A hollow stabilizer production method of a hollow stabilizer used for a vehicle includes attaching a first mounting member and a second mounting member respectively to one end and another end of a formed steel tube and heating the steel tube. The method includes feeding a carburizing gas into the interior space of the heated steel tube through the first mounting member, and collecting the air and/or the surplus carburizing gas from the interior space through the second mounting member to thereby carburize the steel tube inner surface. The method includes rapidly cooling the heated steel tube to thereby quench the steel tube continuously from the carburization.

An annular reference surface is formed around a through-hole of an eye portion. A distal-end-side curved portion is formed at a first corner portion, on an outer side of the annular reference surface. The thickness of the distal-end-side curved portion is reduced in a range of a length from the first flat surface toward the distal end surface. A hole-side curved portion whose thickness is reduced toward an inner surface of the through-hole is formed at a second corner portion, on an inner side of the annular reference surface. The length of the hole-side curved portion is less than the length of the distal-end-side curved portion. The hole-side curved portion is curved with a greater curvature than that of the distal-end-side curved portion.

A hollow stabilizer includes a curved part having eight regions defined in a cross section. A first region includes a 90 first part when the center of the inside of the curve is taken to be at 0 and the center of the outside of the curve is taken to be at 180. A third region includes a 0 third part. A fifth region includes a 270 fifth part. A seventh region includes a 180 seventh part. The radii of curvature of the respective outer surfaces of the third part and the seventh part are larger and the radii of curvature of the respective outer surfaces of the second part and the sixth part are smaller than the radii of curvature of the respective outer surfaces of the fourth part and the fifth part.

A plate assembly for a motor vehicle may include a first plate, a second arranged substantially parallel to the first plate, the second plate defining a plurality of perforations, and a mesh core including a plurality of wire bundles, the core arranged between the plates, wherein the mesh core is rigidly joined to an inner surface of each plate via the perforations.

A hollow stabilizer has a tubular shape and is provided with a torsion section that is provided to a vehicle and that extends in the vehicle width direction; an arm section that extends in the front-back direction of the vehicle; and bent sections that connect the torsion section and the arm section. The hardness of the outer surface of the bent inner sides of the bent sections of the hollow stabilizer is 70% or more with respect to the hardness of the outer surface of the arm section.

A method of manufacturing a hollow stabilizer includes a forming step of subjecting an element pipe to a bending process, to form a product shape including bent portions, and a quenching step of quenching the element pipe subjected to the bending process. In the quenching step, a cooling process is performed by immersing the element pipe made of steel in coolant and by spraying the coolant to an outer surface of the bent portion.

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.

A stabilizer including: a main body for generating an elastic restoring force; and connecting portions formed on both ends of the main body and respectively connected to left and right suspension devices. Hardness of the connecting portions is lower than that of the main body. A method for manufacturing the stabilizer includes, in order, an entire body heat treatment process for heat treating an entire stabilizer and increasing hardness of the entire stabilizer, and a connecting portion softening process for heating the connecting portions and reducing the hardness of the connecting portions. The method for manufacturing the stabilizer thereby increases hardness of the main body and reduces the hardness of the connecting portions lower than that of the main body.

This stabilizer link includes a metal support bar, and ball joints that are provided at both ends of the support bar. Each ball joint includes a ball stud one end of which is fastened to a suspension device or a stabilizer, and which has a ball part at the other end thereof, and a housing that rotatably supports the ball part of the ball stud. The support bar includes: a body part extending in a nearly linear shape, and reinforcement parts each having a nearly annular shape and each provided at both ends of the body part. The reinforcement parts of the support bar are each embedded in the housing so as to surround the ball part.

The present disclosure relates to a method for producing a leaf spring 1 for a vehicle axle suspension, wherein the at least one spring arm 5 bordering on a clamping portion 2 is formed from a rod-shaped preliminary material 7, 8 by a rolling process. By the rolling process for shaping the leaf spring a preliminary material rod 7, 8 having a rounded cross-sectional geometry is rolled out to produce a rectangular cross-sectional geometry in the clamping portion 2 and in the at least one spring arm 5, and thus the portion of the preliminary material rod 7, 8 provided for forming the clamping portion 2 in the finished leaf spring 1 is also reshaped by the rolling process and as a result a rolled structure is also formed therein.