Belt strap holder

Abstract

Belt webbing receiving device (10) comprising: a take-up shaft (20) capable of receiving a webbing (22) worn by an occupant, which is rotated in a take-up direction (A) to receive the webbing (22) and which is rotated in a pull-out direction (B) by pulling out the webbing (22); a rotating body (38) capable of rotating in accordance with rotation of the take-up shaft (20); a limiting member (26) that limits rotation of the take-up shaft (20) in the pull-out direction (B) by the limiting member (26) by causing it to be operated; an operating member (44) provided on the rotating body (38) and displaced to cause operation of the limiting member (26) when the rotating body (38) is rotated in the pulling-out direction (B) at a specific speed or higher; and a limiting body (66) which is moved to an admission position which permits a displacement of the operating component (44) when the rotating body (38) is rotated in the withdrawal direction (B), and which is moved to a limiting position which allows the operating component (44) to abut against the limiting body (66) when the rotating body (38) is rotated in the receiving direction (A), wherein the limiting body (66) limits the displacement of the operating component (44) by the abutment of the operating component (44) against the limiting body (66), wherein a contact angle (θ) of the limiting body (66) and the operating component (44) is set at 90° or greater, and wherein a strength of the operating member (44) at a location located on a limiting body side is set lower than a strength of the operating member (44) at a location farther away from the limiting body (66) than the location located on the limiting body side of the operating member (44).

Description

The present invention relates to a webbing take-up device that takes up webbing carried (being) (worn) by (around) an occupant.Prior ArtIn a webbing take-up device described in JP 2008-24 284 A, when a reel and a V-gear are suddenly rotated in a pull-out direction, an inertial mass of the V-gear is pivoted (pivoted) so that a ratchet is operated (operated), and rotation of the reel in the pull-out direction is restricted (prevented).One end of a friction spring (clamping spring) is supported by the V gear so as to be able to rotate, and a lever and a cover are attached to the friction spring. When the roller and the V gear are rotated, the cover generates a frictional force and the frictional spring, the lever, and the cover are rotated.When the roller and the V gear are rotated in the extraction direction, the lever is rotated to a non-abutment position and the pivoting (pivoting) of the inertial mass is permitted. When the roller and the V gear are rotated in a take-up direction, the lever is rotated to an abutting position and the inertial mass abuts on the lever, so that pivoting (pivoting, swinging) of the inertial mass is restricted (prevented).In a configuration in which the pivoting of the inertial mass is prevented by the inertial mass (the operation member) abutting against the lever (limiting body), it is important that an input of an excessive load from the inertial mass to (to) the lever(s) is prevented.US 2011 / 0 290 929 A1 discloses a known webbing take-up device including: a take-up shaft capable of taking up webbing carried by an occupant, which is rotated in a take-up direction to take up the webbing and which is rotated in a pull-out direction by the pulling-out of the webbing; a rotating body capable of rotating in association with rotation of the take-up shaft; a restricting member that restricts rotation of the take-up shaft in the pull-out direction by the restricting member by being caused to operate; an operating member that is provided on the rotating body and that is displaced to cause operation of the restricting member when the rotating body is rotated in the pull-out direction at a specific speed or higher speed; A restriction body that is moved to an allowing position that allows displacement of the operation member when the rotating body is rotated in the extraction direction and that is moved to a restricting position that allows the operation member to abut on the restriction body when the rotating body is rotated in the receiving direction, wherein the restriction body restricts displacement of the operation member by the abutment of the operation member on the restriction body, wherein a contact angle of the restriction body and the operation member is set to 90° or greater.Further known belt strap receiving devices are shown in US 2009 / 0 218 432 A1 and US 2007 / 0 290 091 A1.SUMMARY OF THE INVENTIONIt is the object of the present invention to provide a webbing take-up device capable of preventing an input of an excessive load from an operation member (operation member) to (on) a (one) restriction body.The object of the present invention is achieved by a webbing take-up device having the features of claim 1.A further preferred embodiment of the present invention is described in dependent claim 2.A webbing take-up device according to the present invention includes: a take-up shaft capable of taking up webbing supported (laid) by (around) an occupant, which is rotated in a take-up direction to take up the webbing, and which is rotated in a pull-out direction by the pulling-out of the webbing; a rotating body capable of rotating in association with rotation of the take-up shaft; a restricting member that restricts rotation of the take-up shaft in the pull-out direction by the restricting member by being caused to operate; an operating member (operating member) provided on the rotating body and which is displaced to cause operation of the restricting member when the rotating body is rotated in the pull-out direction at a specific speed or higher speed; and a restriction body moved to an allowing position that allows the operation member to be displaced when the rotating body is rotated in the extraction direction and moved to a restricting position that allows the operation member to abut on the restriction body when the rotating body is rotated in the receiving direction, wherein the restriction body restricts the displacement of the operation member by the abutment of the operation member on the restriction body, wherein a contact angle of the restriction body and the operation member is set to be 90° or greater, and wherein a strength of the operation member at a location that is on a restriction body side is set to be lower than a strength of the operation member at a location that is farther from the restriction body than the location that is on the restriction body side of the operation member.Preferably, limitation of the displacement of the operation member by the limitation body is released by the operation member and the limitation body performing contact sliding; and at least a part of a surface of the operation member performing contact sliding with the limitation body is curved (bent) with (in) a smaller radius than a radius of a surface of the limitation body performing contact sliding with the operation member.In the webbing take-up device according to the present invention, the webbing is taken up by rotating the take-up shaft in the take-up direction, and the take-up shaft is rotated by pulling out the webbing in the pull-out direction. The rotating body is capable of rotating in association with (accompanying) rotation of the take-up shaft. The operation member (operation member) is displaced (moved) and causes the restriction member to be operated (operated) to restrict (prevent) rotation of the take-up shaft in the extraction direction when the rotating body has been rotated in the extraction direction at a specific speed or a greater speed.When the rotating body is rotated in the extraction direction, the restricting body is moved to the permission position. The displacement of the operating member is thereby permitted. When the rotating body is rotated in the receiving direction, the restricting body is moved to the restricting position, whereby the operation member can be abutted and the displacement of the operation member due to the abutment of the operation member on the restricting body is restricted (prevented). In particular, rotation of the take-up shaft in the extraction direction is not restricted (prevented) because the operation member does not cause the operation of the restriction member.Note that the contact angle of the restricting body and the operating member is set to 90° or greater. Thus, when the operation member abuts and presses the restriction body, the operation member and the restriction body can easily perform contact sliding on their contact surfaces. In other words, when the operation member is pressed onto the restriction body with a high load, the restriction body can be moved in a direction to escape (escape) from the operation member. This prevents an input of an excessive load from the operation member from being applied to the restriction body.In addition, the location of the operation member on the restriction body side is set with a lower strength, thereby enabling the location of the operation member on the restriction body side to be easily bent when the operation member is pressed onto the restriction body. This further allows the restriction body to escape from the operation member when the operation member is pressed on the restriction body.Preferably, the operating member and the limiting body perform contact sliding after abutting each other such that the limitation by the limiting body is released from the displacement of the operating member. Note that at least a portion (part) of a surface of the operation member that performs the contact sliding with the restriction body is curved (bent) with (in) a smaller radius than the radius of a surface of the restriction body that performs the contact sliding with the operation member. This enables a reduction in a frictional force between the surface of the operation member that is curved as described above and the surface of the restriction body that performs the contact sliding with the operation member. This further allows the restriction body to escape from the operation member when the operation member is pressed on the restriction body.BRIEF DESCRIPTION OF THE DRAWINGSEmbodiments of the invention are described in detail below with reference to the following figures, in which: FIG. 1 is an exploded perspective view illustrating a webbing take-up device; FIG. 2 is an end view illustrating relevant portions of a webbing take-up device; FIG. 3 is an end view corresponding to FIG. 2, illustrating relevant portions of a webbing take-up device in a state where a W-latch abuts against a limiting cover; FIG. 4 is a sectional view illustrating main portions of the webbing take-up device taken along a line 4- 4 illustrated in FIG. 2 ; FIG. 5 is an enlarged end view illustrating an abutting portion between a W-latch and a limit cover; and FIG. 6 is an even further enlarged end view illustrating an abutting portion between a W-latch and a limit cover.DETAILED DESCRIPTIONFIG. 1 is an exploded perspective view illustrating a webbing take-up device 10 according to an exemplary embodiment as viewed from a diagonal direction from the rear, outer, and upper sides. Note that in the drawings, the arrow FR indicates the vehicle front side, the arrow OUT indicates the vehicle outer width direction, and the arrow UP indicates the vehicle upper side, in a state where the webbing take-up device 10 is mounted on (in) a vehicle. In the following explanation, simple references to the longitudinal and vertical directions refer to a longitudinal direction in the vehicle longitudinal direction and a vertical direction in the vehicle vertical direction.As illustrated in FIG. 1, the webbing take-up device 10 of the present exemplary embodiment includes a frame 12 formed in a substantially U-shape as viewed from the vehicle upper side. The frame 12 includes a rear plate 12A extending along the vehicle height direction with its thickness direction along the vehicle width direction, and a leg plate 12B and a leg plate 12C respectively extending from the two vehicle front-rear direction side end portions of the rear plate 12A toward the vehicle width outer direction to be bent from the rear plate 12A and disposed facing each other. The rear plate 12A of the frame 12 is fixed to a vehicle body such that the webbing take-up device 10 is mounted on the vehicle body.An arrangement hole 14 and an arrangement hole 16 formed substantially in a circle are formed in the leg plate 12B and the leg plate 12C, respectively. The arrangement hole 14 and the arrangement hole 16 face each other along the vehicle front-rear direction. Ratchet teeth 14A (inner teeth) constituting a lock mechanism (lock mechanism) 18 serving as a restriction portion are formed around the entire outer periphery of the arrangement hole 14.A substantially circular columnar roller 20 serving as a take-up shaft is provided between the leg plate 12B and the leg plate 12C of the frame 12. One end 20A on the rear side (leg plate 12B side) of the roller 20 is disposed inside the arrangement hole 14 of the leg plate 12B, and another end 20B on the front side (leg plate 12C side) of the roller 20 is disposed inside the arrangement hole 16 of the leg plate 12C. The roller 20 is thereby capable of rotating in the circumferential direction in a state where its axial direction is parallel to the longitudinal direction. Note that unless otherwise stated, a simple reference hereinafter refers to the axial direction, the radial direction, and the circumferential direction refers to the axial direction, the radial direction, and the circumferential direction of the roller 20.A base end side of a long band-shaped webbing 22 (band) is attached to the reel 20, and the webbing 22 is taken up (wound) from its base end side onto the reel 22. The webbing 22 is taken up (wound) on the reel 20 when the reel 22 is rotated in a take-up direction (the arrow direction A in FIG. 1, which is a circumferential direction). The pulley 20 is rotated in a pull-out direction (the arrow direction B in FIG. 1, which is the other circumferential direction) when the webbing 22 is pulled out of the pulley 20. The webbing 22 extends outward toward the upper side from the frame 20, and the webbing 22 is worn (wound around an occupant) by an occupant seated on a vehicle seat, which is not illustrated in the drawings.A flat coil spring (driving spring) (not illustrated in the drawings) serving as a receiving urging member (receiving energizing member) is coupled to the other end 20B of the roller 20, and the flat coil spring is disposed on the front side of the frame 12 (the front side of the leg plate 12C). The flat coil spring urges (energizes) the pulley 20 in the take-up direction such that the urging force (energizing force) in the take-up direction of the pulley 20 acts on the webbing 22. Thus, when the webbing 22 is worn by the occupant, slack of the webbing 22 is eliminated by the urging force of the flat coil spring, and when the webbing 22 is released by the occupant, the webbing 22 is taken up (wound) on the spool 20 due to the urging force of the flat coil spring.A housing hole 24 open to the outer radial direction of the roller 20 is formed in the one end 20A of the roller 20. A long plate-shaped ratchet 26, which serves as a limiting member constituting the ratchet mechanism 18, is accommodated inside the housing hole 24 to be movable. A ratchet tooth 26A is formed at one end of the ratchet 26. A circular columnar operation shaft (operation shaft) 28 is integrally provided on the ratchet 26, and the operation shaft 28 protrudes outward toward the rear side from the ratchet 26.A circular columnar rotary shaft 30 is integrally provided at an axial center portion of the one end 20A of the roller 20. The rotation shaft 30 protrudes outward from the roller 20 toward the rear side and is disposed coaxially with the roller 20.A sensor mechanism 32 constituting the lock mechanism 18 is provided at the rear side of the frame 12 (the rear side of the leg plate 12B).The sensor mechanism 32 includes a substantially circular tube-shaped bottom sensor holder 34 formed by a resin material and open to the front side (the leg plate 12B side). The sensor holder 34 is fixed to the leg plate 12B. A bottom surface inside the sensor holder 34 forms a planar friction surface 34A (see FIG. 4 ), and the friction surface 34A is disposed perpendicular to the axial direction of the roller 20.A substantially circular tube-shaped bottom sensor cover 36 formed by a resin material and open to the front side is provided at the rear side of the sensor holder 34 (the opposite side to the leg plate 12B side). The sensor cover 36 is fixed to the leg plate 12B in a state in which the sensor holder 34 is accommodated therein.A V-gear 38 serving as a rotating body is provided inside the sensor holder 34. The V gear 38 is formed by a resin material and is formed in a bottomed circular tube shape and is open to the rear side. A tubular portion 38C formed in a tubular shape is provided to protrude outward at an axial center portion of a bottom wall 38A of the V gear 38. The V gear 38 can rotate relative to the roller 20 because the rotation shaft 30 of the roller 20 is inserted into the tubular portion 38C.A long operation groove (operation groove) not illustrated in the drawings is formed in the bottom wall 38A of the V gear 38. The operation shaft 28 of the lock blade 36 is inserted into the operation groove. A compression coil spring 40 is disposed between the V gear 38 and the one end 20A of the roller 20. The compression coil spring 40 urges the V gear 38 in the extraction direction relative to the roller 20 (urges the spool 20 in the take-up direction relative to the V gear 38), and causes the operation shaft 28 to abut on a longitudinal end of the operation groove. Rotation of the V gear 38 in the extraction direction relative to the roller 20 and the urging force of the compression coil spring 40 is thereby stopped, and the V gear 38 can rotate about the rotation shaft 30 of the roller 20 accompanying (associated with) the rotation of the roller 20. Ratchet teeth 38B (external teeth) are formed on the entire outer periphery of the V gear 38.A circular columnar swing shaft 42 is provided to protrude outward from the bottom wall 38A of the V gear 38. The pivot shaft 42 is disposed on the radially outer side of the center axis line of the V gear 38. The central axis line of the pivot shaft 42 and the central axis line of the V gear 38 are parallel to each other.As shown in FIG. 2, a W-latch 44 serving as an operating member (operating member) is supported by the pivot shaft 42 to be pivotable (pivoted, displaced). More specifically, the W pawl 44 is formed in a substantially U shape to be open on the axial center portion side of the V gear 38 in the end view, and a pivot shaft insertion hole 44A through which the pivot shaft 42 is inserted is formed in a center portion (circumferential direction intermediate portion) of the W pawl 44 provided in the circumferential direction (the circumferential direction of the V gear 38). Another circumferential side end portion of the W-pawl 44 forms an engaging portion 44B that engages with an engaging portion 34B of the sensor holder 34. A circumferentially provided side end portion of the W-pawl 44 forms an abutting portion 44C that extends to a side of the limiting cover 70 of a limiting body 66, as described below. The abutting portion 44C is formed to gradually decrease toward the one circumferential direction side, and a circumferential direction side end surface of the abutting portion 44C forms an abutting surface S 1 abutting on the limiting cover 70. In the present exemplary embodiment, the thickness of the abutment portion 44C in the axial direction is set thinner than the thickness of a circumferential direction intermediate portion 44D of the W pawl 44 in the axial direction. The strength of the abutting portion 44C is thereby lower than the strength of the circumferential direction intermediate portion 44D of the W pawl 44.A return spring 46 is disposed between the W pawl 44 and the V gear 38, and the return spring 46 urges the W pawl 44 in a return direction (the arrow direction C). Pivoting of the W pawl 44 in the returning direction by the urging force of the return spring 46 is stopped by a restricting protrusion portion 38D provided on the V gear 38.When the V gear 38 is rotated in the withdrawing direction, a force due to the inertia acts on the W pawl 44 toward the receiving direction with respect to the V gear 38, the W pawl 44 thereby tends to pivot in an operating direction (the arrow direction D) with respect to the V gear 38, and when the V gear 38 has been suddenly rotated in the withdrawing direction, the force due to the inertia acting on the W pawl 44 exceeds the urging force of the return spring 46, the W pawl 44 thereby being pivoted in the operating direction with respect to the V gear 38, and the engaging portion 44B of the W pawl 44 engages with the engaging portion 34B of the sensor holder 34 so as to stop the rotation of the V gear 38 in the extraction direction.As shown in FIG. 1, an acceleration sensor 48 is provided at a lower end portion of the sensor holder 34. The acceleration sensor 48 includes a substantially U-shaped housing 50 that is open toward the lower side as viewed from the vehicle front side, and a recess-shaped curved surface 50A is formed on an upper surface of a bottom wall of the housing 50. A spherical body (ball body, ball) 52 is disposed on the curved surface 50A, and a substantially plate-shaped lever 54 is disposed on the upper side of the ball body 52. A base end of the lever 54 is supported by a side wall of the housing 50 to be rotatable, and the V gear 38 is disposed at the upper side of a front end of the lever 54. The lever 54 is rotated toward the upper side due to the rolling of the ball body 52 over the curved surface 50A of the housing 50, and is raised. The front end of the lever 54 is thereby meshed with the ratchet teeth 38B of the V gear 38 to stop rotation of the V gear 38 in the extraction direction.When the roller 20 is rotated, against the urging force of the compression coil spring 40 in the extraction direction relative to the V gear 38 at the time when rotation of the V gear 38 in the extraction direction is stopped as described above, the operation shaft 28 of the ratchet 26 is moved toward another longitudinal end side of the operation groove of the V gear 38 so that the ratchet 26 is moved toward the radial outer direction of the roller 20 (the one end 20A). The ratchet tooth 26A of the ratchet pawl 26 thereby meshes with the ratchet teeth 14A of the frame 12 (the leg plate 12B), and rotation of the roller 20 in the extraction direction is locked (restricted, prevented). Withdrawal of the webbing 22 from the reel 20 is thereby locked (prevented, restricted).As illustrated in FIG. 4, a support shaft 56 formed in a circular column shape is provided to protrude outward from the bottom wall 38A of the V gear 38. The central axis line of the support shaft 56 and the central axis line of the V gear 38 are parallel to each other. A support hole 58 is formed in an axial central portion of the support shaft 56. The support hole 58 is open to the rear side (the friction surface 34A side of the sensor holder 34), and the front side thereof is closed by the bottom wall 38A.The restricting body 66 is supported by the support shaft 56 so as to be able to rotate. As illustrated in FIG. 2, the restricting body 66 is constituted by a friction spring 68 formed by bending a long rod-shaped member, and the restricting cover 70 and a friction cover 72 attached to the friction spring 68.As illustrated in FIG. 4, one end portion of the friction spring 68 forms an insertion portion 68A inserted into and supported by the support hole 58, and another end portion of the friction spring 68 forms a friction cover attachment portion 68B to which the friction cover 72 is attached. A location on the friction spring 68 between the insertion portion 68A and the friction cover attachment portion 68B, which is also a location on the side of the insertion portion 68A, constitutes a limiting cover attachment portion 68C to which the limiting cover 70 (see FIG. 2 ) is attached.A location on the friction spring 68 between the insertion portion 68A and the friction cover attachment portion 68B, which is also a location on the friction cover attachment portion 68B side, constitutes a bending portion 68D. The bent portion 68D is bent in a state where the restricting body 66 is disposed between the friction surface 34A side of the sensor holder 34 and the bottom wall 38A of the V gear 38. The friction cover 72 can press the friction surface 34A of the sensor holder 34 by the spring force of the bending portion 68D. Thus, when the V gear 38 is rotated, the friction cover 72 slides over the friction surface 34A such that the frictional force is generated between the friction cover 72 and the friction surface 34A.As illustrated in FIG. 2, the limiting cover 70 is formed by a resin material and is formed in a substantially L shape in the end view. The limit cover 70 includes a quadrangular block-shaped attachment portion 70A attached to the limit cover attachment portion 38C of the friction spring 68, and an abutment portion 70B extending from an end portion of the attachment portion 70A toward the abutment portion 44C side of the W pawl 44. An end surface of the abutting portion 70B forms an abutting surface S 2 against which the abutting portion 44C of the W pawl 44 abuts, and the abutting surface S 2 is curved in an arc shape in the end view.When the V gear 38 is rotated in the receiving direction, the restricting body 66 is rotated toward one side (the arrow direction D side) around the support shaft 56 (see FIG. 4 ), and the restricting body 66 is rotated to a restricting position (the position represented by the solid lines in FIG. 2 ). Then, as illustrated in FIG. 3, the abutting portion 44C (the abutting surface S 1) of the W pawl 44 abuts against the abutting portion 70B (the abutting surface S 2) of the limit cover 70 such that pivoting (pivoting) of the W pawl 44 in the operation direction relative to the V gear 38 is limited (prevented).Note that, in the present exemplary embodiment, as illustrated in FIG. 5, the shapes of the abutment surface S 1 and the abutment surface S 2 are set such that a contact angle θ of both surfaces at a contact point P of the abutment portion 44C (abutment surface S 1) of the W pawl 44 and the abutment portion 70B (abutment surface S 2) of the limit cover 70 is 90° or greater.Specifically, in FIG. 5 (as viewed from the axial direction of the roller 20), in a state where the abutting portion 44C (abutting surface S 1) of the W pawl 44 and the abutting portion 70B (abutting surface S 2) of the limit cover 70 have been brought into contact with each other in a static state (in the state where a pressure does not occur at the contact point of the two surfaces), the angle θ formed by a line L 1 passing through a rotation center C of the limit cover 70 and the contact point P (the line L 1 extending from the rotation center T of the limit cover 70 toward the contact point P) and a tangential line L 2 of the abutting surface S 1 and the abutting surface S 2 at the contact point P (the tangential line L 2 is, The distance which extends from the contact point P toward the inner side of the V gear 38) is set to be between 90 to 135°. Thus, when the force with which the abutting portion 44C (abutting surface S 1) of the W pawl 44 presses the abutting portion 70B (abutting surface S 2) of the limit cover 70 exceeds a specific (specific) value, the abutting portion 44C (abutting surface S 1) of the W pawl 44 and the abutting portion 70B (abutting surface S 2) of the limit cover 70 perform contact sliding, and the limit body 66 rotates toward the other side (the arrow direction C side) around the support shaft 56 (see FIG. 4 ). Specifically, the restriction body 66 is rotated from the restriction position (the position illustrated by solid lines in FIG. 2 ) to a permission position side (the position illustrated by broken lines in FIG. 2 ) as described below.As illustrated in FIG. 6, a portion of the abutting surface S 1 of the W pawl 44 is curved (bent) with a radius of curvature R 1 that is smaller than a radius of curvature R 2 of the abutting surface S 2 of the limit cover 70. the portion curved with the radius of curvature R 1 is positioned on the inner side as viewed in the radial direction with respect to the position where the abutting portion 44C (abutting surface S 1) of the W pawl 44 and the abutting portion 70B (abutting surface S 2) of the limit cover 70 are in contact with each other in the static state.As illustrated in FIG. 2, when the V gear 38 is rotated in the extraction direction, the restricting body 66 is rotated toward the other side (the arrow direction C side) around the support shaft 56 (see FIG. 4 ), and the restricting body 66 is rotated to the permission position (the position illustrated by the broken lines in FIG. 2 ). Thus, the abutting portion 44C (abutting surface S 1) of the W pawl 44 is in a state not abutting against the abutting portion 70B (abutting surface S 2) of the limit cover 70 even when the W pawl 44 is pivoted due to which the W pawl 44 is allowed to pivot in the operation direction relative to the V gear 38.Operation and Advantageous Effects of the Present Exemplary EmbodimentThe operation and advantageous effects of the present exemplary embodiment will be explained below.In the webbing take-up device 10 having the above configuration, the webbing 22 is pulled and the pulley 20 and the V gear 38 are rotated in the pulling-out direction against the urging force of the flat coil spring, so that the webbing 22 is pulled out of the pulley 20 to be worn by an occupant (to be worn by an occupant).When the vehicle is rapidly decelerated, the ball body 52 rolls over the curved surface 50A of the housing 50 in the acceleration sensor 48 and rises such that the lever 54 is rotated toward the upper side and that the front end thereof is meshed (i.e., meshed) with the ratchet teeth 38B of the V gear 38. Rotation in the extraction direction of the V gear 38 is thereby stopped.Further, when the vehicle is decelerated rapidly, the occupant moves due to the inertial force such that the webbing 22 is pulled out from the pulley 20 by the occupant and the pulley 20 and the V gear 38 are rapidly rotated in the pulling-out direction.When the V gear 38 is further rotated in the extraction direction, the restricting body 66 is rotated by a frictional force occurring between the frictional surface 34A of the sensor holder 34 and the frictional cover 72, and is rotated to the permission position (the position shown by the broken lines in FIG. 2 ). It is thereby allowed that the W pawl 44 pivots (pivoted, pivoted) in the operating direction relative to the V gear 38.Thus, when the V gear 38 has been rapidly pulled in the pulling-out direction as described above, the W pawl 44 is pivoted in the operating direction relative to the V gear 38, the engagement portion 44B of the W pawl 44 engages with the engagement portion 34B of the sensor holder 34, and the rotation in the pulling-out direction of the V gear 38 is stopped.When the rotation in the extraction direction of the V gear 38 is stopped, since the roller 20 is rotated against the urging force of the compression coil spring 40 in the extraction direction relative to the V gear 38, the operation shaft 28 of the ratchet 26 is moved toward the other longitudinal end side of the operation groove of the V gear 38 and the ratchet 26 is moved toward the radial outer direction of the roller 20. The ratchet tooth 26A of the ratchet 26 is thereby brought into mesh with the ratchet teeth 14A of the frame 12 and the rotation of the roller 20 in the pulling-out direction is locked. The webbing 22 pulled out from the reel 20 is thereby locked (locked), and the occupant is restrained by the webbing 22.When the webbing 22 has been released by the occupant, the pulley 20 and the V gear 38 are rotated in the take-up direction by the urging force of the flat coil spring, and the webbing 22 is taken up (wound) on the pulley 20.Note that when the take-up of the webbing 22 onto the pulley 20 is completed, it is possible that the pulley 20 and the V gear 38 are rapidly rotated in the pull-out direction in response to the stopping (stopping) of the rotation in the take-up direction.Thus, when the V gear 38 is rotated in the receiving direction, the restricting body 66 is rotated by a frictional force occurring between the frictional surface 34A of the sensor holder 34 and the frictional cover 72, and is moved to the restricting position (the position shown by the solid line in FIG. 2 ). Then, as illustrated in FIG. 3, the abutting portion 44C (abutting surface S 1) of the W pawl 44 abuts against the abutting portion 70B (abutting surface S 2) of the limit cover 70, so that the W pawl 44 is prevented (limited) from being pivoted (pivoted) in the operation direction relative to the V gear 38.Thus, since the rotation of the V gear in the extraction direction is not stopped due to the engagement portion 44B of the W pawl 44 not engaged with the sensor holder 34, the pawl 26 is not moved toward the radial direction outer side of the reel 20. Thus, the rotation of the roller 20 in the pull-out direction is not locked because the ratchet tooth 26A of the ratchet pawl 26 is not engaged with the ratchet teeth 14A of the frame 12. In particular, according to the present exemplary embodiment, locking (referred to as end locking) of pulling out the webbing 22 from the pulley 20 can be prevented or avoided, thereby allowing the webbing 22 to be pulled out from the pulley 20.Note that, in the present exemplary embodiment, as described above, the contact angle θ between both surfaces at the contact point of the abutment portion 44C (abutment surface S 1) of the W pawl 44 and the abutment portion 70B (abutment surface S 2) of the limit cover 70 is set to 90° or greater. Thus, when a high load is input from the abutment portion 44C of the W pawl 44 to the abutment portion 70B of the limit cover 70 and the force pressing the abutment portion 44C (abutment surface S 1) of the W pawl 44 onto the abutment portion 70B (abutment surface S 2) of the limit cover 70 exceeds the specific (specified) value, the abutment portion 44C (abutment surface S 1) of the W pawl 44 and the abutment portion 70B (abutment surface S 2) of the limit cover 70 perform contact sliding, and the limit body 66 is rotated about the support shaft 56 (see FIG. 4 ) toward the other side (the arrow direction C side). Specifically, the restriction body 66 is rotated from the restriction position (the position indicated by the solid lines in FIG. 2 ) toward the permission position side (the position indicated by the broken lines in FIG. 2 ). Thus, by the present exemplary embodiment, the input of an excessive load from the W pawl 44 to the limiting body 66 (onto) is prevented.In the present exemplary embodiment, the thickness of the abutting portion 44C of the W pawl 44 in the axial direction is set thinner than the thickness of the circumferential direction intermediate portion 44D of the W pawl 44 in the axial direction, such that the strength of the abutting portion 44C of the W pawl 44 is lower than the strength of the circumferential direction intermediate portion 44C of the W pawl 44. Thus, when the abutting portion 44C (abutting surface S 1) of the W pawl 44 is pressed onto the abutting portion 70B (abutting surface S 2) of the limit cover 70, the abutting portion 44C of the W pawl 44 can easily flex outward with respect to the radial direction. When the abutting portion 44C of the W pawl 44 bends outward in the radial direction in this manner, the contact angle θ of both surfaces at the contact point between the abutting portion 44C (abutting surface S 1) of the W pawl 44 and the abutting portion 70B (abutting surface S 2) of the limit cover 70 is further increased. Thereby, the abutting portion 44C (abutting surface S 1) of the W pawl 44 and the abutting portion 70B (abutting surface S 2) of the limit cover 70 can more easily perform the contact sliding, thereby further preventing the input of an excessive load from the W pawl 44 to the (onto) limit body 66.Further, in the present exemplary embodiment, a portion of the abutting surface S 1 of the W pawl 44 is curved (bent) with the radius of curvature R 1 that is smaller than the radius of curvature R 2 of the abutting surface S 2 of the limit cover 70. this enables reduction of the frictional force between the portion curved with the radius of curvature R 1 on the abutting surface S 1 of the W pawl 44 and the abutting surface S 2 of the limit cover 70. this enables the W pawl 44 to further escape from the limit cover 70, thereby further preventing input of an excessive load from the W pawl 44 to the limit body (the) 66.Note that, in the present exemplary embodiment, an example in which a portion of the abutting surface S 1 of the W pawl 44 is curved with the radius of curvature R 1 smaller than the radius of curvature R 2 of the abutting surface S 2 of the limit cover 70 has been explained; however, the present invention is not limited thereto. Whether or not a portion of the abutting surface S 1 of the W pawl 44 or the entire abutting surface S 1 of the W pawl 44 having the radius of curvature R 1 that is smaller than the radius of curvature R 2 of the abutting surface S 2 of the limit cover 70 is curved (bent) can be set appropriately in consideration of an allowable value of the force with which the W pawl 44 presses the limit cover 70, and the like.In the present exemplary embodiment, an example in which the strength of the abutting portion 44C of the W pawl 44 is set to be lower than the strength of the circumferential direction intermediate portion 44D of the W pawl 44 has been explained; however, the present invention is not limited thereto. Whether or not the strength of the abutting portion 44C of the W pawl 44 is set lower than the strength of the circumferential direction intermediate portion 44D of the W pawl 44 can be set appropriately in consideration of an allowable value of the force with which the W pawl 44 presses the limit cover 70, and the like.An exemplary embodiment is explained above; however, the present invention is not limited thereto, and various other modifications may be made within the scope of the invention as defined in the claims.A webbing device 10 includes a pulley 20 capable of receiving a webbing 22 worn by an occupant, a V-gear 38 capable of rotating with a rotation of the pulley 22 associated therewith, a pawl 26 operated to limit (prevent) rotation of the pulley 20 in a pulling-out direction, and a W-pawl 44 provided on the V-gear 38 that is displaced and causes the pawl 26 to be operated when the V-gear 38 is rotated in the pulling-out direction at a specific speed or a greater speed. The webbing take-up device 10 further includes a restricting body 66 that is moved to an permitting position that permits displacement of the W pawl 44 when the V gear 38 is rotated in the extraction direction and that is moved to a restricting position that permits the W pawl 44 to abut when the V gear 38 is rotated in a take-up direction, wherein the displacement of the W pawl 44 is restricted (prevented) by the abutment of the W pawl 44, and wherein a contact angle with the W pawl 44 is set to 90° or greater.

Claims

A webbing take-up device (10) comprising: a take-up shaft (20) capable of taking up a webbing (22) worn by an occupant, which is rotated in a take-up direction (A) to take up the webbing (22), and which is rotated in a pull-out direction (B) by the pulling-out of the webbing (22); a rotating body (38) capable of rotating in association with rotation of the take-up shaft (20); a restricting member (26) that restricts rotation of the take-up shaft (20) in the pull-out direction (B) by the restricting member (26) by being caused to operate; an operation member (44) provided on the rotating body (38) and displaced to cause operation of the restriction member (26) when the rotating body (38) is rotated in the pulling-out direction (B) at a specific speed or higher speed; and a restriction body (66) moved to an permitting position that permits displacement of the operation member (44) when the rotating body (38) is rotated in the pulling-out direction (B) and moved to a restricting position that permits the operation member (44) to abut on the restriction body (66) when the rotating body (38) is rotated in the receiving direction (A), wherein the restriction body (66) restricts displacement of the operation member (44) by the abutment of the operation member (44) on the restriction body (66), wherein a contact angle (θ) of the restriction body (66) and the operation member (44) is set to 90° or more, and wherein a strength of the operation member (44) at a position lying on a restriction body side is set to be lower than a strength of the operation member (44) at a position lying farther from the restriction body (66) than the position lying on the restriction body side of the operation member (44).The webbing take-up device (10) according to claim 1, wherein: a limitation on the displacement of the operation member (44) by the limitation body (66) is released by the operation member (44) and the limitation body (66) performing contact sliding; and at least a part of a surface of the operation member (44) performing contact sliding with the limitation body (66) is curved with a smaller radius than a radius of a surface of the limitation body (66) performing contact sliding with the operation member (44).

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