Method for operating a vacuum die-casting machine

Abstract

A method of determining the position of at least one opening ( 9, 10 ) in a casting chamber ( 6 ) of a die-casting machine ( 1 ), wherein a casting plunger ( 7 ) is contained in the casting chamber ( 8 ), The casting plunger ( 7 ) is movable into a position in which communication between the opening ( 9, 10 ) and the casting chamber ( 6 ) is no longer possible. It is determined, on the basis of the vacuum in the connecting line ( 14, 15 ), when the casting plunger ( 7 ) has reached the position in which communication, between the opening ( 9, 10 ) and the casting chamber ( 6 ), is no longer possible. A method of operating a vacuum die-casting machine, wherein a casting curve, for performing a casting cycle, is determined by specified and/or experimentally determined characteristic values of the die-casting machine by a computer program for operating the die-casting machine, and to a corresponding computer program product.

1 - 15 . (canceled) 
     
     
         16 . A method for ascertaining a position of at least one opening in a casting chamber of a die-casting machine, wherein a casting piston is contained in the casting chamber, the method comprising:
 a) connecting the casting chamber or a mold cavity of a die-casting moid, which mold cavity is fluidicaliy connected to the casting chamber, to a pump generating negative pressure or to a tank, which is brought to negative pressure with the pump, via a connecting line in a position of the casting piston in the casting chamber, in which at least a portion of the opening to be ascertained and the casting chamber can communicate with each other,   b) moving the casting piston into a position in which communication, between the opening to be ascertained and the casting chamber, is no longer possible, and   c) ascertaining with reference to the negative pressure in the connecting line when the casting piston has reached the position in step b).   
     
     
         17 . The method as claimed in  claim 18 , wherein the at least one opening is a feed opening of the casting chamber of a cold-chamber die-casting machine. 
     
     
         18 . The method as claimed in  claim 17 , wherein the method is carried out when the die-casting mold is dosed, and the connection to the pump generating negative pressure or to the tank, which is brought to negative pressure with the pump, is produced via the connecting line which is connected to an extraction hole of the die-casting mold. 
     
     
         19 . The method as claimed in  claim 17 , wherein the method is carried out when the die-casting mold is closed, and the connection of the casting chamber to the pump generating negative pressure or to the tank, which is brought to negative pressure with the pump, is produced via the connecting line which is connected to an intake opening in the casting chamber. 
     
     
         20 . The method as claimed in  claim 16 , wherein the at least one opening is an intake opening in the casting chamber of a cold-chamber die-casting machine, 
     
     
         21 . The method as claimed in  claim 20 , wherein the method is carried out when the die-casting mold is open, and the connection of the casting chamber to the pump generating negative pressure or to the tank, which is brought to negative pressure with the pump, is produced via the connecting line which is connected to the intake opening in the casting chamber. 
     
     
         22 . The method as claimed in  claim 18 , wherein, during a first performance of steps a) to c) when the die-casting mold is closed, the position of a feed opening in the casting chamber is ascertained, and, during a second performance of steps a) to c) when the die-casting mold is open, the position of an intake opening in the casting chamber is ascertained by the intake opening which is connected to the pump generating negative pressure orto the tank, which is brought to negative pressure with the pump, via the connecting line, the casting piston is subsequently moved into the position in which communication between the intake opening and the casting chamber is no longer possible, and it is ascertained with reference to the negative pressure in the connecting line when the casting piston has reached this position, 
     
     
         23 . The method as claimed in  claim 18 , wherein a gas cleaning device is located between the pump generating negative pressure or the tank and the casting chamber or the die-casting mold. 
     
     
         24 . A method of operating a vacuum die-casting machine, wherein a casting curve for carrying out a casting cycle on a basis of predetermined and/or experimentally ascertained characteristic values of the die-casting machine is determined with the aid of a computer program product for operating the die-casting machine. 
     
     
         25 . The method as claimed in  claim 24 , wherein the experimentally ascertained characteristic values of the die-casting machine involve a time taken until a predetermined negative pressure is reached in a mold cavity, 
     
     
         28 . The method as claimed in  claim 25 , wherein a time taken until a negative pressure corresponding to 90% of the predetermined negative pressure is reached in the mold cavity and the time taken until a negative pressure corresponding to 100% of the predetermined negative pressure is reached in the mold cavity are ascertained. 
     
     
         27 . The method as claimed in  claim 24 , wherein the predetermined characteristic values of the die-casting machine involve the position of the feed opening and/or of the intake opening in the casting chamber. 
     
     
         28 . The method as claimed in  claim 24 , wherein the time taken until a predetermined negative pressure is reached in the mold cavity is checked at regular intervals in order to identify any leak which may occur. 
     
     
         29 . The method as claimed in  claim 24 , wherein the casting curve is additionally determined as a function of a degree of filling of the casting chamber. 
     
     
         30 . A computer program product for operating a vacuum die-casting machine, wherein the software product executes the step of determining a casting curve for carrying out a casting cycle on the basis of predetermined and/or experimentally ascertained characteristic values of the die-casting machine.