JP2021054244A - Air bag exhaust structure - Google Patents

Abstract

To stably discharge an expansion gas.SOLUTION: An exhaust structure ES is formed by sewing peripheral edge parts of a pair of inner fabric parts 53 overlapped in a thickness direction by an inner peripheral edge sewing part 61, and is applied to an air bag 30 having an inner bag 50 which is expanded by an expansion gas. The inner peripheral edge sewing part 61 is released from sewing in a partial region, whereby a pair of terminal parts 62 which is separated from each other, is formed on the inner peripheral edge sewing part 61. A notch part 63, which passes between both terminal parts 62 and enters inside a region surrounded by the inner peripheral edge sewing part 61, is formed on a part of the peripheral edge part of each inner fabric part 53. Each inner fabric part 53 is provided with an exhaust reinforcement sewing part 64 which reinforces at least a part of a peripheral portion of the notch part 63. The exhaust reinforcement sewing part 64 for each inner fabric part 53 crosses the inner peripheral edge sewing part 61 at a point on a side opposite to the notch part 63 with each terminal part 62 interposed therebetween.SELECTED DRAWING: Figure 5

Description

The present invention relates to an airbag exhaust structure that discharges excess expansion gas from an airbag that expands and expands with expansion gas to protect occupants when an impact is applied to a vehicle such as a vehicle.

A side airbag device equipped with an airbag and a gas generator is effective as a device for protecting an occupant seated on a vehicle seat when an impact is applied to a side wall portion of the vehicle due to a side collision or the like.

The airbag is generally formed by suturing the peripheral edges of a pair of cloth portions stacked in the vehicle width direction at the peripheral sewing portion, and has an expanding portion that is expanded by the expanding gas. The gas generator is arranged inside the airbag.

According to the side airbag device having the above configuration, when an impact is applied to the side wall portion due to a side collision or the like, expansion gas is supplied from the gas generator to the expansion portion. The expansion gas expands and expands the expansion portion. The expansion portion is interposed between the occupant and the side wall portion that enters inward in the vehicle width direction to restrain the occupant.

The airbag is provided with an exhaust structure for discharging excess expansion gas in the expanded and expanded expansion portion.
For example, in Patent Document 1, as the exhaust structure, a pair of terminal portions separated from each other are formed in the peripheral sewn portion by releasing the suture in a part of the peripheral sewn portion. The area between the peripheral edges of both cloth portions and sandwiched between both terminal portions functions as an exhaust hole.

According to the above-mentioned type of exhaust structure, excess expansion gas in the expansion portion is discharged to the outside of the expansion portion through the exhaust hole. Due to the restraint of the occupant by the expansion portion and the decrease in internal pressure due to the discharge of the expansion gas from the exhaust hole, the impact from the side transmitted to the occupant through the side wall portion is alleviated. In this way, the occupant's upper body is protected from impact.

Japanese Unexamined Patent Publication No. 2015-85768

However, in the exhaust structure described in Patent Document 1, the shape of the exhaust hole changes according to the internal pressure of the airbag. The exhaust hole is closed when the internal pressure before the occupant is restrained by the airbag is low. The exhaust hole is opened when the internal pressure of the airbag rises due to occupant restraint. Moreover, the opening area of the exhaust hole differs depending on the internal pressure. As the opening area of the exhaust hole changes, the amount of expansion gas discharged from the exhaust hole changes. Therefore, in the exhaust structure described in Patent Document 1, it is difficult to stably discharge the expansion gas.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exhaust structure for an airbag capable of stably discharging an expansion gas.

The exhaust structure of the airbag that solves the above problems is formed by sewing the peripheral edges of a pair of cloth portions stacked in the thickness direction with the peripheral sewn portion, and has an expanding portion that is expanded by the expanding gas. In the exhaust structure applied to the bag, when the peripheral sewn portion is released from stitching in a part of the area, a pair of terminal portions separated from each other is formed on the peripheral sewn portion, and the peripheral edge of each cloth portion is formed. A cut portion is formed in a part of the portion so as to pass between the two terminal portions and enter the inside of the area surrounded by the peripheral sewn portion, and each cloth portion has a cut portion of the cut portion in the cloth portion. An exhaust reinforcement sewn portion that reinforces at least a part of the peripheral portion is provided, and the exhaust reinforcement sewn portion for each cloth portion is formed on the peripheral sewn portion at a position opposite to the notch portion with each terminal portion interposed therebetween. It intersects.

According to the above configuration, when an impact due to a collision or the like is applied to the vehicle and the expansion gas is supplied to the expansion portion of the airbag, the expansion portion expands and the occupant is restrained.
On the other hand, with the expansion of the expanded portion, the pair of cloth portions are pulled to both sides in the thickness direction of the cloth portion. Along with this, the cut portion of each cloth portion is pulled in the same direction. When the expanded portion is expanded, the inner portion of the cut portion of each cloth portion is opened from the terminal portion. This inner portion functions as an exhaust hole that communicates the inside and the outside of the expansion portion. When the expansion portion is expanded, the exhaust hole is opened to the same extent regardless of the degree of occupant restraint by the expansion portion. The opening shape of the exhaust hole hardly changes. Therefore, the expansion gas in the expansion portion is stably discharged to the outside of the expansion portion through the exhaust holes opened as described above.

The restraint of the occupant by the expansion portion and the decrease in the internal pressure of the expansion portion due to the discharge of the expansion gas alleviate the impact applied to the occupant.
It should be noted that the peripheral sewn portion may fray starting from the terminal portion due to the pair of cloth portions being pulled along with the expansion of the expanded portion. However, the peripheral sewn portion is reinforced by the exhaust reinforcing sewn portion that intersects the peripheral sewn portion at a portion opposite to the cut portion with each terminal portion sandwiched between them. Therefore, even if the peripheral sewn portion is frayed, the frayed portion is received by the exhaust reinforcing sewn portion. By this receiving, the peripheral sewn portion is suppressed from fraying to the side farther from the cut portion than the exhaust reinforcing sewn portion, and the shape of the exhaust hole is maintained.

In the exhaust structure of the airbag, the exhaust reinforcement sewn portion for each cloth portion has a linear shape and surrounds the notch portion, and the exhaust reinforcement sewn portion for each cloth portion is the exhaust reinforcement sewn portion of the same cloth portion. It is preferable that both ends intersect the peripheral sewn portion.

According to the above configuration, each cloth portion is reinforced by a linear exhaust reinforcing sewn portion provided so as to surround the cut portion. Therefore, the pair of cloth portions is pulled along with the expansion of the expansion portion, and the tear is received by the exhaust reinforcing sewn portion regardless of the direction in which the cloth portions start to tear starting from the cut portion. By this receiving, it is suppressed that the cloth portion is torn to the side away from the cut portion beyond the exhaust reinforcing sewn portion.

In the exhaust structure of the airbag, it is preferable that the exhaust reinforcing sewn portion for each cloth portion is provided along the shape of the cut portion.
According to the above configuration, each cloth portion is reinforced by a linear exhaust reinforcing sewn portion provided along the notch portion. The distance from the notch to the exhaust reinforcement sewn part is about the same at any part of the notch. Therefore, even if the cloth portion starts to tear from the cut portion, it can be stopped at a position as far away from the cut portion.

In the exhaust structure of the airbag, it is preferable that the cut portion of each cloth portion has a semicircular shape.
According to the above configuration, as the expansion portion expands, as described above, the pair of cloth portions are pulled to both sides in the thickness direction of the cloth portion. Along with this, the cut portion of each cloth portion is pulled in the same direction. At this time, if the cut portion has an angular shape such as a rectangle, the stress generated by the tension may be concentrated on the corner portion. In this respect, as described in the above configuration, if the cut portion of each cloth portion has a semicircular shape, the stress generated by the tension is unlikely to be concentrated.

According to the exhaust structure of the airbag, the expansion gas can be discharged stably.

A side view showing a vehicle seat equipped with the side airbag device together with an occupant and an airbag in one embodiment in which the exhaust structure of the airbag is applied to the side airbag device. In one embodiment, a schematic plan sectional view showing the positional relationship between the vehicle seat and the side wall portion together with the occupant and the airbag. In one embodiment, a partial plan view showing a state in which the airbag module is made into a storage form and fastened to a seat frame at a storage portion. In one embodiment, a side view of an airbag module in which the airbag is deployed and non-expanded. A side sectional view showing an internal structure of the airbag module of FIG. FIG. 5 is an enlarged partial side sectional view showing an exhaust structure in FIG. An exploded perspective view of the airbag components. A schematic plan sectional view of an airbag deployed and inflated in one embodiment. A partial front view of the exhaust structure in one embodiment as viewed from the front of the vehicle. It is a figure corresponding to FIG. 6, and is the partial side sectional view which shows the modification of the exhaust structure. It is a figure corresponding to FIG. 4, and is the side view of the airbag module which shows the modification which applied the exhaust structure to the body expansion part of the airbag body.

Hereinafter, an embodiment in which the exhaust structure of the airbag is applied to the vehicle side airbag device will be described with reference to FIGS. 1 to 9.
In the following description, the forward direction of the vehicle will be described as the front, and the reverse direction of the vehicle will be described as the rear. Further, the central portion in the vehicle width direction of the vehicle is used as a reference, the side approaching the central portion is referred to as "inside the vehicle", and the side away from the central portion is referred to as "outside the vehicle". Further, it is assumed that an occupant having the same physique as the dummy for the collision test is seated on the vehicle seat in a predetermined proper posture.

As shown in FIGS. 1 and 2, a vehicle seat 12 is arranged in the vicinity of the inside of the side wall portion 11 of the vehicle 10. Here, the side wall portion 11 refers to a vehicle component member arranged on the side portion of the vehicle 10, and mainly corresponds to a door, a pillar, or the like. For example, the side wall portion 11 corresponding to the front seat is a front door, a center pillar (B pillar), or the like. Further, the side wall portion 11 corresponding to the rear seat is a rear portion of a side door (rear door), a C-pillar, a front portion of a tire house, a rear quarter, and the like.

The vehicle seat 12 includes a seat cushion 13 and a seat back 14. The seat cushion 13 is attached to a rail (not shown) installed on the floor of the vehicle body so that the front-rear position can be adjusted. The seat back 14 is tilted so as to be located rearward from the rear portion of the seat cushion 13 toward the upper side, and the tilt angle can be adjusted. The vehicle seat 12 is arranged in the vehicle interior with the seat back 14 facing forward. The width direction of the vehicle seats 12 arranged in this way coincides with the vehicle width direction.

A storage portion 15 is provided on the outer side of the seat back 14, and the airbag module ABM, which forms the main part of the side airbag device, is incorporated in the storage portion 15. The airbag module ABM includes a gas generator 20 and an airbag 30 as main components. Next, each of these constituent members will be described.

Here, in the present embodiment, when the airbag module ABM and its constituent members are referred to as "vertical direction" and "front-rear direction", the seat back 14 of the vehicle seat 12 is used as a reference. The upright direction of the seat back 14 is the "vertical direction" of the airbag module ABM or the like, and the thickness direction of the seat back 14 is the "front-back direction" of the airbag module ABM or the like. As described above, since the seat back 14 is slightly inclined rearward, the "vertical direction" of the airbag module ABM or the like does not strictly match the vertical direction (vertical direction) of the vehicle 10, and is somewhat. It is tilted. Similarly, the "front-rear direction" of the airbag module ABM or the like does not match the front-rear direction (horizontal direction) of the vehicle 10, and is slightly inclined.

<Gas generator 20>
As shown in FIGS. 3 and 4, the gas generator 20 includes an inflator 21 and a retainer 22 that covers the inflator 21, and the entire gas generator 20 has an elongated shape extending in the vertical direction. Here, as the inflator 21, a type called a pyrotype is adopted. The inflator 21 has a substantially columnar shape, and a gas generator (not shown) that generates an expansion gas is housed inside the inflator 21. The inflator 21 has a gas ejection portion 21a at its upper end. Further, a harness (not shown) that serves as an input wiring for an operation signal to the inflator 21 is connected to the lower end of the inflator 21.

As the inflator 21, instead of the pyrotype using the gas generating agent, a type (hybrid type) is used in which the partition wall of the high-pressure gas cylinder filled with the high-pressure gas is broken by an explosive or the like to eject the expansion gas. May be done.

On the other hand, the retainer 22 constitutes the outer peripheral portion of the gas generator 20. The retainer 22 functions as a diffuser that controls the direction in which the expansion gas is ejected, and also has a function of fastening the inflator 21 together with the airbag 30 and the like to the seat frame 16 in the seat back 14. Most of the retainer 22 is formed into a substantially tubular shape by bending a plate material such as a metal plate.

A pair of bolts 23 are fixed to the retainer 22 as a locking member for attaching the retainer 22 to the seat frame 16. The gas generator 20 may be a combination of the inflator 21 and the retainer 22. Further, the gas generator 20 may be composed only of the inflator 21 to which the bolt 23 is fixed without using the retainer 22.

The inflator 21 and the retainer 22 are arranged in an inner tube (not shown). The inner tube is made of the same material as the main body cloth portions 34 and 35 of the airbag main body 31, which will be described later, with both upper and lower ends open and formed into a circular tubular shape having a diameter slightly larger than that of the retainer 22. The inner tube has a rectifying function that distributes the expansion gas ejected from the inflator 21 upward and downward.

<Airbag 30>
As shown in FIGS. 4, 5 and 7, the airbag 30 includes an airbag body 31, an inner bag 50, and an expansion thickness regulating unit 70.

<Airbag body 31>
The airbag body 31 constitutes the outer shell portion of the airbag 30. FIG. 4 shows an airbag module ABM in a state in which the airbag body 31 is only expanded and not inflated (hereinafter referred to as “expanded non-expanded state”). Further, FIG. 5 shows the airbag module ABM in which the airbag main body 31 of FIG. 4 is cut at the central portion in the vehicle width direction in order to show the internal structure of the airbag module ABM. Further, FIG. 7 shows a state in which each constituent member of the airbag 30, including the airbag main body 31, is expanded.

A piece of cloth (also called a base cloth, a panel cloth, etc.) 32 is used for forming the airbag main body 31. As the cloth piece 32, a material having high strength, flexibility, and easily folding, for example, a woven cloth formed by using polyester thread, polyamide thread, or the like is suitable. A fold line 33 extending in the vertical direction is set at the central portion of the cloth piece 32 in the vehicle width direction. The cloth piece 32 is folded in half along the folding line 33 and overlapped in the vehicle width direction. Here, in order to distinguish the two overlapped portions of the airbag main body 31, the one located inside the vehicle is referred to as the main body cloth portion 34, and the one located outside the vehicle is referred to as the main body cloth portion 35.

In the present embodiment, the cloth piece 32 is folded in half so that the fold line 33 is located at the rear end of the airbag body 31, but the fold line 33 is at another end, for example, the front end and the upper end. , The piece of cloth may be folded in half so as to be located at the lower end. Further, the airbag main body 31 may be composed of two pieces of cloth divided along the folding line 33. In this case, the airbag main body 31 is formed by stacking two pieces of cloth in the vehicle width direction and joining the two pieces of cloth so as to form a bag. Further, the airbag main body 31 may be composed of three or more pieces of cloth.

In the airbag main body 31, the outer shapes of the cloth portions 34 and 35 of both main bodies are in a line-symmetrical relationship with each other with the folding line 33 as the axis of symmetry. The main body cloth portions 34 and 35 are regions corresponding to many parts of the upper body of the occupant P1 when the airbag main body 31 is deployed and expanded between the vehicle seat 12 and the side wall portion 11, in the present embodiment. , It is formed in a shape and size that can occupy the region corresponding to the portion from the lumbar PP to the shoulder PS (see FIG. 1).

A strip-shaped main body reinforcing cloth 36 formed along the peripheral edge portion is superposed on the peripheral portion of each main body cloth portion 34, 35 except for the rear end portion (the portion near the folding line 33). .. The main body cloth portions 34 and 35 and the main body reinforcing cloth 36 are connected by a main body reinforcing sewing portion 37 provided along the main body reinforcing cloth 36. The main body reinforcing sewing portion 37 is formed by sewing (stitching with sewing thread) both main body reinforcing cloths 36 and both main body cloth portions 34 and 35. The peripheral edges of each of the main body cloth portions 34 and 35 are reinforced by the main body reinforcing cloth 36 and the main body reinforcing sewing portion 37.

As shown in FIGS. 4 and 5, the two main body cloth portions 34 and 35 to which the main body reinforcing cloth 36 is sewn are the peripheral portions of both the main body reinforcing cloth 36 and both main body cloth portions 34 and 35. It is connected by a main body peripheral sewn portion 38 provided along with many parts of the main body. The main body peripheral edge sewing portion 38 is formed by sewing both main body reinforcing cloths 36 and a portion of the peripheral edges of both main body cloth portions 34 and 35 except for the rear end portion (the portion near the folding line 33). There is.

Regarding the above sewing, in FIGS. 4 to 7 and 9, the sewn portion is represented by three line types. The same applies to FIGS. 10 and 11 showing a modified example. The first line type is a line (a type of broken line) in which thick lines of a certain length are arranged intermittently, and this shows a state in which the sewn portion is viewed from the side (main body in FIG. 4). Reinforcement sewing part 37, main body peripheral edge sewing part 38, etc.). The second line type is a line (a type of broken line) that is expressed by intermittently arranging thin lines of a certain length (longer than a general broken line). It shows the state of the sewing thread that is located in the back and cannot be seen (hidden) directly (see the inner reinforcing sewing section 59, the inner peripheral edge sewing section 61, the exhaust reinforcing sewing section 64, etc. in FIG. 4). The third line type is a line (a type of broken line) in which points are arranged at regular intervals to represent the state of the sewing thread between the main body cloth portions 34 and 35 to be sewn (a type of broken line). Refer to the main body peripheral edge sewing portion 38, the inner peripheral edge sewing portion 61, etc. in FIG. 5). That is, the figure in which sewing is represented by the third line type shows a cross-sectional structure along a cross section passing through the sewn portion.

As shown in FIGS. 4 and 5, the portion between the cloth portions 34 and 35 of both main bodies and surrounded by the main body peripheral sewn portion 38 constitutes the main body expansion portion 39 that expands and expands by the expansion gas. ing.

Exhaust holes 41 are formed in the front portions of the main body cloth portions 34 and 35 and the main body reinforcing cloth 36 to communicate the inside and the outside of the main body expansion portion 39. The exhaust hole 41 is for discharging excess expansion gas in the main body expansion portion 39 to the outside, and is also called a vent hole. The main body reinforcing cloth 36 and the main body cloth portions 34 and 35 are sewn by an annular exhaust reinforcing sewing portion 42 provided around the exhaust hole 41, respectively. Each exhaust hole 41 is reinforced by a main body reinforcing cloth 36 and an exhaust reinforcing sewing portion 42.

<Inner bag 50>
As shown in FIGS. 5, 7 and 8, the inner bag 50 expands and expands to inflate a specific part of the main body inflating portion 39 preferentially over other parts at the initial stage of unfolding. In this embodiment, it corresponds to the "expansion portion" in the claims. The inner bag 50 is arranged in the latter half of the main body expansion portion 39. A piece of cloth 51 made of the same material as the airbag body 31 is used for forming the inner bag 50. A fold line 52 extending in the vertical direction is set on the cloth piece 51. The cloth piece 51 is folded in half along the folding line 52 and overlapped in the vehicle width direction. Here, in order to distinguish the two overlapped portions of the inner bag 50, the one located inside the vehicle is referred to as the inner cloth portion 53, and the one located outside the vehicle is referred to as the inner cloth portion 54. In the present embodiment, these inner cloth parts 53 and 54 correspond to the cloth parts within the scope of claims.

The inner bag 50 is arranged so that the folding line 52 is overlapped on the folding line 33 in the airbag main body 31. The inner bag 50 is sewn to the airbag main body 31 by a joint sewing portion (not shown) provided on the double fold lines 33 and 52.

The inner bag 50 includes an upper expansion portion 55, a lower expansion portion 56, and an intermediate expansion portion 57. The upper expansion portion 55 expands and expands in front of the upper portion of the seat back 14 to protect the shoulder portion PS of the occupant P1 from the impact at the time of a side collision through the upper portion of the main body expansion portion 39. The lower expansion portion 56 expands and expands in front of the lower portion of the seat back 14 to protect the lumbar portion PP of the occupant P1 from the impact at the time of side collision through the lower portion of the main body expansion portion 39. The intermediate expansion portion 57 expands and expands in front of the intermediate portion in the vertical direction of the seat back 14, so that the intermediate expansion portion 57 extends from the shoulder PS to the lumbar PP of the occupant P1 through the rear portion of the intermediate portion in the vertical direction of the main body expansion portion 39. Protects the rear part of the site from the impact of a lateral collision.

Here, the protection target of the occupant P1 by the main body expansion portion 39 through the inner bag 50, that is, the shoulder PS, the lumbar PP, and the rear portion between them are all other parts, for example, FIGS. 1 and 2. It has higher impact resistance than the chest PT, abdominal PB, etc. shown in. The inner bag 50 supplies the expansion gas to the portion that expands on the side of the portion having high impact resistance with priority over the other portions, and raises the internal pressure at an early stage to increase the internal pressure at an early stage. Through 39, the upper body of the occupant P1 is effectively protected from the impact at the time of a side collision with an internal pressure corresponding to the impact resistance of the occupant P1.

As shown in FIGS. 5, 7 and 8, of the peripheral edges of the inner cloth portions 53 and 54, the portions other than the rear end portion (the portion near the folding line 52) are formed along the peripheral edge portion. The strip-shaped inner reinforcing cloth 58 is overlapped. The inner cloth portions 53 and 54 and the inner reinforcing cloth 58 are connected by an inner reinforcing sewing portion 59 provided along the inner reinforcing cloth 58. The inner reinforcing sewing portion 59 is formed by sewing both inner reinforcing cloths 58 and both inner reinforcing cloths 53 and 54. The peripheral edge of each of the inner cloth portions 53 and 54 is reinforced by the inner reinforcing cloth 58 and the inner reinforcing sewing portion 59.

Both inner cloth portions 53 and 54 to which the inner reinforcing cloth 58 is sewn as described above are provided along the both inner reinforcing cloths 58 and many parts of the peripheral edges of both inner reinforcing cloths 53 and 54. It is connected by the peripheral sewn portion 61. In the present embodiment, the inner peripheral sewn portion 61 corresponds to the peripheral sewn portion within the scope of claims. The inner peripheral edge sewing portion 61 is formed by sewing both inner reinforcing cloths 58 and a portion of the peripheral edges of both inner cloth portions 53 and 54 except for the rear end portion (the portion near the folding line 52). There is.

As shown in FIG. 5, each of the upper expansion portion 55, the lower expansion portion 56, and the intermediate expansion portion 57 is provided with an exhaust structure ES for expansion gas. These exhaust structure ESs have the same configuration as each other.

As shown in FIGS. 6 and 9, in each exhaust structure ES, the inner peripheral edge sewing portion 61 and the inner reinforcing sewing portion 59 are respectively released from suture in a part of the region. By releasing the suture, a pair of terminal portions 62 separated from each other are formed on the inner peripheral edge sewing portion 61. A part of the peripheral edge portion of each inner cloth portion 53, 54 and the corresponding portion in the inner reinforcing cloth 58 are surrounded by the inner peripheral edge sewing portion 61 from the outer peripheral edge thereof, passing between both terminal portions 62. A notch 63 that penetrates into the inside of the area is formed. The notch 63 for each inner cloth portion 53, 54 is opened at the outer peripheral edge of the inner cloth portion 53, 54 and has a semicircular shape. An exhaust hole (vent hole) for allowing the inside and the outside of the inner bag 50 to communicate with each other by the portion of both cut portions 63 inside the terminal portion 62 and discharging the expansion gas in the inner bag 50 to the outside. (Also called) 65 is configured.

Each inner cloth portion 53, 54 is provided with an exhaust reinforcement sewn portion 64 that reinforces a peripheral portion of the cut portion 63. The exhaust reinforcement sewing portion 64 for each of the inner cloth portions 53 and 54 has a linear shape and surrounds the notch portion 63. Further, in the present embodiment, the exhaust reinforcement sewing portion 64 for each of the inner cloth portions 53 and 54 is formed in an arc shape along the shape of the notch portion 63.

More specifically, a part of the inner reinforcing cloth 58 described above is also overlapped with the peripheral portion of the cut portion 63. The peripheral portion of the cut portion 63 in the inner cloth portions 53 and 54 and the peripheral portion of the cut portion 63 in the inner reinforcing cloth 58 are connected by an exhaust reinforcing sewing portion 64 provided along the cut portion 63. .. Here, "provided along the cut portion 63" means that the portion is provided at a position separated by a certain distance from the cut portion 63. Further, the exhaust reinforcement sewn portions 64 for each of the inner cloth portions 53 and 54 intersect (orthogonally) substantially at right angles to the inner peripheral sewn portion 61 at a portion opposite to the cut portion 63 with each terminal portion 62 sandwiched between them. ing.

<Expansion thickness regulation part 70>
As shown in FIGS. 5, 7 and 8, the expansion thickness regulating portion 70 is for regulating the thickness in the vehicle width direction (hereinafter referred to as “expansion thickness”) when the main body expansion portion 39 is expanded. .. The expansion thickness regulating portion 70 has a configuration similar to that generally called a tether, and is an intermediate portion in the vertical direction of the main body expansion portion 39, and is an intermediate portion in the front-rear direction, more specifically, an inner bag. It is located at a position slightly separated forward from the intermediate expansion portion 57 of 50. The expansion thickness regulating portion 70 includes a single piece of cloth made of the same material as the main body cloth portions 34 and 35. Both side portions of the cloth piece in the vehicle width direction are sewn to the corresponding ones of the main body cloth portions 34 and 35 by the elliptical joint sewing portion 71 extending in the vertical direction. The expansion thickness regulating portion 70 is bridged between the two main body cloth portions 34 and 35 slightly in front of the intermediate expansion portion 57 in the inner bag 50 by the above-mentioned stitching with the main body expansion portion 39 on both side portions.

When the main body expanding portion 39 expands and expands, the expansion thickness regulating portion 70 is in a state of being strained in the vehicle width direction, and regulates the thickness of the main body expanding portion 39 in the same direction. At this time, the distance between the two joint sewing portions 71 becomes the expansion thickness of the main body expansion portion 39 in the vicinity of the expansion thickness regulation portion 70.

In the expansion thickness regulating portion 70, a through hole 72 is formed in a portion of the intermediate expansion portion 57 in front of the exhaust hole 65. The through hole 72 allows the expansion gas discharged from the exhaust hole 65 to pass through the expansion thickness regulating portion 70. The circumference of the through hole 72 in the expansion thickness regulation portion 70 is reinforced by an annular reinforcing sewing portion 73 provided in the expansion thickness regulation portion 70.

Then, the entire gas generator 20 is tilted so that the gas ejection portion 21a is located at the upper end portion of the inflator 21 and is located at the rear side toward the upper portion, and is inside the rear end portion of the intermediate expansion portion 57. It has been inserted. The harness of the gas generator 20 is passed through the inner bag 50 and the airbag main body 31 and is pulled out to the outside of the airbag 30.

The plurality of bolts 23 in the gas generator 20 are inserted into the inner tube, the inner bag 50, and the airbag main body 31. By this insertion, the gas generator 20 is locked in a positioned state with respect to the airbag 30.

By the way, as shown in FIG. 3, the airbag module ABM having the gas generator 20 and the airbag 30 as main components is the gas generator 20 of the unexpanded non-expanded airbag 30 (see FIG. 4). By folding the front part and the like, it is made into a compact storage form. This is because the airbag 30 is suitable for storage with respect to the storage portion 15 having a limited size in the seat back 14. In FIG. 3, the members arranged in the airbag main body 31, for example, the inner bag 50, the expansion thickness regulating portion 70, and the like are not shown.

The airbag module ABM in the storage form is arranged in the storage unit 15. In the present embodiment, the airbag module ABM is arranged inside the vehicle from the seat frame 16, but may be arranged outside the vehicle. A bolt 23 extending from the gas generator 20 and inserted into the inner tube, the inner bag 50 and the airbag body 31 is inserted into the seat frame 16, and the nut 24 is tightened to the bolt 23. By this tightening, the gas generator 20 is attached to the seat frame 16 together with the inner tube, the inner bag 50, and the airbag main body 31 in an inclined state so as to be located on the rear side toward the upper part.

The gas generator 20 may be attached to the seat frame 16 by a member different from the bolt 23 and the nut 24 described above. Further, the inflator 21 may be directly attached to the seat frame 16 without using the retainer 22.

As shown in FIG. 1, the side airbag device includes an impact sensor 75 and a control device 76 in addition to the above-mentioned airbag module ABM. The impact sensor 75 is composed of an acceleration sensor or the like, and detects an impact applied to the vehicle 10 from the side through the side wall portion 11. The control device 76 controls the operation of the gas generator 20 based on the detection signal from the impact sensor 75.

Further, the vehicle 10 is equipped with a seatbelt device for restraining the occupant P1 seated on the vehicle seat 12 to the vehicle seat 12, but in FIGS. 1 and 2, the seatbelt device is provided. Is omitted.

Next, the operation of the present embodiment configured as described above will be described. In addition, the effects caused by the action will also be described.
When the impact sensor 75 does not detect that an impact has been applied to the side wall portion 11 from the side, the control device 76 does not output an operation signal for operating the gas generator 20, and the expansion gas is discharged. Not spouted. The airbag 30 in which the gas generator 20 is housed continues to be housed in the storage section 15 in a folded state.

When an impact of a predetermined value or more is applied to the side wall portion 11 from the side due to a side collision or the like while the vehicle 10 is traveling, and this is detected by the impact sensor 75, gas is emitted from the control device 76 based on the detection signal. The above operation signal is output to the generator 20. In response to this operation signal, expansion gas is ejected from the gas ejection portion 21a of the gas generator 20. The ejected expansion gas is first supplied to the inner tube surrounding the gas generator 20. This expansion gas is rectified by the inner tube and is supplied from the upper end open portion of the inner tube to the upper expansion portion 55 and from the lower end open portion to the lower expansion portion 56.

The upper expansion portion 55 and the lower expansion portion 56 start expansion due to the supply of the expansion gas, and the intermediate expansion portion 57 connected to them also starts expansion. When the inner bag 50 expands, the portion around the inner bag 50 in the main body expansion portion 39 is pushed by the inner bag 50 to start expansion.

The inner bag 50 and the main body expanding portion 39 expand while the folded state is resolved (deployed). Each expansion of the inner bag 50 and the main body expanding portion 39 is performed while expanding in the reverse order of the folded order.

A part of the expansion gas in the upper expansion portion 55 is discharged into the main body expansion portion 39 through the upper exhaust hole 65 provided in the upper expansion portion 55. A part of the expansion gas in the lower expansion portion 56 is discharged into the main body expansion portion 39 through the lower exhaust hole 65 provided in the lower expansion portion 56. A part of the expansion gas in the intermediate expansion portion 57 is discharged into the main body expansion portion 39 through the intermediate exhaust hole 65 provided in the intermediate expansion portion 57.

The main body expansion portion 39 is further expanded and expanded by these discharged expansion gases.
The inner bag 50 and the main body expanding portion 39 that expand and expand as described above come out of the seat back 14 with a part (a portion in the vicinity of the gas generator 20) left in the storage portion 15.

The inner bag 50 and the main body expansion portion 39 to which the expansion gas is continuously supplied are the side wall portion 11 and the occupant P1 seated on the vehicle seat 12 as shown by the alternate long and short dash line in FIGS. 1 and 2. Expands and expands forward with the upper body.

As shown in FIG. 8, the expansion thickness regulating portion 70 is pulled to both sides in the vehicle width direction as the main body expansion portion 39 expands and expands. When the expansion thickness regulating portion 70 is in a tense state, the expansion of the main body expanding portion 39 in the vehicle width direction is regulated.

Then, the upper body of the occupant P1 (the region from the lumbar portion PP to the shoulder portion PS) is pressed and restrained by the expanded and expanded main body expansion portion 39.
By the way, in each of the three exhaust structure ESs in the inner bag 50, the expansion gas is discharged as follows.

As each of the upper expansion portion 55, the lower expansion portion 56, and the intermediate expansion portion 57 expands, the pair of inner cloth portions 53, 54 are in the thickness direction of the inner cloth portions 53, 54, as shown in FIG. It is pulled to both sides in the vehicle width direction. Along with this, the notch 63 for each inner cloth 53, 54 is pulled in the same direction. When the inner bag 50 is inflated, the notch 63 for each of the inner cloth portions 53 and 54 is opened. The portion of both notches 63 inside the terminal portion 62 functions as an exhaust hole 65 that communicates the inside and the outside of the inner bag 50. The portion of the exhaust hole 65 inside the terminal portion 62 is opened to the same extent when the inner bag 50 is expanded, regardless of the degree of occupant restraint by the inner bag 50. The opening shape of the exhaust hole 65 hardly changes. Therefore, the expansion gas in the inner bag 50 is stably discharged to the main body expansion portion 39 outside the inner bag 50 through the exhaust holes 65 opened as described above. With the discharge of the expansion gas, the internal pressures of the upper expansion portion 55, the lower expansion portion 56, and the intermediate expansion portion 57 each decrease. Then, the impact applied to the occupant P1 is alleviated by the decrease in internal pressure of each of the expansion portions and the occupant restraint, and the upper body of the occupant P1 is protected from the impact.

Here, as described above, the impact resistance of the shoulder PS and the lumbar PP of the occupant P1 is higher than the impact resistance of the chest PT, the abdominal PB, and the like. Therefore, there is no problem even if the internal pressures of the upper expansion portion 55, the lower expansion portion 56 and the intermediate expansion portion 57 increase. Rather, the upper expansion portion 55 passes through the shoulder PS and the lower expansion portion 56 passes through the lumbar PP. The upper body will be pushed inside the vehicle, and the passenger P1 will be more properly restrained and protected from impact.

As the inner bag 50 expands, the pair of inner cloth portions 53 and 54 are pulled, so that the inner peripheral sewn portion 61 shown in FIGS. 6 and 9 may be frayed starting from the terminal portion 62. However, the inner peripheral edge sewn portion 61 is reinforced by the exhaust reinforcing sewn portion 64 that intersects the inner peripheral edge sewn portion 61 at a position opposite to the cut portion 63 with each terminal portion 62 interposed therebetween. Therefore, even if the inner peripheral edge sewing portion 61 is frayed, the fraying is received by the exhaust reinforcement sewing portion 64. By this receiving, the inner peripheral edge sewing portion 61 is suppressed from fraying toward the side away from the cut portion 63 than the exhaust reinforcing sewing portion 64, and the shape of the exhaust hole 65 is maintained.

Further, in the present embodiment, the inner cloth portions 53 and 54 are reinforced by the linear exhaust reinforcing sewing portion 64 provided so as to surround the cut portion 63. Therefore, even if the pair of inner cloth portions 53, 54 are pulled to both sides in the vehicle width direction due to the expansion of the inner bag 50, the inner cloth portions 53, 54 begin to tear starting from the notch 63. The tear is received by the exhaust reinforcement sewing portion 64. By this receiving, it is possible to prevent the inner cloth portions 53 and 54 from being torn to the side away from the cut portion 63 beyond the exhaust reinforcement sewing portion 64.

In particular, in the present embodiment, each inner cloth portion 53, 54 is reinforced by a linear exhaust reinforcing sewn portion 64 provided along the cut portion 63 at a position as far away from the cut portion 63. The distance from the notch 63 to the exhaust reinforcement sewn 64 is about the same at any part of the notch 63. Therefore, even if the inner cloth portions 53 and 54 start to tear starting from the cut portion 63, they can be stopped at a position as far away from the cut portion 63.

According to this embodiment, the following effects can be obtained in addition to the above.
-As described above, as the inner bag 50 expands, the pair of inner cloth portions 53, 54 are pulled to both sides in the vehicle width direction. Along with this, the notch 63 for each inner cloth 53, 54 is pulled in the same direction. At this time, if the cut portion 63 has an angular shape such as a rectangle, the stress generated by the tension may be concentrated on the corner portion. In this respect, in the present embodiment, since the cut portion 63 for each of the inner cloth portions 53 and 54 has a semicircular shape, it is possible to suppress the concentration of stress caused by pulling.

The above embodiment can also be implemented as a modified example in which the above is modified as follows. The above embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.

<About airbag 30>
The airbag main body 31 may be composed of a main body expanding portion 39 that expands substantially entirely as in the above embodiment, but a non-expanding portion that is not supplied with expansion gas and does not expand is partially included. It may have.

-As the airbag main body 31 (main body expansion portion 39), an airbag whose inside is partitioned into a plurality of rooms (expansion chambers) may be used.
-The portion of the upper body of the occupant P1 protected by the airbag body 31 may be changed to a portion different from that of the above embodiment. In this case, the shape and size of the airbag body 31 are changed to a shape and size that can protect the target portion of the upper body of the occupant P1.

The main body reinforcing cloth 36 that reinforces the peripheral edges of the main body cloth portions 34 and 35 in the airbag main body 31 may be omitted. In this case, the main body reinforcing sewn portion 37 may be provided or omitted, but the effect of reinforcing the peripheral edges of the main body cloth portions 34 and 35 can be obtained only by the main body reinforcing sewn portion 37.

Similarly, the inner reinforcing cloth 58 that reinforces the peripheral edges of the inner cloth portions 53 and 54 in the inner bag 50 may be omitted. In this case, the inner reinforcing sewn portion 59 may be provided or omitted, but the effect of reinforcing the peripheral edges of the inner cloth portions 53 and 54 can be obtained only by the inner reinforcing sewn portion 59.

Even if the inner reinforcing cloth 58 is omitted, the exhaust reinforcing sewing portion 64 is required. As shown in FIG. 10, the exhaust reinforcement sewn portion 64 in this case needs at least a portion that intersects the inner peripheral sewn portion 61 at a portion opposite to the cut portion 63 with each terminal portion 62 sandwiched between them. This is to prevent the inner peripheral edge sewing portion 61 from fraying. Therefore, as shown in FIG. 10, the exhaust reinforcement sewing portion 64 may be composed of only the portion intersecting the inner peripheral edge sewing portion 61. Further, the exhaust reinforcement sewn portion 64 may be formed so as to have a length intermediate between the length of FIG. 10 and the length of the embodiment shown in FIG. 6 and the like.

-The cut portion may be formed in a shape different from the semicircular shape, for example, a semi-elliptical shape.
As shown in FIG. 6, in the inner cloth portions 53 and 54 and the inner reinforcing cloth 58, in the region sandwiched between the cut portion 63, the exhaust reinforcing sewing portion 64, and the inner peripheral sewing portion 61, FIG. As shown by the alternate long and short dash line in, the corner portion may be excised.

<Applicable target>
-The exhaust structure of the airbag is such that in a vehicle in which the vehicle seat 12 is arranged in a direction different from the front of the vehicle, for example, in a posture in which the seat back 14 faces sideways, the side (vehicle) with respect to the vehicle seat 12. It can also be applied to a type of side airbag device that protects the occupant P1 from the impact when an impact is applied from the front-rear direction.

-In the above embodiment, the exhaust structure of the airbag is applied to the inner bag 50, but instead of or in addition to this, it may be applied to the main body expansion portion 39 of the airbag main body 31. FIG. 11 shows an example in which the exhaust structure of the airbag is applied to the main body expansion portion 39 of the airbag main body 31 in which the inner bag 50 is not provided inside.

In the main body expansion portion 39, the peripheral portions of the pair of main body cloth portions 34, 35 (not shown) of the main body cloth portions 34 and 35 stacked in the thickness direction are sewn together by the main body peripheral edge sewing portion 38. In this case, the main body peripheral sewn portion 38 is released from suture in a part of the region, so that a pair of terminal portions 62 separated from each other are formed in the main body peripheral sewn portion 38. A cut portion 63 is formed in a part of the peripheral edge portion of each of the main body cloth portions 34 and 35, passing between the two terminal portions 62 and entering the inside of the region surrounded by the main body peripheral edge sewing portion 38. The main body cloth portions 34 and 35 are provided with an exhaust reinforcement sewing portion 64 that reinforces the peripheral portion of the cut portion 63. The exhaust reinforcement sewn portions 64 for each of the main body cloth portions 34 and 35 intersect with the main body peripheral sewn portion 38 at a position opposite to the cut portion 63 with each terminal portion 62 interposed therebetween.

The main body cloth portions 34, 35, the main body peripheral sewn portion 38, and the main body expanding portion 39 in the above modification correspond to the cloth portion, the peripheral sewn portion, and the expanding portion, respectively, within the scope of the claims.
According to this modification, the expansion gas in the main body expansion portion 39 of the airbag main body 31 can be stably discharged.

An inner bag 50 similar to that of the above embodiment may be provided in the airbag main body 31 in the above modification. In that case, the exhaust structure of the airbag may or may not be applied to the inner bag 50 as in the above embodiment.

-The exhaust structure of the airbag is formed by suturing the peripheral edges of a pair of cloth portions stacked in the thickness direction at the peripheral sewn portion, and has an expanding portion that expands with the expanding gas. The condition is that it can be applied to an airbag device of a type different from the side airbag device.

In this case, the exhaust structure of the airbag can be applied not only to the front seats of the vehicle 10 but also to the airbag device installed in the rear seats. The vehicle 10 in this case includes not only private vehicles but also various industrial vehicles.

Further, the exhaust structure of the airbag can be applied to an airbag device mounted on a vehicle seat in a vehicle other than the vehicle 10, for example, an aircraft or a ship.
<Others>
The control device 76 may be changed to a specification that outputs an operation signal to the inflator 21 when it is predicted that an impact from the side will be applied to the side wall portion 11 of the vehicle 10.

30 ... Air bag, 34, 35 ... Main body cloth part (cloth part), 38 ... Main body peripheral sewn part (peripheral sewn part), 39 ... Main body expansion part (expansion part), 50 ... Inner bag (expansion part), 53, 54 ... Inner cloth part (cloth part), 61 ... Inner peripheral edge sewing part (peripheral sewing part), 62 ... Terminal part, 63 ... Notch part, 64 ... Exhaust reinforcement sewing part, ES ... Exhaust structure.

Claims (4)

An exhaust structure applied to an airbag formed by suturing the peripheral edges of a pair of cloth portions stacked in the thickness direction at a peripheral sewing portion and having an expanding portion that is expanded by an expansion gas.
By releasing the suture in a part of the peripheral sewn portion, a pair of terminal portions separated from each other is formed in the peripheral sewn portion.
A notch is formed in a part of the peripheral edge of each cloth portion so as to pass between both terminal portions and enter the inside of the area surrounded by the peripheral sewn portion.
Each cloth portion is provided with an exhaust reinforcement sewn portion that reinforces at least a part of the peripheral portion of the cut portion in the cloth portion.
The exhaust reinforcing sewn portion for each cloth portion has an exhaust structure of an airbag that intersects the peripheral sewn portion at a position opposite to the cut portion with each terminal portion sandwiched between them. The exhaust reinforcement sewn portion for each cloth portion has a linear shape and surrounds the notch portion.
The exhaust structure for an airbag according to claim 1, wherein the exhaust reinforcement sewn portion for each cloth portion intersects the peripheral sewn portion at both ends of the exhaust reinforcement sewn portion. The exhaust structure for an airbag according to claim 2, wherein the exhaust reinforcing sewn portion for each cloth portion is provided along the shape of the cut portion. The exhaust structure for an airbag according to any one of claims 1 to 3, wherein the cut portion of each cloth portion has a semicircular shape.

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