JPS586430Y2 - Seat belt bri-loading device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a seatbelt preload device that brings a restraining webbing worn by an occupant into close contact with the occupant during a vehicle emergency.

Seat belt systems are designed to protect occupants by restraining them to the vehicle using restraint webbing, but if there is a large gap between the restraint webbing and the passenger, the system may not be able to fully demonstrate its restraint performance. Failure to do so may impede safety.

For this reason, a seatbelt preload device has been proposed that moves the occupant restraining webbing in the event of a vehicle emergency and brings the webbing into close contact with the occupant before the occupant applies tension to the webbing, thereby tightly attaching the webbing to the occupant.

However, most of the conventional grid loading devices are designed to move the middle part of the webbing in case of a vehicle emergency, and this requires a protrusion into the vehicle interior, which impairs the interior comfort of the vehicle. It was large and complex.

In consideration of the above-mentioned facts, the present invention has an object to provide a seat belt preload device that is compact and can operate reliably by being incorporated into a seat belt retractor that retracts webbing by a biasing force.

The seat belt preload device according to the present invention connects the preload reel connected to the retraction device and the take-up reel for webbing winding by a clutch mechanism, and only when the preload reel is rotated by the retraction device. A preload reel and a take-up shaft are connected to apply a preload to the occupant restraint webbing, and the webbing can be freely rolled in and taken up when the vehicle is in a normal running state.

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

1 and 2 show an embodiment in which a seatbelt preload device according to the present invention is incorporated into a seatbelt retractor 10, and the seatbelt retractor 10 has a frame 12.
It is fixed to the vehicle body 16 by applying a mounting bolt 14 thereto.

Both sides of the frame 12 have legs 1 bent parallel to each other.
8 and 20, and pivotally supports the winding shaft 22.

A pair of ratchet wheels 24 are press-fitted into the winding shaft 22 between the legs 18 and 200, and by fixing the winding drum 26 between the ratchet wheels 24 and 24, the winding drum 26 is attached to the winding shaft 22. It is designed to be fixed to the

One end of an occupant restraining webbing 28 is fixed to the winding shaft 22 via a winding drum 26, and the end of the webbing 28 is wound up in layers.

A spring 32 is interposed between one end of the winding shaft 22 protruding from the foot 20 and a spring case 30 fixed to the foot 20 to direct the winding shaft 22 in the winding direction (first direction) of the webbing 28. It is biased in the direction of arrow A in Figure 1).

Therefore, when the occupant pulls the end (not shown) of the webbing 28 against the winding force of the housing spring 32, the winding shaft 22 is rotated in the unwinding direction (direction of arrow B in FIG. 1), and the webbing 28 is The mounting length can be changed.

Note that a tilting bowl 3 is provided between the legs 18 and 20 of the frame 120.
4 is hung and facing the ratchet wheel 24,
This tilting bowl 34 is placed on a pendulum 36 so that the pendulum 36
When the wheel detects vehicle acceleration and swings, it is pushed up and engages with the ratchet wheel 24.
And the unwinding rotation of the winding shaft 220 is abruptly stopped.

Note that the pendulum 36 is attached to a bracket 38 protruding from the foot portion 18.
It is suspended from.

After the other end of the winding shaft 22 is projected from the foot portion 18,
A large diameter portion 42 having an internal ratchet 40 is integrally fixed.

Further, a small diameter extension shaft 44 integrally projects from the large diameter portion 42 coaxially with the internal ratchet 40 and the winding shaft 22.

A plastic IJ load reel 46 is inserted into the extension shaft 44 and is prevented from moving in the axial direction by a bushing nut 48, but it can freely rotate with low frictional force against the extension shaft 44. ing.

Ring-shaped grooves 50 and 52 having mutually different groove widths are formed in this Brilade reel 46, and the ring-shaped groove 5
0 faces the internal ratchet 40.

Further, in this ring-shaped groove 50, as shown in FIG.
is pivoted.

A tension coil spring 56 is interposed between the rotary bowl 54 and the bottom of the ring-shaped groove 50, so that the rotary bowl 54 is urged in a direction away from the internal ratchet 40.

The internal ratchet 40 and the rotating bowl 54 constitute a clutch mechanism, and when the preload reel 46 is rapidly rotated in the winding direction of the winding shaft 42 (in the direction of arrow A), the rotating bowl 40 is moved by centrifugal force. 54 expands outward against the biasing force of the tension coil spring 56 and engages with the internal ratchet 40 to similarly rotate the internal ratchet 40 in the winding direction of the winding shaft (direction of arrow A). There is.

Further, one end of a preload webbing 58 is wrapped around the ring-shaped groove 52 of the preload reel 46 in a layered manner.
The other end of this preload webbing 58 is locked to a piston rod 62 of a retraction device 60.

This retracting device 60 has a piston rod 62 and a cylinder 64.
The cylinder 64 is arranged so as to be able to slide therein, and a gas generator 66 made of gunpowder or the like is connected to the cylinder 64.

This gas generator 66 is connected to a vehicle acceleration detection device (not shown), and in the event of a vehicle emergency, the gas generator 66 is activated to rapidly retract the piston rod 62 into the cylinder 64, passing the preload reel 46 through the preload webbing 58. The winding shaft is rapidly rotated in the winding direction.

To explain the operation of this embodiment configured in this way, in the normal running state of the vehicle, the internal tooth ratchet 40, which is a clutch mechanism, and the rotating bowl 54 are separated from each other, so the winding shaft 22 is completely rotated. The tilting bowl 34 can freely rotate against the biasing force of the single spring 32, and since the pendulum 36 maintains the vertical position, the tilting bowl 34 is separated from the ratchet wheel 24 due to its own weight.

Therefore, the occupant can unwind and attach the webbing 28 to any desired position, and can also freely change the driving position.

Next, when the vehicle is in an emergency situation such as a collision, the gas generator 66 is activated by an acceleration sensor (not shown) to rapidly generate gas, so the piston rod 62 is rapidly retracted into the cylinder 64 and preloaded. webbing 5
6 causes the preload reel 46 to rapidly rotate in the direction of arrow A by the applied tension.

Therefore, the rotating bowl 54 rotating together with the preload reel 46 expands outward due to centrifugal force and engages with the internally toothed ratchet 40, as shown in FIG. .

That is, by rotating the winding shaft 22 and the winding drum 26 in the direction of the arrow A, the webbing 28 is rapidly wound onto the winding drum 26 to generate a preload and bring the webbing 28 into close contact with the occupant wearing the webbing 28 .

On the other hand, since the pendulum 36, which swings when detecting vehicle acceleration, engages the tilting bowl 34 with the ratchet wheel 24, the rotation of the ratchet wheel 24 and the winding shaft 22 in the direction of arrow B is abruptly stopped, so that the pendulum 36 swings together with the preload reel 46. The ratchet wheel 24 rotated in the direction of arrow A is stopped at that rotational position and continues to apply tension to the webbing 28, and is not returned to the direction of arrow B.

This allows the occupant to tightly attach the webbing 28, and then the occupant is thrown in the direction of the collision, applying tension to the webbing 28, while the occupant
8, the restraint performance of the occupant is improved and safety is guaranteed.

Next, FIGS. 5 and 6 show a second embodiment of the present invention,
Care has been taken so that the 220 rotations of the winding shaft do not impart any frictional resistance to the preload reel 46.

That is, a cover 68 is fixed to the foot portion 18 of the frame 120, and the center portion of the cover 68 is a cylindrical portion 70 coaxially with the winding shaft 22 and extending in the direction of the winding shaft 22.

This cylindrical portion 10 pivotally supports an extension shaft 44 fixed to the take-up shaft 22 so that the take-up shaft 22 serves as a bearing.
is fitted so that the preload reel 46 is pivotally supported on the cylindrical portion 70.

A drawer window 74 is bored in the guide bar 68 and serves as an entrance for the freeload webbing 58.

The rest of the configuration is the same as that of the first embodiment, and the same functions can be achieved.

Therefore, in this second embodiment, in addition to the first embodiment, even when the take-up shaft 22 rotates during normal vehicle running, the preload webbing 58 does not apply any frictional resistance to the preload reel 46. It is designed so that it does not bend.

In addition to the second embodiment described above, if a connecting member having a resistance force in the compression direction is connected between the retracting device and the preload reel in place of the preload webbing 58, the preload reel can be prevented from being inadvertently caused by rotation of the take-up shaft. It will no longer be rotated.

Furthermore, in each of the above embodiments, a clutch device using an internal tooth ratchet and a rotating bowl that is moved outward by centrifugal force has been described, but this clutch mechanism is not limited to one that uses centrifugal force. A clutch or the like can also be applied, and any latch device can be applied as long as the take-up shaft can be rotated only when the preload reel is rotated by the retraction device.

As explained above, the seatbelt preloading device according to the present invention has a clutch mechanism interposed between the preloading reel and the retracting device, so the preloading device can be easily incorporated into a general seatbelt retracting device and is small. Moreover, it has an excellent effect of making it possible to obtain a reliable seat belt preload device.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a first embodiment of the seat belt preload device according to the present invention, Fig. 2 is a side sectional view of Fig. 1, Fig. 3 is a sectional view taken along the line 4 is an operational diagram of FIG. 3, FIG. 5 is a front view showing the second embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line ■--■ in FIG. 10...Seat belt retractor, 22...
... Winding shaft, 28 ... Webbing, 40 ...
... Internal tooth ratchet, 46 ... Preload reel, 54 ... Rotating bowl, 56 ...
Tension coil spring, 58... Preload webbing, 60... Retraction device, 62... Piston rod, 64... Cylinder.

Claims (1)

[Scope of utility model registration request] A take-up shaft for winding occupant restraint webbing, a retracting device that is driven in the event of a vehicle emergency, a preload reel connected to the retracting device and rotated, and a preload reel interposed between the preload reel and the take-up shaft. A preload device for a seat belt, comprising: a clutch mechanism that connects a preload reel and a take-up shaft only when the preload reel is rotated by a retraction device.