JP2007186033A - Webbing retractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a webbing retractor suppressing the relative movement of a rotor with respect to a frame with a rotation prevention member engaged, without highly accurately manufacturing the rotor or a winding shaft. <P>SOLUTION: In the webbing retractor 10, an inclined surface 138B of a pawl 138 is abutted on the inclined surface 136A of an external tooth 136 in a state that the pawl 138 is engaged with a gear 132 for WSIR, so that a force toward one end side in an axial direction acts on the gear 132 for WSIR and the gear 132 for WSIR is abutted on (pushed against) a wall part 68A of a sensor holder 68. Therefore, even if dimension accuracy between a bearing hole 133 of the gear 132 for WSIR and a small-diameter shaft 16C of a spool 16 is small and an outer peripheral part of the gear 132 for WSIR is loose in an axial direction with respect to the spool 16, the relative movement in the axial direction with respect to the frame 12 of the gear 132 for WSIR in the engaged state can be suppressed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a webbing take-up device.

  A conventional webbing take-up device (see, for example, Patent Document 1) includes a lock mechanism (so-called “WSIR”) that locks the rotation of the take-up shaft when the webbing is suddenly drawn. The lock mechanism includes a V gear supported so as to be rotatable relative to the take-up shaft, and a WSIR pawl rotatably supported by the V gear. The V gear is held on the take-up shaft by the urging force of the torsion coil spring, and is normally restricted from moving relative to the take-up shaft.

  Further, the webbing take-up device shown in the above-mentioned patent document is a rotating body (for WSIR) that is coaxially opposed to the V gear and is relatively rotatable, and has inner and outer teeth formed on the outer peripheral portion. And a rotation prevention member (rotation prevention pawl) that is rotatably supported by a sensor cover attached to the frame and normally engages with the external teeth of the WSIR gear to prevent the rotation of the WSIR gear. ).

  In the webbing take-up device configured as described above, when the webbing is suddenly pulled out, the WSIR pawl engages with the internal teeth of the WSIR gear, thereby preventing the rotation of the V gear. The lock plate provided in the is engaged with the frame, and the winding shaft is prevented from rotating in the webbing pull-out direction.

  On the other hand, when the entire webbing is wound on the winding shaft, the rotation preventing pawl is detached from the WSIR gear. In this state, even if the WSIR pawl is engaged with the internal teeth of the WSIR gear, the rotation of the V gear is not prevented, thereby preventing the so-called end lock.

By the way, in the webbing take-up device configured as described above, the WSIR gear is supported so as to be rotatable relative to the take-up shaft by inserting the small-diameter shaft of the take-up shaft through a bearing hole formed in the shaft center portion. It is a configuration. Therefore, when the dimensional accuracy between the small-diameter shaft and the bearing hole is not high, the WSIR gear has an outer peripheral portion (inner teeth) in the axial direction with respect to the frame even when the rotation prevention pawl is engaged. In addition, relative movement in the circumferential direction (backlash) may occur, and the relative positional relationship with respect to the V gear may change. In order to suppress such rattling and to make the relative positional relationship of the WSIR gear (inner teeth) with respect to the WSIR pawl in a state in which the rotation preventing pawl is engaged, for example, with respect to the small-diameter shaft, This can be dealt with by increasing the bearing hole support area or molding the small-diameter shaft and the bearing hole with high precision.However, there is a problem in the former case that it hinders downsizing of the device. There is a problem that the design and manufacture of the WSIR gear (rotating body) and the winding shaft become complicated.
JP 2004-90672 A

  In view of the above facts, the present invention provides a webbing take-up device that can suppress relative movement of the rotating body with respect to the frame when the rotation preventing member is engaged without manufacturing the rotating body and the winding shaft with high accuracy. The purpose is to obtain.

  A webbing take-up device according to a first aspect of the present invention includes a frame, a take-up shaft that is pivotally supported by the frame and takes up an occupant-restraining webbing, and the take-up when the webbing is suddenly pulled out. A lock mechanism that locks the rotation of the shaft in the webbing pull-out direction, and a rotation mechanism that is rotatably provided. When the rotation of the shaft is blocked, the lock mechanism can be operated and the rotation of the shaft is permitted. A rotating body that disables the locking mechanism and supported by the frame, and normally engages with the rotating body to prevent rotation of the rotating body, and the webbing is wound up around the winding shaft. A rotation preventing member that is released from the rotating body to release the blocking, and the rotating body is moved in the axial direction with respect to the frame with the rotation preventing member engaged with the rotating body. Is characterized by comprising a restraining means for restraining the non pairs move.

  In the webbing retractor according to the first aspect, the rotation preventing member is normally engaged with the rotating body, and the rotation of the rotating body is blocked by the rotation preventing member. In this state, the lock mechanism is operable, and when the webbing is suddenly pulled out, the rotation of the winding shaft in the webbing pull-out direction is locked by the lock mechanism. On the other hand, when the webbing is completely wound on the winding shaft, the rotation preventing member is detached from the rotating body and the rotation preventing of the rotating body is released. This disables the lock mechanism. Therefore, when the webbing is completely wound on the winding shaft, it is possible to prevent the lock mechanism from operating unnecessarily and so-called end lock.

  Here, in this webbing take-up device, the restraining means restrains the rotating body from moving relative to the frame in the axial direction with the rotation preventing member engaged with the rotating body. Therefore, in this webbing take-up device, it is possible to suppress relative movement along the axial direction of the rotating body with respect to the frame when the rotation preventing member is engaged without manufacturing the rotating body and the winding shaft with high accuracy. .

  A webbing take-up device according to a second aspect of the present invention is the webbing take-up device according to the first aspect, wherein the restraining means is attached to the frame, and a wall portion facing one end in the axial direction of the rotating body, The rotating body is provided on at least one of the rotating body and the rotation preventing member, and a force directed toward the one end side in the axial direction is applied to the rotating body in a state where the rotation preventing member is engaged with the rotating body, and the rotating body is placed on the wall And a surface to be brought into contact with the portion.

  In the webbing take-up device according to claim 2, in a state where the rotation preventing member is engaged with the rotating body, a surface provided on at least one of the both applies a force directed to one end side in the axial direction to the rotating body. The rotating body is brought into contact with a wall portion attached to the frame. Thereby, the rotating body is restrained so as not to move relative to the frame in the axial direction.

  According to a third aspect of the present invention, there is provided a webbing take-up device, a frame, a take-up shaft that is pivotally supported by the frame and takes up an occupant-constrained webbing, and the take-up unit when the webbing is suddenly pulled out. A lock mechanism that locks the rotation of the shaft in the webbing pull-out direction, and a coaxial mechanism that can rotate relative to the winding shaft, and enables the lock mechanism to operate when the rotation of the shaft is blocked. A rotating body that disables the locking mechanism in a state in which the rotation of the rotating body is permitted, and a frame that is supported by the frame and normally engages with the rotating body to prevent the rotating body from rotating. When the webbing is fully wound on the winding shaft, the webbing is detached from the rotating body to release the blocking, and is attached to the frame, and the rotation blocking member is rotated. It is characterized abutting portion abutting against the end portion of the webbing pull-out direction side of the rotation preventing member in engagement with, the equipped with a.

  In the webbing take-up device according to the third aspect, the rotation preventing member is normally engaged with the rotating body, and the rotation of the rotating body is blocked by the rotation preventing member. In this state, the lock mechanism is operable, and when the webbing is suddenly pulled out, the rotation of the winding shaft in the webbing pull-out direction is locked by the lock mechanism. On the other hand, when the webbing is completely wound on the winding shaft, the rotation preventing member is detached from the rotating body and the rotation preventing of the rotating body is released. This disables the lock mechanism. Therefore, when the webbing is completely wound on the winding shaft, it is possible to prevent the lock mechanism from operating unnecessarily and so-called end lock.

  Here, in this webbing take-up device, when the rotation prevention member engages with the rotating body, the contact portion attached to the frame contacts the end portion of the rotation prevention member on the webbing pull-out direction side, and the frame of the rotation prevention member Relative movement in the webbing pull-out direction is prevented. Therefore, for example, even when there is a backlash in the support portion of the rotation prevention member with respect to the frame, the back surface does not move relative to the frame in the webbing pull-out direction due to this backlash.

  The webbing take-up device according to a fourth aspect of the present invention is the webbing take-up device according to any one of the first to third aspects, wherein the rotating body has engaging teeth, and the rotation preventing member is And an engaging claw that fits into the valley portion of the engaging tooth in a state of being engaged with the rotating body and prevents relative displacement of the rotating body with respect to the rotation preventing member along the circumferential direction. It is a feature.

  5. The webbing take-up device according to claim 4, wherein the engaging claw provided on the rotation preventing member is fitted in a valley portion of the engaging tooth provided on the rotating body in a state where the rotation preventing member is engaged with the rotating body. The relative positional deviation along the circumferential direction with respect to the rotation preventing member of the rotating body is prevented. Therefore, the positioning accuracy of the rotating body with respect to the frame is not deteriorated due to the circumferential displacement (backlash) of the rotating body with respect to the rotation preventing member in the engaged state.

  As described above, in the webbing take-up device according to the present invention, the relative movement of the rotating body with respect to the frame with the rotation preventing member engaged is possible without manufacturing the rotating body and the take-up shaft with high accuracy. Can be suppressed.

  Hereinafter, a webbing retractor 10 according to an embodiment of the present invention will be described with reference to FIGS.

[Overall configuration of webbing take-up device 10]
First, the overall configuration of the webbing take-up device 10 according to the present embodiment will be described, and then the main part of the webbing take-up device 10 will be described.

  FIG. 1 shows a cross-sectional view of the overall configuration of a webbing take-up device 10 according to the present embodiment. FIG. 2 is an exploded perspective view of the spool and the lock plate. 3 and 4 show a state before and after the operation of the WSIR W sensor in a side view, and FIGS. 5 and 6 show a state before and after the lock plate is locked in a side view. 2 to 6 and the like, the direction A appropriately added indicates the webbing drawing rotation direction, and the direction B indicates the webbing take-up rotation direction.

  As shown in FIG. 1, the webbing take-up device 10 includes a metal frame 12 formed in a U shape in plan view. The frame 12 is fixed to the lower end side of the vehicle body side by bolting. Further, on both side portions 12A and 12B of the frame 12, a high-strength internal tooth ratchet 14 constituting a lock mechanism is formed coaxially by punching.

  Cylindrical spools 16 as “winding shafts” are pivotally supported on both side portions 12 </ b> A and 12 </ b> B of the frame 12. A rotating shaft 16A is integrally formed at one axial end portion of the axial center portion of the spool 16, and an inner end of a spring (not shown) that is grasped as “biasing means” in a broad sense. Is locked. Thereby, the spool 16 is always urged to rotate in the webbing take-up rotation direction (direction B). On the other hand, a rotating shaft 16B is formed coaxially with the rotating shaft 16A at the other end in the axial direction of the spool 16, and a small-diameter shaft 16C is formed coaxially with the tip of the rotating shaft 16B. Yes. The spool 16 is rotatably supported by a bearing hole 68B formed in a wall portion 68A of the sensor holder 68 described later on the small diameter shaft 16C. Further, the base end portion of the occupant restraining webbing 18 is locked to the spool 16, and the spool 16 can be wound and pulled out by rotation. The spool 16 is restricted from moving relative to the frame 12 along the axial direction.

  Further, as shown in FIG. 2, a notch 20 is formed in the outer peripheral portion of the spool 16 along the axial direction. The notch 20 is formed along the axial direction over the entire length of the spool 16 except for the rotation shafts 16A and 16B and the small-diameter shaft 16C, and the bottom is formed in a semicircular arc shape. Further, a pair of recesses 22 are formed at both ends of the spool 16 in the axial direction.

  The notch 20 and the recess 22 of the spool 16 are formed in a substantially U shape in a plan view and accommodate a lock plate 24 constituting a lock mechanism. The lock plate 24 includes a rod-like connecting shaft 24A and a pair of plates 24B that are integrally formed at both ends in the axial direction of the connecting shaft 24A and extend in parallel to each other outward in the radial direction. ing. The connecting shaft 24A of the lock plate 24 is housed in the bottom of the notch 20 of the spool 16 so as to be rotatable about the axis, and the pair of plates 24B is a pair of recesses 22 formed at both ends of the spool 16 in the axial direction. (Contained). Furthermore, locking teeth 24C that can be engaged with the ratchet teeth 14A of the internal tooth ratchet 14 described above are formed at the tip of each plate 24B.

  When the pair of plates 24B are completely accommodated in the pair of recesses 22, the lock teeth 24C are held at positions separated from the ratchet teeth 14A (hereinafter, this position is referred to as "non-engagement position"). (See FIG. 5). On the other hand, the connecting shaft 24A of the lock plate 24 swings around the bottom of the notch 20, and the pair of plates 24B comes out of the pair of recesses 22, whereby the lock teeth 24C are engaged with the ratchet teeth 14A ( (See FIG. 6).

  As shown in FIGS. 1, 3, and 4, a V gear 26 is disposed outside the one side portion 12 </ b> A of the frame 12. The V gear 26 is made of resin and is formed in a substantially disc shape having a diameter larger than the outer diameter of the end of the spool 16. A cylindrical boss 26 </ b> A having a pair of resin claws on the inner peripheral surface is formed at the axial center of the V gear 26. By inserting the rotating shaft 16B of the spool 16 into the boss 26A, the V gear 26 is coaxially and rotatably attached to one end of the spool 16 in the axial direction.

  Further, a substantially inverted S-shaped guide hole 28 is formed at a predetermined position on the outer peripheral side of the V gear 26. A guide pin 30 (see FIGS. 5 and 6) erected from one plate 24B of the lock plate 24 is inserted into the guide hole 28. As a result, the V gear 26 can be rotated relative to the spool 16 within a predetermined rotation angle range. When relative rotation occurs between the two, the guide hole 28 causes the guide pin 30 to move from the inside to the outside. The lock teeth 24C of the lock plate 24 are guided to a position where the inner teeth ratchet 14 of the frame 12 can engage with the ratchet teeth 14A.

  Further, a support protrusion 32 (see FIGS. 1, 5, and 6) is erected on the surface of the V gear 26 on the spool 16 side in a direction opposite to the boss 26A. The tip of the support protrusion 32 is inserted into a recess 34 formed at one end of the spool 16 in the axial direction. In this state, the torsion coil spring 36 (element grasped as “biasing means” in a broad sense) ) Is locked. The coil portion of the torsion coil spring 36 is disposed in a state of being wound around the rotation shaft 16B of the spool 16, and the other end portion is locked to one end portion in the axial direction of the spool 16. As a result, the V gear 26 is held by the spool 16 by the biasing force of the torsion coil spring 36, and is normally restricted from moving relative to the spool 16 along the circumferential direction and the axial direction. For this reason, when the spool 16 rotates, the V gear 26 rotates following the spool 16.

  Further, around the boss 26A of the V gear 26, a pair of locking portions 38 are erected in parallel with the boss 26A. The locking portion 38 is formed in an arc shape coaxial with the boss 26A in a plan view, and is formed at two locations that are symmetrical with respect to the boss 26A. A small-diameter columnar pawl shaft 40 is erected on the same side surface of the V gear 26. The pawl shaft 40 is formed at a position that is substantially symmetrical with the guide hole 28 described above with the boss 26A interposed therebetween, and is a portion that serves as a support shaft of the pawl 62 described later.

  As shown in FIGS. 3 and 4, in the vicinity of the pawl shaft 40, a pawl locking portion 42 is formed in an arc shape concentric with the pawl shaft 40 in a side view and has a resin claw formed at the tip. Are integrally formed. Further, a pawl stopper 44 corresponding to the shape of a pawl 62 described later is integrally formed in the vicinity of the pawl shaft 40. Furthermore, an elongated spring hole 46 is formed in the vicinity of the pawl shaft 40 in the V gear 26. A spring receiving portion 48 having a substantially cylindrical projection is integrally formed at one end of the spring hole 46.

  Further, the outer periphery of the V gear 26 is integrally formed with external teeth 50 that can be engaged with an engaging portion 82B of a sensor lever 82 of a V sensor 76 described later.

  As shown in FIGS. 1, 3, and 4, a resin inertia plate 52 is coaxially disposed outside the V gear 26. The inertia plate 52 has a substantially disc shape with two outer peripheral portions cut out, and a shaft support hole (circular hole) 54 is formed in the axial center portion thereof. Further, a pair of arc-shaped locking holes 58 are formed on the outer side of the shaft support hole 54 at positions opposed to each other in the radial direction. The boss 26A of the V gear 26 is inserted into the shaft support hole 54, and the pair of locking portions 38 of the V gear 26 are inserted into the pair of locking holes 58, whereby the pair of locking portions 38 are elastic. The inertia plate 52 is coaxially and integrally attached to the V gear 26. Further, the circumferential length (arc length) of the locking hole 58 is set longer than the circumferential length (arc length) of the locking portion 38, and the arc length (circumferential angle) in the state after assembly. The inertia plate 52 can rotate relative to the V gear 26 in the webbing take-up rotation direction (direction B) within the range of the difference between the two. Further, a linear engagement protrusion 60 is integrally formed on the notch side end surface of the inertia plate 52.

  A pawl 62 is pivotally supported on the pawl shaft 40 of the V gear 26 described above. The pawl 62 includes a cylindrical support shaft portion 62A that is supported by the pawl shaft 40, an arm portion 62B that extends from the support shaft portion 62A and has a claw formed on the side surface of the tip end, and a lower portion of the support shaft portion 62A. The locking piece 62C is formed on the outer periphery, and the spring receiving portion 62D is projected from the lower edge support shaft side of the arm portion 62B.

  In a state where the support shaft portion 62A is inserted into the pawl shaft 40, the locking piece 62C is locked to the pawl locking portion 38 of the V gear 26, and is prevented from being pulled out in the axial direction. Further, one end of a compression coil spring 64, which is grasped as “biasing means” in a broad sense, is inserted and locked in the spring receiving portion 62D. The other end portion of the compression coil spring 64 is inserted and locked to the spring receiving portion 48 of the V gear 26 described above, and is accommodated in a spring hole 46 formed in the V gear 26 in a compressed state. Accordingly, the compression coil spring 64 urges the pawl 62 to rotate clockwise around the pawl shaft 40. Further, a small projection 66 that can be brought into contact with the pawl stopper 44 formed on the V gear 26 is integrally formed at the end of the locking piece 62 </ b> C of the pawl 62, and is applied by the urging force of the compression coil spring 64. The pawl 62 serves as a stopper when the pawl 62 rotates around the pawl shaft 40 in the clockwise direction. As a result, the pawl 62 normally rotates (revolves around the rotating shaft 16B) integrally with the V gear 26 without swinging.

  On the other hand, when the pawl 62 rotates counterclockwise around the pawl shaft 40 against the urging force of the compression coil spring 64, the arm portion 62B contacts the side surface of the pawl stopper 44 and further swings. It comes to stop. Thereby, a range (rotation angle) in which the pawl 62 can swing is defined.

  In addition, a resin sensor holder 68 formed in a flat cup shape having a wall portion 68A facing the side portion 12A is fixed to the outside of the one side portion 12A of the frame 12. Inside the sensor holder 68, a WSIR gear 132 as a “rotating body” to be described later is disposed. When the sensor holder 68 is assembled, the WSIR gear 132 is formed on the inner peripheral surface of the WSIR gear 132. The tip of the arm portion 62B of the pawl 62 is opposed to the internal tooth 134. When the pawl 62 swings around the pawl shaft 40 against the urging force of the compression coil spring 64 by the inertia plate 52 when the webbing 18 is suddenly pulled out, the distal end portion of the arm portion 62B of the pawl 62 is It is adapted to be engaged with the internal teeth 134.

  In the above configuration, the inertia plate 52, the pawl 62, the compression coil spring 64, and the internal teeth 134 of the WSIR gear 132 serve as the W sensor 72 that constitutes the WSIR of the lock mechanism.

  Furthermore, a hollow, substantially rectangular parallelepiped holder portion 74 is integrally formed at the outer peripheral lower end portion of the sensor holder 68 described above. The holder portion 74 accommodates a V sensor (acceleration sensor) 76. In FIG. 1, the illustration of the V sensor 76 is omitted.

  As shown in FIGS. 3 and 4, the V sensor 76 includes a housing 78 that is formed in an approximately L shape in a side view and has a concave rolling surface 78 </ b> A formed at the center of the bottom. The housing 78 is attached to the holder portion 74 from the side, and a ball 80 is placed on the rolling surface 78A. Further, a sensor lever 82 is pivotally supported at the upper end of the housing 78 so as to be swingable. The sensor lever 82 includes a support shaft 82A that is pivotally supported on the upper end portion of the housing 78, and an end portion that is formed in a substantially L shape in a plan view and is disposed substantially parallel to the support shaft 82A in the assembled state. 26, an engaging portion 82B that can be engaged with the external teeth 50, and a contact portion 82C that connects the support shaft 82A and the engaging portion 82B and is formed in a dish shape. The contact portion 82 </ b> C is placed on the ball 80 by its own weight, and in this state, the engagement portion 82 </ b> B is held at a non-engagement position separated from the external teeth 50 of the V gear 26. On the other hand, when the vehicle suddenly decelerates, the ball 80 rolls on the rolling surface 78A, so that the sensor lever 82 is swung around the support shaft 82A, whereby the engaging portion 82B is moved to the external tooth 50 of the V gear 26. It becomes the structure engaged.

  Next, a switching mechanism between ELR (emergency locking retractor; emergency locking retractor) and ALR (automatic locking retractor; automatic locking retractor) will be described with reference to FIGS. .

  As described above, the small-diameter shaft 16C is coaxially formed on the rotating shaft 16B of the spool 16, and the small-diameter shaft 16C is pivotally supported by the bearing hole 68B formed in the wall portion 68A of the sensor holder 68. The pinion 100 made of resin is fitted (fitted) to the tip of the small diameter shaft 16C in a state in which relative rotation is impossible.

  A sensor cover (not shown) fixed to the sensor holder 68 and the frame 12 is provided outside the sensor holder 68 described above (on the side opposite to the side portion 12A). A pin (not shown) is erected on the inner side of the sensor cover (on the wall portion 68A side). A two-stage resin made of a large-diameter gear 102A and a small-diameter gear 102B are coaxially and integrally formed on the pin. A gear 102 is rotatably supported. In a state where the sensor holder 68 is attached to the side portion 12 </ b> A of the frame 12, the large-diameter gear 102 </ b> A meshes with the pinion 100 disposed in a penetrating manner in the shaft center portion of the sensor holder 68. Accordingly, the rotation of the spool 16 is decelerated in the process of being input from the pinion 100 to the large diameter gear 102A.

  A substantially disc-shaped first cam plate 104 is loosely fitted on the outer side surface of the sensor holder 68 described above. A circular shaft support hole (not shown) into which the bearing hole 68B of the sensor holder 68 is inserted is formed in the shaft center portion of the first cam plate 104, and an annular groove is formed on the back surface on the outer peripheral side thereof. The annular portion 106 is integrally formed. Further, a ring plate-shaped cam portion 108 is integrally formed on the outer peripheral side of the annular portion 106. In the groove of the annular portion 106, a small-diameter gear 102B of the two-stage gear 102 is disposed in an inserted state. Further, an inner peripheral gear 110 is formed on the outer peripheral surface constituting the groove of the annular portion 106, and the inner peripheral gear 110 is engaged with the small diameter gear 102B. Therefore, when the pinion 100 rotates about its axis, the inner peripheral gear 110 rotates via the large diameter gear 102A and the small diameter gear 102B, and the first cam plate 104 moves in the direction opposite to the rotation direction of the spool 16 (pinion 100). It is the structure which decelerates and rotates.

  Further, the ring plate-shaped cam portion 108 of the first cam plate 104 extends outward in the radial direction over a substantially half circumference. Therefore, the cam portion 108 is provided with a small diameter portion 108A and a large diameter portion 108B. Further, a switching protrusion 112 having the circumferential direction as a longitudinal direction is integrally formed at a predetermined position in the circumferential direction of the small diameter portion 108A of the cam portion 108.

  A substantially disc-shaped second cam plate 114 having a smaller diameter than that of the first cam plate 104 is coaxially fitted on the outside of the first cam plate 104 described above. A boss (not shown) that protrudes toward the first cam plate 104 is formed on the back surface side of the axial center portion of the second cam plate 114, and the second cam plate 114 is coaxial with the first cam plate 104. By being fitted onto the sensor holder 68, the tip end of the bearing hole 68B of the sensor holder 68 is elastically locked. The second cam plate 114 is also substantially the same shape as the first cam plate 104, and a small diameter portion 114A and a large diameter portion 114B are formed over a substantially half circumference. Therefore, a pair of steps is formed at the boundary portion between the small diameter portion 114A and the large diameter portion 114B, whereby the first engagement protrusion 116 and the second engagement protrusion are formed at both ends in the circumferential direction of the large diameter portion 114B. 118 is formed. The switching protrusion 112 formed on the small diameter portion 108 </ b> A of the first cam plate 104 described above is positioned on the rotation locus of the first engagement protrusion 116 and the second engagement protrusion 118.

  A lever support 120 is integrally formed at a position opposite to the holder 74 where the V sensor 76 is assembled at the lower end of the sensor holder 68 described above. A support shaft 122 is erected integrally on the upper end side of the lever support portion 120, and a spring locking portion 124 is erected integrally on the lower end side. A resin-made ALR lever 126 is pivotally supported on the support shaft 122 in a swingable manner. The ALR lever 126 is formed at a cylindrical shaft portion 126A inserted into the support shaft 122, an arm portion 126B extending outward from the shaft portion 126A in the radial direction, and a tip of the arm portion 126B. A substantially staircase-shaped interference portion 126C and a claw that extends from the back surface side of the interference portion 126C toward the inside of the sensor holder 68 and that can engage with the external teeth 50 of the V gear 26 are formed at the inner end. And the claw portion 126D.

  A coil portion of a torsion coil spring 128 that is grasped as “biasing means” in a broad sense is wound around the shaft portion 126A of the ALR lever 126. One end of the torsion coil spring 128 is engaged with an engaging projection 130 formed on the back side of the interference portion 126C, and the other end of the torsion coil spring 128 is engaged with the spring engaging portion 124 of the sensor holder 68. It has been stopped. Therefore, the torsion coil spring 128 urges the interference portion 126C of the ALR lever 126 to rotate around the support shaft 122 toward the outer peripheral surface of the second cam plate 114.

[Main part configuration of webbing take-up device 10]
Next, the principal part of the webbing retractor 10 according to the present embodiment will be described with reference to FIGS. 1 and 10 to 16. As shown in FIG. 1, a WSIR gear 132 as a “rotating body” is provided between the inertia plate 52 and the wall 68 </ b> A of the sensor holder 68 described above. The WSIR gear 132 has an axial end portion (the right end portion in FIG. 1) arranged to face the wall portion 68A, and a small-diameter shaft 16C of the spool 16 is inserted into a bearing hole 133 formed in the axial center portion. Is inserted so that it is coaxially and relatively rotatable with respect to the spool 16. As shown in FIG. 13, a flange portion 16D is formed on the small-diameter shaft 16C, and the movement of the WSIR gear 132 to the other side in the axial direction (left side in FIG. 1) is restricted. .

  As shown in FIGS. 10 to 12, an inner tooth 134 is formed on the inner peripheral surface of the WSIR gear 132 so that the distal end portion of the arm portion 62 of the pawl 62 can be engaged. Further, external teeth 136 as “engaging teeth” are formed on the outer peripheral surface of the WSIR gear 132 (that is, the WSIR gear 132 is a member in which a gear is formed on each of the inner and outer peripheral surfaces. ). As shown in FIG. 13, the external tooth 136 has an inclined surface 136 </ b> A at the end opposite to the wall 68 </ b> A. Further, as shown in FIG. 14, the external teeth 136 are formed so that the valley portion is substantially trapezoidal (substantially wedge-shaped) when viewed from the axial direction of the WSIR gear 132.

  On the radially outer side of the WSIR gear 132, another pawl 138 as a “rotation prevention member” is provided. The pawl 138 is inserted into a bearing hole 138 </ b> C (see FIG. 15) formed in the base end (the end on the arrow B direction side) of the support shaft 140 erected on the sensor holder 68. 68 is pivotably supported by the shaft 68, and the tip end portion engages or disengages (contacts and separates) with respect to the WSIR gear 132 by swinging around the support shaft 140. An engaging claw 138A that protrudes toward the WSIR gear 132 is formed at the tip of the pawl 138 (the end on the arrow A direction side). As shown in FIG. 14, the engagement claw 138 </ b> A is formed in a substantially trapezoidal shape (substantially wedge-shaped, that is, a shape corresponding to the external teeth 136 of the WSIR gear 132) when viewed from the axial direction of the WSIR gear 132. Has been.

  The pawl 138 is attached in a direction (arrow G direction) in which the pawl 138 is engaged with the external teeth 136 around the support shaft 140 by an urging force of a torsion spring 141 (which is an element grasped as “urging means” in a broad sense). It is energized. Therefore, normally, the engaging claws 138A of the pawl 138 are fitted into the valleys of the external teeth 136 of the WSIR gear 132 by the urging force of the torsion spring 141, and the pawl 138 moves in the webbing pull-out direction of the WSIR gear 132. Is prevented (as shown in FIG. 10). Moreover, since the engaging claws 138A and the external teeth 136 are both formed in a substantially trapezoidal shape as described above, the WSIR gear is in a state where the engaging claws 138A are fitted in the valley portions of the external teeth 136. The relative displacement (backlash) along the circumferential direction with respect to the pawl 138 of 132 is prevented. Note that the wedge angle θ of the engaging claw 138A shown in FIG. 14 is preferably set to 10 degrees to 20 degrees. By setting in this way, the dissociation property of the engaging claws 138A with respect to the external teeth 136 can be improved.

  As shown in FIG. 15, the pawl 138 has an inclined surface 138B. The inclined surface 138B is an inclined surface of the external tooth 136 in a state where the pawl 138 is engaged with the WSIR gear 132, that is, in a state where the engaging claw 138A is fitted in the valley portion of the external tooth 136 of the WSIR gear 132. 136A (see the two-dot chain line in FIG. 13). Thus, in a state where the inclined surface 138B is in contact with the inclined surface 136A, the external teeth 136 are applied to the one side in the axial direction of the WSIR gear 132 by the urging force of the torsion spring 141 (the right side in FIG. ) (See arrow P in FIG. 13), the WSIR gear 132 is brought into contact with (pressed against) the wall 68A.

  Further, in the webbing take-up device 10, as shown in FIG. 16, the sensor holder 68 has a hole 68C formed at a position facing the pawl 138. The external teeth 136 of the WSIR gear 132 are Although it is configured to be exposed to the pawl 138 side through the hole 68C, when the pawl 138 is engaged with the WSIR gear 132, the end of the pawl 138 on the webbing pull-out direction side (arrow A direction side) is In addition, it comes into contact with the hole edge (contact part 68D) of the hole part 68C. Therefore, when the pawl 138 is engaged with the WSIR gear 132, the pawl 138 is prevented from moving relative to the sensor holder 68 (frame 12) in the webbing pull-out direction.

  Further, in the webbing take-up device 10, when the webbing 18 is completely taken up by the spool 16, the pawl 138 is separated from the external teeth 136 of the WSIR gear 132 against the urging force of the torsion spring 141. It swings in the direction opposite to the arrow G direction (shown in FIG. 12). For this reason, when the webbing 18 is fully wound on the spool 16, the WSIR gear 132 is allowed to rotate (as shown in FIG. 12).

  Such operation control of the pawl 138 can be established using the switching mechanism between ELR and ALR described above. As an example, an inclined wall is previously placed at a predetermined position of the large-diameter portion 108B of the first cam plate 104 (a position where it can interfere with the tip of the engaging claw 138A of the pawl 138 when the webbing 18 is fully wound). Form it. The first cam plate 104 rotates in the webbing pull-out rotation direction when the occupant releases the webbing, and the inclined wall provided on the large-diameter portion 108B of the first cam plate 104 near the fully wound state is the tip of the engaging claw 138A. The pawl 138 may be forcibly pressed in the direction opposite to the arrow G direction against the urging force of the urging means. Such operation control may be performed in relation to the second cam plate 114.

  Next, the operation of the present embodiment will be described.

  In the webbing take-up device 10 configured as described above, normally, the pawl 62 of the W sensor 72 is urged to rotate clockwise around the pawl shaft 60 by the urging force of the compression coil spring 64, and the sensor lever 82 of the V sensor 76. Is held on the ball 80 by its own weight, the W sensor 72 and the V sensor 76 do not operate. Therefore, the spool 16 can freely rotate in both the webbing pull-out rotation direction and the webbing take-up rotation direction with the lock plate 24 stored.

  On the other hand, when the webbing 18 is pulled out suddenly or the vehicle is suddenly decelerated, the W sensor 72 and the V sensor 76 are activated. Hereinafter, the operation of each part will be outlined in this order.

(When W sensor 72 operates)
When the webbing 18 is pulled out rapidly, the spool 16 and the V gear 26 are rotated at high speed in the webbing drawing rotation direction (direction A). At this time, since the inertia plate 52 cannot follow the V gear 26, an inertia delay occurs in the inertia plate 52 against the urging force of the compression coil spring 64, and the inertia plate 52 is relative to the V gear 26. Rotate in the webbing take-up rotation direction (direction B). When the inertial plate 52 rotates in the direction B relative to the V gear 26, the pawl 62 with which the engagement protrusion 60 of the inertial plate 52 is in contact (engaged) is pressed and swayed in the direction B, and the sensor holder. 68 is engaged with the internal teeth 134 of the WSIR gear 132 fixedly held through the pawl 138, and the rotation of the V gear 26 in the direction A is prevented (the state shown in FIG. 4).

  When rotation of the V gear 26 in the direction A is prevented, relative rotation is continuously generated with the spool 16 on which the webbing tensile force is applied, so that the guide pin 30 is on the outer end side of the guide hole 28 of the V gear 26. As a result, the lock teeth 24C of the lock plate 24 are guided to a position where the internal teeth ratchet 14 can be engaged with the ratchet teeth 14A, and the tip of the lock teeth 24C is in the lock standby state, that is, the internal teeth ratchet 14 is engaged. The ratchet teeth 14A are engaged with the tooth tips.

  When the claw tips of the pair of lock teeth 24C of the lock plate 24 are guided to positions where they can engage with the tip of the ratchet teeth 14A of the pair of internal teeth ratchet 14, the spool 16 rotates in the further direction A. As a result, the ratchet teeth 14A are guided, and the tips of the lock teeth 24C reach the roots of the ratchet teeth 14A. As a result, the lock plate 24 is securely locked by the internal tooth ratchet 14, the rotation of the spool 16 in the webbing drawing rotation direction (direction A) is prevented, and the drawing of the webbing 18 beyond that is restricted. That is, the spool 16 (lock plate 24) is self-locked after guiding the lock teeth 24C to a position where the lock teeth 24C can be engaged with the internal tooth ratchet 14.

  On the other hand, when the tension applied to the webbing 18 decreases after the webbing 18 is prevented from being pulled out, the lock plate 24 and the internal tooth ratchet 14 are rotated in the webbing take-up rotation direction (direction B) by a predetermined angle ( When the webbing 18 is wound up by a predetermined amount), the engaged state is released. That is, when the spool 16 is rotated in the direction B, the lock plate 24 is pressed by the notch 20 of the spool 16 on the connecting shaft 24A, so that the lock teeth 24C are separated from the internal tooth ratchet 14, respectively, and the torsion coil spring 36 Return to the initial position together with the V gear 26 by the urging force. The winding of the webbing 18 after the tension acting on the webbing 18 is reduced is performed by a spring spring (not shown) connected to the rotating shaft 16A of the spool 16.

(When V sensor 76 operates)
When the vehicle suddenly decelerates, the ball 80 of the V sensor 76 rolls on the rolling surface 78A of the housing 78 due to the inertial force that accompanies this, and the contact portion of the sensor lever 82 that is placed in contact with the ball 80. 82C is swung upward. Therefore, the engaging portion 82B is swung counterclockwise around the support shaft 82A and engaged with the external teeth 50 of the V gear 26. As a result, rotation of the V gear 26 in the webbing pull-out direction is prevented, so that relative rotation occurs between the V gear 26 and the spool 16. Since the subsequent operation is the same as that of the W sensor 72 described above, a description thereof will be omitted.

(Switch between ELR and ALR)
Next, switching operation between ELR and ALR will be described. The state shown in FIG. 7 is a state where the webbing 18 is fully wound. In this state, since the outer peripheral edge of the large-diameter portion 108B of the first cam plate 104 is located immediately above the engaging portion 82B of the sensor lever 82 constituting the V sensor 76, the sensor lever 82 can swing. Can not. That is, the ELR is inactive. On the other hand, at this time, since the second cam plate 114 is positioned at the illustrated position with respect to the first cam plate 104, the interference portion 126 </ b> C of the ALR lever 126 resists the biasing force of the torsion coil spring 128. It rides on one engaging protrusion 116. Therefore, the claw portion 126 </ b> D on the back side of the first engagement protrusion 116 does not engage with the external tooth 50 of the V gear 26. Therefore, the spool 16 can be rotated in the webbing pull-out direction, and the occupant can pull out the webbing 16 for wearing.

  Next, when the occupant pulls out the webbing 18 from the spool 16 to mount the webbing 18 from the state shown in FIG. 7, the pinion 100 rotates in the webbing pull-out rotation direction (direction A). For this reason, the large-diameter gear 102A of the two-stage gear 102 meshing with the pinion 100 rotates in a counterclockwise direction (the direction of arrow E in FIG. 7), and the small-diameter gear 102B also has the same speed in the same direction as the large-diameter gear 102A. Rotate with. When the small-diameter gear 102B rotates counterclockwise, the inner peripheral gear 110 of the first cam plate 104 meshing with the small-diameter gear 102B rotates in the webbing take-up rotation direction (direction B). As a result, the switching projection 112 formed integrally with the first cam plate 104 turns in the direction of arrow F in FIG. 7 to reach the state shown in FIG. In this state, that is, when the occupant is wearing the webbing, the large-diameter portion 108B of the first cam plate 104 is retracted from directly above the sensor lever 82, so that the V sensor 76 is in an operable state. On the other hand, since the second cam plate 114 has not yet rotated at this time point, the interference portion 126C of the ALR lever 126 has ridden on the first engagement protrusion 116, and the non-operating state is maintained. Yes. Therefore, the occupant can draw out and wind up the webbing 18 within a predetermined range by changing the posture after mounting the webbing 18.

  Next, when the child seat is fixed on the vehicle seat, the webbing retractor 10 is switched from the ELR mode to the ALR mode by pulling out the entire webbing 18.

  The case of switching from the full winding state of the webbing 18 shown in FIG. 7 to the ALR mode will be described as an example. When the webbing 18 is pulled out as described above, the switching projection 112 of the first cam plate 104 is accordingly accompanied. Turns in the webbing take-up rotation direction. Then, when the webbing 18 is fully pulled out to the vicinity, the switching projection 112 comes into contact with the end surface of the first engagement projection 116 of the second cam plate 114 as shown in FIG. Further, when the webbing 18 is pulled out, it is pressed by the switching projection 112 and the second cam plate 114 starts to rotate in the webbing take-up rotation direction. Then, the interference portion 126C of the ALR lever 126 rides on the switching projection 112 from the first engagement projection 116 of the second cam plate 114, and when the switching projection 112 exceeds the interference portion 126C, the torsion coil spring 128 is attached. The interference portion 126C is brought into contact with the outer peripheral surface of the small diameter portion 114A of the second cam plate 114 by the force. As a result, the claw portion 126D of the ALR lever 126 engages with the external tooth 50 of the V gear 26 and locks its rotation in the webbing pull-out direction. That is, the ALR is activated. Further, at this time, the large diameter portion 108B of the first cam plate 104 is again positioned immediately above the engaging portion 82B of the sensor lever 82 of the V sensor 76, so that the ELR is inactivated. If the slack (extra drawer) of the webbing 18 after the child seat is fixed is wound around the spool 16 after the ELR is switched to the ALR in this way, the child seat can be firmly fixed to the vehicle seat.

  Here, when the occupant normally wears the webbing 18, as shown in FIG. 10, the engaging claw 138A of the pawl 138 is engaged with the external teeth 136 of the WSIR gear 132 by the urging force of the urging means. The WSIR gear 132 is held in a state where rotation in the webbing pull-out direction is prevented. Accordingly, if the webbing 18 is suddenly pulled out in this state, the W sensor 72 is activated, and as shown in FIG. 11, inertial delay occurs in the inertial plate 52, and the pawl 62 becomes WSIR. The internal gear 134 engages with the internal teeth 134, relative rotation occurs between the V gear 26 and the spool 16, and the lock plate 24 is engaged with the internal gear ratchet 14.

  On the other hand, when the occupant releases the webbing wearing state and releases the webbing 18, the webbing 18 is entirely wound around the spool 16 by the urging force of the mainspring spring. At this time, the spool 16 stops rotating in the webbing take-up direction when all the webbing 18 is taken up, but the inertia plate 52 arranged coaxially with the V gear 26 is provided so as to be relatively rotatable within a predetermined range. Therefore, even after the spool 16 stops rotating in the webbing take-up direction, the inertia plate 52 tries to rotate in the webbing take-up rotation direction. When this state progresses, as shown in FIG. 12, the arm 62B of the pawl 62 is pressed by the engaging projection 60 of the inertia plate 52, and the pawl 62 rotates around the pawl shaft 40 against the urging force of the compression coil spring 64. The tip of the arm portion 62B is engaged with the internal teeth 134 of the WSIR gear 132.

  However, in the webbing take-up device 10, when the entire amount of the webbing 18 is taken up, the pawl 138 is moved around the support shaft 140 in the direction opposite to the arrow G direction using the movement of the large-diameter portion 108 B of the first cam plate 104. The engaging claw 138A of the pawl 138 is disengaged from the external tooth 136 of the WSIR gear 132 by pressing. Therefore, the WSIR gear 132 can be rotated in both the webbing take-up rotation direction and the webbing pull-out rotation direction, and is rotated in the acting direction of the load input from the tip end portion of the arm portion 62B of the pawl 62. As a result, the engagement state between the distal end portion of the arm portion 62B and the internal teeth 134 of the WSIR gear 132 is released. As a result, according to the webbing take-up device 10 according to the present embodiment, it is possible to suppress or prevent the so-called end lock from occurring in the so-called WSIR.

  Further, in the webbing retractor 10 according to the present embodiment, when the pawl 138 is engaged with the WSIR gear 132, the inclined surface 138B of the pawl 138 abuts on the inclined surface 136A of the external tooth 136, so that WSIR Due to the urging force of the torsion spring 141, the component gear 132 is applied with a component force directed toward one end in the axial direction, and the WSIR gear 132 is brought into contact with (pressed against) the wall portion 68A of the sensor holder 68. As a result, the WSIR gear 132 is restrained so as not to move relative to the sensor holder 68, that is, the frame 12 in the axial direction.

  Therefore, for example, even when the dimensional accuracy between the bearing hole 133 of the WSIR gear 132 and the small diameter shaft 16C of the spool 16 is not high, and the outer peripheral portion of the WSIR gear 132 rattles in the axial direction with respect to the spool 16, Relative movement of the WSIR gear 132 in the axial direction relative to the frame 12 in the engaged state can be suppressed. Accordingly, the relative movement of the WSIR gear 132 in the axial direction with respect to the V gear 26 can also be suppressed, and the relative positional relationship between the WSIR pawl 62 supported by the V gear 26 and the internal teeth 134 of the WSIR gear 132. Can be maintained in a good state.

  In the webbing retractor 10 according to the present embodiment, when the pawl 138 is engaged with the WSIR gear 132, the contact portion 68D provided on the sensor holder 68 is located at the end of the pawl 138 on the webbing withdrawal direction side. The pawl 138 is prevented from moving relative to the sensor holder 68 (frame 12) in the webbing pull-out direction. Therefore, for example, even if there is play between the bearing hole 138C of the pawl 138 and the support shaft 140, the pawl 138 and the WSIR gear 132 move relative to the frame 12 in the webbing pull-out direction due to the play (play). There is nothing. Thereby, the positioning accuracy of the WSIR gear 132 with respect to the frame 12 in a state where the pawl 138 is engaged with the WSIR gear 132 can be improved.

  Further, in the webbing retractor 10 according to the present embodiment, when the pawl 138 is engaged with the WSIR gear 132, the engaging pawl 138A of the pawl 138 is fitted into the valley portion of the external teeth 136 of the WSIR gear 132. The relative displacement of the WSIR gear 132 in the circumferential direction with respect to the pawl 138 is prevented. Therefore, the positioning accuracy of the WSIR gear 132 with respect to the frame 12 is not deteriorated by the circumferential displacement (backlash) of the WSIR gear 132 with respect to the pawl 138 in the engaged state.

  In the webbing take-up device 10 according to the above-described embodiment, the lock mechanism using the U-shaped lock plate 24 in a plan view is employed. However, the present invention is not limited to this, and various lock mechanisms can be employed. .

  In the webbing retractor 10 according to the above embodiment, the pawl 138 is detached from the external teeth 136 of the WSIR gear 132 by using a switching mechanism between ELR and ALR. By detecting the winding diameter of the webbing 18 on the spool 16, the entire winding state of the webbing 18 may be grasped, and the WSIR gear 132 may be unlocked, or the rotational speed of the spool 16 may be detected. As a result, the entire winding state of the webbing 18 may be grasped, and the WSIR gear 132 may be unlocked.

  Further, in the webbing retractor 10 according to the above embodiment, the configuration is adopted in which the inner teeth 134 are formed on the inner peripheral surface of the WSIR gear 132 and the outer teeth 136 are formed on the outer peripheral surface. The WSIR gear 132 is fixedly held when the webbing 18 is not fully wound, and the WSIR gear 132 can be rotated when the entire amount is wound. All are applicable.

  Furthermore, in the webbing take-up device 10 according to the above-described embodiment, the pawl 138 swings around the support shaft 140 with respect to the sensor holder 68, so that the engaging claw 138 is engaged with the external teeth 136 of the WSIR gear 132. For example, the pawl 138 slides with respect to the sensor holder 68 so that the engaging claw 138 is engaged with and disengaged from the external teeth 136 of the WSIR gear 132. Also good.

  Further, in the webbing retractor 10 according to the above embodiment, the engaging claw 138 of the pawl 138 is formed in a trapezoidal shape when viewed from the axial direction of the WSIR gear 132. The engaging claws 138A may be formed in a quadrangular or triangular shape when viewed from the axial direction of the WSIR gear 132.

It is a schematic sectional drawing which shows the whole structure of the webbing winding apparatus which concerns on embodiment of this invention. It is a perspective view which isolate | separates and shows the spool and lock plate which are shown by FIG. It is a side view which shows W sensor (non-operation state) and V sensor of the webbing winding device concerning an embodiment of the invention. It is a side view which shows W sensor (operation state) and V sensor of the webbing take-up device according to the embodiment of the present invention. It is a side view which shows the lock mechanism (non-operation state) of the webbing winding device concerning an embodiment of the invention. It is a side view which shows the locking mechanism (operation state) of the webbing take-up device according to the embodiment of the present invention. It is a side view which shows the switching mechanism (ELR is non-operation state and ALR is also non-operation state) of the ELR and ALR of the webbing take-up device according to the embodiment of the present invention. It is a side view which shows the switching mechanism (ALR is a non-operation state in an ELR operation state) of ELR and ALR of a webbing take-up device according to an embodiment of the present invention. It is a side view which shows the switching mechanism (ALR is an operation state in an ELR non-operation state) of ELR and ALR of the webbing take-up device according to the embodiment of the present invention. It is a side view which shows the state (normal state in a locked state) of the pawl which concerns on the principal part of this Embodiment regarding the relationship between the switching mechanism of ELR and ALR of the webbing take-up device according to the embodiment of the present invention. The side view which shows the state of the pawl which concerns on the principal part of this Embodiment in the relationship between the ELR and ALR switching mechanism of the webbing take-up device according to the embodiment of the present invention (when the webbing is suddenly pulled out in the locked state). It is. Side view showing a state of a pawl according to the main part of the present embodiment (when the webbing is fully wound in an unlocked state) in relation to the ELR and ALR switching mechanism of the webbing retractor according to the embodiment of the present invention. FIG. It is sectional drawing which shows the structure of the peripheral member containing the gear for WSIR of the webbing winding apparatus which concerns on embodiment of this invention. It is a top view which shows the state which the engaging claw of the pawl fitted in the external tooth of the WSIR gear of the webbing take-up device according to the embodiment of the present invention. It is a perspective view which shows the structure of the pawl of the webbing winding device concerning an embodiment of the invention. It is a side view which shows the structure of the peripheral member containing the sensor holder of the webbing winding apparatus which concerns on embodiment of this invention.

Explanation of symbols

10 Webbing take-up device 12 Frame 14 Internal tooth ratchet (lock mechanism)
16 Spool (winding shaft)
18 Webbing 24 Lock plate (lock mechanism)
72 W sensor (lock mechanism)
132 WSIR gear (rotating body)
136 External teeth (engaging teeth)
136A Inclined surface 138 Paul (rotation prevention member)
138A engaging claw 138B inclined surface

Claims (4)

Frame,
A winding shaft that is pivotally supported by the frame and on which a webbing for restraining an occupant is wound;
A lock mechanism that locks rotation of the winding shaft in the webbing pull-out direction when the webbing is suddenly pulled out;
A rotating body that is rotatably provided and enables the lock mechanism in a state where the rotation of the lock mechanism is inhibited, and disables the lock mechanism in a state where the rotation of the lock mechanism is allowed;
It is supported by the frame and normally engages with the rotating body to prevent the rotating body from rotating, and when the webbing is completely wound on the winding shaft, it is detached from the rotating body and A rotation prevention member for releasing the prevention;
Restraining means for restraining the rotating body from being relatively movable in the axial direction with respect to the frame in a state where the rotation preventing member is engaged with the rotating body;
A webbing take-up device comprising:   The restraining means is provided on at least one of the wall portion, which is attached to the frame and faces one end in the axial direction of the rotating body, and the rotating body and the rotation preventing member, and the rotation preventing member is engaged with the rotating body. The webbing take-up device according to claim 1, further comprising: a surface that applies a force directed toward the one end side in the axial direction to the rotating body in a combined state, and causes the rotating body to contact the wall portion. Frame,
A winding shaft that is pivotally supported by the frame and on which a webbing for restraining an occupant is wound;
A lock mechanism that locks rotation of the winding shaft in the webbing pull-out direction when the webbing is suddenly pulled out;
Coaxially and relatively rotatable with respect to the take-up shaft, the lock mechanism can be operated in a state where its rotation is blocked, and the lock mechanism is operated in a state where its rotation is allowed. A rotating body to disable,
The frame is supported by the frame and normally engages with the rotating body to prevent the rotating body from rotating, and when the webbing is completely wound on the winding shaft, the webbing is detached from the rotating body and A rotation prevention member for releasing the prevention;
An abutting portion attached to the frame and abutting against an end portion of the rotation preventing member on the webbing pull-out direction side in a state where the rotation preventing member is engaged with the rotating body;
A webbing take-up device comprising:   The rotating body has engaging teeth, and the rotation preventing member is fitted in the valley portion of the engaging teeth in a state of being engaged with the rotating body, and is arranged in a circumferential direction of the rotating body with respect to the rotation preventing member. The webbing take-up device according to any one of claims 1 to 3, further comprising an engaging claw that prevents relative displacement along the axis.

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