A method of controlling a working gap between one or more cathodic tools and an anodic workpiece in an electrochemical material dissolution process, the method comprising: providing a cathodic tool and an anodic workpiece defining a working gap therebetween, the cathodic tool and the workpiece being at least partially immersed in a conductive electrolyte solution; providing a negative electrical potential to the cathodic tool; monitoring one or more of the electrical potential, current, current density and charge between the cathodic tool and the anode to determine the working gap between the cathodic tool and the anode; and, controlling one or more process parameters to maintain one or more of the working gap and electrochemical working conditions between the cathodic tool and anodic workpiece at a targeted value.

In a wire electric discharge machine, time from application of a voltage to a machining gap between a workpiece and a wire electrode until occurrence of electric discharge is measured as a discharge delay time, and the measured discharge delay time is integrated over a predetermined measurement period to calculate a discharge delay integrated time. Further, the number of times of the voltage application in the measurement period is counted. An average discharge delay time per voltage application in the measurement period is calculated from the discharge delay integrated time and the number of times of voltage application. The movement of the wire electrode with respect to the workpiece is controlled on the basis of the average discharge delay time.

In a wire electric discharge machine, time from application of a voltage to a machining gap between a workpiece and a wire electrode until occurrence of electric discharge is measured as a discharge delay time, and the measured discharge delay time is integrated over a predetermined measurement period to calculate a discharge delay integrated time. Further, the number of times of the voltage application in the measurement period is counted. An average discharge delay time per voltage application in the measurement period is calculated from the discharge delay integrated time and the number of times of voltage application. The movement of the wire electrode with respect to the workpiece is controlled on the basis of the average discharge delay time.

In the present invention, when performing electrical discharge machining on a workpiece via an electrical discharge machine that has an electrode holder and an electrode guide, a workpiece model and an electrode-guide model are generated in advance, an interference-start position at which the electrode-guide model starts interfering with the workpiece model when the electrode-guide model is moved towards the workpiece model along an axis line (CLa) is calculated, and a position obtained by moving the electrode-guide model a prescribed distance away from the workpiece model, starting at the interference-start position, is set as an electrode-guide position. With the electrode guide positioned at the electrode-guide position, the electrode holder is moved downwards in order to move an electrode downwards toward the workpiece surface, and electrical discharge machining is performed on the workpiece.

In the present invention, when performing electrical discharge machining on a workpiece via an electrical discharge machine that has an electrode holder and an electrode guide, a workpiece model and an electrode-guide model are generated in advance, an interference-start position at which the electrode-guide model starts interfering with the workpiece model when the electrode-guide model is moved towards the workpiece model along an axis line (CLa) is calculated, and a position obtained by moving the electrode-guide model a prescribed distance away from the workpiece model, starting at the interference-start position, is set as an electrode-guide position. With the electrode guide positioned at the electrode-guide position, the electrode holder is moved downwards in order to move an electrode downwards toward the workpiece surface, and electrical discharge machining is performed on the workpiece.

An erosion device and a corresponding method are disclosed for machining a hollow-cylindrical workpiece, wherein the device is elongated and/or formed in the manner of a tube or cylinder and is characterized in that at least two rotationally acting drives (A1, A2), each with a drive shaft (AW1, AW2), and also an erosion electrode (E), interacting with the drives (A1, A2) and formed in the manner of a ring or disc, are provided. The drives (A1, A2) and the electrode (E) are adapted in size and extent to the internal diameter of the workpiece (W) to be machined, so that the device can be introduced into the respective hollow-cylindrical workpiece (W) and can be positioned at the location respectively to be machined or the region to be machined in the workpiece (W), and the erosion electrode (E) can be pivoted or can be rotated by a coupled pivoting or rotating movement of the at least two drives (A1, A2).

A method for checking a geometry of an electric discharge machining electrode is described. The method comprises the following steps: providing a file containing a native 3D-model of the electric discharge machining electrode; providing a manufactured electric discharge machining electrode based on the native 3D-model; light scanning a set of images of the manufactured electric discharge machining electrode in different positions and generating therewith a scanned 3D-model of the manufactured electric discharge machining electrode; comparing the native 3D-model and the scanned 3D-model and generating electrode compensation coordinates for an electric discharge machining apparatus, to correct an electrode path during electric discharge machining.

A method for checking a geometry of an electric discharge machining electrode is described. The method comprises the following steps: providing a file containing a native 3D-model of the electric discharge machining electrode; providing a manufactured electric discharge machining electrode based on the native 3D-model; light scanning a set of images of the manufactured electric discharge machining electrode in different positions and generating therewith a scanned 3D-model of the manufactured electric discharge machining electrode; comparing the native 3D-model and the scanned 3D-model and generating electrode compensation coordinates for an electric discharge machining apparatus, to correct an electrode path during electric discharge machining.

A wire electrical discharge machine performs electrical discharge machining on a workpiece by applying voltage across an electrode gap formed between a wire electrode and the workpiece to thereby generate electrical discharge while moving the wire electrode relative to the workpiece along a path specified by a machining program. The wire electrical discharge machine includes: a voltage detector for detecting a gap voltage across the gap; a facing area calculation unit for calculating, as a facing area, the area of a surface of the workpiece contained within a predetermined distance from the center axis of the wire electrode; an axis feed rate determination unit for determining an axis feed rate based on the gap voltage value detected by the voltage detector, and the facing area; and a movement control unit for performing control so that the wire electrode moves relative to the workpiece at the axis feed rate.

A wire electrical discharge machine performs electrical discharge machining on a workpiece by applying voltage across an electrode gap formed between a wire electrode and the workpiece to thereby generate electrical discharge while moving the wire electrode relative to the workpiece along a path specified by a machining program. The wire electrical discharge machine includes: a voltage detector for detecting a gap voltage across the gap; a facing area calculation unit for calculating, as a facing area, the area of a surface of the workpiece contained within a predetermined distance from the center axis of the wire electrode; an axis feed rate determination unit for determining an axis feed rate based on the gap voltage value detected by the voltage detector, and the facing area; and a movement control unit for performing control so that the wire electrode moves relative to the workpiece at the axis feed rate.