Robot system and machining method with robot system

A robot system comprising:

• a movable arm including a plurality of links connected by joints and controlled by a robot controller having a software processing function;
• and
• a tool unit mounted on a distal end of said movable arm, having an additional rotation axis biased with respect to a final rotational axis of said movable arm and an effecting end biased with respect to said additional rotation axis and directed to said additional rotation axis, and a variable axis varying a position or a direction of the effecting end with respect to the final rotational axis of said moveable arm,
• wherein said variable axis of said tool unit includes a linear axis.

A method of machining a cylindrical workpiece with a robot system comprising a movable arm including a plurality of links and a wrist connected by joints and controlled by a robot controller having a software processing function, a cutting tool unit mounted on said wrist at a distal end of said movable arm, and having a cutting effecting end point biased with a radial offset with respect to a final rotational axis of said wrist and directed to said final rotational axis, and a variable axis varying a position or a direction of said cutting effecting end with respect to said final rotational axis of said wrist, said method comprising:

• (a) arranging the workpiece so that a central axis of the workpiece is aligned with the final rotational axis of said wrist;
• and
• (b) rotating said final rotational axis to perform cutting machining on the workpiece,
• wherein said variable axis of said cutting tool unit includes a linear axis.

A method of machining a pipe-like workpiece with a robot system comprising a movable arm including a plurality of links connected by joints and controlled by a robot controller having a software processing function, and a tool unit mounted on a distal end of said movable arm and having an effecting end and a variable axis for varying a position or a direction of said effecting end with respect to a final rotational axis of said movable arm, said method comprising the steps of:

• (a) arranging the workpiece so that a central axis of the workpiece is aligned with the final rotational axis of said movable arm;
• and
• (b) rotating said final rotational axis and driving said variable axis in synchronism with the rotation of said final rotational axis to perform a saddle-like cutting or forming a hole on the workpiece,
• wherein said variable axis of said tool unit includes a linear axis.