Switch

Abstract

To provide a switch which suppresses lowering of insulation property caused by damage of a narrow slit.SOLUTION: A switch 11 includes a fixed contact 12, a movable contact 13, and an arc-extinguishing chamber 14. The fixed contact 12 is connected to a primary-side connection terminal 16. The movable contact 13 is connected to a secondary-side connection terminal 18, and is brought into contact with and separated from the fixed contact 12 by rotation. The arc-extinguishing chamber 14 stores the fixed contact 12, and extinguishes arc in current interruption by a narrow slit 51 in a width direction. The arc-extinguishing chamber 14 includes a storage part 52, and a gas retention part 55. The storage part 52 is expanded in a width direction more than the narrow slit 51 and stores the fixed contact 12. The gas retention part 55 is provided in the front of the storage part 52 in a depth direction, is expanded in the width direction more than the narrow slit 51 and retains arc gas in current interruption.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a switch. [Background technology]

[0002] Patent document 1 shows the structure of a switch that makes and breaks a circuit by bringing a movable electrode into contact with and separating it from a fixed electrode, and the arc extinguishing chamber is formed by a narrow gap through which the plate-shaped movable electrode can move forward and backward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6163431 Summary of the Invention [Problem to be solved by the invention]

[0004] Arc gases remain in the narrow gaps of the arc extinguishing chamber during interruption, which can cause contamination and a decrease in insulation. An object of the present invention is to suppress deterioration of insulation properties in a switch due to contamination of a narrow gap. [Means for solving the problem]

[0005] A switch according to one aspect of the present invention includes a fixed contact, a movable contact, and an arc-extinguishing chamber. The fixed contact is connected to a connection terminal on the primary side. The movable contact is connected to a connection terminal on the secondary side, and rotates to come into contact with and separate from the fixed contact. The arc-extinguishing chamber houses the fixed contact, and extinguishes an arc during interruption by a narrow gap in the width direction. The arc-extinguishing chamber includes a housing section and a gas retention section. The housing section is wider in the width direction than the narrow gap to house the fixed contact. The gas retention section is provided in front of the housing section in the depth direction, and wider in the width direction than the narrow gap to retain arc gas during interruption. Effect of the Invention

[0006] According to the present invention, by providing a gas retention portion that actively retains the arc gas, it is possible to prevent the arc gas from being retained in the gap of the arc extinguishing chamber, and therefore it is possible to prevent a decrease in insulation caused by contamination of the gap. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 13 is a diagram showing a fixed contact and a movable contact during closing. [Figure 9] 13A and 13B are diagrams showing the fixed contact and the movable contact when the closing operation is completed. [Figure 10] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that each drawing is a schematic view and may differ from the actual one. In addition, the following embodiment illustrates an apparatus and method for embodying the technical idea of ​​the present invention, and does not specify the configuration as described below. In other words, the technical idea of ​​the present invention can be modified in various ways within the technical scope described in the claims.

[0009] <<Embodiment>> "composition" In the following description, the three mutually orthogonal directions will be referred to as a width direction, a depth direction, and a top-bottom direction for the sake of convenience. FIG. 1 is a diagram showing a switch 11 in an interrupted state. Here, the switch 11 is shown as seen from one side in the width direction, from the front side in the depth direction, and from above in the up-down direction. The switch 11 is a load break switch (LBS) with a current-limiting fuse used to open and close high-voltage equipment and electric circuits such as transformers and capacitors, and is equipped with a fixed contact 12, a movable contact 13, and an arc-extinguishing chamber 14 for each pole.

[0010] The fixed contact 12 is not shown in the figure because it is accommodated in an arc-extinguishing chamber 14, but is connected to a connection terminal 16 on the primary side, which is the power source side. The movable contact 13 is connected to a secondary connection terminal 18, which is the load side, via a current-limiting fuse 17, and rotates to come into contact with and separate from the fixed contact 12. When the handle 21 of the switch 11 is operated to rotate the operating shaft 22, the three-pole movable contact 13 rotates in conjunction with the operating shaft 22 via the operating rod 23. The arc-extinguishing chamber 14 accommodates the fixed contact 12 and extinguishes the arc when it is interrupted by a narrow gap in the width direction. FIG. 2 is a diagram showing the switch 11 in the closed state. Here, the switch 11 is shown as viewed from one side in the width direction, from the front side in the depth direction, and from above in the up-down direction.

[0011] FIG. 3 is a diagram showing the fixed contact 12. As shown in FIG. Here, the fixed contact 12 is shown as viewed from one side in the width direction, from the front side in the depth direction, and from above in the up-down direction. The fixed contact 12 includes a main fixed contact 26 and a pair of auxiliary fixed contacts 27. The main fixed contact 26 is made of a conductive metal and is formed by bending a single sheet of plate material. When viewed from the top-bottom direction, the main fixed contact 26 is roughly U-shaped with an open end toward the front in the depth direction, and both ends are bent back in the depth direction by U-shape to form a pair of spring pieces facing each other in the width direction. The gap between the spring pieces is smaller than the plate thickness of the movable contact 13. The connection terminal 16 is a plate-like shape that extends in the top-bottom direction and is aligned in the width direction and top-bottom direction. The base end side of the main fixed contact 26 is fixed to the connection terminal 16.

[0012] The auxiliary fixed contacts 27 are made of a conductive metal, and each is formed by bending a single sheet of plate material. The inner side of the auxiliary fixed contacts 27 in the width direction is bent toward the front in the depth direction to form a pair of spring pieces facing each other in the width direction. The gap between the spring pieces is smaller than the plate thickness of the movable contactor 13. The pair of auxiliary fixed contacts 27 have their base ends fixed to a single connecting plate 28. The connecting plate 28 is a plate extending in the width direction and the up-down direction, and is formed in a substantially U-shape when viewed in the depth direction. The connection terminal 16 and the connection plate 28 protrude in the other width direction above the main fixed contact 26 and the auxiliary fixed contact 27, and a cylindrical resistor 29 is connected to their tips. The resistor 29 has a large resistance value of, for example, about 300 Ω, and suppresses magnetizing inrush current.

[0013] FIG. 4 is a diagram showing the movable contact 13 and the arc-extinguishing chamber 14. As shown in FIG. Here, the movable contact 13 and the arc extinguishing chamber 14 are shown as viewed from one side in the width direction, from the front side in the depth direction, and from above in the up-down direction. The movable contactor 13 is plate-like along the depth direction and the up-down direction, and is formed in a substantially V-shape when viewed in the width direction. A boss hole 31 is formed at the base end of the movable contactor 13, and a connecting hole 32 is formed at a position radially outwardly away from the boss hole 31. The boss hole 31 penetrates in the width direction, and a rotation shaft (not shown) is inserted therethrough. The connecting hole 32 penetrates in the width direction, and the operating rod 23 is connected thereto. The movable contactor 13 is pushed and pulled by the operating rod 23, so that it rotates about the boss hole 31. The arc-extinguishing chamber 14 is made of insulating resin, and includes a case 36 and a case 37 that are divided in the width direction. The resistor 29 is disposed outside the arc-extinguishing chamber 14.

[0014] FIG. 5 is a diagram showing case 36 and case 37. FIG. 1A shows the case 36 as viewed from the other side in the width direction, the front side in the depth direction, and the top in the up-down direction. An opposing surface 41 is formed on the inner peripheral surface of the case 36 at the front side in the depth direction, which is slightly outward in the width direction from a mating surface 38 with the case 37. The mating surface 38 is an end surface facing inward in the width direction, and is formed along the edges of the upper and lower sides of the case 36. The opposing surface 41 is a flat surface along the depth direction and the up-down direction. On the inner peripheral surface of the case 36, a concave surface 42 is formed at the back in the depth direction, which is concave toward the outside in the width direction than the opposing surface 41. The opposing surface 41 has a recess 43 formed at the back in the depth direction, which is concave toward the outside in the width direction. The recess 43 has a uniform depth in the width direction, and is formed in a rectangle with the vertical direction as the longitudinal direction when viewed from the width direction.

[0015] FIG. 1B shows the case 37 as viewed from one side in the width direction, the front side in the depth direction, and the top in the up-down direction. An opposing surface 44 is formed on the inner peripheral surface of the case 37 at the front side in the depth direction, which is slightly outward in the width direction from the mating surface 38 with the case 36. The mating surface 38 is an end surface facing inward in the width direction, and is formed along the edges of the upper and lower sides of the case 37. The opposing surface 44 is a flat surface along the depth direction and the up-down direction. On the inner peripheral surface of the case 37, a concave surface 45 is formed at the back in the depth direction, which is concave toward the outside in the width direction than the opposing surface 44. The opposing surface 44 has a recess 46 formed at the back in the depth direction, which is concave toward the outside in the width direction. The recess 46 has a uniform depth in the width direction, and is formed in a rectangle with the vertical direction as the longitudinal direction when viewed from the width direction.

[0016] FIG. 6 is a diagram showing the arc-extinguishing chamber 14. As shown in FIG. Here, a cross section of the arc extinguishing chamber 14 along the width and depth directions is shown as viewed from above in the vertical direction. The cases 36 and 37 are fitted together with their inner circumferential surfaces facing each other, and their mating surfaces 38 are in contact with each other. At the front of the arc extinguishing chamber 14 in the depth direction, a narrow gap 51 is formed by the opposing surfaces 41 and 44. The width dimension of the narrow gap 51 is slightly larger than the plate thickness of the movable contactor 13. The front of the narrow gap 51 in the depth direction and most of the lower part in the vertical direction are open to allow the tip side of the rotating movable contactor 13 to enter and exit.

[0017] At the back in the depth direction of the arc-extinguishing chamber 14, an accommodation section 52 is formed by the concave surfaces 42 and 45. The connecting plate 28 is fitted and supported in a concave groove formed in the concave surfaces 42 and 45. In the accommodation section 52, the area behind the connecting plate 28 becomes a main accommodation section 53 in which the main fixed contact 26 is accommodated, and the area in front of the connecting plate 28 becomes an auxiliary accommodation section 54 in which the auxiliary fixed contact 27 is accommodated. A gas retention portion 55 is formed by the recesses 43 and 46 at a position of the narrow gap 51 in the arc extinguishing chamber 14 close to the auxiliary storage portion 54. The gas retention portion 55 retains the arc gas during interruption.

[0018] FIG. 7 is a diagram showing the arc-extinguishing chamber 14 and the movable contact 13. As shown in FIG. Here, the arc extinguishing chamber 14 with the case 36 removed and the movable contactor 13 are shown as viewed from one side in the width direction. When the movable contactor 13 rotates from the breaking position to the closing position, the tip side of the movable contactor 13 first enters the narrow gap 51, then enters the auxiliary housing portion 54 and contacts the auxiliary fixed contactor 27, and finally enters the main housing portion 53 and contacts the main fixed contactor 26, thereby entering the closing state. When the movable contactor 13 rotates from the closing position to the breaking position, the process is reversed. That is, the tip side of the movable contactor 13 first moves away from the main fixed contactor 26 and exits the main housing portion 53, then moves away from the auxiliary fixed contactor 27 and exits the auxiliary housing portion 54, and finally exits the narrow gap 51, thereby entering the breaking state.

[0019] Next, suppression of magnetizing inrush current will be described. FIG. 8 is a diagram showing the fixed contact 12 and the movable contact 13 during closing. Here, the fixed contact 12 and the movable contact 13 are shown as viewed from one side in the width direction, from the front in the depth direction, and from above in the up-down direction during closing. When the tip of the movable contact 13 comes into contact with the auxiliary fixed contact 27, it is not in contact with the main fixed contact 26, so it is connected to the connection terminal 16 via the connection plate 28 and resistor 29 and is in a conducting state. As shown by the thick solid arrow, the current flows through the connection terminal 16, resistor 29, connection plate 28, and auxiliary fixed contact 27 in that order, and then to the movable contact 13. At this time, the magnetizing inrush current is suppressed by passing through the resistor 29.

[0020] FIG. 9 is a diagram showing the fixed contact 12 and the movable contact 13 when the closing is completed. Here, the fixed contact 12 and the movable contact 13 after the switch is fully closed are shown as viewed from one side in the width direction, from the front in the depth direction, and from above in the up-down direction. When the movable contact 13 rotates to the closed position, it comes into contact with both the auxiliary fixed contact 27 and the main fixed contact 26, but since the resistance value of resistor 29 is large, the main fixed contact 26, which has a smaller resistance value, becomes a bypass. As shown by the thick solid arrow, the current flows through the connection terminal 16 and the main fixed contact 26 to the movable contact 13, and a normal current-carrying state is achieved.

[0021] <Action and Effect> Next, main effects of the embodiment will be described. The switch 11 includes a fixed contact 12, a movable contact 13, and an arc extinguishing chamber 14. The fixed contact 12 is connected to a connection terminal 16 on the primary side. The movable contact 13 is connected to a connection terminal 18 on the secondary side, and is brought into contact with and separated from the fixed contact 12 by rotating. The arc extinguishing chamber 14 accommodates the fixed contact 12, and extinguishes the arc at the time of breaking by a narrow gap 51 in the width direction. The arc extinguishing chamber 14 includes a housing section 52 and a gas retention section 55. The housing section 52 is enlarged in the width direction from the narrow gap 51 to accommodate the fixed contact 12. The gas retention section 55 is provided in front of the housing section 52 in the depth direction, and is enlarged in the width direction from the narrow gap 51 to retain the arc gas at the time of breaking. In this way, by providing the gas retention section 55 that actively retains the arc gas, it is possible to suppress retention of the arc gas in the narrow gap 51 of the arc extinguishing chamber 14. Therefore, deterioration of the insulation caused by contamination of the narrow gap 51 can be suppressed.

[0022] The fixed contact 12 includes a main fixed contact 26 and an auxiliary fixed contact 27, and the main fixed contact 26 is connected to the primary connection terminal 16. The auxiliary fixed contact 27 is provided in front of the main fixed contact 26 in the depth direction and is connected to the primary connection terminal 16 via a resistor 29 for suppressing inrush current. The main fixed contact 26 is accommodated in the accommodation section 52 at the back in the depth direction, and the auxiliary fixed contact 27 is accommodated in front of the main fixed contact 26 in the depth direction. As a result, when the movable contact 13 is closed, it first comes into contact with the auxiliary fixed contact 27 and then comes into contact with the main fixed contact 26. At this time, when the movable contact 13 comes into contact with the auxiliary fixed contact 27, a current flows via the resistor 29, thereby suppressing the excitation inrush current. Gas retention portion 55 is formed with its longitudinal direction in the vertical direction. Since the arc gas rises, by providing gas retention portion 55 with its longitudinal direction in the vertical direction, the arc gas can be effectively retained.

[0023] Next, a comparative example will be described. Here, a comparative example will be described in which the gas retention section 55 is omitted. Since the other configurations are the same as those in the above-described embodiment, the same reference numerals are used for the common configurations, and detailed description thereof will be omitted. FIG. 10 is a diagram showing a comparative example. The arc gas during interruption contains soot and metal particles. Therefore, if the arc gas during interruption remains in the narrow gap 51 of the arc-extinguishing chamber 61, the soot and metal particles may adhere to the narrow gap 51, and the insulation may be deteriorated due to such contamination.

[0024] <<Variation>> In the embodiment, a configuration has been described in which the recess 43 is provided in the case 36 and the recess 46 is provided in the case 37, but the present invention is not limited to this. That is, a recess may be provided in at least one of the case 36 and the case 37. In the embodiment, the recesses 43 and 46 are described as having a uniform depth in the width direction, but the present invention is not limited to this. Since the arc gas has a tendency to rise, the upper part in the vertical direction may have a deeper depth toward the outside in the width direction than the lower part. This allows the arc gas to be retained more effectively.

[0025] Although the above description has been given with reference to a limited number of embodiments, the scope of the invention is not limited thereto, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art. [Explanation of symbols]

[0026] 11...switch, 12...fixed contact, 13...movable contact, 14...arc-extinguishing chamber, 16...connecting terminal, 17...current-limiting fuse, 18...connecting terminal, 21...handle, 22...operating shaft, 23...operating rod, 26...main fixed contact, 27...auxiliary fixed contact, 28...connecting plate, 29...resistance, 31...boss hole, 32...coupling hole, 36...case, 37...case, 38...mating surface, 41...opposing surface, 42...concave surface, 43...recess, 44...opposing surface, 45...concave surface, 46...recess, 51...slit, 52...accommodating section, 53...main accommodation section, 54...auxiliary accommodation section, 55...gas retention section, 61...arc-extinguishing chamber

Claims

1. A fixed contact connected to a primary connection terminal; a movable contact connected to a secondary connection terminal and adapted to come into contact with and separate from the fixed contact by rotating; an arc-extinguishing chamber that accommodates the fixed contact and extinguishes the arc during interruption by a narrow gap in the width direction; The arc extinguishing chamber is a receiving portion that is wider in a width direction than the narrow gap and receives the fixed contact; a gas retention portion that is provided depthwise before the accommodation portion and is expanded in widthwise beyond the narrow gap to retain arc gas during breaking.

2. The fixed contact is A main fixed contact connected to the connection terminal on the primary side; an auxiliary fixed contact provided in front of the main fixed contact in a depth direction and connected to the primary side connection terminal via a resistor for suppressing an inrush current; 2. The switch according to claim 1, wherein the housing portion houses the main fixed contact at a rear portion in a depth direction and the auxiliary fixed contact at a front portion in the depth direction.

3. The switch according to claim 1, wherein the gas retention portion is formed with its longitudinal direction extending in the up-down direction.

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