The breakdown of system of numerical control of W200HD of boring milling machine is safeguarded

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  • source:ACHER CNC Machining
W200HD of 1 breakdown phenomenon is Wu Gang the milling machine of boring of a numerical control that the company imported from Czech 1994, in be used, no matter take much further space,discover a machine tool, the distance that its coordinate shows and the distance that detect actually always have certain error, achieve a few millimeter sometimes, even ten millimeter. The phenomenon with bigger error of this kind of fixed position, make numerical control machine tool cannot be machined normally. 2 breakdown analysis and the numerical control system that W200HD of milling machine of boring of processing breakdown analysis distributes are the SINUMERIK system of company of German Xi Menzi, it is a kind intermediate numerical control system, have function of linkage of 3 reference axis, resolution is 1µm. To this kind of system, appear afore-mentioned errors are abnormal. This system itself is had diagnose a function oneself, however afore-mentioned breakdown were not shown on monitor come, need is judged artificially and try to eliminate. Graph error of fixed position of block diagram of principle of control of 1 feed position dominates medium main index as the position, but control of position of judgement of more comprehensive ground is normal. Can sentence the position that decides system of machine tool numerical control to controlled a part to appear by breakdown phenomenon problem, make the fixed position error of system of whole closed circuit too big, affect the normal treatment of the machine tool. In the graph 1 shows foundation of block diagram of principle of pilot of closed circuit position to go up, undertake brief analysis to principle of feed position pilot. Install the positional sensor on machine tool workbench (here is grating) will mechanical displacement is changed into digital pulse, this pulse sends to the position of numerical control system to measure interface, by tally computation, the computer is worth sampling to this feedback with fixed time cycle, sampling value and the result that interpolation program outputs (dictate currently namely the position) undertake comparative, get position error, gain of software of this error classics magnifies (Kc) , output gives digital-to-analogue converter (D/A) , offer control voltage for servo unit, drive workbench moves to the way that reduces an error. If interpolation program has feed generation ceaselessly, workbench follows ceaselessly this feed moves, it is zero hour in position error only, workbench just stops to asking locally. This shows, by software and hardware two parts realize positional control function jointly, software is in charge of the computation of position error and speed annulus set-point, hardware accepts set-point number amount, undertake D/A is changed, offer control voltage for speed annulus, drive reference axis moves, give numerical control the system the positional feedback of machine tool workbench. Analyse the provenance of the problem according to breakdown phenomenon. This machine tool is system of full closed-loop control, positional sensor installation is on workbench, error of theoretic fixed position does not suffer the effect of guide screw clearance and pitch error. The machine tool can move normally, it is normal to explain unit of machine tool servo works. In loop of machine tool feedback, if feedback line opens circuit, the system becomes open loop actually, feedback without the position, increment subtracts from inside commanding increment, follow the error can be accumulated more and more greatly, till spill over, make actuating device out of control, diagnose a function of numerical control system to be able to produce effect oneself at this moment, give out what feedback loop disconnects to call the police information. Integrated above analysis can see, part of positional pilot hardware does not have a problem, consequently breakdown may go out in software part. Graph position of system of 2 numerical control controls software flow the servo unit of this machine tool is achievable the control of voltaic annulus and speed annulus. And positional annulus (accession buy is controlled) finish by software of numerical control system. Software of numerical control system has hundreds parameter to be able to be installed by the user, match 2 received development at numerical control system and machine tool noumenon with benefit, these parameter all protect existence CMOS to put store implement in, after the machine tool drops report, parameter won't be missing, once batteries is insufficient (can make parameter missing under the 85%) of rating or exterior interference and produce a disorder. But call the police without what occurrence batteries is not worth, the energy that shows cell is enough still. If the control parameter of numerical control system is all missing, criterion the machine tool moves far from possibly, because this is probable,be external some kind of interference, make parameter of positional pilot part produces a disorder, computation of positional pilot software appears bigger error, make locate the error exceeds a limit. From the graph 2 see, the precision that the positional feedback of the machine tool surveys a system and Kc of positional annulus gain affect the output of position error. Positional annulus gain reflected the sensitivity of whole servo, in the system stable premise falls, gain is taller, fixed position error is smaller, but the machine tool is easy oscillation, adjust not easily; Systematic gain is smaller, fixed position error is bigger, but the machine tool is adjusted easily, not easy oscillation. Show the systematic parameter of system of v numerical control, whether is the gain that checks positional link chosen too lowly, make fixed position error bigger. Via proofreading, the gain after the gain of positional annulus and machine tool had been debugged is consistent. Accordingly, the problem of this machine tool may feedback in the position of the machine tool the position of the precision that surveys a system and control equipment adjusts precision does not match on. Because this machine tool uses position of complete closed circuit to control a system, it is direct from component of machine tool shift (workbench) on obtain the position to move actually value, accordingly its detect the effect that precision does not suffer mechanical drive precision. Want to make positional annulus can work normally, must have proper place to adjust closed circuit loop. The position of the pulse that must make for this the position surveys a system and control equipment adjusts precision matchs each other. There is to be able to install parameter MD5002(in this system in all 8) , state feedback inputs resolution and positional control resolution, when the setting that inputs precision when feedback only and the setting that the position controls precision match each other, positional annulus ability may be correct operation, make the machine tool moves normally, accurate inside the range that the error permits arrive appoint the position. In CNC system, the computation of fixed position error is an unit with servo resolution, if the precision of positional feedback input and positional pilot precision are abhorrent, the computation of position error is in be not what undertake below unified unit, its are not the error of the statement position on real significance and real position as a result, consequently workbench cannot reach the place that instruction place asks. Breakdown processing is analysed according to above breakdown, v system parameter, proofread the content of parameter unit MD5002, discovery and the parameter that had debugged so have discrepancy, the likelihood is exterior some kind of interference, make the parameter in RAM produces a disorder. After undertaking this parameter be modificationed correctly now, make restoration of system of machine tool numerical control, reopen uses a machine tool, via detecting, the fixed position precision of the machine tool achieved normal demand, the machine tool resumed normal production. 3 brief summary are safeguarded through this breakdown visible, to can be filled cent develops function of numerical control machine tool much, flexible precision of strong, treatment the dominant position with automation tall, high rate, production gives the product of high quality, in order to get used to the need that the market competes, the maintenance that must notice to strengthen numerical control machine tool works. Specific when should accomplish as follows: (1) makes sure the use environment of numerical control equipment is favorable, accord with the requirement that the product sets. (2) notices numerical control equipment uses the maintenance of power source. Special when increase and decrease on the side common when the high capacity equipment of alternating current source, must observe whether to produce instantaneous to disturb signal, prevent it to destroy the program inside machine or parameter, create dead opportunity even, those who affect a machine tool is normal move. (Equipment of 3) numerical control is due operating rules. Special prevent machine tool operator to revise in-house parameter at will. (4) is due maintenance log. Breakdown of common machine tool has regularity () of breakdown of as usual hair, maintenance log has direct sense to will working henceforth. (5) wants to strengthen personnel of technology of equipment of concerned numerical control and operator groom the job, combinative theory and practice will improve their integrated business quality. CNC Milling CNC Machining