Patents by Inventor Kuniharu Yamada
Kuniharu Yamada 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: 20230201940Abstract: The disclosure provides a wire electric discharge machine and a wire electric discharge machining method capable of detecting concentrated electric discharge in real time by a discharge position obtained from a preliminary discharge current, and calculating an accurate discharge position for use in measuring a plate thickness or the like. The wire electric discharge machine according to the disclosure includes a discharge position calculation circuit calculating a discharge position from the preliminary discharge current respectively detected through a current detector during a first period from a time when a waveform of the preliminary discharge current supplied to a machining gap, formed by a wire electrode and a workpiece, rises to a time when the preliminary discharge current reaches a constant current value, and a second period after the time when the preliminary discharge current reaches the constant current value to a time when a main discharge current is supplied.Type: ApplicationFiled: December 27, 2022Publication date: June 29, 2023Applicant: Sodick Co., Ltd.Inventors: KUNIHARU YAMADA, TOMOHITO HANAWA, YOSHIKI ENDO
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Patent number: 11534843Abstract: To automatically change and set machining conditions suitable for a plate thickness even when machining paths of a rough machining step and an end surface finishing step are different in level difference machining in which the plate thickness changes during machining. In a wire electric discharge machining method and a wire electric discharge machining apparatus of the disclosure, an XY-plane of a workpiece stand is divided into small regions to form a plurality of divided regions, and a plate thickness of the workpiece is detected and stored in association with the divided regions. Thereafter, whether there is a level difference ahead of a traveling direction of a machining path is estimated according to plate thickness information associated with the divided regions and a plate thickness of the workpiece at a current machining position, and machining conditions are changed.Type: GrantFiled: March 16, 2021Date of Patent: December 27, 2022Assignee: Sodick Co., Ltd.Inventors: Kuniharu Yamada, Kohei Matsuura
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Publication number: 20220111456Abstract: An electrical discharge machine includes a critical angle detection device that detects a critical angle of a machining fluid in which a corrosion inhibitor is added. The critical angle detection device includes a prism, a light source, an image sensor, an electrical circuit, and a slit. The prism has an incident surface, a boundary surface, a reflection surface, and an emission surface. The light source irradiates an incident light from the incident surface to the boundary surface. The image sensor includes a plurality of photodetectors that detect a reflection light. The electrical circuit calculates the critical angle by arithmetically processing output signals output from the plurality of photodetectors. The slit is arranged on an optical axis of the reflection light between the prism and the image sensor to block a scattered light.Type: ApplicationFiled: September 29, 2021Publication date: April 14, 2022Applicant: Sodick Co., Ltd.Inventor: Kuniharu YAMADA
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Publication number: 20220063008Abstract: An electric discharge machine includes a DC power supply, a main switching element, a polarity switching circuit, a pulse generator, a detector, and a discharge controller. The DC power supply supplies a current to a machining gap. The pulse generator switches the main switching element and one of a positive switching element and a reverse switching element of the polarity switching circuit at a predetermined switching frequency. The detector detects an interpolar voltage in the machining gap. The discharge controller includes a storage that stores a coefficient indicating a removal quantity per discharge count for each operation pattern, and a calculator that calculates the discharge count from the interpolar voltage and estimates the removal quantity from the discharge count and the coefficient according to the operation patterns.Type: ApplicationFiled: June 4, 2021Publication date: March 3, 2022Applicant: Sodick Co., Ltd.Inventors: Kuniharu YAMADA, Yoshiki ENDO, Tomohito HANAWA
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Publication number: 20210299771Abstract: To automatically change and set machining conditions suitable for a plate thickness even when machining paths of a rough machining step and an end surface finishing step are different in level difference machining in which the plate thickness changes during machining. In a wire electric discharge machining method and a wire electric discharge machining apparatus of the disclosure, an XY-plane of a workpiece stand is divided into small regions to form a plurality of divided regions, and a plate thickness of the workpiece is detected and stored in association with the divided regions. Thereafter, whether there is a level difference ahead of a traveling direction of a machining path is estimated according to plate thickness information associated with the divided regions and a plate thickness of the workpiece at a current machining position, and machining conditions are changed.Type: ApplicationFiled: March 16, 2021Publication date: September 30, 2021Applicant: Sodick Co., Ltd.Inventors: Kuniharu YAMADA, Kohei MATSUURA
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Patent number: 10730126Abstract: A power supply device for wire electric discharge machining includes: a first DC power supply; first switching elements between the first DC power supply and a machining gap; a second DC power supply; a second switching element between the second DC power supply and the machining gap; and a pulse generator controlling the first and second switching elements. The pulse generator is configured so that, in order to generate an electric discharge in the machining gap, the second switching element is switched on and the voltage of the second DC power supply is applied to the machining gap; the first switching element is switched on intermittently at a predetermined frequency in response to an electric discharge generation detection signal, and a series of current pulses is fed to the machining gap. The feeding of the series of current pulses is discontinued when the current pulses don't reach a reference current.Type: GrantFiled: September 18, 2013Date of Patent: August 4, 2020Assignee: SODICK CO., LTD.Inventor: Kuniharu Yamada
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Patent number: 9833852Abstract: Provided is a wire electrical discharge machining device which has a tension controller for maintaining the tension of a traveling wire electrode at a tension. The tension controller includes: an allowed tension calculation module for determining an allowed tension that is less than a wire breaking tension at which the wire electrode breaks; and a set tension generation module for generating the set tension in accordance with the allowed tension. When the set tension is greater than the allowed tension, the set tension generation module reduces the set tension. When the set tension is less than the allowed tension, the set tension generation module increases the set tension in such a way that the set tension does not exceed the allowed tension.Type: GrantFiled: October 19, 2011Date of Patent: December 5, 2017Assignee: SODICK CO., LTD.Inventors: Kuniharu Yamada, Masaki Kougo, Tomoyuki Yanagisawa
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Patent number: 9744607Abstract: A power supply system for wire electric discharge machining includes a first power supply circuit and a second power supply circuit. The first power supply circuit applies, to the machining gap, a voltage that induces a discharge. The second power supply circuit, which includes a low inductance line, supplies a current, which contributes to the machining, to the machining gap,. A blocking diode is series-connected between the low inductance line and the machining gap. A container, which has a contact surface contacting with the blocking diode and contains a cooling liquid, is provided.Type: GrantFiled: July 21, 2011Date of Patent: August 29, 2017Assignee: SODICK CO., LTD.Inventors: Kuniharu Yamada, Tomoyuki Yanagisawa
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Publication number: 20150246403Abstract: A power supply device for wire electric discharge machining includes: a first DC power supply; first switching elements between the first DC power supply and a machining gap; a second DC power supply; a second switching element between the second DC power supply and the machining gap; and a pulse generator controlling the first and second switching elements. The pulse generator is configured so that, in order to generate an electric discharge in the machining gap, the second switching element is switched on and the voltage of the second DC power supply is applied to the machining gap; the first switching element is switched on intermittently at a predetermined frequency in response to an electric discharge generation detection signal, and a series of current pulses is fed to the machining gap. The feeding of the series of current pulses is discontinued when the current pulses don't reach a reference current.Type: ApplicationFiled: September 18, 2013Publication date: September 3, 2015Inventor: Kuniharu Yamada
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Patent number: 8648275Abstract: 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: GrantFiled: February 26, 2010Date of Patent: February 11, 2014Assignee: Sodick Co., Ltd.Inventors: Kuniharu Yamada, Tomoyuki Yanagisawa
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Publication number: 20130240486Abstract: Provided is a wire electrical discharge machining device which has a tension controller for maintaining the tension of a traveling wire electrode at a tension. The tension controller includes: an allowed tension calculation module for determining an allowed tension that is less than a wire breaking tension at which the wire electrode breaks; and a set tension generation module for generating the set tension in accordance with the allowed tension. When the set tension is greater than the allowed tension, the set tension generation module reduces the set tension. When the set tension is less than the allowed tension, the set tension generation module increases the set tension in such a way that the set tension does not exceed the allowed tension.Type: ApplicationFiled: October 19, 2011Publication date: September 19, 2013Applicant: SODICK CO., LTD.Inventors: Kuniharu Yamada, Masaki Kougo, Tomoyuki Yanagisawa
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Publication number: 20130112659Abstract: A power supply system for wire electric discharge machining includes a first power supply circuit and a second power supply circuit. The first power supply circuit applies, to the machining gap, a voltage that induces a discharge. The second power supply circuit, which includes a low inductance line, supplies a current, which contributes to the machining, to the machining gap. A blocking diode is series-connected between the low inductance line and the machining gap. A container, which has a contact surface contacting with the blocking diode and contains a cooling liquid, is provided.Type: ApplicationFiled: July 21, 2011Publication date: May 9, 2013Applicant: SODICK CO., LTD.Inventors: Kuniharu Yamada, Tomoyuki Yanagisawa
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Publication number: 20110220615Abstract: 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: ApplicationFiled: February 26, 2010Publication date: September 15, 2011Applicant: SODICK CO., LTD.Inventors: Kuniharu Yamada, Tomoyuki Yanagisawa
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Patent number: 6281463Abstract: A power supply device for an electric discharge machine for supplying power to a work gap (6) formed between a work piece and a tool electrode, includes a parallel circuit in which a first power supply (8), a second power supply (36) and a capacitor (34) are connected in parallel and the second power supply can supply a larger voltage and a smaller current than the first power supply to the work gap. A switching element is connected between the parallel circuit and the work gap for pulsing power from the parallel circuit.Type: GrantFiled: April 6, 2000Date of Patent: August 28, 2001Assignee: Sodick Co., Ltd.Inventors: Yuji Kaneko, Hidetaka Hayashi, Kuniharu Yamada
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Patent number: 4460936Abstract: A condenser including a dielectric material exhibiting a ferroelectric phase wherein the dielectric constant-temperature characteristic of the condenser exhibits hysteresis loss of not more than 5% is provided. The dielectric constant-temperature characteristics are varied by regulating the particle diameter of the crystal and by providing an electrode material which reduces the loss. Hysteresis loss may also be reduced by including an oxide of a rare earth element or a metallic element of Group Va of the Periodic Table into a barium titanate dielectric component system.Type: GrantFiled: February 3, 1981Date of Patent: July 17, 1984Assignee: Kabushiki Kaisha Suwa SeikoshaInventors: Kuniharu Yamada, Yoshiyuki Gomi, Tsuneo Handa
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Patent number: 4109456Abstract: A ceramic capacitor operatively connected to a piezoelectric oscillator for compensating for the temperature dependence of the oscillator frequency is provided for thereby optimizing the accuracy of an electronic timepiece.Type: GrantFiled: July 7, 1975Date of Patent: August 29, 1978Assignee: Kabushiki Kaisha Suwa SeikoshaInventors: Kuniharu Yamada, Katsuhiro Teraishi
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Patent number: 4068285Abstract: A variable capacitor is provided wherein a reinforcing plate is utilized in the rotor assembly in order to increase the range of the capacitor. The capacitor includes the stator plate and first electrode, the stator plate supporting a lead pin and a rotor positioning member, the rotor positioning member being rotatably mounted thereon. The rotor positioning member rotatably supports a uniformly thick rotor assembly in rotatable friction contact with the stator plate and first electrode. The rotor assembly includes a dielectric, a second capacitor electrode and a reinforcing plate, the thickenss of the dielectric determining the minimum value of capacitance of the variable capacitor. The rotor assembly also includes a fixed spring secured to the positioning member, the lead pin and fixed spring being adapted to facilitate use of variable capacitor in small-size electronic instrumentation.Type: GrantFiled: May 5, 1976Date of Patent: January 10, 1978Assignee: Kabushiki Kaisha Suwa SeikoshaInventors: Kuniharu Yamada, Yukio Morozumi, Keiichi Iuchi
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Patent number: 4006969Abstract: In an electro-chromic display device having a display field, provision is made for showing a plurality of indicia in the same or overlapping regions, thereby increasing the range of indicia which can be displayed in a given area.Type: GrantFiled: December 8, 1975Date of Patent: February 8, 1977Assignee: Kabushiki Kaisha Suwa SeikoshaInventors: Akihiko Kouchi, Kunihiro Inoue, Hiroshi Takeshita, Kuniharu Yamada, Tsutomu Otake