Electromagnetic seismic mechanism

Abstract

The application discloses an electromagnetic anti-vibration mechanism, which comprises a movable magnetic core, a coil and a reverse current control module. The movable magnetic core is connected with a pulling mechanism and can move in the coil. When the pulling mechanism breaks the steel bar and generates an instantaneous impact force, the movable magnetic core moves, the coil cuts the magnetic induction lines and generates an instantaneous maximum current, the reverse current control module detects the current and can input a reverse current not less than the instantaneous maximum current to the coil in a very short time; the coil generates a reverse magnetic field which interacts with the magnetic field of the movable magnetic core to generate an upward electromagnetic repulsive force, actively counteracts the impact force, makes the movable magnetic core instantaneously decelerate or even stop, and realizes a sharp decrease of vibration amplitude; with the attenuation of the impact force, the reverse current value is gradually reduced by a power supply adjusting unit to avoid the excessive electromagnetic force from causing reverse bouncing of the equipment.

Description

Technical Field

[0001] This application relates to the field of vibration resistance technology for universal testing machines, and in particular to an electromagnetic vibration resistance mechanism. Background Technology

[0002] In fields such as construction and metal processing, universal testing machines are commonly used to break reinforcing bars and other workpieces. When breaking reinforcing bars, universal testing machines generate a huge instantaneous impact force, causing the entire machine to vibrate violently.

[0003] Current technologies primarily rely on springs for shock absorption. Springs depend on the deformation of their elastic structure to dissipate impact force. However, as the spring gradually attenuates vibrational energy through continuous deformation, the equipment remains in a state of vibration with decreasing amplitude for an extended period, requiring considerable time to stabilize. Furthermore, the elastic vibration characteristics of springs can easily induce resonance in the equipment, further aggravating the vibration amplitude and duration, thus affecting equipment accuracy, shortening its lifespan, and even posing safety hazards. In addition, single-spring shock-absorbing structures absorb energy solely through mechanical deformation and cannot actively counteract impact force, resulting in insufficient shock-absorbing efficiency, especially when facing high-frequency or high-load impacts. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the existing technology and provide an electromagnetic anti-seismic mechanism.

[0005] This application provides an electromagnetic shock-absorbing mechanism, comprising: a movable magnetic core connected to a pulling mechanism for receiving vibration impact force transmitted by the pulling mechanism; a coil wound around the movable magnetic core, wherein when the movable magnetic core moves within the coil, the coil can cut magnetic field lines and generate current; and a reverse current control module for detecting the instantaneous maximum current within the coil and supplying a reverse current not less than the instantaneous maximum current value to the coil to counteract vibration impact force through magnetic field action. During the shock-absorbing process, the value of the reverse current gradually decreases as the impact force decays.

[0006] Furthermore, the electromagnetic anti-vibration mechanism also includes a sleeve, with a coil wound around the outside of the sleeve, and a movable channel provided inside the sleeve, with a movable magnetic core slidably disposed within the movable channel.

[0007] Furthermore, the sleeve is made of a non-ferromagnetic material to avoid affecting the magnetic field.

[0008] Furthermore, the electromagnetic anti-vibration mechanism also includes a spring, which is located between the movable magnetic core and the sleeve. One end of the spring is connected to the bottom of the movable magnetic core, and the other end is connected to the bottom wall of the movable channel. When the movable magnetic core is subjected to impact force, the spring can absorb some energy through elastic deformation, thereby slowing down the movement speed of the movable magnetic core and playing the role of buffering the impact force.

[0009] Furthermore, the electromagnetic anti-vibration mechanism also includes a rubber buffer pad, which is located in the movable channel, and the other end of the spring is connected to the rubber buffer pad.

[0010] Furthermore, the bottom of the movable magnetic core is provided with a limiting slot, which is used to limit the installation position of the spring and ensure that the spring maintains the correct force direction during the buffering process.

[0011] Furthermore, the movable magnetic core includes a permanent magnet, an alloy steel mandrel interference-fitted into the permanent magnet, and a stainless steel sheath covering the periphery of the permanent magnet.

[0012] Furthermore, an adhesive layer is provided between the permanent magnet and the alloy steel mandrel, and the thickness of the adhesive layer is 0.08-0.12mm; the adhesive layer is a nano-copper filled modified epoxy resin, wherein the mass ratio of copper powder is 10%-20%.

[0013] Furthermore, the surface roughness Ra of the alloy steel mandrel is ≤0.8μm, which can protect the brittle material of the permanent magnet by reducing assembly stress.

[0014] Furthermore, the reverse current control module includes: a current detection unit for real-time monitoring of the peak current in the coil; and a power supply adjustment unit for dynamically adjusting the reverse current value.

[0015] This application provides an electromagnetic anti-vibration mechanism, including a movable magnetic core, a coil, and a reverse current control module. The movable magnetic core is connected to a pulling mechanism and can move within the coil. When the pulling mechanism pulls out a steel bar and generates an instantaneous impact force, the movable magnetic core moves, the coil cuts magnetic field lines, and generates an instantaneous maximum current. The reverse current control module detects this current and can input a reverse current not less than the instantaneous maximum current into the coil in a very short time. The coil generates a reverse magnetic field, which interacts with the magnetic field of the movable magnetic core to generate an upward electromagnetic repulsion force, actively counteracting the impact force and causing the movable magnetic core to decelerate or even stop instantly, thus achieving a sharp reduction in vibration amplitude. As the impact force decays, the reverse current value is gradually reduced by the power supply regulation unit to avoid excessive electromagnetic force causing the equipment to bounce in the opposite direction. The electromagnetic vibration damping mechanism provided in this application constructs a highly efficient electromagnetic damping vibration damping system through the synergistic effect of a movable magnetic core, coil, and reverse current control module. It can respond to impacts in an extremely short time. Compared to the traditional passive deformation vibration damping method using springs, it can instantly offset most of the vibration energy, shortening the vibration stabilization time from over 200ms with traditional springs to within 30ms, and reducing the peak vibration acceleration from 15g to below 5g, significantly improving vibration damping efficiency. Simultaneously, the natural vibration frequency of springs is prone to coupling with the vibration frequency of equipment, causing resonance. The electromagnetic vibration damping mechanism provided in this application, through electromagnetic damping, can convert vibration energy into electrical energy (Joule heat) for consumption; by dynamically adjusting the reverse current, it can also weaken the vibration amplitude and break the resonance condition, ultimately achieving rapid suppression and adaptive buffering of vibration, which helps enhance the stability and reliability of the universal testing machine in tests such as pull-out rebar. Attached Figure Description

[0016] Figure 1 This application provides a structural schematic diagram of an electromagnetic anti-seismic mechanism;

[0017] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the electromagnetic anti-seismic mechanism. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0019] Universal testing machines are used in fields such as construction and metal processing to test the mechanical properties of workpieces (such as pulling out reinforcing bars). By applying loads to the workpiece and observing the response, the strength, toughness and other indicators of the workpiece can be evaluated.

[0020] The universal testing machine mainly consists of a frame, a pull-out mechanism, and a force measuring system. The frame provides support and a mounting base; the pull-out mechanism includes components such as grippers and drive cylinders, used to clamp the workpiece and apply mechanical loads such as pull-out and tensile forces; the force measuring system typically consists of sensors and display instruments, used to measure and display data such as the force applied to the workpiece and the amount of deformation.

[0021] During testing, steel bars and other workpieces are fixed in the jaws of the pulling mechanism. The jaws are then driven by a hydraulic cylinder or other device to apply gradually increasing tensile or breaking forces to the workpiece. During the application of force, the force measurement system monitors the force value and the state of the workpiece in real time. When the workpiece is broken or the test requirements are met, the relevant data are recorded to evaluate the mechanical properties of the workpiece.

[0022] In steel bar pull-out tests, a huge instantaneous impact force is generated when the steel bar is broken. This application provides an electromagnetic anti-vibration mechanism, including: a movable magnetic core 1, connected to the pull-out mechanism, for receiving the vibration impact force transmitted by the pull-out mechanism; a coil 2, wound around the movable magnetic core 1, which can cut magnetic field lines and generate current when the movable magnetic core 1 moves inside the coil 2; and a reverse current control module, which is used to detect the instantaneous maximum current in the coil 2 and supply a reverse current not less than the instantaneous maximum current value to the coil 2 to counteract the vibration impact force through the magnetic field. During the anti-vibration process, the value of the reverse current gradually decreases as the impact force decays.

[0023] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, coil 2 is made of enameled copper wire wound in the vertical direction with 500-800 turns, forming a cylindrical channel inside coil 2. The movable magnetic core 1 is inserted into the cylindrical channel and can move vertically. The upper end of the movable magnetic core 1 is rigidly connected to a pulling mechanism (such as a gripper or driving cylinder) via bolts, and the lower end extends into the interior of coil 2. Both ends of coil 2 are connected to a reverse current control module via wires. When the movable magnetic core 1 moves axially within coil 2, coil 2 cuts magnetic field lines, generating an induced electromotive force and forming an instantaneous current.

[0024] The reverse current control module is integrated into the equipment's electrical control box. In one embodiment, the reverse current control module includes: a current detection unit for real-time monitoring of the peak current in coil 2; and a power supply adjustment unit for dynamically adjusting the reverse current value.

[0025] Specifically, the current detection unit uses a Hall current sensor with a response time ≤1ms. The power supply regulating unit is a controllable DC power supply based on a PID control algorithm, capable of outputting reverse current within 0.5ms, with a current regulation accuracy of ±1%. The current detection unit and the power supply regulating unit communicate via a CAN bus with a sampling frequency of 10kHz; the power supply regulating unit has a built-in IGBT power module with a maximum output current of 200A and a voltage regulation range of 0-48V.

[0026] During use, the current detection unit monitors the peak current of coil 2 in real time. When an inrush current is detected, the power supply adjustment unit gradually reduces the reverse current at a preset slope (e.g., 100A / ms) to achieve adaptive adjustment of "strong resistance in the early stage of impact and soft buffering in the later stage of impact", thus avoiding the "aftershock" phenomenon of traditional springs.

[0027] In addition, the induced current generated by the coil can be recovered to the device battery through the reverse current control module, thereby improving energy utilization.

[0028] In one specific embodiment, when the pulling mechanism breaks the steel bar and generates an instantaneous impact force, the movable magnetic core 1 moves rapidly downward, and the coil 2 cuts the magnetic field lines, generating an instantaneous maximum current (e.g., 100A). The reverse current control module detects this current and can input a reverse current of not less than the instantaneous maximum current (≥100A) into the coil 2 within a very short time (<1ms); the coil 2 generates a reverse magnetic field, which interacts with the magnetic field of the movable magnetic core 1, generating an upward electromagnetic repulsion force (F=BIL, where B is the magnetic induction intensity, I is the current, and L is the length of the conductor), actively counteracting the impact force, causing the movable magnetic core 1 to decelerate or even stop instantly, thus achieving a sudden reduction in vibration amplitude.

[0029] As the impact force decays, the reverse current value is gradually reduced by the power supply regulation unit (e.g., linearly decreasing from 100A to 0A) to avoid excessive electromagnetic force causing the equipment to reverse and jump.

[0030] The electromagnetic vibration damping mechanism provided in this application constructs a highly efficient electromagnetic damping vibration damping system through the synergistic action of the movable magnetic core 1, coil 2, and reverse current control module. It can respond to impacts in an extremely short time (<1ms). Compared to the traditional passive deformation vibration damping method using springs, it can instantly offset most of the vibration energy, shortening the vibration stabilization time from over 200ms with traditional springs to within 30ms, and reducing the peak vibration acceleration from 15g to below 5g, significantly improving vibration damping efficiency. Simultaneously, the natural vibration frequency of springs is prone to coupling with the vibration frequency of equipment, causing resonance. The electromagnetic vibration damping mechanism provided in this application, through electromagnetic damping, can convert vibration energy into electrical energy (Joule heat) for consumption; by dynamically adjusting the reverse current, it can also weaken the vibration amplitude and break the resonance condition, ultimately achieving rapid suppression and adaptive buffering of vibration, which helps enhance the stability and reliability of the universal testing machine in tests such as pull-out rebar.

[0031] Furthermore, the electromagnetic anti-vibration mechanism provided in this application also includes a sleeve 3, a coil 2 wound around the outside of the sleeve 3, a movable channel provided inside the sleeve, and a movable magnetic core 1 slidably disposed in the movable channel.

[0032] For details, please refer to Figure 2 In the illustrated embodiment, the sleeve 3 is a hollow cylinder, and its inner diameter is 2-3 mm larger than the outer diameter of the movable magnetic core 1, forming a movable channel that facilitates the up-and-down movement of the movable magnetic core 1. The movable channel provides an axial sliding track for the movable magnetic core 1, which can limit the radial offset of the movable magnetic core 1 and ensure the stability of the coil 2 cutting the magnetic field lines.

[0033] Continue to refer to Figure 2 The length of sleeve 3 is the same as the axial length of coil 2, and both ends of sleeve 3 are fixed to the frame of the drawing machine by flanges.

[0034] Optionally, the sleeve 3 is made of a non-ferromagnetic material (such as aluminum alloy or engineering plastic) to avoid affecting the magnetic field.

[0035] Non-ferromagnetic materials prevent the sleeve 3 from becoming magnetized and interfere with the magnetic field coupling between the movable magnetic core 1 and the coil 2, ensuring the effective transmission of electromagnetic force.

[0036] Furthermore, the electromagnetic anti-vibration mechanism provided in this application also includes a spring 4, which is disposed between the movable magnetic core 1 and the sleeve 3. One end of the spring 4 is connected to the bottom of the movable magnetic core 1 and the other end is connected to the bottom wall of the movable channel. When the movable magnetic core 1 is subjected to an impact force, the spring 4 can absorb part of the energy through elastic deformation, thereby slowing down the movement speed of the movable magnetic core 1 and playing the role of buffering the impact force.

[0037] Optionally, the electromagnetic anti-vibration mechanism provided in this application is characterized by further including a rubber buffer pad 5, which is disposed in the movable channel, and the other end of the spring 4 is connected to the rubber buffer pad 5.

[0038] Optionally, the bottom of the movable magnetic core 1 is provided with a limiting slot 11, which is used to limit the installation position of the spring 4 and ensure that the spring 4 maintains the correct force direction during the buffering process.

[0039] For details, please refer to Figure 2 In the illustrated embodiment, spring 4, rubber buffer pad 5, and limiting groove 11 work together to form a mechanical buffer assembly. Spring 4 employs a cylindrical helical compression structure, is made of 65Mn spring steel, and has an elastic modulus of 20-50 N / mm. One end of spring 4 is hooked into the limiting groove 11 at the bottom of the movable magnetic core 1, and the other end is fixed to the rubber buffer pad 5 with bolts. The rubber buffer pad 5 is 10-15 mm thick, made of nitrile rubber, and has a Shore hardness of 60-70A. The rubber buffer pad 5 is secured to the bottom wall of the movable channel with glue or screws. The limiting groove 11 is an annular groove with a depth of 3-5 mm and a width matching the outer diameter of spring 4, ensuring that the axis of spring 4 coincides with the central axis of the movable magnetic core 1 after installation. The limiting groove 11 prevents lateral displacement of spring 4; the rubber buffer pad 5 provides flexible support, improving assembly reliability under long-term vibration conditions.

[0040] More specifically, in the initial stage of the impact, the electromagnetic force preferentially offsets most of the energy of the vibration impact acting on the movable magnetic core 1. The remaining energy is absorbed by the spring 4 through elastic deformation (compression of 5-10mm) to slow down the movement speed of the movable magnetic core 1. In the final stage of the impact, when the spring 4 returns to its original position, the rubber buffer pad 5 consumes the residual vibration energy through viscoelastic deformation, further suppressing the rebound oscillation.

[0041] In one embodiment, the movable magnetic core 1 includes a permanent magnet, an alloy steel mandrel that is interference-fitted into the permanent magnet, and a stainless steel sheath covering the periphery of the permanent magnet.

[0042] Specifically, the movable magnetic core 1 is configured with a three-layer structure, with the innermost layer being an alloy steel core shaft, the outer layer being a permanent magnet, and the outer layer of the permanent magnet being a stainless steel sheath.

[0043] The permanent magnet provides a constant, strong magnetic field (e.g., neodymium iron boron permanent magnet material, magnetic field strength ≥1.2T), which is the basis of the electromagnetic damping effect. The alloy steel mandrel is made of high-strength alloy steel (e.g., 42CrMo steel). The alloy steel mandrel is inserted into the central hole of the permanent magnet through an interference fit (0.02-0.05mm). The alloy steel mandrel bears the impact force transmitted by the pulling mechanism (e.g., the instantaneous load when pulling out a rebar), preventing the brittle permanent magnet from directly breaking under stress. The stainless steel sheath provides physical protection. The stainless steel sheath is made of seamless 304 stainless steel tubing, cold-pressed and wrapped around the periphery of the permanent magnet (1-2mm thick). It isolates the permanent magnet from corrosive media such as moisture and oil, preventing oxidation and demagnetization and helping to extend the lifespan of the core.

[0044] The high strength of the alloy steel mandrel (tensile strength ≥1000MPa) combined with the high magnetic energy product (≥300kJ / m³) of the permanent magnet enables the movable magnetic core 1 to withstand high-frequency impacts. The corrosion-resistant properties of the stainless steel sheath ensure that the movable magnetic core 1 can operate stably for a long time in harsh industrial environments such as humid and dusty conditions.

[0045] Optionally, an adhesive layer is provided between the permanent magnet and the alloy steel mandrel.

[0046] The adhesive layer further strengthens the connection between the alloy steel mandrel and the permanent magnet, ensuring that they do not shift relative to each other under high-frequency vibration and preventing a decrease in magnetic field conduction efficiency or mechanical failure due to loosening. As a flexible interlayer, the adhesive layer also disperses the assembly stress between the alloy steel mandrel and the permanent magnet, preventing stress concentration that could lead to cracking of the permanent magnet (especially for brittle NdFeB permanent magnets). Furthermore, the adhesive layer fills gaps left by interference fits, eliminates microscopic air layers, enhances the overall coaxiality of the magnetic core, ensures a uniform magnetic field distribution during the movement of the movable magnetic core 1, and improves the stability of the electromagnetic damping effect.

[0047] Optionally, the thickness of the adhesive layer is 0.08-0.12 mm.

[0048] When the thickness is too thin (<0.08mm), the adhesive layer cannot completely fill the gap between the parts, which can easily lead to stress concentration, insufficient bonding strength, and long-term vibration may cause interface peeling.

[0049] When the thickness is too thick (>0.12mm), the elastic deformation of the adhesive layer itself increases, which reduces the overall rigidity of the magnetic core, causing the impact force transmission to lag and affecting the response speed of electromagnetic shock resistance (such as the delay in reverse current generation).

[0050] A thickness of 0.08-0.12mm can ensure sufficient filling of gaps and uniform stress distribution, while maintaining core rigidity and ensuring a balance between mechanical and magnetic properties.

[0051] Optionally, the adhesive layer is a nano-copper filled modified epoxy resin, wherein the mass percentage of copper powder is 10%-20%.

[0052] Specifically, the uniform dispersion of nano-copper particles in the epoxy resin fills the micropores within the colloid, enhancing shear resistance and toughness. Compared to adhesive layers made of pure epoxy resin, this helps extend vibration fatigue life. Simultaneously, the high thermal conductivity of copper powder rapidly dissipates the frictional heat generated by the movement of the moving magnetic core 1, preventing demagnetization of the permanent magnet due to temperature increases. Furthermore, copper powder is a non-ferromagnetic material and will not interfere with the magnetic field distribution of the permanent magnet, ensuring that the adhesive layer enhances structural performance without affecting the effectiveness of the electromagnetic damping effect.

[0053] Optionally, the surface roughness Ra of the alloy steel mandrel is ≤0.8μm, which can protect the brittle material of the permanent magnet by reducing assembly stress.

[0054] Precision-machined low-roughness surfaces (Ra≤0.8μm, corresponding to micro-undulations≤4μm) reduce mechanical engagement resistance when mating with permanent magnets, making the interference fit process smoother and preventing scratches on the inner hole of the permanent magnet or localized stress concentration caused by rough surfaces, thus protecting the permanent magnet from damage. Smooth surfaces also help improve the fitting accuracy between the alloy steel mandrel and the central hole of the permanent magnet, ensuring that the axis of the moving magnetic core 1 is aligned with the direction of the magnetic field when moving within the coil 2, avoiding uneven cutting of magnetic field lines by the coil 2 due to eccentricity.

[0055] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electromagnetic shock absorber mechanism, characterized by, include: The movable magnetic core (1) is connected to the pulling mechanism and is used to receive the vibration and impact force transmitted by the pulling mechanism; The coil (2) is wound around the movable magnetic core (1). When the movable magnetic core (1) moves inside the coil (2), the coil (2) can cut magnetic field lines and generate current. The reverse current control module is used to detect the instantaneous maximum current in the coil (2) and supply the coil (2) with a reverse current not less than the instantaneous maximum current value so as to resist the vibration impact force through the magnetic field. During the anti-vibration process, the current value of the reverse current gradually decreases as the impact force decays.

2. The electromagnetic shock resistant mechanism of claim 1, wherein, It also includes a sleeve (3), the coil (2) is wound around the outside of the sleeve (3), the sleeve has a movable channel, and the movable magnetic core (1) is slidably disposed in the movable channel.

3. The electromagnetic shock resistant mechanism of claim 2, wherein, The sleeve (3) is made of non-ferromagnetic material to avoid affecting the magnetic field.

4. The electromagnetic shock resistant mechanism of claim 2, wherein, It also includes a spring (4), which is located between the movable magnetic core (1) and the sleeve (3). One end of the spring (4) is connected to the bottom of the movable magnetic core (1), and the other end is connected to the bottom wall of the movable channel. When the movable magnetic core (1) is subjected to an impact force, the spring (4) can absorb part of the energy through elastic deformation, thereby slowing down the movement speed of the movable magnetic core (1) and playing the role of buffering the impact force.

5. The electromagnetic shock resistant mechanism of claim 4, wherein, It also includes a rubber buffer pad (5), which is located in the active channel, and the other end of the spring (4) is connected to the rubber buffer pad (5).

6. The electromagnetic shock resistant mechanism of claim 4, wherein, The bottom of the movable magnetic core (1) is provided with a limiting slot (11), which is used to limit the installation position of the spring (4) and ensure that the spring (4) maintains the correct force direction during the buffering process.

7. The electromagnetic shock resistant mechanism of claim 1, wherein, The movable magnetic core (1) includes a permanent magnet, an alloy steel core shaft interference-fitted into the permanent magnet, and a stainless steel sheath covering the outer periphery of the permanent magnet.

8. The electromagnetic shock resistant mechanism of claim 7, wherein, An adhesive layer is provided between the permanent magnet and the alloy steel mandrel, and the thickness of the adhesive layer is 0.08-0.12 mm; The adhesive layer is a nano-copper filled modified epoxy resin, wherein the mass percentage of copper powder is 10%-20%.

9. The electromagnetic shock resistant mechanism of claim 7, wherein, The surface roughness Ra of the alloy steel mandrel is ≤0.8μm, which can protect the brittle material of the permanent magnet by reducing assembly stress.

10. The electromagnetic shock resistant mechanism according to any one of claims 1-9, characterized in that, The reverse current control module includes: A current detection unit is used to monitor the peak current in the coil (2) in real time; A power supply regulation unit is used to dynamically adjust the current value of the reverse current.

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