四橡胶履带轮式车辆转向力学性能分析与试验

Mechanics properties analysis and test of four rubber tracked assembly vehicle steering system

橡胶履带轮是一种能够与轮胎整体快速互换,降低接地比压、提升越野机动能力的特殊行走装置。该文以某型四橡胶履带轮式车辆转向系统为研究对象,首先通过建立断开式转向梯形机构数学模型,得到内轮、外轮转角与油缸位移关系,以及转角特性曲线;通过转向油压测试,得到两轮和四轮转向时转向油缸输出最大转向驱动力及其随左前轮转向角变化曲线。然后对履带轮在混凝土地面上转向受力分析,建立最大平均转向阻力矩数学模型,得到单轮最大平均转向阻力矩。最后提出了基于转向杆件应力应变测试分析转向阻力矩的方法,得到履带轮在混凝土地面2轮和4轮原地转向时转向阻力矩随转角变化的规律,对比分析最大总转向驱动力矩与总转向阻力矩,验证了数学模型和该分析方法的正确性。该文的研究也可对四履带轮式车辆转向系统的结构参数设计和履带轮的接地尺寸、接地比压、轮系布置研究提供参考。

Rubber tracked assembly is a special walking device which can overall swap with the tire quickly, reduced ground pressure and enhanced off-road ability of wheeled vehicles. In this paper, a divided steering linkage mechanism of four-rubber tracked vehicle steering system was studied. First, through the mathematical model of divided steering linkage mechanism to obtain the relationship between internal, external steering angle, and displacement of the hydro-cylinder, then steering angle characteristics curves can be drawn when two and four tracks turning. The internal steering angle was 50°, and the external steering angle was 38°. By testing the oil pressure of steering system, maximum steering driving force output by the steering hydro-cylinder was obtained. By establishing the maximum steering driving torque mathematical model, the trend of the maximum steering driving moment change with steering angle of the left front track was obtained. When two tracks turning, the initial steering driving moment of the front axle were the same, which was reduced with the growth of the left front track steering angle, and the steering driving moment of internal decreased faster. When four tracks turning, the steering driving moment of rear axle was significantly smaller than the front axle, and the initial steering driving moment of front and rear axle were the same, which was reduced with the growth of the left front track steering angle. Then, the force of tracks on the cement hard ground was analyzed, and the mathematical model of the maximum average steering resistance moment was then established. Finally, a method based on the stress and strain test of the steering bar to analyze the steering resistance moment was proposed, which helped to obtain the change law of the steering resistance torque when the rubber tracked assembly turned on the concrete ground. When the front axle was turned left to the end, the steering resistance moment of the right front track was advanced with the growth of the rotation angle, and then decreases gradually. The steering resistance moment of the left front track was always increases, but the total steering driving moment remained stable. When the front axle was turned back to the middle position, the resistance moments of two tracks were continued the state and values. The steering resistance moment of the left front track was greater than that the right front track at the beginning. Finally, the value of the two tracks was consistent and stable, and the closed loop was formed. Through two tracks and four tracks steering test, at the maximum angle of the left front track, the overall steering resistance moment and maximum total steering driving moment reached to equilibrium state, which verified the mathematical model of the steering system, the maximum average steering resistance moment and based on the stress and strain test of the steering bar analysis of steering resistance moment method was correct. In this paper, we provided reference to the structural parameters design of four rubber tracked assembly vehicle, also helped study on the rubber tracked assembly ground pressure and wheels arrangement.