Arrangement of devices and a method for empirically for determining efficiency index in abrasive waterjet cutting and application thereof in a device for simultaneous control of abrasive waterjet cutting

Abstract

An arrangement of devices for determining an efficiency index in abrasive waterjet cutting, i.e. the index unambiguously defining for a certain material the shape of a cut, roughness of surfaces created by cutting, their conical nature depending on the incidence angle of the abrasive waterjet. The arrangement of the invention consists of a known abrasive waterjet cutting machine ( 1 ), a thermographic camera ( 2 ) and a computer ( 3 ), wherein a workpiece ( 4 ) is arranged on said machine ( 1 ), said workpiece being intended to undergo a cutting procedure; and fixed and variable process parameters (A) of cutting are known: hydraulic, cutting, mixing, abrasive and input parameters of said workpiece. Said thermographic camera ( 2 ) is positioned in a way to record in front view the entire front surface ( 5 ) of a cut in the workpiece ( 4 ) in a known time interval, in that an adequate programme within said computer ( 3 ) allocates to each thermographic image ( 6 ) cutting parameters (A) that were valid for each point (B) of cutting and finally shows them in the form of a table or chart of a relationship between the efficiency index and one of the parameters (A).

1 . An arrangement of devices for determining an efficiency index in abrasive waterjet cutting, i.e. the index unambiguously defining for a certain material the shape of a cut, roughness of surfaces created by cutting, their conical nature depending on the incidence angle of the abrasive waterjet, wherein said arrangement consists of a known abrasive waterjet cutting machine ( 1 ), a thermographic camera ( 2 ) and a computer ( 3 ), wherein a workpiece ( 4 ) is arranged on said machine ( 1 ), said workpiece being intended to undergo a cutting procedure; and fixed and variable process parameters (A) of cutting are known: hydraulic, cutting, mixing, abrasive and input parameters of said workpiece, characterised in that said thermographic camera ( 2 ) is positioned in a way to record in front view the entire front surface ( 5 ) of a cut in the workpiece ( 4 ) in a known time interval, in that an adequate programme within said computer ( 3 ) allocates to each thermographic image ( 6 ) cutting parameters (A) that were valid for each point (B) of cutting and finally shows them in the form of a table or chart of a relationship between the efficiency index and one of the parameters (A). 
     
     
         2 . Arrangement as claimed in  claim 1 , characterised in that the most adequate parameter (A) for a link to the efficiency index is the speed of cutting. 
     
     
         3 . Method for empirical determination of an efficiency index in abrasive waterjet cutting by use of the arrangement as claimed in  claim 1 , characterised in that prior to industrial application of any material on its sample, cutting is performed on the arrangement of devices described above, charts or tables are then prepared and offered to users of the treated material, who use the data from said tables or charts to set their abrasive waterjet cutting device. 
     
     
         4 . A device for the control of the abrasive waterjet cutting device ( 1 ), characterised in that it consists of a thermal camera ( 2 ), oriented towards the cut in a way to detect it in front view, of a microprocessor ( 3 ) receiving the images from said camera ( 1 ), wherein said camera evaluates each image separately based on the data from a library ( 5 ) of data, which are needed for the creation of control signals for a continuous changing of parameters (A) of cutting: speed of advancement of a workpiece, waterjet pressure, content of abrasive material in the waterjet, distance of a cutting head ( 6 ) from a surface ( 7 ) of a workpiece ( 8 ) etc., further of a library ( 9 ) of data (B) on the shapes of a cut with belonging properties, especially precision and roughness of cutting and then generates control signals for the control of said device ( 1 ). 
     
     
         5 . Device as claimed in  claim 1 , characterised in that it may be joined to a device ( 1 ) and separated from said device ( 10 ) for cutting in industry, wherein the data (A) obtained by the device of the invention are transferred to the device ( 10 ) in a digital or written form, so that an operator of said device ( 10 ) can use the data (A) as the process advances based on the current need.