Device for the purification of machining liquids for electroerosion machines

Abstract

The device for purifying machining liquids for electroerosion machines, comprises a first ultrasonic decantation device ( 11 ) to separate by decantation the metallic contamination particles ( 38 ) from the machining electrode and the machined piece, a second ultrasonic decantation device ( 45 ) of a lower power to separate the particles ( 39 ) of said machining additive, and filtration elements ( 46 ) to separate carbonaceous particles ( 41 ) from the decomposition of the dielectric liquid. After filtration, this latter is remixed with the additive particles in a mixing receptacle ( 47 ) to obtain purified machining liquid.

1 . Device for purifying machining liquids for electroerosion machines ( 10 ) provided with an electrode ( 17 ) adapted to machine a piece ( 15 ), the machining liquid ( 14 ) being constituted by a dielectric liquid containing at least first particles ( 39 ) of an additive adapted to facilitate electroerosion and second particles ( 38 ) of contamination arising from the electrode ( 17 ) and/or from the piece ( 15 ) and having a higher density than the first particles ( 39 ), characterized by the fact that the device comprises at least one ultrasonic decantation device ( 11 ) comprising a first decantation receptacle ( 30 ) for the machining liquid ( 14 ) in which is disposed a first ultrasonic emission member ( 31 ) connected to a first ultrasonic generator ( 33 ) whose power can be adjusted such that the second particles ( 38 ) decant, whilst the first particles ( 39 ) remain in suspension in the dielectric liquid.  
     
     
         2 . Device according to  claim 1 , characterized by the fact that it comprises supply means ( 34 ,  35 ) for supplying contaminated machining liquid into the first decantation receptacle ( 30 ) and at least one opening ( 36 ) provided in this latter for discharging purified machining liquid containing the first particles ( 39 ).  
     
     
         3 . Device according to  claim 2 , characterized by the fact that it comprises supplemental means ( 40 ) to separate third particles ( 41 ) of contamination constituted by colloidal carbon from the decomposition of the machining liquid, these supplemental means ( 40 ) comprising a second ultrasonic decantation device ( 45 ) with a second decantation receptacle ( 50 ) in which is disposed a second ultrasonic emission member ( 51 ) connected to a second ultrasonic generator ( 53 ), the power of this latter being adjusted such that the first particles ( 39 ) decant, whilst the third particles ( 41 ) remain in suspension in the machining liquid, this second decantation receptacle ( 50 ) comprising an inlet connected to said opening ( 36 ).  
     
     
         4 . Device according to  claim 3 , characterized by the fact that the supplemental means ( 40 ) comprise a mixing receptacle ( 47 ) with mixing members ( 60 ), filtering elements ( 46 ) for the machining liquid obtained by decantation at the outlet of the second decantation receptacle ( 50 ) and arranged to retain by filtration the third particles ( 41 ), a supply conduit ( 59 ) for the filtered dielectric liquid from the filtration elements ( 46 ) to said mixing receptacle ( 47 ) and extraction transport means ( 55 ) arranged to transport the first particles ( 39 ) decanted from the second decantation receptacle ( 50 ) into the mixing receptacle ( 47 ).  
     
     
         5 . Device according to  claim 4 , characterized by the fact that said extraction and transport means are constituted by a conveyor belt ( 55 ) arranged in the bottom of the second decantation receptacle ( 50 ) and extending just above the mixing receptacle ( 47 ) to discharge the first particles ( 39 ) into this latter.  
     
     
         6 . Device according to  claim 3 , characterized by the fact that the first ultrasonic generator ( 33 ) is adjusted to a power comprised between 10 and 50 watts, preferably between 40 and 100 watts, and by the fact that the second ultrasonic generator ( 53 ) is adjusted to a lower power, comprised between 1 and 30 watts, preferably between 5 and 20 watts.