JPH11245751A - Air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of an air bag by dispensing with any turnover work after sewing operations. SOLUTION: A partitioned foundation cloth 23 is set up in space between both first and second foundation cloths 21 and 22 constituting a baggy air bag 1. These three foundation cloths 21, 22 and 23 are superposed on one another, and a terminal part A is turned up inward, sewing it up, and this baggy air bag 1 is manufactured. In this manufacturing process, it is unnessary to turn over both inner and outer surfaces of the air bag 1. after sewing, and thus operability is made so favorable enough, and further automation becomes capacitated. Owing to the partitioned foundation cloth 23, an inner part of the air bag 1 is partitioned into both first and second sub-chambers 31 and 32, and thus its unfolding characteristic is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag provided, for example, in a steering wheel of a vehicle, and swells due to inflow of gas to reduce the impact of a collision applied to an occupant.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 8-310325
As shown in the publication, the gas is supplied from an inflator to a bag-shaped airbag which is provided on a steering wheel of an automobile and is stored in a small folded state, and is inflated,
2. Description of the Related Art Airbag devices that reduce the impact of a collision applied to an occupant are used. The airbag used in the airbag device is formed by, for example, stacking two circular nylon woven base fabrics, and placing these base fabrics along the outer edge and inside from the outer edge. Sewn together leaving a surplus part of about 10 mm, that is, ears, and then inverted by pulling out the other base cloth from the circular hole formed in one base cloth,
The ear is positioned inside the bag to improve the appearance and the like, and is formed in a flat bag shape.

[0003] However, the above-mentioned conventional configuration has a problem in that inversion of the airbag is required after the suturing operation, which increases the number of steps and the manufacturing cost. That is, when a circular base fabric arranged in a flat shape and placed on a sewing machine table is sewn to sew the outer periphery, the shape of the airbag (work) does not collapse. The shape of the base fabric is large, and it takes time to adjust the shape. In addition, the outer periphery of each base fabric whose cross section is curved into a substantially J-shape due to inversion rises to self-restored, making it difficult to obtain a uniform shape, increasing the number of steps. And there is a problem that is an obstacle to automation.

[0004] For example, German Patent Application No. DE4
As shown in the specification of 142326A1, there is known a configuration in which a fractional base fabric for partitioning the inside of the bag is arranged between a pair of base fabrics forming the bag to improve the deployment performance. However, in such a configuration in which three or more base fabrics are sewn, there is a problem that reversing the bag becomes more difficult.

[0005]

As described above, in the conventional configuration, in the production of an airbag, a reversing operation is required after the suturing operation, which increases the number of steps, is difficult to automate, and reduces the production cost. Has the problem of rising. In particular, in a configuration in which three or more base fabrics are sewn, there is a problem that reversing the bag becomes more difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an airbag that does not require a reversing operation after a suturing operation in manufacturing, and can reduce manufacturing costs. .

[0007]

According to the first aspect of the present invention, there is provided an airbag comprising a first base cloth and a second base cloth superposed on the first base cloth.
And a joining portion where outer peripheral portions of the first and second base fabrics are joined to each other, and a fabric is located at an outer edge portion of the first and second base fabrics, and the fabric is folded back to form a shape at the joining portion. And a folded part that is held.

[0008] In this configuration, the outer peripheral portions of the first and second base fabrics are joined to each other at the joining portion to form a bag shape. Since the folded portion obtained by folding the fabric is located at the outer edge of the first and second base fabrics, the terminal portion obtained by cutting the first and second base fabrics has an outer periphery without inverting the airbag after the sewing. Does not protrude. Therefore, the operation of reversing the airbag is not required, and the shape of the airbag during manufacture is suppressed, and automation is facilitated, and the manufacturing cost can be reduced. Since the shape of the folded portion is maintained by the joining portion that joins the outer peripheral portions of the first and second base fabrics, the number of components does not increase, and the manufacturing process is not complicated.

According to a second aspect of the present invention, in the airbag according to the first aspect, the folded portion is formed by folding an outer peripheral portion of at least one of the base fabrics.

In this configuration, the structure is simplified and the manufacturing cost is reduced.

According to a third aspect of the present invention, in the airbag according to the first aspect, the folded portion covers the end portions of the first base cloth and the second base cloth, and is separate from the base cloth. It is formed using a protective cloth.

In this configuration, since the folded portion is formed using a protective cloth separate from the first base cloth and the second base cloth, the protective cloth has characteristics required as the base cloth. There is no need to meet, and the choice of materials is expanded.

According to a fourth aspect of the present invention, there is provided an airbag according to any one of the first to third aspects, further comprising a fraction base fabric for partitioning between the first base fabric and the second base fabric. It is.

[0014] In this configuration, by the fractionation base fabric,
The development characteristics can be easily improved. In addition, in the case where the separation base fabric is provided, the operation of inverting the airbag becomes difficult, but the operation of inverting the airbag is not required because the folded portion is provided, so that the manufacturing is facilitated.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an airbag according to the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 1 denotes an airbag. The airbag 1 constitutes an airbag device 2 partially shown in FIG. 1, and the airbag device 2 is a steering wheel of an automobile (not shown). Is mounted on the boss portion of the steering wheel body of the vehicle to protect an occupant, which is an object to be protected, from the impact of a collision. The steering wheel body is usually mounted on an inclined steering shaft and used in an inclined state. Hereinafter, the side on which the airbag device is attached will be referred to as the occupant side, the upper side, or the front side, and the occupant side. Will be described as the vehicle body side, the lower side, or the back side.

The airbag device 2 includes a base plate 11 constituting a support member, an airbag 1, an inflator 12, a retainer 14 constituting a support member, a cover body, and the like attached to the base plate 11. I have.

The base plate 11 is formed by pressing a metal plate or the like, and has a substantially rectangular planar portion.
11a and a peripheral plate portion 11b bent downward from the outer peripheral portion of the substrate portion are integrally formed. And the substrate part 11a
Has a circular hole-shaped inflator mounting hole formed substantially in the center thereof, and a plurality of bolt mounting holes, four in the present embodiment, located around the inflator mounting hole. Are formed. In addition, in the peripheral plate portion 11b,
An attachment piece is formed, and the attachment piece is attached to a core of the steering wheel body or the like.

The inflator 12 has a substantially cylindrical main body portion 12a. A flange portion 12b projects from an outer peripheral portion of the main body portion 12a.
Above b, a plurality of gas injection ports for injecting gas are radially arranged. Also, the flange portion 12b has
A bolt mounting hole communicating with the bolt mounting hole of the base plate 11 is formed.

The retainer 14 is formed integrally with an annular retainer body 14a and a cup-shaped bulging portion 14b bulging upward from the retainer body 14a. Mounting bolts inserted into the respective bolt mounting holes are fixed to the retainer body 14a downward. Further, the bulging portion 14b is formed with a through hole (not shown) through which gas is inserted, which is located at the outer peripheral portion, and is located at the center of the fixed plate portion which covers the upper side of the inflator 12, and A fixing portion 14c such as a fixing hole is formed. A fixing tool such as a fixing screw that constitutes a restricting means is screwed and fixed to the fixing portion 14c.

The cover body is integrally formed of a synthetic resin, and has a curved covering portion that covers a part of the boss portion and the rim portion of the steering wheel body, and protrudes downward from the lower surface of the covering portion. And a rectangular cylindrical mounting wall. The portion surrounded by the lower side of the covering portion and the inside of the mounting wall portion is a storage space for the airbag 1 and faces the storage space, and has a substantially H-shaped flat surface on the lower surface of the covering portion. A vulnerable tear line is formed in a shape. Also, the mounting wall portion is a peripheral plate portion 11b of the base plate 11.
And is fixed by using a plurality of rivets.

The airbag 1 is a circular cloth, which is a first base cloth (upper base cloth, front panel) 21 and a second base cloth (lower base cloth, back panel) which are arranged vertically. )twenty two
And a circular separating base cloth (intermediate base cloth, center panel) 23 disposed between the base cloths 21 and 22.
The three base cloths 21, 22, and 23 are folded in the direction toward the inside while the outer peripheral end portions A are overlapped with each other, and along the folded outer peripheral edge and at the edge portion. Six pieces of cloth are integrally sewn together at a sewn portion (stitch line) 25 as a joining portion using a sewing thread at a position separated by a predetermined dimension from, and a folded portion 26 is formed on the outer peripheral portion.
In addition, it is preferable that the terminal portion A of each of the base fabrics 21, 22, and 23 is folded back toward the second base fabric 22. Then, in this state, the first
A flat bag-shaped outer shell is formed by the base cloth 21 and the second base cloth 22, and the inside of the outer shell is formed by the fraction base cloth 23 into the first compartment 31 and the first compartment 31. And a second sub-chamber 32 located above the sub-chamber 31.

The lower second fabric 22 has a gas inlet 35 which is an inflator opening serving as a gas inlet and is formed at the center thereof. Around the inlet 35, a bolt mounting hole 36 is formed.

Further, a plurality of communication ports (first vent holes) 41 as gas communication sections are formed in the fractionation base fabric 23 near the outer peripheral portion. And these communication ports 41
Have a substantially elliptical shape and are arranged at substantially equal intervals in a so-called radial manner. In the center of the fractionation base fabric 23,
A fixed portion such as a fixing hole into which a hole is inserted is formed.

Further, the dividing base cloth 23 and the second base cloth 22 are formed with circular holes which are located on the center side of the communication port 41 and communicate with each other. A substantially airtight sewing is performed along the suture line 44, and an exhaust port (second vent hole) 45 as a gas exhaust portion is formed at one or a plurality of locations. That is, the exhaust port 45 is
The second compartment 32 is not communicated with the second compartment 32, but is communicated only with the second compartment 32.

At the time of manufacturing the airbag 1, first, a conventional nylon fiber cloth is cut into a circular shape using a racer cutter or the like, and necessary holes are formed. Cloth 21, second base cloth 22, and fraction base cloth
Form 23. Next, as shown in FIG. 3, the three base cloths 21, 22, and 23 are stacked and placed on a manufacturing apparatus having a folding jig 51 and an electric sewing machine 52. And base cloth 21,
An arbitrary point on the outer periphery of 22 or 23 is folded back to make a folding jig 51
When the manufacturing apparatus is operated by setting the sewing machine 54 in the circumferential direction, the sewing machine 54 automatically urges the sewing machine 54 in the circumferential direction.
23 are sewn together to form a sewn portion 25 and a folded portion 26 is formed.

When assembling the airbag device 2, the retainer 14 is provided inside the first compartment 31 of the airbag 1.
And the mounting bolts are inserted into the bolt mounting holes of the airbag 1 and the base plate 11, and
The fixing tool 16 inserted from above into the fixed portion 43 of the retainer 14
Of the fraction base fabric 23 and the retainer 14
Fixed to. Then, the airbag 1 is folded into a predetermined shape, fitted with a cover from above. Further, the upper part of the inflator 12 is inserted into the first compartment 31 of the airbag 1 from below through the inflator mounting hole of the base plate 11 and the gas inlet 35 of the airbag 1, and the mounting bolt is attached to the flange. Insert it into the bolt mounting hole of the part 12b and tighten with a nut from below. In this state,
The airbag 1 and the base plate 11 are fastened together between the retainer 14 and the inflator 12, and the airbag device 2 is assembled.

When a collision impact is applied to the vehicle equipped with the airbag device 2, the control unit (not shown) activates the inflator 12 and rapidly inactivates the airbag 1 from the gas injection port of the inflator 12. Gas is injected. Then, the airbag 1 breaks and bulges the cover body along the tear line, bulges in a predetermined shape in front of the occupant, receives and restrains the occupant thrown forward, and suppresses the impact applied to the occupant. It is designed to ease. Further, the operation when the airbag 1 is inflated will be described in detail. First, the gas injected from the inflator 12 is introduced directly into the first compartment 31 of the airbag 1 in the radial direction. You. And, the central part of the fractionation base fabric 23,
Since the first compartment 31 is fixed to the retainer 14, the first compartment 31 expands outward in an extremely flat shape. Then, after that, the gas flows into the second compartment 32 located on the occupant side from the communication port 41 formed in the outer peripheral portion, inflates the second compartment 32 from the outer peripheral portion, and the entire airbag 1 is inflated. Swell into a predetermined shape. Then, when the occupant collides with the airbag 1 or the like, the gas is discharged through the exhaust port 45 communicating with the second compartment 32, and the impact of the occupant is absorbed.

As described above, according to the present embodiment, since the folded portion 26 formed by folding the cloth into a substantially J-shaped cross section is formed on the outer edge of the airbag 1, the sewing of the base cloths 21, 22, and 23 is performed. Even if the inner and outer surfaces of the airbag 1 are not turned over later,
The terminal part A that cuts 1, 22, 23 does not protrude to the outer periphery,
Appearance and beauty can be improved. Therefore, the reversing work of the airbag 1 can be omitted, and the shape of the inverted airbag 1 due to the self-restoring reaction force during manufacturing can be suppressed. Therefore, the handling of the airbag 1 is easy even in the next step of folding the airbag 1 by a manual operation using a jig or an automatic folding such as a so-called petal folding in which the folding is performed around the inflator 12. , The workability is improved, the processes (processes) are smoothly connected, the automation is facilitated, and the manufacturing cost can be reduced.

The folded portion 26 is formed by folding the outer peripheral portions of the base fabrics 21, 22, and 23 themselves, and a sewing thread 54 for sewing the base fabrics 21, 22, and 23 into a bag shape. Since the shape can be held by the used sewing portion 25, the number of components does not increase, the manufacturing process can be prevented from being complicated, the structure can be simplified, and the manufacturing cost can be reduced.

Further, since a fractional base cloth 23 for partitioning between the first base cloth 21 and the second base cloth 22 is provided inside the airbag 1, the airbag 1 It is possible to easily control the distance and the pressure or the maintenance time of the bulging shape, for example, when the bulge 1 projects toward the occupant or the like to be protected.
The deployment characteristics can be easily improved. That is, the communication port 41 is formed in the vicinity of the outer peripheral portion of the separation base cloth 23 to clearly provide a gas flow path, and the center of the separation base cloth 23 is fixed to the retainer 14. First, the first compartment 31 located on the vehicle body side is quickly deployed in the outer peripheral direction, and then the second compartment 32 located on the occupant side is bulged from the outer peripheral side toward the center side. The deployment of the central portion where the load is most likely to be applied to the occupant's chest is delayed, so that the protrusion toward the occupant and the pressure toward the occupant can be suppressed. Therefore,
For example, even when the occupant operates the airbag device 2 in a state where the occupant takes an extreme forward leaning posture such that the chest contacts the steering wheel, the pressure on the chest can be reduced. Further, the gas injected from the inflator 12 causes the first compartment 31 to bulge, and then the second compartment 32 bulges and is exhausted from the exhaust port 45. In addition, high shock absorption characteristics can be stably realized. In addition, due to the synergistic effect of such a long gas flow path and a configuration in which the exhaust port 45 is depressed inside the second base cloth 22, heat discharged to the outside of the airbag 1 is suppressed. be able to.

Further, in the case of a three-layer structure provided with the separating base cloth 23, the reversing work of the airbag 1 becomes difficult. In particular, in a configuration in which the positions of the communication port 41 and the exhaust port 45 are shifted, mass production is not possible. Although the reversing work in the process is practically impossible, it is not necessary to perform the work of reversing the airbag 1 because the folded portion 26 is provided,
It can be easily manufactured.

The folded portion 26 has three base cloths 21, 22, 23.
The outer peripheral portions are collectively folded downward, but the folded portion 26 can have various structures.

For example, as shown in FIG. 4, first, the second base cloth 22 and the separation base cloth 23 are folded down and sewn together.
Further, the first base cloth 21 can be folded upward and stitched to form the folded portion 26.

As shown in FIG. 5, first, the first base cloth 21 and the separating base cloth 23 are folded down and sewn, and then the second base cloth 22 is folded up and sewn. The folded portion 26 can be formed.

As shown in FIG. 6, a small-diameter first compartment 31 is formed by sewing on the inner peripheral portion of the second base cloth 22, and the first base cloth 21 and the second base cloth 22 are joined together. Can be folded and sewn together to form a folded portion 26.

Further, the fraction base fabric 23 is not limited to one sheet,
As a multi-layer airbag 1 having two or more fractionation base fabrics 23, the flow of gas may be controlled more finely, or, for example, in the structure shown in FIG. It is also possible to adopt a configuration in which the separation base cloth 23 is not provided.

In addition to fixing the fraction base fabric 23 to the retainer 14, it can also be fixed to an inflator or base plate which is a member fixedly provided on the airbag device or the steering wheel body side. Fractionated base cloth 23
In addition to fixing the central portion, the eccentric position can be fixed to control the deployment direction.

In the above embodiment, the base cloths 21 and 2
2 and 23 are the same size and the outer peripheral portion is turned back, and a total of six base cloths 21, 22 and 23 are sewn together by sewing thread 54 so that, for example, the first base cloth 21 is The size of the base cloth of the embodiment is kept as it is, and the three base cloths 21, 22, and 23 are concentrically formed by setting the base cloths 22 and 23 to an outer diameter slightly larger than the diameter of a stitch line as a stitched portion. Pile, base cloth 22, 23
May be covered with a folded portion 26 of the first base cloth 21, and the four layers of base cloths 21, 22, and 23 may be sewn so as to penetrate with the sewing thread 54.

Further, in the above embodiment, the turning portion 26
Is formed by folding back each base cloth 21,22,23,
The folded portion 26 can be formed using a protective cloth which is a separate cloth from the base cloths 21, 22, 23.

For example, as shown in FIGS. 7 and 8, a protective cloth 55, which is a long ribbon-shaped (band-shaped) cloth, is supplied from a large-diameter roll, and laser-cut base cloths 21, 22, and 23 are provided. Folding jig 51 so as to cover terminal portion A from above and below.
The main sewing can be performed with the sewing needle of the electric sewing machine 52 in a state where the main sewing machine is deformed into a letter shape. In this configuration, the protective cloth 55
Only needs to cover the end portions A of the base cloths 21, 22, and 23, and the airbag 1 is not directly exposed to the internal pressure when the airbag 1 is deployed or a high-temperature inert gas. Therefore, the air permeability may be greater than those of the base fabrics 21, 22, and 23 constituting the bag of the airbag 1, that is, the airbag body, and characteristic values such as tensile strength and heat-resistant temperature may be low. It doesn't matter. As described above, the protective cloth 55 does not need to satisfy the characteristics required as the base cloth, and can broaden a selection range of materials.
For example, it is possible to reduce the manufacturing cost by using a ribbon that is less expensive than a normal airbag fabric. In addition, various colors of ribbons can be used as a color code to display, for example, the internal volume of the airbag 1 and the like. Furthermore, it is possible to automatically supply and sew a long ribbon-shaped cloth, thereby improving mass productivity.

The airbag device is used not only for a driver attached to the steering wheel body, but also for a passenger in a passenger seat provided on an instrument panel, for protecting a side portion provided on a side portion of a seat, or for a rear portion of a seat. The present invention can be widely applied to an airbag of an airbag device for a rear seat provided in a vehicle, and further to an airbag of an airbag device that absorbs an impact of an object to be protected.

[0043]

According to the first aspect of the present invention, since the folded portion obtained by folding the cloth is located at the outer edge of the first and second base cloths, the airbag does not need to be turned over after sewing. The terminal portion obtained by cutting the first and second base fabrics does not protrude to the outer periphery. Therefore, the operation of reversing the airbag can be made unnecessary, and the shape of the airbag during manufacture can be suppressed, and automation can be facilitated, and the manufacturing cost can be reduced. Since the shape of the folded portion can be maintained by the joining portion that joins the outer peripheral portions of the first and second base fabrics, the number of components does not increase and the manufacturing process can be prevented from being complicated.

According to the airbag of the second aspect, in addition to the effect of the first aspect, the folded portion is formed by folding the outer peripheral portion of at least one of the base fabrics, so that the structure can be simplified and the manufacturing can be simplified. Cost can be reduced.

According to the airbag of the third aspect, in addition to the effect of the first aspect, the folded portion is formed using a protective cloth separate from the first base cloth and the second base cloth. Thereby, the protective cloth does not need to satisfy the characteristics required as the base cloth, and the material selection range can be expanded.

According to the airbag of the fourth aspect, in addition to the effects of any one of the first to third aspects, the airbag further comprises a fractionation base cloth for partitioning between the first base cloth and the second base cloth. Therefore, with this fractionation base cloth, the distance that the airbag projects toward the object to be protected and the pressure, the maintenance time of the expanded shape, and the like can be easily controlled, and the deployment characteristics can be easily improved. In addition, in the case where the separation base cloth is provided, the operation of inverting the airbag becomes difficult.

[Brief description of the drawings]

FIG. 1 shows an embodiment of an airbag of the present invention.
FIG. 3 is a cross-sectional view of a swelling state at a position II of FIG.

FIG. 2 is a bottom view of the airbag.

FIG. 3 is an explanatory view showing a manufacturing process of the airbag.

FIG. 4 is a cross-sectional view of an airbag according to another embodiment of the present invention in an inflated state.

FIG. 5 is a cross-sectional view of a further expanded embodiment of an airbag according to the present invention in an expanded state.

FIG. 6 is a cross-sectional view of a further expanded embodiment of the airbag of the present invention in an inflated state.

FIG. 7 is a cross-sectional view of an airbag according to still another embodiment of the present invention in an expanded state.

FIG. 8 is an explanatory view showing a manufacturing process of the airbag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Airbag 21 1st base cloth 22 2nd base cloth 23 Fractionated base cloth 25 Sewing part as a joint part 26 Folding part 55 Protective cloth A Terminal part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuhiro Kaneko 218 Aoshima-cho, Fuji-shi, Shizuoka Pref.

Claims (4)

[Claims] A first base cloth, a second base cloth to be superimposed on the first base cloth, a joining portion in which outer peripheral portions of the first and second base cloths are joined to each other, An airbag, comprising: a folded portion which is located at an outer edge portion of the first and second base fabrics, the folded portion being formed by folding the fabric and maintaining the shape at the joint portion. 2. The airbag according to claim 1, wherein the folded portion is formed by folding an outer peripheral portion of at least one of the base fabrics. 3. The folded portion is formed using a protective cloth separate from the base cloth, which covers the end portions of the first base cloth and the second base cloth. The described airbag. 4. The apparatus according to claim 1, further comprising a separating base cloth for partitioning between the first base cloth and the second base cloth.
The airbag according to any of the above.