Abstract: A suspension coil spring includes a lower end turn portion, an upper end turn portion, and a helical effective portion formed between the end turn portions. The lower end turn portion includes a first portion which contacts a lower spring seat irrespective of a load, and a second portion which contacts the lower spring seat or is separated from the same according to the load. The wire diameter of the second portion is greater than that of the first portion and an average wire diameter of the effective portion. The upper end turn portion includes a third portion which contacts an upper spring seat, and a fourth portion. The wire diameter of the fourth portion is greater that of the third portion and the average wire diameter of the effective portion.

Abstract: A strut-type suspension includes a compression coil spring, a lower spring seat, an upper spring seat, and a shock absorber. The compression coil spring is disposed at a position offset to the outer side of a vehicle with respect to the shock absorber. The compression coil spring is mounted in a vehicle body in such a state that it is compressed between spring seats. The compression coil spring includes a large-diameter wire portion and a small-diameter wire portion. The large-diameter wire portion is provided in a vehicle inner-side portion of the compression coil spring. The small-diameter wire portion is provided in a vehicle outer-side portion. A wire diameter of the large-diameter wire portion is greater than a wire diameter of the small-diameter wire portion.

Abstract: A knee-action-type suspension is provided with an arm member, a compression coil spring, and a shock absorber. The coil spring is extended and retracted between a full-rebound state and a full-bump state in accordance with the magnitude of a load applied to a vehicle body. A wire of the coil spring includes a large-diameter wire portion, a small-diameter wire portion, and a wire diameter varying portion. The large-diameter wire portion is provided in a first portion of the coil spring, which is on the side near to a pivot. The small-diameter wire portion is provided in a second portion of the coil spring, which is on the side far from the pivot. A wire diameter of the large-diameter wire portion is greater than a wire diameter of the small-diameter wire portion.

Abstract: A suspension coil spring includes a lower end turn portion, an upper end turn portion, and a helical effective portion formed between the end turn portions. The lower end turn portion includes a first portion which contacts a lower spring seat irrespective of a load, and a second portion which contacts the lower spring seat or is separated from the same according to the load. The wire diameter of the second portion is greater than that of the first portion and an average wire diameter of the effective portion. The upper end turn portion includes a third portion which contacts an upper spring seat, and a fourth portion. The wire diameter of the fourth portion is greater that of the third portion and the average wire diameter of the effective portion.

Abstract: A strut-type suspension includes a compression coil spring, a lower spring seat, an upper spring seat, and a shock absorber. The compression coil spring is disposed at a position offset to the outer side of a vehicle with respect to the shock absorber. The compression coil spring is mounted in a vehicle body in such a state that it is compressed between spring seats. The compression coil spring includes a large-diameter wire portion and a small-diameter wire portion. The large-diameter wire portion is provided in a vehicle inner-side portion of the compression coil spring. The small-diameter wire portion is provided in a vehicle outer-side portion. A wire diameter of the large-diameter wire portion is greater than a wire diameter of the small-diameter wire portion.

Abstract: A knee-action-type suspension is provided with an arm member, a compression coil spring, and a shock absorber. The coil spring is extended and retracted between a full-rebound state and a full-bump state in accordance with the magnitude of a load applied to a vehicle body. A wire of the coil spring includes a large-diameter wire portion, a small-diameter wire portion, and a wire diameter varying portion. The large-diameter wire portion is provided in a first portion of the coil spring, which is on the side near to a pivot. The small-diameter wire portion is provided in a second portion of the coil spring, which is on the side far from the pivot. A wire diameter of the large-diameter wire portion is greater than a wire diameter of the small-diameter wire portion.

Abstract: A Co—Cr—Mo alloy fine wire has superior biocompatibility, corrosion resistance, wear resistance, processability, and flexibility. A manufacturing method and a planar body or the like formed by processing this fine wire. This is a fine wire of diameter of 200 micrometers or less comprising 26 to 31 weight % of Cr, 8 to 16 weight % of Mo, and the remainder of Co and inevitable impurities, in which the degree of roundness (minor diameter/major diameter) of lateral cross section is 0.6 or more, and the internal structure is uniform with the concentration ratio of high Mo concentration phase to low Mo concentration phase of 1.8 or less.

Abstract: A golf shaft includes: a hollow tubular structure; and a gradient structure in which an amount of retained austenite is increased from an approximate center in a thickness direction of the hollow tubular structure to a surface of the hollow tubular structure.

Abstract: The present invention provides a leaf spring material superior in mechanical characteristics and a manufacturing method of the leaf spring material capable of reliably achieving the same, utilizing induction hardening. The manufacturing method of the leaf spring material comprises the steps of imparting tensile stress on a first surface along the longitudinal direction of the first surface and compressive stress on a second surface along the longitudinal direction of the second surface of a substantially strip-shaped steel plate, and subjecting the first surface to induction hardening. With this induction hardening, an induction-hardened structure having a higher average hardness than that of a parent material structure in the vicinity of the second surface and comprising martensite and finely and evenly dispersed austenite is imparted on a surface layer in the vicinity of the first surface.

Abstract: The present invention provides a leaf spring material superior in mechanical characteristics and a manufacturing method of the leaf spring material capable of reliably achieving the same, utilizing induction hardening. The leaf spring material comprises a substantially strip-shaped steel plate having a first surface and a second surface. The leaf spring material has in the vicinity of the first surface a hardened layer comprising an induction-hardened structure having a higher average hardness than that of the parent material structure in the vicinity of the second surface, and a compressive residual stress layer of a thickness at least not smaller than that of the thickness of the hardened layer in the vicinity of the first surface. Such a characteristic structure is achieved by stress-induced hardening that imparts a predetermined tensile stress or higher.

Abstract: A golf shaft includes: a hollow tubular structure; and a gradient structure in which an amount of retained austenite is increased from an approximate center in a thickness direction of the hollow tubular structure to a surface of the hollow tubular structure.

Abstract: A Co—Cr—Mo alloy fine wire has superior biocompatibility, corrosion resistance, wear resistance, processability, and flexibility. A manufacturing method and a planar body or the like formed by processing this fine wire. This is a fine wire of diameter of 200 micrometers or less comprising 26 to 31 weight % of Cr, 8 to 16 weight % of Mo, and the remainder of Co and inevitable impurities, in which the degree of roundness (minor diameter/major diameter) of lateral cross section is 0.6 or more, and the internal structure is uniform with the concentration ratio of high Mo concentration phase to low Mo concentration phase of 1.8 or less.

Abstract: A precipitation hardened Co—Ni based heat-resistant alloy is composed of, all by weight, not more than 0.05% of C; not more than 0.5% of Si; not more than 1.0% of Mn; 25 to 45% of Ni; 13 to 22% of Cr; 10 to 18% of Mo or 10 to 18% of Mo+½W; 0.1 to 5.0% of Nb; 0.1 to 5.0% of Fe; and further at least one kind of 0.007 to 0.10% of REM; 0.001 to 0.010% of B; 0.0007 to 0.010% of Mg and 0.001 to 0.20% of Zr; the balance of substantially Co and inevitable impurities, and Co3Mo or Co7Mo6 is precipitated in boundaries between a fine twin structure and a parent phase.

Abstract: By controlling the thickness of the nitrization layer formed on the surface, the coil spring made of spring steel may be made highly resistant to permanent set and fatigue. By carbonitriding the material of the coil spring to a depth of 20 to 50 .mu.m from the surface thereof so as to have an internal hardness of Hv 540 or higher, the coil spring can be made to endure 10.sup.7 cycles of repeated high stress without suffering any significant permanent set.

Abstract: A joint of Ti--Al intermetallic compounds, comprising a plurality of base members made of a Ti--Al intermetallic compound and having Ti--Al lamellar grains, and a junction provided between the base members, made of a Ti--Al intermetallic compound and having Ti--Al lamellar grains, wherein some of the lamellar grains of the junction extend into the base members, and some of the lamellar grains of each base member may extend into the junction or pass through the junction into the other base member.

Abstract: An article essentially consisting of one or more of Ti-Al intermetallic compounds is fabricated so as to have a volume ratio of voids of 0.2 to 3.5% and a maximum size of voids less than 50 .mu.m, by preparing a mixture of materials selected from a group consisting of Ti, Ti alloys, Al, Al alloys, and Ti-Al compounds, having a composition suitable for forming a desired Ti-Al intermetallic compound, and heating the mixture so that the mixture may be sintered. Typically, the temperature and pressure for the heating or sintering process, and the particle size of the material are appropriately selected so that a desired porosity and a desired range of void sizes may be obtained. The mechanical strength of the article according to the present invention is not only improved (as compared to the conventional Ti-Al intermetallic compounds) but is highly predictable, or, in other words, highly reliable.

Abstract: An article essentially consisting of one or more of Ti--Al intermetallic compounds is fabricated so as to have a volume ratio of voids no more than 3.5%, by preparing a mixture of materials selected from a group consisting of Ti, Ti alloys, Al, Al alloys, and Ti--Al compounds, having a composition suitable for forming a desired Ti--Al intermetallic compound, and heating said mixture so that said mixture may be sintered. Typically, the temperature and pressure for the heating or sintering process is appropriately selected so that the desired porosity may be obtained. The mechanical strength of an article according to the present invention is not only improved but is highly predictable, or, in other word, highly reliable. The fabrication costs can be reduced because the fabrication process involves only relatively low temperatures when pressing and heating the work at the same time.

Abstract: An article essentially consisting of one or more of Ti-Al intermetallic compounds is fabricated so as to have a volume ratio of voids no more than 3.5%, by preparing a mixture of materials selected from a group consisting of Ti, Ti alloys, Al, Al alloys, and Ti-Al compounds, having a composition suitable for forming a desired Ti-Al intermetallic compound, and heating said mixture so that said mixture may be sintered. Typically, the temperature and pressure for the heating or sintering process is appropriately selected so that the desired porosity may be obtained. The mechanical strength of an article according to the present invention is not only improved but is highly predictable, or, in other word, highly reliable. The fabrication costs can be reduced because the fabrication process involves only relatively low temperatures when pressing and heating the work at the same time.