JP5485131B2 - Webbing take-up device - Google Patents

Description

  The present invention relates to a webbing take-up device in which a take-up shaft is rotated by driving a motor at a predetermined time.

  In the seat belt retractor of Patent Document 1 below, one end of the motor is fixed to the frame, and the motor is covered with a case unit.

  A motor stopper is disposed in the case unit on the other end side of the motor. The motor stopper is fixed to the unit stay integrally with the case unit, and the unit stay is fixed to the frame. Thereby, the other end side of the motor is supported by the frame via the motor stopper, the case unit, and the unit stay.

  Here, in this seat belt retractor, the other end of the motor is directly connected to the case unit via a motor stopper. For this reason, when a load due to an external force is applied to the case unit, the load may be input to the motor via the motor stopper.

JP 2010-69901 A

  In view of the above fact, the present invention provides a webbing take-up device capable of suppressing the load from being input to the motor via the covering member when a load due to an external force is applied to the covering member. Objective.

  The webbing take-up device according to claim 1 includes a take-up shaft on which a webbing for restraining a vehicle occupant is taken up, a frame on which the take-up shaft is rotatably supported, and one end side supported by the frame. A motor that is connected to the winding shaft and is driven at a predetermined time to rotate the winding shaft, and that covers the motor in a state separated from the motor, and that is provided with an abutment, and has an external force And a covering member with which the contact portion comes into contact with the frame when a load is applied.

  A 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 webbing take-up device is provided on the covering member below the contact portion, and discharges the liquid that has entered the covering member. 1 discharge part is provided.

  The webbing take-up device according to claim 3 is the webbing take-up device according to claim 2, wherein the first discharge portion is provided on the other end side of the motor on the covering member, and the motor is provided on the covering member. And a second discharge part for discharging the liquid that has entered the cover member.

  In the webbing take-up device according to the first aspect, the webbing is taken up on the take-up shaft that is rotatably supported by the frame. One end of the motor is supported on the frame, and the motor is covered with a covering member.

  The motor is connected to the winding shaft, and the winding shaft is rotated by driving the motor at a predetermined time.

  Here, the covering member is separated from the motor, and the abutting portion is provided on the covering member, and the abutting portion abuts on the frame when a load due to an external force is applied to the covering member.

  For this reason, when a load due to an external force is applied to the covering member, the movement of the covering member is restricted by the contact portion, so that the contact of the covering member with the motor is suppressed. Thereby, it can suppress that the load by external force is input into a motor via a coating | coated member.

  In the webbing take-up device according to the second aspect, the covering member is provided with a first discharge portion below the contact portion, and the first discharge portion discharges the liquid that has entered the covering member.

  For this reason, the covering member can have two functions: a function of suppressing a load due to an external force from being input to the motor and a function of discharging the liquid that has entered the covering member. Furthermore, since the contact portion is disposed above the first discharge portion, it is possible to prevent liquid from above from entering the covering member from the first discharge portion by the contact portion.

  In the webbing take-up device described in claim 3, the covering member is provided with a first discharge portion on the other end side of the motor. The covering member is provided with a second discharge portion on one end side of the motor, and the second discharge portion discharges the liquid that has entered the covering member.

  For this reason, even when one end side of the motor is disposed below the other end side and the webbing take-up device is attached to the vehicle body, the other end side of the motor is disposed below the one end side and the webbing take-up device is Even when attached to the vehicle body, the liquid that has entered the covering member can be discharged.

It is a disassembled perspective view which shows the structure of the webbing take-up device according to the embodiment of the present invention. It is the perspective view which decomposed | disassembled the case of the webbing winding apparatus which concerns on embodiment of this invention from the webbing winding apparatus. It is the side view which looked at the webbing winding device concerning an embodiment of the invention from the other side of the vehicles front and rear direction. FIG. 4 is a cross-sectional view (cross-sectional view taken along line 4-4 in FIG. 3) of the webbing take-up device according to the embodiment of the present invention viewed from the other side in the vehicle width direction. It is a perspective view of the motor of the webbing take-up device according to the embodiment of the present invention. (A) And (B) is a figure which shows the motor of the webbing winding device which concerns on embodiment of this invention. (A) is the side view seen from the vehicle width direction one side, (B) is the back view seen from the vehicle front-back direction other side.

  FIG. 1 is an exploded perspective view showing a configuration of a webbing take-up device 10 according to an embodiment of the present invention. In the drawings, one side in the vehicle longitudinal direction is indicated by an arrow LO, one side in the vehicle width direction (for example, the outside in the vehicle width direction) is indicated by an arrow WO, and the upper side is indicated by an arrow UP.

  As shown in FIG. 1, the webbing take-up device 10 includes a frame 12. The frame 12 includes a substantially plate-like back plate 14 and leg plates 16 and leg plates 18 that integrally extend from both ends in the width direction of the back plate 14. A plate-like stay 19 bent in a crank shape is fixed to the back plate 14, and the back plate 14 and the stay 19 are fixed to the vehicle body by a fastening means (not shown) such as a bolt, whereby a webbing take-up device 10 is attached to the vehicle body. The leg plate 16 and the leg plate 18 are respectively formed with circular arrangement holes 16A and arrangement holes 18A.

  Between the leg plate 16 and the leg plate 18, a spool 20 as a winding shaft manufactured by die casting or the like is rotatably arranged. The spool 20 has a drum shape as a whole, and a proximal end portion of a webbing 30 formed in a long band shape is connected and fixed to the spool 20. When the spool 20 is rotated around one of its axes (in the direction of arrow A shown in FIG. 1, this direction is hereinafter referred to as “winding direction”), the webbing 30 is rotated from its proximal end to the outer peripheral portion of the spool 20. When the webbing 30 is pulled from the tip end side, the spool 20 is rotated around the axis (in the direction of arrow B shown in FIG. 1). The webbing 30 is pulled out while rotating to a position called "".

  A torsion shaft (not shown) as an energy absorbing member constituting a force limiter mechanism is coaxially inserted in the spool 20, and an end portion of the torsion shaft on the leg plate 18 side extends from an end surface of the spool 20 on the leg plate 18 side. It is protruding. The end portion of the torsion shaft on the leg plate 16 side is connected to the end portion of the spool 20 on the leg plate 16 side so as not to be relatively rotatable, and the torsion shaft is rotatable integrally with the spool 20. A substantially cylindrical ratchet 24 is connected to the end of the torsion shaft on the leg plate 16 side on the leg plate 16 side of the spool 20 so as not to be relatively rotatable, and a screw 22 is fixed. It is sandwiched between the screw 22. The ratchet 24 is arranged coaxially with the spool 20, and ratchet teeth 24 </ b> A (external teeth) are formed on the outer periphery of the ratchet 24.

  A substantially cylindrical lock gear 26 as a rotating member is provided on the leg plate 18 side of the spool 20, and a torsion shaft passes through the lock gear 26 coaxially. Further, a torsion shaft is fixed to the lock gear 26 so as not to be relatively rotatable, and the lock gear 26 is rotatable integrally with the torsion shaft. Further, ratchet teeth 26 </ b> A (external teeth) are formed on the entire outer periphery of the lock gear 26.

  A box-shaped sensor cover 32 is attached to the outside of the leg plate 18 of the frame 12 (the arrow D side shown in FIG. 1), and the sensor cover 32 is opened toward the leg plate 18 side. An end portion of the torsion shaft on the leg plate 18 side is inserted inside the sensor cover 32 and is rotatably supported by a bearing portion (not shown) provided on the sensor cover 32. A known lock mechanism (not shown) is accommodated inside the sensor cover 32. When the lock mechanism is engaged with the ratchet teeth 26A of the lock gear 26 when the vehicle is suddenly decelerated, the rotation of the torsion shaft in the pull-out direction is restricted.

  Further, a pretensioner mechanism 34 is provided between the sensor cover 32 and the leg plate 18. The pretensioner mechanism 34 includes a cylinder 36 fixed to the leg plate 18, and a gas generator 38 is accommodated at the upper end portion of the cylinder 36. The gas generator 38 generates high-pressure gas in the cylinder 36 by operating an ignition device (not shown). A piston (not shown) is accommodated inside the cylinder 36. When gas is generated in the cylinder 36, the piston projects from the cylinder 36 and forcibly rotates the torsion shaft in the winding direction.

  As shown in FIG. 2, a substantially bottomed cylindrical case 54 made of resin is provided on the outer side of the leg plate 16 of the frame 12 (the arrow C side shown in FIG. 1). It opens toward the 16 side. The opening of the case 54 is closed by a cover 56. The case 54 is attached to the leg plate 16 via a gear housing 42 described later. The screw 22 of the spool 20 is inserted inside the case 54, and the screw 22 is rotatably supported by a bearing portion 57 provided in the case 54.

  A spiral spring (not shown) is accommodated in the case 54. In the mainspring spring, the outer end in the spiral direction is locked to the case 54 and the inner end in the spiral direction is locked to the screw 22 to urge the spool 20 in the winding direction.

  Further, the cover 56 is provided with a recess 58, and the recess 58 can accommodate a gear cover 114, which will be described later, protruding toward the case 54. For this reason, the enlargement of the webbing take-up device 10 is suppressed. A tension reducer mechanism (not shown) is accommodated between the cover 56 (including the recess 58) and the case 54. The tension reducer mechanism is formed by a mainspring spring when the webbing 30 is mounted on the occupant as will be described later. The urging force of the spool 20 in the winding direction can be reduced.

  As shown in FIG. 1, between the leg plate 16 of the frame 12 and the case 54, a gear housing 42 made of a resin that accommodates a speed reduction mechanism 40 described later is provided. The gear housing 42 is attached to the leg plate 16. It has been. A clutch housing portion (not shown) is provided on the side portion of the leg plate 16 at the upper portion of the gear housing 42, and the clutch housing portion is opened toward the leg plate 16 side.

  A through hole 44 having a circular cross section is formed through the bottom wall of the clutch housing portion. The through hole 44 is arranged coaxially with the spool 20, and the screw 22 is passed through the through hole 44. Further, a cylindrical support shaft portion 46 is provided on the bottom surface of the clutch housing portion. The support shaft portion 46 is disposed coaxially with the spool 20 and protrudes toward the leg plate 16 side.

  A gear housing portion 48 is provided in the lower portion of the gear housing 42 at the side portion of the case 54, and the gear housing portion 48 is opened toward the case 54 side. A communication hole 50 is formed through the gear housing 42 between the clutch housing portion and the gear housing portion 48, and the communication hole 50 communicates between the clutch housing portion and the gear housing portion 48.

  As shown in FIGS. 1 and 2, a lower cylindrical portion of the gear housing 42 is provided with a substantially cylindrical tube portion 52 at a portion on the leg plate 16 side, and the tube portion 52 protrudes toward the leg plate 16 side. Yes. A stepped portion 52A is provided at the distal end portion of the cylindrical portion 52 at the outer peripheral portion (see FIG. 4).

  On the other hand, as shown in FIG. 1, the clutch 60 constituting the speed reduction mechanism 40 is housed in the clutch housing portion of the gear housing 42 described above. The clutch 60 includes a substantially bottomed cylindrical clutch gear 62, and the clutch gear 62 is opened toward the leg plate 16 side. A support hole 62A having a circular cross section is formed through the bottom wall of the clutch gear 62. The support hole 62A is disposed coaxially with the spool 20 and is connected to the support shaft portion 46 of the clutch housing portion on the spool 20. It is supported so as to be relatively rotatable. External teeth 62B are formed on the outer peripheral portion of the clutch gear 62, and the external teeth 62B correspond to a reduction gear train 100 described later.

  A substantially bottomed cylindrical clutch cover 64 is provided between the clutch gear 62 and the leg plate 16 of the frame 12, and the clutch cover 64 closes the opening of the clutch gear 62.

  The ratchet 24 of the spool 20 is disposed inside the clutch gear 62, and a lock bar (not shown) is provided on the radially outer side of the ratchet 24. The lock bar is normally held at a position separated from the ratchet teeth 24A of the ratchet 24 by the biasing force of a return spring (not shown), but the clutch gear 62 is in the winding direction (the direction of arrow A shown in FIG. 1). When rotated, it meshes with the ratchet teeth 24A of the ratchet 24. In this meshing state, relative rotation of the clutch gear 62 in the winding direction with respect to the ratchet 24 is restricted, and the ratchet 24 is rotated in the winding direction together with the clutch gear 62. Thereby, the spool 20 is rotated in the winding direction. When the clutch gear 62 is rotated in the pull-out direction (the direction of arrow B shown in FIG. 1), the engagement between the lock bar and the ratchet teeth 24A of the ratchet 24 is released, and the spool 20 and the clutch gear 62 Is disconnected.

  Below the spool 20, a motor 66 is provided between the leg plate 16 and the leg plate 18 of the frame 12, and the motor 66 is arranged in parallel to the axial direction of the spool 20. A pair of screw portions 66B is provided at one end 66A (the end portion on the arrow C side shown in FIG. 1) of the motor 66, and the screw 67 is passed through the bottom wall of the cylindrical portion 52 of the gear housing 42 to be screwed. By fastening to the portion 66B, one end 66A of the motor 66 is fixed to the bottom wall of the cylindrical portion 52. Thereby, the motor 66 is supported by the frame 12 via the gear housing 42. The motor 66 is provided with an output shaft 66C. The output shaft 66C protrudes toward the gear housing 42 with respect to one end 66A of the motor 66 and passes through a through hole of the gear housing 42 (not shown). A gear 68 is fixed to the distal end portion of the output shaft 66 </ b> C, and the gear 68 is disposed in the gear accommodating portion 48 of the gear housing 42. On the other end 66D side (arrow D side shown in FIG. 1) of the motor 66, a cylindrical convex portion 66E is provided at the center, and the convex portion 66E is located on the frame 12 with respect to the motor 66. It protrudes to the leg plate 18 side (see FIG. 5).

  As shown in FIGS. 5 and 6A and 6B, a harness guide 70 made of resin is provided on the other end 66D side of the motor 66 (the arrow D side shown in FIG. 5). It has been. The harness guide 70 includes a substantially disc-shaped base portion 71, and a mounting hole 71 </ b> A having a circular cross section is provided at the center of the base portion 71. On the surface of one side of the base portion 71 (arrow C side shown in FIG. 5), a peripheral wall portion 73 is integrally provided on the lower side portion, and the peripheral wall portion 73 is disposed on the outer peripheral portion of the base portion 71. Thus, the base portion 71 is curved along the circumferential direction. The convex portion 66E of the motor 66 is inserted into the mounting hole 71A, and the inner peripheral portion of the peripheral wall portion 73 is in contact with the outer peripheral portion of the motor 66, whereby the harness guide 70 is attached to the motor 66. Yes.

  A guide claw 72 having a substantially C-shaped cross section is provided on the peripheral wall portion 73 of the harness guide 70. In addition, a pair of rectangular weld holes 74A and 74B having a rectangular cross section are formed through the base portion 71 of the harness guide 70, and a terminal 66B of the motor 66 is penetrated through the weld hole 74A, so that a weld hole 74B is formed. The terminal 66C of the motor 66 is passed through.

  On the other side (the arrow D side shown in FIG. 5) of the base portion 71 of the harness guide 70, a substantially rectangular parallelepiped guide portion 76A is provided on the guide claw 72 side of the welding hole 74A. A guide hole 78A having a rectangular cross section is formed through 76A along the longitudinal direction of the weld hole 74A. Further, on the other surface of the base portion 71, a substantially rectangular parallelepiped columnar outlet wall 80A is provided on the opposite side of the welding hole 74A from the guide portion 76A.

  Furthermore, a substantially rectangular parallelepiped guide portion 76B is provided on the other surface of the base portion 71 on the guide claw 72 side of the welding hole 74B, and the guide portion 76B has a guide hole 78B having a rectangular cross section. A through hole is formed along the longitudinal direction of the weld hole 74B. In addition, on the other side of the base portion 71, a substantially rectangular parallelepiped columnar outlet wall 80B is provided on the opposite side of the welding hole 74B from the guide portion 76B.

  A harness 82A and a harness 82B are inserted into the guide claw 72, and the harness 82A and the harness 82B are inserted through the guide hole 78A and the guide hole 78B, respectively. Thereby, the positions of the harness 82A and the harness 82B in the radial direction of the motor 66 are set. One end of the harness 82A and the harness 82B is in contact with the position exit wall 80A and the position exit wall 80B, respectively. Thereby, the position of the longitudinal direction of harness A82 and harness 82B is set. In this state, one end of the harness 82A and the harness 82B is welded to the terminal 66B and the terminal 66C of the motor 66, respectively. On the other hand, the harness 82A and the harness 82B are extended from an opening portion of a motor cover 90 described later and penetrated through the gear housing 42, and the other end side portion is connected to a control unit (not shown).

  As shown in FIGS. 1 to 4, a motor cover 90 as a substantially bottomed cylindrical covering member made of resin is provided on the leg plate 16 side of the frame 12 of the gear housing 42. It opens toward the gear housing 42 side.

  A mounting portion 92 is provided at the outer periphery of the motor cover 90 at the opening. The mounting portion 92 is fixed to the gear housing 42 in a state where the motor 66 and the harness guide 70 are accommodated inside the motor cover 90. ing. As a result, the motor cover 90 is separated from the motor 66 and the harness guide 70 (not connected to the motor 66 and the harness guide 70), and further, the outer peripheral portion of the motor 66 and the harness guide 70 and the peripheral wall of the motor cover 90. A gap is provided between the inner peripheral portion of each of them. Further, the opening of the motor cover 90 is fitted into the stepped portion 52 </ b> A of the cylindrical portion 52.

  On the outer surface of the bottom wall of the motor cover 90, a flange portion 94 is integrally provided as a contact portion having a substantially U-shaped cross section. The flange portion 94 includes a rectangular plate-shaped main body portion 94 </ b> A, and the main body portion 94 </ b> A protrudes toward the leg plate 18 side of the frame 12 with respect to the bottom wall of the motor cover 90. The main body portion 94A is disposed below the leg plate 18, and a gap is provided between the main body portion 94A and the leg plate 18. This gap is set smaller than the gap between the outer peripheral portions of the motor 66 and the harness guide 70 and the inner peripheral portion of the peripheral wall of the motor cover 90. A pair of substantially triangular plate-shaped ribs 94B and 94C are integrally provided at both ends in the width direction of the main body portion 94A, and the ribs 94B and 94C are directed downward from both ends in the width direction of the main body portion 94A. It is extended.

  A first discharge portion 96 having a substantially rectangular parallelepiped box shape is provided on the outer peripheral portion of the bottom wall of the motor cover 90. It protrudes to the side and is disposed below the flange portion 94. A first discharge hole 96 </ b> A having a rectangular cross section is formed through the lower portion of the first discharge portion 96, and the first discharge hole 96 </ b> A communicates with the inside of the motor cover 90. For this reason, the first discharge hole 96 </ b> A can discharge the liquid (for example, water) that has entered the motor cover 90.

  Further, the opening portion of the motor cover 90 is provided with a substantially rectangular second discharge portion 98 on the lower side portion, and the second discharge portion 98 is opened toward the gear housing 42 side. The dimension in the axial direction of the motor cover 90 of the second discharge part 98 is made larger than the dimension in the protruding direction of the protruding part 52A of the stepped part 52A of the gear housing 42. For this reason, the second discharge part 98 can discharge the liquid (for example, water) that has entered the motor cover 90 without being blocked by the step part 52A.

  On the other hand, as shown in FIG. 1, the gear 68 of the motor 66 described above is disposed in the gear accommodating portion 48 of the gear housing 42 described above, and the reduction gear train 100 constituting the reduction mechanism 40 is accommodated. .

  The reduction gear train 100 is provided with a spur gear 102 having a larger diameter than the gear 68 on the side of the gear 68 in the radial direction, and the gear 102 is engaged with the gear 68 of the motor 66. Thus, the gear housing 42 is rotatably supported.

  On one side in the axial direction of the gear 102 (arrow C side shown in FIG. 1), a spur gear 104 having a smaller diameter than the gear 102 is integrally provided, and the gear 104 is coaxial with the gear 102. Has been placed.

  The reduction gear train 100 is provided with a large-diameter gear 106 having a larger diameter than the gear 104 constituting the overload release mechanism, on the radial side of the gear 104. The large-diameter gear 106 is formed in a substantially bottomed cylindrical shape and is opened toward the case 54 side. Flat tooth external teeth 106 </ b> A (external teeth) are formed on the outer peripheral portion of the large diameter gear 106.

  A disc-shaped cover 112 is provided on the case 54 side of the large diameter gear 106, and the cover 112 closes the opening of the large diameter gear 106.

  The reduction gear train 100 is provided with a small-diameter gear 108 having a smaller diameter than the gear 106 on the other axial side of the large-diameter gear 106 (the arrow D side shown in FIG. 1). One end of the small-diameter gear 108 in the axial direction is coaxially inserted into the large-diameter gear 106, and the large-diameter gear 106 is supported so as to be rotatable relative to the small-diameter gear 108. The small-diameter gear 108 is rotatably supported by the gear housing 42 in a state where the external teeth 106A of the large-diameter gear 106 are engaged with the gear 104.

  A leaf spring (not shown) is fixed in the large-diameter gear 106, and the leaf spring is engaged with one end in the axial direction of the small-diameter gear 108. For this reason, normally, the large-diameter gear 106 and the small-diameter gear 108 are integrally rotatable. However, when a rotational force of a predetermined value or more is applied between the small diameter gear 108 and the large diameter gear 106, the leaf spring is elastically deformed to release the engagement between the leaf spring and the small diameter gear 108, and the large diameter Relative rotation of the small-diameter gear 108 with respect to the gear 106 is allowed (the overload release mechanism is activated).

  On the other hand, a flat-toothed external tooth 108 </ b> A (external tooth) is provided at the outer peripheral portion of the small-diameter gear 108 on the other axial end.

  The reduction gear train 100 is provided with a spur gear 110 having a larger diameter than the small diameter gear 108 on the side in the radial direction of the small diameter gear 108, and the gear 110 meshes with the external teeth 108 </ b> A of the small diameter gear 108. In this state, the gear housing 42 is rotatably supported.

  The gear 110 is meshed with the external teeth 62 </ b> B of the clutch gear 62 of the clutch 60 described above in the communication hole 50 of the gear housing 42. Thereby, the rotation of the output shaft 66 </ b> C of the motor 66 is transmitted to the clutch gear 62 via the reduction gear train 100.

  When the motor 66 rotates the output shaft 66C in the normal direction, the clutch gear 62 is rotated in the winding direction (the direction of arrow A shown in FIG. 1). Further, when the motor 66 reversely rotates the output shaft 66C, the clutch gear 62 is rotated in the pulling-out direction (the arrow B direction shown in FIG. 1).

  A substantially cylindrical gear cover 114 is provided on the case 54 side of the gear housing 42, and the gear cover 114 is opened to the gear housing 42 side. The gear cover 114 is fixed to the gear housing 42 so as to cover the reduction gear train 100.

  Next, the operation of the present embodiment will be described.

  In the webbing take-up device 10, when an occupant sits on the vehicle seat and pulls the webbing 30 stored in the webbing take-up device 10, the webbing 30 is pulled out while the spool 20 rotates in the pull-out direction. Thus, the occupant can hang the webbing 30 on the body and, for example, engage the tongue plate provided on the webbing 30 with the buckle device, thereby mounting the webbing 30 on the body.

  On the other hand, for example, when an obstacle exists 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 66 is started. The output shaft 66C of the motor 66 is suddenly rotated.

  When the output shaft 66C of the motor 66 is rotated, the rotational force is transmitted to the gear 68, the gear 102, the gear 104, the large diameter gear 106, the small diameter gear 108, the gear 110, and the clutch gear 62 of the clutch 60. 62 is rapidly rotated in the winding direction (the direction of arrow A shown in FIG. 1).

  When the clutch gear 62 is rotated in the winding direction, the lock bar of the clutch 60 is engaged with the ratchet teeth 24A of the spool 20, and the ratchet 24 is rotated integrally with the clutch gear 62 in the winding direction. Thereby, the spool 20 is rapidly rotated in the winding direction.

  As a result, the webbing 30 is wound around the spool 20, so that the slight slackness of the webbing 30, so-called “slack”, is eliminated, and the restraining force of the webbing 30 on the occupant's body is improved.

  Further, when the “slack” is eliminated, the occupant's body becomes an obstacle, and basically the webbing 30 cannot be wound around the spool 20 any more. For this reason, a load of a predetermined value or more is applied to the spool 20 from the webbing 30, and as a result, a load of a predetermined value or more is applied to the small diameter gear 108 via the clutch gear 62 and the gear 110.

  At this time, since the large-diameter gear 106 is about to rotate in the winding direction by the driving force of the motor 66, a relative rotational force acts between the small-diameter gear 108 and the large-diameter gear 106. When this rotational force exceeds a predetermined value, the engagement between the leaf spring fixed to the large-diameter gear 106 and one end in the axial direction of the small-diameter gear is released. Therefore, relative rotation between the large diameter gear 106 and the small diameter gear 108 is allowed.

  Thereby, it is possible to prevent the spool 20 from being rotated in the winding direction with an excessive force by the driving force of the motor 66, and it is possible to prevent the webbing 30 from tightening the occupant's body with an excessive force.

  On the other hand, when the danger of a vehicle collision is avoided, the output shaft 66C of the motor 66 is reversed. The rotational force of the output shaft 66C is transmitted to the gear 68, the gear 102, the gear 104, the large-diameter gear 106, the small-diameter gear 108, the gear 110, and the clutch gear 62 of the clutch 60, and the clutch gear 62 is suddenly pulled out ( It is rotated in the direction of arrow B shown in FIG.

  When the clutch gear 62 is rotated in the pull-out direction, the engagement between the lock bar of the clutch 60 and the ratchet teeth 24A of the spool 20 is released, and the connection between the spool 20 and the clutch gear 62 is released. As a result, the spool 20 can freely rotate.

  Here, one end face 66 </ b> A of the motor 66 is supported by the leg plate 16 of the frame 12 via the gear housing 42. The motor 66 and the harness guide 70 are covered with a motor cover 90. The motor 66 and the harness guide 70 are separated by the motor cover 90, and the outer periphery of the motor 66 and the harness guide 70 and the peripheral wall of the motor cover 90 are separated. A gap is provided between the inner peripheral portion. Further, the mounting portion 92 of the motor cover 90 is fixed to the gear housing 42, and a flange portion 94 is provided on the bottom wall of the motor cover 90. The clearance between the flange 94 and the leg plate 18 of the frame 12 is set smaller than the clearance between the outer peripheral portion of the motor 66 and the harness guide 70 and the inner peripheral portion of the peripheral wall of the motor cover 90. Yes.

  For this reason, for example, when an impact load due to dropping of the webbing take-up device 10 is applied to the motor cover 90 from below before the webbing take-up device 10 is attached to the vehicle body, the impact applied to the motor cover 90 is applied. The bottom wall side portion of the motor cover 90 is moved upward by the load. At this time, the flange portion 94 of the motor cover 90 is brought into contact with the leg plate 18 of the frame 12 to restrict the movement of the motor cover 90. For this reason, it is suppressed or prevented that the inner peripheral part of the surrounding wall of the motor cover 90 contacts the outer peripheral part of the motor 66 and the harness guide 70, and preferably, the outer peripheral part of the motor 66 and the harness guide 70 and the motor cover. A gap is still provided between the inner peripheral portion of the 90 peripheral walls. Thereby, it is possible to suppress or prevent an impact load from being input to the motor 66 via the motor cover 90. Therefore, for example, the deformation of the one end 66A of the motor 66 or the gear housing 42 due to the impact load is suppressed or prevented, and the gear 68 and the gear 102 of the motor 66 can be satisfactorily engaged.

  Further, a first discharge portion 96 is provided on the bottom wall of the motor cover 90 on the lower side of the flange portion 94, and a second discharge portion 98 is provided on the lower portion of the opening of the motor cover 90. Is provided. Therefore, if the liquid (water) enters the motor cover 90, the first discharge hole 96A and the second discharge unit 98 of the first discharge unit 96 discharge the liquid that has entered the motor cover 90. . As a result, the motor cover 90 can have two functions: a function of suppressing or preventing an impact load due to an external force from being input to the motor 66 and a function of discharging the liquid that has entered the motor cover 90. Further, since the flange portion 94 is disposed on the upper side of the first discharge portion 96, it is possible to suppress the liquid from above from entering the motor cover 90 from the first discharge portion by the flange portion 94.

  Moreover, the first discharge part 96 is provided on the other end side of the motor 66 of the motor cover 90, and the second discharge part 98 is provided on one end side of the motor 66 of the motor cover 90. Therefore, even when one end 66A of the motor 66 is disposed below the other end 66D and the webbing retractor 10 is attached to the vehicle body, the other end 66D of the motor 66 is disposed below the one end 66A. Even when the webbing take-up device 10 is attached to the vehicle body, the liquid that has entered the motor cover 90 can be discharged.

  The motor cover 90 is integrally provided with a flange 94. For this reason, by attaching the motor cover 94 to the gear housing 42, the flange portion 94 can be disposed below the leg plate 18 of the frame 12. Thereby, the assembly man-hour at the time of providing the collar part 94 in the webbing winding device 10 can be reduced.

  Further, the motor cover 90 is made of resin. For this reason, the motor cover 90 can be manufactured at low cost and can be reduced in weight.

  In the present embodiment, a gap is provided between the flange 94 of the motor cover 90 and the lower edge of the leg plate 18 of the frame 12. Instead of this, for example, the leg plate 18 is extended downward, and a substantially rectangular hole is formed through the leg plate 18. Further, the flange portion 94 may be inserted into the hole, and a gap may be provided between the inner peripheral surface of the edge portion of the hole and the flange portion 94. Thereby, even when a load due to an external force is applied to the motor cover 90 in the vertical direction and the vehicle width direction, the flange portion 94 of the motor cover 90 is brought into contact with the inner peripheral surface of the edge of the hole, and the motor cover 90 Movement is restricted. Therefore, the inner peripheral portion of the peripheral wall of the motor cover 90 is suppressed or prevented from coming into contact with the outer peripheral portions of the motor 66 and the harness guide 70. In other words, when a load due to an external force is applied to the motor cover 90 in the vertical direction and the vehicle width direction, the flange portion 94 of the motor cover 90 is brought into contact with the motor cover 90 so that the movement of the motor cover 90 is restricted. .

  In the present embodiment, when a load due to an external force is applied to the motor cover 90, the flange portion 94 of the motor cover 90 is brought into contact with the leg plate 18 of the frame 12. Instead, the flange portion 94 of the motor cover 90 may abut on the sensor cover 32 attached to the frame 12. That is, it is only necessary that the flange portions 94 of the motor cover 90 are brought into contact with the frame 12 constituting the support body or a member fixed to the frame 12.

10 Webbing take-up device 12 Frame 20 Spool (winding shaft)
30 Webbing 66 Motor 90 Motor cover (coating member)
94 collar (contact part)
96 1st discharge part 98 2nd discharge part

Claims (3)

A winding shaft on which a webbing for restraining a vehicle occupant is wound;
A frame on which the winding shaft is rotatably supported;
One end side is supported by the frame, is connected to the winding shaft, and is driven at a predetermined time to rotate the winding shaft,
A cover member that covers the motor in a state of being separated from the motor, a contact portion is provided, and the contact portion contacts the frame when a load is applied by an external force;
A webbing take-up device comprising:   2. The webbing take-up device according to claim 1, further comprising a first discharge portion that is provided on the covering member below the contact portion and discharges liquid that has entered the covering member. The first discharge part is provided on the other end side of the motor on the covering member;
3. The webbing take-up device according to claim 2, further comprising a second discharge portion that is provided on one end side of the motor on the covering member and discharges the liquid that has entered the covering member.

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