Experimental Study On High Efficiency Machining Of HSWEDM

High speed reciprocating wire electrical discharge machining tool is independently developed by China,which has unique advantages in machining large taper and high thickness parts.WEDM relies on the instantaneous high temperature generated by pulsed electrical spark discharge between the two poles to process the material,which can process difficult mechanical materials without being affected by the mechanical properties of the materials.It has been widely used in molds,cars and other fields.In order to further improve the machining efficiency of HWEDM and expand its application field.In this paper,the high-efficiency machining is studied in the following aspects,the main contents are as follows:(1)A closed-loop constant tension adjustment device was built.In order to improve the processing stability of electrode wire under the condition of high energy,The constant tension adjusting device of electrode wire based on ARM microprocessor was built,which reduced the tension change of electrode wire by 88%-90%,reducing the probability of wire breakage,and greatly improved the stability of processing.(2)The cooling mode between poles in HSWEDM was studied.The causes of burn on the surface of workpiece under high current were analyzed.Two cooling methods,physical gasification cooling and chemical decomposition cooling,were put forward,and the important role of kerosene chemical decomposition cooling in improving the discharge state between electrodes was explained by theoretical analysis.(3)The method to reduce the burn of the workpiece surface was studied.Adding a certain proportion of kerosene to the working medium,the heat absorbed by kerosene chemical decomposition under the same volume was 24 to 211 times of the heat absorbed by working liquid gasification.When1% kerosene was added to the working fluid,the burn area of the workpiece surface reduced by 92%,and the machining efficiency increased by 23%.(4)This paper analyzed the electrical parameters of HSWEDM in high efficiency machining.Under the condition of high energy,two processing methods of large pulse width and small peak current,small pulse width and large peak current were used for experiments.The experimental results showed that the machining efficiency is 20% higher when using the large pulse width and small peak current.(5)Using Design Expert software to optimize the processing parameters of large pulse width and small peak current,the mathematical regression equations of processing efficiency and surface roughness on each parameter were obtained,and the optimal experimental parameters were obtained:The pulse width is 48?s,the pulse is 56?s,the peak current is 24 A,and the speed limit is 100 steps/s.The machining efficiency of the optimized parameters is increased by 35.7% and the surface roughness is reduced by 23.9%.