Browse Publications Technical Papers 2010-01-1887

Development of Methodology for Steering Effort Improvement for Mechanical Steering in Commercial Vehicles 2010-01-1887

Low steering effort in mechanical steering system is very essential, besides meeting the regulatory norms, to have driving comfort and easy maneuverability on turns. All the components in steering and suspension system plays important role in the resultant steering effort of the vehicle.
Of all the factors affecting steering effort, following are identified as high influencing parameters:
  1. 1
    Steering geometry.
  2. 2
    Steering system compliance.
  3. 3
    Friction in steering system linkages like assembly steering column, assembly steering gear box etc.
  4. 4
    Tyre static friction torque.
Present paper describes the detailed analysis of the influence of each parameter on steering system. The above parameters were studied in isolation as well as in combination, to ascertain their effect on steering effort. In a mechanical steering system, the parameters listed above contribute to 35% on steering effort where-in frictional forces itself contributes to 25%.
Optimization of design and dimensions of steering linkages plays a major role in achieving a particular steering effort value. Usually, this is the only method used for optimization of steering effort in mechanical steering system. However the changes in these parameters affect hard points resulting in changes in brake-steer, bump-steer and Ackerman error values.
The paper explains, the investigating methodology developed for steering effort optimization. The Methodology considers above these two aspects viz. listed parameters affecting steering effort and fine-tuning of design and dimensions (basic step) in a correct balanced manner. Methodology explains systematic approach for dealing with ambiguities in steering effort optimization. Three case studies have been used to explain the influence of various parameters on steering effort and the methodology used for optimization of the same.
Modifications made have enabled to reduce steering effort almost by 38% on the vehicle.


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