Development and experiment of rape windrower transportation device with poke finger conveyor chain

Abstract: The rape plant area is the largest in oil-bearing crops in China, and accounts for a quarter of the total rape plant population in the world. However, the uneven maturity of this rape limits the development of rape harvest mechanization. Rape partition harvest technology is composed of windrowing technology and collecting threshing technology. The rape plant is cut in the first stage, maturity. Maturity consistency and plant type are not important in the rape windrowing operation. It has the advantage of strong adaptability and a long harvest time. So rape partition harvest technology has an extensive market foreground and utility value. Windrowing technology is a difficulty in rape partition harvest technology. How to solve the problems of windrowing and transportation are the main and most difficult points in the process of designing a windrower. Focusing on the problem of windrowing and transporting in rape windrowing, a rape windrower with a vertical cutter, level cutter, machine frame, poke finger conveyor chain, driveline component, interface component, and reel device was designed. This machine was hitched with a combine chassis with functions of cutting, transporting, and windrowing. A transportation device was composed of 4 strips on a rotation poke finger conveyor chain; the poke finger conveyor chain was installed in chains. The poke finger was articulated on the chain, so it could stick out and retract while controlled by a guide in locked position. Rape plant on the transportation device was transported to an outlet by the exsertion poke finger, It was windrowed in the field when the poke finger was retracted in the outlet. The requirements of the outlet structure design were given in this paper. Based on analysis of the action process of reel and rape plants, parameters of expression of level and vertical distance between reel and cutter were established, and correlation between the installation angle of the transportation part and push angle of the reel was given. The level distance between the reel and cutter was determined by the rape growth density. As the value of 500mm for reel radius, 1-1.2 for λ, level distance between reel and cutter could be adjusted from 0 to 276mm. In this machine, the distance was 140mm，and it could be adjusted to 120mm or 160mm. The level distance between the transportation device's front end and the cutter was determined by the rape plant height. It was generally less than 300mm. The height of the reel center was more than 1100mm.It could be adjusted by a hydraulic mechanism. The vertical distance between the transportation device's front end and the cutter was less than 125 mm, otherwise the accumulation rape plant on the cutter would be transported. The assemble angle of the transportation device was from 10°to 20o. The angle which was too large or too small was unfavorable to rape plant windrowing. The poke finger movement locus equation, force analysis of rape plants on the conveyor chain, and structure design requirements of the outlet were given. The correlation between windrow quality and speed, the transporting device parameter, and windrow factor was given. The ratio of the reel pad peripheral speed and machine moving speed should be chosen in the range of 1.1-1.5. The ratio of the conveyor belt speed and the machine moving speed should be chosen in the range of 3.2-5.0.The results of a field test showed that the rape windrower worked stably and well. Rape characteristics in the experiment were listed as follows: plant height 172.1 cm, main stem diameter 14.7mm, first branch number 10, first branch height 20.7cm, the largest canopy diameter 121.1cm, the largest canopy height 130.2cm, productivity per plant 50.98g, yield 2170kg/hm2, stem moisture content 65.8%, and grain moisture content 21.3%.The checked indexes were listed as follows: cutting width 1.80m, cutting height 0.19 m, windrowing height 0.86m, windrowing width 1.83m, windrowing angle ≤32°, windrowing angle difference ≤25°, loss percent ≤0.8%, working speed 0.65 m/s, and productivity 0.5 hm2/h. All the checking indexes reached or exceeded the design technical requirements.