电控锥盘式蔬菜播种机设计与试验

Design and Experiment of Electric Control Cone Type Vegetable Seeder

针对蔬菜机械化播种成本高、播种质量有待提高等问题,考虑蔬菜种子尺寸小、播种株距小、播深浅等特点,设计了电控锥盘式蔬菜播种机。重点研究分析了播种机的播种原理、种子的运动特性、开沟器的受力及刃口曲线等,确定了锥盘排种器、供种器、开沟覆土器等关键部件结构及参数。通过设计闭环控制系统实现了排种盘转速与机具前进速度的匹配;采用供种器连续供种、锥盘排种器均匀排种、推种器滚轮推种的方式,解决了种子堵塞、损伤等问题;通过滑刀刃口及覆土板受力分析,确定了开沟及覆土稳定的开沟覆土器结构。大葱、白菜及菠菜的播种试验表明:该机结构紧凑、性能稳定,漏播指数小于5%,重播指数小于5%,播种合格指数大于90%,符合国家标准且满足蔬菜种植的农艺要求。

In view of the high cost of vegetable mechanized sowing and the problem that the sowing quality needs to be improved,an electric control cone disc vegetable planter was developed based on the characteristics of small size of vegetable seeds,small spacing of sowing plants and shallow sowing depth.The seeding principle and seed movement process of the metering device,the force and edge curve of the opener were studied,and the structure of the key components such as the cone disc metering device and the opener were determined. The machine was mainly composed of chassis,frame,seed metering device,closed-loop control system,trencher and pressing wheel. Through the closed-loop control system,the speed of seed metering plate and the forward speed of the machine were matched. With the help of the electric control system,the machine can control the sowing speed in real time to ensure the precision and quality of sowing;with the way of continuous seed supply,cone disc seed separation and rolling wheel seed pushing,it can ensure the quantity and precision of sowing;with the help of the construction of the slide knife curve and the stress analysis of the covering mechanism,it can realize the low resistance ditch opening and covering the soil on the ground. The force and movement of seed in the process of seed arrangement were analyzed, and the conditions of seed movement and smooth seed filling were determined. The height of cone h was 55 mm,the base angle θ was 30°,the width W of seed groove ring was 2. 5 mm,the depth T1 was 2 mm,the radius of hole was 1. 25 mm,and the number of holes Z2 was28. The key structure and motion parameters of the seed pusher were determined by the seed metering process and the matching relationship of the seed pusher structure. The diameter of the roller was 25 mm,the radian was 0. 8 rad,and the structure size was the same. Based on the analysis of seed characteristics and seed quantity requirements, the primary and normal seed quantity of the seed feeder were determined. The effective length of the seed wheel groove lgwas 9 mm. The problems of seed blocking and damage were solved by means of continuous seed supply,cone plate seed arrangement and rolling wheel seed pushing,and the resistance of trench opening was reduced by means of sliding knife and covering soil on the ground. According to the requirements of trenching and covering soil,the edge of exponential curve and covering soil mechanism were determined to simplify the structure and improve the performance. The angle of penetration α was 120°. With spinach,leek and cabbage as the representative vegetable seeds,the experiment of sowing different types of seeds was carried out. The test results showed that the machine had high sowing quality and stable performance. The qualified index was more than90%,the replaying index was less than 5%,and the missed sowing index was less than 5%,which met the national standard and the agricultural requirements of vegetable planting in the field. The research results provided a technology,equipment and method for mechanized precision planting of vegetables.