switch

Abstract

To reduce the operating load when closing a switch. [Solution] The fixed contact 12 is composed of a pair of elastic pieces 61 that face each other with a gap d between them. The movable contact 13 is a plate that is inserted into the gap d. The fixed contact 12 is formed in a stepped manner so that the movable contact 13 first spreads apart only one of the elastic pieces 61, and then spreads apart the other elastic piece 61.

Description

[Technical Field]

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

[0002] Patent Document 1 shows the structure of a switch that closes a circuit by bringing a movable contact into contact with a fixed contact. The fixed contact is composed of a pair of elastic pieces that face each other with a gap between them, and a plate-shaped movable contact is inserted into the gap. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6454571 Summary of the Invention [Problem to be solved by the invention]

[0004] In a configuration in which the two elastic pieces are simultaneously pushed apart when inserting the movable contact into the gap of the fixed contact, the operating load at the time of closing becomes large. An object of the present invention is to reduce the operating load when closing a switch. [Means for solving the problem]

[0005] A switch according to one aspect of the present invention includes a fixed contact and a movable contact. The fixed contact is composed of a pair of elastic pieces facing each other with a gap therebetween. The movable contact is a plate-like piece that is inserted into the gap. The fixed contacts are formed in a stepped manner so that the movable contact first spreads apart one of the elastic pieces and then spreads apart the other elastic piece. [Effects of the Invention]

[0006] According to the present invention, when the movable contact is inserted into the gap of the fixed contact, the two elastic pieces are pushed apart one by one in turn, so that the operating load at the time of closing can be reduced. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 2 is a diagram showing a movable contact and an arc-extinguishing chamber. [Figure 4] FIG. [Figure 5] FIG. 2 is a diagram showing a fixed contact and a movable contact. [Figure 6] FIG. [Figure 7] 10A and 10B are diagrams illustrating the operation of the movable contact when the switch is closed. [Figure 8] FIG. 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 the following. 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] <<Embodiment>> "composition" In the following description, the three mutually orthogonal directions will be referred to as the width direction, depth direction, and up-down direction for the sake of convenience. FIG. 1 is a diagram showing the switch 11 in an interrupted state. Here, the switch 11 is shown as seen from one side in the width direction, from the front in the depth direction, and from above in the vertical 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 drawing because it is housed in an arc extinguishing chamber 14, but is connected to a primary side connection terminal 16 on the power supply side. The movable contact 13 is connected to a secondary connection terminal 18 on 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 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 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 the other side in the width direction, the front side in the depth direction, and from above in the up-down direction. The movable contactor 13 is plate-shaped 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 through the boss hole 31. The connecting hole 32 also penetrates in the width direction, and is connected to the operating rod 23. The movable contactor 13 is pushed and pulled by the operating rod 23, causing it to rotate around 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 separated in the width direction. The case 36 and the case 37 are fastened together with bolts and nuts.

[0012] FIG. 4 is a diagram showing the arc-extinguishing chamber 14. As shown in FIG. This figure shows a cross section of the arc extinguishing chamber 14 along the width and depth directions, 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. A narrow gap 51 is formed by the opposing surfaces 41 and 44 at the front of the arc extinguishing chamber 14 in the depth direction. The width dimension of the narrow gap 51 is slightly larger than the thickness of the movable contactor 13. The front of the narrow gap 51 in the depth direction and a large portion of the lower portion in the vertical direction are open to allow the tip end of the rotating movable contactor 13 to move forward and backward. A housing portion 52 is formed by the recessed surfaces 42 and 45 at the back of the arc extinguishing chamber 14 in the depth direction. The connection terminal 16 is a plate-like member extending vertically and aligned along the width and vertical directions. The base end of the fixed contactor 12 is fixed to the connection terminal 16 by the housing portion 52.

[0013] FIG. 5 is a diagram showing the fixed contact 12 and the movable contact 13. As shown in FIG. Here, the case 37 has been removed to expose the slit 51 and the accommodating portion 52, and the fixed contact 12 and the movable contact 13 are shown as viewed from the other width direction. When the movable contact 13 rotates from the open position to the closed position, the tip of the movable contact 13 first enters the slit 51, then enters the accommodating portion 52 and comes into contact with the fixed contact 12, thereby achieving the closed state. When the movable contact 13 rotates from the closed position to the open position, the process is reversed. That is, the tip of the movable contact 13 first moves away from the fixed contact 12 and retracts from the accommodating portion 52, and finally retracts from the slit 51, thereby achieving the open state.

[0014] FIG. 6 is a diagram showing the fixed contact 12. As shown in FIG. (a) in the figure shows the fixed contact 12 as viewed from the other side in the width direction, the front side in the depth direction, and from above in the vertical direction. (b) in the figure shows the fixed contact 12 as viewed from the front side in the depth direction. (c) in the figure shows the fixed contact 12 as viewed from above in the vertical direction. (d) in the figure shows the fixed contact 12 as viewed from the other side in the width direction. The fixed contact 12 is made of conductive metal and is formed by bending a single plate material. When viewed from the vertical direction, the fixed contact 12 has a roughly U-shape that opens toward the front side in the depth direction, and the tip sides of both ends are bent back in the depth direction by U-shape to form a pair of elastic pieces 61 facing each other in the width direction. When no external force is applied, the gap d between the elastic pieces 61 is smaller than the thickness t of the movable contact 13. When viewed from the width direction, the tips of the pair of elastic pieces 61 of the fixed contact 12 are non-parallel, and the tips of the pair of elastic pieces 61 are inclined by an angle θ with respect to a reference line L1 extending in the vertical direction, and are symmetrical with respect to an axis L2 perpendicular to the reference line L1.

[0015] FIG. 7 is a diagram showing the operation of the movable contact 13 when the switch is closed. (a) in the figure shows the movable contactor 13 in the middle of closing, as seen from the other side in the width direction. The movable contactor 13 first contacts only one of the elastic pieces 61, pushing only that elastic piece 61 outward in the width direction. Therefore, the movable contactor 13 is formed so that when only one of the elastic pieces 61 is pushed outward, its tip does not contact the other elastic piece 61 as seen from the width direction. (b) in the figure shows the movable contactor 13 after closing is complete, as seen from the other side in the width direction. The movable contactor 13 then contacts the other elastic piece 61, pushing the other elastic piece 61 outward in the width direction. In this way, the movable contactor 13 is formed in a stepped manner so that it first pushes out only one of the elastic pieces 61, and then pushes out the other elastic piece 61.

[0016] Since the gap d between the pair of elastic pieces 61 is smaller than the thickness t of the movable contact 13, the amount of deflection δ in the width direction of each elastic piece 61 when the movable contact 13 is inserted is expressed by the following formula. δ=(td) / 2 Therefore, the dimensions and shapes of the elastic piece 61 and the movable contact 13 are set so that only one of the elastic pieces 61 is pushed outward in the width direction by a deflection amount δ before the movable contact 13 comes into contact with the other elastic piece 61. During the insertion process, the manner in which the movable contactor 13 and the elastic piece 61 make contact changes. That is, first, the corners at the tip of the movable contactor 13 come into contact with the curved surface of the elastic piece 61 and begin to spread the elastic piece 61 apart. At this time, the elastic piece 61 makes contact at an angle to the moving direction of the movable contactor 13 when viewed from above and below, so the insertion resistance increases. Then, after the elastic piece 61 has been spread apart to the deflection amount δ, the flat surface of the movable contactor 13 comes into contact with the flat surface of the elastic piece 61. At this time, the elastic piece 61 makes contact parallel to the moving direction of the movable contactor 13, so the insertion resistance decreases. Therefore, by first spreading apart only one elastic piece 61 and then spreading apart the other elastic piece 61, the operating load is reduced compared to spreading apart both elastic pieces 61 simultaneously.

[0017] <<Action and Effect>> Next, the main effects of the embodiment will be described. The switch 11 includes a fixed contact 12 and a movable contact 13. The fixed contact 12 is composed of a pair of elastic pieces 61 facing each other with a gap d between them. The movable contact 13 is plate-shaped and inserted into the gap d. The fixed contact 12 is formed in a stepped manner so that the movable contact 13 first spreads apart one of the elastic pieces 61 and then spreads apart the other elastic piece 61. As a result, when the movable contact 13 is inserted into the gap d of the fixed contact 12, the two elastic pieces 61 are spread apart one by one, thereby reducing the operating load when closing the switch.

[0018] When viewed from the side, the tips of the pair of elastic pieces 61 of the fixed contact 12 are not parallel to each other. This allows the two elastic pieces 61 to be pushed apart one by one when the movable contact 13 is inserted into the gap d of the fixed contact 12. The movable contactor 13 is formed so that when only one of the elastic pieces 61 is pushed apart, the tip thereof does not come into contact with the other elastic piece 61 as viewed from the side. This allows the two elastic pieces 61 to be pushed apart one by one in turn when the movable contactor 13 is inserted into the gap d of the fixed contactor 12. When viewed from the side, the fixed contact 12 has a shape in which the tips of the pair of elastic pieces 61 are inclined with respect to a reference line L1 extending in the vertical direction and are symmetrical with respect to an axis L2 perpendicular to the reference line L1. This improves the manufacturability of the fixed contact 12.

[0019] Next, a comparative example will be described. Here, a comparative example will be described in which the tip of the fixed contact 71 is not stepped. 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 will be omitted. FIG. 8 is a diagram showing a comparative example. (a) in the figure shows the fixed contact 71 as seen from the other side in the width direction, the front side in the depth direction, and from above in the up-down direction. (b) in the figure shows the movable contact 13 as seen from the other side in the width direction during closing. When viewed from the width direction, the tips of the pair of elastic pieces 72 of the fixed contact 71 are parallel, and are also positioned at the same position in the depth direction. Therefore, when inserting the movable contact 13 into the gap of the fixed contact 71, the two elastic pieces 72 are pushed apart at the same time, which increases the operating load when closing.

[0020] <<Variation>> In the embodiment, the configuration in which the tips of the pair of elastic pieces 61 are inclined at an angle θ with respect to the reference line L1 has been described, but the present invention is not limited to this. That is, as long as one elastic piece 61 and the other elastic piece 61 are unequal in level when viewed in the width direction, the tips of the pair of elastic pieces 61 may be parallel to the reference line L1. In the embodiment, a configuration in which a resistor for suppressing magnetizing inrush current is not provided has been described, but the present invention is not limited to this. If a resistor for suppressing magnetizing inrush current is provided, a main fixed contact and an auxiliary fixed contact are provided. Therefore, the present invention may be applied to both the main fixed contact and the auxiliary fixed contact.

[0021] 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]

[0022] 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, 31...boss hole, 32...coupling hole, 36...case, 37...case, 38...mating surface, 41...opposing surface, 42...concave surface, 44...opposing surface, 45...concave surface, 51...slit, 52...accommodating portion, 61...elastic piece, 71...fixed contact, 72...elastic piece

Claims

1. a fixed contact formed by a pair of elastic pieces facing each other with a gap therebetween; a plate-shaped movable contactor inserted into the gap, A switch characterized in that the fixed contacts are formed in a stepped manner so that the movable contact first spreads apart only one of the elastic pieces and then spreads apart the other elastic piece.

2. 2. The switch according to claim 1, wherein tips of the pair of elastic pieces of the fixed contact are not parallel to each other when viewed from the side.

3. 3. The switch according to claim 2, wherein the movable contact is formed so that when only one of the elastic pieces is pushed apart, the tip end does not come into contact with the other elastic piece when viewed from the side.

4. The switch according to claim 2, characterized in that when viewed from the side, the tips of the pair of elastic pieces of the fixed contact are inclined with respect to a reference line extending in the vertical direction and are shaped to be linearly symmetrical with respect to an axis perpendicular to the reference line.

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