Machining device and machining method

A machining method for using a machining tool having a rotation axis, an intersection angle of which can be changed with respect to a rotation axis of a workpiece, and cutting a peripheral surface of the workpiece by feeding the machining tool relatively in a direction of the rotation axis of the workpiece while rotating the machining tool synchronously with the workpiece,

• a tooth of a gear having both side wall sections of a first groove and a second groove as tooth flanks being formed on the peripheral surface of the workpiece, and aside surface on one side of the tooth of the gear including a first tooth flank, a second tooth flank having a torsion angle different from a torsion angle of the first tooth flank, and a third tooth flank having a torsion angle different from the torsion angles of the first tooth flank and the second tooth flank and formed to extend to the second tooth flank further on an end surface side of the tooth of the gear than the second tooth flank,
• a side surface on another side of the tooth of the gear including a fourth tooth flank, a fifth tooth flank having a torsion angle different from a torsion angle of the fourth tooth flank, and a sixth tooth flank having a torsion angle different from the torsion angles of the fourth tooth flank and the fifth tooth flank and formed to extend to the fifth tooth flank further on the end surface side of the tooth of the gear than the fifth tooth flank,
• the machining method comprising:
• a first step of first setting the intersection angle to a first intersection angle to at least roughly cut the first tooth flank and the fourth tooth flank;
• a second step of subsequently changing the intersection angle to a second intersection angle to machine the third tooth flank and changing the intersection angle to a third intersection angle to cut the sixth tooth flank;
• a third step of subsequently changing the intersection angle to a fourth intersection angle to machine the second tooth flank and changing the intersection angle to a fifth intersection angle to cut the fifth tooth flank;
• and
• a fourth step of finally changing the intersection angle to the first intersection angle to finish the first tooth flank and the fourth tooth flank.

A machining method for using a machining tool having a rotation axis inclined with respect to a rotation axis of a workpiece and cutting a peripheral surface of the workpiece by feeding the machining tool relatively in a direction of the rotation axis of the workpiece while rotating the machining tool synchronously with the workpiece,

• the peripheral surface of the workpiece including at least a first groove and a second groove having torsion angles different from each other, and
• the machining tool having a torsion angle of a blade trace of a cutting blade of the machining tool corresponding to the torsion angle of the first groove or the second groove to be capable of cutting the first groove or the second groove,
• the machining method comprising:
• a calculating step for calculating, concerning each of the first groove and the second groove, a correction angle with respect to a rotation phase of the workpiece based on a distance reaching a cutting completion position from an approach position of the cutting of the first groove or the second groove through a cutting start position and the torsion angle of the first groove or the second groove;
• a setting step for setting an intersection angle of a rotation axis of the workpiece and a rotation axis of the machining tool to a predetermined value;
• a first cutting step for controlling synchronous rotation of the machining tool and the workpiece to be shifted by the correction angle of the first groove or the second groove and cutting the first groove or the second groove;
• a storing step for storing, as a reference rotation phase, a rotation phase of the machining tool and the workpiece during the synchronous rotation at this time;
• and
• a second cutting step for controlling the synchronous rotation of the machining tool and the workpiece to be shifted by the correction angle of the remaining first or second groove with respect to the reference rotation phase and cutting the remaining first groove or the second groove.