PURPOSE: To improve condition of the inner surface of a tube in an expansion rolling device, by providing the tip end of a pusher with a port for jetting water for the purpose of descaling the inner surface of a hollow tube stock and/or a port for jetting lubricant for lubricating the inner surface of the hollow tube stock.
CONSTITUTION: An jetting header 33 whose diameter is smaller than the inside diameter of a hollow tube stock 1 is provided nearly fixedly at the tip end of a pusher 30; and the jetting header 33 is provided with a water jetting port 34 and/or a lubricant jetting port 35 for lubricating the inner surface of the hollow tube stock; and a feeding piping is extended by which water and lubricant are supplied to each jetting port 34, 35. Consequently, in this case, water and lubricant are stably supplied to the part immediately before rolling on the inner surface of the hollow tube stock 1, in an expansion rolling mill 20 (without extending a rolling line) and with a simple piping structure.
SHIMIZU TETSUO
TOYOOKA TAKAAKI
