A torsion beam of a vehicle torsion beam suspension has a closed cross section. A beam center portion has an inverse substantially v-shaped cross section or a substantially v-shaped cross section. Circumference increasing portions having a longer circumferential length toward the beam ends are disposed at opposite sides of the beam center portion. Each circumference increasing portion has a beam width that is a width in the fore and aft direction of a vehicle body, the beam width gradually increasing toward a beam end, and increasing at a higher rate as a position of the beam width is closer to the beam end.

A coupled torsion beam axle for buckling induction may include a torsion beam, a cross section of which varies laterally, a right axle coupler and a left axle coupler being respectively formed at both end portions of the torsion beam, the torsion beam being provided with a buckling induction member configured to induce buckling deformation by an external load applied to each of the right and left axle couplers.

This torsion beam manufacturing method is a method of manufacturing a torsion beam that includes a uniformly shaped closed cross-sectional portion of which a cross section orthogonal to a longitudinal direction is a closed cross section having a substantial V-shape or a substantial U-shape at any position in the longitudinal direction, and a shape changing portion which has a connection region leading to the uniformly shaped closed cross-sectional portion and including a closed cross section having a shape different from the shape of the closed cross section of the uniformly shaped closed cross-sectional portion. The torsion beam manufacturing method includes pulling process of applying a tensile force in the longitudinal direction to at least the connection region of a torsion beam material including the uniformly shaped closed cross-sectional portion and the shape changing portion, to obtain the torsion beam.

An axle assembly includes a first rail assembly, a second rail assembly and an open-section twist beam connected to the first rail assembly and the second rail assembly. The twist beam includes an upper wall, a lower wall and rear wall wherein the upper wall and the lower wall are connected by the rear wall to define an open portion of the twist beam where the upper wall and the lower wall are separated by a vertical distance. The open portion of the twist beam is forward facing. The axle assembly further includes a torsion bar that extends through and is connected within the open portion of the twist beam.

A traverse strut for use in a twist beam axle assembly is provided. The traverse strut extends along a length and presents a central section; a pair of end sections; and a pair of intermediate sections between the central section and the respective end sections. At least a portion of the central section has a first wall thickness, at least a portion of each end section has a second wall thickness that is greater than the first wall thickness and at least a portion of each intermediate section has a third wall thickness that is greater than the second wall thickness. Additionally, at least two of the central, intermediate and end sections is work hardened. The transverse strut has improved performance and lower weight as compared to other known transverse struts.

[Object] Damage to a surface of a resin bush caused by press-fitting is prevented even when a configuration for positioning during welding is added. [Solving Means] A rolled collar (40) is a steel rolled collar into which a resin bush (90) is pressed-fitted, and which is joined to a joining member by welding. The rolled collar includes a main body part (50) formed in a hollow cylindrical shape, and a clinch part that joins both end surfaces of the main body part together by fitting. The rolled collar includes a notch part (70) formed by cutting off a portion of an annular edge (53) in the main body part. Here, a convex jig determining a position of the main body part at a time of welding is fit into the notch part. The rolled collar includes a cavity part (80) formed to be hollow from an inner circumferential surface side on a wall surface around the notch part to form a clearance (81) between the press-fitted resin bush and an edge portion (71) of the notch part on the inner circumferential surface side.

A torsion beam suspension capable of preventing an abrupt rigidity change in a connection part between a trailing arm and a torsion beam is provided. The present invention is characterized in that in a torsion beam suspension 100 in which to right and left trailing arms 50 extending in a front-rear direction of a vehicle body and swinging vertically, a torsion beam 16 extending in a right and left direction of the vehicle body is joined, two or more types of rigidity adjustment portions 15, 18, 24 and 25 which adjust a rigidity from the trailing arms to the torsion beam are disposed with positions of the rigidity adjustment portions displaced from each other.

The twist axle assembly includes a twist beam which is made of a single integral piece and extends along a length between opposite ends. The twist beam has a middle portion which extends in a first direction and a pair of end portions which extend at least partially in a second direction that is generally transverse to the first direction to reduce twisting stresses within the end portions during operation of the twist axle assembly.

A rear suspension structure includes left and right trailing arms, left and right hub carriers, and a lateral beam. Each hub carrier includes a front arm portion extending in a direction inward in the vehicle width direction and frontward of an axis of the rear wheels, and a rear arm portion extending rearward of the front arm portion. Each trailing arm has a rear end portion coupled to the hub carrier or the lateral beam via a first coupling portion that is a bushing. The lateral beam includes a left beam extending inward in the vehicle width direction from the rear arm portion disposed on a left side of the vehicle, a right beam extending inward in the vehicle width direction from the rear arm portion disposed on a right side of the vehicle, and left and right second coupling portions displaceably coupling the left beam and the right beam.

A torsion axle assembly for supporting of a vehicle body on an undercarriage, including an elongated inner member having an inner member longitudinal axis; a torsion arm interconnected with the elongated inner member and the undercarriage; an elongated enclosure interconnected with the vehicle body and having an interior space; and resilient polymeric material residing within the interior space to support the elongated inner member within the interior space, such that the inner member longitudinal axis resides at an unloaded camber angle to an elongated enclosure longitudinal axis when none of the weight of the vehicle body is borne by the torsion axle assembly and at a loaded camber angle when the weight of the vehicle body is borne by the torsion axle assembly, such that the unloaded camber angle is greater than the loaded camber angle. A vehicle having such a torsion axle assembly and a method are disclosed.