Processing technique of imperceptible electric spark is made in miniature mould apply mediumly

2% . Alleged miniature mould, if be mixed from dimension,try on production precision demarcate, criterion miniature mould has the following feature: Figuration makes a measure tiny, generally speaking bulk is controlled for 1mm3; The microcosmic dimension of figuration arrives from a few micron hundreds of micron, mould surface surface roughness Ra ≤ 0.

1 μ M, the production precision ≤ of the mould 1.

0 μ M. Miniature mould does not point to the mould with tiny bulk certainly, there is the share of small structure feature on the mould that accumulates roughly, this one part also can call miniature the pattern, the part of small small-sized antrum of structure of this kind of mould, can machine on the module of a minor volume, embed small module as a module next in old pattern, this facilitates not only the imperceptible treatment of tiny mould, and can undertake setting piece change, in order to improve the life of integral mould. The production difficulty of miniature mould depends on the treatment of small small-sized antrum or tiny and concave and convex structure, general machining method cannot machine the part with too small size, machine the miniature mould of small structure dimension very hard that is to say, and dimension precision and exterior surface roughness the requirement of mould of short of miniature, especially the stress of machining is greater to influence of miniature mould treatment. Although already developed imperceptible turning machine tool, imperceptible milling machine tool and imperceptible grinding machine tool at present, but have its limitation, suit the miniature antrum treatment of miniature mould very hard. And those who suit miniature mould treatment basically is non-traditional machining technology, include to make processing technique of technology, imperceptible electric spark wait solely. The new-style optical making technology that develops in recent years -- LIGA technology, it is the tie that deepness X ray cuts corrode, electroform to shape to wait for a technology with plastic mould, it is the spare parts processing technique of small structure of a kind of high accuracy, but LIGA can machine columnar small structure only, the process instrumentation that regards miniature as the mould also has certain limitation. Treatment of imperceptible electric spark is used extensively in imperceptible treatment domain, already became miniature mould to machine a respect an important development way. Imperceptible electric spark machines miniature mould to have a series of advantages: Low stress. Mould of this pairs of miniature and treatment of imperceptible structural member are particularly serious, because treatment of imperceptible electric spark is to use small pulse energy to machine, the stress that machines than general electric spark so is less, more agree with miniature mould treatment. Can process tall hard data. This have special advantage, other treatment method cannot be likened to the likelihood, it has important sense to improving the life of miniature mould. Can machine mould of complex miniature antrum. Machine complex miniature antrum to depend on electrode appearance, unlike LIGA can be machined only columnar small structural member, imperceptible turning suits to machine circumgyrate only kind small part, imperceptible grinding suits to machine groove only kind small structural member. Without burr. The miniature antrum of miniature mould does not allow hairiness to prick, had burr to want to go burr is very difficult also. Treatment of imperceptible electric spark already had quite high technology level at present, system of power source of small energy pulse, small feed, servo control system, numerical control system it is in treatment of electric spark small hole receive development application. Ra can amount to the exterior surface roughness that imperceptible electric spark machines 0.

05 μ M, in the treatment of miniature antrum or miniature structural member, its machine precision to be able to achieve ≤ 1 μ M, the treatment of mould of OK and contented miniature asks. But a crucial question that imperceptible electric spark machines is miniature electrode make. So far, the filing of line electrode electric spark that Japanese Tokyo university adds Ze Longjiu to teach development (WEDG) heretofore or the effective method that make imperceptible electrode, it is to build the electrode of a kind of miniature that copies the development on treatment foundation to rise instead in electric spark to make a method. The main characteristic of WEDG: ① line electrode and workpiece (miniature electrode) for point contact, the treatment appearance of reason workpiece is concerned with figuration motion only, because this cylinder workpiece wants odd axis numerical control only, use 2 axes or 3 axes numerical control to be able to process a variety of complex form. ② because line electrode is revolving (mobile) treatment is measured very small, loss of reason line electrode is dinky, be helpful for raising treatment precision; And treatment precision basically depends on figuration motion precision. ③ discharge place is bit of area, the to workpiece vibration in discharge process or cause bent to affect minimum, suit miniature electrode (workpiece) treatment, can achieve very tall precision. Because ④ discharges it is point contact be copied instead relatively and character efficiency is inferior. It is in order to process imperceptible and columnar work exemple, m of the copper that applies WEDG method to be able to machine 70 μ M, 20 μ reachs the tungsten of 13 μ M, can have the treatment of smaller diameter even. CNC Milling