Kouichi Kuroda

Bio: Kouichi Kuroda is an academic researcher from Sumitomo Metal Industries. The author has contributed to research in topics: Tube (container) & Die (manufacturing). The author has an hindex of 8, co-authored 48 publications receiving 255 citations. Previous affiliations of Kouichi Kuroda include Sumitomo Heavy Industries & Nippon Steel.

Tube rolling method and apparatus

Abstract: According to the rolling method and the apparatus to be used for its execution of the invention, by rolling a tube to be rolled by using four rolls possessing roll grooves for forming a caliber in a shape of having a relief portion, cold reducing or cold stretch reducing is done continuously without causing wall thickness deviation, and by sizing the rolled tube material by a die disposed at the exit side, the dimensional precision and yield of rolled tubes may be enhanced by a small number of stands.

Effect of final drawing with light reduction on the levelling of residual stress distribution in cold bar drawing

Abstract: A method is proposed for producing a significant reduction in the magnitude of the residual stress generated after cold drawing of a bar. It consists basically of a skin pass at the final s...

Process for making a work piece from a beta-type titanium alloy material

Abstract: A process for making a work piece from a β-type titanium alloy material includes subjecting the β-type titanium alloy material to cold working with controlling the reduction rate thereof to vary the reduction rate depending on a position across a plain direction of the β-type titanium alloy material, and then subjecting the β-type titanium alloy material to an aging treatment.

Seamless steel tube for drive shaft and method of manufacturing the same

Abstract: A method of manufacturing a seamless steel tube for a drive shaft and a method of manufacturing the seamless steel tube, wherein a hollow member for the drive shaft having excellent fatigue strength and suitable for reducing the weight of a vehicle body can be manufactured by applying a facilitated inner surface cutting and the subsequent cold reduction to a steel tube hot-drawn by a Mannesmann tube manufacturing method to specify the recessed part depth (d), surface roughness (Ra), and recessed part inlet width (w) of recessed and protruded parts forming the inner surface of the steel tube or, in the same manner, to specify the recessed part depth (d), Vickers hardness (Hv) of the inner surface layer, and recessed part inlet width (w) of the recessed and protruded parts. Since the drive shaft for car can be efficiently manufactured at low production cost, the effect thereof can be industrially increased.

Effect of die geometry on residual stress level present after bar drawing

Abstract: A new drawing die designed to reduce the residual stresses in bar after drawing is presented. The die design consists of two consecutive straight taper portions, and the outlet portion has a very small die angle. The marked beneficial effect of adding the outlet portion was predicted by finite element modelling (FEM), and subsequently verified by measuring the residual stresses in drawn bars. The optimum range of the outlet die angle was determined using FEM. The new design requires a slightly longer die length than the conventional one, but it is short enough to be adopted in current production lines.

Closed-loop control of product properties in metal forming

Abstract: Metal forming processes operate in conditions of uncertainty due to parameter variation and imperfect understanding. This uncertainty leads to a degradation of product properties from customer specifications, which can be reduced by the use of closed-loop control. A framework of analysis is presented for understanding closed-loop control in metal forming, allowing an assessment of current and future developments in actuators, sensors and models. This leads to a survey of current and emerging applications across a broad spectrum of metal forming processes, and a discussion of likely developments.

Metal wood club with improved hitting face

Abstract: A hitting face of a golf club head having improved flexural stiffness properties. In one embodiment, the hitting face is made from multiple materials. The main portion of the hitting face is a plate-like face made from a first material having a first density. A dense insert made from a second material having a second density that is greater than the first density is attached directly or indirectly to the plate-like face at or near the geometric center thereof. The dense insert increases the flexural stiffness of in a central zone of the hitting face so that a golf club head that has a larger zone of substantially uniform high initial ball speed. In another embodiment, the hitting face includes an insert that includes main plate and at least one wing extending therefrom. The insert is welded to the golf club head so that the main plate does not deflect separately from the remainder of the hitting face. The geometry of the insert controls the stiffness in the axial directions.

Processing of titanium-aluminum-vanadium alloys and products made thereby

Abstract: A method of forming an article from an α−β titanium including, in weight percentages, from about 2.9 to about 5.0 aluminum, from about 2.0 to about 3.0 vanadium, from about 0.4 to about 2.0 iron, from about 0.2 to about 0.3 oxygen, from about 0.005 to about 0.3 carbon, from about 0.001 to about 0.02 nitrogen, and less than about 0.5 of other elements. The method comprises cold working the α−β titanium alloy.

Rotation transmission device

Abstract: A rotation transmission device having a high torque measurement resolution is provided. The rotation transmission device is provided with: a rotary-shaft unit (6) having a first and second rotary shaft (13, 14) combined so as to be coaxial and such that the end sections thereof can rotate relative to each other and a torsion bar (15) that is provided on the inner-diameter side of the first and second rotary shafts so as to be coaxial therewith, has one end section connected to the first rotary shaft (13), and has the other end section connected to the second rotary shaft (14); a first gear (7) fastened to the outer peripheral surface of the first rotary shaft (13); a second gear (8) fastened to the outer peripheral surface of the second rotary shaft (14); a coupling shaft (9) provided on the inner-diameter side of the torsion bar (15) so as to be coaxial therewith, having one end section connected to one rotary shaft (13), and having the other end section protruding from an end of the torsion bar (15) in the axial direction; a first encoder disposed and fixed on the other end of the coupling shaft (9) so as to be coaxial with the first rotary shaft (13) and having a first detected section (39); a second encoder fastened on the other end of the second rotary shaft (14) so as to be close to the first encoder and having a second detected section (40); and a sensor unit having at least one sensor (42a, 42b) that faces the first and second detected sections (39, 40).

Internal positivity preserved model reduction

Abstract: This article studies model reduction of continuous-time stable positive linear systems under the Hankel norm, H ∞ norm and H 2 norm performance. The reduced-order systems preserve the stability as well as the positivity of the original systems. This is achieved by developing new necessary and sufficient conditions of the model reduction performances in which the Lyapunov matrices are decoupled with the system matrices. In this way, the positivity constraints in the reduced-order model can be imposed in a natural way. As the model reduction performances are expressed in linear matrix inequalities with equality constraints, the desired reduced-order positive models can be obtained by using the cone complementarity linearisation iterative algorithm. A numerical example is presented to illustrate the effectiveness of the given methods.