An automotive powertrain suspension system refers to an elastic connection system between a powertrain (engine, clutch, transmission, and accessories) and a frame or body. With the development of the automobile industry, the energy utilization rate is continuously improved, and the automobile design is developing toward the direction of high torque, light weight and economy. The small, high-power engine and lightweight automobile materials are continuously used, so that the powertrain is transmitted to the vehicle body. The increase in vibration amplitude greatly deteriorates the vibration characteristics of the car, which seriously affects the ride comfort and interior noise of the vehicle. Therefore, the design of the powertrain suspension faces more problems and is becoming more and more important. 10 Fasteners are a general term for a class of mechanical parts used to fasten two or more parts (or components) into one piece, usually including fasteners, studs, screws, and nuts. Fasteners are a common form of powertrain suspension fasteners and an important part of the powertrain suspension system. The design form, model and material grade of the fasteners will affect the connection effect of the fasteners, which are manifested by the slip, looseness and breakage of the fasteners. The root cause of the fastener problem is that during the driving process, different load conditions cause the clamping force of the fastener to decay. 2 How to design the tightening torque of the fastener to achieve the problem that the fastener will not appear in the service life of the car is an important issue to be considered. When the fastener is tightened by the torque method, the tightening torque is determined according to the relationship between the tightening torque and the clamping force, so that a more accurate relationship between the two is obtained. Sex, security and the quality of the connection are important. Typically, 50% of the tightening torque is used to overcome the frictional torque of the fastener support surface, 40% to overcome the frictional torque of the threaded mating surface, and only about 10% to form the final preload. H is the ultimate goal in designing the lightest and safest engine mount system today as car lightweighting becomes a trend. In the early stage of engine suspension and fastener design, the finite element simulation analysis is used to meet the strength durability and fastener anti-loose requirements, but in the later bench test and road test, the engine suspension bracket cracks or even breaks. The phenomenon that the fastener is loose and broken sometimes occurs. There are many studies on the relationship between the clamping force of the fastener and the tightening torque and its calculation method, the effective radius of the fastener support surface, and the like. Internal Combustion Engine Engineering, 2004, Li Weirong. Research on anti-loose technology and test methods for threaded fasteners. Anhui: Hefei University of Technology, 2005. Wang Ning, Li Baotong, Hong Jun. Factors affecting the effective radius of the bolt bearing surface. Journal of Xi'an Jiaotong University, 2012, 46(4): 132436. Chen Chengjun, Yang Guoqing, Chang Dongfang. Research on elastic interaction of bolt set connection based on finite element method. Journal of Wuhan University of Technology, 2011, Yin Yihui, Yu Shaorong. Bolt joint pre-tightening force and design method of allowing external force based on finite element calculation. Journal of Mianyang Normal University, 2011, (Editor Wu Xiaoying)
Geotextile Geotube,Dewatering Geotube,Pp Geotube,High Tensile Geotextile Geotube
Shandong Jinruixiang Geotextile Material Co., Ltd , https://www.jrxgeosynthetics.com