JPH05114351A - Tripping device for circuit breaker - Google Patents

Abstract

PURPOSE:To easily make switch-over between under voltage tripping and voltage tripping in a same device by providing a DC power supply circuit the switch- over of which can be made between a regulation mechanism for trip spring force and the polarity of exciting current to a trip coil. CONSTITUTION:When a tripping device 1 is used as an under-voltage tripping, exciting current the polarity of which causes magnetic flux in the direction same to that of a permanent magnet 11, is supplied to a trip coil 10 from a DC power supply circuit 20, and when the magnetic flux of the coil 10 is weakened with current voltage lowered to one less than a specified value, the attraction of a stationary iron core 7 is thereby released by the force of a trip spring 15. And when the tripping device is used as voltage tripping, the attraction of an iron core 8 is released by sending exciting current the polarity of which weakens the magnetic flux of a magnet 11, to the coil 10 by a tripping command with the movable core 8 attracted onto the iron core 7 only by the magnetic flux of the magnet 11. Thus as mentioned herein above, the same device can be used to both systems only by making the switch-over of the polarity of the circuit 20 with respect to the coil 10 while being combined with the regulation of the spring 15 by means of a regulation mechanism 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trip device installed in a circuit breaker such as a circuit breaker for wiring, and more specifically, a trip device which can be used by switching between an undervoltage trip device and a voltage trip device. Regarding the device.

[0002]

2. Description of the Related Art There are various types of trip devices for tripping an opening / closing mechanism of a circuit breaker by an electromagnet action to open a movable contact. Among them, there are undervoltage trip devices and voltage trip devices. There is a removal device. As is well known, the undervoltage trip device is intended to trip the circuit breaker when the circuit voltage drops below the specified value.The voltage trip device electrically disconnects the circuit breaker from a distance. It is intended for tripping.

[0003]

By the way, the above-mentioned undervoltage trip device and voltage trip device are conventionally constructed as separate structures dedicated to their respective functions. Therefore, the circuit breaker in which the trip device of any one of the systems is incorporated cannot be switched to another system by the user, and the user has to reorder the circuit breaker. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a trip device for a circuit breaker which is convenient for the user as a structure in which the same trip device can be easily switched to both the voltage trip and the undervoltage trip. It is what

[0004]

In order to achieve the above object, the present invention provides a tripping device having a tripping coil and a permanent magnet on the outside of a fixed iron core and a movable iron core. A mechanism for adjusting the force and a DC power supply circuit capable of switching the polarity for supplying an exciting current to the trip coil based on a trip command are provided.

[0005]

When the trip device according to the present invention is used as an undervoltage trip device, the trip coil is supplied with an exciting current of a polarity that produces a magnetic flux in the same direction as the permanent magnet.
Release the adsorption of the fixed core when the circuit voltage drops below the specified value and the magnetic flux of the trip coil weakens. On the other hand, when used as a voltage trip, the movable iron core is attracted to the fixed iron core only by the magnetic flux of the permanent magnet, and when the trip command is issued, the trip coil has a polarity that weakens the magnetic flux of the permanent magnet. The exciting current is supplied from the DC power supply circuit to release the adsorption of the movable iron core. In this way, by switching the polarity of the DC power supply circuit with respect to the trip coil, both types are used.

Here, the attraction force when the trip spring separates the movable iron core from the fixed iron core is, in the case of undervoltage trip, the attraction force of the permanent magnet plus the coil magnetic flux based on the circuit voltage. In the case of voltage trip, the force of the coil magnetic flux becomes smaller than the attraction force of the permanent magnet by the amount of coil magnetic flux.Therefore, the force of the trip spring is changed by the adjusting mechanism, and the spring force in case of undervoltage trip is stronger than that in voltage trip. To do.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. Here, FIG. 1 is a longitudinal sectional view of a main part of a circuit breaker in which a trip device is incorporated, FIG. 2 is a plan view seen from the arrow P direction, and FIG. 3 is a connection diagram of a DC power supply circuit in FIG. 4 is an operating characteristic diagram. 1 and 2,
Reference numeral 1 denotes a tripping device which is unitized on a boat-shaped base 2 of a resin molded product, and is detachably mounted on an accessory base 3 of the resin molded product through an engaging leg 2a integral with the base 2. The accessory base 3 is detachably attached to the main body cover 4 of the circuit breaker via the integral engagement legs 3a. In the accessory base 3, instead of the illustrated trip device 1,
Other accessories such as auxiliary switches and alarm switches can be attached. The trip device 1 is covered with an auxiliary cover 5 which is attached to the body cover 4 so as to be openable and closable.

In the trip device 1, 6 is a U-shaped yoke held by the base 2, 7 is a cylindrical fixed iron core connected to the center, 8 is a cylindrical movable iron core facing the fixed iron core,
Reference numeral 9 is a non-magnetic cylinder that is fitted around the fixed iron core 7 and guides the movable iron core 8 in a slidable manner. 10 is a trip coil mounted on the outer side of the non-magnetic cylinder. A pair of permanent magnets arranged, 12 is a shunt fitted between the cylinder 6 and the permanent magnet 11, 13 is a yoke piece connecting between both legs of the yoke 6, 14 is the yoke 6,
It is a push rod that penetrates through the centers of the fixed iron core 7 and the movable iron core 8, slides freely with respect to the yoke 6 and the fixed iron core 7, and is integrally connected to the movable iron core 8.

Further, in FIG. 1 and FIG. 2, 15 is held between a circular spring push 16 and a rectangular spring receiver 17, and is arranged between the base end 14a of the push rod 14 and the base 2. A trip spring formed of a compression coil spring, 18 is an adjusting screw screwed into the base 2 so as to abut against the spring pusher 16, and 19 is a return spring formed of a compression coil spring inserted between the base 10 and the movable core 8. 20 is a DC power supply circuit for supplying an exciting current to the trip coil 10, 20a is its lead wire, 21 is a trip crossbar of a circuit breaker in which the arm 21a faces the tip of the push rod 14, and 22 is a latch of the circuit breaker. Shafts and 23 are bifurcated reset levers, which are resin-molded products and are connected to the latch shaft 22 via pieces 24 (FIG. 2).

As shown in FIG. 2, the spring receiver 17 has grooves (not shown) at both ends thereof loosely fitted to the ridges 2b on both sides of the base 2 so that the lateral movement of the drawing is guided. The piece 24 is fitted and coupled to a projection 22a formed on the end surface of the latch shaft 22 along the radial direction thereof from above through a corresponding groove (not shown). Further, the reset lever 23 is coupled to a ridge 24a formed on the end face of the piece 24 in the same manner as the ridge 22a via a corresponding groove (not shown). The other end of the reset lever 23 is rotatably supported in a receiving groove of a bearing stand 4a (FIG. 1) formed in the body cover 4.

The DC power supply circuit 20 is constructed as shown in FIG. In the figure, 25 is a rectifier circuit consisting of a diode bridge, 26 is a surge absorber connected to the power source side to protect electronic parts from surge voltage, 27
Is a protection resistor, 28 is a constant voltage diode, 29 is a resistor 27
A smoothing circuit and a capacitor 30 are connectors for switching the connection with the trip coil 10.
The DC power supply circuit 20 is connected to the operating circuit in the case of voltage trip, and is connected to the main circuit directly in case of undervoltage trip or via an appropriate transformer or voltage divider.

In the above structure, the circuit breaker is turned on and off.
In the FF state, the movable iron core 8 is the permanent magnet 1 indicated by the arrow in the figure.
In the case of trip of the magnetic flux of 1 and undervoltage trip, the magnetic flux of the trip coil 10 additionally applied thereto is attracted to the fixed iron core 7, and the trip spring 15 is compressed by the push rod 14 and is in a stored state. Here, when a trip command is given to the trip coil 10 via the DC power supply circuit 20, the attraction of the movable iron core 8 is released, and the push rod 14 is driven by the trip spring 15 to the right in the direction of the chain line in the figure. Then, the arm 21a of the trip crossbar 21 is pushed. As a result, the trip crossbar 21
Rotates counterclockwise as shown by the chain line, and the latch of the opening / closing mechanism (not shown) is unlocked to open the movable contact (not shown).

In the course of the trip operation, the latch shaft 22 that supports the latch rotates counterclockwise to move the latch shaft 22.
The reset lever 23 coupled to moves from the solid line position in the figure to the chain line position. The reset lever 23 pushes back the spring bearing 17 that has moved to the chain line position to compress the trip spring 15. Therefore, the push rod 14 has the return spring 1
It is pushed by 9 and moves to the left, and the movable iron core 8 is brought into contact with the fixed iron core 7. Therefore, if the conditions for attracting the movable iron core 8 are satisfied at that time, the trip device 1 is reset to the illustrated state again.

Next, the operation when the trip device 1 for performing the trip operation is used as an undervoltage trip device and when it is used as a voltage trip device will be described with reference to FIGS. 3 and 4. To do. Here, the vertical axis in FIG. 4 represents the spring force of the tripping spring 15 and the attraction force acting on the movable iron core 8 in the stored state, and the horizontal axis represents the voltage applied to the tripping coil 10. In the DC power supply circuit 20 in FIG. 3, the tripping coil 10 voltage Zener voltage Vz is subtracted from the voltage V _i of the output side of the rectifier circuit 25 a constant voltage diode 28 is applied. Therefore, when the voltage V _i is lower than Vz, no voltage is applied to the trip coil 10.

First, in the case of tripping undervoltage, the connector 30 is connected in such a manner that the direction of the magnetic flux of the trip coil 10 matches that of the permanent magnet 11. At that time, while the voltage V _i is equal to or lower than the Zener voltage Vz, the attraction force acting on the movable iron core 8 is a constant value only by F _M by the permanent magnet 11, and the voltage V _i
Becomes equal to or higher than Vz, the attraction force of the trip coil 10 due to the voltage difference therebetween is applied, and the overall result is as illustrated.
If this attraction force is larger than the force S _R of the trip spring 15, the movable iron core 8 is held in the attracted state, but if the circuit voltage decreases and the voltage V _i proportional to this decreases to, for example, V _R , the attraction force F _The spring force S _R is larger than _R and the tripping operation is performed.

On the other hand, in the case of voltage trip, the connector 30 is connected in such a relationship that the direction of the magnetic flux of the trip coil 10 is opposite to that of the permanent magnet 11. As a result, the voltage V
_{When i} exceeds Vz, the trip coil 10 has a permanent magnet 1
Magnetic flux is generated in a direction to weaken a magnetic flux, the suction force acting on the movable iron core 8 is smaller than F _M as indicated by the chain line in FIG. Therefore, the spring force at this time is set to S _A , which is smaller than the attraction force F _M, to adsorb the movable iron core 8 only by the permanent magnet 11, and the operating voltage V _A is applied as the voltage V _i during the tripping operation. Then, the suction force becomes smaller than the spring force S _A , and the tripping operation is performed. The spring force of the trip spring 15 is adjusted by the adjusting screw 18 (FIG. 1). The spring force becomes stronger as the adjusting screw 18 is tightened and the spring pusher 16 is pushed forward as shown by the chain line in FIGS. 1 and 2 and the trip spring 15 is compressed. If Mr. undervoltage release a larger spring force than the case of Mr. shunt trip (S _R> S _A).

[0017]

As described above, according to the present invention, the same tripping device is deficient only by switching the polarity of the DC power supply circuit to the tripping coil between normal and reverse and adjusting the spring force of the tripping spring. It can be used for both voltage tripping and voltage tripping, which not only makes it convenient for users, but also reduces the number of models on the manufacturer side and simplifies inventory management.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a diagram viewed from a direction of an arrow P in FIG.

FIG. 3 is a wiring diagram of the DC power supply circuit in FIG.

FIG. 4 is an operating characteristic diagram of the embodiment of the present invention.

[Explanation of reference numerals] 1 tripping device 7 fixed iron core 8 movable iron core 10 tripping coil 11 permanent magnet 15 tripping spring 18 adjusting screw 20 DC power supply circuit 21 trip crossbar

Claims (1)

[Claims] 1. A trip coil and a permanent magnet are provided outside a fixed iron core and a movable iron core, and the movable iron core is attracted to the fixed iron core to hold a trip spring in a stored state. When a trip command is given to the coil, the attraction of the movable core is released to cause the force of the trip spring to act on the opening / closing mechanism of the circuit breaker, and the trip device of the circuit breaker that opens and closes the movable contact, A mechanism to adjust the force of the trip spring,
A trip device for a circuit breaker, comprising: a DC power supply circuit capable of switching the polarity of supplying an exciting current to a trip coil based on a trip command.