Solution of mould outside precision work

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  • source:WEINBERG CNC Machining
Mould outside precision work is a mould fail in treatment very good one of settlement difficult problem, also be intensity of mould benchwork labor one of big, matters that become a mould to machine bottleneck. Special report in hardness mould of bigger metal, Die Casting undertakes assembly a process finally. Our country still is given priority to with manual and abrade polish at present, not only not stable, cycle grows quality, and worker work environment is poor, restricted our country to cast a mould to develop to higher administrative levels. Complex to the mould model antrum and the curved surface finish machining of a few slit, traditional machine treatment method already cannot be competent, must adopt the technology measure of other, if electrochemistry or electrochemistry machinery make processing technique solely. As the ceaseless development of science and technology, the treatment craft demand of all sorts of moulds is higher and higher. The rate that raises mould polish and quality make workmanship of our country mould reachs world advanced level, already made the main task of no time to delay. In technology of mould outside precision work, main can divide for two much, namely technology of traditional finish machining and technology of blame convention precision work. Technology of traditional finish machining basically is the mechanical finish machining that rises with abrade polish is given priority to and developing now by hand; Blame convention precision work basically includes chemical polish, electrochemistry polish, electroanalysis machinery of abrade, electrochemistry rectifies treatment, ultrasonic treatment, magnetism shedding to change solely technology of polishing, laser polish and electric spark polish. Main treatment method is mixed below the tool undertakes introductory. It is general still need to undertake the following improve measure below the premise that assures precision of machine tool machinery: 1, must add unit of spacing of outfit electrode silk; Device of electrode silk spacing is similar to low speed to take the seal wire that uses on silk implement, have fixed position effect to electrode silk, raise electrode silk to be in the stability of dimensional position, be in at present " in walk along silk " use on the machine tool more general is garden club structure. Garden good stuff has diamond of He Jujing of gem of hard alloy, man-made, look from service life get together the effect of brilliant diamond is best; 2, add the yarn tension device that install constant; Constant main effect of yarn tension device is to be in macroscopical go up the stability that commands electrode silk pulling force, achieve the effect that maintains electrode silk to achieve the tigidity that raises electrode silk in the stability of dimensional position thereby, at present yarn tension device basically returns constant is to use structure of heavy weight type, the in the cut when big ply cut stability after adding the yarn tension device that install constant can rise greatly. 3, accomplish silk fast adjustable; The particular case of frequency of the cut ply with different basis of machine tool need, cut undertakes silk fast adjust, at present commonly used is frequency control. 4, carry sheet piece the machine implementation setting to all sorts of treatment parameter and self-adjusting; Control system must can pass issue a sheet piece opportunity is right all sorts of treatment parameter if: Cut frequency and direction, every time nap quantity, every time speed of silk of all sorts of parameter of power source of the pulse when cut, carry even size of electrode silk tension undertakes self-adjusting; 5, system of configuration closed-loop control; Had had at present " in walk along silk " the precision that line cut machine tool configured closed-loop control system to improve treatment. 1.

Manual and abrade polish this method is the main method that traditional pattern finish machining uses, also be one of methods that our country still uses extensively at present. This method does not need special device, adaptability is stronger, basically rely on the experience craft level of handlers, but efficiency is low (the 1/3) that occupies whole pattern cycle about, and worker labor strength is great, quality is not stable, restricted treatment of our country mould to develop to higher administrative levels. But current socioeconomy technology develops a condition, still cannot wash out this kind of process instrumentation completely temporarily. 2.

Polisher of digital type mould sees the story of polisher of a number recently, tool of this kind of polish uses digitlization control, digital type shows and control craft parameter, wheelhead of stock a complete set of reachs abrasive, semi-automatic polish, have volume small, use convenient good point. Its craft characteristic basically has have level off function, most can the moire length of level off is 75mm. Compare with manual polish photograph, effect raises one times, quality raises an amount level. Quality is stable, repeatability is good. Use range: Material: All sorts of mould material, include cast steel, forged steel, aluminium alloy to reach zincic radical alloy. Mould surface dimension: 100 × 100 - 1, 500 × 3, 000mm. 3.

This polish tool uses ultrasonic mould polisher the principle with fast abrade vibration undertakes power source of pulse of high frequency electric spark and ultrasonic polishing. It can finish general polish tool (report grinds flexible shaft to wait) what extend hard is narrow groove, narrow seam, the polish of the labyrinthian place such as edge, horn, edges and corners does not collapse after polishing, do not affect the precision of the mould. This tool can solve an user to because workpiece form is complex,achieved polishing to ask hard in the past this one difficult problem. And shortened polishing time improved work efficiency. Be more than Ra1 to raise surface roughness.

The polishing speed of 6 workpiece, the tool uses ultrasonic and appropriative high frequency narrow the pulse power source of electric current of pulse height value is compound undertake polishing, mix by the concussion of ultrasonic of electric pulse corrode at the same time action at workpiece surface, can reduce its surface roughness quickly, very effective to the rough hard surface after all sorts of special treatment. Use this tool to undertake polishing, can be opposite quickly polish of rough surface plastics, do not accept restriction of hardness of workpiece appearance, material, do not have a requirement to primitive surface surface roughness, effect is taller. 4.

Regard a mould as the method of semifinishing machining and finish machining with technology of high speed milling. From 80 time since, as the maturity of technology of high speed milling and development, mould face treatment already used method of this treatment craft more, the technology that has mould face finish machining and polish with EDM already drop off, because,this basically is: Except have inside of acute angle model antrum and extremely narrow and deep model outside antrum, milling of basic usable high speed replaces EDM to machine; Use high speed milling to machine mould face to be able to save 25% ～ than EDM treatment 60% treatment man-hour; Of high speed milling model face face quality is good, the appearance that can avoid EDM to machine a likelihood to appear is imperceptible model grain; High speed milling can machine good appearance of 45 ～ 60HRC, surface roughness of face of mill of essence of life can amount to Ra=0.

63mm, reduce manual polish man-hour; Dispense with EDM machines the production link of electrode, shorten significantly patternmaking is periodic. "High speed milling " the mainstream technology instrument that already made mould semifinishing machining, precision work in Germany and Japan, our country is developing actively in. 5.

Electrochemistry and electrochemistry machinery make treatment solely. Electrochemistry reachs his compound smooth whole processing technique basically is the electrochemistry positive pole that relies on metallic workpiece deliquescent principle will machine, belong to ionic purify. And contact treatment because of dispute, be out of shape without treatment layer, degenerative layer and leftover stress; The tool is not had wear away, OK and long-term applying; Do not produce flash and burr. It replaces raceway to exceed energy technology, can improve raceway surface quality substantially, improve and make up for grind treatment blemish, surface roughness, ripple spends those who reach circularity and raceway to exceed hind of essence of life " tierce " the precision reserve after photograph take rough measurements is changed is in 80% above. Use electrochemistry machining to be able to raise 5 times above than the life of general superfinishing. Although here is with bearing exemple, but in the finishing treatment that this technology is likewise complete OK to mould surface applying. CNC Milling