Link mechanism of circuit breaker and circuit breaker

Abstract

To improve wear resistance without impairing a current-carrying performance of a conductor case of a two-point vacuum circuit breaker.SOLUTION: A link mechanism 22 of a circuit breaker includes: a conductor case 2 constituting a current path between vacuum interrupters 16; a pair of link parts 6 accommodated in the conductor case 2; a shaft part 13 rotatably connecting each link part 6 to each vacuum interrupter 16; and a rolling member 12 at both ends of the shaft part 13. A mounting hole 25 is formed in opposite side walls 2a of the conductor case 2, and a frame-shaped guide member 26 is mounted on an inner peripheral surface of the mounting hole 25. The guide member 26 has a pair of guide holes 26a. Each of the rolling members 12 is rollably disposed in each of the guide holes 26a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a double-break vacuum circuit breaker technology. [Background technology]

[0002] In recent years, in response to the increasing voltage and capacity of vacuum circuit breakers, a type has been proposed in which two vacuum interrupters are connected in series to improve voltage resistance (see Patent Documents 1 and 2). This type is called a double-break vacuum circuit breaker, and the voltage applied to the circuit breaker is shared by each vacuum interrupter.

[0003] A double-break vacuum circuit breaker has vacuum interrupters arranged in a grounded tank and a link mechanism that opens and closes each vacuum interrupter to perform a breaking operation. Explained with reference to Figure 8, the link mechanism 1 includes a conductor case 2 that forms a conductive path between each vacuum interrupter 16, and a pair of link parts 6 housed within the conductor case 2.

[0004] A connecting member 11 disposed inside the conductive case 2 is attached to the movable lead 3 of each vacuum interrupter 16. A spring 4 is interposed between the connecting member 11 and the conductive case 2, and the movable lead 3 is biased by the spring 4.

[0005] The upper end portion 5a of the insulating operating rod is inserted into the conductor case 2, and each link portion 6 has a pair of link portions 6 that move in response to the up and down movement of the insulating operating rod. Each link portion 6 has links 6a and 6b formed in similar, approximately triangular shapes.

[0006] Links 6a and 6b are rotatably connected to the upper end 5a of the insulating operating rod via shaft 8, rotatably supported on the side wall 2a of the conductor case 2 via shaft 9, and rotatably connected to a connecting member 11 via shaft 13. Cylindrical iron rolling members (rollers) 12 are attached to both ends of this shaft 13, and each rolling member 12 is rotatably housed in a pair of guide holes 10 formed in the upper part of the opposing side wall 2a. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2007-188734 [Patent Document 2] Patent Publication No. 2016-127744 Summary of the Invention [Problem to be solved by the invention]

[0008] According to the configuration of Figure 8, when the insulating operating rod is pushed upward during the closing operation, the links 6a and 6b rotate in the X direction, pushing out the movable lead 3 and bringing the movable electrode into contact with the fixed electrode, thereby closing the circuit.

[0009] On the other hand, when the insulating operating rod is pulled downward during the breaking operation, the links 6a and 6b rotate in the direction of the arrow Y, which attracts the movable lead 3 and separates the movable electrode from the fixed electrode, opening the circuit and breaking the current.

[0010] During such opening and closing operations, the rolling member 12 rolls on the inner periphery of the guide hole 10 formed in the side wall 2a of the conductive case 2. However, since the conductive case 2 is an electrical path, a highly conductive material is used, and the allowable surface pressure on the inner periphery of the guide hole 10 is low.

[0011] On the other hand, high-voltage circuit breakers require high-speed operation, so it is necessary to improve the wear resistance of the inner circumference of the guide hole 10. In this case, the conductor case 2 must be silver-plated because it is a current-carrying path as described above, but it is difficult to use it in combination with surface treatments such as anodizing that improve surface hardness, which may affect current-carrying performance.

[0012] The present invention has been made to solve the problems of the prior art, and has as its object to improve the wear resistance of the conductor case of a vacuum circuit breaker without impairing the current-carrying performance of the conductor case. [Means for solving the problem]

[0013] (1) One aspect of the present invention is a link mechanism for a circuit breaker that opens and closes a pair of vacuum interrupters arranged in a grounded tank filled with insulating gas in response to the operation of an insulating operating rod, a conductive case that forms a current path between the vacuum interrupters; a pair of links housed in the conductor case; a shaft portion that rotatably connects each of the links to each of the vacuum interrupters; rolling members provided on both ends of the shaft member; a pair of mounting holes formed opposite to each other in the conductive case; a guide member provided on the inner periphery of each mounting hole; Equipped with The rolling members are disposed in the guide members so as to be capable of rolling freely.

[0014] (2) It is preferable that each of the guide members is formed in a frame shape. In this case, the guide members have a pair of guide holes, and each of the rolling members is disposed in each of the guide holes.

[0015] (3) Alternatively, a recess may be formed on the inner peripheral edge of the mounting hole, and a protrusion that fits into the recess may be formed on the outer peripheral edge of the guide member. In this case, it is preferable that the recess be formed on the inner peripheral edge of the outer side of the conductive case, and the protrusion be formed on the outer peripheral edge of the conductive case. Note that a conductive cover may be provided to close the mounting hole after the fitting, and a sealing member may be provided to seal between the conductive cover and the conductive case.

[0016] (4) Another aspect of the present invention is a vacuum circuit breaker, a grounded tank filled with insulating gas; a pair of vacuum interrupters disposed within the grounded tank; an insulating operating rod for operating the opening and closing of each vacuum interrupter; The link mechanism opens and closes each of the vacuum interrupters in response to operation of the insulating operating rod. [Effects of the Invention]

[0017] According to the present invention, it is possible to improve the wear resistance of the conductor case of the vacuum circuit breaker without impairing the current-carrying performance of the conductor case. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a longitudinal sectional view of a double-break vacuum circuit breaker to which a link mechanism according to an embodiment of the present invention is applied; [Figure 2] Enlarged view of part A in Figure 1. [Figure 3] FIG. [Figure 4] Figure: Longitudinal cross section of link mechanism [Figure 5] FIG. [Figure 6] Cross section B-B of Figure 5. [Figure 7] Enlarged view of part C in Figure 6. [Figure 8] FIG. 10 is a partial cross-sectional view showing a conventional link mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0019] The link mechanism of a circuit breaker according to an embodiment of the present invention will be described below. This link mechanism is applied to a double-break vacuum circuit breaker, similar to the conventional example (FIG. 8). Here, the same components as those in the conventional example will be described using the same reference numerals.

[0020] In Figure 1, reference numeral 20 denotes the vacuum circuit breaker, which comprises a pair of vacuum interrupters 16 arranged in a grounded tank 21, an insulating operating rod 5 for operating the opening and closing of each vacuum interrupter 16, and a link mechanism 22 between the vacuum interrupters 16.

[0021] Here, insulating gas (such as SF6 or dry air) is filled inside the grounded tank 21. As shown in Fig. 2, the upper end 5a of the insulating operating rod 5 is inserted into the conductor case 2 of the link mechanism 22 via the support case 30, and the link mechanism 22 opens and closes each vacuum interrupter 16 in response to the operation of the insulating operating rod 5.

[0022] Each vacuum interrupter 16 has a vacuum container consisting of an insulating tube and a metal flange (not shown), and is configured by housing a fixed electrode and a movable electrode within the vacuum container. One end of a fixed lead is fixed to this fixed electrode, while the other end of the fixed lead is supported by a grounded tank 21 (see FIG. 1) via a support 23.

[0023] One end of a movable lead 3 is fixed to the movable electrode, while the other end of the movable lead 3 extends from the end face of the vacuum vessel toward the link mechanism 22, and a connecting member 11 (see Figure 2) is attached to the other end. The connecting member 11 is disposed inside the conductive case 2 of the link mechanism 22, and a spring 4 is interposed between the connecting member 11 and the conductive case 2, and the movable lead 3 is biased by the spring 4.

[0024] <Configuration example of link mechanism 22> As shown in Figures 3 and 4, the link mechanism 22 comprises an aluminum conductor case 2 that forms an electrical path E (see Figure 1) between each vacuum interrupter 16, a pair of link portions 6 housed within the conductor case 2, and an axis portion 13 that rotatably connects each link portion 6 to a connecting member 11, and the conductor case 2 is formed in a box shape.

[0025] (1) Link section 6 Each link portion 6 includes a pair of links 6a, 6b that operate in response to the up and down movement of the insulating operating rod 5, as in the conventional example, and each link 6a, 6b is formed in a similar, approximately triangular shape.

[0026] As shown in Fig. 3, holes 7a-7b are formed in the links 6a, 6b, and holes 7a, 7c are elliptical. Here, as shown in Fig. 4, links 6a, 6b are rotatably connected to the upper end 5a of the insulating operating rod 5 via a shaft 8 inserted through hole 7a, rotatably supported between the side walls 2a of the conductor case 2 by a shaft 9 inserted through hole 7b, and rotatably connected to a connecting member 11 by a shaft 13 inserted through hole 7c. Cylindrical iron rolling members (rollers) 12 are attached to both ends of the shaft 13 (see Fig. 3).

[0027] (2) Conductor Case 2 5 to 7, the conductive case 2 has mounting holes 25 each having a horizontally elongated elliptical shape formed in the upper part of the side walls 2a facing each other in the front and rear, and a conductive cover 29 that closes the opening on the outside of the mounting holes 25 (the side of arrow P in FIG. 7 / outside the conductive case 2). Each mounting hole 25 is formed at a position corresponding to the conventional guide hole 10, but differs in that a frame-shaped guide member 26 is attached to the inner periphery of each mounting hole 25.

[0028] As shown in Figure 5, this guide member 26 has a frame portion 26c formed in a horizontally elongated ellipse similar to the mounting hole 25, a support portion 26b formed at the center position in the width direction (left-right direction / direction of arrows I and O) within the frame portion 26c, and guide holes 26a arranged on the left and right of the support portion 26b.

[0029] The rolling members 12 are housed and arranged in each guide hole 26a so that they can roll freely, and the guide members 26 are made of a material (such as iron) that is harder than the conductor case 2, taking into consideration friction with the rolling members 12. In this case, even if the material has high electrical resistance, no particular problem occurs because the conductor case 2 is the main current path.

[0030] 7, each mounting hole 25 has a recessed portion 25a formed around its inner periphery on the conductive cover 29 side (the outer side of the conductive case 2 / the side indicated by arrow P). On the other hand, the frame portion 26c has a protruding portion 26d formed around its outer periphery on the conductive cover 29 side, which fits into the recessed portion 25a.

[0031] Therefore, when the guide member 26 is attached to the mounting hole 25 from outside the conductive case 2, the two 25a and 26d fit together, preventing the guide member 26 from slipping out into the conductive case 2 (side Q in FIG. 7).

[0032] Conductor cover 29 is formed in a disk shape with an outer diameter larger than the inner diameter of mounting hole 25. Here, a mounting groove 2e for conductor cover 29 is formed around mounting hole 25 in side wall 2a, and after both 25a and 26d are fitted together, conductor cover 29 is fixed to the bottom of mounting groove 2e by means of bolts or the like. As a result, mounting hole 25 and each guide hole 26a are closed by conductor cover 29, and guide member 26 is pressed down and fixed within mounting hole 25.

[0033] In this case, if bolts or the like are used to secure guide member 26, the dimensions of conductor case 2 will increase, which could affect the voltage resistance performance and could also increase the number of work steps, making assembly workability worse.In contrast, with the configuration of Figure 7, since it is sufficient to hold both 25a and 26d together and then press them down with conductor cover 29, there is no need to increase the dimensions, assembly is simple, and workability is improved.

[0034] In addition, for applications requiring high voltage resistance, a dual-pressure structure is preferred in which the inside of the conductor case 2 (side Q in FIG. 7) is kept at a low pressure of approximately atmospheric pressure in consideration of the pressure applied to the bellows (not shown) of the vacuum interrupter 16, while the outside of the conductor case 2 is kept at a high pressure with high voltage resistance. In such cases, a dual-pressure structure can be achieved by fitting an O-ring 31 into groove 29a provided around the back surface of the conductor cover 29 to seal the gap between the conductor cover 29 and the mounting groove 2e, thereby ensuring airtightness.

[0035] <Example of operation> An example of the operation of the above configuration will be described below. First, in the closing operation, a lever connected to an operation mechanism (not shown) rotates in one direction in response to a closing command, and the insulating operating rod 5 is pushed up in the direction of arrow U in FIG.

[0036] As a result, the links 6a and 6b rotate in the direction of the arrow X in Fig. 4, and the movable lead 3 is pushed out in the direction of the arrow O in Fig. 3. Therefore, the movable electrode comes into contact with the fixed electrode, the circuit is closed, and electricity is passed in the direction of the arrow E in Fig. 1.

[0037] Next, in the breaking operation, the lever rotates in the other direction in response to a pull-out command, and the insulating operating rod 5 is pulled down in the direction of arrow D. This causes the links 6a and 6b to rotate in the direction of arrow Y, and the movable reed 3 is pulled in the direction of arrow I. Therefore, the two electrodes are separated, and the current in the direction of arrow E is broken.

[0038] During closing and opening operations of the circuit breaker 20, the rolling members 12 roll in the directions of arrows O and I on the inner circumferential surfaces of the guide holes 26a, ie, the inner surfaces of the frame portions 26c, in conjunction with the rotation of the links 6a and 6b.

[0039] In the conventional example, each rolling member 12 rolls on the inner periphery of a guide hole 10 formed in the side wall 2a of the conductive case 2 (see FIG. 8). In this case, the conductive case 2 forms the current path E, so a highly conductive material is used for the side wall 2a. Therefore, as mentioned above, the inner periphery of the guide hole 10 in the side wall 2a may wear out, which may affect the current-carrying performance.

[0040] In contrast, with the link mechanism 22, the rolling members 12 roll on the inner surface of the frame body 26c, which has a higher hardness than the conductive case 2, and wear on the side wall 2a of the conductive case 2 is prevented as in the past. This makes it possible to improve the wear resistance without impairing the current-carrying performance of the conductive case 2.

[0041] Particularly in the case of the high-voltage circuit breaker 20, there is a demand for wear resistance during high-speed operation, and this demand can be met with a simple structure without the need for surface treatment or other measures.

[0042] The present invention is not limited to the above-described embodiment, and can be modified and implemented within the scope of the claims. For example, the present invention can be configured as a double-break vacuum circuit breaker 20 equipped with a link mechanism 22. [Explanation of symbols]

[0043] 2...Conductor case 2a...Side wall 3... Movable lead 4...Spring 5...Insulated operating rod 5a...Top end 6...Link section 6a, 6b...Link 7a~7c…hole 8, 9, 13...Shaft 11...Connecting member 12...Rolling member 21...Ground tank 22...Link mechanism 25...Mounting hole 25a...Concave part 26...Guide member 26a...Guide hole 26b…Support pillar 26c…Frame part 26d…Convex portion 29...Conductor cover 31...O-ring

Claims

1. A link mechanism for a circuit breaker that opens and closes a pair of vacuum interrupters arranged in a grounded tank filled with insulating gas in response to operation of an insulating operating rod, a conductive case that forms a current path between the vacuum interrupters; a pair of links housed in the conductor case; a shaft portion that rotatably connects each of the links to each of the vacuum interrupters; rolling members provided on both ends of the shaft member; a pair of mounting holes formed opposite to each other in the conductive case; a guide member provided on the inner periphery of each mounting hole; Equipped with A link mechanism for a circuit breaker, characterized in that each of the rolling members is disposed in each of the guide members so as to be freely rollable.

2. Each of the guide members is It is formed in a frame shape, A pair of guide holes is provided. The rolling members are disposed in the guide holes, respectively.

2. The circuit breaker link mechanism according to claim 1.

3. A recess is formed on the inner periphery of the mounting hole, The guide member has a convex portion formed on its outer periphery that fits into the concave portion.

2. The circuit breaker link mechanism according to claim 1.

4. The recessed portion is formed on the inner peripheral edge of the outer side of the conductive case, The convex portion is formed on the outer peripheral edge of the conductive case.

4. The circuit breaker link mechanism according to claim 3.

5. A conductor cover is provided to close the mounting hole after the fitting.

5. The circuit breaker link mechanism according to claim 4.

6. 6. The link mechanism for a circuit breaker according to claim 5, further comprising a member for sealing between said conductor cover and said conductor case.

7. a grounded tank filled with insulating gas; a pair of vacuum interrupters disposed within the grounded tank; an insulating operating rod for operating the opening and closing of each vacuum interrupter; The link mechanism according to any one of claims 1 to 6, which opens and closes each of the vacuum interrupters in response to operation of the insulating operating rod; A vacuum circuit breaker comprising:

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