Abstract: The liquid-quality adjusting apparatus of the present invention includes: a water purifying part that deionizes a machining liquid; an anticorrosive part that exchanges ions in the machining liquid with anticorrosive ions; a conductivity measuring part that measures a measured value of conductivity of the machining liquid; a storage part that stores in advance a first reference value and a second reference value which are an upper limit value and a lower limit value of conductivity applicable to machining, respectively, and a third reference value which is between the first reference value and the second reference value; and a control part that performs control on the basis of the reference values stored in the storage part and the measured value of the conductivity of the machining liquid measured by the conductivity measuring part.

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 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: The present invention includes a post-cooling temperature sensor that measures a temperature of the machining fluid immediately after being cooled by a cooling device as a post-cooling fluid temperature, and an intra-tank temperature sensor that measures a temperature of the machining fluid in a work tank as an intra-tank fluid temperature, for a cooling control device that controls a fluid temperature of the machining fluid in a wire electric discharge machining apparatus, and the cooling control device has a first temperature-feedback control unit that feeds back the post-cooling fluid temperature into a cooling instruction value as an instruction value for the cooling device, and a second temperature-feedback control unit adjusts the cooling instruction value by feeding back the intra-tank fluid temperature to cause the intra-tank fluid temperature to follow a target temperature.

Abstract: An object is to enable highly accurate machining by correcting machining conditions by referring to a programmed trajectory to obtain a desired machining shape. A wire electric discharge machining apparatus includes a machining-condition correcting unit that corrects machining conditions in each machining stage corresponding to a circular arc radius of a portion corresponding to a corner portion of a programmed trajectory, in the corner portion formed by changing a direction of relatively moving a wire electrode, when the wire electrode is moved on a wire center trajectory, which is offset from the programmed trajectory prestored in order to obtain a desired machining shape to perform finish machining in each machining stage with an offset amount being changed.

Abstract: A wire electric discharge machining apparatus includes a wire electrode, a guide roller that arranges wire electrodes in parallel by winding the wire electrode therearound, a plurality of slidable contact conductors that are in slidable contact with the wire electrodes arranged in parallel, respectively, and a power feeding jig that holds the slidable contact conductors individually and feeds power individually to the wire electrodes arranged in parallel via each of the slidable contact conductors, in which the power feeding jig includes a plurality of reference surfaces that determine a fixing interval between the slidable contact conductors.

Abstract: A workpiece retainer retains a workpiece at a time of a cutting process by a wire electric discharge machining device that cuts a workpiece by electric discharge from wire electrodes that are spaced from each other and are arranged in parallel. The workpiece retainer is formed with a fitting portion, into which the workpiece is fitted substantially without any gap, and has an external shape such that at a time of cutting the workpiece retainer together with the workpiece fitted in the fitting portion, a length along the wire electrodes of a portion where the workpiece retainer and the workpiece face the wire electrodes becomes substantially constant during the cutting process of the workpiece.

Abstract: 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.

Abstract: An electrical discharge machining apparatus includes a machining electrode that is one wire and includes a plurality of opposing sections with respect to a workpiece by being wound around a plurality of guide rollers, driving units that change a relative distance between the workpiece and the opposing sections, and a plurality of pulse generating units that apply electrical discharge machining pulses between the workpiece and the opposing sections, respectively, in which the pulse generating units are controlled such that application start times of electrical discharge machining pulses for adjacent opposing sections do not coincide with each other.

Abstract: 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.

Abstract: The liquid-quality adjusting apparatus of the present invention includes: a water purifying part that deionizes a machining liquid; an anticorrosive part that exchanges ions in the machining liquid with anticorrosive ions; a conductivity measuring part that measures a measured value of conductivity of the machining liquid; a storage part that stores in advance a first reference value and a second reference value which are an upper limit value and a lower limit value of conductivity applicable to machining, respectively, and a third reference value which is between the first reference value and the second reference value; and a control part that performs control on the basis of the reference values stored in the storage part and the measured value of the conductivity of the machining liquid measured by the conductivity measuring part.

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 positioning device includes a driver which moves a positioning object and a sensor which measures the distance to the positioning object in a non-contacting manner and outputs a detection signal if the positioning object is detected only in a length measuring area within a predetermined range from any detection position, shaft controller which stops the driver by detecting the detection signal from the sensor and automatically correcting for an overshoot amount between the stop position and any detection position, when the driver moves the positioning object and the sensor, and the positioning controller that stores the coordinate value after the automatic correction by the shaft controller and that performs the positioning based on the reference coordinate value.

Abstract: An object is to enable highly accurate machining by correcting machining conditions by referring to a programmed trajectory to obtain a desired machining shape. A wire electric discharge machining apparatus includes a machining-condition correcting unit that corrects machining conditions in each machining stage corresponding to a circular arc radius of a portion corresponding to a corner portion of a programmed trajectory, in the corner portion formed by changing a direction of relatively moving a wire electrode, when the wire electrode is moved on a wire center trajectory, which is offset from the programmed trajectory prestored in order to obtain a desired machining shape to perform finish machining in each machining stage with an offset amount being changed.

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: 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.

Abstract: 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.

Abstract: To provide an electric discharge device capable of performing an optimum process that achieves a high-quality process in a satisfactory quality of processing precision and the like. In an electric discharge device that processes a workpiece by electric discharge, a reserve electric-discharge pulse is applied by alternately switching between a positive polarity and a reverse polarity, and a current waveform shape of a main electric-discharge pulse is differentiated corresponding to a polarity of a reserve electric-discharge pulse, to a main electric-discharge pulse to be applied after detecting electric discharge following the reserve electric-discharge pulse. With this arrangement, a processing current shape can be optimized corresponding to an electric discharge characteristic, and thus a high-precision process can be performed.

Abstract: A positioning device includes moving means (2) for relatively moving a positioning object (21) and length measuring means (8) for measuring the distance to the positioning object (21) in non-contact manner and outputting a detection signal if the positioning object (21) is detected only in a length measuring area within a predetermined range from any detection position, shaft control means for stopping the moving means (2) by detecting the detection signal from the length measuring means (8) and automatically correcting for an overshoot amount between the stop position and any detection position, when the moving means (2) relatively moves the positioning object (21) and the length measuring means (8), and positioning control means (11) for storing the coordinate value after the automatic correction by the shaft control means and performing the positioning based on the reference coordinate value.

Abstract: An electric-discharge machining apparatus for machining a workpiece by an electric discharge generated between a machining electrode and the workpiece, includes a correcting unit that corrects a machining amount input for machining the workpiece, based on a usage history of the machining electrode; and a control unit that controls a machining processing on the workpiece based on the machining amount corrected.