JP2020044931A - Seat belt retractor - Google Patents

Abstract

To provide a seat belt retractor with a pretensioner that is configured so that a spool stoppage position at the time when EA operation is finished is defined.SOLUTION: After slack of webbing is removed accompanying operation of a pretensioner 60, a spool 20 rotates while twisting a torsion bar 70, so that the webbing is pulled out. Thereby, a wedge pawl 150 is stuck between a stopper ring 110 and a stopper gear 82, and the stopper gear 82 screws forward and contacts a bearing plate 90 and stops there. This makes the stopper ring 110 stop, so that a stopper claw 120 turns to ride on an expanding piece 114, protrudes from an outer peripheral edge of a flange 23 and contacts a stopper protruding part 66 to stop the spool 20.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a seat belt retractor with a pretensioner used for a vehicle such as an automobile, and more particularly, to a seat belt retractor having a torsion bar incorporated in a spool.

  As a seat belt retractor with a pretensioner, a seat in which a torsion bar is inserted into an inner hole of a spool, one end of the torsion bar can be fixed to the spool, and the other end of the torsion bar can be locked to a frame of the seat belt retractor. Belt retractors are known (Patent Documents 1 and 2). In an emergency such as a vehicle collision, the pretensioner rotates the spool to wind up the webbing. Thereafter, the torsion bar is twisted by applying a force in the webbing unwinding direction to the spool, the spool is gradually rotated, and the webbing is gradually pulled out. Thereby, a part of the kinetic energy applied to the occupant's body is absorbed by the torsion bar torsion, and the impact is reduced.

  Patent Literature 1 describes that the amount of torsion of a torsion bar is limited by movement of a stopper screwed to the torsion bar.

JP-A-11-222100 JP 2017-154525 A

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a seat belt retractor with a pretensioner that defines a spool rotation stop position at the end of an EA operation.

The seat belt retractor according to the present invention includes a frame for supporting a spool and a locking base, a cylindrical spool having an inner hole and a flange for winding up a webbing, and a coaxially disposed spool adjacent to the spool. The torsion bar, which is inserted through an inner hole of the spool, is rotatably connected at one end to the spool, and is rotatably connected at the other end to the locking base, A pretensioner for rotating the locking base in the webbing winding direction, comprising a pretensioner having a housing adjacent to the flange of the spool, wherein a male screw is provided on an outer peripheral surface of the locking base, A female screw on the inner peripheral surface of the stopper gear is screwed to the male screw, In the seat belt retractor in which the stopper gear is screwed along the locking base when the spool rotates and the locking base stops rotating, the stopper gear is disposed on the outer periphery of the flange of the spool on the housing. A stopper convex portion is provided at a position facing the stopper, and a stopper ring is tightly fitted in the inner hole of the spool, and the stopper ring rotates the spool, the torsion bar, and the locking base integrally. Sometimes, the spool is rotatable integrally with the spool, and when the spool rotates in the webbing withdrawal direction in a state where the rotation of the stopper ring is prevented, the spool slides on the outer peripheral surface of the stopper ring to be rotatable. There is a feature.
In one aspect of the present invention, the flange of the spool has a retracted posture retracted from an outer peripheral edge of the flange, and a protruded posture protruding from the outer peripheral edge of the flange and abutting on the stopper convex portion provided on the housing. And a stopper claw that is rotatable so as to be able to take a position.
In one aspect of the present invention, a spring is provided for urging the stopper claw to take a retracted posture, and the stopper ring projects from the outer peripheral edge of the stopper ring in a direction including a radial direction, An overhanging piece is provided to engage the stopper claw to cause the stopper claw to assume the protruding position, and at least a part of the stopper gear is disposed in the stopper ring. A wedge pawl is arranged between the peripheral surface and the stopper gear, and when the spool is rotated by the EA operation and the locking base stops rotating, the wedge pawl is disposed on the inner peripheral surface of the stopper ring. And is engaged between the inner peripheral surface of the stopper ring and the stopper gear, and the rotation of the spool is transmitted to the stopper gear and the stopper gear is rotated. When the stopper gear moves to the screw advance limit, the rotation of the stopper ring is stopped by the stopper gear via the wedge pawl, and the stopper rotates by rotating the spool with respect to the stopper ring. A pawl is guided by the overhanging piece to take the protruding position, and is configured to engage with the stopper convex portion, and an urging member for urging the wedge pawl in a direction opposite to the biting direction is provided. Have been.

  In one aspect of the present invention, a wedge pawl holding groove extending in a direction parallel to an axis of the stopper ring is provided on an inner peripheral surface of the stopper ring, and the wedge pawl is provided on the wedge pawl holding groove. The stopper ring is engaged and is movable in the circumferential direction along the inner peripheral surface of the stopper ring.

  In one aspect of the present invention, each of the wedge pawl holding grooves has a first groove surface and a second groove surface that fall from the inner peripheral surface of the stopper ring, and the wedge pawl includes the first groove surface. , A second back surface slidably overlapping the second groove surface, and a tooth portion meshing with the outer peripheral surface of the stopper gear.

  In one aspect of the present invention, the urging member is provided so as to press the first back surface against the first groove surface.

  In one aspect of the present invention, the wedge pawl holding groove extends in a direction parallel to the axis direction of the stopper ring, and is provided at one end of the wedge pawl holding groove and one end of the wedge pawl, respectively. Projections are provided, and a tension coil spring as the urging member is provided between the projections.

  In one aspect of the present invention, outward teeth with which the teeth of the wedge pawl engage are provided on the outer peripheral surface of the stopper gear.

  In one aspect of the present invention, the flange portion of the spool includes a pivot pin that rotatably supports the stopper claw and a receiving protrusion that receives the stopper claw that has been rotated to take the protruding posture. Is provided.

  In one aspect of the present invention, a non-circular portion is provided on a base end side of the shaft portion of the locking base, a paddle wheel is provided on the non-circular portion, and the housing is provided so as to surround the paddle wheel. When the power transmission member from the pretensioner moves along the outer peripheral surface of the paddle wheel, the locking base, the torsion bar, and the spool rotate in the webbing winding direction.

  In one aspect of the present invention, a bearing plate is mounted on the spool side relative to the paddle wheel on the non-circular portion of the locking base, and the stopper gear is capable of screwing until it comes into contact with the bearing plate. Has become.

  In one aspect of the present invention, a plurality of the stopper projections and the stopper claws are provided at intervals in a circumferential direction of an outer peripheral edge of the flange.

  In the seat belt retractor of the present invention, before an emergency such as a vehicle collision or the like (hereinafter, referred to as a vehicle collision), the spool, the torsion bar, and the locking base rotate integrally, so that the webbing can be pulled out and taken up. Done.

  At the time of a vehicle collision, the pretensioner operates, and the locking base, the torsion bar, and the spool rotate in the webbing winding direction, and the slack of the webbing is eliminated. Even after the slack of the webbing has been eliminated, the pretensioner further applies a force in the winding direction to the torsion bar, so that the torsion bar slightly twists in the winding direction, but at this time, the gear rotates together with the locking base, The stopper gear does not advance.

  Then, when the force in the pull-out direction applied to the webbing from the occupant body becomes greater than the force in the winding direction applied from the pretensioner, the locking base is kept in a rotation stopped state by the pressure holding action of the pretensioner, and the spool releases the torsion bar. It rotates while twisting, the webbing is pulled out, and the occupant performs EA (energy absorption).

  Further, the gear is screwed with the rotation of the spool at this time, and then the gear is screwed to a predetermined position and stopped. The stopper ring and the spool try to rotate further. The stopper ring is prevented from rotating by the stopper gear via the wedge pawl. Along with this, the stopper claw of the spool is guided by the projecting piece of the stopper ring, protrudes from the outer peripheral edge of the flange of the spool, and comes into contact with the stopper projection provided on the pretensioner. This stops the spool.

FIG. 2 is an exploded perspective view of the seat belt retractor according to the embodiment, as viewed from the front. FIG. 2 is an exploded perspective view of the seatbelt retractor according to the embodiment, as viewed from the back. FIG. 2 is a top view of the seat belt retractor according to the embodiment. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. It is a perspective view of a spool and a pretensioner. It is the exploded perspective view seen from the left side of the spool. It is the disassembled perspective view seen from the right side of the spool. It is explanatory drawing which shows a wedge pawl operation. It is explanatory drawing which shows a wedge pawl operation. FIG. 4 is an exploded perspective view showing an engagement relationship between a spool and a wedge pawl.

  Hereinafter, embodiments will be described with reference to the drawings.

  The seat belt retractor 1 includes a frame 10, a spool 20 rotatably held by the frame 10, a return spring unit (spring spring unit) 30 for urging the spool 20 in a webbing winding direction, and a coaxial shape with the spool 20. And a locking base 40 connected to the spool 20 by a torsion bar 70, a lock activation unit 50 for activating the lock of the spool 20, a pretensioner 60, and a connection between the spool 20 and the locking base 40. The spool 20 includes a torsion bar 70 inserted into the spool 20 and the locking base 40, a stopper gear 82 which advances during EA operation, a stopper ring 110 and a stopper claw 120 for controlling rotation stop of the spool 20, and the like.

  The frame 10 is provided on the front wall 11, the left wall 12 extending forward from the left side of the front wall 11, the right wall 13 extending forward from the right side, and the respective side walls 12, 13. It has spool insertion holes 15, 16 and the like. Saw teeth 16 a are provided on the inner peripheral surface of the spool insertion hole 16.

  The return spring unit 30 contains a mainspring spring in a case, and one end of the mainspring is connected to a projecting shaft 20 t on the left end side of the spool 20. The return spring unit 30 is attached to the left frame wall 12.

  The lock activation unit 50 has a lock assembly 52 in which a pendulum 51 (FIG. 2) held on the right side wall 13 of the frame is engaged with the outer peripheral surface. When the rotation angular acceleration of the lock assembly 52 becomes equal to or more than a predetermined value, or when the pendulum 51 engages with the outer peripheral surface of the lock assembly 52, the lock assembly 52 projects the pawl 43 from the outer peripheral surface of the locking base 40 to the saw tooth 16a. Engage.

  The lock assembly 52 and the pendulum 51 are covered by a cover 55.

  The lock activation unit 50 has a known structure.

  The pretensioner 60 is for removing the slack of the webbing by winding the spool 20 with a large torque in the webbing winding direction at the time of a vehicle collision. The pretensioner 60 includes a gas generator 61 for generating gas upon a vehicle collision, a duct 62, a housing 65 surrounding a paddle wheel 80 described later, and a power transmission member made of a synthetic resin or the like loaded in the duct 62. Etc. are provided. The power transmission member is sent to the outer circumference of the paddle wheel 80 in the housing 65 in the circumferential direction by the gas pressure from the gas generator 61, and the spool 20 rotates in the webbing winding direction. This configuration can be, for example, that described in Patent Document 2.

  In FIG. 3, illustration of the duct 62 and the gas generator 61 is omitted.

  A stopper convex portion 66 is provided on the side surface of the housing 65 on the side of the spool 20 along the outer peripheral surface of the right flange 23 of the spool 20 at a position equally divided in the circumferential direction (four equally divided position in this embodiment).

  Next, the structure of the spool, the locking base 40, the stopper ring 110, and the like will be described in detail.

  The spool 20 has a tubular portion 21 around which the webbing is wound, a left flange 22 on the left end side of the tubular portion 21, and a right flange 23 on the right end side.

  On the end face of the right flange 23, a receiving convex portion 27 is provided at a position equally divided in the circumferential direction (in this embodiment, a position divided equally by four). The receiving projection 27 is provided so as to rise from the flange surface. Further, a shaft-shaped support pin 28 is provided near each of the receiving protrusions 27. The support pin 28 stands upright from the flange surface in a direction parallel to the axis of the spool 20.

  The small hole 121 of the stopper claw 120 is engaged with the pin 28, and the stopper claw 120 is arranged rotatably along the flange surface of the right flange 23. An L-shaped leaf spring 130 is interposed between the stopper claw 120 and the receiving protrusion 27. The leaf spring 130 urges the stopper claw 120 in a direction to separate the stopper claw 120 from the receiving protrusion 27.

  An inner hole 29 is provided in the cylindrical portion 21 of the spool 20 from the right end to the left end. A serration portion is provided at the innermost portion of the inner hole 29, and a gear-shaped portion 71 of the torsion bar 70 is engaged with the serration portion.

  A locking base 40 is disposed adjacent to the right side of the spool 20 so as to be coaxial with the cylindrical portion 21. The locking base 40 includes a flange portion 41, a cylindrical shaft portion 42 connected to the center of the flange portion 41, a pawl 43 provided on the flange portion 41, and the like.

  A serration portion is provided on the inner peripheral surface of the inner hole 42a of the shaft portion 42, and a gear-shaped portion 72 at the right end of the torsion bar 70 is engaged with the serration portion.

  A hexagonal portion 42b as a non-circular portion is provided on the outer periphery of the base end side (flange 41 side) of the shaft portion 42 of the locking base 40, and a male screw 42c is provided on the outer peripheral surface on the distal end side.

  A hexagonal inner hole 80a of the paddle wheel 80 is engaged with the hexagonal portion 42b, and the paddle wheel 80 is mounted on the shaft portion 42 so as not to rotate in the circumferential direction.

  When a power transmission member made of synthetic resin or the like is supplied from the duct 62 of the pretensioner 60 into the housing 65 around the outer periphery of the paddle wheel 80, the paddle wheel 80 rotates and the locking base 40 rotates.

  The hexagonal portion 42b also engages with the hexagonal inner hole 90a of the bearing plate 90.

  A female screw 82a on the inner peripheral surface of the center hole of the stopper gear 82 is screwed to the male screw 42c. The stopper gear 82 is capable of screwing along the male screw 42c.

  The stopper gear 82 is arranged in the ring main body 111 of the stopper ring 110.

  The entrance side of the inner hole 29 has a large diameter, and a stopper ring 110 is fitted in this portion. The stopper ring 110 is fitted around the stopper gear 82.

  The stopper ring 110 includes a ring main body 111, a plurality of ridges 112 provided on the outer peripheral surface of the ring main body 111, a projecting piece 114 fixed to one end surface of the ring main body 111, It has a wedge pawl holding groove 140 and the like provided on the peripheral surface.

  The ridge 112 extends in a direction parallel to the axial direction of the ring main body 111. A plurality of ridges 112 are provided at intervals in the circumferential direction of the ring main body 111.

  The projecting piece 114 protrudes radially from the outer peripheral surface of the ring main body 111. A plurality (four in this embodiment) of projecting pieces 114 are provided at equal intervals in the circumferential direction of the ring main body 111.

  The ring main body 111 is tightly fitted in the inner hole 29. However, when a predetermined torque or more is applied, the inner peripheral surface of the inner hole 29 and the outer peripheral surface of the ring main body 111 slide to rotate the spool 20. It is configured to work. In addition, the convex ridge 112 is pressed against the inner peripheral surface of the inner hole 29. The projecting piece 114 extends along the end surface of the right flange 23 of the spool 20.

  Two wedge pawl holding grooves 140 are provided with the axis of the ring main body 111 interposed therebetween. The wedge pawl holding groove 140 is a substantially V-shaped groove having a first groove surface 141 and a second groove surface 142 that fall from the inner peripheral surface of the ring main body 111, respectively.

  As shown in FIG. 10, a pin-shaped protrusion 143 that stands in a direction parallel to the axis of the ring main body 111 is provided at the intersection of the first groove surface 141 and the second groove surface.

  A wedge pawl 150 is arranged in each wedge pawl holding groove 140. The wedge pawl 150 has a first back surface 151 in contact with the first groove surface 141 and a second back surface 152 slidably overlapping the second groove surface 142. On one end surface of the wedge pawl 150, a protrusion 153 that stands in a direction parallel to the axis of the ring main body 111 is provided.

  The wedge pawl 150 is provided with teeth 154 and 155 that engage with the outward teeth 82T of the stopper gear 82. The teeth 154 and 155 extend in a direction parallel to the axis of the spool 20.

  The wedge pawl 150 is engaged with the wedge pawl holding groove 140, and a tension coil spring 160 as an urging member is bridged between the protrusion 153 of the wedge pawl 150 and the protrusion 143 of the ring main body 111. One hook 161 of the spring 160 is engaged with the projection 143, and the other hook 162 is engaged with the projection 153. By being pulled by the spring 160, the wedge pawl 150 is urged in a direction in which the first back surface 151 is pressed against the first groove surface 141.

  A female screw 82a on the inner peripheral surface of the stopper gear 82 is screwed to the male screw 42c. The stopper gear 82 is capable of screwing along the male screw 42c. On the outer peripheral surface of the stopper gear 82, serrated outward teeth 82T are provided. The outward teeth 82T extend on the outer peripheral surface of the stopper gear 82 in a direction parallel to the axis of the stopper gear 82. The outward teeth 82T have a saw-tooth shape that is inclined toward one of the circumferential directions of the stopper gear 82.

  In the seat belt retractor described above, the stopper gear 82 is normally screwed to the most distal end side of the male screw 42c of the locking base 40. The paddle wheel 80 and the bearing plate 90 are engaged with the hexagonal portion 42b, and the stopper ring 110 is tightly fitted in the inner hole 29. Normally, the wedge pawl 150 is not engaged with the saw tooth 82T, and the locking base 40, the paddle wheel 80, the bearing plate 90, the stopper ring 110, the torsion bar 70, and the spool 20 can rotate integrally. Therefore, the webbing is pulled out and wound up according to the position of the occupant.

  As described above, in the state before the vehicle collision, the stopper gear 82 is located at the most distal end side of the male screw 42c. In this state, the wedge pawl 150 is pulled by the spring 160 and is in contact with the first groove surface 141, so that the wedge pawl 150 and the stopper gear 82 are separated from each other. In this state, the stopper claw 120 is urged by the leaf spring 130 and abuts on the distal end surface of the overhanging piece 114 as shown in FIG. Is located closer to the axis of the spool 20.

  At the time of a vehicle collision, the pendulum 51 is engaged with the outer peripheral surface of the lock assembly 52, and the lock activation unit 50 causes the first pawl 43 to protrude from the outer peripheral surface of the locking base 40. The protruding pawl 43 engages with the saw tooth 16 a of the right side wall 13.

  Further, at the time of a vehicle collision, the gas generator 61 of the pretensioner 60 is operated, and a strong torque in the webbing winding direction is applied to the locking base 40 via the paddle wheel 80, so that the locking base 40, the torsion bar 70 and the spool 20 are rotated. Rotate together in the webbing winding direction. Thereby, the webbing is wound around the spool 20, and the slack of the webbing is removed.

  In this state, the locking base 40 rotates in the webbing winding direction without being restrained by the saw teeth 16a. Further, the spool 20 and the locking base 40 are integrally rotated at the same rotational speed in the same direction, and the stopper gear 82 is also integrally rotated with the locking base 40 at the same rotational speed in the same direction. The locking base 40 remains at the forefront side.

  When the winding of the webbing advances and the slack of the webbing is removed, the winding of the webbing by the spool 20 stops. As described above, even after the slack of the webbing is removed, a force is applied to the torsion bar 70 from the pretensioner 60 in the webbing winding direction, whereby the torsion bar 70 is twisted. At this stage, the spool 20 is stopped, and the wedge pawl 150 is separated from the stopper gear 82. Since no rotational force is applied to the stopper gear 82, the stopper gear 82 remains at the original position.

  Thereafter, the spool 20 starts rotating in the webbing pull-out direction θ (counterclockwise direction in FIGS. 8 and 9) while twisting the torsion bar 70 by the force in the webbing pull-out direction applied from the webbing to the spool 20 (EA operation). The locking base 40 connected to the spool 20 via the torsion bar 70 is prevented from rotating in the webbing pull-out direction by the pressure-holding action of the pretensioner 60. As a result, the spool 20 rotates in the θ direction while twisting the torsion bar 70, and the webbing is pulled out. Due to the torsional deformation of the torsion bar 70, the driving energy of the occupant moving forward is absorbed.

  In this case, since the stopper ring 110 is tightly fitted in the inner hole 29, the stopper ring 110 rotates integrally with the spool 20.

  When the stopper ring 110 rotates in the webbing pull-out direction integrally with the spool 20 in the state where the locking base 40 is stopped, as shown in FIG. 8, the wedge pawl 150 is moved to the first groove surface by its own inertia force. It moves along the second groove surface 142 in a direction away from the object 141 (anti-θ direction). As a result, the teeth 154 and 155 engage the outward teeth 82T of the stopper gear 82, and the wedge pawl 150 is engaged between the inner peripheral surface of the stopper ring 110 and the stopper gear 82. As a result, the rotation of the spool 20 is transmitted to the stopper gear 82 via the wedge pawl 150, and the stopper gear 82 rotates. At this time, since the locking base 40 is stopped, the stopper gear 82 is screwed (thrust-moved) toward the base end side of the locking base 40, that is, toward the flange portion 41 side.

  When the stopper gear 82 rotates a predetermined number of times, the stopper gear 82 comes into contact with the bearing plate 90, and further rotation and screwing are disabled. Although the stopper ring 110 is tightly fitted into the inner hole 29 of the spool 20, when a strong torque greater than a predetermined value acts on the spool 20, the inner peripheral surface of the inner hole 29 slides with the stop ring 110. It can move and rotate. Therefore, even after the stopper gear 82 stops, the spool 20 further slightly rotates in the θ direction.

  Then, the stopper claw 120 rises and pivots from the state shown in FIG. 8 to the state shown in FIG. 9 so as to ride on the overhanging piece 114, and the tip of the stopper claw 120 projects from the outer peripheral edge of the right flange 23. When the distal end of the stopper claw 120 protrudes from the outer peripheral edge of the right flange 23, the distal end of the stopper claw 120 comes into contact with the stopper convex portion 66 of the housing 65 as shown in FIG. I do.

  As described above, the stopper claw 120 and the stopper convex portion 66 are engaged with each other, and the rotation of the spool 20 in the webbing pull-out direction is prevented, so that the occupant stops moving forward.

  The above embodiment is an example of the present invention, and the present invention may be applied to other aspects.

DESCRIPTION OF SYMBOLS 1 Seat belt retractor 10 Frame 11 Front wall 12 Left side wall 13 First right side wall 14 Second right side wall 16a Saw tooth 20 Spool 22 Left flange 23 Right flange 27 Receiving projection 28 Support pin 30 Return spring unit 40 Locking base 41 Flange Part 42 shaft part 42c male screw 43 pawl 50 lock activation unit 52 lock assembly 60 pretensioner 70 torsion bar 80 paddle wheel 82 stopper gear 82T outward teeth 90 bearing plate 110 stopper ring 112 ridge 114 projecting piece 120 stopper claw 130 leaf spring 140 Wedge pawl holding groove 141 First groove surface 142 Second groove surface 143 Projection 150 Wedge pawl 151 First rear surface 152 Second rear surface 153 Projection 154, 155 Tooth portion 60 tension coil spring

Claims (12)

A frame supporting the spool and the locking base,
Winding the webbing, the cylindrical spool having an inner hole and a flange,
A locking base disposed coaxially adjacent to the spool and connected to the spool by a torsion bar;
A torsion bar inserted through the inner hole of the spool, one end of which is non-rotatably connected to the spool, and the other end of which is non-rotatably connected to the locking base;
A pretensioner for rotating the locking base in a webbing winding direction, the pretensioner having a housing adjacent to the flange of the spool,
With
A male screw is provided on the outer peripheral surface of the locking base,
A female screw on the inner peripheral surface of the stopper gear is screwed into the male screw,
In the seat belt retractor in which the stopper gear is screwed along the locking base when the spool is rotated by the EA operation and the locking base stops rotating,
A stopper projection is provided on the housing at a position facing the outer peripheral edge of the flange of the spool,
A stopper ring is tightly fitted in the inner hole of the spool, and the stopper ring is rotatable integrally with the spool when the spool, the torsion bar, and the locking base rotate integrally. A seat belt retractor wherein the spool slides on the outer peripheral surface of the stopper ring and is rotatable when the spool rotates in the webbing withdrawal direction while the rotation of the ring is prevented.   The flange of the spool is rotated so that it can have a retracted posture retracted from the outer peripheral edge of the flange and a protruded posture protruding from the outer peripheral edge of the flange and abutting on the stopper projection provided on the housing. 2. The seat belt retractor according to claim 1, further comprising a movable stopper claw. A spring is provided for urging the stopper claw to take a retracted posture,
An overhanging piece is provided on the stopper ring, which protrudes from the outer peripheral edge of the stopper ring in a direction including the radial direction, and engages with the stopper claw to cause the stopper claw to assume the projecting position;
At least a part of the stopper gear is arranged in the stopper ring,
A wedge pawl is arranged between the inner peripheral surface of the stopper ring and the stopper gear,
When the spool is rotated by the EA operation and the locking base stops rotating, the wedge pawl moves along the inner peripheral surface of the stopper ring to move the stopper gear between the inner peripheral surface of the stopper ring and the stopper gear. When the rotation of the spool is transmitted to the stopper gear and the stopper gear is screwed, and the stopper gear is moved to the limit of the screw movement, the rotation of the stopper ring is rotated through the wedge pawl to stop the stopper gear. Stopped by a gear, the spool is rotated with respect to the stopper ring, so that the stopper claw is guided by the overhanging piece to take the protruding posture, and is configured to engage with the stopper protrusion.
The seat belt retractor according to claim 2, further comprising an urging member for urging the wedge pawl in a direction opposite to the biting direction. On the inner peripheral surface of the stopper ring, a wedge pawl holding groove extending in a direction parallel to an axis of the stopper ring is provided,
The seat belt retractor according to claim 3, wherein the wedge pawl is engaged with the wedge pawl holding groove, and is movable in a circumferential direction along an inner peripheral surface of the stopper ring.   The wedge pawl holding groove has a first groove surface and a second groove surface respectively falling from the inner peripheral surface of the stopper ring, and the wedge pawl has a first back surface abutting on the first groove surface. 5. The seat belt retractor according to claim 4, further comprising a second back surface slidably overlapping the second groove surface, and a tooth portion meshing with the outer peripheral surface of the stopper gear.   The seat belt retractor according to claim 5, wherein the urging member is provided so as to press the first back surface against the first groove surface. The wedge pawl holding groove extends in a direction parallel to the axial direction of the stopper ring,
Projections are provided on one end side of the wedge pawl holding groove and one end of the wedge pawl, respectively.
The seat belt retractor according to claim 6, wherein a tension coil spring as the urging member is provided between the projections.   The seat belt retractor according to any one of claims 3 to 7, wherein outward gear teeth with which the teeth of the wedge pawl engage are provided on an outer peripheral surface of the stopper gear.   The flange portion of the spool is provided with a pivot pin for rotatably supporting the stopper claw and a receiving convex portion for receiving the stopper claw rotated to take the protruding posture. The belt retractor according to any one of claims 3 to 8, wherein A non-circular portion is provided on a base end side of the shaft portion of the locking base, and a paddle wheel is provided on the non-circular portion,
The housing is provided so as to surround the paddle wheel,
The power transmission member from the pretensioner moves along the outer peripheral surface of the paddle wheel, whereby the locking base, torsion bar, and spool rotate in the webbing winding direction. A seat belt retractor according to any one of the preceding claims. A bearing plate is mounted on the spool side relative to the paddle wheel on the non-circular portion of the locking base,
The retractor according to claim 10, wherein the stopper gear is capable of screwing until it comes into contact with the bearing plate.   The seat belt retractor according to any one of claims 3 to 11, wherein a plurality of the stopper protrusions and the stopper claws are provided at intervals in a circumferential direction of an outer peripheral edge of the flange.

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