JPH0245096Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a webbing take-up device for use in a seat belt device for protecting an occupant in a vehicle emergency, and for winding webbing for restraining an occupant.

A webbing take-up device used in a seat belt device uses a biasing force to wind up the end of the webbing for restraining an occupant, and in the event of a vehicle emergency, a lock device is used to instantly stop unwinding of the webbing.

This locking device has great strength because it is necessary to reliably support the inertia of the occupant who moves violently in the direction of collision in the event of a vehicle emergency.

For this reason, a webbing take-up device has been proposed in which a lock plate is attached to a take-up shaft and this lock plate is engaged with an internal toothed ratchet in case of a vehicle emergency.

However, in this winding device, the internal ratchet is attached to a frame for supporting the winding shaft using rivets or the like, and the structure is complicated and assembly is complicated.

In consideration of the above facts, the present invention aims to provide a webbing take-up device which uses a combination of a lock plate and an internal tooth ratchet, and which has a simple structure and is easy to assemble.

The webbing take-up device according to the present invention is configured such that an internal tooth plate with an internal tooth ratchet carved therein is fitted into an irregularly shaped hole of a take-up shaft support frame to attach the internal tooth plate to the take-up shaft support frame. There is.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the webbing retractor 10 according to this embodiment has a frame 12 fixed to a vehicle body 16 with mounting bolts 14. As shown in FIGS.

A take-up shaft 22 is pivotally supported on leg plates 18 and 20 extending parallel to each other from both sides of the frame 12, and one end of an occupant restraint webbing 24 is layered in the center of the take-up shaft 22. It is wound up. Further, the inner end of a mainspring spring 26 is attached to the end of the winding shaft 22 that passes through the leg plate 20, and the outer end of this mainspring spring is connected to a spring case 28 fixed to the leg plate 20.
It is locked to. Therefore, the winding shaft 22 is biased in the winding direction of the webbing 24 (in the direction of arrow A).

One leg plate 18 has a stepped portion 29 formed by stamping.
A recessed portion is formed by providing a displacement portion 30 through which a recessed portion is formed. The recess formed by this stamping process is hexagonal when viewed in the axial direction of the winding shaft 22, and the displacement portion 30
A circular hole 31 is bored in the center of the winding shaft 22 to pivotally support the winding shaft 22.

An internally toothed plate 32 having a hexagonal planar shape is fitted into this recess. This internally toothed plate 32 has the same wall thickness as the depth of the stepped portion 29, and an internally toothed ratchet gear 32A is carved on the inner periphery.

If this internally toothed plate 32 has an external dimension that can be press-fitted into the concave portion of the leg plate 18, it can be easily and reliably fixed to the leg plate 18 without requiring any special adhesive means. Further, the attachment means is not limited to press-fitting, and other means such as using an adhesive or pressing the dust cover 33 onto the leg plate 18 can be applied.

A pair of lock plates 34 and 36 are supported on the winding shaft 22 in correspondence with each other inside the internally toothed plate 32. These lock plates 34 and 36 have a recess 40 formed in the center thereof to receive a rectangular protrusion 38 which is a radial protrusion of the winding shaft 22.
As a result, the overall shape of the lock plates 34, 36 is approximately C-shaped. Also, both ends of this C-shape, that is, a lock plate 3 that holds the winding shaft 22 in between.
The end faces 42 of the winding shafts 4 and 36 are arranged on a straight line including the axis of the winding shaft 22, and serve as a contact surface with the other lock plate.

A lock pawl 44 is formed on a part of the outer periphery of the pair of lock plates 34, 36, and when the lock plates 34, 36 move in opposite directions, they mesh with the internally toothed ratchet gear 29A and lock the lock plates 34, 36. Rotation around the winding shaft 22 is stopped. Further, from one side of these lock plates 34 and 36, a pair of pins 4 are respectively attached.
6 protrudes parallel to the winding shaft 22.

A support shaft 48 is disposed coaxially with the rectangular protrusion 38 of the winding shaft 22 and rotates in pairs with the winding shaft 22 . A lock ring 50 is relatively rotatably supported on this support shaft 48, and four elongated holes 52 are formed on the surface of the lock ring 50 on the lock plate side.
is formed. Pins 46 protruding from the lock plates 34 and 36 are accommodated in these elongated holes 52, respectively, and the pair of lock plates 34 and 3 are connected to each other.
6 are movable in opposite directions by the stroke of the elongated hole 52.

A torsion coil spring 54 is interposed between the lock ring 50 and the support shaft 48, and the lock ring 50 is biased clockwise (webbing pulling direction) with respect to the winding shaft 22 in FIG. Therefore, locking wheel 50
When the take-up shaft 22 is unwound in the webbing pull-out direction at a predetermined acceleration or less, it receives a spring biasing force, follows the take-up shaft 22, and rotates integrally with the take-up shaft 22. However, when the webbing pull-out rotation of the take-up shaft 22 exceeds a predetermined value, the torsion coil spring 54 is deflected to cause a rotation delay.

During this rotation delay, the winding shaft 22 moves the lock plates 34, 36 in opposite directions, and the pins 46 of the lock plates 34, 36 move within the elongated holes 52.

The lock ring 50 has ratchet teeth 56 on its outer periphery.
is engraved and corresponds to the pawl 58 pivotally supported on the leg plate 18. This pole 58 is the leg plate 18
It is pushed up by an inertia ball 62 housed in a case 60 and meshes with the ratchet teeth 56. This inertia ball 62 separates the pawl 58 from the ratchet teeth 56 when the vehicle is normally running, but when the vehicle acceleration reaches a predetermined value, it moves and meshes the pawl 58 with the ratchet teeth 56, thereby pulling out the webbing of the locking wheel 50. The rotation is stopped to create a rotation delay between the winding shaft 22 and the winding shaft 22.

Winding device 10 of the present embodiment configured as described above
In this case, the internal toothed plate 32 is fixed to the leg plate 18 by simply press-fitting the internal toothed plate 32 into the recess formed by the displacement portion 30 in the leg plate 18, so special attachment means such as rivets are not required as in the conventional example. It is not necessary and is extremely easy to install.

Next, the operation of this embodiment will be described. The occupant pulls out the webbing 24 from the take-up shaft 22 and attaches it.
During the draw-out and take-up operations of the webbing 24 during normal use, a large rotational acceleration is not generated on the take-up shaft 22, so the lock ring 50 rotates following the take-up shaft 22, and the pull-out rotation of the take-up shaft 22 is locked. There's nothing to do.

When the vehicle is in an emergency situation such as a collision, the occupant wearing the webbing 24 moves in the direction of the collision, so the webbing 24 is suddenly pulled out from the take-up shaft 22.
A large unwinding acceleration is generated on the winding shaft 22.

For this reason, the lock wheel 50 causes a rotational delay with respect to the winding shaft 22, and the rectangular protrusion 38 drives the lock plates 34 and 36 in opposite directions through the recess 40, and meshes with the internally toothed ratchet gear 32A. .
Therefore, the rotation of the webbing pull-out of the take-up shaft 22 is stopped instantaneously, and the occupant is restrained by the webbing 24, thereby ensuring safety.

In particular, the internal tooth plate 32 has a hexagonal outer shape that is similar to that of the leg plate 1.
8, the rotational force is reliably supported by the leg plate 18, ensuring the restraint of the occupant.

In addition, since the vehicle acceleration that occurs in a vehicle emergency moves the inertia ball 62, the pawl 58 stops the rotation of the lock wheel 50, which also causes relative rotation between the lock wheel 50 and the winding shaft 22. do.
Therefore, even if the occupant is not thrown in the direction of the collision, or before the occupant is thrown, the webbing 2
4 can be set as a restraint state.

In the above embodiment, the structure in which the concave portions of the internal tooth plate 32 and the leg plate 18 are hexagonal has been described, but any irregular shape that is non-circular, such as a polygon or an inertia circle, can be applied.

As explained above, the webbing take-up device according to the present invention forms an irregularly shaped hole in the take-up shaft support frame,
Since the internal tooth plate is constructed to fit into this irregularly shaped hole, the internal tooth ratchet can be easily and reliably attached to the frame with a simple structure, which has an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the webbing retractor according to the present invention, Fig. 2 is a left side view of Fig. 1 with the lock ring removed, and Fig. 3 is the attachment relationship between the frame and the internal gear plate. FIG. 10... Winding device, 12... Frame, 18...
... leg plate, 22 ... winding shaft, 24 ... webbing,
29...Step part, 30...Displacement part, 32...Internal tooth plate, 32A...Internal tooth ratchet gear, 34,
36...Lock plate.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A lock plate is held on the take-up shaft that winds up the webbing for occupant restraint, and in the event of a vehicle emergency, this lock plate engages with the internal tooth ratchet to stop the webbing pull-out rotation of the take-up shaft. In the webbing take-up device, an irregularly shaped hole is formed in the support frame of the take-up shaft, and an internal tooth plate with an internal tooth ratchet is fitted into the irregularly shaped hole of the take-up shaft support frame. A webbing take-up device characterized by attaching a plate to a take-up shaft support frame. (2) The webbing take-up device according to claim 1, wherein the irregularly shaped hole is a recess formed by punching into the take-up shaft support frame.