KR200190795Y1 - Limiting current device of a circuit breaker - Google Patents

Abstract

The present invention is to improve the movable contact support structure of the circuit breaker to prevent the departure of the movable contact, and to allow the current-limiting operation to be made accurately with a minimum of parts.

To this end, the present invention is installed to rotate in conjunction with the opening and closing mechanism 12 during the operation of the opening and closing handle (1) and the main shaft (2) having a structure having both side plates (2a), and the main shaft (2) Main pins (3) installed to penetrate the central portion of both side plates (2a), spring pins (5) installed to penetrate one side edge of both plates (2a) of the main shaft (2), and the main pins (3). Is a symmetrical structure that is coupled on the axis and rotates the main pins when the contacts are opened and has contacts on both sides, and a fixing groove 4a is formed on one side thereof, and is almost point-symmetrical about the main groove with respect to the fixing groove. In the position to form a movable contact (4) formed with a cam groove (7) to be held by the spring pin (5) to maintain the state opened from the fixed contact (9) during rotation by the electromagnetic repulsive force, and the outer peripheral surface of the main pin While winding one end is formed on one side of the movable contact Provided is a current-limiting device for a circuit breaker provided with an elastic member which is caught inside the groove and the other end is caught outside the spring pin 5 passing through both side walls of the main shaft and subjected to torsion upon opening of the contact by electromagnetic repulsive force. do.

Description

Current limiting device of circuit breaker

The present invention relates to a circuit breaker, and more particularly to an improvement in the structure of the current limiting device of the circuit breaker.

In general, wiring breakers are mainly installed in switchboards such as factories, bills, etc., and act as a switchgear that supplies or cuts power to the load side under no-load state. When a large current exceeding the load current flows in order to protect the electric wires of the converter and the load-side equipment, it serves as a circuit breaker that supplies or cuts off the power supplied from the power supply to the load.

Such wiring breakers are manufactured in various structures due to different frame sizes, number of poles, operation methods, etc. However, the mold case 10, the contactor, the trip device 11, the opening and closing mechanism 12, and the protection device are manufactured. (13) and the terminal 14 are comprised as a basic element.

Here, the mold case 10 is composed of a case and a cover formed of an insulating material to form a space for mounting each part, and when the parts are mounted inside the case, the mold case is insulated from each other as well as insulation from outside and invasion of foreign matter. It will serve to prevent.

In addition, the contactor is composed of a movable contactor 4 and a fixed contactor 9, and is provided for each pole to open and close the converter.

The trip device 11 detects an overcurrent or short-circuit current to operate the switchgear 12 to trip the circuit breaker, and the switchgear 12 is automatically cut off by the operation of the trip device 11. Alternatively, the movable contactor 4 is driven by manual operation of the opening and closing handle 1 to perform the opening and closing operation.

On the other hand, the extinguishing device 13 serves to protect the contacts and internal devices by quickly extinguishing the arc generated when the movable contactor 4 and the fixed contactor 9 are opened, and the terminal 14 is connected to the power supply side and the load side. It is connected to each pole and serves to connect external wires and internal conductors.

The conventional circuit breaker configured as described above prevents breakage or fire of the wiring and the connected equipment by quickly disconnecting the circuit when an abnormality occurs in the circuit, and the operating characteristics of the circuit breaker for demonstration are trial trip, pure seat lip, short time It is divided into three types of trip.

The operation characteristics of the circuit breaker described above will be briefly described as follows.

First of all, the demonstration trip will cause a fire if the electric wire is heated and left unattended if more than 125% of the rated current continuously flows for a certain time. Therefore, the circuit breaker shuts down the circuit before the temperature of the electric wire reaches a dangerous level. Say that.

In addition, the forward seat lip refers to interrupting the fault current by tripping the circuit breaker at the moment when a large fault current occurs momentarily due to a load line or a load abnormality.

On the other hand, in case of an accidental current occurring in a branch circuit close to the load side in a system in which a trunk circuit breaker and a branch circuit breaker are installed in series, the single circuit break trips before the circuit breaker for trunk wiring. This delays the time that the circuit breaker for tripping trips, and this characteristic can be said to be a characteristic only for a wiring breaker capable of adjusting the net trip value.

As shown in FIG. 2A, the current limiting device of the circuit breaker is connected to a pair of tension springs 15a and 15b in which the movable contactor 4 is symmetrically disposed with respect to the rotation shaft 17 of the main shaft 2. It is fixed to the main shaft (2), one end of the tension spring (15a, 15b) is fixed to the movable contactor 4, the other end is fixed to the main shaft (2), the movable contactor (4) And the contact pressure are maintained between the fixed contact 9 and the fixed contact 9.

One end of the tension springs 15a and 15b is fixed at both ends of the upper side of the movable contact 4 and the lower side of the main shaft 2, and the other end of the tension springs is connected to the main shaft 2. It is fixed to the upper side of the and the lower side of the movable contact (4).

The current limiting device of the conventional circuit breaker configured as described above allows current to flow through the movable contactor 4 through the power supply side fixed contactor 9 on the left side to the right load side fixed contactor 9 as shown in FIG. 2A during normal energization. do.

On the other hand, when an abnormal current is generated, as shown in FIG. 2B, the movable contactor 4 is pushed out of the fixed contactor 9 on both sides by the electromagnetic repulsive force between the contacts 4b and 9b, thereby causing the rotational moment. The contactor 4 overcomes the restoring force of the spring and rotates clockwise in the drawing so that the end of the load-side movable contactor 4 moves to the position of the stopper 18, and finally the cam groove 7 of the movable contactor 4 By being coupled with the holding pin 16 of the main shaft 2, the movable contact 4 is held in the lifted state (off state), thereby blocking the current.

However, such a current-limiting device of the circuit breaker of the related art cannot be made to match the rotation center of the movable contactor 4 and the rotation center of the main shaft 2 due to its structural characteristics.

That is, in order for the cam groove 7 to be caught by the holding pin 16 when the movable contactor 4 rotates due to the electromagnetic repulsive force between the contacts 4b and 9b, the tension springs 15a and 15b are The rotation shaft 17 of the main shaft should move to a position where the rotation shaft 17 of the main shaft 2 passes through the center of the movable contactor 4 so that the rotation shaft 17 of the main shaft 2 is moved. When passing through the center of the movable contactor 4, the tension springs 15a and 15b at the opening of the contacts 4b and 9b collide with the rotating shaft 17 passing through the center of the movable contactor 4 to move the movable contactor 4 ) Can no longer be rotated, the cam groove 7 is not caught by the holding pin 16 and the movable contact 4 cannot be held.

Therefore, in the related art, due to its structural characteristics, the rotary shaft 17 penetrating the center of the movable contactor 4 has not been provided. As a result, the rotational center of the movable contactor 4 is not constant when opening the contacts 4b and 9b. And the left and right sides of the movable contactor 4 and the forward and rearward flow of the movable contactor 4 are changed, so that the contact surface between the contact 9b of both fixed contactors 9 and the contact 4b of the movable contactor 4 is constantly changed. In addition, there are many problems such that the cam groove 7 of the movable contact 4 is not caught by the holding pin 16, which makes it difficult to perform a certain current-limiting operation.

The present invention is to solve the above problems, improve the movable contact support structure of the circuit breaker to prevent the departure of the movable contact, while the current-limiting device of the circuit breaker to ensure the current-limit operation with a minimum of parts The purpose is to provide.

1 is a cross-sectional view showing a conventional circuit breaker configuration

2A and 2B are cross-sectional views showing the configuration and operating state of the current-limiting device of FIG.

2A is a cross-sectional view showing a state in which contacts are connected when energized

Figure 2b is a cross-sectional view showing a state in which the contact is opened by the current-limiting action

3a and 3b is a cross-sectional view showing the configuration and operation of the current-limiting device of the present invention,

3A is a cross-sectional view showing a state in which contacts are connected when energized

Figure 3b is a cross-sectional view showing a state in which the contact is opened by the current-limiting action

Explanation of symbols for main parts of the drawings

1: Handle for opening and closing 2: Main shaft

2a: Both side plates 3: Main pin

4: movable contact 4a: fixed groove

4b: Contact point of movable contact 5: Spring pin

6: torsion spring 7: cam home

8: Guide Home 9: Fixed Contact

In order to achieve the above object, the present invention is installed to rotate in conjunction with the opening and closing mechanism when operating the handle for opening and closing the main shaft having a structure having both side plates, the main portion is installed to penetrate both sides of the central portion of the main shaft A symmetrical structure having a pin, a spring pin installed to penetrate through one side of the edge of both side plates of the main shaft, and a symmetrical structure coupled to the main pin to rotate the main pin axially when opening a contact and having contacts on both sides, respectively. A movable groove having a cam groove formed at a fixed groove in the cam groove, the cam groove being held at a spring pin during rotation by an electromagnetic repulsive force to maintain an open position from the fixed contact at a position that is substantially point symmetrical about the main pin with respect to the fixed groove; While wound on the outer circumferential surface of the main pin, one end is caught inside the fixing groove formed on one side of the movable contact and Provided is a current limiting device for a circuit breaker, characterized in that the stage is provided to be caught outside the spring pins penetrating both side walls of the main shaft, the elastic member receives a torsion upon opening of the contact by the electromagnetic repulsive force.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 3A and 3B.

Figure 3a, Figure 3b is a cross-sectional view showing the configuration and operating state of the current-limiting device of the present invention, Figure 3a is a cross-sectional view showing a state in which the contact is connected when energized, Figure 3b is a cross-sectional view showing a state in which the contact is opened by the current-limiting action to be.

In the present invention, the main pin (3) is installed so as to penetrate the central portion of both side plates (2a) of the main shaft (2) which is installed to rotate in conjunction with the opening and closing mechanism (12) when operating the handle 1 for opening and closing, the main On the pin 3, a movable contact 4 which is rotated about the main pin 3 as the axis when the contacts 4b and 9b is opened is engaged.

In addition, a spring pin 5 is installed at one edge of both side plates 2a of the main shaft 2.

In addition, one end of the torsion spring 6, which is an elastic member installed to surround the pin on one side outer circumferential surface of the main pin 3, is caught by a fixing groove 4a formed on one side of the movable contact 4, and the other end thereof. It is fixed to the spring pins 5 penetrating both side walls of the main shaft 2 and is installed to receive a torsion according to the rotation of the movable contactor 4 when opening the contacts 4b and 9b.

At this time, the spring pin (at the time of rotation of the movable contactor 4 by the electromagnetic repulsion force at a position which is almost point symmetrical about the main pin 3 with respect to the fixing groove 4a formed on one side of the movable contactor 4) The cam groove 7 is formed so as to be caught by 5) and keep the movable contact 4 open from the fixed contact 9.

On the other hand, the inner side plate (2a) of the main shaft (2) when the main pin (3) is inserted, guide grooves (8) for guiding both ends of the main pin (3) is formed.

The assembly process and action of the current-limiting device of the present invention configured as described above are as follows.

When the current-limiting device of the present invention is assembled, the movable contactor 4 and the torsion spring 6 are inserted into the main pin 3, and the movable contactor 4 and the torsion spring 6 are inserted into the main pin 3. Is inserted through the guide groove 8 formed in the inner side plate (2a) of the main shaft (2) is installed so as to be located in the central portion of the main shaft (2).

On the other hand, the torsion spring 6 is installed so that one end is caught by the fixing groove (4a) formed on one side of the movable contact 4, the other end of the spring pin (5) penetrating both side walls of the main shaft (2) The assembly is completed by hanging on).

The current-limiting current-limiting device of the present invention assembled as described above is connected to the fixed contactor 9 and the movable contactor 4 during normal energization, as shown in FIG. 3A, through the movable contactor 4 at the power supply-side fixed contactor 9. When current flows normally to the load-side fixed contactor side and a large accident current occurs momentarily due to an abnormality in the line or load side, an electron is generated between the contact 4b of the movable contactor 4 and the contact 9b of the fixed contactor 9. As the repulsive force is generated, the movable contactor 4 is opened from the fixed contactor 9 to block the accident current.

In the normal energization, the torsion spring 6 installed on the main pin 3 acts to maintain a constant contact pressure between the fixed contact 9 and the movable contact 4.

On the other hand, when an accident current occurs, the movable contactor 4 is opened from the fixed contactor 9 by rotating the main pin 3 clockwise about its axis as shown in FIG. 3B due to the electromagnetic repulsive force between the contacts. The movable contactor 4 opened and rotated by the electromagnetic repulsive force is no longer rotated and stops as the cam groove 7 formed on one side of the movable contactor 4 is coupled to the spring pin 5 installed to correspond thereto. It keeps working.

At this time, in the present design, since the movable contactor 4 rotates the main pin 3 to the axis, the correct contact radius is obtained, so that the coupling between the cam groove 7 and the spring pin 5 is made accurately without malfunction. Therefore, the current-limiting action can be maintained more reliably.

In addition, in the current-limiting device of the present invention, since the movable contactor 4 rotates about the main pin 3, which is a fixed rotational point, as an axis, the phenomenon of flowing in the left and right directions or the front and rear directions is prevented. When operating the handle 1 to close the wiring breaker again, the contact area between the contacts 4b and 9b can be kept constant.

On the other hand, the torsion spring (6), the spring pin (5), the fixing groove (4a), the cam groove (7), etc., on the left and right of the main pin (3) and the movable contact (4) on the top to ensure a more certain current operation It can be installed symmetrically on each side.

As described above, the current-limiting device of the present invention is able to match the rotation center of the movable contactor 4 and the rotation center of the main shaft 2 in view of its structural characteristics.

Therefore, in the present invention, since the coupling between the cam groove 7 and the spring pin 5 of the movable contactor 4 is made accurately and surely, more reliable current-limiting action is maintained so that the reliability of the circuit breaker can be improved. do.

Claims (1)

The main shaft is installed to rotate in conjunction with the opening and closing mechanism when operating the handle for opening and closing, the main shaft having a structure having both side plates, the main pin is installed to penetrate through the central portion of both side plates of the main shaft, and one side of the side plate edge of the main shaft A spring pin installed to penetrate through the main pin, the movable contact having a symmetrical structure that is coupled to the main pin to rotate the main pin when opening the contact, and has contacts on both sides, and a movable contact when opening the contact by electromagnetic repulsive force. In the wiring breaker having a torsion spring that is subjected to a torsion so as to recover the; A fixed groove is formed on one side of the movable contact, and the position is almost point-symmetrical about the main pin with respect to the fixed groove, and the movable contact is caught by the spring contact when the movable contact is rotated by the electromagnetic repulsive force. A cam groove is formed to maintain a closed state, and a torsion spring wound around the outer circumferential surface of the main pin is caught by an inner side of a fixing groove formed on one side of the movable contact, and the other end of the spring pin is penetrated through both side walls of the main shaft. Current limiting device of a circuit breaker, characterized in that caught on.