Curtain airbag system

Abstract

There was a need for technology that could prevent occupants from being ejected from the vehicle during a rollover while suppressing the need to increase the size of curtain airbags. [Solution] A curtain airbag device attached to the roof side rail portion of the upper part of a vehicle, comprising: a bag body that inflates when inflating gas is supplied and extends downward along the side wall of the vehicle to cover the window portion in the side wall, down to the bottom of the window portion; and a tether which is a strip-shaped member, the ends of which are fixed to the front and rear of the window portion of the vehicle, and the part of the tether other than the ends which is fixed to the lower part of the bag, which is part of the bag body including the lower end of the bag body, wherein the bag body comprises an inflatable portion to which inflating gas is supplied and a non-inflatable portion to which inflating gas is not supplied, and in the state in which the bag body is deployed, the lower end of the inflatable portion does not cover the lower edge of the window portion.

Description

Technical Field

[0006] , ,

[0005] , , , ,

[0001] The present disclosure relates to a curtain airbag device.

Background Art

[0002] In a curtain airbag disposed on a side wall of a vehicle, the lower end portion of the curtain airbag is usually located at the lower edge of a window portion on the side wall of the vehicle. In the curtain airbag of Patent Document 1, this lower end portion is extended so as to cover a door trim. Accordingly, the curtain airbag of Patent Document 1 covers a window portion of the side wall of the vehicle and a part of the door trim. Therefore, the curtain airbag of Patent Document 1 can prevent an occupant from being ejected outside the vehicle during a rollover of the vehicle.

[0003] Note that, before being deployed, the curtain airbag of Patent Document 1 is stored in a folded state in a roof side rail portion of the vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0007] This disclosure can be implemented in the following forms:

[0008] (1) According to one embodiment of the present disclosure, a curtain airbag device is provided which is attached to the roof side rail portion of the upper part of a vehicle. The curtain airbag device comprises a bag body which inflates by being supplied with inflation gas and extends downward along the side wall of the vehicle to the lower part of the window portion so as to cover the window portion in the side wall; and a tether which is a strip-shaped member, the ends of which are fixed to the front and rear of the window portion of the vehicle, and the part of which other than the ends is fixed to the lower part of the bag which is part of the bag body including the lower end of the bag body, wherein the bag body comprises an inflatable portion to which the inflation gas is supplied and a non-inflatable portion to which the inflation gas is not supplied, and in the deployed state of the bag body, the lower end of the inflatable portion does not cover the lower edge of the window portion. In this embodiment, the bag body is deployed to cover the window. Furthermore, the tether, which is a strip-shaped member, is configured such that both ends are fixed to the front and rear of the vehicle's window, and the portion other than the ends is fixed to the bottom of the bag. In other words, the curtain airbag system suppresses deformation of the bag body in the lateral direction of the vehicle compared to an embodiment without a tether. More specifically, when the bag body is subjected to a force from the inside to the outside of the vehicle, the curtain airbag system can suppress deformation of the bag body toward the outside of the vehicle. Furthermore, the bag body does not cover the lower edge of the window. Therefore, the curtain airbag system can suppress an increase in the size of the bag body compared to an embodiment in which the lower end of the bag body is extended. (2) In the curtain airbag device of the above form, the tether may be fixed to the non-inflatable portion. In this embodiment, the tether is configured to be fixed to a non-inflatable portion of the bag body that is less prone to deformation than the inflatable portion. In other words, the curtain airbag device is designed to be easier to fix to the bag body compared to the configuration in which the tether is fixed to the inflatable portion of the bag body. (3) In the curtain airbag device of the above form, the tether may be located on the exterior side of the bag body opposite to the interior side facing the vehicle when the bag body is deployed. This configuration makes it easier to prevent the curtain airbag from deforming outwards. More specifically, when an object collides with the side of the bag inside the vehicle, the tether supports the bag from the side outside the vehicle. In other words, when the bag is subjected to a force from the inside outwards of the vehicle, it becomes less likely to fly outwards. Therefore, compared to a configuration where the tether is fixed to the side of the bag inside the vehicle, the curtain airbag system makes it easier to keep the bag inside the vehicle. (4) In the curtain airbag device of the above form, the tether may be configured to be fixed within a range of one-third of the bag height from the lower end of the inflatable portion. This configuration allows the tether to more effectively suppress the movement of the lower end of the inflatable section than if it were fixed at a position higher than one-third of the bag height. Therefore, the curtain airbag system can minimize the gap between the window and the bag body. (5) In the curtain airbag device of the above form, both ends are configured to be fixed to the front and rear of the roof side rail portion, and the length of the tether may be longer than the length of the roof side rail portion and shorter than the shortest length connecting both ends of the tether along the surface of the bag body in the fully inflated state in a curtain airbag device of the form without the tether. By adopting this configuration, the curtain airbag system can suppress deformation of the bag body and movement of the lower end of the inflatable section, which would otherwise cause the tether to extend longer than the shortest length connecting both ends. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram showing a curtain airbag system in a vehicle. [Figure 2] This is an explanatory diagram showing the tether located on the exterior side of the bag body. [Figure 3] This is an explanatory diagram showing a cross-section of the bag body in its unfolded state. [Figure 4] Figure 3 is an explanatory diagram showing the state when the head impactor collides with the bag body. [Figure 5] This is an explanatory diagram showing the tethers located on the exterior and interior sides of the bag body. [Modes for carrying out the invention]

[0010] A. First Embodiment: A-1. Device Configuration: Figure 1 is an explanatory diagram showing a curtain airbag system 10 in vehicle V. The curtain airbag system 10 is installed in vehicle V. The curtain airbag system 10 activates when vehicle V is involved in a collision or rollover, protecting the protected person PO. More specifically, the curtain airbag system 10 prevents the protected person PO from colliding with the window Wd of vehicle V. Furthermore, the curtain airbag system 10 reduces the risk of the protected person PO being ejected from the vehicle through the window Wd. The curtain airbag system 10 is designed to comply with FMVSS (Federal Motor Vehicle Safety Standards) standards. In particular, the curtain airbag system 10 is designed to meet FMVSS 226, which is a standard for reducing the ejection of the protected person PO from outside the vehicle.

[0011] In this specification, the forward direction FD indicates the front of the vehicle V in the direction of travel. The rearward direction BD indicates the rear of the vehicle V in the direction of travel. The upward direction UD indicates the upper part of the vehicle V in the height direction. The downward direction DD indicates the lower part of the vehicle V in the height direction. In this specification, the side of the upward direction UD is treated as "up," and the side of the downward direction DD is treated as "down." Furthermore, the direction along the forward direction FD and the rearward direction BD is called the longitudinal direction. The direction along the upward direction UD and the downward direction DD is called the vertical direction. The direction perpendicular to the longitudinal direction and the vertical direction is called the left-right direction. In Figure 1, the side wall Ws of the vehicle V in the rightward direction RD is shown. Hereafter, these directions are also used to indicate parts of each component of the curtain airbag device 10.

[0012] Figure 1 illustrates the state in which the bag body 100 of the curtain airbag device 10 is deployed along the side wall Ws. In Figure 1, the protected area PO represents the occupants of the first row and the occupants of the second row of vehicle V. Furthermore, the circular part of the protected area PO represents the occupants' heads. In Figure 1, the roof side rail portion Rr and the center pillar Pc are shown in large detail relative to the curtain airbag device 10 to facilitate understanding of the technology.

[0013] The curtain airbag system 10 comprises a bag body 100 (see middle section of Figure 1), a tether 200 (see lower section of Figure 1), and an inflator 300 (see middle section center of Figure 1). Furthermore, the curtain airbag system 10 is attached to the roof side rail portion Rr at the top of the vehicle V. More specifically, before the curtain airbag system 10 is activated, the bag body 100, tether 200, and inflator 300 are stored in the roof side rail portion Rr. After the curtain airbag system 10 is activated, the bag body 100 and tether 200 are deployed from the roof side rail portion Rr.

[0014] Note that the bag body 100 is stored in a folded state together with the tether 200. Further, a part of the bag body 100 and the tether 200 is fixed to the roof side rail portion Rr. More specifically, the upper end 100u of the bag body 100 and both end portions 210 of the tether 200 are fixed to the roof side rail portion Rr. In FIG. 1, for ease of understanding of the technology, the tether 200 is shown linearly. However, as will be described later, since the tether 200 is arranged along the outer side surface 110sb of the vehicle body outside the vehicle compartment, it is configured to be longer than the length of the roof side rail portion Rr. The operation of the curtain airbag device 10 will be described in detail later.

[0015] The roof side rail portion Rr is located at both left and right ends in the lateral direction at the upper part of the vehicle V. That is, the roof side rail portion Rr is a part of the frame of the vehicle V that extends in the front-rear direction along the ceiling portion of the vehicle V. More specifically, the roof side rail portion Rr includes the front pillar Rrf and the rear pillar Rrr, and connects the respective pillars via the upper ends of the side walls Ws. Note that the window portion Wd is located between the front pillar Rrf and the rear pillar Rrr in the front-rear direction, and is located downward DD from the upper ends of the side walls Ws. Further, the lower edge portion Wdd of the window portion Wd overlaps the upper end portion Dtu of the door trim Dt.

[0016] The inflator 300 injects inflation gas into the bag body 100. The inflator 300 is located at the opening at the upper part of the curtain airbag device 10 in FIG. 1. The inflator 300 operates to inject inflation gas in response to detection or prediction of a collision by a control unit (not shown) mounted on the vehicle V. Thereby, the inflator 300 inflates the bag body 100.

[0017] The airbag body 100 expands when inflation gas is supplied. Further, when the airbag body 100 expands, it expands downward DD of the vehicle V along the side wall Ws of the vehicle V so as to cover the window portion Wd in the side wall Ws and develop to the lower part of the window portion Wd. Note that "covering the window portion Wd" does not mean completely covering and hiding the entire window portion Wd, but means forming a range capable of protecting the protection target PO from the upper part to the lower part of the window portion Wd. Specifically, after the airbag body 100 is deployed, the lower end portion 110d of the airbag body 100 is arranged so as to be close to the upper end portion Dtu of the door trim Dt along the extending direction of the upper end portion Dtu of the door trim Dt. Note that the lower end portion 110d of the airbag body 100 is also the lower end 110d of the inflatable portion described later.

[0018] The airbag body 100 forms a substantially rectangular bag body in a state where the airbag body 100 is deployed. The airbag body 100 is manufactured by the OPW (One Piece Woven) method. That is, the airbag body 100 is configured as an integrated bag body woven into a bag by an automatic loom. However, the airbag body 100 may be formed by a method different from the OPW method. For example, the airbag body 100 may be configured by overlapping and sewing a plurality of cloths.

[0019] In this manufacturing, the airbag body 100 is cut out from a base fabric of a fixed size during manufacturing. Since the airbag body 100 of the present embodiment has a structure in which the lower end portion 110d does not extend downward DD, the shape of the base fabric at the time of cutting becomes close to a quadrangle. By adopting such an aspect, the curtain airbag device 10 of the present embodiment minimizes the end material of the base fabric. That is, the curtain airbag device 10 of the present embodiment can improve the material yield as compared with an aspect having an airbag body 100 having a structure in which the lower end portion 110d extends downward DD.

[0020] Note that the base fabric is, for example, made of polyethylene terephthalate and is coated with a resin. The thickness of the base fabric is, for example, about 0.7 mm.

[0021] The bag body 100 comprises an inflation section 110 to which inflation gas is supplied and a non-inflation section 120 to which inflation gas is not supplied. The inflation section 110 is the part of the bag to which inflation gas is supplied, excluding the upper opening of the curtain airbag device 10 into which the inflator 300 is inserted.

[0022] The non-expanding section 120 controls the flow of the expansion gas supplied to the expansion section 110. The non-expanding section 120 is formed by partially joining two pieces of fabric that make up the bag body 100 by sewing. In Figure 1, the non-expanding section 120 is the hatched portion of the bag body 100. That is, the non-expanding section 120 includes a portion along the outer circumference of the bag body 100, a portion extending inward from the bag body 100, and a portion formed in an island shape within the bag body 100. A tether 200, which will be described later, is attached to a part of the non-expanding section 120.

[0023] Furthermore, when the bag body 100 is unfolded, the lower end 110d of the inflatable portion 110 is positioned in the direction in which the upper end Dtu of the door trim Dt extends, and is close to the upper end Dtu of the door trim Dt. Therefore, the lower end 110d of the inflatable portion 110 is configured not to cover the lower edge Wdd of the window portion Wd.

[0024] The tether 200 prevents deformation of the bag body 100 and movement of the lower end 110d of the inflatable part.

[0025] The tether 200 is a strip-shaped member that is more rigid than the bag body 100. For example, the tether 200 is constructed by laminating the same material as the bag body 100. In other words, the tether 200 is constructed to be more rigid than the bag body 100 by adjusting its shape. For example, the tether 200 has a rectangular cross-section, with a width of approximately 20 mm and a thickness of approximately 3 mm. This configuration is achieved by laminating multiple base fabrics.

[0026] However, the tether 200 only needs to be constructed to have greater rigidity than the bag body 100. For this reason, its width can be as low as 10-30 mm, and its thickness can be as low as 2-5 mm by laminating two or more base fabrics. Furthermore, the cross-section of the tether 200 is not limited to a rectangle; it can also be circular. Moreover, the tether 200 may be constructed from a different material than the base fabric of the bag body 100. However, such a tether 200 can be realized by means of using a material with a high elastic modulus, adjusting its shape, etc.

[0027] The tether 200 is fixed at both ends 210 to the front and rear of the vehicle V. That is, both ends 210 are configured to be fixed to the front and rear of the roof side rail portion Rr. More specifically, of the two ends 210, one end 210 is fixed near the end of the downward DD on the front pillar Rrf, and the other end 210 is fixed near the end of the downward DD on the rear pillar Rrr.

[0028] Furthermore, as shown by the joint Pj in Figure 1, a portion of the tether 200 other than both ends 210 is fixed to the non-expanding portion 120 of the bag body 100. For example, as shown in Figure 1, this portion is fixed to the non-expanding portion 120 extending inward from the bag body 100 (see the middle section), the non-expanding portion 120 formed in an island shape within the bag body 100 (see the left section), and the non-expanding portion 120 along the outer circumference of the bag body 100 (see the leftmost section). The tether 200 is attached and fixed to the non-expanding portion by sewing. However, the tether 200 may also be fixed to the non-expanding portion 120 by welding, adhesive with tape, or by tying with a ring-shaped component. In this embodiment, the tether 200 is configured to be fixed to the non-expanding portion 120, which is less prone to deformation than the expandable portion 110 of the bag body 100. In other words, the curtain airbag device 10 of this embodiment is designed to be easier to attach to the bag body 100 compared to the configuration in which the tether 200 is attached to the inflatable portion 110 of the bag body 100.

[0029] Furthermore, a portion of the tether 200, excluding both ends 210, is configured to be fixed to the lower part of the bag 100, which is part of the bag body 100, including the lower end 110d of the bag body 100. The lower part of the bag 110b is the portion located below DD from a position half H / 2 of the bag height H. The bag height H is the length from the upper end 110u of the inflatable part 110 to the lower end 110d of the inflatable part 110.

[0030] The tether 200 is configured to be longer than the length of the roof side rail section Rr. More specifically, the length of the tether 200 is longer than the length from the end of the downward DD at the front pillar Rrf, along the direction in which the roof side rail section Rr extends, to the end of the downward DD at the rear pillar Rrr. Furthermore, the roof side rail section Rr is longer than the straight-line distance connecting both ends 210 of the tether 200.

[0031] Furthermore, the length of the tether 200 is shorter than the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state in a curtain airbag device without the tether 200. Note that the "curtain airbag device without the tether 200" is identical to the curtain airbag device 10 of this embodiment except for the tether 200. By adopting this configuration, the curtain airbag device 10 of this disclosure can suppress deformation of the bag body 100 and movement of the lower end 110d of the inflated portion, which would cause the tether 200 to extend longer than the shortest length connecting both ends 210 of the tether 200.

[0032] Figure 2 is an explanatory diagram showing the tether 200 located on the exterior side 110sb of the bag body 100. In Figure 2, an explanatory diagram is shown showing the position of the tether 200 in a cross-section of the bag body 100 when viewed along the downward direction DD. However, for ease of understanding the technology, the positions of the inflatable portion 110 and the non-inflatable portion 120 are shown at equal intervals, unlike the positions in Figure 1. When the bag body 100 is deployed, the tether 200 is located on the exterior side 110sb of the bag body 100, opposite to the interior side 110sf of the bag body 100 that faces the inside of the vehicle V. More specifically, when viewing the bag body 100 and the tether 200 from the inside to the outside of the vehicle V along a direction parallel to the left-right direction, the tether 200 is located outside the interior side 110sf of the bag body 100. With this configuration, the curtain airbag device 10 of this embodiment is more likely to suppress the deformation of the bag body 100 outward of the vehicle V. More specifically, when the object to be protected PO collides with the interior side 110sf of the bag body 100, the tether 200 supports the bag body 100 from the exterior side 110sb of the bag body 100. In other words, when the bag body 100 is subjected to a force directed from the inside to the outside of the vehicle V, it becomes less likely to fly out of the vehicle V. Therefore, the curtain airbag device 10 of this embodiment makes it easier to keep the bag body 100 inside the vehicle V compared to an embodiment where the tether 200 is fixed to the interior side 110sf of the bag body 100.

[0033] A-2. Operation of the curtain airbag system 10: The curtain airbag system 10 activates when the vehicle V is involved in a collision or rollover. Specifically, the curtain airbag system 10 uses an inflator 300 to inject inflation gas into the bag body 100. This causes the bag body 100, which is stored in the roof side rail section Rr, to inflate. At the same time, the tether 200, which was stored together with the bag body 100, is also stretched.

[0034] When unfolded, the bag body 100 extends down to the bottom of the window portion Wd on the side wall Ws so as to cover the window portion Wd. However, the lower end 110d of the inflatable portion does not cover the lower edge Wdd of the window portion Wd. In other words, since the inflatable portion 110 does not overlap with the door trim Dt, the bag body 100 unfolds along the window portion Wd.

[0035] When the bag body 100 is deployed, the tether 200 is positioned across the window section Wd from the front pillar Rrf to the rear pillar Rrr. A portion of the tether 200, excluding both ends 210, is fixed to the lower part 110b of the bag, thereby holding the lower part 110b. As a result, the bag body 100 is held in a position along the window section Wd because its upper end 100u is fixed to the roof side rail section Rr. This suppresses deformation of the bag body 100 and movement of the lower end 110d of the inflated section. More specifically, when the protected object PO collides with the bag body 100, the tether 200 functions to generate a reaction force against the force that would cause the bag body 100 to deform, thereby suppressing deformation. This reduces the risk of the protected object PO being ejected from the vehicle. Furthermore, the tether 200 holds the bag body 100, preventing the bag body 100 from separating from the window Wd due to the swinging motion that occurs when the protected object PO collides with the bag body 100. This reduces the risk of the protected object PO being ejected outside the vehicle through the gap between the bag body 100 and the upper end Dtu of the door trim Dt.

[0036] Figure 3 is an explanatory diagram showing a cross-section of the bag body 100 in its unfolded state. Figure 3 illustrates the cross-section of the bag body 100 as viewed along the rear direction BD. This figure represents the state immediately before the head impactor Im collides with the bag body 100. The head impactor Im in Figure 3 is the one used in the FMVSS 226 test. This standard requires that the amount by which the bag body 100 protrudes from the window Wd due to impact by the head impactor Im be kept to less than 100 mm.

[0037] Figure 4 is an explanatory diagram showing the state when the head impactor Im collides with the bag body 100 shown in Figure 3. The tether 200 is located on the outer side 110sb of the bag body 100. This allows the tether 200 to effectively suppress deformation of the bag body 100 when the bag body 100 is subjected to a force directed outward from the vehicle V due to the collision with the head impactor Im. Furthermore, the tether 200 is located on the lower part 110b of the bag. That is, the tether 200 is likely to be located downward DD from the head impactor Im. This allows the tether 200 to effectively support the lower end 110d of the bag body 100 and prevent it from moving outward from the window, even when the bag body 100 is subjected to a force directed outward from the vehicle V due to the collision with the head impactor Im. As a result, the amount of protrusion of the bag body 100 from the window Wd is kept to less than 100 mm.

[0038] As described above, the curtain airbag device 10 of this embodiment can protect the object to be protected PO even in an embodiment in which the lower end portion 110d of the bag body 100 is not extended downward DD.

[0039] In this embodiment, the bag body 100 is deployed to cover the window portion Wd. Furthermore, the tether 200, which is a strip-shaped member, is configured such that both ends 210 are fixed to the front and rear of the window portion Wd of the vehicle V, and a portion other than the ends 210 is fixed to the lower part 110b of the bag. That is, the curtain airbag device 10 of this embodiment suppresses deformation of the bag body 100 in the left-right direction of the vehicle V compared to an embodiment without the tether 200. More specifically, the curtain airbag device 10 of this embodiment can suppress deformation of the bag body 100 toward the outside of the vehicle V when the bag body 100 is subjected to a force from the inside to the outside of the vehicle V. Furthermore, the bag body 100 does not cover the lower edge portion Wdd of the window portion Wd. Therefore, the curtain airbag device 10 of this embodiment can suppress an increase in the size of the bag body 100 compared to an embodiment in which the lower end portion 110d of the bag body 100 is extended.

[0040] By suppressing the increase in the size of the bag body 100, the curtain airbag device 10 of this embodiment can reduce the cost of the bag body 100. Furthermore, since the amount of inflation gas required to inflate the bag body 100 is also reduced, the curtain airbag device 10 of this embodiment can reduce the gas capacity of the inflator 300. In other words, the curtain airbag device 10 of this embodiment can also reduce the cost required for the inflator 300. Moreover, since the lower end portion 110d of the bag body 100 is not extended downward DD, the shape of the base fabric when cut becomes closer to a rectangle. Therefore, the curtain airbag device 10 of this embodiment minimizes the amount of base fabric scraps. In other words, the curtain airbag device 10 of this embodiment can improve the material yield compared to an embodiment having a bag body 100 in which the lower end portion 110d is extended downward DD.

[0041] In this embodiment, the tether 200 is fixed to the non-inflatable portion 120. In this embodiment, the tether 200 is configured to be fixed to the non-inflatable portion 120, which is less prone to deformation than the inflatable portion 110 of the bag body 100. In other words, the curtain airbag device 10 of this embodiment is designed to be easier to fix to the bag body 100 compared to the embodiment in which the tether 200 is fixed to the inflatable portion 110 of the bag body 100.

[0042] Furthermore, when the bag body 100 is deployed, the tether 200 is positioned on the exterior side 110sb of the bag body 100, opposite to the interior side 110sf that faces the inside of the vehicle V. This configuration makes it easier to prevent the bag body 100 from deforming outwards from the vehicle V. More specifically, when the object to be protected PO collides with the interior side 110sf of the bag body 100, the tether 200 supports the bag body 100 from the exterior side 110sb. In other words, when the bag body 100 is subjected to a force directed from the inside to the outside of the vehicle V, it becomes less likely to fly outwards from the vehicle V. Therefore, the curtain airbag device 10 of this embodiment makes it easier to keep the bag body 100 inside the vehicle V compared to a configuration in which the tether 200 is fixed to the interior side 110sf of the bag body 100.

[0043] Furthermore, the tether 200 is configured such that both ends 210 are fixed to the front and rear of the roof side rail portion Rr. In addition, the length of the tether 200 is longer than the length of the roof side rail portion Rr, and shorter than the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state in a curtain airbag device 10 without the tether 200. By adopting this configuration, the curtain airbag device 10 of this embodiment can suppress deformation of the bag body 100 and movement of the lower end 110d of the inflated portion, which would cause the tether 200 to extend longer than the shortest length connecting both ends 210.

[0044] B. Second Embodiment: Figure 5 is an explanatory diagram showing the tether 200 located on the exterior side 110sb and interior side 110sf of the bag body 100. In the above embodiment, the tether 200 is located on the exterior side 110sb of the bag body 100 when the bag body 100 is unfolded. However, the tether 200 may be located on both the interior side 110sf and the exterior side 110sb of the bag body 100. This arrangement is achieved by passing the non-inflatable portion 120 through which the tether 200 is positioned along a portion of the interior side 110sf and a portion of the exterior side 110sb.

[0045] This configuration makes it easier for both sides of the bag body 100 to expand evenly, thus suppressing uneven expansion. As a result, sagging of the tether 200 is suppressed when the bag body 100 expands. More specifically, if the tether 200 is located on only one side of the bag body 100, the side of the bag body 100 that includes the side without the tether 200 will expand more easily. On the other hand, the side of the bag body 100 that includes the side with the tether 200 will expand less easily. As a result, the tension acting on the tether 200 becomes smaller, making the tether 200 more prone to sagging. However, by positioning the tether 200 on both the interior side 110sf and the exterior side 110sb of the vehicle, both sides of the bag body 100 will expand more evenly, thus suppressing sagging of the tether 200. Therefore, the curtain airbag device 10 of this embodiment can hold the bag body 100 more strongly than the embodiment in which the tether 200 is located only on the exterior surface 110sb of the vehicle interior. In other words, the curtain airbag device 10 of this embodiment may be able to more effectively suppress deformation of the bag body 100 and movement of the lower end 110d of the inflatable part.

[0046] C. Other embodiments: In the above embodiment, the tether 200 may be configured to be fixed within a range of one-third of the bag height H from the lower end 110d of the inflatable portion of the lower part 110b of the bag. By adopting this configuration, the tether 200 can more effectively suppress the movement of the lower end 110d of the inflatable portion than if it were fixed at a position higher than one-third of the bag height H. Therefore, the curtain airbag device 10 of this embodiment can reduce the gap between the window portion Wd and the bag body 100.

[0047] Furthermore, in the above embodiment, the length of the tether 200 is shorter than the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state in a curtain airbag device 10 without a tether 200. In this embodiment, it is desirable that this "surface in the maximum inflated state" includes the central part of the main chamber MC of the bag body 100, as shown in Figure 1. The main chamber MC is a part of the inflatable section 110, which is mainly provided to protect the occupant's head. The main chamber MC is connected to another inflatable section 110 called the sub-chamber SC. In addition to protecting the occupant, the sub-chamber SC adjusts the internal pressure of the main chamber MC by being connected to it. Typically, the main chamber MC is designed to inflate more than the sub-chamber SC. The central part of the main chamber MC is the most inflated part of the main chamber MC and is located at approximately half the bag height H / 2.

[0048] In other words, the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state, including the center of the main chamber MC, is longer than the shortest length connecting both ends of the tether 200 along the surface in its maximum inflated state within one-third of the bag height H. Therefore, in this embodiment, by designing the length of the tether 200 to be shorter than the shortest length connecting both ends of the tether 200 along the surface in its maximum inflated state, including the center of the main chamber MC, the tether 200 can more reliably suppress deformation of the bag body 100 and movement of the lower end 110d of the inflated portion.

[0049] D. Other embodiments: (D1) In the above embodiment, one end 210 of the tether 200 is fixed near the end of the downward DD on the front pillar Rrf, and the other end is fixed near the end of the downward DD on the rear pillar Rrr. However, it is sufficient for both ends 210 of the tether 200 to be fixed to the front and rear of the window portion Wd of the vehicle V. For example, both ends 210 of the tether 200 may be fixed to the central portions of the front pillar Rrf and the rear pillar Rrr, respectively.

[0050] (D2) In the above embodiment, the tether 200 is fixed to the non-expanding portion 120 with respect to both ends 210. However, the tether 200 may also be fixed to the expanding portion 110 with respect to both ends 210.

[0051] (D3) In the above embodiment, the length of the tether 200 is longer than the length of the roof side rail portion Rr, and shorter than the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state in a curtain airbag device 10 without the tether 200. However, the length of the tether 200 may be shorter than the length of the roof side rail portion Rr. For example, the length of the tether 200 may be the length from the central part of the front pillar Rrf to the central part of the rear pillar Rrr. Furthermore, the length of the tether 200 may be longer than the shortest length connecting both ends of the tether 200 along the surface of the bag body 100 in its maximum inflated state in a curtain airbag device 10 without the tether 200. In such an embodiment as well, since the tether 200 has greater rigidity than the bag body 100, there is a high possibility that it can suppress movement and deformation of the bag body 100.

[0052] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the Summary of the Disclosure section can be replaced or combined as appropriate to solve some or all of the above problems, or to achieve some or all of the above effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]

[0053] 10…Curtain airbag device, 100…Bag body, 100u…Upper end, 110…Inflatable section, 110b…Lower part of bag, 110d…Lower end of inflatable section, 110sb…Exterior side of passenger compartment, 110sf…Interior side of passenger compartment, 110u…Upper end of inflatable section, 120…Non-inflatable section, 200…Tether, 210…Both ends, 300…Inflator, Dt…Door trim, Dtu…Upper end, Im…Head impactor, PO…Protected object, Pc…Center pillar, Rr…Roof side rail section, Rrf…Front pillar, Rrr…Rear pillar, V…Vehicle, Wd…Window section, Wdd…Lower edge, Ws…Side wall, Pj…Joint, MC…Main compartment, SC…Secondary compartment

Claims

1. A curtain airbag system that is attached to the roof side rail portion at the top of the vehicle, A bag body that expands when an expansion gas is supplied and extends along the side wall of the vehicle downwards, covering the window portion in the side wall, up to the bottom of the window portion, A tether which is a strip-shaped member, wherein both ends are fixed to the front and rear of the window portion of the vehicle, and the portion other than the ends is fixed to the lower part of the bag which is part of the bag body including the lower end of the bag body, The bag body is, It comprises an expansion section to which the expansion gas is supplied, and a non-expansion section to which the expansion gas is not supplied, A curtain airbag device in which, when the bag body is deployed, the lower end of the inflatable portion does not cover the lower edge of the window portion.

2. A curtain airbag device according to claim 1, The tether is fixed to the non-inflatable portion of the curtain airbag device.

3. A curtain airbag device according to claim 2, The tether is a curtain airbag device located on the exterior side of the bag body opposite to the interior side facing the vehicle, when the bag body is deployed.

4. A curtain airbag device according to claim 3, The curtain airbag device is configured such that the tether is fixed within a range of one-third of the bag height from the lower end of the inflatable section.

5. A curtain airbag device according to claim 4, The aforementioned ends are configured to be fixed to the front and rear of the roof side rail portion. A curtain airbag device wherein the length of the tether is longer than the length of the roof side rail portion, and shorter than the shortest length connecting both ends of the tether along the surface of the bag body in its maximum inflated state in a curtain airbag device without the tether.

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