切流式花生全喂入联合收获机清选机构设计

针对切流式花生全喂入联合收获机清选环节果杂分离不清、损失率高、缠膜挂秧、筛面堵塞等难题,该文设计了一种风筛组合、无阻滞、大小杂并除的清选机构,其主要由上层筛(杆筛)、下层筛(多阶弹性筛和后筛)、抖草轮、偏心套、风机等组成。该文运用动态静力学方法研究了筛面物料的相对运动,分析了物料相对筛面上滑、下滑、从筛面跃起的极限条件,确定了振动筛主要运动参数的理论值域;运用达朗伯原理开展了交变载荷下筛体的受力分析,确定了筛体关键结构参数。该文对影响清选作业质量主要因素开展了试验研究,试验结果表明:影响清选机构综合作业质量的主次作用因素为主风机转速、振动筛振幅、振动频率,较优参数组合为主风机转速2 100 r/min、振动筛振幅12.5 mm、振动频率9Hz,此时清选损失率5.03%、荚果含杂率5.39%;清选机构作业顺畅性较好,较少出现缠膜挂秧、筛面堵塞现象。研究结论可为切流式花生全喂入联合收获机清选机构的设计提供理论参考。

Design of cleaning device of tangential flow and whole-feed peanut combine harvester

Grain cleaning is the core technology of peanut harvest. Therefore, in the process of peanut harvesting, how to enhance operation fluency and efficiency, and to ensure technical indicators such as low loss rate of cleaning, low impurity rate of peanut pods, has been a difficult technical problem of whole-feed peanut combine harvester. In order to settle the above difficulties, a cleaning device of tangential flow and whole-feed peanut combine harvester was designed, realizing the grain winnowed combined with screened, one-time large and small sundries clearance, sieve surface unencumbered. The cleaning device of tangential flow and whole-feed peanut combine harvester consisted of pole sieve, multi-stage elastic sieve, behind sieve, straw-shaking wheel, eccentric sleeve, main fan, auxiliary fan. The vibrating sieve consisted of pole sieve, multi-stage elastic sieve, behind sieve. Pole sieve was above the vibrating sieve. Multi-stage elastic sieve and behind sieve were below the vibrating sieve. Combined with existed mechanism advantages, a crank-rocker mechanism which consisted of the vibrating sieve and swinging arm was brought forward. In the application of cleaning device of tangential flow and whole-feed peanut combine harvester, there are many problems such as high impurity rate of peanut pods, high loss rate of cleaning, agricultural film tangles, and debris blockage. Utilizing kineto-statics method, in this paper, we researched relative motion of grain on the sieve surface, analyzed limiting conditions of grain upglide, downglide, jump from sieve surface, and determined the key motion parameter in theory. Vibration acceleration of vibrating sieve was 17.5-24.5 m/s2. Amplitude of vibrating sieve was 7.5-17.5 mm. Vibration frequency of vibrating sieve was 5-9 Hz. Utilizing D''Alembert''s principle, in this paper, we also researched sieve force under alternating loads, determined the important structure parameter of sieve. Cleaning device was matched onto the whole-feed combine and a lot of tests were carried out in the field. Loss rate of cleaning and impurity rate of peanut pods were taken as the evaluation indicator of cleaning quality. The key factors affecting cleaning quality were researched by field experiment in this paper. A scheme of orthogonal test, which included 3 factors and 3 levels, was designed. That key factor included amplitude, vibration frequency and revolving speed of main fan. The value range of amplitude and vibration frequency was based on the preceding theoretical analysis. The value range of revolving speed of main fan was based on single factor experiment. The experimental results showed that significant order for multi-factors affected on cleaning quality was: revolving speed of main fan, amplitude, vibration frequency. Within the scope of the 95% confidence coefficient, revolving speed of main fan was extremely significant for cleaning quality, amplitude and vibration frequency were significant for cleaning quality. The optimal parameter combination was that revolving speed of main fan was 2 100 r/min, amplitude was 12.5 mm, vibration frequency was 9 Hz. Under the above optimal parameters, field experiments were carried out, loss rate of cleaning was 5.03% and impurity rate of peanut pods was 5.39%. The operation of cleaning device is fluent, almost no agricultural film tangles and debris blockage. The research results provide theoretical basis for design and parameter optimization of whole-feed peanut combine harvester and cleaning device.