Secondary cutting process of the hottest high-spee

The secondary cutting process of high-speed WEDM

compared with high-speed WEDM, the advantages of two high and one low (high efficiency, high precision, low surface roughness value) of CNC low-speed WEDM are well known. Due to the influence of the electrode wire loss, the structure and accuracy of the mechanical part, the open-loop control of the feeding system, the change of the conductivity of the emulsion in the processing, the temperature change of the processing environment and the processing characteristics of the machine itself (such as fast wire conveying speed, more vibration sources, large wear of the guide wheel), the high-speed wire cutting machine has a significant gap with the low-speed wire cutting machine in terms of processing accuracy, process indicators, degree of automation and so on. However, the price gap between the two is more than ten times. How to use the high-speed wire cutting machine, through the adjustment of process parameters, the change of operation methods and the adjustment of cutting procedures, to improve the technical indicators of the workpiece to be processed, so as to make it close to the processing effect of the low-speed wire cutting machine, is a problem of great concern to enterprise operators and technicians. Because this can not only achieve the ideal process effect, but also greatly reduce the capital investment and improve the economic benefits of the enterprise

the fundamental reason why the low-speed WEDM can achieve good machining accuracy and other technical indicators is the use of multiple cutting processes. Therefore, studying the multiple cutting process of high-speed WEDM is an important way to improve the processing quality of high-speed WEDM. The following describes how to use the secondary cutting process to improve production efficiency, reduce the surface roughness value of the workpiece, improve its geometric dimension accuracy, and extend the service life of the workpiece

(1) analysis of one-time cutting process of high-speed wire cutting machine

taking the processing of punch and concave dies of blanking die as an example, when the one-time cutting process of high-speed wire cutting machine is used to complete the mold processing, in order to obtain better processing accuracy and surface quality of the workpiece to be processed, it is generally used to reduce the pulse width parameters of high-frequency power supply, reduce the number of power amplifier tubes, and control the output current at 0 8～1. 2A. At this time, the processing speed is low. This cutting method, which ensures the accuracy and surface quality of the machined workpiece at the cost of reducing the machining efficiency, is effective for the workpiece with a machining height of less than 10mm. However, for workpieces with a height of more than 30mm, because the emulsion is not easy to enter the machined surface, the cooling effect is poor, coupled with the high temperature effect of the arc between molybdenum wire and the workpiece, and the workpiece surface is prone to sintering, etc., the surface quality of the workpiece after machining is not high, and a rough hardened layer appears, and the surface roughness is ra1 6～3. two μ M, and it is not easy to clean

(2) analysis of secondary cutting process of high-speed WEDM

the first problem encountered in secondary cutting on High-speed WEDM is how to program. If the processing program of the primary cutting process is based on the punch size, the die program is compiled according to the conventional fit clearance of the die. The secondary cutting cannot be programmed according to the routine. After many process analyses and repeated experiments, and considering that the repeated positioning accuracy of the machine tool during the secondary cutting is 2 μ M and the discharge gap of secondary cutting. Our experience is that when the secondary cutting method is used, the programming should be 5 times smaller than the single side of the die size compiled by the primary cutting method μ m。 For example, the fit clearance of the punch and die of a stamping die is required to be 0 01mm, the male die shall prepare the cutting program according to the drawing size, and the cutting program of the female die shall be programmed with a zero to zero gap

the purpose of the first cutting in the second cutting is to improve the processing efficiency, so when the first cutting is carried out, the pulse width of the high-frequency power supply and the number of power amplifier tubes can be increased, and the processing current parameter can be 1 0～1. 5A, so that the demand and technical requirements for plastic granulator are also constantly improving. One cutting is completed at a higher speed and returns to the cutting starting point

the essence of the second cutting process is to improve the machining accuracy and surface quality of the workpiece. It is a process of low corrosion discharge. Therefore, the cutting should be carried out when the pulse width of the high-frequency power supply is reduced, the number of power amplifier tubes is reduced, and the tracking current is adjusted to the same running speed of the machine tool and the idle speed

in practice, the second cutting must be carried out before 3. The key step of nano metal materials is tightening. The main factor affecting the cutting quality of high-speed wire cutting machine is the vibration of electrode wire. The main causes of vibration are the dynamic imbalance and radial jump of the wire storage cylinder, the axial and radial movement of the guide wheel, the tension of the electrode wire, etc. Since this paper describes the discussion of cutting method based on the existing equipment, the vibration source analysis of equipment factors can be excluded, and only the tension of electrode wire can be analyzed. The electrode wire is aged under the action of high temperature caused by high-speed movement in machining and discharge in cutting, which makes the electrode wire lose, the diameter decreases, the tension decreases, and the amplitude increases. Therefore, wire tightening is the key link in the second cutting. By tightening the wire, the tension of molybdenum wire is increased and the vibration of molybdenum wire in the cutting process is reduced, so as to improve the accuracy and surface quality

after the secondary cutting process is adopted, the machined workpiece not only improves the dimensional accuracy, effectively removes the surface stains, feels smooth without burrs, and reduces the surface roughness, but also increases the hardened layer of the cutting surface due to the discharge effect during the secondary cutting and the effective cooling of the emulsion, thus greatly improving the service life of the die. Cut 100mm on 25mm thick steel × Although D is selected for 100mm square hole, it reflects the 6-character k7725e high-speed wire cutting machine. Different cutting methods are applied, and its process parameters and processing effects are shown in the table below. The comparison of process parameters and processing effect

it can be seen that the work efficiency of the secondary cutting method is increased by 4%, and the surface roughness is also significantly reduced

to sum up, it is completely feasible to adopt the secondary cutting processing technology, as long as the programming is correct, the parameter selection is reasonable, and the operation is appropriate, so as to improve the processing efficiency and technical indicators since "1035". At present, this method has been used in the mold of high-power transmitting tubes and various types of switching tubes developed by our company, and has achieved satisfactory results. (end)