JP2000313310A - Rotary coupling device and seat belt retractor utilizing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a length in an axial direction and to variously set an amount of rotation of a driving member until the driving member couples to a driven member. SOLUTION: When a spool ring 24 is rotated relative to a locking ring 14 in α direction, a locking projection 24e engages with a locking projection 23d, resulting in integral rotation of the ring 24 and a stopper ring 23. After a predetermined amount of rotation, the locking projection 23d is removed from engagement with the locking projection 24e by an eccentric cam 14b, then only the ring 24 rotates, while the ring 23 stops. The rotation of the ring 24 causes engagement of the locking projections 24e with 23e, thereby, the both rings 24 and 23 integrally rotate again. A predetermined amount of rotation disengages the locking projections 23e from 24e, and only the ring 24 rotates. The re-engagement of the locking projection 24e with an locking projection 23f causes the integral rotation of the rings 24 and 23. Consequently, the locking projection 23f is clamped between the eccentric cam 14b and a flange 24b of the ring 24, resulting in an integral rotary coupling of the rings 24 and 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a rotary connecting device for connecting a rotating driving member to a driven member, and in particular, the driving member is driven on the driven member until it rotates a predetermined number of revolutions. The present invention belongs to the technical field of a rotary coupling device in which a driving-side member is coupled to a driven-side member when a predetermined rotation number is rotated without being coupled to a member. The present invention also belongs to the technical field of a seatbelt retractor that winds a seatbelt so as to be able to take up and pull out the seatbelt, and belongs to the technical field of a seatbelt retractor using such a rotary connection device. Say)
The present invention relates to a seat belt retractor to which the rotational coupling device is applied in order to limit the load applied to the seat belt when the use of the rotational coupling device to prevent the seat belt from being pulled out in an emergency in a belt-mounted state. Belongs to the field.

[0002]

2. Description of the Related Art Conventionally, a seatbelt device equipped on a vehicle such as an automobile restrains an occupant with a seatbelt in an emergency such as when a large vehicle deceleration acts on the vehicle during a collision or the like. This prevents the occupant from jumping out of the seat and protects the occupant.

In such a seat belt device,
The seat belt retractor for winding the seat belt is provided. The seat belt retractor includes an urging force applying unit such as a spiral spring that constantly urges a reel for winding the seat belt in a winding direction.When the seat belt is not worn by the urging force of the urging force applying unit. Although it is wound on a reel, it is pulled out against the urging force of the urging force applying means at the time of mounting, and is mounted on the occupant. Then, in the seat belt retractor, the locking means operates in an emergency as described above to prevent the reel from rotating in the pulling-out direction, thereby preventing the seat belt from being pulled out.
This ensures that the seatbelt restrains and protects the occupant in an emergency.

In the seat belt retractor of this conventional seat belt device, when the seat belt restrains and protects the occupant in an emergency such as a vehicle collision, a large vehicle deceleration occurs, so that the occupant moves forward due to a large inertia. try to. Therefore, a large load is applied to the seat belt, and the occupant receives a large impact force from the seat belt. Although this impact force is not particularly problematic for the occupant, it is desirable that the impact force be suppressed if possible.

[0005] Therefore, the conventional seat belt retractor is provided with an EA mechanism so that in an emergency with the belt mounted,
A device that limits the load applied to the seat belt has been developed. FIG. 12 is a longitudinal sectional view showing an example of a seat belt retractor provided with such an EA mechanism. In the figure, 71 is a seat belt retractor, 72 is a U-shaped frame, 73 is a webbing, 74 is a rotatable support between both side walls of the U-shaped frame 72 and takes up the webbing 73, and 75 is the above-described reel. Deceleration sensing means which operates by detecting a large vehicle deceleration occurring in an emergency, a lock mechanism which is operated by the deceleration sensing means 75 to prevent at least rotation of the reel 74 in the belt withdrawing direction, and 77 denotes a reel 74 fits axially at the center of 74
A torsion bar 78 that penetrates and rotationally connects the reel 74 and the lock mechanism 76; a spring means 78 that constantly urges the reel 4 in the belt winding direction via the bush shaft 80 by the spring force of a spiral spring 79; Reference numeral 81 denotes a pretensioner that operates in the emergency to generate the belt winding torque.

The lock mechanism 76 is supported so as to rotate integrally with the reel 74 in a normal state and stop in an emergency to generate relative rotation between the reel 74 and a pawl holder 84 for swingably holding a pawl 83. The pawl holder 84 has a male screw shaft 85. A nut-shaped stopper member 86 that rotates integrally with the reel 74 is screwed to the male screw shaft portion 85. The torsion bar 77 is formed with a first torque transmitting portion 87 that is engaged with the pawl holder 84 so as not to rotate relatively, and a second torque transmitting portion 88 that is engaged with the reel 74 so as not to rotate relatively. ing.

The belt winding torque generated by the pretensioner 81 is transmitted to a reel 74 via a bush 82 and a torsion bar 77, whereby the reel 74 winds a predetermined amount of the webbing 73. The EA mechanism is constituted by the torsion bar 77, the male screw shaft portion 85 of the pawl holder 84, and the stopper member 86.

In this conventional seat belt retractor 71, the belt winding torque generated by the pretensioner 81 in the emergency described above is transmitted to the reel 74, and the reel 74 winds the webbing 73 by a predetermined amount to firmly restrain the occupant. I do. On the other hand, the deceleration sensing means 75 operates at a large vehicle deceleration occurring in an emergency, and the lock mechanism 76 operates. Then, the pawl 83 of the lock mechanism 76 rotates and engages with the internal teeth 89 on the side wall of the frame 72, thereby preventing the rotation of the pawl holder 84 and rotating the reel 4 relative to the pawl holder 84. Therefore, the first and second torque transmitting portions 87 and 88 of the torsion bar 77 rotate relative to each other, and the torsion bar 77 is twisted.
Thereafter, the reel 74 rotates in the belt withdrawing direction while twisting the torsion bar 77, so that the load applied to the webbing 73 is limited by the torsion of the torsion bar 77, and the impact applied to the occupant is absorbed.

When the reel 74 relatively rotates with respect to the pawl holder 84, the stopper member 86 relatively rotates with respect to the male screw shaft portion 85 which is screwed, so that the stopper member 86 moves toward the pawl holder 84. When the stopper member 86 comes into contact with the pawl holder 84, further rotation of the stopper member 86 is prevented, so that rotation of the reel 74 is also prevented. In this way, the maximum torsion of the torsion bar 77 is limited, and the torsion bar 77 is prevented from being cut by the torsion.

[0010]

However, in such a conventional seat belt retractor 71, not only is the stopper member 86 provided in the reel 74, but the stopper member 86 requires a predetermined strength. Since it is a strength member, it cannot be reduced so much, so it is difficult to reduce the size of the reel 74, and it is not possible to make the reel 74 compact as a whole. In addition, since the stopper member 86 moves in the axial direction, the stopper member 86 has to be elongated in the axial direction. In order to suppress the axial length, the amount of rotation of the stopper member 86, which is the driving side member, is limited. Become so.

The present invention has been made in view of such circumstances, and has as its object to reduce the axial length and to increase the amount of rotation of a driving-side member until it is connected to a driven-side member. Is to provide a rotary connection device that can set variously. It is another object of the present invention to provide a seat belt retractor that can be formed compact as a whole by reliably reducing the size of a reel while providing an EA mechanism.

[0012]

According to a first aspect of the present invention, there is provided a rotary coupling device which includes a driving member for providing input rotation, and a driving member which is concentric with a rotation center of the driving member. A driven side member rotatable to the driving side member, and an intermediate transmission member interposed between the driving side member and the driven side member, wherein the intermediate transmission member is connected to the driving side member. A state in which the drive side member can be engaged with the drive side member during one rotation of the member and a state in which the drive side member cannot be engaged are set, and the intermediate transmission member is at least the drive side member. The input rotation is transmitted from the driving side member when the driving side member is engaged with the driven side member, and the driving side member is not engaged with the driving side member. Drive when The input rotation is not transmitted from the member, and the engageable state and the non-engageable state of the intermediate transmission member are repeated for each rotation of the drive-side member, The transmission member is configured to rotationally connect the driving-side member and the driven-side member after the rotation of the driving-side member by the set rotation amount, and to transmit the input rotation of the driving-side member to the driven-side member. It is characterized by becoming.

Further, according to a second aspect of the present invention, the drive-side member has at least a drive-side locking projection, and the intermediate transmission member is capable of engaging with the drive-side member during one rotation of the drive-side member. Is engaged with the driving-side engaging projection of the driving-side member, and is incapable of engaging with the driving-side engaging projection when in the non-engageable state. A predetermined number of stop projections, and a connection locking projection for rotatably connecting the driving side member and the driven side member, wherein the predetermined number of connection operation locking projections are provided for each rotation of the driving side member. Are sequentially set to a state in which the driving-side locking projection can be engaged and a state in which the driving-side locking projection cannot be engaged. After being set to the proper state, the connection locking projection The intermediate transmission member is adapted to rotationally connect the driving side member and the driven side member by engaging with a stop projection, and further, the predetermined number of connection operation locking projections can be engaged with the engagement member. And a control means for setting the connection-locking projection to the driving-side locking projection in addition to a setting state for the normal state and the non-engageable state.

Further, the invention according to claim 3 is characterized in that the driving-side member includes an annular portion provided concentrically with the rotation center of the driving-side member and having a driving-side locking projection formed thereon. The side member comprises a circular eccentric cam which constitutes the control means and is eccentric with respect to the rotation center of the drive side member, and the intermediate transmission member is formed in an annular shape and slides on the eccentric cam. The drive-side member is movably fitted, and the connection locking projection of the intermediate transmission member is pressed between the annular portion of the drive-side member and the eccentric cam of the driven-side member. And the driven member is rotatably connected.

[0015] Further, when the intermediate transmission member receives the input rotation from the driving side member and rotates relative to the driven side member, the intermediate transmission member rotates relative to the intermediate transmission member. An inertia force suppressing means for suppressing the inertial force of the intermediate transmission member is provided every time.

Further, in the invention according to claim 5, the inertial force suppressing means is provided on the intermediate transmitting member, the inertial force suppressing member rotating integrally with the intermediate transmitting member, and the driven side member. The inertial force suppressing member is in contact with the inertial force suppressing protrusion and presses the inertial force suppressing protrusion, whereby the inertial force suppressing protrusion is broken, thereby causing the inertial force of the intermediate transmission member to break. The feature is that it suppresses.

Further, in the invention according to claim 6, the inertial force suppressing means is provided on the intermediate transmitting member, the inertial force suppressing member rotating integrally with the intermediate transmitting member, and the driven side member. An inertial force suppressing projection, wherein the inertial force suppressing member abuts on the inertial force suppressing protrusion and overcomes the inertial force suppressing protrusion to suppress the inertial force of the intermediate transmission member. Features.

Further, the seat belt retractor of the invention according to claim 7 is a reel for winding up a seat belt, a lock means for preventing rotation of the reel in the belt withdrawal direction at the time of operation, and operating by detecting a predetermined vehicle deceleration. At least a deceleration sensing means, a lock operating mechanism for operating the locking means by operation of the deceleration sensing means, and a force limiter mechanism for limiting a load applied to the seat belt when the locking means is operated. In the seat belt retractor, the rotary connection device according to any one of claims 1 to 6 is used for the force limiter mechanism, and the driving side member of the rotary connection device is provided on the reel, and A drive-side member is provided on the lock means.

[0019]

In the rotary coupling device according to the present invention, the intermediate transmission member is set to be engaged with the driving member by one rotation of the driving member. After the relative rotation with respect to the driven member to which the rotation is transmitted, the intermediate transmission member is set in a state in which it cannot be engaged with the driving member. After that, when the drive-side member is pulled substantially one rotation, the intermediate transmission member is similarly set in a state in which it can be engaged with the drive-side member in the next rotation of the drive-side member, and the input rotation is performed from this drive-side member. After relative rotation with respect to the driven member to be transmitted, the intermediate transmission member is set in a state in which it cannot be engaged with the driving member. And, one of the driving side members
With each rotation, a state in which the intermediate transmission member can be engaged with the drive-side member and a state in which the intermediate transmission member cannot be engaged are repeatedly set, and the intermediate transmission member relatively rotates with respect to the driven-side member. After the driving member rotates by the set amount of rotation, the intermediate transmission member rotationally connects the driving member and the driven member, and transmits the input rotation of the driving member to the driven member.

Further, when the intermediate transmission member rotates relative to the driven member, the inertial force of the intermediate transmission member is suppressed by the inertial force suppressing means. Thus, the intermediate transmission member does not relatively rotate more than necessary for each rotation of the drive-side member. Further, the seat belt retractor of the present invention uses the rotation coupling device of the present invention for its EA mechanism. The shock applied to the occupant is reduced, and the occupant is firmly restrained and protected by the seat belt.

As described above, in the rotary connection device of the present invention, the driving member is rotationally connected to the driven member only by movement in the rotation direction. Therefore, since the drive-side member does not move in the axial direction, the axial length is further reduced. Also, by setting the second set rotation amount of the drive-side member variously, the rotation amount of the drive-side member until the drive-side member is connected to the driven-side member can be set variously. Then, by suppressing the inertial force of the intermediate transmission member, the rotational connection between the driving-side member and the driven-side member is more reliably performed. Further, in the seat belt retractor according to the present invention, since the above-described rotary connection device is used for the EA mechanism, even if the EA mechanism is provided, the size of the reel can be reduced more reliably, and the seat belt retractor can be used as a whole. It is formed compactly.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a seatbelt retractor to which an example of a rotary connection device according to an embodiment of the present invention is applied, and FIGS.
FIG. 4 is a partially enlarged exploded perspective view showing a partially enlarged view of FIG.
Is a partially exploded perspective view showing a part of the EA mechanism of the seat belt retractor of this embodiment, and FIG. 5 is a partial longitudinal sectional view partially showing an EA mechanism part of the seat belt retractor of this embodiment in an assembled state.

As shown in FIG. 1, a seat belt retractor 1 of this embodiment is roughly divided into a frame 2, a reel 4 for winding up a seat belt 3, and a reel 4 provided on one side of the frame 2. Locking means 5 for preventing rotation of the belt in the belt withdrawing direction α, a lock operating mechanism 6 to which the rotation connecting device of the present invention is applied to activate the locking means 5 when necessary, and a locking means for a large deceleration such as a collision. 5, when the seat belt is prevented from being pulled out, the EA mechanism 7 for limiting the load on the seat belt, the deceleration detecting means 8 for detecting the vehicle deceleration, and the reel 4 in the winding direction β of the seat belt 3. And spring means 9 for urging.

As shown in FIG. 2, the frame 2 includes a pair of parallel side walls 10, 11 and a back plate 12 connecting these side walls 10, 11. Both side walls 1 in this frame 2
Between 0 and 11, a reel 4 for winding up the seat belt 3 is arranged. One of the side walls 10 has a circular large hole 10a. A circular large hole 11a is also formed in the other side wall 11 concentrically with the large hole 10a, and a predetermined number of ratchet tooth-like internal teeth 13a are formed on the inner peripheral surface of the inside of the side wall 11. The internal tooth forming member 13 having a circular large hole formed therein has these internal teeth 1
3a is fixed concentrically with the large hole 11a. Furthermore,
In the side wall 11, the mounting hole 1 for attaching the deceleration detecting means 8 is provided.
1b is drilled.

As shown in FIG. 3, the reel 4 has a seat belt winding section 4a for winding the seat belt 3, and flange sections 4b and 4c at both ends of the seat belt winding section 4a.
A hexagonal cylindrical shaft portion 4d projecting in the axial direction from the side wall 10 and having an outer peripheral surface having a hexagonal cross section, and a spring protruding in the axial direction from the hexagonal cylindrical shaft portion 4d to apply the spring biasing force of the spring means 9. A biasing shaft 4e and a spool ring support shaft, which protrudes in the axial direction from the side wall 11 and has a predetermined number (six in the illustrated example) of protrusions 4f formed on the outer periphery thereof, support a spool ring 24 described later so as to be relatively unrotatable. 4g.

In the center of the reel 4, a through hole 4h penetrating in the axial direction is formed. This through hole 4h is
Although not shown, a portion extending to the hexagonal cylindrical shaft portion 4d and located at the hexagonal cylindrical shaft portion 4d (that is,
The inner peripheral surface of the square cylindrical shaft portion also has a hexagonal cross section. The portion of the through hole 4h up to the flange portion 4b is a relatively large hole, and the portion on the hexagonal cylindrical shaft portion 4d side of the flange portion 4b is a relatively small hole.
Although not shown, the through-hole 4h located at the hexagonal cylindrical shaft portion 4d has its spring biasing force adding shaft 4e side facing the hexagonal cylindrical shaft portion 4d.
, And a spring urging force applying shaft 4e protrudes from the side wall.

Further, as shown in FIG. 3, the locking means 5 has a locking base 14 and a pawl 15. As shown in FIG. 4, the locking base 14 has a circular disk portion 14a and the center of the disk portion 14a (that is, the reel 4a).
Eccentric cam 14b having an outer peripheral circular eccentric cam 14b formed eccentrically from the center axis of the disk portion 1 on the eccentric cam portion side.
A square hole 14c is provided. The disk unit 14a
Has a through hole 1 for rotatably supporting the pawl 15.
4d is formed, and an arc-shaped load transmitted portion 14e concentric with the through hole 14d is formed. The load transmitted portion 14 e receives a load from the pawl 15. Further, a spring supporting portion 1 for supporting one end of the pawl spring 16 is provided on the disc portion 14a.
4f (omitted in FIG. 4) is provided. A stepped shaft including a large-diameter shaft 14g and a small-diameter shaft 14h protrudes from the center of the surface of the disk portion 14a opposite to the hexagonal hole 14c in the axial direction.

On the other hand, the pawl 15 has a hole 15a formed in the rotation base end, and a fixture for a pin 17 (not shown) is fitted into the hole 15a and the through hole 14d of the locking base 14. , A pawl 15 is rotatably attached to the locking base 14. At the tip of the pawl 15, a locking claw 15b capable of engaging with the internal teeth 13a of the internal tooth forming member 13 is formed, and a cam follower 15c having a protruding shaft is provided. Furthermore,
An arcuate load transmitting portion 15d is formed on the pawl 15b. The load transmitting portion 15d applies a reaction force acting on the pawl 15b to the locking base 14 when the locking claw 15b engages with the internal teeth 13a. Is transmitted to the load transmitted portion 14e. That is, the reaction force of the pawl 15b is supported by the locking base 14.

As shown in FIG. 3, the lock operating mechanism 6
A lock gear 18, a flywheel 19, a flywheel spring 20 contracted between the lock gear 18 and the flywheel 19, a retainer housing 21 detachably fixed to the side wall 11 of the frame 2, and a locking base 14. A pawl spring 16 is provided between the lock gear 18 and the pawl spring 16.

The lock gear 18 has a disk portion 18a,
An annular flange portion 18c formed on the outer periphery of the disk portion 18a and having a predetermined number of ratchet teeth 18b formed on the outer peripheral surface thereof. A cylindrical boss 18d is formed at the center of the disk portion 18a, and a flywheel 19d is formed near the boss 18d.
A support shaft 18e is provided to rotatably support.
Further, first and second stoppers 18f and 18g for restricting the rotation of the flywheel 19 to a predetermined range are provided on the outer peripheral side of the disk portion 18a, and a cam hole 18h penetrating the disk portion 18a is formed. Have been. A cam follower 15c of the pawl 15 is provided in the cam hole 18h.
Therefore, when the lock gear 18 relatively rotates with respect to the locking base 14, the pawl 15 rotates by the cam follower 15c being guided by the cam hole 18h.
Further, the disk portion 18a is provided with a spring support portion 18i for supporting one end of the pawl spring 16.

As shown in FIG. 5, this lock gear 18
The hole of the cylindrical boss 18d is
By being fitted to the large-diameter shaft 14g, it is rotatably supported relative to the large-diameter shaft 14g.

The flywheel 19 is provided with a support hole 19a rotatably fitted to a support shaft 18e of the lock gear 18, and is provided with a locking portion 19c having a locking claw 19b formed at the tip. ing. When the flywheel 19 is rotatably supported by the support hole 19a,
The locking portion 19c is provided with first and second stoppers 18f, 1
It is located between 8g. Therefore, the rotation of the flywheel 19 is controlled by the first and second stoppers 1.
8f and 18g, when the locking portion 19c is in contact with the first stopper 18f, the locking claw 19b is retracted inward, and the locking portion 19c is in contact with the second stopper 18g. When they are in contact, the locking claws 19b project outward. Further, the flywheel 19 is provided with a spring support 19d that supports one end of the flywheel spring 20.

The pawl spring 16 has one end supported by the spring supporting portion 18i of the lock gear 18, and the other end supported by the spring supporting portion 1 of the locking base 14.
4f, the lock gear 18 is constantly urged against the locking base 14 in the belt withdrawing direction α.
Therefore, when the lock gear 18 is not operated, the pawl 15
The cam follower 15c is located at the innermost position of the cam hole 18h. In this state, the lock gear 18 is prevented from further rotating by the pawl spring 16.

The flywheel spring 20 has one end supported by a spring supporting portion 19d of the flywheel 19, and the other end supported by a spring supporting portion (not shown) of the lock gear 18, thereby connecting the flywheel 19 to the lock gear 18. It is constantly biased in the belt withdrawing direction α. Therefore, when the flywheel 19 is not operated, the locking portion 19c is in contact with the first stopper 18f and is retracted inward.

As shown by a two-dot chain line in FIG. 5, the retainer housing 21 has a disc portion 2 having a through hole 21a formed at the center (ie, concentric with the center of the rotation axis of the reel).
1b, an annular flange portion 21c formed on the outer periphery of the disk portion 21b so as to protrude toward the frame 2 and detachably fixed to the side wall 11, and a through hole 21a concentric with a surface of the disk portion 21b on the frame 2 side. Annular flange portion 2 protruding from the inner surface and having ratchet-shaped internal teeth 21d on the inner peripheral surface.
1e. This annular flange portion 21e
When the retractor 1 is assembled, the lock gear 1
8 and the first and second stoppers 18f, 18g. The locking claw 19b of the flywheel 19 is located inside the annular flange portion 18c, the flywheel 19 rotates relative to the lock gear 18, and the locking portion 19c contacts the second stopper 18g. At the position, the locking claw 19c is locked to the internal teeth 21d. As shown in FIG. 5, the small diameter shaft 14h of the locking ring 14 is rotatably fitted and supported in the through hole 21a.

E to which the rotary coupling device of the present invention is applied
The A mechanism 7 includes a torsion bar 22, an annular stopper ring 23 controlled by the eccentric cam 14b of the locking base 14, and a spool which is non-rotatably supported by the spool ring support shaft 4g of the reel flange 4c. And a ring 24. The torsion bar 22 is provided at the torsion bar portion 22a and at one end of the torsion bar portion 22a on the locking base 14 side. The first hexagonal cross section
The torque transmitting portion 22b and the other end of the torsion bar portion 22a are provided on the inner peripheral surface of the hexagonal cylindrical shaft portion 4d of the reel 4,
It comprises a reel 4 and a second torque transmitting portion 22c having a hexagonal cross section which is fitted so as not to rotate relatively.

As shown in FIG. 4, the annular stopper ring 23 has a hole 23a which is slidably fitted on the outer peripheral surface 14i of the eccentric cam 14b of the locking base 14b. When the stopper ring 23 is fitted to the eccentric cam 14b as shown in FIG.
b, and friction is generated between the outer peripheral surface 14i of the stopper ring 23 and the inner peripheral surface 23b of the hole 23a of the stopper ring 23. When a predetermined external force is not applied in the circumferential direction to the stopper ring 23, Is the locking base 14b
When a predetermined external force is applied to the stopper ring 23 in the circumferential direction without rotating relative to the
It rotates relative to b.

As shown in FIGS. 4 and 6, on the outer peripheral surface 23c of the stopper ring 23, two first and second stopper operation locking projections 23d and 23e are respectively formed at predetermined intervals in the circumferential direction. And a stopper locking projection 23f is formed. The first and second stopper operation locking projections 23d and 23e are formed in a substantially triangular shape. In this case, the surface facing the belt withdrawal direction α is made substantially perpendicular to the outer peripheral surface 23c. The surface facing the belt winding direction β is an arc-shaped surface having a relatively gentle inclination. The heights of the first and second stopper operation locking projections 23d and 23e from the outer peripheral surface 23c of the stopper ring 23 are both set to be equal.

The end face of the stopper locking projection 23f facing the belt withdrawing direction α is substantially perpendicular to the outer peripheral surface 23c. Further, the stopper locking projection 23
f has a predetermined length (width) in the circumferential direction, and its outer peripheral surface 23g is formed on the annular flange 24 of the spool ring 24.
b is formed in an arc shape of a circle having the same diameter as the inner peripheral surface 24f, and the inner and outer peripheral surfaces 23 of the stopper ring 23 are formed.
b, 23c are eccentric from the center. And FIG.
As shown in (e), the outer peripheral surface 23g can be brought into surface contact with the inner peripheral surface 23b of the stopper ring 23. Furthermore,
The height b of the stopper locking projection 23f at the edge on the belt winding direction β side from the inner peripheral surface 23b is set to be higher than the height of the edge from the inner peripheral surface 23b on the belt drawing direction α side. And the height b corresponds to the eccentric cam 1
The gap a between the outer peripheral surface 14i at the maximum eccentric position 4b and the inner peripheral surface 24f of the annular flange 24b of the spool ring 24 is set to be larger (b> a).

When the first and second stopper operation locking projections 23d and 23e and the stopper locking projection 23f of the stopper ring 23 are positioned at the maximum eccentric position from the reel rotation shaft by the eccentric cam 14b, these engagements are reduced. The tops of the stop projections 23d, 23e and 23f are designed to protrude maximally toward the inner peripheral surface 24f of the annular flange 24b of the spool ring 24 described later. For example, the first and second stopper operation locking projections For 23d and 23e,
6 (a) and 6 (c).

As shown in FIG. 2, the spool ring 24
Has a disk portion 24a and an annular flange 24b formed on the outer peripheral edge of the disk portion 24a. A large through hole 24c is formed at the center of the disk portion 24a. On the inner peripheral surface of the through hole 24c, the same number of recesses 24d as the protrusions 4f are formed, which are fitted into the protrusions 4f of the spool ring support shaft 4g. Then, the through-hole 24c of the spool ring 24 is fitted in the spool ring support shaft portion 4g in the axial direction such that the concave portion 24d is fitted in the protrusion 4f, whereby the spool ring 2 is fitted.
The reel 4 is supported by the reel 4 so as not to rotate relatively.

Further, as shown in FIGS. 2 and 6, the annular flange 24b is formed with a reel-side engaging projection 24e by recessing the annular flange 24b inward. The locking projection 24 is formed in a triangular shape. In this case, the surface facing the belt withdrawing direction α is a relatively gentle surface, and the surface facing the belt winding direction β is an annular flange. 24b inner peripheral surface 24f
It is almost perpendicular to the plane.

The locking base 14, the stopper ring 23 and the spool ring 24 constitute the rotary connecting device of the present invention in this embodiment. In that case, the spool ring 24 constitutes a driving side member of the rotary coupling device of the present invention, the stopper ring 23 constitutes an intermediate transmission member of the rotary coupling device of the present invention, and the locking base 24 further comprises the locking base 24 of the present invention. It constitutes the driven side member of the rotary coupling device.

As shown in FIG. 2, the deceleration detecting means 8
The housing 25 includes a housing 25 mounted on the side wall 11, a sensor case 26 mounted on the housing 25, an inertial mass 27 mounted on the sensor case 26, and an actuator 28 operated by the inertial mass 27. The housing 25 is provided with a fitting fitting portion 2 fitted in the fitting hole 11 b of the side wall 11 of the frame 2.
5a and a pair of support arms 2 supporting the sensor case 26
5b and 25c. In addition, sensor case 2
Reference numeral 6 denotes a pair of supported portions 26a and 26b which are engaged with and supported by the grooves of the support arms 25b and 25c, a mass mounting portion 26c on which the inertial mass 27 is mounted, and an actuator 28 rotatably. It consists of a pair of support arms 26d and 26e.

The inertial mass 27 includes a leg 27a, a mass 27b on the leg 27a, and an operating portion 27c for operating the actuator 28. The inertial mass 27 is mounted on the mass mounting portion 26c, and normally stands upright as shown in the figure, but tilts when a deceleration equal to or more than a predetermined deceleration acts on the vehicle, so that the operating portion 27c 28 is rotated.

Further, the actuator 28 is pressed by a rotating shaft 28 a rotatably fitted in and supported by holes of a pair of supporting arms 26 d and 26 e of the sensor case 26 and an operating portion 27 c of the inertial mass 27. It comprises a pressing portion 28b and a locking claw 28c provided on the side opposite to the rotating shaft portion 28a and capable of locking to the external teeth 18b of the lock gear 18. When the inertial mass 27 is in the upright state, the actuator 27 is at the lowest position, and the locking claw 28c is
When the inertia mass 27 is tilted, the engagement claw 28c is rotated upward, and the locking claw 28c is
b.

As shown in FIG. 2, the bush 29 has a hexagonal cylindrical shaft portion 29a having a hexagonal cross section that can be fitted to the outer peripheral surface of the hexagonal cylindrical shaft portion 4d of the reel 4. This bush 29 is configured to apply a rotational driving force by a pretensioner (not shown) to the reel 4 in the belt winding direction β, similarly to the above-described conventional bush. Further, the spring means 9 is connected to a spring case 30, a bush shaft 31 which is spline-fitted to the spline groove 4i of the spring urging force adding shaft 4e of the reel 4 so as to be relatively non-rotatable, and an outer end is connected to the spring case 30; A spiral spring 32 whose inner end is connected to the bush shaft 31 and constantly urges the reel 4 in the belt winding direction β is provided.

Next, the operation of the seat belt retractor of this embodiment configured as described above will be described. When the belt is not worn, the seat belt 3 is completely wound around the reel 4 by the spring force of the spiral spring 32 and is stored. In the flywheel 19 of the lock operation mechanism 6, the locking portion 19 c is in a position where it comes into contact with the first stopper 18 f by the spring force of the flywheel spring 20, and the locking claw 19 b is located inside the retainer housing 21. It is set to a non-engagement position that does not engage with the teeth 21d. Further, the inertia mass 27 of the deceleration detecting means 8 is in the upright state, and the actuator 27 is set at the non-engagement position where the locking claw 28c does not engage with the external teeth 18b of the lock gear 18 of the lock operation mechanism 6. I have. Further, the spring force of the pawl spring 16 causes the lock gear 18 to be in the non-engagement position where the pawl 15 of the lock means 5 does not engage with the internal teeth 13 a of the internal tooth forming member 13 fixed to the side wall 11 of the frame 2. This pawl 15 is controlled. Therefore, in this state, the reel 4 can freely rotate in the belt withdrawing direction α.

Further, the first stopper operation locking projection 23d of the stopper ring 23 is rotated by the eccentric cam 14b shown in FIG.
Is set at a position where it can be engaged with the reel side locking projection 24e. When the occupant of the vehicle pulls out the seat belt 3 at a normal pulling speed to wear the seat belt 3, the seat belt 3 is pulled out freely because the reel 4 is freely rotatable in the belt pulling direction α. . During the withdrawal of the seat belt 3, the pawl 15, the flywheel 19 and the actuator 27 are all held at the disengaged position, and the reel 4 freely rotates in the belt withdrawing direction α. In addition, during the pulling out of the belt, the reel 4, that is, the spool ring 24 and the locking ring 14 rotate integrally, so that the stopper ring 23 also rotates integrally with the spool ring 24 and the locking ring 14. Therefore,
The relative position between the stopper ring 23 and the spool ring 24 is maintained in the initial state.

When the occupant connects the tongue (not shown) provided on the seat belt 3 to the buckle fixed to the vehicle body and releases his / her hand from the tongue, the reel 4 takes up the seat belt 3 which has been pulled out extra, and the seat belt 3 3 fits the occupant. Thus, the seat belt 3 is worn by the occupant. Even when the seat belt 3 is fastened, the pawl 1
5, the flywheel 19 and the actuator 27 are both held at the disengaged position, and the reel 4 freely rotates in the belt withdrawing direction α. Therefore,
When the occupant tries to move forward by a predetermined amount while wearing the seat belt 3, the seat belt 3 is freely pulled out,
The occupant can move freely by a predetermined amount. Further, even in this belt mounted state, the relative position between the stopper ring 23 and the spool ring 24 is maintained in the initial state.

When the vehicle collides with an obstacle or the like while the vehicle is running, a pretensioner is activated by outputting a collision detection signal output from a collision sensor (not shown), and the belt winding torque is reduced by the torsion bar 22 via the bush 54. Second
The torque is applied to the torque transmitting portion 22c, and the torsion bar 22 rotates in the belt winding direction β. Further, the belt winding torque applied to the second torque transmission unit 22c is transmitted to the reel 3. Then, the reel 4 rotates by a predetermined amount in the belt winding direction β, and winds the seat belt 3 by a predetermined amount.
Firmly restrain the occupants. At this time, the rotation of the torsion bar 22 causes the first torque transmission portion 22b to also rotate in the same direction β, so that the locking ring 14 and the lock gear 18
Also rotates together with the reel 4 by a predetermined amount in the same direction β. On the other hand, since a very large vehicle deceleration occurs in the vehicle due to the collision of the vehicle, the inertial mass 27 of the deceleration sensing means 8 tilts forward of the vehicle. Then, the actuator 28 rotates upward, and the locking claw 28c is set to the engagement position where the engagement claw 28c can be engaged with the external teeth 18b of the lock gear 18. In this state, since the occupant tries to move forward due to inertia, the seat belt 3 is about to be pulled out, and the reel 4 is moved in the belt withdrawing direction α.
To rotate. By the rotation of the reel 4, the locking ring 14 and the lock gear 18 are also integrated with the reel 4 in the same direction α.
, The outer teeth 18b of the lock gear 18 immediately engage with the locking claws 28c to prevent rotation of the lock gear 18, and the reel 4, the locking ring 14, and the spool ring 24 continue to rotate in the same direction α. Therefore, relative rotation occurs between the locking ring 14 and the lock gear 18.

The locking ring 14 and the lock gear 1
8, the cam follower 15c of the pawl 15 moves in the cam hole 18h of the lock gear 18 while being guided by the cam hole 18h, the pawl 15 rotates upward, and the locking claw 15b The engagement position is set to engage with the internal teeth 13a of the internal tooth forming member 13 fixed to the side wall 11. With the further rotation of the reel 4 in the same direction α by the subsequent pulling out of the seat belt 3, the locking claw 15b immediately
3a. Therefore, the rotation of the locking ring 14 is prevented, and only the reel 4 and the spool ring 24 continue to rotate in the same direction α. Then, the reel 4 and the locking ring 14 rotate relative to each other, that is, the first and second torque transmitting portions 22b and 22 of the torsion bar 22.
c rotate relative to each other, the torsion bar portion 22a
Is twisted. Then, since the reel 4 rotates in the belt withdrawing direction α while twisting the torsion bar 22, the torsional deformation of the torsion bar 22 absorbs and reduces the impact applied to the occupant by the seat belt 3. .

On the other hand, since the spool ring 24 is also relatively rotated with respect to the locking ring 14 in the same direction α, and the stopper ring 23 is set in a state capable of engaging with the spool ring 24, FIG. As shown, the reel side locking projection 24e immediately comes into contact with and engages with the first stopper operation locking projection 23d. When the spool ring 24 continues to rotate relatively, the engagement between the reel side locking projection 24e and the first stopper operation locking projection 23d causes the stopper ring 2 to rotate.
3 also rotates together with the spool ring 24 in the same direction α. By this integral rotation, the reel side locking projection 24e of the stopper ring 23 is gradually moved by the eccentric cam 14b in the direction in which the engagement with the reel side locking projection 24e is released. When the reel 4 further rotates in the same direction α after the first stopper operation locking projection 23d and the reel-side locking projection 24e shown in FIG.
First stopper operation locking projection 23d and reel-side locking projection 2
4e, the spool ring 24 rotates integrally with the reel 4, and the stopper ring 23 does not rotate. That is, the stopper ring 23 is
4 and cannot be engaged. When the engagement between the first stopper operation locking projection 23d and the reel side locking projection 24e is released, the second stopper operation locking projection 23e of the stopper ring 23 can be engaged with the reel side locking projection 24e. Position, but not yet at the maximum eccentric position.

In this state, the seat belt 3
When the reel 4 further rotates in the same direction α, the spool ring 24 also rotates, and the reel side locking projection 24e of the spool ring 24 engages with the second stopper operation locking projection 23e of the stopper ring 23, Stopper ring 2
3 also rotates together with the spool ring 24 again. When the reel 4 makes almost one rotation after the engaging claw 15b of the pawl 15 is engaged with the internal teeth 13a, the second stopper operation locking projection 23e is maximized by the eccentric cam 14b as shown in FIG. Eccentric, reel side locking projection 24e
Will be engaged to the maximum. That is, the state is the same as the case where the first stopper operation locking projection 23d and the reel side locking projection 24e are engaged.

Thereafter, as in the case of the above-mentioned first stopper operation locking projection 23d, further rotation of the reel 4 and the spool ring 24 in the same direction .alpha. The engagement with the stop projection 24e gradually decreases, and FIG.
When the position exceeds the disengagement position shown in FIG. 5, the engagement between the second stopper operation locking projection 23e and the reel side locking projection 24e is released,
Again, only the reel 4 and the spool ring 24 continue to rotate in the same direction α, and the rotation of the stopper ring 23 stops. At this time, the stopper locking projection 23f is in a position where it can be engaged with the reel-side locking projection 24e, but has not yet reached the maximum eccentric position by the eccentric cam 14b. Further, when the reel 4 and the spool ring 24 rotate in the belt withdrawing direction α, the reel side locking protrusion 24e
Engages with the stopper locking projection 23f, and the stopper ring 23 again rotates integrally with the spool ring 24.

As the stopper ring 23 rotates in the same direction α, the eccentricity of the stopper locking projection 23f is gradually increased by the cam 15b, and the eccentric cam 14
b and the inner peripheral surface 24 of the annular flange 24b
The distance between the stopper locking projection 23f and the stopper locking projection 23f is gradually reduced between the both surfaces 14i and 24f. Since the minimum gap a between the two surfaces 14i and 24f is set to be smaller than the maximum height b of the stopper locking projection 23f, the stopper locking projection 23f eventually becomes as shown in FIG. The outer peripheral surface 23g is in close contact with the inner peripheral surface 24f of the annular flange 24b, and the both surfaces 14i, 24
f between the stopper ring 2
3 is suppressed. As described above, the outer peripheral surface 23g of the stopper locking projection 23f is in close contact with the inner peripheral surface 24f of the annular flange 24b, so that the load is effectively dispersed, and the stopper ring 23 moves from the annular flange 24b to the annular flange 24b.
Since no load is locally applied to b, the strength of the annular flange 24b can be reduced by that amount. However, the present invention is not limited to this.
It goes without saying that a part of g can partially contact the inner peripheral surface 24f of the annular flange 24b.

At this time, since the reel side locking projection 24e is engaged with the stopper locking projection 23f, the rotation of the spool ring 24 is also suppressed.
The rotation of the reel 4 rotating integrally with the reel 4 in the belt withdrawing direction α is stopped. That is, the spool ring 24 is integrally connected to the locking base 14 for relative rotation in the belt withdrawing direction α. As a result, the torsion bar 22 is not twisted, and the seat belt 3 is prevented from being pulled out, so that the occupant is prevented from moving forward.

As described above, the torsion bar portion 22a is twisted while the rotation difference occurs between the reel 4 and the spool ring 24 and the locking base 14.
The EA mechanism 7 exhibits an EA function for limiting a belt load at the time of a vehicle collision. When the stopper ring 23 comes into contact with the locking base 14, the EA function ends. The torsion bar 22 is limited in its maximum amount of torsion by the rotary connecting device of this example, so that the torsion bar 22 is prevented from being cut by torsion.

According to the seat belt retractor 1 of this example, since only the torsion bar 22 is provided in the reel 4, it is possible to effectively reduce the size of the reel 4. Further, since the spool ring 24 is engaged with the locking base 14 only by the movement in the rotational direction only, and the spool ring 24 does not move in the axial direction, the axial length is further reduced. In addition, since only the disk-shaped stopper ring 23 and the spool ring 24 are interposed between the reel 4 and the locking base 14, the seat belt retractor 1 does not become so long in the axial direction, and as a whole, It can be formed compact.

FIG. 7 is a perspective view similar to FIG. 4 showing another embodiment of the rotary coupling device of the present invention, and FIG. 8 shows a stopper ring 23 and a locking base 14 in this embodiment. () Is a diagram schematically showing these as viewed from the reel 4 side, and (b) is a cross-sectional view along VIIIB-VIIIB in (a). The same components as those in the above-described example are denoted by the same reference numerals, and a detailed description thereof will be omitted.

In the above example, the first and second stopper operation locking projections 23d and 23e are provided on the stopper ring 23.
Is provided, as shown in FIG.
In the rotary coupling device of this example, the first and second stopper operation locking projections 23d, 2
In addition to 3e, another third stopper operation locking projection 23h is provided. The third stopper operation locking projection 23h is also the first and second stopper operation locking projection 23.
d, 23e are formed in exactly the same shape and dimensions. Therefore, the rotation connection device of this example is set such that the relative rotation of the spool ring 24 with respect to the locking base 14 until the spool ring 24 and the locking base 14 are rotationally connected to each other is substantially three rotations.

In the above-described example, when the reel side locking projection 24e of the spool ring 24 comes into contact with the stopper operation locking projection 23d, 23e of the stopper ring 23,
Depending on the relative rotation speed of the spool ring 24 with respect to the locking base 14, the stopper ring 23 may rotate more than necessary due to its inertia. This rotation beyond necessity is temporarily performed by the outer peripheral surface 14i of the eccentric cam 14b and the inner peripheral surface 2 of the hole 23a of the stopper ring 23.
3b can be sufficiently prevented. However, in the rotary connection device of this example, for example, even when the inertia force of the stopper ring 23 is large, it is not possible to obtain a large friction between the stopper ring 23 and the spool ring 24, or the like. The ring 23 is prevented from rotating more than necessary more reliably.

For this purpose, as shown in FIG. 7, in the rotary connection device of this embodiment, the disk unit 1 of the locking base 14
4a, an arc-shaped groove 14j concentric with the eccentric cam 14b is formed. The formation position of the groove 14j is shown in FIG.
In the state where the stopper ring 23 is fitted to the eccentric cam 14b as shown by a two-dot chain line in FIG.
Is set at a position overlapping the annular main body 23i. Then, as shown in FIG. 3A, the radial direction (the direction orthogonal to the axial direction of the reel 4) extends from the inner peripheral side wall of the arc-shaped groove 14j.
First to third inertial force suppressing projections 14
k, 14m, and 14n are formed at predetermined intervals in the circumferential direction. These inertial force suppressing projections 14k, 14
The formation positions of m and 14n and the predetermined interval between them will be described later. On the other hand, a through hole 23j is formed in the annular main body portion 23i of the stopper ring 23 by the stopper locking projection 23.
The hole f is formed near the engaging end with the reel side locking projection 24e. As shown in FIG. 8B, the inertial force suppressing member 33 is fitted into the through hole 23j so as to advance into the groove 14j of the locking base 14. The inertial force suppressing member 33 may be provided in the through hole 23j in a loosely fitted state, or may be provided so as to be fitted and fixed in the through hole 23j. Further, the inertial force suppressing member 33 may be provided integrally with the stopper ring 23.

When the stopper ring 23 rotates relative to the locking base 14 in the belt withdrawing direction α, the inertial force suppressing member 33 rotates together with the stopper ring 23 and the first to third inertial force suppressing protrusions 14k, 1
4m and 14n, respectively, and pressed in the same direction α. Further, when the pressing force of the inertial force suppressing member 33 against the first to third inertial force suppressing protrusions 14k, 14m, 14n exceeds a predetermined value, the first to third inertial force suppressing protrusions 14k, 14m, 14n break. Thus, the inertial force suppressing member 33 is connected to the first to third inertial force suppressing protrusions 14k and 14k.
m, 14n can be passed through the broken part. Normally, when the relative rotation does not occur between the spool ring 24, that is, the reel 4 and the locking base 14, the inertial force suppressing member 33 is positioned on the belt winding direction β side of the first inertial force suppressing protrusion 14k.

The formation position of the first inertial force suppressing projection 14k is
The reel side locking projection 24e is the first stopper operation locking projection 2
3d, the inertia force suppressing member 33 abuts on the first inertial force suppressing projection 14k and presses the first stopper operating locking projection 23d in the belt withdrawing direction α. It is set at a position where 14k can be folded. Similarly, the second and third inertial force suppressing projections 14m
Are formed in such a manner that the reel side locking projection 24e abuts on the second and third stopper operation locking projections 23e and 23h, respectively, so that these second and third stopper operation locking projections 2e are formed.
3e, 23h in the area where the belt is pushed in the belt withdrawing direction α,
The inertial force suppressing member 33 is connected to these second and third
The second and third inertial force suppressing protrusions 14m and 14n are set at positions where they can be brought into contact with and pressed against the inertial force suppressing protrusions 14m and 14n to break the second and third inertial force suppressing protrusions 14m and 14n. Therefore, the predetermined intervals in the circumferential direction of the first to third inertial force suppressing projections 14k, 14m, and 14n are equal to the first to third inertial force suppressing projections of the stopper ring 23, respectively.
The stopper operation locking projections 23d, 23e, and 23h are set corresponding to predetermined circumferential intervals.

Another configuration of the rotary coupling device of this example has a curved shape in which each corner of the axial hexagonal hole 14c having a hexagonal cross section has a rounded R portion and each side bulges inward. Except for the above, the configuration is the same as that of the above-described example, and the configuration of the seatbelt retractor of this example is the same as that of the above-described example except for the configuration of the rotary coupling device of this example.

In the rotary coupling device of this embodiment configured as described above, the reel side locking projection 24e is connected to the first stopper operation locking projection 23d by the belt, as in the case shown in FIG. When the stopper ring 23 rotates in the same direction α, the inertia force suppressing member 33
Abuts on the first inertial force suppressing protrusion 14k and presses the first inertial force suppressing protrusion 14k. When the pressing force of the reel side locking projection 24e pressing the first stopper operation locking projection 23d increases and exceeds a predetermined value, the first inertia force suppressing projection 14k is broken by the pressing force of the inertial force suppressing member 33. Then, the inertial force suppressing member 33 becomes the first inertial force suppressing protrusion 14k.
9A, the stopper ring 23 is further rotated in the same direction α as shown in FIG. 9A, and the inertial force suppressing member 33 is turned into the broken portion 14k of the first inertial force suppressing projection 14k. '. At this time, since the first inertial force suppressing projection 14k is broken, the pressing force of the reel side engaging projection 24e against the first stopper operation engaging projection 23d is absorbed and reduced by a predetermined amount. Does not occur. For this reason, the stopper ring 23
Does not rotate more than necessary.

When the engagement between the reel side locking projection 24e and the first stopper operation locking projection 23d is released, and the spool ring 24 makes substantially one rotation with respect to the locking base 14, as in the above-described example. , Reel side locking projection 24
e again comes into contact with the next second stopper operation locking projection 23e. Then, the stopper ring 23 rotates again in the belt winding direction α together with the spool ring 24, and the inertial force suppressing member 33 contacts the next second inertial force suppressing protrusion 14m as shown in FIG. 9B. Then, the above-mentioned inertial force suppressing member 3
3 folds the second inertial force suppressing protrusion 14m in the same manner as the case where the third member abuts on the first inertial force suppressing protrusion 14k and breaks the first inertial force suppressing protrusion 14k. Since the pressing force of the reel side locking projection 24e against the second stopper operation locking projection 23e is absorbed and relaxed by a predetermined amount due to the breaking of the second inertial force suppressing projection 14m, a large inertial force is not generated in the stopper ring 23. Therefore, the stopper ring 23 does not rotate more than necessary.

Further, when the spool ring 24 makes substantially one rotation with respect to the locking base 14, the reel side locking projection 24e again comes into contact with the next third stopper operation locking projection 23h, and the inertia force suppressing member 33 is similarly formed. Folds the third inertial force suppressing projection 14n, the pressing force of the reel side locking projection 24e is absorbed and reduced by a predetermined amount, and the stopper ring 23 does not rotate more than necessary.

Thus, when the spool ring 24 rotates relative to the locking base 14, the inertial force suppressing member 33 sequentially breaks the first to third inertial force suppressing protrusions 14k, 14m, and 14n for each one rotation of the relative rotation. Thus, the inertia of the stopper ring 23 is suppressed, and unnecessary rotation of the stopper ring 23 is more reliably prevented.
As described above, the inertial force suppressing member 33 and the first to third inertial force suppressing protrusions 14k, 14m, and 14n constitute the inertial force suppressing unit of the present invention.

FIG. 10 shows the inertial force suppressing member and the first to third members.
FIGS. 8A and 8B show modifications of the stopper operation locking projection, and FIG. 8A shows a first modification thereof.
And a diagram corresponding to a portion of the first inertial force suppressing protrusion 14k,
FIG. 8B shows a second modified example, and is a view corresponding to a portion of the inertial force suppressing member 33 and the first inertial force suppressing projection 14k in FIG. 8A, and FIG. 8C shows a third modified example. (A) is a figure similar to FIG. 8 (a) which shows a 4th modification.

In the example shown in FIG. 8, the inertial force suppressing member 33 is provided with the first to third inertial force suppressing protrusions 14k, 14m, 1
4n, the inertia of the stopper ring 23 is suppressed to prevent the stopper ring 23 from rotating more than necessary. However, the first to fourth modifications shown in FIGS. In the example, the inertia force suppressing member 33 is configured to move over the first to third inertia force suppressing protrusions 14k, 14m, and 14n without breaking, and to suppress the inertia of the stopper ring 23 by the resistance when the inertial force suppressing protrusions 14k, 14m, and 14n cross over. The above rotation is prevented.

In the first modification shown in FIG. 10A, opposing surfaces of the inertial force suppressing member 33 and the first inertial force suppressing protrusion 14k (opposing surfaces opposing each other in a direction orthogonal to the axial direction of the reel 4). ) Is a flat inclined surface that is inclined in a direction away from the center toward the belt withdrawing direction α. When the stopper ring 23 relatively rotates with respect to the locking base 14 in the belt withdrawing direction α, these opposing surfaces come into contact with each other and slide relative to each other, and the inertial force suppressing member 33 causes the first inertial force to move. It rotates so as to get over the suppression protrusion 14k. The frictional resistance between the inertial force suppressing member 33 and the first inertial force suppressing protrusion 14k when the inertial force suppressing member 33 gets over the first inertial force suppressing protrusion 14k suppresses the inertia of the stopper ring 23 and prevents the stopper ring 23 from rotating more than necessary. Is done. The second and third inertial force suppressing protrusions 14m and 14n are also formed in the same shape and the same size as the first inertial force suppressing protrusion 14k, and have the same operation and effect as the first inertial force suppressing protrusion 14k. I have.

In the second modification shown in FIG. 10B, opposing surfaces of the inertial force suppressing member 33 and the first inertial force suppressing protrusion 14k (opposing surfaces opposing each other in a direction orthogonal to the axial direction of the reel 4). ) Are circular curved surfaces that bulge out on opposing surfaces of each other. The second and third inertial force suppressing protrusions 14m and 14n are also the first inertial force suppressing protrusion 14
It has the same shape and the same dimensions as k. This second modification also has substantially the same operation and effect as the first modification shown in FIG.

In the third modification shown in FIG. 10C, the opposing surfaces of the inertial force suppressing member 33 and the first inertial force suppressing protrusion 14k (the opposing surfaces that oppose each other in the axial direction of the reel 4) are not shown. Like the first modification shown in FIG. 10A, the inclined surface is flat. These inclined surfaces are flat inclined surfaces inclined in the direction of the spool ring 24, that is, the reel 4, toward the belt withdrawing direction α. The second and third inertial force suppressing protrusions 14m and 14n are also formed in the same shape and the same size as the first inertial force suppressing protrusion 14k. This third modification also has substantially the same operation and effect as the first modification shown in FIG.

In the fourth modification shown in FIG. 10D, the opposing surfaces of the inertial force suppressing member 33 and the first inertial force suppressing protrusion 14k (opposing surfaces opposing each other in the axial direction of the reel 4) are mutually opposed. It is a circular curved surface that swells out on the opposing surface of the opponent. Second and third inertial force suppressing projections 1
4m and 14n are also formed in the same shape and the same size as the first inertial force suppressing protrusion 14k. This fourth modification is also the same as in FIG.
The same operation and effect as those of the first modification shown in FIG.

In the above-described example, two stopper operation locking projections 23d, 23e or three stopper operation locking projections 23d, 23e, 23h are provided so that the spool ring 24 as the driving side member and the driven side member are provided. The relative rotation of the spool ring 24 with respect to the locking base 14 until the locking base 14 is rotationally connected to each other is set to approximately 2 or 3 rotations. However, the rotation connecting device of the present invention is not limited to this. However, depending on the desired number of relative rotations of the driving side member relative to the driven side member until the driving side member and the driven side member are connected to each other, one or more stopper operation locking projections are provided. be able to. When the inertial force suppressing protrusion is provided to suppress the inertia of the stopper ring 23, the inertial force suppressing protrusion may be provided in the same number as the stopper operating locking protrusion in relation to the stopper operating locking protrusion as described above. To

In the above-described example, the first to third inertia force suppressing projections 14k, 14m, and 14n project from the inner peripheral side wall of the arc-shaped groove 14j into the groove 14j.
These first to third inertial force suppressing projections 14k, 14m,
The groove 14j may project from the outer peripheral side wall of the groove 14j into the groove 14j, or may project from the bottom of the groove 14j into the groove 14j as shown in FIGS. 11 (a) to 11 (e). . Further, the first to third inertial force suppressing projections 14k, 14m, 14n may be protruded into the groove 14j from at least two of the outer peripheral side wall and the bottom of the groove 14j.

Further, in the above-described example, the rotation of the locking base 14 of the driven side member is restricted, and the spool ring 24 of the driven side member is connected to the locking base 14 via the stopper ring 23 which is an intermediate transmission member. When the rotation is performed, the rotation of the spool ring 24 is stopped. However, in the rotation coupling device of the present invention, the rotation of the driven side member is not restricted, and the driving side member is received via the intermediate transmission member. When connected to the driving side member, the driving side member and the driven side member may rotate together.

Further, the rotary connecting device of the present invention is not limited to the one constituted by the locking base 14, the stopper ring 23 and the spool ring 24 as in the above-described embodiment, and at least the drive A side member, a driven side member, and an intermediate transmission member interposed between the driving side member and the driven side member, and the rotation of the driving side member causes the intermediate transmission member to move relative to the driven side member. After the relative rotation by a predetermined rotation amount, the relative rotation of the intermediate transmission member with respect to the driven-side member is stopped every one rotation of the driving-side member, and after the predetermined rotation of the driving-side member, the driving-side member and the driven-side Any structure may be used as long as the member is connected via an intermediate transmission member.

Further, the rotary connecting device of the present invention is applied to a seat belt retractor, but the rotary connecting device of the present invention is not limited to this, and in addition to the seat belt retractor, a driving member is driven. The present invention can be applied to any rotary connection device as long as the drive side member is connected to the driven side member after relatively rotating by a predetermined number of rotations in a free state with respect to the side member.

[0082]

As is clear from the above description, according to the rotary connection device of the present invention, the drive side member is rotatably connected to the driven side member only by movement in the rotation direction. The side member does not move in the axial direction, and the axial length can be further reduced. Also, the second of the driving side members
By variously setting the set rotation amount, it is possible to variously set the rotation amount of the driving-side member until it is connected to the driven-side member. Further, since the inertial force of the intermediate transmission member is suppressed, the rotational connection between the driving-side member and the driven-side member can be more reliably performed.

Further, according to the seat belt retractor of the present invention, the rotation coupling device of the present invention is used for the EA mechanism. Therefore, even if the EA mechanism is provided, the size of the reel can be reduced, particularly, the diameter of the reel can be reduced. As a result, the seat belt retractor can be formed more compact as a whole.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a seatbelt retractor to which an example of a rotary connection device according to an embodiment of the present invention is applied.

FIG. 2 is a partially enlarged exploded perspective view showing a part of FIG. 1 in a partially enlarged manner.

FIG. 3 is a partially enlarged exploded perspective view showing another part of FIG. 1 in an enlarged manner.

FIG. 4 is a partially exploded perspective view showing a part of the EA mechanism of the seat belt retractor of this example.

FIG. 5 is a partial longitudinal sectional view partially showing an EA mechanism part of the seat belt retractor in this example in an assembled state.

FIG. 6 is a view schematically showing the locking base, the stopper ring and the spool ring as viewed from the side opposite to the reel, and explaining the operation of the EA mechanism in this example.

FIG. 7 is a perspective view similar to FIG. 4, showing another example of the embodiment of the rotary connection device of the present invention.

8A and 8B show a stopper ring and a locking base in the example shown in FIG. 7, wherein FIG. 8A schematically shows these as viewed from the reel side, and FIG. 8B shows VIIIB-V in FIG.
It is sectional drawing which follows IIIB.

FIGS. 9A and 9B illustrate the operation of the rotary coupling device in the example shown in FIGS. 7A and 7B, wherein FIG. 9A is a view showing a state immediately after the inertial force suppressing projection is broken, and FIG. It is a figure showing the state where it contacted.

FIGS. 10A to 10D are diagrams showing modified examples of an inertial force suppressing member and an inertial force suppressing protrusion, respectively.

FIGS. 11A to 11E are diagrams showing other modifications of the inertial force suppressing member and the inertial force suppressing protrusion, respectively.

FIG. 12 is a longitudinal sectional view showing an example of a seat belt retractor provided with a conventional EA mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Seat belt retractor, 2 ... Frame, 3 ... Seat belt, 4 ... Reel, 5 ... Locking means, 6 ... Lock operating mechanism, 7 ... EA mechanism, 8 ... Deceleration detecting means, 9 ... Spring means, 14 ... Locking Base, 14b: eccentric cam, 14j: groove, 14k: first inertia force suppressing projection, 14m
... second inertial force suppressing protrusion, 14n ... third inertial force suppressing protrusion,
Reference numeral 15: pawl, 22: torsion bar, 22b: first torque transmitting portion, 22c: second torque transmitting portion, 23: stopper ring, 23d: first stopper operation locking projection, 23e
... Second stopper operation locking projection, 23f ... Stopper locking projection, 24 ... Spool ring, 24e ... Reel side locking projection, 33 ... Inertial force suppressing member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Joji Mishina 1-4-30 Roppongi, Minato-ku, Tokyo Inside Takata Corporation (72) Inventor Hiromasa Tanji 1-4-4-30 Roppongi, Minato-ku, Tokyo Takata Stock In company

Claims (7)

[Claims] 1. A drive-side member for providing input rotation, a driven-side member disposed concentrically with the center of rotation of the drive-side member and connectable to the drive-side member in a rotational direction, and these drive-side members And an intermediate transmission member interposed between the driven-side member and the intermediate transmission member. The intermediate transmission member can be engaged with the drive-side member during one rotation of the drive-side member. An engagement disabled state is set. Further, when the intermediate transmission member is at least in a state capable of engaging with the drive side member, the input rotation is transmitted from the drive side member and the driven member is driven. The input member is configured to rotate relative to the side member, and the input rotation is not transmitted from the drive member when in a state where the input rotation cannot be engaged with the drive member. In The engageable state and the non-engageable state are repeated for each rotation of the drive-side member, and the intermediate transmission member rotates the drive-side member after rotation of the drive-side member by a set rotation amount. A rotation connection device, wherein a member and the driven side member are rotationally connected to each other, and an input rotation of the drive side member is transmitted to the driven side member. 2. The drive-side member has at least a drive-side locking projection, and the intermediate transmission member is configured to be in the drive-side state when the intermediate transmission member is in the engageable state during one rotation of the drive-side member. A predetermined number of connection operation locking projections that are engageable with the driving side locking projections of the member and are not engageable with the driving side locking projections in the non-engageable state. And a connection locking projection for rotatably connecting the drive side member and the driven side member, wherein the predetermined number of connection operation locking projections are sequentially provided for each rotation of the drive side member. After being set to a state in which it can be engaged with the projection and to a state in which it is impossible to engage, and after all of the connection operation locking projections are set to the state in which the engagement and the engagement are not possible, Wherein the connection locking projection engages with the driving side locking projection. The intermediate transmission member is configured to rotationally connect the driving-side member and the driven-side member, and further, the predetermined number of connection operation locking projections can be engaged and not engaged. And set it to
2. The rotary connection device according to claim 1, further comprising control means for engaging said connection locking projection with said driving side locking projection. 3. The driving-side member includes an annular portion provided concentrically with the rotation center of the driving-side member and having a driving-side locking projection formed thereon, and the driven-side member includes the control unit. And a circular eccentric cam eccentric with respect to the rotation center of the drive side member, wherein the intermediate transmission member is formed in an annular shape and slidably fitted to the eccentric cam. The drive-side member and the driven-side member are connected to each other by the connection-locking projection of the intermediate transmission member being pressed between the annular portion of the drive-side member and the eccentric cam of the driven-side member. 3. The rotary connection device according to claim 2, wherein the rotary connection is performed. 4. When the intermediate transmission member receives the input rotation from the driving-side member and rotates relative to the driven-side member, the intermediate transmission member receives the input rotation for each relative rotation of the intermediate transmission member. 4. The rotary connection device according to claim 1, further comprising an inertial force suppressing unit that suppresses an inertial force. 5. The inertial force suppressing means includes an inertial force suppressing member provided on the intermediate transmitting member and rotating integrally with the intermediate transmitting member, and an inertial force suppressing protrusion provided on the driven side member. The inertial force suppressing member abuts against the inertial force suppressing protrusion and presses the inertial force suppressing protrusion, whereby the inertial force suppressing protrusion is broken to suppress the inertial force of the intermediate transmission member. 5. The rotary coupling device according to claim 4, wherein: 6. The inertial force suppressing means includes an inertial force suppressing member provided on the intermediate transmitting member and rotating integrally with the intermediate transmitting member, and an inertial force suppressing protrusion provided on the driven side member. 5. The inertial force suppressing member abuts on the inertial force suppressing protrusion and rides over the inertial force suppressing protrusion to suppress the inertial force of the intermediate transmission member. Rotary coupling device. 7. A reel for winding a seat belt, locking means for preventing rotation of the reel in the belt withdrawal direction during operation, deceleration sensing means for operating by detecting a predetermined vehicle deceleration, and sensing the deceleration. 7. A seat belt retractor comprising at least a lock operating mechanism for operating said locking means by operation of said means, and a force limiter mechanism for limiting a load applied to said seat belt when said locking means is operated. The rotational connection device according to any one of the above, is used in the force limiter mechanism, the drive-side member of the rotation connection device is provided on the reel, and the driven-side member is provided on the lock unit. A seat belt retractor.