How to eliminate the lathe machining problem of vibration and shock dao?

Published on 2018-03-27

Vibration in lathe processing knife problem, cause the workpiece surface is quiver, rework rate, high rejection rate.Machine tool vibration reason is general machine tool, cutting tool, workpiece three systems in one or more system insufficient rigidity, said first below vibration and shock when the knife needs to be from what aspects.1. Screening points artifacts (1) class of cylindrical turning slender shaft;General cutting point distance from the clamping point, if the length to diameter ratio of more than 3 would be easy to knife, can consider to change the process.(2) cylindrical turning of thin-walled parts.(3) the box parts are turning (such as sheet metal welding structure).(4) superhard material cutting.2. The tool reason (1) using the molding form turning blades;(2) the Angle of the cutting tool, especially the main Angle, Angle, rake Angle, etc.;(3) the sharp edge degree;(4) the tip arc radius is too large;(5) the appropriate cutting parameters.3. Machine tool reason (1) live center is too long (2) bearing has been damaged and continue cutting first rule out the problem of cutting tool rigidity check tool itself, not clamping?Stretched out too long?Gasket uneven?Check tool wear (boring cutter)?Whether the blade edge or repair the light blade too wide?After turning Angle is too small?Have a look at you now have 90 degrees of knife or 45 degrees, try to change.And feed (feed) is too small, also may cause fibrillation is a kind of grain cause, can increase a little slightly adjusted.You adjust the rotation, single-pole cutting depth and feed have a down and out of resonance point.Screening machine tools and charging (1) to find your card parts live center was stretched out too long, bearing is good or not.There is a plane rolling bearing combination.Really doubt, dead center, can be used in using, pay attention to the center hole of grease lubrication.(2) find your tailstock clamping situation, the clamping is in the up and down or so, and under the condition of machine tool spindle different heart.(3) pull the medium plate are tight, especially in the plate.(4) if it is machine tail part you temporarily unable to check (1, 2 points, requires some fitter basis), can try to tail away from the card to catch end knife.The car, can eliminate the end not to force to the greatest extent.(5) if the step 4 and situation, to look at the spindle, of course, so three grasp, also want to check, whether spiral groove is damaged.Four grasp the is artificial, don’t need to check.Comprehensive countermeasures of vibration suppression knife if your main shaft tile has been really tight in place, nor thin-walled workpiece or long overhanging, chuck clamping.USES other vibration suppression countermeasure.Based on the study of vibration principle, the current is applied to the process of some more specific and practical ways: (1) to reduce the vibration caused by the part of the work of weight, inertia as small as possible.(2) in view of the vibration of the largest local shall be fixed or clamping, such as the center, work holder etc.(3) improve the rigidity of processing system such as using high elastic coefficient of the handle or use to join the Dynamic vibration absorber (Dynamic Damper) special seismic force, to absorb the impact energy.(4) from the blade and working direction of rotation.(5) the change of cutting tool shape and Angle, tool Nose Radius Radius, (Nose) as small as possible, in order to reduce the cutting resistance.Roll Angle (Sick Rake Angle) must be positively, in order to make more nearly vertical cutting direction.Angle (Back Rake Augle) best positive, but a very chip to chip ability is relatively poor, so generally can choose slot punishment knife to make the Angle turned negative, but still retained when the cutting effect.(the original title: how to eliminate the lathe processing of seismic knife problem?)(source: front nc technology)