Experimental Study For End-of-line Inspection Method On The NVH Performance Of Drive Axle

Main reducer assembly of the drive axle is a key part of automobile driving system,the overall quality of the automobile will be directly affected by the quality of the main reducer assembly of the drive axle.With the continuous improvement of living standards,people' requirements on the automobile NVH performance are also continuously improved.The NVH Performance improvement of the main reducer has been the focus of academic research and enterprise technical difficulties.Vehicle End-of-Line inspection for NVH performance is the last line of defense for main reducer assembly product quality monitoring,having a reasonable End-of-Line inspection method is the key to control NVH performance of the main reducer assembly product.This paper is based on the project that research and development of End-of-Line inspection system for vibration of main reducer assembly,researches on the test method for vibration End-of-Line inspection method of a batch of main reduced samples based on statistical sampling method.Summarized the inspection method based on the research on the relationship between the vehicle internal noise and the vibration of the main reducer of the chassis and the relationship between the vibration of main reducer on End-of-Line inspection and the vibration of main reducer of the vehicle,then the test method of sampling research is verified by the sample population on the End-of-Line inspection system.1)Take vehicle NVH drum test with10 main reducer as the research object Randomly selected in the same batch of 40 main reducer samples for getting the Internal noise signal and the drive axle assembly vibration signal.Then take a repeatability test and order analysis of the collected signals for finding out all speed and frequency in which the 11 characteristic order noise of the main reducing gear pair is the most obvious effect of overall sound pressure level.2)The linear regression analysis was performed on 11 order noise of Internal rear noise signal and 11 order vibration of main reducer by all the direction of each measuring point in the speed and frequency band under the various conditions already choose,determined vibration detection parameter for End-of-Line inspection system by comparing the correlation coefficient square.Calculated torque and rotational speed of test bench according to the vehicle test conditions.take a vibration test on the selected 10 main reducer objects during the debugging process of the test bench,then a linear regression analysis was carried out on the vibration test results of the test bench and the vibration test results of the vehicle to verify the consistency between bench test and vehicle test.3)Built a test bench of main reducer vibration End-of-Line inspection,then took a Vibration test of bench body to verify the NVH performance of the test bench itself and the correctness of the collection software.The overall 40 samples were tested vibration on the test bench,and did a judgment on the remaining 30 main reducers by the detection threshold equals to the self-learning curve generated from the 10 main reducers' 11 order vibration data in the frequency band.The pass rate of 80% to 90% proved that detection threshold has the effect of evaluation and detection method is feasible.