Addressing the issues of poor performance and low single-seed rate during seed filling and cleaning for corn,an air-suction roller precision dibbler was designed,and its main structure and working principle were elabo...Addressing the issues of poor performance and low single-seed rate during seed filling and cleaning for corn,an air-suction roller precision dibbler was designed,and its main structure and working principle were elaborated.Based on the structure of the seed metering disk and the tri-axial dimensions of corn seeds,an auxiliary filling type hole boss was designed with a radius of 4 mm and a thickness of 1.5 mm.A sawtooth-type seed cleaning device was also designed,with an installation angle greater than 3°and a serrated chamfer less than 62.1°.By coupling the Discrete Element Method(EDEM)with Computational Fluid Dynamics(CFD),the flow field structure and seed metering performance were simulated and analyzed,examining the movement states of the seed population and individual seeds during the processes of filling,cleaning,carrying,and initial seed dropping.The variation patterns of the internal flow field pressure and fluid velocity of the seed metering device under different negative pressures and operating speeds were studied.Through the construction of a test bench and single-factor and three-factor orthogonal experiments,along with multi-objective optimization methods,the primary and secondary factors affecting the qualification index were determined.The optimization results showed that when the flow field negative pressure was 3.52 kPa,the operating speed was 5.81 km/h,and the suction hole diameter was 4.15 mm,the qualification index of the seed metering device was 93.2%,the missed seeding index was 3.3%,and the multiple seeding index was 3.5%.An adaptability test was conducted to verify these results,revealing that the qualification index for all three varieties of corn seeds exceeded 92.4%,the missed seeding index was less than 3.7%,and the multiple seeding index was less than 3.9%,satisfying the precision seeding requirements for corn seeds.展开更多
针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分...针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分段研究,在分段节点设立瓶颈缓冲区、并联缓冲区和风险缓冲区;然后根据工位故障持续时间与物料消耗速度计算出缓冲区最优容量,得出机械式穴播器装配线在制品多点控制优化方案。通过对某企业机械式穴播器装配系统进行Flex Sim仿真,验证了方案的可行性。展开更多
基金supported by the Joint Fund for Science and Technology Research and Development Project of Henan Province of China(Grant No.242103810026)the Outstanding Youth Project of Xinjiang Production and Construction Corps(Grant No.2024DB002)the Scientific and Technological Research Project in Henan Province(Grant No.252102110357).
文摘Addressing the issues of poor performance and low single-seed rate during seed filling and cleaning for corn,an air-suction roller precision dibbler was designed,and its main structure and working principle were elaborated.Based on the structure of the seed metering disk and the tri-axial dimensions of corn seeds,an auxiliary filling type hole boss was designed with a radius of 4 mm and a thickness of 1.5 mm.A sawtooth-type seed cleaning device was also designed,with an installation angle greater than 3°and a serrated chamfer less than 62.1°.By coupling the Discrete Element Method(EDEM)with Computational Fluid Dynamics(CFD),the flow field structure and seed metering performance were simulated and analyzed,examining the movement states of the seed population and individual seeds during the processes of filling,cleaning,carrying,and initial seed dropping.The variation patterns of the internal flow field pressure and fluid velocity of the seed metering device under different negative pressures and operating speeds were studied.Through the construction of a test bench and single-factor and three-factor orthogonal experiments,along with multi-objective optimization methods,the primary and secondary factors affecting the qualification index were determined.The optimization results showed that when the flow field negative pressure was 3.52 kPa,the operating speed was 5.81 km/h,and the suction hole diameter was 4.15 mm,the qualification index of the seed metering device was 93.2%,the missed seeding index was 3.3%,and the multiple seeding index was 3.5%.An adaptability test was conducted to verify these results,revealing that the qualification index for all three varieties of corn seeds exceeded 92.4%,the missed seeding index was less than 3.7%,and the multiple seeding index was less than 3.9%,satisfying the precision seeding requirements for corn seeds.
文摘针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分段研究,在分段节点设立瓶颈缓冲区、并联缓冲区和风险缓冲区;然后根据工位故障持续时间与物料消耗速度计算出缓冲区最优容量,得出机械式穴播器装配线在制品多点控制优化方案。通过对某企业机械式穴播器装配系统进行Flex Sim仿真,验证了方案的可行性。
