Device and method for testing anti-vibration performance of new energy automobile bolt firmware

Abstract

The invention relates to the technical field of new energy automobiles, and discloses a new energy automobile bolt firmware anti-vibration performance testing device and method.The new energy automobile bolt firmware anti-vibration performance testing device comprises a base, a vibration table, an upper testing plate and a lower testing plate, and the upper testing plate and the lower testing plate are connected through a to-be-tested bolt; vibration mechanisms are arranged on the front side, the right side and the bottom of the vibration table, each vibration mechanism comprises a linear vibration motor, a connecting column and a connecting disc, a plurality of U-shaped claws are fixedly installed on the outer side of each connecting column, and the U-shaped claws are movably connected to the outer sides of the connecting discs in a sleeving mode. The device is reasonable in design, multidirectional dynamic loading is achieved through the three-dimensional independent vibration simulation technology, the three linear vibration motors are combined with the U-shaped claw flexible connection structure, independent vibration of the vibration table in the front-back direction, the left-right direction and the vertical direction can be accurately controlled, and a multidimensional vibration scene under the complex road condition in the new energy automobile running process is effectively reproduced.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a device and method for testing the vibration resistance of bolt fasteners of new energy vehicles. Background Art

[0002] In the field of vibration resistance testing of fasteners in new energy vehicles, traditional technologies rely primarily on single-dimensional vibration simulation and static mechanical analysis, which are unable to fully reflect the complex operating conditions of vehicles in motion. Current mainstream testing methods include mechanical loading using a vibration table, dynamic monitoring using strain gauges or accelerometers, and indirect assessment of preload attenuation. However, these technologies have significant limitations in simulation realism, dynamic response capture, and intelligent control capabilities. This leads to deviations between test results and actual operating conditions, making it difficult to meet the needs of high-precision, multi-scenario testing.

[0003] 1. Vibration simulation is out of touch with actual operating conditions Existing vibration tests mostly use single-axis or fixed multi-axis periodic excitation, which cannot reproduce the random and variable vibration characteristics of new energy vehicles during driving. For example, multi-degree-of-freedom coupled vibrations in scenarios such as bumpy roads, steering tilt, acceleration and braking are often simplified to independent loading in one direction or orthogonal directions in traditional tests. This simplification ignores the phase difference and frequency superposition effect between vibration directions, resulting in the inability to accurately simulate the complex stress state of the bolts under actual road conditions. In addition, the damping characteristics of the vibration table are mostly fixed parameters, making it difficult to dynamically adjust the energy dissipation capacity according to different working conditions (such as gravel roads and emergency braking on icy surfaces), further reducing the degree of restoration of the test scenario.

[0004] 2. Insufficient sensitivity in micro-loosening detection Current technologies for identifying bolt loosening primarily rely on preload threshold judgment or direct displacement sensor measurement, which exhibits significant lag. In the early stages of micro-slippage, the bolt has not yet produced macroscopic displacement, but the friction between the threads has already undergone microscopic changes, 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 and can easily miss critical information in the initial stages of loosening. Furthermore, the simplification of loosening determination criteria (e.g., relying solely on torque attenuation) without considering the coupling of multiple factors such as vibration amplitude, frequency, and duration, can lead to misjudgments or missed judgments.

[0005] 3. Data isolation and lack of feedback mechanisms Existing testing systems often focus on collecting single physical quantities (such as stress and displacement) and lack the ability to integrate and analyze multi-source data. Data from devices such as pressure sensors, high-speed cameras, and vibration sensors are typically processed independently, failing to establish a correlation model between mechanical, optical, and electrical parameters. For example, the quantitative relationship between preload attenuation and thread wear and material fatigue remains unclear, making it difficult for test results to guide bolt structure optimization. Furthermore, during the test, vibration parameters or damping strength cannot be dynamically adjusted based on real-time data, and feedback control relies on manual experience, reducing test efficiency and accuracy.

[0006] 4. The contradiction between safety and efficiency is prominent To prevent equipment damage under extreme conditions, traditional testing often sets a conservative upper vibration limit, resulting in insufficient simulation of high-intensity conditions. For example, scenarios such as transient impact loads during emergency braking and cumulative damage under continuous turbulence cannot be fully tested due to safety threshold restrictions. In addition, the test termination conditions often rely on manual observation or preset time. If the bolts suddenly loosen, secondary damage (such as damage to the vibration table) may occur due to failure to shut down in time. This "safety first" mode sacrifices the test's extreme testing capabilities and makes it difficult to obtain accurate data on the bolt failure threshold; therefore, we propose a vibration resistance performance test device and method for new energy vehicle bolt firmware to solve this problem. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings mentioned in the above background technology and to propose a vibration resistance performance testing device and method for bolt fasteners of new energy vehicles.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions: A vibration resistance testing device for bolt fasteners of new energy vehicles, comprising: a base, a vibration table, an upper test plate, and a lower test plate, wherein the upper test plate and the lower test plate are connected by bolts to be tested; a vibration mechanism is provided on the front, right, and bottom of the vibration table, and the vibration mechanism comprises: a linear vibration motor, a connecting column, and a connecting plate; a plurality of U-shaped claws are fixedly mounted on the outer side of the connecting column, and the U-shaped claws are movably sleeved on the outer side of the connecting plate; The left side, rear side and bottom of the vibration table are each provided with a locking mechanism, which includes: a fixed frame, a sealing plate, a connecting rod and a round shell. A first electromagnet and two partitions are fixedly installed in the fixed frame, and two through holes are formed on one side of the partition. The fixed frame is filled with magnetorheological fluid; A linkage mechanism is provided on one side of the upper test plate, and a monitoring and display mechanism is provided on one side of the top of the base.

[0009] Preferably, the linkage mechanism includes: a sealing box, a piston plate, a connecting ball, a conical disk, an upper cross tube and a lower cross tube, a cross beam is fixedly installed between the sealing box and the upper test plate, a conical groove is provided on one side of the conical disk, the connecting ball movably abuts in the conical groove, a fixing rod is fixedly installed between the connecting ball and the lower test plate, and a cross bar is fixedly installed between the other side of the conical disk and the piston plate; Both sides of the bottom of the sealed box are connected to a liquid outlet pipe, a first one-way valve is provided in the liquid outlet pipe, the bottom end of the liquid outlet pipe is connected to the lower horizontal pipe, and both sides of the top of the sealed box are connected to a liquid inlet pipe, a second one-way valve is provided in the liquid inlet pipe, and the top end of the liquid inlet pipe is connected to the upper horizontal pipe; First permanent magnets are fixedly mounted on both sides of the piston plate, and second permanent magnets are fixedly mounted on both inner walls of the sealing box. The first permanent magnet and the second permanent magnet on the same side have opposite magnetic poles that repel each other.

[0010] Preferably, the monitoring and display mechanism includes: an L-shaped box, a horizontal plate, a signal light, a resistance bar, and a movable conductive plate; the left side of the L-shaped box is connected to a first hose and a connecting pipe; the other end of the first hose is connected to one end of the upper horizontal plate; the connecting pipe is provided with an electric control valve; 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 hose; the top end of the second hose is connected to one end of the lower horizontal pipe; The horizontal plate is slidably installed in 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 top of the insulating rod and the vertical rod are fixedly installed with the same connecting plate, the movable conductive plate is slidably sleeved on the outside of the resistor bar, the top and bottom of the resistor bar are respectively fixedly installed with an upper plate and a lower plate, and the upper plate and the lower plate are both fixedly installed on the right side of the L-shaped box.

[0011] Preferably, the signal light comprises: a lampshade, a base, a red light emitting diode and a green light emitting diode, wherein the lampshade, the red light emitting diode and the green light emitting diode are fixedly mounted on the top of the base, and the base is fixedly mounted on the right side of the L-shaped box; A power supply is provided at the bottom of the base, and an electric control switch is provided at the bottom of the power supply; The positive pole of the power supply is electrically connected to one end of the electric control switch, the other end of the electric control switch is electrically connected to the movable conductive plate, the negative pole of the power supply is electrically connected to one end of the red light-emitting diode and the green light-emitting diode, the other end of the red light-emitting diode is electrically connected to the upper plate, and the other end of the green light-emitting diode is electrically connected to the lower plate.

[0012] Preferably, a support rod is fixedly installed between the upper test plate and the vibration table, and multiple groups of connection mechanisms are provided between the lower test plate and the vibration table, and the connection mechanisms include: a connection rod, a sealing disk, a fixed disk and a cylinder, the two ends of the connection rod are fixedly connected to the sealing disk and the cylinder respectively, and a plurality of arc frames are fixedly installed on the top of the cylinder, and the arc frames are sleeved on the outside of the fixed disk, and the fixed disk is fixedly installed on the bottom end of the lower test plate, and a connecting hole is opened on the top of the sealing disk, and a control valve is provided in the connecting hole; A circular groove and multiple sealing grooves are provided at the bottom of the vibration table, a connecting hole is provided between the circular groove and the sealing groove, a second electromagnet is fixedly installed on the top inner wall 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 the corresponding connecting disk, the sealing disk is slidably installed in the corresponding sealing groove, and the circular groove and the sealing groove are filled with magnetorheological fluid.

[0013] Preferably, a controller and four support plates are fixedly installed on the top of the base, wherein a support frame is fixedly installed on the top of two of the support plates, a high-speed camera is fixedly installed in the support frame, a pressure sensor is provided between the upper test plate and the lower test plate, the pressure sensor is connected to the controller signal, the pressure sensors are arranged in multiple groups, and the bottom end of the pressure sensor is fixed to the lower test plate; 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 the disc. The circular shell is sleeved on the outer side of the disc, and the circular shell is fixedly installed on the outer side of the vibration table. 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.

[0014] The present invention also provides a method for testing the vibration resistance of bolt fasteners of new energy vehicles, which is applied to the above-mentioned device for testing the vibration resistance of bolt fasteners of new energy vehicles, and includes the following steps: S1: Screw the bolt to be tested between the upper test plate and the lower test plate, and tighten the bolt to be tested so that the pressure sensor monitors the preload force; S2: Start the linear vibration motor to drive the connecting column to vibrate. The connecting column drives the vibration table to vibrate along the axial direction of the output shaft of the linear vibration motor through the abutment between the U-shaped claw and the connecting disk. The three linear vibration motors cooperate to realize independent control of the vibration of the vibration table in three directions, thereby simulating the vibration of the car during driving. While the vibration table vibrates, the abutment between the circular shell and the circular disk drives the connecting rod and the sealing plate to slide in the fixed frame, so that the magnetorheological fluid in the fixed frame circulates back and forth in the through hole of the partition, and the magnetism can be generated by controlling the power supply of the corresponding first electromagnet to apply an external magnetic field to the magnetorheological fluid in the fixed frame. The magnetic particles in the magnetorheological fluid are polarized under the action of the magnetic field, and the magnetic domains inside the particles are arranged along the direction of the magnetic field, so that each particle becomes a magnetic dipole. The adjacent particles generate a strong attraction due to the anisotropy of the magnetic poles, and the force is far greater than the disturbance force of Brownian motion. The polarized particles are driven by the magnetic attraction along the magnetic lines. The chains are further bundled into a columnar or mesh structure, which wraps the carrier liquid in the grid gap and restricts its fluidity. After the microstructure is reorganized, the yield stress of the fluid (the minimum shear force required to destroy the structure) increases from the initial 1Pa to more than 50kPa. At this time, the fluid exhibits Bingham plastic behavior: it remains rigid below the critical shear force and flows when it exceeds the critical shear force. The strength of the fluid is proportional to the square of the magnetic field strength. The fluidity of the magnetorheological fluid can be controlled by adjusting the current of the first electromagnet and then the magnetic field strength, thereby adjusting the sliding resistance of the sealing plate in the fixed frame to achieve the adjustment of the vibration damping of the vibration platform. The corresponding linear vibration motor can be controlled to stop running and the corresponding first electromagnet can be controlled to increase the magnetic force to achieve vibration control of the vibration platform in two directions or one direction, thereby simulating different usage environments. S3: Start the high-speed camera to collect images of the bolt to be tested, monitor the change of preload force through the pressure sensor, and determine the looseness of the bolt to be tested under vibration; S4. When the bolt to be tested is slightly loosened, a small amount of relative movement occurs between the upper test plate and the lower test plate, which causes relative movement between the connecting ball and the sealing box, thereby driving the conical disk to move through the contact between the connecting ball and the conical disk, and the conical disk drives the piston plate to move in the sealing box through the cross rod, so that the space on both sides of the piston plate changes, and when the space becomes larger, the liquid above the horizontal plate in the L-shaped box is input into the enlarged space through the first hose, the upper cross pipe and the liquid inlet pipe. When the space becomes smaller, the excess water in the space enters the bottom of the horizontal plate in the L-shaped box through the liquid outlet pipe, the lower cross pipe and the second hose, thereby driving the horizontal plate to move upward. The conduction direction of the first one-way valve and the second one-way valve is from top to bottom, so that the upper test plate and the lower test plate are relatively close to each other. When the plate vibrates relative to the plate, it drives the horizontal plate to move upward continuously. The horizontal plate drives the movable conductive plate upward through the vertical rod, the connecting plate and the insulating rod, turning on the electric control switch, so that the red and green LEDs are energized and light up. When the movable conductive plate is at the bottom, the current flowing into the green LED is much greater than the current flowing into the red LED, so that the light passing through the lampshade is green. As the movable conductive plate moves upward, the current flowing into the green LED gradually decreases and the current flowing into the red LED 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 changes from pure green to yellow-green to bright yellow to orange-yellow to orange-red to pure red, so the looseness can be judged by the color change. S5. When the conductive plate moves to contact the touch button, the linear vibration motor is controlled to stop vibrating, thereby completing the vibration test to avoid accidents caused by continued vibration. The vibration resistance performance of the new energy vehicle bolt fastener can be judged by measuring the time interval from the start of the vibration test to the stop of vibration.

[0015] Compared with the prior art, the present invention provides a device and method for testing the vibration resistance of bolt fasteners for new energy vehicles, which has the following beneficial effects: (1) Multi-directional dynamic loading is achieved through three-dimensional independent vibration simulation technology. The three linear vibration motors combined with the 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 the traditional single-axis vibration test, this multi-degree-of-freedom coupled vibration mode can more realistically reflect the stress state of the bolts in actual working conditions, especially simulating the impact of complex working conditions such as steering bumps, acceleration and braking on fasteners, providing a test environment close to the real vehicle for the evaluation of the vibration resistance of the bolts; (2) By adopting the intelligent damping adjustment system of magnetorheological fluid, the rheological properties of magnetorheological fluid are dynamically controlled by electromagnets to achieve 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 of the magnetic field intensity, thereby accurately controlling the energy dissipation capacity 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 realize the endurance test of high damping steady-state vibration, greatly expanding the scene adaptability of the device; (3) A hydraulic amplification system driven by a magnetic dipole is used through a linkage mechanism. The micro-displacement is converted into hydraulic power through a conical disc-piston plate structure. When the bolt becomes slightly loose, the relative movement of the connecting ball and the conical groove triggers the movement of the piston plate. The principle of permanent magnet repulsion is used to drive the directional flow of hydraulic oil, forming a self-reinforced displacement amplification effect. In conjunction with the hydraulic circuit composed of a two-way one-way valve group, the tiny looseness is converted into a continuous upward displacement of the cross plate. This mechanical-hydraulic coupling design enables the device to have nano-level loosening detection sensitivity, which can capture micro-slip phenomena earlier than macro-loosening. (4) The visual monitoring system innovatively adopts a gradual optical warning mechanism, which realizes dynamic adjustment of the LED light source by sliding the conductive plate on the resistor bar. When the conductive plate is in a low position, the green light-emitting diode obtains a larger current share. As the displacement increases, it gradually turns to red dominance, forming a continuous color temperature transition from green to red. This police-like light warning system converts abstract displacement parameters into intuitive color codes. Testers can quickly judge the degree of bolt looseness through the change of light color. Compared with traditional digital instruments, it has a better on-site warning effect and is particularly suitable for rapid detection scenarios on production lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall three-dimensional structure of a vibration resistance testing device for bolt fasteners of new energy vehicles proposed by the present invention; Figure 2 This is a schematic cross-sectional view of a device for testing the vibration resistance of bolt fasteners for new energy vehicles proposed by the present invention; Figure 3 for Figure 2 A partial enlarged view of part A; Figure 4 for Figure 2 A partial enlarged view of part B; Figure 5 This is a partial three-dimensional structural diagram of a device for testing the vibration resistance of bolt fasteners for new energy vehicles proposed by the present invention; Figure 6 This is a schematic diagram of the three-dimensional structure of the vibration mechanism proposed in the present invention; Figure 7This is a schematic cross-sectional view of the locking mechanism proposed in the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of the connection mechanism proposed by the present invention; Figure 9 This is a schematic diagram of the three-dimensional structure of the linkage mechanism and monitoring and display mechanism proposed in the present invention; Figure 10 This is a schematic cross-sectional view of the linkage mechanism and monitoring and display mechanism proposed in the present invention; Figure 11 for Figure 10 A partial enlarged view of part C in the middle; Figure 12 for Figure 10 A partial enlarged view of part D in the middle; Figure 13 This is a schematic cross-sectional view of the linkage mechanism proposed in the present invention; Figure 14 This is a circuit diagram of the signal light proposed by the present invention.

[0017] In the figure: 1. Base; 101. Support plate; 2. Vibration mechanism; 201. Linear vibration motor; 202. Connecting column; 203. U-shaped claw; 204. Connecting plate; 3. Locking mechanism; 301. Fixing frame; 302. Partition; 303. Through hole; 304. First electromagnet; 305. Sealing plate; 306. Connecting rod; 307. Disc; 308. Round shell; 4. Connecting mechanism; 401. Sealing disc; 402. Control valve ; 403, connecting rod; 404, cylinder; 405, arc frame; 406, fixed 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 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, electric switch; 803, connecting pipe; 804, electric valve; 805, second hose; 806, first hose; 807, horizontal plate; 808, vertical rod; 809, connecting plate; 810, insulating rod; 811, movable conductive plate; 812, resistor strip; 813, lower plate; 814, upper plate; 815, touch button; 9, linkage mechanism ;901, sealing box; 902, piston plate; 903, first permanent magnet; 904, second permanent magnet; 905, liquid outlet pipe; 906, lower cross pipe; 907, first one-way valve; 908, liquid inlet pipe; 909, upper cross pipe; 910, second one-way valve; 911, cross bar; 912, conical disk; 913, connecting ball; 914, fixing rod; 10, bolt to be tested; 11, controller; 12, support frame; 13, high-speed camera. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0019] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0020] Reference Figure 1-14 A vibration resistance test device for bolt fasteners of 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. The front, right, and bottom sides of the vibration table 5 are each provided with a vibration mechanism 2. The vibration mechanism 2 includes: a linear vibration motor 201, a connecting column 202, and a connecting disk 204. A plurality of U-shaped claws 203 are fixedly mounted on the outer side of the connecting column 202, and the U-shaped claws 203 are movably sleeved on the outer side of the connecting disk 204. The left side, rear side, and bottom of the vibration table 5 are each provided with a locking mechanism 3. The locking mechanism 3 comprises a fixed frame 301, a sealing plate 305, a connecting rod 306, and a circular shell 308. A first electromagnet 304 and two partitions 302 are fixedly mounted within the fixed frame 301. Two through holes 303 are defined on one side of the partitions 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 one side of the top of the base 1 .

[0021] In this embodiment, the linkage mechanism 9 includes: a sealing box 901, a piston plate 902, a connecting ball 913, a conical disk 912, an upper cross tube 909 and a lower cross tube 906. A cross beam 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 disk 912. The connecting ball 913 movably abuts in the conical groove. A fixing rod 914 is fixedly installed between the connecting ball 913 and the lower test plate 7. A cross bar 911 is fixedly installed between the other side of the conical disk 912 and the piston plate 902. Both sides of the bottom of the sealed box 901 are connected to a liquid outlet pipe 905, a first one-way valve 907 is provided in the liquid outlet pipe 905, and the bottom end of the liquid outlet pipe 905 is connected to the lower horizontal pipe 906. Both sides of the top of the sealed box 901 are connected to a liquid inlet pipe 908, a second one-way valve 910 is provided in the liquid inlet pipe 908, and the top end of the liquid inlet pipe 908 is connected to the upper horizontal pipe 909; First permanent magnets 903 are fixedly mounted on both sides of the piston plate 902, and second permanent magnets 904 are fixedly mounted on both inner walls of the sealing box 901. The first permanent magnet 903 and the second permanent magnet 904 on the same side have opposite magnetic poles that repel each other.

[0022] In this embodiment, the monitoring and display mechanism 8 includes: an L-shaped box 801, a horizontal plate 807, a signal light 802, a resistance bar 812, and a movable conductive plate 811. The left side of the L-shaped box 801 is connected to a first hose 806 and a connecting pipe 803. The other end of the first hose 806 is connected to one end of the upper horizontal plate 807. The connecting pipe 803 is provided with an electrically controlled valve 804. 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 hose 805. The top end of the second hose 805 is connected to one end of the lower horizontal pipe 906. The horizontal plate 807 is slidably installed in the L-shaped box 801, and 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 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 bar 812. The top and bottom ends of the resistor bar 812 are respectively fixedly installed with an upper plate 814 and a lower plate 813. The upper plate 814 and the lower plate 813 are both fixedly installed on the right side of the L-shaped box 801.

[0023] In this embodiment, the signal light 802 includes: a lampshade 8024, a base 8021, a red LED 8022, and a green LED 8023. The lampshade 8024, the red LED 8022, and the green LED 8023 are fixedly mounted on the top of the base 8021, and the base 8021 is fixedly mounted 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 pole of the power supply 8025 is electrically connected to one end of the electric control switch 8026, the other end of the electric control switch 8026 is electrically connected to the movable conductive plate 811, the negative pole 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.

[0024] In this embodiment, a support rod 601 is fixedly installed between the upper test plate 6 and the vibration table 5, and multiple groups of connection mechanisms 4 are provided between the lower test plate 7 and the vibration table 5. The connection mechanism 4 includes: a connection rod 403, a sealing disk 401, a fixed disk 406 and a cylinder 404. The two ends of the connection rod 403 are fixedly connected to the sealing disk 401 and the cylinder 404 respectively. A plurality of arc frames 405 are fixedly installed on the top of the cylinder 404. The arc frame 405 is sleeved on the outer side of the fixed disk 406. The fixed disk 406 is fixedly installed on the bottom end of the lower test plate 7. A connecting hole 303 is opened on the top of the sealing disk 401, and a control valve 402 is provided in the connecting hole 303. A circular groove 501 and multiple sealing grooves 502 are provided at the bottom of the vibration table 5. A connecting hole 303 is provided between the circular groove 501 and the sealing groove 502. A second electromagnet 504 is fixedly installed on the top inner wall 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.

[0025] In this embodiment, a controller 11 and four support plates 101 are fixedly installed on the top of the base 1, wherein a support frame 12 is fixedly installed on the top of two support plates 101, a high-speed camera 13 is fixedly installed in the support frame 12, and 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 sensors 701 are arranged in multiple groups, and the bottom ends of the pressure sensors 701 are 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 circular shell 308 is sleeved on the outside of the disc 307, and the circular shell 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 . The model of the linear vibration motor 201 is JZD-LV-50.

[0026] The present invention also provides a method for testing the vibration resistance of bolt fasteners of new energy vehicles, which is applied to the above-mentioned device for testing the vibration resistance of bolt fasteners of new energy vehicles, and includes the following steps: S1: Screw the bolt 10 to be tested between the upper test plate 6 and the lower test plate 7, and tighten the bolt 10 to be tested so that the pressure sensor 701 monitors the preload force; 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 disk 204. The three linear vibration motors 201 cooperate to realize independent control of the vibration of the vibration table 5 in three directions, thereby simulating the vibration of the car during driving. 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 in the fixed frame 301, so that the magnetorheological fluid in the fixed frame 301 circulates back and forth in the through hole 303 of the partition 302, and can generate magnetism by controlling the corresponding first electromagnet 304 to be energized, and apply an external magnetic field 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 arranged along the direction of the magnetic field, so that each particle becomes a magnetic dipole. Adjacent particles generate strong attraction due to the anisotropy of magnetic poles, and the force far exceeds the Brownian motion disturbance. Driven by the magnetic attraction force, the polarized particles adsorb each other along the magnetic lines of force, connecting end to end to form a chain structure. Multiple chains are further bundled into a columnar or mesh structure. This structure wraps the carrier fluid in the mesh gaps, restricting its fluidity. After the microstructure is reorganized, the yield stress of the fluid (the minimum shear force required to destroy the structure) increases from the initial less than 1Pa to more than 50kPa. At this time, the fluid exhibits Bingham plastic behavior: it remains rigid below the critical shear force and flows when it exceeds it. The strength of the shear force is proportional to the square of the magnetic field strength. The fluidity of the magnetorheological fluid can be controlled by adjusting the current flowing through the first electromagnet 304, thereby adjusting the magnetic field strength, thereby adjusting the sliding resistance of the sealing plate 305 within the fixed frame 301, thereby adjusting the vibration damping of the vibration platform 5. The corresponding linear vibration motor 201 can be controlled to stop running, and the corresponding first electromagnet 304 can be controlled to increase the magnetic force to achieve vibration control of the vibration platform in two directions or a single direction, thereby simulating different usage environments. S3: Start the high-speed camera 13 to capture images of the bolt 10 to be tested, monitor the change of the preload force through the pressure sensor 701, and determine the looseness of the bolt 10 to be tested under vibration; S4. When the bolt 10 to be tested is slightly loosened, a small amount of relative movement occurs between the upper test plate 6 and the lower test plate 7, thereby causing relative movement between the connecting ball 913 and the sealing box 901, thereby driving the conical disk 912 to move through the contact between the connecting ball 913 and the conical disk 912, and the conical disk 912 drives the piston plate 902 to move in the sealing box 901 through the cross bar 911, so that the space on both sides of the piston plate 902 changes, and when the space becomes larger, the liquid above the transverse plate 807 in the L-shaped box 801 is input into the enlarged space through the first hose 806, the upper transverse tube 909 and the liquid inlet pipe 908. When the space becomes smaller, the excess water in the space enters the lower transverse plate 807 in the L-shaped box 801 through the liquid outlet pipe 905, the lower transverse tube 906 and the second hose 805, thereby driving the transverse plate 807 to move upward. The conduction directions of the first one-way valve 907 and the second one-way valve 910 are both from top to bottom, so that the upper test When relative vibration occurs between plate 6 and lower test plate 7, horizontal plate 807 is driven to continuously move upward. Horizontal plate 807 drives movable conductive plate 811 upward via vertical rod 808, connecting plate 809, and insulating rod 810, turning on electric switch 8026, energizing red LED 8022 and green LED 8023, which illuminate. When movable conductive plate 811 is at the bottom, the current flowing into green LED 8023 is much greater than the current flowing into red LED 8022, causing the light passing through lampshade 8024 to be 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. The color of the light emitted by lampshade 8024 changes from pure green to yellow-green to bright yellow to orange-yellow to orange-red to pure red, allowing the looseness to be determined by the color change. S5. When the conductive plate 811 moves to contact the touch button 815, the linear vibration motor 201 is controlled to stop vibrating, thereby completing the vibration resistance test, thereby avoiding accidents caused by continued vibration, and the vibration resistance performance of the new energy vehicle bolt fastener can be judged by measuring the time interval from the start of the vibration test to the stop of the vibration.

[0027] In this embodiment, multi-directional dynamic loading is achieved through three-dimensional independent vibration simulation technology. The three linear vibration motors 201 combined with the flexible connection structure of the U-shaped claw 203 can accurately control the independent vibration of the vibration table 5 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 the traditional single-axis vibration test, this multi-degree-of-freedom coupled vibration mode can more realistically reflect the stress state of the bolts in actual working conditions, especially it can simulate the impact of complex working conditions such as steering bumps, acceleration and braking on fasteners, providing a test environment close to the real vehicle for the evaluation of the vibration resistance of the bolts; by adopting The magnetorheological fluid intelligent damping adjustment system dynamically controls the rheological properties of the magnetorheological fluid through electromagnets to achieve 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 network structure, and its yield stress increases significantly with the square of the magnetic field intensity, thereby accurately controlling the energy dissipation scattering ability of the vibration system. This active damping adjustment mechanism can quickly switch the vibration mode according to the test requirements, and can simulate extreme road conditions with low damping and high amplitude, and realize endurance testing of high-damped steady-state vibration, greatly expanding the scene adaptability of the device; The hydraulic amplification system driven by magnetic dipoles is adopted in the linkage mechanism 9. The micro displacement is converted into hydraulic power through the conical disk 912-piston plate 902 structure. When the bolt is slightly loosened, the relative movement of the connecting ball 913 and the conical groove triggers the movement of the piston plate 902. The principle of permanent magnet repulsion is used to drive the directional flow of hydraulic oil, forming a self-reinforced displacement amplification effect. In conjunction with the hydraulic circuit composed of a two-way one-way valve group, the tiny looseness is converted into a continuous upward displacement of the cross plate 807. This mechanical-hydraulic coupling design gives the device nano-level loosening detection sensitivity, which can capture micro slippage earlier than macro loosening. The visual monitoring system innovatively adopts a gradual optical warning mechanism. By sliding the conductive plate 811 on the resistor bar 812, the LED light source is dynamically adjusted. When the conductive plate is in the low position, the green LED 8023 obtains a larger current share. As the displacement increases, it gradually turns to red, forming a continuous color temperature transition from green to red. This police-like light warning system converts abstract displacement parameters into intuitive color codes. Testers can quickly determine the degree of bolt loosening by the change in light color. Compared with traditional digital instruments, it has a more effective on-site warning effect and is particularly suitable for rapid detection scenarios on production lines. The standard parts used in the present invention can all be purchased from the market, and special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

Claims

1. A new energy vehicle bolt fastener vibration resistance test device, characterized in that: include: A base (1), a vibration table (5), an upper test plate (6) and a lower test plate (7), wherein the upper test plate (6) and the lower test plate (7) are connected via a bolt to be tested (10), and a vibration mechanism (2) is provided on the front side, the right side and the bottom of the vibration table (5), wherein the vibration mechanism (2) comprises: a linear vibration motor (201), a connecting column (202) and a connecting disk (204), wherein a plurality of U-shaped claws (203) are fixedly mounted on the outer side of the connecting column (202), and the U-shaped claws (203) are movably sleeved on the outer side of the connecting disk (204); The left side, rear side and bottom of the vibration table (5) are all provided with a locking mechanism (3), the locking mechanism (3) comprising: 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 provided on one side of the partition (302), and 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 display mechanism (8) is provided on one side of the top of the base (1).

2. The vibration resistance test device for bolt fasteners of new energy vehicles according to claim 1 is characterized in that: The linkage mechanism (9) comprises: a sealing box (901), a piston plate (902), a connecting ball (913), a conical disc (912), an upper transverse tube (909) and a lower transverse 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); and a crossbeam (911) is fixedly installed between the other side of the conical disc (912) and the piston plate (902); Both sides of the bottom of the sealed box (901) are connected to a liquid outlet pipe (905), a first one-way valve (907) is provided in the liquid outlet pipe (905), and the bottom end of the liquid outlet pipe (905) is connected to the lower transverse pipe (906). Both sides of the top of the sealed box (901) are connected to a liquid inlet pipe (908), a second one-way valve (910) is provided in the liquid inlet pipe (908), and the top end of the liquid inlet pipe (908) is connected to the upper transverse pipe (909); First permanent magnets (903) are fixedly mounted on both sides of the piston plate (902), and second permanent magnets (904) are fixedly mounted on both inner walls of the sealing box (901), with the first permanent magnet (903) and the second permanent magnet (904) on the same side having opposite magnetic poles that repel each other.

3. The vibration resistance test device for bolt fasteners of new energy vehicles according to claim 2, characterized in that: The monitoring and display mechanism (8) comprises: an L-shaped box (801), a horizontal plate (807), a signal light (802), a resistance bar (812) and a movable conductive plate (811); the left side of the L-shaped box (801) is connected to a first hose (806) and a connecting pipe (803); the other end of the first hose (806) is connected to one end of the upper 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 hose (805); the top end of the second hose (805) is connected to one end of the lower horizontal pipe (906); The horizontal plate (807) is slidably mounted in the L-shaped box (801), a vertical rod (808) is fixedly mounted on the top of the horizontal plate (807), an insulating rod (810) is fixedly mounted on the top of the movable conductive plate (811), and the top ends of the insulating rod (810) and the vertical rod (808) are fixedly mounted with the same connecting plate (809), the movable conductive plate (811) is slidably sleeved on the outside of the resistor bar (812), and the top and bottom ends of the resistor bar (812) are fixedly mounted with an upper plate (814) and a lower plate (813), respectively, and the upper plate (814) and the lower plate (813) are both fixedly mounted on the right side of the L-shaped box (801).

4. The vibration resistance test device for bolt fasteners of new energy vehicles according to claim 3 is characterized in that: The signal light (802) comprises: 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 mounted on the top of the base (8021); and the base (8021) is fixedly mounted 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 electrode of the power supply (8025) is electrically connected to one end of the electric control switch (8026), the other end of the electric control switch (8026) is electrically connected to the movable conductive plate (811), the negative electrode 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).

5. The vibration resistance test device for bolt fasteners of new energy vehicles according to claim 4, characterized in that: A support rod (601) is fixedly installed between the upper test plate (6) and the vibration table (5), and a plurality of connection mechanisms (4) are provided between the lower test plate (7) and the vibration table (5), wherein the connection mechanisms (4) include: a connection rod (403), a sealing disk (401), a fixed disk (406) and a cylinder (404), wherein both ends of the connection rod (403) are fixedly connected to the sealing disk (401) and the cylinder (404), respectively, and a plurality of arc frames (405) are fixedly installed on the top of the cylinder (404), wherein the arc frames (405) are sleeved on the outside of the fixed disk (406), and the fixed disk (406) is fixedly installed on the bottom end of the lower test plate (7), and a connecting hole (303) is provided on the top of the sealing disk (401), and a control valve (402) is provided in the connecting hole (303); A circular groove (501) and a plurality of sealing grooves (502) are provided at the bottom of the vibration table (5); a connecting hole (303) is provided between the circular groove (501) and the sealing groove (502); a second electromagnet (504) is fixedly mounted on the top inner wall of the circular groove (501); a piston disc (503) is slidably mounted inside the circular groove (501); the bottom end of the piston disc (503) is fixedly connected to the corresponding connecting disc (204); the sealing disc (401) is slidably mounted in the corresponding sealing groove (502); and the circular groove (501) and the sealing groove (502) are filled with magnetorheological fluid.

6. The vibration resistance test device for bolt fasteners of new energy vehicles according to claim 5, characterized in that: A controller (11) and four support plates (101) are fixedly mounted on the top of the base (1), wherein a support frame (12) is fixedly mounted on the top of two of the support plates (101), and a high-speed camera (13) is fixedly mounted inside the support frame (12). A pressure sensor (701) is provided between the upper test plate (6) and the lower test plate (7), and the pressure sensor (701) is connected to the controller (11) for signal transmission. The pressure sensors (701) are arranged in multiple groups, and the bottom ends of the pressure sensors (701) are 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 circular shell (308) is sleeved on the outside of the disc (307), and the circular shell (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.

7. A method for testing the vibration resistance of bolt fasteners of new energy vehicles, applied to the device for testing the vibration resistance of bolt fasteners of new energy vehicles according to claim 6, characterized in that: The following steps are involved: S1: screwing the bolt to be tested (10) between the upper test plate (6) and the lower test plate (7), and tightening the bolt to be tested (10) so that the pressure sensor (701) monitors the preload force; S2: The linear vibration motor (201) is started 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 disk (204). The vibration of the vibration table (5) in three directions is independently controlled by the cooperation of the three linear vibration motors (201), thereby simulating the vibration during the driving of the car. While the vibration table (5) is vibrating, the contact between the circular shell (308) and the circular disk (307) is realized. The connecting rod (306) and the sealing plate (305) are driven to slide in the fixed frame (301), so that the magnetorheological fluid in the fixed frame (301) circulates back and forth in the through hole (303) of the partition (302), and the magnetism can be generated by controlling the corresponding first electromagnet (304) to be energized, and 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 arranged along the direction of the magnetic field, so that each particle becomes a magnetic dipole, and adjacent particles are strongly attracted due to the anisotropy of the magnetic poles. The force is much greater than the disturbance force of Brownian motion. Driven by magnetic attraction, polarized particles adsorb each other along the direction of magnetic lines of force, connecting end to end to form a chain structure. Multiple chains are further bundled into a columnar or mesh structure. This structure wraps the carrier liquid in the grid gap, limiting its fluidity. After the microstructure is reorganized, the yield stress of the fluid (the minimum shear force required to destroy the structure) increases from the initial less than 1Pa to more than 50kPa. At this time, the fluid exhibits Bingham plastic behavior: it remains rigid below the critical shear force, and flows when it exceeds it. Its strength is related to the strength of the magnetic field. The magnetic field strength can be adjusted by adjusting the current of the first electromagnet (304), thereby controlling the fluidity of the magnetorheological fluid, thereby adjusting the sliding resistance of the sealing plate (305) in the fixed frame (301), so as to achieve the adjustment of the vibration damping of the vibration table (5), and the corresponding linear vibration motor (201) can be controlled to stop running, and the corresponding first electromagnet (304) can be controlled to increase the magnetic force, so as to achieve the vibration control of the vibration platform in two directions or in one direction, thereby simulating different use environments; S3: starting the high-speed camera (13), collecting an image of the bolt to be tested (10), monitoring the change of the pre-tightening force through the pressure sensor (701), and determining the looseness of the bolt to be tested (10) under vibration; S4. When the bolt (10) to be tested is slightly loosened, a small amount of relative movement occurs between the upper test plate (6) and the lower test plate (7), thereby causing relative movement between the connecting ball (913) and the sealing box (901). The conical disk (912) is driven to move by the contact between the connecting ball (913) and the conical disk (912). The conical disk (912) drives the piston plate (902) to move in the sealing box (901) through the cross bar (911), causing the space on both sides of the piston plate (902) to change, and the space between the piston plate (902) and the sealing box (901) is changed. When the space becomes larger, the liquid above the horizontal plate (807) in the L-shaped box (801) is input into the enlarged space through the first hose (806), the upper horizontal pipe (909) and the liquid inlet pipe (908). When the space becomes smaller, the excess water in the space enters the lower part of the horizontal plate (807) in the L-shaped box (801) through the liquid outlet pipe (905), the lower horizontal pipe (906) and the second hose (805), thereby driving the horizontal plate (807) to move upward. The conduction direction of the first one-way valve (907) and the second one-way valve (910) are both from top to bottom. Thus, when the upper test plate (6) and the lower test plate (7) vibrate relative to each other, the horizontal plate (807) is driven to continuously move upwards. The horizontal plate (807) drives the movable conductive plate (811) to move upwards through the vertical rod (808), the connecting plate (809) and the insulating rod (810), and the electric control switch (8026) is turned on, so that the red light-emitting diode (8022) and the green light-emitting diode (8023) are energized and light is generated. When the movable conductive plate (811) is at the bottom, the current in the green light-emitting diode (8023) is passed. The current flowing through the lampshade (8024) is much greater than the current flowing through the red light-emitting diode (8022), so that the light passing through the lampshade (8024) is green. As the movable conductive plate (811) moves upward, the current flowing through the green light-emitting diode (8023) gradually decreases, and the current flowing through the red light-emitting diode (8022) gradually increases, so that the green light gradually becomes darker and the red light gradually becomes stronger, so that the color of the light emitted by the lampshade (8024) changes from pure green → yellow-green → bright yellow → orange-yellow → orange-red → pure red, so that the looseness condition can be judged by the color change; S5. When the movable conductive plate (811) moves to contact the touch button (815), all the linear vibration motors (201) are controlled to stop vibrating, thereby completing the vibration resistance test, thereby avoiding accidents caused by continued vibration, and the vibration resistance performance of the new energy vehicle bolt fastener can be judged by measuring the time interval from the start of the vibration test to the stop of the vibration.

Images