Abstract: An electric discharge machining apparatus capable of precisely detecting the electric discharge in a case of performing machining by minute machining energy such as in finish machining. A voltage is applied between a tool electrode and a workpiece by repeating ON/OFF of a switching element to charge a stray capacitance between the electrodes to cause electric discharge between the electrodes by the charged voltage. The electric discharge between the electrodes in the electric discharge machining by the minute machining energy is detected. The current between the electrodes is detected by integrating an output of a sensor coil. An offset component superposed in the output of the integrator by a low-pass filter is extracted. The extracted offset component is eliminated from the output of the integrator by a differential amplifier. An output of the differential amplifier is compared with a reference value to detect the electric discharge.

Abstract: An apparatus has a green compact electrode including a material of a coating formed on a workpiece by a discharge, a power source for supplying a first voltage, a voltage detector for detecting a voltage between the workpiece and the electrode, and a pulse current generator for generating and outputting a pulse current from the first voltage, and for cutting off the output when a predetermined period of time has passed after the voltage is detected to be less than a detection voltage. The pulse current is supplied between the workpiece and the electrode, and the detection voltage is less than the first voltage by 5% to 20% of the first voltage.

Abstract: An electric discharge machining apparatus comprises a power supply (5) for applying a voltage to a work gap formed between a tool electrode (E) and the workpiece (W) and a motor (7) that moves the tool electrode relative to the workpiece. An electric discharges counter (45) counts a number of electric discharge occurrences within a specified period (Td1) and generating a first count. A gap controller (48) multiplies the first count by a gain to generate position command or speed command for motor drive. An inversion counter (42) counts a number of inversions of the gap voltage upwards or downwards within a second specified period (Td2) and generating a second count. An electric discharge discriminator (44) discriminates the occurrence of electric discharge when the second count reaches a set value.

Abstract: A programmed electrode wear compensation device and method for 3D EDM scanning apparatus has a compensation device which receives raw data about a working path of a working apparatus from a CAD/CAM device, calculates therefrom compensated data which take into account electrode wear and transmits the compensated data to a control device which controls the working apparatus, so that smoothness and shape of a machined surface are maintained during electric discharge.

Abstract: A positioning apparatus for an electrical discharge machine includes: a power supply 106 for applying a pulse voltage between an electrode 101 and a workpiece 102; a discharge detecting means 1108 for detecting the occurrence of electrical discharge between the electrode 101 and the workpiece 102; and a means for generating a positioning completion signal on the basis of a detection signal from the discharge detecting means 1108.

Abstract: A method and device for monitoring the condition of an electrode in an electro-discharge machine are disclosed. The device includes an electrode detector operable to produce a position signal indicative of the position of an end region of the electrode in the nose-guide, and a signal processing unit connected to receive a position signal from the electrode detector and operable to determine from the position signal when retraction of the electrode into the nose-guide has occurred. The method monitors the position of the end region of the electrode and determines when retraction of the electrode has occurred.

Abstract: Spark erosion system for removing connection elements from a structure (W, 60), having a drill head (3) [(4)?], a rotational drive (10) by means of which a tool is caused to rotate, a positioning system (15) for moving the tool as well as a process control (48) for controlling the overall system, the system comprising an energy unit (30) and an electric circuit, and in that, furthermore, the tool is a tube electrode (5) through whose interior (5a) a dielectric can be guided to the surface (61a) of the connection element (61) to be detached, which surface (61a) faces the interior (7a), in order to cause a voltage between the tube electrode (5) and the connection element (61) to be detached, for implementing a spark erosion.

Abstract: A manual feeding device in a wire electric discharge machine in which selection between a jog feed and a step feed is made automatically without mode change. When an axis motion key is pressed, a timer measures the time for which the key is pressed. When the key is turned off before the time measured reaches a predetermined length of time on the basis of which switching to the jog feed is made, the step feed is performed, so that the axis is moved by a predetermined amount. When the key is pressed for the length of time predetermined for switching to the jog feed, the jog feed is started, so that the axis is moved at a low speed. Further, when the key is pressed for a length of time predetermined for switching to a medium speed, the feed axis is moved at the medium speed, and when the key is pressed for a length of time predetermined for switching to a high speed, the axis is moved at the high speed.

Abstract: Set feed speed is lowered when a short circuit is detected in a range within which machining is unstable, the range starting from the point at which discharge is detected after machining starts from a machining start point, thus control is carried our according to a machining rate, thereby preventing successive occurrence of short circuits. When machining proceeds beyond the unstable range, the lowered feed speed is returned to the normal feed speed.

Abstract: A sinker electric discharge machine jump control device for reciprocating a tool electrode along a Z-axis with respect to a workpiece using a servo motor in order to expel contaminated fluid from a work gap. The jump control device includes a commanded current generator, the current generator generating a commanded current for the servo motor, and a commanded velocity generator, the velocity generator dividing a locus of a jump stroke into a plurality of segments and generating a commanded velocity for each of the plurality of segments. Additionally, the jump control device includes a velocity override calculator, the calculator generating a velocity override according to the commanded current, and a commanded velocity modifying device, the modifying device modifying the commanded velocity according to the velocity override during the jump stroke.

Abstract: There is provided a controller(11) structured in such a manner that a signal of ON/OFF of electric power of the temperature control unit (7) is received by the signal receiving section (12), according to ON/OFF of the received signal of the signal receiving section (12), the correction calculating section (13) calculates an amount of correction, this amount of correction is sent to the amplifier output command section (14), and the amplifier output command section (14) sends an axial feed operation command of the amount of correction to the drive unit(15). Correction of the thermal displacement of the machine body generated by a change in the temperature of the machining solution can be easily, effectively conducted without using a specific device, and the machining accuracy can be enhanced.

Abstract: The number of electric discharge pulses is detected every given period. A deviation between the detected number and a target number of electric discharge pulses is obtained. Based on the obtained deviation, a correction value for the correction of a machining path in a direction normal to the machining path is calculated, whereby a corrected path is obtained. A wire electrode is moved relatively to a workpiece along the corrected path.

Abstract: In an electric discharge machine, wherein electric power is supplied between an electrode and a workpiece to machine the workpiece, a jumping motion is performed to temporarily increase a distance between the electrode and the workpiece. The electric discharge machine includes a detector for detecting a machining reaction force; a setting unit for setting a specified value of the machining reaction force; a comparator for comparing a detected value of the machining reaction force with a specified value of the machining reaction force; and a changing unit for changing a locus of the jumping motion so that the machining reaction force can be reduced if the comparator finds that the detected value of the machining reaction force is greater than the specified value of the machining reaction force.

Abstract: An electric sparking drill and a method for using the same to drill a hole in a workpiece where at least one of a voltage applied to an electrode, the conductivity of a liquid applied between the electrode and the workpiece during drilling, and a gap between the electrode and the workpiece are controlled to create the desired hole in the workpiece. The electric sparking drill and a method for using the same to drill a hole in a workpiece also improve the hole operation and/or the quality of the hole made by operating at the arcing voltage, including a touch stop function, including a sacrificial electrode, and/or including a guide member function.

Abstract: An electric discharge machining apparatus for supplying machining electric power to a gap between an electrode (1) and a workpiece (2). The apparatus includes a gap dimension detection device (8) for detecting a dimension of the gap, a gap average voltage detection device (11) for detecting an average voltage of the gap, a gap dimension correction device (13) for correcting the dimension of the gap, and a gap dimension correction starting device (12) for starting the gap dimension correction device (13) when a first comparison between a detected gap dimension and a predetermined allowable value and a second comparison between a detected gap average voltage and a predetermined reference average voltage are made and the gap dimension detected by the first comparison is larger than the predetermined allowable value and the gap average voltage detected by the second comparison is smaller than the predetermined reference average voltage.

Abstract: An electrical discharge machining (EDM) apparatus includes a plurality of machining heads, at least one EDM control system, and a plurality of programmable servo drives. Each one of the programmable servo drives is connected to the EDM control system and to a respective one of the plurality of machining heads. The programmable servo drives receive a velocity command from the EDM control system and feed a control signal to a respective one of the plurality of machining heads to control electrode positioning.

Abstract: In a wire cut electric discharge machine, a correction block is inserted into a corner of a movement path where the wire electrode is moved by the electrode moving device. The correction block does not correspond to the contour of the workpiece to be machined. When it is necessary to change machining condition such as the voltage to be applied to the wire electrode before and after the corner, a changing position to change the machining condition is set on the correction block.

Abstract: Spark erosion system for removing connection elements from a structure (W, 60), having a drill head (3) [(4)?], a rotational drive (10) by means of which a tool is caused to rotate, a positioning system (15) for moving the tool as well as a process control (48) for controlling the overall system, the system comprising an energy unit (30) and an electric circuit, and in that, furthermore, the tool is a tube electrode (5) through whose interior (5a) a dielectric can be guided to the surface (61a) of the connection element (61) to be detached, which surface (61a) faces the interior (7a), in order to cause a voltage between the tube electrode (5) and the connection element (61) to be detached, for implementing a spark erosion.

Abstract: An electric discharge machine in which electric power for machining is supplied by a machining electric power supply means (13) to between an electrode (1) and a workpiece (2) provided in a machining solution (3), electric discharge machining is conducted on the workpiece (2) while the electrode (1) and the workpiece (2) are relatively being moved by a positioning means, and a jumping motion is conducted, the electric discharge machine comprising: a machining reaction force detecting means (20, 21, 22) for detecting a machining reaction force; a machining reaction force specified value setting means (23) for setting a specified value of the machining reaction force; a machining reaction force comparing means (24) for comparing a detected value of the machining reaction force, which is detected by the machining reaction force detecting means (20, 21, 22), with a specified value of the machining reaction force which is set by the machining reaction force specified value setting means (23); and a motion locus ch

Abstract: In a micro electro discharge machining method and apparatus, the shapes of minute holes are transferred to a tool electrode through a plate electrode serving as an intermediate electrode, and a workpiece is machined using the tool electrode. As a result, the time for machining is reduced. During the electro discharge machining process, the relative distance between the tool electrode and the plate electrode or the workpiece is changed at a prescribed frequency and discharge pulse output is controlled in synchronization with the change in the relative distance between the tool electrode and the plate electrode or the workpiece, so that high precision machining is enabled.

Abstract: There is provided a control means (11) structured in such a manner that a signal of ON/OFF of electric power of the temperature control unit (7) is received by the signal receiving section (12), according to ON/OFF of the received signal of the signal receiving section (12), the correction calculating section (13) calculates an amount of correction, this amount of correction is sent to the amplifier output command section (14), and the amplifier output command section (14) sends an axial feed operation command of the amount of correction to the drive means (15). Correction of the thermal displacement of the machine body generated by a change in the temperature of the machining solution can be easily, effectively conducted without using a specific device, and the machining accuracy can be enhanced.

Abstract: The wire electric-discharge machining apparatus is provided with an inter-pole voltage correction unit 109 which corrects a voltage corresponding to an inter-pole voltage according to a correction coefficient which increases with an elongation of discharge stop time. A corrected voltage corresponding to the inter-pole voltage output from the inter-pole voltage correction unit 109 is given to a control unit 106 to allow a wire electrode 101 and a workpiece 102 to relatively move according to the corrected voltage corresponding to the inter-pole voltage.

Abstract: An automatic breakthrough detection device for drilling electric discharge machine is provided. The automatic breakthrough detection device utilizing the facts of the variations of high frequency spectrum components of the provided discharge voltage and the variation of servo-feed-rate of the electrode as drilling discharge. The device includes a high frequency spectrum detecting analyzer to produce digital logic determining signals and a breakthrough judging logic device to judge the breakthrough by the electrode on the workpiece. Accordingly, the drilling electric discharge machine automatically adjusts the discharge parameters and the electrode withdrawals from the drilled hole and continues the next drilling hole on the workpiece. The present invention also provides a method of the same.

Abstract: Electrical discharge machines are disclosed that are capable of a relatively wide range of flexibility and range of motion for performing electrical discharge operations. The electrical discharge machine herein can optionally comprise up to, and in excess of six axes of motion to adjust the electrode relative to the workpiece. To effectively remove the swarf that is generated during electroerosion operations, a primary flushing system and an optional auxiliary flushing system are provided. The auxiliary flushing system is used to direct dielectric fluid towards the workpiece external to the electrode. Further, methods of performing high speed electrical discharge machining operations are disclosed, including methods for establishing the zero set conditions that indicate initiation of the electroerosion process based upon a detection of dither on the electrode travel.

Abstract: A jump control apparatus for an electric discharge machine ensuring high machining precision while reducing machining time by removing sludge speedily, regardless of differences in shape among workpieces, includes a feed control unit for controlling a vertical position of an electrode relative to a workpiece, a jump condition estimating unit for estimating jump conditions for the electrode for removing the sludge between the electrode and the workpiece during machining. The jump conditions generated are input to the feed control unit. The apparatus includes an input unit for inputting machining conditions relating to the jump conditions in precedence to machining, and a numerical control unit for determining various parameters in dependence on the machining conditions. The parameters are input to the jump condition estimating unit for estimating the jump conditions through feed-forward control using the parameters.

Abstract: An electrical discharge machining (EDM) apparatus includes a plurality of machining heads, at least one EDM control system, and a plurality of programmable servo drives. Each one of the programmable servo drives is connected to the EDM control system and to a respective one of the plurality of machining heads. The programmable servo drives receive a velocity command from the EDM control system and feed a control signal to a respective one of the plurality of machining heads to control electrode positioning.

Abstract: Devices and methods are disclosed for the contactless detection of a bar-shaped or wire-shaped processing electrode of a machine tool such as a spark erosion machine. The detection is based on measuring an impedance change in the measuring area, which is caused by the processing electrode moving through the measuring area. The impedance change is measured by one or more measuring electrodes disposed in the measuring area.

Abstract: The present invention provides electrical discharge machines that are capable of a relatively wide range of flexibility and range of motion for performing electrical discharge operations. For example, an electrical discharge machine according to at least one embodiment of the present invention can optionally comprise up to, and in excess of six axes of motion. To effectively remove the swarf that is generated during electroerosion operations, the present invention optionally provides both a primary and an auxiliary flushing system. The auxiliary flushing system is used to direct dielectric fluid towards the workpiece external to the electrode. The present invention also provides methods of performing high speed electrical discharge machining operations including determining the zero set conditions that indicate initiation of the electroerosion process.

Abstract: In an electric discharge machining apparatus for performing machining while relatively rocking an electrode (18) and a workpiece (W) in a plane vertical to a machining feed direction, there is provided an electric discharge state detection device (20) for detecting an electric discharge state by detecting a short-circuit frequency between the electrode and the workpiece, a defective electric discharge frequency and a position of the electrode, and a rocking function setting device (23) for setting parameters about a rocking function according to the electric discharge state detected by the electric discharge state detection device (20). A parameter setting about a rocking function according to the detected electric discharge state is automatically made without compelling an operator to make the parameter setting about the rocking function, and improvement in machining efficiency and stabilization of the machining can be achieved.

Abstract: An electroerosion machining device to machine a piece (14) by milling successive layers includes a member (30) to drive in rotation an electrode-tool (31) of tubular shape and a digital control unit (CN) to control the three-dimensional movement (x, y, z) between the electrode-tool and the piece (14). A regulation module (MR) is adapted to simulate the longitudinal wear of the electrode-tool and to compensate it along its path. According to the type of geometric configuration between the electrode-tool and the piece, namely the presence or absence of an opening below the electrode-tool and the presence or absence of one or two walls, different values of longitudinal wear are provided and transmitted to the digital control unit (CN). There is thus obtained a high precision and planarity of machining.

Abstract: An electric sparking drill and a method for using the same to drill a hole in a workpiece where at least one of a voltage applied to an electrode, the conductivity of a liquid applied between the electrode and the workpiece during drilling, and a gap between the electrode and the workpiece are controlled to create the desired hole in the workpiece. The electric sparking drill and a method for using the same to drill a hole in a workpiece also improve the hole operation and/or the quality of the hole made by operating at the arcing voltage, including a touch stop function, including a sacrificial electrode, and/or including a guide member function.

Abstract: An electric discharge machining device including an interelectrode servo control unit for controlling an interelectrode distance between an electrode and an object while applying a voltage across the electrode and the object, and a jump control unit for controlling a jump operation in which the interelectrode distance is temporarily increased at time intervals or in response to a machining state jump control unit includes a jump locus generation unit for generating a smooth command locus having a frequency component in a frequency range. The jump control unit controls the jump operation by using a smooth command locus generated by the jump locus generation unit.

Abstract: A jump control apparatus for an electric discharge machine capable of ensuring high machining precision while reducing machining time by removing sludge speedily regardless of differences in shape among workpieces includes a feed control unit (7) for controlling a vertical position of an electrode (1) relative to a workpiece (2), a jump condition estimating unit (8) for estimating jump conditions for the electrode (1) for removing the sludge occurring between the electrode (1) and the workpiece (2) during machining. The jump conditions generated are inputted to the feed control unit (7). The apparatus includes an input unit (10) for inputting machining conditions relating to the jump conditions in precedence to machining, and a numerical control unit (11) for determining various parameters in dependence on the machining conditions. The parameters are inputted to the jump condition estimating unit (8)for estimating the jump conditions through a feed-forward control performed by using the parameters.

Abstract: A detected value indicating a machining state is filtered and a machining gap between an electrode and a workpiece is adjusted by using a control variable obtained through the filtering. Therefore, machining speed can be improved by maintaining a stable machining state through suppression of a disturbance in a gap distance control system due to eccentricity of an electrode, due to fluctuations in electric characteristics at feeding brush sections, and due to mechanical resonance of the electrode driving system.

Abstract: An electroerosion machining device to machine a piece (14) by milling successive layers, comprises a member (30) to drive in rotation an electrode-tool (31) of tubular shape and a digital control unit (CN) to control the three-dimensional movement (x, y, z) between the electrode-tool and the piece (14). A regulation module (MR) is adapted to simulate the longitudinal wear of the electrode-tool and to compensate it along its path. According to the type of geometric configuration between the electrode-tool and the piece, namely the presence or absence of an opening below the electrode-tool and the presence or absence of one or two walls, different values of longitudinal wear are provided and transmitted to the digital control unit (CN). There is thus obtained a high precision and planarity of machining.

Abstract: A workpiece 7 is held on a table and moved in X and Y directions relative to a tool electrode 4, which is displaceable in a direction orthogonal to the X and Y directions. The position of the workpiece 7 to which it should be moved is calculated based on the current positional data of the tool electrode 4 relative to the workpiece 7 and the machining data. The workpiece 7 is moved continuously in X and Y directions to the thus obtained position in accordance with the shape being machined.

Abstract: An electro discharge machining apparatus comprises a first holder for holding a workpiece to be subjected to electro discharge machining, an electrode provided opposing the workpiece held by the first holder, a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode, a power source for applying a voltage to the capacitor, a switching element provided between the capacitor, and at least one of the electrode, the workpiece and the power source, a switch controller for controlling on and off of the switching element, a current detecting element for detecting a current flowing between the workpiece and the electrode, and a control unit for, based on the current detected by the current detecting element, judging whether or not a short circuit occurs between the workpiece and the electrode.

Abstract: The invention provides an apparatus and method for detecting an out-of-line electrode prior to the start of an electrical discharge machining (EDM) process. The invention involves positioning an electrically conductive test component in an accurately defined location relative to a workpiece. The test component has a test hole of a size and shape corresponding to the hole to be drilled in the workpiece by an electrode of an EDM machine. The electrode is then inserted into the test hole. If the electrode is correctly aligned then it will not contact the test component and no electrically conductive path will be formed between the electrode and the test component. If such contact is detected then the electrode is misaligned and the EDM process is stopped. This sequence is repeated immediately before the commencement of drilling of each hole in the workpiece.

Abstract: An error signal is obtained from a reference value and a value indicating a detected state in machining, a first controlled variable is obtained by adding a value obtained by multiplying the error signal by a proportion gain to a value obtained by multiplying the error signal by a first integration gain, a second controlled variable is obtained by multiplying an instruction value by a second integration gain for integration, and a value obtained by adding the first controlled variable to the second controlled variable and multiplying the sum by a machining trajectory vector is used as a controlled variable for a driving unit for adjusting a distance between an electrode and a workpiece in discharge machining. Therefore, it is possible to realize a discharge machining control method and apparatus in which the machining speed can be improved by always maintaining the discharge machining process in an optimal state.

Abstract: The main spindle (1A) for the main spindle device of a diesinker electric discharge machine is connected to a high rotor inertia, high output servo motor (15) without passing through a speed reducer; the servo motor (15) is equipped with a high resolution encoder (14). A main spindle rotation speed detection signal is detected by the encoder (14) when the main spindle (1A) is rotating in the high speed mode, and a main spindle angle position and rotation speed detection signal are detected when the main spindle (1A) is being angle divided, and these signals are fed back to the servo motor (15) motor driver (16). High speed rotational control and angle position precision angle division control are accomplished by a single servo motor and a single encoder.

Abstract: Disclosed is a wire electric discharge machining apparatus comprising a wire-driving system for feeding a wire electrode while opposing it to a workpiece, and a power supply unit for supplying electric power to the wire electrode, wherein electric discharge is effected between the wire electrode and the workpiece to machine the workpiece to have an arbitrary shape. The wire electrode is allowed to approach the workpiece to effect the electric discharge between the wire electrode and the workpiece so that the workpiece is machined to have an arbitrary shape, while a suction mechanism is used to remove undesirable matters including sludge together with a working fluid via cylindrical members from holes formed in the workpiece.

Abstract: An apparatus for electrochemically machining of a workpiece by means of an electrode has an actuator for setting a gap between the electrode and the workpiece. The apparatus further has a channel for flushing the gap with an electrolyte and a container for containing the electrolyte. Power cords and are provided for feeding an electric current I supplied by a power supply through the electrolyte in the gap. Near the gap an antenna is provided to pick up electromagnetic waves radiated from the gap. The antenna is connected to a band-pass filter which passes signals in a frequency band of 40 to 100 MHz to a level detector. The level detector compares the amplitude of the filtered signal with a threshold value and supplies a stop signal to the control unit when the amplitude exceeds the threshold value. The control unit is programmed to open a switch in the power supply in response to the stop signal.

Abstract: Separately from an electrode jumping operation (an amount of rise of a first electrode jump (22)) aimed at discharging machining debris produced during electrical discharge machining, an electrode jumping operation (an amount of rise of a second electrode jump (23)) is inserted for which is set an amount of rise of jump with which balls or rollers used on a sliding portion of a mechanically driving part undergo one revolution or more. Further, in a case where an abnormality of a lubricant supplying unit (101) is detected, as for a program being continued, machining is stopped after the termination of the program, or machining is stopped after continuing the program within a fixed time duration, or a program other than for machining operation is made executable.

Abstract: A method and a device for the controlled withdrawal movement of a machining electrode in an erosion device wherein, in the case of a process malfunction, the machining electrode is moved backward along the previously traveled machining path (B) (first way of withdrawal) and along a withdrawal vector (RV) defined in relation to the machining path (B) (second way of withdrawal). In order to quickly eliminate the process malfunction and at the same time reduce the risk that the machining electrode will hit the work piece surfaces during the withdrawal movement, the machining electrode is moved backward simultaneously along both ways of withdrawal, and the direction of the withdrawal vector (RV) at each point is adapted to the previously traveled machining path (B).

Abstract: A method and apparatus for controlling the position and power of electrodes in an electric-discharge texturing (EDT) machine for texturing a roll includes an actuator for moving an electrode away from and towards a roll to be textured to maintain a desired spacing between the electrode and the roll. The actuator is controlled with a different gain depending upon whether the electrode is to be moved towards or away from the roll. A power source applies a voltage to the electrode for promoting a spark between the electrode and the roll to remove particles from the roll. The power source is controlled to apply the voltage to the electrode until a spark is initiated and then maintains the voltage for a selected time duration after spark initiation to provide a spark having the selected time duration. The power source is further controlled such that voltages applied to a plurality of electrodes are sequenced in a selected fashion.

Abstract: EDM according to the present invention involves an intermttent type of operation between erosion pulses and measurement pulses in order to circumvent an interfering self-control effect of an electrode during fine machining. To achieve shorter processing times, higher precision and better reproducibility, the method and apparatus determine with an electrical measurement the amount that an electrode is in contact with a workpiece during a measurement time that erosion has been interrupted. A pulse duty factor is then obtained from the contact amount to control further processing via, for example, the duration of the erosion pulses.

Abstract: In a three dimensional generic electric discharge machining (EDM) apparatus the positionable driver assembly (4) houses a discharge electrode (1) that is in the form of a continuous wire, exposing only a predetermined length, the working portion, of that wire for discharge machining. Additional portions of that wire are incrementally advanced (5) from the housing as needed. In one embodiment, that need arises from electrode erosion, and, as an incremental portion of the electrode's working portion is eroded away, an additional increment of wire is advanced from the housing to restore the working portion to the desired length.

Abstract: Electrode tools for electroerosion (EDM) where a cavity or a relief is machined by hollowing out the part at great speed and in successive layers or slices by means of a rotating electrode tool of a simple shape which is independent of the cavity to be eroded, called “EDM slices milling”.

Abstract: An apparatus and method is provided for use on an electric discharging machine to enhance the working efficiency of the electric discharging machine. The apparatus and method are directed to the control of the ignition delay time of the ignition voltage used to ignite the electric discharges applied to the workpiece for machining the workpiece. The apparatus and method are directed to the objective of making the duty factor as close to unity as possible. The apparatus and method are characterized in that the average discharge voltage is computed by the CNC (computer numerical control) unit instead of an analog voltage averaging circuit as in the prior art. The average discharge voltage is then used for the determination of the average ignition delay time to accordingly adjust the gain of the servo control loop of the discharging. The electric discharging machine then detects the ignition delay time to accordingly adjust the magnitude of the ignition voltage and the length of the discharge off-time.