MOTOR RETRACTOR

Abstract

A motor retractor, comprising: a winding shaft which winds up a webbing for restraining a vehicle passenger; a motor which rotates the winding shaft in a webbing winding-up direction; and a control portion which, after release of the webbing wearing state of the passenger: drives the motor to cause the webbing to be wound up around the winding shaft; stops the motor when an overload on the motor is detected during the winding-up; redrives the motor after a predetermined time having elapsed after the motor is stopped due to detection of the overland, and adjusts, at the time of the redriving, a driving state of the motor according to the time of driving the motor that has elapsed before the overload detection, is provided.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front sectional view schematically illustrating the overall configuration of a motor retractor according to a first embodiment of the present invention;

FIG. 2A is a timing chart illustrating the relationship between a current to be supplied to a motor by a control portion of a motor retractor according to the first embodiment of the present invention, and time;

FIG. 2B is a timing chart illustrating the relationship between the current to be supplied to the motor by the control portion of the motor retractor according to the first embodiment of the present invention, and time;

FIG. 2C is a timing chart illustrating the relationship between the current to be supplied to the motor by the control portion of the motor retractor according to the first embodiment of the present invention and the time;

FIG. 2D is a timing chart illustrating the relationship between the current to be supplied to the motor by the control portion of the motor retractor according to the first embodiment of the present invention, and time; and

FIG. 3 is a timing chart illustrating the relationship between the current to be supplied to the motor by the control portion of a motor retractor according to a second embodiment of the present invention, and time.

Claims

1. A motor retractor, comprising: a winding shaft which winds up a webbing for restraining a vehicle passenger;a motor which rotates the winding shaft in a webbing winding-up direction; anda control portion which, after release of the webbing wearing state of the passenger: drives the motor to cause the webbing to be wound up around the winding shaft;stops the motor when an overload on the motor is detected during the winding-up;redrives the motor after a predetermined time having elapsed after the motor is stopped due to detection of the overland, andadjusts, at the time of the redriving, a driving state of the motor according to the time of driving the motor that has elapsed before the overload detection.

2. The motor retractor of claim 1, wherein the control portion adjusts the driving state of the motor by changing the magnitude of a voltage applied to the motor.

3. The motor retractor of claim 1, wherein, when the time of driving the motor that has elapsed before the overload detection is equal to or longer than a preset time, the control portion lowers the magnitude of a supply current to the motor at the time of the redriving.

4. The motor retractor of claim 2, wherein, when the time of driving the motor that has elapsed before the overload detection is equal to or longer than a preset time, the control portion lowers the magnitude of a supply current to the motor at the time of the redriving.

5. The motor retractor of claim 1, wherein, when the time of driving the motor that has elapsed before the overload detection is equal to or longer than a preset time, the control portion shortens a time of driving the motor at the time of the redriving.

6. The motor retractor of claim 1, wherein, when a preset time has elapsed after the motor is driven for the first time following the release of the webbing wearing state, the control portion lowers the magnitude of a supply current to the motor.

7. A motor retractor comprising: a winding shaft which winds up a webbing for restraining a vehicle passenger;a motor which rotates the winding shaft in a webbing winding-up direction; anda control portion which, after release of a webbing wearing state of the passenger: feeds power to the motor to cause the webbing to be wound up around the winding shaft;interrupts the power feeding to the motor when an overload on the motor is detected during the winding; andgradually increases the magnitude of a current to resume the power feeding to the motor after the interruption of power feeding to the motor.

8. The motor retractor of claim 7, wherein the control portion decreases the magnitude of a stationary current for the motor after the resumption of the power feeding to a value that is smaller than the magnitude of the stationary current for the motor before the overload detection.