JP4491266B2 - Webbing take-up device - Google Patents

Description

  The present invention relates to a webbing take-up device, and more particularly to a webbing take-up device capable of winding a webbing by rotating a take-up shaft by a motor.

  The occupant restraint seat belt device includes a webbing take-up device. In this webbing take-up device, a so-called tension reducer mechanism for reducing or eliminating the excessive feeling of pressure when the webbing is mounted, and a certain amount of webbing is taken up on the take-up shaft in a vehicle sudden deceleration state, etc. In addition to eliminating the slight slack called "etc." and increasing the restraining force of the occupant's body by webbing, a pretensioner mechanism that holds the occupant's body more reliably is provided. A so-called motor retractor having a configuration in which the motor is operated by a motor is known (see, for example, Patent Document 1 and Patent Document 2).

  In this type of motor retractor, for example, not only can the function of a tension reducer and pretensioner be exhibited as described above, but also it is possible to assist in winding and pulling out the webbing when wearing a normal webbing, Very useful.

  Further, particularly in recent years, in the motor retractor as described above, the distance to other vehicles and obstacles in front is detected by a forward monitoring device such as a distance sensor, and the distance to the vehicle and obstacles ahead is a constant value. If it is less than that, a configuration is considered in which the motor is operated and the winding shaft is rotated in the winding direction by the rotational force of the motor. In such a motor retractor, in order to prevent the rotation from the take-up shaft side from being transmitted to the motor, a clutch is interposed between the output shaft of the motor and the take-up shaft. Only the rotation is transmitted to the take-up shaft.

By the way, in such a conventional motor retractor, for example, an inertia disk and a spring for urging the inertia disk in a predetermined direction are provided, and the pawl is moved by using the inertia force acting on the inertia disk, and the clutch is moved. It is configured to connect and release. For this reason, it is necessary to ensure the size and weight of the inertia disk, and there is a problem that the clutch is enlarged as a whole.
JP 2001-130376 A JP 2001-347923 A

  In consideration of the above facts, the present invention has an object to obtain not only a rotation from the motor side by a clutch but also a simple and compact webbing take-up device.

A webbing take-up device according to a first aspect of the present invention includes a take-up shaft around which a webbing for restraining an occupant is wound so as to be taken out and drawn out, a motor, and mechanically between the motor and the take-up shaft. The rotation of the motor is transmitted to the take-up shaft to rotate the take-up shaft in the webbing take-up direction, and the transmission of the rotation generated on the take-up shaft side is interrupted to prevent the rotation A webbing take-up device comprising a clutch for preventing transmission to a motor, wherein the clutch is provided coaxially with a case and the take-up shaft, and the rotation of the motor is transmitted to rotate. A rotating body that is integrally connected to the winding shaft, a slider that is held by the case by a frictional force, and that can be moved relative to the rotating body within a predetermined range, and Provided in the rotating body, And is normally held in the disengaged position with the ratchet by the slider, and is separated from the slider when the rotating body rotates in the webbing take-up direction. The holding is released and the urging force engages the ratchet by the urging force to transmit the rotation of the rotating body in the webbing winding direction to the ratchet and to the webbing winding direction of the ratchet with respect to the rotating body. A lock bar that moves relative to the slider and is moved to the disengagement position by the slider and held when the rotating body rotates in the webbing pull-out direction. It is characterized by that.

The webbing take-up device described in claim 1 includes a clutch that transmits the rotation of the motor to the take-up shaft. The clutch includes a rotating body that is rotated by the rotation of the motor, a ratchet that is integrally connected to the winding shaft, and a rotating body that is provided on the rotating body and engages with the ratchet so that the rotating body moves in the webbing winding direction. And a lock bar for transmitting the rotation to the ratchet. The lock bar is always urged in the direction of engagement with the ratchet, and is normally held at the disengagement position with the ratchet by a slider. For this reason, the rotating body and the ratchet are normally rotatable relative to each other, and rotation generated on the winding shaft side is prevented from being transmitted to the motor.

  Thus, when the occupant seated in the vehicle seat pulls the webbing stored in the webbing take-up device, the webbing is drawn while the take-up shaft rotates in the webbing pull-out direction. Accordingly, the occupant can put the webbing on the body by hanging the pulled-out webbing around the body and, for example, engaging the tongue plate provided on the webbing with the buckle device.

  Furthermore, for example, when an obstacle is present in front of the vehicle while the vehicle is running and the distance between the vehicle and the obstacle (the distance from the vehicle to the obstacle) reaches a predetermined range, the motor rotates and the clutch rotates. The body is rotated in the webbing take-up direction. At this time, since the slider is held in the case by frictional force, the rotating body moves relative to the slider within a predetermined range, and the lock bar provided on the rotating body moves away from the slider. For this reason, the lock bar is engaged with the ratchet by the urging force, and the rotation of the rotating body in the webbing winding direction is transmitted to the ratchet via the lock bar. As a result, the ratchet is rotated in the webbing take-up direction, and the take-up shaft integrally connected to the ratchet is rotated in the webbing take-up direction. As a result, the webbing is taken up by the take-up shaft, so that the slight slack of the webbing in the mounted state, so-called “slack” is eliminated, and the restraining force of the occupant's body by the webbing can be increased.

  Moreover, in this state, the lock bar allows relative rotation in the webbing take-up direction with respect to the rotating body of the ratchet (winding shaft), so that the “slack” is eliminated as described above. When the situation becomes unavoidable, it is possible to forcibly rotate the winding shaft in the webbing winding direction by using another pretensioner device or the like. In this case, the restraining force of the occupant's body due to the webbing can be further increased, and the occupant's damage during a vehicle collision can be kept to a minimum.

  On the other hand, when the risk of vehicle collision as described above is avoided, the motor is reversely rotated and the rotating body of the clutch is rotated in the webbing pull-out direction. At this time, since the slider is held in the case by frictional force, the rotating body moves relative to the slider within a predetermined range, and the lock bar provided on the rotating body moves closer to the slider. For this reason, the lock bar is again moved to the disengagement position with the ratchet by the slider and held. Thereby, the rotating body and the ratchet can be rotated relative to each other again, and the winding shaft can be freely rotated.

  Here, in the clutch of the webbing take-up device, the slider and the lock bar are moved relative to each other by holding the slider in the case by the frictional force as described above, and the lock bar is engaged with the ratchet by this relative movement. Or it is the simple structure moved to a disengagement position. Therefore, compared with a conventional clutch that uses a large and heavy inertia disk to move the pawl, the overall configuration of the clutch can be greatly reduced, and thus the entire webbing take-up device can be reduced. The configuration can be made compact.

A webbing take-up device according to a second aspect of the present invention is the webbing take-up device according to the first or second aspect, wherein the rotating body is a gear wheel that rotates by transmission of rotation of the motor, and the lock. When the rotor that supports the bar is provided between the gear wheel and the rotor to connect the rotor and the rotation of the gear wheel is transmitted to the rotor and a load of a predetermined value or more is applied to the rotor. Has a spring claw that cuts off the transmission of rotation between the gear wheel and the rotor by the load and makes them relatively idle.

In the webbing take-up device according to the second aspect, when the gear wheel is rotated by the rotation of the motor, the rotation is transmitted to the rotor via the spring claw, and the rotor is rotated. For this reason, since the lock bar supported by the rotor moves relative to the slider within a predetermined range, the lock bar can be held and released by switching the rotation direction of the motor. it can.

  On the other hand, for example, when a load of a predetermined value or more is applied to the winding shaft from the webbing in a state where the winding shaft and the rotor are connected by the lock bar, the rotor has a predetermined value or more via the lock bar. The load of acts. When a load of a predetermined value or more is applied to the rotor, the spring claw disconnects the transmission of rotation between the gear wheel and the rotor by the load, so that both can idle relatively (a so-called “load limiter mechanism”). As a result, it is possible to prevent the winding shaft connected to the rotor via the lock bar from being rotated with an excessive force by the driving force of the motor.

  As described above, the webbing take-up device according to the present invention can not only transmit the rotation from the motor side to the take-up shaft by the clutch, but also can have a simple and compact configuration.

  FIG. 11 is a perspective view showing the overall configuration of the webbing take-up device 10 according to the embodiment of the present invention. FIG. 10 is a perspective view showing the configuration of the main part of the webbing take-up device 10. Further, FIG. 9 shows an overall configuration of the webbing take-up device 10 in an exploded perspective view.

  The webbing take-up device 10 includes a frame 12. The frame 12 includes a substantially plate-like back plate 14 and a pair of leg plates 16 and 18 that extend integrally from both ends of the back plate 14 in the width direction. The back plate 14 is a fastening member (not shown) such as a bolt. It is configured to be attached to the vehicle body by being fixed to the vehicle body by means.

  Between the pair of leg plates 16 and the leg plates 18 of the frame 12, a winding shaft 20 manufactured by die casting or the like is rotatably arranged. The winding shaft 20 has a drum shape as a whole, and a base end portion of a webbing (not shown) formed in a long belt shape is connected and fixed. When the winding shaft 20 is rotated to one side around the axis (hereinafter, this direction is referred to as a “winding direction”), the webbing is wound in layers on the outer peripheral portion of the winding shaft 20 from the base end side. When the webbing is pulled from the front end side, the webbing is pulled out while the winding shaft 20 is rotated (hereinafter, the rotation direction of the winding shaft 20 when the webbing is pulled out is referred to as “drawing direction”).

  One end side of the winding shaft 20 passes through the leg plate 18 and protrudes to the outside of the frame 12. A locking mechanism (not shown) is arranged on the side of the leg plate 18. The lock mechanism is configured to include an acceleration sensor, and is linked to a lock plate 22 spanned between the leg plate 16 and the leg plate 18 and a torsion bar 24 provided at the shaft core portion of the take-up shaft 20. ing. When the vehicle is suddenly decelerated or the like, one end of the torsion bar 24 is restrained via the lock plate 22 by the operation of the lock mechanism, and energy absorption is performed, while the take-up shaft 20 is prevented from rotating in the pull-out direction. It has become.

  On the other hand, the other end side of the winding shaft 20 penetrates the leg plate 16 and slightly protrudes outward of the frame 12. A connecting screw 21 formed in a hexagonal column shape is coaxially and integrally connected to the other end side of the winding shaft 20.

  Further, a clutch case 101 as a case constituting the clutch 100 according to the present embodiment is disposed outside the leg plate 16. The clutch case 101 is formed in a box shape from a metal material or the like (for example, an aluminum alloy), and opens toward the side opposite to the leg piece 16. A cover clutch 102 made of an iron plate or the like as a case is disposed on the opening side of the clutch case 101. The clutch case 101 and the cover clutch 102 are integrally fixed to the leg piece 16 by a screw 104.

  A circular through hole 106 is formed coaxially with the take-up shaft 20 in the central portion of the bottom wall of the clutch case 101, and the connecting screw 21 passes therethrough. Further, a portion around the through hole 106 slightly protrudes in a circular shape toward the side opposite to the leg piece 16, and a ring-shaped sliding surface 108 is formed. Further, a cylindrical bushing support portion 110 protruding toward the opposite side of the leg piece 16 is formed at the hole edge of the through hole 106. A bushing 112 (see FIGS. 1 and 2) formed in a ring shape from a resin material or the like is supported on the bushing support portion 110.

  A clutch gear portion 28 is disposed inside the clutch case 101. The clutch gear portion 28 includes a worm gear 34. The worm gear 34 has its own shaft disposed in a state orthogonal to the winding shaft 20, and its end is supported by the clutch case 101 via bushes 36 and 37, and its one end side extends from the clutch case 101. It protrudes outward. Further, a steel ball 38 is accommodated in the bearing portion of the clutch case 101 that supports the tip portion of the worm gear 34 and is in contact with the tip portion of the worm gear 34, and an adjustment screw 40 is screwed. The adjusting screw 40 presses the steel ball 38 at its tip, thereby pressing the steel ball 38 against the tip of the worm gear 34. Thereby, the axial displacement of the worm gear 34 is regulated (thrust adjustment). The steel ball 38 may be formed integrally with the tip of the adjustment screw 40 (configuration in which the tip of the adjustment screw 40 is formed in a spherical shape). On the upper side of the worm gear 34, a clutch main body 114 constituting the clutch 100 according to the present embodiment is provided.

  Here, in FIGS. 1 and 2, the configuration of the clutch body 114 is shown in an exploded perspective view.

  As shown in these drawings, the clutch body 114 includes a gear wheel 116. The gear wheel 116 is formed in a ring shape from a resin material or the like and is arranged coaxially with the winding shaft 20, and so-called worm wheel teeth 118 are formed on the outer peripheral portion thereof. The worm wheel teeth 118 mesh with the worm gear 34 described above. A plurality of (six in this embodiment) circumferential load receiving portions 120 are formed at regular intervals along the radial direction of the inner peripheral portion of the gear wheel 116. These circumferential load receiving portions 120 correspond to spring claws 182 of a ring 176 described later. Further, a plurality of (six in this embodiment) detents are provided on the end surface of the gear wheel 116 on one axial direction side (the arrow A direction side in FIGS. 1 and 2) at regular intervals along the circumferential direction. A recess 122 is formed. These rotation stopper recesses 122 correspond to rotation stopper claws 180 of a ring 176 described later.

  Inside the gear wheel 116, a rotor 124 formed in a disk shape from a metal material or the like (for example, zinc aluminum alloy or the like) is disposed coaxially with the gear wheel 116. The rotor 124 includes a bottomed cylindrical main body 126 and a flange portion 128 that protrudes in the radial direction on one axial direction side of the main body 126 (the arrow B direction side in FIGS. 1 and 2).

  A plurality of external teeth 130 are formed on the outer periphery of the main body 126 at regular intervals along the circumferential direction. Each external tooth 130 is formed such that a side wall (in the direction of arrow C in FIGS. 1 and 2) along the circumferential direction of the main body 126 is inclined with respect to the circumferential direction of the main body 126. The side wall on the other side (in the direction of arrow D in FIGS. 1 and 2) is formed in parallel along the radial direction of the main body 126 (in other words, the cross-sectional shape is trapezoidal). ing). Each external tooth 130 corresponds to a spring claw 182 of a ring 176 described later.

  A substantially cylindrical accommodating portion 132 is coaxially formed at the center of the bottom wall of the main body portion 126. On one side in the axial direction of the accommodating portion 132 (in the direction of arrow A in FIGS. 1 and 2), a ring-shaped support shaft portion 133 is coaxially projected. The support shaft portion 133 is rotatably supported in a circular hole 135 formed in the cover clutch 102 via a rotation support portion 175 of a holder 170 described later. Further, the bushing 112 described above is rotatably fitted to the other side in the axial direction of the housing part 132 (the arrow B direction side in FIGS. 1 and 2), and the other side in the axial direction of the housing part 132 is bushing. The clutch case 101 is rotatably supported via 112. Thereby, the main-body part 126 (rotor 126) can be rotated to its own axis line.

  A ratchet 134 formed in a substantially ring shape by an iron plate or the like is accommodated in the accommodating portion 132 of the main body portion 126. On the outer periphery of the ratchet 134, external teeth 136 that are so-called ratchet teeth are formed. Further, a through hole 138 having a hexagonal cross section is formed in the shaft core portion of the ratchet 134, and is integrally connected around the axis line in a state where the above-described connecting screw 21 passes therethrough. As a result, the ratchet 134 and the winding shaft 20 rotate together via the connecting screw 21.

  Note that one side of the ratchet 134 in the axial direction (the arrow B direction side in FIGS. 1 and 2) is slidably in contact with the bushing 112 described above. A washer 140 made of a resin material or the like is attached to the other axial end of the ratchet 134 (the arrow A direction side in FIGS. 1 and 2). The washer 140 is slidably in contact with the ring-shaped bottom wall of the housing portion 132, thereby restricting displacement of the ratchet 138 along the axial direction.

  On the other hand, a pair of guide holes 142 curved along the circumferential direction of the main body 126 are formed on the bottom wall of the main body 126 on the radially outer side of the housing portion 132. A slider 144 formed in a substantially block shape that is curved along the circumferential direction of the main body 126 by a resin material or the like is slidably attached to each guide hole 142. The pair of sliders 144 are held by the inner peripheral surface of the main body 126 and the outer peripheral surface of the accommodating portion 132, and move relative to the main body 126 (rotor 124) within a predetermined range along the guide hole 142. It is possible.

  A sliding piece 146 projects from one side of each slider 144 (in the direction of arrow A in FIGS. 1 and 2), and is in contact with the cover clutch 102 as shown in FIG. A retainer 148 is provided on the side of each slider 144 opposite to the sliding piece 146. The retainer 148 is a narrow metal piece having a spring property and is bent into a substantially square shape. In this retainer 148, a connecting portion 150 provided in the center portion in the longitudinal direction is fitted into a connecting hole 152 formed in the slider 144 so as to be integrally connected to the slider 144, and both end portions in the longitudinal direction are respectively connected to the clutch described above. It is pressed against the sliding surface 108 of the case 101 and is elastically deformed by a predetermined amount.

  For this reason, the sliding piece 146 of the slider 144 is pressed against the cover clutch 102 by the elastic force of the retainer 148, and movement of the slider 144 along the guide hole 142 (relative movement with respect to the rotor 124) has a predetermined friction. Power is given. Therefore, when the rotor 124 rotates, the slider 144 is temporarily held in the case (the clutch case 101 and the cover clutch 102) by the frictional force acting on the sliding piece 146 and the longitudinal ends of the retainer 148. In contrast, it moves relative to each other within a predetermined range along the guide hole 142.

  Further, a press holding piece 145 is formed at one end of each slider 144 in the bending direction (the end on the arrow C direction side in FIGS. 1 and 2). These press holding pieces 145 correspond to the pair of lock bars 154, respectively.

  Each lock bar 154 is formed in a substantially square shape by an iron plate or the like, and is disposed on one end side in the bending direction of each slider 144, and includes a ring-shaped bearing portion 156. Each bearing portion 156 is rotatably supported by a cylindrical support shaft 158 protruding from the bottom wall of the main body portion 126. A connecting piece 160 projects from the side of each bearing portion 156 opposite to the slider 144 (in the direction of arrow C in FIGS. 1 and 2). These connecting pieces 160 rotate together with the bearing portion 156 around the support shaft 158 so that the front end portion thereof penetrates the hole portion 162 formed in the accommodating portion 132 of the rotor 124 and the external teeth of the ratchet 134 described above. 136 is adapted to mesh with 136. Further, these connecting pieces 160 are always biased in the meshing direction with the external teeth 136 (ratchets 134) by the biasing force of the torsion coil spring 164. The torsion coil spring 164 is supported by a cylindrical support shaft 166 that protrudes from the bottom wall of the main body 126 of the rotor 124.

  A release piece 168 corresponding to the above-described press holding piece 145 is provided on the slider 144 side (the arrow D direction side in FIGS. 1 and 2) of each bearing portion 156. Each release piece 168 has an inclined surface whose end facing the slider 144 is inclined with respect to the moving direction of the slider 144 (the direction of arrows C and D in FIGS. 1 and 2).

  4A and 4B, the rotor 124 moves relative to the slider 144, so that the lock bar 154 moves toward and away from the slider 144 within a predetermined range. In the state where the lock bar 154 is close to the slider 144 (the state shown in FIG. 4A), the release piece 168 of the lock bar 154 is inside the press holding piece 145 of the slider 144 (the ratchet 134 side). By entering, it is held at the disengagement position against the urging force of the torsion coil spring 164. In this state, the connecting piece 160 of the lock bar 154 is separated from the ratchet 134.

  On the other hand, when the lock bar 154 is separated from the slider 144 (the state shown in FIG. 4B), the release piece 168 of the lock bar 154 is released from being held by the pressing holding piece 145 of the slider 144. . In this state, the connecting piece 160 of the lock bar 154 is moved to the ratchet 134 side (engagement position) by the urging force of the torsion coil spring 164, and its distal end portion is engaged with the external teeth 136.

  In the clutch main body 114 according to the present embodiment, the slider 144 is normally disposed close to the lock bar 154. Therefore, the lock bar 154 is normally configured to be held at the disengagement position (shown in FIG. 4A) by the release piece 168 being held by the pressing holding piece 145 of the slider 144.

  On the other hand, a holder 170 formed in a ring shape with a resin material or the like is disposed on the side opposite to the rotor 124 via the lock bar 154 (the arrow A direction side in FIGS. 1 and 2). The holder 170 includes a ring-shaped main body 172 and a pair of holding claws 174 provided on the outer periphery of the main body 172. The main body 172 regulates the axial displacement of the lock bar 154 with respect to the support shaft 158 (rotor 124), and the pair of holding claws 174 are arranged in the axial direction of the torsion coil spring 164 with respect to the support shaft 166 (rotor 124). Displacement is regulated.

  Further, the support shaft 133 of the rotor 124 passes through the circular hole 173 formed in the center of the main body 172. A rotation support portion 175 that slightly protrudes in a cylindrical shape toward the opposite side (the cover clutch 102 side) of the rotor 124 is provided at the hole edge of the circular hole 173, and the support shaft portion 133 of the rotor 124 is provided. Is rotatably supported by the circular hole 135 of the cover clutch 102 via the rotation support portion 175.

  On the other hand, on the outer side in the radial direction of the holder 170 and on one side in the axial direction of the rotor 124 (the arrow A direction side in FIGS. 1 and 2), a ring 176 made of a metal material having a spring property (for example, SUS) is disposed. Has been. The ring 176 includes a cover portion 178 formed in a ring shape. A plurality of (six in this embodiment) detent pawls 180 projecting outward in the radial direction are integrally formed on the outer peripheral portion of the cover portion 178. These detent pawls 180 are fitted in the detent recesses 122 of the gear wheel 116 described above. Accordingly, the ring 176 is integrally connected to the gear wheel 116 in the circumferential direction.

  Furthermore, a plurality of (six in the present embodiment) spring claws 182 having an elastic (spring property) shape in the outer peripheral portion of the cover portion 178 are provided along the circumferential direction of the cover portion 178. Are provided at regular intervals. Each spring claw 182 is integrally connected to the cover portion 178 at the base end, slightly bent at the middle in the longitudinal direction toward the inside in the radial direction of the cover portion 178, and has a distal end at the diameter of the cover portion 178. It is bent toward the outside in the direction, and is curved along the circumferential direction of the cover portion 178 as a whole.

  These spring claws 182 are arranged along the circumferential direction of the rotor 124 and the gear wheel 116 between the outer teeth 130 of the rotor 124 and the inner peripheral surface of the gear wheel 116 as shown in FIG. The inner portion is pressed against the external teeth 130 of the rotor 124 by its own elastic force. As a result, the ring 176 is integrally held by the rotor 124.

  Further, the outer portion of each spring pawl 182 is engaged with the inner peripheral surface of the gear wheel 116, and the gear wheel 116 is supported by the rotor 124 via each spring pawl 182. In this state, the gear wheel 116 is restricted from moving in the axial direction by the detent claw 180 of the ring 176 and the flange portion 128 of the rotor 124. Further, in this state, the cover portion 178 of the ring 176 prevents the slider 144, the lock bar 154, the torsion coil spring 164, and the holder 170 from falling off from the rotor 124. Is held in.

  Further, each tip portion of each spring claw 182 enters the valley portion of the external tooth 130 and enters one side wall of the external tooth 130 (the side wall formed in parallel along the radial direction of the main body portion 126). Each base end portion is in contact with the circumferential load receiving portion 120 of the gear wheel 116 described above. As a result, the gear wheel 116 and the rotor 124 are integrally connected to each other in the circumferential direction by the spring claws 182 (relative rotation is restricted), and when the gear wheel 116 rotates, The gear wheel 116 and the rotor 124 basically rotate integrally.

  In this case, the rotational force in the winding direction of the gear wheel 116 is transmitted to the proximal end portion of the spring claw 182 via the circumferential load receiving portion 120, and from the distal end portion of the spring claw 182 to the external teeth 130 of the rotor 124. The gear wheel 116 receives a load acting from the spring claw 182 along the circumferential direction via the circumferential load receiving portion 120 (the gear wheel 116 is a spring). The load receiving direction from the claw 182 is set along the rotation direction).

  In addition, in this case, as described above, since the spring claw 182 is a metal piece having a spring property, the rotational force generated by the relative rotation of the gear wheel 116 with respect to the rotor 124 resists the spring force (biasing force) of the spring claw 182. If the spring pawl 182 is large enough to allow the tip of each spring pawl 182 to come out of the valley of the external tooth 130, the connection between the gear wheel 116 and the rotor 124 by the spring pawl 182 is released. The gear wheel 116 and the rotor 124 can be rotated relative to each other (see FIG. 5B).

  Further, the rotational force in the pull-out direction of the gear wheel 116 is transmitted to the anti-rotation claw 180 of the ring 176 through the anti-rotation recess 122 and is transmitted from the tip of the spring claw 182 of the ring 176 to the external teeth 130 of the rotor 124. It has become so.

  On the other hand, a spacer 184 formed in a ring shape with a resin material or the like is disposed on the opposite side of the ring 176 from the rotor 124 (the arrow A direction side in FIGS. 1 and 2). The spacer 184 is sandwiched between the ring 176 and the cover clutch 102 and is not rotatable relative to the ring 176 around its axis. The spacer 184 prevents the metal ring 176 from sliding directly with the cover clutch 102 and facilitates relative rotation of the ring 176 (clutch main body 114) with respect to the cover clutch 102.

  The clutch 100 having the above configuration is configured such that the gear wheel 116 of the clutch main body 114 rotates as the worm gear 34 of the clutch gear 28 rotates, and the clutch main body 114 and the clutch gear 28 are A single case (clutch case 101 and cover clutch 102) is integrally assembled to form a unit as a whole.

  On the other hand, as shown in FIG. 9, a spring complete 42 is disposed on the side of the cover clutch 102. The spring complete 42 accommodates a spiral spring (not shown) inside. The spiral spring has an end on the outer side in the spiral direction locked to the case body, and an end on the inner side in the spiral direction locked to the tip of the connecting screw 21 penetrating the clutch main body 114. The shaft 20 is biased in the winding direction.

  On the other hand, a motor 44 and a motor gear portion 46 are disposed between the leg plate 16 and the leg plate 18 below the winding shaft 20.

  Here, in FIG. 8, the configurations of the motor 44 and the motor gear portion 46 are shown in an exploded perspective view.

  The motor 44 and the motor gear portion 46 include a housing 48. A motor 44 is attached to one side of the housing 48, and a motor gear portion 46 is provided on the other side of the housing 48. The motor 44 is fixed to one side of the housing 48 with the distal end side (output side) of the rotary shaft 50 facing the housing 48, and the distal end (output side) of the rotary shaft 50 is fixed to the other side of the housing 48 (motor gear portion). 46 side). A base plate 54 to which an electric harness 52 for driving the motor is connected is attached to the rear end side of the motor 44. An electric harness 52 is connected to the base plate 54, and a connecting portion of the electric harness 52 is connected to a power supply terminal 56 provided in a main body portion of the motor 44 by a crimp terminal structure. In addition, it is good also as a structure which connects the connection part of the electrical harness 52, and the electric power feeding terminal 56 by soldering etc. FIG.

  Further, the motor 44 is covered with a cover motor 58. The cover motor 58 is provided with a claw portion 60, and the cover motor 58 is fixed to the housing 48 by fitting and locking the claw portion 60 to a claw receiving projection 62 provided on the housing 48.

  Here, the cover motor 58 is provided with a first concave portion 64, and the base plate 54 is provided with a convex portion 66 that can be fitted into the first concave portion 64 corresponding to the first concave portion 64. Further, the motor 44 is provided with a second recess 68 into which the projection 66 can be fitted in correspondence with the projection 66 of the base plate 54.

  That is, the convex portion 66 is fitted into the second concave portion 68 to position the motor 44 with respect to the base plate 54, the convex portion 66 is fitted into the first concave portion 64, the base plate 54 is positioned to the cover motor 58, and the claw portion The assembly position of the motor 44 around the shaft with respect to the housing 48 is uniquely specified by fitting and locking 60 to the claw receiving projection 62 and fixing the cover motor 58 to the housing 48. .

  Further, the electric harness 52 for driving the motor is taken out from the rear end portion of the cover motor 58 toward the back plate 14 of the frame 12 opposite to the output side of the motor 44. Further, the take-out portion of the electric harness 52 of the cover motor 58 is waterproofed by a rubber cap 70.

  On the other hand, pinions 72 constituting a plurality of spur gears of the motor gear portion 46 are attached to the distal end of the rotating shaft 50 of the motor 44 projecting to the other side of the housing 48 (motor gear portion 46 side). Further, the motor gear portion 46 accommodates a gear 74 and a gear 76 that constitute driving force transmitting means, each of which is an external spur gear, in mesh with each other. Both the gear 74 and the gear 76 are arranged with their own axes parallel to the rotating shaft 50 of the motor 44, the gear 74 meshes with the pinion 72, and the gear 76 that is the final spur gear is The above-described clutch gear portion 28 is detachably connected to one end portion of the worm gear 34 protruding outward from the clutch case 101. Therefore, when the motor 44 is driven, the driving force is transmitted via the pinion 72, the gear 74, and the gear 76, and the worm gear 34 is rotated.

  The pinion 72, the gear 74, and the gear 76 are covered with a cover gear 78 attached to the housing 48. The cover gear 78 is provided with a claw portion 80, and the cover gear 78 is fixed to the housing 48 by fitting and locking the claw portion 80 to a claw receiving portion 82 provided on the housing 48.

  Thus, both the motor 44 and the motor gear portion 46 are integrally assembled in a single housing 48 and are configured as a unit as a whole.

  In the motor 44 and the motor gear portion 46 having the above-described configuration, the mounting stay 84 provided integrally with the housing 48 is attached to the clutch case 101 (that is, the frame 12) that houses the clutch main body portion 114 and the clutch gear portion 28 by screws 86. Removably attached. In a state where the housing 48 is attached to the clutch case 101 (frame 12), the motor 44 is in a state in which the rotary shaft 50 is orthogonal to the take-up shaft 20 and the output side thereof faces away from the back plate 14 of the frame 12. In addition, it is configured to be positioned between the pair of leg plates 16 and the leg plates 18 and directly below the take-up shaft 20.

  Further, here, the motor 44 and the motor gear portion 46 configured as described above are separably coupled to the worm gear 34 of the clutch 26 and the clutch gear portion 28 with a gear 76 as a final spur gear of the motor gear portion 46. Moreover, since the attachment stay 84 is detachably attached to the clutch case 101 by the screw 86, the motor 44 and the motor gear portion 46 remain in the assembled state by removing the screw 86 and removing the attachment stay 84 from the clutch case 101. Thus, it can be separated from the clutch case 101 (frame 12) independently.

  Furthermore, the motor 44 described above is configured to be operated based on a detection signal from a forward monitoring device, for example.

  Next, the operation of this embodiment will be described.

  In the webbing retractor 10 having the above-described configuration, the slider 144 of the clutch main body 114 is normally disposed close to the lock bar 154 as shown in FIG. Therefore, the release piece 168 of the lock bar 154 is normally held by the pressing holding piece 145 of the slider 144, and the connecting piece 160 of the lock bar 154 is separated from the external teeth 136 of the ratchet 134. For this reason, the ratchet 134 (winding shaft 20) is rotatable relative to the rotor 124.

  Therefore, when the occupant sits on the seat of the vehicle and pulls the webbing stored in the webbing take-up device 10, the webbing is drawn while the take-up shaft 20 rotates in the pull-out direction. As a result, the occupant can hang the webbing on the body and, for example, engage the tongue plate provided on the webbing with the buckle device to attach the webbing to the body.

  On the other hand, for example, when an obstacle is present in front of the vehicle while the vehicle is running and the distance between the vehicle and the obstacle (the distance from the vehicle to the obstacle) reaches a predetermined range, the driving of the motor 44 is started, The rotating shaft 50 is rapidly rotated.

  When the rotation shaft 50 of the motor 44 is rotated, the rotational force is applied to the gear wheel of the clutch main body 114 via the pinion 72, the gear 74, and the gear 76 of the motor gear portion 46 and the worm gear 34 of the clutch gear portion 28. 116, the gear wheel 116 is suddenly rotated in the winding direction. The rotation of the gear wheel 116 in the winding direction is transmitted to the proximal end portion of the spring claw 182 of the ring 176 via the circumferential load receiving portion 120 and from the distal end portion of the spring claw 182 to the external teeth 130 of the rotor 124. The rotor 124 is suddenly rotated in the winding direction.

  At this time, the slider 144 is held in the case (the clutch case 101 and the cover clutch 102) by the frictional force acting on the sliding piece 146 and the retainer 148, so that the rotor 124 is relatively relative to the slider 144 within a predetermined range. The lock bar 154 supported by the rotor 124 moves away from the slider 144.

  For this reason, the holding of the release piece 168 by the pressing holding piece 145 is released, the connecting piece 160 of the lock bar 154 moves to the ratchet 134 side by the biasing force of the torsion coil spring 164, and the leading end of the connecting piece 160 is the ratchet 134. (See the arrow E in FIG. 4B). Thereby, the rotation of the rotor 124 in the winding direction is transmitted to the ratchet 134 via the lock bar 154, and the ratchet 134 is rapidly rotated in the winding direction. Since the ratchet 134 is integrally connected to the take-up shaft 20, the take-up shaft 20 is rapidly rotated in the take-up direction together with the ratchet 134.

  As a result, the webbing is wound around the take-up shaft 20, so that the slight slack of the webbing, so-called “slack” is eliminated, and the restraining force of the webbing on the occupant body is improved. Even if the vehicle is suddenly decelerated, the webbing reliably holds the occupant's body.

  Further, in the state where “slack” is eliminated as described above, the occupant's body becomes an obstacle and basically the webbing cannot be wound around the winding shaft 20 any more. Therefore, a load of a predetermined value or more from the webbing acts on the winding shaft 20, and as a result, a load of a predetermined value or more acts on the rotor 124 via the ratchet 134 and the lock bar 154. When a load of a predetermined value or more is applied to the rotor 124, the spring pawl 182 is elastically deformed as shown in FIGS. The gear wheel 116 and the rotor 124 are allowed to slip relative to each other through the valley portion 130 (so-called “load limiter mechanism”, see arrow F in FIG. 5B).

  Accordingly, the winding shaft 20 connected to the rotor 124 via the ratchet 134 and the lock bar 154 can be prevented from being rotated in the winding direction by a driving force of the motor 44 with an excessive force, and webbing is necessary. It is possible to prevent the occupant's body from being tightened with the above force.

  In addition, in this state, the outer teeth 136 of the ratchet 134 are so-called ratchet teeth, so that the ratchet 134 (winding shaft 20) is in contact with the rotor 124 as shown in FIGS. 6 (A) and 6 (B). When a relative rotation is attempted in the winding direction (see arrow H in FIG. 6B), the lock bar 154 is flipped up by the external teeth 136 of the ratchet 134 (arrow G in FIG. 6B). The ratchet 134 (winding shaft 20) is allowed to rotate relative to the rotor 124 in the winding direction. As a result, when “slack” is eliminated as described above, for example, when a vehicle collision is unavoidable, the winding shaft 20 is forced in the winding direction by another pretensioner device or the like. It is also possible to rotate it. In this case, the restraining force of the occupant's body due to the webbing can be further increased, and the occupant's damage during a vehicle collision can be kept to a minimum.

  On the other hand, when the danger of a vehicle collision as described above is avoided, the rotating shaft 50 of the motor 44 is reversed. The rotational force of the rotary shaft 50 is transmitted to the gear wheel 116 of the clutch main body 114 via the pinion 72, the gear 74, and the gear 76 of the motor gear portion 46 and the worm gear 34 of the clutch gear portion 28. Is rapidly rotated in the pulling direction (see arrow D in FIG. 7A).

  The rotation of the gear wheel 116 in the pull-out direction is transmitted to the anti-rotation claw 180 of the ring 176 via the anti-rotation recess 122 of the gear wheel 116 and the external teeth of the rotor 124 from the tip of the spring claw 182 of the ring 176. 130, the rotor 124 is suddenly rotated in the drawing direction.

  At this time, the slider 144 is held in the case (the clutch case 101 and the cover clutch 102) by the frictional force acting on the sliding piece 146 and the retainer 148, so that the rotor 124 is relatively relative to the slider 144 within a predetermined range. The lock bar 154 supported by the rotor 124 moves closer to the slider 144.

  For this reason, when the pressing holding piece 145 of the slider 144 presses the inclined end surface of the releasing piece 168 of the lock bar 154, the releasing piece 168 is moved toward the ratchet 134 against the urging force of the torsion coil spring 164. (See arrow J in FIG. 7B), the connecting piece 160 of the lock bar 154 is separated from the external teeth 136 of the ratchet 134. When the lock bar 154 further approaches the slider 144, the release piece 168 of the lock bar 154 enters the inside (the ratchet 134 side) of the pressing holding piece 145 of the slider 144, and the lock bar 154 is held at the disengagement position. (The state shown in FIG. 7B). Thereby, the rotor 124 and the ratchet 134 can be relatively rotated again, and the winding shaft 20 can be freely rotated.

  Here, in the clutch 100 of the webbing take-up device 10, the slider 144 and the lock bar 154 are held by holding the slider 144 of the clutch body 114 in the case (clutch case 101 and cover clutch 102) by frictional force as described above. Are moved relative to each other, and the lock bar 154 is moved to the engagement position or the engagement release position with the ratchet 134 by this relative movement. Therefore, the overall configuration of the clutch 100 can be significantly reduced (particularly, reduced in thickness) compared to a configuration in which the pawl is moved using a large and heavy inertia disk as in the conventional clutch. The overall configuration of the webbing take-up device 10 can be made compact.

  Moreover, in the clutch 100 of the webbing take-up device 10, the clutch body 114 is not supported by the take-up shaft 20, but is supported by a case (the clutch case 101 and the cover clutch 102). That is, the clutch main body 114 is configured such that the support shaft 133 provided on one side in the axial direction of the housing portion 132 of the rotor 124 is rotatable in the circular hole 135 of the cover clutch 102 via the rotation support portion 175 of the holder 170. While being supported, the other side in the axial direction of the accommodating portion 132 is rotatably supported by the clutch case 101 via the bushing 112, so that it is rotatably supported by the case (the clutch case 101 and the cover clutch 102). . Therefore, in this webbing take-up device 10, the take-up shaft 20 is connected to the clutch main body 114 except in a state where the rotor 124 and the ratchet 134 (the take-up shaft 20) are connected by the lock bar 154 (during vehicle sudden deceleration, etc.) Can rotate independently. Thereby, smooth rotation of the winding shaft 20 is guaranteed, and the webbing take-up property during normal use is improved.

  Further, in the clutch 100 of the webbing take-up device 10, a circumferential load receiving portion 120 is provided on the gear wheel 116 of the clutch main body 114, and the rotational force in the take-up direction from the gear wheel 116 to the rotor 124 is provided. During transmission, the load acting on the gear wheel 116 from the spring claw 182 acts along the circumferential direction of the gear wheel 116 via the circumferential load receiving portion 120. For this reason, it is not necessary to increase the rigidity of the gear wheel 116 by assuming a load acting along the radial direction of the gear wheel 116 from the spring pawl 182 when the rotational force is transmitted.

  In addition, in this clutch 100, the spring pawl 182 is elastically deformed when a load of a predetermined value or more is applied to the rotor 124, thereby causing the tip portion to come out of the outer teeth of the rotor, and the gear wheel 116 and the rotor 124. It is the structure which isolate | separates transmission of the rotation between. That is, the operation of the “load limiter mechanism” as described above is performed between the rotor 124 and the spring pawl 182, and in this case as well, a load along the radial direction acts on the gear wheel 116. There is nothing. Therefore, also in this respect, it is not necessary to increase the rigidity of the gear wheel 116. Therefore, in this clutch 100, the gear wheel 116 can be molded thinly or made of resin or the like, and thereby the clutch 100 can be reduced in size and weight.

  Further, in the clutch 100 of the webbing retractor 10, the ring 176 of the clutch main body 114 has a cover for holding the gear wheel 116, slider 144, lock bar 154, torsion coil spring 164, and holder 170 in a predetermined assembly position. The portion 178 and the spring pawl 182 for the above-described “load limiter mechanism” are integrally provided. In addition, the ring 176 is configured to be integrally held by the rotor 124 by the elastic force of the spring pawl 182. That is, in the clutch main body 114, the gear wheel 116, the slider 144, the lock bar 154, the torsion coil spring 164, and the holder 170 are assembled at predetermined assembly positions, and the ring 176 is attached to the rotor 124 by the elastic force of the spring pawl 182. By holding it, each of the clutch constituent members can be temporarily held (sub-assembled) integrally. As a result, the assemblability when the clutch body 114 is assembled to the case (the clutch case 101 and the cover clutch 102) is greatly improved, and the productivity of the webbing take-up device 10 is improved.

  As described above, in the webbing take-up device 10 according to the present embodiment, not only the rotation from the motor 44 side can be transmitted to the take-up shaft 20 by the clutch 100, but also a simple and compact configuration. be able to.

  In the above embodiment, the clutch 100 transmits the rotation of the rotating shaft 50 of the motor 44 to the winding shaft 20 to rotate the winding shaft 20 in the webbing winding direction. The rotation of the rotating shaft 50 of the motor 44 may be transmitted to the winding shaft 20 by a clutch, and the winding shaft 20 may be rotated in the webbing pull-out direction.

It is a disassembled perspective view which shows the structure of the principal part of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention. It is a disassembled perspective view which shows the structure of the principal part of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention. It is sectional drawing which shows the partial structure of the clutch which is a structural member of the webbing winding apparatus which concerns on embodiment of this invention. The structure of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention is shown, (A) is a side view showing the state where a lock bar was held by a slider, and (B) is a lock bar. It is a side view which shows the state engaged with the ratchet. The structure of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention is shown, (A) is a side view showing the state where the gear wheel and the rotor were connected by the spring claw, (B) FIG. 5 is a side view showing a state in which the gear wheel and the rotor are idled relatively. The structure of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention is shown, (A) is a side view showing the state where a lock bar engaged with a ratchet, (B) is a lock bar. It is a side view which shows the state which permitted the relative rotation to the webbing winding direction with respect to the rotor of a ratchet. The structure of the clutch which is a structural member of the webbing winding device concerning an embodiment of the invention is shown, (A) is a side view showing the state where a lock bar engaged with a ratchet, (B) is a lock bar. It is a side view which shows the state hold | maintained at the slider. It is a disassembled perspective view which shows the structure of the peripheral member containing the motor which is a structural member of the webbing winding apparatus which concerns on embodiment of this invention. It is a disassembled perspective view which shows the whole structure of the webbing winding device concerning an embodiment of the invention. It is a perspective view which shows the structure of the principal part of the webbing winding device concerning an embodiment of the invention. 1 is a perspective view showing an overall configuration of a webbing take-up device according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Webbing winding device 20 Winding shaft 44 Motor 100 Clutch 101 Clutch case (case)
102 Cover clutch (case)
116 Gear wheel 124 Rotor 134 Ratchet 144 Slider 154 Lock bar 182 Spring claw

Claims (2)

A winding shaft on which a webbing for occupant restraint is wound so as to be retractable and a motor, and a motor are mechanically interposed between the motor and the winding shaft. A clutch for transmitting and rotating the take-up shaft in the webbing take-up direction, and blocking transmission of rotation generated on the take-up shaft side to prevent the rotation from being transmitted to the motor; In the webbing take-up device provided,
The clutch is
Case and
A rotating body provided coaxially with respect to the take-up shaft, and rotated by transmission of rotation of the motor;
A ratchet integrally connected to the winding shaft;
A slider that can be moved relative to the rotating body within a predetermined range by being held by the frictional force in the case;
Provided on the rotating body, always urged in the engagement direction with the ratchet and normally held in the disengagement position with the ratchet by the slider, and the rotating body rotated in the webbing take-up direction. In this case, the holding is released by moving away from the slider and engaged with the ratchet by the biasing force to transmit the rotation of the rotating body in the webbing winding direction to the ratchet and the rotating body of the ratchet Relative rotation in the webbing take-up direction is allowed, and when the rotating body rotates in the webbing pull-out direction, the slider moves closer to the slider and is moved to the disengagement position by the slider and held. A lock bar,
A webbing take-up device comprising: The rotating body is
A gear wheel that rotates by transmitting rotation of the motor;
A rotor for supporting the lock bar;
The gear wheel is provided between the gear wheel and the rotor to couple the gear wheel, and the rotation of the gear wheel is transmitted to the rotor. When a load of a predetermined value or more is applied to the rotor, the gear is caused by the load. A spring claw that disconnects the transmission of rotation between the wheel and the rotor and makes both relatively idle,
Having
The webbing take-up device according to claim 1.

Images