Turning treatment exceeds hard data

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As the ceaseless development of manufacturing industry, the home is seeking manufactory of world machine tool to reduce the manufacturing cost that processes spare parts and finished product with new technology all the time, make exceed hard cutting to become current the new-style treatment craft that each manufacturer pays close attention to. Anticipate in before long in the future, exceed hard cutting technology to will develop more maturely, be used extensively by people. Exceed hard turning technology to exceed hard turning to be defined to be high to HRC 45 above hard talent to pledge work sheet chooses the treatment course of cutting. Normally workpiece material qualitative hardness can achieve HRC 58 ~ the limits of 68, material of cutting cutting tool basically chooses CBN character (cubic nitrogen changes boron) . The treatment that exceeds hard turning technology not to beg freeboard nicety grinding for those is made offerred a new alternative. Of course, the workpiece of the workpiece of accurate to certain freeboard requirement, easy metabolic workpiece and special requirement, grinding craft still compares the choice that suit. Although exceed hard turning to still cannot replace freeboard nicety grinding completely at present, but already can replace quite the accurate grinding of one part, reduced grinding to make the high manufacturing cost in the process thereby. Current, the workpiece surface surface roughness that exceeds hard cutting can amount to Ra0 commonly.

2 ~ Ra0.

4, circularity can be amounted to 0.

0005mm, dimension precision is controallable in 0.

003mm less than. Compare discovery through cutting, the manufacturing efficiency that exceeds hard turning to machine craft to machine craft than general grinding wants tall 4 ~ 6 times. From the graph 1 can see clearly, the cutting below the case that using cutting fluid refrigeration the hard part of a HRC 62, can produce a lot of quantity of heat. When exceeding hard cutting commonly, cutting nods the temperature inside area to be able to be as high as 926 ℃ . In fact, local tall lukewarm thermalization can help the finishing of cutting process, the high fever that cutting tool cutting nods produces anneal and bate effect to the cut of workpiece beforehand, make workpiece easier cutting. The course is cut in all these in, the heat of the majority is by what cut bits to come off and arise. Machine quality to get elegant face, when last cutting, answer to reduce cutting deepness as far as possible, ordinary control is in 0.

25 Mm less than. In exceeding hard turning to already was made in car component by wide application currently. Total plant of Shanghai car gear uses this one technology successfully produce at large quantities of quantities in the center, they will 3, 4, after 5 archives combine gear cementite to quench, with the car era is ground, undertake the final nicety of finished product is machined, in order to achieve the public errand that the spare parts designs and requirement of exterior surface roughness. Can be amounted to by the exterior surface roughness of treatment workpiece Ra0.

2 ~ Ra0.

4, circularity can be amounted to 0.

0005 Mm, 0.

The public errand of 003 Mm is taken, cpk value can be amounted to 1.

67. It is important that the stability of successive treatment is opposite a when exceed hard data to undertake turning the stability that indicate even if assures successive treatment. The heat treatment condition of cutting tool of this as dynamic as the whole of the machine tool tigidity, cutting, workpiece is concerned. Use polymer (scagliola) to lathe bed each are main place undertakes filling up, increase its damp coefficient (be cast-iron lathe bed commonly 8 times) , at the same time union uses linear scroll guide, will be opposite the impact that exceeds good material to expect turning process generation is huge, reduce the vibration that causes because of cutting greatly, the time that increases tigidity of fast regression static state (see a picture 2, graph 3) . The test makes clear as a result, the improvement of the machine tool restrained the blade of cutting tool collapse that brings by machine tool vibration effectively, prolonged the service life of cutting tool, rose to be machined substantially the precision of workpiece, narrowed the disperse of tolerancepublic errand belt is spent, improved workpiece surface quality. Nextpage another main influencing factor is a machine tool the function of each mobile axis conformity and precision, precision of the accuracy that includes a machine tool, geometry, electronic-controlled compensation of function, error and be adjusted commonly and heat is out of shape effect. Because the last treatment achievement of workpiece is decided completely by the function of the machine tool and precision,this is. Choose knife of pottery and porcelain when thick car normally, cutting deepness is more than 0.

25mm; CBN knife is chosen when fine vehicle, cutting deepness is less than 0.

25mm. Want to make the turning that exceeds hard data obtains ideal result, still need to control the heat treatment state of the workpiece that be added, quench hardness change asks to be less than HRC commonly two between the dot. If workpiece is cementite, assure the consistency of cementite layer deepness even, should be in deepness control commonly 0.

8 ~ 1.

2mm less than. Exceed the advantage of hard data turning and grinding craft photograph to compare, the turning that exceeds hard data has the following advantage: 1, can undertake already on a lathe " soft cutting " , can undertake exceeding hard cutting again, a machine tool is equivalent to two machine tools using, saved workshop space already, reduced the capital investment that buys a machine tool again; 2, the 4 ~ that the cutting efficiency that exceeds hard turning is grinding 6 times; 3, in exceeding hard turning process, the characteristic that can use lathe tool sheet to nod cutting processes the work of complex form, and grinder can undertake grinding with figuration emery wheel only; 4, set is achievable multinomial cutting working procedure, saved the carry and weighs new clothes buy time of workpiece, reduce work loss; 5, exceed hard turning to be able to achieve Ra0 easily.

2 ~ Ra0.

The exterior surface roughness of 4; 6, the workpiece that exceeds the lathe of hard turning to be able to get used to different specifications. Be in especially mould industry, can satisfy the treatment of different batch and intricate work; 7, exceed hard turning cut bits relatively manageability of the look that worry bit, accord with environmental protection requirement; 8, cost of cutting tool stock is inferior. Conclusion exceeds hard turning is a practical technology, can offer good economic benefits and relatively the workpiece character of beautiful, the economic benefits that arises on the machine tool of tall dynamic tigidity especially is more obvious. Exceed hard turning process and general turning process to do not have too big distinction, the majority produces manufacturer to be able to introduce this one new technology, apply at actual production in the center. Look into future, improve of craft and machine tool function ceaselessly as cutting, exceed hard turning this new technology will tend stage by stage perfect, be sure to receive more wide application. CNC Milling CNC Machining