First-order vibration fault testing method for hydraulic torque converter of rear-drive transmission

Abstract

The invention discloses a first-order vibration fault testing method for a hydraulic torque converter of a rear-drive transmission, and belongs to the technical field of automobile transmission system testing. Related information of the hydraulic torque converter carried by the to-be-tested vehicle is confirmed, and the relation between the order and the frequency of the hydraulic torque converter is calculated; determining a vehicle related structure, working condition information and a vehicle state during abnormal jittering; making a test project plan; arranging a vibration sensor, connecting the vibration sensor to LMS equipment, and carrying out a full-working-condition test; data are collected, and vibration energy contribution is analyzed; integrating a test result, judging a problem part, and formulating an optimization scheme; and verifying the effect of the optimized sample piece, and finally determining a problem sample piece. According to the method, the technical problem that the first-order vibration fault of the hydraulic torque converter under the high-speed working condition of a rear-drive pickup truck is difficult to accurately recognize and position is solved, the reliability and driving smoothness of a transmission system are improved, and scientific and reliable technical support is provided for design optimization and fault diagnosis of the hydraulic torque converter.

Description

Technical Field

[0001] This invention relates to a method for testing first-order vibration faults in a rear-wheel drive transmission hydraulic torque converter, belonging to the field of automotive transmission system testing technology. Background Technology

[0002] With the rapid development of new energy vehicle power systems, hybrid rear-wheel drive transmissions have become the mainstream technology due to their superior handling performance and driving experience. As the core transmission component of automatic transmissions, the torque converter transmits power via hydraulic fluid and possesses dual functions of damping and torque gain, making it widely used in commercial pickup trucks and other vehicles.

[0003] However, under high-speed conditions, rear-wheel-drive pickup trucks often exhibit first-order vibrations that occur at the same frequency as the engine speed. This vibration significantly affects driving smoothness and transmission system reliability. Analysis indicates that this type of vibration is primarily caused by the following factors:

[0004] 1. During high-speed operation, poor dynamic balance of the pump wheel, turbine, or guide wheel inside the hydraulic torque converter, or jamming of the guide wheel's one-way clutch, can lead to periodic torque fluctuations. These fluctuations are amplified by the drive shaft and form significant vibrations.

[0005] 2. When the torque converter enters the lock-up condition, the nonlinear damping characteristics of the clutch friction plate may cause a sudden change in torque, which in turn can trigger resonance in the transmission system.

[0006] 3. Rear-wheel drive pickup trucks use a non-load-bearing body structure and a long driveshaft layout. Their lower torsional stiffness will further aggravate vibration transmission, making high-speed vibration problems more prominent.

[0007] Currently, there is a lack of convenient, accurate, and feasible technical solutions for diagnosing high-speed abnormal vibrations in the torque converters of rear-wheel drive pickup trucks. This makes it difficult to effectively identify and locate such faults, which has become a key technical bottleneck restricting the improvement of the reliability of rear-wheel drive transmissions. Summary of the Invention

[0008] To address the problems existing in the background art, the present invention provides a method for testing first-order vibration faults in a rear-drive transmission hydraulic torque converter.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a method for testing first-order vibration faults in a rear-drive transmission hydraulic torque converter, the method comprising the following steps:

[0010] S1: Confirm the relevant information of the hydraulic torque converter installed in the vehicle under test, and calculate the relationship between the order and frequency of the hydraulic torque converter;

[0011] S2: Determine the vehicle's relevant structure, operating conditions, and vehicle status during abnormal vibrations;

[0012] S3: Develop a test project plan;

[0013] S4: Based on the fault-related components and vibration transmission path, vibration sensors are respectively placed at the hydraulic torque converter housing, the suspension, and the seat guide rail;

[0014] S5: Connect all vibration sensor signal cables to the LMS device, turn on the device and calibrate it; connect the LMS device to the vehicle's OBD interface via the OBD data cable, and use the corresponding DBC file to read vehicle information from the CAN signal;

[0015] S6: Start the vehicle and conduct tests according to the project plan and on-site test results, carrying out full-condition testing;

[0016] S7: Collect data during the acceleration process under various working conditions, and analyze the first-order line and vibration energy contribution of each frequency band near 30Hz by observing the colormap image of each vibration measuring point.

[0017] S8: Based on the comprehensive test results under all operating conditions, identify problematic components and formulate optimization solutions;

[0018] S9: Repeat S3-S7 to verify the effect of the optimized sample and finally determine the problematic sample.

[0019] Furthermore, the calculation formulas for the order and frequency of the hydraulic torque converter mentioned in S1 are as follows:

[0020]

[0021] in:

[0022] Indicates order;

[0023] Indicates the vibration frequency;

[0024] This indicates the engine speed.

[0025] Furthermore, the vehicle status during abnormal vibration as described in S2 includes: vehicle speed, engine speed, engine torque, vehicle gear, and torque converter lock-up condition.

[0026] Furthermore, step S3 includes the following steps:

[0027] S301: Confirm vehicle problem condition information. When analyzing conditions related to NVH performance, confirm the vehicle information read from the CAN bus and confirm the solenoid valve status corresponding to the torque converter's working status.

[0028] S302: Based on the collected vehicle speed information and corresponding RPM range, as well as the vehicle information read from the CAN bus, the test conditions are matched and formulated.

[0029] S303: The test project plan includes the following two operating conditions:

[0030] First working condition:

[0031] Stationary operating condition: Used to eliminate load interference and verify whether there is first-order vibration when there is no load. The specific test conditions are: rapid acceleration in P gear while stationary: the engine speed increases from 750 rpm to 4000 rpm, and speed and vibration signals are collected throughout the process.

[0032] Second operating condition:

[0033] Motion Conditions: Used to simulate actual driving and verify the first-order vibration characteristics under load, the hydraulic torque converter undergoes D-gear acceleration transient condition testing under both direct-drive and non-direct-drive conditions, including:

[0034] 1st gear: RPM 0-4000;

[0035] 2nd gear: 1000-3800rpm;

[0036] 3rd gear: 1000-3500rpm;

[0037] 4th gear: 1000-3200rpm;

[0038] 5th gear: 1200-2800rpm;

[0039] 6th gear: 1300-2500rpm;

[0040] 7th gear: 1400-2300rpm;

[0041] 8th gear: 1600-2000rpm;

[0042] For each gear and each torque converter state, the engine speed, vehicle speed, torque, and vibration signals are collected.

[0043] Furthermore, at the hydraulic torque converter housing mentioned in S4, vibration signals of the faulty core component are directly collected to determine whether the vibration is directly generated by the torque converter; at the mounting point, signals are collected to determine whether the vibration is transmitted to the vehicle body through the mounting point; at the seat rail, signals are directly associated with the user's subjective feelings to verify whether the vibration ultimately affects the driving experience.

[0044] Furthermore, step S6 includes the following steps:

[0045] S601: Start the vehicle and perform the test in the order of stationary working condition, non-direct drive motion condition and direct drive motion condition;

[0046] S602: Under each operating condition, the engine speed is uniformly controlled to increase from the lower limit to the upper limit of the acquisition range. The LMS device simultaneously acquires the vibration frequency-amplitude signal and engine speed-torque-gear parameters to generate time series data.

[0047] S603: Repeat the test 2-3 times.

[0048] Furthermore, the vibration data acquisition and analysis results under different working conditions in S7 are as follows:

[0049] Stationary operation (P gear, stationary acceleration): The torque converter is in hydraulic transmission mode and there is no transmission load, and there is no first-order vibration line; if a first-order vibration line appears, it indicates that the torque converter itself has poor dynamic balance.

[0050] Non-direct-drive motion condition: The hydraulic torque converter is directly connected to the transmission, and only the first-order vibration line appears. Its vibration energy is lower than the second-order vibration energy of the engine, and the difference in first-order vibration energy between 1st and 8th gears is within the preset range. The vibration is greatest at the hydraulic torque converter.

[0051] Direct-drive motion condition: There is a clear first-order vibration line. When the engine torque reaches the conversion torque between the first and second springs of the torsional damper, the first-order vibration energy increases to be equivalent to the second-order vibration energy of the engine, and the vibration energy at the seat guide rail increases.

[0052] Compared with the prior art, the beneficial effects of the present invention are:

[0053] This invention accurately captures vibration transmission path characteristics by calculating the relationship between the order and frequency of the hydraulic torque converter and combining joint testing under stationary and dynamic conditions. By scientifically arranging vibration sensors in the torque converter housing, suspension mounts, and seat rails, it collects and analyzes the first-order line and vibration energy contribution in colormap images under various conditions, clearly identifying the root cause of the fault and developing targeted optimization solutions. The invention is convenient to operate and provides accurate testing, solving the technical challenge of accurately identifying and locating first-order vibration faults in hydraulic torque converters under high-speed conditions in rear-wheel-drive pickup trucks. This improves the reliability of the transmission system and driving smoothness, providing scientific and reliable technical support for the design optimization and fault diagnosis of hydraulic torque converters. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the vibration sensor at the hydraulic torque converter;

[0055] Figure 2 This is a schematic diagram of the vibration sensor at the right suspension point;

[0056] Figure 3 This is a schematic diagram of the vibration sensor at the rear suspension. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0058] A method for testing first-order vibration faults in a rear-drive transmission hydraulic torque converter, the method comprising the following steps:

[0059] S1: Confirm the relevant information of the hydraulic torque converter installed in the vehicle under test, and calculate the relationship between the order and frequency of the hydraulic torque converter;

[0060] S2: Determine the vehicle's relevant structure, operating condition information, and vehicle status during abnormal vibrations to prepare for subsequent reconstruction of the problematic operating conditions;

[0061] S3: Develop a test project plan based on the actual situation;

[0062] S4: Based on the fault-related components and vibration transmission path, vibration sensors are placed at the torque converter housing, the mounting points (right and rear mountings), and the seat rails to ensure that the influence of first-order vibrations from components such as the crankshaft and bearings can be eliminated, and important information such as engine speed, vehicle speed, engine torque, gear position, and whether the engine is locked can be read. Vibration signals are collected from multiple dimensions, and vibration propagation is analyzed from the fault source, transmission path, and user experience. The sensors are fixed with bolts or attracted by strong magnets to ensure a tight fit with the measuring point surface and avoid signal distortion caused by loosening.

[0063] S5: Connect all vibration sensor signal cables to the LMS device (professional NVH data acquisition instrument), turn on the device and calibrate it (ensure the acquisition frequency and sensitivity parameters are correct); connect the LMS device to the vehicle's OBD interface via the OBD data cable, and use the corresponding DBC file to read vehicle information from the CAN signal (focusing on engine speed, vehicle speed, engine torque, gear position, and whether it is locked); establish a data synchronization acquisition link between the sensors, acquisition device, and vehicle parameters to ensure that the vibration signal corresponds one-to-one with the vehicle operating parameters.

[0064] Start the vehicle at idle speed and confirm that the LMS device can read parameters such as engine speed, vehicle speed, torque, gear, and torque converter lock-up status in real time, and that the vibration sensor can collect a stable signal to test the effectiveness of the device connection.

[0065] S6: Start the vehicle and conduct tests according to the project plan and on-site test results, carrying out full-condition tests; obtain vibration signals and raw vehicle parameter data under different conditions to provide materials for subsequent analysis.

[0066] S7: Collect data during the acceleration process under various operating conditions, and analyze the first-order line and vibration energy contribution of each frequency band near 30Hz by observing the colormap image of each vibration measuring point to narrow down the range of fault causes.

[0067] During testing, we focus on whether there is a relationship between engine speed, torque, vehicle speed and test results. We analyze the problematic parts based on the test results and revise and optimize the test plan to achieve comprehensive, accurate and efficient data collection.

[0068] S8: Based on the comprehensive test results under all operating conditions, if the hydraulic torque converter is directly connected and the first-order vibration energy increases when the damper spring is switched, the torsional damper of the hydraulic torque converter is determined to be a problematic component, and an optimization plan is formulated (such as removing the second-order spring of the torsional damper).

[0069] S9: Repeat S3-S7 to verify the effect of the optimized sample and finally determine the problem sample (when making the verification sample, the simulation model calculation results, industry experience, cost and verification cycle should be considered).

[0070] The optimized hydraulic torque converter prototype was installed on the vehicle under test, and the test procedure from S4 to S8 was repeated.

[0071] Comparing vibration data before and after optimization: If the first-order vibration energy under direct-drive conditions is significantly reduced after optimization and there is no sudden increase during spring switching, it proves that the optimization is effective. At the same time, it confirms that the torsional damper of the original hydraulic torque converter is the final problem sample.

[0072] If the optimization effect does not meet expectations, return to S8 to reanalyze the data and adjust the optimization scheme (such as modifying the spring stiffness) until the vibration problem is resolved.

[0073] Furthermore, the calculation formulas for the order and frequency of the hydraulic torque converter mentioned in S1 are as follows:

[0074]

[0075] in:

[0076] Indicates order;

[0077] Indicates the vibration frequency;

[0078] Indicates engine speed;

[0079] The hydraulic torque converter is of the first order. The engine speed changes according to different test conditions, and the engine speed is linearly related to the vibration frequency.

[0080] Furthermore, the vehicle states during the abnormal vibration described in S2 include: vehicle speed (e.g., 100-120 km / h), engine speed (e.g., 2000-2500 rpm), and engine torque (e.g., 180-220 N). m), vehicle gear (e.g., D gear 6-8 gear), torque converter lock-up condition (direct drive / non-direct drive state), road surface type (e.g., highway straight road surface), and load condition (e.g., no load / full load).

[0081] Furthermore, S3 includes the following steps: S301: Confirm vehicle problem condition information, when analyzing conditions related to NVH performance, confirm other vehicle information such as engine torque, speed, vehicle gear and locking status read from the CAN line, and confirm the solenoid valve status corresponding to the working state of the hydraulic torque converter.

[0082] S302: Based on the collected vehicle speed information and corresponding RPM range, as well as other vehicle information such as engine torque, RPM, vehicle gear position, and lock status read from the CAN bus, the test conditions are matched and formulated.

[0083] S303: The test project plan includes the following two operating conditions:

[0084] First working condition:

[0085] Stationary operating condition: Used to eliminate load interference, verify whether there is first-order vibration when there is no load, and determine whether the vibration originates from the torque converter itself. The specific test conditions are: rapid acceleration in P gear while stationary: the engine speed increases from 750rpm (idle speed) to 4000rpm (covering the high-speed operating speed), and the speed and vibration signals are collected throughout the process.

[0086] Second operating condition:

[0087] Motion Conditions: Used to simulate actual driving, verify the first-order vibration characteristics under load, and determine whether the load exacerbates vibration. The hydraulic torque converter undergoes D-gear slow acceleration transient condition testing under both direct-drive and non-direct-drive conditions, including:

[0088] 1st gear: RPM 0-4000;

[0089] 2nd gear: 1000-3800rpm;

[0090] 3rd gear: 1000-3500rpm;

[0091] 4th gear: 1000-3200rpm;

[0092] 5th gear: 1200-2800rpm;

[0093] 6th gear: 1300-2500rpm;

[0094] 7th gear: 1400-2300rpm;

[0095] 8th gear: 1600-2000rpm;

[0096] For each gear and each torque converter state, the engine speed, vehicle speed, torque, and vibration signals are collected.

[0097] Furthermore, at the hydraulic torque converter housing mentioned in S4, vibration signals of the faulty core component are directly collected to determine whether the vibration is directly generated by the torque converter; the mount is the connection point between the powertrain and the vehicle body, and the mount is used to collect signals here to determine whether the vibration is transmitted to the vehicle body through the mount; the seat rail is used to directly correlate with the user's subjective feelings (seat vibration) to verify whether the vibration ultimately affects the driving experience.

[0098] Furthermore, step S6 includes the following steps:

[0099] S601: Start the vehicle and perform the test in the order of stationary working condition, non-direct drive motion condition and direct drive motion condition;

[0100] S602: Under each operating condition, the engine speed is uniformly controlled to increase from the lower limit to the upper limit of the acquisition range (such as 750-4000 rpm under stationary operating condition). The LMS device synchronously acquires vibration frequency-amplitude signals and engine speed-torque-gear parameters to generate time series data.

[0101] S603: Repeat the test 2-3 times to ensure data repeatability and avoid random errors from a single test.

[0102] Furthermore, the vibration data acquisition and analysis results under different working conditions in S7 are as follows:

[0103] Stationary operation (P gear, stationary acceleration): The torque converter is in hydraulic transmission mode and there is no transmission load, and there is no first-order vibration line; if a first-order vibration line appears, it indicates that the torque converter itself has poor dynamic balance.

[0104] Non-direct-drive operating conditions: The hydraulic torque converter is directly connected to the transmission (with load), and only the first-order vibration line appears. Its vibration energy is lower than the second-order vibration energy of the engine, and the difference in first-order vibration energy between gears 1-8 is within the preset range. The vibration is greatest at the hydraulic torque converter. This indicates that the hydraulic transmission buffers the vibration and is not the main cause of the fault.

[0105] Direct-drive operation: A clear first-order vibration line exists. When the engine torque reaches the conversion torque between the first and second-order springs of the torsional damper, the first-order vibration energy increases to be comparable to the second-order vibration energy of the engine. The vibration energy at the seat guide rail increases, indicating that the fault is related to the spring conversion of the damper under direct-drive operation.

[0106] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0107] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for testing first-order vibration faults in a rear-drive transmission hydraulic torque converter, characterized in that: The method includes the following steps: S1: Confirm the relevant information of the hydraulic torque converter installed in the vehicle under test, and calculate the relationship between the order and frequency of the hydraulic torque converter; S2: Determine the vehicle's relevant structure, operating conditions, and vehicle status during abnormal vibrations; S3: Develop a test project plan; S4: Based on the fault-related components and vibration transmission path, vibration sensors are respectively placed at the hydraulic torque converter housing, the suspension, and the seat guide rail; S5: Connect all vibration sensor signal cables to the LMS device, turn on the device and calibrate it; connect the LMS device to the vehicle's OBD interface via the OBD data cable, and use the corresponding DBC file to read vehicle information from the CAN signal; S6: Start the vehicle and conduct tests according to the project plan and on-site test results, carrying out full-condition testing; S7: Collect data during the acceleration process under various working conditions, and analyze the first-order line and vibration energy contribution of each frequency band near 30Hz by observing the colormap image of each vibration measuring point. S8: Based on the comprehensive test results under all operating conditions, identify problematic components and formulate optimization solutions; S9: Repeat S3-S7 to verify the effect of the optimized sample and finally determine the problematic sample.

2. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 1, characterized in that: The calculation formulas for the order and frequency of the hydraulic torque converter mentioned in S1 are as follows: in: Indicates order; Indicates the vibration frequency; This indicates the engine speed.

3. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 2, characterized in that: The vehicle status during abnormal vibrations described in S2 includes: vehicle speed, engine speed, engine torque, vehicle gear, and torque converter lock-up condition.

4. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 3, characterized in that: S3 includes the following steps: S301: Confirm vehicle problem condition information. When analyzing conditions related to NVH performance, confirm the vehicle information read from the CAN bus and confirm the solenoid valve status corresponding to the torque converter's working status. S302: Based on the collected vehicle speed information and corresponding RPM range, as well as the vehicle information read from the CAN bus, the test conditions are matched and formulated. S303: The test project plan includes the following two operating conditions: First working condition: Stationary operating condition: Used to eliminate load interference and verify whether there is first-order vibration when there is no load. The specific test conditions are: rapid acceleration in P gear while stationary: the engine speed increases from 750 rpm to 4000 rpm, and speed and vibration signals are collected throughout the process. Second operating condition: Motion Conditions: Used to simulate actual driving and verify the first-order vibration characteristics under load, the hydraulic torque converter undergoes D-gear acceleration transient condition testing under both direct-drive and non-direct-drive conditions, including: 1st gear: RPM 0-4000; 2nd gear: 1000-3800rpm; 3rd gear: 1000-3500rpm; 4th gear: 1000-3200rpm; 5th gear: 1200-2800rpm; 6th gear: 1300-2500rpm; 7th gear: 1400-2300rpm; 8th gear: 1600-2000rpm; For each gear and each torque converter state, the engine speed, vehicle speed, torque, and vibration signals are collected.

5. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 4, characterized in that: The hydraulic torque converter housing in S4 is used to directly collect vibration signals from the faulty core component to determine whether the vibration is directly generated by the torque converter; the mounting is used to collect signals from this location to determine whether the vibration is transmitted to the vehicle body through the mounting; the seat rail is used to directly correlate with the user's subjective feelings to verify whether the vibration ultimately affects the driving experience.

6. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 5, characterized in that: S6 includes the following steps: S601: Start the vehicle and perform the test in the order of stationary working condition, non-direct drive motion condition and direct drive motion condition; S602: Under each operating condition, the engine speed is uniformly controlled to increase from the lower limit to the upper limit of the acquisition range. The LMS device simultaneously acquires the vibration frequency-amplitude signal and engine speed-torque-gear parameters to generate time series data. S603: Repeat the test 2-3 times.

7. The method for testing first-order vibration faults in a rear-drive transmission torque converter according to claim 6, characterized in that: The vibration data acquisition and analysis results under different working conditions in S7 are as follows: Stationary operation (P gear, stationary acceleration): The torque converter is in hydraulic transmission mode and there is no transmission load, and there is no first-order vibration line; if a first-order vibration line appears, it indicates that the torque converter itself has poor dynamic balance. Non-direct-drive motion condition: The hydraulic torque converter is directly connected to the transmission, and only the first-order vibration line appears. Its vibration energy is lower than the second-order vibration energy of the engine, and the difference in first-order vibration energy between 1st and 8th gears is within the preset range. The vibration is greatest at the hydraulic torque converter. Direct-drive motion condition: There is a clear first-order vibration line. When the engine torque reaches the conversion torque between the first and second springs of the torsional damper, the first-order vibration energy increases to be equivalent to the second-order vibration energy of the engine, and the vibration energy at the seat guide rail increases.

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