The small treatment of 5D simple feature to spare parts of complex 3D curved surface, the tiny pattern that through using this method treatment gives can achieve the goal that batch produces. Basically introduce mechanism of small cutting equipment, cutting tool, cutting below. 4.
The dimension of spare parts of equipment of 1 small cutting and treatment quality (surface roughness of treatment precision, surface, repeat precision) the function that machines a machine tool with its (if precision, trends is characteristic,wait) closely related. The function of the machine tool basically is mixed with main shaft, workbench control system is concerned, the diameter that small cutting place uses cutting tool is very small, machine efficiency to rise, the rotate speed of main shaft of small cutting machine tool is very fast. To satisfy torque requirement, use electric main shaft and bearing of mixture horn contact normally, this kind of bearing causes heat to expand as a result of attrition heat build-up, top rotate speed does not exceed 60 thousand R/min commonly. Become when rotate speed is higher, should use air bearing, but the torque that air bearing offers is lesser, at present the top rotate speed of air bearing main shaft can amount to 200 thousand R/min. To achieve higher cutting rate, the taper of the taper of main shaft and knife handle of high speed cutting is consistent. The workbench of machine tool of small cutting nicety is commonly by drive of linear electric machinery, compare like photograph of ball guide screw with common drive, system of drive of linear electric machinery does not have what attrition and electromagnetism coupling arise to accumulate an error, the precision loss that because wear away,also did not cause, nonexistent clearance, and can offer bigger acceleration, the precision of system of drive of linear electric machinery can amount to ± 1 μ M. The stiffness of machine tool of small cutting nicety is good, vibration is little, and contain mostly all sorts of sensor and carry out implement. But because its size is larger, stricter to the control requirement of surroundings, make the cost that machines small part higher. Because the treatment feature size of tiny and mechanical product is very small, researcher is trying to develop tiny machine tool to machine small part. The bulk size of tiny machine tool is very small, but managing and much raw material, accordingly, the data with can better workability will make. Additional, because quality is small, the natural frequency of tiny machine tool is taller than general accuracy machine tool, this makes OK and stable ground is in tiny machine tool to be used inside range of wider main shaft rotate speed and do not produce flutter. Although produce vibration, the amplitude of tiny below same load machine tool is small also. The fixed position precision of tiny machine tool can attain accept rice scale, treatment precision is inferior micron. The development of tiny machine tool introduced a new idea namely " miniature chemical plant " . Miniature chemical plant covers an area of an area very small, can place within any buildings anyplace, go up in battlefield even or apply inside dimensional station, and to general accuracy machine tool, this is impossible almost. The sources of energy that miniature chemical plant wastes is very little, big earth is managing of the sources of energy use. There is different manufacturing unit inside miniature chemical plant, wait for equipment like milling machine of miniature lathe, miniature. The development of tiny machine tool is facing a series of challenges at present, if need to develop measure enough small sensor and carry out implement, so that can install Yu Wei inside small machine tool. The tigidity of tiny machine tool is inferior to machine tool of small cutting nicety, additional, to prevent outside interference, tiny machine tool needs to add vibration isolation device to satisfy treatment precision requirement. The finished cost that reduces miniature chemical plant and development are muti_function the development trend that compound and tiny machine tool is equipment of prospective small cutting. 4.
Cutting tool of 2 small cutting is in domain of small cutting processing technique, how refine grain of cutting tool material and cutting tool is tiny change, so that treatment gives miniature work, it is the key place of research all the time. The cutting deepness of small cutting and feed are very small, the cutting power on unit cutting area is accordingly greater, produce very big quantity of heat at the same time, make edge most advanced and local the temperature of area is elevatory, because this is in,small cutting asks to the function of cutting tool material taller, need to use hardness of wear-resisting, heat-resisting, high temperature the cutting tool stuff with good strength of tall, high temperature, as circumgyrate of the smallest diameter tiny change, the bending strength of requirement circumgyrate cutting tool, tigidity and rupture tenacity all answer taller. Material of small cutting cutting tool with hard alloy (carbonization tungsten) , PCBN (stereo nitrogen changes boron) give priority to with diamond. The nonferrous metal such as the aluminium alloy of the following dimension machines micron class to basically use cutting tool of single crystal diamond, cutting tool of single crystal diamond can use cutting to machine precision to achieve the probe of accept rice class or bougie. To improve the performance of hard alloy, at present tool manufacturer is considering to make hard alloy grain more imperceptible change, and already obtained delectable positive result, already developed a diameter to be 90nm exceed fine grain hard alloy and what trial-produce gives a diameter to be 60nm is advanced exceed fine grain hard alloy. Express the diameter of function WC bead that 1 exceed fine grain hard alloy (Nm) - hardness (HV) - stretch model is measured (GPa) 300 - 1902 - 570 90 - 2361 - 600 besides cutting tool material, the geometrical figure of cutting tool is crucial to treatment of implementation small cutting. Below small cutting condition, excise paper-thin material accurately to need extremely sharp cutting blade, namely dinky point radius. Not only such, point is sharp degree still matter to cutting surface quality, microcosmic organization appearance and crystal lattice the fault. Measuring outline of cutting tool point accurately is to make sure cutting tool point is abrade with the premise that undertakes quality of imperceptible cutting process is analysed. Qualitative hardness of small bit or material of the small knife that carry mill tall, treatment is difficult, efficiency of commonly used treatment of method of emery wheel grinding is low, and with FIB (Focused Ion Beam, focusing is ionic bundle) , WEDGE (Wire Electro Discharge Grinding, grinding of line electrode electric spark) the method makes hard alloy small bit or small establish milling cutter very convenient, satisfy precision requirement easily. The figure such as two tine, echelon, semicircle, one glyph, square can use when milling establish milling cutter. The hard alloy that suits imperceptible cutting takes handle milling cutter to already was used extensively on industry, the technical demand of milling cutter of the high accuracy miniature that make and broach is very high, the diameter is smaller, it is more difficult to make, the smallest diameter is 0.
The bit that the milling cutter of 1mm mixes already can be produced. In the bit of hard alloy miniature that reachs it is thus clear that on the market at present, through abrade twist drill the smallest diameter is 0.
03mm, flat get for 0.
01mm. According to the report, use in the lab electroanalysis grinding means, can make 0.
The dinky diameter broach of 005mm. The miniature cutting tool that at present the market provides, the deviation of its dimension and appearance is extremely inhomogenous. For example, 31 diameters that offer to same supplier are 0.
The broach of 02mm has a test, test result: Diametical average is 0.
021mm, standard deviation is 0.
0015mm; Core thick average is 0.
0063mm, standard deviation is 0.
0017mm, such precision is apparent poorer. Accordingly, the production precision that raises miniature cutting tool is one of issues that small cutting needs to solve. The research of mechanism of small cutting of mechanism of 5 small cutting to logical choice cutting parameter, make sure small cutting machines quality, reduce the import with raise productivity to having very manufacturing cost, important. When small cutting, because workpiece size is small, come from intensity, stiffness say do not allow to use bigger cutting deepness and feed, it is the requirement that assures work measure precision at the same time, the surface of final precision work excises a ply to must be less than its precision value, because of this cutting dosage must very small, if cutting deepness is less than the grain diameter of material sometimes, make cutting can undertake inside grain only, at this moment cutting is equivalent to discontinuous to each body undertaking cutting, the physical essence of cutting is to sever the tie between material element, atom, realize the purify of atom or element, consequently traditional with successive medium mechanical the cutting theory that is a foundation is unwell already Yu Wei cutting, so, the research of small cutting mechanism needs to use the method that differs with traditional plasticity theory to undertake study. The promotion that theory of plasticity of gradient of meet an emergency is traditional plasticity theory and perfect, it is join classical plasticity is mechanical the necessary bridge between theory and atomic imitate. Already developed in recent years rise plasticity of a variety of gradient of meet an emergency are academic, relatively typical have CS (Couple Stress) theory of plasticity of gradient of meet an emergency, SG (Stretch And Rotation Gradients) theory of plasticity of gradient of meet an emergency and MSG (Mechanism - Based Strain Gradient) plasticity of gradient of meet an emergency is academic. Use theory of gradient of meet an emergency, can dope scale effect is mixed a bad influence, achieve the result with experiment photograph be identical, micron impress, crackle was analysed successfully already in small machine and domain of small component part crackle of most advanced field, interface, filament is turned round wait for a problem with scanty Liang Wanqu, begin to be in small shape get applied in research, using theory of plasticity of gradient of meet an emergency to study small cutting is out of shape will be the way that small cutting mechanism studies. Additional, the main shaft rotate speed when small cutting is general very tall, treatment precision requirement is point-device, accordingly small cutting has the feature that high speed essence cuts closely, high speed nicety the research achievement of cutting mechanism uses small cutting field also is the trend that small cutting studies. (1) the imitate copy Allah of small cutting mechanism should be used finite technology and yuan of element are kinetic method, finite yuan of technology with successive medium mechanical for the foundation, because this element is kinetic method more apply to small cutting. Introduce an element kinetic method emulates research to the imitate of small cutting mechanism ten years already are begun inside alive bound limits, studying the work basically is the cutting model that builds measure of atomic, element, go understanding from angle of atomic, element cut bits and surface to fashion a process, parameter of geometry of explanatory material function, cutting tool and craft parameter distributing to small cutting stress and meet an emergency, temperature of cutting force, cutting and the influence that already machined exterior quality to wait. (2) the ply of the smallest effective cutting that ply of the smallest cutting can stabilize cutting calls ply of the smallest cutting. The quality of surface of the logical choice of dosage of the minim processability of material of stability of force of the configuration cutting bits in small cutting, cutting, cutting, workpiece, cutting, treatment effect that suffers ply of the smallest cutting, because this is the smallest the research of cutting ply is great to small cutting meaning. The physics of material of the circular arc radius of the ply of the smallest cutting that small cutting can achieve and cutting tool point, workpiece is mechanical function, microcosmic constituent structure pass an imperial examination 3 be out of shape area cutting tool, the coefficient of friction between workpiece about. Because the influencing factor of ply of the smallest cutting is more, decide ply of the smallest cutting harder, producing actual in the bulk of radius of circular arc of cutting tool point comes common ground ply of affirmatory the smallest cutting. Consider to make clear: Ply of the smallest cutting and radius of circular arc of cutting tool point concern into direct ratio, coefficient of proportionality and cutting tool and workpiece material deputy about, it is commonly 0.
165 ～ 0.
246, if radius of cutting tool point is 50nm, want to realize the ultrathin small cutting of cutting ply minimum, ply of right now the smallest cutting is 10nm about. (3) generation of the ability when cutting bits configuration to be more than ply of the smallest cutting when the cutting deepness of small cutting only cuts bits. With common cutting likeness, of small cutting cut bits to have 3 kinds of pattern: Consecutive record cuts bits, blame consecutive record is cut bits cuts bits with what accompany the tumour that accumulate bits. Speed of the function of the pattern that cuts bits and workpiece material, cutting, cutting is out of shape etc about. (4) the cutting force when small cutting of small cutting force is lesser, but unit cutting power is greater, and cut fight force greatly to be more than advocate cutting force. Cutting force follows cutting to reduce and increase of deepness, and cutting deep very hour cutting force can increase quickly, this is the dimension effect of cutting force. The existence of effect of cutting force dimension makes the cutting force model of common cutting unwell already add up to Yu Wei cutting. The dimension effect of cutting force and relationship of radius of cutting tool point are close, as a result of the existence of radius of point circular arc, cutting blade forms a larger part before losing when minim cutting, make cutting is out of shape increase, the unit cutting force when cutting increases. If cutting deepness decreases Xiaoshi further, cutting undertakes in grain interior likely, right now, cutting force must be more than the element of crystal interior, atomic adhesion, make the cutting force on unit cutting area increases quickly consequently. Force returns the cutting when small cutting to be concerned to He Jing bound with brilliant. (5) because cutting temperature is small the cutting dosage of cutting is lesser, because this and traditional cutting photograph are compared, the cutting temperature of small cutting is inferior. For taller to precision requirement small treatment, the change that machines temperature is to machining the influence of precision cannot of oversight, at the same time cutting temperature also cannot be ignored to influence of tatty of small cutting cutting tool. (6) the purify process of the material of minim processability workpiece of workpiece material depends on not only cutting cutting tool, at the same time also itself of material of workpiece of be enslaved to be enslaved to. Surface roughness of appearance of stage of usable accept rice reachs the minim processability of material of small cutting workpiece to be opposite on some treatment distance cutting tool tatty but oversight sex will define. The factor that affects processability of workpiece material minim includes by workpiece material and cutting tool material add up to a gender in person (chemical reaction) , the crystal structure of workpiece material itself, wrong, blemish distributings and heat treatment condition (the anisotropy that is like polycrystal material is opposite integrality of surface of spare parts treatment is had bigger. (7) cutting tool is out of shape the tigidity of cutting tool machines a process to have to small cutting quite the influence of degree, when if be become in milling treatment,cutting tool tigidity is not worth, the meeting in machining a process makes machine precision to become poor, serious when can make small establish milling cutter to rupture. Small the cutting tool that establishs milling cutter be out of shape the δ in type of I of · of E of · of L3/3 of · of the =F that it is δ the radial deflection that establishs milling cutter; F is radial cutting force; L extends length for cutting tool; E is the stretch model quantity of cutting tool material; I (I= π D4/64, d is the equivalent diameter that establishs milling cutter) the extremely inertial quadrature that is cutting tool. (8) exterior surface roughness and appearance of form of surface of cutting stability workpiece are the result that goes up to workpiece as a result of the outline map of cutting tool, because this machines exterior surface roughness,reach appearance of cutting tool point to decide by the precision that moves relatively between cutting tool and workpiece. When small cutting, if cutting deepness is less than the grain diameter of workpiece material, be equivalent to discontinuous to each body undertaking cutting, the inhomogenous sex that the microcosmic blemish of workpiece material and material distributing character make the cutting tool cutting force change when small cutting bigger, make cutting blade gets bigger impact and vibration. The vibration in imperceptible cutting is right the influence that machines exterior quality nots allow oversight. (9) burr burr is the tiny prominence that after cutting is machined, is out of shape as a result of plasticity in workpiece surface place arises. The existence of burr meets those who affect a part to cooperate, reduce the dimension precision of workpiece and exterior quality. Use the part that takes burr to be able to bring safe hidden trouble, be in especially certain and special situation, wait for a domain like aerospace. Accordingly, must increase go burr working procedure, go the method of burr has rigid standard, heat energy law, chemical law, electrolysis, electrochemistry law, abrade law to wait. (10) bits tumour is accumulated to not allow to ignore in the influence in treatment when small cutting of the tumour that accumulate bits, cold welding can cause angle of cutting tool geometry to produce change in the tumour accumulating bits on edge, influence cutting force and cutting are out of shape, the tumour that accumulate bits still can affect treatment surface surface roughness. The generation of the tumour that accumulate bits suffers the effect of speed of the microcosmic blemish of edge, cutting and feed. When small cutting, the smaller tumor that accumulate bits exceeds cutting rate tall, the smaller tumor that accumulate bits also jumps over feed tall. (11) cutting tool wears away as similar as common cutting, the invalidation of small cutting cutting tool also has two kinds of forms: Wear away and collapse blade damaged. 3 are out of shape of the area be out of shape, especially the 3rd be out of shape the cutting tool of the area, the attrition between workpiece and because be machined,stretch extensive resume a session of the surface causes cutting tool mechanical wear. When beginning cutting, cutting tool existence is initiative small wear away, in cutting after period of time, cutting tool wears away meeting gradually aggravate, can worsen suddenly even sometimes. Cutting tool wears away to basically happen in cutting tool before, hind on knife face. Because oxidize, diffuse wait for action, cutting tool also can produce thermochemistry to wear away. Collapse blade damaged is the stress that goes up when cutting tool point those who exceed cutting tool material is local bear happen when force, it is the most difficult forecast and pilot injury, and before be being compared to machining the influence of exterior quality, hind influence of knife face tatty wants big. Reduce cutting temperature to be able to reduce cutting tool effectively to wear away. Cimatron E of technology of CAD/CAM of 6 small cutting is to apply to the business of small cutting to use CAD/CAM software, basically use at small milling. From April 2003 the portion begins, european banking community begins to aid financially CRAFT, 24 inject moulds of month of plastic to miniature package had last a period of time small milling research. This project involves the whole process of miniature processing technique, the orgnaization that joins this project includes Fraunhofer Institute Of Production Technology (IPT) , Magafor of manufacturer of Kern of business of machine tool of Cimatron Gmbh of CAD/CAM software vendor, milling, tool and die manufacturer Promolding B V Structoform and MMT AG) . The hardness of mould material is 53HRC, the M of precision <5 μ of miniature mould milling, ra<0 of curved surface surface roughness.
2 μ M. The cutting tool diameter that tool manufacturer offers is the smallest amount to 50 μ M, highest turn up goes to the main shaft of small cutting machine tool that business of milling machine tool offers 160000rpm, CAD/CAM software vendor provides the Cimatron E software that applies to small cutting. Build a model to differ with simple substance, the hypostatic curved surface of Cimatron E mixes the technology that build a model to use " to make design " CAD function comes repair geometry model, through confluence of all sorts of curved surface function aperture becomes entity, technology of its ACIS kernel offers the in-house precision that is as high as 1nm, in order to satisfy the special requirement of small milling. To reduce a risk, prevent to change the discontinuous miniature curved surface of the generation in knife process, cimatron E can offer a variety of small milling to machine strategy. NC supports diagonal in strategy or the knife below helix assures cutting tool utmost to be mixed glossily enter work continuously. Cutting of applied high speed is passed in machining a process (HSC) strategy gains the cutter track that agrees equably, use knowledge of semifinished product remain to prevent a knife, leave with undertaking to miniature antrum thick. The small milling technology of Cimatron E remains truely through identifying miniature semifinished product and those who have same function thick, open thick, precision work 2 times small leave with cycloid thick wait for treatment strategy to make sure cutter track contrail is efficient and safe. Tall hardness material and the short awl that treatment quality asks tall curved surface needs very small diameter when cutting of 5 axes linkage cutting tool undertakes. To satisfy high speed the requirement of imperceptible milling, cimatron E used a variety of high speed milling to machine strategy, if horny ministry is round,finish machining of cycloid of horny join, 0 jackknife, S mixes even the knife the knife below helix, get used to Z layer finish machining and streamline treatment oneself. Cimatron E also supports batten to approach treatment and streamline milling, reduce handling time, reduce cutting tool to wear away with damaged. The development of processing technique of 7 small cutting looks into miniature machinery is an important development way, applied foreground is very good, pay close attention to the research of this one domain domestic and internationally very much, small cutting processing technique is one of research direction with production the most active domain of micro computer instrument. At present craft of small small-sized machining and equipment consider to exploration phase still is in on whole, the technical system that has not form complete maturity and dimensions restrict modular technical ability. Predict to was not controlled, tiny workmanship and relevant equipment technology will get developing quickly, be in especially small small-sized weapon, small small-sized and medical the respect such as appliance, copy unripe appliance, exploration appliance, aerospace appliance will get applied extensively. In small cutting the respect will take the research of the following task seriously henceforth, in order to promote the manufacturing application of small cutting technology. (1) the research that small cutting uses basic research to include cutting of miniature spare parts to process equipment key technique, basically study system of high speed main shaft, the fixed position of accurate workbench, motion reachs control technology, compound small cutting processes equipment and technique; Material of small cutting cutting tool and cutting tool make technical research; The monitoring technology of the fast outfit clip of small cutting cutting tool, workpiece, test and process of small cutting treatment. (2) the research of small cutting mechanism basically considers to heat up, the small cutting below action of force coupling stress is inhomogenous be out of shape, this compose equation that studies data of the workpiece below small measure, analytic small cutting is out of shape the dimension effect of the area, inhomogenous meet an emergency, the fault be out of shape to cutting stress is mixed cut wind shear contrast can influence; Study ply of the smallest cutting is right the configuration that cut bits, already machined the surface to form, temperature of cutting force, cutting microcosmic organization structure adjusts the influence that wait and workpiece data exterior surface roughness and the influence that second surface injures, build small cutting to process theory and technical system; Imperceptible cutting imitate emulates research much measure technology, lay the applied foundation of small cutting processing technique. (3) small cutting craft considers to if alloy of steely, titanium, stainless steel, aluminium alloy, pottery and porcelain and other are metalloid,include all sorts of new material material and the small cutting of all sorts of composite material machine craft, technology of small cutting CAD/CAM. (4) the economy of small cutting processing technique and dependability research. CNC Milling