JP7461595B2 - Side airbag device - Google Patents

Description

The present invention relates to a side airbag device.

As shown in Patent Document 1, a vehicle such as an automobile is equipped with a side airbag device. The device includes an airbag and an inflator. The airbag is stored in a folded state. The inflator supplies gas to the airbag when the vehicle is involved in a side collision, etc.

In the event of a side collision of the vehicle, the airbag is deployed and inflated by the supply of gas from the inflator to the airbag. The airbag deploys and inflates from the rear to the front of the vehicle, between the area from the chest to the waist of the occupant seated in the vehicle seat and the body side of the vehicle. In this way, the occupant seated in the seat is protected by the airbag in the event of a side collision of the vehicle.

One such airbag is known from Patent Document 1. This airbag has a partition that divides the interior of the airbag into an upstream inflation section and a downstream inflation section. The upstream inflation section receives gas from an inflator. The downstream inflation section receives gas from the upstream inflation section, and is located in front of the upstream inflation section when the airbag is deployed and inflated. Therefore, gas from the inflator first flows to the upstream inflation section of the airbag, and then flows to the downstream inflation section. This causes the folded airbag to quickly deploy and inflate from the rear to the front of the vehicle.

In addition, due to the above-mentioned gas flow, inside the deployed and inflated airbag, the upstream inflation section becomes higher pressure than the downstream inflation section. In the airbag of Patent Document 1, the partition section that separates the upstream inflation section from the downstream inflation section is made longer in the vertical direction than the deployed and inflated airbag. The lower part of the partition section is bent so as to fold forward relative to the upper part. This positions the lower part of the upstream inflation section of the deployed and inflated airbag in correspondence with the waist of the occupant seated in the seat.

The occupant's hips are a relatively hard part of the occupant's body and have high resistance to impact. During a side collision, the lower part of the upstream inflation section, which is under high pressure, is positioned to correspond to the occupant's hips. This allows the airbag to effectively protect the occupant from a side collision.

JP 2016-120794 A

If an occupant is seated in the correct posture during a vehicle side collision, the lower part of the high-pressure upstream expansion portion of the deployed and inflated airbag will come into contact with the occupant's waist. However, if the occupant is seated in an incorrect posture, the lower part of the upstream expansion portion of the deployed and inflated airbag may come into contact with a part of the occupant other than the waist that is not as hard. In this case, it becomes difficult for the airbag to effectively protect the occupant from a vehicle side collision.

The means for solving the above problems and their effects will be described below.
A side airbag device that solves the above problem supplies gas from an inflator to a folded and stored airbag, thereby deploying and inflating the airbag from the rear to the front of the vehicle between the area from the chest to the waist of an occupant seated in a vehicle seat and the body side of the vehicle. The airbag has a partition that divides the interior of the airbag into an upstream inflation section and a downstream inflation section. The upstream inflation section receives gas from the inflator. The downstream inflation section receives gas from the upstream inflation section, and is located in front of the upstream inflation section when the airbag is deployed and inflated. When the airbag is deployed and inflated, the partition is elongated vertically and is bent so that the lower portion folds rearward relative to the upper portion.

According to the above configuration, the lower part of the partition that divides the interior of the airbag into an upstream inflation part and a downstream inflation part is bent backward relative to the upper part. This causes the lower part of the upstream inflation part of the deployed and inflated airbag to be located behind the occupant's waist, i.e., in correspondence with the backrest of the seat on which the occupant is seated. Therefore, even if the occupant is in an improper posture on the seat, the lower part of the upstream inflation part of the deployed and inflated airbag will not come into contact with the occupant. This prevents the lower part of the upstream inflation part, which is under high pressure, from coming into contact with parts of the occupant other than the waist of an occupant in an improper posture, and thus prevents the airbag from effectively protecting the occupant from a side collision of the vehicle.

In the above-mentioned side airbag device, it is conceivable that the length of the partition in the vehicle width direction when the airbag is deployed and inflated is longer at the lower part than at the upper part of the partition.

With this configuration, when the airbag deploys and inflates, the thickness in the vehicle width direction is thicker at the location corresponding to the lower part of the partition than at the location corresponding to the upper part of the partition. As a result, the thickness in the vehicle width direction of the airbag at the location that contacts the occupant's waist is greater. This improves the airbag's ability to absorb the impact on the occupant's waist during a side collision.

In the above side airbag device, the airbag is stored in a folded state in the backrest of the seat, and is deployed and inflated forward from the backrest when gas is supplied from the inflator. Furthermore, it is considered that the partition is bent relative to the upper part of the partition so that the lower part of the partition extends toward the lower end of the backrest when the airbag deploys and inflates with the backrest in the appropriate position for when the vehicle is traveling.

According to the above configuration, when the airbag is deployed and inflated with the backrest in the proper position for the vehicle being driven, the lower part of the partition part extends toward the lower end of the backrest. As a result, the lower part of the upstream inflatable part of the deployed and inflated airbag is positioned in correspondence with the backrest of the seat in which the occupant is seated.

FIG. 2 is a side view showing the entire side airbag device. FIG. 4 is an enlarged cross-sectional view showing the airbag and its surroundings inside the seat backrest. FIG. 2 is a plan view showing the positional relationship between a seat and a body side portion in a vehicle. FIG. FIG.

Hereinafter, an embodiment of a side airbag device will be described with reference to FIGS.
As shown in Fig. 1, the side airbag device includes an airbag 3 and an inflator 4. The airbag 3 is stored in a folded state inside a seat back 2 of a vehicle seat 1. The inflator 4 is for supplying inflation gas to the airbag 3. The inflator 4 is fixed together with the airbag 3 to a frame 6 located inside the seat back 2. The frame 6 extends substantially vertically along the seat back 2.

In FIG. 1, the airbag 3 is shown by a dashed line in a folded state stored in the backrest 2, while the airbag 3 is shown by a two-dot chain line in a deployed and inflated state supplied with inflation gas from the inflator 4. Incidentally, the size and fixed position of the deployed and inflated airbag 3 as shown by the two-dot chain line in FIG. 1 are such that the upper end of the airbag 3 corresponds to the chest of the occupant P1, while the lower end of the airbag 3 corresponds to the waist of the occupant P1.

Figure 2 shows an enlarged view of the airbag 3 inside the backrest 2. As can be seen from Figure 2, the inflator 4 housed inside the backrest 2 is fixed to the retainer 5 that surrounds it by crimping or the like. Furthermore, the retainer 5 is fixed to the frame 6 together with the airbag 3 in the folded state by bolts 7 and nuts 8 (only the upper one is shown in Figure 2) provided at two levels, one above the other. As a result, the inflator 4 is fixed to the frame 6 of the backrest 2 via the retainer 5, and the airbag 3 is also fixed to the frame 6.

As shown in FIG. 1, the side airbag device also includes a control device 9 that controls the supply of inflation gas to the airbag 3 by the inflator 4, and an impact sensor 10 for detecting a side collision of the vehicle. When an impact due to a side collision is applied to the vehicle, the impact sensor 10 outputs a detection signal to the control device 9. Based on the detection signal from the impact sensor 10, the control device 9 activates the inflator 4 to supply inflation gas to the airbag 3.

When inflation gas is supplied from the inflator 4 to the airbag 3 in a folded state, the airbag 3 unfolds and inflates, and jumps out from the backrest 2 forward (to the right in FIG. 1), leaving the area near the inflator 4 inside the backrest 2. The airbag 3 that jumps out from the backrest 2 unfolds and inflates toward the front of the vehicle (to the right in FIG. 3), as shown by the two-dot chain line in FIG. 3, between the area from the chest to the waist of the occupant P1 seated in the seat 1 and the body side portion 11, such as the door and pillar of the vehicle. The outline arrow in FIG. 3 indicates the direction of impact when an impact is applied to the body side portion 11 due to a side collision of the vehicle.

Next, the airbag 3 will be described in detail.
As shown in Fig. 4, the airbag 3 is formed into a bag shape by folding a piece of fabric 13 in two along a fold line L1, overlapping the pieces in the thickness direction, and joining the edges of the overlapped parts together at the position indicated by the thick dashed line L2. An opening 14 that communicates the inside and outside of the airbag 3 is formed in the vertical center of the airbag 3 near the fold line L1. A retainer 5 (inflator 4) can be inserted into the airbag 3 through this opening 14. A pair of upper and lower mounting holes 15 are formed in one of the parts of the fabric piece 13 that are folded in two along the fold line L1 and overlapped in the thickness direction, and that is located above the opening 14. These mounting holes 15 are for attaching the rear end of the airbag 3 (the left end in Fig. 4) to the frame 6 of the backrest 2 (Fig. 2).

The retainer 5 (inflator 4) inserted into the airbag 3 through the opening 14 is fixed to the frame 6 (Fig. 2). At this time, the bolt 7 of the retainer 5 is passed through the mounting hole 15 of the airbag 3. The airbag 3 is fixed to the frame 6 together with the retainer 5 using the bolt 7 and nut 8 (Fig. 2). The airbag 3 is fixed to the frame 6 in such a way that the part of the airbag 3 away from the retainer 5 is positioned on the front side of the vehicle (the right side in Fig. 4). The upper end of the inflator 4 fixed to the retainer 5 is provided with an ejection part 20 that ejects inflation gas.

The airbag 3 has a partition 21. The partition 21 is disposed between the folded cloth piece 13. The partition 21 is formed in a sheet shape folded in two, and serves to divide the interior of the airbag 3 into an upstream inflation section 22 and a downstream inflation section 23. The upstream inflation section 22 receives gas from the inflator 4. The downstream inflation section 23 receives gas from the upstream inflation section 22, and is positioned in front of the upstream inflation section 22 when the airbag 3 is deployed and inflated, as shown by the two-dot chain line in FIG. 1.

The partition 21 is designed to be longer in the vertical direction when the airbag 3 is deployed and inflated with the backrest 2 in the appropriate position for the vehicle to be in motion (double-dashed line in FIG. 1). In this state, the upper part of the partition 21 extends substantially parallel to the frame 6 of the backrest 2. The lower part of the partition 21 at this time is bent so as to fold backward relative to the upper part of the partition 21. Furthermore, the lower part of the partition 21 is bent so as to extend toward the lower end of the backrest 2 when the airbag 3 is deployed and inflated with the backrest 2 in the appropriate position for the vehicle to be in motion.

Next, the partition section 21 will be described in detail.
Fig. 5 shows the sheet-like partition 21 in an unfolded state. As can be seen from Fig. 5, the partition 21 has a symmetrical shape with respect to the center line L3. A hole 24 for connecting the upstream expansion section 22 and the downstream expansion section 23 shown in Fig. 4 is formed on the center line L3 of the partition 21. As shown in Fig. 5, the length of the partition 21 in a direction perpendicular to the center line L3 (the left-right direction in Fig. 5) is a constant value W1 at the upper part of the partition 21, and a value W2 larger than the value W1 at the lower part of the partition 21. This value W2 gradually increases toward the lower end of the partition 21 in Fig. 5.

The left edge of the partition 21 in FIG. 5 is joined to one of the folded pieces of fabric 13 in the airbag 3 (FIG. 3) as shown by dashed line L4 in FIG. 4. The right edge of the partition 21 in FIG. 5 is joined to the other folded piece of fabric 13. The joining point of the partition 21 to the fabric piece 13 (dashed line L4 in FIG. 4) extends in the vertical direction, and the lower part of the partition 21 is bent so as to fold toward the rear of the vehicle relative to the upper part.

The partition 21 is folded in two around the center line L3 in FIG. 5 inside the airbag 3 while being connected to the piece of fabric 13 as described above. In the event of a side collision of the vehicle, the inflation gas ejected from the ejection portion 20 of the inflator 4 first flows to the upstream inflation portion 22 of the airbag 3, and then flows to the downstream inflation portion 23 via the hole 24. This causes the folded airbag 3 to quickly deploy and inflate from the rear to the front of the vehicle.

When the backrest 2 of the seat 1 is in the appropriate position for when the vehicle is traveling and the airbag 3 is deployed and inflated as described above, the upper part of the partition 21 extends in the vertical direction. Note that the vertical direction here refers not only to the direction of a perpendicular line to a horizontal plane, but also to the direction of a straight line inclined at a specified angle to the perpendicular line. Furthermore, the specified angle here is assumed to be, for example, greater than 0° and less than 45°.

The thickness of the airbag 3 in the vehicle width direction when deployed and inflated is determined by the length of the partition 21 in the left-right direction in FIG. 4. The above-mentioned length (value W2) of the lower part of the partition 21 is greater than the above-mentioned length (value W1) of the upper part of the partition 21. Therefore, the thickness of the airbag 3 in the vehicle width direction is greater at the location corresponding to the lower part of the partition 21 than at the location corresponding to the upper part of the partition 21.

Next, the operation of the side airbag device of this embodiment will be described.
During a side collision of the vehicle, the inflation gas ejected from the inflator 4 into the airbag 3 first flows to the upstream inflation section 22 and then flows to the downstream inflation section 23 via the holes 24. Due to this flow of inflation gas, inside the deployed and inflated airbag 3, the upstream inflation section 22 becomes pressurized higher than the downstream inflation section 23. As shown by the two-dot chain line in Figure 1, when the airbag 3 is deployed and inflated, the upstream inflation section 22 is located substantially in correspondence with the seat back 2, and the downstream inflation section 23 is located so as to protrude forward from the upstream inflation section 22.

The partition 21, which divides the interior of the airbag 3 into an upstream inflation section 22 and a downstream inflation section 23, is bent so that its lower portion folds rearward relative to its upper portion. This causes the lower portion of the upstream inflation section 22 in the deployed and inflated airbag 3 to be positioned rearward of the waist of the occupant P1, i.e., corresponding to the backrest 2 of the seat 1 in which the occupant P1 is seated. Therefore, if the occupant P1 is sitting on the seat 1 in an incorrect posture, the lower portion of the upstream inflation section 22 in the deployed and inflated airbag 3 will not come into contact with the occupant P1.

According to the present embodiment described above in detail, the following effects can be obtained.
(1) It is possible to prevent the lower part of the upstream inflation section 22, which becomes highly pressurized, from hitting parts of the occupant P1 other than the waist when the occupant P1 is in an improper posture, and to prevent this from making it difficult for the airbag 3 to effectively protect the occupant P1 from a side collision of the vehicle.

(2) When the airbag 3 is deployed and inflated, the thickness in the vehicle width direction is thicker at the location corresponding to the lower part of the partition 21 than at the location corresponding to the upper part of the partition 21. As a result, the thickness in the vehicle width direction of the airbag 3 at the location that contacts the waist of the occupant P1 is greater. This improves the ability of the airbag 3 to absorb the impact on the waist of the occupant P1 during a side collision of the vehicle.

(3) When the airbag 3 deploys and inflates with the backrest 2 of the seat 1 in the appropriate position for the vehicle to be driven, the lower portion of the partition 21 extends toward the lower end of the backrest 2. This allows the lower portion of the upstream expansion section 22 when the airbag 3 deploys and inflates to be positioned in correspondence with the backrest 2 of the seat 1 on which the occupant P1 is seated.

The above embodiment can be modified, for example, as follows: The above embodiment and the following modified examples can be combined with each other to the extent that no technical contradiction occurs.
The lower part of the partition 21 does not necessarily have to extend toward the lower end of the backrest 2 when the airbag 3 is deployed and inflated with the backrest 2 of the seat 1 in the appropriate position for the vehicle to be traveling.

The width (value W2) of the lower portion of the partition 21 does not necessarily have to be greater than the width (width W1) of the lower portion.
Although the airbag 3 is stored in the backrest 2 of the seat 1 in the above embodiment, the airbag 3 may be stored in another location, such as the body side portion 11 .

REFERENCE SIGNS LIST 1 seat 2 backrest 3 airbag 4 inflator 5 retainer 6 frame 7 bolt 8 nut 9 control device 10 impact sensor 11 body side portion 13 piece of fabric 14 opening 15 mounting hole 20 ejection portion 21 partition portion 22 upstream inflation portion 23 downstream inflation portion 24 hole

Claims (2)

A side airbag device that supplies gas from an inflator to a folded and stored airbag, thereby deploying and inflating the airbag from the rear to the front of a vehicle between an area from the chest to the waist of an occupant seated in a vehicle seat and a body side of the vehicle, comprising:
The airbag includes a partition that divides an interior of the airbag into an upstream inflation portion and a downstream inflation portion,
the upstream inflation section is supplied with gas from the inflator,
the downstream inflation portion is supplied with the gas from the upstream inflation portion and is located forward of the upstream inflation portion when the airbag is deployed and inflated;
The partition is elongated vertically when the airbag is deployed and inflated, and the lower portion is bent so as to fold rearward relative to the upper portion ,
When the airbag is deployed and inflated, a length of the partition in a vehicle width direction is longer at a lower portion than at an upper portion of the partition,
In a side airbag device , in a lower portion of the partition, the length gradually increases toward the lower end. the airbag is stored in a folded state in the backrest of the seat, and is deployed and inflated forward from the backrest by the supply of gas from the inflator,
2. The side airbag device according to claim 1, wherein the partition is bent relative to the upper portion of the partition so that the lower portion of the partition extends toward the lower end of the backrest when the airbag is deployed and inflated with the backrest in an appropriate position for the vehicle being driven.