自走式大宗茶蓬面仿形采茶机关键装置设计与试验

Design and Experiment of Key Devices for Self-propelled Bulk Tea Canopy Surface Shaping Tea Picking Machine

摘要:

针对国内茶园地形复杂、蓬面不规整以及机械化采摘大宗茶质量差等问题，本文结合大宗茶蓬面生长特点和收获技术要求，设计了一种切割器位姿可调整的自走式仿形采茶机。确定了大宗茶仿形采收技术要求，进行了自走式大宗茶仿形采茶机总体结构设计和工作原理分析。设计了仿形采收装置、风力输送装置、传动系统和仿形控制系统，使整机在作业过程中结构更加紧凑、工作效率更加稳定。为提高仿形状态下茶鲜叶采收质量，进一步对切割器进行优化设计；通过计算机仿真和响应面试验，根据切割图中不同切割区域面积占比评价切割性能，最终确定切割器关键参数组合为前桥宽度3.44mm、刀齿高度20.63mm、刀机速比1.2；该参数组合下漏割率为3.90%，重割率为16.36%，有效降低漏割率的同时重割率也相对较低，表明参数优化有效。田间试验结果表明，仿形采收机作业性能良好，平均鲜叶完整率为85.66%，平均漏集率为1.17%，平均漏采率为0.79%，3项指标均满足采茶机作业质量行业标准。此外，作业后茶树蓬面状况良好，不影响后续茶叶生产，符合采茶机设计需求。

Abstract:

In response to the problems of complex terrain in domestic tea gardens, irregular canopy shapes, and poor quality of machine-harvested bulk tea, a self-propelled contour-following tea harvester with adjustable cutter position was designed based on the growth characteristics of bulk tea canopies and the technical requirements for harvesting. The technical requirements for contour-following bulk tea harvesting were determined, and the overall structure and working principle of the self-propelled contour-following bulk tea harvester were analyzed.The contour-following harvesting device, pneumatic conveying device, transmission system, and contour-following control system were designed to make the whole machine more compact and stable in operation. To improve the quality of fresh tea leaves harvested in contour-following mode, the cutter was further optimized. Through computer simulation and response surface experiments, the cutting performance was evaluated based on the area ratio of different cutting regions in the cutting diagram. The optimal combination of cutter parameters was determined as a front bridge width of 3.44mm, a cutter tooth height of 20.63mm, and a cutter-to-machine speed ratio of 1.2. Under this parameter combination, the missed cutting rate was 3.90%, and the over-cutting rate was 16.36%. This effectively reduced the missed cutting rate while maintaining a relatively low over-cutting rate, indicating the effectiveness of the parameter optimization. Field trials verified that the contour-following harvester had good operational performance. During the trial period, the average intact leaf rate was 85.66%, the average missed collection rate was 1.17%, and the average missed cutting rate was 0.79%. All three indicators met the industry standards for tea harvester operation quality. Additionally, the canopy condition of the tea trees after operation was good, which did not affect subsequent tea production and met the design requirements of the tea harvester.