JP4996538B2 - Webbing take-up device - Google Patents

Description

  The present invention relates to a webbing take-up device that takes up a webbing for restraining a vehicle occupant.

Conventionally, some webbing take-up devices are equipped with a mechanism (so-called pretensioner mechanism) that forcibly winds a webbing around a take-up shaft in the event of an emergency of a vehicle and improves the restraint performance of an occupant by webbing ( For example, see Patent Document 1). In such a pretensioner mechanism, gas is supplied into the cylinder to move the piston, and a rack formed on the piston is meshed with a pinion gear provided on the winding shaft so that the winding shaft is webbed. It is designed to rotate in the taking direction.
JP 2002-274325 A

  By the way, the webbing take-up device as described above includes a mechanism (so-called force limiter mechanism) that absorbs inertial energy acting on the occupant by allowing a predetermined amount of webbing to be pulled out after the pretensioner mechanism is activated. is there. In such a webbing take-up device, as the webbing is pulled out, the take-up shaft is rotated in the webbing pull-out direction together with the pinion gear, so that the piston of the pretensioner mechanism is pushed back into the cylinder by the pinion gear. At this time, since the residual pressure of the gas in the cylinder may give resistance to the movement of the piston (that is, the rotation of the winding shaft), the influence of the residual pressure is taken into consideration when designing the force limiter mechanism. It was necessary and the design work was complicated.

  An object of the present invention is to obtain a webbing take-up device that can prevent or suppress the pretensioner mechanism from imparting resistance to the rotation of the take-up shaft after the pretensioner mechanism is actuated.

  A webbing take-up device according to a first aspect of the invention is a take-up device that winds a webbing for restraining a vehicle occupant by being rotated in the take-up direction, and is rotated in the draw-out direction by being pulled out. When a pulling output of a predetermined value or more acts on the webbing while the shaft and the winding shaft are rotatably supported with respect to the vehicle body, and the winding shaft is restricted from rotating in the pull-out direction, Support means for allowing the take-up shaft to be displaced in the radial direction with respect to the vehicle body by the pulling output, and a moving member that engages with the take-up shaft during operation, and moves the moving member in the engaged state. Thereby rotating the winding shaft in the winding direction and releasing the engagement state by the displacement of the winding shaft, and at least after the pretensioner mechanism is actuated, the winding. It is characterized by having a locking mechanism for restricting the rotation of the said pull-out direction of the axis, a.

  In the webbing take-up device according to claim 1, when the pretensioner mechanism is operated, the moving member of the pretensioner mechanism is engaged with the take-up shaft, and the take-up shaft is rotated in the take-up direction by the movement of the moving member. The As a result, the webbing is wound around the winding shaft, and the restraining force of the occupant due to the webbing increases. Further, at least after the pretensioner mechanism is actuated, the lock mechanism restricts the rotation of the take-up shaft in the pull-out direction. In this state, for example, when a pulling force exceeding a predetermined value acts on the webbing due to an inertial force acting on the occupant, the support means that rotatably supports the winding shaft is displaced in the radial direction with respect to the vehicle body of the winding shaft. Is acceptable. Thereby, the engagement state of the moving member of the pretensioner mechanism and the winding shaft is released. Therefore, it can prevent or suppress that a pretensioner mechanism gives resistance to rotation of a winding shaft.

  The 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 support means supports the take-up shaft at least during operation of the pretensioner mechanism, and The strength member that guides the displacement of the winding shaft, and the winding shaft that rotatably supports the winding shaft, and the deformation of the winding shaft that is deformed by the pulling output that is input through the winding shaft. It has the weak member which accept | permits a displacement, It is characterized by the above-mentioned.

  In the webbing take-up device according to the second aspect, the take-up shaft is rotatably supported by the fragile member, but at least when the pretensioner mechanism is operated, the take-up shaft is supported by the strength member. Further, when a pulling force of a predetermined value or more acts on the webbing, the fragile member is deformed by a load input to the fragile member via the winding shaft. Thereby, the radial displacement of the winding shaft relative to the vehicle body is allowed, and the winding shaft is guided by the strength member. Thereby, since a support means can be materialized, a support means can be made into a simple structure.

  A webbing take-up device according to a third aspect of the present invention is the webbing take-up device according to the second aspect, wherein the take-up shaft has a pinion rotatably supported by the strength member, and the movement The member is characterized in that a rack that engages with the pinion when the pretensioner mechanism is operated is formed.

  In the webbing take-up device according to the third aspect, when the pretensioner mechanism is operated, the rack of the moving member is engaged with the pinion of the take-up shaft. The pinion is rotatably supported by the strength member and is rotated in the winding direction by the movement of the moving member. Thereby, the winding shaft is rotated in the winding direction. Further, the take-up shaft is restricted from rotating in the pull-out direction by the lock mechanism after at least the operation of the pretensioner mechanism. In this state, when a pulling force of a predetermined value or more is applied to the webbing, the brittle member that supports the winding shaft is deformed, and the pinion is guided by the strength member to be displaced in the radial direction with respect to the vehicle body. Displaced. Thereby, the meshing state of the rack of the moving member and the pinion is released.

  Thus, since the displacement of the pinion meshed with the rack of the moving member is guided directly by the strength member, the meshed state between the rack and the pinion can be accurately released.

  The webbing take-up device according to the invention described in claim 4 is the webbing take-up device according to claim 3, wherein the pinion is provided with a shaft portion, and the strength member is formed with a long hole, The pinion is supported by the strength member by fitting the shaft portion into the long hole, and the shaft portion is moved along the long hole during the displacement.

  In the webbing take-up device according to claim 4, the shaft portion provided in the pinion is fitted in a long hole formed in the strength member, whereby the pinion is rotatably supported by the strength member. Yes. When the pinion is displaced in the radial direction with respect to the vehicle body together with the main body portion of the winding shaft, the pinion and the main body portion are displaced by moving the pinion shaft portion along the long hole of the strength member. Will be guided. As described above, since the displacement of the pinion and the main body is guided by the long hole formed in the strength member, the configuration for guiding the displacement of the pinion and the main body can be simplified.

  The webbing take-up device according to a fifth aspect of the present invention is the webbing take-up device according to any one of the first to fourth aspects, wherein the support means allows the displacement of the take-up shaft. The direction is set so as to face the direction opposite to the direction of the load input from the moving member to the winding shaft when the moving member moves, and the pulling output input from the webbing to the winding shaft is set. It is characterized by being set to the same side as the direction of action.

  In the webbing take-up device according to claim 5, the direction in which the supporting means allows the radial displacement of the take-up shaft is opposite to the direction of the load input from the moving member to the take-up shaft when the moving member moves. Set to the side. For this reason, it can suppress that a winding shaft displaces to a radial direction unnecessarily by the load from a moving member. Further, the direction in which the supporting means allows the displacement of the winding shaft in the radial direction is set to the same side as the direction of action of the pulling force input from the webbing to the winding shaft. For this reason, the winding shaft can be favorably displaced by the pulling force.

  As described above, in the webbing take-up device according to the present invention, it is possible to prevent or suppress the pretensioner mechanism from imparting resistance to the rotation of the take-up shaft after the pretensioner mechanism is actuated.

  FIG. 1 is a cross-sectional view of a webbing take-up device 10 according to an embodiment of the present invention viewed from the back side. 2 to 4 show a partial configuration of the webbing take-up device 10 in a schematic side view. 1 to 4 show a webbing take-up device 10 mounted on the right side of the vehicle (the driver's seat side of the right handle). In each figure, an arrow UP indicates an upward direction of a vehicle (not shown) on which the webbing take-up device 10 is mounted, an arrow FR indicates a forward direction of the vehicle, and an arrow IN indicates a vehicle of the vehicle. The width inside direction is shown.

  The webbing take-up device 10 according to this embodiment includes a frame 12. The frame 12 is formed by bending a metal plate into a substantially U-shaped cross section, and includes a side wall 12A and another side wall 12B that face each other, and a rear side wall 12C that connects the one side wall 12A and the other side wall. It has. The rear side wall 12C is fixed to the vehicle body, whereby the frame 12 is attached to the vehicle body. A substantially circular through hole 14 is formed in one side wall 12A of the frame 12, and a substantially circular through hole 16 is formed in the other side wall 12B.

  Between the one side wall 12A and the other side wall 12B of the frame 12, a cylindrical spool 18 constituting the main body of the winding shaft 17 is provided. A base end portion of an occupant restraining webbing 20 formed in a long belt shape is locked to the spool 18, and the spool 18 is rotated around its axis (in the direction of arrow A in FIGS. 2 to 4, hereinafter this). When the direction is referred to as “winding direction”), the webbing 20 is wound around the outer peripheral portion of the spool 18 from the base end side. On the other hand, if the webbing 20 is pulled from the front end side, the webbing 20 is pulled out while the spool 18 rotates about the axis (in the direction of arrow B in FIGS. 2 to 4). The rotation direction of the spool 18 is referred to as a “drawing direction”).

  The intermediate portion in the longitudinal direction of the webbing 20 is wound around a through anchor (not shown) attached to the vehicle body above the webbing take-up device 10. Therefore, the webbing 20 extends upward from the spool 18 (see arrows F in FIGS. 1 and 1 to 4, hereinafter, this direction is referred to as “extension direction”).

  A torsion shaft 22 (energy absorbing member) that constitutes a force limiter mechanism provided on the take-up shaft 17 is disposed at the axial center of the spool 18. The torsion shaft 22 is formed of a metal material such as iron, and includes a cylindrical torsional deformation portion 22A that is torsionally deformed when a torsional load of a predetermined value or more is applied. A cylindrical support shaft portion 22B is coaxially and integrally provided at one axial end portion (the right end portion in FIG. 1) of the twist deformation portion 22A. The support shaft portion 22B passes through the through hole 14 of the one side wall 12A and protrudes to the outside of the frame 12 (outside of the one side wall 12A).

  A lock mechanism 24 is provided outside the one side wall 12A. The lock mechanism 24 has a box-shaped sensor cover 26 (fragile member) having one end opened. The sensor cover 26 is formed of a resin material, and is attached to the one side wall 12A with the opening side facing the one side wall 12A. The sensor cover 26 is provided with a bearing portion 26A that supports a support shaft portion 22B protruding outward from the frame 12, and the support shaft portion 22B (one axial end side of the torsion shaft 22) 26 is rotatably supported.

  A base lock 28 constituting the lock mechanism 24 is provided at one end in the axial direction of the spool 18 (the right end in FIG. 1). The base lock 28 is disposed in the through hole 14 of the one side wall 12 </ b> A, and is connected to the spool 18 so as to be relatively rotatable. Further, one end in the axial direction of the torsional deforming portion 22A is connected to the base lock 28 so as not to be relatively rotatable, and one end in the axial direction of the spool 18 is connected to the sensor cover 26 via the base lock 28 and the torsion shaft 22. It is rotatably supported.

  A lock plate 30 is attached to the base lock 28. The lock plate 30 has a locking tooth 30A formed on its tip side between a meshing position where the locking tooth 30A meshes with a ratchet tooth 14A formed on the inner peripheral portion of the through hole 14, and a release position where the meshing is released. It is possible to move relative to the base lock 28 in the radial direction.

  A V gear 32 that constitutes the lock mechanism 24 is accommodated inside the sensor cover 26. The V gear 32 is supported by the support shaft portion 22B of the torsion shaft 22 so as to be able to follow and rotate. A guide hole (not shown) is formed in the V gear 32, and a guide pin (not shown) provided in the lock plate 30 is inserted into the guide hole. As a result, the lock plate 30 is normally held in the release position, but when the base lock 28 rotates relative to the V gear 32 in the pull-out direction, the lock plate 30 is moved to the meshing position. ing.

  Further, an acceleration sensor 34 for VSIR is provided below the V gear 32. The acceleration sensor 34 raises the sensor lever 38 by an inertial force acting on the ball 36 when the vehicle suddenly decelerates. The sensor lever 38 is provided with a claw portion 38A that can be engaged with the external teeth 32A formed on the outer peripheral portion of the V gear 32. The claw portion 38A is engaged with the external teeth 32A, so that the sensor cover 26 is engaged. Relative rotation of the V gear 32 is restricted.

  A sensor holder (not shown) is attached to the inside of the sensor cover 26, and an inner tooth that can engage with a WSIR pawl (not shown) that is pivotally supported by the V gear 32 is formed on the sensor holder. ing.

  On the other hand, a sleeve 40 constituting the winding shaft 17 is attached to the other axial end portion of the spool 18 (the left end portion in FIG. 1). The sleeve 40 includes a connecting portion 40A fitted inside the spool 18 and is connected to the spool 18 so as not to be relatively rotatable. Further, the other end in the axial direction of the torsional deformable portion 22A is fitted to one side (right side in FIG. 1) of the connecting portion 40A, and the sleeve 40 is connected to the torsion shaft 22 so as not to be relatively rotatable. ing. A cylindrical support shaft portion 40B is provided on the other side of the connecting portion 40A. The support shaft portion 40B passes through the through hole 16 of the other side wall 12B and protrudes to the outside of the frame 12 (outside of the other side wall 12B).

  On the outside of the other side wall 12B, a box-shaped spring cover 42 (fragile member) having one end opened is provided. The spring cover 42 is formed of a resin material, and is attached to the other side wall 12B in a state where the opening side faces the other side wall 12B (Note that in FIG. 1, the illustration of this attaching portion is omitted for convenience of explanation. ) The spring cover 42 is provided with a bearing portion 42A that supports a support shaft portion 40B protruding outward from the frame 12, and the other axial end of the spool 18 is connected to the spring cover 42 via the sleeve 40. It is rotatably supported.

  A spiral spring 44 is provided inside the spring cover 42. The spiral spring 44 has an outer end locked to the spring cover 42 and an inner end locked to the support shaft portion 40B of the sleeve 40, and biases the spool 18 in the winding direction via the sleeve 40. .

  On the other hand, between the spiral spring 44 and the other side wall 12 </ b> B of the frame 12, an operation source 48 that constitutes a pretensioner mechanism 46 is disposed above the sleeve 40. The operating source 48 includes a substantially L-shaped cylindrical cylinder 50, and the cylinder 50 is fixed to the outside of the other side wall 12B.

  As shown in FIG. 2, a bottomed cylindrical generator cap 52 is fixed to the upper end side of the cylinder 50, and a gas generator 54 is accommodated inside the generator cap 52. The gas generator 54 includes an ignition device (not shown). When the ignition device is activated, high-pressure gas is generated in the cylinder 50.

  In the cylinder 50, a piston 56 (moving member) formed in a long rectangular bar shape is accommodated. The piston 56 is formed with a rack 56A at a portion other than the upper end side. A flange portion 56B is provided at the upper end portion of the piston 56, and a seal member 58 is attached to the upper side of the flange portion 56B. The seal member 58 seals between the upper end portion of the piston 56 and the inner peripheral portion of the cylinder 50. For this reason, when the gas generator 54 generates gas in the cylinder 50, the piston 56 is pushed by the pressure of the gas, and the piston 56 moves downward from the lower end of the cylinder 50 (opposite to the extending direction of the webbing 20). ) (See FIG. 3).

  A cover plate 60 (strength member) is fixed to the outside of the other side wall 12B. The cover plate 60 is formed in a substantially triangular container shape by press-molding a metal plate, and the lower end side of the cylinder 50 is covered by the cover plate 60. The cover plate 60 forms a space for the piston 56 to move together with the other side wall 12B. The piston 56 protruding downward from the lower end of the cylinder 50 is a space covered by the cover plate 60. Move in.

  Further, the cover plate 60 is formed with a long hole 60A. As shown in FIG. 2, the long hole 60 </ b> A is provided at a position facing the axial center portion of the spool 18, and is arranged in a state where the longitudinal direction is along the radial direction of the spool 18. One end of the long hole 60A in the longitudinal direction (right side in FIG. 2) is disposed below the other end in the longitudinal direction of the long hole 60A (left side in FIG. 2), and the long hole 60A is an arrow in FIG. It is inclined with respect to the vertical direction of C (moving direction of the piston 56). In the present embodiment, the inclination angle α of the long hole 60A with respect to the vertical direction of the arrow C is set to about 20 degrees, for example.

  The inner peripheral portion on one end side (lower end side) in the longitudinal direction of the long hole 60A is formed concentrically with the spool 18, and the support shaft portion 40B of the sleeve 40 is not in contact with the lower end side of the long hole 60A. It penetrates with. Further, a pinion 62 constituting a winding shaft is attached to the lower end side of the long hole 60A.

  The pinion 62 is formed in a substantially cylindrical shape by a metal material such as iron, and a circular through hole 64 is formed in the shaft center portion. The support shaft portion 40B of the sleeve 40 passes through the through hole 64. The pinion 62 includes a gear portion 62A having pinion teeth 63 formed on the outer peripheral portion, and a cylindrical shaft portion 62B provided coaxially and integrally on one side (left side in FIG. 1) in the axial direction of the gear portion 62A. And have. The shaft portion 62 </ b> B is rotatably fitted to the lower end side of the long hole 60 </ b> A of the cover plate 60 and is locked by a snap ring 66. Thereby, the pinion 62 is rotatably supported by the cover plate 60. The support shaft portion 40B of the sleeve 40 passes through the through hole 64 of the pinion 62 in a non-contact state. However, for convenience of explanation in FIGS. 1 to 5, the inner peripheral portion of the through hole 64 and the support shaft portion. The gap between the outer periphery of 40B is omitted.

  Further, the pinion teeth 63 of the gear portion 62 </ b> A are arranged on the movement locus of the rack 56 </ b> A of the piston 56 protruding from the cylinder 50. For this reason, when the piston 56 protrudes from the cylinder 50, the rack 56A of the piston 56 is engaged with the pinion teeth 63 of the gear portion 62A, and the piston 56 is moved downward in this engaged state. As a result, the pinion 62 is suddenly rotated in the winding direction (the direction of arrow A in FIGS. 2 to 5).

  The direction of the load L input from the load input surface 65 to the pinion teeth 63 is such that the inclination angle γ (pressure angle) relative to the arrow C (movement direction of the piston 56) in FIG. 5 is greater than the inclination angle α of the long hole 60A. Is set too small.

  On the other hand, a cam portion 62C having a larger diameter than that of the gear portion 62A is provided coaxially and integrally on the other axial end side (right side in FIG. 1) of the gear portion 62A. The cam portion 62C is inserted into a knurled hole 68 formed on the other side (left side in FIG. 1) of the connecting portion 40A of the sleeve 40. Uneven portions (not shown) are alternately formed on the outer peripheral portion of the cam portion 62C, and the inner peripheral portion of the knurled hole 68 is knurled (not shown). An annular gap is formed between the outer peripheral part of the cam part 62 </ b> C and the inner peripheral part of the knurled hole 68, and a clutch plate 70 as a clutch member constituting the winding shaft 17 is formed in this gap. Is arranged.

  The clutch plate 70 is formed in a substantially ring shape by a metal plate, is attached to the outer peripheral portion of the cam portion 62C, and is supported in a non-contact state with respect to the knurled hole 68 of the sleeve 40. Therefore, the sleeve 40 rotates independently of the pinion 62, and the pinion 62 does not follow and rotate even when the spool 18 is rotated together with the sleeve 40 as the webbing 20 is pulled out and taken up. It has become.

  However, as described above, when the pinion 62 is suddenly rotated in the winding direction with the movement of the piston 56, the clutch plate 70 is pushed by the convex portion of the cam portion 62C and is plastically deformed. It is pressed against the inner periphery of 68. In this state, the clutch plate 70 is sandwiched between the convex portion of the cam portion 62 </ b> C and the inner peripheral portion of the knurled hole 68, so that the pinion 62 and the sleeve 40 are integrally connected. As a result, the spool 18 is rotated in the winding direction.

  Next, the operation of this embodiment will be described.

  In the webbing retractor 10 having the above-described configuration, the gas generator 54 of the pretensioner mechanism 46 generates high-pressure gas in the cylinder 50 when the vehicle is in an emergency (for example, when suddenly decelerating). It protrudes downward from the lower end of the cylinder 50 (see FIG. 3). Thereby, the rack 56 </ b> A of the piston 56 is meshed with the pinion teeth 63 of the pinion 62, and the pinion 62 is rapidly rotated in the winding direction by the piston 56. At this time, an excessive load is input to the pinion 62 from the piston 56, but the pinion 62 is slidably in contact with the inner peripheral surface on the lower end side of the long hole 60 </ b> A, so that the pinion 62 is made of the metal cover plate 60. It is strongly supported by.

  Further, when the pinion 62 is suddenly rotated in the winding direction, the clutch plate 70 is plastically deformed by the convex portion provided on the cam portion 62C of the pinion 62. As a result, the pinion 62 and the sleeve 40 are connected, and the spool 18 is rotated together with the sleeve 40 and the pinion 62 in the winding direction. As a result, the webbing 20 is forcibly wound around the spool 18 and the restraining force of the occupant by the webbing 20 increases.

  At this time, the sensor lever 38 is raised by the inertial force that the ball 36 of the acceleration sensor 34 acts on itself. Thereby, the claw portion 38A of the sensor lever 38 is engaged with the external tooth 32A of the V gear 32, and the rotation of the V gear 32 is restricted. In this state, when the webbing 20 is pulled out by the inertial force acting on the occupant and the spool 18 is rotated in the pulling direction together with the base lock 28, the lock in which the guide pin is engaged with the guide hole formed in the V gear 32. The plate 30 is moved radially outward of the base lock 28. Accordingly, the lock teeth 30A of the lock plate 30 are engaged with the ratchet teeth 14A of the frame 12, and the base lock 28 is restricted from rotating in the pull-out direction with respect to the frame 12. When the rotation of the base lock 28 in the pull-out direction is restricted in this way, the spool 18 connected to the base lock 28 via the torsion shaft 22 and the sleeve 40 is restricted from rotating in the pull-out direction.

  In this state, when the inertial force of the occupant is further input to the webbing 20 and a pulling force F exceeding a predetermined value acts on the webbing 20, the pulling output F is applied to the support shaft portion 22B of the torsion shaft 22 connected to the spool 18. Is input to the bearing portion 26A of the sensor cover 26 and is input to the bearing portion 42A of the spring cover 42 via the support shaft portion 40B of the sleeve 40. For this reason, the bearing portions 26A and 42A are deformed by the support shaft portions 22B and 40B, and the spool 18 is allowed to be displaced in the radial direction.

  For this reason, the spool 18 tends to be displaced in the direction in which the pulling force F acts, but a pinion 62 is connected to the other axial end of the spool 18 via the sleeve 40 and the clutch plate 70. The shaft portion 62B of the pinion 62 is fitted in the long hole 60A of the cover plate 60. For this reason, when the shaft portion 62B is moved along the long hole 60A, the displacement of the pinion 62 and the spool 18 is guided, and the pinion 62 is separated from the piston 56. Then, the shaft portion 62B contacts the inner peripheral surface on the upper end side of the long hole 60A, so that the radial displacement of the pinion 62 and the spool 18 is restricted (the state shown in FIG. 4).

  In this state, the meshing state of the pinion teeth 63 of the pinion 62 and the rack 56A of the piston 56 is released. Further, since the displacement of the spool 18 in the radial direction is restricted as described above, the spool 18 tries to rotate in the pull-out direction by the pull output F, and the torsional deformation portion 22A of the torsion shaft 22 receives a twist load. Entered. When this torsional load is equal to or greater than a predetermined value, the torsionally deforming portion 22A is torsionally deformed, thereby allowing relative rotation of the spool 18 in the pull-out direction with respect to the base lock 28. Thereby, the webbing 20 is pulled out and the load (inertial energy) acting on the occupant from the webbing 20 is absorbed.

  As described above, in the present embodiment, after the pinion 62 is rotated by the piston 56 (after the pretensioner mechanism 46 is actuated), the pinion 62 is displaced in the radial direction, and the pinion teeth 63 and the rack 56A are displaced. Since the meshing state is released, it is possible to prevent the pretensioner mechanism 46 from imparting resistance to the rotation of the spool 18 when the torsional deformation portion 22A of the torsion shaft 22 is torsionally deformed (when the force limiter mechanism is activated). .

  Moreover, in the present embodiment, the resin sensor cover 26 and the spring cover 42 are deformed, so that the spool 18 and the pinion 62 are allowed to be displaced in the radial direction, and the pinion 62 is supported by the metal cover plate 60. Therefore, the meshing state of the pinion teeth 63 and the rack 56A can be released with a simple configuration.

  In the present embodiment, the pinion 62 meshed with the rack 56A of the piston 56 is directly guided in displacement by the cover plate 60, so that the meshed state between the rack 56A and the pinion 62 is accurately released. Can do.

  Furthermore, in this embodiment, since the displacement of the pinion 62 is guided by the long hole 60A formed in the cover plate 60, the displacement of the pinion 62 can be guided with a simple configuration.

  In the present embodiment, as shown in FIG. 5, the load L input from the rack 56A to the pinion teeth 63 has an inclination angle γ with respect to the vertical direction of the vehicle, and an inclination angle of the long hole 60A with respect to the horizontal direction of the vehicle. The direction in which the pinion 62 is allowed to be displaced (the direction of the arrow D in FIG. 5) is set to be opposite to the direction of the load L. For this reason, it is possible to suppress the pinion 56 from being unnecessarily displaced in the radial direction by the component force of the load L.

  Further, the direction in which the pinion 62 is allowed to be displaced (the direction of arrow D in FIG. 5) is the direction of action of the pull output F input to the pinion 62 from the webbing 20 via the spool 18 (the direction of arrow UP in FIG. 5). Set to the same side. For this reason, the spool 18 and the pinion 62 can be favorably displaced by the pull output F.

  In the above embodiment, the shaft portion 62A of the pinion 62 is moved along the long hole 60A of the cover plate 60, so that the pinion 62 is guided in the radial displacement. This is not a limitation. For example, a circular hole that pivotally supports the shaft portion 62B of the pinion 62 is formed in the cover plate 60, and a weak portion is provided around the circular hole, and the shaft portion 62A breaks the weak portion when the pulling force F acts. Thus, the pinion 62 may be configured to be guided in the radial displacement.

  In the above embodiment, the winding shaft includes the spool 18, the pinion 62, and the clutch plate 68, and the pinion 62 is rotated by the piston 56 (moving member). However, the present invention is not limited to this. The pinion 62 and the clutch plate 68 may be omitted, and the spool 18 may be directly rotated by the moving member.

  Furthermore, although the said embodiment demonstrated the case where a support means was comprised by the sensor cover 26 and the spring cover 42 as a weak member, and the cover plate 60 as an intensity | strength member, this invention is not limited to this and supports. Any means may be used as long as it allows the winding shaft to be displaced in the radial direction with respect to the vehicle after the pretensioner mechanism is actuated, and the configuration thereof can be changed as appropriate.

It is sectional drawing which looked at the webbing winding device concerning the embodiment of the present invention from the back side. It is a schematic side view which shows the partial structure of the webbing winding device concerning the embodiment of the present invention. It is a side view corresponding to Drawing 2 showing the state where the piston of the pretensioner mechanism which constitutes the webbing take-up device concerning the embodiment of the present invention protrudes from the cylinder. It is a side view corresponding to Drawing 2 showing the state where the pinion which constitutes the webbing take-up device concerning the embodiment of the present invention was displaced in the radial direction. It is the enlarged view to which a part of FIG. 3 was expanded.

Explanation of symbols

10 Webbing Winder 17 Winding Shaft 18 Spool (Main Body)
20 Webbing 24 Lock mechanism 26 Sensor cover (fragile member, support means)
42 Spring cover (fragile member, support means)
46 Pretensioner mechanism 56 Piston (moving member)
60 Cover plate (strength member, support means)
60A Long hole 62 Pinion 62B Shaft

Claims (5)

Winding the webbing for restraining the vehicle occupant by being rotated in the winding direction, and a winding shaft that is rotated in the pulling direction by pulling out the webbing;
When the winding shaft is rotatably supported with respect to the vehicle body, and the pulling output exceeding a predetermined value acts on the webbing in a state where the winding shaft is restricted from rotating in the pulling direction, the winding shaft Supporting means for allowing a radial displacement with respect to the vehicle body by the pulling force;
A moving member that engages with the take-up shaft during operation; moving the move member in the engaged state causes the take-up shaft to rotate in the take-up direction; and the displacement of the take-up shaft A pretensioner mechanism that releases the engaged state by:
A lock mechanism that restricts rotation of the take-up shaft in the pull-out direction after at least the operation of the pretensioner mechanism;
A webbing take-up device comprising:   The support means supports the winding shaft at least during operation of the pretensioner mechanism, supports a strength member that guides the displacement of the winding shaft, and rotatably supports the winding shaft. The webbing take-up device according to claim 1, further comprising a fragile member that allows the displacement of the take-up shaft by being deformed by the pulling output that is input through the take-up shaft.   The winding shaft includes a pinion rotatably supported by the strength member, and the moving member is formed with a rack that is meshed with the pinion when the pretensioner mechanism is operated. The webbing retractor according to claim 2.   The pinion is provided with a shaft portion, the elongated member is formed with a long hole, and the pinion is supported by the strength member by fitting the shaft portion into the elongated hole. The webbing retractor according to claim 3, wherein the shaft portion is moved along the elongated hole when displaced.   The direction in which the support means allows the displacement of the winding shaft is set toward the opposite side of the direction of the load input from the moving member to the winding shaft when the moving member moves, The webbing take-up device according to any one of claims 1 to 4, wherein the webbing take-up device is set toward the same side as the direction of action of the pulling force input from the webbing to the take-up shaft. .

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