| 摘要 |
<p>The present invention relates to a method for forming holes by extrusion and an extruding tool for making the method, and is characterized in that a body (4) for guiding punches with a blank (1) inserted therein is introduced into a calibration bushing (6), whereby the punches (5) being provided with return springs (9) and located in said punch guide body (4) bear against said blank (1) outside diameter. By the action of axial force onto a clamping pin (19) in the direction of longitudinal axis thereof a calibration mandrel (2) is inserted in the blank (1) and said punch guide body (4) with punches (5) and the return springs (9) is broached through the tapered calibration bushing (6). Owing to compression of the punches (5) inside said calibration bushing (6) the axial force is changed to radial force and packing of said blank (1) material on a shaped portion (23) of said calibration mandrel (2) takes place. During backward motion of the calibration mandrel (2), a scraper (8) retains said punch guide body (4) and said blank (1) packed on the calibration mandrel (2) is extended from said punch guide body (4). Withdrawal of the calibration mandrel (2) from the blank (1) is carried out in an auxiliary fixture by rotating the calibration mandrel (2). An extruding tool for making the above described process consists of an extruding punch having a calibration mandrel (2) and an extruding die with a base (10). Said extruding punch is attached by means of a clamping pin (19) to an extruder hammer block and said extruding die with the base (10) is placed underneath the extruder hammer block. On the calibration mandrel (2) there is performed a shaped portion (23) and on the base (10) there is located a collar (7), inside of which a calibration bushing (6) is placed. A punch guide body (4) with punches (5) and return springs (9) is mounted in the calibration bushing (6). Above the collar (7) and said calibration bushing (6) there is situated a plate (11) with a ring (12) and a scraper (8) disposed thereon. Between the ring (12) and the scraper (8) there are inserted springs (13). The assembled extruding die is closed by a clamping ring (14).</p> |
