A vehicle rear suspension structure includes a torsion beam and a pair of arm units. Each of the arm units includes a trailing arm formed in a tubular shape extending in the vehicle front-rear direction, an end plate occluding a rear side opening of the trailing arm, an upper reinforcing member, and a lower reinforcing member. A shaft insertion hole is formed in an inner side portion of a rear arm of the trailing arm, the upper reinforcing member is joined to the rear arm to fit an upper side edge portion of a peripheral edge portion of the shaft insertion hole, and the lower reinforcing member is joined to the rear arm to fit a lower side edge portion of the peripheral edge portion of the shaft insertion hole.

A manufacturing method of a member according to an aspect of the present invention is a manufacturing method of a member including a specific three-dimensional tubular portion, the manufacturing method including: a U-forming step of performing U-forming on metal material sheet using a U-forming die and punch including a U-forming punch to manufacture a U-formed article having a recessed cross-sectional shape; and an O-forming step of causing side end portions of the U-formed article to abut each other by an O-forming die to form abutting portions, in which a forming condition ratio a=Du/Do is set to 0.85 to 0.95.

A twist beam for a suspension of a motor vehicle comprises a body-side inner part having a bearing-receiving section for receiving a body-side bearing, and a wheel carrier-side outer part having a bearing-receiving section for receiving a wheel carrier-side bearing, the outer part and the inner part being separate components which are made of different materials and are firmly connected to each other.

A coupled torsion beam axle (CTBA) bushing is press-fitted into a bushing bracket provided at a tip of a trailing arm at each of two opposite sides of a CTBA suspension system. In particular, the CTBA bushing includes: an outer pipe including a through-hole formed therein; an inner pipe positioned in the through-hole; and a bushing rubber disposed in the through-hole and positioned between an outer peripheral surface of the inner pipe and an inner peripheral surface of the outer pipe, in which the bushing rubber includes: first compounds extending in a first direction, which is a diameter direction of the inner pipe, with the inner pipe interposed therebetween; and a second compounds integrated with the first compounds and extending in a second direction, which is perpendicular to the first direction, with the inner pipe interposed therebetween.

The present invention provides a method for manufacturing a torsion beam, the method comprising: a planarization step, in which a protruding portion of an upper mold presses the opposite end portions in the width direction of the blank to be plastically deformed to be flat while the opposite end portions in the width direction of the blank are supported by a side cam to face each other; a welding and bonding step for bonding the planarized opposite end portions in the width direction of the blank via welding; and a quenching step for heating the welded and bonded blank within a range of 900 to 970° C. for a retaining time within a range of 1 to 20 minutes and for cooling down the blank in a treatment liquid including at least one of water and oil in a range of 20 to 90° C.

Disclosed are a steel plate for a torsion beam and a manufacturing method therefor, and a torsion beam and a manufacturing method therefor. The steel plate for the torsion beam has the following chemical components in percentages by mass: 0.04-0.085% of C, 0.02-0.5% of Si, 1.3-1.8% of Mn, 0.15-0.5% of Cr, 0.12-0.30% of Mo, 0.058% or less of Nb, 0.15% or less of V, 0.02% or less of Ti, 0.02-0.1% of Al, 0.02% or less of P, 0.005% or less of S, 0.005% or less of N, and the balance being Fe and inevitable impurities. The steel plate has one or two of Nb and V, and the amount of Nb and V satisfies 0.096%<2Nb+V<0.17%. The steel plate for the torsion beam of the present invention has an excellent elongation and excellent cold bending properties while ensuring high strength, and meets the requirement for producing lightweight torsion beams.

A torsion beam suspension includes two trailing arm portions, in which each of the trailing arm portions includes an elastic supporting portion and an extending portion, and the extending portion extends from the elastic supporting portion toward an inner side of a vehicle body in a width direction, and a torsion beam fixed to the extending portion of each of the trailing arm portions.

Disclosed herein is a coupled torsion beam axle type rear suspension system that includes a coupled torsion beam axle (100) installed to extend in a transverse direction of a vehicle body, a pair of trailing arms (200) coupled to respective ends of the coupled torsion beam axle (100), and a transverse leaf spring (300) having both ends connected to the respective trailing arms (200) and a center portion connected to a body cross member (40), thereby reducing the number of parts and improving driving stability.

Disclosed herein is a coupled torsion beam axle type rear suspension system that includes a coupled torsion beam axle (100) installed to extend in a transverse direction of a vehicle body, a pair of trailing arms (200) coupled to respective ends of the coupled torsion beam axle (100), and a transverse leaf spring (300) having both ends connected to the respective trailing arms (200) and a center portion connected to a body cross member (40), thereby reducing the number of parts and improving driving stability.

A suspension assembly for a commercial vehicle includes a first linkage, an air spring, a carriage, and a second linkage. The first linkage is pivotally coupled at a first end with a structural member of a frame. The structural member extends downwards from the frame. The air spring is coupled with the frame and a second end of the first linkage. The air spring drives the first linkage to pivot about the first end relative to the structural member. The carriage is pivotally coupled with the first linkage at a position between the first end and the second end of the first linkage. The second linkage is pivotally coupled at a first end with the structural member, and pivotally coupled with the carriage at a second end. The structural member, the first linkage, the second linkage, and the carriage define a four-bar linkage.