JP6922698B2 - Heat-resistant reinforcing cloth for airbags - Google Patents

Description

The present invention relates to a heat-resistant reinforcing cloth for an airbag that reinforces the heat resistance of an airbag that is deployed and expanded by an expansion gas ejected from an inflator.

An airbag device is effective as a device that protects an occupant from the impact when an impact is applied to the vehicle due to a collision or the like. This airbag device generally includes an inflator that ejects an expansion gas from a gas ejection portion, and an airbag that is deployed and expanded by the expansion gas.

In such an airbag device, a high-pressure expansion gas having a temperature of 500 ° C. or higher is ejected from the gas ejection portion. On the other hand, the main body cloth portion constituting the outer shell portion of the airbag is generally formed by using polyamide fiber or polyester fiber. The melting points of polyamide and polyester are around 250 ° C. When the heat of the high-temperature expansion gas is transferred, the cloth portion of the main body is instantaneously carbonized, and the carbonized portion is scattered by the pressure of the expansion gas to form holes. One of the countermeasures against this is to stack a plurality of reinforcing cloths made of the same material as the main body cloth on the inner surface of the main body cloth, which is easily affected by the heat of the expansion gas. According to this measure, the expansion gas is received by a plurality of reinforcing cloths, the heat of the expansion gas is less likely to reach the main body cloth portion, and the holes in the main body cloth portion can be suppressed.

However, as the number of reinforcing cloths increases, it becomes difficult to sew those reinforcing cloths to the main body cloth portion. Further, as the number of reinforcing cloths increases, not only the airbag becomes difficult to fold, but also the weight increases, and the bulk when folded becomes large, which causes a problem that the mountability is lowered.

Therefore, a heat-resistant reinforcing cloth in which a heat-resistant layer made of aluminum foil is laminated on a base cloth has been proposed (see, for example, Patent Document 1 and Patent Document 2). The heat-resistant layer is described as a "coating layer" in Patent Document 1, and is described as a "heat-resistant coating layer" in Patent Document 2. Further, the base cloth is described as "cloth" in Patent Document 1 and Patent Document 2.

Japanese Unexamined Patent Publication No. 3-287433 Japanese Unexamined Patent Publication No. 7-277121

The heat-resistant layer made of the aluminum foil has a melting point (around 650 ° C.) higher than the temperature of the expansion gas, and enhances the heat resistance of the heat-resistant reinforcing cloth. On the other hand, when the aluminum foil constituting the heat-resistant layer is used alone, it is liable to cause aged deterioration such as oxidation and electrolytic corrosion. For example, in a driver's airbag device, a metal (iron) ring retainer may be used when installing an inflator and an airbag, and the heat-resistant layer has moisture (including moisture in the air). Touching the ring retainer underneath may cause electrolytic corrosion. In the above-mentioned Patent Document 1 and Patent Document 2, no particular countermeasure is taken against such a phenomenon.

Further, depending on the material of the base cloth, it cannot be said that the strength (tensile, tearing) of the heat-resistant layer is sufficient. Therefore, in the heat-resistant reinforcing cloth, the heat-resistant layer may peel off from the base cloth when the airbag is deployed and expanded.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a heat-resistant reinforcing cloth for airbags capable of suppressing aging deterioration of the heat-resistant layer and peeling from the base cloth. be.

The heat-resistant reinforcing cloth for an airbag that solves the above problems is used for an airbag that is deployed and expanded by the expansion gas ejected from the gas ejection portion of the inflator, and among the members constituting the airbag, the expansion gas. A heat-resistant reinforcing cloth for an airbag in which at least one of the members in contact with the material is used as a member to be reinforced and the heat resistance of the member to be reinforced is reinforced. A heat-resistant layer made of an aluminum foil laminated on the surface of the base cloth on the gas ejection portion side, and a heat-resistant layer laminated on the surface of the heat-resistant layer on the gas ejection portion side. It is provided with a top coat layer made of a resin film.

According to the above configuration, in the heat-resistant reinforcing cloth arranged between the member to be reinforced and the gas ejection portion, the top coat layer made of a resin film covers the heat-resistant layer from the gas ejection portion side. This topcoat layer regulates oxygen from coming into contact with the heat resistant layer made of aluminum foil. The topcoat layer also regulates the heat-resistant layer from coming into contact with surrounding parts made of a metal material other than aluminum in the presence of moisture (including moisture in the air). As a result, aging deterioration due to oxidation and electrolytic corrosion of the heat-resistant layer is suppressed.

Further, the aluminum foil constituting the heat-resistant layer has a melting point higher than the temperature of the expansion gas and exhibits heat resistance. In addition, the aluminum foil has a gas barrier property at a certain film thickness or higher, and it regulates the permeation of high-temperature expansion gas to direct contact with the base cloth, so that the heat of the expansion gas is applied to the base cloth. Suppress transmission.

In addition to this, the carbonization point of the cotton fiber (cellulose) constituting the base fabric is as high as 500 ° C. to 580 ° C., which is higher than the melting point of a general resin. Therefore, the cotton fiber is less likely to be carbonized by the heat of the expansion gas and less likely to form holes.

Therefore, by using the heat-resistant reinforcing cloth, it becomes difficult for the heat of the expansion gas to reach the member to be reinforced. It is suppressed that the member to be reinforced is carbonized by the heat of the expansion gas, and the carbonized portion is scattered by the pressure of the expansion gas to form holes. In addition, since the heat-resistant reinforcing cloth itself has higher heat resistance than the member to be reinforced, the heat-resistant reinforcing cloth used to secure heat resistance is compared with the case where the same material as the member to be reinforced is used as the heat-resistant reinforcing cloth. The number of sheets is small. Therefore, the problem caused by the increase in the number of heat-resistant reinforcing cloths used, that is, the problem that the airbag becomes difficult to fold, the weight increases, the bulk when folded becomes large, and the mountability is lowered, and the like are solved.

When the heat-resistant reinforcing cloth is composed only of the aluminum foil, the strength such as tensile strength and tear strength is insufficient. As the airbag unfolds and expands, the aluminum foil itself is scattered by the pressure of the expansion gas. The same applies even when a thick aluminum foil is used, or when the heat-resistant reinforcing cloth is formed by laminating (laminating) only the top coat layer on the aluminum foil. However, by laminating the aluminum foil on the base cloth made of cotton fibers, the above-mentioned insufficient strength is compensated (reinforced) by the base cloth, and the scattering of the aluminum foil due to the pressure of the expansion gas is suppressed.

In particular, the heat-resistant layer made of aluminum foil is laminated on the base cloth made of cotton fibers, so that it is mechanically bonded to the base cloth due to the anchor effect and firmly adheres to the base cloth. .. Therefore, the phenomenon that the heat-resistant layer is peeled off from the base cloth when the airbag is deployed and expanded is suppressed, and the scattering of the aluminum foil due to the pressure of the expansion gas is suppressed.

In the heat-resistant reinforcing cloth for airbags, the base cloth is preferably made of a plain weave cloth.
According to the above configuration, in the plain weave cloth, since the warp and the weft are woven in a state where the warp and the weft are alternately crossed, the warp is more than the woven cloth woven by other weaving structures such as twill weave and satin weave. There are many intersections between the weave and the weave, and the strength such as tensile strength and tear strength is high. In addition, there is little difference in strength between the warp yarn arrangement direction and the weft yarn arrangement direction. Therefore, the effect of compensating for the insufficient strength of the alumnium foil can be obtained to the same extent in the warp yarn arrangement direction and the weft yarn arrangement direction.

Among the heat-resistant reinforcing cloths for airbags, those having a tensile strength of 400 Newton or more in both the warp yarn arrangement direction and the weft yarn arrangement direction when a test piece having a width of 3 cm is used as the plain weave cloth. It is preferable that it is used.

The above conditions are generally required for a member to be reinforced formed of polyamide fiber, polyester fiber, or the like. Therefore, by using a plain weave cloth having the strength satisfying the above conditions as the base cloth of the heat-resistant reinforcing cloth, the function of compensating for the insufficient strength of the aluminum foil is fully exhibited, and when the airbag is deployed and expanded, it is used for expansion. The scattering of the aluminum foil by the gas is effectively suppressed. Further, in order to satisfy the above conditions, the base fabric is woven at a high density, so that the effect of restricting the passage of the expansion gas and contact with the member to be reinforced can be expected.

In the heat-resistant reinforcing cloth for airbags, it is preferable that the aluminum foil having a thickness of 5 μm to 30 μm is used.
By using the aluminum foil having the above thickness, it is possible to suppress an increase in material cost while ensuring the necessary heat resistance.

Further, as the thickness of the aluminum foil increases, the number of pinholes decreases and the gas barrier property becomes higher.
In the heat-resistant reinforcing cloth for airbags, the top coat layer is preferably formed of a polyamide film, a polyethylene film, a stretched polypropylene film, a polyethylene terephthalate film, or a polyvinylidene chloride film.

By using the above-mentioned type of resin film as the top coat layer, the effect of restricting the contact of oxygen and moisture (including moisture in the air) with the aluminum foil can be sufficiently obtained.

According to the heat-resistant reinforcing cloth for airbags, it is possible to suppress aged deterioration of the heat-resistant layer and peeling from the base cloth.

It is a figure which shows the 1st Embodiment embodied in the heat-resistant reinforcing cloth for an airbag used for the airbag device for a driver's seat (hereinafter simply referred to as "heat-resistant reinforcing cloth"), and is the partial cross-sectional view which shows the application place of the heat-resistant reinforcing cloth. .. A partially enlarged cross-sectional view of the heat-resistant reinforcing cloth of the first embodiment. It is a figure which shows the 2nd Embodiment which applied the heat-resistant reinforcing cloth to the side airbag device, and is the side view which shows the vehicle seat provided with the device together with an occupant. In the second embodiment, a partial plan sectional view showing a state in which the airbag module is attached to the side frame portion. In the second embodiment, a partial vertical sectional view showing a state in which the airbag module is attached to the side frame portion. It is a figure which shows the 3rd Embodiment which applied the heat-resistant reinforcing cloth to the curtain airbag device, and is the schematic front view which shows the application part in the vehicle of the said device. Partial front view of the airbag module in the third embodiment. The partial front view which shows the X part in FIG. 7 enlarged. It is a figure which shows the modification of the heat-resistant reinforcing cloth in 2nd Embodiment, and is the partial plan sectional view corresponding to FIG. It is a figure which shows the modification of the gas generator in 2nd Embodiment, and is the partial vertical sectional view corresponding to FIG. It is a figure which shows the modification of the heat-resistant reinforcing cloth in 3rd Embodiment, and is the partial front view corresponding to FIG. It is a figure which shows the modification of the heat-resistant reinforcing cloth in 3rd Embodiment, and is the partial front view which shows the inner tube to which the heat-resistant reinforcing cloth is attached together with an inflator. FIG. 12 is a cross-sectional view taken along the line 13-13 in FIG. It is a figure which shows the modification of the heat-resistant reinforcing cloth in 1st Embodiment, and is the cross-sectional view which shows the rectifying cloth to which the heat-resistant reinforcing cloth is attached together with an inflator. The development view of the rectifying cloth in FIG. It is a figure which shows the modification of the heat-resistant reinforcing cloth in 1st Embodiment, and is the partial cross-sectional view which shows the airbag which attached the heat-resistant reinforcing cloth to the suture part.

(First Embodiment)
Hereinafter, the first embodiment embodied in the heat-resistant reinforcing cloth used for the driver's seat airbag device will be described with reference to FIGS. 1 and 2.

The driver airbag device is mounted on the steering wheel of the vehicle and shocks the driver by deploying and inflating the airbag when an impact is applied to the vehicle from the front or when an impact is expected to be applied. It is a device that protects from.

FIG. 1 shows a part of a driver's seat airbag device 10 arranged inside a pad portion (not shown) of a steering wheel in a vehicle. The front-rear direction in FIG. 1 indicates a direction along the steering shaft (not shown) of the steering wheel, and is slightly inclined with respect to the front-rear direction of the vehicle.

As shown in FIG. 1, the driver's seat airbag device 10 includes a bag holder 11, an inflator (gas generator) 14, an airbag 22, and a ring retainer 33. The bag holder 11 is supported by a core metal (not shown) of the steering wheel. An opening 12 is formed in the central portion of the bag holder 11. In the bag holder 11, screw insertion holes 13 are formed at a plurality of locations on the peripheral edge of the opening 12.

As the inflator 14, a disc type inflator is used. This type of inflator 14 includes a flat, substantially columnar main body portion 15 and a flange portion 18 formed on the outer peripheral surface of the main body portion 15. Inside the main body 15, a gas generator (not shown) that generates an expansion gas for deploying and expanding the airbag 22 is housed. The flange portion 18 is provided at an intermediate portion in the direction (front-back direction) along the axis of the main body portion 15. A plurality of mounting portions 19 extend outward in the radial direction of the main body portion 15 on the flange portion 18. In each mounting portion 19, a screw insertion hole 21 is formed at a position in front of the screw insertion hole 13 of the bag holder 11. The portion of the main body portion 15 on the rear side of the flange portion 18 constitutes the gas ejection portion 16. A plurality of gas ejection holes 17 for ejecting expansion gas outward in the radial direction are formed on the outer peripheral surface of the gas ejection portion 16.

The outer shell portion of the airbag 22 is composed of the main body cloth portion 23. The main body cloth portion 23 is formed of a woven cloth woven using polyamide fibers or polyester fibers, which are materials having high strength and flexibility. The main body cloth portion 23 is opened with an insertion port 24 for inserting the gas ejection portion 16. Screw insertion holes 25 are formed at a plurality of locations on the peripheral edge of the insertion port 24 of the main body cloth portion 23 and behind each screw insertion hole 13 of the bag holder 11.

The airbag 22 further includes a rectifying cloth (not shown) for rectifying the expansion gas ejected from the gas ejection unit 16.
The driver's seat airbag device 10 includes a heat-resistant reinforcing cloth 26 in addition to the airbag 22. Among the members constituting the airbag 22, the heat-resistant reinforcing cloth 26 has a main body cloth portion 23, which is one of the members with which the expansion gas ejected from the gas ejection portion 16 comes into contact, as a member to be reinforced, and the main body cloth portion thereof. It is used to reinforce the heat resistance of 23. As shown in FIG. 2, the heat-resistant reinforcing cloth 26 is composed of a base cloth 27, a heat-resistant layer 28, and a top coat layer 29, and has a three-layer structure.

The base cloth 27 is arranged between the main body cloth portion 23 and the gas ejection portion 16, and is composed of a plain weave cloth woven using threads (cotton threads) made of cotton fibers. The plain weave cloth has a thickness of 10 μm to 100 μm. In the first embodiment, a base cloth 27 having a thickness of 50 μm is used. In the plain weave cloth, the warp threads 27a and the weft threads 27b are woven in a state of being alternately crossed. The warp threads 27a and the weft threads 27b are each composed of a plurality of cotton fibers, but in FIG. 2, the illustration of each cotton fiber is omitted. As the plain weave cloth, a cloth having a tensile strength when a test piece having a width of 3 cm is used is 400 Newton or more in both the arrangement direction of the warp threads 27a and the arrangement direction of the weft threads 27b.

The heat-resistant layer 28 is made of an aluminum foil having a thickness of 5 μm to 30 μm, and is laminated on the surface of the base cloth 27 on the gas ejection portion 16 side. In the first embodiment, an aluminum foil having a thickness of 15 μm and having few small holes called pinholes is used as the heat-resistant layer 28.

The top coat layer 29 is made of a resin film having a thickness of 5 μm to 30 μm, and is laminated on the surface of the heat-resistant layer 28 on the gas ejection portion 16 side. As the resin film, a polyamide (PA) film, a polyethylene (PE) film, a stretched polypropylene (OPP) film, a polyethylene terephthalate (PET) film, or a polyvinylidene chloride (PVDC) film is used. The stretched polypropylene (OPP) film is a resin film in which oriented crystals are raised by being stretched vertically and horizontally in a manufacturing process. In the first embodiment, a resin film made of polyamide 66 having a thickness of 15 μm is used as the top coat layer 29.

The heat-resistant reinforcing cloth 26 having a three-layer structure is formed by laminating an aluminum foil on a plain weave cloth and a resin film on an aluminum foil by a laminating method such as dry laminating. Dry laminating is a method in which an adhesive is applied to the surface of one material to be laminated, the solvent is evaporated in a drying device, and the solvent is thermocompression bonded to the other material for laminating. Further, as a method of laminating the resin film on the aluminum foil, extruded coat laminating may be adopted. Extruded coat laminating is a method of melting a thermoplastic resin, extruding it into a film, and laminating it on a base material (in this case, aluminum foil).

As shown in FIG. 1, the heat-resistant reinforcing cloth 26 has an insertion port 31 for inserting the gas ejection portion 16 in its central portion. The heat-resistant reinforcing cloth 26 is overlapped with the main body cloth portion 23 from the inside in the base cloth 27 in a state where the insertion port 31 is aligned with the insertion port 24 of the main body cloth portion 23. Screw insertion holes 32 are formed at a plurality of locations on the peripheral edge of the insertion port 31 of the heat-resistant reinforcing cloth 26 and behind each screw insertion hole 13 of the bag holder 11.

The heat-resistant reinforcing cloth 26 is processed into a required shape by punching a long film (raw fabric) having a three-layer structure in which a resin film and a plain weave cloth are laminated on both sides of the alumnium foil as described above. Has been done.

A ring retainer 33 formed of a metal material (iron) different from the aluminum foil constituting the heat-resistant layer 28 is arranged inside the main body cloth portion 23 and in the vicinity of the insertion ports 24 and 31. There is. The ring retainer 33 has an opening 34 having the same shape as the opening 12 of the bag holder 11. Further, the ring retainer 33 has mounting screws 35 at a plurality of positions behind each screw insertion hole 13 of the bag holder 11.

Then, the gas ejection portion 16 of the inflator 14 is inserted into the openings 12, 34 of the bag holder 11 and the ring retainer 33, and the insertion ports 24, 31 of the main body cloth portion 23 and the heat-resistant reinforcing cloth 26. The flange portion 18 is overlapped with the bag holder 11 from the front side. Although not shown, many parts of the airbag 22 are folded into a compact form and housed between the pad portion and the bag holder 11.

The plurality of mounting screws 35 of the ring retainer 33 are inserted from the rear side into the screw insertion holes 32, 25, 13, 21 of the heat-resistant reinforcing cloth 26, the main body cloth portion 23, the bag holder 11 and the flange portion 18. .. By this insertion, the heat-resistant reinforcing cloth 26 is positioned with respect to the main body cloth portion 23. Further, by tightening the nut 36 from the front side to each mounting screw 35 after insertion, the main body cloth portion 23 and the heat-resistant reinforcing cloth 26 are fixed to the bag holder 11 via the ring retainer 33, and the inflator 14 is flanged. At 18, it is fixed to the bag holder 11.

Next, the operation and effect of the first embodiment configured as described above will be described.
When the impact from the front due to a frontal collision (front collision) or the like is not applied to the vehicle (normal time) or when it is not predicted that an impact will be applied to the vehicle, the driver airbag device 10 uses the gas ejection portion 16 of the inflator 14. The expansion gas is not ejected from the airbag 22 and the airbag 22 is maintained in the folded state.

At this time, in the heat-resistant reinforcing cloth 26, the top coat layer 29 made of a resin film covers the heat-resistant layer 28 from the gas ejection portion 16 side. The top coat layer 29 regulates oxygen from coming into contact with the heat-resistant layer 28 made of aluminum foil. Further, in the top coat layer 29, the heat-resistant layer 28 touches peripheral parts made of a metal material different from aluminum, for example, a ring retainer 33, etc., in a situation where there is moisture (including moisture in the air). To regulate. Therefore, it is possible to suppress aging deterioration due to oxidation and electrolytic corrosion of the heat-resistant layer 28 in the normal state before the driver's seat airbag device 10 is activated.

When an impact is applied to the vehicle from the front due to a front collision or the like, the driver tries to lean forward due to inertia. On the other hand, in the driver's seat airbag device 10, when it is detected that an impact is applied to the vehicle from the front, or when it is predicted that an impact is applied, the inflator 14 is operated and the gas of the gas ejection unit 16 is activated. The expansion gas is ejected outward in the radial direction from the ejection hole 17. This expansion gas hits the heat-resistant reinforcing cloth 26 around the gas ejection portion 16. The heat-resistant reinforcing cloth 26 regulates that the expansion gas directly hits the portion around the gas ejection part 16 in the main body cloth part 23.

When the expansion gas is supplied to the airbag 22, the airbag 22 expands and expands. As the pressing force applied to the pad portion by the main body cloth portion 23 of the airbag 22 increases, the pad portion is broken. The airbag 22 continues to deploy and expand rearward through the opening created by the rupture. The deployed and inflated airbag 22 is interposed in front of the driver who tries to lean forward due to an impact such as a front collision, restrains the driver's head, and protects the driver from the impact.

Here, the aluminum foil constituting the heat-resistant layer 28 has a melting point higher than the temperature of the expansion gas and exhibits heat resistance. Further, the aluminum foil has a gas barrier property at a certain film thickness or more, and restricts the permeation of high-temperature expansion gas from direct contact with the base cloth 27.

In addition to this, the carbonization point of the cotton fiber (cellulose) constituting the base cloth 27 is as high as 500 ° C. to 580 ° C., which is higher than the melting point of a general resin. Therefore, the cotton fiber is less likely to be carbonized by the heat of the expansion gas and less likely to form holes.

Therefore, by using the heat-resistant reinforcing cloth 26, the heat of the expansion gas is less likely to be transmitted to the main body cloth portion 23, and the main body cloth portion 23 is carbonized by the expansion gas, and the carbonized portion scatters to form holes. Can be suppressed. Further, since the heat-resistant reinforcing cloth 26 itself has higher heat resistance than the main body cloth portion 23, it is used for ensuring heat resistance as compared with the case where the same material as the main body cloth portion 23 is used as the heat-resistant reinforcing cloth. The number of heat-resistant reinforcing cloths 26 can be reduced. Therefore, there are problems due to the increase in the number of heat-resistant reinforcing cloths 26 used, that is, the airbag 22 becomes difficult to fold, the weight increases, the bulk when folded increases, the mountability decreases, the cost increases, and the like. The problem can be solved.

Further, when the heat-resistant reinforcing cloth is composed of only aluminum foil, the strength such as tensile strength and tear strength is insufficient, and when the airbag 22 expands and expands, the aluminum foil itself scatters due to the pressure of the expansion gas. do. The same applies even when a thick aluminum foil is used, or when the heat-resistant reinforcing cloth is formed by laminating only the top coat layer 29 on the aluminum foil. However, the above-mentioned insufficient strength can be supplemented (reinforced) by the base cloth 27, and the scattering of the aluminum foil due to the pressure of the expansion gas can be suppressed.

In particular, in a plain weave cloth, since the warp threads 27a and the weft threads 27b are woven in a state of being alternately crossed, the warp threads 27a and the weft threads are more than the woven cloth woven by other weaving structures such as twill weave and satin weave. There are many intersections with 27b, and the strength such as tensile strength and tear strength is high. Further, the plain weave cloth has a small difference in strength between the arrangement direction of the warp threads 27a and the arrangement direction of the weft threads 27b. Therefore, the effect that the base cloth 27 compensates for the insufficient strength of the alumnium foil can be obtained to the same extent in the arrangement direction of the warp threads 27a and the arrangement direction of the weft threads 27b.

Further, the heat-resistant layer 28 made of aluminum foil is laminated on the base cloth 27 made of cotton fibers, so that it is mechanically bonded to the base cloth 27 due to the anchor effect, and is attached to the base cloth 27. It is firmly attached. Therefore, it is possible to prevent the heat-resistant layer 28 from peeling off from the base cloth 27 when the airbag 22 is deployed and expanded, and to suppress the scattering of the heat-resistant layer 28 due to the pressure of the expansion gas.

Further, as the plain weave cloth, a cloth having a tensile strength when a test piece having a width of 3 cm is used is 400 Newton or more in both the warp yarn 27a arrangement direction and the weft yarn 27b arrangement direction. These conditions are generally required for the main body cloth portion 23 as a member to be reinforced formed of polyamide fiber, polyester fiber, or the like. Therefore, by using a plain weave cloth having a strength satisfying the above conditions as the base cloth 27, the function of compensating for the insufficient strength of the aluminum foil is effectively exhibited, and when the airbag 22 is deployed and expanded, it is used for expansion. The gas effectively suppresses the scattering of the aluminum foil. Further, the aluminum foil firmly adheres to the base cloth 27, and the peeling of the aluminum foil from the base cloth 27 is effectively suppressed. Further, in order to satisfy the above conditions, the base cloth 27 is woven at a high density. Therefore, the effect of restricting the expansion gas from passing through the base cloth 27 and touching the main body cloth portion 23 can be expected.

According to the first embodiment, the following effects can be obtained in addition to the above.
-As a heat-resistant reinforcing cloth, among cloths made of polyamide fibers, polyester fibers, etc., the surface on the side that comes into contact with the expansion gas is coated with a silicone resin that is resistant to the heat of the expansion gas, so-called silicone coat. Cloth is also known. In the silicone-coated cloth, it is necessary to coat the non-coated cloth with a silicone resin after the refining step. Moreover, the silicone resin itself has a high material cost. In addition, a large-scale coating facility is required to apply the silicone resin to the cloth with a constant film thickness. It also leads to cost increase from the viewpoint of coating processing cost and equipment depreciation. Therefore, the cost of the silicone-coated cloth becomes high, which pushes up the cost of the airbag.

On the other hand, in the first embodiment, the heat-resistant reinforcing cloth 26 is formed by using an aluminum foil, a cotton plain weave cloth, and a resin film. These materials are not special materials but are widely distributed in the market, and are inexpensive and easily available. Therefore, the material cost can be kept low.

Further, as described above, the heat-resistant reinforcing cloth 26 having a three-layer structure is formed by laminating the aluminum foil on the plain weave cloth and the resin film on the aluminum foil. Therefore, the manufacturing cost can be reduced as compared with the case where the cloth is coated with the silicone resin.

(Second Embodiment)
Next, a second embodiment in which the heat-resistant reinforcing cloth is applied to the side airbag device will be described with reference to FIGS. 3 to 5.

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 width direction (vehicle width direction) of the vehicle is used as a reference, the side approaching the central portion is defined as the inside of the vehicle, and the side away from the central portion is defined as the outside of 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 normal posture.

As shown in FIG. 3, the side airbag device 40 is located on the side of the occupant P1 when an impact is applied to the vehicle from the side due to a side collision (side collision) or the like, or when an impact is predicted to be applied. It is a device that protects the occupant P1 from impact by deploying and inflating the airbag 56 on the side.

In the vehicle, a vehicle seat 41 is arranged near the inside of the side wall portion of the vehicle. Here, the side wall portion refers to a vehicle component member arranged on the side portion of the vehicle, and mainly corresponds to a door, a pillar portion, and the like. The side wall portion corresponding to the front seat is a front door, a center pillar portion, or the like. The side wall portions corresponding to the rear seats are the rear portion of the rear door, the rear pillar portion, the front portion of the tire house, the rear quarter, and the like.

The vehicle seat 41 includes a seat cushion 42 that is attached to the floor of the vehicle body, and a seat back 43 that stands up from the rear portion of the seat cushion 42 in a state of being inclined so as to be located rearward toward the upper side. A seat frame forming the skeleton is arranged in the seat back 43. As shown in FIGS. 4 and 5, a part of the seat frame is composed of side frame portions 44 arranged on the outer side of the vehicle in the seat back 43.

A storage portion 46 is provided in the seat back 43 and adjacent to the side frame portion 44 on the outside of the vehicle, and the airbag module ABM constituting the main portion of the side airbag device 40 is accommodated in the storage portion 46. It is attached to the side frame portion 44. The airbag module ABM includes a gas generator 47, an airbag 56, and a heat-resistant reinforcing cloth 63 as constituent members. Next, each of these constituent members will be described.

<Gas generator 47>
The gas generator 47 includes a generator main body 48 which is a main part thereof, and a bolt 55 for attaching the generator main body 48 to the side frame portion 44 together with the airbag 56 and the heat-resistant reinforcing cloth 63.

The generator main body 48 includes an inflator 49 and a retainer 54 that covers the inflator 49, and has an elongated shape that extends substantially in the vertical direction as a whole. In the second embodiment, a cylinder type inflator is used as the inflator 49. The inflator 49 has a substantially columnar shape, and a gas generator (not shown) that generates an expansion gas is housed inside the inflator 49. The inflator 49 has a gas ejection portion 51 at the lower end portion. A plurality of gas ejection holes 51a for ejecting expansion gas outward in the radial direction are provided on the outer peripheral portion of the gas ejection portion 51. Further, a harness 52, which is an input wiring for an operation signal to the inflator 49, is connected to the upper end of the inflator 49 via a connector 53.

On the other hand, the retainer 54 constitutes the outer peripheral portion of the generator main body 48. The retainer 54 is a member that functions as a diffuser that controls the direction in which the expansion gas is ejected and also has a function of attaching the inflator 49 together with the airbag 56 and the like to the side frame portion 44. Most of the retainer 54 is formed in a substantially tubular shape by bending a plate material such as a metal plate. The retainer 54 is locked to the upper end of the inflator 49 by being crimped so that its upper end is reduced in diameter. The lower end of the retainer 54 is located lower than the lower end of the gas ejection portion 51 of the inflator 49.

The bolts 55 project toward the inside of the vehicle from two positions separated from each other in the vertical direction of the retainer 54.
The generator main body 48 may be a combination of the inflator 49 and the retainer 54. Further, the generator main body 48 may be composed of only the inflator 49. In this case, the bolt 55 is directly fixed to the inflator 49.

<Airbag 56>
The alternate long and short dash line in FIG. 3 shows the airbag 56 in a state where it is deployed in a plane without being filled with an expansion gas. Further, the airbag 56 shown by the alternate long and short dash line in FIG. 4 is folded to be compact. As shown in FIGS. 3 and 4, the outer shell portion of the airbag 56 is composed of the main body cloth portion 57. As the main body cloth portion 57, a material formed of the same material as the main body cloth portion 23 of the first embodiment is used. The main body cloth portion 57 is formed by joining a pair of cloth portions 58, 59 that are overlapped in the vehicle width direction. The above-mentioned coupling between the two cloth portions 58 and 59 is made at the peripheral coupling portion 61 provided on the peripheral peripheral portion thereof. The peripheral coupling portion 61 is formed by sewing in the second embodiment, but may be formed by other means such as adhesion.

The airbag 56 is expanded and expanded by the expansion gas supplied to the airbag 56. The airbag 56 can protect many parts of the upper body of the occupant P1, for example, from the waist PP to the shoulder PS, from impact when deployed and expanded between the vehicle seat 41 and the side wall portion. It is formed in shape and size.

An insertion port (not shown) for the gas generator 47 is formed at the rear end of the main body cloth portion 57. Further, the main body cloth portion 57 is provided with a partition portion for partitioning the inside into a plurality of rooms (expansion chambers), a rectifying portion for expansion gas, and the like as a part of the constituent members of the airbag 56. These compartments, rectifying portions, and the like are also formed by using the same material as the main body cloth portion 23 of the first embodiment.

Further, as shown in FIGS. 4 and 5, insertion holes 62 for inserting the bolts 55 are formed at two rear ends of the cloth portion 58 inside the vehicle, which are separated from each other in the vertical direction. Has been done.

<Heat-resistant reinforcing cloth 63>
Among the members constituting the airbag 56, the heat-resistant reinforcing cloth 63 has a main body cloth portion 57, which is one of the members with which the expansion gas ejected from the gas ejection portion 51 comes into contact, as a member to be reinforced, and the main body cloth portion thereof. It is used to reinforce the heat resistance of 57.

Although not shown, the heat-resistant reinforcing cloth 63 is a base cloth formed of cotton fibers, a heat-resistant layer made of aluminum foil, and a top coat layer made of a resin film, as in the first embodiment (see FIG. 2). Those having a three-layer structure composed of and are used.

The heat-resistant reinforcing cloth 63 is shown by a chain double-dashed line in FIG. The heat-resistant reinforcing cloth 63 is formed in a tubular shape with both upper and lower ends open so that the top coat layer is located on the inner peripheral side and the base cloth is located on the outer peripheral side. The heat-resistant reinforcing cloth 63 is arranged around the retainer 54 in a state of surrounding at least the gas ejection portion 51 of the inflator 49. A part of the heat-resistant reinforcing cloth 63 is located between the main body cloth portion 57 and the gas ejection portion 51. The lower end of the heat-resistant reinforcing cloth 63 is located below the lower end of the gas ejection portion 51. The upper end of the heat-resistant reinforcing cloth 63 is located higher than the upper bolt 55. The heat-resistant reinforcing cloth 63 is provided with insertion holes 64 for inserting the bolts 55 at two locations separated from each other in the vertical direction. By inserting the bolt 55 into these insertion holes 64, the heat-resistant reinforcing cloth 63 is locked to the gas generator 47.

The gas generator 47 and the heat-resistant reinforcing cloth 63 are tilted so that the gas ejection portion 51 is located at the lower end of the inflator 49 and is located at the rear side toward the upper portion, and the main body is passed through the insertion port. It is inserted into the rear end of the cloth portion 57 (see FIG. 3).

The bolt 55 protruding from the retainer 54 and inserted into the insertion hole 64 of the heat-resistant reinforcing cloth 63 is inserted into the corresponding insertion hole 62 of the cloth portion 58 inside the vehicle. By this insertion, the gas generator 47 and the heat-resistant reinforcing cloth 63 are locked in a positioned state with respect to the main body cloth portion 57.

The airbag 56 has a compact form as shown by a chain double-dashed line in FIG. 4 by folding a portion on the front side of the generator main body 48. This is because the airbag 56 is suitable for storage with respect to the storage portion 46 having a limited size in the seat back 43. The airbag 56 is held in a folded form by a binding tape (not shown).

The airbag module ABM in which the airbag 56 is held in a form suitable for storage is arranged in the storage unit 46. Then, both bolts 55 are inserted into the insertion holes 45 formed in the side frame portion 44 from the outside of the vehicle. By tightening the nut 65 from the inside of the side frame portion 44 to each bolt 55, the gas generator 47 and the heat-resistant reinforcing cloth 63 are attached to the side frame portion 44 together with the airbag 56.

Next, the operation and effect of the second embodiment configured as described above will be described.
When an impact from the side due to a side collision or the like is not applied to the side wall portion of the vehicle (normal time), the side airbag device 40 does not eject the expansion gas from the gas ejection portion 51 of the inflator 49. The airbag 22 is continuously stored in the storage unit 46 together with the gas generator 47 and the heat-resistant reinforcing cloth 63 in the folded form.

At this time, in the heat-resistant reinforcing cloth 63, the top coat layer regulates the easy contact of oxygen with the heat-resistant layer. Further, in the top coat layer, the heat-resistant layer touches peripheral parts made of a metal material different from aluminum, for example, a retainer 54, a bolt 55, etc., under a condition where there is moisture (including moisture in the air). To regulate. Therefore, it is possible to suppress aging deterioration due to oxidation and electrolytic corrosion of the heat-resistant layer in the normal state before the side airbag device 40 is operated.

On the other hand, when an impact is applied to the side wall portion from the side or the like due to a side collision or the like while the vehicle is running, or when it is predicted that an impact will be applied, the inflator 49 ejects expansion gas to the gas ejection portion 51. It spouts outward in the radial direction. A part of this expansion gas hits the heat-resistant reinforcing cloth 63 through the holes 54a provided at the lower end of the retainer 54. The heat-resistant reinforcing cloth 63 regulates that the expansion gas directly hits the portion around the gas ejection portion 51 in the main body cloth portion 57. Further, when the compartment, the rectifying portion, etc. are arranged near the gas ejection portion 51, the heat-resistant reinforcing cloth 63 regulates that the expansion gas directly hits the compartment, the rectifying portion, or the like.

When the expansion gas is supplied to the main body cloth portion 57, the airbag 56 starts expansion. The airbag 56 protrudes forward from the seat back 43 with a part (rear portion) thereof left in the storage portion 46 together with the gas generator 47 and the heat-resistant reinforcing cloth 63.

After that, the airbag 56 to which the expansion gas is supplied faces forward between the side wall portion and the upper body of the occupant P1 seated on the vehicle seat 41, as shown by the alternate long and short dash line in FIG. It expands while eliminating (unfolding) the folded state.

The airbag 56 deployed and expanded in this way is interposed between the upper body of the occupant P1 and the side wall portion entering the inside of the vehicle. The upper body is pressed and restrained inside the vehicle by the airbag 56. Then, the impact from the side transmitted to the upper body through the side wall portion is alleviated by the airbag 56, and the upper body is protected.

Here, the aluminum foil constituting the heat-resistant layer exhibits heat resistance and regulates that the high-temperature expansion gas permeates and comes into direct contact with the base fabric. Further, the cotton fibers constituting the base cloth are less likely to be carbonized by the heat of the expansion gas and are less likely to form holes.

Therefore, the heat of the expansion gas is not easily transmitted to the main body cloth portion 57, and is also difficult to be transmitted to the partition portion, the rectifying portion, etc. near the gas ejection portion 51. The expansion gas suppresses the phenomenon that the peripheral portion of the gas ejection portion 51 among the main body cloth portion 57, the compartment portion, the rectifying portion, and the like is carbonized, and the carbonized portion scatters to form holes. Further, the number of heat-resistant reinforcing cloths 63 used for ensuring heat resistance can be reduced. Problems such as difficulty in folding the airbag 56, an increase in weight, an increase in bulk when folded, a decrease in mountability, and an increase in cost are solved.

Further, when the heat-resistant reinforcing cloth 63 is composed of only the aluminum foil, the lack of strength such as tensile strength and tear strength can be reinforced by the base cloth, and the scattering of the aluminum foil due to the pressure of the expansion gas can be suppressed. In addition, since the heat-resistant layer firmly adheres to the base fabric due to the anchor effect, it is possible to prevent the heat-resistant layer from peeling off from the base cloth when the airbag 56 expands and expands, and the heat-resistant layer scatters due to the pressure of the expansion gas. Can be suppressed.

According to the second embodiment, other than the above-mentioned matters, the same effects as the various effects described in the first embodiment can be obtained.
(Third Embodiment)
Next, a third embodiment in which the heat-resistant reinforcing cloth is applied to the curtain airbag device will be described with reference to FIGS. 6 to 8.

The direction in the following description is the same as the direction in the second embodiment. Further, the same as in the second embodiment, the occupant having the same physique as the dummy for the collision test is seated on the vehicle seat in a predetermined normal posture.

As shown in FIG. 6, the curtain airbag device 70 deploys the airbag 77 between the occupants P1 and P2 and the side windows SW1 and SW2 when an impact is applied to the vehicle from the side due to a side collision or the like. It is a device that protects the head PH of the occupants P1 and P2 from impact by inflating and inflating.

As shown in FIGS. 6 and 7, the airbag module ABM constituting the main part of the curtain airbag device 70 includes a gas generator, an airbag 77, and a heat-resistant reinforcing cloth 95. The airbag module ABM is housed in the storage unit 71 and attached to the vehicle body. The storage portion 71 is located in a region near the upper side of the side windows SW1 and SW2 in the vertical direction. The storage portion 71 is located in a region from the front pillar portion FP to the vicinity of the rear pillar portion RP via the roof side rail portion RR in the front-rear direction.

Next, each of the above-mentioned members constituting the airbag module ABM will be described.
<Gas generator>
The gas generator is composed of a cylinder type inflator 73. However, in the third embodiment, unlike the second embodiment, the retainer is not used as a constituent member of the gas generator. The inflator 73 has a substantially columnar shape as in the second embodiment, and a gas generating agent (not shown) that generates an expansion gas is contained therein. The inflator 73 is arranged in the storage portion 71 in a posture extending in the front-rear direction. The inflator 73 has a gas ejection portion 74 at the front end portion. A plurality of gas ejection holes (not shown) for ejecting expansion gas outward in the radial direction are provided on the outer peripheral portion of the gas ejection portion 74. Further, a harness (not shown) serving as an input wiring for an operation signal to the inflator 73 is connected to the rear end of the inflator 73. The inflator 73 is attached to the ceiling portion of the vehicle body by a bracket 75 and a bolt 76.

<Airbag 77>
In FIG. 7, the airbag 77 is shown in a state where it is deployed in a plane without being filled with an expansion gas. As shown in FIGS. 6 and 7, the outer shell portion of the airbag 77 is composed of the main body cloth portion 78. As the main body cloth portion 78, a material formed of the same material as the main body cloth portion 23 of the first embodiment is used. The main body cloth portion 78 is formed by bag sewing so that its outer shape is a horizontally long rectangular shape extending in the front-rear direction. The main body cloth portion 78 has a shape and size capable of covering both the front side window SW1 and the rear side window SW2 and the front side portion of the rear pillar portion RP from the inside of the vehicle. As shown in FIGS. 7 and 8, the main body cloth portion 78 includes a gas supply path 79, a gas introduction portion 81, a front chamber 83, and a rear chamber 84.

The gas supply path 79 extends linearly in the front-rear direction at the upper part of the main body cloth portion 78.
The gas introduction section 81 is located above the gas supply path 79. The lower end of the gas introduction portion 81 is connected to the substantially central portion of the gas supply path 79 in the front-rear direction in a communicating state. When the airbag module ABM is attached to the vehicle body, the gas introduction portion 81 is located above the center pillar portion CP (see FIG. 6). The rear end of the gas introduction portion 81 is open.

As shown in FIGS. 6 and 7, the front chamber 83 and the rear chamber 84 are located below the gas supply path 79. The front chamber 83 communicates with the front of the gas supply path 79 and deploys and expands in the head protection area of the front seat occupant P1. The rear chamber 84 communicates with the rear of the gas supply path 79 and deploys and expands in the head protection area of the rear seat occupant P2.

In the main body cloth portion 78, a portion different from the gas supply path 79, the gas introduction portion 81, the front chamber 83 and the rear chamber 84 constitutes a non-expansion portion 85 in which expansion gas is not supplied and does not expand.

Mounting pieces 86 are joined by sewing or the like to a plurality of positions separated from each other in the front-rear direction on the upper edge portion of the main body cloth portion 78. The airbag module ABM is attached to the vehicle body with these attachment pieces 86.

Further, the rear end portion of the strap-shaped tension belt 87 is attached to the front end portion of the main body cloth portion 78. The tension belt 87 extends forward from the front end portion of the main body cloth portion 78, and is attached to the front pillar portion FP at its own front end portion.

The airbag 77 further includes an inner tube 91. As shown in FIGS. 7 and 8, the inner tube 91 includes an inlet portion 92, a front outflow portion 93, and a rear outflow portion 94, and is made of the same material as the main body cloth portions 23, 57, 78. The inlet portion 92 has a tubular shape and is arranged in the gas introduction portion 81. The rear end of the inlet 92 is open. The front outflow portion 93 has a tubular shape and extends forward from the lower end of the inlet portion 92 in the gas supply path 79. The rear outflow portion 94 has a tubular shape and extends rearward from the lower end of the inlet portion 92 in the gas supply path 79. Both the front end portion of the front outflow portion 93 and the rear end portion of the rear outflow portion 94 are open.

The front portion of the inflator 73 including the gas ejection portion 74 is inserted into the gas introduction portion 81 and the inlet portion 92 through the opening portion at the rear end portion thereof. The gas introduction portion 81 and the inlet portion 92 are fastened to the inflator 73 by a clamp 82 mounted around the rear end portion of the gas introduction portion 81.

<Heat-resistant reinforcing cloth 95>
Among the members constituting the airbag 77, the heat-resistant reinforcing cloth 95 has an inner tube 91, which is one of the members with which the expansion gas ejected from the gas ejection portion 74 comes into contact, as a member to be reinforced, and the inner tube 91 thereof. It is used to reinforce heat resistance.

Although not shown, the heat-resistant reinforcing cloth 95 is a base cloth formed of cotton fibers, a heat-resistant layer made of aluminum foil, and a top coat layer made of a resin film, as in the first embodiment (see FIG. 2). Those having a three-layer structure composed of and are used.

The heat-resistant reinforcing cloth 95 is formed in a tubular shape with both front and rear ends open so that the top coat layer is located on the inner peripheral side and the base cloth is located on the outer peripheral side. The heat-resistant reinforcing cloth 95 is arranged in the inlet portion 92 of the inner tube 91 between the gas ejection portion 74 and the inlet portion 92 in a state of surrounding at least the gas ejection portion 74 of the inflator 73. The front end of the heat-resistant reinforcing cloth 95 is located in front of the front end of the gas ejection portion 74, and the rear ends of the heat-resistant reinforcing cloth 95 are located at the rear ends of the gas introduction portion 81 and the inlet portion 92. The heat-resistant reinforcing cloth 95 is fastened to the inflator 73 together with the gas introduction portion 81 and the inlet portion 92 by the clamp 82.

As shown in FIG. 6, the airbag module ABM configured as described above is assembled as an elongated long member by folding the main body cloth portion 78 in a state before being mounted on the vehicle. .. The main body cloth portion 78 is held in a folded form by a fastening material (not shown) such as a tape material. As the fastening material, a material that is broken when the airbag 77 is deployed and expanded is used.

Next, the operation and effect of the third embodiment configured as described above will be described.
When an impact from the side due to a side collision or the like is not applied to the side wall portion of the vehicle (normal time), the curtain airbag device 70 does not eject the expansion gas from the gas ejection portion 74 of the inflator 73. The airbag 77 continues to be stored in the storage section 71 together with the inflator 73 and the heat-resistant reinforcing cloth 95 in a folded form.

At this time, in the heat-resistant reinforcing cloth 95, the top coat layer regulates the easy contact of oxygen with the heat-resistant layer. In addition, the topcoat layer regulates the heat-resistant layer from touching peripheral parts made of a metal material different from aluminum in the presence of moisture (including moisture in the air). Therefore, in the normal state before the curtain airbag device 70 is operated, it is possible to suppress aging deterioration due to oxidation of the heat-resistant layer and electrolytic corrosion.

On the other hand, when an impact is applied to the side wall portion from the side or the like due to a side collision or the like while the vehicle is running, or when it is predicted that an impact will be applied, the inflator 73 ejects expansion gas to the gas ejection portion 74. It spouts outward in the radial direction. A part of this expansion gas hits the heat-resistant reinforcing cloth 95 around the gas ejection portion 74. The heat-resistant reinforcing cloth 95 regulates that the expansion gas directly hits the portion around the gas ejection portion 74 in the inner tube 91.

The expansion gas is divided into a gas flowing through the front outflow portion 93 and a gas flowing through the rear outflow portion 94 after passing through the inlet portion 92 of the inner tube 91. The expansion gas flowing out from the front outflow portion 93 is supplied to the front chamber 83 by flowing forward through the gas supply path 79. The expansion gas flowing out from the rear outflow portion 94 is supplied to the rear chamber 84 by flowing backward through the gas supply path 79. The supplied expansion gas initiates expansion of the front chamber 83 and the rear chamber 84. The airbag 77 protrudes downward from the storage unit 71 with a part of the airbag 77 left in the storage unit 71.

As shown in FIGS. 6 and 7, the airbag 77 expands and expands from the storage portion 71 along the side windows SW1 and SW2 in a curtain shape. The front chamber 83 expands and expands between the head PH of the front seat occupant P1 and the front side window SW1 to protect the head PH of the occupant P1 from impact. The rear chamber 84 expands and expands between the head PH of the occupant P2 in the rear seat and the side window SW2 on the rear side, and protects the head PH of the occupant P2 from impact.

Here, the aluminum foil constituting the heat-resistant layer exhibits heat resistance and regulates that the high-temperature expansion gas permeates and comes into direct contact with the base fabric. Further, the cotton fibers constituting the base cloth are less likely to be carbonized by the heat of the expansion gas and are less likely to form holes.

Therefore, the heat of the expansion gas is not easily transferred to the inlet portion 92 of the inner tube 91, and the peripheral portion, particularly the upper portion of the gas ejection portion 74 of the inlet portion 92 is carbonized, and the carbonized portion scatters to form a hole. It can be suppressed. Further, the number of heat-resistant reinforcing cloths 95 used for ensuring heat resistance can be reduced. Therefore, problems such as difficulty in folding the airbag 77, an increase in weight, an increase in bulk when folded, a decrease in mountability in a narrow storage portion 71, and an increase in cost are solved.

Further, the lack of strength such as tensile strength and tear strength when the heat-resistant reinforcing cloth is formed only by the aluminum foil can be compensated by the base cloth, and the scattering of the aluminum foil due to the pressure of the expansion gas can be suppressed. In addition, since the heat-resistant layer firmly adheres to the base fabric due to the anchor effect, it is possible to prevent the heat-resistant layer from peeling off from the base cloth when the airbag 77 expands and expands, and the heat-resistant layer scatters due to the pressure of the expansion gas. Can be suppressed.

According to the third embodiment, other than the above-mentioned matters, the same effects as the various effects described in the first embodiment can be obtained.
It should be noted that each of the above-described embodiments can also be implemented as a modified example in which the above is modified as follows.

<Matters relating to the first embodiment>
The heat-resistant reinforcing cloth 26 can be applied not only to the driver airbag device 10 but also to the passenger airbag device.

The passenger seat airbag device is installed in the front part of the passenger seat in the instrument panel, and the airbag is applied when an impact is applied to the vehicle from the front due to a front collision or the like, or when an impact is expected to be applied. Is a device that protects the passenger seat occupants from impact by deploying and inflating in front of the passenger seat. Also in this passenger seat airbag device, a disc type inflator similar to the driver's seat airbag device 10 is used.

As a rectifying cloth 102 (not shown in the first embodiment) for rectifying the expansion gas ejected from the gas ejection part 16, as shown in FIGS. 14 and 15, the band-shaped cloth portion 103 forms an annular shape. The one that has been used may be used. Both end portions 104 in the length direction of the cloth portion 103 are overlapped inside the rectifying cloth 102. Both end portions 104 are connected to each other by a suture portion 105 behind the gas ejection portion 16. An insertion port 106 for inserting the gas ejection portion 16 is opened in the central portion of the cloth portion 103 in the length direction. Screw insertion holes 107 (not shown in FIG. 14) through which the mounting screws 35 (see FIG. 1) of the ring retainer 33 are inserted are formed at a plurality of locations around the insertion port 106 in the cloth portion 103.

The expansion gas ejected from the gas ejection portion 16 comes into contact with the suture portion 105. Therefore, the sewn portion 105 may be used as a heat-resistant reinforcing target member with a heat-resistant reinforcing cloth. FIG. 14 shows a modified example in which a pair of heat-resistant reinforcing cloths 108 having the same three-layer structure as the heat-resistant reinforcing cloths 26 are arranged between the gas ejection part 16 and the sutured parts 105. Each heat-resistant reinforcing cloth 108 has a strip shape and is folded in half. The heat-resistant reinforcing cloth 108 does not have to be folded in half. Both heat-resistant reinforcing cloths 108 sandwich a pair of end portions 104 from both sides in the thickness direction (vertical direction of FIG. 14). Both heat-resistant reinforcing cloths 108 are connected to both end portions 104 of the rectifying cloth 102 (cloth part 103) by a sewn part 109 provided on the gas ejection part 16 side of the sewn part 105.

In this modification, a part of the expansion gas ejected from the gas ejection portion 16 hits both heat-resistant reinforcing cloths 108. The expansion gas is restricted from directly hitting the suture portion 105 by both heat-resistant reinforcing cloths 108. The heat of the expansion gas is less likely to be transferred to the suture portion 105, and the suture portion 105 is carbonized by the expansion gas, and it is possible to prevent the carbonized portion from scattering.

As shown in FIG. 16, the outer shell portion of the airbag 22 is composed of a pair of main body cloth portions 23 arranged in the front-rear direction, and the peripheral portions 111 of each main body cloth portion 23 are inside the airbag 22. They may be overlapped in and joined by the suture portion 112.

The expansion gas ejected from the gas ejection portion 16 (see FIG. 1) comes into contact with the suture portion 112. Therefore, the sewn portion 112 may be used as a heat-resistant reinforcing target member with a heat-resistant reinforcing cloth. FIG. 16 shows a modified example in which a pair of heat-resistant reinforcing cloth 113 having a three-layer structure similar to that of the heat-resistant reinforcing cloth 26 is arranged between the gas ejection portion 16 and the sutured portion 112. Both heat-resistant reinforcing cloths 113 sandwich a pair of peripheral edge portions 111 from both sides in the thickness direction (left-right direction in FIG. 16). Both heat-resistant reinforcing cloths 113 are connected to both peripheral edges 111 by a sewn portion 114. At least a part of the suture portion 114 is provided on the gas ejection portion 16 side of the suture portion 112. In FIG. 16, the sewn portion 114 is provided at two locations on the sewn portion 112, one on the side closer to the gas ejection portion 16 and the other on the side far from the gas ejection portion 16.

In this modification, a part of the expansion gas ejected from the gas ejection portion 16 hits both heat-resistant reinforcing cloths 113. The expansion gas is restricted from directly hitting the suture portion 112 by both heat resistant reinforcing cloths 113. The heat of the expansion gas is less likely to be transferred to the suture portion 112, and the suture portion 112 is carbonized by the expansion gas, and it is possible to prevent the carbonized portion from scattering.

<Matters relating to the second embodiment>
-The heat-resistant reinforcing cloth 63 is applicable not only to the side airbag device 40 but also to the knee-protecting airbag device.

The knee protection airbag device includes an airbag that is stored in a storage portion provided on an instrument panel or the like of a vehicle. The knee protection airbag device deploys and inflates the airbag with an expansion gas when an impact is applied to the vehicle from the front due to a front collision or the like, or when an impact is expected to be applied, and the occupant's knees. It is a device that protects the knee by restraining the movement of the part forward. Also in this knee protection airbag device, a cylinder type inflator similar to the side airbag device 40 is used.

The heat-resistant reinforcing cloth 63 may be arranged at least between a portion of the main body cloth portion 57 constituting the outer shell portion of the airbag 56, which is easily affected by the heat of the expansion gas, and the gas ejection portion 51. is important. The heat-resistant reinforcing cloth 63 may or may not be arranged between the portion of the main body cloth portion 57 that is not so affected by the heat of the expansion gas and the gas ejection portion 51.

In the case of the side airbag device 40, the heat-resistant reinforcing cloth 63 may be arranged so as to surround the entire circumference of the retainer 54, or may be arranged so as to surround only a part of the retainer 54 in the circumferential direction. In the modified example of FIG. 9, the heat-resistant reinforcing cloth 63 is arranged between the main body cloth portion 57 and the gas ejection portion 51 so as not to surround the front portion of the retainer 54. Even with this modification, it is possible to suppress the peripheral portion of the gas ejection portion 51 of the main body cloth portion 57 from being affected by the heat of the expansion gas.

-As the heat-resistant reinforcing cloth 63, a cloth shorter than that of the second embodiment may be used. However, it is preferable that the upper end of the heat-resistant reinforcing cloth 63 in FIG. 5 is set higher than the gas ejection portion 51 and the lower bolt 55. This is because the heat of the expansion gas is less likely to be transmitted to the peripheral portion of the gas ejection portion 51 of the main body cloth portion 57, and the heat-resistant reinforcing cloth 63 is locked to the main body cloth portion 57. For example, the upper end of the heat-resistant reinforcing cloth 63 may be set between both bolts 55.

As shown in FIG. 10, as the retainer 54, one whose lower end is located higher than the upper end of the gas ejection portion 51 and does not cover the gas ejection portion 51 may be used. Bolts 55 may be provided on both the retainer 54 and the inflator 49. In this case, a part of the expansion gas ejected outward from the gas ejection portion 51 hits the heat-resistant reinforcing cloth 63 without passing through the retainer 54. The heat-resistant reinforcing cloth 63 regulates that the expansion gas directly hits the portion around the gas ejection portion 51 in the main body cloth portion 57. Further, when the compartment, the rectifying portion, etc. are arranged near the gas ejection portion 51, the heat-resistant reinforcing cloth 63 regulates that the expansion gas directly hits the compartment, the rectifying portion, or the like.

<Matters relating to the third embodiment>
-For the same reason as described in the matters relating to the second embodiment, the arrangement mode of the heat-resistant reinforcing cloth 95 may be changed in the curtain airbag device 70 as well. That is, the heat-resistant reinforcing cloth 95 may or may not be arranged between the inlet portion 92 of the inner tube 91, which is not so affected by the heat of the expansion gas, and the gas ejection portion 74. You may. The heat-resistant reinforcing cloth 95 may be arranged so as to surround only a part of the inflator 73 in the circumferential direction. In the modified example of FIG. 11, the heat-resistant reinforcing cloth 95 is arranged so as not to surround the lower half of the gas ejection portion 74.

Further, of the inlet portion 92, not only the radial outer side of the gas ejection portion 74 but also the front portion of the gas ejection portion 74 is easily affected by the heat of the expansion gas, and carbonization due to heat may become a problem. be. Therefore, as shown in FIG. 11, a heat-resistant reinforcing cloth 96 having a three-layer structure similar to that of the heat-resistant reinforcing cloth 95 may be arranged at the front portion of the gas ejection portion 74 of the inlet portion 92. By doing so, it is possible to prevent the front portion of the inlet portion 92 from being carbonized by the heat of the expansion gas.

As shown in FIGS. 12 and 13, as the inner tube 91, two cloth portions 97 stacked in the vehicle width direction are joined by a sewn portion 98 provided on their peripheral edges. May be done. In FIG. 12, the sutured portion 98 is represented by intermittently arranging thick lines of a certain length in order to distinguish them from the broken lines (hidden lines). This point is the same for the sutured portion 101, which will be described later.

The expansion gas ejected from the gas ejection portion 74 comes into contact with the suture portion 98. Therefore, the sewn portion 98 may be used as a heat-resistant reinforcing target member with a heat-resistant reinforcing cloth. In FIGS. 12 and 13, a heat-resistant reinforcing cloth 99 having a three-layer structure similar to that of the heat-resistant reinforcing cloth 95 is formed between the gas ejection portion 74 and a portion of the sutured portion 98 below the gas ejection portion 74. An example of the arranged modification is shown. The heat-resistant reinforcing cloth 99 is connected to both cloth portions 97 by a sewn portion 101.

In this modification, a part of the expansion gas ejected outward from the gas ejection portion 74 hits the heat-resistant reinforcing cloth 99. The heat-resistant reinforcing cloth 99 regulates that the expansion gas directly hits the portion of the sutured portion 98 below the gas ejection portion 74. The heat of the expansion gas is less likely to be transferred to the suture portion 98, and the suture portion 98 is carbonized by the expansion gas, and it is possible to prevent the carbonized portion from scattering.

<Matters common to the second and third embodiments>
-As the cylinder type inflators 49 and 73, an inflator of a type that generates gas using a gas generating agent may be used, or a hybrid type inflator that uses both a gas generating agent and a high-pressure gas is used. You may. In a hybrid inflator, the igniter is ignited first, and the heat generated by the igniter ignites the gas generator. The high-pressure gas is warmed by the heat of the gas generated by the combustion of the gas generating agent and the pressure rises, and the pressurized high-pressure gas is ejected from the gas ejection part as an expansion gas. In either method, high-temperature and high-pressure expansion gas is ejected from the gas ejection portions 51 and 74. Therefore, by using the heat-resistant reinforcing cloths 63, 95, 96, 99, it is possible to suppress the aged deterioration of the heat-resistant layer and the peeling from the base cloth.

<Matters common to the first to third embodiments>
-A plurality of heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 may be stacked and arranged between the reinforcing target member and the gas ejection portions 16, 51, 74. Further, one heat-resistant reinforcing cloth 26, 63, 95, 96, 99, 108, 113 is folded to form a plurality of layers, and then between the member to be reinforced and the gas ejection parts 16, 51, 74. It may be arranged.

-The heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 may be connected to the member to be reinforced by a joining means such as stitching or adhesion.
Here, when a large number of reinforcing cloths made of the same material as the main body cloth portions 23, 57, 78 are stacked and used to ensure heat resistance, suturing becomes difficult. On the other hand, in the case of the heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113, since the number of sheets used can be small as described above, suturing becomes easy.

-Of the members constituting the airbags 22, 56, 77, one or a plurality of members with which the expansion gas comes into contact are designated as reinforcement target members, and between all the reinforcement target members and the gas ejection portions 16, 51, 74. Heat resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 may be arranged.

The heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 include the above-mentioned driver airbag device 10, passenger airbag device, side airbag device 40, knee airbag device, and curtain. It may be used for an airbag device having a form different from that of the airbag device 70.

-The heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 can be applied not only to private cars but also to airbag devices installed in various industrial vehicles.
Further, the heat-resistant reinforcing cloths 26, 63, 95, 96, 99, 108, 113 can be applied to an airbag device which is installed in a vehicle other than a vehicle, for example, an aircraft, a ship, etc., and protects an occupant from an impact. be.

In addition, the technical ideas that can be grasped from the above embodiments will be described together with their effects.
(A) In the heat-resistant reinforcing cloth for airbags according to any one of claims 1 to 5, the top coat layer has a thickness of 5 μm to 30 μm.

By using a topcoat layer having the above thickness, the phenomenon that oxygen or moisture (including moisture in the air) comes into contact with the heat-resistant layer made of aluminum foil is effectively regulated.

(B) The heat-resistant reinforcing cloth for airbags according to any one of claims 1 to 5 and (a) above, which has a thickness of 10 μm to 100 μm is used as the base cloth.
By using a base cloth having the above thickness, the required heat resistance can be obtained and the lack of strength of the aluminum foil can be effectively compensated. In addition, it is possible to prevent the airbag from becoming difficult to fold and from becoming excessively bulky when folded.

14,49,73 ... Inflator, 16,51,74 ... Gas ejection part, 22,56,77 ... Airbag, 23,57 ... Main body cloth part (reinforcing target member), 26,63,95,96,99, 108, 113 ... Heat resistant reinforcing cloth, 27 ... Base cloth, 27a ... Warp, 27b ... Weft, 28 ... Heat resistant layer, 29 ... Top coat layer, 91 ... Inner tube (reinforcing target member), 98, 105, 112 ... Sutured portion (Member to be reinforced).

Claims (5)

It is housed in a storage portion provided in the area above the side window of the vehicle, and is between the side window and the head of an occupant seated on the vehicle seat by the expansion gas ejected from the gas ejection portion of the inflator. in used in airbag deployment and inflation in a curtain shape, among the members constituting the airbag, provided with a tubular inlet section having a region extending downward is provided in the interior of the airbag, For airbags, the inner tube that the expansion gas comes into contact with by accommodating the gas ejection portion in the downwardly extending region of the inlet portion is used as the reinforcement target member, and the heat resistance of the reinforcement target member is reinforced. It is a heat-resistant reinforcing cloth
A base cloth formed of cotton fibers and arranged between the reinforcing target member and the gas ejection portion, and
A heat-resistant layer made of aluminum foil laminated on the surface of the base cloth on the gas ejection portion side,
Bei example a top coat layer comprising a resin film is laminated on a surface of the gas ejection portion of said heat-resistant layer,
A heat-resistant reinforcing cloth for airbags, which is arranged so as not to surround the lower half of the gas ejection portion of the inlet portion. The heat-resistant reinforcing cloth for an airbag according to claim 1, wherein the base cloth is made of a plain weave cloth. The second aspect of claim 2, wherein a plain weave cloth having a tensile strength of 400 Newton or more in both the warp yarn arrangement direction and the weft yarn arrangement direction when a test piece having a width of 3 cm is used is used. Heat resistant reinforcement cloth for airbags. The heat-resistant reinforcing cloth for an airbag according to any one of claims 1 to 3, wherein a foil having a thickness of 5 μm to 30 μm is used as the aluminum foil. The heat-resistant reinforcing cloth for an airbag according to any one of claims 1 to 4, wherein the top coat layer is formed of a polyamide film, a polyethylene film, a stretched polypropylene film, a polyethylene terephthalate film, or a polyvinylidene chloride film.

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