Combined machining tool and machining method using same

A combined machining tool comprising:

• a shank that has its rear end to be mounted on a processing machine;
• a burnishing part that is arranged on the shank and burnishes an inner peripheral surface of a workpiece;
• and
• a reaming part that is arranged in front of the burnishing part and executes reaming
• wherein the burnishing part comprises:
• a mandrel that is fixed to the shank and has an outer peripheral surface in a tapered shape;
• rollers that are arranged on the outer peripheral surface of the mandrel;
• a frame that holds the rollers so as to be rollable on the outer peripheral surface of the mandrel;
• an adjustment member that presses the frame axially from one end thereof to adjust its axial position with respect to the mandrel;
• and
• an elastic member that is arranged axially on the other side of the frame to support the frame, and
• wherein the reaming part comprises:
• a base part that is detachably attached to the mandrel;
• and
• a machining blade that is formed integrally with the base part,
• wherein a hole part is formed in the mandrel to have inside a tapered surface whose diameter decreases rearward, and a cylindrical part is formed in the base part so as to be fitted into the hole part, to have outside a tapered surface whose diameter decreases rearward, so that the diameter of the tapered surface of the hole part is smaller than that of the tapered surface of the cylindrical part.

A machining method using a combined machining tool including:

• a shank that has its rear end to be mounted on a processing machine;
• a burnishing part that is arranged on the shank and burnishes an inner peripheral surface of a workpiece;
• and
• a reaming part that is arranged in front of the burnishing part and executes reaming
• wherein the burnishing part includes:
• a mandrel that is fixed to the shank and has an outer peripheral surface in a tapered shape;
• rollers that are arranged on the outer peripheral surface of the mandrel;
• a frame that holds the rollers so as to be rollable on the outer peripheral surface of the mandrel;
• an adjustment member that presses the frame axially from one end thereof to adjust its axial position with respect to the mandrel;
• and
• an elastic member that is arranged axially on the other side of the frame to support the frame, and
• wherein the reaming part includes:
• a base part that is detachably attached to either the shank or a member which is connected to the shank;
• and
• a machining blade that is formed integrally with the base part,
• the method comprising:
• reaming the inner peripheral surface of the workpiece by the reaming part while guiding the inner peripheral surface by the rollers.