Filled tubular torsion bar and its method of manufacture

Abstract

Abstract A hollow torsion bar reinforced by a mixture of resin and filler and method of making such a torsion bar. The torsion bar is formed from mild or medium grade steel seamless or welded tubing. The tubing is cut to length and charged preferably with a mixture of substantially uncured thermoset resin and plastic or glass hollow microspheres and/or metal pellets. The mixture may be charged into the tube by injection as a paste or by placing inside the tube a B-stage form insert having preferably between about 10 and 50 percent elongation tensile strength. After the tube has been charged with the reinforcing mixture, the tube is bent to form a torsion bar having a radius arm and a spring portion. In areas that the torsion bar is bent, the reinforcing mixture is provided to act as an internal mandrel preventing collapse of the tube walls. The mixture is then cured and bonded in place by chemical reaction of the rein or by thermally curing the resin mixture within the tube. The mixture, upon curing, bonds to the walls of the tube and increases in compressive and shear strength and has a lower percent elongation. Bonding to the tube walls may inherently occur if the resin used in the mixture is an epoxy resin. The mixture imparts substantial vibration damping and acoustic attenuation. In one aspect, the core constitutes a plurality of bonded-together plastic syntactic pellets which define a network of interstices rendering the torsion bar even more lightweight and acoustically desirable.

Inventors

• 👤 Joseph Wycech

Bibliographic Details