Whirl
The vertebrae is a The cutting manufacturing process and with respect to the tool and the kinematics (relative movement between tool and piece) is a special form of the profile milling . Whirling is done with a whirling machine or a lead screw lathe with a whirling attachment .
Procedure
The method is mainly used for the more cost-effective rough pre-machining before grinding in the case of rotationally symmetrical precision or shaped workpieces, such as. B. Ball screw spindles and nuts , pump spindles, eccentric, steering, EPS and gear worms as well as bone screws and special applications. A vortex ring with several cutting edges that are evenly distributed around the circumference acts as a tool . External whirling processes surfaces on the outside of the workpieces. The cutting edges on the ring-shaped tool are then directed inwards, and the workpiece is located inside the ring during machining. With internal whirling, however, the cutting edges are directed outwards and the tool is located inside a hollow workpiece.
variants
When whirling, a distinction is made between external and internal whirling.
External vortex
External whirling differs essentially from internal whirling in that the cutting edges are not directed outward but inward, so that external whirling can be described as milling with internally toothed cutters.
Internal whirling
With internal whirling, the tool rotates around its own axis in the bore of the workpiece; with simultaneous linear movement, the internal profile is created. Otherwise the internal whirling does not differ from the external whirling.
Cutting process and chip formation
With external whirling, the tool rotates around its own axis at high speed, thereby generating the cutting movement . The workpiece rotates slowly around its own axis and thus contributes part of the feed movement . The other part of the feed movement is generated by the tool, which also moves slowly in the direction of the workpiece's axis of rotation. The axes of rotation are offset, ie the tool rotates around an axis that is outside the center of the workpiece. In addition, the two axes are inclined towards each other. The angle of inclination corresponds to the thread pitch in the manufacture of threads or worms .