Research On The Key Technology Of Hole Type No-tillage Machine Based On The Five Bar Mechanism

The topic selection of thesis is based on the ―National Public Welfare Industry(Agriculture) Research Projects‖(201303011). The paper makes a deep research on the key technology of hole type no-tillage machine based on the five-bar mechanism, using the methods combines theoretical analysis and innovative design,experiment and virtual simulation.Through widely consult related literature, understood the current situation of existing notillage machine domestic and foreign development,summarized the anti–blocking mechanism of various machine in the seeding process, concluded that the way to handle the straw of the existing no-tillage machine is divided into two categories: one is cutting out the straw,clear out the seeding bands, the other is remove the straw, both two ways can meet the seeding requirements, but also exist some insufficient, such as the first way has a high requirement of the working part,and adapt to the limited amount of straw,the other way can easily cause dust phenomenon when working under drought condition,and also exists the high requir ement of working part and large power consumption. As the result, clear that the direction of research is to design a notillage mechanism which does no handling to the straw residue, determined using the bunch way for no-tillage seeding.(1)Innovation on five-bar cavitation mechanismAfter analyzing the farm machine which used similar working method, obtained that trajectory is the essential condition of various machineries to guarantee work effect. Combined with operation condition the agency shall meet the requirements that the large stroke small hole mouth, then make the elliptic as the hole endpoint relative trajectory,and make its absolute path to meet the requirement by adjusting the parameters. The five-bar mechanism has different size and phase angle with more parameters, and different ways of driving and transmission ratio, can draw rich trajectory curves, so choose it as the formation of the trajectory. Using the way that five-bar mechanism drives the cavitation mechanism to make the hole, five-bar cavitation mechanism has been designed creatively. This organization both satisfies the requirement of trajectory, and can effectively overcome the existing shortages of present no-till planter in anti–blocking.(2)Five-bar mechanism parameters solutionThis paper demands five-bar mechanism parameter combination which can meet the demand that relative trajectory is elliptic,and has big effective stroke,small round buckle maximum transverse chord length in absolute trajectory, at the same time meet work requirements. Based on its structure and space constrains,determine the parameter relationship,u sing the region trajectory localization, analysis trajectory characteristic in the area,determine the trajectory characteristics to meet the requirements, using CATIA V5R21 mechanical design module, knowledge engineering module with DMU digital prototype module, to parametric modeling and simulation movement, drawing trajectory of hole endpoint under different parameters,studies the influence rule of each parameter on the trajectory,combined numerical comparison method, under the constraints of objective function and institutional space position, finally obtained the parameter combination.(3)Intermittent metering mechanism design and technology integrationAs to match the five-bar cavitation mechanism to form a complete no-till seeding apparatus, make a selection and design of the other components. Left and right brace give the five-bar mechanism support and power transmission, the intermittent metering mechanism ensures that when in the job, only when the five-bar mechanism move to the specific location, metering device put the seed, which ensures the consistency of acupuncture point and seed, to avoid that when five-bar mechanism stop work caused by a lack of motivation or structure reason, the seeds still fall down, at the same time reduces the waste of seeds.(4)Test platform establishment and experimental studyTo observe the penetration and disturbance from five-bar to straw when cavitation in different angle, design five-bar cavitation test platform which can fully embodies mechanism characteristics and can adapt to multiple factors and levels adjustment. Make the thickness and the different mulching forms of straw as the test condition, get the ability of getting through the straw and the disturbance situation of straw by change the angle between CD and the cavitation.