Vehicle curtain airbag device

Abstract

To provide a curtain airbag device for a vehicle, capable of inhibiting a sub chamber in the process of inflation and deployment from getting on the upper face of a door trim.SOLUTION: A curtain airbag device 40 for a vehicle includes: a curtain airbag 50 having a sub chamber 52 which, by the supply of gas through a main chamber 54 for protecting the head PfH of an occupant Pf at least in the event of rollover of a vehicle 10, is inflated and deployed to a vehicle front side relative to the main chamber 54; and a temporarily sewn part 80 which is provided in the lower end part of the sub chamber 52, and which is not broken at the initial stage of inflation and deployment, but is broken by the time of completion of the inflation and deployment.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] A curtain airbag device that receives gas supply through a main chamber that restrains the head of an occupant during a rollover of a vehicle and has a sub-chamber that expands and deploys on the front side of the vehicle and below the vehicle side of the door belt line has been conventionally known (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, due to recent design trends, the upper surface of the door trim has become wider, and there is an increasing possibility that the sub-chamber during inflation deployment rides on the upper surface of the door trim. When the sub-chamber rides on the upper surface of the door trim, the curtain airbag moves outward in the vehicle width direction (away from the head of the occupant), and the restraint performance for the head of the occupant deteriorates.

[0005] Therefore, an object of the present invention is to obtain a vehicle curtain airbag device that can suppress the sub-chamber during inflation deployment from riding on the upper surface of the door trim.

Means for Solving the Problems

[0006] To achieve the above object, according to the present invention The 1 aspect The vehicle curtain airbag device has a curtain airbag having a sub-chamber that expands and deploys to the front side of the vehicle relative to the main chamber, through which gas is supplied at least during a vehicle rollover to protect the head of an occupant, and a temporary sewing portion provided at the lower end of the sub-chamber that does not tear during the initial stage of inflation and deployment and tears at the end of inflation and deployment.

[0007] The 1 aspect According to the invention of 1, a temporary sewing portion that does not tear during the initial stage of inflation and deployment and tears at the end of inflation and deployment is provided at the lower end of the sub-chamber that expands and deploys to the front side of the vehicle relative to the main chamber. Therefore, during the initial stage of inflation and deployment, it is difficult for gas to flow into the lower side of the vehicle relative to the temporary sewing portion, and a part of the sub-chamber on the lower side of the vehicle relative to the temporary sewing portion unfolds to the lower side of the vehicle while its thickness remains thinner than the thickness of the sub-chamber on the upper side of the vehicle relative to the temporary sewing portion. As a result, it is possible to suppress the lower end portion of the sub-chamber during inflation and deployment from riding up on the upper surface of the door trim.

[0008] Also, The 2 aspect The vehicle curtain airbag device of The 1 aspect The vehicle curtain airbag device of 1, wherein the temporary sewing portion is formed along the vertical direction or the longitudinal direction of the vehicle.

[0009] The 2 aspect According to the invention of 2, the temporary sewing portion is formed along the vertical direction or the longitudinal direction of the vehicle. Therefore, during the initial stage of inflation and deployment, the inflow of gas to the lower side of the vehicle relative to the temporary sewing portion is effectively suppressed.

[0010] Also, The 3 aspect The vehicle curtain airbag device of The 1 aspect The vehicle curtain airbag device of 1, wherein two temporary sewing portions are formed vertically along the longitudinal direction of the vehicle, and the length of the upper one is formed longer than the length of the lower one.

[0011] The 3 aspect According to the invention, two temporary sewing parts are formed vertically along the longitudinal direction of the vehicle, and the upper one is formed to be longer than the lower one. Therefore, when folding the curtain airbag, it can be folded inward in the vehicle width direction along the virtual straight line connecting the end of the upper temporary sewing part and the end of the lower temporary sewing part. As a result, when the sub-chamber expands and deploys, the folded part will deploy from the inner side to the outer side in the vehicle width direction, so that the lower end of the sub-chamber during the expansion and deployment is effectively suppressed from riding on the upper surface of the door trim.

[0012] Also, The 4 aspect the vehicle curtain airbag device of The 1 to The any one of 3 two aspects is a vehicle curtain airbag device, and the temporary sewing part is provided at a position away from the lower edge of the sub-chamber toward the upper side of the vehicle.

[0013] The 4 aspect According to the invention, the temporary sewing part is provided at a position away from the lower edge of the sub-chamber toward the upper side of the vehicle. That is, a flow path for gas to flow is secured between the temporary sewing part and the lower edge of the sub-chamber. Therefore, compared with the case where no flow path for gas to flow is secured between the temporary sewing part and the lower edge of the sub-chamber, the temporary sewing part is more likely to break before the curtain airbag is fully inflated and deployed.

Effect of the Invention

[0014] As described above, according to the present invention, it is possible to suppress the sub-chamber during the expansion and deployment from riding on the upper surface of the door trim.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. For convenience of explanation, in each figure, the arrow UP shown as appropriate is the upward direction of the vehicle, the arrow FR is the forward direction of the vehicle, and the arrow RH is the rightward direction of the vehicle. Therefore, in the following description, when the directions of up and down, front and back, and left and right are described without special mention, they indicate up and down, front and back, and left and right in the vehicle. Also, the left and right directions are synonymous with the vehicle width direction.

[0017] In addition, in the present embodiment, a sedan-type automobile 10 is taken as an example of the vehicle, and the case where the occupant P is seated on the vehicle seat 12 for the front seat and the vehicle seat 14 for the rear seat, respectively, is taken as an example. Each occupant P is a dummy for a collision test, and this dummy is, for example, AM50 (50th percentile of American adult males) of the World Side Impact Dummy (World SID).

[0018] In addition, each occupant P is seated on each vehicle seat 12, 14 in the seating method defined by the side collision test method, and is restrained by the seat belts of the three-point seat belt devices (not shown) on each vehicle seat 12, 14. In the following, the occupant P seated on the vehicle seat 12 for the front seat may be referred to as "front seat occupant Pf", and the occupant P seated on the vehicle seat 14 for the rear seat may be referred to as "rear seat occupant Pr".

[0019] <First Embodiment> First, the first embodiment will be described. As shown in FIG. 1, the vehicle curtain airbag device 40 according to the present embodiment mounted on the automobile 10 includes a curtain airbag 50 that expands and deploys by being supplied with gas, an inflater 42 that supplies gas into the curtain airbag 50, and a control device 30 that controls the operation of the inflater 42.

[0020] The curtain airbag 50 and the inflater 42 are respectively provided on both the left and right sides of the automobile 10. That is, the vehicle curtain airbag device 40 includes a pair of left and right curtain airbags 50 and a pair of left and right inflators 42. In FIGS. 1 to 8, the vehicle curtain airbag device 40 provided on the right side of the automobile 10 is shown, and in the following, the vehicle curtain airbag device 40 on the right side will be taken as an example for description.

[0021] The curtain airbag 50 is configured to expand and deploy in a curtain shape along the front side glass 16, the upper half portion of the center pillar (hereinafter referred to as "B pillar") 28, and the rear side glass 18. Therefore, the longitudinal direction of this curtain airbag 50 is the longitudinal direction. The specific configuration of the curtain airbag 50 will be described in detail later.

[0022] The inflator 42 is a gas generator for instantaneously supplying gas to the inside of the curtain airbag 50, and is disposed near the substantially middle portion in the longitudinal direction of the curtain airbag 50 (near the B pillar 28). Specifically, the inflator 42 is formed in a substantially cylindrical shape, and is fixed to the roof side rail 22 that constitutes the roof side portion 20 via a bracket (not shown) so that its axial center portion is disposed along the substantially front-rear direction.

[0023] The gas ejection port 44 provided at one axial end portion (in this case, the front end portion) of the inflator 42 is connected by being inserted into the connection passage 48 formed in the substantially middle portion in the longitudinal direction of the curtain airbag 50 from the rear side. Thereby, the inside of the gas ejection port 44 and the inside of the curtain airbag 50 are configured to be communicable. The outer peripheral surface of the gas ejection port 44 and the inner peripheral surface of the connection passage 48 are in a close contact structure, and are configured so that gas does not leak therebetween.

[0024] Also, as shown in FIG. 1, the left and right inflators 42 are electrically connected to an airbag ECU (Electronic Control Unit) 32 provided in the vehicle 10, respectively. The airbag ECU 32 is electrically connected to a side impact sensor 34, an oblique impact sensor 36, and a rollover sensor 38 provided in the vehicle 10, respectively.

[0025] The side collision sensor 34 is configured to detect or predict a side collision of the vehicle 10 and output a side collision signal to the airbag ECU 32. The oblique collision sensor 36 is configured to detect or predict an oblique collision of the vehicle 10 and output an oblique collision signal to the airbag ECU 32. And the rollover sensor 38 is configured to detect or predict a rollover (tipping over) of the vehicle 10 and output a rollover signal to the airbag ECU 32.

[0026] When a side collision signal or an oblique collision signal is input, the airbag ECU 32 is configured to activate the inflater 42 on the side collision side or the oblique collision side (near side). As a result, the near side curtain airbag 50 receives the supply of gas and inflates and deploys. Also, when a rollover signal is input, the airbag ECU 32 is configured to activate the left and right inflaters 42.

[0027] In addition, when a rollover signal is input after a side collision or an oblique collision, the airbag ECU 32 is configured to activate the inflater 42 on the side opposite to the near side (far side) that has already been activated. Also, the control device 30 is constituted by the airbag ECU 32, the side collision sensor 34, the oblique collision sensor 36, and the rollover sensor 38.

[0028] The curtain airbag 50 is integrally woven in a bag shape by, for example, the One Piece Woven (abbreviated as OPW) method. In the OPW method, a seamless bag body is formed by using a jacquard loom to simultaneously weave two base fabrics and perform multi-layer weaving at necessary locations.

[0029] Note that the manufacturing method of the curtain airbag 50 is not limited to the above-described OPW method. For example, the curtain airbag 50 may be manufactured by cutting out one or a plurality of base fabrics made of a polyamide-based or polyester-based fabric material and sewing them into a bag shape.

[0030] As shown in FIG. 2, the curtain airbag 50 includes a front-seat main chamber 54 and a rear-seat main chamber 58 as main chambers, a front-seat sub-chamber 52 as a sub-chamber provided on the front side of the front-seat main chamber 54, and a rear-seat sub-chamber 56 as a sub-chamber provided between the front-seat main chamber 54 and the rear-seat main chamber 58 (provided on the front side of the rear-seat main chamber 58).

[0031] Further, the curtain airbag 50 includes a gas supply passage 55 that interconnects the front-seat main chamber 54 and the rear-seat main chamber 58. The gas supply passage 55 is mainly formed at the upper part in the substantially middle portion in the longitudinal direction of the curtain airbag 50, and interconnects the upper part of the front-seat main chamber 54 and the upper part of the rear-seat main chamber 58. From the upper end portion of this gas supply passage 55, the above-described connection passage 48 extends upward and rearward.

[0032] Also, an outer peripheral non-inflatable portion 60 is formed at the outer peripheral edge portion of the curtain airbag 50. That is, this outer peripheral non-inflatable portion 60 continuously constitutes the upper edge portion, lower edge portion, front edge portion, and rear edge portion of the curtain airbag 50. Further, a plurality of non-inflatable portions 62, 64, 66, 68 for partitioning the respective chambers 52, 54, 56, 58 and the gas supply passage 55 are formed in the curtain airbag 50.

[0033] The front-seat main chamber 54 expands and deploys between the head PfH of the front-seat occupant Pf and the side portion of the vehicle compartment (front side glass 16), and is configured to restrain and protect the head PfH of the front-seat occupant Pf at least during a side collision (see FIG. 1). The front-seat sub-chamber 52 expands and deploys toward the front side of the front-seat main chamber 54, and is configured to restrain and protect the head PfH of the front-seat occupant Pf during an oblique collision and a rollover.

[0034] Note that the front-seat sub-chamber 52 is located approximately at the vertical center of the front side of the curtain airbag 50 and is partitioned from the front-seat main chamber 54 by a non-inflated portion 62 extending in the vertical direction. Gas is supplied from the front-seat main chamber 54 to the front-seat sub-chamber 52 through throttle passages 51 and 53.

[0035] That is, throttle passages 51 and 53 are respectively formed between the upper end 62A of the non-inflated portion 62 and the upper edge of the curtain airbag 50, and between the lower end 62B of the non-inflated portion 62 and the lower edge of the curtain airbag 50. The front-seat sub-chamber 52 and the front-seat main chamber 54 communicate with each other through the respective throttle passages 51 and 53.

[0036] Also, a front tongue portion 72 having a trapezoidal shape is formed at the front end of the lower edge of the outer peripheral non-inflated portion 60 in a side view seen from the vehicle width direction. This front tongue portion 72 extends below the door belt line BL passing through the lower edge of the window frame (the upper edge of the door trim 77 of the front side door 76) (see FIG. 1).

[0037] Thereby, sliding resistance (frictional force) of the front tongue portion 72 against the surface facing the inner side in the vehicle width direction of the door trim 77 (the surface facing the shoulder of the occupant Pf in the vehicle width direction) is obtained, and the movement of the curtain airbag 50 outward in the vehicle width direction (the direction away from the head PfH of the occupant Pf) is suppressed or prevented (the reaction force of the curtain airbag 50 is ensured).

[0038] Note that the length of the front tongue portion 72 along the vertical direction is about 100 mm. A predetermined region from the lower front part of the front-seat main chamber 54 to the lower end of the front-seat sub-chamber 52 protrudes to the front tongue portion 72, and the protruding portion (the portion where the throttle passage 53 is formed) also forms a part of the sub-chamber.

[0039] The rear seat main chamber 58 expands and unfolds between the head PrH of the rear seat occupant Pr and the side portion of the passenger compartment (rear side glass 18), and is configured to restrain and protect the head PrH of the rear seat occupant Pr at least during a side collision (see FIG. 1). The rear seat sub-chamber 56 expands and unfolds between the front seat main chamber 54 and the rear seat main chamber 58, and is configured to restrain and protect the head PrH of the rear seat occupant Pr during an oblique collision and a rollover.

[0040] Note that the rear seat sub-chamber 56 is partitioned from the gas supply passage 55 by a non-inflatable portion 64 that extends in the front-rear direction on the upper side of the curtain airbag 50. And this rear seat sub-chamber 56 is partitioned into an upper chamber 56A and a lower chamber 56B by a crank-shaped non-inflatable portion 66 that extends from the substantially middle portion in the front-rear direction of the non-inflatable portion 64 to the lower rear side of the curtain airbag 50.

[0041] The front end portion 66A of the non-inflatable portion 66 is connected to the substantially middle portion in the front-rear direction of the non-inflatable portion 64, and the rear end portion 66B of the non-inflatable portion 66 extends toward the lower edge portion of the curtain airbag 50 and is connected to the outer peripheral non-inflatable portion 60. And a throttle flow path 59 is formed between the rear end portion 64B of the non-inflatable portion 64 and the rear end portion 66B of the non-inflatable portion 66, and the upper chamber 56A and the rear seat main chamber 58 communicate with each other through the throttle flow path 59. That is, gas is supplied from the rear seat main chamber 58 to the upper chamber 56A through the throttle flow path 59.

[0042] On the other hand, the front end portion 64F of the non-inflatable portion 64 is curved in a substantially "C" shape, and its tip portion 64A extends rearward. And the lower chamber 56B is partitioned from the front seat main chamber 54 by a substantially inverted "V" shaped non-inflatable portion 68 formed at the substantially middle portion in the front-rear direction of the curtain airbag 50. The front end portion 68A of the non-inflatable portion 68 extends toward the lower edge portion of the curtain airbag 50 and is connected to the outer peripheral non-inflatable portion 60. And the rear end portion 68B of the non-inflatable portion 68 extends rearward.

[0043] That is, the region from the front end portion 64F to the tip portion 64A of the non-inflated portion 64 and the region from the upper end portion 68U to the rear end portion 68B of the non-inflated portion 68 are arranged substantially parallel to each other vertically. And a throttle passage 57 is formed between the upper end portion 68U of the non-inflated portion 68 and the front end portion 64F of the non-inflated portion 64, and the lower chamber 56B and the front seat main chamber 54 communicate with each other through the throttle passage 57. That is, gas is supplied from the front seat main chamber 54 to the lower chamber 56B through the throttle passage 57.

[0044] Also, at a portion corresponding to the lower end portion of the rear seat sub-chamber 56 (lower chamber 56B) of the outer peripheral non-inflated portion 60, a rear side tongue portion 74 having a trapezoidal shape is formed in a side view seen from the vehicle width direction. This rear side tongue portion 74 extends downward from the door belt line BL in the same manner as the front side tongue portion 72 (see FIG. 1). Note that the length of the rear side tongue portion 74 along the vertical direction is also about 100 mm. And a predetermined region at the lower end portion of the rear seat sub-chamber 56 (lower chamber 56B) protrudes toward the rear side tongue portion 74, and the protruding portion also forms a part of the sub-chamber.

[0045] Also, a plurality of fixing tabs 46 are extended upward at the upper edge portion of the curtain airbag 50. Each fixing tab 46 is formed by cutting out a base fabric similar to the base fabric of the curtain airbag 50 into a substantially rectangular shape, and is joined by being sewn to the outer peripheral non-inflated portion 60 at the upper edge portion of the curtain airbag 50. Note that each fixing tab 46 may be configured to extend integrally from the outer peripheral non-inflated portion 60 at the upper edge portion of the curtain airbag 50.

[0046] Also, as shown in FIG. 1, each fixing tab 46 is positioned at the roof side portion 20 which is the upper end portion of the side portion of the passenger compartment, and is fixed to the roof side rail 22 including the rear end portion of the front pillar (hereinafter referred to as "A pillar") 24 (the boundary portion between the A pillar 24 and the roof side rail 22) and the front end portion of the rear pillar (hereinafter referred to as "C pillar") 26 (the boundary portion between the C pillar 26 and the roof side rail 22).

[0047] That is, each fixed tab 46 is fixed to the roof side rail 22 extending from the rear end portion of the A-pillar 24 to the front end portion of the C-pillar 26 by fastening means such as clips, bolts, and nuts (not shown). And the curtain airbag 50 is configured to be stored in the roof side portion 20 together with the inflator 42 in a state of being folded in a roll shape with the substantially front-rear direction as the axial direction and formed in a long shape.

[0048] In the vehicle curtain airbag device 40 configured as described above, when the inflator 42 operates, the gas ejected from the inflator 42 is supplied to the front seat main chamber 54 and the rear seat main chamber 58 through the connection passage 48 and the gas supply passage 55. As a result, the front seat main chamber 54 expands and deploys between the head PfH of the front seat occupant Pf and the front side glass 16, and the rear seat main chamber 58 expands and deploys between the head PrH of the rear seat occupant Pr and the rear side glass 18.

[0049] Also, a part of the gas supplied to the front seat main chamber 54 is supplied to the front seat sub-chamber 52 through the throttle flow paths 51 and 53 and is supplied to the lower chamber 56B of the rear seat sub-chamber 56 through the throttle flow path 57. And a part of the gas supplied to the rear seat main chamber 58 is supplied to the upper chamber 56A of the rear seat sub-chamber 56 through the throttle flow path 59. As a result, the front seat sub-chamber 52 and the rear seat sub-chamber 56 start to expand later than the front seat main chamber 54 and the rear seat main chamber 58.

[0050] This is because, in the case of an oblique collision and a rollover, the timing of contact between the head PfH of the front seat occupant Pf and the head PrH of the rear seat occupant Pr with the curtain airbag 50 is delayed compared to the case of a side collision. That is, in the case of a side collision, before the expansion of the front seat sub-chamber 52 and the rear seat sub-chamber 56 is completed, the head PfH of the front seat occupant Pf and the head PrH of the rear seat occupant Pr come into contact with the front seat main chamber 54 and the rear seat main chamber 58 and are restrained and protected.

[0051] Thus, at the timing when the head PfH of the front seat passenger Pf and the head PrH of the rear seat passenger Pr are restrained and protected by the front seat main chamber 54 and the rear seat main chamber 58, the internal pressure of the front seat main chamber 54 and the rear seat main chamber 58 is higher than the internal pressure of the front seat sub-chamber 52 and the rear seat sub-chamber 56.

[0052] Also, as shown in FIG. 2, temporary sewing portions 80 are provided at the lower end portions of the front seat sub-chamber 52 and the lower chamber 56B of the rear seat sub-chamber 56. Specifically, in a predetermined region at the lower end portion of the front seat sub-chamber 52 including the portion projecting to the front tongue portion 72, two longitudinal sewing portions 82 extending in a predetermined length in the vertical direction as the temporary sewing portion 80 are formed at a predetermined interval in the front-rear direction (so as to be parallel to each other). In this case, the predetermined interval is, for example, an interval that divides the length along the front-rear direction from the lower end portion 62B of the non-inflatable portion 62 to the front edge portion (the most front side portion where gas flows in) of the front seat sub-chamber 52 into approximately three equal parts.

[0053] Similarly, in a predetermined region at the lower end portion of the lower chamber 56B including the portion projecting to the rear tongue portion 74, two longitudinal sewing portions 84 extending in a predetermined length in the vertical direction as the temporary sewing portion 80 are formed at a predetermined interval in the front-rear direction (so as to be parallel to each other). In this case, the predetermined interval is, for example, an interval that divides the length along the front-rear direction from the front edge portion (the front side portion where gas flows in) to the rear edge portion (the rear side portion where gas flows in) of the lower chamber 56B in the portion projecting to the rear tongue portion 74 into approximately three equal parts. Also, the longitudinal sewing portion 82 and the longitudinal sewing portion 84 are formed at positions straddling the door belt line BL (see FIG. 1).

[0054] In addition, the longitudinal sewing parts 82 and 84 as the temporary sewing part 80 are sewn with a sewing pitch larger than the sewing pitch of the non-expansion part 60 of the outer periphery or with a thin thread so that they do not break at the initial stage of inflation deployment (when contacting the door trim 77 of the front side door 76) and break at the completion of inflation deployment. That is, the longitudinal sewing parts 82 and 84 are configured so as not to be cut until a certain degree of inflation of the curtain airbag 50, in other words, to be cut when the curtain airbag 50 exceeds a predetermined degree of inflation.

[0055] Note that the longitudinal sewing parts 82 and 84 as the temporary sewing part 80 may be only one each as shown in FIG. 3. In this case, the longitudinal sewing part 82 may be formed, for example, at a substantially middle position in the longitudinal direction from the lower end part 62B of the non-expansion part 62 to the front edge part of the front seat sub-chamber 52. Similarly, in this case, the longitudinal sewing part 84 may be formed, for example, at a substantially middle position in the longitudinal direction from the front edge part to the rear edge part of the lower chamber 56B in the part protruding to the rear side tongue part 74.

[0056] Also, as shown in FIGS. 2 and 3, the lower end part of the longitudinal sewing part 82 is provided at a position separated upward by a predetermined width W from the lower edge part (the lowermost part where gas flows in) of the front seat sub-chamber 52. That is, a flow path with a predetermined width W continuous from the throttle flow path 53 is secured between the lower end part of the longitudinal sewing part 82 and the lower edge part of the front seat sub-chamber 52.

[0057] Similarly, the lower end part of the longitudinal sewing part 84 is provided at a position separated upward by a predetermined width W from the lower edge part (the lowermost part where gas flows in) of the lower chamber 56B. That is, a flow path with a predetermined width W continuous from the throttle flow path 57 is secured between the lower end part of the longitudinal sewing part 84 and the lower edge part of the lower chamber 56B. Note that the predetermined width W may be the same width on the front seat sub-chamber 52 side and the lower chamber 56B side, or may be different widths.

[0058] Next, the operation of the vehicle curtain airbag device 40 according to the first embodiment configured as described above will be described. Since the front seat side and the rear seat side are the same, the front seat side will be described as an example here. Further, as an example, the case where the two longitudinal seams 82 are formed side by side with a predetermined interval in the front-rear direction as shown in FIG. 2 will be adopted.

[0059] For example, when the rollover sensor 38 detects that the vehicle 10 has rolled over, a rollover signal is sent from the rollover sensor 38 to the airbag ECU 32. When the rollover signal is input to the airbag ECU 32, the airbag ECU 32 activates the left and right inflators 42 and instantaneously jets gas into the left and right curtain airbags 50.

[0060] As a result, as shown in FIG. 4, the curtain airbag 50 begins to expand and deploy. That is, first, the front seat main chamber 54 expands and deploys due to the gas supplied through the gas supply passage 55. Next, gas is supplied from the front seat main chamber 54 to the front seat sub-chamber 52 through the throttle passages 51 and 53, and the front seat sub-chamber 52 attempts to expand and deploy.

[0061] Here, a longitudinal seam 82 is provided at the lower end of the front seat sub-chamber 52 as a temporary sewing portion 80. This longitudinal seam 82 is formed so as not to tear at the initial stage of expansion and deployment and to tear at the completion of expansion and deployment. Therefore, at the initial stage of expansion and deployment, it is difficult for gas to flow between the longitudinal seams 82 and below the longitudinal seams 82. As exaggeratedly shown in FIG. 4, a part (lower end portion) of the front seat sub-chamber 52 below the longitudinal seam 82 expands downward while remaining thinner than the thickness of the front seat sub-chamber 52 above the longitudinal seam 82 and the thickness of the lower end portion when the longitudinal seam 82 is not provided (shown by a virtual line) (while having a small bulge).

[0062] This can suppress or avoid the lower end of the front-seat sub-chamber 52 during inflation and deployment from riding up on the upper surface of the door trim 77 of the front side door 76. That is, the lower end of the front-seat sub-chamber 52 is disposed on the surface side facing the inner side in the vehicle width direction of the door trim 77. Therefore, it is possible to suppress or prevent the curtain airbag 50, whose longitudinal seam portion 82 has been cut and has reached the final inflated and deployed shape, from moving outward in the vehicle width direction (the direction away from the head PfH of the occupant Pf), and it is possible to suppress or prevent a decrease in the restraint performance with respect to the head PfH of the occupant Pf.

[0063] Further, in the vehicle curtain airbag device 40 according to the first embodiment, since the temporary sewing portion 80 is the longitudinal seam portion 82 formed along the vertical direction, it is possible to effectively suppress the inflow of gas to the lower side than the longitudinal seam portion 82 at the initial stage of inflation and deployment of the front-seat sub-chamber 52. That is, at the initial stage of inflation and deployment, it is possible to appropriately control the thickness of a part (lower end portion) of the front-seat sub-chamber 52 below the longitudinal seam portion 82.

[0064] Also, the lower end portion of the longitudinal seam portion 82 is provided at a position separated upward from the lower edge portion of the front-seat sub-chamber 52, and a gas flow path having a predetermined width W is secured between the lower end portion of the longitudinal seam portion 82 and the lower edge portion of the front-seat sub-chamber 52. Therefore, compared with the case where the lower end portion of the longitudinal seam portion 82 is provided up to the position reaching the lower edge portion of the front-seat sub-chamber 52 and no gas flow path is secured between the lower end portion of the longitudinal seam portion 82 and the lower edge portion of the front-seat sub-chamber 52, the longitudinal seam portion 82 is more likely to be cut by the time the inflation and deployment of the curtain airbag 50 is completed. In other words, it is possible to suppress or prevent the occurrence of a problem that the longitudinal seam portion 82 is not cut and the curtain airbag 50 does not take the finally inflated and deployed shape.

[0065] <Second Embodiment> Next, the second embodiment will be described. Note that the same reference numerals are given to the parts equivalent to those in the first embodiment above, and detailed descriptions (including common operations) are omitted as appropriate.

[0066] As shown in FIG. 5, in the curtain airbag device 40 according to this second embodiment, the temporary sewing portions 80 formed at the lower end of the front seat sub-chamber 52 and the lower end of the lower chamber 56B are the transverse sewing portions 86 and 88 respectively, instead of the longitudinal sewing portions 82 and 84, which is the only difference from the first embodiment.

[0067] That is, the transverse sewing portion 86 as the temporary sewing portion 80 formed at the lower end of the front seat sub-chamber 52 including the portion protruding to the front tongue portion 72 extends in the front-rear direction with a predetermined length, and is provided, for example, at a substantially middle portion in the front-rear direction length from the lower end portion 62B of the non-inflated portion 62 to the front edge portion of the front seat sub-chamber 52. In other words, the length along the front-rear direction from the front end portion of the transverse sewing portion 86 to the front edge portion of the front seat sub-chamber 52 and the length along the front-rear direction from the rear end portion of the transverse sewing portion 86 to the lower end portion 62B of the non-inflated portion 62 are substantially the same.

[0068] Similarly, the transverse sewing portion 88 as the temporary sewing portion 80 formed at the lower end of the lower chamber 56B including the portion protruding to the rear tongue portion 74 extends in the front-rear direction with a predetermined length, and is provided, for example, at a substantially middle portion in the front-rear direction length from the front edge portion to the rear edge portion of the lower chamber 56B in the portion protruding to the rear tongue portion 74. In other words, the length along the front-rear direction from the front end portion of the transverse sewing portion 88 to the front edge portion of the lower chamber 56B and the length along the front-rear direction from the rear end portion of the transverse sewing portion 88 to the rear edge portion of the lower chamber 56B are substantially the same.

[0069] And the transverse sewing portion 86 is provided at a position separated upward by a predetermined width W from the lower edge portion of the front seat sub-chamber 52, and a flow path with a predetermined width W continuous from the throttle flow path 53 is secured between the transverse sewing portion 86 and the lower edge portion of the front seat sub-chamber 52. Similarly, the transverse sewing portion 88 is provided at a position separated upward by a predetermined width W from the lower edge portion of the lower chamber 56B, and a flow path with a predetermined width W continuous from the throttle flow path 57 is secured between the transverse sewing portion 88 and the lower edge portion of the lower chamber 56B. Note that the predetermined width W may be the same width on the front seat sub-chamber 52 side and the lower chamber 56B side, or may be different widths.

[0070] In the vehicle curtain airbag device 40 according to the second embodiment configured as described above, similar to the first embodiment, taking the front seat sub-chamber 52 side as an example for explanation, at the initial stage of inflation and deployment, it becomes difficult for gas to flow downward from the horizontal seam portion 86. Therefore, as exaggeratedly shown in FIG. 6, a part (lower end portion) of the front seat sub-chamber 52 below the horizontal seam portion 86 is in a state where its thickness is thinner than the thickness of the front seat sub-chamber 52 above the horizontal seam portion 86 and the thickness of the lower end portion when the horizontal seam portion 86 is not provided (shown by the virtual line), and it expands downward on the vehicle side while remaining in a state with a small bulge.

[0071] Thereby, it is possible to suppress or avoid the lower end portion of the front seat sub-chamber 52 during inflation and deployment from riding on the upper surface of the door trim 77 of the front side door 76. That is, the lower end portion of the front seat sub-chamber 52 is disposed on the surface side facing the inner side in the vehicle width direction of the door trim 77. Therefore, it is possible to suppress or prevent the curtain airbag 50, which has the horizontal seam portion 86 cut and has the final inflated and deployed shape, from moving outward in the vehicle width direction (the direction away from the head PfH of the occupant Pf), and it is possible to suppress or prevent the restraint performance for the head PfH of the occupant Pf from deteriorating.

[0072] Further, in the vehicle curtain airbag device 40 according to the second embodiment, since the temporary sewing portion 80 is the horizontal seam portion 86 formed along the front-rear direction, at the initial stage of inflation and deployment of the front seat sub-chamber 52, it is possible to effectively suppress the inflow of gas downward from the horizontal seam portion 86. That is, at the initial stage of inflation and deployment, it is possible to appropriately control the thickness of a part (lower end portion) of the front seat sub-chamber 52 below the horizontal seam portion 86.

[0073] Further, the horizontal seam portion 86 is provided at a position away from the lower edge portion of the front seat sub-chamber 52 upward, and a gas flow path having a predetermined width W is secured between the horizontal seam portion 86 and the lower edge portion of the front seat sub-chamber 52. Therefore, compared with the case where no gas flow path is secured between the horizontal seam portion 86 and the lower edge portion of the front seat sub-chamber 52, the horizontal seam portion 86 is more likely to be cut before the curtain airbag 50 is fully inflated and deployed. In other words, it is possible to suppress or prevent the occurrence of a problem that the horizontal seam portion 86 is not cut and the curtain airbag 50 does not take the final inflated and deployed shape.

[0074] <Third Embodiment> Finally, the third embodiment will be described. Note that the same reference numerals are given to the parts equivalent to those in the second embodiment above, and detailed descriptions (including common operations) are omitted as appropriate.

[0075] As shown in FIG. 7, in the curtain airbag device 40 according to this third embodiment, the horizontal seam portions 86 and 88 as the temporary sewing portions 80 formed at the lower end portion of the front seat sub-chamber 52 and the lower end portion of the lower chamber 56B are each two, and are formed at a predetermined interval in the vertical direction (so as to be parallel to each other). This is the only difference from the second embodiment.

[0076] The upper horizontal seam portion 86A and the lower horizontal seam portion 86B of the horizontal seam portion 86 have different lengths along the front-rear direction, and the upper horizontal seam portion 88A and the lower horizontal seam portion 88B of the horizontal seam portion 88 have different lengths along the front-rear direction. That is, the upper horizontal seam portion 86A is formed to be longer in length along the front-rear direction than the lower horizontal seam portion 86B, and the upper horizontal seam portion 88A is formed to be longer in length along the front-rear direction than the lower horizontal seam portion 88B.

[0077] Further, the upper horizontal seam portion 86A and the lower horizontal seam portion 86B in the horizontal seam portion 86 have the same position in the front-rear direction at the rear end portion and different positions in the front-rear direction at the front end portion. And, the upper horizontal seam portion 88A and the lower horizontal seam portion 88B in the horizontal seam portion 88 have different positions in the front-rear direction at both the rear end portion and the front end portion. Thereby, a configuration is formed in which a virtual straight line K connecting the front end portions of the upper horizontal seam portion 86A and the lower horizontal seam portion 86B and a virtual straight line K connecting the rear end portions of the upper horizontal seam portion 88A and the lower horizontal seam portion 88B are formed.

[0078] Further, the upper horizontal seam portion 86A is provided, for example, at a substantially middle portion in the front-rear direction along the length from the lower end portion 62B of the non-inflation portion 62 to the front edge portion of the front seat sub-chamber 52. In other words, the length in the front-rear direction from the front end portion of the upper horizontal seam portion 86A to the front edge portion of the front seat sub-chamber 52 and the length in the front-rear direction from the rear end portion of the upper horizontal seam portion 86A to the lower end portion 62B of the non-inflation portion 62 are substantially the same.

[0079] Similarly, the upper horizontal seam portion 88A and the lower horizontal seam portion 88B are each provided, for example, at a substantially middle portion in the front-rear direction along the length from the front edge portion to the rear edge portion of the lower chamber 56B in the portion protruding from the rear tongue portion 74. In other words, the length in the front-rear direction from the front end portions of the upper horizontal seam portion 88A and the lower horizontal seam portion 88B to the front edge portion of the lower chamber 56B and the length in the front-rear direction from the rear end portions of the upper horizontal seam portion 88A and the lower horizontal seam portion 88B to the rear edge portion of the lower chamber 56B are substantially the same.

[0080] And the lower horizontal slit portion 86B is provided at a position separated upward by a predetermined width W from the lower edge portion of the front seat sub-chamber 52, and a flow path with a predetermined width W continuous from the throttle flow path 53 is secured between the lower horizontal slit portion 86B and the lower edge portion of the front seat sub-chamber 52. Similarly, the lower horizontal slit portion 88B is provided at a position separated upward by a predetermined width W from the lower edge portion of the lower chamber 56B, and a flow path with a predetermined width W continuous from the throttle flow path 57 is secured between the lower horizontal slit portion 88B and the lower edge portion of the lower chamber 56B. Note that the predetermined width W may be the same width on the front seat sub-chamber 52 side and the lower chamber 56B side, or may be different widths.

[0081] In the vehicle curtain airbag device 40 according to the third embodiment configured as described above, similar to the first and second embodiments, taking the front seat sub-chamber 52 side as an example for explanation, at the initial stage of inflation and deployment, it becomes difficult for gas to flow below the lower horizontal slit portion 86B. Therefore, as exaggeratedly shown in FIG. 8, a part (lower end portion) of the front seat sub-chamber 52 below the lower horizontal slit portion 86B unfolds downward toward the vehicle while remaining thinner (with a smaller bulge) than the thickness of the front seat sub-chamber 52 above the upper horizontal slit portion 86A and the thickness of the lower end portion when the horizontal slit portion 86 is not provided (shown by the virtual line).

[0082] Thereby, it is possible to suppress or avoid the lower end portion of the front seat sub-chamber 52 during inflation and deployment from riding up on the upper surface of the door trim 77 of the front side door 76. That is, the lower end portion of the front seat sub-chamber 52 is disposed on the surface side facing the inner side in the vehicle width direction of the door trim 77. Therefore, it is possible to suppress or prevent the curtain airbag 50, in which the upper horizontal slit portion 86A and the lower horizontal slit portion 86B are cut and which has the final inflated and deployed shape, from moving outward in the vehicle width direction (in a direction away from the head PfH of the occupant Pf), and it is possible to suppress or prevent the restraint performance with respect to the head PfH of the occupant Pf from deteriorating.

[0083] Also, in the vehicle curtain airbag device 40 according to the third embodiment, since the temporary sewing portion 80 is composed of two upper and lower horizontal sewing portions 86 formed along the front-rear direction, that is, the upper horizontal sewing portion 86A and the lower horizontal sewing portion 86B, at the initial stage of inflation and deployment of the front passenger sub-chamber 52, the inflow of gas downward from the upper horizontal sewing portion 86A and the lower horizontal sewing portion 86B can be effectively suppressed. That is, at the initial stage of inflation and deployment, the thickness of a part (lower end portion) of the front passenger sub-chamber 52 below the horizontal sewing portion 86 can be appropriately controlled.

[0084] Also, the lower horizontal sewing portion 86B is provided at a position away from the lower edge portion of the front passenger sub-chamber 52 upward, and a gas flow path having a predetermined width W is secured between the lower horizontal sewing portion 86B and the lower edge portion of the front passenger sub-chamber 52. Therefore, the upper horizontal sewing portion 86A and the lower horizontal sewing portion 86B are more likely to be cut before the inflation and deployment of the curtain airbag 50 is completed compared to the case where no gas flow path is secured between the lower horizontal sewing portion 86B and the lower edge portion of the front passenger sub-chamber 52. In other words, it is possible to suppress or prevent the occurrence of a problem that the upper horizontal sewing portion 86A and the lower horizontal sewing portion 86B are not cut and the curtain airbag 50 does not take the finally inflated and deployed shape.

[0085] Also, the length of the upper horizontal sewing portion 86A along the front-rear direction is formed longer than the length of the lower horizontal sewing portion 86B along the front-rear direction. Therefore, when folding the curtain airbag 50, it can be easily folded inward in the vehicle width direction along an imaginary straight line K connecting the front end portion of the upper horizontal sewing portion 86A and the front end portion of the lower horizontal sewing portion 86B.

[0086] As a result, when the front passenger sub-chamber 52 inflates and deploys, the folded portion (the portion below and in front of the horizontal sewing portion 86) expands from the inner side in the vehicle width direction toward the outer side in the vehicle width direction, and the lower end portion of the front passenger sub-chamber 52 is more likely to be arranged on the surface side facing the inner side in the vehicle width direction of the door trim 77. Therefore, it is possible to effectively suppress or avoid the lower end portion of the front passenger sub-chamber 52 including the portion below and in front of the horizontal sewing portion 86 from riding on (getting caught on) the upper surface of the door trim 77.

[0087] As described above, the vehicle curtain airbag device 40 according to the present embodiment has been described with reference to the drawings. However, the vehicle curtain airbag device 40 according to the present embodiment is not limited to the illustrated one, and can be appropriately designed and changed within the scope not departing from the gist of the present invention. For example, three or more longitudinal seams 82 and 84 in the first embodiment and transverse seams 86 and 88 in the third embodiment may be formed respectively.

[0088] Also, although not shown, the temporary sewing portion 80 may be, for example, an inclined seam portion inclined obliquely with respect to the vertical direction and the front-rear direction. Further, the temporary sewing portion 80 may be a substantially "V" - shaped seam portion connecting the lower ends of two longitudinal seams 82 or two longitudinal seams 84, or may be a substantially inverted "V" - shaped seam portion connecting the upper ends of two longitudinal seams 82 or two longitudinal seams 84.

[0089] Also, the lengths of the longitudinal seams 82, 84 and the transverse seams 86, 88 are not limited to the lengths shown in the drawings respectively. The lengths of the longitudinal seams 82, 84 and the transverse seams 86, 88 may be appropriately set according to the shape of the curtain airbag 50 and the like to the extent that the inflow of gas to the lower end of the front seat sub - chamber 52 and the lower end of the lower chamber 56B can be suppressed at the initial stage of inflation and deployment.

Explanation of Reference Numerals

[0090] 10 Automobile (Vehicle) 40 Vehicle curtain airbag device 50 Curtain airbag 52 Front seat sub - chamber (sub - chamber) 54 Front seat main - chamber (main - chamber) 80 Temporary sewing portion Pf Front seat occupant (occupant) PfH Head

Claims

1. A curtain airbag having a sub-chamber that expands and deploys on the front side of the vehicle relative to the main chamber and on the lower side of the vehicle relative to the door belt line by supplying gas through a main chamber that protects the head of an occupant, at least when the vehicle rolls over; A temporary sewing portion provided at the lower end of the sub-chamber, which does not tear at the initial stage of inflation and deployment and tears at the completion of inflation and deployment; Comprising; The vehicle curtain airbag device, wherein the temporary sewing portion is formed along the vertical direction of the vehicle so as to straddle the door belt line.

2. The vehicle curtain airbag device according to claim 1, wherein two temporary sewing portions are formed at intervals in the longitudinal direction of the vehicle.

3. A curtain airbag having a sub-chamber that expands and deploys on the front side of the vehicle relative to the main chamber and on the lower side of the vehicle relative to the door belt line by supplying gas through a main chamber that protects the head of an occupant, at least when the vehicle rolls over; A temporary sewing portion provided at the lower end of the sub-chamber, which does not tear at the initial stage of inflation and deployment and tears at the completion of inflation and deployment; Comprising; The temporary sewing portion is formed in two vertically along the longitudinal direction of the vehicle, The vehicle curtain airbag device, wherein the upper length is formed longer than the lower length.

4. The vehicle curtain airbag device according to any one of claims 1 to 3, wherein the temporary sewing portion is provided at a position away from the lower edge of the sub-chamber toward the upper side of the vehicle.

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