Thermomagnetic tripping mechanism of circuit breaker

Abstract

The utility model relates to a thermomagnetic tripping mechanism of a circuit breaker, which comprises a thermal element, a thermomagnetic tripping assembly arranged at one end of the thermal element, and a wiring screw assembly arranged at the other end of the thermal element, the thermomagnetic tripping assembly comprises a magnet yoke, an armature support arranged on the magnet yoke, a bimetallic strip, an armature rotationally arranged on the armature support and a torsional spring arranged between the armature and the armature support, and the magnet yoke and the bimetallic strip are arranged on the two sides of one end of the thermal element respectively. The wiring bolt assembly comprises a fixing plate arranged in the base, a wiring seat arranged on the fixing plate and a wiring bolt, the other end of the thermal element is provided with a kidney-shaped hole, one end of the wiring seat is provided with a positioning convex ring clamped in the kidney-shaped hole, and the positioning convex ring is in limiting fit with the thermal element. And the wiring bolt passes through the waist-shaped hole and is connected to the wiring seat. The utility model has the advantages of simple structure, stable and reliable performance, and convenient assembly.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit breakers, in particular to a thermal magnetic tripping mechanism of a circuit breaker. Background Art

[0002] Molded case circuit breakers are widely used in industries such as industry, agriculture, transportation, mining, civil construction, and national defense. They play a significant role in the transmission and distribution of electricity and the protection of electric motors. They are a widely used and widely used product among low-voltage electrical appliances. A molded case circuit breaker is a switching device that can close, carry, and interrupt current under normal circuit conditions, and can close, carry, and interrupt current under abnormal circuit conditions (including short-circuit conditions) within a specified time. A molded case circuit breaker includes a base, an upper cover, an operating mechanism, a moving contact, a static contact, an arc extinguishing chamber, and a thermal-magnetic tripping mechanism. The structural design of the thermal-magnetic tripping mechanism of existing molded case circuit breakers is relatively complex. During wiring, the torque of the wiring screws causes the thermal element to swing, resulting in the twisting of the bimetallic strip, the yoke, and the armature bracket, which greatly affects the characteristics of the thermal-magnetic tripping mechanism and may even cause the entire thermal-magnetic tripping mechanism to work ineffectively. Furthermore, the thermal-magnetic tripping mechanism of this circuit breaker has the disadvantages of unreliable performance and inconvenient assembly. Summary of the Invention

[0003] The purpose of the utility model is to overcome the defects of the prior art and provide a thermal magnetic tripping mechanism for a circuit breaker with a simple structure, stable and reliable performance, and convenient assembly.

[0004] To achieve the above-mentioned purpose, the utility model adopts a thermal-magnetic tripping mechanism of a circuit breaker, comprising a thermal element, a thermal-magnetic tripping assembly arranged on one end of the thermal element, and a wiring screw assembly arranged on the other end of the thermal element. The thermal-magnetic tripping assembly comprises a yoke, an armature bracket arranged on the yoke, a bimetallic strip, an armature rotatably arranged on the armature bracket, and a torsion spring arranged between the armature and the armature bracket. The yoke and bimetallic strip are respectively arranged on both sides of one end of the thermal element. The wiring screw assembly comprises a fixing plate arranged in the base, a wiring seat arranged on the fixing plate, and a wiring screw. A waist-shaped hole is provided at the other end of the thermal element, and a positioning convex ring is provided on one end of the wiring seat, which is engaged in the waist-shaped hole, and forms a limiting fit between the positioning convex ring and the thermal element. The wiring screw passes through the waist-shaped hole and is connected to the wiring seat.

[0005] The above structure has the following beneficial effects: a positioning collar is provided on the terminal block, which cooperates with the thermal element and serves to position the thermal element. During connection, the torque of the terminal screw does not cause the thermal element to swing, thereby preventing the bimetallic strip, yoke, and armature bracket of the thermal-magnetic tripping mechanism from twisting, thereby enhancing operational reliability. The thermal-magnetic tripping assembly, terminal screw assembly, and thermal element adopt a modular structural design, thereby enabling modular assembly of the thermal-magnetic tripping mechanism. As a result, the thermal-magnetic tripping mechanism of the circuit breaker has the advantages of simple structure, stable and reliable performance, and convenient assembly.

[0006] In particular, one end of the armature is provided with an engaging plate that cooperates with the yoke, and the yoke is provided with an engaging inclined surface that cooperates with the engaging plate. The armature having the engaging plate that cooperates with the yoke can increase the attracting force between the armature and the yoke, thereby improving the operating stability of the thermal magnetic trip mechanism.

[0007] Specifically, the other end of the armature has a trigger arm that engages with the drawbar. The trigger arm has a curved raised portion that engages with the inclined surface of the drawbar. The curved raised portion moves with the trigger arm and abuts against the inclined surface, thereby forming a coordinated connection between the drawbar and the trigger arm. The armature's trigger arm triggers the drawbar via the curved raised portion, preventing the trigger arm and drawbar from becoming stuck, ensuring more reliable transmission between the drawbar and trigger arm and enhancing the flexibility of the tripping action.

[0008] Specifically, the armature bracket is provided with engaging blocks on both sides that mate with the base. The base is provided with engaging grooves that mate with the engaging blocks. The engaging blocks engage within the engaging grooves, forming a snap-fit ​​connection between the armature bracket and the base. This snap-fit ​​connection between the armature bracket and the base enables modular assembly of the thermal-magnetic trip mechanism and the base, making assembly more convenient.

[0009] In particular, the other end of the terminal block is provided with a snap-fitting protrusion that mates with the fixing plate. The fixing plate is provided with a snap-fitting hole, and the snap-fitting protrusion engages within the snap-fitting hole, thereby forming a snap-fit ​​connection between the terminal block and the fixing plate. The snap-fit ​​connection between the terminal block and the fixing plate facilitates assembly of the terminal block and the fixing plate, making assembly more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a cross-sectional view of a circuit breaker according to an embodiment of the present invention.

[0011] Figure 2 This is a three-dimensional diagram of an embodiment of the present utility model.

[0012] Figure 3 This is a diagram of the internal structure of a circuit breaker according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0013] like Figures 1 to 3 As shown, the embodiment of the present invention is a thermal magnetic tripping mechanism of a circuit breaker, comprising a thermal element 10, a thermal magnetic tripping assembly 20 arranged on one end of the thermal element 10, and a terminal screw assembly 30 arranged on the other end of the thermal element 10. The thermal magnetic tripping assembly 20 comprises a yoke 21, an armature bracket 22 arranged on the yoke 21, a bimetallic strip 23, an armature 24 rotatably arranged on the armature bracket 22, and a torsion spring 25 arranged between the armature 24 and the armature bracket 22. The yoke 21, the bimetallic strip 23 Disposed on both sides of one end of the thermal element 10, the terminal screw assembly 30 includes a fixing plate 31 disposed within the base 11, a terminal block 32 disposed on the fixing plate 31, and a terminal screw 33. A waist-shaped hole 101 is provided at the other end of the thermal element 10. A positioning protrusion 321 is provided on one end of the terminal block 32, which engages within the waist-shaped hole 101 and forms a position-limiting fit between the positioning protrusion 321 and the thermal element 10. The terminal screw 33 passes through the waist-shaped hole 101 and is connected to the terminal block 32. An engaging plate 241 is provided on one end of the armature 24, which engages with the yoke 21. The yoke 21 is provided with an engaging inclined surface 211 that engages with the engaging plate 241. The armature's engaging plate, which engages with the yoke, increases the attractive force between the armature and the yoke, thereby improving the operational stability of the thermal magnetic trip mechanism. The other end of the armature 24 has a trigger arm 242 that mates with the drawbar 12. The trigger arm 242 has a curved raised portion 2421 that mates with the inclined surface 121 of the drawbar 12. The curved raised portion 2421 moves with the trigger arm 242 and contacts the inclined surface 121, thereby forming a coordinated connection between the drawbar 12 and the trigger arm 242. The armature's trigger arm triggers the drawbar via the curved raised portion, preventing the trigger arm and drawbar from becoming stuck. This ensures more reliable transmission between the drawbar and trigger arm, and improves the flexibility of the tripping action. The other end of the terminal block 32 is provided with a snap-fitting protrusion 322 that mates with the fixed plate 31. The fixed plate 31 is provided with a snap-fitting hole 311. The snap-fitting protrusion 322 snaps into the snap-fitting hole 311, forming a snap-fitting connection between the terminal block 32 and the fixed plate 31. The terminal block and the fixing plate are connected by a snap-fit ​​method, which facilitates the assembly of the terminal block and the fixing plate and makes the assembly more convenient.

[0014] like Figure 3 As shown, the armature bracket 22 is provided with engaging blocks 221 on both sides that cooperate with the base 11. The base 11 is provided with engaging grooves 111 that cooperate with the engaging blocks 221. The engaging blocks 221 engage in the engaging grooves 111, forming a snap-fit ​​connection between the armature bracket 22 and the base 11. The armature bracket and the base are connected by a snap-fit ​​connection, thereby realizing modular assembly of the thermal-magnetic trip mechanism and the base, making assembly more convenient.

[0015] The terminal block is equipped with a positioning collar that mates with the thermal element and positions it. During wiring, the torque of the terminal screws prevents the thermal element from swinging, thereby preventing the bimetallic strip, yoke, and armature bracket of the thermal-magnetic tripping mechanism from twisting. This improves operational reliability. The thermal-magnetic tripping assembly, terminal screw assembly, and thermal element adopt a modular design, enabling modular assembly of the thermal-magnetic tripping mechanism. Consequently, the thermal-magnetic tripping mechanism of the circuit breaker has the advantages of simple structure, stable and reliable performance, and convenient assembly.

Claims

1. A thermal-magnetic tripping mechanism for a circuit breaker, comprising a thermal element, a thermal-magnetic tripping assembly disposed on one end of the thermal element, and a terminal screw assembly disposed on the other end of the thermal element, characterized in that: The thermal magnetic trip assembly includes a yoke, an armature bracket arranged on the yoke, a bimetallic strip, an armature rotatably arranged on the armature bracket, and a torsion spring arranged between the armature and the armature bracket. The yoke and bimetallic strip are respectively arranged on both sides of one end of the thermal element. The wiring screw assembly includes a fixed plate arranged in the base, a wiring seat arranged on the fixed plate, and a wiring screw. The other end of the thermal element is provided with a waist-shaped hole, and one end of the wiring seat is provided with a positioning protrusion that is engaged in the waist-shaped hole, and the positioning protrusion is cooperated with the thermal element to form a limiting fit. The wiring screw passes through the waist-shaped hole and is connected to the wiring seat.

2. The thermal-magnetic tripping mechanism of a circuit breaker according to claim 1, characterized in that: One end of the armature is provided with an attraction plate matched with the magnetic yoke, and the magnetic yoke is provided with an attraction inclined surface matched with the attraction plate.

3. The thermal-magnetic tripping mechanism of a circuit breaker according to claim 1 or 2, characterized in that: The other end of the armature has a trigger arm that cooperates with the traction rod. The trigger arm has an arc-shaped protrusion that cooperates with the inclined surface of the traction rod. The arc-shaped protrusion moves with the trigger arm and abuts against the inclined surface, thereby forming a linkage cooperation between the traction rod and the trigger arm.

4. The thermal-magnetic tripping mechanism of a circuit breaker according to claim 1 or 2, characterized in that: The armature bracket is provided with clamping blocks matching with the base on both sides, and the base is provided with a clamping groove matching with the clamping blocks. The clamping blocks are clamped in the clamping grooves to form a clamping fit between the armature bracket and the base.

5. The thermal-magnetic tripping mechanism of a circuit breaker according to claim 1 or 2, characterized in that: The other end of the wiring seat is provided with a clamping convex ring that matches the fixed plate. The fixed plate is provided with a clamping hole. The clamping convex ring is clamped in the clamping hole to form a clamping fit between the wiring seat and the fixed plate.

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