Airbag apparatus

An airbag apparatus includes an airbag that has a first portion and a second portion. The airbag is folded such that the first portion approaches the second portion. The folded airbag has an elongated shape extending along a first direction. An inlet 12a is formed in the airbag 5. By receiving the supply of gas through the inlet 12a, the folded airbag 5 is inflated while being deployed in a second direction perpendicular to the first direction, such that the first portion moves away from the second portion. The inlet 12a is arranged in a part of the folded airbag 5 that is located in a trailing side in the second direction. A first attachment portion 16 is provided in the same part of the folded airbag 5. A second attachment portion 27 is provided in each of the ends of the folded airbag 5. The folded airbag 5 is installed in a ceiling of a vehicle 2 by means of the first attachment portion 16 and the second attachment portions 27. When the airbag 5 is being deployed and inflated, the second attachment portions 27 function to apply an outward tension along the first direction to the airbag 5.

BACKGROUND OF THE INVENTION

The present invention relates to an airbag apparatus.

Airbag apparatuses provided with an airbag having the following configuration have been known. The airbag has a first portion and a second portion, and is folded such that the first portion approaches the second portion. The thus folded airbag has an elongated shape. The airbag has an inlet. When supplied with gas through the inlet, the folded airbag is inflated while being deployed along a predetermined deployment direction, such that the first portion separates from the second portion. The inlet is arranged in a portion of the folded airbag that is located in a trailing side in the deployment direction.

For example, Japanese Laid-Open Patent Publication No. 2004-058849 discloses in paragraphs 0010, 0021 through 0023, and 0029, and FIGS. 3 through 5 a configuration in which a folded airbag having an elongated shape is accommodated between a roof panel and a roof headlining so as to extend in the width of a vehicle. More specifically, the folded airbag is accommodated in a space between rearmost sections of the roof panel and the roof headlining. The roof panel and the roof headlining are bent downward at the rear end of the vehicle, such that the rearmost sections of the roof panel and the roof headlining are substantially parallel to a vertical plane. Attachment portions are provided at an upper portion of the folded airbag. The attachment portions are used to attach the airbag to an inner panel. The inner panel is arranged between the roof panel and the roof headlining and is bent accordingly. In the airbag apparatus disclosed in Japanese Laid-Open Patent Publication No. 2004-058849, gas is supplied from above to the folded airbag, which inflates the airbag while deploying the airbag downward. When deployed and inflated, the airbag intervenes between the rear seats and the rear window.

When the airbag is supplied with gas so that it is deployed and inflated, the momentum of the supplied gas applies a downward urging force, or a force in the deployment direction, to the airbag. However, the airbag is prevented from being displaced downward by the urging force since the airbag is attached to the inner panel at the attachment portions. Further, a tension applying portion extends downward from each end of the folded airbag. The tension applying portions apply outward tension along the width of the vehicle to the airbag. This allows the airbag to be deployed and inflated in a favorable manner from the folded state.

In recent years, to meet the demands for larger spaces of passenger compartments, it has become difficult to secure a space for accommodating a folded airbag in a vehicle rear portion. Therefore, it has become necessary to accommodate a folded airbag in a part closer to the front side of the vehicle, in other words, between sections of the roof panel and the roof headlining that are substantially parallel to the horizontal plane, or in the ceiling of the vehicle. In such a case, an airbag is attached to the inner panel from below. When supplied with gas, an airbag accommodated in the ceiling of a vehicle is inflated while being deployed rearward and downward in the vehicle, so as to intervene between the rear seats and the rear window.

However, in the case where an airbag is accommodated in the ceiling of a vehicle, the desirable deployment and inflation of the airbag are likely to be hindered for the following reasons [1] and [2].

[1] Since the folded airbag is attached to the inner panel from below, the ends of the folded airbag might hang down because of the tension applying portions. When gas is supplied to the airbag in this state, the airbag is inflated while being deployed along an unexpected path.

[2] In the initial stage of the deployment and inflation of the airbag, the airbag receives an urging force due to its own inflation, which urging force acts to pivot the airbag about the attachment portions in a certain direction (for example, forward). If the airbag is pivoted by the urging force, the airbag is inflated while being deployed along an unexpected path.

The above problem that desirable deployment and inflation of an airbag accommodated in the ceiling of a vehicle might be hindered is not unique to airbag apparatuses in which an airbag accommodated in the vehicle ceiling is inflated while being deployed rearward and downward in the vehicle. However, the problem is also found in airbag apparatuses in which an airbag accommodated in the vehicle ceiling is inflated while being deployed outward along the direction of the width of the vehicle.

SUMMARY OF THE INVENTION

Accordingly, it is an objective of the present invention to provide an airbag apparatus that allows an airbag accommodated in the ceiling of a vehicle to be deployed and inflated in a favorable manner.

To achieve the foregoing objective and in accordance with one aspect of the present invention, an airbag apparatus including an airbag is provided. The airbag has a first portion and a second portion. A folded airbag is formed by folding the airbag such that the first portion approaches the second portion. The folded airbag has an elongated shape extending along a first direction. The airbag has an inlet. When receiving supply of gas through the inlet, the folded airbag is inflated while being deployed in a second direction perpendicular to the first direction, such that the first portion moves away from the second portion. In the folded airbag, the inlet is arranged in a trailing position in the second direction, and a first attachment portion is provided in the same position of the folded airbag. A second attachment portion is provided in each of the ends of the folded airbag. The folded airbag is installed in a ceiling of a vehicle from below by means of the first attachment portion and the second attachment portions. When the airbag is being deployed and inflated, the second attachment portions function to apply an outward tension along the first direction to the airbag.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIGS. 1 and 2, an airbag apparatus1according to the present embodiment has an airbag5, which is folded and accommodated in a space in a rear portion of an automobile2. Specifically, the airbag5is accommodated between a roof panel3and a roof headlining4located below the roof panel3, or in the ceiling of the automobile2. The airbag5and the roof headlining4are located above a pair of rear pillars31, which extend vertically in a rear portion of the automobile2. An inflator6for supplying gas to the airbag5is located between the roof panel3and the roof headlining4, at a position in front of the airbag5.

In a rear portion of the automobile2, for example, in a rear bumper7, a sensor8is provided that outputs a signal when an impact greater than or equal to a predetermined value is applied to the rear of the automobile2. Signals from the sensor8are sent to a controller9. When receiving a signal from the sensor8, the controller9outputs an actuation signal to the inflator6. When receiving an actuation signal from the controller9, the inflator6supplies gas to the airbag5. When receiving the gas in this manner, the folded airbag5accommodated in the ceiling of the automobile2is inflated while being deployed rearward in the automobile2, more specifically, toward a space behind rear seats10. After being deployed and inflated, the airbag5is located between the rear seats10and a rear window11as shown by two dot chain lines inFIGS. 1 and 2.

The space between the rear pillars31increases toward its bottom. Accordingly, the space in the rear portion of the passenger compartment19increases in size along the width of the automobile2toward its bottom. To conform to the shape of the space in the rear portion of the passenger compartment19, the deployed and inflated airbag5has a size that increases from the upper end toward the lower end with respect to a direction along the width of the automobile2.

The airbag5will now be described with reference toFIG. 3.

The airbag5is formed by sewing a pair of fabric sheets and has a connection portion12, a lateral inflatable cell13, and left and right vertical inflatable cells14, and a pair of center vertical inflatable cells15. The connection portion12extends upward from the center of the lateral inflatable cell13as viewed inFIG. 3. The connection portion12has an inlet12aand is connected to the inflator6. Each of the left and right vertical inflatable cells14extends downward from one of the ends of the lateral inflatable cell13as viewed inFIG. 3. The center vertical inflatable cells15extend downward from the center of the lateral inflatable cell13as viewed inFIG. 3. The lateral inflatable cell13communicates with each of the connection portion12and the vertical inflatable cells14,15. A section17of the airbag5that is located below the lateral inflatable cell13and between the left vertical inflatable cell14and the center vertical inflatable cells15, and a section17of the airbag5that is located below the lateral inflatable cell13and between the right vertical inflatable cell14and the center vertical inflatable cells15are portions of one of the two fabric sheets and cannot be inflated.

When the airbag5is deployed and inflated, the lateral inflatable cell13extends laterally, more specifically, along the width direction of the automobile2. The left and right vertical inflatable cells14each extend rearward and downward from one of the ends of the lateral inflatable cell13in the automobile2, and are located outward of the headrest10aof the corresponding rear seat10with respect to the width direction of the automobile2. The center vertical inflatable cells15extend rearward and downward in the automobile2from the center of the lateral inflatable cell13and are located between the headrests10a. The non-inflatable sections17are each located behind the corresponding headrest10ato intervene between the headrest10aand the rear window11.

An inner tube18is provided inside the connection portion12and the lateral inflatable cell13of the airbag5. The inner tube18conducts gas from the inflator6along predetermined directions in the airbag5. The inner tube18can be folded together with the airbag5. The folded inner tube18can be unfolded together with the folded airbag5.

A section of the inner tube18that is located in the connection portion12has an opening corresponding to the inlet12a. A section of the inner tube18that is located in the lateral inflatable cell13extends along the direction in which the lateral inflatable cell13extends. An opening18ais formed at each end of the section of the inner tube18located in the lateral inflatable cell13. The openings18aeach correspond to one of the left and right vertical inflatable cells14. Openings18bare formed at a center portion of the section of the inner tube18located in the lateral inflatable cell13. The openings18beach correspond to one of the center vertical inflatable cells15. Gas supplied from the inflator6to the airbag5through the inlet12apasses through the inner tube18and flows into the left and right vertical inflatable cells14via the left and right openings18a, and flows into the center vertical inflatable cells15via the center openings18b.

When accommodating the airbag5between the roof panel3and the roof headlining4, the airbag5is folded to cause a first portion (a lower portion as viewed inFIG. 3) to approach a second portion (an upper portion as viewed inFIG. 3). As a result, when folded, the airbag5has an elongated shape extending along a first direction. By receiving the supply of gas through the inlet12a, the folded airbag5is inflated while being deployed in a second direction perpendicular to the first direction, such that the first portion moves away from the second portion. The inlet12ais arranged in a part of the folded airbag5that is located in a trailing side in the second direction.

Next, a structure for installing the airbag5in the ceiling of the automobile2will be described.

As shown inFIG. 3, a first attachment portion16is provided at the second portion of the airbag5, more specifically, substantially at a center portion of the upper edge of the lateral inflatable cell13. A second attachment portion27is provided at the upper edge of each end of the lateral inflatable cell13. The second attachment portions27allow the folded airbag5to be attached to the ceiling while outward tension along the first direction is applied to the folded airbag5. Each second attachment portion27has a fixation portion29fixed to the ceiling of the automobile2, and a coupling portion28. The coupling portion28has a distal end (a first end) to which the fixation portion29is attached and a proximal end (a second end) attached to the airbag5. The fixation portion29is made of metal and has a rectangular plate-like shape. The coupling portion28is made of fabric including warp and weft. The warp and weft may extend, for example, in the lateral and vertical directions as viewed inFIG. 3, respectively. Alternatively, to improve the elasticity of the coupling portion28, the coupling portion28may be formed of bias woven fabric. In this case, the warp and weft may extend in a direction rotated 45° clockwise from the lateral direction inFIG. 3and in a direction rotated 45° clockwise from the vertical direction inFIG. 3, respectively.

The manner in which the airbag5is accommodated between the roof panel3and the roof headlining4will now be described with reference toFIGS. 4 and 5.

As shown inFIG. 4, the entire surface of the roof panel3that faces the passenger compartment19is covered by the roof headlining4, which is made of a flexible material. The roof panel3and the roof headlining4are generally horizontal, though they-are slightly inclined downward at a rear portion of the automobile2. An inner panel20, which is fixed to the roof panel3, is located between the roof panel3and the roof headlining4. The rear end of the roof panel3(the right end as viewed inFIG. 4) is bent so as to approach the inner panel20and coupled to the rear end of the inner panel20. The rear end of the roof panel3functions as a rear roof rail23for supporting a rear door21. The rear door21is pivotally attached to the rear end of the roof panel3, that is, to the rear roof rail23by means of a hinge mechanism22. The rear door21has the rear window11.

The roof headlining4is attached to the roof panel3so as to be pivotable downward about a part that is in front of a section of the inner panel20attached to the roof panel3(left end as viewed inFIG. 4), for example, about the front end of the roof headlining4. The rear end of the roof headlining4is engaged with an engagement piece24provided at the rear end of the rear roof rail23(alternatively, at the rear end of the roof panel3or the inner panel20). The engagement between the rear end of the roof headlining4and the engagement piece24is cancelled when the roof headlining4is pushed substantially downward.

The folded airbag5and the inflator6are accommodated in a space below the inner panel20and between the roof panel3and the roof headlining4. The airbag5is rearward of the inflator6. The inner panel20is formed to have a high rigidity so as to be hardly deformed when an impact is applied to the automobile2from behind, and the airbag5and the inflator6are attached to the inner panel20. The airbag5is attached to the inner panel20in the following manner. First, the first attachment portion16and the second attachment portions27of the airbag5are placed on the inner panel20from below. Then the first attachment portion16is fixed with a bolt25and a nut26(seeFIG. 4), and the second attachment portions27are fixed with bolts30(seeFIG. 5A).

As described above, the airbag5is folded such that the first portion (the lower portion as viewed inFIG. 3) approaches the second portion (the upper portion as viewed inFIG. 3). More specifically, the first portion is accordion-folded, and the second portion is rolled, so that an elongated folded intermediate is formed. Thereafter, each end of the folded intermediate is accordion-folded at an even number (for example, two) of folding lines. The folding of the airbag5is thus complete. The thus folded airbag5is arranged over the roof headlining4such that folded-back portions38of the airbag5, which are formed by accordion-folding the ends of the folded intermediate, are downward of the remainder of the airbag5. The folded airbag5is bound by means of binding tape (not shown) at positions including the folded-back portions38. Due to the difference in the ways of folding, gas supplied from the inflator6is more likely to flow into the first portion of the airbag5, which is accordion folded, compared to the second portion of the airbag5in the rolled state. On the other hand, the rolled second section of the airbag5is unfolded by rolling on the inclined roof headlining4when the roof headlining4pivots downward.

As shown inFIG. 5A, the roof headlining4is located above upper ends32aof a pair of rear pillar garnishes32located at the side ends of the automobile2in the rear portion of the automobile2. Each of left and right ends4aof the roof headlining4is located outside of the upper end32aof the corresponding rear pillar garnish32with respect to the direction of the width of the automobile2. Since the airbag5has a shape that corresponds to the space in the rear portion of the passenger compartment19, the length of the folded intermediate is greater than the space between the upper ends32aof the rear pillar garnishes32. Therefore, the folded intermediate cannot be accommodated on the roof headlining4as-is. However, since the ends of the folded intermediate are folded back, the folded airbag5has a width less than the space between the upper ends32aof the rear pillar garnishes32, and can be easily accommodated on the roof headlining4.

The second attachment portions27are located at the ends of the folded airbag5. When attaching the airbag5to the inner panel20by means of the second attachment portions27, the coupling portion28of each second attachment portion27is expanded outward in the width direction of the automobile2. As a result, the folded airbag5, which is attached to the inner panel20, contacts the lower surface of the inner panel20. Further, the space between two parts of the inner panel20to which the fixation portions29of the second attachment portions27are attached is slightly greater than the space between the fixation portions29of the airbag5before being attached to the inner panel20. Therefore, the folded airbag5, which is attached to the inner panel20, receives an outward tension along a direction perpendicular to the deployment direction of the airbag5, that is, an outward tension along the first direction. As a result, the ends of the folded airbag5are prevented from hanging down.

In the state where the airbag5is attached to the inner panel20, the direction in which the coupling portion28of each second attachment portion27extends is, as shown inFIG. 5B, coincides with the direction in which the folded airbag5extends, that is, with the first direction, and is perpendicular to the deployment direction of the airbag5(from top to bottom inFIG. 5B), or to the second direction. The distal end of each coupling portion28is joined to the fixation portion29over the entire width of the coupling portion28(or the entire vertical dimension of the coupling portion28as viewed inFIG. 5B). The proximal end of each coupling portion28is joined to one of the ends of the folded airbag5over a width that is greater than or equal to half the width of the folded airbag5(or over a width that is greater than or equal to half the vertical dimension of the folded airbag S as viewed inFIG. 5B).

The folded airbag5, which is accommodated in the ceiling of the automobile2in the above described manner, is deployed and inflated as described below.

When gas is supplied from the inflator6to the airbag5through the inlet12a, the tape binding the airbag5is broken. Then, mostly due to the inflation of the folded-back portions38of the airbag5, a substantially downward pressing force is applied to the roof headlining4. This causes each of the left and right ends4aof the roof headlining4to extend beyond the upper end32aof the corresponding rear pillar garnishes32, and is located downward of the upper end32a. In this manner, the roof headlining4is pivoted downward about the front end of the roof headlining4. As a result, the rolled portion of the airbag5is inflated while being deployed to exit rearward from the space between the roof panel3and the roof headlining4.

When the airbag5is deployed and inflated in this manner, the momentum of the gas supplied from the inflator6through the inlet12aapplies to the airbag5a force acting rearward (rightward as viewed IFIG. 6) of the automobile2. However, the airbag5is prevented from being displaced rearward by the attachment of the airbag5to the inner panel20by means of the first attachment portion16. At the initial stage of the deployment and inflation of the airbag5, the airbag5receives a force represented by arrow Y1inFIG. 6, which acts to pivot the airbag5forward (leftward as viewed inFIG. 6) about the first attachment portion16, due to the own inflation. However, the airbag5is prevented from being pivoted by the attachment of the airbag5to the inner panel20by means of the second attachment portions27.

As described above, the folded airbag5, which is attached to the inner panel20, receives an outward tension the direction of which is perpendicular to the deployment direction of the airbag5. This prevents the ends of the folded airbag5from hanging down. Further, the airbag5is prevented from being pivoted by an urging force that acts on the airbag5in the initial stage of the deployment and inflation of the airbag5to pivot the airbag5about the first attachment portion16. That is, the primary factors that hinder favorable deployment and inflation of the airbag5in the case where the airbag5is accommodated in the ceiling of the automobile2are all eliminated. Thus, the airbag5is inflated while being deployed along a previously assumed path shown, for example, by broken lines inFIG. 6, and is prevented from being inflated while being deployed along an unexpected path shown, for example, by two-dot chain line inFIG. 6.

The above described embodiment has the following advantages.

(1) When attaching the folded airbag5to the inner panel20by means of the second attachment portions27, the coupling portion28of each second attachment portion27is expanded outward in the width direction of the automobile2. As a result, the folded airbag5, which is attached to the inner panel20, receives an outward tension the direction of which is perpendicular to the deployment direction of the airbag5.

This prevents the ends of the folded airbag5from hanging down. Further, an urging force that acts on the airbag5attached to the inner panel20in the initial stage of the deployment and inflation of the airbag5to pivot the airbag5about the first attachment portion16is prevented by the structure in which the airbag5is attached to the inner panel20at the first attachment portion16. Thus, reliable deployment and inflation of the airbag5is not hindered by hanging down of the ends of the folded airbag5and pivoting motion of the airbag5about the first attachment portion16in the initial stage of the deployment and inflation.

(2) The coupling portion28of each second attachment portion27extends perpendicularly to the deployment direction of the airbag5. That is, the tension applied to the airbag5by the coupling portions28is perpendicular to the deployment direction of the airbag5. This further improves the deployment and inflation of the airbag5.

(3) The distal end of each coupling portion28is joined to the fixation portion29over the entire width of the coupling portion28. The proximal end of each coupling portion28is joined to one of the ends of the folded airbag5over a width that is greater than or equal to half the width of the folded airbag5. Thus, the airbag5does not easily separate from the inner panel20, and the ends of the folded airbag5are reliably prevented from hanging down.

(4) Major part of the gas supplied from the inflator6through the inlet12ais guided to the ends of the folded airbag5by the inner tube18. Therefore, the inflation at the ends of the folded airbag5progresses quickly, which tends to pivot the ends about the first attachment portion16. However, since the second attachment portions27are provided at the ends of the folded airbag5, the second attachment portions27reliably prevent the ends from being pivoted about the first attachment portion16.

The above embodiment may be modified as follows.

There are cases where a wiring harness33passes through a space rearward (leading side in the deployment direction) of an airbag5accommodated in the ceiling of an automobile2as shown inFIG. 7. In this case, the airbag5may interfere with the wiring harness33during deployment and inflation, hindering the favorable deployment and inflation of the airbag5. To deal with this problem, a guide member34may be provided that guides the airbag5during deployment and inflation so as to prevent the airbag5from interfering with the wiring harness33. The guide member34may be attached to either of the inner panel20or the airbag5.

As shown inFIG. 8, the coupling portion28of each second attachment portions27may be formed by a part of the fabric sheets that forms the airbag5. In this case, also, the coupling portions28are located at the ends of the folded airbag5as shown inFIG. 9. This structure eliminates the process for attaching the second attachment portions27to the airbag5.

The fixation portion29of each second attachment portions27may be constructed as shown inFIG. 10. The fixation portion29shown inFIG. 10has a bushing41. The bushing41has a base portion42and a projection44projecting from the base portion42. The bushing41is attached to the distal end of the coupling portion28by passing the projection44through a hole43formed in the coupling portion28, such that the base portion42contacts a surface of the coupling portion28opposite to a surface of the coupling portion28that faces the inner panel20. The projection44has an axial hole45that extends along the direction in which the projection44extends. A pair of hooks46are formed opposite wall surfaces of the projection44. The hooks46are elastic so as to approach and separate from each other. A pin47is inserted into the axial hole45of the projection44. An engagement groove49is formed in a distal end (the upper end as viewed inFIG. 10) of the pin47, and an engagement step50is formed in a proximal end (the lower end as viewed inFIG. 10) of the pin47. The engagement groove49and the engagement step50are engageable with an engagement portion48formed on the inner circumferential surface of the axial hole45. A section51of the pin47between the engagement groove49and the engagement step50has a diameter that increases toward the proximal end. A support plate52is fitted about the projection44. The coupling portion28is held between the support plate52and the base portion42. The hooks46of the projection44prevent the support plate52from separating from the projection44.

When attaching the airbag5to the inner panel20using the second attachment portion27with the fixation portion29shown inFIG. 10, the projection44is inserted to a hole53formed in the inner panel20until the hooks46of the projection44pass the hole53. This temporarily fix the fixation portion29to the inner panel20. Thereafter, the pin47is pressed toward the distal end of the projection44with the engagement groove49engaged with the engagement portion48of the axial hole45. Accordingly, the engagement groove49of the pin47is disengaged from the engagement portion48in the axial hole45, and the engagement step50of the pin47is engaged with the engagement portion48. At this time, the section51of the pin47is located between the hooks46, and prevents the hooks46from being deformed to approach each other. Thus, the projection44cannot come off the hole53of the inner panel20, so that the fixation portion29is fixed to the inner panel20. By fixing the fixation portion29to the inner panel20in this manner, the airbag5is attached to the inner panel20. Therefore, when the fixation portion29of each second attachment portion27has the structure shown inFIG. 10, the process for attaching the airbag5to the inner panel20is facilitated.

Instead of or in addition to providing the fixation portion29shown inFIG. 10in each second attachment portions27, the first attachment portion16may have a fixation portion29shown inFIG. 10.

An end of the coupling portion28that is attached to the airbag5, that is, the proximal end of the coupling portion28, may be joined to one of the ends of the folded airbag5over a width less than half the width of the folded airbag5. With respect to the width of the folded airbag5, the proximal end of the coupling portion28may be attached to a part in a half of the folded airbag5located further from the inlet12aor to a part in a half of the folded airbag5located closer to the inlet12a. However, the proximal end of the coupling portion28is preferably attached to the part further from the inlet12a. In the case where the proximal end of the coupling portion28is joined to the airbag5at a width less than half the width of the folded airbag5, the coupling portion28may be formed by a cord.

The coupling portion28of each second attachment portion27does not need to extend perpendicularly to the deployment direction of the airbag5, but may intersect the deployment direction of the airbag5at an angle other than 90°.

The folded airbag5, which is attached to the inner panel20, does not need to receive an outward tension along a direction perpendicular to the deployment direction of the airbag5. For example, the space between two parts of the inner panel20to which the fixation portions29of the second attachment portions27are attached may be equal to the space between the fixation portions29of the airbag5before being attached to the inner panel20. In this case, also, the ends of the folded airbag5are prevented from hanging down. Even if no outward tension in a direction perpendicular to the deployment direction of the airbag5is applied to the folded airbag5in advance, the length of the airbag5in the direction of the width of the automobile2is slightly reduced when the airbag5is inflated. As a result, during the deployment and inflation of the airbag5, an outward tension along a direction perpendicular to the deployment direction of the airbag5is applied to the airbag5. In this case, also, the airbag5is prevented from pivoting about the first attachment portion16in the initial stage of the deployment and inflation.

The first attachment portion16may be omitted. In this case also, since the connection portion12of the airbag5is attached to the inflator6attached to the inner panel20, the airbag5is attached to the inner panel20not only at the second attachment portions27, but also at other portions.

In addition to the first attachment portion16and the second attachment portions27, a third attachment portion for attaching the airbag5to the inner panel20may be provided at a portion of the folded airbag5that is located in a leading side in the deployment direction of the airbag5. The third attachment portion may have a structure as shown inFIGS. 12 to 15.

A third attachment portion61shown inFIGS. 12 to 15extends along the deployment direction of the airbag5from the center of the airbag5with respect to a direction perpendicular to the deployment direction as shown inFIGS. 12 and 13. As shown inFIG. 14, the third attachment portion61is applied from below to a bracket62fixed to the inner panel20, and then attached to the bracket62with a bolt63. The third attachment portion61may have a fixation portion29as shown inFIG. 10. Each of the first attachment portion16and the second attachment portions27shown inFIGS. 12 to 15each may have a fixation portion29shown inFIG. 10.

The self weight of the airbag5applies to the airbag5an urging force that acts to pivot the airbag5forward (leftward as viewed inFIG. 14) about the first attachment portion16, resulting in a pivoting motion of the airbag5indicated by an arrow inFIG. 14. Such pivoting motion is reliably prevented by the third attachment portion61. Also, instead of being flat as shown inFIG. 5, the inner panel20, to which the airbag5is attached, is, for example curved with respect to the direction of the width of the automobile2as shown inFIG. 15in some cases. If the airbag5is attached to the curved inner panel20by means of only the first attachment portion16and the second attachment portions27, a gap can exist between the inner panel20and the airbag5. Such a gap is prevented from being created by attaching the airbag5to the curved inner panel20by means not only of the first attachment portion16and the second attachment portions27, but also of the third attachment portion61.

The number of third attachment portions, which are located in a portion of the folded airbag5located at the leading side in the deployment direction of the airbag5may be one or more. In the case where one third attachment portion is provided, the third attachment portion is preferably located at the center of the airbag5in a direction perpendicular to the deployment direction of the airbag5as shown inFIG. 13. In the case where two or more third attachment portions are provided, the third attachment portions are preferably arranged symmetrically with respect to the center of the airbag5in a direction perpendicular to the deployment direction of the airbag5. The third attachment portions are also preferably located at positions closer to the center of the airbag5in the direction perpendicular to the deployment direction of the airbag5.

The number of the first attachment portion16is not limited to one, but two ore more first attachment portions16may be provided. When a plurality of first attachment portions16are provided, the first attachment portions16are preferably arranged at predetermined intervals, for example, equal intervals, along the direction perpendicular to the deployment direction of the airbag5.

In the illustrated embodiments, the present invention is applied to the airbag apparatus, in which the airbag5accommodated in the ceiling of the automobile2is inflated while being deployed downward and toward the rear of the vehicle. However, the present invention may be applied to an airbag apparatus in which an airbag accommodated in the ceiling of a vehicle is inflated while being deployed outward in the direction of the width of the vehicle. In this case, the folded airbag is accommodated in the vehicle ceiling in a state of extending in the front-rear direction of the vehicle.