| 摘要 |
<p>PURPOSE:To provide manufacturing method for a cylindrical annulus type eye joint capable of giving high precision products with improved productivity extremely reducing machining man-hours and saving useless material by unnecessitating the machining to a recessed groove flowing passage in the inner part. CONSTITUTION:A metallic columnar piece 1 is provided with a recessed part 1' on a first die by a first punching tool and also, the neighborhood of the lower part at the outer peripheral side is formed into conical inclined surface 1''. Successively, this piece is set on a second die and the recessed part 1' is formed to the hollow cylindrical annulus 2 having bottom part by a second punching tool. The cylindrical annulus is fitted to a third die and the neighborhood of this opening edge 2' is bent inward by a third punching tool to form a steep inclined surface 3 and further, formed from the steep inclined surface to a gentle inclined surface 4 by a fourth punching tool. By using a fifth punching tool, flattening work is applied in parallel to the gentle inclined surface 4 and a wall surface 2'' at the bottom part as the seat surfaces 5, 5'. At the same time of or successively to this work, fitting holes 6, 6' are formed and penetrated at the center part of the seat surface 5, 5'. A connecting hole 7 is formed at the side wall part by boring.</p> |
