| The terrain in hilly and mountainous areas is not centralized,the height difference between the ground is large,and the agricultural machinery is more difficult to work than the plain.As a kind of power machinery suitable for agricultural cultivation in hilly and mountainous areas of our country,hilly tractors should not only have the basic characteristics of general tractors,but also have good working performance on slope land,especially the stability of sloping land.With the increasing attention paid to the development of agricultural mechanization in hilly and mountainous areas,the demand for agricultural machinery in hilly areas is increasing day by day.Improve the working efficiency of hilly tractor.The research of hilly tractor is mostly based on the theory that is not yet perfect,and its whole performance evaluation is mainly based on repeated tests.Compared with the traditional statics method,the virtual prototyping technology and the multi-body dynamics simulation technology are used to predict and evaluate the whole performance of the hilly tractor in advance,reduce the cost and shorten the research and development period.Provide technical support for the research and development of hilly tractor.The mechanical system of hilly tractor is very complicated.On the basis of analyzing the present research situation of mountain machinery and its stability performance at home and abroad,this paper relies on the key research and development project "key Technology Research and Development of Hilly Tractor",which is the key item of the National key R & D Program of the Ministry of Science and Technology of the Ministry of Science and Technology.To carry out the design of a new type of 35 horsepower hilly tractor.Using the methods of mechanical analysis,three-dimensional modeling,simulation analysis and indoor model test,the stability analysis and modeling of hilly tractors are carried out.The kinematics simulation analysis of the driving and operating stability of a hilly tractor on longitudinal and lateral slopes with multi-body dynamic simulation software ADAMS is carried out.Firstly,the longitudinal and transverse stability of hilly tractor in running and working on the ramp is analyzed in detail by using the classical mechanics theory.The calculation formulas of slip angle and tilting angle for evaluating the stability of hilly tractor are derived,and the working principle of leveling system of hilly tractor is expounded by designing the front and rear bridge leveling assembly:Secondly,the application of 3D modeling software CATIA to establish the model of hilly tractor engine,clutch,gearbox,differential steering,end transmission,front axle,rear axle and virtual models of various components of the hydraulic device and complete vehicle assembly,imported into the simulation software ADAMS for data processing of vehicle;Thirdly,the kinematics modeling and simulation of hilly tractor is carried out by using multi-body dynamics simulation software ADAMS.The stability of the whole vehicle on the longitudinal and lateral slopes with different slopes is analyzed and the following results are obtained: when driving and operating on the longitudinal 10 °slope and the transverse 15 °slope,by leveling,when the cylinder stroke reaches the maximum,It can make the car reach the level on the ramp;when the slope of the longitudinal slope reaches 35 °or the slope of the transverse slope reaches 30 °,the whole car loses stability in the condition of no leveling;in the condition of leveling,When the slope of the longitudinal slope reaches 45 °or the slope of the transverse slope reaches 30 °,the vehicle becomes a whole vehicle Instability;Finally,the stability chamber test of model car under non-leveling condition is carried out,the error of the longitudinal limit slip angle is 12.20 %,the error of the transverse limit slip angle is 11.03 %,and the reliability and correctness of the three-dimensional simulation model and the simulation result are verified. |
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