Abstract: A method for electrical discharge machining (EDM) a workpiece by means of a train of machining pulses. During the machining time the machining pulses are applied to the working gap between workpiece and electrode. An open voltage is first applied, the ignition delay time td is measured, then, at the beginning of the discharge, its fall time tf is measured, and certain shape features (e.g. the pedestal and ramp) of the pulse are adapted in real time for the very same discharge, as a function of said ignition delay time and/or fall time. Moreover, instead of shaping the very same discharge, one or more subsequent discharges can be shaped as a function of td and/or tf of a single discharge, or of an average of td and/or tf over several discharges.

Abstract: The invention relates to a method and device for wire electrical discharge machining (WEDM), in which a first voltage UCH1 is measured between a first current feeder and the workpiece, and a second voltage UCH2 is measured between a second current feeder the workpiece, whereas said first- and second voltage UCH1, UCH2 are measured when current of the machining discharge pulse is zero, for instance at the end of the of the machining discharge current pulse, and a voltage difference of said measured voltages ?UCH=UCH1?UCH2 is determined, and a discharge position of said machining discharge pulse is determined in real time, as a function of said voltage difference ?UCH.

Abstract: The invention relates to a method and device for electrical Wire electrical discharge machining method (WEDM) for forming a desired pattern on a workpiece by a WEDM machine tool, in which a preliminary voltage pulse is applied to a gap between a wire electrode and a workpiece, and in which, at the breakdown of said preliminary voltage pulse, a first machining discharge pulse is applied to the wire electrode.

Abstract: A method and device for electrical discharge machining (EDM) a workpiece by means of a train of machining pulses. During the machining time the machining pulses are applied to the working gap between workpiece and electrode. An open voltage is first applied, and it is increased to a second open voltage level if a discharge does not occur within a waiting time d0, and further increased to a third open voltage level if a discharge does not occur within a second waiting time d1. An average product of the actual open voltages times the partial ignition delays is computed and subtracted from the product of a reference open voltage times the total ignition delay, and the servo setpoint value is adjusted accordingly. The actual axes positions are sampled in real time and the discharge electrical parameters are adjusted accordingly. The discharge electrical parameters can be adjusted according to the duration of d0 and d1.

Abstract: A method for the machining of workpieces (11) and inspection of the processed workpiece surface in a machine tool (1), preferably a die sinking electrical discharge machine. The method uses at least one machining process interruption during which the processed surface of the workpiece (11) is inspected. Within said machining process interruption, at least one image of the processed workpiece surface is captured on the machine tool (1) by means of a digital camera (12). The images are processed by one or two pattern recognition algorithm (PRA D, PRA S), which were previously trained to determine the surface characteristics such as roughness parameters, functional surface features and/or characteristic defects of the processed workpiece surface captured on that at least one image. The determined surface characteristics are used to resume the processing of the workpiece surface with or without adjusting the processing parameters.

Abstract: A method for the machining of workpieces (11) and inspection of the processed workpiece surface in a machine tool (1), preferably a die sinking electrical discharge machine. The method uses at least one machining process interruption during which the processed surface of the workpiece (11) is inspected. Within said machining process interruption, at least one image of the processed workpiece surface is captured on the machine tool (1) by means of a digital camera (12). The images are processed by one or two pattern recognition algorithm (PRA D, PRA S), which were previously trained to determine the surface characteristics such as roughness parameters, functional surface features and/or characteristic defects of the processed workpiece surface captured on that at least one image. The determined surface characteristics are used to resume the processing of the workpiece surface with or without adjusting the processing parameters.

Abstract: The invention relates to a method for electrical discharge machining of workpieces by electrical discharge pulses generated by a power module of an electrical discharge machine. The invention is characterized in that firstly the discharge voltage of a number N1 of electrical discharge pulses is acquired and stored, secondly a front discharge voltage (63) is determined out of this amount of N1 acquired discharge voltages and thirdly, the voltage Uhps (64) of the electrical discharge pulses produced by the power module for machining the workpiece (17) is adjusted in function of the determined front discharge voltage (63).

Abstract: A dielectric fluid composition for electric discharge machining is based on saturated hydrocarbons and contains an additive wherein the additive comprises at least one carboxylic acid or a glycerol ester of a carboxylic acid and at least one amine. Preferably, the additive comprises tall oil fatty acids (TOFA). The saturated hydrocarbons have a low content of aromatic hydrocarbons, which is less than 1% w/w. The additive is present in concentrations from 1 to 25%, preferably 5 to 15% by weight in the dielectric fluid. The additive is soluble in the saturated hydrocarbon basis.

Abstract: The invention relates to a method for electrical discharge machining of workpieces by electrical discharge pulses generated by a power module of an electrical discharge machine. The invention is characterized in that firstly the discharge voltage of a number N1 of electrical discharge pulses is acquired and stored, secondly a front discharge voltage (63) is determined out of this amount of N1 acquired discharge voltages and thirdly, the voltage Uhps (64) of the electrical discharge pulses produced by the power module for machining the workpiece (17) is adjusted in function of the determined front discharge voltage (63).

Abstract: A method of operating a machine tool, e.g., an electrical discharge machine, and a machine tool system with a machine, e.g. an electrical discharge machine, for machining a workpiece may include numerous configurable modules (DRIVE; GEN; CONTROL) to perform at least one of controlling, monitoring and carrying out of the machining of a workpiece. The modules (DRIVE; GEN; CONTROL) are arranged on the machine and are linked by a data network to a node for at least one of sending data to the node and receiving data from the node.

Abstract: A method for electrical discharge machining a workpiece includes dividing machining time into a sensing interval during which reference values are captured from machining pulses and into a machining interval during which no reference values are captured. The sensing interval includes either a first sensing interval after implementation of a jump motion of the electrode in the working gap or a second sensing interval after application of an extended pause time to at least some of the machining pulses. The extended pause time is longer than a pause time of other ones of the machining pulses. The method also includes sensing an electrical parameter of a current machining pulse and deriving at least one characteristic value from the sensed electrical parameter. The method further includes comparing characteristic value to at least one of the captured reference values and initiating an action depending on a result of the comparison.

Abstract: The invention relates to a method and device for electrical discharge machining (EDM) a workpiece by means of a train of machining pulses. During the machining time the machining pulses are applied to the working gap between workpiece and electrode, whereby an electrical parameter of the current machining pulse applied to the working gap is sensed, from which at least one characteristic value is derived. This is compared to a reference value, and depending on the result of the comparison, actions are initiated. The reference value is captured on the basis of at least one earlier machining pulse. The machining time is divided in time into sensing intervals during which reference values are captured from the applied machining pulses and into machining intervals during which no reference values are captured from the applied machining pulses.

Abstract: The invention provides a method of operating a machine tool, e.g., an electrical discharge machine (4), and a machine tool system comprising a machine (4) for machining a workpiece wherein at least one of controlling, monitoring and carrying out of the machining of the workpiece is performed by a plurality of configurable modules (DRIVE; GEN; CONTROL), said modules (DRIVE; GEN; CONTROL) are arranged on the machine (4), and said modules (DRIVE; GEN; CONTROL) are so linked by a data network (6) to a node (5) for at least one of sending data to said node (5) and receiving data from said node (5).

Abstract: A method and apparatus for electrical discharge machining of a workpiece wherein an erosion pulse is applied on the tool electrode. During the time of the erosion pulse the voltage (Ue) set on the electrode is acquired, and the erosion pulse is interrupted, after an asymptotic behavior of the acquired voltage (Ue) or a value derived therefrom has been acquired. Before the interruption of the erosion pulse an increase of current may occur.

Abstract: A method and apparatus for electrical discharge machining of a workpiece wherein an erosion pulse is applied on the tool electrode. During the time of the erosion pulse the voltage (Ue) set on the electrode is acquired, and the erosion pulse is interrupted, after an asymptotic behavior of the acquired voltage (Ue) or a value derived therefrom has been acquired. Before the interruption of the erosion pulse an increase of current may occur.

Abstract: A method and apparatus for electrical discharge or electrochemical machining of workpieces, in which a machining electrode is moved relative to a workpiece, the machining is performed in cycles, and the appropriate process parameters are adjusted for machining of the current cycle with consideration of process parameters of the current cycle. To improve this method and the apparatus to the extent that improved geometric machining accuracy is made possible without time losses, stored process parameters of at least one previous cycle are also considered for adjustment of the process parameters of the current cycle.

Abstract: An electrical discharge machine with at least one wire electrode (30) in which the wire electrode (30) runs between two guide heads (10,10'). At least one, in particular, both, guide heads (10,10') are formed to be at least partially spherical. At least one of the guide heads (10,10') is seated in a manner suited for spherical rotations. Alternatively or additionally, a drive means is provided for the spherical rotation of at least one guide head (10,10'). The spatial position of the wire electrode (30), in particular, its conical angle, can be adjusted completely or essentially by subjecting the two opposing spherical guide heads (10,10') to spherical rotations and/or a modification of spacing.

Abstract: A method and an apparatus for controlling a spark erosion process between a workpiece and an electrode for instance a microdrilling electrode, so that the erosion process becomes less susceptible to a malfunction, in that at least one process parameter is measured along a first test interval of the section to be eroded, at least one control value is deduced form the measured values, and this control value is used in a subsequent erosion interval of the section to be eroded. The control value is preferably used for controlling a suitable feed rate of the electrode. The susceptibility to malfunctions is further lessened, in that a differentiation is made between mechanical and other short circuits and in that the electrode movement is controlled differently for mechanical short circuits than for other short circuits.

Abstract: A method of and a spark erosion apparatus for fine machining by spark erosion of a workpiece (2) with a wire electrode (1) eliminates very efficiently process interruptions caused by short circuits, such that at least one gap parameter is continuously monitored for the purpose of detecting a short circuit; when a short circuit is detected, the forward motion of the electrode (1) is arrested at the point (K) where the short circuit occurred; if the short circuit persists, the electrode (1) is moved away from the workpiece (2) to an intervention point (M)--in a direction perpendicular to the path (6) used for trim cutting; at the intervention point (M), one or several measures to eliminate the short circuit are executed once or several times; and after it has been detected that the short circuit is eliminated, the electrode (1) is moved back to the point (K) where the short circuit occurred, whereafter normal machining continues.

Abstract: At least two parameters (.delta., Inst) of which it is known that their variation influences the state of the spark erosion process (F, W) are fed to a logic device (5) in which a set of rules is stored. The logic device processes the parameters fed with the aid of the stored rules according to the laws of fuzzy logic, and generates at least one output signal (.epsilon.) which is fed to a controller (6) of at least one parameter, in order to match or at least approximate the currently prevailing state of the spark erosion process to a currently desired state of the spark erosion process.