초록 ▼

A vacuum valve control system for a vacuum die casting machine that controls the opening and closing of a vacuum valve. The system comprises an input device for entering certain values, a detecting device for determining the position and speed of an injection plunger, a processor to calculate when t

A vacuum valve control system for a vacuum die casting machine that controls the opening and closing of a vacuum valve. The system comprises an input device for entering certain values, a detecting device for determining the position and speed of an injection plunger, a processor to calculate when the injection plunger has reached particular values for position and speed and a control device for opening and closing the vacuum valve when the particular values have been reached. The processor includes two counting devices, one to calculate the position of the injection plunger and one to calculate the speed of the plunger. The control device includes solid state relays which energize a solenoid to open the vacuum valve when the plunger has reached a certain position. The solid state relays also deenergize the solenoid to close the vacuum valve when either another particular position of the plunger has been reached or when the plunger is approaching a certain speed. By monitoring the speed and position of the injection plunger to control the vacuum valve, the chance that molten metal will be suctioned into the vacuum system of the vacuum die casting machine is greatly reduced.

대표청구항 ▼

[ What is claimed is:] [1.] A vacuum die casting apparatus comprising in combination:a mold having a cavity;vacuum means connected to said mold for evacuating said cavity;a vacuum valve between said cavity and said vacuum means;an injection plunger for filling said cavity with material; anda control

[ What is claimed is:] [1.] A vacuum die casting apparatus comprising in combination:a mold having a cavity;vacuum means connected to said mold for evacuating said cavity;a vacuum valve between said cavity and said vacuum means;an injection plunger for filling said cavity with material; anda control system comprising:speed input means for entering a first speed of said injection plunger;speed processing means for calculating a second speed based on said first speed and for determining when said injection plunger has reached said second speed; andmeans for closing said vacuum valve when said injection plunger has reached said second speed. [6.] A method for controlling a vacuum die casting system which includes a mold having a cavity, vacuum means connected to said mold for evacuating said cavity, a vacuum valve between said cavity and said vacuum means, and an injection plunger for filling said cavity with material, said method comprising the steps of:determining a first speed of said injection plunger;calculating a second speed based on said first speed;measuring the speed of said injection plunger;comparing said measured speed with said second speed; andclosing said vacuum valve if said measured speed is greater than or equal to said second speed.