KR100585861B1 - Shutting device in circuit breaker - Google Patents

Abstract

The present invention relates to a current-limiting device for a circuit breaker, comprising a current-limiting power-type contactor that is bent into a U-shape connected to a power-side circuit, a current-limiting load-side stationary contactor bent into a U-shape to be connected to a load-side circuit, and a power-side and load-side fixing device. A rotation having a movable contact rotatably disposed to simultaneously contact or disconnect the contacts, and an opening for rotatably supporting the movable contact and allowing independent rotation of the movable contact with respect to the rotor shaft by electromagnetic repulsion; A first pin and a second pin symmetrically disposed about the center axis of the movable contactor to be in contact with the magnetic axis, the upper and lower outer peripheral surfaces of the movable contactor, and slidable on the upper and lower outer peripheral surfaces of the movable contactor respectively, and one end thereof; Support the first pin or the second pin and the other end of the rotor shaft; It is installed to support the spring support protrusion protruding from the surface, and includes four contact springs, one pair per one side of the rotor shaft to provide a contact pressure to maintain contact during contact between the movable contactor and the power supply side and the load-side fixed contactor Wherein the movable contact has a contact seating groove having a predetermined depth in which the first pin and the second pin rest upon contacting the power supply side and the load side fixed contactor, and the movable contactor is moved to the power supply side and the load side by electromagnetic repulsion. The separation seating groove having a predetermined depth deeper than the predetermined depth so that the first pin and the second pin are seated so as to prevent the movable contact from returning to the power side and the load side fixed contact when rotated from the fixed contact. On the outer circumferential surface thereof, the movable contactor rotates in an abnormal current state. When the contact between the movable contact and the power supply side and the load-side fixed contact is released, the pin is inserted into the separation seating groove, the rotational state of the movable contact is fixed by the elastic force of the contact spring between the pin and the spring support protrusion Thus, the fixed contactor does not return to the fixed contactor for a certain period of time after the movable contactor repels due to the electromagnetic repulsion force generated between the movable contactor and the fixed contactor when an accident current such as a short circuit current flows into the distribution circuit. A current limiting device for a circuit breaker for maintaining a state separated from the present invention is provided.

Circuit breaker, current-limiting device, mover, contact spring, stator pin

Description

Current limiting device for wiring breakers {SHUTTING DEVICE IN CIRCUIT BREAKER}

1 to 3 is a view showing the configuration of a current-limiting device of a conventional circuit breaker,

Figure 1 is a side cross-sectional view showing the configuration of a conventional circuit breaker

Fig. 2 is a side sectional view showing the construction of the current-limiting device of Fig. 1;

3 is a side cross-sectional view showing the operating principle of the current-limiting device of FIG.

4 to 8 is a view showing the configuration of a current-limiting device of a circuit breaker according to an embodiment of the present invention,

Figure 4 is a side cross-sectional view showing the configuration of a current-limiting device of a circuit breaker according to an embodiment of the present invention

5 is a perspective view showing the configuration of the current-limiting device of FIG.

6 is an exploded perspective view showing the configuration of the current-limiting device of FIG.

7 is a side view showing a pre-operational state of the current-limiting device of FIG.

8 is a side view showing a state after the operation of the current-limiting device of FIG.

** Description of symbols for the main parts of the drawing **

110: breaker cover 120: breaker case

130: current-limiting devices 131a, 131b: stator

131d, 131e: stator contact 132: mover

132d, 132e: mover contact 133: rotor shaft

134: pressure spring 135: movable pin

140: trip mechanism 150: arc extinguishing unit

The present invention relates to a current-limiting device for a circuit breaker, and more particularly, when the movable contactor repulses from the fixed contactor by an electromagnetic repulsion force generated between the mover and the stator when an accident current such as a short circuit current flows in the distribution circuit. The present invention relates to a current-limiting device for a circuit breaker having a configuration in which the movable contactor returns to the stationary contactor for a predetermined time and is kept in contact with each other without being contacted.

In general, a circuit breaker is an electrical device that protects a circuit and a load by automatically cutting off a circuit in the event of an electrical overload or a short circuit. The circuit breaker is largely connected to the power supply side and the load side, the switch unit which opens and closes the fixed contactor and the movable contactor in the circuit breaker so as to be in contact with or separated from each other, and when an overcurrent, instantaneous current, or short-circuit current occurs in the circuit of the power supply and the load. It consists of a trip part that detects and induces a trip to cut off power to the opening and closing mechanism part.

On the other hand, when an abnormal current such as overcurrent, instantaneous current, short circuit current, etc. occurs, the circuit breaker recognizes this and automatically cuts off the current regardless of artificial opening and closing. This operation is called a trip. Then, when the current applied to the circuit breaker is instantaneously applied at a constant magnification of the rated current, it is called an instant trip to sense this and trip it at an appropriate time.

In order to examine this in more detail, it will be described with reference to the accompanying drawings.

1 to 3 are views showing the configuration of the current-limiting device of the conventional circuit breaker, FIG. 1 is a side cross-sectional view showing the configuration of a conventional circuit breaker, and FIG. 2 is a side sectional view showing the configuration of the current-limiting device of FIG. 3 is a side cross-sectional view showing the operating principle of the current-limiting device of FIG.

As shown in the drawing, the conventional circuit breaker 1 includes a circuit breaker case 20 for accommodating parts, a circuit breaker cover 10 for covering an upper portion of the circuit breaker case 20, and a converter. Current-limiting device (30) consisting of an opening and closing mechanism to turn ON / OFF, trip unit 40 for detecting an abnormal current and an accident current, stator contacts (31d, 31e) and mover contacts when disconnected And an arc extinguishing section 50 for extinguishing the arc Arc generated between 32d and 32e.

Here, the current-limiting device 30 generally refers to a structure for limiting the accident current by the electromagnetic repulsive force in the circuit breaker. That is, as shown in FIG. 2, the current-limiting device 30 includes stators 31a and 31b having stator contacts 31e and 31d, one end of which is fixed to the main circuit and formed to contact the mover, and a mechanism part. The mover 32 and the mover 32 having the mover contacts 32e and 32d formed to rotate about an axis according to ON / OFF and to contact / disengage with the contacts 31e and 31d of the stator in rotation. A contact spring formed of a torsional spring to maintain contact pressure when the rotor shaft 33 and the mover 32 and the stator 31a, 31b come into contact with each other while the wrapper rotates according to the on / off of the mechanism ( 34), a movable pin (35) connecting the contact spring (34), the mover (32) and the rotor shaft (33), and a contact spring pin (36) supporting one side of the contact spring (34). It is composed.

At this time, the stator 31a is connected to the power supply side terminal portion, and another stator 31b is connected to the load side terminal portion.

The operation of the current-limiting device 30 of the conventional circuit breaker 1 configured as described above is as follows. That is, when a short circuit fault current flows in the main circuit part of the circuit breaker 1 including the stators 31a and 31b, the mover 32, and the terminal portion, as shown in FIG. 3, the mover 32 and the stator ( Between 31a and 31b), an electromagnetic repulsion force indicated by the reference numeral Fe and an arc are generated to push up the mover 32, which causes the circuit to be cut off in the event of an accident current such as a short circuit current flowing between the mover and the stator. To protect the circuit and the load.

However, the current flowing by the voltage of the arc generated when the short-circuit fault current flows decreases, and as the current decreases, the electron repelling force Fe also decreases. At some point, the electromagnetic repulsive force Fe is less than the contact pressure Fs by the contact spring 34 of the mover 32, causing the mover 32 to fall back and stator 31a and 31b. As shown in FIG. 2, the stator contacts 31d and 31e and the mover contacts 32d and 32e come into contact with each other. That is, the mechanism of the circuit breaker after the movable member 32 repulses by relying on the non-contact state of the contacts 31e, 31d, 32e, and 32d by the elastic restoring force of the torsion spring with low reliability in terms of maintaining the elastic restoring force. Since the movable part 32 and the stator 31a and 31b come into contact again before the operation, the break time is long to cut off the short-circuit accident current, thereby causing a structural problem in which failure of the break and fusion of the contact may occur. There was this.

The present invention has been made to solve the problems of the prior art as described above, the opening and closing portion is tripped by the electromagnetic repulsive force generated between the movable contactor and the current-limiting fixed contact when an accident current such as short circuit current flows in the distribution circuit. Even if not in a state of repulsion, the movable contactor is separated from the fixed contactor and rotates, and the movable contactor returns to the fixed contactor for a certain period of time, and the current-limiting structure and the contact structure can be kept separate from the fixed contactor without contact. It is an object of the present invention to provide a current-limiting device for a circuit breaker.

Further, another object of the present invention is to provide a current-limiting device of a circuit breaker for maintaining a balance of contact pressure and contact between the front and rear contacts.

The object of the present invention as described above is a circuit breaker,

A current-type power supply side fixed contactor bent into a U-shape connected to the power supply circuit;

A current-limiting load-side fixed contactor bent into a U-shape to connect to the load-side circuit;

A movable contactor rotatably disposed to simultaneously contact or disconnect the power supply side and the load side fixed contacts;

A rotor shaft rotatably supporting the movable contactor and having an opening for allowing independent rotation of the movable contactor with respect to the rotor shaft by electromagnetic repulsive force;

 First and second pins symmetrically installed with respect to the upper and lower outer circumferential surfaces of the movable contactor and slidable on the upper and lower outer circumferential surfaces of the movable contactor, respectively;

One end is supported on the first pin or the second pin, and the other end is installed to support the spring support protrusion protruding from the side of the rotor shaft, and to maintain contact when the movable contactor is in contact with the power supply side and the load side fixed contactor. Four contact springs, one pair per side of the rotor shaft providing contact pressure;

Wherein the movable contact includes a contact seating groove having a predetermined depth on which the first pin and the second pin rest upon contact with the power supply side and the load side fixed contactor;

When the movable contact is separated and rotated from the power supply side and the load side fixed contact by the electromagnetic repulsive force, the first pin and the second pin are seated so that the movable contact is prevented from returning to the power supply side and the load side fixed contact. It can be achieved by providing a current-limiting device for a circuit breaker according to the present invention, characterized in that the outer peripheral surface is provided with a separating seating groove having another predetermined depth deeper than the predetermined depth.

And, the contact spring is preferably formed of a tension spring. This is because the reliability of the operation is high due to less dispersion of the modulus of elasticity according to the fabricated lot, compared to the torsion spring.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, in describing the present invention, a detailed description of known functions or configurations will be omitted to clarify the gist of the present invention. In addition, the same code | symbol is attached | subjected about the same and same substantial part as the structure mentioned above, and the detailed description is abbreviate | omitted.

4 to 8 are views showing the configuration of the current-limiting device of the circuit breaker according to an embodiment of the present invention, Figure 4 is a side cross-sectional view showing the configuration of the current-limiting device of the circuit breaker according to an embodiment of the present invention; Figure 5 is a perspective view showing the configuration of the current-limiting device of Figure 4, Figure 6 is an exploded perspective view showing the configuration of the current-limiting device of Figure 5, Figure 7 is a side view showing a pre-operation state of the current-limiting device of Figure 5, Figure 8 5 is a side view showing a state after the operation of the current-limiting device of FIG.

As shown in the figure, the current-limiting device 130 of the circuit breaker according to an embodiment of the present invention includes a current-type power-side fixed contactor 131a bent in a U-shape to connect to a power-side circuit; A current-limiting load-side fixed contactor 131b bent into a U-shape connected to the load-side circuit; A movable contactor 132 rotatably disposed to simultaneously contact or disconnect the power supply side and the load side fixed contactors 131a and 131b; An opening for rotatably supporting the movable contactor 132 and allowing independent rotation of the movable contactor 132 with respect to the rotor shaft 133 by electromagnetic repulsive force (unsigned but open inward from the outer circumferential surface of the rotor shaft). A rotor shaft 133 having both ends of the movable contact protruding through the opening and having the movable contact rotatable regardless of the rotor shaft by the electromagnetic repulsive force; First and second pins symmetrically installed with respect to the central axis of the movable contactor 132 to contact the upper and lower outer peripheral surfaces of the movable contactor 132, and slidable on the upper and lower outer peripheral surfaces of the movable contactor 132, respectively; 135 and 135;

One end is supported to the first pin or the second (135) (135) pin and the other end is installed to support the spring support protrusion 133b protruding from the side of the rotor shaft 133, the movable contact 132 and Four contact springs (134), one pair per side of the rotor shaft (133), which provides contact pressure to maintain contact upon contact between the power supply side and the load side fixed contactors (131a) (131b);

Here, the movable contactor 132 includes a contact seating recess 132c having a predetermined depth in which the first pin and the second pin rest when contacting the power supply side and the load side fixed contactor 131a and 131b;

When the movable contactor 132 is separated from the power supply side and the load side fixed contactors 131a and 131b by the electromagnetic repulsive force and rotates, the first and second pins 135 and 135 are seated and the movable contactor 132 is seated. In order to prevent the return to the power supply side and the load side fixed contactors 131a and 131b, a separation seating groove 132a having a predetermined depth deeper than the predetermined depth is provided on the outer peripheral surface thereof.

A pair of pin installation grooves 133a are formed on the outer circumferential surface of the rotor shaft 133 and include a hinge shaft 139 for rotating the movable contactor 132 through the center of the rotor shaft 133. It is configured by. The movable contactor 132 is provided with a center hole through which the hinge shaft 139 penetrates, and the position thereof is formed as a long hole in a direction perpendicular to the longitudinal direction as the longitudinal and widthwise center points of the movable contactor. ) Can flow in accordance with the flow of the hinge shaft 139 in the long hole.

The contact spring 134 is installed with a predetermined tension amount as a coil tension spring. The contact spring 134 is composed of a tension spring because the dispersion coefficient of the elastic spring is less than the torsion spring used in the prior art and the operation reliability is high, and the contact spring 134 has a predetermined amount of tension. It is installed to have a pin 135 so that a constant elastic force acts toward the center of the rotor shaft 133.

The first and second pins 135 and 135 have a length extending to the outer circumferential surface of the rotor shaft 133, and both ends and spring support protrusions 133b of the first and second pins 135 and 135. In order to protect the contact spring 134 supported by the arc from the arc, the rotor shaft 133 is formed on both sides of the concave concave surface to form a spring evacuation concave surface for accommodating the contact spring therein.

Hereinafter, the operating principle of one embodiment of the present invention will be described in detail.

In the general energized state, the first and second pins 135 and 135 are seated in the contact seating grooves 132c respectively formed on the upper and lower outer peripheral surfaces of the movable contactor 132, and at the same time on the outer peripheral surface of the rotor shaft 133. It will be in a state seated in the pair of pin installation groove (133a) formed in.

The pressing force in the direction of the center of rotation of the rotor shaft 133 is applied to the first pin and the second pin 135, 135 by the contact spring 134. Accordingly, the movable contactor 132 and the fixed contactor 131a and 131b are in contact with each other while maintaining a constant contact pressure. At this time, the curved area 132b of the mover 132 allows the mover 132 to transmit a constant force to both of the stators 131a and 131b.

In the state in which the short-circuit accident current occurs, electromagnetic repelling force Fe is generated between the movable contactor 132 and the fixed contactors 131a and 131b, and the movable contactor 132 is fixed contactors 131a and 131b by this electromagnetic repulsive force. ) Rotates separately, and an arc occurs between the contacts (131d, 131e, 132d, 132e). However, unlike the current limiting device of the conventional circuit breaker, when the movable contactor 132 is rotated by repulsion, the first and second pins 135 and 135 rotate while sliding on the outer circumferential surface of the movable contactor 132. Along the pin installation groove 133a of the magnetic shaft 133, it is lifted outward of the pin installation groove 133a, and when the movable contactor 132 rotates more, the first pin and the second pin 135, 135 are moved. It is seated in the separation seating groove (132a). At this time, the movable contactor 132 is fixed, and the movable contactor 132 is kept in a separated state without contacting the fixed contactors 131a and 131b again while the opening / closing mechanism is tripped.

Therefore, in the current-limiting device 130 as described above, when a short-circuit accident current occurs, the movable contactor 132 is separated from the fixed contactors 131a and 131b by the electromagnetic repulsive force Fe of the accident current before the switching mechanism is operated. Rotating and holding the switch mechanism until the trip operation to prevent accidents such as re-ignition of the arc and fusion of the contacts (131d, 131e, 132d, 132e), failure of short-circuit blocking due to the contact of the movable contactor 132 again. do.

In addition, since the contact spring 134 of the mover is wrapped by the rotor shaft 133, when the accident current occurs, the contact spring 134 is not directly exposed to the arc, thereby preventing a decrease in contact pressure after a short circuit due to thermal stress.

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims.

As described above, according to the present invention, when an accident current such as a short circuit current flows in the power distribution circuit, the state in which the movable contactor reacts by the electromagnetic repulsion force generated between the movable contactor and the fixed contactant is maintained for a predetermined time. A current limiting device for a circuit breaker can be provided.

In addition, due to the arc generated when the movable contactor and the fixed contactor are separated, the contact spring of the movable contactor is not directly exposed to the arc heat, thereby ensuring horizontal improvement of the product and reliability of operation.

In addition, the contact reliability is improved by using a tension spring instead of using a torsion spring as a contact spring for maintaining the contact state between the movable contactor and the fixed contactor. It is possible to shorten the breaking time of the short circuit fault current and increase the breaking capacity of the wiring breaker by continuously disconnecting the mover from the stator even after the momentary reaction force is generated.

Claims (3)

In the circuit breaker for wiring, A current-type power supply side fixed contactor bent into a U-shape connected to the power supply circuit; A current-limiting load-side fixed contactor bent into a U-shape to connect to the load-side circuit; A movable contactor rotatably disposed to simultaneously contact or disconnect the power supply side and the load side fixed contacts; A rotor shaft rotatably supporting the movable contactor and having an opening for allowing independent rotation of the movable contactor with respect to the rotor shaft by electromagnetic repulsive force;  First and second pins symmetrically installed with respect to the upper and lower outer circumferential surfaces of the movable contactor and slidable on the upper and lower outer circumferential surfaces of the movable contactor, respectively; One end is supported on the first pin or the second pin, and the other end is installed to support the spring support protrusion protruding from the side of the rotor shaft, and to maintain contact when the movable contactor is in contact with the power supply side and the load side fixed contactor. Four contact springs, one pair per side of the rotor shaft providing contact pressure; Wherein the movable contact includes a contact seating groove having a predetermined depth on which the first pin and the second pin rest upon contact with the power supply side and the load side fixed contactor; When the movable contact is separated and rotated from the power supply side and the load side fixed contactor by electromagnetic repulsion, the first pin and the second pin are seated so that the movable contact is prevented from returning to the power supply side and the load side fixed contactor. A current-limiting device for a circuit breaker, characterized in that a separation seating groove having a predetermined depth deeper than the predetermined depth is provided on the outer circumferential surface thereof. The method of claim 1, The first and second pins have a length extending to an outer circumferential surface of the rotor shaft; In order to protect the contact springs supported by both ends of the first and second pins and the spring support protrusion from the arc, the rotor shaft has a spring having both sides thereof as a concave indentation to receive the contact spring therein. A current limiting device for a circuit breaker comprising an evacuation recessed surface. The method of claim 1, The contact spring is a current-limiting device of the circuit breaker, characterized in that consisting of a tension spring.

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