粳稻定向精量播种装置排种性能试验

Performance experiment of directional precision seeding device for japonica rice

为探究粳稻定向精量播种装置排种性能的影响规律并获得因素的最优组合,以东农419长粒型粳稻为播种对象,采用单因素及三因素三水平正交试验设计方法,对粳稻定向精量播种装置进行了排种性能试验研究。建立了定距输送板输送频率、输送板齿距和滑道夹角3个主要因素与排种合格率（1~3粒率）、理想排种率（2~3粒率）的数学模型,分析了各影响因素及其交互作用对排种合格率与理想排种率的影响规律,并进行了参数优化与试验验证。影响排种合格率的主次因素依次为输送板输送频率、输送板齿距和滑道夹角;确定优选组合为输送频率2.7 Hz、滑道夹角46.8°、输送板齿距9.6 mm,平均排种合格率为98.75%,经试验验证,与理论优化结果基本一致。在相同的试验条件下采用北方常用的3个长粒型粳稻和2个短粒型粳稻品种进行综合播种作业性能试验,在纸介种带喂入速度为0.04 m/s时,平均播种合格率为97.22%,平均理想排种率为77.57%,漏播率与重播率分别低于2.6%和0.4%,试验结果表明该装置对北方长粒型粳稻具有更好的适应性能,能够满足粳稻机插秧育秧播种要求。该研究为北方粳稻种子带育秧设备定向精量播种装置的优化设计与排种性能的提升提供了参考。

In order to solve the problems that the seeding rate was large, the position of dropping seeds was inaccurate and the distribution of seeds was poorly uniform on seedling trays during northern japonica rice seedlings in greenhouses, a new directional precision seeding device with combined V-shaped groove slide was developed. It could achieve that each rice seed was sedately arrayed in its long axis direction by the positioning conveying plates, which moved along the D-shaped trajectory in the V-shaped slide. This device was mainly composed of test-bed bracket, driving system, combined V-shaped groove slide, cleaning-seed brush roll, seed separating and feeding mechanism, and horizontal conveyer system. The combined V-shaped groove slide and the seed separating and feeding mechanism were key parts of the seed-metering device. The chief function of the former was to arrange the seeds in their long axis direction while the seeds moved along the combined V-shaped groove, and the latter could drive the directed seeds to move towards the exit intermittently. The working process of the device would be as follows： the rice seeds were placed in the hopper above the combined V-shaped groove slide at first, then the positioning conveying plates drove the seeds to move towards the exit intemaittently; each seed moving in the V-shaped grooves would constantly readjust its own long axis direction influenced by the action of the positioning conveying plates and the inclined plane of the grooves, which made the seed in the long axis arranged in a row along the V-shaped grooves slide, and realized the automatic orientation of the seeds. Later, the directed seeds were conveyed to the exit and located on the seed tape or seedling trays according to the required number and spacing of seed. To study the influence law of different factors on seeding performance for directional precision seeding device and obtain the optimal combination of parameters, the conveying frequency, the tooth spacing and the slide angle were taken as the main impact factors of the seeding device performance. In the self-made test-bed, the long-grain type japonica rice Dong Nong 419 was selected as experimental material, the effects of the 3 main impact factors on seeding qualified rate （1-3 seeds every turn）, ideal seeding rate （2-3 seeds every turn） were studied by single factor experiments and three-factor and three-level orthogonal experimental design, and the relationships between 3 main influencing factors and seeding qualified rate and ideal seeding rate were established respectively by regression analysis. The influence law of the factors and their interaction on seeding qualified rate and ideal seeding rate was analyzed, and the best optimized combination of the parameters was obtained. The results indicated that the order of primary and secondary factors affecting seeding qualified rate was： conveying frequency 〉 tooth spacing 〉 slide angle and that affecting ideal seeding rate was： tooth spacing 〉 conveying frequency 〉 slide angle. The optimal combination parameters were conveying frequency of 2.7 Hz, slide angle of 46.8~ and tooth spacing of 9.6 mm. Under the combination condition of the optimal parameters, the seeding qualified rate and the ideal seeding rate were 98.75% and 84.8% respectively. The seeding verification test indicated that the result fitted in well with the optimal experiments. The seeding overall performance test was carried out under the same conditions with 3 varieties of long-grain type japonica rice seeds （Dongnong 419, Longyang 16 and Daohuaxiang） and 2 varieties of short-grain type japonica rice seeds （Kongyu 131 and Longjing 26）. As the paper tape moved at the speed of 0.04 m/s, the average qualified rate and the ideal seeding rate were 97.22% and 77.57%, respectively, and all the miss-seeding rates and reseeding rates were less than 2.6% and 0.4%, respectively. Experiment results indicated that when seeding long-grain type and short-grain type japonica dee seeds, the device had a better adaptability for the long-grain type. The seeding performance could meet the requirements of precision seeding for the japonica rice. The research provides a theoretical reference for optimizing the design and improving seeding performance of the directional precision seeding device for northern japonica flee.