JP7574516B2 - Airbag and airbag device - Google Patents

Description

This disclosure relates to airbags and airbag devices.

Conventionally, a method has been proposed in which an airbag is deployed from the headrest or seatback of a vehicle seat to protect the head of an occupant in all directions (for example, Patent Document 1).

JP 2017-030373 A

Conventional airbags that protect the occupant's head in all directions are configured to deploy the airbag from the headrest or seat back toward the front of the vehicle, so in order to position the airbag in front of the occupant, it is desirable to have a large clearance (gap) between the airbag and the occupant. On the other hand, when it comes to restraining the occupant, it is desirable to have a small clearance between the airbag and the occupant after deployment. Therefore, the interposition and restraint of the airbag are contradictory, and it is desirable to achieve both.

The objective of this disclosure is to provide an airbag and airbag device that can be smoothly deployed in front of the occupant and that can improve restraint performance after deployment.

An airbag according to one aspect of an embodiment of the present invention comprises a rear inflation section that deploys on the back side of a seat, a pair of side inflation sections that extend forward from both sides of the rear inflation section in the seat width direction and are connected to each other in front of the seat, a front portion of the airbag that is positioned in front of an occupant seated in the seat after the rear inflation section and the side inflation sections deploy , and a sub-bag that inflates to reduce clearance with the occupant .

Similarly, an airbag device according to one aspect of an embodiment of the present invention includes an inflator and the above-mentioned airbag that is deployed by gas supplied from the inflator.

This disclosure makes it possible to provide an airbag and airbag device that can be smoothly deployed in front of the occupant and that can improve restraint performance after deployment.

FIG. 1 is a perspective view of an airbag device according to a first embodiment when the airbag is deployed; FIG. 2 is a side view of the airbag device shown in FIG. FIG. 2 is a front view of the airbag device shown in FIG. FIG. 4 is a schematic diagram showing a schematic configuration of the airbag in a plan view in FIGS. 4A-A cross-sectional view Plan view of the outer panel that constitutes the airbag FIG. 1 is a diagram showing a first stage of an airbag deployment procedure by the airbag device according to the first embodiment; FIG. 13 is a diagram showing a second stage of the procedure for deploying the airbag by the airbag device according to the first embodiment; FIG. 13 is a diagram showing a third stage of the procedure for deploying the airbag by the airbag device according to the first embodiment. FIG. 13 is a diagram showing a fourth stage of the procedure for deploying the airbag by the airbag device according to the first embodiment. FIG. 13 is a diagram showing a fifth stage of the procedure for deploying the airbag by the airbag device according to the first embodiment. FIG. 13 is a diagram showing a sixth stage of the procedure for deploying the airbag by the airbag device according to the first embodiment. FIG. 13 is a diagram showing a seventh stage of the procedure for deploying the airbag by the airbag device according to the first embodiment. First modified example of sub-bag deployment timing control method Second Modification of Sub-bag Deployment Timing Control Method Third modified example of sub-bag deployment timing control method FIG. 13 is a perspective view of an airbag device according to a second embodiment when the airbag is deployed; FIG. 18 is a side view of the airbag device shown in FIG. FIG. 18 is a front view of the airbag device shown in FIG. FIG. 20 is a schematic diagram showing a schematic configuration of the airbag in FIGS. 17 to 19 in a plan view; 20 - B-B cross section FIG. 13 is a diagram showing a fifth stage of the procedure for deploying an airbag by the airbag device according to the second embodiment. FIG. 13 is a diagram showing a sixth stage of the procedure for deploying the airbag by the airbag device according to the second embodiment. FIG. 13 is a diagram showing a seventh stage of the procedure for deploying the airbag by the airbag device according to the second embodiment. First modified example of sub-bag deployment timing control method Second Modification of Sub-bag Deployment Timing Control Method Third modified example of sub-bag deployment timing control method

The following describes the embodiments with reference to the attached drawings. To facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicate descriptions are omitted.

In the following description, the x, y, and z directions shown in each drawing are perpendicular to each other. The x direction is the front-to-rear direction of the vehicle, with the positive x direction being the front of the vehicle and the negative x direction being the rear of the vehicle. The y direction is the width direction of the vehicle, with the positive y direction being the right side of the vehicle and the negative y direction being the left side of the vehicle. The z direction is the up-down direction, with the positive z direction being the top and the negative z direction being the bottom.

[First embodiment]
The first embodiment will be described with reference to FIGS.

The configuration of the airbag device 10 according to the first embodiment will be described with reference to Figures 1 to 5. Figure 1 is a perspective view of the airbag device 10 according to the first embodiment when the airbag is deployed. Figure 2 is a side view of the airbag device 10 shown in Figure 1. Figure 3 is a front view of the airbag device 10 shown in Figure 1. Figure 4 is a schematic diagram showing the general configuration of the airbag 20 in Figures 1 to 3 in a plan view. Figure 5 is a cross-sectional view taken along line A-A in Figure 4.

As shown in Figures 1 to 5, the airbag device 10 is mounted on a seat 60 of a vehicle. The seat 60 is composed of a seat portion 61 on which an occupant D sits, a seat back 62 whose lower end is connected to the rear end of the seat portion 61, and a headrest 63 provided at the upper end of the seat back 62. A frame 64 is disposed inside the seat back 62. Although not shown in Figures 1 to 3, the seat 60 is also equipped with typical elements that are mounted on a vehicle seat, such as a seat belt, tongue, buckle, and retractor.

In this embodiment, the seat 60 on which the airbag device 10 is mounted is exemplified as a front seat on the right side of the vehicle. In this case, the positive y direction is the outside of the vehicle, and the negative y direction is the inside of the vehicle.

When an occupant D is seated in a seat 60, the airbag device 10 uses an inflated airbag 20 to protect the occupant D from collisions in all directions, including the front, rear, left and right. The airbag 20 covers the headrest 63 of the seat 60 and the area around the head H of the occupant D seated in the seat 60, and is formed in a cylindrical shape that is open at the top and bottom.

Figures 1 to 5 show a crash test dummy as a model of the occupant D to be protected, seated in the seat portion 61 of the seat 60. The dummy is, for example, a WorldSID (World Side Impact Dummy) AM50 (50th percentile American adult male). This dummy is seated in a standard seating position (normal state) defined by the crash test method, and the seat 60 is located in a standard setting position corresponding to the seating position. The head H of the dummy faces forward of the vehicle (the front side of the seat 60).

The airbag device 10 comprises an airbag 20, an inflator 30, and a housing 40.

The airbag 20 is configured as a cylindrical integrated bag that inflates and deploys to cover the head H of the occupant D from the front and both left and right sides. More specifically, the airbag 20 has a rear inflatable section 21, a pair of side inflatable sections 22A, 22B, and a pair of sub-bags 23A, 23B.

The rear inflation section 21 deploys at a position rearward of the headrest 63 so as to face the headrest 63 and the seat back 62. As shown in FIG. 4, the rear inflation section 21 is connected at both ends in the y direction to the rear ends of the pair of side inflation sections 22A, 22B via rear bends 74A, 74B. The rear bends 74A, 74B bend at approximately a right angle toward the positive x direction, causing the pair of side inflation sections 22A, 22B to extend forward from the rear inflation section 21, as shown in FIGS. 1, 2, and 4.

The pair of side inflatable sections 22A, 22B are disposed on the left and right of the head H of the occupant D, respectively. The pair of side inflatable sections 22A, 22B are formed so that the vertical dimension is longer on the front side than on the rear side, and is longer on the lower side. The length on the front side is approximately the same as the vertical dimension from above the head H of the occupant D to a position in front of the chest.

As shown in Figures 1 to 3, the upper portions of the pair of side inflatable sections 22A and 22B are provided with vertices 29A and 29B, respectively, which protrude upward from the other portions. The vertices 29A and 29B are formed at a height that allows them to come into contact with the ceiling of the vehicle compartment.

As shown in Figures 3 and 4, the pair of lateral expansion sections 22A, 22B are joined to each other along the z direction at approximately the center position in the y direction by a central joint 76, so that they are arranged side by side in front of the head H of the occupant D and can completely block the area in front of the head H.

In this way, the airbag 20 is formed into a doughnut shape that surrounds the head H of the occupant D in all directions, including the front-to-back and left-to-right directions, by joining both ends of the integrated bag body with a central joint 76.

In addition, by arranging the central joint 76 in the center of the width direction of the pair of side inflation sections 22A, 22B, as shown in FIG. 4, a forward recess 26 is formed in the approximate center of the y direction of the side inflation sections 22A, 22B when viewed from the occupant D side. The forward recess 26 extends in the z direction over the range of the central joint 76. The presence of the forward recess 26 on the inner surfaces of the side inflation sections 22A, 22B increases the contact area of the inner surfaces of the side inflation sections 22A, 22B with the head H, and also diversifies the opposing angles, thereby increasing the directions in which the airbag 20 can absorb impacts on the front side of the vehicle, and protecting the occupant D from collisions in a wider range of directions.

The upper end positions of the pair of side inflatable sections 22A, 22B may be located above the top of the head H of the occupant D. In addition, the lower end positions are set to cover the chest of the occupant D in this embodiment, but may be located at a position that covers at least the head H of the occupant D, and may be shorter than the dimensions of this embodiment shown in Figures 1 to 5.

The pair of sub-bags 23A, 23B are provided on the center side of the seat 60 and on the front side of the seat 60 from the side inflation sections 22A, 22B, respectively. As shown in FIG. 5, the pair of sub-bags 23A, 23B are connected to the lower parts of the side inflation sections 22A, 22B when they are fully inflated. The sub-bags 23A, 23B extend from the lower ends of the side inflation sections 22A, 22B to a height at least up to the chest of the occupant D. As a result, the pair of sub-bags 23A, 23B are arranged side by side in the y direction behind the side inflation sections 22A, 22B and are arranged parallel to the front parts of the side inflation sections 22A, 22B, so that the front parts of the side inflation sections 22A, 22B and the sub-bags 23A, 23B are arranged in a double manner in front of the chest of the occupant D.

The sub-bags 23A, 23B only need to be connected to at least the side inflation sections 22A, 22B, and the connection position may be other than the lower part of the side inflation sections 22A, 22B. The upper end position of the sub-bags 23A, 23B when inflated may be higher than the height of the chest of the occupant D (for example, a position higher than the head H of the occupant D). However, if the upper end position of the sub-bags 23A, 23B is kept at the chest level as in this embodiment and the vertical dimension of the sub-bags 23A, 23B when inflated is shortened, the deployment time of the sub-bags 23A, 23B can be shortened, which is advantageous.

As shown in FIG. 5, the airbag 20 has an inflator 30 attached to the inflator insertion port 25 of the rear inflation section 21, and gas is supplied from the inflator 30. The airbag 20 has a gas flow path formed from the rear inflation section 21 to one side inflation section 22A and one sub-bag 23A in that order, and also has a gas flow path formed from the rear inflation section 21 to the other side inflation section 22B and the other sub-bag 23B in that order.

After the rear inflation section 21 and the side inflation sections 22A, 22B are deployed, the sub-bags 23A, 23B are inflated to reduce the distance between the pair of side inflation sections 22A, 22B and the occupant D seated in the seat 60. More specifically, as shown in FIG. 5, the sub-bags 23A, 23B have communication holes 24 that connect the sub-bags 23A, 23B and the side inflation sections 22A, 22B, and the area of the communication holes 24 is adjusted to control the sub-bags 23A, 23B to inflate after the side inflation sections 22A, 22B are deployed.

Note that "after the rear inflation section 21 and the side inflation sections 22A, 22B are deployed" does not necessarily mean after the rear inflation section 21 and the side inflation sections 22A, 22B are fully inflated and deployed, but also includes timing before full inflation, such as when the side inflation sections 22A, 22B have landed in front of the occupant D even though gas supply is continuing, or when there is evidence that the restraining surface of the airbag 20 is positioned in front of the occupant D even if the airbag 20 has not yet landed completely in front of the occupant D (for example, when the tip portions of the side inflation sections 22A, 22B have moved forward of the head H of the occupant D).

The airbag device 10 of the first embodiment is provided with such sub-bags 23A and 23B, and since the sub-bags 23A and 23B are not yet inflated during the deployment of the rear inflation section 21 and the side inflation sections 22A and 22B, the clearance between the airbag 20 and the occupant D can be increased. As a result, the airbag 20 is less likely to interfere with the occupant D during deployment of the airbag 20, and the airbag 20 can be easily positioned in front of the occupant D, so that the airbag 20 can be smoothly deployed in front of the occupant D. Furthermore, since the sub-bags 23A and 23B are inflated in front of the occupant D after the deployment of the rear inflation section 21 and the side inflation sections 22A and 22B, the clearance between the airbag 20 and the occupant D can be reduced after the deployment of the airbag 20. As a result, the airbag 20 can restrain the occupant D at an earlier timing, and the restraint performance can be improved. Therefore, the airbag device 10 of the first embodiment can smoothly deploy the airbag 20 in front of the occupant D, and can also improve the restraint effect after the airbag 20 is deployed.

Figure 6 is a plan view of the outer panel 51 that constitutes the airbag 20. Note that the inner panel 52 is also configured symmetrically to the outer panel 51 in the left-right direction of the drawing.

The outer panel 51 and the inner panel 52 are overlapped and sewn along the outer peripheral sewing line 56 of the peripheral portion to form an integrated bag body. In the panel diagram shown in FIG. 6, the outer panel 51 and the inner panel 52 have the rear inflatable portion 21 located in the center, and the side inflatable portions 22A and 22B are located on both sides of the rear inflatable portion 21 in the width direction (left and right direction in FIG. 6) at a slight downward incline. Sub-bags 23A and 23B are located from the outer ends and lower ends of the side inflatable portions 22A and 22B in the width direction toward the center. As shown in FIG. 4, the outer panel 51 forms an outer surface that faces outward when the airbag 20 is deployed, and the inner panel 52 forms an inner surface that faces the center of the head H when the airbag 20 is deployed.

Circular stitches 55A, 55B sewn in an oval shape are provided between the rear inflation section 21 and the side inflation sections 22A, 22B at approximately the center in the vertical direction, joining the outer panel 51 and the inner panel 52. These circular stitches 55A, 55B promote bending of the bag body, forming rear bent sections 74A, 74B. In addition, by partially joining the outer panel 51 and the inner panel 52 with the circular stitches 55A, 55B, the capacity of the airbag 20 can be reduced.

A pair of circular stitch patches 55C, 55D are provided along the front-rear direction at approximately the center of the height direction of the lateral expansion sections 22A, 22B. The circular stitch patches 55C, 55D are circular patches placed on the outside of the outer panel 51 and the inner panel 52, and these patches are sewn between the outer panel 51 and the inner panel 52 to join the outer panel 51 and the inner panel 52. The circular stitch patches 55C, 55D can reinforce the stitched parts by placing the patches on the outside.

In the side inflation sections 22A, 22B, a pair of circular stitch patches 55C, 55D are provided along the front-rear direction, and a straight line is sewn between them along the front-rear direction. This divides the gas flow path of the side inflation sections 22A, 22B into two in the height direction, and regulates the thickness of the airbag 20 when inflated. Furthermore, in the side inflation sections 22A, 22B, a circular stitch patch 55C, 55D is also provided below the rear one of the pair of circular stitch patches 55C, 55D in the front-rear direction. In other words, an area is formed where two circular stitch patches 55C, 55D are provided in the height direction. In this area, the thickness of the airbag 20 when inflated is further suppressed compared to other areas.

At the widthwise outer ends of the lateral expansion sections 22A, 22B, sewing lines 76A, 76B are provided along the vertical direction, and these sewing lines 76A, 76B are joined to each other to form the central joint 76.

The procedure for deploying the airbag 20 by the airbag device 10 of the first embodiment will be described with reference to Figures 7 to 13. Figures 7 to 13 are diagrams respectively showing the first to seventh stages of the procedure for deploying the airbag 20 by the airbag device 10 of the first embodiment.

First, in the first stage shown in FIG. 7, that is, during normal operation (when the airbag device 10 is not activated), the airbag 20 is folded and stored in the storage section 40 inside the seat back. When the vehicle is subjected to an impact of a predetermined threshold or greater due to a collision or the like, the inflator 30 is activated by the ECU, and gas begins to be supplied from the inflator 30 to the airbag 20.

In the second stage shown in FIG. 8, when gas begins to be supplied from the inflator 30, gas is first supplied to the upper bellows fold 72, which begins to inflate. The bellows fold 72 breaks the surface of the seat back 62 while expanding its bellows shape, advancing toward the rear of the seat, and begins to expand upward and toward the rear of the seat.

9, the rear inflatable portion 21 is formed when the bellows-folded portion 72 is fully deployed. After that, when gas starts to be supplied to the roll-folded portion 71, the roll-folded portion 71 starts to expand from the roll-folded state. At this time, due to the expansion force generated by the expansion, the roll-folded portion 71 receives a reaction force toward the front and upper side of the vehicle from the rear inflatable portion 21 deployed on the back side of the seat. Due to this reaction force, the roll-folded portion 71 deploys diagonally upward so as to climb over the headrest 63. In other words, the rear inflatable portion 21, which deploys first, functions as a base for promoting the deployment direction of the roll-folded portion 71 forward. In addition, since the roll-folded portion 71 is wound in an upward direction, it deploys by rotating in a downward direction. As the expansion of the roll-folded portion 71 progresses further, the side inflatable portions 22A and 22B start to deploy. The side inflatable portions 22A and 22B expand upward, and the remaining portion of the roll-folded portion 71 deploys forward along the ceiling of the vehicle.

In the fourth stage shown in FIG. 10, the rear parts of the side inflation sections 22A, 22B are formed from the rolled folded section 71 to cover the sides of the head H of the occupant D. At this time, the remaining parts of the rolled folded section 71 advance forward of the head H, and the tops 29A, 29B of the side inflation sections 22A, 22B hit the ceiling, causing the upward deployment direction to change to downward due to the reaction force from the ceiling, and they begin to deploy downward from the vehicle ceiling.

In the fifth stage shown in FIG. 11, the front portions of the side inflation sections 22A, 22B are formed from the rolled fold 71, and cover the front portion of the head H of the occupant D. At this time, the sub-bags 23A, 23B disposed at the tips of the front portions of the side inflation sections 22A, 22B have not yet inflated, so there is a large clearance (gap) between the front portions of the side inflation sections 22A, 22B and the head H of the occupant D, as shown by arrow A in FIG. 11. This makes it easier for the airbag 20 to deploy forward of the head H of the occupant D, making it easier to cover the head D.

12, the front parts of the side inflation parts 22A, 22B inflate further downward, and when the deployment of the side inflation parts 22A, 22B is completed, the airbag 20 is formed to cover the occupant D in all directions in the front, back, left and right directions. At this time, the sub-bags 23A, 23B are positioned in front of the chest of the occupant D, but since it is the initial stage of expansion, there is still a clearance (gap) between the front parts of the side inflation parts 22A, 22B and the head H of the occupant D as shown by arrow B in FIG. 12, making it easy for the sub-bags 23A, 23B to descend to the position in front of the occupant's chest. After the deployment of the side inflation parts 22A, 22B, the sub-bags 23A, 23B begin to inflate, and as shown by arrow C in FIG. 12, the sub-bags 23A, 23B deploy in the direction of the chest of the occupant D, reducing the clearance with the occupant D.

In addition, in this embodiment, as described above, the pair of sub-bags 23A, 23B are connected to the lower parts of the side inflation sections 22A, 22B by the communication holes 24 when the inflation is complete. Therefore, after the side inflation sections 22A, 22B are deployed, sufficient gas is supplied to the lower parts of the side inflation sections 22A, 22B that are farthest from the gas supply source, and gas begins to be supplied from the side inflation sections 22A, 22B to the sub-bags 23A, 23B via the communication holes 24 after the lower parts of the side inflation sections 22A, 22B are fully inflated. This makes it possible to increase the time difference in the inflation timing of the sub-bags 23A, 23B relative to the side inflation sections 22A, 22B, and to reliably delay the inflation.

Then, in the seventh stage shown in FIG. 13, the deployment of the sub-bags 23A and 23B is completed, and there is almost no clearance between the sub-bags and the chest of the occupant D.

The first to third modified examples of the deployment timing control method for the sub-bags 23A and 23B will be described with reference to Figures 14 to 16. Figures 14 to 16 correspond to the side cross-sectional views of Figure 5.

In the first modified example shown in FIG. 14, the communication hole 24 is blocked by a pressure valve 27 that breaks at a predetermined pressure. The pressure valve 27 breaks due to the pressure inside the lateral inflation sections 22A, 22B that rises as the lateral inflation sections 22A, 22B expand. This opens the communication hole 24 and supplies gas to the sub-bags 23A, 23B. With this configuration, it is possible to control the expansion of the sub-bags 23A, 23B after the deployment of the lateral inflation sections 22A, 22B.

In the second modified example shown in FIG. 15, the opening of the communication hole 24 is covered by a tube 28 that can be expanded by gas supply in a deflated state, and the communication hole 24 is closed by sewing with a tear seam 31. The tear seam 31 is broken by supplying gas to the tube 28 to expand the tube 28. This separates the tube 28 from the opening of the communication hole 24, opening the communication hole 24 and supplying gas to the sub-bags 23A and 23B. With this configuration, it is possible to control the expansion of the sub-bags 23A and 23B after the deployment of the lateral expansion sections 22A and 22B.

In the third modified example shown in FIG. 16, a second inflator 32 is provided in addition to the inflator 30 that supplies gas to the airbag 20, and the sub-bags 23A, 23B are inflated by the gas supplied from the second inflator 32. In this case, the sub-bags 23A, 23B are not connected to the side inflatable portions 22A, 22B. The second inflator 32 is installed, for example, on the seat 60 in the same manner as the inflator 30, and is connected to the sub-bags 23A, 23B by a supply path 33. In this configuration, by delaying the activation timing of the second inflator 32 from the inflator 30, it is possible to control the sub-bags 23A, 23B to inflate after the side inflatable portions 22A, 22B are inflated.

[Second embodiment]
The second embodiment will be described with reference to FIGS.

The configuration of the airbag device 100 according to the second embodiment will be described with reference to Figures 17 to 21. Figure 17 is a perspective view of the airbag device 100 according to the second embodiment when the airbag is deployed. Figure 18 is a side view of the airbag device 100 shown in Figure 17. Figure 19 is a front view of the airbag device 100 shown in Figure 17. Figure 20 is a schematic diagram showing the general configuration of the airbag 200 in Figures 17 to 19 in a plan view. Figure 21 is a cross-sectional view taken along line B-B in Figure 20. Figures 17 to 21 correspond to Figures 1 to 5 of the first embodiment.

As shown in Figures 17 to 21, the airbag device 100 of the second embodiment differs from the first embodiment in that the sub-bag 210 of the airbag 200 is provided between the rear inflatable portion 21 and the seat 60 (headrest 63).

As shown in FIG. 21, the sub-bag 210 is connected to the lower part of the rear inflation section 21 when inflation is complete. The sub-bag 210 extends from the lower end of the rear inflation section 21 to at least the upper end position of the headrest 63 in the up-down direction. Also, as shown in FIG. 20, the sub-bag 210 extends across at least the width of the headrest 63 in the left-right width direction. This results in the sub-bag 210 and the rear inflation section 21 being positioned behind the headrest 63 in a double configuration.

Note that the sub-bag 210 only needs to be connected to at least the rear inflatable section 21, and the connection position may be other than the lower part of the rear inflatable section 21.

After the rear inflation section 21 and the side inflation sections 22A, 22B are deployed, the sub-bag 210 is inflated to reduce the distance between the pair of side inflation sections 22A, 22B and the occupant D seated in the seat 60. More specifically, as shown in FIG. 21, the sub-bag 210 has a communication hole 211 that communicates between the sub-bag 210 and the rear inflation section 21, and the sub-bag 210 is controlled to inflate after the rear inflation section 21 is deployed by adjusting the area of the communication hole 211.

The airbag device 100 of the second embodiment, like the first embodiment, is provided with such a sub-bag 210, and since the sub-bag 210 is not yet inflated during the deployment of the rear inflation section 21 and the side inflation sections 22A and 22B, the clearance between the airbag 200 and the occupant D can be increased. As a result, the airbag 200 is less likely to interfere with the occupant D during deployment of the airbag 200, and the airbag 200 can be easily positioned in front of the occupant D, so that the airbag 200 can be smoothly deployed in front of the occupant D. Furthermore, as the sub-bag 210 inflates behind the occupant D after the deployment of the rear inflation section 21 and the side inflation sections 22A and 22B, the clearance between the airbag 200 and the occupant D can be reduced after the deployment of the airbag 200. As a result, the airbag 200 can restrain the occupant D at an earlier timing, and the restraint performance can be improved. Therefore, the airbag device 100 of the second embodiment can smoothly deploy the airbag 200 in front of the occupant D, and can also improve the restraint effect after the airbag 200 is deployed.

The procedure for deploying the airbag 200 by the airbag device 100 of the second embodiment will be described with reference to Figures 22 to 24. Figures 22 to 24 are diagrams showing the fifth to seventh stages of the procedure for deploying the airbag 200 by the airbag device 100 of the second embodiment, respectively. Note that the first to fourth stages are the same as those of the first embodiment (Figures 7 to 10), so their description will be omitted.

22, the front portions of the side inflation portions 22A, 22B are formed to cover the front portion of the head H of the occupant D. At this time, the sub-bag 210 disposed between the rear inflation portion 21 and the seat 60 has not yet inflated, so there is a large clearance (gap) between the front portions of the side inflation portions 22A, 22B and the head H of the occupant D, as shown by the arrow E in FIG. 22. This makes it easier for the airbag 200 to deploy forward of the head H of the occupant D, making it easier to cover the head D.

23, the front parts of the side inflation sections 22A, 22B inflate further downward, and when the deployment of the side inflation sections 22A, 22B is completed, the airbag 20 is formed to cover the occupant D in all directions, front to back, left to right. At this time, because the sub-bag 210 is in the early stage of inflation, there is still a clearance (gap) between the front parts of the side inflation sections 22A, 22B and the head H of the occupant D, as shown by the arrow F in FIG. 23.

24, after the side inflation sections 22A, 22B are deployed, the sub-bag 210 begins to inflate, and the sub-bag 210 deploys rearward as shown by arrow G in FIG. 24. This causes the entire airbag 200 to move rearward as shown by arrow H, and the front portions of the side inflation sections 22A, 22B move closer to the occupant D, reducing the clearance between the front portions of the side inflation sections 22A, 22B and the occupant D. When the deployment of the sub-bag 210 is complete, there is almost no clearance between the occupant D's chest as shown in FIG. 24.

The first to third modified examples of the deployment timing control method for the sub-bag 210 will be described with reference to Figures 25 to 27. Figures 25 to 27 correspond to the side cross-sectional views of Figure 21.

In the first modified example shown in FIG. 25, the communication hole 211 is blocked by a pressure valve 212 that breaks at a predetermined pressure. The pressure valve 212 breaks due to the pressure inside the rear inflation section 21 that rises as the rear inflation section 21 expands. This opens the communication hole 211 and supplies gas to the sub-bag 210. With this configuration, it is possible to control the sub-bag 210 to inflate after the rear inflation section 21 is deployed.

In the second modified example shown in FIG. 26, a tube 213 that can be expanded by gas supply is in a deflated state to cover the opening of the communication hole 211, and the communication hole 211 is closed by sewing with a tear seam 214. The tear seam 214 is broken by supplying gas to the tube 213 to expand the tube 213. This separates the tube 213 from the opening of the communication hole 211, opening the communication hole 211, and supplying gas to the sub-bag 210. With this configuration, it is possible to control the expansion of the sub-bag 210 after the rear expansion section 21 is deployed.

In the third modified example shown in FIG. 27, a second inflator 215 is provided in addition to the inflator 30 that supplies gas to the airbag 200, and the sub-bag 210 is inflated by gas supplied from the second inflator 215. In this case, the sub-bag 210 is not connected to the rear inflation section 21. The second inflator 215 is installed, for example, in the seat 60 in the same way as the inflator 30, and is connected to the sub-bag 210. In this configuration, by delaying the activation timing of the second inflator 215 compared to the inflator 30, it is possible to control the sub-bag 210 to inflate after the rear inflation section 21 is inflated.

The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of each of the above-mentioned specific examples can be combined in different ways as appropriate, as long as no technical contradictions arise.

REFERENCE SIGNS LIST 10, 100 Airbag device 20, 200 Airbag 21 Rear inflatable portion 22A, 22B Side inflatable portion 23A, 23B, 210 Sub-bag 24, 211 Communication hole 27, 212 Pressure valve 28, 213 Tube 31, 214 Tear seam 30 Inflator 32, 215 Second inflator 60 Seat D Occupant

Claims (16)

An airbag,
A rear inflatable portion that deploys on the back side of the seat;
A pair of side inflation portions extending forward from both sides of the rear inflation portion in the seat width direction and connected to each other in front of the seat;
a front portion of the airbag that is disposed in front of an occupant seated in the seat after the rear inflation portion and the side inflation portion are deployed , and a sub-bag that inflates to reduce a clearance between the front portion and the occupant ;
An airbag comprising: The sub-bag is provided on the center side of the seat and in front of the seat from the side inflatable portion.
2. The airbag of claim 1. The sub-bag is connected to a lower portion of the side inflation portion when the inflation is completed.
3. The airbag of claim 2. The sub-bag extends from a lower end of the side inflation portion to at least a height in front of the occupant's chest.
4. The airbag according to claim 2 or 3. a communication hole that communicates between the sub-bag and the lateral inflatable portion,
The sub-bag is controlled to inflate after the side inflation section is deployed by adjusting the area of the communication hole.
The airbag according to any one of claims 2 to 4. a communication hole that communicates between the sub-bag and the lateral inflatable portion,
The communication hole is blocked by a pressure valve that breaks at a predetermined pressure, and the pressure valve breaks and opens the communication hole due to the pressure inside the side inflation section that rises as the side inflation section expands, thereby controlling the expansion of the sub-bag after the side inflation section is deployed.
The airbag according to any one of claims 2 to 4. a communication hole that communicates between the sub-bag and the lateral inflatable portion,
a tube that can be expanded by supplying gas is deflated to cover the opening of the communication hole, and the communication hole is closed by sewing with a tear seam;
The sub-bag is controlled to inflate after the side inflation section is deployed by supplying gas to the tube to inflate the tube, thereby breaking the tear seam and separating the tube from the opening to open the communication hole.
The airbag according to any one of claims 2 to 4. a second inflator separate from the inflator that supplies gas to the airbag;
The sub-bag is expanded by the gas supplied from the second inflator, so that the sub-bag is controlled to inflate after the side expansion portion is expanded.
The airbag according to any one of claims 2 to 4. In the panel view of the airbag, the rear inflatable portion is disposed in the center, the side inflatable portions are disposed on both sides of the rear inflatable portion in the width direction at an incline, and the sub-bag is disposed from the end of the side inflatable portion toward the center.
The airbag according to any one of claims 2 to 7. The sub-bag is provided between the rear inflatable portion and the seat.
2. The airbag of claim 1. The sub-bag is connected to a lower portion of the rear inflation portion when the inflation is completed.
11. The airbag of claim 10. a communication hole that communicates between the sub-bag and the rear inflatable portion,
The sub-bag is controlled to inflate after the rear inflation section is deployed by adjusting the area of the communication hole.
12. The airbag according to claim 10 or 11. a communication hole that communicates between the sub-bag and the rear inflatable portion,
The communication hole is blocked by a pressure valve that breaks at a predetermined pressure, and the pressure valve breaks and opens the communication hole due to the pressure inside the rear inflation section that rises as the rear inflation section expands, thereby controlling the expansion of the sub-bag after the rear inflation section is deployed.
12. The airbag according to claim 10 or 11. a communication hole that communicates between the sub-bag and the rear inflatable portion,
a tube that can be expanded by supplying gas is deflated to cover the opening of the communication hole, and the communication hole is closed by sewing with a tear seam;
The sub-bag is controlled to inflate after the rear inflation section is deployed by supplying gas to the tube to inflate the tube, thereby breaking the tear seam and separating the tube from the opening to open the communication hole.
12. The airbag according to claim 10 or 11. a second inflator separate from the inflator that supplies gas to the airbag;
The sub-bag is expanded by the gas supplied from the second inflator, so that the sub-bag is controlled to be inflated after the rear expansion section is expanded.
12. The airbag according to claim 10 or 11. An inflator,
The airbag according to any one of claims 1 to 15, which is deployed by gas supplied from the inflator;
An airbag device comprising:

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