阅读说明：本技术 双稳态开关 (Bistable switch ) 是由 车佳宇 林小军 陈钱林 李伟 洪佳崎 陈泽龙 刘春青 谢翔 熊伟庆 陈仁宗 陈悉 于 2020-12-24 设计创作，主要内容包括：本发明公开了一种双稳态开关,包括外壳,所述外壳内设置有线圈架、两个接线柱以及接触桥,所述线圈架设置有一中空套管以及线圈绕组,所述中空套管内设置有静铁芯和动铁芯,接触桥与动铁芯之间固定连接有导杆,所述线圈架上设置有用于保持动铁芯和静铁芯吸合或释放状态的稳态组件,稳态组件包括复位弹簧、用于抵压接触桥的压力弹簧以及用于加强动铁芯电磁吸力的永磁块。本发明提供了一种结构简单,具有稳定导通以及稳定断开的双重稳定状态,无需线圈持续供电,线圈不发热,保证开关内部温度与外部环境温度动态平衡,尤其是在极冷的恶劣环境下,能够正常通断,解决行业内极冷环境下汽车无法正常启动的问题,有效提高开关使用寿命的双稳态开关。(The invention discloses a bistable switch which comprises a shell, wherein a coil frame, two binding posts and a contact bridge are arranged in the shell, the coil frame is provided with a hollow sleeve and a coil winding, a static iron core and a movable iron core are arranged in the hollow sleeve, a guide rod is fixedly connected between the contact bridge and the movable iron core, a stable assembly used for keeping the movable iron core and the static iron core in an attraction or release state is arranged on the coil frame, and the stable assembly comprises a reset spring, a pressure spring used for abutting against the contact bridge and a permanent magnet used for strengthening the electromagnetic attraction of the movable iron core. The bistable switch provided by the invention has a simple structure, has double stable states of stable conduction and stable disconnection, does not need continuous power supply of the coil, does not generate heat, ensures dynamic balance between the internal temperature of the switch and the external environment temperature, can be normally switched on and off particularly in an extremely cold severe environment, solves the problem that an automobile cannot be normally started in an extremely cold environment in the industry, and effectively prolongs the service life of the switch.)

1. A bistable switch, includes the shell, be provided with coil former, two terminals and be used for connecting the contact bridge of terminal in the shell, its characterized in that: the coil former is provided with a cavity sleeve pipe and convolutes the coil winding who sets up at cavity sleeve pipe lateral wall, be provided with quiet iron core in the cavity sleeve pipe and move the iron core, move the iron core and slide and set up at the cavity sleeve pipe, contact the bridge and move fixedly connected with guide arm between the iron core, be provided with on the coil former and be used for keeping moving the steady state subassembly of iron core and quiet iron core actuation or release state, steady state subassembly includes that the butt is moving reset spring, butt that the iron core resets between iron core and quiet iron core and be used for supporting the pressure spring of pressure contact bridge and set up the permanent magnetism piece that is used for strengthening moving iron core electromagnetic attraction on the line path is felt to magnetism.

2. The bistable switch of claim 1, wherein: the coil former includes the U type magnetic conduction board that is formed by steel sheet bending type, the cavity sleeve pipe sets up perpendicularly on the bottom plate of U type magnetic conduction board and to the opening part extension, the bilateral symmetry of cavity sleeve pipe is provided with permanent magnetism piece, both sides be provided with first magnetic conduction piece between the both sides board of permanent magnetism piece and U type magnetic conduction board respectively, both sides be provided with the second magnetic conduction piece between permanent magnetism piece and the cavity sleeve pipe respectively.

3. The bistable switch of claim 2, wherein: the height of the end face of the permanent magnet block facing the bottom plate relative to the bottom plate is larger than the vertical height of the static iron core relative to the bottom plate, and the height difference is larger than the opening distance stroke between the movable iron core and the static iron core.

4. The bistable switch of claim 2 or 3, wherein: the side wall of the hollow sleeve extends towards the two side plates of the U-shaped magnetic conduction plate to form installation parts for sequentially embedding the first magnetic conduction block, the permanent magnet block and the second magnetic conduction block.

5. The bistable switch of claim 4, wherein: the first magnetic conduction blocks, the permanent magnets and the second magnetic conduction blocks are sequentially embedded and mutually abutted, the first magnetic conduction blocks and the permanent magnets are in long strip shapes, and the second magnetic conduction blocks are provided with arc surfaces matched with the side walls of the hollow sleeve.

6. The bistable switch of claim 1, wherein: the coil winding comprises a first coil group used for attracting or releasing the movable iron core and the static iron core.

7. The bistable switch of claim 1, wherein: the coil winding comprises a second coil group used for attracting the movable iron core and the static iron core and a third coil group used for releasing the movable iron core and the static iron core, and the number of the coils of the second coil group is larger than that of the third coil group.

8. The bistable switch of claim 7, wherein: and the negative end of the second coil group is connected with the negative end of the third coil group.

9. The bistable switch of claim 7 or 8, wherein: and the shell is provided with a circuit board, and the positive and negative electrodes of the second coil group and the third coil group are electrically connected with the circuit board through pins.

Technical Field

The invention belongs to the technical field of switches, and particularly relates to a bistable switch.

Background

The power supply main switch of the automobile is generally divided into an electromagnetic type and a mechanical type, wherein the electromagnetic type is that a control switch is communicated with an electromagnetic coil loop, and a movable contact and a fixed contact are connected by utilizing electromagnetic attraction force, so that the electric load of the whole automobile is communicated with the power supply of the whole automobile. However, the existing electromagnetic power main switch only attracts the movable contact by electromagnetic attraction force, so that the movable contact is connected with the fixed contact, a large electromagnetic attraction force is required, a large coil, a large iron core and the like are required to meet the strength requirement of the electromagnetic attraction force, materials are wasted, and the problems of high price, heavy weight and the like of the existing electromagnetic power main switch are caused. Besides, the electromagnetic switch comprises a coil frame, a coil winding arranged on the coil frame, a movable iron core and a return spring, in order to enable the movable iron core to overcome the elasticity of the return spring and further ensure that the electromagnetic switch keeps a connection state, the coil needs to be electrified all the time, but when the coil is in a continuous power supply state, the coil can generate heat, and liquefied water is easily formed on the coil due to alternating cold and hot states in severe environments with extremely cold weather and extremely low temperature, so that the coil cannot work normally, the switch fails, and the automobile cannot be started normally.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the bistable switch which has a simple structure, has double stable states of stable on and stable off, does not need continuous power supply of a coil, does not generate heat, ensures the dynamic balance between the internal temperature of the switch and the external environment temperature, can be normally switched on and off particularly in an extremely cold severe environment, solves the problem that an automobile cannot be normally started in the extremely cold environment in the industry, and effectively prolongs the service life of the switch.

In order to achieve the purpose, the invention adopts the technical scheme that: the utility model provides a bistable switch, includes the shell, be provided with coil former, two terminals in the shell and be used for connecting the contact bridge of terminal, the coil former is provided with a cavity sleeve pipe and convolutes the coil winding that sets up at cavity sleeve pipe lateral wall, cavity sleeve intraductal be provided with quiet iron core and move the iron core, it slides and sets up at the cavity sleeve intraductal to move the iron core, contact bridge and move fixedly connected with guide arm between the iron core, be provided with on the coil former and be used for keeping moving the steady state subassembly of iron core and quiet iron core actuation or release state, steady state subassembly is including setting up reset spring and setting up the permanent magnetism piece that is used for strengthening moving iron core electromagnetic attraction on magnetism sensing line path between moving iron core.

Adopt above-mentioned scheme, apply momentary forward voltage or reverse voltage to coil winding, when applying forward voltage, under the effect of circular telegram coil, it can slide towards quiet iron core direction to be located the cavity sleeve intraductal movable core, thereby form the actuation state, because quiet iron core keeps static fixed in the cavity sleeve, consequently quiet iron core still plays the spacing effect of stroke to moving the iron core, with move the iron core gliding together also through the guide rail with move the contact bridge of iron core linkage, make contact bridge and two terminal electricity even links, the switch switches on. Because the permanent magnet block in the steady-state component can provide extra magnetic force for the movable iron core, only an instant forward voltage needs to be given, when the electromagnetic attraction formed by the forward voltage can enable the movable iron core to overcome the elastic force of the reset spring to slide, and after the movable iron core is attracted to the static iron core, the acting force on the movable iron core (the magnetic force generated by the permanent magnet acts on the movable iron core) can be larger than the maximum elastic force of the reset spring, so that the purpose of stable attraction is achieved. The pressure spring has the main function that the contact bridge can be firmly pressed on the two binding posts through the elasticity of the pressure spring in a suction state to keep stable electrification. Therefore, if the movable iron core is released, reverse voltage is applied firstly, under the action of the electrified coil, the reverse voltage can enable the movable iron core to generate reverse electromagnetic force (opposite to the direction of the static iron core), the reverse electromagnetic force formed by the reverse voltage counteracts part of acting force (generated by the permanent magnet and acting on the movable iron core) already acting on the movable iron core, and then the acting force on the movable iron core can be smaller than the sum of the elastic force of the reset spring and the reverse acting force of the pressure spring, therefore, under the action of the elastic force of the reset spring and the reverse acting force of the pressure spring, the movable iron core resets, and the contact bridge is driven to reset, so that the two binding posts are disconnected, the switch is disconnected, and a stable release state is kept. In the whole working process, the coil winding only needs to be electrified instantly, so that the heat generated by the coil winding can be ignored under the condition of instant electrification, the purpose of no heating is achieved, and the normal on-off can be realized under the severe environment with extreme cold.

As a further arrangement of the present invention, the coil rack includes a U-shaped magnetic conductive plate formed by bending a steel plate, the hollow sleeve is vertically disposed on a bottom plate of the U-shaped magnetic conductive plate and extends toward the opening, the permanent magnets are symmetrically disposed on two sides of the hollow sleeve, first magnetic conductive blocks are respectively disposed between the permanent magnets on two sides and two side plates of the U-shaped magnetic conductive plate, and second magnetic conductive blocks are respectively disposed between the permanent magnets on two sides and the hollow sleeve.

By adopting the scheme, the U-shaped magnetic conduction plate formed by bending is simple in structure and convenient to process, and is made of a cold-rolled low-carbon steel plate, the hollow sleeve is vertically arranged on the bottom plate of the U-shaped magnetic conduction plate to enable the coil winding to be wound, the hollow sleeve is arranged at the center of the bottom plate to ensure that the formed magnetic field is uniformly distributed, permanent magnets are symmetrically arranged on two sides of the hollow sleeve, so that the magnetic force is more uniformly distributed, the magnetic pole directions of the permanent magnets are also radially and symmetrically arranged, and the permanent magnets and the U-shaped magnetic conduction plate can form a magnetic field path in a surrounding mode under the action of the first magnetic conduction block and the second magnetic conduction.

According to the further arrangement of the invention, the height of the end face of the permanent magnet block facing the bottom plate relative to the bottom plate is greater than the vertical height of the static iron core relative to the bottom plate, and the height difference is greater than the distance travel between the movable iron core and the static iron core.

By adopting the scheme, the permanent magnet blocks are arranged close to the movable iron core, and the sliding stroke and the opening stroke of the movable iron core are the same, so that when the opening stroke is smaller than the height difference, the magnetic force of the permanent magnet blocks can be always directly acted on the movable iron core along a magnetic field path, the maximization of the magnetic acting force on the movable iron core is ensured, the stability of the attraction state is ensured, and the attraction steady-state effect is optimal.

As a further arrangement of the invention, the side wall of the hollow sleeve extends towards the two side plates of the U-shaped magnetic conduction plate to form an installation part for sequentially embedding the first magnetic conduction block, the permanent magnet block and the second magnetic conduction block.

By adopting the scheme, the installation part is convenient for install the first magnetic conduction block, the permanent magnet block and the second magnetic conduction block, the thickness of the permanent magnet block can be changed through the installation part, the acting force acting on the movable iron core when the attraction state is changed is further changed, the fast thickness of the permanent magnet is larger, the acting force is increased, the thickness of the first magnetic conduction block is reduced according to the corresponding requirement, the structural improvement and the adjustment are more convenient and simple, the product scheme is diversified, different product requirements are met, and the application range is wider.

As a further arrangement of the invention, the first magnetic conduction block, the permanent magnet block and the second magnetic conduction block are sequentially embedded and mutually abutted, the first magnetic conduction block and the permanent magnet block are in strip shapes, and the second magnetic conduction block is provided with an arc surface matched with the side wall of the hollow sleeve.

By adopting the scheme, the mutual butt can ensure the continuity of the magnetic field, the first magnetic conduction block and the permanent magnet block are in a long strip shape and are convenient to process, and the second magnetic conduction block is provided with the arc surface, so that the structure is simple, the layout is reasonable, the magnetic field distribution is more uniform, and the formed magnetic force is more stable.

As a further arrangement of the invention, the coil winding comprises a first coil group used for attracting or releasing the movable iron core and the static iron core.

By adopting the scheme, the first coil group is applied with forward voltage, so that the movable iron core and the static iron core can form a suction state, otherwise, the first coil group is applied with reverse voltage, so that the movable iron core can be subjected to opposite electromagnetic force, and the movable iron core has acting force far away from the static iron core to form a release state.

The coil winding comprises a second coil group used for attracting the movable iron core and the static iron core and a third coil group used for releasing the movable iron core and the static iron core, and the number of the coils of the second coil group is larger than that of the third coil group.

Adopt above-mentioned scheme, through setting up two different coil groups, apply forward voltage in the twinkling of an eye for second coil group for move iron core and quiet iron core actuation, apply reverse voltage in the twinkling of an eye for third coil group, make and move iron core and relative quiet iron core release, after applying not equidirectional voltage, move the iron core and can form not equidimension and not equidirectional electromagnetic attraction, the convenience can be changed between actuation and release state.

As a further arrangement of the invention, the negative terminal of the second coil group is connected to the negative terminal of the third coil group.

By adopting the scheme, the wiring is reduced, so that the product is more convenient to install.

As a further configuration of the present invention, a circuit board is disposed on the housing, and the positive and negative electrodes of the second coil group and the third coil group are electrically connected to the circuit board through pins.

Adopt above-mentioned scheme, set up the circuit board on the shell to make the positive and negative electrode of second coil group and third coil group even electrically with the circuit board, when needs are applied to car main power with bistable switch, through the switching of circuit board, only need two wires just can realize being connected with car main power, reach the purpose that reduces the wiring, make things convenient for the product mounting, the product installation overall arrangement is more reasonable, is convenient for maintain the maintenance.

The invention is further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is an exploded view of an embodiment of the present invention;

FIG. 2 is a schematic external view of an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

fig. 4 is a sectional view of a portion B-B in fig. 2.

Detailed Description

The specific embodiment of the invention is shown in fig. 1-4, and a bistable switch comprises a housing 1, wherein a coil frame 11, two binding posts 12 and a contact bridge 13 for connecting the binding posts 12 are arranged in the housing 1, the coil frame 11 is provided with a hollow sleeve 14 and a coil winding 2 wound on the outer side wall of the hollow sleeve 14, a static iron core 3 and a movable iron core 4 are arranged in the hollow sleeve 14, the movable iron core 4 is arranged in the hollow sleeve 14 in a sliding manner, a guide rod 5 is fixedly connected between the contact bridge 13 and the movable iron core 4, a steady-state component 6 for keeping the movable iron core 4 and the static iron core 3 in an attracted or released state is arranged on the coil frame 11, the steady-state component 6 comprises a return spring 61 abutting between the movable iron core 4 and the static iron core 3 for returning the movable iron core 4, a pressure spring 62 abutting between the static iron core 3 and the contact bridge 13 for pressing the contact bridge 13, and a magnetic induction line path a for reinforcing the movable iron 4 permanent magnet 63 of electromagnetic attraction.

When the product is actually worked, exert momentary forward voltage or reverse voltage to coil winding 2, when exerting forward voltage, under the effect of circular telegram coil, it can slide towards quiet iron core 3 direction to be located cavity sleeve 14 internal movable iron core 4, thereby form the actuation state, because quiet iron core 3 keeps static fixed in cavity sleeve 14, consequently quiet iron core 3 still plays the spacing effect of stroke to moving iron core 4, with move iron core 4 gliding together also through guide rail and movable iron core 4 linkage contact bridge 13, make contact bridge 13 and two terminal 12 electricity even be connected, the switch switches on. Because the permanent magnet 63 in the steady-state component 6 can provide extra magnetic force for the movable iron core 4, we only need to provide an instantaneous forward voltage, and when the electromagnetic attraction force formed by the forward voltage can be enough to promote the movable iron core 4 to overcome the elastic force of the return spring 61 and slide, so as to ensure that the acting force on the movable iron core 4 (the magnetic force generated by the permanent magnet acts on the movable iron core 4) can be greater than the maximum elastic force of the return spring 61 after the movable iron core 4 is attracted to the static iron core 3, thereby achieving the purpose of steady state attraction. The main function of the pressure spring 62 is to firmly press the contact bridge 13 against the two terminals 12 by the elastic force of the pressure spring 62 in the attraction state, so as to maintain stable power-on. Therefore, if the movable iron core 4 is to be released, a reverse voltage is applied, under the action of the energized coil, the reverse voltage will make the movable iron core 4 generate a reverse electromagnetic force (opposite to the stationary iron core 3), and a part of the reverse electromagnetic force formed by the reverse voltage counteracts the acting force already acting on the movable iron core 4 (the magnetic force generated by the permanent magnet acts on the movable iron core 4), so that the acting force on the movable iron core 4 is smaller than the sum of the elastic force of the return spring 61 and the reverse acting force of the pressure spring 62, and therefore, under the action of the elastic force of the return spring 61 and the reverse acting force of the pressure spring 62, the movable iron core 4 is reset, so as to drive the contact bridge 13 to reset, so that the two terminals 12 are disconnected, the switch is disconnected. Wherein, the elastic force P1 of the return spring 61 is 5 ± 0.6N, and P2 is 7.1 ± 0.8N; the pressure spring 62P1 is 16 ± 1.5N, the P2 is 22.4 ± 2.3N, when the movable iron core 4 and the static iron core 3 are attracted, only the return spring 61 acts, the spring reaction force needs to be overcome and is 5 ± 0.6N, and the attraction voltage is required to be less than 16V; the pull-in condition is shown in table 1:

watch (1)

As shown in Table 1, when the product applies a forward voltage of 13V, the electromagnetic attraction force of the movable iron core 4 is 5.7N, which is greater than the maximum value of the initial reset force of the spring of 5.6N, and the product can start to attract, so that the attraction voltage of the product meets the requirement of less than 16V.

When releasing, the spring reaction force is 22.4+7.1 +/-0.8 +/-2.3 ═ 29.5 +/-3.1N, the reverse voltage is required to be 1V-6.5V, and the releasing working conditions are shown in Table 2:

watch (2)

As shown in table 2, the movable iron core 4 has electromagnetic attraction 29.2N under the condition of 1V reverse voltage of the coil, and the spring reaction 29.5 ± 3.1N in this state, so that the product has the risk that the iron core starts to operate when the reverse voltage is less than 1V, in addition, the spring reaction can maximally reach 32.6N, the iron core electromagnetic attraction 35.2N in the initial state, and the product is required to safely operate under 10G of vibration, so that the electromagnetic attraction to the movable iron core 4 can be improved by increasing the thickness of the permanent magnet, the risk that the iron core starts to operate when the reverse voltage is less than 1V is avoided, the steady-state effect of the product is improved, and the requirement of the reverse voltage is ensured to be 1V-.

In this embodiment, the coil bobbin 11 includes a U-shaped magnetic conductive plate 111 formed by bending a steel plate, the hollow sleeve 14 is vertically disposed on a bottom plate 1111 of the U-shaped magnetic conductive plate 111 and extends to an opening 1112, the permanent magnets 63 are symmetrically disposed on two sides of the hollow sleeve 14, first magnetic conductive blocks 7 are respectively disposed between the permanent magnets 63 on two sides and two side plates 1113 of the U-shaped magnetic conductive plate 111, and second magnetic conductive blocks 8 are respectively disposed between the permanent magnets 63 on two sides and the hollow sleeve 14. The U-shaped magnetic conduction plate 111 formed by bending is simple in structure and convenient to process, and is made of cold-rolled low-carbon steel plates, the hollow sleeve 14 is vertically arranged on the bottom plate 1111 of the U-shaped magnetic conduction plate 111, so that after the coil winding 2 is wound, the hollow sleeve 14 is arranged at the center of the bottom plate 1111, the formed magnetic field is ensured to be uniformly distributed, the permanent magnets 63 are symmetrically arranged on two sides of the hollow sleeve 14, the magnetic force can be more uniformly distributed, the magnetic pole directions of the permanent magnets 63 are also radially and symmetrically arranged, and the magnetic field and the U-shaped magnetic conduction plate 111 can form a magnetic field path under the action of the first magnetic conduction blocks 7 and the second magnetic conduction blocks 8.

The height of the end face of the permanent magnet 63 facing the bottom plate 1111, relative to the bottom plate 1111, is greater than the vertical height of the stationary iron core 3, relative to the bottom plate 1111, and the height difference x is greater than the distance y between the movable iron core 4 and the stationary iron core 3. The permanent magnet 63 is arranged close to the movable iron core 4, and the sliding stroke of the movable iron core 4 is the same as the opening stroke y, so that when the opening stroke y is smaller than the height difference x, the magnetic force of the permanent magnet 63 can always directly act on the movable iron core 4 along the magnetic field path, the maximization of the magnetic acting force on the movable iron core 4 is ensured, the stability of the attraction state is ensured, and the attraction steady state effect is optimal.

In this embodiment, the side wall of the hollow sleeve 14 extends towards the two side plates 1113 of the U-shaped magnetic conducting plate 111 to form a mounting portion 141 for sequentially embedding the first magnetic conducting block 7, the permanent magnet 63, and the second magnetic conducting block 8. The mounting portion 141 is provided with an insertion groove 1411. The installation department 141 is convenient for install first magnetic conduction piece 7, permanent magnetism piece 63 and second magnetic conduction piece 8, and the accessible changes the thickness of permanent magnetism piece 63 in installation department 141, and then acts on the effort on moving iron core 4 when changing the actuation state, the fast thickness of permanent magnetism is big more, the effort increases, certainly corresponding needs reduce the thickness of first magnetic conduction piece 7, the structural improvement adjustment seems convenient more simple, the product scheme is diversified, satisfy different product demands, application scope is wider.

In this embodiment, the first magnetic conducting block 7, the permanent magnet 63, and the second magnetic conducting block 8 are sequentially embedded and abutted against each other, the first magnetic conducting block 7 and the permanent magnet 63 are in a strip shape, and the second magnetic conducting block 8 has an arc surface 81 adapted to the side wall of the hollow sleeve 14. Mutual butt can guarantee the continuity in magnetic field, and first magnetic conduction piece 7 and permanent magnetism piece 63 are rectangular form convenient processing, and second magnetic conduction piece 8 sets up arc surface 81, simple structure, and is rationally distributed, and magnetic field distribution is more even, and the magnetic force of formation is more stable.

In the present embodiment, the coil winding 2 includes a second coil group 21 for attracting the movable iron core 4 and the fixed iron core 3, and a third coil group 22 for releasing the movable iron core 4 and the fixed iron core 3, and the number of coils of the second coil group 21 is greater than that of the third coil group 22. The second coil set 21 turns 980, the resistance 10.8 ohms, the third coil set 22 turns 580, the resistance 10.2 ohms. By arranging two different coil groups, after voltages in different directions are applied, the movable iron core 4 can form electromagnetic attraction in different sizes and different directions, and the attraction and release states can be conveniently switched.

In the present embodiment, the negative terminal of the second coil group 21 is connected to the negative terminal of the third coil group 22.

As a further configuration of the present embodiment, a circuit board (not shown in the figures) is disposed on the housing 1, and the positive and negative electrodes of the second coil group 21 and the third coil group 22 are electrically connected to the circuit board through pins. Set up the circuit board on shell 1 to make the positive and negative electrode of second coil group 21 and third coil group 22 even link with the circuit board electricity, when needs are applied to car main power with bistable switch, through the switching of circuit board, only need two wires just can realize being connected with car main power, reach the purpose that reduces the wiring, make things convenient for the product installation, the product installation overall arrangement is more reasonable, is convenient for maintain the maintenance.

Another embodiment of the present invention is different from the first embodiment only in that: the coil winding comprises a first coil group used for attracting or releasing the movable iron core and the static iron core.

The first coil group is applied with forward voltage, so that the movable iron core and the static iron core can form a suction state, and conversely, the first coil group is applied with reverse voltage, so that the movable iron core can be subjected to opposite electromagnetic force, and the movable iron core has acting force far away from the static iron core to form a release state.

The present invention is not limited to the above embodiments, and those skilled in the art can implement the present invention in other embodiments according to the disclosure of the present invention, or make simple changes or modifications on the design structure and idea of the present invention, and fall into the protection scope of the present invention.