Mold temperature control system

Abstract

A mold temperature control system that controls temperature of mold in a diecasting machine, includes temperature sensors that detect mold temperatures of individual parts of the mold, flow controllers that control instantaneous flow rates of cooling water that cools the parts of the mold, and a control device that acquires the mold temperatures detected by the temperature sensors, computes deviations between target mold temperature and the current mold temperatures at every production cycle, converts the deviations into flow rate values, and transmits the flow rate values to the flow controllers.

What is claimed is: 
     
         1 . A mold temperature control system that controls temperature of a mold in a diecasting machine, comprising:
 temperature sensors that detect mold temperatures of individual parts of the mold, flow controllers that control instantaneous flow rates of cooling water that cools the parts of the mold, and   a control device that
 acquires the mold temperatures detected by the temperature sensors, 
 computes deviations between a target mold temperature and the current mold temperatures at every production cycle, 
 converts the deviations into flow rate values, and 
 transmits the flow rate values to the flow controllers. 
   
     
     
         2 . The mold temperature control system according to  claim 1 , wherein
 the control device
 compares a representative mold temperature and the current mold temperature in each of the parts of the mold, 
 computes the deviations, and 
 determines correction values for flow rates based on the deviations. 
   
     
     
         3 . The mold temperature control system according to  claim 2 , wherein
 the correction values
 are the same at all the parts of the mold, and 
 are used to adjust whole flow rate values by a constant amount. 
   
     
     
         4 . The mold temperature control system according to  claim 2 , wherein
 the correction values are different among the parts of the mold,   the correction values are regarded as 100% at a previous production cycle, and   the flow rate values are adjusted by individual ratios for the parts with respect to the correction values.   
     
     
         5 . The mold temperature control system according to  claim 3 , wherein
 the control device has a flow rate program set up in advance that makes the flow rates variable during the production cycle, and adds the correction value without changing a waveform of the flow rate program.   
     
     
         6 . The mold temperature control system according to  claim 4 , wherein
 the control device has a flow rate program set up in advance that makes the flow rates variable during the production cycle, and adds the correction value without changing a waveform of the flow rate program.   
     
     
         7 . The mold temperature control system according to  claim 1 , wherein
 the control device divides one period of the production cycle into three time zones of T 1 , T 2 , and T 3  by a timer, sets the flow rates of T 1  and T 3  to predetermined flow rates, and corrects the flow rate of T 2  by acquiring the mold temperature after finishing the production cycle and computing the flow rate value for a next production cycle.   
     
     
         8 . The mold temperature control system according to  claim 7 , wherein
 the correction is performed by increasing or decreasing the flow rate value in T 2 .   
     
     
         9 . The mold temperature control system according to  claim 7 , wherein
 defining that one period of the production cycle is T 4 , the correction is performed by increasing or decreasing time of T 2  within prescribed time of T 4 .   
     
     
         10 . The mold temperature control system according to  claim 1 , wherein
 the mold is configured with two sub parts,
 one of which is a fixed mold that is fixed to a body of the diecasting machine, and 
 the other of which is a movable mold that is repeatedly movable with respect to the body, and 
   the temperature sensors are disposed on one of the fixed mold and the movable mold, or both of the fixed mold and movable mold.