Improved Design And Experiment Of Rapeseed Seeder With Film Mulching And Perforating

Rapeseed in China is mainly planted with winter rapeseed and spring rapeseed.Drought and low-temperature and cold injury are important factors for the yield reduction of spring rapeseed.Film mulching and seeding of rapeseed can effectively improve the conditions of crop growth,have the advantages of storing water and increasing soil temperature of soil,and have a significant yield-increasing effect.Based on the agronomic specifications for spring rapeseed cultivation,using film-laying and sowing techniques,this paper improves and designs a rapeseed seeder with film mulching and perforating which includes a rotary tillage device,a trenching and seeding device,an adjustable film planting device,a rolling film cutting and drilling device,and a film side soil covering device to solve the practical problems of initial product such as adhesion of film hole,poor seeding uniformity due to the high position of seeder,soil covering on the membrane side is uneven,and inability to complete membrane laying when the wind is strong due to the high position of the membrane laying device.The work of this paper is as following:(1)The structure of the rapeseed seeder with film mulching and perforating was improved and designed.and its key parameters were analyzed and determined.Based on systematic analysis of domestic and foreign film-laying technology and sowing with film-drilling technology and equipment and combing with the agronomic requirements of rapeseed film-laying and sowing,this paper had been improved and designed and analysed the structure of rapeseed seeder with film mulching and perforating.The configuration and operational variables of the apparatus have been ascertained.The operational procedure of fertilizing and rotary tillage and trenching and sowing and covering soil with film and cutting film to form holes were described.At the same time,the seed metering system of the whole machine is designed and analyzed.The nest hole wheel metering device had been engineered to function as the seed metering component of the machine.(1)The study identified the diameter of the seed metering wheel to be 60mm,ascertained the shape of the apertures to be hemispherical,determined the diameter of each aperture to be 5mm,and designed the number of shaped holes to be 12.Through the mechanical analysis of the seed filling link,the seed filling angle was obtained to be 80°,and the seed feeding angle is designed to be 0°by analyzing the movement speed of the seed feeding point.(2)Using the mean value,standard deviation,and coefficient of variation of hole spacing as evaluation indicators,the bench test determined that the optimal seed delivery height of the pit eye wheel metering device is 60 mm.(3)It was determined that the power of the seed metering system is provided by a rolling film cutting and drilling device.Through the analysis of the drilling and seeding process,it was determined that the installation distance between the two is 460 mm.(2)The design and parameter analysis of the key devices of the rapeseed seeder with film mulching and perforating were carried out.It includes:(1)The arrangement of the trenching seeding apparatus was ascertained,and a sliding knife trencher was developed with a parabolic edge curve,taking into consideration the seed delivery characteristics of the nest hole wheel metering device.The edge angle of trencher was determined to be 45°,the width of the trencher is determined to be 40 mm,the length of the trencher is 160 mm,and the angle of front side plate is determined to be 60°.(2)According to the width of plastic film,an adjustable film-laying device with a film-hanging frame and a film-spreading roller was designed.The design principle of the adjustable film spreading device was analyzed,and its working principle was described.The length of the film hanging rod was 2300mm,and the outer diameter of the film hanging rod was 32mm.Through mechanical analysis,the diameter of the film spreading roller was 60mm,and the length was 2100mm.(3)Based on the sliding cutting principle,a rolling film cutting and perforating device was developed,its structure is determined,and the film breaking and perforating process of the perforating device was described.The diameter and width of the perforating roller was 250 mm and 80 mm,and the position of minimum sliding cutting angle is analyzed during the movement of the film cutting knife.The longitudinal blade length is determined to be 30～40 mm.The longitudinal blade height was 30～35 mm.The transverse blade width is 30 mm.And the transverse blade height is 25 mm.The kinematic model of the punching device was established.The factors affecting the film hole length were analyzed and determined to be the length of the longitudinal blade and the height of the longitudinal blade and the radius of the punching drum.The length of the profiling rod of the profiling machine mechanism was determined to be 320mm.(4)A membrane side soil covering device was designed,which is composed of a membrane pressing mechanism and a soil covering mechanism.It was determined that the diameter of the membrane side pressing wheel is 200mm,the width is 50mm,and the disc diameter of the soil covering mechanism is 300mm.Through the calculation of the soil covering amount,it was determined that the main factors affecting the soil covering performance are the disc diameter,the overall forward speed,the disc deflection angle and the disc penetration depth.(3)The simulation analysis of the key components of the rapeseed seeder with film mulching and perforating was carried out.(1)Based on EDEM-Recur Dyn coupling simulation,A simulation study was conducted to model the operational procedure of a cutting and punching device for rolling film.The investigation aimed to identify the most favorable set of parameters for optimal performance.The effects of machine forward speed,longitudinal blade length,and longitudinal blade height on film cutting and hole forming performance were investigated.The study employed a three-factor and three-level regression orthogonal design to conduct an experiment,and developed a mathematical model that correlates the membrane hole length and hole pitch difference with the influencing factors by using the membrane hole length and hole pitch difference as evaluation indicators,and analyzed the significance of each factor.The optimal parameter configuration was derived through the utilization of Design Expert 10.0.7.And the results of the optimal parameter configuration analysis revealed that the most effective combination consisted of a longitudinal blade with a length of 34 mm and a height of 31mm,and a forward speed of 3.3 km/h for the machine.Using the optimal parameter combination,the simulation verification test is conducted.The results show that and the film hole length is 44.78 mm and the hole pitch difference is 0.64 mm.(2)A single-factor simulation experiment was conducted utilizing the EDEM discrete element simulation software to assess soil cover performance.The evaluation indicators used were soil cover amount and operating resistance.The results of the experiment showed that optimal soil cover amount ranged between 7.63 kg/m and 8.8 kg/m,and operating resistance was less than 87.47 N when the disk deflection angle was between 30°～50°and the soil cover depth was set between 20 mm and 40 mm.The results indicated that the soil cover performance is good.A comprehensive orthogonal test was performed,employing the depth of penetration of the covering disc,the deflection angle of the disc,and the forward speed of machine as experimental factors.The covering amount and the working resistance were used as the evaluation indicators for the test.The optimal working parameters of the covering mechanism were established as follows:a depth of penetration of 30 mm for the covering disc,a deflection angle of 30°for the disc,and a forward speed of 3 km/h.Through simulation and verification tests,it is found that the covering amount of the covering mechanism is 7.71kg/m and the working resistance is 48.17N under these parameters.The operation performance of the soil covering mechanism is better.(4)The field validation test of the rolling film cutting and punching device and the performance test of the film side soil covering device and the field test of the entire machine are carried out.A rolling film cutting and hole forming device is trial-manufactured based on the optimal parameter combinations obtained from previous simulation tests.And performance verification tests are conducted.The experimental results shows that the average membrane pore length is 43.15 mm and the coefficient of variation of membrane pore length stability is 3.86%.The average hole spacing difference is-1.32mm and the film hole spacing error is 4.22%.It verifies the accuracy of the simulation test results that the relevant parameter indicators are basically consistent with the simulation test,.It can meet the requirements for film hole spacing and length in rapeseed film mulching and sowing.(2)Based on the optimized parameters of the soil covering mechanism simulation,a performance test of the film side soil covering device is conducted.The test results showed that after the completion of the operation of the film side soil covering device.The soil covering thickness on both sides of the film was between 3.7cm and 5.9 cm,and the soil covering width on both sides of the film was between 7.5cm and 9.8 cm,which meet the relevant requirements of the film covering industry.A field experiment was conducted on a complete machine,and the test results showed that the qualified rate of covering soil with acceptable covering thickness and width is 91.7%,and the sowing amount of rapeseed was3.69 kg/hm~2.It indicated that the rapeseed seeder with film mulching and perforating met the requirements of spring rapeseed film mulching and sowing.