JPH07110600B2 - Air bag device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag device used for ensuring safety when driving a vehicle.

[0002]

2. Description of the Related Art In order to protect an occupant such as an automobile from the risk of a secondary collision (the body of the occupant colliding with the vehicle body due to inertia), a console box in front of a seated occupant, a vehicle body fixing portion such as the back of a seat back, or driving As an air bag device attached to a central portion of a steering wheel in front of a seat, an air bag which is usually attached in a folded state so as to cover an inflator is covered with an emergency rupturable deployable cover member called a module cover. Many are used.

The first conventional example of this type of air bag device
A description will be given with reference to FIGS. 1 to 14.

The airbag device 50 shown in FIGS. 11 and 12 is attached to a central portion of a steering wheel 30 provided on a vehicle body of a passenger car or the like. That is, the airbag device 50 is attached so as to close a hollow box-shaped cover member 51 that is ruptured and expanded to be in an open state in an emergency such as a collision, and a lower opening of the cover member 51. A mounting plate 52 that forms a storage space for an air bag 53, which will be described later, inside the cover member 51.
And an inflator 54 having a gas ejection hole 54a arranged on the side of the mounting space of the mounting plate 52.

A bracket (not shown) provided on the mounting plate 52 is fixedly arranged at the center of the steering wheel 30.

The cover member 51 is shown in FIG.
As shown in (b) and (c), it is formed in a horizontally long shape in order to secure a field of view of an occupant's instrument panel and a storage space for the air bag 53. Further, on the inner wall side of the facing surface portion 51a of the cover member 51 facing the occupant,
As shown in FIGS. (B) and (c), the concave grooves 55a, 55b, 5
6 is formed such that these shapes are H-shaped,
Further, the upper and lower end portions 51b, 51 of the cover member 51 are
c and the mounting plate 5 at the left and right ends 51d and 51e
The joint with 2 is formed to have a smaller plate thickness than the other portions.

In an emergency such as a collision, gas is ejected from the inflator 54 to the air bag 53 housed in the cover member 51, whereby the air bag 53 is rapidly expanded and the recessed grooves 55a, 55b, 5
The cover member 51 is broken at the portion 6. In this state, the left and right end portions 51d and 51e respectively develop to the left and right in FIG. 11 using the joint portion with the mounting plate 52 as a fulcrum, and the upper surface portion of the opposing surface portion 51a which is broken at the groove 56 as a boundary and The upper surface portion 51b is expanded toward the upper side in FIG. 11 by using the joint portion with the mounting plate 52 as a fulcrum and is broken at the concave groove 56 as a boundary.
The lower side portion and the lower side portion 51c are adapted to expand downward in FIG. 11 with the joint portion with the mounting plate 52 as a fulcrum.

In the following description, the upper portion and the upper portion 51b of the facing surface portion 51a are referred to as the upper flap 60a, and the lower portion and the lower portion 51c of the facing surface portion are referred to as the lower flap 60b.

Here, a conventional example of a folding method of the air bag 53 housed in the cover member 51 will be described with reference to FIGS. 13 (a) to 13 (d). In the actual airbag, the gas ejection holes 5 of the inflator 54 are
Although it is formed in a circular bag shape as a whole in order to surround 4a, its details are omitted here and only the folding shape is described.

First, as shown in FIG. 13 (a), the air bag 53 is arranged so as to be in a flat state, that is, in a circular shape. Next, as shown in FIG. 13 (b), the lower piece 53a is folded back to the upper side at a position where the diameter becomes approximately ⅔ of the diameter. Further, as shown in FIG. 13 (c), the upper piece 53b is folded back to the upper side of the lower piece 53a with a position at which the diameter becomes approximately 1/3 as a boundary. Further, from the state shown in FIG. 13 (c), left and right side pieces 53c, 53d
Are folded in a symmetrical arrangement to form an air bag 53 in a four-fold state as shown in FIG. 13 (d).

In FIGS. 11 and 12 (a),
13 shows a state in which the air bag 53 as shown in FIG. 13 (d) is housed in the cover member 51.

Next, the deployed state of the air bag 53 in an emergency will be described with reference to FIGS. 14 (a) and 14 (b).

When an emergency such as a collision occurs, the inflator 5
When gas is ejected from the air bag 53 into the air bag 53, the expansion force acting on the air bag 53 causes the cover member 51 to move.
The recessed grooves 55a, 55b, and 56 are broken, and at this moment, the upper flap 60a and the lower flap 60b are located on the upper and lower sides, respectively, on both left and right side portions 51, as shown in FIG. 14 (a).
d and 51e rapidly expand to the left and right respectively.
At the same time, the left and right side pieces 53c and 53d of the air bag 53 are moved to the 14th position by the expansion force acting on the air bag 53.
It unfolds to the left and right as shown in FIG. Furthermore, the expansion force continuously acting on the airbag 53 causes the lower piece 53 to move.
a, the upper piece 53b is expanded to the lower side and the upper side, respectively, as shown in FIG. 14 (b), and then rapidly expanded.
The inflated air bag 53 is interposed between the steering wheel 30 and the occupant, and the safety of the occupant is ensured.

However, the conventional air bag device 5
At 0, the deployment directions of the upper and lower flaps 60a and 60b and the initial deployment direction of the airbag 53 (deployment directions of the left and right side pieces 53c and 53d) do not match, so that the following problems occur. is there.

When an inflating force acts on the air bag 53 due to the ejection of gas from the inflator 54, the inflating force first causes the left and right side pieces 53c and 53d to deploy the left and right side portions 51d and 51e of the cover member 51, respectively. . However, since the left and right side portions 51d and 51e are thicker than the upper and lower flaps 60a and 60b, the concave groove 55
The expansion force required for fracture of a and 55b becomes large. This also means that when the air bag 53 is inflated, the friction with the inner wall of the air bag 53 increases, and the damage of the air bag due to friction increases.

Further, due to the difference in the deploying direction as described above, the time until the inflation of the air bag 53 is completed becomes long, and the initial deploying direction of the left and right side pieces 53c and 53d is the leftward and rightward direction with respect to the occupant. Therefore, there is a high possibility that the original function of this device, which is to interpose the inflated airbag 53 between the occupant's abdomen and the steering wheel 30, is impaired.

[0017]

As described above, in the conventional air bag device, a large inflating force is required when inflating the air bag, and the air bag is easily scratched, and the inflation is completed. There is a problem that the time is long and the function cannot be fully exerted.

Therefore, an object of the present invention is to provide an air bag device which requires only a small inflating force to act on an air bag, is less likely to be damaged, and can be quickly inflated to ensure the safety of an occupant. is there.

[0019]

SUMMARY OF THE INVENTION The present invention is an air bag device for a driver's seat, which is attached to a substantially central portion of a steering wheel facing a seated occupant. An air bag (2) arranged as a folded body so as to surround the gas injection hole of the inflator, and an emergency breakable deployable cover member (51) covering the air bag, the cover member The air bag includes an upper flap (60a) that opens to the upper side of the steering wheel and a lower flap (60b) that opens to the lower side of the steering wheel when the steering wheel is in a straight-ahead traveling posture. In the airbag device having a circular shape when unfolded, the flaps (60a, 6a) on both the upper and lower sides of the cover member are provided. Consistent with fracture deployment direction of the b) and a center line passing through the center point of the air bag and Y, the centerline Y
When X is a center line that is orthogonal to the center line and passes through the center point of the airbag, the airbag has both right and left side pieces of the center line Y along a first folding line parallel to the center line Y. By folding back to the seated occupant side, it becomes a slender elongated shape in the Y direction, and then, both side pieces of the elongated shape on both sides of the center line X are seated along second folding lines parallel to the center line X, respectively. The folded body has an upper piece (2d) and a lower piece (2c), which are housed in the cover member by being folded back toward the occupant and open upward at the initial stage of deployment. Is.

[0020]

Next, the operation of the device having the above construction will be described.

According to this device, since the initial deployment direction of the air bag accompanying the gas ejection from the inflator and the fracture deployment direction of the flap of the cover member are matched, a small expansion force is required, and it is swift and smooth. The air bag is inflated, and the inflated air bag is disposed between the seated occupant and the vehicle body.

[0022]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 8. In the airbag device 1 shown in FIG. 1, those having the same functions as those shown in FIGS. 11, 12 (a), 14 (a) and (b) are designated by the same reference numerals. However, its detailed description is omitted.

The airbag device 1 has a predetermined distance L (eg, 1) on the lower right side of the figure with respect to the central axis C ₀ of the steering wheel 30, that is, on the abdomen side of the occupant.
The central axis C ₁ of the cover member 51 is displaced at a position shifted by about 1 cm.
Is different from the conventional air bag device 50 in that the air bag 2 stored in the cover member 51 in a folded state is different from the folding method shown in FIG.

That is, the air bag system 1 has a bracket (indicated by a chain double-dashed line in FIG. 1) 4 integrated with a mounting plate 52, the center position of which is a distance L from the central axis C _0. The steering wheel 30 is attached to the steering wheel 30 by being fixed to the central portion of the steering wheel 30 while being shifted to the occupant side. In FIG. 1, 6 is an auxiliary cover, and 7 is a rivet for fixing the cover member 51 and the mounting plate 52.

The attachment end of the air bag 2 is
An annular mounting plate 57 on the outer peripheral side of the inflator
Is fixed so as to be joined to the mounting plate 52. Further, in the folded state of the airbag 2, the initial deployment direction thereof coincides with the fracture deployment directions of the upper and lower flaps 60a and 60b of the cover member 51, as described later in detail.

Here, the folded state of the airbag 2 will be described in detail with reference to FIGS. 2 to 7.

The air bag 2 is made of a material that is more flexible than the air bag 53 and has a large degree of folding freedom. Further, in the air bag 2, the center line that coincides with the breaking and deploying direction of both the flaps 60a and 60b is y, and the center line in the direction orthogonal thereto is x.

First, as shown in FIG. 2 (a), the air bag 2 is arranged in a circular shape, and then, as shown in FIG. 2 (b), the left side piece 2a of the air bag 2 is arranged.
Is folded along the center line y at a position on the left side of the center line y by about 1/7 of its diameter, and is folded in the direction of the center line y. Next, as shown in FIG. 2 (c), the left side piece 2
The circular end portion of a is folded back along the center line y at a position that is located on the right side of the center line y by about 1/7 of the diameter of the airbag 2.

Further, as shown in FIG. 2 (d), the right side piece 2b is folded back so as to overlap the upper side of the folding left side piece 2a at the same position as the circular end portion. Then, as shown in FIG. 3 (a), the right side piece 2b is folded back at the same position as the circular end portion so as to overlap with the upper side of the folding left side piece 2a. Note that FIG. 3 (b) shows a state in which the thickness of the side surface of the folded airbag 2 shown in FIG. 3 (a) is omitted.

The side surfaces of the air bag 2 shown in FIGS. 4 (b), 5 (b), 6 (b) and 7 (b) are not shown in the drawing, but the thickness thereof is omitted. ing.

Next, as shown in FIG. 4A, the lower side 2c of the airbag 2 folded in the state of FIG. Approximately 1 /
At a position which is lowered to about 9 and folded back upward along the center line x, the folded back lower piece 2c side is again lowered at the position of the center line x as shown in FIG. 5 (a). Turn back to.

Then, as shown in FIG. 6 (a), the lower piece 2c side is folded back to the upper side at a position of about 1/9 of the diameter. As a result, the lower piece 2c side is folded in a four-layered state below the center line x. In this state,
The circular end of the lower piece 2c projects further upward from the center line x.

Finally, as shown in FIG. 7 (a), the upper piece 2d side is folded so as to have a substantially symmetrical shape with the lower piece 2c side, and the circular end side of the upper piece 2d is made into the lower piece. The air bag 2 is stored inside the cover member 51 in the folded state as shown in FIG.

Next, the operation of the air bag device 1 having the above structure will be described with reference to FIGS. 8 (a), 8 (b) and 8 (c).

The airbag device 1 shown in FIGS. 8 (a), (b) and (c) has a cover member 51 shown in FIG.
Using a cover member 51 having the same size as that of the folded air bag 2 shown in FIG.
It shows a state of being housed inside.

When an emergency occurs such as a collision of the vehicle body with another object, a sensor (not shown) provided on the vehicle body operates and the inflator 54 ejects gas into the air bag 2. The inflating force acting on the air bag 2 in association with the gas ejection causes the upper piece 2d and the lower piece 2c to move upward,
The lower flaps 60a, 60b are pressed against the respective sides, whereby the upper and lower flaps 60a, 60b are fractured and expanded to the upper and lower sides as shown in FIG. 8 (b).

Immediately thereafter, the left-side piece 2a and the right-side piece 2b are expanded to the left and right while pressing the left and right end portions 51d and 51e of the cover member 51, respectively, and quickly become substantially spherical as shown in FIG. 8 (c). It inflates and is interposed between the occupant's abdomen and the steering wheel 30, as shown in FIG. Then, in this case, the center line C ₁ of the cover member 51
Is a distance L from the center line C ₀ of the steering wheel 30.
It is shifted to the abdomen side of the occupant, and the breaking and developing directions of the upper and lower flaps 60a and 60b coincide with the initial developing directions of the upper piece 2d and the lower piece 2c. Therefore, the deployment of the airbag 2 rises quickly, and as shown in FIG. 9, the upper piece 2d and the lower piece 2c are deployed between the abdomen of the occupant and the steering wheel 30 at an early stage, which causes a collision or the like. Before the occupant moves to the steering wheel 30 side and collides with the steering wheel 30, the inflation of the airbag 2 can be terminated, and the original function of the airbag 2 can be fully exerted.

Further, since the air bag 2 is folded in the above-mentioned state and housed in the cover member 51, when the air bag 2 having the same volume as that of the conventional air bag 53 is used, the occupied area thereof. 8 is smaller than the area occupied by the conventional air bag 53 as shown in FIG. 8 (a), which means that when the same cover member 51 is used, the air bag 2 having a larger volume is covered. It means that it can be housed in 51, and the safety is further improved.

Further, as described above, since the deploying directions of the upper and lower flaps 60a and 60b and the initial deploying direction of the air bag 2 are the same, the expansion force to the upper and lower flaps 60a and 60b is increased. , That is, the air bag 2
It is possible to reduce the gas pressure in the inside, and thereby, the rubbing of each piece of the air bag 2 and the rubbing between the air bag 2 and the inner wall of the cover member 51 are reduced, and the occurrence of scratches or the like occurring in the air bag 2 is reduced. Can be suppressed.

FIG. 10 shows the relationship between the pressure in the air bag 2 and the time when gas is ejected from the inflator 54 into the air bag 2 with an amount of 88 g of explosives.
It is a graph which shows separately in ° C, +22 ° C, and +85 ° C.

It is needless to say that the present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the gist thereof.

[0042]

According to the present invention described in detail above, the folded state of the air bag is improved, and the initial deployment direction thereof is made to coincide with the deployment direction of the flap, whereby the inflating force acting on the air bag can be reduced. At the same time, it is possible to provide an airbag device capable of enhancing the safety of an occupant while suppressing the occurrence of scratches on the airbag.

[Brief description of drawings]

FIG. 1 is a sectional view showing an apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a folded state of an airbag in the same device.

3A and 3B are configuration diagrams showing an airbag in the same apparatus, FIG. 3A is a plan view showing a folded state of the airbag, and FIG. 3B is a side view showing the airbag with the thickness thereof omitted.

4A and 4B are configuration diagrams showing an airbag in the same apparatus, FIG. 4A is a plan view showing a folded state of the airbag, and FIG. 4B is a side view showing the airbag with the thickness thereof omitted.

5A and 5B are configuration diagrams showing an airbag in the apparatus, FIG. 5A is a plan view showing a folded state of the airbag, and FIG. 5B is a side view showing the airbag with the thickness thereof omitted.

6A and 6B are configuration diagrams showing an airbag in the apparatus, FIG. 6A is a plan view showing a folded state of the airbag, and FIG. 6B is a side view showing the airbag with the thickness thereof omitted.

7A and 7B are configuration diagrams showing an airbag in the apparatus, FIG. 7A is a plan view showing a folded state of the airbag, and FIG. 7B is a side view showing the airbag with the thickness thereof omitted.

FIG. 8 is a plan view showing an inflating process of the airbag in the device.

FIG. 9 is a schematic side view showing a state where the airbag of the device is inflated.

FIG. 10 is a graph showing the relationship between the pressure inside the airbag and time.

FIG. 11 is a plan view showing a state in which a conventional air bag device is attached to a steering wheel.

FIG. 12 is a configuration diagram of a conventional airbag device,
(A) is a top view, (b), (c) is a sectional view showing a cover member, an inflator, and a mounting plate of the device, respectively.

FIG. 13 is a plan view showing a folded state of a conventional airbag.

FIG. 14 is a plan view showing an inflation process of an air bag in a conventional air bag device.

[Explanation of symbols]

 1 Airbag device 2 Airbag 30 Steering wheel 51 Cover member 54 Inflator 60a Upper flap 60b Lower flap

Claims (1)

[Claims] 1. An inflator for a driver's seat, which is attached to a substantially central portion of a steering facing a seated occupant, the inflator ( 54 ) for generating an air bag deployment gas.
And an air bag ( 2 ) arranged as a folded body so as to surround the gas injection hole of the inflator, and an emergency rupturable deployable cover member ( 51 ) covering the air bag, the cover member has a lower flap (60b) to which a steering begins to open the lower side of the upper side flaps (60a) and said steering starts to open on the upper side of the steering in the case in straight posture linearly moving vehicle in an air bag system which is circular in the state the air bag, the unfolded, the upper and lower sides of the flap of the cover member (60a, 60
When the center line which coincides with the fracture deployment direction of b ) and passes through the center point of the airbag is Y, and the center line which is orthogonal to the center line Y and passes through the center point of the airbag is X, the airbag is Is formed into a slender elongated shape in the Y direction by folding back each of the left and right sides of the center line Y along the first folding line parallel to the center line Y toward the seated occupant, and then the center line X The elongated strips on both sides are folded back toward the seated occupant along second folding lines parallel to the center line X, so that they are housed in the cover member and open upward at the initial stage of deployment. Upper piece (2d)
And an air bag device for a driver's seat, characterized in that there is a said folded with the lower piece (2c).