Study on Noise Control of Agricultural Machines by Sound Intensity Method

本研究利用声强法（SIM）测定了头部喂入式联合收割机收割机周围的声强、声压值和方向，并对操作员座椅区域进行了调查。在联合收割机上进行了小麦喂入试验，测得90 dB以上的声压值，用SIM绘制了几幅矢量图，显示了主要的声流经过操作员座椅和假设的操作员头部位置。这些声音流来自较低的背面（发动机和脱粒机），并被引导到前面，略有上升。由于在这些声流的起源处有两个主要声源，这些声流在操作者的头部被引导到左侧和右侧。利用本研究的结果，可以为将来的研究和实验提供指导，噪声防治措施。

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.