Research On Test And Evaluation Method Of Rattle Noise Of A Certain Type Of Dual-clutch Transmission

Transmission rattle noise is a kind of broadband noise,which is easy to cause subjective annoyance to the drivers and passengers in the car.The dual-clutch transmission has two clutches and two input shafts,and the structure is complex and prone to rattle.At present,the rattle test and evaluation of the dual-clutch transmission are not comprehensive enough.Therefore,this paper takes a certain type of dual-clutch transmission as the research object,carries out the vehicle test and bench test of the dual-clutch transmission,and establishes a rattle-on evaluation model of the dual-clutch transmission.The specific research contents are as follows:(1)The mechanism of rattle of gears of dual-clutch transmission was explored,the internal and external excitations when rattle occurred were analyzed,and various factors affecting the rattle of gears were summarized.The whole vehicle road test is used to collect the rattle noise of the transmission under the condition that rattle is prone to occur.The collected noise data is screened and intercepted,and a rattle noise sample is made for subjective evaluation test.(2)According to the noise samples,several common subjective evaluation methods are compared,combined with the gear shifting mechanism of the pre-selected gears of the dual-clutch transmission,the evaluation method of the grouped pair comparison method is proposed.A representative jury was selected,and a subjective evaluation test was carried out on the noise samples based on the grouped pair comparison method proposed in this paper.The Pearman correlation coefficient was used to calculate the correlation coefficient of all members of the jury.Subjective scoring of the sample.The definitions and calculation methods of commonly used psychoacoustic parameters such as roughness and sharpness are expounded,and objective parameters are calculated.According to the characteristics of the pre-selected gears of the dual-clutch transmission,the analysis is carried out in two cases.The correlation of the subjective and objective parameters is calculated under the pre-selected gears and the non-pre-selected gears,and the sound quality evaluation model in the two cases is established by using the method of multiple regression.(3)Research on the transmission unit,and install a magnetoelectric speed sensor on the dual-clutch transmission housing.Using the torque fluctuation of the simulated engine,the set angular acceleration fluctuation uniformly rises from 0rad/s~2to 1500rad/s~2within 90 seconds.According to the data collected from the test,an index for evaluating the rattle strength is proposed.The rattle strength calculated by this method is compared with several commonly used methods for evaluating the rattle strength.The correlation between the method and the measured vibration data reaches 0.982,which is better than other rattle evaluation indicators,which verifies the accuracy of the rattle intensity index proposed in this paper.The rattle intensity of each idler gear in gears 4 and 5 was calculated,and the percentage of rattle contribution of each idler gear was calculated.(4)Based on the rattle sound quality evaluation model obtained from the vehicle test,combined with the rattle contribution ratio of the idle gear obtained from the bench test,the rattle evaluation model of the dual-clutch transmission under each pre-selected gear was calculated.The relationship between the impact strength of each idler gear and the subjective evaluation was obtained.