Airbags and airbag systems for seat belt systems

Abstract

The present invention provides an airbag for a seat belt system and an airbag system that can reduce the load on the central part of the body. [Solution] The seat belt device airbag 1 is an airbag for a seat belt device that restrains a seated occupant H to a seat S using webbing W that forms a shoulder belt portion SB that is stretched from the shoulder to the waist of the occupant H, and comprises a cross chamber 2 that is arranged on the shoulder belt portion SB and is capable of inflating and deploying toward both sides in a direction intersecting the longitudinal direction of the shoulder belt portion SB, and a distribution chamber 3 that is arranged at both ends of the cross chamber 2 so as to be able to communicate with the cross chamber 2 and is capable of inflating and deploying toward the occupant H.

Description

Technical Field

[0001] The present invention relates to an airbag for a seatbelt device and an airbag device, and particularly relates to an airbag for a seatbelt device disposed in a seat on which an occupant sits and a seatbelt device.

Background Art

[0002] Vehicles such as automobiles are generally provided with a three-point seatbelt device that restrains an occupant on a seat including a seat cushion portion on which the occupant sits and a backrest portion positioned at the back of the occupant. Such a seatbelt device includes a webbing that restrains the occupant, a seatbelt retractor that winds up the webbing, a buckle disposed on a side surface of the seat, and a tongue disposed on the webbing, and the occupant is restrained on the seat by the webbing by fitting the tongue into the buckle.

[0003] When the seatbelt is fastened, the webbing forms a shoulder belt portion that extends from the occupant's shoulder to the waist and a lap belt portion that extends across both of the occupant's waist portions. In the event of a vehicle collision, the lap belt restrains the occupant's waist, and the shoulder belt portion restrains the occupant's shoulder. Generally, in the event of a frontal collision of a vehicle, the occupant tends to move forward due to inertial force, so the waist is restrained, the webbing of the shoulder belt portion is pulled out by the force limiter of the seatbelt device, and the upper body of the occupant is moved forward as if bowing, thereby reducing the load applied by the shoulder belt portion.

[0004] Even with a seatbelt device having such a force limiter, since the width of the webbing of the shoulder belt portion is narrow, the load applied to the occupant's chest may be large in some cases. Accordingly, several methods have already been proposed for reducing the load input from the shoulder belt portion to the occupant's upper body and suppressing the movement of the occupant's upper body during a vehicle collision.

[0005] For example, Patent Document 1 discloses an air belt device in which a bag is stored inside a shoulder belt that restrains the occupant to the seat, and when the vehicle collides, the bag is inflated with high-pressure gas generated by an inflator, and when the internal pressure of the bag reaches an appropriate value, a control valve opens and the excess gas inside the bag is discharged into the atmosphere through a vent hole, thereby maintaining the internal pressure of the bag at an appropriate level and enhancing the impact absorption effect.

[0006] Furthermore, Patent Document 2 discloses that, in order to suppress the movement of the head and neck relative to the upper body during a vehicle collision, the belt airbag has a belt-direction deployment section that extends and deploys along the shoulder belt section, and a cross-direction deployment section that extends and deploys in a direction intersecting the shoulder belt section. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-213256 [Patent Document 2] Japanese Patent Publication No. 2017-178144 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in the inventions described in Patent Document 1 and Patent Document 2, the occupant's upper body is supported by contacting a belt with a built-in bag or a belt airbag with the occupant's chest, which tends to place a large load on the central part of the body (chest) where vital organs are located.

[0009] This invention was conceived in view of the aforementioned problems, and aims to provide an airbag for a seat belt system and an airbag system that can reduce the load on the central part of the body. [Means for solving the problem]

[0010] According to the present invention, there is an airbag for a seat belt device that is arranged in a seat belt device that restrains a seated occupant to a seat using webbing including a shoulder belt portion that is stretched from the occupant's shoulder to his waist, and the airbag for a seat belt device is provided, characterized in that it includes a cross chamber arranged in the shoulder belt portion and capable of inflating and deploying toward both sides in a direction intersecting the longitudinal direction of the shoulder belt portion, and a distribution chamber arranged at both ends of the cross chamber so as to be able to communicate with the cross chamber and capable of inflating and deploying toward the occupant.

[0011] The crossing chamber may be bonded to the outer surface of the webbing.

[0012] The dispersion chamber may include a first dispersion chamber that inflates and deploys near the occupant's shoulder and a second dispersion chamber that inflates and deploys near the lower part of the occupant's chest.

[0013] The dispersion chamber may have a shape that is elongated in the vertical direction.

[0014] The distribution chamber may include a first distribution chamber positioned on either the left or right side of the center of the occupant's chest, and a second distribution chamber positioned on the other side of the center of the occupant's chest.

[0015] The first and second dispersion chambers may have a vertically elongated shape that extends to a position near the occupant's head.

[0016] The dispersion chamber may include a head protection membrane connected to the tip of the first dispersion chamber and the second dispersion chamber and stretched over the occupant's face.

[0017] Furthermore, the present invention provides an airbag device characterized by being equipped with any of the above-described airbags for seat belt devices.

[0018] The airbag apparatus may comprise an inflator that supplies inflation gas to the intersecting chamber or the dispersion chamber.

[0019] The airbag apparatus may comprise a storage cover that stores the airbag for the seatbelt apparatus folded into a shape conforming to the webbing. Effects of the Invention

[0020] According to the above-described airbag for a seatbelt apparatus and the airbag apparatus pertaining to the present invention, when the inflated and deployed dispersion chamber comes into contact with an occupant, the intersecting chamber can be moved away from the occupant, a force directed away from the occupant can be applied to the webbing, and the load applied to the center region of the body can be reduced. Brief Description of the Drawings

[0021] [Figure 1] It is an explanatory diagram showing the airbag for a seatbelt apparatus pertaining to a first embodiment of the present invention, where (A) is a front view and (B) is a side view. [Figure 2] It is a diagram showing the operation of the airbag for a seatbelt apparatus shown in Fig. 1, where (A) corresponds to the first embodiment and (B) corresponds to a comparative example. [Figure 3] It is an explanatory diagram showing the configuration of the airbag for a seatbelt apparatus shown in Fig. 1, where (A) is an exploded view of components, (B) is a diagram showing a state during suturing, and (C) is a diagram showing a completed state. [Figure 4] It is a plan view showing modified examples of a method for joining the intersecting chamber and the webbing, where (A) shows a first modified example and (B) shows a second modified example. [Figure 5] It is an explanatory diagram showing an example of a storage method for an airbag for a seatbelt apparatus, where (A) is a diagram showing folding lines and (B) is a diagram showing the state of the folded airbag for a seatbelt apparatus before it is stored in the storage cover. [Figure 6] It is an overall configuration diagram showing an airbag apparatus provided with the airbag for a seatbelt apparatus pertaining to the first embodiment of the present invention. [Figure 7] It is an explanatory diagram showing the state before inflation and deployment of the airbag for a seat belt device in the airbag device shown in Fig. 6, wherein (A) is a front view and (B) is a side view. [Figure 8] It is an explanatory diagram showing the airbag for a seat belt device according to the second embodiment of the present invention, wherein (A) is a front view and (B) is a side view. DESCRIPTION OF EMBODIMENTS

[0022] Hereinafter, embodiments of the present invention will be described with reference to Fig. 1(A) to Fig. 8(B). Here, Fig. 1 is an explanatory diagram showing the airbag for a seat belt device according to the first embodiment of the present invention, wherein (A) is a front view and (B) is a side view. Fig. 2 is a diagram showing the operation of the airbag for a seat belt device shown in Fig. 1, wherein (A) shows the first embodiment and (B) shows a comparative example.

[0023] The airbag 1 for a seat belt device according to the first embodiment of the present invention is disposed in a seat belt device that restrains a seated occupant H to a seat S by using a webbing W forming a shoulder belt portion SB stretched from the shoulder to the waist of the occupant H, for example, as shown in Fig. 1(A) and Fig. 1(B). In Fig. 1(A) and Fig. 1(B), the case where a human dummy is used as the occupant H is illustrated.

[0024] The airbag 1 for a seat belt device includes: a cross chamber 2 disposed on the shoulder belt portion SB and inflatable and deployable toward both sides in a direction intersecting the longitudinal direction of the shoulder belt portion SB; and dispersion chambers 3 disposed at both ends of the cross chamber 2 to be able to communicate with the cross chamber 2 and inflatable and deployable toward the occupant H.

[0025] The cross chamber 2 has, for example, a rotated ellipsoid (a shape obtained by rotating an ellipsoid around its major axis), but is not limited to such a shape. The cross chamber 2 is coupled to the outer surface of the webbing W. That is, the cross chamber 2 is located on the side of the webbing W opposite to the side that contacts the occupant H. Therefore, for example, as shown in Figure 2(A), the webbing W is positioned between the cross chamber 2 and the occupant H. The cross chamber 2 is coupled to the webbing W by, for example, sutures, but may be coupled by other means.

[0026] The crossing chamber 2 is configured to expand and unfold in a direction that forms an X shape with respect to the shoulder belt portion SB. The crossing angle is not limited to the angle shown in the figure, but is set according to conditions such as the vehicle type, the size of the crossing chamber 2, and the shape and size of the distribution chamber 3.

[0027] The distribution chamber 3 has, for example, a shape that is elongated in the vertical direction. Alternatively, the distribution chamber 3 may have a shape that is elongated in a direction parallel to the longitudinal direction of the shoulder belt portion SB. The distribution chamber 3 has, for example, a spheroid (a shape obtained by rotating an ellipse around its major axis) as shown in the figure, but is not limited to this shape. For example, it may be cylindrical, ellipsoidal, spherical, or ring-shaped.

[0028] The distribution chamber 3 includes a first distribution chamber 31 that inflates and deploys near the shoulder area of ​​the occupant H, and a second distribution chamber 32 that inflates and deploys near the lower part of the occupant H's chest. In the illustrated first embodiment, the first distribution chamber 31 is positioned to the right (right-hand side) of the center of the occupant H's chest, and the second distribution chamber 32 is positioned to the left (left-hand side) of the center of the occupant H's chest. Although not shown, depending on conditions such as the type of seat, the first distribution chamber 31 may be positioned to the left (left-hand side) of the occupant H, and the second distribution chamber 32 may be positioned to the right (right-hand side) of the occupant H.

[0029] Since the dispersion chamber 3 is the part that comes into contact with the occupant H, it is preferable to position it in a part that is stronger than the soft parts of the occupant H, such as the abdomen (a part where bone is present). In the first embodiment, the first dispersion chamber 31 expands and deploys near the clavicle or upper ribs of the occupant H (for example, in the range of the first to fifth ribs), and the second dispersion chamber 32 expands and deploys near the lower ribs of the occupant H (for example, in the range of the sixth to tenth ribs). The shape and size of the first dispersion chamber 31 and the second dispersion chamber 32 may be different.

[0030] Incidentally, with conventional seat belt systems, as shown in Figure 2(B), for example, the load (load Fw) on the occupant H's chest due to the webbing W during a vehicle collision is large. When a seat belt is worn, the webbing W is located in a position that passes through the center of the body. Since vital organs are contained in the center of the body, it is necessary to reduce the load on the occupant's chest (especially the center of the body).

[0031] As described above, the airbag 1 for the seat belt device according to this embodiment inflates and deploys the cross chamber 2 so that it extends to both sides of the shoulder belt portion SB, and inflates and deploys the distribution chamber 3 (first distribution chamber 31 and second distribution chamber 32) toward the occupant H. For example, as shown in Figure 2(A), the inflated and deployed distribution chamber 3 (first distribution chamber 31 and second distribution chamber 32) can come into contact with the occupant H, and the cross chamber 2 can be moved away from the occupant H. In other words, a bridge structure can be formed in front of the occupant H, with the distribution chamber 3 as the legs and the cross chamber 2 as the girder.

[0032] When the seat belt airbag 1 inflates and deploys, the cross chamber 2 inflates to the state shown by the dashed line in Figure 2(A), and therefore an inflationary force Fa acts in the direction that moves the cross chamber 2 away from the occupant H. Furthermore, when the seat belt airbag 1 inflates and deploys, a load acts on the webbing W in the direction that restrains the occupant H, so the cross chamber 2 bends toward the occupant H, as shown by the solid line in Figure 2(A).

[0033] According to the seat belt device airbag 1 of this embodiment, the inflation force Fa of the seat belt device airbag 1 can move the cross chamber 2 away from the occupant H, and the webbing W can also be moved away from the occupant H. As a result, by adopting the seat belt device airbag 1 of this embodiment, the load (load Fw) on the occupant H's chest (especially the central part of the body) due to the webbing W during a vehicle collision can be reduced.

[0034] Next, the base fabric configuration of the seat belt device airbag 1 according to the first embodiment will be explained with reference to Figures 3(A) to 3(C). Here, Figure 3 is an explanatory diagram showing the configuration of the seat belt device airbag shown in Figure 1, where (A) is a parts exploded view, (B) is a diagram showing the state in the process of sewing, and (C) is a diagram showing the completed state. For the sake of explanation, Figures 3(A) to 3(C) are shown as viewed from the occupant's side.

[0035] The cross chamber 2 is composed of, for example, a first panel 21 located on the occupant H side when inflated and deployed, and a second panel 22 located on the opposite side of occupant H when inflated and deployed, as shown in Figure 3(A). The first panel 21 and the second panel 22 have inflatable and deployable sections 21a and 22a that inflat and deploy to extend on both sides of the shoulder belt section SB, and gas supply sections 21b and 22b that supply expansion gas to the inflatable and deployable sections 21a and 22a.

[0036] For example, the expansion and unfolding sections 21a and 22a have an oval shape, and the gas supply sections 21b and 22b have a strip shape. The first panel 21 is made of a base fabric formed in a roughly T-shape by the expansion and unfolding sections 21a and the gas supply sections 21b. The second panel 22 has the same shape as the first panel 21.

[0037] Openings 23 are formed at both ends of the expansion and deployment section 21a of the first panel 21, forming communication sections that supply expansion gas to the dispersion chamber 3. Note that the base fabric configuration of the cross chamber 2 is merely an example and is not limited to the base fabric configuration shown in the figure.

[0038] The dispersion chamber 3 (first dispersion chamber 31 and second dispersion chamber 32) is composed of, for example, a first panel 3a located on the occupant H side during inflation and deployment, and a second panel 3b located on the opposite side of occupant H during inflation and deployment, as shown in Figure 3(A). The first panel 3a and the second panel 3b have, for example, an oval shape.

[0039] The second panel 3b has an opening 3c that forms a supply port for expansion gas. Note that the base fabric configuration of the dispersion chamber 3 is merely an example and is not limited to the base fabric configuration shown in the figure.

[0040] As shown in Figure 3(B), the second panel 3b of the dispersion chamber 3 is joined to the first panel 21 of the cross chamber 2 by aligning its opening 3c with the opening 23 of the first panel 21 of the cross chamber 2 and suturing the outer circumference of these openings 3c and 23. At this time, the orientation of the second panel 3b of the dispersion chamber 3 is adjusted and sutured so that it is positioned to stretch vertically when expanded and deployed.

[0041] Furthermore, the first panel 21 of the crossing chamber 2 is sutured to the webbing W approximately in the center, as shown in Figure 3(B). At this time, the webbing W is positioned and sutured so as to be on the same side as the second panel 3b of the distribution chamber 3. The webbing W is also sutured in such a way that it crosses the first panel 21 of the crossing chamber 2 to form an X shape. For the sake of clarity, the webbing W is shown as a dashed line in Figures 3(B) and 3(C).

[0042] As shown in Figure 3(C), the second panel 22 of the crossing chamber 2 is superimposed on the first panel 21 and its outer circumference is sutured. Similarly, as shown in Figure 3(C), the first panel 3a of the dispersion chamber 3 is superimposed on the second panel 3b and its outer circumference is sutured.

[0043] The method of suturing the crossing chamber 2 and the dispersion chamber 3 may be modified as appropriate depending on the shape of the crossing chamber 2 and the dispersion chamber 3, the base fabric configuration of the crossing chamber 2 and the dispersion chamber 3, and is not limited to the method shown in the illustration.

[0044] Furthermore, the method of joining the cross chamber 2 and the webbing W is not limited to suturing them together. Here, Figure 4 is a plan view showing modified methods of joining the cross chamber and the webbing, where (A) shows the first modified method and (B) shows the second modified method.

[0045] For example, as shown in Figure 4(A), both ends of a strip-shaped insertion member 24 may be sewn to the surface of the cross chamber 2 (specifically, the first panel 21), and the webbing W may be inserted through the portion of the insertion member 24 that is not sewn. The insertion member 24 is configured such that both ends on the longitudinal side of the cross chamber 2 are sewn to the first panel 21, while both ends on the longitudinal side of the webbing W are not sewn.

[0046] Alternatively, as shown in Figure 4(B), a patch panel 25 having a slit 25a through which the webbing W can be inserted may be sewn onto the surface of the cross chamber 2 (specifically, the first panel 21). For example, the patch panel 25 has a rectangle that is sewn to the first panel 21, and the slit 25a has a length greater than the width of the webbing W and is formed in two places to constitute the entrance and exit of the webbing W. By using the patch panel 25, the suturing area can be made larger than that of the insertion member 24, and the strength of the joint can be increased.

[0047] Next, the method for storing the seat belt device airbag 1 according to the first embodiment will be explained with reference to Figures 5(A) and 5(B). Here, Figure 5 is an explanatory diagram showing an example of a method for storing the seat belt device airbag, where (A) shows the folding lines and (B) shows the state before the folded seat belt device airbag is stored in the storage cover. In Figure 5(A), for the sake of explanation, the webbing W is shown as a dashed line.

[0048] The seat belt airbag 1, in which the crossing chamber 2 and the distribution chamber 3 are sewn together, is folded along the mountain fold lines (single-dot dashed line) and valley fold lines (double-dot dashed line) set in the longitudinal direction of the webbing W, as shown in Figure 5(A), and is folded into a shape along the webbing W, as shown in Figure 5(B).

[0049] The airbag 1 for the seat belt device is folded sequentially, for example, starting from the side of the cross chamber 2 closest to the gas supply section. At this time, the process of folding the first distribution chamber 31 side towards the second distribution chamber 32 side, and then folding the second distribution chamber 32 side of the folded body towards the first distribution chamber 31 side is repeated until it is folded to a state close to the width of the webbing W. Alternatively, the first distribution chamber 31 side may be folded to the width of the webbing W first, and then the second distribution chamber 32 side may be folded to the width of the webbing W.

[0050] The folding method of the seat belt device airbag 1 described above is merely one example and is not limited to the method shown in the illustration. For example, if the vertical length of the distribution chamber 3 is long, it may be folded in a direction perpendicular to the mountain fold line and valley fold line.

[0051] As shown in Figure 5(B), the seat belt device airbag 1, folded to a shape along the webbing W, is housed in a storage cover 4. The storage cover 4 has, for example, a cylindrical shape and is configured to rupture when the seat belt device airbag 1 inflates and deploys. Note that the configuration of the storage cover 4 is not limited to the illustrated configuration.

[0052] Next, the configuration of the airbag device 10 equipped with the seat belt device airbag 1 according to the first embodiment will be described with reference to Figures 6 to 7(B). Here, Figure 6 is an overall configuration diagram showing the airbag device equipped with the seat belt device airbag according to the first embodiment of the present invention. Figure 7 is an explanatory diagram showing the state of the seat belt device airbag in the airbag device shown in Figure 6 before inflation and deployment, where (A) is a front view and (B) is a side view.

[0053] The seat belt device shown in Figures 6 to 7(B) includes a webbing W that restrains the occupant H, a seat belt retractor 101 that winds up the webbing W, a buckle 102 positioned on the side of the seat S, a tongue 103 positioned on the webbing W, and a seat belt device airbag 1 positioned on the shoulder belt portion SB of the webbing W.

[0054] The seat belt device airbag 1 is assumed to be the seat belt device airbag 1 according to the first embodiment described above. The seat belt device airbag 1 is folded and stored in the storage cover 4 shown in Figure 5.

[0055] The seat belt retractor 101 is, for example, built into the seat S. A guide anchor 104 for guiding the webbing W is also positioned at the shoulder of the seat S. Although not shown in the diagram, the seat belt retractor 101 may also be built into the pillar of the vehicle body. In this case, the guide anchor is positioned on the pillar of the vehicle body. A seat belt retractor 101 that is generally available on the market can be used.

[0056] The buckle 102 is positioned on the side of the seat S opposite to the side where the guide anchor 104 is located. The buckle 102 has, for example, a slot for inserting a tongue 103 and a locking mechanism for locking the tip of the inserted tongue 103. The buckle 102 also has an inflator 105 that supplies inflation gas to the seat belt airbag 1. In this embodiment, the inflation gas is supplied from the inflator 105 to the cross chamber 2 of the seat belt airbag 1.

[0057] The tongue 103 has a gas supply port that communicates with the gas supply section of the seat belt airbag 1. When the tongue 103 is fitted onto the buckle 102, the gas supply port of the inflator 105 and the gas supply port of the tongue 103 are connected. Note that existing technology can be used for supplying inflation gas from the buckle 102 to the airbag located on the webbing W, so a detailed explanation is omitted here.

[0058] Although not shown in the figures, the inflator 105 that supplies inflation gas to the seat belt airbag 1 may be located on the side of the guide anchor 104. Existing technology can be used for supplying inflation gas to the airbag located on the webbing W from the shoulder of the seat S, so a detailed explanation is omitted here. In this case, the gas supply section of the cross chamber 2 of the seat belt airbag 1 is also located on the opposite side from that of the first embodiment described above.

[0059] As shown in Figures 7(A) and 7(B), when the tongue 103 is fitted onto the buckle 102, the webbing W that restrains the occupant's waist constitutes the lap belt section LB. The end of the lap belt section LB is connected to a lap belt retractor 106 that winds up the webbing W on the lap belt section LB side. Alternatively, the lap belt retractor 106 may be omitted, and the end of the lap belt section LB may be fixed to the seat S.

[0060] As shown in Figures 7(A) and 7(B), when an occupant H seated in seat S fastens the tongue 103 to the buckle 102, the shoulder belt portion SB restrains the occupant H's upper body, and the lap belt portion LB restrains the occupant H's waist. At this time, the seat belt retractor 101 and the lap belt retractor 106 may be used to remove any slack in the webbing W.

[0061] During a vehicle collision, inflation gas is supplied from the inflator 105 to the seat belt airbag 1, causing it to inflate and deploy as shown in Figures 1(A) and 1(B). Therefore, according to the airbag device 10 of the first embodiment, the inflated and deployed dispersion chamber 3 comes into contact with the occupant H, thereby moving the cross chamber 2 away from the occupant, and a force can be applied to the webbing W in a direction away from the occupant H, thereby reducing the load on the center of the body.

[0062] Next, an airbag for a seat belt system and an airbag system according to a second embodiment of the present invention will be described with reference to Figure 8. Here, Figure 8 is an explanatory diagram showing an airbag for a seat belt system according to a second embodiment of the present invention, where (A) is a front view and (B) is a side view. Note that the same reference numerals are used for components similar to those in the first embodiment described above, and detailed descriptions are omitted.

[0063] The seat belt airbag 1 shown in Figures 8(A) and 8(B) has a shape in which the first distribution chamber 31 and the second distribution chamber 32 are extended to a position near the head of the occupant H. In this way, the first distribution chamber 31 and the second distribution chamber 32 have a shape that is elongated in the vertical direction to the head of the occupant H, thereby protecting the head of the occupant H.

[0064] Furthermore, the dispersion chamber 3 may include a head protection membrane 33 connected to the tip of the first dispersion chamber 31 and the second dispersion chamber 32, which is stretched over the face of the occupant H. By positioning the head protection membrane 33 in this way, which is stretched over the face (front of the head) of the occupant H during a vehicle collision, the occupant H's head can be caught by the head protection membrane 33, and the amount of forward movement of the occupant H's head can be reduced.

[0065] The airbag device 10 according to the second embodiment shown in Figures 8(A) and 8(B) is configured to supply expansion gas from the inflator 105 to the first dispersion chamber 31 of the seat belt device airbag 1.

[0066] The first distribution chamber 31 has a vertically elongated shape extending from the occupant H's head to his waist, and its lower end is connected to the gas supply port of the tongue 103. In this way, the inflation gas for inflating and deploying the seat belt airbag 1 may be supplied from the distribution chamber 3 rather than from the crossing chamber 2.

[0067] Although not shown in the figures, in the airbag device 10 according to the second embodiment, the expansion gas may be supplied from the cross chamber 2, similar to the airbag device according to the first embodiment.

[0068] The airbag devices 10 according to the first and second embodiments described above are assumed to be applied to seats S located in the front seats of a vehicle, but the airbag devices 10 may also be applied to seats S located in the rear seats. Furthermore, the airbag devices 10 may also be applied to seat belt devices used in vehicles other than vehicles.

[0069] The present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0070] 1. Airbag for seat belt system 2 Cross Chamber 3 Dispersion Chamber 3a First Panel 3b Second Panel 3c opening 4 Storage cover 10. Airbag system 21 First Panel 21a, 22a Expanding and unfolding section 21b, 22b Gas supply section 22 Second Panel 23 Opening 24 Insertion member 25 Patch Panels 25a Slit 31 First Dispersion Chamber 32 Second Dispersion Chamber 33 Head protection membrane 101 Seatbelt Retractor 102 Buckle 103 Tongue 104 Guide Anchor 105 Inflator 106 Wrap Belt Retractor

Claims

1. An airbag for a seat belt system, which is positioned in a seat belt system that restrains a seated occupant to a seat using webbing including a shoulder belt portion that extends from the occupant's shoulder to their waist, A cross chamber is provided on the shoulder belt portion and is expandable and deployable toward both sides in a direction intersecting the longitudinal direction of the shoulder belt portion, Dispersive chambers are provided at both ends of the crossing chamber, which are connected to the crossing chamber and are capable of expanding and unfolding toward the occupants, An airbag for a seat belt system, characterized by including the following:

2. The airbag for a seat belt device according to claim 1, wherein the crossing chamber is bonded to the outer surface of the webbing.

3. The airbag for a seat belt device according to claim 1, wherein the dispersion chamber includes a first dispersion chamber that inflates and deploys near the occupant's shoulder and a second dispersion chamber that inflates and deploys near the lower part of the occupant's chest.

4. The airbag for a seat belt device according to claim 1, wherein the dispersion chamber has a shape that is elongated in the vertical direction.

5. The airbag for a seat belt device according to claim 1, wherein the distribution chamber includes a first distribution chamber positioned on either the left or right side of the center of the occupant's chest, and a second distribution chamber positioned on the other side of the left or right side of the center of the occupant's chest.

6. The airbag for a seat belt device according to claim 5, wherein the first and second distribution chambers have a vertically elongated shape extending to a position near the occupant's head.

7. The airbag for a seat belt device according to claim 6, wherein the dispersion chamber comprises a head protection membrane connected to the tip of the first dispersion chamber and the second dispersion chamber and stretched over the face of the occupant.

8. An airbag device characterized by comprising an airbag for a seat belt device as described in any one of claims 1 to 7.

9. The airbag device according to claim 8, further comprising an inflator that supplies expansion gas to the cross chamber or the dispersion chamber.

10. The airbag device according to claim 8, further comprising a storage cover for storing the seat belt device airbag folded in a shape along the webbing.

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