The existing moving box mechanism pot seedling transplanting machine on the market moves too fast when the picked seedling is collected,which negatively impacts the seedling picking performance.In order to improve the...The existing moving box mechanism pot seedling transplanting machine on the market moves too fast when the picked seedling is collected,which negatively impacts the seedling picking performance.In order to improve the performance,two types of variable speed continuous moving box schemes were designed in this study.The first scheme was to apply a spiral-gear moving box spiral shaft with sine curve characteristics in the box moving mechanism,whereas the second one was to change the circular gear in the moving box into an elliptical gear with a speed shifting transmission mechanism.The working mechanism of the mechanical structure was analyzed,and the kinematic model was established.A dynamic analysis of the slider mechanism was performed.A virtual prototype was established according to agronomic parameters,and the virtual prototype experiments were conducted in ADAMS.The physical prototype and the high-speed photography experiment were performed on the test bench of a transplanting machine frame.The theoretical analysis,virtual prototype and physical prototype test results were consistent,which verified the validity of the theoretical model,virtual prototype and physical prototype and ensured the feasibility of the system.展开更多
Several studies have indicated that potted vegetable seedling transplanting technology can greatly improve the ability of vegetable seedlings to resist cold,flood,drought,saline-alkali and pests.The existing transplan...Several studies have indicated that potted vegetable seedling transplanting technology can greatly improve the ability of vegetable seedlings to resist cold,flood,drought,saline-alkali and pests.The existing transplanting equipment mostly adopts mechanical,electrical and hydraulic integration technologies with a complex structure and a high cost.To address the problems of the complex structure and low efficiency of existing transplanting equipment,a rotary transplanting mechanism for potted vegetable seedlings was developed through configuration analysis and optimization design.Through kinematic analysis of the transplanting mechanism,optimization design software was developed,and the parameters were optimized.A mechanism was developed for picking,transporting,hole punching and transplanting potted vegetable seedlings.The virtual simulation results showed that the maximum error of attitudes of the transplanting arm is less than 1.19°and that of the hole punching shovel is less than 1.7°.In this study,perforation,seedling harvesting and transplanting experiments were conducted through a bench test.The results showed that the specific trajectory and attitude of the potted vegetable seedlings transplanting mechanism conformed to the requirements of potted vegetable seedling transplantation and the success rate of seedling picking was 92.4%,which verified the correctness and feasibility of the rotary potted vegetable seedling transplanting mechanism.展开更多
To realize the mechanization of flowerpot seedling transplanting,a creative mechanism to transplant flowerpot seedlings was designed.The mechanism is based on noncircular gear in combination with a transplanting arm e...To realize the mechanization of flowerpot seedling transplanting,a creative mechanism to transplant flowerpot seedlings was designed.The mechanism is based on noncircular gear in combination with a transplanting arm equipped with an extensive seedling pick-up device to transplant the flowerpot seedlings from the growing tray to the flowerpot,which in accordance with the transplanting agronomy requirements.The working principles of a theoretical model and kinematic characteristics of the transplanting mechanism were analyzed.The computer-aided analysis and optimization software based on Visual Basic 6.0 was developed and used to obtain a set of special trajectory and attitude parameters satisfying the transplanting operation requirements.The optimized parameters were used for virtual manufacturing and simulation testing of the transplanting mechanism.The virtual prototype testing results are consistent with the theoretical analysis,verifying the structural design validity and rationality.The high-speed photography was used in a bench test of the transplanting mechanism with“Salvia Splendens”pot seedlings as test samples.The trajectory and attitudes of the theoretical analysis,virtual test,and physical prototype test were essentially identical.The bench test results showed that the success rate was 91.67%for the seedling pick-up device penetrating into the root mass at 35 mm,thus,the quality of the extracting seedling was satisfactory.展开更多
With a focus on the design of tooth profiles of non-circular gears with addendum modifications that conform to the given complex transmission ratio curves and based on a series of discrete point sets on the pitch curv...With a focus on the design of tooth profiles of non-circular gears with addendum modifications that conform to the given complex transmission ratio curves and based on a series of discrete point sets on the pitch curves,the criteria for tooth profile distortion and undercut in non-circular gears were proposed.With the constraint of no tooth profile distortion and undercut,the addendum modification coefficient was introduced into the calculation of the distorted and undercut segments of the tooth profile of a non-circular gear,and the addendum modification coefficient of each contact point of the non-circular gear was obtained.Based on the generating principle for gear shaping with gear cutters,a theoretical model for calculating the tooth profile of non-circular gears with addendum modification was derived.The cutting and radial feeding motions of the pinion cutter were ignored,and only the meshing motion was considered.The involute tooth profiles of the pinion cutter enveloped the tooth profile of the non-circular gear.3D automatic non-circular gear model generation software was developed,which was a secondary development product of the software UG.A non-circular gear in a rice potted seedling transplanting mechanism was designed,and the transplanter was developed and tested.The test results showed that the designed tooth profile of non-circular gear achieved the variable transmission ratios required by the transplanting mechanism.When the transplanting efficiencies were 140 plants/min,160 plants/min and 180 plants/min,the transplanter completed the rice potted seedling transplanting operation with high quality.展开更多
基金supported by the National Key Research and Development Program of the 13th Five-year Plan(Grant No.2017YFD070802-2)the China Special Fund for Agro-Scientific Research in the Public Interest(Grant No.201203059-01)+3 种基金the National Key Technology R&D Program(Grant No.2014BAD06B-1-05)the Open Fund Projects of Zhejiang Province Planting Equipment Technology Key Laboratory(Grant No.2013E10013-06)the National Natural Science Foundation of China(Grant No.51775104)by the National Key Technology R&D Program(Grant No.2014BAD06B01-13).
文摘The existing moving box mechanism pot seedling transplanting machine on the market moves too fast when the picked seedling is collected,which negatively impacts the seedling picking performance.In order to improve the performance,two types of variable speed continuous moving box schemes were designed in this study.The first scheme was to apply a spiral-gear moving box spiral shaft with sine curve characteristics in the box moving mechanism,whereas the second one was to change the circular gear in the moving box into an elliptical gear with a speed shifting transmission mechanism.The working mechanism of the mechanical structure was analyzed,and the kinematic model was established.A dynamic analysis of the slider mechanism was performed.A virtual prototype was established according to agronomic parameters,and the virtual prototype experiments were conducted in ADAMS.The physical prototype and the high-speed photography experiment were performed on the test bench of a transplanting machine frame.The theoretical analysis,virtual prototype and physical prototype test results were consistent,which verified the validity of the theoretical model,virtual prototype and physical prototype and ensured the feasibility of the system.
基金This research was supported by the National Key Research and Development Program of China(Grant No.2017YFD070800)the Opening of Key Laboratory of Modern Agricultural Equipment Technology in Northern Cold Region(Grant No.KF18-04).
文摘Several studies have indicated that potted vegetable seedling transplanting technology can greatly improve the ability of vegetable seedlings to resist cold,flood,drought,saline-alkali and pests.The existing transplanting equipment mostly adopts mechanical,electrical and hydraulic integration technologies with a complex structure and a high cost.To address the problems of the complex structure and low efficiency of existing transplanting equipment,a rotary transplanting mechanism for potted vegetable seedlings was developed through configuration analysis and optimization design.Through kinematic analysis of the transplanting mechanism,optimization design software was developed,and the parameters were optimized.A mechanism was developed for picking,transporting,hole punching and transplanting potted vegetable seedlings.The virtual simulation results showed that the maximum error of attitudes of the transplanting arm is less than 1.19°and that of the hole punching shovel is less than 1.7°.In this study,perforation,seedling harvesting and transplanting experiments were conducted through a bench test.The results showed that the specific trajectory and attitude of the potted vegetable seedlings transplanting mechanism conformed to the requirements of potted vegetable seedling transplantation and the success rate of seedling picking was 92.4%,which verified the correctness and feasibility of the rotary potted vegetable seedling transplanting mechanism.
基金This research was supported by the National Key Research and Development Program of the 13th Five-year Plan(Grant No.2017YFD070800).
文摘To realize the mechanization of flowerpot seedling transplanting,a creative mechanism to transplant flowerpot seedlings was designed.The mechanism is based on noncircular gear in combination with a transplanting arm equipped with an extensive seedling pick-up device to transplant the flowerpot seedlings from the growing tray to the flowerpot,which in accordance with the transplanting agronomy requirements.The working principles of a theoretical model and kinematic characteristics of the transplanting mechanism were analyzed.The computer-aided analysis and optimization software based on Visual Basic 6.0 was developed and used to obtain a set of special trajectory and attitude parameters satisfying the transplanting operation requirements.The optimized parameters were used for virtual manufacturing and simulation testing of the transplanting mechanism.The virtual prototype testing results are consistent with the theoretical analysis,verifying the structural design validity and rationality.The high-speed photography was used in a bench test of the transplanting mechanism with“Salvia Splendens”pot seedlings as test samples.The trajectory and attitudes of the theoretical analysis,virtual test,and physical prototype test were essentially identical.The bench test results showed that the success rate was 91.67%for the seedling pick-up device penetrating into the root mass at 35 mm,thus,the quality of the extracting seedling was satisfactory.
基金This research was financially supported by the National Key Research and Development Program of China(Grant No.2017YFD070800)the Key Research and Development Program of Jiangsu Province(Grant No.BE2018324)and the Opening of Key Laboratory of Modern Agricultural Equipment Technology in Northern Cold Region(Grant No.KF18-04).
文摘With a focus on the design of tooth profiles of non-circular gears with addendum modifications that conform to the given complex transmission ratio curves and based on a series of discrete point sets on the pitch curves,the criteria for tooth profile distortion and undercut in non-circular gears were proposed.With the constraint of no tooth profile distortion and undercut,the addendum modification coefficient was introduced into the calculation of the distorted and undercut segments of the tooth profile of a non-circular gear,and the addendum modification coefficient of each contact point of the non-circular gear was obtained.Based on the generating principle for gear shaping with gear cutters,a theoretical model for calculating the tooth profile of non-circular gears with addendum modification was derived.The cutting and radial feeding motions of the pinion cutter were ignored,and only the meshing motion was considered.The involute tooth profiles of the pinion cutter enveloped the tooth profile of the non-circular gear.3D automatic non-circular gear model generation software was developed,which was a secondary development product of the software UG.A non-circular gear in a rice potted seedling transplanting mechanism was designed,and the transplanter was developed and tested.The test results showed that the designed tooth profile of non-circular gear achieved the variable transmission ratios required by the transplanting mechanism.When the transplanting efficiencies were 140 plants/min,160 plants/min and 180 plants/min,the transplanter completed the rice potted seedling transplanting operation with high quality.
