Thermal tripping device for overload protection and circuit breaker

Abstract

The utility model discloses a thermal tripping device for overload protection, which is arranged in a circuit breaker body, a static contact, a moving contact and a draw bar are arranged in the circuit breaker body, the thermal tripping device comprises a bimetallic strip, and the bimetallic strip is arranged between the moving contact and a circuit breaker base. The end, away from the static contact and opposite to the traction rod, of the bimetallic strip is a free end, and the free end of the bimetallic strip is in linkage with the traction rod under the heating deformation acting force of the bimetallic strip. The utility model also discloses a circuit breaker comprising the thermal tripping device. The utility model has the advantages of convenient installation and good time consistency. According to the utility model, the assembly mode of the bimetallic strip enables no additional heating element, and the heating source of the bimetallic strip adopts the moving contact support installed on the base of the circuit breaker as the heating element, so that the space can be saved; the moving contact support serves as a heating element, the gap between the moving contact support and the incoming and outgoing line terminal of the circuit breaker is large, the heat dissipation effect is good, and heating can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit breaker technical field, in particular to a kind of thermal trip device and circuit breaker for overload protection. BACKGROUND

[0002] Circuit breaker is a kind of switch device that can be closed, load and open the current under normal loop condition and can be closed, load and open the current under abnormal loop condition within specified time. Among them, thermal trip device is the important component structure of circuit breaker, when the current overload appears in main circuit, bimetallic strip in thermal trip device generates heat and deforms, drives traction rod to rotate, traction rod triggers the lock catch of operating mechanism to trip, operating mechanism actuates and cuts off main circuit, thereby realizing the function of overload protection of circuit breaker, and ensuring the safety of circuit.

[0003] At present, in existing thermal trip device, most manufacturers vertically assemble bimetallic strip, and vertical assembly mode of bimetallic strip leads to large space occupation, and vertical assembly mode also needs to additionally add a heating element, the heating element generates heat after being electrified, and the heating element will transmit temperature to incoming and outgoing line terminals of circuit breaker, so that the temperature of incoming and outgoing line terminals will be very high. The time consistency of existing thermal trip device is also not good, and existing is through a vertical screw to adjust the trip spacing, so that some circuit breakers trip early, and some circuit breakers trip late, and the trip time is inconsistent. UTILITY MODEL CONTENTS

[0004] The utility model provides a kind of thermal trip device and circuit breaker for overload protection to solve the problems and deficiencies of prior art.

[0005] The utility model solves the above technical problems by the following technical solutions:

[0006] The utility model provides a kind of thermal trip device for overload protection, is placed in circuit breaker body, the static contact, movable contact and traction rod are arranged in the circuit breaker body, and it is characterized in that, the thermal trip device includes bimetallic strip, the bimetallic strip is installed and arranged between movable contact and circuit breaker base, and the end of the bimetallic strip away from static contact and opposite to traction rod is free end, and the free end of the bimetallic strip links traction rod under the heating deformation force of bimetallic strip.

[0007] The technical scheme can realize the overload protection function of circuit breaker.

[0008] Preferably, the bimetallic strip is connected with the movable contact or the bimetallic strip is oppositely arranged with the movable contact, the movable contact generates heat and transmits heat to the bimetallic strip under the overload of circuit breaker, and the free end of the bimetallic strip links traction rod under the heating deformation force of bimetallic strip.

[0009] Preferably, the circuit breaker body is further provided with a movable contact support, the movable contact is fixedly installed on the circuit breaker base through the movable contact support, the movable contact support extends to form a right connecting plate towards the static contact, the bimetallic strip is installed on the right connecting plate through the fixed end, and the bimetallic strip is connected with the movable contact through the right connecting plate.

[0010] In the technical solution, the bimetallic strip is installed between the movable contact and the circuit breaker base, and the movable contact support is used as the heating element of the bimetallic strip, so that no additional heating element is needed, space is effectively saved, the movable contact support is used as the heating element, the gap between the movable contact support and the incoming and outgoing line terminals of the circuit breaker is large, the heat dissipation effect is good, and the heating is reduced.

[0011] Preferably, the movable contact support is a U-shaped movable contact support, the groove of the U-shaped movable contact support is oppositely arranged with the movable contact, the bottom of the U-shaped movable contact support extends to form a right connecting plate towards the static contact, the bimetallic strip is installed on the right connecting plate through the fixed end, the bottom of the U-shaped movable contact support extends to form a left connecting plate away from the static contact, and the left connecting plate is electrically connected with the conductive connecting plate away from the static contact in the circuit breaker body.

[0012] Preferably, the bimetallic strip is arranged through the groove of the U-shaped movable contact support, and the fixed end and the free end of the bimetallic strip are located on both sides of the groove of the U-shaped movable contact support.

[0013] Preferably, the thermal trip device further comprises a linkage adjusting mechanism, the bottom end of the linkage adjusting mechanism is matched with the free end of the bimetallic strip, and the top end of the linkage adjusting mechanism is matched with the traction rod, so that the linkage adjusting mechanism links the traction rod under the heating deformation force of the bimetallic strip.

[0014] Preferably, the linkage adjusting mechanism comprises a mounting bracket and an adjustable overload pushing piece, the mounting bracket is arranged between the free end of the bimetallic strip and the traction rod, the adjustable overload pushing piece is mounted on the mounting bracket, the bottom end of the adjustable overload pushing piece is matched with the free end of the bimetallic strip, and the top end of the adjustable overload pushing piece is matched with the traction rod.

[0015] Preferably, the adjustable overload pushing piece comprises an adjustable screw and a thermal trip piece, the adjustable screw is vertically arranged through the mounting bracket, the bottom end of the adjustable screw is located directly above the free end of the bimetallic strip, the top end of the adjustable screw is fixed with the thermal trip piece, and the tripping end of the thermal trip piece is located directly below the traction block of the traction rod.

[0016] Preferably, the linkage adjusting mechanism further comprises a reset spring, the reset spring is sleeved on the adjustable screw, the bottom end of the reset spring is abutted with the bottom flange of the adjustable screw, and the top of the reset spring is abutted with the bottom of the mounting bracket.

[0017] Preferably, the mounting bracket is mounted on a fixing seat of the transformer case in the circuit breaker body.

[0018] Preferably, the mounting bracket comprises a mounting plate and a U-shaped bracket fixed on the side of the mounting plate, and the mounting plate is fixed on the bottom of the fixing seat.

[0019] Preferably, the top end of the adjustable screw passes through the U-shaped bracket, the thermal trip unit is sequentially connected by a horizontal plate, a vertical plate and a longitudinal plate, the horizontal plate is fixed on the top of the adjustable screw and located in the U-shaped bracket, the vertical plate is in contact with the inner wall of one side of the U-shaped bracket as a guide part, and the tripping end of the longitudinal plate is located directly below the traction block.

[0020] The U-shaped bracket guides the up-and-down movement of the thermal trip unit, so that the thermal trip unit can stably move up and down without deviation.

[0021] Preferably, the tripping end of the longitudinal plate is smoothly transitioned, the traction block is a traction inclined block, and the tripping end of the longitudinal plate is close to the bottom end of the traction inclined block.

[0022] In the technical solution, the smoothly transitioned tripping end of the longitudinal plate of the thermal trip unit and the inclined setting of the traction block of the traction rod form a mutual cooperation relationship, which is more conducive to rotating the traction rod.

[0023] Preferably, a movable contact support is further arranged in the circuit breaker body, the movable contact is fixedly mounted on the circuit breaker base through the movable contact support, and the bimetallic strip is arranged between the movable contact and the movable contact support.

[0024] The utility model also provides a circuit breaker, and the circuit breaker comprises the thermal tripping device.

[0025] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be combined at will, thereby obtaining each preferred example of the utility model.

[0026] The utility model discloses a positive progress effect lies in:

[0027] The thermal tripping device and the circuit breaker are convenient to install, have good time consistency, and do not have the phenomena of early tripping of some circuit breakers and late tripping of some circuit breakers.

[0028] In the utility model, the bimetallic strip is arranged between the movable contact and the circuit breaker base, the free end of the bimetallic strip is opposite to the traction rod, the bimetallic strip does not need to additionally add a heating element in this assembly mode, the heating source of the bimetallic strip adopts the movable contact support arranged on the circuit breaker base as a heating element, space can be saved, the movable contact support as a heating element has a relatively large gap between inlet and outlet terminals of the circuit breaker, has a relatively good heat dissipation effect, and can reduce heating.

[0029] The mounting fixed frame, the adjustable screw, the thermal tripping piece and the reset spring are arranged in a vertical direction, the design is relatively ingenious, the space in the circuit breaker body is relatively small, and the function expansion of the circuit breaker is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figures 1-4 The utility model discloses a structure diagram of the thermal tripping device for overload protection of the preferred embodiment.

[0031] Figure 5 The utility model discloses a structure diagram of the mounting fixed frame of the preferred embodiment.

[0032] Figure 6 The utility model discloses a structure diagram of the thermal tripping piece of the preferred embodiment.

[0033] Wherein, 10, mutual inductor shell;11, fixed base;20, pull rod;21, pull inclined block;30, movable contact;40, movable contact support;41, left connecting plate;42, right connecting plate;50, conductive connecting plate;Bimetallic strip 60;Linkage adjusting mechanism 70;71, mounting fixed frame;711, mounting plate;7111, first convex ring;712, U type frame;72, adjustable overload push piece;721, adjustable screw;722, thermal tripping piece;7221, horizontal plate;72211, second convex ring;7222, vertical plate;7223, longitudinal plate;72231, tripping end;73, reset spring;90, bolt;100, operating mechanism;110 static contact. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantage of the utility model embodiment more clear, the technical scheme in the utility model embodiment will be described clearly and completely below in combination with the drawings in the utility model embodiment, obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without creative labor belong to the scope of the utility model protection.

[0035] For the convenience of description, only the parts related to the utility model are shown in the drawings. The first, second and the like involved in the utility model are only for the convenience of describing the technical scheme of the utility model and do not have a specific limiting effect, and all refer to a general term, which does not constitute a limiting effect on the technical scheme of the utility model. It should be noted that the embodiments in the application and the features in the embodiments can be combined with each other in the case of no conflict. The terms "intermediate", "horizontal", "vertical", "longitudinal", "front", "rear", "left", "right", "inner", "outer" and the like indicating the positional relationship are based on the positional relationship shown in the drawings and do not represent that the components must be presented in the positional relationship expressed, which does not constitute a limiting effect on the technical scheme of the utility model.

[0036] As shown in Figures 1-6 The embodiment provides a thermal trip device for overload protection, which is arranged in a circuit breaker body, and the circuit breaker body is provided with a mutual inductor shell 10, a traction rod 20, a movable contact 30, a movable contact support 40, a conductive connecting plate 50 and a static contact 110. The thermal trip device comprises a bimetallic strip 60 and a linkage adjusting mechanism 70.

[0037] The movable contact support 40 is connected with the movable contact 30, and the movable contact support 40 is a U-shaped movable contact support. The movable contact 30 is fixedly installed on the circuit breaker base through the U-shaped movable contact support 40. The groove of the U-shaped movable contact support 40 is arranged opposite to the movable contact 30. The bottom of the U-shaped movable contact support 40 extends to the direction close to the static contact to form a right connecting plate 42. The bottom of the U-shaped movable contact support 40 extends to the direction away from the static contact 110 to form a left connecting plate 41.

[0038] The bimetallic strip 60 is arranged between the movable contact 30 and the U-shaped movable contact support 40. One end of the bimetallic strip 60, which is away from the static contact 110 and opposite to the traction rod 20, is a free end. The free end of the bimetallic strip 60 links the traction rod 20 under the bimetallic strip heating deformation force.

[0039] Further, the bimetallic strip 60 is arranged opposite to the movable contact 30. The movable contact 30 generates heat under the overload of the circuit breaker and transmits the heat to the bimetallic strip 60. The free end of the bimetallic strip 60 links the traction rod 20 under the bimetallic strip heating deformation force. In this way of arranging the bimetallic strip 60 opposite to the movable contact 30, the bimetallic strip 60 obtains heat through the non-contact heat transmission mode, and the bimetallic strip 60 realizes passive heating deformation.

[0040] The bimetallic strip 60 is connected with the movable contact 30, the movable contact 30 generates heat under the overload of the circuit breaker and transmits the heat to the bimetallic strip 60, and the free end of the bimetallic strip 60 drags the lever 20 under the deformation force of the bimetallic strip. In this way, the bimetallic strip 60 is connected with the movable contact 30, the bimetallic strip 60 obtains heat through direct or indirect heat transmission, and the bimetallic strip 60 is passively heated and deformed.

[0041] In this embodiment, the bimetallic strip 60 is connected with the movable contact 30 through the right connecting plate 42, and the bimetallic strip 60 is indirectly connected with the movable contact 30 through the right connecting plate 42.

[0042] In this embodiment, the bimetallic strip 60 is connected with the movable contact 30 through the right connecting plate 42, and the bimetallic strip 60 is indirectly connected with the movable contact 30 through the right connecting plate 42. Figure 1 In this embodiment, the bimetallic strip 60 is connected with the movable contact 30 through the right connecting plate 42, and the bimetallic strip 60 is indirectly connected with the movable contact 30 through the right connecting plate 42.

[0043] The bimetallic strip 60 is connected with the movable contact 30 through the right connecting plate 42, and the bimetallic strip 60 is indirectly connected with the movable contact 30 through the right connecting plate 42.

[0044] In this embodiment, when the main circuit of the circuit breaker is powered, the movable contact 30 is powered, the movable contact bracket 40 acts as a heating element, and transmits heat to the bimetallic strip 60. The bimetallic strip 60 is deformed and bent after being heated, and the bending degree is in a positive proportional relationship with the size of the main circuit current.

[0045] The left connecting plate 41 is electrically connected with the conductive connecting plate 50 away from the static contact 110 in the circuit breaker body.

[0046] The bimetallic strip 60 is connected with the movable contact 30 through the right connecting plate 42, and the bimetallic strip 60 is indirectly connected with the movable contact 30 through the right connecting plate 42.

[0047] The linkage adjusting mechanism 70 comprises a mounting bracket 71, an adjustable overload pushing piece 72 and a reset spring 73. The mounting bracket 71 is arranged between the free end of the bimetallic strip 60 and the traction rod 20, and the adjustable overload pushing piece 72 is mounted on the mounting bracket 71. The bottom end of the adjustable overload pushing piece 72 is matched with the free end of the bimetallic strip 60, and the top end of the adjustable overload pushing piece 72 is matched with the traction rod 20. The free end of the bimetallic strip 60 triggers the bottom end of the adjustable overload pushing piece 72 under the action of heat deformation, and the top end of the adjustable overload pushing piece 72 triggers the traction rod 20 in linkage to make the traction rod 20 be triggered under the action of the deformation of the bimetallic strip 60. The reset spring 73 is sleeved on the adjustable overload pushing piece 72, and is used for resetting the adjustable overload pushing piece 72.

[0048] The mounting bracket 71 comprises a mounting plate 711 and a U-shaped bracket 712. The mounting plate 711 is fixed on the bottom of the fixed seat 11 of the transformer housing 10 by the bolt 90, and the U-shaped bracket 712 is fixed on the side of the mounting plate 711. In the embodiment, the mounting plate 711 and the U-shaped bracket 712 can be integrally formed.

[0049] The mounting plate 711 is fixed on the bottom of the fixed seat 11 by the bolt 90 in the following manner: two first convex rings 7111 are fixed on the top of the mounting plate 711, two fixed holes corresponding to the first convex rings 7111 are formed on the fixed seat 11, each first convex ring 7111 is inserted into the corresponding fixed hole, and the bolt 90 is used for bolt fixing.

[0050] The adjustable overload pushing piece 72 comprises an adjustable screw 721 and a thermal trip piece 722. The top end of the adjustable screw 721 is vertically arranged in the U-shaped bracket 712, the bottom end of the adjustable screw 721 is located directly above the free end of the bimetallic strip 60, the top end of the adjustable screw 721 is fixed with the thermal trip piece 722, the thermal trip piece 722 is arranged in the U-shaped bracket 712, and the tripping end of the thermal trip piece 722 is located directly below the traction block 21 of the traction rod 20.

[0051] The thermal trip piece 722 is sequentially connected by a horizontal plate 7221, a vertical plate 7222 and a longitudinal plate 7223, and the horizontal plate 7221, the vertical plate 7222 and the longitudinal plate 7223 can be integrally formed. The horizontal plate 7221 is fixed on the top of the adjustable screw 721 and located in the U-shaped bracket 712. The vertical plate 7222 is in contact with the inner wall (as a guide part) of one side of the U-shaped bracket 712. The tripping end 72231 of the longitudinal plate 7223 is located directly below the traction block 21.

[0052] The specific implementation that the horizontal plate 7221 of the thermal trip unit 722 is fixed to the top of the adjustable screw 721 is that: the horizontal plate 7221 is provided with a hole, the top of the horizontal plate 7221 is fixed with a second convex ring 72211 around the hole, and the horizontal plate 7221 is sleeved on the top of the adjustable screw 721 through the hole and is fixed to the top of the adjustable screw 721 through the second convex ring 72211.

[0053] In the embodiment, the vertical plate 7222 of the thermal trip unit 722 is in contact with the left inner wall of the U-shaped frame 712, and the left inner wall of the U-shaped frame 712 can serve as a guide portion of the vertical plate 7222 and play a guiding role when the thermal trip unit 722 moves up and down.

[0054] Further, the trip end 72231 of the longitudinal plate 7223 is smoothly transitioned, the traction block 21 is a traction inclined block, and the trip end of the longitudinal plate 7223 is close to the bottom end of the traction inclined block 21, so that the trip end of the thermal trip unit 722 can better push the traction inclined block 21 of the traction rod 20 under the deformation force of the bimetallic strip 60, and the rotation of the traction rod 20 is facilitated.

[0055] The reset spring 73 is sleeved on the adjustable screw 721, the bottom end of the reset spring 73 is abutted against the bottom flange of the adjustable screw 721, and the top end is abutted against the bottom of the U-shaped frame 712.

[0056] In the embodiment, the adjustable screw 721 is provided, which is beneficial to adjust the distance between the free end of the bimetallic strip 60 and the bottom of the adjustable screw 721, so as to adjust the time when the adjustable screw 72 is triggered by the bimetallic strip 60. Specifically, if the adjustable screw 721 is loosened downward, the distance between the free end of the bimetallic strip 60 and the bottom of the adjustable screw 721 will be smaller, so that the bimetallic strip 60 can push the adjustable screw 721 to trigger the traction rod 20 through a small deformation, the triggering time of the traction rod is relatively short, and the deformation time is relatively short; if the adjustable screw 721 is screwed upward, the reset spring 73 is compressed, the distance between the free end of the bimetallic strip 60 and the bottom of the adjustable screw 721 will be larger, so that the bimetallic strip 60 needs a larger deformation to trigger the bottom of the adjustable screw 721, the time to trigger the traction rod 20 is larger, that is, the deformation time is larger.

[0057] The use process of the thermal trip device of the embodiment is as follows: the circuit breaker is closed by operating the mechanism 100, the circuit breaker main circuit is powered, the static contact 110 and the moving contact 30 are electrically connected, when the circuit breaker is overloaded, the moving contact 30 is heated, causing the bimetallic strip 60 to be heated and deformed, after the bimetallic strip 60 is heated and deformed, the free end of the bimetallic strip 60 drives the adjustable screw 721 and the thermal trip piece 722 to move upward, the tripping end of the thermal trip piece 70 pushes the traction inclined block 21 of the traction rod 20, the traction rod 20 is pushed to rotate, the operating mechanism 100 of the circuit breaker is tripped, the circuit breaker is opened, and the circuit breaker is protected from being closed.

[0058] The embodiment also provides a circuit breaker, which comprises the three thermal trip devices described above, corresponding to three phases of A, B and C respectively, and the thermal trip pieces 722 of the three thermal trip devices correspond to the three traction inclined blocks 21 on the traction rod 20 one by one. When the tripping end of any one of the thermal trip pieces 722 pushes the traction inclined block 21 of the traction rod 20, the circuit breaker can be opened, and the circuit breaker is protected.

[0059] Although the specific embodiments of the utility model are described above, those skilled in the art should understand that these are only illustrative, the protection scope of the utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the utility model, but these changes and modifications all fall within the protection scope of the utility model.

Claims

1. A thermal trip device for overload protection disposed in a circuit breaker body, said circuit breaker body having a stationary contact, a movable contact and a trip bar disposed therein, characterized by, The thermal trip device comprises a bimetallic strip, which is arranged between the moving contact and the circuit breaker base, and the end of the bimetallic strip away from the static contact and opposite to the traction rod is a free end, and the free end of the bimetallic strip drives the traction rod under the deformation force of the bimetallic strip.

2. A thermal trip device for overload protection according to claim 1, wherein The bimetallic strip is connected with the moving contact or arranged opposite to the moving contact, the moving contact generates heat under the overload of the circuit breaker and transmits the heat to the bimetallic strip, and the free end of the bimetallic strip drives the traction rod under the deformation force of the bimetallic strip.

3. A thermal trip device for overload protection according to claim 2, wherein The circuit breaker body is further provided with a moving contact support, the moving contact is fixedly installed on the circuit breaker base through the moving contact support, the moving contact support extends towards the static contact to form a right connecting plate, the bimetallic strip is installed on the right connecting plate through the fixed end, and the bimetallic strip is connected with the moving contact through the right connecting plate.

4. A thermal trip device for overload protection according to claim 3, wherein The moving contact support is a U-shaped moving contact support, the groove of the U-shaped moving contact support is arranged opposite to the moving contact, the bottom of the U-shaped moving contact support extends towards the static contact to form a right connecting plate, the bimetallic strip is installed on the right connecting plate through the fixed end, the bottom of the U-shaped moving contact support extends away from the static contact to form a left connecting plate, and the left connecting plate is electrically connected with the conductive connecting plate away from the static contact in the circuit breaker body.

5. A thermal trip device for overload protection according to claim 4, wherein The bimetallic strip passes through the groove of the U-shaped moving contact support, and the fixed end and the free end of the bimetallic strip are located on both sides of the groove of the U-shaped moving contact support.

6. The thermal overload protection device of claim 1, wherein the thermal overload protection device is configured to be mounted on a printed circuit board. The thermal trip device further comprises a linkage adjusting mechanism, the bottom end of the linkage adjusting mechanism is matched with the free end of the bimetallic strip, and the top end of the linkage adjusting mechanism is matched with the traction rod, so that the linkage adjusting mechanism drives the traction rod under the deformation force of the bimetallic strip.

7. A thermal trip device for overload protection according to claim 6, wherein The linkage adjusting mechanism comprises a mounting bracket and an adjustable overload pushing piece, the mounting bracket is arranged between the free end of the bimetallic strip and the traction rod, the adjustable overload pushing piece is installed on the mounting bracket, the bottom end of the adjustable overload pushing piece is matched with the free end of the bimetallic strip, and the top end of the adjustable overload pushing piece is matched with the traction rod.

8. A thermal trip device for overload protection according to claim 7, wherein The adjustable overload pushing piece comprises an adjustable screw and a thermal trip piece, the adjustable screw vertically passes through the mounting bracket, the bottom end of the adjustable screw is located directly above the free end of the bimetallic strip, the top end of the adjustable screw is fixed with the thermal trip piece, and the tripping end of the thermal trip piece is located directly below the traction block of the traction rod.

9. A thermal trip device for overload protection according to claim 8 wherein, The linkage adjusting mechanism further comprises a reset spring, the reset spring is sleeved on the adjustable screw, the bottom end of the reset spring is abutted with the bottom flange of the adjustable screw, and the top end of the reset spring is abutted with the bottom of the mounting bracket.

10. The thermal overload protection device of claim 8, wherein the thermal overload protection device is configured to be mounted on a printed circuit board. The mounting bracket is installed on the fixing seat of the transformer housing in the circuit breaker body.

11. The thermal overload protection device of claim 10, wherein the thermal overload protection device is configured to be mounted on a circuit breaker. The mounting bracket comprises a mounting plate and a U-shaped bracket fixed on the side of the mounting plate, and the mounting plate is fixed on the bottom of the fixing seat.

12. The thermal overload protection device of claim 11, wherein the thermal overload protection device is configured to be mounted on a printed circuit board. The top end of the adjustable screw passes through the U-shaped frame, the thermal trip is sequentially connected by a horizontal plate, a vertical plate and a longitudinal plate, the horizontal plate is fixed on the top of the adjustable screw and located in the U-shaped frame, the vertical plate is in contact with the inner wall of one side of the U-shaped frame as a guide part, and the trip end of the longitudinal plate is located directly below the traction block.

13. The thermal overload protection device of claim 12, wherein the thermal overload protection device is configured to be mounted on a printed circuit board. The trip end of the longitudinal plate is smoothly transitioned, the traction block is a traction inclined block, and the trip end of the longitudinal plate is close to the bottom end of the traction inclined block.

14. The thermal overload protection device of claim 1, wherein the thermal overload protection device is configured to be mounted on a printed circuit board. The circuit breaker body is also provided with a movable contact support, the movable contact is fixedly installed on the circuit breaker base through the movable contact support, and the bimetallic strip is arranged between the movable contact and the movable contact support.

15. A circuit breaker characterized by, It comprises the thermal trip device of any one of claims 1-14.

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