Multi-piece siderail for medium and heavy trucks

Abstract

A multi-piece siderail is fabricated for use as a truck frame which has potential cost and weight reductions while also providing superior weight loading characteristics. Each section of the multi-piece siderail includes a webbed portion having longitudinal ribs that form alternating protruding and recessed sections. An upper and a lower flange are provided on each section and each flange is formed with a stepped, lipped configuration. The unique structure of each section provides increased rigidity and support to that section and also allows for a nesting arrangement between each of the three components. Furthermore, this structure provides multiple attachment zones throughout the frame—two zones on each flange and three zones on the front and rear section webs and five zones on the center section web. Each of these attachment zones are surrounded by a work hardened corner to provide reinforcement. To further increase strength and provide for sound joints, a support member is inserted between the middle component, which is often deeper, and the front and rear components. Specifically, the support member, having a Z-shaped cross-section, is inserted between the lower portions of the respective deep and shallow sections. Thus, a multi-piece siderail can be utilized in truck frame applications, allowing for reduced weight and reduced over all production costs, while providing superior performance characteristics such as greater payload and/or better fuel economy. The design also allows for potential section commonality and flexibility in assembly.