1 overview at the beginning of 90 time, industry of our country machining realizes what Electromechanical unifinication had different rate to old-style machine tool to transform. When we are sharing this work, anatomize the actual condition of the factory, act on economize, reduce the principle that transforms cost, use a number to control a system to take the main control equipment of electric machinery as the pace, undertook transforming to machining the milling machine of sole decorative pattern, shortened thereby machining is periodic, rose to machine precision and manufacturing efficiency. Control system sees a picture 1. If carry sheet,CAM labour of the system decides piece engine control finishs, odd the machine program according to the input has an opportunity all sorts of operation such as interpolation produce feed, the technology that combines by soft hardware photograph realizes pulse allocation, output a series of pulse signal, course result puts drive pace to work into electric machinery, realized the treatment that cutting tool moves according to formulary curve contrail. Graph 2 systems design block diagram of system of control of open loop of 1 personal computer odd a pace of engine work principle have output moment of force into electric machinery bigger, drive precision of simple, control is tall, easy wait for an advantage with digital circuit interface, in transforming a process, we use functional price to compare reasonable sheet piece microprocessor system µPS, form direct output pace to need drive signal into electric machinery place. X to, Y to, Z carries sheet into electric machinery to the pace piece µPS program parts to obtain drive pulse signal from inside expanded I/O interface circuit (Fx, Fy, Fz) , positive and negative turns selection signal (Sx, Sy, Sz) , buy, use at drive of drive motive instrument (ball guide screw) change is linear displacement, undertake the position and speed are controlled. Because the pace takes the step of electric machinery movement,number is a several decisions that develop by drive arteries and veins. Want to change the electrify position of winding ceaselessly only according to principle of this one job so, the pace can press formulary way movement into electric machinery. Should decide sheet piece machine brilliant brace up when, the highest frequency of pulse signal also decided. The design is single an all sorts of different electrify kind that engine order takes the step electric machinery winding according to process designing of binary encode list (see) issueing a list, carry out the statement checking a watch of different number, the frequency that outputs pulse also changes subsequently. Graph 2 it is block diagram of program of gamete of cent of X way pulse. Graph 2 X allocates watch address code to be worth electrify order to pulse of block diagram of pulse allocation subprogram (A, B, C)TAB+10BH100TAB+209H110TAB+30DH010TAB+40CH011TAB+50EH001TAB+60AH101 notes: 1 -- electrify 0 -- cut off the power milling machine treatment and the milling machine after controlling software to transform can accuse to operate with the hand, also can adopt automation of computer process designing. Deserve to be executive component into electric machinery with the pace from hardware; Develop computer CAD/CAM program from software, the made controller that makes treatment. The software parameter that sole decorative pattern machines basically is according to craft requirement and department of light industry ministry promulgate standard process designing, by systematic PC (go up a machine) after computation, communication gives sheet piece machine (leave an opportunity) executive control pace finishs into electric machinery. The bottom kind that the CAD software of the design has big to rubber overshoes background undertakes batten curve plans to close, frame design and the function that beg node of aleatoric and flat curve; Have pattern of sole lofting, decorative pattern design, spell the function that combines design and seriation design; Have the function that graphical commutation, map designs in couples; Have computation to display the function that machines contrail of cutting tool motion; Have data processing and transmit cutting tool contrail the function that has machining to I/O interface directly. Considering the system the design is open loop control when executive treatment, its precision relatively the problem with closed circuit poor system, use seesaw pattern to input craft parameter, workpiece to machine a setting absolutely at 0 o'clock, the course of certain treatment craft, accumulation that eliminates rounding error the method such as effect and clearance compensation will solve. Among them the method of parameter of craft of seesaw pattern input is different to machining decorative pattern deepness, facilitating clew handlers and a kind of adoption convenience method; The setting is absolutely because open loop control is done not have,the method 0 o'clock is reliable absolutely at 0 o'clock, data bulk of decorative pattern board is great, handling time is longer, get a taper hole to regard pair of knives as the dot on pattern plate then (graph 3) , process designing adds man-hour to always be treatment start with this bits, give out automatically to arrive to process the idle stroke instruction of start actually by this bits, when accident circumstance appearing in machining a process so, have the capacity that resumes treatment. Machining craft course is decided by geometrical model database, be machine efficiency to rise, course of idle stroke of hope cutting tool as far as possible the short, method that decreases to the curve machines the backlash of the process and be used as far as possible. The accumulation that eliminates rounding error effect and clearance compensatory method are controlled in open loop is indispensable in the system. Because treatment statement uses opposite coordinate process designing, every instruction needs to be opposite is not a pulse equivalent the part undertakes rounding off is taken whole, inevitably meeting has rounding error to appear, in treatment Shi Reshe accumulates a quantity to increase into the error, will affect the treatment quality of sole decorative pattern severely. The choice uses absolutely coordinate to process data, the pulse that the terminus that a curve records between the curve when process designing goes to to go actually to knife dot several, the pulse that the start of a curve goes to to should go to knife dot several, regard the idle stroke between the curve as number with this both difference. The pulse number that can make sure from numerical value to each curve start location is given out so is accurate, restrict rounding error inside a curve thereby. Basically be direction of judgement treatment distance to the compensation of transmission clearance, when certain reference axis accepted retrorse statement, before this reference axis is undertaking pulse allocation is controlled, call clearance to compensate a subprogram, give out a certain quantity of clearance to compensate feed pulse, make workbench crosses transmission clearance automatically, move by instruction pulse again next, eliminated transmission clearance error. Graph graph of the outline outside sole of 3 two dimension is like unexpected power failure in processing contingency, break a knife to wait, wanting an attention to suspend the position is not the position of accident happening, deciding accident happening to be inside which instruction is very important. The record is nodded to the knife, after changing a knife, be opposite afresh dot, appoint instruction serial number to transmit data afresh, design software can have jumped automatically to appoint the instruction before the condition, need not save the current information of cutting tool position, release partial storage space quickly, this method is right processing contingency effective. After technical reformation of old equipment of main technique index, main technique index is: The pace is into equivalent of electric machinery pulse 0. 01. The greatest distance is axis of X, Y, Z × 600mm of 5000mm × 3500mm. The biggest radius that when machining circular arc, allows is 2800mm. Knife dot is tangential new ≈ of athletic speed V (7/9)V is old. This speed cent is 30 class, 0 class are lowest is 9.
20mm/min, 29 class are the superlative degree is 200.
00mm/min, class difference is about 6.
00mm/min(among them circular arc treatment allows top speed to be 20 class, linear treatment allows top speed to be 29 class. Fast fixed position can move along reference axis direction only, its motion speed does not accept level restriction, can achieve directly 320.
00mm/min) . Odd a Memory in µPS can accommodate user program to make an appointment with code of Ⅱ of 9000 ASC at most. Effective treatment curve and academic curve are in law up the biggest error is less than 0.
4 pulse equivalent. Treatment diagonal is OK linkage of linkage of 3 reference axis, two reference axis, machining circular arc is direction of X, Y linkage of two reference axis. Design of 3 interference rejection machines quality to assure, wait for a circumstance considering element of the environment of industrial spot, interference, in design and debugging a process, the method that controls a system to use soft hardware to supplement each other to µPS undertakes preventing disturbing designing, basically use below 4 kinds of methods: Use Gao Kang to violate sexual power source. Change 2 times distribution is entered machine when job shops, already restrained the circuit of most advanced interference in electrified wire netting through a few effective ground. The switch power source that chooses limits of voltage of low function, job to fight faze function widely, high is the power source of the computer, with respect to the quality that can assure power supply source. Use " total surplus is empty " technology. Photoelectricity is used to keep apart a technology between the I/O interface of µPS and result discharge road, make its ground wire independent, arise and conduct of signal in order to restrain interference. Use " independent passageway " technology. "Float is empty " although the technology can be restrained effectively in all modular interference, but insufficient to eliminating the electromagnetism all round industrial spot to disturb ability, wave of screen, filter, disappear is used to tremble on hardware etc use on method and software manage by different levels pilot means, restrain this kind of interference effectively. Use " modular " design method. Work out software with modular design method is given priority to, complementary in order to interrupt, wave of filter of redundant, data, prevent a program to run fly, data bales etc defend interference measure, rose to transform systematic dependability further thereby. The practice that 4 last words transform to old milling machine makes clear: Overall processability can stabilize ability of reliable, interference rejection strong, facilitating maintenance and breakdown processing. Manufacturing efficiency rose than before 70% . CNC Milling
CNC Machining