Osg Corporation

Tasuku Itoh

Jiro Osawa

Takayuki Matsushita

Yasuo Hamatake

Takuma Aoyama

Katsutoshi Watanabe

Kentarou Norimatsu

Kentaro Norimatsu

Shigetoshi Ukei

Hiroshi Tomita

Ikuo Takikawa

An indexable thread forming tap including: a body in a shaft shape; and a tip concentrically and detachably attached to a leading end portion of the body by screw-fastening and rotationally driven around an axial center along with the body for rolling of a female thread, the body being disposed with a screw hole concentrically to the axial center such that a screw shaft disposed on the tip concentrically to the axial center is screwed into the screw hole for the screw-fastening, a leading end surface of the screw shaft being pressed against a bottom surface of the screw hole into close contact with each other by the screw-fastening to integrally fix the tip to the body without the leading end of the body abutting on the tip, the body being disposed with a restraining hole concentrically to the axial center.

Indexable thread forming tap

A variable lead end mill has a plurality of peripheral cutting edges with different helix angles, the variable lead end mill having a flute bottom diameter of a plurality of helix flutes making up rake faces of the plurality of the peripheral cutting edges, the flute bottom diameter increasing in an axial direction from a tool tip toward a shank.

Variable lead end mill

A removable tip type rotary tool is provided in which a rotation stop key and a key groove each having a triangular shape are disposed on opposing surfaces of a body and a tip concentrically attached to a leading end portion of the body in a removable manner. A pair of side surfaces of the rotation stop key and a pair of side walls of the key groove are brought into surface contact by mounting screw. An angle for each of the pair of the side surfaces and the pair of side walls is between 60 to 100 degrees, a groove bottom of the key groove is rounded with a radius from 1.5 to 2.8 mm, corners of opening edges on both sides of the key groove and corners of both base-end side portions of the rotation stop key are rounded with radiuses, respectively, from 1.5 to 2.8 mm.

Removable tip type rotary tool

A machining head replaceable rotating tool having a fastening male screw and a fastening female screw disposed on respective shaft centers of one and the other of a machining head and a holder, the fastening male and female screws being threadably engaged with each other to concentrically and removably attach the machining head to a tip portion of the holder, the machining head and the holder being disposed with abutting surfaces abutted against each other in a fastened state when the fastening male and female screws are threadably engaged, the machining head replaceable rotating tool being integrally and rotationally driven via the holder in a tool rotation direction causing the fastening male and female screws to be fastened by a machining load to perform predetermined machining with the machining head, the abutment of the abutting surfaces preventing the fastening male and female screws from being further fastened by a machining load, the fastening male and female screws being saw-tooth buttress screws having a following flank angle &#x3b1; smaller than a leading flank angle &#x3b2;.

Machining head replaceable rotating tool, holder, and machining head

A throw-away rotating tool includes plural protrusions formed in a part of an outer peripheral wall of a projecting coupling portion. Since the twist angle and a twist direction of the protrusions are set in such a way that with relative rotation when coupling the projecting coupling portion and erected portions together, due to the reaction force received by the protrusions from inner peripheral walls, the projecting coupling portion is pulled to the rear and side of the erected portions and the projecting coupling portion is stably held between the erected portions. Since the number of portions that require stringent dimension control and high machining accuracy can be reduced, productivity can be improved.

Throw-away rotating tool

A bevel head replaceable rotary tool is provided. The rotary tool includes a coupling protrusion and a coupling recess, plural sets of serrations provided on an outer circumferential surface of the coupling protrusion and an inner wall surface of the coupling recess, circumferential abutting portions provided on the tool body and the bevel head, and axial tight-contact portions, provided on the tool body and the bevel head. The serrations of the coupling protrusion and the serrations of the coupling recess arranged such that curvatures of circumferential circular arcs of the serrations of the coupling protrusion are greater than those of the serrations of the coupling recess or the serrations of the coupling protrusion and the serrations of the coupling recess have circumferential circular arcs with centers deviated from each other.

Bevel head replaceable rotary tool, bevel head and tool body

In a semi-finishing cutter, rectangular tips and square tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a single cutting edge is formed by a pair of one of the rectangular tips and one of the square tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. A cutting speed of the semi-finishing cutter may be increased and a cutting feed may be made faster, so work in a semi-finishing process may be performed efficiently. The rectangular tips and the square tips have simple shapes, so known commercially available throwaway tips may be used. Accordingly, it is possible to provide the semi-finishing cutter in an easy-to-use form without increasing the cost.

Throwaway rotary cutting tool

In a rough cutting cutter, square tips and rectangular tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a cutting edge is formed by a pair of one of the square tips and one of the rectangular tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. Furthermore, in the second to a fifth step portions, ARs (rake angles in the axial direction) and RRs (rake angles in a radial direction) of the square tips and the rectangular tips gradually increase in order from a tip end to a back end of a tool body. It is therefore possible to suppress chatter vibration during machining and is possible to reduce roughness of a cut surface of a work material.

A throw-away rotating tool improves workability of detaching a throw-away tip and prevents from damaging a body. In the throw-away tool, a convex connection for the throw-away tip has protrusions, each of the protrusion includes a sliding contact portion detachably fitted into the inner peripheral groove recessed in the inner peripheral wall of a body. The protrusion has a first tilt portion continuous to the sliding contact portion. In detaching the throw-away tip from the body, the first tilt portion rotates ahead of the sliding contact portion, and a standing portion is elastically deformed due to a wedge effect of the first tilt portion. As a result, the protrusion can be gently removed from the inner peripheral groove.

In cutting processes of a tree-shaped groove, in a rough cutting process, by using a rough cutting tool (), as well as cutting a tapered groove (), cutting is performed in a first narrow portion (), a second narrow portion (), and a third narrow portion () of a planned groove shapesuch that a specified cutting allowance is left. In the following semi-finishing process, by using a semi-finishing tool, cutting is performed for portions other than the three narrow portions (to) that have already been cut. Because a work materialdoes not come in contact with three reduced diameter portions, of the semi-finishing tool formed in an upside-down Christmas tree shape, corresponding to the three narrow portions (to), a load is not imposed on the three reduced diameter portions, which are weak against shock among all portions of the semi-finishing tool, and the cutting feed can therefore be faster. Further, by performing a finishing process, the tree-shaped groove can be efficiently cut.

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Toyokawa, Japan

Tasuku Itoh