Mitsubishi Materials Corporation

Mitsubishi Kinzoku Kabushiki Kaisha

Mitsubishi Metal Corporation

Masayuki Okawa

Masaaki Nakayama

Osamu Tsujimura

Tatsuo Arai

Junichi Saito

Hidehiko Nagaya

Hidehisa Shiratori

Kazuya Yamazaki

Keiichi Nishiyama

Hiroshi Shimomura

Yoichi Ishikawa

Yasunori Murakami

Takamasa Shimano

Yuzo Koesashi

In an interference fit type cutting tool according to the present invention, a head section and a shank section are fitted together by shrinkage fitting. The shank section is provided with a shaft portion and a taper portion. The head section is provided with a hole portion to be fitted on the shaft portion, and a tapered portion to be fitted on the taper portion. The hole portion and the tapered portion have an interference, and the inner diameters thereof are smaller than the outer diameters of the shaft portion and the taper portion. Two-surface restraint is established by fixing the shaft portion and the hole portion, and the taper portion and the tapered portion with the interference pressure by shrinkage fitting. A key is formed on the leading end face of the shaft portion, a key groove is formed in the bottom face of the hole portion, and the key and the key groove are fitted together. Side faces of the key and the key groove are nearly orthogonal to the principal force of cutting resistance, thereby enhancing dynamic stiffness.

Interference fit type cutting tool

A boring tool includes a concave groove formed on the outer peripheral surface of a tool body on the side opposite from a cutting blade with respect to an axis of the tool body. The concave, groove 10 is formed so as to extend from a position x, which is separated rearwardly from a front end face of a head portion, toward the rear side, and to be open downward from above a rake face. Furthermore, a sub-groove is formed between the concave groove and a chip pocket. Accordingly, the natural frequency is increased by reducing the weight of the head portion while limiting rigidity reduction, thereby restricting chattering.

Boring tool

The present invention relates to a cutting tool, especially the cutting tool having a head segment releasably attached to a shank segment. According to one aspect of this invention there is provided a cutting tool comprising: (i) a head segment rotatable around an axis thereof and a forward end portion having at least one cutting-insert receiving seat and a rearward end portion; (ii) a shank segment rotatable around an axis thereof having a forward end portion adapted to be coaxially joined with the rearward end of the head segment and a rearward end portion adapted to be fixedly secured to a machine spindle; (iii) an engaging hole coaxially formed on one of the above segments, which is provided with at least two internal threads communicating between the hole and the external surroundings through a peripheral surface of the segment; (iv) an engaging projection coaxially formed on other one of the segments and engagingly fitted into the hole; and (v) clamp screws respectively threaded through each internal thread, in which bottom ends of the clamp screws are contacted with a surface of the engaging projection.

Cutting tool

A throw-away cutting tool is disclosed. The tool body of the cutting tool consists of a rod-like shank and a bit mounting component arranged at the front end of the shank. The shank is made of cemented carbide, and is formed with a mounting wall extending toward the front end of the tool body. The bit mounting component is made of steel or sintered metal, and is formed with a bit mounting seat defined by a bottom wall and side walls. In the above cutting tool, high resistance against the cutting force produced by cutting operation can be obtained and separation of the shank and the bit mounting component can be prevented; and high rigidity of the tool body is ensured, the damping capacity of the tool body is increased, and therefore vibration and chatter of the cutting tool can be effectively prevented.

Throw-away cutting tool

There is disclosed a ball end mill which has a hemishepherical portion formed at a front end of an end mill body. A pair of tip mounting seats are formed at the hemishepherical portion. A main throw-away tip and a second throw-away tip are secured on the tip mounting seat respectively such that the axial rake angle of the main tip is set at a negative angle and the axial rake angle of the second tip is set at a positive angle. There is also disclosed a second ball end mill. In the second ball end mill, only a main throw-away tip is secured on a tip mounting seat. The axial rake angle of the main tip is set at a negative angle. One or more chip breaker grooves are formed on a rake face of the tip.

Ball end mill

A boring bar tool for use with a tip is disclosed which has a tool body. The tip is mounted to one side of a forward end of the nose of the tool body. A neck is formed at a proximal end of the nose, and a shank in the form of a shaft is formed at a proximal end of the neck. The neck has a cross-sectional area in a plane perpendicular to an axis of the shank which is larger than the cross-sectional area of the shank in the plane.

Boring bar tool

A ball end mill is disclosed which has an end mill body, an indexable cutting insert, a clamp screw and an engaging portion. The end mill body includes an axis of rotation therethrough and an insert receiving recess formed in a forward end portion thereof. The insert receiving recess has a concavely curved bearing wall. The insert is generally of an elliptical shape having a pair of convexly curved side faces, and is received in the recess with one of the side faces being held in engagement with the bearing wall. The clamp screw releasably secures the cutting insert to the insert receiving recess. The engaging portion is provided on the end mill body so as to be adjacent to the insert receiving recess, and is adapted to be held in engagement with the other side face of the insert.

A rotary cutting tool is disclosed which has a tool body, a cutting insert, a clamp member and a clamp screw. The tool body has an insert-receiving recess and a clamp member-receiving aperture formed in an outer surface thereof. The insert-receiving recess has a bottom and at least two bearing walls disposed so as to be inclined with respect to each other. The clamp member-receiving aperture is disposed so as to be communicated with the recess. The cutting insert includes a plate having a front face serving as a rake surface and a rear face. The cutting insert is releasably received in the recess with the rear face being mated with the bottom, in such a manner that the front face is partly located in the clamp member-receiving aperture. The clamp member has an axis therethrough and an engagement portion. The clamp member is releasably accommodated in the clamp member-receiving aperture so as to be axially slidable, with the engagement portion being held in abutment with the front face of the cutting insert. The clamp screw is threaded into the tool body so as to be held in abutting engagement with the clamp member, to thereby press the clamp member against the insert. The clamp screw is preferably arranged such that an angle defined between the axis of the clamp member and the front face of the insert ranges from 30 degrees to 60 degrees. The clamp member is preferably arranged such that as viewed from the rake surface, the clamp member extends in a direction toward the at least two bearing walls.

Rotary cutting tool

A cutter insert for a ball end mill is disclosed which includes a plate-like insert body having a front face and a side face extending from the front face. The front face has a generally convexly curved marginal ridge defined by the intersection of the front face with the side face. The marginal ridge serves as a cutting edge. The front face serves as a rake surface for the cutting edge while the side face serves as a relief surface for the cutting edge. The cutting edge has a leading portion to be indexed in the end cutting position and a trailing portion to be indexed in the peripheral cutting position. A land is formed on the rake surface so as to extend along the cutting edge. The land has a width gradually increasing in a direction from the leading portion of the cutting edge toward the trailing portion thereof.

Cutting insert for ball end mill

A cutting tool having a positioning block inserted between the cutting insert and the insert-receiving seat is disclosed. The disclosed cutting tool demonstrates excellent resistance to damage by severe vibration caused by the milling process. The cutting tool of the present invention comprises (a) a tool body having a recess formed at a forward end thereof and defining a insert-receiving seat; (b) a cutting insert; (c) a positioning block to be placed between the cutting insert and said insert-receiving seat, having a top and bottom faces and having a hardness thereof which is lower than that of a surface of an insert-receiving seat; and (d) clamp means for securing the cutting insert and the positioning block on the insert-receiving seat. The above described positioning block is able to absorb some extent of vibration of the cutting insert during the milling process. According to the present invention, there is also provided the cutting tool in which a positioning block has two layers. A hardness of a surface of the insert-receiving seat is higher than that of the first layer but is lower than that of the second layer.

A rotary cutter is disclosed which includes a cutter body having an axis of rotation therethrough and a cutting insert releasably secured to a forward end of the cutter body. The cutting insert has marginal ridges defining a main cutting edge and an auxilliary cutting edge. The main cutting edge is directed radially outwardly of the cutter body while the auxiliary cutting edge is directed axially forwardly of the cutter body. The cutting insert has faces defining a first rake surface and a second rake surface. The first rake surface is disposed adjacent to the main and auxiliary cutting edges such that an axial rake angle is no less than +30.degree.. The second rake surface is disposed between the first rake surface and the auxiliary cutting edge such that an angle, defined between the second rake surface and the axis of rotation of the body as viewed in a cross-section perpendicular to the auxiliary cutting edge, is no larger than .degree.20.degree.. The second rake surface is formed such that a distance, measured in a direction parallel to the first rake surface and defined between the auxiliary cutting edge and the intersection of the first rake surface with the second rake surface, is set so as to range from 0.5 mm to 1.5 mm.

Rotary cutter

A ball end mill is disclosed which includes a tool body having an axis of rotation therethrough and having a forward end portion, and a cutting edge provided on the forward end portion of the tool body and having an arcuate shape as viewed in a direction opposite to the direction of rotation of the tool body. The cutting edge is comprised of a radially inner portion disposed adjacent to the axis of rotation of the tool body and extending radially inwardly of the tool body in a direction opposite to the direction of rotation of the tool body, and a radially outer portion extending from the inner portion radially outwardly and axially rearwardly of the tool body. Each of the inner and outer portions of the cutting edge is formed of a two-layered composite sintered complex having a base layer of cemented carbide and an upper layer of sintered super hardened compact disposed on the base layer and containing cubic boron nitride, diamond or the like. The composite sintered complex defining the outer portion of the cutting edge is arranged such that the upper layer is directed in the direction of rotation of the tool body while the composite sintered complex defining the inner portion of the cutting edge is arranged such that the upper layer is directed forwardly of the tool body.

An end mill is disclosed which includes a tool body having a shaft-like shape. The tool body has a cutting edge portion formed at one end thereof. The cutting edge portion has a plurality of circumferential cutting edges formed on the circumference thereof along the longitudinal axis of the tool body. The end mill is characterized in that the cutting edge portion has the circumferential surface thereof which includes rake faces and flanks. Each of the rake faces adjoins one of two adjacent circumferential cutting edges. Each of the flanks intersects with one of the rake faces at one end and adjoins the other of the two adjacent circumferential cutting edges at the other end. The rake faces have a rake angle arranged between a range of 5.degree. to -45.degree. at a cross section perpendicular to the axis of the tool body. The flanks have a relief angle arranged between a range of 20.degree. to 45.degree. at a cross section perpendicular to the axis of the tool body. In one embodiment, the circumferential surface of the cutting edge portion is formed of an alternately connected plurality of concave surfaces receding inwardly toward the center of the cutting edge portion, with different ranges of rake and relief angles.

End mill

An inserted tooth rotary cutter is disclosed which includes a tool body having an axis of rotation therethrough and a plurality of indexable cutting inserts. The tool body is defined by forward and rearward axial faces and a circumferential surface lying between the forward and rearward axial faces. The tool body has a plurality of insert receiving recesses formed in the circumferential surface in circumferentially spaced relation to one another and has a mounting bore formed coaxially therewith. Furthermore, the tool body has a plurality of through holes formed in circumferentially spaced relation to one another. Each through hole is disposed between two adjacent insert receiving recesses and opens to the circumferential surface and the forward axial face. Each insert is releasably secured to a respective insert receiving recess.

Growing community of inventors

Tokyo, Japan

Masayuki Okawa