Vehicle-occupant restraint system

A vehicle-occupant restraint system includes a base attached to a vehicle part, an anchor attached to the base swingably in a front-back direction of a vehicle, an inflator attached to the base or anchor, and a lap belt attached to the anchor at one end thereof and including an inflatable part connected to the inflator. A first cover is attached to the vehicle part and has an upper opening through which the lap belt passes to be connected to the anchor. A second cover covers the upper opening and a part of the lap belt. The second cover has an upper flange and a lower flange to define a space therebetween so that a marginal part of the upper opening is interposed therebetween. The space increases toward a front side of the second cover so that the second cover is swingable in the front-back direction.

TECHNICAL FIELD

The present invention relates to a vehicle-occupant restraint system having a lap belt including an inflatable part inflatable when a vehicle collision occurs.

BACKGROUND ART

A structure is described in FIG. 2 of WO01/036235 (PCT Japanese Translation Patent Publication No. 2003-525797), in which a retractor is arranged on a vehicle floor and the end of an inflatable lap belt is retracted around the retractor. In this conventional example, an inflator is arranged on the vehicle floor and a gas is introduced to the lap belt via a special structure called a plenum.

In the above-mentioned PCT Japanese Translation Patent Publication No. 2003-525797, the special member called the plenum is used so as to have a complicated structure and high cost. The plenum is also bulky and the degree of freedom in arrangement is low.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a vehicle-occupant restraint system, in which a gas in an inflator is to be introduced into an inflatable part of a lap belt from an end of the lap belt, capable of simplifying the attaching the end of the lap belt and the inflator to a vehicle body side member. It is another object of the present invention to provide the vehicle-occupant restraint system, in which an anchor is swingable along with the swinging of the lap belt.

A vehicle-occupant restraint system according to the present invention includes a lap belt including an inflatable part, into which gas is introduced from its one end, and an inflator configured to inflate the inflatable part, in which the one end of the lap belt is attached, via an anchor, to an anchor-attaching part of a vehicle body or a seat, and the anchor is attached swingably about the anchor-attaching part within a predetermined angular range.

A projection may be provided in one of the anchor and the anchor-attaching part while an arc-shaped part to be engaged with the projection may be provided in the other, so that the anchor may be swingable within the movable range of the projection in the arc-shaped part.

The inflator may be fixed to the anchor.

The anchor may be covered with a cover, and the cover may swing integrally with the anchor.

The anchor-attaching part may be provided in one of a B pillar, a seat frame, and a vehicle chamber floor of the vehicle body.

DETAILED DESCRIPTION

In a vehicle-occupant restraint system according to the present invention, gas of an inflator is introduced into a lap belt inflatable part from an end of the lap belt. The end of the lap belt is attached, via an anchor, to an anchor-attaching part provided in a B pillar, a seat frame, or a vehicle chamber floor, simplifying the attaching it to the B pillar, the seat frame, or the vehicle chamber floor.

According to the present invention, since the anchor is swingable about the anchor-attaching part within a predetermined angular range, the anchor swings by following the swing of the lap belt due to the shift of the seat in the front-back direction or a posture change of an occupant (bending forward, for example). Hence, the load of the lap belt produced in the vicinity of the anchor-attaching part is alleviated, so that the required level of the wear resistance, etc., is relaxed.

According to the present invention, the projection provided in one of the anchor and the anchor-attaching part may be brought into engagement with the arc-shaped part provided in the other, so that the swingable range of the anchor may be restricted, simplifying such configurations of the system and reducing cost.

In the vehicle-occupant restraint system according to the present invention, when a collision (including a side impact according to the present invention or may also include a lateral turning) of the vehicle is detected or foreknown by the detection sensor or the foreknowing sensor provided in the vehicle, for example, on the basis of the detection signal or the foreknown signal from the sensor, the inflator is started for discharging gas so that the gas from the inflator is introduced into the inflatable part so as to inflate the inflatable part, thereby restraining an occupant to the seat and absorbing the impact applied to the occupant with the inflated inflatable part.

By fixing the inflator to the anchor, the attachment of the inflator to the B pillar or the vehicle chamber floor is simplified.

By covering the anchor and further the inflator with a cover, the appearance is also improved.

FIGS. 1 and 2are perspective and front views of a vehicle seat having a vehicle-occupant restraint system according to an embodiment, respectively;FIG. 3is a drawing viewed in arrow III-III direction ofFIG. 2;FIG. 4ais a sectional view at the line IV-IV ofFIG. 5;FIG. 4bis a perspective view of part ofFIG. 4a;FIG. 5andFIGS. 6aand6bare sectional views at the line V-V and at the line VI-VI ofFIG. 3, respectively;FIG. 7is a perspective view of the vicinity of the vehicle seat viewed from the rear; andFIGS. 8aand8bare plan views illustrating the internal structure of a lap bag.FIGS. 2 and 6bshow the inflated state of the lap bag; other drawings show the state before inflation of a lap belt;FIG. 8ashows the state of the bag body of the lap bag folded in a strip shape; andFIG. 8bshows the flatly extended state of the bag body.

On a vehicle chamber floor F, a pair of seat rails1are extended in parallel in the front-back direction of a vehicle, on which a vehicle seat10is arranged movably in the front-back direction of the vehicle.

The seat10includes a seat frame11, a seat cushion12placed on the seat frame11, a seat back13arranged to stand from the rear of the seat cushion12and to be capable of reclining, and a head rest14attached on the top of the seat back13.

A vehicle-occupant restraint system20includes webbing21routed along the front of an occupant sitting on the seat10, an inflatable lap bag22constituting the end portion of a lap belt portion21a(below-mentioned) of the webbing21, an inflator23for inflating the lap bag22, an anchor24for attaching the end of the lap bag22to a vehicle body, and a retractor25(FIG. 5) for retracting the rear end of the webbing21.

The webbing21is made of a normal non-inflatable belt material. The rear end of the webbing21is connected to the seat belt retractor25retractably therearound after being hooked through a shoulder anchor29arranged in an upper side portion of a vehicle chamber. An intermediate portion of the webbing21is hooked through a tongue28(FIG. 2).

Along the webbing21, the side toward the anchor24from the tongue28becomes the lap belt portion21athat is routed along front faces of the lower back and the abdominal part of an occupant sitting on the seat10, while the side toward the shoulder anchor29from the tongue28becomes a shoulder belt portion21bthat is routed along the front face of the upper body of the occupant.

The rear end (upper ends ofFIGS. 3 to 5) of the lap bag22is connected to the end of the webbing21of the lap belt portion21awith stitching.

The end of the lap bag22, as shown inFIG. 4, is inserted into an opening24aof the anchor24and sewn therein, so that the lap bag22is connected to the anchor24.

The lap bag22includes a bag body50, mesh webbing (not shown) surrounding the bag body50, and a protection cover (not shown) covering the substantial whole mesh webbing and the end portion of the webbing21.

The bag body50is made by overlapping a plurality of pieces of base cloth with the periphery stitched along a seam50ato have a bag. The rear end of the bag body50is sewn to the end of the webbing21into a seam51. As shown inFIG. 8a, the maximum width of the base cloth is larger than the width of the webbing21. The bag body50, as shown inFIG. 8b, is made in a strip shape with the substantial same width as that of the webbing21by folding back both lateral sides. From the end of the lap belt portion21aof the bag body50, a gas introducing duct59is extended.

The mesh webbing covers the folded strip-shaped bag body50. The mesh webbing is made of knitted fabric that can scarcely elongate in the longitudinal direction while can elongate flexibly in width and expanding directions.

The rear end of the mesh webbing is stitched to the vicinity of the end of the webbing21. The front end of the mesh webbing is connected to the anchor24by inserting the front end into the opening24aof the anchor24and folding back it for stitching it at the rear side further than the front end.

The protection cover is made by folding back a narrow rectangular sheet material and by sewing it along a tear seam (not shown) to have a cylindrical shape. The tear seam has a strength to the extent of breaking off when the bag body50is inflated.

The protection cover extends from the end of the webbing21toward the nearest position to the anchor24. The rear end of the protection cover covers the stitched portion between the webbing21and the mesh webbing, and is sewn to the webbing21along the tear seam. The front end of the protection cover covers the front end seam of the mesh webbing; however, it is slightly separated from the anchor24. The front end of the protection cover is stitched to the mesh webbing along the tear seam. Both the tear seams adjacent to the rear end and the front end of the protection cover have a strength to the extent of breaking off when the bag body50is inflated.

According to the embodiment, the anchor24is provided with an inflator holder24battached thereto with bolts24f, so that the inflator23is supported to the anchor24by being embraced around the inflator holder24b.

To the inflator23, the gas introducing duct59is connected. According to the embodiment, the gas introducing duct59is fitted outside the gas nozzle of the inflator23, and by tightening a band52(FIGS. 8aand8b) around the gas introducing duct59from the outside, the gas introducing duct59is connected to the inflator23. Gas is introduced from the inflator23into the bag body50of the lap bag22via the gas introducing duct59.

A harness23a(FIGS. 8aand8b) is connected to an inflator control circuit (not shown) for turning on electricity to an initiator (not shown) of the inflator23. On the basis of a seizing signal from the inflator control circuit, the initiator is started so that the inflator23discharges the gas.

As shown inFIGS. 4 to 6b, the anchor24is attached to an anchor-attaching pedestal base31disposed in the lower part of the B pillar30with a clamp bolt27.

The anchor24is provided with holes24cto be inserted by the bolts24fand a hole24dto be inserted by the clamp bolt27formed therein, in addition to the opening24a.

The anchor24A is also provided with a protrusion24efolded up from its periphery in a claw shape. The pedestal base31is provided with an arc-shaped slot31ato be inserted by the protrusion24eas well as a tapped hole to be screwed by the clamp bolt27. The slot31ais an elongated hole extended in an arc shape to have the same radius from the center of the tapped hole for the clamp bolt27. The protrusion24eis movable along the slot31afrom its one end to the other end.

A slip washer27a(FIG. 4a) is interposed between the bolt head of the clamp bolt27and the anchor24. Between the anchor24and the pedestal base31, a slip washer (not shown) is also interposed so that the anchor24is rotatably attached to the pedestal base31. The anchor24is swingable within the range of the protrusion24emovable within the slot31a.

The anchor24, the inflator23, and the lower part of a B pillar are covered with a B pillar cover32. The lower portion of the lap bag22upwardly extended from the B pillar cover32is embraced around a belt cover33.

As shown inFIG. 5, the lower portion of the B pillar cover32is bulged toward the vehicle chamber, and an opening32ais formed on the upper surface of the B pillar cover32. The lap bag22is inserted into the opening32a. The lower portion of the belt cover33is fitted into the opening32a. The belt cover33is provided with flanges33fand33gformed on the outer surface of its lower portion, and the marginal part of the opening32ais interposed between the flanges33fand33g.

On the rear side of the belt cover33, the marginal part of the opening32ais clamped between the flanges33fand33g. The space between the flanges33fand33gis increased toward the front side of the belt cover33, so that the belt cover33is swingable in the front-back direction integrally with the anchor24and the lap bag22.

As shown inFIGS. 3 and 6b, the belt cover33is provided with tear lines33aformed thereon, and when the lap bag22is inflated, the lap bag22, as shown from FIG.6atoFIG. 6b, is cleft along the tear lines33a.

As shown inFIG. 2, on the side of the seat10adjacent to the chamber center, a buckle device40is provided for latching the tongue28. The buckle device40may be attached to the seat10or may also be arranged on the vehicle chamber floor F.

Although not shown, various sensors are provided on a vehicle having the vehicle-occupant restraint system20mounted thereon for detecting a collision (including a side impact, it is the same in the below) of the vehicle or for foreknowing a collision or a lateral turning of the vehicle (both the detection sensor and the foreknowing sensor may also be provided). The inflator control circuit starts the initiator of the inflator23based on the detection or foreknown signal from these sensors.

In the vehicle-occupant restraint system configured in such a manner, the end of the lap bag22is attached to the B pillar30serving as a vehicle side member via the anchor24, so that the installation of the lap belt onto the vehicle side member is simplified.

According to the embodiment, the inflator23is integrated with the anchor24, so that the inflator23can also be easily attached to the B pillar30.

The anchor24and the inflator23are also covered with the B pillar cover32, improving also the appearance.

According to the embodiment, when the front end of the lap bag22is swung in the front-back direction of the vehicle body due to the shift of the seat in the front-back direction or the bending forward of an occupant, the anchor24and the belt cover33also swing in arrow θ direction ofFIG. 4aby following the lap bag22. Therefore, the twisting and the sliding produced at the end of the lap bag22, in the vicinity of the opening24ain particular, can be alleviated. As a result, the strength and the wear resistance required for the lap bag22are relaxed.

The operation of the vehicle-occupant restraint system is as follows.

When a collision or a lateral turning of the vehicle is detected or foreknown by the sensor, on the basis of the detection signal or the foreknown signal, a seizing signal from the inflator control circuit is entered in the initiator of the inflator23so as to start the initiator for discharging gas from the inflator23. The gas from the inflator23is introduced into the lap bag22(into the bag body50) via the duct29, so that the lap bag22(the bag body50) is inflated while cleaving the belt cover33and the protection cover (not shown).

At this time, along with the inflation of the bag body50of the lap bag22, the mesh webbing surrounding the bag body50is also inflated; since the mesh webbing is knitted so that it is scarcely elongated in the longitudinal direction while can elongate flexibly in width and expanding directions, when the mesh webbing is inflated, its length is shortened. Thereby, tension is applied to the webbing21, so that the lap belt portion21a(including the lap bag22) is brought into tight contact with the body of an occupant so as to securely restrain the occupant to the seat10while the impact applied to the lower back or the abdominal part of the occupant is absorbed by the inflated lap bag22.

The embodiment described above shows an example of the present invention, so that the invention is not limited to the embodiment. For example, the protrusion24amay also be provided in the pedestal base31and the slot31amay also be provided in the anchor24. Instead of the slot31a, protrusions may be provided in vicinities of both ends of the slot31a, so that the protrusion24eis movable between the projections for restricting the swingable range.

According to the embodiment, the anchor24is attached to the lower portion of the B pillar30; alternatively, it may be arranged on the vehicle chamber floor F.

According to the embodiment, the inflator23is attached to the anchor24; alternatively, it may also be attached to the pedestal base31, the seat frame11, or the vehicle cabin floor14F.

FIGS. 9a,9b, and10show an example of the above in that a cylindrical gas inlet61extended from the lap bag22is connected to the inflator23via a pipe62. An anchor24A is swingably attached to the seat frame11with the clamp bolt27. A projection24e(seeFIG. 10) of the anchor24is inserted into a slot (not shown) provided in the seat frame11so that the swinging range is restricted.

The inflator23held by an inflator holder64is attached to the seat frame11with bolts65. Other configurations of the vehicle-occupant restraint system shown inFIGS. 9a,9b, and10are the same as those of the embodiment described above, so that like reference characters designate like common components.

According to the embodiment shown inFIGS. 9a,9b, and10, the inflator23may also be held on the anchor24A.

FIGS. 11 and 12show that a bracket70is arranged on a vehicle body floor80, and the anchor24is swingably attached to the bracket70with the clamp bolt27while the swinging range of the anchor24is restricted with the protrusion24eand a slot71.

The inflator23is attached to the bracket70via an inflator holder72and bolts73. The lap bag22is connected to the inflator23via the gas inlet61and the pipe62.

The bracket70is covered with a B pillar cover74. The lap bag22is inserted into an opening74aof the B pillar cover74. The vicinity of the end of the lap bag22is covered with the belt cover33. The configurations of the belt cover33are the same as those of the embodiment described above, so that like reference characters designate like common components.

The bracket70is provided with a hook part75with a crank-shaped section formed at the rear end and a projection76formed at the front end. The hook part75is brought into engagement with an opening81of the floor80while the projection76is brought into engagement with an opening82of the floor80so as to position the bracket70. The bracket70is fixed to the B pillar30with a bolt77.

According to the embodiment, the vehicle-occupant restraint system for a driver's seat is exemplified; the present invention can be obviously incorporated in other seats such as a passenger's seat.

The present invention has been described in detail with a specific embodiment; however, it is apparent to one skilled in the art that various modifications can be made without departing from the spirit and scope of the present invention.

This application is made based on Japanese Patent Application filed on 16thday of Dec. 2005 (Japanese Patent Application No. 2005-363692) and its whole application can be incorporated-by reference.