Mazda Motor Corporation

Katsunori Hanakawa

Kyoso Ishida

Mitsugi Fukahori

Yukio Yamamoto

Yukihiro Sugimoto

Yoshihisa Miwa

Motoyasu Asakawa

Ken Okazaki

Yasuo Uosaki

Takayuki Sunakawa

Kyousou Ishida

A pair of left and right front frames are formed with brittle sections on proximal portions of the frames, by the provision of the smaller cross-sectional area than other sections of the frame. The brittle sections and their peripheral sections are processed so as to become approximately equal to the other sections of the front frames in axial compressive strength by way of a hardening treatment like quenching. In an early-phase of a collision, the hardened brittle sections will not buckle so as to induce larger initial load. Thereafter, the brittle sections will buckle because of their lower ductility, so that the front frames begin bending deformation to effectively absorb the collision energy.

Body frame structure for a vehicle and method for manufacturing thereof

A method for producing a formed member made of a steel sheet according to the present invention is characterized by preparing a steel sheet material having tensile strength of 500 MPa or less and containing a nitriding element; forming a formed member having a predetermined shape by performing a plastic forming on the steel sheet material; and performing a nitriding treatment on the formed member so that an average hardness in the sheet thickness direction of the resultant steel sheet member is Hv 300 or more by Vickers hardness, and further characterized in that the difference in hardness between the surface part and the inside center part in the thickness direction of the steel sheet member of the formed member is Hv 200 or less by Vickers hardness, thereby it is possible to reliably obtain a formed member having a sufficiently high strength after a nitriding treatment while ensuring a plastic formability of a steel sheet in obtaining a formed member made of a steel sheet member of high strength by performing a nitriding treatment after subjecting a steel sheet material to a plastic forming.

Formed member made of steel sheet and method for producing same

An automobile bodyshell frame structure includes a generally elongated first panel member, and a generally elongated second panel member having opposite side edge portions connected to the first panel member to define a hollow between the first and second panel members. A filler is disposed within a portion of a cross-section of the hollow between the first and second panel members. This filler is provided on an inner surface of one of the first and second panel members and has an average compressive strength equal to or greater than 4 Pa and/or a maximum bending strength equal to or greater than 10 MPa.

Automobile bodyshell frame structure

Material characteristics that a foamed filler material (s) to be filled in a frame cross section (fr) should have are discussed. By using a material complying with the characteristics, the energy absorbability of the frame (fr) is effectively enhanced. In a frame structure (fr) for vehicle bodies in which a filler material is filled in at least part of the cross section of a frame, the filler material is set to a mean compressive strength of not less than 4 MPa and/or a maximum bending strength of not less than 10 MPa. More particularly, the filler material is set to a mean compressive strength of not less than 5 MPa and/or a maximum bending strength of 60 MPa.

Frame structure for vehicle body

In an apparatus accommodating a rotor of light alloy and a rotor shaft of steel secured to each other, the rotor shaft consists of a first shaft and a pair of second shafts integrally formed with or rigidly secured to the first shaft. The first shaft has a structure with a thermal coefficient of expansion close to that of the rotor whereas each of the second shafts has a structure with a thermal coefficient of expansion less than that of the first shaft.

Structure of a rotor shaft and method of making same

An apex seal consisting of 3.0 to 4.0 wt % of C, 1.5 to 2.5 wt % of Si, 0.3 to 1.0 wt % Mn, 0.05 to 0.3 wt % of P, less than 0.1 wt % of S, 0.005 to 0.025 wt % of Mg or Ce, 0.5 to 2.0 wt % of Cu and/or 0.5 to 3.0 wt % of Ni, 0.4 to 1.0 wt % of Cr, 1.0 to 2.0 wt % of Mo and/or 0.1 to 0.5 wt % of V with the balance of Fe, being formed in the sliding surface portion with a sorbite matrix structure in which carbides are dispersed in a matrix of sorbite and in the matrix portion of the material other than the sliding surface portion with a sorbite structure. The apex seal has an excellent bending strength and wear resistance.

Growing community of inventors

Hiroshima, Japan

Katsunori Hanakawa