履带式再生稻收割机底盘的设计与试验

发布时间：2018-08-30 07:35

【摘要】：再生稻是在收获时割取其稻株穗头和茎秆,留下1/3稻桩和地下根系,让其抽穗二次成熟的一季水稻。再生稻能够提高稻田单位面积的产量,增加农民经济收入,故近年来在中国水稻种植区得到广泛推广。但由于再生稻头季收割有低碾压、高留茬及湿泥脚田作业等农艺要求,现有水稻收割机技术难以满足,致使其推广受到限制。针对上述研究背景及再生稻收获要求,本文以减少底盘对留茬碾压率及增强再生稻收割机田间通过性为目的,基于履带式车辆设计理论,设计了一台全履带式再生稻收割机底盘,并对其进行性能试验及功率测试,主要研究内容及成果如下:(1)全履带式再生稻收割机碾压率计算分析。基于履带式车辆设计理论,以割幅Z、轨距B、履带接地长度L、履带宽度b、转向半径R0、底盘中心轴线与割台割刀纵向距离X为影响因素,建立了全履带式再生稻收割机行走底盘结构模型及其田间直行转弯碾压模型,以种植行距i、株距c、穴径br的水稻为对象,对上述各参数对碾压率的影响规律进行了分析,结果表明:其他参数相同条件下,直行时,碾压率δ1与随割幅Z与履带宽度b的比值增加而减小;转弯时,全履带式再生稻收割机碾压率δ2随转向角度θ增大而减小,随转向半径R0的增大而减小;碾压率不受底盘中心轴线与割台割刀纵向距离X的影响;轨距B以及割幅Z与轨距B之差为行距和株距的公倍数时有利于减少碾压率;在相同接地比压条件下,割幅Z增加有利于减少碾压率。为减少碾压率,全履带式再生稻收割机结构设计时,在满足接地比压前提下,应减少履带宽度b和接地长度L,增大割幅Z,轨距B取行距和株距的公倍数,割幅Z与轨距B之差为行距和株距的最小公倍数,采用回转式行走路径;结合田块形状与面积,优先选用较大转向半径R0;在农艺上,建议水稻种植行距与株距有整数倍关系。该研究为全履带式再生稻收割机行走底盘的设计与田间行走方案的确定提供了参考依据。(2)全履带式再生稻收割机机动性能分析。对全履带式机车行驶原理进行分析,并分析其行驶速度与履带式行走装置参数及运动参数之间的关系;其次,对全履带式机车转向原理、转向力学及转向条件进行分析;最后,对全履带式机车越沟过坎能力进行分析。该分析研究结论能对全履带式再生稻收割机底盘行走装置设计提供依据。(3)全履带式再生稻收割机底盘总体设计。基于碾压率分析及全履带式底盘机动性能分析结果,以履带式车辆设计理论及机械设计理论为基础,结合再生稻收获作业田间作业环境与特点,以Pro/E、CAD等软件为工具,对履带式再生稻收割机底盘行走系,操纵系、传动系进行设计,并加工试制样机。(4)全履带式再生稻收割机底盘测试平台搭建。本文基于扭矩传感器建立功率测试平台。在电源提供方面,该测试平台以12V直流电瓶为电源,并以12-220V逆变器将12V直流电变为220V交流电,用以为扭矩功率仪提供电力,扭矩功率仪外供电压给扭矩传感器供电。在测试方法方面,该测试平台由扭矩功率仪将扭矩与转速信号传递给扭矩功率仪,扭矩功率仪实时显示扭矩、功率及转速值,并将该值通过M400数据采集软件传递给计算机保存。所采取的测试方法能较为准确地获取全履带式再生稻收割机底盘平稳运行时的功率数据,测试方案能直接获取驱动履带底盘所需驱动功率。(5)选取水泥地面及田间对全履带式再生稻收割机底盘进行性能试验。主要为水泥地面上测试行驶速度及直行偏驶率,田间测试以不同速度及不同质量为影响因素下的底盘行驶功耗,并测试其转向功耗及转向角速度。试验结果显示:1)水泥地面上测试不同档位下实际最高行驶速度分别为Ⅰ档1.120m/s、Ⅱ档1.403m/s、Ⅲ档1.957m/s,且均小于理论最高行驶速度;水泥路面上测试其直行偏驶率为4.93%,小于国标GB/T 15370.4—2012《农业拖拉机通用技术条件第4部分:履带拖拉机》中规定的6%。2)在平均土壤坚实度为383kPa(深度150mm),平均土壤湿基含水率为25.98%(深度100-150mm)的田间进行试验。测试底盘质量一定(2200kg),不同速度水平(0.6、0.8和1.0m/s)下的直行功耗;测试直行速度一定(1m/s),不同质量水平(1400kg、1600kg、1800kg、2000kg和2200kg)下直行功率;测试底盘质量为2200kg,行走初速度为田间最高工作速度1m/s时的转向功率及转向角速度。得出结论如下:全履带式再生稻收割机底盘直行功耗随行驶速度及整机质量的增大而增大;在底盘质量为2200kg,行驶初速度为1m/s条件下转向功耗为13.63kw,转向角速度为0.486rad/s,转向载荷比为1.63。
[Abstract]:Recycled rice is a kind of crop rice which is harvested at the time of harvesting, leaving 1/3 of the rice stump and underground roots, allowing it to mature twice before heading. The existing rice harvester technology is difficult to meet the agronomic requirements such as high stubble retention and wet mud foot field operation, which limits its popularization. In view of the above research background and the harvesting requirements of ratoon rice, this paper designs a tracked vehicle design theory based on the purpose of reducing the stubble retention rate of chassis and enhancing the field trafficability of the ratoon rice harvester. The main research contents and results are as follows: (1) Compression rate calculation and analysis of full crawler type rice harvester. Based on the design theory of crawler type vehicle, with cutting amplitude Z, track distance B, track grounding length L, track bandwidth b, steering radius R0, center axis and center axis of chassis, track grounding length L, track width B, track grounding length R0 and steering radius R0. The structure model of traveling chassis of full crawler type ratoon rice harvester and its direct turning and rolling model in the field were established. The effects of the above parameters on the rolling rate of rice with row spacing i, plant spacing C and hole diameter BR were analyzed. Rolling rate delta 1 decreases with the increase of the ratio of cutting width Z to track width B. Rolling rate delta 2 decreases with the increase of turning angle theta and turning radius R0 when turning. Rolling rate is not affected by the center axis of chassis and the longitudinal distance X between cutting edge Z and track distance B. When the difference is a common multiple of row spacing and plant spacing, it is advantageous to reduce the rolling rate; under the same ground specific pressure, the increase of cutting width Z is advantageous to reduce the rolling rate. The common multiple of plant spacing, the difference between cutting width Z and rail spacing B is the least common multiple of row spacing and plant spacing, and the rotary walking path is adopted; the larger turning radius R0 is preferred according to the shape and area of the field; and the integer multiple relationship between row spacing and plant spacing is suggested in agriculture. This study is the design of the walking chassis of the full crawler type rator rice harvester. (2) Analysis of the maneuverability performance of the full crawler type rice harvester. Analysis of the running principle of the full crawler type locomotive, and analysis of the relationship between the running speed and the parameters of the crawler type walking device and the movement parameters. Secondly, the steering principle, the steering mechanics and the steering strip of the full crawler type locomotive. Finally, the ability of full crawler locomotive to cross ditches and ridges is analyzed. The analysis results can provide a basis for the design of chassis traveling device of full crawler type rice harvester. (3) Overall design of chassis of full crawler type rice harvester. Based on the vehicle design theory and mechanical design theory, combined with the working environment and characteristics of Ratooning Rice harvesting, the chassis traveling system, control system and transmission system of tracked ratooning rice harvester were designed with Pro/E and CAD software, and the prototype was processed. (4) The chassis testing platform of full tracked rator was built. A power test platform based on torque transducer is established in this paper. In power supply, the test platform is powered by 12V DC battery and converted from 12V DC to 220V AC by 12-220V inverter, which is used to supply power for torque power meter and external voltage of torque power meter to supply power for torque transducer. The torque and rotational speed signals are transmitted to the torque power meter by the torque power meter. The torque power meter displays the values of torque, power and rotational speed in real time, and the values are saved by the computer through the M400 data acquisition software. (5) Select cement ground and field to test the performance of the chassis of full crawler type rice harvester. Mainly test the running speed and straight deflection rate on cement ground, field test the chassis power consumption under different speed and different quality as the influencing factors, and The test results show that: 1) The actual maximum driving speed at different gears is 1.120 m/s in the first gear, 1.403 m/s in the second gear and 1.957 m/s in the third gear, respectively, which is less than the theoretical maximum speed. The direct driving deviation rate on the cement pavement is 4.93%, less than the national standard GB/T 15370.4-2012 < agriculture Tractor General Technical Conditions Part 4: Tractor > 6%. 2) Field tests were carried out with an average soil solidity of 383 kPa (depth of 150 mm) and an average soil moisture content of 25.98% (depth of 100-150 mm). Straight power consumption was measured at different speed levels (0.6, 0.8 and 1.0 m/s) and chassis mass of 2200 kg. Under certain (1m/s), different quality levels (1400kg, 1600kg, 1800kg, 2000kg and 2200kg), the direct power consumption of chassis of full crawler type ratoon rice harvester increases with the running speed and the whole machine quality, and the steering power and angular speed when the chassis mass is 220kg and the initial walking speed is the highest working speed in the field is 1m/s. The steering power consumption is 13.63 kw, the steering angular velocity is 0.486 rad/s and the steering load ratio is 1.63 under the condition of the chassis mass is 2200 kg and the initial speed is 1 m/s.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S225.4

【参考文献】