JP2008155711A - Airbag device for rear end collision - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an airbag device for rear end collision capable of precisely deploying a non-inflating portion between a headrest and a rear window glass. <P>SOLUTION: In the airbag device for rear end collision, the airbag 32 comes out of a storage space in a roof to an oblique rear-downward direction and deployed and inflated between the rear seat 12 and the rear window glass by a gas injected from the inflator 31 according to a shock from the rear side of the vehicle and flows into an inflation scheduled portion (inflation cells 41-46). In the airbag device for rear end collision, the non-inflating portions 48, 49 not inflated by the gas are provided at the part corresponding to the headrests 14, 14 of the airbag 32. Furthermore, when the non-inflating portions 48, 49 are deployed associated with the deployment and inflation of the inflation scheduled portions (inflation cells 41-46), a deployment assist inflating cell 50 is provided on the upper part of respective non-inflating portions 48, 49 as a deployment assist portion for guiding the non-inflating portions 48, 49 to the rear side of the headrests 14, 14 to assist the deployment. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rear impact airbag that protects an occupant by deploying and inflating an airbag housed in a rear end of a roof between a rear seat and a rear window glass when an impact is applied to the vehicle from the rear. It relates to the device.

  The rear impact airbag device includes an inflator and an airbag, as with other airbag devices. In this rear-impact airbag device, the airbag is stored in a storage space in the rear end portion of the roof of the vehicle and above the rear window glass in a folded state. When an impact is applied to the vehicle from behind, the inflator is activated and gas is ejected into the airbag. With this gas, the airbag is deployed and inflated from the storage space between the rear seat and the rear window glass obliquely rearward and lower, thereby protecting the occupant from the impact.

  As one form of such a rear-impact airbag device, for example, in Patent Document 1, a cylindrical lateral expansion cell oriented in the vehicle width direction in an expanded and inflated state is formed in a plurality of stages in the vertical direction in the airbag. In addition, there is described a non-inflatable portion that is not inflated by gas at a location corresponding to the headrest of the rear seat in the airbag.

According to the rear impact airbag device, the plurality of stages of lateral inflation cells are deployed and inflated outward in the vehicle width direction, so that a deployment failure of the airbag in the vehicle width direction is prevented, and passenger protection performance is improved. Further, the formation of the non-inflatable portion reduces the volume of the airbag in the expanded and inflated state, thereby reducing the capacity of the inflator and reducing the cost. Furthermore, the deployment and inflation speed of the airbag is increased, and the occupant protection performance is also improved in this respect.
JP 2004-284423 A

  By the way, in the airbag apparatus for rear impacts which provided the non-expanding part in the airbag as mentioned above, since the non-inflating part is not inflated with gas, it cannot be deployed only by itself. The non-inflatable part is pulled and deployed in accordance with the deployment and inflation of other portions of the airbag. However, although the lateral expansion cell can improve the deployment performance of the airbag in the vehicle width direction outside, the force for pulling the non-inflatable portion obliquely rearward and downward is small, and the non-inflatable portion is formed with the headrest and the rear window glass. There is room for improvement in order to develop it accurately.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a rear-impact airbag device capable of accurately deploying a non-inflatable portion between a headrest and a rear window glass. There is.

  In order to achieve the above-mentioned object, the invention according to claim 1 folds an airbag in which a portion to be inflated is formed, and the foremost end for folding the airbag is the rear end of the headrest of the rear seat. The airbag is accommodated in a storage space in a rear end portion of a roof of a vehicle so as to be on the front side, and is ejected from an inflator in response to an impact from the rear of the vehicle and flows into the inflated portion The airbag device for rear impact, wherein the airbag is taken out obliquely rearward and downward from the storage space, and deployed and inflated between the rear seat and the rear window glass, corresponding to the headrest of the airbag. In the portion to be provided with a non-expandable portion that does not expand due to the gas, and during the expansion of the non-expandable portion accompanying the expansion and expansion of the expected expansion portion It led to the non-inflatable portion to the rear side of the headrest and gist in that a development auxiliary portion for assisting the expansion.

  According to said structure, the airbag is accommodated in the state folded by the accommodation space in the rear-end part of the roof in a vehicle at the time of non-operation of the airbag apparatus for rear collisions. In this stored state, the foremost end relating to the folding of the airbag is located in front of the rear end of the headrest.

  When gas is ejected from the inflator in response to an impact from the rear of the vehicle, the gas flows into the planned inflation portion of the airbag in the stored state. Due to this gas inflow, at least a part of the expansion-expected portion exits obliquely rearward and downward from the storage space, and expands and expands between a portion of the rear seat where there is no headrest and the rear window glass. The non-inflatable part, which does not directly flow in gas and cannot be deployed only by itself, is pulled by the expected expansion part that expands and expands as described above, and exits obliquely rearward and downward from the storage space to between the headrest and the rear window glass. Try to expand. At this time, the headrest is located in the vicinity of the deployment path of the non-expanded portion, and can hinder the deployment of the non-expanded portion.

  However, in the invention according to the first aspect, the expansion assisting portion is provided, and the expansion of the non-inflatable portion is assisted by the expansion assisting portion. With this assistance, when the non-expanded portion is deployed as the planned expansion portion expands, the non-expanded portion is guided to the rear side of the headrest. Therefore, the non-inflatable portion is accurately deployed between the headrest and the rear window glass without being deployed on the front side of the headrest or being caught by the headrest.

  The invention according to claim 2 is the invention according to claim 1, wherein the expansion assisting portion is provided at an upper portion of the non-expanding portion, and expands and expands at least obliquely backward and downward by the gas from the inflator, and The gist of the invention is that the lower end of its own is constituted by a deployment auxiliary expansion cell that displaces to the rear side of the top of the headrest during its expansion.

  According to the above configuration, when the expansion portion is expanded and expanded by the gas ejected from the inflator, in addition to the expansion portion, the gas also flows into the expansion auxiliary expansion cell provided on the upper portion of the non-expanded portion. To do. By this inflow, the expansion assisting expansion cell expands and expands obliquely rearward and downward prior to the expansion of the non-expanding portion, and the lower end of the expansion assisting expansion cell is displaced rearward from the top of the headrest with the expansion. By this expansion assisting expansion cell, a portion in the vicinity of the expansion assisting expansion cell in the non-inflatable portion is pulled and guided to the rear side of the top of the headrest. After that, the non-expandable portion is pulled obliquely rearward and downward by the expected expansion portion that expands and expands, and reliably expands behind the headrest.

  According to a third aspect of the present invention, in the first or second aspect of the invention, a portion of the inflated portion is formed outside the non-inflatable portion in the vehicle width direction in the airbag. The side vertical expansion cell that expands and expands obliquely backward and downward through the outer side of the headrest from the position higher than the headrest is partitioned and formed adjacent to the non-expanded portion by the gas from the inflator. The gist.

  According to the above configuration, when the expected expansion portion is expanded and expanded by the gas ejected from the inflator, at least a part of the gas flows into the side vertical expansion cell. Due to this inflow, the side vertical expansion cell expands and expands obliquely backward and downward from the position higher than the headrest through the outside of the headrest. By this side vertical expansion cell, the non-expandable portion is pulled obliquely rearward and downward, and is reliably deployed on the rear side of the headrest.

  According to a fourth aspect of the present invention, in the invention of the third aspect, the side longitudinal expansion cell is inclined so as to be positioned outward in the vehicle width direction toward the lower side in the expanded state. The gist.

  According to the above configuration, the side vertical expansion cell expands and expands obliquely outward and downward on the outer side in the vehicle width direction of the non-expandable portion due to the inflow of gas from the inflator. For this reason, the expansion of the side vertical expansion cell causes the non-expanded portion to be pulled obliquely outward and downward as well as obliquely outward and downward, and the non-expanded portion is more reliably deployed.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, a portion of the inflated portion is arranged inside the airbag in the vehicle width direction inside the non-inflatable portion. An intermediate vertical expansion cell that expands and expands obliquely rearward and downward from the position higher than the headrest through the inner side of the headrest by the gas from the inflator is formed adjacent to the non-expanded portion. It is a summary.

  According to the above configuration, when the expected expansion portion is expanded and expanded by the gas ejected from the inflator, at least a part of the gas flows into the intermediate vertical expansion cell. By this inflow, the middle part vertical expansion cell expands and expands obliquely backward and downward from a position higher than the headrest through the inside of the headrest. The non-inflatable portion is pulled obliquely rearward and downward by the deploying and expanding intermediate portion longitudinal expansion cell, and is reliably deployed on the rear side of the headrest.

  According to a sixth aspect of the present invention, in the first aspect of the invention, the non-expanded portion and the expected expansion portion are partitioned at a joint portion that joins the front overlapping portion and the rear overlapping portion to each other. Further, the gist of the present invention is that the joint part that defines and forms the non-expanded part is set as the expansion assisting part on the rear side of the intermediate part in the front-rear direction with respect to the expansion expected part in the expanded state.

  According to the above configuration, the non-inflatable part is pulled by the expansion-expanding part that expands and inflates, and comes out obliquely rearward and downward from the storage space to expand between the headrest and the rear window glass. The joint that partitions and functions as a deployment assisting portion. That is, the expansion | deployment auxiliary | assistance part which consists of this junction part is set to the back side rather than the front-back direction intermediate | middle part about the expansion | swelling planned part of an expansion | deployment expansion state. For this reason, compared with the case where the expansion assisting portion is set at the front-rear direction intermediate portion of the expected expansion portion or the front side thereof, the expansion assisting portion is pulled by the expected expansion portion on the rear side. As a result, the non-inflatable portion is surely developed downward on the rear side of the headrest without being obstructed by the headrest.

  According to the rear impact airbag device of the present invention, the airbag is provided with the non-inflatable portion at the portion corresponding to the headrest of the rear seat and the deployment assisting portion for assisting the deployment of the non-inflated portion. The unexpanded portion can be accurately deployed between the headrest and the rear window glass with the expansion.

  Hereinafter, an embodiment in which the present invention is embodied in a rear-impact airbag device installed in a vehicle will be described with reference to the drawings. In the following description, it is assumed that the traveling direction (forward direction) of the vehicle is the front, the backward direction is the rear, and the height direction is the vertical direction. Moreover, about the vehicle width direction (left-right direction), the left-right direction is prescribed | regulated on the basis of the case where a vehicle is seen from back.

  First, the configuration of the rear part of the vehicle, which is a place where the rear-impact airbag device is mounted, will be described. As shown in at least one of FIGS. 1 to 3, a pair of left and right rear seats 12, 12 are disposed in the rear portion of the passenger compartment 11 as the last row of seats. In each rear seat 12, a headrest 14 for supporting the head Ph of the occupant P from the rear side is attached to the upper side of the seat back (backrest portion) 13 in the same manner as a general seat.

  Rear pillars (so-called C pillars) 15, 15 extending substantially in the vertical direction are provided on the left and right sides of the rear portion of the vehicle 10. Both the rear pillars 15 and 15 are inclined so that the interval (the left-right width) gradually increases from the upper end toward the lower side.

  As shown in at least one of FIGS. 4 and 5, the surface of each rear pillar 15 on the vehicle compartment 11 side is covered with a rear pillar garnish 16. In each rear pillar garnish 16, fixing clips 17 are provided at a plurality of locations on the surface facing the rear pillar 15, while mounting holes 18 are formed at a plurality of locations on the rear pillar 15. The rear pillar garnish 16 is locked to the rear pillar 15 by engaging the fixing clip 17 in the corresponding mounting hole 18. As described above, the rear pillar garnishes 16, 16 locked to the left and right rear pillars 15, 15 gradually increase in distance from the upper end portions 16 a, 16 a toward the lower side, similarly to the rear pillars 15, 15. (See FIG. 7).

  The shape of the rear part of the passenger compartment 11 is defined by the left and right rear pillar garnishes 16 and 16. Since the left and right rear pillar garnishes 16 and 16 are inclined as described above, the space at the rear of the passenger compartment 11 has a substantially trapezoidal shape that becomes wider toward the lower side.

  Further, below each rear pillar garnish 16, a lower garnish 19 that covers a lower portion of the rear portion of the vehicle compartment 11 is disposed. 4 is a seat belt for restraining the occupant P to the rear seat 12.

  In the rear part of the vehicle 10, roofs are provided above the left and right rear pillars 15 and 15 and the rear pillar garnishes 16 and 16. As shown in FIG. 6, the rear portion of the roof 21 includes a roof panel 22 that is an exterior member, a rear roof head lining 23 that is a decorative member, and an inner panel 24. The rear end 22a of the roof panel 22 is bent downward and is lower than other portions.

  A rear door 25 disposed near the rear of the rear seat 12 (see FIG. 1) is mounted on the rear end portion 22a through a hinge mechanism 26 so as to be opened and closed in a substantially vertical direction. The upper half of the rear door 25 is provided with a rear window 27 (see FIG. 2) having a gradually increasing width from the upper end, that is, a substantially trapezoidal shape. It is installed.

  Further, as shown in FIG. 7, the rear roof head lining 23 is made of a flexible material such as synthetic resin, and is located above the upper end portions 16a and 16a of the left and right rear pillar garnishes 16 and 16. It arrange | positions and has covered the rear part of the roof panel 22 (refer FIG. 6) from the downward direction. Further, the left and right side edge portions 23b, 23b of the rear roof head lining 23 are located on the outer side in the vehicle width direction with respect to the both upper end portions 16a, 16a.

  As shown in FIG. 6, the inner panel 24 is disposed between the roof panel 22 and the rear roof head lining 23, and is fixed to the roof panel 22 at least at the front end portion 24b and the rear end portion 24a.

  A weather strip 29 for sealing is attached to the rear end portion 22 a of the roof panel 22 and the rear end portion 24 a of the inner panel 24. The weather strip 29 has a locking piece 29a projecting obliquely rearward and downward, and a rear end 23a of the rear roof head lining 23 is engaged therewith. The engagement strength of the locking piece 29a with the rear roof head lining 23 is such that the engagement state is quickly released by the pressing force applied to the rear roof head lining 23 when an airbag 32 described later is inflated. Is set to

  Between the roof panel 22 (inner panel 24) and the rear roof head lining 23, in front of the headrest 14 (see FIG. 1) and at the upper ends 16a, 16a of the left and right rear pillar garnishes 16, 16 (see FIG. 7). An inflator 31 that generates gas and an air bag 32 that is deployed and inflated by this gas are disposed in the space between the reference). The inflator 31 and the airbag 32 constitute the main part of the rear impact airbag device. The space is located obliquely forward and upward with respect to the headrest 14 of the rear seat 12. The airbag 32 is folded into a compact form suitable for storage (hereinafter referred to as “storage form”), and the space is stored as the storage space 33. The storage form will be described later.

  The rear impact airbag device ejects gas from the inflator 31 when an impact is applied to the vehicle 10 from the rear, causing the airbag 32 to exit obliquely rearward and downward from the storage space 33, and the rear seats 12, 12 and rear This is a device that expands and inflates between the window glass 28 and protects the occupant P seated on the rear seat 12, particularly the head Ph (see FIG. 1).

  The inflator 31 is fixed to the front end 24 b of the inner panel 24. The inflator 31 has a substantially cylindrical shape elongated in the vehicle width direction (a direction orthogonal to the paper surface in FIG. 6), and a gas generating agent (not shown) that generates gas by a combustion reaction is accommodated therein. . As the inflator 31, instead of the type using the gas generating agent, a type in which a partition wall of a high-pressure gas cylinder filled with high-pressure gas is broken with an explosive or the like to eject gas may be used.

  FIG. 8 shows the airbag 32 in a state where the airbag 32 is deployed from above to below without being filled with gas. The airbag 32 has a substantially trapezoidal outer shape in which the width W in the vehicle width direction becomes larger toward the lower side so that the airbag 32 can cover substantially the entire region of the rear window glass 28 (see FIG. 2) when deployed. ing. The airbag 32 having such an outer shape has a high strength, is flexible, and can sew one or two base fabrics 34 made of a material that can be easily folded, such as a woven fabric. Is formed into a bag shape.

  A gas supply unit 35 having a supply port 35 a is provided at the center of the upper side 32 a of the airbag 32. The gas supply unit 35 is a place to which the inflator 31 is connected.

  Attachment pieces 36 are formed at a plurality of locations on the upper side portion 32a. Each attachment piece 36 may be integrally formed with the airbag 32, or may be constituted by a separate member and retrofitted. Plates 37 made of a high-strength material, such as metal, are disposed on both the front and back surfaces of each mounting piece 36. Both plates 37 are connected to each other by a method such as caulking with the attachment piece 36 interposed therebetween.

  In the airbag 32, one lateral expansion cell 41, two side vertical expansion cells 42 and 46, and three intermediate vertical expansion cells 43 to 45 are partitioned and formed as the planned expansion portion by the above stitching. ing. These expansion cells 41 to 46 are for expanding in a cylindrical shape by the gas supplied from the inflator 31 and controlling the gas flow to control the deployment operation of the airbag 32.

  The lateral expansion cell 41 is for guiding the gas from the inflator 31 outward in the vehicle width direction, and extends in the vehicle width direction along the upper side portion 32a in the upper part of the airbag 32. The lateral expansion cell 41 communicates with the gas supply unit 35 at the center in the vehicle width direction.

  The intermediate vertical expansion cells 43 to 45 constitute a central portion in the vehicle width direction of the airbag 32 below the horizontal expansion cell 41, and are adjacent to each other in the vehicle width direction starting from the horizontal expansion cell 41. It extends downward in a combined state. The intermediate vertical expansion cells 43 to 45 communicate with the lateral expansion cell 41 at one end (upper end) of each of the intermediate vertical expansion cells 43 to 45 but do not directly communicate with the adjacent intermediate vertical expansion cells 43 to 45. Further, in the present embodiment, the gas flow passage area in the middle middle vertical expansion cell 44 is set smaller than the gas flow passage areas in the middle vertical expansion cells 43 and 45 on the left and right sides. This setting is for the gas to flow into the middle middle vertical expansion cell 44 faster than the middle middle vertical expansion cells 43 and 45 on both sides to expand and expand.

  The left and right side vertical expansion cells 42 and 46 are for guiding gas from both outer ends of the horizontal expansion cell 41 substantially downward. Both side vertical expansion cells 42, 46 are provided on both outer sides in the vehicle width direction of the airbag 32, and the interval between the side vertical expansion cells 42, 46 increases from the lateral expansion cell 41 toward the lower side. It extends diagonally outward and downward. In this way, the vertical expansion cells 42 and 46 on both sides extend in the direction intersecting the vehicle width direction. The side vertical expansion cells 42 and 46 communicate with both outer end portions of the lateral expansion cell 41 at their one end portions (upper end portions).

  In the airbag 32, a portion below the lateral expansion cell 41 and between the left side vertical expansion cell 42 and the left intermediate vertical expansion cell 43 is a non-expanded portion that is not expanded and expanded by the gas. 48 is constituted. Similarly, a portion below the lateral expansion cell 41 and between the right middle vertical expansion cell 45 and the right side vertical expansion cell 46 has a non-expanded portion 49 that is not expanded and expanded by the gas. It is composed. The positions occupied by the non-inflatable portions 48 and 49 in the airbag 32 are locations corresponding to the headrest 14 for each rear seat 12 when the airbag 32 is deployed and inflated (see FIG. 3). The non-expandable portions 48 and 49 have the following roles. One of them is to catch scattered objects from behind the vehicle 10. Further, the non-expandable portions 48 and 49 connect the side vertical expansion cell 42 and the intermediate vertical expansion cell 43 on the rear side of the left headrest 14, and the intermediate vertical expansion cell 45 and the side vertical expansion cell 46. Are connected to the rear side of the right headrest, and the longitudinal expansion cells 42, 43, 45, 46 are also positioned in the front-rear direction with respect to the headrest 14.

  Further, in the airbag 32, the non-inflatable portions 48, 49 are deployed so that the lower ends of the non-inflatable portions 48, 49 pass behind the headrests 14, 14 as the inflation cells 41-46 are deployed and inflated. A deployment assisting part is provided to assist. In the present embodiment, a deployment assist expansion cell 50 is provided on the upper portion of each non-expansion portion 48 as the deployment assist portion. Each expansion assisting expansion cell 50 expands and expands obliquely backward and downward by the gas from the inflator 31, and its lower end 50a is positioned behind the top portion 14a of the headrest 14 at the time of expansion and expansion. It assists the expansion of the inflatable portions 48 and 49 (see FIG. 13). Each expansion assisting expansion cell 50 communicates with the lateral expansion cell 41 at its upper end in a state independent of the side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 and 45.

  Further, an inner tube 51 for guiding the gas from the inflator 31 in a specific direction in the airbag 32 is provided in the airbag 32. Similar to the airbag 32, the inner tube 51 is formed by stitching one or two base fabrics 52 made of woven fabric or the like.

  The inner tube 51 includes a supply part 53 disposed in the gas supply part 35 and a guide part 54 disposed in the lateral expansion cell 41. In the supply unit 53, an end corresponding to the supply port 35a is opened, and the inflator 31 is inserted through the opening. The gas supply unit 35 and the supply unit 53 are fastened to the inflator 31 in an airtight state by an annular fastener (not shown) attached from the outside.

  The guide portion 54 extends straight in the vehicle width direction along the lateral expansion cell 41 and communicates with the supply portion 53 at a central portion in the same direction. Outlet ports 55 and 55 are opened at both outer ends of the guide portion 54 in the vehicle width direction. A lead-out hole 56 having an opening area smaller than that of the lead-out port 55 is formed below the guide portion 54 and at the center in the vehicle width direction. The outlet hole 56 is located in the vicinity of the upper part of the intermediate vertical expansion cell 44.

  By the way, FIG. 7 shows the positional relationship between the airbag 32 and the left and right rear pillar garnishes 16, 16 that are configured as described above. More specifically, in FIG. 7, the upper part shows a state in which the airbag 32 is viewed from the front direction, and the lower part shows the airbag 32 stored in the storage space 33 with the rear pillar garnishes 16 and 16 and the rear roof head. The state seen from the vehicle rear with the lining 23 is shown. And in FIG. 7, the location corresponding about an upper part and a lower part is connected by the dashed-dotted line.

  In the storage mode, the airbag 32 has a long shape extending in the vehicle width direction. Further, the airbag 32 is provided with folding portions 61 and 61 at both outer end portions in the vehicle width direction, so that the length L in the same direction is shortened.

Such a storage form is obtained by folding the airbag 32 in the deployed state as follows.
First, the airbag 32 in the deployed state shown in FIG. 9 (a) reaches the position (a position indicated by the fold line 62e) spaced a predetermined distance from the upper side 32a to the lower side 32b, and then the upper side 32a from the lower side 32b. And are folded in a spiral shape in order along the folding lines 62a to 62d. The folding direction is an upper direction that is opposite to the main deployment direction (substantially lower) of the airbag 32. As a result of this folding, the side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 to 45 are folded, and the left and right non-expanded portions 48 and 49 and the left and right expansion auxiliary expansion cells 50 and 50 are also folded. In particular, each expansion assisting expansion cell 50 is folded up and down along a predetermined fold line 62d. By such folding, a spiral portion 63 (see FIG. 6) is formed at a predetermined distance from the upper side portion 32a to the lower side portion 32b, and the lower side portion 32b of the airbag 32 approaches the upper side portion 32a.

  On the other hand, in the airbag 32, the location between the upper side portion 32a and the spiral portion 63 is along the folding lines 62e and 62f from the spiral portion 63 side toward the upper side portion 32a side or toward the opposite side. It is folded in a bellows shape, changing the folding direction alternately by a certain width. The fold line 62f is set in the middle of the lateral expansion cell 41 in the vertical direction. By this folding, a bellows fold 64 (see FIG. 6) is formed between the upper side 32 a and the spiral 63 in the airbag 32. In the bellows fold portion 64, the lateral expansion cell 41 is folded in two in the vertical direction at the fold line 62f. Accordingly, the inner tube 51 is also folded in two in the same direction. In the guide part 54, the upper part 54 a communicating with the supply part 53 and the lower part 54 b having the outlet hole 56 are folded. Further, the left and right deployment auxiliary expansion cells 50 are folded in the vicinity of their upper ends, that is, in the vicinity of the connection portion with the lateral expansion cell 41. By forming the spiral portion 63 and the bellows fold portion 64 in this way, the airbag 32 is formed into a long body 65 extending in the vehicle width direction as shown in FIG. 9B.

  At this time, the length L of the long body 65 in the vehicle width direction is the maximum length that can be taken, and is the same as the maximum value of the width W (width at the widest portion) in FIG. This length L is longer than the interval D (see FIG. 7) between the upper end portions 16a, 16a of the left and right rear pillar garnishes 16, 16. Therefore, in this state, the long body 65 cannot be stored in the storage space 33 having a width corresponding to the interval D.

  Therefore, as shown in FIG. 7, folding portions 61, 61 are provided at both outer ends of the long body 65 in the vehicle width direction, so that the length L of the long body 65 in the vehicle width direction is provided. Has been shortened. The both folded portions 61, 61 are formed by folding both outer end portions of the long body 65 in the vehicle width direction inward and outward a plurality of times (twice). It has a bellows shape of ~ 68. The layers 66 to 68 are stacked in this order from the top to the bottom.

  Each said folding part 61 is provided through the following procedure. First, as shown in FIG. 9 (b), a valley fold line 71 and a mountain fold line 72 that extend linearly in the vertical direction with respect to both outer end portions 69, 69 in the vehicle width direction of the long body 65 are respectively provided. Is set. In each outer end portion 69, the valley fold line 71 is set outside the mountain fold line 72 in the vehicle width direction. In the long body 65, the portions outside the valley fold lines 71 are valley-folded along the valley fold lines 71. Subsequently, the outer side of each mountain fold line 72 in the elongated body 65 is mountain-folded along the mountain fold line 72. The outer end portion 69 may be folded back in a different order from the above, that is, in the order of mountain fold along the mountain fold line 72 and valley fold along the valley fold line 71. By the above folding, as shown in FIG. 7, folded portions 61 and 61 are formed at both outer end portions in the vehicle width direction of the long body 65, respectively, and the airbag 32 is in a storage form.

  In this storage configuration, the length L of the airbag 32 in the vehicle width direction is slightly shorter than the distance D between the upper end portions 16a, 16a of the rear pillar garnishes 16, 16. The long body 65 at the stage before the both folded portions 61, 61 are formed is longer in the vehicle width direction than the storage space 33, but has a storage form in which the length L in the vehicle width direction is short as described above. As a result, the airbag 32 can be stored in the storage space 33. Further, the two folded portions 61, 61 are in a line-symmetric relationship with each other in the vehicle width direction.

The airbag 32 that has been compacted in the above-described storage form is bound by a binding tape (not shown) or the like at a plurality of locations including both folding portions 61 and 61.
In the airbag 32, both outer end portions in the vehicle width direction are between the upper end portions 16a and 16a of the rear pillar garnishes 16 and 16 in a state where both folded portions 61 and 61 are located below the other portions. However, it is disposed in the storage space 33 on the rear roof head lining 23 so as to be positioned in the vicinity of the inside of the upper end portions 16a, 16a.

  As shown in FIG. 6, the airbag 32 is fastened to the inner panel 24 by bolts 73 and nuts 74 in each attachment piece 36. In this state, the foremost end relating to folding of the airbag 32 is located in front of the rear end of the headrest 14.

  Further, the rear impact airbag device includes a sensor 81 and a control device 82 as shown in FIGS. 1 and 2. The sensor 81 detects an impact applied to the vehicle 10 from behind. The control device 82 controls the operation of the inflator 31 based on the detection signal from the sensor 81.

  As described above, the rear impact airbag device of this embodiment is configured. When the rear impact airbag device is not in operation, the airbag 32 is stored in the storage space 33 in the rear end of the roof 21 of the vehicle 10 and in front of and above the headrests 14 and 14 of the rear seats 12 and 12. Has been.

  When an impact of a predetermined value or more is applied to the vehicle 10 from behind, and this is detected by the sensor 81, a drive current is output from the control device 82 to the inflator 31 based on the detection signal. By heating based on this driving current, the gas generating agent in the inflator 31 reacts to generate gas.

  This gas first flows in the supply portion 53 of the inner tube 51 as indicated by an arrow in the upper half of FIG. The supply unit 53 is expanded by this gas, and the gas supply unit 35 outside the supply unit 53 is also expanded accordingly.

  The gas flows into the upper portion 54a of the guide portion 54 from the central portion in the vehicle width direction. Due to the pressure of the gas, each part of the airbag 32 (in this case, the guide part 54 and the lateral expansion cell 41) starts to be inflated and tries to eliminate the folded state. Tries to prevent the slanting of the rearward and downward expansion. Therefore, in the airbag 32 in the storage form, deployment and inflation are performed as follows.

  Since the guide portion 54 extends in the vehicle width direction, which is a direction orthogonal to the gas flow direction (downward) in the supply portion 53, the guide portion 54 flows into the upper portion 54 a from the supply portion 53. The gas changes its direction outward in the vehicle width direction, that is, in directions opposite to each other in the vehicle width direction, and is distributed substantially evenly in the same direction. Along with this, the gas pressure is transmitted outward from the center in the vehicle width direction, and the upper portion 54a and the lateral expansion cell 41 start to expand in the same direction. By this expansion, the binding tape that has bound the airbag 32 is broken. Further, a downward pressing force is applied to the rear portion (see FIG. 6) of the rear roof head lining 23 by the upper portion 54a and the lateral expansion cell 41 which are expanded by the gas as described above.

  The gas that has flowed in the guide portion 54 as described above flows outward in the vehicle width direction even after flowing into the lateral expansion cell 41 from each outlet 55, and is folded while the folding portions 61 and 61 are expanded. Try to eliminate. At the time of eliminating this, as shown in FIG. 10, in each folded portion 61, the layer 66 first expands and presses the layers 67 and 68 downward. By this pressing, the layers 67 and 68 start to be displaced while drawing an arc-shaped locus downward and outward in the vehicle width direction with the boundary portion between the layer 67 and the layer 66 as a fulcrum. Due to this displacement, each folded portion 61 starts to expand outward and downward in the vehicle width direction while being deformed (expanded), and the binding tape that has bound the folded portion 61 is broken.

  When the airbag 32 is deployed and inflated, as described above, when each folded portion 61 is displaced while drawing an arcuate locus, the layers 67 and 68 of the folded portion 61 become side edge portions 23b of the rear roof head lining 23. Press down. By this pressing, the same side edge 23b is pushed down and bent downward. When the side edge 23b gets over the upper end 16a of the corresponding rear pillar garnish 16 as shown in FIG. 10 by this depression, the same side edge 23b becomes lower than the upper end 16a, and the upper and lower sides of both the ends 23b and 16a. The positional relationship is reversed.

  Further, in each folded portion 61, the layer 67 expands due to the inflow of gas and presses the layer 68 downward. As a result of this pressing, the layer 68 is displaced while drawing an arc-shaped trajectory downward and inward in the vehicle width direction with the boundary portion with the layer 67 as a fulcrum as shown in FIG. Due to this displacement, a gap 75 is generated between the side edge 23 b and the rear pillar garnish 16. The gap 75 is expanded as the displacement of the folded portion 61 proceeds. The folded portion 61 can exit the rear roof head lining 23, that is, the storage space 33 obliquely rearward and downward by passing through the gap 75 while eliminating the folded state.

  After that, gas flows into the folded portion 61 so that the folded portion 61 develops to the lower side while expanding outward in the vehicle width direction inside the rear pillar garnish 16 while eliminating the folded state.

  By the way, when the folded state of the folded portion 61 is canceled, the both side vertical expansion cells 42 and 46 are also expanded and expanded. That is, since the layer 66, the layer 67, and the layer 68 in each folded portion 61 are configured by both outer side portions of the lateral expansion cell 41 and both side vertical expansion cells 42, 46, in each folded portion 61, When the layer 67 and the layer 68 are displaced while sequentially drawing an arc-shaped trajectory, the gas flows in the order of the lateral expansion cell 41 and the side vertical expansion cells 42 and 46. The gas is guided outward in the vehicle width direction in the lateral expansion cell 41, and is guided obliquely outward and downward in the side vertical expansion cells 42 and 46.

  In addition, since both the folding parts 61 and 61 are folded so that it may have a line symmetrical relationship with respect to a vehicle width direction, in both folding parts 61 and 61, each layer 66-68 is circular arc shape as mentioned above. Displace at approximately the same timing in opposite directions while drawing the trajectory.

  On the other hand, when the folding of the folded portions 61 to the outside in the vehicle width direction proceeds to some extent, the folded state of the lateral expansion cell 41 at the folding line 62f starts to be eliminated. The gas in the inner tube 51 flows out from the outlet holes 56 in addition to the outlets 55 and 55. When the folded state of the bellows fold portion 64 is completely eliminated by these gases, the guide portion 54 and the lateral expansion cell 41 of the inner tube 51 expand in a cylindrical shape.

  A part of the gas flowing out from the outlet hole 56 continues to flow downward as indicated by an arrow in FIG. 8 and enters the middle vertical expansion cell 44. In addition, a part of the gas flowing out from the outlet hole 56 and a part of the gas flowing out from both outlet ports 55 and 55 are located on both the left and right sides of the middle vertical expansion cell 44 by changing the flow direction downward. The intermediate vertical expansion cells 43 and 45 and the expansion auxiliary expansion cells 50 and 50 above the non-expandable portions 48 and 48 enter. Thus, due to the pressure of the gas flowing downward, the force toward the rear and lower side of the airbag 32 is increased in addition to the outward in the vehicle width direction. The gas flowing out of the inner tube 51 begins to flow into the side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 to 45 in addition to the horizontal expansion cell 41. Due to this gas, the airbag 32 starts to expand the bellows folding portion 64 and the spiral portion 63 obliquely rearward and downward in parallel with the outward deployment of the folding portions 61 in the vehicle width direction.

  As the bellows fold portion 64 and the spiral portion 63 are developed obliquely rearward and downward, the downward pressing force increases with respect to the rear portion of the rear roof head lining 23 as shown in FIG. When the increased pressing force overcomes the force of the locking piece 29a to maintain the engagement state with the rear roof head lining 23, the roof panel 22 (inner panel 24) of the rear roof head lining 23 by the locking piece 29a. ) Is released in a wide region in the vehicle width direction. Then, the rear portion of the rear roof head lining 23 tends to bend downward as indicated by a two-dot chain line in FIG. Even after the engagement state is released, the airbag 32 is inflated, so that the rear portion of the rear roof head lining 23 is displaced downward as shown in FIG. 12, and the rear roof head lining 23 and the inner panel 24 are displaced. An opening 76 wide in the vehicle width direction is formed therebetween.

  As the rear portion of the rear roof head lining 23 is pushed down, the opening 76 is enlarged. The airbag 32 divides the rear seat 12 and the rear window glass 28 along the rear window glass 28 along the rear window glass 28 as shown by a two-dot chain line while eliminating the folded state of the spiral part 63. Expand and expand downward.

  In this way, the airbag 32 is deployed while eliminating the folded state in an obliquely rearward and downward direction in addition to the outward in the vehicle width direction. The airbag 32 expands obliquely rearward and downward at the lateral expansion cells 42 and 46, the intermediate vertical expansion cells 43 to 45, and the non-inflation portions 48 and 49 while expanding outward in the vehicle width direction at the lateral expansion cell 41. .

  As shown in FIG. 8, in the airbag 32, the side vertical expansion cells 42, 46 located on the outer side in the vehicle width direction of the non-inflatable portions 48, 49 pass from the position higher than the headrest 14 to the outside of the headrest 14. Expands and expands substantially downward. More precisely, the side vertical expansion cells 42 and 46 expand and expand obliquely rearward and downward between the portion of the rear seat 12 where the headrest 14 is not provided and the rear window glass 28, and the intermediate vertical expansion cells as the lower side. It expands and expands diagonally outward and downward so as to leave the vehicle width direction outward from 43-45.

  In addition, the intermediate vertical expansion cells 43 and 45 located on the inner side in the vehicle width direction of the non-inflatable portions 48 and 49 in the airbag 32 are, together with the central intermediate vertical expansion cell 44, from the position higher than the headrest 14. 14 expands and expands downward through the inner side of 14. In other words, the three middle vertical expansion cells 43 to 45 are arranged between the left and right headrests 14 and 14 in the rear seat 12 where there is no headrest 14 in the vehicle width direction, and both in the front-rear direction. It expands and expands between the headrests 14 and 14 and between the rear window glass 28.

  In particular, in the three intermediate portion vertical expansion cells 43 to 45, the flow path area of the middle intermediate vertical expansion cell 44 is set larger than the flow passage areas of the intermediate vertical expansion cells 43 and 45 on both left and right sides. Therefore, the gas flows faster in the intermediate vertical expansion cell 44 than in the intermediate vertical expansion cells 43 and 45. Therefore, the middle vertical expansion cell 44 in the center is expanded and expanded in advance by the gas from the outlet hole 56, and the intermediate vertical expansion cell by the gas from the outlet hole 56 and the gas from both outlet ports 55 and 55. 43 and 45 expand and expand downward slightly after the intermediate vertical expansion cell 44.

  The expansion and expansion of the both side vertical expansion cells 42 and 46 obliquely outward and downward and obliquely rearward and downward and the expansion expansion and expansion of the intermediate vertical expansion cells 43 to 45 obliquely rearward and downward are performed at substantially the same timing.

  By the way, the non-expandable portions 48 and 49 that do not directly flow in gas and cannot be expanded by themselves are pulled by the both side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 and 45 that expand and expand as described above. An attempt is made to exit diagonally backward and downward from the storage space 33 and unfold between the headrests 14, 14 and the rear window glass 28. At this time, the headrests 14 and 14 are located in the vicinity of the deployment path of the non-inflatable portions 48 and 49, and may hinder the deployment of the non-inflatable portions 48 and 49.

  In this regard, in the present embodiment, the expansion assisting expansion cell 50 is provided at the upper portion of each of the non-expanding portions 48 and 49, and the expansion of the non-expanding portions 48 and 49 is assisted. More specifically, when the side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 to 45 are expanded and expanded by the gas ejected from the inflator 31, in addition to them, the gas is not expanded 48, 49. It also flows into the expansion assisting expansion cells 50, 50 at the upper part. Due to this inflow, as indicated by a two-dot chain line and a solid line in FIG. 13, the expansion assisting expansion cells 50 and 50 expand and expand obliquely rearward and downward while eliminating the folded state at the initial expansion of the non-expanded portions 48 and 49. With this expansion, the lower end 50a of the expansion auxiliary expansion cell 50, 50 is displaced rearward from the top 14a of the headrest 14 and hits the headrest 14. By these deployment auxiliary expansion cells 50, 50, the left and right portions of each deployment auxiliary expansion cell 50 are pulled in the non-expanded portions 48, 49. Then, in each of the non-expandable portions 48, 48, the portions 48 a, 49 a below the deployment auxiliary expansion cell 50 are guided to the rear side from the top portion 14 a of the headrest 14.

  Thereafter, the portions 48a and 49a are pulled obliquely rearward and downward by the both side vertical expansion cells 42 and 46 and the middle vertical expansion cells 43 and 45 that continue to expand, and the folded state is eliminated on the rear side of the headrest 14. While developing. More specifically, the side vertical expansion cells 42, 46 expand and expand substantially downward from a position higher than the headrest 14 through the outside of the headrest 14. At this time, the side vertical expansion cells 42 and 46 are expanded and expanded obliquely rearward and downward so as to move backward from the headrest 14 toward the lower side in the front-rear direction. Further, in the vehicle width direction, the side vertical expansion cells 42 and 46 expand and expand obliquely outward and downward so as to move away from the headrest 14 toward the lower side. The side vertical expansion cells 42 and 46 that expand and expand in this manner pull the non-inflatable portions 48 and 49 obliquely rearwardly downward and obliquely outwardly downward, and reliably deploy on the rear side of the headrest 14.

  Further, the middle vertical expansion cells 43 and 45 expand and expand substantially downward from a position higher than the headrest 14 through the inside of the headrest 14. At this time, the intermediate vertical expansion cells 43 and 45 expand and expand obliquely rearward and downward so as to move backward from the headrest 14 toward the lower side in the front-rear direction. The non-inflatable portions 48 and 49 are pulled obliquely outward and downward by the intermediate vertical expansion cells 43 and 45 that expand and expand in this manner, and are reliably deployed behind the headrest 14.

  When the airbag 32 expands to the lowest position that can be taken, the entire airbag 32 is deployed. In this state, the airbag 32 has a substantially trapezoidal shape substantially the same as the shape between the left and right rear pillar garnishes 16 and 16 and covers substantially the entire area of the rear window glass 28.

  When the entire airbag 32 is deployed as described above, the head Ph of the occupant P seated on the rear seat 12 and the rear window glass 28 form the airbag 32 (see the two-dot chain lines in FIGS. 1 and 12). Isolated. Therefore, not only the impact applied to the rear of the vehicle 10 is absorbed by the expanded and expanded cells 41 to 46 and the expanded non-expanded portions 48 and 49, but also scattered objects and intrusions from the rear of the vehicle. The influence on the interior of the passenger compartment 11 by an object or the like is reduced. Furthermore, the posture change of the passenger | crew P to the back is suppressed.

According to the embodiment described in detail above, the following effects can be obtained.
(1) Non-inflatable portions 48 and 49 that are not inflated by gas are provided at portions corresponding to the headrest 14 of the airbag 32. Then, at the upper part of these non-expandable portions 48 and 49, the gas from the inflator 31 expands and expands at least obliquely backward and downward, and at the time of the expansion, the lower end 50a of the headrest 14 is displaced to the rear side of the top portion 14a. A deployment auxiliary expansion cell 50 is provided.

  By assisting the expansion of the non-expandable portions 48 and 49 by the expansion assisting expansion cell 50, when the non-expandable portions 48 and 49 are expanded along with the expansion and expansion of the planned expansion portion, the non-expandable portions 48 and 49 are moved to the The non-inflatable portions 48 and 49 can be accurately deployed between the headrest 14 and the rear window glass 28.

  (2) About the inside of the airbag 32, the side part vertical expansion cells 42 and 46 which expand and expand diagonally backward and downward in the front-rear direction are provided outside the non-inflatable parts 48 and 49 in the vehicle width direction. Therefore, the non-expandable portions 48 and 49 are pulled obliquely rearward and downward from the outside in the vehicle width direction by the side vertical expansion cells 42 and 46 so that the non-expandable portions 48 and 49 are accurately deployed on the rear side of the headrest 14. be able to.

  (3) As the side vertical expansion cells 42 and 46, in the expanded and expanded state, those which are inclined outward and downward so as to be located on the outer side in the vehicle width direction are adopted as the lower side. Therefore, the non-expandable portions 48 and 49 are pulled diagonally outward and downward from the outside in the vehicle width direction by the side vertical expansion cells 42 and 46, so that the non-expandable portions 48 and 49 are more accurately located behind the headrest 14. Can be deployed.

  (4) About the inside of the airbag 32, the intermediate part vertical expansion cells 43 and 45 which expand and expand diagonally backward and downward in the front-rear direction are provided inside the non-inflatable parts 48 and 49 in the vehicle width direction. Therefore, the non-expandable portions 48 and 49 are pulled obliquely rearward and downward from the vehicle width direction inner side by the intermediate vertical expansion cells 43 and 45 so that the non-expandable portions 48 and 49 are accurately deployed on the rear side of the headrest 14. be able to.

Note that the present invention can be embodied in another embodiment described below.
-Although detailed description was abbreviate | omitted in the said embodiment, as shown to Fig.14 (a), (b), in the airbag 32, the non-expansion parts 48 and 49 and the expansion plan part (expansion cells 41-46), The front overlapping portion 85 and the rear overlapping portion 86 are partitioned by a joining portion 87 that joins each other. The joint portion 87 corresponds to a portion stitched by a sewing thread, and also corresponds to a portion bonded by an adhesive. 14 (a) and 14 (b), side vertical expansion cells 42 and 46 and intermediate vertical expansion cells 43 and 45 are shown as a part of the expected expansion portion. In FIG. 14, the upper side in the figure is the “vehicle front side” and the lower side is the “vehicle rear side”.

  Among these joint portions 87, those that define the non-expanded portions 48 and 49 (referred to as joint portions 87a in order to distinguish them from the other joint portions 87) are used as a deployment assisting portion that replaces the deployment assisting expansion cell 50. You may set to the back side rather than the intermediate part of the front-back direction about the expansion plan part which adjoins the non-expansion parts 48 and 49 and is in a deployment expansion state. Here, the expected expansion portions adjacent to the non-expandable portion 48 are the side vertical expansion cell 42 and the intermediate vertical expansion cell 43, and the expected expansion portions adjacent to the non-expandable portion 49 are the intermediate vertical expansion cell 45 and the side portion. This is a longitudinal expansion cell 46.

  In this way, the non-expandable portions 48 and 49 are pulled by the expansion-expanded portion that expands and expands, exits obliquely rearward and downward from the storage space 33, and attempts to expand between the headrest 14 and the rear window glass 28. The joining portion 87a that partitions the non-expandable portions 48 and 49 functions as a deployment assisting portion. That is, when the joint 87a is provided in the intermediate portion in the front-rear direction of the expected expansion portion (see FIG. 14C) by the above setting for the position of the joint 87a, or is set at the front side thereof. Compared to the case (not shown), the joint 87a is pulled by the expected expansion portion on the rear side. As a result, the non-expandable portions 48 and 49 are surely deployed downward on the back side of the headrest 14 without being obstructed by the headrest 14, and the same as in the above embodiment in which the deployment auxiliary expansion cell 50 is used as the deployment assisting portion. The following actions and effects can be obtained.

  In the rear impact airbag device having the deployment auxiliary inflation cell 50 (the above-described embodiment corresponds to this), the joint 87a is placed behind the intermediate portion in the front-rear direction with respect to the inflation-expanded portion in the deployed and expanded state. It may be set. In this case, a greater effect can be obtained as the effect of the above-described expansion assisting portion that causes the non-expanded portions 48 and 49 to be accurately deployed between the headrest 14 and the rear window glass 28.

  -You may change suitably the form of the folding part 61 in the elongate body 65. FIG. For example, the folded portion 61 may be provided only at one outer end 69 in the vehicle width direction of the long body 65, or in addition to one outer end 69 or both outer ends 69, 69. You may provide in a part. Further, each folded portion 61 may be formed in a spiral shape instead of the bellows shape. Furthermore, the number of foldings in each folding unit 61 may be changed to a number different from that in the above embodiment.

The left and right folded portions 61 may be folded in a manner that is not line-symmetric with respect to the vehicle width direction.
-The gas supply part 35 does not necessarily need to be correctly provided in the center part about the vehicle width direction of the airbag 32, and may be provided in the location somewhat shifted | deviated. Even in this case, the gas ejected from the inflator 31 is guided substantially equally to both outer ends of the long body 65, and both folded portions 61, 61 are substantially evenly spaced outward in the vehicle width direction. It is possible to deploy to.

-When the airbag 32 in the deployed state is folded upward from the lower end, for example, the entire airbag 32 may be folded in a bellows shape in a manner different from the above embodiment.
In order to inflate the airbag 32 between the left and right rear pillars 15 and 15 with an appropriate tension applied in the vehicle width direction and deploy the airbag 32 to an appropriate shape, the following configuration may be employed.

  Guide shafts are provided in the vicinity of the left and right rear pillars 15, 15, respectively, and straps are provided below the left and right side edges of the deployed airbag 32. Then, the guide ring attached to each strap is loosely fitted to each guide shaft. By doing so, the guide ring moves from the top to the bottom while being guided along the guide shaft when the airbag 32 is deployed and inflated.

The present invention can also be applied to a rear impact airbag device that does not have the inner tube 51 in the airbag 32.
-In the airbag 32, although the expansion cells 41-46 correspond to the planned expansion | swelling part, you may change the position of these expansion cells 41-46, a shape, etc. suitably. The mode of this change includes a mode in which at least one of the side vertical expansion cells 42 and 46 and the intermediate vertical expansion cells 43 and 45 is omitted.

  The expansion assisting expansion cell 50 may be expanded and expanded in a direction different from that in addition to the diagonally backward and downward direction.

The side view which shows the rear part of the vehicle in one Embodiment which actualized this invention. The rear view which shows the state which looked at the vehicle from back. FIG. 3 is a schematic plan sectional view showing a positional relationship between a rear seat and a deployed airbag. The perspective view which shows the positional relationship of a rear roof headlining, a rear pillar garnish, and a lower garnish when seeing diagonally back in a vehicle interior. Sectional drawing which expands and shows the cross-section along line 5-5 in FIG. The fragmentary sectional side view which shows the cross-section of the rear-end part of the roof in a vehicle. Schematic which shows the positional relationship of the airbag made into the form for storage, and both right-and-left rear pillar garnishes. The front view which shows the airbag of the expansion | deployment state. (A) is a front view which shows the positional relationship of the airbag and folding line of a deployment state, (b) is a front view which shows the positional relationship of the airbag made into the elongate body, and a folding line. Explanatory drawing which shows the stage in the middle of the folding state of a folding part about X part of FIG. Explanatory drawing which similarly shows the step in the middle of the folding state of a folding part about X part of FIG. 7 being canceled. The partial sectional side view which shows the stage in the middle of an airbag coming out diagonally back downward from a storage space, and a non-inflatable part developing on the back side of a headrest. Schematic explaining the state which a deployment auxiliary expansion cell expands and expands, and a non-expansion part expands on the back side of a headrest. (A), (b) is the schematic explaining another embodiment of an expansion | deployment auxiliary | assistant part, (c) is the schematic which shows a comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 12 ... Rear seat, 14 ... Headrest, 14a ... Top part, 21 ... Roof, 28 ... Rear window glass, 31 ... Inflator, 32 ... Air bag, 33 ... Storage space, 41 ... Lateral expansion cell (expansion planned part) , 42, 46 ... side part longitudinal expansion cell (expanded part), 43 to 45 ... intermediate part longitudinal expansion cell (expansion part), 48, 49 ... non-expandable part, 50 ... deployment auxiliary expansion cell, 50a ... lower end, 85: front overlapping portion, 86: rear overlapping portion, 87, 87a, joining portion.

Claims (6)

Folding the airbag in which a portion to be inflated is formed, the airbag is placed on the roof of the vehicle so that the foremost end for folding the airbag is in front of the rear end of the headrest of the rear seat. The airbag is stored in a storage space in a rear end portion, and the airbag is ejected obliquely backward and downward from the storage space by a gas that is ejected from an inflator in response to an impact from the rear of the vehicle and flows into the planned expansion portion. A rear impact airbag device adapted to be deployed and inflated between a rear seat and a rear window glass,
A portion corresponding to the headrest of the airbag is provided with a non-inflatable portion that is not inflated by the gas, and the non-inflatable portion is disposed behind the headrest when the non-inflatable portion is deployed along with the deployment and expansion of the planned inflation portion. A rear impact airbag device, characterized in that a deployment assisting portion is provided that guides to the side and assists the deployment. The expansion assisting portion is provided at an upper portion of the non-expanding portion and expands and expands at least obliquely rearward and downward by gas from the inflator, and the lower end of the expansion assisting portion is displaced to the rear side of the top portion of the headrest at the time of expansion The airbag apparatus for rear impacts of Claim 1 comprised by the deployment auxiliary | assistant expansion | swelling cell which performs. Inside the airbag, on the outside in the vehicle width direction of the non-inflatable portion, a part of the planned inflation portion is formed, and the gas from the inflator passes the outside of the headrest from a location higher than the headrest. 3. The rear impact airbag device according to claim 1, wherein side longitudinal expansion cells that are expanded and inflated obliquely rearward and downward are partitioned and formed adjacent to the non-inflatable portion. The airbag apparatus for a rear-end collision according to claim 3, wherein the side vertical expansion cell is inclined so as to be positioned on the outer side in the vehicle width direction toward the lower side in the deployed and inflated state. Inside the airbag, inside the non-inflatable portion in the vehicle width direction forms a part of the inflated portion, and the gas from the inflator passes the inside of the headrest from a location higher than the headrest. The airbag apparatus for rear impacts as described in any one of Claims 1-4 in which the intermediate part vertical expansion cell which expand | swells and expands diagonally back downward is formed adjacent to the said non-expansion part. The non-expandable portion and the expansion-expected portion are partitioned and formed in a joint portion that joins the front overlap portion and the back overlap portion to each other, and the joint portion that forms the non-expand portion is the unfolded portion. The airbag apparatus for rear impacts of Claim 1 set as the auxiliary | assistant part to the back side rather than the intermediate part in the front-back direction about the said expansion plan part of the expansion | deployment state.

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