JP2013006547A - Vehicle sensor for seat belt retractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further reduce the noise when activating a vehicle sensor, while reducing the price of the vehicle sensor and a seat belt retractor using the same.SOLUTION: Upon action of inertia force on a sensor weight 12, the sensor weight 12 as it swings with its contact position P with the tip end of a support pole 11 as a fulcrum for a change in posture, a sensor lever 7 is caused to rotate by the sensor weight 12 to be pushed up, with the claw 8 of the sensor lever 7 being caught between the teeth 6, 6 of a gear 5 mounted on a webbing winding drum, thus the rotation of the gear 5 in the webbing drawing out direction is prevented. The sensor weight 12 is supported by the tip end of the support pole 11 so that it can swing the sensor lever 7 without colliding with a sensor holder 10. As a result, there is no colliding noise generated between the sensor weight 12 and sensor holder 10.

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. 12 shows a vehicle sensor 100 mounted on a case 108 of a seat belt retractor.
It is a figure which shows the vehicle sensor for seatbelt retractors.

As shown in FIG. 12, the vehicle sensor 100 is configured so that the spherical sensor weight 101 is in a rest position (sensor weight holding hole) in the sensor holder 102 when the vehicle is in a normal state (during a stop or when there is no sudden speed change). 103) and will not operate.

On the other hand, as shown in FIG. 13, the vehicle sensor 100 detects that the sensor weight 101 is detected by inertia when the vehicle traveling speed changes abruptly due to a vehicle collision or the like and the acceleration acting on the sensor weight 101 exceeds a predetermined value. The sensor weight 101 moves from the repose position in the holder 102, and the sensor weight 101 pushes up (rotates) the sensor lever 104, and the sensor lever 1
The nail | claw 105 formed in the front-end | tip of 04 is made to bite between the teeth 107 of the gearwheel 106 attached to the webbing take-up drum. 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 is rotated in the direction of biting between 107 and 107.
Is prevented by. 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 sound between the sensor weight 101 and the sensor holder 102 when the vehicle sensor 100 is operating has become more easily detected by the seat belt wearer. Sensor weight 101
Reducing the collision noise between the sensor holder 102 and the sensor holder 102 is an issue.

In order to solve such problems, the technology disclosed in Patent Document 2 is applied to cover the sensor weight 101 with an elastomer, and the impact at the time of collision between the sensor weight 101 and the sensor holder 102 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, even if the sensor weight 101 is covered with an elastomer, the sensor weight 1
Since 01 and the sensor holder 102 collide with each other, noise during operation of the vehicle sensor 100 could not be sufficiently reduced.

When the sensor weight 101 is covered with an elastomer, the vehicle sensor 10
The manufacturing man-hour of 0 increases 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 price of the vehicle sensor 100 and the seat belt retractor using the vehicle sensor 100. It creates a new problem that leads to soaring.

Therefore, an object of the present invention is to further reduce the noise during operation of the vehicle sensor and to reduce the price of the vehicle sensor and the seat belt retractor using the vehicle sensor.

As shown in FIGS. 1 to 11, the invention of claim 1 includes a synthetic resin sensor lever 7 supported at one end side so as to be swingable on support leg portions 17 and 18 of a synthetic resin sensor holder 10. The sensor lever 7 is slidably mounted on the tip of the column 11 of the sensor holder 10 and the sensor lever 7.
The present invention relates to a vehicle sensor 1 for a seat belt retractor comprising a sensor weight 12 made of a synthetic resin that comes into contact with the lower surface of the vehicle. Further, the vehicle sensor 1 for seat belt retractor according to the present invention has an attitude in which an inertial force acts on the sensor weight 12, and the sensor weight 12 swings around a contact position P with the tip end of the column 11 as a fulcrum. The sensor lever 7 is rotated and pushed up by the sensor weight 12, and the claw 8 of the sensor lever 7 bites between the teeth 6 and 6 of the gear 5 attached to the webbing take-up drum. The gear 5 is prevented from rotating in the webbing pull-out direction.
The sensor weight 12 is supported at the tip of the column 11 so that the sensor lever 7 can be swung without colliding with the sensor holder 10.

As shown in FIGS. 1 to 11, the invention of claim 2 relates to the vehicle sensor 1 for seat belt retractor according to the invention of claim 1, and has the following characteristic points. That is, the support column 11 is a rod-shaped body having a circular outer edge shape of the distal end surface 45 when viewed in plan. Further, the sensor weight 12 is formed with a column accommodation hole 41 for accommodating the column 11. Further, the column accommodation hole 41 is a ceiling surface 46 that is placed on the distal end surface 45 of the column 11 and has a circular shape when viewed from above, and from the ceiling surface 46 to the base end side of the column 11. And a tapered surface 47 whose hole diameter increases as it goes. When the opening angle of the tapered surface 47 is θ1 and the maximum swing angle of the sensor weight 12 is θ2, θ1 / 2> θ2. Further, the center axis L12 of the sensor weight 12 is connected to the column 1
The sensor weight 1 is placed on the front end surface 45 of the column 11 so as to coincide with the central axis L11 of the column 1.
When the second ceiling surface 46 is placed, the center of gravity G of the sensor weight 12 is positioned on the central axis L11 of the column 11.

According to the present invention, the sensor weight can be swung without the sensor weight colliding with the sensor holder, and the collision weight between the sensor weight and the sensor holder is not generated. Compared with the conventional example in which the sensor holder collides, noise during operation can be further reduced.

Further, according to the present invention, the sensor weight can be swung without colliding with the sensor holder, and no collision sound between the sensor weight and the sensor holder is generated. Therefore, the sensor weight is made of an impact absorbing elastomer. Compared to the conventional example of coating, the sensor weight can be increased by the amount that the sensor weight does not need to be coated with the impact absorbing elastomer, so that the product price of the vehicle sensor and the seat using the vehicle sensor can be increased. The price of the belt retractor can be reduced.

It is a partial sectional view of a seatbelt retractor using a vehicle sensor according to an embodiment of the present invention, and is a view showing a first operation state of the vehicle sensor. 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 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. . 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. It is a figure which shows a sensor weight. 6A is a plan view of the sensor weight, FIG. 6B is a side view of the sensor weight, and FIG. 6C is a sensor weight cut along the line A2-A2 in FIG. 6A. Sectional drawing and FIG.6 (d) are back views of a sensor weight. 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 retainer. 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 partial sectional view of a seatbelt retractor using a vehicle sensor according to an embodiment of the present invention, and is a view showing a state when the vehicle sensor is not operated. It is a partial sectional view of a seatbelt retractor using a vehicle sensor according to an embodiment of the present invention, and is a view showing a second operation state of the vehicle sensor. It is sectional drawing which expands and shows a part of seatbelt retractor using the vehicle sensor which concerns on embodiment of this invention, and the state which the nail | claw of the sensor lever of the vehicle sensor was clamped between the gear tooth and the lever stopper FIG. 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.

FIG. 1 is a view for explaining a vehicle sensor 1 for 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. 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 synthetic resin, a sensor weight 12 made of synthetic resin that can be swingably mounted on the tip of a column 11 of the sensor holder 10, and a sensor holder 10. And a sensor lever 7 made of synthetic resin that is mounted on the sensor weight 12 so that one end side thereof is swingable.

(Sensor holder for vehicle sensor)
As shown in FIGS. 2 to 5, the sensor holder 10 includes both side surfaces 1 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 3 and 14.
And a bottomed sensor weight housing recess 20 that opens upward, and a support column 11 that supports the sensor weight in a swingable manner (see FIGS. 7 to 8).

The sensor weight housing recess 20 is flat, is parallel to the XY direction, and has a bottom surface 21 formed so as to have a circular shape in plan view. The sensor weight housing recess 20 extends substantially obliquely upward from the outer edge of the bottom surface 21. A tapered corner surface 22 and a cylindrical wall surface 23 extending from the upper end of the corner surface 22 to the upper surface 24 of the sensor holder 10 are formed. At the center of the bottom surface 21 of the sensor weight housing recess 20, a round bar-like column 11 that supports the sensor weight 12 in a swingable manner is formed so as to stand along the Z-axis direction.

The column 11 constitutes a part of the sensor holder 10 and is formed up to the same height position (height position along the Z-axis direction) H as the position of the rotation center 28 of the sensor lever 7. The sensor weight housing recess 20 protrudes upward (beyond the upper surface of the sensor holder 10). The column 11 is formed to have substantially the same thickness (provided with a draft gradient required for molding) from the base end portion to the tip end portion, and the tip end surface is a bottom surface (XY plane). It is a parallel flat surface and a circular planar shape.

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 25 and 26 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 25 and 26, 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 5, 26, 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 25 and 26 of the pair of support legs 17 and 18.
Without swinging out, the shafts 25 and 26 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 27 on the upper end side and the side facing the other support leg portion 17, and the support shaft 16 of the sensor lever 7 is simply moved along the inclined surface 27 (the other support leg It is devised so that the support shafts 15 and 16 of the sensor lever 7 and the shaft holes 25 and 26 can be easily engaged with each other. Further, the shaft hole 26 of one support leg 18 and the shaft hole 25 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).

(Sensor weight of vehicle sensor)
As shown in FIGS. 3 and 6, the sensor weight 12 is shaped such that a sphere having a radius R1 is partially cut out, and the center of gravity G is formed on the central axis L12. .
The sensor weight 12 includes a lever support portion 37 on which the sensor lever 7 is placed, and a cylindrical portion 3 that extends from the outer peripheral end of the lever support portion 37 along the central axis L12 (along the −Z axis direction).
8, a chamfered portion 40 located at the lower end of the cylindrical portion 38, and a column accommodation hole 41 for accommodating the column 11.

The lever support portion 37 has a circular top surface portion 42 centered on the central axis L12 when viewed in plan.
And a plurality of ribs 43 extending radially from the outer peripheral edge of the top surface portion 42 at equal intervals. The surface of the top surface portion 42 and the surfaces of the plurality of ribs 43 constituting the lever support portion 37 are part of a spherical surface having a radius R1. A notch 44 extending from the lever support portion 37 to the cylindrical portion 38 is formed between the adjacent ribs 43. The sensor weight 12 provided with the notch 44 is in a state where the position of the center of gravity G is shifted downward along the central axis L12 and is placed on the column 11 as compared with the case where the notch 44 is not provided. The posture is stable. Such a lever support portion 37 comes into contact with the lower surface of the sensor lever 7 (sensor weight accommodating surface 50).

The cylindrical portion 38 is a cylindrical surface having a radius R2 (R2 <R1) with the central axis L12 as the center, except for a portion notched by the notched portion 44.

The chamfered portion 40 is a ring-shaped curved surface that is a part of a spherical surface with a radius R1, or a ring-shaped inclined surface that is inscribed in a curved surface that is a part of a spherical surface with a radius R1.

The column accommodation hole 41 is a tapered hole that opens downward (−Z-axis direction),
The ceiling surface 46 is placed on the front end surface 45 of the support column 11, and the tapered surface 47 has a hole diameter that increases downward from the ceiling surface 46. And this prop accommodation hole 4
Reference numeral 1 denotes a rotationally symmetric shape centered on the central axis L12, and the shape of the ceiling surface 46 in a plan view is a circular shape. The tapered surface 47 is formed so that θ1 / 2> θ2 when the opening angle is θ1 and the maximum swing angle of the sensor weight 12 is θ2 (see FIG. 11). As a result, the sensor weight 12 does not collide with the support 11 even when the vehicle sensor 1 is rotated to the maximum swing angle θ2 (FIG. 11).
reference).

Further, even if the sensor weight 12 formed in this way is rotated up to the maximum swing angle θ2 while being supported by the support 11, the inner surface of the sensor weight housing recess 20 of the sensor holder 10 (
The outer shape is such that it does not collide with the bottom surface 21, the corner surface 22, and the wall surface 23) (see FIG. 11).

(Sensor lever of vehicle sensor)
As shown in FIGS. 7 to 8, the sensor lever 7 is swingably fitted to the shaft holes 25 and 26 of the support legs 17 and 18 of the sensor holder 10 on both side surfaces 13 and 14 on one end side thereof. Support shaft 1
5 and 16 are formed (see FIGS. 2 and 4). Further, a sensor weight presser 48 that is placed on the sensor weight 12 supported by the support column 11 of the sensor holder 10 is formed on the other end side of the sensor lever 7. A sensor weight housing surface (concave surface) 50 having a substantially truncated cone shape that contacts the sensor weight 12 is formed on the lower surface side of the sensor weight retainer 48. The sensor weight housing surface 50 is a surface of the sensor weight 12 (lever). Support part 3
7) (refer to FIG. 3 and FIG. 11). 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 51 connecting the sensor weight presser 48 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. 52 is protrudingly formed. The rotation stopper 52 is provided with a sensor weight 1
2 is prevented 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 53 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 53 and the upper opening edge 54 of the sensor housing chamber 4, the claw 8 of the sensor lever 7 of the vehicle sensor 1 mounted in the sensor housing chamber 4 is connected to the teeth 6 and 6 of the gear 5. A window 55 is formed that allows it to protrude to a position that bites in between. The lever stopper 53 abuts on the claw 8 of the sensor lever 7 lifted by the sensor weight 12 rotated while being supported by the column 11 of the sensor holder 10 to prevent the rotation of the sensor lever 7, and the gear 5. Nail 8 between the teeth 6 and 6
It has come to regulate the biting of.

(Vehicle sensor operation)
As shown in FIGS. 3A and 9, the vehicle sensor 1 is configured so that the center axis L12 of the sensor weight 12 and the center axis of the support column 11 are used during normal operation of the vehicle (when stopped or when there is no sudden speed change). L
11 is positioned on the same axis or parallel to the sensor weight 12 so that the column 1
1 is supported.

On the other hand, as shown in FIGS. 1 and 10, the vehicle sensor 1 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 12 exceeds a predetermined value,
The sensor weight 12 is rotated with the contact position P between the outer edge of the front end surface 45 of the support column 11 and the ceiling surface 46 as a rotation fulcrum, and the sensor weight 11 pushes up (rotates) the sensor lever 7. The nail | claw 8 formed in the front-end | tip is bitten between the teeth 6 and 6 of the gearwheel 5 attached to the webbing take-up drum. When the claw 8 of the sensor lever 7 rotated by the sensor weight 12 is abutted against the lever stopper 53 of the case 3, the rotation of the sensor lever 7 is blocked by the lever stopper 53. 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. Thereafter, when a force in the webbing pull-out direction acts on the gear 5, the claw 8 of the sensor lever 7 is held between the teeth 6 of the gear 5 and the lever stopper 53 (see FIG. 11). 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 FIGS.
When the inertial force no longer acts on 2, 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.
It rotates in the direction to reduce the swing angle by its own weight. As a result, the sensor weight 12 is pushed by the sensor lever 7 and returned to the non-operating posture shown in FIGS.

(Effect of this embodiment)
According to the seatbelt retractor vehicle sensor 1 according to the present embodiment, the sensor lever 7 can be swung without the sensor weight 12 colliding with the sensor holder 10,
Compared with the conventional example in which the sensor weight 101 covered with the impact absorbing elastomer collides with the sensor holder 102 because the collision sound between the sensor weight 12 and the sensor holder 10 does not occur (see FIGS. 12 and 13). ), Noise during operation can be further reduced.

In addition, according to the seat belt retractor vehicle sensor 1 according to the present embodiment, the sensor weight 7 can be swung without the sensor weight 12 colliding with the sensor holder 10, and the collision between the sensor weight 12 and the sensor holder 10 can be achieved. Compared with the conventional example in which the sensor weight 101 is covered with an impact-absorbing elastomer because no sound is generated (see FIGS. 12 and 13).
The production efficiency of the vehicle sensor 1 can be increased by the amount that the sensor weight 12 does not need to be coated with the impact absorbing elastomer, and the product price of the vehicle sensor 1 and the seat belt retractor using the vehicle sensor 1 can be increased. The price can be reduced.

In addition, although the vehicle sensor 1 which concerns on this embodiment illustrated the aspect which forms the sensor weight 12 with a synthetic resin material, it is not restricted to this, You may make it form the sensor weight 12 with ceramics or a metal.

Further, in the vehicle sensor 1 according to the present embodiment, the support column 11 is formed in a solid round bar shape, but the present invention is not limited to this, and the support column 11 is hollow as long as the outer edge shape of the distal end surface 45 is circular. It may be a pipe shape.

1 ... vehicle sensor, 5 ... gear, 6 ... tooth, 7 ... sensor lever, 8 ... claw, 10
…… Sensor holder, 11 …… Support column, 12 …… Sensor weight, 17, 18 …… Support leg,
41... Supporting hole 45. Tip surface 46. Ceiling surface 47. Tapered surface L 11
L12: Center axis, P: Contact position, G: Center of gravity

Claims (2)

A synthetic resin sensor lever whose one end is swingably supported by a support leg of a synthetic resin sensor holder;
A sensor weight made of synthetic resin, which is placed so as to be able to swing at the tip of the support column of the sensor holder and is in contact with the lower surface of the sensor lever,
When an inertial force acts on the sensor weight and the sensor weight swings around the contact position with the tip of the support column and changes its posture, the sensor lever is rotated by the sensor weight and pushed up. The claw of the sensor lever bites between the teeth of the gear attached to the webbing take-up drum, and the rotation of the gear in the webbing pull-out direction is prevented.
The sensor weight is supported at the tip of the column so that the sensor lever can be swung without colliding with the sensor holder.
A vehicle sensor for a seat belt retractor. The support column is a rod-shaped body having a circular outer edge shape when viewed from the top,
The sensor weight has a column accommodation hole for accommodating the column,
The column accommodation hole is a ceiling surface that is placed on the tip end surface of the column and has a circular shape in plan view, and a taper in which the hole diameter increases from the ceiling surface toward the base end side of the column. And having a surface,
When the opening angle of the tapered surface is θ1, and the maximum swing angle of the sensor weight is θ2, θ1 / 2> θ2.
When the ceiling surface of the sensor weight is placed on the tip surface of the support so that the center axis of the sensor weight matches the center axis of the support, the center of gravity of the sensor weight is positioned on the center axis of the support. To
The vehicle sensor for a seat belt retractor according to claim 1.

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