自脱形コンバインの振動乗心地改善に関する研究（第１報） 上下・前後方向振動軽減座席懸架装置の試作

Abstract

This paper describes the design of a seat suspension system reducing vibrations in both vertical and horizontal directions for head-feeding type combine harvesters.Field experiments were carried out to obtain the vibration characteristics of conventional seat suspensions. Triaxial accelerometers were placed at 2 locations (on the seat and under the seat), and the vibration signals were recorded on the data-recorder. In the experiments, engine speed was kept constant at 3000rpm which is the normal operating speed and forward speed of the combine was set at 3km/h.From the results, we confirmed that the vibration peaked at the frequency of 6Hz produced dominantly from the reciprocating separator during threshing. We tried to design a seat suspension system using springs and dashpots in order to get the transmissibility under 50% in the range of 6Hz frequency.The results showed that our system reduced to about 7dB (VAL) overall, especially about 12dB (VAL) around 6Hz in the vertical direction, and also about 12dB (VAL) overall, especially about 26dB (VAL) around 6Hz in the horizontal direction.The suspension system provided the expected results in terms of vibration reduction efficiency.