A solenoid driven magnetic actuator

Abstract

The application relates to a magnetic drive mechanism for an electrical switch, in particular to a solenoid coil driven magnetic drive mechanism. The solenoid coil driven magnetic drive mechanism comprises a moving permanent magnet assembly, a static iron, a guide rod, a solenoid coil and an outer cover; the top surface of the solenoid coil is flush with the top surface of the static iron, or the static iron is recessed inward along the top surface of the solenoid coil and accommodated in the solenoid coil; in the open state, the lower surface of the moving permanent magnet assembly is flush with the bottom surface of the solenoid coil, or the moving permanent magnet assembly is recessed inward along the bottom surface of the solenoid coil and accommodated in the solenoid coil. The beneficial effect is that the moving permanent magnet assembly is moved towards the static iron and interacts with the permanent magnet assembly when the solenoid coil is electrified, and the high-coercivity permanent magnet is recessed in the soft magnetic shell, the solenoid coil completely wraps the static iron and the permanent magnet assembly, the high-coercivity permanent magnet and the axial distribution of the magnetic force line of the static iron, so that the closing and opening efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of magnetic actuators for electrical switches, and more particularly to a solenoid coil driven magnetic actuator. Background Technology

[0002] The permanent magnet operating mechanism uses the interaction between the magnetic field generated by the permanent magnet and the magnetic field generated by the electromagnetic coil to realize the opening and closing operation. When the switch needs to be opened or closed, the polarity of the coil is changed to drive the opening or closing by using the principle of magnetic attraction or repulsion.

[0003] Existing circuit breaker operating mechanisms mainly include spring mechanisms, traditional permanent magnet mechanisms (FPMA), and magnetic control mechanisms. Spring mechanisms rely on mechanical latches and linkage transmission, resulting in complex structures, short lifespans, and slow response. Traditional permanent magnet mechanisms typically fix permanent magnets (which often suffer from severe magnetic leakage) to stationary components, while the moving parts are soft magnetic moving irons, leading to high costs and low closing efficiency.

[0004] In view of this, this application proposes a solenoid coil driven magnetic mechanism. Summary of the Invention

[0005] The purpose of this application is to address the technical problems pointed out in the background art by proposing a solenoid coil driven magnetic mechanism.

[0006] The technical solution of this application is: a solenoid coil driven magnetic mechanism, comprising: a moving permanent magnet assembly, a stationary iron, a guide rod, a solenoid coil, and an outer casing; The solenoid coil is fixedly installed in the outer cover, the top of the stationary iron is fixedly connected to the inner wall of the top of the outer cover, and the side wall of the stationary iron is attached to the inner side of the solenoid coil. The moving permanent magnet assembly is slidably connected to the inner side of the solenoid coil. The guide rod is fixedly connected to the moving permanent magnet assembly, and the guide rod is slidably connected to the stationary iron and the outer cover; The top surface of the solenoid coil is flush with the top surface of the stationary iron, or the stationary iron is recessed inward along the top surface of the solenoid coil and housed in the solenoid coil; in the open state, the lower surface of the permanent magnet component of the moving permanent magnet assembly is flush with the bottom surface of the solenoid coil, or the moving permanent magnet component is recessed inward along the bottom surface of the solenoid coil and housed in the solenoid coil. When the solenoid coil is energized, the moving permanent magnet component moves toward or away from the static iron due to the force exerted by the stationary iron and the force exerted by the solenoid coil.

[0007] In an optional embodiment, the force between the solenoid coil and the moving permanent magnet component is a Lorentz force.

[0008] In an optional embodiment, the motion permanent magnet assembly includes a soft magnetic permeable shell and a high coercivity permanent magnet. The upper end of the soft magnetic permeable shell has a groove, and the high coercivity permanent magnet is recessed in the groove.

[0009] In an optional embodiment, the magnetic field lines of the high coercivity permanent magnet are axial magnetic field lines; the magnetic field lines of the magnetized static iron are axial magnetic field lines.

[0010] In an optional embodiment, the inner ring end face of the stationary iron is disposed opposite to the upper end face of the high coercivity permanent magnet, and the outer ring end face of the stationary iron is disposed opposite to the annular upper end face of the magnetic shell. The outer diameter of the high coercivity permanent magnet is smaller than the inner diameter of the outer ring end face.

[0011] In an optional embodiment, When a positive current pulse is applied to the solenoid coil, the magnetic poles of the inner ring end face and the upper end face of the permanent magnet are opposite in direction, the outer ring end face interacts with the upper end face of the magnetic shell ring, and the magnetic poles of the upper end face of the permanent magnet and the upper end face of the magnetic shell ring are opposite in direction.

[0012] In an optional embodiment, When the solenoid coil is subjected to a reverse current pulse, the magnetic pole direction of the inner ring end face is the same as that of the upper end face of the permanent magnet, the outer ring end face interacts with the upper end face of the magnetic shell ring, and the magnetic pole direction of the upper end face of the permanent magnet is opposite to that of the upper end face of the magnetic shell ring.

[0013] In an optional embodiment, a unipolar switching drive circuit is also included. The unipolar switching drive circuit is mounted on the outer casing and applies positive or reverse current pulses to the solenoid coil.

[0014] In an optional embodiment, the annular outer wall of the high coercivity permanent magnet is fixedly wrapped with epoxy resin, and the epoxy resin is recessed in the groove.

[0015] In an optional embodiment, the outer cover, the stationary iron, and the center of the moving permanent magnet assembly are all provided with a concentric through groove, and the guide rod is connected through the concentric through groove; the center of the stationary iron near the end of the moving permanent magnet assembly is provided with an inner groove; A gate-opening spring is sleeved on the guide rod, and the gate-opening spring is located between the moving permanent magnet assembly and the stationary iron; one end of the gate-opening spring is fixedly connected to the inner wall of the inner groove, and the other end of the gate-opening spring is fixedly connected to the high coercivity permanent magnet. The upper end of the guide rod is connected to the switch spindle or the arc-extinguishing chamber pull rod.

[0016] Compared with the prior art, this application has the following beneficial technical effects: This application improves closing and opening efficiency and reduces the number of coil turns required by utilizing the interaction between the permanent magnet component moving towards the stationary iron and the solenoid coil being energized, the high coercivity permanent magnet being recessed in the soft magnetic shell, the solenoid coil completely enclosing the stationary iron and the permanent magnet component, and the axial distribution of the magnetic lines of force between the high coercivity permanent magnet and the stationary iron. It is particularly noteworthy that the N52SH grade high coercivity neodymium iron boron permanent magnet and the soft magnetic shell made of A3 steel have highly compatible magnetic properties, resulting in good magnetic circuit continuity and effectively reducing the magnetic reluctance of the magnetic circuit itself. Simultaneously, relying on the directional magnetic focusing design of the pot-shaped magnetic structure (groove structure), the leakage magnetic rate is reduced from the source. Compared to traditional ordinary steel magnetic circuits, this structure reduces the leakage magnetic rate by more than 30%, and increases the magnetic energy utilization rate from less than 30% to more than 90%, further improving the closing efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view of a solenoid coil-driven magnetic mechanism in a static, unpowered state. Figure 2 This is a cross-sectional schematic diagram of the instantaneous state (including magnetic lines of force) of a solenoid coil driven magnetic mechanism at the moment of energization; Figure 3 This is a schematic cross-sectional view of a solenoid coil driven magnetic mechanism in the closed state. Figure 4 This is a schematic cross-sectional view of a solenoid coil driven magnetic mechanism in the closed state (including magnetic lines of force); Figure 5 This is a schematic diagram of the moving permanent magnet component in this application; Figure 6 This is a schematic diagram of the static iron structure in this application; Reference numerals: 1. Motion permanent magnet assembly; 11. Soft magnetic conductive shell; 111. Annular upper end face of the magnetic shell; 112. Groove; 113. Lower surface of the permanent magnet assembly; 12. High coercivity permanent magnet; 121. Upper end face of the permanent magnet; 13. Epoxy resin; 2. Static iron; 21. Outer ring of the static iron; 211. End face of the outer ring; 22. Inner ring of the static iron; 221. End face of the inner ring; 23. Top surface of the static iron; 3. Guide rod; 4. Opening spring; 5. Solenoid coil; 51. Top surface; 52. Bottom surface; 6. Fastener. Detailed Implementation

[0018] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0020] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0023] like Figures 1-6 As shown, the solenoid coil driven magnetic mechanism proposed in this application is characterized by comprising: a moving permanent magnet assembly 1, a stationary iron 2, a guide rod 3, a solenoid coil 5, and an outer cover; The solenoid coil 5 is fixedly installed in the outer cover, the top of the stationary iron 2 is fixedly connected to the inner wall of the top of the outer cover, and the side wall of the stationary iron 2 is attached to the inner side of the solenoid coil 5. The moving permanent magnet assembly 1 is slidably connected to the inner side of the solenoid coil 5. The guide rod 3 is fixedly connected to the motion permanent magnet assembly 1, and the guide rod 3 is slidably connected to the stationary iron 2 and the outer cover; The top surface 51 of the solenoid coil 5 is flush with the top surface 23 of the stationary iron 2, or the stationary iron 2 is recessed inward along the top surface 51 of the solenoid coil 5 and housed in the solenoid coil 5; in the open state, the lower surface 113 of the permanent magnet component 1 is flush with the bottom surface 52 of the solenoid coil 5, or the permanent magnet component 1 is recessed inward along the bottom surface 52 of the solenoid coil 5 and housed in the solenoid coil 5. When the solenoid coil 5 is energized, the moving permanent magnet assembly 1 moves towards or away from the stationary iron 2 due to the forces exerted by the stationary iron 2 and the solenoid coil 5. The force between the solenoid coil 5 and the moving permanent magnet assembly 1 is the Lorentz force.

[0024] See appendix Figure 1-4In this embodiment, during the closing process, the permanent magnet component 1 moves towards the stationary iron 2. Since the mass of the permanent magnet component 1 is less than that of the stationary iron 2, when the same current is applied to magnetize the stationary iron 2 with unchanged coil parameters, the magnetic force generated by the stationary iron 2 and the attractive force between it and the permanent magnet component 1 remain unchanged. This results in the permanent magnet component 1 moving towards the soft magnetic yoke 22 at a greater speed than the stationary iron 2 moving towards the permanent magnet component 1 under the same conditions. Moreover, to maintain magnetic field stability, the stationary iron 2 needs to move along with the solenoid coil 5 when moving towards the permanent magnet component 1, further increasing the mass of the moving parts and causing a further reduction in closing efficiency. If the magnetic field is unstable, the closing efficiency will continue to decrease. Therefore, this embodiment proposes a closing scheme in which the permanent magnet component 1 moves closer to the stationary iron 2 to improve closing efficiency. If the positions of the permanent magnet component 1 and the stationary iron 2 in this embodiment are interchanged, i.e., the stationary iron 2 moves towards the permanent magnet component 1, not only will the aforementioned reduction in closing efficiency occur, but also, due to insufficient coil windings, insufficient attraction will prevent the stationary iron 2 from moving towards the permanent magnet component 1. The use of permanent magnet component 1 to move toward stationary iron 2 is also one of the core contributions of this application. In the prior art, the volume of stationary iron 2 is generally reduced, or the mass (volume) of the auxiliary permanent magnet or the fixed permanent magnet is increased simultaneously to ensure sufficient attraction to drive stationary iron 2, such as Chinese patent CN108257800A.

[0025] By using the closing method where the permanent magnet component 1 moves toward the stationary iron 2, the attraction between the permanent magnet component 1 and the stationary iron 2 can be reduced, which can also reduce the number of coil bundles.

[0026] It is particularly noteworthy that, in this embodiment, whether in the closed or open state, the solenoid coil 5 completely encloses the stationary iron 2 and the moving permanent magnet component 1. As one of the main inventive points of this invention, especially when in the open state, the lower surface 113 of the permanent magnet component 1 is flush with the bottom surface 52 of the solenoid coil 5, or the moving permanent magnet component 1 is recessed inward along the bottom surface 52 of the solenoid coil 5 and housed in the solenoid coil 5. This not only improves the lateral magnetization effect of the solenoid coil 5 on the stationary iron 2 when energized, especially the magnetization effect on the inner ring 22 of the stationary iron, but also allows the Lorentz force generated when the solenoid coil 5 is energized to drive the moving permanent magnet component 1 toward the stationary iron 2. The Lorentz force and the attraction between the stationary iron 2 and the moving permanent magnet component 1 form a resultant force, further improving the closing efficiency.

[0027] Furthermore, the motion permanent magnet assembly 1 includes a soft magnetic permeable shell 11 and a high coercivity permanent magnet 12. The upper end of the soft magnetic permeable shell 11 has a groove 112, and the high coercivity permanent magnet 12 is recessed in the groove. The soft magnetic permeable shell 11 can not only be magnetized to make full use of the magnetic lines of force around the high coercivity permanent magnet 12, but also cover the high coercivity permanent magnet 12 to reduce magnetic leakage. It should be noted that the epoxy resin 13 is fixedly connected to the outer wall of the high coercivity permanent magnet 12, and the epoxy resin 3 is recessed in the groove, while the high coercivity permanent magnet 12 is recessed in the groove (the height of the upper end face 121 of the permanent magnet 12 is lower than the upper end face 111 of the magnetic shell ring), which further reduces magnetic leakage and ensures the magnetic stability of the high coercivity permanent magnet 12. In particular, when closing the circuit, the upper end face 111 of the magnetic shell ring contacts the stationary iron 2, while the high coercivity permanent magnet 12 does not contact the stationary iron 2. As one of the main inventive points of this invention, it ensures that the high coercivity permanent magnet 12 does not contact the stationary iron 2 when the closing speed is increased, avoids the impact damage of the high coercivity permanent magnet 12, and extends the service life of the magnetic mechanism.

[0028] In a preferred embodiment, the high coercivity permanent magnet 12 uses N52SH grade high coercivity neodymium iron boron permanent magnet as the core magnet, and the soft magnetic permeable shell 11 is made of A3 steel. The two are vacuum-sealed with epoxy resin. The magnetic properties of the N52SH grade high coercivity neodymium iron boron permanent magnet and the A3 steel soft magnetic permeable shell are highly matched, resulting in good magnetic circuit continuity and effectively reducing the magnetic resistance of the magnetic circuit body. At the same time, relying on the directional magnetic focusing design of the pot magnetic structure (groove structure), the leakage magnetic rate is reduced from the root. Compared with Compared to traditional ordinary steel magnetic circuits, this structure reduces magnetic leakage rate by more than 30% and increases magnetic energy utilization from less than 30% to more than 90%. It should be noted that the permeability of the soft magnetic shell made of A3 steel is much higher than that of air. As a low magnetic reluctance yoke, it forms a closed magnetic circuit with the permanent magnet, which gathers all the leakage magnetic energy that originally diverged freely from the side and back of the magnet to the front working contact surface, greatly reducing the leakage coefficient. This fundamentally solves the industry pain point of low magnetic energy utilization of traditional bare magnets and can increase magnetic energy utilization to more than 90%.

[0029] In this embodiment, the magnetic field lines of the high coercivity permanent magnet 12 are axial magnetic field lines; the magnetic field lines of the magnetized iron 2 are also axial magnetic field lines. The magnetic field lines of both the high coercivity permanent magnet 12 and the iron 2 are axial, which can maximize the attraction and repulsion between the two (permanent magnet component 1 and iron 2) compared to other magnetic field line arrangements.

[0030] It should also be noted that the inner ring end face 221 of the stationary iron 2 is positioned opposite to the upper end face 121 of the high coercivity permanent magnet 12, and the outer ring end face 211 of the stationary iron 2 is positioned opposite to the upper end face 111 of the magnetic shell ring; the outer diameter of the high coercivity permanent magnet 12 is smaller than the inner diameter of the outer ring end face 211. When a positive current pulse is applied to the solenoid coil 5, the magnetic pole directions of the inner ring end face 221 and the upper end face 121 of the permanent magnet are opposite, the outer ring end face 211 interacts with the upper end face 111 of the magnetic shell ring, and the magnetic pole directions of the upper end face 121 of the permanent magnet and the upper end face 111 of the magnetic shell ring ring are opposite. When a reverse current pulse is applied to the solenoid coil 5, the magnetic poles of the inner ring end face 221 and the upper end face 121 of the permanent magnet are in the same direction, while the outer ring end face 211 interacts with the annular upper end face 111 of the magnetic shell, and the magnetic poles of the upper end face 121 of the permanent magnet and the annular upper end face 111 of the magnetic shell are in opposite directions. This structural arrangement ensures rapid attraction between the upper end face 121 of the permanent magnet and the inner ring end face 221 of the stationary iron 2, thus improving the closing efficiency through the interaction of the concentrated magnetic field lines.

[0031] The opening process is the reverse of the closing process described above, and will not be repeated here. This magnetic structure also includes a unipolar switching drive circuit, which is mounted on the outer casing. The unipolar switching drive circuit applies forward or reverse current pulses to the solenoid coil 5. A concentric slot is formed at the center of the outer casing, the stationary iron 2, and the moving permanent magnet assembly 1, and a guide rod 3 passes through and is connected within the concentric slot. An inner groove is formed at the center of the stationary iron 2 near the moving permanent magnet assembly 1. A closing spring 4 is fitted onto the guide rod 3, located between the moving permanent magnet assembly 1 and the stationary iron 2. One end of the closing spring 4 is fixedly connected to the inner wall of the inner groove, and the other end is fixedly connected to the high coercivity permanent magnet 12. The upper end of the guide rod 3 is connected to the switch spindle or the arc-extinguishing chamber pull rod.

[0032] The following is a brief summary of the working process of this application: When the circuit is closed, the current in the solenoid coil 5 causes the stationary iron 2 to attract the moving permanent magnet component 1, which overcomes the resistance of the opening spring 4 and the contact pressure spring to complete the closing action of the switch.

[0033] When the closed state is maintained: the moving permanent magnet component 1 and the stationary iron 2 share the magnetic circuit and maintain the closed state. When the circuit is opened, a reverse current is passed through the solenoid coil 5. Since it shares a magnetic circuit with the moving permanent magnet component 1, the generated magnetomotive force breaks the holding of the high coercivity permanent magnet 12, and under the combined action of the opening spring 4 and the contact spring, separation occurs, thus opening the circuit.

[0034] When the circuit breaker is in the open position, the upward attraction of the moving permanent magnet component 1 is less than the preload of the opening spring 4, thus maintaining balance and stabilizing in the open position.

[0035] The above specific embodiments are merely preferred embodiments of this application. Based on the technical solutions of this application and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments. The above specific embodiments are merely explanations of this application and are not limitations on this application.

Claims

1. A solenoid coil driven magnetic mechanism, characterized in that, include: Motion permanent magnet assembly (1), stationary iron (2), guide rod (3), solenoid coil (5) and outer cover; The solenoid coil (5) is fixedly installed in the outer cover, the top of the stationary iron (2) is fixedly connected to the top inner wall of the outer cover, and the side wall of the stationary iron (2) is attached to the inner side of the solenoid coil (5). The motion permanent magnet assembly (1) is slidably connected to the inner side of the solenoid coil (5). The guide rod (3) is fixedly connected to the motion permanent magnet assembly (1), and the guide rod (3) is slidably connected to the stationary iron (2) and the outer cover; The top surface (51) of the solenoid coil (5) is flush with the top surface (23) of the stationary iron (2), or the stationary iron (2) is recessed inward along the top surface (51) of the solenoid coil (5) and housed in the solenoid coil (5); in the open state, the lower surface (113) of the permanent magnet component (1) is flush with the bottom surface (52) of the solenoid coil (5), or the permanent magnet component (1) is recessed inward along the bottom surface (52) of the solenoid coil (5) and housed in the solenoid coil (5); When the solenoid coil (5) is energized, the moving permanent magnet component (1) moves toward or away from the static iron (2) under the force of the stationary iron (2) and the force of the solenoid coil (5).

2. The solenoid coil driven magnetic mechanism according to claim 1, characterized in that, The force between the solenoid coil (5) and the moving permanent magnet component (1) is the Lorentz force.

3. The solenoid coil driven magnetic mechanism according to claim 1, characterized in that, The motion permanent magnet assembly (1) includes a soft magnetic permeable shell (11) and a high coercivity permanent magnet (12). The upper end of the soft magnetic permeable shell (11) is provided with a groove (112), and the high coercivity permanent magnet (12) is recessed in the groove (112).

4. The solenoid coil driven magnetic mechanism according to claim 3, characterized in that, The magnetic field lines of the high coercivity permanent magnet (12) are axial magnetic field lines; the magnetic field lines of the magnetized static iron (2) are axial magnetic field lines.

5. The solenoid coil driven magnetic mechanism according to claim 4, characterized in that, The inner ring end face (221) of the static iron (2) is arranged opposite to the upper end face (121) of the high coercivity permanent magnet (12), and the outer ring end face (211) of the static iron (2) is arranged opposite to the upper end face (111) of the magnetic shell ring. The outer diameter of the high coercivity permanent magnet (12) is smaller than the inner diameter of the outer ring end face (211).

6. The solenoid coil driven magnetic mechanism according to claim 5, characterized in that, When the solenoid coil (5) is energized with a positive current pulse, the magnetic pole directions of the inner ring end face (221) and the upper end face (121) of the permanent magnet are opposite, the outer ring end face (211) interacts with the upper end face (111) of the magnetic shell, and the magnetic pole directions of the upper end face (121) of the permanent magnet and the upper end face (111) of the magnetic shell are opposite.

7. A solenoid coil driven magnetic mechanism according to claim 6, characterized in that, When the solenoid coil (5) is subjected to a reverse current pulse, the magnetic pole direction of the inner ring end face (221) is the same as that of the upper end face (121) of the permanent magnet, the outer ring end face (211) interacts with the upper end face (111) of the magnetic shell ring, and the magnetic pole direction of the upper end face (121) of the permanent magnet ring is opposite to that of the upper end face (111) of the magnetic shell ring.

8. The solenoid coil driven magnetic mechanism according to claim 7, characterized in that, It also includes a unipolar switching drive circuit, which is mounted on the outer casing and applies positive or reverse current pulses to the solenoid coil (5) through the unipolar switching drive circuit.

9. A solenoid coil driven magnetic mechanism according to claim 3, characterized in that, The annular outer wall of the high coercivity permanent magnet (12) is fixedly wrapped with epoxy resin (13), and the epoxy resin (13) is recessed in the groove (112).

10. A solenoid coil driven magnetic mechanism according to claim 3, characterized in that, The outer cover, the stationary iron (2), and the center of the moving permanent magnet assembly (1) are all provided with a concentric through groove, and the guide rod (3) is connected through the concentric through groove; the stationary iron (2) is provided with an inner groove at the center of one end near the moving permanent magnet assembly (1); A gate-opening spring (4) is sleeved on the guide rod (3). The gate-opening spring (4) is located between the moving permanent magnet assembly (1) and the stationary iron (2). One end of the gate-opening spring (4) is fixedly connected to the inner wall of the inner groove, and the other end of the gate-opening spring (4) is fixedly connected to the high coercivity permanent magnet (12). The upper end of the guide rod (3) is connected to the switch spindle or the arc-extinguishing chamber pull rod.

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