履带式三七收获机底盘转弯机理与性能试验

Turning Mechanism and Performance Testing of Crawler Chassis for Panax notoginseng Harvester

摘要:

针对现有履带式三七收获机行驶在丘陵山地时转弯机理不清、行驶稳定性差等问题，探究履带式三七收获机底盘在丘陵山地黏重土壤环境下的转弯机理与田间转向性能，结合丘陵山区中药材三七种植实际情况，对履带式三七收获机底盘转弯半径、沉陷量、土壤阻力以及滑移率等性能进行分析。首先，阐述履带底盘转弯基本原理，对同向差速转向、单边制动转向、反向差速转向3种不同转向工况进行理论分析；其次，对履带底盘沉陷量、滑移率、滑转率、行驶阻力、转弯半径等进行理论计算；同时，使用RecurDyn对履带式车辆底盘3种不同工况下转弯半径、沉陷量、土壤阻力进行仿真研究。仿真结果表明：履带底盘在转弯时受力明显大于直线行驶受力，履带板总受力随速度增大而减小，沉陷量无明显变化。最后，通过田间试验对履带底盘实际转弯半径、滑移率、沉陷量进行测量。试验结果表明：履带底盘在硬质路面最小转弯半径为1010mm，在硬质土壤最小转弯半径为1150mm，在松软土壤最小转弯半径为1360mm，试验结果与仿真结果大致吻合。研究结果可为履带式底盘运载装备结构和参数优化奠定基础。

Abstract:

For the existing crawler type Panax notoginseng harvester, when operating on hilly-mountainous terrain its turning mechanism is unclear and running stability is poor. The turning mechanics and infield steering performance of the crawler chassis in a hilly-mountainous, heavy clay soil environment were investigated. In view of the actual Panax notoginseng cultivation conditions in such regions, chassis performance metrics were analyzed, including turning radius, sinkage, soil resistance, and slip ratio. Firstly, the basic principles of crawler chassis turning were presented, and three steering modes, the same direction differential steering, single side braking steering, and counter direction (reverse) differential steering, were analyzed theoretically. Nextly, theoretical calculations were carried out for chassis sinkage, slip ratio, spin to slip ratio, tractive resistance, and turning radius. Concurrently, RecurDyn simulations were conducted under the three steering conditions to evaluate turning radius, sinkage, and soil resistance. Simulation results indicated that the forces on the crawler chassis during turning were significantly greater than those during straight line travel;the total force on the track plates were decreased as forward speed was increased, while sinkage remained essentially unchanged. Finally, field trials measured the actual turning radius, slip ratio, and sinkage of the crawler chassis. Test results showed that the minimum turning radius was 1010mm on a hard paved surface, 1150mm on compacted soil, and 1360mm on loose soil;these experimental values closely matched the simulation predictions. This research can lay a foundation for the structural and parameter optimization of crawler chassis transport machinery.