Abstract: Camellia bud damage in the process of harvest by Camellia fruit picking machine is the most urgent problem. In order to reveal the theory of bud damage in mechanical picking of Camellia and to obtain the better picking parameters of dial knife, the effect between the tooth combing device and the Camellia and Camellia bud was analyzed. Firstly, the 3D model between tooth comb dial knife and Camellia fruit and bud were established in the ANSYS Workbench, the interaction between the dial knife device and Camellia and Camellia bud was simulated, simulation results showed that the critical initial velocity and the acceleration of the Camellia fruit peeling off were 5 m·s^-1 and 2 m·s^-2 respectively, and the critical initial velocity and the acceleration of Camellia bud dropping were 3 m·s^-1 and 2 m·s^-2, respectively. Secondly, the damage of Camellia bud was analyzed by the dial knife device at different initial velocity and acceleration, the maximum equivalent stress and strain of Camellia bud was slightly decreased with the increase of acceleration, the maximum strain in the X-direction of Camellia bud was slightly increased with the increase of acceleration, and the maximum strain in the two directions of Y and Z was slightly decreased with the increase of acceleration. As the dial knife thickness became 1.5 times, 2.0 times, 2.5 times and 3.0 times, the critical initial velocity of the dial knife to peeling off Camellia fruit were 3.4, 2.5, 2.0 and 1.7 m·s^-1, respectively, and the critical acceleration of peeling off Camellia fruit were 1.3, 1.0, 0.8 and 0.7 m·s^-2, respectively. The simulation results showed that with the increase thickness of the dial knife, the dial knife critical initial velocity and acceleration will be reduced, which can enhance the practicability of this machine.

Key words: Camellia fruit, dial knife, simulation analysis, damage, bud