Bar press with hydraulic drive

Abstract

The invention relates to a bar and tube extruding press for forming metal ingots into profiles, tubes, bars or the like, comprising a male die and a female die, through which a metal ingot can be pressed by means of the male die, comprising a container, and comprising a driving device, in which the driving device comprises at least one main cylinder for applying the main pressing force of the male die to the metal ingots, characterized in that on the one hand the driving device comprises at least one speed-controlled internal gear pump for providing the hydraulic oil to the at least one main cylinder, by means of which the at least one main cylinder can be driven, and in that on the other hand the driving device additionally comprises at least one hydraulic advance and/or return cylinder for moving the male die in relation to the female die or at least one electrical drive for moving the male die in relation to the female die, by means of which the male die can he moved into a position in which the speed-controlled internal gear pump only then interacts with the at least one main cylinder in such a way that the main pressing force is applied to the male die by means of the at least one main cylinder.

1 . A bar and tube extruding press for forming metal ingots into profiles, tubes, billets, or the like, comprising a male die and a female die, through which a metal ingot can be pressed by means of the male die, comprising a ingot container, and comprising a driving device, in which the driving device comprises at least one main cylinder for applying the main pressing force of the male die to the metal ingots,
 characterized in that   the driving device on the one hand includes at least one speed-controlled internal gear pump for supplying hydraulic oil to the at least one main cylinder with which the at least one cylinder can be driven,   and on the other hand the driving device additionally comprises at least one hydraulic advance and/or return cylinder for moving the male die in relation to the female die or at least one electrical drive for moving the male die in relation to the female die, by means of which the male die can be moved into a position in which the speed-controlled internal gear pump only then interacts with the at least one main cylinder in such a way that the main pressing force is applied to the male die by means of the at least one main cylinder.   
     
     
         2 . The bar and tube extruding press according to  claim 1 , characterized in that the driving device includes means for moving the male die and/or the ingot container and/or the female die and means for applying a pressing force between the female die and the male die. 
     
     
         3 . The bar and tube extruding press according to  claim 1 , characterized in that the at least one electric drive preferably is an electric servo drive for moving the male die in relation to the female die. 
     
     
         4 . The bar and tube extruding press according to  claim 1 , characterized in that the internal gear pump can be driven using mixed friction from startup until the desired system pressure is reached. 
     
     
         5 . The bar and tube extruding press according to  claim 1 , characterized in that the driving device is connected to a control unit in which a characteristic curve or a plurality of characteristic curves for the internal gear pump and/or its drive motor(s) is/are stored. 
     
     
         6 . The bar and tube extruding press according to  claim 1 , characterized in that the pulsation of the internal gear pump, particularly the preferred internal gear pump, is lower than in axial piston pumps, preferably by at least 20%, preferably by at least 30%, compared to the pulsation of conventional axial piston pumps. 
     
     
         7 . A method of forming metal ingots into profiles, tubes, billets, and the like on a bar and tube extruding press having an ingot container, a male die and female die through which a metal ingot is pressed by the male die, a driving device including at least one main cylinder, at least one speed-controlled internal gear pump for supplying oil to the at least one main cylinder, at least one speed-controlled internal gear pump for supplying oil to the at least one main cylinder, and one of the at least one hydraulic advance/return cylinder and at least one electrical drive for moving the male die relative the female die, the method comprising the steps of: actuating the one of the at least one hydraulic advance/return cylinder and the at least one electrical drive for moving the male die is a predetermined position relative to the female die; and thereafter, actuating the at least one speed-controlled internal gear pump for supplying oil to the at least one main cylinder that applies a main pressing force to the mail die for pressing the ingot through the male and female dies. 
     
     
         8 . The method of  claim 7 , wherein the at least one electrical drive is used for moving the mail die, and the method further comprising the step of forming the electrical drive as an electric servo drive. 
     
     
         9 . The method of  claim 7 , comprising the step of driving the speed-controlled internal gear pump using mixed friction from startup until a desired system pressure is reached. 
     
     
         10 . The method of  claim 7 , comprising the step of selecting pulsation of the speed-controlled internal gear pump so that it is lower than pulsation of a conventional axial piston pump by at least 20%. 
     
     
         11 . The method of  claim 10 , wherein the pulsation selecting step includes selection of the pulsation of the speed-controlled internal gear pump which is lower than the pulsation of the conventional gear pump by at least 30%