JP2011218946A - Webbing winding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a webbing winding device which can prevent or suppress the occurrence of the operating noise resulting from the repetition of the mechanical connection and disconnection between a drive means and a spool and which can continuously maintain and release the operating state of a torque limiter.SOLUTION: While the engagement of a pawl 120 and a driven gear 130 is forcibly eliminated, the engagement of the pawl 120 with the driven gear 130 is restrained by the interference piece 172 of a pawl stopper 160. Since the contact part 168 of the pawl stopper 160 is pressed by the pressing part 170 of a ring gear 102, and the pawl stopper 160 is rotated together with the ring gear 102 when the ring gear 102 is rotated in the winding direction in this state, the engagement of the pawl 120 with the driven gear 130 is maintained. When the ring gear 102 is rotated in the drawing direction in this state, the engagement of the pawl with the driven gear by the interference piece 172 is eliminated, and recovered to the state of engagement of the claw part 128 of the pawl 120 with the driven gear 130.

Description

  The present invention relates to a webbing take-up device that winds and stores a webbing belt that restrains the body of an occupant on a spool, and more particularly, to a webbing take-up device that can rotate a spool with a driving force of a driving means such as a motor. .

  In the webbing take-up device disclosed in the third embodiment of Patent Document 1 below, a clutch is interposed between a motor and a spool (referred to as a spindle in Patent Document 1). A torque limiter is interposed between the two. When the motor is activated and the driving force of the motor is transmitted to the clutch via the torque limiter, the clutch pole engages with the latch plate to connect the motor and the spool, and the driving force of the motor is transmitted to the spool and the spool is wound up. Rotate in the direction. As the spool rotates in the winding direction in this manner, the slight slack of the webbing belt attached to the occupant's body, so-called “slack”, is eliminated.

  Further, in this webbing take-up device, when the pretensioner is operated and the high-speed rotational force in the take-up direction applied to the spool is transmitted to the clutch, the pole is separated from the latch plate. As a result, the connection between the motor and the spool by the clutch is released, and the fixing pin holding the rotor cam is sheared by the rotational force of the pole. As a result, both the pole and the rotor cam are held by the biasing force of the return spring, and the connected state of the motor and the spool is maintained.

International Patent Application Publication No. 2006-123750

  In such a configuration, the driving force of the motor transmitted to the spool in a state where the pretensioner is not operated exceeds a predetermined magnitude, and the torque difference between the large diameter side gear and the small diameter side gear constituting the torque limiter is reduced. When the predetermined size is exceeded, the large-diameter side gear rotates relative to the small-diameter side gear. Due to this relative rotation, the limit spring is elastically deformed so that the protruding portion of the limit spring slides out of the locking surface on the inner peripheral surface of the large-diameter side gear and is large with respect to the locking surface that has been engaged so far. It engages with another locking surface adjacent on the side opposite to the rotation direction of the radial gear.

  Thus, when the protrusion of the limit spring engages the locking surface with its elastic force, a hitting sound is generated such that the protrusion hits the locking surface, and the protrusion of the limit spring against the locking surface is generated. The above-described hitting sound is generated intermittently by repeating the separation and engagement of the portion.

  On the other hand, if the cancellation of the connection between the motor and the spool is maintained on the spool side with respect to the torque limiter, such a hitting sound does not occur. However, in the above configuration, the connection between the motor and the spool is released in the clutch, and the maintenance of the connection between the motor and the spool is accompanied by shearing of the fixing pin. In this way, if the fixing pin is sheared in order to maintain the connection between the motor and the spool, the clutch can be reused, and hence the drive force transmission mechanism from the motor to the spool cannot be reused. With this configuration, it is not possible to maintain the disconnection between the motor and the spool when the pretensioner is not operating.

  In consideration of the above facts, the present invention can prevent or suppress the generation of operation noise caused by repeated mechanical connection between the drive means and the spool and the release thereof, and the operation state of the torque limiter can be continuously reduced. It is an object to obtain a webbing take-up device that can be maintained and released.

  The webbing take-up device according to the first aspect of the present invention includes a driving unit capable of outputting a driving force for forward rotation and reverse rotation, and a longitudinal base end side of a long webbing belt. A spool that rotates in the winding direction and stores the webbing belt by winding and storing the webbing belt from the longitudinal base end side, and a normal rotation driving force output from the driving means is transmitted; The drive means and the spool are interposed, and the drive means and the spool are mechanically connected by outputting the forward driving force from the drive means, and the drive means and the spool are coupled. A clutch for releasing the mechanical connection between the drive means and the spool by transmitting the forward drive force to the drive means and the reverse drive force from the drive means, and the drive means and the clutch. The forward drive force is transmitted to the clutch by mechanically connecting the drive means and the clutch, and is not less than a predetermined size transmitted from the clutch side and the winding. The rotational force in the pulling direction opposite to the take-off direction is transmitted to release the mechanical connection between the driving means and the clutch to maintain the released state, and further output from the driving means in the released state. And a torque limiter that mechanically connects the driving means and the clutch by transmitting the reverse driving force.

  In the webbing retractor according to the first aspect of the present invention, when the normal rotation driving force from the driving means such as a motor is transmitted to the torque limiter, the torque limiter is rotated to transmit this normal rotation driving force to the clutch. . When the forward drive force is transmitted to the clutch, the clutch mechanically connects the torque limiter and the spool, and transmits the forward drive force transmitted to the clutch via the torque limiter.

  Thus, when the spool rotates in the winding direction, the webbing belt is wound around the spool. For this reason, for example, if the driving means is rotated forward when the distance to the obstacle ahead of the vehicle is less than a predetermined value, the webbing belt attached to the occupant's body is slightly slackened, so-called “slack”. "Can be eliminated, and the binding force by the webbing belt can be increased.

  On the other hand, for example, when the webbing belt is pulled, the spool rotates in a drawing direction opposite to the winding direction. As described above, when the torque limiter and the spool are mechanically connected by the clutch and the pulling direction rotational force is applied to the spool, the spool pulling direction rotational force is applied to the spool via the clutch. Is transmitted to the torque limiter.

  Here, if the pulling direction rotational force transmitted from the spool to the torque limiter is greater than or equal to a predetermined magnitude, the torque limiter is actuated to release the mechanical connection between the clutch and the drive means by the torque limiter, and The torque limiter maintains this released state. Thereby, even if the rotational force in the pull-out direction of the spool is transmitted to the torque limiter via the clutch, the torque limiter rotates without transmitting the rotational force in the pull-out direction to the driving means. For this reason, the excessive load resulting from the rotational force of the drawing direction more than the said predetermined | prescribed magnitude | size is not applied to the member (for example, clutch) which transmits rotational force between a spool and a torque limiter.

  In addition, since the torque limiter according to the present invention can maintain such a state where the mechanical connection between the drive means and the spool is released, the torque limiter performs the mechanical connection between the drive means and the spool and the release thereof. Generation of operating noise due to repetition can be prevented or suppressed.

  In addition, when the forward drive force is output from the drive unit as described above and the reverse drive force is output from the drive unit, the torque limiter mechanically connects the drive unit and the clutch (the torque limiter is already connected). If the driving means and the spool are mechanically connected, this connected state is continued), and the reverse driving force is transmitted to the clutch. When the reverse rotation driving force is transmitted to the clutch, the mechanical connection between the driving means by the clutch and the spool is released. Thus, the mechanical connection between the drive means and the spool is released, so that the rotational force of the spool is not transmitted to the drive means.

  Next, when the normal rotation driving force is output from the driving means from this state and this normal rotation driving force is transmitted to the clutch via the torque limiter, the clutch mechanically connects the torque limiter and the spool again, and this normal rotation driving force. Transmit power to the spool. Thereby, the webbing belt can be wound around the spool again by the normal driving force of the driving means.

  Further, the configuration of Patent Document 1 operates when the vehicle is suddenly decelerated, and when a so-called “pretensioner” that forcibly rotates the spool in the winding direction is activated, the clutch is disengaged, so that the pretensioner is activated. The torque limiter will not be activated later. On the other hand, in the present invention, since the connection between the spool and the torque limiter via the clutch is maintained even if the pretensioner is operated, the torque limiter can be operated after the pretensioner is operated.

  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 of the present invention, wherein the webbing take-up device according to the first aspect is interposed between the driving means and the spool and is rotated in the rotational circumferential direction by the forward rotation driving force. A first rotating body that rotates to the other side in the rotational circumferential direction by the reverse driving force, a second rotating body that is directly or indirectly connected to the spool so as to be able to transmit rotation to the spool, and The second rotating body is supported by the first rotating body and rotates together with the first rotating body, and a part of the rotating body is engaged with the second rotating body, and the rotation of the first rotating body is transmitted to the second rotating body and the second rotation is performed. And the engagement with the second rotating body by the pressing force received from the second rotating body as the first rotating body tries to rotate relative to the second rotating body in one circumferential direction. A rotation transmission member that can move in a direction to cancel The urging means for urging the rotation transmitting member in a direction to engage the second rotating body, and the rotation transmission in a direction to cancel the engagement with the second rotating body by interfering with the rotation transmitting member. The rotation transmitting member is held so as to restrict the displacement of the member, and is elastically deformed when the pressing force exceeds a predetermined magnitude, so that the engagement with the second rotating body is canceled. A holding means for allowing the displacement of the rotation transmitting member, and a rotation means that is coaxially rotatable with respect to the first rotating body, and that transmits the rotation to the second rotating body by a pressing force from the second rotating body. Due to the relative rotation of the first rotating body with respect to the second rotating body caused by the disengagement of the member, the contact portion comes into contact with the first rotating body from one side in the rotational circumferential direction of the first rotating body. In contact with and pressed by the first rotating body together with the first rotating body The rotation transmitting member in a direction in which the engagement restricting portion interferes with the rotation transmitting member and engages with the second rotating body at a rotation position where the contact portion contacts the first rotating body while rotating. And the engagement restricting means for restricting the displacement of the torque limiter.

  In the webbing take-up device according to the second aspect of the present invention, the forward driving force from the driving means such as a motor is directly or indirectly input to the first rotating body constituting the torque limiter. When the rotating body rotates in one direction, the rotation transmitting member presses the second rotating body with this rotational force to rotate the second rotating body. When one rotation in the circumferential direction of the first rotating body is transmitted to the second rotating body via the rotation transmitting member and the second rotating body rotates, the rotation of the second rotating body further rotates the spool in the winding direction. Let As a result, the webbing belt is wound around the spool from the longitudinal base end side. For this reason, for example, if the driving means is rotated forward when the distance to the obstacle ahead of the vehicle is less than a predetermined value, the webbing belt attached to the occupant's body is slightly slackened, so-called “slack”. "Can be eliminated, and the binding force by the webbing belt can be increased.

  On the other hand, as described above, the rotation transmitting member that rotates together with the first rotating body presses the second rotating body to rotate the second rotating body, and in this state, the rotation transmitting member is rotated from the second rotating body. Receives pressing force (pressing reaction force). When the rotation transmitting member that rotates in the circumferential direction together with the first rotating body presses the second rotating body, the rotation transmitting member is engaged with the second rotating body by the pressing force (pressing reaction force) from the second rotating body. It tries to displace to the direction to cancel. However, since the displacement of the rotation transmitting member is restricted by the holding means, the rotation of the first rotating body in one direction of the rotation circumferential direction can be reliably transmitted to the second rotating body.

  Here, when the rotation transmitting member and the second rotating body are engaged, a rotational force in the pulling direction is applied to the spool, and when the rotating force in the pulling direction is transmitted to the second rotating body, the rotation transmitting member is in the second state. The pressing force (pressing reaction force) received from the rotating body gradually increases. When the pressing force (pressing reaction force) thus increased exceeds a predetermined magnitude (that is, when the rotational force in the pulling direction of the spool exceeds a predetermined magnitude), the holding means is elastically deformed and the second The rotation transmitting member is displaced in a direction to cancel the engagement with the rotating body. Thereby, the connection between the first rotating body and the second rotating body is released, and even if the first rotating body rotates with the normal driving force of the driving means, this rotation is not transmitted to the second rotating body.

  Further, when the connection between the first rotating body and the second rotating body is released in this way, and the first rotating body further rotates relative to the second rotating body in one of the rotational circumferential directions, the first rotating body is Also relative to the engagement restricting means, it rotates relative to one side in the rotational circumferential direction, whereby the first rotating body comes into contact with the contact portion of the engagement restricting means. Thus, when the first rotating body rotates relative to the engagement restricting means until the first rotating body comes into contact with the contact portion of the engagement restricting means, the engagement restricting portion of the engagement restricting means becomes the rotation transmitting member. It reaches a position where it can interfere with. In this state, even if the rotation transmitting member tries to displace in the direction in which the rotation transmitting member is engaged with the second rotating body by the urging force of the urging means, the rotation transmitting member interferes with the engagement restricting portion of the engagement restricting means, and the second rotation Displacement in the direction of engagement with the body is restricted.

  In addition, in this state, the contact portion of the engagement restricting means is in contact with the first rotating body from one side in the rotational circumferential direction. When the first rotating body rotates in one direction in the rotational circumferential direction, the contact portion is When pressed by the first rotating body, the engagement restricting means rotates in the circumferential direction along with the first rotating body. For this reason, in this state, the relative positional relationship of the engagement restricting portion with respect to the rotation transmitting member does not change. Thereby, the non-engagement state of a rotation transmission member and a 2nd rotary body, ie, the connection cancellation | release state of a 1st rotary body, and a 2nd rotary body is maintained.

  Thus, by maintaining the disengaged state between the first rotating body and the second rotating body, for example, the deformation of the torsion shaft or the like of the force limiter mechanism causes the second rotating body to be engaged with the rotation transmission member. The load necessary to eliminate is not repeatedly superimposed.

  Next, when the rotation of the rotation transmitting member with respect to the second rotating body is released as described above, when the first rotating body rotates to the other side in the rotation circumferential direction by the reverse driving force output from the driving means, the engagement regulation The first rotating body rotates relative to the other side in the rotational circumferential direction. Thereby, the rotation transmission member is engaged with the second rotating body by the urging force of the urging means because the interference by the engagement restricting portion of the engagement restricting means is eliminated. Thus, in the webbing take-up device according to the present invention, as described above, the connection release state between the first rotating body and the second rotating body can be maintained. In this state, the first rotating body is rotated. If it rotates to the other circumferential direction, a 1st rotary body and a 2nd rotary body can be connected again, and rotation of a 1st rotary body can be transmitted to a 2nd rotary body.

  As described above, the webbing take-up device according to the present invention can transmit the rotational force in both the take-up direction and the draw-out direction to the spool, and the torque limiter continuously maintains the operating state, Can be canceled.

1 is an exploded perspective view schematically showing an overall configuration of a webbing take-up device according to an embodiment of the present invention. It is a disassembled perspective view which shows schematically the structure of the principal part of the webbing winding device concerning one embodiment of the present invention. It is a side view of the principal part which shows the state with which the 1st rotary body and the 2nd rotary body are connected by the rotation transmission member. It is a side view corresponding to FIG. 3 which shows the state which the rotation transmission member has elastically deformed the holding | maintenance means, releasing engagement with a 2nd rotary body. FIG. 5 is a side view corresponding to FIG. 4 showing a state in which the engagement between the rotation transmitting member and the second rotating body is released. FIG. 6 is a side view corresponding to FIG. 5 illustrating a state in which the first rotating body has rotated to the other side in the rotational circumferential direction from the state where the rotation transmitting member and the second rotating body are disengaged. It is a side view corresponding to FIG. 6 which shows the state which the rotation transmission member engaged again in 2nd rotation.

<Configuration of the present embodiment>
(Outline of overall configuration of webbing retractor 10)
FIG. 1 is a schematic exploded perspective view showing the overall configuration of a webbing take-up device 10 according to an embodiment of the present invention. First, the outline of the overall configuration of the webbing take-up device 10 will be described with reference to this drawing, and then the configuration of the torque limiter 72, which is the main part of the webbing take-up device 10, will be described.

  As shown in this figure, the webbing retractor 10 includes a frame 12 fixed to a skeleton member or the like constituting a vehicle body or a vehicle seat. The frame 12 includes a pair of flat side walls 14 and 16 that are opposed to each other in the thickness direction, and is formed in a concave shape that is open in the width direction of the side walls 14 and 16 as a whole in plan view. ing. A connecting piece 18 is bridged between the upper end of the side wall 14 and the upper end of the side wall 16, and the connecting piece 18 is fixed to a frame member or the like constituting a vehicle body or a vehicle seat like the main body portion of the frame 12. Is done.

  A spool 20 is provided between the side wall 14 and the side wall 16 of the frame 12. The spool 20 is formed in a substantially cylindrical shape (cylindrical shape), and the axial direction thereof is along the opposing direction of the side wall 14 and the side wall 16. A longitudinal base end side of a webbing belt 22 formed in a long belt shape is locked to the spool 20, and when the spool 20 rotates in one winding direction around its own axis, the webbing belt 22 is From the side, it is wound around the outer periphery of the spool 20 and stored. The webbing belt 22 is drawn from the spool 20 to one side (upward) in the longitudinal direction of the side walls 14 and 16 and passes through a through hole 24 formed in the connecting piece 18.

  On the other hand, a torsion shaft constituting a so-called “force limiter mechanism” is provided inside the spool 20. The torsion shaft is formed in a rod shape whose axial direction is along the axial direction of the spool 20. This torsion shaft is connected to the spool 20 in a state in which it cannot rotate relative to the spool 20 on the side wall 14 side.

  Further, a housing 28 of a lock mechanism 26 is attached to the outside of the side wall 16 (on the side opposite to the side wall 14 of the side wall 16), and the end of the torsion shaft on the side wall 16 side is directly or indirectly housing. 28 is rotatably supported. The housing 28 accommodates components of the lock mechanism 26 including a lock base connected to the torsion shaft in a state in which the torsion shaft cannot rotate relative to the torsion shaft on the side wall 16 side of the torsion shaft.

  The lock mechanism 26 is a so-called “VSIR mechanism” that operates when the vehicle suddenly decelerates, or a so-called “WSIR mechanism” that operates when the spool 20 suddenly rotates in the pulling direction opposite to the winding direction described above. When at least one of the “VSIR mechanism” and the “WSIR mechanism” is operated, the lock pawl constituting the lock mechanism 26 engages with the lock base and restricts the rotation of the lock base in the pull-out direction.

  As described above, since the lock base cannot rotate relative to the torsion shaft and the torsion shaft cannot rotate relative to the spool 20, the rotation of the lock base in the pull-out direction is restricted, so that the spool 20 moves in the pull-out direction. Rotation of the webbing belt 22 is regulated from the spool 20.

  Further, as described above, the torsion shaft is connected to the spool 20 so as not to rotate relative to the spool 20 at one end side (side wall 14 side), and cannot rotate relative to the lock base at the other end side (side wall 16 side). It is connected. For this reason, when the rotational force of the spool 20 in the pulling direction exceeds the mechanical strength of the torsion shaft in a state where the rotation of the lock base in the pulling direction is restricted, the spool is deformed to be twisted in the torsion shaft. 20 rotates in the pull-out direction with respect to the lock base.

  When the vehicle suddenly decelerates, the rotation of the spool 20 in the pull-out direction is allowed by the amount of twist of the torsion shaft in this way, so that the webbing belt 22 can be pulled out from the spool 20 and pulled out from the spool 20. The occupant's body can move to the front side of the vehicle by the length of the webbing belt 22 and a part of the energy of the occupant's body pulling the webbing belt 22 is used for torsional deformation of the torsion shaft and absorbed. The

  Although not shown, a so-called “pretensioner device” is provided outside the side wall 16 (on the side opposite to the side wall 14 of the side wall 16). Since the pretensioner device is already a well-known technique, a detailed description thereof will be omitted, but in brief, the pretensioner device is described above by the pressure of the gas generated by burning the gas generating agent when the vehicle suddenly decelerates. The lock base is forcibly rotated in the winding direction. By operating the pretensioner device, the spool 20 is forcibly rotated in the winding direction and the webbing belt 22 is wound around the spool 20. Let me take it. Thereby, the force with which the webbing belt 22 restrains the occupant's body is increased, and the inertial movement of the occupant's body toward the front side of the vehicle is suppressed.

  On the other hand, a gear housing 40 is attached to the outside of the side wall 14 of the frame 12 (on the side opposite to the side wall 16 of the side wall 14). The gear housing 40 is formed in a box shape that opens toward the side opposite to the side wall 14, and is closed by a cover 42 provided on the opening side. A through hole 44 is formed in the bottom of the gear housing 40, and an adapter 46 is formed in the side wall 14 at the end of the torsion shaft on the side wall 16 side so as not to rotate relative to the torsion shaft. The through hole 48 and the through hole 44 of the gear housing 40 pass through the inside of the gear housing 40.

  The adapter 46 includes a clutch mounting part 50. The outer peripheral shape of the clutch mounting portion 50 is a polygonal shape such as a hexagonal shape or an octagonal shape, or a non-circular shape such as a star shape or a serration shape (in this embodiment, a hexagonal shape). It is located inside the gear housing 40. Further, the adapter 46 includes a shaft portion 52. The shaft portion 52 projects from the clutch mounting portion 50 to the opposite side of the torsion shaft, and is coaxial with the spool 20 when the adapter 46 is mounted on the torsion shaft. The shaft 52 passes through a through hole 54 formed in the cover 42 and protrudes to the outside of the gear housing 40.

  A spring housing 56 is provided on the opposite side of the cover 42 from the gear housing 40, and is supported by the gear housing 40 in the same manner as the cover 42. The shaft portion 52 of the adapter 46 that has passed through the through hole 54 of the cover 42 enters the inside of the spring housing 56 and is rotatably supported by the spring housing 56. A spiral spring as a spool biasing means is accommodated inside the spring housing 56. The end of the spiral spring on the outer side in the spiral direction is directly or indirectly locked to the spring housing 56, and the end on the inner side in the spiral direction is directly or indirectly locked to the shaft portion 52.

  This spiral spring is tightened when the shaft portion 52 rotates in the pull-out direction, and the biasing force that biases the shaft portion 52 in the winding direction increases. As described above, the adapter 46 having the shaft portion 52 cannot rotate relative to the torsion shaft, and the torsion shaft cannot rotate relative to the spool 20, so that the webbing belt 22 is pulled out from the spool 20. When the shaft portion 52 rotates in the pull-out direction together with the spool 20, the urging force of the spiral spring increases, and the urging force can rotate the spool 20 in the winding direction to wind the webbing belt 22 around the spool 20.

  On the other hand, a reduction gear train 60 is accommodated inside the gear housing 40. The reduction gear train 60 includes a clutch 62. The clutch 62 includes a ring-shaped ring gear 68 having one axial end closed by a bottom wall (not shown) and the other axial end closed by a disc-shaped lid 65. The clutch 62 includes a driven rotation unit 63. The driven rotation portion 63 is formed with a fitting hole 64 corresponding to the clutch mounting portion 50 of the adapter 46, and the clutch mounting portion 50 is fitted into the fitting hole 64 so that the driven rotation portion 63 is connected to the adapter 46. And are coaxially connected in a state where relative rotation is impossible.

  Further, the clutch 62 has a ring-shaped external gear with a flat tooth whose one end in the axial direction (the end on the bottom side of the gear housing 40) is closed by a bottom wall (not shown) and the other end in the axial direction is closed by the lid 65. 68. The ring gear 68 is supported by the adapter 46 so as to be rotatable relative to the adapter 46 in a state where the adapter 46 passes through the bottom wall and is coaxial with the adapter 46.

  Inside the ring gear 68, a slider and a clutch pawl (not shown) are accommodated. The slider is guided by a slider guide formed on the bottom wall of the ring gear 68 and is slidable within a predetermined range relative to the ring gear 68 in the rotational circumferential direction of the clutch 62. It is in pressure contact with the inner bottom. For this reason, even if the ring gear 68 is rotated by transmitting the rotational force in the winding direction to the ring gear 68, the slider does not rotate with the ring gear 68 until reaching the end of the slider guide due to friction with the inner bottom portion of the gear housing 40. . As a result, the slider moves relative to the ring gear 68.

  On the other hand, the clutch pawl is rotatably supported by, for example, a shaft portion formed on the bottom wall, and the ring gear 68 rotates in the winding direction so that the slider moves relative to the ring gear 68 as described above. Then, the clutch pawl is rotated by the slider and mechanically connected to the driven rotating portion 63. As a result, the rotation of the ring gear 68 is transmitted to the driven rotating unit 63 to rotate the driven rotating unit 63. Further, when the clutch pawl is mechanically connected to the driven rotating portion 63 in this manner, the ring gear 68 rotates in the pull-out direction, so that when the slider moves relative to the ring gear 68, the slider rotates the clutch pawl. Thus, the mechanical connection between the clutch pawl and the driven rotating portion 63 is released.

  A transmission gear 70 having a flat tooth and a smaller number of teeth than the ring gear 68 is provided on the side of the ring gear 68 of the clutch 62 in the rotational radial direction. The transmission gear 70 is rotatably supported by a shaft 78 formed so as to protrude from the bottom of the gear housing 40 in the same direction as the axial direction of the spool 20. A torque limiter 72 is provided on the side of the transmission gear 70 in the rotational radius direction. Although details of the torque limiter 72 will be described later, the torque limiter 72 has a ring-shaped ring gear 102 as a first rotating body that is a flat tooth with external teeth, and a ring gear 102 having a smaller number of teeth and a smaller diameter than the ring gear 102. And a gear portion 132 (see FIG. 2) of external teeth with flat teeth provided coaxially. The torque limiter 72 is rotatably supported by a shaft 74 formed so as to protrude from the bottom of the gear housing 40 in the same direction as the axial direction of the spool 20, and the gear 132 of the torque limiter meshes with the transmission gear 70. Yes.

  A transmission gear 80 is provided on the side of the ring gear 102 that constitutes the torque limiter 72. The transmission gear 80 is rotatably supported by a shaft 79 that is formed to protrude from the bottom of the gear housing 40 in the same direction as the axial direction of the spool 20. The transmission gear 80 is a two-stage gear in which an external input gear portion and an external output gear portion having a smaller number of teeth than the input gear portion and the torque limiter 72 are coaxially and integrally formed. The output gear portion of the transmission gear 80 meshes with the ring gear 102 that constitutes the torque limiter 72.

  On the other hand, the motor 90 is attached to at least one of the gear housing 40 and the frame 12 as a driving means on the outer side in the rotational radius direction of the spool 20 (below the spool 20 in FIG. 1). In this motor 90, the axial direction of the drive shaft 92 is the same as the axial direction of the spool 20, and the tip side thereof passes through a through hole 94 formed in the bottom portion of the gear housing 40 and enters the inside of the gear housing 40. It has entered.

  On the distal end side of the drive shaft 92 located in the gear housing 40, an external drive gear 96 having a smaller diameter and a smaller number of teeth than the input gear portion of the transmission gear 80 described above is coaxial and integral with the drive shaft 92. When the motor 90 operates and the drive shaft 92 rotates, the rotation of the drive shaft 92 is input from the drive gear 96 to the input gear portion of the transmission gear 80.

(Configuration of torque limiter 72)
Next, the configuration of the torque limiter 72 will be described.

  FIG. 2 is an exploded perspective view schematically showing the configuration of the torque limiter 72.

  As shown in this figure, the torque limiter 72 is provided with a bottom wall 104 inside the ring gear 102 as the first rotating body described above. The bottom wall 104 is formed in a disc shape, and is integrally connected to the inner peripheral portion of the ring gear 102 at one axial end side of the ring gear 102. A pawl holder 106 is provided inside the ring gear 102. The pawl holder 106 includes a slider 108. The slider 108 is formed in a flat plate shape curved in an arc shape with one side in the width direction as the center of curvature. A slider guide 110 is formed on the bottom wall 104 corresponding to the slider 108.

  The slider guide 110 is a recess that is open on the surface facing the inside of the ring gear 102 out of both surfaces in the thickness direction of the bottom wall 104. The slider guide 110 is curved with the center axis of the ring gear 102 as the center of curvature, and the length (longitudinal dimension) of the slider guide 110 along the circumferential direction of the ring gear 102 is set longer than that of the slider 108. For this reason, the slider 108 (the pawl holder 106) disposed inside the slider guide 110 can be displaced so as to rotate around the central axis of the ring gear 102 by being guided by the inner wall of the slider guide 110 between the longitudinal ends of the slider guide 110. .

  A long hole 112 is opened at the bottom of the slider guide 110. The long hole 112 is generally elongated in the circumferential direction of the ring gear 102. Further, a sliding contact guide groove 114 (see FIGS. 3 to 7) is formed in the bottom wall 104 corresponding to the long hole 112. The sliding contact guide groove 114 is a narrow groove whose longitudinal direction is along the longitudinal direction of the long hole 112, and is open on the outer surface of the ring gear 102 out of both surfaces in the thickness direction of the bottom wall 104. The longitudinal dimension of the sliding contact guide groove 114 is sufficiently longer than the longitudinal dimension of the long hole 112, and the long hole 112 is connected to the sliding contact guide groove 114 at the longitudinal intermediate portion of the sliding contact guide groove 114.

  A spring piece 116 shown in FIG. 2 is disposed in the sliding contact guide groove 114. The spring piece 116 is a thin plate-like member whose thickness direction is along the width direction of the sliding contact guide groove 114, and has elasticity that can be bent around an axis whose axial direction is the width direction. The entire length of the spring piece 116 is sufficiently shorter than the longitudinal dimension of the sliding contact guide groove 114, and the spring piece 116 can be displaced in the longitudinal direction of the sliding contact guide groove 114 inside the sliding contact guide groove 114. The spring piece 116 is curved around an axis whose thickness direction is the axial direction, and both ends in the longitudinal direction and substantially the center in the longitudinal direction of the spring piece 116 are in pressure contact with the inner wall of the sliding contact guide groove 114.

  The engaging portion 118 is continuously extended from one end in the width direction of the spring piece 116 on the center side in the longitudinal direction of the spring piece 116. With the spring piece 116 disposed in the sliding contact guide groove 114, the engaging portion 118 passes through the long hole 112 and protrudes into the slider guide 110. The front end of the engaging portion 118 protruding into the slider guide 110 enters a hole portion 119 opened on the back surface in the thickness direction of the slider 108.

  As described above, the slider 108 (the pawl holder 106) can be displaced around the central axis of the ring gear 102 inside the slider guide 110. However, when the slider 108 (the pawl holder 106) attempts to displace within the slider guide 110, it is engaged. The tip of the portion 118 interferes with the inner wall of the hole 119. For this reason, the slider 108 (the pawl holder 106) is displaced with the engaging portion 118, and consequently the spring piece 116. As described above, the both ends in the longitudinal direction and the center side of the spring piece 116 are slidable contact guides. It is in pressure contact with the inner wall of the groove 114. For this reason, the slider 108 cannot be displaced unless the force for displacing the slider 108 is large enough to resist the frictional resistance between the longitudinal ends of the spring piece 116 and the center side thereof and the inner wall of the sliding contact guide groove 114.

  On the other hand, a pawl 120 as a rotation transmitting member is provided on the opposite side of the slider 108 from the slider guide 110. The pawl 120 includes a pawl body 122. A hole 124 is formed in the pawl body 122. The hole 124 passes through the pawl body 122 in the axial direction of the ring gear 102. A shaft 125 passes through the hole 124. The shaft 125 is formed so as to protrude from the surface of the slider 108 opposite to the slider guide 110, and the shaft 125 penetrates the hole 124 so that the shaft 125 rotatably supports the pawl 120. Yes.

  Further, a claw portion 128 is formed in the vicinity of the end portion 126 of the ring body 102 on the rotational circumferential direction winding direction side in the pawl body 122. The claw portion 128 is formed so as to protrude toward the center side of the ring gear 102. A driven gear 130 as a second rotating body is provided at the center of the ring gear 102 corresponding to the claw portion 128. A plurality of external teeth 134 are formed on the outer peripheral portion of the driven gear 130. The valleys between these external teeth 134 correspond to the shape of the claw 128 described above. Here, the surface on one side in the circumferential direction (winding direction side) of the external teeth 134 is generally oriented in the rotational tangential direction of the driven gear 130 at the position of this surface. On the other hand, the surface on the other circumferential side (drawing direction side) of the external teeth 134 is inclined outward in the rotational radial direction of the driven gear 130 with respect to the other circumferential direction. The claw portion 128 is formed corresponding to the shape of the external teeth 134.

  For this reason, when the pawl 120 rotates in the pull-out direction around the central axis of the ring gear 102 with the claw portion 128 inserted between the external teeth 134 adjacent to each other in the circumferential direction, the claw portion 128 is wound around the outer teeth 134. The driven gear 130 is pressed in the take-out direction side to rotate the driven gear 130 in the pull-out direction. In addition, when the pawl 120 rotates in the winding direction around the central axis of the ring gear 102 with the claw portion 128 entering between the adjacent external teeth 134, the claw portion 128 is positioned on the pulling direction side of the external teeth 134. The surface is pressed to rotate the driven gear 130 in the winding direction. However, since the surface of the external teeth 134 on the pulling direction side is inclined as described above, the claw portion 128 is caused by the pressing reaction force from the external teeth 134. It tries to slide with respect to the surface of the external teeth 134 on the pulling direction side so as to be separated from the driven gear 130.

  On the other hand, a torsion coil spring 136 as an urging means is provided on the inner side of the ring gear 102 on the pulling direction side than the pawl 120. One end of the torsion coil spring 136 is locked to the ring gear 102 or the bottom wall 104 with the holding shaft 138 standing from the bottom wall 104 entering the coiled portion, and the other end is a pawl 120. In the pawl main body 122, the spring locking portion 140 formed on the opposite side of the end portion 126 is pressed through the hole 124, and the winding direction side, that is, the claw portion 128 around the shaft 125 is arranged on the driven gear 130. The pawl 120 is urged in a direction to mesh with the external teeth 134.

  Further, a holder spring 150 as a holding means is provided inside the ring gear 102. The holder spring 150 is a kind of plate spring formed by bending or bending a thin plate material whose width direction is along the axial direction of the ring gear 102 around an axis whose width direction is the axial direction.

  The holder spring 150 includes a base portion 152. The base 152 is curved with the center axis of the pawl 120 as the center of curvature, and is disposed between the inner peripheral portion of the ring gear 102 and the holding wall 153 erected from the bottom wall 104. Displacement in the direction is restricted. An interference portion 154 is formed continuously from the tip of the base portion 152 (the end portion on the drawing direction side).

  The interference portion 154 is provided on the pulling direction side with respect to the end portion 156 opposite to the end portion 126 of the pawl 120, and pulls out the plate material constituting the holder spring 150 around an axis whose axial direction is the width direction. It is formed by bending or curving into a substantially U shape opening toward the direction side. In a state where the claw portion 128 meshes with the external tooth 134 of the driven gear 130, the end portion of the pawl 120 is positioned on the base 152 side with respect to the interference portion 154, and the external tooth 134 is caused by the pressing reaction force from the external tooth 134. When the claw portion 128 slides with respect to the surface on the drawing direction side and tries to rotate away from the driven gear 130, the interference portion 154 interferes with the end portion 156 to restrict the rotation of the pawl 120.

  Further, as shown in FIG. 2, a pawl stopper 160 as an engagement restricting means is provided on the opposite side of the ring gear 102 from the bottom wall 104. The pawl stopper 160 is formed in a flat plate shape. A circular hole 162 is formed in the pawl stopper 160, and a shaft portion 164 formed coaxially and integrally with the driven gear 130 from one end surface in the axial direction of the driven gear 130 passes through the circular hole 162. ing.

  A plurality of pressure contact pieces 166 are erected from the peripheral edge of the circular hole 162 in the pawl stopper 160 toward one side in the thickness direction of the pawl stopper 160. These pressure contact pieces 166 are in pressure contact with the outer peripheral portion of the shaft portion 164 by elasticity. That is, the pawl stopper 160 is held on the shaft portion 164 by friction between the pressure contact piece 166 and the outer peripheral portion of the shaft portion 164. Further, the gear portion 132 opposite to the shaft portion 164 is formed coaxially and integrally with the shaft portion 164 via the outer teeth 134.

  On the other hand, the pawl stopper 160 held by the shaft portion 164 is provided with a contact portion 168. The contact portion 168 is formed by partially bending the pawl stopper 160, and the thickness direction thereof is the rotational tangential direction of the driven gear 130 at the position where the contact portion 168 is formed. A pressing portion 170 is formed inside the ring gear 102 so as to correspond to the contact portion 168.

  The pressing portion 170 faces the contact portion 168 in the rotational circumferential direction of the ring gear 102 and the driven gear 130. For example, the pressing portion 170 is connected to the driven gear 130 in a state where the pawl portion 128 of the pawl 120 is separated from the external teeth 134 of the driven gear 130. On the other hand, when the ring gear 102 rotates in the winding direction (one in the circumferential direction), the pressing part 170 approaches the contact part 168 and contacts the contact part 168. In this state, when the ring gear 102 further rotates in the winding direction, the pressing portion 170 presses the abutting portion 168 to rotate the pawl stopper 160 together with the ring gear 102 against the friction between the pressure contact piece 166 and the shaft portion 164. Let

  Further, an interference piece 172 as an engagement restricting portion is formed on the pawl stopper 160 on the drawing direction side of the contact portion 168. The interference piece 172 is also formed by partially bending the pawl stopper 160, and the thickness direction thereof is along the radial direction of the circular hole 162. The interference piece 172 is formed so as to be positioned radially outward of the driven gear 130 from the end of the external tooth 134. When the contact portion 168 is in contact with the pressing portion 170, a claw portion is formed around the shaft 125. The claw portion 128 faces the claw portion 128 on the rotational direction side of the driven gear 130 when the 128 is engaged with the external teeth 134 of the driven gear 130. When the pawl 120 tries to rotate around the shaft 125 with the interference piece 172 facing the claw portion 128 in this way, the claw portion 128 is interfered with the interference piece 172. Thereby, in this state, the claw portion 128 cannot mesh with the external teeth 134 of the driven gear 130.

  Thus, a pressing piece 174 is formed inside the ring gear 102 corresponding to the claw portion 128 in a state of being interfered with the interference piece 172. When the ring gear 102 rotates relative to the pawl 120 in the pull-out direction in a state where the claw portion 128 enters the valley between the external teeth 134 (a state where the claw portion 128 meshes with the external teeth 134), it is shown in FIG. Thus, the pressing piece 174 is positioned outside the claw portion 128 along the radial direction of the ring gear 102.

  When the ring gear 102 further rotates in the drawing direction in this state, the inclined surface 176 on the drawing direction side of the pressing piece 174 contacts the pawl 120 from the winding direction side. In this state, the rotation of the pawl 120 in the pull-out direction around the shaft 125 is restricted, and when the ring gear 102 further rotates in the pull-out direction in this state, the inclined surface 176 presses the pawl 120 in the pull-out direction, and this pull-out The pressing force in the direction is transmitted to the external teeth 134 through the pawl 120, and the driven gear 130 rotates in the pull-out direction.

  Furthermore, a long hole 178 is formed in the pawl stopper 160. The long hole 178 is curved so as to be long in the circumferential direction of the circular hole 162, and the tip of the shaft 125 that has passed through the hole 124 enters the long hole 178.

<Operation and effect of the present embodiment>
Next, the operation and effect of the present embodiment will be described through the description of the operation diagrams in the torque limiter 72 of FIGS. 3 to 7, the pawl stopper 160 described above is shown with only the abutting portion 168, the interference piece 172, and the long hole 178, for easy understanding of the operation. Illustration of the overall external shape and the like is omitted.

  In the webbing take-up device 10, as shown in FIG. 3, the claw portion 128 of the pawl 120 enters between the outer teeth 134 adjacent in the circumferential direction in the driven gear 130, and the claw portion 128 meshes with the driven gear 130. Yes. In this state, when the motor 90 is driven to rotate in the forward direction, and the forward drive force of the motor 90 is transmitted to the ring gear 102 of the torque limiter 72 via the drive gear 96 and the transmission gear 80, the ring gear 102 is rotated in one of the circumferential directions, that is, Rotate in the winding direction. When the ring gear 102 rotates in the winding direction, the shaft 125 that supports the pawl 120 presses the pawl 120 around the central axis of the ring gear 102 in the winding direction.

  Here, if the slider 108 of the pawl holder 106 does not reach the end position of the slider guide 110 on the pulling direction side, the pressing reaction force from the surface on the pulling direction side of the external teeth 134 causes the inner wall of the sliding contact guide groove 114 and the spring to move. The pawl holder 106 is moved to the end position on the drawing direction side of the slider guide 110 against the friction between the pieces 116. In this state, when the ring gear 102 further rotates in the winding direction, the shaft 125 presses the surface of the external teeth 134 on the drawing direction side via the pawl 120 in the winding direction. As a result, the driven gear 130 rotates in the winding direction, and as a result, the spool 20 rotates in the winding direction.

  As described above, in this state, the claw portion 128 of the pawl 120 receives a pressing reaction force from the surface of the external tooth 134 on the pulling direction side, and the claw portion 128 slides with respect to the external tooth 134 and meshes with the driven gear 130. The pawl 120 tries to turn in a direction to cancel the above. However, in this state, since the end is located on the base 152 side of the interference unit 154, the end of the pawl 120 to be rotated is interfered with the interference unit 154. Thereby, the rotation of the pawl 120 in the direction to cancel the meshing with the driven gear 130 is restricted, and the rotational force in the winding direction of the ring gear 102 is reliably transmitted to the driven gear 130 via the pawl 120.

  On the other hand, when the webbing belt 22 is pulled, a rotational force in the pulling direction opposite to the winding direction is applied to the spool 20, and the spool 20 rotates in the pulling direction. Since the rotational force applied to the spool 20 in the pulling direction is transmitted to the driven gear 130, if the pawl 120 is engaged with the driven gear 130, the surface on the pulling direction side of the external teeth 134 of the driven gear 130 is the pawl 120. The outer teeth 134 are pressed, and the rotational force in the pulling direction transmitted to the driven gear 130 is transmitted to the pawl 120. The pulling direction rotational force transmitted to the pawl 120 is transmitted to the ring gear 102 and further transmitted to the motor 90 via the transmission gear 80 and the drive gear 96.

  Here, the pressing force with which the surface of the external teeth 134 on the pulling direction side presses the external teeth 134 of the pawl 120 by the rotational force transmitted to the driven gear 130 is large enough to elastically deform the interference portion 154. Then, as shown in FIG. 4, the end portion 156 of the pawl 120 presses the interference portion 154 and elastically deforms the interference portion 154.

  When the pressing force received from the external teeth 134 further increases from this state, the end portion further elastically deforms the interference portion 154, the end portion gets over the interference portion 154, and the end portion on the opposite side of the base portion 152 of the interference portion 154 The pawl 120 rotates so that is positioned. By the rotation of the pawl 120, the pawl portion 128 of the pawl 120 is separated from the driven gear 130 as shown in FIG. 5, and the meshing between the pawl portion 128 and the driven gear 130 is eliminated.

  Further, when the engagement between the claw portion 128 and the driven gear 130 is eliminated in this way, the rotational force in the pulling direction from the driven gear 130 to the ring gear 102 is not transmitted, so that the rotating force in the pulling direction of the spool 20 is not driven. Even if it is transmitted to 130, the driven gear 130 only idles. For this reason, an excessive load is applied to a member that transmits a driving force or a rotational force between the spool 20 and the driven gear 130, for example, the clutch 62 due to a rotational force in the pulling direction that is greater than a predetermined size of the spool 20. Can be prevented.

  In this state, since the rotational force in the pulling direction is not transmitted from the driven gear 130 to the ring gear 102, the ring gear 102 is relatively wound around the driven gear 130 by rotating the driven gear 130 in the pulling direction. The ring gear 102 rotates relative to the pawl stopper 160 in which the pressure contact piece 166 is in pressure contact with the shaft portion 164 of the driven gear 130 in the winding direction.

  Furthermore, as shown in FIG. 5, when the ring gear 102 rotates relative to the driven gear 130 and the pawl stopper 160 in the winding direction until the contact portion 168 contacts the pressing portion 170 of the ring gear 102, On the other hand, the interference piece 172 is positioned on the rotational direction side of the pawl 120 for meshing the claw portion 128 with the driven gear 130. For this reason, in this state, when the pawl 120 tries to rotate in the direction in which the claw portion 128 meshes with the driven gear 130, the claw portion 128 is interfered with the interference piece 172. As a result, the pawl 120 cannot rotate in a direction in which the claw portion 128 meshes with the driven gear 130.

  Further, the pawl stopper 160 is attached to the driven gear 130 by the pressure contact piece 166 being in pressure contact with the shaft portion 164 of the driven gear 130, but the friction between the outer peripheral portion of the shaft portion 164 and the pressure contact piece 166 is reduced. When a counteracting rotational force is applied to the pawl stopper 160, the pawl stopper 160 can rotate relative to the shaft portion 164.

  Here, in this state, since the contact portion 168 is in contact with the pressing portion 170 from the winding direction side of the pressing portion 170 as described above, when the ring gear 102 further rotates in this winding direction, the pressing portion 170 presses the contact portion 168. As a result, the pawl stopper 160 rotates in the winding direction along with the ring gear 102, so that the relative positional relationship between the claw portion 128 and the interference piece 172 does not change. For this reason, even if the ring gear 102 rotates in the winding direction in a state where the interference piece 172 interferes with the claw portion 128, the rotation restriction of the pawl 120 by the interference piece 172 is maintained.

  Next, when the motor 90 is driven in reverse from this state, first, the ring gear 102 rotates in the pull-out direction with respect to the pawl holder 106. As a result, the interference portion 154 of the holder spring 150 is separated from the locking portion 140 of the pawl 120 in the pull-out direction. In this state, when the ring gear 102 further rotates in the pull-out direction, the pawl 120 rotates with the shaft 125 in the pull-out direction around the central axis of the ring gear 102.

  However, the pawl stopper 160 having the interference piece 172 does not rotate in the pulling-out direction due to friction with the outer peripheral portion of the shaft portion 164 because the press contact piece 166 is pressed against the outer peripheral portion of the shaft portion 164. Therefore, as shown in FIG. 6, the ring gear 102 and the pawl 120 rotate in the pull-out direction with respect to the pawl stopper 160. The ring gear 102 and the pawl 120 rotate in the pulling direction with respect to the pawl stopper 160 until the tip of the shaft 125 reaches the end of the elongated hole 178 on the pulling direction side. In this state, when the ring gear 102 further rotates in the pulling direction, The tip of the shaft 125 presses the end of the elongated hole 178 on the drawing direction side. As a result, the pawl stopper 160 rotates in the pull-out direction together with the ring gear 102 along with the shaft 125.

  When the pawl stopper 160 rotates in the pull-out direction in this manner and the interference piece 172 is separated from the space between the adjacent external teeth 134, the pawl 120 is wound in the engagement direction by the urging force of the torsion coil spring 136. And the claw portion 128 meshes with the external teeth 134. Further, when the ring gear 102 rotates in the pull-out direction in this state, as shown in FIG. 7, the inclined surface 176 of the pressing piece 174 contacts the pawl 120 from the winding direction side, and the pawl 120 moves in the pull-out direction around the shaft 125. The rotation is restricted. In this state, when the ring gear 102 further rotates in the pulling direction, the inclined surface 176 presses the pawl 120 in the pulling direction, and the pressing force in the pulling direction is transmitted to the external teeth 134 via the pawl 120, and the driven gear 130 is pulled out. Rotate in the direction.

  In this state, if the driven gear 130 and the spool 20 are mechanically connected by the clutch 62, the driven gear 130 rotates in the pulling direction, and the rotation of the driven gear 130 in the pulling direction is transmitted to the clutch 62. Thus, the mechanical connection between the driven gear 130 and the spool 20 by the clutch 62 is canceled, and the forward drive force of the motor 90 is transmitted to the clutch 62 via the torque limiter 72 until the driven gear 130 and the spool 20 are The released state of the mechanical connection is maintained (that is, the state before the motor 90 outputs the forward driving force is restored).

  Thus, in the present embodiment, when the pressing reaction force applied to the claw portion 128 from the surface of the external tooth 134 on the pulling direction side exceeds a certain magnitude, the pawl 120 and the driven gear 130 are engaged with each other. Can be forcibly eliminated, and the transmission of rotation from the ring gear 102 to the driven gear 130 can be cut off, and this rotation transmission cut-off state can be maintained until the ring gear 102 rotates in the pull-out direction.

  Further, when the ring gear 102 rotates in the pull-out direction from the rotation transmission cut-off state, the pawl portion 128 of the pawl 120 can be meshed with the driven gear 130 again, and the rotational force of the ring gear 102 in the pull-out direction is applied to the driven gear. 130. For this reason, for example, if the rotational force in the pull-out direction is transmitted to the ring gear 68 of the clutch 62 so that the connection between the ring gear 68 and the driven rotating portion 63 by the clutch pawl can be eliminated, the ring gear 102 as described above. Thus, the rotational force transmitted in the pulling direction is transmitted to the driven gear 130, and the connection between the ring gear 68 and the driven rotating portion 63 by the clutch pawl can be eliminated.

DESCRIPTION OF SYMBOLS 10 Webbing winding device 20 Spool 22 Webbing belt 90 Motor (drive means)
102 Ring gear (first rotating body)
120 pawl (rotation transmission member)
130 Driven gear (second rotating body)
136 Torsion coil spring (biasing means)
150 Holder spring (holding means)
160 pawl stopper (engagement restricting means)
168 Contact portion 172 Interference piece (engagement restricting portion)

Claims (2)

Drive means capable of outputting drive force for forward rotation and reverse rotation; and
The webbing belt is wound and stored from the longitudinal base end side by locking the longitudinal base end side of the long belt-shaped webbing belt and rotating in the winding direction, and the positive output from the driving means is stored. A spool that rotates in the winding direction by transmitting a rolling driving force;
It is interposed between the drive means and the spool, and the forward drive force is output from the drive means to mechanically connect the drive means and the spool, and from the drive means to the spool. A clutch that transmits the forward driving force and mechanically releases the connection between the driving unit and the spool by transmitting the reverse driving force from the driving unit;
It is interposed between the driving means and the clutch, and mechanically connects the driving means and the clutch to transmit the normal rotation driving force to the clutch, and more than a predetermined magnitude transmitted from the clutch side. And the rotational force in the pulling direction opposite to the winding direction is transmitted to release the mechanical connection between the driving means and the clutch, and maintain the released state. A torque limiter that mechanically connects the driving means and the clutch by transmitting the reverse driving force output from the driving means;
A webbing take-up device comprising: A first rotating body that is interposed between the drive means and the spool, and rotates in the rotational circumferential direction by the forward rotation driving force and rotates in the rotational circumferential direction by the reverse rotation driving force;
A second rotating body coupled directly or indirectly to the spool so as to be able to transmit rotation to the spool;
The second rotating body is supported by the first rotating body and rotates together with the first rotating body, and a part of the second rotating body is engaged with the second rotating body to transmit the rotation of the first rotating body to the second rotating body. While rotating the rotating body, the first rotating body tries to rotate relative to the second rotating body in one direction in the circumferential direction of the rotation, and the pressing force received from the second rotating body causes the second rotating body to move with the second rotating body. A rotation transmission member movable in a direction to release the engagement;
Biasing means for biasing the rotation transmitting member in a direction to engage the second rotating body;
The rotation transmission member is held so as to restrict the displacement of the rotation transmission member in a direction that interferes with the rotation transmission member and releases the engagement with the second rotating body, and the pressing force is a predetermined magnitude. A holding means for allowing the displacement of the rotation transmitting member in a direction to cancel the engagement with the second rotating body by being elastically deformed by exceeding the thickness;
It is provided so as to be capable of relative rotation coaxially with the first rotating body, and is caused by the engagement of the rotation transmitting member with the second rotating body being canceled by the pressing force from the second rotating body. Due to the relative rotation of the first rotating body with respect to the second rotating body, the abutting portion comes into contact with the first rotating body from one side in the rotational circumferential direction of the first rotating body and is pressed by the first rotating body. At a rotational position where the contact portion rotates with the first rotating body and the contact portion contacts the first rotating body, the engagement restricting portion interferes with the rotation transmitting member and engages with the second rotating body. Engagement restricting means for restricting the displacement of the rotation transmitting member;
The webbing retractor according to claim 1, wherein the torque limiter is configured to include

Images