Study On Fabrication And Accuracy Of Special Shaped Micro Punching Parts On-machine

With the demand of miniaturization products increasing,the research of micro machining technology has become a hot topic.Micro sensors and micro actuators,which are fabricated by micro machining technology,have been widely used in the fields of electronic information industry,automobile industry,medical devices and aerospace.Compared with traditional special machining and micro machining,micro punching technology have advantages of low cost,high efficiency,simple process and near net shape forming,etc.This technology is very suitable for batch manufacturing of micro size parts and has wide application prospect.In this paper,composite machine tool,including the function of micro electrical discharge machining(micro-EDM)and micro punching,has been set up.The control program was programmed based on NI LabVIEW software.Based on this experimental platform,a new fabrication and alignment process of micro molds on-machine was proposed.Meanwhile,the fabrication and accuracy of special-shaped micro punching part were studied experimentally.In order to ensure the accuracy of machining molds and the alignment of molds,a series of machining from the fabrication of micro molds to punching have been completed on-machine with no secondary clamping error.Micro-EDM was used as the technology to prepare micro molds.In order to verify the feasibility of machining special-shaped micro punching part,a special cross-sectional shape was designed.According to the machining characteristics of above mentioned special-shaped micro molds,a flexible and reliable processing was selected.Through the measurement of positional accuracy of motion platform,the alignment error of micro molds was analyzed theoretically.In the end,the precision of alignment was improved by changing the alignment process.Micro die and reversed electrode were fabricated by micro-EDM milling.Mirco punch was fabricated by reversed micro-EDM technique.The accurate discharge gap was obtained through trial experiments,so that the size of micro molds could be precisely controlled,and then the size of punching clearance could be controlled accurately.Experimental results indicate that the feasibility of fabricating complex cross-sectional shape micro parts on metal foils based on the proposed equipment and the corresponding process with high alignment accuracy.The size deviation of micro molds were within 2.5μm.There was no obvious warpage or distortion on the blanked parts which were fabricated under the 10μm punching clearance.In addition,all size deviations of punched hole were within 2 μm and the smallest size deviation of blanked part was within 2.5 μm.