The requirement of high speed milling to CAD/CAM system

Because use small cutting deepness and ply, the cutting of every blade measures cutting tool dinky, at the same time heat in metal cutting is cut for the most part bits is taken away. Consequently of machine tool main shaft, slideway get power small, the cutting tool life, precision life of the machine tool is lengthened; ⑵ .

Although cutting deepness is mixed ply decrescent, but as a result of main shaft rotate speed tall, feed is fast, because this makes the metal inside unit time excises a quantity to increase instead, treatment efficiency also rises, economic performance improvement; ⑶ .

Add man-hour to be able to combine thick, half essence, precision work for an organic whole, finish on a machine tool entirely, because install clip to make precision produces an error for many times,avoid at the same time; ⑷ .

Can machine tall hardness (can amount to HRC62) difficult treatment material, can improve the treatment technology of the mould consequently, can process the semifinished product with good temper by dipping in water directly, cancel electric spark to machine working procedure, applicable CAD/CAM technology comes to repair mould in the meantime, shorten greatly the mould makes time; ⑸ .

High speed cutting stimulates Zhen Pin to lead natural frequency of outclass machine tool, because this machining complex is oscillatory small, at the same time because cutting force is small, especially radial cutting power decreases considerably, accordingly, improved mould surface quality greatly. My company introduced machining center of milling of VCP1000 high speed from Swiss MIKRON company 2000, undertake the high speed cutting of the curved surface such as stem horn mouth antrum is machined, obtained very good result. To high speed milling, making treatment way is rotate speed of input main shaft and feed speed not merely for certain, implement a system next beforehand the treatment of set circulates. Process designing personnel must consider whole craft order, he not only the characteristic that should master CAD/CAM system, and should understand machine tool system, be familiar with material function and the character that machine a method individually. To treatment of high speed cutting, feed speed and main shaft slewing speed compare a tradition want many tall, minor error may cause serious consequence. Cutting of simple specification high speed is opposite below the requirement of each level that CAD establishs model and CAM process designing. The HSC requirement to CAD system 1.

The requirement of model precision: HSC process only then at design phase, end at working procedure of the last milling. If the spare parts establishs the set when the model big geometrical common difference, or curved surface did not cut out appropriately, what data changes is missing wait, reaction creates exterior section in treatment workpiece admiral, rupture and outline mistake. 2.

The unifinication of systematic data asks: In good condition curved surface data to good exterior quality it is very indispensible. The data interface that should use a convention (IGES or VDAFS) when changing outside system data, people cannot be read in via often can coming up against data or of curved surface data missing. This often brings about long data mending. Use new standard (STEP, or onefold kernel system, be like PARASOLID) or the direct interface between two systems is current right way. The NextpageHSC requirement to CAM system if process designing personnel had had in good condition data, he can need a lot of skill with CAD/CAM system comfortable the craft at HSC. Oriented to a knowledge, the CAD/CAM system that has a lot of academic knowledge, must the content that can consider graph A place integratedly to involve. How does the description come workpiece treatment the method of the appearance of the requirement and strategy below. Normally, this process can be divided for 3 parts, namely rough machining, semifinishing machining and finish machining. To these 3 all parts, machine to HSC especially, cutting condition should as far as possible stable. The HSC condition of process of ◆ rough machining: Rough machining is one comparatives geometrical appearance simple work (semifinished product) treatment is become approach final work appearance as far as possible (complex 3D geometry form) process. Major material is excised in this process. In this process exterior quality is mixed outline precision is not particularly important. And it is the most important that cutting tool wears away, because, even if the cutting condition that obtains very hard also below best condition stabilizing, also want to consider the efficiency of treatment at the same time, harmonious cutting movement is very significant to cutting tool life, and the abrupt change that must avoid to machine direction as far as possible. What harmonious cutting motion points to is the cutting amount that keeps even, compare constant cutting direction and cutting linear velocity, maintain suitable mill as far as possible at the same time. Ought to avoid abrupt directional change, because this is met slowdown or make machine dead stop. Of feed stop to be able to cause the acuteness clash between cutting tool and workpiece, it can reduce cutting tool life quickly, lay cutting tool of can complete as a result of overheat attaint in extreme circumstance even. According to above item, the rough machining of HSC asks to the process designing of CAM 1, maintain stability to cut mix greatly of less fluctuant scope cut wide. 2, round horn increases to transfer in the turning point of knife course. If pursue 1, graph 2. 3, cutting tool is when workpiece interior feed, should from beginning to end with corkscrewed yarn or the oldest point of view the diagonal feed of 5 ° . The HSC condition of ◆ semifinishing machining process: Semifinishing machining is the preparation of pair of final figure, and the finish machining surplus with certain reservation or say the model slants buy. The main task of this operation is smooth arrange part of the rest needle and material of purify the rest. Accordingly, its mission is the material with unnecessary treatment. An excellent CAD/CAM system can identify the function of material of rough machining the rest automatically, undertake semifinishing machining for 2 semifinished product with this. Can help reduce handling time and cost of managing cutting tool. Semifinishing machining should arrange the rough machining face that has steps leading up to a house solely. The purpose of semifinishing machining is in all treatment the surface arises to slant equably buy quantity, as far as possible the steady cutting volume that assures finish machining, this finish machining to the success is must. In real work, process designing personnel is right the importance of this process often underestimate, because more process designing time are a flower,go up in rough machining and finish machining. Inadequate semifinishing machining will be right the exterior quality when finish machining, outline precision and cutting tool life produce negative effect. According to above item, the semifinishing machining of HSC asks to the process designing of CAM 1, should go up in outline directly feed comes next plane. If impossible word, must with corkscrewed yarn or diagonal feed comes next plane. 2, identify material of rough machining the rest automatically, can help reduce handling time and cost of managing cutting tool. 3, the mental allowance with treatment surface even generation, this bit is the most important. Graph 3 with the graph 4 choices machine parameter likewise, adopt different treatment method, produce different knife course, graph course of this kinds of 4 knives is better. The HSC condition of process of ◆ finish machining: Finish machining is the last pace of workpiece treatment process. Its purpose is the optimal surface mass that reachs a requirement and appearance precision. The commonnest circumstance is, knife course is appearance of according to outline, can hold directional mutation and slick cutting tool campaign as far as possible so. Hypothesis semifinishing machining is good, can use optimum cutting rate and high feed rate, the cutting tool damaged that because because load changes,can eliminate,the reason brings about, break off. Too high cutting rate, too small every blade feed or not stable surplus can make cutting blade coating burns to make material is destroyed as a result of overheat (it is especially in the treatment of sclerotic material) . Nextpage basis above item, the finish machining of HSC asks to the process designing of CAM 1, the milling that avoids corner as far as possible moves 2, the feed outside shunning work as far as possible and the motion that retreat a knife. Enter next deepness from outline directly. If impossible word, use corkscrewed yarn moves by outline or inclined to motion. 3, every blade feed (Fz) ought to corresponding at radial feed (Ae) , corresponding at different material. 4, milling of true leftover wave crest, the Ra estimation of the heart of cutting tool ball that goes up with contacting a dot with the appearance calculates cutting tool to slant buy (step pitch) 5, constant every blade feed can get first-rate surface quality, the longest cutting tool life. 6, Xiang Shi is measured and true leftover wave crest machines the law according to the surface is not value of step pitch of computation of cutting tool vector. What this will maintain cutting is constant and without giving thought to the curvature of curved surface, get those who stabilize more cut bits load, special when change of curved surface curvature more ground is close to when alternating between upend and level. 7, the HSC condition of procedure of accurate processing of postposition of CAM of model data ◆ : HSC asks to the postposition processing module of CAM software best operation method, the accurate knife course, modification interface that operates easily, according to the precision of different machine tool the setting adjusts postposition to handle interpolation of line of batten of program, support, high speed, accurate imitate treatment. So the word of 5 axes machine tool had better support a space three-dimensional compensatory computation. The knife course of HSC compares groovy treatment method, cut deep, cut wide a lot of smaller, program volume is compared commonly big, need compares long operation time, reason postposition processing uses optimized computational method to be able to save many operation time. Because HSC is the treatment precision with groovier cutting higher demand, bright and clean,spend, different machine tool has precision of different the smallest interpolation, different interpolation precision can produce different result, if postposition handles what module installs too small or cross congress to produce disparate result, cut too even. So postposition processing can produce very exact knife course. CAD/CAM system should have what operate easily to revise an interface, according to the precision of different machine tool the setting adjusts postposition to handle an order. Because HSC cutting asks to achieve better precision, the precision tolerance of program of course of curved surface knife is very small, between block very close, below high-speed feed rate, function of the look up before groovy machine tool and acceleration are used not quite exceedingly with respect to what show, the intermittent halt that can produce cutting tool to move in cutting process, what can affect treatment greatly so is bright and clean degree, lower the service life of cutting tool apparently. Reason can produce the CAD/CAM system of batten line interpolation to be able to remedy certain machine tool flaw. High speed, accurate imitate is machined, also be need to HSC, can have offerred cut a warning, cross those who cut area to generate, analysis. So machine tool of 5 axes linkage, three-dimensional compensation calculates development space to deeper model the clear root of stage of antrum, protruding can shorten greatly the length of cutting tool, those who improve treatment is bright and clean degree, efficiency and prolong cutting tool life. Above just is opposite in the light of HSC the condition of CAD/CAM and requirement. Of course, successful HSC, not only the CAD/CAM that has had, still must according to the target, consider each content of graph A integratedly, decide course of first-rate HSC craft thereby, get first-rate result. Conclusion: Compare with conventional technology photograph, treatment of high speed milling is a kind of new-style treatment craft, it not only have special demand to machine tool and knife, and wait to have special demand to direction of spare parts model, method taking a knife, feed. Perfect further as CAD/CAM system, be sure to promote high speed processing technique to develop at full speed. CNC Milling