1 the preface
In large engineering machinery factory grinding surface roughness Ra0.02 a 0.04 u m, precision h4 a shaft neck h5 is expensive high precision grinding machine. But general engineering machinery plants but no high precision grinding machine, to grinding of such a low surface roughness, so high shaft neck precision is very difficult. We in the existing equipment M131W common cylindrical grinder on a lot of testing, and the necessary test, to blow grind and adjusted by dressing and delicate balance grinding wheel, in the grits right on the whole out more micro-edge, high accuracy completely realized, low roughness of grinding pins, can effectively grinding out a precision h4 h6, roughness Ra0.02 a 0.04 u m parts. The method is simple, convenient and feasible, effect is very good.
2 ultra precision grinding mechanism
Ultra precision grinding wheel on the work by a lot of the same height as dressing grinding blade of the characteristics and micro to conduct. These micro-edge can work on the surface from small, still have removed some trace defects and trace shapes and sizes error and surplus. Therefore, use the micro cutting tools such as is the number of, if grinding appropriate dosage, in processing surface may leave a lot of extremely slight cutting trace, so can get very low surface roughness. In addition, because without the light in spend grinding stage, and still have very clear to the friction, slippery crowded, polishing and pressure light effects, and allowing processing the surface roughness of the secret to further reduce.
3 for ordinary grinding machine maintenance
In order to work out in flexible grinding Ra0.02 roughness a 0.04 u m workpiece, deal with the old flexible grinding machine make the following project detection, do not accord with the requirement of accuracy, it will blow grind overhaul.
(1) maintenance bed guide
1) how detection and scrape lathe bed V guide: in the vertical plane within the is not straight degrees, in 1 m in length, and shall not be more than 0.01 mm; In the plane of the not straight degrees, in 1 m in length, and shall not be more than 0.01 mm; And slide saddle guide is not perpendicular, 250 mm in length, shall not be longer than 0.02 mm; The contact point 12 14 points requirements (25 × 25) mm.
2) the detection what scraping the lathe bed plane guide: V guide not equal degrees, in 1 m in length, and shall not be more than 0.02 mm; In the vertical plane within the is not straight degrees, in 1 m in length, law more than 0.01 mm; Contact a 14 points 12 spots requirements (25 × 25) mm.
(2) maintenance slippery saddle guide
1) how detection and scrape slippery saddle V guide; In the vertical plane within the straightness, all the length shall not be longer than 0.01 mm; Contact a 12 o 'clock 10 spots requirements (25 × 25) mm.
2) how detection and scrape board saddle flat guide: V guide not parallel degrees, in all the length shall not be more than 0.02/1000 mm; Contact a 12 o 'clock 10 spots requirements (25 × 25) mm.
(3) adjust wheel spindle and bearing clearance
In the wheel spindle and axle bush turn the trunnion tu research, with scraper blow grind bush put table face, contact spot should achieve some 12 a 14 points (25 × 25) mm, then install adjustment, will wheel spindle and location of gap adjusting to 0.0025 a 0.005 mm. Such, can overcome in grinding workpiece edged circle appeared in the ills.
(4) balance wheel spindle motor and the wheel
Due to the vibration of the wheel spindle motor on the surface roughness of the impact, so wheel spindle motor need after balance, grinding wheel should be carried out two balance; Diamond grinding wheel with pen nap after a rough balance, reoccupy oil-stone or thick after the close of the car wheel after the nap of do a fine balance.
4 fine, fine twice the grinding wheel how
For grinding workpiece can reach the surface roughness Ra0.02 a 0.04 u m, use the following two kinds of methods work fine, fine two dressing grinding wheel.
(1) with the diamond ShiBi refinement, again with pure car of the grinding wheel after fine wheel, can satisfy a rough surface Ra0.4 0.8 u m request, to Ra0.02 grinding out a 0.2 u m is very difficult. But, if use diamond pen refinement after another, with pure car of the grinding wheel after fine, it can achieve the request.
When the fine can be used TL60 # ZR1 a ZR2 wheel diameter lower than 100 mm or so. First the grinding wheel clamping at a heart shaft, again in precision lathes with pure outside, round, in order to eliminate partial put. In grinding machine for fine after the grinding wheel, which USES the grinding wheel fine grinding wheel sand office.
Dressing grinding wheel when rely on head frame with rotation, its speed to low, mfert for 80 a 100 r/min, the small when, reciprocating a mfert for 0.002 mm, workbench reciprocating movement speed is lower than 0.3 m/min, subject to many times the reciprocating right. Dressing grinding wheel and be trimmed grinding wheel rotation direction, that is, both the contact point of the linear velocity in opposite directions. The cooling fluid to fully for the floating sand developed, prevent the grinding process have float sand workpiece surface galling.
The grinding wheel pass fine, fine two nap after grinding wheel on the grits can trim out more micro-edge, grinding wheel dressing to end, again with brush be trimmed to remove the sand surface grinding wheel. Before grinding, cooling fluid to strictly filtering. Grinding, cooling fluid to fully, prevent to burn the surface.
(2) with the diamond ShiBi refinement, reoccupy oil-stone fine repair
Use first sharp single grain diamond pen refinement, big grinding wheel grits can fix on the more micro-edge, reoccupy oil-stone (or article sand) fine repair, namely in the refinement, and on the basis of the grinding wheel in the grits trim out more micro-edge.
A diamond pen refinement, grinding wheel dressing for the installation should correctly (figure 2). But feed must not be more than 0.005 mm every time, longitudinal feeding the proposal with the lowest. In the dressing grinding wheel process, must pay attention to listen, to hear even the rustle of is the best. If you hear and high and low, increasing gradually low, and even issued a doodle of abnormal noise, you should check whether the reptile, cooling fluid is abundant, diamond pen is sharp. After diamond pen refinement followed by the oil-stone for fine repair. In fortunately the grinder oil-stone with grinding wheel to wear away. Fine repair, wheel circumference must oil-stone surface equality, touch, slowly




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