DEVICE FOR TESTING SHEET MATERIALS Russian patent published in 2017 - IPC G01N3/28 

FIELD: metallurgy.

SUBSTANCE: device comprises a punch, a matrix and a clamp, characterized in that a rift of a triangular cross-section in a circle plan concentric to the round contour of the punch is made on the clamp, the end of which is flat with an undercut and with a radially rounded edge. The matrix is provided with a depression for this rift, taking into account the thickness of the test sheet material in such a way that in the clamped state the side surfaces of the rift and the workpiece fit tightly to each other with the presence of a gap between the workpiece and n the clamping plane, from which the rift protrudes. The device contains a technological spacer placed under the workpiece with identical dimensions of the material, the plasticity indices of which are not lower than the plasticity indeces of the test workpiece, the technological spacer contains a hole with a diameter smaller than the punch diameter, a powder of rosin type is located between the contacting defatted surfaces of the technological spacer and the workpiece. Between the technological spacer and the punch there is an antifriction pad, made of polyethylene or teflon with a lubricant, applied to its upper and lower sides.

EFFECT: reduction of labor, time and cost of building the forming limit diagram of sheet materials, reduced time and improved quality of process design and tooling for sheet stamping, receive savings of sheet material by as well as significant simplification of the sheet material selection and equipment for parts sheet stamping.

6 cl, 1 dwg