Side airbag system

Abstract

Side airbag device comprising: a gas generator (31) arranged or to be arranged near one side of an occupant (P) seated in a vehicle seat (12) and which emits filling gas in response to a shock exerted from a lateral direction of a vehicle (10), and an airbag (40) housed in a storage form shaped by folds and deployed or inflated by the filling gas between an area extending from a chest area (PT) to the head (PH) of the occupant (P) and a side wall (11) of the vehicle (10), wherein the airbag (40) is folded in a process of folding the airbag (40) into the storage form from a front to a back, such that the airbag (40) has an intermediate elongated shape extending from the gas generator (31) in a substantially upward direction,where an end near the gas generator (31) is a proximal section (62) and an end farther from the gas generator (31) is a distal section (63), the airbag (40) of the intermediate shape obtains the storage shape by folding back a part of the airbag (40) that is closer than a fold line (64) of the proximal side, which is positioned between the proximal section (62) and the distal section (63), to the distal section (63) in a downward direction along the fold line (64) of the proximal side and by folding back a part of the airbag (40) that is closer than a fold line (66) of the distal side, which is positioned between the fold line (64) of the proximal side and the distal section (63), to the distal section (63) in an upward direction at least along the fold line (66) of the distal side,and the airbag (40) of the storage mold is provided with a release delay section (67) for delaying the timing of the release of a folded-back state of a region between the distal section (63) and the fold line (66) of the distal side; wherein in the airbag (40) of the storage mold, a region between the distal section (63) and the fold line (66) of the distal side is a first region (Z1) and a region between the fold line (64) of the proximal side and the fold line (66) of the distal side is a second region (Z2), and the release delay section (67) is formed by a connecting section (67; 75) that connects the first region (Z1) and the second region (Z2) in a folded-back state along the fold line (66) of the distal side and releases the connecting state according to the inflow of the filling gas into the first region (Z1).

Description

The present invention relates to a side airbag device that inflates and deploys an airbag in a space between an occupant seated in a vehicle seat and a side wall of the vehicle when an impact is applied to the vehicle from a lateral direction due to a side collision or the like, thereby protecting a region extending from a chest region to the head of the occupant from the impact.A side airbag device including an airbag and a inflator is widely known as a device capable of protecting an upper body of an occupant seated in a vehicle seat from an impact caused by a side collision or the like. The airbag in the side airbag device is folded to form a storage shape and accommodated in a seat back (seat back) of the vehicle seat together with a inflator. When an impact is applied to a side wall, for example, a side door, of the vehicle from a lateral direction due to the side collision or the like, inflation gas is supplied from the inflator to the airbag. The airbag is deployed and inflated so as to jump out of the vehicle seat in a state where a portion of the airbag remains in the seat back. Thereafter, the airbag is deployed and inflated in a narrow space between the upper body of the occupant and the side wall of the vehicle. The airbag is interposed between the occupant and the side wall moving toward an inner side of a vehicle compartment to restrain the upper body of the occupant while absorbing the impact applied to the upper body via the side wall.An aspect of such a side airbag device is disclosed in JP 2007-203 939 A. In the side airbag device, the airbag of the storage shape is disposed together with the inflator in the vicinity of the side of the occupant in the seat back. The airbag is folded in the process of folding the airbag into the storage shape from front to rear, and thus the airbag has an intermediate shape formed in an elongated shape extending in a substantially upward direction from the inflator. In the intermediate-form airbag, an end thereof near the inflator is referred to as a proximal portion, while the end thereof remote from the inflator is referred to as a distal portion. As illustrated in FIG. 18, the intermediate-form airbag 91 is provided with a proximal-side fold line 93 and a distal-side fold line 94 from a proximal portion 91 ato a distal portion 91 b. The part of the intermediate airbag 91 that is closer to the distal portion 91 bthan the proximal side fold line 93 is folded back forward and downward along the proximal side fold line 93. Further, the part of the airbag 91 that is closer to the distal portion 91 bfrom the distal side fold line 94 bis folded back and forth along the distal side fold line 94. By folding back these two portions, the airbag 91 is formed in the storage shape.In the airbag 91 of the storage form, a region between the distal portion 91 band the distal side fold line 94 is a first region Z 1, a region between the proximal side fold line 93 and the distal side fold line 94 is a second region Z 2, and a region between the proximal portion 91 aand the proximal side fold line 93 is a third region Z 3.When the inflation gas is ejected from the inflator in response to the impact caused by the side collision or the like, the inflation gas in the airbag 91 flows from the portion near the inflator 92 to the portion remote from the inflator, i.e., in the order of the third region Z 3, the second region Z 2, and the first region Z 1. By the inflation gas, the airbag 91 is deployed and inflated between the region extending from a chest region PT to a head PH of the occupant P seated in a vehicle seat 95 and the side wall of the vehicle.DE 10 2007 013 101 A1 relates to a side airbag device in which an airbag (airbag) has a plurality of regions which are each separately roll-folded, namely relative to one another in different spatial directions or angular positions. In addition, by overlapping the roll folds in regions, wherein a part of a first roll fold is also rolled up along a second spatial direction and is thereby integrated quasi into the second roll fold, it is achieved that the deployment speed and the deployment directions are determined.DE 20 2004 020 840 U1 describes a side airbag device in which a folding strap is provided, which is provided within the chamber of an airbag and extends through an opening in the airbag fabric arranged opposite, so that the initially unfolded airbag can be gathered or folded together by pulling out the folding strap. The airbag thus gathered can be wrapped by means of the pulled-out folding tape and secured in its folded arrangement. DE 600 18 158 T2 discloses a side airbag system for protecting an occupant in the event of a lateral collision. The system includes a frame of a seat having a mounting plate and an airbag cushion comprised of a first part, a pair of second parts, and pairs of reinforcement parts. The first part has a passage portion with a plurality of openings. The second parts are symmetrically arranged on both sides of the passage portion and sewn to the first part, with reinforcing parts attached to the second parts. The side portions of the first part are sewn to an upper chamber, and the two second parts are sewn to a lower chamber. The upper and lower chambers are partitioned from each other by the passage portion. The system also includes an inflator having a pressure generator, a retaining ring, and a mounting bracket.US 5 944 346 A describes a folding pattern for an airbag. A portion of the airbag that deploys vertically above or below the airbag bracket is folded to be positioned in front of the portion of the airbag that deploys directly in front of the bracket. By this arrangement of the vertically offset portion in front of the remaining portion of the airbag, the deployment time required for positioning the airbag is reduced.US 2012 / 0 242 067 A1 discloses a side airbag device. Before a rib cage protecting portion of an airbag is placed in a storage state, at least a part above a gas supply opening of the rib cage protecting portion is folded along a fold line. This fold line extends through a thickness-limiting section, as a result of which the rib cage protection region is divided into a main protection region and an auxiliary protection region. The inflation gas is supplied from the gas supply port to the main protecting portion, while the auxiliary protecting portion is supplied via the main protecting portion. The thickness limiting portion has an arcuate portion that bulges rearward. This thickness-limiting section is arranged in the rib cage protection region such that the rear end of the arc-shaped part is located in the auxiliary protection region.DE 10 2008 016 094 A1 relates to a side airbag device having an inflator and an airbag. The airbag is accommodated in a vehicle seat and is inflated and deployed by gas from the inflator). In this case, it tears the vehicle seat, exits from it and is deployed between a body side section and the vehicle seat. A controller predicts an imminent side impact and causes the inflator to begin deployment prior to the impact. A deployment control arrangement reduces the initial deployment speed of the airbag at least outside the vehicle seat.In the side airbag device of the related art disclosed in JP 2007-203 939 A, before the third region Z 3 and the second region Z 2 are sufficiently deployed and inflated in the airbag 91, the inflation gas flows to the first region Z 1, and therefore, deployment (deployment) of the first region Z 1 in a direction different from the upward direction may start. In this case, it is difficult to deploy and fill the first region Z 1 of the airbag 91 on the head PH side of the occupant P, thereby restraining and protecting the head PH.The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a side airbag device that can correctly deploy and fill a region of an airbag of a storage shape positioned between a distal portion and a fold line of the distal side at a side of a head of an occupant.In order to solve the above-mentioned problems, there is provided a side airbag device having the features of claim 1, comprising a inflator disposed near a side of an occupant seated in a vehicle seat and ejecting inflation gas in response to an impact applied from a lateral direction of a vehicle, and an airbag accommodated in a storage shape formed by folding and deployed and inflated by the inflation gas between a region extending from a chest region to a head of the occupant and a side wall of the vehicle, wherein the airbag is folded from front to rear in a process of folding the airbag into the storage shape so that the airbag has an intermediate shape of an elongated shape, extending in a direction substantially upward from the inflator, an end thereof near the inflator being a proximal portion and an end remote from the inflator being a distal portion; wherein the intermediate-form airbag forms the storage form by folding back a part of the airbag closer to the distal portion than a proximal-side fold line positioned between the proximal portion and the distal portion in a downward direction along the proximal-side fold line and folding back a part of the airbag closer to the distal portion than a distal-side fold line positioned between the proximal-side fold line and the distal portion in an upward direction at least along the distal-side fold line, and the storage-form airbag is provided with a release delaying portion for delaying a timing for releasing a folded-back state of a region between the distal portion and the distal-side fold line.With the above configuration, when the impact due to the side collision or the like is applied to the vehicle from the lateral direction and therefore the inflation gas is ejected from the inflator, the inflation gas flows in the airbag from a portion close to the inflator to a portion away from the inflator. The airbag is deployed and inflated by the inflation gas between the side wall of the vehicle and the region extending from the chest region to the head of the occupant seated in the vehicle seat. In this case, the area between the proximal portion of the airbag and the proximal side fold line is filled first. Then, the folded-back state of the region between the proximal side fold line and the distal side fold line is released (deployed) and filled. The region between the fold line of the distal side and the distal region is then deployed or deployed and filled.When the inflation gas is about to flow into the region between the distal side fold line and the distal portion before the region between the proximal portion and the proximal side fold line is sufficiently deployed and inflated, or before the region between both fold lines is sufficiently released (deployed) from the folded-back state and is then inflated, the region attempts to release (deploy) the folded-back state. The timing for releasing the folded-back state is delayed by the release delaying portion. For this reason, in the airbag, the region between the proximal portion and the proximal side fold line or the region between both fold lines is sufficiently released (deployed) from the folded-back state and then inflated to release (deploy) the folded-back state of the region between the distal side fold line and the distal portion, so that the region on the side of the head of the occupant can be inflated.In the side airbag device, it is preferable that, in the airbag of the storage shape, a region between the distal portion and the distal side folding line is a first region and a region between the proximal side folding line and the distal side folding line is a second region, and the release delaying portion is formed by a connecting portion for connecting the first region and the second region in a state of being folded back along the distal side folding line and releasing the connecting state according to the inflow of the inflation gas into the first region.With the configuration stated above, when the inflation gas is about to flow into the first region before the region between the proximal portion of the airbag and the proximal side folding line is sufficiently deployed and inflated, or before the second region is sufficiently released (deployed) from the folded-back state and is then inflated, the first region attempts to release (deploy) the folded-back state. However, the release (the deployment) of the folded-back state is delayed by the connection portion functioning as the release delaying portion. At the beginning of the inflow of the inflation gas into the first region, the first region is connected to the second region through the connecting portion in the state of being folded back along the fold line of the distal side. The release (unfolding) of the folded-back state of the first region is restricted by the connecting portion, and therefore the timing of the release of the folded-back state is delayed as much as the restriction.When the connection state of the first region to the second region is released by the connection portion according to the inflow of the inflation gas into the first region, the first region can be released (deployed) from the folded-back state.In the side airbag device, it is preferable that the airbag is divided into a front inflation chamber before the division and a rear inflation chamber behind the division by a partition extending in a substantially vertical direction, the inflator is located at a lower portion of the rear inflation chamber, the partition is provided with an upper communication hole for communicating rear inflation chamber and front inflation chamber at a portion that is a head side of an occupant, the partition is provided with a lower communication hole for communicating rear inflation chamber and front inflation chamber at a portion that is a chest side of an occupant, and the upper communication hole is disposed in the first region, and the lower communication hole is disposed in a third region between the proximal side fold line and the proximal portion.With the above configuration, the inflation gas ejected from the inflator according to the impact from the lateral direction of the vehicle and then supplied to the lower portion of the rear inflation chamber flows in the order of the third region, the second region, and the first region. By the filling gas, the folded state of each region is released (deployed) and filled.In the process in which each region is deployed and filled, the filling gas flows upward in the rear filling chamber. By the inflation gas, the rear inflation chamber is deployed and inflated on the side of the rear portion of the region extending from the chest region to the head of the occupant.A part of the inflation gas that flows upward in the rear inflation chamber and arrives at the portion that is the side of the chest region of the occupant flows into the lower portion of the front inflation chamber through the lower communication hole positioned in the third region. By the inflation gas, the lower portion of the front inflation chamber is deployed and inflated on the front portion side of the occupant's chest region.A part of the inflation gas that flows above the lower communication hole in the rear inflation chamber without passing through the lower communication hole and arrives at the rear portion side of the head of the occupant flows upward in the front inflation chamber through the upper communication hole positioned in the first area. By the inflation gas, the upper portion of the front inflation chamber is deployed and inflated on the front portion side of the head of the occupant.The side airbag device can correctly deploy and fill the region of the airbag of the storage shape positioned between the distal portion and the distal-side fold line on the side of the head of the occupant. FIG. 1 is a side view illustrating an occupant and a vehicle seat provided with a side airbag device according to an embodiment of the present invention; FIG. 2 is a plan view in section illustrating a positional relationship among the vehicle seat, the airbag, the occupant, and a side wall of the vehicle according to the embodiment; FIG. 3 is a front sectional view illustrating a positional relationship among the vehicle seat, the airbag, the occupant, and the side wall of the vehicle according to the embodiment; FIG. 4 is a partial plan view in section illustrating an internal structure of a side portion of a seat back in which an airbag module is accommodated according to the embodiment; FIG. 5 is a side view illustrating the airbag module in a state where the airbag is deployed but not yet inflated according to the embodiment; FIG. 6 is a plan view in section schematically illustrating the internal configuration of the airbag according to the embodiment; FIG. 7 is a partial side elevational view in section illustrating the internal structure of the airbag module in FIG. 5 together with the occupant and the vehicle seat; FIGS. 8A and 8B are diagrams illustrating the state before the airbag of the airbag module according to the embodiment is not folded, wherein FIG. 8A is a side view and FIG. 8B is a sectional view taken along the line A-A; FIG. 9 is a diagram illustrating the airbag module of which the airbag is folded to form an intermediate shape according to the embodiment; FIG. 10 is a partial side view illustrating the airbag module of which the airbag according to the embodiment is molded in the intermediate mold; FIG. 11 is a side view illustrating a state of folding the airbag according to the embodiment; FIG. 12 is a side view illustrating the airbag module of which the airbag according to the embodiment is folded into a storage shape; FIG. 13 is a partial plan view in section illustrating a state in which the airbag is deployed and inflated after jumped out of the vehicle seat, leaving a part of the airbag in a seat back; FIG. 14 is a side view illustrating a relationship of the airbag according to the embodiment and a flow direction of the inflation gas; FIG. 15 is a side view illustrating the airbag module provided with a connection portion different from that of the embodiment; FIG. 16 is a side view illustrating an airbag module whose airbag is folded to form the storage shape in a shape different from that of the embodiment; FIG. 17 is a side view illustrating an airbag module whose airbag is folded to form the storage shape in a shape different from that of the embodiment; and FIG. 18 is a side view schematically illustrating an occupant and a vehicle seat provided with an airbag according to the related art.Description of the Reference Numerals10 Vehicle 11 Side wall 12 Vehicle seat 31 Inflator 40 Airbag 46 Rear inflation chamber 47 Front inflation chamber 50 Partition 54 Upper communication hole 55 Lower communication hole 62 Proximal portion 63 Distal portion 64 Proximal side fold line 66 Distal side fold line 67, 75, 79 Connection portion (release delaying portion) P Occupant PH head PT chest region Z 1 First region Z 2 Second region Z 3 Third regionNext, a side airbag device according to an embodiment will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 to 14.Hereinafter, the direction in which a vehicle advances will be referred to as a forward direction, and the terms front, rear, upper (upward), lower (downward), left and right will be defined with reference to the forward direction. Also, in each drawing, front indicates a front side of the vehicle, rear indicates a rear side of the vehicle, inside indicates an inner side of the vehicle, and outside indicates an outer side of the vehicle. The inner side of the vehicle is a side that is close to the central axis of the lateral direction of the vehicle with respect to the lateral direction of the vehicle, and the outer side of the vehicle is a side that is spaced apart from the central axis.Also, it is assumed that an occupant (adult) having a standard body structure is seated in a vehicle seat in a predetermined posture (normal posture).As illustrated in FIGS. 1, 2 to 3, a vehicle seat 12 is located in the vicinity of the vehicle inner side of a side wall 11 in a vehicle 10. For example, the side wall 11 corresponding to a front seat includes a front door and a center pillar (B pillar). Also, the side wall 11 corresponding to a rear seat includes a rear portion of a side door (back door), a C-pillar, a front portion of a wheel house, and a rear quarter panel ("rear quarter panel").The vehicle seat 12 includes a seat cushion (seat part) 13 and a seat back (backrest) 14 that extends upward from a rear side of the seat cushion 13, and an inclination angle of the seat back 14 is adjusted by a reclining mechanism (not shown). The vehicle seat 12 is disposed in the vehicle 10 with the seat back 14 facing forward. The lateral direction of the vehicle seat 12 arranged in this manner coincides with the lateral direction of the vehicle.The seat back 14 includes a seat back body 15 and a pair of side support portions 16 provided on both sides of the seat back body 15 in the lateral direction of the seat back body 15. The seat back body 15 is inclined rearward to support a torso of an occupant P from behind. Both side support portions 16 project from the seat back body 15 to restrain movement of the upper body of the occupant seated on the seat cushion 13 and inclined against the seat back body 15 from movement in the lateral direction of the vehicle.Next, the internal structure of the seat back 14, specifically, the vehicle exterior side portion including the vehicle exterior side support portion 16 will be described.A seat frame forming a framework of the seat back 14 is installed in the seat back. A portion of the seat frame is located on the vehicle exterior of an inner space of the seat back 14 as illustrated in FIG. 4. The portion of the seat frame is referred to as a side frame portion 17 and is formed by bending a metal sheet. A seat pad 18 formed of an elastic material such as urethane foam is disposed in front of the seat frame including the side frame portion 17. A back plate 19 formed of a hard material such as a synthetic resin is provided behind the seat frame. Although the seat pad 18 is padded by padding, the padding is not shown in FIG. 4. The same applies to FIG. 13 described below.An accommodation portion 21 is provided in the seat pad 18 at a position adjacent to the vehicle exterior side of the side frame portion 17. The position of the accommodation portion 21 is a central portion of the seat back 14 in the up / down direction, and is located obliquely rearward of the occupant P seated in the vehicle seat 12 (see FIG. 2 ). An airbag module AM constituting a main part of the side airbag device is accommodated in the accommodation portion 21.A slit 22 extends diagonally forward and outward from the vehicle outer side and the front corner of the accommodation portion 21. A portion of the seat base 18 that is located between a front corner 18C of the seat base 18 and the gap or slit 22 (i.e., a portion surrounded by a dashed / two-dot chain line in FIG. 4 ) forms a breakable portion 23 to be broken by the airbag 40, which will be described below.The airbag module AM installed in the seat back 14 includes a inflator assembly 30 and the airbag 40 as its main components. Next, each of the components will be described.Inflator Assembly 30The inflator assembly 30 includes an inflator 31 serving as a gas generation source and a container or receptacle 32 covering the inflator 31. In this embodiment, a pyrotechnic gas generator is used as the gas generator 31. The inflator 31 is formed in a generally cylindrical shape and contains therein a gas generating agent (not shown) for generating a inflation gas.In place of the pyrotechnic gas generator using the gas generating agent, it is possible to use a hybrid type gas generator that breaks a division of a high-pressure gas cylinder filled with a high-pressure gas by an explosive to expel gas.On the other hand, the container 32 functions as a diffuser for controlling the discharge direction of the inflation gas and also as a member for fixing the inflator 31 to the side frame portion 17 together with the airbag 40. most parts of the container 32 are formed in a substantially cylindrical shape extending in a substantially vertical direction obtained by bending a plate such as a metal sheet. The container 32 is provided with a communication portion (not shown) for connecting inner and outer sides of the container. Most parts of the inflation gas discharged from the inflator 31 are discharged to the outside from the container 32 via the communication portion.The container 32 is secured to the side frame 17 by a securing member such as bolts 34.The inflator assembly 30 may be configured such that the inflator 31 and the container 32 are integrally formed in one piece.Airbag 40As illustrated by the dashed / two-dot lines in FIGS. 1, 2 to 3, when an impact is applied to the side wall 11 from a lateral direction due to a side collision or the like while the vehicle 10 is traveling, the airbag 40 is supplied with the inflation gas from the inflator 31 and therefore deployed and inflated, so that the airbag 40 is jumped out from the seat back 14 in a state where a portion of the airbag 40 remains in the seat back 14. Here, the deployment means that the airbag is released from the folded state (including the folded-back state) so that the airbag 40 is formed in a flat shape.FIG. 5 is a side view illustrating the airbag module AM in a state (hereinafter referred to as an unfilled deployed state) in which the airbag 40 is deployed in a flat shape without being filled with the inflation gas. FIG. 7 illustrates the internal structure of the airbag module AM together with the occupant P and the seat 12, the airbag 40 being cut at the center of the lateral direction of the vehicle in the non-inflated, deployed, or deployed state in FIG. 5. Further, FIG. 6 shows the internal structure of the airbag 40 deployed and inflated.As illustrated in FIGS. 5, 6 to 7, the airbag 40 is formed by folding one fabric layer (base fabric, also known as a fabric sheet) halfway along a fold line 42 disposed on a center line of the fabric to superimpose the fabric in the vehicle transverse direction, and then connecting the superimposed portions of the fabric to form the shape of a bag. To distinguish two superposed portions of the airbag 40, the fabric placed on the vehicle inner side is referred to as the fabric portion 43, and the fabric placed on the vehicle outer side is referred to as the fabric portion 44. Each of the fabric portions 43 and 44 is formed in a vertically elongated shape with respect to the front and rear direction.According to this embodiment, the fabric is folded halfway such that the fold line 42 is located at a rear end of the airbag 40, but the fabric may be folded halfway such that the fold line 42 is located at another end of the airbag 40, for example, a front end, an upper end, or a lower end thereof. Also, the air bag 40 may be comprised of two panels of fabric divided along the fold line 42. In this case, the airbag 40 is formed by laying one fabric part on the other in the vehicle transverse direction and connecting the two fabric parts to form the shape of a bag. Further, the airbag 40 may be made of three or more fabric pieces.In the airbag 40, the appearance of the two fabric portions 43 and 44 is axis-symmetrical with respect to the fold line 42. the shape and size of each fabric portion 43 and 44 are configured such that the airbag 40 includes the region corresponding to the region from the chest region PT to the head PH in the upper body of the occupant P seated in the vehicle seat 12 when the airbag 40 is deployed and inflated between the vehicle seat 12 and the side wall 11 (see FIGS. 1, 2 to 3 ).A material suitable for the above-mentioned fabric portions 43 and 44 includes a woven fabric made of, for example, a polyester yarn or polyamide yarn, which has high strength and flexibility and can be easily folded.The two fabric portions 43 and 44 are joined together along a peripheral edge joint portion 45 provided at peripheral edges of the fabric portions 43 and 44. In this embodiment, most of the peripheral edge connecting portion 45 is formed by stitching (sewing together with a sewing thread) the peripheral edges of the fabric portions 43 and 44 except for the rear ends thereof (i.e., the vicinity of the fold line 42). The configuration formed by the stitching is similar to an outer connection portion 52 and an inner connection portion 53 described later.In FIGS. 5, 7, 8A, 8B, and 10, the stitched portions of the airbag 40 are represented by three kinds of lines. The first of these lines is a line (a kind of broken line) represented by intermittently aligning or directionally arranging thick lines of a given length, and it shows the quilted portions as viewed from the airbag 40 side (see the peripheral edge connecting portion 45 or the like in FIG. 5 ). The second of these lines is a line (a kind of broken line) represented by intermittently aligning or directionally arranging thin lines of a given length (longer than a general broken line), and it shows a state in which the sewing thread is positioned between the fabric portions 43 and 44 and therefore is not directly seen (hidden) (see the inner connecting portion 53 or the like in FIG. 5 ). The third of these lines is a line (a kind of broken line) represented by aligning or aligning points at regular intervals, and it shows a cross section of the suture that stitches the fabric portions 43 and 44 together (see the peripheral edge connecting portion 45 in FIG. 7 ).As shown in FIGS. 5, 6 to 7, the space enclosed by the peripheral edge connecting portion 45 between the two fabric portions 43 and 44 forms a inflation portion deployed and inflated by the inflation gas on the upper body side of the occupant P to protect the region extending from the chest region PT and the head PH from the shock.In this case, the peripheral edge connecting portion 45 may be formed by a means other than the stitching using the suture, for example, by bonding using an adhesive. The configuration formed by the bonding is similar to the outer joint portion 52 and the inner joint portion 53 described later.The airbag 40 is provided with a partition 50 at the inner central portion thereof in a longitudinal direction, and the partition extends in a substantially vertical direction. Therefore, the airbag 40 is divided into a rear inflation chamber 46 at a position rearward of the partition 50, and a front inflation chamber 47 at a position forward of the partition 50. The partition 50 has the same configuration as one generally referred to as a link ("tether"). Next, explanations will be made with respect to the division 50.Division 50The partition 50 comprises a pair of fabric parts 51 of a material having high strength and flexibility and being easily folded, for example, the same woven fabric as the fabric portions 43 and 44. Each fabric member 51 is connected to the opposite one of the two fabric portions 43 and 44 of the airbag 52 through the outer connecting portion 52 extending in the substantially vertical direction along the rear edge thereof. When the airbag 40 is inflated, the two outer joint portions 52 are joined to the fabric portions 43 and 44 corresponding to the rear end of the fabric part 51 at the portion that is the side of the central portion in the horizontal direction in the upper body of the occupant P. Both fabric pieces 51 are joined together by the inner joint portion 53 extending in the substantially vertical direction along the front edge thereof.The partition 50, which is made of a pair of fabric pieces 51, is interposed between the vehicle inner side fabric portion 43 and the vehicle outer side fabric portion 44 in the airbag 40. The partition 50 is in the superimposed state in the vehicle lateral direction when the airbag 40 is in the non-inflated deployed state (see FIGS. 5 and 7 ). Also, the partition 50 is strained in the vehicle lateral direction when the airbag 40 is inflated (see FIG. 6 ), and therefore, limits the thickness (inflation thickness) of the airbag 40 in the vehicle lateral direction.The partition 50 is provided with an upper communication hole 54 for communicating the rear inflation chamber 46 and the front inflation chamber 47 in the portion that is the head PH side of the occupant P when the airbag 40 is inflated. Also, the partition 50 is provided with a lower communication hole 55 for communicating the rear inflation chamber 46 and the front inflation chamber 47 at the portion that is the chest region PT side of the occupant P when the airbag 40 is inflated. Specifically, the inner connecting portion 53 connecting both fabric parts 51 is not engaged at two portions, i.e., the upper end and the lower end, in the vertical direction. The upper end and the lower portion in the vertical direction are not provided with the inner connecting portion 53 connecting the two fabric parts 51. The upper end non-engagement portion of the inner connection portion 53 forms the upper communication hole 54 and the lower portion non-engagement portion of the inner connection portion 53 forms the lower communication hole 55. The upper communication hole 54 and the lower communication hole 55 are closed in the state where both fabric parts 51 are superposed and opened in the state where the partition 50 is strained in the lateral direction of the vehicle when the airbag 40 is inflated.Most of the above-described inflator assembly 30 is housed in the lower portion of the rear end of the rear inflation chamber 46, the inflator assembly extending in a substantially vertical direction. The bolt 34 of the container 32 is inserted into the vehicle inner side fabric portion 43 of the airbag 40. With the insertion, the inflator assembly 30 is locked in a state of positioning with respect to the airbag 40.Further, the vehicle exterior side fabric portion 44 serves as the front portion of the front inflation chamber 47, and has a vent hole 56 between the upper communication hole 54 and the lower communication hole 55. The fabric portion 44 is provided with a reinforcing portion 57 in the vicinity of the vent hole 56, and the reinforcing portion 57 is formed by stitching it with the suture. The reinforcing portion 57 reinforces the vicinity of the vent hole 56 of the fabric portion 44 to prevent the portion from being burst or loosened.As illustrated in FIGS. 4 and 14, the airbag module AM including the inflator assembly 30 and the airbag 40 as main components thereof is configured to have a compact shape (hereinafter referred to as a storage shape) in which the airbag 40 is folded. This serves to fit the airbag module AM into the restricted-size accommodation portion 21 in the seat back 14 for the purpose of appropriate accommodation.The storage shape is obtained by folding the airbag 40 of the non-inflated deployed state as shown in FIGS. 8, 9, 10, 11 to 12. Next, a process of folding the airbag 40 will be described.FIG. 8A shows the airbag module AM of the non-inflated deployed state in which the fold line 42 and the axis AL of the inflator assembly 30 extend in the vertical direction when viewed from the outside of the vehicle. FIG. 8B shows a cross-sectional structure along the line A-A of the airbag module AM. The fold lines 61 parallel to the fold line 42 and the axis AL are defined at a plurality of positions of the airbag 40 in the airbag module AM. The airbag 40 is folded front-to-back by a roll fold manner which folds the airbag repeatedly in the same direction along each fold line 61. By the folding, the airbag 40 is formed into an intermediate shape formed in an elongated shape that extends in a substantially upward direction from the inflator assembly 30, as illustrated in FIGS. 9 and 10. To specify each portion in the intermediate-form airbag 40, an end (lower end) near the inflator assembly 30 is referred to as proximal portion 62, while the end (upper end) remote from the inflator assembly 30 is referred to as distal portion 63.As illustrated in FIG. 10, the intermediate-form airbag 40 is configured with a proximal-side folding line 64 parallel to the extending direction of a bolt 34 at the slightly upward portion of the inflator assembly 30 between the proximal portion 62 and the distal portion 63. In the intermediate-form airbag 40, the distal-side portion 65 (upper side of FIG. 10 ) except the proximal-side fold line 64 is folded back forward and downward along the proximal-side fold line 64, as indicated by the arrow in FIG. 10. By folding back the section, a section of section 65 is positioned in front of inflator assembly 30, as illustrated in FIG. 11.The intermediate form airbag 40 is configured with a distal side fold line 66 parallel to the proximal side fold line 64 between the proximal side fold line 64 and the distal portion 63. In the airbag 40, the area between the distal portion 63 and the distal side fold line 66 is referred to as a first area Z 1, and the area between the proximal side fold line 64 and the distal side fold line 66 is referred to as a second area Z 2. Further, in the airbag 40, the region between the proximal side fold line 64 and the proximal portion 62 is referred to as a third region Z 3.The first region Z 1 is folded back forward and upward along the fold line of the distal side 66, as indicated by the arrow in FIG. 11. By folding back the portion, the airbag module AM is formed in the storage shape indicated by a solid line in FIG. 12. In the memory form, the first region Z 1 is positioned in front of the second region Z 2.The airbag module AM of the storage shape formed by folding the airbag 40 is reduced in size in the direction (vertical direction) with respect to the axis AL of the inflator assembly 30, and therefore is suitable for accommodation in the narrow accommodation portion 21 of the seat back 14.In this embodiment, the intermediate-form airbag 40 is provided with a release delaying portion for delaying the timing of releasing the folded-back state of the first region Z 1 during deployment and inflation. The release delaying portion is formed of a connecting portion 67 for connecting the first region Z 1 and the second region Z 1 in the state of being folded back along the distal side fold line 66 and releasing the connecting state according to the inflow of the inflation gas into the first region Z 1. Here, the connecting portion 67 is formed of an adhesive tape wound around the first region Z 1 and the second region Z 2 of the airbag 40 to connect the first region Z 1 and the second region Z 2 in the state of being folded back along the distal side fold line 66, and which is broken according to the inflow of the inflation gas into the first region Z 1 to release the connecting state.In this embodiment, the proximal side fold line 64 and the distal side fold line 66 are configured such that the above-described upper communication hole 54 is positioned in the first region Z 1 and the lower communication hole 55 is positioned in the third region Z 3.In the airbag module AM of the storage form, as shown in FIG. 4, the bolt 34 extending from the retainer 32 and inserted into the airbag 40 (fabric portion 43) is inserted into the side frame portion 17. When the nut 35 is fastened to the bolt 34, the inflator assembly 30 is fastened to the side frame portion 17 together with the airbag 40.In this case, the inflator assembly 30 may be fastened to the side frame portion 17 by a member other than the bolt 34 and the nut 34 described above.As illustrated in FIG. 1, the side airbag device includes an impact sensor 71 and a controller 72 in addition to the above-described airbag module AM (see FIG. 2 ). The impact sensor 71 includes an acceleration sensor or the like, and is installed on the side wall 11 of the vehicle 10 (see FIG. 2 ) or the like to detect the impact applied to the side wall 11 from the side. The controller 72 controls the operation of the inflator 31 according to the signal detected by the impact sensor 71.Although the vehicle 10 is provided with a seat belt device for restraining the occupant P seated in the vehicle seat 12 in the vehicle seat 12, such a seat belt device is not shown in FIG. 1 or the like.Next, the operation of the side airbag device including the configuration according to this embodiment will be described.According to the side airbag device, when no impact is applied to the side wall 11 of the vehicle 10 from the lateral direction due to the side collision or the like, no operation signal is output from the control device 72 to the inflator 31 to operate the inflator 31, and therefore no inflation gas is supplied from the inflator 31 to the airbag 40. The airbag module AM is still accommodated in the accommodation portion 21 as the storage shape (see FIG. 4 ).When an impact of a given or larger value is applied to the side wall 11 from the lateral direction due to the side collision or the like during traveling of the vehicle and then detected by the impact sensor 71, an operation signal is output from the controller 72 to the inflator 31 to operate the inflator 31 in response to the detected signal. In response to the operation signal, a gas generating agent generates the high-pressure inflation gas in the gas generator 31 and then the inflation gas is discharged therefrom. The discharged inflation gas is supplied to the airbag 40 through the communication portion of the container 32. Here, the airbag 40 is partitioned into the rear inflation chamber 46 and the front inflation chamber 47 by the partition 50 provided at the central portion in the longitudinal direction thereof, and the inflator assembly 30 is disposed at the lower portion of the inner rear end of the rear inflation chamber 46. For this reason, the inflation gas from the inflator 31 is supplied to the lower portion of the inner rear end of the rear inflation chamber 46.As illustrated in FIGS. 12 and 14, the inflation gas tends to flow into the rear inflation chamber 46 from the portion near the inflator assembly 30 to the portion remote from the inflator assembly, i.e., in the order of the third region Z 3, the second region Z 2, and the first region Z 1. The third region Z 3, the second region Z 2 and the first region Z 1 are filled by the filling gas or the folded-back state is released (deployed). For example, the third region Z 3 is filled forward by the filling gas from the inflator assembly 30. The third filling region Z 3 pushes the second region Z 2 in the forward direction. By the pushing, the second region Z 2 tends to slide forward and upward along a curved trajectory using the proximal side fold line 64 as a rotation axis.When the filling gas is about to flow into the first region Z 1 before the third region Z 3 is sufficiently deployed and filled by the filling gas or before the second region Z 2 is sufficiently released (deployed) from the folded-back state and then filled, the first region Z 1 attempts to release (deploy) the folded-back state. The timing of releasing the folded-back state is delayed as indicated below. At the beginning of the inflow of the inflation gas into the first region Z 1, the first region Z 1 is connected to the second region Z 2 in the state of being folded back along the distal side fold line 66 by the connecting portion 67 wound around the first region Z 1 and the second region Z 2 of the airbag 40. The release (deployment) of the folded-back state of the first region Z 1 is restricted by the connection portion 67, and therefore the timing of releasing the folded-back state is delayed as much as the restriction. The first region Z 1 connected to the second region Z 2 through the connecting portion 67 is integrated with the second region Z 2 as indicated by the dashed / double-dotted line in FIG. 12, i.e., the first region Z 1 and the second region Z 2 result in mass, and therefore the second region Z 2 slides forward and upward along the curved trajectory using the fold line of the proximal side 64 as a rotation axis.In the process in which the mass of the first region Z 1 and the second region Z 2 shifts to or near the upper side of the third region Z 3, the first region Z 1 is filled according to the inflow of the filling gas into the first region Z 1. The connecting portion 67 is pushed and broken by the first region Z 1 being filled, and therefore the state of connection of the first region Z 1 with the second region Z 2 is released by the connecting portion 67. When the inflation gas flows into the second region Z 2, the second region Z 2 is inflated while the roll-folded state is released (deployed).By releasing the connection state, it is possible to release (deploy) the folded-back state of the first region Z 1. The first filling portion Z 1 slides rearward and upward along a curved trajectory using the distal side fold line 66 as a rotation axis, and thus the folded-back state of the first portion Z 1 is released (unfolded). In this way, the third region Z 3 and the second region Z 2 are filled by sufficiently releasing (deploying) the folded-back state, and then the folded-back state of the first region Z 1 is released (deploying). Continuously, the roll-folded state of the first region Z 1 is released (deployed) by the filling gas, and then the first region is filled.As described above, when the folded-back state of the second region Z 2 and the first region Z 1 is released (deployed) and the regions are then filled, the filling gas flows as indicated below. As illustrated in FIG. 14, the inflation gas flows in the rear inflation chamber 46 from rear to front and simultaneously from bottom to top. When the inflation gas flowing from the rear toward the front arrives at the partition 50, the flow direction is turned upward along the partition 50, and then the inflation gas joins with the inflation gas flowing upward from the beginning.The volume of the rear inflation chamber 46 is smaller than that of the airbag 40 in a case where the airbag 40 is not divided by the partition 50. Also, the inflation thickness of the rear inflation chamber 46 with respect to the vehicle width direction is smaller than that of the vehicle 40 in the vehicle width direction in a case where the airbag 40 is not divided. For this reason, the rear inflation chamber 46 is easily deployed and inflated while passing through the narrow space between the shoulder PS of the occupant P and the side wall 11.As illustrated in FIGS. 7 and 14, a part of the inflation gas that flows upward in the rear inflation chamber 46 and arrives at the rear portion side of the chest region PT of the occupant P flows downward in the front inflation chamber 47 through the lower communication hole 55 positioned in the third region Z 3. Also, a part of the inflation gas that flows upward outside the lower communication hole 55 in the rear inflation chamber 46 without passing through the lower communication hole 55 and arrives at the rear portion side of the head PH of the occupant P flows upward through the upper communication hole 54 positioned in the first area Z 1 in the front inflation chamber 47.A part of the inflation gas flowing in the front inflation chamber 47 through the lower communication hole 55 turns up and down. Also, a part of the inflation gas flowing into the front inflation chamber 47 through the upper communication hole 55 turns downward.In the process in which the airbag 40 is deployed and inflated upward and forward by the inflation gas, the seat pad 18 of the seat back 14 is pushed by the airbag 40, and therefore the breakable portion 23 in FIG. 4 is broken. As illustrated in FIG. 13, the airbag 40 jumps out of the seat back 14 in a substantially forward direction of the vehicle 10 in a state where the rear end of the airbag 40 remains in the accommodation portion 21 together with the inflator assembly 30.Subsequently, the airbag 40 is deployed and inflated between the region extending from the chest region PT of the occupant P and the side wall 11 of the vehicle 10.The airbag 40 deployed and inflated as described above is pinched between the occupant P and the side wall 11 moving toward the vehicle inner side as indicated by the broken / two-dot lines in FIGS. 2 and 3, thereby directly pushing and restraining the occupant P toward the vehicle inner side and, at the same time, suppressing the impact applied to the occupant P from the lateral direction by the side wall 11.In this case, the inflation gas that flows into the upper portion of the front inflation chamber 47 through the upper communication hole 54 and turns downward is discharged to the outside of the airbag 40 (outside of the vehicle except the fabric portion 44) through the vent hole 56. Since the internal pressure is reduced by the discharge of the inflation gas, the shock applied to the occupant P from the lateral direction by the side wall 11 is alleviated. Also, since the inflation gas that deploys and fills the upper portion of the front inflation chamber 47 as described above is discharged from the vent hole 56, the inflation gas is prevented from flowing to the lower portion of the front inflation chamber 47 located below the vent hole 56. As a result, the lower portion of the front inflation chamber 47 is prevented from being deployed and inflated due to the excessive pressure applied from the lateral direction of the chest region PT.According to the above-described embodiment, the effects given below are obtained.(1) The storage-type airbag 40 is provided with the release delaying portion for delaying the timing of releasing the folded-back state of the first region Z 1 (see FIG. 12 ).For this reason, after the folded-back state of the third region Z 3 and the second region Z 2 in the airbag 40 is sufficiently released (deployed), the third and second regions are inflated, and then the folded-back state of the first region Z 1 is released (deployed), so that the first region Z 1 on the head PH side of the occupant P can be properly inflated.(2) The first region Z 1 is connected to the second region Z 2 in the state of being folded back along the distal side fold line 66, and is provided with the connection portion 67 for releasing the connection portion in accordance with inflow of the inflation gas into the first region Z 1. The connection portion 67 functions as the release delaying portion (see FIG. 12 ).For this reason, the release (unfolding) of the folded-back state of the first region Z 1 is restricted by the connecting portion 67, so that the timing of releasing the folded-back state can be delayed. Also, the connection state of the first region Z 1 with the second region Z 2 is released by the connection portion 67 by the inflow of the inflation gas into the first region Z 1, thereby releasing (deploying) the folded-back state of the first region Z 1.(3) The airbag 40 is partitioned into the front inflation chamber 47 before the partition 50 and the rear inflation chamber 46 behind the partition 50 by the partition 50 extending in the substantially vertical direction. The inflator 31 is disposed at the lower portion of the rear inflation chamber 46. The partition 50 is provided with the upper communication hole 54 for communicating the rear inflation chamber 46 and the front inflation chamber 47 at the portion that is the head PH side of the occupant P. The partition 50 is provided with the lower communication hole 55 for communicating the rear inflation chamber 46 and the front inflation chamber 47 in the portion that is the chest region PT side of the occupant P (see FIG. 7 ). The upper communication hole 54 is disposed in the first area Z 1 and the lower communication hole 55 is disposed in the third area Z 3.For this reason, by the inflation gas flowing forward in the rear inflation chamber 46, the rear inflation chamber 46 can be deployed and inflated on the rear portion side of the region extending from the chest region PT to the head PH of the occupant P.Also, by the inflation gas flowing in the lower portion of the front inflation chamber 47 through the lower communication hole 55 positioned in the third region Z 3, the lower portion of the front inflation chamber 47 can be deployed and inflated on the front portion side of the chest region PT of the occupant P.By the inflation gas flowing into the upper portion of the front inflation chamber 47 through the upper communication hole 54 positioned in the first area Z 1, the upper portion of the front inflation chamber 47 can be deployed and inflated on the front portion side of the head PH of the occupant P.In this way, the airbag 40 can be properly deployed and inflated between the region extending from the chest region PT and the head PH of the occupant P and the side wall 11 of the vehicle 10 to properly restrain and protect the region of the occupant P.The embodiment may be modified as indicated below.The inflator 31 can be directly attached to the side frame 17 without using the retainer 32.The almost entire part of the airbag 40 may be inflated as in the embodiment, but the airbag 40 may be provided with a non-inflation portion that is not supplied with the inflation gas and is therefore not inflated.The partition 50 may be formed of a fabric partition.Instead of the seat back 14 of the vehicle seat 12, the side wall 11 may be provided with a portion corresponding to the accommodation portion 21, and the airbag module AM may be inserted therein.Instead of the adhesive tape, a thread or an adhesive (not illustrated) satisfying the conditions indicated below may form the bonding portion 67.Condition 1: The first region Z 1 of the airbag 40 is connected to the second region Z 2 in a state where the first region is folded back along the distal side fold line 66.In the case of the thread, the bonding is performed by winding it around the first region Z 1 and the second region Z 2. In the case of the adhesive, the bonding is performed by adhering a part of the first region Z 1 and a part of the second region Z 2 together.Condition 2: The connection is released by the fact that the connection portion is broken by the filling of the first region Z 1 caused by the inflow of the filling gas.In the case of the thread, the release of the connection is performed by the fact that the connection portion is pushed and cut by the first filling area Z 1. In the case of the adhesive, the release of the joint is performed by the fact that the joint portion is pushed and separated by the first filling area Z 1.In the case of either the thread or the adhesive, the same operations and effects as those of the case where the adhesive tape is used as the joint portion 67 are obtained.As illustrated in FIG. 15, instead of an adhesive tape, a thread satisfying the following specified conditions may form the joint portion 75.Condition 1: Since a part of the first region Z 1 of the airbag 40 is sewn to a part of the second region Z 2, the first region Z 1 is connected to the second region Z 2 in a state where the first region is folded back along the distal side fold line 66.Condition 2: The connection is released by the fact that the connection portion is cut by the filling of the first region Z 1 caused by the inflow of the filling gas.In this case, the same operations and effects as those of the case where the adhesive tape is used as the bonding portion 67 are obtained.In order to configure the airbag module AM whose airbag 40 has the intermediate shape in the storage shape, the first region Z 1 may be folded back and forth along the distal side fold line 66, as illustrated in FIG. 16. In this case, the first region Z 1 is positioned between the second region Z 2 and the third region Z 3.The airbag 40 may be formed in the storage shape by further folding back the first region Z 1. FIG. 17 shows an example thereof, wherein a fold line 76 is further arranged parallel to the screw 34 between the distal portion 63 and the distal side fold line 66, and a distal side portion 77 except the fold line 76 is folded forward and downward.In this case, it is preferred that a portion 78 between the distal side fold line 66 and the fold line 76 is connected to the portion 77 by a new connecting portion 79. In the case of this modification, the timing of releasing (deploying) the folded-back state of the portion 77 is delayed, so that the first region Z 1 on the head PH side of the occupant P can be properly deployed and inflated.The number of the connecting portions 67 can be changed. FIG. 16 shows an example in which a connection portion 67 is provided.The position of the connection portion 67 may be changed. FIG. 16 shows an example in which the connection portion 67 is provided at the central portion with respect to the longitudinal direction of the first region Z 1 and the second region Z 2.In order to configure the airbag 40 in the intermediate form, the airbag 40 of the non-inflated deployed state may be bellows-folded from front to rear. Bellows folding is a folding aspect of the alternating change in the fold-back direction. Also, in order to configure the airbag in the intermediate form, the airbag 40 of the non-inflated deployed state may be folded by a combination of roll folds and bellows folds from front to rear. For example, in the airbag 40 of the non-inflated deployed state, the portion forward of the center portion may be roll-folded with respect to the front-rear longitudinal direction, and the portion rearward of the center portion may be bellows-folded from front to rear.Technical ideas obtained from the above-described embodiments will be described below together with the effects thereof. (A) In the side airbag device according to the second aspect, the connecting portion is formed of the thread or the adhesive tape wound around the first region and the second region of the airbag to connect the first region and the second region in a state of being folded back along the fold line of the distal side, and is broken according to the inflow of the inflation gas into the first region to release the connected state.With the above configuration, since the adhesive tape or the thread is wound around the first portion and the second portion of the airbag, the first portion is joined to the second portion in the state of being folded back along the distal side fold line. The adhesive tape or thread is pushed through the first filling region and broken, so that the bonding state is released.(B) In the side airbag device according to the second aspect, the connecting portion is formed by the adhesive adhering to a part of the first region and a part of the second region of the airbag to connect the first region and the second region in the state of being folded back along the fold line of the distal side, and is separated when the first region is filled corresponding to the inflow of the inflation gas into the first region, thereby releasing the connecting state.With the above configuration, since a part of the first region and a part of the second region adhere to each other by the adhesive interposed between the regions, the first region is joined to the second region in the state of being folded back along the distal side fold line. When the adhesive is separated by the first filling portion, the bonding state is released.(C) In the side airbag device according to the second aspect, the connecting portion is formed by the thread sewing a part of the first region and a part of the second region of the airbag to connect the first region and the second region in the state of being folded back along the fold line of the distal side, and is separated when the first region is inflated according to the inflow of the inflation gas into the first region, thereby releasing the connecting state.With the above configuration, since a part of the first region of the airbag is sewn to a part of the second region by the thread, the first region is connected to the second region in the state of being folded back along the distal side fold line. The thread is pushed through the first filling region and cut, so that the connection state is released.

Claims

A side airbag device comprising: a inflator (31) that is disposed or to be disposed near a side of an occupant (P) seated in a vehicle seat (12) and ejects inflation gas in response to an impact applied from a lateral direction of a vehicle (10); and an airbag (40) that is accommodated in a storage shape formed by folding and is deployed and inflated by the inflation gas between a region extending from a chest region (PT) to the head (PH) of the occupant (P) and a side wall (11) of the vehicle (10), wherein the airbag (40) is folded from a front side to a rear side in a process of folding the airbag (40) into the storage shape so that the airbag (40) has an intermediate shape of an elongated shape, extending from the inflator (31) in a substantially upward direction, an end close to the inflator (31) being a proximal portion (62) and an end remote from the inflator (31) being a distal portion (63), the intermediate shape airbag (40) being the storage shape by folding back a part of the airbag (40) that is closer to the distal portion (63) than a proximal side fold line (64) positioned between the proximal portion (62) and the distal portion (63) in a downward direction along the proximal side fold line (64) and by folding back a part of the airbag (40) that is closer to a distal side fold line (66) positioned between the proximal side fold line (64) and the distal portion (63), the distal portion (63) is provided, in an upward direction at least along the distal side fold line (66), and the storage shape airbag (40) is provided with a release delaying portion (67) for delaying a timing of releasing a folded-back state of a region between the distal portion (63) and the distal side fold line (66); wherein, in the storage-shape airbag (40), a region between the distal portion (63) and the distal-side fold line (66) is a first region (Z 1) and a region between the proximal-side fold line (64) and the distal-side fold line (66) is a second region (Z 2), and the release delaying portion (67) is formed by a connecting portion (67; 75) that connects the first region (Z 1) and the second region (Z 2) in a state of being folded back along the distal-side fold line (66) and releases the connecting state according to inflow of the inflation gas into the first region (Z 1).The side airbag device according to claim 1, wherein the airbag (40) is divided into a front inflation chamber (47) before the division (50) and a rear inflation chamber (46) after the division (50) by a partition (50) extending in a substantially vertical direction, the inflator (31) is disposed at a lower portion of the rear inflation chamber (46), the partition (50) is provided with an upper communication hole (54) for communicating the rear inflation chamber (46) and the front inflation chamber (47) at a portion that is a head (PH) side of the occupant (P), the partition (50) is provided with a lower communication hole (55) for communicating the rear inflation chamber (46) and the front inflation chamber (47) at a portion, which is one side of the chest region (PT) of the occupant (P), and the upper communication hole (54) is disposed in the first region (Z1), and the lower communication hole (55) is disposed in a third region (Z3) between the fold line (64) of the proximal side and the proximal portion (62).The side airbag device according to claim 1 or 2, wherein the connecting portion (67;75) is formed by an adhesive tape, a thread, or an adhesive.

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