US 12,273,055 B2
Motor device, wiper device, and motor control method
Ryo Ohori, Gunma (JP); Tsuyoshi Osawa, Gunma (JP); and Atsushi Mochida, Gunma (JP)
Assigned to MITSUBA Corporation, Gunma (JP)
Appl. No. 18/035,295
Filed by MITSUBA Corporation, Gunma (JP)
PCT Filed Mar. 31, 2022, PCT No. PCT/JP2022/016589
§ 371(c)(1), (2) Date May 4, 2023,
PCT Pub. No. WO2023/067828, PCT Pub. Date Apr. 27, 2023.
Claims priority of application No. 2021-172965 (JP), filed on Oct. 22, 2021.
Prior Publication US 2023/0421084 A1, Dec. 28, 2023
Int. Cl. H02P 29/00 (2016.01); H02P 23/14 (2006.01); H02P 27/08 (2006.01)
CPC H02P 23/14 (2013.01) [H02P 27/08 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A motor device, comprising:
a motor that is rotationally driven;
a drive signal generator that controls a duty ratio indicating a drive output of the motor so as not to exceed a duty ratio upper limit value, and generates a drive signal corresponding to the duty ratio;
an inverter that outputs an output signal for rotationally driving the motor based on the drive signal;
a rotation speed detector that detects a rotation speed of the motor;
an acceleration detector that detects whether the motor is accelerating; and
an upper limit value setting part that changes the duty ratio upper limit value to a second upper limit value higher than a preset first upper limit value in response to rotation of the motor being accelerating, wherein
the upper limit value setting part disables a changing process of changing from the first upper limit value to the second upper limit value in response to the rotation speed of the motor being equal to or less than a threshold value.
 
6. A motor control method for controlling a motor that is rotationally driven by an output signal output by an inverter based on a drive signal, the motor control method comprising:
drive signal generating in which a drive signal generator controls a duty ratio indicating a drive output of the motor so as not to exceed a duty ratio upper limit value, and generates the drive signal corresponding to the duty ratio;
rotation speed detecting in which a rotation speed detector detects a rotation speed of the motor;
acceleration detecting in which an acceleration detector detects whether the motor is accelerating;
upper limit value setting in which an upper limit value setting part changes the duty ratio upper limit value to a second upper limit value higher than a preset first upper limit value in response to rotation of the motor being accelerating; and
upper limit value setting disabling in which the upper limit value setting part disables the upper limit value setting in response to the rotation speed of the motor being equal to or less than a threshold value.