Airbag for knee airbag apparatus

An airbag for a knee airbag apparatus which is rapidly deployed upward along a shape of an instrument panel includes a front panel; and a rear panel coupled to the front panel to form an inflation chamber. The front panel neighbors to the instrument panel and the rear panel neighbors to knees of a passenger when the airbag is inflated. The rear panel includes a wrinkle portion which is deployed at a position corresponding to a housing connecting portion to which the instrument panel and a rear end of the housing neighbor when the airbag is inflated, so that an additional inflation chamber is formed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 U.S. National Stage of International Application No. PCT/KR2014/002685, filed Mar. 28, 2014, which claims the benefit of Korean Patent Application No. 10-2013-00038121, filed Apr. 8, 2013. The entire disclosures of the above applications are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a knee airbag apparatus. More particularly, the present invention relates to an airbag for a knee airbag apparatus which is manufactured to allow a rear panel of the airbag to have a length longer than that of a front panel, so that the airbag deploys upward along an instrument panel.

BACKGROUND ART

A knee airbag apparatus protects legs of a passenger upon a collision by deploying an airbag between an instrument panel and the lower legs, for example, tibias of the passenger.

The airbag prevents a passenger from colliding with the instrument panel at a high acceleration upon a vehicle collision. The instrument pane is made of a high stiffness material so a high force is applied to the legs of the passenger when the passenger collides with the instrument panel at a high acceleration.

The airbag allows the passenger to collide with the airbag instead of the components of a vehicle, so that relatively low impact is applied to the passenger.

The knee airbag apparatus, which is located behind the instrument panel, is configured to be deployed through a door or chute placed on a surface of the instrument panel.

To the contrary, the knee airbag apparatus, which is installed at a low portion of the instrument panel, is deployed toward the bottom of the vehicle at the first stage, and then, is deployed upward along the instrument panel of the vehicle (this knee airbag apparatus is called a low mounting knee airbag apparatus).

Thus, the study and research have been performed on various deployment paths of the knee airbag apparatus for effectively deploying the airbag of the knee airbag apparatus toward an upper portion of a vehicle along a shape of an instrument panel.

DISCLOSURE OF INVENTION

Technical Problem

Accordingly, it is an object of the present invention to provide an airbag for a knee airbag apparatus in which, when the airbag is deployed, an airbag is deployed more rapidly toward an upper portion of a vehicle by inducing the airbag to be stood near a portion at which a housing and an instrument panel are coupled to each other.

Further, it is another object of the present invention to provide an airbag for a knee airbag apparatus which utilizes a margin generated in fabricating an airbag without employing an additional member as a deployment guide member for inducing an airbag deployment upward.

Solution to Problem

According to the present invention, there is provided an airbag for a knee airbag apparatus. The airbag for a knee airbag apparatus includes a front panel; and a rear panel coupled to the front panel to form an inflation chamber, wherein the front panel neighbors to the instrument panel and the rear panel neighbors to knees of a passenger when the airbag is inflated, and the rear panel includes a wrinkle portion which is deployed at a position corresponding to a housing connecting portion to which the instrument panel and a rear end of the housing neighbor when the airbag is inflated, so that an additional inflation chamber is formed.

The front and rear panels are fabricated as one piece such that the front and rear panels face each other about a first folding line, a vertical length from the first folding line to an upper end of the front panel is shorter than a length from the first folding line to an upper end of the rear panel, the front and rear panels include a front inclined end and a rear inclined end, respectively, which are gradually inclined outward from the first folding line to upper ends of the front and rear panels, and the front and rear panels include front and rear flaps protruding outward from the front and rear inclined ends and symmetrical to each other about the first folding line.

The front and rear flaps include lower ends placed in the front and rear panels when the front and rear flaps are folded in a horizontal direction at a position spaced apart from the first folding line; and side ends corresponding to the front and rear inclined ends.

The airbag includes a first sewing line for sewing lower portions of the front and rear panels folded about the first folding line; a second sewing line connected to the first sewing line for sewing lower ends of the front and rear flaps; and a third sewing line formed by sewing the front and rear panels along peripheries of the front and rear panels after lower portions of the front and rear panels sewed along the first and second sewing lines are folded onto a top surface of the front panel and upper ends of the front and rear panels are aligned to each other to form a second folding line.

The first sewing line is sewed in parallel with the first folding line, such that the first sewing line crosses the third sewing line.

The front and rear panels are fabricated as one piece such that the front and rear panels face each other about a folding line, a vertical length from the folding line to an upper end of the front panel is shorter than a vertical length from the folding line to an upper end of the rear panel, the wrinkle portion is implemented by folding a lower portion of the rear panel to allow an upper end of the front panel to be aligned with an upper end of the rear panel, and both sides of the wrinkle portion are fixed by a sewing line formed along peripheries of the front and rear panels.

The front panel has a vertical length equal to a vertical length of the rear panel, and the rear panel includes a cutting line formed in a horizontal direction and an additional panel connected to a periphery of the cutting line to form the wrinkle portion.

When the airbag is inflated, the airbag is initially deployed toward a bottom of the vehicle and then deployed upward between the instrument panel and the knee of the passenger.

Advantageous Effects of Invention

As described above, according to the present invention, the airbag of the low mounting knee airbag apparatus includes a deployment plane concaved toward a position corresponding to the connecting portion between the instrument panel and the housing, so that the upward deployment of the airbag can be rapidly induced.

According to the present invention, the airbag of the low mounting knee airbag apparatus can induce the upward deployment of the airbag by using the margin and the sewing lines of the front and rear panels.

In addition, the number of components and the fabrication cost can be reduced, the fabrication method can be simplified, and the airbag which induces the airbag to be effectively stood upward can be fabricated.

MODE FOR THE INVENTION

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to accompanying drawings. However, the present invention is not limited to the following embodiments, but various modifications may be realized. The present embodiments are provided to make the disclosure of the present invention perfect and to make those skilled in the art perfectly comprehend the scope of the present invention.

In the following description, directional terms described below, such as “upper direction”, “lower direction”, “forward direction”, and “rearward direction”, will be defined based on an airbag housing in a state that the airbag housing is coupled to a low portion of an instrument panel. That is, a direction toward the roof of a vehicle is defined as an upper direction (U), a direction toward the bottom of a vehicle is defined as a lower direction (L), a direction toward a passenger is defined as a rearward direction (R), and a direction toward a front of a vehicle is defined as a forward direction (F).

FIG. 1is a longitudinal sectional view showing a folded state of an airbag of a knee airbag apparatus according to an embodiment of the present invention.

Referring toFIGS. 1 and 2, the knee airbag apparatus1is installed at a low portion of an instrument panel2.

The Knee airbag apparatus1includes an airbag100, an inflator for supply gas to the airbag100upon collision of a vehicle, an airbag housing5for receiving the airbag100and the inflator3, and a door7for covering an opening5ain the airbag housing5.

The airbag100includes a front panel110which neighbors on the instrument panel2and a rear panel130which neighbors on low legs L of a passenger when the airbag100is inflated.

A vertical length Lf of the front panel130is shorter than a length Lr of the rear panel130. Thus, when the front and rear panels110and130are coupled correspondingly to each other, a wrinkle portion131, which is unfolded out when inflating the airbag, is formed at the rear panel130.

The wrinkle portion131is formed at a low portion of the rear panel130in a horizontal direction such that the wrinkle portion131is unfolded near a housing connecting portion2ato which the housing5and the instrument panel2are coupled.

A plurality of tethers (for example, first to third tethers151to155) are connected between the front and rear panels110and130and are spaced apart from each other by a predetermined gap such that the forward and rearward deployments of the airbag110may be restrained.

Preferably, when the airbag100is inflated, the first tether151is unfolded from a portion2a(hereinafter, referred to as housing connecting portion) to which a rear end5aof the housing5and the instrument panel2neighbor, toward the bottom of the vehicle in a substantially vertical direction, and the second tether153is unfolded from the portion2a(hereinafter, referred to as housing connecting portion) to which the rear end5aof the housing5and the instrument panel2neighbor, toward a low legs L of a passenger in a horizontal direction.

That is, one end of the first tether151may be coupled to one position of the front panel110corresponding to a front end of the housing connecting portion2athrough a first tether sewing line151a, and one end of the second tether153may be coupled to another position of the front panel110corresponding to a rear end of the housing connecting portion2aspaced apart from the first tether sewing line151aby a predetermined distance.

A middle portion111of the front panel110which is connected between the first and second tethers151and152as described above performs a function of a hinge portion of deploying the airbag100upward and slope-wise along the shape of the instrument panel2.

Reference numeral155adenotes a third tether sewing line which allows the third tether155to be coupled to the front panel110.

The knee airbag apparatus1may be a low mounted knee airbag apparatus which is installed at a low portion of the instrument panel2of driver and passenger seats to allow the airbag100to be deployed upward after the airbag100is initially deployed toward the bottom of the vehicle.

In addition, the knee airbag apparatus1may be installed below a steering wheel at a driver side or at various positions such as a rear side of the vehicle.

FIG. 3is a perspective view showing a deployment state of the knee airbag apparatus according to an embodiment of the present invention.FIG. 4is a sectional view taken along line4-4ofFIG. 3.

Referring toFIGS. 3 and 4, the airbag100includes a front panel110having an inflator insertion hole113and a rear panel130having a shape corresponding to the front panel110and the wrinkle portion131formed by folding a portion of a low portion thereof in a horizontal direction.

The front and rear panels110and130are formed of one piece by folding the one piece having a substantially corresponding shape about a first folding line F1in a central portion of them.

The first folding line F1corresponds substantially to low ends115and135of the front and rear panels110and130.

The airbag100includes a firs sewing line161formed by sewing low portions of the front and second panels110and130which are overlapped by folding the front and second panels110and130about the first folding line F1, and a second sewing line162which extends from the first sewing line161and is formed by sewing the front and rear panels110and130in parallel with the first folding line F1.

In the airbag100, the firs folding line F1is positioned on the top surface of the front panel110by folding the low portions of the front and rear panels110and130upward to the front panel110, the second folding line F2is formed in the rear panel130by fitting the upper end of the rear panel130to the upper end of the front panel110, and then, a third sewing line163is formed by sewing the front and rear panel110and130along peripheries of the front and rear panel110and130.

The second folding line F2corresponds substantially to a low end131aof the wrinkle portion131of the rear panel130.

A cross point C is formed at a position corresponding to that of the wrinkle portion131by crossing the second and third sewing lines162and163. The cross point C performs a function of a hinge point of guiding the airbag100to be deployed upward according to the shape of the instrument panel2when the airbag100is inflated (referring toFIG. 2).

A deployment guide member140, which guides the airbag100to be stood upward, may be additionally provided on a portion at which the second sewing line162of the front and rear panels110and130are formed.

The deployment guide member140may be implemented by using the seam margin M formed at a portion, on which the second sewing line162of the front and rear panels110and130is formed.

Hereinafter, a method, which fabricates the airbag of the knee airbag apparatus configured above, will be described in more detail.

FIGS. 5ato 10bare views showing a process of fabricating an airbag of a low mounting airbag apparatus according to an embodiment of the present invention. The tethers will be omitted from each sectional view.

In the following description, the directional terms, such as “upper end”, “lower end”, “vertical direction”, “horizontal direction” and the like will be defined as follows. In detail, in a state that the non-inflated airbag is unfolded on a plane, a portion adjacent to a portion connected to an inflator is defined as a lower portion, an end of the lower portion is defined as a lower end, a portion facing the lower portion is defined as an upper portion, an end of the upper portion is defined as an upper end, a direction parallel with the upper end of the airbag is defined as a horizontal direction, and a direction perpendicular to the horizontal direction is defined as a vertical direction.

Referring toFIGS. 5aand 5b, the front and rear panels110and130constituting the airbag100are formed of one piece by folding the one piece about the first folding line F1provided at the substantially central portion of the front and rear panels110and130

The front panel110has a vertical length Lf from the first folding line F1to the top end of the front panel110, and the rear panel130has a vertical length Lr from the first folding line F1to the top end137of the rear panel130.

The vertical length Lr of the rear panel130is longer than the vertical length Lf of the front panel110so that the rear panel130has the wrinkle portion131.

The front and rear panels110and130have a front inclined end114and a rear inclined end134which are gradually inclined upward at low edges of them. Therefore, the front and rear panels110and130are substantially formed in a trapezoid shape.

The front and rear panels110and130include front and rear flaps112and132which are protruded from the front and rear inclined ends114and134to an outside and are symmetrical to each other about the first folding line F1.

The front and rear flaps112and132include low ends112aand132aplaced in the front and rear panels110and130when the front and rear panels110and130are folded at a place spaced apart from the first folding line F1by a predetermined distance, and side ends112band132bcorresponding to the front and rear inclined ends114and134.

Preferably, the low ends112aand132aof the front and rear flaps112and132are formed to be inclined toward the upper ends of the front and rear panels110and130.

Referring toFIGS. 6aand 6b, ends of the first to third tethers151,153and155are connected to inner surfaces of the front and rear panels110and130through the first to third tether sewing lines151a,153aand155a.

Although the state of connecting the first to third tethers151,153and155to the front panel110is only shown in the drawings for easy description, the opposite ends of the first to third tethers151,153and155are connected to the rear panel130in a similar manner.

Referring toFIGS. 7aand 7b, the front panel110overlaps the rear panel130by folding the front panel110on the inner surface of the rear panel130along arrow A with respect to the first folding line F1, so that the front and rear flaps112and132are overlapped.

The vertical length Lr of the rear panel130is longer than the vertical length Lf of the front panel110, so that the top end137of the rear panel130is located at a higher position than that of the top end117of the front panel110.

Referring toFIGS. 8aand 8b, both sides of the low portions of the front and rear panels110and130overlapped through the first sewing line161are connected to each other, and the second sewing line162extending from the first sewing line161is formed in the front and rear flaps112and132so that the front and rear flaps112and132are combined with each other. The second sewing line162is formed in parallel with the first folding line F1substantially in a horizontal direction.

Continuously, the low portions of the front and rear panels110and130are folded in the direction of arrow B with respect to a virtual line V denoted over the second sewing line162, so that the first folding line F1is placed on the external top surface of the front panel110.

Referring toFIGS. 9aand 9b, in the state that the low portions of the front and rear panels110and130are folded with respect to the virtual line V, the rear panel130is allowed to move such that the top end117of the front panel110corresponds to the top end137of the rear panel130.

Thus, the rear panel130is folded under the virtual line V so that the second folding line130is formed. The second folding line F2serves as the bottom end131aof the wrinkle portion131shown inFIG. 4.

Referring toFIGS. 10aand 10b, the third sewing line163is formed by sewing them from one side of the second folding line F2to on opposite side of the second folding line F2along the edges of the front and rear panels110and130.

The cross point C is formed by crossing the third sewing line163and the second sewing line162formed at the front and rear flaps112and132, so that the third sewing line163performs the function of a hinge for guiding the airbag100to allow the airbag100to be deployed upward when the airbag100is inflated.

The margin M extends toward the top ends of the front and rear panels110and130so that the bottom ends of the front and rear flaps112and132, in which the second sewing line162is formed. The margin M extends from the cross point C at which the first and third sewing lines162and163are crossed, by a predetermined length H.

Therefore, when the airbag100is inflated, the margin M pulls the airbag100toward the instrument panel2, the margin M performs a function of the deployment guide member of guiding the airbag100to be deployed rapidly and upward.

FIG. 11ais a front view showing an airbag according to another embodiment of the present invention.FIG. 11bis a sectional view taken along line11b-11bofFIG. 11a.

Referring toFIGS. 11aand 11b, an airbag200includes a front panel210and a rear panel230having a wrinkle portion231.

Both sides of the wrinkle portion231are fixed through a sewing line261formed by sewing the front and rear panels210and230along peripheries of the front and rear panels210and230after overlapping the front and rear panels210and230.

FIG. 12is a development view of the airbag200.

Referring toFIG. 12, the airbag200includes the front and rear panel210and230formed of one piece by folding the one piece having a substantially corresponding shape about a folding line F3in a central portion thereof.

The vertical length Lr from the folding line F3to the top end237of the rear panel230is longer than the vertical length Lf from the folding line F3to the top end217of the front panel210.

A portion231of the rear panel230of the airbag200is folded in zigzag to form the wrinkle portion231, and a sewing line261is formed by sewing the front and rear panels210and230along the peripheries of the front and rear panels210and230after the front and rear panels210and230are overlapped by folding the front panel210in the direction of arrow D.

The sewing line261is formed by simultaneously sewing both sides of the wrinkle portion231so that both sides of the wrinkle portion231are fixed.

FIG. 13is a development view showing a knee airbag according to still another embodiment of the present invention.

Referring toFIG. 13, the airbag300includes the front and rear panel310and330formed of one piece by folding the one piece having a substantially corresponding shape about a folding line F3in a central portion thereof.

The vertical length Lr from the folding line F3to the top end237of the rear panel230is equal to the vertical length Lf from the folding line F3to the top end217of the front panel210.

A cutting line331is formed in the rear panel330in a horizontal direction and an additional panel340is coupled to the rear panel330around the cutting line331.

A wrinkle portion is formed in the additional panel340in the state that the airbag300is folded, and an inflation gas, which is provided into the airbag300when the airbag300is inflated, is exhausted through the cutting line331, so that the additional panel340is additionally inflated by the exhaust pressure. Thus, the deployment length of the rear panel330is substantially longer than the deployment length of the front panel310.

As a result, the time taken to apply tension to the front panel310is shorter than the time taken to apply tension to the rear panel330, so that the airbag is rapidly deployed toward the upper portion of the vehicle along the shape of the instrument panel.

The wrinkle portion formed by the additional panel340may be in the state that the wrinkle portion is inserted into the airbag300while being folded. To the contrary, the wrinkle portion may be in the state that the wrinkle portion is drawn out of the rear panel330through the cutting line331.