| China's forest areas have many mountainous,hilly,and complex site conditions,and there are problems with the forestry equipment capabilities in mechanization.It is extremely important to develop and design a multi-functional obstacle crossing chassis for forests in different site environments.For the design of a forest six-wheel chassis model,the turning radius is too large,the structure size and mass are too large,and the structural power source is not clear.The three-degree-of-freedom structure and the luffing wheel leg structure are improved and optimized,which improves the ability of the chassis to steer performance,ride over obstacles,pass through obstacles,etc,so that it can provide better ground profile performance on the forestry chassis.The research content and method of this paper are as follows:1.According to the designed chassis model,the function and structure are redefined,and the steering structure and obstacle-crossing components are redesigned.The steering structure has a 30 ° roll angle adjustment and a 45 ° pitch angle adjustment,and has a 47 ° steering angle,which reduces the turning radius by means of waist turning and improves the steering flexibility and road profile of the chassis..Based on the overall hydraulic driving principle,the mathematical model and theoretical model of the obstacle-crossing components were rebuilt,the structure size was reduced by 10%,the obstacle-crossing height was increased by 12.7%,and the working capacity of the chassis in different woodland environments was improved,ensuring the chassis Obstacle smoothness at work.The cooperation between the two makes the chassis adapt to complex terrain conditions.2.Static reanalysis of the redesigned steering and obstacle crossing components,analysis of stress and strain under full load and extreme working conditions,and topological optimization design based on the analysis results,redesigned hole and weight reduction Structure to reduce the overall mass of the structure.The results show that the designed steering and obstacle-obstructing structure meets its own load limit and can achieve corresponding structural movement.3.Aiming at the working state and working mode of the steering and wheel-leg components,the simulation of the components was carried out through ADAMS.It mainly analyzes that the independent motions of the three degrees of freedom of the steering structure do not interfere with each other,and the steering angle can meet the requirements of the design model.The three working conditions of the obstacle-passing component are single-sided wheel obstacle-crossing,double-sided wheel obstacle-crossing and hill-climbing motion simulation meet the design model requirements,and the obstacle-crossing height can meet the design requirements.4.Trial-produced three-degree-of-freedom structure and wheel leg structure and other key components,verified and tested the structure function,and proved the correctness and feasibility of design model5.The control simulation analysis process of the overall chassis model was established,and the working status and running relationship of the wheel leg structure and the three-degree-of-freedom structure when facing different obstacle heights were obtained.PID control and closed-loop feedback were added.Simulation results with good rideIn this paper,a six-wheel forest chassis with a three-degree-of-freedom hinge structure and a luffing wheel leg structure was optimized and improved,and the chassis steering and obstacle crossing components were redesigned.The redesigned chassis can complete the design requirements,with a minimum turning radius of 3500 mm and a maximum obstacle clearance height of 432 mm.The turning radius and obstacle clearance height can meet the design requirements and meet the basic needs of China's forestry equipment,providing technical support for the development of China's forestry equipment.The application of technology to practice has promoted the development of key technologies for forestry equipment in China. |
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