Electric discharge machine and machining fluid cooling device

Abstract

An electric discharge machine controls temperature fluctuations of machining fluid discharged by a discharge pump so as to improve machining accuracy, and a machining fluid cooling device keeps the temperature of the discharged machining fluid constant regardless of the operating state of the discharge pump. The electric discharge machine pumps machining fluid in a temperature controlled clean fluid tank with a discharge pump and discharges the machining fluid to a machining area through piping, and has a machining fluid cooling device for cooling machining fluid discharged from the discharge pump. The machining fluid cooling device passes a portion of the piping through the clean fluid tank and exchanges heat between the machining fluid inside the piping and the clean fluid in the clean fluid tank, thus dispersing the heat added from the discharge pump to the clean fluid side and lowering the temperature of the machining fluid inside the piping.

1 . An electric discharge machine comprising: 
 a clean fluid tank containing machining fluid with temperature thereof controlled;    a discharge pump for discharging machining fluid in said clean fluid tank to a machining area through piping; and    a machining fluid cooling device provided between said discharge pump and the machining area, for cooling the machining fluid discharged from said discharge pump.    
   
   
       2 . An electric discharge machine according to  claim 1 , wherein said machining fluid cooling device comprises a part of the piping passing through said clean fluid tank to exchange heat between the machining fluid inside the part of the piping and the machining fluid contained in said clean fluid tank.  
   
   
       3 . An electric discharge machine according to  claim 2 , wherein said part of the piping is provided with fins.  
   
   
       4 . An electric discharge machine according to  claim 1 , wherein a machining fluid temperature control device is provided for controlling the temperature of the machining fluid in said clean fluid tank, and the machining fluid temperature control device functions as said machining fluid cooling device for cooling the machining fluid discharged from said discharge pump.  
   
   
       5 . A machining fluid cooling device for an electric discharge machine in which machining fluid contained in a clean fluid tank with temperature thereof controlled is discharged by a discharge pump to be sent to a machining area, said machining fluid cooling device comprising: 
 piping for conducting the machining fluid discharged from the discharge pump to the machining area; and    a heat exchanger connected with said piping and arranged in the machining fluid in the clean fluid tank, for cooling the machining fluid discharged from the discharge pump by heat exchange with the machining fluid in the clean fluid tank.    
   
   
       6 . A machining fluid cooling device according to  claim 5 , wherein said heat exchanger comprises a part of the piping passing through the clean fluid tank to exchange heat between the machining fluid inside the piping and the machining fluid in the clean fluid tank.  
   
   
       7 . A machining fluid cooling device according to  claim 6 , wherein said portion of the piping passing through the clean fluid tank is provided with fins.