IMPROVEMENT AND DETERMINATION OF THE PARAMETERS OF THE DIGGING WORKING PART OF THE POTATO DIGGER

Abstract

The digging working part is the first component of a potato digger that interacts with the ridge, soil clods and tuber nest. Its geometry strongly affects undercutting completeness, soil lifting, draft force, field capacity and tuber damage. This article presents an improved curved V-type digging share and determines its rational structural and operating parameters for a single-row potato digger intended for medium loamy ridged fields. The design combines a sharpened central nose, replaceable side cutting edges, a smooth lifting surface, short retaining wings and optional low-amplitude vibration. A calculation-based experimental matrix was used to evaluate the effect of rake angle, digging depth and forward speed on digging efficiency, undug tubers, damaged tubers, soil intake and draft force. The optimum parameter set was a blade width of 0.46 m, digging depth of 0.22 m, rake angle of 22 degrees, cutting-edge bevel angle of 30 degrees, side-wing angle of 10 degrees and forward speed of 2.4 km h-1. At this regime, digging efficiency reached 97.8%, damaged tubers were limited to 2.1%, undug tubers decreased to 1.8%, and draft force was 14.0% lower than that of a conventional flat share. The results show that improvement of the digging share must be based on a balanced combination of agronomic clearance, soil-tool mechanics and gentle tuber transfer rather than on excessive working depth or tractor power.