Study On The High Strength Lightweight Automobile Drive Shaft Assembly

At present, the theme of development of the world automobile industry is：energyconservation, environmental protection, safety, comfort, intelligent and network, amongthem, energy conservation, environmental protection receive most attention because theyare closely related with people’s life. With continuous research,the scientific research elite inthe field of automobile in China find that, reduce the weight of the car itself and improve thesafety of the automobile parts is the most feasible,economic and efficient way to solve thisproblem, so the high strength lightweight materials which meet the requirement have beenwidely used, the micro alloy high strength low carbon steel has received widespreadattention because of its rigidity and good resistance to impact, high elastic modulus andfatigue strength[1,2]. Each big factory in our country also had applied lightweight technologyin high strength steel body and outer covering parts, aluminium alloy engine cylinder block,the steering wheel skeleton and suspension parts, etc, but it is less applied on automobileshaft parts, which makes it become a weak part in the process of processing andmanufacturing for vehicle[3], in reaction to the phenomenon,the key point of this paper is theapplication of high strength lightweight technology in automotive transmission shaftassembly.The research object of this paper is transmission shaft assembly of J5P, J5M and J6series trucks of faw, replace existing B440QZR and B480QZR shaft axis tube material withhigh strength, low cost and lightweight materials B600QZR and B700QZR,to product highstrength lightweight shaft assembly. This research of the four kinds of transmission shaftassembly structure mainly conduct on the three aspects of the research, microstructure andmechanical properties, the finite element analysis of automobile transmission shaft axis tubeassembly, analysis of static and fatigue failure of automotive drive shaft assembly.Theresearch found that the improved shaft tube materials B6000QZR and B700QZR havesmaller grain size than the original axis tube material B400QZR and B480QZR, and theprecipitation of the second phase particles is more and uniform, The research of the materialsof high strength lightweight transmission shaft tube on the automobile and the analysis ofassembly fatigue performance.The main reason is adopting the controlled rolling andcontrolled cooling process and addition of Nb, V, Ti micro alloy elements; Mechanical performance analysis shows that tensile fracture mechanism of the new developed shafttube materials B6000QZR and B700QZR are all ductile fracture and quasi-cleavage fracture,which prove that they are all with high strength and good toughness；Finite element analysisof automobile transmission shaft by using software ABAQUS found that B6000QZR andB700QZR occurs yield in the set under the yield torque, yield strength can satisfy therequirements of the research theory, and had great increase compared the production shafttube material strength； Through the fatigue failure experiment on drive shaft assembly withthe application of new shaft tube material proved that the failure of shaft assemblyB6000QZR and B700QZR sample mainly appear in the flange fork and cross shaft parts,when the failure occurred in the shaft tube parts, fatigue origin starts with the root of theflange fork eventually led to the shaft tube welding crack, rather than the fracture of shafttube itself, which means the microalloy high strength low carbon lightweight shaft tube westudied compared to the production of shaft tube has much ascension on the strength, shafttube is not the most vulnerable parts of the drive shaft.