JP5485133B2 - Webbing take-up device - Google Patents

Description

  The present invention relates to a webbing take-up device in which a transmission mechanism transmits a rotational force to a spool.

  In the seatbelt retractor described in Patent Document 1 below, a power transmission mechanism is provided between the spindle assembly and the motor, and the power transmission mechanism has a plurality of gears. Accordingly, the power transmission mechanism transmits the power of the motor to the spindle assembly, whereby the spindle assembly is rotated and the seat belt is wound up.

  Further, the power transmission mechanism is accommodated in the housing space of the lower cover, and the movement of the plurality of gears in the axial direction of the power transmission mechanism is restricted by the upper cover by attaching the upper cover to the lower cover.

  However, in this seat belt retractor, it is unclear how the upper cover is attached to the lower cover.

  In such a seat belt retractor, the upper cover is attached to the lower cover with a predetermined number of elastic claws, and the movement of the gear in the axial direction may be limited by the elastic force of the predetermined number of elastic claws. .

  In this case, if one elastic claw can apply an elastic force to the upper cover in a wide range in the circumferential direction of the accommodating space, the number of elastic claws can be reduced and the upper cover can be easily attached to the lower cover. .

JP 2010-30502 A

  In view of the above fact, an object of the present invention is to obtain a webbing take-up device in which the engaging portion can apply an elastic force to the restricting member over a wide range in the circumferential direction of the opening.

  The webbing take-up device according to claim 1 is provided with a spool on which a webbing to be worn by an occupant of the vehicle is taken up, a transmission mechanism that transmits a rotational force to the spool, and an opening, and accommodates the transmission mechanism. An accommodating member, a restricting member that is assembled to the accommodating member to restrict movement of the transmission mechanism toward the opening, and an engaged portion provided on one of the accommodating member or the restricting member; And the other of the housing member or the restricting member is provided so as to be elastically deformable, and the total amount of stretching in the circumferential direction of the opening at the stretched portion in the circumferential direction of the opening is the circumference of the opening. The restriction member is made larger than the total amount of stretching of the elastic deformation portion in the portion extending in the direction perpendicular to the direction perpendicular to the circumference of the opening and engaged with the engaged portion, so that the restricting member is attached to the housing member. Assembled And it includes an engaging portion.

  The webbing take-up device according to claim 2 is the webbing take-up device according to claim 1, further comprising a motor that generates a rotational force, and the transmission mechanism is a support in which the opening direction of the opening is set in the axial direction. A shaft, and a gear that is supported by the support shaft and transmits a rotational force generated by the motor to the spool.

  The webbing take-up device according to claim 3 is the webbing take-up device according to claim 1 or 2, wherein the engaging portion has the opening circumferentially perpendicular side or the opening at both ends in the longitudinal direction. While extending to the opening direction side, it extends to the opening circumferential direction side at the middle portion in the longitudinal direction.

  In the webbing take-up device according to the first aspect, the transmission mechanism transmits the rotational force to the spool on which the webbing is taken up.

  The housing member is provided with an opening, and the housing member houses the transmission mechanism. Furthermore, the restriction member restricts the movement of the transmission mechanism toward the opening portion side by assembling the restriction member to the housing member.

  By the way, an engaged portion is provided on one of the accommodating member or the restricting member, and an engaging portion is provided on the other of the accommodating member or the restricting member so as to be elastically deformable, and the engaged portion is engaged with the engaged portion. By combining, the limiting member is assembled to the housing member.

  Here, the total amount of stretching in the circumferential direction of the opening of the engagement portion in the circumferential portion of the engagement portion extending in the circumferential direction of the opening is the elastic deformation in the portion of the engagement portion extending in the direction perpendicular to the circumferential direction of the opening. It is made larger than the total amount of stretching in the direction perpendicular to the periphery of the opening of the part. For this reason, the engaging portion can apply an elastic force to the restricting member in a wide range in the circumferential direction of the opening.

  In the webbing take-up device according to the second aspect, in the transmission mechanism, the gear is supported by the support shaft, and the gear transmits the rotational force generated by the motor to the spool.

  Here, the support shaft has the opening direction of the opening as the axial direction. For this reason, the restriction member can restrict movement of the gear in the axial direction.

  In the webbing take-up device according to claim 3, both end portions in the longitudinal direction of the engagement portion extend toward the opening portion perpendicular direction or the opening direction side of the opening portion, and the intermediate portion in the longitudinal direction of the engagement portion is arranged around the opening portion. Stretch in the direction side. For this reason, the extending | stretching amount to the opening part circumferential direction side in the longitudinal direction intermediate part of an engaging part can be enlarged, and a to-be-engaged part can be easily engaged with the longitudinal direction intermediate part of an engaging part.

It is a side view which shows the principal part of the webbing winding device concerning an embodiment of the invention. It is the disassembled perspective view seen from diagonally lower side which shows the principal part of the webbing winding device concerning an embodiment of the invention. It is the bottom view seen from the lower side which shows the principal part of the webbing winding device concerning an embodiment of the invention. It is sectional drawing (4-4 sectional view taken on the line of FIG. 3) which shows the principal part of the webbing winding device concerning an embodiment of the invention. It is sectional drawing (5-5 sectional view taken on the line of FIG. 1) which shows the principal part of the webbing winding device concerning an embodiment of the invention. 1 is an exploded perspective view showing a webbing take-up device according to an embodiment of the present invention.

<Configuration of the present embodiment>
FIG. 6 is an exploded perspective view showing the overall configuration of the webbing take-up device 10 according to the embodiment of the present invention.

  As shown in this figure, the webbing take-up device 10 includes a frame 12 that is fixed to a vehicle body constituting member such as a skeleton member or a reinforcing member of a vehicle. The frame 12 has a U-shaped cross section, and includes leg plates 14 and 16 that face each other along the vehicle longitudinal direction when attached to the vehicle body.

  A spool 18 is provided between the leg plates 14 and 16. The spool 18 is formed in a substantially cylindrical shape whose axial direction is along the opposing direction of the leg plate 14 and the leg plate 16. A longitudinal base end portion of the webbing 20 formed in a long band shape is locked to the spool 18. The spool 18 rotates in the winding direction (the direction of arrow A in FIG. 6) which is one of the circumferences of the central axis, thereby winding and storing the webbing 20 from the longitudinal base end side. Further, for example, when the occupant pulls the webbing 20 when mounting the webbing 20 on the body, the webbing 20 wound on the spool 18 is pulled out, and the drawing direction opposite to the winding direction (arrow B in FIG. 6). The direction of the spool 18 is rotated.

  A torsion shaft (not shown) is provided inside the spool 18. The torsion shaft is a rod-shaped member whose axial direction is along the axial direction of the spool 18. The torsion shaft is connected to the spool 18 in a state in which the end portion on the leg plate 16 side cannot rotate relative to the spool 18 coaxially.

  Further, a housing 24 of a locking mechanism 22 as a locking means is attached to the side of the leg plate 14 opposite to the leg plate 16, and the end of the torsion shaft on the leg plate 14 side is around the central axis of the spool 18. The housing 24 is directly or indirectly supported so as to be rotatable. A so-called “VSIR mechanism” that operates when the vehicle is suddenly decelerated and restricts rotation of the end of the torsion shaft on the leg plate 14 side in the pull-out direction is configured inside the housing 24. It constitutes a so-called “WSIR mechanism” that operates by rotating the torsion shaft suddenly in the pulling direction and regulating the rotation of the end of the torsion shaft on the leg plate 14 side in the pulling direction. Various parts are stored.

  Further, a pretensioner 26 as a force pulling means is provided on the opposite side of the leg plate 14 from the leg plate 16. The pretensioner 26 operates in a vehicle suddenly decelerating state. By operating, the pretensioner 26 applies a rotational force in the winding direction to the end of the torsion shaft on the leg plate 14 side or the spool 18, thereby Force to rotate in the winding direction.

  On the other hand, a motor 28 as a driving means is provided below the spool 18 between the leg plate 14 and the leg plate 16. In the motor 28, the axial direction of the output shaft 28 </ b> A as a support shaft is parallel to the axial direction of the spool 18, and the output shaft 28 </ b> A side of the motor 28 is formed by a through hole 16 </ b> A formed in the lower portion of the leg plate 16. The leg plate 16 is exposed on the side opposite to the leg plate 14.

  The motor 28 includes a battery mounted on the vehicle via an ECU (not shown) as a control unit, and a front monitoring device such as a radar device that measures the distance to other traveling vehicles and obstacles in front of the vehicle. Electrically connected. When the ECU determines that the distance to other traveling vehicles and obstacles in front of the vehicle is less than a certain value based on the electrical signal output from the forward monitoring device, and a vehicle collision is predicted The ECU energizes the motor 28 to operate the motor 28.

  A gear housing 30 as a housing member is attached to the side of the leg plate 16 opposite to the leg plate 14.

  A lower recess 32 is formed in the lower portion of the gear housing 30 as an accommodating portion, and the lower recess 32 is opened toward the side opposite to the leg plate 16 to form a lower opening 32A as an opening. Has been. A cylindrical first concave portion 34 is provided in the lower portion of the lower concave portion 32, and a cylindrical second concave portion 36 and a third concave portion 38 are provided in the upper portion of the lower concave portion 32. The axial directions of the first concave portion 34, the second concave portion 36, and the third concave portion 38 are arranged in parallel with the output shaft 28A of the motor 28, respectively, and the first concave portion 34, the second concave portion 36, and the third concave portion 38 are They are polymerized and arranged in the radial direction. The diameter of the first recess 34 is larger than that of the second recess 36 and the third recess 38, and the diameter of the second recess 36 is smaller than that of the third recess 38.

  A cylindrical upper concave portion (not shown) as an additional accommodating portion is formed in the upper portion of the gear housing 30, and the upper concave portion is opened toward the leg plate 16 side to be an upper opening as an additional opening portion. (Not shown) is formed. The upper concave portion is arranged coaxially with the spool 18, and the upper concave portion has a diameter larger than that of the first concave portion 34 of the lower concave portion 32 and communicates with the third concave portion 38 of the lower concave portion 32. .

  An output shaft 28 </ b> A of the motor 28 passes through the bottom wall of the first recess 34 of the lower recess 32, and the main body portion of the motor 28 is fixed to the bottom wall of the lower recess 32.

  The gear housing 30 accommodates a driving force transmission mechanism 40 as a transmission mechanism. A flat toothed output gear 42 is coaxially and integrally attached to the output shaft 28 </ b> A of the motor 28 with external teeth as a gear in the first recess 34 of the gear housing 30.

  In the second recess 36 of the lower recess 32, a two-stage shaft 44 as a support shaft is provided coaxially and integrally on the bottom wall, and the two-stage shaft 44 has a two-stage gear 46 as a gear. Are supported coaxially and rotatably. The two-stage gear 46 is provided with a large-diameter gear 48 that is a flat tooth with external teeth coaxially. The large-diameter gear 48 meshes with the output gear 42 and has a larger diameter than the output gear 42. Yes. The two-stage gear 46 is coaxially provided with a small-diameter gear 50 having external teeth and flat teeth on the lower opening 32A side of the large-diameter gear 48. The small-diameter gear 50 has a smaller diameter than the large-diameter gear 48. And is integrated with the large-diameter gear 48.

  An overload release mechanism 52 as a gear (load limiting mechanism) is provided in the first recess 34 of the lower recess 32, and a support shaft 54 as a support shaft is provided on the bottom wall in the first recess 34. Are provided coaxially and integrally. A hollow and externally toothed flat tooth ring holder 56 as an input gear is supported on the support shaft 54 so as to be coaxially and freely rotatable via a rotor 58 described below. The small-diameter gear 50 meshes with the small-diameter gear 50 and has a larger diameter than the small-diameter gear 50. In the ring holder 56, a spur rotor 58 having external teeth as a transmission gear is provided. The rotor 58 has a smaller diameter than the ring holder 56 and is coaxially rotatable with the support shaft 54. It is supported. The rotor 58 protrudes from the ring holder 56 to the side opposite to the lower opening 32 </ b> A, and the ring holder 56 is coaxially and rotatably supported on the outer periphery of the rotor 58. A predetermined number (for example, two) of rings 59 (see FIG. 4) as elastic members are provided in the ring holder 56, and the ring 59 has elasticity. The ring 59 is stretched between the ring holder 56 and the rotor 58. Normally, the ring holder 56 and the rotor 58 are integrally rotatable by a predetermined number of rings 59.

  In the third recess 38 of the lower recess 32, a spur intermediate gear 60 is supported coaxially and freely by external teeth as a gear. The intermediate gear 60 is supported by the rotor 58 of the overload release mechanism 52. It is meshed and has a larger diameter than the rotor 58.

  A clutch mechanism 62 as a gear (a coupling mechanism) is provided in the upper recess of the gear housing 30.

  In the upper recess, a hollow and externally toothed clutch gear 64 is coaxially and rotatably supported. The clutch gear 64 meshes with the intermediate gear 60 and has a larger diameter than the intermediate gear 60. Has been. Therefore, when the motor 28 is operated and the output shaft 28A rotates, the rotation (rotational force, driving force) of the output shaft 28A causes the output gear 42, the two-stage gear 46 (the large diameter gear 48 and the small diameter gear 50), overload. The clutch gear 64 is rotated in the winding direction by being decelerated and transmitted to the clutch gear 64 via the opening mechanism 52 (ring holder 56, rotor 58 and a predetermined number of rings 59) and the intermediate gear 60.

  In the clutch gear 64, a lock bar (not shown) as a clutch member is rotatably supported in a state where a predetermined number (for example, two) is urged. A ratchet gear 66 as an integral gear is disposed in the clutch gear 64, and the ratchet gear 66 cannot be coaxially rotated relative to the spool 18 via the end of the torsion shaft on the leg plate 16 side. Linked in state. External ratchet teeth 66A are formed on the entire outer periphery of the ratchet gear 66. When the clutch gear 64 is rotated in the winding direction as described above, a predetermined number of lock bars are attached by the clutch gear 64. By rotating against the force and meshing with the ratchet teeth 66A of the ratchet gear 66, the ratchet gear 66 is rotated integrally with the clutch gear 64, and the spool 18 is rotated in the winding direction.

  The ratchet gear 66 is exposed on the side opposite to the leg plate 16 of the clutch gear 64 and is exposed on the side opposite to the leg plate 16 of the gear housing 30 (the bottom wall of the upper recess). A box-shaped spring cover 68 is attached to the upper portion of the gear housing 30 on the side opposite to the leg plate 16, and a mainspring spring (not shown) as an urging means is accommodated in the spring cover 68. ing. The mainspring spring is connected to a ratchet gear 66, and the mainspring spring urges the spool 18 in the winding direction via the ratchet gear 66 and the end of the torsion shaft on the leg plate 16 side.

  A substantially disc-shaped clutch cover 70 is attached to the upper portion of the gear housing 30 on the leg plate 16 side, and the clutch cover 70 is located above the upper recess of the gear housing 30 with the ratchet gear 66 passing therethrough. The opening is closed.

  As shown in detail in FIG. 1 to FIG. 5, the gear housing 30 includes a substantially cross-sectional table as an engaged portion on the outer peripheral wall of the first recess 34, the second recess 36 and the third recess 38 of the lower recess 32. A first protrusion 72, a second protrusion 74, and a third protrusion 76 having a shape are formed, and the first protrusion 72 is disposed on the opposite side of the first recess 34 from the second recess 36 and the third recess 38. The second protrusion 74 is disposed on the opposite side of the second recess 36 from the first recess 34 and the third recess 38, and the third protrusion 76 is the first recess 34 and the second recess 36 of the third recess 38. It is arrange | positioned on the substantially opposite side. Further, the surfaces of the first protrusion 72, the second protrusion 74, and the third protrusion 76 on the leg plate 16 side are arranged perpendicular to the axial direction of the first recess 34, the second recess 36, and the third recess 38.

  A substantially plate-shaped gear cover 78 made of resin as a restricting member is assembled (attached) to the lower portion of the gear housing 30 on the side opposite to the leg plate 16. The lower opening 32A of the lower recess 32 of 30 is closed.

  The lower portion of the gear cover 78 is provided with a first closed portion 80 having a substantially bottomed cylindrical shape as a limiting portion, and the upper portion of the gear cover 78 is a second portion having a substantially bottomed cylindrical shape as an additional limiting portion. A closing portion 82 and a third closing portion 84 are provided, and the axial directions of the first closing portion 80, the second closing portion 82, and the third closing portion 84 are arranged in parallel with the output shaft 28A of the motor 28, respectively. Yes. The first closing portion 80, the second closing portion 82, and the third closing portion 84 are superposed and arranged in the radial direction, and the first closing portion 80, the second closing portion 82, the third closing portion 84, Are not communicated with each other without being provided with a peripheral wall at a portion where the interiors overlap each other. The first closing portion 80 has a larger diameter than the second closing portion 82 and the third closing portion 84, and the second closing portion 82 has a smaller diameter than the third closing portion 84.

  The first closing portion 80, the second closing portion 82, and the third closing portion 84 close the lower openings 32A in the first recess 34, the second recess 36, and the third recess 38 of the lower recess 32 of the gear housing 30, respectively. The first closing portion 80, the second closing portion 82, and the third closing portion 84 are arranged coaxially with the first recess 34, the second recess 36, and the third recess 38, respectively, and the peripheral walls are respectively the first recesses. 34, the second recess 36 and the third recess 38 are fitted to the peripheral walls.

  On the outside of the peripheral wall of the first closing portion 80, the second closing portion 82, and the third closing portion 84, a first engaging claw 86 as an engaging portion, a second engaging claw 88 as an additional engaging portion, and a second engaging portion, respectively. The three engaging claws 90 are integrally provided, and the first engaging claws 86 are disposed on the opposite side of the first closing portion 80 from the second closing portion 82 and the third closing portion 84, and The claw 88 is disposed on the opposite side of the second closing portion 82 from the first closing portion 80 and the third closing portion 84, and the third engaging claw 90 is connected to the first closing portion 80 of the third closing portion 84. And it is arrange | positioned on the opposite side to the 2nd closed part 82 substantially.

  The first engaging claw 86 is provided with a pair of first axial extending portions 86A as axial extending portions (opening direction extending portions) and a first circumferential extending portion 86B as a circumferential extending portion. The portion 86A extends from the first closed portion 80 in the axial direction (opening direction of the lower opening 32A) of the first closed portion 80 (projects toward the gear housing 30), and the first circumferentially extended portion 86B includes the first closed portion 80. Extending in the circumferential direction (circumferential direction of the lower opening 32A) and extending at both ends are connected to the extending tip of the first axial extending portion 86A. In addition, the connection part of each 1st axial extending part 86A and the 1st circumferential extending part 86B is contained in each 1st axial extending part 86A, and is not contained in the 1st circumferential extending part 86B.

  The second engagement claw 88 is provided with a pair of second diameter extending portions 88A, a pair of second shaft extending portions 88B, and a second circumferential extending portion 88C. The second diameter extending portions 88A are second closed. The second axially extending portion 88B extends from the portion 82 to the outside of the second closed portion 82 in the substantially radial direction, and the axial direction of the second closed portion 82 from the extending tip of the second radially extended portion 88A (gear housing 30 side). The second circumferentially extending portion 88C extends toward the circumferential side of the second closed portion 82 (parallel to the tangential direction), and both ends of the extending portion are connected to the extending end of the second axially extending portion 88B. In addition, the connection part of each 2nd diameter extending part 88A and each 2nd axial extending part 88B is contained in each 2nd axial extending part 88B, and is not contained in each 2nd diameter extending part 88A. Furthermore, the connection part of each 2nd axial extending part 88B and the 2nd circumferential extending part 88C is contained in each 2nd axial extending part 88B, and is not contained in the 2nd circumferential extending part 88C.

  The third engaging claw 90 is provided with a pair of third diameter extending portions 90A, a pair of third shaft extending portions 90B, and a third circumferential extending portion 90C, and the third diameter extending portions 90A are third closed. The third axially extending portion 90B extends from the portion 84 to the outside of the third closed portion 84 in the substantially radial direction, and the axial direction of the third closed portion 84 from the extending tip of the third radial extended portion 90A (gear housing 30 side). The third circumferential extending portion 90C extends toward the circumferential side of the third closed portion 84 (parallel to the tangential direction), and both ends of the stretching are connected to the extending tip of the third axial extending portion 90B. In addition, the connection part of each 3rd diameter extending part 90A and each 3rd axis extending part 90B is included in each 3rd axis extending part 90B, and is not included in each 3rd diameter extending part 90A. Furthermore, the connection part of each 3rd axial extension part 90B and the 3rd circumferential extension part 90C is contained in each 3rd axial extension part 90B, and is not contained in the 3rd circumferential extension part 90C.

  The first circumferential extending portion 86B of the first engaging claw 86, the second circumferential extending portion 88C of the second engaging claw 88, and the third circumferential extending portion 90C of the third engaging claw 90 are respectively in the center in the extending direction. The gear housing 30 is engaged (hooked) with a first protrusion 72 on the peripheral wall of the first recess 34, a second protrusion 74 on the peripheral wall of the second recess 36, and a third protrusion 76 on the peripheral wall of the third recess 38. As a result, the gear cover 78 is assembled to the gear housing 30.

  The first engaging claw 86 is elastically deformed and engaged with the first protrusion 72 mainly at a portion other than the engaging portion with the first protrusion 72 of the first circumferential extending portion 86B. Further, since the first engagement claw 86 does not have a portion extending in the radial direction (the direction perpendicular to the circumference of the lower opening 32A) of the first closing portion 80, the first closing portion 80 diameter of the first engagement claw 86 is not provided. There is no elastic deformation part in the extending part to the direction side. For this reason, the first part of the elastic deformation portion (the portion other than the engaging portion with the first protrusion 72 of the first circumferential extending portion 86B) in the extending portion of the first engaging claw 86 toward the first closing portion 80 in the circumferential direction side. The total amount of minimum extension in the circumferential direction of the closed portion 80 (along the first closed portion 80 circumferential direction) (2 × X1 in FIG. 1 and at least the first protrusion 72 in the circumferential direction of the first closed portion 80 at least. The amount of elastic deformation of the first engaging claw 86 extending in the radial direction of the first closing portion 80 in the radial direction of the first closing portion 80 (in the radial direction of the first closing portion 80). In comparison with the sum of the minimum amount of stretching (along (0)).

  Further, the extending portion of the first engaging claw 86 extending in the circumferential direction of the first closing portion 80 has an inclination angle in the extending direction with respect to the radial direction of the first closing portion 80 as viewed from the axial direction of the first closing portion 45. It is sufficient if the part is at least °. Furthermore, the extending portion of the first engaging claw 86 extending in the radial direction of the first closing portion 80 has an inclination angle in the extending direction with respect to the radial direction of the first closing portion 80 as viewed from the axial direction of the first closing portion 45. It may be a portion less than °.

  The second engaging claws 88 are elastically deformed into the second protrusions 74 mainly at portions other than the engaging portions of the second protrusions 88 </ b> A and the second protrusions 74 of the second circumferential extending portions 88 </ b> C. Is engaged. Further, the second circumferential extending portion 88 </ b> C is substantially equal (slightly larger) in the extending amount in the circumferential direction of the second closed portion 82 than the second protrusion 74. For this reason, the second of the elastically deformed portion (the portion other than the engaging portion with the second protrusion 74 of the second circumferential extending portion 88C) in the extending portion of the second engaging claw 88 toward the second closing portion 82 in the circumferential direction. The sum of the minimum amount of extension in the circumferential direction of the closed portion 82 (substantially 0) is the elastic deformation portion (each second diameter extended portion 88A) in the extended portion of the second engagement claw 88 extending in the radial direction of the second closed portion 82. The second closed portion 82 is made smaller than the sum of the minimum amount of extension in the radial direction (2 × Y2 in FIG. 1).

  The third engagement claws 90 are elastically deformed into the third projections 76 mainly at portions other than the engagement portions between the third diameter extension portions 90A and the third projections 76 of the third circumferential extension portions 90C. Is engaged. Further, the third circumferential extending portion 90 </ b> C is substantially equal (slightly larger) in the extending amount in the circumferential direction of the second closed portion 82 than the third protrusion 76. For this reason, the third of the elastically deformed portion (the portion other than the engaging portion with the third protrusion 76 of the third circumferential extending portion 90C) in the extending portion of the third engaging claw 90 toward the third closing portion 84 in the circumferential direction side. The total of the minimum amount of extension in the circumferential direction of the closed portion 84 (substantially 0) is the elastic deformation portion (each third diameter extended portion 90A) in the extended portion of the third engagement claw 90 extending in the radial direction of the third closed portion 84. The third closed portion 84 is made smaller than the sum of the minimum amount of extension in the radial direction (2 × Y3 in FIG. 1).

<Operation and effect of the present embodiment>
Next, the operation and effects of the webbing take-up device 10 will be described.

  In the webbing retractor 10, when the ECU predicts a vehicle collision, the motor 28 is operated. When the output shaft 28A is rotated by the operation of the motor 28, the output gear 42 provided on the output shaft 28A transmits the rotation of the output shaft 28A to the large-diameter gear 48 of the two-stage gear 46 to rotate the two-stage gear 46. . Further, since the small-diameter gear 50 of the two-stage gear 46 meshes with the ring holder 56 of the overload release mechanism 52, the rotation of the two-stage gear 46 causes the overload release mechanism 52 (the ring holder 56, the rotor 58, and a predetermined number) to rotate. , The overload release mechanism 52 rotates.

  The rotation of the overload release mechanism 52 is transmitted to the intermediate gear 60 that meshes with the rotor 58, and is further decelerated and transmitted to the clutch gear 64 of the clutch mechanism 62 that meshes with the intermediate gear 60. Rotates in the winding direction. In the clutch mechanism 62, when the clutch gear 64 rotates in the winding direction, a predetermined number of lock bars are rotated against the urging force by the clutch gear 64 and mesh with the ratchet teeth 66A of the ratchet gear 66. . Thereby, the ratchet gear 66 is rotated integrally with the clutch gear 64, and the spool 18 is rotated in the winding direction. By rotating the spool 18 in the winding direction in this way, the webbing 20 is wound around the spool 18 and a slight slack of the webbing 20 attached to the body of the vehicle occupant, so-called “slack” is removed. The

  Further, when a winding resistance load exceeding a predetermined load is applied to the webbing 20 from the occupant's body when the motor 28 is operated, the spool 18, the ratchet gear 66, a predetermined number of lock bars, a clutch gear 64. Further, the winding resistance load is transmitted to the rotor 58 via the intermediate gear 60, so that the rotation of the ring holder 56 relative to the rotor 58 is allowed by elastic deformation of a predetermined number of rings 59. Thereby, even if the ring holder 56 is rotated by the operation of the motor 28, the rotor 58 is not rotated, the spool 18 is not rotated in the winding direction, and the load applied to the occupant's body from the webbing 20 is less than a predetermined load. Limited to

  By the way, the first projection 72 on the circumferential wall of the first recess 34, the second projection 74 on the circumferential wall of the second recess 36, and the third projection 76 on the circumferential wall of the third recess 38 in the gear housing 30, respectively. The first engagement claw 86 (first circumferential extension portion 86B) of the peripheral wall, the second engagement claw 88 (second extension portion 88C) of the second closure portion 82 peripheral wall, and the third engagement of the third closure portion 84 peripheral wall. The gear cover 78 is assembled to the gear housing 30 by engaging the claw 90 (the third circumferential extending portion 90C).

  Further, the first engaging claw 86 is elastically deformed and engaged with the first protrusion 72 mainly at a portion other than the engaging portion with the first protrusion 72 of the first circumferentially extending portion 86 </ b> B, and the second engaging claw 88. Are elastically deformed and engaged with the second protrusions 74 mainly at portions other than the engagement portions of the second diameter extension portions 88A and the second circumferential extension portions 88C with the second protrusions 74, and third engagement claws 90 is elastically deformed and engaged with the third protrusions 76 mainly at portions other than the engagement portions of the third diameter extending portions 90 </ b> A and the third circumferential extending portions 90 </ b> C with the third protrusions 76.

  For this reason, at least one of the two-stage gear 46, the overload release mechanism 52, and the intermediate gear 60 is pivoted by an input of tilting power, vibration, or the like to at least one of the two-stage gear 46, the overload release mechanism 52, or the intermediate gear 60. Even when moving in the direction (gear cover 78 side), at least one axial movement of the two-stage gear 46, the overload release mechanism 52, and the intermediate gear 60 is the gear cover 78 (the first engagement claw 86, the second engagement claw). Is limited (restricted) by the elastic force of the joint claw 88 and the third engagement claw 90).

  Here, the first deformation portion (the portion other than the engaging portion of the first circumferential extending portion 86B with the first protrusion 72) in the extending portion of the first engaging claw 86 toward the first closing portion 80 in the circumferential direction is first. The total of the minimum amount of extension in the circumferential direction of the closing portion 80 (2 × X1 in FIG. 1) is the first closing portion of the elastically deformed portion in the extending portion of the first engaging claw 86 in the radial direction of the first closing portion 80. It is larger than the total (0) of the minimum amount of stretching in the 80 radial direction.

  For this reason, unlike the second engagement claw 88 and the third engagement claw 90, one first engagement claw 86 can apply an elastic force to the gear cover 78 in a wide range in the circumferential direction of the first closing portion 80. it can. As a result, the number of engaging claws (engaging portions) provided in the first closing portion 80 can be reduced, the assembling property of the gear cover 78 to the gear housing 30 can be improved, and the gear housing 30 can be improved. The assembled state of the gear cover 78 (the engaged state of the first engaging claw 86 with the first protrusion 72, the engaged state of the second engaging claw 88 with the second protrusion 74, and the third engaging claw 90) It is possible to reduce the inspection process (the visual confirmation process) of the engagement state with the three protrusions 76.

  Further, unlike the second engagement claw 88 and the third engagement claw 90, the first engagement claw 86 can be obtained even if the amount of extension of the first engagement claw 86 in the radial direction of the first closing portion 80 is reduced. The elastic force which the 1st engaging claw 86 acts on the 1st closed part 80 can be enlarged by enlarging the extending | stretching amount to the 1st closed part 80 circumferential direction side. As a result, the size (physique) of the gear cover 78 in the radial direction of the first closed portion 80 can be reduced, and the webbing retractor 10 can be reduced in space and reduced in size in the radial direction of the first closed portion 80.

  In addition, both longitudinal ends (the pair of first axial extending portions 86A) of the first engaging claws 86 are extended in the axial direction of the first closing portion 80, and the longitudinal intermediate portions ( The first circumferential extending portion 86 </ b> B) is stretched in the circumferential direction of the first closing portion 80, and the amount of stretching in the circumferential direction side of the first closing portion 80 in the longitudinal intermediate portion of the first engaging claw 86 is increased. . As a result, the first protrusion 72 can be easily engaged with the intermediate portion in the longitudinal direction of the first engagement claw 86, and the assembling property of the gear cover 78 to the gear housing 30 can be further improved.

  A pair of first shaft extending portions 86 </ b> A, second engagement claws 88, and third engagement claws 90 of the first engagement claws 86 are arranged on the gear cover 78 at substantially equal intervals in the circumferential direction. For this reason, the elastic force can be applied to the gear cover 78 in a balanced manner in the circumferential direction.

  In the present embodiment, the first engaging claw 86 is not provided with a portion extending in the radial direction of the first closing portion 80. However, the first extending portion (the extending direction with respect to the radial direction of the first closed portion 80) as a radially extending portion (circumferentially extending portion) extended to the first engaging claw 86 in the radial direction of the first closed portion 80. May be provided with a tilt angle of less than 45 ° when viewed from the axial direction of the first closing portion 80. In this case, for example, similarly to the second engaging claw 88 and the third engaging claw 90, the first shaft extending portion 86A is connected to the first closed portion 80 extending outward in the radial direction of the first diameter extending portion. To do.

  In the present embodiment, the first circumferential extending portion 86 </ b> B of the first engaging claw 86 is extended in the circumferential direction of the first closed portion 80. However, the first circumferential extending portion 86 </ b> B may be extended to the circumferential direction side of the first closed portion 80 (the inclination angle of the extending direction with respect to the radial direction of the first closed portion 80 is from the axial direction of the first closed portion 80. For example, the first circumferential extending portion 86 </ b> B may be extended parallel to the tangential direction of the first closed portion 80.

  Furthermore, in the present embodiment, the circumferential shape of the lower opening 32A (opening portion of the housing member) of the gear housing 30 is an arc shape. However, the circumferential shape of the opening of the housing member of the present invention may be another curved shape (particularly a curved shape) or a linear shape.

  In the present embodiment, the engaging portion of the present invention is applied to the first engaging claw 86. However, together with or instead of this, the engaging portion of the present invention may be applied to the second engaging claw 88, the third engaging claw 90, and the like.

  Further, the gear housing 30 is provided with the first protrusion 72, the second protrusion 74, and the third protrusion 76, and the gear cover 78 is provided with the first engagement claw 86, the second engagement claw 88, and the third engagement claw 90. . However, the gear housing 30 is provided with the first engaging claw 86 and the gear cover 78 is provided with the first protrusion 72. The gear housing 30 is provided with the second engaging claw 88 and the gear cover 78 is provided with the second protrusion 74. The configuration may be at least one of the configuration in which the third engagement claw 90 is provided in the gear housing 30 and the third protrusion 76 is provided in the gear cover 78.

  Further, in the present embodiment, the gears of the present invention (the output gear 42, the large diameter gear 48, the small diameter gear 50, the ring holder 56, the rotor 58, and the intermediate gear 60) are spur teeth. However, the gear of the present invention (at least one of the output gear 42, the large diameter gear 48, the small diameter gear 50, the ring holder 56, the rotor 58, and the intermediate gear 60) may be a helical tooth. In this case, even if the gear moves in the axial direction (gear cover 78 side) due to the rotation, the movement in the axial direction due to the rotation of the gear causes the gear cover 78 (the first engagement claw 86, the second engagement claw 88, and the third engagement). It can be limited (restricted) by the elastic force of the engaging claws 90.

  Further, in the present embodiment, the present invention is applied to the gear housing 30 and the gear cover 78. However, the present invention may be applied to, for example, the gear housing 30 and the spring cover 68 (restricting member). In such a case, an urging force (rotational force) is transmitted to the spool 18.

10 Webbing take-up device 18 Spool 20 Webbing 28 Motor (drive means)
28A Output shaft (support shaft)
30 Gear housing (housing member)
32A lower opening (opening)
40 Driving force transmission mechanism (transmission mechanism)
42 Output gear (gear)
44 Double shaft (support shaft)
46 Two-stage gear (gear)
52 Overload release mechanism (gear)
54 Support shaft (support shaft)
60 Intermediate gear (gear)
62 Clutch mechanism (gear)
72 1st protrusion (engaged part)
78 Gear cover (restricting member)
86 1st engagement nail (engagement part)

Claims (3)

A spool on which a webbing to be mounted on a vehicle occupant is wound;
A transmission mechanism for transmitting rotational force to the spool;
An opening provided with an accommodating member for accommodating the transmission mechanism;
A limiting member that restricts movement of the transmission mechanism toward the opening by being assembled to the housing member;
An engaged portion provided on one of the accommodating member or the restricting member;
The other of the housing member or the restricting member is provided so as to be elastically deformable, and the total amount of stretching in the circumferential direction of the opening in the stretched portion in the circumferential direction of the opening is perpendicular to the circumference of the opening. The restricting member is assembled to the housing member by being larger than the total amount of stretching in the direction perpendicular to the circumferential direction of the opening at the portion extending in the direction side, and being engaged with the engaged portion. An engaging portion to be attached;
A webbing take-up device comprising: Equipped with a motor that generates rotational force,
The transmission mechanism is
A support shaft whose axial direction is the opening direction of the opening;
A gear supported by the support shaft and transmitting the rotational force generated by the motor to the spool;
The webbing take-up device according to claim 1, comprising:   The said engaging part is extended to the said opening part periphery orthogonal direction side or the said opening part opening direction side in a longitudinal direction both ends, and is extended to the said opening part circumferential direction side in a longitudinal direction intermediate part. 2. The webbing take-up device according to 2.

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