手持式吹吸机降噪方法及试验研究

某型号手持式吹吸两用风机噪声过大，需确定噪声源并进行降噪处理。测量声压信号进行频谱分析，并结合工作特性和机器结构判断噪声源。分析得知，噪声来源由三部分组成：电机噪声、叶轮噪声和气流在流道内因风阻产生的噪声。根据噪声源的特点，分别采用了3种方法降噪：a.更换电机轴承，改善电刷压力调节系统并电刷浸油处理；b.5片叶轮改为7片叶轮，轮片边缘倒30°圆角；c.改变气流流道及进、出风口的结构。进行了噪声声功率级测试试验,结果表明,整机工作状态噪声降低了约22dB，达到了国标中噪声限制标准的要求。

Research on Noise Reduction Method and Test of Hand-Held Blower-Vacuum

The excessive noise of a hand-held blower-vacuum can be reduced with certain modifications. Spectrum analysis confirms the source of the noise as the measured acoustic pressure signal, performance characteristic and physical construction of the hand-held blower-vacuum. The noise is composed of electromotor noise, impeller noise and windage noise in the duct. Based on these sources, three approaches are applied in order to reduce the electromotor noise. First, the motor bearing is changed, and the brush pressure regulation system and brush immersion oil are improved. Second, the five-piece impeller is changed to a seven-piece impeller, and the edges of every piece are modified to 30 ofillet. Third, the outlet and inlet structures of the flow passage are modified to reduce the windage noise. Finally, a noise test of the sound power level is implemented. The test results indicate that the noise value is reduced about 22 dB under the normal working state of the hand-held blower-vacuum, thus fulfilling the noise limit requirement.