JP2014237411A - Side airbag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a side airbag device capable of smoothly expanding a folding part on a tip end in an expansion direction of an airbag.SOLUTION: The side airbag device comprises: an inflator assembly 30; and an airbag 40. The inflator assembly 30 is disposed in the vicinity of a side part of a chest of a seating person seating on a vehicular seat and jets inflation gas in response to impact from the side direction of the vehicle. The airbag 40 is stored in a state that plural folding parts 66, 68, 69, 72, 73 are formed, and expands and inflates between a portion from the chest to the head part of the seating person seating on the vehicular seat and a side wall part of the vehicle by the inflation gas from the inflator assembly 30. In this side airbag device, the folding parts 68, 72 on the tip end in the expansion direction of the airbag 40 are folded to a cabin side (near side of a figure 12 (a)).

Description

  According to the present invention, when an impact is applied to a vehicle from a side due to a side collision or the like, an airbag is deployed and inflated between an occupant seated on a vehicle seat and a side wall portion of the vehicle, thereby The present invention relates to a side airbag device that protects a portion from a head to a head from an impact.

  2. Description of the Related Art A side airbag device including an airbag and an inflator is widely known as a device that protects the upper body of an occupant seated on a vehicle seat from an impact caused by a side collision or the like. In this side airbag device, the airbag is stored in a seat back (backrest) of a vehicle seat together with an inflator in a folded state. When an impact is applied to the side wall portion of the vehicle, such as a side door, from the side due to a side collision or the like, inflation gas is supplied from the inflator to the airbag. The airbag is deployed and inflated and pops out of the vehicle seat with a portion left in the seat back. Thereafter, the airbag is deployed and inflated in a narrow space between the occupant and the side wall. This airbag is interposed between the upper body of the occupant and the side wall portion that enters the inside of the vehicle and restrains the upper body of the occupant, and reduces the impact from the side transmitted to the upper body through the side wall portion.

  As one aspect of the side airbag device, there is one described in Patent Document 1, for example. In this side airbag device, the inflator is disposed in the seat back and in the vicinity of the side of the chest of the occupant seated on the vehicle seat. When the inflation gas is ejected from the inflator in response to an impact caused by a side collision or the like, the inflation gas flows upward and forward in the folded airbag. By this inflation gas, the airbag is deployed and inflated toward the front and the top of the vehicle between a portion from the chest to the head of the occupant seated on the vehicle seat and the side wall of the vehicle.

Patent Document 2 describes a side airbag device that restrains and protects a portion of the upper body of an occupant that is different from the above-described portion.
In any of the side airbag devices described in Patent Document 1 and Patent Document 2, when the airbag is folded, the folded portion at the upper end that is the tip in the deployment direction is folded.

JP 2007-203939 A JP 2010-070178 A

  However, in the side airbag devices described in Patent Literature 1 and Patent Literature 2, when the inflation gas is supplied and the airbag is inflated, the folded portion of the folded upper end of the airbag is directed toward the outside of the vehicle. May expand. In this case, in the process of eliminating (deploying) the folded state of the folded portion at the upper end of the airbag, the airbag may come into contact with the side wall of the vehicle, and smooth deployment may be hindered by friction.

  The above-described problem can occur in the same manner as described above even in the airbag that is deployed and inflated from the rear to the front by the inflating gas and the folded portion at the front end that is the front end in the deployment direction is folded back.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a side airbag device that can smoothly deploy the folded portion at the tip end in the airbag deployment direction. is there.

  A side airbag device that solves the above problems is arranged in the vicinity of the side of a chest of an occupant seated on a vehicle seat, and includes an inflator that blows inflating gas in response to an impact from the side of the vehicle, and a plurality of folding portions. An airbag that is housed in a folded state so as to be formed, and that is deployed and inflated between a portion from the occupant's chest to the head and a side wall of the vehicle by the inflation gas from the inflator In the side airbag device, a folded portion at the tip in the deployment direction of the airbag is folded back toward the vehicle interior side.

  According to the above configuration, when an impact is applied to the vehicle from the side due to a side collision or the like, the inflation gas is ejected from the inflator. The inflating gas is supplied toward the folding portion far from the folding portion close to the inflator, and the folding portion expands in this order while canceling (unfolding) the folding. When the inflation gas is supplied to the folded portion at the distal end in the airbag deployment direction, the inflation gas expands while eliminating (deploying) the folded state of the folded portion toward the vehicle interior side. During the expansion and expansion, the folded portion at the tip does not come into contact with the side wall of the vehicle, and it is difficult for smooth expansion to be hindered by friction with the side wall.

  In the side airbag device, at least a part of the airbag is folded from the upper side to the lower side so as to form a plurality of folded portions, and is expanded and inflated from the lower side to the upper side. It is preferable that the folded portion at the upper end of the airbag is folded back toward the vehicle interior as the folded portion at the tip end in the deployment direction.

  According to the above configuration, at least a part of the inflation gas ejected from the inflator in response to an impact from the side of the vehicle is supplied from the lower folding part to the upper folding part. With the inflation gas, the airbag is inflated while sequentially canceling (deploying) the folding from the lower folding portion toward the upper folding portion. When the inflation gas is supplied to the folded portion at the upper end, which is the tip of the airbag in the deploying direction, the folded state of the folded portion is eliminated (deployed). During this expansion, the folded portion at the upper end does not come into contact with the side wall of the vehicle, and it is difficult for smooth expansion to be hindered by friction with the side wall.

  In the side airbag device, the airbag is partitioned by a partition wall extending in a substantially vertical direction into a front expansion chamber on the front side of the partition wall and a rear expansion chamber on the rear side of the partition wall. An upper communication hole is provided in a lower part of the expansion chamber and is located on a side of the occupant's head in the partition wall. The upper communication hole communicates the rear expansion chamber and the front expansion chamber. A lower communication hole for communicating the rear expansion chamber and the front expansion chamber is provided at a location on the side of the chest of the occupant, and the compartment of the airbag folded from above to below The region in front of the wall is folded from the front to the back by roll folding, which is repeatedly folded in the same direction, and the region in the rear of the partition wall is folded in a bellows manner by alternately changing the folding direction. It is preferable that the folded toward the front to the rear by.

  According to the above configuration, part of the inflation gas ejected from the inflator in response to the impact from the side of the vehicle flows upward and forward in the rear inflation chamber. By this expanding gas, the bellows-folded portion behind the partition wall is expanded and expanded forward. Here, the bellows fold has a feature that the folded state can be easily eliminated. Therefore, the bellows-folded portion behind the partition wall is rapidly expanded and inflated forward on the occupant's chest and the rear side of the head, and the above-mentioned portion of the occupant is quickly restrained and protected.

  Part of the inflation gas that has flowed upward in the rear inflation chamber and reached the rear side of the chest of the occupant flows into the lower portion of the front inflation chamber through the lower communication hole. In addition, a part of the inflation gas that does not pass through the lower communication hole and flows in the rear expansion chamber above the lower communication hole and reaches the rear side of the occupant's head passes through the upper communication hole. Into the upper part of the front expansion chamber. By these expansion gases, the roll-folded portion ahead of the partition wall is expanded and expanded forward. Here, the roll fold has a feature that it is easy to expand along the side wall of the vehicle. Therefore, the roll-folded part in front of the partition wall expands and expands forward along the side wall of the vehicle on the front side of the occupant's chest and head, and accurately restrains the above-mentioned part of the occupant. Protect.

  In the side airbag device, at least a lower portion of the airbag is folded from the front to the rear so that a plurality of folded portions are formed, and the deployment and the expansion are performed from the rear to the front. And it is preferable that the folding part of the lower front end of the airbag is folded back to the inside of the vehicle as a folding part at the tip in the deployment direction.

  According to the above configuration, at least a part of the inflation gas ejected from the inflator is supplied from the rear of the lower portion of the airbag toward the front in response to an impact from the side of the vehicle. With this inflating gas, folding is canceled (deployed) in order from the rear folding part toward the front folding part at the lower part of the airbag. Then, when the inflation gas is supplied to the folded portion at the lower front end, which is the tip of the airbag in the deployment direction, the folded state of the folded portion is canceled (deployed). During this expansion, the folding portion does not contact the side wall portion of the vehicle, and it is difficult for smooth expansion to be hindered by friction with the side wall portion.

  In the side airbag device, the airbag is partitioned by a partition wall extending in a substantially vertical direction into a front expansion chamber on the front side of the partition wall and a rear expansion chamber on the rear side of the partition wall. A lower communication hole is provided at a lower portion of the expansion chamber and is located on the side of the chest of the occupant on the partition wall. The lower communication hole communicates the rear expansion chamber and the front expansion chamber. The folded part at the lower front end is preferably folded back in a state of intersecting the partition wall.

  According to the above configuration, at least part of the inflation gas ejected from the inflator flows from the rear of the lower portion of the rear expansion chamber toward the front in response to an impact from the side of the vehicle. With this gas for expansion, the lower part of the rear expansion chamber cancels (deploys) the folding in order from the rear folding part toward the front folding part. Then, the inflating gas inflates the rear portion of the folding portion at the lower front end, which is the front end in the airbag deployment direction, with respect to the partition wall.

  Further, a part of the expansion gas ejected from the inflator flows upward in the rear expansion chamber. When the inflation gas flows upward in the rear inflation chamber and reaches the side of the chest of the occupant, the inflation gas passes through the lower communication hole and flows to the front portion of the folding portion at the lower front end. . With this inflation gas, the folded state of the folded portion toward the vehicle inner side is eliminated (deployed). At this time, since the front part of the folded part is pushed by the rear part of the partition wall that has started to expand as described above, the unfolding is performed quickly.

  According to the side airbag device, since the folded portion at the front end in the airbag deployment direction is folded back toward the vehicle interior, the folded portion can be smoothly deployed.

It is a figure which shows one Embodiment of a side airbag apparatus, and is a side view which shows the vehicle seat provided with the apparatus with an airbag and a passenger | crew. In one embodiment, the plane cross section which shows the positional relationship of a vehicle seat, an airbag, a passenger | crew, and a side wall part. 1 is a front sectional view showing a positional relationship among a vehicle seat, an airbag, an occupant, and a side wall portion in one embodiment. In one embodiment, the partial plane sectional view showing the internal structure of the side part of the seat back in which the air bag module was incorporated. The side view which shows the airbag module by which the airbag was made into the non-expanding deployment state in one Embodiment. The plane sectional view showing the schematic structure inside the air bag in one embodiment. FIG. 6 is a partial side sectional view showing an internal structure of the airbag module of FIG. 5 together with an occupant and a vehicle seat. The side view which shows the state before the airbag of an airbag module is folded in one Embodiment. It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is a side view, (b) is the rear view seen from the left of said (a). It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is a side view, (b) is the rear view seen from the left of said (a). It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is a side view, (b) is the rear view seen from the left of said (a). It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is the side view seen from the back side of Fig.11 (a), (b) is the right side of said (a) The rear view seen from. It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is a side view, (b) is the sectional view on the AA line of said (a). It is a figure which shows the airbag module of the middle stage in which the airbag in one Embodiment is folded, (a) is a side view, (b) is the BB sectional drawing of the said (a). It is a figure which shows the airbag module by which the airbag in one Embodiment was folded and was made into the accommodation form, (a) is a side view, (b) is CC sectional view taken on the line of said (a). FIG. 5 is a partial plan cross-sectional view showing a state in which the airbag of FIG. The side view which shows the positional relationship of the fold line and folding part in the airbag of one Embodiment. It is a figure corresponding to FIG.11 (b), and is a rear view which shows the modification of the airbag by which the folding part of the 1st front end side (upper end side) was folded in the aspect different from the said embodiment.

Hereinafter, an embodiment of a side airbag device will be described with reference to FIGS.
In the following description, the forward direction of the vehicle is described as forward, and front, rear, upper, lower, left, and right are defined based on the forward direction. In each figure, “front” indicates the front side of the vehicle, “rear” indicates the rear side of the vehicle, “inside” indicates the inside of the vehicle, and “outside” indicates the outside of the vehicle. The vehicle inner side is the side that approaches the center position in the vehicle width direction, and the vehicle outer side is the side that is away from the center position.

Further, it is assumed that an occupant (adult) having a standard physique is seated on the vehicle seat in a predetermined posture (regular posture).
As shown in FIGS. 1 to 3, in the vehicle 10, a vehicle seat 12 is disposed in the vicinity of the vehicle interior of the side wall portion 11. Here, the side wall portion 11 refers to a vehicle constituent member disposed on a side portion of the vehicle 10, and mainly corresponds to a door, a pillar, and the like. For example, the side wall 11 corresponding to the front seat is a front door, a center pillar (B pillar), or the like. The side wall portion 11 corresponding to the rear seat is a rear portion of a side door (rear door), a C pillar, a front portion of a tire house, a rear quarter, and the like.

  The vehicle seat 12 includes a seat cushion (seat portion) 13 and a seat back (backrest) 14 that stands up from the rear side of the seat cushion 13 and whose inclination angle is adjusted by an inclination adjustment mechanism (not shown). ing. The vehicle seat 12 is disposed on the vehicle 10 with the seat back 14 facing forward. The width direction of the vehicle seat 12 arranged in this way matches the vehicle width direction.

  The seat back 14 includes a seat back main body 15 and a pair of side support portions 16 provided on both side portions in the width direction of the seat back main body 15. The seat back body 15 is inclined to the rear side, and supports the upper body of the occupant P from the rear side. Both side support portions 16 protrude forward from the seat back main body 15 and restrict the movement of the upper body of the occupant P seated on the seat cushion 13 in the vehicle width direction.

Next, the internal structure of the side portion outside the vehicle including the side support portion 16 outside the vehicle in the seat back 14 will be described.
A seat frame that forms the skeleton is disposed in the seat back 14. As shown in FIG. 4, a part of the seat frame is disposed on the vehicle outer side portion in the seat back 14, and this portion (hereinafter referred to as “side frame portion 17”) is formed by bending a metal plate. Is formed. A seat pad 18 made of an elastic material such as urethane foam is disposed on the front side of the seat frame including the side frame portion 17. In addition, a hard backboard 19 formed of synthetic resin or the like is disposed on the rear side of the seat frame. Although the seat pad 18 is covered with a skin, the skin is not shown in FIG. The same applies to FIG. 16 described later.

  In the seat pad 18, a storage portion 21 is provided in the vicinity of the vehicle exterior side of the side frame portion 17. The position of the storage portion 21 is an intermediate portion in the vertical direction of the seat back 14 and is in the vicinity of an oblique rear side of the occupant P seated on the vehicle seat 12 (see FIG. 2). The storage unit 21 incorporates an airbag module AM that forms a main part of the side airbag device.

  A slit 22 extends from the corner portion on the vehicle outer side and the front side of the storage unit 21 toward the diagonal front vehicle outer side. A portion sandwiched between the corner 18c on the front side of the seat pad 18 and the slit 22 (a portion surrounded by a two-dot chain line in FIG. 4) constitutes a planned break portion 23 to be broken by the airbag 40 described later. ing.

  The airbag module AM incorporated in the seat back 14 includes an inflator assembly 30 and an airbag 40 as main components. Next, each of these structural members will be described.

<Inflator assembly 30>
The inflator assembly 30 includes an inflator 31 as a gas generator and a retainer 32 that covers the inflator 31. In the present embodiment, a type called a pyro type is employed as the inflator 31. The inflator 31 has a substantially cylindrical shape, and a gas generating agent (not shown) that generates an expansion gas is accommodated therein.

  As the inflator 31, instead of the pyro type using the gas generating agent, a type (hybrid type) in which a partition wall of a high pressure gas cylinder filled with a high pressure gas is broken with an explosive or the like to eject an expansion gas is used. May be.

  On the other hand, the retainer 32 is a member having a function of fastening the inflator 31 to the side frame portion 17 together with the airbag 40 while functioning as a diffuser for controlling the direction in which the inflation gas is ejected. Most of the retainer 32 is formed in a substantially cylindrical shape extending in a substantially vertical direction by bending a plate material such as a metal plate. The retainer 32 is provided with a communication portion (not shown) that communicates the inside and the outside of the retainer 32, and most of the inflation gas ejected from the inflator 31 is ejected to the outside of the retainer 32 through the communication portion.

Bolts 34 are fixed to the retainer 32 as locking members for attaching the retainer 32 to the side frame portion 17.
The inflator assembly 30 may be one in which the inflator 31 and the retainer 32 are integrated.

<Airbag 40>
As shown by a two-dot chain line in FIGS. 1 to 3, the airbag 40 has an inflation gas from the inflator 31 when an impact is applied to the side wall portion 11 due to a side collision or the like while the vehicle 10 is traveling. It expands and expands upon receiving the supply, and jumps forward from the seat back 14 in a state where a part of itself is left in the seat back 14.

  FIG. 5 shows the airbag module AM in a state where the airbag 40 is deployed in a planar shape without being filled with the inflation gas (hereinafter referred to as “non-inflated and deployed state”). 7 shows the airbag module AM in which the airbag 40 in the non-inflated and deployed state of FIG. 5 is cut at the center in the vehicle width direction to show the internal structure of the airbag module AM. 12 is shown.

  As shown in FIGS. 5 to 7, the airbag 40 is formed by folding a single piece of cloth (also called a base cloth, a panel cloth, etc.) into two along a fold line 42 set at the center thereof. It is formed by overlapping in the direction and joining the overlapped portions so as to form a bag shape. Here, in order to distinguish the two overlapped portions of the airbag 40, the one located on the inside of the vehicle is referred to as the cloth portion 43, and the one located on the outside of the vehicle is referred to as the cloth portion 44. Each cloth part 43 and 44 has comprised the shape elongated in the up-down direction rather than with respect to the front-back direction.

  In this embodiment, the cloth piece is folded in two so that the fold line 42 is positioned at the rear end of the airbag 40. However, the fold line 42 has other ends such as a front end, an upper end, and a lower end. The cloth piece may be folded in half so as to be located at the part or the like. Further, the airbag 40 may be composed of two pieces of cloth divided along the fold line 42. In this case, the airbag 40 is formed by superimposing two pieces of cloth in the vehicle width direction and connecting the two pieces of cloth so as to form a bag shape. Further, the airbag 40 may be composed of three or more pieces of cloth.

  In the airbag 40, the outer shapes of the cloth portions 43 and 44 are in a line-symmetric relationship with each other with the folding line 42 as the axis of symmetry. The shape and size of each of the cloth portions 43 and 44 is such that the upper body of the occupant P seated on the vehicle seat 12 when the airbag 40 is deployed and inflated between the vehicle seat 12 and the side wall portion 11. Is set so as to be able to occupy a region corresponding to a region from the chest PT to the head PH (FIGS. 1 to 3). As shown in FIG. 7, the airbag 40 is formed such that a front end 40a of a place on the side of the head PH of the occupant P is positioned in front of a front end 40b of a place on the side of the chest PT. ing.

  As both the cloth portions 43 and 44, a woven fabric formed using a material having high strength and flexibility and can be easily folded, for example, polyester yarn, polyamide yarn or the like is suitable. .

  The above-described connection between the cloth parts 43 and 44 is performed at a peripheral connection part 45 provided at the peripheral part thereof. In the present embodiment, most of the peripheral edge coupling portion 45 sews (sews with a sewing thread) a portion other than the rear end portion (the vicinity of the folding line 42) of the peripheral portions of the cloth portions 43 and 44. It is formed by. The point that it is formed by this sewing is the same for the outer coupling portion 52 and the inner coupling portion 53 described later.

  Regarding the above sewing, in FIGS. 5, 7 to 15, and 17, the sewing portion is expressed by three line types. The first line type is a line (a kind of broken line) expressed by arranging a certain length of thick lines intermittently (a type of broken line), which shows a state where the stitched portion is viewed from the side (the peripheral edge in FIG. 5). (Refer to the coupling part 45 etc.). The second line type is a line (a type of broken line) in which fine lines of a certain length (longer than a general broken line) are intermittently arranged, which is located between the cloth portions 43 and 44. The state of the sewing thread that cannot be directly seen (hidden) is shown (see the inner coupling portion 53 in FIG. 5). The third line type is a line (a type of broken line) in which points are arranged at regular intervals, and this shows a cross section of the suture thread that stitches the cloth portions 43 and 44 (periphery in FIG. 7). (Refer to the coupling part 45 etc.).

  As shown in FIG. 5 to FIG. 7, the space between the cloth portions 43 and 44 and surrounded by the peripheral edge coupling portion 45 is expanded and expanded on the side of the upper body of the occupant P by the inflation gas. It is an inflating part for restraining a part from the chest PT to the head PH and protecting it from an impact.

  In addition, the periphery coupling | bond part 45 may be formed by the means different from the sewing using the said sewing thread, for example, adhesion | attachment using an adhesive agent. The same applies to the outer coupling portion 52 and the inner coupling portion 53 which will be described later.

  A partition wall 50 extending substantially in the vertical direction is provided in an intermediate portion of the airbag 40 in the front-rear direction, and the airbag 40 is the same as the rear expansion chamber 46 on the rear side of the partition wall 50. It is partitioned into a front expansion chamber 47 on the front side of the partition wall 50. The partition wall 50 has the same configuration as that generally called a tether.

<Division wall 50>
The partition wall 50 includes a pair of cloth pieces 51 made of a material that has high strength and is flexible and can be easily folded, for example, a woven cloth similar to the cloth portions 43 and 44. ing. Both pieces of cloth 51 have a strip shape elongated in the vertical direction. Each cloth piece 51 is connected to the opposite one of the cloth parts 43 and 44 of the airbag 40 by an outer connecting part 52 extending substantially vertically along the rear edge. The both outer coupling parts 52 are cloth parts 43 and 44 corresponding to the rear end part of the cloth piece 51 at the side of the intermediate part in the front-rear direction of the upper body of the occupant P when the airbag 40 is inflated. Is bound to. Both cloth pieces 51 are coupled to each other by an inner coupling portion 53 extending substantially vertically along their front end edges.

  In this manner, the partition wall 50 formed of the pair of cloth pieces 51 is bridged between the cloth portion 43 on the inside of the vehicle and the cloth portion 44 on the outside of the vehicle in the airbag 40. The partition wall 50 is overlaid in the vehicle width direction when the airbag 40 is not inflated and deployed (see FIGS. 5 and 7). Further, the partition wall 50 is in a state of being tensioned in the vehicle width direction as the airbag 40 is inflated (see FIG. 6), and regulates the thickness (expansion thickness) of the airbag 40 in the vehicle width direction.

  In the partition wall 50, an upper communication hole 54 that allows the rear expansion chamber 46 and the front expansion chamber 47 to communicate with each other is provided at a location on the side of the head PH of the occupant P when the airbag 40 is inflated. . Further, in the partition wall 50, a lower communication hole 55 that allows the rear inflation chamber 46 and the front inflation chamber 47 to communicate with each other is provided at a location that is lateral to the chest PT of the occupant P when the airbag 40 is inflated. Yes. More specifically, the inner coupling portion 53 is decoupled at two locations, the upper end portion and the lower portion thereof. At the upper end and the lower part in the vertical direction, the inner coupling portion 53 that couples the cloth pieces 51 is not provided. A location where the coupling is released at the upper end of the inner coupling portion 53 constitutes the upper communication hole 54, and a location where the coupling is released at the lower portion of the inner coupling portion 53 constitutes the lower communication hole 55. The upper communication hole 54 and the lower communication hole 55 are closed when the cloth pieces 51 are overlapped, and the airbag 40 is inflated and opened when the partition wall 50 is tensioned in the vehicle width direction.

  When the airbag 40 is in a non-inflated and deployed state, that is, when the cloth pieces 51 of the partition wall 50 are overlapped, the vertical length L1 of the lower communication hole 55 is longer than the vertical length L2 of the upper communication hole 54. Is formed. With this configuration, the opening area of the lower communication hole 55 when the airbag 40 is inflated is set larger than the opening area of the upper communication hole 54.

  The most part of the inflator assembly 30 described above is in a posture extending substantially in the vertical direction and is accommodated in the lower portion of the rear end of the rear expansion chamber 46. The bolt 34 of the retainer 32 is inserted through the cloth portion 43 on the inner side of the airbag 40. By this insertion, the inflator assembly 30 is locked in a state of being positioned with respect to the airbag 40.

  Further, the outer fabric portion 44 has an exhaust hole 56 between the upper communication hole 54 and the lower communication hole 55 in the front part of the front expansion chamber 47. In the cloth portion 44, a reinforcing portion 57 is provided around the exhaust hole 56 by sewing with a sewing thread. The reinforcing portion 57 reinforces the periphery of the exhaust hole 56 of the cloth portion 44 and suppresses the portion from tearing or fraying.

  By the way, as shown in FIG.4 and FIG.15 (a), (b), the airbag module AM which has the inflator assembly 30 and the airbag 40 as main components is a compact form because the airbag 40 is folded. (Hereinafter referred to as “storage form”). This is because the airbag module AM is suitable for storage with respect to the storage portion 21 having a limited size in the seat back 14.

  The storage form is obtained by folding the airbag 40 in a non-inflated and deployed state as shown in FIGS. Next, the process of folding the airbag 40 will be described. For the description, the position of the folding lines 42, 61, 64, 67, 71, 74, 75, the position of the part to be folded, the direction of folding, etc. are specified. Is required. Therefore, when specifying the position of the fold line or the position of the part to be folded, each part of the airbag 40 is specified with the inflator assembly 30 as a reference. With respect to the direction along the axis AL of the inflator assembly 30 (substantially in the vertical direction), the end close to the inflator assembly 30 is referred to as “first base end”, and the end far from the inflator assembly 30 is referred to as “first front end”. In a state where the non-inflated and deployed airbag 40 is attached to the vehicle seat 12, the first base end corresponds to the lower end of the airbag 40, and the first distal end corresponds to the upper end of the airbag 40. To do.

  The same applies to a direction (substantially front-rear direction) orthogonal to the axis AL of the inflator assembly 30. An end close to the inflator assembly 30 is called a “second base end”, and an end far from the inflator assembly 30 is called a “second tip”. In a state where the non-inflated and deployed airbag 40 is attached to the vehicle seat 12, the second base end corresponds to the rear end of the airbag 40, and the second distal end corresponds to the front end of the airbag 40. Equivalent to.

Further, when specifying the folding direction, the terms “vehicle outside” and “vehicle inside” are used on the assumption that the airbag 40 is attached to the vehicle seat 12.
FIG. 8 shows a state in which the airbag 40 in a non-inflated and deployed state in which the folding line 42 and the axis line AL of the inflator assembly 30 extend in the vertical direction is viewed from the outside of the vehicle. In the airbag 40, a fold line 61 orthogonal to the fold line 42 is set at a position slightly away from the inflator assembly 30 to the first tip side (upper end side in FIG. 8). As indicated by an arrow in FIG. 8, in the airbag 40, a portion 62 on the first tip side (the upper end side in FIG. 8) with respect to the fold line 61 extends along the fold line 61 to the outside of the vehicle (front side in FIG. 8). ). By this folding, a part of the portion 62 is overlapped with a part of the portion 63 on the first base end side (lower end side in FIG. 8) with respect to the folding line 61 in the airbag 40. The airbag 40 is configured as shown in FIGS. 9 (a) and 9 (b).

  Next, in the portion 62, a fold line 64 is set in parallel to the fold line 61 at a position away from the fold line 61 to the first tip side (the lower end side in FIG. 9A). As shown by the arrow in FIG. 9A, in the portion 62, a portion 65 on the first tip side (the lower end side of FIG. 9A) from the fold line 64 extends along the fold line 64. It is folded back to the outside of the vehicle (the front side of FIG. 9A). By this folding, a part of the part 65 is overlapped with a part of the airbag 40 sandwiched between the fold line 61 and the fold line 64 (hereinafter referred to as “folding part 66”). The airbag 40 is configured as shown in FIGS. 10 (a) and 10 (b).

  Next, a fold line 67 is set in parallel to the fold line 64 at a position away from the fold line 64 toward the first tip side (the upper end side in FIG. 10A). As indicated by the arrow in FIG. 10 (a), in the portion 65, the portion on the first tip side (the upper end side of FIG. 10 (a)) from the fold line 67 (hereinafter referred to as “folding portion 68”) It folds along the fold line 67 toward the vehicle interior (the back side in FIG. 10A). As a result of the folding, a large part of the folding part 68 is overlapped with a part of the airbag 40 sandwiched between the folding line 64 and the folding line 67 (hereinafter referred to as “folding part 69”). The airbag 40 is configured as shown in FIGS. 11 (a) and 11 (b).

  FIGS. 12A and 12B show the airbag 40 shown in FIGS. 11A and 11B as viewed from the back side, that is, from the vehicle interior side. As shown in FIGS. 12A and 12B, a folding line 71 is set in the portion 63 of the airbag 40 in which the inflator assembly 30 is stored. The fold line 71 is set on the second distal end side (front end side) in the deployment direction of the airbag 40 and in the direction orthogonal to the axis AL of the inflator assembly 30. Here, the fold line 71 is set to be inclined with respect to the axis AL. As shown by an arrow in FIG. 12A, in the portion 63, a portion on the second tip side (obliquely lower left side in FIG. 12A) from the fold line 71 (hereinafter referred to as “folding portion 72”). Then, it is folded back along the folding line 71 toward the vehicle inner side (the front side in FIG. 12A). By this folding, the folding part 72 is overlapped with a part of the part 63 surrounded by the folding line 71, the folding line 42, and the folding line 61 (hereinafter referred to as “folding part 73”). As shown in FIGS. 13A and 13B, the airbag 40 has an intermediate form in which folding portions 69, 68, 66, 73 and 72 are overlapped from the vehicle outer side toward the vehicle inner side.

  Subsequently, as shown in FIGS. 13A and 13B, the second direction is higher than the partition wall 50 (outer coupling portion 52) of the airbag 40 in the intermediate form in the direction orthogonal to the axis AL of the inflator assembly 30. Fold lines 74 are set in parallel to the fold line 42 (axis AL) at a plurality of locations in the front end side (front end side) region Z1. And the said area | region Z1 is folded toward the 2nd base end side (rear end side) from the 2nd front end side (front end side) by the roll fold repeatedly folded in the same direction along each folding line 74. FIG. By this folding, the airbag 40 has the form shown in FIGS. 14 (a) and 14 (b).

  Next, as shown in FIGS. 14A and 14B, the second base end side of the partition wall 50 (outer coupling portion 52) of the airbag 40 that is roll-folded in the direction orthogonal to the axis AL. Fold lines 75 are set in parallel to the fold line 42 (axis AL) at a plurality of locations in the (rear end side) region Z2. Then, the region Z2 is folded from the second distal end side (front end side) to the second proximal end side (rear end side) by bellows folding in which folding directions are alternately changed along the folding lines 75. It is. By this folding, the airbag 40 becomes the storage configuration shown in FIGS. 15 (a) and 15 (b).

  Thus, the airbag module AM in which the airbag 40 is folded and stored is in a direction (substantially front-rear direction) perpendicular to the direction along the axis AL of the inflator assembly 30 (substantially up-down direction). In addition, the size is small, and it is suitable for storing the narrow storage portion 21 of the seat back 14.

  As shown in FIG. 4, in the airbag module AM configured to be stored, the bolt 34 that extends from the retainer 32 and is inserted into the airbag 40 (cloth portion 43) is inserted into the side frame portion 17. Then, the nut 35 is fastened to the bolt 34, whereby the inflator assembly 30 is fixed to the side frame portion 17 together with the airbag 40.

Note that the inflator assembly 30 may be fixed to the side frame portion 17 by a member different from the bolt 34 and the nut 35 described above.
As shown in FIG. 1, the side airbag device includes an impact sensor 81 and a control device 82 in addition to the above-described airbag module AM (see FIG. 2). The impact sensor 81 is composed of an acceleration sensor or the like, and is provided on the side wall 11 (see FIG. 2) of the vehicle 10, and detects an impact applied to the side wall 11 from the side. The control device 82 controls the operation of the inflator 31 based on the detection signal from the impact sensor 81.

  Further, the vehicle 10 is equipped with a seat belt device for restraining the occupant P seated on the vehicle seat 12 to the vehicle seat 12, but in FIG. It is omitted.

Next, the operation of the side airbag device of the present embodiment configured as described above will be described.
In this side airbag device, when no impact is applied from the side to the side wall 11 of the vehicle 10 due to a side collision or the like, an operation signal for operating this is not output from the control device 82 to the inflator 31. The inflation gas is not supplied from the inflator 31 to the airbag 40. The airbag module AM continues to be stored in the storage portion 21 in the storage form (see FIG. 4).

  On the other hand, when the vehicle is traveling, an impact of a predetermined value or more is applied from the side to the side wall portion 11 due to a side collision or the like, and when this is detected by the impact sensor 81, the control device 82 is based on the detection signal. To the inflator 31, an operation signal for operating it is output. In response to this operation signal, in the inflator 31, the gas generating agent generates a high-pressure inflation gas and ejects it. The blown inflation gas is supplied to the airbag 40 through the communicating portion of the retainer 32. Here, the airbag 40 is partitioned into a rear inflating chamber 46 and a front inflating chamber 47 by a partition wall 50 provided at an intermediate portion in the front-rear direction. An assembly 30 is arranged. Therefore, the expansion gas from the inflator 31 is supplied to the lower portion of the rear end in the rear expansion chamber 46.

  As shown in FIG. 17, the inflating gas flows in the rear expansion chamber 46 from the folding part 73 near the inflator assembly 30 toward the folding parts 68 and 72 far from the inflator assembly 30. In other words, the inflation gas moves upward in the rear expansion chamber 46 from the first proximal end (lower end side) folding portion 73 in the deployment direction toward the first distal end side (upper end side) folding portion 68. To flow. The expansion gas flows forward in the rear expansion chamber 46 from the second proximal end (rear end) folding portion 73 in the deployment direction toward the second distal end (front end) folding portion 72. . The first base end side and second base end side folding portions 73 are folding portions in which the inflator assembly 30 is accommodated.

  When the expansion gas that flows forward from the second base end side toward the folding portion 72 on the second front end side reaches the partition wall 50, the flow direction is changed upward along the partition wall 50, and from the beginning upward. Join the flowing inflation gas.

Due to the upward expansion gas, the rear expansion chamber 46 expands while releasing (deploying) the folds sequentially from the bottom to the top.
In addition, the bellows-folded region Z2 (see FIG. 14) of the airbag 40 that is rearward of the partition wall 50 in the airbag 40 is canceled (deployed) in order from the rear toward the front. While expanding.

  As described above, the seat pad 18 of the seat back 14 is pressed by the airbag 40 in the process of expanding and inflating the airbag 40 upward and forward, and is broken at the planned breaking portion 23 in FIG. As shown in FIG. 16, the airbag 40 jumps out from the seat back 14 to the front of the vehicle 10 in a state where the rear end portion of the airbag 40 is left in the storage portion 21 together with the inflator assembly 30.

The expansion gas expands the rear portion of the second distal end side (front end side) folding portion 72 relative to the partition wall 50.
Here, the bellows fold has a feature that the folded state can be easily eliminated. Therefore, the bellows-folded region Z2 behind the partition wall 50 is rapidly expanded and expanded forward.

  Further, the volume of the rear expansion chamber 46 is smaller than the volume of the airbag 40 when the airbag 40 is not partitioned by the partition wall 50. The expansion thickness of the rear expansion chamber 46 in the vehicle width direction is smaller than the expansion thickness of the airbag 40 in the vehicle width direction when the airbag 40 is not partitioned. Therefore, the rear expansion chamber 46 is easy to expand and expand while passing through a narrow gap.

  As shown in FIGS. 7 and 17, a part of the inflation gas that flows upward in the rear expansion chamber 46 and reaches the rear side of the chest portion PT of the occupant P passes through the lower communication hole 55 and passes through the front expansion chamber. It flows into the lower part of 47. Further, a part of the inflation gas that flows through the rear expansion chamber 46 upward from the lower communication hole 55 without passing through the lower communication hole 55 and reaches the rear side of the head PH of the occupant P It flows into the upper part of the front expansion chamber 47 through the communication hole 54. At this time, since the opening area of the lower communication hole 55 is larger than the opening area of the upper communication hole 54, a larger amount of inflation gas flows in the lower communication hole 55 than in the upper communication hole 54.

  Part of the expansion gas that has flowed into the front expansion chamber 47 through the lower communication hole 55 changes its direction upward and downward. Further, a part of the expansion gas that has flowed into the front expansion chamber 47 through the upper communication hole 54 changes its direction downward.

  With these inflation gases, the roll-folded portion in front of the partition wall 50 expands and expands forward on the front side of the chest PT and the head PH. At this time, as described above, the flow rate of the expansion gas is different between the lower communication hole 55 and the upper communication hole 54. In particular, it is unlikely to expand and expand earlier than the side of the chest PT, that is, to expand and expand before passing through a narrow space between the shoulder PS of the occupant P and the side wall 11 of the vehicle. . A portion that is to be expanded and expanded on the front side of the head PH expands and expands after passing through a narrow portion between the shoulder portion PS and the side wall portion 11. As a result, a portion of the airbag 40 that is planned to be deployed and inflated on the side of the head PH of the occupant P becomes difficult to pass through the narrow gap portion, thereby inhibiting the deployment and inflation of other portions. Is unlikely to occur. The airbag 40 is deployed and inflated on the side of the region from the chest PT of the occupant P to the head PH.

  Further, the roll fold has a feature that it is easy to expand along the side wall 11 of the vehicle 10. Therefore, the roll-folded portion in front of the partition wall 50 expands and expands forward along the side wall portion 11 of the vehicle on the front side of the chest portion PT and the head portion PH of the occupant P.

  The expansion gas that has flowed into the front expansion chamber 47 through the lower communication hole 55 and changed its direction downward is supplied to the front portion of the folding wall 72 on the second front end side (front end side) relative to the partition wall 50. Then, the state of folding back to the vehicle inner side of the folding portion 72 is canceled (deployed). During this expansion, the folding portion 72 does not contact the side wall portion 11 of the vehicle, and it is difficult for smooth expansion to be hindered by friction with the side wall portion 11. In addition, since the front portion of the folding portion 72 relative to the partition wall 50 is pushed by the rear portion of the partition wall 50 that has started to expand as described above, the unfolding is performed quickly.

  When a part of the inflation gas flowing upward in the rear expansion chamber 46 reaches the folding portion 68 on the first tip side (upper end side), the state in which the folding portion 68 is folded back to the vehicle inner side is resolved (deployment). ) During this expansion, the folding portion 68 does not contact the side wall portion 11 of the vehicle 10, and it is difficult for smooth expansion to be hindered by friction with the side wall portion 11.

  As shown in FIG. 7, when the airbag 40 has been deployed and inflated, the front end 40a of the location on the side of the head PH of the occupant P is ahead of the front end 40b of the location on the side of the chest PT. Located in. Therefore, compared with what is located in the same location as the front end 40b of the airbag 40, or located in back, the area | region expand | deployed and expand | swelled in the side of the head PH among airbags 40 becomes wide ahead.

  By the way, if the upper communication hole 54 is positioned in a fold part different from the uppermost fold part 68, for example, the fold part 69, the inflation gas flows into the front expansion chamber 47 through the upper communication hole 54. There is a risk that the front expansion chamber 47 is inflated, and the expansion and expansion of the folding portion 68 performed after that is hindered.

  In this respect, in the present embodiment, since the upper communication hole 54 is located in the uppermost folding part 68, the expansion gas in the rear expansion chamber 46 is allowed to flow into the upper communication hole in the process of the folding part 68 expanding. It flows into the front expansion chamber 47 through 54. Therefore, it is difficult for the upper communication hole 54 to hinder the expansion and expansion of the folding portion 68.

  The airbag 40 deployed and inflated as described above is interposed between the occupant P and the side wall portion 11 entering the vehicle interior, as shown by a two-dot chain line in FIGS. 2 and 3. Is pushed directly into the vehicle and restrained, and the side impact transmitted to the occupant P through the side wall 11 is reduced.

  The inflation gas that has flowed into the upper portion of the front expansion chamber 47 through the upper communication hole 54 and turned downward is discharged to the outside of the airbag 40 (outside the fabric portion 44) through the exhaust hole 56. Is done. The impact from the side transmitted to the passenger | crew P through the side wall part 11 is relieve | moderated by the internal pressure fall accompanying exhaust_gas | exhaustion of this gas for expansion | swelling. Further, since the expansion gas that has expanded and expanded the upper part of the front expansion chamber 47 as described above is discharged from the exhaust hole 56, the expansion gas is located below the exhaust hole 56. The flow to the lower part of is suppressed. As a result, the lower portion of the front expansion chamber 47 is prevented from being expanded and expanded by excessive pressure on the side of the chest PT.

According to the embodiment described in detail above, the following effects can be obtained.
(1) The airbag 40 is deployed and expanded between the portion from the chest PT to the head PH of the occupant P seated on the vehicle seat 12 and the side wall 11 of the vehicle 10 by the inflation gas from the inflator 31. In the side airbag device that is inflated, the folding portions 68 and 72 at the front end in the deployment direction of the airbag 40 are folded back toward the vehicle interior (FIG. 12).

  Therefore, the folding parts 68 and 72 can be prevented from coming into contact with the side wall part 11 of the vehicle 10 when the folded state is canceled (deployed), and the folding parts 68 and 72 can be smoothly deployed.

  (2) The airbag 40 is folded from the upper side to the lower side so that a plurality of folding parts 66, 68, 69, 73 are formed, and deployed and inflated from the lower side to the upper side (FIG. 17). . Then, the folded portion 68 at the upper end of the airbag 40 is folded back toward the inside of the vehicle as a folded portion at the distal end in the deployment direction (FIGS. 11A and 11B).

Therefore, the effect (1) can be obtained in the case where the folded portion 68 at the upper end of the airbag 40 is folded back toward the vehicle interior side.
(3) The airbag 40 is partitioned by a partition wall 50 extending substantially in the vertical direction into a front expansion chamber 47 and a rear rear expansion chamber 46 on the front side of the partition wall 50, and an inflator is provided below the rear expansion chamber 46. 31 is arranged. An upper communication hole 54 for communicating the rear expansion chamber 46 and the front expansion chamber 47 is provided at a location on the side of the head PH of the occupant P in the partition wall 50. A lower communication hole 55 for communicating the rear expansion chamber 46 and the front expansion chamber 47 is provided at a location (FIG. 7). Of the plurality of folding portions 66, 68, 69, 73 formed by folding the airbag 40 from above to below, the region Z1 in front of the partition wall 50 is folded from the front to the back by roll folding. (FIGS. 13A and 13B), the region Z2 on the rear side of the partition wall 50 is folded from the front to the back by bellows folding (FIGS. 14A and 14B).

  Therefore, the portion of the bellows folded behind the partition wall 50 is quickly expanded and expanded forward on the rear side of the chest PT or the head PH of the occupant P, so that the above-mentioned portion of the occupant P is quickly Can be restrained and protected. Further, the roll-folded portion ahead of the partition wall 50 is expanded and inflated forward along the side wall portion 11 of the vehicle on the front side of the chest PT and the head PH of the occupant P. The said site | part can be restrained and protected exactly.

  (4) The lower portion of the airbag 40 is folded from the front to the rear so that the folded portions 72 and 73 are formed, and the deployment and the expansion are performed from the rear to the front. And the folding part 72 of the lower front end of the airbag 40 is turned inside the vehicle as a folding part at the front end in the deploying direction (FIG. 12A).

Therefore, the effect (1) can be obtained in the case where the folded portion 72 at the lower front end of the airbag 40 is folded back toward the vehicle interior side.
(5) The airbag 40 is partitioned into a front expansion chamber 47 and a rear expansion chamber 46 on the front side of the partition wall 50 by a partition wall 50 extending substantially in the vertical direction, and an inflator is provided below the rear expansion chamber 46. 31 is arranged. A lower communication hole 55 that allows the rear expansion chamber 46 and the front expansion chamber 47 to communicate with each other is provided at a location on the side of the chest PT of the occupant P in the partition wall 50 (FIG. 7). Further, the folded portion 72 at the lower front end of the airbag 40 is folded back in a state of intersecting the partition wall 50 (outer coupling portion 52) (FIG. 12A).

  Therefore, the front part of the folding part 72 at the lower front end can be pushed by the rear part of the partition wall 50 which has started to expand first, and can be rapidly deployed.

In addition, the said embodiment can also be implemented as a modification which changed this as follows.
The opening area of the lower communication hole 55 may be set to the same size as the opening area of the upper communication hole 54. Even in this case, the same effect as the above embodiment can be obtained.

The exhaust hole 56 may be formed in a shape different from a circle, for example, a slit shape.
The inflator 31 may be directly attached to the side frame portion 17 without using the retainer 32.

  The airbag 40 may be substantially inflated as in the above embodiment, but has a non-inflatable portion that does not inflate without being supplied with the inflation gas. Also good.

  -A part of folding part 68 of the 1st front end side (upper end side) in Fig.10 (a) may be further bend | folded inside a vehicle. FIG. 18 shows an example. In this case, for example, with respect to the folding portion 68 in FIG. 10A, the folding line 68 is folded in parallel to the folding line 67 at a position away from the folding line 67 to the first tip side (the upper end side in FIG. 10A). 77 is set. As shown in FIG. 10 (a), in the folding portion 68, a portion on the first tip side (the upper end side of FIG. 10 (a)) from the folding line 77 (hereinafter referred to as “folding portion 78”) The vehicle is folded back along the folding line 77 toward the vehicle interior (the back side in FIG. 10A). By this folding, many portions of the folding portion 78 are overlapped with many portions of the airbag 40 sandwiched between the folding line 67 and the folding line 77 (hereinafter referred to as “folding portion 79”).

  Even in this case, when the folded portion 78 located on the first front end side (upper end side) expands while canceling (expanding) the state where the folded portion 78 is folded back toward the vehicle inner side, the folded portion 78 is The side wall 11 is not in contact with the side wall 11, and it is difficult for smooth development to be hindered by friction with the side wall 11.

-The lower part of the airbag 40 may be folded twice or more from the front to the back so that three or more folding parts are formed.
-The folding from the second front end side (front end side) of the airbag 40 toward the second base end side (rear end side) does not stop at the lower part of the airbag 40 but to the upper part including the lower part. May be performed.

  -Folding from the first front end side (upper end side) of the airbag 40 toward the first base end side (lower end side) and folding from the second front end side (front end side) toward the second base end side (rear end side). Either one of them may be omitted.

-The partition wall 50 may be comprised by one piece of cloth.
-It replaces with the seat back 14 of the vehicle seat 12, and the location equivalent to the accommodating part 21 is provided in the side wall part 11, and the airbag module AM may be integrated here.

  -Vehicles to which the side airbag device is applied include not only private vehicles but also various industrial vehicles.

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11 ... Side wall part, 12 ... Vehicle seat, 31 ... Inflator, 40 ... Air bag, 46 ... Rear expansion chamber, 47 ... Front expansion chamber, 50 ... Partition wall, 54 ... Upper communication hole, 55 ... Lower part Communication hole, 66, 68, 69, 72, 73 ... folding part, P ... occupant, PH ... head, PT ... chest, Z1, Z2 ... region.

Claims (5)

An inflator that is placed near the side of the chest of an occupant seated in a vehicle seat and that blows inflating gas in response to an impact from the side of the vehicle, and is stored in a folded state so that a plurality of folding parts are formed. A side airbag device comprising an airbag that is deployed and inflated between a portion of the occupant from the chest to the head and a side wall portion of the vehicle by the inflation gas from the inflator;
The side airbag device according to claim 1, wherein a folded portion at a tip end in the deployment direction of the airbag is folded back toward the vehicle interior side. At least a part of the airbag is folded from the upper side to the lower side so that a plurality of folding parts are formed, and the expansion and the expansion are performed from the lower side to the upper side.
2. The side airbag device according to claim 1, wherein a folded portion at an upper end of the airbag is folded toward the vehicle interior as a folded portion at a tip end in a deployment direction. The airbag is partitioned into a front expansion chamber on the front side and a rear expansion chamber on the rear side of the partition wall by a partition wall extending in a substantially vertical direction,
The inflator is disposed at a lower portion of the rear expansion chamber;
An upper communication hole for communicating the rear expansion chamber and the front expansion chamber is provided at a location on the side of the head of the occupant in the partition wall,
A lower communication hole for communicating the rear expansion chamber and the front expansion chamber is provided at a location on the side of the chest of the occupant in the partition wall,
Of the airbag folded from above to below, the region on the front side of the partition wall is folded from the front to the back by roll folding that is repeatedly folded in the same direction, and is behind the partition wall. The side airbag device according to claim 2, wherein the region is folded from the front to the back by bellows folding in which the folding direction is alternately changed. At least the lower part of the airbag is folded from the front to the rear so that a plurality of folding parts are formed, and the deployment and the expansion are performed from the rear to the front,
The side airbag device according to any one of claims 1 to 3, wherein the folded portion at the lower front end of the airbag is folded toward the vehicle interior as a folded portion at the tip end in the deployment direction. The airbag is partitioned into a front expansion chamber on the front side and a rear expansion chamber on the rear side of the partition wall by a partition wall extending in a substantially vertical direction,
The inflator is disposed at a lower portion of the rear expansion chamber;
A lower communication hole for communicating the rear expansion chamber and the front expansion chamber is provided at a location on the side of the chest of the occupant in the partition wall,
The side airbag device according to claim 4, wherein the folded portion at the lower front end of the airbag is folded in a state of intersecting the partition wall.