A small circuit breaker

Abstract

The present application relates to the field of circuit breakers, and specifically discloses a small circuit breaker, which includes a housing, an operating mechanism arranged in the housing, and a snap-on release for realizing short-circuit protection, wherein the operating mechanism includes a lock, and the snap-on release includes a yoke arranged in the housing, an armature arranged on the yoke, and a reset elastic member for driving the armature to reset, wherein one end of the armature is rotatably arranged on the yoke, and the other end of the armature is movable and used for locking the lock, and further includes an energy storage mechanism, wherein the energy storage mechanism includes an energy storage elastic member for driving the armature to rotate, and when the armature is in conflict with the lock, the energy storage elastic member is used to apply a force to the armature to drive the armature to rotate in a direction close to the yoke. The present application has the effect of increasing the rotation speed of the armature during a short circuit.

Description

Technical Field

[0001] The present application relates to the field of circuit breakers, and in particular to a miniature circuit breaker. Background Art

[0002] A circuit breaker is an electrical device used for circuit protection, mainly used to provide overload and short circuit protection in home, commercial and industrial places.

[0003] The electromagnetic release is a part of the circuit breaker and is used to achieve circuit breaking protection. The snap-on release is a type of electromagnetic release. The snap-on release includes a yoke, an armature rotatably set in the circuit breaker housing, and an operating mechanism for realizing opening and closing. The operating mechanism includes a contact seat, a lock, a tripping catch, and a moving contact. The lock and the tripping catch are rotatably set on the contact seat, and the moving contact is fixed on the contact seat. When a short circuit occurs, the magnetism of the yoke increases to attract the armature to rotate toward the yoke, the armature rotates and hits the lock, the lock rotates to unlock the tripping catch, the contact seat rotates and drives the moving contact to rotate, thereby achieving opening.

[0004] The small space inside the housing of the miniature circuit breaker results in a small space for the armature to rotate, which affects the speed and force of the armature hitting the contact seat. This reduces the reliability of the armature unlocking the lock, and also affects the time required for the moving contact and the stationary contact to separate. Summary of the invention

[0005] In order to increase the rotation speed of the armature during a short circuit, the present application provides a small circuit breaker.

[0006] A miniature circuit breaker provided in this application adopts the following technical solution:

[0007] A small circuit breaker comprises a housing, an operating mechanism arranged in the housing, and a snap-on release for realizing short-circuit protection, wherein the operating mechanism comprises a lock, and the snap-on release comprises a yoke arranged in the housing, an armature arranged on the yoke, and a resetting elastic member for driving the armature to reset, wherein one end of the armature is rotatably arranged on the yoke, and the other end of the armature is movable and used for contacting the lock, and further comprises an energy storage mechanism, wherein the energy storage mechanism comprises an energy storage elastic member for driving the armature to rotate, and when the armature contacts the lock, the energy storage elastic member is used to apply a force to the armature to drive the armature to rotate in a direction close to the yoke.

[0008] By adopting the above technical solution, after the circuit short-circuit occurs and is resolved, under the action of the reset elastic member, the armature resets the energy storage elastic member to store energy. When the circuit short-circuits, the magnetism of the yoke increases and attracts the armature, and the armature overcomes the force of the reset elastic member and rotates toward the yoke. The energy storage elastic member releases energy and applies a force to the armature to drive the armature to rotate toward the yoke. Under the action of the energy storage elastic member, the armature accelerates and hits the lock buckle, the buckle is unlocked, the contact seat rotates and drives the moving contact to rotate to achieve opening.

[0009] Such a setting increases the rotation speed of the armature and the impact force of the armature on the lock when opening the switch, which not only improves the reliability of the armature unlocking the lock, but also shortens the separation time between the moving contact and the static contact, that is, the circuit can be disconnected more quickly, thereby improving the protection against short circuits.

[0010] Optionally, the energy storage mechanism further includes a telescopic component, the energy storage elastic member is a spring, the energy storage elastic member is sleeved on the telescopic component, the telescopic component can be telescopic and its own telescopic direction is consistent with the telescopic direction of the energy storage elastic member, and the two ends of the telescopic component along its own telescopic direction are respectively rotatably arranged on the housing and the armature

[0011] By adopting the above technical solution, the telescopic assembly guides the telescopic elastic member to extend and retract, and avoids the energy storage elastic member from twisting and bending during the telescopic process, so as to ensure that the telescopic elastic member can stably apply force to the armature when the gate is opened. At the same time, the telescopic assembly can also improve the stability of the armature rotation, so that the armature can hit the lock buckle at the best angle and stably transfer the force it receives to the lock buckle.

[0012] Optionally, the telescopic assembly includes a telescopic rod and a telescopic sleeve, and the telescopic sleeve sliding sleeve is arranged on the telescopic rod.

[0013] By adopting the above technical solution, the expansion and contraction of the energy storage elastic member is guided by the combination of the rod and the sleeve. Firstly, the structure is simple. Secondly, it is easy to assemble. Thirdly, it is not easy to interfere with the expansion and contraction of the energy storage elastic member.

[0014] Optionally, the outer wall of the telescopic sleeve is provided with a through groove connected to the inner cavity of the telescopic sleeve.

[0015] By adopting the above technical solution, the through groove connects the inner cavity of the telescopic sleeve with the outer wall of the telescopic sleeve, so that a relatively closed space is avoided in the telescopic sleeve when the telescopic rod is inserted into the telescopic sleeve, thereby ensuring the relative free sliding between the telescopic rod and the telescopic sleeve, and minimizing the interference of the telescopic assembly with the energy storage elastic member.

[0016] Optionally, a plurality of through grooves are provided.

[0017] By adopting the above technical solution and setting multiple through grooves, it is further ensured that the inner cavity of the telescopic sleeve is connected with the outside of the telescopic sleeve, so as to avoid the sliding blockage between the telescopic rod and the telescopic sleeve as much as possible.

[0018] Optionally, the energy storage mechanism also includes a first spring seat arranged at one end of the telescopic assembly and a second spring seat arranged at the other end of the telescopic assembly, the first spring seat is rotatably arranged on the armature, the second spring seat is rotatably arranged on the housing, the energy storage elastic member is arranged between the first spring seat and the second spring seat, the energy storage elastic member is a spring, one end of the energy storage elastic member is pressed against the first spring seat, and the other end of the energy storage elastic member is pressed against the second spring seat.

[0019] By adopting the above technical solution, compared with the two ends of the energy storage elastic member being directly rotationally connected with the armature and the housing, one end of the energy storage elastic member is rotationally set on the armature through the first spring seat, and the other end of the energy storage elastic member is rotationally set on the housing through the second spring seat. This not only facilitates the installation of the energy storage elastic member, but also avoids the influence on the rotation of the armature as much as possible.

[0020] Optionally, the armature includes a main body and a flapping block connected to one end of the main body.

[0021] By adopting the above technical solution, a beating block is extended from the main body for the beating part of the lock, which saves the raw materials required for the armature and reduces the beating area to avoid interference from the shell as much as possible.

[0022] Optionally, the main body, the beating block and the shell enclose a telescopic space, and the energy storage mechanism is arranged in the telescopic space.

[0023] By adopting the above technical solution and setting the armature structure, space is freed up in the shell to facilitate the setting of the energy storage mechanism, so that the shell does not need to be expanded in volume for setting the energy storage mechanism, thereby ensuring the miniaturization of the overall volume of the circuit breaker.

[0024] Optionally, the main body includes a rotating part and a hinged part, the hinged part is provided with a clearance groove on the end surface facing the lock, the hinged part is connected to the rotating part and arranged in the clearance groove, and the first spring seat is hinged on the hinged part.

[0025] By adopting the above technical solution, a clearance groove is provided on the rotating part, and a hinged part is provided in the clearance groove, so that part of the energy storage mechanism can be placed in the clearance groove. Such a setting can further free up space for the installation of the energy storage mechanism in the housing, which is convenient for the installation of the energy storage mechanism on the one hand, and can expand the expansion space of the energy storage elastic member on the other hand, which is helpful for the energy storage elastic member to store and release energy, thereby increasing the armature rotation speed when opening the gate.

[0026] Optionally, both the first spring seat and the second spring seat are provided with an articulated seat, the first spring seat is rotatably provided on the articulated portion through the articulated seat, the articulated portion is arranged at an inclination, one end of the articulated portion is connected to the rotating portion, and the other end of the articulated portion faces the yoke, the main body further comprises a limiting portion provided on the end of the articulated portion facing the yoke, the limiting portion is used to abut against the first spring seat, and a line passing through and perpendicular to the rotation axis of the rotating portion and the rotation axis of the articulated seat on the articulated portion is a rotation line;

[0027] When the first spring seat contacts the limiting portion, the expansion and contraction direction of the energy storage elastic member is parallel to the extension direction of the rotation line.

[0028] By adopting the above technical solution, after the circuit short circuit occurs and is resolved, the armature rotates and resets under the action of the reset elastic member. As the armature rotates, the energy storage elastic member compresses and stores energy until the first spring seat conflicts with the limit portion. Under the action of the telescopic assembly, the first spring seat and the second spring seat, the armature cannot continue to rotate at this time, and the rotation line is parallel to the telescopic direction of the energy storage elastic member, that is, the energy storage elastic member is in the maximum compression state.

[0029] When a short circuit occurs, the armature begins to rotate under the attraction of the magnetic yoke. When the armature rotates slightly, the rotation line is offset from the expansion and contraction direction of the energy storage elastic member. The energy storage elastic member releases energy and exerts a force on the armature to drive the armature to rotate toward the magnetic yoke. Under the attraction of the magnetic yoke and the combined action of the energy storage elastic member, the armature rotates quickly and hits the lock buckle, thereby achieving the opening of the gate.

[0030] Such a configuration enables the energy storage elastic member to be in the maximum energy storage state before a short circuit occurs. On the one hand, in the maximum energy storage state, the maximum force can be released when releasing energy, that is, the driving effect of the energy storage elastic member on the armature is maximized; on the other hand, the energy storage elastic member is prevented from compressing and storing energy when the armature is attracted by the magnetic yoke and rotates, thereby reducing the loss of the armature's kinetic energy.

[0031] When a torsion spring is used as the reset elastic member, in order to limit the relative movement of the reset elastic member to the armature and ensure that the reset elastic member resets the armature stably, the two force-bearing ends of the reset elastic member need to be kept tightly against the armature and the housing. That is, when the yoke can attract the armature to move during a short circuit, the torsion of the reset elastic member requires redundant space to achieve stable reset of the armature. In addition, the reset elastic member is prone to fatigue due to long-term use of the circuit breaker, and the torsion of the reset elastic member also requires redundant space.

[0032] Compared with the use of a reset elastic member with a smaller torque, the redundant space of the torque of the reset elastic member is reduced, and the force consumed when the armature rotates against the reset elastic member is reduced. On the one hand, it is difficult to ensure the stable reset of the armature, and on the other hand, it is difficult to ensure the long-term use requirements. It also makes it difficult to determine the specifications of the reset elastic member and requires special customization. By adopting the armature and energy storage mechanism of the present application, the reset elastic member can drive the energy storage elastic member to store energy and compress, and the armature can rotate when the magnetic yoke attracts the armature. There is no need to make special requirements on the specifications of the reset elastic member. It is often sufficient to select an energy storage elastic member that can be driven and compressed by the original reset elastic member on the basis of selecting the original reset elastic member.

[0033] In summary, the present application includes at least one of the following beneficial technical effects:

[0034] 1. When the armature is reset by the reset elastic member, the energy storage mechanism stores energy. When a short circuit occurs, the energy storage mechanism releases energy and applies force to the armature to accelerate the rotation of the armature, thereby shortening the separation time between the moving contact and the static contact, so that the circuit can be disconnected faster, thereby improving the protection effect against short circuit;

[0035] 2. The first spring seat and the second spring seat play an auxiliary role in the connection between the energy storage elastic member and the housing and the armature, and also help the energy storage elastic member to apply force to the armature; the telescopic assembly plays a guiding role in the telescopic movement of the energy storage elastic member and improves the stability of the armature swing;

[0036] 3. The limiting part can keep the energy storage elastic member in the maximum energy storage state each time it is reset. On the one hand, it can avoid the consumption of the armature rotation speed during short circuit, and on the other hand, it can maximize the driving effect of the energy storage elastic member on the armature. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of an embodiment of the present application.

[0038] Figure 2 It is a schematic diagram of the local structure of the highlighting operating mechanism in the embodiment of the present application.

[0039] Figure 3 It is a structural schematic diagram highlighting the lock in the embodiment of the present application.

[0040] Figure 4 It is a structural schematic diagram highlighting the reset torsion spring in the embodiment of the present application.

[0041] Figure 5 It is a structural schematic diagram highlighting the snap-on release in the embodiment of the present application.

[0042] Figure 6 It is a partial cross-sectional view highlighting the energy storage mechanism in the embodiment of the present application.

[0043] Figure 7 yes Figure 6 A magnified schematic diagram of center A.

[0044] Description of reference numerals:

[0045] 1. Shell; 2. Operating mechanism; 21. Contact seat; 22. Moving contact; 23. Jumper; 24. Lock; 241. Lock seat; 242. Lock hook; 243. Strike block; 25. Switch; 26. Reset torsion spring; 27. Connecting rod; 3. Snap-on release; 31. Yoke; 32. Armature; 321. Main body; 3211. Rotating part; 3212. Articulated part; 3213. Limiting part; 3214. Make way groove; 322. Snapping block; 33. Reset elastic member; 4. Terminal block; 41. Static contact; 5. Telescopic space; 6. Energy storage mechanism; 61. First spring seat; 62. Second spring seat; 63. Energy storage elastic member; 64. Telescopic assembly; 641. Telescopic rod; 642. Telescopic sleeve; 643. Through groove; 65. Articulated seat. DETAILED DESCRIPTION

[0046] The following is combined with Figure 1-7 This application is described in further detail.

[0047] The present application embodiment discloses a miniature circuit breaker. Figure 1 , Figure 2 The miniature circuit breaker comprises a housing 1, an operating mechanism 2 for realizing opening and closing of the circuit breaker, and a snap-on release 3 for realizing circuit breaker protection.

[0048] Reference Figure 2 The operating mechanism 2 includes a contact base 21 , two moving contacts 22 fixed on the contact base 21 , a trip button 23 rotatably arranged on the contact base 21 , and a lock button 24 for locking the trip button 23 .

[0049] Reference Figure 2 , Figure 3 The contact seat 21 is rotatably arranged in the housing 1, and the lock catch 24 includes a locking seat 241, a lock hook 242 and a striking block 243. The striking block and the lock hook 242 are integrally formed on the locking seat 241, and the locking seat 241 is rotatably arranged on the contact seat 21. The lock hook 242 cooperates with the jump catch 23 to achieve the locking of the jump catch 23. By rotating the lock catch 24, the lock hook 242 can release the locking of the jump catch 23.

[0050] Reference Figure 2 , Figure 4The operating mechanism 2 further includes a switch 25 rotatably disposed in the housing 1, a reset torsion spring 26 for driving the switch 25 to reset to disconnection, and a connecting rod 27 for connecting the switch 25 and the trip button 23. One of the force-bearing ends of the reset torsion spring 26 contacts the switch 25, and the other force-bearing end of the reset torsion spring 26 contacts the housing 1. One end of the connecting rod 27 is inserted on the switch 25, and the other end of the connecting rod 27 is inserted on the trip button 23. One end of the connecting rod 27 inserted on the switch 25 is eccentrically disposed with respect to the rotation axis of the switch 25, and one end of the connecting rod 27 inserted on the trip button 23 is eccentrically disposed with respect to the rotation axis of the trip button 23.

[0051] Reference Figure 3 , Figure 4 When opening, the striking block 243 is pushed, and the striking block 243 drives the lock hook 242 to rotate through the locking seat 241, and the lock hook 242 is separated from the tripping buckle 23 and the tripping buckle 23 is unlocked. Under the action of the reset torsion spring 26, the switch 25 is reset, and through the connecting rod 27 and the tripping buckle 23, the contact seat 21 rotates quickly and drives the moving contact 22 to move to the opening position.

[0052] Reference Figure 2 , Figure 3 A terminal block 4 is installed in the housing 1, one end of which extends out of the housing 1 and is used for wiring. Two stationary contacts 41 are fixed on the other end of the housing 1, and the two stationary contacts 41 are used to contact different moving contacts 22 respectively.

[0053] Reference Figure 2 , Figure 5 The snap-on release 3 includes a yoke 31, an armature 32 and a reset elastic member 33. The yoke 31 is fixed in the housing 1 and fixedly connected to the terminal block 4. The armature 32 includes a main body 321 and a slapping block 322. The main body 321 includes a rotating portion 3211, a hinged portion 3212 and a limit portion 3213. One end of the rotating portion 3211 is hinged on the armature 32. The slapping block 322 is arranged on the other end of the rotating portion 3211 and is used to abut against the struck block 243. The reset elastic member 33 is a torsion spring and is used to drive the armature 32 to reset. The reset elastic member 33 is sleeved on the hinge shaft of the rotating portion 3211. One of the force-bearing ends of the reset elastic member 33 abuts against the housing 1, and the other end of the reset elastic member 33 abuts against the rotating portion 3211.

[0054] Reference Figure 5 , Figure 6The end surface of the rotating part 3211 facing the lock buckle 24 is provided with a clearance groove 3214, and the hinge part 3212 is located in the clearance groove 3214. The hinge part 3212 is arranged obliquely, one end of the hinge part 3212 is connected to the rotating part 3211, and the other end of the hinge part 3212 faces the yoke 31 and is connected to the limiting part 3213. The rotating part 3211, the hinge part 3212, the limiting part 3213 and the slapping block 322 are integrally formed, and the rotating part 3211, the groove wall of the clearance groove 3214, the hinge part 3212, the limiting part 3213, the slapping block 322 and the housing 1 enclose a telescopic space 5.

[0055] Reference Figure 6 , Figure 7 An energy storage mechanism 6 is provided in the telescopic space 5, and the energy storage mechanism 6 is used to apply a force to the armature 32 to drive the armature 32 to rotate in a direction close to the yoke 31. The energy storage mechanism 6 includes a first spring seat 61, a second spring seat 62, an energy storage elastic member 63 provided between the first spring seat 61 and the second spring seat 62, and a telescopic assembly 64 for guiding the telescopic movement of the energy storage elastic member 63.

[0056] Reference Figure 6 , Figure 7 The first spring seat 61 and the second spring seat 62 are both fixed with an articulated seat 65. The first spring seat 61 is articulated on the articulated portion 3212 through the articulated seat 65, and the second spring seat 62 is articulated on the housing 1 through the articulated seat 65. The line passing through and perpendicular to the rotation axis of the rotating portion 3211 and the rotation axis of the articulated seat 65 on the articulated portion 3212 is the rotation line.

[0057] Reference Figure 7 The telescopic assembly 64 includes a telescopic rod 641 and a telescopic sleeve 642. The telescopic rod 641 is fixed on the first spring seat 61, the telescopic sleeve 642 is fixed on the second spring seat 62, and the telescopic sleeve 642 is slidably sleeved on the telescopic rod 641. Two through grooves 643 are provided on the outer wall of the telescopic sleeve 642. The through grooves 643 are connected to the inner cavity of the telescopic sleeve 642. The two through grooves 643 are evenly distributed in the circumferential direction around the axis of the telescopic sleeve 642. The telescopic rod 641 located in the telescopic sleeve 642 is connected to the outside of the telescopic sleeve 642 through the through grooves 643.

[0058] Reference Figure 7 The energy storage elastic member 63 is located between the first spring seat 61 and the second spring seat 62. One end of the energy storage elastic member 63 is pressed against the first spring seat 61, and the other end of the energy storage elastic member 63 is pressed against the second spring seat 62. The energy storage elastic member 63 is a spring and is sleeved on the telescopic rod 641 and the telescopic sleeve 642. The relative sliding direction between the telescopic rod 641 and the telescopic sleeve 642 is the telescopic direction of the telescopic assembly 64. The telescopic direction of the telescopic assembly 64 is consistent with the telescopic direction of the energy storage elastic member 63.

[0059] Reference Figure 6 , Figure 7 When the first spring seat 61 contacts the limiting portion 3213 , the extending direction of the rotation line is parallel to the expansion and contraction direction of the energy storage elastic member 63 .

[0060] The implementation principle of a small circuit breaker in the embodiment of the present application is as follows: when short-circuited, the yoke 31 attracts the armature 32 to rotate in the direction close to the yoke 31. After the armature 32 rotates slightly, the energy storage elastic member 63 extends to release energy and applies force to the armature 32 to push the armature 32 to rotate faster. The slapping block 322 slaps on the struck block 243, and through a series of linkages of the operating mechanism 2, the moving contact 22 rotates to separate from the static contact 41, thereby achieving the opening of the circuit breaker.

[0061] When the circuit returns to normal, under the action of the reset elastic member 33, the armature 32 is reset, the hinge portion 3212 drives the first elastic seat to reset through the hinge seat 65 on the first elastic member, the first elastic seat moves toward the second elastic seat, and the energy storage elastic member 63 is compressed until the first elastic seat conflicts with the limit portion 3213.

[0062] Such a configuration can increase the rotation speed of the armature 32 during a short circuit in a small space, shorten the separation time of the moving contact 22 and the stationary contact 41, and improve the protection effect. Moreover, the modification adaptability is strong, and there is no need to customize the reset elastic member 33 of special specifications.

[0063] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A miniature circuit breaker, comprising a housing (1), an operating mechanism (2) arranged in the housing (1), and a snap-on release (3) for realizing short-circuit protection, wherein the operating mechanism (2) comprises a lock (24), the snap-on release (3) comprises a yoke (31) arranged in the housing (1), an armature (32) arranged on the yoke (31), and a resetting elastic member (33) for driving the armature (32) to reset, one end of the armature (32) being rotatably arranged on the yoke (31), and the other end of the armature (32) being movable and used to abut against the lock (24), characterized in that: It also includes an energy storage mechanism (6), the energy storage mechanism (6) including an energy storage elastic member (63) for driving the armature (32) to rotate, and when the armature (32) contacts the lock buckle (24), the energy storage elastic member (63) is used to apply a force to the armature (32) to drive the armature (32) to rotate in a direction close to the yoke (31); The energy storage mechanism (6) further comprises a telescopic component (64), the energy storage elastic member (63) being a spring, the energy storage elastic member (63) being sleeved on the telescopic component (64), the telescopic component (64) being capable of telescoping and its own telescopic direction being consistent with the telescopic direction of the energy storage elastic member (63), and the two ends of the telescopic component (64) along its own telescopic direction being rotatably arranged on the housing (1) and the armature (32) respectively.

2. A miniature circuit breaker according to claim 1, characterized in that: The telescopic assembly (64) comprises a telescopic rod (641) and a telescopic sleeve (642), and the telescopic sleeve (642) is slidably mounted on the telescopic rod (641).

3. A miniature circuit breaker according to claim 2, characterized in that: The outer wall of the telescopic sleeve (642) is provided with a through groove (643) which is connected with the inner cavity of the telescopic sleeve (642).

4. A miniature circuit breaker according to claim 3, characterized in that: The through grooves (643) are provided in plurality.

5. A miniature circuit breaker according to claim 1, characterized in that: The energy storage mechanism (6) further comprises a first spring seat (61) arranged at one end of the telescopic assembly (64) and a second spring seat (62) arranged at the other end of the telescopic assembly (64); the first spring seat (61) is rotatably arranged on the armature (32); the second spring seat (62) is rotatably arranged on the housing (1); the energy storage elastic member (63) is arranged between the first spring seat (61) and the second spring seat (62); the energy storage elastic member (63) is a spring; one end of the energy storage elastic member (63) is pressed against the first spring seat (61); and the other end of the energy storage elastic member (63) is pressed against the second spring seat (62).

6. A miniature circuit breaker according to claim 5, characterized in that: The armature (32) comprises a main body (321) and a beating block (322) connected to one end of the main body (321).

7. A miniature circuit breaker according to claim 6, characterized in that: The main body (321), the beating block (322) and the shell (1) enclose a telescopic space (5), and the energy storage mechanism (6) is arranged in the telescopic space (5).

8. A miniature circuit breaker according to claim 6, characterized in that: The main body (321) comprises a rotating part (3211) and a hinged part (3212); a clearance groove (3214) is provided on the end surface of the hinged part (3212) facing the lock buckle (24); the hinged part (3212) is connected to the rotating part (3211) and arranged in the clearance groove (3214); and the first spring seat (61) is hinged on the hinged part (3212).

9. A miniature circuit breaker according to claim 8, characterized in that: The first spring seat (61) and the second spring seat (62) are both provided with an articulated seat (65), the first spring seat (61) is rotatably provided on the articulated portion (3212) through the articulated seat (65), the articulated portion (3212) is arranged in an inclined manner, one end of the articulated portion (3212) is connected to the rotating portion (3211), and the other end of the articulated portion (3212) faces the yoke (31), the main body (321) further comprises a limiting portion (3213) provided on the end of the articulated portion (3212) facing the yoke (31), the limiting portion (3213) is used to contact with the first spring seat (61), and a line passing through and perpendicular to the rotation axis of the rotating portion (3211) and the rotation axis of the articulated seat (65) on the articulated portion (3212) is a rotation line; When the first spring seat (61) contacts the limiting portion (3213), the expansion and contraction direction of the energy storage elastic member (63) is parallel to the extension direction of the rotation line.

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