JP4253702B2 - Circuit breaker - Google Patents

Description

  The present invention relates to a circuit breaker, and is particularly suitable for application to a circuit breaker switching mechanism of a four-pole four-element structure used in a three-phase four-wire circuit.

In a circuit breaker having a four-pole four-element structure used for a three-phase four-wire electric circuit, a neutral pole is provided at the end of the product. Here, the position of the neutral electrode can be arbitrarily determined by the manufacturer, and the neutral electrode may not be provided with an overcurrent trip device because of its function and cost.
On the other hand, the phase that becomes the neutral pole is selected at the right or left end of the product depending on the country or region, and if the position of the neutral pole does not match the host device, it is necessary to change the wiring each time. As a single unit, it is desirable to provide an overcurrent tripping device for all phases, and to use an inexpensive mechanical structure that allows the contractor to arbitrarily designate the position of the neutral electrode. Here, in a mechanical overcurrent tripping device, a structure is generally used in which an overcurrent signal is transmitted to the opening / closing mechanism using the bending of bimetal or the like.

Further, for example, in Patent Document 1, a latch receiver that latches a latch of an opening / closing mechanism and a trip bar that latches the latch receiver are configured by a common return spring composed of a tension coil spring, and the mounting thereof is simple. A method is disclosed.
Further, for example, Patent Document 2 discloses a method of eliminating the need for a pin for supporting a trip bar in a circuit breaker in which the trip bar is rotatably attached to a frame having side plates standing upright on the left and right. Yes.
Japanese Patent Laid-Open No. 10-40796 Japanese Patent Laid-Open No. 10-31951

  However, in a circuit breaker with a four-pole four-element structure used in a three-phase four-wire circuit, if a mechanical overcurrent trip device is provided in all phases of the circuit breaker device, it is separated from the switching mechanism. The overcurrent tripping device installed in the end phase at the position has a longer distance to the opening / closing mechanism than the overcurrent tripping device installed in the other phase. For this reason, the trip bar that is configured in the switching mechanism and cooperates with the overcurrent tripping device is subject to bending due to deformation during application of load or inclination due to shaft backlash, etc., and bending of bimetal etc. included in the overcurrent tripping device There is a problem that a loss occurs until the signal is transmitted to the opening / closing mechanism.

The trip bar not only transmits the overcurrent signal from the overcurrent trip device to the switching mechanism, but also has a signal transmission function to the attached accessory device. There is a problem that a loss also occurs in the cooperative operation with the accessory device due to the bending of the trip bar of the end phase where the is installed and the shaft backlash.
SUMMARY OF THE INVENTION An object of the present invention is to provide a circuit breaker that can reduce deflection and shaft play due to deformation of a trip bar when a load is applied.

To solve the problems described above, according to the circuit breaker according to claim 1, and four fixed contact which is fixed with a predetermined interval in the case, and a cover for closing the case, the four Four movable contacts that can be individually opened and closed with a stationary contact, a holder that holds the movable contacts and is supported so as to be rotatable via an opening and closing shaft, and can be operated by opening and closing the handle. An open / close mechanism that reverses the direction of action of the main spring by disengaging the latch and the latch receiver to perform an open / close operation between the movable contact and the fixed contact, and based on an overcurrent detection result Te, and four overcurrent tripping device for generating mechanical deflection due temperature-actuated or electromagnetic rotatably engaged canti both by a pin to the opening and closing mechanism, and the four overcurrent tripping rotation mechanical deflection generated by device By converting to be transmitted to the opening and closing mechanism, and a trip bar out of engagement with receiving the said latch latch, provided on the opening and closing mechanism and away coaxial of said pins of said trip bar A columnar auxiliary rotating shaft and a auxiliary bearing provided on the case or the cover and rotatably supporting the auxiliary rotating shaft have a four-pole four-element structure .

  As a result, when a load is applied to the trip bar, the auxiliary rotating shaft and auxiliary bearing provided on the trip bar come into contact with each other. It is possible to reduce the transmission loss between the overcurrent trip device and the opening / closing mechanism, and it is possible to increase the distance between the support of the trip bar, and the bending moment applied to the trip bar can be increased. Since it becomes possible to reduce, the bending by the deformation | transformation of a trip bar can be suppressed. For this reason, in a circuit breaker having a four-pole four-element structure used in a three-phase four-wire circuit, even when a mechanical overcurrent trip device is provided in all phases of the circuit breaker device, the switching mechanism And a circuit breaker with high safety that enables the contractor to arbitrarily place the neutral pole according to the host device. In addition to being able to be provided at a low cost, it is possible to improve the accuracy of the cooperative operation with the attached device using the trip bar, and to increase the variation of the attached device.

Further, according to the circuit breaker according to claim 2, wherein, prior Kiho aids bearing is provided at a position corresponding to the end portion of the trip bar of the casing or formed in the cover the interphase wall or end phase side It is characterized by.
As a result, even if the distance from the switching mechanism to the overcurrent trip device becomes longer because all phases of the circuit breaker equipment are equipped with mechanical overcurrent trip devices, the trip when applying a load is performed. It is possible to reduce the bending due to the deformation of the bar and the inclination due to shaft backlash and the like, and it is possible to stably perform the cooperative operation between the opening / closing mechanism and the overcurrent tripping device.

  As described above, according to the present invention, even when the distance from the switching mechanism portion to the overcurrent tripping device becomes long, the cooperative operation between the switching mechanism and the overcurrent tripping device is stabilized. Therefore, it is possible to provide a circuit breaker having a 4-pole 4-element structure in which an overcurrent tripping device is provided at the neutral pole on the right end or the left end at a low cost.

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a circuit breaker according to an embodiment of the present invention.
In FIG. 1, the circuit breaker includes a fixed contact 5 fixed to the case 1 and a movable contact 18 that can be opened and closed between the fixed contact 5, a movable contact 18 that holds the movable contact 18, and is rotated via an opening / closing shaft. A holder 23 that is movably supported is provided. In addition, a flexible lead wire 19 is connected to the rear end of the movable contact 18 by brazing, and the lead wire 19 is connected to a heater conductor 21 joined to the lead conductor 20 with a screw through a lead plate 20. Has been. And the heater conductor 21 is connected to the load side terminal 22 integral with the connection conductor brazed to this.

  Further, the circuit breaker is provided with an arc extinguishing chamber 4 for extinguishing an arc generated due to the opening / closing operation between the fixed contact 5 and the movable contact 18, and the bimetal 17, the heater conductor 21, An armature 24 and an electromagnet are incorporated, and an overcurrent trip device is provided that generates mechanical deflection by a thermal type or an electromagnetic type based on the detection result of the overcurrent.

  Further, the circuit breaker is provided with an opening / closing mechanism for performing an opening / closing operation between the movable contact 18 and the fixed contact 5, and the opening / closing mechanism is interlocked with the handle 6 for performing the opening / closing operation and the handle 6. The handle lever 7 that operates, the upper toggle 8 that constitutes the toggle link mechanism, the lower toggle 9 and the latch 10, the main spring 11 that urges the toggle link mechanism to an arbitrary position, and the latch 10 are engaged to support the toggle link mechanism. A side plate 14 for supporting the latch receiver 12 and the claw 13 and holding the toggle link mechanism is provided, and the pin 15 penetrating the pair of side plates 14 is rotatably engaged with both ends, and the overcurrent pulling is performed. A trip bar 16 is provided to disengage the latch 10 from the latch receiver 12 by transmitting the mechanical deflection generated by the releasing device to the opening / closing mechanism. That.

  Here, the upper toggle 8 and the lower toggle 9 are connected to each other via a toggle pin. The upper end of the upper toggle 8 is connected to the latch 10 so as to rotate freely, and the lower toggle 9 is connected to the holder 23. Further, a lower end hook portion of the main spring 11 constituted by a tension spring is hooked on the toggle pin, and an upper end hook portion of the main spring 11 is hooked on the upper end of the handle lever 7. The opening / closing mechanism reverses the direction of action of the main spring 11 by opening / closing the handle lever 7 to drive the holder 23 to open / close, and the latch 10 is unlocked to release the latch link 10 from the toggle link mechanism. The holder 23 can be trip-driven by reversing the action.

These components are housed in a container composed of a molded resin case 1, a middle cover 2 and a top cover 3.
In a state where the fixed contact 5 and the movable contact 18 are closed, a path of power source side → fixed contact 5 → movable contact 18 → lead wire 19 → lead plate 20 → heater conductor 21 → load side terminal 22 Current can flow through.

  When the current flowing through the heater conductor 21 of the overcurrent tripping device is overloaded, the bimetal 17 is bent counterclockwise by the heat generated from the heater conductor 21 and pushes the trip bar 16. When the trip bar 16 is pushed in, the latch 10 and the latch receiver 12 are disengaged via the tab 13 of the opening / closing mechanism, the toggle link mechanism is operated, and the holder 23 connected to the lower toggle 9 is rotated. The movable contact 18 is separated from the fixed contact 5 by being moved.

  Further, when a large current such as a short-circuit current flows through the heater conductor 21, the armature 24 of the overcurrent tripping device is instantaneously adsorbed counterclockwise and strikes the trip bar 16 at its tip. When the trip bar 16 is hit, the latch 10 and the latch receiver 12 are disengaged to operate the toggle link mechanism, and the holder 23 connected to the lower toggle 9 is rotated to fix the movable contact 18. The contact 5 is separated.

2 is a perspective view showing a schematic configuration of a trip bar and an opening / closing mechanism according to an embodiment of the present invention, and FIGS. 3 and 4 are examples of a schematic configuration of a trip bar and a case according to an embodiment of the present invention. It is a perspective view shown.
In FIG. 2, the trip bar 16 is engaged with an opening / closing mechanism so as to be rotatable at both ends by a pin 15 penetrating a pair of side plates 14. The trip bar 16 is provided with columnar auxiliary rotating shafts 25a and 25b at positions away from the coaxial opening / closing mechanism of the rotating shaft of the trip bar 16. Here, the auxiliary rotating shaft 25 a is disposed at the end portion of the trip bar 16 on the end phase side, and the auxiliary rotating shaft 25 b is disposed at a position corresponding to the interphase wall formed in the case 1.

  In FIG. 3, the case 1 is provided with an overcurrent tripping device for all phases, and an auxiliary bearing 26 a that rotatably supports the auxiliary rotating shaft 25 a is provided on the side wall of the case 1. Here, the auxiliary bearing 26a is disposed at a position corresponding to the end portion of the trip bar 16 on the end phase side, and can have a U-shaped groove shape so that the auxiliary rotating shaft 25a can be fitted.

  In addition to the embodiment of FIG. 3, in FIG. 4, the case 1 is formed with a phase interval wall 30 that partitions the case 1 for each phase, and the auxiliary rotation shaft 25 b can be rotated only on the phase interval wall 30. A supporting auxiliary bearing 26b may be provided. Here, the auxiliary bearing 26b can have a U-shaped groove shape so that the auxiliary rotating shaft 25b can be fitted. Further, the auxiliary rotation shaft 25a of the trip bar 16 may be omitted.

  When an overcurrent flows through the heater conductor 21 of the overcurrent tripping device and the bimetal 17 or the armature 24 operates, a load is applied to the trip bar 16 via the bimetal 17 or the armature 24. Here, when a load is applied to the trip bar 16, the auxiliary rotary shafts 25a and 25b provided on the trip bar 16 and the auxiliary bearings 26a and 26b come into contact with each other, whereby the side plate 14, the pin 15 and the trip bar are contacted. The loss in the escape direction 27 due to the shaft backlash generated by each of the 16 component dimensions is converted into a force in the rotational direction 28.

  For this reason, it is possible to reduce transmission loss between the overcurrent trip device and the opening / closing mechanism, and it is possible to increase the distance between the support of the trip bar 16, and the bending moment 29 applied to the trip bar 16 is increased. The bending due to the deformation of the trip bar 16 can be suppressed. As a result, in a circuit breaker having a four-pole four-element structure used for a three-phase four-wire circuit, even when a mechanical overcurrent trip device is provided in all phases of the circuit breaker device, the switching mechanism And a circuit breaker with high safety that enables the contractor to arbitrarily place the neutral pole according to the host device. In addition to being able to be provided at low cost, it is possible to improve the accuracy of the cooperative operation with the attached device using the trip bar 16, and to increase the number of variations of the attached device.

  In the above-described embodiment, the method of providing the case 1 with the auxiliary bearings 26a and 26b that rotatably support the auxiliary rotating shafts 25a and 25b has been described. However, the component that positions the opening / closing mechanism is the middle cover 2 or When the top cover 3 is used, auxiliary bearings 26 a and 26 b may be provided on the middle cover 2 or the top cover 3.

It is sectional drawing which shows schematic structure of the circuit breaker which concerns on one Embodiment of this invention. It is a perspective view which shows schematic structure of the trip bar and opening / closing mechanism which concerns on one Embodiment of this invention. It is a perspective view which shows an example of schematic structure of the trip bar and case which concern on one Embodiment of this invention. It is a perspective view which shows the other example of schematic structure of the trip bar and case which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Middle cover 3 Top cover 4 Arc extinguishing chamber 5 Fixed contact 6 Handle 7 Handle lever 8 Upper toggle 9 Lower toggle 10 Latch 11 Main spring 12 Latch receiver 13 Claw 14 Side plate 15 Pin 16 Trip bar 17 Bimetal 18 Movable contact Child 19 Lead wire 20 Lead plate 21 Heater conductor 22 Load side terminal 23 Holder 24 Armature 25a, 25b Auxiliary rotating shaft 26a, 26b Auxiliary bearing 27 Escape direction 28 Rotating direction 29 Bending moment 30 Phase spacing wall

Claims (2)

Four fixed contacts fixed to the case at predetermined intervals ;
A cover for closing the case;
Four movable contacts that can be individually opened and closed with the four fixed contacts;
A holder that holds the movable contact and is rotatably supported via an opening and closing shaft;
An opening / closing mechanism that is operable by opening / closing the handle, reverses the acting direction of the main spring by disengaging the latch and the latch receiver, and performs an opening / closing operation between the movable contact and the fixed contact; ,
Four overcurrent tripping devices that generate mechanical deflection by thermal or electromagnetic type based on the detection result of the overcurrent;
By engaging the opening / closing mechanism with a pin so as to be rotatable with both pins , converting the mechanical deflection generated by the four overcurrent tripping devices into a rotational force and transmitting it to the opening / closing mechanism, A trip bar for disengaging the latch and the latch receiver;
A cylindrical auxiliary rotating shaft provided at a position away from the opening and closing mechanism on the same axis of the pin of the trip bar;
A circuit breaker having a 4-pole 4-element structure with an auxiliary bearing provided on the case or the cover and rotatably supporting the auxiliary rotating shaft. Before Kiho aid bearings, circuit breaker according to claim 1, characterized in that provided at a position corresponding to the end of the trip bar of the case or interphase walls formed on the cover or the end phase side vessel.

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