Experimental Study On Physical And Mechanical Properties Of Garlic And Design Of Key Device Of Harvester

In order to solve the problems of long development cycle and low efficiency caused by lack of data support when designing garlic harvester.In this paper,the physical and mechanical properties of garlic at maturity were studied by mathematical statistics.The mechanical parameters such as main geometric characteristic index,stem tensile strength,radial compressive strength and pulling force of garlic were obtained.Based on this theory,the design of the key device of garlic harvester was carried out.The main research content is as follows:(1)Study on physical and mechanical properties of garlic.The physical and geometric characteristics of garlic were analyzed by mathematical statistics,the variation range and distribution frequency of the index values of the main geometric properties of garlic were obtained.The mechanical properties,such as tensile strength,compressive strength and pulling power of garlic stem during the mature stage,were tested by universal testing machine,the parameters such as tensile strength,compressive strength and pulling force of garlic stem were obtained.The effect of different stem diameter,water content and loading speed on the breaking force of garlic stem was analyzed.Based on the analysis of design-expert software,the location parameters of the excavator are obtained.The results were as follows:the height of garlic was mainly between 340 and 360 mm;The diameter of garlic stem was mainly from 11.27 to 18.20 mm;The diameter of garlic was mainly distributed between 44.36 and 84.21 mm;The height of garlic is mainly distributed in35.55~48.50 mm;The length of garlic root group was mainly distributed between 78and 86 mm;The diameter of garlic root group was mainly distributed between 88 and92 mm;The water content of stem was 82~91%;The minimum tensile strength of garlic stem was 0.66 MPa,the minimum compressive strength was 0.67 MPa,and the minimum breaking force was 53.1 N;When the mining depth is 9~13 cm and the mining distance is 8~12 cm,the required pulling force is less than 53.1 N.(2)Research and design of key device of harvester.In order to reduce the resistance in the process of garlic mining,a vibration mining device was designed.A crank rocker mechanism is used to drive the digging shovel to break the garlic root and break the soil,and the location of garlic for subsequent operation.The garlic mining device designed plane Angle of 25°;The shovel face width is 1200 mm;The operating speed is 2.5 m/s.At the same time,a flexible clamping conveyor is developed for the practical problems of high loss rate,low efficiency and high labor intensity of garlic clamping conveyor.In the process of clamping transportation,the tensioning components and clamping mechanism work together,therefore the clamping conveyor belt is s-shaped,and garlic clamping reliable and smooth operation.The designed flexible gripping delivery mechanism is 25°slope angle;The conveyor belt is type B double belt;The width is 40 mm;The clamping height is adjustable from 100 mm above the ground;The production efficiency is 0.2~0.5hm~2/h.(3)Simulation and optimization test.The optimal loose soil position of garlic was verified by EDEM simulation:The distance of loose soil is 8~12 cm;The depth of loose soil is 9~13 cm.Calculate the load of the excavating shovel at the optimal loose soil position.ANSYS was used to simulate and optimize the excavation shovel,and verify that the maximum stress of the shovel surface meets the strength requirements.