Development of the 4GDZ-132 sugarcane chopper combine harvester

Abstract: Sugarcane is one of the most important crops for sugar products in China. But the manual cutting and harvesting cannot fully meet the modern mechanization level of sugarcane production in recent years. For instance, the availability of sugarcane machines was only 3.28% over the pressing season in 2019-2020. Two types of sugarcane harvesters are commonly used: the whole stalk and chopper. The mainstream mode can be the sugarcane chopper harvester with a high operation efficiency suitable for the lodging sugarcane. The reason is that the sugarcane bending and collapse often occurred after the typhoons in the planting areas of Guangdong and Guangxi Province in south China. The broken and serious lodging sugarcane can easily induce the blockage of the delivery channel, high trash content, and loss rate during operation in the sugarcane field. Therefore, it is necessary to develop a sugarcane chopper combine harvester with a new delivery channel structure for serious lodging of sugarcane in the field during operation. In this study, a new type of sugarcane harvester was designed with a chopper drum centrally-mounted to a two-stage delivery channel. The delivery channel of the machine was also adopted for the short path straw and scraper screen billet. A double extractor system was composed of the middle and rear extractor fan, in order to realize the joint operations of sugarcane rooting, feeding, conveying, cutting, air separation trash removal, conveying, and unloading. The structural parameters were then calculated to determine, such as the installation angle and width of the whole stalk delivery channel, the diameter of the feeding and conveying roller, the outside diameter of the chopper drum, the height of the scraper in the billet delivery channel, and the position of the extractor fan. The operation parameters were also optimized, such as the speed of the feeding roller, conveying roller, chopper drum, and extractor fan. Finally, the prototype was developed for the 4GDZ-132 sugarcane chopper harvester. The field test showed that all performance indexes were better than before when the operation speed and extractor fan speed were 2 km/h and 1 100 r/min, respectively. Specifically, an optimal combination was achieved, where the trash content, the total loss rate, the qualified rate of the stalk, the qualified rate of cutting height, and the broken rate of ratoons were 4.42%, 3.08%, 92.10%, 96.20%, and 9.60%, respectively. More importantly, the trash content and the total loss rate of the new sugarcane harvester were reduced by 5.58 and 3.92, 1.78 and 5.12, 2.08 and 1.92 percentage points, respectively, compared with the previous 4GZ-91, the Austoft 8000 and the 4GZQ-180 types sugarcane harvester. There was no blockage in the whole stalk delivery channel during the test, indicating the better performance of the machine and the moving parts. Since the central extractor fan slightly discharged some trash, such as soil, cane leaves, and cane top, there were no stuck trash in the scraper plate of the billet delivery channel. Furthermore, there was no channel blockage in the prototype, when harvesting the seriously lodging sugarcane. The better indexes fully met the performance requirements in the standard of a sugarcane combine harvester (JB/T 6275-2019). The finding can provide a strong reference to the development of sugarcane harvesting equipment in modern agriculture.