JP7513492B2 - Vehicle side airbag - Google Patents

Description

The present invention relates to a side airbag for a vehicle.

Patent Document 1 discloses a side airbag that inflates and deploys to the side of an occupant during a side collision. The side airbag disclosed in Patent Document 1 is comprised of a head protection inflation section (upper chamber) that restrains the occupant's head, a lumbar protection inflation section (lower chamber) that restrains the occupant's lumbar region, and an intermediate inflation section that connects the head protection inflation section and the lumbar protection inflation section.

JP 2011-105107 A

However, in the side airbag described in Patent Document 1, the upper chamber is inflated and deployed at a position spaced apart in the seat width direction from the occupant's head, making it difficult to ensure an initial restraining force in the event of a side collision.

The present invention takes the above into consideration and aims to provide a vehicle side airbag that can ensure initial restraint force during a side collision.

The vehicle side airbag according to claim 1 is stored inside a vehicle seat, and when a side collision is predicted or detected, is supplied with gas from an inflator to be inflated and deployed on the outer side of an occupant in the vehicle width direction, and is configured as an integrated bag body including an upper chamber that covers the side of the occupant's head in an inflated and deployed state , a lower chamber that covers the side of the occupant below the occupant's head, and an intermediate portion that extends in the seat width direction so as to connect the upper chamber and the lower chamber when viewed from the front of the seat, the upper chamber is stored in a folded state in the front-rear direction of the seat at the upper end of the seat back, and is inflated and deployed toward the space between an upper rear surface of a shoulder belt that restrains the upper body of the occupant to the seat back and a headrest, and the intermediate portion is folded in the seat width direction with the upper chamber stored in a folded state in the front-rear direction of the seat .

The vehicle side airbag according to claim 1 comprises an upper chamber and a lower chamber, which receive gas from an inflator when a side collision is predicted or detected, and are inflated and deployed on the sides of the occupant. The upper chamber is configured to cover the sides of the occupant's head when inflated and deployed, and the lower chamber is configured to cover the sides below the occupant's head when inflated and deployed. This makes it possible to restrain the sides of the occupant over a wide area in the event of a side collision of the vehicle.

The upper chamber is stored in a folded state in the front-rear direction of the seat at the top end of the seat back. The upper chamber is inflated and deployed toward the space between the upper rear surface of the shoulder belt and the headrest. As a result, the upper chamber is sandwiched between the occupant's head and the shoulder belt in the early stages of a collision, making it possible to restrain the occupant's head early.

As explained above, the vehicle side airbag according to the present invention can ensure an initial restraining force during a side collision.

1 is a front view showing a vehicle seat to which a vehicle side airbag according to an embodiment is applied, showing a state in which the side airbag is inflated and deployed; 1 is a side view showing a vehicle seat to which a vehicle side airbag according to an embodiment is applied, showing a state in which the side airbag is inflated and deployed; FIG. 2 is a diagram illustrating a side airbag according to the embodiment in a pre-folded state. 4A and 4B are diagrams showing the state in which the side airbag is folded up from the state shown in FIG. 3, in which (A) shows the state before the upper chamber is folded up, and (B) shows the state after the upper chamber is folded up. 4 is a graph showing the relationship between the acceleration acting on the head and the stroke during a side collision of the vehicle for the side airbag of the present embodiment and the side airbag of the comparative example.

The vehicle side airbag 10 according to the embodiment will be described below with reference to the drawings. Note that the arrows FR, UP, and RH in each drawing indicate the front, upper, and right sides of the vehicle seat 14 on which the vehicle side airbag 10 is mounted, respectively. When describing the directions of front/rear, left/right, top/bottom, they refer to front/rear in the front/rear direction of the seat, left/right in the width direction of the seat, and top/bottom in the top/bottom direction of the seat, unless otherwise specified.

(Vehicle seat 14)
As shown in Fig. 1, a vehicle seat 14 equipped with a vehicle side airbag 10 of this embodiment (hereinafter simply referred to as "side airbag 10") includes a seat cushion 16, a seat back 18, and a headrest 20. Also, as shown in Fig. 2, a side airbag device 12 includes the side airbag 10 of this embodiment and an inflator 42. Note that the vehicle seat 14 shown in Figs. 1 and 2 is, as an example, disposed in the driver's seat on the left side of the vehicle, so that the front of the seat coincides with the front of the vehicle. Also, the left and right sides of the seat width direction coincide with the left and right sides of the vehicle width direction.

In the vehicle seat 14 shown in Figures 1 and 2, a crash test dummy P is seated in place of an actual occupant. This dummy P is, for example, the AM50 (50th percentile of adult American males) of the WorldSID (World Side Impact Dummy). For ease of explanation, dummy P will be referred to as "occupant P" below.

The seat cushion 16 extends in the front-rear and width directions of the seat and is configured to be able to support the buttocks and thighs of the occupant P. The seat back 18 is rotatably connected to the rear end of the seat cushion 16 and extends in the up-down direction of the seat and is configured to be able to support the back of the occupant P. The headrest 20 is provided at the upper end of the seat back 18 and is configured to be able to support the head H of the occupant P.

(Seatbelt device 24)
1, an occupant P is restrained in a vehicle seat 14 by a seat belt device 24. The seat belt device 24 includes a webbing 26, a tongue plate 30, a buckle 32, and a retractor (not shown).

The webbing 26 is formed in a long belt shape and includes a shoulder belt 26A that restrains the upper body of the occupant P to the seat back 18 when worn, and a lap belt 26B that restrains the occupant's waist L. The shoulder belt 26A extends diagonally from the left shoulder S of the occupant P to the right waist L. The lower end of the shoulder belt 26A is passed through the tongue plate 30.

The tongue plate 30 is threaded through the webbing 26 and is configured to be detachable from a buckle 32 provided on the left side of the seat. When the tongue plate 30 is attached to the buckle 32, the occupant P is restrained by the webbing 26.

The webbing 26 extends from the tongue plate 30 to the left side of the seat, and the portion extending in the seat width direction constitutes the lap belt 26B. Therefore, the right end of the lap belt 26B is connected to the lower end of the shoulder belt 26A. The left end of the lap belt 26B is fixed to a belt anchor 34 provided on the floor panel 40. The left end of the lap belt 26B may also be fixed to the seat cushion 16.

The upper end of the shoulder belt 26A is wound around a shoulder anchor (not shown) provided on the vehicle body. The end of the webbing 26 is wound up on a retractor (not shown). If the webbing 26 is suddenly pulled out, an emergency locking mechanism of the retractor is activated to lock the webbing 26 from being pulled out. The retractor is also provided with a pretensioner mechanism that is activated when a collision is detected to forcibly wind up the webbing 26.

(Side airbag device 12)
As shown in FIG. 2 , the side airbag device 12 includes an inflator 42 and the side airbag 10 .

The inflator 42 is a cylindrical gas generating device formed in a substantially cylindrical shape, with its axial direction aligned with a side frame (not shown) that constitutes the framework of the seat back 18. The lower end 42A of the inflator 42 is connected to the connection portion 10A of the side airbag 10. The lower end 42A of the inflator 42 is provided with a gas ejection portion.

The inflator 42 is electrically connected to a control unit such as an ECU (Electronic Control Unit). When a side collision of the vehicle is detected or predicted based on signals from sensors such as a side collision detection sensor that detects a side collision of the vehicle and a side collision prediction sensor that predicts a side collision, the inflator 42 is activated by a signal from the ECU. When the inflator 42 is activated, gas is generated from the gas ejection portion of the inflator 42 and the gas is supplied to the side airbag 10. Note that, for example, a pressure sensor and an acceleration sensor arranged on the side of the vehicle body can be used as the side collision detection sensor. Also, for example, a pre-crash sensor equipped with a millimeter wave radar, Lidar (Laser Imaging Detection and Ranging), and a stereo camera can be used as the side collision prediction sensor.

The side airbag 10 is stored inside the seat back 18 (vehicle seat 14) and is inflated when gas generated by the inflator 42 is supplied to it. The expansion pressure of the side airbag 10 breaks the skin of the seat back 18, causing the side airbag 10 to inflate and deploy laterally to the outside of the seat width direction (outside of the vehicle width direction) relative to the occupant P.

Here, the side airbag 10 has a head chamber 10B as an upper chamber that covers the sides of the head H of the occupant P when inflated and deployed, and a lumbar chamber 10C as a lower chamber that covers the sides of the occupant P below the head H. The side airbag 10 is configured as an integrated bag body in which the lumbar chamber 10C and the head chamber 10B are connected to each other.

The head chamber 10B in the inflated and deployed state is disposed from the headrest 20 to the upper end of the seat back 18, and is formed in a substantially rectangular shape so as to cover the head H of the occupant P when viewed from the seat width direction. The lumbar chamber 10C in the inflated and deployed state is disposed from the upper to lower end of the seat back 18 when viewed from the seat width direction, and is formed in a substantially elliptical shape with the vertical center part bulging out toward the front side of the seat. Furthermore, the intermediate part 10D between the head chamber 10B and the lumbar chamber 10C is located at the upper end of the seat back 18, and is formed so that its length in the vehicle front-rear direction is short when viewed from the seat width direction. Also, as shown in FIG. 1, the intermediate part 10D extends in the seat width direction so as to connect the head chamber 10B and the lumbar chamber 10C when viewed from the front of the seat.

As shown in FIG. 1, the head chamber 10B is configured to inflate and deploy toward the space between the upper rear surface of the shoulder belt 26A and the headrest 20. In this embodiment, as an example, the head chamber 10B is stored in the upper end of the seat back 18 along the seat width direction. When gas is supplied to the head chamber 10B, the expansion pressure of the head chamber 10B breaks the skin at the upper end of the seat back 18, and the head chamber 10B is configured to inflate and deploy toward the space between the shoulder belt 26A and the headrest 20.

(Procedure for folding the side airbag 10)
An example of a procedure for folding the side airbag 10 according to this embodiment will be described with reference to Figs. 3 and 4 .

As shown in FIG. 3, the side airbag 10 is formed into a bag-like shape by overlapping two pieces of base fabric formed into approximately the same shape and sewing them together at a sewing section 50. In the explanation of FIG. 3 and FIG. 4, when up, down, front, back, left and right are used, they refer to up and down in the seat vertical direction, front and back in the seat longitudinal direction, and left and right in the seat width direction when the side airbag 10 is inflated and deployed, unless otherwise specified.

In this embodiment, the side airbag 10 is folded in an accordion-like manner from the state shown in FIG. 3, and the middle portion 10D is further folded in the seat width direction, resulting in the state shown in FIG. 4(A).

Next, from the state shown in FIG. 4(A), the head chamber 10B is folded in the front-to-rear direction of the seat to obtain the state shown in FIG. 4(B). Specifically, from the state shown in FIG. 4(A), the head chamber 10B is folded forward and downward, and then folded forward and upward again. In this way, the head chamber 10B is folded up and down multiple times toward the front side of the seat to obtain the state shown in FIG. 4(B). Note that for ease of explanation, FIG. 4(B) shows a state where the head chamber is folded up and down four times, but it may be folded further.

As shown in FIG. 4(B), the head chamber 10B is tied down by a tether (not shown). This maintains the shape of the head chamber 10B. The tether that ties down the head chamber 10B is set to a strength that will break due to the inflation pressure of the head chamber 10B. After the side airbag 10 folded up in this way is stored in the seat back 18, a seat pad made of urethane foam (not shown) is placed on the seat back frame, and then a seat cover is placed on top of that. A breakable portion is set in the seat cover, and this breakable portion is formed by sewing the covers together with a strength that will break due to the inflation pressure of the side airbag 10.

(Action)
Next, the operation of this embodiment will be described.

As shown in FIG. 2, the side airbag 10 according to this embodiment receives gas from the inflator 42 when a side collision is predicted or detected, and is inflated and deployed to the side of the occupant P. Here, the side airbag 10 has a head chamber 10B that covers the side of the head H of the occupant P when inflated and deployed, and a waist chamber 10C that covers the side of the waist L of the occupant P. This allows the side airbag 10 to provide wide-area protection for the side of the occupant P in the event of a side collision.

In this embodiment, the head chamber 10B is stored in a folded state in the front-rear direction of the seat at the top end of the seat back 18 (see FIG. 4B), and is inflated and deployed toward the space between the upper rear surface of the shoulder belt 26A and the headrest 20. As a result, the head chamber 10B is sandwiched between the head H of the occupant P and the shoulder belt 26A in the early stages of a collision, allowing the head H of the occupant P to be restrained early.

The above effects will be described with reference to FIG. 5. FIG. 5 shows a graph illustrating the relationship between head G and head stroke during a side collision of the vehicle. Here, head G refers to the acceleration acting on the head H of the occupant P, and head stroke refers to the amount of movement of the head H of the occupant P in the seat width direction. Furthermore, curve C1 shown by a solid line represents data during a side collision of a vehicle equipped with the side airbag 10 according to this embodiment, and curve C2 shown by a dashed line represents data during a side collision of a vehicle equipped with a side airbag according to a comparative example.

First, the comparative side airbag will be described. In the comparative side airbag, the head chamber (upper chamber) is inflated and deployed between the upper part of the shoulder belt 26A and the side of the vehicle interior. That is, the comparative head chamber is not inflated and deployed in the space between the upper rear surface of the shoulder belt 26A and the headrest 20, but is inflated and deployed at a position where the head chamber and the lumbar chamber are substantially linear in the vertical direction when viewed from the front side of the seat. Therefore, in the comparative side airbag, a gap is provided in the seat width direction between the head chamber and the head H of the occupant P.

Curve C2 in Figure 5 shows that head G rises sharply when the head stroke reaches a certain value. This is because the head H of the occupant P moves inertially toward the side of the vehicle compartment during a side collision, and is then restrained by the head chamber.

On the other hand, looking at curve C1, head G is detected at a position where the head stroke is smaller than in the comparative example. This is because in the side airbag 10 of this embodiment, the head chamber 10B is inflated and deployed into the space between the upper rear surface of the shoulder belt 26A and the headrest 20. Also, in this embodiment, the head chamber 10B can restrain the head H when the amount of movement is small, so it can be seen that the head G is smaller than in the comparative example. In this way, the side airbag 10 of this embodiment can ensure initial restraint during a side collision compared to the side airbag of the comparative example.

In addition, in this embodiment, the head chamber 10B is sandwiched between the head H of the occupant P and the shoulder belt 26A, and is able to obtain a reaction force from the shoulder belt 26A, making it possible to restrain the head H of the occupant P with a small volume. As a result, the volume of the head chamber 10B can be reduced, the side airbag 10 can be made smaller, and the time required for the head chamber 10B to inflate and deploy can be shortened.

Furthermore, by making the side airbag 10 itself smaller, the manufacturing process and material costs can be reduced, resulting in lower costs.

Although the side airbag 10 according to the embodiment has been described above, it is of course possible to implement it in various ways without departing from the scope of the present invention. For example, in the above embodiment, as shown in FIG. 4(B), the head chamber 10B is folded up and down toward the front to form a bellows shape, but this is not limited to this, and other folding methods may be adopted. For example, the head chamber 10B may be folded left and right toward the front to form a bellows shape. This folding method reduces the vertical dimension compared to the folding method shown in FIG. 4(B).

Alternatively, the head chamber 10B may be folded into an accordion shape, while the waist chamber 10C may be folded into a roll shape.

In the above embodiment, as shown in FIG. 2, the side airbag 10 is configured to restrain the occupant with the head chamber 10B and the lumbar chamber 10C, but this is not limited to the above. For example, the side airbag 10 may be configured with a thoracic chamber that covers the thorax B of the occupant P from the side. In this case, the lower chamber is formed to include the lumbar chamber 10C and the thoracic chamber.

Furthermore, the waist chamber 10C is not limited to the shape shown in FIG. 2, so long as it is shaped to cover the waist L of the occupant P from the side. Similarly, the head chamber 10B is not limited to the shape shown in FIG. 2, so long as it is shaped to cover the head H of the occupant P from the side.

10 Vehicle side airbag 10B Head chamber (upper chamber)
10C Lumbar chamber (lower chamber)
14 Vehicle seat 18 Seat back 20 Headrest 26A Shoulder belt 42 Inflator H Head region L Waist region P Occupant

Claims (1)

The inflator is stored inside a vehicle seat, and when a side collision is predicted or detected, gas is supplied from an inflator to inflate and deploy on the outer side of the occupant in the vehicle width direction, and the inflator is configured as an integrated bag body including an upper chamber that covers the side of the occupant's head when inflated and deployed , a lower chamber that covers the side of the occupant below the occupant's head, and an intermediate portion that extends in the seat width direction so as to connect the upper chamber and the lower chamber when viewed from the front of the seat ,
the upper chamber is stored in an upper end of a seat back in a folded state in the front-rear direction of the seat, and is inflated and deployed toward a space between an upper rear surface of a shoulder belt that restrains an upper body of an occupant to the seat back and a headrest ,
The vehicle side airbag is stored in a state where the entire side airbag is folded in a bellows shape, the intermediate portion is folded in the seat width direction, and the upper chamber is folded in the seat front-rear direction.