Feed control method in a numerically controlled machine tool

DETAILED DESCRIPTION The present invention was accomplished in view of the above situation.
It is, therefore, a general object of the present invention to provide a feed control method in a numerically controlled machine tool wherein a total machining time can be shortened.
That is, the present invention is based on the finding that a tool or a workpiece can be fed more rapidly by cut feed than rapid feed if it is within a range of a certain distance.
In the case that a cut feed is commanded in a first step of a machining program, a rapid speed feed is commanded in the succeeding second step thereof and a cut feed is commanded once again in a further succeeding third step thereof.
In the case that a moving amount in the second step is within a range of a distance in which a tool or a workpiece can be fed more rapidly by cut feed than rapid feed, the feed in the second step is effected by cut feed.
Thus, according to the present invention, in the case it is judged that a tool or a workpiece can be fed more rapidly by cut feed than rapid feed, the tool or the workpiece is fed by cut feed.
Accordingly, the present invention has the advantage that total machining time is shortened to that extent.