关键词: 白萝卜, 拔取式, 联合收获机, 松土铲, 结构设计, 有限元法

Abstract:  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 0.08~0.26hm2/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.

Key words: white radish, pulling, combine harvester, ripper, structural design, finite element method