JP2013121749A - Webbing take-up device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the rotation limit load to a take-up shaft necessary to limit the transmission of the rotation of a motor to the take-up shaft with a simple structure.SOLUTION: An overload release mechanism 52 is operated, when a rotation limit load more than a first limit load acts on take-up shaft 20 when motor 50 is driven by the low speed, and the winding of webbing 22 to take-up shaft 20 is limited in the state in which webbing 22 is not attached to the occupant in webbing take-up device 10. Meanwhile, a high load mechanism 64 limits the operation of an overload release mechanism 52 through a communication gear 74, even when the rotation limit load more than the first limit load acts on the take-up shaft 20, when the motor 50 is driven by the high speed, and the webbing 22 is wound up to the take-up shaft 20 in the state where the webbing 22 is worn by the occupant. Therefore, the rotation limit load to the take-up shaft 20 necessary can be increased by a simple structure, since the transmission of the rotation of the motor 50 to the take-up shaft 20 is limited.

Description

  The present invention relates to a webbing take-up device that rotates a take-up shaft on which a webbing is taken up by transmitting rotation of a motor.

  In the seat belt retractor described in Patent Document 1 below, the first speed reduction mechanism is provided with a slipping mechanism. When the motor is rotated at a low speed, the slipping mechanism is not operated, so that the rotation of the motor is the first. 1 is transmitted to the spool via the speed reduction mechanism, and the spool is rotated with a low torque in the winding direction.

  Further, when the motor is rotated at a high speed, the sliding mechanism is operated, whereby the rotation of the motor is transmitted to the spool via the second reduction mechanism, and the spool is rotated with high torque in the winding direction. .

  Further, when the motor is rotated at a low speed, if the rotation limiting load acts on the spool in the pulling direction and the sliding mechanism is operated, transmission of the rotation of the motor to the spool is limited.

  However, in this seat belt retractor, the load on the slipping mechanism necessary for operating the slipping mechanism cannot be changed. For this reason, when the rotation of the motor is transmitted to the spool via the first reduction mechanism, the slip of the spool, which is a rotation limiting load on the spool, is necessary for limiting the transmission of the rotation of the motor to the spool. The load cannot be increased.

  Thus, in order to increase the sliding load of the spool, the second reduction mechanism needs to transmit the rotation of the motor to the spool independently of the sliding mechanism, and the rotation of the motor is transmitted to the spool independently of the sliding mechanism. Therefore, the configuration is complicated.

Japanese Patent No. 4467688

  In view of the above fact, the present invention is to obtain a webbing take-up device capable of increasing the rotation limiting load on the take-up shaft necessary for limiting the transmission of rotation of the motor to the take-up shaft with a simple configuration. It is aimed.

  The webbing take-up device according to claim 1 is a take-up shaft on which a webbing to be mounted on an occupant is taken up, a transmission mechanism connected to the take-up shaft, a communication mechanism connected to the transmission mechanism, and rotation transmitted to the transmission shaft. A motor that rotates the winding shaft by being transmitted to the winding shaft through a mechanism; and a transmission mechanism that transmits rotation of the motor side to the winding shaft side, and the winding A first limiting mechanism that is activated when a rotation limiting load applied to the take-up shaft is greater than or equal to a first limit load and restricts transmission of rotation on the motor side to the take-up shaft side; A second limiting mechanism for limiting the operation of the first limiting mechanism and transmitting the rotation of the first limiting mechanism on the motor side to the winding shaft side.

  The webbing take-up device according to a second aspect is the webbing take-up device according to the first aspect, wherein the second limiting mechanism corresponds to the winding amount or the drawing amount of the webbing with respect to the winding shaft. 1 Switching between the permissible and restricted operation of the limiting mechanism.

  The webbing take-up device according to claim 3 is the webbing take-up device according to claim 1 or 2, wherein the second restricting mechanism is the first restricting mechanism when the webbing is attached to an occupant. Limit operation.

  The webbing take-up device according to claim 4 is the webbing take-up device according to any one of claims 1 to 3, wherein the second limiting mechanism is a rotation limit that is applied to the take-up shaft. Actuated when the load is greater than or equal to the second limit load greater than the first limit load, the transmission of rotation on the motor side to the winding shaft side is limited.

  The webbing take-up device according to a fifth aspect is the webbing take-up device according to any one of the first to fourth aspects, wherein rotation of the motor in the positive direction is performed via the transmission mechanism. By being transmitted to the take-up shaft, the take-up shaft is rotated in the take-up direction so that the webbing is taken up on the take-up shaft, and rotation of the motor in the reverse direction is performed via the transmission mechanism. By being transmitted to the take-up shaft, the take-up shaft is rotated in the pull-out direction, and the webbing is drawn out from the take-up shaft.

  In the webbing take-up device according to claim 1, the transmission mechanism is connected to the take-up shaft, and the motor is connected to the transfer mechanism, and the rotation of the motor is transmitted to the take-up shaft through the transfer mechanism. Thus, the winding shaft is rotated.

  Further, the transmission mechanism is provided with a first limiting mechanism, and the first limiting mechanism transmits the rotation on the motor side to the winding shaft side. Further, when the rotation limiting load applied to the winding shaft is equal to or higher than the first limiting load, the first limiting mechanism is activated, and the rotation of the first limiting mechanism on the motor side is transmitted to the winding shaft side. By being limited, transmission of the rotation of the motor to the winding shaft is limited. For this reason, the sliding load of the winding shaft, which is a rotation limiting load on the winding shaft required for limiting the transmission of the rotation of the motor to the winding shaft, is set as the first limiting load.

  Here, at a predetermined opportunity, the second limiting mechanism limits the operation of the first limiting mechanism, and the rotation of the motor of the first limiting mechanism is transmitted to the winding shaft side, so that the rotation of the motor is transmitted. It is transmitted to the take-up shaft through the mechanism.

  For this reason, the sliding load of the winding shaft can be increased from the first limit load. In addition, since the second limiting mechanism only needs to limit the operation of the first limiting mechanism, the configuration can be simplified.

  In the webbing take-up device according to the second aspect, the second restriction mechanism switches between permitting and restricting the operation of the first restricting mechanism in accordance with the winding amount or the drawing amount of the webbing with respect to the winding shaft. For this reason, the state where the sliding load of the winding shaft is set to the first limit load and the sliding load of the winding shaft is increased from the first limit load corresponding to the winding amount or the drawing amount of the webbing with respect to the winding shaft. The state to be performed can be switched.

  In the webbing take-up device according to the third aspect, the second restriction mechanism restricts the operation of the first restriction mechanism in a state where the webbing is mounted on the occupant. For this reason, the sliding load of the winding shaft can be increased from the first limit load in a state where the webbing is mounted on the occupant.

  In the webbing take-up device according to claim 4, when the rotation restricting load applied to the take-up shaft is equal to or larger than the second restricting load larger than the first restricting load, the second restricting mechanism is operated to By restricting the transmission of the rotation on the motor side of the limiting mechanism to the winding shaft side, the transmission of the rotation of the motor to the winding shaft is limited.

  For this reason, when the second limiting mechanism limits the operation of the first limiting mechanism, the sliding load of the winding shaft can be set to a second limiting load that is larger than the first limiting load.

  In the webbing take-up device according to claim 5, the rotation of the motor in the positive direction is transmitted to the take-up shaft via the transmission mechanism, whereby the take-up shaft is rotated in the take-up direction, and the take-up shaft The webbing is wound up. Further, the rotation of the motor in the reverse direction is transmitted to the take-up shaft via the transmission mechanism, whereby the take-up shaft is rotated in the pull-out direction, and the webbing is drawn from the take-up shaft.

  For this reason, the webbing can be wound and pulled out from the winding shaft by the motor.

It is a front view which shows the principal part of the webbing winding device concerning a 1st embodiment of the present invention. 1 is an exploded perspective view showing a webbing take-up device according to a first embodiment of the present invention. It is a side view which shows the overload release mechanism in the webbing take-up device according to the first embodiment of the present invention. It is a side view which shows the high load mechanism in the webbing winding device concerning a 1st embodiment of the present invention. It is a side view which shows the switching mechanism in the webbing winding device concerning a 1st embodiment of the present invention. It is a front view which shows the principal part of the webbing winding device concerning a 2nd embodiment of the present invention. (A) And (B) is a side view which shows the switching mechanism in the webbing take-up device according to the third embodiment of the present invention, and (A) shows that the sliding load of the take-up shaft is the first limit load (low). It is a figure which shows the time when it was set to (load), (B) is a figure which shows the time when the sliding load of a winding shaft was made into the 2nd limit load (high load). (A) And (B) is a side view which shows the principal part of the switching mechanism in the webbing winding device which concerns on 3rd Embodiment of this invention, (A) is the 1st restriction | limiting in the sliding load of a winding shaft. It is a figure which shows the time of being made into the load (low load), (B) is a figure which shows the time when the sliding load of a winding shaft was made into the 2nd limit load (high load). It is front sectional drawing which shows the principal part of the webbing winding device concerning a 4th embodiment of the present invention. It is a side view which shows the principal part of the webbing winding device concerning a 4th embodiment of the present invention. It is front sectional drawing which shows the principal part of the webbing winding device concerning a 5th embodiment of the present invention. It is a disassembled perspective view which shows the principal part of the webbing winding device concerning a 5th embodiment of the present invention.

[First Embodiment]
FIG. 2 shows an exploded perspective view of the webbing take-up device 10 according to the first embodiment of the present invention.

  As shown in FIG. 2, the webbing take-up device 10 according to this embodiment includes a U-shaped plate-like frame 12 as an arrangement member. The frame 12 is provided with a flat back plate 14. The back plate 14 is fixed to the vehicle body in a lower end portion of a center pillar (not shown) of the vehicle, for example, so that the webbing take-up device 10 is mounted on the vehicle body. Installed on. Flat leg plates 16 and 18 extend from both ends of the back plate 14 in the width direction, and the pair of leg plates 16 and 18 are parallel to each other and are opposed to each other substantially in the vehicle front-rear direction.

  A substantially cylindrical winding shaft 20 (spool) is disposed between the pair of leg plates 16 and 18 so as to be rotatable around the axis, and the axial direction of the winding shaft 20 is opposite to the pair of leg plates 16 and 18. Have been in the direction.

  A base end of a long belt-like webbing 22 is locked to the winding shaft 20. When the winding shaft 20 is rotated in one winding direction (the direction of arrow A in FIG. 2) around the axis, the webbing 22 is wound around the outer periphery of the winding shaft 20 in a layered manner from the base end side. Stored. Further, the webbing 22 is pulled out from the winding shaft 20 by rotating the winding shaft 20 in a pulling direction opposite to the winding direction (arrow B direction in FIG. 2).

  When the webbing 22 is mounted on a vehicle occupant (not shown), the webbing 22 is pulled out from the take-up shaft 20 and is provided on the webbing 22 after the occupant is seated on the vehicle seat (not shown). A tongue (not shown) is locked to a buckle (not shown) connected to a seat or a vehicle body near the seat. Thereby, the webbing 22 is supported at three points on the upper side on the one side in the left-right direction of the seat, the lower side on the other side in the left-right direction of the seat (buckle position) and the lower side on the one side in the left-right direction of the seat, The base end side portion of the webbing 22 from the tongue of the webbing 22 is stretched in an oblique direction to the occupant's chest, and the distal end side portion of the webbing 22 from the tongue of the webbing 22 is suspended from the occupant in the lateral direction. Moreover, by releasing the locking of the tongue to the buckle, the wearing of the webbing 22 to the occupant is released. The tongue is movable with respect to the webbing 22, but when the webbing 22 is attached to the occupant, the front side of the webbing 22 from the position of the webbing 22 that contacts the waist of the occupant (hereinafter referred to as the “tung locking position”) The movement of the tongue to is locked.

  A long bar-like torsion shaft (not shown) is coaxially disposed inside the winding shaft 20. The end of the torsion shaft on the side of the leg plate 16 is connected to the take-up shaft 20 so as to be integrally rotatable, and the portion of the torsion shaft on the side of the leg plate 18 passes through the leg plate 18 and protrudes outside the leg plate 18 of the frame 12. .

  A box-shaped sensor cover 24 is attached to the outside of the leg plate 18 of the frame 12, and the leg plate 18 side of the sensor cover 24 is opened. A torsion shaft is inserted inside the sensor cover 24, and the torsion shaft is rotatably supported by the sensor cover 24. A lock mechanism 26 is housed inside the sensor cover 24. When the lock mechanism 26 detects an emergency state of the vehicle (for example, sudden deceleration), the lock mechanism 26 rotates the torsion shaft in the pull-out direction. Regulate (lock).

  A pretensioner mechanism 28 is provided outside the leg plate 18 of the frame 12. The pretensioner mechanism 28 is provided with a cylinder 30, and the cylinder 30 is fixed to the leg plate 18. The gas generator 32 is accommodated in the proximal end of the cylinder 30. When the detection device 84 described below detects an emergency state of the vehicle (for example, a collision), the pretensioner mechanism 28 is controlled by the control device 82 described below. Is activated, and the gas generator 32 instantaneously generates high-pressure gas in the cylinder 30. As a result, the pretensioner mechanism 28 forcibly rotates the torsion shaft in the winding direction by the gas pressure.

  A box-shaped gear housing 34 constituting a support member is attached to the outside of the leg plate 16 of the frame 12. The gear housing 34 is opened to the side opposite to the leg plate 16, and the opening of the gear housing 34 is closed by a gear cover 36 constituting a support member.

  A hexagonal columnar adapter 38 is disposed inside the gear housing 34. The adapter 38 passes through the gear housing 34 and the leg plate 16 and is coaxially fixed to the torsion shaft, and the adapter 38 can rotate integrally with the torsion shaft and the winding shaft 20. A cylindrical support shaft portion 38A is provided coaxially and integrally on the gear cover 36 side of the adapter 38. The support shaft portion 38A penetrates the gear cover 36 and is opposite to the gear housing 34 of the gear cover 36. It is protruded to.

  On the opposite side of the gear cover 36 from the gear housing 34, a substantially bottomed cylindrical spring cover 40 is provided. The spring cover 40 is attached to the gear housing 34, and the spring cover 40 is opened to the gear cover 36 side. A support shaft portion 38A of the adapter 38 is inserted inside the spring cover 40, and the support shaft portion 38A is rotatably supported by the spring cover 40.

  A mainspring spring (not shown) as an urging means is accommodated inside the spring cover 40. The outer end of the mainspring spring is locked to the spring cover 40, and the inner end of the mainspring spring is locked to the support shaft portion 38A of the adapter 38. The mainspring spring includes the adapter 38, the torsion shaft, and the torsion shaft. The winding shaft 20 is biased in the winding direction, and a biasing force in the winding direction on the winding shaft 20 is applied to the webbing 22.

  A transmission mechanism 42 shown in FIG. 1 is accommodated inside the gear housing 34.

  The transmission mechanism 42 is provided with a bottomed cylindrical spur clutch gear 44. The clutch gear 44 is rotatably supported inside the gear housing 34, and the adapter 38 is inserted coaxially and relatively rotatably inside the clutch gear 44.

  A clutch mechanism 46 is provided inside the clutch gear 44.

  The clutch mechanism 46 is operated by rotating the clutch gear 44 in the winding direction in a state where a centrifugal force of a predetermined level or more is applied to the clutch gear 44. For this reason, when the clutch mechanism 46 connects the clutch gear 44 and the adapter 38, the clutch gear 44 and the adapter 38 can be rotated together. Thereafter, the clutch gear 44 is rotated in the pull-out direction in a state where a centrifugal force less than a predetermined value is applied to the clutch gear 44, whereby the operation of the clutch mechanism 46 is released. For this reason, when the clutch mechanism 46 releases the connection between the clutch gear 44 and the adapter 38, the clutch gear 44 and the adapter 38 can be rotated relative to each other.

  Further, the clutch mechanism 46 is operated by rotating the clutch gear 44 in the pull-out direction in a state in which a predetermined centrifugal force is applied to the clutch gear 44. For this reason, when the clutch mechanism 46 connects the clutch gear 44 and the adapter 38, the clutch gear 44 and the adapter 38 can be rotated together. Thereafter, the clutch gear 44 is rotated in the winding direction in a state where a centrifugal force less than a predetermined value is applied to the clutch gear 44, whereby the operation of the clutch mechanism 46 is released. For this reason, when the clutch mechanism 46 releases the connection between the clutch gear 44 and the adapter 38, the clutch gear 44 and the adapter 38 can be rotated relative to each other.

  The transmission mechanism 42 is provided with a spur output gear 48, and the output gear 48 has an axial direction parallel to the clutch gear 44. The output gear 48 is fixed to the output shaft of the motor 50 so as to be integrally rotatable. The output shaft of the motor 50 is passed through the gear housing 34, and the main body portion of the motor 50 is attached to the outside of the gear housing 34. It has been. When the motor 50 is driven forward, the output shaft and the output gear 48 are rotated in the forward direction, and when driven reversely, the output shaft and the output gear 48 are rotated in the reverse direction. Further, the motor 50 can be driven at a high speed, a low speed, and an ultra-low speed, and the output shaft and the output gear 48 can be rotated at a high speed, a low speed, and an ultra-low speed, respectively.

  The clutch gear 44 and the output gear 48 are connected via an overload release mechanism 52 (torque limiter mechanism, low load mechanism) as a first limiting mechanism shown in FIGS. The clutch gear 44 and the overload release mechanism 52 may be communicated with each other via a predetermined number of transmission gears, and the output gear 48 and the overload release mechanism 52 may be communicated with each other via a predetermined number of transmission gears. May be.

  The overload release mechanism 52 is provided with a bottomed cylindrical spur gear ring 54 as a first rotating body. The gear ring 54 is rotatably supported inside the gear housing 34, and the gear ring 54 has an axial direction parallel to the output gear 48 and is connected (engaged) with the output gear 48. A projecting portion 54 </ b> A having a substantially trapezoidal cross section as a restricting portion is integrally provided on the inner peripheral surface of the gear ring 54, and the projecting portion 54 </ b> A projects radially inward of the gear ring 54.

  The overload release mechanism 52 is provided with a rotor 56 as an operating rotating body. The rotor 56 is rotatably supported inside the gear housing 34, and the rotor 56 passes through the gear ring 54 and is disposed coaxially with the gear ring 54.

  A spur gear 58 is coaxially provided in the rotor 56, and the gear 58 is disposed outside the gear ring 54 and is connected (engaged) to the clutch gear 44. The rotor 56 is provided with a cylindrical base 60 as a sliding portion coaxially inside the gear ring 54, and the base 60 can rotate integrally with the gear portion 58.

  A predetermined number (two in the present embodiment) of friction springs 62 as first limiting means is provided between the gear ring 54 and the base 60, and the friction springs 62 are spirally rotated a predetermined number of times (this embodiment). In this case, it is a torsion coil spring wound twice. One end 62A (one longitudinal end) and the other end 62B (the other longitudinal end) of the friction spring 62 are spaced apart from each other in the circumferential direction of the friction spring 62 and protrude outward in the radial direction of the friction spring 62. A protrusion 54A of the gear ring 54 is disposed between one end 62A and the other end 62B of the friction spring 62. For this reason, the relative rotation of the friction spring 62 with respect to the gear ring 54 is restricted by the contact of the one end 62A and the other end 62B of the friction spring 62 with the protrusion 54A.

  The friction spring 62 is mounted on the outer peripheral surface of the base 60 in a state in which the diameter is increased against the urging force, and the friction spring 62 generates a frictional force due to the urging force between the friction spring 62 and the outer peripheral surface of the base 60. Thus, relative rotation with the rotor 56 is limited.

  Thus, when the motor 50 is positively driven at a high speed or a low speed, the gear ring 54 and the rotor 56 are rotated in the forward direction (the direction of arrow C in FIG. 3), and the clutch gear 44 is rotated in the winding direction. The clutch mechanism 46 is operated. For this reason, the adapter 38, the torsion shaft and the winding shaft 20 can be rotated in the winding direction integrally with the clutch gear 44, and the forward rotation of the motor 50 is decelerated by the transmission mechanism 42 and transmitted to the winding shaft 20. The Thereafter, when the motor 50 is reversely driven at an ultra-low speed, the gear ring 54 and the rotor 56 are rotated in the reverse direction (in the direction of arrow D in FIG. 3), and the clutch gear 44 is rotated in the pull-out direction. Is released. For this reason, the adapter 38, the torsion shaft and the take-up shaft 20 are rotatable relative to the clutch gear 44.

  On the other hand, when the motor 50 is reversely driven at a high speed or a low speed, the gear ring 54 and the rotor 56 are rotated in the reverse direction (the direction of arrow D in FIG. 3), and the clutch gear 44 is rotated in the pull-out direction. 46 is activated. For this reason, the adapter 38, the torsion shaft and the take-up shaft 20 can be rotated in the pull-out direction integrally with the clutch gear 44, and the reverse rotation of the motor 50 is decelerated by the transmission mechanism 42 and transmitted to the take-up shaft 20. . Thereafter, when the motor 50 is positively driven at an ultra-low speed, the gear ring 54 and the rotor 56 are rotated in the forward direction (in the direction of arrow C in FIG. 3), and the clutch gear 44 is rotated in the take-up direction. The operation of 46 is released. For this reason, the adapter 38, the torsion shaft and the take-up shaft 20 are rotatable relative to the clutch gear 44.

  Further, when the relative rotational force between the rotor 56 and the gear ring 54 is larger than the frictional force (maximum static frictional force) between the predetermined number of friction springs 62 and the outer peripheral surface of the base 60, overloading occurs. The release mechanism 52 is actuated so that the outer peripheral surface of the base 60 and the predetermined number of friction springs 62 slide against the frictional force, whereby the base 60 and the predetermined number of friction springs 62 are relatively rotated. The relative rotation between the rotor 56 and the gear ring 54 is allowed.

  A high load mechanism 64 (overload release mechanism, torque limiter mechanism) as a second limiting mechanism shown in FIGS. 1 and 4 is provided on the side of the overload release mechanism 52.

  The high load mechanism 64 is provided with a bottomed cylindrical spur ring holder 66 as a second rotating body. The ring holder 66 is rotatably supported inside the gear housing 34, and the ring holder 66 is disposed coaxially with the gear ring 54 of the overload release mechanism 52 and has the same outer diameter as the gear ring 54. ing.

  The rotor 56 of the overload release mechanism 52 is inserted inside the ring holder 66, and the rotor 56 is arranged coaxially with the ring holder 66. The rotor 56 is provided with an engaging body 68 coaxially inside the ring holder 66, and the engaging body 68 is integrally rotatable with the gear portion 58 and the base 60. Engagement teeth 68A having a substantially triangular cross section are formed on the entire outer periphery of the engagement body 68, and the engagement teeth 68A are curved in a concave shape.

  A ring 70 as a second restricting means is provided inside the ring holder 66, and the ring 70 is arranged coaxially with the ring holder 66. The ring 70 is provided with an annular plate-shaped base portion 70 </ b> A, and the base portion 70 </ b> A is disposed on the bottom surface of the ring holder 66. A predetermined number (four in this embodiment) of rectangular plate-like connecting portions 70B are integrally provided on the base portion 70A, and the connecting portions 70B extend radially outward from the base portion 70A. A biasing portion 70C having a substantially J-shaped cross section is integrally provided at the distal end of the connecting portion 70B. (The arrow C side in FIGS. 3 and 4). The connecting portion 70B and the base end side portion of the urging portion 70C in the ring 70 are engaged with the bottom wall and the peripheral wall of the ring holder 66, respectively, and relative rotation of the ring 70 with respect to the ring holder 66 is restricted. .

  The urging portion 70C has a distal end portion disposed radially inward of the ring 70 with respect to the proximal end portion, and a rectangular plate-like engagement portion 70D is integrally provided at the distal end of the urging portion 70C. It has been. The engaging portion 70D extends radially inward of the ring 70, and the engaging portion 70D is engaged (pressed against) between the engaging teeth 68A of the engaging body 68 of the rotor 56 by the urging force of the urging portion 70C. The relative rotation between the rotor 56 and the ring 70 is limited.

  Further, when the relative rotational force between the rotor 56 and the ring holder 66 is made larger than the engaging force between the predetermined number of engaging portions 70D of the ring 70 and the engaging teeth 68A of the engaging body 68 of the rotor 56. When the high load mechanism 64 is operated and the predetermined number of engaging portions 70D get over the engaging teeth 68A against the urging force of the predetermined number of urging portions 70C, the engaging body 68, the ring 70, Are relatively rotated, and relative rotation between the rotor 56 and the ring holder 66 is allowed. The relative rotational force between the rotor 56 and the ring holder 66 when the high load mechanism 64 is operated is compared with the relative rotational force between the rotor 56 and the gear ring 54 when the overload release mechanism 52 is operated. And it has been enlarged.

  A switching mechanism 72 shown in FIGS. 1 and 5 is provided on the side of the overload release mechanism 52 and the high load mechanism 64.

  The switching mechanism 72 is provided with a spur gear 74 as a communication means, and the communication gear 74 is disposed radially outside the gear ring 54 of the overload release mechanism 52 and the ring holder 66 of the high load mechanism 64. In addition, the axial direction is parallel to the gear ring 54 and the ring holder 66.

  A long support groove 76 is formed in the gear housing 34 and the gear cover 36, and the support groove 76 is bent at an intermediate portion in the longitudinal direction. One side portion 76A (the portion on the gear ring 54 and ring holder 66 side) of the support groove 76 is disposed substantially parallel to the circumferential direction of the gear ring 54 and the ring holder 66, and the other side portion 76B (gear ring 54) of the support groove 76. And the portion on the opposite side of the ring holder 66) is inclined in a direction toward the radially outer side of the gear ring 54 and the ring holder 66 as the distance from the one side portion 76A increases.

  Center shafts 74A at both axial ends of the connection gear 74 are rotatably inserted into the support grooves 76 of the gear housing 34 and the gear cover 36, respectively. The connection gear 74 is stretched between the gear housing 34 and the gear cover 36. The gear housing 34 is rotatably supported inside.

  A tension coil spring 78 as a release means is suspended between the central shaft 74A of the communication gear 74 and the peripheral wall of the gear housing 34. The central shaft 74A of the communication gear 74 is moved by the urging force of the tension coil spring 78. The communication gear 74 is disposed on the other side portion 76 </ b> B of the support groove 76 and is separated from the gear ring 54 and the ring holder 66.

  A solenoid 80 serving as switching means is provided on the side of the communication gear 74, and the solenoid 80 is fixed inside the gear housing 34.

  When the switching mechanism 72 is actuated and the solenoid 80 is actuated, the plunger of the solenoid 80 presses the central shaft 74A of the communication gear 74 and resists the urging force of the tension coil spring 78, so By moving to the side portion 76A, the communication gear 74 is connected (engaged) with the gear ring 54 and the ring holder 66, and the gear ring 54 and the ring holder 66 are integrally rotatable by the communication gear 74. In the support groove 76, the one side portion 76 </ b> A is bent with respect to the other side portion 76 </ b> B, so that the central shaft 74 </ b> A of the connection gear 74 is effectively held by the one side portion 76 </ b> A of the support groove 76 by the operation of the solenoid 80. Thus, the communication of the communication gear 74 to the gear ring 54 and the ring holder 66 is effectively maintained.

  On the other hand, when the operation of the switching mechanism 72 is released and the operation of the solenoid 80 is released, the plunger of the solenoid 80 releases the pressing of the central shaft 74 </ b> A of the communication gear 74 and the urging force of the tension coil spring 78. As a result, the center shaft 74A of the connection gear 74 is moved to the other side portion 76B of the support groove 76, so that the connection of the connection gear 74 to the gear ring 54 and the ring holder 66 is released. Relative rotation is enabled.

  The buckle, pretensioner mechanism 28 (gas generator 32), motor 50 and solenoid 80 are electrically connected to a vehicle control device 82. A vehicle detection device 84 is electrically connected to the control device 82. The detection device 84 can detect the seating of an occupant on a seat and can predict and detect an emergency state of the vehicle. In addition, it is possible to detect that the emergency state of the vehicle has been avoided after predicting the emergency state of the vehicle.

  When the detection device 84 detects the seating of an occupant on the seat, the motor 50 is reversely driven at a low speed under the control of the control device 82. Thereafter, when the tongue is locked to the buckle, the reverse drive of the motor 50 is stopped and the solenoid 80 is operated under the control of the control device 82. When the locking of the tongue to the buckle is released, the motor 50 is positively driven at a low speed and the operation of the solenoid 80 is released under the control of the control device 82.

  When the detection device 84 predicts an emergency state of the vehicle, the motor 50 is positively driven at a high speed under the control of the control device 82. Thereafter, when the detection device 84 detects that the emergency state of the vehicle has been avoided, the positive drive of the motor 50 is stopped under the control of the control device 82. Further, when the detection device 84 detects an emergency state of the vehicle, the pretensioner mechanism 28 is operated under the control of the control device 82.

  When the motor 50 is being driven and the driving of the motor 50 is restricted and a lock current is generated in the motor 50 (particularly when the winding of the webbing 22 around the take-up shaft 20 is restricted. When the webbing 22 is wound on the take-up shaft 20 by the limit length (total amount)), the drive of the motor 50 is stopped under the control of the control device 82.

  When the driving of the motor 50 is stopped after the motor 50 is driven at a high speed or a low speed and the clutch mechanism 46 is operated, the motor 50 is controlled at a very low speed by the control of the control device 82 in a direction opposite to that before. The operation of the clutch mechanism 46 is released by being driven for a time.

  Next, the operation of this embodiment will be described.

  In the webbing retractor 10 having the above configuration, when the detection device 84 detects the seating of an occupant on the seat, the motor 50 is reversely driven at a low speed by the control of the control device 82 and the output gear 48 rotates in the reverse direction. As a result, the gear ring 54 and the rotor 56 of the overload release mechanism 52 are rotated in the reverse direction, and the clutch gear 44 is rotated in the pull-out direction. The operation of the clutch mechanism 46 causes the adapter 38 to be integrated with the clutch gear 44. The torsion shaft and the winding shaft 20 are rotated with a low load (low torque) in the drawing direction. For this reason, when the webbing 22 is pulled out from the winding shaft 20 with a low load, the tongue is locked to the buckle by the occupant and the webbing 22 is attached to the occupant.

  When the tongue is locked to the buckle, the reverse drive of the motor 50 is stopped by the control of the control device 82, and then the motor 50 is positively driven at a very low speed for a predetermined time and the operation of the clutch mechanism 46 is released. Is done. For this reason, the webbing 22 is wound around the winding shaft 20 by the biasing force of the mainspring spring, and slack (slack) of the webbing 22 is removed.

  As described above, when the webbing 22 is mounted on the occupant, the mainspring spring acts on the winding shaft 20 from the winding shaft 20 by the driving force of the motor 50 against the urging force in the winding direction. The webbing 22 is pulled out. For this reason, since the drawing of the webbing 22 from the winding shaft 20 is assisted (assisted), the occupant can easily attach the webbing 22.

  On the other hand, when the mounting of the webbing 22 to the occupant is released, the locking of the tongue to the buckle is released by the occupant. When the locking of the tongue to the buckle is released, the motor 50 is positively driven at a low speed by the control of the control device 82 and the output gear 48 is rotated in the positive direction, so that the gearing of the overload release mechanism 52 is performed. 54 and the rotor 56 are rotated in the forward direction, the clutch gear 44 is rotated in the winding direction, and the operation of the clutch mechanism 46 causes the adapter 38, the torsion shaft, and the winding shaft 20 to be wound together with the clutch gear 44. It is rotated with a low load (low torque) in the direction. For this reason, the webbing 22 is wound and stored on the winding shaft 20 with a low load.

  When the webbing 22 is wound on the winding shaft 20 by the limit length, the winding of the webbing 22 onto the winding shaft 20 is restricted, and the driving of the motor 50 is restricted, so that the motor 50 is locked. A current is generated, and the positive drive of the motor 50 is stopped under the control of the control device 82. Thereafter, the motor 50 is reversely driven at a very low speed for a predetermined time under the control of the control device 82, and the operation of the clutch mechanism 46 is released.

  As described above, when the installation of the webbing 22 to the occupant is released, not only the biasing force in the winding direction that the mainspring spring acts on the winding shaft 20 but also the driving force of the motor 50 causes the winding. The webbing 22 is wound around the take-up shaft 20. For this reason, the winding of the webbing 22 onto the winding shaft 20 can be effectively assisted (assisted). In addition, the biasing force in the winding direction that the mainspring spring acts on the winding shaft 20 can be reduced, and when the webbing 22 is attached to the occupant, the occupant feels a sense of pressure from the webbing 22 by the urging force of the mainspring spring. This can be effectively suppressed.

  When the tongue is not locked to the buckle and the webbing 22 is not attached to the occupant, the solenoid 80 is not operated in the switching mechanism 72. For this reason, the central shaft 74A of the connection gear 74 is disposed on the other side portion 76B of the support groove 76 by the urging force of the tension coil spring 78, and the connection gear 74 is connected to the gear ring 54 of the overload release mechanism 52 and the high load mechanism 64. By being separated from the ring holder 66, the gear ring 54 can be rotated relative to the ring holder 66, and the ring holder 66 and the ring 70 of the high load mechanism 64 can always rotate integrally with the rotor 56 (idle). Has been.

  As described above, after the locking of the tongue to the buckle is released, the motor 50 is positively driven at a low speed, whereby the winding shaft 20 is rotated in the winding direction with a low load, and the winding shaft 20 is rotated. When the webbing 22 is wound at a low load, for example, when the webbing 22 is caught on the occupant's arm and a rotation limit load greater than or equal to the first limit load is applied to the winding shaft 20 in the pull-out direction, overloading occurs. In the release mechanism 52, the relative rotational force between the rotor 56 and the gear ring 54 is made larger than the friction force between the predetermined number of friction springs 62 and the outer peripheral surface of the base 60 of the rotor 56.

  For this reason, the overload release mechanism 52 is operated, and the outer peripheral surface of the base 60 and the predetermined number of friction springs 62 are slid against the frictional force, whereby the base 60 and the predetermined number of friction springs 62 are Are relatively rotated, and relative rotation between the rotor 56 and the gear ring 54 is allowed.

  As a result, the rotation of the rotor 56 in the forward direction by the positive drive of the motor 50 and the rotation of the clutch gear 44, the adapter 38, the torsion shaft and the winding shaft 20 in the winding direction are restricted, and the winding shaft 20 is moved. By restricting the winding of the webbing 22, it is possible to effectively suppress the passenger from feeling uncomfortable from the webbing 22.

  When the tongue is locked to the buckle and the webbing 22 is attached to the occupant and the lock mechanism 26 detects an emergency state of the vehicle, the lock mechanism 26 restricts the rotation of the torsion shaft in the pull-out direction. As a result, the rotation of the take-up shaft 20 in the pull-out direction is restricted, and the withdrawal of the webbing 22 from the take-up shaft 20 is restricted. For this reason, the passenger is restrained by the webbing 22. Further, when the detection device 84 detects an emergency state of the vehicle, the pretensioner mechanism 28 is operated by the control of the control device 82, and the pretensioner mechanism 28 is forced to wind the torsion shaft in the winding direction by the gas pressure. , The winding shaft 20 is rotated in the winding direction with a high load (high torque), and the webbing 22 is wound around the winding shaft 20 with a high load. For this reason, the restraining force of the occupant by the webbing 22 is increased.

  Further, when the tongue is locked to the buckle and the webbing 22 is attached to the occupant, the solenoid 80 is operated in the switching mechanism 72 under the control of the control device 82. For this reason, the plunger of the solenoid 80 presses the central shaft 74A of the connection gear 74 and moves it to the one side portion 76A of the support groove 76 against the urging force of the tension coil spring 78, so that the connection gear 74 is overloaded. The gear ring 54 and the ring holder 66 are connected to the gear ring 54 of the release mechanism 52 and the ring holder 66 of the high load mechanism 64, and the gear ring 54 and the ring holder 66 are integrally rotatable by the rotation of the communication gear 74 and the ring holder 66 due to the rotation of the gear ring 54.

  When the detection device 84 predicts the emergency state of the vehicle before detecting the emergency state of the vehicle, the motor 50 is positively driven at a high speed by the control of the control device 82 and the output gear 48 is rotated in the positive direction. Thus, the gear ring 54, the ring holder 66, and the rotor 56 are rotated in the forward direction, and the clutch gear 44 is rotated in the winding direction. By the operation of the clutch mechanism 46, the adapter 38, the torsion shaft, and the The winding shaft 20 is rotated with a high load (high torque) in the winding direction. For this reason, since the webbing 22 is wound around the winding shaft 20 with a high load, the occupant can be effectively restrained by the webbing 22 before the emergency state of the vehicle.

  Thereafter, when the detection device 84 detects that the emergency state of the vehicle has been avoided, the motor 50 is reversely driven at a very low speed for a predetermined time after the forward drive of the motor 50 is stopped under the control of the control device 82. Thus, the operation of the clutch mechanism 46 is released.

  As described above, when the motor 50 is positively driven at a high speed, the winding shaft 20 is rotated with a high load in the winding direction, and the webbing 22 is wound on the winding shaft 20 with a high load. When a rotational limit load greater than the second limit load greater than the first limit load is applied to the take-up shaft 20 via the webbing 22 by the occupant's moving force in the pull-out direction, the rotor 56 The relative rotational force between the gear ring 54 and the gear ring 54 is made larger than the friction force between the predetermined number of friction springs 62 and the outer peripheral surface of the base 60 of the rotor 56, and in the high load mechanism 64, the rotor 56 and the ring holder 66. Is made larger than the engagement force between a predetermined number of engagement portions 70D of the ring 70 and the engagement teeth 68A of the engagement body 68 of the rotor 56.

  For this reason, the overload release mechanism 52 is operated, and the outer peripheral surface of the base 60 and the predetermined number of friction springs 62 are slid against the frictional force, whereby the base 60 and the predetermined number of friction springs 62 are Are rotated relative to each other to allow relative rotation between the rotor 56 and the gear ring 54, and the high load mechanism 64 is operated so that a predetermined number of engaging portions 70D of the ring 70 are attached to a predetermined number of biasing portions 70C. By overcoming the engaging teeth 68A against the force, the engaging body 68 and the ring 70 are relatively rotated, and the relative rotation between the rotor 56 and the ring holder 66 is allowed.

  As a result, the rotation of the rotor 56 in the positive direction by the positive drive of the motor 50 and the rotation of the clutch gear 44, the adapter 38, the torsion shaft and the winding shaft 20 in the winding direction are restricted, and the winding shaft 20 By restricting the rotation limit load that is greater than or equal to the second limit load acting in the pull-out direction from being transmitted to the motor 50, an excessive load acts on the motor 50 and the mechanism that transmits rotation to the motor 50. It can be effectively suppressed.

  Here, as described above, when the tongue is locked to the buckle and the webbing 22 is attached to the occupant (predetermined opportunity), the communication gear 74 of the switching mechanism 72 is engaged with the gear ring 54 of the overload release mechanism 52. In addition, the gear ring 54 and the ring holder 66 are integrally rotated by the communication gear 74 in communication with the ring holder 66 of the high load mechanism 64.

  For this reason, when the detection device 84 predicts the emergency state of the vehicle and the motor 50 is positively driven at a high speed, even when a rotation limit load greater than the first limit load is applied to the winding shaft 20, the high load The mechanism 64 restricts the operation of the overload release mechanism 52, and the rotation of the motor 50 is transmitted to the winding shaft 20 via the overload release mechanism 52, the communication gear 74, and the high load mechanism 64. The sliding load of the take-up shaft 20 that is a rotation limit load to the take-up shaft 20 necessary for limiting the transmission of the rotation to the take-up shaft 20 can be increased from the first limit load. As a result, the take-up shaft 20 can be rotated with a high load in the take-up direction, and the webbing 22 can be taken up with a high load on the take-up shaft 20. Can be restrained.

  Moreover, in order to increase the sliding load of the winding shaft 20 from the first limit load, the high load mechanism 64 may limit the operation of the overload release mechanism 52. For this reason, it is not necessary to provide a mechanism for transmitting the rotation of the motor 50 to the take-up shaft 20 independently of the overload release mechanism 52, and the configuration can be simplified.

  In addition, when the detection device 84 predicts an emergency state of the vehicle and the motor 50 is positively driven at a high speed, a rotation limit load greater than or equal to the second limit load is applied to the winding shaft 20 in the pull-out direction. The overload release mechanism 52 and the high load mechanism 64 are operated, and the transmission of the rotation of the motor 50 to the winding shaft 20 is limited by the overload release mechanism 52 and the high load mechanism 64. For this reason, the sliding load of the winding shaft 20 can be set to the second limit load, and it is possible to effectively suppress the excessive load from acting on the motor 50 and the mechanism that transmits the rotation to the motor 50.

[Second Embodiment]
The principal part of the webbing retractor 100 according to the second embodiment of the present invention is shown in a front view in FIG.

  The webbing take-up device 100 according to this embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  As shown in FIG. 6, in the webbing take-up device 100 according to the present embodiment, in the overload release mechanism 52, the first connection that constitutes the connection means on the entire end of the gear ring 54 on the high load mechanism 64 side. Teeth 54B are formed.

  In the high load mechanism 64, the second connection teeth 66A constituting the connection means are formed at the end of the ring holder 66 on the overload release mechanism 52 side, and the ring holder 66 and the ring 70 are gear rings. It is possible to move (slide) to the 54 side.

  In the switching mechanism 72, the communication gear 74, the support groove 76, and the tension coil spring 78 in the first embodiment are not provided.

  A coil spring 102 as a release means is suspended between the communication gear 74 (which may be the base 60 of the rotor 56) and the ring holder 66 (which may be the ring 70). 56 is inserted, and the communication gear 74 and the ring holder 66 are separated from each other.

  On the opposite side of the ring holder 66 from the gear ring 54, a bottomed cylindrical moving body 104 that constitutes a communication means is provided, and the moving body 104 is disposed coaxially with the gear ring 54 and the ring holder 66. Yes. The moving body 104 is supported inside the gear housing 34 so as to be movable (slidable) toward the ring holder 66.

  The solenoid 80 of the switching mechanism 72 is fixed to the inside of the gear housing 34 on the side opposite to the ring holder 66 of the moving body 104.

  When the switching mechanism 72 is operated and the solenoid 80 is operated, the plunger of the solenoid 80 presses the moving body 104, and the moving body 104 is moved to the ring holder 66 side and presses the ring holder 66. As a result, the ring holder 66 is moved toward the gear ring 54 against the urging force of the coil spring 102. As a result, the second connecting teeth 66A of the ring holder 66 are connected (engaged) with the first connecting teeth 54B of the gear ring 54, so that the gear ring 54 and the ring holder 66 can rotate together.

  On the other hand, when the operation of the switching mechanism 72 is released and the operation of the solenoid 80 is released, the plunger of the solenoid 80 releases the pressing of the moving body 104, and the moving body 104 and the urging force of the coil spring 102 are released. When the ring holder 66 is moved to the solenoid 80 side, the contact of the ring holder 66 (second connection tooth 66A) with the gear ring 54 (first connection tooth 54B) is released, and the gear ring 54 is connected to the ring holder 66. Relative rotation is enabled.

  Here, also in this embodiment, the same operation and effect as the first embodiment can be obtained.

[Third Embodiment]
FIGS. 7A and 7B show a side view of the switching mechanism 72 in the webbing retractor 150 according to the third embodiment of the present invention.

  The webbing take-up device 150 according to the present embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  As shown in FIGS. 7A and 7B, in the webbing take-up device 150 according to this embodiment, the switching mechanism 72 is not provided with the support groove 76 and the solenoid 80 in the first embodiment.

  The communication gear 74 is rotatably supported at one end of a long plate-like lever 152 as a switching member in each central shaft 74A. The lever 152 is rotatably supported inside the gear housing 34 at an intermediate portion in the longitudinal direction, and the rotation axis direction of the lever 152 is parallel to the axial direction of the connecting gear 74. The connecting gear 74 is separated from the gear ring 54 of the overload release mechanism 52 and the ring holder 66 of the high load mechanism 64 by the urging force of the tension coil spring 78 (see FIGS. 7A and 8A). .

  A spur cam gear 154 is provided on the side of the communication gear 74. The cam gear 154 is rotatably supported inside the gear housing 34 and has an axial direction parallel to the communication gear 74. . The cam gear 154 is connected to the take-up shaft 20 via a predetermined number of reduction gears 156, and the rotation of the take-up shaft 20 is always transmitted to the cam gear 154 after being reduced through the predetermined number of reduction gears 156. . Note that the axial position of the cam gear 154 is shifted from the axial position of the communication gear 74, and the communication gear 74 cannot be connected (engaged) with the cam gear 154.

  On the side surface of the cam gear 154, a substantially disk-shaped cam 158 as a switching means is provided coaxially, and the cam 158 can rotate integrally with the cam gear 154. When the winding shaft 20 is rotated in the winding direction, the cam 158 is rotated in the forward direction (the direction of arrow E in FIGS. 7A and 7B) and the winding shaft 20 is pulled out. Is rotated in the reverse direction (the direction of arrow F in FIGS. 7A and 7B).

  A concave portion 160 is provided in the outer peripheral portion of the cam 158, and the concave portion 160 is opened radially outward from the outer peripheral surface of the cam 158, and the other end of the lever 152 is inserted (FIG. 7A). reference). A convex portion 162 is provided on the outer peripheral portion of the cam 158, and the convex portion 162 is adjacent to the opposite side of the concave portion 160 and protrudes radially outward from the outer peripheral surface of the cam 158.

  When the cam 158 is rotated in the reverse direction, the other end of the lever 152 is pressed in the reverse direction by the concave portion 160 of the cam 158, and the lever 152 is rotated against the urging force of the tension coil spring 78. After that, the lever 152 is rotated by the urging force of the tension coil spring 78 (see FIGS. 7B and 8B). For this reason, the switching mechanism 72 is operated, and the connecting gear 74 is connected to the gear ring 54 and the ring holder 66 in a state where the other end of the lever 152 is disposed outside the recess 160 of the cam 158 by the biasing force of the tension coil spring 78. By being connected (engaged), the gear ring 54 and the ring holder 66 can be integrally rotated by the communication gear 74.

  Thereafter, when the cam 158 is rotated in the forward direction, the other end of the lever 152 is pressed in the forward direction by the convex portion 162 of the cam 158, and the lever 152 resists the biasing force of the tension coil spring 78. After the rotation, the lever 152 is rotated by the urging force of the tension coil spring 78 (see FIGS. 7A and 8A). Therefore, the operation of the switching mechanism 72 is released, and the gear ring 54 and the ring holder 66 of the connecting gear 74 are in a state where the other end of the lever 152 is inserted into the recess 160 of the cam 158 by the biasing force of the tension coil spring 78. By releasing the connection to the gear ring 54, the gear ring 54 can be rotated relative to the ring holder 66.

  When the switching mechanism 72 is operated and when the switching mechanism 72 is released, the intermediate state between the state in which the webbing 22 is wound on the winding shaft 20 by the limit length and the state in which the tongue is locked to the buckle. Is when the webbing 22 is pulled out (or the winding amount) with respect to the winding shaft 20 at a predetermined amount. For example, the webbing 22 is pulled out from the state where the webbing 22 is wound up to the winding shaft 20 by a limit length. At the same time, when the webbing 22 is taken up by the take-up shaft 20 after the locking of the tongue to the buckle is released, the tongue locked at the tongue locking position of the webbing 22 passes through the chest of the occupant. It has been in time.

  Here, also in this embodiment, the same operation and effect as the first embodiment can be obtained.

  In particular, when the amount of webbing 22 drawn from the take-up shaft 20 is less than a predetermined amount, the switching mechanism 72 is not operated, and the connecting gear 74 is connected to the gear ring 54 of the overload release mechanism 52 and the high load mechanism 64. The gear ring 54 can be rotated relative to the ring holder 66 by being separated from the ring holder 66.

  After the locking of the tongue to the buckle is released, the motor 50 is positively driven at a low speed, so that the winding shaft 20 is rotated with a low load in the winding direction, and the webbing 22 is low on the winding shaft 20. When the webbing 22 is pulled out from the take-up shaft 20 when it is wound by the load, the webbing 22 is hooked on the occupant's arm, for example, and the take-up shaft 20 is over the first limit load. When the rotation limiting load is applied in the pull-out direction, the overload release mechanism 52 is activated. Thereby, winding of the webbing 22 to the winding shaft 20 is restricted, and the amount of the webbing 22 pulled out from the winding shaft 20 in which the occupant easily feels uncomfortable from the webbing 22 is less than a predetermined amount. In the state, it is possible to effectively suppress the passenger from feeling uncomfortable from the webbing 22.

  On the other hand, when the drawing amount of the webbing 22 from the take-up shaft 20 is equal to or greater than a predetermined amount, the switching mechanism 72 is operated and the communication gear 74 is connected to the gear ring 54 of the overload release mechanism 52 and the ring of the high load mechanism 64. By communicating with the holder 66, the gear ring 54 and the ring holder 66 can be integrally rotated by the rotation of the communication gear 74 and the ring holder 66 due to the rotation of the gear ring 54.

  After the locking of the tongue to the buckle is released, the motor 50 is positively driven at a low speed, so that the winding shaft 20 is rotated with a low load in the winding direction, and the webbing 22 is low on the winding shaft 20. When the webbing 22 is withdrawn from the take-up shaft 20 when the webbing 22 is taken up by a load, for example, the webbing 22 is hooked on the arm of the occupant, and the take-up shaft 20 exceeds the first limit load. Even when the rotation limit load is applied in the pull-out direction, the high load mechanism 64 limits the operation of the overload release mechanism 52, and the sliding load of the winding shaft 20 becomes the second limit load. As a result, the webbing 22 is normally wound around the winding shaft 20 with a low load, but the uncomfortable feeling that the occupant feels from the webbing 22 is a state where the amount of the webbing 22 pulled out from the winding shaft 20 is less than a predetermined amount. Therefore, the occupant can be prevented from feeling uncomfortable from the webbing 22.

  Moreover, as described above, when the motor 50 is positively driven at a low speed and the webbing 22 is wound around the winding shaft 20 with a low load, the amount of the webbing 22 drawn from the winding shaft 20 is a predetermined amount or more. In this state, when the winding of the webbing 22 around the winding shaft 20 is restricted and a lock current is generated in the motor 50, the positive drive of the motor 50 is stopped by the control of the control device 82, and the motor 50 The winding of the webbing 22 onto the winding shaft 20 by the driving force is stopped. Thereby, it can suppress that a passenger | crew feels uncomfortable from webbing 22. FIG.

  Further, the switching mechanism 72 is not provided with the solenoid 80. For this reason, cost can be reduced.

[Fourth Embodiment]
FIG. 9 shows a front sectional view of the main part of the webbing take-up device 200 according to the fourth embodiment of the present invention, and FIG. 10 shows the main part of the webbing take-up device 200 in a side view. Is shown.

  The webbing take-up device 200 according to this embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  As shown in FIGS. 9 and 10, in the webbing take-up device 200 according to the present embodiment, in the overload release mechanism 52, restriction teeth 54 </ b> C are formed on the entire inner periphery of the gear ring 54.

  The rotor 56 is not provided with the engaging body 68 in the first embodiment. A circular insertion hole 60A is coaxially formed in the base 60 of the rotor 56, and the insertion hole 60A is opened to the high load mechanism 64 side.

  The high load mechanism 64 is a restriction mechanism different from that of the first embodiment.

  The high load mechanism 64 is provided with a predetermined number (two in this embodiment) of long, substantially rectangular plate-like pawls 202 as communication means, and the base ends of the pawls 202 rotate around the base 60 of the rotor 56. It is supported movably. The pawl 202 is rotated by an urging force radially inward of the gear ring 54, and the pawl 202 is separated from the restriction tooth 54 </ b> C of the gear ring 54, so that the rotor 56 can rotate relative to the gear ring 54. Yes.

  The switching mechanism 72 is not provided with the communication gear 74, the support groove 76, and the tension coil spring 78 in the first embodiment.

  The solenoid 80 of the switching mechanism 72 is fixed to the inside of the gear housing 34 on the side opposite to the pawl 202 of the rotor 56 (base 60). A substantially cylindrical enlarged diameter portion 80B as a moving means is formed at the tip of the plunger 80A of the solenoid 80, and the enlarged diameter portion 80B is inserted into the insertion hole 60A of the base 60. The diameter-expanded portion 80B has a larger diameter than the other portions of the plunger 80A, and the base end portion of the diameter-expanded portion 80B has a substantially truncated cone shape with a diameter increasing toward the distal end side of the plunger 80A. Has been increased.

  When the switching mechanism 72 is actuated and the solenoid 80 is actuated, the plunger 80A of the solenoid 80 is attracted against the urging force (release means) (the enlarged diameter portion 80B of the plunger 80A becomes the rotor 56 (base 60) is removed from the insertion hole 60A), and the enlarged diameter portion 80B rotates the pawl 202 to the outer side in the radial direction of the gear ring 54 against the urging force, so that the tip of the pawl 202 becomes the regulating tooth 54C of the gear ring 54. Is contacted (meshed). As a result, the pawl 202 allows the gear ring 54 and the rotor 56 to rotate integrally by rotating the gear ring 54 in the forward direction and rotating the rotor 56 in the reverse direction.

  On the other hand, when the operation of the switching mechanism 72 is released and the operation of the solenoid 80 is released, the plunger 80A of the solenoid 80 is extended by the urging force (release means) (the enlarged diameter portion 80B of the plunger 80A is expanded). When inserted into the insertion hole 60A of the base 60), the pawl 202 is rotated inward in the radial direction of the gear ring 54 by the urging force, so that the communication with the gear ring 54 (regulating tooth 54C) at the tip of the pawl 202 is released. . Thereby, relative rotation with respect to the gear ring 54 of the rotor 56 is enabled.

  Here, when the tongue is not locked to the buckle and the webbing 22 is not attached to the occupant, the solenoid 80 is not operated in the switching mechanism 72. For this reason, when the pawl 202 of the high load mechanism 64 is rotated radially inward of the gear ring 54 of the overload release mechanism 52 by the biasing force, the tip of the pawl 202 is separated from the restriction tooth 54C of the gear ring 54, The rotor 56 is rotatable relative to the gear ring 54, and the pawl 202 is always rotatable integrally with the rotor 56 (idle).

  Further, when the tongue is locked to the buckle and the webbing 22 is attached to the occupant, the solenoid 80 is operated in the switching mechanism 72 under the control of the control device 82. Therefore, the plunger 80A of the solenoid 80 is attracted against the urging force, and the enlarged diameter portion 80B of the plunger 80A rotates the pawl 202 against the urging force outward in the radial direction of the gear ring 54. The front end of 202 is connected to the restriction tooth 54 </ b> C of the gear ring 54, and the gear ring 54 and the rotor 56 can be rotated integrally by the pawl 202 by the forward rotation of the gear ring 54 and the reverse rotation of the rotor 56.

  When the detection device 84 predicts the emergency state of the vehicle before detecting the emergency state of the vehicle, the motor 50 is positively driven at a high speed by the control of the control device 82 and the output gear 48 is rotated in the positive direction. Thus, the gear ring 54, the pawl 202, and the rotor 56 are rotated in the forward direction, and the clutch gear 44 is rotated in the winding direction, and the adapter 38, the torsion shaft and the winding shaft are integrally formed with the clutch gear 44 by the operation of the clutch mechanism 46. The take-up shaft 20 is rotated with a high load (high torque) in the winding direction. For this reason, since the webbing 22 is wound around the winding shaft 20 with a high load, the occupant can be effectively restrained by the webbing 22 before the emergency state of the vehicle.

  For this reason, also in this embodiment, the same operation and effect as the first embodiment can be obtained except for the effect that the sliding load of the winding shaft 20 can be set to the second limit load.

[Fifth Embodiment]
FIG. 11 is a front sectional view showing the main part of a webbing take-up device 250 according to a fifth embodiment of the present invention. FIG. 12 shows the main part of the webbing take-up device 250 in an exploded perspective view. Is shown.

  The webbing take-up device 250 according to the present embodiment has substantially the same configuration as that of the first embodiment, but differs in the following points.

  As shown in FIGS. 11 and 12, in the webbing take-up device 250 according to the present embodiment, in the overload release mechanism 52, a restriction tooth 54C is formed on the entire periphery of the end portion of the gear ring 54 on the high load mechanism 64 side. Has been.

  The rotor 56 is not provided with the engaging body 68 in the first embodiment. A cross-shaped locking hole 60B is formed coaxially in the base 60 of the rotor 56, and the locking hole 60B is opened to the high load mechanism 64 side.

  The high load mechanism 64 is a restriction mechanism different from that of the first embodiment.

  The high load mechanism 64 is provided with a substantially disc-shaped lock ring 252 as a communication means, and a locking portion 252A having a cross-shaped cross section is coaxially formed on the surface of the lock ring 252 on the overload release mechanism 52 side. It protrudes upward. The locking portion 252A is inserted (inserted) into the locking hole 60B of the rotor 56 (base 60). The locking portion 252A enables the rotor 56 and the lock ring 252 to rotate integrally, and the lock ring 252 Movement (sliding) toward the gear ring 54 is possible. On the surface of the lock ring 252 on the overload release mechanism 52 side, a predetermined number (two in this embodiment) of lock teeth 252B are formed to protrude at the outer peripheral portion.

  The switching mechanism 72 is not provided with the communication gear 74, the support groove 76, and the tension coil spring 78 in the first embodiment.

  Between the base 60 of the rotor 56 and the lock ring 252, a coil spring 102 is suspended as a release means. The coil spring 102 has an engaging portion 252 </ b> A of the lock ring 252 inserted inside, The lock teeth 252B of the lock ring 252 are separated from the restriction teeth 54C of the gear ring 54.

  The solenoid 80 of the switching mechanism 72 is fixed to the inside of the gear housing 34 on the side opposite to the pawl 202 of the rotor 56 (base 60).

  When the switching mechanism 72 is operated and the solenoid 80 is operated, the plunger 80A of the solenoid 80 presses the lock ring 252 so that the lock ring 252 moves toward the gear ring 54 against the urging force of the coil spring 102. By being moved, the lock ring 252 (lock tooth 252B) is brought into contact (engaged) with the gear ring 54 (regulation tooth 54C). As a result, the lock ring 252 allows the gear ring 54 and the rotor 56 to rotate integrally by rotating the gear ring 54 in the forward direction and rotating the rotor 56 in the reverse direction.

  On the other hand, when the operation of the switching mechanism 72 is released and the operation of the solenoid 80 is released, the pressing of the lock ring 252 by the plunger 80 </ b> A of the solenoid 80 is released, and the biasing force of the coil spring 102 is applied to the lock ring 252. As a result of the movement to the solenoid 80 side, the connection (meshing) of the lock ring 252 (lock tooth 252B) to the gear ring 54 (regulation tooth 54C) is released. Thereby, the rotor 56 can be rotated relative to the gear ring 54.

  Here, when the tongue is not locked to the buckle and the webbing 22 is not attached to the occupant, the solenoid 80 is not operated in the switching mechanism 72. For this reason, when the lock ring 252 of the high load mechanism 64 is moved to the solenoid 80 side by the biasing force of the coil spring 102, the lock teeth 252B of the lock ring 252 are separated from the regulating teeth 54C of the gear ring 54, and the rotor 56 Is allowed to rotate relative to the gear ring 54, and the lock ring 252 can always rotate (is idle) integrally with the rotor 56.

  Further, when the tongue is locked to the buckle and the webbing 22 is attached to the occupant, the solenoid 80 is operated in the switching mechanism 72 under the control of the control device 82. Therefore, the plunger 80A of the solenoid 80 presses the lock ring 252, and the lock ring 252 is moved toward the gear ring 54 against the urging force of the coil spring 102, so that the lock ring 252 (lock teeth 252B) is moved. The gear ring 54 (regulator tooth 54 </ b> C) is connected, and the lock ring 252 enables the gear ring 54 and the rotor 56 to rotate integrally by rotating the gear ring 54 in the forward direction and rotating the rotor 56 in the reverse direction.

  When the detection device 84 predicts the emergency state of the vehicle before detecting the emergency state of the vehicle, the motor 50 is positively driven at a high speed by the control of the control device 82 and the output gear 48 is rotated in the positive direction. Thus, the gear ring 54, the lock ring 252 and the rotor 56 are rotated in the forward direction, and the clutch gear 44 is rotated in the winding direction. The operation of the clutch mechanism 46 causes the adapter 38, the torsion shaft and the The winding shaft 20 is rotated with a high load (high torque) in the winding direction. For this reason, since the webbing 22 is wound around the winding shaft 20 with a high load, the occupant can be effectively restrained by the webbing 22 before the emergency state of the vehicle.

  For this reason, also in this embodiment, the same operation and effect as the first embodiment can be obtained except for the effect that the sliding load of the winding shaft 20 can be set to the second limit load.

  In the first to fifth embodiments, when the detection device 84 detects the seating of an occupant on the seat, the motor 50 is reversely driven at a low speed under the control of the control device 82. However, when the detection device 84 detects the seating of an occupant on the seat, the motor 50 may be reversely driven at high speed by the control of the control device 82. Moreover, the speed at which the motor 50 is reversely driven by the control of the control device 82 when the detection device 84 detects the seating of the occupant on the seat may be selectable or adjustable by the occupant or the like.

  Furthermore, in the said 1st Embodiment-5th Embodiment, when the latching | locking of the tongue to a buckle is cancelled | released, the motor 50 is positively driven at low speed by control of the control apparatus 82. FIG. However, when the locking of the tongue to the buckle is released, the motor 50 may be positively driven at high speed by the control of the control device 82. Moreover, the speed at which the motor 50 is normally driven by the control of the control device 82 when the locking of the tongue to the buckle is released may be made selectable or adjustable by an occupant or the like.

  In the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment, when the switching mechanism 72 is operated and when the switching mechanism 72 is released, the tongue is attached to the buckle. When locking and unlocking. However, in the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment, similarly to the third embodiment, when the switching mechanism 72 is operated and the operation of the switching mechanism 72 is released. When the webbing 22 is wound on the winding shaft 20 for a limited length and the tongue is locked to the buckle, the webbing 22 is pulled out (or the amount of winding) with respect to the winding shaft 20. May be a predetermined amount.

  Further, in the third embodiment, when the switching mechanism 72 is operated and when the switching mechanism 72 is released, the webbing 22 is wound on the winding shaft 20 by the limit length and the buckle is tongued. The webbing 22 was pulled out from the winding shaft 20 (or the winding amount) in the middle of the state in which the webbing was locked. However, in the third embodiment, as in the first embodiment, the second embodiment, the fourth embodiment, and the fifth embodiment, when the switching mechanism 72 is operated and the operation of the switching mechanism 72 is released. The tongue may be locked and unlocked with respect to the buckle.

  Further, in the first to fifth embodiments, the present invention is applied to a three-point support type seat belt device that supports the webbing 22 at three points. However, the present invention may be applied to a two-point support type seat belt device that supports the webbing 22 at two points.

DESCRIPTION OF SYMBOLS 10 Webbing winding device 20 Winding shaft 22 Webbing 42 Transmission mechanism 50 Motor 52 Overload release mechanism (first limiting mechanism)
64 High load mechanism (second limiting mechanism)
100 Webbing Winder 150 Webbing Winder 200 Webbing Winder 250 Webbing Winder

Claims (5)

A take-up shaft on which a webbing attached to the occupant is taken up;
A transmission mechanism connected to the winding shaft;
A motor connected to the transmission mechanism and rotating the winding shaft by transmitting rotation to the winding shaft via the transmission mechanism;
Provided in the transmission mechanism, transmits the rotation on the motor side to the winding shaft side, and is activated when the rotation limiting load applied to the winding shaft is equal to or higher than the first limiting load. A first limiting mechanism that limits transmission of rotation of the rotation to the winding shaft side;
A second limiting mechanism that limits the operation of the first limiting mechanism at a predetermined opportunity and transmits the rotation of the motor side of the first limiting mechanism to the winding shaft side;
A webbing take-up device comprising:   2. The webbing take-up device according to claim 1, wherein the second restricting mechanism switches between allowing and restricting the operation of the first restricting mechanism in accordance with a winding amount or a drawing amount of the webbing with respect to the take-up shaft.   The webbing take-up device according to claim 1 or 2, wherein the second restriction mechanism restricts the operation of the first restriction mechanism in a state where the webbing is mounted on an occupant.   The second limiting mechanism is operated when a rotation limiting load applied to the winding shaft is equal to or larger than a second limiting load that is larger than the first limiting load, and the rotation of the motor side toward the winding shaft is performed. The webbing take-up device according to any one of claims 1 to 3, wherein transmission is limited.   The rotation of the motor in the positive direction is transmitted to the winding shaft via the transmission mechanism, so that the winding shaft is rotated in the winding direction and the webbing is wound on the winding shaft. The rotation of the motor in the reverse direction is transmitted to the take-up shaft through the transmission mechanism, whereby the take-up shaft is rotated in the pull-out direction and the webbing is drawn out from the take-up shaft. The webbing take-up device according to any one of claims 4 to 5.

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