Repulsive force mechanism buffer device based on magnetorheological fluid

Abstract

The invention relates to the technical field of repulsive force switches, and particularly discloses a repulsive force mechanism buffer device based on magnetorheological fluid, which comprises a piston type magnetorheological damper, a magnet exciting coil, a displacement sensor and a control system, the magnet exciting coil is wound on the outer surface of a piston assembly of the piston type magnetorheological damper; the piston type magnetorheological damper adjusts the rheological property of magnetorheological fluid through a magnetic field generated by the magnet exciting coil. The displacement sensor is used for detecting the movement of a repulsive force disc in the repulsive force mechanism; the excitation coil and the displacement sensor are electrically connected with the control system; the control system regulates the power supply current intensity of the magnet exciting coil at least according to detection information of the displacement sensor; according to the repulsive force mechanism buffering device based on the magnetorheological fluid, the magnet exciting coil is used for generating a magnetic field, discharging control is conducted on the coil through the capacitor, and therefore real-time adjustment of the magnetorheological fluid damper is achieved, impact and vibration of the repulsive force mechanism are effectively reduced, the operation stability of equipment is improved, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of repulsive switches, and particularly to a buffer device for a repulsive mechanism based on magnetorheological fluid. Background Art

[0002] When a power switch performs a fast closing operation, contact bounce phenomenon will occur, accompanied by mechanical vibration. This may cause electrical breakdown between contacts, easily resulting in contact welding or wear, thus affecting the service life of the circuit breaker and reducing the operation reliability and stability. Therefore, the buffering performance of the high-speed buffer device plays an important role in the design of the opening driving force of the repulsive mechanism, and its buffering ability restricts the selection of the opening driving force.

[0003] The buffer devices for reducing contact bounce mainly include three types: rubber type, spring type and hydraulic type. The rubber type buffer device is prone to aging and has poor high-temperature resistance, and its adaptability to large-load applications is also insufficient; the spring type buffer device has problems such as strong rigidity, easy fatigue or fracture, and complex installation and debugging; the hydraulic type buffer device also has disadvantages such as oil leakage, large volume and high maintenance requirements. [[ID=*12]] Summary of the Invention

[0004] The purpose of the present invention is to provide a buffer device for a repulsive mechanism based on magnetorheological fluid, which can effectively reduce the impact and vibration of the repulsive mechanism by adjusting the damping characteristics of the magnetorheological fluid, and improve the operation stability and service life of the equipment.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A buffer device for a repulsive mechanism based on magnetorheological fluid, comprising: a piston-type magnetorheological damper, an excitation coil, a displacement sensor and a control system.

[0007] The excitation coil is wound around the outer surface of the piston assembly of the piston-type magnetorheological damper.

[0008] The piston-type magnetorheological damper adjusts the rheological characteristics of the magnetorheological fluid through the magnetic field generated by the excitation coil to change the damping force.

[0009] The displacement sensor is used to detect the movement of the repulsive disk in the repulsive mechanism.

[0010] Both the excitation coil and the displacement sensor are electrically connected to the control system.

[0011] The control system adjusts at least the supply current intensity of the excitation coil according to the detection information of the displacement sensor.

[0012] In the buffer device for a repulsive mechanism based on magnetorheological fluid provided by at least one embodiment of the present disclosure, the piston-type magnetorheological damper includes: a cylinder block and a piston assembly.

[0013] Both ends of the cylinder block are provided with end covers, and a sealing cavity is formed between the cylinder block and the end covers.

[0014] The sealing cavity is filled with magnetorheological fluid.

[0015] The piston assembly includes a piston and a piston rod. The piston rod is movably connected to the end cover, and both ends of the piston rod are located outside the sealing cavity.

[0016] The pistons are all located in the sealing cavity, and the pistons are fixedly connected to the piston rod.

[0017] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, a sealing member is provided between the cylinder block and the end cover, and the cylinder block and the end cover are sealed by the sealing member.

[0018] A magnetic isolation gasket is provided between the sealing member and the cylinder block.

[0019] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, a channel is provided inside the piston rod, a lead wire is connected to the excitation coil, and the lead wire is led out of the sealing cavity through the channel and connected to the control system.

[0020] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, the excitation coil is a multi-layer closely wound excitation coil.

[0021] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, the control system includes: a controller, a current sensor, a charging power supply, a fast switching device, and an energy storage capacitor.

[0022] The energy storage capacitor is charged by the charging power supply, and after the energy storage capacitor stores energy, it discharges precisely to the excitation coil through the fast switching device.

[0023] The displacement sensor, the current sensor, and the fast switching device are all electrically connected to the controller, and the energy storage capacitor is electrically connected to the excitation coil.

[0024] The controller dynamically regulates the discharge current and time of the energy storage capacitor according to the detection information of the current sensor and the displacement sensor to control the magnetic field intensity generated by the excitation coil.

[0025] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, a liquid injection hole is provided on the side wall of the cylinder block, and the cylinder block is non-magnetic.

[0026] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, the exciting coil is wound around the piston or the piston rod.

[0027] In the repulsive force mechanism buffer device based on magnetorheological fluid provided by at least one embodiment of the present disclosure, a wire groove is provided in the middle of the piston, and the piston is arranged in an I shape.

[0028] The exciting coil is wound in the wire groove.

[0029] The beneficial effects of the present invention are as follows: By combining the magnetic field regulation mechanism of magnetorheological fluid and the exciting coil, the damping characteristics of the buffer device can be controlled in real time and accurately. It has a higher response speed, more accurate regulation ability and longer service life, can effectively improve the stability and reliability of the repulsive force mechanism of the power switch, and reduce the damage to the equipment caused by mechanical shock.

[0030] It can be widely applied to power switches, circuit breakers and other high-voltage electrical equipment that require a repulsive force mechanism buffer, especially suitable for power systems that require high stability and long life. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a component connection diagram of a repulsive force mechanism buffer device based on magnetorheological fluid of the present invention.

[0033] Figure 2 It is a schematic internal structure diagram of a piston-type magnetorheological damper.

[0034] Figure 3 It is a usage state diagram of a repulsive force mechanism buffer device based on magnetorheological fluid of the present invention.

[0035] In the figure:

[0036] 10. Piston-type magnetorheological damper; 11. Cylinder block; 12. Piston assembly; 111. End cover; 112. Sealing cavity; 121. Piston; 122. Piston rod; 113. Magnetic isolation gasket; 114. Seal;

[0037] 20. Exciting coil;

[0038] 30. Displacement sensor;

[0039] 40. Controller; 41. Current sensor; 42. Charging power supply; 43. Fast switching device; 44. Energy storage capacitor;

[0040] 50. Connecting rod; 51. Insulating pull rod; 52. Vacuum interrupter; 53. Repulsive disk; 54. Tripping coil; 55. Closing coil. Detailed implementation manners

[0041] Next, the technical solutions in the embodiments will be clearly and completely described with reference to the accompanying drawings in the embodiments. Obviously, the described embodiments are only a part of the embodiments, rather than all the embodiments.

[0042] As Figures 1 - 3 shown, this embodiment provides a buffer device for a repulsive mechanism based on magnetorheological fluid, including: a piston-type magnetorheological damper 10, an excitation coil 20, a displacement sensor 30, and a control system.

[0043] Specifically, the excitation coil 20 is wound around the outer surface of the piston assembly 12 of the piston-type magnetorheological damper 10. The piston-type magnetorheological damper 10 adjusts the rheological properties of the magnetorheological fluid through the magnetic field generated by the excitation coil 20, and thus changes the damping force.

[0044] Specifically, the displacement sensor 30 is used to detect the movement of the repulsive disk in the repulsive mechanism. Both the excitation coil 20 and the displacement sensor 30 are electrically connected to the control system.

[0045] Specifically, the control system regulates the supply current intensity of the excitation coil 20 according to the detection information of the displacement sensor 30.

[0046] Next, the structure of the piston-type magnetorheological damper will be further disclosed.

[0047] As Figure 2 shown, the piston-type magnetorheological damper 10 includes: a cylinder block 11 and a piston assembly 12.

[0048] Specifically, end caps 111 are provided at both ends of the cylinder block 11, and a sealed cavity 112 is formed between the cylinder block 11 and the end caps 111. A liquid injection hole is provided on the side wall of the cylinder block 11, and the cylinder block 11 is made of non-magnetic material.

[0049] Specifically, the sealed cavity 112 is filled with magnetorheological fluid (not shown). The magnetorheological fluid is in the shear gap between the piston assembly 12 and the cylinder block 11.

[0050] Specifically, the piston assembly 12 includes a piston 121 and a piston rod 122. The piston rod 122 is movably connected to the end cap 111, and both ends of the piston rod 122 are located outside the sealed cavity 112. The pistons 121 are all located in the sealed cavity 112, and the pistons 121 are all fixedly connected to the piston rod 122.

[0051] Specifically, a wire groove is provided in the middle of the piston 121, and the piston 121 is of an I-shaped configuration. The exciting coil 20 is wound in the wire groove.

[0052] Specifically, a seal 114 is provided between the cylinder block 11 and the end cover 111, and the cylinder block 11 and the end cover 111 are sealed by the seal 114. A magnetic isolation gasket 113 is provided between the seal 114 and the cylinder block 11.

[0053] Specifically, a channel is provided inside the piston rod 122. The exciting coil 20 is connected with a wire, and the wire is led out of the sealing cavity 112 through the channel and connected to the control system. The exciting coil 20 is sealed and insulated by epoxy resin.

[0054] Specifically, the exciting coil 20 is a multi-layer closely wound exciting coil 20.

[0055] The structure of the control system will be further disclosed below.

[0056] As Figure 1 shown, the control system includes a controller 40, a current sensor 41, a charging power supply 42, a fast switching device 43, and an energy storage capacitor 44. The control system realizes precise regulation of the magnetic field of the exciting coil through a capacitor energy storage and fast discharge mechanism, and completes functions of energy storage, discharge, feedback, and regulation.

[0057] Specifically, the energy storage capacitor 44 is charged by the charging power supply 42, and after the energy storage capacitor 44 stores energy, it realizes precise discharge to the exciting coil 20 through the fast switching device 43.

[0058] Specifically, the displacement sensor 30, the current sensor 41, and the fast switching device 43 are all electrically connected to the controller 40, and the energy storage capacitor 44 is electrically connected to the exciting coil 20.

[0059] Specifically, the controller 40 dynamically regulates the discharge current and time of the energy storage capacitor 44 according to the detection information of the current sensor 41 and the displacement sensor 30 to control the magnetic field strength generated by the exciting coil 20.

[0060] The viscosity change range of the magnetorheological fluid is controlled by changing the current magnitude of the exciting coil 20; the magnetic field strength is increased during high-intensity impacts to increase the damping force; the magnetic field strength is decreased during low-intensity vibrations to optimize the response speed and energy consumption.

[0061] In some unshown embodiments, the exciting coil is wound on the piston rod.

[0062] The working principle of the repulsive force mechanism buffer device based on magnetorheological fluid in the embodiment will be further described below in conjunction with the vacuum interrupter and the repulsive force mechanism.

[0063] As Figure 3As shown in the figure, in the working circuit of the repulsive force mechanism, U1 is the charging power supply, S1 is the charging switch, C1 is the energy storage capacitor, VT1 is the transistor in the closing control circuit, and VT2 is the transistor in the opening control circuit. The opening control circuit is connected in parallel with the closing control circuit and shares a set of energy storage capacitors. During pre-charging, the charging switch S1 is closed, and the charging power supply U1 charges the energy storage capacitor C1. After charging is completed, the charging switch S1 is disconnected. Under the action of the trigger signal, the energy storage capacitor C1 discharges the closing coil through the closing control circuit or discharges the opening coil through the opening control circuit.

[0064] When the fast repulsive force switch performs a closing operation, VT1 is triggered to conduct, and the energy storage capacitor C1 that has been pre-charged by the charging power supply U1 discharges. A current will pass through the closing coil 55 arranged below the repulsive force disc 53, generating an alternating magnetic field and inducing eddy currents with opposite directions on the repulsive force disc. Under the interaction of the alternating magnetic field and the magnetic field generated by the eddy currents, the repulsive force disc is pushed by the electromagnetic repulsive force, and then drives the connecting rod 50, the insulating pull rod 51, and the moving end conducting rod in the vacuum interrupter 52 to push the contact upward for closing movement.

[0065] When the fast repulsive force switch performs an opening operation, VT1 is turned off and VT2 is triggered to conduct, and the energy storage capacitor C1 that has been pre-charged by the charging power supply U1 discharges. At this time, a current will pass through the opening coil 54 arranged above the repulsive force disc 53, generating an alternating magnetic field and inducing eddy currents with opposite directions on the repulsive force disc 53. Under the interaction of the alternating magnetic field and the magnetic field generated by the eddy currents, the repulsive force disc 53 is pushed by the electromagnetic repulsive force, driving the connecting rod 50, the insulating pull rod 51, and the moving end conducting rod in the vacuum interrupter 52 to move downward to achieve contact opening.

[0066] When the repulsive force mechanism operates, the displacement sensor 30 detects the movement of the repulsive force disc 53. The controller 40 calculates the target value of the damping force required currently based on the preset damping force model, and then derives the target current intensity of the excitation coil through the magnetic field-current mapping relationship. At the same time, the energy storage capacitor 44 pre-charged to the set voltage releases electrical energy under the control of the fast switching device 43. The capacitor discharge current is precisely regulated by the drive circuit and then input into the excitation coil 20, and its pulse width and frequency are dynamically adjusted by the PWM signal output by the control unit.

[0067] When current flows through the excitation coil 20, a uniform axial magnetic field is generated, and the direction of the magnetic field is perpendicular to the flow direction of the magnetorheological fluid in the shear gap. The micro-nano magnetic particles in the magnetorheological fluid quickly align into a chain-like structure along the direction of the magnetic induction lines under the action of the magnetic field, resulting in a significant increase in the shear yield strength of the fluid, thereby generating a velocity-related viscous resistance during the movement of the piston 121. This resistance is transmitted to the outside through the piston rod 122 to achieve efficient dissipation of impact energy. During this process, the current sensor 41 continuously monitors the actual current value in the discharge circuit and feeds the data back to the controller 40, and the duty cycle of the PWM signal is corrected in a closed loop through the PID algorithm to ensure the dynamic matching of the magnetic field strength with the target value.

[0068] When the speed of the piston 121 gradually decreases due to the damping effect, the controller 40 synchronously reduces the intensity of the discharge current pulse to avoid mechanical hysteresis caused by over-damping. If the system detects an abnormal condition (such as current over-limit or temperature too high), the protection circuit immediately cuts off the conduction state of the fast switch device 43 and triggers an audible and visual alarm signal to prevent equipment damage.

[0069] In summary, the entire device realizes efficient buffering with millisecond-level response and adaptive load changes through the fast energy conversion mechanism of energy storage and discharge of the energy storage capacitor C2, combined with the real-time rheological property adjustment of the magnetorheological fluid. At the same time, it takes into account the lightweight structure and long-life design, and is suitable for industrial scenarios with strict requirements for dynamic stability such as high-voltage circuit breakers and power switches.

[0070] Although the embodiments of the present application have been shown and described above, the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of without creative labor should be covered within the protection scope of the present invention; unless otherwise clearly stated, any element, action or instruction used in this article should not be construed as critical or necessary.

Claims

1. A repulsive mechanism buffer device based on magnetorheological fluid, characterized in that, Comprising: A piston-type magnetorheological damper, an excitation coil, a displacement sensor, and a control system; The excitation coil is wound around the outer surface of the piston assembly of the piston-type magnetorheological damper; The piston-type magnetorheological damper adjusts the rheological properties of the magnetorheological fluid through the magnetic field generated by the excitation coil to change the damping force; The displacement sensor is used to detect the movement of the repulsive disk in the repulsive mechanism; Both the excitation coil and the displacement sensor are electrically connected to the control system; The control system adjusts at least the supply current intensity of the excitation coil according to the detection information of the displacement sensor.

2. The buffer device of a repulsive force mechanism based on magnetorheological fluid according to claim 1, characterized in that, The piston-type magnetorheological damper includes: A cylinder block and a piston assembly; End caps are provided at both ends of the cylinder block, and a sealed cavity is formed between the cylinder block and the end caps; The sealed cavity is filled with magnetorheological fluid; The piston assembly includes a piston and a piston rod, the piston rod is movably connected to the end cap, and both ends of the piston rod are located outside the sealed cavity; The pistons are all located in the sealed cavity, and the pistons are fixedly connected to the piston rod.

3. The buffer device of a repulsive force mechanism based on magnetorheological fluid according to claim 2, characterized in that, A seal is provided between the cylinder block and the end cap, and the cylinder block and the end cap are sealed by the seal; A magnetic isolation gasket is provided between the seal and the cylinder block.

4. The buffer device of a repulsive force mechanism based on magnetorheological fluid according to claim 2, wherein A channel is provided inside the piston rod, the excitation coil is connected with a wire, and the wire is led out of the sealed cavity through the channel and connected to the control system.

5. A buffer device for a repulsive mechanism based on magnetorheological fluid according to claim 1 or 2, characterized in that, The excitation coil is a multi-layer closely wound excitation coil.

6. The buffer device of a repulsive force mechanism based on magnetorheological fluid according to claim 1, characterized in that, The control system includes: A controller, a current sensor, a charging power supply, a fast switching device, and an energy storage capacitor; The energy storage capacitor is charged through the charging power supply, and after energy storage, the energy storage capacitor discharges precisely to the excitation coil through the fast switching device; The displacement sensor, the current sensor, and the fast switching device are all electrically connected to the controller, and the energy storage capacitor is electrically connected to the excitation coil; The controller dynamically adjusts the discharge current and time of the energy storage capacitor according to the detection information of the current sensor and the displacement sensor to control the magnetic field intensity generated by the excitation coil.

7. A buffer device for a repulsive force mechanism based on magnetorheological fluid according to claim 2, characterized in that, A liquid injection hole is provided on the side wall of the cylinder block, and the cylinder block is non-magnetic.

8. A buffer device for a repulsive force mechanism based on magnetorheological fluid according to claim 2, characterized in that, The excitation coil is wound around the piston or the piston rod.

9. The buffer device of a repulsive force mechanism based on magnetorheological fluid according to claim 2, characterized in that, A wire groove is provided in the middle of the piston, and the piston is arranged in an I shape; The excitation coil is wound in the wire groove.

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