Abstract: A vehicle knuckle 1 includes a main body 10, a strut junction 11 that is positioned at a first side in an extending direction of an axle supported by the main body and fastens a strut damper, and an arm 12 that couples the main body to the strut junction. The vehicle knuckle has a continuous space 17 formed inside the strut junction and the arm. The arm has a first through-hole 17a on a wall 12a that couples an end 10d at the first side of the main body to the strut junction. The first through-hole is formed, with being adjacent to the end at the first side, at the side of the main body with respect to the center of a coupling position of the wall and the main body and a coupling position of the wall and the strut junction and is communicated with the space.

Abstract: A vehicle knuckle 1 includes a main body 10, a strut junction 11 that is positioned at a first side in an extending direction of an axle supported by the main body and fastens a strut damper, and an arm 12 that couples the main body to the strut junction. The vehicle knuckle has a continuous space 17 formed inside the strut junction and the arm. The arm has a first through-hole 17a on a wall 12a that couples an end 10d at the first side of the main body to the strut junction. The first through-hole is formed, with being adjacent to the end at the first side, at the side of the main body with respect to the center of a coupling position of the wall and the main body and a coupling position of the wall and the strut junction and is communicated with the space.

Abstract: To provide a long-life compression ring without an increase in the outer peripheral abrasion near the gap regardless of the ring material or the presence or absence of the outer peripheral hard coating, in an annular compression ring having a pair of gap faces opposed to each other to form a free gap and a nominal diameter d1 equal to an inner diameter of a cylinder to which the compression ring is attached to along with a piston, a self tangential force is 5 N to 50 N, and a radius of curvature R1 and the nominal diameter d1 satisfy a relationship: ?0.01?(2R1?d1)/d1<0.002 where the radius of curvature R1 is that of outer peripheral arcs of gap end portions in a free shape state before the compression ring is attached to the cylinder, and the gap end portions are defined in ranges between the gap faces and positions where a center angle from a midpoint of the free gap is 35°.

Abstract: The present disclosure is a combination of a cylinder and a piston ring, the combination including a cylinder of an internal combustion engine and a piston ring sliding on an inner peripheral surface of the cylinder. The piston ring has an outer peripheral surface sliding on the inner peripheral surface of the cylinder, and the outer peripheral surface is formed of a substantially hydrogen-free amorphous carbon coating. The Vickers hardness Hd of the amorphous carbon coating and the Vickers hardness Hb of the inner peripheral surface of the cylinder satisfy Hd+Hb?2500 HV. The ratio ID/IG of the peak intensity of the D band to the peak intensity of the G band in a Raman spectrum obtained by measuring the amorphous carbon coating by Raman spectroscopy is 0.60 or more and 1.33 or less.

Abstract: To provide a piston ring excellent in thermal setting resistance, and also excellent in side surface wear resistance even under such a high-temperature high-pressure environment as to be more than 300° C. and up to 400° C., the base metal of the piston ring is a steel containing, by mass %, C: 0.30 to 0.65%, Si: 0.80 to 1.20%, Mn: 0.20 to 0.60%, Cr: 4.50 to 5.70%, Cu: 0.01 to 0.5%, and at least one of Mo, V, W, and Co: 0.2 to 5.4%.

Abstract: Provided is a side rail 1 having an outer peripheral surface 14, an inner peripheral surface 13, a first axial side surface 11, and a second axial side surface 12 parallel to the first axial side surface 11, in which, a beveled portion 30 is provided between the outer peripheral surface 14 and the second axial side surface 12, the beveled portion 30 is formed in a tapered surface having a diameter gradually decreasing from the first axial side surface 11 toward the second axial side surface in an axial direction; a tapered surface 30a is provided between a first tapered surface portion 30a1 with an angle of 10° or more to the axial direction and a second tapered surface portion 30a2 provided between the first tapered surface portion 30a1 and the outer peripheral surface 14 and having a smaller angle of inclination to the axial direction than that of the first tapered surface portion.

Abstract: A spheroidal graphite cast iron having a chemical composition of: C: 3.0% to 4.0%, Si: 2.0% to 2.4%, Cu: 0.20% to 0.50%, Mn: 0.15% to 0.35%, S: 0.005% to 0.030%, Mg: 0.03% to 0.06%, each by mass, and the balance being Fe and inevitable impurities, where Mn and Cu are contained at 0.45% to 0.75% in total; and a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite. Part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.

Abstract: A vehicle knuckle (1) includes a main body portion (10) for supporting an axle, a strut connecting portion (11) for connecting a strut, and an arm portion (12) for connecting the main body portion (10) and the strut connecting portion (11) and having a space (18) inside. The arm portion (12) includes a sidewall portion (120) for connecting the main body portion (10) and the strut connecting portion (11), and has a first through hole (17a) communicating with the space (18), at a coupling portion (12a) with the main body portion (10). The sidewall portion (120) is free of a through hole communicating with the space (18).

Abstract: A sliding member having a hard carbon coating that has a thickness of 3 ?m or more and demonstrates high peeling resistance and high wear resistance is provided. A sliding member 100 according to the present disclosure includes a base member 10 and a hard carbon coating 12 that is formed on the base member 10 and has the hydrogen content of 3 atomic % or less and a thickness of 3 ?m or more. When HM represents a Martens hardness of the hard carbon coating 12 and HIT represents an indentation hardness, the ratio HM/HIT is 0.40 or more.

Abstract: [Object] To provide a seal ring capable of both reducing a friction loss and reducing oil leakage. [Solving Means] A seal ring includes: an inner circumferential surface; an outer circumferential surface orthogonal to the inner circumferential surface; side surfaces orthogonal to the inner circumferential surface and the outer circumferential surface; and a plurality of pockets provided, spaced apart from one another in one of the side surfaces. The plurality of pockets each have a symmetrical shape in a circumferential direction and are opened on a side of the inner circumferential surface and closed on a side of the outer circumferential surface.

Abstract: To provide a piston ring excellent in thermal setting resistance, and also excellent in side surface wear resistance even under such a high-temperature high-pressure environment as to be more than 300° C. and up to 400° C., the base metal of the piston ring is a steel containing, by mass %, C: 0.30 to 0.65%, Si: 0.80 to 1.20%, Mn: 0.20 to 0.60%, Cr: 4.50 to 5.70%, Cu: 0.01 to 0.5%, and at least one of Mo, V, W, and Co: 0.2 to 5.4%.

Abstract: A piston includes a piston body and a piston ring fitted into a ring groove. The piston ring has a top surface that includes: a convex portion formed between an inner edge position and a central position at which a radial direction thickness is ½, with the piston ring in a free state, and a planar portion or an inclined peripheral portion continuous with the convex portion on a radially outer side of the convex portion. In a predetermined status of the piston body and the piston ring, an angle between the top surface of the ring groove and the planar portion or the inclined peripheral portion is at least 18 arcminutes in a cross-section that is parallel to a central axis of the piston body and includes the central axis.

Abstract: A sliding member includes a base material, and an amorphous hard carbon film formed on a surface of the base material, in which a sp2 ratio of the amorphous hard carbon film increases from an inner surface side corresponding to the base material side toward an outer surface side thereof to become a maximum value and further decreases toward the outer surface side.

Abstract: A sliding member having a hard carbon coating that has a thickness of 3 ?m or more and demonstrates high peeling resistance and high wear resistance is provided. A sliding member 100 according to the present disclosure includes a base member 10 and a hard carbon coating 12 that is formed on the base member 10 and has the hydrogen content of 3 atomic % or less and a thickness of 3 ?m or more. When HM represents a Martens hardness of the hard carbon coating 12 and HIT represents an indentation hardness, the ratio HM/HIT is 0.40 or more.

Abstract: A sliding member includes a base material and an amorphous hard carbon film formed on a surface of the base material, and the amorphous hard carbon film has a graded structure in which a sp2 ratio increases from an inner surface side corresponding to the base material side toward an outer surface side. A piston ring includes the sliding member.

Abstract: A high rigid spheroidal graphite cast iron, comprising: more than 3.0% to less than 3.6% of C, 1.5 to 3.0% of Si, 1.0% or less of Mn, 1.0% or less of Cu, less than 0.03% of P, 0.02% to 0.07% of Mg, residual Fe and inevitable impurities, as represented by mass %, wherein a carbon equivalent (a CE value) calculated by the mathematical expression (1): CE=C %+Si %/3 in terms of C and Si contents is 3.6 to 4.3%, the Young's modulus is 170 GPa or more, the tensile strength is 550 MPa or more, and the impact value is 12 J/cm2 or more.

Abstract: Provided is a side rail 1 having an outer peripheral surface 14, an inner peripheral surface 13, a first axial side surface 11, and a second axial side surface 12 parallel to the first axial side surface 11, in which, a beveled portion 30 is provided between the outer peripheral surface 14 and the second axial side surface 12, the beveled portion 30 is formed in a tapered surface having a diameter gradually decreasing from the first axial side surface 11 toward the second axial side surface in an axial direction; a tapered surface 30a is provided between a first tapered surface portion 30a1 with an angle of 10° or more to the axial direction and a second tapered surface portion 30a2 provided between the first tapered surface portion 30a1 and the outer peripheral surface 14 and having a smaller angle of inclination to the axial direction than that of the first tapered surface portion.

Abstract: Provided is a sliding member having a hard carbon coating that makes high wear resistance compatible with a low coefficient of friction and that has excellent peeling resistance. A sliding member (100) includes a base member (10) and a hard carbon coating (12) formed on the base member (10). The indentation hardness of the hard carbon coating (12) decreases gradually from the base member side to the surface side. The hard carbon coating (12) has an indentation hardness distribution at 0?T/Ttotal?0.6 approximated by a first line and an indentation hardness distribution at 0.9?T/Ttotal?1 approximated by a second line, and the intersection between the first line and the second line (T2/Ttotal, H2) satisfies Expression (1), (H3?H1)×T2/Ttotal+H1<H2?0.9×H1, and Expression (2), 0.6?T2/Ttotal?0.9.