Contact point switch

Abstract

A contact point switch (1) comprises: a fixed contact (2b) that has a fixed contact point (22b) on the upper surface; a movable contact (3b) that has a movable contact point (31b) being in contact with the fixed contact point (22b) on the lower surface; a grid (11b) that is formed from a magnetic body, that faces the movable contact (3b) in the longitudinal direction of the movable contact (3b) at the time of contact point opening between the fixed contact point (22b) and the movable contact point (31b), and that is formed above the upper surface of the movable contact (3b) and below the contact surface of the movable contact (31b) with respect to the fixed contact point (22b); a case cover (9) that is positioned on the outer side of the fixed contact (2b), the movable contact (3b), and the grid (11b); and an insulator (121b) that is positioned on a side surface of the movable contact (3b) and that forms, in a gap with respect to the case cover (9), a circulation path which allows flowing therethrough of a gas generated at the time of the contact point opening.

Description

Contact switch

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

[0002] In conventional contact switches, a metal grid is placed above the movable contacts, facing them. This allows an electromagnetic force to act on the arc that occurs between the movable and fixed contacts when the contacts are opened, attracting the arc from above the contacts to the grid, stretching it, and breaking it. In this way, the arc that occurs when the contacts are opened can be quickly interrupted.

[0003] Furthermore, conventional contact switches are provided with a grid block made of an insulating material that supports the grid, and a block with a sidewall spacing wider than the width of the grid block. This allows the arc to pass through the inside of the grid block and be introduced into the grid, and hot gas generated between the contacts is returned from the side of the grid through a return passage formed by the grid block and the block with a wider width to the contacts, thereby improving the arc interruption performance (see, for example, Patent Document 1).

[0004] Japanese Utility Model Application Publication No. 56-101854

[0005] When the contacts are opened, the arc generates an electromagnetic force that attracts the arc from above the contacts to the grid, stretching it and moving it to the grid. Hot gas is generated when the arc occurs, but by controlling the flow path of the hot gas, the hot gas acts as a driving force to attract the arc from above the contacts to the grid, stretching it and making it easier for it to move to the grid. The hot gas is much cooler than the arc and has an arc-cooling effect, so by returning the hot gas to the arc generation point, it is possible to promote the extinguishing of the arc between the contacts.

[0006] However, in the contact switch of Patent Document 1, the direction of the electromagnetic force generated by the arc differs from the direction of the arc driving force caused by hot gas flow path control, so the arc may not move and may remain between the contacts. In other words, in conventional contact switches, the arc may not move to the grid, so there is room for improvement in the performance of interrupting the arc that occurs when the contacts open.

[0007] The present disclosure has been made in view of the above, and has an object to provide a contact switch that can improve the performance of interrupting an arc that occurs when the contacts are opened.

[0008] In order to solve the above-mentioned problems and achieve the object, the contact switch of the present disclosure comprises a fixed contactor having a fixed contact on its upper surface, a movable contactor having a movable contact on its lower surface that contacts the fixed contact, a grid formed from a magnetic material that faces the movable contactor in the longitudinal direction of the movable contactor when the fixed contact and the movable contact are in contact with each other, and that is formed above the upper surface of the movable contactor and below the contact surface of the movable contact with the fixed contact, a case cover located outside the fixed contactor, the movable contactor, and the grid, and an insulator located on the side of the movable contactor that forms a return path through which gas generated when the contact is in contact with the case cover flows in the gap between the movable contactor and the case cover.

[0009] The contact switch according to the present disclosure has the effect of improving the performance of interrupting an arc that occurs when the contacts are opened.

[0010] FIG. 1 is a schematic configuration diagram of a contact switch according to embodiment 1; FIG. 2 is a schematic configuration diagram of a contact switch according to embodiment 1; FIG. 3 is a schematic configuration diagram of a contact switch according to embodiment 1; FIG. 4 is a perspective view of a contact switch according to embodiment 1; FIG. 5 is a cross-sectional view of a contact switch according to embodiment 1; FIG. 6 is a diagram showing a schematic configuration of a contact switch according to embodiment 1; FIG. 7 is a diagram showing a schematic configuration of a contact switch according to embodiment 1; 1 is a cross-sectional view showing a schematic cross-sectional structure of a contact portion of a contact switch according to embodiment 4;

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A contact switch according to an embodiment will be described in detail below with reference to the drawings.

[0012] Embodiment 1. FIG. 1 is a schematic diagram of a contact switch 1 according to embodiment 1. FIG. 2 is a cross-sectional view schematically illustrating the cross-sectional structure of the contact switch 1 according to embodiment 1. FIG. 2 is a cross-sectional view schematically illustrating the cross-sectional structure taken along line II-II in FIG. 1 . As shown in FIGS. 1 and 2 , the up-down direction, the front-rear direction, and the left-right direction are defined as directions perpendicular to each other. The up-down direction is the direction in which the movable contact and the fixed contact, which will be described later, come into contact or are not in contact with each other, and is the moving direction of the movable contact. The front-rear direction is a transverse direction that crosses the up-down direction and is a direction along the longitudinal direction of the movable contactor. An example of a movable contactor is the movable contactor 3b. The left-right direction is a transverse direction that crosses the up-down direction and is a direction along the lateral direction of the movable contactor. The up-down direction is a general term for the upward and downward directions that are opposite to each other. The front-rear direction is a general term for the forward and backward directions that are opposite to each other. The left-right direction is a general term for the leftward and rightward directions that are opposite to each other.

[0013] The contact switch 1 is configured for use with, for example, a three-phase power supply and is disposed between a power supply and a load. As shown in FIG. 2, the contact switch 1 includes a contact unit 100 and a switching mechanism unit 110. As shown in FIG. 1, the contact unit 100 includes three arc-extinguishing chambers: a first-phase arc-extinguishing chamber 10a, a second-phase arc-extinguishing chamber 10b, and a third-phase arc-extinguishing chamber 10c. The second-phase arc-extinguishing chamber 10b is located between the first-phase arc-extinguishing chamber 10a and the third-phase arc-extinguishing chamber 10c. More specifically, the first-phase arc-extinguishing chamber 10a is adjacent to the second-phase arc-extinguishing chamber 10b, the second-phase arc-extinguishing chamber 10b is adjacent to the first-phase arc-extinguishing chamber 10a and the third-phase arc-extinguishing chamber 10c, and the third-phase arc-extinguishing chamber 10c is adjacent to the second-phase arc-extinguishing chamber 10b.

[0014] 1, the first-phase arc-extinguishing chamber 10a has a fixed contact 2a and a power supply terminal 21a corresponding to the fixed contact 2a. The second-phase arc-extinguishing chamber 10b has a fixed contact 2b and a power supply terminal 21b corresponding to the fixed contact 2b. The third-phase arc-extinguishing chamber 10c has a fixed contact 2c and a power supply terminal 21c corresponding to the fixed contact 2c. One-phase wiring of a three-phase power supply (not shown) is connected to each of the fixed contacts 2a, 2b, and 2c via a corresponding one of the power supply terminals 21a, 21b, and 21c.

[0015] As shown in Fig. 1, the first-phase arc-extinguishing chamber 10a further includes a fixed contact 2d and a load-side terminal 21d corresponding to the fixed contact 2d. The second-phase arc-extinguishing chamber 10b further includes a fixed contact 2e and a load-side terminal 21e corresponding to the fixed contact 2e. The third-phase arc-extinguishing chamber 10c further includes a fixed contact 2f and a load-side terminal 21f corresponding to the fixed contact 2f. Load wiring (not shown) is connected to each of the fixed contacts 2d, 2e, and 2f via a corresponding one of the load-side terminals 21d, 21e, and 21f. The contact switch 1 also includes a case cover 9 that covers the first-phase arc-extinguishing chamber 10a, the second-phase arc-extinguishing chamber 10b, and the third-phase arc-extinguishing chamber 10c.

[0016] 2 is a diagram showing the inside of the second phase arc extinguishing chamber 10b because it is a schematic diagram of the cross-sectional structure taken along line II-II in FIG. 1 as described above, but the structures of the first phase arc extinguishing chamber 10a and the third phase arc extinguishing chamber 10c are also the same as the structure of the second phase arc extinguishing chamber 10b. Therefore, the following will mainly describe the structure of the second phase arc extinguishing chamber 10b, and will omit redundant description of the structures of the first phase arc extinguishing chamber 10a and the third phase arc extinguishing chamber 10c.

[0017] 2, the second-phase arc-extinguishing chamber 10b has a contact section 100 and a switching mechanism section 110. The contact section 100 houses the movable contactor 3b, and the switching mechanism section 110 moves the movable contactor 3b housed in the contact section 100. The contact switch 1 has the same structure for each phase.

[0018] 2, the contact section 100 constituting the second-phase arc-extinguishing chamber 10b includes a fixed contact 2b provided with a fixed contact 22b, a movable contact 3b provided with two movable contacts 31b and 31e, a fixed contact 2e provided with the fixed contact 22e, a grid 11b provided near the fixed contact 22b and the movable contact 31b, and a grid 11e provided near the fixed contact 22e and the movable contact 31e. An example of the shape of each of the grid 11b and the grid 11e is a plate shape.

[0019] The second-phase arc extinguishing chamber 10b further includes two insulators 121b and 122b provided near the grid 11b and two insulators provided near the grid 11e. One of the two insulators provided near the grid 11b, insulator 122b, is shown in FIG. 3 (described later). One of the two insulators provided near the grid 11e is insulator 121e. The other insulator provided near the grid 11e has the same configuration as insulator 122b and is therefore not shown. This other insulator is different from insulator 121e, one of the two insulators provided near the grid 11e.

[0020] Fig. 3 is a first schematic diagram showing the contact unit 100 of the contact switch 1 according to embodiment 1. Fig. 4 is a second schematic diagram showing the contact unit 100 of the contact switch 1 according to embodiment 1. Fig. 5 is a third schematic diagram showing the contact unit 100 of the contact switch 1 according to embodiment 1. Fig. 6 is a perspective view showing the schematic configuration of the contact unit 100 of the contact switch 1 according to embodiment 1. Figs. 3, 4, 5, and 6 schematically show the structures of the case cover 9, the movable contact 3b, the fixed contact 2b, the grid 11b, and the two insulators 121b and 122b.

[0021] Fig. 4 is a schematic diagram of only the movable contactor 3b, where the N direction is the longitudinal direction and the M direction is the lateral direction. Fig. 5 is a diagram of Fig. 3 without the movable contactor 3b. Fig. 6 is a perspective view of Fig. 3 as viewed from the upper left. Fig. 7 is a cross-sectional view schematically showing the cross-sectional structure of the contact section 100 of the contact switch 1 according to embodiment 1. Fig. 7 is a cross-sectional view schematically showing the cross-sectional structure taken along line VII-VII in Fig. 3. Fig. 8 is a diagram showing the schematic configuration and operation flow of the contact section 100 of the contact switch 1 according to embodiment 1.

[0022] 3 to 8 show the positional relationship of the movable contactor 3b provided with the movable contact 31b, the fixed contactor 2b provided with the fixed contact 22b, the grid 11b provided near the fixed contact 22b and the movable contact 31b, and the two insulators 121b and 122b on the power supply side of one phase of a three-phase power supply. The structure on the power supply side of the other two phases is the same as the structure shown in the drawings from 3 to 8, and the structure on the three phases on the load side is also the same as the structure on the power supply side, so duplicated explanations will be omitted.

[0023] The grid 11b is made of a magnetic material such as iron. When the movable contact 31b and the fixed contact 22b come into contact with or separate from each other during current flow, the grid 11b forms a flow path that directs a portion of the hot gas that is generated together with an arc between the movable contact 31b and the fixed contact 22b and flows forward from the movable contact 31b or the fixed contact 22b to the side or rear of the movable contact 31b or the fixed contact 22b. In other words, the grid 11b has the function of changing the flow direction of a portion of the hot gas and returning the hot gas to the fixed contact 22b and the movable contact 31b.

[0024] 3 to 8, the grid 11b is disposed on an extension line of the longitudinal direction of the movable contactor 3b so that a front surface 111b of the grid 11b faces the movable contact 31b or the fixed contact 22b over most of its surface, and is characterized by having a length extending from above the upper surface of the movable contactor 3b to below the contact surface of the movable contact 31b with the fixed contact 22b at least when the movable contact 31b and the fixed contact 22b come into contact with or separate from each other. When the generated hot gas collides with the front surface 111b of the grid 11b, the front surface 111b can change or reverse its direction of travel in the left-right direction.

[0025] As described above, an example of the shape of each of the grid 11b and the grid 11e is a plate. The grid 11b does not necessarily have to be a single sheet. Even if multiple grids 11b are stacked in the longitudinal direction of the movable contactor 3b, i.e., the front-to-back direction, the same effect as that obtained when only one grid 11b is present can be obtained. In the case where multiple grids 11b are stacked, as long as even one grid 11b is arranged on an extension line of the longitudinal direction of the movable contactor 3b so that the front surface 111b of the grid 11b faces the movable contact 31b or the fixed contact 22b over most of its surface, and has a length extending from above the top surface of the movable contactor 3b to below the contact surface of the movable contact 31b with the fixed contact 22b when the movable contact 31b and the fixed contact 22b come into contact with or separate from each other, the same effect as that obtained when only one grid 11b is present can be obtained.

[0026] Although the first embodiment illustrates an example in which the grid 11b is perpendicular to the case cover 9, this is not limiting. The grid 11b may have an inclined or curved surface as long as the front surface 111b of the grid 11b faces the movable contact 31b or the fixed contact 22b over most of its surface. FIG. 9 is a cross-sectional view showing a schematic configuration of the contact unit 100 of the contact switch 1 according to the first embodiment. As shown in FIG. 9, the grid 11b may have an angle θ toward the movable contact 3b. This configuration facilitates upward circulation of hot gas circulating through the circulation path X1, further enhancing the arc cooling effect and arc driving force. The arc is quickly stretched toward the grid 11b, thereby quickly interrupting the arc and completing the arc interruption more quickly. The circulation path X1 will be described in detail later.

[0027] The return path X1 is a hot gas flow path in the space between the movable contact 31b and the fixed contact 22b sandwiched between the two insulators 121b and 122b. The return path X1 is indicated by an arrow. Note that the return path X1 has been described as the space between the movable contact 31b and the fixed contact 22b sandwiched between the two insulators 121b and 122b, but is not limited to this. If there is a space at a position lower than the height of the side surface of the insulator 121b or the insulator 122b on the side surface 91b or the side surface 92b of the case cover 9, that space may also be included in the return path X1.

[0028] As shown in FIG. 8 , the insulator 121b is arranged between the movable contact 31b or the fixed contact 22b and the side surface 91b of the case cover 9 to form a reflux path X2 for returning hot gas generated when the movable contact 31b and the fixed contact 22b come into contact with or separate from the fixed contact 22b to the fixed contact 22b and the movable contact 31b. The insulator 122b is arranged between the movable contact 31b or the fixed contact 22b and the side surface 92b of the case cover 9 to form a reflux path X3 for returning hot gas generated when the movable contact 31b and the fixed contact 22b come into contact with or separate from the fixed contact 22b to the fixed contact 22b and the movable contact 31b. The reflux path X2 and the reflux path X3 are indicated by arrows. Both the reflux path X2 and the reflux path X3 are hot gas paths.

[0029] It is not necessary to provide two insulators, but it is sufficient that the insulators are provided between at least one of the movable contact 31 b and the fixed contact 22 b and the side surface 91 b or the side surface 92 b of the case cover 9 .

[0030] As shown in Fig. 2, the contact unit 100 constituting the second-phase arc-extinguishing chamber 10b further has a crossbar 8. Also, as shown in Fig. 2, the opening / closing mechanism unit 110 constituting the second-phase arc-extinguishing chamber 10b has a movable iron core 4, a fixed iron core 5, an operation coil 6, and a tripping spring 7. The contact unit 100 and the opening / closing mechanism unit 110 are fixed together with screws 200.

[0031] The contact opening operation of the contact switch 1 according to the first embodiment configured as described above will be described mainly with reference to Fig. 2. When the excited operation coil 6 is de-energized, the movable core 4 is released from the fixed core 5 by the tripping spring 7. This causes the crossbar 8 to move, and the movable contact 3b moves upward in response to this movement.

[0032] When the movable contact 31b and the fixed contact 22b make contact with or separate from each other during current flow, an arc is generated between the movable contact 31b and the fixed contact 22b. The process of interrupting this arc will be described with reference to FIG. 7 . FIG. 7 also illustrates a schematic configuration and operational flow of the contact unit 100 of the contact switch 1 according to the first embodiment. Immediately after the movable contact 31b and the fixed contact 22b make contact with or separate from each other, an arc A is generated connecting the movable contact 31b and the fixed contact 22b. The grid 11b applies an electromagnetic force to the arc A in a direction from the movable contact 31b or the fixed contact 22b toward the front surface 111b of the grid 11b. This causes the arc A to move toward the front surface 111b of the grid 11b, and the shape of the arc A becomes pulled like the arc B. When the arc B is attracted to the grid 11b and comes into contact with the front surface 111b of the grid 11b, a current flows inside the grid 11b, and the arc B is interrupted like the arc C. Once the arc B is interrupted, the arc is interrupted.

[0033] The flow of a portion of the hot gas generated along with the arc between the movable contact 31b and the fixed contact 22b when the contacts are opened will be described with reference to FIG. 8 . Part of the hot gas flows through the return path X1, which is the direction from the movable contact 31b or the fixed contact 22b toward the grid 11b. The hot gas that hits the front surface 111b of the grid 11b branches to the left and right. The hatched arrows in FIG. 8 indicate the left and right flows of the hot gas that hits the front surface 111b of the grid 11b. The hot gas travels along the front surface 111b of the grid 11b and eventually flows through the return path X2 and the return path X3 in the opposite direction to the hot gas in the return path X1. Note that the hot gas does not necessarily have to branch at the front surface 111b of the grid 11b. Therefore, even if the hot gas is returned to at least one of the return paths X2 and X3, the same effect as that obtained when the hot gas branches at the front surface 111b of the grid 11b can be obtained. Alternatively, a portion of the hot gas flowing through the return path X1 may reverse its direction of travel and return to the fixed contact 22b (not shown). Because the return path X1 utilizes the front surface 111b of the grid 11b as part of the return path, the return of the hot gas acts as a driving force to make it easier for the arc to contact the grid 11b, allowing the arc to be quickly stretched and broken, resulting in faster arc interruption. Furthermore, the hot gas returning through the return paths X2 and X3 flows into the fixed contact 22b from the rear after passing through the return paths. Therefore, by returning the hot gas, the arc driving force in the same direction as the electromagnetic force acting on the arc and a cooling effect on the arc can be expected.

[0034] Focusing on the contact section 100 constituting the second-phase arc-extinguishing chamber 10b, the contact switch 1 includes a fixed contact 2b having a fixed contact 22b on its upper surface and a movable contact 3b having a movable contact 31b in contact with the fixed contact 22b on its lower surface. The contact switch 1 further includes a grid 11b formed of a magnetic material, facing the movable contact 3b in the longitudinal direction of the movable contact 3b when the fixed contact 22b and the movable contact 31b are in contact with each other, and formed above the upper surface of the movable contact 3b and below the contact surface of the movable contact 31b with the fixed contact 22b. The contact switch 1 further includes a case cover 9 located outside the fixed contact 2b, the movable contact 3b, and the grid 11b, and two insulators 121b and 122b located on the side surfaces of the movable contact 3b and forming a return path through which gas generated when the contacts are in contact with the case cover 9 flows. The contact switch 1 may have only one of the two insulators 121b, 122b.

[0035] According to the first embodiment, the arc generated between the contacts can be moved toward the grid 11b by electromagnetic force, and the hot gas generated along with the arc is circulated, thereby increasing the arc driving force in the same direction as the electromagnetic force acting on the arc and providing a cooling effect for the arc. Furthermore, by using the front surface 111b of the grid 11b as part of the circulation path, the circulating hot gas serves as a driving force to make the arc more likely to come into contact with the grid 11b, allowing the arc to be quickly stretched and broken, thereby completing the arc interruption more quickly. In other words, the contact switch 1 according to the first embodiment can improve the ability to interrupt the arc generated when the contacts are opened.

[0036] Embodiment 2. FIG. 10 is a diagram showing a schematic configuration of a contact unit 100 included in a contact switch according to embodiment 2. FIG. 10 illustrates the gas flow in the contact unit 100 according to embodiment 2. Unlike embodiment 1, embodiment 2 is characterized in that the gas outlet surface d of the return flow path is smaller than the gas inlet surface e of the return flow path. The return flow paths are return flow paths X2 and X3. For example, as shown in FIG. 10 , insulators 121b and 122b are arranged so that insulator 121b is inclined relative to side surface 91b of case cover 9 and insulator 122b is inclined relative to side surface 92b of case cover 9. As a result, gas outlet surface d is smaller than gas inlet surface e. The hatched arrows in FIG. 10 indicate the leftward and rightward flows of hot gas that strikes the front surface 111b of grid 11b.

[0037] In the above description, an example in which the insulators 121b, 122b are inclined with respect to the side surfaces 91b, 92b of the case cover 9 is described as a structure in which the gas outflow surface d is smaller than the gas inflow surface e. However, this is not limited to this, and the insulators 121b, 122b may be configured so that the gas outflow surface d is smaller than the gas inflow surface e. For example, the insulators 121b, 122b may be configured so that they are inclined in the vertical direction, and the height gradually decreases from the gas inflow surface e to the gas outflow surface d so that the gas outflow surface d is smaller than the gas inflow surface e. The size of the gas outflow surface d of the reflux channel X2 and the size of the gas outflow surface d of the reflux channel X3 do not necessarily need to be the same, and the size of the gas inflow surface e of the reflux channel X2 and the size of the gas inflow surface e of the reflux channel X3 do not necessarily need to be the same. In addition, the return flow path X2 or the return flow path X3 may be formed so that an insulator covers at least the upper or lower direction, thereby preventing the hot gas from flowing out in the upward or downward direction, and may include a structure in which the insulator covering the return flow path X2 or the return flow path X3 is tilted in the vertical direction so that the gas outflow surface d is smaller than the gas inflow surface e.

[0038] According to the second embodiment, the gas outlet surface d of the reflux path is smaller than the gas inlet surface e of the reflux path. This prevents backflow of hot gas within the reflux path and increases the flow rate of the hot gas from the gas outlet surface d. This not only achieves the effects of the first embodiment, but also improves reflux efficiency, increases the flow rate at which the hot gas is blown onto the movable contact 31b and the fixed contact 22b, further enhances the arc cooling effect and the arc driving force, and allows the arc to be quickly stretched and broken toward the grid 11b, thereby completing arc interruption more quickly. The reflux paths are the reflux path X2 and the reflux path X3. Note that the gas outlet surface d may be smaller than the gas inlet surface e in one of the reflux paths X2 and X3.

[0039] Embodiment 3. Figure 11 is a schematic diagram of a contact unit 100 included in a contact switch according to embodiment 3. Figure 12 is a cross-sectional view schematically illustrating the cross-sectional structure of the contact unit 100 included in a contact switch according to embodiment 3. Figure 12 is a cross-sectional view schematically illustrating the cross-sectional structure and gas flow taken along line XII-XII in Figure 11. Unlike embodiments 1 and 2, embodiment 3 is characterized in that an insulator 123b is disposed opposite the grid 11b in the direction of movement of the movable contactor 3b, specifically in an upward position. The insulator 123b is disposed on the movable contact 31b side as viewed from the grid 11b, and is disposed opposite the grid 11b in a position above the upper surface of the movable contactor 3b in the direction of movement of the movable contactor 3b.

[0040] When the contacts are opened, part of the hot gas generated along with the arc between the movable contact 31b and the fixed contact 22b flows from the movable contact 31b or the fixed contact 22b toward the grid 11b. The hot gas that hits the front surface 111b of the grid 11b branches left and right, but as shown in Figure 12, part of the hot gas that hits the front surface 111b of the grid 11b does not branch left and right, but instead turns back toward the movable contact 31b and the fixed contact 22b and flows further upward through a return path X4 of the movable contactor 3b. The return path X4 is indicated by an arrow.

[0041] Because the insulator 123b is provided, the contact unit 100 according to the third embodiment can divert hot gas flowing through the return path X4 into return path X5, which runs horizontally in the direction of movement of the movable contact 3b. Return path X5 is indicated by an arrow. Specifically, as shown in FIGS. 11 and 12 , the insulators 121b and 122b have a stepped shape with the grid 11b side lower so that the hot gas branched by the insulator 123b can easily flow into the return paths X2 and X3. The return path X4 is a path surrounded by the grid 11b, the insulators 121b and 122b, the case cover 9, and the upper surface of the movable contact 3b. The return path X5 is a path that branches the hot gas into the return paths X2 and X3 by the insulator 123b.

[0042] The hot gas does not necessarily need to be branched at the insulator 123b. Therefore, even if the flow direction of the hot gas is changed by the insulator 123b and the hot gas is returned to at least one of the return paths X2 and X3, the same effect as when the hot gas is branched at the insulator 123b and returned to both the return paths X2 and X3 can be obtained.

[0043] Although the insulator 123b has a linear shape parallel to the grid 11b, this is not limited to this, and the shape of the insulator 123b may be a shape that is inclined in the direction of the return path X2 or the return path X3, or a shape that has a convex portion in the direction of the grid 11b.

[0044] According to the third embodiment, in addition to the effects obtained in the first and second embodiments, the hot gas that has passed through the reflux path X4 can also be refluxed and sprayed onto the fixed contact 22b and the movable contact 31b, which further increases the reflux efficiency, improves the arc cooling effect and the arc driving force, and enables the arc to be quickly stretched and broken to the grid 11b, thereby completing the arc interruption more quickly.

[0045] Embodiment 4. Figure 13 is a schematic diagram showing the flow of gas in the contact unit 100 of a contact switch according to embodiment 4. In contrast to each of embodiments 1 to 3, embodiment 4 is characterized in that gas blowing ports 131b and 132b are provided on the side of movable contact 31b when viewed from front surface 111b of grid 11b. Gas blowing ports 131b and 132b are located on the side of movable contact 31b when viewed from grid 11b, and form a return path that directs hot gas flowing from return path X2 and return path X3 toward fixed contact 22b and movable contact 31b.

[0046] By providing gas blowing port 131b on the gas outlet side of reflux channel X2 and gas blowing port 132b on the gas outlet side of reflux channel X3, reflux channel X6 is added to the space sandwiched between insulator 121b and gas blowing port 131b, and reflux channel X7 is added to the space sandwiched between insulator 122b and gas blowing port 132b. Reflux channel X6 and reflux channel X7 are indicated by arrows.

[0047] When the contacts are opened, a portion of the hot gas generated along with the arc between the movable contact 31b and the fixed contact 22b flows from the movable contact 31b or the fixed contact 22b toward the grid 11b. The hot gas that strikes the front surface 111b of the grid 11b branches left and right. The hatched arrows in FIG. 13 indicate the leftward and rightward flows of the hot gas that strikes the front surface 111b of the grid 11b. The hot gas travels along the inner surface of the grid 11b and eventually flows through the return paths X2 and X3 in the opposite direction to the hot gas in the return path X1. The hot gas that has flowed through the return paths X2 and X3 strikes the gas blowing ports 131b and 132b, and then flows through the return paths X6 and X7 toward the movable contact 31b or the fixed contact 22b, where the hot gas is blown onto the movable contact 31b or the fixed contact 22b.

[0048] According to the fourth embodiment, in addition to obtaining the effects obtained in the first to third embodiments, hot gas can be efficiently sprayed onto the movable contact 31b and the fixed contact 22b, thereby enhancing the arc cooling effect and more reliably completing the arc interruption.

[0049] It is to be noted that one of the gas blowing ports 131b and 132b may not be provided.

[0050] Embodiment 5. Fig. 14 is a schematic diagram of a contact portion 100 included in a contact switch according to embodiment 5. Fig. 15 is a cross-sectional view showing the cross-sectional structure of the contact portion 100 included in a contact switch according to embodiment 5. Fig. 15 schematically shows the cross-sectional structure taken along line XV-XV in Fig. 14. In contrast to each of embodiments 1 to 4, embodiment 5 is characterized in that an insulator 124b is provided in a position in the moving direction of the movable contactor 3b, more specifically, in an upward position, so as to surround at least the movable contactor 3b in cooperation with insulators 121b and 122b.

[0051] Since the insulator 124b is disposed above the upper surface of the movable contact 3b, when the contacts are opened, the pressure rise of the hot gas generated by the arc generated between the movable contact 31b and the fixed contact 22b is strengthened, and the flow rate of the hot gas can be increased. If the insulator 124b is disposed above the upper surface of the movable contact 3b, the pressure rise of the hot gas generated by the arc generated can be strengthened. For example, as shown in Figure 14, by surrounding the return path X2 and the return path X3 with the side surface 91b of the case cover 9, the side surface 92b of the case cover 9, the insulator 121b, the insulator 122b, and the insulator 124b, it can be expected that the hot gas passing through the return path X2 and the return path X3 will be returned to the fixed contact 22b and the movable contact 31b without diverging upward.

[0052] According to the fifth embodiment, in addition to obtaining the effects obtained in the first to fourth embodiments, it is possible to expect an increase in the pressure of the hot gas due to the generation of an arc, and it is possible to increase the flow rate of the hot gas inside the circulation paths X1, X2, and X3. This increases the flow rate at which the hot gas is blown onto the movable contact 31b and the fixed contact 22b, further improving the arc cooling effect and the arc driving force, and it is possible to quickly stretch and break the arc to the grid 11b, thereby completing the arc interruption more quickly.

[0053] Sixth Embodiment Fig. 16 is a first schematic diagram showing a first example of a grid 11b included in a contact switch according to the sixth embodiment. Fig. 17 is a second schematic diagram showing a first example of a grid 11b included in a contact switch according to the sixth embodiment. Fig. 18 is a first schematic diagram showing a second example of a grid 11b included in a contact switch according to the sixth embodiment. Fig. 19 is a second schematic diagram showing a second example of a grid 11b included in a contact switch according to the sixth embodiment. In contrast to each of the first to fifth embodiments, the sixth embodiment is characterized in that at least one or more through holes Y1 or slits Y2 are formed in the grid 11b.

[0054] Since the grid 11b has a through hole Y1 or a slit Y2, the contact switch of embodiment 6 can discharge some of the hot gas inside the contact portion 100 through the through hole Y1 or the slit Y2, and by appropriately discharging the hot gas, the hot gas can be circulated without stagnation inside the circulation path.

[0055] According to the sixth embodiment, the hot gas inside the contact portion 100 can be appropriately discharged, and therefore, in addition to obtaining the effects obtained in the first to fifth embodiments, the hot gas can be circulated without stagnation inside the circulation path, which further increases the circulation efficiency of the hot gas and enables more reliable completion of arc interruption.

[0056] The grid 11b may be configured with a connection structure of a plurality of separately arranged members. Fig. 20 is a schematic diagram showing a first example of a grid 11b configured with the connection structure of the contact switch according to embodiment 6. As shown in Fig. 20, the grid 11b of the first example, which is provided with a through hole Y1, is configured with three members Y11, Y12, and Y13. Fig. 21 is a schematic diagram showing a second example of a grid 11b configured with the connection structure of the contact switch according to embodiment 6. As shown in Fig. 21, the grid 11b of the second example, which is provided with a slit Y2, is configured with three members Y21, Y22, and Y23. By using a connection structure for the grid 11b, it is possible to easily provide the through hole Y1 or the slit Y2 in the grid 11b.

[0057] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other, or part of the configuration may be omitted or modified within the scope of the gist of the invention.

[0058] 1 Contact switch, 2a, 2b, 2c, 2d, 2e, 2f Fixed contact, 3b Moving contact, 4 Moving core, 5 Fixed core, 6 Operation coil, 7 Tripping spring, 8 Crossbar, 9 Case cover, 10a First phase arc extinguishing chamber, 10b Second phase arc extinguishing chamber, 10c Third phase arc extinguishing chamber, 11b, 11e Grid, 21a, 21b, 21c Power supply side terminal, 21d, 21e, 21f Load side terminal, 22b, 22e Fixed contact, 31b, 31e Moving contact, 91b, 92b Side, 100 Contact portion, 110 Opening and closing mechanism portion, 111b Front, 121b, 122b, 121e, 123b, 124b Insulator, 131b, 132b Gas blowing port, 200 Screws, X1, X2, X3, X4, X5, X6, X7 return path, A, B, C arc, d gas outlet surface, e gas inlet surface, Y1 through hole, Y2 slit, Y11, Y12, Y13, Y21, Y22, Y23 members.

Claims

1. A contact switch comprising: a fixed contact on its upper surface; a movable contactor having a movable contact on its lower surface in contact with the fixed contact; a grid made of a magnetic material, facing the movable contactor in the longitudinal direction of the movable contactor when the fixed contact and the movable contact are in contact with each other, and formed above the upper surface of the movable contactor and below the contact surface of the movable contact with the fixed contact; a case cover located outside the fixed contactor, the movable contactor and the grid; and an insulator located on a side of the movable contactor and forming a return path through which gas generated when the contact is in contact with the case cover flows.

2. A contact switch as described in claim 1, characterized in that the area of ​​the gas inflow surface formed by the insulator and the case cover on the inflow side of the return path, which is the fixed contact side, is smaller than the area of ​​the gas inflow surface formed by the insulator and the case cover on the inflow side of the return path, which is the grid side.

3. A contact switch as claimed in claim 1 or 2, further comprising an insulator arranged to face the grid, on the movable contact side as seen from the grid, and above the upper surface of the movable contact in the direction of movement of the movable contactor.

4. A contact switch as claimed in any one of claims 1 to 3, further comprising a gas blowing port which is located on the movable contact side as seen from the grid and forms a return path for directing gas flowing from the return path towards the fixed contact and the movable contact.

5. A contact switch as claimed in any one of claims 1 to 4, further comprising an insulator arranged at a position above the top surface of the movable contactor so as to surround the movable contactor in cooperation with the insulator arranged on the side surface of the movable contactor.

6. A contact switch as claimed in any one of claims 1 to 5, characterized in that the grid is formed with either a through hole or a slit.

7. The contact switch according to claim 6, characterized in that the grid is constructed by connecting a plurality of separately arranged members.

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