Doing cutting technology arisenly

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Dry cutting is not what should cancel cooling lubricating fluid simply to be able to come true only. Because the lubricant, refrigeration of cooling lubricating fluid and strong bits motive were lacked in cutting process, can bring about the attrition between cutting tool and workpiece to increase, aggravate of elevatory, felt mixes cutting temperature cut bits to jam, cause the cutting tool life, fall that machines precision and cutting efficiency thereby. Graph what spare parts of 1 automobile manufacturing industry machines is odd compose makes a cost overcome in the absense of cooling lubricating fluid and the difficulty that cause, need passes the data of strong cutting tool of development and applied heat-resisting, form of proper cutting tool geometry and minim are lubricant material, and agree with through using the treatment parameter with the machine tool of dry cutting and corresponding choice will solve, those who assure dry cutting process is reliable undertake. In recent years, already obtained very great progress on the development of dry cutting technology, quite a few does cutting craft already aborning popularizes application. In if Liebherr company of Germany is in,producing per year 130 CNC gear-hobbing machine, "Machine tool of simple treatment doing type " already occupied 14% , "Pure wet treatment machine tool " occupy about 22% , and compound model the machine tool occupies 64%(the time that this kind of machine tool needs to spend one day only can change his costume or dress be dry type or wet) of treatment machine tool, make clear via production, this machine tool should use high speed to fight mill gear wheel (at present, use coating hard metal, cutting speed can amount to 300m/min; Use the Cermets of coating, the sheet when cutting speed can be as high as 600m/min) charge wants mill of specific humidity type tine is low 50% . Be like again, when some factory is undertaking to tooling of car gearshift escape wheel ability changes, decision by original wet treatment is transformed to do cutting. Use hob of coating hard alloy to replace hob of original coating high-speed steel for this, cutting rate rose 290m/min by original 110m/min. This shortened not only handling time, improved the process capability of the machine tool, and every treatment charge reduced 43%(graph 2) . This shows, use dry cutting to be able to obtain very good technology economic benefits. Graph the economic benefits of escape wheel of 2 dry cars rolling mill develops according to current technology, in the machine building of industrial developed country, the application that predicts craft of dry this year cutting is expected to achieve 20% . Because material of cutting tool, cutting tool and coating do the meeting when cutting to produce intense friction and extremely high temperature (if use hard alloy bit,pledge be mixed with Vc=80m/min on steel CK45 in tone F=0.

When 2mm/min undertakes doing cutting, in the contact the area can achieve 380 ℃ - the high temperature of 410 ℃ . Be like dry mill steel again when temperature can exceed 600 ℃ ) normally, want to have taller high temperature hardness and wearability to be being used at doing the cutting tool of cutting so. Current, those who be used at doing cutting is main cubic nitrogen changes boron (material of cutting tool of CBN) , pottery and porcelain, titanium radical hard alloy (diamond of He Jujing of Cermets) , hard alloy (the cutting tool material such as PCD) . Among them CBN is the cutting tool material with hard steel of temper by dipping in water and cast-iron dry the most commonly used treatment; And nitrogen changes silicon (Si3N4) is special agree with to there is rubber circumstance to fall to undertake doing cutting to cast and nodular cast iron in interrupted cutting and cast; Cermets is the cutting tool material between cutting tool of porcelain of interpose Yu Tao and hard alloy on hardness, it is steel of high speed dry cutting right stuff. Express 1: The function of a few kinds of hard coating and soft coating develops dry cutting cutting tool, besides right choice cutting tool material is mixed outside optimizing parameter of cutting tool geometry, develop cutting tool coating to have particularly important sense energetically. Because abandon cooling lubricating fluid,can make up for through the hard, soft coating on cutting tool matrix and lost certain function. The action of coating is having a protective screen at be being built between cutting tool and cutting material, with block the way major heat in metal cutting is conducted to cutter hub. Because coating coefficient of friction is small, reduced attrition and reduce attrition heat from this. The diverse demand that good in the hard coat that already can carry a series of high temperature wear-resisting at present and lubricity soft coating will come to satisfy all sorts of dry cutting craft (express 1) . For example, because TiAlN coating has higher high temperature,hardness is mixed fight oxidation function, be in so the circumstance with cutting very high temperature, it is the most commonly used " adiabatic " coating, special apply to dry cutting the spare parts such as cast-iron, steel and stainless steel. And TiCN just falls in inferior temperature have taller hardness and better tenacity, reason very agree with use as the coating of tap, use at doing type tap. Milling and turning are a kind of extra work, heat in metal cutting eliminates to compare with what cut bits simple. And go up in sincere material bore is a kind inside treatment, eliminate from inside aperture heat in metal cutting and it is more difficult to cut bits. Accordingly, work auger cutting is the worst technology in dry treatment craft. But the development with old course and experiment, at present this difficult problem already can pass the geometry that improves bit appearance and use hard coating to solve. If improve the cross section appearance of the chamfer that discharge bits, make notch straight outspread to the petiole, helix angle that increases the chamfer that discharge bits, use bigger awl, narrower pour arris and minor the crucial point radius and use TiAlN coating and minim to lubricate wait for measure, discharge bits reliably with decreasing to chafe and ensure. In the watch 2 in listed 3 kinds work get cut successful case. Express 2: Broach works in a few kinds get the effect when cutting to should point out, dry auger cut with wet auger cut photograph comparing, the life that former advantage still depends on doing cutting bit wants prep above wet the broach of cutting. Have a case, using circumstance of identical cutting parameter to fall, the amount of the bore when dry cutting achieves 2700, and wet when treatment, cause temperature mutation because of be lubricated by refrigeration (thermal shock) influence, the treatment amount of aperture is 1080 only, the durability of dry cutting broach rose 2.

5 times. Aluminium alloy resembles in dry cutting when such plasticity material, form the tumour that accumulate bits easily on edge. Current, after the it is as good as lubricity to slide on besmear again WC/C coating on the hard alloy cutting tool in besmear diamond coating, can decrease to accumulate the formation of bits tumour apparently. Drop is lubricant and current, cut the workpiece material of bits to growing, dinkum dry cutting still cannot acquire the workpiece quality of a requirement and cutting tool life. If doing cutting aluminium when, as a result of cutting cutting tool and aluminium cut bits easy generation felt, the tumour that accumulate bits is formed on edge. Undertake when the lube that gives cutting edge eject thimbleful however " accurate " favorable result can be achieved when dry cutting. Minim is lubricant the technology is to use after compressing air and lubricating fluid to mix, its by nozzle eject goes to a kind of technology that has lubricating to cutting tool on edge. The wastage of lubricant material is normally (5-100)ml/h, use pair of environments not to have social effects of pollution mostly for example the lubricant material such as mellow ester and vegetable oil. Lube and compressing air is through finding a place for the connect of double passageway circumgyrate in main shaft back end introduces main shaft respectively, nozzle of direct before interface of hollow awl handle classics undertakes mixture (graph 3) . Lube and airy discharge can undertake process designing through NC system, in order to satisfy the cutting need of different cutting tool. The mixture device that the graph compresses air and lubricant data on component of main shaft of 3 machining center (XHC241)a.

High speed main shaft; B.

Connect of double passageway circumgyrate; C.

The outfit gas in main shaft - oily mixture nozzle; D.

Install the shut off valve in main shaft back end; E.

The machine tool controls a system; F.

Proportioning valve; G.

Systematic pressure (Max.

0.

The main effect with 6Mpa) lubricant minim is lubricant, borrow this to rise to reduce the attrition, flow that reduces heat in metal cutting and improvement to cut bits. Use minim to lubricate undertake " accurate " dry treatment, already accumulated many experience and application is being popularized stage by stage in production. It is a treatment that the factory designs BMW engine by Austrian Ernstkrause&Co company for example the transfer matic of crankcase crock aperture, because used drop lubricant technology and achieved very good treatment result. In the treatment of aperture of the crock on this transfer matic cent is thick boring, half essence boring and boring of essence of life 3 working procedure, it is important to machining the effect to have to be met considering lubricant material influence, reason is advanced two working procedure use boring tool of coating hard alloy, undertake lubricating with vegetable oil, and finish machining is used get together brilliant diamond boring cutter, the ester that use alcohol undertakes lubricating. After compressing air and lubricant material to mix before interface of hollow awl handle, the spray head in bits antrum is held in boring cutter by the setting direct gush to cutting edge, in order to make cutting tool obtains first-rate wet, have favorable lubricant effect thereby. After crock aperture finish machining, need not undertake cleaning and can go to press fitting of casting pig cylinder bushing directly in crock aperture. Of this transfer matic move make clear, with wet treatment is compared, technical economic benefits is very remarkable. Transfer matic because leave out cooling and lubricant system and rinsing equipment, make the investment of equipment decreased 22% , the accrual of apportion and facility depreciation cost are reduced 22% , and the sources of energy, personnel and equipment move waited for charge to save 11% . Current, be based on the consideration of environmental protection and economy, large quantities of car plants that estimate production are in more and more introduce dry cutting technology. If Ford car plant is in,drafted the treatment clutch housing and gearshift casing 2000 by wet treatment turns to dry cutting stage by stage. Treatment system uses the machining center of 12 XHC241 high speed of Ex-Cell-O company, machine spare parts of casing of 230 aluminium alloy thin walls with three-shift system everyday, current and compositive the standard dry treatment in the system (minim is lubricant) machine tool and wet parallel of treatment machine tool is configured, the machining center join that machines two kinds means through reprinting industrial robot rises, all machine tools will change dry type to treatment stage by stage after. Do treatment to produce medium process dependability in large quantities of quantities for test, two companies ever were opposite Ex-Cell-O and Ford clutch housing (the standard dry treatment of AlSi9Cu3) had a test, the test has on XHC241 of high speed machining center, so that can use higher cutting rate and feed rate (express 3) , experimental result makes clear, the temperature rise of the workpiece when dry treatment (4K) although the 2K tower above that specific humidity type machines one times, but temperature distributings even, clamping apparatus and machine tool temperature rise are very small. Assured ± thereby 0.

The Kong Jian of 025mm is apart from tolerancepublic errand and Cpk=1.

The process capability index of 67. Express 3: ? An official document or note of だ of commonplace of fir of flute Qi equipment lifts epiphysis to become warped be ignorant of of Yong of Mi Na Xing carries  of fir commonplace せ feed Shan Xing have a nightmare protects class of travel of Lv of Nao of Sun of   acenaphthene to say  walks be short of low-lyingponding colourful to flinch excrement of Meng of take along sth to sb of postscript Yu  disrelishs Su to hut act of purpose need さ , angle is more than 55 ° , machining an area the raised close solid bolt of bits of not due and cloggy platoon. The heat that affects a machine tool to avoid to cut the temperature of bits further is out of shape, the cover board of machine tool lathe bed still can use structure of double deck wall to have heat insulation. The high speed machining center of drive of linear to using electric machinery, still need to find a place for cooling system, in order to increase the thermal stability of the machine tool. Rinse action as a result of what cancelled cooling lubricating fluid, special machining cast-iron produce many dust and fine-cut bit with the meeting when light metal, grind the flyblow of bead to prevent these, in treatment the area is adopted except need sealed with screen establishment outside, still set pump plant, take dust and redundant minim lubricating oil with be being sucked effectively oily mist. How does dry treatment machine tool often lubricate of minim system, when this is machining aluminium alloy and magnesium, so that can prevent,accumulate bits tumour and the dependability that improve process. Graph 4 agree with the machining center of dry treatment (XHC241)a.

Of the main shaft that measures lubricant device for in-house flavour; B.

Agree with the workpiece clamping apparatus of dry treatment; C.

Agree with of dry treatment relatively apprentice discharges bits surface (> 55 degrees) and without raised arris the machine tool of edge and bolt machines an area; D. Adiabatic machine tool lathe bed; E.

Of the actuating device of linear electric machinery of cooling system; F.

Configure the device discharging bits of centrally; G.

The knife library that the level decorates. Benefit of zoology of last word pursuit and economic benefits are the main motive force that promotes development of dry cutting technology. Come nearly 10 years, because exceed material of strong cutting tool, especially the development of material of cutting tool coating, the improvement of appearance of cutting tool geometry and minim are lubricant the application of material, and the rapid development that the development that suits the equipment of corresponding form a complete set such as dry cutting machine tool promoted dry cutting technology advantageously. Dry cutting technology passes old development and test, already entered at present practical change level, working procedure of treatment of cutting of current quite a few can use dry formula completely already or lubricate through minim will solve. Rise ceaselessly as what do treatment process dependability, dry treatment is entering machining line of business stage by stage, especially more and more ground enters the big batch such as auto industry to produce a field. CNC Milling CNC Machining