Moving contact assembly of circuit breaker and contact arc extinguishing system

Abstract

The utility model relates to a moving contact assembly and a contact arc extinguishing system of a circuit breaker, and the moving contact assembly comprises a rotating shaft which is a hollow cavity with a window; one end of the moving contact is rotatably arranged in the hollow cavity, and the other end of the moving contact extends out of the window and forms a contact part matched with the static contact; the moving contact protection cover coats the moving contact extending out of the window from bottom to top; and the baffle plate is arranged at the front end of the window, and the upper end of the baffle plate is fixedly connected with the moving contact. The baffle plate is additionally arranged on the moving contact, and the baffle plate and the moving contact are arranged in a linkage manner, so that when the moving contact acts relative to the rotating shaft, the baffle plate always covers the window of the rotating shaft to block the electric arc ejected from the rear end of the arc extinguishing cover, the electric arc is prevented from being ejected into the rotating shaft to damage the contact, and the air pressure storage of the arc extinguishing chamber is facilitated; the arc is blown to the arc-extinguishing chamber by the reinforced airflow, and the arc-extinguishing capability is improved.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, specifically to a moving contact assembly and contact arc extinguishing system for a circuit breaker. Background Technology

[0002] Molded case circuit breakers typically consist of moving and stationary contacts. Making a circuit is achieved through the contact between these contacts, and breaking a circuit is achieved through their separation. To prevent arcing and burning of the moving contacts, existing molded case circuit breakers often incorporate an arc-damping shield on the moving contacts. However, these shields typically cover only a small portion of the moving contact, leaving that part of the moving contact exposed at the shaft. This results in poor insulation, making this area, as well as the portion of the moving contact located within the shaft, highly susceptible to arcing and burning. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a moving contact assembly and contact arc extinguishing system for a circuit breaker.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A moving contact assembly of a circuit breaker, comprising:

[0006] The pivot is a hollow cavity with a window.

[0007] The moving contact has one end rotatably disposed in the hollow cavity, and the other end extends out of the window and forms a contact portion that cooperates with the stationary contact.

[0008] The moving contact protective cover covers the moving contact protruding from the window from bottom to top;

[0009] A baffle is provided at the front end of the window, and its upper end is fixedly connected to the moving contact.

[0010] The moving contact is provided with a through hole, and the upper end of the baffle is provided with symmetrical positioning holes, and the positioning holes are corresponding to the through holes, and the two are connected by a pin.

[0011] The upper part of the baffle is U-shaped, and the bottom of the U-shaped structure is provided with a positioning block for fitting with the moving contact at the contact position.

[0012] The positioning block is formed by extending from the front and rear sides of the baffle.

[0013] The baffle is arc-shaped and matches the front end face of the rotating shaft.

[0014] An arc-extinguishing system includes a moving contact assembly of the circuit breaker described above, and further includes a stationary contact assembly and an arc-extinguishing chamber that are disposed corresponding to the moving contact of the moving contact assembly of the circuit breaker.

[0015] The upper end of the arc-extinguishing chamber is equipped with a semi-enclosed arc-extinguishing cover.

[0016] The semi-enclosed arc-extinguishing shroud is located above the moving contact.

[0017] The arc-extinguishing chamber, baffle, stationary contact assembly, and circuit breaker housing together form an isolation space.

[0018] The beneficial effects of this utility model are as follows: By adding a baffle to the moving contact, and the baffle being linked to the moving contact, the baffle always covers the window of the rotating shaft when the moving contact moves relative to the rotating shaft, thus blocking the electric arc ejected from the rear end of the arc extinguishing chamber and preventing the electric arc from being injected into the rotating shaft and damaging the contact. At the same time, it is also beneficial for the arc extinguishing chamber to store air pressure, strengthen the airflow to blow the electric arc into the arc extinguishing chamber, and improve the arc extinguishing capability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the moving contact assembly of this utility model.

[0020] Figure 2 This is a cross-sectional schematic diagram of the moving contact assembly of this utility model.

[0021] Figure 3 This is a schematic diagram of the baffle installation of the moving contact assembly of this utility model.

[0022] Figure 4 This is a schematic diagram of the baffle of the moving contact assembly of this utility model.

[0023] Figure 5 This is a schematic diagram of the contact arc extinguishing system of this utility model.

[0024] Figure 6 This is a schematic diagram of the static contact assembly and arc-extinguishing chamber of this utility model.

[0025] Figure 7 This is a cross-sectional schematic diagram of the stationary contact assembly and the arc-extinguishing chamber of this utility model.

[0026] Figure 8 This is a schematic diagram of the installation of the arc-leading angle and the stationary contact of this utility model.

[0027] Figure 9 This is a schematic diagram of the arc-extinguishing chamber of this utility model.

[0028] Figure 10 This is a schematic diagram showing the cooperation between the magnetizing block and the magnetizing sheet of this utility model.

[0029] Figure 11 This is a cross-sectional schematic diagram of the arc-extinguishing chamber of this utility model.

[0030] Figure 12 This is a schematic diagram of the arc-extinguishing cover of this utility model. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] like Figure 1 As shown, this utility model discloses a moving contact assembly of a circuit breaker, which includes a rotating shaft 100, a moving contact 200, a moving contact protective cover 300, and a baffle 400. The moving contact protective cover and the baffle are designed separately, that is, they are installed independently, which reduces the processing difficulty. At the same time, the baffle always moves with the moving contact, so it can always block the window of the rotating shaft and block the arc ejected from the rear end of the arc extinguishing cover, preventing the arc from being injected into the rotating shaft and damaging the contact.

[0034] The rotating shaft 100 is a hollow cavity with a window 110. The rotating shaft 100 is rotatably installed inside the circuit breaker housing and is used to drive the moving contact to move relative to the stationary contact.

[0035] like Figure 2 As shown, the moving contact 200 has one end rotatably disposed in the hollow cavity, and the other end extends out from the window 110 and forms a contact portion 210 that cooperates with the stationary contact. The contact portion 210 is a silver contact.

[0036] The moving contact protective cover 300 covers the moving contact 200 extending from the window 110 from bottom to top. The moving contact protective cover 300 is made of insulating material and serves to protect the moving contact 200.

[0037] A baffle 400 is disposed at the front end of the window 110, and its upper end is fixedly connected to the moving contact 200.

[0038] like Figure 3 As shown, the moving contact 200 has a through hole 220, and the baffle 400 has symmetrically arranged positioning holes 410 on its upper end. The positioning holes 410 and the through holes 220 are correspondingly arranged and connected by a pin 500. The upper end of the baffle 400 has a U-shaped structure, as shown in the figure. Figure 4 As shown, a positioning block 420 for fitting with the moving contact 200 is provided at the bottom of the U-shaped structure where it contacts the moving contact 200. The baffle 400 is installed directly from bottom to top with the moving contact, and then the two are fixed by a pin. At the same time, the positioning block 420 fits against the bottom of the moving contact to prevent the baffle from rotating and to ensure that the position of the baffle remains unchanged and does not wobble.

[0039] The positioning block 420 is formed by extending from the front and rear sides of the baffle 400 respectively. It extends forward and backward from the baffle, and its upper end surface fits against the bottom of the moving contact, thereby ensuring that the two are tightly fixed.

[0040] The baffle 400 is arc-shaped and matches the front end face of the rotating shaft 100. When the moving contact moves relative to the rotating shaft, the baffle always fits against the rotating shaft to ensure that the window is always covered.

[0041] like Figure 5 As shown, a contact arc extinguishing system includes the moving contact assembly of the circuit breaker described above, and further includes a stationary contact assembly 600 and an arc extinguishing chamber 700 that are disposed corresponding to the moving contact of the moving contact assembly of the circuit breaker.

[0042] The upper end of the arc-extinguishing chamber 700 is provided with a semi-enclosed arc-extinguishing cover 710.

[0043] The semi-enclosed arc-extinguishing shroud 710 is located above the moving contact 200.

[0044] The arc-extinguishing chamber 700, baffle 400, stationary contact assembly 600, and circuit breaker housing enclose an isolation space. A semi-enclosed arc-extinguishing hood is installed inside the arc-extinguishing chamber to increase the air blowing capacity. A baffle is installed on the moving contact to block the arc ejected from the rear end of the semi-enclosed arc-extinguishing hood, preventing the arc from entering the rotating shaft and damaging the contacts. At the same time, it is also beneficial for the arc-extinguishing chamber to store air pressure, strengthen the airflow to blow the arc into the arc-extinguishing chamber, and improve the arc extinguishing capacity.

[0045] like Figure 6 As shown, there is an arc-extinguishing chamber 700 and a stationary contact assembly disposed below the arc-extinguishing chamber, the stationary contact assembly blocking the lower opening of the arc-extinguishing chamber.

[0046] like Figure 7 As shown, the stationary contact assembly 600 includes a stationary contact, which consists of a front U-shaped portion 610 and a rear connecting portion 620. The front U-shaped portion is divided into an upper end face and a lower end face, which are arranged in parallel. The lower end face is connected to the rear connecting portion. The upper end face of the front U-shaped portion 610 is provided with a stationary contact 630, which is a silver contact and is welded and fixed to the front U-shaped portion 610. The rear connecting portion 620 is provided with an arc-starting angle 40, which is oriented towards the stationary contact 630.

[0047] Meanwhile, the upper end of the arc-starting angle 40 is flush with the welding surface of the stationary contact 630, and the arc generated on the stationary contact is started by using equipotentiality, which increases the arc-starting effect in the initial stage of the arc and the effect of cutting and breaking the arc.

[0048] The distance between the front end of the arc-initiating angle 40 and the stationary contact 630 is 1-2mm, which is as close as possible to the stationary contact, thereby enabling faster arc initiation.

[0049] For ease of processing, one side of the arc-starting angle 40 is riveted to the tail connecting part 620 via an L-shaped connector 41. Specifically, a riveting groove is provided on the tail connecting part 620, and the L-shaped connector 41 is riveted into this groove, improving processing efficiency. Figure 8 As shown.

[0050] like Figure 11 As shown, the rear end of the arc-extinguishing chamber is provided with a partition plate, the partition plate is provided with several air outlets, and insulating paper is provided on its rear side. The insulating paper 50 partially enters the arc-extinguishing chamber, covers the rear end connection part 620, and extends to the upper end of the arc-starting angle, thus playing an insulating role inside.

[0051] A magnetizing block 30 is provided in the middle of the front U-shaped portion 610, and a positioning groove 640 for fixing the magnetizing block 30 is provided on the lower end surface of the front U-shaped portion 610. The design of the positioning groove facilitates the installation of the magnetizing block. The presence of the magnetizing block can cooperate with the magnetizing sheet inside the arc-extinguishing shroud to form a U-shaped magnetic field, such as... Figure 10 As shown, the electric arc is rapidly introduced into the arc-extinguishing chamber by a magnetic field.

[0052] like Figure 9 As shown, the arc-extinguishing chamber 700 includes a pair of opposing side plates 750, a plurality of arc-extinguishing grids spaced vertically between the two side plates 750, and a semi-enclosed arc-extinguishing cover 710 disposed at the front end of the arc-extinguishing chamber. The semi-enclosed arc-extinguishing cover 710 includes two opposing arc-extinguishing side plates 751, a stationary contact protection cover 752 disposed at the bottom of the arc-extinguishing side plates 751, and an arc-extinguishing top plate 753 disposed at the top of the two arc-extinguishing side plates 751. The arc-extinguishing top plate 753 closes the upper opening of the arc-extinguishing chamber 700. Figure 12 As shown.

[0053] The stationary contact protection cover seals the lower end of the arc-extinguishing cover, protecting the stationary contact from arc transfer and burning when the stationary contact breaks, thus reducing the actual opening distance of the contact.

[0054] The design of the arc-extinguishing top plate is beneficial for storing gas pressure in the arc-extinguishing chamber.

[0055] like Figure 11 As shown, the arc-extinguishing side plate wraps around the long arc-extinguishing grid plate, and the arc-extinguishing cover is fixed by the arc-extinguishing grid plate to prevent the two sides of the arc-extinguishing cover from shrinking towards the middle (see the direction of shrinkage). Figure 11(Middle arrow), stuck moving contact.

[0056] The bottom of the arc-extinguishing side plate 751 is provided with a slot for placing the magnetizing sheet 60. The magnetizing sheet can be made of iron chips. Iron chips are set inside the two sides of the lower end of the arc-extinguishing cover. Together with the magnetizing block of the stationary contact, they form a U-shaped magnetic field structure. By increasing the magnetic field to induce arc, the speed at which the arc enters the arc-extinguishing chamber is rapidly increased, thereby improving the product's breaking capacity.

[0057] The arc-extinguishing grids are divided into two groups: one group consists of multiple overlapping long arc-extinguishing grids 720, and the other group consists of multiple overlapping short arc-extinguishing grids 730. The short arc-extinguishing grids 730 are positioned between the arc-starting angle 40 and the long arc-extinguishing grids 720. The short arc-extinguishing chamber grids are positioned within the space cleared by the arc-starting angle; specifically, three 2.0mm thick arc-starting plates are designed on the arc-extinguishing chamber above the arc-starting angle to enhance the arc-starting effect and cut off the arc in the initial stage. The long arc-extinguishing grids are arranged in a fan shape along the height direction, ensuring that the distance between each arc-extinguishing grid and the moving contact blade during disconnection and rotation is equidistant, thus ensuring the arc-starting effect. An arc-starting plate 740 is positioned at the top of the arc-extinguishing chamber to ensure that the arc is completely introduced into the arc-extinguishing chamber after the moving contact blade disconnects.

[0058] In addition to its arc-initiating effect, the short arc-extinguishing grid also serves to divide the electric arc into multiple segments (see...). Figure 7 (Schematic diagram of arc ignition direction in the middle of the electric arc) Increasing the arc voltage is beneficial for quickly extinguishing the arc and improving breaking capacity.

[0059] The use of magnetizing blocks and magnetizing sheets to induce arcing with a magnetic field, and the use of arc-extinguishing grids and air blowing from the arc-extinguishing hood to expel the arc, improves the speed at which the arc moves to the arc-extinguishing device and enhances the arc-extinguishing effect.

[0060] The embodiments should not be regarded as limitations on the present invention, but any improvements made based on the spirit of the present invention should be within the protection scope of the present invention.

Claims

1. A moving contact assembly for a circuit breaker, characterized by: It includes: The rotating shaft (100) is a hollow cavity with a window (110); The moving contact (200) has one end rotatably disposed in the hollow cavity, and the other end extends out from the window (110) and forms a contact portion (210) that cooperates with the stationary contact. A moving contact protective cover (300) covers the moving contact (200) of the protruding window (110) from bottom to top; A baffle (400) is disposed at the front end of the window (110), and its upper end is fixedly connected to the moving contact (200).

2. The movable contact assembly of claim 1, wherein: The moving contact (200) is provided with a through hole (220), and the upper end of the baffle (400) is symmetrically provided with positioning holes (410), and the positioning holes (410) are correspondingly provided with the through hole (220), and the two are connected by a pin (500).

3. A moving contact assembly for a circuit breaker according to claim 1 or 2, characterized in that: The upper end of the baffle (400) is a U-shaped structure, and a positioning block (420) for fitting with the moving contact (200) is provided at the bottom of the U-shaped structure where it contacts the moving contact (200).

4. The movable contact assembly of claim 3, wherein: The positioning block (420) is formed by extending from the front and rear sides of the baffle (400).

5. The movable contact assembly of claim 3, wherein: The baffle (400) is arc-shaped and matches the front end face of the rotating shaft (100).

6. A contact arc quenching system characterized by: It includes the moving contact assembly of the circuit breaker as described in any one of claims 1 to 5, and further includes a stationary contact assembly (600) and an arc-extinguishing chamber (700) corresponding to the moving contact of the moving contact assembly of the circuit breaker.

7. A contact arc quenching system as claimed in claim 6, characterized in that: The upper end of the arc-extinguishing chamber (700) is provided with a semi-enclosed arc-extinguishing hood (710).

8. A contact arc quenching system as claimed in claim 7, characterized in that: The semi-enclosed arc extinguishing shroud (710) is located above the moving contact (200).

9. A contact arc extinguishing system according to claim 6, 7, or 8, characterized in that: The arc-extinguishing chamber (700), baffle (400), stationary contact assembly (600), and circuit breaker housing together form an isolation space.

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