Quality Analysis Of Multipass Spinning Of Connecting Rod Bushing Based On Numerical Simulation

The connecting rod bushing is an important component connecting the small end and the piston pin of the engine connecting rod.It is usually manufactured by one power spinning process.With the further development of vehicle power system to high power,light weight and high compact trend,it is necessary to use multipass spinning process to further improve the bearing capacity and fatigue strength of the connecting rod bushing to meet the increasingly stringent working requirements.To understand and grasp the mechanism and rule of multipass spinning of connecting rod bushing is the key problem to research and develop this technology.Therefore,based on the ABAQUS finite element analysis platform,a three-dimensional finite element simulation model of the multipass spinning forming of the connecting rod bushing is set up,and the forming mechanism and the influence rules of the main process parameters on the forming process are analyzed.A three-dimensional elastoplastic finite element model of multi pass spinning of connecting rod bushing is established,which conforms to the actual spinning process and takes into account the calculation accuracy and efficiency.The key problems are solved,and the reliability of the model is verified.On this basis,compared and analyzed the forming quality of the secondary positive spinning and reverse spinning of the tin bronze connecting rod bushing.Compared with the reverse spinning forming,the workpiece caused the rotary end enlargement and the accuracy of the workpiece in the positive spinning is better,so the positive spinning is selected as the multi pass spinning forming of the connecting rod bushing.The stress strain and the geometric size of the workpiece during the multi pass positive spinning process of the connecting rod bushing are studied.The maximum stress and strain in the first pass forming process appear in the rotary wheel and the blank area(forming area),andthe position of the workpiece is easy to be enlarged,and the maximum position of the second channel stress is basically unchanged.As a result of the first plastic strain,the position of the maximum strain of the strain has changed,and the precision of the size and shape begins to become worse and the ellipse appears when it is spinning to the mouth position.Therefore,a certain machining allowance is needed in the mouth to ensure the precision requirements of the size and shape of the whole body.The final research reveals the main technological parameters,including the influence of the ratio of the different sub pressure,the forming angle of the rotary wheel,the feed ratio and the axial error on the inner and outer diameter of the workpiece after the multipass spinning of the connecting rod bushing.The results show that the lower pass ratio of the lower pass is beneficial to reduce the opening diameter of the first workpiece and improve the coating degree of the second pass formed end workpiece;the smaller rotating wheel forming angle and the larger feed ratio should be adopted in the first pass spinning forming,and the axial error is almost no more than the size of the inner and outer diameter of the first pass spin forming.In the second pass forming,with the increase of feed ratio,the accuracy of the inner and outer diameter of the workpiece is improved,and the size accuracy of the inner and outer diameter of the workpiece is improved by reducing the axis error of the rotating wheel as much as possible without the interference of the rotary wheel.These results can provide theoretical guidance for the selection and optimization design of the process parameters for multi pass spinning of connecting rod bushing.