PL398592A1 - Method for turnover crimping with internal threads - Google Patents

Abstract

The method of rotary crimping of products with internal threads, especially the axis-symmetrical forgings with internal protrusions in the shape of a screw line, is characterized by the fact that the blank (3) in the form of a sleeve is placed between three identical tools (1a), (1b) and (1) roller, while inside the blank (3) there is a mandrel (2) shaped, on the surface of which there are external projections in the shape of a screw line, then the tools (1a), (1b) and (1c) are set in a rotational motion in the same direction and with the same velocity (n1) and progress towards the blank axis (3) with constant velocity (V), as a result of which the blank (3) and the internal mandrel (2) shaped inside it rotate with constant velocity n2 in opposite to the rotation of tools (1a), (1b) and (1c) and the outer diameter of the blank (3) is reduced, as a result of which the internal screw projections in the blank are shaped cut (3) on the spindle (2) shaped, after reaching the tools (1a), (1b) and (1c) the end position, their progressive movement is switched off, while the tools (1a), (1b), (1c) turn with constant speed (n1), as a result of which the shaped internal screw profile in the product is calibrated, then the rotational movement of the shank (2) with the constant speed n3 in the direction consistent with the rotational movement of the tool (1a), (1b), (1c) , as a result of which the shank (2) shifts with constant speed V0 from the product.