ASABE Technical Library - Abstract

Abstract. The aim of this study is to determine the optimum structural and operating parameters of a ear-picking and stalk-chopping combined mechanism for corn harvest. Completely randomized experiments with four ear-picking-plate edge types (small circular arc, big circular arc, rectangular chamfering and small cylindrical), three kinds of distances between rollers (6,8 and 10mm), three kinds of mounting angles of corn header (15,20 and 25°) and four operating speed(450, 600, 750 and 900r/min) were conducted. Indices of ear injury, grain damage and grain loss were measured. Results showed that the ear-picking-plate edge type of small cylindrical , the distance between rollers of 8mm, the corn header mounting angles of 15 ° and operating speed of 750 r/min were the optimum structural and operating parameters. Under that condition, the best working performance can be obtained and the harvest loss is only 0.5%. Variance analysis revealed that the total experimental treatments had no significant difference at confidence level of 0.95 and the harvest loss was less than 1.5% under each treatment (better than national standards≤5%), which means the new mechanism has good adaptability. Compared with the performance of roller ear-picking mechanism, the ear injury rate and the harvest loss of the new mechanism decreased 17% and 1.7%, respectively. At the same time, the index of qualified length of straw chopped by the mechanism reached to 87%.