【作者】 潘海兵；

【导师】 刘晋浩；

【作者基本信息】 东北林业大学 ， 机械设计及理论， 2009， 博士

【摘要】 本论文是在“十一五”国家科技支撑计划项目——多功能林木采育作业关键技术装备研究与开发项目的基础上完成的,是此课题研究的一部分。随着轻工业不断发展,轻工业对木材需求量越来越大,仅靠我国现有的采伐机械和设备已经不能满足这样的需求。许多发达国家已经大量使用多功能联合采伐机械,但国内仍未有此类联合采伐机械投入使用。国外多功能联合采伐机械价格昂贵且不适于国内木材生产,因此,课题组研制了首台适用于国内林区采伐作业的采伐机械——多功能联合采伐机。多功能联合采伐机的研制对于提高木材生产效率,降低工人劳动强度具有一定的意义。多功能联合采伐机是集伐木、打枝、造材等功能为一体的智能联合采伐装备。多功能联合采伐机在林地间行进和作业时由于多种原因必然会产生振动。因此,本文首次理论推导出多功联合采伐机行进时的平顺性模型,并且建立了多功能联合采伐机多体动力学模型,对其在不同工况下的运动状态进行仿真,为多功能联合采伐机优化设计提供理论依据。本文首先介绍了国内外采伐机械研究应用的现状,着重探讨了国外几家大公司的联合采伐机械的研究发展现状。多功能联合采伐机具有与普通工程车辆类似底盘结构,因此,为了研究多功能联合采伐机的平顺性,本文对近年来年车辆振动研究概况进行了全面的综述。介绍了多功能联合采伐机的结构,分析了多功能联合采伐机的工作原理,以及它的振动来源。在一些合理的理论简化和条件假设下,建立了多功能联合采伐机的5自由度的振动力学模型。模型主要以多功能联合采伐机外部振源作为振动激励。根据所建立的振动力学模型,运用第二拉格朗日方程理论推导出多功能联合采伐机行进时的振动微分方程。根据振动微分程的矩阵形式,在Matlab＼Simulink环境下采用子系统结构嵌套的方式编制了五自由度振动系统通用的仿真求解模型。五自由度振动系统写成矩阵形式后便可由此模型仿真求解。将多功能联合采伐机的参数采用集中输入方式输入模型,经计算得到多功能联合采伐机振动模型各变量的加速度、速度曲线。经分析,地面激励产生的振动在轮胎和座椅的减振作用下得到了大幅度衰减,但人椅系统的振动频率部分为低频。本文还以Mechanism/Pro模块作为桥梁,将三维设计软件Pro/E和多体动力学分析软件ADAMS协同使用,发挥各自的优点,建立了多功能联合采伐机多体动力学模型。在ADAMS环境中,对多功能联合采伐机在直线行驶、三角凸块激励、伐根激励和驻车作业时运动状态进行了模拟仿真,得到了多功能联合采伐机在不同工况下的运动状态。轮胎和座椅对产生的振动有较好的抑制作用,但人体的瞬时速度和加速度都比较大。可以通过给驾驶增加减振系统和调节座椅刚度和阻尼提高整机的减振性能。多功能联合采伐机五自由振动模型的仿真求解和多体动力学模型的模拟仿真相互映证,映证了多功以联合采伐机动力学模型和振动的模型的合理性。同时,仿真结果对多功能联合采伐机的改进提供了有力的依据。本文对多功能联合采伐机振动模型和仿真模型的建立、对模型仿真求解的方法也对解决类似林业机械振动问题提供了参考和借鉴。更多还原

【Abstract】 This thesis is finished based on the State Eleventh Five-year Scientific and Technological Support Project——The Research and Explore of the Multifunctional Key Technical Equipment on the Forest Harvesting and Cultivating Operation.This thesis is also one part of the project.With the continuous development of the domestic light industry,their demand of wood is more and more big,which is not satisfied only by the domestic harvesting machinery and equipment.Though many countries already have a large number of the multifunctional harvesting machinery,there wasn’t such harvesting machinery in our country.Abroad multifunctional harvesting machinery is so expensive,and they are not suit for the domestic wood production.So,the study team develops the first multifunctional harvester that is more suitable for the domestic forest harvesting operation.The development of the multifunctional harvester has certain significance to improve wood productivity and inducing labor intensity of wood workers.The multifunctional harvester is an intelligent equipment which concentrates the functions felling,delimbing,scaling,cross-cutting,and so on.When it is driving and working,it would vibration inevitably because of certain causes.So,the ride comfort model of the multifunctional harvester while driving is built in the first time.And its multi-body dynamic model is also built in the first time.Based on the model,the movement states of the multifunctional harvester are simulated on different work situation.The results provide the theory proof to the further improvement of the multifunctional harvester.The research and development status of the harvesting machinery home and abroad are in introduced.Especially the research and development status of several abroad big company harvesters is discussed.The multifunctional harvester has similar chassis to the common vehicles.So,the general situation of the recent research on the vibration system of the vehicle was summarized with the aim of providing some useful information for the research of the harvester ride comfort.The structure of the multifunctional harvester is introduced.Working operation and vibration source of the multifunctional harvester is also analyzed.Though the reasonable necessary academic simplification and reasonable condition hypothesis,five-degree-of-freedom vibration mechanical model of the multifunctional harvester is built.The excitation of the vibration model is mostly the outer vibration excitation of the multifunctional harvester. According to the built vibration mechanical model,the vibration differential equation is derived by using the second kind Lagrange equation in the first time.Based on the matrix form of the vibration differential equation,the universal solver of the five-degree-of-freedom vibration system is built in the Matlab\simulink software.Most five- degree-of-freedom vibration system can be all solved after transformed the matrix form.By the intensive input way,input all the value of the parameters to the solver program,the acceleration,velocity,displacement curve of the all model parameters are obtained by computing.Though analysis,vibration generated by ground excitation is weaken owing to the tyres and seat.But the frequency of the man-seat is in the low frequency,so the vibration reduction performance of the seat should be improved.The multi-body dynamical model of the multifunctional harvester is established in the first time by combining the Pro/E software and ADAMS using Mechanism/Pro as bridge, which exerts their advantages.In the ADAMS,the states of the multifunctional harvester is simulated when it is driving straightly,excited by triangle bump and tree stump,working too. So,the vibration state in all conditions is obtained.The tyres and seats have good vibration reduction,but the instantaneous velocity and acceleration is large.So the vibration reduction of the harvester needs to improve.The solution of the five-degree-of-freedom vibration system and simulation of the multi-body dynamical model of the multifunctional harvester prove that the vibration model and the multi-body dynamical model are reasonable.In the same time,the results supply the evidence to improve the multifunctional harvester.This thesis also offers the ways and reference to study the similar forestry machine vbirtaion.更多还原