Patents by Inventor Kiyoshi Aoyama
Kiyoshi Aoyama 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).
-
Patent number: 11646639Abstract: A vibration driver drill as an electric power tool includes a brushless motor that includes a rotor and a sensor circuit board that detects a rotation of the rotor. The rotor includes a tubular rotor core and four permanent magnets held in the rotor core so as to extend in an axial direction of the rotor core. The sensor circuit board is adjacent to a front-end part (first end portion) of the rotor core. The rotor core is provided with a recessed groove on a side surface outward between the mutually adjacent permanent magnets. The recessed groove extends from the front-end part in the axial direction of the rotor core without reaching a rear-end part (second end portion) facing the front-end part.Type: GrantFiled: March 1, 2019Date of Patent: May 9, 2023Assignee: MAKITA CORPORATIONInventor: Kiyoshi Aoyama
-
Patent number: 11309811Abstract: An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.Type: GrantFiled: September 8, 2020Date of Patent: April 19, 2022Assignee: MAKITA CORPORATIONInventors: Kiyoshi Aoyama, Hitoshi Suzuki
-
Publication number: 20210091640Abstract: A vibration driver drill as an electric power tool includes a brushless motor that includes a rotor and a sensor circuit board that detects a rotation of the rotor. The rotor includes a tubular rotor core and four permanent magnets held in the rotor core so as to extend in an axial direction of the rotor core. The sensor circuit board is adjacent to a front-end part (first end portion) of the rotor core. The rotor core is provided with a recessed groove on a side surface outward between the mutually adjacent permanent magnets. The recessed groove extends from the front-end part in the axial direction of the rotor core without reaching a rear-end part (second end portion) facing the front-end part.Type: ApplicationFiled: March 1, 2019Publication date: March 25, 2021Applicant: MAKITA CORPORATIONInventor: Kiyoshi AOYAMA
-
Publication number: 20210083603Abstract: An electric working machine may include a brushless motor and a motor controller. The motor controller may include three upper switching elements, three lower switching elements, and a control unit. The control unit may be configured to execute a short-circuit braking operation for applying a braking force to the brushless motor by bringing the three upper switching elements into a non-conductive state and bringing the three lower switching elements into a conductive state. The control unit may be configured to start the short-circuit braking operation at a predetermined timing. When the short-circuit braking operation is started at the predetermined timing, polarities of induced voltages of first to third phase terminals of the brushless motor are reversed by a time when an electrical angle of the brushless motor increases by 180 degrees from the start of the short-circuit braking operation.Type: ApplicationFiled: September 8, 2020Publication date: March 18, 2021Applicant: MAKITA CORPORATIONInventors: Kiyoshi AOYAMA, Hitoshi SUZUKI
-
Patent number: 10778057Abstract: An electric power tool includes a brushless motor as a driving source. The brushless motor includes a stator and a rotor. The stator includes coils wound around in three phases. In a wire winding method of the coil of the stator, when the number of slots per phase is N, the number of series of the coils per phase is A, and the number of parallel of the coils per phase is B, a relation of N=A×B (note that, N is a natural number of 3 or more and 10 or less, A is a natural number of 1 or more, and B is a natural number of 2 or more) is satisfied.Type: GrantFiled: May 1, 2017Date of Patent: September 15, 2020Assignee: MAKITA CORPORATIONInventor: Kiyoshi Aoyama
-
Patent number: 10236739Abstract: The present application discloses an electric working machine. The electric working machine includes a motor including a stator. The stator includes: a stator core haring a plurality of tooth portions radially extending along a radial direction; and a first coil, a second coil, and a third coil wound on the tooth portions. A start end of the first coil and a finish end of the second coil, a start end of the second coil and a finish end of the third coil, and a start end of the third coil and a finish end of the first coil are led out within a range of 200 degrees from the stator.Type: GrantFiled: October 20, 2015Date of Patent: March 19, 2019Assignee: MAKITA CORPORATIONInventors: Kiyoshi Aoyama, Masanori Higashi, Takashi Momose
-
Patent number: 10084360Abstract: The present application discloses an electric working machine. The electric working machine includes: a motor including a rotor; a sensor board including a magnetic sensor for detecting magnetic variation due to rotation of the rotor; and a housing which contains the motor and the sensor board. in the electric working machine, the sensor board does not cover an entire circumference of the rotor. In the electric working machine, the sensor board has a portion covering the rotor, and a portion not covering the rotor.Type: GrantFiled: October 20, 2015Date of Patent: September 25, 2018Assignee: MAKITA CORPORATIONInventor: Kiyoshi Aoyama
-
Publication number: 20180013329Abstract: An electric power tool includes a brushless motor as a driving source. The brushless motor includes a stator and a rotor. The stator includes coils wound around in three phases. In a wire winding method of the coil of the stator, when the number of slots per phase is N, the number of series of the coils per phase is A, and the number of parallel of the coils per phase is B, a relation of N=A×B (note that, N is a natural number of 3 or more and 10 or less, A is a natural number of 1 or more, and B is a natural number of 2 or more) is satisfied.Type: ApplicationFiled: May 1, 2017Publication date: January 11, 2018Applicant: MAKITA CORPORATIONInventor: Kiyoshi AOYAMA
-
Patent number: 9364906Abstract: A hand-held power tool includes a motor having a stator and a rotor, the motor being configured to rotate the rotor at a speed of at least 40,000 rpm, an output shaft directly driven by the rotor, a tool accessory shaft configured to support a tool accessory, and a two-stage speed reducing transmission operably connecting the output shaft to the tool accessory shaft. The two-stage speed reducing transmission is configured to drive the tool accessory shaft at a rate less than the rotor speed, for example, at a rate less than or equal to 37.5% of the rotor speed.Type: GrantFiled: January 15, 2014Date of Patent: June 14, 2016Assignee: MAKITA CORPORATIONInventors: Kenji Abe, Masayoshi Okumi, Hidenori Nagasaka, Motohiro Omura, Masaaki Fukumoto, Kenji Shibata, Nobuyasu Furui, Masanori Higashi, Kiyoshi Aoyama
-
Publication number: 20160141932Abstract: The present application discloses an electric working machine. The electric working machine includes a motor including a stator. The stator includes: a stator core haring a plurality of tooth portions radially extending along a radial direction; and a first coil, a second coil, and a third coil wound on the tooth portions. A start end of the first coil and a finish end of the second coil, a start end of the second coil and a finish end of the third coil, and a start end of the third coil and a finish end of the first coil are led out within a range of 200 degrees from the stator.Type: ApplicationFiled: October 20, 2015Publication date: May 19, 2016Applicant: MAKITA CORPORATIONInventors: Kiyoshi AOYAMA, Masanori HIGASHI, Takashi MOMOSE
-
Publication number: 20160141939Abstract: The present application discloses an electric working machine. The electric working machine includes: a motor including a rotor; a sensor board including a magnetic sensor for detecting magnetic variation due to rotation of the rotor; and a housing which contains the motor and the sensor board. in the electric working machine, the sensor board does not cover an entire circumference of the rotor. In the electric working machine, the sensor board has a portion covering the rotor, and a portion not covering the rotor.Type: ApplicationFiled: October 20, 2015Publication date: May 19, 2016Inventor: Kiyoshi AOYAMA
-
Publication number: 20150020391Abstract: A hand-held power tool includes a motor having a stator and a rotor, the motor being configured to rotate the rotor at a speed of at least 40,000 rpm, an output shaft directly driven by the rotor, a tool accessory shaft configured to support a tool accessory, and a two-stage speed reducing transmission operably connecting the output shaft to the tool accessory shaft. The two-stage speed reducing transmission is configured to drive the tool accessory shaft at a rate less than the rotor speed, for example, at a rate less than or equal to 37.5% of the rotor speed.Type: ApplicationFiled: January 15, 2014Publication date: January 22, 2015Applicant: MAKITA CORPORATIONInventors: Kenji ABE, Masayoshi OKUMI, Hidenori NAGASAKA, Motohiro OMURA, Masaaki FUKUMOTO, Kenji SHIBATA, Nobuyasu FURUI, Masanori HIGASHI, Kiyoshi AOYAMA
-
Publication number: 20140243458Abstract: Provided is a powdery hydrophilic polymer by aggregating a hydrophilic polymer comprising a water-in-oil emulsion in a liquid form by emulsion breaking and granulating the aggregate, followed by drying. As an emulsion breaker, ionic surfactants, nonionic surfactants having an HLB value of 11 to 20, or oil-soluble polymer compounds having a hydrophilic group and a hydrophobic group can be used. The powdery hydrophilic polymer obtained by this method exhibits excellent effects as a flocculating agent.Type: ApplicationFiled: January 13, 2012Publication date: August 28, 2014Applicant: HYMO CORPORATIONInventors: Manabu Tonami, Kiyoshi Aoyama, Kazuyuki Hirata
-
Patent number: 7869913Abstract: A vehicle power supply apparatus has first and second engine-driven electrical generators and first and second storage batteries, the first generator supplying a stable voltage to the first battery and a first set of loads, and the second generator supplying the second battery and a second set of loads, which can tolerate supply voltage variations. Operation of the second generator and charging/discharging of the second battery are controlled to maintain the total engine torque applied to the generators at a level whereby fuel consumption is reduced, while the supply voltage of the variation-tolerant loads is allowed to vary substantially.Type: GrantFiled: June 27, 2007Date of Patent: January 11, 2011Assignee: Denso CorporationInventors: Kiyoshi Aoyama, Hiroshi Tamura, Akira Kato
-
Publication number: 20080215199Abstract: The vehicle-use dual voltage type power supply apparatus including a high voltage power supply system and a low voltage power supply system has a configuration that the target power generation cost is calculated individually for each of the two power supply systems in accordance with SOC as a variable of its own battery, so that the electricity cost reduction type power generation control can be performed individually for each of the two power supply systems.Type: ApplicationFiled: December 17, 2007Publication date: September 4, 2008Applicant: DENSO CORPORATIONInventors: Kiyoshi Aoyama, Hiroshi Tamura, Akira Kato
-
Publication number: 20080097664Abstract: A vehicle power supply apparatus has first and second engine-driven electrical generators and first and second storage batteries, the first generator supplying a stable voltage to the first battery and a first set of loads, and the second generator supplying the second battery and a second set of loads, which can tolerate supply voltage variations. Operation of the second generator and charging/discharging of the second battery are controlled to maintain the total engine torque applied to the generators at a level whereby fuel consumption is reduced, while the supply voltage of the variation-tolerant loads is allowed to vary substantially.Type: ApplicationFiled: June 27, 2007Publication date: April 24, 2008Applicant: DENSO CORPORATIONInventors: Kiyoshi Aoyama, Hiroshi Tamura, Akira Kato