JP2001114059A - Head protecting air bag device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an air bag 11 to be easily bent at a non-expansive part between a main expansion chamber Ra extending rectilinearly in the longitudinal direction of a vehicle and auxiliary expansion chambers Rb, Rc. SOLUTION: In a head protecting air bag device 10 in which an air bag 11 which is expanded--unfolded in the shape of a curtain on the sides in a car- room by gas supplied from an inflator 12, is provided with a main expansion chamber Ra extending nearly rectilinearly in the longitudinal direction of a vehicle, and auxiliary expansion chambers Rb, Rc, and connecting paths Pb, Pc1, Pc2 for connecting the auxiliary expansion chambers Rb, Rc to the main expansion chamber Ra in the vertical direction, and in which a head Hf of an occupant is protected from the sides by the main expansion chamber Ra and the auxiliary expansion chambers Rb, Rc of the air bag 11, a constricted part is formed at a position which corresponds to a non-expansive part between the main expansion chamber Ra and the auxiliary expansion chambers Rb, Rc in the connecting paths Pb, Pc1, Pc2 of the air bag 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head protection airbag device mounted on a vehicle.

[0002]

2. Description of the Related Art A head protection airbag device of this type is disclosed in, for example, International Publication WO96 / 26087, and is inflated and deployed in a curtain shape at a side portion in a vehicle cabin by supplying gas from an inflator. The occupant's head is protected from the side by an inflation chamber provided in the airbag.

[0003]

In the airbag disclosed in WO 96/26087, a plurality of inflation chambers extending in the vertical direction are provided in front and rear in parallel, and each of these inflation chambers is provided. A gas inflow portion communicating with the upper end of the gas inflow portion is provided along the upper edge, and inflation gas is supplied from an inflator to a rear end of the gas inflow portion. In the airbag having such a configuration, since the inflation gas flows downward into each inflation chamber via the gas inflow portion, it takes time to inflate each inflation chamber to some extent,
There was room for improvement in quickly securing a wide area where passengers could be restrained before the airbag inflation and deployment was completed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an airbag is inflated and deployed in a curtain shape at a side portion in a vehicle cabin by supplying gas from an inflator. A main expansion chamber connected at one end to the inflator and extending substantially linearly in the front-rear direction of the vehicle, and provided in parallel with the main expansion chamber so as to be substantially linear in the front-rear direction of the vehicle. An extending sub-inflation chamber, and a communication passage for vertically communicating the sub-inflation chamber with the main inflation chamber, wherein a head of an occupant is located in the main inflation chamber and the sub-inflation chamber of the airbag. A head protection airbag device that is protected from the side, wherein a constricted portion is formed at a position corresponding to a non-inflated portion between the main inflation chamber and the sub-inflation chamber in the communication path of the airbag. (The invention according to claim 1) There is a feature.

[0005] An airbag which is inflated and deployed in a curtain shape on the side in the vehicle cabin when gas is supplied from the inflator is connected to the inflator at one end and is substantially linear in the longitudinal direction of the vehicle. A main expansion chamber that extends, upper and lower sub-expansion chambers that are provided in parallel above and below the main expansion chamber and extend substantially linearly in the front-rear direction of the vehicle, and vertically move these two sub-expansion chambers and the main expansion chamber. A head protection airbag device having a communication passage for communicating in the same direction, wherein a head of a front occupant is protected from the side in the main inflation chamber and the sub inflation chamber of the airbag. A communication passage that communicates the main expansion chamber and the upper sub-expansion chamber is offset in front of the vehicle, and a communication passage that communicates the main expansion chamber and the lower sub-expansion chamber is offset in the rear of the vehicle. Is being done (according to claim 2 It is characterized by bright).

Further, each of the above-mentioned inventions (Claim 1 or 2)
In the invention according to the invention, a tension belt for connecting a lower portion of the airbag to the vehicle body when the airbag is inflated and deployed has one end fixed to a non-inflation portion above the main inflation chamber of the airbag, and a middle portion to the air. A portion where the main inflation chamber is formed in the airbag at an intermediate portion between the one end fixing portion and the intermediate insertion portion, the portion being movably inserted into a through hole provided in a non-inflation portion below the main inflation chamber of the bag. (The invention according to claim 3).

[0007]

In the head protection airbag device according to the present invention, the airbag is normally folded and housed, and gas is supplied from the inflator into the airbag during a side collision of the vehicle. Then, the airbag is inflated and deployed in a curtain shape at a side portion in the vehicle cabin. At this time, in the airbag, the main inflation chamber and the sub inflation chamber which extend substantially linearly in the front-rear direction of the vehicle are inflated into a cylindrical shape by the gas supplied from the inflator, and the vertical communication path is inflated into a cylindrical shape. I do.

The present invention (the invention according to claim 1)
Since the main inflation chamber of the airbag is connected at one end to the inflator and extends substantially linearly in the front-rear direction of the vehicle, the gas can quickly flow into the main inflation chamber in the initial stage of the deployment of the airbag. Can be. Further, the auxiliary inflation chamber of the airbag is provided in parallel with the main inflation chamber, extends substantially linearly in the front-rear direction of the vehicle, and communicates with the main inflation chamber through a communication passage. A portion of the gas that has flowed into the sub-expansion chamber can be quickly made to flow through the communication passage. Therefore, the inflatable portion composed of the main inflation chamber and the sub-inflation chamber can be quickly inflated from the initial stage of deployment of the airbag, and an area capable of restraining the occupant before the inflation and deployment of the airbag is completed can be quickly and widely secured.

Further, in the present invention (the invention according to claim 1), since the constricted portion is formed at a position corresponding to the non-inflated portion between the main inflation chamber and the sub-inflation chamber in the communication passage of the airbag, In this constricted portion, the airbag is easily bent in the left-right direction of the vehicle. Therefore, even when the obstacle is in the deployment direction of the airbag during the inflation and deployment of the airbag, the airbag is easily bent and deformed in the left and right directions of the vehicle at the constricted portion, and the airbag is moved from the airbag to the interference object. The acting force can be reduced, preventing large forces from acting on the interference from the airbag without strictly controlling the deployment direction of the airbag or controlling the internal pressure of the airbag. can do.

In the present invention (the invention according to claim 2), a communication passage for communicating the main expansion chamber with the upper sub-expansion chamber is offsetly disposed in front of the vehicle, and the main expansion chamber and the lower sub-expansion chamber are connected to each other. Since the communication passage that communicates with the vehicle is offset behind the vehicle, it is easy to bend in the left and right direction of the vehicle at a portion where the communication passage is not arranged between the main expansion chamber and the upper auxiliary expansion chamber, that is, at the rear portion of the vehicle. In addition, between the main expansion chamber and the lower sub-expansion chamber, it is easy to bend in the left-right direction of the vehicle at a portion where the communication passage is not arranged, that is, at the front portion of the vehicle.

[0011] Therefore, when the interfering object is in the front part of the vehicle and the airbag interferes with the interfering substance during the inflation and deployment of the airbag, the airbag is moved in the front part of the vehicle between the main inflation chamber and the lower auxiliary inflation chamber. The vehicle is easily bent and deformed in the left-right direction of the vehicle, so that a large force does not act on the interference from the airbag. Also, if the interfering object is at the rear part of the vehicle and the airbag interferes with the interfering substance, the airbag is easily bent and deformed in the left and right direction of the vehicle at the rear part of the vehicle between the main inflation chamber and the upper sub-inflation chamber. However, a large force does not act on the interference from the airbag.

Further, each of the above-mentioned inventions (Claim 1 or 2)
When the airbag is inflated and deployed, a tension belt for connecting the lower portion to the vehicle body when the airbag is inflated and deployed has one end fixed to a non-inflation portion above the main inflation chamber of the airbag, and an intermediate portion to the airbag. A structure that is movably inserted into a through hole provided in a non-inflation portion below the main inflation chamber, and overlaps with a formation portion of the main inflation chamber in the airbag at an intermediate portion between the one end fixing portion and the intermediate insertion portion. In the case of adoption (in the case of the invention according to claim 3), each of the above-described actions and
The effect can be obtained, and a large tension can be generated in the tension belt by the expansion deformation of the main expansion chamber.

Therefore, when the airbag is inflated and deployed, the tension belt can be accurately released (pulled out) from the storage portion, and after the airbag is inflated and deployed, a sufficient tension is applied to the lower portion of the airbag by the tension belt. Can be generated, and the movement of the airbag to the outside of the vehicle when the occupant is restrained can be accurately suppressed.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. In this first embodiment, a head-protecting airbag device 10 is inflated and deployed in a curtain shape at a side portion in a vehicle cabin and a front seat occupant is in a position. The airbag 11 includes an airbag 11 that protects the head Hf and the head Hr of a rear passenger, an inflator 12 that supplies gas to the airbag 11, a tension belt 13 that tensions the airbag 11, and the like.

The airbag 11 has a front-seat inflatable portion 11b and a rear-seat inflatable portion 11c in front of and behind the central non-inflating portion 11a.
, A gas introducing portion 11d at the rear upper portion, a front non-inflatable portion 11e at the lower front portion, and a plurality of mounting pieces 11f at the upper edge portion. The airbag 11 includes a front pillar 21 of the vehicle body and a roof side rail 2 using bolts and nuts (both not shown) at each mounting piece 11f.
2 is installed.

The airbag 11 is accommodated in a folded state along the front pillar 21, the roof side rail 22 and the quarter pillar 23, and has a front pillar garnish 31 whose lower edge is elastically deformable. The perimeter of the possible roof head lining 32 and the quarter pillar garnish 33 are to be covered.

The airbag 11 is provided with the inflator 1.
A gas introduction passage Pa having an opening connected to the front end of the gas introduction passage 2 at a rear end thereof; a gas introduction passage Pa extending obliquely downward and forward from the front end of the gas introduction passage Pa to extend substantially linearly in the front-rear direction of the vehicle. An upper front sub-seat expansion chamber Rb and a lower front seat, which are provided in parallel above and below a front portion of the main expansion chamber Ra and extend substantially linearly in the front-rear direction of the vehicle. An upper rear auxiliary expansion chamber Rd and a lower rear auxiliary expansion chamber, which are provided in parallel below the rear expansion section of the main expansion chamber Ra and extend substantially linearly in the longitudinal direction of the vehicle. It has a chamber Re.

The airbag 11 has a communication path Pb for vertically communicating the main inflation chamber Ra with the upper sub-inflation chamber Rb, and a main inflation chamber Ra and a lower sub-inflation chamber for front seat. R
communication paths Pc1 and Pc2 that allow the communication path c to communicate in the vertical direction.
And a communication passage Pd for vertically communicating the main expansion chamber Ra with the upper rear sub-expansion chamber Rd, and vertically communicating the main expansion chamber Ra with the lower rear sub-expansion chamber Re. Communication path Pe.

The inflatable portion 11b for the front seat of the airbag 11
It is mainly constituted by a front portion of the main expansion chamber Ra and a pair of upper and lower auxiliary expansion chambers for front seats Rb and Rc. The rear inflation portion 11c of the airbag 11 mainly includes a rear portion of the main inflation chamber Ra and a pair of upper and lower rear inflation chambers Rd, Re.
It is constituted by. An auxiliary expansion chamber Rf extending forward is formed continuously in front of the upper sub-expansion chamber Rb for the front seat, and the head Hf of the front seat occupant is attached to the front pillar 21 by the auxiliary expansion chamber Rf. It is designed to reduce the impact when abutting.

The inflator 12 is for injecting gas toward the airbag 11 at the time of a side collision of the vehicle or the like. The inflator 12 is disposed obliquely along the quarter pillar 23 and has a bracket 12a provided at the center. It is assembled to the quarter pillar 23 using a bolt 51, and the front end of the quarter pillar 23 is air-tightly fitted into the gas inlet 11 d of the airbag 11. The inflator 12 is covered with a quarter pillar garnish 33 together with the rear end of the gas introduction section 11 d in the airbag 11.

The tension belt 13 is made of a material that is easy to fold and is difficult to extend. One end 13a is fixed to a position above the front non-inflation portion 11e of the airbag 11 by sewing. It is movably inserted into a through hole (slit) 11g provided at a lower position in the non-expandable portion 11e, and the other end 13c is fixed to a lower portion of the front pillar 21 using a fixture (not shown) such as a bolt.

Further, the tension belt 13 is overlapped with the portion where the main inflation chamber Ra is formed in the airbag 11 at an intermediate portion between one end (fixed portion) 13a and the intermediate portion (insertion portion) 13b to form a front seat inflatable portion. The airbag 11 extends along the front edge of the airbag 11b and generates a predetermined tension by the inflation deformation of the front seat inflatable portion 11b (the airbag 11 is large when the airbag 11 is inflated and deployed as shown in FIG. 1). The belt length is set so that tension is generated). When the tension belt 13 is stored along the front pillar 21, the roof side rail 22, and the quarter pillar 23 in a state where the airbag 11 is folded, the tension belt 13 is stored along the front pillar 21, The garnish 31 is covered.

In the first embodiment, each communication path Pb, Pc1, Pc2, Pd, P
A constriction is formed in each of e. The constricted portion of the communication passage Pb is formed corresponding to a non-expanded portion (seam portion) between the main expansion chamber Ra and the sub-expansion chamber Rb for the front seat. The room Rb is easily bent in the left-right direction of the vehicle. The narrow portions of the two communication passages Pc1 and Pc2 are formed corresponding to the non-expandable portion between the main expansion chamber Ra and the sub-expansion chamber Rc for the front seat. Rc is easily bent in the left-right direction of the vehicle.

The narrow portion of the communication passage Pd is formed corresponding to the non-expandable portion between the main expansion chamber Ra and the sub-expansion chamber Rd for the rear seat. Expansion chamber Rd
Is easily bent in the lateral direction of the vehicle. The constricted portion of the communication passage Pe is formed corresponding to the non-expanded portion between the rear sub-expansion chamber Rd and the rear seat sub-expansion chamber Re, and is formed below the upper rear seat sub-expansion chamber Rd. Rear sub-expansion chamber Re
Is easily bent in the lateral direction of the vehicle.

In the first embodiment configured as described above, the airbag 11 is normally folded and housed, and the gas is blown out of the inflator 12 at the time of a side collision of the vehicle. The airbag 1 folded and stored through the gas introduction part 11d of the airbag 1
1, the airbag 11 deforms the front pillar garnish 31 and the peripheral portion of the roof head lining 32 toward the vehicle interior and expands downward, and as shown in FIG. Expands and deploys in a curtain shape at the part. At this time, in the airbag 11, the inflator 1
Each of the expansion chambers Ra to Rf expands into a cylindrical shape by the gas supplied from the fuel cell 2, and each of the communication passages Pb to Pe
Respectively expand into a cylindrical shape.

By the way, in the first embodiment,
The main inflation chamber Ra of the airbag 11 is located at the rear gas introduction portion 11.
Since d extends in a substantially straight line in the front-rear direction of the vehicle,
At the initial stage of deployment of the airbag 11, gas can be quickly flowed into the main inflation chamber Ra. In addition, airbag 1
At the front part of the first part, the gas flows into the upper and lower front seat sub-expansion chambers Rb and Rc by dividing the gas vertically by the inertia force of the gas flowing to the front end of the main expansion chamber Ra. it can. Therefore, the front seat inflatable portion 11b can be quickly inflated from the early stage of the deployment of the airbag 11, and an area capable of restraining the front seat occupant before the inflation and deployment of the airbag 11 is completed can be quickly and widely secured.

In the first embodiment, a constricted portion is formed at a specific portion (a position corresponding to the non-inflated portion) in each of the communication paths Pb to Pe of the airbag 11.
In the constricted portion, the vehicle is easily bent in the left-right direction of the vehicle. Therefore, even when an obstacle is present in the deployment direction of the airbag 11 when the airbag 11 is inflated and deployed, the airbag 11 is easily bent and deformed in the left and right directions of the vehicle at each constricted portion. 11, the force acting on the interference can be reduced, and the deployment direction of the airbag 11 can be strictly controlled.
It is possible to easily prevent a large force from acting on the interfering object from the airbag 11 without controlling the internal pressure.

In the first embodiment, the tension belt 13 for connecting the lower front portion to the front pillar 21 (vehicle body) when the airbag 11 is inflated and deployed,
One end 13a is fixed to a non-inflatable portion above the main inflation chamber Ra of the airbag 11, and the intermediate portion 13b is
The first main inflation chamber Ra of the airbag 11 is movably inserted into a through-hole 11g provided in a non-inflation portion below the first main inflation chamber Ra, and at an intermediate portion between the one end fixing portion 13a and the intermediate insertion portion 13b. A large tension can be generated in the tension belt 13 due to the expansion and deformation of the main expansion chamber Ra because the configuration in which the main expansion chamber Ra overlaps the formation part (straddling the formation part) is adopted.

Therefore, when the airbag 11 is inflated and deployed, the tension belt 13 can be accurately released (pulled out) from the storage portion, and after the airbag 11 is inflated and deployed, the tension belt 13 can be released.
As a result, a sufficient tension can be generated in the lower portion of the airbag 11, and the movement of the airbag 11 to the outside of the vehicle when the occupant is restrained can be accurately suppressed.

In the first embodiment, the two communication paths P
A narrow portion is formed by providing a protruding non-expanding portion at a position corresponding to the non-expanding portion between the main expansion chamber Ra and the sub-expansion chambers Rb and Rc at b and Pc1, but the second embodiment shown in FIG. Alternatively, as in the third embodiment shown in FIG.
It is also possible to form a constricted portion by providing a non-expandable portion in a floating island shape at the corresponding position of b, Pc1. Also in each of these embodiments, since the same function as each of the constricted portions of the first embodiment can be obtained in each of the constricted portions of both communication passages Pb and Pc1, the same operation and effect as that of the first embodiment can be obtained. Is obtained.

In the second embodiment shown in FIG. 2, the tension belt 13 has one end fixing portion 13a and the intermediate insertion portion 1a.
3b, it extends along the front edge of the front seat inflatable portion 11b, and is configured so that a predetermined tension is generated in the tension belt 13 by expansion deformation of the front seat inflatable portion 11b (air The belt length is set so that a predetermined tension is generated when the bag 11 is inflated and deployed.

On the other hand, in the third embodiment shown in FIG. 3, the tension belt 13 has one end 13a fixed to the upper floating island-shaped non-expandable portion by sewing, and the intermediate portion 13b provided in the lower floating island-shaped non-expanded portion. It is movably inserted into the hole 11g, and similarly to the first embodiment, the one-end fixing portion 13 is provided.
Since the main inflation chamber Ra overlaps with the main inflation chamber Ra at an intermediate portion between the a and the intermediate insertion portion 13b, a large tension is generated in the tension belt 13 due to the expansion and deformation of the front seat inflation portion 11b.

In the first embodiment, the main inflation chamber Ra of the airbag 11 and the sub-inflation sub-inflation chamber Rc for the lower front seat are provided.
Are communicated by a pair of front and rear communication passages Pc1 and Pc2. However, as in the fourth embodiment shown in FIG. 4, the main inflation chamber Ra of the airbag 11 and the lower sub-inflation chamber R for the front seat below.
It is also possible to implement such that c is communicated with the rear communication path Pc.

In the fourth embodiment, the main expansion chamber R
a and a communication path P for communicating the upper front seat auxiliary expansion chamber Rb with the upper front seat expansion chamber Rb.
b is offset in front of the vehicle, and the communication path Pc for communicating the main expansion chamber Ra with the lower front seat auxiliary expansion chamber Rc is offset in the rear of the vehicle. Between the front-seat sub-expansion chambers Rb, the portion where the communication path Pb is not arranged, that is, at the rear portion of the vehicle, is easily bent in the left-right direction of the vehicle.
In the area where the communication path Pc is not arranged between the sub-expansion chamber a and the lower front seat expansion chamber Rc, that is, at the area in front of the vehicle, the vehicle is easily bent in the left-right direction of the vehicle.

Therefore, when the airbag 11 is inflated and deployed, the obstacle is located at the front part of the vehicle and the airbag 1
When the airbag 11 interferes with the interfering object, the airbag 11 is easily bent and deformed in the left-right direction of the vehicle at a portion in front of the vehicle between the main inflation chamber Ra and the lower subseat inflation chamber Rc. No large force acts on the interference. Further, when the interfering object is located at the rear part of the vehicle and the airbag 11 interferes with the interfering substance, the airbag 11 is positioned at the rear part of the vehicle between the main inflation chamber Ra and the upper sub-inflation chamber Rb for the front seat. The airbag is easily bent and deformed in the
Therefore, no large force acts on the interference.

In each of the above embodiments, the airbag 1
The present invention is applied to a head protection airbag 10 including a front seat inflatable portion 11b and a rear seat inflatable portion 11c, but the present invention (the invention according to claim 1) uses an inflator for an airbag. A main expansion chamber connected at one end to extend substantially linearly in the front-rear direction of the vehicle, and a sub-expansion chamber provided in parallel with the main expansion chamber and extending substantially linearly in the front-rear direction of the vehicle And a communication passage for vertically communicating the sub-inflation chamber and the main inflation chamber. The head of the occupant is protected from the side by the main inflation chamber and the sub-inflation chamber of the airbag. The present invention can be implemented by appropriately changing to various head protection airbag devices configured as described above, and is not limited to the above embodiments.

In each of the above-described embodiments, the inflatable portion 11b or 11c of the airbag for protecting the occupant's head Hf or Hr from the side is composed of the main inflation chamber Ra and a pair of upper and lower sub-inflation chambers Rb, Rc or Rd. The present invention (the invention according to claim 1) is characterized in that the inflating portion of the airbag for protecting the occupant's head from the side is a single unit with the main inflation chamber. The present invention can be similarly applied to a configuration including one (or three or more) sub-expansion chambers, and is not limited to the above embodiments.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a head protection airbag device according to the present invention.
It is a side view showing the embodiment.

FIG. 2 shows a second embodiment of the head protection airbag device according to the present invention.
It is the partial side view which showed embodiment.

FIG. 3 shows a third embodiment of the head protection airbag device according to the present invention.
It is the partial side view which showed embodiment.

FIG. 4 shows a fourth embodiment of the head protection airbag device according to the present invention.
It is the partial side view which showed embodiment.

[Explanation of symbols]

10 ... Head protection airbag device, 11 ... Airbag, 1
1a: central non-expandable portion; 11b: front-seat inflatable portion;
Rear seat inflatable part, 11d: gas introduction part, 11e: front non-inflatable part, 11f: mounting piece, Pa: gas introduction path, Pb, P
c, Pd, Pe: communication passage, Ra: main expansion chamber, Rb, R
c, Rd, Re: sub-inflation chamber, Hf: head of front seat occupant, H
r: head of rear seat occupant, 12: inflator, 13: tension belt, 13a: one end, 13b: middle part, 13c
... the other end, 21 ... front pillar, 22 ... roof side rail, 23 ... quarter pillar, 31 ... front pillar garnish, 32 ... roof head lining, 33 ...
Quarter pillar garnish.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshinori Tanase 1 Ochiai, Ogai, Kasuga-cho, Nishikasugai-gun, Aichi F-term (reference) 3D054 AA07 AA18 AA20 CC06 CC11 FF20

Claims (3)

[Claims] An airbag that is inflated and deployed in a curtain shape at a side portion of a vehicle interior by supplying gas from an inflator is connected to the inflator at one end and substantially linearly extends in the front-rear direction of the vehicle. A main expansion chamber extending in parallel with the main expansion chamber, and a sub-expansion chamber extending substantially linearly in the front-rear direction of the vehicle; and A head protection airbag device comprising a communication passage for communicating, wherein a head of an occupant is protected from a side in the main inflation chamber and the sub inflation chamber of the airbag, A constricted portion formed at a position corresponding to a non-inflated portion between the main inflation chamber and the sub-inflation chamber in the communication passage. 2. An airbag, which is inflated and deployed in a curtain shape at a side portion of a vehicle interior when gas is supplied from an inflator, is connected to the inflator at one end and substantially linearly extends in the front-rear direction of the vehicle. A main expansion chamber that extends, upper and lower sub-expansion chambers that are provided in parallel above and below the main expansion chamber and extend substantially linearly in the front-rear direction of the vehicle, and vertically move these two sub-expansion chambers and the main expansion chamber. A head protection airbag device having a communication passage for communicating in the same direction, wherein a head of a front occupant is protected from the side in the main inflation chamber and the sub inflation chamber of the airbag. A communication passage that communicates the main expansion chamber and the upper sub-expansion chamber is offset in front of the vehicle, and a communication passage that communicates the main expansion chamber and the lower sub-expansion chamber is offset in the rear of the vehicle. Head protection Abag device. 3. A tension belt that connects a lower portion of the airbag to the vehicle body when the airbag is inflated and deployed has one end fixed to a non-inflation portion above the main inflation chamber of the airbag, and a middle portion to the airbag. And a portion where the main inflation chamber is formed in the airbag at an intermediate portion between the one end fixing portion and the intermediate insertion portion. 3. The head protection airbag device according to claim 1, wherein the head protection airbag device is polymerized.