Airbag

Abstract

To provide an air bag capable of developing an air bag body part in good balance by a simple configuration.SOLUTION: An air bag has a bag-like air bag body part 12 with a gas introduction part 15 into which gas is introduced, a plurality of air chambers 19 which are expanded by the gas introduced from the gas introduction part 15, and a gas guide part 20 which guides the gas introduced from the gas introduction part 15 to the air chambers 19. The gas guide part 20 is provided with: a first gas guide part 27 which guides the gas in a first direction X along a development direction of the air bag body part 12; and a plurality of second gas guide parts 28 which are located near the tip part 27b of the first gas guide part 27 to branch the gas in a second direction Y crossing the first direction X, respectively.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an airbag for protecting the head of an occupant.

Background Art

[0002] Conventionally, for an airbag device equipped with an airbag that is inflated and deployed by introducing gas, there is known a head protection airbag device that covers and protects the head of an occupant of a two-wheeled vehicle such as a bicycle, or that covers and protects the head of an occupant sitting on a seat of an automobile. For example, the airbag main body portion used in such an airbag device includes a plurality of longitudinal air chambers, and these air chambers are arranged side by side. And this airbag main body portion is stored in a folded state, and is inflated and deployed by gas introduced from near the back of the head, so as to cover a portion extending from the back of the head to both sides of the head and across the front of the head.

[0003] In the airbag main body portion, in order to branch the gas introduced into the interior from below to above in the left-right direction, a gas flow path, a sleeve, etc. are formed in the immediate vicinity of the gas introduction portion or facing the gas introduction portion (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the vicinity of the gas introduction part, since the momentum of the introduced gas is strong, the gas strongly flows upward, and with only the gas flow path in the left - right direction, the inflow amount of the gas to the left and right is limited. Also, in the case of a sleeve that guides the gas in the left - right direction, while the gas is introduced into the left - right direction promptly, the inflow of the gas upward is delayed. Therefore, in order to deploy the airbag main body evenly to the upper side and both the left and right sides, a separate configuration is required, etc., increasing the manufacturing cost.

[0006] The present invention has been made in view of such points, and an object thereof is to provide an airbag capable of deploying the airbag main body in a well - balanced manner with a simple configuration.

Means for Solving the Problems

[0007] The airbag according to claim 1 is an airbag that protects the head of an occupant by being inflated and deployed when gas is introduced from a folded state, and includes a gas introduction part into which gas is introduced, a plurality of air chambers inflated by the gas introduced from this gas introduction part, and a gas guide part that guides the gas introduced from the gas introduction part to the air chambers, and has a bag - shaped airbag main body part. The gas guide part includes a first gas guide part that guides the gas in a first direction along the deployment direction of the airbag main body part, and a plurality of second gas guide parts that are located near the tip of the first gas guide part and branch the gas in a second direction intersecting the first direction. Each of the second gas guide parts is located away from the tip of the first gas guide part toward the first direction side, so that the space between the base end part of each second gas guide part and the tip of the first gas guide part serves as a vent. and at the same time, the base ends of each other are separated from each other in the second direction so as to be air-permeable is the one.

[0008] Please Claim 2 The airbag described in the claim is described in claim 1 In the airbag described in the claim, each of the second gas guide parts is formed along the second direction.

[0009] Claim 3 The airbag described in the claim is described in claim 1or 2 In the airbag described, each second gas guide part is inclined in a direction opposite to the first direction from the base end part toward the tip end part.

[0010] The airbag according to claim 4 is the airbag according to any one of claims 1 to 3, wherein the air chamber includes head air chambers located on both sides of the occupant's head, and a chuck connected to the tip end part of the head air chamber by a connecting body, and a plurality of first gas guide parts are arranged to be separated from each other in a second direction and extend along a direction intersecting the head air chamber. , in the inflated and deployed state, the air chamber for the neck portion expands and inclines in a direction away from each other from the front to the rear of the occupant The base end part of the first gas guide part set by the interval of The bending of the head air chamber behind the occupant in the inflated and deployed state position The interval is set to be larger than the length of the chuck or the connector is such.

Advantages of the Invention

[0011] According to the airbag described in claim 1, a plurality of second gas guide parts for branching the gas in the second direction are arranged near the tip end part of the first gas guide part that guides the gas in the first direction along the deployment direction of the airbag main body part, and each second gas guide part is positioned away from the tip end part of the first gas guide part toward the first direction side, so that the space between the base end part of each second gas guide part and the tip end part of the first gas guide part serves as a vent port. and at the same time, separate the base ends of each second gas guide portion in the second direction As a result, the gas guided in the first direction by the first gas guide part and having a lower flow rate than the position of the gas introduction part a part of can be reliably guided in the second direction by the second gas guide part and introduced from the vent port into the air chamber. and at the same time, the remaining gas guided in the first direction by the first gas guide portion flows in the first direction between the base ends of the second gas guide portion Therefore, the first gas guide part and the second gas guide part can efficiently branch the gas in the first direction and the second direction respectively, and it is possible to deploy the airbag main body part in a well-balanced manner with a simple configuration.

[0012] Please Item 2 According to the airbag described, according to claim 1In addition to the effects of the airbag described, since each second gas guide portion is formed along the second direction, each second gas guide portion can more reliably branch the gas in the second direction.

[0013] Claim 3 According to the airbag described in claim 1 or 2 In addition to the effects of the airbag described, by inclining each second gas guide portion from the base end portion toward the tip end portion in a direction opposite to the first direction, when guiding the gas in the second direction by each second gas guide portion, the flow velocity component of the gas toward the first direction side can be suppressed, and the airbag main body portion can be made less likely to be pulled in the first direction by the flow velocity of the gas.

[0014] According to the airbag described in claim 4, in addition to the effects of the airbag described in any one of claims 1 to 3 , in the inflated and deployed state, the air chamber for the neck portion expands and inclines in a direction away from each other from the front to the rear of the occupant The base end portion of the first gas guide portion set by the interval of The bending of the neck air chamber behind the occupant in the inflated and deployed state position The interval set to be larger than the length of the chuck or the connector By doing so be able to contact the vicinity of the front portion of the air chamber for the neck portion on both sides of the neck of the occupant respectively .

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0016] Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

[0017] In FIG. 3, reference numeral 10 denotes an airbag. The airbag device 11 provided with this airbag 10 is a head protection airbag device that protects the head A of an occupant such as a cyclist who is a moving body. In the present embodiment, this airbag device 11 is, for example, a two-wheeler airbag device worn around the occupant's neck. Hereinafter, the front-rear direction (arrow FR direction and arrow RR direction), the left and right side directions (arrow L direction and arrow R direction shown in FIG. 1), and the up-down direction (arrow U direction and arrow D direction) will be described with reference to the state where the occupant wears the airbag device 11 as a reference.

[0018] And this airbag device 11, which can also be called an airbag module, in addition to the above-mentioned airbag 10 having an airbag main body portion 12 which is a bag-shaped outer shell portion, includes an inflater for supplying gas to the airbag main body portion 12, control means for controlling the operation of the inflater, and a battery (secondary battery) serving as a power source for these. And this airbag device 11, together with the airbag 10 (airbag main body portion 12) in a folded state by a predetermined method, the inflater, the control means, the battery, etc. are housed inside a cover 13 which is a bag body made of, for example, cloth, and is wound around the occupant's neck and worn.

[0019] The inflator includes a main body portion having a disk shape, a cylindrical shape, or the like. Inside the main body portion, an igniter and a chemical agent are stored, and the igniter burns the chemical agent by an electrical signal from control means transmitted through a connected connector, and rapidly supplies inflation gas from a gas injection port formed in the main body portion into the airbag main body portion 12.

[0020] The control means includes a sensor for detecting an impact and a control device, and this control device is connected to the inflator via a signal line and is configured to operate the inflator when the sensor detects a predetermined impact.

[0021] And the airbag main body portion 12 shown in FIG. 1 is formed as a bag as a whole by combining and joining one or a plurality of base fabrics by sewing, adhesion, welding, or the like. That is, the airbag main body portion 12 may be formed by weaving a bag with a so-called one-piece woven (One Piece Woven, OPW) with a single base fabric, or may be formed in a bag shape by joining two or more base fabrics by sewing or the like. Further, this airbag main body portion 12 includes a gas introduction portion 15 into which gas is introduced from the inflator, an inflation portion 16 that expands by the gas introduced from the gas introduction portion 15, and a non-inflation portion 17 into which gas is not introduced. And this airbag main body portion 12 is joined by a joining portion 18 (FIG. 4) formed by sewing or the like, and is formed in a helmet-like three-dimensional shape that covers the head from around the occupant's neck in the inflated and deployed state.

[0022] The gas introduction portion 15 is formed as an opening portion. This gas introduction portion 15 is a portion on the deployment base end side of the airbag main body portion 12. In the present embodiment, this gas introduction portion 15 is located at the rear portion around the occupant's neck. For example, a part of the main body portion of the inflator may be inserted into this gas introduction portion 15.

[0023] The inflatable portion 16 includes a plurality of air chambers (chambers) 19 that expand upon introduction of gas from the gas introduction portion 15. Further, a gas guide portion 20 for controlling the flow of gas introduced into the air chamber 19 is formed in the inflatable portion 16.

[0024] In the air chamber 19, a plurality of first air chambers 22 extending along the left - right direction and a plurality of second air chambers 23 extending radially are defined.

[0025] Each first air chamber 22 is an air chamber into which gas is directly introduced from the gas introduction portion 15 via an inflator. Each first air chamber 22 is an air chamber for the neck portion located on both side portions of the occupant's neck. Each first air chamber 22 is formed longitudinally in the left - right direction and protrudes from the gas introduction portion 15 in the left direction and the right direction, respectively. Then, as shown in FIGS. 2(a) and 2(b), the tip ends of each other of the first air chambers 22 are connected at the position of the non - inflatable portion 17 by a chuck (fastener) 24 which is a gap adjusting portion, and thus are wound around the occupant's neck so as to face each other at the front portion of the occupant's neck and are positioned, and are configured to protect the occupant's neck in the inflated and deployed state. The chuck 24 can adjust the gap W1 between the first air chambers 22 at the front position of the occupant in the airbag main body portion 12. For example, in one example shown in FIG. 2(a), the gap W1 is set relatively small, and in another example shown in FIG. 2(b), the gap W1 is set relatively large. The chuck 24 is connected to the non - inflatable portion 17 at the tip end side of the first air chamber 22 by a connecting body, for example, a connecting cloth.

[0026] Each second air chamber 23 shown in FIG. 1 is located above each first air chamber 22 and is arranged side by side left and right. In the present embodiment, each second air chamber 23 is arranged symmetrically, for example. In the present embodiment, three second air chambers 23 are formed on each of the left and right sides and one is formed in the central portion, but it is not limited to this number and shape. Further, each second air chamber 23 is, for example, in the state of the base fabric before being joined by the joint portion 18, and is opened and extended in a finger-like shape so that the distance of the edge portion gradually increases from the base end side (lower side) toward the tip side (upper side). Therefore, in the present embodiment, between the second air chambers 23, there is a notch portion 25 in the state of the base fabric before being joined by the joint portion 18, and the second air chambers 23 are formed separately from each other. And each second air chamber 23 is configured to protect the position extending from the rear portion to both side portions and the front portion of the head A of the occupant in the inflated and deployed state. Further, the second air chamber 23 located at the rear portion of the head A of the occupant is set to have a larger thickness in the front-rear direction.

[0027] The gas guide portion 20 guides the gas introduced from the gas introduction portion 15 to the air chamber 19. In the present embodiment, this gas guide portion 20 includes a first gas guide portion 27 that is located close to the gas introduction portion 15 and guides the gas in a first direction (upward) X along the deployment direction of the airbag main body portion 12, and a second gas guide portion 28 that guides the gas from the first gas guide portion 27 in a second direction (left and right) Y that intersects or is orthogonal to the first direction X. Further, the gas guide portion 20 may further be provided with a third gas guide portion 29 that guides the gas further upward and left and right from the first gas guide portion 27. The gas guide portion 20 is formed, for example, by joining the base fabric by sewing or the like.

[0028] The first gas guide portions 27 are respectively formed along the first direction X at positions close to both sides of the gas introduction portion 15 in the airbag main body portion 12. That is, each first gas guide portion 27 is disposed at a position extending from the rear side of the occupant's neck to the back of the head in the inflated and deployed state of the airbag main body portion 12. The first gas guide portions 27, 27 are positioned apart from each other in the second direction Y. Each first gas guide portion 27 has a base end portion (lower end portion) 27a located within the width of the first air chamber 22 in the first direction X at a predetermined distance from the gas introduction portion 15 in the first direction X, and a tip end portion (upper end portion) 27b located within the width of the second air chamber 23 adjacent to the first air chamber 22 in the first direction X. For this reason, the position between the base end portion 27a of each first gas guide portion 27 and the gas introduction portion 15 serves as a branch port 31 where the gas branches into each first air chamber 22. Further, the first gas guide portions 27, 27 extend along a direction intersecting the first air chamber 22, and the position including the base end portion 27a of each first gas guide portion 27 sets the bending position of the first air chamber 22 behind the occupant in the inflated and deployed state of the airbag main body portion 12. Therefore, depending on the interval between the first gas guide portions 27, 27, in this embodiment, the interval between the base end portions 27a, 27a, as shown in FIGS. 2(a) and 2(b), a gap W2 of the first air chamber 22 at the rear position of the occupant is set. For example, in an example shown in FIG. 2(a), the gap W2 is set relatively large, and in another example shown in FIG. 2(b), the gap W2 is set relatively small, and for example, with respect to the gap W2, the gap W1 is more than half of the gap W2. Here, the gap W1 due to the length of the chuck 24 or the length of the connecting cloth and the gap W2 due to the interval between the base end portions 27a, 27a of the first gas guide portions 27, 27 are set to have a negative correlation with each other, that is, when one is increased, the other is decreased, so that the gaps W1 and W2 can be adjusted without changing the length of each first air chamber 22, that is, the capacity of each first air chamber 22. In the example shown in FIG. 2(a), since the gap W1 is set relatively small and the gap W2 is set relatively large, each first air chamber 22 is inclined so as to expand in a direction away from each other from the front to the rear.Further, in the example shown in FIG. 2(b), since the gap W1 is set to be relatively large and the gap W2 is set to be relatively small, each first air chamber 22 is longitudinally shaped along the front-rear direction and is positioned so as to be arranged substantially parallel to each other.

[0029] Further, each first gas guide portion 27 is formed to be inclined so as to gradually approach each other from the base end portion 27a toward the tip end portion 27b. Therefore, the first gas guide portions 27, 27 are arranged in a V shape when viewed from the front. And, between the tip end portions 27b of each first gas guide portion 27, there is an inlet 32 for gas to flow into the second gas guide portion 28 and the third gas guide portion 29. Further, between each first gas guide portion 27 and the gas introduction portion 15, there is a first space portion 33 for the gas introduced from the gas introduction portion 15 to branch into the branch port 31 and the inlet 32. The first space portion 33 is formed such that the side of the gas introduction portion 15 is wide and the side of the inlet 32 is narrow because each first gas guide portion 27 gradually approaches from the base end portion 27a toward the tip end portion 27b.

[0030] The second gas guide portion 28 is formed along the second direction Y at positions in the airbag main body portion 12 near the tip portion 27b of the first gas guide portion 27. That is, each second gas guide portion 28 is arranged at a position extending across the heads on both the left and right sides of the occupant in the inflated and deployed state of the airbag main body portion 12. Each second gas guide portion 28 is located on the first direction X side with respect to each first gas guide portion 27. That is, the entire second gas guide portion 28 from the base end portion 28a to the tip portion 28b is located on the first direction (upward) X side with respect to the first gas guide portion 27. Further, each second gas guide portion 28 is located away from the tip portion 27b of the first gas guide portion 27 in the first direction X and the second direction Y. Furthermore, in the present embodiment, each second gas guide portion 28 is formed in a linear shape that gradually inclines toward the first direction X from the base end portion 28a that is relatively close to the first gas guide portion 27 to the tip portion 28b that is relatively far from the first gas guide portion 27. Specifically, in the present embodiment, each second gas guide portion 28 is formed to extend in an upward left and right diagonal direction. For this reason, each second gas guide portion 28 in the present embodiment is formed along a direction having components of the first direction X and the second direction Y. Further, the tip portion 28b of each second gas guide portion 28 is located close to the non-inflated portion 17 between adjacent second air chambers 23. For this reason, between the base end portion 28a of each second gas guide portion 28 and the tip portion 27b of each first gas guide portion 27, there are vent holes 35 that communicate with both sides of the inlet port 32. Each vent hole 35 is opened toward each second air chamber 23 adjacent to the first air chamber 22.

[0031] The third gas guide portion 29 is located entirely on the X side (the first direction) away from the first gas guide portion 27 in the airbag main body portion 12. Also, the third gas guide portion 29 is formed along the first direction X at the central portion or substantially central portion of the airbag main body portion 12. That is, the third gas guide portion 29 is arranged at a position extending from the rear head portion of the occupant to the vicinity of the top of the head in the inflated and deployed state of the airbag main body portion 12. The proximal end portion (lower end portion) 29a of this third gas guide portion 29 is located on the X side (the first direction) away from the distal end portion 27b of the first gas guide portion 27 and is arranged at a substantially intermediate position between the proximal end portions 28a of the second gas guide portions 28. Also, the distal end portion (upper end portion) 29b of the third gas guide portion 29 is located on the X side (the first direction) with respect to the second gas guide portion 28. For this reason, between the proximal end portion 29a of the third gas guide portion 29 and the proximal end portions 28a of the second gas guide portions 28, there are vent holes 36 that communicate with the inlet 32 and the vent holes 35. Each vent hole 36 is opened toward the remaining second gas chambers 23 that are not adjacent to the first gas chamber 22. Also, between the proximal end portion 29a of the third gas guide portion 29, the distal end portions 27b of the first gas guide portions 27, and the proximal end portions 28a of the second gas guide portions 28, there is a second space portion 37 for the gas flowing in from the inlet 32 to branch into the vent holes 35 and 36. The second space portion 37 is located in the vicinity of the rear head portion of the occupant in the present embodiment.

[0032] The non-inflatable portion 17 is formed in a fin shape along the outer edge of each air chamber 19 of the inflatable portion 16 in the state of the base fabric before being joined by the joining portion 18. The non-inflatable portion 17 of the present embodiment is formed, for example, as the joining margin (seam margin) of the air chamber 19 in the base fabric.

[0033] The joint portion 18 is formed by, for example, sewing or the like, and gathers the positions of the non-inflated portions 17 on the tip side of the second air chamber 23. In the present embodiment, for example, from the state of the base fabric shown in FIG. 4(a), as shown in FIG. 4(b), in a state where a part of the second air chambers 23 arranged side by side left and right adjacent to each other are overlapped, as shown in FIG. 4(c), the tip side of the second air chamber 23 is joined by sewing or the like to form the joint portion 18. For this reason, due to the joint portion 18, as shown in FIG. 4(d), a part of the adjacent second air chambers 23 overlap each other in the left-right direction and the up-down direction, and these second air chambers 23 are integrated in a state of being close to each other in the left-right direction. More specifically, the adjacent second air chambers 23 are arranged so as to overlap obliquely from the top of the occupant's head to both sides of the head in the airbag main body portion 12, and the airbag main body portion 12 is arranged in a three-dimensional shape. That is, the second air chambers 23 are arranged to overlap so that the deployment tip side of the airbag main body portion 12 narrows.

[0034] Next, the deployment operation of the airbag device will be described.

[0035] As an outline of the operation of this airbag device, when a predetermined impact is detected by a sensor during a collision of a two-wheeled vehicle or the like, the control device operates the inflator, and gas is injected from this inflator. Then, the gas injected from the inflator flows into the inside of the airbag main body portion 12 from the gas introduction portion 15, and is introduced into the first air chamber 22 and the second air chamber 23 by the gas guide portion 20 respectively. The airbag main body portion 12 expands and deploys from the folded state, and breaks and protrudes a part of the cover 13 at the deployment pressure, covering the occupant's head A from the back of the head to the front of the head.

[0036] More specifically, when gas is introduced from the inflator into the interior of the airbag main body 12 via the gas introduction portion 15, the first space portion 33 first expands at a position behind the occupant's neck by this gas, and the first space portion 33 suppresses the airbag main body 12 from being pulled in the first direction (upward) X. Next, the gas branches from the first space portion 33 to the inlet 32 and each branch port 31, and when the gas is introduced from each branch port 31 into each first air chamber 22 and each first air chamber 22 expands, the gas guided in the first direction (upward) X between each first gas guide portion 27 is introduced from the inlet 32 into the second space portion 37. In this second space portion 37, the remaining gas that has already been branched into the first air chambers 22 is introduced, and since the gas inflow rate is lower than that of the first space portion 33 due to passing through the inlet 32 or the like, each second gas guide portion 28 and the third gas guide portion 29 that are separated from each first gas guide portion 27 (inlet 32) in the first direction X effectively branch the gas from this second space portion 37 to each vent 35, 36, and the gas is introduced into each second air chamber 23 and each second air chamber 23 expands.

[0037] As a result, as shown in FIGS. 3(a) to 3(d), the airbag main body 12 expands while falling forward so as to wrap around the upper part and both side parts of the occupant's head A from behind along the upper part and both side parts of the occupant's head A as the introduced gas passes from the proximal end side to the distal end side in the second air chamber 23. For this reason, as shown in FIG. 3(e) or FIG. 3(f), the first air chamber 22 expands and unfolds around the occupant's neck N, and as shown in FIG. 3(d), the second air chamber 23 unfolds into a rounded three-dimensional shape that conforms to the shape of the head A (wrapping the head A from behind). That is, the inflating portion 16 unfolds in a pocket shape (semi-dome shape) with the occupant-facing portion facing the occupant's head A on the inside.

[0038] Thus, according to this embodiment, a plurality of second gas guide portions 28 that branch the gas in the second direction Y are arranged near the tip portion 27b of the first gas guide portion 27 that guides the gas in the first direction X along the deployment direction of the airbag main body portion 12. As a result, the second gas guide portion 28 can guide the gas that has been guided by the first gas guide portion 27 and has a reduced flow velocity compared to the position of the gas introduction portion 15. Therefore, the first gas guide portion 27 and the second gas guide portion 28 can efficiently branch the gas in the first direction X and the second direction Y respectively, and it is possible to deploy the airbag main body portion 12 in a well-balanced manner with a simple configuration.

[0039] For example, when the second gas guide portion 38 is located on the side opposite to the first direction X with respect to the tip portion 39b of the first gas guide portion 39 as in the airbag device 11a of the comparative example shown in FIGS. 5(a) to 5(e), the flow velocity of the gas guided in the first direction X by the first gas guide portion 39 does not decrease at the position of the second gas guide portion 38. Instead, the airbag main body portion 12a expands greatly in the first direction (upward) X with respect to the head A of the occupant from the gas introduction portion 15 by the first gas guide portion 39 and is not effectively branched by the second gas guide portion 38, resulting in a delay in the deployment of the airbag main body portion 12a in the second direction (left - right direction) Y. In contrast, in this embodiment, the gas can be efficiently branched in the first direction X and the second direction Y, and the airbag main body portion 12 can be deployed in a well - balanced manner, resulting in a deployment along the head A of the occupant and an improvement in the protection performance.

[0040] Specifically, since each second gas guide portion 28 is located on the first direction X side with respect to the first gas guide portion 27, the gas guided to the first direction X side by the first gas guide portion 27 can be more reliably branched to the second direction Y by each second gas guide portion 28.

[0041] Furthermore, since each second gas guide portion 28 is formed along the second direction Y, each second gas guide portion 28 can more reliably branch the gas to the second direction Y.

[0042] Further, since each second gas guide portion 28 is inclined in the first direction (upward) X from the base end portion 28a toward the tip end portion 28b with respect to the second direction Y, it is possible to smoothly guide the gas guided by the first gas guide portion 27 to the second direction Y without sharply changing the direction of the gas by each second gas guide portion 28.

[0043] Furthermore, when gas is introduced from the gas introduction portion 15 into the airbag main body portion 12, first, the first space portion 33 expands, so that the expanded first space portion 33 acts as a physical stopper, and the airbag main body portion 12 can be made less likely to be pulled in the first direction (upward) X by the gas flow rate. Moreover, since the first space portion 33 is wider on the gas introduction portion 15 side than on the inlet port 32 side, the position closer to the gas introduction portion 15, closer to the base end portion 27a side of the first gas guide portion 27 (lower position) expands more, and the airbag main body portion 12 can be made less likely to be pulled in the first direction (upward) X compared to the case where a position far from the gas introduction portion 15 expands.

[0044] Also, by adjusting the interval between the first gas guide portions 27, 27 extending along the direction intersecting the chuck 24, the width of the inflated and deployed shape of the airbag body portion 12 is adjusted at the positions before and after the occupant's neck N, and the gap between the neck N and the first air chamber 22 can be freely set. For example, in the example shown in FIG. 3(e), since each first air chamber 22 of the airbag body portion 12 expands and deploys in a circular shape when viewed from below or above, the vicinity of the front portion of the first air chamber 22 can be brought into contact with both sides of the occupant's neck N, respectively. On the other hand, in the example shown in FIG. 3(f), since each first air chamber 22 of the airbag body portion 12 expands and deploys in an elliptical shape or an oval shape that is long in the front-rear direction when viewed from below or above, the vicinity of the central portion in the front-rear direction, which is the longitudinal direction of the first air chamber 22, can be brought into contact with both sides of the occupant's neck N, respectively, and gaps can be formed in front of and behind the neck N. In the case of the airbag 10 of the present embodiment, since the inflated and deployed airbag body portion 12 has a thickness in the front-rear direction in the second air chamber 23 at the position of the occupant's occipital region, a large gap between the rear portion of the occupant's head A and the second air chamber 23 cannot be taken, and as shown in FIG. 6, the airbag body portion 12 is likely to interfere with the rear portion of the occupant's head A, and due to the interference margin OL, the airbag body portion 12 moves backward. Therefore, when increasing the gap in front of the neck N, even if the airbag body portion 12 moves backward, compression of the occupant's throat portion can be suppressed.

[0045] Further, by providing a negative correlation between the adjustment of the gap W1 by the chuck 24 and the adjustment of the gap W2 by the interval of the first gas guide portions 27, the capacity of the first air chamber 22 is not increased, so that the gap between the neck N and the first air chamber 22 can be freely set without degrading the occupant restraint performance and deployment speed of the airbag 10.

[0046] In addition, in the above-described first embodiment, there are no restrictions on the angle and length between the first gas guide portion 27 and the second gas guide portion 28, and it is only necessary that the second gas guide portion 28 is located in the vicinity of the tip portion 27b of the first gas guide portion 27. Therefore, as in the second embodiment shown in FIG. 7, each second gas guide portion 28 may be inclined in a direction opposite to the first direction X (downward) from the base end portion 28a toward the tip end portion 28b with respect to the second direction Y. In this case, when guiding the gas in the second direction Y by each second gas guide portion 28, the flow velocity component of the gas toward the first direction (upward) X side can be suppressed, and the airbag main body portion 12 can be made less likely to be pulled in the first direction (upward) X by the flow velocity of the gas.

[0047] Also, as in the third embodiment shown in FIG. 8, even if each second gas guide portion 28 is formed in the left-right direction along the second direction Y, the first gas guide portion 27 and the second gas guide portion 28 can efficiently branch the gas in the first direction X and the second direction Y respectively, and the airbag main body portion 12 can be deployed in a well-balanced manner with a simple configuration. Further, the third gas guide portion 29 is not limited to one, and a plurality of them may be formed on the left and right.

[0048] Furthermore, in each of the above embodiments, the airbag device can also be used as an airbag device disposed, for example, on a headrest located behind the head A of an occupant sitting on a seat in an automobile.

Industrial Applicability

[0049] The present invention can be suitably used, for example, as a head protection airbag device for a two-wheeled vehicle.

Explanation of Reference Numerals

[0050] 10 Airbag 12 Airbag main body portion 15 Gas introduction portion 19 Air chamber 20 Gas guide portion 22 First air chamber which is an air chamber for the neck 24Ch Jack 27 First gas guide part 27b Tip part 28 Second gas guide part 28a Base end part 28b Tip part 35 vent A Head N Head part X First direction Y Second direction

Claims

1. An airbag that protects a passenger's head by being inflated and deployed when gas is introduced from a folded state, comprising a gas introduction part into which gas is introduced, a plurality of air chambers inflated by the gas introduced from this gas introduction part, and a gas guide part that guides the gas introduced from the gas introduction part to the air chambers, and having a bag-shaped airbag main body part, wherein the gas guide part has a first gas guide part that guides gas in a first direction along the deployment direction of the airbag main body part, and a plurality of second gas guide parts that are located near the tip of the first gas guide part and branch the gas in a second direction intersecting the first direction, each of the second gas guide parts is located away from the tip of the first gas guide part toward the first direction side, so that a vent is formed between the base end of each second gas guide part and the tip of the first gas guide part, and the base ends of each other are separated in the second direction so that they can communicate with each other characterized in that it is an airbag.

2. Each of the second gas guide parts is formed along the second direction characterized in that it is the airbag according to Claim 1.

3. Each of the second gas guide parts is inclined in a direction opposite to the first direction from the base end toward the tip characterized in that it is the airbag according to Claim 1 or 2.

4. The air chamber includes head air chambers located on both sides of the passenger's neck, and has a chuck connected by a connecting body to the tip of the head air chamber, a plurality of first gas guide parts are arranged apart from each other in the second direction, extend along a direction intersecting the head air chamber, and in the inflated and deployed state, the head air chamber expands and inclines in a direction away from each other from the front to the rear of the passenger, so that the interval between the bending positions of the head air chamber at the rear of the passenger in the inflated and deployed state set by the interval between the base ends of the first gas guide parts is set to be larger than the length of the chuck or the connecting body characterized in that it is the airbag according to any one of Claims 1 to 3.

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