JP3958172B2 - Webbing take-up device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a webbing take-up device.
[0002]
[Prior art]
As a conventional webbing take-up device, a vehicle seat belt device (Patent Document 1) is known as shown in FIG. In the figure, arrow FR indicates the vehicle longitudinal direction, arrow UP indicates the vehicle upper direction, and arrow W indicates the vehicle width direction.
[0003]
The webbing retractor 100 includes a frame 120, and the frame 120 includes a pair of opposing leg plates 122 and 124 and a back plate 126 that connects the leg plates 122 and 124, and is formed in a substantially U shape. . The back plate 126 is bolted to the vehicle body, and the webbing retractor 100 is attached with the opposing direction of the leg plates 122 and 124 being the vehicle front-rear direction.
[0004]
An axial spool 102 having a circular cross section is suspended between the leg plates 122 and 124 with the opposing direction of the leg plates 122 and 124 as the axial direction. Both ends of the spool 102 in the axial direction are supported by the leg plates 14 and 16 and are rotatable around the axis (uniaxial line J). An occupant restraining webbing 128 is wound around the outer periphery of the spool 102, and the webbing 128 is wound up by rotation in one direction around the axis J of the spool 102 (shown by an arrow CW). The webbing 128 is pulled out by rotation in the opposite direction (shown by the arrow AC). A mainspring spring (not shown) is provided at one end of the spool 102. According to the spring, the spool 102 is urged to rotate in the webbing take-up direction (arrow CW), and the webbing 128 can follow changes in the posture of the occupant.
[0005]
A pretensioner 138 is provided outside the leg plate 122 of the frame 120 via the clutch mechanism 140 at the other end of the spool 102.
[0006]
The pretensioner 138 includes a rotor 104 that can rotate about one axis J. The rotor 104 has a disk shape, and a sleeve 116 is integrally provided on the plate surface opposite to the spool 102 so as to be coaxial with the rotor 104. A pinion gear 132 is fitted and fixed to the outer periphery of the sleeve 116 so that the pinion gear 132 and the rotor 104 can rotate together. A rack 136 is provided corresponding to the pinion gear 132. The rack 136 is engaged with the pinion gear 132, and the vertical movement of the rack 136 is converted into the rotational movement of the pinion gear 132. The rotor 104 is rotated in the webbing take-up direction by moving the rack 136 upward (shown by an arrow UP), and the rotor 104 is rotated in the webbing drawing-out direction (arrow AC) by the downward movement of the rack 136.
[0007]
A lower end portion of the rack 136 is supported by the piston rod 130. When a gas generator (not shown) is activated and a gas pressure is supplied into the cylinder 132 during a vehicle emergency such as when the vehicle suddenly decelerates, the rack 136 is driven to move upward via the piston rod 130.
[0008]
The clutch mechanism 140 includes three rollers 108, 108 and 108. The rollers 108 have a cylindrical shape with the uniaxial line J direction as the axial direction, and are arranged at equal angular intervals around the uniaxial line J by the holding plate 110. A sleeve 114 is provided outside the leg plate 122 of the frame 120 at the other end of the spool 102 corresponding to the roller 108. The sleeve 114 can rotate integrally with the spool 102 around one axis J. A circular hole 118 is formed in the plate surface on the spool 102 side of the rotor 104 corresponding to the sleeve 114, and the sleeve 114 enters the circular hole 118. As shown in FIGS. 15 and 16, three receiving recesses 106, 106, 106 are formed in the inner periphery of the circular hole 118 corresponding to the rollers 108, 108, 108. Each roller 108 is accommodated. The inner periphery of the housing recess 106 is gradually reduced in diameter in the webbing pull-out direction.
[0009]
From the state shown in FIG. 15 where the roller 108 is on the webbing winding direction side of the housing recess 106, when the rotor 104 rotates relative to the roller 108 in the webbing winding direction around the uniaxial line J, the roller 108 has a diameter with respect to the uniaxial line J. It moves inward in the direction, and is sandwiched between the housing recess 106 of the rotor 104 and the sleeve 114 of the spool 102, and can transmit the rotation between the rotor 104 and the spool 102 (clutch operation state shown in FIG. 16).
[0010]
When the rotor 104 rotates relative to the roller 108 in the webbing pull-out direction around the uniaxial line J from the state shown in FIG. 16, the roller 108 moves radially outward relative to the uniaxial line J, and the rotor 104 and the sleeve 114 of the spool 102 Is released, and rotation between the rotor 104 and the spool 102 becomes non-transmitted (clutch release state shown in FIG. 15).
[0011]
When the pretensioner 138 is activated and the rotor 104 is rotated in the webbing take-up direction in a vehicle emergency, the clutch operation is performed, and the spool 102 is forcibly rotated in the webbing take-up direction. The webbing 128 can be tensioned in the passenger restraining direction.
[0012]
After the tension is no longer required, the clutch is released by pulling the webbing 128 in the webbing pull-out direction and causing the rotor 104 to rotate relative to the roller 108 in the webbing pull-out direction.
[0013]
[Patent Document 1]
JP-A-11-247906
[0014]
[Problems to be solved by the invention]
However, when releasing the clutch, the force required for the relative rotation of the rotor 104 with respect to the roller 108 is applied to all three rollers 108 simultaneously. The webbing 128 must be pulled with a strong force in the webbing pull-out direction. In particular, if the gas pressure remains in the cylinder 132, it is necessary to counter it further.
[0015]
In view of the above facts, the present invention has an object to provide a webbing take-up device that realizes clutch release with an appropriate force.
[0016]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a webbing take-up device according to the present invention as set forth in claim 1 comprises a take-up shaft that rotates so that the webbing can be taken up and pulled out, and a rotating member that is rotated by the operation of a pretensioner in the event of a vehicle emergency. And a plurality of clutch members provided between the winding shaft and the rotating member, and the clutch member is moved to the winding shaft side to wind the rotating shaft from the rotating member so as to rotate the winding shaft in the webbing winding direction. Clutch means for transmitting rotational torque to the spindle, clutch releasing means for releasing the clutch by moving the clutch member toward the rotating member, and releasing the clutch at different timings for at least two of the clutch members; It is provided with.
[0017]
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 clutch means moves the clutch member toward the take-up shaft by relative rotation of the rotating member with respect to the clutch member in the webbing take-up direction. The clutch release means is configured to move the clutch member toward the rotary member to release the clutch by relative rotation of the rotary member with respect to the clutch member, and to release the clutch and to rotate the rotary member in the webbing pull-out direction. Accordingly, at least two of the clutch members have blocking means for blocking movement in the webbing pull-out direction at different timings, and at least two of the clutch members are disengaged at different timings.
[0018]
According to a third aspect of the present invention, there is provided the webbing take-up of the present invention according to the second aspect, wherein the blocking means is a unidirectional rotating body that is prevented from rotating in the webbing pull-out direction and is allowed to rotate in the webbing take-up direction. A plurality of recesses formed in the unidirectional rotating body corresponding to the clutch members and engaged with the clutch members, each having a recess-inside dimension for restricting movement of the clutch member in the webbing pull-out direction, The in-recess dimension is characterized by comprising at least two webbing pull-out direction movements in the clutch member and the recesses that differ between the recesses to prevent movement at different timings.
[0019]
According to the above-described configuration, the pretensioner operates in the event of a vehicle emergency such as when the vehicle suddenly decelerates. For example, as in claim 2, the rotating member rotates and the rotating member moves in the webbing winding direction with respect to the clutch member. When the relative rotation occurs, the clutch member moves toward the winding shaft, and rotational torque is transmitted from the rotating member to the winding shaft. The winding shaft rotates in the webbing winding direction, and the webbing can be tensioned in the passenger restraining direction.
[0020]
After the tension is no longer required, for example, as in claim 2, by rotating the rotating member relative to the clutch member in the webbing pull-out direction, the clutch member moves toward the rotating member and the clutch is released. Done. At this time, clutch release is performed at different timings for at least two of the clutch members. That is, first, one clutch member moves to the rotating member side, and then the other clutch member moves to the rotating member side. The force required for releasing the clutch is applied at different timings for at least two of the clutch members.
[0021]
Therefore, the clutch can be released with an appropriate force.
[0022]
For example, the pretensioner is configured to supply a gas pressure into the cylinder and rotate the rotating member using the gas pressure. The webbing is pulled in the webbing pulling direction, and the rotating member is relative to the clutch member in the webbing pulling direction. If the clutch is released by rotating, it is necessary to counter the gas pressure remaining in the cylinder. In this case, the present invention is particularly effective.
[0023]
In order to release the clutch at different timings, for example, the movement of the clutch member in the webbing pull-out direction may be prevented at different timings. First, the movement of one clutch member is blocked, the rotating member rotates relative to the one clutch member in the webbing pull-out direction, the one clutch member moves to the rotating member side, and then the other clutch member The movement is prevented, the rotating member rotates relative to the other clutch member in the webbing pull-out direction, and the other clutch member moves to the rotating member side.
[0024]
In order to prevent movement of the clutch member in the webbing pull-out direction at different timings, for example, as described in claim 3, the in-recess dimensions of the recesses may be made different between the recesses. Even if the one-way rotating body cannot rotate in the webbing pull-out direction and one clutch member cannot move in the webbing pull-out direction, the other clutch member can move in the webbing pull-out direction. Directional movement can be prevented at different times.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
A webbing take-up device according to a first embodiment of the present invention will be described with reference to FIGS. In the figure, arrow FR indicates the vehicle longitudinal direction, arrow UP indicates the vehicle upper direction, and arrow W indicates the vehicle width direction.
[0026]
As shown in FIG. 1, the webbing take-up device 10 includes a frame 12, and the frame 12 includes a pair of opposed leg plates 14 and 16 and a back plate 18 that connects the leg plates 14 and 16. It is formed in a letter shape. The back plate 18 is bolted to the vehicle body, and the webbing retractor 10 is attached with the opposing direction of the leg plates 14 and 16 being the vehicle front-rear direction.
[0027]
An axial spool 20 (first rotating body) having a circular cross section is stretched between the leg plates 14 and 16 with the opposing direction of the leg plates 14 and 16 as the axial direction. Both ends of the spool 20 in the axial direction are supported by the leg plates 14 and 16, and are rotatable around the axis (uniaxial line J). An occupant restraining webbing 24 is wound around the outer periphery of the spool 20, and the webbing 24 is wound up by rotation in one direction around the axis J of the spool 20 (shown by an arrow CW). The webbing 24 is pulled out by rotation in the opposite direction (shown by the arrow AC). A mainspring spring (not shown) is provided at one end of the spool 20. According to the mainspring spring, the spool 20 is urged to rotate in the webbing take-up direction (arrow CW), and the webbing 24 can follow the posture change of the occupant.
[0028]
At the other end of the spool 20, a pretensioner 88 is provided outside the leg plate 14 of the frame 12 via the clutch mechanism 26.
[0029]
The pretensioner 88 includes a rotor 56 (second rotating body) as a rotating member that can rotate about one axis J. The rotor 56 has a disk shape, and a sleeve 58 is integrally provided on the plate surface opposite to the spool 20 so as to be coaxial with the rotor 56. A pinion gear 68 is fitted and fixed to the outer periphery of the sleeve 58, and the pinion gear 96 and the rotor 56 can rotate together. A rack 94 is provided corresponding to the pinion gear 96. The rack 94 is engaged with the pinion gear 96, and the vertical movement of the rack 94 is converted into the rotational movement of the pinion gear 96. The rotor 56 rotates in the webbing take-up direction when the rack 72 moves upward (shown by arrow UP), and the rotor 56 rotates in the webbing pull-out direction (arrow AC) when the rack 94 moves downward.
[0030]
A lower end portion of the rack 94 is supported by the piston rod 92. When a gas generator (not shown) is activated and a gas pressure is supplied into the cylinder 90 in the event of a vehicle emergency such as when the vehicle is suddenly decelerated, the rack 94 is driven to move upward via the piston rod 92.
[0031]
2 and 4, the clutch mechanism 26 includes a first transmission roller 32, a second transmission roller 34, and a third transmission roller 36 (three transmission rollers) as clutch members. The first to third transmission rollers 32, 34, and 36 have a cylindrical shape with the uniaxial line J direction as the axial direction, are spaced along the uniaxial line J direction, and are arranged in the webbing winding direction around the uniaxial line J. The first, second and third transmission rollers are arranged in this order. As shown in FIG. 3, a sleeve 22 as a winding shaft is provided outside the leg plate 14 of the frame 12 at the other end of the spool 20 corresponding to the first to third transmission rollers 32, 34, 36. ing. The sleeve 22 can rotate integrally with the spool 20 around one axis J. A circular hole 30 is formed in the plate surface on the spool 20 side of the rotor 56 corresponding to the sleeve 22. The sleeve 22 enters the circular hole 30.
[0032]
On the inner periphery of the circular hole 30, a first receiving recess 60, a second receiving recess 62, and a third receiving recess 64 serving as clutch means correspond to the first to third transmission rollers 32, 34, and 36. Is recessed radially outward. First to third transmission rollers 32, 34, and 36 are accommodated in the first to third accommodation recesses 60, 62, and 64, respectively. In the first to third receiving recesses 60, 62 and 64, the first to third transmission rollers 32, 34 and 36 can move relative to the rotor 56 around the uniaxial line J. The inner circumferences of the first to third receiving recesses 60, 62, 64 are gradually made smaller in the webbing pull-out direction.
[0033]
From the state shown in FIG. 4 in which the first to third transmission rollers 32, 34, and 36 are located on the webbing winding direction side of the first to third receiving recesses 60, 62, and 64, the rotor 56 is wound around the uniaxial line J. When the first to third transmission rollers 32, 34, and 36 move relative to the first to third transmission rollers 32, 34, and 36 in the webbing winding direction around the uniaxial line J, the first to third transmission rollers 32, 34, and 36 move to the uniaxial line J. (In the proximity direction to the outer periphery of the sleeve 22 (moves toward the sleeve 22)). The first to third transmission rollers 32, 34, and 36 are sandwiched between the inner periphery of the first to third receiving recesses 60, 62, and 64 of the rotor 56 and the outer periphery of the sleeve 22 of the spool 20. 20 moves around one axis J integrally with the sleeve 22 and can transmit the rotation between the rotor 56 and the sleeve 22 of the spool 20 (rotational torque is transmitted from the rotor 56 to the spool 22 of the spool 20). 5), the webbing 24 can be tensioned in the occupant restraint direction. The first to third transmission rollers 32, 34, and 36 are located on the webbing pull-out direction side of the first to third housing recesses 60, 62, and 64.
[0034]
A clutch plate 38 is provided between the leg plate 14 and the rotor 56 as a blocking means constituting a clutch releasing means. The clutch plate 38 has a disk shape, and a circular through hole 48 is formed at the center of the circle. The sleeve 22 is passed through the through hole 48, and the clutch plate 38 can rotate about the uniaxial line J. In the inner periphery of the through hole 48 of the clutch plate 38, a first holding recess 50 and a second holding as a recess outward in the radial direction with respect to the uniaxial line J corresponding to the first to third transmission rollers 32, 34 and 36. The recess 52 and the third holding recess 54 are cut out in a U-shape. The first to third transmission rollers 32, 34, and 36 are respectively inserted into the first to third holding recesses 50, 52, and 54, and the first to third transmission rollers 32, 34, and 36 are integrated. It is guided to move in the radial direction with respect to the axis J.
[0035]
As shown in FIG. 4, the first to third holding recesses 50, 52, 54 are gradually increased in the order of the first, second, and third holding recesses 50, 52, 54 in the direction of the uniaxial line J (recesses). The inner dimension is increased. The recess width L1 of the first holding recess 50 is sufficiently large and necessary for the radial movement of the first transmission roller 32 with respect to the uniaxial line J. The recess widths L2 and L3 of the second and third holding recesses 52 and 54 are sized so that the second and third transmission rollers 34 and 36 can move relative to the clutch plate 38 around the uniaxial line J, and The relative movement amount around the uniaxial line J of the third transmission roller 36 in the third holding recess 54 is made larger than the relative movement amount around the uniaxial line J of the second transmission roller 34 in the second holding recess 52. The first to third transmission rollers 32, 34, and 36 move together with the clutch plate 38 except that the first to third transmission rollers 32, 34, and 36 can move within the first to third holding recesses 50, 52, and 54.
[0036]
Engaging teeth 78 are provided on the outer periphery of the clutch plate 38. A lock plate 40 is provided on the outer surface of the leg plate 14 corresponding to the engaging teeth 78 as blocking means constituting clutch release means. The lock plate 40 has an engagement portion 74 that engages with the engagement teeth 78, and is rotatable about the axis of the support shaft 76 via a support shaft 76 in the same direction as the uniaxial line J direction. A position where 74 engages with the clutch plate 38 and a position where the clutch plate 38 is disengaged are obtained. A torsion coil spring 46 is locked between the lock plate 40 and a locking portion 44 protruding from the outer surface of the leg plate 14. The torsion coil spring 46 urges the lock plate 40 to engage with the clutch plate 38, and the clutch plate 38 can rotate in the webbing take-up direction, but prevents rotation in the webbing withdrawal direction. Is done. The clutch plate 38 is a one-way rotating body.
[0037]
An annular convex portion 80 projects from the outer surface of the leg plate 14 around the uniaxial line J. On the inner periphery of the annular convex portion 80, three arc-shaped concave portions 82 that are engaged with the first to third transmission rollers 32, 34, and 36 are provided. Protrusions 72 are provided in capes in the extending direction of the inner periphery of the circular hole 30 at the end of the first to third receiving recesses 60, 62, 64 on the webbing take-up direction side. The first to third transmission rollers 32, 34, and 36 are prevented from moving around the uniaxial line J by the recess 82, and are prevented from moving radially inward relative to the uniaxial line J by the protrusion 72.
[0038]
When the rotor 56 rotates relative to the first to third transmission rollers 32, 34, and 36 in the webbing take-up direction around one axis J, the first to third transmission rollers 32, 34, and 36 pass the protrusion 72. The first to third transmission rollers 32, 34, and 36 can be moved radially inward with respect to the uniaxial line J. The first to third transmission rollers 32, 34, and 36 are separated from the recess 82, and as shown in FIG. The second and third transmission rollers 34 and 36 are positioned on the webbing take-up direction side of the second and third holding recesses 52 and 54 before the clutch operation, and the positions are maintained even after the clutch operation. When the rotor 56 is rotated in the webbing take-up direction in the clutch operating state, the clutch plate 38 is moved together with the first to third transmission rollers 32, 34, 36 that move around the single axis J integrally with the rotor 56, the spool 20. It is rotated in the webbing take-up direction.
[0039]
After the clutch is operated, when the rotor 56 rotates in the webbing pull-out direction around the uniaxial line J, the clutch plate 38 cannot rotate in the webbing pull-out direction around the uniaxial line J. Therefore, the rotor 56 has the first to third transmission rollers 32 and 34. , 36 relative to the webbing pull-out direction around the uniaxial line J, and the first to third transmission rollers 32, 34, 36 can move radially outward relative to the uniaxial line J (in the direction away from the outer periphery of the sleeve 22). It can move (moves toward the rotor 56)), and the pinching is released, and the rotation between the rotor 56 and the sleeve 22 of the spool 20 is not transmitted (clutch release state shown in FIG. 4).
[0040]
Here, clutch release is performed at different timings for the first to third transmission rollers 32, 34, and 36 as follows. That is, when the rotor 56 is rotated in the webbing withdrawal direction around the uniaxial line J, as shown in FIG. 5, the movement in the webbing withdrawal direction around the uniaxial line J of the first transmission roller 32 is first prevented. Relative rotation in the webbing pull-out direction around one axis J with respect to the first transmission roller 32 can be performed, and the pinching of the first transmission roller 32 is released as shown in FIG. The second and third transmission rollers 34 and 36 follow the rotor 56 in the webbing pull-out direction around the uniaxial line J. The second transmission roller 34 is driven in the webbing pull-out direction around the uniaxial line J around the rotor 56 by a difference between the concave width L2 of the second holding recess 52 and the concave width L1 of the first holding recess 50, as shown in FIG. As shown in FIG. 3, when the second transmission roller 34 comes into contact with the end portion of the second holding recess 52 on the webbing withdrawal direction, movement in the webbing withdrawal direction around the one axis J of the second transmission roller 34 is prevented, and the rotor The second transmission roller 34 can be rotated relative to the second transmission roller 34 in the webbing pull-out direction around one axis J, and the second transmission roller 34 is released from being caught. The third transmission roller 36 follows the rotor 56 in the webbing pull-out direction around the uniaxial line J. After the movement in the webbing pull-out direction around the uniaxial line J of the second transmission roller 34 is blocked, the third transmission roller 36 is located between the notch width L3 of the third holding recess 54 and the notch width L2 of the second holding recess 52. As shown in FIG. 7, the third transmission roller 36 is driven by the difference in the webbing pull-out direction around the uniaxial line J to the rotor 56, and the end portion on the webbing pull-out direction side around the uniaxial line J of the third holding recess 54. , The movement of the third transmission roller 36 in the webbing pull-out direction around the one axis J is prevented, and the rotor 56 can rotate relative to the third transmission roller 36 in the webbing pull-out direction around the single axis J. The pinching of the transmission roller 36 is released. The pinching of the transmission roller is released sequentially. In this way, clutch release is sequentially performed at different timings.
[0041]
In the figure, reference numeral 84 denotes a bolt for mounting the rotor, which penetrates the rotor 56 on one axis J and is screwed to the sleeve 22 of the spool 20.
[0042]
Next, the operation of the webbing retractor 10 according to the first embodiment of the present invention will be described.
[0043]
Under normal conditions, the gas generator does not operate and the rotor 56 does not rotate. As shown in FIG. 4, the pinching between the rotor 56 of the first to third transmission rollers 32, 34, and 36 and the spool 20 is released, and the webbing 24 can be pulled out and taken up freely.
[0044]
In the event of a vehicle emergency such as when the vehicle is suddenly decelerated, the gas generator is activated and the rotor 56 is rotated in the webbing take-up direction. The rotor 56 is rotated relative to the first to third transmission rollers 32, 34, and 36 in the webbing take-up direction around one axis J. As shown in FIG. 5, the first to third transmission rollers 32, 34, and 36 are sandwiched between the rotor 56 and the sleeve 22 of the spool 20, and the rotation is transmitted between the rotor 56 and the sleeve 22 of the spool 20. Is done. The spool 20 is forcibly rotated in the webbing take-up direction. The webbing 24 is tensioned in the occupant restraint direction.
[0045]
When the webbing 24 is pulled in the webbing pull-out direction after the tension is no longer required, the rotor 56 rotates in the webbing pull-out direction around the uniaxial line J via the sleeve 22 and the first to third transmission rollers 32, 34, and 36. Is done. First, the movement in the webbing pull-out direction around the one axis J of the first transmission roller 32 is blocked, and the relative rotation of the rotor 56 in the webbing pull-out direction around the single axis J with respect to the first transmission roller 32 is realized. The pinching of the roller 32 is released. Next, the movement in the webbing pull-out direction around the uniaxial line J of the second transmission roller 34 is blocked (FIG. 6), and the relative rotation of the rotor 56 in the webbing pull-out direction around the uniaxial line J with respect to the second transmission roller 34 is realized. Then, the sandwiching of the second transmission roller 34 is released. Next, the movement in the webbing pull-out direction around the uniaxial line J of the third transmission roller 36 is prevented (FIG. 7), and the relative rotation of the rotor 56 in the webbing pull-out direction around the uniaxial line J with respect to the third transmission roller 36 is realized. Then, the pinching of the third transmission roller 36 is released. In this way, when the pinching of all the transmission rollers is released, the rotation between the rotor 56 and the sleeve 22 of the spool 20 is not transmitted. When releasing the clutch, the force required for the relative rotation of the rotor 56 with respect to the first to third transmission rollers 32, 34, and 36 is applied at different timings between the transmission units.
[0046]
Therefore, the clutch can be released with an appropriate force.
[0047]
The movement of the transmission roller in the webbing pull-out direction need not be sequentially prevented along the webbing take-up direction. It is only necessary that all the transfer rollers are not simultaneously prevented from moving in the webbing pull-out direction. For example, it is sufficient that the clutch can be released at different timings for at least two of the transmission rollers.
[0048]
Next, a webbing take-up device according to a second embodiment will be described with reference to FIGS. 8 to 13 and FIG.
[0049]
As shown in FIG. 8, in the clutch mechanism 178 of the webbing take-up device 150 of this embodiment, the clutch plates as the blocking means constituting the clutch releasing means are the first clutch plate 154, the second clutch plate 156, the third clutch. The plate 158 is divided into three pieces. The first to third clutch plates 154, 156, 158 have a fan shape, and are arranged at intervals M (see FIG. 10) along the circumferential direction around the uniaxial line J. The sleeve 22 of the spool 20 is penetrated in the inner periphery of the first to third clutch plates 154, 156, 158, and the engagement teeth 78 are formed on the outer periphery. The first to third clutch plates 154, 156, 158 can rotate about the uniaxial line J, and can relatively rotate about the uniaxial line J as long as the distance between the clutch plates M is limited.
[0050]
As shown in FIGS. 8, 10, and 17, a synthetic resin shear pin 200 projects from the outer surface of the leg piece 14 of the frame 12 toward the first to third clutch plates 154, 156, and 158. . There are a total of six share pins 200, one for each clutch plate, and fitted into pin holes 202 formed at both ends of the first to third clutch plates 154, 156, 158 around the uniaxial line J. Yes. In a state in which the shear pin 200 is fitted in the pin hole 202, the first to third clutch plates 154, 156, 158 are prevented from rotating around the uniaxial line J, their positions are maintained, and the gap is also maintained.
[0051]
A gear case 204 is provided on the outer periphery of the first to third clutch plates 154, 156, 158. The gear case 204 protrudes in an annular shape on the outer surface of the leg piece 14 of the frame 12 and faces the engagement teeth 78 of the first to third clutch plates 154, 156, 158. When the shear pin 200 is elastically deformed or broken and is detached from the pin hole 202 and the first to third clutch plates 154, 156, 158 rotate around the uniaxial line J, the first to third clutch plates 154, 156, 158 rotation around one axis J is guided along the inner periphery of the gear case 204.
[0052]
The engagement portion 74 of the lock plate 40 passes through the annular defect portion 206 of the gear case 204 and faces into the gear case 204 and is engaged with the engagement teeth 78 of the clutch plate. In FIG. 10, the engaging portion 74 of the lock plate 140 is engaged with the engaging teeth 78 of the first clutch plate 154, but the engaging portion 74 of the lock plate 140 includes the first to third clutch plates 154, The clutch teeth 156 and 158 can be engaged with the engaging teeth 78 of the clutch plate. Although the engaged clutch plate can rotate in the webbing take-up direction around the uniaxial line J, the engaged clutch plate is prevented from rotating in the webbing drawing direction around the uniaxial line J. As long as the distance between the plates is M, the webbing can be rotated around one axis J. 11 to 13, the shear pin 200, the pin hole 202, and the gear case 204 are omitted.
[0053]
A first transmission plate 160, a second transmission plate 162, and a third transmission plate serving as clutch members are disposed on the inner circumferential edges of the first to third clutch plates 154, 156, and 158 on the rotor 152 side in the uniaxial J direction at the circumferential center. The transmission plate 164 protrudes integrally with the first to third clutch plates 154, 156, 158. The first to third transmission plates 160, 162, and 164 have a radial direction with respect to the uniaxial line J as a plate thickness direction, and a tangential width around the uniaxial line J is reduced at the proximal end portion, and a radial direction with respect to the uniaxial line J It can be elastically deformed by bending like a cantilever.
[0054]
As shown in FIGS. 8 and 9, a first receiving recess 166, a second receiving recess 168, and a third receiving as clutch means provided on the rotor 152 corresponding to the first to third transmission plates 160, 162, and 164. The recess 170 is a tapered portion 172 whose portion on the webbing withdrawal direction side gradually becomes smaller in diameter toward the webbing withdrawal direction.
[0055]
Before the clutch is actuated, as shown in FIG. 10, the first to third clutch plates 154, 156, 158 are spaced M between the clutch plates, and the first to third transmission plates 160, 162, 164 are Thru | or the 3rd accommodation recessed part 166,168,170, and the webbing take-up direction side edge part. From this state, the rotor 152 rotates in the webbing winding direction around the uniaxial line J and moves relative to the first to third clutch plates 154, 156, 158 in the webbing winding direction around the uniaxial line J, that is, the rotor. When the 152 moves relative to the first to third transmission plates 160, 162, 164 of the first to third clutch plates 154, 156, 158 in the webbing take-up direction around the uniaxial line J, the first to third clutch plates The first to third transmission plates 160, 162, 164 of 154, 156, 158 are elastically deformed and moved radially inward with respect to the uniaxial line J, and the first to third accommodating portions 166, 168, The first to third transmission plates 16 of the first to third clutch plates 154, 156, 158 between the tapered portion 172 of the 170 and the sleeve 22 of the spool 20. , 162, 164 can rotate the transmission between the rotor 152 and the spool 20 is sandwiched (clutch operating state shown in FIG. 11). The distance M between the clutch plates is maintained even after the clutch is operated. When the rotor 86 is rotated in the webbing take-up direction around the uniaxial line J in the clutch operating state, the shear pin 200 is elastically deformed or broken by the rotational force of the rotor 86 and is detached from the pin hole 202, and the first to first The three clutch plates 154, 156, 158 are rotated together with the rotor 86 and the spool 20 while maintaining the distance M between the clutch plates.
[0056]
When the rotor 152 is rotated in the webbing pull-out direction in the clutch operating state, the first clutch plate 154 engaged with the lock plate 40 cannot be rotated in the webbing pull-out direction, and first, the rotor 152 is the first clutch plate 154. Is rotated relative to the first transmission plate 160 in the webbing pull-out direction around the uniaxial line J, the first transmission plate 160 of the first clutch plate 154 can be elastically returned and the nipping of the first transmission plate 160 is released. . Next, as shown in FIG. 12, when the second clutch plate 156 abuts against the first clutch plate 154 and movement in the webbing pull-out direction around the uniaxial line J is prevented, the rotor 152 moves the second clutch plate 156. The second transmission plate 162 is rotated relative to the second transmission plate 162 in the webbing pull-out direction around the uniaxial line J, the second transmission plate 162 of the second clutch plate 156 can move elastically, and the sandwiching of the second transmission plate 162 is released. Next, as shown in FIG. 13, when the third clutch plate 158 comes into contact with the second clutch plate 156 and is prevented from moving in the webbing pull-out direction around the uniaxial line J, the rotor 152 moves the third clutch plate 158 to the second position. The third transmission plate 164 is rotated relative to the third transmission plate 164 in the webbing pull-out direction around the uniaxial line J, and the third transmission plate 164 of the third clutch plate 158 can be elastically returned and the third transmission plate 164 is released. The pinching of the transmission plate is sequentially released, and the rotation between the rotor 152 and the sleeve 22 of the spool 20 is not transmitted (FIG. 10). The first to third transmission plates 160, 162, and 184 are released at different timings.
[0057]
Next, the operation of the second embodiment will be described.
[0058]
Under normal conditions, the gas generator does not operate and the rotor 152 does not rotate. As shown in FIG. 10, the pinching between the rotor 152 of the first to third transmission plates 160, 162, 164 and the sleeve 22 of the spool 20 is released, and the webbing 24 can be pulled out and taken up freely. .
[0059]
In the event of a vehicle emergency such as when the vehicle suddenly decelerates, the gas generator operates and the rotor 152 rotates in the webbing take-up direction. The rotor 152 is rotated relative to the first to third transmission plates 160, 162, and 164 in the webbing winding direction around the uniaxial line J. As shown in FIG. 11, the first to third transmission plates 160, 162, and 164 are caught, rotation can be transmitted between the rotor 152 and the sleeve 22, and the webbing 24 is tensioned to restrain the occupant.
[0060]
After the tension is no longer required, the webbing 24 is pulled in the webbing pull-out direction, and the rotor 152 is rotated in the webbing pull-out direction around the uniaxial line J. First, the first clutch plate 154 is prevented from moving in the webbing withdrawal direction around the uniaxial line J, and the relative rotation of the rotor 152 in the webbing withdrawal direction around the uniaxial line J with respect to the first transmission plate 160 of the first clutch plate 154 is prevented. As a result, the first clutch plate 154 is released from the first transmission plate 160. Next, movement of the second clutch plate 156 around the uniaxial line J in the webbing withdrawal direction is blocked (FIG. 12), and the webbing withdrawal around the uniaxial line J with respect to the second transmission plate 162 of the second clutch plate 156 of the rotor 56 is performed. Relative rotation in the direction is realized, and the second transmission plate 162 of the second clutch plate 156 is returned to the second position. Next, movement of the third clutch plate 158 around the uniaxial line J in the webbing withdrawal direction is blocked (FIG. 13), and the webbing withdrawal about the uniaxial line J with respect to the third transmission plate 164 of the third clutch plate 158 of the rotor 56 is performed. The relative rotation in the direction is realized, and the third transmission plate 164 of the third clutch plate 158 is released. In this manner, when the pinching of all the transmission plates is released, the rotation between the rotor 152 and the spool 20 is not transmitted. Also by this, the clutch release is performed at different timings for the first to third transmission plates 160, 162, and 164. When releasing the clutch, the force required for the relative rotation of the rotor 152 relative to the first to third transmission plates 160, 162, 164 provided on the first to third clutch plates 154, 156, 158 differs at different timings between the transmission plates. It takes. Therefore, the clutch can be released with an appropriate force.
[0061]
Other configurations and operational effects are the same as those in the first embodiment.
[0062]
The present invention is not limited to the above-described embodiments, and various forms are possible. For example, the clutch member of each of the above embodiments is configured with three transmission rollers in the first embodiment and three transmission plates in the second embodiment, but the number is three. The number is not limited to the above, and may be 2, 4, 5, 6, or the like.
[0063]
【The invention's effect】
In the webbing take-up device of the present invention, the clutch can be released with an appropriate force.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a webbing take-up device according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view of the clutch mechanism of the webbing take-up device according to the first embodiment viewed from the spool side.
FIG. 3 is a partial cross-sectional view showing the clutch mechanism of the webbing take-up device according to the first embodiment, cut along one axis.
FIG. 4 is a diagram of the clutch mechanism of the webbing take-up device according to the first embodiment viewed from the uniaxial rotor side.
FIG. 5 is a view corresponding to FIG. 4 and showing a state where a transmission roller is sandwiched between a rotor and a sleeve of a spool (clutch operating state).
FIG. 6 is a view corresponding to FIG. 4 and showing a releasing operation (clutch releasing operation) for pinching between the rotor of the transmission roller and the sleeve of the spool.
FIG. 7 is a diagram corresponding to FIG. 4 and showing the next course of FIG. 6 in the clutch release operation.
FIG. 8 is an exploded perspective view showing a webbing take-up device according to a second embodiment.
FIG. 9 is an exploded perspective view of the clutch mechanism of the webbing retractor according to the second embodiment as viewed from the spool side.
FIG. 10 is a view of a clutch mechanism of a webbing take-up device according to a second embodiment as viewed from the uniaxial rotor side.
11 corresponds to FIG. 10 and shows a state where the transmission plate is sandwiched between the rotor and the sleeve of the spool (clutch operating state).
FIG. 12 is a view corresponding to FIG. 10 and showing a pinching release operation (clutch release operation) between the rotor of the transmission plate and the sleeve of the spool.
13 corresponds to FIG. 10 and shows the next step of FIG. 12 in the clutch release operation.
FIG. 14 is an exploded perspective view showing a conventional webbing take-up device.
FIG. 15 is a diagram showing a non-rotation transmission state of a clutch mechanism of a conventional webbing take-up device, as viewed from the uniaxial rotor side.
FIG. 16 corresponds to FIG. 15 and shows a rotation transmission state of the clutch mechanism.
17 is a partial cross-sectional view taken along line 17-17 of FIG.
[Explanation of symbols]
10, 150 Webbing take-up device
20 spools
22 Sleeve (winding shaft)
32 First transmission roller (clutch member)
34 Second transmission roller (clutch member)
36 Third transmission roller (clutch member)
38 Clutch plate (one-way rotating body (blocking means (clutch release means)))
40 Lock plate (blocking means (clutch releasing means))
50 First holding recess (recess (blocking means (clutch releasing means)))
52 Second holding recess (recess (blocking means (clutch releasing means)))
54 Third holding recess (recess (blocking means (clutch releasing means)))
56, 152 Rotor (Rotating member)
60, 166 First receiving recess (clutch means)
62,168 Second receiving recess (clutch means)
64, 170 Third receiving recess (clutch means)
88, 138 Pretensioner
154 First clutch plate (blocking means (clutch release means))
156 Second clutch plate (blocking means (clutch release means))
158 Third clutch plate (blocking means (clutch release means))
160 First transmission plate (clutch member)
162 Second transmission plate (clutch member)
164 Third transmission plate (clutch member)

Claims (3)

A take-up shaft that rotates so that the webbing can be taken up and pulled out;
A rotating member that is rotated by the operation of the pretensioner in a vehicle emergency;
A plurality of clutch members provided between the winding shaft and the rotating member;
Clutch means for moving the clutch member to the take-up shaft side and transmitting rotational torque from the rotary member to the take-up shaft to rotate the take-up shaft in the webbing take-up direction;
Clutch releasing means for releasing the clutch by moving the clutch member to the rotating member side, and releasing the clutch at different timing for at least two of the clutch members;
A webbing take-up device comprising: The clutch means is configured to move the clutch member to the winding shaft side by relative rotation of the rotating member with respect to the clutch member in the webbing winding direction.
The clutch releasing means moves the clutch member to the rotating member side by relative rotation of the rotating member with respect to the clutch member in the webbing pull-out direction, releases the clutch, and rotates the clutch member along with the rotation of the rotating member in the webbing pull-out direction. The webbing take-up device according to claim 1, wherein at least two of the clutch members are disengaged at different timings by having blocking means for blocking at least two of the webbing withdrawal directions at different timings. The blocking means is a unidirectional rotating body that is prevented from rotating in the webbing pull-out direction and allowed to rotate in the webbing winding direction;
A plurality of recesses formed in the one-way rotating body corresponding to the respective clutch members and engaged with the clutch members, each having a recess inward dimension for restricting movement of the clutch member in the webbing pull-out direction; The inner dimensions differ between the recesses to prevent movement in at least two webbing pull-out directions in the clutch member at different timings; and
The webbing take-up device according to claim 2, comprising:

Images