液压驱动式圆盘耙设计与仿真试验

【目的】针对长江中下游地区土壤黏重板结、秸秆量大和土壤含水率波动大的作业情况,设计一种液压驱动式圆盘耙。【方法】分析确定圆盘耙结构和作业参数及液压驱动系统的设计,依据机组前进速度确定圆盘耙组转速;分析得出缺口圆盘耙片的运动轨迹及满足功能要求的耙片临界偏角;基于ANSYS/LS-DYNA对圆盘耙片切削土壤过程进行有限元仿真分析。【结果】圆盘耙组转速为60~168 r·min~(-1),耙片临界偏角为23°。仿真结果表明:圆盘耙片刃口切削土壤其耕作阻力呈周期性变化,随切削土壤深度的增加耕作阻力逐渐变大,后趋于稳定;对比被动圆盘耙片与液压驱动圆盘耙片作业效果,液压驱动圆盘耙片抛翻土量大,耕深稳定。田间试验表明:液压驱动式圆盘耙耕深为85~120 mm,耕深稳定性变异系数为9.6%。【结论】液压驱动圆盘耙组作业效果达到设计要求。

Design and simulation of hydraulic driven disc harrow

Objective] To design a hydraulic driven disc harrow, and to use it under the working conditions of the middle-lower Yangtze plain with sticky and sealing soil, large amount of rice straws and fluctuating soil moisture content.Method] The structure and operation parameters of the disc harrow were analyzed and the hydraulic driven system was designed. The rotary speed ranges of the hydraulic motor were determined according to the forward speed of the system. The motion trajectory of the notched disc was analyzed and the critical angle of the disc was determined. The process that the disc cutting the soil was analyzed using the finite element simulation method based on ANSYS/LS-DYNA.Result] The rotary speed of hydraulic motor ranged from 60 to 168 r·min^–1. The critical angle of the disc was 23°. The simulation results showed that the resistance of soil cutting by the disc changed periodically, increased gradually as soil depth increased and then became stable. Compared with a negative disc, the hydraulic driven notched disc could rotate more soil and its tillage depth was more stable. Field experiment showed that the tillage depth for the hydraulic driven notched disc was 85–120 mm and the coefficient of variation for stability in tillage depth was 9.6%.Conclusion] The hydraulic driven disc harrow meets the design requirements.