JP5755002B2 - Vehicle sensor for seat belt retractor - Google Patents

Description

The present invention relates to a vehicle sensor for a seat belt retractor equipped 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. 11 shows a vehicle sensor (vehicle sensor for seat belt retractor) 100 attached to the seat belt retractor.

As shown in FIG. 11, the vehicle sensor 100 is configured such that the sensor weight (metal spherical mass) 101 is rested in the sensor holder 102 when the vehicle is in a normal state (when the vehicle is stopped or when there is no sudden speed change). It is held in the position (sensor weight holding hole) 103 and does not operate.

On the other hand, as shown in FIG. 12, the vehicle sensor 100 is configured such that when the vehicle traveling speed changes suddenly due to a vehicle collision or the like, and the acceleration acting on the sensor weight 101 becomes a predetermined value or more, The claw 1 formed at the tip of the sensor lever 104 is moved from the repose position 103 in the sensor 102 to a position where it collides with the side wall surface 102a in the sensor holder 102, and the sensor weight 101 pushes up (rotates) the sensor lever 104.
05 is inserted between the teeth 107 of the gear 106 attached to the webbing take-up drum. At this time (when the vehicle sensor is activated), the sensor lever 1 of the vehicle sensor 100
04, when the webbing is pulled in the pull-out direction and further rotated by the gear 106 attached to the webbing take-up drum, it is pressed against the lever stopper 110 of the case 108 of the seat belt retractor to which the vehicle sensor 100 is attached, Deformation of the sensor lever 104 is prevented by the lever stopper 110. As a result, the vehicle sensor 100 can lock the rotation of the gear 106 in the webbing pull-out direction and can start the webbing take-up drum lock (webbing lock).

However, in recent years, the quietness of the interior of an automobile has progressed, and the collision noise between the sensor weight 101 and the side wall surface 102a of the sensor holder 102 during the operation of the vehicle sensor 100 has become easier to be detected by the seat belt wearer. Reduction of the collision sound between the sensor weight 101 and the side wall surface 102a of the sensor holder 102 during the operation of the sensor 100 is an issue.

In order to solve such a problem, as disclosed in Patent Document 2, the surface of the sensor weight 101 is covered with an elastomer, and an impact at the time of collision between the sensor weight 101 and the side wall surface 102a of the sensor holder 102 is applied. It is conceivable to reduce noise during operation of the vehicle sensor 100 by relaxing with an elastomer.

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

However, when the sensor weight 101 is coated with the elastomer, the number of manufacturing steps of the vehicle sensor 100 is increased by the process of coating the sensor weight 101 with the elastomer, resulting in a decrease in the production efficiency of the vehicle sensor 100 and the vehicle. Sensor 100
A new problem arises that leads to a rise in product prices.

Accordingly, an object of the present invention is to reduce noise during operation of the vehicle sensor without increasing the number of manufacturing steps of the vehicle sensor.

As shown in FIGS. 1 to 10, the vehicle sensor 1 for a seat belt retractor according to the invention of claim 1 includes a spherical metal sensor weight 11 housed in a sensor weight housing recess 12 of a synthetic resin sensor holder 10. Due to inertia, the sensor weight accommodating recess 12 can move from a rest position 23 to a position where it collides with the side wall surface 25 of the sensor weight accommodating recess 12. When the sensor lever 7 that is rotatably supported by the sensor holder 10 and is placed on the sensor weight 11 is rotated by the sensor weight 11 that moves in the sensor weight housing recess 12, the sensor The claw 8 of the lever 7 bites between the teeth 6 and 6 of the gear 5 attached to the webbing take-up drum to prevent the gear 5 from rotating in the webbing pull-out direction. In the present invention, the side wall surface 25 of the sensor weight housing recess 12 is formed so as to be concentric with the sensor weight 11 housed in the repose position 23 in the sensor weight housing recess 12. Further, the side wall surface 25 of the sensor weight housing recess 12 protrudes inward from the sensor weight housing recess 12 to elastically contact the sensor weight 11 and bend and deform by the sensor weight 11. A cantilever-like elastic deformation piece 50 is integrally formed along the circumferential direction. The elastic deformable piece 50 absorbs an impact when the sensor weight 11 collides with the side wall surface 25 by elastic deformation, and reaches a position where the sensor weight abuts on the side wall surface. When it is bent and deformed, it is housed in a housing groove formed on the side wall surface .

The vehicle sensor 1 for a seat belt retractor according to the invention of claim 2 is characterized by the elastic deformation piece 50 in the invention of claim 1. That is, as shown in FIGS. 5C and 10A, the elastic deformation piece 50 is another elastic deformation piece whose tip 50b is adjacent when viewed along the circumferential direction of the side wall surface 25. 50 is located on the base end 50a.

A vehicle sensor 1 for a seat belt retractor according to the invention of claim 3 is characterized by the elastic deformation piece 50 in the invention of claim 1. In other words, the elastic deformation piece 50 has a distal end 50b and a base end 50a of another elastic deformation piece 50 adjacent to the side wall surface 25.
It is formed so that it may overlap along the circumferential direction.

According to the present invention, the elastic deformation piece integrally formed on the side wall surface of the sensor holder is elastically deformed by the sensor weight, so that the impact when the sensor weight collides with the side wall surface is absorbed by the elastic deformation piece. Therefore, compared with the case where the surface of the sensor weight is coated with an elastomer, the number of manufacturing steps of the vehicle sensor can be reduced, and the price of the vehicle sensor and the seat belt retractor including the vehicle sensor is increased. Therefore, noise during operation of the vehicle sensor can be reduced.

1 is a partial cross-sectional view of a seat belt retractor showing a mounting structure of a vehicle sensor for a seat belt retractor according to an 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. 5A is a plan view of the sensor holder, FIG. 5B is a cross-sectional view taken along line A1-A1 of FIG. 5A, and FIG. 5C is FIG. It is a figure which expands and shows a part (elastic deformation piece) of (a). 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. FIG. 9 (a) is a plan view showing the relationship between the sensor weight and the elastically deformed piece during normal operation of the vehicle (when stopped or when there is no sudden speed change), and FIG. 9 (b) is a plan view of FIG. It is a top view which shows the relationship between the sensor weight in 1) and an elastic deformation piece. It is a figure which shows the modification of an elastic deformation piece, and each of Fig.10 (a)-(d) is a figure corresponding to FIG.5 (c). 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.

(Outline of vehicle sensor and its mounting structure)
FIG. 1 is a view for explaining a seat belt retractor vehicle sensor 1 (hereinafter abbreviated as a vehicle sensor) according to a first embodiment of the present invention and a mounting portion structure thereof.

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. Of these, FIG. 2 is a front view of the vehicle sensor 1 during normal operation of the vehicle (when stopped or when there is no sudden speed change).
FIG. 2A is an assembly state diagram of the vehicle sensor 1, and 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.
FIG. 3A is a longitudinal sectional view of the vehicle sensor 1 in an assembled state, and FIG. 3B is a longitudinal sectional view of the vehicle sensor 1 when disassembled.

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 (in the direction along the Z axis), and both side surfaces 13 on one end side of the sensor lever 7.
A pair of support legs 17 and 18 that rotatably support the support shafts 15 and 16 projecting from 14,
(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 sensor weight housing recess 12
The counterbore side opening edge 23 of the through hole 22 formed in the sensor hole 11 holds the sensor weight 11 in the center of the sensor weight receiving recess 12 until the inertial force acting on the sensor weight 11 becomes a predetermined value or more. It is a resting position. 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 tapered side 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 (a direction perpendicular to the bottom surface 20). It is connected to the bottom surface 20 via a shaped corner surface 26. The inner 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 side wall surface 25.

The side wall surface 25 is formed so that the shape in plan view is a concentric circle with the bottom surface 20, and is formed so that a gap with an equal interval is formed between the sensor weight 11 held in 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 weight housing recess 12 by the gap. Then, the side wall surface 25, the elastic deformation piece 50 which projects cantilevered inwardly of the sensor-weight housing recess 12 is formed with a plurality along a circumferential direction of the side wall surface 25.

The elastic deformation piece 50 has a substantially triangular shape in which the thickness in plan view gradually decreases from the base end 50 a toward the tip end 50 b (see FIGS. 5A and 5C in particular), and is cut out from the side wall surface 25. Thus, it is formed along the depth direction (Z-axis direction) of the sensor weight housing recess 12 (FIG. 5 (
b)). In addition, the elastic deformation piece 50 is in contact with the sensor weight 11 moving in the sensor weight housing recess 12, so that when viewed along the circumferential direction of the side wall surface 25, the tip 50 b is adjacent to the other. It is formed so as to be positioned on the base end 50a of the elastic deformation piece 50 (see FIGS. 5A, 5C, and 6A). The elastic deformation piece 50 is integrally formed as a part of the sensor holder 10 when the sensor holder 10 is injection molded.

Such an elastic deformation piece 50 is easily bent and deformed from the base end 50a toward the front end 50b, and elastically deforms the impact of the collision between the sensor weight 11 and the side wall surface 25 (
Absorption is performed by bending deformation (see FIGS. 6A and 9B).

When the sensor weight 11 is bent and deformed to a position where it abuts against the side wall surface 25, the elastic deformation piece 50 is accommodated in an accommodation groove 51 formed in the side wall surface 25, and the elastic deformation piece 50 on the side that abuts against the sensor weight 11. The surface 50c constitutes a part of the side wall surface 25 (FIG. 5C
)reference).

In the present embodiment, the elastic deformation piece 50 is formed from the upper surface 25 of the sensor holder 10 to the boundary position between the side wall surface 25 and the corner surface 26. However, the elastic deformation piece 50 is elastically deformed by the sensor weight 11 and becomes the sensor weight. 11 may be formed from the upper surface 24 of the sensor holder 10 to the middle of the side wall surface 25 as long as the impact of the collision between 11 and the side wall surface 25 can be absorbed.

The corner surface 26 is a substantially tapered curved surface 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, 18
When the support shafts 15 and 16 of the sensor lever 7 are fitted into the shaft holes 27 and 28, the support shafts 15 and 16 of the sensor lever 7 can be bent and deformed in directions away from each other. 2
After being fitted to 7, 28, the original posture is elastically restored (see FIG. 7). As a result, the support shafts 15 and 16 of the sensor lever 7 are connected to the shaft holes 27 and 28 of the pair of support legs 17 and 18.
Without swinging out, the shaft holes 27 and 28 of the pair of support legs 17 and 18 are supported so as to be swingable. 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. One support leg 1
8 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 simply moved along the inclined surface 30 (the other support leg It is devised so that the support shafts 15 and 16 of the sensor lever 7 and the shaft holes 27 and 28 can be easily engaged with each other by simply being pushed between them. 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 shaft 1
5 and 16 are 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. A sensor weight housing surface (concave surface) 40 having a substantially frustoconical shape is formed on the lower surface side of the sensor weight holder 38, and the sensor weight housing surface 4
0 comes into contact with the surface of the sensor weight 11 (see FIGS. 3 and 6). Also,
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 has a width dimension smaller than the width dimension of the arm part 41 connecting the sensor weight presser 38 and the support shafts 15 and 16.
It is formed in a tongue shape (in particular, see FIGS. 7A to 7C).

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 is provided with the sensor weight 1
1 is prevented from slipping out of the gap between the upper surface 24 of the sensor holder 10 and the sensor lever 7 (
(See FIG. 6).

(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.

(Vehicle sensor operation)
As shown in FIGS. 3 (a) and 9 (a), the vehicle sensor 1 is configured so that the sensor weight 11 is rested in the sensor holder 10 when the vehicle is in a normal state (during a stop or when there is no sudden speed change). It is held at the position (the through hole 22 that functions as a sensor weight holding hole, and in particular, the countersink surface side opening edge 23 of the through hole 22) and does not operate.

On the other hand, as shown in FIG. 1, FIG. 6A and FIG. 9B, the vehicle sensor 1 has a vehicle travel speed that suddenly changes due to a vehicle collision or the like, and the acceleration acting on the sensor weight 11 is a predetermined value. If it becomes above, the sensor weight 11 will move from the repose position 23 in the sensor weight accommodation recessed part 12 of the sensor holder 10 by inertia, and while the sensor weight 11 pushes up (rotates) the sensor lever 7, it will be in the sensor weight accommodation recessed part 12. It moves toward the side wall surface 25. When the sensor weight 11 approaches the side wall surface 25, the elastic deformation piece 50 is moved to the sensor weight 11.
In elastic contact. Then, the sensor weight 11 moves until it collides with the side wall surface 25 while bending and deforming the elastic deformation piece 50. At this time, the kinetic energy of the sensor weight 11 is absorbed by the bending deformation (elastic deformation) of the elastic deformation piece 50, and the impact at the time of collision between the sensor weight 11 and the side wall surface 25 is alleviated. As a result, the collision sound between the sensor weight 11 and the side wall surface 25 of the sensor holder 10 is suppressed to a low level, and the operation sound of the vehicle sensor 1 is reduced.

When the sensor weight 11 moves to a position where it collides with the side wall surface 25, the sensor weight 11
The claw 8 of the sensor lever 7 lifted by the bite bites between the teeth 6 and 6 of the gear 5 attached to the webbing take-up drum, and the rotation of the gear in the webbing pull-out direction is blocked by the sensor lever 7. As a result, the vehicle sensor 1 can reliably prevent the gear 5 from rotating in the webbing pull-out direction, and the webbing take-up drum locking mechanism (webbing locking mechanism) can be started.

When the sensor lever 7 is bent and deformed by the force received from the gear 5, the lever stopper 42 of the case 3 contacts the sensor lever 7, and the bending deformation of the sensor lever 7 is suppressed by the lever stopper 42 of the case 3.

In the operating state of the vehicle sensor 1 shown in FIGS. 1, 6A and 9B,
When the inertial force no longer acts on the sensor weight 11, the sensor lever 7 is pressed by the gear 5 that is urged to rotate in the webbing rewind direction by a spring (not shown) and rotates in a direction that reduces the swing angle. Rotate in the direction to reduce 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 repose position 23 in the sensor holder 10 (
3 (a) and 9 (a)).

(Effect of this embodiment)
According to the seatbelt retractor vehicle sensor 1 according to the present embodiment, the elastically deformable piece 50 formed integrally with the side wall surface 25 of the sensor weight housing recess 12 absorbs the impact at the time of collision between the sensor weight 11 and the side wall surface 25. Therefore, the production efficiency of the vehicle sensor 1 can be increased as compared with the case where the sensor weight 11 is coated with an impact absorbing elastomer, and the vehicle sensor 1 and the seat belt retractor using the vehicle sensor 1 can be improved. Thus, noise during operation of the vehicle sensor 1 can be reduced without causing an increase in price.

(Modification example of elastic deformation piece)
FIG. 10 shows an elastically deformable piece 5 formed integrally with the side wall surface 25 of the sensor weight housing recess 12.
A modification of 0 is shown. 10A shows a first modification of the elastic deformation piece 50, FIG. 10B shows a second modification of the elastic deformation piece 50, and FIG. 10C shows the elastic deformation piece 5.
FIG. 10 is a diagram showing a third modification example of 0, and FIG. 10D is a diagram showing a fourth modification example of the elastic deformation piece 50.

The elastic deformable piece 50 shown in FIG. 5 is formed so that the surface 50c on the side in contact with the sensor weight 11 becomes concave toward the inside of the sensor weight housing recess 12 (see FIG. 9B).
. However, the elastic deformation piece 50 is not limited to the shape shown in FIG. 5, and as shown in FIG. 10A, the surface 50 c on the side in contact with the sensor weight 11 has a convex surface toward the inside of the sensor weight housing recess 12. It may be formed in such a way (see FIG. 9B). In addition, FIG.
When the sensor weight 11 is bent and deformed to a position where the sensor weight 11 abuts against the side wall surface 25, the elastic deformation piece 50 according to a) is accommodated in the accommodation groove 51 formed in the side wall surface 25 and abuts against the sensor weight 11. The side surface 50c constitutes a part of the side wall surface 25 (FIG. 9 (
b)).

The elastic deformation piece 50 shown in FIGS. 5 and 10A has a base end 50a in a plan view.
The wall thickness gradually decreases from the side toward the tip 50b and the tip 50b is sharp. However, as shown in FIGS. 10B and 10C, the elastic deformation piece 50 is formed so as to have substantially the same thickness from the proximal end side 50a toward the distal end 50b side, and the distal end 50b is formed. It is rounded with a smooth curved surface. The elastic deformation piece 50 shown in FIG. 10B corresponds to the modification of the elastic deformation piece 50 shown in FIG. 5C, and the elastic deformation piece 50 shown in FIG. This corresponds to the modification of the elastic deformation piece 50 shown in b). Then, when the elastic deformation piece 50 according to FIGS. 10B and 10C is bent and deformed to a position where the sensor weight 11 contacts the side wall surface 25,
A surface 50c that is accommodated in an accommodation groove 51 formed on the side wall surface 25 and that abuts on the sensor weight 11 constitutes a part of the side wall surface 25 (see FIG. 9B).

Further, the elastic deformation piece 50 shown in FIG. 10 (d) has a shape in which a part of the side wall surface 25 is cut and raised, and the sensor weight support portion 52 is supported by the cantilever-like elastic deformation portion 53. It is configured. The surface 50 of the sensor weight support portion 52 that contacts the sensor weight 11
c is formed in the same curvature as the side wall surface 25, and when the whole elastic deformation piece 50 is pushed into the accommodation groove 51 by the sensor weight 11, it becomes the same surface as the side wall surface 25 (FIG. 9B).
reference).

(Other variations)
5A and 5C, the distal end 50 b of the elastic deformation piece 50 and the base end 50 a of another elastic deformation piece 50 adjacent to each other are positioned so as to overlap in the circumferential direction of the side wall surface 25. However, the circumferential position between the distal end 50b of the elastic deformable piece 50 and the base end 50a of another elastic deformable piece 50 adjacent to the elastic deformable piece 50 is not limited to the configuration shown in FIGS. The tip 50 of the piece 50
The base end 50 a of another elastic deformation piece 50 adjacent to b may overlap along the circumferential direction of the side wall surface 25. If it does in this way, the elastic deformation piece 50 shown to Fig.5 (a), (c).
Thus, an improvement in the impact absorption effect can be expected as compared with the case where the impact at the time of collision between the sensor weight 11 and the side wall surface 25 is absorbed. As long as the impact at the time of collision between the sensor weight 11 and the side wall surface 25 can be absorbed by the elastic deformation (bending deformation) of the elastic deformation piece 50, as shown in FIGS. 10B and 10C, the elastic deformation piece The distal end 50b of 50 and the base end 50a of the other elastic deformation piece 50 adjacent to each other may be displaced along the circumferential direction of the side wall surface 25 (not overlapped).

In the above-described embodiment and the above-described modifications, the elastic deformation piece 50 is integrally formed when the sensor holder 10 is injection-molded. However, the vehicle sensor 1 is compared with the case where the sensor weight 11 is covered with an elastomer. As long as the price of the elastic deformation piece 50 can be reduced, the elastic deformable piece 50 may be cut from the side wall surface 25 of the sensor holder 10 with a blade.

1 ... vehicle sensor, 5 ... gear, 6 ... tooth, 7 ... sensor lever, 8 ... claw, 10
... Sensor holder, 11 ... Sensor weight, 12 ... Sensor weight receiving recess, 23 ...
Opening edge (rest position) of the countersink surface, 25 ... side wall surface, 50 ... elastic deformation piece, 50a ... base end, 50b ... tip

Claims (3)

The spherical metal sensor weight housed in the sensor weight housing recess of the synthetic resin sensor holder can move from the rest position in the sensor weight housing recess to a position where it collides with the side wall surface of the sensor weight housing recess due to inertia. And
When the sensor lever that is rotatably supported by the sensor holder and is placed on the sensor weight is rotated by the sensor weight that moves in the sensor weight housing recess,
The claw of the sensor lever bites between the teeth of the gear attached to the webbing take-up drum to prevent the gear from rotating in the webbing pull-out direction.
A vehicle sensor for a seat belt retractor,
The side wall surface of the sensor weight housing recess is formed so as to be concentrically positioned with the sensor weight housed in the repose position in the sensor weight housing recess,
A plurality of cantilever-like elastic deformations projecting inwardly of the sensor weight housing recess to elastically contact the sensor weight and bend and deform by the sensor weight on the side wall surface of the sensor weight housing recess The piece is integrally formed along the circumferential direction,
The elastic deformation piece absorbs an elastic shock when the sensor weight collides with the side wall surface, and when the sensor weight is bent and deformed to a position where the sensor weight contacts the side wall surface. , Received in a receiving groove formed in the side wall surface,
A vehicle sensor for a seat belt retractor. When viewed along the circumferential direction of the side wall surface, the elastic deformation piece is configured so that its tip is located on the base end of another elastic deformation piece adjacent thereto,
The vehicle sensor for a seat belt retractor according to claim 1. The elastic deformation piece is formed so that a distal end thereof and a base end of another elastic deformation piece adjacent to each other overlap along a circumferential direction of the side wall surface.
The vehicle sensor for a seat belt retractor according to claim 1.

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