全膜双垄沟播玉米穗茎兼收对行联合收获机的研制

为适应中国西北旱区玉米全膜双垄沟播种植模式,解决传统玉米收获机械收割过程不对行、玉米籽粒损失率高的问题,设计了一种自走式穗茎兼收型旱区玉米全膜双垄沟联合收获机。该机采用对行式收割割台、立式摘穗辊装置、割台下方中间位置输送玉米果穗、立式摘辊后方设置茎秆切碎装置、机身侧面输送经切碎后的玉米茎秆,实现了旱区玉米全膜双垄沟播种植的对行收割以及穗茎兼收,降低了籽粒损失。田间试验表明,在机具作业速度为3~4.5 km/h、立式摘穗辊转速为1 100 r/min、茎秆切碎装置转速为1 584 r/min时,籽粒损失率为1.8%,果穗损失率2.4%,籽粒破碎率0.77%,茎秆切碎合格率92.6%,苞叶剥净率95.1%,能够满足玉米联合收获技术要求。

Development of corn combine harvester reaping both corn ear and stalk for whole plastic film mulching on double ridges

Abstract: Corn is one of the main grain crops in China, and it is also an important part of farmers'' income source. In recent years, in order to achieve the goal of increasing agricultural maize income, corn planting areas in the middle east of Gansu have used a technology called the double-furrow sowing with whole plastic film against the drought, and it provides an effective technical approach for a steady increase in the yield of maize in arid regions. According to statistics, by the end of 2013, the rate of corn mechanical harvest was 49%, and till 2016, the rate of corn mechanical harvest reached 63% in China. On the whole, the corn mechanization level in China has been greatly improved, but the harvest of maize in Gansu Province is mainly based on artificial harvesting, and mechanized harvest has lagged behind the national average level. Except some small plots that can not use combine harvester, plastic film has become one of the main reasons limiting the application of corn combined operation machinery. If we continue to use the machine with horizontal roller commonly used in China at present for harvesting, then after stripping the collection process of corn stalk can not be completed. Therefore, the ordinary type of corn combine harvester with horizontal roller is not suitable for agricultural production in arid regions. To adapt to the cropping patterns of the whole plastic film and double-furrow sowing in arid regions, and solve the problem that the corn plant can not be fed continuously into the header of the harvester during the harvesting process, as well as the high loss rate issue of traditional corn harvester, a kind of self-propelled corn combine harvester for harvesting ear and stalk was designed in this paper. This machine cut 2 rows at one time, and used the vertical snapping rolls to grab the corn ear from the corn stalk, and the corn ear was delivered at the middle of the cutting platform; behind the vertical snapping rolls there was a shredding device, and the corn stalk chopped by the shredding device was conveyed by the conveyer on the side of the combine harvester. This arrangement on the cutting header realized whole plastic film mulching on double ridges for two-row cutting and reaping both corn ear and stalk for corn combine harvester, and grain loss was reduced. Because of the existence of plastic film, the corn stalk after picking could not be smashed and returned to the field with corn stubble. However, the vertical snapping rolls could solve this kind of defect. When the vertical snapping rolls worked, the stalk was output from the vertical snapping rolls, so it was suitable to recycle the stalk. Compared with the horizontal snapping rolls, the vertical snapping rolls can reduce the weight of the cutting platform and shorten the length of the machine. At the same time, the turning radius is reduced correspondingly, the turning is more flexible, and the machine can walk better on the double ridges. In addition, the gripping delivery mechanism adopts a holding and convey chain on one side, and the other side is an eccentric elastic tooth type shifting wheel, so the weight of the cutting platform is further reduced. And the machine can complete the function of corn ear''s picking, conveying, peeling and collecting at one time, as well as the stalks cutting, kneading, chopping, throwing and collecting. The field experimental results showed that the grain loss rate was 1.8%, the ear loss rate was 2.4%, the grain damage rate was 0.77%, the qualified rate of cutting corn stalk was 92.6%, and the husking rate of corn was 95.1%, when the machine speed was 4.5 km/h, the speed of vertical snapping rolls was 1 100 r/min, and the speed of shredding device was 1 584 r/min. And the experimental results meet the design requirements of combined operation machine.