Experimental Safety Analysis for Transplanting Device of the 4-Bar Link Type Semi-Automatic Vegetable Transplanter

The goal of this research was to analyze the load and safety of the transplanting device of the 4-bar link type semi-automatic vegetable transplanter under different workload conditions. To measure the strain at the transplanting device, a load measurement system was developed using 15 strain gauges. Field tests were conducted at 4 levels of engine speeds (750, 1000, 1250, and 1500 rpm) and 10 levels of the planting distance (0.29–0.47 m). The static safety factor was defined as the ratio between the strength of the material and the maximum stress in the transplanting device. The calculated stress data were converted from the time domain to the frequency domain using the rain-flow counting methods and Goodman’s Equation. The sum of fatigue damage was acquired based on the Palmgren–Miner’s rule. It was observed that the stresses increased with increasing engine speed and planting distance. The results show the higher engine speed and the longer planting distance will decrease the static safety factor and fatigue life. The static safety factor value was more than 1.0 for all locations and all working conditions. The minimum fatigue life was 49,153.3 h at link A (S_14), under the working condition of engine speed 750 rpm and planting distance of 0.35 m.