Switch

Abstract

The present invention provides a switch comprising: a fixed contact (24b); a movable contact (25b) that comes in contact with and separates from the fixed contact (24b) in association with a rotational travel of a rod-shaped movable contactor (22b); and a metal grid (26b) disposed so as to oppose the fixed contact (24b) in a second direction orthogonal to a first direction and along the longitudinal direction of the movable contactor (22b), the first direction being the movable direction of the movable contact (25b). The grid (26b) returns a gas flow flowing along the second direction from the movable contact (25b) and the fixed contact (24b) toward the grid (26b) to a periphery of the movable contact (25b) and the fixed contact (24b), the gas flow being generated between the movable contact (25b) and the fixed contact (24b) at the time of an opening operation in which the fixed contact (24b) separates from the movable contact (25b).

Description

switch

[0001] The present disclosure relates to a switch disposed between a power source and a load.

[0002] Conventionally, contact switches equipped with a grid, which is a metal member having three sides and surrounding the movable contact and the fixed contact from three directions, have been known. In contact switches equipped with a grid, an electromagnetic force acts on an arc that occurs between the movable contact and the fixed contact during an opening operation in which the movable contact separates from the fixed contact. The arc is drawn from between the movable contact and the fixed contact to the grid, where it is extended and broken. In this way, contact switches equipped with a grid can quickly break an arc that occurs during an opening operation.

[0003] Patent Document 1 discloses a contact switch in which left and right return side plates are arranged upright on the left and right sides inside a grid block. The contact switch disclosed in Patent Document 1 introduces the arc into the grid block through the inside of the left and right return side plates, and returns the hot gas flow generated between the movable contact and the fixed contact to the surroundings of the movable and fixed contacts by the left and right return side plates. The hot gas generated during the opening operation has a lower temperature than the arc and has an arc cooling effect, so returning the hot gas to the surroundings of the movable and fixed contacts can promote extinguishing of the arc.

[0004] Japanese Unexamined Patent Publication No. 56-036815

[0005] In the contact switch disclosed in Patent Document 1, the grid is formed from a plurality of plate-shaped members, so hot gas leaks through gaps between the plate-shaped members, reducing the effect of promoting arc extinguishing. For this reason, the contact switch disclosed in Patent Document 1 has room for further improvement in the ability to interrupt the arc that occurs during the contact opening operation.

[0006] The present disclosure has been made in view of the above, and has an object to provide a switch having high performance in interrupting an arc that occurs during a contact opening operation.

[0007] In order to solve the above-mentioned problems and achieve the object, a switch according to the present disclosure includes a fixed contact, a movable contact that is attached to a rod-shaped movable contactor that rotates and moves, and that comes into and separates from the fixed contact as the movable contactor rotates, and a metal grid that is arranged opposite the fixed contact in a second direction that is perpendicular to a first direction that is a moving direction of the movable contact and that follows the longitudinal direction of the movable contactor. The grid returns a gas flow that occurs between the movable contact and the fixed contact during an opening operation in which the fixed contact moves away from the movable contact, and that flows in the second direction from the movable contact and the fixed contact toward the grid, to the periphery of the movable contact and the fixed contact.

[0008] According to the present disclosure, it is possible to obtain an effect of obtaining a switch having high performance in interrupting an arc generated during a contact opening operation.

[0009] FIG. 1 is a top view of a switch according to embodiment 1; FIG. 2 is a diagram schematically showing a cross section of a switch according to embodiment 1; FIG. 3 is a diagram schematically showing a cross section of the internal structure of the second-phase arc-extinguishing chamber of a switch according to embodiment 1; FIG. 4 is a diagram showing a state in which an arc is generated between the movable contact and the fixed contact of a switch according to embodiment 1; FIG. 5 is a perspective view of the internal structure of the second-phase arc-extinguishing chamber of a switch according to embodiment 2; sectional view of the internal structure of the second-phase arc extinguishing chamber of a switchgear according to a second modified embodiment of embodiment 2; top view of the internal structure of the second-phase arc extinguishing chamber of a switchgear according to a second modified embodiment of embodiment 2; top view of the internal structure of the second-phase arc extinguishing chamber of a switchgear according to embodiment 3; top view of the internal structure of the second-phase arc extinguishing chamber of a switchgear according to embodiment 4;

[0010] Hereinafter, a switch according to an embodiment will be described in detail with reference to the drawings.

[0011] Embodiment 1. Fig. 1 is a top view of a switch according to embodiment 1. Fig. 2 is a diagram schematically illustrating a cross section of the switch according to embodiment 1. Fig. 2 is a diagram schematically illustrating a cross section of the switch 1 taken along line II-II in Fig. 1. As illustrated in Figs. 1 and 2, the Y direction, Z direction, and X direction are defined as directions perpendicular to one another. Specifically, the Z direction is a first direction in which a movable contact 25b and a fixed contact 24b (described later) come into contact with and separate from each other and which is the direction in which the movable contact 25b moves. The Y direction is a second direction perpendicular to the Z direction and extending along the longitudinal direction of a movable contactor 22b (described later). The X direction is a third direction perpendicular to the Z direction and Y direction and extending along the lateral direction of the movable contactor 22b (described later). Furthermore, the Z direction is a general term for the +Z direction and the −Z direction which are opposite directions to each other, the Y direction is a general term for the +Y direction and the −Y direction which are opposite directions to each other, and the X direction is a general term for the +X direction and the −X direction which are opposite directions to each other. Note that in the following description, an example is taken in which the +Z direction corresponds to the upward direction, the −Z direction corresponds to the downward direction, the +Y direction corresponds to the forward direction, the −Y direction corresponds to the backward direction, the +X direction corresponds to the leftward direction, and the −X direction corresponds to the rightward direction, but this example does not limit the orientation in which the switch 1 is installed.

[0012] The switch 1 is a contact switch configured for, for example, a three-phase power supply and has three arc-extinguishing chambers. Since the switch 1 has the same structure for each phase, the structure of only one phase will be described below, but the other phases also have similar structures and redundant description will be omitted.

[0013] As shown in Figures 1 and 2, the switchgear 1 includes a contact unit 1A having a first-phase arc extinguishing chamber 21a, a second-phase arc extinguishing chamber 21b, and a third-phase arc extinguishing chamber 21c adjacent to each other, a switching mechanism unit 1B that drives the contact unit 1A, and a relay unit 1C that activates the switching mechanism unit 1B when an overcurrent is detected.

[0014] The fixed contacts 23a, 23b, 23c are connected to one-phase wiring of a three-phase power supply (not shown) via power-supply-side terminals 231a, 231b, 231c, respectively, and the fixed terminals 23d, 23e, 23f are connected to load-side terminals 231d, 231e, 231f, respectively. The first-phase arc-extinguishing chamber 21a, the second-phase arc-extinguishing chamber 21b, and the third-phase arc-extinguishing chamber 21c have the same structure. Therefore, the following description will mainly focus on the structure of the second-phase arc-extinguishing chamber 21b, and will omit redundant description of the structures of the first-phase arc-extinguishing chamber 21a and the third-phase arc-extinguishing chamber 21c.

[0015] Fig. 3 is a top view of the internal structure of a second-phase arc-extinguishing chamber of the switchgear according to embodiment 1. Fig. 4 is a schematic cross-sectional view of the internal structure of the second-phase arc-extinguishing chamber of the switchgear according to embodiment 1. Fig. 4 shows a cross-sectional view of the internal structure of the second-phase arc-extinguishing chamber 21b taken along line IV-IV in Fig. 3. Note that Figs. 3 and 4 illustrate the positional relationship of the movable contactor 22b provided with the movable contact 25b, the fixed contactor 23b provided with the fixed contact 24b, the grid 26b provided near these, and the two insulating members 271b and 272b on the power supply side of one phase of a three-phase power supply. However, the same structure is also applicable to the power supply side of the other two phases, and therefore, redundant description will be omitted here.

[0016] The second phase arc extinguishing chamber 21b has a fixed contactor 23b provided with a fixed contactor 24b, a movable contactor 22b provided with a movable contactor 25b, a grid 26b provided near the fixed contactor 24b and the movable contactor 25b, and two insulating members 271b, 272b provided near the grid 26b.

[0017] The grid 26b is made of a magnetic material such as iron. When a fault current is detected, the movable contact 25b separates from the fixed contact 24b, generating hot gas flowing in the +Y direction from the movable contact 25b or the fixed contact 24b between the movable contact 25b and the fixed contact 24b along with an arc. The grid 26b forms a flow path that directs the hot gas flowing forward from the movable contact 25b or the fixed contact 24b in the ±X and −Y directions of the movable contact 25b or the fixed contact 24b. In other words, the grid 26b has the function of reversing the flow direction of the hot gas.

[0018] 3 and 4, the grid 26b is disposed on an extension of the movable contact 22b in the longitudinal direction and has multiple surfaces surrounding the fixed contact 24b. Specifically, as shown in FIG. 3, the grid 26b has two opposing side surfaces 261b and 262b that cover the fixed contact 24b and a connecting portion 263b that connects them, forming a U-shape when viewed from above. The side surfaces 261b and 262b sandwich the fixed contact 24b in the X direction, which is perpendicular to the Z direction, which is the direction in which the movable contact 22b moves. The connecting portion 263b faces the fixed contact 24b in the Y direction, which is perpendicular to the Z direction, which is the direction in which the movable contact 22b moves. The dimension of the connecting portion 263b in the Z direction, which is the direction in which the movable contact 22b moves, is greater than or equal to the dimension in the Y direction. As shown in FIGS. 3 and 4, when the movable contact 25b is positioned near the fixed contact 24b, the movable contact 25b, together with the fixed contact 24b, is covered by the two side surfaces 261b, 262b and the connecting portion 263b.

[0019] The two insulating members 271b, 272b are arranged between the fixed contact 24b and the grid 26b inside the grid 26b so as to expose at least a portion of the connecting portion 263b of the grid 26b when viewed from the fixed contact 24b. The inside of the grid 26b is the area surrounded on three sides by the connecting portion 263b and the two side portions 261b, 262b. It is not necessary to arrange both of the two insulating members 271b, 272b; it is sufficient if at least one of them is arranged.

[0020] When a fault current is detected, hot gas flows from movable contact 25b and fixed contact 24b in the +Y direction, but when it hits connecting portion 263b, it changes direction to the ±X direction, and then changes direction to the -Y direction along side portions 261b, 262b and insulating members 271b, 272b. Therefore, hot gas generated between movable contact 25b and fixed contact 24b is returned to the surroundings of movable contact 25b and fixed contact 24b by grid 26b.

[0021] The movable contact 22b is driven by the switching mechanism 1B and rotates around the drive shaft 221b shown in Fig. 4. Specifically, when energized, the switching mechanism 1B rotates the movable contact 22b around the drive shaft 221b until the movable contact 25b and the fixed contact 24b come into contact. When the relay unit 1C detects a fault current, it activates the switching mechanism 1B and rotates the movable contact 22b around the drive shaft 221b in a direction that moves the movable contact 25b away from the fixed contact 24b.

[0022] When an overcurrent is detected, the relay unit 1C activates the switching mechanism unit 1B, causing the movable contact 25b to separate from the fixed contact 24b, generating an arc between the movable contact 25b and the fixed contact 24b. A process for interrupting the arc generated between the movable contact 25b and the fixed contact 24b will be described. FIG. 5 illustrates a state in which an arc has occurred between the movable contact and the fixed contact of the switch according to the first embodiment. Immediately after the movable contact 25b separates from the fixed contact 24b, an arc connecting the movable contact 25b and the fixed contact 24b occurs at position A1. In addition to the grid 26b exerting an electromagnetic force on the arc in the +Y direction, the hot gas flow generated between the movable contact 25b and the fixed contact 24b in the +Y direction drives the arc, causing the arc to move between the insulating members 271b and 272b and be pulled by the connecting portion 263b of the grid 26b to position A2. When the arc attracted to the grid 26b comes into contact with the connecting portion 263b, a current flows through the grid 26b, and the arc moves to positions A3 and A4 and is broken. By breaking the arc, the interruption of the arc generated between the movable contact 25b and the fixed contact 24b is completed.

[0023] In the switchgear 1 according to the first embodiment, the arc generated between the movable contact 25b and the fixed contact 24b is driven in the +Y direction toward the grid 26b by the electromagnetic force. Furthermore, the switchgear 1 according to the first embodiment also drives the arc generated between the movable contact 25b and the fixed contact 24b in the +Y direction by the hot gas flow generated between the movable contact 25b and the fixed contact 24b. Furthermore, the switchgear 1 according to the first embodiment increases the driving force of the arc and improves the cooling effect of the arc by causing the hot gas flow, whose direction of travel has been changed at the connecting portion 263b, to flow in the -Y direction along the side portions 261b and 262b of the grid 26b. This allows the switchgear 1 according to the first embodiment to quickly extend and separate the arc toward the grid 26b, thereby completing the arc interruption more quickly.

[0024] 3 and 4 , the switch 1 according to the first embodiment includes a grid 26b having a dimension in the Z direction, which is the operating direction of the movable contact 22b, that is equal to or greater than the dimension in the Y direction, which is the arrangement direction of the fixed contact 24b and the connecting portion 263b, and having three or more surfaces. This increases the volume of the magnetic material and strengthens the electromagnetic force acting on the arc. Therefore, the switch 1 according to the first embodiment can quickly extend and break the arc, thereby completing arc interruption quickly. Furthermore, the switch 1 according to the first embodiment has insulating members 271b and 272b located inside the grid 26b. This allows the arc to move to the connecting portion 263b, at least a portion of which is exposed, without the arc coming into contact with the side portions 261b and 262b of the grid 26b, thereby reliably completing arc interruption.

[0025] Embodiment 2. Figure 6 is a perspective view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to embodiment 2. Figure 7 is a top view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to embodiment 2. The switchgear 1 according to embodiment 2 differs from the switchgear 1 according to embodiment 1 in that a gap 91 is formed between each of the insulating members 271b, 272b and the grid 26b. In the switchgear 1 according to embodiment 2, a return path X1 is formed between the insulating members 271b, 272b, a return path X2 is formed between the side surface portion 261b and the insulating member 271b by the gap 91, and a return path X3 is formed between the side surface portion 262b and the insulating member 272b by the gap 91.

[0026] When the contacts are opened, part of the hot gas generated along with the arc between the movable contact 25b and the fixed contact 24b flows from the movable contact 25b and the fixed contact 24b toward the grid 26b in the +Y direction. The hot gas that collides with the connecting portion 263b branches in the ±X directions perpendicular to the Z direction, which is the moving direction of the movable contactor 22b. The hot gas flows along the inner surface of the grid 26b through the return paths X2 and X3 in the -Y direction, opposite to the hot gas in the return path X1.

[0027] Because gaps 91 are formed between each of insulating members 271b, 272b and grid 26b, the distance between insulating members 271b, 272b is narrower than in switchgear 1 according to embodiment 1. As a result, the flow of hot gas flowing in the +Y direction through return path X1 formed between insulating members 271b, 272b is stronger than in switchgear 1 according to embodiment 1. Furthermore, because return paths X2, X3 are formed between insulating members 271b, 272b and side surface portions 261b, 262b, the flow of hot gas flowing in the −Y direction along side surface portions 261b, 262b and insulating members 271b, 272b is stronger than in switchgear 1 according to embodiment 1. Furthermore, because return path X1 and return paths X2, X3 are separated by insulating members 271b, 272b, the hot gas flowing in the +Y direction and the hot gas flowing in the −Y direction do not interfere with each other and weaken each other.

[0028] FIG. 8 is a top view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to a first modification of Embodiment 2. FIG. 9 is a cross-sectional view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to a first modification of Embodiment 2. FIG. 9 shows a cross-section of the internal structure of a second-phase arc extinguishing chamber 21b taken along line IX-IX in FIG. 8. In the switchgear 1 according to the first modification of Embodiment 2, the insulating members 271b, 272b have lower portions 31b, 32b that face the side portions 261b, 262b and are lower than the side portions 261b, 262b. The distance between the lower portions 31b, 32b and the fixed contact 24b in the first direction is shorter than the distance between the end of the side portions 261b, 262b in the first direction and the fixed contact 24b. In the switchgear 1 according to the first modification of Embodiment 2, the space above the lower portions 31b, 32b forms a gap 91, forming return paths X2, X3.

[0029] Fig. 10 is a top view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to a second modified example of embodiment 2. Fig. 11 is a cross-sectional view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to a second modified example of embodiment 2. Fig. 11 shows a cross-section of the second-phase arc extinguishing chamber 21b taken along line XI-XI in Fig. 10. In switchgear 1 according to the second modified example of embodiment 2, grooves 33b and 34b extending in the Y direction are formed in insulating members 271b and 272b, respectively. In switchgear 1 according to the second modified example of embodiment 2, the internal spaces of grooves 33b and 34b form gaps 91, forming return paths X2 and X3.

[0030] In this way, the return paths X2 and X3 may be formed by at least a portion of either the side surface 261b or the side surface 262b of the grid 26b and the insulating member 271b or the insulating member 272b, and may be separated from the return path X1.

[0031] The switchgear 1 according to the second embodiment includes a return path X1 through which the hot gas flow generated between the movable contact 25 b and the fixed contact 24 b flows in the +Y direction, and return paths X2 and X3 through which the hot gas flow redirected by the connecting portion 263 b flows in the −Y direction, thereby strengthening the hot gas flow generated between the movable contact 25 b and the fixed contact 24 b and the hot gas flow returned around the movable contact 25 b and the fixed contact 24 b and preventing them from weakening each other. Therefore, the switchgear 1 according to the second embodiment has the same effects as the switchgear 1 according to the first embodiment, and furthermore, the switchgear 1 can quickly extend and divide the arc to the grid 26 b, thereby completing the arc interruption more quickly.

[0032] The hot gas does not necessarily have to branch in the ±X direction at the connecting portion 263b. Therefore, the same effect can be obtained by flowing the hot gas through at least one of the return flow paths X2 and X3.

[0033] Embodiment 3. Fig. 12 is a top view of the internal structure of the second-phase arc-extinguishing chamber of a switchgear according to embodiment 3. The switchgear 1 according to embodiment 3 differs from the switchgear 1 according to embodiment 2 in that the insulating members 271b, 272b are arranged such that wall surfaces 291b, 292b of the insulating members 271b, 272b that face the fixed contact 24b are inclined with respect to the side surfaces 261b, 262b of the grid 26b.

[0034] 12 , in the switch 1 according to the third embodiment, the insulating member 271b is disposed so that the wall surface 291b and the side surface 261b form an angle θ in the XY plane, and similarly, the insulating member 272b is disposed so that the wall surface 292b and the side surface 262b form an angle θ' in the XY plane. Here, the angle θ and the angle θ' do not necessarily have to be the same size.

[0035] As in the switch 1 according to the modified example of the second embodiment, the insulating members 271b and 272b may have lower portions 31b and 32b.

[0036] In the switchgear 1 according to the third embodiment, wall surfaces 291b, 292b of the insulating members 271b, 272b that face the fixed contact 24b are inclined with respect to the side surfaces 261b, 262b of the grid 26b, and the closer the insulating members 271b, 272b are to the movable contact 25b and the fixed contact 24b in the Y direction, the faster the flow rate of the hot gas flowing through the return path X1. Therefore, in the switchgear 1 according to the third embodiment, the force that the hot gas flow exerts on the arc increases, causing the arc to be quickly stretched to the grid 26b and broken, thereby completing the arc interruption more quickly.

[0037] Embodiment 4. Figure 13 is a top view of the internal structure of a second-phase arc extinguishing chamber of a switchgear according to embodiment 4. In the switchgear 1 according to embodiment 4, insulating members 271b, 272b are installed so that the area of ​​the gas outlet surfaces a of the return paths X2, X3 is smaller than the area of ​​the gas inlet surface b from the return path X1 to the return paths X2, X3. Here, the areas of the gas outlet surfaces a and the gas inlet surfaces b of the return paths X2, X3 do not necessarily have to be the same, as long as the relationship of area of ​​gas outlet surface a < area of ​​gas inlet surface b is satisfied in each of the return paths X2, X3.

[0038] FIG. 14 is a perspective view of the internal structure of a second-phase arc-extinguishing chamber of a switchgear according to a modification of the fourth embodiment. The grid 26b is not shown in FIG. 14 . The insulating member 271b of the switchgear 1 according to the modification of the fourth embodiment, like the insulating member 271b of the switchgear 1 according to the second modification of the second embodiment, has a groove 33b extending in the first direction formed in the insulating member 271b, with the inside of the groove 33b forming a gap 91 to form the return path X2. In the switchgear 1 according to the modification of the fourth embodiment, the cross-sectional area of ​​the groove 33b increases toward the connecting portion 263b. Although not shown in FIG. 14 , like the insulating member 272b of the switchgear 1 according to the second modification of the second embodiment, the insulating member 272b has a groove 34b similar to the groove 33b of the insulating member 271b, with the inside of the groove 34b forming a gap 91 to form the return path X3. Therefore, in the switch 1 according to the modified example of embodiment 4, the area of ​​the gas outflow surface a from the return paths X2 and X3 is smaller than the area of ​​the gas inflow surface b from the return path X1 to the return paths X2 and X3.

[0039] Similarly to the switchgear 1 according to the first modification of the second embodiment, the insulating members 271b, 272b may have the lower portions 31b, 32b. In the case where the insulating members 271b, 272b have the lower portions 31b, 32b, the heights of the lower portions 31b, 32b decrease toward the connecting portion 263b along the Y direction, thereby enabling a structure in which the area of ​​the gas outlet surfaces a of the reflux channels X2, X3 is smaller than the area of ​​the gas inlet surfaces b from the reflux channels X1 to the reflux channels X2, X3. Alternatively, the height difference between the side surfaces 261b, 262b of the grid 26b and the lower portions 31b, 32b of the insulating members 271b, 272b increases toward the connecting portion 263b along the Y direction, thereby enabling a structure in which the area of ​​the gas outlet surfaces a of the reflux channels X2, X3 is smaller than the area of ​​the gas inlet surfaces b from the reflux channels X1 to the reflux channels X2, X3. In addition, the X-direction dimensions of the return channels X2 and X3 may be increased as they approach the connecting portion 263b along the Y direction, so that the area of ​​the gas outlet surface a of the return channels X2 and X3 is smaller than the area of ​​the gas inlet surface b from the return channel X1 to the return channels X2 and X3.

[0040] In the switchgear 1 according to the fourth embodiment, the area of ​​the gas outflow surface a of the return paths X2, X3 is smaller than the area of ​​the gas inflow surface b, and the return paths X2, X3 are narrowed in the flow direction, so that the flow rate of the gas blown onto the movable contact 25 b and the fixed contact 24 b can be increased. Therefore, the switchgear 1 according to the fourth embodiment can further enhance the arc cooling effect compared to the switchgears 1 according to the first to third embodiments, and can more reliably complete the interruption of the arc.

[0041] Embodiment 5. Figure 15 is a top view of the internal structure of the second-phase arc extinguishing chamber of a switchgear according to embodiment 5. The switchgear 1 according to embodiment 5 differs from the switchgear 1 according to embodiment 4 in that it includes gas blowing members 281b, 282b. The gas blowing members 281b, 282b are installed adjacent to the ends of the side portions 261b, 262b opposite the side connected to the connecting portion 263b. The surfaces of the gas blowing members 281b, 282b facing the fixed contact 24b are curved so that the surfaces approach the fixed contact 24b as they move away from the connecting portion 263b.

[0042] By providing the gas blowing members 281b and 282b on the gas outflow surface a side of the return paths X2 and X3, a return path X4 is formed in the space sandwiched between the insulating member 271b and the gas blowing member 281b, and a return path X5 is formed in the space sandwiched between the insulating member 272b and the gas blowing member 282b.

[0043] When the contacts are opened, a portion of the hot gas generated along with the arc between the movable contact 25b and the fixed contact 24b flows from the movable contact 25b or the fixed contact 24b toward the grid 26b. The hot gas that collides with the connecting portion 263b branches into ±X directions perpendicular to the Z direction, which is the moving direction of the movable contactor 22b. The hot gas flows along the inner surface of the grid 26b through the return paths X2 and X3 in the -Y direction, opposite to the hot gas flow in the return path X1. The hot gas that has flowed through the return paths X2 and X3 has its direction of travel diverted by the gas blowing members 281b and 282b, and the hot gas flows through the return paths X4 and X5 in the direction toward the movable contact 25b and the fixed contact 24b, respectively, and is blown onto the movable contact 25b and the fixed contact 24b.

[0044] The switch 1 according to the fifth embodiment can efficiently spray hot gas onto the movable contact 25b and the fixed contact 24b, thereby enhancing the arc cooling effect and more reliably completing the interruption of the arc.

[0045] Sixth Embodiment A switch 1 according to a sixth embodiment differs from the switch 1 according to the second embodiment in that the structure of the grid 26b is different. Fig. 16 is a perspective view of the grid of the switch 1 according to the sixth embodiment. In the switch 1 according to the sixth embodiment, at least one through-hole 264b is provided in at least one of the side portions 261b, 262b of the grid 26b, and the space inside and the space outside the grid 26b are connected via the through-hole 264b. The switch 1 according to the sixth embodiment is otherwise the same as the switch 1 according to the second embodiment.

[0046] By providing at least one through-hole 264b in at least one of the side surface portions 261b, 262b, part of the hot gas flowing through the reflux paths X2, X3 is discharged to the outside of the reflux paths X2, X3 through the through-hole 264b.

[0047] If the flow of hot gas in the reflux paths X2 and X3 is stagnant, the inflow of hot gas from the reflux path X1 will also be stagnant, weakening the arc drive caused by the hot gas flowing in the +Y direction through the reflux path X1. Furthermore, stagnant gas flow from the reflux path X1 to the reflux paths X2 and X3 will reduce the gas flow circulating around the fixed contact 24b and the movable contact 25b. The switchgear 1 according to the sixth embodiment can appropriately exhaust the hot gas flowing through the reflux paths X2 and X3 to the outside of the reflux paths X2 and X3, allowing the hot gas to circulate around the movable contact 25b and the fixed contact 24b without stagnating in the reflux paths X2 and X3. Therefore, in addition to the effects of the circuit breaker 1 according to embodiments 1 to 5, the circuit breaker 1 according to embodiment 6 can increase the reflux efficiency, which represents the proportion of hot gas generated between the movable contact 25b and the fixed contact 24b that circulates around the movable contact 25b and the fixed contact 24b, thereby more reliably completing the interruption of the arc.

[0048] Seventh Embodiment The switchgear 1 according to the seventh embodiment differs from the switchgear 1 according to the third embodiment in that the structure of the grid 26b is different. Fig. 17 is a perspective view of the internal structure of the second-phase arc-extinguishing chamber of the switchgear 1 according to the seventh embodiment. In the switchgear 1 according to the seventh embodiment, a plurality of grids 26b are stacked in the direction of movement of the movable contactor 22b. The grids 26b in each layer are not electrically connected to each other. Otherwise, the internal structure is the same as that of the second-phase arc-extinguishing chamber 21b of the switchgear 1 according to the fifth embodiment.

[0049] As in the first embodiment, the arc generated between the movable contact 25b and the fixed contact 24b is pulled by the stacked grids 26b, and connects the movable contact 25b and the fixed contact 24b via the connecting portion 263b of one of the grids 26b. After that, the grids 26b are electrically connected, and the arc is divided by the grids 26b, with the movable contactor 22b and the fixed contactor 23b at both ends.

[0050] In the switch 1 according to embodiment 7, if an arc is drawn into one of the plurality of grids 26b, the drawn arc can be interrupted by the plurality of grids 26b, thereby increasing the arc voltage and more reliably completing the arc interruption.

[0051] In addition, in the first to seventh embodiments, a contact switch having one pair of contacts per phase has been described, but the same can be implemented for a contact switch having multiple pairs of contacts per phase, and the scope of use is not limited thereto.

[0052] The configurations shown in the above embodiments are merely examples of the content, and may be combined with other known technologies, or parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0053] 1 Switch, 1A Contact portion, 1B Switching mechanism portion, 1C Relay portion, 21a First phase arc extinguishing chamber, 21b Second phase arc extinguishing chamber, 21c Third phase arc extinguishing chamber, 22b Movable contact, 23a, 23b, 23c Fixed contact, 23d, 23e, 23f Fixed terminal, 24b Fixed contact, 25b Movable contact, 26b Grid, 31b, 32b Lower portion, 33b, 34b Groove, 91 Gap, 221b Drive shaft, 231a, 231b, 231c Power supply side terminal, 231d, 231e, 231f Load side terminal, 261b, 262b Side portion, 263b Connecting portion, 264b Through hole, 271b, 272b Insulating member, 281b, 282b Gas blowing member, 291b, 292b wall surface.

Claims

1. A fixed contact, a movable contact installed on a rotatably moving rod-shaped movable contact element, the movable contact making contact with and separating from the fixed contact as the movable contact element rotates and moves, a metal grid disposed opposite the fixed contact in a second direction along the longitudinal direction of the movable contact element, the second direction being perpendicular to a first direction which is the moving direction of the movable contact, and at least one insulating member installed between the grid and the fixed contact, wherein the grid has two side portions facing each other with the movable contact therebetween in a third direction which is perpendicular to each of the first direction and the second direction, the insulating member is installed between at least one of the two side portions and the fixed contact, and the grid returns a gas flow flowing from the movable contact and the fixed contact toward the grid along the second direction, which is generated between the movable contact and the fixed contact during an opening operation in which the fixed contact moves away from the movable contact, to the periphery of the movable contact and the fixed contact. A switch characterized by this.

2. The grid has a connecting portion that faces the fixed contact in the second direction and connects the two side portions to each other, the insulating member exposes at least a part of the connecting portion of the grid as viewed from the position of the fixed contact, and the switch according to claim 1, wherein the connecting portion has a dimension in the first direction that is equal to or greater than the dimension in the second direction.

3. The switch according to claim 2, wherein a gap is formed between the insulating member and the side portion facing the insulating member.

4. A reflux path through which the gas flow flows in a direction opposite to the direction from the fixed contact toward the connecting portion in the second direction is formed by the gap, and the cross-sectional area of the gap at the end closer to the connecting portion in the second direction is larger than the cross-sectional area at the end farther from the connecting portion. The switch according to claim 3, characterized by this.

5. The insulating member has a lower portion which is a part where the distance from the fixed contact in the first direction is shorter than the distance between the end of the side portion in the first direction of the opposing side portion and the fixed contact, and the gap is formed above the lower portion. The switch according to claim 3, characterized by this.

6. The height difference, which is the distance between the bottom part and the end face of the insulating member in the first direction, increases as it approaches the connecting part along the second direction. The switch according to claim 5, characterized in that.

7. The dimension of the insulating member in the first direction at the bottom part increases as it approaches the connecting part along the second direction. The switch according to claim 5, characterized in that.

8. The insulating member has a groove extending in the second direction formed on the surface facing the side surface part, and the space inside the groove forms the gap. The switch according to claim 3, characterized in that.

9. The dimension of the gap in the first direction increases as it approaches the connecting part along the second direction. The switch according to claim 8, characterized in that.

10. The insulating member is installed such that the wall surface facing the fixed contact approaches the fixed contact in the third direction as it approaches the connecting part along the second direction. The switch according to claim 2, characterized in that.

11. The grid includes a gas spraying member that deflects the traveling direction of the gas flow flowing along the side surface part and sprays it onto the fixed contact. The switch according to claim 2, characterized in that.

12. The grid has a through hole formed in the side surface part that communicates the space surrounded by the connecting part and the side surface part with the outside of the space. The switch according to claim 2, characterized in that.

13. The switch according to any one of claims 1 to 12, characterized in that a plurality of the grids are stacked and arranged along the first direction.