Design and Experiment for Flexible Clamping and Conveying Device for Green Leafy Vegetable Orderly Harvester

Abstract

Due to the advantages of improving vegetable quality and reducing labor, technology for the orderly harvesting of green leafy vegetables has always been the focus of research. The core of the technology is the clamping and conveying device. At present, technology for the orderly harvesting of green leafy vegetables has several difficult problems, such as the plugging of the clamping and conveying device, great damage caused by mechanical clamping and high transportation loss. A green leafy vegetable is essentially a viscoelastic body and plastic deformation is an important index to measure its mechanical damage. Therefore, based on vegetable linear viscoelastic characteristics, we determined the deformation and plastic damage mechanism caused by orderly clamping and conveying. A rheological constitutive model and mathematical equations of the damage deformation value were constructed for the green leafy vegetable mechanical clamping process. Viscoelastic parameters of green leafy vegetable samples were obtained by creep experiments. The elastic clamping force and clamping spacing were analyzed systematically when the flexible clamping and conveying device was clamping, conveying and collecting. Under different spring stiffness and clamping time combinations, green leafy vegetable plastic damage deformation values were calculated and the vegetable damage regularity analyzed. After comprehensive consideration, we concluded that, when the harvester forward speed was 0.6 km/h, the optimal parameter combination of the flexible clamping and conveying device was a conveying roller rotation speed of 80 r/min, and a spring stiffness combination of 2.0 N/mm and 0.6 N/mm. Finally, a bench test verified that the mechanized harvest effect was best under a combination of parameters. Thus, we proved that the method is appropriate for studying the effects of clamping and conveying devices on green leafy vegetable damage based on viscoelastic rheological characteristics.