JPH0687104U - Airbag bag - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain an airbag bag body having an exhaust portion that is highly stable against scratches and the like when the internal pressure reaches a set value during inflation. [Structure] The woven fabric that constitutes the attachment-side main body fabric 24 is divided into three regions, and the third region 34 is weaker than the first region 30 and the second region 32. The first region 30 is made of plain weave fabric using nylon 66 yarns for both warp and weft yarns, and the second region 32 uses nylon 66 yarns for warp yarns and alternates nylon 66 yarns and rayon yarns for weft yarns. The third region 34 has the same yarn as that of the second region 32 but has a different weave design. A plurality of warp yarns are laid over a nylon yarn of the weft yarn, and the weft yarns are cut to facilitate breaking of the woven fabric. When the internal pressure becomes equal to or higher than the set value, the third region 34 breaks and the gas is exhausted to the outside.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a technique for preventing an excessive increase in internal pressure during inflation of an airbag bag.

[0002]

[Prior art]

 As means for preventing an excessive increase in internal pressure when the airbag bag body is inflated, a means for providing a ventilation hole in the airbag bag body is known. However, the gas leaks to the outside through the vent holes even during the expansion process of the air bag bag body, which is not preferable because the expansion speed becomes small when rapid expansion is required such as a collision. In order to solve this problem, Japanese Patent Laid-Open Publication No. 2-132554 discloses a means for forming a vent hole in an airbag bag and covering the vent hole with a film-like sheet material. The means described in the above publication covers the vent hole with a film that is torn when the internal pressure of the airbag bag exceeds a preset value. When the pressure inside the air bag bag is below the set value, the film that covers the ventilation holes prevents gas from leaking to the outside and allows for good inflation, resulting in abnormal inflation or pressure by the occupant during a collision, etc. When a high pressure is applied due to, the film is broken and the internal pressure is released to the outside.

[0003]

[Problems to be solved by the device]

 However, when the bag body for an airbag is inflated, the film may be broken before the predetermined internal pressure is reached, and the above purpose may not be sufficiently fulfilled. If the film has scratches, etc., when internal pressure is applied to the airbag bag, or before that, cracks will grow from the scratches, and the film will easily tear, resulting in poor expansion. Of. Therefore, it is an object of the present invention to obtain an airbag bag body that is capable of maintaining required performance even when cracks do not easily grow even with such small scratches.

[0004]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, a first invention is an airbag bag having an exhaust part for preventing an excessive rise in internal pressure, wherein the exhaust part is made of a fabric, and the fabric is made of the airbag bag. The gist is that the strength is smaller than other parts. At this time, the strength of the exhaust portion made of a woven fabric is set to the strength required for controlling the internal pressure of the airbag bag. The exhaust part may be configured so that the fabric covers the ventilation holes formed in the airbag bag body in advance, and when the airbag bag body is made of fabric, the air bag is formed. It may be formed integrally with the other part of the bag body. The exhaust part does not necessarily have to be made of a fabric alone, and a film or the like may be used together.

In the second invention, at least a part of the threads constituting the woven fabric is made of a material having a lower strength than the other portions of the airbag bag body. The gist is that a small woven fabric is constructed. In the woven fabric, all the yarns may be made of yarns having a lower strength than other portions of the airbag bag body, or a specific portion of the woven fabric may be made of a yarn having a weak strength, Alternatively, weak yarns may be arranged dispersed in the woven fabric.

[0006] A third aspect of the present invention is summarized as a fabric having low strength according to the first aspect of the present invention is configured by cutting at least a portion of some of the threads forming the fabric. . This woven fabric may be one in which some of the yarns forming the woven fabric are cut, or may be in which some of the yarns themselves are cut.

According to a fourth aspect of the invention, in the portion in which the thread that is at least partially cut in the third aspect continuously crosses over a plurality of adjacent threads among the threads that are orthogonal to the thread. The point is that it is cut.

[0008]

[Action]

 In the first invention, the exhaust part is made of a fabric having a lower strength than the other parts of the airbag bag, so that the gas is kept outside while the internal pressure of the airbag bag is below the set value. Expansion takes place without leakage. Also, when the internal pressure of the airbag bag reaches the set value, the woven fabric portion is broken and the gas inside is released to the outside. Even if there are small scratches on the woven fabric, the scratches do not grow like in the film, so that the pressure regulation inside the airbag bag is well performed.

The woven fabric is composed of a plurality of independent fibers, and the yarn is also composed of a plurality of independent fibers. Therefore, even if a part of the fabric is damaged, the damage is independent of other parts of the fabric and does not directly affect the breakage of other parts of the fabric. However, the pressure inside the airbag bag cannot be sufficiently borne at the damaged part, and the force applied to the yarn at the edge of the tear becomes large and the yarn is easily broken. Although a decrease in strength is unavoidable, it is much smaller than the decrease in strength caused by the growth of cracks in the film. Further, in the weaving process, it is possible to change the type of yarn constituting the woven fabric and the woven structure. Therefore, when the airbag bag body is made of woven fabric, the woven fabric and the It is also possible to integrally form the woven fabric forming the bag body.

In the second invention, since at least a part of the thread forming the woven fabric is made of a material having a lower strength than the other parts of the airbag bag, the internal pressure of the airbag bag is reduced. When the set value is reached, the internal pressure is released to the outside from the woven fabric portion having the thread of the material having low strength. For example, if yarns that make up a woven fabric and are oriented in the same direction are used alternately with high-strength yarns and low-strength yarns, when the low-strength yarns break, the The high-strength yarn adjacent to the yarn is cut to form a ventilation hole. The internal pressure of the air bag body is evenly applied to the entire surface area of the air bag body including the fabric forming the exhaust portion. Therefore, after the yarn with low strength is broken, the internal pressure of the adjacent yarn with high strength becomes large, and the yarn is easily broken, and the woven fabric in the portion having the yarn with low strength is broken. Therefore, the use of woven fabric not only makes it less susceptible to the effects of small scratches, but also adjusts the strength of the woven fabric by adjusting the distribution and proportion of the low-strength and high-strength yarns in the fabric. can do. This is because by adjusting the position and size of a kind of scratch formed after the low-strength yarn is broken, the internal pressure load of the high-strength yarn near the low-strength yarn can be adjusted.

In the third invention, a part of the threads constituting the woven fabric is at least partially cut, and thus the cut threads when the internal pressure of the airbag bag reaches a set value. The internal gas is released to the outside from the fabric portion having the. If a part of the yarns forming the woven fabric is cut, as in the case of the second invention, the yarns in the vicinity of the cut yarns are easily cut, and the portion having the cut yarns is easily cut. The strength of the fabric is reduced. Therefore, when the internal pressure of the airbag bag reaches the set value, the woven fabric is broken at the portion having the cut thread, and the gas inside is released to the outside. Further, when a part of the yarn itself is cut, first, the partially cut yarn is completely cut, and then the constituent yarns in the vicinity thereof are cut to break the woven fabric. Therefore, the use of woven fabric not only makes it less susceptible to small scratches, but it also adjusts the position and distribution of the cuts, which is a kind of artificially created scratch, and makes it close to the cut thread. By adjusting the pressure load on the yarn, it is possible to adjust the fabric strength. Since the strength of the woven fabric can be adjusted as desired regardless of the material of the yarns that make up the woven fabric, the woven fabric that composes the exhaust part, especially when the airbag bag body is made of woven fabric. It is possible to weave the other part of the airbag body together with the same material.

In the fourth invention, when a part of the threads continuously crosses over a plurality of the threads which are orthogonal to the part of the threads and are adjacent to each other, the part of the threads is It is easy to cut. A yarn that continuously crosses over a plurality of yarns can be lifted from the fabric by lifting or the like, so that the yarn can be easily cut. The second device and the third device may be implemented independently of each other or may be implemented in combination. Further, the fourth invention can be applied in combination of the second invention and the third invention.

[0013]

[Effect of device]

 As described above, if the exhaust portion is made of a fabric having low strength according to the first invention, the internal pressure of the airbag bag can be regulated satisfactorily without being affected by small scratches. Further, when the airbag bag body is made of a woven fabric, the exhaust part can be integrally formed. When a material having low strength is used for the yarn constituting the woven fabric according to the second invention, not only the internal pressure of the airbag bag can be regulated well, but also the strength of the woven fabric can be adjusted during weaving. Manufacturing of the airbag bag is facilitated. According to the third aspect, when the exhaust portion is made of a woven fabric in which a part of the yarn is cut, not only can the internal pressure of the airbag bag be regulated well, but the woven fabric can be adjusted by adjusting the thread cutting degree. You can adjust the strength of. Further, when the airbag bag is made of a woven fabric, the exhaust part and the other portion of the airbag bag can be integrally formed. According to the fourth invention, when a part of the threads straddles a plurality of threads which are adjacent to each other and are orthogonal to the thread, the thread can be easily cut and the third invention can be easily implemented.

[0014]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an airbag bag body 20 according to an embodiment of the present invention. The airbag bag body 20 is formed by stitching a passenger-side body cloth 22 and a mounting-side body cloth 24, which are made of a woven fabric, and the mounting-side body cloth 24 has a connection port 26 to an inflator. It is provided. The connection port 26 is formed by punching with a press machine after the patch cloth 28 is sewn. The yarns constituting the woven fabric are weft yarns in the upper and lower directions and warp yarns in the left and right directions in the drawings, and the same applies to each of the subsequent drawings.

The passenger-side main body fabric 22 has a plain weave design made of nylon 66 yarn with a thickness of 420 d, and the density thereof is about 20 warp / weft yarns / cm. In addition, one surface of the cloth is coated with silicon with a thickness of about 0.02 mm, and the surface is the inner surface of the airbag bag body 20.

The attachment-side main body cloth 24 is formed by integrally forming three regions 30, 32, and 34, which are different from each other, such as yarns forming a woven fabric. The third region 34 is made weaker than the first region 30 and the second region 32 to form an exhaust unit that allows gas to escape to the outside when the internal pressure of the airbag body 20 exceeds a set value. There is.

The first region 30 has a plain weave design in which both warp yarns and weft yarns are made of nylon 66 yarn having a thickness of 420 d, and the weave density thereof is about 18 yarns / cm. The second region 32 has a plain weave design in which two types of weft yarns are used, and its weave density is about 22 yarns / cm. Nylon 66 yarn having a thickness of 420d is used as the warp yarn, and nylon 66 yarn having a thickness of 420d and rayon yarn having a thickness of 265d are alternately used adjacent to each other for the weft yarn. The first region 30 and the second region 32 are integrally woven as follows. After the first region 30 is woven up by a predetermined amount using nylon 66 yarn as the weft yarn, the second region 32 is woven while weft yarn replacement is performed with the nylon 66 yarn and the rayon yarn. When the required width of the second region 32 (80 mm in this embodiment) has been woven, the first region 30 is woven again using only nylon 66 yarn as the weft yarn.

At the same time as the weaving of the second region 32, the third region 34 is also woven. In the third region 34, the yarns that make up the fabric are the same as the yarns that make up the fabric in the second region 32, but the textures are different, and a portion of the tissue is cut. FIG. 2 conceptually shows an organization chart of the third region 34 and the second region 32 in the vicinity thereof. In the figure, the weft yarns are arranged in the column direction with the reference numerals 1 to 13, and the warp yarns are arranged in the row direction with the symbols a to n. The weave design of the third region 34 is between the warp yarns d to j, and the weave design of the second region 32 is between the warp yarns a to c and k to n. Further, the third region 34 has a complete design surrounded by the warp yarns d to j and the weft yarns 1 to 4. In the third region 34, this complete structure is repeated in the row direction by the same width as the width in the left-right direction of the second region 32 in FIG.

In the third region 34, the odd-numbered weft yarns are composed of rayon yarns, the even-numbered weft yarns are composed of nylon yarns, and the even-numbered nylon yarns cross over the warp yarns from d to j. ing. The even numbered weft threads are cut at the positions of the warp threads g. The metal fibers 36 shown in FIGS. 3 and 4 are woven in the third region 34 along with the warp yarn g shown in FIG. Even numbered weft threads are cut on the woven metal fibers 36. A woven fabric in which only even-numbered weft yarns straddle the metal fibers 36 is formed by weaving the metal fibers 36 supported on a heald that moves independently of the movement of the warp yarns.

FIG. 3 shows the positional relationship between the warp yarns b to l, the metal fibers 36, and the weft yarns 1, 2, 3, 4 in the woven fabric in which the metal fibers 36 are woven. However, the warp yarns b to l extend in a direction perpendicular to the plane of FIG. 3, and the weft yarns 1 to 4 extend in the left-right direction. In addition, "upper" and "lower" in the following description refer to upper and lower sides in the drawing, respectively. The weft thread 1 alternates up and down with each warp thread a to 1, and the metal fiber 36 is on the warp thread g and the weft thread 1. The weft thread 2 straddles the warp threads d to j, and the metal fiber 36 is sandwiched between the warp thread g and the weft thread 2. The weft thread 3 rises and falls irregularly with the warp threads a to l, but is below the warp thread g at the position of the warp thread g, and the metal fiber 36 is above the warp thread g. The weft thread 4 straddles the warp threads d to j, and the metal fiber 36 is sandwiched between the warp thread g and the weft thread 2. Since the weft threads 1 to 4 form one unit in the longitudinal direction of the tissue, the above positional relationship is repeated for the weft threads 5 and thereafter. FIG. 4 shows the positional relationship of FIG. 3 in which the weft threads 1 to 7 are arranged so as to extend in a direction perpendicular to the paper surface.

By weaving the metal fibers 36 as shown in FIGS. 3 and 4, only the even-numbered weft threads are lifted on the metal fibers 36. The even-numbered weft threads that have been lifted are cut by a cutter or the like, the metal fibers 36 are removed, and the third areas 34 are formed.

An air bag is formed by using the airbag bag body 20 of the present embodiment (hereinafter referred to as a device) and a conventional airbag bag body having a vent hole that is open from the beginning (hereinafter referred to as a conventional product). 5 and 6 show the results of comparison of changes in internal pressure when the bag devices are configured and they are inflated. FIG. 5 shows the internal pressure retention after expansion, and FIG. 6 shows the exhaust characteristics when the dummy collides immediately after expansion.

Area A in FIG. 5 is a pressure change when the airbag bag body pushes and breaks the cover pad accommodating the airbag bag body, and there is no difference between the invented product and the conventional product. Area B is the process of inflation of the airbag body, and the invented product has a faster rise in internal pressure than the conventional product. With the devised product, the gas is rarely leaked because the exhaust part was blocked during the expansion process, whereas with the conventional product, gas leaks from the vent hole, which causes such a difference. In the region C, which is the process of decreasing the internal pressure of the airbag after inflation, the invented product has a smaller decrease rate of the internal pressure than the conventional product, and can maintain the internal pressure for a long time. The difference in this case is also due to the fact that the gas leaks from the vent hole in the conventional product, while the gas leaks little in the devised product because the exhaust part is blocked. If the internal pressure rises rapidly and the internal pressure is highly retained as in the case of the device of the present invention, the time during which the internal pressure of the airbag can be kept within a certain range becomes longer, and the timing at which the passenger collides with the airbag The passengers can be effectively protected even if there is a change in the vehicle.

Areas A and B in FIG. 6 are the same as areas A and B in FIG. In FIG. 6, the dummy is collided with the airbag at time t in the area C. Immediately after the damy collision, the exhaust vent opens in the devised product to expel gas, and the conventional product expels gas from the vent hole. At this time, in the case of the conventional product, the internal pressure of the airbag temporarily increased during the collision, but such a phenomenon was not observed in the device of the invention. The opening of the exhaust portion is caused by the breakage of the rayon yarn which is the weft yarn of the third region 34.

Next, a second embodiment is shown in FIG. In the following embodiments, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment. In this embodiment, as in the first embodiment, an occupant-side body cloth 22 and a mounting-side body cloth 24, which are made of a woven fabric, are sewn together. A connection port 26 to the inflator created by the same procedure as the example is provided. The passenger-side main body cloth 22 is the same as the passenger-side main body cloth 24 of the first embodiment. The same material as the passenger-side body cloth 22 is used for the attachment-side body cloth 24, and a rectangular opening 38 (100 mm × 10 mm) is formed in a part of the attachment-side body cloth 24. The opening 38 is covered with a fabric 40 shown in FIG. 8, and the periphery of the fabric 40 is sewn to the attachment-side main body fabric 24 to form an exhaust portion 41.

The woven fabric 40 is cut out in 120 mm increments from an original woven fabric 42 formed into a strip with a width of 50 mm as shown in FIG. 9. The original woven fabric 42 has a warp yarn of 150 d and a weft yarn of 70 d. Composed of polyester yarn. The weaving density is about 47 threads / cm. The woven fabric 40 has a first region 44 and a second region 46 having different weave designs, and in the second region 46, a part of the weft thread is cut.

FIG. 10 shows an organization chart of the second region 46 and the first region 44 in the vicinity thereof. In FIG. 10, as in FIG. 2, a to p indicate warp yarns, and 1 to 9 indicate weft yarns. The second region 46 is a portion between the warp yarns f to l, and the complete structure of the second region 46 is composed of a portion surrounded by the warp yarns f to l and the weft yarns 1 to 4. The weft threads are cut in the same manner as in the first embodiment, and the weft threads 2, 3, 4 in the complete structure are cut.

The change in internal pressure before and after expansion in this embodiment is similar to that in the first embodiment. Until the internal pressure reaches the set value, the opening of the second region 46 of the woven fabric 40 is regulated by the weft yarn 1 of the complete design and the shape of the woven fabric 40 is maintained, but when the internal pressure reaches the set value, the weft yarn 1 breaks. The second region 46 is broken to form an opening in the woven fabric 40, and exhaust is performed.

The third embodiment is shown in FIG. The present embodiment is an airbag bag body 48 for a passenger seat, which is constructed by sewing a main body cloth 50 and a side cloth 52, and the same fabric as that of the second embodiment is provided in the opening 38 of the main body cloth 50. The exhaust unit 41 is configured by attaching 40. The body cloth 50 and the side cloth 52 are made of the same material as in the second embodiment. The change in internal pressure before and after expansion in this embodiment is similar to that in the second embodiment.

As a fourth example, an airbag bag 20 having the same structure as the second example was prepared. As the woven fabric 40 constituting the exhaust part 41, the one having the weave of FIG. 10 was used as in the second embodiment, but all the weft yarns of the woven fabric 40 were 60d rayon yarn, and the weft yarn was cut in the manufacturing process. Did not do. With respect to the change in the internal pressure of the airbag bag 20 when inflated, the same effects as those of the airbag bags of the first to third embodiments were exhibited. The rayon yarn stretched by the internal pressure when the airbag body is inflated breaks when reaching the upper limit set value of the internal pressure, and exhibits the same effect as the first to third embodiments.

FIG. 12 shows a fifth embodiment. In this embodiment, the longitudinal direction of the second region 46 formed in the fabric 40 of the second embodiment is provided so as to coincide with the radial direction of the attachment-side body cloth 24. When the airbag is deployed, the gas flow generated by the inflator causes pulsation on the surface of the airbag bag body 20. The inflator provided in the central portion of the attachment-side main body fabric 24 expands with a waviness phenomenon that progresses in the radial direction, and as a result, the attachment-side main body fabric 24 partially has a large radial pulling force. Receive. Although this tensile force is not directly related to the average internal pressure of the air bag bag, it causes a large radial stress in the local portion of the attachment-side body cloth 24. Therefore, if the longitudinal direction of the second region 46 is the circumferential direction of the attachment-side body cloth 24, the fibers constituting the exhaust part 41 may be broken by the local stress, and the average internal pressure However, the exhaust portion 41 is activated even though the value is still low. On the other hand, if the longitudinal direction of the second region 46 is set so as to coincide with the radial direction of the attachment side body cloth 24 as in the present embodiment, the influence of local stress due to the above pulsation is avoided, The stability of the operation of the exhaust part 41 can be improved by avoiding the early breakage of the fibers forming the exhaust part 41. The exhaust part 41 can be activated only when the average internal pressure reaches the predetermined height and the circumferential stress of the attachment-side body cloth 24 exceeds the set value.

Although some embodiments have been described above, the present invention is not limited to these embodiments. For example, the passenger-side main body cloth 22 and the attachment-side main body cloth 24 of the airbag bag 20 do not have to be plain plain weave fabrics, but have a so-called ripstop structure in which threads of different thicknesses are woven. Or the like, or a film or the like. Further, the weave design of the woven fabric 40 that constitutes the exhaust portion 41 can be set arbitrarily, and even when the weft thread straddles the warp threads, the straddle width is free. Of course, a structure in which the weft thread and the warp thread of this embodiment are interchanged may be used. In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of claims for utility model registration.

[Brief description of drawings]

FIG. 1 is a view showing an outer appearance of a bag body for an airbag which is a first embodiment of the present invention.

FIG. 2 is a structural diagram of a fabric used for an exhaust part of the above-mentioned embodiment.

FIG. 3 is a view conceptually showing a cross section of the woven fabric in a direction parallel to the weft thread.

FIG. 4 is a view conceptually showing a cross section of a portion of the woven fabric having metal fibers in a direction parallel to the warp yarn.

FIG. 5 is a diagram comparing internal pressure holding characteristics of the airbag bag and a conventional airbag bag.

FIG. 6 is a diagram comparing exhaust characteristics of the airbag bag and a conventional airbag bag.

FIG. 7 is a view showing the outer appearance of the airbag bag body according to the second embodiment of the present invention.

FIG. 8 is a view showing a woven fabric used for the exhaust unit of the second embodiment.

FIG. 9 is a view showing an original fabric before the fabric of FIG. 8 is cut out.

FIG. 10 is a schematic diagram of the fabric of FIG.

FIG. 11 is a view showing the outer appearance of an airbag bag body according to a third embodiment of the present invention.

FIG. 12 is a view showing an outer appearance of a bag body for an airbag which is a fifth embodiment of the present invention.

[Explanation of symbols]

 20 Airbag Bag 30 First Area 32 Second Area 34 Third Area 36 Metal Fiber 38 Opening 40 Textile 41 Exhaust Section 44 First Area 46 Second Area 48 Airbag Bag

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuzo Fujii 1-chome Toyota-cho, Kariya city, Aichi Prefecture Toyota Boshoku Co., Ltd. (72) Inventor Akio Amari 1-chome, Toyota-cho, Kariya city Aichi prefecture Incorporated (72) Inventor Noriyuki Horiuchi No. 1 Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. Within

Claims (4)

[Scope of utility model registration request] 1. An airbag bag body having an exhaust part for preventing an excessive rise in internal pressure, wherein the exhaust part is made of a fabric, and the fabric has a lower strength than the other parts of the airbag bag body. A bag body for an air bag characterized by the above. 2. The airbag bag body according to claim 1, wherein at least a part of the threads constituting the woven fabric is made of a material having a lower strength than the other portions. 3. The airbag bag body according to claim 1, wherein a part of the threads constituting the woven fabric is at least partially cut. 4. The portion of the yarn is cut at a portion which continuously crosses over a plurality of adjacent yarns of the yarn orthogonal to the portion of the yarn. The airbag bag according to item 3.