Circuits Patents (Class 219/69.13)
  • Patent number: 9440300
    Abstract: An electric discharge machining apparatus of the present invention includes a power supply, an electrode gap configured so as to be formed by an electrode and a workpiece, and an earth floating-capacitance current-suppressing coil configured to be inserted between the power supply and the electrode gap. Accordingly, the impedance in the charging path from the power supply to an interelectrode capacitance (an interelectrode parallel capacitor and an interelectrode parallel floating capacitance) can be decreased, and the impedance in the charging path to an earth floating capacitance can be increased, thereby enabling the electric current from the earth floating capacitance during discharge machining to be suppressed.
    Type: Grant
    Filed: October 30, 2012
    Date of Patent: September 13, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Tomoaki Takada, Takashi Hashimoto, Ieyoung Kim, Takayuki Nakagawa, Yuto Sasaki, Yuji Nasu, Masato Terashima
  • Patent number: 9421626
    Abstract: An apparatus for electrical discharge machining modulation control includes an EDM module, an open-circuit voltage modulation module, a reference-voltage modulation and judgment module, a database, and a control unit. The control unit selects a reference voltage, and an open-circuit voltage corresponding to characteristics of a workpiece from the database, and generates and transmits a second control signal to the open-circuit voltage modulation module for modulating the open-circuit voltage, and a third control signal to the reference-voltage modulation and judgment module for modulating the reference voltage utilized to determine if the ignition happened. The open-circuit voltage modulation module receives a first control signal periodically transmitted from the control unit for providing the open-circuit voltage to the EDM module.
    Type: Grant
    Filed: July 5, 2013
    Date of Patent: August 23, 2016
    Assignee: INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE
    Inventors: Chao-Chuang Mai, Chin-Hui Chen, Chih-Ping Cheng, Der-Shuen Chen, Ming-Ji Chen
  • Patent number: 9421393
    Abstract: A system and methods for controlling pulse parameters during transcranial magnetic stimulation are provided. Multiple coils are placed on external body parts, and are controlled using an external control unit coupled to a stimulator having fast switches. The timing of the switches, as well as other parameters within the stimulator, determine the pulse parameters, such as pulse shape. The variety of pulse shapes obtainable using such a system and methods provides controlled physiologic effects within an internal body organ.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: August 23, 2016
    Assignee: Yeda Research & Development Co., Ltd. at the Weizmann Institute of Science
    Inventors: Yiftach Roth, Vadim Chudnovsky, Noach Safra, David Hazani, Abraham Zangen
  • Patent number: 9376900
    Abstract: A hydrocarbon resource recovery apparatus for a subterranean formation having a wellbore extending therein includes a radio frequency (RF) power source, a dielectric fluid source, and an RF antenna within the wellbore. An RF transmission line extends within the wellbore between the RF power source and the RF antenna and is coupled to the dielectric fluid source to be cooled and/or pressure balanced by a flow of dielectric fluid therefrom. A hydrocarbon resource recovery pump is within the wellbore and is also coupled to the dielectric fluid source to be powered by the flow of dielectric fluid therefrom.
    Type: Grant
    Filed: January 13, 2014
    Date of Patent: June 28, 2016
    Assignee: HARRIS CORPORATION
    Inventors: Ryan Matthew Whitney, Keith Nugent, Raymond C. Hewit, Brian N. Wright
  • Patent number: 9314859
    Abstract: A contact detection apparatus for a wire electrical discharge machine includes a voltage application unit adapted to apply a detection voltage to detect contact between a wire electrode and a workpiece; a contact determination unit adapted to determine contact or non-contact between the wire electrode and the workpiece based on changes in the detection voltage applied by the voltage application unit; and a voltage value changing unit adapted to change a voltage value of the detection voltage applied by the voltage application unit.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: April 19, 2016
    Assignee: FANUC CORPORATION
    Inventors: Tomoaki Matsunaga, Yushi Takayama, Akiyoshi Kawahara
  • Patent number: 9318969
    Abstract: A frequency converter has an AC-DC converter and an inverter interconnected via a DC link having a first and a second circuit branch interconnected by a DC link capacitor and a commutation capacitor. To protect the AC-DC converter from damage caused by an overcurrent, the first circuit branch includes a choke in which a capacitor-side terminal is connected to a terminal of the DC link capacitor and a switch-side terminal is connected via a semiconductor switch to a DC link terminal of the AC-DC converter and also via a freewheeling diode to the second circuit branch. The semiconductor switch is configured to control a magnitude of an electric current flowing from the AC-DC converter into the DC link capacitor in accordance with a control signal.
    Type: Grant
    Filed: June 28, 2013
    Date of Patent: April 19, 2016
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Reinhold Dillig, Hubert Schierling, Thomas Schwinn
  • Patent number: 9248519
    Abstract: A gear machining condition setting device receives a feeding amount determining parameter and a cutting speed determining parameter. A storage unit stores a cutting-in amount calculation formula representing a relation between a cutting-in amount and a characteristic value determined based on a feeding amount and the feeding amount determining parameter. The feeding amount of the hob, corresponding to the cutting-in amount, is computed using the cutting-in amount calculation formula. Further, the storage unit stores data of a constant temperature curve representing a relation between the cutting-in amount and the cutting speed where a cutting edge of the hob is set at a predetermined temperature. Using the data, the cutting speed is computed based on the cutting-in amount and the cutting speed determining parameter with reference to the constant temperature curve.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 2, 2016
    Assignee: KOMATSU LTD.
    Inventors: Junshi Kugo, Ryou Yamaguchi, Eiji Nabata
  • Patent number: 9212072
    Abstract: An apparatus delivering multi-vibrational, frequency-based, electromagnetic fields, which are independent but may work simultaneously. The apparatus may be used in many applications, especially in industrial applications such as cooling towers and related pipes and plumbing. The apparatus ELIMINATES calcium based hard water deposits and PROHIBITS bacteria build-up in cooling towers. The apparatus will help reduce soap usage in industrial laundry, reduce salt usage in water softeners, reduce chemical use in pools, inhibit algae growth and increase water clarity. The apparatus will restructure calcium carbonate and other mineral deposits to prevent mineral buildup. The apparatus may be formed from a plurality of wire-wrapped rods staggered around a pipe and connected to a power supply. The plurality of rods may be encased in flexible coating, wrapped in appropriate fabric, or encased in metal outer covering. As a result, waste water is reduced, water costs is kept low, and water is conserved.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: December 15, 2015
    Inventor: Lynell Braught
  • Patent number: 9130554
    Abstract: 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.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: September 8, 2015
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Hashimoto, Junichi Shibata, Yoshikazu Ukai
  • Patent number: 9114468
    Abstract: The present invention includes a series circuit that includes a DC power supply and a switching element for supplying a DC or AC current pulse to a machining gap between a machining electrode and a workpiece; and a control unit that controls the switching element, wherein when generating a current pulse having a triangular shape by an inductance present on the series circuit, the control unit controls on-time and off-time of the switching element such that a peak value of an arbitrary current pulse in a pulse train including a plurality of current pulses changes.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: August 25, 2015
    Assignee: Mitsubishi Electric Corporation
    Inventors: Masahiro Okane, Satoshi Suzuki, Kiyohito Oda
  • Patent number: 9066373
    Abstract: A system and method of controlling an induction cooking appliance based on a feedback signal. A feedback signal sampling time interval may be triggered when a power control signal has a magnitude of zero. The feedback signal sample may be used to calculate a status factor and the appliance may be controlled based on the calculated status factor.
    Type: Grant
    Filed: February 8, 2012
    Date of Patent: June 23, 2015
    Assignee: General Electric Company
    Inventors: John Michael Kulp, Jr., Gregory Francis Gawron, Sr., Daniel Vincent Brosnan, Mingwei Shan
  • Publication number: 20150114936
    Abstract: An electric discharge machine has a hand operation panel, which is provided with a manual pulse generator with a rotating part. The manual pulse generator generates a pulse signal corresponding to a rotation angle position of the rotating part. Further, the manual pulse generator outputs a move command for changing (i.e., increasing or decreasing) a relative distance between a tool electrode and a workpiece and commands for changing set values of machining conditions, based on the pulse signal from the manual pulse generator.
    Type: Application
    Filed: October 28, 2014
    Publication date: April 30, 2015
    Inventor: Tomoaki MATSUNAGA
  • Publication number: 20150069022
    Abstract: When a Z axis is moved while interrupting or continuing taper machining, a wire electric discharge machining control apparatus controls position of a UV axis by re-creating a taper deviation vector, based on a distance between upper and lower guides, such that a wire tilt angle does not change.
    Type: Application
    Filed: August 28, 2014
    Publication date: March 12, 2015
    Inventor: Yuji TUBOGUCHI
  • Patent number: 8975554
    Abstract: A voltage is applied to a machining gap between a wire electrode and a workpiece for a period of one microsecond or less with a quiescent time longer than the duration of voltage application between each two adjacent cycles of voltage application provided, and the number of duty cycles and a machining-gap voltage are detected. An open-circuit state in which electric discharge does not occur after the voltage is applied is identified by the detected machining-gap voltage, and the number of open-circuits is counted. An average machining-gap voltage is obtained based on the numbers of duty cycles and open-circuits and the supply voltage or an average voltage for each duty cycle.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: March 10, 2015
    Assignee: Fanuc Corporation
    Inventors: Akiyoshi Kawahara, Masao Murai, Tomoyuki Furuta
  • Publication number: 20150060412
    Abstract: The invention relates to a pulse generator module (50) for electric discharge machines which comprises a generator enclosure (51) containing printed circuit boards (PCBs), wherein at least one of the PCBs is a generator board (52). The PCBs (52) are all arranged in one plane.
    Type: Application
    Filed: August 28, 2014
    Publication date: March 5, 2015
    Inventor: Rino d'Amario
  • Patent number: 8963041
    Abstract: An electric discharge machine die sinking device includes a tank for holding a fluid, and at least one electrode in the tank having a shape for imparting to a first portion of a workpiece. A workpiece holder positions the workpiece at least partially immersed in the fluid and alternately moves the workpiece between an inoperable position and a first operable position of the first electrode at which electric discharge machining occurs on the first portion. A pulse generator creates an electric discharge between the first portion and the first electrode to remove material from the first portion in response to the workpiece being in the first operable position. Movement of the workpiece from the electrode flushes particle containing fluid away from the workpiece and the electrode. A segmented electrode includes a separate pulse generator for each segment may also be employed.
    Type: Grant
    Filed: March 21, 2012
    Date of Patent: February 24, 2015
    Assignee: General Electric Company
    Inventor: Yuefeng Luo
  • Publication number: 20150001182
    Abstract: A wire electrical discharge machining apparatus includes: multiple main rollers around which a wire winds in parallel; multiple workpiece feeding units for feeding the workpiece toward the wire; a machining power supply unit for supplying a machining voltage to the workpiece; and a power supply terminal for supplying the machining voltage to the wire. The multiple workpiece feeding units are respectively arranged at a first position for feeding the workpiece toward a wire portion having a wire plane of the wire and a second position for feeding another workpiece toward another wire portion having another wire plane of the wire. The power supply terminal is arranged at a third position between the first position and the second position. The machining voltage supplied from the single machining power supply unit is supplied to the workpieces to be electrically discharge machined by the multiple workpiece feeding units.
    Type: Application
    Filed: June 26, 2014
    Publication date: January 1, 2015
    Inventor: Haruya Kurihara
  • Patent number: 8907243
    Abstract: The tension measuring unit that measures a physical amount corresponding to tension of a wire in a wire transport system, the fluctuation recording unit that records the physical amount measured by the tension measuring unit, the fluctuation analysis unit that obtains an average value, variation, and frequency analysis data of the recorded physical amount as an analysis result of the physical amount, the maintenance necessity determining unit that compares the analysis result with a reference value and determines whether maintenance is needed based on a comparison result and the display unit that displays a determination result are included, and it is made possible to accurately determine the time for maintenance for various components used in the wire transport system without using a measuring instrument.
    Type: Grant
    Filed: April 7, 2009
    Date of Patent: December 9, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kohtaroh Watanabe, Kazushi Nakamura
  • Patent number: 8901448
    Abstract: An electric discharge machine includes a machining power supply for applying a voltage to a machining gap between a machining electrode and its opposite workpiece and detecting a contact between the machining electrode and the workpiece. The machining power supply includes a first power supply circuit whose output voltage is equal to or less than an arc voltage, a second power supply circuit for supplying a pulse current to the machining gap, and a control unit. When the first power supply circuit detects a contact between the machining electrode and the workpiece, the control unit operates to supply a pulse current from the second power supply circuit to the machining gap while the machining electrode and the workpiece are in contact with each other.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: December 2, 2014
    Assignee: Fanuc Corporation
    Inventors: Masao Murai, Yasuo Arakawa, Tomoyuki Furuta
  • Publication number: 20140339199
    Abstract: An electric discharge processing machine applies a voltage to a processing subject and a corrosion preventing electrode so as to prevent the corrosion of the processing subject. A reference current value which is proportional to the surface area of the processing subject is set so that a current density is maintained constantly, and a voltage of a corrosion preventing power supply is controlled so that a corrosion preventing current falls within a predetermined range.
    Type: Application
    Filed: May 2, 2014
    Publication date: November 20, 2014
    Applicant: FANUC Corporation
    Inventor: Tomoaki MATSUNAGA
  • Publication number: 20140319102
    Abstract: The present invention includes a series circuit that includes a DC power supply and a switching element for supplying a DC or AC current pulse to a machining gap between a machining electrode and a workpiece; and a control unit that controls the switching element, wherein when generating a current pulse having a triangular shape by an inductance present on the series circuit, the control unit controls on-time and off-time of the switching element such that a peak value of an arbitrary current pulse in a pulse train including a plurality of current pulses changes.
    Type: Application
    Filed: November 30, 2011
    Publication date: October 30, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masahiro Okane, Satoshi Suzuki, Kiyohito Oda
  • Patent number: 8835793
    Abstract: On a wire guide supporting face of a wire guide supporting part which supports a wire guide of a wire electric discharge machine, two wall faces which are orthogonal to the wire guide supporting face are formed to be arranged in a V shape. On the other hand, two planar parts which are abutted on the two orthogonal wall faces, which are arranged in the V shape, of the wire guide supporting part are formed on the wire guide. Then, the wire guide is fixed on the wire guide supporting part with a screw in a state in which the two orthogonal wall faces of the wire guide supporting part and the two planar parts of the wire guide are respectively abutted on each other.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: September 16, 2014
    Assignee: Fanuc Corporation
    Inventor: Hikaru Yamane
  • Patent number: 8835792
    Abstract: A device and method for the removal of a metal-sheath layer from a metal-sheathed structure using capacitive discharge in conjunction with step-up and step-down transformers to create a low voltage, high current pulse to remove a selected portion of the metal-sheath layer from the metal-sheathed structure.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: September 16, 2014
    Assignee: The Cleveland Electric Laboratories Company
    Inventors: Witold Pietrzak, Donald Robert Way
  • Publication number: 20140255716
    Abstract: Multi-metal particles, apparatuses and method of making same are provided. Specifically, the multi-metal particles are of nanometer dimensions and are prepared by spatially arranged electrodes configured to generate and maintain a plasma cloud.
    Type: Application
    Filed: March 8, 2013
    Publication date: September 11, 2014
    Inventors: Donald G. Faulkner, Darren R. Burgess, David John Fennimore
  • Patent number: 8829383
    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.
    Type: Grant
    Filed: July 3, 2008
    Date of Patent: September 9, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yasuo Onodera, Tamayo Ohata, Tatsushi Sato, Hidetaka Miyake, Takashi Yuzawa, Atsushi Taneda
  • Publication number: 20140190941
    Abstract: In a power supply device for electric discharge machining, the polarity of the voltage to be applied is determined on the basis of a result of determination whether the machining gap is in open state or not, an average value of voltages applied across the machining gap voltage during machining, and the number of successive open states with the same polarity. This eliminates the need to significantly vary the voltages to be applied from positive to negative and from negative to positive, thereby reducing the output energy required by the machining power supply.
    Type: Application
    Filed: December 23, 2013
    Publication date: July 10, 2014
    Applicant: FANUC CORPORATION
    Inventors: Masao MURAI, Tomoyuki FURUTA
  • Publication number: 20140144885
    Abstract: In order to detect a wire breakage as soon as possible, the wire electrical discharge machining apparatus includes a speed fluctuation compensator that generates a speed fluctuation suppression command that is a speed compensation value that suppresses fluctuation of the rotational speed of the tension motor on the basis of the rotational speed of the tension motor and a breakage detecting device that detects a breakage of the wire electrode on the basis of a comparison of a preset breakage detection threshold and a speed fluctuation suppression command output from the speed fluctuation compensator.
    Type: Application
    Filed: July 6, 2011
    Publication date: May 29, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yasuo Onodera, Takayuki Nakagawa
  • Patent number: 8735763
    Abstract: A switching element operates to be turned on or off at a frequency in the order of megahertz. A reactor supplies a resonance current generated by resonance of the reactor with a floating capacitance between electrodes to between the electrodes. The resonance current does not flow in a direct-current power supply. By turning a capacitor and a floating inductance into a serial resonant state, the reactor ideally supplies the resonance current to between the electrodes without influence of the floating inductance. A high-frequency voltage asymmetric in positive and negative polarities is applied to between the electrodes and a current pulse can be made into a short pulse. Therefore, finish machining with high surface roughness can be performed.
    Type: Grant
    Filed: March 9, 2009
    Date of Patent: May 27, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Hashimoto, Taichiro Tamida, Takayoshi Nagai
  • Patent number: 8735762
    Abstract: In order to detect a machining state of a wire electric discharge machine, the state of a machining gap is classified into three categories; an open-circuit state in which electric discharge does not occur after a first predetermined level is reached or surpassed by a machining-gap voltage, an electric discharge state in which electric discharge occurs after a second predetermined level is reached or surpassed by the machining-gap voltage, whereby the machining-gap voltage becomes lower than the second predetermined level, and a short-circuit state wherein a third predetermined level is not reached or surpassed by the machining-gap voltage. An average voltage in the machining gap is determined based on voltages in these states and the number of cycles of voltage application to the machining gap, number of open-circuits, number of discharges, and number of short-circuits per unit time.
    Type: Grant
    Filed: November 19, 2012
    Date of Patent: May 27, 2014
    Assignee: Fanuc Corporation
    Inventors: Masao Murai, Tomoyuki Furuta
  • Patent number: 8729420
    Abstract: Machining state information is acquired for each predetermined period by performing test machining by an electric discharge machine, and the acquired machining state information is compared with reference machining state information, whereby whether a machining state is satisfactory or not is determined. If the machining state is determined to be unsatisfactory, set items of a machining condition are adjusted. Thereafter, test machining is actually performed again, and the machining condition is adjusted by changing the set items if the machining state is determined again to be unsatisfactory. Thus, the acquisition of the machining state information, determination of the machining state, and adjustment of the machining condition are repeated so that satisfactory machining is finally determined.
    Type: Grant
    Filed: July 14, 2012
    Date of Patent: May 20, 2014
    Assignee: Fanuc Corporation
    Inventors: Takehiro Kudou, Kaoru Hiraga
  • Publication number: 20140131318
    Abstract: Systems and methods for controlled and precise EDM manufacturing of a component are disclosed.
    Type: Application
    Filed: November 14, 2012
    Publication date: May 15, 2014
    Applicant: General Electric Company
    Inventors: Yuefeng Luo, William Edward Adis, Michael Lewis Jones
  • Publication number: 20140116990
    Abstract: An electric discharge machining apparatus of the present invention includes a power supply, an electrode gap configured so as to be formed by an electrode and a workpiece, and an earth floating-capacitance current-suppressing coil configured to be inserted between the power supply and the electrode gap. Accordingly, the impedance in the charging path from the power supply to an interelectrode capacitance (an interelectrode parallel capacitor and an interelectrode parallel floating capacitance) can be decreased, and the impedance in the charging path to an earth floating capacitance can be increased, thereby enabling the electric current from the earth floating capacitance during discharge machining to be suppressed.
    Type: Application
    Filed: October 30, 2012
    Publication date: May 1, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Tomoaki Takada, Takashi Hashimoto, Ieyoung Kim, Takayuki Nakagawa, Yuto Sasaki, Yuji Nasu, Masato Terashima
  • Patent number: 8710392
    Abstract: An apparatus and method for machining apertures into a conductive workpiece is disclosed. The apparatus has a tank capable of holding a dielectric fluid, and a fixture for holding the workpiece in the tank. An electric discharge machine with an electrode, a power supply connected to the electrode that produces machining pulses for electric discharge machining through the workpiece, and a controller for regulating the power supply and electrode position is also part of the apparatus. Finally, the apparatus has a pressure transducer connected to the fixture, and a process controller in communication with the electric discharge machine controller and pressure transducer.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: April 29, 2014
    Assignee: United Technologies Corporation
    Inventors: Sergey Mironets, James M. Koonankeil, Edward F. Pietraszkiewicz, Thomas R. Davis
  • Publication number: 20140083980
    Abstract: An apparatus for electrical discharge machining modulation control includes an EDM module, an open-circuit voltage modulation module, a reference-voltage modulation and judgment module, a database, and a control unit. The control unit selects a reference voltage, and an open-circuit voltage corresponding to characteristics of a workpiece from the database, and generates and transmits a second control signal to the open-circuit voltage modulation module for modulating the open-circuit voltage, and a third control signal to the reference-voltage modulation and judgment module for modulating the reference voltage utilised to determine if the ignition happened. The open-circuit voltage modulation module receives a first control signal periodically transmitted from the control unit for providing the open-circuit voltage to the EDM module.
    Type: Application
    Filed: July 5, 2013
    Publication date: March 27, 2014
    Inventors: CHAO-CHUANG MAI, CHIN-HUI CHEN, CHIH-PING CHENG, DER-SHUEN CHEN, MING-JI CHEN
  • Patent number: 8648275
    Abstract: A power supply device comprises a DC power supply (12), a current sensor (14) for detecting gap current (Igap) flowing through the machining gap, a first switching element (16) connected in series between the DC power supply and the tool electrode (2), a first reverse current prevention diode (22) connected in parallel with the DC power supply and connected in series with the first switching element (16), a second switching element (18) connected in series between the DC power supply and the workpiece (3), a second reverse current prevention diode (24) connected in parallel with the DC power supply and connected in series with the second switching element (18), and a pulse controller (20) for controlling the first and second switching elements in response to gap current (Igap). From a first time (t1) when electric discharge is generated across the machining gap, until a second time (t2) when the gap current reaches the peak current during the ON time, both of the first and second switching elements are on.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: February 11, 2014
    Assignee: Sodick Co., Ltd.
    Inventors: Kuniharu Yamada, Tomoyuki Yanagisawa
  • Publication number: 20140027409
    Abstract: An electric-discharge machining device including an electric-discharge-state determination unit that determines whether an electric discharging state between a machining electrode and a workpiece is either a state of normal electric discharge or of abnormal electric discharge, and a machining-condition switching unit that changes at least one machining condition, further includes a storage unit that stores therein an electric-discharge-state determination indicator, a standard-deviation calculation unit, and a boundary calculation unit that calculates a boundary to be applied to a determination in the electric-discharge-state determination unit based on the electric-discharge-state determination indicator, wherein the machining-condition switching unit changes the machining condition according to a comparison result between the standard deviation calculated by the standard-deviation calculation unit and a standard deviation reference set as a reference of the standard deviation.
    Type: Application
    Filed: July 25, 2012
    Publication date: January 30, 2014
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yasuo Onodera, Hiroki Hikosaka, Kazunari Morita, Hidetaka Katougi
  • Publication number: 20140014624
    Abstract: The wire electric discharge machine comprises a machining power source with variable output voltage, a first power supply path through which a discharge pulse current is supplied from the power source by applying a voltage at machining gap to cause electric discharge, and a second power supply path through which a wire electrode cutting current is supplied from the power source to the wire electrode, and also comprises a switching device to switch the first and second power supply paths. Discharge pulse current is supplied through the first power supply path when machining the workpiece, whereas wire cutting current is supplied when cutting the wire electrode.
    Type: Application
    Filed: April 30, 2013
    Publication date: January 16, 2014
    Applicant: FANUC CORPORATION
    Inventors: Masayuki YOSHIDA, Akiyoshi KAWAHARA
  • Patent number: 8618433
    Abstract: A machine tool for separative machining of preferably plate-like workpieces, for example, metal sheets, has a workpiece support and a discharge device on the workpiece support. The discharge device discharges workpiece parts produced as products of the separative machining. The discharge device includes two opening sections are adjustable relative to one another in the horizontal Y direction to form a through-opening for discharge of workpiece parts. The opening sections are adjustable into different positions relative to one another in the horizontal Y direction, to form through-openings of different widths for discharge of workpiece parts.
    Type: Grant
    Filed: June 30, 2008
    Date of Patent: December 31, 2013
    Assignee: TRUMPF Werkzeugmaschinen GmbH + Co. KG
    Inventor: Joerg Heusel
  • Patent number: 8586891
    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.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: November 19, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Hashimoto, Yasuo Onodera, Tatsushi Sato, Koichiro Hattori, Hisashi Yamada
  • Publication number: 20130299459
    Abstract: An automatic wire connecting device includes a heating electrode that heats an electrode wire by applying a current to the electrode wire, a tension applying unit that applies a tension to the electrode wire to which the current is applied by the heating electrode, a tension control unit that controls the tension applied by the tension applying unit, and a power supply control unit that applies a heating current smaller than a preset annealing current to the electrode wire until a first set time elapses since the current starts to be applied and increases the current applied to the electrode wire to reach the annealing current during a second set time after the first set time elapses since the current starts to be applied.
    Type: Application
    Filed: January 20, 2012
    Publication date: November 14, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Zhengyong Liu, Rintaro Nagaoka
  • Publication number: 20130292360
    Abstract: The present invention is equipped with a series circuit that includes a DC power supply, switching elements and a diode for supplying DC or AC current pulses to a machining gap between a machining electrode and a workpiece, diodes that regulate a direction of the current flow to one direction, and a control unit that controls the switching elements. When the control unit generates a current pulse having a triangular waveform by an inductance that is present in the series circuit, the control unit controls the switching elements in order that a current-pulse time ratio that is a ratio between the non-current time and the current continuation time in the current pulse is equal to or lower than ?.
    Type: Application
    Filed: April 12, 2011
    Publication date: November 7, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masahiro Okane, Satoshi Suzuki, Kiyohito Oda
  • Patent number: 8525063
    Abstract: A wire electric discharge machining apparatus for machining a workpiece (7) by supplying current pulses to a work gap formed between a wire electrode (8) and the workpiece comprises a person detection sensor (10) for generating a person detection signal (EX) when the existence of a person is detected, and an NC device (20) that is configured to receive the person detection signal. When the NC device receives the person detection signal, it selects first machining conditions which improve machining speed. When the NC device does not receive the person detection signal, it selects second machining conditions which reduce the risk of wire breakage.
    Type: Grant
    Filed: July 1, 2010
    Date of Patent: September 3, 2013
    Assignee: Sodick Co., Ltd.
    Inventor: Kiyoyuki Yamazaki
  • Patent number: 8525064
    Abstract: An electric discharge machine to process a work piece includes a plurality of electrodes, and a plurality of discharge power supply units. The plurality of electrodes generate a plurality of discharges with the work piece, respectively. The plurality of discharge power supply units apply voltages for the plurality of electrodes, respectively and independently.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: September 3, 2013
    Assignee: Denso Corporation
    Inventors: Akira Itoh, Yasuji Inobe, Hiroshi Adachi, Takeshi Oochi, Kazuhisa Ikuta, Michio Kameyama
  • Patent number: 8519295
    Abstract: A controller of an electrical discharge machine comprises: a control unit that controls a machining condition set by the electrical discharge machine; an acquisition unit that acquires a parameter indicating an electrical discharge state between poles in a state where the machining condition is controlled by the control unit so that a normal electrical discharge occurs between the poles; an arithmetic unit that obtains a probability density distribution of the acquired parameter; a decision unit that decides a threshold that specifies a boundary between a normal electrical discharge and an abnormal electrical discharge between the poles based on the obtained probability density distribution; and a discrimination unit that discriminates whether the electrical discharge state between the poles is normal or abnormal by using the decided threshold, and wherein the control unit controls the machining condition based on a discrimination result of the discrimination unit.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: August 27, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kazunari Morita, Hiroki Hikosaka, Yasuo Onodera, Hidetaka Katougi
  • Publication number: 20130206732
    Abstract: An electric discharge machining unit that performs electric discharge machining by clamping a target object with a clamper of a clamping device, the electric discharge machining unit including a timer that measures a lapse of a time, which has been set by a user as a preparation time for supporting the target object after an operation of a clamping/unclamping button for clamping or unclamping is detected, and a clamper control unit that causes the clamping device to perform an operation corresponding to the detected operation at a time-out of the timer.
    Type: Application
    Filed: February 15, 2012
    Publication date: August 15, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Masaaki Nishio, Hidetaka Katougi
  • Publication number: 20130168362
    Abstract: A method of controlling an electric discharge machining apparatus having at least a tool electrode and a workpiece comprising positioning the tool electrode relative to the workpiece; generating at least one first type discharge impulse and at least one second type discharge impulse, wherein the at least one first type discharge impulse has a longer impulse duration than the impulse duration of the at least one second type discharge impulse, wherein the first type discharge impulse causes formation of a protective film against wear on the tool electrode and the second type discharge impulse causes erosion at least on the tool electrode; and applying the first and second type discharge impulses to a gap between the tool electrode and workpiece for material removal from the workpiece, wherein a ratio between the first and second type discharge impulses applied to the tool electrode causes predefined wear of the tool electrode.
    Type: Application
    Filed: December 26, 2012
    Publication date: July 4, 2013
    Applicant: AGIE CHARMILLES SA
    Inventor: Agie Charmilles SA
  • Patent number: 8476548
    Abstract: A method of cutting out a part from a workpiece with making partially welded spots in wire electrical discharge machining to keep the part against falling apart away from the workpiece. There is no need to cut anew the welded spot left as in the conventional process. The cut-out parts are cut off at a time after breakage of the welded spots caused by an external impact. The electric processing condition applied across an inter-electrode space between the wire electrode and the workpiece is changed from a cutting phase to a welding phase in which the wire electrode is fused partially at some spots along a cutting path of a predetermined contour on the workpiece to weld together the cut-out part and the workpiece at the fused spot on the wire electrode.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: July 2, 2013
    Assignee: Seibu Electric & Machinery Co. Ltd.
    Inventor: Takashi Mitsuyasu
  • Publication number: 20130140276
    Abstract: A controller of an electrical discharge machine comprises: a control unit that controls a machining condition set by the electrical discharge machine; an acquisition unit that acquires a parameter indicating an electrical discharge state between poles in a state where the machining condition is controlled by the control unit so that a normal electrical discharge occurs between the poles; an arithmetic unit that obtains a probability density distribution of the acquired parameter; a decision unit that decides a threshold that specifies a boundary between a normal electrical discharge and an abnormal electrical discharge between the poles based on the obtained probability density distribution; and a discrimination unit that discriminates whether the electrical discharge state between the poles is normal or abnormal by using the decided threshold, and wherein the control unit controls the machining condition based on a discrimination result of the discrimination unit.
    Type: Application
    Filed: December 2, 2011
    Publication date: June 6, 2013
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Kazunari Morita, Hiroki Hikosaka, Yasuo Onodera, Hidetaka Katougi
  • Patent number: 8455782
    Abstract: A portable EDM device and system thereof for producing calibration reflectors on a pipe includes a base mountable on the pipe, a motor mounted on the base, a cutting tool operably connected to the motor, an electrode operably connected to the cutting tool, a power source mounted on the base and operably connected to the electrode and operably connectable to the pipe, and a source of dielectric fluid mounted on the base. The power source is configured to electrically discharge a voltage from the electrode to the pipe to remove material from the pipe. The source of dielectric fluid is in fluid communication with the pipe to remove the material removed from the pipe.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: June 4, 2013
    Assignee: ALSTOM Technology Ltd
    Inventor: Stewart Joseph Akrin
  • Patent number: 8432116
    Abstract: In a torque motor driving device for wire cut electrical discharge machines, a voltage waveform rectified by a full-wave rectifying circuit, not using a high-capacitance electrolytic capacitor, is applied as an AC voltage to a single-phase torque motor by a bridge circuit including semiconductor switches. A PWM signal whose duty is adjusted so that the current flowing through the torque motor matches an instructed value is generated and the generated PWM signal is used for the operation of the bridge circuit.
    Type: Grant
    Filed: March 2, 2011
    Date of Patent: April 30, 2013
    Assignee: Fanuc Corporation
    Inventors: Tomoyuki Furuta, Akiyoshi Kawahara, Masao Murai