公开(公告)号：US11031770B2

公开(公告)日：2021-06-08

申请号：US16099219

申请日：2017-04-26

Applicant: MAKITA CORPORATION

Inventor： Yuta Izutsu ,  Katsuhito Fujinami ,  Akira Ito

IPC: H02H3/20 ,  B25F5/00 ,  H02P27/06 ,  H02H7/122 ,  B23B45/02 ,  H02P29/024

Abstract: An electric working machine in one aspect of the present disclosure includes a main current-path, a driving unit including a motor and at least one first semiconductor-switching-element, a controller, a bypass current-path, a second semiconductor-switching-element, and a switch driver. The main current-path is arranged between a positive electrode and a negative electrode of a battery. The driving unit is situated in the main current path. The bypass current-path is arranged in parallel with the driving unit. The second semiconductor-switching-element is situated in the bypass current-path. The switch driver causes the second semiconductor-switching-element to interrupt the bypass current-path in an event that a voltage value of a drive voltage applied to the driving unit is less than a threshold value, and causes the second semiconductor-switching-element to complete the bypass current-path in an event that the voltage value is equal to or greater than the threshold value.

公开(公告)号：US12040687B2

公开(公告)日：2024-07-16

申请号：US17625068

申请日：2020-07-27

Applicant: MAKITA CORPORATION

Inventor： Takaharu Nakatsuka ,  Yuta Izutsu

IPC: H02K7/14 ,  H02K7/00 ,  H02K7/116 ,  H02K11/24 ,  H02K11/33 ,  B25B21/00 ,  B25F5/00

CPC classification number: H02K7/145 ,  H02K7/003 ,  H02K7/116 ,  H02K7/14 ,  H02K11/24 ,  H02K11/33 ,  B25B21/00 ,  B25F5/001

Abstract: A power tool includes a motor including a rotor and a stator disposed around the rotor; an output shaft to which a tip tool is attached and that is rotated by power generated by the motor; a torque sensor unit that is disposed between the stator and the output shaft in a front-rear direction parallel to a rotation axis of the motor and that is coupled to the output shaft; an amplifier circuit that amplifies a detection signal of the torque sensor unit; and a housing including a motor housing part for housing the motor and a grip part. The torque sensor unit is disposed forward of the stator. The grip part is disposed downward of the motor housing part. The amplifier circuit is disposed upward of the grip part. The amplifier circuit is disposed forward of a rear end part of the stator.

公开(公告)号：US12155273B2

公开(公告)日：2024-11-26

申请号：US17362473

申请日：2021-06-29

Applicant: MAKITA CORPORATION ,  MINEBEA MITSUMI INC.

Inventor： Takaharu Nakatsuka ,  Yuta Izutsu ,  Kotaro Eguchi ,  Kui Li

IPC: B25B21/00 ,  B25B23/147 ,  H02K7/10 ,  H02K7/14 ,  H02K11/02 ,  H02K11/24 ,  H02K11/30

Abstract: A screwing machine includes a motor, an output shaft, a twist portion, a plate portion, a strain gauge, an amplification circuit. The output shaft is driven by the motor. To the output shaft, a bit is attachable. The twist portion is hollow. To the twist portion, torque applied to the output shaft is transmitted through a transmission element. The output shaft is configured to be indirectly twisted by the torque applied to the output shaft. The plate portion is integrally formed with the twist portion. The strain gauge is disposed on the twist portion. The amplification circuit is disposed on the plate portion. To the amplification circuit, a signal from the strain gauge is input.

公开(公告)号：US11478842B1

公开(公告)日：2022-10-25

申请号：US17719481

申请日：2022-04-13

Applicant: MAKITA CORPORATION

Inventor： Yuta Izutsu ,  Kisho Sekido

IPC: B21J15/26 ,  B21J15/04 ,  B21J15/28 ,  B21J15/34 ,  B21J15/10

Abstract: A fastening tool includes a motor, an anvil, a pin-gripping part, a magnet having the north pole and the south pole aligned in a front-rear direction and configured to move integrally with the pin-gripping part in the front-rear direction, a first magnetic sensor having a first sensing surface, a second magnetic sensor having a second sensing surface and disposed rearward of the first magnetic sensor, and a control device configured to move the pin-gripping part rearward based on a detection result of the second magnetic sensor and to move the pin-gripping part forward based on a detection result of the first magnetic sensor. The first and second magnetic sensors are unipolar detection type sensors configured to detect a same specified pole of the magnet. Orientations of the first sensing surface and the second sensing surface relative to a movement axis of the magnet are opposite to each other.