| The rape is one of the important oil crops in china, and the production of rape in China is the one third of production in the world. A lot of problems that the different mature degree in the same stems and the short period in harvesting result in the high lose rate for the combine harvester occur when the harvest machines are working on the field during the harvesting period, thus4SY-1.8rape windrower was designed and manufactured for solving this problems. The main components of4SY-1.8rape windrower included the reel system, the cutting device, the conveyor system, the vertical roller device, the grain divider, the transmission system, the hitching system and the frame etc. The working principles and experimental studies of main components of4SY-1.8rape windrower were analyzed to determined the structural and operational parameters, in order to obtain the conveying mechanism, the different varieties of rape were introduced to test and study in biological and mechanical characteristics; the motion process of single stem was studied to build the kinetic equations from vertical growing states to horizontal windrowing on the field; then the moving principle and motion regulation were presented; so the main influence factors and the optimal combine of parameters of4SY-1.8rape windrower were obtained by the methods of fault tree analysis, computational simulation and field experiment. The main content of the study were following:(1) According to the biological and mechanical physical characters of the rape stems,4SY-1.8rape windrower was designed to meet the requirement of harvesting rape with comparatively analyzing the conveying and windrowing devices of rice, wheat and rape, this new kind of combined stem conveyor was integrated to convey the stems in the longitudinal and transversal directions, and the overall structure and working principle were determined, while the structural and operational parameters of key components were confirmed with the reel, the cutting device, the conveyor and vertical roller etc. This integrated conveying method of rape stems in the longitudinal and transversal directions could be innovative to solve the cutting and windrowing quality on high-rough rape stems.(2) In order to improve4SY-1.8rape windrower’s adaptability to different varieties of oilseed rape, the biological and mechanical physical characters of cutting stems were tested by "Xiwang368" and "Huayouza62" in the experiments with manual direct seeding and mechanical direct-seeding respectively. The experimental results indicated that plant height, the height of stem gravity center above ground0.35m, diameter of pod canopy, number of branches would rise with the increase of diameters of stems, while the height of bottom pod and bottom branch decrease. The loading of stems would reduce from the bottom to top on the cutting stems above ground0.35m for the two rapes, while the intensity of shearing, bending and compressing increased, the shearing work increased and reduced in the stems, and the shearing work in bottom of stems was maximum, but "Huayouza62" obtained the minimum shearing work3.53J on0.15-0.25m and the minimum shearing work of "Xiwang368" was3.57J on0.25-0.35m. The mechanical and physical characteristic of results showed that the straw height was0.2-0.25times height of stems, the power consumption of cutting was minimum and could be beneficial for picking and threshing machines; this could be used for designing the windrowers to harvest the rapes on the different varieties and planting ways.(3) The fault tree method was introduced to analyze the influencing factors of windrowing quality on rape windrowers, and the FTM model was built to find the main factors including the production of rape, the height of stems, the height of gravity center on cutting stems, the height of straw, the structural and operational parameters; the bottom case was analyze in the FTM model to obtain the improvement FTM model, thus the most important factors of influencing performance were acquired with the height of stems and production, this was certificated through the field experiments. It is innovative to introduce the FTM to analyze and estimate the rape windrower.(4) The moving processes of rape stems were studied to acquire the moving mechanism of stems and the interaction of components in the conveying and windrowing processes, the order conveying and windrowing mechanism was determined; and the structural and operational parameters of windrower were introduced to built the quantization relationship model with the feed rate of reel wheel and the output of conveying device.(5) The motion regulation of single rape stems in the windrower was analyzed to build the gravity center trajectories equations and spacing curve by Matlab; the interaction between the single stems and windrower was simulated by ADAMS, the curves of trajectories, displacement, velocity and acceleration were obtained with the times; the curve of contact force between the components and stems were acquired with the time, these curves could be used for determining the motion states of stems in the moving process, this could be used to change and optimize the structure of windrower.(6) the match parameters between the sizes of discharging device and the forward speed of machines were introduced to do lots of experiments with analyzing the relationship between the spacing layout of windrowers and operational parameters on biological characters through the theoretic analysis and simulation, the results showed4SY-1.8rape windrower harvested the rapes in different heights and densities, the height rate straw and stem was0.2～0.25, the forward speed was0.6～1.1m/s, the speed rate between reel wheel and tractor was1.1～2.5, the speed rate between conveying device and tractor was2.5～3.5, the speed rate between vertical conveying device and reel wheel was1.25～2; the distribution of rape was not uniform in the manual direct seeding field, the forward speed of tractor was0.67m/s, while the forward speed could increase to0.9m/s in the mechanical direct seeding. The field experiments showed the windrower could finish the cutting, dividing, conveying and middle windrowing in one operation; it had a great windrowing quality and could be used for picking and threshing in the other operations. The parameter match between the structural parameters and operational parameters is innovative. |
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