| 摘要 |
<p>Disclosed is a friction-assisted hot extrusion method for producing hollow articles involving the following steps: the hollow blank (1) which is to undergo extrusion is pre-heated and placed inside the lining (2) of a container (3), a spike being passed through the hollow cavity of the blank (1) when inside the lining; using the short plunger (6) and simultaneously displacing the container (3), spike (4) and short plunger (6), material is extruded through the annular gap which is formed by the channel of the die (5) and the spike (4) and determines the shape and geometrical dimensions of the finished article. During the extrusion process, the rate of displacement Vc of the container (3) and the rate of displacement Vm of the spike (4) exceed the rate of displacement Vr of the short plunger (6). The hydraulic press comprises the following elements rigidly mounted on a base (9): front and rear crosspieces (10 and 11 respectively); the container (3) capable of reciprocal motion along the longitudinal axis of the press; a main moveable crossbar (13) on which is rigidly mounted a plunger; at least one main power cylinder whose main body (19) is rigidly mounted on the rear crosspiece (11); and an additional cylinder which is also connected to the main moveable crossbar (13) and on whose plunger (30) the hollow short plunger (6), which is formed in one piece with the press plate (33), is rigidly mounted. In the hollow cavity of the plunger is arranged the spike (4) with a spike holder (36) which is provided with the plunger (35) of the power cylinder and with its own moveable crossbar (37).</p> |
