JP2008265623A - Airbag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of conventional airbag devices wherein a means for increasing an opening area by rupture is hard to stably obtain the breakage characteristic of a predicted breakage portion, i.e., the connected portions of a foundation cloth connected in a small distance, for example, when an internal pressure rises abruptly and all the connected portions are broken simultaneously, the opening area is maximized suddenly, the opening area is not adjusted according to the lowering of the internal pressure of an airbag thereafter, exhaustion is performed at the maximum rate to the last, and the remaining of the connected portions is broken while leaving partly. <P>SOLUTION: In this airbag device, the airbag 1 has an opening through which a gas is blown to the outside of the gas chamber which is formed in the gas chamber formed in a bag shape by using a flexible sheet body. An extensible membrane is attached to the peripheral edge of the opening. The membrane is disposed to be overlapped with a part of the opening. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an airbag apparatus including an airbag that is mounted on a vehicle or the like and inflates and deploys in the event of a collision or the like.

  Airbags are widely used today as a means for absorbing and mitigating shocks to passengers in vehicle collisions. The airbag is instantly deployed in response to a vehicle collision, etc., and catches the occupant. It is important that the airbag be deployed quickly and smoothly.

As a conventional example, it is used in an airbag device mounted on a boss portion near the center of a ring portion in a steering wheel, and has a wall portion on the boss portion side having a gas inlet for allowing an inflation gas to flow in, A driver side wall, and a boss portion side wall with a vent hole capable of discharging excess inflation gas, and a plurality of linear slits, A slit group formed by being arranged so as to be substantially along a center line centered on the gas inlet is disposed on the side wall of the boss portion, and the slit group is a break between the linear slits. As a configuration for breaking the planned portion to form the vent hole, for the driver, the slit group is disposed so as to be located on the outer side of the ring portion in the airbag when the inflation is completed. air Tsu grayed (e.g., see Patent Document 1) exists.
In this conventional example, for the purpose of quickly and smoothly deploying the airbag, first, the vent hole is not opened carelessly at the initial stage of deployment, and when the vent hole is opened, the inflation gas can be discharged smoothly. It is disclosed. Specifically, it is set as the structure which fractures | ruptures the fracture | rupture planned part which consists of a some linear slit group.
JP 2003-31421 A (refer to the claims section, detailed description section, and FIGS. 1 to 12)

However, in the prior art, it is difficult for the means for increasing the opening area due to breakage to stably obtain breakage characteristics of the portion to be broken, that is, the connecting portion of the base fabric that is finely connected. For example, when the internal pressure rapidly increases, all of the plurality of connecting portions may be disconnected at the same time. In such a case, the opening area suddenly becomes maximum, and the opening area can no longer be adjusted with respect to the subsequent decrease in the internal pressure of the bag. Therefore, exhaust under the fastest condition is performed until the end. The fact that only a part of the plurality of connecting parts is left and only the remaining part is broken is difficult to adjust in practice, regardless of the desk theory.
The present invention solves the above-described problem, and provides an airbag device including an airbag that can change the size of an opening necessary for injecting gas in an initial stage of deployment and a subsequent deployment process. It is for the purpose.

A first invention of the present invention for solving the above-mentioned problems is an airbag device as described in claim 1, and is as follows.
In an airbag device including an inflator that is activated by an activation device and generates gas, and an airbag that is inflated by gas supplied from the inflator, the airbag is formed into a bag shape made of a flexible sheet body. In the formed air chamber, an opening that allows gas to be ejected is formed outside the air chamber, and a stretchable film material is attached to a peripheral portion of the opening, and the film material is formed in a part of the opening. It is the structure arrange | positioned so that it may overlap.

A second invention of the present invention for solving the above-mentioned problems is an airbag device as described in claim 2, which is as follows.
In addition to the first aspect of the present invention, the membrane material has a through hole having a smaller diameter than the opening, and the small diameter through hole overlaps a part of the opening.

A third invention of the present invention for solving the above-described problems is an airbag apparatus as described in claim 3, which is as follows.
In addition to the invention described in claim 2, the through hole is configured to be disposed inside the opening.

A fourth invention of the present invention for solving the above-mentioned problems is an airbag apparatus as described in claim 4, and is as follows.
In addition to the invention described in claim 3, the through hole is configured to be biased inside the opening.

A fifth invention of the present invention for solving the above-mentioned problems is an airbag device as described in claim 5 and is as follows.
In addition to the invention described in any one of claims 2 to 4, the opening is a circular hole.

A sixth invention of the present invention for solving the above-mentioned problems is an airbag device as described in claim 6, and is as follows.
In addition to the invention described in any one of claims 2 to 5, the through hole is a circular hole.

A seventh invention of the present invention for solving the above-mentioned problems is an airbag device as described in claim 7, which is as follows.
In addition to the invention according to any one of claims 2 to 5, the through hole is a cut line.

Since the airbag apparatus according to the present invention has the configuration as described above, the following effects are achieved.
(1) Since the size of the opening necessary for injecting gas can be changed in the initial stage of airbag deployment and the subsequent deployment process, the behavior of airbag deployment can be made constant, and the airbag is inflated. Sometimes even if an occupant is contacted at the initial stage, and gas continues to be injected into the airbag and the pressure inside the airbag becomes extremely high, the gas escapes from the opening and the impact from the airbag on the occupant Can be kept to a minimum and is more secure than prior art airbag devices.
(2) According to claim 1, when the stretchable membrane material has a low gas pressure in the air chamber, the opening area of the opening through which the gas can be ejected is made smaller than the opening area of the opening itself. The effective cross-sectional area of the gas passage is reduced to suppress gas discharge, contributing to the speed and smoothness of airbag deployment.
In addition, since a stretchable membrane material is attached to the flexible sheet body, it is easy for gas to pass when the gas pressure increases, and when the gas pressure is low, the passage of gas can be suppressed, and the gas pressure can be quickly adjusted. To do.
(3) According to claim 2, by forming a through-hole having a smaller diameter than the opening in the membrane material, the gas can easily pass when the gas pressure rises, and the gas passage is suppressed when the gas pressure is low. To do.
In addition, since the stretching stress can be received and dispersed at the periphery of the through-hole, the degree of freedom in shape such as thin film material and high ductility is increased.
(4) According to the third aspect, by arranging the through hole inside the opening, the film material portion in the opening is pushed by the gas flow and deformed into a cross-sectional arch shape, and acts as a guide nozzle. .
(5) According to the fourth aspect of the present invention, by disposing the through hole in the opening, the guide nozzle has a cross section having a different arch shape along the circumferential direction of the opening, and the gas ejection direction is the normal direction. It can also be made to incline with respect to.
(6) According to the fifth and sixth aspects, when one or both of the through holes or the openings are made circular, the edge length is minimized and the opening area is maximized, so that the edges can receive the tension without difficulty. In this case, it is not necessary to strictly reinforce the edge. In addition, the through-hole does not require a distorted opening due to stress concentration and can form a stable gas passage shape, so that it is not necessary to strictly reinforce the edge. Therefore, it is possible to cut out and use a film material having a required characteristic from a film material raw material having a predetermined constant thickness, and it is not necessary to select a complicated and costly manufacturing method such as molding by a dedicated mold, and the cost can be suppressed.

  In an airbag device including an inflator that is activated by an activation device and generates gas, and an airbag that is inflated by gas supplied from the inflator, the airbag is formed into a bag shape made of a flexible sheet body. In the formed air chamber, an opening that is a circular hole that allows gas to be ejected to the outside of the air chamber is formed, and a stretchable film material is attached to a peripheral portion of the opening. The airbag device has a through hole that is a cut line of a circular hole that is biased and arranged inside the opening having a smaller diameter, and is arranged so that the small diameter through hole overlaps a part of the opening.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a partially broken perspective view of an airbag showing an embodiment of the airbag apparatus of the present invention, and FIG. 2 is a partially broken view showing a main part of a vent hole portion showing an embodiment of the airbag apparatus of the present invention. FIG. 3 is a perspective view, FIG. 3 is (a) a schematic cross-sectional view of a vent hole portion in one embodiment of the airbag apparatus of the present invention, (b) a schematic cross-sectional view showing a change in the vent hole when the airbag is deployed, and FIG. FIG. 5 shows an embodiment of the airbag apparatus of the present invention. FIG. 5 is a schematic cross-sectional view showing the main part of a vent hole portion when gas pressure becomes high and gas is released outside the airbag. (A) The schematic front view of the vent hole part which shows what opened the opening of the vent hole by the semicircular membrane sheet | seat initially to the half of the airbag apparatus of one Example of invention, (b) is a membrane with respect to a vent hole Shift the position of the sheet The schematic front view of the vent hole part which shows a thing, (c) is the schematic front view of the vent hole part which shows what offset the through-hole of the membrane sheet from the center to the left direction of a figure, (d) is a strip shape The schematic front view of the vent hole part which shows an example of a membrane sheet, (e) is a schematic front view which shows the modification of the through-hole of a vent hole. FIG. 6 shows one embodiment of the airbag apparatus of the present invention, and is a schematic cross-sectional view showing a laminate of two membrane sheets on the vent hole portion, and a vent hole portion when gas is released from the airbag FIG. 7 is a schematic sectional view showing another embodiment of the airbag device of the present invention, (a) a schematic partially broken perspective view, and (b) a partially cutaway schematic perspective view of a vent hole portion.

First, features of the airbag device of the present invention will be described.
When the stretchable membrane material has a low gas pressure in the air chamber, the opening area of the opening required to eject gas out of the air chamber is reduced, and the effective cross-sectional area of the gas passage is smaller than the opening area of the opening itself. To reduce gas emission and contribute to the speed and smoothness of airbag deployment. Since the stretchable film member is attached to the flexible sheet member, when the sheet member is stretched by the gas from the inflator, the attached film member is stretched together with the sheet member at the portion overlapping the sheet member. Therefore, a portion overlapping the opening of the membrane material is extended, and the effective sectional area of the gas passage is enlarged. At this time, since the gas pressure and the elongation of the film material are proportional, when the gas pressure is increased, the gas easily passes, and when the gas pressure is low, the passage of the gas can be suppressed, and the gas pressure immediately increases and decreases. A gas that tries to pass through a portion overlapping the opening of the membrane material blows, is stretched by the gas flow, and is deformed to enlarge the effective sectional area of the gas passage. Therefore, similarly, due to the proportional relationship between the gas pressure and the elongation of the film material, when the gas pressure increases, the gas easily passes, and when the gas pressure is low, the gas passage can be suppressed, and the gas pressure immediately increases and decreases.

If a through-hole having a smaller diameter than the opening is formed in this membrane material and the through-hole is arranged so as to overlap a part of the opening, the above-mentioned gas pressure rises during the movement of expansion and return of the through-hole. The gas is easy to pass through and acts to suppress the passage of gas when the gas pressure is low. Since the stretching stress can be received and dispersed at the periphery of the through hole, the degree of freedom of the shape such as thin film material and high ductility is increased.
If the through hole is arranged inside the opening, the film material portion in the opening is pushed by the gas flow and deformed into a cross-sectional arch shape, and acts as a guide nozzle, or if it is arranged biased It becomes a guide nozzle having a cross section having a different arch shape along the circumferential direction of the opening, and the gas ejection direction can be inclined with respect to the normal direction.
If one or both of the through holes or openings are circular, their edge lengths are minimized and the opening area is maximized, the edges can be comfortably subjected to tension, and the openings are tightly reinforced In the through hole, a stable gas passage shape can be formed without distorted opening due to stress concentration, and strict reinforcement of the edge portion is not required. Therefore, it is possible to cut out and use a film material having a required characteristic from a film material raw material having a predetermined constant thickness, and it is not necessary to select a complicated and costly manufacturing method such as molding by a dedicated mold, and the cost can be suppressed.

  The attachment means for the membrane material may be selected in consideration of attachment strength with the flexible sheet body, productivity, and the like. When the sheet body is a fabric, means such as sewing a film material and attaching it with an adhesive or an adhesive tape can be selected. In the case where the sheet body is a resin film, adhesion, welding or the like can be performed. The membrane material may be a single sheet such as vulcanized rubber, partially vulcanized rubber, or thermoplastic elastomer, or a composite sheet having a jersey woven fabric as a core material.

Next, the airbag apparatus of this invention is demonstrated based on drawing.
FIG. 1 is a partially broken perspective view of an airbag 1 which is a preferred embodiment of the present invention. A circular upper panel 2 and a lower panel 3 are sewn and joined at outer peripheral portions 21 and 31 to form a bag shape. These two panels are both nylon 66 fabrics. A gas introduction opening 32 into which an upper half portion having a gas injection port of a disc-shaped inflator (not shown) is inserted at the center of the lower panel 3, a donut-shaped reinforcement patch 33 that reinforces the periphery thereof, and the airbag 1. A bolt through hole 34 is formed through which a stud bolt of a fixing plate (not shown) for fixing the bolt to the base plate is inserted.
Two vent holes 35 for discharging the gas generated by the inflator are provided outside the airbag 1 at an intermediate position between the outer peripheral portion 31 of the lower panel 3 and the gas introduction opening 32. The membrane sheet 4 is attached so as to cover the vent hole 35. The membrane sheet 4 on the right side of FIG. 1 is drawn so as to be partially cut away for explanation, so that about half of the vent hole 35 is directly viewed, and actually has a donut shape similar to the membrane sheet 4 on the left side. Various rubbers can be used for the membrane sheet 4, for example, natural rubber, isoprene rubber, synthetic rubber such as butyl rubber, olefin-based elastomer resin, styrene-based elastomer resin, urethane-based elastomer resin, and the like can be selected. it can.

  FIG. 2 is a partially cutaway perspective view showing the main part of the vent hole 35, and a doughnut-shaped thin membrane sheet 4 of about 0.3 to 1.0 mm is shown in the vent hole 35. Overlaid with nylon thread 5 and fixed. The membrane sheet 4 is provided with a through hole 43 having a diameter d0 concentrically formed with a circular outer periphery 42 of a donut-shaped main body 41. The through hole 43 is also concentrically arranged with a vent hole 35 having a diameter D. It has become. Therefore, it can be defined by being divided into a lap portion 44 that is a portion overlapping the lower panel 3 and an overhang portion 45 in the area of the vent hole 35.

Next, the operation of the airbag apparatus of the present invention will be described with reference to the drawings.
When the gas from the inflator enters the airbag 1, the airbag 1 is inflated and deployed. At this time, the membrane sheet 4 does not extend so much as long as the pressure is not increased, and therefore the diameter of the through hole 43 having a diameter smaller than that of the vent hole 35 becomes the exhaust opening diameter, and the amount of gas passing through is not large. . Therefore, the main part of the gas generated by the inflator is used for rapid inflation at the initial stage of deployment of the airbag 1.
Thereafter, when the internal pressure of the airbag 1 increases, the airbag 1 expands greatly and tends to be close to a sphere. Both the upper panel 2 and the lower panel 3 are stretched in the surface direction, and the periphery of the vent hole 35 is also close to a spherical surface. The membrane sheet 4 has a shape close to a spherical surface along the inner surface of the lower panel 3, and the wrap portion 44 provides a reinforcing effect for the lower panel 3 at the peripheral edge of the vent hole 35 (see FIGS. 3 and 4). The overhang portion 45 that does not overlap the lower panel 3 is a portion of the membrane sheet 4 alone, is not constrained to a shape close to the spherical surface of the lower panel 3, and deforms in accordance with the force received by the membrane sheet 4. Therefore, when high pressure gas is discharged, an inclined annular shape (caldera shape) having a diameter d1 is formed as shown by a broken line X in FIG. 4, and when high pressure gas is discharged, as shown by a solid line Y in FIG. It becomes an inclined ring having a large diameter d2 with a large protruding amount, and the opening area for gas passage is widened. At this time, stretching in the direction of the arrow Z is also added, that is, since it is pulled outward by the stretch and tension of the base fabric, a force acts in the direction of shrinking d1 or d2.

Therefore, it becomes possible to raise the area | region until it expands to the maximum diameter at a stretch with a high gas pressure to a higher pressure area. Therefore, the flexible membrane sheet 4 can be applied, and if it is the same hardness rubber, etc., it can be made thin, and if it is the same thickness sheet, a more flexible one can be selected. There is an advantage in that it can be packed in.
By adopting such a configuration, the internal pressure retention capability until the occupant is received is enhanced, and the peak of the internal pressure when the occupant is received does not rebound by exhausting the instantaneous peak pressure, enabling preferable energy absorption. Become.

Next, a modification of the airbag applicable to the airbag apparatus of the present invention will be described with reference to FIGS.
FIG. 5A shows a case where the opening of the vent hole 35 is initially blocked to half by a semicircular membrane sheet 104. The extent to which the vent hole 35 is initially overlapped may be appropriately changed in the adjustment of the exhaust variable characteristic. In this configuration, when there is a portion where the gas flow tends to be deflected in the direction of the arrow Ca and it is desired to reduce the influence of the hot gas, it is preferable to make it other than the direction of the arrow Ca. FIG. 5 (b) shows a configuration in which the position of the membrane sheet 4 with respect to the vent hole 35 is changed using substantially the same components as those of the airbag 1 of FIG. A part of the outer peripheral portion 46 of the circular membrane sheet 4 is also located in the vent hole 35 so that the donut-shaped main body portion 41 crosses the vent hole 35. In this case, the gas is guided in the direction of the arrow Cb similarly to the tendency of FIG. 5A, and the gas is also partially guided in the direction of the arrow Db. FIG. 5C is obtained by eliminating a part of the concentric relationship in FIG. 2 and the like, and by offsetting the through hole 43 of the membrane sheet 304 from the center to the left in the figure. The span between the point of the nylon thread 5 restrained by the lower panel 3 and the edge of the through hole 43 differs in the circumferential direction, that is, changes in the range from the minimum S1 to the maximum S2. Due to the difference in span, the elongation amount of S1 is small and the elongation amount of S2 is large, and the gas is guided so as to be inclined in the direction of the arrow Cc with respect to the normal direction of the drawing. FIG. 5D shows an example of a strip-shaped membrane sheet 404. Gas is guided in the two directions indicated by arrows Cd and Dd with respect to the normal direction of the drawing. In this figure, the opening portion of the vent hole 35 is substantially equal to the left and right, resulting in a V-shaped gas flow. If one of the left and right opening portions is shifted to be larger, one of the two gas flows becomes the main flow, so that the direction in which the main flow is generated can be appropriately adjusted according to the surrounding conditions.

FIG. 5E is a modification of the through-hole, and is not limited to a circular shape, and may be a triangular shape, a quadrangular shape, a polygonal shape, a cross opening 505 shown in the drawing, or the like.
In FIG. 6, a plurality of, for example, two membrane sheets 604 and 605 are overlapped, and the first membrane sheet 604 is soft and the second membrane sheet 605 is hard. In such a configuration, the stretching characteristics of the first membrane sheet 604 are used in a low pressure range, and the stretching characteristics of the second membrane sheet 605 are used in a higher pressure range. The exhaust characteristics can be tuned.
FIG. 7 shows a head protection side airbag 700 in which two adjacent air chambers are partitioned by a partition wall 701 in still another embodiment. The gas generated by the inflator 9 is blown into the inlet port 708 through the conduit 92 connected to the jet outlet 91, and expands the lower cell 703 while flowing toward the front of the vehicle (arrow F) along the first chamber 702. . Reference numeral 707 denotes a tether belt that regulates the thickness of the cell 703 so that the airbag 700 has a generally flat shape. A membrane sheet 704 is overlaid on the partition wall 701 and fixed with an industrial staple 705. The partition wall 701 is provided with a vent hole 735 that is a circular hole having a larger diameter than the through hole 743 of the membrane sheet 704.

Thus, in addition to the application example in the case where one air chamber has a vent hole that opens directly to the outside as in the previous embodiment, a vent hole in which one air chamber opens to the next air chamber. It can also be applied to the vent hole in the case of having. In such a case, gas is first supplied to the upper first chamber 702 that is one of the two adjacent air chambers, and the membrane sheet 704 restricts the flow of gas to the lower chamber 706 that is the other. Then, when the predetermined pressure is reached, the membrane sheet 704 is stretched and deformed into a nozzle shape to change the opening and adjust the pressure so that an appropriate pressure increase and peak suppression of the first chamber 702 can be performed. ing.
Further, since the gas is not directly exhausted outside the airbag 700 and gas is exchanged between the two air chambers, almost all of the internal gas does not escape to the outside in a short time. Therefore, it is suitable for the case of trying to keep the internal pressure at a certain value or longer for some time (several seconds) from the time of collision for the purpose of protecting passengers in rollover.

  It can be used in all of the airbag devices mounted in various automobiles.

1 is a partially broken perspective view of an airbag showing an embodiment of an airbag device of the present invention. It is a partially broken perspective view which shows the principal part of the vent hole part which shows one Example of the airbag apparatus of this invention. It is a schematic sectional drawing of the vent hole part in one example of the airbag device of the present invention. (B) It is a schematic sectional view showing the change of the vent hole at the time of air bag deployment. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view illustrating a main part of a vent hole portion when a gas pressure becomes high and gas is released to the outside of an airbag according to an embodiment of the airbag device of the present invention. (A) The schematic front view of the vent hole part which shows what opened the opening of the vent hole to the half by the semicircular membrane sheet of the Example of the airbag apparatus of this invention, (b) is with respect to a vent hole. A schematic front view of the vent hole portion showing the shifted position of the membrane sheet, (c) is a schematic front view of the vent hole portion showing the membrane sheet through which the through-hole is offset in the left direction of the drawing, (D) is a schematic front view of the vent hole part which shows an example of a strip-shaped membrane sheet, (e) is a schematic front view which shows the modification of the through-hole of a vent hole. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of an airbag apparatus according to the present invention, and is a schematic cross-sectional view showing a laminate of two membrane sheets on a vent hole portion, and a schematic cross-section showing a vent hole portion when gas is released from an airbag. FIG. It is the (a) schematic partial fracture | rupture perspective view which shows the other Example of the airbag apparatus of this invention, (b) The partial notch schematic perspective view of a vent hole part.

Explanation of symbols

1 ... Airbag 104 ... Membrane sheet 2 ... Upper panel 21 ... Outer perimeter
3 .... Lower panel 31 ... Outer peripheral part 32 ... Gas introduction opening 33 ... Reinforcing patch
34 ... Bolt hole 35 ... Vent hole
304 ... Membrane sheet 4 .... Membrane sheet
41... Donut-shaped main body 42...
43 ... Through hole 44 ... Lap part
45 ... Overhang 46 ... Outer periphery
404 ... Membrane sheet 5 ... Nylon thread
505 ... Cross opening 604 ... Membrane sheet
605 ... Membrane sheet 700 ... Side air bag
701 ··· Partition 702 ··· First chamber
703 ... Cell 704 ... Membrane sheet
705 ··· Industrial staple 706 · · · Lower chamber
707 ... Tether belt 708 ... Inlet port
735 ... Vent hole 743 ... Through hole
9 ... Inflator 91 ... Outlet
92 ... Conduit

Claims (7)

In an airbag device including an inflator that is activated by an activation device and generates gas, and an airbag that is inflated by gas supplied from the inflator, the airbag is formed into a bag shape made of a flexible sheet body. In the formed air chamber, an opening that allows gas to be ejected is formed outside the air chamber, and a stretchable film material is attached to a peripheral portion of the opening, and the film material is formed in a part of the opening. An airbag device arranged so as to overlap. 2. The airbag device according to claim 1, wherein the membrane material has a through hole having a smaller diameter than the opening, and the small diameter through hole overlaps a part of the opening. The airbag device according to claim 2, wherein the through hole is disposed inside the opening. The airbag device according to claim 3, wherein the through-hole is biased and disposed inside the opening. The airbag device according to any one of claims 2 to 4, wherein the opening is a circular hole. The airbag device according to any one of claims 2 to 5, wherein the through hole is a circular hole. The airbag device according to any one of claims 2 to 5, wherein the through hole is a cut line.

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