锥形节流阀空化振动与噪声研究

发布时间：2018-05-14 02:19

本文选题：锥形节流阀 + 空化振动　；参考：《中国矿业大学》2017年硕士论文

【摘要】：锥形节流阀是液压系统应用最广泛的核心控制元件,对液压系统性能好坏起关键作用。但是在节流阀口处通常会有空化产生,空化引起的振动和噪声十分严重。空化噪声的声压级分贝比较高,对环境和人的影响是不能忽视的,而空化振动会影响系统的稳定运行,甚至对系统中的液压元件造成损坏。本文针对节流阀的空化振动和噪声实验测试了空化的振动强度和空化噪声声压级,采用信号的功率谱密度方法,分析了空化振动和噪声信号的频谱特征。针对液压系统中液压节流阀空化引起的振动和噪声问题,采用理论分析和实验分析相结合的方法进行了研究。实验中采用振动噪声仪器对空化信号分析,用加速度传感器采集空化振动的信号和麦克风压力传感器采集空化噪声的信号,采集空化振动和噪声信号的同时用高速摄像机获取测试阀中节流阀口空化形态的图像信息。结果显示,相对无空化状态,当节流阀产生空化时,振动信号的振动强度和噪声声压级的量级增加。分别研究测试节流阀在不同入口压力、出口压力和开度下的空化信号的特征,得到空化振动和噪声声压级的变化趋势,通过频谱分析空化信号在频率上的特征。研究发现空化振动和噪声信号的频率在5000Hz以上,得到测试节流阀中游离型空化的振动频率在7500-10000Hz频率范围内,并且存在一定的频移现象,固定型空化的频率在10000-15000Hz范围内。随着入口压力的增加,空化强度随之增加,空化振动强的和空化噪声声压级增加;随着阀腔背压的增加,空化强度随之减弱;随着开度由小变大,空化强度先增加后减小。一级节流阀相比二级节流阀引起的空化程度更高,空化区域也更大;不同阀芯锥角对空化发生程度也有较大影响。在二级节流阀座下,90°阀芯锥角比60°阀芯锥角引起的空化程度更剧烈。
[Abstract]:Conical throttle valve is the most widely used core control element in hydraulic system, which plays a key role in the performance of hydraulic system. However, cavitation usually occurs at throttle orifice, and the vibration and noise caused by cavitation are very serious. The sound pressure level of cavitation noise is relatively high, and the influence on environment and human can not be ignored. However, cavitation vibration will affect the stable operation of the system and even damage the hydraulic components in the system. In this paper, the cavitation vibration intensity and cavitation noise sound pressure level are measured by experiments on cavitation vibration and noise of throttle valve. The spectral characteristics of cavitation vibration and noise signals are analyzed by using the power spectrum density method. The vibration and noise caused by cavitation of hydraulic throttle valve in hydraulic system are studied by combining theoretical analysis with experimental analysis. In the experiment, the cavitation signal is analyzed by vibration noise instrument, the signal of cavitation vibration is collected by acceleration sensor and the signal of cavitation noise is collected by microphone pressure sensor. The cavitation vibration and noise signals were collected and the image information of the throttle orifice cavitation in the test valve was obtained by high speed camera. The results show that the vibration intensity of vibration signal and the magnitude of noise sound pressure level increase when the throttle valve is cavitation. The characteristics of cavitation signals under different inlet pressure, outlet pressure and opening degree of throttle valves are studied, and the variation trends of cavitation vibration and noise sound pressure levels are obtained. The frequency characteristics of cavitation signals are analyzed by spectrum analysis. It is found that the frequency of cavitation vibration and noise signal is above 5000Hz, and the vibration frequency of free cavitation in the test throttle is in the range of 7500-10000Hz frequency, and there exists a certain frequency shift phenomenon, and the frequency of fixed cavitation is in the range of 10000-15000Hz. With the increase of inlet pressure, the cavitation intensity increases, the sound pressure level of cavitation noise increases with strong cavitation vibration, the cavitation intensity weakens with the increase of back pressure of valve cavity, and the cavitation intensity increases first and then decreases with the increase of opening degree. Compared with the secondary throttle valve, the primary throttle valve has higher cavitation degree and larger cavitation area, and the different cone angle of the valve core has great influence on the cavitation degree. The cone angle of 90 掳valve core under the secondary throttle seat is more intense than that caused by 60 掳cone angle.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH137.522

【参考文献】