The NC process designing that mould high speed machines is politic

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Summary: The article sets out from the angle that optimizes high speed to machine process, the NC process designing that elaborated treatment of mould high speed in detail is politic, the choice, high speed that uses high speed high accuracy machines the basic principle that incorporates high speed to machine cutting tool contrail to generate and method, cutting dosage that gets used to high speed treatment the respect such as the strategy of high speed treatment of crucial control technology, model face and difficult treatment face; Be aimed at effective treatment process, put forward to make the issue that the attention needs when high speed machines process designing strategy. Processing technique of 1 foreword high speed is to use high rotate speed, fast feed, small cut the way of a kind of treatment that raise cutting to machine efficiency greatly with small step pitch. It already was made in aerospace, auto industry and mould are made, light industrial the product is made waited for creation of essential industry domain to give breathtaking benefit. The successful implementation that high speed machines depends on a lot of elements, include system of high speed main shaft, CNC, special cutting tool, and special treatment technology and treatment control method. In process of high speed treatment, the blame of cutting tool is normal damaged is the serious difficult problem that treatment of current high speed faces. Mental allowance is extremely inhomogenous easy cause cutting tool damaged and cut too, it is very important to because this maintains constant material purify,be led. However, in be being machined to taking the complex 3D of face of know how things stand and feel confident of handling them, cliff face, groove and cant side, satisfy this one requirement very hard. Wait to bring about cutting tool very easily to be cut too because of the abrupt change of acerb corner or cutting tool direction, damaged damages even main shaft. In addition, in the treatment of high rotate speed and tall feed speed the condition falls, cutting tool damages extremely easily; A lot of cutting tool that at the same time place of machine tool of high speed treatment uses, undertook handling in periphery or central part, so that high-pressured cooling fluid or compress gas to will cut bits to be blown from workpiece. These processing are in go up somehow the intensity that weakened cutting tool, ought to avoid as far as possible. Go on wheels to make sure high speed is machined, improve the treatment quality of the spare parts, prolong cutting tool life, shorten handling time, high speed treatment has the special technology that is different from common CNC machining to ask, if maintain feed of constant cutting load, every tine to should keep constant as far as possible, the feed that keeps stable moves, make feed speed loss reduces the smallest, abrupt change that avoids knife direction and acceleration, program to handle speed maximize. These ask to sufficient attention deserveds when formulating strategy of process designing of high speed NC. Pay attention to the research that machines to high speed domestic and internationally all the time, treatment of the cutting cutting tool below condition of high speed treatment, high speed is emulated, monitoring of the precision safeguard that machines a process, cutting tool, had undertaken from the respect such as adaptive control much research works. Already different level provided a lot of application software high speed machines special module. But the Nc process designing that machines to how optimizing high speed is politic, the cutting tool such as the blade of cutting tool collapse in machining a process in order to eliminate is not normal damaged, sufficient play high speed machines the problem such as the function of efficient high accuracy of the machine tool, still need to undertake study deep and be discussinged. The article basically changes process from actor, the point of view that removes cutting tool to be not normal damaged sets out, elaborated what metallic mould high speed machines NC process designing to optimize strategy in detail: (The option that 1) takes cutter track way and optimize; (Dosage of cutting of 2) logical choice; (3) uses the key of high speed high accuracy to control a technology; (The treatment of 4) model face and difficult treatment face is politic. The choice that 2 high speed machine cutter track diameter and the cutting load that optimize an efficient cutting tool way to be able to be stabilized through maintaining will protect cutting tool, carry high feed rate through avoiding to machine directional mutation, it will decide directly complex model the possibility that face high speed machines, quality and efficiency. 2.

The basic principle that contrail of cutting tool of treatment of 1 high speed generates and method use CAM system to undertake high speed machines the cutting tool way that place of NC process designing makes, want to satisfy the high accuracy requirement of dimension and outline not only, consider to machine the treatment detail of craft even at the same time, choose proper treatment strategy and craft parameter to optimize all sorts of cutting tool method, in order to improve cutting condition, reduce handling time, reduce cutting tool to wear away, avoid edge damaged or knife handle to break off etc. The cutting tool contrail that high speed machines must satisfy experience of have nothing to do with, without collision, contrail load of smooth, cutting is flowing, contented the condition such as treatment requirement; In the meantime, make sure the treatment precision of the spare parts and exterior surface roughness ask; Shorten cutter track line, reduce time of knife of advance and retreat and other to assist time; Convenient numerical value is calculated, reduce process designing workload; Reduce block number as far as possible. Appearance of spare parts outline is versed in to adding quality of efficiency, treatment, process designing is calculated complexity and part program length having main effect. How basis face figure, cutting tool appearance and requirement of spare parts treatment, logical choice takes cutter track way is very complex but very serious problem. Complex model face treatment can use a variety of method taking a knife, be like parameter line model, sectional line, radiation, annulus etc. The program of cutting tool contrail that parameter line takes a knife and knife calculation is simple, agree with parameter line distributings evener circumstance. Sectional law distributings to curved surface reseau not quite even and the constitutes curved surface treatment that forms by many curved surface is very effective. Annulus cuts a law to basically apply at border to get limitative part (be like model antrum kind spare parts) treatment. When using annulus to cut a law to machine the spare parts of the type such as airscrew paddle, because workpiece stiffness is small, treatment is out of shape the problem is highlighted, because this is used from in when the annulus outside arriving cuts a knife, of position of cutting tool cutting all around can get the support of frame of semifinished product tigidity, be helpful for reducing workpiece to be out of shape mediumly in treatment process. 2.

2 actor choose knife means to enter, when the high speed that retreat a knife is machined, cutting tool cuts the way of workpiece, affect treatment quality not only, also matter to the safety of treatment directly at the same time. When workpiece of cutting of cutting tool high speed, workpiece will produce certain active force to cutting tool. In addition, cutting tool cuts workpiece greatly to will shorten with full feed speed with be being cut completely cutting tool life. Through increasing cutting load more gentlily, carry successive cutting load, can achieve the goal that protects cutting tool. When means of knife of affirmatory cutting tool, advance and retreat, tangential or what edge rough sketch should use as far as possible when the attention is cutting work is inclined to the way that cuts slow cut work (for instance: Straight formula is cut cut) with screw type, arrange in order to maintain light of cutting tool contrail flowing. Diagonal and screw type cut the rough machining that applies to brief monotype antrum into means. Treatment surface quality and precision demand are high complex model when the face, use edge curved surface cut vector direction or screw type to enter, retreat a knife, such cutting tool will not leave the mark that be stationed in a knife in the place of knife of advance and retreat of workpiece surface, obtain fast face to machine quality thereby. To deep antrum treatment, screw type is cut is a kind of better feed way, use the helix method of identical or different radius, from indrawn other place material of progressively excision speech, suit deep antrum very much high speed treatment. Move treatment of knife high speed moves mediumly the knife is to point to the join means that transfers effectively between method of cutting tool of Shi Xianglin of tall feed speed. Treatment of parallel scanning surface is finish machining complex model a kind of method of the face. But this kind of method is light the abrupt change that causes feed in the extreme of method of every cutting tool. When feed speed moderate, method of simple annulus cutting tool is used to be able to alleviate appropriately between scanning method the abrupt change of turning point feed. But, when feed rate is higher, this kind of simple annulus motion is too abrupt still. Below this kind of circumstance, use between scanning method " golf club " type moves the knife is more effective. How does corner treatment realize efficient corner treatment, also be a when optimize cutting tool method important facet. Process work inside when acute angle, cutting tool method can use round part or circular arc takes a knife, corresponding ground reduces feed rate, can get smooth cutting tool contrail when machining corner so, the tall feed rate that can keep successive and the smooth stability that machine a process. Next the rudimental surplus of corner can pass purify of rework working procedure. Repeating treatment to repeat treatment is the treatment method that undertakes to the rudimental surplus of the spare parts specific aim is machined. In high speed treatment, repeat treatment to basically apply at 2 rough machining and drawing style milling and leftover milling. When using rough machining 2 times, undertake initiative rough machining first, calculate 2 times according to processing the form after next the mental allowance of rough machining. In contour line rough machining, because oblique plane exists on the spare parts, the meeting after treatment leaves chance to extricateoneself from an awkward position on oblique plane, bring about rudimental surplus thereby inhomogenous, cause cutting tool load inhomogenous. Use rough machining 2 times, can use the method that is different from initiative rough machining -- parallel law, corkscrewed yarn law, will achieve even surplus. Can maintain cutting tool effectively to undertake successive cutting so, decrease to take a knife for nothing, improve the treatment efficiency of finish machining. Drawing style milling basically manages the clear root operation at semifinishing machining, all corner of the part and groove remain after it passes cutting tool of large size of working procedure of the line before finding to machine, automatic drive cutting tool and two by treatment curved surface double cut, hand in line direction motion to machine these corner along its. The small size cutting tool that drawing style milling allows to use radius and 3D corner or groove photograph to match is one-time complete all clear root operations, can reduce the number that retreat a knife greatly. In addition, drawing style milling can carry rate of relatively constant the purify that cut bits, this is particularly important to high speed treatment. When finish machining contains the part of mural face and underside, if do not have drawing style milling, when cutting tool arrives at corner, will material of purify quite a few. When using drawing style milling, corner already was undertaken clear root is handled beforehand, the cutting tool when can reducing finish machining corner accordingly is deflective with noise. Leftover milling and drawing style milling are very similar. Working procedure of the line before leftover milling can be found uses the 3D that place of all sorts of different measurement cutting tool form face, and use a measure only lesser cutting tool will machine these surfaces. Of it and drawing style milling lie differently at it the whole face that is remain of the place after working procedure of the line before be opposite uses larger size cutting tool to machine undertakes machining, and drawing style milling undertakes to corner clear root is handled only. Efficient cutting law (HEM) is efficient cutting law (HEM) says again " Fukui Climbing " cutting law, a kind be rate of purify of implementation expensive stuff new efficient rough machining method. HEM is to pass " Fukui Method Cutting " (law of cutting of blessing well tall side edge) and " Climb Up Cutting " go up law of cutting climbing type) be able to come true. Law of blessing well cutting is Japan the law of milling of tall axial deepness that Fu Jingya as man of virtual and ability the professor puts forward, the 1 ~ that is cutting tool diameter through adjusting Z to cutting deepness 2 times, but efficient ground cutting gives perpendicular stair form rough workpiece appearance. After using blessing well law to machine, use again on law of cutting climbing type, the appearance that can make machine the surface and precision are close to the final treatment requirement of the spare parts more. When type cutting climbing on, use fine stair pitch to come face of stair of purify the rest, cutting tool begins from bottom, an one layer ground up cutting, stair pitch adjusts range for 0.

5 ~ 3mm, when treatment surface is steeper, can use wider stair pitch, machine the surface relatively at ordinary times, can use more detailed stair pitch. More than cycloidal type machines more than cycloid is to use high speed to machine material of purify of cutting tool side edge to improve the new technology of rough machining speed. When using more than cycloid to machine, cutting tool moves along the curve that has successive radius from beginning to end, use data of purify of successive of way of circular arc movement, have high speed to spare parts surface small cut deep treatment, avoided cutting tool effectively to cut workpiece to make cutting tool way with complete width. In motion of every annulus circular arc, workpiece of cutting of the cutting tool when forward movement, when moving backward, undertake cutting tool cools, allow free purify material. When process tall hardness data or using bigger cutting dosage, the refrigeration that the cutting tool in cutting tool method moves backward or circular arc of free purify material paragraph the treatment circular arc with forward movement paragraph photograph balance, realized condition of cutting tool cutting optimize. In addition, the cutting tool method that more than cycloid machines is comprised by circular arc motion entirely, walk along a knife to just do not have abrupt change up, a kind of ideal that is the thick, finish machining that is helpful for realizing high speed to machine machines a state. So, cycloidal type treatment is special all sorts of rough machining working procedure that apply to material of treatment tall hardness and high speed treatment (for instance housing machines) , can make the machine tool carries successive feed rate in whole treatment process not only, achieve high material purify rate, and can prolong cutting tool life. Inserting type treatment to insert type to machine is to use tailor-made insert type to machine cutting tool to undertake deep model antrum a kind of method of treatment. It is used get edge of method of the cutting tool that cut pattern the Z axis direction of machining center from material of deep antrum purify. This method is rough machining deep model antrum with a kind of when machine opposite more shallow housing with big diameter cutting tool effective method. The key that 3 choices get used to the cutting dosage that high speed machines to realize high speed cutting is to use high cutting rate, cooperate to be mixed with high feed rate small cutting deepness, can improve treatment efficiency not only, and can make cutting force is reduced, improve treatment quality thereby, prolong cutting tool life. Reasonable cutting dosage is having conclusive effect to cutting tool durability and workpiece treatment quality. Groovy rough machining and when using small size cutting tool to undertake mould rough machining, comfortable at using small cut give rate greatly with Gao Jin. When finish machining, fast and accurate cutting tool motion is helpful for realizing faster face to machine quality, the cutting tool of every block runs orbit shorter, height of dot of needle of treatment contrail surface is smaller, the spare parts rough sketch that treatment gives is more accurate. The basic parameter of cutting tool method chooses to will affect the exterior quality of finish machining. When finish machining, if load of cutting tool cutting namely every tine feed is equal to increment of knife step pitch, can obtain first-rate surface to machine quality; If load of cutting tool cutting and increment of step pitch taking a knife are unequal, the surface that machines is rougher. Be like face of planar, slope, curved surface and round face to wait in the light of feature of different spare parts appearance face, should use different feed. To win the outline external form of high accuracy, requirement feed motion cannot appear apparent lag phenomenon, will bring about cutting tool overheat otherwise and damaged. The 4 high speed that use high speed high accuracy machine a key to control a technology to use the key of high speed high accuracy to control a technology, be helpful for assuring the successful implementation that high speed machines. These crucial control technologies have treatment leftover analysis, wait for treatment to had been prevented orbit monitoring, automatically cut protection, needle to nod outline of control, high accuracy to control speed of interpolation of technology, NURBS, feed to optimize, editor of cutting tool contrail is optimized reach cut out test and verify of contrail of repair, cutting tool is waited a moment. It is OK to machine leftover analysis to machine remains to analyse a function cent separate out machines leftover exact position after cutting every time, allow cutting tool method to found on the area with complete without purify data of the workpiece in line working procedure. The cutting tool method of follow-up treatment can use treatment remains analysis to undertake optimizing getting on the foundation of method of cutting tool of advanced course working procedure. The certain and complex share that carries pair of workpiece outline undertakes machining leftover analysis, can maintain stable cutting parameter as far as possible, include to maintain the consistency of cutting ply, feed and cutting linear velocity. When encountering somewhere cutting deepness to increase likely, can lower feed rate, avoid laden change to cause cutting tool thereby deflective, and reduce treatment precision and exterior quality. Accordingly, machine leftover analysis to be able to realize high speed to machine parameter maximize, make cutting tool walks along cutter track diameter to get used to the change of workpiece surplus, reduce handling time, avoid cutting tool damaged to had been reached cut and rudimental phenomenon, realize cutting tool way thereby optimize. Wait for treatment contrail monitoring (Look-ahead) waits for function of treatment contrail monitoring (Look-ahead) is the feed rate that in be being used at monitoring to stay way of treatment cutting tool, causes as a result of method curvature is irregular transfer, and axial acceleration passes to wait for the change that goes against all sorts of treatment conditions of high speed treatment greatly, implement the method of a kind of control of speed of trends adjustment feed. Machine program is needed through scanning when CNC control system is undertaking machining controlling paragraph numerical control code, preview cutting tool method to go up to whether direction changes, corresponding ground adjusts feed speed. For instance, below tall feed speed, when waiting for function of treatment contrail monitoring to monitor corner, will reduce feed rate automatically, cutting tool is cut too or appear in order to prevent rudimental phenomenon. Be in those who wait for treatment contrail is flowing paragraph, raise feed rate quickly again the biggest. Carry rate of trends adjustment feed so, can optimize a machine tool to control dynamic function of the system, acquire tall treatment precision and exterior quality. Sharp drop controls what high speed machines controller to wait for treatment contrail monitoring (although Look-ahead) function can understand the cutting tool contrail that waits for treatment NC block beforehand, preview cutting tool contrail to reach its to walk along knife direction to whether have change, whether to put in corner namely, but every specific step pitch taking a knife that goes up to 3D spare parts and cutting surplus cannot foretell. When machining complex 3D face, can be calculated according to sharp drop highly the treatment step pitch of method of cutting tool of NC finish machining, is not to use constant treatment step pitch. Use a needle to nod control to undertake high speed treatment can realize successive exterior precision work, decrease go burr or working procedure of other handiwork finish machining, and can adjust knife step pitch according to trends of method of NC finish machining, make material purify rate keeps constant, cutting tool accepts strength condition more stable, the outside concussion load that makes cutting tool place gets is reduced the smallest. Had prevented automatically when cutting processing high speed to machine, before the mental allowance of working procedure bequeath will bring about load of cutting tool cutting to be increased suddenly, had appeared to cut even with phenomenon of cutting tool damaged. Cutting the attaint to workpiece too is not repairable, the destruction to cutting tool also is disastrous. Cut processing function through been prevent automatically, can protect the cutting process of cutting tool, realize the safe operation that high speed processes. High accuracy outline is controlled normally, in mould treatment, can use CAM system the method of system of other perhaps process designing, write a subprogram to undertake outline processes an operation. Consequently treatment information may exceed the memory capacity of CNC neutron program, and the likelihood needs undertake a variety of DNC process an operation. Below this kind of circumstance, if irretentive CNC high speed allocates the balance between processing and the subprogram feed rate that DNC manipulates, subprogram will cannot undertake feed is operated in time, and the flowing movement of the machine tool is couldn't get possibly also assure. System of CNC of high speed treatment can pass control of high accuracy outline to undertake high speed allocates handle and quicken automatically / decelerate processing. In the light of prep above convention the rotate speed of speed undertakes handle and allocation, can raise treatment precision, shorten working hours. The high speed of 5 models face and difficult treatment face machines politic high speed to machine engineering technology is one of crucial technologies that undertake high speed is machined successfully. If cutting method choice is undeserved, aggravate cutting tool wear away, the purpose that high speed of likely even and complete short of machines. Reach its according to the type of spare parts outline complex degree will choose appropriate treatment method, conduce to the high speed treatment with high grade and efficient implementation. 5.

Milling of 1 model face is complex when 2 dimension outline, no matter be outside outline or inside outline, should arrange cutting tool from tangential enter outline to undertake machining. After when outline treatment ends, cutting tool must continue to move along tangent direction the knife is retreated again after a paragraph of distance, can avoid cutting tool to go up in workpiece so cut nod and exit a dot to leave the mark that receive a knife. The circle outside milling can use straight formula tangential into, retreat a knife. When the outline inside treatment, can take circular arc form tangential into, retreat a knife. Machine straight grain face kind when workpiece, can use side mill means one knife shapes. Establish bodily form range commonly especially relatively flat large surface, can carry surface of press close to of milling cutter end panel to undertake machining with big diameter, such times taking a knife are little, leftover height is small. The passageway treatment that treatment space is restricted and the intermediate zone region that combine curved surface are machined, the cutting tool escape that can adopt larger measure is interfered, cutting tool tigidity is good, be helpful for raising treatment efficiency and precision. 5.

When treatment of deep antrum of 2 difficult treatment face machines the deep antrum that becomes by thin wall space face, all model antrum is not machined, and should take the kind that machines one part only every time, make place handsome antrum wall can maintain bearing in both sides. Thin wall treatment establishs milling cutter to machine Bao Bi when, the action of cutting force is easy those who bring about workpiece and cutting tool be out of shape. Accordingly, machine Bao Bi when, use small axial to cut deep repetition to carry milling, can gain constant edge radius and small cutting strength not only, reduce workpiece to be out of shape, and because cutting tool is prejudicial,won't appear the appearance error of generation. In addition, fast small when cutting part of deep treatment thin wall, the cutting tool of either face must maintain treatment thin wall to be down treatment all the time, till cross thin wall,begin new way taking a knife. Can pass those who approach point of cutting tool cutting to did not excise surplus to make Bao Bi maintains bearing in both sides so. When poor copy treatment processes the poor copy that does not have bearing, answer to begin to machine from the surface with least bearing first, cutting tool is carrying maintain all the time before the knife be down treatment, stand by to bearing stage by stage, machine the underside after to cannot be contacted with cutting tool photograph again. 6 epilogue machine quality of efficiency, treatment and cutting tool life to rise, make sure high speed machines success, high speed machines the cutting tool way that place of NC process designing makes, want to satisfy the high accuracy requirement of dimension and outline not only, a certain number of detail issues that still need to consider figure of different treatment working procedure, treatment face to wait for treatment process at the same time. According to the specific need that high speed machines, the way that actor picks cutting tool to cut work and move knife means, and milling of style of 2 treatment of actor choosing corner, rough machining, drawing, leftover milling, efficient cutting law HEM, more than cycloid is machined and insert type treatment to wait for treatment method; The choice gets used to the cutting dosage that high speed machines; The key that uses high speed high accuracy controls a technology; Be helpful for assuring the successful implementation that high speed machines. CNC Milling