Research On Optimization Of Transmission Housing Bolt Tightening Process

The transmission is a mechanism used to change the speed and torque,to achieve reverse gear,neutral gear and change the speed of the car.Its quality has an important impact on the transmission performance and driving safety of the car.Sealing is one of the important indexes to evaluate the assembly quality of transmission.The poor sealing of the transmission will cause the leakage of lubricating oil and coolant,which will not only reduce the service life of the transmission,but also lead to energy waste,environmental pollution,and even affect the transmission performance of the vehicle and endanger the safety of the occupants.The tightening of transmission housing bolts is the most important part of the assembly process that affects its sealing.It is of great significance to study the tightening process of transmission housing connecting bolts to ensure the sealing of the housing joint surface.Taking the tightening process of connecting bolts of X-type transmission housing as the research object,the finite element simulation analysis method is used to simulate the tightening process of bolts in this process,and the existing bolt tightening process is optimized for the specific irregular joint surface of X-type transmission housing.The main research contents are as follows :(1)The tightening process of the transmission housing bolt and the commonly used bolt tightening control method are studied.The sealing structure,sealing mechanism and sealing failure form of the joint surface are studied,and the main factors affecting the sealing performance of the joint surface are analyzed.(2)Based on SOLIDWORKS three-dimensional modeling and ANSYS Workbench finite element simulation software,the finite element model of the bolt connection of the transmission housing is established,and the finite element simulation analysis of the existing bolt tightening process of J company is carried out.By extracting the residual preload of the bolt group and the stress value on the sealing gasket after the tightening is completed,the hidden danger of the sealing of the transmission joint surface after the assembly of the existing bolt tightening process is explored.(3)In view of the quality problems existing in the existing bolt tightening process,the tightening torque,tightening tools,tightening procedures and tightening methods of bolt connection are optimized and analyzed by using finite element simulation and DOE test method,and the best tightening process of X-type transmission shell connection bolt is obtained.(4)The optimized bolt tightening process is verified by trial assembly,and the SPC control chart analysis of the verification result data is carried out.The analysis results show that the process optimization is feasible and reliable,and can meet the sealing requirements of transmission assembly.