Dry clutch vibration characteristic test device and method

Abstract

The invention provides a dry clutch vibration characteristic testing device and method, and relates to the field of vehicle transmission system testing. Comprising a base; the driving unit is arranged on the base and used for providing rotation driving force and driving at least one friction element to rotate. The adjustable boundary unit comprises a first boundary and a second boundary which are oppositely arranged on the base, and the axial distance between the first boundary and the second boundary is adjustable. The first boundary and the second boundary are correspondingly arranged outside the friction element in a covering manner, clamp at least one steel sheet and keep the steel sheet static in the test process; the excitation unit is used for applying controllable mechanical excitation to the friction element and / or the steel sheet; and the observation unit is arranged on the adjustable boundary unit or the base and is used for acquiring relative motion information between the friction element and the steel sheet in the test process. The test requirements of different numbers of friction plates / steel plates can be met, gaps between the plates can be adjusted, various clutch structure parameters and working conditions can be flexibly simulated, and the internal motion state can be directly observed.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission system testing, and more specifically, to a testing device and method for the vibration characteristics of a dry clutch. Background Technology

[0002] The clutch is a core component of the transmission system in high-speed tracked vehicles and other similar vehicles. Abnormal movements of its internal friction pairs (friction plates and steel plates) during operation, such as axial swaying and collisions, are one of the key causes of abnormal vibration and noise in the transmission system. In-depth research into these vibration mechanisms is crucial for improving the reliability, smoothness, and NVH performance of the transmission system.

[0003] However, clutches are enclosed structures in actual operation, making it difficult to directly observe the motion of their internal friction components. Current research on clutch vibration characteristics largely relies on vibration signals collected by sensors mounted outside the housing, followed by algorithmic inference of the internal state, essentially treating the oscillation-collision process of the friction pair as a "black box." This method has significant limitations: First, the boundary conditions (such as axial limiting clearance and the number of friction plates) of most existing test benches are fixed, making it impossible to flexibly adjust them to systematically study the influence of different structural parameters (such as the number of plates and clearance) on vibration characteristics; second, the applied excitation forms are relatively simple, making it difficult to accurately simulate the complex and varied internal and external excitation load spectra in actual working conditions; finally, the lack of direct observation methods of the internal motion state makes it difficult to establish an intuitive and reliable verification relationship between experimental data and theoretical models and simulation analyses, limiting the depth of mechanistic explanation.

[0004] Although there are solutions that use transparent enclosures for observation, their structural strength and load-bearing capacity are limited, making it difficult to simulate real-world load conditions, and they usually lack the ability to adjust key structural parameters. Summary of the Invention

[0005] The purpose of this invention is to provide a test device and method for the vibration characteristics of a dry clutch, which can flexibly simulate various clutch structural parameters and working conditions, and can also realize direct observation of the internal motion state. It can provide high-quality data sources and intuitive analysis methods for the study of the sway-collision mechanism of clutch friction elements, and the calibration and verification of dynamic models.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A vibration characteristic testing device for a dry clutch, used to perform a shimmy-impact test on the friction elements inside the clutch, comprising: Base; A drive unit, disposed on the base, is used to provide rotational driving force and drive at least one of the friction elements to rotate; An adjustable boundary unit includes a first boundary and a second boundary that are disposed opposite to each other on the base and whose axial spacing is adjustable; the first boundary and the second boundary are respectively covered on the outside of the friction element and clamp at least one steel sheet that is axially spaced from the friction element, and keep the steel sheet stationary during the test; An excitation unit is used to apply a controllable mechanical excitation to the friction element and / or the steel sheet; An observation unit, located on the adjustable boundary unit or the base, is used to acquire relative motion information between the friction element and the steel sheet during the test.

[0007] Furthermore, the first boundary includes a first substrate with a central hole and a plurality of extension arms extending axially from one side of the first substrate. The plurality of extension arms are distributed circumferentially at intervals to jointly enclose a clamping space for clamping the steel sheet; and the first substrate is provided with a first mounting portion for connecting with the base. The second boundary includes a second base plate with a central hole, and the second base plate is provided with a plurality of limiting structures in the circumferential direction for lateral constraint and support of the extension arm when it is extended; the second base plate is provided with a second mounting part for sliding connection with the base.

[0008] Furthermore, the multiple extension arms are arranged in parallel, and the gap between adjacent extension arms forms a clamping gap for clamping the partial protrusion of the steel sheet; The limiting structure is a limiting block protruding from the second substrate, and multiple limiting blocks are fitted into multiple clamping gaps in a one-to-one correspondence.

[0009] Furthermore, there are two first mounting portions, located on the radial sides of the first substrate respectively; there are two second mounting portions, located on the radial sides of the second substrate respectively; and both the first mounting portion and the second mounting portion are provided with an adjustment elongated hole extending along the length direction of the base. The base has a U-shaped cross-section, and its open end face has a plurality of fixing positions arranged along its length; the fastener passes through the adjustment elongated hole and can be selectively locked with any of the fixing positions to fix the distance between the first boundary and the second boundary.

[0010] Furthermore, the first substrate and the second substrate are polygonal, and the plurality of the extended arms are respectively disposed on each edge of the first substrate; the plurality of the limiting blocks are correspondingly disposed on each edge of the second substrate and protrude radially from their edges.

[0011] Furthermore, the drive unit includes a motor, a splined shaft, and a coupling. The splined shaft is used to mount the friction element, and the motor drives the splined shaft to rotate through the coupling.

[0012] Furthermore, the excitation unit includes an air compressor, a solenoid valve, and a nozzle. The solenoid valve is connected to a controller and is used to control the nozzle to apply pulsed gas excitation to the friction element according to a preset program. Multiple nozzles are provided and point to different positions of the friction element in the circumferential or axial direction.

[0013] Furthermore, the observation unit includes an observation window formed by the first boundary and / or the second boundary, and / or a high-speed camera device disposed on the base.

[0014] Furthermore, it also includes a vibration sensor installed on the second boundary or base for collecting vibration signals generated by the collision between the friction element and the boundary.

[0015] A test method based on the aforementioned dry clutch vibration characteristic test device includes the following steps: The number of friction elements and the gap between the plates were determined according to the test plan. The friction elements were installed on the drive unit, and the steel plates were installed on the adjustable boundary unit and the distance between the first boundary and the second boundary was adjusted. The drive unit is started to rotate the friction element at a set speed, and the excitation unit is controlled to apply external excitation to the friction element according to the set excitation parameters; The vibration signal generated by the interaction between the friction element and the adjustable boundary unit is acquired by the acquisition unit, and visual or physical field information reflecting the relative motion between the friction element and the steel sheet is obtained by the observation unit. Based on the collected experimental data, the parameters of the dynamic model reflecting the clutch shimmy-collision behavior were calibrated and verified, and vibration characteristic simulation and mechanism analysis were performed based on the verified model.

[0016] The present invention has at least the following advantages or beneficial effects: This invention utilizes an adjustable boundary unit composed of a first and second boundary with adjustable axial spacing. This allows for flexible adaptation to combinations of friction elements and steel plates with varying numbers, thicknesses, and arrangements. It also precisely sets the inter-plate gap and axial boundary distance, enabling a systematic study of the influence of clutch structural parameters on vibration characteristics. This addresses the problem of fixed boundary conditions in existing test devices, which prevent parametric comparison studies. By clamping the steel plates between the first and second boundaries and keeping them stationary during the test, while the friction elements are rotated by a drive unit, the invention accurately simulates the real working state of a dry clutch under disengagement conditions, where a relative speed difference exists between the friction pairs. This provides a basis for studying the oscillation and collision behavior induced by relative motion. This invention provides an accurate foundation for simulating operating conditions. By setting up an excitation unit to apply controllable mechanical excitation to the friction elements and / or steel plates, it can simulate the complex and varied internal and external excitation loads in actual transmission systems and achieve independent programmable control of the excitation frequency, amplitude, waveform, and point of application. This allows for the study of the mechanism by which different excitation characteristics affect the vibration response of the clutch, breaking through the limitations of the single form of traditional experimental excitation. By setting up an observation unit on the adjustable boundary unit or base, it is possible to directly acquire visual or physical field information of the relative motion between the friction elements and steel plates, transforming the invisible black box process inside the clutch into a directly observable and recordable process. This provides crucial direct evidence for intuitively understanding nonlinear collision dynamics and verifying theoretical models. This application integrates the aforementioned adjustable boundary unit, drive unit, excitation unit, and observation unit onto the same base to form an integrated experimental device. It enables collaborative testing on a single platform with adjustable boundary conditions, controllable operating condition excitation, visible internal state, and measurable vibration signals. This provides a highly integrated, parameterized, and reliable comprehensive experimental solution for the study of clutch vibration mechanisms, calibration, and verification of dynamic models. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the overall structure of the dry clutch vibration characteristic testing device provided in the application embodiment; Figure 2 A schematic diagram of the adjustable boundary element provided in the application embodiment; Figure 3 A schematic diagram of the first boundary structure provided for the application embodiment; Figure 4 A schematic diagram of the second boundary structure provided for the application embodiment; Figure 5 This is a flowchart of the oscillation-collision simulation of a single friction element in the application embodiment; Figure 6 A comparison chart of experimental and simulated signals of deformed and flat plates at a rotation speed of 500 r / min for the embodiments of the application; Figure 7 A comparison chart of experimental and simulated signals of deformed and flat plates at a rotation speed of 1000 r / min for the application embodiment; Figure 8 A comparison chart of experimental and simulated signals of deformed and flat plates at a rotation speed of 1500 r / min for the application embodiment; Figure 9 A comparison chart of experimental and simulated signals of deformed and flat plates at a rotational speed of 2000 r / min for the embodiments of the application; Figure 10 This is a comparison chart of the test signals and simulation signals of the deformed and flat plates after normalization at a rotation speed of 500 r / min, as shown in the embodiment of the application. Figure 11 This is a comparison chart of the test signals and simulation signals of the deformed and flat plates in the application embodiment after normalization at a speed of 2000 r / min; Figure 12 A comparison diagram of the axial displacement of the deformable sheet and the flat sheet in the application embodiment under the conditions of disturbance force 0.5N, frequency 1Hz, and gap 10 mm; Figure 13 A comparison diagram of the oscillation torque of the deformable sheet and the flat sheet in the application embodiment under the conditions of disturbance force 0.5N, frequency 1Hz, and gap 10 mm; Figure 14 Comparison of axial projections of deformable and flat sheets in the application embodiment under the conditions of disturbance force 0.5N, frequency 1Hz, and gap 10 mm; Figure 15 A comparison diagram of the axial displacement of the deformable sheet and the flat sheet in the embodiment of the application under the conditions of disturbance force 0.5N, frequency 0.5Hz, and gap 10 mm; Figure 16 A comparison diagram of the oscillation torque of the deformable sheet and the flat sheet in the application embodiment under the conditions of disturbance force 0.5N, frequency 0.5Hz, and gap 10 mm; Figure 17 Comparison of axial projections of deformable and flat sheets in the application embodiment under the conditions of disturbance force 0.5N, frequency 0.5Hz, and gap 10 mm; Figure 18 A comparison diagram of the axial displacement of the deformable sheet and the flat sheet in the application embodiment under the conditions of disturbance force 0.5N, frequency 2Hz, and gap 10 mm; Figure 19A comparison diagram of the oscillation torque of the deformable sheet and the flat sheet in the embodiment of the application under the conditions of disturbance force 0.5N, frequency 2Hz and gap 10 mm; Figure 20 This is a comparison of the axial projections of the deformable sheet and the flat sheet in the application embodiment under the conditions of disturbance force 0.5N, frequency 2Hz, and gap 10 mm.

[0019] Reference numerals: 1-base; 2-motor; 3-coupling; 4-spline shaft; 5-friction element; 6-steel sheet; 7-first boundary; 71-first base plate; 72-extended arm; 73-first mounting part; 74-clamping gap; 8-second boundary; 81-second base plate; 82-limiting block; 83-second mounting part; 9-air compressor; 10-fixed position. Detailed Implementation Example

[0020] Please refer to Figures 1-4 The figure shown is a schematic diagram of the overall structure of the dry clutch vibration characteristic test device in an embodiment of the present invention. This embodiment provides a test device for the vibration characteristics of a dry clutch. The device includes a base 1 and a drive unit, an adjustable boundary unit, an excitation unit, and an observation unit disposed thereon. The drive unit is used to provide rotational driving force and drive at least one friction element 5 to rotate at a set speed.

[0021] In this embodiment, the drive unit adopts an axial arrangement structure, including an adjustable-speed motor 2, a coupling 3, and a splined shaft 4. The motor 2 is fixed to the open end face of the base 1 via a motor mount, and its output shaft is connected to the splined shaft 4 via the coupling 3. Only friction elements 5 are installed on the splined shaft 4, and one or more friction elements 5 (i.e., friction plates) can be installed. The motor 2 drives the splined shaft 4 to rotate, thereby driving the friction plates to rotate at a set speed, simulating the input of the active part, and is used to carry out oscillation-collision tests of friction elements 5 under single or multiple plate conditions and different gaps.

[0022] The aforementioned adjustable boundary unit includes a first boundary 7 and a second boundary 8, which are axially opposite to each other on the base 1, and their axial spacing can be flexibly and reliably adjusted according to test requirements. The first boundary 7 and the second boundary 8 are respectively covered outside the friction element 5, and clamp at least one steel plate 6 axially spaced from the friction element 5, keeping the steel plate 6 stationary during the test, thus allowing the friction plate to rotate while the steel plate 6 remains stationary. This design allows for precise control of the friction plate's rotational speed, simulating the actual speed difference between the driving and driven parts of the clutch, providing a foundation for studying the influence of rotational speed on oscillation behavior.

[0023] As an example, the first boundary 7 may include a first base plate 71 with a central opening and a plurality of elongated arms 72 extending axially from one side toward the second boundary 8. The first base plate 71 with the central opening allows the spline shaft 4 to pass through. The plurality of elongated arms 72 are distributed circumferentially to form a clamping space for clamping the steel plate 6. The second boundary 8 includes a second base plate 81 with a central opening and a plurality of limiting structures circumferentially provided for lateral constraint and support when the elongated arms 72 are extended. By adjusting the relative positions of the first boundary 7 and the second boundary 8 on the base 1, the axial distance between them can be changed, thereby adapting to different combinations of the number of friction plates and steel plates 6, and precisely setting the gaps between the plates and between the friction plates and the boundary. This allows researchers to systematically study the effects of the number of plates and the gap on the vibration characteristics of the clutch, greatly expanding the dimension and depth of experimental research.

[0024] Specifically, multiple extendable arms 72 are arranged in parallel, and the gaps between adjacent extendable arms 72 form clamping gaps 74 for clamping the local protrusions (outer peripheral lugs) of the steel sheet 6. The limiting structure of the second boundary 8 is a limiting block 82 protruding from the second base plate 81, and multiple limiting blocks 82 are fitted into multiple clamping gaps 74 in a one-to-one correspondence. Through the above structure, on the one hand, the combination of the first boundary 7 and the second boundary 8 can reliably clamp the outer spline steel sheet 6, so that the steel sheet 6 remains stably positioned during the test, thereby forming the required relative motion relationship with the friction plate that rotates with the spline shaft 4, accurately reproducing the relative motion relationship under the clutch disengagement condition; on the other hand, when the first boundary 7 and the second boundary 8 are close together, the mutual fitting of the limiting block 82 and the extendable arm 72 forms a mutually supporting frame structure, which significantly improves the stiffness and stability of the entire boundary unit when subjected to axial impact force, avoids deformation caused by excessive length of the extendable arm 72, and ensures that the test conditions are consistent and the results are comparable.

[0025] As an example, the first substrate 71 is provided with a first mounting portion 73 for connecting to the base 1, and the second substrate 81 is provided with a second mounting portion 83 for sliding connection to the base 1. Two first mounting portions 73 are provided, located on opposite radial sides of the first substrate 71; two second mounting portions 83 are provided, located on opposite radial sides of the second substrate 81; and both the first mounting portion 73 and the second mounting portion 83 are provided with an adjustment elongated hole extending along the length of the base 1. The base 1 has a U-shaped cross-section, allowing the boundary unit and friction element 5 to sink into its opening slot; by providing multiple fixing positions 10 (such as fixing slots) on the U-shaped top surface of the base 1, fasteners (such as bolts) are used for locking. The fasteners pass through the adjustment elongated holes and can selectively lock with any fixing position 10 to fix the distance between the first boundary 7 and the second boundary 8. This structure achieves stepless or stepped adjustment of the distance between the first boundary 7 and the second boundary 8 and ensures the stability of the structure after adjustment.

[0026] In one specific embodiment, the first substrate 71 and the second substrate 81 are polygonal, preferably quadrilateral, with four sets of extendable arms 72 respectively located on the four edges of the first substrate 71. Two extendable arms 72 in each set are spaced apart to form a clamping gap 74. Multiple limiting blocks 82 are correspondingly disposed on the four edges of the second substrate 81 and protrude radially from their edges. In this way, a stable adjustable spacing structure is formed around the first boundary 7 and the second boundary 8, improving the stability of the testing process.

[0027] In this embodiment of the application, the excitation unit is used to simulate various excitations acting on the clutch under actual working conditions.

[0028] As an example, the aforementioned excitation unit includes an air compressor 9, a solenoid valve, and nozzles. The solenoid valve is connected to a controller to control the nozzles to apply pulsed gas excitation to the friction element 5 according to a preset program. Specifically, the air compressor 9 is installed at one end of the first boundary 7 and connected to the solenoid valve via a hose. The outlet of the solenoid valve is connected to multiple nozzles via a distributor. By programming the solenoid valve to control its opening and closing timing and duty cycle, pulsed gas excitations of different frequencies, amplitudes, and waveforms (such as square waves, sine waves, and random waves) can be precisely generated and applied to specific positions on the friction plate through the nozzles. Multiple nozzles are provided and point to different positions circumferentially or axially on the friction element 5. For example, they can be inserted through through holes opened circumferentially on the first substrate 71 to point towards the edge of the friction element 5. Nozzles can also be provided at different positions and in different directions to achieve single-point, multi-point, or different-directional excitation combinations, enabling the device to simulate everything from simple periodic excitations to complex random load spectra.

[0029] In this embodiment, the observation unit is disposed on the adjustable boundary unit or the base 1, and is used to obtain the relative motion information between the friction element 5 and the steel sheet 6 during the test.

[0030] As an example, the aforementioned observation unit may include an observation window formed by the first boundary 7 and / or the second boundary 8, for example, the space reserved in the frame structure itself composed of the extendable arm 72 and the limiting block 82; and / or a high-speed camera device mounted on the base 1, enabling researchers to directly observe or record the oscillation angle, axial displacement, and collision moments with the boundary or steel plate 6 of the friction plate during rotation via high-speed photography. This changes the traditional research model that relies on external signals to infer the internal state, transforming the internal oscillation phenomenon of the clutch from a "black box" analysis to an "observable and quantifiable" experimental research process, thereby enabling a more intuitive understanding of complex nonlinear collision dynamics.

[0031] In this embodiment, the device further includes a vibration sensor, such as an accelerometer, for acquiring vibration signals generated by the collision between the friction element 5 and the boundary. It is typically preferably mounted on the second boundary 8, which bears the direct impact, to synchronously acquire the vibration signals generated by the collision. Thus, this device can simultaneously acquire intuitive motion image information and precise vibration time-domain / frequency-domain information during the oscillation-collision process. The synchronous comparison and fusion analysis of these two types of data greatly enhances the credibility and richness of the mechanism research.

[0032] This application also provides a testing method based on the above-described device, comprising the following steps: The number of friction elements and the gap between the plates were determined according to the test plan. The friction elements were installed on the drive unit, and the steel plates were installed on the adjustable boundary unit and the distance between the first boundary and the second boundary was adjusted. The drive unit is started to make the friction element rotate at a set speed, and the excitation unit is controlled to apply external excitation to the friction element according to the set excitation parameters; The vibration signal generated by the interaction between the friction element and the adjustable boundary element is collected by the acquisition unit, and the visual or physical field information reflecting the relative motion between the friction element and the steel sheet is obtained by the observation unit. Based on the collected experimental data, the parameters of the dynamic model reflecting the clutch shimmy-collision behavior were calibrated and verified, and vibration characteristic simulation and mechanism analysis were performed based on the verified model.

[0033] This method systematizes the research process using this device: first, parameter settings (gap, number of plates) are performed; then, experiments are run under controllable rotational speed and excitation, while simultaneously acquiring visual information and vibration signals; finally, the high-quality, multi-dimensional experimental data collected is used to calibrate and verify the pre-established clutch shimmy-collision dynamics model. Once the model is experimentally verified, its credibility is greatly enhanced, and researchers can use this verified model to conduct extensive simulations and systematically analyze the influence of numerous parameters, such as friction plate deformation, different excitation frequencies, and different rotational speeds, on vibration characteristics, thereby revealing its underlying mechanisms in depth.

[0034] The present invention will be further described below with reference to a specific embodiment, but the scope of protection of the present invention is not limited thereto.

[0035] Two types of single-piece friction elements (flat and deformable) were tested at four different rotational speeds: 500 r / min, 1000 r / min, 1500 r / min, and 2000 r / min, to simulate a speed difference from low to high. The maximum oscillation angle of the friction element and the deformation angle of the deformable piece were obtained through actual measurement. The gap between the two boundaries was 10 mm, and the initial position of the friction element was the midpoint between the boundaries. At the start of the test, the motor was started and adjusted to the set speed. After the speed stabilized, the air compressor was turned on to allow airflow to impact the friction element, and then the sensor was turned on to collect vibration signals. The above operation was repeated once at each rotational speed. After the results of all rotational speeds were collected, the test object was replaced. The pulse airflow provided by the air compressor during the test was approximately 0.5 N. After starting, each impact lasted for 0.5 s and then stopped, with a cycle of 1 s. The B&K accelerometer used had a sampling frequency of 65536 Hz, and five impact responses were recorded at the same rotational speed, with a total duration of 5 s.

[0036] Based on the aforementioned controllable experimental conditions, the shimmy and vibration data obtained by this invention were used to establish and calibrate the shimmy-collision dynamics model of the clutch friction element. Simultaneously, after the experiment was completed, numerical simulations were performed on the experimental content. Detailed experimental and simulation parameters are shown in Table 1 below:

[0037] The specific process is as follows: Figure 2As shown, the turntable is the friction element of this application. At the start of the simulation, the preset operating parameters and the initial state of the friction element are substituted into the oscillation-collision dynamics model. The model calculates the spline force, centrifugal force for centering, and impact force from the air compressor acting on the friction element at the current moment. Substituting these external forces into the rigid body rotation equation, the angular acceleration and angular velocity of the friction element's oscillation, as well as the axial acceleration and velocity, are obtained. Then, using the Euler equation of motion, the Euler angular rate at the current moment is obtained; integrating the Euler angular rate yields the Euler angle and Euler rotation matrix for the next time step. The coordinates of each mass point of the friction element are calculated based on the new spatial pose to determine if any mass point collides with the boundary. If there is no collision, the collision force is zero; if there is a collision, the calculated collision force is substituted into the new round of calculation along with other external forces. The above steps are repeated until the set simulation duration of 5 seconds is reached, with the time step set to 5e-5 seconds. Numerical calculations are performed using the ode8 solver.

[0038] Then, under the same gap and excitation conditions, the output of the simulation model is compared with the experimental data, such as... Figures 6-9 The figures shown are schematic diagrams comparing the signals of a single deformable sheet and a flat sheet at rotational speeds of 500 r / min, 1000 r / min, 1500 r / min, and 2000 r / min.

[0039] It should be noted that because the simulation and the original experimental signals differ in amplitude, direct comparison is not convenient. To bring them to the same scale, the signals first need to be normalized. The specific method is as follows: In the formula, X represents the original data, and Y represents the normalized data. max and Y min The range of normalized data is defined, here set to [0 1]. Using this method, all signals are normalized, and normalized signals with the same rotational speed and deformation degree are plotted together to compare simulation results. Simulation results are similar at different rotational speeds; here, the lowest rotational speed of 500 r / min is selected. Figure 10 As shown, the maximum speed is 2000 r / min Figure 11 The comparison chart shown is used for illustration.

[0040] from Figure 10 and Figure 11 As can be seen from the data, at 500 r / min, the duration of each vibration signal segment in the deformable plate system is longer. Given that the duration of each excitation force is 0.5 s, the flat plate almost immediately stops colliding with the boundary, but the collision in the deformable plate system continues for a period of time. (Comparison) Figure 11It can be seen that when the rotational speed increases to 2000 r / min, the oscillation collision signal is "narrower" and sharper, while at low speed the signal is "wider". This indicates that the recovery time of a single collision at low speed is longer and the energy of each collision is more uniform, while collisions at high speed will produce more peaks.

[0041] After the model is verified through experiments, the dynamic model can be used to perform system simulations on different friction element states (e.g., flat and deformable plates), different gaps, and different excitation conditions, thereby analyzing some mechanistic differences in vibration characteristics. For example, when deformable and flat plates are subjected to different disturbance frequencies and rotational speeds, their shimmy characteristics will differ. Below, we select disturbance frequency, disturbance magnitude, and boundary clearance as variables to study their effects on shimmy-collision behavior. By plotting the axial displacement of the friction element, the shimmy disturbance torque, and the right-side axis projection, we compare the influence of different parameters on the shimmy-collision behavior of a single-pair system before and after deformation. The simulation parameters for each group are shown in Table 2 below.

[0042] During the process, the simulation results of the experimental parameters were selected as the baseline working condition (disturbance frequency of 1 Hz, disturbance force of 0.5 N, and boundary clearance of 10 mm). The axial displacement diagrams, oscillation torque diagrams, and shaft center trajectory diagrams of the flat and deformable plates at low speeds (500 r / min) and high speeds (2000 r / min) are shown below. Figures 12-14 As shown in the figure. In the simulation, the left and right boundary positions are -5 mm and 5 mm, respectively, and the initial position of the friction element is set in the middle.

[0043] from Figure 12The displacement diagram shows that the axial displacement of the friction element only changes significantly during the period of disturbance. Once the excitation stops, the friction element bounces off the right boundary after colliding with it and quickly comes to rest, maintaining its displacement until the next excitation cycle. This phenomenon indicates that in a single-pair system, the collision between the friction element and the boundary is mainly caused by the "push" of the disturbance. After the disturbance disappears, both the flat and deformable pieces gradually tend to a stable position where no collision occurs. Furthermore, the thrust generated by the excitation and the resulting oscillation-collision intensity are significantly affected by the rotational speed. At low speeds, the axial response of the friction element is relatively gentle and the displacement amplitude is small. The flat piece mainly fluctuates slightly near the right boundary, while the displacement of the deformable piece is affected by deformation and moves away from the boundary. The 5° deformable piece is concentrated in the 1~3 mm range, while the 10° deformable piece is in the 0~2 mm range, both exhibiting a certain periodicity. This also indicates that the system's oscillation energy is low at low speeds, and the rebound force is insufficient to significantly change the element's position. When the rotational speed increases to 2000 r / min, the system response shows a significant enhancement. The displacement of the flat plate is mainly concentrated in the range of 2-4.5 mm, with some displacements even exceeding the centerline. The displacement range of the deformable plate varies more widely, and the nonlinear characteristics of the system are significantly enhanced, especially for the 5° deformable plate, which expands to -4 to 3 mm. While the displacement intensity of the 10° deformable plate decreases, it still reaches -3 to 2 mm. In comparison, the oscillation-collision displacement of the deformable plate becomes more unstable at high speeds. This is because the increased geometric deformation caused by the deformation increases the probability of collision. Furthermore, the displacement response of the friction element between adjacent excitation cycles at high speeds is not completely consistent. Even with the same initial conditions, the motion trajectories of the friction element are not identical, indicating that the oscillation-collision process has strong randomness.

[0044] Figure 13 The variation of the oscillation disturbance torque of the friction element over time under different conditions is shown. Overall, the oscillation torque is highly correlated with axial collision behavior, concentrated during the period of disturbance force application. Once the excitation ends, the system quickly stabilizes, and the disturbance torque rapidly decays to near zero. At low speeds, the disturbance torque generated by the deformable plate is generally higher than that of the flat plate, with the fluctuation range of the 5° deformable plate reaching ±0.4 N·m, while the flat plate exhibits smaller fluctuations and lower overall energy. Upon entering the high-speed stage, the flat plate shows an increase, but the maximum does not exceed 0.1 N·m, while the 5° deformable plate reaches ±0.5 N·m.

[0045] Figure 14 The image shows the axial projection trajectory of the friction element when viewed from the right. Due to the strong nonlinear characteristics of oscillation, the axial trajectory of the friction element exhibits a relatively complex curved shape. Generally, at low speeds, the trajectories of each pair are curved, and the movement of each pair's trajectory is relatively slow; at high speeds, the projection has concentrated intervals, and is more dense, indicating greater energy.

[0046] Besides the disturbances during the depressurization process, other external excitations may also affect the friction elements, causing the disturbance frequency to fluctuate around 1 Hz. To analyze the effect of the excitation frequency on the oscillation-impact characteristics, the response results at 0.5 Hz and 2 Hz are plotted, as shown below. Figure 15 and Figure 20 and benchmark group Figures 12-14 Conduct a comparative analysis.

[0047] From a macroscopic perspective, the excitation frequency primarily affects the number of collisions between the friction element and the boundary per unit time. Especially at low speeds (500 r / min), the amplitude of a single collision at different frequencies does not vary significantly, and the displacement consistently exhibits micro-motion characteristics near the boundary. Furthermore, the amplitudes of the oscillation disturbance torque corresponding to different frequencies at low speeds are relatively concentrated and close, roughly within ±0.1 N·m, with only a few moments showing peak values ​​exceeding ±0.3 N·m for the two deformable plates. This indicates that the excitation frequency has a limited impact on the intensity of the disturbance torque at low speeds. Additionally, projections from the two axes show that the overall contours of the deformable and flat plates are very similar at different frequencies, with the deformable plate trajectory being denser only under high-frequency excitation. However, as the rotational speed increases, the combined effect of the excitation frequency and rotational speed increases the intensity of the friction element displacement. At high speeds with low-frequency excitation, the response of a 5° deformation is significantly greater than that of the flat plate, with displacement exceeding -4 mm and torque exceeding 0.5 N·m. At high frequencies, the displacement of the flat plate also increases to -4~4 mm, and the torque corresponding to the three friction elements also increases accordingly.

[0048] In general, the excitation frequency has a limited effect on the oscillation-collision of a single pair at low speeds; however, at high speeds, the excitation frequency and deformation are superimposed, significantly enhancing the nonlinear characteristics of the system and leading to a more severe and complex response.

[0049] This invention achieves flexible configuration of experimental structural parameters through adjustable boundary elements, accurate reproduction of the load spectrum through programmable excitation elements, visualization of the internal motion state through observation elements, and fusion of multi-source information through synchronous data acquisition. Ultimately, the device produces high-quality, comparable experimental data, providing a reliable basis for the calibration and verification of the dynamic model, and forming a complete solution for studying clutch vibration characteristics, from experiment to theory, and from phenomena to mechanisms. This device and method are particularly suitable for studying the effects of friction plate deformation, inter-plate clearance, and multi-plate coupling effects on clutch vibration and noise, and have significant engineering application and academic research value.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vibration characteristic testing device for a dry clutch, used to perform a shimmy-impact test on the friction elements inside the clutch, characterized in that, include: Base; A drive unit, disposed on the base, is used to provide rotational driving force and drive at least one of the friction elements to rotate; An adjustable boundary unit includes a first boundary and a second boundary that are disposed opposite to each other on the base and whose axial spacing is adjustable; the first boundary and the second boundary are respectively covered on the outside of the friction element and clamp at least one steel sheet that is axially spaced from the friction element, and keep the steel sheet stationary during the test; An excitation unit is used to apply a controllable mechanical excitation to the friction element and / or the steel sheet; An observation unit, located on the adjustable boundary unit or the base, is used to acquire relative motion information between the friction element and the steel sheet during the test.

2. The dry clutch vibration characteristic testing device according to claim 1, characterized in that, The first boundary includes a first substrate with a central hole and a plurality of extension arms extending axially from one side of the first substrate. The plurality of extension arms are distributed circumferentially to enclose a clamping space for clamping the steel sheet. The first substrate is provided with a first mounting portion for connecting to the base. The second boundary includes a second base plate with a central hole, and the second base plate is provided with a plurality of limiting structures in the circumferential direction for lateral constraint and support of the extension arm when it is extended; and the second base plate is provided with a second mounting part for sliding connection with the base.

3. The dry clutch vibration characteristic testing device according to claim 2, characterized in that, The multiple extension arms are arranged in parallel, and the gaps between adjacent extension arms form a clamping gap for clamping the local protrusions of the steel sheet; The limiting structure is a limiting block protruding from the second substrate, and multiple limiting blocks are fitted into multiple clamping gaps in a one-to-one correspondence.

4. The dry clutch vibration characteristic testing device according to claim 3, characterized in that, Two first mounting portions are provided, located on the radial sides of the first substrate respectively; two second mounting portions are provided, located on the radial sides of the second substrate respectively; and both the first mounting portions and the second mounting portions are provided with adjustment elongated holes extending along the length direction of the base. The base has a U-shaped cross-section, and its open end face has a plurality of fixing positions arranged along its length; the fastener passes through the adjustment elongated hole and can be selectively locked with any of the fixing positions to fix the distance between the first boundary and the second boundary.

5. The dry clutch vibration characteristic testing device according to claim 4, characterized in that, The first substrate and the second substrate are polygonal, and a plurality of the extended arms are respectively disposed on each edge of the first substrate; a plurality of the limiting blocks are correspondingly disposed on each edge of the second substrate and protrude radially from its edge.

6. The dry clutch vibration characteristic testing device according to claim 1, characterized in that, The drive unit includes a motor, a splined shaft, and a coupling. The splined shaft is used to mount the friction element, and the motor drives the splined shaft to rotate through the coupling.

7. The dry clutch vibration characteristic testing device according to claim 1, characterized in that, The excitation unit includes an air compressor, a solenoid valve, and a nozzle. The solenoid valve is connected to a controller and is used to control the nozzle to apply pulsed gas excitation to the friction element according to a preset program. Multiple nozzles are provided and point to different positions of the friction element in the circumferential or axial direction.

8. The dry clutch vibration characteristic testing device according to claim 1, characterized in that, The observation unit includes an observation window formed by the first boundary and / or the second boundary, and / or a high-speed camera device disposed on the base.

9. The dry clutch vibration characteristic testing device according to claim 1, characterized in that, It also includes a vibration sensor mounted on the second boundary or base for collecting vibration signals generated by the collision between the friction element and the boundary.

10. A test method based on the dry clutch vibration characteristic test device according to any one of claims 1-9, characterized in that, Includes the following steps: The number of friction elements and the gap between the plates were determined according to the test plan. The friction elements were installed on the drive unit, and the steel plates were installed on the adjustable boundary unit and the distance between the first boundary and the second boundary was adjusted. The drive unit is started to rotate the friction element at a set speed, and the excitation unit is controlled to apply external excitation to the friction element according to the set excitation parameters; The vibration signal generated by the interaction between the friction element and the adjustable boundary unit is acquired by the acquisition unit, and visual or physical field information reflecting the relative motion between the friction element and the steel sheet is obtained by the observation unit. Based on the collected experimental data, the parameters of the dynamic model reflecting the clutch shimmy-collision behavior were calibrated and verified, and vibration characteristic simulation and mechanism analysis were performed based on the verified model.

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