JPH09309395A - Folding method for vehicular air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a folding condition where an air bag can be easily folded in a reversed trapezoid shape or a trapezoid shape, which is suitable to be equipped to the boss part of a three-spooked steering wheel, while being made low in bulk as a whole in such a way that each is corner is prevented from being excessively thickened. SOLUTION: After the right and left parts of an air bag 1 are folded along parallel lines at the side of an occupant so as to be formed into a belt shaped body specified in width, both side portions in the longer direction of the belt shaped body are folded in a rolled shape or a bellows shape, concurrently, a joining part 7 of both the folded side portions is slipped somewhat to one side in the aforesaid longer direction from the center of the air bag so as to allow a portion 8 thin in lap to be provided in the other side of the folded side portions, and furthermore both side portions of the aforesaid portion thin in lap, are obliquely folded in such a way as to be pushed in, so that the whale of the air bag is thereby folded in a reversed trapezoid shape or a trapezoid shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for folding a bag-shaped airbag for a vehicle, which is inflated and inflated by supplying gas therein.

[0002]

2. Description of the Related Art Conventionally, as an air bag device for a vehicle such as a passenger car, particularly for a driver, a folded air bag is a component of an inflator (gas generator) or the like. A unit that is housed in a case together with the unit is housed in the boss of the steering wheel and then assembled.

It is necessary that this air bag should be low in volume so that it can be stored in a limited space, and that it can be instantly inflated during inflation. Particularly, in recent years, an airbag device which is compact in design has been demanded. Therefore, various airbag folding methods have been proposed.

For example, in Japanese Unexamined Patent Publication No. 3-167048, a horizontally long strip is formed by folding the upper and lower portions of a substantially circular airbag along a plurality of fold lines parallel to the vehicle left-right direction on the occupant side. After being formed into a body, the belt-like body is folded from both left and right ends at an inclined angle, and the airbag is folded into a substantially trapezoidal shape and stored in the boss portion of the steering wheel of the automobile.

By the way, in the case of a three-spoke steering wheel in which the boss portion and the rim portion of the steering wheel are connected to three spokes, the boss portion is deformed into a sporty shape, that is, a substantially inverted trapezoidal shape or a trapezoidal shape. The shape of the bag reduces the bag storage space.

In such a case, even if the same folding method as the conventional method is used and the corner portions of the quadrangle are further folded to fold into an inverted trapezoidal shape, the folding height of the corner portions becomes high and they are stored in the boss portion. In this state, the boss cover (pad) may be deformed or the appearance design may be distorted.

In addition, in order to equip a three-spoke type steering wheel, a method has been proposed in which a rectangular corner portion is obliquely folded in a folded state of an airbag to be folded into a substantially inverted trapezoidal shape or a pentagonal shape. (For example,
JP-A-7-89402).

However, the folding method disclosed therein is not preferable because the folding process is troublesome in any case.

The present invention has been made in view of the above, and is provided in a relatively small and inverted trapezoidal or trapezoidal boss portion such as a three-spoke steering wheel in an airbag for a driver. The present invention provides a folding method that can be easily folded into a shape suitable for, for example, an inverted trapezoidal shape or a trapezoidal shape, and can obtain a folded state in which the thickness of a corner portion does not become excessively large. Further, the present invention provides a folding method in which a preferable unfolding behavior can be obtained by folding in a lateral bellows shape and an upside down roll shape.

[0010]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is a method of folding a vehicle airbag that is inflated by being filled with gas. After folding on the occupant side in a bellows shape along parallel fold lines into a belt-shaped body having a predetermined width, (b) folding both side portions in the longitudinal direction of the belt-shaped body on the occupant side into a bellows shape or a roll shape. Together with this, the joint between the two folding parts is slightly shifted from the center of the bag to one side in the longitudinal direction, and the folding end on the other side has a thin overlapping part that does not have a large folding part, (C) Further, it is characterized in that both side corners of the above-mentioned thin overlapping portion are obliquely folded so as to be pushed in, and the whole is folded into an inverted trapezoidal shape or a trapezoidal shape. .

Further, in the above-mentioned folding method, at the time of folding (b), both side portions in the longitudinal direction of the belt-shaped body are folded so as to be wound in a reverse roll shape from the tip portions thereof, and the reverse roll shape of both side portions is formed. The overlapping part of the winding parts of is shifted from the center of the bag to one side by a length of 5 to 25% of the total length of the folded state, and there is no reverse roll-shaped winding part at the folding end of the other side. Set the thin part.

By folding as in the above invention,
The three-spoke steering wheel can be folded into a shape that fits in the storage space inside the boss, that is, an inverted trapezoidal shape or a trapezoidal shape, and the folding procedure is less laborious than in the past. ,
Can be easily folded.

Moreover, since the corner portions overlap and are folded inward at the thin portion, the bulky portion does not become bulky, and the folded portion can be folded as a low bulk.

In particular, as in the second aspect of the present invention, the folded state which is excellent in the expansion behavior at the time of gas generation by the inflator can be obtained by performing the left and right bellows folding in the first step and the upside down roll folding in the second step. .

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of an airbag folded by the method of the first embodiment of the present invention, FIG. 2 is a perspective view of the airbag in a first-stage folded state, and FIG. 3 is a second-stage folded state of the airbag. It is a perspective view of a state. FIG. 4 is a front view from the occupant side of a steering wheel equipped with a folded airbag.

The airbag (1) is accommodated in a case together with airbag device components such as an inflator (gas generator) in a folded state, and a steering wheel (2) is provided.
It is installed in the storage part in the boss part (21) of (0). The storage part in the boss part (21) is a steering wheel (20).
Corresponding to the one having three spokes (22), it has a substantially inverted trapezoidal shape in which both sides are inclined so that the width becomes gradually smaller toward the spokes (22) on the vehicle lower side. Therefore, the storage case (2) for the airbag (1)
4) also has a substantially inverted trapezoidal shape. Therefore, the airbag (1) accommodated therein is folded and accommodated in a substantially inverted trapezoidal shape as shown in FIG. 1 corresponding to the above shape.

The airbag (1) is in the form of a bag, for example, two sheet materials made of resin coating on nylon cloth or the like or two uncoated sheet materials are joined at their peripheral portions by means such as stitching. Is formed in. An opening (2) connected to the inflator side is formed in the sheet material on the inflator side of the two sheet materials. Then, in the event of a vehicle collision or the like, the cover (23) of the boss (21) is caused by the inflation pressure of the airbag (1) that is folded and stored by the gas that is jetted and supplied from the inflator.
Is opened like a door, and the airbag (1) is deployed to the passenger side.

Next, a method for folding the airbag (1) will be described with reference to FIGS.

In the first-stage folding, first, the air bag (1) is flattened and unfolded from the plane circular state shown in FIG. 5 to the left and right portions (around the center line (Y) corresponding to the vertical direction of the vehicle). 1a) (1b), for example, the left part (1
a) is folded toward the inner side along the broken line parallel to the center line (Y) at a position on the left side of the center line (Y) on the occupant side, alternately alternately inward as shown in FIGS. Repeat to fold outward and fold it into a bellows shape. Further, the right part (1b) is also folded in a symmetric bellows shape corresponding to the left part (1a) along a parallel fold line at a position on the right side of the center line (Y), and the whole is shown in FIG. As shown in 2), the belt-like body (3) having the required width is formed in the vehicle vertical direction. The width of the belt-shaped body (3) is set so as to substantially correspond to the width of the storage portion inside the boss portion (21) of the steering wheel (20) in which these are stored.

Next, in the second-stage folding, one side of the upper side portion (4c) and the lower side portion (4d) which are both side portions in the longitudinal direction of the band-shaped body (3) folded as described above. , For example, after folding the lower part (4d) upward as shown in FIG. 12, as shown in FIGS.
The tip (5d) is folded so as to be wound in an inverted roll shape several times. In addition, as for the upper side portion (4c), after being folded downward so as to correspond to the lower side portion (4d), the tip end portion (5c) of the upper side portion (4c) is wound several times in a reverse roll shape, as shown in FIG. And fold it like its full length (L0
) Is folded so as to have a dimension substantially corresponding to the vertical dimension of the storage portion in the boss portion (21) in which it is stored.

At the same time, when the lower side portion (4d) and the upper side portion (4c) are folded, both folding portions, that is, reverse roll-shaped winding portions (6d) (6c). The joint (7) between them,
It is slightly shifted from the bag center (G) to the one upper side in the longitudinal direction, and as shown in FIG. 17 (FIG. 3), the folded end portion of the other lower side portion (4d) is approximately the same as the shifted size. A portion (8) having a small overlapping thickness, which does not have an inverted roll-shaped winding portion, is set within a corresponding dimension (vertical dimension) range.

Here, the two winding portions (6d) (6
c) The dimension (Lx) that shifts the joints (7) from each other from the bag center (G) is set within the range of 5 to 25% of the total length (L0) in the completed folding state, and the overlapped portion (8) is thin. )
(L3) is set to be substantially equal to (Lx). That is, in the folded state shown in FIG.
Let L3 be the total length in the vertical direction when the folding is completed and L3 is the dimension of the thin overlapping portion (8).
/ L0 is set in the range of 0.25 to 0.05.

The size (L1) of the upper winding portion (6c) and the size (L2) of the lower winding portion (6d) are basically (L0-L3) / 2. It is necessary to set the dimension (L2) to be slightly smaller than the dimension (L1) and to fold the folded portion (6c) (6).
It is preferable for making the overlapping thickness of d) substantially the same.

Then, in the next third step of folding, as shown in FIG. 18, both side corner portions of the thin portion (8) having the small overlapping thickness are placed inside the band-shaped body (3) folded as shown in the figure. Fold it in like a gusset, and fold it into an inverted trapezoid. At this time, the inclination angle and the folding dimension of the diagonal folding portions (9a) and (9b) are
It may be set according to the storage unit in which it is stored. In particular, since there is little overlap between both ends of the rolled-in portion (6d), part of the folded-in portions (9a) (9b) is shown in FIG.
Even if it is folded in such a manner as to enter even the region of the rolled-in portion (6d), the overlapping thickness does not become significantly thick.

As described above, the left and right portions (1a) and (1b) of the airbag (1) are folded in a bellows shape as shown in FIG. 2 in the first step, and the longitudinal length of the strip (3) is changed in the next second step. As shown in FIG. 3, both side portions in the direction are shifted to one side and folded in an inverse roll shape to set a thin overlapping portion (8) having no winding portion on the other side. By diagonally folding both side corners of the thin portion (8), an airbag (1) which is entirely folded in an inverted trapezoidal shape as shown in FIG. 1 can be obtained. Moreover, since the slanted folded portions (9a) and (9b) are pushed inward by the overlapping thin portion (8), the folded portion does not become bulky and can be folded as a whole with a low bulk. .

FIG. 19 shows a folded state according to the method of the second embodiment of the present invention. In the second embodiment, the first
Although the left and right parts (1a) and (1b) are bellows-folded in the same step as in the case of the method of the first embodiment described above, in the second step, the above-mentioned reverse roll-shaped rolled-in portion (6c).
Instead of (6d), the upper part (4a) and the lower part (4b) are folded in a bellows shape. Thus, as in Example 1, the upper and lower bellows-like folded portions (16
c) The joint part (7) of (16d) is shifted to the upper part, and a part (8) having a small overlapping thickness is set on the lower side, and both corner parts thereof are diagonally folded as shown in the figure.

Also in this case, the oblique folding portion (9a)
Since (9b) is pushed inward by the overlapping thin portion (8), the whole can be folded in a low bulk.

The folding height and the presser foot of the airbags of Examples 1 and 2 of the present invention by the above-mentioned folding method (Examples 1, 2) and the comparative example products by other folding methods (Comparative Examples 1, 2) When the relationship with the load was measured and compared, the result is as shown in FIG.

Here, the folding dimensions of Examples 1 and 2 are L0 = 150 mm, L1 = 75 mm, L2 = 40 m.
m, L3 = 30 mm, the airbags of Comparative Examples 1 and 2 were in the following folded configurations, and other conditions such as the sheet material and the size of the bag were the same.

Comparative Example 1: In the first step, as shown in FIG. 21, the upper and lower parts (51) (51) are bellows-folded to form a horizontally long strip (5).
3) and then in the second stage, as shown in FIG.
3) The left and right sides are accordion-folded, and the corners (55) are further folded into an inverted trapezoidal shape.

Comparative Example 2: In the first step, the left and right parts were bellows-folded, and in the second step, the upper and lower parts of the vertically long strip were reversely roll-folded so that the joint part of the rolls was positioned in the center of the bag and the lower part The side corners are folded in the same manner as in the present invention.

The pressing load (compression load) and the bag height of the airbag folded as described above were measured by an autograph.

Autograph conditions : Compressed to 490 N at a compression speed of 10 mm / min, maintained for 5 minutes, further set the compression load to 0, and then similarly compressed.

As a result, in Examples 1 and 2, the folding height was low, and the bulky folding was possible.

Although the folding height of the airbag of Example 1 was slightly larger than that of Example 2, the deployment behavior was good. That is, the widening in the left-right and up-down directions was smooth, and as a result, the bag ejection speed became slow. FIG.
Shows the measurement data of the pop-out speed and the distance when the bag is deployed in Examples 1 and 2, where the deployment speed is the pop-out speed to the occupant side when the bag is deployed, and the deployment distance is the occupant side when the bag is deployed. Indicates the pop-out amount of.

[0037]

As described above, according to the folding method of the present invention, the airbag can be easily folded into an inverted trapezoidal shape or a trapezoidal shape, and in particular, the thickness of the diagonally folded corner portion is excessively large. Instead, it can be folded in a low bulk as a whole. Therefore, it is possible to obtain a folded state suitable for mounting on a relatively small and inverted trapezoidal or trapezoidal boss portion such as a three-spoke steering wheel.

In addition, by deploying the first stage to the left-right bellows fold and the second stage to the upside-down reverse roll fold, the expansion behavior at the time of gas generation can be maintained well.

[Brief description of drawings]

FIG. 1 is a perspective view of an airbag folded by a method according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the airbag in a first-stage folded state.

FIG. 3 is a perspective view of a second-stage folded state of the airbag.

FIG. 4 is a front view (A) from a passenger side of a three-spoke steering wheel equipped with a folded airbag, and a schematic perspective view (B) showing a boss portion thereof.

FIG. 5 is an explanatory diagram of a first stage folding process of deploying the airbag.

FIG. 6 is an explanatory diagram of a folding process on one side of the left and right portions of the airbag.

FIG. 7 is an explanatory diagram of a folding process following the previous figure.

FIG. 8 is an explanatory diagram of a folding process following the previous figure.

FIG. 9 is an explanatory diagram of the folding process following the previous figure.

FIG. 10 is an explanatory diagram of the folding process following the previous figure.

FIG. 11 is an explanatory diagram of the folding process on the other side of the left and right portions following the previous figure.

FIG. 12 is an explanatory diagram of a second-stage folding process of the airbag.

FIG. 13 is an explanatory diagram of a folding process following the previous figure.

FIG. 14 is an explanatory diagram of the folding process following the previous figure.

FIG. 15 is an explanatory diagram of a folding process following the previous figure.

FIG. 16 is an explanatory diagram of a folding process following the previous figure.

FIG. 17 is an explanatory diagram of a folding process following the previous figure.

FIG. 18 is an explanatory diagram of a third-stage folding process of folding a corner portion.

FIG. 19 is a perspective view of an airbag folded by the method according to the second embodiment of the present invention.

FIG. 20 is a graph showing the relationship between the folding height and the compressive load of the example product of the present invention and the comparative example.

FIG. 21 is a perspective view of the airbag of the comparative example in a folded state at the first stage.

FIG. 22 is a perspective view of the second-stage folded state.

FIG. 23 is a diagram showing measurement data of the pop-out speed and the distance when the bag is deployed in Examples 1 and 2.

[Explanation of symbols]

 (1) Airbags (1a) (1b) Left and right parts (2) Openings (3) Band (4c) Upper part (4d) Lower part (5c) (5d) Tip part (6c) (6c) Entrained part (7) Joining part (8) Overlapping thin part (9a) (9b) Folding part (16c) (16d) Folding part (20) Steering wheel (21) Boss part (22) Spoke (23) Cover

Claims (2)

[Claims] 1. A method of folding an airbag that is inflated by being filled with gas, comprising: (a) folding the left and right portions of the airbag in a bellows shape along fold lines parallel to each other on an occupant side. After forming a strip with a predetermined width,
(B) Both side portions in the longitudinal direction of the band-shaped body are folded into a bellows shape or a roll shape on the occupant side, respectively, and the joint portion between the two folded portions is slightly displaced from the bag center to the one side in the longitudinal direction, At the folding end on the other side, a thin overlapping portion having no thick folding portion is set, and (c) the both corner portions of the thin overlapping portion are pushed in to be folded diagonally, A method for folding an airbag for a vehicle, characterized by folding the entire body into an inverted trapezoidal shape or a trapezoidal shape. 2. In the folding of (b), both sides of the strip in the longitudinal direction are folded so as to be wound in a reverse roll shape from the tip end thereof, and the reverse roll-shaped wound portions of the both sides are joined together. The part is shifted from the center of the bag to one side by a length of 5 to 25% of the total length of the folded state, and the folded end on the other side has a thin overlapping portion that does not have a reverse roll-shaped winding part. The method for folding an airbag for a vehicle according to claim 1, wherein: