Design and Study of a Spindle-Shaped Fry Head-to-Tail Orientation Device

The head-to-tail orientation of spindle-shaped fry is an important part of automated vaccine injection. The fry’s automatic orientation helps reduce labor and improve efficiency during the automated injection. This paper designed an electromagnetic vibration fry orientation device for grass carp fry, measured its friction characteristics with three different materials in scales and against scales, analyzed the kinematic characteristics of the fry on the electromagnetic vibration feeder, and clarified the main factors affecting fry transport. It used the trough’s inclination angle, amplitude, and material as the test factors, whereas the orientation success rate and orientation rate were used as the evaluation index. Orthogonal combination tests were carried out with 90–150 mm grass carp fry as the research object to obtain reasonable parameter combinations. The results showed that the best orientation effect was achieved when the surface of the trough was a silicone film with many bumps, the inclination of the plate spring was β = 15°, the inclination of the trough plane was θy = −4°, and the amplitude A = 0.7 mm. In this parameter combination, the directional device was tested and verified. The targeted success rate was ε = 95.5%, and the direction rate was η = 0.87 tail/s. The device could meet the requirements of the head and tails during the mechanized injection of the fry.