Magnetic latching relay and working method and short circuit protection method thereof

Abstract

The invention relates to a magnetic latching relay and a working method and a short-circuit protection method thereof. The magnetic latching relay comprises a base, an electromagnetic coil assembly, a magnetic steel assembly, a push rod, a static sheet and a first leading-out sheet, the tail end of the static sheet is provided with a static contact, the base is internally provided with a movable sheet for swinging and limiting and is electrically connected with the first lead-out sheet, and one end of the movable sheet is provided with a movable contact; the movable sheet pushing frame is provided with an upper swing arm, a hook part and a lower swing arm, the lower swing arm is linked with the push rod and swings back and forth, when the lower swing arm swings to a limiting end on one side, the upper swing arm abuts against one side of the movable sheet to limit swinging of the movable sheet, the movable contact abuts against the static contact to be connected in a guiding mode, and the movable sheet is provided with a protruding part stretching into the hook part of the movable sheet pushing frame; and when the moving plate pushing frame swings to the limiting end on the other side, the upper swing arm is released from abutting against one side of the moving plate, the hook part pushes the convex part to drive the moving plate to reversely swing in place, and the moving contact is separated from the static contact. The short-circuit protection method comprises the steps that the short-circuit protection electromagnetic assembly is arranged in the base, the push rod is pushed to link the movable contact to be separated from the static contact when the current exceeds the limit, and active power-off protection is achieved.

Description

Technical Field

[0001] This invention relates to the field of relays, specifically a magnetic latching relay, its operating method, and a short-circuit protection method. Background Technology

[0002] A magnetic latching relay is an automatic switch that, like other electromagnetic relays, automatically connects and disconnects circuits. However, unlike other relays, the normally closed or normally open state of a magnetic latching relay relies entirely on the action of a permanent magnet. The switching state transition is triggered by a pulse electrical signal of a certain width applied to the coil assembly. With the State Grid imposing higher electrical safety requirements on magnetic latching relays used in smart meters, the contact gap after disconnection must be greater than 5.5mm to ensure electrical safety and prevent short circuits caused by insufficient clearance. Furthermore, to ensure the built-in load switch of the energy meter can withstand a short-circuit current of 6000A, the magnetic latching force must be above 6N. To address this, existing technologies disclose several magnetic latching relays with contact gaps greater than 5.5mm. Examples include patent application publication number CN118965043A, published on May 9, 2025, entitled "Large Gap Magnetic Latching Relay"; application publication number CN118965044A, published on May 9, 2025, entitled "A Magnetic Latching Relay"; application publication number CN121148953A, published on December 16, 2025, entitled "A Magnetic Latching Relay and its Assembly Method"; and application publication number CN118173418A, published on June 11, 2024, entitled "A Magnetic Latching Relay and an Electric Meter".

[0003] All of the publicly available patent documents described above describe structural solutions for magnetic latching electromagnetic relays with increased contact gaps, but they have the following technical problems: One approach employs a oscillating drive scheme using a magnet assembly. This involves an electromagnetic coil assembly driving the magnet assembly to oscillate. The magnet assembly is designed with a long arm on one side, which directly drives or via a linkage to rotate the moving plate assembly, achieving a large gap between the moving and stationary contacts. While this scheme achieves a large contact gap and saves space, it places high demands on the magnetic holding force and electromagnetic driving force of the magnet assembly. This requires a large electromagnetic coil and high power to meet the power requirements, resulting in high cost and energy consumption. Furthermore, when the instantaneous current is large, the lack of an interlocking structure between the moving and stationary contacts means there is still a significant risk of them springing apart, indicating insufficient reliability.

[0004] II. A direct-drive scheme using magnet components involves an electromagnetic coil assembly driving a magnet component in a linear motion, which in turn pushes a movable bar or push rod. This linear motion of the movable bar or push rod then connects the moving contact with the stationary contact of the stationary plate. This scheme, by controlling the direct-drive stroke, can also meet the requirement of a large opening between the moving and stationary contacts during direct drive. However, this method also places high demands on the pushing force and magnetic holding force of the magnet component, resulting in relatively high cost and energy consumption. Furthermore, direct-drive schemes often employ multi-contact methods, requiring higher contact consistency to ensure reliable conductivity. A robust anti-bounce structure is also needed when the contacts are fully engaged to guarantee normal operation under instantaneous high current. Therefore, the overall structure is more complex, manufacturing is inconvenient, and costs are higher.

[0005] Third, the function is relatively simple and lacks an effective additional short-circuit protection structure. When the current is too large and the controller of the smart appliance fails to provide an effective pulse control signal to the magnetic latching relay, the magnetic latching relay will not be able to disconnect effectively, eventually causing the magnetic latching relay to melt and burn out at high temperature, which poses a significant safety hazard.

[0006] In summary, existing magnetic latching relays require increased electromagnetic driving force and magnetic holding force to achieve large opening distances, resulting in larger coil size, higher investment costs, and greater energy consumption. Furthermore, they lack short-circuit protection functionality. Therefore, improvements to existing magnetic latching relays are necessary. Summary of the Invention

[0007] To overcome the above-mentioned shortcomings, the purpose of this invention is to provide a magnetic latching relay, its operating method, and a short-circuit protection method in the art. This addresses the problems of existing similar products, which, due to space constraints, require high magnetic holding and electromagnetic driving forces from the magnetic steel assembly when using a swing-drive mechanism or a direct-drive mechanism with a movable bar and push rod. These issues result in high power consumption, complex structures with multi-contact connections in direct-drive schemes, cumbersome spatial layouts, large size, and high costs, and lack effective active short-circuit protection. This objective is achieved through the following technical solution.

[0008] A magnetic latching relay includes a base, an electromagnetic coil assembly fixed to the base, a magnet assembly that rotates due to changes in the magnetic poles of the electromagnetic coil assembly, and a push rod that reciprocates within the base as the magnet assembly rotates. The base is fixedly provided with a stationary plate and a first lead-out plate. The key structural feature is that the stationary plate has a stationary contact at its end, and a movable plate with a rotational limiting function is provided within the base. The movable plate and the first lead-out plate are electrically connected via a flexible wire. One end of the movable plate has a movable contact that abuts against the stationary contact when it rotates to its correct position. A movable plate push frame is provided on one side of the movable plate, rotating relative to the base. The movable plate push frame includes an upper swing arm... The hook and lower swing arm are linked and cooperate with the push rod in the base. When the lower swing arm slides back and forth with the push rod, the moving plate pusher frame reciprocates and rotates. When the moving plate pusher frame rotates to one side limit end, the end of the upper swing arm abuts against one side of the moving plate to restrict the rotation of the moving plate, keeping the moving contact of the moving plate and the stationary contact of the stationary plate in close contact and guidance. The moving plate has a protrusion on one side that extends into the hook of the moving plate pusher frame. When the moving plate pusher frame rotates to the other side limit end, the end of the upper swing arm of the moving plate pusher frame releases the abutment against one side of the moving plate, and the hook of the moving plate pusher frame pushes the protrusion to drive the moving plate to rotate in the opposite direction and into position, that is, the moving contact of the moving plate separates from the stationary contact of the stationary plate. The above structural design of the moving plate pusher frame provides sufficient space for the rotation of the moving plate in the base, thus meeting the space requirement for large-distance rotation of the moving plate and realizing a large distance between the moving contact and the stationary contact. Furthermore, the swing of the moving plate pusher serves two purposes: firstly, it uses a lever principle to push the moving plate to swing until the moving contact and stationary contact are firmly engaged; secondly, it effectively prevents the moving plate from rotating back after it has reached its position, thus locking it in place. This eliminates the need to increase the magnetic holding force of the magnet assembly to maintain the working state effectively. The moving and stationary contacts will not spring apart even during a sudden surge of current, ensuring reliable conduction. In addition, the clever cooperation between the hook of the moving plate pusher and the protrusion of the moving plate not only simplifies the structure and reduces space requirements, but also allows for effortless control of the moving plate's reversal, making the disconnection between the moving and stationary contacts more efficient and reliable.

[0009] A short-circuit protection electromagnetic component is fixedly installed within the base near the push rod. This component includes an electromagnetic coil and an electromagnet. One end of the electromagnetic coil is connected to the inner end of the first lead-out piece, and the other end is connected to a second lead-out piece fixed relative to the base. A push plate is integrated on one side of the push rod, extending into the space within the base where the short-circuit protection electromagnetic component is located, with the push plate's end face facing the moving iron core of the electromagnet. When the push rod slides until the moving contact of the moving piece connects with the stationary contact of the stationary piece, the push plate's end face falls within the pushing stroke range of the electromagnet's moving iron core. When the electromagnet's moving iron core changes from a reset state to a pushing state, it pushes the push plate, causing the push rod to slide until the moving contact of the moving piece separates from the stationary contact of the stationary piece. By adding this short-circuit protection electromagnetic component, the magnetic latching relay itself has reliable short-circuit protection, effectively addressing emergency situations such as electromagnetic coil failure or failure to receive a valid external pulse signal, and preventing the magnetic latching relay from melting and burning out due to high temperature.

[0010] Auxiliary springs are provided at both ends of the base corresponding to the sliding direction of the push rod. When the magnet assembly swings and pushes the push rod to slide into place, the push rod compresses the auxiliary spring at the corresponding end. The auxiliary spring has the function of storing energy when the push rod slides into place and providing initial auxiliary power when the push rod moves in the opposite direction, thereby reducing the electric driving force requirement of the electromagnetic coil assembly.

[0011] The upper swing arm of the moving plate pusher has a notch in the middle and swing arms on both sides. The moving plate has a waist in the middle that mates with the notch, and guide slopes on both sides of the waist that mate with the swing arms. When the moving plate pusher rotates to the point where the moving contact of the moving plate and the stationary contact of the stationary plate are in close contact, only the swing arm end of the upper swing arm abuts against one side of the moving plate. When the moving plate pusher rotates to the point where the moving contact of the moving plate and the stationary contact of the stationary plate are separated, the notch of the upper swing arm mates with the waist of the moving plate, and the swing arms on both sides of the notch of the upper swing arm form a guiding engagement with the guide slopes on both sides of the waist of the moving plate. Through this structure, by utilizing the inclined state of the guide slopes, the force contact state between the upper swing arm and the moving plate is changed, allowing the moving plate to form a larger stroke swing. Under the guiding action, pushing the moving plate is more effortless and smooth, improving the reliability and stability of the moving plate pusher driving the moving plate to swing.

[0012] The stationary plate extends into the base and has an integrally connected elastic conductive part at one end. The stationary plate and the elastic conductive part are connected in a U-shape. The elastic conductive part includes a conductive spring and a shunt plate with an arc-shaped cavity in the middle. One end of the conductive spring and the shunt plate is fixed to the end of the stationary plate, and the other end of the conductive spring and the shunt plate is simultaneously fixedly connected to the stationary contact. There is a gap between the stationary contact and the stationary plate inside the base. When the stationary plate is energized, the magnetic field generated exerts a pushing force on the elastic conductive part. The base limits the swing direction of the elastic conductive part under the pushing force. Through this structure, when the stationary plate conducts a large current, the generated magnetic force exerts a pushing force on the elastic conductive part towards the moving plate, thereby making the contact between the stationary contact and the moving contact more reliable. At the same time, this magnetic force has an arc-extinguishing effect on the arc generated when the moving contact separates from the stationary contact.

[0013] Arc-extinguishing plates are arranged within the base along the travel length between the moving contact of the moving plate and the stationary contact of the stationary plate. This structure enables effective arc extinguishing between the moving and stationary contacts.

[0014] The movable piece has plate shafts on both sides at one end, and the base has double-sector-shaped grooves that cooperate with the plate shafts to limit rotation. This structure enables the movable piece to swing and be limited relative to the base.

[0015] The magnet assembly integrates a swing arm, the end of which engages with an opening at one end of the push rod, and the lower swing arm of the moving plate pusher engages with an opening at the other end of the push rod. This structure enables the magnet assembly to swing, driving the push rod to slide, which in turn drives the moving plate pusher to swing. The structure is relatively simple and easy to manufacture and assemble.

[0016] The magnetic latching relay operates as follows: In the initial state, the moving contact of the moving piece and the stationary contact of the stationary piece are separated. At this time, the electromagnetic coil assembly is energized, causing the magnet assembly to rotate. The magnet assembly pushes the push rod to slide to one end, and the push rod drives the moving piece pusher frame to rotate. The upper swing arm of the moving piece pusher frame pushes the moving piece to rotate until the push rod slides to the limit end. At this point, the magnet assembly forms a magnetic attraction to hold the moving piece, and the moving piece pusher frame rotates to its position. The moving contact of the moving piece and the stationary contact of the stationary piece are pressed together to form a conductive connection. Simultaneously, a dead point is formed at the point where the upper swing arm of the moving piece pusher frame abuts the moving piece, restricting the reverse rotation of the moving piece and maintaining the moving contact of the moving piece and the stationary contact of the stationary piece. The contact is conductive, and the stationary piece and the first lead-out piece are connected through the moving piece and the flexible wire. When it is necessary to cut off the connection between the stationary piece and the lead-out piece, the electromagnetic coil assembly is controlled to be energized in reverse, which drives the magnet assembly to swing in reverse. The magnet assembly pushes the push rod to slide to the other end. The push rod drives the moving piece push frame to swing in reverse. The upper swing arm of the moving piece push frame releases the dead point state and pushes the protrusion of the moving piece through the hook, causing the moving piece to reverse until the push rod slides to the position. At this point, the magnet assembly forms a magnetic attraction to hold the moving piece, and the moving piece push frame swings in reverse to the position. The moving piece swings until the moving contact separates from the stationary contact of the stationary piece, thus disconnecting the stationary piece from the first lead-out piece.

[0017] The short-circuit protection method of this magnetic latching relay is as follows: In the initial state, the moving contact of the moving piece and the stationary contact of the stationary piece are separated. At this time, the electromagnetic coil assembly is energized, driving the magnet assembly to rotate. The magnet assembly pushes the push rod to slide to one end, and the push rod drives the moving piece pusher frame to rotate. The upper swing arm of the moving piece pusher frame pushes the moving piece to rotate until the push rod slides to the limit end. At this time, the magnet assembly forms a magnetic attraction to hold the moving piece, the moving piece pusher frame rotates to the position, and the moving contact of the moving piece and the stationary contact of the stationary piece are pressed together to form a conductive connection. The push plate end face of the push rod is close to the moving iron core of the electromagnet of the short-circuit protection electromagnetic assembly. At this time, a dead point is formed at the point where the upper swing arm of the moving piece pusher frame abuts the moving piece, restricting the reverse rotation of the moving piece, keeping the moving contact of the moving piece and the stationary contact of the stationary piece conductive. The second lead-out piece is connected to the moving piece and the flexible wire. In this state, when the current between the second lead-out piece and the stationary piece is greater than the set maximum value, the current passes through the electromagnetic coil of the short-circuit protection electromagnetic component. The electromagnetic coil pushes the moving iron core of the electromagnet against the push plate of the push rod, pushing the push rod to slide to the other end. The push rod drives the moving piece push frame to swing in the opposite direction. The upper swing arm of the moving piece push frame releases the dead point state and pushes the protrusion of the moving piece through the hook, causing the moving piece to reverse. When the push rod slides to the position, the magnet assembly forms a magnetic attraction and retains it. The moving piece push frame swings in the opposite direction to the position. The moving piece swings until the moving contact separates from the stationary contact of the stationary piece. The stationary piece is disconnected from the second lead-out piece. The moving iron core of the electromagnet resets instantly after the electromagnetic coil is de-energized, and the short-circuit protection process is completed.

[0018] The beneficial effects of this invention are as follows: I. By optimizing the internal swing-type structure of the magnetic latching relay, a large opening distance between the moving and stationary contacts is achieved within a limited volume space. It also has a self-locking effect during conduction. Without increasing the magnetic holding force of the existing magnet assembly, it can achieve a holding force of at least 6N between the moving and stationary contacts, ensuring that the moving and stationary contacts are not easily bounced apart. This meets the requirements of high reliability, high safety, and high current, while reducing the size and power consumption of the electromagnetic coil assembly.

[0019] Second, adopting a single-contact, large-contact solution eliminates the need to consider structural consistency issues compared to existing multi-contact solutions. The overall structure is simpler, making it easier to manufacture and assemble, and the investment cost is relatively low.

[0020] Third, an active short-circuit protection function has been added. Even if the electromagnetic coil assembly driving the magnet assembly is damaged or fails to receive a valid pulse signal, it still has the function of automatically disconnecting the circuit in the face of excessive current, which provides effective short-circuit protection for the magnetic latching relay, prevents the magnetic latching relay from melting and burning out at high temperature, and ensures the safety of electrical equipment.

[0021] IV. The magnetic steel assembly, push rod, moving plate push frame, and moving plate are designed based on the principle of saving force arm. Both ends of the push rod are equipped with auxiliary springs for energy storage. Therefore, the magnetic steel assembly can achieve efficient and reliable moving plate swing operation without large electromagnetic power. This not only reduces the size of the electromagnetic coil, but also reduces energy consumption, making the magnetic latching relay smaller in size and power consumption, thus achieving energy saving and emission reduction.

[0022] 5. The stationary contact end adopts a current-diverting conductive spring structure, which uses the magnetic field thrust when a large current is turned on to push the stationary contact and the moving contact to form a more reliable clamping force, thereby making the contact connection more reliable and safe. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the internal structure of Scheme 1 of the present invention.

[0024] Figure 2 yes Figure 1 Schematic diagram of the structure in the separated state of the moving contact and the stationary contact.

[0025] Figure 3 yes Figure 1 A schematic diagram of the moving plate pusher frame structure.

[0026] Figure 4 yes Figure 1 A schematic diagram of the moving plate structure.

[0027] Figure 5 This is a schematic diagram of the internal structure of Scheme 2 of the present invention.

[0028] Figure 6 yes Figure 5 Schematic diagram of the structure in the separated state of the moving contact and the stationary contact.

[0029] Figure 7 yes Figure 1 A schematic diagram of the structure for changing the style of the stationary plate and the first lead-out plate.

[0030] The numbers and names in the diagram are as follows: 1. Base, 101. Double sector groove, 2. Electromagnetic coil assembly, 3. Magnet assembly, 301. Swing rod, 4. Push rod, 401. Push plate, 5. Auxiliary spring, 6. Moving plate push frame, 601. Upper swing arm, 6011. Swing arm, 6012. Notch, 602. Hook, 603. Lower swing arm, 7. Moving plate, 701. Protrusion, 702. Plate shaft, 703. Waist, 704. Guide slope, 8. Moving contact, 9. Stationary plate, 10. Stationary contact, 11. Conductive spring, 12. Diverter plate, 13. First lead plate, 14. Flexible wire, 15. Arc extinguishing plate, 16. Electromagnet, 1601. Moving iron core, 17. Electromagnetic coil, 18. Second lead plate. Implementation

[0031] The present invention will now be further described with reference to the accompanying drawings.

[0032] like Figures 1-4 The following is an example of embodiment one. The magnetic latching relay includes a base 1, an electromagnetic coil assembly 2, a magnet assembly 3, a push rod 4, a moving plate pusher 6, a moving plate 7, a stationary plate 9, a first lead-out plate 13, and an arc-extinguishing assembly. The electromagnetic coil assembly is fixed inside the base and includes a coil support, an iron core, a coil (not shown in the figure), and a yoke. The iron core is located in the middle of the coil support, and the coil is wound around it. Bent yokes are provided at both ends of the coil support. The magnet assembly includes a housing that swings relative to the base. A permanent magnet is located inside the housing, and double-headed yokes that conduct magnetic energy to the permanent magnet are provided on both sides of the housing. The magnet assembly forms a magnetic attraction with the yokes at both ends of the electromagnetic coil assembly through the double-headed yokes on both sides, thus forming magnetic latching. The housing of the magnet assembly integrates a swing rod 301. When the electromagnetic coil assembly is energized to generate positive and negative electrical signals, it drives the swing rod to reciprocate relative to the base. The push rod slides linearly within the base. The end of the swing arm of the magnet assembly engages with the opening at one end of the push rod. As the magnet assembly swings back and forth, the push rod forms a linear reciprocating motion.

[0033] The base 1 is divided into left and right sections. The left side houses the electromagnetic coil assembly 2 and the magnet assembly 3. A sliding push rod 4 runs through the bottom between the two sections. The right side of the base houses the moving plate pusher 6, the moving plate 7, the stationary plate 9, the first lead-out plate 13, and the arc-extinguishing assembly. The portion of the stationary plate and the first lead-out plate extending beyond the base meets the existing relay installation requirements of the State Grid. Figure 1 , Figure 5 , Figure 7 Any style is acceptable; the end of the stationary plate is connected to an elastic conductive part that forms a U-shaped meandering structure. The elastic conductive part includes a conductive spring 11 and a shunt plate 12 with an arc-shaped cavity in the middle. One end of the conductive spring and the shunt plate is fixedly connected to the end of the stationary plate, and the other end of the conductive spring and the shunt plate is fixedly connected to the stationary contact 10. There is a gap between the stationary contact and the stationary plate inside the base. When the stationary plate is energized, the magnetic field formed thereon exerts a thrust on the conductive spring. The base limits the swing direction of the conductive spring under the action of the thrust.

[0034] The aforementioned moving piece 7 has plate shafts 702 on both sides at one end. These plate shafts cooperate with the double arc-shaped grooves 101 on the base 1 or the mounting plate inside the base to form a limited rotation, that is, the moving piece swings relative to the base in a limited manner. The moving piece and the first lead-out piece 13 are electrically connected by a welded flexible wire 14. The other end of the moving piece is fixedly provided with a moving contact 8 that abuts against the stationary contact 10 connected to the aforementioned stationary piece when the moving piece swings to its position in the forward direction. The aforementioned moving piece pusher 6 is provided on one side of the moving piece. The moving piece pusher 6 is provided with an upper swing arm 601, a hook 602, and a lower swing arm 603. The lower swing arm cooperates with an opening provided at the other end of the push rod inside the base. When the push rod slides back and forth, the moving piece pusher oscillates back and forth. When the moving plate pusher rotates to one side limit end, the end of the upper swing arm abuts against one side of the moving plate to restrict the rotation of the moving plate, keeping the moving contact of the moving plate and the stationary contact of the stationary plate in close contact and guiding. The moving plate is provided with a protrusion 701 extending into the hook of the moving plate pusher on one side. When the moving plate pusher rotates to the other side limit end, the end of the upper swing arm of the moving plate pusher releases the abutment against one side of the moving plate. The hook of the moving plate pusher pushes the protrusion to drive the moving plate to rotate in the opposite direction and into position, that is, the moving contact of the moving plate and the stationary contact of the stationary plate separate.

[0035] In the left side region of the base 1, auxiliary springs 5 ​​are provided at both ends corresponding to the sliding direction of the push rod 4. The auxiliary springs are installed in the spring seats integrated in the push rod. When the magnet assembly 3 swings and pushes the push rod to slide into place, the push rod compresses the auxiliary spring at the corresponding end, forming an energy storage effect. This can effectively reduce the initial thrust requirement when the magnet assembly swings and reduce energy consumption.

[0036] An arc-extinguishing component is provided on the upper part of the right side region of the base 1 in the direction of the travel of the moving contact 8 and the stationary contact 10. The arc-extinguishing component is an arc-extinguishing plate 15 arranged at intervals, and the arc-extinguishing plate is hollowed out to form a travel through hole to adapt to the swing of the moving contact.

[0037] To make the swing and deformation of the moving piece 7 more reliable, the upper swing arm 601 of the moving piece pusher 6 has a notch 6012 in the middle and swing arms 6011 on both sides. The moving piece has a waist 703 in the middle that mates with the notch, and guide slopes 704 on both sides of the waist that mate with the swing arms. When the moving piece pusher 6 swings to the point where the moving contact 8 of the moving piece and the stationary contact 10 of the stationary piece 9 are in close contact, only the end of the upper swing arm abuts against one side of the moving piece. When the moving piece pusher 6 swings to the point where the moving contact of the moving piece and the stationary contact of the stationary piece are separated, the notch of the upper swing arm mates with the waist of the moving piece, and the swing arms on both sides of the notch of the upper swing arm mate with the guide slopes on both sides of the waist of the moving piece. This allows the moving piece to have a larger swing stroke, and makes the moving piece pusher 6 push the moving piece more effortlessly and smoothly, thereby improving the reliability and stability of the swing of the moving piece.

[0038] like Figure 5 , Figure 6 The following is an embodiment two. Based on the above embodiment one, an area for installing a short-circuit protection electromagnetic component is added to the bottom of the base 1. This area is adjacent to the push rod 4 and has a partial conductive design. The short-circuit protection electromagnetic component includes an electromagnetic coil 17 and an electromagnet 16. One end of the electromagnetic coil is connected to the inner end of the first lead-out piece 13 or the above flexible wire 14. The other end of the electromagnetic coil is connected to the second lead-out piece 18, which is fixed relative to the base. A push plate 401 is integrated on one side of the push rod. The push plate extends into the space where the short-circuit protection electromagnetic component is located from the above-mentioned partially conductive part, and the end face of the push plate is opposite to the moving iron core 1601 of the electromagnet. When the push rod 4 slides to the point where the moving contact 8 of the moving piece 7 is connected to the stationary contact 10 of the stationary piece 9, the end face of the push plate of the push rod falls into the pushing stroke range of the moving iron core of the electromagnet. When the moving iron core of the electromagnet changes from the reset state to the pushing state, the push plate drives the push rod to slide until the moving contact of the moving piece and the stationary contact of the stationary piece are separated. This second embodiment features a dual-function design: when the stationary plate and the first lead are used for external power connection, it lacks active short-circuit protection; however, when the stationary plate and the second lead are used for external power connection, it provides active short-circuit protection. Therefore, the desired wiring method can be selected based on actual needs.

[0039] The magnetic latching relay operates as follows: In the initial state, the moving contact 8 of the moving piece 7 and the stationary contact 10 of the stationary piece 9 are separated. At this time, the electromagnetic coil assembly 2 is energized, causing the magnet assembly 3 to rotate. The magnet assembly pushes the push rod 4 to slide to one end, and the push rod drives the moving piece pusher 6 to rotate. The upper swing arm 601 of the moving piece pusher 6 pushes the moving piece to rotate until the push rod slides to the limit end. At this time, the magnet assembly forms a magnetic attraction to hold the moving piece, and the moving piece pusher 6 rotates to the correct position. The moving contact of the moving piece and the stationary contact of the stationary piece are pressed together to form a conductive connection. At this time, a dead point is formed at the point where the upper swing arm of the moving piece pusher 6 abuts the moving piece, restricting the reverse rotation of the moving piece and keeping the moving contact of the moving piece and the stationary contact of the stationary piece in contact. The stationary contact of the plate is connected, and the stationary plate and the first lead plate 13 are connected through the moving plate and the flexible wire 14. When it is necessary to cut off the connection between the stationary plate and the lead plate, the electromagnetic coil assembly is controlled to be energized in reverse, which drives the magnet assembly to swing in reverse. The magnet assembly pushes the push rod to slide to the other end. The push rod drives the moving plate push frame to swing in reverse. The upper swing arm of the moving plate push frame is released from the dead point state and pushes the protrusion 701 of the moving plate through the hook 602, which drives the moving plate to reverse until the push rod slides to the position. The magnet assembly forms a magnetic attraction and holds the moving plate. The moving plate push frame swings in reverse to the position. The moving plate swings until the moving contact separates from the stationary contact of the stationary plate, thus disconnecting the stationary plate from the first lead plate.

[0040] The short-circuit protection method of the magnetic latching relay is as follows: When the moving contact 8 of the moving piece 7 and the stationary contact 10 of the stationary piece 9 are pressed together to form a conductive state, the end face of the push plate 401 of the push rod 4 is close to the moving iron core 1601 of the electromagnet 16 of the short-circuit protection electromagnetic assembly. In this state, when the current between the second lead piece 18 and the stationary piece is greater than the set maximum value, the current passes through the electromagnetic coil 17 of the short-circuit protection electromagnetic assembly. The electromagnetic coil pushes the moving iron core of the electromagnet to push the push plate of the push rod, pushing the push rod to slide to the other end. The push rod drives the moving piece push frame 6 to swing in the opposite direction. The upper swing arm of the moving piece push frame is released from the dead point state and pushes the protrusion 701 of the moving piece through the hook 602, causing the moving piece to reverse. When the push rod slides to the position, the magnet assembly 3 forms a magnetic attraction and retention. The moving piece push frame swings in the opposite direction to the position. The moving piece swings until the moving contact separates from the stationary contact of the stationary piece. The stationary piece and the second lead piece are disconnected, thus realizing short-circuit protection.

[0041] The above description is intended to illustrate the technical means of the present invention and is not intended to limit the scope of the invention. Any obvious improvements or substitutions made to the present invention by those skilled in the art based on existing common knowledge also fall within the protection scope of the claims of the present invention.

Claims

1. A magnetic latching relay, comprising a base (1), an electromagnetic coil assembly (2) fixed to the base, a magnet assembly (3) driven to rotate by changes in the magnetic poles of the electromagnetic coil assembly, a push rod (4) driven by the rotation of the magnet assembly and reciprocating within the base, and a stationary plate (9) and a first lead plate (13) fixedly provided on the base; characterized in that... The stationary plate (9) has a stationary contact (10) at its inner end. The base (1) has a movable plate (7) with a swing limit setting. The movable plate and the first lead-out plate (13) are electrically connected by a flexible wire (14). One end of the movable plate has a movable contact (8) that abuts against the stationary contact when it swings to the correct position. One side of the movable plate has a movable plate pusher (6) that swings relative to the base. The movable plate pusher has an upper swing arm (601), a hook (602), and a lower swing arm (603). The lower swing arm is linked with the push rod in the base and slides back and forth with the push rod. When the moving plate pusher is in a reciprocating swing position, when the moving plate pusher is swung to one side limit end, the end of the upper swing arm abuts against one side of the moving plate to restrict the swing of the moving plate, keeping the moving contact of the moving plate and the stationary contact of the stationary plate in abutting and guiding position, and the moving plate is provided with a protrusion (701) extending into the hook of the moving plate pusher on one side; when the moving plate pusher is swung to the other side limit end, the end of the upper swing arm of the moving plate pusher is released from abutting against one side of the moving plate, and the hook of the moving plate pusher pushes the protrusion to drive the moving plate to swing in the opposite direction to the position, that is, the moving contact of the moving plate and the stationary contact of the stationary plate are separated.

2. The magnetic latching relay according to claim 1, characterized in that... A short-circuit protection electromagnetic component is fixedly provided in the base (1) near the push rod (4). The short-circuit protection electromagnetic component includes an electromagnetic coil (17) and an electromagnet (16). One end of the electromagnetic coil is connected to the inner end of the first lead-out piece (13), and the other end of the electromagnetic coil is connected to the second lead-out piece (18) fixed relative to the base (1). A push plate (401) is integrated on one side of the push rod. The push plate extends into the space where the short-circuit protection electromagnetic component is located in the base (1), and the end face of the push plate is opposite to the moving iron core (1601) of the electromagnet. When the push rod slides to the point where the moving contact (8) of the moving piece (7) is connected to the point where the stationary contact (10) of the stationary piece (9) is connected, the end face of the push plate of the push rod falls into the pushing stroke range of the moving iron core of the electromagnet. When the moving iron core of the electromagnet changes from the reset state to the pushing state, it pushes the push plate to drive the push rod to slide until the moving contact of the moving piece and the stationary contact of the stationary piece are separated.

3. The magnetic latching relay according to claim 1, characterized in that... The base (1) is equipped with auxiliary springs (5) at both ends corresponding to the sliding direction of the push rod (4). When the magnet assembly (3) swings and pushes the push rod to slide into place, the push rod compresses the auxiliary spring at the corresponding end.

4. The magnetic latching relay according to claim 1, characterized in that... The upper swing arm (601) of the moving plate pusher (6) has a notch (6012) in the middle and swing arms (6011) on both sides. The moving plate (7) has a waist (703) in the middle that mates with the notch, and guide slopes (704) on both sides of the waist that mate with the swing arms. When the moving plate pusher rotates to the point where the moving contact (8) of the moving plate and the stationary contact (10) of the stationary plate (9) are in close contact, the upper swing arm only has its swing arm end against one side of the moving plate. When the moving plate pusher rotates to the point where the moving contact of the moving plate and the stationary contact of the stationary plate are separated, the notch of the upper swing arm mates with the waist of the moving plate, and the swing arms on both sides of the notch of the upper swing arm and the guide slopes on both sides of the waist of the moving plate form a guide engagement.

5. The magnetic latching relay according to claim 1, characterized in that... The stationary plate (9) has an integrally connected elastic conductive part at one end that extends into the base (1). The stationary plate and the elastic conductive part are connected in a U-shape. The elastic conductive part includes a conductive spring (11) and a shunt plate (12) with an arc-shaped cavity in the middle. One end of the conductive spring and the shunt plate is fixed to the end of the stationary plate. The other end of the conductive spring and the shunt plate is simultaneously fixed to the stationary contact (10). There is a gap between the stationary contact and the stationary plate inside the base. When the stationary plate is energized, the magnetic field formed by it forms a thrust on the elastic conductive part. The base limits the swing direction of the elastic conductive part under the action of the thrust.

6. The magnetic latching relay according to claim 1, characterized in that... Arc-extinguishing plates (15) are arranged within the base (1) within the travel length of the moving contact (8) of the moving plate (7) and the stationary contact (10) of the stationary plate (9).

7. The magnetic latching relay according to claim 1, characterized in that... The moving piece (7) has a plate shaft (702) on both sides at one end, and the base (1) has a double fan-shaped groove (101) that cooperates with the plate shaft to limit rotation.

8. The magnetic latching relay according to claim 1, characterized in that... The magnet assembly (3) is integrated with a swing arm (301), the end of which is engaged with an opening at one end of the push rod (4), and the end of the lower swing arm (603) of the moving plate push frame (6) is engaged with an opening at the other end of the push rod.

9. A method for operating a magnetic latching relay as described in claim 1, characterized in that... The working method of the magnetic latching relay is as follows: In the initial state, the moving contact (8) of the moving piece (7) and the stationary contact (10) of the stationary piece (9) are separated and in the correct position; at this time, the electromagnetic coil assembly (2) is energized and drives the magnet assembly (3) to rotate. The magnet assembly pushes the push rod (4) to slide to one end. The push rod drives the moving piece push frame (6) to rotate. The upper swing arm (601) of the moving piece push frame pushes the moving piece to form a swing. When the push rod slides to the limit end, the magnet assembly forms a magnetic attraction and retains the moving piece. The moving piece push frame rotates to the correct position, and the moving contact of the moving piece abuts against the stationary contact of the stationary piece to form a conductive connection. At the same time, a dead point is formed at the point where the upper swing arm of the moving piece push frame abuts against the moving piece to restrict the reversal of the moving piece, keeping the moving contact of the moving piece in the correct position. The stationary contact of the stationary piece is connected to the stationary piece, and the stationary piece and the first lead-out piece (13) are connected through the moving piece and the flexible wire (14). When it is necessary to cut off the connection between the stationary piece and the lead-out piece, the electromagnetic coil assembly is controlled to be energized in reverse, which drives the magnet assembly to swing in reverse. The magnet assembly pushes the push rod to slide to the other end. The push rod drives the moving piece push frame to swing in reverse. The upper swing arm of the moving piece push frame releases the dead point state and pushes the protrusion (701) of the moving piece through the hook (602), which drives the moving piece to reverse. When the push rod slides to the position, the magnet assembly forms a magnetic attraction and holds the moving piece. The moving piece push frame swings in reverse to the position. The moving piece swings to the point where the moving contact separates from the stationary contact of the stationary piece, thus realizing the disconnection between the stationary piece and the first lead-out piece.

10. A short-circuit protection method for a magnetic latching relay as described in claim 2, characterized in that... The short-circuit protection method of the magnetic latching relay is as follows: In the initial state, the moving contact (8) of the moving piece (7) and the stationary contact (10) of the stationary piece (9) are separated and in position. At this time, the electromagnetic coil assembly (2) is energized and drives the magnet assembly (3) to rotate. The magnet assembly pushes the push rod (4) to slide to one end. The push rod drives the moving piece push frame (6) to rotate. The upper swing arm (601) of the moving piece push frame pushes the moving piece to form a swing. When the push rod slides to the limit end, the magnet assembly forms a magnetic attraction and retains it. The moving piece push frame rotates to position, and the moving contact of the moving piece and the stationary contact of the stationary piece abut together to form a conductive connection. The end face of the push plate (401) of the push rod is close to the moving iron core (1601) of the electromagnet (16) of the short-circuit protection electromagnetic assembly. At this time, a dead point is formed at the point where the upper swing arm of the moving piece push frame abuts the moving piece to restrict the reversal of the moving piece, keeping the moving contact of the moving piece and the stationary contact of the stationary piece in a fixed position. The stationary contact of the plate is connected, and the stationary plate and the second lead plate (18) are connected through the moving plate and the flexible wire (14). In this state, when the current between the second lead plate and the stationary plate is greater than the set maximum value, the current passes through the electromagnetic coil (17) of the short-circuit protection electromagnetic component. The electromagnetic coil pushes the moving iron core of the electromagnet to push the push plate of the push rod, pushing the push rod to slide to the other end. The push rod drives the moving plate push frame to swing in the opposite direction. The upper swing arm of the moving plate push frame releases the dead point state and pushes the protrusion (701) of the moving plate through the hook (602), driving the moving plate to reverse. When the push rod slides to the position, the magnet assembly forms a magnetic attraction and holds. The moving plate push frame swings in the opposite direction to the position. The moving plate swings until the moving contact separates from the stationary contact of the stationary plate. The stationary plate and the second lead plate are disconnected. The moving iron core of the electromagnet resets instantly after the electromagnetic coil is de-energized. The short-circuit protection process is completed.

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