JP2010205464A - Current limiting cutoff device - Google Patents

Abstract

The current limiting circuit breaker requires a large number of solid state switches, and thus has a problem that reliability is deteriorated due to malfunction.
A predetermined number of fixed contacts 2 arranged in a row at intervals from each other, a resistance element 6 electrically connected to each of the adjacent fixed contacts, and a predetermined number of fixed contacts are movable contact portions. It is provided so as to be able to move in a direction further away from the fixed contact at the other end via the arc space S after being sequentially slid and moved from one end of the contact to the other end. A movable contact 4 formed so as to maintain electrical connection to at least one of the fixed contacts, and the movable contact is positioned at the fixed contact at the one end when closed, and the movable contact is positioned when shut off. The resistor was moved in the direction of the fixed contact at the other end to increase the resistance in order to suppress the current and then opened.
[Selection] Figure 1

Description

  The present invention relates to a current limiting interrupting device that interrupts a circuit after a current is suppressed by resistance when receiving an interrupt command.

  In the arc extinguishing device connected to the electric circuit between the power source and the load as a conventional current limiting device, when connected to the electric circuit and closed, the power source and the load are connected and opened. Includes a circuit switch for commutating current to a commutation circuit connected in parallel, and the commutation circuit includes a plurality of commutation branch circuits connected in parallel to the arc-extinguishing device. Each includes a solid commutation switch, a buffer capacitor connected in parallel to the solid commutation switch, the solid commutation switch, and an arc extinguishing device including a resistor connected in series to the capacitor (for example, Patent Document 1). reference).

  In addition, the movable side contact portion provided on the movable electrode and the fixed side contact portion provided on the fixed electrode are disposed so as to be able to contact and separate from each other, an arc guide is extended on the movable electrode side, and the fixed electrode side is provided on the fixed electrode side. A plurality of resistor elements and arc runners, which are alternately stacked, are provided, and an arc generated when the movable contact portion and the fixed contact portion are separated is driven by a magnetic field generated by the movable electrode and the fixed electrode by an energizing current. In this case, a gap formed between the arc guide and the working end of each arc runner is caused to travel, and as the arc travels, the resistance is increased to limit the current and cut off (for example, Patent Documents). 2). In addition, a circuit in which a resistance element and an interruption contact are connected in series to the main contact is configured in parallel. When the interruption occurs, the main contact is opened, current is commutated to the resistance element, the current is reduced, and then the interruption contact is opened to cut off the current. (For example, refer to Patent Document 3).

Japanese Patent Laid-Open No. 11-297170 (pages 4 to 5, FIGS. 1 and 2) JP 2000-11826 (page 3, FIGS. 1 to 3) Japanese Patent Laid-Open No. 5-20984 (2nd page, FIG. 4, FIG. 5)

In the current limiting interrupt device as shown in Patent Document 1, since a large number of solid state switches are required, there is a problem that the reliability is reduced due to malfunction. Also used as solid state switches, such as insulated gate bipolar transistor (IGBT), metal-oxide-semiconductor field effect transistor (MOSFET), gate turn-off (GTO), MOS controlled thyristor (MCT), etc. A controllable semiconductor solid-state switching element having an opening / closing capability also has a problem of becoming conductive when it fails.
Moreover, in the current limiting interruption mechanism as shown in Patent Document 2, an arc is generated between the contacts after the contact is opened, and the resistance is inserted by running the arc to limit the current, When the arc stagnates between the contacts, there is a problem that contact consumption increases.

  Furthermore, in the current limiting interrupt device as shown in Patent Document 3, the main contact is opened and the arc is generated and commutated to the resistance circuit. When the arc is generated, the consumption of the main contact is unavoidable, and the main contact is disconnected when a large current such as a short circuit current flows. In addition, even with a resistive contact arranged in series with a resistive element, even if the current is limited by the connected resistive element, the breaking current of the resistive contact is larger than the rated current, so there is a problem with the consumption of the resistive contact. There was a point. Furthermore, in this method, when the voltage is high, a large resistance element is required to reduce the current to 10 A or less, and further to 1 A or less. However, when a large resistance element is inserted, even if the main contact is opened, it occurs at the main contact. Since the arc is difficult to commutate to the resistance element and the arc is maintained between the main contacts for a long time, the arc cannot be interrupted until commutation occurs. There is a problem that the contact wear increases as the arc duration increases.

  The present invention has been made to solve the above-described problems of the prior art, and can reduce the number of switches, ensure commutation, and suppress contact consumption due to arcing. The purpose is to obtain a reliable current limiting circuit breaker.

  The current-limiting circuit breaker according to the present invention includes a predetermined number of fixed contacts arranged in a row at intervals, a resistance element electrically connected to each of the adjacent fixed contacts, and a movable contact portion as described above. After a predetermined number of fixed contacts are sequentially slid from one end to the other end, the fixed contacts at the other end are provided so as to move further away from the fixed contact via the arc space. A movable contact formed to maintain an electrical connection to at least one of the adjacent fixed contacts, and the movable contact is positioned at the fixed contact at the one end when closed, and the movable contact when disconnected The element is moved in the direction of the fixed contact at the other end to sequentially increase the resistance, and the current is suppressed and then opened.

  In the present invention, when the circuit is interrupted, the resistance is gradually increased from a small resistance value to a large resistance value, the current is reduced, and then the contact is opened to interrupt the current. It can be constructed, and mechanical reliability can be improved. Further, since commutation is performed reliably and the energy of arc generated at the time of interruption can be reduced, contact consumption due to arc can be suppressed and reliability can be improved.

The figure which shows notionally the principal part of the current limiting circuit breaker by Embodiment 1 of this invention. The circuit diagram explaining the connection of the resistance element with respect to the fixed contact of the current limiting interruption | blocking apparatus shown by FIG. The figure which shows notionally the principal part of the current limiting circuit breaker by Embodiment 2 of this invention. The circuit diagram explaining the connection of the resistive element with respect to the fixed contact of the current limiting interruption | blocking apparatus shown by FIG. The figure which shows notionally the principal part of the current limiting circuit breaker by Embodiment 3 of this invention. The block diagram which shows the detail of the interruption | blocking part of the current limiting interruption | blocking apparatus shown by FIG. Operation | movement explanatory drawing which shows the middle of the opening of the interruption | blocking part shown by FIG. The figure explaining the interruption | blocking state of the interruption | blocking part shown by FIG.

Embodiment 1 FIG.
Hereinafter, a current limiting device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2. In the figure, the current-limiting circuit breaker includes a predetermined number (11 in this example) of fixed contacts 2 (2a to 2) arranged in an arc shape with a predetermined distance from each other on an insulating member 1 made of an arc-shaped plate material. 2k), a driving device 3 such as a motor provided so that the driving shaft 3a is positioned at the center of an arc formed by the fixed contact 2, and a fixed contact in which the movable contact portion 4a is fixed to the driving shaft 3a. After sequentially sliding and moving in the direction of the fixed contact 2k at the other end from the fixed contact 2a at one end of the contact 2, it is rotated and moved further away from the fixed contact 2k at the other end (2k) via the arc space S. The movable contact 4 provided so as to be able to be fixed, the insulating support member 5 for fixing the insulating member 1 and the driving device 3, and the insulating support member 5 are fixed to each other and electrically connected to the adjacent fixed contacts 2 respectively. A plurality of resistance elements 6 (6a to 6j) are used. It is configured Te.

  The resistance elements 6a to 6j are formed in a ring shape or a cylindrical shape having a through hole in the center, and a plate having a through hole with respect to the insulating rod 7 standing on the insulating support member 5 as shown in FIG. Are laminated so as to be alternately fitted with metal terminals 8 (8a to 8k), and are integrally tightened by nuts 11 via insulators 9 and 10 disposed at both ends, and on insulating support member 5 It is fixed to. As shown in FIG. 2, the terminal 8a at one end is connected to the fixed contact 2a at one end, the terminal 8b is connected to the fixed contact 2b, the terminal 8c is connected to the fixed contact 2c, and so on. The other terminal 8k is connected to the other fixed contact 2k. In FIG. 1, a plurality of conductors that connect the terminal 8 and the fixed contact 2 are not shown, but are electrically connected on the back side of the fixed contact 2 (2a to 2k).

  In addition, the movable contact portion 4a formed at the distal end portion of the movable contact 4 is formed so as to straddle a plurality of adjacent fixed contacts 2 in the circumferential direction, and at least of the adjacent fixed contacts 2 at the time of sliding movement. It is formed so that electrical connection to one side is maintained. As shown in FIG. 2, the fixed contact 2 a and the end 4 b of the movable contact 4 are connected to an external circuit (detailed illustration is omitted). For example, the fixed contact 2a is connected to the power supply side, and the end 4b of the movable contact 4 is connected to the load side. Further, the drive device 3 is not necessarily limited to a motor, and it is sufficient that the drive shaft 3a can be rotated by an actuator, a spring, or the like. Moreover, although the example in which the drive shaft 3a is directly connected to the output shaft of the drive device 3 such as a motor is illustrated, the drive shaft 3a may be driven by the drive device 3 through a gear or the like. Note that the detection means such as a short circuit and the control means including the drive circuit of the drive device 3 are parts that can select and use the prior art without any particular limitation, and thus illustration and description thereof are omitted.

  Next, the operation of the first embodiment configured as described above will be described. First, at the time of normal energization, the movable contact 4 is in a position where it is connected only to the fixed contact 2a at one end, and the current is connected to the external circuit from an external circuit (power supply side) not shown. The movable contact 4 flows through the fixed contact 2a and flows into the movable contact 4a of the movable contact 4 electrically and mechanically in contact with the fixed contact 2a. It flows from the end 4b to an external circuit (load side) not shown. At this time, the current flows without passing through the resistance element 6 that suppresses the current.

  Next, the case of blocking will be described. When a cut-off command is issued by a control means (not shown), the drive shaft 3a is rotated by the drive device 3, and the movable contact 4 mechanically attached to the drive shaft 3a is centered on the drive shaft 3a. In the upper direction, as shown by the broken arrow A, the movable contact 4 is rotated from the position A to the position B. After the sliding contact is sequentially performed on the fixed contacts 2a to 2k, the movable contact 4 is further moved. Rotate to position c. When the movable contact portion 4a of the movable contact 4 is at the position of the fixed contact 2a, the resistance element 6 is not inserted. However, when the movable contact portion 4a moves to the fixed contacts 2b, 2c, and 2d, the value of the resistance element 6 becomes the resistance element 6a as it moves. The resistance elements 6a + 6b and the resistance elements 6a + 6b + 6c are sequentially connected and inserted in series to increase the resistance value. At the position of the fixed contact 2k, all of the resistance elements 6a to 6j are connected in series.

  In the middle of the rotational movement of the movable contact 4, the movable contact portion 4 a comes into contact with a plurality of adjacent fixed contacts 2. For example, the movable contact portion 4a of the movable contact 4 is formed so as to be in contact with a plurality of adjacent fixed contacts 2f, 2g, and 2h at the same time as shown in the position of B. In this configuration, the movable contact portion 4a of the movable contact 4 is configured to come into contact with one, two, or three of the plurality of adjacent fixed contacts 2 during the rotation. In addition, although the number of the several adjacent fixed contacts 2 which the movable contact part 4a of the movable contactor 4 contacts simultaneously in the middle of rotation showed three examples, it is not limited to this, A movable contact part It suffices if contact is maintained with both of the two adjacent fixed contacts 2 when 4a is positioned between the adjacent fixed contacts 2.

  When the movable contact portion 4a rotates and the rear end portion in the rotation direction moves away from the fixed contact 2a and moves to the fixed contact 2b and commutates to the resistance element 6a, an arc is generated between the movable contact portion 4a and the fixed contact 2a. Although it occurs, the arc generated can be made minute by selecting the direction of decreasing the resistance value of the resistance element 6a, for example, 1Ω or less. The resistance values of the resistance elements 6a to 6j are determined by the arc resistance of the fixed contacts 2a to 2k. In addition, as an electrode material which can be preferably used for the movable contact part 4a and the fixed contact 2, for example, Cu, C, Ag, Cu-W, Cu-C, Ag-W, Ag-C, Cu-Cr, SUS, etc. Can be mentioned. These materials may be used in combination of two or more, and are not limited to the electrode materials exemplified above.

  When the movable contact portion 4a of the movable contact 4 moves to the fixed contact 2k, which is the other end, and further rotates and moves to position C, an arc 12 is generated between the fixed contact 2k and the movable contact portion 4a. . The minimum current for maintaining the arc varies depending on the material used for the electrode and the case where different metals are combined in the electrode, but is often 1 A or less. Incidentally, when the electrode is, for example, pure metal Cu, the minimum arc maintaining voltage Vmin in air is 12 to 13 V, the minimum arc maintaining current Imin is 0.5 to 0.7 A, and in the case of Ag, Vmin is 11 to 11 V. 13V and Imin are 0.4-0.9A. (Source: “Revised New Edition Discharge Handbook”, 7th edition, published by the Institute of Electrical Engineers, Ohm, Inc.)

  The resistance value of the resistance element 6 depends on the total resistance value of the resistance element 6 from the resistance element 6a to the resistance element 6j between the terminal 8a and the terminal 8k when the fixed contact 2k and the movable contact portion 4a are in contact. The current is adjusted to 10 A or less, preferably 1 A or less. For example, when the circuit voltage is 1000 V, the value of the resistance element 6 is set to 100Ω or more for direct current in order to suppress the current to 10 A or less, and 1.414 times that for AC, and the value of the resistance element 6 is controlled to 1 A or less. It is desirable that it be 1000Ω or more for direct current and 1.414 times that for alternating current. Furthermore, it is of course desirable to select the total resistance value of the resistance element 6 to a value that is equal to or less than the minimum arc maintenance current.

  The arc 12 generated between the fixed contact 2k and the movable contact portion 4a in the arc space S is further reduced as the distance between the fixed contact 2k and the movable contact portion 4a increases due to the arc resistance of the arc 12. . In the case of a direct current, when the current becomes smaller than the minimum arc maintenance current due to arc resistance, the arc disappears and the current is interrupted. On the other hand, in the case of alternating current, the current is cut off when the current becomes smaller than the minimum arc maintenance current due to the arc resistance or the insulation between the electrodes withstands the regenerated voltage after the current once cuts off at the current zero point. The

  Therefore, before the fixed contact 2k and the movable contact portion 4a are opened, the arc can be easily extinguished by suppressing the current close to or less than the minimum arc maintaining current by the resistance element 6. It is possible to cut off the current with little electrode wear due to arc. By setting the current to be equal to or less than the minimum arc maintaining current by the total resistance value of the resistance element 6, the movable contact portion 4a is separated from the fixed contact 2k, and an arc 12 is generated between the fixed contact 2k and the movable contact portion 4a. However, since the current is below the minimum arc maintaining current due to the total resistance value of the resistance element 6, the arc is immediately extinguished.

  As described above, in the first embodiment, the plurality of fixed contacts 2a to 2k are arranged at intervals, and the resistance elements 6a to 6j are electrically connected between the adjacent fixed contacts, respectively. During normal load current energization, the movable contact portion 4a provided at one end of the movable contact 4 is in contact with the fixed contact 2a at one end of the plurality of fixed contacts 2, and the resistance elements 6a to 6j are not inserted. When the shut-off command is input, the movable contact 4 is driven by the driving device 3, and the movable contact portion 4a is moved in the direction from the fixed contact 2a at one end to the fixed contact 2k at the other end and the fixed contact before moving and the fixed contact at the moving destination. These are configured to move while in contact with at least two adjacent fixed contacts.

  Then, as the movable contact portion 4a sequentially moves between the adjacent fixed contacts, the resistance element 6 electrically connected between the adjacent fixed contacts is in contact with the fixed contact 2a at one end and the movable contact portion 4a. It is connected in series between the contacts 2b to increase the resistance and suppress the current. When the movable contact portion 4a reaches the fixed contact 2k at the other end, resistance elements 6a to 6j between the fixed contact 2a at one end and the fixed contact 2k at the other end are connected in series. The movable contact portion 4a that is suppressed to 1A or less and contacts the fixed contact 2k at the other end is further driven, and the movable contact portion 4a is separated from the fixed contact 2k at the other end.

  According to the first embodiment, since the current at the time of interruption is suppressed to 10 A or less, preferably 1 A or less by the resistance element 6, arc energy (Varc × Iarc × tarc, where Varc: arc voltage, Iarc: Since the arc current (tarc: arc time) can also be kept small, damage to the fixed contact 2k and the movable contact portion 4a where the arc is generated can be reduced. In addition, with the above configuration, a small resistance value is increased to a large resistance value by using one movable contact portion 4a and a plurality of fixed contacts 2, and the current is reduced to about several A, and then the contact is opened. Since the release current is cut off, the number of switches can be reduced, the mechanical reliability can be improved, and the arc energy generated during the cut-off is small, so that the contact consumption due to the arc can be suppressed and the commutation is performed reliably. Is called.

  Furthermore, a plurality of fixed contacts 2 (2a to 2k) are arranged on the arc at intervals on a trajectory in which the movable contact portion 4a of the movable contact 4 moves while drawing an arc around the drive shaft 3a. Therefore, the movable contact portion 4a is driven in a curved manner on the arc, so that the design can be made more compact. Further, when the drive distance of the movable contact portion 4a is increased, it can be varied by increasing the distance between the movable contact portion 4a and the drive shaft mounting portion at the other rotation center of the movable contact 4 at the same rotation angle. Therefore, it is possible to make a compact design according to the specifications, and to reduce the environmental load in the production process. Although the number of fixed contacts 2 is 11 (the number of resistance elements 6 is 10), it goes without saying that the number can be appropriately increased or decreased according to the circuit voltage or the like. Since the distance between the fixed contact 2k and the movable contact portion 4a in the arc space S can also be adjusted by adjusting the rotation angle, a compact design can be made according to the specification.

Embodiment 2. FIG.
Next, a current limiting device according to Embodiment 2 of the present invention will be described with reference to FIGS. Note that the same or corresponding parts are denoted by the same reference numerals throughout the drawings. In the drawing, a predetermined number of fixed contacts 2 (2a to 2k) spaced apart from each other are arranged in an arc shape with respect to the insulating member 1 and are insulated and held. On the other hand, the movable contact 4 rotated by the driving device 3 is formed in a rod shape, and the movable contact portion 4a formed by the tip surface of the fixed contact 2 (2a to 2k) arranged in an arc shape. It is configured to slide relative to the peripheral surface portion B.

  Each of the fixed contacts 2 (2a to 2k) is held so as to be movable by a minute amount independently of each other in the radial direction with respect to the insulating member 1. An elastic member such as a spring (not shown) is arranged on the opposite surface of each fixed contact 2 (2a to 2k) that does not come into contact with the movable contact portion 4a, in the direction of the drive shaft 3a at the center of the arc. Is configured to be able to hold the electrical contact with the movable contact 4 by applying a predetermined contact pressure to the movable contact 4a when the movable contact 4a is slid and moved. Has been. The elastic member for applying the contact pressure may be provided on the movable contact 4 side so that the movable contact portion 4a is always urged in the radial direction. Further, the effective width of the movable contact portion 4a in the rotational direction is formed larger than the interval between the adjacent fixed contacts 2. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  The second embodiment configured as described above basically operates in the same manner as in the first embodiment both during normal energization and during interruption. That is, during normal energization, the movable contact 4 is in the position of A, and current flows from the external circuit (power supply side) through the fixed contact 2a, the movable contact 4a, and the movable contact 4, and the end 4b of the movable contact 4 To the external circuit (load side) without passing through the resistance element 6. On the other hand, when the shut-off command is issued, the driving device 3 rotates the driving shaft 3a in the direction of the broken arrow A, and the movable contact 4 rotates around the driving shaft 3a in the clockwise direction. Rotating from position (b) to position (b) and position (c), it slides and moves. As the movable contact portion 4a of the movable contact 4 moves in the direction of the fixed contacts 2b, 2c, and 2d, the resistance elements 6 are sequentially arranged in series so that the resistance element values are the resistance element 6a, the resistance element 6a + 6b, and the resistance element 6a + 6b + 6c. The resistance value increases by being inserted and connected, and all of the resistance elements 6a to 6j are connected in series at the position of the fixed contact 2k.

  In the middle of the rotational movement, the movable contact portion 4 a of the movable contact 4 comes into contact with a plurality of adjacent fixed contacts 2. For example, as shown in the position of B, the movable contact portion 4a of the movable contactor 4 comes into contact with a plurality of adjacent fixed contacts 2f and 2g. In this configuration, the movable contact portion 4a of the movable contact 4 is configured to contact one or two of the plurality of adjacent fixed contacts 2 during the rotation. In addition, the movable contact part 4a of the movable contact 4 should just be in contact with the some fixed contact 2 adjacent in the middle of rotation.

  As described above, according to the second embodiment, the driving distance of the movable contact portion can be changed by the distance between the movable contact portion and the rotating shaft attaching portion at the other end of the movable contact. A compact design is possible at a moving angle. In addition, when switching off, the switch is increased stepwise from a small resistance value to a large resistance value, and after reducing the current, the contact is opened to cut off the current, so the number of switches can be reduced, Since the mechanical reliability can be improved and the energy of the arc generated at the time of interruption can be reduced, the same effects as those of the first embodiment can be obtained, such as the suppression of contact consumption due to the arc.

  In the first embodiment and the second embodiment, the example in which the movable contact portion 4a of the movable contact 4 is in contact with only the fixed contact 2a and is electrically connected during normal energization is shown. The movable contact portion 4a may be in contact with a plurality of adjacent fixed contacts including the fixed contact 2a, for example, may be in contact with the adjacent fixed contact 2b. Furthermore, you may straddle over all the adjacent contacts 2a-2j including the fixed contact 2a. When the movable contact portion 4a comes into contact across all adjacent contacts 2a to 2j during normal energization, all the resistors are connected in parallel, and when the cutoff command is received, the movable contact portion 4a of the movable contact 4 is driven. It moves while drawing an arc around 3a, and sequentially separates from the fixed contacts 2a to 2j, and the resistors connected in parallel are connected in series. In this case, the same effects as those of the first and second embodiments can be obtained, and since the resistance value becomes smaller than the smallest resistance value connected in parallel, commutation is facilitated.

Embodiment 3 FIG.
Next, a current limiting interrupting device according to Embodiment 3 of the present invention will be described with reference to FIGS. In the third embodiment, a predetermined number of fixed contacts 2 (2a to 2k) are linearly arranged and the movable contact 4 is linearly moved. In the figure, the current limiting interrupter is constituted by an interrupter 20 and a resistor 60. As shown in FIG. 6, a predetermined number (11 in this example) of fixed contacts 2 (2 a to 2 k) arranged in a straight line at predetermined intervals are formed on the blocking portion 20 from a plate material. The insulating member 1 is insulated and held. The insulating member 1 is held so that both end portions are mechanically sandwiched between the fixing members 21 and 22, and is fixed to the insulating support member 5 via the fixing members 21 and 22. On the opposite side of the fixed member 22 from the fixed contact 2, a driving device 3 made of an actuator is fixed to the insulating support member 5.

  The drive shaft 3a of the drive device 3 is provided so as to move linearly in the direction of arrow C when interrupted parallel to the direction in which the fixed contacts 2 are arranged, and one end of the drive shaft 3a opposite to the fixed contact 2 is connected to the connecting member. The movable contact 4 is fastened to one end of the movable contact 4 via the nut 23 and the nuts 11 and 24, and is connected to the movable contact 4. At the other end of the movable contact 4 on the fixed contact 2 side, a movable contact 4a that contacts the fixed contact 2 is provided, and contact pressure is applied to the side of the movable contact 4 that faces the surface on which the movable contact 4a is provided. An application unit 25 is provided, and a roller 26 attached to the contact pressure application unit 25 is pressed upward by a spring (not shown) in the contact pressure application unit 25.

  An insulating frame member 27 on which the pressed roller 26 rolls is provided above the roller 26 in the figure. One end of the frame member 27 is fixed to the fixing member 21, and the other end side of the frame member 27 is a slide in which an insulator contact fixing member 28, a current lead-out terminal 29, and a sliding contact portion 30 are mechanically connected. The contact fixing member 28 is fixed to the insulating support member 5. Since the frame member 27 is fixed, the force that presses the roller 26 upward is the contact pressure that presses the movable contact portion 4a toward the fixed contact 2 side.

  The sliding contact portion 30 is provided with a hole 30a through which the movable contact 4 is passed, and even if the movable contact 4 slides inside the hole 30a, it has a spring property that keeps electrical contact. A coil contact 30b is provided, and the sliding contact 30 and the movable contact 4 are always in electrical contact. In FIG. 6, the sliding contact portion 30 is schematically shown in cross section, and the spring-like coil contact 30 b is made of, for example, a ring-shaped conductive plate material having spring elasticity. A current introduction terminal 31 for introducing a current from a power supply side circuit (not shown in detail) is electrically connected to the lower portion of the fixed contact 2a in the figure. A current deriving terminal 29 for deriving a current to a load side circuit (not shown in detail) is electrically connected to the sliding contact portion 30.

  The resistor portion 60 shown in FIG. 5 has a plate-like shape in which the resistance elements 6a to 6j similar to the first embodiment formed in a ring shape or a cylindrical shape having a through hole in the central portion have a through hole in the insulating rod 7. The metal terminals 8 (8a to 8k) are alternately stacked and are integrally clamped by the nut 11 via the insulators 9 and the resistor fixing members 61 disposed at both ends. A fixing member 61 is fixed to the insulating support member 5. In FIG. 5, a plurality of conductors connecting the terminal 8 (8a to 8k) and the fixed contact 2 (2a to 2k) are not shown, but the lower surface side of the fixed contact 2 (2a to 2k) shown in FIG. Are electrically connected.

  The terminal 8a at one end is electrically connected to the fixed contact 2a at one end, the terminal 8b is electrically connected to the fixed contact 2b, the terminal 8c is electrically connected to the fixed contact 2c, and so on. Are connected to the other fixed contact 2k. Note that the driving device 3 is not necessarily limited to an actuator, and it is sufficient that the movable contact 4 can be linearly driven in the left-right direction in the figure by an air cylinder, a spring, a motor, or the like. Note that the detection means such as a short circuit, the control means including the drive circuit of the drive device 3 and the like are portions that can be used by appropriately selecting the conventional technique without any particular limitation, as in the first embodiment. Illustration and description are omitted.

  Next, the operation of the third embodiment configured as described above will be described. First, during normal energization, the movable contact 4 is in the position of FIG. 6 connected to the fixed contact 2a at one end, and the current is connected to the external circuit from an external circuit (power supply side) not shown. The current introduction terminal 31 and the fixed contact 2a electrically and mechanically connected to the current introduction terminal 31 are passed through the fixed contact 2a from the lower part of the figure and brought into electrical and mechanical contact with the fixed contact 2a. Flows into the movable contact 4a of the movable contact 4 that flows, flows through the movable contact 4, and flows into the sliding contact 30 that is in electrical contact with the movable contact 4 and the coil contact 30b. The current flows from the current deriving terminal 29 electrically and mechanically connected to the contact portion 30 to the external circuit (load side). At this time, the current flows without passing through the resistance element 6 (6a to 6j) for suppressing the current.

  Next, the case of blocking will be described. When a cutoff command is issued by a control means (not shown), the drive shaft 3a is linearly driven by the drive device 3 in the direction of arrow C, and the movable contact is mechanically attached to the drive shaft 3a via the connecting member 23. 4 moves in the direction of arrow C in FIG. 2 along with the movement of the drive shaft 3a. For example, the movable contact portion 4a slides and moves on the fixed contacts 2a to 2k sequentially through the position in FIG. After that, it moves further away from the fixed contact 2k through the arc space S with respect to the fixed contact 2k at the other end, and moves to the position of FIG.

  When the movable contact portion 4a of the movable contactor 4 is at the position of the fixed contact 2a, the resistance element 6 is not inserted. However, when the movement is made from the fixed contact 2b → 2c → 2d, the value of the resistance element 6 becomes the resistance element 6a. The resistance elements 6a + 6b and the resistance elements 6a + 6b + 6c are sequentially connected and inserted in series to increase the resistance value. At the position of the fixed contact 2k, all of the resistance elements 6a to 6j are connected in series. During the linear movement of the movable contact 4, the movable contact portion 4 a comes into contact with a plurality of adjacent fixed contacts 2. For example, as shown in the position of FIG. 7, the movable contact 4a of the movable contact 4 is formed so as to be in contact with a plurality of adjacent fixed contacts 2f and 2g simultaneously.

  In this configuration, the movable contact portion 4a of the movable contact 4 is configured to contact one or two of the plurality of adjacent fixed contacts 2 during the movement. In addition, although the number of the several adjacent fixed contacts 2 which the movable contact part 4a of the movable contact 4 contacts simultaneously in the middle of linear movement showed two examples, it is not limited to this, A movable contact part When the contact 4a is positioned in the middle of the adjacent fixed contacts 2, it is only necessary to maintain contact with both of the two adjacent fixed contacts 2. For example, the width of the movable contact portion 4a in the sliding direction is increased by 3 It may be in contact with more than one.

  When the movable contact portion 4a moves linearly in the direction of arrow C, the rear end portion in the moving direction moves away from the fixed contact 2a, moves to the fixed contact 2b, and commutates to the resistance element 6a, as in the first and second embodiments, An arc is generated between the movable contact portion 4a and the fixed contact 2a, but the generated arc can be made minute by selecting the direction of decreasing the resistance value of the resistance element 6a, for example, 1Ω or less. it can. Note that the resistance values of the resistance elements 6a to 6j, the electrode materials that can be preferably used for the movable contact portion 4a and the fixed contact 2 are the same as those in the first and second embodiments, and thus the description thereof is omitted.

  As described above, according to the third embodiment, the same effect as in the first and second embodiments can be obtained, and the fixed contacts 2a to 2k are arranged in a straight line, and the movable contact 4 is moved linearly. For example, when the driving distance of the movable contact portion 4a is increased, it can be handled by increasing the number of fixed contacts on the same straight line. For this reason, it is possible to cope with a simple design change according to the specification, and the environmental load in the production process can be reduced. Although the number of fixed contacts 2 is 11 (the number of resistance elements 6 is 10), it goes without saying that the number can be appropriately increased or decreased according to the circuit voltage or the like. In addition, since the separation distance between the fixed contact 2k and the movable contact portion 4a in the arc space S is also possible by adjusting the dimension in the linear direction, an effect that the design change according to the specification is easy can be obtained.

  As described in the third embodiment, for example, the means for linearly driving the movable contact 4, the means for bringing the movable contact portion 4 a into contact with the fixed contact 2, and the electrical connection between the linearly movable movable contact 4 and the current deriving terminal 29. Needless to say, none of the means for securing the connection or the arrangement of these is limited to the illustrated one. For example, various modifications and changes are possible, such as directly connecting the movable contact 4 and the drive shaft 3a, or reducing the size by interposing a link mechanism or the like between the movable contact 4 and the drive shaft 3a. Needless to say. Moreover, although the interruption | blocking part 20 and the resistor part 60 were comprised separately, for example, a resistive element may be inserted | pinched between adjacent fixed contacts, respectively, and you may comprise so that a fixed contact and a resistive element may be integrated. In that case, further effects such as the need for the terminal 8 and the connection cable can be obtained.

  DESCRIPTION OF SYMBOLS 1 Insulation member, 2 (2a-2k) Fixed contact, 3 Drive apparatus, 3a Drive shaft, 4 Movable contactor, 4a Movable contact part, 4b End part, 5 Insulation support member, 6 (6a-6j) Resistance element, 7 Insulating rod, 8 (8a-8k) terminal, 9, 10 insulator, 11 nut, 12 arc, 20 interrupting part, 25 contact pressure applying part, 29 current deriving terminal, 31 current introducing terminal, 60 resistor part, S arc space.

Claims (4)

  A predetermined number of fixed contacts arranged in a row at intervals, a resistance element electrically connected to each of the adjacent fixed contacts, and a movable contact portion from one end to the other end of the predetermined number of fixed contacts After being sequentially slid and moved in the direction, the electric power to at least one of the adjacent fixed contacts is provided so as to move further away from the fixed contact at the other end via the arc space. A movable contact formed so as to maintain a general connection, the movable contact is positioned at the fixed contact at the one end when closed, and the movable contact is directed toward the fixed contact at the other end when closed. A current limiting interrupter that is opened after it has been moved to increase resistance in order to suppress current.   2. The current limiting interrupter according to claim 1, wherein the predetermined number of fixed contacts are arranged in a line on an arc having a predetermined radius.   The current limiting circuit breaker according to claim 1, wherein the predetermined number of fixed contacts are arranged in a straight line.   The series resistance value between the fixed contact at one end and the fixed contact at the other end by the resistance element is such that the current immediately before interruption is suppressed to 10 A or less. The current limiting circuit breaker described in 1.

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