Abstract: A corrosion preventing apparatus including: a water purifying part that includes a hydrogen-ion form resin and a hydroxy-ion form resin; an anticorrosive part that includes a cation form resin and an anion form resin having anticorrosive ions supported thereon; a conductivity measuring part that measures a measured value of conductivity of a machining liquid; and a control part that controls a flow of the machining liquid to the water purifying part and the anticorrosive part on the basis of the conductivity measuring part; wherein the control part performs control on the basis of predetermined first and second conductivities and the measured value measured by the conductivity measuring part.

Abstract: 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.

Abstract: A wire electric discharge machining apparatus is constructed in such a manner as to include: a wire electrode having a plurality of cutting wire portions that are separated from one another in parallel and are opposed to a workpiece; a machining power supply that generates a pulsed machining voltage; a plurality of power feed contact units that are electrically connected to the cutting wire portions and apply the machining voltage between the cutting wire portions and the workpiece; and a nozzle that ejects machining liquid from an ejection opening toward an electrode gap along the cutting wire portions.

Abstract: A wire electric discharge machining apparatus includes guide rollers and a single electrode wire that is wrapped around each of the guide rollers to form cut wire portions that are spaced from one another between pairs of the guide rollers. A processing power supply feeds electric power to the individual cut wire portions through a power feed element. A high frequency insulator includes wound coils of the electrode wire that are located between adjacent cut wire portions, and cores which close respective magnetic circuits of the individual coils. The magnetic circuits are magnetically insulated from one another. The power feed element is arranged between the individual cut wire portions and the individual coils, and the individual cut wire portions are insulated from one another at high frequencies by the individual coils. Voltages are impressed on the individual cut wire portions independently, so discharges can be generated simultaneously, in parallel.

Abstract: A wire electric discharge machining apparatus includes guide rollers and a single electrode wire that is wrapped around each of the guide rollers to form cut wire portions that are spaced from one another between pairs of the guide rollers. A processing power supply feeds electric power to the individual cut wire portions through a power feed element. A high frequency insulator includes wound coils of the electrode wire that are located between adjacent cut wire portions, and cores which close respective magnetic circuits of the individual coils. The magnetic circuits are magnetically insulated from one another. The power feed element is arranged between the individual cut wire portions and the individual coils, and the individual cut wire portions are insulated from one another at high frequencies by the individual coils. Voltages are impressed on the individual cut wire portions independently, so discharges can be generated simultaneously, in parallel.

Abstract: A wire electric discharge machining apparatus that performs an electric discharge machining by applying a pulse voltage between a wire electrode (1) and a workpiece (2), the wire electric discharge machining apparatus including, a machining speed detection unit (14) that detects relative machining speed of the workpiece (2) and the wire electrode (1); a machining energy calculation unit (13) that calculates machining energy of a discharge pulse; a board thickness calculation unit (12) that calculates a board thickness of the workpiece (4) based on the machining speed detected by the machining speed detection unit (14) and the machining energy calculated by the machining energy calculation unit (13); a stationary state determination unit (16) that determines whether the machining is in a stationary state from a machining state during the machining, after the machining condition is switched in accordance with a board thickness of the workpiece (4) calculated by the board thickness calculation unit (12); and a m

Abstract: Provided are a wire electric discharge machining method for poorly conductive materials, such as solar cell silicon, and a semiconductor wafer manufacturing method and a solar battery cell manufacturing method based on the wire electric discharge machining method. Electrical discharge machining of a high volume resistivity, hard and brittle materials, having a volume resistivity that is equal to or higher than 0.5 ?·cm and equal to or lower than 5 ?·cm is performed by applying a pulse voltage having a pulse width that is equal to or higher than 1 ?sec and equal to or lower than 4 ?sec and having a peak current at the time of machining a wire electrode that is equal to or higher than 10A and equal to or lower than 50A to a wire electrode and generating a discharge pulse between the wire electrode and a subject to be machined.

Abstract: A wire electric discharge machine includes a wire electrode; a machining power supply that supplies a machining current to between the wire electrode and a workpiece. The machine further includes a first power feed contact and a second power feed contact that respectively feed power to the wire electrode; a first machining-current loop in which a first machining current flows from the first power feed contact toward the workpiece; a second machining-current loop in which a second machining current flow from the second power feed contact toward the workpiece; an impedance switching circuit that is provided in at least any one of the first machining-current loop and the second machining-current loop; and a control unit that controls a flow ratio of the first machining current and the second machining current by changing an impedance of the impedance switching circuit.

Abstract: 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.

Abstract: An electric discharge machining apparatus includes: electrodes the total quantity of which is equal to N; an alternating-current power source; and capacitors the total quantity of which is equal to N. The alternating-current power source applies an alternating voltage commonly to the electrodes. One end of each of the capacitors is connected to a corresponding one of the electrodes, whereas the other ends of the capacitors are commonly connected to the alternating-current power source.

Abstract: Based on a discharging gap value and machining allowance value stored in a corner-control-information storing means 20, a speed-ratio calculating means 23 being a machining-volume calculating means calculates machining volumes of a straight line portion and a corner portion to calculate a volume ratio therebetween. A corner-portion-speed calculating means 24 calculates a machining feed speed at the corner portion based on a volume ratio calculated by the speed-ratio calculating means 23, and then outputs to a servo amplifier 8 on the basis of the length of a pre-corner section outputted by a pre-corner-section calculating means 21 and the length of a post-corner section outputted by a post-corner-section calculating means 22, instructions about machining feed speeds from entering the pre-corner section till getting out of the post-corner section.

Abstract: A wire machining method includes: a wire electrode set as cutting wires provided in parallel with a distance between the cutting wires of which a predetermined regional part faces a workpiece; a machining power source that generates a pulse-shaped machining voltage; and plural feeder units that are electrically connected to the plural cutting wires respectively of the wire electrode and supply the machining voltage between the cutting wires and the workpiece respectively. The feeder units are arranged such that a direction of a current passed to at least a part of the cutting wires becomes a direction different from a direction of a current passed to other cutting wires.

Abstract: 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.

Abstract: In a wire electrical discharge machining apparatus, an upper main-discharge power supply is connected between an upper conducting terminal and a workpiece using an upper main-feeder line capable of configuring outward and homeward paths, and a lower main-discharge power supply is connected between a lower conducting terminal and the workpiece using a lower main-feeder line capable of configuring outward and homeward paths. Moreover, a sub-discharge power supply is connected between the upper conducting terminal and the workpiece and between the lower conducting terminal and the workpiece using an upper and a lower sub-feeder lines that have higher impedances than the impedances of the upper and the lower main-feeder lines and can configure outward and homeward paths.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A wire electric discharge machine includes a wire electrode; a machining power supply that supplies a machining current to between the wire electrode and a workpiece; a first power feed contact and a second power feed contact that respectively feed power to the wire electrode; a first machining-current loop that lets a first machining current to flow from the first power feed contact toward the workpiece; a second machining-current loop that lets a second machining current to flow from the second power feed contact toward the workpiece; an impedance switching circuit that is provided in at least any one of the first machining-current loop and the second machining-current loop; and a control unit that controls a flow ratio of the first machining current and the second machining current by changing an impedance of the impedance switching circuit.

Abstract: Provided are a wire electric discharge machining method for poorly conductive materials, such as solar cell silicon, and a semiconductor wafer manufacturing method and a solar battery cell manufacturing method based on the wire electric discharge machining method. Electrical discharge machining of a high volume resistivity, hard and brittle materials, having a volume resistivity that is equal to or higher than 0.5 ?·cm and equal to or lower than 5 ?·cm is performed by applying a pulse voltage having a pulse width that is equal to or higher than 1 ?sec and equal to or lower than 4 ?sec and having a peak current at the time of machining a wire electrode that is equal to or higher than 10A and equal to or lower than 50A to a wire electrode and generating a discharge pulse between the wire electrode and a subject to be machined.

Abstract: In an electric-discharge machining apparatus for controlling a machining axis so that an average voltage Vg during a predetermined sampling time Ts agrees with a servo standard voltage SV, the apparatus includes: an electric power supplier 9 for supplying electric power between electrodes of a tool electrode 8 and a target W to be machined; an electric-discharge detector 13 for detecting the waveform of electric discharge generating between the electrodes based on the electric power supplied by the electric power supplier 9; an electric-discharge generation counter 14 for counting in response to the waveform an electric-discharge generation count Nd during the predetermined sampling time Ts; a calculator 12 for calculating an estimation average voltage Vgs between the electrodes based on the electric-discharge generation count Nd; and an electrode-position controller 10 for controlling the machining axis so that the estimation average voltage Vgs calculated by the calculator 12 agrees with the servo standard