CN102891049A - Contact structure of air circuit breaker - Google Patents

Abstract

The invention relates to a component structure of power transmission equipment, in particular to a contact structure of a DC circuit breaker. The front side of the upper section of the movable contact is provided with a movable contact that cooperates with the static contact on the static contact; the middle part of the movable contact is provided with a middle spring, and the middle spring exerts a spring force backward on the middle part of the movable contact The lower part of the movable contact is provided with a lower spring, and the lower spring exerts a spring force on the lower part of the movable contact; the lower part of the movable contact also has a waist-shaped hole in the front and rear direction, and passes through the waist-shaped hole. The hole is matched with a fixed shaft pin, so that the lower part of the movable contact can move forward and backward under the limit of the waist-shaped hole; pole. The invention reduces the requirement on the strength performance of the components, thereby reducing the cost; at the same time, the invention can increase the opening speed and meet the higher operation performance requirement.

Description

Air circuit breaker contact structure

technical field

The invention relates to a component structure of power distribution equipment, in particular to a contact structure of an air circuit breaker.

Background technique

When the air circuit breaker closes and breaks the current, it must overcome the large electric repulsion force and contact pressure, etc., and must reach a certain opening and closing speed, so that the closing work and opening work increase with the increase of the current. The increase has led to a great increase in the performance requirements of materials such as contacts, which has increased the cost of materials, which in turn affects the overall development and application of high-current breaking equipment.

Contents of the invention

The technical problem to be solved by the present invention is to provide a contact structure of an air circuit breaker that can reduce the closing driving force, lower the material performance requirements and increase the opening speed while satisfying the contact performance of the contacts.

The air circuit breaker contact structure of the present invention includes a fixed static contact and a movable movable contact; the front side of the upper section of the movable contact is provided with a movable contact that cooperates with the static contact on the static contact; The middle part of the movable contact is provided with a middle spring, and the middle spring exerts a spring force backward on the middle part of the movable contact; the lower part of the movable contact is provided with a lower spring, and the lower spring applies a backward spring to the lower part of the movable contact. Force; the lower part of the moving contact also has a waist-shaped hole in the front and rear direction, and through the waist-shaped hole and a fixed shaft pin, the lower part of the moving contact can move forward and backward under the limit of the waist-shaped hole. Rearward movement; the rear side of the moving contact is provided with a push rod capable of applying a forward force to the middle of the moving contact, and the push rod is driven by a power device.

The middle part of the moving contact is provided with a middle fulcrum shaft, and the middle spring forms a backward acting force on the moving contact through the middle fulcrum shaft.

The lower part of the moving contact is provided with a lower fulcrum shaft, and the lower spring forms a backward force on the moving contact through the lower fulcrum shaft. .

The middle stopper and the lower stopper are insulating materials.

The middle spring and the lower spring may be compression springs located at the front side of the moving contact or extension springs located at the rear side of the moving contact.

In the present invention, through the reasonable setting of the force application positions of the push rod, the middle spring, the lower spring and other components, the whole device can have a relatively large contact pressure between the movable contact and the static contact under the condition of applying a relatively small driving force. The requirement on the strength performance of the component is lowered, thereby reducing the cost; at the same time, the invention can increase the opening speed and meet the higher operation performance requirement.

Description of drawings

Fig. 1 is a schematic diagram of the closed state structure of an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of the opening state of the embodiment of the present invention.

Detailed ways

As shown in the figure, the air circuit breaker contact structure includes a fixed static contact 2 and a movable movable contact 1; 21 Coordinated moving contact 11; a middle spring 4 is arranged between the middle of the moving contact 1 and the middle stopper 3 located in the middle of the front of the moving contact. spring force; a lower spring 6 is arranged between the lower part of the movable contact 1 and the lower block 5 arranged at the lower part in front of the movable contact, and the lower spring 6 is a compression spring, which applies a spring force backward to the lower part of the movable contact; The lower part of the movable contact 1 also has a waist-shaped hole 12 in the front and rear direction, and cooperates with a fixed shaft pin 7 through the waist-shaped hole, so that the lower part of the movable contact can move forward and backward under the limit of the waist-shaped hole 12. Rear movement; the rear side of the movable contact 1 is provided with a push rod 8 capable of applying a forward force to the middle of the movable contact, and the push rod is driven by a power device. A central fulcrum shaft 13 is arranged in the middle of the movable contact 1 , and the movable contact 1 interacts with the central spring 4 through the central fulcrum shaft 13 . The lower part of the movable contact 1 is provided with a lower fulcrum shaft 14 , and the movable contact 1 interacts with the lower spring 6 through the lower fulcrum shaft 14 . The middle stopper 3 and the lower stopper 5 are insulating materials. The middle spring and the lower spring can also be tension springs located at the rear side of the moving contact.

Structural principle of the present invention is:

As shown in Figure 1, in the closed state, the push rod 8 exerts a forward force on the middle part of the moving contact, thereby forming a fulcrum at the fulcrum axis in the middle part of the moving contact. At this time, it moves under the action of the lower spring 6. The contact has a tendency to rotate clockwise around the middle fulcrum axis, so that the movable contact 11 is in contact with the static contact 21 and pressed tightly. At this time, the force of the lower spring plays the role of providing contact pressure;

As shown in Figure 2, when the brake is opened, the driving force on the push rod 8 disappears, so that the fulcrum in the middle of the movable contact 1 disappears. At this time, the force of the middle spring 4 and the lower spring 6 makes the movable contact move backward quickly as a whole. After a certain distance, rotate counterclockwise around the lower fulcrum shaft 14, so that the movable contact 11 is separated from the static contact 21 rapidly.

The circuit breaker contact structure can be used in DC air circuit breakers and also in AC air circuit breakers.

Claims (5)

1. A circuit breaker contact structure, including a fixed static contact (2) and a movable moving contact (1); the front side of the upper section of the moving contact (1) is provided with a fixed contact (2) ) on the static contact (21) matched with the moving contact (11); the feature is: the middle part of the moving contact (1) is provided with a middle spring (4), and the middle spring exerts force on the middle part of the moving contact (1). Rearward spring force; the lower part of the moving contact (1) is provided with a lower spring (6), and the lower spring (6) exerts a spring force to the left and rearward on the lower part of the moving contact; the lower part of the moving contact (1) is also open There is a waist-shaped hole (12) in the front and rear directions, and through the waist-shaped hole, it is matched with a fixed shaft pin (7), so that the lower part of the moving contact can move forward and backward under the limit of the waist-shaped hole (12) ; The rear side of the moving contact (1) is provided with a push rod (8) capable of applying a forward force to the middle of the moving contact, and the push rod is driven by a power device. 2. The circuit breaker contact structure according to claim 1, characterized in that: the middle part of the moving contact (1) is provided with a middle fulcrum shaft (13), and the middle spring (4) is connected to the center through the middle fulcrum shaft (13). The moving contact (1) creates a backward force. 3. The circuit breaker contact structure according to claim 1, characterized in that: the lower part of the movable contact (1) is provided with a lower fulcrum shaft (14), and the lower spring (6) is formed by the lower fulcrum shaft (14) Rearward force on the moving contact (1). 4. The circuit breaker contact structure according to any one of claims 1-3, characterized in that: the middle stopper (3) and the lower stopper (5) are insulating materials. 5. The circuit breaker contact structure according to any one of claims 1-3, characterized in that: the middle spring and the lower spring are compression springs located on the front side of the moving contact or extension springs located on the rear side of the moving contact .

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