4LZZ-1.0型小区稻麦联合收割机的研制及试验

Development and experiment on 4LZZ-1.0 type plot grain combine

针对中国田间育种机械化程度低、缺乏小区育种作业装备的现状,结合国内小区稻麦种植模式和农艺要求,研制出了4LZZ-1.0型小区稻麦联合收割机。对机器整体设计方案进行了描述,并对气力辅助割台装置、脱粒装置、清选装置、气力输送装置等进行了设计,确定其关键参数。该装备采用静液压轮行走装置和全喂入收获方式,可一次完成育种小区稻麦的分禾、扶禾、切割、喂入、脱粒、清选、清种、份量装袋等工序。样机田间小区收获试验表明,该样机作业性能稳定,生产率39.4小区(4.7 m×2.7 m)/h、脱净率99.97%、含杂率1.46%、破碎率0.04%、损失率1%、小区时隔50.94s、混种率0,各项性能指标均达到或超过了设计指标和相关标准。

According to the present situation of the low mechanization of field experiments and the lack of plot equipment in China, 4LZZ-1.0 type plot grain combine was developed to cope with the planting pattern and agronomic requirement of Chinese grain breeding. The grain plot combine has the functions of holding and dividing grain stems, cutting grain stems, threshing and cleaning of grain and bagging seeds. The major design was given in details. The head with air cleaning device, threshing system, cleaning system, and pneumatic transmission system were designed, and their key parameters were calculated. The equipment had hydrostatic wheel walking device with working speed of 0-0.7 m/s, and full feeding method was used in this grain plot combine. The engine power was 40 kW, and the width of head was 1500 mm to meet the requirement of plot harvest width in China. The rotary speed of the reel was 10-20 r/min, and the velocity of conveyer belt on header centre was 0.82 m/s, so that there was no blocking of grain on the head. Air flowed at a speed of 7 m/s from 2 rows of small air holes which were in two insides of the head to clean the grain seeds in the head. A CVT（continuously variable transmission） device was used to control the speed of threshing cylinder to be from 300 to 2100 r/min. The optimal parameters were obtained by means of orthogonal test, which were threshing cylinder speed of 1264 r/min, concave clearance of 14 mm and feeding rate of 1.5 kg/h. An agricultural centrifugal fan with the axial length of 800 mm was selected as the cleaning fan with a blade diameter of 210 mm. The normal fan speed was 1350 r/min for seed cleaning during harvesting, and the maximum fan speed was 2200 r/min for cleaning seeds from the machine at stopped state before harvesting the next plot. Force analysis of seed on sieve was performed and the crane speed of 310 r/min was determined to make sure appropriate vibrating parameters of sieves for cleaning grain seeds. The air flow speed of pneumatic transmission system was set as 25 m/s for the grain seeds being blown off along the pipe, and the air flowing rate was calculated to be 3134 m3/h according to the feeding rate of seeds, air flow speed and mixing ratio of seeds and air. A Venturi feeder was used to feed seeds for the pneumatic transmission system, and the sectional area ratio between spout and pipe was 1：3. The field experiment and performance results showed that this combine has achieved a stable performance. The main performance indices tested were as follows： the productivity was 39.4 plots（4.7 m × 2.7 m）/h, the threshing rate was 99.97%, the dirt percentage was 1.46%, the loss rate was 1%, the time interval between 2 plots was 50.94 s, and the seeds mixture rate was 0. Each of the performance indices has reached or exceeded the designed technical specifications. It is concluded that the plot grain combine is suitable for harvesting grain crops like wheat in the breeding plot, with the superiorities such as high productivity, low loss rate and no seed mixture in different plots. This study has been of benefit to improving the efficiency and precision of plant field experiments.