摘要： 为了解决活鱼分级过程中存在的损伤多、效率低的问题，提出一种回转式的活鱼分级装置改进方案，以齿轮齿条机构提升分级闸门的方式代替凸轮机构和弹簧回位机构转动分级挡板的方式，可降低制造成本和故障发生率。建立其三维模型并给出关键部件运动仿真的方法。首先以目标鱼外形参数和分级能力为基础，确定活鱼分级机结构和分级闸门关键参数，从分级草鱼厚度参数分析分级闸门开合的条件，并确定分级机设计参数。其次建立分级关键机构在回转过程中的运动学模型，设计分级调节轨道的轮廓线，对升降闸门进行运动分析。最后使用Solidworks建立分级机的虚拟样机，将虚拟样机导入ADAMS虚拟软件，设置相关参数进行仿真分析。仿真结果显示：分级装置在电机转速为12 r/min运行时，分级闸门能完成3次上升动作且每次上升10 mm和1次回位动作，且每次上升或回位的时间能控制在1.25 s内，说明用齿轮齿条机构代替原机构同样可以达到运动要求。研究表明，回转式活鱼分级机具有稳定的机动性能，能够实现平稳的运动，满足活鱼分级的要求。该装置设计合理，为下一步试验样机设计提供依据。

关键词: 活鱼分级, 回转体, 稳定性, 运动分析

Abstract: In order to solve the problem of high damage and low efficiency in the grading process of live fish, an improved scheme of rotary live fish grading device was put forward. Replacement of the way of CAM mechanism and spring return mechanism to rotate graded baffle with the way of pinion and rack mechanism to raise graded gate could reduce the manufacturing cost and fault incidence. The 3d model was established and the method of motion simulation of key components was given. First, based on the contour parameters and grading capacity of the target fish, the structure of the live fish grader and the key parameters of the graded gate were determined, the opening and closing conditions of the graded gate were analyzed based on the thickness parameters of the graded grass carp, and the design parameters of the grader were determined. Second, the kinematics model of the grader key mechanism in the rotary process was established, the contour line of the graded regulation track was designed, and the movement analysis of the liftgate was carried out. Finally, Solidworks was used to establish the virtual prototype of grader, the virtual prototype was imported into ADAMS virtual software, and relevant parameters were set for simulation analysis. The simulation results show that when the grading device operates at a motor speed of 12 r/min, the graded gate can complete three rise actions (each rise is 10 mm) and one return action, and the time of each rise or return can be controlled within 1.25s, indicating that replacing the original mechanism with a pinion and rack mechanism can also meet the movement requirements. The results show that the rotary live fish grader has stable maneuverability and can achieve smooth movement, which meets the requirements of live fish grading. The design of the device is reasonable, which provides the basis for the design of the test prototype.

Key words:  Live fish grading, solid of rotation, stability, movement analysis