Design and Analysis of Pneumatic Downforce Regulating Device for No-Till Corn Planter

Abstract

To avoid the issues of undesired soil compaction and seeding depth variation caused by the downforce fluctuation of the corn no-till planter, the influence of the structural parameters of the air spring on the downforce was researched in this paper, by establishing the gas–solid coupling simulation model of the air spring. The downforce test bench was built to verify the simulation model; the test showed that the vertical output force error of the simulation model was 4.79%, the pitch diameter error was 0.76%, and the pressure error was 5.07%. The cord angle, piston angle and piston diameter were used as influencing factors to carry out single-factor experiments. The influences of structural parameters on downforce were analyzed from four aspects: the vertical output force, the vertical stiffness, the pressure difference and the deformation rate. The results showed that the cord angle reduced the effective area and its change rate during deformation by limiting the radial deformation of the bellow. When the cord angles were 30°, 45° and 60°, the deformation rates were 65.6%, 20.3% and 4.8%, respectively. The cord angle had a positive effect on the vertical output force when the cord angle was in the range of 30~56°, and it had a negative impact in the range of 56~60°. As the cord angle increased, the vertical stiffness decreased. As the piston angle increased, the effective area of the air spring decreased, and the change in internal pressure decreased, reducing its vertical output force and stiffness. The piston diameter had little effect on the internal pressure and deformation rate. It increased the vertical output force and stiffness by increasing the effective area. The structural parameters of the air spring had a significant impact on the stability of the downforce; the structure of the air spring should be optimized according to the downforce demand of the corn no-till planter.

An Adjustable Pneumatic Planter with Reduced Source Vibration for Better Precision in Field Seeding

“…The upper two bars of the parallelogram system have been provided with seven steps to change the spring tension. A downforce higher than 600 N is required to achieve better uniformity in depth [ 27 ]; the dead weight of the hinged row unit and spring tension force must reach this value. The dead weight of the hinged part of a row unit is 382.32 N and the remaining force of 217.68 N is required to be supplied by spring tension.…”

Design and experiment of the pneumatic pressure control device for no-till planter

“…The ABAQUS finite element simulation has been widely used to simulate and analyze the mechanical characteristics of air springs in high-speed trains, buses, and heavy trucks, and its modeling effectiveness and accuracy have been verified many times [25,26] . Meanwhile, before the research of this article, the vertical force, pitch diameter, and internal pressure of the simulation model and the physical model have been verified in detail in the previous research [27] .…”

Research Progress on the Development of the Planter Unit for Furrowing Control and the Depth Measurement Technology

“…Zhou et al designed an active adjustment system for sowing depth based on air springs and Flex sensors, which reduced the error by 40% compared with passive adjustment [60]. In order to reduce the influence of downforce on furrowing depth, Cao et al identified the critical parameters of the air spring that had a significant influence on the downforce according to gas-solid coupling simulation and optimized the key parameters to improve the stability of the furrowing depth of pneumatic active profiling adjusting device [61]. The pneumatic-driven downforce adjustment device has the advantages of better adaptability and lightweight.…”