Precision terminal mold clearance hedge cutting surface quality of precision terminal mold clearance hedge cutting surface quality and the effect of blanking process of blanking clearance is reasonable, will decide whether the fracture and crack, shear force equilibrium, and determine the size of the burr.
Therefore, precision terminal mold design, manufacturing and installation must ensure uniform clearance, the same manufacturing process of convex concave die clearance should be kept in a reasonable range.
Otherwise, precision terminal mold there will be a part of the quality of clearance is too large and too small.
Reasonable: precision terminal mold clearance when the convex and concave clearance fit, convex and concave die blade edge direction of maximum shear stress near the crack can meet in blanking process, although at this time section and the material surface is not perpendicular, but still relatively flat, smooth, burr, smaller parts of the cross section quality is better.
Precision terminal mold gap too small clearance, small bending deformation zone is small, high compressive stress components.
Produced by die near the edge crack into the punch below the compressive zone and stop development;
Produced by punch near the edge into a concave die crack on the surface of the compressive stress area and stop developing.
Upper and lower crack don't overlap.
In the crack between the two materials will be the second shear.
When the crack on the pressure into the concave die, die wall extrusion, produce the second euphotic zone, at the same time part of the material being squeezed out, burr in form a thin and tall.
Clearance after hours, although small bending Angle is small, arch collapse, but the quality section have drawbacks.
Such as central section a sandwich, two head euphotic zone, in the end have long burr.
Precision terminal mold clearance is too large when the gap increases, the tensile stress within the material increases, the tensile fracture occurred early and fault zone width;
Narrow euphotic zone;
Bending deformation increases, bending Angle and arch collapse also increased.
Clearance is too large, because bending moment is big, high tensile stress component, the material in the convex and concave die cracking near the edge is no coincidence.
After the separation of slope fault increases, parts of cross section in two Angle alpha 1 and alpha 2, cross section quality is not ideal.
And, because the flat Angle of big, big arch bending, shining with small, burr was tall and thick, lower quality of blanking pieces.