履带自走式果园气爆深松施肥机研制

针对现有果园人工施肥作业劳动强度大、效率低,以及机械开沟、挖穴施肥作业翻动土壤破坏土层结构和损伤果树根系的问题,该文结合新疆及中国北方干旱区果园土壤深松和深位施肥的要求,研制了一种履带自走式果园气爆深松施肥机,解决了坚硬土层快速打穴、定量取肥排肥、高压气爆深松施肥等关键技术难题。该机采用全液压驱动履带行走方式,主要由打穴注肥装置、定量加肥装置、气爆发生装置等关键部件组成,可一次完成果树根部土层定点打穴、气爆松土和定量深位施肥等多道工序。为提高作业效率和施肥效果,以单次作业时间和肥料扩散半径为评价指标,以打穴深度、施肥插杆内径、气爆压力为影响因素,进行了二次旋转正交组合试验,通过Design-ExpertV8.0.6.1软件,建立了评价指标与各影响因素的数学回归模型,分析了显著因素对评价指标的影响,优化试验参数,确定最优参数组合为:打穴深度600 mm、施肥插杆内径30 mm、气爆压力0.6 MPa。田间验证试验结果表明:在优化参数组合下,单次作业时间为22.1 s,肥料扩散半径为413.6 mm。试验样机经新疆维吾尔自治区农牧业机械产品质量监督管理站检测,各项检测指标均达到了样机设计的技术要求。该研究成果可为果园气爆深松施肥机产品研发与改进提供技术支撑。

Development of caterpillar self-propelled orchard gas explosion subsoiling and fertilizer machine

Abstract: The existing manual excavation and fertilization in orchards are limited by intense labor and low efficiency, and the trench fertilizer machine and the insertion and fertilizer machine inevitably damage the soil surface and the root system of fruit trees due to soil turning. For these reasons, we developed a caterpillar self-propelled gas explosion insertion and fertilizer machine according to the requirement of insertion and deep fertilization in orchards in Xinjiang and other arid regions of north China. This machine solved the key technical problems of fast insertion in hard soil layer, quantitative fertilizer fetching and discharge, and high-pressure gas explosion deep fertilizer application. Based on the rationale of fertilization via high-pressure gas explosion, this machine injected high-pressure air and quantitative fertilizers into root soils simultaneously through the insertion and injection at the fertilization parts of fruit trees, and thereby realized gas explosion subsoiling and quantitative deep diffused fertilization. During the gas explosion loosening in deep soil, the fertilizers were impacted and crushed by high-pressure air flow, and diffused along the loosening fractures into the root soils. This machine adopted the full-hydraulic drive crawler walking mode and was mainly composed of an insertion fertilizer injection device, a quantitative fertilizer application device, an air explosion device, and hydraulic and pneumatic transmission systems. With a compact structure the complete machine met the space requirement for orchard operations at the row space above 2.5 m, and could finish multiple procedures at one time, including fixed-point insertion, gas explosion soil loosening, and quantitative deep fertilization at the root soils of fruit trees owing to the control flexibility and high automation. This protective soil improvement machine integrating "no-tillage, deep loosening and fertilization" could finish deep loosening alone or combine with quantitative fertilization. With the insertion and fertilizer injection device, the insertion (fertilization) depth could be controlled by the knock-in hoisting mechanism. Under the combined action of hydraulic ram suppression and the hammering device, this mechanism could fast insert in the hard tillage layer or the harden layer and shorten the insertion time, improving efficiency. Also a rotating-wheel quantitative fertilization device driven by the hydraulic ram was designed, and the single feeding volume was about 100 ml, but it could be adjusted by increasing the times of fertilization. The gas explosion device offered stable air pressure for gas explosion and deep loosening. Good effects of loosening and fertilization were obtained within the gas explosion pressure of 0.6-0.8 MPa, and the device did not damage roots. To improve the operating efficiency and fertilization effect of this machine, we conducted quadratic rotation orthogonal combination tests by using the single operation time and fertilizer diffusion radius as the evaluation indices as well as the insertion depth, fertilizer rob inner diameter and gas explosion pressure as the influencing factors. Mathematical regression models between the evaluation indices and influencing factors were built on Design-Expert V8.0.6.1, and the effects of significant influence factors on the evaluation indices were analyzed. The optimal combination of influence factors was found to be: insertion depth at 600 mm, fertilizer rob inner diameter of 30 mm and gas explosion pressure at 0.6 MPa. Field verification tests showed the single operation time and fertilizer diffusion radius under the optimal factor combination were 22.1 s and 413.6 mm respectively. We also entrusted Xinjiang Agriculture and Animal Husbandry Machinery Product Quality Supervision and Management Station to test the operational performance of this machine, which indicated this machine could work stably and efficiently, and all tested indices met the technical requirements of prototype design. This study results can provide technical support and reference for the development and modification of the gas explosion subsoiling and fertilizer machine for orchards.