초록

A retractor of a seatbelt apparatus to be installed in a vehicle is structured such that a Hall sensor and a magnetic disc as a mechanism configured to detect the position of a rotor in a motor are also used as mechanisms for detecting the amount of winding or unwinding a seatbelt.

대표청구항 ▼

What is claimed is: 1. A seatbelt retractor comprising: a hollow cylindrically shaped spool, wherein the spool is configured to have a seatbelt wound or unwound from an outer periphery of the spool; a motor configured to rotate the spool in a belt winding direction or a belt unwinding direction, wh

What is claimed is: 1. A seatbelt retractor comprising: a hollow cylindrically shaped spool, wherein the spool is configured to have a seatbelt wound or unwound from an outer periphery of the spool; a motor configured to rotate the spool in a belt winding direction or a belt unwinding direction, wherein the motor includes a shaft; a speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between a driving shaft of the motor and the spool, wherein the plurality of gears is a planetary gear set that includes a sun gear, a plurality of planetary gears, and an outside gear, wherein the sun gear is directly connected to the motor shaft so that a shaft of the speed-reduction mechanism and the motor shaft are the same; and a controller for controlling the operation of the motor, wherein the controller receives inputs from a rotor position sensor to thereby determine the winding and unwinding amount of the seatbelt. 2. The retractor of claim 1, wherein the motor includes a magnet as a rotor and a coil as a stator which are accommodated in a motor housing so that the stator is disposed around the rotor and is structured such that the driving shaft is rotated according to the rotation of the rotor. 3. The seatbelt retractor as claimed in claim 1, wherein the motor is accommodated in the cylindrical space of the spool. 4. The seatbelt retractor as claimed in claim 2, wherein the plurality of gears of the motor speed-reduction mechanism are arranged to extend on the same plane perpendicular to the axial direction of the motor housing. 5. The seatbelt retractor as claimed in claim 2, wherein the spool and the motor housing are supported by each other via a bearing mechanism disposed between an inner periphery of the spool and an outer periphery of the motor housing. 6. The seatbelt retractor as claimed in claim 1, wherein the seatbelt retractor is adapted to have such dimensions as to be used for a passenger in a rear seat of an vehicle. 7. The seatbelt retractor as claimed in claim 1, wherein the seatbelt retractor is adapted to be accommodated in an accommodating space in a pillar of an vehicle, wherein the pillar is located to a rear of an A-pillar of the vehicle. 8. The seatbelt retractor as claimed in claim 7, wherein in the state that the seatbelt retractor is accommodated in the accommodating space, the spool outer periphery of the spool extends in the longitudinal direction of a vehicle, and the length of the spool outer periphery in the width direction and the length of the accommodating space in the longitudinal direction of the vehicle are equal to each other. 9. The seatbelt retractor as claimed in claim 1, wherein the seatbelt retractor is adapted to be accommodated in an accommodating space in a seat of an vehicle. 10. The seatbelt retractor as claimed in claim 9, wherein in the state that the seatbelt retractor is accommodated in the accommodating space, the spool outer periphery of the spool extends in the longitudinal direction of a vehicle, and the length of the spool outer periphery in the width direction and the length of the accommodating space in the longitudinal direction of the vehicle are equal to each other. 11. A seatbelt apparatus comprising: a seatbelt retractor; and a seatbelt which is adapted to be worn by a vehicle occupant seated in a seat, wherein the seatbelt retractor comprises: a spool formed into a hollow cylindrical shape and is capable of winding the seatbelt onto a spool outer periphery or unwinding the seatbelt from the spool outer periphery; a motor configured to rotate the spool in the belt winding direction or the belt unwinding direction, wherein the motor includes a shaft; a motor speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between a driving shaft of the motor and the spool, wherein the plurality of gears is a planetary gear set that includes a sun gear, a plurality of planetary gears, and an outside gear, wherein the sun gear is directly connected to the motor shaft so that a shaft of the speed-reduction mechanism and the motor shaft are the same; a first control mechanism for controlling the operation of the motor; and a second control mechanism for controlling the operation of winding and unwinding of the seatbelt, wherein the motor uses a magnet as a rotor and a coil as a stator which are accommodated in a motor housing so that the stator is disposed around the rotor and is structured such that the driving shaft is rotated according to the rotation of the rotor, and wherein the motor comprises a first detecting mechanism for the first control mechanism, which detects the position of the rotor, and the first detecting mechanism is also used as a second detecting mechanism for the second control mechanism, which detects the winding amount and the unwinding amount of the seatbelt. 12. A vehicle, comprising: a seatbelt apparatus with a seatbelt retractor and a seatbelt adapted to be worn by a vehicle occupant seated in a seat, wherein the seatbelt retractor comprises: a spool formed into a hollow cylindrical shape and is capable of winding the seatbelt onto a spool outer periphery or unwinding the seatbelt from the spool outer periphery; a motor configured to rotate the spool in the belt winding direction or the belt unwinding direction, wherein the motor includes a shaft; a motor speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between a driving shaft of the motor and the spool, wherein the plurality of gears is a planetary gear set that includes a sun gear, a plurality of planetary gears, and an outside gear, wherein the sun gear is directly connected to the motor shaft so that a shaft of the speed-reduction mechanism and the motor shaft are the same; a first control mechanism for controlling the operation of the motor; and a second control mechanism for controlling the operation of winding and unwinding of the seatbelt, wherein the motor uses a magnet as a rotor and a coil as a stator which are accommodated in a motor housing so that the stator is disposed around the rotor and is structured such that the driving shaft is rotated according to the rotation of the rotor, wherein the motor comprises a first detecting mechanism for the first control mechanism, which detects the position of the rotor, and the first detecting mechanism is also used as a second detecting mechanism for the second control mechanism, which detects the winding amount and the unwinding amount of the seatbelt, and wherein the seatbelt apparatus is accommodated in an accommodating space in the vehicle. 13. A seatbelt apparatus comprising: a seatbelt retractor; and a seatbelt which is adapted to be worn by a vehicle occupant seated in a seat, wherein the seatbelt retractor comprises: a hollow cylindrically shaped spool, wherein the spool is configured to have a seatbelt wound or unwound from an outer periphery of the spool; a motor configured to rotate the spool in a belt winding direction or a belt unwinding direction, wherein the motor includes a shaft; a speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between a driving shaft of the motor and the spool, wherein the plurality of gears is a planetary gear set that includes a sun gear, a plurality of planetary gears, and an outside gear, wherein the sun gear is directly connected to the motor shaft so that a shaft of the speed-reduction mechanism and the motor shaft are the same; and a controller for controlling the operation of the motor, wherein the controller receives inputs from a rotor position sensor to thereby determine the winding and unwinding amount of the seatbelt. 14. The seatbelt apparatus of claim 13, wherein the motor includes a magnet as a rotor and a coil as a stator which are accommodated in a motor housing so that the stator is disposed around the rotor and is structured such that the driving shaft is rotated according to the rotation of the rotor. 15. A vehicle, comprising: a seatbelt apparatus with a seatbelt retractor and a seatbelt adapted to be worn by a vehicle occupant seated in a seat, wherein the seatbelt retractor comprises: a hollow cylindrically shaped spool, wherein the spool is configured to have a seatbelt wound or unwound from an outer periphery of the spool; a motor configured to rotate the spool in a belt winding direction or a belt unwinding direction, wherein the motor includes a shaft; a speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between a driving shaft of the motor and the spool, wherein the plurality of gears is a planetary gear set that includes a sun gear, a plurality of planetary gears, and an outside gear, wherein the sun gear is directly connected to the motor shaft so that a shaft of the speed-reduction mechanism and the motor shaft are the same; and a controller for controlling the operation of the motor, wherein the controller receives inputs from a rotor position sensor to thereby determine the winding and unwinding amount of the seatbelt. 16. The vehicle of claim 15, wherein the motor includes a magnet as a rotor and a coil as a stator which are accommodated in a motor housing so that the stator is disposed around the rotor and is structured such that the driving shaft is rotated according to the rotation of the rotor.