80型轮式装载机结构系统动力特性研究

发布时间：2018-04-24 05:41

本文选题：轮式装载机 + 动力特性　；参考：《吉林大学》2013年博士论文

【摘要】：论文结合“十二五”国家科技支撑计划课题“面向节能与安全的集成智能化工程机械装备研发”(课题编号：2013BAF07B04),依据轮式装载机实际工作情况,建立与其真实结构相符合的11自由度振动系统模型,结合虚拟激励法分析影响轮式装载机结构系统动力特性的主要因素。轮式装载机是铲土运输机械的一种,广泛应用于矿山、建筑、农业、水利等大型工程领域,具有操作便利快捷,机动灵活,易于使用与维修等特点,是重要的工程机械设备之- 就现有我国轮式装载机的设计与研发趋势来看,生产与研发主要集中在3-5吨级机型上,其中尤以5吨级机型最为集中,但随着市场需求形势的变化,工程机械设备的发展日趋大型化,而且,为了提高工程作业效率,对轮式装载机的行驶速度与作业时的整车稳定性也提出了要求。轮式装载机的工作环境通常比较恶劣,路面条件较差,而轮式装载机自身的特点又使得车架与驱动桥之间采用螺栓固定连接,无弹性悬架设备,因而对于中长距离行驶及转场行驶工况,整车结构无法有效的缓冲和衰减高速行驶带来的冲击和振动,影响驾驶员的身心健康,降低装载机零部件的工作可靠性和使用寿命,成为制约轮式装载机向高速化、高效化发展的重要因素。因此,有必要对大型轮式装载机结构系统动力特性进行系统与深入的研究,找到影响其结构系统动力特性的相关因素,既能够有效改善驾驶员的操作舒适度,保持运载货物的完整性,又能够为日后装载机的发展与改进提供一定的理论依据。本文基于试验实测数据,建立工作装置悬置弹性等效模型并根据实际工况对其动态特性进行分析,分析主要弹性减振组件的力学特性,建立与实际结构相符合的轮式装载机空间11自由度系统振动模型,使用虚拟激励法对轮式装载机结构系统动力特性进行系统研究,分析影响轮式装载机结构系统动力特性的主要因素,着重考虑外部激励变化,系统各响应量的变化规律,为提高轮式装载机的结构系统动力特性提供了理论依据,亦可作为机型改进与部件升级的理论参考。本文根据80型轮式装载机技术数据建立其工作装置与前车架的刚—弹耦合模型,对80型轮式装载机工作装置正载与偏载工况的作业循环进行仿真,求得正载与不同偏载位置时,工作装置各关键铰点的受力,得出了偏载作用位置对不同铰点受力影响的变化规律。仿真结果表明,工作装置中受力最大的铰点是动臂与前车架铰接点,偏载工况下,这一铰点受力情况更为严峻。通过仿真分析得到作用于工作装置动臂油缸与铲斗油缸上的力,这是分析动臂油缸与铲斗油缸动态工作特性的基础。本文对80型轮式装载机工作装置油缸的动态工作特性进行了研究,通过试验获得80型轮式装载机一个铲装循环工作油泵出口压力和动臂油缸以及铲斗油缸的有杆腔与无杆腔压力特性,建立开启与关闭行驶稳定系统两种不同工作状态下油缸的力学模型,得到其刚度系数和阻尼系数的通用表达式,基于试验实测数据研究工作装置动臂油缸和铲斗油缸的动态特性,得出了不同工况下动臂油缸和铲斗油缸的刚度系数与阻尼系数曲线,分析系统各参数对油缸的动态特性的影响。本文建立轮式装载机弹性减振组件—座椅、橡胶减振器和轮胎的动力学模型,根据实际工况分析影响减振组件动力特性的各项因素。研究结果表明空气悬挂式轮式装载机座椅,在充气压力相同的情况下,可有效保持座椅高度与动力特性的稳定。本文还分析了正载与偏载工况下轮胎的载荷与力学特性,结果表明,在同等工作条件下,轮胎在充气压力为0.39MPa时刚度与阻尼特性最优,结构系统动力特性研究的结果也验证了这一结论。本文系统介绍了虚拟激励法的理论基础,分析采用虚拟激励法研究轮式装载机结构系统动力特性的可行性、准确性与有效性。根据轮式装载机实际结构与工作特点,建立80型轮式装载机整车11自由度系统振动参数化模型,在精确确定各项结构参数的基础上,针对不同工况对80型轮式装载机进行系统动力特性研究,得到人体座椅系统垂血加速度、铲斗质心垂直加速度、车轮及工作装置关键铰点的相对动载等响应量的功率谱密度曲线,确定影响轮式装载机结构系统动力特性的各项因素以及各项因素对各响应量的影响程度,并应用人体对振动主观感受的国家标准作为评价指标,根据驾驶员主观感觉的舒适性程度给出工况组合及参数选择的建议。论文研究表明,本文所采用的参数化振动模型建立方法与虚拟激励仿真方法可适用于不同机型的轮式装载机,具有通用性,拓展了轮式装载机结构系统动力分析模型与仿真方法的应用范围,对轮式装载机的设计与改进具有一定的帮助作用,为未来轮式装载机结构系统动力特性研究具有一定的指导意义。
[Abstract]:The paper combines the "research and development of integrated and intelligent engineering machinery equipment for energy saving and safety" (issue number: 2013BAF07B04) on "12th Five-Year" National Science and technology support program (project number: 2013BAF07B04). Based on the actual working condition of wheel loader, a model of 11 degree of freedom vibration system is established in accordance with the actual structure of the wheel loader, and the influence wheel is analyzed by the virtual excitation method. The main factors affecting the dynamic characteristics of the loader structural system.
Wheel loader is a kind of shoveling soil transport machinery. It is widely used in mine, construction, agriculture, water conservancy and other large engineering fields. It has the characteristics of convenient operation, flexible maneuver, easy to use and maintenance. It is an important engineering machinery equipment.
In view of the current trend of the design and research and development of the wheeled loader in China, the production and research and development are mainly concentrated on the 3-5 ton model, especially the 5 ton grade model, but with the change of the market demand situation, the development of the engineering machinery and equipment is becoming more and more large. In addition, in order to improve the efficiency of the work, the speed of the wheel loader is improved. The stability of the whole vehicle at the time of operation is also required. The working environment of the wheel loader is usually bad and the pavement condition is poor, and the characteristics of the wheel loader itself make the frame and the drive bridge adopt the bolt fixed connection and the inelastic suspension equipment, so the whole vehicle structure is no longer for the medium and long distance driving and the transfer running condition. The method effectively buffers and attenuates the shock and vibration caused by high-speed driving, affects the driver's physical and mental health, reduces the working reliability and service life of the loader parts, and becomes an important factor restricting the high-speed and efficient development of the wheel loader. Therefore, it is necessary to maintain the dynamic characteristics of the structural system of the large wheel loader. The related factors which affect the dynamic characteristics of the structural system can not only effectively improve the driver's operating comfort, maintain the integrity of the cargo, but also provide a theoretical basis for the development and improvement of the later loaders.
Based on the test data, the elastic equivalent model of the working device suspension is established and the dynamic characteristics are analyzed according to the actual working conditions. The mechanical characteristics of the main elastic damping components are analyzed. The vibration model of the wheel loader space 11 degree of freedom system is established in accordance with the actual structure, and the virtual excitation method is used for the wheel loader junction. The dynamic characteristics of the structure system are systematically studied and the main factors affecting the dynamic characteristics of the wheel loader structure system are analyzed. The changes of the external excitation and the variation of the response of the system are considered. The theoretical basis for improving the dynamic characteristics of the structural system of the wheel loader is provided, and the theoretical reference for the improvement of the model and the upgrading of the components is also provided.
Based on the technical data of type 80 wheel loader, this paper establishes a rigid elastic coupling model of the working device and the front frame, and simulates the operation cycle of the positive and partial load conditions of the working device of the 80 wheel loader, and obtains the force of the key hinge points of the working device when the positive and different partial loading positions are located, and the position of the partial load on the different hinge is obtained. The simulation results show that the hinge point of the maximum force in the working device is the joint of the arm and the front frame. Under the load condition, the force of this hinge is more severe. Through the simulation analysis, the force acting on the cylinder of the working arm and the cylinder of the bucket is obtained. This is the analysis of the dynamics of the cylinder and the bucket of the bucket. The basis of the characteristics of the work.
In this paper, the dynamic working characteristics of the 80 type wheel loader's working device oil cylinder are studied. Through the test, the pressure characteristics of the outlet pressure and the arm cylinder of the 80 type wheel loader, and the pressure characteristics of the rod cavity and the non rod cavity of the bucket oil cylinder are obtained, and two different working states are established for the opening and closing of the running stability system. The mechanical model of the lower oil cylinder gets the general expression of its stiffness coefficient and damping coefficient. Based on the experimental data, the dynamic characteristics of the cylinder and the bucket of the bucket are studied. The stiffness coefficient and the damping coefficient curve of the cylinder and the bucket of the bucket are obtained in different working conditions, and the dynamic characteristics of the various parameters of the system on the cylinder are analyzed. Influence.
In this paper, the elastic damping components of the wheel loader - seat, rubber damper and tire dynamics model are established to analyze the factors that influence the dynamic characteristics of the damping components according to the actual conditions. The results show that the seat height and dynamic characteristics of the air suspended wheel loader seat can be effectively maintained under the same inflatable pressure. The load and mechanical characteristics of the tire under both positive and partial load conditions are also analyzed. The results show that the stiffness and damping characteristics of the tire are best under the same operating conditions when the inflating pressure is 0.39MPa. The results of the study on the dynamic characteristics of the structural system also verify this conclusion.
This paper systematically introduces the theoretical foundation of the virtual incentive method, analyzes the feasibility, accuracy and effectiveness of the study of the dynamic characteristics of the structural system of wheel loader by the virtual excitation method. Based on the actual structure and working characteristics of the wheel loader, the vibration parameterization model of the 11 degree of freedom system of the 80 wheel loader is set up. On the basis of the structural parameters, the dynamic characteristics of the 80 type wheel loader are studied in different working conditions. The power spectral density curve of the response of the body seat system drooping blood acceleration, the vertical acceleration of the bucket center of mass and the relative dynamic load of the key hinges of the wheel and working device is obtained, and the dynamic power of the structural system of the wheel loader is determined. The factors of the characteristics and the influence of various factors on the response amount, and the application of the national standard of the human body to the subjective feeling of the vibration are used as the evaluation index. According to the comfort degree of the driver's subjective feeling, the suggestion of the combination of working conditions and the selection of parameters is given.
The research shows that the parametric vibration model building method and virtual excitation simulation method used in this paper can be applied to the wheel loader of different types. It has generality, expands the application scope of the dynamic analysis model and simulation method of the wheel loader structure system, and has some help to the design and improvement of wheel loader. It is of guiding significance for the future research on the dynamic characteristics of wheel loader structural system.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH213.6

【参考文献】