Wire drawing die with non-cylindrical interface configuration for reducing stresses

摘要

The present invention is addressed to improving a blank for a wire drawing did (60) formed from an annular cemented metal carbide support component (66) having a lengthwise extent from an entrance end (68) to an exit end (78) and extending radially about a central longitudinal axis (75) to define a cylindrical internal bore through the lengthwise extent, and a cylindrical sintered polycrystalline compact component (62) received within the bore of the support component and bonded thereto at an interface surface (63) extending a radial distance from and along the longitudinal axis from a wire drawing entrance end to a wire drawing exit end. The compact component is adapted to receive an aperture extending through its lengthwise extent about the central longitudinal axis and is configured with an entrance zone (1) at the did entrance end which tapers inwardly therefrom to a reduction zone (2) whereat a wire to be drawn through the aperture makes initial contact with the compact component, and thence to a bearing zone (3) and an exit zone (4). The improvement in such wire drawing did blank involves the radial distance from said central longitudinal axis to said interface surface tapering inwardly (74) from the entrance end to a minimum prior to the bearing zone after which said radial distance remains substantially constant to said exit end. The corresponding wire drawing did and the method for producing the inventive wire drawing blank also form additional aspects of the present invention. <IMAGE>