Mitsubishi Kinzoku Kabushiki Kaisha

Ryoco Seiki Co., Ltd.

Kazuo Iizuka

Hiroshi Shimomura

Sueji Takaya

Makoto Harano

Akifumi Hamada

Katsuyoshi Karino

An insert rotary cutter for processing a metal workpiece includes a cutter body of a generally circular cross-section having an axis of rotation therethrough. The cutter includes one or more cutter inserts releasably mounted on a periphery of the cutter body. The insert includes a generally quadrilateral plate defined by a front face, a rear face disposed generally parallel to the front face and four side faces. The insert has a pair of main cutting edges defined by the front face and one pair of the opposite side faces. The pair of opposite side faces serve as respective rake surfaces for the main cutting edges. Each of the rake surfaces is convexly curved in such a manner that the width of the insert between the rake surfaces is larger at a central portion of each main cutting edge than at opposite ends of the main cutting edge.

Insert rotary cutter

An insert rotary cutter for processing a metal workpiece includes a cutter body having an axis of rotation therethrough. The cutter includes at least one cutter insert releasably mounted on an outer periphery of the body. The insert is of a generally polygonal shape having a curved front face. The front face has a pair of opposed marginal ridges serving as respective main cutting edges. The front face has marginal portions disposed adjacent and extending along the main cutting edges, and the marginal portions serve as respective rake surfaces for the main cutting edges. Each of the rake surface is convexly curved as viewed from a respective one of the main cutting edges and is concavely curved as viewed along a respective one of the main cutting edges.

An insert cutter includes a body having at least one generally radially outwardly-opening recess disposed adjacent a forward end face thereof. A cutter insert is received in the recess. The insert is a polygonal shape having a front face, a rear face and side faces. Each corner portion where adjacent side faces intersect each other is removed to provide first and second corner faces. The insert has main cutting edges each defined by the front face and a respective one of the side faces, auxiliary cutting edges each defined by the front face and a respective one of the first corner faces, and corner cutting edges each defined by the front face and a respective one of the second corner faces. Each side face serves as a flank of a respective one of the main cutting edges with a positive clearance angle A. Each first corner face serves as a flank of a respective one of the auxiliary cutting edges with a positive clearance angle B. Each second corner face serves as a flank of a respective one of the corner cutting edges with a positive clearance angle C. The angles A, B and C are so selected as to satisfy A&lt;B&lt;C. The disposition of the insert is such that one set of the main, auxiliary and corner cutting edges are indexed in their machining positions, and such that an effective clearance angle of the indexed corner cutting edge with respect to a workpiece is generally equal to an effective clearance angle of the indexed main cutting edge with respect to the workpiece.

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Warabi, Japan

Kazuo Iizuka