Patent ID: 8650926
Filing Date: 2014-02-18
Classification: B21C

Abstract:
1. An extrusion press comprising a container mover that moves a container at an end platen and molding a product by extruding a billet loaded in the container from a die by a stem of a main cylinder device, wherein: a hydraulic pressure of the main cylinder device in an extrusion process is detected; a deviation between the detected hydraulic pressure and a reference pressure set in advance is mathematically processed; and wherein the extrusion press comprises a controller, which is capable of sending an output to the container mover to reduce a container sealing force when the deviation is more than zero and the container sealing force exceeds an amount or container sealing force corresponding to the reference pressure, and to increase the container sealing force when the deviation is less than zero and the container sealing force is less than the amount or container sealing force corresponding to the reference pressure, so that a constant container sealing force corresponding to the reference pressure acts on an end surface of the die; and the reference pressure is set, before beginning the extrusion process, in a pressure range lower than a maximum extrusion load pressure and higher than a required extrusion load pressure that acts on the die.