拔取式白萝卜联合收获机研制与试验

Design and experiment of pulling white radish combine harvester

白萝卜属于根茎类蔬菜,具有生长周期短、栽培适应性强、单产高的优点,是我国重要的经济作物。根据白萝卜生长特点、种植模式和收获作业需求,研制一种拔取式联合收获机。它主要由扶樱装置、松土装置、夹拔装置、根茎分离装置和收集装置等组成,可以一次性完成松土、夹持拔取、输送、切樱和装箱收集等联合收获作业。采用锥形开口式扶樱结构设计,通过主动与欠驱动相结合的方式调节锥形开口角度,以满足种植行直线度低、垄面不平整情况下的拢樱需求;设计夹持力的柔性调节装置,可以实现白萝卜的稳定拔取和夹持输送,减少漏拔率、避免输送过程造成的茎叶掐折;进行松土铲的结构参数设计,并根据白萝卜生长环境、土壤力学特性和拔取受力特点,采用有限元法进行工作受力分析和强度校核,提高松土铲的松土性能和可靠性;设计双圆盘锯齿式根茎分离切割装置,切樱平稳、切口整齐,有效避免切樱过程中由于白萝卜果实晃动造成的切割损伤。田间联合收获性能试验表明:整机作业性能稳定,损伤率小于2.7%、漏拔率小于1.8%,收获效率为0.08~0.26 hm^(2)/h。拔取式白萝卜联合收获机的推广使用,可以有效地降低劳动强度、提高收获效率和性能,对于提升我国白萝卜机械化收获水平具有重要意义。

White radish is an important economic vegetable in China.It has the advantages of short growth cycle,strong adaptability and high yield.Based on the growth characteristics and planting patterns,a pulling white radish combine harvester is designed.The harvester is mainly composed of cherry blossom pulling device,soil ripping device,clamping device,rhizome separation device and collection devices,which can perform the combined harvesting operation including lifting,scarifying,conveying,cutting and collecting in series.In order to ensure the smooth entry of white radish stems and leaves into the gripper and avoid the stems and leaves from being pulled off,a lifter with conical opening is designed.By adjusting the conical opening angle of the lifter through active and under-actuated combination,the adaptability of the prototype is improved under the condition of low planting line straightness and uneven ridge surface.In order to realize stable flexible pulling and gripping conveying,and avoid stem and leaf fracture in the process of pulling and conveying,a flexible gripper and gripper force adjusting device is designed.The gripper belt is composed of rubber in which the antiskid pattern is printed on the working surface.According to the growth environment,soil mechanical properties and operation stress characteristics of white radish,the structural parameters of the ripper are designed.Through finite element analysis and strength check,the performance and reliability of ripper are improved.To avoid the cutting damage caused by the shaking of white radish during the cutting process,and achieve the effect of smooth cutting and neat incision,a double disc cutter is designed.The field performance tests indicate that the working performance is stable,with the damage rate of 2.7%,the missed rate of 1.8% and the efficiency of 0.08~0.26 hm^(2)/h.The popularization and application of pulling white radish combine harvester will effectively reduce labor intensity and improve harvest efficiency,which is helpful for improving the mechanization level of white radish in China.