大宽幅对行施肥施药车的设计与试验

Design and Experiment of Large-width Fertilizer and Pesticide Application Vehicle for Rows

针对目前我国施肥施药机械存在作业精度差、肥药利用率低等问题,设计了一种大宽幅对行施肥施药车,通过采用幅宽拓展机构实现大宽幅作业,机具集成了3组施肥施药组件,每组施肥施药组件安装有10组施肥头与施药头,完全展开后的作业幅宽为7.5m,可同时对30行农作物进行施肥施药,停止作业后左右两侧的施肥施药组件可收拢至机身两侧,便于机具的道路行走和安放;采用对行调节机构实现施肥施药喷头与作物间的距离在0~140mm范围内可调;采用高度可调机构实现施药喷头距地高度在0.1~1.2m范围内可调,满足不同施药高度需要;基于液压技术设计了机具的液压驱动系统,机具的作业幅宽、对行距离和高度调节动作的实现均采用液压系统驱动;施药采用下倾式风送气力喷雾,利用气流提高农作物间的扰动量,提高药液的穿透力,使用Solidworks软件建立风送喷雾系统的3维模型,并利用Ansys中的Fluent模块对风送喷雾系统进行了仿真分析,计算得出最佳进气速率为0.9 kg·s-1;基于PLC设计了作业控制系统,控制模块的核心控制器采用西门子S7-200PLC,实现了机具操作的自动化控制;试制了施肥施药车样机,试验结果表明:各调节动作运行正常,各施药喷头的距出气口中心40cm处的射流核心速度均值为18.56m·s-1,标准差为0.087,气流速度分布均匀,机具设计合理。

Aiming at the problem s of poor operation precision and low utilization ratio of fertilizer and pesticide application machine in our country at present, we designed a large-width fertilizer and pesticide application vehicle for rows by using the breadth expanding mechanism to achieve wide operation. The machine installed three sets of fertilization and pesticide application components, and each set of fertilization and pesticide application components were installed with 10 sets of fertilization and pesticide applicator. The breadth of operation was 7.5 m after full extent. The fertilizer and pesticide application of 30 rows of crops could be carried out at the same time. After the operation was stopped, the fertilization and pesticide application components on the left and right sides can be contracted to both sides of the fuselage to facilitate the walking on road and placement. The distance between the applicators of fertilizer-pesticide and the crops can be adjusted in the range of 0-140 mm by using mechanisms of adjustment to row. The height adjustable mechanism was used to adjust the distance between the sprayer nozzle and the ground in the range of 0.1-1.2 m which can meet different application height requirements. The hydraulic driving system of the implement was designed based on the hydraulic technology. The operation width, the distance between the applicators of fertilizer-pesticide and the crops and the height adjustment movement of the implement are all driven by the hydraulic system. The downward inclined pneumatic spray was applied to the pesticide application using air flow to increase the disturbance between crops and improve the penetration of liquid pesticide. The 3 D model of the pesticide spray system was established by Solidworks software combined with simulated analyses by the Fluent module in ANSYS and calculated the optimum intake speed was 0.9 kg·s-1. The core controller of the control module adopted Siemens S7-200 PLC to realize the automatic control of the operation of the machine based on the operation control system of PLC. The prototype of fertilizer and pesticide application vehicle was made. The results of test showed that the adjustment movements were normal. The average velocity of the air-jet core at 40 cm from the center of the outlet was 18.56 m·s-1 and the standard deviation was 0.087. The airflow velocity was evenly distributed and the design of the machine was reasonable.