秸秆深埋还田机螺旋开沟装置的设计与试验

Design and Experiment of Spiral Milling Cutter Device of Straw Deep Bury and Returning Machine

秸秆深埋还田机在进行田间作业时,能否开出符合机具作业要求的深沟是秸秆深埋的关键。目前国内秸秆还田机种类繁多,但具有深埋作用的机具相对较少,东北地区常年使用小四轮拖拉机进行田间作业,犁底层逐年加厚上移,导致土壤耕层变浅,土壤肥力下降,影响了作物产量。针对这一情况,设计一种具有螺旋开沟装置的秸秆深埋还田机,探究单螺旋开沟装置和并排双螺旋开沟装置的优缺点,并通过田间试验最终确定螺旋开沟装置的主要结构配置。通过对螺旋开沟过程中土壤颗粒的运动过程分析,确定螺旋叶片的主要参数,单轴螺旋线对称布置的螺旋开沟器为变螺距螺旋,最大螺旋升角为16°,双轴并排布置的螺旋开沟器恒定螺距,螺旋升角为16°。经过理论计算分析得开沟器转速为268r·min^(-1)。为寻找最合适的开沟装置,确定螺旋装置的最优工作运动参数,以拖拉机前进速度、螺旋开沟装置转速和开沟深度为试验影响因素,以单螺旋和双螺旋的开沟深度合格率和秸秆深埋率为试验指标,设计三因素三水平正交试验。试验结果表明:当拖拉机前进速度为3km·h^(-1),开沟装置转速为270r·min^(-1),开沟深度为28cm时,安装有双螺旋开沟器的秸秆还田机开沟稳定,开沟深度合格率为99.1%,深埋秸秆的效果最好,深埋率可达91.4%。试验结果可为螺旋式秸秆深埋还田机开沟装置的选择提供理论和实践依据。

The key for burying straw deeply in the field with the straw burying machine is that it can make a deep ditch.At present,there are many types of straw machines in China,but only few have deep burying function.In the condition of using small four-wheel tractor for field operations in northeast region every year,the plough pan moves up gradually and the top soil layer becomes shallower,resulting in soil fertility declining and crop yield reduction.In view of this situation,we designed a straw deep burying machine with spiral ditching device,explored the advantages and disadvantages of single spiral ditching device and side by side double helix ditching device,and determined the main structure of the spiral ditching device configuration through the field test.Through the analysis on movement of soil particles helix ditching process,we determined the main parameters of the helical blade.The spiral opener single axis symmetrical arrangement of helices is variable pitch screw with initial helix angle of 16 degrees;the spiral furrow opener with constant pitch is biaxial with helix angle of 16 degrees.The theoretical speed of single and double shaft auger is 268 r·min-1.In order to find the most suitable ditching device and determine the optimal working parameters of spiral motion device,a three-factor and three-level orthogonal test was designed with the speed of the tractor,spiral ditching device speed and ditching depth as the experimental factors to test the ditching depth and deep burying rate of single screw and double spiral.The results showed that when the tractor the speed was 3 km·h-1,the ditching device speed was 268 r·min-1,and the planting depth was 28 cm,the ditch was 99.1%qualified with installation of straw machine ditching stable double helix furrowing opener,and the straw was buried up to 91.4%.The test results could provide theoretical and practical basis for selecting device of spiral straw deep burying machine.