| 摘要 |
<p>A light weight drive shaft (10), such as for use as an automotive vehicle engine drive shaft for transmitting engine power, is extruded from a tubular metal blank (20) into an elongated tube (12) having integral center and opposite end sections, with the center section having a thin wall and the end sections having a thick wall. The shaft (10) is formed by inserting a tubular blank (20) within a tubular die (25) having a constricted die throat (27) through which the blank (20) is extruded. A punch (30) having a lead end punch extension (32), is inserted within the die (25), against the trailing end of the blank (20), with its extension (32) extending part way into the blank (20). Movement of the punch (30) towards the die throat (27) extrudes the blank (20) through the throat (27), causing the leading portion of the blank to collapse inwardly to form the thick wall end section (12) until continued movement of the punch positions the extension (32) within the die throat (27). Thereafter, further movement of the punch (30) extrudes the thin wall center section (11) with the punch extension (32) acting as a mandrel, until completion of the desired center section length. Then, the punch (30) is removed from the die end blank (20) and a second blank (35) is inserted in the die (25) and the punch (30) is reinstalled within the die (25) with its extension (32) extending part way into the second blank (35). Movement of the punch (30) towards the throat (27) now completes the extrusion of the trailing end portion (13) of the first blank (20), due to the pressure of the second blank (35), with the trailing end portion (13) of the first blank (20) and the leading end portion of the second blank (35) collapsing inwardly to form their respective thick wall end sections, until the first blank (20) is completely extruded. Thereafter, the cycle is repeated. <IMAGE> <IMAGE></p> |
