Deepness of crankshaft center aperture machines not stable solution

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  • source:FARSUN CNC Machining
1.

Of the problem put forward: Product line of some type crankshaft is cast formally postpartum, put in a problem all the time: In end panel of mill of OP10 working procedure, when drilling central hole, change every time after the center is gotten, the deepness of machining center aperture always appears circumstance of serious out of tolerance, cause treatment undesirable, need spends dimension to undertake adjustment to central hole depth. The fixed position of the foreword after serving as treatment is standard, its action is crucial. The depth of central aperture is differ, the treatment of the foreword after be being affected not only locates, make surplus of semifinished product rough machining distributings inhomogenous, and service life of cutting tool of the foreword after be opposite produces serious effect, appear unusual wear away or collapse caustic circumstance, process of the order after making appears in treatment process a series of harmful response. 2.

Machine craft introduction and case study: (1) treatment craft introduces. The treatment content of OP10 is mill two end panel, get flange of central aperture, harness an animal to cart and small head journal. Place is machining center of high speed of single tray horizontal with equipment, the machine tool controls a system to use system of Xi Menzi 840D, each axis collects the machine tool to have closed-loop control with grating feet, repeat fixed position error to be in 0.

01mm less than. Workpiece axial fixed position is standard for neck of the 3rd main shaft two stop choose a side, radial fixed position is standard for the first, neck of the 5th main shaft, use the fixed position of hydraulic pressure clamping apparatus from centering, clamp fixed position is reliable. Place is hard alloy material to pledge with central getting, use clamp of hydraulic pressure knife handle, do type cutting, broach can undertake weighing grinding. Central aperture deepness asks to be: It is the diameter 12.

The steel ball of 7mm puts park center Kong Zhong, measure a ball to support to be to the distance of flange end panel (6.

43 ± 0.

05) Mm, if pursue,1 is shown. Graph 1 crankshaft machines fixed position sketch map   (2) case study of out of tolerance of central aperture deepness. Feedback according to machining a process actually, after the circumstance of deepness out of tolerance basically is occurrence center aperture to change a knife every time, after adjusting qualification, size of the treatment inside knife cycle is being changed in is stable. Accordingly, basically adjust a respect to undertake the key is analysed in the light of cutting tool and machine program. From analysis of cutting tool respect. Place is hard alloy material to pledge with central getting, can undertake repairing grinding, guide part and 60 ° cone to undertake repairing grinding to central getting at the same time. Contrast repairs the discovery after grinding cutting tool and new cutting tool, long grind part of cutting tool guiding, the difference of length L existence that gets pointed top to cone cutting blade, repair the center that grind to get vertex angle and angle of 60 ° cone to also exist at the same time error, if pursue,2 are shown. Graph 2 centers get cutting tool cutting tool to adjust a respect, the knife that makes sure knife handle and scale of main shaft union get top to the center only grows dimension L1, use pair of Dao Yi to be measured accurately. The center gets measure of 60 ° cone sealed, support is repaired grind precision to assure. From analysis of machine program respect. Treatment flange carries central opening sequence to be as follows: M3 B90; of   of   of N1190 G0 G55 G60 G602 S2970===FLANGE_L1===(calling G55 coordinate is, main shaft is started)     N1200 STOPRE (the program stops read)   of   of Y=KOR[91] Z=((KOR[1])+(KOR[2])) of   of   of     N1210 TRANS X=-(KOR[92]) (to G55 coordinate the department undertakes slanting buy)     N1220 G0 X0 Y0 M52 (X/Y axis locates quickly to workpiece origin)     N1230 R1=-11.

5R2=2 R3=-12 R4=0.

1R18=1485 R19=297 of   of   of R10=2 R12=2970 R14=594 (parameter assigns)     N1240 L815 (call a subprogram)     N1250 G0 Z100 (Z axis answers quickly retreat)   among them L815 subprogram content is as follows: G0 Z=R2 (acquiesce calls cutting tool length to compensate D1, fast fixed position comes be apart from workpiece surface 2mm to be in) G1 Z=R1 of   of   of     S=R12 F=R14 (labour is entered define the position to R1 parameter) G1 Z=R3 of   of   of     S=R18 F=R19 (labour is entered define the position to R3 parameter, the deepness that central aperture asks) G0 Z=R10 S=R12 of   of   of     G4 F=R4 (point of a knife is answered retreat to safe plane)     RET (return program begin) analysis of   integrated above, can see by the program, cutting tool locates quickly use length of same cutting tool to compensate a value into the end to labour, the processes deepness to rely on a center to plunge point of a knife work of central aperture cone is controlled into deepness. Because cutting tool respect puts 2 in the graph to show inevitable error, and this error is to bring about the main factor that changes deepness of knife center aperture to be not stabilized every time. How to compensate a center to get the error between 60 ° cone and point of a knife to become the key that solves central hole depth to spend treatment to be not stabilized. 3.

Specific solution passes craft of pair of machining center aperture to undertake an analysis, computation goes out measure steel ball and central aperture the diameter of place of contact of 60 ° cone is 11mm, if pursue,3 are shown. Accordingly, the process is adjusted in cutting tool in, should measure blade of φ 11mm cutting accurately to combine the distance L2 of place to knife handle and main shaft only, build data of here cutting blade newly in parameter of machine tool cutting tool, call this length compensation in NC process designing, with respect to OK and accurate control central aperture machines deepness. Graph 3 flange carry central aperture deepness to undertake changing to machine program, the cutting tool length when L1 of data of blade of the first cutting has fast fixed position with Yu Dao only is compensated, when cutting tool turns into labour to enter, call length of the 2nd cutting tool to compensate L2, make labour of blade of φ 11mm cutting is entered to the graph 3 balls that show steel and central aperture union are in, made sure central hole depth spends dimension qualification. When the knife has a knife, measure and print a center to get φ 11mm to manage high data, change every time when cutting tool, grow data to undertake changing to data of the cutting tool in the machine tool according to printed knife, make the data of compensation of length of the 2nd cutting tool of cone of aperture of the machining center after changing a knife and length of actual cutting tool consistent, ensure the accord of treatment, stable. The machine program after changing is as follows: M3 B90; of   of   of N1190 G0 G55 G60 G602 S2970===FLANGE_L1===(calling G55 coordinate is, main shaft is started)     N1200 STOPRE (the program stops read)   of   of Y=KOR[91] Z=((KOR[1])+(KOR[2])) of   of   of     N1210 TRANS X=-(KOR[92]) (to G55 coordinate the department undertakes slanting buy)     N1220 G0 X0 Y0 M52 (X/Y axis locates quickly)     N1230 R1=-2.

6R2=2 R3=-3.

R4=0 of 1     .

1R18=1485 R19=297 of   of   of R10=2 R12=2970 R14=594 (treatment deepness parameter assigns afresh)     N1240 L815 (call a subprogram)     N1250 G0 Z100 (Z axis answers quickly retreat) content of subprogram of the L815 after   changes is as follows: G0 Z=R2 D1 (acquiesce calls cutting tool length to compensate D1, fast fixed position is in to workpiece surface 2mm) G1 Z=R1 D2 of   of   of     S=R12 F=R14 (use the 2nd knife to grow compensation, labour is entered define the position to R1 parameter) G1 Z=R3 D2 of   of   of     S=R18 F=R19 (use the 2nd knife to grow compensation, labour is entered define the position to R3 parameter, the deepness that central aperture asks) G0 Z=R10 S=R12 D1 of   of   of     G4 F=R4 (call D1 compensation afresh, point of a knife is answered retreat to safe plane)     RET (return program begin)     4.

Machine effect test and verify: Machine test and verify through changing a knife for many times continuously, size of central aperture depth satisfies tolerancepublic errand to ask, all be inside acceptance area. Improve the result apparent, because cutting tool repairs the treatment out of tolerance that grinds consistency problem to bring about,eliminated, improve the treatment that change a knife first percent of pass, effectively disappear is machined besides this undesirable the effect that the foreword after be opposite produces, raised product quality and rate of route system actuate. 5.

Epilogue: To central aperture machine program and cutting tool respect undertake systems analysis, perfected primary treatment program. Pass analysis, computation, built new cutting tool to measure, adjust reach control level, eliminate error of cutting tool oneself, satisfied treatment requirement. To a few otherer the control of place of high accuracy treatment provided similar experience and means, aborning has bigger draw lessons from a meaning. Origin: Author of Inc. of Great Wall car: Liu Jiangang CNC Milling