摘要:
A wire-discharge machining apparatus for machining a workpiece by generating discharges between a wire electrode and the workpiece. In machining, the apparatus can detect all portions where wire-breakage frequently occurs and strictly discriminate between a condition detected and a control result, achieving wire-breakage prevention. This wire-discharge machining apparatus has an evaluating device and a controller. The evaluating device measure cycles, frequencies, or ignition delay times of the discharges as a measured value, evaluates the dispersion of the measured values, and outputs an evaluation value. The controller controls machining conditions according to the evaluation value.
摘要:
A wire electric discharge machine includes storage means for storing threshold value data found from a relation between the normal electric discharge pulse energy and the electric discharge machining energy setting value corresponding to various electric discharge machining conditions; and a controller for controlling the electric discharge machining energy setting value so that the threshold value data can approach an operation point at which wire breakage occurs.
摘要:
In order to obtain wire-breakage thresholds and machining conditions for respective board thicknesses in a trial machining, a numerical control device for a wire electric discharge machining apparatus according to the present invention includes a wire-breakage-sign-signal generation means that generates a wire-breakage sign signal from machining state quantities, a wire-breakage sign detection means that outputs a machining-condition re-setting instruction and a wire-breakage threshold re-setting instruction from the wire-breakage sign signal and a wire-breakage threshold, a wire-breakage threshold setting means that sets the wire-breakage threshold according to the wire-breakage threshold re-setting instruction and a wire-breakage signal, a machining energy calculation means that calculates a machining energy from a discharge pulse count, a machining speed measurement means that measures a machining speed from position information, a board thickness calculation means that calculates a board thickness of the workpiece from the machining energy and the machining speed, a machining-condition switching means that outputs, according to a predetermined algorithm, a machining-condition switching instruction from the board thickness, the machining-condition re-setting instruction, and the wire-breakage signal, a control means that sends an oscillation instruction to a oscillator and sends a shaft feed instruction to a servo amplifier so that the machining condition is set to one determined by the machining-condition switching instruction, and a machining-condition storage means and a wire-breakage threshold storage means that store the machining condition and the wire-breakage threshold that correspond to each board thickness.
摘要:
A numerical control device for a wire electric discharge machining apparatus generates a wire-breakage sign signal, outputs a machining-condition re-setting instruction and wire-breakage threshold re-setting instruction from the wire-breakage sign signal and wire-breakage threshold, sets the wire-breakage threshold according to the wire-breakage threshold re-setting instruction and a wire-breakage signal, calculates a machining energy from a discharge pulse count, measures a machining speed from position information, calculates a board thickness of the workpiece from the machining energy and machining speed, outputs, according to a predetermined algorithm, a machining-condition switching instruction from the board thickness, the machining-condition re-setting instruction, and the wire-breakage signal, sends an oscillation instruction to a oscillator and sends a shaft feed instruction to a servo amplifier so that the machining condition is set to one determined by the machining-condition switching instruction, and stores the machining condition and wire-breakage threshold that correspond to each board thickness.
摘要:
In a power source apparatus for wire electric discharge machining capable of applying voltages of both of positive and opposite polarities to a gap between a wire electrode (1a) and a workpiece (2), there is provided a controller (14) for applying a first voltage pulse to the gap for predetermined time T1 and then applying a second voltage pulse of a polarity opposite to the first voltage pulse for predetermined time T2a necessary for the gap voltage to become a predetermined voltage lower than or equal to a voltage Va capable of starting an electric discharge after a lapse of predetermined time t set for prevention of breakage of a switch. The apparatus is used in machining for performing at least two machining operations selected from machining in machining liquid, machining in mist and machining in gas. Wire electric discharge machining with high reliability suitable for high-accurate machining can be implemented.
摘要:
In an electric discharge machining power supply system that can apply a voltage of both positive and negative polarities between an electrode and a workpiece, there is provided a controller that applies a first voltage pulse between the electrodes for a predetermined time T1, and then applies a second voltage pulse having a polarity opposite to the first voltage pulse for a predetermined time T2a required until the voltage between the electrodes is lowered to a predetermined voltage that is less than an electric discharge starting voltage Va, after a predetermined time t that is set to prevent breakdown of a switching circuit has lapsed. In electric discharge machining using this electric discharge machining power supply system, the stable machining having high machining quality can be accomplished by causing a remaining voltage between the electrodes to fall down quickly and remove.
摘要:
A method of wire electric discharge machining by which an electric discharge is generated in a gap between a wire electrode (1a) and a workpiece (2) so that the workpiece (2) is machined, includes the steps of: a first step in which electric discharge machining is conducted in a dielectric liquid (4a); a second step in which electric discharge machining is conducted in mist (7); and a third step in which electric discharge machining is conducted in gas (8), such that the machining process is changed over when straightness of the workpiece (2) becomes a predetermined value. It is possible to provide a method of wire electric discharge machining, the productivity of which is high, suitable for highly accurate machining.
摘要:
A wire electrical discharge machine having an upper wire guide and a lower wire guide through which a wire electrode is passed and which have therein channels for the working fluid to flow therethrough, including: ajet nozzle which is engaged with and fixed to an outer peripheral surface of a distal end portion of the upper wire guide, and is adapted to guide the wire electrode to a hole in the lower wire guide through use of the fluid; a working fluid nozzle for covering the jet nozzle and having a through hole in a central portion thereof and a collar portion in a periphery thereof; a retaining plate for fixing an outer peripheral portion of the working fluid nozzle including the collar portion, and the retaining plate having a channel for supplying and discharging the fluid; and a sealed space portion which is disposed between the collar portion of the working fluid nozzle and the retaining plate and expands and contracts due to the fluid which flows in or out through the channel.
摘要:
A workpiece is machined by consecutively performing at least two of machining in a machining solution, machining in a mist and machining in a gas, such that at a point of time before the start of machining, except for the machining conducted in the machining solution, and a point of time after the operation of an automatic wire connecting device for conducting an automatic wire connection while the wire electrode is being held by a water column, the machining solution nozzles, can change from supplying the machining solution to supplying the pressurized gas. By the machining solution nozzles, liquid of the machining solution adhering to the workpiece and liquid adhering to the machining solution nozzle which is capable of dripping onto a face to be machined of the workpiece, are removed.
摘要:
A power supply apparatus for electric discharge machining is provided with a current loop including a diode, which is supplied with a forward current at the same time a voltage for generating a discharge is output or before it; and a resistor. Supply of forward current to the diode is blocked the moment a discharge is generated. By doing so, a reverse recovery current of the diode is supplied in a gap between an electrode and a workpiece to be machined.