IMPROVING THE DESIGN OF PLOUGHSHARES WITH A COMPOSITE CHISEL
Federal Scientific Agricultural Engineering Centre VIM and Russian Timiryazev State Agrarian University have developed an experimental design of trapezoidal ploughshares with a reversible composite chisel. The authors outline the design of the ploughshare core and the chisel that can be made from a rolling strip of a special cross-section form, with a stiffening rib located on the back surface of the core, extending from the furrow to the field cut in parallel to the share back and blade. The advantages of the new ploughshare design include low manufacturing costs; increased strength and durability; and the availability of the reversible chisel providing for a reversal of the chisel by 180 degrees after the wearing out of one of its cutting edges and thus the prolongation of its operation. The share core and the chisel are made of 30ХГСА steel grade hardened to 45...48 HRC; the share thickness in the stiffener is 12 mm, on the back line - 9 mm, and on the edge line of the blade - 2.5...3 mm. The length of the new share is 580 mm, the width - 125 mm, and the chisel extension - 40 mm, which provides good penetration when plowing hard soils. Experimental shares with reversible chisels were tested in 2015-2016, in the period from August to October in the farm "Krapivinsky" enterprise, Shchyokino district, Tula region. The tested soil had a medium loamy texture, the soil hardness during the testing period was 2.4...3.8 MPa. The experimental share was tested on the 8-base PLN-8-35 plow attached to K-700A tractor. The depth of plowing was 20...25 cm, which is typical for the considered soil-climatic zone. The machine speed was 8.5...10.5 km / h. According to the test results, the average operating time of the experimental plowshares was 85...90 ha/share, including the bit - 69...74 ha/share. All the tested shares were considered suitable for further operation. Field tests of new ploughshares without the use of expensive surfacing blades have shown their advantage over the resource of serial ploughshares of 2.5...3.3 times. The composite ploughshare of a new design can operate for at least one cycle of the annual ploughing season without the replacement of their spare parts.