Direct-acting relay
Patent Information
- Application Number
- CN202522060190.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-24
- Publication Date
- 2026-09-29
- Estimated Expiration
- 2035-09-24
AI Technical Summary
[0003]传统直动式继电器的触点簧片与复位簧片为非对称或独立设计，存在以下问题：驱动力与复位力方向偏移，导电桥易倾斜或卡滞；簧片应力分布不均，机械寿命差；触点压力波动大，接触电阻不稳定导致易产生电弧烧蚀
[0015]本申请提供一种直动式继电器，包括壳体、导电桥、推杆以及第二弹性件。导电桥设有动触点，相应的，壳体内设有静触点，且静触点通过引出端引出到壳体外与外部电路相连接。推杆可以推动导电桥，从而带动动触点沿直线运动，进而使得动触点与静触点相接触或脱离。推杆的端部设有第一弹性件，推杆通过第一弹性件与导电桥弹性连接。当动触点与静触点接触时，推杆进一步靠近导电桥，从而使得第一弹性件被压缩，推杆的动能转化成第一弹性件的弹性势能，从而均匀的施加于导电桥的动触点设置端，使得导电桥的两侧受力均衡，避免了导电桥的卡滞、倾斜，第一弹性件的弹力也将作用在导电桥，从而保证了动触点与静触点可靠稳定的抵接。当动触点与静触点断开、推杆回退时，推杆会朝向上运动直至推板与壳体内侧的第二弹性件弹性抵接，此时，第二弹性件将被压缩，第二弹性件的弹性势能进一步增大，第二弹性件的弹性势能也将转化为动触点和静触点下一次结合的推力，减小了动触点与静触点结合所需的电磁力，从而有效降低了继电器的吸合电压。
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Figure CN224817064U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of relay technology, and in particular to a direct-acting relay. Background Technology
[0002] A direct-acting relay is an electromagnetic relay whose core characteristic is that the moving contact structure achieves contact closure and opening through linear motion, rather than through traditional rotation or lever mechanisms. This design gives direct-acting relays advantages such as large stroke, high magnetic holding force, high transmission efficiency, and compact structure. They are particularly suitable for applications with large contact gaps and high space requirements, such as in the electricity meter industry and in new energy applications like photovoltaic inverters, energy storage systems, and charging piles. The direct-acting relay uses the electromagnetic force generated by the electromagnetic system to drive the armature to move linearly, thereby causing the moving contact to make or separate from the stationary contact, achieving the circuit's control function.
[0003] Traditional direct-acting relays have asymmetrical or independent contact springs and reset springs, which have the following problems: the driving force and reset force are offset in direction, the conductive bridge is prone to tilting or jamming; the stress distribution of the springs is uneven, resulting in poor mechanical life; the contact pressure fluctuates greatly, and the contact resistance is unstable, which easily leads to arcing and erosion. Utility Model Content
[0004] This application proposes a direct-acting relay, which aims to provide a moving contact structure that can provide stable and reliable contact pressure between the moving and stationary contacts and reduce the electromagnetic force required for contact closure.
[0005] One embodiment of this application provides a direct-acting relay, comprising: The housing is equipped with stationary contacts; A conductive bridge, wherein the conductive bridge is provided with a moving contact, and each moving contact is disposed opposite to a stationary contact; A push rod, one end of which is provided with a push plate, and the push plate is provided with a first elastic element on the side facing away from the push rod. The push rod is movably connected to the conductive bridge, and the first elastic element elastically abuts against the conductive bridge. A second elastic element is disposed in the housing and located on the movement path of the push plate. The second elastic element is configured to elastically abut against the push plate during the retraction of the push rod.
[0006] In one embodiment, the housing is provided with a partition, the partition is provided with two snap-fit parts, the two snap-fit parts are provided on opposite sides of the push rod, and the two snap-fit parts are provided with snap-fit grooves facing each other; The second elastic element includes two spring pieces, one end of each spring piece is inserted into a snap-fit groove, and both spring pieces can abut against or disengage from the push plate.
[0007] In one embodiment, the spring includes a plug-in section, a deformation section, and a contact section connected in sequence. The plug-in section is plugged into the snap-fit groove. The plug-in section and the deformation section are arranged at an angle. The contact section has a first arc surface that can contact the push plate and slide relative to the push plate.
[0008] In one embodiment, the housing is provided with a partition, and the partition is provided with two fixing posts, which are located on opposite sides of the push rod; The second elastic element includes two springs, each spring being fixed to one of the fixed posts, and both springs being able to abut against or disengage from the push plate.
[0009] In one embodiment, the first elastic member includes an intermediate plate and two deformation arms, the two deformation arms being disposed on both sides of the intermediate plate and arranged at an included angle, and the two deformation arms abutting against the conductive bridge respectively.
[0010] In one embodiment, the direct-acting relay further includes a connection assembly, which includes a mounting bracket. The mounting bracket includes two vertical plates and a horizontal plate connecting the two vertical plates. The horizontal plate is connected to the push rod and is stacked with the intermediate plate. The ends of the two vertical plates away from the horizontal plate are both connected to the conductive bridge.
[0011] In one embodiment, the connecting assembly further includes a stop block disposed on the side of the conductive bridge facing away from the push rod, and the two vertical plates have a plug-in portion at the end away from the horizontal plate, and the two plug-in portions are plugged into the stop block.
[0012] In one embodiment, the direct-acting relay further includes a drive mechanism, the drive end of which is connected to the push rod and can drive the moving contact to abut or disengage from the stationary contact.
[0013] In one embodiment, the housing further includes a partition that divides the accommodating cavity into a first cavity and a second cavity, the driving mechanism being disposed in the first cavity, the conductive bridge and at least two stationary contacts being disposed in the second cavity, and the second elastic element being disposed in the second cavity.
[0014] In one embodiment, the driving mechanism includes a yoke, a coil frame, and an armature. The yoke is disposed in the receiving cavity. The coil frame is disposed on the yoke, and a winding is wound around the outer periphery of the coil frame, forming a motion channel. The armature is movably disposed in the motion channel, and one end of the armature is connected to the push rod.
[0015] This application provides a direct-acting relay, including a housing, a conductive bridge, a push rod, and a second elastic element. The conductive bridge has a moving contact, and correspondingly, the housing has a stationary contact, which extends out of the housing and connects to an external circuit. The push rod can push the conductive bridge, thereby causing the moving contact to move linearly, thus making the moving contact contact or disengage from the stationary contact. The end of the push rod has a first elastic element, and the push rod is elastically connected to the conductive bridge through the first elastic element. When the moving contact contacts the stationary contact, the push rod moves further closer to the conductive bridge, thereby compressing the first elastic element. The kinetic energy of the push rod is converted into the elastic potential energy of the first elastic element, which is then uniformly applied to the moving contact end of the conductive bridge, making the force on both sides of the conductive bridge balanced, avoiding jamming or tilting of the conductive bridge. The elastic force of the first elastic element also acts on the conductive bridge, thereby ensuring reliable and stable contact between the moving contact and the stationary contact. When the moving contact disconnects from the stationary contact and the push rod retracts, the push rod moves upward until the push plate elastically contacts the second elastic element inside the housing. At this time, the second elastic element is compressed, and its elastic potential energy further increases. The elastic potential energy of the second elastic element is also converted into the thrust for the next engagement of the moving contact and the stationary contact, reducing the electromagnetic force required for the engagement of the moving contact and the stationary contact, thereby effectively reducing the relay's pull-in voltage. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments or prior art of this application, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0017] Figure 1 A schematic diagram of the structure of an embodiment of the direct-acting relay provided in this application; Figure 2 This is a schematic diagram of the structure of the second elastic element in a direct-acting relay according to a first embodiment. Figure 3 This is a schematic diagram of the structure of a second embodiment of the second elastic element in a direct-acting relay; Figure 4 This is a schematic diagram of the drive mechanism in a direct-acting relay; Figure 5 This is an exploded schematic diagram of a direct-acting relay; Figure 6 for Figure 2 A schematic diagram of the structure of the second elastic element.
[0018] Explanation of icon numbers: 100. Direct-acting relay; 1. Housing; 11. Stationary contact; 111. First lead-out terminal; 112. Second lead-out terminal; 12. Partition; 13. Snap-in part; 131. Snap-in groove; 14. Fixing post; 1a. First cavity; 1b. Second cavity; 2. Conductive bridge; 21. Moving contact; 22. Connecting piece; 3. Push rod; 4. Push plate; 41. Riveting part; 5. First elastic element; 51. Intermediate plate; 52. Deformation arm; 6. Second elastic element; 61. Spring; 611. Insertion section; 612. Deformation section; 613. Contact section; 62. Spring; 7. Mounting bracket; 71. Insertion part; 8. Stop block; 8a. Slot; 9. Drive mechanism; 91. Yoke; 92. Coil frame; 93. Armature; 94. Winding; 95. Magnetic guide plate; 96. Coil lead-out terminal. Detailed Implementation
[0019] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of several embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.
[0020] It should be noted that if multiple embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.
[0021] Furthermore, if multiple embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0022] The direct-acting relay 100 is an electromagnetic relay whose core feature is that the moving contact structure achieves contact closure and opening through linear motion, rather than through traditional rotation or lever mechanisms. This design gives the direct-acting relay 100 advantages such as large stroke, large magnetic holding force, high transmission efficiency, and compact structure. It is particularly suitable for applications with large contact gaps and high space requirements, such as the electricity meter industry and photovoltaic inverters, energy storage systems, and charging piles in new energy applications. The direct-acting relay 100 drives the armature 93 to move linearly through the electromagnetic force generated by the electromagnetic system, thereby causing the moving contact 21 to contact or separate from the stationary contact 11, realizing the circuit control function. The contact springs and reset springs of traditional direct-acting relays 100 are asymmetrical or independently designed, which has the following problems: the driving force and reset force are offset in direction, and the conductive bridge 21 is prone to tilting or jamming; the stress distribution of the springs is uneven, resulting in poor mechanical life; the contact pressure fluctuates greatly, and the unstable contact resistance leads to easy arcing and erosion.
[0023] To address the aforementioned problems, this application proposes a direct-acting relay 100 to solve the technical issues mentioned above.
[0024] Please see Figure 1 In one embodiment of this application, the relay includes a housing 1, a conductive bridge 2, a push rod 3, and a second elastic element 6. The housing 1 has a stationary contact 11, and the conductive bridge 2 has a moving contact 21. Each moving contact 21 is disposed opposite to a stationary contact 11. One end of the push rod 3 has a push plate 4, and the side of the push plate 4 facing away from the push rod 3 has a first elastic element 5. The push rod 3 is movably connected to the conductive bridge 2, and the first elastic element 5 elastically abuts against the conductive bridge 2. The second elastic element 6 is disposed in the housing 1 and located on the movement path of the push plate 4. The second elastic element 6 is configured to elastically abut against the push plate 4 during the retraction of the push rod 3. The stationary contact 11 is led out to the outside of the housing 1 through a first lead-out end 111 and a second lead-out end 112, and connected to an external circuit.
[0025] This application provides a direct-acting relay 100, including a housing 1, a conductive bridge 2, a push rod 3, and a second elastic element 6. The conductive bridge 2 is provided with a moving contact 21, and correspondingly, the housing 1 is provided with a stationary contact 11, which is led out of the housing 1 and connected to an external circuit. The push rod 3 can push the conductive bridge 2, thereby causing the moving contact 21 to move linearly, and thus causing the moving contact 21 to contact or disengage from the stationary contact 11. The end of the push rod 3 is provided with a first elastic element 5, and the push rod 3 is elastically connected to the conductive bridge 2 through the first elastic element 5. When the moving contact 21 contacts the stationary contact 11, the push rod 3 moves closer to the conductive bridge 2, compressing the first elastic element 5. The kinetic energy of the push rod 3 is converted into the elastic potential energy of the first elastic element 5, which is then evenly applied to the moving contact 21 end of the conductive bridge 2. This ensures that the forces on both sides of the conductive bridge 2 are balanced, preventing the conductive bridge 2 from jamming or tilting. The elastic force of the first elastic element 5 also acts on the conductive bridge 2, ensuring a reliable and stable contact between the moving contact 21 and the stationary contact 11. When the moving contact 21 disconnects from the stationary contact 11 and the push rod 3 retracts, the push rod 3 moves upward until the push plate 4 elastically contacts the second elastic element 6 inside the housing 1. At this time, the second elastic element 6 is compressed, further increasing its elastic potential energy. This elastic potential energy is then converted into the thrust required for the next contact between the moving contact 21 and the stationary contact 11, reducing the electromagnetic force required for the contact between the moving contact 21 and the stationary contact 11 to engage, thereby effectively reducing the relay's pull-in voltage.
[0026] It should be noted that the second elastic element 6 can be an integral structure with the partition 12 in the middle of the housing 1, or it can be fixed to the side of the partition 12 facing the second cavity 1b of the housing 1 by means of snap-fit, bonding, welding, etc. This application does not limit this. The specific choice can be made by comprehensively weighing the material of the second elastic element 6, the required reset force, the process cycle and the reliability level: If the metal spring sheet 61 is made of the same material as the partition 12 and the force is small, it can be integrally injection molded or hot melt snap-fitted to save processes and reduce costs; when the reset force is large and long-term high temperature is required to maintain elasticity, stainless steel spring sheet 61 is selected and supplemented by laser welding or riveting to ensure the bonding strength and thermal aging life; if the elastic element is an engineering plastic or composite material, mechanical fitting of snap-fit + limit post is preferred to avoid thermal stress concentration; for occasions that need to be repaired or need to be adjustable online, detachable snap-fit or screw fixing is selected to take into account the convenience of maintenance.
[0027] This application proposes two structures for the second elastic element 6. Both of the following structures of the second elastic element 6 can achieve the following: providing a rebound force to reduce the electromagnetic force required for the moving contact 21 to combine with the stationary contact 11, thereby effectively reducing the relay's pull-in voltage.
[0028] First Embodiment Please see Figure 2 and combined Figure 6In the first embodiment, the partition 12 is provided with two snap-fit parts 13, which are located on opposite sides of the push rod 3. The two snap-fit parts 13 are provided with snap-fit grooves 131 facing each other. The second elastic member 6 includes two spring pieces 61, one end of each spring piece 61 is inserted into a snap-fit groove 131, and both spring pieces 61 can abut or disengage from the push plate 4. The reset force of the relay is provided by a pair of independent springs 61: the partition plate 12 is symmetrically punched or injection molded with snap-fit grooves 131 on both sides of the push rod 3. The spring 61 insertion section 611 is fixed when inserted into the groove, and the deformation section 612 extends obliquely and forms an arc contact section 613 at the top. When the coil is energized with reverse current and the push rod 3 retracts, the two sides of the push plate 4 first meet the contact section 613 of the spring 61. As it continues to move upward, it compresses the deformation section 612 to cause elastic bending, and the spring 61 stores reverse potential energy. Subsequently, the coil is energized again, and the push rod 3 only needs to overcome the rebound force released by the spring 61 to accelerate downward. The potential energy stored in the spring 61 is converted into an auxiliary pushing force, which is superimposed with the electromagnetic attraction force, causing the moving contact 21 to close in advance, thereby significantly reducing the pull-in voltage. At the same time, the symmetrically arranged springs 61 balance the force on the push plate 4, preventing the conductive bridge 2 from tilting or jamming.
[0029] Furthermore, the contact segment 613 in this application forms an arc-shaped contact surface, which can be further described in the following sections. Figure 6 After the contact section 613 is made into an arc surface, the contact between the push plate 4 and it changes from surface contact to near-line contact. The contact area is reduced sharply, and the coefficient of friction and the amount of wear debris decrease simultaneously. This not only reduces the wear of the spring 61 and extends the mechanical life, but also makes the rebound force curve more linear, avoids jamming or rebound, and ensures that the reset auxiliary action is smooth and the pull-in voltage reduction effect is consistent.
[0030] Second Embodiment Please see Figure 3 In the second embodiment, the housing 1 is provided with a partition 12, and the partition 12 is provided with two fixed posts 14, which are located on opposite sides of the push rod 3. The second elastic element 6 includes two springs 62, each spring 62 is fixed to a fixed post 14, and both springs 62 can abut or disengage from the push plate 4. The two cylindrical helical springs 62 are sleeved on the fixed posts 14 on both sides of the partition 12, and the axis of the springs 62 is parallel to the direction of movement of the push rod 3. When the coil is energized with a reverse current and the push rod 3 retracts, the push plate 4 presses down on the two springs 62 and compresses them to store energy. The springs 62 generate a linear rebound force in the same direction as the movement of the push rod 3. When the forward current is energized again, the springs 62 release the stored potential energy, which is superimposed in the same direction as the electromagnetic attraction force, pushing the push rod 3 to accelerate downward. The moving contact 21 closes in advance, thereby significantly reducing the pull-in voltage. The symmetrical arrangement of the springs 62 makes the force on the push plate 4 balanced, avoiding tilting or jamming, ensuring reliable reset and stable contact pressure.
[0031] In the technical solution of this application, in order to ensure the reliability of the engagement between the moving contact 21 and the stationary contact 11, the first elastic member 5 includes an intermediate plate 51 and two deformation arms 52 disposed at both ends of the intermediate plate 51. The two deformation arms 52 are symmetrically arranged about the intermediate plate 51 and are arranged at an angle. The ends of the two deformation arms 52 away from the intermediate plate 51 abut against the conductive bridge 2. When the moving contact 21 contacts the stationary contact 11, the push rod 3 moves closer to the conductive bridge 2, thereby compressing the two deformation arms 52. The kinetic energy of the push rod 3 is converted into the elastic potential energy of the two deformation arms 52, which is then uniformly applied to the moving contact 21 of the conductive bridge 2, so that the forces on both sides of the conductive bridge 2 are balanced, avoiding jamming or tilting of the conductive bridge 2. The elastic force of the two deformation arms 52 will also act on the conductive bridge 2, thereby ensuring a reliable and stable engagement between the moving contact 21 and the stationary contact 11.
[0032] Furthermore, when the moving contact 21 contacts the stationary contact 11, the first elastic element 5 is compressed, thereby generating downward pressure on the conductive bridge 2 to ensure reliable and stable contact between the moving contact 21 and the stationary contact 11. It should be noted that the angles between the two deformation arms 52 and the intermediate plate 51 can be any angle between 90° and 180°. This application does not impose any restrictions on this, and adjustments can be made adaptively based on the material used for the deformation arms 52, the required rebound force, and the overall dimensions of the relay product.
[0033] For mounting and securing the first elastic element 5 and the conductive bridge 2, the relay also includes a connection assembly, which includes a mounting bracket 7. For details, please refer to further details. Figure 5 The mounting bracket 7 has two insertion parts 71 at its downward-facing end. The connecting assembly also includes a stop block 8, which is located on the side of the conductive bridge 2 facing away from the push rod 3. The mounting bracket 7 is inserted into the slot 8a formed by the stop block 8 through the insertion parts 71, thereby achieving reliable fixation of the conductive bridge 2 and the first elastic member 5.
[0034] In the technical solution of this application, the push rod 3 is driven by the drive mechanism 9. Specifically, the drive mechanism 9 includes a yoke 91, a coil frame 92, and an armature 93. The yoke 91 is disposed in the first cavity 1a, the coil frame 92 is disposed on the yoke 91, and a winding 94 is wound around the outer periphery of the coil frame 92, forming a movement channel. The armature 93 is movably disposed in the movement channel, and one end of the armature 93 has an installation notch. The push rod 3 is fixed in the installation notch. The end of the coil frame 92 away from the push rod 3 is provided with a magnetic plate 95. When the winding 94 is energized, a magnetic field is generated and forms a closed magnetic circuit through the yoke 91 and the magnetic plate 95, thereby driving the armature 93 to move, which in turn drives the push rod 3, the conductive bridge 2, and the moving contact 21 to move, thereby realizing the closing or disengagement of the moving contact 21 from the stationary contact 11.
[0035] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.
Claims
1. A direct-acting relay, characterized in that, include: The housing is equipped with stationary contacts; A conductive bridge, wherein the conductive bridge is provided with a moving contact, and each moving contact is disposed opposite to a stationary contact; A push rod, one end of which is provided with a push plate, and the push plate is provided with a first elastic element on the side facing away from the push rod. The push rod is movably connected to the conductive bridge, and the first elastic element elastically abuts against the conductive bridge. A second elastic element is disposed in the housing and located on the movement path of the push plate. The second elastic element is configured to elastically abut against the push plate during the retraction of the push rod.
2. The direct-acting relay as described in claim 1, characterized in that, The housing is provided with a partition, and the partition is provided with two snap-fit parts. The two snap-fit parts are located on opposite sides of the push rod, and the two snap-fit parts are provided with snap-fit grooves facing each other. The second elastic element includes two spring pieces, one end of each spring piece is inserted into a snap-fit groove, and both spring pieces can abut against or disengage from the push plate.
3. The direct-acting relay as described in claim 2, characterized in that, The spring includes a plug-in section, a deformation section, and a contact section connected in sequence. The plug-in section is plugged into the snap-fit groove. The plug-in section and the deformation section are set at an angle. The contact section has a first arc surface, which can contact the push plate and slide relative to the push plate.
4. The direct-acting relay as described in claim 1, characterized in that, The housing is provided with a partition, and the partition is provided with two fixing posts, which are located on opposite sides of the push rod; The second elastic element includes two springs, each spring being fixed to one of the fixed posts, and both springs being able to abut against or disengage from the push plate.
5. The direct-acting relay as described in any one of claims 1 to 4, characterized in that, The first elastic element includes an intermediate plate and two deformation arms. The two deformation arms are respectively disposed on both sides of the intermediate plate and are arranged at an angle. The two deformation arms abut against the conductive bridge.
6. The direct-acting relay as described in claim 5, characterized in that, The direct-acting relay also includes a connection assembly, which includes a mounting bracket. The mounting bracket includes two vertical plates and a horizontal plate connecting the two vertical plates. The horizontal plate is connected to the push rod and is stacked with the intermediate plate. The ends of the two vertical plates away from the horizontal plate are both connected to the conductive bridge.
7. The direct-acting relay as described in claim 6, characterized in that, The connecting assembly further includes a stop block, which is located on the side of the conductive bridge facing away from the push rod. The two vertical plates have a plug-in portion at the end away from the horizontal plate, and the two plug-in portions are plugged into the stop block.
8. The direct-acting relay as described in any one of claims 1 to 4, characterized in that, The direct-acting relay also includes a drive mechanism, the drive end of which is connected to the push rod and can drive the moving contact to abut or disengage from the stationary contact.
9. The direct-acting relay as described in claim 8, characterized in that, The housing also includes a partition that divides the accommodating cavity into a first cavity and a second cavity. The driving mechanism is located in the first cavity, and the conductive bridge and at least two stationary contacts are located in the second cavity. The second elastic element is located in the second cavity.
10. The direct-acting relay as described in claim 9, characterized in that, The driving mechanism includes a yoke, a coil frame, and an armature. The yoke is disposed in the receiving cavity. The coil frame is disposed on the yoke, and a winding is wound around the outer periphery of the coil frame, forming a motion channel. The armature is movably disposed in the motion channel, and one end of the armature is connected to the push rod.