JP2005096654A - Air bag for rear seat, and air bag device for rear seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air bag for a rear seat and an air bag device for the rear seat capable of protecting the knees of a rear seat occupant and having higher protection performance of the head of the rear seat occupant. <P>SOLUTION: The air bag 16 deploys and inflates from the downside of the seat 12 of a front seat 11. The air bag 16 comprises a front side inflation part 19 deploying and inflating upward along the back surface of the backrest section 18 and a rear side inflation part 20 opening and inflating backward from the tip side of the front side inflation part 19. The inside of the air bag 16 is provided with a second tether 28b which partitions the inside to the front side inflation part 19 and the rear side inflation part 20 and adjusts the gas transfer amount from the front side inflation part 19 to the rear side inflation part 20. The second tether 28b reduces gas flow rate with deployment and inflation of the air bag 16, and adjusts the inner pressure of the rear side inflation part 20 to be lower than the inner pressure of the front side inflation part 19. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to a rear seat airbag that deploys and inflates between a front seat and a rear seat when an impact due to a collision or the like is applied to the vehicle, and a rear seat airbag including the rear seat airbag. It relates to the device. In this specification, “front seat” means a seat with other seats behind, and is not limited to a driver seat and a passenger seat. The “rear seat” means a seat behind the “front seat”.

Conventionally, as a rear seat airbag device of this type, an airbag module is deployed and inflated in front of a chest and a head of a rear seat occupant from an airbag module provided at a rear portion of a seat portion of a front seat. There is something. The airbag is deployed and inflated upward along the back of the backrest portion of the front seat in the first stage, and deployed and inflated in front of the chest and head of the rear seat occupant in the second stage.
Japanese translation of PCT publication No. 2002-542100 (page 10, FIG. 1)

  By the way, for example, a rear-seat airbag is strongly resistant to a rear-seat occupant who moves forward due to a frontal collision with another vehicle, while preventing the rear-seat occupant from moving forward with the entire body. It is desirable to softly catch the low tolerance head.

  However, in the technique of Patent Document 1, since the entire airbag has the same internal pressure, if the height of the internal pressure is set to such a value that the airbag can strongly receive the knee, the airbag softens the head. I can't take it. Therefore, it has been difficult to achieve sufficient protection performance for the knee and head of the rear seat occupant.

  An object of the present invention is to provide a rear-seat airbag and a rear-seat airbag device that can protect the knees of the rear-seat occupant and have higher protection performance against the head of the rear-seat occupant. .

  In order to solve the above-mentioned problem, the invention according to claim 1 is a rear seat airbag that expands and inflates from the lower part of the front seat to the back side of the backrest part of the front seat, and extends along the back surface of the backrest part. Thus, the front side expansion part that expands and expands upward, the rear side expansion part that expands and expands backward from the front end side of the front side expansion part, and the internal pressure that makes the internal pressure of the rear side expansion part lower than the internal pressure of the front side expansion part And adjusting means.

  Therefore, according to the first aspect of the present invention, when the airbag is deployed and inflated, the front inflatable portion is deployed and inflated from the lower part of the front seat to above the knee of the rear seat occupant, and then from the front end side of the front inflatable portion. The rear expansion portion expands and expands rearward. At this time, the internal pressure of the rear expansion part is adjusted to be lower than the internal pressure of the front expansion part by the internal pressure adjusting means. For this reason, for example, when the rear seat occupant moves forward from the rear seat due to a collision with another vehicle, the knee of the rear seat occupant is strongly received by the front side inflatable portion with high internal pressure, and the chest of the rear seat occupant The head is weakly received by the rear expansion portion having a low internal pressure.

  According to a second aspect of the present invention, in the first aspect of the invention, the front side inflating portion and the rear side inflating portion define the interior of one airbag and gas from the front side inflating portion to the rear side inflating portion. The partition means is configured to reduce the flow rate of the gas that is moved from the front inflating portion to the rear inflating portion as the airbag is deployed and inflated.

Therefore, according to the second aspect of the present invention, the front-side inflatable portion and the rear-side inflatable portion are partitioned and formed inside the airbag by the partition means as one airbag is deployed and inflated.
According to a third aspect of the present invention, in the second aspect of the present invention, the internal pressure adjusting means is a gas discharge means provided in the rear side expansion portion, and the gas discharge means is connected to the front expansion portion. By discharging a part of the gas that has moved to the rear inflating part to the outside of the airbag, the internal pressure of the rear inflating part is made lower than the internal pressure of the front inflating part.

  Therefore, according to the third aspect of the present invention, a part of the gas moved from the front side expansion part to the rear side expansion part is released to the outside by the internal pressure adjusting means, so that the internal pressure of the rear side expansion part is increased to the front side. The pressure is adjusted to be lower than the internal pressure of the expansion portion.

  According to a fourth aspect of the present invention, in the second aspect of the invention, the internal pressure adjusting means is the partition means, and the partition means is configured to expand the front-side inflating portion as the airbag is deployed and inflated. The internal pressure of the rear side expansion part is made lower than the internal pressure of the front side expansion part by reducing the flow rate of the gas moved from the first to the rear side expansion part.

  Therefore, according to the fourth aspect of the present invention, the partition means for partitioning the interior of the airbag into the front inflating portion and the rear inflating portion is changed from the front inflating portion to the rear inflating portion as the airbag is deployed and inflated. By reducing the flow rate of the gas to be moved, the internal pressure of the rear side expansion part is adjusted to be lower than the internal pressure of the front side expansion part.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the partitioning unit connects the upper side portion and the lower side portion of the airbag and provides gas flow paths between the left and right side portions, respectively. It is a tether to be formed.

  Therefore, according to the invention described in claim 5, in addition to the action of the invention described in claim 4, the tether that connects the upper side portion and the lower side portion of the airbag and adjusts the deployed and expanded shape of the airbag. As a result, the front inflating portion and the rear inflating portion are formed inside the airbag, and the internal pressure of the rear inflating portion is adjusted to be lower than the internal pressure of the front inflating portion.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the rear side inflating portion is disposed at a lower position on the rear seat occupant side. A restraining means for restraining the portion to the front expansion portion is provided.

  Therefore, according to the sixth aspect of the present invention, when the airbag is deployed and inflated, the front inflatable portion is deployed and inflated from the lower portion of the front seat to above the knee of the rear seat occupant, and then from the front end side of the front inflatable portion. The rear expansion portion expands and expands rearward. At this time, the restraint means restricts the deployed and expanded position of the rear inflatable part, and the constraining means is disposed at a position that covers the upper part of the thigh of the rear seat occupant. For this reason, a rear side expansion | swelling part can be expand | deployed and expanded between a chest part and a backrest part of a backseat passenger | crew. Therefore, when a sudden forward acceleration is applied to the rear seat occupant due to a rear-end collision with another vehicle, the rear inflating portion in which the chest of the rear seat occupant moving forward from the rear seat abuts the back of the backrest portion Is effectively received. Further, when the upper body tilts forward, the head that moves forward and downward is effectively received by the rear inflating portion that abuts both legs or the backrest.

  According to a seventh aspect of the present invention, a case in which an airbag and an inflator are accommodated is disposed on the seat portion of the front seat or on the lower side of the seat portion, and the inflator is operated based on an impact applied to the vehicle. A rear seat airbag device for deploying and inflating a bag, wherein the rear seat airbag according to any one of claims 1 to 6 is used as the airbag.

  It is possible to provide a rear seat airbag and a rear seat airbag device that can protect the knees of the rear seat occupant and that have higher protection performance against the head of the rear seat occupant.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, an airbag module 10 as an airbag device for a rear seat of the present embodiment is fixed to the lower surface of a seat portion 12 of a front seat 11 provided in a vehicle and is seated on a rear seat 13. The seat occupant 14 is protected. As shown in FIG. 2, the airbag module 10 is configured by housing a folded airbag 16 and an inflator 17 that supplies gas to the airbag 16 in a case 15 fixed to the seat portion 12. Has been.

  The airbag 16 includes a front inflating portion 19 that expands and expands upward along the back surface of the backrest portion 18 of the front seat 11 between the front seat 11 and the rear seat 13, and a front end side of the front inflating portion 19. To the rear seat 13 side and a rear inflating portion 20 that expands and inflates. The front inflating portion 19 expands and inflates upward from below the seat portion 12 along the back surface of the backrest portion 18 of the front seat 11 and corresponds to a range from the lower portion of the knee 21 of the rear seat occupant 14 to the height of the chest portion 22. It is arranged at the position to do. The rear inflating portion 20 is deployed and inflated rearward from the front end portion of the front inflating portion 19, and is disposed in a range corresponding to the chest portion 22 from the knee 21 of the rear seat occupant 14 to the upper portion of the thigh 32. The airbag 16 is formed by stitching a front base fabric 23 and a rear base fabric 24 together. Gas is supplied to the airbag 16 from the inflator 17.

  As shown in FIG. 2, the front base fabric 23 and the rear base fabric 24 are connected to each other by sewing within the airbag 16 by a first tether 28a, a second tether 28b, and a third tether 28c. The first tether 28a is provided on the base end side of the front expansion portion 19, the second tether 28b is provided at the boundary between the front expansion portion 19 and the rear expansion portion 20, and the third tether 28c is rear expansion. The unit 20 is provided at a substantially central position. Accordingly, the thickness of the airbag 16 is defined by the first tether 28a to the third tether 28c. In the present embodiment, the second tether 28b is an internal pressure adjusting means and a partitioning means.

  As shown in FIG. 3, the second tether 28 b is provided at the center in the width direction of the airbag 16, and defines the front inflating portion 19 and the rear inflating portion 20 by partitioning the inside of the airbag 16. Yes. Further, the second tether 28b adjusts the amount of gas movement from the front inflating portion 19 to the rear inflating portion 20 through the gas flow paths 33 formed on both sides of the airbag 16 during the inflating and inflating process. That is, the second tether 28b is folded between the front base fabric 23 and the rear base fabric 24 before the airbag 16 is deployed and inflated. As shown in FIGS. 4A and 4B, the second tether 28b gradually reduces the cross-sectional area of the gas flow path 33 on both sides of the airbag 16 in the process of inflating and inflating the airbag 16. That is, before and during deployment of the airbag 16, the airbag 16 is in a flat and wide state, and the cross-sectional area of the gas flow path 33 between the second tether 28b and both side ends of the airbag 16 is large. However, the width of the airbag 16 is narrowed immediately before and after the deployment of the airbag 16 and the sectional area of the gas flow path 33 is reduced. Thus, the second tether 28b restricts the movement of gas from the front inflating portion 19 to the rear inflating portion 20 at the end of the deployment of the airbag 16, and the internal pressure of the rear inflating portion 20 is greater than the internal pressure of the front inflating portion 19. To be low.

  On the other hand, the first tether 28a and the third tether 28c are formed to have a width smaller than that of the second tether 28b, and unlike the second tether 28b, the movement of gas between the front and rear thereof even when the airbag 16 is deployed and inflated. Not to restrict.

  As shown in FIG. 1, a vent hole 34 is provided on one side wall of the rear side expansion portion 20. The vent hole 34 discharges a part of the gas from the inside of the rear inflating portion 20 of the deployed airbag 16 to the outside, so that the internal pressure of the rear inflating portion 20 is lower than the internal pressure of the front inflating portion 19. It is supposed to be. In the present embodiment, the vent hole 34 is an internal pressure adjusting means and a gas releasing means.

  As shown in FIGS. 1 to 4, the airbag 16 is provided with two pairs of left and right reinforcing cloths 29 </ b> R and 29 </ b> L that connect the front inflating portion 19 and the rear inflating portion 20 outside. The reinforcing cloths 29R and 29L are substantially right-angled triangles, and are sewn together at the seams of the front base cloth 23 and the rear base cloth 24. At this time, the reinforcing cloths 29R and 29L are sewn so that the right-angle portions thereof are on the boundary side between the front expansion portion 19 and the rear expansion portion 20, respectively. Then, both the reinforcing cloths 29R and 29L are arranged so that when the airbag 16 is deployed and inflated, the front inflating portion 19 is deployed and inflated upward from below the seat portion 12 of the front seat 11, and then from the front end side of the front inflating portion 19. The rear inflatable part 20 is constrained to the front inflatable part 19 so as to cover the upper part of the thigh 32 of the rear seat occupant 14.

Next, the operation of the present embodiment configured as described above will be described.
For example, when the inflator 17 is ignited by an impact caused by a collision and gas is supplied from the inflator 17 to the airbag 16, the airbag 16 jumps out of the case 15 and expands and expands to the back side of the backrest portion 18 of the front seat 11. At this time, in the airbag 16, first, the front inflating portion 19 is deployed and inflated upward from below the seat portion 12 of the front seat 11, and is disposed between the backrest portion 18 and the knee 21 of the rear seat occupant 14. .

  Following the expansion of the front expansion part 19, the rear expansion part 20 expands and expands from the front end side of the front expansion part 19. At this time, the left and right side surfaces of the rear inflatable portion 20 are restrained by the left and right side surfaces of the front inflatable portion 19 by a pair of left and right reinforcing cloths 29R and 29L, and extend along the upper portion of the thigh 32 of the rear seat occupant 14. It expands and expands in a bent state.

  When the airbag 16 is deployed and inflated, the opening area of the gas flow path 33 decreases with the deployment and inflation of the airbag 16 and the extension of the second tether 28b, and the front inflatable portion 19 changes to the rear inflatable portion 20. The flow rate of the moving gas is limited. Further, part of the gas that has moved from the front inflating portion 19 to the rear inflating portion 20 is released to the outside of the airbag 16 through the vent hole 34. For this reason, when the airbag 16 is deployed and inflated, the internal pressure of the rear inflatable portion 20 becomes lower than the internal pressure of the front inflatable portion 19.

  When the rear seat occupant 14 moves forward from the rear seat 13 due to inertia while the airbag 16 is inflated and inflated, first, as shown in FIG. 5, the knee 21 has a rear surface with respect to the front inflatable portion 19 having a high internal pressure. The impact applied to the knee 21 is absorbed and the forward movement of the rear seat occupant 14 is restricted. Subsequently, the chest 22 of the rear seat occupant 14 hits the rear inflatable portion 20 having a low internal pressure from the rear surface, and the impact applied to the chest 22 is softly absorbed. Furthermore, as shown in FIG. 6, when the upper body of the rear seat occupant 14 falls forward, the head 31 hits the rear inflatable portion 20 from the upper surface, and the impact applied to the head 31 is softly absorbed. Further, as the chest 22 and the head 31 are pressed against the rear inflating portion 20, gas is released from the inside of the rear inflating portion 20 to the outside through the vent hole 34, and an increase in the internal pressure is suppressed. For this reason, the impact applied to the chest 22 and the head 31 is further alleviated.

Therefore, according to this embodiment, the following effects can be obtained.
(1) The airbag 16 that expands and inflates from the lower part of the front seat 11 to the back side of the backrest part 18 is expanded and inflated upward along the back surface of the backrest part 18 by the second tether 28b; The front side expansion part 19 was partitioned into a rear side expansion part 20 that expands and expands backward from the front end side. The second tether 28b reduces the flow rate of the gas moving from the front inflating portion 19 to the rear inflating portion 20 as the airbag 16 is deployed and inflated, and the internal pressure of the rear inflating portion 20 is reduced to the internal pressure of the front inflating portion 19. Adjust lower than. For this reason, for example, when the rear seat occupant 14 moves forward from the rear seat 13 due to a collision with another vehicle, the knee 21 of the rear seat occupant 14 is strongly received by the front inflating portion 19 with high internal pressure, and the rear The chest 22 and the head 31 of the seat occupant 14 are weakly received by the rear inflating portion 20 having a low internal pressure. Accordingly, the knee 21 of the rear seat occupant 14 can be protected, and the protection performance of the rear seat occupant 14 on the chest 22 and the head 31 is further improved.

  (2) The vent hole 34 provided in the rear inflating portion 20 releases part of the gas from the inside of the rear inflating portion 20 to the outside, and the internal pressure at the end of the deployment of the airbag 16 is set to the internal pressure of the front inflating portion 19. Lower than. Further, when the rear seat occupant 14 moves forward from the rear seat 13 and is received by the rear inflating portion 20 due to inertia at the time of the collision, gas is released to the outside from the vent hole 34 and the increase in the internal pressure is suppressed. Is done. Therefore, the protection performance for the chest 22 and the head 31 of the rear seat occupant 14 is further improved.

  (3) A pair of left and right reinforcements that restrain the rear inflatable portion 20 to the front inflatable portion 19 outside the airbag 16 so as to cover the upper portion of the thigh 32 of the rear seat occupant 14. Cloth 29R and 29L were provided. For this reason, when the rear seat occupant 14 moves forward from the rear seat 13 due to a rapid forward acceleration, the rear inflatable portion 20 that expands and expands between the chest 22 and the backrest portion 18 of the rear seat occupant 14, The rear seat occupant 14 is effectively received.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, about the same structure as 1st Embodiment, the code | symbol is made the same, the description is abbreviate | omitted, and only the airbag 40 different from 1st Embodiment is explained in full detail.

  As shown in FIG. 7, the airbag 40 of the present embodiment is configured by joining two independent front airbags 41 and a rear airbag 42. The front airbag 41 as the front inflating portion corresponds to the front inflating portion 19 in the first embodiment, and is deployed and inflated upward from the lower portion of the seat portion 12 of the front seat 11 along the back surface of the backrest portion 18. The seat occupant 14 is disposed at a position corresponding to the range from the lower side of the knee 21 to the height of the chest 22. Further, the rear airbag 42 as the rear inflating portion corresponds to the rear inflating portion 20 and is deployed and inflated rearward from the front end portion of the front inflating portion 19, and from the knee 21 of the rear seat occupant 14 to the thigh. In the upper part of 32, it is arranged in a range substantially corresponding to the chest 22. The rear surface of the front airbag 41 and the front surface of the rear airbag 42 are integrated by being sewn at their peripheral edges.

  Both the airbags 41 and 42 are communicated with each other through a communication hole 43 provided on the joint surface. The gas supplied from the inflator 17 to the front airbag 41 is supplied to the rear airbag 42 through the communication hole 43. Inside the rear surface of the rear airbag 42, a slide cloth 44 is provided as an internal pressure adjusting means for opening and closing the communication hole 43 as the airbag 40 is deployed and inflated.

  The slide cloth 44 has an upper end side sewn on the upper side portion of the rear airbag 42 and a lower end side sewn on the lower side portion. The slide cloth 44 is provided with a hole 45 having the same diameter as the communication hole 43. As shown in FIGS. 7 and 9A and 9B, the slide cloth 44 is in a state where the airbag 40 is also deployed when the airbag 40 is deployed and inflated, and the hole 45 does not overlap the communication hole 43 in this state. It is like that. Further, as shown in FIGS. 8A and 8B, the slide cloth 44 has a communication hole 43 between the state in which both the airbags 41 and 42 are folded in the case 15 and until they are expanded and inflated to some extent. It is folded up and down so that the hole 45 is overlaid on.

  Both airbags 41 and 42 are formed by stitching two base fabrics in the same manner as in the first embodiment. In the front airbag 41, both base fabrics are stitched together with a fine pitch seam so as not to leak gas from the inside through the seams of both base fabrics. On the other hand, in the rear airbag 42, both base fabrics are stitched together with a coarse pitch seam so that gas is released from the inside through the seams of both base fabrics. Thereby, when the airbag 40 is deployed and inflated, the internal pressure of the rear airbag 42 becomes lower than the internal pressure of the front airbag 41.

  Further, the airbag 40 has a pair of left and right reinforcing fabrics 29R and 29L that connect the front airbag 41 and the rear airbag 42 outside the same as in the airbag 16 of the first embodiment (in FIG. 7). , 29L is shown).

Next, the operation of the present embodiment configured as described above will be described.
When gas is supplied from the inflator 17 to the front airbag 41, the front airbag 41 is deployed and inflated upward along the back surface of the backrest portion 18 of the front seat 11. At this time, the slide cloth 44 is folded in the vertical direction, and the hole 45 overlaps the communication hole 43 as shown in FIGS. Gas is also supplied to the rear airbag 42 through the communication hole 43, and the rear airbag 42 is also deployed and inflated.

  As the airbags 41 and 42 are deployed and inflated, the slide cloth 44 extends in the vertical direction, and the hole 45 is displaced from the communication hole 43. For this reason, the flow rate of the gas supplied from the front airbag 41 to the rear airbag 42 gradually decreases. When both airbags 41 and 42 are substantially deployed and inflated, as shown in FIGS. 9A and 9B, the slide cloth 44 is extended, and the hole 45 is not completely overlapped with the communication hole 43. In addition, a part of the gas is released from the inside of the rear side inflating portion 20 to the outside through a rough seam. For this reason, when the airbag 40 is deployed and inflated, the internal pressure of the rear airbag 42 becomes lower than the internal pressure of the front airbag 41. Therefore, the airbag 40 of this embodiment also has the same effect as the airbag 16 of the first embodiment.

Therefore, also by this embodiment, each effect described in (1)-(3) of the said 1st Embodiment can be acquired.
This embodiment can also be embodied as follows.

  In the above embodiment, instead of the reinforcing cloths 29R and 29L, a pair of left and right strings or bands that sew both ends to the rear inflatable portion 20 and the front inflatable portion 19 to restrain the rear inflatable portion 20 are provided. To do.

Hereinafter, the technical ideas grasped from the respective embodiments will be listed together with their effects.
(1) In the invention according to the rear seat airbag according to claim 1, the front inflatable portion and the rear inflatable portion are formed by independent airbags (front airbag 40, rear airbag 41), respectively. In addition, the internal pressure adjusting means (slide cross 44) is communicated from the front inflating portion through the communication hole as the two airbags are deployed and inflated. A rear seat airbag characterized in that the internal pressure of the rear inflatable portion is made lower than the internal pressure of the front inflatable portion by reducing the flow rate of the gas moving to the rear inflatable portion.

The side view which shows the airbag apparatus for rear seats of this embodiment. The longitudinal cross-sectional view which shows the airbag apparatus for rear seats. AA sectional view taken on the line in FIG. (A) is sectional drawing which shows the 2nd tether in the expansion | deployment expansion process, (b) is the BB sectional drawing of (a). The side view which shows the airbag for backseats at the time of an action | operation. The side view which shows the airbag for backseats at the time of an action | operation. The perspective view which shows the airbag for backseats of 2nd Embodiment. (A) is sectional drawing which shows the front-end | tip part of the front side expansion part in which the communicating hole and the slide cross were provided, (b) is CC sectional view taken on the line of (a). (A) is sectional drawing which shows the front-end | tip part of the front side expansion | swelling part provided with the communicating hole and the slide cross, (b) is DD sectional view taken on the line of (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Airbag module as a backseat airbag, 11 ... Front seat, 12 ... (Front seat) seat part, 14 ... Rear seat passenger, 15 ... Case, 16 ... Air bag, 17 ... Inflator, 18 ... ( Back portion of the front seat, 19 ... front inflating portion, 20 ... rear inflating portion, 28b ... second tether as internal pressure adjusting means and partitioning means, 29R, 29L ... reinforcing cloth as restraining means, 32 ... thigh 33 ... Gas flow path, 34 ... Vent hole as internal pressure adjusting means and gas releasing means, 40 ... Air bag, 41 ... Front airbag as front inflation part, 42 ... Rear airbag as rear inflation part, 43 ... Communication hole, 44 ... Slide cross as internal pressure adjusting means.

Claims (7)

A rear seat airbag that expands and inflates from the lower portion of the front seat to the back side of the backrest portion of the front seat,
A front expansion portion that expands and expands upward along the back surface of the backrest portion;
A rear side inflating part that expands and inflates backward from the front end side of the front side inflating part;
An air bag for a rear seat, comprising: an internal pressure adjusting means for making an internal pressure of the rear side inflating portion lower than an internal pressure of the front side inflating portion. The front side inflating part and the rear side inflating part are formed by a partition means that partitions the inside of one airbag and allows gas movement from the front side inflating part to the rear side inflating part,
2. The rear seat airbag according to claim 1, wherein the partition means reduces a flow rate of a gas that is moved from the front-side inflating portion to the rear-side inflating portion as the airbag is deployed and inflated. The internal pressure adjusting means is a gas releasing means provided in the rear expansion part,
The gas releasing means releases a part of the gas moved from the front side inflating part to the rear side inflating part to the outside of the airbag, so that the internal pressure of the rear side inflating part is made lower than the internal pressure of the front side inflating part. The rear seat airbag according to claim 2, wherein the airbag is a rear seat airbag. The internal pressure adjusting means is the partitioning means,
The partition means reduces the internal pressure of the rear inflatable portion lower than the internal pressure of the front inflatable portion by reducing the flow rate of the gas moved from the front inflatable portion to the rear inflatable portion as the airbag is deployed and inflated. The rear seat airbag according to claim 2.   5. The rear seat according to claim 4, wherein the partitioning means is a tether that connects the upper side portion and the lower side portion of the airbag and forms gas flow paths between the left and right side portions, respectively. Airbags.   The restraint means which restrains this rear expansion part to the front expansion part is provided so that the rear expansion part may cover the upper part of the thigh of a rear seat occupant. Item 6. The rear seat airbag according to any one of Items 5. A rear seat air in which a case containing an airbag and an inflator is disposed on the seat portion of the front seat or below the seat portion, operates the inflator based on an impact applied to the vehicle, and deploys and inflates the airbag. A bag device,
A backseat airbag device using the backseat airbag according to any one of claims 1 to 6 as the airbag.

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