The Yasunaga Co., Ltd.

Yasunaga Corporation

Hiroichi Hase

This is a method of forming a fracture start portion of a ductile metal part on an inner circumferential face of a through hole by irradiating laser to an opposing position of the inner circumferential face of the thorough hole of the ductile metal part having a predetermined through hole and by forming a large number of recess portions separated with a predetermined distance at a predetermined interval from one opening to the other opening of the through hole, in which a recess part is formed, instead of by focusing the laser exactly onto the inner circumferential face of the through hole, by irradiating it onto the inner circumferential face of the through hole while defocusing from the inner circumferential face of the through hole by a predetermined amount as well as by supplying an assist gas to a position of the laser irradiation, and the laser is moved linearly at a predetermined speed from one side opening to the other side opening on the inner circumferential face of the through hole while irradiating the laser onto the inner circumferential face of the through hole at a predetermined pulse.

Method of forming fracture start portion of ductile metal part and fracture start portion forming device

A fracture surface treatment method of a fractured ductile metal part for treating fracture surfacesandof the ductile metal part, said fracture surfacesandbeing fracture surfaces obtained by a fracturing operation of fitting halved mandrel portions into a penetrative bore of the ductile metal part having the penetrative bore and driving a wedge in between the halved mandrel portions, said fracture surface treatment method holding said fractured ductile metal partin a state where said fracture surfacesandare separated from each other so as to keep a certain space between them, applying a specified vibration to at least one of said fractured ductile metal part portions in a direction intersecting the direction of fracture and removing fracture powderstuck on said fracture surfacesand, and thereby enabling the optimum face fitting operation in case of fitting again the fracture surfaces of the fractured ductile metal part to each other.

Method and apparatus for removing fracture powder from fracture surfaces of a ductile metal part

A connecting rod fracture machine is disclosed which mateably inserts a half-split type mandrel into an opening of a large end portion of a connecting rod to expand the opening. The machine comprises first and second support members ( ), ( ) for supporting the connecting rod horizontally, the support members being arranged movably apart from each other on the base of a pallet ( ) for placing the connecting rod ( ) thereon. Moreover, the machine includes a half-split type mandrel ( ), vertically provided on these support members, comprising mandrel half portions ( ), ( ) with each outer peripheral surface thereof being in contact with the inner surface of the opening. The machine also comprises a wedge ( ) for separating the mandrel half portions uniformly apart from each other, the wedge having tapered surfaces in contact with opposite edge surfaces of the mandrel half portions.

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Mie, Japan

Hiroichi Hase