Automotive Friction Clutch Torsional Vibration Damper Characteristics And Parametric Analysis

At present, the design level of domestic clutch torsional vibration damper in automobile is lower. Domestic clutch production enterprises are generally lack of self-development capacity, most of them still remain in the imitation stage and the performance index matching are mostly lack of theoretical basis.With the development of automobile technology, automobile economy, comfort, reliability and other indicators put forward new demands, the future direction of development of the automotive vehicle ride comfort and driving smoothness, etc. require more stringent. Increasing clutch torsional vibration damper ability to extend its service life, simplifying operation become the current development trend of clutch industry. Aiming at some automobile type, establishing a perfect automotive driveline torsional vibration mechanical analysis model, systematic analysis of torsional vibration characteristics of friction clutch torsional vibration damper in automotive driveline and under the guidance of above theory, an effective design parameters selection based on calculation and matching for shock absorber, improving design and manufacture level of domestic clutch torsional vibration damper, etc. all of that are the one of the R & D subjects that domestic clutch enterprises need to overcome urgently.Supported by the funded projects named'Study of FAW DSP210J Friction Spring Clutch'of Automobile Industry Office in Jilin Province Industrial Information Bureau, with the actual production needs of Changchun Yidong Clutch Company, operating characteristics and performance parameters selection and matching issues of automotive friction clutch torsional vibration damper were systematically researched and analyzed. Automotive driveline torsional vibration mechanical analysis model was established, systematic comparative study of influence laws of different types of clutch torsional vibration damper for automotive driveline inherent characteristics were given, determining methods for the main parameters which can influence the torsional vibration damper performance were proposed. The determining methods studied for design parameters of the torsional vibration damper were effective and reasonable verified by experiments. This paper can provide a theoretical guarantee to improve the domestic automobile clutch working performance and product quality and also have practical value for raising the level of domestic production of such products.Vehicle driveline torsional vibration condition was analyzed with discrete torsional vibration analysis model of multi-freedom quality-stiffness-damping.17-freedom vehicle driveline torsional vibration mechanical model under driving state and idling state which is more closer to the actual system was set up. Normal driving state and idling state kinetics equations are unified. Based on the kinetics equations, contrast calculation and analysis on the inherent characteristics of vehicle driveline are carried out under two cases which are the torsional vibration damper existence or not and using different torsional vibration damper in vehicle driveline. The vehicle driveline torsional vibration excitation source and the main incentives viz. engine motivate torque are analyzed. With the actual measurement data to establish the engine torsional vibration excitation output curve and combined with the inherent characteristics of driveline, the critical speed problem was discussed, damping effect of the automotive friction clutch torsional vibration damper was evaluated also. Damping performance simulation analysis of automotive friction clutch torsional vibration damper in the automotive driveline was conducted after the virtual prototype for automotive driveline was established. Research and analysis results showed that:In the low frequency range, for the four-stroke six-cylinder engine, thrice main harmonic vector should be considered as the main motivation for torsional vibration. Although the clutch without torshional vibration damper has relatively simple structure, the use of torsional vibration damper has a positive meaning for torsional vibration system to reduce vehicle vibration and improve ride comfort. The automotive friction clutch torsional vibration damper has a clear vibration reduction ability and function of adjusting system natural frequency. Torsional vibration amplitude significant reducing after the input incentive goes through, which leading to reduce the appearance of the resonance conditions, can effectively decrease the driveline vibration and noise and improve the driveline performance of the kinematics and dynamics. Under idling state, traditional driven disc torsional vibration damper (shorthand as the CTD) has no obvious damping effect on the driveline after it and almost has no damping function on the part of driveline that before the clutch. Compared with CTD, the dual-mass flywheel torsional vibration damper(shorthand as the DMF) has obvious advantages on torsional vibration damping, has larger change on the torsional vibration inherent characteristics of vehicle driveline, can relatively lower driveline torsional vibration conditions, thereby increasing the life of the various components of transmission system. Particularly in the idle operating conditions, DMF damping the relative advantages of CTD is more significant.Using the theory and method of optimal design, rational selection and match of design parameters of clutch torsional vibration damper in automobile was discussed. Putting the traditional CTD damper as the research object, determining the torsional vibration damper stiffness and damping for the optimization design variables, confirming constraint conditions according to the actual production capacity, minimizing the maximum value of the transmission shaft torsional angle as the objective function, mathematical model of optimal design of CTD damper was established and after that, optimization calculation was carried on using ADAMS software optimization system with the optimal method of one-dimensional search. On that basis, selection principles and methods for DMF damper were proposed, in which, the emphasis is the optimization selection method for ratio of 2nd mass flywheel to 1 st mass flywheel. The results shows that:Rational performance parameters of torsional vibration damper can reduce the torsional vibration amplitude, improve the smooth operation of transmission system, improve the torsional torque fluctuation condition in transmission system thereby, so they have an important significance for improving torsional vibration conditions in transmission system. The parameters been optimized, the torsional vibration damper can further improve the torsional condition in the transmission system and has a positive meaning for reducing the torsional vibration burden of driveline. The optimal design methods for the torsional stiffness and damping of CTD damper and the ratio of 2nd mass flywheel to 1 st mass flywheel of DMF are practical and reliable calculating method for rationally selecting and matching the design parameters of the clutch torsional vibration damper in automobile. And the optimization ideas and calculation methods in this paper are not limited to the design of a certain type of vehicle and the specific clutch torsional damper, but applied to the design parameters selection of dry friction clutch torsional vibration damper in all types of passenger vehicles. Applications changing, the optimal mathematical model needs to be corrected only under specific circumstances. They are the new trial on improving the design methods of domestic automotive friction clutch.Combined with design experience of traditional CTD damper, based on theoretical guidance of the previous work selecting and matching major performance parameters of torsional vibration damper, the structural design and calculation analysis of the main components of DMF damper were carried out, three-dimensional model of the main components were given, elastic properties of the arc helix spring which is the core components in DMF and selecting method for design parameters were focused on discuss. After that the weak parts in DMF were strength analyzed and the torsional vibration performances of DMF were simulation analyzed. According to the theoretical analysis and simulation test, the results show that:Properties analysis of the arc helix spring and the determination methods of design parameters based on it are practical and viable for the R & D of DMF damper and also have great reference value for the R & D of other specifications of DMF products. Compared with the structure of CTD damper, the DMF have higher damping cost, inconvenient repairs, more difficult manufacture, etc. Because distribution radius of damping spring increases and radial centrifugal force and tangential deformation of the springs increases in the engine high rotation speed, wears of the springs are easy to be increased. Also, because of the difficult arrangement of DMF damper structure o, its further wider application is limited.Following test methods and standards of CTD damper, based on the existing test equipment in Yidong Clutch Company, some test equipments, methods and processes about test of clutch torsional vibration damper in automobile such as torsional vibration damper assembly torsional characteristics testing, resistance to high-speed testing, torsional vibration fatigue durability testing, etc. were presented. And traffic endurance testing of DMF damper was made also. The results showed that the designed torsional vibration damper is to meet the use requirements.In this paper, some new trials on the research and analysis methods in the friction clutch of domestic automobile manufacturing industry were made, which have larger reference value on optimal and improving design for clutch torsional vibration damper in automobile, improving the performance of automotive friction clutch and the torsional vibration working conditions of automotive driveline. And it can promote the further development of the clutch industry and will help domestic manufacturers derive a substantial economic and social benefits.