Air bag

Abstract

To provide an air bag which enables stress applied to a fixed part to be dispersed using a low-cost structure.SOLUTION: An air bag 3 includes: a bag-shaped air bag body 10 that inflates and deploys by introduction of gas therein; a vent hole 20 formed in the air bag body 10; a reinforcement member 22 that is disposed around the vent hole 20 inside the air bag body 10 and is configured to protect the air bag body 10 from gas; a fixing part 33 that is positioned inward of a terminal part 34 of the reinforcement member 22 and is configured to fix the reinforcement member 22 to the air bag body 10; and a gas discharge part 36 that is formed in a region of the reinforcement member 22 extending from the terminal part 34 to the fixing part 33 and allows passage of gas.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an airbag including a reinforcing member disposed around a vent hole of an airbag body portion.

Background Art

[0002] Conventionally, in a vehicle such as an automobile, an airbag that inflates and deploys at the time of an accident or the like to protect an occupant includes a bag-shaped airbag body portion having an opening called a vent hole, and when the occupant comes into contact with the inflated state, a part of the gas is discharged from the vent hole to the outside of the airbag body portion, so that the internal pressure is appropriately maintained. At that time, it is known that a reinforcing cloth (vent patch), which is a reinforcing member for protecting the airbag body portion from gas heat and gas pressure, is provided in the vent hole. The reinforcing cloth is usually fixed to the airbag body portion by a fixing portion such as sewing along the periphery of the vent hole (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the airbag is deployed, gas is blown against the end portion of the reinforcing cloth, causing the end portion of the reinforcing cloth to curl, and stress may be applied to the fixing portion. In order to disperse this stress, increasing the thickness of the reinforcing cloth or increasing the number of sewing threads forming the fixing portion will result in an increase in manufacturing cost and weight.

[0005] The present invention has been made in view of such points, and an object thereof is to provide an airbag capable of dispersing stress applied to a fixing portion with an inexpensive configuration.

Means for Solving the Problems

[0006] The airbag according to an aspect of the present invention includes a bag-shaped airbag body portion that expands and deploys by introducing gas therein, a vent hole formed in the airbag body portion, a reinforcing member disposed around the vent hole inside the airbag body portion for protecting the airbag body portion against gas, a fixing portion located inwardly with respect to an end portion of the reinforcing member for fixing the reinforcing member to the airbag body portion, and a gas venting portion formed in a portion of the reinforcing member from the end portion to the fixing portion for allowing gas to pass through.

Advantages of the Invention

[0007] According to the present invention, the gas that has entered between the airbag body portion and the reinforcing member flows through the gas venting portion and into the vent hole, thereby suppressing the curling between the end portion and the fixing portion of the reinforcing member. Therefore, with an inexpensive configuration, the stress caused by the gas applied to the fixing portion can be dispersed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

[0010] In FIG. 2(b), reference numeral 1 denotes an airbag device. In the present embodiment, the airbag device 1 is attached to a seat in a vehicle compartment of an automobile, which is an attachment part, and expands and deploys between a vehicle door and a window part of a vehicle body, which are opposite to an occupant who is a protected object sitting on the seat, to protect the occupant, thus constituting a so-called side airbag (SAB) device. Note that directions such as front-rear, both sides, and up-down are based on the straight-ahead direction of the automobile. In the figure, the front direction is indicated by arrow FR, the rear direction by arrow RR, the upward direction by arrow U, the downward direction by arrow D, the inside of the vehicle compartment (occupant side) by arrow C, and the outside of the vehicle compartment (vehicle body side) by arrow W.

[0011] The airbag device 1 includes an inflater 2 that generates and injects gas, and an airbag 3 that expands and deploys by the gas supplied by the inflater 2. The inflater 2 is fixed to the airbag 3 by a fixture also called a retainer or the like, and both the inflater 2 and the airbag 3 are housed in a case body and attached to an attachment part such as a seat. The illustrated airbag device 1 is an example for the left seat, and for the right seat, it is basically the same as that for the left seat except that the left and right are reversed.

[0012] In the present embodiment, the inflater 2 has, for example, an elongated shape and is formed in a substantially cylindrical shape in the illustrated example. The inflater 2 is formed with a gas ejection part for supplying gas to the airbag 3. Further, the inflater 2 has a terminal part led out to the outside of the airbag 3 and is electrically connected to a vehicle-side control device, which is a control means such as an in-vehicle control device (ECU), and injects gas from the gas ejection part into the inside of the airbag 3 in response to a signal from the control device. This control device includes a CPU and is connected to one or a plurality of sensors so as to be able to detect the posture and state of the vehicle body and the occupant.

[0013] The airbag 3 shown in FIGS. 2(b) and 3 includes a bag-shaped airbag main body 10. The airbag main body 10 is formed in a flat bag shape in the vehicle width direction, which is the thickness direction, by overlapping and joining a base fabric 11, also called one or a plurality of panels. In the present embodiment, the airbag main body 10 is formed such that, for example, one base fabric 11 is bent from the bent portion 12 at the center, and panel portions 13, 13 formed symmetrically or substantially symmetrically with respect to each other with the bent portion 12 as a reference are overlapped with each other, and the outer edge portions of the panel portions 13, 13 are joined by a joining portion 14 formed by sewing or the like to form a bag shape. In the illustrated example, the airbag main body 10 includes a pair of panel portions 13, 13 in the thickness direction. In the inflated state, one panel portion 13 constitutes a passenger-facing surface facing the side portion of the passenger, and the other panel portion 13 constitutes a vehicle body-facing surface facing the vehicle body side.

[0014] A base portion 15 is formed by the panel portion 13 in the airbag main body 10, which is close to the bent portion 12 and where the joining portion 14 is not located. An inflation portion 16 is formed by the panel portion 13 continuously with the base portion 15.

[0015] The base portion 15 is a gas introduction portion to which the inflator 2 is attached and fixed to the seat. In the present embodiment, the base portion 15 is located at the rear end portion of the airbag main body 10 and extends in the vertical direction. That is, the base portion 15 is formed including the bent portion 12. In the base portion 15, a reinforcing body (reinforcing patch) is fixed inside the airbag main body 10. The reinforcing body is a sheet-shaped reinforcing fabric for reinforcing the base portion 15 against the pressure of the gas from the inflator 2 that inflates the inflation portion 16. The reinforcing body is overlapped and fixed to the panel portion 13 inside the airbag main body 10.

[0016] Further, the inflatable portion 16 is a portion that is inflated by gas introduced from the inflator 2 attached to the base portion 15 into the interior. The inflatable portion 16 is formed to extend further upward and downward with respect to the base portion 15. That is, the inflatable portion 16 is longitudinally long in the vertical direction and expands in the vertical direction toward the front with respect to the base portion 15. In the present embodiment, the length in the vertical direction of the inflatable portion 16 is set so as to expand laterally in a range extending from the shoulders to the waist of the seated occupant in the inflated state.

[0017] The inflation shape of the inflatable portion 16 in the vertical direction is formed such that it gradually becomes larger in the vehicle width direction from the upper joint portion 14 to the lower part and gradually becomes smaller in the vehicle width direction toward the lower joint portion 14. Therefore, the maximum inflation location of the inflatable portion 16 in the thickness direction, that is, the vehicle width direction, is near the central portion in the vertical direction at any position in the front-rear direction.

[0018] In the inflatable portion 16, vent holes 20 are formed in the airbag body portion 10. The vent holes 20 are for appropriately maintaining the internal pressure of the airbag body portion 10 (inflatable portion 16) by discharging a part of the gas injected into the interior of the airbag body portion 10 to the outside of the airbag body portion 10. One or more vent holes 20 are formed. In the present embodiment, two vent holes 20 are formed. In the illustrated example, the vent holes 20 are arranged side by side vertically. The vent holes 20 are formed in a circular shape. For example, the vent hole 20 located on the upper side is set to have a smaller opening area (opening diameter) than the vent hole 20 located on the lower side.

[0019] The vent holes 20 are formed in the outer panel portion 13 on the vehicle outer side in the airbag body portion 10. In the present embodiment, the vent holes 20 are located closer to the upper part than the central portion in the vertical direction of the airbag body portion 10. Further, the vent holes 20 are located at the end portion of the inflatable portion 16 on the side opposite to the base portion 15. That is, the vent holes 20 are located at a position away from the bent portion 12 in the base fabric 11 constituting the airbag body portion 10, and preferably near the outer edge portion of the base fabric 11 joined by the joint portion 14.

[0020] As shown in FIGS. 1(a) and 2(a), inside the airbag body 10, around the vent hole 20, a reinforcing member 22 for protecting the airbag body 10 against the inflation pressure of the gas is arranged. The reinforcing member 22 is also called a reinforcing patch, a vent patch, etc., and it prevents the airbag body 10 from being torn, etc. due to the pressure when gas escapes from the vent hole 20 during the deployment of the airbag body 10 of the airbag 3. The reinforcing member 22 made of a single sheet-like reinforcing cloth or a stack of a plurality of sheet-like reinforcing cloths has an opening 23 communicating with the vent hole 20 formed therein. The opening 23 is formed according to the shape of the vent hole 20. Therefore, in the present embodiment, two circular openings 23 are formed in the reinforcing member 22. Note that the opening 23 is not limited to a hole, but also includes a notch shape or the like.

[0021] The reinforcing member 22 has, for example, a rectangular outer shape. In the present embodiment, the reinforcing member 22 is formed in a rectangular shape and has a first and a second long sides 25, 26 facing each other and a first and a second short sides 27, 28 facing each other. Arc-shaped first and second curved portions 29, 30 are formed on the outer edge from both ends of one long side 25 to the portions continuous with the first and second short sides 27, 28. In the illustrated example, the openings 23 are arranged along one long side 25 and are closer to one long side 25 than the other long side 26 in the short direction of the reinforcing member 22. Further, the openings 23 are arranged concentrically or substantially concentrically with the curved shapes of the first and second curved portions 29, 30.

[0022] The reinforcing member 22 is fixed to the base fabric 11 forming the airbag main body 10 by the fixing portion 33 and is located inside the airbag main body 10 (inflation portion 16). In the illustrated example, the reinforcing member 22 is fixed to the base fabric 11 by the fixing portion 33 with the other long side portion 26 being overlapped with the outer edge portion of the base fabric 11. The fixing portion 33 is formed so as to join the reinforcing member 22 to the base fabric 11 of the airbag main body 10 around the periphery of the vent hole 20. In the present embodiment, the fixing portion 33 is formed in a circular shape or a spiral shape that circulates around a position radially separated from each vent hole 20. The fixing portion 33 is located inside the reinforcing member 22 with respect to one long side portion 25 forming the terminal portion 34 of the reinforcing member 22, one and the other short side portions 27, 28, and one and the other curved portions 29, 30, excluding the portion (the other long side portion 26 in the present embodiment) located at the outer edge portion of the airbag main body 10 in the reinforcing member 22. A part of the fixing portion 33 is close to the curved portions 29, 30. For example, the fixing portion 33 is at a distance of about 7 mm to 10 mm at the shortest with respect to the terminal portion 34. In the illustrated example, the fixing portion 33 is a sewing portion formed by sewing.

[0023] And, a gas vent portion 36 for dispersing the stress applied to the fixing portion 33 by allowing gas to pass through is formed in the reinforcing member 22. The gas vent portion 36 is formed in the sewing margin portion 37 of the reinforcing member 22, that is, the portion from the terminal portion 34 to the fixing portion 33 in the reinforcing member 22. The gas vent portion 36 may have any shape such as an opening or a hole as long as it can allow gas to pass through, but in the present embodiment, it is formed as a slit. In the illustrated example, the gas vent portion 36 is formed in the direction along the terminal portion 34. That is, the gas vent portion 36 is intermittently arranged along a position at a predetermined distance inward from the one short side portion 27, one curved portion 29, one long side portion 25, the other curved portion 30, and the other short side portion 28 forming the terminal portion 34 in the reinforcing member 22.

[0024] For example, in the gas venting portion 36, slits with a length of 5 mm are arranged at intervals of 5 mm. In the present embodiment, the position of the gas venting portion 36 is preferably a position not too close to the fixing portion 33. More preferably, the gas venting portion 36 is at an intermediate position between the fixing portion 33 and the terminal portion 34, for example, at the center of the sewing margin portion 37. That is, the gas venting portion 36 is at an equal distance or substantially equal distance from the terminal portion 34 and the fixing portion 33. Note that the gas venting portion 36 does not need to be set over the entire terminal portion 34 of the reinforcing member 22, and as long as the stress applied to a part of the fixing portion 33 by the gas pressure can be dispersed, it may be in at least the peripheral range of the fixing portion 33 in the sewing margin portion 37.

[0025] In addition, inside the inflatable portion 16, one or more partition walls that partition the inflatable portion 16 into a plurality of chambers and / or a tether or the like, which is one or more regulating members that regulate the inflated shape of the inflatable portion 16, may be set.

[0026] Then, the airbag device 1 is assembled by overlapping and fixing a reinforcing body and a reinforcing member 22 on a base fabric 11, combining an inflator 2 and a fixture and attaching them to the base fabric 11, joining the base fabric 11 by a joining portion 14 to form a bag-shaped airbag 3, and folding the airbag 3 into an appropriate state.

[0027] This airbag device 1 is attached to an automobile seat by being housed in a case as needed, then housed in the side portion of the seat, and fixed to a member such as a seat frame. Further, the terminal portion of the inflator 2 of the airbag device 1 is connected to a control device via, for example, a harness.

[0028] Therefore, when the vehicle is subjected to an impact such as a side collision, based on the sensing signals of each sensor, the control device sends a signal to the terminal portion of the inflator 2 to activate the inflator 2 in a state appropriate for protecting the occupant. In response to this signal, the inflator 2 injects gas from the gas ejection portion. Then, due to the pressure of the gas, as the gas is introduced from the base portion 15 into the inflatable portion 16 and the inflatable portion 16 expands, the airbag 3 pushes open the cover and protrudes from the seat, and expands in the gap between the occupant and the door trim and window portion of the door.

[0029] When the airbag body portion 10 expands and deploys, part of the gas injected from the inflator 2 flows along the surface of the base fabric 11 that constitutes the airbag body portion 10, as shown by the arrow G in FIG. 1(b). Around the vent hole 20, it enters between the sewing margin portion 37 of the reinforcing member 22 and the base fabric 11. In the airbag of the conventional example, since there is no escape path for the gas that enters between the sewing margin portion 37 between the terminal portion 34 and the fixing portion 33 of the reinforcing member 22 and the base fabric 11, it accumulates, and as shown by the two-dot chain line, the sewing margin portion 37 may curl and twist, and there is a risk that a large stress may concentrate on the fixing portion 33.

[0030] On the other hand, in the present embodiment, by forming the gas vent portion 36 that allows gas to pass through the portion from the terminal portion 34 to the fixing portion 33 in the reinforcing member 22, the gas that enters between the airbag body portion 10 and the reinforcing member 22 passes through the gas vent portion 36 and flows into the vent hole 20. Therefore, curling of the sewing margin portion 37 between the terminal portion 34 and the fixing portion 33 is suppressed. Accordingly, it is possible to disperse the stress caused by the gas applied to the fixing portion 33 with an inexpensive and lightweight configuration that does not require further increasing the thickness of the reinforcing member 22 or the number of sheets of the reinforcing member or increasing the number of sewing threads that constitute the fixing portion 33, and it is possible to suppress the concentration of stress caused by the gas on a part of the fixing portion 33.

[0031] And, due to the setting of the gas vent portion 36, the sewing margin portion 37 is less likely to curl, so it is not necessary to form the fixing portion 33 aiming at the edge of the terminal portion 34 of the reinforcing member 22 in order to narrow the sewing margin portion 37, and thus productivity is improved.

[0032] By making the gas vent portion 36 a slit, the gas vent portion 36 can be easily formed, and the required strength of the reinforcing member 22 can be ensured as compared with, for example, the case of forming a large opening.

[0033] In addition, as in the second embodiment shown in FIG. 4, the gas vent portion 36 may be set in a direction intersecting the terminal portion 34 at the terminal portion 34 of the reinforcing member 22. That is, the gas vent portion 36 may be formed in a cut shape in the hemming portion 37 from the terminal portion 34 toward the fixing portion 33. Preferably, the gas vent portion 36 is formed as a slit (vertical slit). At this time, the direction of the gas vent portion 36 may be a direction orthogonal to the terminal portion 34 (the normal direction of the terminal portion 34) as shown in FIG. 4(a), or a direction inclined with respect to the direction orthogonal to the terminal portion 34 as shown in FIG. 4(b), or a combination thereof. Preferably, the gas vent portion 36 is formed to have a length extending from the terminal portion 34 to the central portion of the hemming portion 37. In the illustrated example, a plurality of gas vent portions 36 are arranged at equal intervals or substantially equal intervals.

[0034] In the present embodiment, the gas vent portion 36 is arranged over the entire terminal portion 34. However, as in the first embodiment, it is sufficient that it is in a range where at least the stress applied to a part of the fixing portion 33 by the gas pressure can be dispersed.

[0035] In this way, by having the same configuration as in the first embodiment, such as forming the gas vent portion 36 for allowing gas to pass through the portion from the terminal portion 34 to the fixing portion 33 in the reinforcing member 22, the gas that has entered between the airbag main body portion 10 and the reinforcing member 22 passes through the gas vent portion 36 and flows into the vent hole 20. Therefore, the curling of the hemming portion 37 between the terminal portion 34 and the fixing portion 33 is suppressed, so that it is an inexpensive configuration that does not require further increasing the reinforcing member or increasing the number of sewing threads constituting the fixing portion 33, and the stress due to the gas applied to the fixing portion 33 can be dispersed, and the same operational effects as in the first embodiment can be achieved.

[0036] In each of the above embodiments, for example, when the airbag device 1 is arranged on the front side with respect to the occupant and the airbag 3 is deployed from the front side to the side of the occupant, the same can be achieved by reversing all the arrangements in the front-rear direction.

[0037] Further, the configuration of the gas vent portion 36 can be applied not only to the side airbag but also to any airbag including the vent hole 20 and the reinforcing member 22 that reinforces the periphery thereof.

Industrial Applicability

[0038] The present invention is used, for example, as a so-called side airbag that is housed in the side portion of an automobile seat and deployed to the side of the occupant to protect the occupant.

Explanation of Reference Numerals

[0039] 3 Airbag 10 Airbag main body portion 20 Vent hole 22 Reinforcing member 33 Fixing portion 34 Terminal portion 36 Gas vent portion

Claims

1. An airbag body portion in a bag shape that expands and deploys by introducing gas therein, a vent hole formed in the airbag body portion, a reinforcing member disposed around the vent hole inside the airbag body portion for protecting the airbag body portion against gas, a fixing portion located inwardly with respect to a terminal portion of the reinforcing member for fixing the reinforcing member to the airbag body portion, a gas venting portion formed in a portion from the terminal portion to the fixing portion in the reinforcing member for allowing gas to pass through, and an airbag characterized by comprising the above.

2. The gas venting portion is a slit and the airbag according to Claim 1 is characterized thereby.

3. The gas venting portion is set in a direction along the terminal portion at at least a part between the terminal portion and the fixing portion in the reinforcing member and the airbag according to Claim 2 is characterized thereby.

4. The gas venting portion is set in a direction intersecting the terminal portion at the terminal portion in the reinforcing member and the airbag according to Claim 2 is characterized thereby.

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