Methodology to improve the performance of the end-stop buffers of suspension seats

The aim of this study was to optimise the characteristics of the bottom end-stop buffers of compact suspension seats fitted to fork lift trucks with a load-lifting capacity of less than 3.5 tons, earthmoving equipment, farm tractors and plants intended for forestry work. This work required the development of a numerical model of a seat subject to movements likely to cause impact with the end-stop buffer. The model employs a global approach based on modelling the friction phenomenon of the suspension mechanisms by means of Bouc-Wen's behavior law. After validation, the model was used to calculate the optimal characteristics (stiffness, damping and height) of the bottom end-stop buffers of the seat: Prototypes of optimised end-stop buffers were produced from the optimal characteristics calculated. Comparisons between the nominal end-stop buffers and the optimised buffers were made in the laboratory using the excitation signals recorded in the field. The results show that when the optimised end-stop buffers were fixed to the. seat instead of the nominal end-stop buffers, between 73% and 93% of the maximum achievable gain was obtained at the acceleration peaks.