| 摘要 |
PROBLEM TO BE SOLVED: To improve impact resistance and abrasion resistance by symmetrically distributing a flow of carbide in a cross-sectional tissue to a perpendicular lowered to a bearing inserting hole part from a knife edge top part, and forming it in a layer shape along a contour shape of a knife edge. SOLUTION: A cutter ring for an excavator is forged and molded in a shape close to the final product containing a bearing inserting hole by being sandwiched from above and below by a pair of metal molds whose cavity shape is symmetrical. Since annealing is performed from a bearing part as a heat treatment method, a knife edge part is hardened most, and the distribution of being gradually softened toward a bearing inserting hole part is formed in a bearing inserting hole part peripheral area, and an impactive unbalanced load transmitted from the knife edge part is damped by a bearing part, and damage of a cutter ring and a bearing is prevented. A flow of forged fiber in an edge part tissue in a cross section when cut by a plane containing a rotary central shaft of the cutter ring, is symmetrically distributed to a perpendicular lowered to the bearing inserting hole part, and a flow of the forged fiber existing in the knife edge part tissue is formed so as to become a layer shape along a contour shape of the knife edge part. |
