拱棚双插架覆膜一体机的设计与试验

为适应部分地区蔬菜水果拱棚种植模式,解决传统小拱棚手工搭建劳动强度大且效率低的问题,该研究设计了一款小拱棚单列双插架覆膜一体机,主要由自动进杆装置、双插架装置、覆膜装置及行进装置组成,设定插架间距与插架数量等工作参数,小拱棚单列双插架覆膜一体机实现自动进杆、双插架和覆膜一体化作业。以进杆成功率和进杆时间为衡量自动进杆作业指标,以拨轮半径、杆槽高度、顺杆板长度为试验因素,对进杆过程中的棚杆受力和运动状态进行分析和计算,确定试验因素的范围,并进行仿真试验确定最佳进杆装置结构参数。田间试验表明:小拱棚单列双插架覆膜一体机以最大速度1.2 km/h作业时,进杆成功率为94.1%,插架成功率为89.3%,拱棚覆膜率为100%,薄膜破损率为1.1%,平均插架间距为1 190 mm,平均插架宽度为1 050 mm,平均插架深度为200 mm,两侧插架深度平均偏差为30 mm,平均覆土厚度为80 m。小拱棚单列双插架覆膜一体机可实现小拱棚搭建的机械化和自动化作业,满足小拱棚插架覆膜要求。

Design and experiment of single-row double cuttage and film covering multi-functional machine for low tunnels

Abstract: Low tunnels are ever increasingly used in vegetable cultivation and seedling production in modern agriculture. The construction area of low tunnels was up to 1.3 million hectares in China. A typical low tunnel is 2 to 3 feet high and covers the width of a growing bed. However, most low tunnels were built manually, indicating high labor intensity with low efficiency. In this study, a novel machine was designed to combine the double-cottage and film covering for vegetable and fruit planting in low tunnels. The machine is mainly composed of automatic shed-pole feeding, double-cottage, and cover film device. As such, the shed poles were automatically inserted, according to the set distance between the shed poles. Specifically, the pole was made of glass fiber reinforced plastic (GFRP),where the length and diameter were 2000 mm and 7.5 mm, respectively. The automatic shed-pole feeding device included a motor, a frame of shed pole, dial wheel, limit ring, and tilt board. The double-cottage device consisted of a hydraulic transmission, arm bending, crank slide, shed-pole cottage, and variable distance adjustment board. The motor of the automatic shed-pole feeding device was used to push the shed poles to the arm bending in the variable distance double-cottage device. The reasonable design of the dial wheel and rod frame was the key issue to ensure the feed of a single rod at a time. The success rate and the time of feeding shed poles were chosen as the indicators to evaluate the performance of the automatic shed-pole feeding device. Theoretical calculation and simulation were conducted, where the main variables were the radius of the dial wheel, the height of the pole groove, and the length of the tilt board. An optimized combination was achieved, where the radius of the dial wheel was 75 mm, the height of the pole groove was 6 mm, and the length of the title plate was 150 mm. Finally, afield test was carried out to verify at an operating speed of 1.2 km/h. Optimal performance of the machine was achieved, where the success rate of shed-pole feeding was 94.1%, while the rate of shed-pole insertion was 98.6%, and the overall success rate of building shed-pole scaffolding was 89.3%, the film coverage rate of low tunnels was 100%, and the breakage rate of film was 1.1%. In insertion, the average width and depth were1050 mm and 200 mm, respectively, while the average separating distance was 1190 mm, and the average deviation of depth on both sides was 30 mm, and the average thickness of soil covering was 80 mm. Therefore, the double-cottage machine with variable distance was expected to automatically implement the intelligent operation of low tunnel construction. High efficiency and stability were also obtained to reduce manual operation and cost investment. The finding can provide a sound reference for automated smart construction of arched sheds, further promoting the facility of horticulture.