A new energy automobile bolt fastener anti-vibration performance testing device and method

Abstract

The application relates to the technical field of new energy vehicles, and discloses a new energy vehicle bolt fastener anti-vibration performance testing device and method, wherein the new energy vehicle bolt fastener anti-vibration performance testing device comprises a base, a vibration table, an upper test plate and a lower test plate, the upper test plate and the lower test plate are connected through a bolt to be tested, vibration mechanisms are arranged on the front side, the right side and the bottom of the vibration table, the vibration mechanisms comprise linear vibration motors, connecting columns and connecting discs, a plurality of U-shaped claws are fixedly installed on the outer side of the connecting columns, and the U-shaped claws are movably sleeved on the outer side of the connecting discs. The application has the advantages of reasonable design, multi-directional dynamic loading achieved through three-dimensional independent vibration simulation technology, accurate control of independent vibration of the vibration table in the front-rear, left-right and vertical directions through the combination of the three linear vibration motors and the U-shaped claw flexible connection structure, and effective reproduction of a multi-dimensional vibration scene under complex road conditions during the driving of the new energy vehicle.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, and in particular to a device and method for testing the vibration resistance of bolts and fasteners in new energy vehicles. Background Technology

[0002] In the field of vibration performance testing for fasteners in new energy vehicles, traditional technologies mainly rely on single-dimensional vibration simulation and static mechanical analysis, which are insufficient to fully reflect the complex operating conditions of vehicles in motion. Current mainstream testing methods include mechanical loading based on vibration tables, dynamic monitoring using strain gauges or accelerometers, and indirect assessment of preload decay. However, these technologies have significant limitations in terms of simulation realism, dynamic response capture, and intelligent control capabilities, leading to deviations between test results and actual operating conditions, and failing to meet the requirements for high-precision, multi-scenario testing.

[0003] 1. Vibration simulation is disconnected from actual working conditions.

[0004] Existing vibration tests often employ uniaxial or fixed multiaxial periodic excitation, which fails to reproduce the random and variable vibration characteristics of new energy vehicles during operation. For example, multi-degree-of-freedom coupled vibrations under scenarios such as bumpy roads, steering tilt, acceleration, and braking are often simplified in traditional tests to independent loading in unidirectional or orthogonal directions. This simplification ignores the phase difference and frequency superposition effect between vibration directions, resulting in the inability to accurately simulate the combined stress state of bolts under actual road conditions. Furthermore, the damping characteristics of vibration tables are mostly fixed parameters, making it difficult to dynamically adjust energy dissipation and scattering capabilities according to different working conditions (such as gravel roads, emergency braking on ice), further reducing the fidelity of the test scenario.

[0005] 2. Insufficient sensitivity in detecting minor loosening.

[0006] Current technologies for identifying bolt loosening primarily rely on preload threshold judgments or direct measurement by displacement sensors, which exhibit significant lag. In the early, minute slippage stage, before the bolt has undergone macroscopic displacement, the frictional force between the threads has already changed microscopically, making it difficult for traditional sensors to capture the signal. For example, strain gauges can only reflect local stress changes, while accelerometers are insensitive to low-frequency, micro-amplitude vibrations, easily missing critical information in the initial stage of loosening. Furthermore, the simplistic criteria for loosening judgment (such as relying solely on torque decay) fail to comprehensively consider the coupled effects of multiple factors such as vibration amplitude, frequency, and duration, potentially leading to misjudgments or missed detections.

[0007] 3. Data isolation and lack of feedback mechanisms

[0008] Existing testing systems mostly focus on acquiring single physical quantities (such as stress and displacement), lacking the fusion and analysis of multi-source data. Data from devices such as pressure sensors, high-speed cameras, and vibration sensors are typically processed independently, failing to construct a correlation model of mechanical, optical, and electrical parameters. For example, the quantitative relationship between preload decay and thread wear and material fatigue is not yet clear, making it difficult for test results to guide bolt structure optimization. Furthermore, during testing, vibration parameters or damping strength cannot be dynamically adjusted based on real-time data; feedback control relies on human experience, reducing testing efficiency and accuracy.

[0009] 4. The contradiction between safety and efficiency is prominent.

[0010] Traditional testing methods often set conservative vibration limits to prevent equipment damage under extreme conditions, resulting in insufficient simulation of high-intensity operating conditions. For example, scenarios such as transient impact loads during emergency braking and cumulative damage under continuous bumps cannot be fully tested due to safety threshold limitations. Furthermore, test termination conditions often rely on manual observation or preset timeframes; if bolts suddenly loosen, failure to stop the test in time may cause secondary damage (such as damage to the vibration table). This "safety-first" approach sacrifices the test's extreme testing capabilities and makes it difficult to obtain accurate data on bolt failure thresholds. Therefore, we propose a vibration resistance testing device and method for new energy vehicle bolts to address this problem. Summary of the Invention

[0011] The purpose of this invention is to address the shortcomings mentioned in the background section by proposing a device and method for testing the vibration resistance of bolts and fasteners in new energy vehicles.

[0012] To achieve the above objectives, the present invention adopts the following technical solution:

[0013] A vibration performance testing device for bolts in new energy vehicles includes: a base, a vibration table, an upper test plate, and a lower test plate. The upper test plate and the lower test plate are connected by the bolt to be tested. Vibration mechanisms are provided on the front, right, and bottom sides of the vibration table. The vibration mechanism includes: a linear vibration motor, a connecting column, and a connecting plate. Multiple U-shaped claws are fixedly installed on the outside of the connecting column, and the U-shaped claws are movably sleeved on the outside of the connecting plate.

[0014] The vibration table is equipped with locking mechanisms on its left side, rear side and bottom. The locking mechanism includes a fixed frame, a sealing plate, a connecting rod and a circular shell. The fixed frame is fixedly installed with a first electromagnet and two partitions. Two through holes are opened on one side of the partitions. The fixed frame is filled with magnetorheological fluid.

[0015] A linkage mechanism is provided on one side of the upper test plate, and a monitoring and display mechanism is provided on the top side of the base.

[0016] Preferably, the linkage mechanism includes: a sealing box, a piston plate, a connecting ball, a conical disc, an upper horizontal tube, and a lower horizontal tube. A crossbeam is fixedly installed between the sealing box and the upper test plate. A conical groove is provided on one side of the conical disc. The connecting ball movably abuts against the conical groove. A fixing rod is fixedly installed between the connecting ball and the lower test plate. A crossbar is fixedly installed between the other side of the conical disc and the piston plate.

[0017] The bottom two sides of the sealed box are connected to liquid outlet pipes, and a first one-way valve is installed in the liquid outlet pipe. The bottom end of the liquid outlet pipe is connected to the lower horizontal pipe. The top two sides of the sealed box are connected to liquid inlet pipes, and a second one-way valve is installed in the liquid inlet pipe. The top end of the liquid inlet pipe is connected to the upper horizontal pipe.

[0018] A first permanent magnet is fixedly installed on both sides of the piston plate, and a second permanent magnet is fixedly installed on both sides of the inner wall of the sealed box. The magnetic poles of the first permanent magnet and the second permanent magnet on the same side repel each other.

[0019] Preferably, the monitoring and display mechanism includes: an L-shaped box, a horizontal plate, an indicator light, a resistor strip, and a movable conductive plate. The left side of the L-shaped box is connected to a first flexible tube and a connecting pipe. The other end of the first flexible tube is connected to one end of the upper horizontal plate. An electrically controlled valve is installed on the connecting pipe. The bottom end of the connecting pipe is connected to the L-shaped box. The top of the L-shaped box is connected to a second flexible tube. The top end of the second flexible tube is connected to one end of the lower horizontal plate.

[0020] The horizontal plate is slidably installed inside the L-shaped box. A vertical rod is fixedly installed on the top of the horizontal plate. An insulating rod is fixedly installed on the top of the movable conductive plate. The same connecting plate is fixedly installed on the top of the insulating rod and the vertical rod. The movable conductive plate is slidably sleeved on the outside of the resistor strip. An upper plate and a lower plate are fixedly installed on the top and bottom of the resistor strip, respectively. The upper plate and the lower plate are both fixedly installed on the right side of the L-shaped box.

[0021] Preferably, the signal light includes: a lamp cover, a base, a red LED and a green LED, wherein the lamp cover, the red LED and the green LED are fixedly installed on the top of the base, and the base is fixedly installed on the right side of the L-shaped box;

[0022] A power supply is installed at the bottom of the base, and an electronic control switch is installed at the bottom of the power supply.

[0023] The positive terminal of the power supply is electrically connected to one end of the electronic control switch, and the other end of the electronic control switch is electrically connected to the movable conductive plate. The negative terminal of the power supply is electrically connected to one end of the red LED and the green LED. The other end of the red LED is electrically connected to the upper plate, and the other end of the green LED is electrically connected to the lower plate.

[0024] Preferably, a support rod is fixedly installed between the upper test plate and the vibration table, and multiple sets of connecting mechanisms are provided between the lower test plate and the vibration table. The connecting mechanism includes: a connecting rod, a sealing plate, a fixing plate, and a cylinder. The two ends of the connecting rod are fixedly connected to the sealing plate and the cylinder, respectively. Multiple arc-shaped frames are fixedly installed at the top of the cylinder. The arc-shaped frames are sleeved on the outside of the fixing plate. The fixing plate is fixedly installed at the bottom of the lower test plate. A connecting hole is opened at the top of the sealing plate, and a control valve is provided in the connecting hole.

[0025] The bottom of the vibration table is provided with a circular groove and multiple sealing grooves. A connecting hole is provided between the circular groove and the sealing grooves. A second electromagnet is fixedly installed on the inner wall of the top of the circular groove. A piston disk is slidably installed inside the circular groove. The bottom end of the piston disk is fixedly connected to a corresponding connecting disk. The sealing disk is slidably installed in the corresponding sealing groove. The circular groove and the sealing groove are filled with magnetorheological fluid.

[0026] Preferably, a controller and four support plates are fixedly installed on the top of the base, and a support frame is fixedly installed on the top of two of the support plates. A high-speed camera is fixedly installed inside the support frame. A pressure sensor is provided between the upper test plate and the lower test plate. The pressure sensor is signal-connected to the controller. Multiple pressure sensors are configured, and the bottom end of the pressure sensor is fixed to the lower test plate.

[0027] One end of the connecting rod is fixedly connected to the sealing plate, and the other end of the connecting rod is fixedly connected to a disc. The disc is sleeved on the outside of the disc and the disc is fixedly installed on the outside of the vibration table.

[0028] The output end of the linear vibration motor is fixedly connected to one end of the connecting column, and the model of the linear vibration motor is JZD-LV-50.

[0029] This invention also provides a method for testing the vibration resistance performance of bolts in new energy vehicles, applied to the aforementioned testing device for the vibration resistance performance of bolts in new energy vehicles, comprising the following steps:

[0030] S1: Screw the bolt to be tested between the upper and lower test plates and tighten the bolt so that the pressure sensor can monitor the preload.

[0031] S2: The linear vibration motor is started, driving the connecting column to vibrate. The connecting column, through the contact between the U-shaped claw and the connecting plate, drives the vibration table to vibrate along the axial direction of the output shaft of the linear vibration motor. The cooperation of three linear vibration motors allows for individual control of the vibration table in three directions, thus simulating the vibration during car movement. Simultaneously, the vibration table vibrates, and the contact between the circular shell and the circular plate causes the connecting rod and sealing plate to slide within the fixed frame. This allows the magnetorheological fluid within the fixed frame to circulate back and forth within the through holes of the partition. Furthermore, by controlling the energization of the corresponding first electromagnet, magnetism is generated, applying an external magnetic field to the magnetorheological fluid within the fixed frame. The magnetic particles within the magnetorheological fluid become polarized under the influence of the magnetic field, and the magnetic domains within the particles align along the direction of the magnetic field, making each particle a magnetic dipole. Adjacent particles generate a strong attraction due to their magnetic polarity, and this force far exceeds the Brownian motion disturbance force. Driven by the magnetic attraction, the polarized particles move along the magnetic field lines. The fluids attract each other and connect end to end to form a chain-like structure. Multiple chains further bundle together into columnar or mesh-like structures. This structure encapsulates the fluid in the mesh gaps, restricting its flow. After the microstructure is reorganized, the yield stress of the fluid (the minimum shear force required to destroy the structure) increases from below 1 Pa to above 50 kPa. At this point, the fluid exhibits Bingham plastic body behavior: it remains rigid below the critical shear force, and flows above it. Its strength is proportional to the square of the magnetic field strength. The flow of the magnetorheological fluid can be controlled by adjusting the current of the first electromagnet, thereby adjusting the magnetic field strength and thus controlling the sliding resistance of the sealing plate in the fixed frame. This allows for the adjustment of the vibration damping of the vibration table. It can also control the corresponding linear vibration motor to stop running and control the corresponding first electromagnet to increase the magnetic force, thereby achieving vibration control of the vibration platform in two directions or in one direction, thus simulating different usage environments.

[0032] S3: Start the high-speed camera to acquire images of the bolt under test, monitor the change of preload through the pressure sensor, and determine the loosening status of the bolt under test under vibration.

[0033] S4. When the bolt under test loosens slightly, a small relative movement occurs between the upper and lower test plates, causing relative movement between the connecting ball and the sealing box. This movement, through the contact between the connecting ball and the conical disc, moves the conical disc. The conical disc, via the crossbar, moves the piston plate within the sealing box, causing a change in the space on both sides of the piston plate. When the space expands, liquid above the horizontal plate in the L-shaped box is introduced into the expanded space through the first hose, the upper horizontal pipe, and the inlet pipe. When the space shrinks, excess water in the space enters below the horizontal plate in the L-shaped box through the outlet pipe, the lower horizontal pipe, and the second hose, causing the horizontal plate to move upwards. The first and second check valves are both in the downward direction, thus causing the upper and lower test plates to move. When the plate vibrates relative to the horizontal plate, it drives the horizontal plate to move upward continuously. The horizontal plate drives the moving conductive plate upward through the vertical rod, connecting plate and insulating rod, turning on the electric control switch, so that the red and green light-emitting diodes are energized and light up. When the moving conductive plate is at the bottom, the current flowing into the green light-emitting diode is much greater than the current flowing into the red light-emitting diode, so that the light passing through the lampshade is green. As the moving conductive plate moves upward, the current flowing into the green light-emitting diode gradually decreases and the current flowing into the red light-emitting diode gradually increases, so that the green light gradually dims and the red light gradually intensifies. The color of the light emitted by the lampshade changes from pure green to yellow-green to bright yellow to orange-yellow to orange-red to pure red. The looseness can be judged by the color change.

[0034] S5. When the moving conductive plate moves to contact the touch button, it controls all linear vibration motors to stop vibrating, thereby completing the vibration resistance test and avoiding accidents caused by continued vibration. The vibration resistance performance of the bolts and fasteners of new energy vehicles can be judged by measuring the time interval from the start of the vibration test to the stop of vibration.

[0035] Compared with the prior art, the present invention provides a device and method for testing the vibration resistance of bolts and fasteners in new energy vehicles, which has the following beneficial effects:

[0036] (1) Multi-directional dynamic loading is achieved through three-dimensional independent vibration simulation technology. Three linear vibration motors combined with a U-shaped claw flexible connection structure can accurately control the independent vibration of the vibration table in the front-back, left-right and vertical directions, effectively reproducing the multi-dimensional vibration scene under complex road conditions during the driving of new energy vehicles. Compared with traditional single-axis vibration test, this multi-degree-of-freedom coupled vibration mode can more realistically reflect the stress state of bolts in actual working conditions. In particular, it can simulate the impact of composite working conditions such as steering bumps, acceleration and braking on fasteners, providing a test environment close to the actual vehicle for bolt vibration performance evaluation.

[0037] (2) By adopting a magnetorheological fluid intelligent damping adjustment system, the rheological properties of the magnetorheological fluid are dynamically controlled by an electromagnet, thereby achieving stepless adjustment of the vibration table damping. When the first electromagnet is energized, the change in magnetic induction intensity causes the magnetic particles in the magnetorheological fluid to form a chain network structure, and its yield stress increases significantly with the square relationship of the magnetic field strength, thereby accurately controlling the energy dissipation and scattering capability of the vibration system. This active damping adjustment mechanism can quickly switch the vibration mode according to the test requirements, which can simulate extreme road conditions with low damping and high amplitude, and also realize the durability test of high damping steady-state vibration, greatly expanding the scene adaptability of the device.

[0038] (3) The hydraulic amplification system driven by magnetic dipoles through the linkage mechanism converts micro-displacement into hydraulic power through the conical disk-piston plate structure. When the bolt is slightly loose, the relative movement of the connecting ball and the conical groove triggers the piston plate to move. The hydraulic oil is driven to flow in a direction by the repulsion principle of permanent magnets, forming a self-reinforcing displacement amplification effect. Combined with the hydraulic circuit composed of bidirectional one-way valve group, the small amount of loosening is converted into the continuous upward displacement of the horizontal plate. This mechanical-hydraulic coupling design enables the device to have nanometer-level loosening detection sensitivity, which can capture micro-slip phenomenon earlier than macro-loosening.

[0039] (4) The visual monitoring system innovatively adopts a gradient optical warning mechanism. The LED light source is dynamically adjusted by sliding the moving conductive plate on the resistor strip. When the conductive plate is in a low position, the green light-emitting diode obtains a larger current ratio. As the displacement increases, it gradually turns to red as the dominant color, forming a continuous color temperature transition from green to red. This alarm-like light warning system transforms the abstract displacement parameters into intuitive color codes. Testers can quickly judge the degree of bolt loosening by the change in light color. Compared with traditional digital instruments, it has a better on-site warning effect and is particularly suitable for rapid testing scenarios on the production line. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a vibration resistance testing device for bolts and fasteners in new energy vehicles proposed in this invention.

[0041] Figure 2 This is a cross-sectional structural schematic diagram of a vibration resistance testing device for bolts and fasteners in new energy vehicles proposed in this invention.

[0042] Figure 3 for Figure 2 A magnified view of part A in the middle;

[0043] Figure 4 for Figure 2 A magnified view of part B in the middle section;

[0044] Figure 5This is a partial three-dimensional structural diagram of a vibration resistance testing device for bolts and fasteners in new energy vehicles proposed in this invention.

[0045] Figure 6 This is a three-dimensional structural schematic diagram of the vibration mechanism proposed in this invention;

[0046] Figure 7 This is a cross-sectional structural schematic diagram of the locking mechanism proposed in this invention;

[0047] Figure 8 This is a three-dimensional structural diagram of the connecting mechanism proposed in this invention;

[0048] Figure 9 This is a three-dimensional structural diagram of the linkage mechanism and monitoring and display mechanism proposed in this invention;

[0049] Figure 10 This is a cross-sectional structural diagram of the linkage mechanism and monitoring and display mechanism proposed in this invention;

[0050] Figure 11 for Figure 10 A magnified view of part C in the middle;

[0051] Figure 12 for Figure 10 A magnified view of part D in the middle;

[0052] Figure 13 This is a cross-sectional structural schematic diagram of the linkage mechanism proposed in this invention;

[0053] Figure 14 This is a circuit diagram of the signal light proposed in this invention.

[0054] In the diagram: 1. Base; 101. Support plate; 2. Vibration mechanism; 201. Linear vibration motor; 202. Connecting column; 203. U-shaped claw; 204. Connecting disc; 3. Locking mechanism; 301. Fixing frame; 302. Partition plate; 303. Through hole; 304. First electromagnet; 305. Sealing plate; 306. Connecting rod; 307. Disc; 308. Circular shell; 4. Connecting mechanism; 401. Sealing disc; 402. Control valve 403. Connecting rod; 404. Cylinder; 405. Arc frame; 406. Fixing plate; 5. Vibration table; 501. Circular groove; 502. Sealing groove; 503. Piston plate; 504. Second electromagnet; 6. Upper test plate; 601. Support rod; 7. Lower test plate; 701. Pressure sensor; 8. Monitoring and display mechanism; 801. L-shaped box; 802. Signal light; 8021. Base; 8022. Red light-emitting diode; 8 023. Green LED; 8024. Lampshade; 8025. Power supply; 8026. Electrical switch; 803. Connecting pipe; 804. Electrically controlled valve; 805. Second flexible hose; 806. First flexible hose; 807. Horizontal plate; 808. Vertical rod; 809. Connecting plate; 810. Insulating rod; 811. Moving conductive plate; 812. Resistance strip; 813. Lower plate; 814. Upper plate; 815. Touch button; 9. Linkage mechanism ; 901, Sealed box; 902, Piston plate; 903, First permanent magnet; 904, Second permanent magnet; 905, Liquid outlet pipe; 906, Lower horizontal pipe; 907, First one-way valve; 908, Liquid inlet pipe; 909, Upper horizontal pipe; 910, Second one-way valve; 911, Horizontal bar; 912, Conical disc; 913, Connecting ball; 914, Fixing rod; 10, Bolt to be tested; 11, Controller; 12, Support frame; 13, High-speed camera. Detailed Implementation

[0055] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0056] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0057] Reference Figure 1-14A vibration performance testing device for bolts in new energy vehicles includes: a base 1, a vibration table 5, an upper test plate 6 and a lower test plate 7. The upper test plate 6 and the lower test plate 7 are connected by a bolt 10 to be tested. Vibration mechanisms 2 are provided on the front, right and bottom sides of the vibration table 5. The vibration mechanism 2 includes: a linear vibration motor 201, a connecting column 202 and a connecting plate 204. Multiple U-shaped claws 203 are fixedly installed on the outside of the connecting column 202. The U-shaped claws 203 are movably sleeved on the outside of the connecting plate 204.

[0058] Locking mechanisms 3 are provided on the left side, rear side and bottom of the vibration table 5. The locking mechanism 3 includes: a fixed frame 301, a sealing plate 305, a connecting rod 306 and a round shell 308. A first electromagnet 304 and two partitions 302 are fixedly installed in the fixed frame 301. Two through holes 303 are opened on one side of the partition 302. The fixed frame 301 is filled with magnetorheological fluid.

[0059] A linkage mechanism 9 is provided on one side of the upper test plate 6, and a monitoring and display mechanism 8 is provided on the top side of the base 1.

[0060] In this embodiment, the linkage mechanism 9 includes: a sealing box 901, a piston plate 902, a connecting ball 913, a conical disc 912, an upper horizontal tube 909, and a lower horizontal tube 906. A crossbeam is fixedly installed between the sealing box 901 and the upper test plate 6. A conical groove is provided on one side of the conical disc 912. The connecting ball 913 is movably abutted in the conical groove. A fixing rod 914 is fixedly installed between the connecting ball 913 and the lower test plate 7. A crossbar 911 is fixedly installed between the other side of the conical disc 912 and the piston plate 902.

[0061] Both sides of the bottom of the sealing box 901 are connected to the liquid outlet pipe 905. The liquid outlet pipe 905 is equipped with a first one-way valve 907. The bottom end of the liquid outlet pipe 905 is connected to the lower horizontal pipe 906. Both sides of the top of the sealing box 901 are connected to the liquid inlet pipe 908. The liquid inlet pipe 908 is equipped with a second one-way valve 910. The top end of the liquid inlet pipe 908 is connected to the upper horizontal pipe 909.

[0062] First permanent magnets 903 are fixedly installed on both sides of piston plate 902, and second permanent magnets 904 are fixedly installed on both sides of the inner wall of sealed box 901. The magnetic poles of the first permanent magnets 903 and the second permanent magnets 904 on the same side repel each other.

[0063] In this embodiment, the monitoring and display mechanism 8 includes: an L-shaped box 801, a horizontal plate 807, an indicator light 802, a resistor strip 812, and a movable conductive plate 811. The left side of the L-shaped box 801 is connected to a first flexible tube 806 and a connecting tube 803. The other end of the first flexible tube 806 is connected to one end of the upper horizontal plate 807. An electrically controlled valve 804 is provided on the connecting tube 803. The bottom end of the connecting tube 803 is connected to the L-shaped box 801. The top of the L-shaped box 801 is connected to a second flexible tube 805. The top end of the second flexible tube 805 is connected to one end of the lower horizontal tube 906.

[0064] A horizontal plate 807 is slidably installed inside an L-shaped box 801. A vertical rod 808 is fixedly installed on the top of the horizontal plate 807. An insulating rod 810 is fixedly installed on the top of the movable conductive plate 811. The top ends of the insulating rod 810 and the vertical rod 808 are fixedly installed with the same connecting plate 809. The movable conductive plate 811 is slidably sleeved on the outside of the resistor strip 812. An upper plate 814 and a lower plate 813 are fixedly installed at the top and bottom ends of the resistor strip 812, respectively. Both the upper plate 814 and the lower plate 813 are fixedly installed on the right side of the L-shaped box 801.

[0065] In this embodiment, the signal light 802 includes: a lamp cover 8024, a base 8021, a red light-emitting diode 8022, and a green light-emitting diode 8023. The lamp cover 8024, the red light-emitting diode 8022, and the green light-emitting diode 8023 are fixedly installed on the top of the base 8021, and the base 8021 is fixedly installed on the right side of the L-shaped box 801.

[0066] A power supply 8025 is provided at the bottom of the base 8021, and an electric control switch 8026 is provided at the bottom of the power supply 8025;

[0067] The positive terminal of the power supply 8025 is electrically connected to one end of the electronic control switch 8026, and the other end of the electronic control switch 8026 is electrically connected to the movable conductive plate 811. The negative terminal of the power supply 8025 is electrically connected to one end of the red light-emitting diode 8022 and the green light-emitting diode 8023. The other end of the red light-emitting diode 8022 is electrically connected to the upper plate 814, and the other end of the green light-emitting diode 8023 is electrically connected to the lower plate 813.

[0068] In this embodiment, a support rod 601 is fixedly installed between the upper test plate 6 and the vibration table 5. Multiple sets of connecting mechanisms 4 are provided between the lower test plate 7 and the vibration table 5. The connecting mechanism 4 includes: a connecting rod 403, a sealing plate 401, a fixing plate 406 and a cylinder 404. The two ends of the connecting rod 403 are fixedly connected to the sealing plate 401 and the cylinder 404 respectively. Multiple arc-shaped frames 405 are fixedly installed on the top of the cylinder 404. The arc-shaped frames 405 are sleeved on the outside of the fixing plate 406. The fixing plate 406 is fixedly installed at the bottom of the lower test plate 7. A connecting hole 303 is opened on the top of the sealing plate 401. A control valve 402 is provided in the connecting hole 303.

[0069] The bottom of the vibration table 5 is provided with a circular groove 501 and multiple sealing grooves 502. A connecting hole 303 is provided between the circular groove 501 and the sealing grooves 502. A second electromagnet 504 is fixedly installed on the inner wall of the top of the circular groove 501. A piston disk 503 is slidably installed inside the circular groove 501. The bottom end of the piston disk 503 is fixedly connected to the corresponding connecting disk 204. The sealing disk 401 is slidably installed in the corresponding sealing groove 502. The circular groove 501 and the sealing groove 502 are filled with magnetorheological fluid.

[0070] In this embodiment, a controller 11 and four support plates 101 are fixedly installed on the top of the base 1. Support frames 12 are fixedly installed on the top of two support plates 101. A high-speed camera 13 is fixedly installed inside the support frame 12. A pressure sensor 701 is provided between the upper test plate 6 and the lower test plate 7. The pressure sensor 701 is connected to the controller 11. Multiple pressure sensors 701 are provided. The bottom end of the pressure sensor 701 is fixed to the lower test plate 7.

[0071] One end of the connecting rod 306 is fixedly connected to the sealing plate 305, and the other end of the connecting rod 306 is fixedly connected to the disc 307. The disc 308 is sleeved on the outside of the disc 307, and the disc 308 is fixedly installed on the outside of the vibration table 5.

[0072] The output end of the linear vibration motor 201 is fixedly connected to one end of the connecting column 202. The model of the linear vibration motor 201 is JZD-LV-50.

[0073] This invention also provides a method for testing the vibration resistance performance of bolts in new energy vehicles, applied to the aforementioned testing device for the vibration resistance performance of bolts in new energy vehicles, comprising the following steps:

[0074] S1: Screw the bolt to be tested 10 between the upper test plate 6 and the lower test plate 7, and tighten the bolt to be tested 10 so that the pressure sensor 701 monitors the preload force;

[0075] S2: The linear vibration motor 201 is started, driving the connecting column 202 to vibrate. The connecting column 202, through the contact between the U-shaped claw 203 and the connecting disk 204, drives the vibration table 5 to vibrate along the axial direction of the output shaft of the linear vibration motor 201. The vibration of the vibration table 5 in three directions is individually controlled by the cooperation of the three linear vibration motors 201, thereby simulating the vibration during the driving process of a car. While the vibration table 5 vibrates, the contact between the circular shell 308 and the circular disk 307 drives the connecting rod 306 and the sealing plate 305 to slide within the fixed frame 301, allowing the magnetorheological fluid in the fixed frame 301 to flow back and forth in the through hole 303 of the partition 302. Furthermore, by controlling the corresponding first electromagnet 304 to generate magnetism, an external magnetic field is applied to the magnetorheological fluid in the fixed frame 301. The magnetic particles in the magnetorheological fluid are polarized under the action of the magnetic field, and the magnetic domains inside the particles are aligned along the direction of the magnetic field, making each particle a magnetic dipole. Adjacent particles generate a strong attraction due to the anisotropy of magnetic poles, and the force is far greater than that of Brownian motion disturbance. Driven by magnetic attraction, polarized particles attract each other along the direction of magnetic field lines, forming a chain structure. Multiple chains further bundle into columnar or mesh structures. This structure encapsulates the carrier fluid in the mesh gaps, restricting its flow. After microstructure reorganization, the yield stress of the fluid (the minimum shear force required to destroy the structure) increases from below 1 Pa to above 50 kPa. At this time, the fluid exhibits Bingham plastic body behavior: it remains rigid below the critical shear force, and flows above it. Its strength is proportional to the square of the magnetic field strength. The flow of the magnetorheological fluid can be controlled by adjusting the current of the first electromagnet 304, thereby adjusting the magnetic field strength and thus adjusting the sliding resistance of the sealing plate 305 in the fixed frame 301. This allows for the adjustment of the vibration damping of the vibration table 5, and can also control the corresponding linear vibration motor 201 to stop operating and control the corresponding first electromagnet 304 to increase the magnetic force, thereby achieving vibration control of the vibration platform in two directions or in one direction, thus simulating different usage environments.

[0076] S3: Start the high-speed camera 13 to acquire images of the bolt 10 under test, monitor the change of preload through the pressure sensor 701, and determine the loosening status of the bolt 10 under test under vibration.

[0077] S4. When the bolt 10 to be tested loosens slightly, a small relative movement occurs between the upper test plate 6 and the lower test plate 7, causing relative movement between the connecting ball 913 and the sealing box 901. This movement, through the contact between the connecting ball 913 and the conical disc 912, moves the conical disc 912. The conical disc 912, via the crossbar 911, moves the piston plate 902 within the sealing box 901, causing a change in the space on both sides of the piston plate 902. When the space expands, liquid above the horizontal plate 807 in the L-shaped box 801 is introduced into the expanded space through the first hose 806, the upper horizontal pipe 909, and the inlet pipe 908. When the space shrinks, excess water in the space enters below the horizontal plate 807 in the L-shaped box 801 through the outlet pipe 905, the lower horizontal pipe 906, and the second hose 805, causing the horizontal plate 807 to move upwards. The first one-way valve 907 and the second one-way valve 910 are both in the downward direction, thus allowing the upper test plate 807 to move upwards. When plate 6 and lower test plate 7 vibrate relative to each other, they cause horizontal plate 807 to move continuously upward. Horizontal plate 807, through vertical rod 808, connecting plate 809 and insulating rod 810, causes movable conductive plate 811 to move upward, turning on electrical control switch 8026. This causes red LED 8022 and green LED 8023 to be energized and illuminate. When movable conductive plate 811 is at its lowest point, the current flowing into green LED 8023 is much greater than the current flowing into red LED 8022, making the light passing through lampshade 8024 green. As movable conductive plate 811 moves upward, the current flowing into green LED 8023 gradually decreases while the current flowing into red LED 8022 gradually increases, causing the green light to gradually dim and the red light to gradually intensify. This causes the light emitted by lampshade 8024 to change from pure green to yellow-green to bright yellow to orange-yellow to orange-red to pure red, thus allowing the looseness to be judged by the color change.

[0078] S5. When the movable conductive plate 811 moves to contact the touch button 815, it controls the linear vibration motor 201 to stop vibrating, thereby completing the vibration resistance test and avoiding accidents caused by continued vibration. The vibration resistance performance of the bolts and fasteners of new energy vehicles can be judged by measuring the time interval from the start of the vibration test to the stop of vibration.

[0079] In this embodiment, multi-directional dynamic loading is achieved through three-dimensional independent vibration simulation technology. Three linear vibration motors 201, combined with a U-shaped claw 203 flexible connection structure, can precisely control the independent vibration of the vibration table 5 in the front-back, left-right, and vertical directions. This effectively reproduces the multi-dimensional vibration scenarios under complex road conditions during the driving of new energy vehicles. Compared to traditional single-axis vibration testing, this multi-degree-of-freedom coupled vibration mode more realistically reflects the stress state of bolts under actual working conditions. In particular, it can simulate the impact of combined working conditions such as steering bumps and acceleration / braking on fasteners, providing a near-real-vehicle testing environment for bolt vibration resistance performance evaluation. The intelligent damping adjustment system using magnetorheological fluid dynamically regulates the rheological properties of the magnetorheological fluid via electromagnets, achieving stepless adjustment of the damping of the vibration table 5. When the first electromagnet 304 is energized, the change in magnetic induction intensity causes the magnetic particles in the magnetorheological fluid to form a chain-like network structure, significantly increasing its yield stress with respect to the square of the magnetic field strength. This precisely controls the energy dissipation and scattering capability of the vibration system. This active damping adjustment mechanism can quickly switch vibration modes according to testing requirements, simulating both extreme road conditions with low damping and high amplitude, and endurance testing of high-damping steady-state vibration, greatly expanding the device's adaptability to various scenarios. The linkage mechanism 9 employs a hydraulic amplification system driven by a magnetic dipole. Through the structure of the conical disc 912 and piston plate 902, micro-displacement is converted into hydraulic power. When the bolt becomes slightly loose, the relative movement of the connecting ball 913 and the conical groove triggers the piston plate 902 to move. Utilizing the repulsive principle of permanent magnets, the hydraulic oil flows in a directional manner, creating a self-reinforcing displacement amplification effect. Combined with a hydraulic circuit composed of a bidirectional check valve group, the minute loosening is converted into a continuous upward displacement of the horizontal plate 807. This mechanical-hydraulic coupling design gives the device nanometer-level loosening detection sensitivity, enabling it to capture micro-slippage phenomena that precede macroscopic loosening. The visual monitoring system innovatively employs a gradient optical warning mechanism. By sliding a movable conductive plate 811 across a resistor strip 812, the LED light source is dynamically adjusted. When the conductive plate is in a low position, the green LED 8023 receives a larger current proportion. As the displacement increases, it gradually transitions to red dominance, forming a continuous color temperature transition from green to red. This alarm-like light warning system transforms abstract displacement parameters into intuitive color codes. Testers can quickly determine the degree of bolt loosening through changes in light color. Compared to traditional digital instruments, it offers a more effective on-site warning effect and is particularly suitable for rapid inspection scenarios on production lines.

[0080] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

Claims

1. A device for testing the vibration resistance of bolts and fasteners in new energy vehicles, characterized in that, include: The base (1), vibration table (5), upper test plate (6) and lower test plate (7) are connected by test bolts (10). The vibration table (5) is provided with vibration mechanism (2) on the front, right and bottom sides. The vibration mechanism (2) includes: linear vibration motor (201), connecting column (202) and connecting plate (204). Multiple U-shaped claws (203) are fixedly installed on the outside of the connecting column (202). The U-shaped claws (203) are movably sleeved on the outside of the connecting plate (204). The vibration table (5) is provided with locking mechanisms (3) on the left side, rear side and bottom. The locking mechanism (3) includes: a fixed frame (301), a sealing plate (305), a connecting rod (306) and a round shell (308). The fixed frame (301) is fixedly installed with a first electromagnet (304) and two partitions (302). Two through holes (303) are opened on one side of the partition (302). The fixed frame (301) is filled with magnetorheological fluid. A linkage mechanism (9) is provided on one side of the upper test plate (6), and a monitoring and display mechanism (8) is provided on the top side of the base (1). The linkage mechanism (9) includes: a sealing box (901), a piston plate (902), a connecting ball (913), a conical disc (912), an upper horizontal tube (909), and a lower horizontal tube (906). A crossbeam is fixedly installed between the sealing box (901) and the upper test plate (6). A conical groove is provided on one side of the conical disc (912). The connecting ball (913) moves and abuts against the conical groove. A fixing rod (914) is fixedly installed between the connecting ball (913) and the lower test plate (7). A crossbar (911) is fixedly installed between the other side of the conical disc (912) and the piston plate (902). The bottom two sides of the sealed box (901) are connected to the liquid outlet pipe (905), and the liquid outlet pipe (905) is provided with a first one-way valve (907). The bottom end of the liquid outlet pipe (905) is connected to the lower horizontal pipe (906). The top two sides of the sealed box (901) are connected to the liquid inlet pipe (908), and the liquid inlet pipe (908) is provided with a second one-way valve (910). The top end of the liquid inlet pipe (908) is connected to the upper horizontal pipe (909). The piston plate (902) is fixedly installed with a first permanent magnet (903) on both sides, and the sealing box (901) is fixedly installed with a second permanent magnet (904) on both sides of the inner wall. The magnetic poles of the first permanent magnet (903) and the second permanent magnet (904) on the same side repel each other. The monitoring and display mechanism (8) includes: an L-shaped box (801), a horizontal plate (807), an indicator light (802), a resistor strip (812), and a movable conductive plate (811). The left side of the L-shaped box (801) is connected to a first flexible tube (806) and a connecting pipe (803). The other end of the first flexible tube (806) is connected to one end of the horizontal plate (807). An electric control valve (804) is provided on the connecting pipe (803). The bottom end of the connecting pipe (803) is connected to the L-shaped box (801). The top of the L-shaped box (801) is connected to a second flexible tube (805). The top end of the second flexible tube (805) is connected to one end of the lower horizontal pipe (906). The horizontal plate (807) is slidably installed inside the L-shaped box (801). A vertical rod (808) is fixedly installed on the top of the horizontal plate (807). An insulating rod (810) is fixedly installed on the top of the movable conductive plate (811). The same connecting plate (809) is fixedly installed on the top of the insulating rod (810) and the vertical rod (808). The movable conductive plate (811) is slidably sleeved on the outside of the resistor strip (812). An upper plate (814) and a lower plate (813) are fixedly installed on the top and bottom of the resistor strip (812), respectively. The upper plate (814) and the lower plate (813) are both fixedly installed on the right side of the L-shaped box (801).

2. The vibration resistance testing device for new energy vehicle bolts and fasteners according to claim 1, characterized in that, The signal light (802) includes: a lampshade (8024), a base (8021), a red light-emitting diode (8022), and a green light-emitting diode (8023). The lampshade (8024), the red light-emitting diode (8022), and the green light-emitting diode (8023) are fixedly installed on the top of the base (8021), and the base (8021) is fixedly installed on the right side of the L-shaped box (801). A power supply (8025) is provided at the bottom of the base (8021), and an electric control switch (8026) is provided at the bottom of the power supply (8025). The positive terminal of the power supply (8025) is electrically connected to one end of the electronic control switch (8026), and the other end of the electronic control switch (8026) is electrically connected to the movable conductive plate (811). The negative terminal of the power supply (8025) is electrically connected to one end of the red light-emitting diode (8022) and the green light-emitting diode (8023). The other end of the red light-emitting diode (8022) is electrically connected to the upper plate (814), and the other end of the green light-emitting diode (8023) is electrically connected to the lower plate (813).

3. The vibration resistance testing device for new energy vehicle bolts and fasteners according to claim 2, characterized in that, A support rod (601) is fixedly installed between the upper test plate (6) and the vibration table (5). Multiple sets of connecting mechanisms (4) are provided between the lower test plate (7) and the vibration table (5). The connecting mechanism (4) includes: a connecting rod (403), a sealing plate (401), a fixing plate (406), and a cylinder (404). The two ends of the connecting rod (403) are fixedly connected to the sealing plate (401) and the cylinder (404) respectively. Multiple arc-shaped frames (405) are fixedly installed on the top of the cylinder (404). The arc-shaped frames (405) are sleeved on the outside of the fixing plate (406). The fixing plate (406) is fixedly installed at the bottom of the lower test plate (7). A connecting hole is opened on the top of the sealing plate (401). A control valve (402) is provided in the connecting hole. The bottom of the vibration table (5) is provided with a circular groove (501) and a plurality of sealing grooves (502). A connecting hole is provided between the circular groove (501) and the sealing grooves (502). A second electromagnet (504) is fixedly installed on the inner wall of the top of the circular groove (501). A piston disk (503) is slidably installed inside the circular groove (501). The bottom end of the piston disk (503) is fixedly connected to the corresponding connecting disk (204). The sealing disk (401) is slidably installed in the corresponding sealing groove (502). The circular groove (501) and the sealing groove (502) are filled with magnetorheological fluid.

4. The vibration resistance testing device for new energy vehicle bolts and fasteners according to claim 3, characterized in that, The top of the base (1) is fixedly equipped with a controller (11) and four support plates (101), of which two support plates (101) are fixedly equipped with support frames (12), and a high-speed camera (13) is fixedly installed inside the support frame (12). A pressure sensor (701) is provided between the upper test plate (6) and the lower test plate (7). The pressure sensor (701) is connected to the controller (11) by signal. The pressure sensor (701) is configured in multiple groups, and the bottom end of the pressure sensor (701) is fixed to the lower test plate (7). One end of the connecting rod (306) is fixedly connected to the sealing plate (305), and the other end of the connecting rod (306) is fixedly connected to the disc (307). The disc (308) is sleeved on the outside of the disc (307), and the disc (308) is fixedly installed on the outside of the vibration table (5). The output end of the linear vibration motor (201) is fixedly connected to one end of the connecting column (202), and the model of the linear vibration motor (201) is JZD-LV-50.

5. A method for testing the vibration resistance performance of bolts in new energy vehicles, applied to the vibration resistance performance testing device for new energy vehicle bolts as described in claim 4, characterized in that, Includes the following steps: S1: Screw the bolt to be tested (10) between the upper test plate (6) and the lower test plate (7), and tighten the bolt to be tested (10) so that the pressure sensor (701) monitors the preload; S2: Start the linear vibration motor (201) to drive the connecting column (202) to vibrate. The connecting column (202) drives the vibration table (5) to vibrate along the axial direction of the output shaft of the linear vibration motor (201) through the contact between the U-shaped claw (203) and the connecting plate (204). Through the cooperation of the three linear vibration motors (201), the vibration of the vibration table (5) in three directions can be controlled individually, thereby simulating the vibration during the driving process of a car. While the vibration table (5) vibrates, the circular shell (308) and the circular plate (307) vibrate simultaneously. The contact between the connecting rod (306) and the sealing plate (305) causes them to slide within the fixed frame (301), allowing the magnetorheological fluid within the fixed frame (301) to circulate back and forth within the through hole (303) of the partition plate (302). Furthermore, by controlling the energization of the corresponding first electromagnet (304), magnetism is generated, applying an external magnetic field to the magnetorheological fluid within the fixed frame (301). The magnetic particles within the magnetorheological fluid become polarized under the influence of the magnetic field, and the magnetic domains within the particles align along the direction of the magnetic field, making each particle a magnetic dipole. Adjacent particles become magnetic dipoles due to the magnetic field. The polarity generates a strong attraction force, which far exceeds the Brownian motion disturbance force. Under the drive of magnetic attraction, the polarized particles attract each other along the direction of the magnetic field lines and form a chain structure. Multiple chains further bundle into a columnar or mesh structure. This structure wraps the carrier liquid in the mesh gaps, restricting its flow. After the microstructure is reorganized, the yield stress of the fluid increases from below 1 Pa to above 50 kPa. At this time, the fluid exhibits Bingham plastic body behavior: it remains rigid below the critical shear force and flows above it. Its strength is proportional to the square of the magnetic field strength. The magnetic field strength can be adjusted by adjusting the current of the first electromagnet (304), thereby controlling the flow of the magnetorheological fluid. This adjusts the sliding resistance of the sealing plate (305) in the fixed frame (301) to achieve the adjustment of the vibration damping of the vibration table (5). It also controls the corresponding linear vibration motor (201) to stop running and controls the corresponding first electromagnet (304) to increase the magnetic force, thereby achieving vibration control of the vibration platform in two directions or in one direction, thus simulating different usage environments. S3: Start the high-speed camera (13) to acquire images of the bolt (10) under test, monitor the change of preload through the pressure sensor (701) and determine the loosening status of the bolt (10) under vibration. S4. When the bolt (10) to be tested loosens slightly, a small amount of relative movement occurs between the upper test plate (6) and the lower test plate (7), which causes relative movement between the connecting ball (913) and the sealing box (901). This causes the conical disc (912) to move through the contact between the connecting ball (913) and the conical disc (912). The conical disc (912) then moves the piston plate (902) within the sealing box (901) via the crossbar (911), causing a change in the space on both sides of the piston plate (902). When the space expands, the liquid above the horizontal plate (807) inside the L-shaped box (801) is introduced into the expanded space through the first hose (806), the upper horizontal pipe (909), and the inlet pipe (908). When the space shrinks, excess water in the space enters below the horizontal plate (807) inside the L-shaped box (801) through the outlet pipe (905), the lower horizontal pipe (906), and the second hose (805), thereby causing the horizontal plate (807) to move upward. The conduction direction of the first one-way valve (907) and the second one-way valve (910) is both from top to bottom. This causes the upper test plate (6) and the lower test plate (7) to vibrate relative to each other, causing the horizontal plate (807) to move continuously upward. The horizontal plate (807) drives the moving conductive plate (811) to move upward through the vertical rod (808), the connecting plate (809) and the insulating rod (810), turning on the electronic control switch (8026), which causes the red light-emitting diode (8022) and the green light-emitting diode (8023) to be energized and light up. When the moving conductive plate (811) is at the bottom, the current flowing into the green light-emitting diode (8023) is generated. The current is much greater than that in the red LED (8022), so that the light passing through the lampshade (8024) is green. As the moving conductive plate (811) moves upward, the current flowing into the green LED (8023) gradually decreases and the current flowing into the red LED (8022) gradually increases, so that the green light gradually dims and the red light gradually becomes stronger. The color of the light emitted by the lampshade (8024) changes from pure green to yellow-green to bright yellow to orange-yellow to orange-red to pure red. The looseness can be judged by the color change. S5. When the moving conductive plate (811) moves to contact the touch button (815), it controls all linear vibration motors (201) to stop vibrating, thereby completing the vibration test and avoiding accidents caused by continued vibration. The vibration performance of the bolt fasteners of new energy vehicles can be judged by measuring the time interval from the start of the vibration test to the stop of vibration.

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