AT gearbox shell reliability test method

Abstract

The invention relates to a reliability test method for an AT gearbox shell. The method comprises the following steps: detecting the profile tolerance of the AT gearbox shell by adopting a three-coordinate measurement method; the AT gearbox shell is sent into a special detection room, a test bed used for placing the AT gearbox shell is arranged in the detection room, extreme environmental conditions are simulated in the detection room, and the adaptability of the AT gearbox shell under actual working conditions is verified; axial stress, radial stress and combined stress are applied to the AT gearbox shell through a test bed, strain, displacement and temperature parameters of the AT gearbox shell are monitored in real time, a stress-strain curve is recorded, and whether abnormal deformation or cracks occur or not is observed; and when the AT gearbox shell is obviously deformed and cracked or the stress-strain curve has an inflection point, judging that the AT gearbox shell is invalid, recording the stress value at the moment as the breaking stress, and evaluating whether the strength of the AT gearbox shell meets the design requirement or not according to the failure mode and the breaking stress. According to the test method, the reliability of the AT gearbox shell can be accurately verified.

Description

Technical Field

[0001] This invention relates to the field of automotive transmission testing, and in particular to a reliability testing method for an AT transmission housing. Background Technology

[0002] An automatic transmission (AT) is an electro-hydraulic multi-gear automatic transmission, belonging to the category of instrumentation equipment. Its structure consists of core components such as a torque converter, planetary gear mechanism, hydraulic control system, electronic control system, and cooling control system. Automatic gear shifting is achieved through the coordinated operation of the power transmission system and the gear shifting system. The control system automatically adjusts the shift timing according to the vehicle's condition, requiring no driver intervention, and the shifting process is uninterrupted in terms of traction.

[0003] As a crucial foundational component of the transmission assembly, the transmission housing connects to other vehicle parts such as the engine and suspension. It assembles gears, shafts, bearings, shift forks, and other related components into a unified whole, maintaining the correct positioning of gears and shafts and ensuring the coordinated transmission of power according to specific gearing relationships. All shafts of the transmission are supported on the housing via bearings. During gear transmission, the housing bears significant loads, and simultaneously withstands the inertial forces and impacts generated by the powertrain during vehicle braking or acceleration, resulting in substantial deformation and stress. Therefore, the strength, rigidity, and fatigue performance of the housing directly affect the reliability and lifespan of the transmission, and consequently, the overall vehicle performance. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an AT gearbox housing reliability test method that can perform deformation test on the gearbox housing.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a reliability test method for an AT gearbox housing, the innovation of which is: including the following steps: S1: First, the contour of the AT gearbox housing is detected using a three-coordinate measurement method; S2: Next, the AT transmission housing is sent into a dedicated testing room. The testing room is equipped with a test bench for placing the AT transmission housing. Extreme environmental conditions are simulated in the testing room to verify the adaptability of the AT transmission housing under actual working conditions. S3: Then, axial, radial and combined stresses are applied to the AT gearbox housing through the test bench, and the strain, displacement and temperature parameters of the AT gearbox housing are monitored in real time. The stress-strain curve is recorded to observe whether there is abnormal deformation or cracks. S4: Finally, when the AT transmission housing shows obvious deformation, cracks, or an inflection point in the stress-strain curve, it is considered a failure. The stress value at this time is recorded as the destructive stress. Based on the failure mode and destructive stress, the strength of the AT transmission housing is evaluated to determine whether it meets the design requirements.

[0006] Furthermore, in step S1, the three-coordinate measurement method is as follows: First, the AT gearbox housing is placed on the worktable, and then the measurement parameters are set, including the measurement method, speed and accuracy. The probe is used to perform point measurement or continuous scanning on the surface of the AT gearbox housing to obtain three-dimensional coordinate data. Finally, the measurement data is compared with the CAD model to accurately calculate various geometric tolerances.

[0007] Furthermore, in step S2, the testing room is equipped with high-pressure atomizing nozzles, a combined heating and cooling unit, a fan, and LED lights. The high-pressure atomizing nozzles are used to spray the surface of the AT gearbox housing, the combined heating and cooling unit is used to raise or lower the temperature around the AT gearbox housing, the fan is used to simulate a strong wind environment, and the LED lights are used to simulate sunlight. The temperature and humidity are controlled by the combined operation of the high-pressure atomizing nozzles, the combined heating and cooling unit, the fan, and the LED lights, as well as in icing, snowfall, strong winds, and foggy weather.

[0008] Furthermore, in step S3, the stress application level is gradually increased starting from 50% of the rated stress, and each stress level is maintained for 10 minutes.

[0009] The advantages of this invention are as follows: The testing method of this invention first employs a three-coordinate measuring machine to detect the contour of the AT transmission housing, achieving extremely high measurement accuracy and precisely calculating geometric tolerances. Then, by simulating extreme environments, the performance of the AT transmission housing under extreme conditions is verified. Finally, destructive testing directly obtains the ultimate strength data of the housing, accurately verifying the reliability of the AT transmission housing. Detailed Implementation

[0010] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0011] The reliability testing method for the AT gearbox housing of the present invention is achieved through the following steps: S1: First, the contour of the AT gearbox housing is detected using a three-coordinate measurement method.

[0012] The three-coordinate measurement method is as follows: First, place the AT gearbox housing on the worktable, then set the measurement parameters, including the measurement method, speed and accuracy. Use a probe to perform point measurements or continuous scanning on the surface of the AT gearbox housing to obtain three-dimensional coordinate data. Finally, compare the measurement data with the CAD model to accurately calculate various geometric tolerances.

[0013] S2: Next, the AT transmission housing is sent into a dedicated testing room. The testing room is equipped with a test bench for placing the AT transmission housing. Extreme environmental conditions are simulated in the testing room to verify the adaptability of the AT transmission housing under actual working conditions.

[0014] The testing room is equipped with high-pressure atomizing nozzles, a combined heating and cooling unit, a fan, and LED lights. The high-pressure atomizing nozzles are used to spray the surface of the AT gearbox housing, the combined heating and cooling unit is used to raise or lower the temperature around the AT gearbox housing, the fan is used to simulate strong winds, and the LED lights are used to simulate sunlight. The high-pressure atomizing nozzles, the combined heating and cooling unit, the fan, and the LED lights work together to control temperature and humidity, as well as to simulate icing, snowfall, strong winds, and heavy fog.

[0015] Specifically, when conducting extreme weather simulations, the following applies: Using a combined heating and cooling unit, the ambient temperature is lowered to -40℃.

[0016] By using a high-pressure atomizing nozzle with a pressure of 7MPa and droplets of 3-5μm, the humidity is increased to over 95%RH to simulate a high-humidity condensation environment.

[0017] A fan was used to simulate a strong wind environment with a wind speed of 10 m / s.

[0018] Controllable snowflakes are generated through high-pressure atomizing nozzles, with a snowfall intensity of 5-10 mm / h.

[0019] In low-temperature and high-humidity environments, the shell surface can be frozen by spraying water or refrigeration, and the ice layer thickness can be precisely controlled between 0.1-10mm.

[0020] An ultrasonic atomizer or high-pressure nozzle is used to generate droplets with a diameter of 5-50 μm. The concentration of mist particles and the liquid water content are adjusted, with the mist particle concentration ranging from 0.1-20 g / m³. 3 It can simulate visibility ranging from 10 meters to 30 kilometers.

[0021] The AT transmission housing was placed in a simulated environment and run stably for more than 2 hours to ensure that it reached temperature equilibrium.

[0022] The strength, stiffness, and fatigue performance of the AT transmission housing were tested under a combination of extreme cold, high humidity, strong winds, snow / ice, and heavy fog.

[0023] S3: Then, axial, radial and combined stresses are applied to the AT gearbox housing through the test bench. The stress application level starts from 50% of the rated stress and is gradually increased, with each stress level held for 10 minutes. The strain, displacement and temperature parameters of the AT gearbox housing are monitored in real time, and the stress-strain curve is recorded to observe whether there is any abnormal deformation or cracks.

[0024] S4: Finally, when the AT transmission housing shows obvious deformation, cracks, or an inflection point in the stress-strain curve, it is considered a failure. The stress value at this time is recorded as the destructive stress. Based on the failure mode and destructive stress, the strength of the AT transmission housing is evaluated to determine whether it meets the design requirements.

[0025] The test method of this invention first uses a three-coordinate measurement method to detect the contour of the AT gearbox housing, which has extremely high measurement accuracy and can accurately calculate the form and position tolerances. Then, by simulating extreme environments, the performance of the AT gearbox housing under extreme conditions is verified. Finally, through destructive testing, the ultimate strength data of the housing can be directly obtained, accurately verifying the reliability of the AT gearbox housing.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A reliability test method for an AT gearbox housing, characterized in that: Includes the following steps: S1: First, the contour of the AT gearbox housing is detected using a three-coordinate measurement method; S2: Next, the AT transmission housing is sent into a dedicated testing room. The testing room is equipped with a test bench for placing the AT transmission housing. Extreme environmental conditions are simulated in the testing room to verify the adaptability of the AT transmission housing under actual working conditions. S3: Then, axial, radial and combined stresses are applied to the AT gearbox housing through the test bench. The strain, displacement and temperature parameters of the AT gearbox housing are monitored in real time, and the stress-strain curve is recorded to observe whether there is abnormal deformation or cracks. S4: Finally, when the AT transmission housing shows obvious deformation, cracks, or an inflection point in the stress-strain curve, it is considered a failure. The stress value at this time is recorded as the destructive stress. Based on the failure mode and destructive stress, the strength of the AT transmission housing is evaluated to determine whether it meets the design requirements.

2. The AT gearbox housing reliability test method according to claim 1, characterized in that: In step S1, the three-coordinate measurement method is as follows: First, the AT gearbox housing is placed on the worktable. Then, the measurement parameters are set, including the measurement method, speed and accuracy. The probe is used to perform point measurement or continuous scanning on the surface of the AT gearbox housing to obtain three-dimensional coordinate data. Finally, the measurement data is compared with the CAD model to accurately calculate various geometric tolerances.

3. The AT gearbox housing reliability test method according to claim 1, characterized in that: In step S2, the testing room is equipped with high-pressure atomizing nozzles, a combined heating and cooling unit, a fan, and LED lights. The high-pressure atomizing nozzles are used to spray the surface of the AT gearbox housing, the combined heating and cooling unit is used to raise or lower the temperature around the AT gearbox housing, the fan is used to simulate a strong wind environment, and the LED lights are used to simulate sunlight. The temperature and humidity are controlled by the combined use of the high-pressure atomizing nozzles, the combined heating and cooling unit, the fan, and the LED lights, as well as the conditions of icing, snowfall, strong winds, and heavy fog.

4. The AT gearbox housing reliability test method according to claim 1, characterized in that: In step S3, the stress application level is gradually increased starting from 50% of the rated stress, and each stress level is maintained for 10 minutes.