Machining Method

摘要

Using a machine tool, a workpiece is machined while periodically varying the rotational speed of a spindle thereof. Correlation data on correlation between a speed variation rate RVA of the spindle rotational speed, a speed variation period ratio RVF thereof, and vibration of a tool when machining the workpiece while periodically varying the spindle rotational speed is previously obtained. Based on the correlation data, the speed variation rate RVA and the speed variation period ratio RVF are set so that the vibration of the tool and machining accuracy are within their respective allowable ranges, and based on the set speed variation rate RVA and speed variation period ratio RVF, a variation amplitude and a variation period of the spindle rotational speed are determined. The spindle is rotated at the rotational speed varying at the determined amplitude and period with respect to a target rotational speed, thereby machining the workpiece.

主权项

1. A machining method of machining a workpiece using a machine tool while periodically varying a rotational speed of a spindle of the machine tool, the machining method comprising:
obtaining in advance correlation data indicative of correlation between a speed variation rate RVA of the rotational speed of the spindle, a speed variation period ratio RVF of the rotational speed of the spindle, and vibration occurring on a tool during machining when the workpiece is machined while periodically varying the rotational speed of the spindle; setting values of the speed variation rate RVA and the speed variation period ratio RVF on the basis of the obtained correlation data so that the vibration of the tool is within an allowable range and machining accuracy is within an allowable range, and then determining a variation amplitude and a variation period of the rotational speed of the spindle on the basis of the set speed variation rate RVA and the set speed variation period ratio RVF; and rotating the spindle so that the rotational speed of the spindle varies at the determined variation amplitude and the determined variation period with respect to a target rotational speed, thereby machining the workpiece, wherein
RVA=NA/N0,andRVF=2τ/(N0×T), where T is the variation period [s] of the rotational speed of the spindle, NA is the variation amplitude [rad/s] of the rotational speed of the spindle, and N0 is the target rotational speed [rad/s].