Kinematics of Metallurgical Cutters With Parallel Blades

Abstract

Cutting with parallel blades cutters consists of three periods: blades ridging in metal; cutting; chipping (separation). Maximum force is required at the end of the ridging period and at the beginning of cutting. Since one of the blades is stationary, the second blade in cutting process has to go deep into the entire thickness of metal to cut the billet. For example, if thickness of metal is20 mm, then the upper blade needs to pass20 mmfor its cutting. If you make both blades moving towards each other, cutting effort will be less. In this case, each blade cutting20 mmof metal will pass 10mm. In order not to make mechanism of cutter with two movable blades too complicated, it is important to ensure its mobility from one drive. So, there acute the issue of arrangement possibility of blades moving towards each other with guaranteed strength of the units, transmitting effort on the blades. Kinematic scheme of cutters with blades moving parallel to each other in a vertical plane is proposed. Advantages of the proposed cutters design are the following: counter movement of blades requires less effort to cut the billet; force from each blade is distributed to two connecting rods, reducing load on each of them; since blades move towards each other, the main cutting force is distributed along the units of the mechanism and is transmitted to the engine, which reduces load on the frame and foundation when cutting; when blades move towards each other, metal separation occurs faster, it allows to concentrate maximal force during cutting with minimal load on the engine; the cut part of the billet does not fall below the roller bed at the end of cutting, so installation of the lower movable table is not required. Mobility of the proposed mechanism is determined by P.L. Chebyshev formula with its value = 1. Kinematic analysis of blades is carried out using a special method, which is in using point of connecting rods intersection.