A tubular spring, such as a coil spring, a torsion-rod spring, and/or a stabilizer for a motor vehicle, may include at least one metal tube element having a tube internal cross section, a tube internal diameter, a tube external diameter, a tube internal wall, and a tube wall thickness. At least one metal foam may be disposed in the tube internal cross section of the at least one metal tube element of the tubular spring in at least one part-region. In particular, the metal foam may be connected in an at least partially materially integral manner to the tube internal wall of the metal tube element. The at least one metal tube element may have an at least partially martensitic structure.

A tubular spring, such as a coil spring, a torsion-rod spring, and/or a stabilizer for a motor vehicle, may include at least one metal tube element having a tube internal cross section, a tube internal diameter, a tube external diameter, a tube internal wall, and a tube wall thickness. At least one metal foam may be disposed in the tube internal cross section of the at least one metal tube element of the tubular spring in at least one part-region. In particular, the metal foam may be connected in an at least partially materially integral manner to the tube internal wall of the metal tube element. The at least one metal tube element may have an at least partially martensitic structure.

A tubular spring, such as a coil spring, a torsion-rod spring, and/or a stabilizer for motor vehicles, may comprise at least one metal tube element having a tube internal cross section, a tube internal diameter, a tube external diameter, a tube internal wall, and a tube wall thickness. At least one metal foam may be disposed in the tube internal cross section of the at least one metal tube element of the tubular spring in at least one part-region. The metal foam may be connected in an at least partially materially integral manner to the tube internal wall of the metal tube element. Further, the at least one metal tube element may have an at least partially martensitic structure.

A tubular spring, such as a coil spring, a torsion-rod spring, and/or a stabilizer for motor vehicles, may comprise at least one metal tube element having a tube internal cross section, a tube internal diameter, a tube external diameter, a tube internal wall, and a tube wall thickness. At least one metal foam may be disposed in the tube internal cross section of the at least one metal tube element of the tubular spring in at least one part-region. The metal foam may be connected in an at least partially materially integral manner to the tube internal wall of the metal tube element. Further, the at least one metal tube element may have an at least partially martensitic structure.

A stabilizer includes a stabilizer main body, and eyes formed on both ends of the stabilizer main body. Through-holes are formed in fastening surfaces of the eyes, respectively. The stabilizer main body is covered with a main body coating film. The eye is covered with an eye coating film whose thickness is less than a thickness of the main body coating film. An inner surface of the through-hole is covered with an inner surface coating film. An incomplete coating portion is formed at a part of the inner surface of the through-hole in a circumferential direction. The incomplete coating portion is located on an extension of a straight line connecting a center of the through-hole and the center of gravity of the stabilizer main body in a side view of the stabilizer main body.

A dual rate torsion bar suspension system is connected to a control arm and includes a first rate torsion bar and a second rate torsion bar connected to one another in order to provide the suspension system with a dual rate torque resistance. A cam mechanism is employed for isolating the second rate torsion bar from the first rate torsion bar.

An elastic member is an elastic member formed of a wire having a cross section that is substantially circular, the cross section being orthogonal to a longitudinal direction, and the elastic member being expandable and contractible in a predetermined direction; and including: a first alloy portion that is made of an aluminum alloy having a tensile strength larger than 950 MPa and equal to or less than 1100 MPa at room temperature; and a second alloy portion configured to cover the first alloy portion, the second alloy portion having a thickness in a radial direction smaller than a radius of the first alloy portion, and being made of an aluminum alloy having a tensile strength of 100 MPa to 650 MPa at room temperature.

A torsion bar spring is disclosed. The torsion bar spring can include a first elongated spring bar made of a resiliently flexible material. The first elongated spring bar can have a first coupling interface portion at a distal end and an interior opening oriented along a longitudinal axis. The torsion bar spring can also include a second elongated spring bar made of a resiliently flexible material. The second elongated spring bar can have a second coupling interface portion at the distal end. The second elongated spring bar can be disposed at least partially in the interior opening of the first elongated spring bar. The first and second elongated spring bars can be directly coupled to one another at the first and second coupling interface portions such that uncoupled portions of the first and second elongated spring bars are rotatable relative to one another about the longitudinal axis.

A torsion bar spring is disclosed. The torsion bar spring can include a first elongated spring bar made of a resiliently flexible material. The first elongated spring bar can have a first coupling interface portion at a distal end and an interior opening oriented along a longitudinal axis. The torsion bar spring can also include a second elongated spring bar made of a resiliently flexible material. The second elongated spring bar can have a second coupling interface portion at the distal end. The second elongated spring bar can be disposed at least partially in the interior opening of the first elongated spring bar. The first and second elongated spring bars can be directly coupled to one another at the first and second coupling interface portions such that uncoupled portions of the first and second elongated spring bars are rotatable relative to one another about the longitudinal axis.

A dual rate torsion bar suspension system is connected to a control arm and includes a first rate torsion bar and a second rate torsion bar connected to one another in order to provide the suspension system with a dual rate torque resistance. A cam mechanism is employed for isolating the second rate torsion bar from the first rate torsion bar.