| 摘要 |
<p>A continuous casting apparatus of the type wherein liquid ferrous metal is received at the inlet end of a mold and the cast bar is withdrawn in intermittent withdrawal motions from the exit end of the mold. The successive withdrawal motions are at speeds in excess of that at which the molten metal solidifies against the rear face of the bar, so that on each withdrawal an initially independent and separate new section is formed behind the withdrawing bar, with the freezing progressively taking place in the same direction as bar withdrawal. The new section later freezes against the rear face of the formed bar during the dwell period between the intermittent withdrawal motions, so that on each successive withdrawal motion the newly formed section adheres to and becomes a part of the withdrawn bar. In accordance with the present invention, the bar-withdrawing roll, which is spaced from the rear face of the bar, has a brake affixed thereto. The brake reaction force is taken up by a pendulously suspended unit having a depending ear which oscillates between an adjustable stop engaged when the roll rotates in the reverse direction and a spring-biased detent backed up by a fixed stop when the roll rotates in the bar-withdrawing or forward direction. The roll drive mechanism is arranged to impart a slight reversed roll motion during the dwell period. It has been found that without the brake unit the apparatus operates unreliably and erratically, especially after some usage, but with the brake arrangement (and the incident instantaneously applied reverse force over a predetermined distance when the forward bar movement stops) the continuous casting apparatus operates reliably and effectively over a prolonged period of time.</p> |
