Method of machining crankshaft

A method of machining a crankshaft from a workpiece with opposed ends of the workpiece clamped by a pair of chucks using a rotating cutter to mill and thereby machine journal and pin portions of the workpiece successively, said method comprising:

• providing a phase positioning jaw in one of said pair of chucks;
• clamping the opposed ends of the workpiece with both of said pair of chucks, with said one of said chucks in which said phase positioning law is provided being at a position at which said phase positioning jaw and said cutter do not interfere with each other;
• thereafter
• milling and thereby machining a first journal portion in said workpiece with said cutter;
• unclamping both of said pair of chucks and then advancing said one of said chucks in which the phase positioning jaw is provided, and establishing a phase position of said workpiece with said phase positioning jaw;
• clamping again the opposed ends of said workpiece with both of said pair of chucks;
• and thereafter
• milling and thereby machining all remaining journal and pin portions other than said first journal portion in said workpiece, in succession with said cutter, so that all of the journal and pin portions are machined with a single crankshaft miller unit.

A method of machining a crankshaft from a workpiece with opposed ends of the workpiece supported by a pair of centers and clamped by a pair of chucks using a rotating cutter to mill and thereby machine journal and pin portions successively in the workpiece, said method comprising:

• providing a phase positioning jaw in one of said pair of chucks;
• establishing a phase position of the workpiece with said phase positioning jaw;
• clamping the opposed ends of the workpiece with both of said pair of chucks;
• and thereafter
• milling with said cutter, thereby machining the journal and pin portions of said workpiece in succession, except a first journal portion that is located at a position at which said phase positioning jaw and said cutter interfere with each other;
• unclamping the one of said chucks that is provided with said phase positioning jaw and retracting said chuck to a site at which said jaw and said cutter no longer interfere with each other;
• clamping one of said centers that is located proximal to said first journal with said one of said chucks that is provided with said phase positioning law;
• and thereafter
• milling and thereby machining said first journal portion with said cutter, so that all of the journal and pin portions are machined using a single crankshaft miller unit.

A method of machining a crankshaft from a workpiece with opposed ends of the workpiece supported by a pair of centers and clamped by a pair of chucks using a rotating cutter to mill and thereby machine journal and pin portions successively in the workpiece, said method comprising:

• providing a phase positioning jaw in one of said pair of chucks;
• clamping one of said centers that is located proximal to a first journal portion of the workpiece with the one of said chucks that is provided with said phase positioning jaw at a position at which said phase positioning jaw does not interfere with said cutter, and clamping said workpiece at an opposite end with the other one of said pair of chucks, thereafter
• milling and thereby machining a first journal portion in said workpiece with said cutter;
• unclamping both of said pair of chucks and then advancing said one of said chucks that is provided with said phase positioning law, and establishing a phase position of said workpiece with said phase positioning jaw;
• clamping again said workpiece at the opposed ends of said workpiece with both of said pair of chucks;
• and thereafter
• milling and thereby machining all remaining journal and pin portions other than said first journal portion, in succession in said workpiece with said cutter, so that all of the journal and pin portions are machined with a single crankshaft miller unit.