Liquid treatment in precision machining
Edm is carried out in working medium.The insulating property of working fluid plays a role of deionization in the process of pulse discharge, accelerating the cooling of the electrode and workpiece during processing, and making the electroerosion product levitate and discharge out of the discharge gap.
The method of punching and pumping is often used to discharge slag in edm.However, the uneven flow field results in uneven chip accumulation, resulting in concentrated discharge and secondary discharge, which greatly affects the flatness and roughness of the workpiece, resulting in uneven discharge gaps.And the strong scour will cause the electrode edge Angle abnormal loss.Therefore, the precision machining usually adopts the liquid processing method of no flush and oil immersion processing, which depends on the action of lifting the knife to remove the chip.
For example, when the main shaft is fed with high acceleration, the suction effect is generated, so that the waste, tar and waste gas existing between the electrode and the workpiece can be effectively discharged.
The quality of working fluid in precision machining is also very important. At present, there are many types of special working fluid for edm. The key point is that the viscosity is low and the finishing performance is better.