| As the main food crop in China,rice needs a lot of water for its growth.Building ridges is the key to realize flooding and irrigation in paddy fields.Solid and reasonable ridges are the important guarantee for high and stable yield of rice,which can effectively save water resources and benefit the construction of standardized farmland in China.At present,most areas of our country still adopt the traditional artificial ridge construction method to build ridges.It is inefficient and can not build soild and reasonable ridges.The technology of building ridges by machine is proposed to liberate labor force and improve the quality of work to a great extent,but the current machine of building ridge can not build the ridge mechanically at the corner of the ground,and the remaining ridge of the ground still needs manual construction.In order to improve the efficiency and quality of embankment construction,reduce the intensity of work and solve the problem of mechanical embankment construction at the corner of paddy field embankment,an Bi-directional ridge building machine for paddy field with 180° horizontal rotation of rotary cutting and pressing components was designed.The working mechanism of the main components of the ridger is deeply analyzed.The rationality,functionality and operability of the embankment machine are studied by combining theoretical analysis,computer simulation and field test.The main contents of the study are as follows:(1)Design and analysis of key components in bi-directional ridger for paddy fieldAccording to the agronomic requirements of ridger for paddy field,the structure and working principle of key components of bi-directional ridger for paddy field are expounded.Three types of rotary cutting right curved knives are designed according to the requirement of embankment construction machine.Through the analysis of soil and the movement characteristics of the knives,the working parameters,structural parameters and arrangement of the knives are determined.Based on the compaction theory,the shrapnel-type pressing parts are designed,and the rolling conditions of the shrapnel-type pressing parts are obtained through the kinematic force analysis.The kinematics model of lateral displacement mechanism and 180° horizontal rotary adjusting mechanism is established.Through kinematics analysis,the structural parameters of moving parts which can meet the migration requirements under different working conditions are obtained,and the conditions that the rotary process of rotary cutting soil-collecting parts and shrapnel-type crushing parts tends to be stable are obtained.(2)Finite element and modal analysis of 180° horizontal rotary regulating mechanismFinite element simulation analysis was carried out.Static and dynamic characteristics of 180° horizontal rotary adjusting mechanism,the key component of two-way embankment machine in paddy field,were analyzed by using ANSYS workbench software.Finite el ement model of 180° horizontal rotary adjusting mechanism was established.Static characteristics of 180° horizontal rotary adjusting mechanism under three working conditions of forward,backward and rotary adjusting under full load were analyzed.The weak links and stress concentration areas of 180° horizontal rotary adjusting mechanism under various working conditions are explored;the dynamic characteristics of 180° horizontal rotary adjusting mechanism under free state are analyzed by modal analysis,and the first six natural frequencies and modes of 180° horizontal rotary adjusting mechanism are calculated to ensure that the low-order modes of 180° horizontal rotary adjusting mechanism can avoid common external excitatio n frequency norms,avoid resonance phenomenon.(3)Configuration of whole machine and test in fieldAccording to the agronomic requirements of paddy field embankment construction,the rotary cutting depth adjustment device and the walking tail wheel assembly were designed to complete the configuration of bi-directional ridger.The field operation performance test of paddy field two-way ridge construction machine was carried out.The results show that when the operation speed is 1.5,2.0 and 2.3 km/h,the average of ridge solidity increases with the increase of the interval time after ridge construction,and the coefficient of variation of ridge solidity decreases with the increase of the interval time after ridge construction;when the interval time is the same,the average of ridge side solidity is higher than the top of ridge,and each measurement of ridge is made.The position stability values are not less than 1332 k Pa.The ridges built by forward and backward operation methods meet the agronomic requirements of paddy ridge construction. |
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