JP2015157633A - Fitting part structure of vehicle sensor for seat belt retractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise during operation of a vehicle sensor without occurence of rising of a price of a seat belt retractor.SOLUTION: A vehicle sensor 1 is mounted in a sensor storage chamber 4 of a case 3. A lever stopper 42 is formed integrally with the case 3. The lever stopper 42 abuts against a claw 8 of a sensor lever 7 thereby blocking rotation of the sensor lever 7, when a sensor weight 11 of the vehicle sensor 1 pushes up the sensor lever 7, whereby it is prevented that the claw 8 of the sensor lever 7 too enters between teeth 6, 6 of a gear 5. The lever stopper 42 is integrally provided with: an elastic deformation piece 48 which contacts the claw 8 of the sensor lever 7, and elastically deforms and absorbs an impact generated at the time of collision against the claw 8 of the sensor lever 7; and a load receiving surface (concave surface) which irregularly engages with a convex surface of the elastic deformation piece 48 elastically deformed by the claw 8 of the sensor lever 7 to prevent the deformation of the elastic deformation piece 48.

Description

  The present invention relates to a mounting portion structure of a vehicle sensor for a seat belt retractor provided in a vehicle such as an automobile.

  A seat belt retractor installed in a vehicle such as an automobile stops (locks) the withdrawal of a webbing (belt) when a vehicle sensor detects a change in vehicle speed at the time of a collision or the like (Patent Document 1). reference).

  FIG. 16 is a view showing a vehicle sensor 100 (a vehicle sensor for seat belt retractor) mounted on the case 108 of the seat belt retractor.

  As shown in FIG. 16, the vehicle sensor 100 is configured such that the spherical sensor weight 101 is in a repose position (sensor weight holding hole) in the sensor holder 102 during normal operation of the vehicle (when stopped or when there is no sudden speed change). 103) and will not operate.

  On the other hand, as shown in FIG. 17, the vehicle sensor 100 detects the sensor weight 101 due to inertia when the vehicle traveling speed changes suddenly due to a vehicle collision or the like, and the acceleration acting on the sensor weight 101 exceeds a predetermined value. It moves from the repose position in the holder 102, the sensor weight 101 pushes up (rotates) the sensor lever 104, and the teeth 107 of the gear 106 attached to the webbing take-up drum with the claw 105 formed at the tip of the sensor lever 104. , 107. At this time (when the vehicle sensor 100 is activated), the sensor lever 104 of the vehicle sensor 100 is abutted against the lever stopper 110 of the case 108 of the seat belt retractor to which the vehicle sensor 100 is attached, and the pawl 105 is engaged with the teeth of the gear 106. The lever stopper 110 prevents the lever 107 from turning in the direction between the 107 and 107. As a result, the vehicle sensor 100 can prevent the rotation of the gear 106 in the webbing pull-out direction, and can start the webbing take-up drum locking mechanism (webbing locking mechanism).

  However, in recent years, the quietness of the interior of an automobile has progressed, and the collision noise between the sensor lever 104 and the lever stopper 110 when the vehicle sensor 100 is operating has become more easily detected by the seat belt wearer. Reducing the collision noise between the sensor lever 104 and the lever stopper 110 is a problem.

  In order to solve such a problem, a technique disclosed in Patent Document 2 (a technique in which an elastomer is coated on a portion of the sensor lever that collides with another member) is applied, and the lever of the sensor lever 104 is applied. The part that collides with the stopper 110 is coated with elastomer, or the part of the lever stopper 110 that collides with the sensor lever 104 is coated with elastomer, and the impact at the time of collision between the sensor lever 104 and the lever stopper 110 is reduced with the elastomer. However, it is conceivable to reduce noise during operation of the vehicle sensor 100.

JP 2003-212086 A Japanese Patent Laid-Open No. 7-101311

  However, when the sensor lever 104 is covered with an elastomer or the lever stopper 110 is covered with an elastomer, the number of manufacturing steps of the vehicle sensor 100 increases by the step of covering the sensor lever 104 with the elastomer, or the case 108. The manufacturing man-hours of the vehicle sensor increase by the process of covering the lever stopper 110 with the elastomer, resulting in a decrease in the production efficiency of the vehicle sensor 100 or the case 108, and an increase in the product price of the vehicle sensor 100 or the case 108. There arises a new problem that the price of the seat belt retractor using the vehicle sensor 100 and the case 108 increases.

  Therefore, an object of the present invention is to reduce noise during operation of a vehicle sensor without causing an increase in the price of a seat belt retractor.

  (1) When the sensor weight 11 accommodated in the sensor holder 10 moves in the sensor holder 10 due to inertia, the sensor weight 11 rotates and pushes up the sensor lever 7 made of synthetic resin. The seat belt retractor is configured so that the claw 8 of the sensor lever 7 is bitten between the teeth 6 and 6 of the gear 5 attached to the webbing take-up drum and the gear 5 is prevented from rotating in the webbing pull-out direction. Vehicle for seat belt retractor comprising: vehicle sensor 1; and (2) a synthetic resin case 3 that supports the webbing take-up drum rotatably and has the seat belt retractor vehicle sensor 1 attached thereto. The present invention relates to a sensor mounting portion structure.

  In the first aspect of the present invention, when the sensor weight 11 pushes up the sensor lever 7, the case 3 abuts against the claw 8 of the sensor lever 7 to prevent the sensor lever 7 from rotating, A lever stopper 42 is integrally formed so that the claw 8 of the sensor lever 7 does not bite between the teeth 6 and 6. The lever stopper 42 (1) abuts on the claw 8 of the sensor lever 7 and elastically deforms pieces 48 and 53 that elastically deform and absorb the impact when the sensor lever 7 collides with the claw 8. (2) The elastic deformation pieces 48 and 53 are located in the deformation direction of the elastic deformation pieces 48 and 53 via the gaps 50 and 54 and contact the elastic deformation pieces 48 and 53 elastically deformed by the claw 8 of the sensor lever 7. In addition, load receiving surfaces 51 and 55 that prevent deformation of the elastic deformation pieces 48 and 53 are integrally formed.

  In the invention according to claim 1, the load receiving surface 51 is a concave surface, the side corresponding to the load receiving surface 51 of the elastic deformation piece 48 is a convex surface 52, and the claw 8 of the sensor lever 7 When the elastically deformed elastically deformed piece 48 is brought into contact with the load receiving surface 51, the convex surface 52 and the load receiving surface 51 are engaged with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the noise at the time of operation | movement of a vehicle sensor can be reduced, without causing the price increase of the seatbelt retractor which uses a vehicle sensor and a case as a component.

1 is a partial cross-sectional view of a seat belt retractor showing a mounting portion structure of a vehicle sensor for a seat belt retractor according to a first embodiment of the present invention. FIG. 2A is a front view of a vehicle sensor in a normal state of the vehicle (when stopped or when there is no sudden speed change), FIG. 2A is an assembly state diagram of the vehicle sensor, and FIG. 2B is a vehicle sensor. FIG. FIG. 3A is a longitudinal sectional view of the vehicle sensor 1 shown in FIG. 2, FIG. 3A is a longitudinal sectional view in an assembled state of the vehicle sensor, and FIG. 3B is a longitudinal sectional view when the vehicle sensor is disassembled. is there. 4A and 4B are diagrams showing a sensor holder of a vehicle sensor, in which FIG. 4A is a front view of the sensor holder, FIG. 4B is a left side view of the sensor holder, and FIG. 4C is a rear view of the sensor holder. 4 (d) is a plan view of the sensor holder, and FIG. 4 (e) is a back (bottom) view of the sensor holder. It is a longitudinal cross-sectional view of a sensor holder, and is a cross-sectional view of the sensor holder cut along the line A1-A1 of FIG. FIG. 6A is a longitudinal sectional view of the vehicle sensor showing the first operating state, and FIG. 6B is a longitudinal sectional view of the vehicle sensor showing the second operating state. 7A and 7B are diagrams illustrating a sensor lever of a vehicle sensor, in which FIG. 7A is a rear view of the sensor lever, FIG. 7B is a plan view of the sensor lever, and FIG. 7C is orthogonal to the lower surface side of the sensor weight holder. FIG. 7 (d) is a left side view of the sensor lever shown in FIG. 7 (a), and FIG. 7 (e) is a sensor shown in FIG. 7 (a). It is a right view of a lever. FIG. 8A is a front view of the sensor lever, and FIG. 8B is a longitudinal sectional view of the sensor lever shown in FIG. It is a figure which shows a part of lever stopper integrally formed in the case, Fig.9 (a) is a front view before elastic deformation piece deformation | transformation of a lever stopper, FIG.9 (b) is before elastic deformation piece deformation | transformation of a lever stopper. FIG. 9C is a right side view of the lever stopper before deformation of the elastically deformed piece. It is a figure which shows the state by which the elastic deformation piece of the lever stopper was deform | transformed with the nail | claw of the sensor lever, Fig.10 (a) is a front view after elastic deformation piece deformation | transformation of a lever stopper, FIG.10 (b) is a lever stopper. FIG. 10C is a plan view after the elastic deformation piece is deformed, and FIG. 10C is a right side view after the elastic deformation piece of the lever stopper is deformed. It is a figure which shows the state which the sensor lever and lever stopper of the vehicle sensor collided, and is a figure which expands and shows a part of FIG. It is a figure which shows the modification 1 of a lever stopper, Fig.12 (a) is a front view which shows the state before a deformation | transformation of the elastic deformation piece of a lever stopper, FIG.12 (b) is a state after a deformation | transformation of the elastic deformation piece of a lever stopper. It is a front view which shows a state. It is a figure which shows the modification 2 of a lever stopper, Fig.13 (a) is the front view (front view which fractures | ruptures and shows one part) before the elastic deformation piece of a lever stopper, FIG.13 (b) is a lever stopper. FIG. 13C is a plan view before the elastic deformation piece is deformed, and FIG. 13C is a right side view of the lever stopper before the elastic deformation piece is deformed. It is a figure which shows the state by which the elastic deformation piece of the lever stopper which concerns on the modification 2 was deform | transformed with the nail | claw of the sensor lever, and Fig.14 (a) is a front view after elastic deformation piece deformation | transformation of a lever stopper. 14 (b) is a plan view of the lever stopper after the elastic deformation piece is deformed, and FIG. 14 (c) is a right side view of the lever stopper after the elastic deformation piece is deformed. It is a figure which expands and shows a part of attachment part structure of the vehicle sensor for seatbelt retractors which concerns on 2nd Embodiment of this invention, Fig.15 (a) is a state before the nail | claw of a sensor lever collides with a lever stopper. FIG. 15B is a diagram showing a state after the claw of the sensor lever collides with the lever stopper. It is a partial sectional view of a seat belt retractor showing a mounting part structure of a conventional vehicle sensor for a seat belt retractor, and shows a state before the vehicle sensor is activated. It is a partial sectional view of a seat belt retractor showing a mounting part structure of a conventional vehicle sensor for a seat belt retractor, and shows a state when the vehicle sensor is activated.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a view for explaining an attachment portion structure of a vehicle sensor 1 for a seat belt retractor (hereinafter abbreviated as a vehicle sensor) according to a first embodiment of the present invention.

  As shown in FIG. 1, a vehicle sensor 1 is mounted in a sensor housing chamber 4 of a case 3 that rotatably supports a rotating shaft 2 of a webbing take-up drum. When the vehicle sensor 1 detects an abrupt speed change of the vehicle such as when the vehicle collides, the sensor lever 7 is interposed between the teeth 6 and 6 of the gear 5 that is coaxially mounted with the rotary shaft 2 of the webbing take-up drum. The claw 8 is bitten to prevent the gear 5 from rotating in the webbing pull-out direction, and the webbing take-up drum (not shown) can be started with a lock mechanism (webbing lock mechanism). The claw 8 and the gear 5 of the sensor lever 7 constitute a ratchet mechanism.

(Overall configuration of vehicle sensor)
2 to 3 are diagrams showing the vehicle sensor 1. Among these, FIG. 2 is a front view of the vehicle sensor 1 in a normal state of the vehicle (when stopped or when there is no sudden speed change), and FIG. 2A is an assembly state diagram of the vehicle sensor 1. FIG. 2B is an exploded view of the vehicle sensor 1. 3 is a longitudinal sectional view of the vehicle sensor 1 shown in FIG. 2, FIG. 3 (a) is a longitudinal sectional view of the vehicle sensor 1 in an assembled state, and FIG. 3 (b) is a vehicle sensor 1. It is a longitudinal cross-sectional view at the time of decomposition | disassembly.

  As shown in these drawings, the vehicle sensor 1 includes a sensor holder 10 made of a synthetic resin, a sensor weight 11 made of metal contained in the sensor holder 10 and formed in a spherical shape, and one end of the sensor holder 10. The sensor lever 7 is made of synthetic resin and is mounted on the sensor weight 11 so as to be swingable.

(Sensor holder for vehicle sensor)
As shown in FIGS. 2 to 5, the sensor holder 10 includes a bottomed sensor weight receiving recess 12 that opens upward, and support shafts 15 that protrude from both side surfaces 13 and 14 on one end side of the sensor lever 7. And a pair of support legs 17 and 18 for rotatably supporting 16 (see FIGS. 7 to 8).

  The sensor weight receiving recess 12 is flat, parallel to the XY direction, and has a bottom surface 20 so as to have a circular shape in plan view, and has a tapered shape for seating the sensor weight 11 on the center of the bottom surface 20. A countersink surface 21 is formed, and a through hole 22 having a smaller diameter than the opening edge on the bottom surface side of the countersink surface 21 and concentric with the countersink surface 21 communicates the internal space of the sensor weight housing recess 12 with the external space. Is formed. A countersink surface side opening edge 23 of the through hole 22 formed in the sensor weight housing recess 12 holds the sensor weight 11 in the center of the sensor weight housing recess 12. Further, the countersink surface side opening edge 23 of the through hole 22 formed in the sensor weight housing recess 12 allows the sensor weight 11 to be attached to the sensor weight housing recess 12 until the inertial force acting on the sensor weight 11 exceeds a predetermined value. It is a rest position of the sensor weight 11 held in the center. Therefore, the sensor weight 11 does not move away from the center (rest position) of the sensor weight housing recess 12 and does not move in the sensor weight housing recess 12 (see FIG. 3A).

  The sensor weight housing recess 12 has a substantially tapered cylindrical wall surface 25 extending from the upper surface 24 of the sensor holder 10 formed so as to be parallel to the bottom surface 20 along the Z axis (direction perpendicular to the bottom surface 20). It is connected to the bottom surface 20 via the corner surface 26. The internal space of the sensor weight housing recess 12 is formed by a bottom surface 20, a countersink surface 21, a corner surface 26, and a wall surface 25. Here, the wall surface 25 is formed so that the shape in plan view is concentric with the bottom surface 20, and is formed so that gaps are formed at equal intervals between the sensor weight 11 held at the center of the sensor weight housing recess 12. Thus, the sensor weight 11 held in the center of the sensor weight housing recess 12 can move in the sensor holder housing recess 12 by the gap. The corner surface 26 is formed so as not to contact the sensor weight 11 (see FIGS. 3A, 6A, and 6B).

  The pair of support legs 17 and 18 are formed so as to protrude from the upper surface 24 of the sensor holder 10 in the Z-axis direction (upward), and accommodate the support shafts 15 and 16 of the sensor lever 7 in a swingable manner. Shaft holes 27 and 28 are formed (see FIG. 7). The pair of support legs 17 and 18 can be bent and deformed in directions away from each other when the support shafts 15 and 16 of the sensor lever 7 are fitted into the shaft holes 27 and 28. After the support shafts 15 and 16 are fitted into the shaft holes 27 and 28, they are elastically restored to their original postures (see FIG. 7). As a result, the support shafts 15 and 16 of the sensor lever 7 swing into the shaft holes 27 and 28 of the pair of support legs 17 and 18 without coming out of the shaft holes 27 and 28 of the pair of support legs 17 and 18. Supported as possible. The pair of support legs 17 and 18 are formed such that one support leg 18 is longer in the Z-axis direction than the other support leg 17 and is easily deformed. Further, one support leg 18 has an inclined surface 30 on the upper end side and the side facing the other support leg 17, and the support shaft 16 of the sensor lever 7 is moved along the inclined surface 30. It is easily bent and deformed only by being pushed into the other support leg portion 17 so that the support shafts 15 and 16 of the sensor lever 7 and the shaft holes 27 and 28 can be easily engaged. It has been devised. The shaft hole 28 of one support leg 18 and the shaft hole 27 of the other support leg 17 have the same size (hole diameter) as the thickness (axis diameter) of the support shafts 16 and 15 of the sensor lever 7. The sensor lever 7 is devised so that the sensor lever 7 can be assembled to the sensor holder 10 in a correct posture.

  Further, the sensor holder 10 has positioning projections 33 and 34 formed on both side surfaces 31 and 32 thereof. The positioning projections 33 and 34 are engaged with positioning recesses 35 and 36 as guide rails formed in the sensor housing chamber 4 of the case 3 (see FIG. 1). When the vehicle sensor 1 is mounted in the sensor housing chamber 4 with the positioning protrusions 33 and 34 of the sensor holder 10 engaged with the positioning recesses 35 and 36 of the sensor housing chamber 4, It will be hold | maintained in the sensor storage chamber 4 in the positioned state (refer FIG. 1).

  Further, the sensor holder 10 prevents the sensor weight 11 from coming out of the gap with the sensor lever 7 even if the sensor holder 10 rotates as much as possible until the rotation stopper 37 of the sensor lever 7 contacts the upper surface 24. The depth of the housing recess 12 is determined (see FIG. 6).

(Sensor lever of vehicle sensor)
As shown in FIGS. 7 to 8, the sensor lever 7 is fitted on both side surfaces 13 and 14 on one end side so as to be swingable in the shaft holes 27 and 28 of the support leg portions 17 and 18 of the sensor holder 10. Support shafts 15 and 16 are respectively formed (see FIGS. 2 and 4). Further, on the other end side of the sensor lever 7, a sensor weight holder 38 that is placed on the sensor weight 11 accommodated in the sensor holder 10 is formed. On the lower surface side of the sensor weight retainer 38, a substantially frustoconical sensor weight accommodation surface (concave surface) 40 that contacts the sensor weight 11 is formed. The sensor weight accommodation surface 40 contacts the surface of the sensor weight 11. (See FIGS. 3 and 6). Further, the sensor lever 7 has a claw 8 protruding from the upper surface on the other end side, the tip side of the claw 8 is formed at an acute angle, and the tip side of the claw 8 is bitten between the teeth 6 and 6 of the gear 5. (See FIG. 1). The claw 8 of the sensor lever 7 is formed in a tongue shape so as to have a width dimension smaller than the width dimension of the arm portion 41 connecting the sensor weight presser 38 and the support shafts 15 and 16 (particularly, (Refer Fig.7 (a)-(c)).

  Further, when the sensor lever 7 is rotated so that the sensor lever 7 is lifted against its own weight on the lower surface on one end side of the sensor lever 7, a rotation stopper that contacts the upper surface 24 of the sensor holder 10 and prevents the rotation. 37 is protrudingly formed. The rotation stopper 37 prevents the sensor weight 11 from coming out of the gap between the upper surface 24 of the sensor holder 10 and the sensor lever 7.

(Case lever stopper)
As shown in FIG. 1, a synthetic resin lever stopper 42 is integrally formed on the upper part of the sensor housing chamber 4 of the case 3 made of synthetic resin. Between the tip of the lever stopper 42 and the upper opening edge 43 of the sensor housing chamber 4, the pawl 8 of the sensor lever 7 of the vehicle sensor 1 mounted in the sensor housing chamber 4 is connected to the teeth 6, 6 of the gear 5. A window 44 is formed that allows it to protrude to a position that bites in between. The lever stopper 42 abuts on the claw 8 of the sensor lever 7 lifted by the sensor weight 11 moved in the sensor weight receiving recess 12 of the sensor holder 10, prevents the rotation of the sensor lever 7, and the teeth of the gear 5. Intrusion of the nail 8 between 6 and 6 is regulated.

  As shown in FIGS. 1, 9, and 11, the lever stopper 42 has a lower surface 45 parallel to the bottom surface 20 of the sensor holder 10 of the vehicle sensor 1 mounted in the sensor housing chamber 4 of the case 3. The tip 46 is formed in a direction parallel to the rotation axis 47 of the sensor lever 7 of the vehicle sensor 1 attached in the sensor housing chamber 4 of the case 3 (the Y-axis direction in FIGS. 1 and 11). Are formed along. The lever stopper 42 has a width dimension (a dimension along the Y-axis direction in FIGS. 1 and 11) of the claw 8 of the sensor lever 7 (a dimension along the Y-axis direction in FIGS. 1 and 11). It is formed to have a larger dimension.

  FIG. 9 is a view showing a detailed shape of the lever stopper 42. 9A is a front view showing a part of the lever stopper 42, FIG. 9B is a plan view showing a part of the lever stopper 42, and FIG. It is a side view which shows a part.

  As shown in FIG. 9, the lever stopper 42 is integrally formed with a cantilevered elastic deformation piece 48 so as to be positioned along the width direction of the lever stopper 42. When the claw 8 of the sensor lever 7 comes into contact, the elastic deformation piece 48 elastically deforms and absorbs an impact at the time of collision with the claw 8 of the sensor lever 7 (see FIGS. 10 and 11). . The elastic deformation piece 48 constitutes a part of the distal end side of the lever stopper 42 and bends and deforms in a cantilever shape with the one end side in the width direction of the lever stopper 42 as a base end (base).

  As shown in FIG. 9, the lever stopper 42 is integrally formed with a load receiving surface 51 so as to be positioned via the gap 50 in the deformation direction of the elastic deformation piece 48. Therefore, the elastically deformable piece 48 of the lever stopper 42 is bent and deformed by the gap 50 between the lever stopper 42 and the shock at the time of collision with the claw 8 of the sensor lever 7 can be absorbed. The load receiving surface 51 of the lever stopper 42 abuts on the elastic deformation piece 48 that is bent and deformed (elastically deformed) by the claw 8 of the sensor lever 7, thereby preventing deformation of the elastic deformation piece 48. (See FIGS. 10 and 11). The gap 50 is a slit that extends in the width direction from the other widthwise end of the lever stopper 42 toward the widthwise one end and is orthogonal to the bottom surface 45 of the lever stopper 42. It is a slit that penetrates the tip side in the plate thickness direction (direction along the Z-axis). The load receiving surface 51 is formed in parallel with the YZ plane.

(Vehicle sensor operation)
As shown in FIG. 3 (a), the vehicle sensor 1 is configured so that the sensor weight 11 is in a rest position (sensor weight holding hole) in the sensor holder 10 when the vehicle is in a normal state (when stopped or when there is no sudden speed change). The through hole 22 that functions as a holding hole is held by the countersink surface side opening edge 23) of the through hole 22 and does not operate.

  On the other hand, as shown in FIGS. 1 and 11, when the vehicle traveling speed changes suddenly due to a vehicle collision or the like and the acceleration acting on the sensor weight 11 exceeds a predetermined value, the vehicle sensor 1 Is moved from the rest position in the sensor holder 10, the sensor weight 11 pushes up (rotates) the sensor lever 7, and the claw 8 formed at the tip of the sensor lever 7 is attached to the webbing take-up drum. Bite between teeth 6 and 6. Then, the claw 8 of the sensor lever 7 of the vehicle sensor 1 is abutted against the elastic deformation piece 48 of the lever stopper 42 of the case 3 by the sensor weight 11. Then, the elastically deformable piece 48 of the lever stopper 42 is bent and deformed (elastically deformed), absorbs the impact at the time of collision with the claw 8 of the sensor lever 7, and the collision sound at the time of collision with the claw 8 of the sensor lever 7 Reduce. When the elastic deformation piece 48 of the lever stopper 42 is bent and deformed and abuts against the load receiving surface 51, the elastic deformation piece 48 of the lever stopper 42 cannot be bent and deformed, so that the rotation of the sensor lever 7 is prevented by the lever stopper 42. (See FIG. 10). As a result, the amount of meshing between the claw 8 of the sensor lever 7 and the tooth 6 of the gear 5 is limited within an appropriate range. Thereby, the vehicle sensor 1 can prevent the rotation of the gear 5 in the webbing pull-out direction, and can start the webbing take-up drum locking mechanism (webbing locking mechanism).

  In the operation state of the vehicle sensor 1 shown in FIG. 11, when the inertial force no longer acts on the sensor weight 11, the sensor lever 7 is a gear 5 that is urged to rotate in the webbing rewind direction by a spring not shown. It rotates in a direction that reduces the swing angle when pressed and rotates in a direction that decreases the swing angle by its own weight. As a result, the sensor weight 11 is pushed by the sensor lever 7 and returned to the rest position in the sensor holder 10.

(Effect of this embodiment)
According to the attachment structure of the vehicle sensor 1 for seat belt retractor according to the present embodiment, the elastically deformable piece 48 formed integrally with the lever stopper 42 of the case 3 applies an impact at the time of collision with the sensor lever 7 of the vehicle sensor 1. Since it can absorb, compared with the case where the lever stopper 42 of the case 3 is covered with an impact absorbing elastomer, the production efficiency of the case 3 can be increased, and the sheet using the case 3 and the vehicle sensor 1 can be improved. Noise during operation of the vehicle sensor 1 can be reduced without causing an increase in the price of the belt retractor.

  Further, according to the mounting structure of the seatbelt retractor vehicle sensor 1 according to the present embodiment, the claw 8 of the sensor lever 7 is equivalent to the gap 50 between the elastically deformable piece 48 of the lever stopper 42 and the load receiving surface 51. If the elastic deformation piece 48 comes into contact with the load receiving surface 51 and the elastic deformation piece 48 is prevented from being bent and deformed by the load receiving surface 51, the rotation of the sensor lever 7 is ensured by the lever stopper 42. It is possible to prevent the claw 8 of the sensor lever 7 from excessively biting between the teeth 6 and 6 of the gear 5.

(Modification 1)
FIG. 12 is a diagram illustrating a first modification of the lever stopper 42. As shown in FIG. 12A, the lever stopper 42 according to the first modification is formed so that the shape of the gap 50 (slit shape) viewed from the front side is a substantially “<” shape. The concave surface having a substantially “<” shape when viewed from the front side is a load receiving surface 51, and the convex surface 52 having a substantially “<” shape when viewed from the front side is a wall surface (load) on the gap 50 side of the elastic deformation piece 48. The surface facing the receiving surface 51). As a result, when the elastic deformation piece 48 is pressed against the load receiving surface 51 by the claw 8 of the sensor lever 7, the convex surface 52 of the elastic deformation piece 48 and the load receiving surface 51 are engaged (engaged with irregularities), and elastic deformation occurs. The piece 48 can be reliably prevented from moving along the load receiving surface 51 (see FIG. 12B). As a result, the bending stress generated on the base end (base) side of the cantilever-like elastic deformation piece 48 can be reduced, the durability of the vehicle sensor 1 can be increased, and the durability of the seat belt retractor can be increased. be able to. In this modification, the wall of the elastic deformation piece 48 on the gap 50 side is a convex surface so that the strength of the elastic deformation piece 48 does not decrease. In the present modification, the gap 50 of the lever stopper 42 is illustrated as having a substantially “<” shape when viewed from the front side of the lever stopper 42, but is not limited thereto. It is only necessary that the convex surface can engage with the load receiving surface 51 in a concave-convex manner.

(Modification 2)
13 to 14 are diagrams showing a second modification of the lever stopper 42. As shown in FIG. 13, the lever stopper 42 according to the second modification is formed with a cantilevered elastic deformation piece 53 having both ends in the width direction (the direction along the Y-axis) as base ends. The receiving surface 55 is formed so as to be positioned via a gap (slit) 54 in the deformation direction of the elastic deformation piece 53. The gap 54 of the lever stopper 42 is closed at both ends in the width direction of the lever stopper 42, is formed in parallel with the YZ plane, and penetrates the tip end side of the lever stopper 42 in the plate thickness direction (direction along the Z axis). It is formed to do. The load receiving surface 55 is formed in parallel with the YZ plane.

  In the lever stopper 42 according to this modification, when the elastic deformable piece 53 is bent and deformed (elastically deformed) by the claw 8 of the sensor lever 7, the elastic deformable piece 53 receives an impact at the time of collision with the claw 8 of the sensor lever 7. Absorbs by elastic deformation. Then, when the elastically deformable piece 53 bent and deformed by the claw 8 of the sensor lever 7 contacts the load receiving surface 55, the deformation of the elastically deformable piece 53 is blocked by the load receiving surface 55 (see FIG. 14).

  Even when the lever stopper 42 of this modification is replaced with the lever stopper 42 of FIG. 9 and the mounting portion structure of the seat belt retractor vehicle sensor 1 is configured, the same effect can be obtained. Note that the technical idea of Modification 1 may be applied to this modification, and the elastically deformable elastic piece 53 and the load receiving surface 5 may be engaged with each other in an uneven manner.

[Second Embodiment]
FIG. 15 is a diagram showing a second embodiment of the present invention. FIG. 15A is a view showing a state where the claw 8 of the sensor lever 7 and the lever stopper 42 are separated (state before a collision). FIG. 15B is a diagram illustrating a state after the claw 8 of the sensor lever 7 collides with the tip of the lever stopper 42.

  The attachment structure of the seatbelt retractor vehicle sensor according to the present embodiment is such that an elastically deformable piece 60 that absorbs an impact at the time of a collision between the sensor lever 7 and the lever stopper 42 is formed integrally with the claw 8 of the sensor lever 7. This is different from the attachment structure of the vehicle sensor for the seat belt retractor according to the first embodiment.

  That is, in the mounting structure of the seat belt retractor vehicle sensor according to the present embodiment, the sensor lever 7 is integrally formed with an elastic deformation piece 60 that elastically deforms and absorbs an impact at the time of collision with the lever stopper 42. The elastic deformation piece 60 constitutes a part of the claw 8.

  In addition, a load receiving surface 62 is integrally formed on the claw 8 of the sensor lever 7 so as to be positioned via the gap 61 in the deformation direction of the elastic deformation piece 60. The load receiving surface 62 prevents deformation of the elastic deformation piece 60 when the elastic deformation piece 60 elastically deformed by the gap 61 by the lever stopper 42 contacts. The gap 61 extends from the upper end surface 63 of the claw 8 toward the base end side (root side) of the claw 8 (extends diagonally to the left in FIG. 15) and is orthogonal to the XZ plane. The claw 8 is divided into an elastic deformation piece 60 and a load receiving portion 64 other than the elastic deformation piece 60. The load receiving portion 64 of the claw 8 has rigidity that is not easily deformed compared to the elastic deformation piece 60, and when the claw 8 bites between the teeth 6 and 6 of the gear 5, the lever stopper In cooperation with 42, the rotation of the gear 5 in the webbing pull-out direction can be reliably stopped (see FIG. 1).

  According to the attachment structure of the seat belt retractor vehicle sensor according to the present embodiment, the same effect as the attachment structure of the seat belt retractor vehicle sensor according to the first embodiment can be obtained.

  That is, according to the mounting structure of the vehicle sensor for seat belt retractor according to the present embodiment, the elastic deformation piece 60 formed integrally with the claw 8 of the sensor lever 7 of the vehicle sensor 1 collides with the lever stopper 42 of the case 3. Since the impact at the time can be absorbed, the production efficiency of the vehicle sensor 1 can be increased as compared with the case where the claws 8 of the sensor lever 7 are covered with the impact absorbing elastomer. Thus, noise during operation of the vehicle sensor 1 can be reduced without causing an increase in the price of the seat belt retractor using the vehicle 3.

  Further, according to the mounting structure of the vehicle sensor for the seat belt retractor according to the present embodiment, the lever of the case 3 is equivalent to the gap 61 between the elastic deformation piece 60 of the claw 8 of the sensor lever 7 and the load receiving surface 62. When the elastic deformation piece 60 is brought into contact with the load receiving surface 62 and is deformed by the stopper 42, the elastic deformation piece 60 is prevented from being deformed by the load receiving surface 62. Thus, the pawl 8 of the sensor lever 7 can be prevented from excessive biting between the teeth 6 and 6 of the gear 5.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle sensor, 3 ... Case, 5 ... Gear, 6 ... Teeth, 7 ... Sensor lever, 8 ... Claw, 10 ... Sensor holder, 11 ... Sensor weight, 42 ... Lever stopper, 48, 53, 60 ... elastic deformation piece, 50, 54, 61 ... gap, 51, 55, 62 ... load receiving surface, 52 ... convex surface

Claims (1)

When the sensor weight housed in the sensor holder moves in the sensor holder due to inertia, the sensor weight rotates the sensor lever made of synthetic resin and pushes it up, and the claw of the sensor lever is attached to the webbing take-up drum. A vehicle sensor for a seat belt retractor adapted to bite between the teeth of the gear and prevent rotation of the gear in the webbing pull-out direction;
A case made of a synthetic resin that rotatably supports the webbing take-up drum and has the vehicle sensor for the seat belt retractor attached thereto,
In the mounting structure of the vehicle sensor for the seat belt retractor provided with
When the sensor weight pushes up the sensor lever, the case abuts against the claw of the sensor lever to prevent the rotation of the sensor lever, and the claw of the sensor lever bites between the teeth too much. The lever stopper that prevents it from being formed integrally,
The lever stopper is
An elastic deformation piece that abuts on the claw of the sensor lever and elastically deforms and absorbs an impact at the time of collision with the claw of the sensor lever;
A load receiving surface that is located through a gap in the deformation direction of the elastic deformation piece, abuts on the elastic deformation piece elastically deformed by the claw of the sensor lever, and prevents deformation of the elastic deformation piece; Is formed as one,
The load receiving surface is a concave surface, the side corresponding to the load receiving surface of the elastic deformation piece is a convex surface, and the elastic deformation piece elastically deformed by a claw of the sensor lever contacts the load receiving surface. Then, the convex surface and the load receiving surface are adapted to engage with the concave and convex portions,
A mounting structure for a vehicle sensor for a seat belt retractor.

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