A cutting insert includes a top face and a bottom face parallel to the top face. Four side faces and four corner faces extend between the top and bottom faces. At least one cutting edge is formed at an intersection of the top face and at least one of the corner faces and two of the side faces connected to the corner face. The top face forms a rake surface, while an upper part of the corner face and the two side faces form a relief surface connected to the cutting edge. In order to reduce the cycle time for crank shaft milling, the cutting insert has two diagonally opposed corners including an acute angle between 70 and 85. At least one of the acute angled corners including the corner face providing a corner cutting edge. A disc milling tool including such cutting inserts is also provided.

A cutter performs milling on a crankshaft blank having a journal and a counterweight coupled to the journal. The cutter includes an annular main body part, a first chip, and a second chip. The annular main body part is centered on a predetermined axis center. The first chip is attached to a circumferential surface of the main body part and is used to cut an external circumferential surface of the journal. The second chip is attached to the circumferential surface of the main body part and is used to cut a groove on the external circumferential surface of the journal.

A cutter performs milling on a crankshaft blank having a journal and a counterweight coupled to the journal. The cutter includes an annular main body part, a first chip, and a second chip. The annular main body part is centered on a predetermined axis center. The first chip is attached to a circumferential surface of the main body part and is used to cut an external circumferential surface of the journal. The second chip is attached to the circumferential surface of the main body part and is used to cut a groove on the external circumferential surface of the journal.

A method of manufacturing a crankshaft includes the steps of: (1) forming a crankshaft blank via a first half and a second half; (2) measuring a plurality of surface variations between a predetermined surface in a first region and a corresponding predetermined surface in a second region of the crankshaft blank; (3) calculating centering offset data based on the plurality of surface variations; (4) machining a pair center holes based on the centering offset data; (5) machining a counterweight and a journal relative to the pair of center holes to produce a partially machined crankshaft; (5) milling and grinding the partially machined crankshaft to produce a finished machined crankshaft; and (6) rotating the finished machined crankshaft typically on the outermost main journals in a final balancing machine and then modifying the counterweights to eliminate undesirable vibration generated during the rotation and engine operation.

A method of manufacturing a crankshaft includes the steps of: (1) forming a crankshaft blank via a first half and a second half; (2) measuring a plurality of surface variations between a predetermined surface in a first region and a corresponding predetermined surface in a second region of the crankshaft blank; (3) calculating centering offset data based on the plurality of surface variations; (4) machining a pair center holes based on the centering offset data; (5) machining a counterweight and a journal relative to the pair of center holes to produce a partially machined crankshaft; (5) milling and grinding the partially machined crankshaft to produce a finished machined crankshaft; and (6) rotating the finished machined crankshaft typically on the outermost main journals in a final balancing machine and then modifying the counterweights to eliminate undesirable vibration generated during the rotation and engine operation.

An internal milling cutter includes a carrier disk having a centre axis defining an axis of rotation of the milling cutter, a plurality of separated tool holder segments removably mounted at the inner circumference of the carrier disk, and at least one clamp for each tool holder segment mounted either on the carrier disk or on the tool holder segment. Each of the tool holder segments at its inner circumference includes at least one cutting insert seat with a mounting element for a cutting insert or at least one cutting edge. The clamp is located and arranged such that it generates a force in the axial direction pressing the axial contact surface of the tool holder segment onto the axial abutment surface of the carrier disk, and the clamp is mounted movably in a radial direction of the carrier disk between a locking position and a releasing position.

An internal milling cutter includes a carrier disk having a centre axis defining an axis of rotation of the milling cutter, a plurality of separated tool holder segments removably mounted at the inner circumference of the carrier disk, and at least one clamp for each tool holder segment mounted either on the carrier disk or on the tool holder segment. Each of the tool holder segments at its inner circumference includes at least one cutting insert seat with a mounting element for a cutting insert or at least one cutting edge. The clamp is located and arranged such that it generates a force in the axial direction pressing the axial contact surface of the tool holder segment onto the axial abutment surface of the carrier disk, and the clamp is mounted movably in a radial direction of the carrier disk between a locking position and a releasing position.

A forged crankshaft assembly for an engine, and a method of manufacturing the same, has a forged crankshaft and a removable counterweight to provide access for core drilling or milling a cavity. The forged crankshaft has a pin bearing journal, a main bearing journal, a first crank arm supporting the pin bearing journal, a second crank arm supporting the pin bearing journal and connecting the pin bearing journal and the main bearing journal, and at least one milled crank arm cavity formed within at least a portion of the second crank arm. The removable counterweight extends radially outward from the first crank arm, wherein the crank arm cavity is configured to be accessible to a core drill or mill cutter only when the removable counterweight is removed from the first crank arm and inaccessible to the core drill or mill cutter when the removable counterweight is coupled to the first crank arm.

A machine for machining workpieces, including a first column and a second column facing each other according to a first horizontal axis, a guide system guided displacement of at least one of the columns in parallel with the first horizontal axis, one or two tool units, each tool unit being arranged on respective column for controlled displacement perpendicularly to the first horizontal axis, on each column, a workpiece holding device, at least one of the workpiece holding devices being arranged for controlled displacement in parallel with the first horizontal axis, where the workpiece holding devices are arranged for supporting a workpiece between them and for controlled rotation of the workpiece around a workpiece axis parallel with the first horizontal axis.

A machine for machining workpieces, including a first column and a second column facing each other according to a first horizontal axis, a guide system guided displacement of at least one of the columns in parallel with the first horizontal axis, one or two tool units, each tool unit being arranged on respective column for controlled displacement perpendicularly to the first horizontal axis, on each column, a workpiece holding device, at least one of the workpiece holding devices being arranged for controlled displacement in parallel with the first horizontal axis, where the workpiece holding devices are arranged for supporting a workpiece between them and for controlled rotation of the workpiece around a workpiece axis parallel with the first horizontal axis.