Toyoda Iron Works Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Nippon Steel Sumitomo Metal Corporation

Sumitomo Metal Industries, Inc.

Masanobu Ichikawa

Masahiro Nakata

Nobuyuki Kawahara

Kazuhito Imai

Akira Obayashi

Shuntaro Sudo

Toshiya Suzuki

Kunihiro Fukui

Tamotsu Toki

Tatsuya Ito

Yukihiro Yoshikawa

Toshinobu Nishibata

Nobuyuki Ichimaru

Tomokichi Tokuda

Kunihiro Sumitomo Metal Industries Ltd Fukui

Yukihiro Sumitomo Metal Industries Ltd Yoshikawa

Kazuhito Sumitomo Metal Industries Ltd Imai

Tamotsu Sumitomo Metal Industries Ltd Toki

A bearing member includes: a large-diameter tubular portion having an external diameter larger than a diameter of a mounting hole formed in a pedal arm and having a cylindrical inner peripheral face; a small-diameter tubular portion formed continuously with the large-diameter tubular portion, having a cylindrical outer peripheral face with a diameter smaller than that of the mounting hole, and having the cylindrical inner peripheral face; and a thin-wall tubular portion formed continuously with the small-diameter tubular portion, having an inner diameter larger than a diameter of the cylindrical inner peripheral face, and having the cylindrical outer peripheral face, and in a condition that the bearing member is inserted into the mounting hole such that the thin-wall tubular portion is protected, and the thin-wall tubular portion is swaged, the mounting hole is held between a swaged portion bulged radially outward and the large-diameter tubular portion.

Bearing member for pedal arm and pedal arm

A bearing member for a pedal arm, which is a tubular bearing member which is disposed so as to connect a first mounting hole and a second mounting hole formed respectively in a pair of plate members constituting right and left side walls of the pedal arm and through which a connecting shaft is passed so as to be rotatable relative to the bearing member, the bearing member includes: a large-diameter tubular portion configured to have an external diameter larger than a diameter of the first mounting hole and to be located between the pair of plate members; a first connecting portion configured to have an external diameter smaller than the diameter of the first mounting hole, to be formed so as to project from one end face of the large-diameter tubular portion coaxially with the large-diameter tubular portion, to be passed through the first mounting hole, and to be fixedly fitted to the first mounting hole by being compressed in an axial direction to be swaged so that a peripheral portion of the first mounting hole is held between a swaged portion, which is formed from the first connecting portion, and the one end face of the large-diameter tubular portion; and a second connecting portion configured to have an external diameter smaller than a diameter of the second mounting hole and a thickness larger than a thickness of the first connecting portion, to be formed so as to project from the other end face of the large-diameter tubular portion coaxially with the large-diameter tubular portion, to be passed through the second mounting hole, and to be fixedly fitted to the second mounting hole by being compressed in the axial direction to be bulged and deformed radially outward so that a portion of the second connecting portion, which is apart from the other end face of the large-diameter tubular portion by a predetermined distance, is brought into close contact with an inner peripheral wall of the second mounting hole.

Bearing member for pedal arm, pedal arm, and method for manufacturing pedal arm

A press-formed product includes a body having a transverse cross section including a bottom portion and a shoulder portion contiguous to the bottom portion through an R end. In the transverse cross section, a first region from the R end to a position a distance away in a bottom portion extending direction, and a second region which is part of the bottom portion and is contiguous to the first region have a work-hardening distribution introduced by press-forming. The work-hardening distribution has an average hardness Hv1 of an area of the first region from a steel sheet surface to a depth obtained by multiplying a steel sheet thickness by 0.2 and an average hardness Hv2 of an area of the second region from the steel sheet surface to a position obtained by multiplying the steel sheet thickness by 0.2 to satisfy a relationship of Hv1&#x3e;1.05&#xd7;Hv2.

Press-formed product

A method of producing a hot press-formed member having good corrosion resistance comprises subjecting a zinc-based plated steel sheet to heat treatment by heating to a temperature region of 600-750&#xb0; C. at a rate of temperature increase up to 600&#xb0; C. of at most 50&#xb0; C. per second followed by cooling to 550&#xb0; C. or below to form a steel blank which has a zinc oxide layer in its uppermost surface portion and below it a zinc-iron alloy phase having an Fe content of at least 25 mass %. This steel blank is heated to a temperature of at least its Acpoint, then press formed immediately at a temperature of at least its Acpoint, and then rapidly cooled. The hot press-formed member has a surface region with zinc oxide and iron-zinc solid solution phases and not containing an intermetallic compound phase or a pure zinc phase.

Method for manufacturing a hot press-formed member

The present invention provides a plate-shaped workpiece positioning structure for hot press forming that, upon executing a hot press forming of a heated plate-shaped workpiece (), positions the plate-shaped workpiece relative to a pair of press dies (). The positioning structure includes (a) a first positioning opening () and (b) a second positioning openings (). The first positioning opening is arranged in a center part of the plate-shaped workpiece, and engages with a first positioning pin () provided on one () of the pair of press dies to position the plate-shaped workpiece. The second positioning openings are arranged between the first positioning opening and a predetermined outer peripheral parts () of the plate-shaped workpiece, and are formed in an elongate shape that extends along a line connecting the first positioning opening and the predetermined outer peripheral part of the plate-shaped workpiece. The second positioning openings engage with a second positioning pins () provided on one () of the pair of press dies. Thus, the plate-shaped workpiece is positioned in a circumferential direction about the first positioning opening of the plate-shaped workpiece. Additionally, the plate-shaped workpiece can contractionally deform toward the first positioning opening upon executing the hot press forming of the heated plate-shaped workpiece.

Plate-shaped workpiece positioning structure for hot press forming

A hot press-formed member having stable strength and toughness is manufactured from a high strength steel sheet by hot press forming. In the cooling stage during hot press forming, the cooling rate is at least the critical cooling rate until the Ms point is reached and it is then in the range of 25-150&#xb0; C./s in the temperature range from the Ms point to 200&#xb0; C. The Vickers hardness of the hot pressed member is less than the value of (maximum quenching hardness&#x2014;10) and at least the value of (maximum quenching hardness&#x2014;100).

Hot forming method and a hot formed member

A hot press-formed article having improved corrosion resistance and coating adhesion when coated is obtained by hot press forming of a zinc-based plated steel material. It has a zinc-based plating layer comprising an iron-zinc solid solution phase and atop it a zinc oxide layer. The average thickness of the zinc oxide layer which is the outermost layer is at most 2 &#x3bc;m. A hot press-formed article having a good appearance and excellent corrosion resistance, coating adhesion, post-coating corrosion resistance, and weldability has a layer () consisting essentially of an iron-zinc solid solution phase atop a base material steel sheet (). It also has a zinc oxide layer () with an average thickness of at most 5 &#x3bc;m as an uppermost layer, but it does not have a substantial amount of an iron-zinc intermetallic compound phase. The total amount of Al contained in the iron-zinc solid solution layer () and the zinc oxide layer () is at most 0.5 g/m, and/or the total amount of Al oxides contained in these layers is at most 5 mg/m.

Hot press-formed article

Growing community of inventors

Nisshin, Japan

Masanobu Ichikawa