The head-protecting airbag apparatus of the present invention includes an airbag and a guide bracket. The guide bracket includes two guide walls and a joint wall, thereby has a generally U-shaped cross section, and accommodates the folded airbag between the two guide walls. The guide bracket is located above a pillar portion while being covered by an airbag cover, and serves to guide the inflating airbag toward vehicle's inner side and prevent the airbag from entering vehicle's outer side of the pillar garnish. The dimension of a clearance between the two guide walls is set such that: a gap arises between the housed airbag and at least one of the guide walls, thereby the airbag is allowed to inflate in the gap in the initial stage of airbag inflation; and that the deployment direction of the airbag is controlled by the guide walls, toward vehicle's inner side. In the head-protecting airbag apparatus of the present invention, the airbag housed in the upper periphery of windows smoothly protrudes inward of vehicle without providing any gas-leakage preventing means such as a reinforcing patch.

The present application claims priority from Japanese Patent Application No. 2004-369189 of Ochiai, filed on Dec. 21, 2004, the disclosure of which is hereby incorporated into the present application by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a head-protecting airbag apparatus provided with an airbag, which, when fed with inflation gas, is deployable downward from upper edge of side windows of a vehicle to protect occupants' head.

2. Description of Related Art

Conventionally, a head-protecting airbag apparatus is provided with an airbag folded and housed in the upper periphery of windows inclusive of upper part of pillar portions. The housed airbag is covered by an airbag cover, and when fed with inflation gas, inflates to push and open the airbag cover, and deploys downward from the upper periphery of windows. The inflated airbag covers the vehicle's interior side of pillars and windows.

In the prior art, Japanese Patent Laid-Open No. 11-091490 is illustrative of a head-protecting airbag apparatus provided with a jump stand that prevents a deploying airbag from entering the vehicle's outer side of pillar garnish covering the inner side of a pillar portion, such that the airbag smoothly deploys toward inward of vehicle. This jump stand is disposed above, and in vehicle's outer side of, a pillar garnish, and includes a slanted guide face, in the top surface thereof. The jump stand serves to guide an inflating airbag inward of vehicle over the upper end of the pillar garnish, by having the airbag slide on its guide face.

Japanese Patent Laid-Open No. 2002-067860 is illustrative of a head-protecting airbag apparatus provided with a guide bracket. The guide bracket has a U-shaped cross section. The guide bracket includes two guide walls confronting each other, and a joint wall joining the two guide walls at the outer ends of the guide walls, and serves to guide the inflating airbag to predetermined direction inside the vehicle.

This guide bracket accommodates the folded airbag between the two guide walls, and upon airbag deployment, allows the airbag to protrude from an opening provided between the leading ends of the guide walls while controlling the deployment direction of the airbag by the two guide walls. In other words, since the bracket guides the airbag with two guide walls extending from the joint wall, the guide bracket secures more stable airbag protrusion in a predetermined direction in comparison with the jump stand. As a result, upon airbag deployment, the guide bracket prevents the airbag from bumping against or hitching on the pillar garnish, and prevents the airbag from bumping against an airbag cover located above the pillar garnish as well.

However, in the conventional guide bracket, the dimension of a clearance between the two guide walls was so set as to accommodate the folded airbag with no gaps. With this construction, if an output of the inflator for supplying inflation gas to the airbag is great, the airbag inflates rapidly in between the confronting guide walls, which can cause gas leakage. That is, the airbag must be provided with certain gas-leakage preventing means such as reinforcing patch, in a region of the guide bracket and therearound. This has increased manufacturing processes and volume of the airbag.

SUMMARY OF THE INVENTION

The present invention contemplates to solve the above-mentioned problem, and therefore, has an object to provide a head-protecting airbag apparatus which deploys an airbag housed in the upper periphery of windows inward of vehicle smoothly without providing any gas-leakage preventing means, such as reinforcing patch, in a region of the airbag where the guide bracket is located and its vicinity.

The head-protecting airbag apparatus according to the present invention is mounted in the upper periphery of windows inclusive of upper part of a pillar inside the vehicle. The pillar is covered by pillar garnish at vehicle's inner side. The airbag apparatus includes an airbag, an airbag cover and a guide bracket. The airbag is folded and housed in the upper periphery of windows inclusive of upper part of the pillar, and deploys downward therefrom to cover the inner side of the pillar and windows when fed with inflation gas. The airbag cover covers the folded and housed airbag, and is pushed and opened by the airbag upon airbag inflation. The guide bracket is located above the pillar while being covered by the airbag cover.

The guide bracket serves to guide the inflating airbag toward vehicle's inner side while preventing the airbag from entering vehicle's outer side of the pillar garnish. The guide bracket includes two guide walls extending inward of vehicle while confronting each other generally in the vertical direction, and a joint wall joining the two guide walls at the outer ends of the guide walls, thereby has a generally U-shaped cross section. The guide bracket accommodates the folded airbag between the two guide walls, and allows the airbag to protrude inward of vehicle from an opening provided between vehicle's inner side ends of the two guide walls.

The dimension of a clearance between the two guide walls is set so as to leave a gap between the housed airbag and at least one of the guide walls, such that the airbag is allowed to inflate in the gap in the initial stage of airbag inflation. The dimension of the clearance is also set such that the deployment direction of the airbag is controlled by the guide walls, toward vehicle's inner side.

In the head-protecting airbag apparatus according to the present invention, when the airbag is fed with inflation gas, the airbag pushes and opens the airbag cover and deploys downward from the upper periphery of windows, to cover the inner side of windows. Above the pillar, the airbag protrudes inward of vehicle from the opening provided between the two guide walls of the guide bracket.

At this time, the dimension of the clearance between the two guide walls is so set as to allow the airbag to inflate therein in the initial stage of inflation. In other words, the dimension is set such that there arises a gap between the folded and housed airbag and at least one of the guide walls. This construction prevents the airbag from tearing at the location of the guide bracket even without a gas-leakage preventing means such as reinforcing patch. As a result, the airbag is capable of inflating rapidly at the location of the guide bracket. Moreover, the dimension in the guide bracket is set such that the deployment direction of the airbag is controlled by the two guide walls toward vehicle's inner side. Accordingly, guided by the guide bracket, the inflating airbag smoothly protrudes toward vehicle's inner side without unduly bumping against or hitching on the upper end of the pillar garnish or the airbag cover located above the pillar garnish. Consequently, the airbag swiftly deploys to cover the inner side of windows adjacent the pillar portion.

Therefore, in the head-protecting airbag apparatus of the present invention, the airbag housed in the upper periphery of windows smoothly protrudes inward of vehicle without providing any gas leakage preventing means, such as reinforcing patch, in a region of the airbag where the guide bracket is located and its vicinity.

It is desired that the clearance between the two guide walls of the guide bracket gradually enlarges as it heads for vehicle's inner side from the part of the joint wall. With this construction, even if the airbag increases its thickness when protruding inward, it is not held by the two guide walls. Moreover, the guide walls apply inward reaction force to the airbag, so that the airbag protrudes inward even more smoothly in such a manner as to be pushed out by the guide walls.

The airbag may be constructed such that: the airbag includes: a gas admissive portion inflatable with inflation gas to separate a vehicle's inner wall and vehicle's outer wall each thereof; and a gas feed passage, as part of the gas admissive portion, which is disposed along the upper edge of the airbag as completely deployed, as upstream part of inflation gas flown into the gas admissive portion, and supplies the inflation gas in front and rear directions, and that the dimension of the clearance between the two guide walls of the guide bracket is set such that inner surfaces of the two guide walls and the joint wall contact the outer surface of the gas feed passage in the initial stage of airbag inflation.

With this construction, it is the gas feed passage that inflates initially in the air bag. The gas feed passage inflates within the U-shaped guide bracket without leaving no extra gap therein in the initial stage of airbag inflation. Then the airbag is subjected to reaction force from the joint wall and is guided by the two guide walls, and accordingly, protrudes toward vehicle's inner side further smoothly and swiftly. Moreover, the guide bracket controls the deployment direction of the airbag in the initial stage of inflation toward vehicle's inner side with the airbag contacting all the inner surfaces of the two guide walls and the joint wall, but without causing tear in the airbag. Accordingly, the guide bracket is formed compact.

If the airbag includes a protective portion for covering vehicle'sinner side of the windows, as part of the gas admissive portion, below the gas feed passage, the housing of the airbag in the guide bracket is desirably conducted as follows: the gas feed passage is bellows-folded on folds extending in front-rear direction from the state where the vehicle's inner and outer walls of the airbag are overlaid one on the other, thereby provides a bellows-folded portion; the protective portion is roll-folded toward the vehicle's outer wall from the lower edge thereof; and the airbag is housed in the guide bracket in such a manner that the bellows-folded portion is located proximate to an intersection of the guide wall located in upper side and the upper end of the joint wall while locating the roll-folded portion apart from the intersection, such that the roll-folded portion is pushed out of the guide bracket when the bellows-folded portion in the gas feed passage unfolds.

With this construction, since the gas feed passage in the upstream part of inflation gas is bellows-folded, which unfolds easily, the bellows-folded portion swiftly unfolds when fed with inflation gas. Moreover, supported by the joint wall, the bellows-folded portion pushes out the protective portion inward of vehicle along the guide wall located in lower side. Since the protective portion is roll-folded toward the vehicle's outer wall of the airbag from its lower edge, the protective portion or the roll-folded portion unfolds along an occupant and inflates smoothly even if it contacts with the occupant halfway. Consequently, the airbag deploys in a space between occupant's head and the pillar garnish smoothly and swiftly to cover the inner side of the pillar garnish, even if the space is narrow, for example.

In this case, it is desired that the airbag is housed in the guide bracket in such a manner that the airbag is placed on a top surface of the guide wall located in lower side and proximate to an intersection of the lower guide wall and the joint wall. With this construction, when mounting on the vehicle, the folded airbag has only to be placed on the top surface of the lower guide wall while being pressed against the joint wall in the guide bracket. Consequently, the airbag is housed in the guide bracket in a stable manner.

It will also be appreciated that the guide bracket includes, in the front and rear thereof, extended portions where only the joint wall and the lower guide wall extend in the front and rear directions, and that each of the extended portions includes a mounting piece in the upper edge of the joint wall which mounting piece is to be secured to the vehicle body. This construction provides the guide bracket with a configuration where the extended portions to be secured to the vehicle body are located in front and rear of the region having U-shaped cross-section. Therefore, the guide bracket serves to guide the inflating airbag toward vehicle's inner side in a stable manner with the portion having U-shaped section, while being stably fixed to the vehicle.

DESCRIPTION OF PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. However, the invention is not limited to the embodiments disclosed herein. All modifications within the appended claims and equivalents relative thereto are intended to be encompassed in the scope of the claims.

As shown inFIG. 1, the head-protecting airbag apparatus M embodying the present invention includes an airbag20, an inflator12, mounting brackets10and13, a guide bracket40, and an airbag cover8. The airbag20is folded and housed along upper periphery of side windows W1and W2inside the vehicle V, in a range from lower edge part of the front pillar FP to upper side of the rear pillar RP, via lower edge of the roof side rail RR.

As shown inFIG. 1, the inflator12has a substantially cylindrical shape. The inflator12is sheathed with a joint port22of the airbag20for introducing inflation gas, and connected with the airbag20by a clamp15. The inflator12is secured to the inner panel2in the roof side rail RR by a mounting bracket13above the center pillar CP while being covered by the lower edge portion5aof the roof head lining5. The inner panel2is part of the vehicle body1. The mounting bracket13is made of sheet metal, and is secured to the inner panel2by bolts14while holding the inflator12.

As shown inFIG. 9, each of the mounting brackets10consists of two plates of sheet metal. These plates are attached to a mounting portion30of the airbag20from opposite sides. The mounting bracket10is secured to the inner panel2by a mounting bolt11, such that the mounting portion30is secured to the inner panel2. The mounting bolt11is fastened into a nut2bat a mounting hole2ain the inner panel2.

The airbag cover8is composed of the lower edge portion4aof the pillar garnish4arranged in the front pillar FP and the lower edge portion5aof the roof head lining5arranged in the roof side rail RR. The front pillar garnish4and the roof head lining5are made from synthetic resin, and are attached to the vehicle's interior side of the inner panel2in the front pillar FP and the roof side rail RR. The roof head lining5is arranged from upper part of the front pillar FP through upper part of the rear pillar RP, via upper part of the center pillar CP.

Referring toFIGS. 1 to 4, the airbag20is manufactured by hollow-weaving method of polyamide yarn or the like. When fed with inflation gas G from the inflator12, the airbag20is developed from folded state and deploys to cover vehicle's interior side of side windows W1, W2and pillar garnishes7and6at the center pillar CP and the rear pillar RP. The airbag20includes a gas admissive portion21which admits inflation gas G inside to separate its vehicle's inner wall21aand vehicle's outer wall21b,and a non-admissive portion28which admits no inflation gas G.

The non-admissive portion28is formed by joining the walls21aand21bof the admissive portion21, and includes a peripheral portion29, mounting portions30, partitioning portions31and32, and a panel portion33. The peripheral portion29is located in outer edge section of the airbag20and encircles the gas admissive portion21.

Each of the mounting portions30projects upward from the peripheral portion29in the upper edge section20aof the airbag20. In the illustrated embodiment, the airbag20includes six mounting portions30. As best shown inFIG. 2, each of the mounting portions30is provided with a mounting hole30ato insert a bolt11therethrough. As aforedescribed, the mounting bracket10is applied to each of the mounting portions30for attachment to the inner panel2, and the mounting bolt11inserted through the mounting hole30ais fastened into nut2b,thereby the mounting portion30is secured to the inner panel2(refer toFIG. 9).

The panel portion33has a rectangular plate shape, and is located between later-described front and rear protective portions25and26below later-described gas feed passage23. The panel portion33serves to define an entire shape of the airbag20, and also to reduce the volume of the gas admissive portion21so that the time to complete inflation of the airbag20is reduced.

The partitioning portions31and32are located inside front and rear protective portions25and26. The partitioning portions31are formed in such a manner as to enter into the protective portion25or26from the lower edge of the peripheral portion29. The partitioning portion32extends forward and downward from the upper front end of the panel portion33. The partitioning portions31and32serve to regulate thickness of the protective portions25and26as inflated. More specifically, each of the partitioning portions31and32partitions the front and rear protective portions25and26as inflated, respectively, into cells25a,25b,25c,25dand26aand26b,such that the protective portions25and26are inflated flatly, not spherically.

When inflated, the cells25a,25b,25c,25d,26aand26bpartitioned by the partitioning portions31and32serve to reduce the front-rear dimension of the airbag20, such that a tension in the front-rear direction is exerted in the lower edge20bof the airbag20. This tension restrains the completely inflated airbag20from moving outward of vehicle when an occupant moving outward of vehicle contacts the airbag20.

In the specific embodiment, the gas admissive portion21includes a joint port22, a gas feed passage23and a protective portion24. The gas feed passage23extends straightly in the front-rear direction of the vehicle V along the upper edge20aof the airbag20. In a generally longitudinal center of the gas feed passage23is a joint port22extending upward for introducing inflation gas G from the inflator12into the gas admissive portion21. The gas feed passage23supplies inflation gas G from the joint port22both frontward and rearward of the vehicle V, i.e., up to the upper part of the cell25ain the front side, and up to the upper part of the cell26bin the rear side. The gas feed passage23defines the upstream part of inflation gas that inflates firstly in the airbag20. As indicated by double-dotted lines inFIG. 1C, when completely inflated after being mounted on the vehicle, the upper part23aof the gas feed passage (or upstream part)23is covered by the airbag cover8while the lower part23bdeploys up to the side of the upper part of an occupant's head.

The protective portion24serves to protect the occupant's head seated in the vehicle V together with the lower part23bof the gas feed passage23. The protective portion24includes a front protective portion25and a rear protective portion26. The front protective portion25and the rear protective portion26are partitioned in the front-rear direction by the panel portion33. The front protective portion25is arranged below the front part of the gas feed passage23, and is located at the side of front seat of the vehicle V to cover the side window W1located at the side of front seat upon deployment of the airbag20. The rear protective portion26is arranged below the rear part of the gas feed passage23, and is located at the side of rear seat of the vehicle V to cover the side window W2located at the side of rear seat upon airbag deployment. As aforedescribed, the protective portions25and26provide cells25a,25b,25c,25d,26aand26blined up in the front-rear direction of the vehicle upon airbag inflation.

Folding manner of the airbag20is now described. Firstly, the airbag20is flatly developed with the vehicle's inner wall21aand outer wall21boverlaid one on the other. Then the upstream part (gas feed passage)23adjacent the upper edge20aof the airbag20is vertically folded and piled, or bellows-folded on subsequent folds D1and D2, as shown inFIGS. 5A and 5B, so that a bellows-folded portion35is provided along the upper edge20a.

As shown inFIG. 5C, thereafter, the lower part of the airbag20below the bellows-folded portion35is roll-folded toward exterior O of the vehicle from the lower edge20bof the airbag20, so that a roll-folded portion36is provided, and folding work of the airbag20is completed. A not-shown breakable tape member is wound about the folded-up airbag20for keeping the folded-up configuration.

In the embodiment, the guide bracket40, made of sheet metal, is disposed above the rear pillar RP as shown inFIG. 1, and has a generally U-shaped cross-section, as shown inFIGS. 6 to 9. More specifically, the bracket40includes two guide walls46and47which extend inward of vehicle while confronting each other generally in the vertical direction, and a joint wall41joining the guide walls46and47at the outer ends of the walls46and47. The guide bracket40in the embodiment has a generally U-shaped cross-section only in the front vicinity of the longitudinal center portion of the bracket40. In the remaining region, the upper guide wall46is not disposed. That is, in the remaining region other than the region having the U-shaped cross section, only the joint wall41and the lower guide wall47extend in opposite directions in the front-rear direction.

The joint wall41is disposed generally vertically, and includes a main body42, a front extended portion43, and a rear extended portion44. The main body42is positioned in a region of the guide bracket40having the U-shaped cross-section. The front extended portion43extends forward from the main body42, whereas the rear extended portion44extends rearward from the main body42. The front and rear extended portions43and44are shorter than the main body42in height, and are provided with mounting pieces43aand44a, respectively, each of which extends upward partially from the upper edge of the portions43/44. The mounting pieces43aand44ainclude mounting holes43band44b,respectively, which run through the pieces43aand44bin the in-out direction of vehicle. As shown inFIG. 7, the mounting piece43ais secured to the inner panel2by a mounting bolt55. The mounting bolt55is inserted through the mounting hole43b,and fastened into a nut2dattached to a mounting hole2cof the inner panel2. As shown inFIG. 9, the mounting piece44ais secured to the inner panel2by a mounting bolt11, together with the mounting bracket10and the mounting portion30of the airbag20. The mounting bolt11is inserted through the mounting hole44b, and fastened into the nut2dattached to the mounting hole2cof the inner panel2.

The lower guide wall47lies generally along in-out direction of vehicle, and includes a main body48, a front extended portion49, and a rear extended portion50. The main body48is positioned in a region of the guide bracket40having the U-shaped cross section. The front extended portion49extends forward from the main body48, whereas the rear extended portion50extends rearward from the main body48. The lower guide wall47is provided with a bent portion47abent downward from an inner end thereof.

The upper guide wall46extends toward vehicle's inner side I from the upper end of the main body42of the joint wall41in a bent manner.

Sections with reference numerals52shown inFIG. 6designate reinforcing recesses which serve to enhance the rigidity of the guide bracket40, whereas sections with numerals53designate positioning recesses for positioning unillustrated tapes used to mount the bracket40on the airbag20. The tapes are wound around the airbag20so that the bracket40and the airbag20be integral, and are breakable. When mounting the bracket40on the airbag20, the airbag20is accommodated in the vicinity of an intersection C2of the lower guide wall47and the joint wall41. At this mounting time, the inflator12coupled with the mounting bracket13and the mounting brackets10are also assembled with the airbag20, together with the guide bracket40.

In the guide bracket40, dimensions Y1and Y2of a clearance between the upper guide wall46and the main body48of the lower guide wall47are set as follows in consideration of deployment of the airbag20housed between the guide walls46and47. Y1designates the dimension of the clearance between the upper guide wall46and the lower guide wall47in part of the joint wall41, whereas Y2designates the dimension of the clearance between the guide walls46and47in part of open end. The dimensions Y1and Y2are so set as to leave a gap H between the housed airbag20and at least one of the guide walls46and47(the upper guide wall46, in this specific embodiment), in such a manner as to allow the airbag to inflate in the gap H in the initial stage of airbag inflation. The dimensions Y1and Y2are also set such that the deployment direction of the airbag20is controlled by the upper and lower guide walls46and47, i.e., guided toward vehicle's inner side I. Moreover, in the embodiment, the dimensions Y1and Y2are set such that the clearance between the guide walls46and47is gradually enlarged as it heads for vehicle's inner side I from the part of the joint wall41. Additionally, the dimensions Y1and Y2are set such that inner surfaces46a,48aand42aof the guide walls46,47and the joint wall41contact the outer surface of the gas feed passage23of the inflating airbag20.

In the foregoing embodiment, the dimension Y1is 46 mm, Y2is 60 mm, the width X of the lower guide wall47in the in-out direction of vehicle is 32 mm, the dimension L1of the gap H between the folded and housed airbag20and the guide wall46in part of the joint wall41is 14 mm, and the dimension L2of the gap H between the folded and housed airbag20and the guide wall46in part of the open end is 23 mm (refer toFIGS. 6 and 8).

In the guide bracket40, when the mounting pieces43aand44aare bolt55or11fixed to vehicle V, the upper guide wall46lies along generally horizontal direction, and the top surface48aof the lower guide wall47is oriented obliquely downward as it heads for its leading end (or vehicle's inner side I) from its root part (or the joint wall41), such that its extension is oriented above the upper end6aof the pillar garnish6.

To mount the head-protecting airbag apparatus M of the embodiment on the vehicle V, firstly, the airbag20is folded up as described above such that the bellows-folded portion35and the roll-folded portion36are provided. Then the breakable tape members are wound around the airbag20at predetermined positions to keep the folded-up configuration.

Subsequently, the inflator12coupled with the mounting bracket13is connected to the joint port22of the airbag20with the clamp15. Then the mounting brackets10are attached to the mounting portions30of the airbag20.

Thereafter, the airbag20is disposed on the top surface48aof the lower guide wall47in the guide bracket40, in such a manner as to locate the bellows-folded portion35proximate to an intersection C1of the upper guide wall46and the joint wall41while locating the roll-folded portion36apart from the intersection C1, and then housed in the vicinity of the intersection C2of the lower guide wall47and the joint wall41. Then the unillustrated tapes are wrapped at the positioning recesses53, thereby completing an airbag module.

Thereafter, the mounting brackets10,13and40are disposed at predetermined positions of the inner panel2as part of vehicle body1. Then if the brackets10,13and40are secured to the inner panel2by bolt11,14and55fixing through the mounting holes30a,43band44b,the airbag module is mounted on the vehicle body1. Subsequently, an unillustrated lead wire extending from a predetermined control for actuating the inflator is connected to the inflator12. If the front pillar garnish4, the roof head lining5, and then the rear pillar garnish6and the center pillar garnish7are attached to the vehicle body1, the airbag apparatus M is mounted on the vehicle V.

When the inflator12is actuated after mounting of the airbag device M on the vehicle V, inflation gas G discharged from the inflator12flows into the gas feed passage (or the upstream part)23of the airbag20via the joint port22, and flows therein in opposite directions in the front-rear direction, as indicated by double-dotted lines inFIG. 2. Then the gas G enters each of the front and rear protective portions25and26, and the protective portions25and26start to unfold and inflate. The airbag20then breaks the tape member wound therearound, pushes and opens the airbag cover8in the lower edges4aand5aof the front pillar garnish4and the roof head lining5, and inflates to cover the inner side I of the side windows W1and W2, the center pillar CP, and the rear pillar RP while protruding downward, as indicated by double-dotted lines inFIG. 1.

At this time, in the upper side of the rear pillar RP, the airbag20protrudes inward I of vehicle from an opening40aprovided between the two guide walls46and47of the guide bracket40.

At this time, the dimensions Y1and Y2of the clearance between the two guide walls46and47are so set as to allow the airbag20to inflate in the initial stage of inflation. In other words, the dimensions Y1and Y2are set such that there arises a gap H between the folded and housed airbag20and at least one of the guide walls46and47. This construction prevents the airbag20from tearing at the location of the guide bracket40even without any gas-leakage preventing means such as reinforcing patch. As a result, the airbag20is capable of inflating rapidly at the location of the guide bracket40. Moreover, the dimensions Y1and Y2in the guide bracket40are set such that the deployment direction of the airbag20is controlled by the two guide walls46and47toward vehicle's inner side I. Accordingly, the inflating airbag20is smoothly guided along the lower surface46aof the upper guide wall46and the top surface48aof the lower guide wall47, and protrudes toward vehicle's inner side I without unduly bumping against or hitching on the upper end6aof the pillar garnish6or the airbag cover8(or the lower edge5aof the roof head lining5) located above the rear pillar garnish6. Consequently, the airbag20swiftly deploys to cover the inner side I of the side window W2adjacent the rear pillar RP.

Therefore, in the head-protecting airbag apparatus M, the airbag20housed in the upper periphery of the side windows W1and W2smoothly protrudes inward I of vehicle without providing any gas-leakage preventing means, such as reinforcing patch, in a region of the airbag20where the guide bracket40is located.

In the foregoing embodiment, the two guide walls46and47of the guide bracket40are so constructed that the opening width therebetween is gradually widened as it heads for vehicle's inner side I from the part of the joint wall41. With this construction, even if the airbag20increases its thickness when protruding inward I, it is not held by the two guide walls46and47. Moreover, the guide walls46and47applies reaction force acting inward I to the airbag20, so that the airbag20protrudes inward I even more smoothly in such a manner as to be pushed out by the guide walls46and47.

In the foregoing embodiment, the airbag20includes the gas admissive portion21which is inflatable when fed with inflation gas G to separate its vehicle's inner wall21aand vehicle's outer wall21b.The airbag20is also provided, in its upper edge part as completely inflated, with the gas feed passage23that introduces inflation gas G to front and rear directions. The gas feed passage23is the upstream part of inflation gas G flowing into the gas admissive portion21. The dimensions Y1and Y2of the clearance between the guide walls46and47in the guide bracket40are set such that inner surfaces46a,48aand42aof the guide walls46,47and the joint wall41contact the outer surface of the gas feed passage23of the inflating airbag20.

With this construction, it is the gas feed passage23that inflates initially in the airbag20. As shown inFIGS. 10A,10B and10C, the gas feed passage23inflates within the U-shaped guide bracket40while leaving no extra gap therein in the initial stage of inflation of the airbag20. Then the airbag20is subjected to reaction force from the joint wall41and is guided by the guide walls46and47, and accordingly, protrudes toward vehicle's inner side I further smoothly and swiftly. Moreover, the guide bracket40controls the deployment direction of the airbag20in the initial stage of inflation toward vehicle's inner side I with the airbag20contacting all the inner surfaces46a,48aand42aof the guide walls46,47and the joint wall41, but without causing tear in the airbag20. Accordingly, the guide bracket40is formed compact.

In the foregoing embodiment, moreover, the gas admissive portion21of the airbag20includes the protective portion24for covering the vehicle's inner side I of the side windows W1and W2, below the gas feed passage23. The gas feed passage23is formed into the bellows-folded portion35by being bellows-folded on folds D1and D2extending in the front-rear direction from the state where the vehicle's inner and outer walls21aand21bare overlaid one on the other. The protective portion24is formed into the roll-folded portion36by being roll-folded toward the vehicle's outer wall21bfrom the lower edge20b.The airbag20is housed in the guide bracket40so that the roll-folded portion36is pushed out of the guide bracket40when the bellow-folded portion35in the gas feed passage23is unfolded. In other words, the airbag20is housed in the guide bracket40so that the bellows-folded portion35is proximate to the intersection C1of the upper guide wall46and the upper end of the joint wall41, whereas the roll-folded portion36is apart therefrom.

With this construction, since the gas feed passage23as upstream part of the gas G is folded in a bellows fashion, which bellows unfolds easily. Accordingly, the gas feed passage23or the bellows-folded portion35swiftly unfolds when fed with inflation gas G, as shown inFIG. 10A. Moreover, supported by the joint wall41, the bellows-folded portion35pushes out the protective portion24inward I of vehicle along the top surface48aof the guide wall47. Since the protective portion24is roll-folded from its lower edge20b,the portion24or the roll-folded portion36unfolds along an occupant and inflates smoothly even if it contacts with the occupant halfway. Consequently, the rear protective portion26of the airbag20deploys in a space between occupant's head and the pillar garnish6smoothly and swiftly to cover the inner side I of the pillar garnish6, even if the space is narrow, for example.

Without considering the above point, however, the protective portion24located below the bellows-folded portion35may be folded in other folding manner other than roll-folding.

Although the foregoing embodiment has only been described as applied to the guide bracket40disposed in the upper side of the rear pillar RP, the guide bracket40may be disposed in the upper side of other pillars such as the center pillar CP.

In the foregoing embodiment, the folded airbag20is housed in the guide bracket40to provide a gap H between the airbag20and the upper guide wall46. However, the guide bracket40may be constructed to provide a gap between the housed airbag20and the lower guide wall47, or to provide gaps both above and below the housed airbag20.

However, if the construction is made to form the gap H between the airbag20and the upper guide wall46, the airbag20is housed in the guide bracket40on the top surface48aof the lower guide wall47and proximate to the intersection C2of the lower guide wall47and the lower end of the joint wall41. That is, when mounting on the vehicle V, the folded airbag20has only to be placed on the top surface48aof the lower guide wall47while being pressed against the joint wall41in the guide bracket40. Consequently, the airbag20is housed in the guide bracket40in a stable manner.

In the foregoing embodiment, moreover, the guide bracket40includes the extended portions43,44,49and50in front and rear ends thereof, where only the joint wall41and the lower side wall47are extended in front or rear directions. Each of the front and rear extended portions43and44is provided in the upper edge of the joint wall41with the mounting piece43a/44ato be secured to the inner panel2as part of the vehicle body1. This construction provides the guide bracket40with a configuration where the extended portions43and44, which are to be secured to the vehicle body1, are located in front and rear of the region having U-shaped cross-section, i.e., the position of the main bodies42and48, which region is constructed of the upper and lower guide walls46,47and the joint wall41. Therefore, the guide bracket40serves to guide the inflating airbag20toward vehicle's inner side I in a stable manner with the portion having U-shaped cross section, while being stably fixed to the vehicle V.