Arc extinguishing system and molded case circuit breaker

Abstract

The utility model relates to an arc extinguishing system and a molded case circuit breaker, and the arc extinguishing system comprises a static contact which comprises a straight part, the middle position of the straight part is provided with a U-shaped hollow-out groove, the U-shaped hollow-out groove divides a contact installation part on the straight part, and the contact installation part is provided with a static contact; the moving contact can move relative to the static contact; the isolation cover is fixedly arranged on the straight part and at least covers the periphery of the contact mounting part, and a notch groove for exposing a static contact is formed in the isolation cover; the arc extinguish chambers are arranged on the two sides of the motion trail of the moving contact, and the bottoms of the arc extinguish chambers and the isolation cover form a closed space. The static contact is covered by the isolation cover, and the isolation cover and the arc extinguish chamber form a closed space, so that arc gas generated during breaking can be effectively prevented from entering the position below the static contact from the static contact, the discharge of the arc gas is facilitated, and the arc extinguish effect is improved.

Description

Technical Field

[0001] The utility model specifically relates to an arc extinguishing system and a molded case circuit breaker. Background Art

[0002] A circuit breaker is a switching device that can close, carry and interrupt current under normal circuit conditions and can close, carry and interrupt current under abnormal circuit conditions within a specified time.

[0003] The static contact is an important component of the circuit breaker for achieving electrical connection (i.e., electrical connection is achieved by the moving contact and the static contact touching each other). However, the structure of the existing static contact includes a straight portion and a curved portion, wherein the curved portion is connected to one end of the straight portion and extends above the straight portion. When electrical connection is required, the moving contact rotates and touches the curved portion.

[0004] However, since this type of U-shaped static contact is placed above the straight part at the curved part, a large space will be left at the lower side of the curved part. When the moving contact is disconnected from the static contact, the arc gas will enter under the curved part, resulting in poor gas discharge, which is not conducive to arc extinguishing. Utility Model Content

[0005] In view of the deficiencies in the prior art, the purpose of the utility model is to provide an arc extinguishing system and a molded case circuit breaker.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] An arc extinguishing system, comprising:

[0008] A stationary contact, comprising a straight portion, a U-shaped hollow groove is provided in the middle of the straight portion, the U-shaped hollow groove divides a contact mounting portion on the straight portion, and a stationary contact point is provided on the contact mounting portion;

[0009] The moving contact can be set to move relative to the stationary contact;

[0010] An isolation cover is fixedly arranged on the straight portion, covers at least the periphery of the contact mounting portion, and is provided with a notch groove exposing the static contact;

[0011] The arc extinguishing chamber is arranged on both sides of the moving track of the moving contact, and the bottom of the arc extinguishing chamber and the isolation cover form a closed space.

[0012] Furthermore, the isolation cover includes a flat plate structure, and a notch groove matching the contact mounting portion is provided at the front end of the flat plate structure.

[0013] Furthermore, the flat plate structure extends downward along the circumference of the notch groove to form a protrusion that matches the U-shaped hollow groove.

[0014] Furthermore, a bent plate extending upward is provided at the rear end of the flat plate structure.

[0015] Furthermore, reinforcing plates are provided on both sides of the connection between the bent plate and the flat plate structure.

[0016] Furthermore, the rear end of the contact mounting portion extends to form a fixed end.

[0017] Furthermore, the arc extinguishing chamber comprises two symmetrically arranged side plates and a plurality of arc extinguishing grids stacked between the side plates, and an arc striking angle is provided on the uppermost arc extinguishing grid in a direction close to the moving contact.

[0018] Furthermore, the arc striking angle comprises a first guide plate and a second guide plate connected to the uppermost arc extinguishing grid, an acute angle is formed between the second guide plate and the first guide plate, and an opening of the angle is arranged upward.

[0019] Furthermore, the second guide plate is arranged parallel to the front end surface of the moving contact in the repelled state.

[0020] A molded case circuit breaker comprises a circuit breaker body, wherein a plurality of arc extinguishing systems are arranged inside the circuit breaker body.

[0021] The beneficial effects of the present invention are as follows: the original U-shaped contact is changed into a flat contact, and a U-shaped hollow groove is used to form a flat U-shaped contact, which can also provide repulsion under large current to ensure the breaking performance of the product, and at the same time simplify the structure of the contact, with a simple process and reduced costs. At the same time, an isolation cover is used to cover the static contact, and a closed space is formed with the arc extinguishing chamber, which can effectively prevent the arc gas generated during breaking from the static contact into the bottom thereof, which is beneficial to the discharge of the arc gas and improves the arc extinguishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the coordination of the arc extinguishing system applied to the molded case circuit breaker.

[0023] Figure 2 It is a structural schematic diagram of the arc extinguishing system of the utility model.

[0024] Figure 3 It is a cross-sectional view of the arc extinguishing system of the utility model.

[0025] Figure 4 It is a schematic diagram of the structure of the static contact and the isolation cover of the utility model.

[0026] Figure 5 It is a structural diagram of the static contact.

[0027] Figure 6 It is a schematic diagram of the structure of the isolation cover. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] like Figure 2-6 An arc extinguishing system is shown, comprising:

[0031] The static contact 4 includes a straight portion 41, which is formed by bending a straight plate twice to form a straight portion 41 and a contact connecting portion 42, a certain height difference is formed between the two, and the straight portion and the contact connecting portion are arranged in parallel, a U-shaped hollow groove 411 is arranged in the middle of the straight portion, and the U-shaped hollow groove divides a contact mounting portion 43 on the straight portion, and a static contact point 431 is arranged on the contact mounting portion;

[0032] The moving contact 2 can be arranged to move relative to the stationary contact;

[0033] The isolation cover 5 is fixedly arranged on the straight portion 41, covering at least the surrounding of the contact mounting portion, and the isolation cover is provided with a notch groove 52 for exposing the static contact. Preferably, the isolation cover completely covers the static contact, and only the static contact is exposed;

[0034] The arc extinguishing chamber 3 is arranged on both sides of the moving track of the moving contact, and the bottom of the arc extinguishing chamber and the isolation cover form a closed space, that is, the isolation cover cooperates with the bottom of the arc extinguishing chamber to achieve the closure of the static contact, preventing the arc gas from entering the bottom of the static contact from the static contact and affecting the discharge of the arc gas.

[0035] Furthermore, the isolation cover 5 includes a flat plate structure 51, and a notch groove 52 adapted to the contact mounting portion is provided at the front end of the flat plate structure. The notch groove fits the mounting portion and can be slightly pressed against the periphery of the contact mounting portion to achieve a better sealing effect.

[0036] Furthermore, the flat plate structure extends downward along the circumference of the notch groove to form a protrusion 53 that is compatible with the U-shaped hollow groove. The protrusion can be an integral whole or surrounded by a wall-like structure. It is filled in the U-shaped hollow groove, further improving the sealing of the U-shaped hollow groove. At the same time, it also forms a limiting fit with the U-shaped hollow groove to prevent positional displacement between the isolation cover and the static contact, which affects the sealing effect.

[0037] Furthermore, the rear end of the flat plate structure is provided with a bent plate 54 extending upward, the upper end of which is fitted on the contact connection portion to achieve the closure of the lower end as much as possible, so that only the static contact point is exposed at the position of the static contact placed below the arc extinguishing chamber.

[0038] The isolation cover is made of insulating material and can cover the entire area of ​​the contact installation part except the joint part, effectively increasing the creepage distance between the moving and static contacts, protecting the static contacts from arc erosion over a large area, and increasing the insulation distance when the moving and static contacts are disconnected, thereby improving the breaking capacity and the service life of the moving and static contacts.

[0039] Furthermore, reinforcing plates 55 are provided on both sides of the connection between the bent plate and the flat plate structure, and the strength of the isolation cover is achieved by the reinforcing plates. Meanwhile, the reinforcing plates can also be used to contact the side walls of the arc extinguishing chamber to achieve a better sealing effect.

[0040] The rear end of the contact mounting portion extends to form a fixed end 44, and a threaded hole is provided on the fixed end, which is directly connected to the housing 1 of the molded case circuit breaker through screws. A boss 11 is provided in the housing 1, and the static contact is placed on the boss and fixed with screws, which is more convenient in installation and improves production efficiency.

[0041] Furthermore, the width of the flat plate structure is greater than the width of the straight portion, and is preferably consistent with the distance between the two side plates, so that it can completely cooperate with the side plates to achieve sealing below the arc extinguishing chamber.

[0042] Furthermore, the arc extinguishing chamber includes two symmetrically arranged side plates and a plurality of arc extinguishing grids stacked between the side plates, and the arc ignition angle 31 is provided on the uppermost arc extinguishing grid in the direction close to the moving contact, and the arc ignition angle includes a first guide plate 312 and a second guide plate 311 connected to the uppermost arc extinguishing grid, and an acute angle is formed between the second guide plate and the first guide plate, and the opening of the angle is arranged upward. By using the arrangement of the second guide plate, the arc generated when the moving contact is repelled is guided downward from the second guide plate to the first guide plate, and introduced into the arc extinguishing chamber, thereby improving the arc ignition effect and further increasing the arc extinguishing speed.

[0043] Furthermore, the second guide plate 311 is arranged parallel to the front end surface 21 of the moving contact in the repelled state, and there is a gap between the second guide plate and the moving contact. The second guide plate is used to introduce the arc of the moving contact into itself, and the uppermost arc extinguishing grid is stacked with other arc extinguishing grids in the arc extinguishing chamber to put the arc into the first arc extinguishing chamber.

[0044] like Figure 1 As shown, a molded case circuit breaker includes a circuit breaker body, and a plurality of the above-mentioned arc extinguishing systems are arranged inside the circuit breaker body.

[0045] The embodiments should not be regarded as limiting the present invention, but any improvements based on the spirit of the present invention should be within the protection scope of the present invention.

Claims

1. An arc extinguishing system, characterized in that: It includes: A stationary contact, comprising a straight portion, a U-shaped hollow groove is provided in the middle of the straight portion, the U-shaped hollow groove divides a contact mounting portion on the straight portion, and a stationary contact point is provided on the contact mounting portion; The moving contact can be set to move relative to the stationary contact; An isolation cover is fixedly arranged on the straight portion, covers at least the periphery of the contact mounting portion, and is provided with a notch groove exposing the static contact; The arc extinguishing chamber is arranged on both sides of the moving track of the moving contact, and the bottom of the arc extinguishing chamber and the isolation cover form a closed space.

2. An arc extinguishing system according to claim 1, characterized in that: The isolation cover comprises a flat plate structure, and a notch groove matching the contact mounting portion is provided at the front end of the flat plate structure.

3. An arc extinguishing system according to claim 2, characterized in that: The flat plate structure extends downward along the circumference of the notch groove to form a protrusion that matches the U-shaped hollow groove.

4. An arc extinguishing system according to claim 2, characterized in that: A bent plate extending upward is provided at the rear end of the flat plate structure.

5. An arc extinguishing system according to claim 4, characterized in that: Reinforcement plates are provided on both sides of the connection between the bent plate and the flat plate structure.

6. An arc extinguishing system according to claim 1, 2, 3, 4 or 5, characterized in that: The rear end of the contact mounting portion extends to form a fixed end.

7. An arc extinguishing system according to claim 1, characterized in that: The arc extinguishing chamber comprises two symmetrically arranged side plates and a plurality of arc extinguishing grids stacked between the side plates, and an arc striking angle is arranged on the uppermost arc extinguishing grid in a direction close to the moving contact.

8. An arc extinguishing system according to claim 7, characterized in that: The arc striking angle comprises a first guide plate and a second guide plate connected to the uppermost arc extinguishing grid, an acute angle is formed between the second guide plate and the first guide plate, and an opening of the angle is arranged upward.

9. An arc extinguishing system according to claim 8, characterized in that: The second guide plate is arranged parallel to the front end surface of the moving contact in the repelled state.

10. A molded case circuit breaker, comprising a circuit breaker body, characterized in that: Several arc extinguishing systems according to any one of claims 1 to 9 are arranged inside the circuit breaker body.

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