| 摘要 |
An agricultural disc blade 5 has a cross section that is at least in part a non-circular geometric curve e.g. an ellipse, a parabola or a catenery. A method of manufacturing such a disc comprises the steps of:- a. Producing circular blanks from steel strip; b. Piercing a centre hole or holes; c. Producing any required cut-away portions (13; Fig.4); d. Bevelling at (14, 15, Figs. 7-9) the circumferential cutting edge 8, either by roll forming or metal removing; e. Hot forming the concavity, the central, circular area 6 and any ribs 10 or ripples/flutes in one tool 16; f. Heat treating by quenching in oil or water based emulsion; g. Heat tempering to obtain the optimum combination of hardness and mechanical properties; and h. Coating with primer paint. <IMAGE> |
