Terminal structure of switching device

Abstract

To suppress an increase in heat generation even when used with a high-frequency AC power supply in a switchgear terminal structure.SOLUTION: A switchgear terminal structure includes a terminal plate 13 configured by laminating a plurality of conductors 31.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a terminal structure for a switching device. [Background technology]

[0002] An example of a switching device that opens and closes a circuit is a vacuum circuit breaker as shown in Patent Document 1. In such a switching device, a terminal board drawn out to the outside is made up of a single conductor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-38843 Summary of the Invention [Problem to be solved by the invention]

[0004] Switchgear is generally used with AC power frequencies of 50 Hz or 60 Hz, but special applications may require use at higher frequencies, such as 1 kHz or higher. However, as the frequency increases, the current flowing through the conductor becomes concentrated on the surface due to the skin effect, so when used at high frequencies, electrical resistance increases and heat generation increases. An object of the present invention is to suppress an increase in heat generation in a terminal structure of a switching device even when used with a high-frequency AC power source. [Means for solving the problem]

[0005] A terminal structure for a switching device according to one aspect of the present invention includes a terminal plate configured by laminating a plurality of conductors. [Effects of the Invention]

[0006] According to the present invention, since the terminal board is constructed by laminating a plurality of conductors, an increase in heat generation can be suppressed even when used with a high-frequency AC power supply. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram showing a vacuum electromagnetic contactor. [Figure 2] 1A and 1B are diagrams illustrating a terminal board according to a first embodiment. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] 10A and 10B are diagrams illustrating a terminal board according to a second embodiment. [Figure 6] 10A and 10B are diagrams illustrating a terminal board according to a third embodiment. [Figure 7] FIG. 10 is a diagram showing a terminal board according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the following embodiments exemplify devices and methods for embodying the technical concept of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical concept of the present invention can be modified in various ways within the technical scope described in the claims.

[0009] First Embodiment "composition" In the following description, the three mutually orthogonal directions will be referred to as the up-down direction, the width direction, and the front-rear direction for the sake of convenience. FIG. 1 is a diagram showing a vacuum electromagnetic contactor. Here, the view from one side in the width direction is shown. The vacuum electromagnetic contactor 11, an example of a switching device, switches the AC main circuit and is intended for special use in high-frequency AC power supplies with frequencies of 1 kHz or higher. The vacuum electromagnetic contactor 11 comprises a vacuum valve 12, a pair of terminal boards 13, an operating rod 14, and an operating mechanism 15. The phases of the RST are aligned in the width direction. The vacuum electromagnetic contactor 11 may be of either a fixed or drawer type, and the opening and closing operation may be maintained by either a normally energized type or a latch type.

[0010] The vacuum valve 12 is a generally cylindrical member that extends vertically, has a vacuum inside, and includes a fixed rod 21 and a movable rod 22. The fixed rod 21 is an axial member that extends vertically, with its upper portion protruding from the vacuum valve 12 and its lower portion located inside the vacuum valve 12, and a disk-shaped fixed contact 23 formed at its lower end. The movable rod 22 is an axial member that extends vertically, is held so as to be able to move back and forth vertically, its lower portion protruding from the vacuum valve 12 and its upper portion located inside the vacuum valve 12, and a disk-shaped movable contact 24 formed at its upper end that faces the fixed contact 23. Therefore, when the movable rod 22 descends, the movable contact 24 separates from the fixed contact 23, and when the movable rod 22 ascends, the movable contact 24 comes into contact with the fixed contact 23.

[0011] The pair of terminal plates 13 are generally plate-shaped along the front-rear and width directions, and are provided vertically side by side on the primary and secondary sides at the rear of the vacuum electromagnetic contactor 11. The primary-side terminal plate 13 is connected to the upper end of the fixed rod 21 with fastening bolts 25, and the secondary-side terminal plate 13 is connected to the lower part of the movable rod 22 via a flexible conductor 26. The flexible conductor 26 allows the movable rod 22 to move up and down while maintaining the electrical connection between the movable rod 22 and the secondary-side terminal plate 13. The pair of terminal plates 13 are connected to the primary-side main circuit and the secondary-side main circuit as main circuit terminals. The operating rod 14 extends in the vertical direction, and its upper end is connected to the lower end of the movable rod 22 in an insulated state. The operating mechanism 15 drives the operating rod 14 in the up and down direction by electromagnetic operation or manual operation.

[0012] FIG. 2 is a diagram showing the terminal board of the first embodiment, and shows all or some of the terminal boards 13 used in the vacuum electromagnetic contactor 11. In FIG. (a) in the figure shows the terminal board 13 as viewed from above and below, and (b) in the figure shows the terminal board 13 as viewed from the width direction. The terminal board 13 has a width dimension W of approximately 30 mm and a vertical dimension, i.e., a thickness t, of approximately 6 mm. The terminal board 13 is configured by stacking multiple (here, for example, four) conductors 31 of uniform thickness in the thickness direction of the terminal board 13, and the thicknesses of the conductors 31 may be the same or different. Each conductor 31 is a metal with high electrical conductivity, and is preferably copper or aluminum, which are inexpensive and lightweight. Each conductor 31 is joined by screwing, riveting, caulking, brazing, soldering, welding, etc. It is preferable that there are multiple joining points. FIG. 3 shows an example of joining. Here, as an example, the conductors 31 are joined by screws 32. The fastening bolts 25 also serve to join the conductors 31, and it is desirable to join them at two or more points in this way.

[0013] Each conductor 31 is insulated from the other conductors by an insulating coating on the entire or partial outer surface. For example, the insulating coating is made of a resin such as epoxy (EP), silicone (SI), phenol (PF), polyester (PE), polyurethane (PU), polybutylene terephthalate (PBT), polyamide (PA), polycarbonate (PC), unsaturated polyester (UP), polyacetal (POM), polyethylene (PET), polyvinyl chloride (PVC), acrylonitrile (ABS), polyphenylene sulfide (PPS), polyphenylene ether (PPE), polyamide-imide (PAI), polytetrafluoroethylene (PTEF), perfluoroalkoxyalkane (PFA), perfluoroethylene propene copolymer (FEP), or ethylene tetrafluoroethylene copolymer (ETFE). The insulating coating is not limited to resin, and may be replaced by a high-resistance metal film or the like. Note that the insulating coating is omitted from the electrical connection portions (not shown) of the vacuum electromagnetic contactor 11 and the circular holes (not shown) for connecting the main circuit. Furthermore, for corrosion prevention and reduction of connection resistance, the wire may be plated with platinum, gold, silver, copper, zinc, cadmium, tin, nickel, chromium, or the like. The terminal plate 13 is plated with platinum, gold, silver, copper, zinc, cadmium, tin, nickel, chromium, etc. for corrosion prevention and connection resistance reduction. The insulating coating may be omitted for the surface to be plated.

[0014] 《Effect》 Next, the main functions of the first embodiment will be described. The terminal structure of the switchgear includes a terminal plate 13 configured by stacking a plurality of conductors 31. Because the terminal plate 13 is configured by stacking a plurality of conductors 31 in this way, an increase in heat generation can be suppressed even when used with a high-frequency AC power source. That is, as the frequency increases, the current flowing through the conductors is concentrated on the surface side due to the skin effect, increasing the electrical resistance, but because the terminal plate 13 is divided into a plurality of conductors 31, the increase in electrical resistance can be suppressed. Terminal board 13 is constructed by laminating insulatingly coated conductors 31. This prevents conductors 31 from being integrated together and terminal board 13 from becoming a single conductor. Therefore, even when used with a high-frequency AC power supply, an increase in heat generation can be reliably suppressed.

[0015] The terminal board 13 has conductors 31 stacked in the thickness direction, which makes it easy to stack and join the conductors 31, and can suppress an increase in manufacturing costs. The conductor 31 is made of copper or aluminum, which ensures high electrical conductivity, is inexpensive, and keeps the weight down. The surface of terminal plate 13 is plated, which can prevent corrosion of terminal plate 13 and an increase in connection resistance. The terminal structure of a switching device is used in special applications where the frequency of the AC power supply is 1 kHz or higher. Therefore, a measure against the skin effect, in which a plurality of conductors 31 are laminated to form the terminal board 13, is effective.

[0016] Next, a comparative example will be described. FIG. 4 is a diagram showing a comparative example. Here, terminal board 36 is used instead of terminal board 13 described above. (a) in the figure shows terminal board 36 as viewed from above and below, and (b) in the figure shows terminal board 36 as viewed from the width direction. Terminal board 36 has a typical structure used when the AC power frequency is 50 Hz or 60 Hz, and is composed of a single conductor 37. Therefore, as the frequency increases, the current flowing through conductor 37 becomes more concentrated on the surface side due to the skin effect. Therefore, when used at high frequencies, such as 1 kHz or higher, for special applications, there is a problem that the electrical resistance increases and the amount of heat generated increases.

[0017] <<Variation>> In the first embodiment, the configuration in which each conductor 31 is insulated is described, but the present invention is not limited to this. That is, the surfaces of the conductors 31 may have work-hardened layers, oxide films, adsorbed substances, dirt, etc., which may cause minute resistance even when the conductors 31 are in contact, and this may provide the same function as an insulating coating. Therefore, the insulating coating of each conductor 31 may be omitted in some cases. In the first embodiment, the terminal strip 13 is formed by stacking a plurality of conductors 31 in each phase of a three-phase circuit section and on both the primary and secondary sides, but this is not limited to this. That is, the terminal strip 13 may be formed by stacking a plurality of conductors 31 in at least one phase of a three-phase, single-phase, or single-pole circuit section and on at least one of the primary and secondary sides. In the first embodiment, the terminal structure of the vacuum electromagnetic contactor 11 has been described, but the present invention is not limited to this and may be applied to the terminal structure of a vacuum circuit breaker or a load break switch. In short, the present invention may be applied to any other device as long as it is a terminal board for a switching device that opens and closes an electric circuit.

[0018] Second Embodiment "composition" The second embodiment shows another form of stacking of terminal boards, and is similar to the first embodiment except that the aforementioned terminal board 13 is replaced with a new terminal board 41, and detailed explanations of the common parts will be omitted. FIG. 5 is a diagram showing a terminal board according to the second embodiment. (a) in the figure shows terminal board 41 as viewed from above and below, and (b) in the figure shows terminal board 41 as viewed from the width direction. Terminal board 41 is configured by stacking multiple (here, for example, nine) conductors 42 in the width direction of terminal board 41. Other aspects are the same as terminal board 13 described above.

[0019] 《Effect》 Next, the main functions of the second embodiment will be described. In terminal board 41, conductors 42 are stacked in the width direction. In this way, stacking multiple conductors 42 in the width direction can achieve the same effect as terminal board 13 described above. That is, because terminal board 41 is divided into multiple conductors 42, an increase in electrical resistance can be suppressed even when used with a high-frequency AC power supply, and an increase in heat generation can be suppressed. Because terminal board 41 has a width dimension W greater than its thickness t, it is easy to increase the number of divisions in the width direction. Therefore, it is easier to divide it into smaller pieces than terminal board 13, which is stacked in the thickness direction, and therefore an increase in heat generation can be suppressed even when used with a high-frequency AC power supply. Other functions and effects are the same as those of the first embodiment described above.

[0020] Third Embodiment "composition" The third embodiment shows another form of stacking of terminal boards, and is similar to the first embodiment except that the aforementioned terminal board 13 is replaced with a new terminal board 46, and detailed explanations of the common parts will be omitted. FIG. 6 is a diagram showing a terminal board according to the third embodiment. (a) in the figure shows the terminal board 46 as viewed from above and below, (b) in the figure shows the terminal board 46 as viewed from the width direction, and (c) in the figure shows the terminal board 46 as viewed from the front and back direction. The terminal board 46 is constructed by stacking a plurality of rod-shaped or wire-shaped conductors 47 in both the thickness direction and the width direction of the terminal board 46. In this case, for example, there are four conductors in the thickness direction and nine conductors in the width direction, for a total of 36 conductors. In this case, since it is difficult to join them using fasteners such as screws, rivets, or caulking, they are joined by brazing, soldering, welding, or the like. In other respects, it is the same as the terminal board 13 described above.

[0021] 《Effect》 Next, the main operation of the third embodiment will be described. In terminal board 46, conductors 47 are laminated in both the thickness direction and the width direction. In this way, even when multiple conductors 47 are laminated in the thickness direction and the width direction, the same effect as that of terminal board 13 described above can be obtained. That is, because terminal board 46 is divided into multiple conductors 47, an increase in electrical resistance can be suppressed even when used with a high-frequency AC power supply, and an increase in heat generation can be suppressed. Furthermore, because terminal board 46 can be divided into more small pieces than terminal board 13, which is laminated only in the thickness direction, or terminal board 41, which is laminated only in the width direction, an increase in heat generation can be suppressed even when used with a high-frequency AC power supply. Other functions and effects are the same as those of the first embodiment described above.

[0022] Fourth Embodiment "composition" The fourth embodiment shows another form of insulation for each conductor, and is similar to the first embodiment except that the aforementioned terminal board 13 is replaced with a new terminal board 51, and detailed explanations of the common parts will be omitted. FIG. 7 is a diagram showing a terminal board according to the fourth embodiment. (a) in the figure shows the terminal board 51 as viewed from above and below, and (b) in the figure shows the terminal board 51 as viewed from the width direction. The terminal board 51 has multiple (here, for example, four) conductors 52 stacked in the thickness direction of the terminal board 51, and an insulator 53 is interposed between each conductor 52, thereby eliminating the need for a resin coating on each conductor 52. Any resin used for resin coating can be used for the insulator 53. The rest is the same as the terminal board 13 described above.

[0023] 《Effect》 Next, the main operation of the fourth embodiment will be described. Terminal plate 51 is configured with insulators 53 interposed between conductors 52. In this way, even if insulators 53 are interposed between conductors 52 instead of insulating each conductor 52, the same effect as that of terminal plate 13 described above can be obtained. In other words, it is possible to prevent conductors 52 from becoming integrated and terminal plate 51 from becoming a single conductor. Therefore, even when used with a high-frequency AC power source, an increase in heat generation can be reliably prevented. Other functions and effects are the same as those of the first embodiment described above.

[0024] Although the present invention has been described above 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]

[0025] 11...vacuum electromagnetic contactor, 12...vacuum valve, 13...terminal board, 14...operating rod, 15...operating mechanism, 21...fixed rod, 22...movable rod, 23...fixed contact, 24...movable contact, 25...fastening bolt, 26...flexible conductor, 31...conductor, 36...terminal board, 37...conductor, 41...terminal board, 42...conductor, 46...terminal board, 47...conductor, 51...terminal board, 52...conductor, 53...insulator

Claims

1. A terminal board is provided which is formed by stacking a plurality of plate-shaped conductors in the thickness direction, The terminal structure for a switching device is characterized in that the terminal plate is constructed by laminating the conductors that are insulated.

2. A terminal board is provided which is formed by stacking a plurality of plate-shaped conductors in the thickness direction, 10. A terminal structure for a switching device, wherein the terminal plate is configured by interposing an insulator between the conductors.

3. 3. The terminal structure for a switching device according to claim 1, wherein the conductor is made of copper or aluminum.

4. 4. The terminal structure for a switching device according to claim 1, wherein the surface of the terminal plate is plated.

5. 5. The terminal structure of a switching device according to claim 1, wherein the terminal structure is used at a high frequency where the frequency of the AC power supply is 1 kHz or more.

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