Research On Axle Shaft Automatic Straightening Method Based On Electro-hydraulic Control

With the rapid development of automotive industry in recent years,the demand for axle shaft is growing.Axle shaft is an important part of the automobile transmission system,which mainly transmit the torque from the reducer to the driving wheel to drives the vehicle forward.In the production process of axle shaft,the bending type is complex and the deformation is large after axle shaft forging.In order to reduce the cutting allowance of the subsequent processing and the cost,it is very important to arrange the straightening process for the axle shaft.However,Due to the low efficiency,large energy consumption and other shortcomings,traditional manual straightening cannot meet the requirements of large-scale mechanized production.Although the hydraulic automatic straightening technology improve the work efficiency to a certain extent,but the precision cannot guaranteed.Servo automatic straightening has the high precision but the cost is very high.That's all seriously restricted the application and development of automatic straightening axle shaft forgings.The purpose of this dissertation is to solve the above problem,taking the axle shaft forging as the research object,combining with its own characteristics,and proposed a new method of electro-hydraulic control axle shaft automatic straightening to ensure precision and reduce the cost of equipment as much as possible.The main content of this paper are summarized as follows:(1)The physical characteristics of the bending deformation of the axle shaft are analyzed,including the types of bending deformation,the deviation of the neutral layer during the bending deformation,and the relation of stress-strain.(2)According to the characteristics of axle shaft forgings,a kind of clamping scheme using to axle shaft t forgings is designed.Firstly determining a detecting method of the axle shaft bending deformation,next to solve the maximum bending deformation and position.And through Solidworks to build down the pressure model,import it into ANSYS/workbench software for simulation,through analysis the impact on straightening quality with the supporting block size,head size and the shoulder,combined with a large number of simulation results to determine the optimal alignment parameters.(3)Formulated electro-hydraulic control straightening scheme,and study hydraulic system and electric control system respectively.Firstly,designing the hydraulic control circuit to control the pressure of indenter,the system transfer functions are established,drawing Bode to verify the stability of the system itself.And then derive the hydraulic circuit model in AMESIM,to analysis the impact size of indenter.Finally,making the control scheme of straightening the depressed displacement and analyses the accuracy control method.(4)Researching the control method of electro-hydraulic joint program,and make the manufacturing procedure of axle shaft automatic straightening technology.Experimental platform is built for experimenting the straightening pressure,experimental data are collected and analyzed,To verify the rationality of the electro-hydraulic straightening scheme.