Engineering machinery generally operates under harsh working conditions, and drivers have to withstand both vibrations transmitted from structures such as engines and excitation from uneven road surfaces (mainly low-frequency vibrations). The seat is a structure that directly contacts the driver and serves as the last link to reduce the transmission of vibrations to the human body. Today I will teach you how to determine the comfort level of engineering machinery seats.
The common structures of engineering machinery seats mainly include headrests, backrests, seat cushions, sliding rails, and shock absorbers. Due to the generally slow movement speed of construction machinery (such as pavers and rollers), some models of seats may not have structures such as headrests to save costs.
The seat cushion and backrest are equipped with foam and covers with moderate hardness, which can reasonably distribute human pressure. The seat design has multiple adjustment mechanisms, which can facilitate the driver to adjust to a comfortable driving posture. The bottom of the seat is usually equipped with shock absorbers, which are usually supported by two cross arranged connecting rods and prevented from exceeding the design travel by elastic limit blocks and limit straps. This type of damper is equipped with a spring on one side of the connecting rod, and a damper is inclined in the vertical direction of the damper, which has the characteristics of simple structure, high reliability, and long service life.
The lower the stiffness of the seat shock absorber, the better the riding comfort. However, a too small stiffness may increase the travel of the seat cushion plane, which may not only cause collision with the seat structure and affect comfort and operability, but also reduce the service life of the spring. If the damping of the seat shock absorber is too small, it will increase the resonance frequency and easily overlap with the sensitive frequency area of the human body, reducing ride comfort. If it is too large, it will significantly reduce seat ride comfort due to the rigid impact of the shock absorber. Therefore, it is necessary to comprehensively select the dynamic parameters of the shock absorber based on various influencing factors. By optimizing the matching of stiffness and damping, the vibration reduction performance of the seat under specific working conditions can be improved.