Development Of Crawler Self-propelled High-efficiency And Low-damage Hydraulic Lotus Root Harvester

Lotus root is a kind of aquatic vegetable which is easy to grow and difficult to harvest.At present,the most commonly used harvesting method is to rely on manual harvesting.This method has high operation intensity and low efficiency.In addition to the reduction of rural labor force,lotus root harvesting has become a key problem hindering the development of lotus root industry.At present,the mechanized harvesting level of lotus root is low,the related mechanical research is not mature,and the mechanical equipment has not been widely used.In view of the above problems,a crawler self-propelled hydraulic lotus root harvester with high efficiency and low damage is designed based on the principle of hydraulic lotus root harvester with crawler as walking device to realize high efficiency and low damage lotus root harvester.According to the design technical index,the whole structure of lotus root harvester is designed,the composition of each system is analyzed,the main components are selected and calculated,the internal flow field of water separator and the effective impact range diameter of nozzle are simulated by simulation software,and the performance of lotus root harvester is tested.The main contents of this paper are as follows:(1)Through on-the-spot investigation to understand the planting environment and soil characteristics of lotus root in the Yellow River Delta,the physical characteristics of lotus root were obtained by consulting the literature,which provided a theoretical basis for the design of lotus root harvester.(2)The overall design scheme of lotus root harvester is put forward,the functional objective and working principle of the whole machine are defined,and the hydraulic system,hydraulic transmission system,control system,power system and crawler self-propelled system are analyzed.(3)The pump is selected reasonably,the pressure loss of the whole pipeline is analyzed and calculated,and the actual head of the pump is 22.04 m.The hydraulic system is designed and the transmission route is analyzed.The control system with Mitsubishi PLC as the core is determined,the electrical control diagram is drawn,and the wiring between electrical components is carried out according to the drawings.The diesel engine is determined as the power source of the whole machine,the diesel engine model is selected,and the power take-off device and belt drive device are designed.The main types and structures of the track are analyzed,and the main structural parameters of the track are calculated.(4)Fluent software is used to simulate and analyze the internal flow field of the water separator,and the pressure and velocity on three sections are analyzed.The maximum and minimum values of the pressure and velocity at the water outlet of the water separator are obtained.The water outlet performance of the water separator is good,and the structure design is reasonable.At the same time,with the help of the software,the submerged impinging jet with 100 mm target distance is simulated,the pressure variation of the impinging target distance section is analyzed,and the effective impinging width of a single nozzle is determined.With the help of MATLAB software,the trajectory of the nozzle is analyzed,and the optimal scheme of the combination of the forward speed of the lotus root harvester and the swing speed of the nozzle is found,so as to avoid the phenomenon of re mining and missed mining.(5)The performance test of lotus root harvester was carried out on the hard cement ground to test the speed of each gear of lotus root harvester,so as to provide options for the transition and operation speed of lotus root harvester;the straight-line walking test was carried out to test the straight-line walking ability of lotus root harvester;the turning test was carried out to test the mobility of lotus root harvester;the climbing test was carried out to test the transition operation ability of lotus root harvester.The field test of lotus root picking was carried out in Huanghekou town of Dongying City.The machine worked normally in three lotus root fields.The test showed that the net picking rate of lotus root was 97.3% and the damage rate of lotus root was 3.4% when the machine worked in the stable lotus root field at the bottom.The test effect was good and the machine met the design requirements.