The selection of electrical and mechanical parameters directly affects the machining efficiency. The final purpose of electrical parameter adjustment is to achieve the predetermined machining size, surface roughness requirements, and achieve higher machining efficiency. The adjustment of electrical parameters should consider: electrode thickness, electrode loss, machining surface roughness requirements, processing depth and other basic factors.
At present, the intelligence of NC EDM machine tool has been greatly improved. The machine tool has a large number of complete sets of parameters for the combined processing of various materials. The electrical parameters can be automatically selected and configured by inputting the process conditions according to the programming requirements in the programming process. In machining, the machine tool relies on Intelligent Control Technology (such as "fuzzy control" technology), which monitors and judges the state of machining gap by computer, automatically adjusts electrical parameters, maintains stable EDM, and achieves high machining efficiency. The electrical parameter database of advanced intelligent EDM machine tools can meet the general machining requirements, and greatly reduce the skill requirements for operators. The traditional EDM machine tool requires the operator to have rich working experience, and can flexibly configure the electrical parameters according to the machining requirements.
The intelligent control technology of machine tool is not omnipotent, so the function of manual adjustment of electrical parameters cannot be ignored. Especially in some special processing occasions such as deep hole machining and large inclined hole machining, it is necessary to adjust electrical parameters manually. When adjusting electrical parameters, priority should be given to adjusting pulse interval, pulse width, processing current, etc. for special materials processing, reducing pulse interval and increasing processing current are beneficial to improve processing efficiency. However, in the case of unstable processing, a higher processing efficiency can be obtained by properly selecting a larger pulse interval.
Pulse width has a great influence on processing speed, but some technicians have misunderstandings about the influence of pulse width on processing speed. Some think that increasing the pulse width can improve the processing speed, while others think that reducing the pulse width can improve the processing speed. In theory: when the pulse peak current is constant, the pulse width increases, and the processing speed increases accordingly. When the pulse width increases to a certain value, the processing speed reaches the highest. After that, if the pulse width continues to increase, the processing speed will decrease. But in the actual production, the pulse width must have a certain understanding. According to a large number of processing examples, it must be pointed out here that the pulse width corresponding to the maximum processing speed is often very small, so the electrode loss is large, and it is not suitable to be used in many cases. In the actual processing, the standard of machine tool selection generally takes into account the reduction of electrode loss. Then, in the low loss machining standards, if the pulse width is increased, the processing speed will inevitably decrease, and if the pulse width is reduced, the processing speed will be improved to a certain extent.
