A fast arc extinguishing and high breaking miniature circuit breaker

Abstract

The present invention relates to a fast arc extinguishing, high-breaking miniature circuit breaker, comprising a housing, a working chamber, a tripping coil assembly, a tripping mechanism, a moving contact, a static contact, and an arc extinguishing mechanism disposed within the working chamber. The tripping coil assembly comprises a magnetic yoke, the magnetic yoke comprising a mounting frame and a mounting portion, the mounting portion being disposed at one end of the magnetic yoke corresponding to the moving contact, one end of the static contact being connected to the upper end of the mounting portion, and the other end being bent downward to form a contact portion that mates with the moving contact. The arc extinguishing mechanism comprises an arc extinguishing hood, a PTC assembly, and an arc extinguishing grid assembly, the arc extinguishing hood comprising a mounting chamber and an arc extinguishing chamber, an arc striking plate disposed at the lower end of the mounting portion, and an arc striking plate comprising an L-shaped connecting portion and an arc-shaped arc striking portion, one end of the L-shaped connecting portion being connected to the lower end of the mounting portion, and the other end being bent close to the contact portion, the upper end of the arc-shaped arc striking portion being close to the lower end of the contact portion, and the lower end of the arc-shaped arc striking portion extending toward the arc extinguishing chamber. By adopting the above-mentioned technical solution, arc extinguishing time is accelerated, breaking capacity is improved, and contacts and PTC components are protected.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage electrical appliances, and in particular to a miniature circuit breaker with fast arc extinguishing and high breaking capacity. Background Art

[0002] Existing miniature circuit breakers consist of an operating system, arc extinguishing system, tripping mechanism, contact system, housing, and operating handle. Their main contacts are closed manually or electrically. After the main contacts close, a free-tripping mechanism locks them in the closed position. The coil of the overcurrent release and the thermal element of the thermal release are connected in series with the main circuit, while the coil of the undervoltage release is connected in parallel with the power supply. When a short circuit or severe overload occurs in the circuit, the armature of the overcurrent release engages, actuating the free-tripping mechanism and disconnecting the main circuit with the main contacts. When the circuit is overloaded, the thermal element of the thermal release heats up, bending the bimetallic strip and actuating the free-tripping mechanism. When the circuit undervoltage occurs, the armature of the undervoltage release releases, also actuating the free-tripping mechanism.

[0003] As the demand for electricity in production and daily life continues to increase, higher requirements are being placed on power supply safety, reliability, and intelligence. Therefore, miniature circuit breakers have high application value. However, if the arc is not quickly drawn into the arc extinguishing chamber during the opening and closing process of the circuit breaker contacts, it will easily cause the circuit breaker contacts to burn, affecting the circuit breaker's segmentation capability and leading to a decline in product performance. Summary of the Invention

[0004] In summary, in order to overcome the deficiencies of the prior art, the present invention provides a miniature circuit breaker with fast arc extinguishing and high breaking capacity.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: a fast arc extinguishing high breaking miniature circuit breaker, comprising a housing, the housing comprising a working chamber, the working chamber being provided with a trip coil assembly, a trip mechanism, a moving contact, a static contact and an arc extinguishing mechanism, the trip coil mechanism comprising a magnetic yoke and a trip coil assembly, the magnetic yoke comprising a mounting frame for mounting the trip coil assembly and a mounting portion arranged on one side of the mounting frame, the mounting portion being arranged at one end of the magnetic yoke corresponding to the moving contact, one end of the static contact being connected to the upper end of the mounting portion, and the other end being bent toward A contact portion is formed below to cooperate with the moving contact, and the arc extinguishing mechanism includes an arc extinguishing cover, a PTC component and an arc extinguishing grid component. The arc extinguishing cover includes a mounting cavity for installing the PTC component and an arc extinguishing cavity for installing the arc extinguishing grid assembly. An arc-striking piece is provided at the lower end of the mounting portion, and the arc-striking piece includes an L-shaped connecting portion and an arc-shaped arc-striking portion. One end of the L-shaped connecting portion is connected to the lower end of the mounting portion, and the other end is bent close to the contact portion. The upper end of the arc-shaped arc-striking portion is close to the lower end of the contact portion, and the lower end of the arc-shaped arc-striking portion extends toward the arc extinguishing cavity.

[0006] By adopting the above technical solution, the arc-striking piece is arranged between the static contact and the arc extinguishing chamber, the upper end of the arc-shaped arc-striking portion is close to the lower end of the contact portion, and the lower end of the arc-shaped arc-striking portion extends toward the arc extinguishing chamber, so as to quickly lead the arc generated by the contact separation to the arc extinguishing chamber, accelerate the arc extinguishing time, improve the breaking capacity, protect the contact, and prevent the arc from entering the installation cavity, thereby protecting the PTC component; at the same time, due to the use of the PTC component in the arc extinguishing mechanism, the resistance of the PTC component is very small under normal circumstances, generally a few ohms to tens of ohms. When a large short-circuit current passes through, the instantaneous resistance increases exponentially, and the greater the short-circuit current, the shorter the reaction time. The short-circuit current of 50KA can be clamped below 1KA within 0.5ms, further improving the breaking capacity. The structure is reasonable in design, simple in structure, easy to manufacture, reliable in performance, low in production cost and good in practicality.

[0007] The present invention is further provided with: a first mounting protrusion for mounting a static contact is provided at the upper end of the mounting portion, a mounting recess for mounting an arc-striking piece is provided at the lower end of the mounting portion, a mounting through hole adapted to the position of the static contact corresponding to the first mounting protrusion is provided, a second mounting protrusion adapted to the position of the arc-striking piece corresponding to the mounting recess is provided, and a receiving portion for limiting the L-shaped connecting portion is provided below the shell corresponding to the L-shaped connecting portion and one end of the mounting portion.

[0008] By adopting the above technical solution, the connection between the three is made more stable and not easy to deviate, and at the same time it plays a positioning role, making installation convenient and quick.

[0009] The present invention further provides: an auxiliary switch is arranged between the arc extinguishing mechanism and the moving contact, the arc extinguishing mechanism includes an arc extinguishing cover, a PTC component and an arc extinguishing grid component, the auxiliary switch includes a conductive plate connected to the PTC component and an auxiliary contact connected to the moving contact, the conductive plate is arranged on the side of the PTC component corresponding to the moving contact, the auxiliary contact is arranged between the conductive plate and the moving contact and is arranged perpendicular to the conductive plate, and the other end of the auxiliary contact relative to the moving contact is in sliding contact or disconnected with the conductive plate.

[0010] By adopting the above technical solution, when the moving contact moves toward the static contact, the auxiliary contact first contacts the conductive plate as the moving contact swings, forming a closed auxiliary series circuit until the moving and static contacts contact to form a parallel circuit. When a short circuit occurs, the trip coil assembly cooperates with the trip mechanism to disconnect the moving contact from the static contact. At this time, the auxiliary contact still maintains a physical connection with the conductive plate for a certain period of time. At this time, the current can only pass through the auxiliary contact, the conductive plate and the series PTC component. The temperature of the PTC component rises sharply. Due to the PTC component effect, the PTC component limits the short-circuit current and consumes most of the breaking energy. Finally, The auxiliary contact swings with the moving contact until it is disconnected from the conductive plate. This technical solution adopts a double-contact design, which, in conjunction with the conductive plate design, greatly improves the breaking capacity of the miniature circuit breaker. At the same time, the auxiliary contact is arranged vertically to the conductive plate, and the end of the auxiliary contact slides along the surface of the conductive plate and is slidably connected to the conductive plate. Compared with the spring clip arranged between the moving and static contacts, the moving contact drives the spring clip to bend and connect, which is more durable and has a longer service life. Compared with the auxiliary contact and the conductive spring clip arranged above and below, the auxiliary contact is slidably connected to the upper end face or lower end face of the conductive plate. In this technical solution, the stability of the auxiliary switch connection is higher.

[0011] The present invention is further provided that: the installation cavity is opened in the direction corresponding to the conductive plate, and a first spring piece and a second spring piece are respectively provided on both sides of the installation cavity corresponding to the opening direction. The first spring piece is provided on one side of the PTC component corresponding to the conductive plate and is integrally connected to the conductive plate, and the second spring piece is provided on the other side of the PTC component and is elastically connected to the trip coil component.

[0012] By adopting the above technical solution, the PTC component is positioned by the first spring piece and the second spring piece, and at the same time, a sliding connection with the auxiliary contact is achieved through the first spring piece, and an elastic connection is achieved with the tripping coil assembly through the second spring piece, thereby realizing the series connection of the auxiliary circuit. At the same time, the arc extinguishing grid and the PTC component are modularly assembled through the integrally formed arc extinguishing cover, which is convenient and quick to install.

[0013] The present invention further provides that: the PTC component includes a contact piece and a PTC element arranged on both sides of the contact piece, and mounting slots with the same opening direction are respectively provided on both sides of the arc extinguishing cover corresponding to the opening direction, and a through hole connected to the mounting cavity is provided on one side of the mounting slot corresponding to the mounting cavity, the first spring piece includes a mounting card portion adapted to the mounting slot, a card portion extending through the through hole for connecting to the PTC element, and a first connecting portion for connecting to the conductive plate, and the second spring piece includes a mounting card portion adapted to the mounting slot, a card portion extending through the through hole for connecting to the PTC element, and a second connecting portion for connecting to the tripping coil assembly.

[0014] By adopting the above technical solution, two PTC elements are used, which simplifies the structure and reduces the size of the module compared to multiple PTC elements. It can be used in miniature circuit breakers, and the structure is more reasonable. Different types of PTC elements can be used according to needs to achieve different current limiting capabilities; an installation slot is provided, and the first spring piece and the second spring piece are installed by a card-setting method, which is convenient for disassembly and replacement compared to welding, thereby increasing the service life of the product, and is convenient and quick to install, and the setting of the installation slot improves the stability of the first spring piece and the second spring piece; a card part is provided, and the card part is elastic. The PTC component is connected to the card parts on both sides, which plays a positioning role for the PTC component and improves the stability of the PTC component; the first spring piece and the conductive plate are connected to the tripping coil component respectively through the first connecting part and the second connecting part. The conductive plate can be formed as one piece without the need for additional connectors, which facilitates the integration and modularization of the arc extinguishing mechanism, improves stability, and facilitates installation.

[0015] The present invention further provides that: a slot for clamping the contact piece is provided in the middle of the installation cavity.

[0016] By adopting the above technical solution and cooperating with the clamping parts on both sides, the installation stability of the PTC component is further improved.

[0017] The present invention further provides: an inlet cavity and an outlet cavity are respectively provided on both sides of the shell, a bimetallic strip is provided in the outlet cavity, the bimetallic strip is connected to the arc striking plate, and the arc striking plate includes a connecting clamp portion clamped under the arc extinguishing cover, an arc-shaped extension portion extending upward toward the moving contact, and a third connecting portion connected to the bimetallic strip.

[0018] By adopting the above technical solution, the arc-shaped extension portion quickly introduces the arc generated by the separation of the moving contact into the arc extinguishing cavity, extinguishes the arc through the arc extinguishing grid assembly, and cooperates with the arc striking piece to achieve double arc striking, which greatly improves the arc extinguishing effect.

[0019] The present invention further provides that: the first connecting portion extends out of the arc extinguishing cover from the opening of the mounting slot, an arc isolation plate is provided between the arc-shaped extension portion and the first connecting portion, and a sliding groove for sliding connection between the auxiliary contact and the conductive plate is provided at the position of the arc isolation plate corresponding to the conductive plate.

[0020] By adopting the above technical solution, an arc isolation plate is provided to prevent the arc generated by the moving contact from affecting the auxiliary circuit, and a sliding groove is provided, in which the auxiliary contact is slidably connected to the conductive plate to achieve arc-free disconnection.

[0021] The present invention further provides that: a mounting hole is provided on the arc isolation plate, and a positioning column adapted to the mounting hole is provided at a position corresponding to the mounting hole in the shell.

[0022] By adopting the above technical solution, the arc isolation plate is easily installed, and the installation accuracy and stability of the arc isolation plate are improved.

[0023] The present invention further provides that: the first spring piece and the conductive plate are integrally formed, and a limiting portion for limiting the position of the conductive plate is provided on a side of the arc isolation plate corresponding to the conductive plate.

[0024] By adopting the above technical solution, one end of the conductive plate is connected to the first spring sheet, and the other end is against the limit part. The arc isolation plate is positioned and connected to the shell through the positioning column, so that the conductive plate is accurately installed and accurately matched with the sliding groove.

[0025] The present invention further provides: the tripping coil assembly includes an iron core sleeve and a coil, the iron core sleeve is provided with a static iron core on one side corresponding to the moving contact, and a moving iron core is provided on the other side, the iron core sleeve is hollow, the moving iron core drives the push rod to slide along the inner wall of the iron core sleeve, the static iron core is provided with a movable hole for the push rod to move, and the static contact is provided on the side of the magnetic yoke corresponding to the moving contact.

[0026] By adopting the above technical solution, when the main circuit is short-circuited, the large current causes the coil to generate a magnetic field, the moving iron core drives the ejector rod to be pushed out toward the static iron core, and drives the tripping mechanism to realize the tripping of the moving contact and the disconnection of the static contact.

[0027] The present invention further provides that: the second connecting portion is provided between the magnetic yoke and the arc extinguishing cover, the second connecting portion is integrally provided with an arched connecting point close to the magnetic yoke, and the connecting point is in elastic contact with the magnetic yoke.

[0028] By adopting the above technical solution, the arc extinguishing cover is easy to install and clamp, with elastic contact, more reasonable setting and reliable operation.

[0029] The present invention further provides that: a heat dissipation hole is provided on the other side of the arc extinguishing cover relative to the opening, and the heat dissipation hole is spaced apart from the inner wall of the working chamber.

[0030] By adopting the above technical solution, since the PTC component heats up quickly during operation, heat dissipation holes are provided to improve heat dissipation performance and extend service life. The heat dissipation holes are spaced apart from the inner wall of the working chamber to further improve heat dissipation performance.

[0031] The specific implementation of the present invention will be described below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a front view of the internal structure of an embodiment of the present invention;

[0033] Figure 2 The internal structure of the embodiment of the present invention is three-dimensional Figure 1 ;

[0034] Figure 3 The internal structure of the embodiment of the present invention is three-dimensional Figure 2 ;

[0035] Figure 4 A perspective view of a partial structure of an embodiment of the present invention;

[0036] Figure 5 for Figure 4 A magnified view of part A;

[0037] Figure 6 The local structure of the embodiment of the present invention is three-dimensional Figure 1 ;

[0038] Figure 7 The local structure of the embodiment of the present invention is three-dimensional Figure 2 ;

[0039] Figure markings: 1. Housing, 11. Working chamber, 12. Inlet chamber, 13. Outlet chamber, 14. Positioning column, 15. Receiving portion, 2. Tripping coil mechanism, 21. Yoke, 211. Mounting frame, 212. Mounting portion, 2121. First mounting protrusion, 2122. Mounting recess, 22. Tripping coil assembly, 221. Core sleeve, 222. Coil, 223. Static core, 2231. Movable hole, 224. Moving core, 225. Push rod, 3. Tripping mechanism, 4. Moving contact, 5. Static contact, 51. Contact portion, 52. Mounting through hole, 6. Arc extinguishing mechanism, 61. Arc extinguishing cover, 611. Mounting chamber, 6111. Heat dissipation hole, 6112. Card slot, 612. Arc extinguishing chamber, 613. Mounting slot , 6131. ​​Through hole, 62. PTC assembly, 621. First spring piece, 6211. Mounting card portion, 6212. Card portion, 6213. First connecting portion, 622. Second spring piece, 6221. Second connecting portion, 6222. Connection point, 623. Contact piece, 624. PTC element, 63. Arc extinguishing grid assembly, 64. Arc striking piece, 641. L-shaped connecting portion, 642. Arc-shaped arc striking portion, 643. Second mounting protrusion, 7. Auxiliary switch, 71. Conductive plate, 72. Auxiliary contact, 8. Bimetallic strip, 9. Arc striking plate, 91. Connecting card portion, 92. Arc-shaped extension portion, 93. Third connecting portion, 10. Arc isolation plate, 101. Sliding groove, 102. Mounting hole, 103. Limiting portion. DETAILED DESCRIPTION

[0040] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

[0041] See attached Figure 1-7, a fast arc extinguishing high breaking miniature circuit breaker disclosed in this embodiment includes a housing 1, the housing 1 includes a working chamber 11, and the working chamber 11 is provided with a tripping coil mechanism 2, a tripping mechanism 3, a moving contact 4, a static contact 5 and an arc extinguishing mechanism 6, the tripping coil mechanism 2 includes a yoke 21 and a tripping coil assembly 22, the yoke 21 includes a mounting frame 211 for mounting the tripping coil assembly 22 and a mounting portion 212 provided on one side of the mounting frame 211, the mounting portion 212 is provided at one end of the yoke 21 corresponding to the moving contact 4, one end of the static contact 5 is connected to the upper end of the mounting portion 212, and the other end is bent downward to form a connection with the moving contact 4. The contact portion 51, the arc extinguishing mechanism 6 includes an arc extinguishing cover 61, a PTC component 62 and an arc extinguishing grid component 63, the arc extinguishing cover 61 includes a mounting cavity 611 for mounting the PTC component 62 and an arc extinguishing cavity 612 for mounting the arc extinguishing grid component 63, the lower end of the mounting portion 212 is provided with an arc-striking piece 64, the arc-striking piece 64 includes an L-shaped connecting portion 641 and an arc-shaped arc-striking portion 642, one end of the L-shaped connecting portion 641 is connected to the lower end of the mounting portion 212, and the other end is bent close to the contact portion 51, the upper end of the arc-shaped arc-striking portion 642 is close to the lower end of the contact portion 51, and the lower end of the arc-shaped arc-striking portion 642 extends toward the arc extinguishing cavity 612.

[0042] This embodiment is further configured as follows: a first mounting protrusion 2121 for mounting a static contact 5 is provided at the upper end of the mounting portion 212, a mounting recess 2122 for mounting an arc-striking piece 64 is provided at the lower end of the mounting portion 212, a mounting through hole 52 adapted to the position of the static contact 5 corresponding to the first mounting protrusion 2121 is provided, a second mounting protrusion 643 adapted to the position of the arc-striking piece 64 corresponding to the mounting recess 2122 is provided, and a receiving portion 15 for limiting the L-shaped connecting portion 641 is provided below the housing 1 corresponding to the L-shaped connecting portion 641 and one end of the mounting portion 212.

[0043] This embodiment is further configured as follows: an auxiliary switch 7 is provided between the arc extinguishing mechanism 6 and the moving contact 4, the auxiliary switch 7 includes a conductive plate 71 connected to the PTC component 62 and an auxiliary contact 72 connected to the moving contact 4, the conductive plate 71 is provided on the side of the PTC component 62 corresponding to the moving contact 4, the auxiliary contact 72 is provided between the conductive plate 71 and the moving contact 4 and is provided perpendicular to the conductive plate 71, and the other end of the auxiliary contact 72 relative to the moving contact 4 is in sliding contact or disconnection with the conductive plate 71.

[0044] This embodiment is further configured as follows: the installation cavity 611 is opened in the direction corresponding to the conductive plate 71, and a first spring piece 621 and a second spring piece 622 are respectively provided on both sides of the installation cavity 611 corresponding to the opening direction. The first spring piece 621 is provided on one side of the PTC component 62 corresponding to the conductive plate 71 and is integrally connected to the conductive plate 71, and the second spring piece 622 is provided on the other side of the PTC component 62 and is elastically connected to the trip coil component 22.

[0045] This embodiment further provides that: the PTC assembly 62 includes a contact piece 623 and a PTC element 624 arranged on both sides of the contact piece 623; the arc extinguishing cover 61 is provided with mounting slots 613 with the same opening direction on both sides of the corresponding opening direction; the mounting slot 613 is provided with a through hole 6131 connected to the mounting cavity 611 on one side corresponding to the mounting cavity 611; the first spring piece 621 includes a mounting clamping portion 6211 adapted to the mounting slot 613, and a through hole 6131 extending out of the through hole 6131 for connecting the PTC element 62 4 and a first connection portion 6213 for connecting to the conductive plate 71, the second spring piece 622 includes a mounting clamping portion 6211 adapted to the mounting slot 613, a clamping portion 6212 extending from a through hole 6131 for connecting to a PTC element 624, and a second connection portion 6221 for connecting to the tripping coil assembly 22, and a socket for allowing the second connection portion 6221 to extend out of the arc extinguishing chamber 612 is provided above the mounting slot 613 corresponding to the second connection portion, and the socket is provided at the open end of the mounting slot 613.

[0046] This embodiment further provides that: a clamping groove 6112 for clamping the contact piece is provided in the middle of the installation cavity 611.

[0047] This embodiment is further configured as follows: an inlet cavity 12 and an outlet cavity 13 are respectively provided on both sides of the shell 1, a bimetallic strip 8 is provided in the outlet cavity 13, the bimetallic strip 8 is connected to the arc striking plate 9, and the arc striking plate 9 includes a connecting clamp portion 91 clamped under the arc extinguishing cover 61, an arc-shaped extension portion 92 extending upward toward the moving contact 4, and a third connecting portion 93 connected to the bimetallic strip 8.

[0048] This embodiment is further configured as follows: the first connecting portion 6213 extends from the opening of the installation slot 613 to form the arc extinguishing cover 61; an arc isolation plate 10 is provided between the arc-shaped extension portion 92 and the first connecting portion 6213; and a sliding groove 101 is provided on the position of the arc isolation plate 10 corresponding to the conductive plate 71 for sliding connection between the auxiliary contact 72 and the conductive plate 71.

[0049] This embodiment further provides that: a mounting hole 102 is provided on the arc isolation plate 10 , and a positioning column 14 adapted to the mounting hole 102 is provided at a position corresponding to the mounting hole 102 in the housing 1 .

[0050] This embodiment further provides that: the first spring piece 621 is integrally formed with the conductive plate 71 , and a limiting portion 103 for limiting the position of the conductive plate 71 is provided on a surface of the arc isolation plate 10 corresponding to the conductive plate 71 .

[0051] This embodiment is further configured as follows: the tripping coil assembly 22 includes an iron core sleeve 221 and a coil 222; a static iron core 223 is provided on one side of the iron core sleeve 221 corresponding to the moving contact 4, and a moving iron core 224 is provided on the other side; the iron core sleeve 221 is hollow, and the moving iron core 224 drives the push rod 225 to slide along the inner wall of the iron core sleeve 221; a movable hole 2231 for the push rod 225 to move is provided on the static iron core 223; and the static contact 5 is provided on the side of the yoke 21 corresponding to the moving contact 4.

[0052] This embodiment further provides that: the second connection portion 6221 is provided between the magnetic yoke 21 and the arc extinguishing cover 61 , and the second connection portion 6221 is integrally provided with an arched connection point 6222 near the magnetic yoke 21 , and the connection point 6222 is in elastic contact with the magnetic yoke 21 .

[0053] This embodiment further provides that: a heat dissipation hole 6111 is provided on the other side of the arc extinguishing cover 61 opposite to the opening, and the heat dissipation hole 6111 is spaced apart from the inner wall of the working chamber 11 .

[0054] The above-mentioned “between” does not only refer to directions and positions, but also includes the meaning of the interactions between different parts.

[0055] In the description herein, it should be understood that the terms “center,” “longitudinal,” “lateral,” “up,” “down,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside” and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are merely for the convenience of simplifying the description of the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] Although this article uses more shell 1, working chamber 11, incoming line chamber 12, outgoing line chamber 13, positioning column 14, receiving portion 15, tripping coil mechanism 2, yoke 21, mounting frame 211, mounting portion 212, first mounting protrusion 2121, mounting recess 2122, tripping coil assembly 22, core sleeve 221, coil 222, static iron core 223, movable hole 2231, moving iron core 224, push rod 225, tripping mechanism 3, moving contact 4, static contact 5, contact portion 51, mounting through hole 52, arc extinguishing mechanism 6, arc extinguishing cover 61, mounting chamber 611, heat dissipation hole 6111, card slot 6112, arc extinguishing chamber 612, mounting slot 613, through hole 6131, The following terms are used, but the use of other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

Claims

1. A fast arc extinguishing and high breaking miniature circuit breaker, comprising a housing, the housing including a working chamber, the working chamber being provided with a trip coil mechanism, a trip mechanism, a moving contact, a stationary contact, and an arc extinguishing mechanism, characterized in that: The tripping coil mechanism includes a yoke and a tripping coil assembly. The yoke includes a mounting frame for mounting the tripping coil assembly and a mounting portion provided on one side of the mounting frame. The mounting portion is provided at one end of the yoke corresponding to the moving contact. One end of the static contact is connected to the upper end of the mounting portion, and the other end is bent downward to form a contact portion that cooperates with the moving contact. The arc extinguishing mechanism includes an arc extinguishing cover, a PTC assembly and an arc extinguishing grid assembly. The arc extinguishing cover includes a mounting cavity for mounting the PTC assembly and an arc extinguishing cavity for mounting the arc extinguishing grid assembly. An arc striking piece is provided at the lower end of the mounting portion, and the arc striking piece includes an L-shaped The arc-shaped arc-striking portion includes a connecting portion and an arc-shaped arc-striking portion, one end of the L-shaped connecting portion is connected to the lower end of the mounting portion, and the other end is bent close to the contact portion, the upper end of the arc-shaped arc-striking portion is close to the lower end of the contact portion, and the lower end of the arc-shaped arc-striking portion extends toward the arc extinguishing chamber; an auxiliary switch is provided between the arc extinguishing mechanism and the moving contact, the auxiliary switch includes a conductive plate connected to the PTC component and an auxiliary contact connected to the moving contact, the conductive plate is provided on a side of the PTC component corresponding to the moving contact, and the auxiliary contact is provided between the conductive plate and the moving contact and is in contact with the conductive plate The auxiliary contact is arranged vertically, and the other end of the auxiliary contact relative to the moving contact is in sliding contact with or disconnected from the conductive plate; the installation cavity is opened in the direction corresponding to the conductive plate, and a first spring piece and a second spring piece are respectively provided on both sides of the installation cavity corresponding to the opening direction. The first spring piece is provided on one side of the PTC component corresponding to the conductive plate and is integrally connected to the conductive plate, and the second spring piece is provided on the other side of the PTC component and is elastically connected to the trip coil component; the PTC component includes a contact piece and PTC elements provided on both sides of the contact piece, and the arc extinguishing cover is divided into two parts on both sides of the opening direction. The first spring sheet comprises a mounting clip adapted for use with the mounting slot, a clip extending through the through hole for connecting the PTC element, and a first connection portion for connecting to the conductive plate; the second spring sheet comprises a mounting clip adapted for use with the mounting slot, a clip extending through the through hole for connecting the PTC element, and a second connection portion for connecting to the tripping coil assembly; a heat dissipation hole is provided on the other side of the arc extinguishing cover relative to the opening, and the heat dissipation hole is spaced apart from the inner wall of the working chamber.

2. The fast arc extinguishing and high breaking miniature circuit breaker according to claim 1, characterized in that: An inlet cavity and an outlet cavity are respectively provided on both sides of the shell. A bimetallic strip is provided in the outlet cavity. The bimetallic strip is connected to the arc striking plate. The arc striking plate includes a connecting clamp portion clamped under the arc extinguishing cover, an arc-shaped extension portion extending upward toward the moving contact, and a third connecting portion connected to the bimetallic strip.

3. The fast arc extinguishing high breaking miniature circuit breaker according to claim 2, characterized in that: The first connecting portion extends out of the arc extinguishing cover from the opening of the mounting slot, an arc isolation plate is provided between the arc-shaped extension portion and the first connecting portion, and a sliding groove for sliding connection between the auxiliary contact and the conductive plate is provided at a position of the arc isolation plate corresponding to the conductive plate.

4. The fast arc extinguishing high breaking miniature circuit breaker according to claim 3, characterized in that: The arc isolation plate is provided with a mounting hole, and a positioning column adapted to the mounting hole is provided at a position corresponding to the mounting hole in the shell.

5. The fast arc extinguishing and high breaking miniature circuit breaker according to claim 1, characterized in that: The tripping coil assembly includes an iron core sleeve and a coil. A static iron core is provided on one side of the iron core sleeve corresponding to the moving contact, and a moving iron core is provided on the other side. The iron core sleeve is hollow, and the moving iron core drives the push rod to slide along the inner wall of the iron core sleeve. A movable hole for the push rod to move is provided on the static iron core. The static contact is provided on the side of the magnetic yoke corresponding to the moving contact.

6. The fast arc extinguishing and high breaking miniature circuit breaker according to claim 5, characterized in that: The second connecting portion is provided between the magnetic yoke and the arc extinguishing cover. The second connecting portion is integrally provided with an arched connecting point close to the magnetic yoke, and the connecting point is in elastic contact with the magnetic yoke.

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