WO2019039389A1

WO2019039389A1 - Seat belt device

Info

Publication number: WO2019039389A1
Application number: PCT/JP2018/030470
Authority: WO
Inventors: 克弘伊東; 岩太日端
Original assignee: オートリブディベロップメントエービー; 克弘伊東; 岩太日端
Priority date: 2017-08-25
Filing date: 2018-08-17
Publication date: 2019-02-28
Also published as: JP6964746B2; JP6802925B2; JPWO2019039389A1; JP2021035835A

Abstract

According to the present invention, a seat belt retractor (11) includes a rotation transmission mechanism (76) that transmits the rotation of an adjust gear (74) to a sensor housing (32) to swing the sensor housing (32) in the front-rear direction of a vehicle. The center of gravity (G) of a sensor-assembled body (39) when the sensor-assembled body (39), in which an inertial body (35) is placed on an inertial body supporting surface (33), is in a neutral position is at a position spaced apart from a vertical line (V1) passing through a shaft center (O) of a swing shaft (L1) of the sensor housing (32). Accordingly, the rotation by an angle determined according to the inclination angle of a seat back (16) is transmitted from the adjust gear (74) to the sensor housing (32) by means of the rotation transmission mechanism (76), the sensor-assembled body (39) is constantly rotated in a single direction by the center of gravity (G) to absorb rattling between components of the rotation transmission mechanism (76), and the inclination angle of the seat back (16) and the rotation angle of the sensor housing (32) are synchronized with high accuracy to improve the accuracy of an acceleration sensor (30).

Description

Seat belt device

The present invention relates to a seat belt device for protecting an occupant in a vehicle, and more particularly to a seat belt device in which a seat belt retractor is incorporated into a seat back of a reclining seat.

A seat belt device mounted on a vehicle is for restraining an occupant seated on a seat by a seat belt pulled out from a seat belt retractor to protect the occupant at the time of a vehicle collision or the like. When an acceleration larger than a predetermined value acts in the horizontal direction at the time of a vehicle collision or the like, the seat belt retractor detects this acceleration with the acceleration sensor and operates the locking mechanism of the seat belt, whereby the seat belt can not be pulled out. Make it As an inertial body used for an acceleration sensor, the thing using a ball and the thing using a self-supporting inertial body are known.

By the way, when the seat belt retractor equipped with this type of acceleration sensor is equipped on the seat back of a reclining type seat, the posture of the seat belt retractor changes depending on the reclining angle (tilt angle) of the seat back. Will not be able to properly detect the acceleration. Then, the seat belt apparatus equipped with the acceleration sensor which enabled it to be able to detect an acceleration appropriately irrespective of the reclining angle of a seat back is known (for example, refer patent document 1 and patent document 2).

The seat belt device described in Patent Document 1 and Patent Document 2 advances and retracts the cable by the length according to the inclination angle of the seat back to the connecting portion between the seat back support arm and the reclining rotary shaft provided protruding from the seat cushion. Arrange the cable advancing and retracting mechanism. Then, when the seat back tilts back and forth, control is performed so that the sensor reference line of the acceleration sensor is always directed in the vertical direction by the cable bridged between the cable advancing and retracting mechanism and the seat belt retractor, and the acceleration is achieved. It is properly detected.

Japanese Patent Laid-Open Publication 2000-79867 Japanese Patent Application Laid-Open No. 2000-52921

According to the seat belt device described in Patent Document 1 and Patent Document 2, a sensor having a pointed upper end in the substantially triangular rising piece engaging groove provided on the posture control rotor and expanding downward. The standup piece of the case engages with a slight amount of play to transmit the rotation of the attitude control rotor to the sensor case to control so that the sensor reference line of the acceleration sensor is always directed in the vertical direction. However, since the hysteresis at the time of reciprocation occurs due to backlash between the rising piece engagement groove and the rising piece during rotation of the sensor case, it is difficult to maintain the acceleration sensor horizontally, and the locking performance There was a problem of fluctuating.

The present invention has been made in view of the above-described problems, and an object thereof is to suppress hysteresis due to backlash between connecting parts that connect a cable advancing and retracting mechanism to an acceleration sensor of a seat belt retractor. It is an object of the present invention to provide a seat belt device capable of improving the accuracy of an acceleration sensor.

The above object of the present invention is achieved by the following constitution.
(1) A seat belt retractor which is attached to the seat back of a reclining seat and takes up the seat belt when necessary;
The seatback of the reclining seat is disposed at the connecting portion of the seat cushion, and has a cable for detecting a tilt angle when the seatback tilts in the longitudinal direction of the vehicle and transmitting the tilt angle to the seatbelt retractor. Cable advancing and retracting mechanism,
A seat belt device comprising
The cable advancing and retracting mechanism is
The cable advances or reverses in the longitudinal direction of the cable by a distance corresponding to the tilt angle of the seat back.
The seat belt retractor is
A retractor frame fixed to the seat back;
A spindle supported by the retractor frame for winding the seat belt;
An acceleration sensor attached to the retractor frame to detect an acceleration in a longitudinal direction of the vehicle;
A lock mechanism for locking the seat belt withdrawing operation according to the acceleration in the vehicle longitudinal direction detected by the acceleration sensor;
And a posture control mechanism for keeping the sensor reference surface of the acceleration sensor horizontal.
The acceleration sensor is
A sensor cover fixed to the retractor frame;
It has an inertial body that moves in the longitudinal direction of the vehicle when an acceleration equal to or greater than a predetermined value acts in the longitudinal direction of the vehicle, and a rocking axis along the lateral direction of the vehicle, and is held by the sensor cover. A sensor assembly having the sensor reference surface, and a sensor assembly including an operation member for operating the lock mechanism to the lock side in conjunction with movement of the inertia body in the longitudinal direction of the vehicle;
The attitude control mechanism
It has a rotation member which rotates an angle according to the distance of the advance or reverse movement of the cable by the cable advancing and retracting mechanism,
The seat belt retractor further comprises:
And a rotation transmission mechanism that transmits the rotation of the rotation member to the sensor housing to rock the sensor housing in the longitudinal direction of the vehicle,
The center of gravity of the sensor assembly in which the inertial body is placed on the sensor reference surface in the neutral position is located at a position deviated from the vertical line passing through the axial center of the swing axis of the sensor housing. Seat belt device characterized in that it is located.
(2) The rotating member and the sensor housing can be opposed to each other with a predetermined gap, and can be engaged with each other so that the sensor housing can follow the rotation of the rotating member in both directions. Joint and engaged parts respectively,
The seat belt device according to (1), wherein the center of gravity of the sensor assembly is set such that the engaging portion and the engaged portion are in constant contact with each other.
(3) The engaging portion of the rotating member is a pin,
The engaged portion of the sensor housing is a pair of arm portions positioned to sandwich the pin,
The seat belt apparatus according to (2), wherein the center of gravity of the sensor assembly is set such that the pin and the arm portion are in constant contact with each other.
(4) The sensor housing includes a pair of arm portions positioned to sandwich a pin provided on the rotating member,
The seat belt device according to (1), wherein the pin is elastically deformable so that the maximum outer diameter can be reduced, and is always in contact with both inner side surfaces of the pair of arms at the same time. .
(5) The retractor frame is fixed to the seatback at an inclination in the left-right direction of the vehicle with respect to a straight line extending in the up-down direction from the center in the left-right direction of the seatback.
The rotational axis of the rotating member and the oscillating shaft of the sensor housing have a predetermined angle with respect to the lateral direction of the vehicle such that the oscillating shaft of the sensor housing is installed in the horizontal direction with respect to the lateral direction of the vehicle A seat belt device according to any one of (1) to (3), characterized in that the seat belt device crosses.

In the present invention, "upper and lower" or "upper and lower direction" indicates the direction when the floor and ceiling are viewed from the center of the vehicle, and "left and right or left and right" means the vehicle width direction of the vehicle. Indicates
In addition, "horizontal" or "horizontal direction" includes horizontal (horizontal direction), and even if it changes slightly from the horizontal, it produces manufacturing errors or effects of the present invention when designing a product. It includes the range that can be done.

Also, “in the state of being placed in the neutral position” means the geometric center (or swing axis) of the inertial body (eg, ball) of the sensor assembly when the inertial body and the sensor assembly are at rest. And the sensor assembly that is stationary so that the vertical line extending in the direction of the force acting by gravity passes through the deepest part of the inertia body support surface (eg, near the center of the bottom of the inertia body support surface). It says the physical relationship of the body.

Furthermore, in the "inclination angle of the seat back in the longitudinal direction of the vehicle", the detection range of the inclination angle of the seat back is the state in which the seat back rises up to the extent that the occupant can sit down. It is set to be able to detect between the states. However, it is also possible to design the angle detection portion so that the angle detection is performed at all during the state in which the seatback is turned forward and the state in which the seatback is turned backward. It can be set arbitrarily according to.

In the following embodiments, "the inclination of the center of the seatback in the left-right direction with respect to the straight line extending in the vertical direction" is ± 15 in the left-right direction with respect to the straight line extending in the vertical direction. Although only those that are inclined are described, as long as they are rationally designed, settings can be made between 0 ° and ± 45 ° in the left and right directions, respectively.

In the seat belt device according to the present invention, the seat belt retractor transmits the rotation of the rotating member to the sensor housing and swings the sensor housing in the longitudinal direction of the vehicle such that the sensor reference surface is held in a horizontal state. Includes a rotation transmission mechanism. Further, the center of gravity of the sensor assembly in which the inertial body is placed on the sensor reference surface in the neutral position is located at a position deviated from the vertical line passing through the axial center of the swing axis of the sensor housing. .

Thereby, while transmitting rotation of an angle according to the inclination angle of the seat back from the rotation member to the sensor housing by the rotation transmission mechanism, the sensor assembly is always rotated in one direction by the rotational torque acting on the center of gravity of the sensor assembly. Backlash between parts of the rotation transmission mechanism. For this reason, regardless of the presence or absence and size of rattling, the occurrence of hysteresis of the sensor housing can be prevented, and the tilt angle of the seat back and the rotation angle of the sensor housing can be accurately synchronized. Therefore, the sensor reference surface can be accurately kept horizontal even at an arbitrary seatback inclination angle, and the accuracy of the acceleration sensor can be improved.

(A) is a side view of a reclining seat provided with a seat belt device according to a first embodiment of the present invention, (b) is a rear view of the left seat of the reclining seat, (c) is It is a rear view of the right seat of the reclining type seat. (A) is a cross-sectional view of the right side seat belt retractor mounted on the left side at a predetermined angle θ when viewed from the front side of the vehicle; (b) is on the right side for the left seat mounted at a predetermined angle θ FIG. 2 is a cross-sectional view of the seat belt retractor of FIG. It is a disassembled perspective view of the seat belt retractor. It is a disassembled perspective view of the acceleration sensor of the seat belt retractor, and a posture control mechanism. (A) is a perspective view which shows the assembly state of the same acceleration sensor and attitude | position control mechanism, (b) is the side view. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5 (b), showing a state where the seat belt retractor is attached to the right side at a predetermined angle θ. (A) is a perspective view which shows the structure of the sensor housing used for the seatbelt retractor for left seats, (b) is a perspective view which shows the structure of the sensor housing used for the seatbelt retractor for right seats. (A) is a side view showing that the seat belt retractor is attached to be inclined in the vehicle width direction (right direction), and (b) is a rotation track surface of the adjustment gear (rotation member) of the attitude control mechanism A diagram showing the movement locus of the pin of the adjustment gear from a direction perpendicular to (a plane inclined with respect to the vertical plane), and (c) is from a direction (horizontal direction) perpendicular to the rotation track surface (vertical plane) of the sensor housing (D) shows the movement trajectory of the pin of the adjustment gear, (d) shows the movement trajectory of the slit from the direction (horizontal direction) perpendicular to the rotation orbit surface (vertical surface) of the sensor housing, (e) shows (c) ) And (d) are composite diagrams of movement trajectories. (A) is a perspective view of a pulley of a posture control mechanism used for a seat belt retractor for a left seat, (b) is a front view thereof, (c) is an IXc-IXc arrow sectional view in (b), d) is a perspective view of a pulley of a posture control mechanism used for a seat belt retractor for a right seat, (e) is a front view thereof, and (f) is a cross-sectional view taken along line IXf-IXf of (e). It is a figure which shows the change of the radius [The radius r of the cable winding groove 73b of FIG.9 (c), (f)] from the rotation center of the cable winding groove of a pulley. It is sectional drawing which shows the state in which the clearance gap was provided between the pin of adjustment gear, and the slit of a sensor housing. It is sectional drawing which shows the gravity center of a sensor assembly body, and the positional relationship of a sensor assembly body and an adjustment gear (rotating member). In the side view showing the state of the seat belt retractor and the cable advancing and retracting mechanism for each inclination angle of the seat back, (a) is the state at the time of backward inclination 15 °, (b) is the state at the backward inclination 95 °, (C) shows the state at the time of 75 degrees of forward inclination. It is an exploded perspective view showing a cable advancing and retracting mechanism. It is a side view showing the state of the same cable advancing and retracting mechanism, (a) is a state when the seat back is turned backward 15 °, (b) is a state when the seat back is turned backward 95 °, (c) is a seat back Shows the state when advancing 75 °. It is sectional drawing which shows the state which the sensor assembly body rotated to 71.27 degrees anticlockwise. (A) is sectional drawing which shows the state which the sensor assembly | assembly body rotated 12.7 degrees clockwise, (b) is the XVII section enlarged view of (a). It is sectional drawing which shows the relationship of the sensor assembly body of 2nd Embodiment, and an adjustment gear (rotating member).

Hereinafter, each embodiment of a seat bell device concerning the present invention is described in detail based on a drawing.

First Embodiment
As shown in FIGS. 1 (a) to 1 (c), the seat belt device 10 of the first embodiment is attached to the seat back 16 of the reclining seat 15, and the seat belt retractor 11 takes up the seat belt 19 when necessary. Are disposed at the connecting portion 18 between the seat back 16 of the reclining seat 15 and the seat cushion 17 and advance and retract the cable 13 by a distance according to the inclination angle of the seat back 16 to tilt the cable 13 by tilting the seat back 16. And a cable advancing / retracting mechanism 80 for transmitting to the seat belt retractor 11 to restrain an occupant in the vehicle against the reclining seat 15. Usually, the cable 13 is covered by an exterior tube to be described later, and both ends of the exterior tube are fixed to the seat belt retractor 11 and the casing of the cable advancing and retracting mechanism 80 and the cable 13 accommodated inside is fixed to the exterior tube. Is designed to slide smoothly.

The seat belt retractor 11 tilts at an arbitrary angle in the front-rear direction of the vehicle according to the reclining angle of the seat back 16. In addition, in the width direction of the vehicle (vehicle left-right direction), in order to enable the seat belt 19 to be drawn out smoothly from the seat belt retractor 11, it is attached at different predetermined angles θ depending on the vehicle type and seat specifications. Here, the reference attachment posture of the seat belt retractor 11 is inclined at approximately 15 ° to the rear of the vehicle (15 ° backward), and is inclined at a predetermined angle θ (= 15 °) in the width direction of the vehicle , Is attached to the seat back 16. That is, as shown in FIG. 1 (b), in the case of the left seat, it is attached to the left side at a predetermined angle θ (= 15 °) as viewed from the rear side, as shown in FIG. 1 (c) In the case of the right seat, it is attached to the right side at a predetermined angle θ (= 15 °) as viewed from the rear side.

As shown in FIG. 2 and FIG. 3, the seat belt retractor 11 is fixed to the seat back 16 by tilting the center of the seat back 16 in the left and right direction with respect to a straight line extending vertically. A spindle 22 for rolling up the seat belt 19 is rotatably supported by the retractor frame 21.

A retractor spring 23 that rotationally biases the spindle 22 in the winding direction of the seat belt 19 is connected to one end side in the axial direction of the spindle 22, and the retractor spring 23 is accommodated in the cover 23a.

The steering wheel 25 which is one component of the lock mechanism 24 for locking the pulling-out operation of the seat belt 19 is detected at the other axial end of the spindle 22 and the acceleration in the front-rear direction acting on the vehicle is detected. An acceleration sensor 30, which operates the lock mechanism 24 according to acceleration, and a posture control mechanism 70, which keeps the sensor reference surface (an inertial body support surface 33 described later) of the acceleration sensor 30 horizontal regardless of the inclination angle of the seatback 16; Is provided.

The steering wheel 25 is coupled to the spindle 22 so as to rotate integrally with it, and has a plurality of engagements arranged on the outer circumferential surface at predetermined intervals in the circumferential direction to be engaged with an upper claw portion 36b of the first sensor lever 36 described later. It has an engaging claw 25 a and is accommodated inside the steering wheel cover 27. Further, the entire side surface on the other end side of the seat belt retractor 11 including the acceleration sensor 30 is covered by the retractor cover 29.

As shown in FIGS. 3 and 4, the acceleration sensor 30 has a sensor cover 31, a sensor housing 32, an iron ball 35 as an inertial body, and a second sensor lever 37 as an actuating member. There is. The sensor cover 31 is fixed to the outer side surface of the retractor frame 21 so as to tilt integrally with the seat back 16 in the longitudinal direction of the vehicle. The sensor housing 32 is swingably supported by the sensor cover 31 with respect to the sensor cover 31 centering on a swing axis L1 (see FIG. 6) along the vehicle left and right direction, and when the seat back 16 is tilted, the attitude control mechanism 70 By rotating the sensor cover 31 in the longitudinal direction of the vehicle, the inertial body support surface 33 as a sensor reference surface is held in a horizontal state in the longitudinal direction of the vehicle. The ball 35 is supported on the inertial body support surface 33 of the sensor housing 32 and displaced from the neutral position when acceleration in the vehicle longitudinal direction above a predetermined value acts. The second sensor lever 37 operates the lock mechanism 24 to the lock side interlockingly when the ball 35 is displaced in the longitudinal direction of the vehicle.

The sensor housing 32, the ball (inertial body) 35, and the second sensor lever (operating member) 37 constitute a sensor assembly 39 (see FIG. 11). As will be described in detail later, the center of gravity G in the state where the sensor assembly 39 mounting the ball 35 on the inertia body support surface 33 is in the neutral position is the axial center of the swing axis L1 of the sensor housing 32. The position is set out of the extension of the vertical line V1 passing O.

Specifically, as also shown in FIG. 6, a pair of

bosses

32a and 32b protruding from the outer surface of the sensor housing 32 are respectively fitted in the pair of

support holes

31a and 31b of the sensor cover 31. The rocking shaft L1 is configured by this, and the sensor housing 32 is rockable in the vehicle longitudinal direction about the rocking shaft L1. Further, as shown in FIG. 4, the pair of pivoting

projections

37a, 37b of the second sensor lever 37 are fitted in the

lever support holes

32e, 32f formed in the pair of

brackets

32c, 32d of the sensor housing 32, The two sensor levers 37 are rotatably supported by the sensor housing 32 in the longitudinal direction of the vehicle.

The sensor housing 32 is provided with an inertia body support surface 33 which is a concave concave bowl shape concave surface on the upper inner bottom surface, and the ball 35 is placed on the inertia body support surface 33. The ball 35, which is an inertial body, detects an acceleration acting on the vehicle (that is, the seat belt retractor 11) displaced from the neutral position when receiving an acceleration in the front-rear direction of the vehicle over a predetermined level. The state in which the inertial body support surface 33 is horizontal means that the reference surface of the inertial body support surface 33 (for example, the upper surface of the inertial body support surface 33) is horizontal.

As shown in FIG. 3, the first sensor lever 36 has a boss 36 a provided with a fitting hole at its base end, and an upper claw 36 b and a second sensor whose tip is in contact with the steering wheel 25. The lower claw portion 36c that abuts on the lever 37 is formed in a substantially Y shape. The first sensor lever 36 is disposed below the steering wheel 25, and the fitting hole of the boss portion 36 a is rotatably fitted to a support shaft (not shown) fixed to the retractor frame 21. . Then, the upper claw portion 36 b engages with the engagement claw 25 a of the steering wheel 25 by pivoting upward around the boss portion 36 a having the fitting hole, thereby restricting the rotation of the steering wheel 25. Therefore, the lock mechanism 24 is configured by the steering wheel 25 and the first sensor lever 36.

As shown in FIGS. 3 and 4, the second sensor lever 37 includes pivoting

projections

37a and 37b formed at the base end, a flange 37c formed on the tip end side and covering the upper surface of the ball 35, and And a rib 37d formed on the upper surface of the portion 37c. The rotation protrusions 37 a and 37 b are rotatably fitted in lever support holes 32 e and 32 f of the sensor housing 32. In the second sensor lever 37, the collar portion 37c contacts the upper side of the ball 35, and the lower claw portion 36c of the first sensor lever 36 contacts the upper surface of the rib 37d. Then, when the ball 35 is displaced from the neutral position by acceleration, it is pivoted upward to push the first sensor lever 36 upward through the lower claw portion 36c, and the upper claw portion 36b is engaged with the engagement claw 25a of the steering wheel 25. Engaging and locking the steering wheel 25. When the ball 35 is displaced, the first sensor lever 36 and the second sensor lever 37 rotate in opposite directions, and the positions of the pivot axes are set in opposite directions when viewed from the center of the ball 35. It is done.

Further, as shown in FIG. 4, the attitude control mechanism 70 for controlling the attitude of the sensor housing 32 in the front-rear direction includes a first pulley case 71 and a second pulley case 72 disposed inside the side plate of the retractor frame 21; A pulley (first pulley) 73 accommodated in an internal space formed by combining the first pulley case 71 and the second pulley case 72, a adjust gear 74, and a torsion spring for rotationally urging the pulley 73. 75 and a rotation transmission mechanism 76 (see FIG. 6) for transmitting the rotation of the adjustment gear 74 to the sensor housing 32 of the acceleration sensor 30.

The pulley 73 is rotatably supported by the first pulley case 71 and the second pulley case 72 around a support shaft 71 c provided in the first pulley case 71, and the cable advancing and retracting mechanism 80 advances and retracts the cable 13. The movement is converted into a rotational movement, and is rotated in the same direction as the tilting direction of the seat back 16 by an angle corresponding to the forward and backward movement of the cable 13. A cable winding groove 73b for winding the cable 13 is provided on the outer peripheral surface of the pulley 73, and one end (upper end) of the cable 13 is fixed to the pulley 73 via the end block 13a. The cable 13 is passed through the outer tube 13 b, and one end of the outer tube 13 b is fixed to the first pulley case 71 and the second pulley case 72.

The torsion spring 75 (see FIG. 3) rotationally biases the pulley 73 in the winding direction of the cable 13. The adjusting gear 74 is a rotating member that meshes with a gear 73 a formed on the side portion of the pulley 73 and synchronously rotates at the same rotation angle in the direction opposite to the tilting direction of the seat back 16. Then, as shown in FIG. 6, one axial projection 74 a is fitted into the support hole 71 a formed in the first pulley case 71, and the other axial projection 74 b whose tip is spherical is formed into the opening window of the first pulley case 71. The adjustment gear 74 is supported so as to be rotatable around the rotation axis L2 by being fitted to the spherical hole 32g of the end face of the boss 32b of the sensor housing 32 through 71b (see FIG. 4). In this case, by the engagement of the spherical hole 32g and the spherical axial projection 74b, the rotational axis L2 of the adjustment gear 74 and the oscillation axis L1 of the sensor housing 32 are at the center of the axial projection 74b in an arbitrary angle. Cross at one point.

The rotation transmission mechanism 76 transmits the rotation of the adjustment gear (rotating member) 74 to the sensor housing 32 and swings the sensor housing 32 to move the sensor reference line S1 of the acceleration sensor 30 (the ball 35 in the neutral position). A horizontal line perpendicular to the sensor reference line S1 holds the inertia body support surface 33 as a sensor reference plane horizontal by orienting a line perpendicular to the sensor reference plane through the center point in the vehicle longitudinal direction. is there. Such a rotation transmission mechanism 76 is a pin (engagement (engagement) which is formed on the adjusting gear 74 and the sensor housing 32 and is disposed at positions separated radially from the swing axis L1 and the rotation axis L2, respectively. Part) 74c and slit 32h are combined.

Here, the pin 74c is formed on the adjustment gear 74 side, and the slit 32h is formed on the sensor housing 32 side, but may be formed reversely. The slit 32 h is formed by a pair of arm portions (engaged portions) 32 i protruding downward to the side of the sensor housing 32. In this arm portion 32i, the slit 32h and the pin 74c can be engaged reliably, and moreover, it is necessary not to interfere with other portions. Therefore, a sensor housing 32L (32) used for the seat belt retractor for the left seat as shown in FIG. 7 (a) and a sensor housing used for the seat belt retractor for the right seat as shown in FIG. 7 (b) The shape of the arm portion 32i is slightly different from that of the 32R (32).

Such a seat belt retractor 11 has different reference mounting postures according to vehicle types and seat specifications. For example, the seat is inclined approximately 15 degrees to the rear of the vehicle and θ = 15 degrees in the width direction (left and right direction) of the vehicle. It is attached to the back 16. The seat belt retractor 11 can be attached at different inclination directions and angles in the vehicle width direction depending on the vehicle type and seat specification by making the inclination of the spindle 22 in the vehicle width direction coincide with the drawing direction of the seat belt 19 To make it possible.

Therefore, as shown in FIG. 6, by attaching the retractor frame 21 to the right side at a predetermined angle θ (= 15 °) and attaching it, the rotation track surface of the pulley 73 and the adjustment gear 74 of the attitude control mechanism 70 becomes a vertical surface. Conversely, although not shown, when the retractor frame 21 is attached to the left side at a predetermined angle θ, the rotation of the pulley 73 of the attitude control mechanism 70 and the adjustment gear 74 is performed. There are two mounting orientations in which the moving track surface is inclined leftward with respect to the vertical surface by a predetermined angle θ.

From this mounting posture, in the present embodiment, it is assumed that the rotation axis L2 of the adjustment gear 74 is inclined at a predetermined angle θ with respect to the horizontal direction along the vehicle left and right direction. Even when the rotation axis L2 of the gear 74 is inclined with respect to the horizontal, the rocking axis L1 of the sensor housing 32 of the acceleration sensor 30 is kept horizontal and the sensor reference line S1 of the acceleration sensor 30 points in the vertical direction Thus, the sensor cover 31 is prepared separately for each of the left and right seat types. Therefore, the pivot axis L1 of the sensor housing 32 kept horizontal with the pivot axis L2 of the adjustment gear 74 inclined with respect to the horizontal is set to intersect at a predetermined angle θ, and the above-mentioned The rotation transmission mechanism 76 is configured by a combination of the pin 74c and the slit 32h.

Here, the tilt angle (reclining angle) of the seat back 16 and the rotation angle of the sensor housing 32 (the rotation angle in the direction opposite to the tilt direction of the seat back 16) need to be synchronized with high accuracy. If the rotation angle of the seat back 16 and the rotation angle of the sensor housing 32 are not synchronized precisely, the inertial body support surface 33 can not be accurately maintained horizontal, whereby the acceleration sensor 30 can not respond accurately. .

However, when the rotation is transmitted from the adjustment gear 74 to the sensor housing 32 by the slit 32 h and the pin 74 c as in the above configuration, the rotation track surface of the pulley 73 or adjustment gear 74 and the rotation track surface of the sensor housing 32 are not mutually different. If parallel, due to it, a rotational angle deviation occurs between the adjustment gear 74 and the sensor housing 32.
In addition, backlash may occur between the components of the cable advancing and retracting mechanism 80 and the attitude control mechanism 70, and hysteresis loss occurs between the components at the time of reciprocation, which makes the position of the sensor housing 32 unstable. There is a case. In particular, due to backlash between the slit 32 h of the sensor housing 32 and the pin 74 c of the adjustment gear 74 or backlash between the gear 73 a of the pulley 73 and the gear of the adjustment gear 74, etc. Hysteresis loss occurs and tilt lock performance tends to vary.

First, the rotational angle shift that occurs when the rotational track surface of the adjustment gear 74 and the rotational track surface of the sensor housing 32 are not parallel to each other will be described. For example, assuming that the rotational raceways of both the adjusting gear 74 and the sensor housing 32 are parallel to each other and the axes (rotational axis L2 and oscillating axis L1) of the both are on the same straight line, the adjusting gear When the position of the contact point for transmission of force between the pin 74c and the slit 32h does not change constantly when the sensor housing 32 and the sensor housing 32 rotate, the trajectory of the contact point is a perfect circle. If the rotational orbital planes of both 74 and sensor housing 32 are not parallel to each other, the position of the contact point changes in the radial direction according to the rotational angle, so the rotational orbit of the contact point is noncircular (elliptical (elliptical) Shape).

Hereinafter, this will be described in detail with reference to FIG. The rotation track K1 of the slit 32h of the sensor housing 32 is a perfect circle when viewed from the horizontal direction perpendicular to the rotation track surface (vertical surface) of the sensor housing 32, as shown in FIG. 8 (d). However, as shown in FIG. 8B, the rotational orbit K2 of the pin 74c of the adjustment gear 74 is a perfect circle when viewed from the horizontal direction perpendicular to the rotational orbit surface (vertical surface) of the adjustment gear 74. As shown in FIG. 8 (c), when viewed from the horizontal direction perpendicular to the rotation orbit surface (vertical surface) of the sensor housing 32, it becomes an ellipse.

Therefore, the position of the contact point changes in the radial direction according to the rotation angle, and the trajectory of the contact point deviates from a perfect circle as shown in FIG. 8 (e) and coincides with the non-circular (elliptical pin 74c trajectory) ). As a result, a rotational angle deviation occurs between the adjustment gear 74 and the sensor housing 32. For example, when the adjustment gear 74 rotates 60 degrees, the sensor housing 32 may rotate 58 degrees or 62 degrees. Then, the inclination angle of the seat back 16 and the rotation angle of the sensor housing 32 are not synchronized, and the inertia body support surface 33 of the sensor housing 32 can not be held exactly horizontally.

Even when the inclination direction of the attitude control mechanism 70 is reverse to the case of FIG. 8A, the position of the contact point of the pin 74c and the slit 32h changes in the radial direction according to the rotation angle, and the trajectory of the contact point It becomes elliptical. However, the shape of the ellipse differs depending on the difference in the inclination direction of the attitude control mechanism 70.

Therefore, compensation means for compensating for such a rotational angle deviation is provided between the cable advancing and retracting mechanism 80 and the attitude control mechanism 70. Then, the tilt angle of the seat back 16 is transmitted to the sensor housing 32 while being corrected by an angle that allows for the rotational angle shift. As a result, the sensor housing 32 is rotated in a state in which the rotational angle deviation is compensated, so that the sensor housing 32 can be rotated so as to be substantially synchronized with the inclination angle of the seat back 16.

Specifically, assuming that the movement of the cable 13 extending from the cable advancing and retracting mechanism 80 accurately reflects the tilt angle of the seat back 16, the compensating means is provided on the pulley 73 of the attitude control mechanism 70. That is, the posture control mechanism 70 is provided with a pulley 73 that converts the forward / backward movement of the cable 13 into rotational movement and transmits the rotation to the adjustment gear 74. The circumferential path of the cable winding groove 73b of the pulley 73 is The radius r of the cable winding groove 73 b is set to be changed according to the rotation angle of the pulley 73 by forming it as a non-perfect spline curve. That is, the compensating means is constituted by the cable winding groove 73b in which the radius r of the pulley 73 formed in the spline curve shape changes.

“Spline curve shape” means, in addition to spline curves, for example, a circle on a first plane, perpendicular to the second plane to a second plane not parallel to the first plane and from above When projected, it includes, for example, a curve drawn on the circumference of the circle projected onto the non-parallel second plane.

The profile (spline curve) of the cable winding groove 73b is set based on the data of the rotational angle deviation of the adjusting gear 74 and the sensor housing 32 obtained by calculation or measurement. 9 (a) to 9 (c) are configuration diagrams of pulleys (referred to as "L15 ° pulleys" for convenience) used for the seat belt retractor for the left seat, and (d) to (f) are seat belt retractors for the right seat Is a configuration diagram of a pulley (referred to as “R15 ° pulley” for convenience) used for the above. FIG. 10 is a view showing profiles of the cable winding groove 73b of the L15 ° pulley 73L and the R15 ° pulley 73R (change of the radius r from the rotation center) in comparison with the true circle pulley.

In each of the

pulleys

73L and 73R, the radius r of the cable winding groove 73b is determined by a profile capable of compensating for the rotational angle deviation of the adjusting gear 74 and the sensor housing 32. Therefore, by incorporating these

pulleys

73L and 73R in the attitude control mechanism 70, the tilt angle of the seat back 16 and the rotation angle of the sensor housing 32 can be synchronized accurately, and the inertial body support surface 33 which is a sensor reference surface. Therefore, even at an arbitrary seatback inclination angle, it is possible to maintain the level accurately and to improve the accuracy of the acceleration sensor 30.

Next, the rotational angle shift caused by the play between the components of the cable advancing and retracting mechanism 80 and the attitude control mechanism 70 will be described. For example, as shown in FIG. 11, there is an inevitable gap s between the slit 32h and the pin 74c in order to operate the adjusting gear 74 and the sensor housing 32 smoothly. For this reason, hysteresis may occur in the rotation angle of the sensor assembly 39 driven by the reciprocating movement of the adjustment gear 74, and as a result, the attitude of the acceleration sensor 30 may vary.

On the other hand, in the acceleration sensor 30 of the present embodiment, as shown in FIG. 12, the center of gravity G of the sensor assembly 39 in a state where the sensor assembly 39 is placed at the neutral position Since the sensor assembly 39 is at a position off the extension of the vertical line V1 passing through the axis center O of L1 (left side of the vertical line V1 in FIG. 12), the swing axis L1 of the sensor housing 32 is always A rotational torque is applied to rotate counterclockwise about the center.

Thereby, in FIG. 12, the inner side surface of the left arm 32i abuts on the pin 74c, and the gap s between the slit 32h and the pin 74c is absorbed (biased in one direction) and stopped. Then, even after the inclination angle (reclining angle) of the seat back 16 is changed and the adjustment gear 74 rotates, the sensor assembled body 39 maintains the contact state between the inner side surface of the left arm portion 32i and the pin 74c. Ru.

Specifically, when the seat back 16 is turned rearward from the position shown in FIG. 13A to the position shown in FIG. 13B (that is, the seat back 16 rotates clockwise around the connecting portion 18 of the seat cushion 17). 12, the adjusting gear 74 rotates counterclockwise around the rotation axis L2, and the pin 74c moves in a direction away from the inner side surface of the left arm 32i. However, since the rotational torque for rotating the sensor assembly 39 in the counterclockwise direction about the swing axis L1 of the sensor housing 32 acts on the sensor assembly 39, the sensor assembly 39 rotates following the movement of the pin 74c. Thus, the contact between the inner surface of the left arm 32i and the pin 74c is maintained, and the level of the acceleration sensor 30 is maintained.

In addition, when the seat back 16 is returned from the position shown in FIG. 13 (b) to the position shown in FIG. 13 (a), or from the position shown in FIG. 13 (a) to the position shown in FIG. When 16 is folded (that is, the seat back 16 rotates counterclockwise around the connecting portion 18 of the seat cushion 17), in FIG. 12, the adjusting gear 74 rotates clockwise around the rotational axis L2. Thus, the pin 74c presses the inner surface of the left arm portion 32i against the counterclockwise rotational torque acting on the sensor assembly 39, and the sensor assembly 39, that is, the horizontal state of the acceleration sensor 30. Maintain.

Also, with the slit 32h of the sensor housing 32 designed so that the sensor reference line S1 of the acceleration sensor 30 points in the vertical direction with the inner side surface of the left arm 32i in contact with the pin 74c, the adjustment gear The rotation of the rotational shaft 74 is transmitted to the sensor housing 32 with high accuracy, and the accuracy of the acceleration sensor 30 can be improved. According to such a design, the dimensional tolerance of the gap s between the slit 32 h and the pin 74 c can be relaxed.

Furthermore, even if thermal deformation or wear occurs in the sensor housing 32 or the adjustment gear 74, the position of the sensor housing 32 can be measured by measuring the amount of deformation of the sensor housing 32 or the adjustment gear 74 by a temperature test or durability test. The change can be predicted, and the reliability of the acceleration sensor 30 is improved.

In the above description, the center of gravity G of the sensor assembly 39 is described on the left side of the vertical line V1 passing through the axis center O of the swing axis L1 of the sensor housing 32, but the center of gravity G of the sensor assembly 39 is The same applies to the right side of the vertical line V1. In this case, a rotational torque in the same clockwise direction as the seat back 16 rotates acts on the sensor assembly 39, and the pin 74c is in contact with the inner side surface of the right arm 32i. When the seat back 16 is turned rearward from the position shown in FIG. 13 (a) to the position shown in FIG. 13 (b), the adjusting gear 74 rotates counterclockwise around the rotation axis L2, and the pin 74c , Presses the inner side surface of the right arm 32i against the rotational torque acting on the sensor assembly 39. In addition, when the seat back 16 is returned from the position shown in FIG. 13 (b) to the position shown in FIG. 13 (a), or from the position shown in FIG. 13 (a) to the position shown in FIG. When the folding gear 16 is folded, the adjusting gear 74 is rotated clockwise about the rotation axis L2 to move the pin 74c away from the inner side surface of the right arm 32i. However, since the rotational torque for rotating the sensor assembly 39 clockwise about the swing axis L1 of the sensor housing 32 acts on the sensor assembly 39, the sensor assembly 39 rotates following the movement of the pin 74c. The contact between the inner side surface of the right arm 32i and the pin 74c is maintained, and the level of the acceleration sensor 30 is maintained.

The counterclockwise rotation of the sensor assembly 39 due to the position of the center of gravity is due to a play between components on the upstream side of the adjustment gear 74, for example, between the gear 73a of the pulley 73 and the adjustment gear 74 meshing with each other. Absorb backlash at the same time. Thus, the rotation of the pulley 73 is accurately transmitted to the sensor housing 32 through the adjustment gear 74, and the accuracy of the acceleration sensor 30 is improved.

Further, the cable advancing and retracting mechanism 80 connecting the lower end side of the cable 13 is not particularly limited in type and specification as long as the cable 13 extending from the cable advancing and retracting mechanism 80 can be accurately advanced and retracted according to the reclining angle of the seat back. .

The cable advancing and retracting mechanism 80 here has a lever 81, a casing 82, a cover 83, a pulley (second pulley) 85, and a cable adjuster 86, as shown in FIG. The lever 81 includes an arm 81a, a ring portion 81b integrated with the base end of the arm 81a, a circular hole 81c formed at the center of the ring portion 81b, and a lever protruding from the periphery of the ring portion 81b. The arm 81 a is fixed to the seat cushion 17.

The casing 82 has a cylindrical boss 82b formed inside the outer peripheral wall 82a via an annular recess 82c, and is provided with a cable lead-out portion 82d at a part of the outer peripheral wall 82a, and the boss 82b is a seat cushion. The cover 83 is fixed to the seat back 16 together with the cover 83 in a state of being positioned at the connecting portion 18 (see FIG. 1) which rotatably connects the seat back 16 and the seat back 16. Further, by fitting the boss 82 b of the casing 82 in the circular hole 81 c of the lever 81, the casing 82 is rotatably coupled to the lever 81 about the boss 82 b.

The pulley 85 has a circular hole 85c at the center of the ring portion 85a and a fan-shaped cam portion 85b at the outer periphery of a part of the ring portion 85a in the circumferential direction, and a cable on the outer peripheral surface of the cam portion 85b. The winding groove 85 d is formed, and by being rotatably fitted to the boss portion 82 b of the casing 82, the winding groove 85 d is accommodated in the annular recess 82 c of the casing 82.

An adjuster accommodating recess 85e is provided adjacent to the fan-shaped cam portion 85b at a part of the ring portion 85a of the pulley 85 in the circumferential direction, and the pulley 73 of the posture control mechanism 70 (see FIGS. 4 and 6). The proximal end of the cable 13 whose distal end is wound around is fixed to the pulley 85 via a cable adjuster 86 housed in the end block 13a and the adjuster housing recess 85e. The proximal end side of the cable 13 introduced into the casing 82 through the cable lead-out portion 82d of the casing 82 is wound around the cable winding groove 85d of the cam portion 85b of the pulley 85, although it is about 1/4 circumference. . The lower end of the outer tube 13b of the cable 13 is fixed to the cable lead-out portion 82d of the casing 82, and only the internal cable 13 is slid relative to the outer tube 13b to advance and retract toward the attitude control mechanism 70. It can be done.

The cover 83 is bolted to the casing 82 so as to cover the opening surface of the casing 82 in a state in which the pulley 85 and the ring portion 81 b of the lever 81 are accommodated in the casing 82.

When the seat back 16 tilts, the cable advancing and retracting mechanism 80 advances or reverses the cable 13 in the length direction of the cable 13 by a distance corresponding to the inclination angle of the seat back 16. For example, when the seat back 16 is tilted from the reference posture shown in FIG. 15A to the position shown in FIG. 15B, one end of the cam portion 85b of the pulley 85 abuts on the lever projection 81d of the lever 81. Although 85 does not move, the casing 82 rotates with the seat back 16 so that the outer tube 13 b of the cable 13 moves with the casing 82. As a result, the proximal end side of the cable 13 is pulled out with respect to the outer tube 13b, so the cable 13 is given a pulling-in operation (corresponding to the winding operation for the cam groove 85d of the pulley 85). It is transmitted to the control mechanism 70.

Also, conversely, when the seat back 16 is returned from the position shown in FIG. 15B to the position shown in FIG. It is returned to the proximal side. Therefore, the cable 13 pulled by the torsion spring 75 of the posture control mechanism 70 is returned into the outer tube 13b, and the cable 13 has a pushing operation (corresponding to a pulling operation for the cam groove 85d of the pulley 85). And sent to the attitude control mechanism 70.

When the seat back 16 is folded from the position shown in FIG. 15 (a) to the position shown in FIG. 15 (c), the casing 82 rotates with the seat back 16 and the casing 82 is the cam portion 85b of the pulley 85. Since the pulley 85 also rotates with the casing 82 after coming into contact with one end of the cable 13, the pulling operation of the cable 13 with respect to the outer tube 13b is not performed.
In addition, as another cable advancing and retracting mechanism 80, for example, a system in which a pinion and a rack are combined can be adopted.

Hereinafter, the operation of the present embodiment will be described.
Fig. 13 is a diagram showing the state of the seat belt retractor and the cable advancing / retracting mechanism for each inclination angle of the seat back, where (a) is the state at the time of backward inclination 15 °, (b) is the state at the backward inclination 95 °; (C) is a side view which shows the state at the time of 75 degrees of advance inclination, respectively.

Normally, the effective use range of the acceleration sensor 30 is a predetermined inclination angle range based on 15 ° behind (a), so the operation will be described on the premise that it is within that range.

When the reclining angle of the seat back 16 is adjusted, the cable 13 moves back and forth by a distance corresponding to the reclining angle, and the pulley 73 of the posture control mechanism 70 rotates in accordance with the movement of the cable 13. When the pulley 73 rotates in the same direction as the tilting direction of the seat back 16, the adjusting gear 74 rotates in the opposite direction by the same angle as the pulley 73, and the rotation is transmitted to the sensor housing 32 by the pin 74c and the slit 32h. The sensor housing 32 pivots in the opposite direction by the same angle as the tilt angle of the seat back 16, and the inertia support surface 33 of the sensor housing 32 is held horizontally.

At this time, as described above, the rotational angle shift occurs due to the rotational angle position of the adjustment gear 74 and the sensor housing 32, but the rotational angle shift is caused by the change of the radius of the cable winding groove 73b. The inclination angle of the seat back 16 and the rotation angle of the sensor housing 32 are accurately synchronized, since the pulley 73 is corrected by the rotation so as to compensate for. As a result, regardless of the reclining angle of the seat back 16, the inertial body support surface 33 of the sensor housing 32 is always held horizontally accurately.

Further, the center of gravity G of the sensor assembly 39 is set to a position out of the extension of the vertical line V1 passing through the axial center O of the swing axis L1 of the sensor housing 32, and the sensor assembly 39 is rotated in one direction. The inner side surface of the arm 32i is always in contact with the pin 74c. Therefore, the gap between the slit 32h and the pin 74c is absorbed, and the play between the components of the cable advancing and retracting mechanism 80 and the attitude control mechanism 70, in particular, the play between the slit 32h and the pin 74c is corrected.

In this state, when a horizontal acceleration larger than a predetermined value acts on the acceleration sensor 30 due to a collision of a vehicle or the like, the ball 35 which is an inertial body mounted on the inertial body support surface 33 is displaced from the neutral position. As a result, the second sensor lever 37 pivots, this pivoting is transmitted to the first sensor lever 36, and the first sensor lever 36 pivots, so that the upper claw portion 36b engages with the engagement claw of the steering wheel 25. By engaging with 25a, the rotation of the steering wheel 25 is regulated, and the extension of the seat belt 19 is prevented to restrain the occupant.

As described above, since the sensor housing 32 always maintains the inclination in the longitudinal direction of the vehicle in a horizontal state, the acceleration sensor 30 can be used for slow deceleration from moderate deceleration or slow deceleration for the vehicle traveling direction. In any case, such as in the case where the seat belt 19 is shifted to, the acceleration is properly detected, and the pulling-out of the seat belt 19 is locked without causing the locking delay of the seat belt 19.

As shown in FIG. 16, in design, when the inclination angle of the sensor assembly 39 in the counterclockwise direction is 71.27 °, the center of gravity G of the sensor assembly 39 is directed downward, and the arm 32i is pin 74c. I can not press it. Therefore, when reclining to this angle, backlash occurs between the arm 32i and the pin 74c. On the other hand, in the lock angle test in which the seat belt retractor 11 is tilted back and forth, the ball 35 in the acceleration sensor 30 rolls and the second sensor lever 37 operates to prevent the webbing from being pulled out. Since the allowable inclination angle of is 45 °, even if the rattling occurs at the above-mentioned inclination angle, there is no problem in practice.

Further, as shown in FIG. 17, normally, in the state where the pin 74c is in contact with the left arm portion, the center of gravity G is already biased forward, so that the inertial body 35 rotates clockwise of the sensor assembly 39. The second sensor lever 37 is actuated when the inclination angle exceeds 12.7 °. At this time, the center of gravity G of the sensor assembly 39 rotates counterclockwise and moves, and the angle difference with the horizontal line becomes 8.56 °. Since the center of gravity G does not exceed the vertical line V1 passing through the axial center O of the swing axis L1 of the sensor housing 32, the acceleration sensor 30 is always urged clockwise, and the second sensor lever 37 is It can operate stably.

Therefore, the sensor assembly 39 rotates counterclockwise with respect to acceleration in the backward direction of the vehicle (acceleration of the vehicle), so that no rattling occurs between the arm portion 32i and the pin 74c. Is small. On the other hand, with respect to acceleration in the forward direction of the vehicle (the vehicle decelerates), the sensor assembly 39 rotates clockwise and the pin 74c can move by an angle A between the arm portions 32i, the inertia body supporting surface The angle of 33 changes. Therefore, the shape of the inertial body support surface 33 may be set in consideration of the change of the angle A.

As described above, according to the seat belt device 10 of the present embodiment, the posture control mechanism 70 transmits the rotation of the adjustment gear 74 to the sensor housing 32 to rotate the sensor housing 32 in the longitudinal direction of the vehicle. Mechanism 76 is included. Further, the center of gravity G in a state where the sensor assembly 39 mounting the inertial body 35 on the inertial body support surface 33 is in the neutral position is a vertical line passing through the axial center O of the swing axis L1 of the sensor housing 32. Located out of V1.

Thereby, the rotation transmitting mechanism 76 transmits rotation of an angle according to the inclination angle of the seat back 16 from the adjustment gear 74 to the sensor housing 32, and the sensor assembly 39 is always rotated in one direction by the center of gravity G. , Absorb the backlash between the components of the rotation transmission mechanism 76. Therefore, the tilt angle of the seat back 16 and the rotation angle of the sensor housing 32 can be accurately synchronized regardless of the presence or size of the rattling. Therefore, the inertial body support surface 33 which is the sensor reference surface can be accurately maintained horizontal even at an arbitrary seat back inclination angle, and the accuracy of the acceleration sensor 30 can be improved.

Further, by configuring the rotation transmission mechanism 76 by the pin 74 c of the adjustment gear 74 and the pair of arm portions 32 i of the sensor housing 32, the rotation of the adjustment gear 74 can be easily transmitted to the sensor housing 32. . Further, by setting the center of gravity G of the sensor assembly 39 such that the pin 74c and the arm portion 32i always contact, the inertial body support surface 33 is accurately kept horizontal even at an arbitrary seatback inclination angle. As a result, the accuracy of the acceleration sensor 30 can be improved.

Further, in the present embodiment, the pivot axis L2 of the adjustment gear 74 and the pivot axis L1 of the sensor housing 32 are set so that the pivot axis L1 of the sensor housing 32 is installed in the horizontal direction with respect to the vehicle lateral direction. Crosses at a predetermined angle, and even if the seat back 16 tilts in the vehicle longitudinal direction, the inertial body support surface 33 of the sensor housing 32 is held in a horizontal state by the swinging of the sensor housing 32 in the vehicle longitudinal direction. Ru. Thereby, regardless of the attachment mode of the retractor frame 21 (for example, in the case of being attached to the left and attaching to the right), at least the bothersome processing of the retractor frame 21 can be made into a common part, cost reduction Can contribute to

Second Embodiment
FIG. 18 is a cross-sectional view showing the relationship between the sensor assembly and the adjustment gear (rotating member) in the seat belt device according to the second embodiment of the present invention.
In the first embodiment, by setting the center of gravity G of the sensor assembly 39 at a position deviated from the vertical line V1 passing through the axial center O of the swing axis L1 of the sensor housing 32, the slit 32h of the sensor housing 32 and the adjustment The backlash between the gear 74 and the pin 74c is absorbed. In this embodiment, the design of the center of gravity G of the sensor assembly 39 is the same as that of the first embodiment, while the pin 74c of the adjusting gear 74 is provided with a slit 74d. While being possible, it is always in contact with both inner side of arm part 32i of sensor housing 32 simultaneously.

In this case, the pin 74c of the adjustment gear 74 can easily absorb the backlash between the slit 32h of the sensor housing 32 and the pin 74c of the adjustment gear 74 by simultaneously making light contact with both inner side surfaces of the arm portion 32i by elastic force. be able to. Also, by setting the center of gravity G of the sensor assembly 39 at a position deviated from the vertical line V1 passing through the axial center O of the swing axis L1 of the sensor housing 32, the sensor assembly 39 is always rotated in one direction. Backlash between the gear 73a of the pulley 73 and the gear of the adjustment gear 74 is absorbed.
The other configurations and actions are similar to those of the first embodiment.

The present invention is not limited to the embodiments described above, and appropriate modifications, improvements, etc. are possible. In addition, the material, shape, size, number, arrangement location, and the like of each component in the embodiment described above are arbitrary and not limited as long as the present invention can be achieved.

For example, in the above embodiment, the rotation transmission mechanism 76 is configured using the pin 74 c of the adjustment gear 74 and the pair of arm portions 32 i of the sensor housing 32 positioned so as to sandwich the pin 74 c. However, the rotation transmission mechanism of the present invention is not limited to this. That is, the rotating member and the sensor housing can be opposed to each other with a predetermined gap, and can be engaged with each other such that the sensor housing 32 follows the rotation of the rotating member in both directions. An engagement portion may be provided, and the center of gravity G of the sensor assembly 39 may be set so that the engagement portion and the engaged portion always contact.

Further, the setting of the center of gravity G of the sensor assembly 39 according to the present invention is not limited to the form in which the seat belt retractor 11 is inclined in the width direction of the vehicle and attached to the seatback as in this embodiment. The present invention is also applicable to a seat belt retractor 11 in which the rotation axis L2 of the adjustment gear 74 is horizontal.

(Modification 1)
Further, in the seat belt device of the above embodiment, the compensating means is configured by making the profile of the cable winding groove 73b of the pulley 73 of the posture control mechanism 70 into a spline curve shape. However, the cable winding of the pulley 85 of the cable advancing and retracting mechanism 80 The compensation means may be configured by making the profile of the groove 85d into a spline curve shape.

That is, by forming the cable winding groove 85d of the pulley 85 of the cable advancing and retracting mechanism 80 in a spline curve shape, the winding radius of the cable 13 is set to change according to the rotation angle of the pulley 85. By doing so, it is possible to compensate for the rotational angle deviation of the adjustment gear 74 and the sensor housing 32. In this case, the profile of the cable winding groove 73b of the pulley 73 of the posture control mechanism 70 is not a spline curve but a perfect circle.

(Modification 2)
Further, as a compensating means for compensating for the rotational angle deviation of the adjusting gear 74 and the sensor housing 32, the support shaft of the pulley 73 of the attitude control mechanism 70, ie, the first pulley case 71 supporting the pulley 73 in this embodiment. Even if the profile of the support shaft 71c is in the shape of a spline, similar effects can be obtained.

(Modification 3)
Further, in the above embodiment, the adjusting gear 74 is used as a rotating member by engaging the adjusting gear 74 with the gear 73a of the pulley 73 of the attitude control mechanism 70, and the rotation of the adjusting gear 74 corresponds to the pin 74c and the slit in the sensor housing 32. Although the case of transmitting in the combination of 32 h has been described, it is also possible to configure the rotating member by the pulley 73 itself.

That is, if the winding direction of the cable 13 around the pulley 73 is set reverse to the above embodiment, the pulley 73 of the posture control mechanism 70 can be rotated in the direction opposite to the rotation direction of the seatback 16. By providing a pin and engaging with the slit 32 h of the sensor housing 32, the sensor housing 32 can be rotated in the direction opposite to the seat back 16.

Also in this case, when the rotation track surface of the pulley 73 and the rotation track surface of the sensor housing 32 are not parallel, and when the rotation is transmitted from the pulley 73 to the sensor housing 32, both rotation track surfaces are not parallel Compensating means for compensating for the rotational angle deviation that occurs as a result is provided between the cable advancing and retracting mechanism 80 and the attitude control mechanism 70.

This application is based on Japanese Patent Application (Japanese Patent Application No. 2017-162151) filed on Aug. 25, 2017, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 10 seat belt apparatus 11 seat belt retractor 13 cable 15 reclining seat 16 seat back 17 seat cushion 18 connection part 19 seat belt 21 retractor frame 22 spindle 24 lock mechanism 30 acceleration sensor 31 sensor cover 32 sensor housing 32i arm part 33 inertia body support Face 35 ball (inertial body)
37 2nd sensor lever (operating member)
39 sensor assembly 70 attitude control mechanism 74 adjusting gear (rotating member)
74c Pin 76 Rotational transmission mechanism 80 Cable advance / retraction mechanism G Center of gravity L1 Swinging axis L2 Rotational axis S1 Sensor reference line V1 Vertical line

Claims

A seat belt retractor that is attached to the seat back of a reclining seat and takes up the seat belt when needed,
The seatback of the reclining seat is disposed at the connecting portion of the seat cushion, and has a cable for detecting a tilt angle when the seatback tilts in the longitudinal direction of the vehicle and transmitting the tilt angle to the seatbelt retractor. Cable advancing and retracting mechanism,
A seat belt device comprising
The cable advancing and retracting mechanism is
The cable advances or reverses in the longitudinal direction of the cable by a distance corresponding to the tilt angle of the seat back.
The seat belt retractor is
A retractor frame fixed to the seat back;
A spindle supported by the retractor frame for winding the seat belt;
An acceleration sensor attached to the retractor frame to detect an acceleration in a longitudinal direction of the vehicle;
A lock mechanism for locking the seat belt withdrawing operation according to the acceleration in the vehicle longitudinal direction detected by the acceleration sensor;
And a posture control mechanism for keeping the sensor reference surface of the acceleration sensor horizontal.
The acceleration sensor is
A sensor cover fixed to the retractor frame;
It has an inertial body that moves in the longitudinal direction of the vehicle when an acceleration equal to or greater than a predetermined value acts in the longitudinal direction of the vehicle, and a rocking axis along the lateral direction of the vehicle, and is held by the sensor cover. A sensor assembly having the sensor reference surface, and a sensor assembly including an operation member for operating the lock mechanism to the lock side in conjunction with movement of the inertia body in the longitudinal direction of the vehicle;
The attitude control mechanism
It has a rotation member which rotates an angle according to the distance of the advance or reverse movement of the cable by the cable advancing and retracting mechanism,
The seat belt retractor further comprises:
And a rotation transmission mechanism that transmits the rotation of the rotation member to the sensor housing to rock the sensor housing in the longitudinal direction of the vehicle,
The center of gravity of the sensor assembly in which the inertial body is placed on the sensor reference surface in the neutral position is located at a position deviated from the vertical line passing through the axial center of the swing axis of the sensor housing. Seat belt device characterized in that it is located.
The rotating member and the sensor housing can be opposed to each other with a predetermined gap, and can be engaged with each other such that the sensor housing follows the rotation of the rotating member in both directions. Each has an engaged portion,
The seat belt apparatus according to claim 1, wherein the center of gravity of the sensor assembly is set such that the engaging portion and the engaged portion are in constant contact with each other.
The engaging portion of the rotating member is a pin,
The engaged portion of the sensor housing is a pair of arm portions positioned to sandwich the pin,
The seat belt apparatus according to claim 2, wherein the center of gravity of the sensor assembly is set such that the pin and the arm portion are in constant contact with each other.
The sensor housing comprises a pair of arm portions positioned to sandwich a pin provided on the rotating member,
The seat belt apparatus according to claim 1, wherein the pin is elastically deformable so that the maximum outer diameter can be reduced, and is always in contact with both inner side surfaces of the pair of arms at the same time. .
The retractor frame is fixed to the seatback by tilting in the left-right direction of the vehicle with respect to a straight line extending in the vertical direction from the center in the left-right direction of the seatback.
The rotational axis of the rotating member and the oscillating shaft of the sensor housing have a predetermined angle with respect to the lateral direction of the vehicle such that the oscillating shaft of the sensor housing is installed in the horizontal direction with respect to the lateral direction of the vehicle The seat belt device according to any one of claims 1 to 4, wherein the seat belt device crosses.