A circuit breaker and contact assembly therefor

Abstract

The utility model provides a kind of contact assembly, including static contact and moving contact, static contact includes: contact seat, including fixed plate and installation frame;Static contact point;Arc leading piece, including two third connecting parts;The first end of two third connecting parts is connected by the arc leading angle of oblique setting, and the second end of both is connected with an installation part, and the second end of the first connecting part located in its directly below is connected with the installation part;Gap is equipped between third connecting part and first connecting part;Magnetic conducting piece.The utility model further provides a kind of circuit breaker.The utility model has beneficial effect in that, by improving the structure of contact seat, arc leading piece and magnetic conducting piece, it realizes the electric repulsion of contact assembly under the premise of not occupying more installation space is increased, and the assembly structure of static contact is simplified, assembly efficiency is improved, and cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical technology, and in particular to a circuit breaker and its contact assembly. Background Technology

[0002] Existing circuit breakers often incorporate design features in the stationary contact to ensure that the current flowing through the stationary contact is opposite to that flowing through the moving contact when energized, creating an electro-repulsive force between the two contacts. When breaking a short-circuit current, this electro-repulsive force quickly pulls up the moving contact, causing the stationary and moving contacts to separate rapidly and thus disconnecting the circuit. Simultaneously, existing stationary contact structures also include a U-shaped magnetic conductor and an arc-starting angle. The magnetic conductor, located near the stationary contact, enhances the magnetic field strength in the contact area between the moving and stationary contacts, increasing the electro-repulsive force and improving the short-circuit breaking capacity of the circuit breaker. The arc-starting angle directs the electric arc generated during the separation of the moving and stationary contacts into the arc-extinguishing chamber, preventing excessive burning of the stationary contact and ensuring the safe and stable operation of the circuit breaker.

[0003] Existing stationary contacts with the aforementioned U-shaped magnetic conductor and arc-starting angle generally suffer from problems such as complex installation structures and excessive space occupation. For example, Chinese utility model patent CN221747135U discloses a contact assembly and circuit breaker, whose stationary contact includes a second straight section and a second downward bending section. The current flows downward through the second downward bending section, while the current flowing between the moving contact and the second straight section flows upward. By improving the shape of the stationary contact, the electrodynamic repulsion between the moving and stationary contacts is increased, but this structure results in the stationary contact occupying more installation space in the height direction. Furthermore, this patent does not specify the specific connection method between the arc-starting angle, the magnetic conductor, and the second straight section. If a one-piece molding structure is adopted, the processing of this complex structure is difficult; if a split molding method is adopted, and then fixed separately by riveting or welding, the assembly efficiency will be reduced, the production cost will be increased, and there is also a risk of misassembly or omission. Utility Model Content

[0004] The purpose of this utility model is to provide a contact assembly that has sufficient circuit repulsion force to separate the moving and stationary contacts, and also has a relatively simple assembly structure.

[0005] This utility model provides a contact assembly, including a stationary contact and a moving contact. The stationary contact includes: a contact base, including a fixing plate and a mounting frame. The mounting frame includes two first connecting parts, the first ends of which are connected to the fixing plate, and the second ends of which are connected through second connecting parts. A support plate is also connected to the second connecting part, the support plate being located between the two first connecting parts, and a receiving groove is formed between each first connecting part and the support plate; a stationary contact is disposed on the support plate; and an arc-starting element, including two third connecting parts, each of which has a [missing element] directly above it. The third connecting part; the first ends of the two third connecting parts are connected by an inclined arc-drawing angle, and the second ends of each are connected to a mounting part, the mounting part being connected to the second end of the first connecting part located directly below it; a gap extending along the extension direction of the third connecting part is provided between the third connecting part and the first connecting part; the magnetic conductive element includes two vertical plates connected in a U-shape and a horizontal plate, each receiving groove accommodating one of the vertical plates, the horizontal plate being located below the support plate, and the stationary contact being located between the two vertical plates; the magnetic conductive element is respectively limited and connected to the mounting frame and the arc-drawing element.

[0006] Preferably, the second end of the first connecting part is provided with a riveting protrusion, and the mounting part is provided with a countersunk hole for riveting with the riveting protrusion.

[0007] Preferably, a limiting groove is provided at one end of the support plate away from the second connecting part, and a limiting hook is provided on the vertical plate to limit and cooperate with the limiting groove.

[0008] Preferably, the inner side of the third connecting part is provided with a limiting protrusion for abutting against the vertical plate, and the arc corner is provided with a limiting surface for abutting against the vertical plate.

[0009] Preferably, the horizontal plate is provided with positioning holes, and the bottom of the support plate is provided with positioning posts that are inserted and cooperate with the positioning holes.

[0010] Preferably, the side of the stationary contact closest to the second connecting portion is flush with the side of the vertical plate closest to the second connecting portion.

[0011] Preferably, the fixing plate is provided with a first vent hole.

[0012] Preferably, the bottom of the support plate is provided with a reinforcing rib, which is located directly below the stationary contact.

[0013] This utility model also provides a circuit breaker, including the aforementioned contact assembly.

[0014] Preferably, the device further includes a base in which the contact assembly, an arc-extinguishing chamber disposed above the arc-initiating element, and a protective assembly disposed between the arc-extinguishing chamber and the stationary contact are installed.

[0015] The advantages of this utility model are that by improving the structure of the contact base, the arc-initiating element, and the magnetic conductor, the electric repulsive force of the contact assembly is increased without occupying more installation space, and the assembly structure of the stationary contact is simplified. The arc-initiating element and the magnetic conductor can be fixed on the contact base without additional fasteners such as rivets, thereby improving assembly efficiency and reducing costs. Attached Figure Description

[0016] Figure 1 This is a perspective view of the contact assembly (including the current path) in Embodiment 1 of this utility model;

[0017] Figure 2 A three-dimensional view of the stationary contact;

[0018] Figure 3 and Figure 4 Three-dimensional images of the contact seat from different perspectives;

[0019] Figure 5 This is a three-dimensional view of the magnetic conductive component;

[0020] Figure 6 Schematic diagrams of the assembly structure of the contact seat and magnetic conductor from different perspectives;

[0021] Figure 7 and Figure 8 Three-dimensional images of the arc-drawing component from different perspectives;

[0022] Figure 9 This is a schematic diagram of the assembly structure of the contact seat, the arc-starting element, and the magnetic conductive element;

[0023] Figure 10 This is a perspective view of the circuit breaker according to Embodiment 1 of this utility model;

[0024] Figure 11 A three-dimensional view of the base;

[0025] Figure 12 for Figure 11 Enlarged structural diagram at point A in the middle;

[0026] Figure 13 and Figure 14 Schematic diagrams of the assembly structure of the contact assembly, protective assembly and arc-extinguishing chamber from different perspectives;

[0027] Figure 15 This is a three-dimensional view of the arc-extinguishing chamber;

[0028] Figure 16This is a schematic diagram of the assembly structure of the protective component and the stationary contact.

[0029] Figure 17 A 3D view of the protective components;

[0030] Figure 18 This is a schematic diagram showing the relative positions of the moving contact, protective components, and arc-extinguishing chamber.

[0031] Figure 19 A three-dimensional view of the moving contact;

[0032] Figure 20 This is a schematic diagram showing the relative positions of the moving contact and the arc-extinguishing grid when the moving contact is in contact with the stationary contact.

[0033] Figure 21 This is a perspective view of the stationary contact in Embodiment 2 of this utility model;

[0034] Figure 22 and Figure 23 These are perspective views of the contact seat in Embodiment 2 of this utility model from different angles;

[0035] Figure 24 This is a perspective view of the magnetic conductive component in Embodiment 2 of this utility model;

[0036] Figure 25 and Figure 26 These are perspective views of the circuit breaker in Embodiment 2 of this utility model from different angles.

[0037] Figure 27 This is a schematic diagram showing the cooperation between the arc-extinguishing grid and the protective cover in Embodiment 2 of this utility model;

[0038] Figure 28 and Figure 29 This is a schematic diagram of the protective component in Embodiment 2 of this utility model from different perspectives.

[0039] In the picture:

[0040] 1. Contact seat; 11. Fixing plate; 111. First vent; 12. Mounting frame; 121. First connecting part; 122. Second connecting part; 123. Receiving groove; 13. Support plate; 131. Limiting groove; 132. First side; 133. Second side; 134. Bottom surface; 135. Support pad; 136. Positioning post; 137. Recess; 138. Reinforcing rib; 14. Riveting protrusion; 15. Gap; 16. Bending part; 161. First gap;

[0041] 2. Arc-starting component; 21. Arc-starting angle; 211. Limiting surface; 22. Third connecting part; 221. Limiting protrusion; 222. Bottom surface of the third connecting part; 23. Mounting part; 231. Bottom surface of the mounting part; 24. Countersunk hole;

[0042] 3. Static contact;

[0043] 4. Magnetic conductive component; 41. Vertical plate; 42. Horizontal plate; 421. Positioning hole; 43. Limiting hook; 431. First mating surface; 44. Second mating surface;

[0044] 5. Arc-extinguishing chamber; 51. Side plate; 511. Bottom surface of side plate; 512. Rear side surface of side plate; 513. Top surface of side plate; 514. Front side surface of side plate; 515. Second vent hole; 52. Arc-extinguishing grid plate; 521. First arc-extinguishing grid plate; 522. Second arc-extinguishing grid plate;

[0045] 6. Protective components; 61. Arc baffle; 62. Cover; 621. Protrusion; 622. Second gap; 63. Protective cover; 631. Locking block; 632. Protective groove; 633. Guide surface; 634. Limiting grid; 635. Divider plate; 636. Material reduction groove; 637. Mounting hook; 64. Isolation bracket; 641. Limiting block;

[0046] 7. Moving contact; 71. Moving contact point; 72. Conductive rod; 721. First inclined plane; 722. Second inclined plane; 7221. Lower side; 723. Guide edge;

[0047] 8. Base; 81. Base sidewall; 82. Partition; 821. Slot; 8211. First slot post; 8212. Second slot post; 8213. Slot bottom; 8214. Groove; 83. Baffle; 831. Notch; 84. Cavity; 841. Slot;

[0048] 100. Stationary contact; 200. Contact assembly. Detailed Implementation

[0049] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.

[0050] In the description of this utility model, it should be noted that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0052] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0053] Figure 3 The figure shown is a perspective view of contact seat 1. In the following description, it will be referred to as... Figure 3 The attached diagram serves as a reference for direction. Figure 3 In this design, the length direction of the contact seat 1 is defined as the front-to-back direction, and the fixing plate 11 is located on the front side of the mounting frame 12; the width direction of the contact seat 1 is defined as the left-to-right direction, and the two first connecting parts 121 are distributed along the left-to-right direction; the height direction of the contact seat 1 is defined as the up-to-down direction, and the fixing plate 11 is located above the mounting frame 12.

[0054] Example 1

[0055] like Figure 1 and Figure 2 As shown, Embodiment 1 provides a contact assembly 200, which includes a stationary contact 100 and a moving contact 7. The stationary contact 100 includes a contact base 1, a stationary contact 3, an arc-inducing element 2, and a magnetically conductive element 4.

[0056] like Figure 3 and Figure 4 As shown, the contact base 1 includes a fixing plate 11 and a mounting frame 12. The fixing plate 11 has multiple fixing holes for fixing the position of the contact base 1. The mounting frame 12 is located below the rear side of the fixing plate 11 and includes two first connecting parts 121 arranged parallel to each other in the left-right direction. Both first connecting parts 121 extend in the front-back direction. The first ends of both (here and in the following text, "first end" refers to the front end) are connected to the fixing plate 11 through a bend 16, and the second ends of both (here and in the following text, "second end" refers to the rear end) are connected through a second connecting part 122, thereby forming a frame with an opening facing forward and in the shape of a "U". A support plate 13 is also connected to the second connecting part 122. The support plate 13 is located between the two first connecting parts 121. A receiving groove 123 is formed between each first connecting part 121 and the support plate 13. The receiving groove 123 communicates with the first gap 161 formed between the two bends 16.

[0057] like Figure 1 and Figure 2As shown, the stationary contact 3 is disposed on the support plate 13. As the moving contact 7 swings, the moving contact 71 on the moving contact 7 contacts or separates from the stationary contact 3. Specifically, the stationary contact 3 is welded to the top surface of the support plate 13.

[0058] like Figure 1 , Figure 7 and Figure 8 As shown, the arc-initiating element 2 includes two third connecting portions 22 arranged parallel to each other in the left-right direction. Each third connecting portion 22 is located directly above each first connecting portion 121, and the third connecting portions 22 are parallel to the first connecting portions 121. The first ends of the two third connecting portions 22 are connected by an inclined arc-initiating angle 21, and the second ends of each are connected to a mounting portion 23, which is connected to the second end of the first connecting portion 121 located directly below it. A gap 15 extending along the extension direction (i.e., the front-back direction) of the third connecting portion 22 is provided between the third connecting portion 22 and the first connecting portion 121. The presence of the gap 15 ensures that the bottom surface 222 of the third connecting portion 22 does not contact the top surface of the first connecting portion 121, while only the bottom surface 231 of the mounting portion 23 contacts the top surface of the first connecting portion 121. The presence of the gap 15 causes the arc-initiating element 2 to generate a current direction opposite to that in the moving contact 7 when conducting electricity, and the resulting electro-repulsive force helps to accelerate the opening of the moving contact 7.

[0059] Combination Figure 1 It can be seen that when the stationary contact structure with the arc-initiating element 2 is adopted, the current will flow into the third connection part 22 through the first connection part 121 and the mounting part 23 when energized. The current direction of the current passing through the third connection part 22 is forward, while the current direction of the current flowing into the moving contact 7 through the stationary contact 3 is backward. The current directions of the two are opposite, and the magnetic force generated is repulsive. Therefore, the electric repulsive force can be increased, and the breaking speed of the moving contact 71 and the stationary contact 3 can be improved.

[0060] Specifically, such as Figure 1 , Figure 3 and Figure 7As shown, the arc-starting angle 21 is inclined upwards, meaning the height of the arc-starting angle 21 decreases sequentially from front to back. This arrangement guides the arc generated when the moving contact 71 separates from the stationary contact 3 forward and upward, entering the arc-extinguishing chamber that works in conjunction with the contact assembly. The connection method between the mounting part 23 and the second end of the first connecting part 121 located directly below it is not limited; they can be connected by riveting or welding. In a preferred embodiment of this utility model, each second end of the first connecting part 121 is provided with a riveting protrusion 14, and the mounting part 23 is provided with a countersunk hole 24 for riveting the riveting protrusion 14. When assembling the arc-starting component 2, the riveting protrusion 14 can be inserted into the countersunk hole 24, and then deformed by cold extrusion, increasing the upper surface area of ​​the riveting protrusion 14 and fitting it against the inlet end of the countersunk hole 24, thus achieving rivetless riveting.

[0061] The arc-initiating element 2 is specifically made of conductive iron. The arc-initiating angle 21 made of iron can attract the electric arc more quickly, allowing the electric arc to transfer to the arc-extinguishing chamber more quickly.

[0062] like Figure 5-6 As shown, the magnetic conductive component 4 includes two vertical plates 41 connected in a U-shape and a horizontal plate 42. Each receiving slot 123 accommodates one vertical plate 41. The height of the vertical plate 41 is greater than the height of the stationary contact 3, and the stationary contact 3 is located between the two vertical plates 41. The horizontal plate 42 is located below the support plate 13. The magnetic conductive component 4 is respectively limited and connected to the mounting frame 12 and the arc-starting component 2. The arrangement of the magnetic conductive component 4 can make the magnetic field more concentrated in the area where the stationary contact 3 is located to increase the arc-blowing force, so that the arc generated when the moving contact 71 separates from the stationary contact 3 is quickly transferred to the arc-starting angle 21, avoiding the stationary contact 3 from burning out.

[0063] Specifically, such as Figure 3 , Figure 5-6 As shown, the support plate 13 has two symmetrically distributed limiting grooves 131 at one end away from the second connecting part 122 (i.e., the front end of the support plate 13). Each limiting groove 131 includes a bottom surface 134 whose width gradually increases from front to back, a first side surface 132, and a second side surface 133 disposed behind the bottom surface 134. The first side surface 132 and the second side surface 133 are both vertically arranged planes, wherein the first side surface 132 extends in the front-back direction, and the second side surface 133 extends in the left-right direction. The front side of the vertical plate 41 is provided with a limiting hook 43 that cooperates with the limiting groove 131. Figure 7-8 As shown, each of the third connecting parts 22 has a limiting protrusion 221 on its inner side (here and in the following text, "inner side" refers to the side near the support plate 13) for abutting against the vertical plate 41. The arc-starting angle 21 has a limiting surface 211 for abutting against the vertical plate 41. The limiting surface 211 is close to the connection between the arc-starting angle 21 and the third connecting part 22 and faces the rear.

[0064] When assembling the magnetic conductor 4 on the contact seat 1, firstly, the first mating surface 431 at the bottom of the limiting hook 43 is made to fit against the bottom surface 134. Then, the limiting hook 43 is pushed along the first side surface 132 until the limiting hook 43 abuts against the second side surface 133. At this time, the limiting hook 43 is installed in the limiting groove 131, and the bottom surface of the bracket plate 13 is fitted against the top surface of the horizontal plate 42. The magnetic conductor 4 cannot move up, down, or backward, thus completing the limitation of the three degrees of freedom of the magnetic conductor 4. Next, the arc-inducing component 2 is assembled on the contact seat 1. The two countersunk holes 24 are simultaneously passed through the two riveting protrusions 14, so that the mounting part 23 is connected to the second end of the two first connecting parts 121 respectively. After assembly, the two limiting protrusions 221 abut against the outer sides of the two vertical plates 41 (here and in the following text, "outer sides" refers to the side away from the support plate 13), preventing the magnetic conductor 4 from moving left or right. Simultaneously, the front side of the vertical plate 41 is provided with a second mating surface 44 located above the limiting hook 43. The limiting surface 211 abuts against the second mating surface 44, restricting the forward movement of the magnetic conductor 4. Thus, the six degrees of freedom of the magnetic conductor 4 are limited, and the magnetic conductor 4 is securely installed in the stationary contact 100.

[0065] Furthermore, such as Figure 6 As shown, the front-to-back width d of the vertical plate 41 is greater than the front-to-back width of the stationary contact 3. One side of the stationary contact 3 near the second connecting portion 122 (i.e., the rear side of the stationary contact 3) is flush with one side of the vertical plate 41 near the second connecting portion 122 (i.e., the rear side of the vertical plate 41). That is, the front side of the stationary contact 3 is located behind the front side of the vertical plate 41, and the rear side of the stationary contact 3 and the rear side of the vertical plate 41 are positioned in the same front-to-back direction. Since the moving contact 71 and the stationary contact 3 usually make rear-side contact, the flush alignment of the rear side of the stationary contact 3 with the rear side of the vertical plate 41 ensures that the contact point between the moving contact 71 and the stationary contact 3 is within the coverage area of ​​the vertical plate 41. When the moving contact 71 and the stationary contact 3 separate, the electric arc generated will be preferentially drawn towards the center line L of the vertical plate 41 before entering the arc-extinguishing chamber. Therefore, within a certain range, the larger the front-to-back width d of the vertical plate 41, and the farther the center line L of the vertical plate 41 is from the center of the stationary contact 3, the more beneficial it is to enhance the arc-blowing force of the magnetic conductor 4, and increase the speed at which the electric arc enters the arc-extinguishing chamber and the speed at which the electric arc extinguishes. Conversely, if the front-to-back width d of the vertical plate 41 is very small, such that the center line L of the vertical plate 41 is behind the center of the stationary contact 3, the burning time of the electric arc will be prolonged during the process of the electric arc being drawn towards the center line L of the vertical plate 41 and then absorbed by the arc-extinguishing chamber, increasing the burn-out of the stationary contact 3 and the moving contact 71, which may lead to the failure of the breaking test.

[0066] As can be seen from the above, by improving the structure of the contact base 1, the arc-inducing component 2, and the magnetic conductor 4, this utility model increases the electric repulsive force of the contact assembly without occupying more installation space, thereby improving the breaking speed of the stationary contact 3 and the moving contact 71. It also simplifies the assembly structure of the stationary contact 100, eliminating the need for additional fasteners such as rivets, and thus completing the limiting and fixing of the arc-inducing component 2 and the magnetic conductor 4 on the contact base 1, thereby improving assembly efficiency and reducing costs.

[0067] like Figure 10-11 As shown, this utility model also provides a circuit breaker, which includes a base 8. The base 8 has two base side walls 81 located on the left and right sides respectively. The base 8 is also provided with a plurality of partitions 82 distributed at intervals in the left and right direction. The plurality of partitions 82 divide the space between the two base side walls 81 into a plurality of cavities 84. Each cavity 84 is equipped with a contact assembly 200, an arc-extinguishing chamber 5 disposed above the arc-starting member 2, and a protective assembly 6 disposed between the stationary contact 100 and the arc-extinguishing chamber 5.

[0068] Specifically, such as Figure 12 As shown, each cavity 84 has a slot 841 and a groove 821 on its left and right side walls. The groove 821 is an upward-facing, U-shaped structure, defined by a first groove post 8211 at the front, a second groove post 8212 at the rear, and a bottom surface 8213. A recess 8214 connects to the center of the bottom surface 8213. Additionally, each cavity 84 has two baffles 83 distributed along the left-right direction at its rear, with an opening between the two baffles 83 for the moving contact 7 to enter the cavity 84. Each baffle 83 also has a notch 831 at its top. The stationary contact 100 is fixed in the cavity 84 by fasteners and fixing holes on the fixing plate 11.

[0069] like Figure 13-15 As shown, the arc-extinguishing chamber 5 includes two side plates 51 and multiple arc-extinguishing grid plates 52 arranged between the two side plates 51 from top to bottom. When the moving contact 71 separates from the stationary contact 3, the electric arc generated will be driven by the magnetic field force and quickly enter the arc-extinguishing chamber 5 through the arc-starting angle 21. The multiple arc-extinguishing grid plates 52 will cut the electric arc into multiple small arc segments, so that the arc is extinguished as soon as possible, thus achieving arc extinguishing. The multiple arc-extinguishing grid plates 52 include a first arc-extinguishing grid plate 521 located at the bottom and a second arc-extinguishing grid plate 522 located adjacent to the first arc-extinguishing grid plate 521.

[0070] Specifically, each side plate 51 includes a bottom surface 511, a rear side surface 512, a top surface 513, and a front side surface 514. The two side plates 51 are correspondingly inserted into the two slots 821 of the cavity 84. The front side surface 514 of the side plate is attached to the first slot post 8211, the distance between the rear side surface 512 and the second slot post 8212 is 0.2mm, the bottom surface 511 of the side plate is attached to the bottom surface 8213 of the slot, and the top surface 513 of the side plate is pressed and fitted by the cover plate of the base 8.

[0071] like Figure 13-14 , Figure 16-18 As shown, the protective assembly 6 includes an arc-blocking plate 61 and two protective covers 63 connected to the arc-blocking plate 61. The arc-blocking plate 61 extends upwards from the top of the fixed plate 11 to a height higher than the top of the arc-extinguishing chamber 5, serving to block the arc. The arc-blocking plate 61 can be inserted into two slots 841 in the cavity 84. The two protective covers 63 are spaced apart and cover the top of the stationary contact 100, separating the stationary contact 100 from the arc-extinguishing chamber 5. The stationary contact 3 and the moving contact 7 are positioned between the two protective covers 63. Each protective cover 63 also has a protective groove 632 at its bottom. The two protective grooves 632 of the two protective covers 63 correspond one-to-one with the two vertical plates 41. The protective grooves 632 are fitted over the corresponding vertical plates 41, separating the vertical plates 41 from the stationary contact 3, thereby preventing arc burn-in, protecting the magnetic conductor 4 from arc burning, and ensuring that the arc can quickly enter the arc-extinguishing chamber 5 under the guidance of the arc-starting angle 21. Furthermore, an inclined guide surface 633 is provided near the opening of each protective groove 632, which helps guide the vertical plate 41 into the protective groove 632. The bottoms of the two protective covers 63 are connected by an isolation bracket 64, which can prevent the moving contact 7 and the stationary contact 100 from short-circuiting.

[0072] Specifically, the lateral spacing between the two protective covers 63 decreases sequentially from front to back, which helps to generate a pressure difference and drive the arc to transfer to the arc-extinguishing chamber 5 more quickly. Each protective cover 63 is connected to the arc-isolating plate 61 via a housing 62. The housing 62 is located between the stationary contact 100 and the arc-extinguishing chamber 5, and also serves to separate the stationary contact 100 and the arc-extinguishing chamber 5, increasing the creepage distance and electrical clearance between them, and preventing breakdown short circuits along the route of stationary contact 100, arc-extinguishing chamber 5, and moving contact 7 during dielectric performance testing. A second gap 622 is provided between the two housings 62, and the arc-initiating angle 21 is exposed in the second gap 622. When the stationary contact 3 and the moving contact 71 separate, the arc generated will move from between the two protective covers 63 to the arc-initiating angle 21 located in the second gap 622, and enter the arc-extinguishing chamber 5 under the guidance of the arc-initiating angle 21. Simultaneously, during the process of the moving contact 71 separating from the stationary contact 3 to generate an electric arc, the heat generated causes the surrounding air to expand due to heat. The second gap 622 facilitates the rapid discharge of this expanded air. In addition, each housing 62 is provided with an outwardly protruding part 621, which can be inserted into the groove 8214 and abuts against the bottom surface 511 of the side plate. Each protective cover 63 is provided with a locking block 631 for insertion into the notch 831. This arrangement can fix the relative position of the protective cover 63 and avoid the problem of the protective cover 63 shrinking inward and jamming the moving contact 7 due to high temperature during the short circuit test. The isolation bracket 64 is provided with a downwardly extending limiting block 641, which is used to limit the second connection part 122 to ensure that there is sufficient creepage distance and electrical clearance between the stationary contact 100 and the moving contact 7.

[0073] like Figures 19-20 As shown, the moving contact 7 includes a conductive rod 72. A moving contact 71 is provided at the end of the conductive rod 72 near the stationary contact 100. A first inclined surface 721 and a second inclined surface 722 are also provided on the front side of this end. The connection between the first inclined surface 721 and the second inclined surface 722 is a guide edge 723 protruding forward. Simultaneously, the second inclined surface 722 also includes a lower side edge 7221 parallel to the guide edge 723, adjacent to the moving contact 71. When the moving contact 71 contacts the stationary contact 3, the guide edge 723 is located between the first arc-extinguishing grid plate 521 and the second arc-extinguishing grid plate 522. When the moving contact 71 separates from the stationary contact 3, the arc generated between them can quickly move from the lower side edge 7221 to the guide edge 723. At this time, the first arc-extinguishing grid plate 521 can quickly cut the arc, thereby improving the arc-extinguishing efficiency of the arc-extinguishing chamber 5. Furthermore, regardless of whether the moving contact 71 is in contact with or separated from the stationary contact 3, the distance between the guide edge 723 and the nearest arc-extinguishing grid plate 52 is 2.1-2.3mm, and this distance provides the best arc-initiating effect.

[0074] The assembly sequence of the circuit breaker is as follows: first, the stationary contact 100 is installed into the cavity 84, then the protective component 6 is installed above the stationary contact 100, then the moving contact 7 is installed, so that the end of the moving contact 7 is located between the two protective covers 63, and finally the arc-extinguishing chamber 5 is installed.

[0075] Example 2

[0076] Embodiment 2 provides a contact assembly that further improves the structure of the fixing plate 11, the support plate 13 and the magnetic conductor 4 based on the contact assembly in Embodiment 1.

[0077] like Figures 21-24 and Figure 26 As shown, the fixing plate 11 is provided with a first vent 111 communicating with the first gap 161, which helps to discharge arc gas. At the bottom of the support plate 13, positioning posts 136 and cross-shaped reinforcing ribs 138 are respectively provided. The reinforcing ribs 138 are located directly below the stationary contact 3, which helps to strengthen the structural strength of the stationary contact mounting location and prevent deformation of the support plate 13. Specifically, the reinforcing ribs 138 are formed by stamping the bottom of the support plate 13, thus forming a recess 137 around the reinforcing ribs 138. The material originally in the recess 137 has been compressed and concentrated in the center, forming a denser reinforcing rib 138. A positioning hole 421 is also provided on the horizontal plate 42 of the magnetic conductor 4 to cooperate with the positioning post 136. The cooperation between the positioning post 136 and the positioning hole 421 can further limit the installation position of the magnetic conductor 4 relative to the bracket plate 13, so that the positions of the two vertical plates 41 of the magnetic conductor 4 relative to the stationary contact 3 are fixed, ensuring that the magnetic field is more concentrated in the area where the stationary contact 3 is located to increase the arc blowing force.

[0078] Furthermore, a support pad 135 for mounting the stationary contact 3 is provided on the top of the bracket plate 13. By reducing the overall thickness of the mounting frame 12 and the bracket plate 13 and saving the installation space of the contact seat 1, the stationary contact 3 can be kept at the original height by adjusting the height of the support pad 135, ensuring smooth contact between the stationary contact 3 and the moving contact.

[0079] Embodiment 2 also provides a circuit breaker equipped with the above-mentioned contact assembly, and based on the circuit breaker in Embodiment 1, the structure of the arc-extinguishing chamber 5 and the protective assembly 6 has been further improved.

[0080] like Figure 25 As shown, each side plate 51 of the arc-extinguishing chamber 5 is also provided with a second exhaust port 515, which helps to discharge the arc gas in the arc-extinguishing chamber 5.

[0081] like Figures 25 to 29As shown, the protective component 6 also includes an arc-damping plate 61, two protective covers 63, and a housing 62 for connecting each protective cover 63 and the arc-damping plate 61. The stationary contact 3 and the moving contact 7 are disposed between the two protective covers 63. The difference between the protective cover 63 and the one in Embodiment 1 is that, in addition to a protective groove 632 for fitting over the vertical plate 41, each protective cover 63 has a mounting hook 637 at its bottom. The two mounting hooks 637 of the two protective covers 63 are correspondingly set with the two receiving grooves 123 of the contact seat 1. Each mounting hook 637 is engaged at the rear end of its corresponding receiving groove 123, thereby achieving the limited installation of the protective component 6 and the contact seat 1.

[0082] Furthermore, in addition to the mounting hook 637, each protective cover 63 also includes a limiting grid 634 and a partition plate 635 arranged sequentially from bottom to top. The left and right ends of the arc-extinguishing grid 52 of the arc-extinguishing chamber 5 are installed on the outside of the limiting grid 634 and the partition plate 635, and the protective groove 632 is opened below the limiting grid 634. The limiting grid 634 can position the arc-extinguishing grid 52, facilitate the installation of the arc-extinguishing chamber 5, and prevent the arc-extinguishing chamber 5 from swaying left and right. The left and right distance between the two partition plates 635 decreases from front to back, which helps to generate a pressure difference and drive the arc to transfer to the arc-extinguishing chamber 5 more quickly. At the same time, the two partition plates 635 can separate the left and right ends of the arc-extinguishing grid 52 from the stationary contact 3 and the moving contact, which can prevent the arc from burning on the side and ensure that the arc generated when the stationary contact 3 and the moving contact 71 are separated will move from between the two protective covers 63 to the arc-starting angle 21 and enter the arc-extinguishing chamber 5 under the guidance of the arc-starting angle 21. Furthermore, such as Figure 28 As shown, in Embodiment 2, each protective cover 63 has a locking block 631 on its top for engaging with the notch of the base, and a material reduction groove 636. The material reduction groove 636 helps to reduce the overall weight of the protective component 6, thereby achieving lightweighting of the protective component 6 and saving production costs.

[0083] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A contact assembly comprising a stationary contact (100) and a moving contact (7), characterized in that, The stationary contact (100) includes: The contact base (1) includes a fixing plate (11) and a mounting frame (12). The mounting frame (12) includes two first connecting parts (121). The first ends of the two first connecting parts (121) are connected to the fixing plate (11), and the second ends of the two first connecting parts (121) are connected through a second connecting part (122). A support plate (13) is also connected to the second connecting part (122). The support plate (13) is located between the two first connecting parts (121), and a receiving groove (123) is formed between each first connecting part (121) and the support plate (13). A stationary contact (3) is provided on the bracket plate (13); The arc-starting component (2) includes two third connecting parts (22), each of which is located directly above the first connecting part (121); the first ends of the two third connecting parts (22) are connected by an inclined arc-starting angle (21), and the second ends of each are connected to a mounting part (23), which is connected to the second end of the first connecting part (121) located directly below it; a gap (15) extending along the extension direction of the third connecting part (22) is provided between the third connecting part (22) and the first connecting part (121); The magnetic conductor (4) includes two vertical plates (41) connected in a U-shape and a horizontal plate (42). Each receiving slot (123) accommodates one of the vertical plates (41). The horizontal plate (42) is located below the support plate (13). The stationary contact (3) is located between the two vertical plates (41). The magnetic conductor (4) is respectively limited and connected to the mounting frame (12) and the arc-drawing component (2).

2. The contact assembly according to claim 1, characterized in that, The second end of the first connecting part (121) is provided with a riveting protrusion (14), and the mounting part (23) is provided with a countersunk hole (24) for riveting with the riveting protrusion (14).

3. The contact assembly according to claim 1, characterized in that, The bracket plate (13) is provided with a limiting groove (131) at one end away from the second connecting part (122), and the vertical plate (41) is provided with a limiting hook (43) that cooperates with the limiting groove (131).

4. The contact assembly according to claim 3, characterized in that, The inner side of the third connecting part (22) is provided with a limiting protrusion (221) for abutting against the vertical plate (41), and the arc corner (21) is provided with a limiting surface (211) for abutting against the vertical plate (41).

5. The contact assembly according to claim 1, characterized in that, The horizontal plate (42) is provided with a positioning hole (421), and the bottom of the support plate (13) is provided with a positioning post (136) that is inserted into the positioning hole (421).

6. The contact assembly according to claim 1, characterized in that, The side of the stationary contact (3) near the second connecting part (122) is flush with the side of the vertical plate (41) near the second connecting part (122).

7. The contact assembly according to claim 1, characterized in that, The fixing plate (11) is provided with a first exhaust hole (111).

8. The contact assembly according to claim 1, characterized in that, The bottom of the support plate (13) is provided with a reinforcing rib (138), which is located directly below the stationary contact (3).

9. A circuit breaker, characterized in that, Includes the contact assembly as described in any one of claims 1-8.

10. The circuit breaker according to claim 9, characterized in that, It also includes a base (8) in which the contact assembly, an arc-extinguishing chamber (5) disposed above the arc-starting member (2), and a protective assembly (6) disposed between the arc-extinguishing chamber (5) and the stationary contact (100) are installed.

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