Design and test on cam mechanism of seedling pick-up arm for vegetable transplanter for pot seedling

Abstract: It is of important science meaning and application value to study the cam mechanism used in the seedling pick-up arm of vegetable transplanter because it is the key mechanism to influence the work performance of seedling transplanting. By exploring the shortcomings and deficiencies of the existing cam mechanism used in the seedling pick-up arm, it is not difficult to find that it takes a short time to push the seedlings, which affects the success rate of pushing the seedlings, and further affects the efficiency and success rate of transplanting the vegetable seedlings. In order to solve the problem, the analytical method with the advantages of a fast solving speed and high calculating accuracy was applied to further design the current cam mechanism in the seedling pick-up arm. According to the movement requirements of the seedling pick-up and seedling-push of the vegetable transplanter and the structure dimensions of seedling pick-up arm, the mathematical model of designing the cam mechanism was built and the push movement angle of the cam was optimized by exhaustion method. Then the practical cam profile curve was designed and kinematics and pressure angle analysis of the cam mechanism was carried out by using MATLAB program. For verifying the correctness and rationality of the improved design, UG and ADMAS software were applied to a build three-dimensional model of the seeding pick-up mechanism and to carry out the virtual prototype movement simulation. After the physical prototype of the mechanism was manufactured, the self-developed test bench, high-speed digital video camera and image processing technology were used to complete a bench test. The basic consistency of the simulation results and the test results showed the improved design is correct and reasonable. At the same time, the comparison of the improved design results and the original design results shows that the improved cam mechanism can not only meet the operating requirements of the vegetable seedling transplanter, but also effectively reduce by 27.9% of the time for the pushing seedlings, which is beneficial to improving the success rate of the seedling push and work performance of vegetable seedling transplanter.