Ohashi Technica, Inc.

Tk Co., Ltd.

Osamu Kimpara

Akira Nozue

Takuya Saito

Kazuyoshi Harada

Masayuki Mizutani

A method of joining using a supporting electrodehaving a cooling circuit and a pressure electrodemovably arranged above the supporting electrode, using a steel material causing martensitic transformation for one of or both of a first memberhaving an opening portion and a second member, engaging the second member with the opening portion of the first member, starting conduction from a power supply to the supporting electrode and the pressure electrode, allowing an insertion portion of the second member to enter the opening portion of the first member by a pressure force of the pressure electrode, causing the second member and an inner wall portion of the opening portion to be subjected to solid-phase diffusion joining, rapidly cooling the both members by thermal conduction of the supporting electrode after the joining, and quenching a joined portion and generating compressive residual stress by the rapid cooling.

Method of joining part having high fatigue strength

A forced-insertion welded structure is provided which is formed by welding members making up a metal component and which is easy to manufacture and has low cost, a good finish precision and a high bonding strength. The forced-insertion welded structure comprises: a first memberwith a holewhich has the same geometry as a cross section of a forcibly inserted portion of a second member; and the second memberhaving a constant cross section over its length which is similar in shape to the holewherein a press-fit interference of the second memberrelative to the holeof the first memberis set to 0.1 mm or more; wherein the second memberis pushed against the holeof the first memberunder a predetermined pressure and at the same time an electric current is applied between the two members to generate electric resistance heat in faying portions of the two members to forcibly push the second memberinto the holethereby forming a joint interface between the second memberand the inner wall surface of the holewherein the joint thus formed is a solid-state welded joint.

Growing community of inventors

Aichi, Japan

Osamu Kimpara