自走式牧草青贮联合装袋机设计与试验

针对目前中国牧草收贮设备不能将盛产期的牧草切割后直接装袋而造成的运输成本高、工序多、营养损失大等问题,提出了将牧草在田间进行收割、粉碎、装袋、扎口联合作业的青贮保存方法,并设计了一种自走式牧草青贮联合装袋机。该文描述了机器的总体设计方案,并对输送粉碎装置、牧草粉碎后螺旋挤压等装置进行了设计,确定了其关键参数值。该研究进行了含水率为78%的牧草试验,机器前进的平均速度为2.3 m/s、割茬高度为5~15 mm,螺旋压缩比为2:1,临界旋转速度为99 r/min,样机能够顺利工作,装袋的密度能达到320 kg/m3,装袋平均时间为30 s每袋。机型的设计不仅能够提高劳动生产率,方便取饲喂养,而且为青贮牧草的收获存储提供了新的方法。

Design and experiment of self-propelled grass silage combined bagging machine

Abstract: Silaging nutrient-rich phase grass with bags in the field can reduce nutrient loss, maintain green feed nutrients, and facilitate long-term preservation; thus promotes the growth of good livestock. To facilitate direct storage of forage harvested in the field, one self-propelled grass silage combined bagging machine was developed.. It integrated the cutting device, a conveyor feeding device, a crushing and throwing device, vertical auger conveyor equipment, grass bagging density control device. And their key device parameters were calculated. The self-propelled grass silage combined bagging machine used disc cutter to cut grass, the blade root diameter and top diameter were 500 and 620 mm, and the critical forward speed of the machine was 17.9 km/h so that leakage could be prevented and repeat cutting could be reduced. The designed grinding hob diameter and the width were 550 and 480 mm. it's rated rotating speed was 1600 r/min and the linear velocity of the feed roller was from 2.1-17.1 m/s when the length of the cutting grass was 5-40 mm. The diameters of the front and intermediate feed roller were 300 and 260 mm, and the calculated rear feeding roller diameter was 90 mm. In order to minimize forage accumulation, the designed throwing roller diameter was 300 mm, the width was 510 mm, the angular velocity was 2 600 r/min, the leaf number was 4, and the angle of thrown pieces of angle was 20°. The displacement and velocity equations at any moment from the start. Grass compressed by screw auger before output from the silo. The compression ratio of the screw mechanism can be adjusted for achieving the desired output squeeze effect. The three different of compression ratio screw auger were designed for different types of forage, and spirals can be changed by the exchange of connecting flange. According to squeeze theory, the designed spiral inner diameter was 100 mm and screw conveyor segment pitch was 345 mm at the beginning of variable pitch segments, meanwhile the surface of screw extruder was polished and longitudinal grooves in the barrel were built for increasing the extrusion effect. The crushed forage was loose and easy to squeeze, and had a large volume gradient. Then the volume gradient became small, and pitch gradually becomes small, so rational compression ratio made compression effect better. Finally, the critical rotation speed was calculated and was 99 r/min. In the self-propelled silage harvester, this innovative design combined automatic pneumatic tying device could greatly reduce labor intensity. Working performance test of the developed prototype was conducted with forage whose moisture content is 78%. Results showed a stubble height was 5-15 mm, cutting leakage loss was 0.85%, average bagging density was 320 kg/m3, average bagging time was 30 s per bag, tying rate was 100%.With average forward speed at 2.3 m/s, operation capability of the machine can achieve 0.53-0.67 hm2/h without clogging. The presented study provides a new approach for the harvest and storage of silage grass.