Research On Key Technology Of Lateral Knurled Camshaft

The assembled camshaft adopts the method of parts separated processing and assembly,which breaks through the traditional overall design and processing mode of camshaft.It has the advantages of flexible material matching,good product performance,high production efficiency,easy to achieve flexibility and automated production,and has become a new direction for the development of the camshaft manufacturing industry.The connection of split parts was the key technology of assembled camshaft.For transverse knurled camshaft,domestic research focuses on the influence of various parameters on the connection strength.The theoretical calculation of connection strength was relatively less.The determination of process parameters mainly depends on experiments,which has many problems such as blindness,long design cycle and high cost.In this paper,by cutting and observing the two states before and after the failure of the transverse knurled camshaft connection,the connection state and the failure process was analyzed to establish a mechanical equivalent model.The static torque calculation was divided into spline connection torque calculation and interference connection torque calculation.Combined with the actual situation of transverse knurled connection,the correction coefficient K₁and K₂were introduced.According to the strength calculation formula of spline connection and interference connection,and the theoretical calculation formula of the maximum static torque that the transverse knurled connection can bear is derived.The relationship between the parameters and the static torque connection strength was determined.Taking the camshaft of an automobile engine as an example,the model of the horizontal knurled camshaft is simplified by analyzing the structural characteristics of the horizontal knurled camshaft,and the assembly process and torsional failure of the transverse knurled camshaft were simulated by ABAQUS software.The relationship between the main parameters and the press force and the static torque strength was analyzed,and the relationship between the parameters and the static torque in the theoretical calculation formula of connection strength was verified.At the end of this paper,a group of optimal machining parameters were determined based on theoretical calculations and simulations,and the machining and assembly of the camshaft were completed.By designing a special fixture for fixing the cam and the shaft tube,the torque experiment platform is used to conduct a static torque destruction experiment on the camshaft.The experimental results were compared with the simulation and theoretical calculation results.The larger torque deviations in the experiment were analyzed.The research results show that the combination of theoretical calculations and simulations can be used to determine the optimal combination of process parameters and perform experimental verification to optimize and design the product,thereby reducing design workload and design costs,and shortening the product development cycle.