JP2005153726A - Air bag and air bag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air bag and an air bag device capable of absorbing the shock sufficiently very much even in the condition that the occupant exists near the air bag device. <P>SOLUTION: The air bag 10 has a rear panel 12r furnished with a first vent hole 16 of normally open type and a second vent hole 18 of expansion shape responsive working type to put the inside and outside of the air bag 10 into communication when the air bag 10 is inflated to an irregular shape. At inflation to the normal shape, the vent hole 18 is closed, and gas flows out only from the vent hole 16. If the occupant has plunged into the air bag 10 at the early stage of inflation and the air bag 10 is inflated to an irregular shape, the second vent hole 18 is put in the open condition, and the gas flows out from both vent holes 16 and 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an airbag and an airbag apparatus installed in a high-speed moving body such as a vehicle. More specifically, the present invention relates to an airbag and an airbag apparatus having an improved configuration of a vent hole that allows gas to flow out from an inflated airbag.

  An airbag such as a driver's seat airbag of an automobile is inflated by gas from an inflator and receives an occupant when a vehicle collides. This airbag is provided with a vent hole, and the gas applied to the occupant in the airbag flows out of the vent hole, so that the impact applied to the occupant is absorbed.

Japanese Patent Application Laid-Open No. 9-142239 discloses a configuration in which the vent hole is closed by a tether belt in the initial stage of inflation to expedite the inflation of the airbag, and the vent hole is opened after the airbag is inflated to a certain extent. An airbag is described.
JP-A-9-142239

  In JP-A-9-142239 described above, when an occupant is in close proximity to the airbag, the airbag with the vent hole closed receives the occupant and is inferior in shock absorbing characteristics.

  An object of the present invention is to provide an airbag and an airbag device that can protect an occupant sufficiently even when the occupant is present in a state close to the airbag device.

  The airbag of the present invention (Claim 1) is an airbag having a vent hole, which is closed or opened when the airbag is inflated into a normal shape, and is opened or opened when the airbag is inflated into an irregular shape. It is characterized by having an expansion shape responsive vent hole.

  The airbag according to a second aspect is characterized in that the airbag according to the first aspect further includes a normally open vent hole that communicates the inside and outside of the airbag regardless of the inflated shape of the airbag.

  The airbag according to claim 3 is the airbag according to claim 1 or 2, wherein the inflatable shape responsive vent hole is provided with a lid member that releases or closes when the airbag is inflated into an irregular shape. It is characterized by being.

  The airbag according to claim 4 is characterized in that, in claim 3, the lid member is provided with a small vent hole having a smaller opening area than the inflatable shape responsive vent hole communicating with the inside and outside of the airbag. It is what.

  The airbag according to claim 5 is characterized in that, in claim 3 or 4, the lid member releases or closes when the airbag is inflated in a lateral direction more than a predetermined value. To do.

  The airbag according to claim 6 is the airbag according to claim 5, wherein the lid member covers one end side of the inflatable shape-responsive vent hole and is coupled to the vicinity of the vent hole so that the coupling can be released, and the other end side is the airbag. When the airbag is inflated in the lateral direction beyond a predetermined level, the connection between the vicinity of the vent hole and the lid member is released, and the inflated shape-responsive vent hole is opened or opened widely. It is characterized by being measured.

  The airbag device of the present invention (Claim 7) includes the airbag of the present invention and an inflator for inflating the airbag.

  In the airbag and the airbag apparatus of the present invention, when the airbag starts inflating in a state where the occupant is in proximity to the airbag apparatus, the airbag receives the occupant at a relatively early stage of inflation of the airbag. In response, the gas pressure in the airbag rises, and the airbag is deployed to the side more quickly than during normal inflation. When the airbag is inflated into an irregular shape in this way, the inflatable shape responsive vent hole is opened or opened to a large degree, and the amount of gas outflow from the airbag via the vent hole is increased. As a result, it is possible to absorb a shock sufficiently even for a passenger close to the airbag. Further, the force with which the airbag presses the occupant toward the rear of the vehicle is reduced.

  In the present invention, a normally open vent hole that communicates between the inside and outside of the airbag may be further provided regardless of the inflated shape of the airbag. In the airbag configured as described above, gas flows out from the normally open vent hole exclusively or mainly when the regular shape is inflated. At the time of non-regular shape expansion, gas quickly flows out from both the normally open vent hole and the expansion shape responsive vent hole.

  In one aspect of the present invention, the inflatable shape-responsive vent hole is provided with a lid member that releases or closes when the airbag is inflated into an irregular shape. By the opening operation of the lid member, the amount of gas flowing out from the expansion shape responsive vent hole is increased.

  The lid member may be provided with a small vent hole having a smaller opening area than the inflatable shape-responsive vent hole communicating with the inside and outside of the airbag. In this case, when the airbag is inflated into a regular shape, the gas in the airbag flows out through the small vent hole. At the time of non-regular shape expansion, the gas quickly flows out through the expansion shape responsive vent hole in which the lid member is released from closing or has a large opening.

  It is desirable that the lid member be released from closing or have a large opening when the airbag is inflated in the lateral direction beyond a predetermined level. The lateral direction is a direction (for example, upward, downward, left, or right direction when viewed from the occupant) that intersects the direction connecting the base end side of the airbag and the occupant. With this configuration, when the airbag is inflated into an irregular shape, the inflatable shape responsive vent hole is opened or has a large opening.

  In this case, one end side of the lid member covers the inflatable shape-responsive vent hole and is coupled to the vicinity of the vent hole so that the coupling can be released, and the other end side is coupled to the center side of the airbag. When the bag is inflated in a lateral direction more than a predetermined amount, the vicinity of the vent hole and the lid member are disconnected, and the inflated shape-responsive vent hole is configured to be opened or opened to a large degree. Is preferred. This configuration is relatively simple, and the expansion shape responsive vent hole is surely opened or has a large opening when the irregular shape is expanded.

  Embodiments of the present invention will be described below with reference to the drawings.

[Configuration of the first embodiment]
1 is a plan view of a rear panel side of an airbag according to an embodiment of the present invention, FIG. 2 is a cross-sectional perspective view taken along the line II-II of FIG. 1, and FIG. FIG. 4 is a cross-sectional view taken along the line III-III in FIG. 1 showing a state in the middle of inflation (first stage), and FIG. 4 is a third figure showing a state in the middle of the airbag being inflated to a normal shape (second stage). FIG. 5 is an overall sectional view when the airbag is inflated into a regular shape, FIG. 6 is a partial sectional view when the airbag is inflated into an irregular shape, and FIG. 7 is an airbag. It is whole sectional drawing when is expanded to irregular shape.

  In this embodiment, the airbag 10 is an automobile driver's seat airbag.

  The airbag 10 includes a bag body 12 formed by sewing the peripheral portions of a substantially circular cloth front panel 12f and rear panel 12r with a thread 12s, the center of the front panel 12f, and the center of the rear panel 12r. The first tether belt 14 is connected to the rear panel 12r, and the normally opened vent hole (hereinafter referred to as "first vent") is always connected to the inside and outside of the airbag 10 regardless of the inflated shape of the airbag 10. 16) and an inflated shape in which the airbag 10 is closed when the airbag 10 is inflated into a normal shape, and is open when the airbag 10 is inflated into a non-regular shape to communicate the inside and outside of the airbag 10. The responsive vent hole (hereinafter sometimes referred to as “second vent hole”) 18 and the airbag 10 are inflated into a regular shape. The can has a lid member 20 for opening the expanded configuration-corresponding vent hole 18 when closing the said expanded configuration-corresponding vent hole 18, expands a non-regular shape.

  In this embodiment, as shown in FIG. 2, the upper and lower portions near the center of the front panel 12f and the rear panel 12r are connected to each other (the vertical direction is the vertical direction in FIG. 1, the same applies hereinafter). Thus, a pair of upper and lower (total of two) first tether belts 14 and 14 are provided. As shown in FIG. 1, a total of two first vent holes 16 are provided on the left half side and the right half side of the upper portion of the rear panel 12r. Further, one second vent hole 18 is provided near the middle in the left-right direction at the top of the rear panel 12r (between the first vent holes 16 and 16) and one near the middle in the left-right direction at the bottom of the rear panel 12r. A total of two are provided. A lid member 20 is provided in each second vent hole 18.

  A reinforcing cloth 22 is attached near the center of the front panel 12f. Reference numeral 22s indicates a thread obtained by sewing the peripheral edge portion of the reinforcing cloth 22 to the front panel 12f. From the upper edge portion and the lower edge portion of the reinforcing cloth 22, an ear-shaped piece 24 for connecting a tether belt is projected, and the tip side of the first tether belt 14 is threaded from the ear-shaped piece 24 by a thread 26. Sewn.

  An inflator engaging opening 28 is provided near the center of the rear panel 12r, and an annular reinforcing cloth 30 is sewn to the periphery of the opening 28 with a thread 30s. Further, an insertion hole 32 is provided around the opening 28 so as to penetrate both the reinforcing cloth 30 and the rear panel 12r. The insertion holes 32 are provided at equal intervals around the opening 28.

  The base end side of each first tether belt 14 is continuous with the upper edge portion or the lower edge portion of the reinforcing cloth 30.

  As shown in FIG. 2, each lid member 20 has a belt-like shape in this embodiment, and one end side is sewn to the peripheral edge portion of each second vent hole 18 of the rear panel 12r with a thread 34, and a midway portion. Is sewn with a thread 36 near the center of the rear panel 12r so that the first tether belt 14 is positioned in the vicinity of the other end, and the other end is reinforced with a thread 26 together with the distal end of each first tether belt 14. It is sewn to the ear-shaped piece 24 of the cloth 22.

  The one end side of each lid member 20 is folded back toward the rear panel 12r, and the folded portion constitutes a lid portion 20a that closes the second vent hole 18. The lid portion 20 a is applied to the rear panel 12 r so as to cover the second vent hole 18, and is sewn to the peripheral portion of the second vent hole 18 with a thread 34. The sewing of the lid portion 20a by the thread 34 is formed over the entire circumference of the peripheral edge portion of the second vent hole 18.

  A portion of the belt-like lid member 20 between the other end side (thread 26) and the middle part (thread 36) is a second tether belt that connects the vicinity of the center of the front panel 12f and the vicinity of the center of the rear panel 12r. 38, and a portion between the intermediate portion (thread 36) and the lid portion 20a constitutes a third tether belt 40 that connects the vicinity of the center of the rear panel 12r and the peripheral portion of the second vent hole 18. Yes.

  The length of the second tether belt 38 in the tensioned state is smaller than the length of the first tether belt 14 in the tensioned state. For this reason, when the airbag 10 is inflated, the second tether belt 38 is first placed in front of the first tether belt 14 as the front panel 12f inflates toward the occupant side while being separated from the rear panel 12r. The panel 12f and the rear panel 12r are in a tensioned state.

  Further, the length of the third tether belt 40 in a tensioned state is such that the peripheral edge of the second vent hole 18 from the vicinity of the center of the rear panel 12r (the place where the thread 36 is sewn) when the rear panel 12r is spread flat. It is smaller than the distance to. For this reason, when the airbag 10 is inflated, the rear panel 12r is expanded laterally (radially) at a portion between the vicinity of the center and the peripheral portion of the second vent hole 18 in the third tether belt 40. Regulated by.

  The intermediate portion of the lid member 20 by the thread 36 is joined to the rear panel 12r when the airbag 10 is about to be inflated into a normal shape (the front panel 12f is separated from the rear panel 12r as the airbag 10 is inflated). When the second tether belt 38 is in a state of being tensioned prior to the first tether belt 40, the front panel 12f continues to be separated from the rear panel 12r while the second tether belt 38 is in tension between the two. When the tension generated in the second tether belt 38 reaches a predetermined value in the case of trying to bulge out), the second tether belt 38 is configured to break.

  On the other hand, the connection between the ends of the lid member 20 and the first tether belt 14 by the thread 26 to the ear-shaped piece 24 is stronger than the connection by the thread 36, and occurs in the second tether belt 38. Even if the tension exceeds the predetermined value, it does not break.

  The connection of the lid 20a to the peripheral edge of the second vent hole 18 by the thread 34 is more fragile than the connection by the thread 36, and the airbag 10 has a shape that expands laterally more than the regular shape. When the airbag 10 is to be inflated to the (non-regular shape) (from the state where the third tether belt 40 restricts the lateral deployment of the rear panel 12r, the airbag 10 is further expanded laterally). When the tension generated in the third tether belt 40 that regulates the lateral expansion of the rear panel 12r reaches a predetermined value in the case of trying to expand mainly in the lateral direction), the coupling by the thread 34 is the thread It breaks in preference to the connection by 36. In this case, when the coupling by the thread 34 is broken, the lid portion 20a is peeled off from the peripheral edge of the second vent hole 18, and the second vent hole 18 is opened.

  In this embodiment, these yarns 26, 34, and 36 are all made of the same material and have the same standard such as thickness and breaking strength. For example, the lid portion 20a is formed with the second vent hole. Only one row of the stitches of the thread 34 to be sewn on the peripheral edge of 18 is formed, and two rows of stitches of the thread 36 to be sewn to the rear panel 12r are formed in the middle of the lid member 20, and the other parts of the lid member 20 are formed. By forming three rows of stitches of the thread 26 for sewing the end side to the ear-shaped piece 24, the respective coupling strengths are made different. In this case, the number of stitches of each thread 26, 34, 36 may be (number of stitches of thread 26)> (number of stitches of thread 36)> (number of stitches of thread 34). The number is not limited to the above.

  The airbag 10 is installed in an airbag device for a driver's seat of an automobile. The airbag apparatus includes a retainer 1 that holds the airbag 10, a presser ring 2 that fixes the airbag 10 to the retainer 1, an inflator 4 that supplies inflation gas to the airbag 10, and the like. I have.

  In the present embodiment, a stud bolt 2 a is provided on the presser ring 2.

  The retainer 1 is provided with an inflator attachment port 1a. Further, a bolt hole 1b through which the stud bolt 2a is inserted is formed in the peripheral portion of the inflator attachment port 1a.

  The inflator 4 is provided with a flange 4a that overlaps with the peripheral edge of the inflator attachment port 1a, and the flange 4a is provided with a bolt hole 4b through which the stud bolt 2a is inserted.

  The airbag 10 is disposed on the retainer 1 such that the inflator engagement opening 28 is concentric with the inflator attachment port 1a of the retainer 1, and the presser ring 2 is further overlapped from above. At this time, the stud bolt 2a is inserted through the insertion hole 32 of the airbag 10, the bolt hole 1b of the retainer 1, and the bolt hole 4b of the flange 4a. Thereafter, the nut 2 b is fastened to the stud bolt 2 a to fix the presser ring 2 to the retainer 1, and the edge of the opening 28 of the airbag 10 is sandwiched between the presser ring 2 and the retainer 1.

  After attaching the airbag 10 and the inflator 4 to the retainer 1 in this manner, the airbag 10 is folded, covered with a module cover (not shown), and the module cover is fixed to the retainer 1 to complete the airbag device.

  This airbag device is installed on a steering wheel of an automobile (only the rim portion R is shown in FIGS. 5 and 7).

  Next, the operation of the airbag apparatus provided with the airbag 10 will be described.

  When a frontal collision of the automobile is detected, the inflator 4 is operated to eject gas. Due to the gas from the inflator 4, the airbag 10 starts to inflate and bulges forward of the occupant while pushing open the module cover.

[Operation during in-position]
As shown in FIG. 5, when a passenger is seated in a normal seating position (posture) with respect to the seat at the time of a vehicle collision (hereinafter, such a case is referred to as “in-position”). There is a sufficient space between the occupant-facing surface (front panel 12f) of the airbag 10 and the occupant.

  In this case, in the initial stage of inflation of the airbag 10, first, as shown in FIG. 3, the second tether belt 38, which is shorter than the first tether belt 14, has the air bag 10 prior to the first tether belt 14. The bag 10 is inflated until it is in a tight state between the front panel 12f and the rear panel 12r. In the state of FIG. 3, the front panel 12f is fastened by the second tether belt 38, and is closer to the front (rear panel 12r side) than when the airbag 10 is inflated to the normal shape. positioned.

  In FIG. 3, the third tether belt 40 is in a state of being developed laterally between the vicinity of the center and the peripheral portion of the second vent hole 18 until the third tether belt 40 becomes taut. The rear panel 12r is in a state where slack remains in the portion between the yarn 24 and the yarn 36.

  When the occupant is in the normal position, the airbag 10 is further expanded from the state shown in FIG. 3 toward the occupant side before the occupant enters the airbag 10. At this time, as shown in FIG. 4, the coupling between the second tether belt 38 and the rear panel 12r by the thread 36 is broken, the restriction by the second tether belt 38 is released, and the front panel 12f is further moved to the passenger side. Bulge out. The front panel 12f is separated from the rear panel 12r until the first tether belt 14 is taut. Further, by the breakage of the coupling by the thread 36, the restriction by the third tether belt 40 is released, and the rear panel 12r further expands to the side. As a result, the airbag 10 is inflated to a large capacity regular shape as shown in FIG. In this case, there is a slack in the tether belts 38 and 40 constituting the lid member 20, and the second vent hole 18 remains closed by the lid portion 20a.

  When an occupant has pushed into the airbag 10 thus inflated from the normal seating position, the gas inside the airbag 10 flows out of the normally opened first vent hole 16 and is applied to the occupant. Is absorbed.

[Operation during out-of-position]
As shown in FIG. 7, when the occupant is leaning against the steering and is positioned in front of the normal seating position (hereinafter, this case may be referred to as “out-of-position”). When the automobile collides forward, the passenger rushes into the airbag 10 being inflated at an earlier stage than the airbag 10 is expanded to the state shown in FIG. FIGS. 6 and 7 show the state at this time (non-regular shape expansion state).

  In the state shown in FIGS. 6 and 7, the tether belts 14 and 38 are in a slack state, and the connection between the second tether belt 38 and the rear panel 12r by the thread 36 is not released. In this case, the third tether belt 40 is in a tensioned state between the vicinity of the center of the rear panel 12r and the peripheral portion of the second vent hole 18, and a tension exceeding a predetermined value acts on the third tether belt 40, The connection between the lid portion 20a by the thread 34 and the peripheral edge portion of the second vent hole 18 is broken.

  As a result, the restriction by the third tether belt 40 is released, and the rear panel 12r is quickly deployed laterally. Further, the lid portion 20a is pulled toward the center of the rear panel 12r by the third tether belt 40 and is peeled off from the peripheral edge portion of the second vent hole 18, and the second vent hole 18 is opened.

  As a result, the gas inside the airbag 10 quickly flows out from both the normally opened first vent hole 16 and the second vent hole 18, and the impact applied to the occupant is sufficiently reduced. Can be absorbed. Further, the force with which the airbag 10 presses the occupant toward the rear of the vehicle is reduced.

[Description of another aspect]
In the above-described embodiment, the inflation-shape-responsive second vent hole 18 is located near the middle in the left-right direction above the rear panel 12r of the airbag 10 (between the normally-open first vent holes 16 and 16). However, the number and arrangement of the expansion shape responsive vent holes are not limited to this. Another configuration example of the expansion shape responsive vent hole will be described with reference to FIG. FIGS. 8A to 8D are plan views of the rear panel side of the airbag showing another configuration example of the inflation shape responsive vent hole.

  In the airbag 10A shown in FIG. 8 (a), the inflatable shape-responsive second vent hole 18 is located near the middle in the left-right direction at the upper part of the rear panel 12r (the normally opened first vent holes 16, 16 are connected to each other). Only one is provided in between.

  In the airbag 10B of FIG. 8 (b), the inflatable shape-responsive second vent hole 18 is 1 in each of the left half side of the rear panel 12r on the left half side and the right half side on the right side. Two pieces are provided in total.

  In the airbag 10C of FIG. 8C, the inflatable shape-responsive second vent hole 18 is located near the middle in the left-right direction at the upper portion of the rear panel 12r (the normally opened first vent holes 16, 16 are connected to each other). 3), one each at the lower left and lower right.

  In the airbag 10D of FIG. 8 (d), the inflatable shape-responsive second vent hole 18 is located near the middle in the left-right direction at the upper portion of the rear panel 12r (the normally open first vent holes 16, 16 are connected to each other). 4), one in each of the lower part in the middle of the left and right direction, the middle part in the up and down direction in the left part, and the middle part in the up and down direction in the right part.

  In FIGS. 8A to 8D, the same reference numerals as those in FIGS. 1 to 7 denote the same parts.

  When these airbags 10A to 10D are also inflated to a normal shape (in-position), the second vent hole 18 is kept closed, and when inflated at the out-of-position as shown in FIGS. The lid 20a is peeled off, and the second vent hole 18 is opened.

  In the present invention, a thread 34 for sewing one end side (lid portion 20 a) of the lid member 20 to the peripheral portion of the second vent hole 18, and the other end side of the lid member 20 is sewn to the ear-shaped piece 24. The thread 26 and the thread 36 for sewing the middle part of the lid member 20 near the center of the rear panel 12r are preferably made of the same material. This is because, if the yarns 26, 34, 36 are made of the same material, even if the breaking strength of the yarns 26, 34, 36 decreases due to deterioration over time, the relative order of the relative breaking strengths is as follows. This is because it does not change.

  In the above embodiment, as shown in FIG. 9 (c), the yarns 26, 34, and 36 are made of the same material and have the same specifications such as thickness and breaking strength. (Number of stitches of the thread 36)> (number of stitches of the thread 36)> (number of stitches of the thread 34) (bonding strength by the thread 26)> (bonding strength by the thread 36)> Although it is configured to be (bonding strength by the yarn 34), other than this, for example, as shown in FIG. 9 (a), the yarns 26, 34, and 36 are made of the same material. However, by using three types of yarn satisfying (thickness of yarn 26)> (thickness of yarn 36)> (thickness of yarn 34), (binding strength by yarn 26)> (binding by yarn 36) (Strength)> (bonding strength by the thread 34). Further, as shown in FIG. 9 (b), as the threads 26, 34 and 36, threads made of the same material and having the same standard such as thickness and breaking strength are used (sewing pitch of the thread 26). )> (Sewing pitch of the thread 36)> (sewing pitch of the thread 34) by sewing each of the threads 26, 34, and 36, (binding strength by the thread 26)> (bonding by the thread 36) (Strength)> (bonding strength by the thread 34).

  FIG. 10 is a plan view of the rear panel side of an airbag according to another embodiment of the present invention, and FIG. 11 is a diagram of the state shown in FIG. Sectional view along line XI-XI, FIG. 12 is a sectional view of the same part as FIG. 11 showing a state in the middle of expansion of the airbag into a regular shape (second stage), and FIG. It is sectional drawing of the same part as FIG. 11 when expanding to a shape.

  In this embodiment, the rear panel 12r is covered with a lid member 20A when the airbag 10E is inflated into a regular shape, and is fully opened when the airbag 10E is inflated into a non-regular shape. Only a responsive vent hole (hereinafter sometimes referred to as a “large vent hole”) 18A is provided. The rear panel 12r is not provided with a normally open vent hole.

  In this embodiment, as shown in FIG. 10, two large vent holes 18A are provided, one on each of the upper left and upper right sides of the rear panel 12r.

  The lid member 20A has a small vent hole 16A (first to first mentioned above) having a smaller opening area than the large vent hole 18A, which always connects the inside and outside of the airbag 10E to the lid portion 20a regardless of the inflated shape of the airbag 10E. 7 corresponds to the normally-open first vent hole 16 in the embodiment of FIG. 7) except that the lid member 20 has the same configuration.

  The other structure of this airbag 10E and the structure of the airbag apparatus for driver's seats provided with this airbag 10E are the same as that of embodiment of the above-mentioned FIG. 1-7, In FIG. 1 to 7 denote the same parts.

  Next, the operation of the airbag apparatus provided with the airbag 10E will be described.

  The inflation operation of the airbag 10E in the in-position is the same as that of the airbag 10. FIG. 12 is an inflated view during this in-position, and the tether belt 14 is tight. Thereafter, the airbag 10E is inflated laterally until the rear panel 12r is no longer loosened, and is in an inflated state. Even in this inflated state, the lid portion 20a of the lid member 20A remains over the large vent hole 18A, and the inside and outside of the airbag 10E are communicated only by the small vent hole 16A.

  When an in-position occupant has thrust into the inflated airbag 10E, the gas inside the airbag 10E flows out of the normally open small vent hole 16A and the impact applied to the occupant is absorbed.

  In the out-of-position state, if the occupant has pushed into the airbag 10E at an earlier stage than the airbag 10E enters the state shown in FIG. It becomes to expand toward the direction.

  In FIG. 13, the third tether belt 40A is stretched between the vicinity of the center of the rear panel 12r and the peripheral portion of the large vent hole 18A. And the coupling | bonding of the cover part 20a by the thread | yarn 34 and the peripheral part of this large vent hole 18A fractures | ruptures, and this rear panel 12r expand | deploys rapidly toward a side. The lid 20a is pulled toward the center of the rear panel 12r by the third tether belt 40A and is peeled off from the peripheral edge of the large vent hole 18A, so that the large vent hole 18A is fully opened.

  Even in the airbag 10E, the large vent hole 18A having a larger opening area than the small vent hole 16A is fully opened when inflated in an irregular shape as described above. The gas inside 10E quickly flows out, and the impact applied to the occupant can be sufficiently absorbed. Further, the pressing force toward the rear of the vehicle is reduced.

  In this embodiment, two circular large vent holes 18A are provided, one on each of the upper left and upper right sides of the rear panel 12r of the airbag 10E. The configuration such as the number, arrangement, and shape is not limited to this. Further, the configuration such as the number, arrangement, and shape of the small vent holes 16A may be other than the illustrated one.

  In the above embodiment, the opening areas of the large vent hole 18A and the small vent hole 16A are appropriately selected according to the volume of the airbag, the inflator output, and the like.

  Each of the above embodiments shows an example of the present invention, and the present invention is not limited to each of the above embodiments.

It is a top view by the side of the rear panel of the airbag which concerns on embodiment. It is a cross-sectional perspective view which follows the II-II line | wire of FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing of the same part as FIG. 3 which shows the state in the middle of the airbag of FIG. 1 inflating to a regular shape. FIG. 2 is an overall cross-sectional view when the airbag of FIG. 1 is inflated into a regular shape. It is sectional drawing of the same part as FIG. 3 when the airbag of FIG. 1 expand | swells to an irregular shape. FIG. 2 is an overall cross-sectional view when the airbag of FIG. 1 is inflated into an irregular shape. It is a figure which shows the other structural example of an expansion shape response type | mold vent hole. It is a figure which shows the structure of a thread | yarn. It is a top view by the side of the rear panel of the airbag which concerns on another embodiment. It is sectional drawing which follows the XI-XI line of FIG. It is sectional drawing of the same part as FIG. 11 which shows the state in the middle of the airbag of FIG. 10 inflating to a regular shape. It is sectional drawing of the same part as FIG. 11 when the airbag of FIG. 10 expand | swells to irregular shape.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Retainer 2 Presser ring 4 Inflator 10, 10A, 10B, 10C, 10D, 10E Air bag 12 Air bag main body 14 First tether belt 16 Normally open type (first) vent hole 16A Small vent hole 18 Inflated shape reaction type ( Second) vent hole 18A Large vent hole 20, 20A Lid member 20a Lid part 26, 34, 36 Thread 38 Second tether belt 40 Third tether belt

Claims (7)

In an airbag having a vent hole,
An air that is provided with an inflatable shape-responsive vent hole that is closed or opened when the airbag is inflated into a regular shape and opened or opened when the airbag is inflated into a non-regular shape. bag.   2. The airbag according to claim 1, further comprising a normally open vent hole that communicates between the inside and outside of the airbag regardless of the inflated shape of the airbag.   3. The lid member according to claim 1 or 2, wherein the inflatable shape responsive vent hole is provided with a lid member that releases or closes when the airbag is inflated into an irregular shape. Airbag.   4. The airbag according to claim 3, wherein the lid member is provided with a small vent hole having a smaller opening area than the inflatable shape responsive vent hole, which communicates the inside and outside of the airbag.   The airbag according to claim 3 or 4, wherein the lid member releases the closure or has a large opening when the airbag is inflated in a lateral direction more than a predetermined amount.   6. The lid member according to claim 5, wherein one end side of the lid member covers the inflatable shape-responsive vent hole and is coupled to the vicinity of the vent hole so that the coupling can be released, and the other end side is coupled to the center side of the airbag. When the airbag is inflated in a lateral direction more than a predetermined amount, the connection between the vicinity of the vent hole and the lid member is released, and the inflated shape-responsive vent hole is opened or opened to a large degree. Air bag to do.   An airbag device comprising: the airbag according to any one of claims 1 to 6; and an inflator for inflating the airbag.

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