Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Oki Electric Cable Co., Ltd.

Yoshikazu Ukai

Takashi Hashimoto

Koichiro Hattori

Tatsushi Sato

Seiji Satou

Yasuo Onodera

Hisashi Yamada

Akihiko Iwata

Takashi Yuzawa

Akihiro Goto

Takayuki Nakagawa

Junichi Shibata

Akihiro Suzuki

Hidetaka Miyake

Yoshikazu Tsunoda

Atsushi Taneda

Takahiro Shiozawa

Hiroatsu Kobayashi

Hiroyuki Ooguro

Toshio Nakashima

Yuki Hashimoto

Tatsushi Satou

Kouichirou Hattori

Yoichiro Kimoto

Hengbo Su

Yuji Miura

Taichirou Tamida

To provide an electrode wire for electrical discharge machining including &#x3b2;-brass and &#x3b3;-brass arranged on an outer peripheral surface of a core and a method of manufacturing the electrode wire, capable of enhancing wire connection performance and cutting down manufacturing cost while trying to increase a processing speed. The electrode wire for electrical discharge machining according to this invention comprises: an external layer including &#x3b2;-brass and &#x3b3;-brass; and a core having an undulating shape formed at a boundary surface with the external layer. The &#x3b2;-brass and the &#x3b3;-brass are arranged densely and sparsely at the boundary surface of the undulating shape. The method of manufacturing an electrode wire for electrical discharge machining according to this invention comprises: a thermal processing step of executing thermal process on a base material under a predetermined thermal processing condition, the base material having a core with a zinc-coated surface; and a wire drawing step of drawing a base wire under a predetermined wire drawing condition provided with &#x3b2;-brass and &#x3b3;-brass formed at the surface of the core by the thermal process to make the &#x3b3;-brass reach the core, thereby forming a boundary surface of the core with an external layer into an undulating shape.

Electrode wire for electrical discharge machining and method of manufacturing electrode wire for electrical discharge machining

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 high-frequency power source device includes switching element groups having a configuration in which a plurality of switching elements turned on/off cyclically are connected in parallel. One parallel connection terminal of the switching element group is connected to a positive electrode terminal of a DC power source, and one parallel connection terminal of the switching element group is connected to a negative electrode terminal of the DC power source. Respective other parallel connection terminals of the switching element groups are connected via a reactor. A pulse voltage that appears at opposite ends of the reactor due to a cyclic on/off operation of the switching element groups is applied to a load through a coaxial cable and a matching circuit.

High-frequency power source device

An electric discharge machining device that performs processing by applying a voltage pulse to space between the processing electrode and the workpiece and suitably switching the polarity of the voltage pulse attains both desired processing accuracy and desired controllability. The electric discharge machining device is provided with the first to fourth switching elements. The controlling unit that controls these switching elements, when setting a period time in which the first switching element is turned on, a period of time in which the fourth switching element is in an on-state in the same period, and, when setting a period time in which the second switching element is turned on, a period of time in which the third switching element is in an on-state in the same period so that a desired voltage pulse is applied to the space between the processing electrode and the workpiece.

Electric discharge machining device that applies a voltage pulse between a processing electrode and a workpiece

In a waveform of switching signals, which is output from a full-bridge circuit formed of four switching elements, includes a normal polarity pulse group and a reversed polarity pulse group for controlling an output timing of voltage pulses. A duty cycle of the normal polarity pulse group containing a plurality of normal polarity pulses, which apply a positive power-supply polarity to a workpiece and apply a negative power-supply polarity to a machining-purpose electrode, is configured so as to be different from a duty cycle of the reversed polarity pulse group containing a plurality of reversed polarity pulses, which apply a negative power-supply polarity to the workpiece and apply a positive power-supply polarity to the machining-purpose electrode.

Electric discharge machining apparatus and electric discarge machining method

A wire electrical discharge machining apparatus includes a unit capable of separately opening and closing each of a high impedance path and a low impedance path, a unit that sets an open/close pattern in which a combination of closing one of the feeding paths and opening another one of the feeding paths is designated for switching power feeding between the high impedance path and the low impedance path, a unit that changes pulse energy per feeding pulse in a present feeding path to reduce a difference in discharge pulse energy applied to an inter-electrode gap from a machining power supply between at a time of high-impedance-path feeding and at a time of low-impedance-path feeding, and a unit that controls opening and closing of the path open/close unit in accordance with the changed open/close pattern.

Wire electrical discharge machining apparatus

A power supply circuit for a wire electric discharge machining apparatus includes an auxiliary power supply () for generating an auxiliary discharge by applying a voltage between a workpiece () and a wire electrode (); and a plurality of main power supplies (and), a first one of which electrically connected to an upper terminal block () for connecting to an upper electrical supply point () and a second one of which electrically connected to a lower terminal block () for connecting to a lower electrical supply point (), in order to supply a main discharging current after the auxiliary discharge has occurred; wherein the power supply for the wire electric discharge machining apparatus controls the auxiliary power supply () and the plurality of main power supplies (and), to machine the workpiece (), and a first end of the auxiliary power supply is connected to the upper terminal block () and a second end thereof to the lower terminal block ().

Power supply circuit for wire electric discharge machining apparatus

A machining-energy calculating unit accumulates a discharge current value for each discharge position to calculate a machining energy in a certain time period from the present time to the past time. An energy-distribution changing unit determines the presence or absence of imbalance in the energy by obtaining a machining energy distribution in an up-down direction of the machining gap based on the machining energy, and when there is imbalance, the energy-distribution changing unit produces a new open/close pattern in which a machining energy distribution that eliminates the imbalance. Power feeding is then performed based on the new open/close pattern.

A wire-discharge machining apparatus controls a short circuit between a wire electrode and a workpiece and wire-breakage, and makes it easy to improve productivity, by performing power supply control to mix an upper-side power supply state in which a high-frequency pulse voltage is applied from an upper-side power supplying unit, a lower-side power supply state in which the high-frequency pulse voltage is applied from a lower-side power supplying unit, and a both-sides power supply state in which the high-frequency pulse voltage is applied to the wire electrode from both power supplying units in synchronization with each other during a period of electric discharge machining.

Apparatus for machining a workpiece using wire discharge including an upper and lower power supply unit

A discharge-generation control unit applies at least a preliminary-discharge voltage pulse and a main-discharge voltage pulse between a wire electrode and a work. A discharge-position determining unit determines a discharge position from results of measurement by a plurality of current measuring units. A machining-energy adjusting unit adjusts machining energy generated by the main-discharge voltage pulse based on a discharge position determined before applying the main-discharge voltage pulse, and reflects a result of the adjustment on the generation of an electric discharge by feeding the result to the discharge-generation control unit.

Wire electric discharge machining apparatus and wire electric discharge machining method

A power supply unit for wire electrical discharge machining using an ac high-frequency power supply for applying an ac high-frequency voltage between a wire electrode (1) and a workpiece () includes a high-frequency oscillation and amplification circuit () and a pulse power supply () which is an ac-high-frequency-voltage intermittently supplying unit for effecting the application of the ac high-frequency voltage between the electrode and the workpiece and a pause thereof. In wire electrical discharge machining using this power supply unit for wire electrical discharge machining, it is possible to suppress the vibration of the wire electrode (1) due tog the electrostatic force acting between the wire electrode (1) and the workpiece (), making it possible to improve the straightness accuracy of a machined surface of the workpiece () and make surface roughness small.

Power supply unit for wire electrical discharge machining and method of wire electrical discharge machining

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

Charge accumulated in a capacitor is used to provide a processing current flow between a target and an electrode. When a diode is turned on, a first dc power supply is used to provide the processing current flow between the target and the electrode. In this state, after a lapse of a predetermined time, the current supply using the first dc power supply is stopped, and an induced electromotive voltage, induced by two floating reactors, is used to rapidly drop the processing current flowing between the target and the electrode, while charging the capacitor.

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Tokyo, Japan

Yoshikazu Ukai