JP2017035950A - Webbing tinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a webbing winder which can continue increase in an absorption amount of a torque of a spool in association with increase in a rotation amount of the spool.SOLUTION: In a webbing winder 10, a rotary member 44 is connected to a spool 18 at a time of vehicle emergency, and the rotary member 44 is rotated together with the spool 18. Consequently, a part of a torque of the spool 18 can be continuously absorbed by a friction force generated between a slide contact part 56 of the rotary member 44 and a first stationery plate part 40 of a stationery member 38, and an absorption amount of rotational energy of the spool 18 can be continuously increased in association with a rotation amount of the rotary member 44.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a webbing take-up device that can absorb a part of a rotational force in a pull-out direction of a spool by a frictional force.

  In a vehicle emergency, there is a webbing take-up device in which a spring provided separately from a torsion bar is deformed according to the amount of rotation in the pull-out direction of the spool and a part of the rotational force of the spool is absorbed by the load generated thereby (an example) (See Patent Document 1 below). However, when the deformation of the spring enters the plastic region from the elastic region, the increase in load due to the deformation of the spring is reduced or terminated.

Special table 2014-533627 gazette

  In view of the above fact, an object of the present invention is to obtain a webbing take-up device capable of continuing to increase the amount of absorption of the rotational force of the spool accompanying the increase in the amount of rotation of the spool.

  The webbing take-up device according to claim 1 is a spool that is rotated in a pulling-out direction when the webbing of the seat belt device is pulled out, and a first that is movable in accordance with the rotation of the spool in the pulling-out direction in a vehicle emergency. A member, and a second member that is in contact with the first member at least in the event of a vehicle emergency and continuously generates a frictional force with the first member by the movement of the first member.

  According to the webbing take-up device of the first aspect, when the first member is moved along with the rotation of the spool in the pulling-out direction in a vehicle emergency, a frictional force is generated between the first member and the second member. Then, a part of the rotational force in the pull-out direction of the spool is absorbed by this frictional force. Here, the frictional force generated between the first member and the second member is continuously generated with respect to the movement of the first member. As a result, the amount of energy absorbed by the rotation of the spool can be continuously increased as the amount of rotation in the pull-out direction of the spool increases.

  The webbing take-up device according to claim 2 is the webbing take-up device according to claim 1, wherein at least one of the first member and the second member is between the first member and the second member. It is expanded to the other side of the first member and the second member by frictional heat generated by the friction.

  According to the webbing take-up device of claim 2, at least one of the first member and the second member is caused by frictional heat generated by friction between the first member and the second member. Inflated to the other side of the member. Thereby, the force generated between the first member and the second member can be increased. As a result, the amount of absorption of rotational force in the spool pull-out direction can be increased.

  The webbing take-up device according to claim 3 is the webbing take-up device according to claim 1 or 2, wherein the first member is connected to the spool in a vehicle emergency and is proportional to the rotational speed of the spool. The second member is brought into contact with the side surface in the rotation axis direction of the first member.

  According to the webbing take-up device of the third aspect, the first member is connected to the spool in an emergency of the vehicle and rotated at a rotation speed proportional to the rotation speed of the spool, and the second member is rotated by the first member. Abutted on the axial side surface. Accordingly, the contact area of the second member with respect to the first member can be increased without particularly increasing the size of the first member and the second member along the rotation axis direction of the first member. The amount of rotation energy absorbed by the frictional force between the two members can be increased.

  The webbing take-up device according to claim 4 is the webbing take-up device according to any one of claims 1 to 3, wherein the first member is connected to the spool in an emergency of the vehicle, and the spool The second member is brought into contact with a circumferential surface along the circumferential direction of the first member.

  According to the webbing take-up device of the fourth aspect, the first member is connected to the spool in a vehicle emergency and rotated at a rotation speed proportional to the rotation speed of the spool, and the second member is rotated by the first member. It abuts on the circumferential surface along the circumferential direction. Accordingly, the contact area between the first member and the second member can be increased without increasing the shapes of the first member and the second member along the rotation axis direction of the first member, and the first member and the second member can be increased. The amount of absorption of the energy of rotation of the spool that is absorbed by the frictional force between the members can be increased.

  The webbing take-up device according to claim 5 is the webbing take-up device according to any one of claims 1 to 4, wherein the spool is rotatably supported directly or indirectly, and The second member includes a frame to which the second member is fixed directly or indirectly.

  According to the webbing take-up device of the fifth aspect, the second member is directly or indirectly fixed to the frame on which the spool is rotatably supported directly or indirectly. For this reason, by managing the positional accuracy of the first member relative to the frame, it becomes easy to manage the positional accuracy of the second member relative to the first member.

  As described above, according to the present invention, the increase in the amount of absorption of the rotational force of the spool accompanying the increase in the amount of rotation of the spool can be continued.

It is front sectional drawing of the clutch mechanism and friction force limiter mechanism of the webbing winding device concerning a 1st embodiment. It is a disassembled perspective view of a clutch mechanism and a friction force limiter mechanism. It is a side view of a clutch mechanism and a friction force limiter mechanism. It is a front view of the webbing winding device concerning a 1st embodiment. It is front sectional drawing of the clutch mechanism and friction force limiter mechanism of the webbing winding device concerning a 2nd embodiment. It is front sectional drawing of the clutch mechanism and friction force limiter mechanism of the webbing winding device concerning a 3rd embodiment.

  Next, each embodiment of the present invention will be described with reference to FIGS. In each figure, an arrow FR indicates the vehicle front side to which the webbing take-up device 10 is applied, an arrow OUT indicates the vehicle width direction outer side, and an arrow UP indicates the vehicle upper side. Further, in describing each of the following embodiments, the same reference numerals are given to the same parts as those in the previous embodiment, and detailed description thereof is given. Omitted.

<Configuration of First Embodiment>
As shown in FIG. 4, the webbing take-up device 10 includes a frame 12. The frame 12 is fixed to a vehicle body (both not shown) on the vehicle rear side of the rear seat of the vehicle to which the webbing take-up device 10 is applied. The frame 12 includes a pair of leg plates 14 and 16, and the leg plates 14 and 16 are opposed to each other in the vehicle width direction. The frame 12 is provided with a spool 18. The spool 18 is formed in a substantially cylindrical shape. The axial direction of the spool 18 is along the vehicle width direction, and the spool 18 is rotatable around the central axis (the directions of arrows A and B in FIGS. 2 and 3).

  The longitudinal base end portion of the long belt-like webbing 20 is locked to the spool 18, and when the spool 18 is rotated in the winding direction (the direction of arrow A in FIGS. 2 and 3), the webbing 20 It is wound on the spool 18 from the longitudinal base end side. Further, the front end side in the longitudinal direction of the webbing 20 is drawn from the spool 18 to the front side of the vehicle. The webbing 20 pulled out from the spool 18 extends to the vehicle lower side along the seat back through the vehicle upper side of the seat back of the rear seat on the outer side in the vehicle width direction of the seating position of the occupant in the rear seat, and the seat back and the seat of the rear seat It passes between the cushions (both not shown). Moreover, the longitudinal direction front-end | tip part of the webbing 20 is latched by the anchor plate (illustration omitted). The anchor plate is formed of a metal plate material such as iron, and is fixed to a vehicle body such as a floor portion of the vehicle below the seat cushion of the rear seat.

  The vehicle seat belt device to which the webbing retractor 10 is applied includes a buckle device (not shown). The buckle device is provided on the inner side in the vehicle width direction of the seating position of the occupant on the rear seat. The webbing 20 is mounted on the body of the occupant by engaging the tongue (not shown) provided on the webbing 20 with the buckle device in a state where the webbing 20 is wound around the body of the occupant seated on the rear seat. .

  On the other hand, as shown in FIG. 4, a torsion bar 22 as a rotational force absorbing member of the first force limiter mechanism is provided inside the spool 18. The torsion bar 22 includes a torsion part 24 as a rotational force absorbing part. The torsion part 24 has a long rod shape in the vehicle width direction, and a spool side engagement part 26 is formed on the outer side of the torsion part 24 in the vehicle width direction. The spool side engaging portion 26 is prevented from rotating relative to the spool 18 inside the spool 18.

  Further, a lock mechanism 28 as a lock means is provided on the inner side in the vehicle width direction of the leg plate 14 of the frame 12. The lock mechanism 28 is activated in a vehicle emergency. When the lock mechanism 28 is activated, the lock mechanism 28 prevents rotation of the inner portion of the torsion bar 22 in the vehicle width direction in the pull-out direction (the direction of arrow B in FIGS. 2 and 3), and the spool 18 is pulled in the pull-out direction. Rotation is prevented.

  Further, a pretensioner 30 is provided between the leg plate 14 of the frame 12 and the lock mechanism 28. The pretensioner 30 is activated in a vehicle emergency. When the pretensioner 30 is actuated, the inner portion of the torsion bar 22 in the vehicle width direction is rotated by the pretensioner 30 in the winding direction (the direction of arrow A in FIGS. 2 and 3). As a result, the spool 18 is rotated in the winding direction.

  On the other hand, an urging mechanism 32 is provided outside the leg plate 16 of the frame 12 in the vehicle width direction. The biasing mechanism 32 includes biasing means such as a spiral spring (not shown). The urging means is directly or indirectly engaged with the shaft portion 50 extending outward in the vehicle width direction from the spool side engaging portion 26 of the torsion bar 22, and the urging means is spooled via the torsion bar 22. 18 is connected. The spool 18 is biased in the winding direction (the direction of arrow A in FIGS. 2 and 3) by the biasing force of the biasing means.

  Further, a friction force limiter mechanism 34 and a clutch mechanism 36 as a second force limiter mechanism are provided between the leg plate 16 of the frame 12 and the biasing mechanism 32. As shown in FIG. 2, the friction force limiter mechanism 34 includes a pair of fixing members 38 as second members. These fixing members 38 are formed of metal such as iron and are fixed to the leg plates 16 of the frame 12 so as to face each other in the vehicle front-rear direction across the central axis of the spool 18 on the outside of the leg plates 16 of the frame 12. .

  Each fixing member 38 includes a pair of fixed first plate portions 40. The fixed first plate portion 40 is formed in a plate shape whose thickness direction is along the axial direction of the spool 18. In the fixed first plate portion 40, the radially inner portion and the radially outer portion centering on the central axis of the spool 18 are curved with the central axis of the spool 18 as the center of curvature. The pair of fixed first plate portions 40 are disposed to face each other in the axial direction of the spool 18, and the radially outer portions of the fixed first plate portions 40 are connected by the fixed second plate portion 42. .

  The fixed second plate portion 42 is formed in a narrow plate shape whose thickness direction is along the radial direction of the fixed first plate portion 40, and both side surfaces in the thickness direction of the fixed second plate portion 42 are formed on the spool 18. It is curved with the center axis of the center of curvature as the center of curvature. For this reason, the cross-sectional shape obtained by cutting the fixing member 38 in the radial direction of the fixed first plate portion 40 is a concave shape opened toward the inside in the radial direction of the fixed first plate portion 40.

  The friction force limiter mechanism 34 includes a rotating member 44 as a first member. The rotating member 44 includes a clutch ring 46. The clutch ring 46 is formed in a substantially cylindrical shape, and is disposed coaxially with the central axis of the spool 18. Further, the one axial side portion (the inner side portion in the vehicle width direction) of the clutch ring 46 is rotatably held by the fixed first plate portion 40 on the inner side in the vehicle width direction of both the fixing members 38.

  A clutch base 48 that constitutes the clutch mechanism 36 is disposed inside the clutch ring 46. The clutch base 48 is directly or indirectly connected to the shaft portion 50 of the torsion bar 22, and the clutch base 48 is rotated together with the shaft portion 50 of the torsion bar 22. A pair of clutch members 52 are provided on the clutch base 48. These clutch members 52 can rotate with respect to the clutch base 48 in the clutch engagement direction (in the direction of arrow C in FIGS. 2 and 3), but in a normal state, the clutch member 52 rotates in the clutch engagement direction. The movement is blocked by a clutch holding mechanism (not shown).

  For example, when the above-described lock mechanism 28 is operated and the vehicle width direction outer side portion is rotated relative to the vehicle width direction inner side portion of the torsion portion 24 of the torsion bar 22 in the pulling direction, the clutch holding mechanism of the clutch mechanism 36 The rotation preventing state of the clutch member 52 is released, and the clutch member 52 is rotated in the clutch coupling direction. Thus, when the clutch member 52 is rotated in the clutch connecting direction, the clutch member 52 is engaged with the inner portion of the clutch ring 46, and the clutch ring 46 is connected to the clutch base 48 by the clutch member 52. In this state, when the clutch base 48 is rotated in the pull-out direction, the clutch ring 46 is rotated together with the clutch base 48 in the pull-out direction.

  On the other hand, an expansion portion 54 is provided outside the clutch ring 46. The inflating part 54 is formed in a substantially disc shape and is provided coaxially with the clutch ring 46. The expansion part 54 is formed of a material having a relatively high linear expansion coefficient. Sliding contact portions 56 are provided on both sides in the axial direction of the inflating portion 54. The slidable contact portion 56 is formed in a substantially disc shape and is provided coaxially with the clutch ring 46. The surface of the sliding contact portion 56 opposite to the expansion portion 54 is in sliding contact with the fixed first plate portion 40 of the fixing member 38, and when the rotating member 44 is rotated, the sliding contact portion 56 of the rotating member 44. And the fixed first plate portion 40 of the fixing member 38, friction is generated, thereby generating frictional heat Q. When the frictional heat Q generated between the sliding contact portion 56 and the fixed first plate portion 40 is transmitted to the expanding portion 54 of the rotating member 44 through the sliding contact portion 56, the expanding portion 54 is expanded, and the sliding contact portion is expanded. 56 is pressed toward the fixed first plate portion 40 side.

<Operation and Effect of First Embodiment>
In the webbing take-up device 10, the tongue provided on the webbing 20 is engaged with the buckle device in a state where the webbing 20 pulled out from the spool 18 by the passenger seated on the rear seat of the vehicle is hooked on the body of the passenger. By being combined, the webbing 20 is put on the occupant's body.

  In the event of a vehicle emergency such as a vehicle collision, the lock mechanism 28 is activated, the lock mechanism 28 prevents rotation of the inner portion of the torsion bar 22 in the vehicle width direction, and the spool 18 is prevented from rotating in the pull-out direction. The As a result, the webbing 20 is prevented from being pulled out of the spool 18, and the inertial movement of the occupant toward the front of the vehicle is prevented or suppressed by the webbing 20.

  On the other hand, when the occupant attempts to move to the front side of the vehicle, the webbing 20 is pulled by the occupant. When the tensile force applied to the webbing 20 exceeds the mechanical strength of the torsion part 24 of the torsion bar 22, the outer part in the vehicle width direction of the torsion part 24 of the torsion bar 22 extends in the pull-out direction with respect to the inner part in the vehicle width direction. Deformed to twist. A part of the tensile force applied to the webbing 20 is subjected to torsional deformation of the torsion part 24 of the torsion bar 22 and absorbed.

  In addition, when the torsion portion 24 of the torsion bar 22 is twisted and deformed in this way and the outer portion in the vehicle width direction of the torsion portion 24 is rotated relative to the inner portion in the vehicle width direction in the pull-out direction, the clutch mechanism 36 is activated. Is done. When the clutch mechanism 36 is operated, the rotation preventing state of the clutch member 52 by the clutch holding mechanism (not shown) of the clutch mechanism 36 is released, and the clutch member 52 is engaged with the clutch base 48 in the clutch connecting direction (see FIG. It is rotated in the direction of arrow C in FIG.

  When the clutch member 52 is thus rotated in the clutch coupling direction, the clutch member 52 is engaged with the inner portion of the clutch ring 46 of the rotating member 44 of the friction force limiter mechanism 34. As a result, the clutch base 48 and the clutch ring 46 are connected by the clutch member 52. In this state, the clutch base 48 is rotated in the pull-out direction by the rotation of the outer portion in the vehicle width direction with respect to the inner portion in the vehicle width direction in the torsion portion 24 of the torsion bar 22 in the pull-out direction (arrow B direction in FIGS. 2 and 3). Then, the rotating member 44 is rotated in the pulling direction together with the clutch base 48.

  When the rotating member 44 is thus rotated in the pull-out direction, friction is generated between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38. The friction generated between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38 becomes a resistance to rotation of the spool 18 in the pulling direction, and the spool 18 is pulled in the pulling direction. A part of the rotational force is provided and absorbed by the frictional force generated between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38. Here, the energy received by the friction between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38 continuously increases in proportion to the rotational speed of the rotating member 44. For this reason, the amount of energy absorbed by the rotation of the spool 18 in the pull-out direction can be continuously increased in proportion to the rotational speed of the rotating member 44.

  Further, the frictional heat Q generated by the friction between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38 is the amount of rotation in the pull-out direction of the spool 18, that is, the rotating member 44. It becomes larger in accordance with the increase in the amount of webbing 20 drawn from the spool 18 after the start of rotation in the drawing direction. Furthermore, when the frictional heat Q generated in this way is transmitted to the expanding portion 54 of the rotating member 44 via the sliding contact portion 56 of the rotating member 44, the expanding portion 54 is expanded. As a result, the slidable contact portion 56 is pressed against the fixed first plate portion 40 of the fixing member 38, so that the frictional resistance between the slidable contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixed member 38 is reduced. Can be big. As a result, the resistance of rotation in the pulling-out direction of the spool 18 due to friction between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38 is determined as the pulling amount of the webbing 20 from the spool 18. It can be increased according to the increase.

  Thus, for example, when the occupant's physique is small and the amount of inertial movement to the front of the vehicle in a vehicle emergency is small, the load on the occupant's body from the webbing 20 can be reduced, and the occupant's physique is large. When the amount of inertial movement toward the front side of the vehicle in an emergency is large, the restraining force of the occupant's body by the webbing 20 can be increased according to the increase in the occupant's movement amount.

  Further, the increase in the frictional heat Q can be continued from the start of the rotation of the rotating member 44 in the drawing direction, and the increase in the frictional heat Q is prevented from being completed during the rotation of the rotating member 44 in the drawing direction. it can.

  Further, in the present embodiment, the sliding contact portions 56 of the rotating member 44 are provided on both sides in the axial direction of the rotating member 44. Therefore, the contact area between the sliding contact portion 56 of the rotating member 44 and the fixed first plate portion 40 of the fixing member 38 can be increased without increasing the size of the rotating member 44, and the sliding contact portion 56 of the rotating member 44 and the fixing member can be increased. The frictional heat Q generated by the friction with the 38 fixed first plate portions 40 can be increased.

  In the present embodiment, the fixing member 38 is fixed to the leg plate 16 of the frame 12. For this reason, it becomes easy to manage the positional accuracy and the like of the rotating member 44 with respect to the fixed member 38.

<Second Embodiment>
As shown in FIG. 5, the rotating member 44 of the friction force limiter mechanism 34 according to the second embodiment does not include the expansion portion 54 and the sliding contact portion 56, and instead, a disk-shaped flange portion 58. It has. The flange portion 58 extends outward in the radial direction of the clutch ring 46 from an intermediate portion in the central axis direction of the clutch ring 46 at the outer peripheral portion of the clutch ring 46.

  In the present embodiment, the fixing member 38 is provided with the expansion portion 54 and the sliding contact portion 56. In the present embodiment, the expanding portion 54 and the sliding contact portion 56 have substantially the same shape as the fixed first plate portion 40 of the fixing member 38, and the expanding portion 54 is formed on the inner side of the fixing member 38 (both fixed first plates). (Between the first plate portion 40) and the fixed first plate portion 40 of the fixing member 38. The sliding contact portion 56 is provided integrally with the inflating portion 54 on the opposite side of the inflating portion 54 from the fixed first plate portion 40 (inside the fixing member 38). The flange portion 58 of the rotating member 44 is sandwiched from both sides in the axial direction by the sliding contact portion 56 on the plate portion 40 side and the sliding contact portion 56 on the other fixed first plate portion 40 side.

  In the present embodiment, when the rotating member 44 is rotated in the pull-out direction together with the spool 18, the sliding contact portion 56 provided in the fixed first plate portion 40 of the fixing member 38 and the flange portion 58 of the rotating member 44. Friction occurs between them. This friction becomes resistance to rotation of the spool 18 in the pulling direction, and part of the rotational force in the pulling direction of the spool 18 is between the sliding contact portion 56 of the fixing member 38 and the flange portion 58 of the rotating member 44. It is subjected to the generated frictional force and absorbed.

  Further, in this way, the frictional heat Q generated by the friction between the sliding contact portion 56 of the fixing member 38 and the flange portion 58 of the rotating member 44 is fixed to the fixing member 38 via the sliding contact portion 56. When transmitted to the expansion part 54 provided in the plate part 40, the expansion part 54 is expanded. As a result, the sliding contact portion 56 is pressed against the flange portion 58 of the rotating member 44.

  Therefore, in the present embodiment, the resistance of the rotation of the spool 18 in the pulling-out direction due to the friction between the sliding contact portion 56 of the fixing member 38 and the flange portion 58 of the rotating member 44 is determined as the webbing 20 from the spool 18. It can be increased as the withdrawal amount increases.

  Thus, for example, when the occupant's physique is small and the amount of inertial movement to the front of the vehicle in a vehicle emergency is small, the load on the occupant's body from the webbing 20 can be reduced, and the occupant's physique is large. When the amount of inertial movement toward the front side of the vehicle in an emergency is large, the restraining force of the occupant's body by the webbing 20 can be increased according to the increase in the occupant's movement amount.

  Further, the generation of the frictional heat Q can be continuously increased from the start of the rotation of the rotating member 44 in the drawing direction, and the increase of the frictional heat Q is completed during the rotation of the rotating member 44 in the drawing direction. Can be prevented.

  Further, in the present embodiment, the sliding contact portion 56 of the fixing member 38 is brought into contact with the flange portion 58 of the rotating member 44 from the axial direction side of the rotating member 44. Therefore, the contact area between the sliding contact portion 56 of the fixing member 38 and the flange portion 58 of the rotating member 44 can be increased without increasing the size of the rotating member 44, and the sliding contact portion 56 of the fixing member 38 and the flange of the rotating member 44 can be increased. The frictional heat Q generated by the friction with the portion 58 can be increased.

<Third Embodiment>
As shown in FIG. 6, in the rotating member 44 of the friction force limiter mechanism 34 according to the third embodiment, a sliding contact portion 56 is formed on the radially outer side of the expanding portion 54. The sliding contact portion 56 has a circular shape, and is provided integrally with the inflating portion 54 on the same axis as the inflating portion 54. The outer peripheral surface of the sliding contact portion 56 is in sliding contact with the fixed second plate portion 42 of the fixing member 38 inside the fixing member 38.

  In the present embodiment, when the rotating member 44 is rotated in the pull-out direction together with the spool 18, friction is generated between the sliding contact portion 56 of the rotating member 44 and the fixed second plate portion 42 of the fixing member 38. This friction becomes resistance to rotation of the spool 18 in the pull-out direction, and part of the rotational force in the pull-out direction of the spool 18 is caused by the sliding contact portion 56 of the rotating member 44 and the fixed second plate portion 42 of the fixing member 38. Is absorbed by the frictional force generated between the two.

  Furthermore, the frictional heat Q generated between the sliding contact portion 56 of the rotating member 44 and the fixed second plate portion 42 of the fixing member 38 in this way is expanded through the sliding contact portion 56. When transmitted to 54, the expansion part 54 is expanded. As a result, the sliding contact portion 56 is pressed against the fixed second plate portion 42 of the fixing member 38.

  Therefore, in the present embodiment, the resistance of rotation in the pulling-out direction of the spool 18 due to friction between the sliding contact portion 56 of the rotating member 44 and the fixed second plate portion 42 of the fixing member 38 is reduced from the spool 18. The webbing 20 can be increased in accordance with the amount of withdrawal.

  Thus, for example, when the occupant's physique is small and the amount of inertial movement to the front of the vehicle in a vehicle emergency is small, the load on the occupant's body from the webbing 20 can be reduced, and the occupant's physique is large. When the amount of inertial movement toward the front side of the vehicle in an emergency is large, the restraining force of the occupant's body by the webbing 20 can be increased according to the increase in the occupant's movement amount.

  Further, the generation of the frictional heat Q can be continuously increased from the start of the rotation of the rotating member 44 in the drawing direction, and the generation of the frictional heat Q is increased during the rotation of the rotating member 44 in the drawing direction. Can be prevented from ending.

  Furthermore, in the present embodiment, a sliding contact portion 56 is provided on the outer peripheral portion of the rotating member 44. Therefore, by increasing the axial dimension of the rotating member 44, the contact area between the sliding contact portion 56 and the fixed second plate portion 42 of the fixing member 38 can be increased without increasing the radial dimension of the rotating member 44. The frictional heat Q generated by the friction between the sliding contact portion 56 of the rotating member 44 and the fixed second plate portion 42 of the fixing member 38 can be increased.

  In the first embodiment and the second embodiment described above, the sliding contact portion 56 and the fixed first plate portion 40 of the fixing member 38 slidably contacting the sliding contact portion 56 or the flange portion 58 of the rotating member 44 are provided. Is configured to be slidably contacted from both axial sides of the rotating member 44. However, the sliding contact portion 56 and the fixed first plate portion 40 of the fixing member 38 that is in sliding contact with the sliding contact portion 56 or the flange portion 58 of the rotating member 44 are in sliding contact from one axial side of the rotating member 44. Also good.

  Further, in the first embodiment and the second embodiment described above, the fixing member 38 is provided separately from the frame 12. However, for example, the frame 12 is the second member, the surface of the rotating member 44 on the leg plate 16 side of the frame 12 is in sliding contact with the leg plate 16, and the rotating member 44 is rotated to rotate the rotating member 44 and the leg plate 16 of the frame 12. It is good also as a structure which friction produces between.

  Further, in each of the above-described embodiments, when the inflating portion 54 is inflated, the sliding contact portion 56 becomes the fixed first plate portion 40 of the fixing member 38, the flange portion 58 of the rotating member 44, or the fixing member 38. It was the structure pressed by the 2 plate part 42. FIG. However, for example, the fixed first plate portion 40 or the fixed second plate portion 42 of the fixing member 38 is configured to be movable toward the rotating member 44, and the fixed first plate portion 40 or the fixed second plate portion is biased by a biasing means such as a spring. It is good also as a structure by which the plate part 42 is pressed to the rotation member 44 side.

  Further, in each of the above-described embodiments, the spool 18 and the rotating member 44 are engaged with each other when the outer portion in the vehicle width direction is relatively rotated in the pull-out direction with respect to the inner portion in the vehicle width direction of the torsion portion 24 of the torsion bar 22. The structure is connected by the mechanism 36. However, for example, the spool 18 and the rotating member 44 may be connected by the clutch mechanism 36 when the spool 18 is rotated in the pull-out direction after the pretensioner 30 is operated. With such a configuration, it is possible to prevent the friction force limiter mechanism 34 from operating at the time of a light collision such that the pretensioner 30 is not operated. Thus, the timing at which the spool 18 and the rotating member 44 are coupled is limited to the case where the outer portion in the vehicle width direction is relatively rotated in the pull-out direction with respect to the inner portion in the vehicle width direction of the torsion portion 24 of the torsion bar 22. Is not to be done.

  Further, in each of the above embodiments, when the clutch member 52 of the clutch mechanism 36 is engaged with the inner portion of the clutch ring 46 of the rotating member 44, the rotating member 44 is rotated integrally with the spool 18. there were. However, for example, when a speed change means including a gear train or the like is provided between the clutch mechanism 36 and the rotation member 44, the spool 18 rotates when the spool 18 is rotated in the pull-out direction in the operating state of the clutch mechanism 36. May be increased or decelerated and transmitted to the rotating member 44, and the rotating member 44 may be rotated at a rotation speed proportional to the rotation speed of the spool 18.

  In each of the above embodiments, the fixing member 38 as the second member is fixed to the leg plate 16 of the frame 12. However, for example, when the rotating member 44 is rotated, the second member may be rotated in the opposite direction to the rotating member 44, and the second member is fixed to the frame 12 or the like. It is not limited.

  Further, in each of the above embodiments, the rotating member 44 is the first member, and the movement of the first member is the rotation of the rotating member 44. However, the movement of the first member may be configured such that, for example, the first member slides linearly in conjunction with the rotation of the spool 18 in the pull-out direction in the event of a vehicle emergency. It is not limited to rotation.

10 Webbing take-up device 12 Frame 18 Spool 20 Webbing 38 Fixing member (second member)
44 Rotating member (first member)

Claims (5)

A spool that is rotated in the pull-out direction by pulling out the webbing of the seat belt device;
A first member movable in accordance with rotation of the spool in a pull-out direction in a vehicle emergency;
A second member that is brought into contact with the first member at least in the event of a vehicle emergency and in which a frictional force is continuously generated between the first member and the movement of the first member;
A webbing take-up device comprising:   At least one of the first member and the second member is expanded to the other side of the first member and the second member by frictional heat generated by friction between the first member and the second member. The webbing take-up device according to claim 1.   The first member is connected to the spool in an emergency of the vehicle, is rotated at a rotation speed proportional to the rotation speed of the spool, and the second member is in contact with a side surface in the rotation axis direction of the first member. The webbing take-up device according to claim 1 or 2.   The first member is connected to the spool in an emergency of the vehicle, and is rotated at a rotation speed proportional to the rotation speed of the spool, and the second member is in contact with a circumferential surface along the rotation circumferential direction of the first member. The webbing take-up device according to any one of claims 1 to 3, wherein the webbing take-up device is any one of claims 1 to 3.   The webbing take-up according to any one of claims 1 to 4, further comprising a frame on which the spool is directly or indirectly rotatably supported and the second member is directly or indirectly fixed. apparatus.