JP7604312B2 - Airbag device - Google Patents

Description

This disclosure relates to an airbag device.

Conventionally, there are airbag devices that are installed in vehicles such as automobiles to protect occupants from impacts when the vehicle collides. Patent Document 1 discloses technology relating to an airbag device that is installed in the steering wheel of a vehicle and has a recess in part of the airbag body that faces the floor of the vehicle. With this airbag device, when the airbag body deploys, the abdomen of the occupant is positioned in the recess in the airbag body, thereby reducing the load on the abdomen in particular.

Special Publication No. 2013-529577

In the airbag device described in Patent Document 1, the deployed shape of the airbag body is constant, so that under certain conditions, the load on the occupant's chest can be reduced. However, under different conditions, for example, when the occupant's condition or physique changes, there is a need to deal appropriately with cases where load reduction is more necessary or where load reduction is not necessary.

Therefore, the present disclosure aims to provide an airbag device that provides appropriate protection for an occupant depending on the occupant's situation and physique.

The airbag device disclosed herein includes an airbag body that inflates from a folded state with the inflow of gas to protect the vehicle occupant, and the airbag body has a shape-variable region on the lower side facing the seat of the occupant that inflates less than the main inflation section on the upper side and changes its deployed shape depending on the condition of the occupant.

This disclosure makes it possible to provide an airbag device that provides appropriate protection for an occupant depending on the occupant's condition and physique.

FIG. 2 is a passenger-side perspective view of an airbag main body according to an embodiment. FIG. 2 is a perspective view of an airbag body portion according to an embodiment, taken from the vehicle body side. FIG. 2 is a perspective view showing a shape of an airbag main body before installation in one embodiment. 1 is a cross-sectional view of an airbag device according to an embodiment. 5A to 5C are diagrams illustrating the operation of the airbag device according to the embodiment. 13 is a graph showing the results of an analysis of the load on the chest of a dummy. 13 is a graph showing the results of an analysis of the load on the chest of a dummy.

Below, exemplary embodiments will be described with reference to the drawings. Here, elements having substantially the same functions and configurations are denoted with the same reference numerals to avoid repetitive explanations, and elements not directly related to this disclosure are not illustrated.

Figure 1 is an occupant-side perspective view of an airbag body 10 provided in an airbag device 1 (see Figure 4) according to one embodiment. Figure 2 is a vehicle-side perspective view of the airbag body 10. In the following figures, the X, Y and Z directions are illustrated for reference. The X direction is generally along the straight-ahead direction of a vehicle such as an automobile in which the airbag device 1 is employed. The Y direction is perpendicular to the XZ plane and generally along the vehicle width direction. The Z direction is generally perpendicular to the XY plane, i.e., the floor surface on which the occupant's seat 100 (see Figure 5) is placed.

The airbag body 10 is normally stored in a folded state, for example, in the steering wheel of an automobile. When the vehicle collides, the airbag body 10 inflates and deploys due to the inflow of gas, protecting the occupant from the impact of the collision. Note that Figs. 1 and 2 show the state of the airbag body 10 when deployed. In the following, in this embodiment, the airbag device 1 is described as being for the driver's seat, installed on the steering wheel 101 (see Fig. 5(b)) of an automobile. In other words, the object to be protected is the occupant sitting in the driver's seat. In this case, Fig. 1 corresponds to a view from the occupant sitting in the driver's seat. Meanwhile, Fig. 2 corresponds to a view from the steering wheel 101 side.

Figure 3 is a perspective view showing the shape of the airbag body 10 before it is installed. For reference, Figure 3 shows the deployed shape of the airbag body 10 before it is installed, in which gas is injected into the internal space and it is inflated. Figure 4 corresponds to the IV-IV section in Figure 1, and is a cross-sectional view of the airbag device 1 cut along the XZ plane passing through the center position in the Y direction.

The airbag device 1 comprises an airbag body 10, an inflator 11, a retainer 12, and a bag plate 13.

The airbag body 10 is a bag formed of one or more base fabrics. In this embodiment, the airbag body 10 is formed into a bag shape as a whole by combining and joining two base fabrics, namely, a first panel 20 which is the base fabric on the occupant side and a second panel 21 which is the base fabric on the vehicle body side, by sewing, bonding, welding, or the like. The second panel 21 has two types of through holes: an attachment port 22 for attaching the inflator 11, and an exhaust port 23 for exhausting gas from the internal space of the airbag body 10 to the outside after inflation. A through hole such as the exhaust port 23 is sometimes called a vent hole.

First, referring to the shape of the airbag body 10 before installation shown in FIG. 3, the airbag body 10 includes a main inflatable portion 10a and a pair of rod-shaped inflatable portions, a first rod-shaped inflatable portion 10b and a second rod-shaped inflatable portion 10c.

The main inflation section 10a is an inflation region located on the upper side of the airbag body 10 in the Z direction. When the airbag body 10 is deployed, the main inflation section 10a is expected to restrain the head, shoulders, or part of the chest of the occupant.

The first rod-shaped inflation section 10b and the second rod-shaped inflation section 10c are inflation regions located on the lower side of the airbag body 10 in the Z direction. The first rod-shaped inflation section 10b and the second rod-shaped inflation section 10c each have an internal space continuous with the main inflation section 10a, and extend downward in the Z direction from the main inflation section 10a when the airbag body 10 is in a deployed shape before installation. Here, downward in the Z direction refers to the direction toward the installation side of the occupant's seat 100. The first rod-shaped inflation section 10b and the second rod-shaped inflation section 10c face each other while being spaced apart from each other in the Y direction.

The airbag body 10 also has a connecting member 14 and an insertion retaining portion 10e.

The connecting material 14 is a strap (string-like member) having one end connected to the tip of the first rod-shaped inflatable portion 10b and the other end connected to the tip of the second rod-shaped inflatable portion 10c. In other words, the connecting material 14 connects the tip of the first rod-shaped inflatable portion 10b and the tip of the second rod-shaped inflatable portion 10c. In this embodiment, the connecting material 14 is a flat strap. When the airbag body 10 is in the deployed shape before installation, the connecting material 14 has slack.

The insertion retaining portion 10e is a tab (a plate-shaped portion) provided on a part of the main expansion portion facing the space S between the first rod-shaped expansion portion 10b and the second rod-shaped expansion portion 10c. As shown in FIG. 3, the insertion retaining portion 10e may be provided as a part of the remaining margin remaining on the outer periphery when the first panel 20 and the second panel 21 are joined. The insertion retaining portion 10e also has an insertion hole 10f through which the connecting material 14 is inserted. The insertion hole 10f is a hole that penetrates along the joining direction of the first panel 20 and the second panel 21. The insertion hole 10f has a shape that allows at least a part of the connecting material 14 in the folded state to be inserted therethrough. In this embodiment, the insertion hole 10f is formed in a slit shape having a length greater than the width of the connecting material 14.

The inflator 11 is a device that introduces gas (expansion gas) into the airbag body 10. For example, the inflator 11 includes an igniter, a gas generating agent, and the like. In this case, the igniter burns the gas generating agent based on an electrical signal emitted by an electronic control unit (not shown) when it detects or predicts a vehicle collision, etc., and gas is rapidly introduced into the airbag body 10.

The retainer 12 is a frame for attaching the airbag body 10 and the inflator 11 to an installation portion on the vehicle side.

The bag plate 13 is a member that supports the retainer 12. The bag plate 13 may be a part of the installation portion on the vehicle side, for example, the steering wheel 101 in this embodiment. The airbag device 1 may also be installed on the steering wheel 101 with the airbag body 10, the inflator 11, and the retainer 12 housed in a case (not shown). In this case, the bag plate 13 may be a part of the case.

The airbag device 1 further includes a connecting member holding portion 15 that holds the connecting member 14 inserted through the insertion hole 10f provided in the insertion holding portion 10e. As shown in FIG. 2, the connecting member 14 is inserted through the insertion hole 10f in the direction from the first panel 20 side toward the second panel 21 side. Since one end of the connecting member 14 is connected to the tip of the first rod-shaped inflatable portion 10b and the other end is connected to the tip of the second rod-shaped inflatable portion 10c, the connecting member 14 inserted through the insertion hole 10f becomes annular as a whole. Therefore, the connecting member holding portion 15 may be a rod-shaped or hook-shaped protrusion that is installed on the bag plate 13 and hooks and holds a part of the annular connecting member 14, as shown in FIG. 4.

Next, the deployed shape of the airbag body 10 when the airbag device 1 is activated will be described with reference to Figures 1, 2, and 4.

When gas is introduced from the inflator 11 into the inside of the airbag body 10, the main inflation section 10a inflates. In addition, in accordance with the inflation of the main inflation section 10a, the first rod-shaped inflation section 10b and the second rod-shaped inflation section 10c, to which gas is introduced through each communication port 10g in the internal space of the airbag body 10, also inflate. The connecting material 14 inserted through the insertion hole 10f is held by the connecting material holding section 15 provided on the vehicle body side before the airbag body 10 is deployed. Therefore, when gas is introduced and the airbag body 10 begins to inflate, the connecting material 14 inserted through the insertion hole 10f is pulled in the insertion direction. The insertion hole 10f is provided in a part of the main inflation section 10a facing the space S between the first rod-shaped inflation section 10b and the second rod-shaped inflation section 10c facing each other. Therefore, the tips of the first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c are drawn toward the insertion hole 10f, and the first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c inflate into a shape that is folded into the space S, as shown in Figures 1 and 2. As a result, the airbag body 10, which has a shape including a recess formed by the first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c before installation, unfolds into a circular shape overall.

As a result of this expansion, a shape-variable region 30 is formed in the airbag body 10 at the time of deployment in a portion facing the occupant, as shown in Figs. 1 and 4. The shape-variable region 30 includes the first rod-shaped expansion portion 10b and the second rod-shaped expansion portion 10c that are expanded to a shape folded into the space S, and the lower portion of the main expansion portion 10a that is continuous with the first rod-shaped expansion portion 10b and the second rod-shaped expansion portion 10c. The body part of the occupant that is restrained by the shape-variable region 30 at the time of deployment of the airbag body 10 is assumed to be a part of the chest or the abdomen. In addition, the expansion amount in the shape-variable region 30 is smaller than the expansion amount in the main expansion portion 10a located above the part of the shape-variable region 30 that is the region where the first rod-shaped expansion portion 10b and the second rod-shaped expansion portion 10c are folded into the space S.

Next, the operation of the airbag device 1 will be explained.

Figure 5 is a diagram for explaining an example of the operation of the airbag device 1 using a dummy D. Figure 5 illustrates the restraining state of the dummy D when the airbag main body 10 is deployed, assuming a frontal collision of the vehicle. Figure 5(a) illustrates the restraining state of the dummy D when viewed from the front of the vehicle. Figure 5(b) illustrates the restraining state of the dummy D when viewed from the side of the vehicle. At this time, the dummy D is lifted off the seat 100 as the vehicle crashes frontally, and is pressed against the airbag main body 10 deployed from the steering wheel 101.

When the airbag body 10 is deployed, the shape-variable region 30 is formed in the airbag body 10 as described above. The amount of expansion of the shape-variable region 30 is smaller than that of the main expansion section 10a located above it. Therefore, when the airbag body 10 restrains the dummy D, it mainly receives the shoulders of the dummy D. In other words, the airbag body 10 is less likely to compress the chest (or abdomen) D1 of the dummy D.

6 and 7 are graphs showing the results of an analysis of the load applied to the chest D1 of the dummy D due to restraint by the airbag main body 10. Here, the dummy D used for the analysis is a THOR (Test Device for Human Occupant Restraint) dummy. As shown in FIG. 5, the dummy D includes displacement gauges installed at four positions, top, bottom, left, and right, to measure the amount of displacement of the chest D1 due to restraint (hereinafter referred to as "chest displacement"). Of these, the first displacement gauge G _UL has a measurement point set at the upper left position of the chest D1. The second displacement gauge G _UR has a measurement point set at the upper right position of the chest D1. The third displacement gauge G _LL has a measurement point set at the lower left position of the chest D1. The fourth displacement gauge G _LR has a measurement point set at the lower right position of the chest D1.

The graph shown in Fig. 6(a) shows the change in chest displacement [mm] with respect to time [ms] after the collision obtained by the first displacement meter G _UL . The graph shown in Fig. 6(b) shows the change in chest displacement [mm] with respect to time [ms] after the collision obtained by the second displacement meter G _UR . The graph shown in Fig. 7(a) shows the change in chest displacement [mm] with respect to time [ms] after the collision obtained by the third displacement meter G _LL . The graph shown in Fig. 7(b) shows the change in chest displacement [mm] with respect to time [ms] after the collision obtained by the fourth displacement meter G _LR .

In each graph, the value when the airbag device 1 according to this embodiment is used is indicated as "Airbag A". As a comparative example, the value when a conventional airbag device having a simple circular airbag body is used is indicated as "Airbag B". As a further comparative example, the value when no airbag device is used is indicated as "No airbag". Note that dummy D is wearing a seat belt in all cases.

Looking at these analysis results, with conventional airbag B, chest displacement tends to be large when restrained by the airbag body. In contrast, with airbag A of the present embodiment, as shown by the open arrows in each graph, it can be seen that the peak value of chest displacement is lower than in the case of airbag B. In other words, by employing the airbag device 1 of the present embodiment, there is a high possibility that the load on the occupant's chest can be reduced more than in the case of employing a conventional general airbag device.

In addition, in this embodiment, the shape-variable region 30 is formed by the first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c that are inflated to a shape that is folded into the space S. The first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c are inflatable portions that are independent of each other while using the main inflatable portion 10a as a reference. Therefore, when the airbag body portion 10 is deployed, the individual shapes of the first rod-shaped inflatable portion 10b and the second rod-shaped inflatable portion 10c are not always constant relative to the main inflatable portion 10a. For example, depending on the condition of the occupant, such as the physique, the first rod-shaped inflatable portion 10b may be pushed forward in the X direction more than the second rod-shaped inflatable portion 10c, or the first rod-shaped inflatable portion 10b may be folded into the space S by a larger amount than the second rod-shaped inflatable portion 10c. In other words, the shape-variable region 30 changes its deployed shape depending on the condition of the occupant. Here, the condition of the occupant includes the condition of the occupant or the physique of the occupant. The occupant's condition includes the occupant's posture, which changes depending on the collision angle of the car and the magnitude of the impact. The occupant's physical build takes into account not only body size, but also age and gender differences.

Next, the effects of the airbag device 1 will be explained.

The airbag device 1 according to this embodiment includes an airbag body 10 that inflates from a folded state with the inflow of gas to protect the vehicle occupant. The airbag body 10 has a shape-variable region 30 on the lower side facing the seat 100 of the occupant, which has a smaller amount of inflation than the upper main inflation section 10a, and whose deployed shape changes depending on the state of the occupant.

According to this airbag device 1, the airbag body 10 has a shape-variable region 30 that expands less than the main expansion section 10a, so the load on the occupant to be protected, particularly on the chest, can be reduced.

In addition, with this airbag device 1, the shape-variable region 30 changes its deployed shape depending on the state of the occupant, so the load on the occupant's chest can be reduced according to the occupant's condition, physique, etc.

In this way, according to this embodiment, it is possible to provide an airbag device 1 that appropriately protects the occupant depending on the situation and physique of the occupant.

In addition, in the airbag device 1, the shape-variable region 30 may include a first rod-shaped inflation portion 10b and a second rod-shaped inflation portion 10c, which are a pair of rod-shaped inflation portions whose internal space is continuous with the main inflation portion 10a and which extend from the main inflation portion 10a toward the installation side of the seat 100. When the airbag body portion 10 is deployed, the pair of rod-shaped inflation portions may be inflated into a shape that folds into the space S between the opposing portions.

According to this airbag device 1, the shape-variable region 30 can be easily provided in the airbag body 10. Furthermore, when the shape-variable region 30 is formed by such a pair of rod-shaped inflatable parts, the volume of the airbag body 10 does not exceed the volume of an airbag body used in a conventional airbag device installed in a similar installation target. Therefore, the inflator 11 used in the airbag device 1 may be equivalent to an inflator used in a conventional airbag device, which has the advantage that there is no need to use a larger inflator.

In the airbag device 1, the airbag body 10 may have a connecting member 14 having one end connected to the tip of the first rod-shaped inflatable portion 10b, which is one of the rod-shaped inflatable portions, and the other end connected to the tip of the second rod-shaped inflatable portion 10c, which is the other rod-shaped inflatable portion. The airbag body 10 may also have an insertion retaining portion 10e having an insertion hole 10f through which the connecting member 14 is inserted, which is provided in a part of the main inflatable portion 10a facing the space S between the pair of opposing rod-shaped inflatable portions. In this case, when the airbag body 10 is deployed, the connecting member 14 inserted through the insertion hole 10f may be pulled in the insertion direction, so that the pair of rod-shaped inflatable portions are folded into the space S between the opposing portions.

With this airbag device 1, the shape-variable region 30 is easily formed in the airbag body 10 as a result of the inflation action caused by the introduction of gas, so that the shape-variable region 30 can be stably formed.

As a reference example, in an airbag device in which a tether (tether) provided inside pulls part of the base material inward to form a recess (depression) in the airbag body, the shape of the inflatable portion located above the recess is likely to change before and after the recess is formed. In contrast, in the airbag device 1 according to this embodiment, the shape of the main inflatable portion 10a is stable and is unlikely to change between when the pair of rod-shaped inflatable portions are not folded and when they are folded to form the shape-variable region 30, as illustrated in FIG. 3. In other words, according to the airbag device 1, even if the shape-variable region 30 is formed in the airbag body 10, the function of the main inflatable portion 10a is unlikely to deteriorate.

The airbag device 1 according to this embodiment is not limited to being installed on the steering wheel 101, but may also be used, for example, for a passenger seat mounted on the instrument panel of a vehicle.

In addition, the embodiments can be modified or varied based on the above disclosure. Furthermore, all components of the above embodiments and all features described in the claims may be individually extracted and combined, as long as they are not mutually inconsistent.

REFERENCE SIGNS LIST 1 Airbag device 10 Airbag body 10a Main inflatable portion 10b First rod-shaped inflatable portion 10c Second rod-shaped inflatable portion 10f Insertion hole 10e Insertion and holding portion 14 Connecting member 30 Shape-variable region S Space

Claims (2)

an airbag body that inflates from a folded state due to an inflow of gas to protect a vehicle occupant;
the airbag body has a shape-variable region on a lower side facing the seat of the occupant, the shape-variable region having a smaller inflation amount than the upper main inflation portion, and the deployed shape of the shape-variable region changes depending on the state of the occupant,
the shape-variable region includes a pair of rod-shaped inflatable portions whose internal space is continuous with the main inflatable portion and which extend from the main inflatable portion toward the installation side of the seat,
The pair of rod-shaped inflatable portions inflate into a shape that is folded into the space between the opposing portions when the airbag main body is deployed . The airbag body portion is
a connecting member having one end connected to a tip of one of the rod-shaped expansion portions and the other end connected to a tip of the other rod-shaped expansion portion;
an insertion and holding portion provided in a part of the main expansion portion facing the space between the pair of rod-shaped expansion portions facing each other, the insertion and holding portion having an insertion hole through which the connecting material is inserted;
2. The airbag device according to claim 1, wherein when the airbag main body is deployed, the pair of rod -shaped inflation portions are folded into the space between the opposing portions by pulling the connecting material inserted through the insertion hole in the insertion direction.

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