Cutting Machine Introduction

Medium-speed Wire cut Electrical Discharge Machining (MS-WEDM) belongs to the category of reciprocating high-speed wire EDM machine tools. It realizes multiple cutting functions on high-speed reciprocating wire EDM machine tools and is commonly known as "medium-speed wire cutting". Medium-speed wire technology points out here that the so-called "medium-speed wire cutting" does not mean that the wire speed is between high speed and low speed, but a compound wire cutting machine tool, that is, the wire cutting principle is to use high-speed (8-12mm/s) wire cutting during rough machining and low-speed (1-3mm/s) wire cutting during fine machining. In this way, the work is relatively stable and the jitter is small. Multiple cutting can reduce the error caused by material deformation and molybdenum wire loss, so that the processing quality is relatively improved, and the processing quality can be between high-speed wire cutting machine and low-speed wire cutting machine. Therefore, it can be said that the "medium-speed wire cutting" mentioned by users is actually a reciprocating wire EDM machine that draws on some processing technology of low-speed wire cutting machine and realizes stripe-free cutting and multiple cutting. The medium wire technology has been found in practice that the first cutting task in multiple cuttings is mainly high-speed and stable cutting. High peak current and long pulse width can be used for high current cutting to obtain higher cutting speed. The second cutting task is fine finishing to ensure the processing size accuracy. Medium standards can be used to make the roughness Ra after the second cutting between 1.4 and 1.7μm. In order to achieve the purpose of fine finishing, low-speed wire running is usually adopted, with a wire running speed of 1 to 3mm/s, and the tracking feed speed is limited within a certain range to eliminate the round-trip cutting stripes and obtain the required processing size accuracy. The third, fourth or more cutting tasks (currently the medium wire control software can achieve up to seven cuttings) are polishing and finishing. The minimum pulse width (currently the minimum frequency can be divided to 1μs) can be used for finishing, and the peak current varies with the surface quality requirements. In fact, the finishing process is a kind of electric spark grinding, with very little processing and will not change the size of the workpiece. The wire running method can use low-speed wire running and limited speed feeding like the second cutting. During the processing of medium wire technology, attention should be paid to deformation treatment during multiple cuttings, because during the online cutting of the workpiece, with the effect of the original internal stress and the influence of the processing thermal stress generated by spark discharge, non-directional and irregular deformation will occur, making the subsequent cutting thickness uneven, affecting the processing quality and processing accuracy. Therefore, different processing allowances should be reserved according to different materials to allow the workpiece to fully release the internal stress and completely twist the deformation, so that there will be enough allowance for fine cutting in the subsequent multiple cuttings, so that the final size of the workpiece can be guaranteed.