How to solve numerical control machine tool to machine the breakdown with unusual precision?

Systematic parameter produces change or alter parameter of 　 　 system basically includes unit of machine tool feed, slanted at 0 o'clock buy, backlash is waited a moment. For example system of numerical control of SIEMENS, FANUC, its feed unit has metric and imperial two kinds. The machine tool repairs a process in certain processing, often affect slanted at 0 o'clock the change of buy and clearance, breakdown processing ends answer to timely ground is adjusted and be revised; On the other hand, because serious or mechanical wear is concatenate,become loose to cause the change that parameter actual measurement is worth possibly also, need to do corresponding modification ability to satisfy a machine tool to machine the requirement of precision to parameter. 2.

The treatment precision that mechanical failure brings about is unusual 　 　 machining center of horizontal of a THM6350, use system of FANUC0i-MA numerical control. It is in the process of milling turbine lamina, discover Z axis feed is unusual suddenly, cause at least the cutting margin of error of 1mm (Z to cut too) . The understanding in investigation arrives: Breakdown happens suddenly. The machine tool is moved in the dot, it is normal that each axis moves below MDI mode of operation, and it is normal to wind reference point; Do not have any calling the police to hint, the possibility of hard breakdown of electric control part eliminates. The analysis thinks, basically answer one by one of the following respects to undertake checking. (1) the machine program that the examination is running when machine tool precision is unusual paragraph, especially coordinate of compensation of cutting tool length, treatment is (G54 ～ G59) proofread reach computation. (2) means is moved to fall in the dot, move repeatedly Z axis, the course is inspected, touch, listen to be diagnosed to its movement condition, discover Z to athletic voice unusual, nod quickly especially move, noise is more apparent. Judge from this, mechanical respect may be put in hidden trouble. (3) precision of axis of Z of examination machine tool. With axis of Z of shift of generator of hand arteries and veins, (it is fold of hand arteries and veins 1 × surely of 100 block, namely every change one pace, electric machinery feed 0.

1mm) , cooperate dial gauge to observe the athletic condition of Z axis. Serve as initial drop after one-way motion precision keeps normal to motion, hand arteries and veins every change one pace, the actual distance D=d1=d2=d3 that axis of machine tool Z moves... =0.

1mm, explain electric accident travel is good, fixed position precision is good. And return a machine tool on the change of virtual campaign displacement, can divide for 4 phase: Motion of ① machine tool is apart from D1>d=0.

1mm (slope is more than 1) ; ② is shown for D=0.

1mm> D2>d3 (slope is less than 1) ; Orgnaization of ③ machine tool did not move actually, show most standard backlash; Distance of motion of ④ machine tool and set-point of hand arteries and veins are equal (slope is equal to 1) , renew the normal campaign of the machine tool. No matter how be opposite backlash (parameter 1851) undertake compensating, the trait that its show is: Outside dividing ③ phase to be able to be compensated, other each paragraphs of change still occurs, especially the treatment precision that ① phase affects a machine tool badly. The discovery in compensation, clearance compensation is bigger, ① paragraph mobile space is larger also. Analyse afore-mentioned examinations, numerical control mechanic grooms think when to exist likelihood reason: It is electric machinery has unusual; 2 it is mechanical respect has trouble; 3 it is the clearance with constant presence. To diagnose breakdown further, electric machinery and guide screw complete come away, undertake checking to electric machinery and mechanical part respectively. Electric accident travel is normal; In the discovery in be being diagnosed to mechanical part, with the hand dish when moving guide screw, return motion initiative have very apparent vacant feeling. And below normal circumstance, should feel bearing is orderly and flowing shift. Via tearing open check to discover its bearing already was damaged truly, and a ball falls off. The machine tool after changing returns to normal. 3.

Electric parameter did not optimize the machine tool electric machinery runs unusual 　 　 milling machine of vertical of a numerical control, deploy system of FANUC0-MJ numerical control. In machining a process, discover X axis precision is unusual. The examination discovers X axis is put in certain clearance, and the existence when electric machinery is started does not stabilize a phenomenon. With the feeling when the hand feels X axis electric machinery electric machinery shakes more serious, open when stopping not quite apparent, below JOG means more apparent. The analysis thinks, breakdown reason has at 2 o'clock, it is mechanical backlash bigger; 2 it is X axis electric machinery the job is unusual. Use the parameter function of FANUC system, undertake debugging to electric machinery. Undertook compensating to the clearance of existence above all; Adjust servo gain parameter and N pulse to restrain functional parameter, of X axis electric machinery shake eliminate, the machine tool machines precision to return to normal. 4.

Annulus of machine tool position unusual or control 　 of logistic and inappropriate 　 machining center of milling machine of boring of a TH61140, numerical control system is FANUC18i, means of full closed-loop control. In machining a process, discover precision of axis of Y of this machine tool is unusual, precision error is the smallest in 0.

006mm left and right sides, the biggest error can be achieved 1.

400mm.

In the examination, the machine tool had set department of G54 workpiece coordinate according to the requirement. Below MDI means, with G54 coordinate the department runs a paragraph of program namely " G90G54Y80F100; M30; " , the mechanical coordinate value that indicates on the monitor after waiting for a machine tool to run an end is " - 1046.

605 " , the record leaves this value. Move means to fall in the hand next, rod of machine tool Y the dot uses other and aleatoric position, carry out the statement above below MDI means again, after waiting for a machine tool to stop, number of coordinate of machinery of the machine tool when discovering this shows a value to be " - 1046.

992 " , the several indication values after be being carried out with first time are compared differred 0.

387mm.

According to same method, y rod the dot uses different position, carry out this statement repeatedly, count the indication adventitious that show. Undertake detecting to Y axis with dial gauge, discover mechanical position is real the error shows shown error to agree basically with number, think breakdown reason repeats fixed position error for Y axis thereby too big. Undertake microscope to the backlash of Y axis and fixed position precision, make compensation afresh, all do not have the effect. Because this suspects grating feet and systematic parameter to wait,have a problem, but why to produce so big error, did not appear to call the police accordingly however information? Check discovery further, this axis is the axis of perpendicular direction, when Y axis is loose, main shaft box is down, caused out of tolerance. To the PLC of the machine tool control program did logic to revise, it is namely when Y axis is loose, make Y axis first can to load, loosen Y axis again; And when clamp, first axial clamp hind, make Y axis again can take out. Breakdown of the machine tool after adjusting is able to solve. CNC Milling CNC Machining