JP5919097B2 - Seat belt retractor - Google Patents

Description

  The present invention relates to a seatbelt retractor for preventing webbing from being pulled out in an emergency.

Conventionally, various seat belt retractors for preventing webbing from being pulled out in an emergency have been proposed.
For example, a winding shaft having a bobbin around which a webbing is wound is rotatably mounted on each of the opposing base side plates of a base having a U-shaped cross section via left and right plastic bushes. Yes. A winding spring device is disposed on one end side of the winding shaft and is always urged in the direction of winding the webbing.

  In addition, an emergency lock mechanism for preventing the webbing from being pulled out in an emergency is disposed on the other end side of the winding shaft. Furthermore, the emergency lock mechanism is covered with a sensor cover disposed outside the base side plate. In addition, the bottom wall of the sensor cover has a protrusion that is a protrusion protruding toward the end of the winding shaft, and the protrusion can elastically bias the winding shaft in the axial direction. Thus, there is a retractor for a seat belt provided with an elastically deformable thin portion formed around the protrusion (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-291094

    However, in the seatbelt retractor described in Patent Document 1 described above, since the projecting portion projects from the bottom wall portion of the sensor cover toward the end of the winding shaft, the height of the sensor cover However, there is a problem that the seat belt retractor is difficult to reduce in the axial direction of the bobbin because the height of the protrusion is higher than the end of the winding shaft in the axial direction.

  Accordingly, the present invention has been made to solve the above-described problems, and is a seat belt retractor capable of suppressing backlash in the direction of the rotation axis of the winding drum and reducing the size in the direction of the rotation axis. The purpose is to provide.

A seatbelt retractor according to claim 1 for achieving the above object, phase a housing comprising a pair of side wall portions opposing, is rotatably accommodated inside the pair of side wall portions facing each of said housing webbing A winding drum that rotates in the webbing pull-out direction when the webbing is pulled out, and at least one side wall portion of the pair of side wall portions is disposed on the outer side in the rotation axis direction of the winding drum. A support member that rotatably supports a rotating shaft that protrudes from one end facing the one side wall of the take-up drum, and the support member is disposed in the center of the take-up drum. a rotation support portion that rotatably supports the rotation shaft of the one end side, pressed and urged the winding drum extends in the circumferential direction from the rotating support to the side wall inside the one That consists of a predetermined depth curved bottom portion to the take-up drum side, when the support member is rotatably supporting the rotation shaft of the one end of the winding drum, the bottom surface portion of the support member bullet and sex deformed, characterized in that said rotating support presses urging the winding drum to the side wall inside the one.

The seat belt retractor according to claim 2 is the seatbelt retractor according to claim 1, provided on the one end side of the winding drum, the winding the winding in an emergency drum in the webbing pull-out direction a locking mechanism for preventing rotation, with prior Symbol mounted to the rotation shaft outward of the winding drum of the one side wall portion to accommodate the locking mechanism, the rotation axis of said one end of the winding drum A mechanism cover that rotatably supports the support member, wherein the support member is the mechanism cover .

A seatbelt retractor according to a third aspect is the seatbelt retractor according to the first aspect, wherein the seatbelt retractor is attached to the outer side in the rotation axis direction of the winding drum of the one side wall portion, and the winding drum is comprising a winding mounting biasing mechanism for always-on pivot urging the webbing take-up direction, the winding mounting biasing mechanism is to turn biased rotation shaft of the one end side of the take-up drum in the webbing take-up direction the spring case and the spiral spring, which is attached to the side wall portion of the front Symbol one by accommodating the spiral spring that, the conjunction is disposed between the spiral spring and the one side wall portion, the winding is attached to the spring case It has a spring seat for rotatably supporting the one end side rotating shaft of the drum taken, wherein the support member is pre-characterized kiss pulling sheets der Rukoto.

Furthermore, a seat belt retractor according to claim 4 is the seatbelt retractor according to any one of claims 1 to 3, wherein the support member, rotatably supporting said one end of said winding drum when the said bottom part by elastic deformation, characterized in that it is formed to be substantially parallel to the one side wall portion.

In the seatbelt retractor according to claim 1, the rotation shaft protruding from one end side facing the one side wall portion of the take-up drum is provided on the bottom surface portion of the support member disposed outside the one side wall portion. While being rotatably supported by the rotation support portion, the bottom surface portion of the support member is elastically deformed, and the winding drum is pressed and urged to the inside of one side wall portion by the rotation support portion . As a result, it is possible to suppress backlash in the direction of the rotation axis of the take-up drum, and it is possible to bring the bottom surface of the support member closer to one end side of the take-up drum, thereby reducing the size of the seat belt retractor in the direction of the rotation axis. Can be achieved.

In the seatbelt retractor according to claim 2, the mechanism cover that houses the lock mechanism for preventing the winding drum from rotating in the webbing pull-out direction in an emergency is provided on the outer side in the rotational axis direction of the winding drum on one side wall. By attaching to the rotary drum, the rotary shaft on one end side of the take-up drum is rotatably supported by a rotation support portion provided on the bottom surface portion of the mechanism cover, and the take-up drum is supported by one of the rotation support portions of the mechanism cover. It is pressed and urged to the inside of the side wall .

  Thereby, the backlash of the winding drum in the rotation axis direction can be suppressed by attaching the mechanism cover to the outer side in the rotation axis direction of the winding drum on one side wall portion. In addition, the bottom surface portion of the mechanism cover on which the rotation support portion is provided can be brought closer to one end side of the take-up drum, and the seat belt retractor can be downsized in the rotation axis direction.

Further, in the seatbelt retractor according to claim 3, scan pulling sheet, while being disposed between the spiral spring and the one side wall portion that is accommodated in the spring case is attached to the spring case. When the spring case is attached to the outside of the one side wall portion and the spring seat is arranged outside the one side wall portion, the rotating shaft on one end side of the winding drum is provided on the bottom surface portion of the spring seat. The take-up drum is pressed and urged to the inside of one side wall portion by the rotation support portion of the spring seat .

As a result, by attaching the spring case to the outer side in the rotation axis direction of the winding drum on one side wall portion, it is possible to suppress backlash in the rotation axis direction of the winding drum via the rotation support portion of the spring seat. Further, the bottom surface portion provided with the rotation support portion of the spring seat can be brought closer to one end side of the take-up drum, and the seat belt retractor can be downsized in the rotation axis direction.

Furthermore , in the seatbelt retractor according to claim 4 , when the support member is attached to the outside of the one side wall portion and the rotation support portion rotatably supports the rotation shaft on one end side of the winding drum, The bottom surface of the support member is substantially parallel to the one side wall . Thereby, the clearance gap between the bottom face part of a supporting member and one side wall part can be minimized, and the further size reduction of the rotating shaft direction of the retractor for seatbelts can be achieved.

1 is an external perspective view of a seatbelt retractor according to a first embodiment. It is the perspective view which decomposed | disassembled the seatbelt retractor of FIG. 1 according to the unit. It is the perspective view which decomposed | disassembled the seatbelt retractor of FIG. 1 according to the unit. It is a disassembled perspective view of a housing unit. It is sectional drawing of the retractor for seatbelts of FIG. It is a disassembled perspective view of a winding drum unit. It is a disassembled perspective view of a pretensioner unit. It is a disassembled perspective view of a ratchet gear, a winding spring unit, and a lock unit. It is a disassembled perspective view of a ratchet gear, a winding spring unit, and a lock unit. It is sectional drawing explaining the attachment state of a spring case. It is sectional drawing of a mechanism cover. It is a partially cutaway sectional view in which a part such as a bottom surface of a mechanism cover of the lock unit is cut away. It is a principal part expanded sectional view containing the winding spring unit and lock unit of FIG. It is an external appearance perspective view of the seatbelt retractor which concerns on 2nd Embodiment. It is the perspective view which decomposed | disassembled the seatbelt retractor of FIG. 14 according to the unit. It is the perspective view which decomposed | disassembled the seatbelt retractor of FIG. 14 according to the unit. It is a disassembled perspective view of a winding drum unit. It is a disassembled perspective view of a lock unit. It is sectional drawing of a mechanism cover. It is a disassembled perspective view of a winding spring unit. It is a disassembled perspective view of a winding spring unit. It is sectional drawing of a spring seat. It is sectional drawing of the retractor for seatbelts of FIG.

  DETAILED DESCRIPTION Hereinafter, a seat belt retractor according to the present invention will be described in detail with reference to the drawings based on a first embodiment and a second embodiment.

[Schematic configuration]
First, a schematic configuration of the seatbelt retractor 1 according to the first embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is an external perspective view of a seatbelt retractor 1 according to the first embodiment. 2 and 3 are exploded perspective views of the seat belt retractor 1 for each unit.
As shown in FIGS. 1 to 3, the seat belt retractor 1 is a device for winding a webbing 3 of a vehicle, and includes a housing unit 5, a winding drum unit 6, a pretensioner unit 7, and a winding unit. A spring unit 8 and a lock unit 9 are included.

  The lock unit 9 is fixed to one side wall portion 12 of the housing 11 constituting the housing unit 5 by means of each ny latch 9A and each locking hook 9B formed integrally with the mechanism cover 111 (see FIG. 8). . The lock unit 9 constitutes a lock mechanism 10 (see FIG. 12) that stops the withdrawal of the webbing 3 in response to a sudden withdrawal of the webbing 3 or a rapid acceleration change of the vehicle. The take-up spring unit 8 winds the lock unit 9 as described later via three plate-like locking pieces 8A (see FIG. 9) protruding from the outer periphery of the spring case 107 (see FIG. 8). The drum unit 6 is fixed on the outer side in the rotation axis direction (see FIG. 10).

  Further, the pretensioner unit 7 is arranged on the other side wall portion 13 opposite to the side wall portion 12 of the housing 11 formed in a substantially U shape in plan view, and on the outer side in the rotation axis direction of the winding drum unit 6 of the pretensioner unit 7. Are screwed by the respective screws 15 inserted therethrough. The pretensioner unit 7 includes a stopper pin 16 inserted into the side wall portion 13 from the outer side in the rotation axis direction of the winding drum unit 6 of the pretensioner unit 7, and the rotation of the winding drum unit 6 of the side wall portion 13 through the stopper pin 16. It is fixed by a push nut 18 inserted from the inside in the axial direction.

  The winding drum unit 6 around which the webbing 3 is wound is rotatable between a lock unit 9 fixed to the side wall 12 of the housing unit 5 and a pretensioner unit 7 fixed to the side wall 13. Supported. The winding drum unit 6 is always urged in the winding direction of the webbing 3 by a winding spring unit 8 fixed outside the lock unit 9.

[Schematic configuration of housing unit]
Next, a schematic configuration of the housing unit 5 will be described with reference to FIGS.
FIG. 4 is an exploded perspective view of the housing unit 5.
As shown in FIGS. 2 to 4, the housing unit 5 includes a housing 11, a bracket 21, a protector 22, a pawl 23, a pawl rivet 25, a torsion coil spring 26, a sensor cover 27, and a vehicle acceleration sensor 28. And connecting members 32 and 33 and a rivet 61.

  Further, the housing 11 is formed in a substantially U shape in plan view by extending a back plate portion 31 fixed to the vehicle body and side wall portions 12 and 13 facing each other from both side edge portions of the back plate portion 31. It is made of steel. Further, the side wall portions 12 and 13 are connected to each other by connecting members 32 and 33 each having a horizontally long thin plate shape that is long in the direction of the rotation axis of the winding drum unit 6. In addition, an opening is formed in the central portion of the back plate portion 31 so as to reduce the weight and limit the amount of webbing 3 accommodated.

  Further, the side wall portion 12 is formed with a through hole 36 into which the ratchet gear 35 of the winding drum unit 6 is inserted while forming a predetermined gap (for example, a gap of about 0.5 mm). The inner peripheral edge of the through hole 36 is configured to be recessed to the winding drum unit 6 side by a predetermined depth inward in the central axis direction, and to be opposed to the ratchet gear 35 of the winding drum unit 6.

  Further, a peripheral edge facing the tip 37 (the other end) side portion 37 including the engaging teeth 23A and 23B of the pawl 23 obliquely below (through the diagonally lower left in FIG. 4) of the through hole 36. The notch portion 38 is cut out to a depth in which the distal end portion 37 is accommodated from the portion to the outside in the turning direction of the pawl 23 (the turning direction is away from the ratchet gear 35 of the pawl 23). Is formed. A through hole 41 for rotatably mounting the pawl 23 is formed on the side of the notch 38 on the back plate 31 side. In addition, an arcuate guide portion 38 </ b> A is formed coaxially with the through hole 41 at a portion where the pawl 23 on the through hole 41 side of the cutout portion 38 abuts.

  On the other hand, a portion of the pawl 23 made of steel or the like that slides in contact with the guide portion 38A has a height substantially equal to the thickness of the side wall portion 12 and has the same radius of curvature as the guide portion 38A. A stepped portion 37A that is recessed in an arc is formed. In addition, the pawl 23 is inserted into a guide hole 156 (see FIG. 8) of the clutch 125 that constitutes the lock unit 9 at the front end of the side of the pawl 23 on the outer side in the rotational axis direction (the front side in FIG. 4). Guide pins 42 are erected.

  A through hole 43 through which the pawl rivet 25 is inserted is formed at the base end portion (one end portion) of the pawl 23 and is rotated from the peripheral portion of the through hole 43 to the through hole 41 of the side wall portion 12. A cylindrical boss portion 45 that can be inserted is erected at a height substantially equal to the thickness dimension of the side wall portion 12. The pawl 23 can be rotated by a pawl rivet 25 fitted into the through hole 43 from the outside of the side wall portion 12 in a state where the boss portion 45 is inserted into the through hole 41 of the side wall portion 12 from the inside of the housing 11. Fixed to. Accordingly, the engaging teeth 23A and 23B of the pawl 23 and the ratchet gear portion 35A formed on the outer peripheral surface of the ratchet gear 35 are arranged so as to be substantially flush with the outer surface of the side wall portion 12.

  The head of the pawl rivet 25 is formed in a disk shape having a larger outer diameter than the through hole 41 and a predetermined thickness (for example, a thickness of about 1.5 mm). The torsion coil spring 26, which functions as an example of a return spring, is disposed so as to surround the head of the pawl rivet 25 with one winding, and one end side 26 </ b> A is attached to the guide pin 42 of the pawl 23. . The wire diameter of the torsion coil spring 26 is approximately half the height of the head of the pawl rivet 25 (for example, the wire diameter is about 0.6 mm). Accordingly, the height of one turn of the torsion coil spring 26 is set to be substantially the same as the height of the head of the pawl rivet 25.

  Further, the other end side 26B of the torsion coil spring 26 passes through the side wall portion 12 side of the one end side 26A so as to be slidable on the side wall portion 12, and then the inner side direction of the side wall portion 12 (in FIG. 4, the back side of the side wall portion 12). Direction), and is inserted through a mounting hole 46 formed in the side wall portion 12. Further, the end portion of the other end side 26B is bent into a substantially U shape and is brought into contact with the inner surface of the side wall portion 12 to constitute a retaining portion. As a result, the pawl 23 is biased by the torsion coil spring 26 so as to rotate toward the back side of the notch 38 (in the counterclockwise direction in FIG. 3), and the distal end including the engaging teeth 23A and 23B. The side portion 37 is in contact with the back side of the notch 38. Accordingly, the pawl 23 is urged to rotate in a direction away from the ratchet gear 35 by the torsion coil spring 26.

  Further, as shown in FIGS. 2 to 4, below the through hole 36 of the side wall portion 12 (downward in FIG. 4), below the central axis of the through hole 36 (downward in FIG. 4). To the back plate portion 31 side, a substantially rectangular opening 47 is formed. In addition, a shallow substantially box-shaped sensor cover 27 having a substantially square cross section substantially the same as the opening 47 is fitted into the opening 47 from the outside (the front side in FIG. 4). The resin-made sensor cover 27 has a flange formed on the opening-side peripheral edge abutting on the outer peripheral edge of the opening 47 (the front-side peripheral edge in FIG. 4), and the sensor cover. 27, a pair of locking claws 27A (in FIG. 4, the locking claw 27A on the upper end surface is shown) projecting from both ends in the up-down direction are shown in FIG. It is inserted in the back side of the direction both ends and is elastically locked.

  Further, the vehicle acceleration sensor 28 includes a resin-made sensor holder 51 having a substantially box shape opened to the upper side in the vertical direction (upper side in FIG. 4) and having a mortar-shaped mounting portion formed on the bottom surface portion, Inertial mass 52 formed in a spherical body of metal such as steel and movably mounted on the mounting portion, and placed on the upper side in the vertical direction of inertial mass 52 and opposite to pawl 23 From the sensor lever 53 made of resin, the end edge portion (the right end edge portion in FIG. 4) is supported by the sensor holder 51 so as to be swingable vertically (in the vertical direction in FIG. 4). It is configured.

  Then, the vehicle acceleration sensor 28 is fitted into the sensor cover 27, and a pair of locking claws 51 </ b> A (one engagement in FIG. 4) provided on both side surfaces facing both side walls in the sensor cover 27 of the sensor holder 51. The vehicle acceleration sensor 28 is attached to the housing 11 via the sensor cover 27 by inserting and locking the pawl 51A into each locking hole 27B of the sensor cover 27.

  Further, the side wall portion 12 has three corners, that is, both corners of an upper edge portion (upper edge portion in FIG. 4) and a lower portion of the through hole 36 (downward direction in FIG. 4). Each mounting hole 55 into which each ny latch 9A of the lock unit 9 is fitted and attached is formed. In addition, each locking piece to which each locking hook 9 </ b> B of the lock unit 9 is elastically locked is located at the center of the left and right side edges of the side wall 12 (the vertical center in FIG. 4). 56 is formed so as to protrude perpendicularly to the rotation axis of the winding drum unit 6.

  Further, a through hole 57 through which the winding drum unit 6 is inserted is formed in the side wall portion 13 at the center portion. Further, the side wall portion 13 includes a substantially lower end edge portion (lower end edge portion in FIG. 2), a corner portion on the connecting member 33 side, and an upper end edge portion (upper end edge portion in FIG. 2). The screw holes 58 into which the screws 15 are screwed are formed by burring in the direction of the pretensioner unit 7 at the corners on the back plate portion 31 side. Further, a through hole 59 through which the stopper pin 16 is inserted is formed in the side wall portion 13 at a corner portion on the connecting member 32 side of the upper end edge portion (the upper end edge portion in FIG. 2).

  Moreover, the bracket 21 attached to each upper end edge (the upper end edge in FIG. 2) of the back plate 31 by each rivet 61 is formed of a steel material or the like, and the upper end edge of the back plate 31 A laterally long through hole 62 extending in the width direction of the back plate portion 31 from which the webbing 3 is pulled out is formed in an extending portion extending in the direction of the connecting member 32 at a substantially right angle from the side, and is formed of a synthetic resin such as nylon. A horizontally long frame-shaped protector 22 is fitted. Further, a bolt insertion hole 63 through which a bolt is inserted when being attached to a fastening piece (not shown) of the vehicle is formed in the lower end portion (the lower end portion in FIG. 2) of the back plate portion 31. .

[Schematic configuration of winding drum unit]
Next, a schematic configuration of the winding drum unit 6 will be described with reference to FIGS. 2, 3, 5, and 6. FIG. 5 is a sectional view of the seat belt retractor 1. FIG. 6 is an exploded perspective view of the winding drum unit 6.
As shown in FIGS. 5 and 6, the winding drum unit 6 includes a winding drum 65, a torsion bar 66, a wire 67, and a ratchet gear 35.

  As shown in FIGS. 2, 3, 5, and 6, the winding drum 65 is formed by aluminum die casting, zinc die casting, or the like, and is formed in a substantially cylindrical shape in which the end surface portion on the pretensioner unit 7 side is closed. Has been. Further, an end edge portion on the pretensioner unit 7 side in the axial direction of the winding drum 65 extends in the radial direction from the outer peripheral portion, and further in a substantially right-angled outward direction (the left side direction in FIG. 5). An extended flange portion 68 is formed. Further, an inner gear 69 is formed on the inner peripheral surface of the flange portion 68 to which each clutch pawl 102 (see FIG. 7) is engaged and the rotation of the pinion gear 71 is transmitted in the event of a vehicle collision.

  A cylindrical boss 72 is erected at the center position of the end surface of the winding drum 65 on the pretensioner unit 7 side. The boss 72 is fitted into a bearing 73 formed of a synthetic resin material such as polyacetal, and the base end portion of the boss 72 is brought into contact with the bearing 73. Then, one end side of the winding drum unit 6 is rotatably supported by a boss portion 71D of a pinion gear 71 constituting the pretensioner unit 7 via a bearing 73.

  Further, a shaft hole 65A having a draft angle formed so as to be gradually reduced along the central axis is formed inside the winding drum 65. A spline groove into which a spline 66A formed at one end of a torsion bar 66 formed of a steel material or the like is press-fitted is formed at the end of the shaft hole 65A on the flange portion 68 side.

  Further, the torsion bar 66 is formed of a shaft portion 66C formed of a steel material and having a circular cross section, and splines 66A and 66B formed at both ends of the shaft portion 66C. The torsion bar 66 is inserted into the shaft hole 65A of the take-up drum 65 and press-fitted until it contacts the flange portion 68, so that the torsion bar 66 is press-fitted and fixed in the take-up drum 65 so as not to be relatively rotatable. Is done.

  Further, a flange portion 75 having a substantially circular shape when viewed from the front is formed on an end edge portion of the winding drum 65 on the lock unit 9 side in the axial direction, extending from the outer peripheral surface slightly inward in the axial direction in the radial direction. Has been. A cylindrical stepped portion 76 having a slightly smaller outer diameter is formed on the outer side in the axial direction from the flange portion 75. The stepped portion 76 is provided so as to surround the spline 66B on the other end side of the torsion bar 66 press-fitted into the shaft hole 65A with a predetermined gap.

  In addition, a bent portion 67A at one end of a wire 67 having a circular cross section made of a metal material such as stainless steel is formed on the outer peripheral portion of a step portion 76 having a substantially circular shape in front view formed on the outer surface in the axial direction of the flange portion 75. A holding-side bending path 77 in which the is inserted and held is integrally formed.

  As shown in FIG. 6, the holding-side bending path 77 includes a convex portion 78 that protrudes from the outer surface in the axial direction of the flange portion 75 and is formed in a substantially trapezoidal shape facing inward in the radial direction when viewed from the front, and the outer periphery of the stepped portion 76. A concave portion 79 that faces the convex portion 78 and a front view from the outer peripheral surface of the stepped portion 76 that is a little away from the end portion of the concave portion 79 on the counterclockwise side of the front view (the counterclockwise side in FIG. 6). The groove portion 81 is formed in the diagonally inward direction inclined in the counterclockwise direction, and the outer peripheral surface between the concave portion 79 of the stepped portion 76 and the groove portion 81.

  The ratchet gear 35 is formed by aluminum die casting, zinc die casting, or the like. The ratchet gear portion 35A is formed in the outer peripheral portion with a substantially ring shape in the shaft cross section, and a cylindrical fixed boss 82 is erected at the inner central position. Yes. A spline groove into which a spline 66B formed on the other end side of the torsion bar 66 is press-fitted is formed on the inner peripheral surface of the fixed boss 82. Further, the inner peripheral portion of the ratchet gear portion 35A is formed to have an inner diameter into which the stepped portion 76 of the winding drum 65 can be inserted.

  Further, the ratchet gear 35 has a ring shape in a front view from the end surface portion of the ratchet gear portion 35A on the winding drum 65 side to the outer side in the radial direction from the outer diameter of the flange portion 75 of the winding drum 65. Further, a flange portion 83 is formed which extends from the outer periphery of a predetermined center angle (for example, a center angle of about 60 degrees) to the radially outer side in a substantially trapezoidal shape with a narrow front end on the front view. . Further, the outer diameter of the flange portion 83 is formed to be approximately the same as the outer diameter of the flange portion 68 of the winding drum 65.

  Further, the inner side surface of the substantially trapezoidal trapezoidal trapezoidal portion 83 </ b> A, which extends outward in the radial direction of the flange portion 83 and has a narrow front view, faces the outer side in the rotation axis direction from the trapezoidal portion 83 </ b> A. A protruding portion 84 (see FIG. 9) having a generally chevron shape in front view, into which a bent portion 67B having a substantially inverted U-shape in front view is fitted, is formed in a substantially central portion.

  Further, an inner surface of the flange portion 83 on the winding drum 65 side is erected with an inner diameter that is slightly larger than the outer diameter of the flange portion 75 of the winding drum 65, and along the outer peripheral portion of the trapezoidal portion 83A. A flange portion 85 having a generally oval shape in front view is formed. Further, the inner peripheral portion of the flange portion 85 and the outer peripheral portion of the convex portion 84 form a deformation imparting bending path having a generally inverted U shape in front view through which the wire 67 is slid and guided.

  Accordingly, first, a bent portion 67A bent in a substantially S shape on one end side of the wire 67 is fitted into a holding-side bent path 77 formed in the flange portion 75 and the stepped portion 76 of the winding drum 65. Further, a substantially inverted U-shaped bent portion 67B formed continuously from the bent portion 67A of the wire 67 is projected outward from the outer periphery of the flange portion 75. Further, an arc-shaped bent portion 67 </ b> C formed continuously with the bent portion 67 </ b> B of the wire 67 is disposed along the outer peripheral surface of the stepped portion 76.

  Subsequently, for attaching the ratchet gear 35 to the winding drum 65, first, a bent portion 67B having a substantially inverted U shape as viewed from the front of the wire 67 protruding outward from the outer periphery of the flange portion 75 of the winding drum 65 is provided. The ratchet gear 35 is fitted into a deformation imparted bending path formed on the outer peripheral portion of the convex portion 84 provided in the trapezoidal portion 83A of the flange portion 83.

  At the same time, the fixed boss 82 of the ratchet gear 35 is inserted into the stepped portion 76 of the take-up drum 65, and the spline 66B formed on the other end side of the torsion bar 66 is press-fitted into the spline groove of the fixed boss 82. . Accordingly, the wire 67 is disposed between the flange portion 75 of the winding drum 65 and the flange portions 83 and 85 of the ratchet gear 35, and the ratchet gear 35 is connected to the winding drum 65 via the torsion bar 66. On the other hand, it is mounted so as not to be relatively rotatable.

[Schematic configuration of pretensioner unit]
Next, a schematic configuration of the pretensioner unit 7 will be described with reference to FIGS. 2, 3, 5, and 7. FIG. 7 is an exploded perspective view of the pretensioner unit 7.
The pretensioner unit 7 is configured to rotate the take-up drum 65 in the webbing take-up direction in an emergency such as a vehicle collision to remove the slack of the webbing 3 and firmly restrain the occupant to the seat.

As shown in FIGS. 2, 3, 5, and 7, the pretensioner unit 7 includes a gas generation member 87, a pipe cylinder 88, a piston 89, a pinion gear 71, a clutch mechanism 91, and a bearing 73. ing.
The gas generating member 87 includes a gas generating agent such as explosive, and is configured to ignite the gas generating agent by an ignition signal from a control unit (not shown) and generate gas by combustion of the gas generating agent. Yes.

  The pipe cylinder 88 is formed as an L-shaped cylinder member in which a gas introduction part 88B is connected to one end of a linear piston guide cylinder part 88A. A gas generating member 87 is accommodated in the gas introducing portion 88B. Therefore, the gas generated by the gas generating member 87 is introduced into the piston guide cylinder portion 88A from the gas introduction portion 88B. In addition, an opening 92 is formed in the middle portion in the longitudinal direction on one side of the piston guide cylinder 88A, and a part of the pinion gear teeth 71A of the pinion gear 71 is disposed.

  The pipe cylinder 88 is sandwiched between the base plate 93 on the side wall 13 side of the housing 11 and the outer cover plate 95, and is sandwiched between the base block 96 and the cover plate 95. The screw 15 is attached and fixed to the outer surface of the side wall 13.

  Further, the pretensioner unit 7 is attached to the side wall portion 13 at the upper end portion of the piston guide cylinder portion 88A, and a stopper pin 16 that functions as a retaining member for the piston 89, a retaining member for the pipe cylinder 88, and a rotation stopper can be inserted. A pair of through holes 88C are formed to face each other.

  The piston 89 is formed of a metal member such as a steel material, has a substantially rectangular cross section that can be inserted from the upper end side of the piston guide cylinder portion 88A, and has a long shape as a whole. A rack 89A that meshes with the pinion gear teeth 71A is formed on the side surface of the piston 89 on the pinion gear 71 side. The end surface of the piston 89 on the gas generating member 87 side is formed as a circular end surface 89B corresponding to the cross-sectional shape of the piston guide cylinder portion 88A. A seal plate 97 made of a rubber material or the like is attached to the circular end surface 89B.

  The piston 89 is formed with a through-hole 89C having a long cross-sectional rectangular shape along the longitudinal direction thereof, and both side surfaces thereof are communicated with each other. Further, a gas vent hole communicating with the through hole 89 </ b> C from the pressure receiving side surface for receiving the gas of the seal plate 97 is formed in the piston 89 and the seal plate 97. Before the pretensioner unit 7 operates, that is, in a normal standby state in which no gas is generated by the gas generating member 87, the piston 89 is moved to a position where the rack 89A is in non-engagement with the pinion gear teeth 71A. It is inserted and arranged on the back side of the piston guide cylinder portion 88A.

  The pinion gear 71 is a columnar member made of steel or the like, and pinion gear teeth 71A that can mesh with the rack 89A are formed on the outer periphery thereof. Further, a columnar support portion 71B extending from the pinion gear teeth 71A toward the cover plate 95 is formed. The support portion 71B is rotatably fitted in a support hole 98 formed in a cover plate 95 attached to the side wall portion 13.

  In a state where the support portion 71B is rotatably fitted in the support hole 98, a part of the pinion gear teeth 71A is disposed in the opening 92 of the piston guide cylinder portion 88A. When the piston 89 moves from the normal standby state to the tip end side of the piston guide cylinder portion 88A, the rack 89A meshes with the pinion gear teeth 71A, and the pinion gear 71 rotates in the webbing take-up direction.

  The rotation of the pinion gear 71 is transmitted to the take-up drum 65 through the clutch mechanism 91. That is, a cylindrical boss portion 71D protruding along the axial direction is formed at the end portion of the pinion gear 71 on the side wall portion 13 side in the axial direction. On the outer peripheral surface of the boss portion 71D, a spline composed of six protrusions having the outer diameter of the base end portion is formed. The boss portion 71D is rotatably fitted in a through hole 99 formed in the base plate 93, and protrudes from the winding drum 65 side.

  Further, the clutch mechanism 91 rotates the pinion gear 71 from the state in which the winding drum 65 freely rotates with respect to the pinion gear 71 in a normal state (the state in which the clutch pawl 102 is accommodated) when the pretensioner unit 7 is operated. It is configured to be able to be switched to a state where it is transmitted to the winding drum 65 (a state where the clutch pawl 102 protrudes).

  The clutch mechanism 91 is formed of a pawl base 101 made of steel or the like, four clutch pawls 102 made of steel or the like, and a synthetic resin such as polyacetal, on the base plate 93 side of the pawl base 101. A substantially annular pawl guide 103 to be abutted, and a synthetic resin such as polyacetal, which is abutted against the winding drum 65 side of the pawl base 101, together with the pawl guide 103, the pawl base 101 and each clutch pawl. It is comprised from the substantially annular bearing 73 which clamps 102.

  A fitting hole 104 in which six spline grooves are formed so that the boss 71D of the pinion gear 71 is fitted is provided at the center of the pawl base 101. The boss portion 71D of the pinion gear 71 is press-fitted into the fitting hole 104 of the pawl base 101 with the base plate 93 and the pawl guide 103 interposed therebetween, so that the pawl base 101 is attached to the pinion gear 71 so as not to rotate relative to the pinion gear 71. . That is, the pawl base 101 and the pinion gear 71 are configured to rotate integrally.

  The bearing 73 is configured to be locked to the outer peripheral portion of the pawl guide 103 by a plurality of elastic locking pieces 73A protruding from the outer peripheral portion to the pawl guide 103 side. Further, a through hole 73 </ b> B having an inner diameter substantially equal to the outer diameter of the boss 72 of the winding drum 65 is formed in the center portion of the bearing 73. Furthermore, a cylindrical bearing portion 73C having the same inner diameter as the through hole 73B and an outer diameter substantially equal to the inner diameter of the boss portion 71D of the pinion gear 71 is continuous from the peripheral portion on the pawl base 101 side of the through hole 73B. It is erected so as to protrude.

  When the boss portion 71D of the pinion gear 71 is press-fitted into the fitting hole 104 of the pawl base 101, the cylindrical bearing portion 73C standing at the center of the bearing 73 is fitted into the boss portion 71D. . Further, a boss 72 erected at the center position of the end surface portion of the winding drum 65 on the pretensioner unit 7 side is rotatably fitted into the bearing 73. Each clutch pawl 102 is supported on the pawl base 101 in an accommodation posture. The accommodated posture is a posture in which each clutch pawl 102 is accommodated within the outer peripheral edge of the pawl base 101.

  The pawl guide 103 is a substantially annular member, and is disposed at a position facing the pawl base 101 and each clutch pawl 102. Four positioning protrusions (not shown) protrude from the side surface of the pawl guide 103 on the base plate 93 side, and the positioning protrusions are fitted into the positioning holes 93A of the base plate 93. The pawl guide 103 is attached and fixed to the base plate 93 in a non-rotatable state.

  Further, on the surface of the pawl guide 103 on the side of the pawl base 101, each posture changing projection 103 </ b> A protrudes corresponding to each clutch pawl 102. Then, when the pawl base 101 and the pawl guide 103 rotate relative to each other by the operation of the pretensioner unit 7, the clutch pawls 102 abut against the attitude changing projections 103A, respectively, and the attitude is changed from the accommodated attitude to the locked attitude. It is like that. The locking posture is a posture in which the tip end portion of the clutch pawl 102 protrudes outward from the outer peripheral edge portion of the pawl base 101.

  Further, when each clutch pawl 102 changes its position to the locked position, it engages with the winding drum 65. Specifically, the clutch mechanism 91 is fitted into the boss 72 of the take-up drum 65 via the bearing 73 and rotatably supports the take-up drum 65, and each clutch pawl 102 is an outer peripheral edge of the pawl base 101. When projecting outward, the inner gear 69 formed on the inner peripheral surface of the flange 68 can be engaged.

  Then, when each clutch pawl 102 is changed to the locked posture, the front end portion of each clutch pawl 102 is engaged with the internal gear 69, whereby the pawl base 101 rotates the winding drum 65. The engagement between the clutch pawl 102 and the internal gear 69 is an engagement structure in only one direction that rotates the winding drum 65 in the winding direction of the webbing 3.

  Further, once engaged, the clutch pawls 102 are engaged with the internal gear 69 with deformation, and when the take-up drum 65 rotates in the webbing pull-out direction after the engagement, the pinion gear 71 is moved by the pretensioner unit 7. The piston 89 is rotated back through the clutch mechanism 91 in the direction opposite to the direction of operation, and the piston 89 is pushed back in the direction opposite to the operation direction. When the piston 89 is pushed back to a position where the engagement between the rack 89 A of the piston 89 and the pinion gear teeth 71 A of the pinion gear 71 is disengaged, the pinion gear 71 is disengaged from the piston 89, so that the winding drum 65 rotates freely with respect to the piston 89. become able to.

[Schematic configuration of winding spring unit]
Next, a schematic configuration of the winding spring unit 8 will be described with reference to FIGS. 2, 3, 8 to 10, and 13.
8 and 9 are exploded perspective views of the winding spring unit 8 and the lock unit 9 including the ratchet gear. FIG. 10 is a sectional view for explaining the attachment of the spring case 107. FIG. 13 is an enlarged cross-sectional view of a main part including the winding spring unit 8 and the lock unit 9 of FIG.

  As shown in FIGS. 2, 3, 8, 9, and 13, the winding spring unit 8 includes a spiral spring 105 and an outer end 105 </ b> A of the spiral spring 105 that is erected from the bottom surface of the inner peripheral edge. A spring case 107 that is fixed to the rib 106 and accommodates the spiral spring 105, and a spring shaft 108 to which the inner end 105B of the spiral spring 105 is connected and the spring force is urged. The spring case 107 is formed with a groove portion 107A having a predetermined depth (for example, a depth of about 2.5 mm) on the end edge portion on the mechanism cover 111 side constituting the lock unit 9 over almost the entire circumference. ing.

  Further, at the edge of the spring case 107 on the mechanism cover 111 side, plate-like locking pieces 8A having a substantially rectangular shape in front view from three locations on the outer peripheral portion are formed in through holes formed in a substantially central portion of the mechanism cover 111. A central shaft 113 </ b> A of the 113 protrudes concentrically. In addition, the outer peripheral surface on the radially outer side with respect to the central axis 113A of the through hole 113 of each locking piece 8A is formed so as to be located on a concentric circle.

  As shown in FIGS. 8 and 9, the locking piece 8 </ b> A located at the lower end edge of the spring case 107 is continuous with the end edge on the counterclockwise side with respect to the central axis 113 </ b> A of the through hole 113. A fixed portion 8B having a square cross section is provided continuously. In addition, a through hole 8C parallel to the central axis 113A of the through hole 113 is formed at a substantially central part of the fixing part 8B, and the end of the through hole 8C on the outer side in the direction of the central axis 113A is fixed. The pin 8D is integrally formed.

  Further, the shaft diameter of the fixing pin 8D is formed to be substantially the same as the inner diameter of the through hole 8C, and the fixing pin 8D can be pushed into the through hole 8C by pushing the fixing pin 8D toward the mechanism cover 111 with a predetermined load or more. Further, the length of the fixing pin 8D is formed so as to be longer than the thickness of the fixing portion 8B.

  On the other hand, as shown in FIGS. 8 to 10, the mechanism cover 111 has a thick plate-like holding portion 112 having a substantially rectangular cross section from three locations facing the respective locking pieces 8 </ b> A on the outer peripheral portion. Projected on the side. In addition, at the base end portion of each holding portion 112, there is a fitting groove portion 112A having a substantially rectangular cross section that is notched in a counterclockwise direction with respect to the central axis 113A of the through hole 113 and whose rear end portion is closed. Is formed.

  In addition, the bottom surface portion on the radially outer side with respect to the central axis 113A of the through hole 113 of each fitting groove portion 112A has a slightly larger radius (for example, about The radius is larger by 0.2 mm to 0.5 mm.). In addition, the width dimension of each fitting groove 112A in the direction of the central axis 113A is formed to be approximately the same as the thickness dimension of each locking piece 8A. As will be described later, each locking piece 8A has each fitting groove 112A. It is comprised so that it may fit in (refer FIG. 10).

  Further, the mechanism cover 111 is provided with a substantially ring-shaped rib portion 111 </ b> A that is erected at a predetermined height (for example, about 2 mm in height) along the outer peripheral edge portion of the winding drum unit 6 in the rotation axis direction. It has been. The rib portion 111A is provided at a position corresponding to the groove portion 107A, and the inner diameter and the outer diameter of the rib portion 111A are in a state in which the rib portion 111A is fitted in the groove portion 107A with respect to the inner diameter and the outer diameter of the groove portion 107A. Each is provided so as to form a predetermined gap (for example, a gap of about 0.1 mm to 0.3 mm).

  Further, as shown in FIGS. 8 and 9, the spring case 107 is attached to the mechanism cover in the vicinity of the central axis 113A of the holding portion 112 facing the lower end edge of the rib portion 111A in the clockwise direction as will be described later. A fixing hole 114 having a circular cross section is formed at a position facing the fixing pin 8D when attached to 111.

  The inner diameter of the fixing hole 114 is formed to be smaller than the outer diameter of the fixing pin 8D of the spring case 107 by a predetermined dimension (for example, about 0.1 mm to 0.3 mm), and the fixing pin 8D is press-fitted. It is provided so that it can. Further, a cylindrical boss 115 whose rear side is closed is erected on the rear side of the fixing hole 114, that is, on the peripheral edge portion on the side wall 12 side of the housing 11. Further, the inner diameter of the cylindrical boss 115 is formed in a circular cross section having the same diameter as that of the fixing hole 114, and is formed coaxially with the fixing hole 114.

Here, an attachment method for attaching the take-up spring unit 8 to the mechanism cover 111 will be described.
As shown in FIG. 9, first, the outer end 105 </ b> A of the spiral spring 105 is fitted into the rib 106 erected on the inner side of the spring case 107, housed in the spring case 107, and the spring is connected to the inner end 105 </ b> B of the spiral spring 105. The mounting groove 108C of the shaft 108 is fitted. Further, as shown in FIGS. 8 and 9, the spring shaft 108 has a pin 109 erected at a substantially central position of the bottom surface portion 107 </ b> B of the spring case 107 and is inserted into the through hole 108 </ b> A of the bottom surface portion, and the bottom surface portion side is The pin 109 is rotatably abutted on the peripheral edge portion.

  Then, as shown in FIG. 8, each locking piece 8 </ b> A projecting radially outward from three locations on the outer peripheral portion of the spring case 107 is connected to the edge portion on the front-view clockwise direction of the holding portion 112 of the mechanism cover 111. Position it so as to face. As shown in FIGS. 8 and 13, the distal end portion 133 </ b> A of the rotating shaft portion 133 of the locking gear 121 protruding from the through hole 113 of the mechanism cover 111 is formed in a rectangular cross section, and along the central axis. A shaft hole 133B into which the pin 109 is inserted is formed.

  Subsequently, as shown in FIGS. 9 and 13, the tip end portion 133 </ b> A of the rotating shaft portion 133 of the locking gear 121 protruding from the through hole 113 of the mechanism cover 111 is formed in a cylindrical hole formed in a rectangular cross section of the spring shaft 108. The rotating shaft part 133 of the locking gear 121 is connected to the spring shaft 108 so as not to be relatively rotatable. At the same time, as shown in FIG. 10, the rib portion 111 </ b> A standing on the peripheral edge portion of the mechanism cover 111 is fitted into the groove portion 107 </ b> A of the spring case 107.

  Then, as shown in FIG. 10, the spring case 107 is rotated in the webbing pull-out direction, that is, counterclockwise when viewed from the front (in the direction of arrow 110 in FIG. 10), and each locking piece 8A of the spring case 107 is moved to the mechanism. The cover 111 is fitted into the fitting groove 112A of each holding part 112 and is brought into contact with the back side of each fitting groove 112A. Accordingly, the spring case 107 is positioned so as not to move in the radial direction and the axial direction with respect to the central axis 113A of the through hole 113 of the mechanism cover 111.

  Thereafter, in this state, the fixing pin 8D of the spring case 107 is pressed and press-fitted into the through hole 8C of the fixing portion 8B and the fixing hole 114 of the mechanism cover 111, so that the take-up spring unit 8 enters the mechanism cover 111. On the other hand, the winding spring unit 8 is fixed in a relatively non-rotatable manner, and is attached in a state in which the winding spring unit 8 is in contact with the outer side in the rotation axis direction of the winding drum unit 6 of the mechanism cover 111.

  As a result, the rib portion 111A erected on the peripheral edge portion of the mechanism cover 111 is fitted into the groove portion 107A of the spring case 107, and entry of dust, dust, or the like into the spring case 107 is prevented. In addition, as shown in FIG. 13, the end portion of the spring shaft 108 on the lock unit 9 side in a state where the bottom surface portion side of the mechanism cover 111 in the spring shaft 108 is rotatably contacted with the peripheral portion of the pin 109; A predetermined gap (for example, a gap of about 0.3 mm) is formed between the peripheral edge of the through hole 113 formed in the substantially central portion of the mechanism cover 111.

  At the same time, a predetermined gap (for example, a gap of about 0.3 mm) is also formed between the bottom surface of the cylindrical hole 108 </ b> B of the spring shaft 108 and the distal end portion 133 </ b> A of the rotating shaft 133 of the locking gear 121. Yes. Therefore, the spring shaft 108 is provided between the spring case 107 and the mechanism cover 111 so as to be movable in the axial direction of the central shaft 113A by a predetermined gap.

[Schematic configuration of lock unit]
Next, a schematic configuration of the lock unit 9 constituting the lock mechanism 10 that stops the pull-out of the webbing 3 in response to a sudden pull-out of the webbing 3 or a rapid acceleration of the vehicle will be described with reference to FIGS. This will be described with reference to FIG.

  As shown in FIGS. 8, 9, 12, and 13, the lock unit 9 includes a mechanism cover 111, a locking gear 121, a lock arm 122, a sensor spring 123, a clutch 125, and a pilot lever 126. In the first embodiment, among the members constituting the lock unit 9, the members excluding the sensor spring 123 are formed of synthetic resin, and the friction coefficient between the members when they are in contact with each other is small. It is.

  As shown in FIGS. 8, 9, 11 to 13, the mechanism cover 111 is formed with a substantially box-shaped mechanism housing portion 127 having a substantially circular bottom surface portion 118 opened on the side wall 12 side of the housing 11. The locking gear 121 and the clutch 125 are accommodated. As shown in FIG. 11, the bottom surface portion 118 of the mechanism cover 111 is formed to have a substantially uniform thickness, and the peripheral edge portion of the through hole 113 is larger than the outer peripheral portion of the bottom surface portion 118. Is bent to a predetermined depth L1 (for example, L1 = 0.5 mm to 1 mm) inward in the direction of the rotation axis of the winding drum unit 6 and is formed so as to be elastically deformable outward in the direction of the rotation axis of the winding drum unit 6.

  Further, the mechanism cover 111 is formed in a concave shape having a substantially rectangular cross section at a corner portion (lower left corner portion in FIG. 9) facing the vehicle acceleration sensor 28 attached to the housing 11 via the sensor cover 27. The sensor housing portion 128 is provided so as to be continuous with the mechanism housing portion 127.

  When the mechanism cover 111 is attached to the side wall portion 12 by the ny latches 9A and the locking hooks 9B, the sensor holder 51 of the vehicle acceleration sensor 28 is fitted into the sensor housing portion 128, and the sensor lever 53 is moved in the vertical direction. It is configured to be swingable up and down (in the vertical direction in FIG. 9). In addition, the mechanism housing part 127 and the sensor housing part 128 are opened so as to communicate with a substantially central part at the lower end part of the mechanism housing part 127 of the mechanism cover 111 (which is a substantially central part at the lower end part in FIG. 9). Opened portion 129 is formed.

  The opening 129 is formed so that the front end of the lock claw 53A projecting upward from the front edge of the sensor lever 53 of the vehicle acceleration sensor 28 (upward in FIG. 9) is vertically up and down ( In FIG. 9, the front end of the lock claw 53 </ b> A is positioned in the vicinity of the receiving plate portion 162 of the pilot lever 126 (see FIG. 12). When the inertial mass body 52 is moved by the acceleration exceeding the predetermined value and the sensor lever 53 is rotated upward in the vertical direction, the lock pawl 53A is received by the receiving plate portion 162 of the pilot lever 126 through the opening 129. The pilot lever 126 is configured to rotate upward in the vertical direction.

  Further, a cylindrical support boss 131 is erected on the substantially circular bottom surface portion 118 of the mechanism accommodating portion 127 from the peripheral edge portion of the through hole 113 formed in the center portion. The outer periphery of the tip end portion of the support boss 131 on the locking gear 121 side is formed with a tapered chamfered portion 131A that is inclined at a predetermined angle (for example, an inclination angle of about 30 °) toward the tip end over the entire circumference. ing. The support boss 131 is fitted with a cylindrical rotating shaft portion 133 protruding from the back side facing the mechanism cover 111 at the center of the disc-shaped bottom surface portion 132 of the locking gear 121 for sliding rotation. Supported as possible.

  The locking gear 121 is erected in an annular shape from the entire circumference of the disc-shaped bottom surface portion 132 toward the clutch 125, and locking gear teeth 121 </ b> A that engage with the pilot lever 126 are formed on the outer peripheral portion. This locking gear tooth 121A is formed to engage with the engaging claw portion 126A of the pilot lever 126 only when the locking gear 121 rotates in the webbing pull-out direction.

  Further, as shown in FIGS. 8, 9, 12, and 13, a shaft portion erected on the center portion of the end surface of the ratchet gear 35 on the side of the locking gear 121 is provided at the center portion of the bottom surface portion 132 of the locking gear 121. A through-hole into which 116 is inserted is formed. A cylindrical base portion 134 is erected from the peripheral portion of the through hole on the mechanism cover 111 side at substantially the same height as the axial height of the locking gear teeth 121A. The cylindrical rotation shaft portion 133 of the locking gear 121 is smaller than the base portion 134 from the edge of the cylindrical base portion 134 on the side of the mechanism cover 111 and is substantially within the inner diameter of the support boss 131. The same outer diameter extends coaxially toward the mechanism cover 111 side. Further, the end of the rotary shaft 133 on the side of the mechanism cover 111 is closed, and a distal end portion 133A having a rectangular cross section extends coaxially.

  Therefore, inside the base portion 134 and the rotation shaft portion 133, the shaft portion 116 that opens to the end surface on the ratchet gear 35 side of the locking gear 121 and is erected on the center portion of the end surface on the mechanism cover 111 side of the ratchet gear 35. A shaft hole part 134A having a circular cross section is formed. Further, a plurality of ribs 134B are erected on the inner peripheral surface of the shaft hole portion 134A at the same height in the radial direction along the axial direction so as to contact the outer peripheral surface of the shaft portion 116 of the ratchet gear 35. Is provided. In addition, about half of the total length of the shaft portion 116 on the base end side is formed in a truncated cone, and about half of the distal end side is formed in a cylindrical shape that is continuous with the truncated cone.

  Further, around the base end portion of the rotating shaft portion 133, an annular rib 135 is erected coaxially at a height substantially equal to the thickness dimension of the substantially disc-shaped plate portion 151 of the clutch 125, An insertion groove 135A is formed. The inner peripheral wall portion of the annular rib 135 is inclined radially outward at an angle equal to or greater than the inclination angle of the tip end portion of the support boss 131 (for example, an inclination angle of about 45 °). Further, the outer diameter of the bottom surface portion of the insertion groove 135 </ b> A formed inside the annular rib 135 is formed to be substantially the same as the outer diameter of the tip portion of the support boss 131.

  Further, the outer diameter of the annular rib 135 is formed to be substantially the same as the inner diameter of the through hole 152 formed in the central portion of the plate portion 151 of the clutch 125 and is smaller than the outer diameter of the base portion 134. It is formed in the diameter. In addition, an annular rib 152A is erected at a predetermined height (for example, a height of about 0.5 mm) at the edge of the through hole 152 of the clutch 125 on the side of the locking gear 121. Has been.

  As a result, the annular rib 135 of the locking gear 121 is fitted into the through hole 152 of the clutch 125, and the annular rib 152 </ b> A is brought into contact with the outer peripheral side base end portion of the rib 135. The back surface of the locking gear 121 is inserted into the support boss 131 of the mechanism cover 111 and the tip of the support boss 131 is brought into contact with the bottom surface of the insertion groove 135A formed on the radially inner side of the annular rib 135. A rotating shaft portion 133 protruding from the side is coaxially attached to and supported by the support boss 131 over almost the entire height. An annular rib 135 of the locking gear 121 is fitted into the through hole 152 so as to be slidable and rotatable, and the clutch 125 is accommodated between the locking gear 121 and the mechanism cover 111 so as to be rotatable within a certain rotation range. The

  Further, as shown in FIGS. 8, 9 and 13, on the end face of the locking gear 121 on the ratchet gear 35 side, there are four protrusions 136 projecting into a substantially rectangular cylindrical shape whose cross section is long in the circumferential direction. Are arranged so as to be located on concentric circles at a predetermined distance (for example, a distance of about 14 mm) outwardly in the radial direction from the rotating shaft 121B at equal center angles. In addition, as for the one convex part 136, the peripheral part of the radial direction outer side is partly notched. In addition, a positioning hole having a predetermined inner diameter (for example, an inner diameter of about 3.5 mm) is formed in the bottom surface portion 132 of the locking gear 121 at a substantially central position between a pair of convex portions 136 adjacent in the circumferential direction. 137 is formed.

  Further, on the end surface portion of the ratchet gear 35 facing the locking gear 121, there are four through holes 138 having substantially the same shape as the convex portion 136 of the locking gear 121 and having a substantially rectangular cross section in the circumferential direction at equal central angles. , Formed at a position facing each convex portion 136 separated from the rotary shaft 121B by a predetermined distance (for example, a distance of about 14 mm) radially outward.

  Further, the end face portion of the ratchet gear 35 that faces the locking gear 121 is located between the pair of circumferentially adjacent through holes 138 at a position facing the positioning hole 137 and the inner diameter of the positioning hole 137. A positioning pin 139 formed with substantially the same outer diameter is provided upright. Further, the height of the shaft portion 116 erected on the outer end surface of the ratchet gear 35 in the rotation axis direction is formed to be substantially equal to the depth of the shaft hole portion 134 </ b> A of the locking gear 121. Further, the depth of the shaft hole portion 134 </ b> A of the locking gear 121 is formed such that the tip end of the shaft portion 116 is located on the inner side in the rotation axis direction than the tip end of the tip end portion 133 </ b> A of the rotation shaft portion 133.

  Accordingly, the shaft portion 116 of the ratchet gear 35 is fitted into the shaft hole portion 134A of the locking gear 121, and the positioning pin 139 of the ratchet gear 35 is fitted into the positioning hole 137 of the locking gear 121. The convex portion 136 is fitted into each through hole 138 of the ratchet gear 35. As a result, the locking gear 121 is coaxially attached to the ratchet gear 35 so as to be relatively non-rotatable with the locking gear 121 in contact with the end surface of the ratchet gear 35 on the rotational axis direction. 116 is positioned and supported in the support boss 131 of the mechanism cover 111 via the rotating shaft portion 133 of the locking gear 121.

  Further, the ratchet gear 35 of the winding drum unit 6 is attached coaxially to the spring shaft 108 of the winding spring unit 8 through the distal end portion 133A of the rotating shaft portion 133 of the locking gear 121 so as not to be relatively rotatable. Accordingly, the winding drum unit 6 is always urged to rotate in the webbing winding direction via the winding spring unit 8.

  Further, as shown in FIGS. 8, 9, 12, and 13, a columnar support boss 141 adjacent to the base portion 134 is provided on the surface of the bottom surface portion 132 of the locking gear 121 on the clutch 125 side. It is erected at a height lower than the locking gear teeth 121A. The lock arm 122 made of synthetic resin formed in a substantially arcuate shape so as to surround the base portion 134 is inserted into the through-hole 142 formed in the end edge portion on the base portion 134 side in the substantially central portion in the longitudinal direction. The support boss 141 is rotatably inserted and pivotally supported.

  In addition, an elastic locking piece 143 having an inverted L-shaped cross section is erected on the mechanism cover 111 side at a position near the outer side in the radial direction with respect to the support boss 141 on the bottom surface portion 132 of the locking gear 121. The elastic locking piece 143 is inserted into a window portion 144 having a substantially step shape formed on the side of the through hole 142 of the lock arm 122 and having a stepped portion, and is elastic so as to be rotatable around the axis of the base portion 134. Is locked.

  Further, as shown in FIG. 12, the locking gear 121 includes a spring support pin 145 in which one end side of the sensor spring 123 is fitted into a rib portion extending radially outward from the outer peripheral surface of the base portion 134. The webbing is pulled out in the direction perpendicular to the axis of the base part 134. In addition, a spring support pin 146 on which the other end side of the sensor spring 123 is fitted is erected on the side wall of the lock arm 122 facing the spring support pin 145.

  Therefore, as shown in FIGS. 9 and 12, the lock arm 122 is fitted to the spring support pins 145 and 146 at both ends of the sensor spring 123 so that the lock arm 122 is in the webbing pull-out direction side with respect to the axis of the support boss 141 (see FIG. 12 is counterclockwise) and is biased with a predetermined load. The lock arm 122 has a stopper 154 formed so that an end edge portion on the engagement claw 149 side that engages with the clutch gear 148 of the clutch 125 protrudes radially outward from the base portion 134 of the locking gear 121. It is in contact with.

  On the other hand, as described later, when the lock arm 122 is rotated in the webbing winding direction (clockwise in FIG. 12) against the urging force of the sensor spring 123 and engaged with the clutch gear 148, The edge of the engagement claw 149 opposite to the engagement portion is a predetermined clearance (for example, a clearance of about 0.3 mm) from the spindle-shaped detent 155 that is erected on the bottom surface portion 132 of the locking gear 121. ).

  Further, as shown in FIGS. 8, 9, 12 and 13, the clutch 125 is rotatable between the locking mechanism 121 and the mechanism cover 111 within a certain rotation range while being sandwiched between the locking gear 121 and the mechanism cover 111. Be contained. On the locking gear 121 side of the clutch 125, an outer diameter slightly smaller than the inner peripheral diameter of the annular rib formed on the outer peripheral portion of the locking gear 121 is coaxial with the through hole 152. An annular rib portion 153 is provided upright.

  On the inner peripheral surface of the rib portion 153, a clutch gear 148 that engages with the engaging claws 149 of the lock arm 122 is formed. The clutch gear 148 is formed so as to engage with the engaging claw 149 of the lock arm 122 only when the locking gear 121 rotates in the webbing pull-out direction with respect to the axis of the through hole 152.

  An annular outer rib portion 157 is erected on the outer peripheral portion of the substantially disc-shaped plate portion 151 of the clutch 125 so as to surround the rib portion 153. Further, the edge portion of the outer rib portion 157 on the ratchet gear 35 side is extended outward in the radial direction with respect to the central axis of the through-hole 152 and is extended so as to be slightly inclined toward the ratchet gear 35 side. The flange portion 158 is formed over the entire circumference.

  Further, the corner of the outer rib portion 157 facing the pawl 23 (the lower left corner portion in FIG. 8) is vertically downward (downward in FIG. 8) from the outer peripheral surface of the outer rib portion 157. A guide block portion 159 extending to) is provided. The guide block portion 159 has a substantially elongated guide hole 156 in which a guide pin 42 erected on the side surface of the tip portion including the engaging teeth 23A and 23B of the pawl 23 is loosely fitted from the ratchet gear 35 side. Is formed.

  As shown in FIG. 12, the guide hole 156 is formed in a long groove shape substantially parallel to the webbing pull-out direction (vertical direction in FIG. 12) at the corner of the clutch 125 facing the pawl 23. . As a result, when the clutch 125 is rotated in the webbing pull-out direction (counterclockwise in FIG. 12), the guide pin 42 is moved along the guide hole 156, and each engagement tooth of the pawl 23 is moved. 23A and 23B are rotated so as to approach the ratchet gear portion 35A of the ratchet gear 35.

  Further, the pawl 23 is urged to rotate away from the ratchet gear 35 by the torsion coil spring 26, and the clutch 125 is urged by the guide pin 42 of the pawl 23 that is loosely fitted in the guide hole 156. . Due to this urging force, the clutch 125 is the end edge portion at the position farthest away from the ratchet gear 35 in the rotational radius direction of the clutch 125 in the guide hole 156 (the lower end edge portion of the guide hole 156 in FIG. 12). ) Is biased so as to be in a rotational posture in a state where the guide pin 42 of the pawl 23 abuts, so that the webbing is pulled out in a direction opposite to the drawing direction. Therefore, the clutch urging mechanism 169 is configured by the pawl 23 and the torsion coil spring 26.

  At the same time, the pawl 23 is normally an end edge portion at a position farthest away from the ratchet gear 35 in the radial direction of the clutch 125 in the guide hole 156 (the lower end edge portion of the guide hole 156 in FIG. 12). ), The guide pin 42 of the pawl 23 abuts and the rotation is restricted, so that it is held so as to be located in the vicinity of the back side of the notch 38 formed in the side wall 12.

  Further, the lower end edge portion (in FIG. 9, the lower end edge portion) of the outer rib portion 157 of the clutch 125 is located above the sensor housing portion 128 from the end surface portion on the ratchet gear 35 side of the guide block portion 159 (in FIG. 9). The plate-like extension part 160 extended from the flange part 158 to the outer side in the radial direction in a substantially arc shape is formed up to a part facing the upper side. As shown in FIGS. 8, 9, and 12, the cylindrical shaft portion 161 of the pilot lever 126 is positioned in the vicinity of the end edge portion on the opposite side to the guide block portion 159 of the extension portion 160. A thin cylindrical mounting boss 163 to be inserted is erected on the mechanism cover 111 side at substantially the same height as the height of the outer rib portion 157.

  Here, as shown in FIGS. 8, 9, and 12, the pilot lever 126 includes a cylindrical shaft portion 161, a plate-like engagement claw portion 126A, a thin plate-like receiving plate portion 162, and a thin plate-like shape. Connecting plate portion 164. The axial length of the shaft portion 161 is formed to be approximately the same as the height of the mounting boss 163 provided upright on the extension portion 160. Further, the plate-like engagement claw 126A is formed in a substantially L shape when viewed from the rotational axis direction, with its tip portion bent obliquely toward the locking gear 121 side. In addition, the plate-like engagement claw portion 126A extends from the outer peripheral surface of the shaft portion 161 so as to be substantially horizontal when the pilot lever 126 is rotated by its own weight and restricted in the downward vertical direction. A predetermined length projecting toward the guide hole 156 with a width shorter than the length of the shaft portion 161 is provided.

  Further, the thin plate-like receiving plate portion 162 is projected from the outer peripheral surface of the shaft portion 161 to the tangential guide hole 156 side so as to face the engaging claw portion 126A, and the distal end portion is the distal end side of the engaging claw portion 126A. It is bent at an angle so that it is almost parallel to. Further, the thin plate-like connecting plate portion 164 is formed so as to connect the engaging claw portion 126 </ b> A and the front end portion of the receiving plate portion 162. Further, in the vicinity of the base end portion of the engaging claw portion 126A, an upward detent portion 165 that restricts the rotation of the pilot lever 126 in the locking gear 121 side direction, that is, the upward rotation in the vertical direction, is a shaft portion. The outer peripheral surface 161 protrudes radially outward. Further, the upward detent portion 165 has a predetermined height (for example, a height) that is substantially the same width as the width of the engagement claw portion 126A and is substantially perpendicular to the base end portion of the engagement claw portion 126A. It is about 1.5 mm.) Projected.

  Further, on the opposite side of the shaft portion 161 to the receiving plate portion 162 in the tangential direction, a downward detent portion that restricts the rotation of the pilot lever 126 in the sensor lever 53 side direction, that is, the downward rotation in the vertical direction. 166 protrudes radially outward from the outer peripheral surface of the shaft portion 161. Further, the downward detent portion 166 has a width dimension in the rotation axis direction that is narrower than the width in the rotation axis direction of the receiving plate portion 162 from the end surface side opposite to the ratchet gear 35 of the shaft portion 161. A predetermined height (for example, a height of about 1.5 mm) is provided so as to face the base end portion of the portion 162.

  Also, as shown in FIG. 12, a pilot lever support block 171 is provided at the end of the extension portion 160 facing the mounting boss 163 so as to protrude toward the mechanism cover 111 at substantially the same height as the outer rib portion 157. ing. The inner surface of the pilot lever support block 171 facing the mounting boss 163 is coaxial with the mounting boss 163 and is slightly larger than the radius of the outer peripheral surface of the shaft 161 of the pilot lever 126 (for example, about 0.1 mm). It is formed in a smooth curved surface having a substantially semicircular shape when viewed from the front with a radius of curvature.

  Also, as shown in FIG. 12, an opening 172 penetrating vertically in the vertical direction at a position facing the engaging claw 126A of the pilot lever 126 of the outer rib portion 157 has a predetermined width in the circumferential direction and a plate portion 151. It is formed by cutting out a predetermined dimension to the inner side of the edge portion. The opening 172 is formed to be able to enter the opening 172 and engage with the locking gear teeth 121A when the engaging claw 126A is pressed and rotated by the lock claw 53A of the sensor lever 53. Yes.

  As shown in FIG. 12, when the pilot lever 126 is rotated downward in the vertical direction (downward in FIG. 12) due to its own weight, the downward detent 166 has a pilot lever support block. The rotation angle to the lower side in the vertical direction (the downward direction in FIG. 12) is restricted by abutting 171. Further, in normal times, a gap is formed between the receiving plate portion 162 of the pilot lever 126 and the lock claw 53A of the sensor lever 53.

  When the sensor lever 53 is turned upward in the vertical direction (upward in FIG. 12) and the pilot lever 126 is turned upward in the vertical direction by the lock claw 53A, the pilot lever 126 The engaging claw portion 126A comes into contact with the locking gear 121 and engages with the locking gear tooth 121A. Further, when the locking gear 121 rotates in the webbing pull-out direction (in the counterclockwise direction in FIG. 12) with the engaging claw 126A of the pilot lever 126 engaged with the locking gear teeth 121A, A load in the mounting boss 163 side direction is applied to the engaging claw portion 126A.

  When the tip portion of the engaging claw 126A that is obliquely bent toward the locking gear 121 due to the load applied to the engaging claw 126A is elastically deformed toward the shaft 161 and further rotated. The upward detent portion 165 of the pilot lever 126 is brought into contact with the pilot lever support block 171. Further, when the mounting boss 163 is bent due to a load applied to the engaging claw portion 126 </ b> A, the outer peripheral surface of the shaft portion 161 comes into contact with the inner surface of the pilot lever support block 171. As a result, the pressing load applied to the engaging claw portion 126A can be supported by the pilot lever support block 171 via the upward detent portion 165 and the shaft portion 161.

Next, a state where the winding spring unit 8 and the lock unit 9 are attached to the side wall portion 12 of the housing 11 will be described with reference to FIGS. 5, 11, and 13.
As shown in FIGS. 5 and 13, the lock unit 9 is formed by the respective nai latches 9 </ b> A and the respective locking hooks 9 </ b> B in a state where the take-up spring unit 8 is attached to the outer side in the rotation axis direction of the take-up drum unit 6 of the mechanism cover 111. It is attached to the outside of the side wall portion 12.

  Further, the shaft portion 116 of the ratchet gear 35 is fitted into the shaft hole portion 134A of the locking gear 121, and the positioning pin 139 of the ratchet gear 35 is fitted into the positioning hole 137 of the locking gear 121. The convex portion 136 is fitted into each through hole 138 of the ratchet gear 35.

  Thus, the locking gear 121 is coaxially attached to the ratchet gear 35 so as not to rotate relative to the ratchet gear 35 in a state where the locking gear 121 is in contact with the outer end surface of the ratchet gear 35 in the rotation axis direction. Further, the rotation shaft portion 133 of the locking gear 121 is fitted into the support boss 131 of the mechanism cover 111 and is rotatably supported in a state where the base end portion of the rotation shaft portion 133 is in contact with the distal end portion of the support boss 131. Has been.

  On the other hand, as shown in FIG. 11, the bottom surface portion 118 of the mechanism cover 111 has a peripheral portion of the through-hole 113 curved at a predetermined depth L1 inward in the rotational axis direction of the take-up drum unit 6 from the outer peripheral portion of the bottom surface portion 118. However, as shown in FIGS. 5 and 13, when the mechanism cover 111 is fixed to the outside of the side wall portion 12, the bottom surface portion 118 of the mechanism cover 111 is a surface substantially parallel to the side wall portion 12. Is forming.

  That is, the bottom surface portion 118 of the mechanism cover 111 is formed in a state in which a surface substantially parallel to the side wall portion 12 is formed when the mechanism cover 111 is fixed to the outside of the side wall portion 12. Is rotatably supported. Therefore, when the mechanism cover 111 is not fixed to the outside of the side wall portion 12, the bottom surface portion 118 of the mechanism cover 111 is formed with the through hole 113 on the basis of a state in which a surface substantially parallel to the side wall portion 12 is formed. The peripheral edge portion of the winding drum unit 6 is formed so as to bend a predetermined depth L1 to the inner side in the rotation axis direction of the winding drum unit 6 than the outer peripheral portion of the bottom surface portion 118.

  As a result, the bottom surface portion 118 of the mechanism cover 111 is pressed by the ratchet gear 35 via the locking gear 121 to the outer side in the rotation axis direction, so that the peripheral edge portion of the through hole 113 is formed on the winding drum unit 6. The ratchet gear 35 is elastically deformed by a distance corresponding to the bending depth L1 outward in the rotation axis direction, and the ratchet gear 35 is pressed and urged inward in the rotation axis direction via the support boss 131 and the locking gear 121.

  Therefore, the force by which the bottom surface portion 118 of the mechanism cover 111 presses and urges the ratchet gear 35 inward in the rotation axis direction via the support boss 131 and the locking gear 121 is such that the peripheral portion of the through hole 113 is in contact with the bottom surface portion 118. It is proportional to the size of the depth L1 that is curved inward in the rotation axis direction of the winding drum unit 6 rather than the outer peripheral portion. Further, the larger the force for pressing and biasing, the stronger the backlash of the winding drum unit 6 can be suppressed.

  As a result, the depth L1 for bending the bottom surface portion 118 of the mechanism cover 111 is such that the rotation resistance of the winding drum unit 6 caused by being pressed and urged inward in the rotation axis direction obstructs the drawing and winding of the webbing 3. As long as there is no backlash, it can be set to any value required to suppress rattling.

  Further, the bottom surface portion 118 of the mechanism cover 111 is elastically deformed outward in the rotation axis direction, and forms a surface substantially parallel to the bottom surface portion 107B of the spring case 107 of the winding spring unit 8. Thereby, a substantially uniform gap is formed between the bottom surface portion 118 of the mechanism cover 111 and the spiral spring 105.

[Operation of locking mechanism]
Next, the operation of the lock mechanism 10 will be described with reference to FIG. In FIG. 12, the webbing 3 is pulled out in the direction of the arrow 173. In FIG. 12, the counterclockwise rotation direction is the rotation direction (webbing pull-out direction) of the winding drum unit 6 when the webbing 3 is pulled out. Further, for the explanation of the operation of the lock mechanism 10, a part of the drawing is cut out and displayed as necessary.

  Here, the lock mechanism 10 is a “webbing sensitive lock mechanism” that operates when the webbing 3 is suddenly pulled out, and a “vehicle body sensitive type” that operates in response to acceleration caused by a vehicle shake or tilt. It operates as two types of lock mechanisms, “lock mechanism”. The operation of the pawl 23 is common to both the “webbing sensitive lock mechanism” and the “vehicle body sensitive lock mechanism”. For this reason, in FIG. 12, about the part which shows the relationship between the pawl 23 and the ratchet gear 35, the part is displayed as a notch state. In addition, the portion showing the relationship between the lock arm 122 and the clutch gear 148 and the portion showing the sensor spring 123 are cut out.

[Description of webbing-sensitive locking mechanism]
First, the locking operation of the “webbing sensitive locking mechanism” will be described with reference to FIG. As shown in FIG. 12, since the lock arm 122 is rotatably supported by the support boss 141 of the locking gear 121, the pull-out acceleration of the webbing 3 is a predetermined acceleration (for example, about 2.0G. 1G≈9.8 m / s 2), the inertia of the lock arm 122 is delayed with respect to the rotation of the locking gear 121 in the webbing pull-out direction.

  For this reason, the lock arm 122 that has been in contact with the stopper 154 rotates clockwise around the support boss 141 with respect to the locking gear 121 in order to maintain the initial position against the biasing force of the sensor spring 123. And rotated to the vicinity of the detent 155. Therefore, the engagement claw 149 of the lock arm 122 is rotated radially outward with respect to the rotation shaft of the locking gear 121 and engaged with the clutch gear 148 of the clutch 125.

  When the webbing 3 is continuously pulled out beyond a predetermined acceleration, the locking gear 121 is further rotated in the webbing pull-out direction (counterclockwise), so that the engagement claw 149 of the lock arm 122 is In the state engaged with the clutch gear 148, the webbing is rotated in the pulling-out direction.

  Accordingly, since the clutch gear 148 is rotated in the webbing pull-out direction by the lock arm 122, the clutch 125 is driven by the guide pin 42 of the pawl 23 that is urged to rotate away from the ratchet gear 35 by the torsion coil spring 26. Against the urging force, it is rotated in the webbing pull-out direction around the axis of the rib 135 of the locking gear 121, that is, around the axis of the rotating shaft 133.

  As a result, when the webbing 3 is further pulled out beyond the predetermined acceleration, the clutch 125 is rotated by the guide pin 42 of the pawl 23 that is urged to rotate away from the ratchet gear 35 by the torsion coil spring 26. It is further rotated in the webbing pull-out direction against the biasing force. Therefore, the guide pin 42 of the pawl 23 is guided by the guide hole 156 of the clutch 125, and the pawl 23 is engaged with the ratchet gear 35 against the urging force of the torsion coil spring 26. Thereby, the rotation of the winding drum unit 6 is locked and the drawer of the webbing 3 is locked.

[Explanation of body-sensitive locking mechanism]
Next, the locking operation of the “body-sensitive locking mechanism” will be described with reference to FIG. As shown in FIG. 12, since the spherical inertia mass body 52 of the vehicle acceleration sensor 28 is placed on the mortar-shaped bottom surface portion of the sensor holder 51, the acceleration due to the shaking or tilting of the vehicle body is a predetermined acceleration ( For example, when it exceeds about 2.0 G.), the bottom surface of the sensor holder 51 is moved to rotate the sensor lever 53 upward in the vertical direction.

  Therefore, the lock claw 53A of the sensor lever 53 comes into contact with the receiving plate portion 162 of the pilot lever 126 that is rotatably attached to the mounting boss 163 provided upright on the extending portion 160 of the clutch 125, and the pilot The lever 126 is rotated upward in the vertical direction. Accordingly, the pilot lever 126 is rotated clockwise around the axis of the mounting boss 163, and the engaging claw 126 A of the pilot lever 126 enters the opening 172 of the clutch 125, and the outer periphery of the locking gear 121. Engage with the locking gear teeth 121A formed in the section. At this time, a predetermined gap (for example, a gap of about 0.1 mm) is formed between the upward detent portion 165 and the pilot lever support block 171.

  When the webbing 3 is pulled out with the pilot lever 126 engaged with the locking gear teeth 121A of the locking gear 121, the locking gear 121 rotates in the webbing pull-out direction (counterclockwise). Is done. The rotation of the locking gear 121 in the webbing pull-out direction is transmitted to the clutch 125 via the pilot lever 126, the mounting boss 163, and the pilot lever support block 171.

  Therefore, as the locking gear 121 rotates in the webbing pull-out direction, the clutch 125 is urged by the guide pin 42 of the pawl 23 that is urged to rotate away from the ratchet gear 35 by the torsion coil spring 26. Against this, it is rotated in the webbing pull-out direction around the axis of the rib 135 of the locking gear 121, that is, around the axis of the rotary shaft 133.

  As a result, when the webbing 3 is further pulled out, the clutch 125 resists the urging force by the guide pin 42 of the pawl 23 that is urged to rotate away from the ratchet gear 35 by the torsion coil spring 26. Then, it is further rotated in the webbing pull-out direction. For this reason, the guide pin 42 of the pawl 23 is guided by the guide hole 156 of the clutch 125, and the engaging teeth 23 </ b> A and 23 </ b> B of the pawl 23 are engaged with the ratchet gear portion 35 </ b> A of the ratchet gear 35. Thereby, the rotation of the winding drum unit 6 is locked and the drawer of the webbing 3 is locked.

  As described above in detail, in the seatbelt retractor 1 according to the first embodiment, the lock unit 9 is attached to the winding spring unit 8 on the outer side in the rotation axis direction of the winding drum unit 6 of the mechanism cover 111. A mechanism cover 111 that houses the locking gear 121, the clutch 125, and the like is attached to the outer side in the rotation axis direction of the winding drum unit 6 on the side wall portion 12. The bottom surface portion 118 of the mechanism cover 111 is elastically deformed outward in the rotational axis direction of the winding drum unit 6 so as to be substantially parallel to the side wall portion 12, and therefore, via the support boss 131 and the locking gear 121, The ratchet gear 35 is pressed and urged inward in the rotation axis direction.

  Thereby, by attaching the mechanism cover 111 to the outer side in the rotation axis direction of the winding drum unit 6 of the side wall portion 12, it is possible to suppress the play in the rotation axis direction of the winding drum unit 6. Further, since the distal end portion of the support boss 131 is brought into contact with the proximal end portion of the rotating shaft portion 133 of the locking gear 121, the peripheral edge portion of the proximal end portion of the support boss 131 can be brought closer to the locking gear 121 side. Further, it is possible to reduce the size of the take-up drum unit 6 of the seat belt retractor 1 in the rotation axis direction.

  Further, when the mechanism cover 111 is attached to the outer side in the rotation axis direction of the winding drum unit 6 on the side wall portion 12, the bottom surface portion 118 is elastically deformed to the outer side in the rotation axis direction of the winding drum unit 6, and the spiral spring 105. Is substantially parallel to the bottom surface portion 107B of the spring case 107.

  As a result, a substantially uniform gap can be formed between the bottom surface portion 118 of the mechanism cover 111 and the spiral spring 105, and the rotational biasing force by the spiral spring 105 can be stabilized. Further, the gap between the bottom surface portion 118 of the mechanism cover 111 and the spiral spring 105 can be minimized, and further downsizing of the winding drum unit 6 of the seat belt retractor 1 can be achieved. .

  Further, the bottom surface portion 118 of the mechanism cover 111 is curved at a predetermined depth L1 so that the base end portion of the support boss 131 is located at the innermost side in the rotation axis direction of the winding drum unit 6 at the bottom surface portion 118. Thereby, when the mechanism cover 111 is attached to the outer side in the rotation axis direction of the winding drum unit 6 on the side wall portion 12 and the shaft portion 116 of the ratchet gear 35 is rotatably supported via the support boss 131 and the locking gear 121. In other words, the bottom surface portion 118 of the mechanism cover 111 can be elastically deformed with almost no bias, and the winding drum unit 6 can be reliably pressed and urged inward in the rotation axis direction.

  In addition, a predetermined gap can be reliably formed between the bottom surface portion 118 of the mechanism cover 111 and the ratchet gear 35, and the winding drum unit 6 can be stably and rotatably supported, and the gap can be minimized. Thus, further downsizing of the take-up drum unit 6 of the seat belt retractor 1 in the rotation axis direction can be achieved.

  Next, the seatbelt retractor 181 according to the second embodiment will be described with reference to FIGS. In the following description, the same reference numerals as those of the seat belt retractor 1 according to the first embodiment shown in FIGS. 1 to 13 are the same as those of the seat belt retractor 1 according to the first embodiment. Or a considerable part is shown.

[Schematic configuration]
First, a schematic configuration of the seatbelt retractor 181 according to the second embodiment will be described with reference to FIGS. 14 to 16. FIG. 14 is an external perspective view of a seatbelt retractor 181 according to the second embodiment. FIG.15 and FIG.16 is the perspective view which decomposed | disassembled the seatbelt retractor 181 for every unit.
As shown in FIGS. 14 to 16, the seat belt retractor 181 is a device for winding up the webbing 3 of the vehicle, and includes a housing unit 182, a winding drum unit 183, a lock unit 185, and a winding spring. And a unit 186.

  The lock unit 185 is mounted on one side wall portion 189 of the housing 188 formed in a substantially U-shape in plan view constituting the housing unit 182 by each ny latch 9A formed integrally with the mechanism cover 187. Fixed to the hole 191. The lock unit 185 constitutes a lock mechanism 10 (see FIG. 12) that stops the pull-out of the webbing 3 in response to a sudden pull-out of the webbing 3 or a rapid acceleration change of the vehicle.

  The take-up spring unit 186 is fixed to each mounting hole 195 formed in the other side wall 193 opposite to the side wall 189 of the housing 188 by each ny latch 9A formed integrally with the spring case 192. Yes. The winding drum unit 183 around which the webbing 3 is wound is rotatable between a lock unit 185 fixed to the side wall 189 of the housing unit 182 and a winding spring unit 186 fixed to the side wall 193. Supported by Further, the winding drum unit 183 is constantly urged in the winding direction of the webbing 3 by a winding spring unit 186 fixed to the outside of the side wall portion 193.

[Schematic configuration of housing unit]
Next, a schematic configuration of the housing unit 182 will be described with reference to FIGS. 15 and 16.
As shown in FIGS. 15 and 16, the housing unit 182 includes a housing 188, a protector 196, a pawl 23, a pawl rivet 25, a torsion coil spring 26, a sensor cover 27, a vehicle acceleration sensor 28, and a connecting member. 32 and 33.

  The housing 188 includes a back plate portion 197 fixed to the vehicle body, and opposite side wall portions 189 and 193 extending from both side edge portions of the back plate portion 197 so that the steel material is substantially U-shaped in plan view. Etc. are formed. The side wall portions 189 and 193 are connected to each other by connecting members 32 and 33 each having a horizontally long thin plate shape that is long in the rotation axis direction of the winding drum unit 183. In addition, an opening is formed in the central portion of the back plate portion 197 so that weight reduction and regulation of the amount of webbing 3 are restricted.

  The side wall 189 is formed with a through-hole 36 into which the ratchet gear 198 of the winding drum unit 183 is inserted while forming a predetermined gap (for example, a gap of about 0.5 mm). The inner peripheral edge portion of the through hole 36 is configured to be recessed to the winding drum unit 183 side by a predetermined depth inward in the central axis direction and to be opposed to the ratchet gear 198 of the winding drum unit 183. Further, the side wall portion 189 has three corners, that is, both corners of an upper end edge portion (upper end edge portion in FIG. 16) and a lower portion of the through hole 36 (downward direction in FIG. 16). Each mounting hole 191 into which each ny latch 9A of the lock unit 185 is fitted and attached is formed.

  Further, a peripheral edge portion that opposes the tip (the other end) side portion including the engaging teeth 23A and 23B of the pawl 23 on the diagonally lower side (the diagonally lower left side in FIG. 16) of the through hole 36. To the outside in the rotational direction of the pawl 23 (the rotational direction is away from the ratchet gear 198 of the pawl 23), and a notch 38 is formed by notching to a depth that accommodates the portion on the tip side. Has been. In addition, the pawl 23 is inserted into the guide hole 156 (see FIG. 18) of the clutch 125 constituting the lock unit 185 at the front end of the side surface on the outer side in the rotation axis direction (the front side in FIG. 16). Guide pins 42 are erected.

  Further, the torsion coil spring 26 is arranged so as to surround the periphery of the head of the pawl rivet 25 with one winding, and the pawl 23 is moved in the direction toward the back side of the notch 38 (see FIG. It is urged to rotate, and the tip side portion including the engaging teeth 23A and 23B is brought into contact with the back side of the notch 38. Accordingly, the pawl 23 is urged to rotate in a direction away from the ratchet gear 198 by the torsion coil spring 26.

  Further, below the through hole 36 in the side wall 189 (in the downward direction in FIG. 16), from the lower side of the central axis of the through hole 36 (in the downward direction in FIG. 16) to the back plate 197 side. A vehicle acceleration sensor 28 is attached to the opening 47 formed in the portion of the vehicle through a sensor cover 27. Further, a bolt insertion hole 63 into which a bolt is inserted when being attached to a fastening piece (not shown) of the vehicle is formed in the lower end portion (the lower end portion in FIG. 15) of the back plate portion 197. .

  Further, a through hole 194 through which the take-up drum unit 183 is inserted is formed in the side wall portion 193 at the center portion. Further, the side wall portion 193 includes both corners of an upper edge portion (upper edge portion in FIG. 15) and a back plate portion of a lower edge portion (lower edge portion in FIG. 15). The mounting holes 195 to which the respective ny latches 9A of the take-up spring unit 186 are fitted and attached are formed at three locations with the corner portion on the 197 side.

  Further, a horizontally long protector 196 attached to the upper edge (in FIG. 15, the upper edge) of the back plate 197 is formed of a synthetic resin such as nylon, and is a plane from which the webbing 3 is drawn. A through hole 196A having a horizontally long rectangular shape is formed. The protector 196 is pushed in contact with the back plate portion 197 so as to be disposed between the opposing side wall portions 189 and 193, thereby forming an engaging projection 196 </ b> B of the protector 196 on the back plate portion 197. It is elastically locked and fixed to the upper edge of the opening.

[Schematic configuration of winding drum unit]
Next, a schematic configuration of the winding drum unit 183 will be described with reference to FIGS. 15, 16, 17, and 23. FIG. FIG. 17 is an exploded perspective view of the winding drum unit 183. FIG. 23 is a cross-sectional view of the seatbelt retractor 181.
As shown in FIG. 17, the winding drum unit 183 includes a winding drum 201, a torsion bar 202, and a ratchet gear 198.

As shown in FIGS. 15, 16, 17, and 23, the winding drum 201 is formed by aluminum die casting, zinc die casting, or the like, and has a substantially cylindrical shape in which the end surface portion on the winding spring unit 186 side is closed. Is formed. In addition, a winding spring side flange 203 having a circular shape when viewed from the front is formed at the end edge of the winding drum 201 on the winding spring unit 186 side in the axial direction. .

  In addition, a base end portion is formed in a circular shape with a predetermined height (for example, a height of about 3 mm) at the center position of the axially outer end face of the take-up spring side flange portion 203, as will be described later. Further, a shaft 205 is erected in such a manner that a portion inserted into the spring shaft 108 is formed in a rectangular shape substantially the same as the distal end portion 133A of the rotating shaft portion 133 of the locking gear 121. Further, a substantially annular rib portion 206 is provided on the outer end surface in the axial direction of the winding spring side flange portion 203 so as to reach the outer side in the axial direction from the side wall portion 193 when the winding drum unit 183 is mounted in the housing 188. So that it is erected on the same axis. Also, an annular outer flange 207 is provided that extends radially outward from the outer peripheral surface of the axially outer edge of the annular rib portion 206 over the entire circumference.

  Further, a shaft hole 201 </ b> A having a draft angle formed so as to be gradually narrowed along the central axis is formed inside the winding drum 201. A spline groove into which a spline 202A formed at one end of a torsion bar 202 made of steel or the like is press-fitted is formed at the end of the shaft hole 201A on the winding spring side flange portion 203 side. .

  The torsion bar 202 includes a shaft portion 202C formed of a steel material and having a circular cross section, and splines 202A and 202B formed at both ends of the shaft portion 202C. Then, by inserting the spline 202A side of the torsion bar 202 into the shaft hole 201A of the take-up drum 201 and press-fitting it into the spline groove, the torsion bar 202 is press-fitted and fixed in the take-up drum 201 so as not to be relatively rotatable.

  Further, the end portion of the winding drum 201 on the lock unit 185 side in the axial direction has a substantially circular lock unit side flange portion extending in a radial direction from the outer peripheral surface slightly inward in the axial direction from the end edge portion. 208 is formed. In addition, a cylindrical step portion 209 having a slightly smaller outer diameter is formed on the outer side in the axial direction from the lock unit side flange portion 208. The step portion 209 is provided so as to surround the spline 202B on the other end side of the torsion bar 202 press-fitted into the shaft hole 201A with a predetermined gap.

  The ratchet gear 198 is formed by aluminum die casting, zinc die casting, or the like, has a substantially ring-shaped axial section, has a ratchet gear portion 35A formed on the outer peripheral portion, and a cylindrical fixed boss 211 is erected at the inner center position thereof. Yes. A spline groove into which a spline 202B formed on the other end side of the torsion bar 202 is press-fitted is formed on the inner peripheral surface of the fixed boss 211. Further, the inner peripheral portion of the ratchet gear portion 35A is formed to have an inner diameter into which the step portion 209 of the winding drum 201 can be fitted.

  Further, the ratchet gear 198 is seen from the end surface portion of the ratchet gear portion 35A on the winding drum 201 side over the entire circumference to the outer side in the radial direction from the outer diameter of the lock unit side flange portion 208 of the winding drum 201. A flange portion 212 that extends in a ring shape and extends from a portion slightly inside in the radial direction from the outer peripheral edge portion to a substantially right-angled outward direction (the left side direction in FIG. 23) over substantially the entire circumference. Is formed.

  Further, similarly to the ratchet gear 35, a shaft portion 116 is erected at the center portion of the end surface portion of the ratchet gear 198 on the lock unit 185 side, and a locking gear 213 constituting the lock unit 185 (see FIG. 18). The four through-holes 138 having substantially the same shape as the convex portion 136 in the circumferential direction and having a substantially rectangular cross section in the circumferential direction have a predetermined distance (for example, a distance of about 14 mm) radially outward from the rotation axis at an equal central angle. ) It is formed at a position facing each of the separated convex portions 136. Further, the end face portion of the ratchet gear 198 facing the locking gear 213 has an inner diameter of the positioning hole 137 at a position facing the positioning hole 137 between a pair of circumferentially adjacent through holes 138. A positioning pin 139 formed with substantially the same outer diameter is provided upright.

  To attach the ratchet gear 198 to the take-up drum 201, first, the torsion bar 202 is inserted into the shaft hole 201A, and the spline 202A is press-fitted into a spline groove formed on the inner side of the shaft hole 201A. Then, the fixed boss 211 of the ratchet gear 198 is inserted into the step 209 of the winding drum 201, and the spline 202 B formed on the other end side of the torsion bar 202 is press-fitted into the spline groove of the fixed boss 211. As a result, the ratchet gear 198 is attached to the winding drum 201 via the torsion bar 202 so as not to be relatively rotatable.

[Schematic configuration of lock unit]
Next, FIGS. 15, 16, 18, and 18 show a schematic configuration of the lock unit 185 that constitutes the lock mechanism 10 that stops the withdrawal of the webbing 3 in response to a sudden pull-out of the webbing 3 or a sudden acceleration of the vehicle. This will be described with reference to FIGS.

  As shown in FIGS. 15, 16, 18, 19, and 23, the lock unit 185 includes a mechanism cover 187, a locking gear 213, a lock arm 122, a sensor spring 123, a clutch 125, and a pilot lever 126. Yes. Therefore, the lock unit 185 has substantially the same configuration as the lock unit 9 according to the first embodiment, but a locking gear 213 and a mechanism cover 187 are provided instead of the locking gear 121 and the mechanism cover 111. Note that the locking gear 213 and the mechanism cover 187 are formed of synthetic resin, and the friction coefficient between members when they are in contact with each other is small.

  As shown in FIGS. 15, 18 and 23, the locking gear 213 constituting the lock unit 185 has substantially the same configuration as the locking gear 121 constituting the lock unit 9. However, the locking gear 213 is not provided with the tip end portion 133A at the end edge portion of the rotating shaft portion 133 on the mechanism cover 187 side, and the shaft hole portion 134A passes therethrough. Therefore, as shown in FIG. 23, when the shaft portion 116 of the ratchet gear 198 is fitted into the shaft hole portion 134A and the ratchet gear 198 is brought into contact with the locking gear 213, the mechanism cover of the rotating shaft portion 133 is obtained. The edge portion on the 187 side and the tip end portion of the shaft portion 116 of the ratchet gear 198 are formed so as to be located on substantially the same plane.

  Further, as shown in FIGS. 16, 18, 19 and 23, the mechanism cover 187 constituting the lock unit 185 has substantially the same configuration as the mechanism cover 111 constituting the lock unit 9. Accordingly, as shown in FIG. 19, the mechanism cover 187 has a substantially circular bottom surface portion 118 of the mechanism housing portion 127 formed with a substantially uniform thickness. Further, the peripheral edge portion of the base end portion of the support boss 131 erected on the bottom surface portion 118 has a predetermined depth L1 (for example, L1) to the inner side in the rotation axis direction of the winding drum unit 183 than the outer peripheral portion of the bottom surface portion 118. = 0.5 mm to 1 mm.) It is curved and formed so as to be elastically deformable outward in the rotation axis direction of the winding drum unit 183.

  However, the mechanism cover 187 is not provided with the holding portions 112 and the locking hooks 9 </ b> B constituting the lock unit 9. The support boss 131 erected at the center of the bottom surface portion 118 of the mechanism cover 187 is closed at the outer end in the rotational axis direction of the winding drum unit 183 by a wall portion 215 having substantially the same thickness as the bottom surface portion 118. Has been.

  Further, as shown in FIG. 23, the annular rib 135 of the locking gear 213 is fitted into the through hole 152 of the clutch 125, the rotation shaft portion 133 is inserted into the support boss 131 of the mechanism cover 187, and the rotation shaft portion 133 is inserted. When the front end of the support boss 131 is brought into contact with the base end of the rotary shaft 133, a predetermined gap (between the end 215 of the take-up drum unit 183 in the rotation axis direction and the wall 215 of the rotation shaft 133 is provided. For example, the gap is about 0.5 mm to 1 mm.).

Next, a state where the lock unit 185 is attached to the side wall portion 189 of the housing 188 will be described with reference to FIGS. 15, 16, 19, and 23.
As shown in FIGS. 15, 16, and 23, the lock unit 185 is attached to each attachment hole 191 of the side wall portion 189 from the outside in the rotation axis direction by each ny latch 9 </ b> A. Further, the shaft portion 116 of the ratchet gear 198 is fitted into the shaft hole portion 134A of the locking gear 213, and the positioning pin 139 of the ratchet gear 198 is fitted into the positioning hole 137 of the locking gear 213. A convex portion 136 is fitted into each through hole 138 of the ratchet gear 198.

  As a result, the locking gear 213 is coaxially attached to the ratchet gear 198 so as not to be relatively rotatable with the locking gear 213 in contact with the end surface of the ratchet gear 198 in the rotational axis direction. The rotating shaft 133 of the locking gear 213 is fitted into the support boss 131 of the mechanism cover 187 so that the rotating shaft 133 can rotate while the base end of the rotating shaft 133 is in contact with the distal end of the support boss 131. Has been.

  On the other hand, as shown in FIG. 19, the bottom surface portion 118 of the mechanism cover 187 is curved at a predetermined depth L1 to the inner side in the rotation axis direction of the winding drum unit 183 than the outer peripheral portion of the bottom surface portion 118. As shown, when the mechanism cover 187 is fixed to the outside of the side wall portion 189, the bottom surface portion 118 of the mechanism cover 187 is slightly curved to a surface substantially parallel to the side wall portion 189 or to the outside in the rotation axis direction. Forming a surface (for example, a surface that is curved about 0.5 mm to 1 mm outward in the rotational axis direction, and here, to the extent that the sensor housing portion 128 provided in the mechanism cover 187 is inward in the rotational axis direction. is there.).

  That is, the bottom surface portion 118 of the mechanism cover 187 forms a surface that is substantially parallel to the side wall portion 189 or slightly curved outward in the rotation axis direction when the mechanism cover 187 is fixed to the outside of the side wall portion 189. In this state, the base end portion of the rotation shaft portion 133 is provided to be rotatably supported. Therefore, when the mechanism cover 187 is not fixed to the outside of the side wall portion 189, the bottom surface portion 118 of the mechanism cover 187 is slightly curved to a surface substantially parallel to the side wall portion 189 or to the outside in the rotation axis direction. With the surface formed as a reference, the peripheral edge portion of the base end portion of the support boss 131 is formed so as to curve a predetermined depth L1 to the inner side in the rotation axis direction of the winding drum unit 183 than the outer peripheral portion of the bottom surface portion 118. ing.

  Thereby, the bottom surface portion 118 of the mechanism cover 187 has the peripheral edge portion of the base end portion of the support boss 131 wound by the support boss 131 being pressed outward by the ratchet gear 198 via the locking gear 213. The ratchet gear 198 is elastically deformed by a distance corresponding to the bending depth L <b> 1 outward in the rotation axis direction of the take-up drum unit 183, and the ratchet gear 198 is pressed and urged inward in the rotation axis direction via the support boss 131 and the locking gear 213.

  Accordingly, the force by which the bottom surface portion 118 of the mechanism cover 187 presses and biases the ratchet gear 198 to the inner side in the rotation axis direction through the support boss 131 and the locking gear 213 is applied to the peripheral edge portion of the base end portion of the support boss 131. It is proportional to the depth L1 of the winding drum unit 183 curved inward in the rotation axis direction from the outer peripheral portion of the bottom surface portion 118. Further, the larger the force for pressing and biasing, the stronger the backlash of the winding drum unit 183 can be suppressed.

As a result, the depth L1 for bending the bottom surface portion 118 of the mechanism cover 187 is such that the rotational resistance of the take-up drum unit 183 caused by being pressed and urged inward in the rotation axis direction hinders the webbing 3 from being pulled out and taken up. As long as there is no backlash, it can be set to any value required to suppress rattling.
The lock mechanism 10 is configured by the lock unit 185, the pawl 23, the torsion coil spring 26, the vehicle acceleration sensor 28, and the ratchet gear 198.

[Schematic configuration of winding spring unit]
Next, a schematic configuration of the winding spring unit 186 will be described with reference to FIGS. 15, 16, 20 to 23. 20 and 21 are exploded perspective views of the winding spring unit 186. FIG. FIG. 22 is a cross-sectional view of the spring seat 217.

  As shown in FIGS. 20 and 21, the winding spring unit 186 is fixed to a spiral spring 105 and a rib 106 whose outer end 105A is erected from the bottom surface of the inner peripheral edge. A spring case 192 that accommodates the spiral spring 105, a spring shaft 108 to which the inner end 105B of the spiral spring 105 is coupled and a spring force is urged, and a substantially flat spring sheet that is attached to the spring case 192 and covers the spiral spring 105 217. Therefore, the winding spring unit 186 has substantially the same configuration as the winding spring unit 8 according to the first embodiment, but a spring case 192 is provided instead of the spring case 107, and a spring seat 217 is further provided.

  As shown in FIGS. 20 to 23, the spring shaft 108 has a bottom surface portion in which a pin 109 erected substantially at the center position of the bottom surface portion 192A of the spring case 192 is inserted into the through hole 108A in the bottom surface portion of the spring shaft 108. The 192A side is rotatably supported. The end of the spring shaft 108 on the spring seat 217 side is a circular stepped portion 217B formed on the inner peripheral portion of the base end side of a substantially cylindrical boss portion 217A provided at the center of the spring seat 217. Is rotatably supported. The spring seat 217 is fixed by elastically locking the locking protrusions 218 provided at the three locations on the outer peripheral portion to the locking holes 219 provided on the open side peripheral edge of the spring case 192. Yes.

  As shown in FIG. 22, the spring seat 217 is formed to have a substantially uniform thickness, and a base end portion of a substantially cylindrical boss portion 217 erected at the center portion of the circular flat plate portion 220. The peripheral edge portion of the flat plate portion 220 is curved at a predetermined depth L2 (for example, L2 = 0.5 mm to 1 mm) to the inner side in the rotation axis direction of the winding drum unit 183 than the outer peripheral portion of the flat plate portion 220, and the winding drum unit 183. Are formed so as to be elastically deformable outward in the rotation axis direction.

  Further, as shown in FIG. 23, the shaft 205 of the take-up drum unit 183 is rotatable by being inserted into a substantially cylindrical boss portion 217A provided at the center portion of the spring seat 217 at the base end portion having a circular cross section. The front end portion having a substantially rectangular cross section is supported and inserted into a cylindrical hole 108B formed in a substantially rectangular cross section of the spring shaft 108 so that it cannot rotate relative to the spring shaft 108. Connected. As a result, the biasing force of the spiral spring 105 via the spring shaft 108 is constantly biased so that the winding drum unit 183 rotates in the winding direction of the webbing 3.

  A ring-shaped rib 221 is provided on the surface of the spring seat 217 on the side wall 193 side so as to cover the outer peripheral portion of the outer flange 207 formed at the end edge of the winding drum unit 183. In addition, a plurality of reinforcing ribs 223 are erected from the outer peripheral surface of the rib 221 radially outward to the outer peripheral portion. Further, among the plurality of reinforcing ribs 223, the upper end portion of each reinforcing rib 223 facing the lower peripheral edge portion of the through hole 194 formed in the side wall portion 193 of the housing 188 extends from the outer peripheral surface of the rib 221 to the through hole. A positioning portion 223A that protrudes at a height substantially equal to the thickness of the side wall portion 193 is formed up to a position facing the inner peripheral surface of 194.

  In addition, a pair of cylindrical positioning bosses 225 are erected on the outside of the rib 221 of the spring seat 217. In addition, a pair of positioning holes 226 (see FIG. 15) into which the positioning bosses 225 are inserted are formed in the upper peripheral edge portion of the through hole 194 formed in the side wall portion 193 of the housing 188.

Next, a state in which the winding spring unit 186 is attached to the side wall portion 193 of the housing 188 will be described with reference to FIGS. 15, 16, 22, and 23.
As shown in FIGS. 15, 16, and 23, the take-up spring unit 186 includes the positioning bosses 225 inserted into the pair of positioning holes 226 formed in the side wall portion 193 of the housing 188, and It is attached to each attachment hole 195 of the side wall part 193 from the outside in the rotation axis direction by the ny latch 9A. Further, the shaft 205 of the winding drum 201 is fitted into the boss portion 217A of the spring seat 217, and the tip portion of the shaft 205 formed in a substantially rectangular shape is formed in a substantially rectangular shape in the spring shaft 108. It is inserted into the cylindrical hole 108B and connected to the spring shaft 108 so as not to be relatively rotatable.

  Thus, the columnar base end portion of the shaft 205 of the winding drum 201 is in a state where the distal end portion of the boss portion 217A of the spring seat 217 is in contact with the winding spring side flange portion 203 of the winding drum 201. It is rotatably supported. Further, the biasing force of the spiral spring 105 via the spring shaft 108 always biases the winding drum unit 183 so as to rotate in the webbing winding direction. Further, the positioning portions 223A of the reinforcing ribs 223 are fitted into the through holes 194 so as to have substantially the same height as the inner surface of the side wall portion 193.

  On the other hand, as shown in FIG. 22, the circular flat plate portion 220 of the spring seat 217 is such that the peripheral edge portion of the base end portion of the boss portion 217 </ b> A is in the rotational axis direction of the winding drum unit 183 than the outer peripheral portion of the flat plate portion 220. Although a predetermined depth L2 is curved inward, as shown in FIG. 23, when the take-up spring unit 186 is fixed to the outside of the side wall portion 193, the flat plate portion 220 of the spring seat 217 is moved to the side wall portion 193. A substantially parallel surface is formed.

  That is, the flat plate portion 220 of the spring seat 217 is formed in a state where a surface substantially parallel to the side wall portion 193 is formed when the winding spring unit 186 is fixed to the outside of the side wall portion 193. 205 is provided to rotatably support a base end portion having a circular section. Therefore, when the take-up spring unit 186 is not fixed to the outside of the side wall portion 193, the flat plate portion 220 of the spring seat 217 is a boss on the basis of a state in which a plane substantially parallel to the side wall portion 193 is formed. The peripheral edge portion of the base end portion of the portion 217 </ b> A is formed so as to bend a predetermined depth L <b> 2 to the inner side in the rotation axis direction of the winding drum unit 183 than the outer peripheral portion of the flat plate portion 220.

  Accordingly, the flat plate portion 220 of the spring seat 217 is configured such that the boss portion 217 </ b> A is pressed outward in the rotation axis direction by the take-up spring side flange portion 203 of the take-up drum 201, so that the peripheral portion of the base end portion of the boss portion 217 </ b> A However, the winding drum unit 183 is elastically deformed outward by the distance corresponding to the bending depth L2 in the rotational axis direction, and presses and urges the winding drum 201 inward in the rotational axis direction via the boss portion 217A.

  Therefore, the force by which the flat plate portion 220 of the spring seat 217 presses and urges the winding drum 201 inward in the rotation axis direction via the boss portion 217A is such that the peripheral edge portion of the base end portion of the boss portion 217A It is proportional to the magnitude of the depth L2 that is curved inward in the rotation axis direction of the winding drum unit 183 rather than the outer peripheral portion. Further, the larger the force for pressing and biasing, the stronger the backlash of the winding drum unit 183 can be suppressed.

  As a result, the depth L2 for bending the flat plate portion 220 of the spring seat 217 is such that the rotational resistance of the winding drum unit 183 caused by being pressed and urged inward in the rotational axis direction hinders the webbing 3 from being pulled out and taken up. As long as there is no backlash, it can be set to any value required to suppress rattling.

  Further, the flat plate portion 220 of the spring seat 217 is elastically deformed outward in the rotation axis direction to form a surface substantially parallel to the bottom surface portion 192A of the spring case 192. Thereby, a substantially uniform gap is formed between the flat plate portion 220 of the spring seat 217 and the spiral spring 105.

  As described in detail above, in the seatbelt retractor 181 according to the second embodiment, the lock unit 185 is attached to the side wall part 189 of the housing 188 so that the bottom face part 118 of the mechanism cover 187 is in the direction of the rotation axis before the attachment. The support boss is elastically deformed outward in the rotational axis direction of the winding drum unit 183 so as to be substantially parallel to the side wall 189 or slightly curved outward in the rotational axis direction from a state where the predetermined depth L1 is curved inward. The ratchet gear 198 is pressed and urged inward in the rotation axis direction via the 131 and the locking gear 213.

  Further, by attaching the take-up spring unit 186 to the side wall portion 193 of the housing 188, the flat plate portion 220 of the spring seat 217 is curved with respect to the side wall portion 193 from a state where the flat plate portion 220 is curved to the inner side in the rotation axis direction by a predetermined depth L2. Therefore, the winding drum 201 is elastically deformed outward in the rotational axis direction of the winding drum unit 183 so that the winding drum 201 is pressed and urged inward in the rotational axis direction via the boss portion 217A.

  As a result, the lock unit 185 and the take-up spring unit 186 are attached to the side wall portions 189 and 193 of the housing 188, so that both ends of the take-up drum unit 183 are connected to the support boss 131 of the mechanism cover 187 and the boss portion 217 A of the spring seat 217. And can be urged to press inward in the respective rotation axis directions. Therefore, rattling in the direction of the rotation axis of the winding drum unit 183 can be suppressed via the mechanism cover 187 and the spring seat 217.

  Further, when the mechanism cover 187 is fixed to the outside of the side wall portion 189, the bottom surface portion 118 of the mechanism cover 187 may be set so as to form a surface that slightly curves outward in the rotational axis direction with respect to the side wall portion 189. Good. Also in this case, the deformation amount of the bottom surface portion 118 of the mechanism cover 187 that is curved outward in the rotational axis direction is formed by bending the bottom surface portion 118 by a predetermined depth L1 inward in the rotational axis direction before being attached. (Stroke amount) can be made larger than the deformation amount that the bottom surface portion 118 is curved outward in the rotational axis direction with respect to the side wall portion 189 after being fixed, and the ratchet gear 198 is reliably pressed and urged inward in the rotational axis direction. can do.

  Further, since the distal end portion of the support boss 131 of the mechanism cover 187 is brought into contact with the proximal end portion of the rotating shaft portion 133 of the locking gear 213, the peripheral edge portion of the proximal end portion of the support boss 131 is brought closer to the locking gear 213 side. Accordingly, the take-up drum unit 183 of the seat belt retractor 181 can be downsized in the rotation axis direction.

  When the take-up spring unit 186 is attached to the side wall portion 193, the flat plate portion 220 of the spring seat 217 is substantially parallel to the side wall portion 193, and also substantially to the bottom surface portion 192 A of the spring case 192. Become parallel.

  As a result, a substantially uniform gap can be formed between the flat plate portion 220 of the spring seat 217 and the spiral spring 105, and the rotational biasing force by the spiral spring 105 can be stabilized. In addition, the gap between the flat plate portion 220 of the spring seat 217 and the spiral spring 105 can be minimized, and the seat belt retractor 181 can be further downsized in the rotation axis direction.

  Further, the bottom surface portion 118 of the mechanism cover 187 is curved by a predetermined depth L1 so that the base end portion of the support boss 131 is located at the innermost side in the rotation axis direction of the winding drum unit 183 at the bottom surface portion 118. Further, the flat plate portion 220 of the spring seat 217 is curved by a predetermined depth L2 so that the base end portion of the boss portion 217A is located at the innermost side in the rotation axis direction of the winding drum unit 183 in the flat plate portion 220.

  Thus, when the mechanism cover 187 is attached to the outer side of the winding drum unit 183 in the rotation axis direction of the side wall portion 189 and the shaft portion 116 of the ratchet gear 198 is rotatably supported via the support boss 131 and the locking gear 213. In this case, the bottom surface portion 118 of the mechanism cover 187 can be elastically deformed with almost no deviation, and the winding drum unit 183 can be reliably pressed and urged inward in the rotation axis direction.

  Further, a winding spring unit 186 is attached to the side wall 193 on the outer side in the rotation axis direction of the winding drum unit 183, and a base end portion having a circular cross section of the shaft 205 of the winding drum 201 via the boss portion 217 A of the spring seat 217. Is rotatably supported, the flat plate portion 220 of the spring seat 217 can be elastically deformed almost without deviation, and the winding drum unit 183 can be reliably pressed and urged inward in the rotation axis direction.

  In addition, a predetermined gap can be reliably formed between the bottom surface portion 118 of the mechanism cover 187 and the ratchet gear 198, and the winding drum unit 183 can be stably and rotatably supported. In addition, a predetermined gap can be reliably formed between the flat plate portion 220 of the spring seat 217 and the outer flange 207 of the winding drum 201, and the winding drum unit 183 can be stably and rotatably supported. Further, by minimizing these predetermined gaps, it is possible to further reduce the size of the take-up drum unit 183 of the seat belt retractor 181 in the rotation axis direction.

  The present invention is not limited to the first and second embodiments, and various improvements and modifications can be made without departing from the scope of the present invention.

  For example, in the seatbelt retractor 181 according to the second embodiment, the bottom surface portion 118 of the mechanism cover 187 of the lock unit 185 includes an outer peripheral portion of the bottom surface portion 118 and a peripheral edge portion of the base end portion of the support boss 131. While being located on the same plane, the flat plate portion 220 of the spring seat 217 of the take-up spring unit 186 may be formed so as to increase rigidity and be difficult to elastically deform in the direction of the rotation axis. Then, the lock unit 185 and the take-up spring unit 186 may be attached to the side wall portions 189 and 193 of the housing 188.

  Then, the flat plate portion 220 of the spring seat 217 of the winding spring unit 186 attached to the side wall portion 193 is substantially parallel to the side wall portion 193 from a state where the flat plate portion 220 is curved to the inner side in the rotation axis direction by a predetermined depth L2. The bottom surface 118 of the mechanism cover 187 may be configured so as to be hardly elastically deformed outward in the rotation axis direction of the take-up drum unit 6.

  As a result, the winding drum 201 is pressed and urged inward in the rotational axis direction mainly through the boss portion 217A of the spring seat 217, so that the backlash in the rotational axis direction of the winding drum unit 183 is also suppressed in this configuration. be able to.

DESCRIPTION OF SYMBOLS 1,181 Retractor for seat belts 3 Webbing 5, 182 Housing unit 6, 183 Winding drum unit 8, 186 Winding spring unit 9, 185 Lock unit 10 Lock mechanism 11, 188 Housing 12, 13, 189, 193 Side wall part 23 Paul 35, 198 Ratchet gear 65, 201 Winding drum 105 Spiral spring 107, 192 Spring case 111, 187 Mechanism cover 107B, 118, 192A Bottom part 121, 213 Locking gear 125 Clutch 131 Support boss 217 Spring seat 217A Boss part 220 Flat part

Claims (4)

A housing comprising a pair of opposite side wall portions ;
With winding a rotatably housed in webbing inside the pair of side wall portions facing each of said housing, a winding drum that rotates in the webbing pull-out direction by the webbing is pulled out,
A rotating shaft that is disposed on the outer side of the winding drum in the rotational axis direction of at least one of the pair of side wall portions and rotates from one end facing the one side wall portion of the winding drum is rotated. A support member for supporting the support;
With
Said supporting member includes a rotation support portion that rotatably supports the rotation shaft of the one end of the winding drum is disposed in the center thereof, said one of said winding drum extends in the circumferential direction from the rotating support Consisting of a bottom surface curved to a predetermined depth on the side of the take-up drum that presses and urges the inner side of the side wall ,
When the support member is rotatably supporting the rotation shaft of the one end of the winding drum, the bottom surface portion of the support member by elastic deformation, the rotating support said winding drum of the one A retractor for a seat belt, which is pressed and urged toward the inside of a side wall portion . Provided on the one end side of the winding drum, and a locking mechanism for preventing rotation of the webbing pullout direction of the take-up drum in case of emergency,
With attached to a rotating shaft outwardly of the winding drum before Symbol one side wall portion to accommodate the locking mechanism, and a mechanism cover for rotatably supporting the rotation shaft of the one end of the winding drum,
With
The seat belt retractor according to claim 1, wherein the support member is the mechanism cover . Attached to the rotation shaft outward of the winding drum of the one side wall portion, comprising a winding mounting biasing mechanism for the winding always-on rotation urging the drum in the webbing take-up direction,
The winding attachment urging mechanism is
A spiral spring you turn biased rotation shaft of the one end side of the take-up drum in the webbing take-up direction,
A spring case that houses the spiral spring is attached to the side wall portion of the front SL one,
A spring seat that is disposed between the spiral spring and the one side wall, and that is attached to the spring case and rotatably supports the rotary shaft on the one end side of the winding drum;
Have
Wherein the support member, a seat belt retractor according to claim 1 which before characterized kiss pulling sheets der Rukoto. The support member, when the rotatably supporting said one end side of the winding drum, and the bottom portion is elastic deformation, and is formed to be substantially parallel to the one side wall portion The retractor for a seat belt according to any one of claims 1 to 3, wherein the retractor is for a seat belt.

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