The Study On Fast Sampling Equipment For Farmland Soil

With the development of precise agriculture (PA), multifarious agricultural machinery is invented to adapt the needs of agricultural production. Soil sampling is an important part of Precise Agriculture and an efficient method to solve the farm fertilization problems, including unreasonable structure, low average utilization ratio of fertilizer, agricultural environment pollution. As the foundation and carrier of soil sampling, the automatic vehicle soil sampling equipment has significant theoretical and practical value.Based on the design demand of vehicle soil sampler with rapid information acquisition technology, thesis starts the research on technical characteristics of soil sampling, the automatic soil sampler based on hydraulic hammer is developed according to the detailed requirements for the soil sampling machine. Then, the core components of soil sampler are researched deeply and designed for the soil sampling status, which are comprised of hydraulic hammer, sampling tube and the supporting enhancing institutions.The main content of the paper is:The technical characteristics of soil sampling are studied deeply. Combining with the detailed demand of the soil sampling machine, the overall scheme for the project is provided. According to the detailed requirements of the system's structure and principle, the scheme of hydraulic hammer for the soil sampling machine is selected, soil sampling tube and the supporting and enhancing insititutions are analysed.Depending on the design mode of the hydraulic hammer, hydraulic hammer with no constant-pressurized chamber is developed. Used the general design theory of hydraulic hammer, the linear model expression of the kinematic parameters for the impactor are derived, which include piston system calculation formulas, flow valve system calculation formulas and the signal-flow valve hole location calculation formulas. The theory research of hydraulic hammer will be used in production development.Depending on the condition of soil sampling needs, the optimizing structure of soil sampling tube which has resisted small and pull out easy is developed and made a special heat treatment. According to the soil sampling process analysis, the hydraulic circuits for supporting and enhancing insistitutions are calculated and analysed.Finally, to prove the work performance of hydraulic and sampling tube, simulation experiments of hydraulic hammer are used to design function advantages, impact process of soil sampling tube are simulated by LS-DYNA software. The sampling efficiency quantitative analysis is acquired by the simulation results. That provides academic basis for the soil sampling equipment, which optimizes the sampling tube and hydraulic hammer.