A method of finishing an internal combustion engine part having several valve seat structures and valve stem structures using a plurality of combination tools connected to a machine tool, each combination tool of said plurality of combination tools comprising a tool body;
- said tool body being connected to and disposed to extend from said machine tool;
- said tool body comprising:
- a rotational axis;
- a central portion being disposed immediately about the rotational axis of said tool body;
- a reamer, comprising a shank portion and a cutting portion;
- at least a portion of said shank portion being disposed in and held by said central portion;
- said reamer being configured to be rotated by said tool body to finish a valve stem structure in a part;
- a plurality of inserts being disposed on said tool body adjacent to said reamer and being configured to finish a valve seat in a part of an internal combustion engine;
- said plurality of inserts being radially spaced about and from said rotational axis;
- a plurality of fastening structures;
- said plurality of fastening structures comprising a first fastening structure;
- said plurality of fastening structures being essentially operationally identical to said first fastening structure;
- said plurality of inserts comprising a first insert;
- said first fastening structure being configured and disposed to fasten said first insert to said tool body;
- said plurality of inserts being essentially operationally identical to said first insert;
- said first insert comprising:
- a first surface comprising:
- a fastening hole being disposed substantially in the middle of and substantially perpendicular to said first surface;
- said fastening hole having a central axis which central axis at least substantially intersects said rotational axis of said tool body;
- a plurality of peripheral edges, said plurality of peripheral edges comprising a first, cutting edge and at least a second edge;
- and a center disposed substantially equally from all said edges;
- a second surface being disposed opposite said first surface;
- said second surface comprising a plurality of peripheral edges;
- a plurality of side surfaces extending from said peripheral edges of said first surface to said peripheral edges of said second surface;
- said plurality of side surfaces comprising:
- a first, cutting, side surface extending from said first, cutting edge;
- and a portion of a second, side surface disposed away from said first, cutting, side surface and extending from said second edge;
- each of said first surface and said second surface having a greater area than a surface area of any one of said side surfaces;
- said first surface of said first insert being disposed away from said second surface by a first distance;
- said first, cutting, side surface being disposed away from said portion of said second, side surface by a second distance;
- said second distance being substantially greater than said first distance;
- said plurality of inserts being fastened by said plurality of fastening structures to said tool body, such that said second surface is disposed to face toward said central portion of said tool body and also is in contact with said tool body;
- said first surface of said first insert is disposed to face away from said central portion of said tool body;
- said second surface and said cutting surface being configured and disposed to together form a third edge disposed opposite said first, cutting edge;
- said third edge of said first insert being disposed closer to said tool body than said first, cutting edge;
- said cutting edge of said first insert being configured to be disposed at an angle substantially parallel to an angle of at least a portion of the valve seat to be cut;
- and said first distance being sufficiently short, upon said plurality of inserts being fastened by said tool body using said plurality of fastening structures, to minimize vibrations of said first insert and also sufficiently short to permit absorption of vibrations generated by said first insert by said tool body;
- a straight line, which is at least generally perpendicular to said first surface of said first cutting insert, is configured to extend through sad central portion of said combination tool upon assembly of said first cutting inserts in said combination tool:
- said tool body comprising a first abutment against which said second side surface of said first insert rests during operation;
- and
- a substantially flat surface against which said second surface abuts during operation;
- said first fastening structure holding said second surface of said first insert against said substantially flat surface of said tool body, thereby permitting the distance between said tool bodies in said plurality of combination tools being disposed at a minimal distance between one another;
- said method comprising the steps of:
- disposing said second surface of said first insert against said substantially flat surface of said tool body;
- disposing said second side surface against said first abutment;
- thereby disposing said first surface of said first insert a minimal distance from said rotational axis and disposing said cutting edge a minimal distance from said rotational axis to minimize vibrations of said first insert and to absorb vibrations generated by said first insert;
- fastening said plurality of inserts to said tool body with said plurality of fastening structures;
- turning on said combination tools;
- rotating said combination tools;
- advancing said combination tools into the preformed holes;
- finishing a plurality of valve stem structures with said reamers while substantially simultaneously finishing a plurality of valve seat structures with said plurality of inserts;
- and
- removing said combination tools from the finished holes.