Patents by Inventor Toshiaki Koizumi
Toshiaki Koizumi 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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Patent number: 9769990Abstract: A power tool includes: a power source (7); a tip tool (2); two switches (SW1,SW2); and a control unit (6e). The tip tool (2) is configured to be driven by the power source (7). The two switches (SW1,SW2) are configured to be turned on for activating the power source (7). The control unit (6e) is configured to control the power source (7) in accordance with on/off of the two switches (SW1,SW2), and operate if at least one of the two switches (SW1,SW2) is turned on.Type: GrantFiled: October 31, 2013Date of Patent: September 26, 2017Assignee: Hitachi Koki Co., Ltd.Inventors: Toshiaki Koizumi, Kazutaka Iwata, Yasutaka Shimizu
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Patent number: 9768713Abstract: An electric tool includes a brushless motor and an output part, which is driven by the brushless motor and to which a tip tool is mounted, and a tumbler switch. The tumbler switch applies, to the control unit, a stop signal for stopping the brushless motor at a neutral position, a forward rotation signal for forward rotating the brushless motor by an operation in a first direction, and a reverse rotation signal for reversely rotating the brushless motor by an operation in a second direction.Type: GrantFiled: August 26, 2014Date of Patent: September 19, 2017Assignee: HITACHI KOKI CO., LTD.Inventors: Toshiaki Koizumi, Naoki Tadokoro, Kazutaka Iwata, Eiji Nakayama
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Publication number: 20170194670Abstract: A power tool includes a motor and control means for controlling the motor. The motor is capable of being driven by power supplied from a battery pack including a battery cell. The control means is configured to continue to rotate the motor even when a motor-halt signal is inputted from the battery pack. With this structure, the power tool can be used continuously without need to halt rotation of the motor, even when receiving a halt signal, such as an overdischarge detection signal or an overcurrent detection signal.Type: ApplicationFiled: May 22, 2015Publication date: July 6, 2017Inventors: Yoshikazu KAWANO, Nobuhiro TAKANO, Toshiaki KOIZUMI, Kazuhiko FUNABASHI, Kenichirou YOSHIDA, Takao ARADACHI
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Publication number: 20170190027Abstract: In order to provide an electric tool such that the capacitances of noise-suppressing film capacitors can be increased without increasing the diameter of a handle section, the housing of the electric tool comprises: a body section that stores a brushless motor, a striking mechanism part, and a portion of an output part; a handle section, whose one end is connected to the body section; and a storage section that is formed on the other end of the handle section. A pair of film capacitors for removing noise generated from an inverter circuit are mounted on a capacitor substrate and stored side by side inside the handle section. The film capacitors are connected in parallel with each other, thereby providing a capacitor having a larger total capacitance than before.Type: ApplicationFiled: May 22, 2015Publication date: July 6, 2017Applicant: Hitachi Koki Co., Ltd.Inventors: Toshiaki KOIZUMI, Takuya YOSHINARI
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Publication number: 20170070168Abstract: An electric tool including a motor configured to be driven by a PWM control of a semiconductor switching element by using a power supply, a power transmission mechanism configured to transmit a rotation of the motor to an end tool, and a controller configured to control a rotation of the motor by a duty ratio of a PWM signal, wherein the controller is configured to set the duty ratio to a reference duty ratio less than 100% when a voltage of the power supply applied to the electric tool is within a predetermined range including a rated voltage of the electric tool, and wherein the controller is configured to drive the motor by setting the duty ratio to be higher than the reference duty ratio when the voltage of the power supply applied to the electric tool is lower than the predetermined range.Type: ApplicationFiled: March 25, 2015Publication date: March 9, 2017Inventors: Nobuhiro Takano, Kazutaka Iwata, Toshiaki Koizumi, Naoki Tadokoro, Hiroshi Haga, Shinichirou Satou
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Publication number: 20170012572Abstract: To provide a work tool capable of suppress temperature rise in a motor or a switching element. The work tool includes: a motor; a switching element switchable between an ON-state and an OFF-state, the switching element allowing a current to flow through the motor during the ON-state, the switching element prohibiting a current from flowing through the motor during the OFF-state; target rotation number setting means for setting a target rotation number of the motor; rotation number controlling means for controlling the motor such that the rotation number thereof is brought in coincidence with the target rotation number by changing an ON-duration, during which the switching element is in the ON-state, in one switching period of the switching element; and temperature detecting means for detecting at least one of a temperature of the motor and a temperature of the switching element.Type: ApplicationFiled: January 23, 2015Publication date: January 12, 2017Inventors: Nobuhiro Takano, Yoshikazu Kawano, Toshiaki Koizumi, Hideyuki Tanimoto, Kazutaka Iwata, Shigeharu Ushiwata
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Patent number: 9457459Abstract: A power tool includes a motor, an impact mechanism, an output unit, a circuit board, a housing, and a power cord. The circuit board includes a power-source circuit board configured to convert alternate current into direct current and a control circuit board. The housing includes a body section, a board accommodating section, and a handle section. The board accommodating section accommodates the circuit board. The handle section has one end portion connected to the body section and another end portion connected to the board accommodating section. The power cord extends from the board accommodating section. The power cord is positioned opposed to the handle section with respect to the board accommodating section. The control circuit board is located at a position close to the handle section in the board accommodating section. The power-source circuit board is located between the control circuit board and the power cord.Type: GrantFiled: December 27, 2011Date of Patent: October 4, 2016Assignee: Hitachi Koki Co., Ltd.Inventors: Naoki Tadokoro, Ken Miyazawa, Hajime Kikuchi, Toshiaki Koizumi
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Publication number: 20160250743Abstract: An electrical power tool capable of suppressing increase in a size of a device main body in a radial direction of an electrical motor is provided. A driver which drives a distal end tool with a power of an electrical motor includes: a casing in which the electrical motor is provided; a driven gear and a spindle which are arranged eccentrically with respect to an output shaft of the electrical motor and which transmit power of the output shaft to the distal end tool; and a power supply circuit unit arranged inside the casing. And, an arrangement region of the driven gear and the spindle and an arrangement region of the power supply circuit unit are at least partially overlapped with each other in a circumferential direction centering the output shaft.Type: ApplicationFiled: November 17, 2014Publication date: September 1, 2016Inventors: Hajime KIKUCHI, Takuya YOSHINARI, Toshiaki KOIZUMI
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Publication number: 20160204718Abstract: An electric tool includes a brushless motor and an output part, which is driven by the brushless motor and to which a tip tool is mounted, and a tumbler switch. The tumbler switch applies, to the control unit, a stop signal for stopping the brushless motor at a neutral position, a forward rotation signal for forward rotating the brushless motor by an operation in a first direction, and a reverse rotation signal for reversely rotating the brushless motor by an operation in a second direction.Type: ApplicationFiled: August 26, 2014Publication date: July 14, 2016Inventors: Toshiaki Koizumi, Naoki Tadokoro, Kazutaka Iwata, Eiji Nakayama
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Publication number: 20160197573Abstract: An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.Type: ApplicationFiled: March 17, 2016Publication date: July 7, 2016Inventors: Kazuhiko Iwata, Toshiaki Koizumi
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Publication number: 20160111984Abstract: It is an object of the invention to provide a power tool capable of preventing damage of a switching element while maintaining drive power of a motor even when being connected to a power supply of different voltage. An impact driver 1 includes a motor 3; a rectifying circuit 23; an inverter circuit 20; and an arithmetic part 24. The rectifying circuit 23 is configured to rectify an input voltage from a commercial power supply 30. The inverter circuit 20 is configured to supply a rectified voltage output from the rectifying circuit 23 to the motor 3 as drive power. The arithmetic part 24 is configured to suppress occurrence of overcurrent where current flowing through the motor exceeds a predetermined current value.Type: ApplicationFiled: May 16, 2014Publication date: April 21, 2016Inventors: Toshiaki Koizumi, Kazutaka Iwata
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Publication number: 20150289451Abstract: A power tool includes: a power source (7); a tip tool (2); two switches (SW1,SW2); and a control unit (6e). The tip tool (2) is configured to be driven by the power source (7). The two switches (SW1,SW2) are configured to be turned on for activating the power source (7). The control unit (6e) is configured to control the power source (7) in accordance with on/off of the two switches (SW1,SW2), and operate if at least one of the two switches (SW1,SW2) is turned on.Type: ApplicationFiled: October 31, 2013Publication date: October 15, 2015Inventors: Toshiaki Koizumi, Kazutaka Iwata, Yasutaka Shimizu
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Publication number: 20150288259Abstract: An electric power tool 1 has a motor 3, a housing 2, a power cord 9, and a power supply control circuit portion 8. The housing 2 has a body portion 21 for accommodating the motor, a substrate accommodating portion 23 for accommodating a substrate on which a control substrate for operating the motor 3 is mounted, a handle portion 22 having one end connected to the body portion 21 and another end connected to the substrate accommodating portion 23. The power cord 9 extends from the substrate accommodating portion 23 and is connected to an AC power supply. The power supply circuit portion 8 has a choke coil 86 and a film capacitor 88 for filtering noise, and converts AC power supplied through the power cord 9 to DC power. The choke coil 86 and a film capacitor 88 are accommodated in the substrate accommodating portion 23. Accordingly, the handle portion can be formed shorter, and assemblability of the electric power tool can be improved.Type: ApplicationFiled: October 25, 2013Publication date: October 8, 2015Applicant: Hitachi Koki Co., Ltd.Inventor: Toshiaki Koizumi
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Publication number: 20140001993Abstract: An electric power tool includes: a brushless motor having a plurality of stator windings and configured to rotate in accordance with voltages applied to the plurality of stator windings, an induced voltage being generated in accordance with a rotation of the brushless motor; a rectifier circuit configured to rectify an AC voltage; a smoothing capacitor configured to smooth the AC voltage rectified by the rectifier circuit to a pulsation voltage having a maximum value larger than the induced voltage and a minimum value smaller than the induced voltage; and an inverter circuit configured to perform switching operations to output the pulsation voltage to the plurality of stator windings by rotation.Type: ApplicationFiled: March 19, 2012Publication date: January 2, 2014Applicant: Hitachi Koki Co., Ltd.Inventors: Kazutaka Iwata, Toshiaki Koizumi
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Publication number: 20130000934Abstract: A power tool includes a motor, an impact mechanism, an output unit, a circuit board, a housing, and a power cord. The circuit board includes a power-source circuit board configured to convert alternate current into direct current and a control circuit board. The housing includes a body section, a board accommodating section, and a handle section. The board accommodating section accommodates the circuit board. The handle section has one end portion connected to the body section and another end portion connected to the board accommodating section. The power cord extends from the board accommodating section. The power cord is positioned opposed to the handle section with respect to the board accommodating section. The control circuit board is located at a position close to the handle section in the board accommodating section. The power-source circuit board is located between the control circuit board and the power cord.Type: ApplicationFiled: December 27, 2011Publication date: January 3, 2013Applicant: Hitachi Koki Co., Ltd.Inventors: Naoki Tadokoro, Ken Miyazawa, Hajime Kikuchi, Toshiaki Koizumi
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Patent number: 7476977Abstract: A chip mounting substrate for bonding a semiconductor chip to a substrate, comprises a solder layer on the substrate, the solder layer being connectable to a semiconductor chip, wherein the solder layer comprises a layer including ?-phase crystal grains of an Au—Sn alloy at a surface of the solder layer. The solder layer comprising a layer including ?-phase crystal grains of an Au—Sn alloy is formed at a surface of the solder layer. On mounting a semiconductor chip on the substrate, the substrate and the solder layer are heated and an image of the solder layer is shot to perform an image evaluation to detect the timing of mounting the semiconductor chip on the solder layer of the substrate and a position of the chip.Type: GrantFiled: February 14, 2005Date of Patent: January 13, 2009Assignee: Hitachi, Ltd.Inventors: Takeru Fujinaga, Kazuhiro Hirose, Hideaki Takemori, Toshiaki Koizumi
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Patent number: 7452798Abstract: A chip mounting substrate for bonding a semiconductor chip to a substrate, comprises a solder layer on the substrate, the solder layer being connectable to a semiconductor chip, wherein the solder layer comprises a layer including ?-phase crystal grains of an Au—Sn alloy at a surface of the solder layer. The solder layer comprising a layer including ?-phase crystal grains of an Au—Sn alloy is formed at a surface of the solder layer. On mounting a semiconductor chip on the substrate, the substrate and the solder layer are heated and an image of the solder layer is shot to perform an image evaluation to detect the timing of mounting the semiconductor chip on the solder layer of the substrate and a position of the chip.Type: GrantFiled: May 11, 2007Date of Patent: November 18, 2008Assignee: Hitachi, Ltd.Inventors: Takeru Fujinaga, Kazuhiro Hirose, Hideaki Takemori, Toshiaki Koizumi
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Publication number: 20070207557Abstract: A chip mounting substrate for bonding a semiconductor chip to a substrate, comprises a solder layer on the substrate, the solder layer being connectable to a semiconductor chip, wherein the solder layer comprises a layer including ?-phase crystal grains of an Au—Sn alloy at a surface of the solder layer. The solder layer comprising a layer including ?-phase crystal grains of an Au—Sn alloy is formed at a surface of the solder layer. On mounting a semiconductor chip on the substrate, the substrate and the solder layer are heated and an image of the solder layer is shot to perform an image evaluation to detect the timing of mounting the semiconductor chip on the solder layer of the substrate and a position of the chip.Type: ApplicationFiled: May 11, 2007Publication date: September 6, 2007Applicant: HITACHI, LTD.Inventors: Takeru FUJINAGA, Kazuhiro HIROSE, Hideaki TAKEMORI, Toshiaki KOIZUMI
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Publication number: 20050212140Abstract: A chip mounting substrate for bonding a semiconductor chip to a substrate, comprises a solder layer on the substrate, the solder layer being connectable to a semiconductor chip, wherein the solder layer comprises a layer including ?-phase crystal grains of an Au—Sn alloy at a surface of the solder layer. The solder layer comprising a layer including ?-phase crystal grains of an Au—Sn alloy is formed at a surface of the solder layer. On mounting a semiconductor chip on the substrate, the substrate and the solder layer are heated and an image of the solder layer is shot to perform an image evaluation to detect the timing of mounting the semiconductor chip on the solder layer of the substrate and a position of the chip.Type: ApplicationFiled: February 14, 2005Publication date: September 29, 2005Inventors: Takeru Fujinaga, Kazuhiro Hirose, Hideaki Takemori, Toshiaki Koizumi
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Patent number: 5477154Abstract: An electromagnetic disturbance power (EDP) checker measures disturbance waves of an equipment under test (EUT), that is, a small electric appliance having a power cord. The EDP checker is capable of detecting and measuring disturbance waves even in sites more confined and having more external disturbance waves than in absorbing clamp method. The EDP checker includes a VHF current probe 2, a matching circuit 3 having input impedance matched at a reception frequency of a measuring equipment (receiver) 6 connected to the VHF current probe 2, and a circuit separating mains 4 for designating terminal impedance of the matching circuit 3 and eliminating influence of power source impedance. Power is supplied from the circuit separating mains 4 to drive the EUT 5 connected to the VHF current probe 2. The maximum value of disturbance power generated by the EUT 5 and supplied through the power cord 12 is measured by the measuring equipment 6 connected to the VHF current probe 2.Type: GrantFiled: June 30, 1994Date of Patent: December 19, 1995Assignee: Hitachi Koki Co., Ltd.Inventors: Kumio Takahashi, Shun Suzuki, Toshiaki Koizumi