Patents by Inventor Akiyoshi Kawahara
Akiyoshi Kawahara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20230390843Abstract: This wire elective discharge machine includes: a relative movement control unit that performs an end surface detection operation a predetermined number of times; a storage control unit that stores, in a storage unit, a relative location of a wire electrode to a workpiece table when it is determined that a wire electrode is in contact with a workpiece in each end surface detection operation; and a data extraction unit that extracts, as effective data, a plurality of relative locations located in the order of a predetermined range in a middle when the plurality of relative locations are arranged in ascending order; and an end surface location determination unit that determines the location of an end surface of the workpiece on the basis of the effective data.Type: ApplicationFiled: October 18, 2021Publication date: December 7, 2023Inventors: Fuchen CHU, Akiyoshi KAWAHARA
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Patent number: 10751820Abstract: A wire electrical discharge machine is configured to perform removal machining of a workpiece by applying a voltage to a machining gap between a wire electrode and the workpiece through a feeder to generate electrical discharge and is provided with a feeder deterioration detection unit configured to detect deterioration of the feeder. The feeder deterioration detection unit includes a detection unit configured to detect a machining current value during the machining and a detection unit configured to detect the number of electrical discharges during the machining.Type: GrantFiled: December 30, 2016Date of Patent: August 25, 2020Assignee: FANUC CORPORATIONInventors: Tomoaki Matsunaga, Akiyoshi Kawahara
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Patent number: 10639735Abstract: A wire electrical discharge machine includes: an electrode unit for supplying a machining current to an electrode gap; a switch for changing impedance between a machining power source and the electrode unit; and a controller for, at the time of a core retaining process, controlling the switch to set the impedance to be higher than the impedance in a cutting process and thereby suppressing the machining current flowing through the electrode gap.Type: GrantFiled: January 25, 2018Date of Patent: May 5, 2020Assignee: FANUC CORPORATIONInventors: Tomoyuki Furuta, Yasuo Nakashima, Akiyoshi Kawahara
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Patent number: 10512980Abstract: A wire electrical discharge machining system includes: an electrode motion control unit for moving a wire electrode while keeping the wire electrode parallel to Z1-axis and bring the wire electrode into contact with a reference piece, and moving the wire electrode while keeping the wire electrode inclined with respect to the Z1-axis and bring the wire electrode into contact with the reference piece; an electrode position acquiring unit for acquiring a position of the wire electrode in an X1Y1Z1 orthogonal coordinate system when the wire electrode touches the reference piece; a piece position acquiring unit for acquiring a piece position of the reference piece in an X2Y2Z2 orthogonal coordinate system when the wire electrode touches the reference piece; and a relative positional relationship calculator for calculating a coordinate system relative positional relationship, based on the acquired positions.Type: GrantFiled: June 18, 2018Date of Patent: December 24, 2019Assignee: FANUC CORPORATIONInventors: Masashi Masuda, Akiyoshi Kawahara
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Patent number: 10376975Abstract: A wire electric discharge machine with tension monitoring function comprising a tension generation unit configured to generate tension in the wire electrode, a first tension measurement unit set on the wire electrode and configured to measure tension, and a tension control unit configured to feedback tension value measured by the first tension measurement unit and output tension command value to the tension generation unit such that the tension value is equal to a target value, wherein a warning signal is configured to be generated when the tension command value output by the tension control unit is not within a set range corresponding to the target value of the tension.Type: GrantFiled: December 27, 2015Date of Patent: August 13, 2019Assignee: FANUC CORPORATIONInventors: Masashi Masuda, Akiyoshi Kawahara, Yasuo Nakashima
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Patent number: 10315263Abstract: In a wire electric discharge machine of the present invention, a control variable detection apparatus is an inter-pole voltage detection apparatus and detects an average inter-pole voltage as a control variable correlating with an inter-pole distance. The wire electric discharge machine comprises a machining feed speed calculation apparatus determining a machining feed speed on the basis of a deviation between target voltage set by a target value setting apparatus 7 and the average inter-pole voltage so as to eliminate the deviation. The wire electric discharge machine further comprises a feed speed distribution apparatus and a relative movement apparatus. The inter-pole distance can be kept constant by the relative movement of a wire electrode and a workpiece made on the basis of a command of thus determined machining feed speed.Type: GrantFiled: August 23, 2016Date of Patent: June 11, 2019Assignee: FANUC CORPORATIONInventors: Akiyoshi Kawahara, Yasuo Nakashima
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Patent number: 10265790Abstract: In order to prevent a reduction in the rate of operation and malfunction due to dirt in a machining tank, a wire electric discharge machine configured to perform electric discharge machining in the machining tank is provided with a camera for capturing an image of the inside of the machining tank and determining unit for detecting dirt in the machining tank based on the image captured by the camera. The dirt in the machining tank is detected by the determining unit.Type: GrantFiled: March 2, 2016Date of Patent: April 23, 2019Assignee: FANUC CORPORATIONInventors: Tomoaki Matsunaga, Akiyoshi Kawahara, Yasuo Nakashima
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Patent number: 10220458Abstract: A machining power supply device for an electric discharge machine performs control to turn on a first semiconductor switching element, which is arranged in series between a DC power supply and a capacitor connected in parallel with a machining gap between an electrode and a workpiece, to charge the capacitor, and turn on a second semiconductor switching element, which is arranged in parallel with the capacitor and connected to a rectifier element, within a period in which the first semiconductor switching element is off.Type: GrantFiled: April 23, 2015Date of Patent: March 5, 2019Assignee: FANUC CORPORATIONInventors: Yasuo Nakashima, Akiyoshi Kawahara
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Publication number: 20180369943Abstract: A wire electrical discharge machining system includes: an electrode motion control unit for moving a wire electrode while keeping the wire electrode parallel to Z1-axis and bring the wire electrode into contact with a reference piece, and moving the wire electrode while keeping the wire electrode inclined with respect to the Z1-axis and bring the wire electrode into contact with the reference piece; an electrode position acquiring unit for acquiring a position of the wire electrode in an X1Y1Z1 orthogonal coordinate system when the wire electrode touches the reference piece; a piece position acquiring unit for acquiring a piece position of the reference piece in an X2Y2Z2 orthogonal coordinate system when the wire electrode touches the reference piece; and a relative positional relationship calculator for calculating a coordinate system relative positional relationship, based on the acquired positions.Type: ApplicationFiled: June 18, 2018Publication date: December 27, 2018Applicant: FANUC CORPORATIONInventors: Masashi Masuda, Akiyoshi Kawahara
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Patent number: 10124432Abstract: An electrical discharge machine of the present invention is provided with a machining tank stored with a machining fluid in which a workpiece is immersed for electrical discharge machining, a reservoir unit configured to store the machining fluid in order to supply to and recover the machining fluid from the machining tank, a machining tank non-storage condition detecting unit configured to detect that the machining fluid is not stored in the machining tank, an addable amount specifying unit configured to specify the amount of the machining fluid stored in the reservoir unit when it is detected that the machining fluid is not stored in the machining tank and specify an addable amount, which is an addable machining fluid amount, based on the capacity of the reservoir unit and the amount of the machining fluid stored in the reservoir unit, and a machining fluid adding unit configured to add the machining fluid in the addable amount or less.Type: GrantFiled: September 1, 2016Date of Patent: November 13, 2018Assignee: FANUC CORPORATIONInventors: Masashi Masuda, Akiyoshi Kawahara, Yasuo Nakashima
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Patent number: 10086458Abstract: The upper limit value for the axis feeding speed is set to the maximum speed that can secure the safety in a wire electrical discharge machine. In the case where the level of the process liquid is higher than a predetermined height, however, the upper limit value is made smaller. In order to prevent the process liquid from spilling to the outside of the process tank, the acceleration or the jerk may be changed instead of the axis feeding speed. In the case where the process liquid level is high, it is difficult for the process liquid to spill when the speed is adjusted slowly. In addition, the time constant may be increased or the instruction for speed may be changed from the linear type to the S shape type.Type: GrantFiled: March 29, 2016Date of Patent: October 2, 2018Assignee: FANUC CORPORATIONInventors: Yasuo Nakashima, Akiyoshi Kawahara
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Publication number: 20180214962Abstract: A wire electrical discharge machine includes: an electrode unit for supplying a machining current to an electrode gap; a switch for changing impedance between a machining power source and the electrode unit; and a controller for, at the time of a core retaining process, controlling the switch to set the impedance to be higher than the impedance in a cutting process and thereby suppressing the machining current flowing through the electrode gap.Type: ApplicationFiled: January 25, 2018Publication date: August 2, 2018Applicant: FANUC CORPORATIONInventors: Tomoyuki Furuta, Yasuo Nakashima, Akiyoshi Kawahara
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Patent number: 9987698Abstract: When machining of a workpiece is started in a wire electric discharge machine, before a voltage is applied between a wire electrode and the workpiece (a machining gap), practicable shaft feed control systems are discriminated on the basis of machining conditions set in advance. According to the discrimination, running into an inability state of continuity of machining and an accuracy failure after machining are prevented beforehand.Type: GrantFiled: September 19, 2013Date of Patent: June 5, 2018Assignee: FANUC CORPORATIONInventors: Tomoyuki Furuta, Akiyoshi Kawahara
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Patent number: 9950378Abstract: In a wire electric discharge machine, a discharge delay time is used to classify the inter-electrode state into three categories; a short-circuit state, small-gap state, and large-gap state. Based on this classification, the magnitude of a machining current supplied from a main discharge circuit is determined. If the discharge delay time is zero (i.e., if no electric discharge is generated) after the lapse of a predetermined time since the start of the application of a machining voltage to an inter-electrode gap by an auxiliary discharge circuit, the inter-electrode gap is determined to be short-circuited by machining chips. Thereupon, a short-circuit machining current is supplied from the main discharge circuit to the inter-electrode gap to remove the machining chips. In this way, establishment of a complete short-circuit state is prevented so that the machining efficiency is improved to increase the machining speed.Type: GrantFiled: April 1, 2016Date of Patent: April 24, 2018Assignee: FANUC CORPORATIONInventors: Tomoyuki Furuta, Shinji Yoda, Akiyoshi Kawahara, Yasuo Nakashima
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Publication number: 20180036815Abstract: An electrical discharge machine includes: a work tank to store the working fluid in order to perform electrical discharge machining; a sound collector to collect sound generated by electrical discharge machining and transmitted through the working fluid stored in the work tank; and a controller to perform a predetermined operation based on sound information collected by the sound collector.Type: ApplicationFiled: August 2, 2017Publication date: February 8, 2018Applicant: FANUC CORPORATIONInventors: Masashi Masuda, Akiyoshi Kawahara, Yasuo Nakashima, Tomoyuki Furuta
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Patent number: 9815132Abstract: In a wire electric discharge machine, a control unit is configured to deposit constituents of a wire electrode between a workpiece and a portion to be cut off from the workpiece to bond the workpiece and the portion to be cut off by outputting a signal for making an output voltage of a variable DC power supply lower than during normal machining and the on-time of a second switching element longer than during the normal machining, at least in a part of a machining path.Type: GrantFiled: July 2, 2015Date of Patent: November 14, 2017Assignee: FANUC CORPORATIONInventors: Yasuo Nakashima, Yasuo Hasegawa, Akiyoshi Kawahara
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Patent number: 9744608Abstract: A primary power supply charges a capacitor by turning on a switching element and, upon completion of charging, turns off the switching element. Then, an AC pulse voltage is applied to the gap between a wire electrode and a workpiece by alternately turning on and off a switching element present in a secondary power supply. After a dielectric breakdown occurs between the wire electrode and the workpiece, the switching element is turned on to connect the capacitor so that the capacitor supplies a pulse current for machining.Type: GrantFiled: December 29, 2014Date of Patent: August 29, 2017Assignee: FANUC CORPORATIONInventors: Hiroyuki Furukawa, Akiyoshi Kawahara
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Publication number: 20170197267Abstract: A wire electrical discharge machine is configured to perform removal machining of a workpiece by applying a voltage to a machining gap between a wire electrode and the workpiece through a feeder to generate electrical discharge and is provided with a feeder deterioration detection unit configured to detect deterioration of the feeder. The feeder deterioration detection unit includes a detection unit configured to detect a machining current value during the machining and a detection unit configured to detect the number of electrical discharges during the machining.Type: ApplicationFiled: December 30, 2016Publication date: July 13, 2017Inventors: Tomoaki MATSUNAGA, Akiyoshi KAWAHARA
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Publication number: 20170066070Abstract: An electrical discharge machine of the present invention is provided with a machining tank stored with a machining fluid in which a workpiece is immersed for electrical discharge machining, a reservoir unit configured to store the machining fluid in order to supply to and recover the machining fluid from the machining tank, a machining tank non-storage condition detecting unit configured to detect that the machining fluid is not stored in the machining tank, an addable amount specifying unit configured to specify the amount of the machining fluid stored in the reservoir unit when it is detected that the machining fluid is not stored in the machining tank and specify an addable amount, which is an addable machining fluid amount, based on the capacity of the reservoir unit and the amount of the machining fluid stored in the reservoir unit, and a machining fluid adding unit configured to add the machining fluid in the addable amount or less.Type: ApplicationFiled: September 1, 2016Publication date: March 9, 2017Inventors: Masashi MASUDA, Akiyoshi KAWAHARA, Yasuo NAKASHIMA
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Patent number: D998661Type: GrantFiled: October 20, 2020Date of Patent: September 12, 2023Assignee: FANUC CORPORATIONInventors: Yoshinori Makino, Akiyoshi Kawahara, Hisanori Kouda