双筛体多功能花生收获机设计与试验

Design and Experiment of Double Screen Multifunction Peanut Harvester

为了解决常见收获机功能单一、适应性差及振动大等问题,设计了一种双筛体多功能花生收获机,并对收获机的总体结构、工作原理及关键部件的设计与平衡进行了介绍。通过简单的挖掘试验确定挖掘铲铲面倾角为20°,根据农艺要求确定机器作业幅宽为100 cm,挖掘深度8~22 cm可调。由Adams软件分析出在驱振轴转速为240 r/min时,单筛质心点的加速度以0.27 s为周期在1.5~18 m/s2范围内变化,产生周期性变化的不平衡惯性力。根据Box-Benhnken试验设计原理进行三因素三水平试验,建立了总损失率、带土率和振动加速度关于机具前进速度、杆条筛振幅、驱振轴转速的二次回归模型。对各影响因素综合优化后得到最优参数组合为:机具前进速度1.0 m/s、杆条筛振幅48 mm、驱振轴转速240 r/min,此时总损失率为1.73%,带土率为7.32%,振动加速度为3.02 m/s2,各项指标均符合标准要求。

Aiming at the characteristics of common harvester,such as single function,poor adaptability and severe vibration,a double screen multifunction peanut harvester,4 HCDS-100 type peanut harvester,was designed based on the agricultural and agronomic requirements. This machine is not only used for peanut harvesting,but also used for the harvesting of potatoes,sweet potatoes,residual film,etc.,by replacing main screens and adjusting working parameters,it is multifunctional with high machine utilization rate. The harvester can complete the process of mining,cleaning and paving with the advantages of slight vibration and reliable operation. In this paper,the overall structure,working principle,design and balance of the key components are introduced. According to the agronomic requirements,the machine width was designed as 100 cm,and the digging depth was adjustable in the range of 8 ~ 22 cm. The vibration driving device is balanced by the eccentric block,under the action of contra-parallelogram mechanism,the fore-screen worked with back-screen on the same frequency,amplitude and reverse motion to reach self-equilibrating of vibration. Box-Benhnken method was applicated to arrange the three factors and three levels experiment of peanut harvesting,The advancing velocity,vibration amplitude of bar screen,rotational speed of vibration driving axle were taken as the influencing factors,and the total loss rate,soil containing rate and vibration acceleration were used as indexes in the experimental study. The soil type of the experimental field was sandy loam,soil water content was 12. 5 %,soil hardness was107 k Pa. The harvest object,Luhua No. 11,was planted as the pattern of One Ridge Double Line. The surface angle of digging shovel mounted on the harvester was 20 degree,and the bar screens with bar spacing of 12 mm were taken as main screens. Then built a Quadratic Regression Model of total loss rate,soil containing rate and vibration acceleration with advancing velocity,vibration amplitude of bar screen,rotational speed of vibration driving axle,according to test results. The results of verification tests showed that the relative errors of each test index between the means of 3 tests and the theoretical optimization value was less than 5 %,which demonstrated the quadratic regression model was reliable,so this model can be used to analyze and forecast the experiment results of 4 HCDS-100 type peanut harvester for peanut harvesting. The order of the main factors affecting the total loss rate was obtained ： rotational speed of vibration driving axle 〉vibration amplitude of bar screen〉 advancing velocity; The order of the main factors affecting the soil containing rate was obtained ： rotational speed of vibration driving axle 〉advancing velocity 〉vibration amplitude of bar screen;The order of the main factors affecting the vibration acceleration was obtained ： rotational speed of vibration driving axle 〉vibration amplitude of bar screen 〉advancing velocity. After the comprehensive optimization of each influencing factor,the optimal parameter combination was obtained,which was 1. 0 m · s-1 as the advancing velocity,48 mm as the vibration amplitude of bar screen,240 r· min-1 as the rotational speed of vibration driving axle,with this optimal parameter combination,the total loss rate was 1. 73 %,the soil containing rate was 7. 32 %,the vibration acceleration was 3.02 m · s-2,each index was in line with the standard requirements. This study not only provides the reference for theoretical research and optimized design of peanut harvester,but offers a new thinking for the multi-functionalization of digging harvester as well.