Processing Technology of Three-axis CNC EDM Machine

The machining technology of the three-axis CNC EDM machine is based on years of practical experience in mold processing, and the independently developed three-axis linkage EDM technology, using a number of new technologies to overcome the lack of a single-axis EDM function, while Easy to operate, is the current development direction of EDM technology.

1 Three-axis CNC EDM machine performance characteristics (1) Triaxial linkage side repair. This machine tool is designed with two side-retouch graphics (square and round) and two ways (bottom and top). Rectangle rectangles adopt a flat bottom side repair scheme, and round or multi-surface ovals adopt a flat bottom round repair scheme. In the side-repair process, the tool electrode moves at an angle to the workpiece. At this time, the tool electrode moves from the middle to the outside (X direction and Y direction) and from the top to the bottom (Z direction), and the CNC automatically controls, that is, the three axis linkage. . This kind of movement is not easy to deposit carbon, and it is easy to discharge chips and exhaust. It will not cause arc drawing, high production efficiency, uniform side and bottom surface roughness, and reduces labor intensity compared with single-axis translational head EDM. When machining the X-axis direction cavity, the X-axis can also achieve three-axis linkage side repair.

(2) The X-axis side-to-side machining has the unique advantages of high mold clamping precision, and the productivity can be improved by 20% compared with the Z-axis.

(3) Self-propelled knife raising. The etched materials introduced in the basic principles of EDM must be eliminated in time to reach the balance between production and elimination. Otherwise, they cannot work normally and stably, which will affect the processing efficiency. In general, the timing of knife lifting is regardless of whether or not there is no corrosion in the cavity. The so-called self-propelled raising knife is that when the elimination of the erosion material in the cavity is greater than that produced when the discharge is stable, it does not lift the blade; when the erosion of the cavity is larger than the discharge, the balance is broken, and at this time, the machine tool automatically lifts the knife and utilizes the work. The effect of liquid suction is to discharge the excess etched material and reach the equilibrium or the discharge is greater than the time when it is generated, and the lifting of the knife is stopped and the efficiency is improved.

(4) When the EDM machine is working, it is easy to cause fire due to false arcing due to arcing or poor discharge of erosion materials. When there is arcing or false short-circuit phenomenon in the line cavity, resistance is generated between the electrode and the workpiece, which is in a state of neither short circuit nor open circuit. The energy of the power supply continues to release thermal energy in the electrode and the workpiece, and the temperature of the tool electrode becomes higher and higher. And even kerosene caused fire. For safety, the machine adds special control in the control circuit. When a pull arc or false short circuit occurs, the pulse power is cut off immediately, and the supply of energy to the cavity is stopped. The temperature of the electrode will not continue to increase, reducing the occurrence of fire. may.

(5) Energy saving. The machine tool has reduced the current-limiting resistance of the low-voltage circuit in the circuit, that is, the heat generated by the current-limiting resistor of a 50A power supply is reduced by nearly 2KW, which reduces the energy consumption and saves more than 20% of power consumption compared with similar power sources.

(6) The general pulse power in the cavity processing is to send a series of pulses to the gap. Due to the complex situation in the gap, the breakdown is not the beginning of each pulse, but the late breaking time, which causes the spark The effective pulse width is narrow, and the randomness of the pulse is narrowed by approximately 30%. An unstable pulse with an effective pulse width increases the loss of the electrode of the tool. This machine adopts a complete low-voltage pulse method after high-voltage breakdown, and the pulse width is equal. Practice has proved that this pulse method further reduces the loss of the tool electrode, the roughness of the processing surface is uniform, and the tool electrode end surface loss is almost zero.

(7) The use of one electrode for rough finishing saves the manufacturing time and cost of the two electrodes, eliminates the trouble brought about by the correction of the finishing electrode, and shortens the time for mold making.

2 Conclusion Since there is no side repair function for single-axis EDM machine tools, due to the relatively large tool electrodes, two electrodes are used, ie, rough machining electrodes and finishing machining electrodes. Because the three-axis EDM machine has a side repair function and low tool electrode wear, one electrode can be used for finishing.

The machining technology of the three-axis CNC EDM machine is a technical advancement of electric machining. With the promotion and application of this technology, it will also be widely used in the EDM industry.