Study on Noise Control of Agricultural Machines by Sound Intensity Method

本研究利用声强法（sound intensity Method， SIM）确定了头喂式联合收割机周围的声强、声压值和方向，并对操作人员座位区域进行了调查。进行了几项试验，其中一项是将小麦喂入联合收割机的操作部分。测量了超过90 dB的声压值。由SIM绘制的几个矢量图显示了一个主要的声音流穿过操作员的座位和操作员头部的假设位置。这些声音流来自较低的后部（发动机和脱粒机），并被引导到前部，略微上升。由于这些声流的起源位置有两个主要的声源，因此这些声流在操作人员的头部被引导到左边和右边。利用本研究的结果，有可能为今后的噪声预防措施研究和实验提供指导。

This research has determined sound intensity and pressure values and directions around the head-feeding type combine harvester by using the Sound Intensity Method(SIM), and has been conducted to investigate the area of the operator's seat. Several experiments were carried out, one of them was by feeding wheat into the operating parts of the combine harvester.Sound pressure values of over 90 dB were measured.Several vector graphs plotted by the SIM showed a major sound flow across the operator's seat and the assumed location on the operator's head. These sound flows came from the lower backside(engine and thresher) and were directed to the front, slightly going up. As there were two major sound sources at the location of the origin of these sound flows, these sound flows were directed both to the left and to the right across the operator's head.Using the results of this research, it is possible to give guidelines for future reseach and experiments with noise provention measures.