Design and Test of Seedbed Preparation Machine before Transplanting of Rapeseed Combined Transplanter

Abstract

In order to satisfy the soil preparation requirements of a rapeseed combined transplanter in the middle-lower Yangtze River region in China where rice–rapeseed rotation cropping system was performed, a seedbed preparation machine composed of a rotary tillage device, ditch cleaning shovel, and soil leveling auger was designed to realize the function of rotary tillage, stubble ploughing, ditching, and soil leveling. The seedbed preparation machine was designed as the two parts of the middle section and the left–right symmetrical section to realize the need for middle ditching. Based on the principle of active scraping and anti-blocking, the curves of the soil contact section, soil throwing section, and transition section of the ditch cleaning shovel were analyzed. The structure parameters of the soil leveling auger with end reversal structure were designed. In order to further improve the working performance of the seedbed preparation machine, the response surface tests were designed, selecting the forward speed(X1), the rotation speed of rotary tillage blade roller(X2), and the rotation speed of soil leveling auger(X3) as the main influencing factors, taking the soil breaking rate and the straw coverage rate and the soil flatness as the test indexes. The optimal parameter combination was obtained as a forward speed of 0.94 m/s, rotation speed of rotary blade roller of 268 rpm, and rotation speed of soil leveling auger of 204 rpm. Under the optimal parameters combination, the soil breaking rate, straw coverage rate, and soil flatness were 92.06%, 93.01%, and 8.35 mm respectively, which satisfied the agronomic requirements of rapeseed blanket seedling transplanting. This study can provide a reference for the design of a seedbed preparation machine of a rapeseed combined transplanter.