【作者】 李建华；

【导师】 余强；

【作者基本信息】 长安大学 ， 车辆工程， 2005， 硕士

【摘要】 平顺性是振动压实机械一个重要的性能,它与驾驶员的舒适性、零部件的可靠性以及使用寿命有着密切的关系。目前,对于振动压实机械的研究主要集中在振动轮激振力、压实效果和参数优化设计等方面,对于平顺性缺乏深入系统的研究。为此,很有必要对振动压实机械的平顺性进行深入系统的研究。 振动压路机作为振动压实机械中使用最广泛、压实效果较好的一个种类,具有较强的代表性。本文以YZ12T型振动压路机为例,通过对该振动压路机的结构分析,建立了反映轮胎驱动振动压路机的7自由度振动模型。利用拉格朗日方程,建立了该模型的微分方程组,用理论分析的方法,求出了三个测点处的加速度功率谱密度,并用Matlab语言编制了相应的模拟计算程序。 同时进行了YZ12T型振动压路机的平顺性试验,分别用1/3倍频带评价法和加权加速度均方根值法对采集的数据进行了分析,评价了该压路机的平顺性性能。试验说明在压路机振动轮激振力频率处于低频振动阶段时,压路机的平顺性很差;在以2.0km/h的速度行驶、激振力频率处于中频和高频阶段时,平顺性较好;在以4.1km/h的速度行驶、激振力频率处于中频和高频阶段时,平顺性较差。通过分析试验数据的加速度功率谱密度,发现发动机对整机的振动特性有一定的影响:在激振力频率处于低频阶段时,发动机的影响很小;在中频阶段时,对驾驶室地板处和驾驶员座椅处有一定的影响,但是对前机架处的影响很小;在高频阶段,发动机对驾驶室地板处和驾驶员座椅处有较大的影响,但对机架测点处的影响比较小。 通过对比模拟数据和试验数据,滤除发动机因素的影响,二者基本一致,验证了模型的有效性和可靠性。利用编制的模拟计算程序,采用单因素分析法,分析了各参数对驾驶员座椅处振动位移的影响:在激振力频率大于20Hz后,各参数对驾驶员座椅处振动影响较小;各参数对座椅振动影响较大的区域在激振力频率为10Hz附近的共振区。利用单自由度振动模型,对机架减振装置和座椅的减振效果进行了分析,得出当激振力频率大于系统固有频率的2^1/2倍时,减振装置才能起到减振隔振的作用。更多还原

【Abstract】 Ride comfort is one of prime performance of vibratory compaction machinery, which is closely relative to drivers’ comfort, reliability and life of parts of machinery. At present, study on vibratory compaction machinery is prime concentrated on vibratory force, press effect and parameter optimization design and study on ride comfort is very insufficient, so it is very necessary to discuss ride comfort of vibratory compaction machinery.Vibratory roller is one kind of vibratory compaction machinery, which is used most widely and press effect of is more better. This paper takes YZ12T vibratory roller as an example. According to the analysis of the vibratory roller structure characteristics, a seven freedom degrees vibratory roller model which can reflect vibration of the tyre driven vibratory roller is established. Using Lagrange differential equation, a differential equation set of the vibratory roller model is set up and acceleration power density spectrum of three test spots are gained. Simulation calculating programs are developed with Matlab programming language.The ride comfort experiment of YZ12T vibratory roller is carried out. The 1/3 octave band and weighed accelerations are exploited to estimate the ride comfort of the vibratory roller. Test results show that the ride comfort is very bad when the vibratory force is in the condition of low frequency flap and the ride comfort is somewhat better when the speed of the vibratory roller is about 2.0km/h and the vibratory force is in the condition of medium and high frequency flap and the ride comfort is somewhat worse when the speed of the vibratory roller is about 4.1km/h and the vibratory force is in the condition of medium and high frequency flap. Analyzed the acceleration power density spectrums of the test data, it can be found that the engine’s vibration has little influence on the test spots’ vibration under low frequency flap; under medium frequency flap, the engine’s vibration has a little influence on vibration of the cab floor and driver’s seat but has little influence on vibration of the frame; under high frequency flap, the engine’svibration have great influence on vibration of the cab floor and driver’s seat but has little influence on vibration of the frame.Eliminated the influence of the engine’s vibration, simulation results are basically corresponded with test results and the availability and reliability of the model are verified. Using the simulation calculation program and adopting the single factor analytic approach, simulation results are gotten and conclusions can be drawn from the simulation results. The parameters have a little influence on vibration of the driver’s seat when the frequency of the vibratory force is larger than 20Hz, and the zone that the parameters have great influence on vibration of the driver’s seat is nearby the sympathetic vibration frequency of the system which is about lOHz. Using one freedom degree vibration model, vibrating absorption effect is discussed and conclusion that absorber can take vibrating absorption effect only when vibratory force frequency isV2 times of inherent frequency of the system is drawn.更多还原