High-density intelligent circuit breaker

Abstract

The utility model relates to a high-density intelligent circuit breaker, and relates to the technical field of circuit breakers, the high-density intelligent circuit breaker comprises a shell, a wiring terminal and a shell cover, the wiring terminal and the shell cover are located in the shell, and a contact assembly, an operation assembly, an arc extinguishing assembly and an overload protection assembly are arranged in the shell. The contact assembly comprises a static contact fixed in the shell, a linkage piece rotationally arranged in the shell and a moving contact arranged on the linkage piece; a remote adjusting assembly is arranged in the shell and comprises an adjusting plate arranged in the shell in a sliding mode and a micro motor fixed in the shell, the micro motor is used for driving the adjusting plate to slide, and a coaxial adjusting gear is arranged on a driving shaft of the micro motor; an adjusting rack meshed with the adjusting gear is arranged on the adjusting plate; according to the circuit breaker, the remote adjusting assembly is arranged in the shell, self closing can be remotely controlled, the overall size of the circuit breaker is not increased, and the requirement for high energy density is met.

Description

Technical Field

[0001] The present application relates to the technical field of circuit breakers, and in particular to a high-density intelligent circuit breaker. Background Art

[0002] With the development of science and technology and the popularization of electronic equipment, the demand for electricity is growing, and the scale of the power system is also expanding. At the same time, people have put forward higher requirements for the reliability, safety and efficiency of the power system; high-density intelligent circuit breakers, as an advanced power control device, play an important role in ensuring the stable operation of the power system.

[0003] In the related technology, there is a utility model with publication number CN210722939U, a flat and long high-breaking hydraulic electromagnetic circuit breaker for front-out and rear-in lines, including a base shell, and a pull ring, a handle, a connecting rod shaft, a pull rod, a snap-on locking mechanism, a tripping mechanism, a moving contact, an arc extinguishing chamber, an incoming line terminal, a copper busbar, a static contact, an armature and an outgoing line mechanism all installed on the base shell.

[0004] Although the above-mentioned circuit breaker can be equipped with a remote operation component on the outside, the installed structure usually adopts an external module, a guide rail, etc., which will cause the overall volume of the installed circuit breaker to be larger and unable to meet the requirements of high energy density use; when the circuit breaker is used in a high energy density environment, it needs to withstand greater mechanical stress. If the mechanical strength of the circuit breaker is insufficient (unable to meet the requirements of high energy density use), it may cause damage to its internal structure, poor contact and other problems, thereby affecting its normal operation. Utility Model Content

[0005] The purpose of the present application is to provide a high-density intelligent circuit breaker to solve the problem in the above-mentioned related technologies that the modified circuit breaker is large in size and cannot meet the requirements of high energy density use.

[0006] A high-density intelligent circuit breaker provided in this application adopts the following technical solution:

[0007] A high-density intelligent circuit breaker comprises a shell, a wiring terminal and a shell cover located in the shell, wherein a contact assembly, an operating assembly for manually controlling the contact assembly, an arc extinguishing assembly and an overload protection assembly are also arranged inside the shell, wherein the contact assembly comprises a stationary contact fixed in the shell, a linkage member rotatably arranged in the shell and a moving contact arranged on the linkage member; a remote adjustment assembly is arranged in the shell, wherein the remote adjustment assembly comprises an adjustment plate slidably arranged in the shell and a micro motor fixed in the shell, wherein the micro motor is used to drive the adjustment plate to slide, wherein a coaxial adjustment gear is arranged on the driving shaft of the micro motor, and an adjustment rack meshing with the adjustment gear is arranged on the adjustment plate; when the adjustment plate slides, the moving contact can be driven to rotate in a direction close to the stationary contact.

[0008] By adopting the above technical solution, due to the setting of the remote adjustment component, the micro motor will drive the adjustment plate to slide when it is actuated, thereby causing the moving contact on the linkage to rotate in a direction close to the static contact until the moving contact abuts against the static contact, thereby controlling the circuit breaker to perform remote closing. Compared with the remote control structure of the external module and the guide rail in the background technology, the combined structure of the micro motor, the transmission gear, the transmission rack and the adjustment plate occupies a smaller space and are all arranged inside the shell, without increasing the overall volume of the circuit breaker, which meets the requirements of high energy density.

[0009] Optionally, a first rotating rod and a second rotating rod are rotatably arranged inside the shell, and the linkage comprises a rotating plate hinged to the first rotating rod, a trip plate, and a moving touch plate hinged to the second rotating rod; the two sides of the trip plate are respectively rotatably connected to the rotating plate and the moving touch plate, a third rotating rod is arranged at the hinge of the rotating plate and the trip plate, and a limiting cavity for the third rotating rod to be inserted and slide is opened on the adjustment plate; the moving contact is arranged on the side of the moving touch plate facing the static contact.

[0010] By adopting the above technical solution, the third rotating rod is placed inside the limiting cavity, and the side wall of the limiting cavity abuts against the outer periphery of the third rotating rod. When the adjusting plate slides, it can push the third rotating rod to rotate around the axis of the first rotating rod, thereby causing the moving contact on the moving contact plate to rotate in a direction close to the static contact, thereby realizing remote closing control of the circuit breaker.

[0011] Optionally, the operating component includes a connecting rod and a control button hinged to the inner wall of the shell, the connecting rod is provided with a first bending rod and a second bending rod at both ends respectively, the control button is provided with a first positioning hole for the first bending rod to be inserted and rotated, and the rotating plate is provided with a second positioning hole for the second bending rod to be inserted and rotated.

[0012] By adopting the above technical solution, due to the coordinated setting of the connecting rod and the control button, the user can press the control button to drive the connecting rod and the rotating plate to rotate, and finally make the moving contact on the moving contact plate reciprocate in the direction close to the static contact, thereby realizing manual control of the opening and closing operations of the circuit breaker.

[0013] Optionally, an inner wall on one side of the limiting cavity is a guiding arc surface, and when the operating component manually controls the movement of the moving contact, the outer periphery of the third rotating rod slides along the guiding arc surface.

[0014] By adopting the above technical solution, when the user manually controls the opening and closing of the circuit breaker through the operating component, the outer periphery of the third rotating rod abuts against the guiding arc surface and slides along the guiding arc surface during this process through the setting of the guiding arc surface on the side wall of the limiting cavity, so as to limit the third rotating rod under manual operation and reduce the possibility of the third rotating rod being offset or misaligned during the rotation process around the first rotating rod.

[0015] Optionally, the overload protection assembly includes an iron core, a coil wound around the outer circumference of the iron core, and an armature located at the end of the iron core, and the end of the armature away from the coil is connected to a lever; a fourth rotating rod rotatably connected to the inner wall of the shell is provided at the connection between the armature and the lever, a first torsion spring for rotating the armature away from the iron core is sleeved on the outer circumference of the fourth rotating rod, and a positioning rod located on one side of the lever is provided on the trip plate.

[0016] By adopting the above technical solution, due to the setting of the overload protection component, when a short circuit or fault occurs, current is passed through the coil to make the iron core have magnetic force and attract the armature, so that the armature and the shift rod rotate around the fourth rotating rod. At this time, the shift rod squeezes the positioning rod on the trip plate, and at the same time disconnects the moving contact and the static contact in the abutting state, thereby realizing the opening of the circuit breaker and disconnecting the circuit connected to the circuit breaker.

[0017] Optionally, a protrusion is provided on the side of the lever facing the positioning rod, and the side of the protrusion facing the positioning rod is an arc surface.

[0018] By adopting the above technical solution, when the moving contact abuts against the static contact, the distance between the lever and the positioning rod is reduced due to the setting of the protrusion; when a short circuit or other fault occurs in the line connected to the circuit breaker, it is convenient for the lever to rotate and squeeze the positioning rod to disconnect the moving contact and the static contact, thereby improving the use performance and safety performance of the circuit breaker.

[0019] Optionally, the positioning rod includes a positioning plate rotatably connected to the tripping plate and an abutment rod arranged on the positioning plate, and the tripping plate is provided with a second torsion spring for driving the positioning plate to rotate toward a direction close to the shifting rod.

[0020] By adopting the above technical solution, when the moving contact abuts against the static contact, due to the installation arrangement of the second torsion spring, the outer periphery of the abutment rod abuts against one side of the shift rod. When a fault occurs in the line connected to the circuit breaker, the shift rod can effectively squeeze the outer periphery of the abutment rod, thereby disconnecting the moving contact and the static contact, thereby improving the performance of the circuit breaker.

[0021] Optionally, a fixed frame is provided inside the shell for limiting the rotation of the first rotating rod, the second rotating rod and the fourth rotating rod; a bending plate is provided on the fixed frame, and a plurality of limiting teeth are provided on the side of the lever, and the hooks at both ends of the first torsion spring are fixedly connected to the limiting teeth and the bending plate respectively.

[0022] By adopting the above technical solution, due to the coordinated arrangement of the bending plate and the limiting teeth, the first torsion spring can be easily installed and fixed, and the hook can be fixed on different limiting teeth, thereby adjusting the torque of the first torsion spring.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. Due to the setting of the remote adjustment component, when the micro motor is actuated, it will drive the adjustment plate to slide, thereby causing the moving contact on the linkage to rotate in the direction close to the static contact until the moving contact abuts against the static contact, thereby controlling the circuit breaker to perform remote closing. Compared with the remote control structure of the external module and the guide rail in the background technology, the combined structure of the micro motor, the transmission gear, the transmission rack and the adjustment plate occupies a smaller space and are all arranged inside the shell, without increasing the overall volume of the circuit breaker, meeting the requirements of high energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0027] Figure 2 This is a structural diagram of the installation distribution of the operating assembly and the contact assembly in an embodiment of the present application;

[0028] Figure 3 It is a partial structural schematic diagram of an embodiment of the present application when the circuit breaker is in an open state;

[0029] Figure 4 It is a schematic diagram of a local structure of an embodiment of the present application when the circuit breaker is in a closed state;

[0030] Figure 5 It is a partial structural diagram of the installation and coordination of the operating components in the embodiment of the present application;

[0031] Figure 6 It is a partial structural schematic diagram of the installation and coordination of the adjustment plate in the embodiment of the present application;

[0032] Figure 7 is a schematic diagram of the structure of the first compression spring and the armature installation cooperation in the embodiment of the present application;

[0033] Figure 8 It is a partial structural diagram of the installation and coordination of the overload protection component in the embodiment of the present application;

[0034] Fig. 9 yes Figure 8 A magnified schematic diagram of part A;

[0035] Fig.10 This is a schematic diagram of the structure of the first compression spring installation and matching in the embodiment of the present application;

[0036] Fig.11 It is a structural schematic diagram of the installation and coordination of the arc extinguishing assembly in an embodiment of the present application.

[0037] In the figure, 1, housing; 11, terminal; 12, first rotating rod; 13, second rotating rod; 14, third rotating rod; 15, fourth rotating rod; 16, fixed frame; 161, bending plate; 2, housing cover; 3, contact assembly; 31, static contact; 32, linkage; 321, rotating plate; 322, tripping plate; 323, moving contact plate; 33, moving contact; 34, positioning rod; 341, positioning plate; 342, abutting rod; 343, second torsion spring; 4, operating assembly; 41, control button; 42, connecting rod Connecting rod; 421, first bending rod; 422, second bending rod; 5, arc extinguishing assembly; 51, arc extinguishing grid; 6, overload protection assembly; 61, iron core; 62, coil; 63, armature; 64, lever; 641, protrusion; 642, limit tooth; 65, first torsion spring; 7, remote adjustment assembly; 71, adjustment plate; 711, adjustment rack; 712, limit cavity; 7121, guide arc surface; 713, first limit slide groove; 714, second limit slide groove; 72, micro motor; 73, adjustment gear. DETAILED DESCRIPTION

[0038] The present application is further described in detail below in conjunction with all the accompanying drawings.

[0039] Example:

[0040] Reference Figure 1 and Figure 2A high-density intelligent circuit breaker includes a housing 1, two wiring terminals 11 located in the housing 1, and a housing cover 2 fixed to the housing 1. The housing 1 is also provided with a contact assembly 3, an operating assembly 4 for manually controlling the contact assembly 3, and an overload protection assembly 6. The overload protection assembly 6 is used to protect the circuit breaker when a short circuit or a fault occurs;

[0041] The contact assembly 3 includes a stationary contact 31 fixed in the housing 1, a linkage member 32 rotatably arranged in the housing 1, and a moving contact 33 arranged on the linkage member 32; the user can manually control the disconnection and abutment of the stationary contact 31 and the moving contact 33 through the operating assembly 4, thereby controlling the opening and closing of the circuit breaker.

[0042] Reference Figure 3 and Figure 4 A first rotating rod 12 and a second rotating rod 13 are rotatably arranged inside the shell 1, wherein the linkage member 32 includes a rotating plate 321 hinged to the first rotating rod 12, a tripping plate 322, and a moving contact plate 323 hinged to the second rotating rod 13; both sides of the tripping plate 322 are rotatably connected to the rotating plate 321 and the moving contact plate 323, respectively, and a third rotating rod 14 is arranged at the hinge of the rotating plate 321 and the tripping plate 322, and the moving contact 33 is fixedly arranged on the side of the moving contact plate 323 facing the static contact 31.

[0043] Reference Figure 5 The operating assembly 4 includes a connecting rod 42 and a control button 41 hinged to the inner wall of the housing 1, and the two ends of the connecting rod 42 are respectively provided with a first bending rod 421 and a second bending rod 422, the connecting rod 42, the first bending rod 421 and the second bending rod 422 are integrally bent, and the control button 41 is provided with a first positioning hole for the first bending rod 421 to be inserted and rotated, and the rotating plate 321 is provided with a second positioning hole for the second bending rod 422 to be inserted and rotated. In this arrangement, by manually pressing the control button 41, the connecting rod 42 and the rotating plate 321 are driven to rotate, and finally the moving touch plate 323 (see Figure 4 ) on the moving contact 33 (see Figure 4 ) towards the stationary contact 31 (see Figure 4 ) direction.

[0044] Reference Figure 3 and Figure 4 A remote adjustment component 7 is provided in the shell 1, wherein the remote adjustment component 7 includes an adjustment plate 71 slidably arranged inside the shell 1 and a micro motor 72 fixed in the shell 1, the micro motor 72 is used to drive the adjustment plate 71 to slide, a coaxial adjustment gear 73 is provided on the driving shaft of the micro motor 72, and an adjustment rack 711 meshing with the adjustment gear 73 is provided on the adjustment plate 71; due to the meshing arrangement of the adjustment gear 73 and the adjustment rack 711, when the micro motor 72 is actuated, the adjustment plate 71 will be driven to slide.

[0045] Reference Figure 4 and Figure 6 A limiting cavity 712 is provided on the adjustment plate 71 for the third rotating rod 14 to be inserted and slide. The side wall of the limiting cavity 712 abuts against the outer periphery of the third rotating rod 14, and when the adjustment plate 71 slides, it can drive the third rotating rod 14 to rotate around the axis of the first rotating rod 12, thereby causing the moving contact 33 on the moving contact plate 323 to rotate toward the direction close to the static contact 31.

[0046] Reference Figure 5 and Figure 6 The inner wall of one side of the limiting cavity 712 is a guiding arc surface 7121. When the user manually controls the circuit breaker to open or close through the operating component 4 (the adjusting plate 71 does not slide), the outer periphery of the third rotating rod 14 abuts against the guiding arc surface 7121 and slides along the guiding arc surface 7121, thereby limiting the third rotating rod 14 under manual operation.

[0047] Reference Figure 7 and Figure 8 The overload protection assembly 6 includes an iron core 61, a coil 62 wound around the outer circumference of the iron core 61, and an armature 63 located at the end of the iron core 61. The end of the armature 63 away from the coil 62 is connected to a lever 64, and the armature 63 and the lever 64 are bent and formed as one piece; a fourth rotating rod 15 rotatably connected to the inner wall of the shell 1 is provided at the connection between the armature 63 and the lever 64, and the armature 63 and the lever 64 rotate around the axis of the fourth rotating rod 15, and a first torsion spring 65 for rotating the armature 63 away from the iron core 61 is sleeved on the outer circumference of the fourth rotating rod 15, and a positioning rod 34 located on one side of the lever 64 is provided on the release plate 322.

[0048] When a short circuit or fault occurs, the overload protection assembly 6 is activated, and the armature 63 and the lever 64 rotate around the fourth rotating rod 15. At this time, the lever 64 squeezes the positioning rod 34 on the trip plate 322, and at the same time disconnects the moving contact 33 and the static contact 31 in the abutting state, thereby realizing the opening of the circuit breaker and disconnecting the circuit connected to the circuit breaker.

[0049] Reference Figure 8 and Fig. 9 The positioning rod 34 includes a positioning plate 341 rotatably connected to the trip plate 322 and an abutment rod 342 arranged on the positioning plate 341, and the trip plate 322 is provided with a second torsion spring 343 for driving the positioning plate 341 to rotate toward the direction close to the lever 64; when the moving contact 33 abuts against the static contact 31, the outer periphery of the abutment rod 342 abuts against one side of the lever 64, and when a fault occurs, the lever 64 can effectively squeeze the outer periphery of the abutment rod 342, thereby disconnecting the moving contact 33 and the static contact 31, thereby improving the performance of the circuit breaker.

[0050] Reference Figure 8 and Fig. 9 A protrusion 641 is provided on the side of the lever 64 facing the positioning rod 34, and the side of the protrusion 641 facing the positioning rod 34 is an arc surface; when the moving contact 33 abuts against the static contact 31, this arrangement reduces the distance between the lever 64 and the positioning rod 34, making it easier for the lever 64 to squeeze the positioning rod 34 when it rotates, so that the moving contact 33 and the static contact 31 are disconnected.

[0051] Reference Figure 8 and Fig.10 A fixed frame 16 for limiting the rotation of the first rotating rod 12, the second rotating rod 13 and the fourth rotating rod 15 is fixedly arranged inside the shell 1, and a bending plate 161 is fixedly arranged on the fixed frame 16. A plurality of limiting teeth 642 are evenly distributed on the side of the lever 64. The hooks at both ends of the first torsion spring 65 are fixedly connected to the limiting teeth 642 and the bending plate 161 respectively, and the user can fix the hooks on different limiting teeth 642 to adjust the torque of the first torsion spring 65.

[0052] Reference Figure 6 The adjustment plate 71 is provided with a first limiting groove 713 for inserting the first rotating rod 12 and a second limiting groove 714 for inserting the fourth rotating rod 15, and the length directions of the first limiting groove 713 and the second limiting groove 714 are parallel, and the second limiting groove 714 is connected to the limiting cavity 712, so as to realize the sliding connection between the adjustment plate 71 and the shell 1, and the adjustment plate 71 can slide along the length direction of the first limiting groove 713.

[0053] Reference Fig.11 An arc extinguishing assembly 5 is arranged in the housing 1, and the arc extinguishing assembly 5 includes a plurality of arc extinguishing grids 51 fixed in the housing 1, and the plurality of arc extinguishing grids 51 are located outside the static contact 31; when the moving contact 33 and the static contact 31 are disconnected, an arc may be generated, and the arc can be divided into many short arcs by the arc extinguishing grids 51, so that the arc is quickly cooled and extinguished, thereby avoiding the arc burning the contacts and improving the arc extinguishing ability of the circuit breaker.

[0054] The implementation principle of the embodiment of the present application is:

[0055] During the application of the intelligent circuit breaker, the opening and closing of the circuit breaker can be manually controlled by the operating component 4. When it is inconvenient for the staff to manually operate the circuit breaker, the opening of the circuit breaker can be remotely controlled by the remote adjustment component 7; when a fault or short circuit occurs, the overload protection component 6 is started and the circuit breaker is adjusted to the open state.

[0056] Unless otherwise defined, the terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. The "first", "second", "third" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "One" or "one" and other similar words do not indicate a quantitative limit, but indicate that there is at least one. "Including" or "comprising" and other similar words mean that the elements or objects appearing in front of "including" or "comprising" cover the elements or objects listed after "including" or "comprising" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0057] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-density intelligent circuit breaker, comprising a housing (1), a wiring terminal (11) located in the housing (1) and a housing cover (2); a contact assembly (3), an operating assembly (4) for manually controlling the contact assembly (3), an arc extinguishing assembly (5) and an overload protection assembly (6) are further arranged inside the housing (1); the contact assembly (3) comprises a stationary contact (31) fixed in the housing (1), a linkage member (32) rotatably arranged in the housing (1) and a moving contact (33) arranged on the linkage member (32); It is characterized in that A remote adjustment component (7) is provided in the housing (1), and the remote adjustment component (7) comprises an adjustment plate (71) slidably arranged inside the housing (1) and a micro motor (72) fixed in the housing (1); the micro motor (72) is used to drive the adjustment plate (71) to slide; a coaxial adjustment gear (73) is provided on the driving shaft of the micro motor (72); and an adjustment rack (711) meshing with the adjustment gear (73) is provided on the adjustment plate (71); when the adjustment plate (71) slides, it can drive the moving contact (33) to rotate in a direction close to the stationary contact (31).

2. A high-density intelligent circuit breaker according to claim 1, characterized in that: The housing (1) is internally rotatably provided with a first rotating rod (12) and a second rotating rod (13); the linkage member (32) comprises a rotating plate (321) hinged to the first rotating rod (12), a tripping plate (322), and a moving contact plate (323) hinged to the second rotating rod (13); The two sides of the release plate (322) are rotatably connected to the rotating plate (321) and the moving contact plate (323) respectively; a third rotating rod (14) is provided at the hinge of the rotating plate (321) and the release plate (322); a limiting cavity (712) for the third rotating rod (14) to be inserted and slide is provided on the adjustment plate (71); and the moving contact (33) is arranged on the side of the moving contact plate (323) facing the stationary contact (31).

3. A high-density intelligent circuit breaker according to claim 2, characterized in that: The operating assembly (4) comprises a connecting rod (42) and a control button (41) hinged to the inner wall of the housing (1); the two ends of the connecting rod (42) are respectively provided with a first bending rod (421) and a second bending rod (422); the control button (41) is provided with a first positioning hole for the first bending rod (421) to be inserted and rotated; the rotating plate (321) is provided with a second positioning hole for the second bending rod (422) to be inserted and rotated.

4. A high-density intelligent circuit breaker according to claim 3, characterized in that: One side inner wall of the limiting cavity (712) is a guiding arc surface (7121), and when the operating component (4) manually controls the moving contact (33) to move, the outer periphery of the third rotating rod (14) slides along the guiding arc surface (7121).

5. A high-density intelligent circuit breaker according to claim 2, characterized in that: The overload protection assembly (6) comprises an iron core (61), a coil (62) wound around the outer periphery of the iron core (61), and an armature (63) located at the end of the iron core (61); the end of the armature (63) away from the coil (62) is connected to a lever (64); A fourth rotating rod (15) rotatably connected to the inner wall of the housing (1) is provided at the connection between the armature (63) and the shifting rod (64); a first torsion spring (65) for rotating the armature (63) away from the iron core (61) is sleeved on the outer periphery of the fourth rotating rod (15); and a positioning rod (34) located on one side of the shifting rod (64) is provided on the release plate (322).

6. A high-density intelligent circuit breaker according to claim 5, characterized in that: The side of the lever (64) facing the positioning rod (34) is provided with a protrusion (641), and the side of the protrusion (641) facing the positioning rod (34) is an arc surface.

7. A high-density intelligent circuit breaker according to claim 5, characterized in that: The positioning rod (34) comprises a positioning plate (341) rotatably connected to the release plate (322) and an abutment rod (342) arranged on the positioning plate (341); the release plate (322) is provided with a second torsion spring (343) for driving the positioning plate (341) to rotate in a direction close to the shifting rod (64).

8. The high-density intelligent circuit breaker according to claim 5, characterized in that: A fixing frame (16) is provided inside the housing (1) for limiting the rotation of the first rotating rod (12), the second rotating rod (13) and the fourth rotating rod (15); The fixed frame (16) is provided with a bending plate (161), the side surface of the shifting rod (64) is provided with a plurality of limiting teeth (642), and the hooks at both ends of the first torsion spring (65) are fixedly connected to the limiting teeth (642) and the bending plate (161) respectively.

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