全履带式再生稻收割机行走底盘碾压率的模拟与分析

为减少全履带式再生稻收割机收获再生稻头季时行走底盘对留桩的碾压率(履带碾压面积与收割面积的比值),以利于提高再生季水稻产量、并改善再生季稻米品质,基于履带式车辆设计理论,以割幅Z、轨距B、履带接地长度L、履带宽度b、转向半径R0、底盘中心轴线与割台割刀纵向距离X为影响因素,建立了全履带式再生稻收割机行走底盘结构模型及其田间直行转弯碾压模型,以种植行距i,株距c,穴径br的水稻为对象,对上述各参数对碾压率的影响规律进行了分析,结果表明,其他参数相同条件下,直行时,碾压率δ1随割幅Z与履带宽度b的比值增加而减小;转弯时,全履带式再生稻收割机碾压率δ2随转向角度θ增大而减小,随转向半径R0的增大而减小;碾压率不受底盘中心轴线与割台割刀纵向距离X的影响;轨距B以及割幅Z与轨距B之差为行距和株距的公倍数时有利于减少碾压率;在相同接地比压条件下,割幅Z增加有利于减少碾压率。为减少碾压率,全履带式再生稻收割机结构设计时,在满足接地比压前提下,应减少履带宽度b和接地长度L,增大割幅Z,轨距B取行距和株距的公倍数,割幅Z与轨距B之差为行距和株距的最小公倍数,采用回转式行走路径;结合田块形状与面积,优先选用较大转向半径R0;在农艺上,建议水稻种植行距与株距有整数倍关系。

Simulation and analysis of the stubble pushing rate by chassis of the completely tracked harvester for the ratoon rice

Reducing the rate of stubble pushing (Ratio between the pushed stubble area and the area of harvesting) by chassis of the completely tracked harvester in the mechanical harvest processing of the first crop of the ratoon rice can not only ensure the yield,but also improve the quality of the ratoon rice.Based on the tracked vehicles design theory,six influential factors were chosen to analyze:the width of the cutting range Z,the track gauge B,the length of the track on ground L,the width of the track b,the turning radius R0,the longitudinal distance between the central axis of chassis and cuter of cutting platform X.Both a structure model of the chassis of the completely tracked ratoon rice harvester and a stubble pushing model (going straight and turning) in the field were established.Furthermore,a rice planting model was set as follows:its planting row spacing was i,hill spacing was c,and hill diameter was br in the field.And then the influences of various parameters on the stubble pushing rate were analyzed.Under the same planting conditions and the parameters of the completely tracked harvester,the results showed that the stubble pushing rate δ1 decreased with the ratio of Z to b increased when the harvester was on straight way;while on turning way,the δ2 decreased with the turning angle θ and R0 increased.The stubble pushing rate was not affected by X.Both B and the difference between Z and B were the least common multiple between the row spacing and the hill spacing was conducive to reducing the stubble pushing rate.Under the condition of the same ground pressure,the increase of Z was beneficial to reducing the stubble pushing rate.When a completely tracked ratoon rice harvester was designed for working in a paddy field,some rules could be used for reducing the stubble pushing rate.For example,B and L should be reduced under the premise of satisfying the ground pressure;Z should be increased;B and the space between Z and B should be the least common multiple between the row spacing and the hill spacing.A rotary walking path and the preferable large turning radius R0 should also be used by combining the shape with the area of the field.Practically,the integer relation between the rice planting row spacing and the hill spacing was suggested.