METHOD OF DETERMINATION OF MAXIMUM PERMISSIBLE VALUE OF MAIN COMPONENT OF CUTTING FORCE FOR SURFACE GRINDING IN COMPLIANCE WITH CAPACITY OF SPINDLE DRIVE

摘要

FIELD: mechanical engineering. SUBSTANCE: invention is meant for automated design engineering system used in grinding for calculation of cutting modes providing most productive grinding. maximum permissible value of main component of cutting force is determined through maximal power used directly for grinding and actual speed of grinding wheel which is then diminished by several per cent to ensure failure-free operation of machine. Power M used for rotation of spindle under idle condition is measured in advance by electric instruments while machine runs, then sample is ground and increase of cutting mode power M used for rotation of spindle is brought to value at which protective relay operates switching off machine. At moment of machine switching off power M and actual rotation speed of spindle are measured simultaneously. After this value of main component of cutting force is calculated by formula , where N_max is power used to rotated spindle at moment of operation of protective relay, W; N_id.r is power used to rotate spindle under idle run, W; π-is ratio of circumference of a circle to its diameter; D is outer diameter of grinding wheel, m; n_act is actual rotation speed of spindle at moment of operation of protective relay, s^-1; k_res is safety factor of power. 20 per cent growth of precision of determination of power is achieved with the use of this method. EFFECT: increased precision of determination of main component of cutting force while grinding with due account of losses for operation of machine under idle run and of calculation of desired force by actual parameters of process.