JPH0622115U - Airbag device bag - Google Patents

Abstract

(57) [Abstract] [Purpose] An air bag that has a simple structure and is capable of satisfying both a swelling speed performance of swelling in a short time and a collision energy absorbing performance of reliably absorbing collision energy after swelling. Get the bag of the device. [Structure] A strap 34 is sewn inside the bag body 20 composed of an upper cloth 22 and a lower cloth 24. Strap 3
The intermediate portion of 4 is partially overlapped and sewn, and pressure absorbing portions 70, 72 and 74 are provided. Therefore,
At the initial stage of the swelling of the bag body 20, the volume of the bag body 20 is apparently small and the swelling time is shortened. When the internal pressure rises due to the collision of the occupant, the pressure absorbing parts 70, 72 and 74 are broken and spread, The volume of the body 20 is substantially increased to suppress the rapid increase in the internal pressure, and the collision energy is smoothly absorbed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bag body of an airbag device that is used in an airbag device that operates when a predetermined load is applied and that bulges toward a side of an occupant when the airbag device operates.

[0002]

[Prior art]

 In an air bag device, for example, an air bag device installed in a vehicle door, a predetermined load is applied to the vehicle door from the outside to direct the bag toward the side of the occupant seated on the seat. Inflate. As a result, the occupant is protected from the impact when such a load is applied.

Here, a vent hole is provided in the bag body used in the airbag device as described above. The vent hole is formed on the surface of the bag body on the side opposite to the occupant with a constant diameter, and the gas inside the bag body can be discharged. That is, when the vehicle suddenly decelerates, the bag body swells due to the gas generated from the inflator, and the occupant contacts the bag body, but at this time, the gas flows out from the vent hole, so that the internal pressure of the bag body suddenly increases. As a result, the collision energy of the occupant can be smoothly absorbed and the occupant can be reliably received by the bag.

[0004]

[Problems to be solved by the device]

 By the way, in such a bag body, it is necessary to bulge in a very short time by the gas from the inflator when the vehicle is rapidly decelerated, and it is necessary to surely absorb the collision energy after the bulge.

In this case, if the vent hole is formed small by focusing only on the swelling speed (time) of the bag, the outflow amount of gas when an occupant contacts the bag is reduced. The internal pressure of the bag rises excessively, which may prevent the collision energy of the occupant from being smoothly absorbed. On the other hand, if the vent holes were made large only by focusing on the collision energy absorption performance, The swelling time (speed) of swells significantly, and the original function cannot be exerted. As described above, in the bag body used in the airbag device, the bulging speed performance and the collision energy absorbing performance are tradeoffs to each other, and a bag body satisfying both of these performances has been desired.

In consideration of the above facts, the present invention has a simple structure that satisfies both the swelling speed performance of bulging in a short time and the collision energy absorbing performance of reliably absorbing the collision energy after swelling. An object is to obtain a bag body of an airbag device that can be used.

[0007]

[Means for Solving the Problems]

 The bag body of the airbag device according to the present invention is used in an airbag device that operates when a predetermined load is applied, and is formed into a bag shape by sewing an upper cloth and a lower cloth, and the upper cloth and the lower cloth are In the bag body of the airbag device, which is provided with a strap for alternately connecting the upper cloth and the lower cloth and swelled toward the side of the occupant by the gas generated from the inflator when the predetermined load is applied, The intermediate portion of the strap is partially overlapped, and the overlapped portion is sewn with a sewing strength equal to or lower than the sewing strength between the upper cloth and the lower cloth to provide a pressure absorbing portion.

[0008]

[Action]

 In the bag body of the airbag device having the above structure, when the airbag device is activated, the gas generated from the inflator swells to protect the occupant.

Here, since the middle portion of the strap is partially overlapped and sewn and the pressure absorbing portion is provided on the bag body, the volume of the bag body can be seen in the initial state of bulging of the bag body. It ’s small. Therefore, the gas generated from the inflator expands in a short time. When the occupant abuts and the internal pressure rises after the bag swells, the pressure absorbing part is sewn with a sewing strength that is less than the sewing strength between the upper cloth and the lower cloth, so the sewn portion increases as the internal pressure of the bag increases. Rupture, which causes the overlapping portion of the strap to expand and substantially increase the volume of the bag. For this reason, a rapid increase in the internal pressure of the bag body is suppressed, whereby the collision energy of the occupant is smoothly absorbed and the occupant is reliably received by the bag body.

As described above, in the bag body according to the present invention, since the volume is apparently small in the initial stage of the bag body bulge, the bag body bulges in a short time, and the volume substantially increases after the bag body bulge. The rise in internal pressure can be absorbed, and the simple structure can satisfy both the swelling speed performance of bulging in a short time and the collision energy absorbing performance of reliably absorbing the collision energy after swelling. it can.

[0011]

【Example】

 FIG. 4 shows a schematic overall configuration of an airbag device 10 to which a bag body 20 according to an embodiment of the present invention is applied.

The airbag device 10 is arranged between the outer panel and the inner panel of the door 12 on the driver's seat side of the vehicle, and, for example, when a predetermined load is applied along the direction of arrow A in FIG. In addition, a sensor (not shown) is provided to detect that a predetermined load is applied to the door 12 from the outside due to the deformation of the outer panel at that time. The airbag device 10 also includes an inflator 14, as shown in FIGS. The inflator 14 is filled with a gas generating agent (not shown) that is energized when the sensor is turned on to generate gas by heat. Therefore, when a predetermined load acts on the outer panel of the door 12, the sensor senses this and the gas generating agent burns, and a large amount of gas is generated from the inflator 14.

A bag body 20 is folded and accommodated at a position on the vehicle interior side of the inflator 14. Here, FIGS. 1 to 3 show an initial state in which the bag body 20 is bulged toward the side of the occupant 18 who is seated on the seat 16, and the following will be referred to with reference to the initial bulging state. The structure of the bag body 20 will be described.

The bag body 20 is configured by stitching two base cloths at a predetermined position. That is, the bag body 20 is provided with the upper cloth 22 and the lower cloth 24 outside the passenger compartment, which are each cut into a rectangular shape, on the inside of the passenger compartment (that is, on the side of the occupant 18) and on the outside of the passenger compartment. The outer peripheral edge portions of 24 are folded back inward and are sewn together by a suture thread 26. In this case, for example, the suture thread 26 is a 1260 denier thread, and the strength of the sewn portion is 30 kg · f / cm.

A mounting hole 28 corresponding to the inflator 14 is formed in the lower cloth 24. The peripheral edge of the mounting hole 28 is clamped by a ring plate 30 in a state where the inflator 14 is inserted in the mounting hole 28. The lower cloth 24 is fixed to the inflator 14.

A gas vent hole 32 is formed near the end of the upper cloth 22 in the width direction (direction of arrow X in FIG. 1).

On the other hand, a strap 34 is sewn inside the bag body 20. The strap 34 is formed to have a width dimension slightly shorter than the width dimension along the longitudinal direction of the upper cloth 22 and the lower cloth 24 (Y direction in FIG. 1), and the upper cloth 22 and the lower cloth 24 are sewn alternately. Has been done.

That is, one end of the strap 34 is sewn to the lower cloth 24 near the inflator 14 with a suture thread 36, and the longitudinal middle portion of the strap 34 is sewn to the upper cloth 22 with a suture thread 38. It is folded back and sewn to the lower cloth 24 with the suture thread 40, and again, the longitudinal middle portion of the strap 34 is folded back, and the other end is sewn to the upper cloth 22 again with the suture thread 42. The inside of the bag body 20 is divided into four expansion chambers 46, 48, 50, 52 along the width direction by the strap 34.

Further, the strap 34 is formed with communication holes 56, 58 and 60. For this reason, the expansion chambers 46, 48, 50, 52 are not only communicated by the outer ends of the strap 34 in the width direction (a gap between the upper cloth 22 and the lower cloth 24), but also the communication holes 56 of these. , 58, 60 also communicate with each other.

Further, the strap 34 is provided with pressure absorbing portions 70, 72, 74 at portions near upper portions of the communication holes 56, 58, 60, respectively. Each of the pressure absorbing parts 70, 72, 74 partially overlaps the intermediate part of the strap 34, and the overlapping part is sewn with sutures 76, 78, 80. In this case, for example, each suture thread 76, 78, 80 is a 420-denier thread, and the strength of the sewn portion is 10 kgf / cm. That is, each of the pressure absorbing portions 70, 72, 74 has a sewing strength equal to or lower than the sewing strength of the outer peripheral edge sewing portion of the upper cloth 22 and the lower cloth 24.

Next, the operation of this embodiment will be described. The bag body 20 having the above-described configuration is normally stored (when the airbag device 10 is inactive) in a folded state between the outer panel and the inner panel of the door 12.

From this state, when a predetermined load acts on the door 12 along the direction of arrow A in FIG. 4, the sensor is turned on by, for example, deforming the outer panel. As a result, the gas generating agent in the inflator 14 burns and ejects a large amount of gas into the expansion chamber 48 of the bag body 20. The expansion chamber 48 communicates with the expansion chambers 46, 50, and 52 through both ends of the strap 34 in the width direction and through the communication holes 56, 58, and 60, so that the gas ejected into the expansion chamber 48 is instantaneous. Also flow into the expansion chambers 46, 50, 52, whereby the bag body 20 is inflated toward the side of the occupant 18 while opening the airbag door, which is also a part of the door trim (not shown). As a result, the side portion of the occupant 18 is brought into contact with the bag body 20 in the bulged state, the collision energy of the occupant 18 is absorbed while the gas flows out from the gas vent 32, and the load on the occupant 18 is reduced. The occupant 18 is protected.

Here, since the bag body 20 is provided with the pressure absorbing portions 70, 72 and 74 by partially overlapping and sewing the intermediate portion of the strap 34, the bag body 20 is in an initial bulging state in the initial state. As shown in FIG. 2, the upper cloth 22 and the lower cloth 24 are connected by the straps 34 to be thin in the thickness direction, and the bag 20 has an apparently small volume. Therefore, the bag body 20 is inflated in a short time by the gas generated from the inflator 14. When the occupant 18 comes into contact with the bag body 20 after the bag 20 bulges and the internal pressure rises, the pressure absorbing parts 70, 72, 74 are sewn with a sewing strength equal to or lower than the sewing strength of the outer peripheral edge sewing parts of the upper cloth 22 and the lower cloth 24. As a result, the sutures 76, 78, 80 are broken as the internal pressure of the bag body 20 rises, and as a result, the pressure absorbing portions 70, 72, 74 (overlapping parts) of the strap 34 are sacked as shown in FIG. The body 20 expands in the thickness direction and the volume of the bag 20 substantially increases. For this reason, the sudden increase in the internal pressure of the bag body 20 is suppressed, the collision energy of the occupant 18 is smoothly absorbed, and the occupant 18 is reliably received by the bag body 20.

As described above, in the bag body 20 according to this embodiment, since the pressure absorbing portions 70, 72, 74 are provided on the strap 34, the volume of the bag body 20 is apparently small at the initial stage of bulging. Therefore, it swells in a short time, and after the swelling, the volume thereof substantially increases and the increase in internal pressure can be absorbed. Therefore, in order to increase the swelling speed (time) of the bag body 20, there is no need to reduce the size of the gas vent hole 32 to sacrifice the collision energy absorption performance, and to improve the collision energy absorption performance. There is no need to sacrifice the swelling speed performance of the bag body 20 by enlarging the gas vent hole 32. That is, with a simple structure, it is possible to satisfy both the swelling speed performance of bulging in a short time and the collision energy absorbing performance of reliably absorbing the collision energy after swelling.

Further, in the bag body 20, since the pressure absorbing portions 70, 72, 74 are provided on the strap 34, in other words, other special vent holes and the like are formed in the upper cloth 22 and the lower cloth 24. Therefore, the strength of the bag body 20 can be ensured without lowering the substantial strength of the upper cloth 22 and the lower cloth 24.

In this embodiment, the three pressure absorbing portions 70, 72, 74 are provided in the middle portion of the strap 34 corresponding to the communication holes 56, 58, 60, but the present invention is not limited to this. The pressure absorber can be increased or decreased as desired. Further, the strength of each pressure absorbing portion 70, 72, 74 (in other words, the sutures 76, 78, 80 for forming the same) is not limited to that of this embodiment, and the upper cloth 22 and the lower cloth Needless to say, the sewing strength can be appropriately changed as long as the sewing strength is equal to or lower than the sewing strength of the outer peripheral edge sewing portion of the cloth 24.

[0027]

[Effect of device]

 As described above, the bag body of the airbag device according to the present invention has a simple structure and has a swelling speed performance that swells in a short time and a collision energy absorbing performance that reliably absorbs collision energy after swelling. It has an excellent effect that both can be satisfied.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a bag body according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a bag according to an embodiment.

FIG. 3 is a cross-sectional view showing a state in which the pressure absorbing portion of the bag body according to the embodiment is expanded.

FIG. 4 is a schematic overall configuration diagram of an airbag device to which a bag body is applied.

[Explanation of symbols]

 10 Airbag Device 14 Inflator 20 Bag Body 22 Upper Cloth 24 Lower Cloth 34 Strap 70 Pressure Absorption Part 72 Pressure Absorption Part 74 Pressure Absorption Part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuyoshi Ohno 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Tomoyuki Fukatsu 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Takuya Otsuka 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. An air bag device which operates when a predetermined load is applied, and is formed into a bag shape by sewing an upper cloth and a lower cloth, and is sewn alternately to the upper cloth and the lower cloth, In the bag body of the airbag device, which has a strap connecting the upper cloth and the lower cloth and bulges toward the side of the occupant by the gas generated from the inflator when the predetermined load is applied, the middle portion of the strap is partially A bag body of an air bag device, wherein the pressure absorbing portion is provided by sewn the overlapped portion with a sewing strength of the upper cloth and the lower cloth that is lower than the sewing strength.