameter from increasing with a simple structure and efficiently rotate the arc without increasing the size of the vicinity of the arc generating portion, thereby reducing the operating force. Therefore, it is possible to realize a gas insulated switch that is reduced in size and weight.

  According to the second aspect of the present invention, a back-side insulator having an outer diameter equal to or larger than that of the spiral electrode is disposed on the opposite side of the spiral electrode, so that the arc generated in the arc traveling portion of the spiral electrode can be detected. It is possible to prevent a part from reaching the back surface side of the spiral electrode through the outer peripheral portion of the arc running portion. When a part of the arc reaches the back side of the spiral electrode, the electromagnetic force due to the current loop formed by the spiral groove is reduced by an amount corresponding to the current component, but this phenomenon is always prevented reliably. Thus, it is possible to realize a gas-insulated switch with a simple structure that prevents the increase in diameter and efficiently rotates the arc to reduce the size and weight with a low operating force.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a sectional view showing a closed state of the gas insulated switch according to the embodiment of the present invention. A gas compartment is formed in the hermetic container 1 by an insulating spacer 20, and in this gas compartment, a negative gas such as SF6 gas, dry air, nitrogen, carbon dioxide, SF6 / N2 mixed gas containing negative gas, An N2 / O2 mixed gas or the like that does not contain a negative gas is enclosed as an insulating gas. High voltage conductors 11 and 12 arranged to face each other with a predetermined insulation distance in a state of being electrically insulated from the hermetic container 1 are supported and fixed to the embedded conductors at the center of the insulating spacer 20. , 12 are provided with electric field relaxation shields 7, 8 respectively. The mover 2 disposed on the high voltage conductor 11 side is configured to be movable on its axis via an insulating operation rod 3 by an external operation device (not shown). In addition, a movable contact 6 is disposed inside the high voltage conductor 11, and the movable element 2 always maintains an electrical connection state with the high voltage conductor 11 by the movable contact 6.

FIG. 1 is an enlarged view of a main part of the gas insulated switch shown in FIG.
An arc contact frame 9 is fixed to the high voltage conductor 12 side. In the arc contact frame 9, a spring 10 and an arc contact 5 urged by the spring 10 so as to move to the mover 2 side by a predetermined distance are provided. Has been placed. A stationary contact 4 is arranged between the arc contact mount 9 and the electric field relaxation shield 8 surrounding the outer periphery thereof, and electrically connects the tip of the movable element 2 and the arc contact mount 9 in the closed state. is doing. Although detailed illustration is omitted, the arc contact 5 can be moved within the arc contact frame 9 by a spring 10 by a certain distance, and the electrical connection between the arc contact 5 and the arc contact frame 9 is good even during this movement. A current collector is disposed on the sliding portion so as to be held at the bottom.

  The opposite ends of the mover 2 and the arc contact 5 are provided with spail electrodes 15a and 15b, which will be described in detail later. These spail electrodes 15a and 15b are substantially disk-shaped, and the outer diameter thereof is smaller than the outer diameter of the mover 2 so that the moving operation is not prevented by contact with the stationary contact 4. Yes. The spail electrode 15a is attached after forming a small-diameter portion 5a whose outer diameter is once reduced at the front end portion of the arc contact 5 on the opposite side. Similarly, the spail electrode 15b is once attached to the front end portion of the movable element 2 on the opposite side. It is attached after forming the small diameter portion 2a having a small diameter.

  In the closed state of the gas-insulated switch, the movable element 2 has its opposite end inserted into the electric field relaxation shield 8 to come into contact with the fixed contact 4 and a spail electrode 15b provided at the opposite end is provided. A spail electrode 15b is pressed against the sparile electrode 15a, and the spring 10 biased through the arc contact 5 at this time is provided with a spail electrode 15b provided at the tip on the opposite side of the mover 2, and a spail electrode provided on the tip on the opposite side of the arc contact 5 A moderate contact pressure is applied between 15a. In a closed state, the high voltage conductor 11... Movable side contact 6... Mover 2... Fixed side contact 4... Arc contact frame 9. ... movable side contact 6 ... mover 2 ... spiral electrode 15b ... spiral electrode 15a ... arc contact 5 ... current collector 16 ... arc contact mount 9 ... a current path called high voltage conductor 12 is formed. ing. Therefore, since the temperature rise at the time of electricity supply by contact resistance can be suppressed rather than the case where the arc contact 5 is not provided, the outer diameter of the needle | mover 2 can be made thinner than before.

Next, a specific structure of the spail electrodes 15a and 15b will be described. Since both have substantially the same structure, the spail electrode 15b will be described here.
FIG. 3 is a plan view seen from the opposite side of the spail electrode 15b, and the spail electrode 15b is connected to a small diameter portion 2a formed on the opposite side of the mover 2 on the back side of the center portion. A non-contact recess 22 having a larger diameter than the small-diameter portion 2a is formed in the center portion on the opposite side of the spiral electrode 15b, and a substantially annular arc running portion 23 is formed on the outer periphery of the non-contact recess 22. ing. Three continuous spiral grooves 24 extending from the outer peripheral surface to the vicinity of the small-diameter portion 2a are formed in the non-contact concave portion 22 and the arc running portion 23 on the opposite side of the spail electrode 15b.

  Since these three spiral grooves 24 have substantially the same shape, only one will be described. The arc traveling portion 23 has its outer periphery so as to intersect with an imaginary straight line serving as the radius of the spail electrode 15b with an inclination angle. Along the outer circumference of the groove 24a cut obliquely from the groove, the groove 24b formed in an arc shape by a predetermined length in the non-contact concave portion 22 adjacent to the arc running portion 23, and the small-diameter portion 2a of the non-contact concave portion 22 A series of continuous spiral grooves 24 is formed from a groove 24d formed at a predetermined length at a position and a groove 24c connecting the groove 24b and the groove 24d. The opening angle α of the spiral groove 24, that is, the opening angle α between a virtual straight line connecting the center of the spiral electrode 15 b and the outer peripheral end of the spiral groove 24, and a virtual straight line connecting the center of the spiral electrode 15 b and the inner peripheral end of the spiral groove 24. Is approximately 180 degrees.

  The spail electrode 15a that forms a pair with the spail electrode 15b has the same configuration. In the absence of the series of spiral grooves 24 described above, an electromagnetic driving force acts on the arc generated between the points A in the opposing portions of both the spail electrodes 15a and 15b in the radial direction of the spail electrodes 15a and 15b. However, a circumferential component of the electromagnetic driving force acting on the arc is increased by the electrode shape and the spiral groove 24 described above, and the arc can be rotationally driven along the annular arc traveling portion 23.

4 and 5 are a plan view and a cross-sectional view after the opposing-side insulator 17a is disposed in the non-contact recess 22 formed on the opposing side of the spiral electrode 15b shown in FIG.
As can be seen from the figure, on the opposite side of the spiral electrode 15b, almost the entire non-contact recess 22 is covered with the opposite-side insulator 17a except for the annular arc running part 23, and the arc generated in the arc running part 23 A part of the outer peripheral portion of the coil is prevented from easily passing over the spiral groove 24 formed in the non-contact recess 22. Various methods of attaching the opposing insulator 17a are conceivable. Here, a through hole is formed at the center of the opposing insulator 17a, and the small diameter portion 2a side is formed through the through hole from the opposing side of the spiral electrode 15b. Even when the arc traveling portion 23 of the spiral electrode 15a and the spiral electrode 15b forming a pair is in contact with each other, the opposing-side insulator 17a is not in contact so that mechanical strength is not added. Is arranged.

  As an electrode material constituting the spiral electrodes 15a and 15b, an alloy mainly composed of copper and tungsten, copper and chromium, or copper and alumina, which is resistant to arc heat, is conceivable. As the insulating member of the opposing insulator 17a, when the insulating gas in the sealed container 1 is SF6 gas, PTFE, insulating paper, nylon, alumina, etc. are used, and in the case of an insulating gas containing oxygen, Use flame-retardant material such as PTFE.

Next, the current interruption operation of the above-described gas insulated switch will be described.
When the insulating rod 3 is rotated clockwise by an external operation unit (not shown) from the closed state of FIG. 2 to apply a contact opening operation force, the mover 2 moves in the right opening direction. First, the mover 2 is separated from the stationary contact 4 shown in FIG. 1, and the current path flowing through the contact is cut off. However, since the arc contact 5 is in the state of compressing and energizing the spring 10 in the closed state, the spiral electrode 15a, 15b moves in the opening direction in a pressed state, and flows through this contact portion. The current path is maintained. At this time, since the opening of the spiral electrode 15a is delayed by a certain distance by the spring 10 so as to follow the spiral electrode 15b on the movable element 2 side, the stationary contact 4 is arced between itself. Does not occur and is not affected by the heat, so that stable energization performance can be maintained over a long period of time.

  Thereafter, as shown in FIG. 6, when the spiral electrode 15 a moves to a position slightly retracted from the electric field relaxation shield 8, the movement of the arc contact 5 is blocked by the arc contact mount 9. Accordingly, the subsequent opening operation of the mover 2 opens the spiral electrodes 15 a and 15 b, and an arc 26 is generated between the arc traveling portions 23. The arc 26 is subjected to electromagnetic force by the configuration of the spiral electrodes 15a and 15b that form a pair as described above and the cut-off current, and is affected by the insulating gas while rotating the annular arc traveling portion 23. The current is interrupted by extinguishing the arc at the current zero point.

  When the opening operation is completed, the mover 2 moves into the movable-side electric field relaxation shield 7 as shown in FIG. 7, and the spiral electrode 15 b at the tip on the opposite side is slightly smaller than the electric-field relaxation shield 7. The position is set backward. The spiral electrodes 15a and 15b have a shape in which the electric field tends to concentrate as compared with the opposite end of the movable element 2, but in the opened state, both spiral electrodes 15a and 15b are opposite ends of the electric field relaxation shields 7 and 8, respectively. By stopping at a position slightly retracted inward from the portion, the electric field on the opposite side of the spiral electrodes 15a and 15b can be kept low, and the gap can be well insulated.

  Incidentally, the arc 26 shown in FIG. 6 has a certain thickness, and has a characteristic that the current density near the center is high and the current density decreases as the distance from the center increases. Accordingly, even the arc 26 generated between the arc traveling portions 23 is not entirely located on the arc traveling portion 23, and the outer peripheral portion thereof is slightly separated from the arc traveling portions 23 of the spail electrodes 15a and 15b. It may end up. For example, since it may spread to the non-contact recess 22 side located inside the arc running portion 23, if there is no opposing insulating member 17a, a part of the current flowing through the arc 26 also flows in the non-contact recess 22. For example, a part of the current flows even on the non-contact recess 22 side across the groove 24b of the spiral groove 24. In this case, the current loop formed by the spiral groove 24 changes greatly, and the electromagnetic force depending on the shape of the spiral electrode including the spiral groove 24 and the magnitude of the current decreases.

  However, as described above, since the opposing insulating member 17a is provided on the opposing surface side of the non-contact recess 22 in the spiral electrodes 15a and 15b, the outer peripheral portion of the arc 26 protrudes from the arc running portion 23 to the non-contact recess 22 side. Even so, a part of the current flowing through the arc 26 by the opposing insulating member 17a does not flow in the non-contact recess 22 across the grooves 24b of the spiral electrodes 15a and 15b. For this reason, the electromagnetic force depending on the shape of the entire groove and the magnitude of the current can always be stably applied to the arc 26, and the arc 26 can be forcibly rotated at high speed in an insulating gas. Thus, the arc 26 is easily extinguished by the cooling action during the rotational motion, and a stable current interrupting performance can always be maintained. In this way, it is possible to obtain a gas-insulated switch that is reduced in size and weight by reducing the operating force of the operating device and reducing the diameter of the mover 2.

  The above description has been made on the side of the spail electrode 15b. However, since the structure of the spail electrode 15a formed so that the spiral grooves 24 overlap with each other in the contact state is the same, the same effect can be obtained on both sides of the spail electrode 15a, 15b. Obtainable. Further, in other usage forms, a spail electrode may be used for only one of the movable element 2 and the arc contact 5, and substantially the same effect can be expected by the opposing insulating member 17a.

  The opposing insulating members 17a provided on the opposing surfaces of the non-contact recesses 22 in the spiral electrodes 15a and 15b do not necessarily need to be disposed on the entire non-contact recess 22, and the arc 26 generated between the arc running portions 23 is not necessarily required. It is only necessary that a part does not exceed the groove 24 b of the non-contact recess 22. For example, you may arrange | position the opposing side insulation member 17a only to the outer peripheral part of the non-contact recessed part 22 located in the arc running part 23 side. This is because the groove 24b formed in an arc shape by a predetermined length is formed in the non-contact concave portion 22 at a position adjacent to the arc running portion 23. The groove 24b formed in the arc shape is formed from the arc running portion 23. When formed slightly apart, the opposing insulating member 17a disposed on the outer periphery of the non-contact recess 22 as described above may not be used. In this case, the part of the arc 26 flows through the non-contact recess 22 is the groove portion connecting the arc-shaped groove 24b and the groove 24a of the arc running portion 23, so that the opposite-side insulation is at least near the groove portion. What is necessary is just to arrange | position the member 17a. Further, as described above, the opposing insulating member 17a may be an insulator of another member arranged on the opposing side of the non-contact recess 22 or may be an insulating coating obtained by molding the entire opposing side of the non-contact recess 22.

  In order to prevent a part of the arc 26 generated between the arc running portions 23 from exceeding the groove 24b of the non-contact recess 22, it is conceivable to increase the width of the spiral groove 24 to some extent. However, in this case, it is conceivable that part of the arc or metal vapor or the like due to the arc passes through the spiral groove 24 to the back side of the spirale electrodes 15a and 15b, so that the non-contact recessed portion 22 is provided with the opposing insulating member 17a. The width of the spiral groove 24 is preferably 10 mm or less.

FIG. 8 is a plan view showing a spiral electrode 15b of a gas insulated switch according to another embodiment of the present invention.
The spiral electrode 15b has two spiral grooves 24 having substantially the same shape. Non-contact in the vicinity of the boundary between the arc running portion 23 and the groove 24a cut obliquely from the outer periphery of the arc running portion 23 so as to intersect the virtual straight line serving as the radius of the spiral electrode 15b with an inclination angle. A groove 24b formed in the recess 22 in an arc shape longer than the case of FIG. 3, a groove 24d formed in a non-contact recess 22 at a position along the outer periphery of the small diameter portion 3a, a groove 24b, and a groove 24d. A series of continuous spiral grooves 24 are formed from the grooves 24c connecting the two. The opening angle α of the spiral groove 24, that is, the opening angle α between a virtual straight line connecting the center of the spiral electrode 15 b and the outer peripheral end of the spiral groove 24, and a virtual straight line connecting the center of the spiral electrode 15 b and the inner peripheral end of the spiral groove 24. Is about 240 degrees. Since the opening angle α is larger than 180 degrees of FIG. 3, it is possible to further increase the electromagnetic force of the circumferential component acting on the arc.

FIG. 9 is a plan view showing a spiral electrode 15b of a gas insulated switch according to another embodiment of the present invention.
This spiral electrode 15 b has only one spiral groove 24. Non-contact in the vicinity of the boundary between the arc running portion 23 and the groove 24a cut obliquely from the outer periphery of the arc running portion 23 so as to intersect the virtual straight line serving as the radius of the spiral electrode 15b with an inclination angle. A groove 24b formed in an arc shape in the recess 22 longer than that in FIG. 8, and a groove 24d formed in the non-contact recess 22 at a position along the outer periphery of the small diameter portion 3a considerably longer than in FIG. A series of continuous spiral grooves 24 are formed from the grooves 24b and the grooves 24c connecting the grooves 24d. The opening angle α of the spiral groove 24 is 360 degrees or more. Also in this embodiment, since the opening angle α is larger than in the case of FIGS. 3 and 8, it is possible to further increase the electromagnetic force of the circumferential component acting on the arc.

  As can be understood from the description of each embodiment described above, the electromagnetic force of the circumferential component acting on the arc can be further increased by increasing the length or opening angle α of the spiral groove 24. According to the above, it is desirable that the opening angle α is 180 degrees or more. As the opening angle α is increased, the spiral electrodes 15a and 15b forming a pair are in contact with each other with a contact pressure applied in a closed state, which may cause a problem in mechanical strength. Since the grooves 24b, 24c, and 24d are covered with the opposing insulating member 17a, part of the arc does not exceed these groove portions 24b to 24d. Therefore, the groove width is set to 10 mm or less to prevent a decrease in mechanical strength. can do. Alternatively, except for the arc running surface 23, the non-contact concave portion 22, the spiral groove 24, and the back surface side of the spiral electrode may be molded with an insulator to form an integrated structure to increase the mechanical strength.

FIG. 10 is a cross-sectional view illustrating a state in the middle of opening of a gas insulated switch according to still another embodiment of the present invention. The same reference numerals are given to the equivalents of the embodiment shown in FIG. The detailed explanation is omitted.
The spiral electrode 15b attached to the mover 2 has a back-side insulator 17b attached to the opposite side in addition to the opposite-side insulator 17a disposed in the non-contact recess 22 formed on the opposite side. As shown in FIG. 12, which is an enlarged view of the main part, the movable element 2 is formed with a small-diameter portion 2a having an outer diameter smaller than that of the non-contact concave portion 22 of the spiral electrode 15b at the tip, and this small-diameter portion 2a. A center hole of the disc-shaped back-side insulator 17b is inserted into and inserted between the mover 2 and the spiral electrode 15b. The rear surface side insulator 17b has an outer diameter equal to or larger than that of the spiral electrode 15b.

  The spiral electrode 15a attached to the arc contact 5 is also provided with a back side insulator 17b on the back side in addition to the opposing side insulator 17a disposed in the non-contact recess 22 formed on the opposite side. As shown in FIG. 13 which is an enlarged view of the main part, the arc contact 5 is formed with a small diameter portion 5a having an outer diameter smaller than that of the non-contact concave portion 22 of the spiral electrode 15a at the tip portion. The center hole of the disk-like back surface side insulator 17b is inserted and fixed to. The rear surface side insulator 17b has an outer diameter equal to or larger than that of the spiral electrode 15a. These back-side insulators 17b can be attached in various other structures.

  At least the opposite side of the electric field relaxation shield 8 provided so as to surround the outer periphery of the spiral electrode 15a is provided with an insulator 18a whose surface is coated or molded, and surrounds the outer periphery of the spiral electrode 15b. At least the opposite side of the provided electric field relaxation shield 7 is provided with an insulator 18b whose surface is coated or molded. With these insulators 18a and 18b, the withstand voltage between the opposing portions of both electric field relaxation shields 7 and 8 is improved, and the movable element 2 is made smaller in the axial direction by reducing the insulating distance between the opposing portions. Can do. The opposite-side tips of the open spiral electrodes 15a and 15b are stopped at a position slightly retracted from the opposite-side tips of the electric field relaxation shields 7 and 8.

  As described above, the arc 26 generated between the arc traveling portions 23 of the pair of spiral electrodes 15a and 15b has an outer peripheral portion from the arc traveling portion 23 even if the center portion is located on the arc traveling portion 23. May come off. When a part of the arc 26 is further out of the outer periphery than the arc traveling portion 23, between the large diameter portion 5b of the arc contact 5 and the back surface of the arc traveling portion 23 on the back surface side of the spail electrode 15a, or the back surface side of the spail electrode 15b. Thus, the current component flows directly between the large diameter portion 2 b of the mover 2 and the back surface of the arc traveling portion 23. When such a current component flows, originally, a desired electromagnetic force is obtained by utilizing the spiral groove 24 by energizing through the small diameter portion 2a of the mover 2 and the small diameter portion 5a of the arc contact 5. On the other hand, the electromagnetic force is reduced similarly to the phenomenon in the non-contact recess 22 described above.

  However, as shown in FIG. 12, a back-side insulator 17b is arranged in the small diameter portion 2a of the mover 2 so as to shield between the spail electrode 15b and the large diameter portion 2b of the mover 2, and FIG. As shown in the figure, since the back-side insulator 17b is arranged in the small diameter portion 5a of the arc contact 5 so as to shield between the large diameter portion 5b of the spail electrode 15a and the arc contact 5, a part of the arc 26 is part of the spail electrode 15a. 15b, even if it protrudes to the outer peripheral side of the arc running part 23, it is shielded by the rear surface side insulator 17b, and it is possible to prevent direct energization on the rear surface side of the outer peripheral part of the spail electrodes 15a, 15b. be able to. Therefore, the entire current component can always flow through the small diameter portions 2a and 5a to obtain a desired electromagnetic force using the spiral groove 24, and the arc 26 is forced to rotate at high speed in the insulating gas. As a result of the cooling action during the rotational movement, the arc 26 is easily extinguished, and a stable current interrupting performance can always be maintained.

  Further, by making the outer diameter of the back-side insulator 17b equal to or greater than the outer diameter of the spiral electrodes 15a, 15b, the tip of the mover 2 and the arc contact 5 is caused by plasma or metal vapor generated by the arc 26. It can also prevent damage. Furthermore, the insulation withstand voltage between the opposing portions of the electric field relaxation shields 7 and 8 is improved by the insulators 18a and 18b, and the opposite ends of the spiral electrodes 15a and 15b from the opposite ends of the electric field relaxation shields 7 and 8. Since the distance for retracting the tip can also be made smaller than in the case of FIG. 1, the length of the movable element 2 and the arc contact 5 including the spiral electrodes 15a and 15b can be shortened to further reduce the size of the device. It is.

  The above-described gas insulated switch according to the present invention can be applied to other than the configuration shown in FIG.

It is sectional drawing which shows the closing state of the gas insulated switch by one embodiment of this invention. It is sectional drawing which shows the whole structure of the gas insulated switch shown in FIG. It is a front view of the spiral electrode which is the principal part of the gas insulated switch shown in FIG. It is a front view which shows the state which attached the opposing insulator to the spiral electrode shown in FIG. It is sectional drawing of the spiral electrode shown in FIG. It is sectional drawing which shows the state in the middle of the opening of the gas insulated switch shown in FIG. It is sectional drawing which shows the opening state of the gas insulated switch shown in FIG. It is a front view of the spiral electrode which is the principal part of the gas insulated switch by other embodiment of this invention. It is a front view of the spiral electrode which is the principal part of the gas insulation switch by further another embodiment of this invention. It is sectional drawing which shows the state in the middle of the opening of the gas insulated switch by further another embodiment of this invention. It is sectional drawing which shows the opening state of the gas insulated switch shown in FIG. It is sectional drawing which shows one spiral electrode of the gas insulated switch shown in FIG. It is sectional drawing which shows the other spiral electrode of the gas insulated switch shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Movable element 2a Small diameter part 2b Large diameter part 4 Fixed side contact 5 Arc contact 5a Small diameter part 5b Large diameter part 9 Arc contact mount 10 Spring 15a, 15b Spiral electrode 17a Opposite side insulator 17b Back surface side insulator 18a, 18b Insulator 24 Spiral groove 26 Arc

Claims (2)

  An arc contact, a fixed-side contact arranged so as to surround the arc contact, and a contact with the fixed-side contact and the arc contact and opening of the arc contact in a sealed container filled with an insulating gas In the gas insulated switch provided with a mover that separates from the stationary contact prior to the spiral contact, a spiral electrode is provided at the front end of at least one of the mover and the arc contact. An annular arc running portion located on the outer periphery, a non-contact recess located inside the arc running portion, a spiral groove extending from the arc running portion to the non-contact recess, and a surface on the opposite side of the non-contact recess And a counter-side insulating material that prevents a part of the arc generated in the arc traveling portion from straddling a groove formed in the non-contact recess. Gas insulated switchgear, characterized in that.   The gas-insulated switch according to claim 1, wherein a back-side insulator having an outer diameter equal to or greater than that of the spiral electrode is disposed on the opposite side of the spiral electrode.

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