Method for the machining of grooves in the reveal of a relatively large drilled hole in a workpiece and a device for carrying out the method

摘要

The invention relates to a method and a device for the machining of rectilinear grooves, which in cross-section are semicircular, in the reveal of a relatively large drilled hole in a workpiece, in particular a drilled hole in the cylinder head or cylinder crank case of a diesel engine for receiving a roller tappet (follower) for a plug-in pump. When machining of the reveal of the relatively large drilled hole is complete the groove is then drilled by means of a drill guided in a drill-guiding part forming the device. The drill-guiding part is arranged on the drill head of a drilling machine, a shaped part, which is matched to the reveal of the drilled hole and is made of a material corresponding in machining characteristics to the workpiece material, being mountable eccentrically and parallel to the drill axis in such a manner on said drill-guiding part that its circumference coincides with the drill axis. As the groove is being drilled the shaped part is inserted with sliding-fit quality into the relatively large drilled hole, in a manner such that it covers the entire length of the subsequent groove, and is retained by a stronger force than the machining forces which occur. In the process, the drill, with its axis pointing in the longitudinal direction of the drilled hole, is lowered to the gap separating the reveal of the drilled hole, and the shaped part. By virtue of the method and device it is possible for semicircular grooves to be manufactured in any reveal cross-sections in a simple manner and, with only a low technical outlay, cost-effectively with high dimensional accuracy and surface quality being maintained.