基于EDEM的链铲式捡石机设计与试验

Design and Experiment of Chain Shovel Stone Picker Based on EDEM

摘要:

为解决捡石机捡石率低、壅土的问题,设计了一种链铲式捡石机。通过对入土铲板的受力分析,确定其结构参数;对拨石轴拨土和拨石过程进行运动学分析,明确拨石齿的运动轨迹及关键结构参数;通过EDEM确定了拨石轴对壅土区域的拨土作用以及拨出至输送链的速度。为评估捡石机的工作可靠性及作业效果,采用响应面法设计试验,考察前进速度、拨石轴转速和离地高度对捡石率与壅土高度的影响,并建立回归模型进行参数优化。试验结果表明,最优参数组合为:前进速度0.844m/s,拨石轴转速338.9r/min,离地高度394.26mm,此时模型预测捡石率93.85%、壅土高度250.57mm。通过田间试验验证,捡石率和壅土高度相对误差分别为2.97%、4.73%,捡石率和壅土高度相对误差均小于5% ,证明样机设计合理,满足捡石机作业要求。

Abstract:

Aiming to address the issues of low stone-picking rate and soil accumulation in stone pickers, a chain-and-scoop type stone picker was designed. Through force analysis of the soil-entering scoop plate, its structural parameters were determined. Kinematic analysis of the soil-shifting and stone-picking processes of the stone-picking shaft was conducted to clarify the motion trajectory of the stone-picking teeth and the key structural parameters. The action of the stone-picking shaft on disturbing the soil accumulation area and the velocity of stones thrown onto the conveyor chain were determined by using EDEM software. To evaluate the operational reliability and performance of the stone picker, response surface methodology was employed to design experiments investigating the effects of forward speed, rotational speed of the stone-picking shaft, and ground clearance on the stone-picking rate and soil accumulation height. A regression model was established for parameter optimization. The experimental results indicated that the optimal parameter combination was a forward speed of 0.844m/s, a stone- picking shaft rotational speed of 338.9r/min, and a ground clearance of 394.26 mm. Under these conditions, the model predicted a stone-picking rate of 93.85% and a soil accumulation height of 250.57 mm. Field validation tests showed relative errors between the measured values and the model predictions were 2.97% and 4.73% , respectively, both below 5%. This confirmed that the prototype design was reasonable and met the operational requirements of a stone picker.