【作者】 ABDALLA NOURELDIN OSMAN KHEIRY；

【导师】 张东兴；

【作者基本信息】 中国农业大学 ， 农业机械化工程， 2014， 博士

【摘要】 农用机械对表层土壤的不断翻耕会产生坚硬的犁底层。深松机具的使用可以打破犁底层,使水分和植物的根系能到更深的土壤中。但深松机具需要很大的牵引力和大马力拖拉机来带动,严重地制约了深松技术的发展。振动深松是减少耕作阻力的一项新技术。现有的振动深松机大部分深松铲尖需要同一时间穿透坚硬的土壤,从而引起了土壤阻力的提高,增加了牵引力。常见的振动深松机在田间作业时,拖拉机手还会因为振动深松机的振动传递到拖拉机上而感到不适。本论文的研究为解决上述存在的问题,设计了一种新型的V型交错振动深松施肥机,优化改进深松铲来穿透土壤并克服阻力,同时使振动深松机在工作时保持平衡和振动稳定来为拖拉机手提供好的工作环境。新设计的振动深松机主要包括五个部分,(1)交错往复运动单元(2)动力提供转化装置(3)偏心结构单元(4)主机架(5)深度控制机构和施肥系统。2012年和2013年连续两年在中国河北省固安县进行测试。主要研究内容和样机的性能结果如下：-通过铲柄模型分析、铲柄受力分析以及研究铲柄阻力下降的机理,得到了相应的设计参数。计算得出振动方程式并绘制铲柄运动轨迹,确定速度、振幅、频率以及实际运动轨迹的关系,便于优化和改进。-为了研究振动频率和拖拉机前进速度之间的优化组合,对其数学设计参数在MATLAB上进行分析,结果发现：振动频率为9Hz,前进速度2km/h时；振动频率为12Hz,速度为3km/h或4km/h时；振动频率15Hz,速度为3km/和4km/h时可有效降低牵引阻力,提高松土效果。-田间拉力试验结果表明,振动和不振动深松两种工作方式的牵引阻力差别显著,前进速度从速度1增加到速度3时,振动和非振动的牵引力分别为11.6-13.5kN和14.1-15.4kN,牵引阻力都随着前进速度的增加而增加。振动情况下,在速度1、速度2、速度3下所需的总功耗分别为8.94kW、10.85kw和10.12kw。比相应速度下非振动所需要的功耗分别大8.05%、2.3%和8.4%。-土壤平均含水率受到不同的深松铲工作方式以及不同前进速度的影响,振动深松比不振动深松在速度1,速度2,速度3下分别大13%,11.3%和10.8%。滑移率在振动深松方式下比不振动方式具有显著的降低。-土壤坚实度(CPR)在不同土壤深度下受到深松铲工作方式的显著影响。土壤坚实度在深度为0-10cm处有显著的影响,不振动深松比振动深松坚实度大28.6%；在另外两个深度下具有极其显著的差别,振动深松比不振动深松土壤坚实度分别低43.49%,37.86%。不振动深松铲和振动深松铲在不同深度处对土壤容重的改变表现出显著性差异,三层深度下分别减少7.3%、14.59%和7.69%。更多还原

【Abstract】 The problems of soil compaction and hardpan formation are common in fields that were cultivated annually due to the traffic of tractors during cultivation and trucks after harvesting. Subsoilers have been developed to penetrate and break up the hardpan; but these subsoil implements faced big enemy which is require large horsepower tractors to pull the tools through the soil and the most of developing countries are used the medium size tractors therefore seriously hampered the development of technology of subsoiling.The use of vibrating or oscillating subsoiler is one technique that can reduce the draft force. different vibratory subsoiler which are sited previous, it found that, the one row tines arrangement is most common type, and these types of plow faced soil penetration resistance due to all tines of plow will penetrate the hard soil at the same time cause increasing soil resistance, consequently, increasing draft force and power consumption. Moreover; most common of vibratory plow when they tested in the field indicated that the tractor vibrations were not comfortable to the operator due to vibration power from the implement was transferred to the tractor operator seat.To solve the existing picblems, a new type of a staggered reciprocal vibratory subsoiler was designed and developed to optimize the penetration resistance and high draft forces and to keep the vibration stability during the work on the field which leads to a good working environment for the operators, also to make the plow has ability to work in different working modes and different working width with different distance between shanks and different number of shank with different vibration styles. The new designed is consist of mainly five parts,(ⅰ) the staggered reciprocating motion unit (ⅱ) generator mechanism,(ⅲ) eccentric structure unit,(ⅳ) main frame,(ⅴ) depth control mechanism and fertilizer system. The implement was tested and evaluated in mid of China Hebei province Guan city in consecutive of a year2012and2013using the different shanks working mode under different three forward speeds. The main research contents and the performance of the prototype showed that:Analyzing the model of solid-shank model, the forcing of shank and researching mechanism of resistance reduction, provided the design parameters. Calculated vibration equation and drew the trajectory path of shank, established contact with velocity, amplitude, frequency and real vibration, convenient for design and optimization.In order to research an optimum combination among the vibration frequency and forward tractor speed the mathematical design parameters was run out in MATLAB and result found that, with oscillating frequency of9Hz with forward speed2km/h,12Hz with speed of3km/h, frequency of15Hz with speed of3km/and speed of4km/h with15Hz the tractive resistance is low and the effect of loosening the soil is good.Result of draft showed that there are a significant different between two shank working modes. The ratio of draft during oscillating and non-oscillating was ranging from11.6to13.5and14.1 to15.4as forward speeds increased from spl to sp3respectively. Total power required for oscillating operation was8.94,10.85and10.12kW at forward speeds of spl, sp2and sp3respectively. It was slightly greater than the power required for non-oscillating operation. Compare the new designs draft and power requirement results to previous results of the developed1SZ-460it found that the new design recorded less by3.61%for the draft than the1SZ-460.The average of effective field capacity was statistically affected by different shanks working mode and different forward speed which it was greater in vibrating shank by13%,11.3%and10.8%as compared with non-vibrated shank for spl, sp2and sp3respectively. Wheel slippage was found significantly (P<0.05) better in Vibrating mode than non-vibrated mode, the mean wheel slippage in vibrating style was found significantly higher by11.65%,20.11%and20.6%for sp1, sp2and sp3respectively. Moreover, based on average cutting width it was found that the vibrating mode recorded43.8%and23.3%more than non-vibrating shanks for the new design and1SZ-460vibratory plow respectively.Cone penetration resistance (CPR) was greatly significantly influenced by the tow shanks working modes at different soil depth. The CPR had significant difference among the treatments at the soil depth of0-10cm and found28.6%higher in non-vibrated shank than vibrated, moreover in the two lower depths it was found that there is a highly significant difference better in vibrated mode compare to non-vibrated mode which it was43.49%and37.86%higher than non-vibrated. The influence of forward speed on CPR had no significant difference and was found almost similar.A significant difference was found between non-vibrated shank (NVS) and vibrating shank (VS) at the different depth in term of bulk density. were, it was reduced by7.3%for the first depth,14.59%for the second depth and by7.69%for last depth, furthermore soil bulk density were decreased after all tillage treatments compared with those before tillage by25.7%for the new design and by18.98%for the1SZ-460.The soil moisture in no-vibrating shank compared with the vibrated shank was similar at all depth layers of the plowed soil which there is no significant different (P<0.05). Also the results indicated that, there is very slight different in moisture content between tilled soils and perior tilled.更多还原