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Traditionally coil springs were used for applications to exert one-dimensional force along a given spring coil axis. However, in recent years, there has been an increasing trend in using coil springs to provide forces in a multi-dimensional space. In this paper, an approach to construct a model of a coil spring for suspension systems using a spatial six degree-of-freedom parallel mechanism is presented. In kinematics and dynamics simulation, the use of a parallel mechanism to model a coil spring allows a designer to simulate six degrees of freedom spring characteristics with vehicle kinematics without using FEA feature embedded in the simulation software. This requires a significant amount of computational load and maybe a file format converter.

Friction caused by side force on a damper axis results in riding discomfort. In order to cancel the side force, accurate shape control for coil springs have been recently become crucial. After designing a target coil shape using a finite element analysis (FEA), actual coiling processes can be done by a NC coiling machine(C/M). The problem with this method is that the NC coiling machine has its own characteristics which coiling experts have to consider when adjustments are made to the control points of the NC machine. This adjustment process usually takes significant amounts of time in order to meet the target coil shape, because the coiling experts do their adjustments by a conventional method based on their experience. This paper describes how to automate the control point design process to reduce the coiling effort and to save time. An ARMA model is used for the coiling machine modeling and its dimensions are determined by the physical dimension of the actual coiling machine.

Finite element analysis of suspension coil springs is standard practice for investigating spring behavior during compression. One increasingly important aspect of spring behavior under recent demand is precise control of the spring's force line. Proper control reduces side loading on the damper assembly, which increases ride comfort. The force line is the reaction force axis produced by a coil spring and its interaction with the spring seats during compression. Not only does the geometric configuration of the spring and seats affect the force line, but it has also been seen experimentally that the spring seat material has an effect. Elastomeric materials such as rubber are used in spring assemblies to reduce noise, vibration, and harshness (NVH), but their influence to spring force line axis has yet to be investigated. The construction and results of several finite element simulations will be presented, correlating various configurations and experimental data.

The purpose of this study is to validate a reverse engineering based design method for automotive trunk lid torsion bars (TLTB) in order to determine a free, or unloaded, shape that meets a target closed shape as well as a specified torque. A TLTB is a trunk lid component that uses torsional restoring force to facilitate the lifting open of a trunk lid, as well as to maintain the open position. Bend points and torque of a TLTB at a closed trunk position are specified by a car maker. Conventionally, a TLTB supplier determines bend points of the free shape by rotating the given bend points from a closed position around a certain axis to satisfy the specified torque at the closed position. Bend points of a deformed TLTB shape in the closed position often do not match the target bend points given by a car maker when designed by the conventional method, which can potentially cause interference issues with surrounding components.