关键词: 可降解穴盘, 圆盘切刀, 静强度分析, 模态分析

Abstract:  In order to solve the problem of the poor cutting effect of the cutters on the degradable cutters in the seedling device of the existing automatic transplanting machine, the cutters in the seedling device were optimized. Using SolidWorks software, the threedimensional models of 24 tooth single and double edge disc cutters, 36 tooth single and double edge disc cutters, and 48 tooth single and double edge disc cutters were established. The finite element static strength analysis of six kinds of disc cutters was carried out using ANSYS software. The simulation results showed that the maximum stress and the maximum strain generated by the 24tooth doubleedged disc cutter during the process of cutting the degradable disc were the minimum values, which were 1.658 4×105 Pa and 8.350 2×10-7 m/m, respectively. According to the stress and strain data obtained from the static analysis, the regression model of the effect of the number of teeth and the shape of the cutting edge on the maximum stress and strain and the test factor response surface were obtained using the DesignExpert, and the regression model equation between the maximum stress and strain and the number of teeth and the shape of the cutting edge was obtained. It was determined that the best combination form of disc cutter was 24 teeth double edge disc cutter. The Modal analysis was carried out to get the 10order vibration shape of the disc cutter. Through analyzing the relationship between natural frequency and speed, it was verified that the rated working speed of the disc cutter was 334 Hz when it normally cut the degradable disc. The critical speed of disc cutter resonance was 202.7 Hz. The critical speed of disc cutter resonance was higher than the actual working speed, and the possibility of resonance was very slight. The cutting test of the disc cutter showed that the qualified rates of the 24tooth doubleedged disc cutter were 88.9%, 86.1%, and 80.6%, respectively, under the rotating speed of 350 r/min, 400 r/min, 450 r/min, which could maintain good cutting stability.

Key words: degradable plug, disc cutter, static strength analysis, modal analysis