Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Kawasaki Steel Corporation

Seiji Satou

Toshio Moro

Yoshikazu Ukai

Akihiro Goto

Tatsushi Sato

Hiroatsu Kobayashi

Hiroyuki Ooguro

Akihiko Iwata

Takuji Magara

Akihiro Suzuki

Hisashi Yamada

Hidetaka Miyake

Yasuo Onodera

Takahiro Shiozawa

Toru Inoue

Jiro Tateno

Masaharu Hashimoto

Hiroyuki Ohguro

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.

Numerical control device, wire electric discharge machining apparatus using the same, and wire electric discharge machining method using the same

A power supply device for electric discharge machining includes a switching circuit that supplies a discharge pulse current to an inter-electrode portion that is a portion between an electrode and a workpiece serving as another electrode arranged to be opposed to the electrode at a predetermined interval; and a pulse-width control unit that generates a control pulse signal of a predetermined pulse width in response to a detection signal for starting a discharge at the inter-electrode portion. The switching circuit includes a switching circuit including a switching element suitable for a high-speed operation and a switching circuit including a switching element suitable for a low-speed operation, and receives the control pulse signal in parallel.

Discharge-processing power source device

Machining electrical power supply device for wire electrical discharge machining. Includes an electrical discharge state distinguishing circuit () for distinguishing at least two inter-electrode states, including electrical shorting and normal electrical discharge, between a wire electrode (E) and a workpiece (W), and an inter-electrode current waveform control means for supplying, and for switching between supply of, a triangular wave and a trapezoidal wave current to the electrodes. According to the inter-electrode state distinguished by the electrical discharge state distinguishing circuit (), in cases where the inter-electrode state is that of electrical shorting (Y), the inter-electrode current waveform control means supplies a triangular wave current (I) to the electrodes, and in cases where the inter-electrode state is that of normal electrical discharge (Y), it supplies a trapezoidal wave current (I) to the electrodes. Breakage of the wire electrode (E) can be avoided and machining speed can be improved.

Machining power supply for wire electrical discharge machine

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.

Wire electric discharge machine with stored discharge energy threshold function

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 ( ) and a workpiece ( ), there is provided a controller ( ) for applying a first voltage pulse to the gap for predetermined time T and then applying a second voltage pulse of a polarity opposite to the first voltage pulse for predetermined time T 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.

Power supply for wire electric discharge machining

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 T , and then applies a second voltage pulse having a polarity opposite to the first voltage pulse for a predetermined time T 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.

Power supply system for applying a voltage of both positive and negative polarities in electric discharge machining

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.

Wire electric discharge machining method and wire electric discharge machine utilizing pressurized gas for removing machining solution

A method of wire electric discharge machining by which an electric discharge is generated in a gap between a wire electrode ( ) and a workpiece ( ) so that the workpiece ( ) is machined, includes the steps of: a first step in which electric discharge machining is conducted in a dielectric liquid ( ); a second step in which electric discharge machining is conducted in mist ( ); and a third step in which electric discharge machining is conducted in gas ( ), such that the machining process is changed over when straightness of the workpiece ( ) 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.

Method of electrodischarge wire machining

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.

Apparatus for electric discharge machining

The wire electric discharge machining apparatus includes apparatus or generating a discharge in a gap between a wire electrode ( ) and a machining subject ( ) to machine the machining subject. A gas supplying unit ( ) supplies a pressurized gas in the gap between the wire electrode and the machining subject. This wire electric discharge machining apparatus has a high productivity, and it is suitable for high-precision machining.

Method of and apparatus for wire electric discharge machining capable of machining the machining subject coarsely in a dielectric fluid and finely in a gaseous environment

A wire electrical discharge machining apparatus provided with: a nozzle for spraying and supplying machining liquid, the nozzle being supported so that a state of the nozzle is switched over from a contact state with a work piece to a non-contact state with the work piece, and vice versa; a spring acting on the nozzle in a direction to make the nozzle move away from the work piece; a pump for changing and controlling a hydraulic pressure of the machining liquid; and electrical conduction switch-over apparatus by which power supply to the work piece is switched over from the nozzle of a conductor to apparatus other than the nozzle, and vice versa, such that the hydraulic pressure of the machining liquid during electric discharge machining is changed and controlled by the pump so that the state of the nozzle is switched over from the contact state to the non-contact state.

Wire electric discharge machine

Pieces of information such as work program information, work profile and work condition, which are necessary for an operator to grasp a state of a machine tool, a change in the work voltage necessary for an operator to grasp a state of working a workpiece, pieces of work monitoring information such as a change in the work speed, and measured data of the workpiece are display on a list by a display device of a numerically controlling device for each session of work.

Numerically controlling device for electrical discharge machine

In a wire electric discharge machine in which the processing liquid exists between a wire electrode and a work piece , and the work piece is processed while the discharge is being generated, the wire electric discharge machine has a jetting nozzle to jet the processing liquid to the work piece , and a wire guide portion to flow the processing liquid to the jetting nozzle and to guide the wire electrode into a bored hole, and the wire guide portion has the first passage to flow the processing liquid into the jetting nozzle, and the second passage to convert the direction of the processing liquid to be flowed into the first passage

An upper guide and a lower guide are respectively disposed above and below a workpiece. The upper guide and the lower guide respectively has wire guides for guiding the wire electrode. A pair of electric supply dies are respectively provided in the upper guide and the lower guide and are adapted to come into contact with and energize the wire electrode. An internal nozzle and an external nozzle are provided in at least one of the upper guide and the lower guide. A first piping system supplies the working fluid to the internal nozzle and a second piping system supplies the working fluid to the external nozzle, where the second piping system is independent of the first piping system. The working fluid having lower temperature and higher pressure than the working fluid jetted out and supplied from the external nozzle is jetted out and supplied to the workpiece from the internal nozzle.

Wire electrical discharge machining apparatus

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.

Growing community of inventors

Tokyo, Japan

Seiji Satou