Do type, half dry type and processing technique of cutting of microtherm air cooling

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  • source:AYOR CNC Machining
In cutting process, 3 are out of shape the metal of the area produces flexibility to be out of shape, plasticity is out of shape reach attrition to be out of shape, 99 of cutting power.

5% all transform be out of shape to cut slippage (the first be out of shape area) , before knife face attrition is out of shape (the 2nd be out of shape area) reach extruding, superfluous be out of shape, hind knife face attrition is out of shape (the 3rd be out of shape area) place energy consumption, it is heat energy in flashy change, appear the phenomenon that cuts area of blade of cutting of bits, cutting tool and workpiece face temperature rise.  heat in metal cutting is the phenomenon of inevitable a kind of physics in accompanying metallic cutting process, have the effect that cannot ignore to life of workpiece quality, cutting tool. When low speed cutting, mechanical wear is cutting tool tatty main reason; And when high speed cutting, cutting high temperature is revulsive of cutting tool wear away, give priority to translate into to diffuse by mechanical wear wear away, change wear away with char to basically wear away mechanism, the felt that causes cutting tool appearance wears away. Heat in metal cutting still makes cutting tool and workpiece heat expand, attrition of face of the knife after aggravate and wear away, cause workpiece surface surface roughness to rise, superfinishing craft emphasizes reason particularly must control the conduction of heat in metal cutting inside workpiece, cutting tool effectively. Temperature rise of control cutting tool, workpiece also has very important sense to CNC Machining. The intensity of the material of traceable of heat in metal cutting of  metal, hardness, tenacity, plasticity reachs flexibility, consider to still make clear, the osculatory area of the temperature rise of the cutting tool in affecting cutting process and workpiece and cutting tool, workpiece, conduct heat the element such as the coefficient, difference in temperature, accident that engages time has affinity. Normally the circumstance falls, reduce quantity of penetration of a cutting tool to be able to reduce the interface of cutting tool and heat source to accumulate; The velocity of flow that increases cooling medium, discharge conducts heat to increase namely coefficient; The temperature that drops cooling medium can increase the thermal capacity of cutting tool, workpiece and effect of difference in temperature; And raising machine tool rotate speed and cutting rate was to shorten actually the conduction of heat in metal cutting time.  this shows, want to control the temperature rise of metallic heat in metal cutting and cutting tool, workpiece, must consider many sided factor integratedly, besides the basis the character of metallic stuff, machine imposes technical quota, beyond parameter of craft of logical choice cutting tool, cutting, the most immediate step is to use all sorts of cooling medium, the cutting quantity of heat that takes away cutting tool and workpiece quickly to go up, drop temperature.  the development  of cutting of 1 dry type, half dry type (1) the major task  of industry of treatment of contemporary metal cutting has dry type in metallic cutting processing technique cutting and wet two kinds of methods of cutting. Falling under the cutting speed of 180m/min, wet cutting method can achieve ideal cutting result, already was applied extensively. In cutting process, cutting fluid basically is had drop in temperature, 3 action such as bits of lubricant, platoon.  gains ground as what numerical control changes, of cutting tool production technology rise, the cutting speed of metallic cutting machine tool efficiency of faster and faster, treatment is taller and taller, the heat in metal cutting that produces subsequently and temperature rise of point of a knife are faster and faster also, faster and faster. As a result of circumgyrate of high speed of machine tool main shaft (8000 ~ 60000r/min) can be all round cutting tool generate air stream of centrifugal high speed, high pressure, support convention increases the cutting fluid discharge, idea that drops cutting temperature rise to already cannot achieve ideal result. And the main pollution source that cutting fluid all through the ages is industry of metallic cutting treatment, these harmful liquid are discharged in great quantities, when treatment splatter, rise, so that conglutinate is cutting the open air on bits to place, long let out, discharge, final meeting pollutes environment and source of water. In addition, the cost related cutting fluid also raises in year after year, make the finished cost year after year of mechanical spare parts rises. 20 centuries at the beginning of 90 time, the experts of the developed country are opposite around process of metallic cutting treatment influence problem of the environment, undertook serious delibrate, each country government unplugs special funds is aided financially in order to replace fat dose wet the research that cutting, clean treatment does type cutting to machine craft for the purpose. In September 1996, after ISO14000 environment standard is passed in Europe, because cutting agent pollutes condemnatory strength of the environment,each country government was increased, made management of very rigorous cutting waste liquid, limitation use measure, accordingly, development is not used (or little use) the major task that the processing technique of cutting fluid makes cutting of developed country metal machine place of course of study to be faced with; Bound of science and technology tries hard creation, research can improve treatment environment, managing the sources of energy already, can raise the efficiency, dry type that reduces cost to process technique again. (2)  of method of treatment of dry type cutting is contemporary technology of dry type cutting, should study namely, search do not use (or little use) cutting fluid, can have 3 afore-mentioned effect, improve the method that cutting condition, contented treatment asks.  is current, the cutting method that cutting liquid does not use popularly on international basically has: The method of cutting of completely dry type that ① does not use cutting liquid completely (law of cutting of high speed dry type) ; The law of cutting of half dry type that ② mixes minim lubricant to replace cutting fluid with gas.  (3) the characteristic  of law of cutting of completely dry type works type cutting way completely, also call high speed law of dry type cutting. Circumgyrate of high speed of machine tool main shaft (be in normally 20000 ~ 60000r/min) , cutting tool of use high strenth, small cut deep, big take a knife, undertake cutting is machined exceeding high speed. Heat in metal cutting 90% above are cut bits is taken away, the change that adopts cutting craft requirement will come true to be machined without cutting liquefaction, its efficiency tall, cost is low, and the technology that machine tool, cutting tool throws and cost are very high. Current, home of Europe, United States is relatively popular, germany is in international banner level. According to 2001 statistic, germany already had 8% right-and-left enterprises to use this one technology, the enterprise that predicts to 2003 Germany will have 20% above uses this one technology. (4) the characteristic  that works type cutting way partly works type cutting way partly is to use gas to add drop harmless oil agent replaces cutting fluid drop in temperature, the lubricant, cutting means that discharges bits. Have commonly: MQL(minim is lubricant) cutting of cutting of cutting, azotic air current, ultralow temperature refrigeration and cutting of microtherm air cooling. Japan is more application, 1998 on exhibition of machine tool of international of the 19th Tokyo, there are 43 to have function of cutting of half dry type in 69 machine tools that Japanese ginseng exhibits.  ① MQL (minim is lubricant) cutting  method of a kind of abroad's relatively popular cutting of half dry type, replace many cutting fluid what reduce drop of the interfuse in air in normal temperature without oily mist of social effects of pollution, executive refrigeration, lubricant to cutting dot with platoon bits.  of cutting of air current of  ② nitrogen is special nitrogen happening device mixes the oxygen in air, carbon dioxide water eduction, extract nitrogen, enter gas blowout of these normal temperature nitrogen cutting area, in order to alleviate the combustion process of metallic stuff, achieve the goal that reduces temperature rise.  of cutting of refrigeration of  ③ ultralow temperature falls in constant pressure action, will - the liquid nitrogen of 180 ℃ or - the CO2 liquid of 76 ℃ sends cutting the drop, replace the cutting method of a large number of fat doses. But difficulty of this method technology big, cost is high.  of cutting of air cooling of  ④ low temperature will compress airy temperature to reduce 20 ℃ ~ 30 ℃ , mix in a subtle way to measure lubricant, executive refrigeration, lubricant to cutting dot with platoon bits, the point with this kind of method and MQL different cutting is ultralow temperature wind cold, make cutting dot low temperature is changed. 2 low temperature of   of law of air cooling cutting (1) the influence  to cutting tool life is in cutting of microtherm air cooling in cutting process, the temperature rise that cutting of point of a knife nods is very big to the influence of cutting tool life, the treatment place eject that law of cutting of microtherm air cooling is Xiang Dao needle ~ of 0 20 ℃ the microtherm air stream with 30 smaller even ℃ , the plant sex lubricant that mixes quantity of in a subtle way (horary 10 ~ 20ml) , air current of generation low temperature drops in temperature, minim oily mist is lubricant cutting and the action that discharge bits. Cutting nods microtherm to change, make workpiece material local and cold-short not only, the cutting that is helpful for cutting bits ruptures and drop cutting negative charge, also prevented cutting tool oneself at the same time diffuse wear away, change wear away with felt, downhill race of embellish of minim oily mist became low cutting tool and workpiece, cutting tool and cut the attrition force between bits, make cutting tool life gets extension. It is difficult that law of cutting of microtherm air cooling suits aluminium alloy of titanium, magnesian, molybdenum, tall silicon, stainless steel to wait especially cutting material and the treatment that Bao Bicai expects. (2) cutting of microtherm air cooling is to machining the influence  of quality in process of metallic cutting treatment, the stable impact that the discretion of workpiece temperature machines dimension to the surface is very big. The experiment proves, when cutting of microtherm air cooling, the temperature rise of workpiece and cutting tool is small, be out of shape small, obstruction of cutting of face of cutting tool back end is reduced. And, the temperature that nods as a result of cutting is relatively smooth, stress of treatment surface remains is little, workpiece surface quality assures easily. In the test that in Chengdu factory of peaceful river machine tool has recently, with aluminium alloy of superfinishing of diamond cutting tool, technology of cutting of air cooling of use low temperature, workpiece surface surface roughness is as high as Ra0.

05 μ M, and fat dose turning is used below identical cutting condition, exterior surface roughness is Ra0 only.

15 μ M, show the superior performance of technology of cutting of eject of microtherm air cooling.  (3) cutting of the advantage  dry type of cutting of microtherm air cooling, half dry type is called the cutting technology of new century, and technology of cutting of microtherm air cooling is a most national condition, practical kind to suit our country most, it is like next advantages:  ① machines efficiency but twice rises (turning of microtherm air cooling can improve efficiency 1 times, grinding of microtherm air cooling can improve efficiency 3 ~ 4 times, the Leng Zuan inside microtherm air cooling cuts means to be able to improve efficiency 20 times or so) ;  ② almost free from contamination, improvement produces a condition; Agent of  ③ managing cutting purchases cost, reduce manufacturing cost; ④ cuts bits to be able to reclaim directly, increase economic benefits;  ⑤ is helpful for be being machined automatically, detect and monitoring; Measure of  ⑥ work gets treatment temperature impact is very little, quality is stable; Twice of life of  ⑦ cutting tool is lengthened, reduce cutting tool cost, shorten the machine tool plans time; The treatment that  ⑧ is helpful for chromic alloy of titanium, magnesian, nickel waiting for difficult cutting material;  ⑨ is helpful for the attestation of enterprise IS014000 and IS016000 standard. Technology of cutting of microtherm air cooling can make the cutting efficiency of cutting tool taller, cutting performance is better, applied perspective is wide. In making the enterprise is machined in cleanness, obtain environmental protection to obtain enormous economic benefits again already. Current, technology of cutting of microtherm air cooling already had application in our country, its apply limits to still will expand ceaselessly. CNC Milling