The reasons for the increase of the hole diameter in the deep hole drilling of the die are as follows: the design value of the outer diameter of the reamer is too large or the reaming cutting edge has burr; the cutting speed is too high; the feed rate is improper or the machining allowance is too large; the main deflection angle of the reamer is too large and the reamer is bent; the reaming cutting edge is adhered with chip tumor.
When grinding the cutting edge, the deviation of the reaming edge is out of tolerance; the cutting fluid is not suitable; the oil on the surface of the taper shank is not cleaned or the taper surface is bruised when installing the reamer; the flat tail of the taper shank is installed in the spindle of the machine tool and the taper shank interferes with it; the spindle is bent or the spindle bearing is too loose or damaged; the reamer is not flexible in floating; the two hands are not even when the spindle is different from the workpiece and the hand reaming hole makes the reamer shake left and right 。
The solution to the increase of the hole diameter in the deep hole drilling of the die: reduce the outer diameter of the reamer properly according to the specific situation; reduce the cutting speed and adjust the feed or reduce the machining allowance properly; reduce the main deflection angle and straighten or discard the useless reamer bent.
Carefully trim to be qualified with oilstone; control the swing difference within the allowable range; select the cutting fluid with better cooling performance; before installing the reamer, clean the oil stain inside the taper shank of the reamer and the taper hole of the machine tool spindle, and polish the cone surface with oilstone if there is any collision; adjust the flat tail of the reamer or replace the spindle bearing; readjust the floating head and adjust the coaxiality; pay attention to the correct operation.