JP2003327070A - Head-protecting air bag device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head-protecting air bag device capable of developing and inflating a portion to be a front side of a gas inflow port part and a portion to be a rear side so that inflation completion time may be substantially equal, even if disposing an inflator on an upper edge side of a window at a vehicle interior side of a vehicle and disposing the gas inflow port part at a substantially intermediate portion in front and rear directions of an air bag. <P>SOLUTION: Two gas injection holes 57 and 58 are formed in the vicinity of a vertical pipe part 55 in a diffuser 52. Opening area A of the first gas injection hole 57 on an original part side of a horizontal pipe part 54 and opening area B of the second gas injection hole 58 on a side away from the original part side of the horizontal pipe part 54 are set to be within a range of an expression shown by b/a>B/A when taking volume of a portion of an inflation shielding part to be a side adjacent to the original part side of the horizontal pipe part 54 and volume of a portion of the inflation shielding part to be a side away from the original part side of the horizontal pipe part 54 as (a) and (b), respectively, by making the gas inflow port part 15 as a boundary. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag which is folded and housed on the upper edge side of a window on the inside of a vehicle, and which expands downward so as to cover the inside of the window when inflating gas flows in. , A cylinder-type inflator for supplying inflation gas to the airbag, and a head protection airbag apparatus.

[0002]

2. Description of the Related Art Conventionally, as a head protection airbag device having the above-mentioned structure, there has been a structure shown in Japanese Patent Laid-Open No. 2001-277987. This airbag device is provided with an airbag that is folded and housed on the upper edge side of a window on the inside of the vehicle, and a center pillar portion of the vehicle that is a substantially intermediate portion in the front-rear direction of the airbag. And a cylinder type inflator arranged along the direction. A substantially T-shaped diffuser that distributes the inflation gas in the front-rear direction was connected to the inflator. Then, by connecting this diffuser to a gas inlet provided in the vicinity of the center of the airbag in the front-rear direction, the airbag allows the inflation gas discharged from the inflator to flow into the airbag, and then to the front and rear of the center pillar portion. It was configured to expand and inflate so as to cover the inside of the vehicle of the window provided.

However, the above publication does not disclose any distribution of the inflation gas when the inflator is arranged on the roof side rail portion.

In addition, in this type of airbag device, a portion on the front side of the gas inlet portion of the airbag and a portion on the rear side of the gas inlet portion are inflated so that the completion time of inflation is substantially equal. It is preferable.

The present invention is to solve the above-mentioned problems, and a gas inflow port is provided at a substantially intermediate portion in the front-rear direction of an airbag as a structure in which an inflator is arranged on the upper edge side of a window inside a vehicle. Even if it is arranged, the head protection that can inflate and inflate the portion on the front side of the gas inlet portion of the airbag and the portion on the rear side of the airbag so that the inflation completion times are substantially equal. An object is to provide an airbag device.

[0006]

A head protection airbag device according to the present invention is folded and housed on the upper edge side of a window on the inside of a vehicle so that when the inflation gas flows in, the inside of the window is closed. The airbag is configured to include an airbag that expands downward so as to cover the airbag, and an inflator that supplies inflation gas to the airbag. The inflator is disposed on the upper edge side of the window inside the vehicle, Is provided with a portion for inflating the inflation gas to inflate so as to separate the vehicle interior side wall portion and the vehicle exterior side wall portion from each other, and an inflation shielding portion that shields the vehicle interior side of the window and a substantially intermediate portion in the front-rear direction of the airbag. A head protection airbag device having a configuration in which one gas inflow port is provided so as to project upward on the upper edge side of the inflow port and allows the inflating gas from the inflator to flow into the expansion shield. , The expansion gas from the inflator can flow into the expansion shielding part by being connected so as to be inserted into the gas inlet part, and the lateral pipe part whose axial direction is substantially aligned with the longitudinal direction of the vehicle, A diffuser configured to include a vertical pipe portion extending downward at the tip of the pipe portion is provided, and a diffuser for expansion discharged from the inflator is provided near the lower end of the vertical pipe portion of the diffuser. Two gas ejection holes opened substantially along the inflow direction of the gas in the lateral pipe portion and on the side of the expansion shield portion that is on the front side of the gas inlet port and on the side of the expansion shield portion that is behind the gas inlet port. Is formed and the opening area A of the first gas ejection hole disposed on the base side of the lateral pipe portion in the two gas ejection holes and 2
In the airbag, the opening area B of the second gas ejection hole arranged on the side of the one gas ejection hole away from the base side of the lateral pipe portion is the origin of the lateral pipe portion with the gas inlet port as a boundary. A, the volume into which the inflation gas flows in the portion of the expansion shield portion that is close to the side, and the volume in which the inflation gas flows into the portion of the expansion shield portion that is the side away from the base portion side of the lateral pipe portion. Is set to be b, it is characterized in that it is set within the range of the mathematical expression represented by b / a> B / A.

When the head protecting airbag device is constructed as described above, the opening areas A and B of the first and second gas ejection holes are formed.
Is set in consideration of the volume ratio (b / a) of each portion of the airbag into which the inflation gas flows, whereby the inflation gas flows in the direction opposite to the flow direction of the inflation gas in the lateral pipe portion and the inflation is completed. The part of the expansion shield part that is close to the base part of the horizontal pipe part, which tends to be delayed, and the part of the expansion shield part that is far from the base part of the horizontal pipe part, have almost the same expansion completion time. Then, it can be expanded and inflated.

Therefore, in the head protection airbag apparatus of the present invention, the gas inflow port is arranged at a substantially middle portion in the front-rear direction of the airbag as a structure in which the inflator is disposed on the upper edge side of the window inside the vehicle. Even if it is provided, the portion of the airbag on the front side of the gas inlet portion and the portion on the rear side of the gas inlet portion can be inflated and inflated so that the inflation completion times are substantially equal.

Further, in the head protection airbag apparatus having the above-mentioned structure, the volume for inflowing the inflation gas into the portion of the inflation shield portion which is the side close to the base side of the lateral tube portion of the airbag, and the lateral tube portion. A volume into which the inflation gas is introduced at a portion of the expansion shield portion that is a side away from the base side of
However, the configuration may be set to be substantially equal.

Further, in the head protection airbag device having the above-mentioned structure, the opening area is set at a position at least on one side in the vicinity of the lower end of the vertical pipe portion of the diffuser in a direction substantially orthogonal to the inflow direction of the inflation gas in the horizontal pipe portion. First
It is preferable that the auxiliary gas ejection holes, which are set smaller than the opening areas of the gas ejection holes and the second gas ejection holes, are formed.

If the head protection airbag device is constructed as described above, the completion time of inflation of the airbag can be shortened, and the airbag can be swiftly used even when it is used for an airbag having a large capacity. It is possible to expand and inflate.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a head protection airbag device M, which is an embodiment of the present invention, includes an airbag 12,
Doors and windows W (W1, W2, W) inside the vehicle V
3) The lower edge side of the front pillar portion FP, the lower edge side of the roof side rail portion RR, and the upper side of the rear pillar portion RP in the upper edge side peripheral edge are folded and stored.

The airbag device M comprises an airbag 12, an inflator 43, a diffuser 52, mounting brackets 40 and 47, and an airbag cover 10.

As shown in FIG. 1, the airbag cover 10 includes a pillar garnish 4 arranged in the front pillar portion FP and a roof head lining 5 arranged in the roof side rail portion RR from the lower edge side. It is configured. The airbag cover 10 is arranged so as to cover the inside of the folded and stored airbag 12 and also allows the airbag 12 to be protruded to the inside of the vehicle when expanded and inflated. It is configured so that it can be opened to the inside of the vehicle by being pushed by 12.

As shown in FIG. 5, the airbag 12 comprises an airbag body 13 and an inner tube 36 arranged in the airbag body 13.

The airbag body 13 is manufactured by bag-weaving using polyamide yarn or the like, and as shown in FIG.
Inflate the expansion gas G from the inflator 43,
Unfold the window W (W1, W2, W3) from the folded state,
The rear pillar portion RP and the intermediate pillar portions P1 and P2 are configured to expand and inflate so as to cover the insides of the pillar garnishes 6 and 7 and 8.

Further, the airbag body 13 has an expansion shield part 17, and one gas inlet part 15 for allowing the inflation gas G from the inflator 43 to flow into the expansion shield part 17.
It is the structure provided with. The gas inlet portion 15 is arranged so as to project upward and forward at the upper edge 13a side of the airbag body 13 at a substantially middle portion in the front-rear direction. The gas inlet portion 15 has a substantially cylindrical shape and has a front end 15
a is opened, and the diffuser 5 of the inflator 43 is opened.
It will be externally attached to 2 and will be connected to the inflator 43. Specifically, the gas inlet port 15 is connected to the diffuser 52 by using the clamp 50 described later. The expansion shield part 17 is a gas inflow part 19 that inflates the expansion gas G so as to separate the vehicle interior side wall part 19a and the vehicle exterior side wall part 19b from each other, and a non-inflow part 27 that does not allow the expansion gas G to flow in. It consists of In addition, in the embodiment, in the expansion shield portion 17, the gas inlet portion 1
5 is the boundary, the front side portion is the front shield expansion portion 17
A, and the portion on the rear side is the rear shield inflating portion 17B (see FIG. 5).

In the case of the embodiment, the gas inflow portion 19 is composed of a gas supply passage portion 21, a vertical expansion portion 22, and a communication portion 25.

The gas supply passage 21 is provided in the airbag body 13
The airbag main body 13 is disposed on the upper edge 13a side along the front-rear direction of the vehicle V over substantially the entire length.
The gas supply passage portion 21 is configured to guide the expansion gas G discharged from the inflator 43 to each vertical expansion portion 22. Further, the gas inlet 15 is communicated with the gas supply passage 21 at a substantially intermediate position in the front-rear direction. The communication portion 25 is the lower edge 1 of the airbag body 13.
On the 3b side, the airbag main body 13 is arranged along the front-rear direction of the vehicle V over substantially the entire length.

The vertical expansion section 22 is partitioned into a partition coupling section 31 which will be described later at a portion of the expansion shield section 17 between the gas supply path section 21 and the communication section 25.
A plurality of them are arranged along the front-rear direction of the vehicle V. Each of the vertical expansion sections 22 is for expanding the expansion gas G to expand vertically in a rod shape, and has its lower end side communicated with the communication section 25. Further, the vertical expansion section 22A and the vertical expansion sections 22B and 22C to be arranged below the gas inflow section 15.
As shown in FIG. 5, the upper end of 22D is closed by a lateral coupling portion 32 described later. Another vertical expansion section 22
All have their upper ends communicated with the gas supply passage.

Further, the vertical expansion portion 22E disposed on the front end side.
An auxiliary inflating portion 23, which communicates with the lower end side of the vertical inflating portion 22E, is disposed near the lower end on the front side of the. The auxiliary inflating portion 23 prevents local stress from being generated at the front end portion of the partition connecting portion 31 disposed on the upper end side of the vertical inflating portion 22E when the inflating gas G flows from the inflator 43. It is provided.

The non-inflow portion 27 is formed by connecting the vehicle interior side wall portion 19a and the vehicle exterior side wall portion 19b. In the case of the embodiment, the attachment portion 28, the peripheral edge coupling portion 29, the partition coupling portion 31, And a triangular plate portion 33.

The peripheral connecting portion 29 is arranged around the gas inflow portion 19 at a portion in contact with the gas inflow portion 19 and is tightly woven so that gas leakage does not occur. In the case of the embodiment, the peripheral coupling portion 29 is also arranged around the gas inflow portion 15.

A plurality of attachment portions 28 (eight in the embodiment) are provided so as to project upward from the upper edge side portion 29a of the peripheral edge coupling portion 29 on the upper edge 13a side of the airbag body 13 and the upper edge side of the triangular plate portion 33. ) Is provided. A mounting bracket 40 for mounting the airbag body 13 to the inner panel 2 is fixed to each mounting portion 28, and a mounting hole 28a for inserting the mounting bolt 41 is formed. Then, each mounting portion 28 is fixed to the inner panel 2 made of sheet metal on the body 1 side together with the mounting bracket 40 using the mounting bolts 41.

The triangular plate portions 33 are arranged on the front end side and the rear end side of the airbag body 13. The triangular plate portion 33A arranged on the front end side is arranged so as to project forward from the front edge side of the peripheral edge coupling portion 28. The triangular plate portion 33B arranged on the rear end side is arranged so as to project rearward from the rear edge side of the peripheral edge coupling portion 28.

A plurality of partition connecting portions 31 are arranged along the front-rear direction so as to partition each vertical inflating portion 22 in the area of the expansion shield portion 17. Each partition coupling part 31 has a rod shape extending in the up-down direction, except for the plate-shaped partition coupling part 31A arranged in the region of the front expansion shield 17A. In addition, each of the vertical expansion parts 22A, 22B, 22C, 22D
On the upper end side of each of the vertical expansion parts 22A, 22B, 22C, 2
The horizontal joint portion 32 is arranged so as to connect the upper ends of the respective partition joint portions 31 so as to close the upper end of the 2D. Each horizontal joint portion 32 constitutes the lower edge side of the gas supply passage portion 21 together with the upper edge of the partition joint portion 31A. Then, in particular, the lateral coupling portion 32A arranged on the lower side of the gas inlet portion 15 directs the expansion gas G ejected from the diffuser 52 to the front side and the rear side along the front-rear direction of the vehicle V. It also plays the role of a guide that guides you.

The inner tube 36 is formed of a woven fabric using polyamide yarn, polyester yarn, etc., and is arranged in the gas inlet port 15. The inner tube 36 is attached to the diffuser 52 together with the gas inlet port 15, and has a substantially cylindrical mounting portion 37, and a main body portion 38 disposed in the gas supply passage portion 21 with the front end side and the rear end side opened. When,
It is configured with. And the inflator 43
The inflation gas G discharged from the main body 38 is made to flow out into the airbag main body 13 from the front end and rear end openings of the main body 38.

As shown in FIGS. 1 and 2, the inflator 43 is of a cylinder type for supplying the inflation gas G to the folded airbag 12, and its axial direction is the vehicle V.
Are arranged substantially along the front-back direction. The inflator 43 is configured to include a substantially columnar main body portion 44 and a head portion 45 arranged on the distal end side of the main body portion 44. In the case of the embodiment, the inflator 43 is disposed with the head portion 45 located on the vehicle rear side. The head portion 45 has a diameter smaller than that of the main body 44 and includes a plurality of gas discharge ports 45a for discharging the expansion gas G. The body portion 44 is formed so as to be reduced in diameter toward the head portion 45. On the head portion 45 side of the main body portion 44, flange portions 44a, 44b, 44c protruding outward from the main body portion 44 are arranged substantially orthogonal to the axial direction of the main body portion 44. The flange portions 44a, 44b, and 44c are the diffuser 52.
For fixing to the inflator 43, between the flange portions 44a and 44b, and the flange portion 4
The diffuser 52 is fixed to the inflator 43 by caulking the fixing portions 54a and 54b of the diffuser 52, which will be described later, between the 4b and 44c.

The mounting brackets 47 are arranged at two places as shown in FIGS. Each mounting bracket 47
Is made of sheet metal and is attached to the inner panel 2 on the body 1 side on the vehicle inner side of the roof side rail portion RR by using the cylindrical holding portion 47a that holds the main body portion 44 of the inflator 43 from the outer peripheral side and the mounting bolt 48. And a mounting portion 47b for mounting. The mounting portion 47b is formed with a mounting hole 47c into which the mounting bolt 48 is inserted.

As shown in FIGS. 2 to 4, the diffuser 52 has a cylindrical shape made of sheet metal and has a lateral pipe portion 54 whose axial direction is substantially along the front-rear direction of the vehicle V and a tip portion 54 of the lateral pipe portion 54.
and a vertical pipe portion 55 extending downwardly at d. The inner diameter of the lateral pipe portion 54 is set to a size capable of covering the head portion 45 of the inflator 43 so as to cover the gas discharge port 45a of the inflator 43. Further, fixing portions 54a and 54b for attaching and fixing the diffuser 52 to the inflator 43 are formed near the end portion of the lateral pipe portion 54 on the side of the base portion 54c. Each of the fixing portions 54a and 54b is configured to be curved in a substantially U-shaped cross section, and is arranged so as to be fitted between the flange portions 44a, 44b, and 44c of the inflator 43. In the embodiment, this fixed portion 5
4a and 54b are formed by plastic deformation by caulking.

The vertical pipe portion 55 is disposed so as to be substantially orthogonal to the horizontal pipe portion 45, and is closed with the lower end side being formed into a substantially hemispherical shape. The vertical pipe portion 55 has a circular opening near the lower end for ejecting the inflation gas discharged from the inflator 43 into the airbag body 13.
The gas ejection hole 57 and the second gas ejection hole 48 are provided.
Each of the first and second gas ejection holes 57 and 58 is formed such that the angle α between the axial direction of the opening and the central axis of the vertical pipe portion 55 is 45 ° ( (See FIG. 4). In addition, the first and second gas ejection holes 57 and 58 are provided in the lateral pipe portion 5 for the expansion gas G discharged from the inflator 43.
4 is opened substantially along the inflow direction, and in the diffuser 52 of the embodiment, it is opened along the front-rear direction DV of the vehicle V (see FIG. 3). In the case of the embodiment, the first and second gas ejection holes 57 and 58
And the axial direction D2 of the lateral tube portion 54,
As shown in FIG. 3, they are arranged with a deviation of θ with respect to the central axis of the vertical pipe portion 56. In the case of the embodiment, θ
Is set to 12.2 °.

The first gas ejection hole 57 is formed in the front expansion shield portion 1.
The expansion gas G is ejected to the 7A side, and is disposed on the side of the base portion 54c of the lateral pipe portion 54 on the front side of the vehicle V. The second gas ejection hole 58 is for ejecting the inflation gas G toward the rear side expansion shield portion 17B side, and is disposed on the side of the lateral pipe portion 54, which is on the rear side of the vehicle V, away from the base portion 54c. There is. The opening area A of the first gas ejection hole 57 is set larger than the opening area B of the second gas ejection hole 58. In the embodiment, the opening area A of the first gas ejection hole 57 and the second area
The opening area B of the gas ejection hole 58 is set so that A: B = 2: 1.

Further, in the embodiment, the lower end of the vertical inflating portion 55 is near the communicating portion between the gas inlet portion 15 and the gas supply passage portion 21 as shown in FIG.
When the vehicle is mounted on the vehicle V, it is arranged at a position where it does not interfere with the folded portion of the airbag 12. In addition, at the lower end of the vertical inflatable portion 55, the inflation gas G ejected from the first and second gas ejection holes 57 and 58 has a corner portion of the peripheral edge joint portion 29 in the airbag body 13 with the inner tube 36 interposed. 29b and 29b (peripheral joint portion 29 arranged near the communication portion between the gas inlet portion 15 and the gas supply passage portion 21)
It is set at a position where it does not directly hit the part 29b).

In the vicinity of the lower end of the vertical pipe portion 55, as shown in FIG. 3, one gas auxiliary ejection hole opened in a circular shape is formed at a position on the inner side I of the vehicle which is substantially orthogonal to the longitudinal direction DV of the vehicle V. 59 are formed. This gas auxiliary ejection hole 59 is
It is arranged to secure the amount of expansion gas ejected from the diffuser 52, and the opening area C is set smaller than the opening areas A and B of the first and second gas ejection holes. In the embodiment, the opening area A of the first gas ejection hole 57,
The opening area B of the second gas ejection hole 58 and the opening area C of the gas auxiliary ejection hole 59 are set so that A: B: C = 6: 3: 2. In addition, the gas auxiliary ejection hole 59
Although not shown, the opening is formed so that the angle between the axial direction of the opening and the central axis of the vertical tube portion 55 is 45 °.

In the embodiment, the first gas ejection hole 5
7 and the opening area B of the second gas ejection hole 58.
Is a front-side inflation shield portion 17A of the airbag body 13.
B / a> B / A with respect to the capacity a of the gas inflow portion 19 and the capacity b of the gas inflow portion 19 of the rear expansion shield 17B.
It is set so as to satisfy the formula of. In the case of the embodiment, since both a and b are set to 16.5 L, the opening area A of the first gas ejection hole 57 and the opening area B of the second gas ejection hole 58 are calculated by the above formula. Will be satisfied.

The diffuser 52 of the embodiment is
The inner diameter dimensions of the horizontal pipe portion 54 and the vertical pipe portion 55 are set to φ15 mm, and the opening area of the first gas ejection hole 57 is set to 5 mm.
7 mm ² (opening diameter: φ8.5 mm), second gas ejection hole 5
The opening area of No. 8 is set to 28 mm ² (opening diameter: φ6 mm), and the opening area of the gas auxiliary ejection holes 59 is set to 20 mm ² (opening diameter: φ5 mm). In addition, the diffuser 52 of the embodiment has a vertical pipe portion 55 in the horizontal pipe portion 54.
The length L1 of the linear portion 54e in the vicinity is set to 70 mm, and the distance from the central axis of the horizontal pipe portion 54 to the lower end of the vertical pipe portion 50 provided with the first and second gas ejection holes 57 and 58 ( The substantial length dimension L2 of the vertical pipe portion 55 is set to 35 mm, and the radius of curvature R of the central axis at the connecting portion between the horizontal pipe portion 54 and the vertical pipe portion 55 is set to 20 mm (FIG. 3).
・ See 4).

Next, the mounting of the airbag apparatus M on the vehicle V will be described. First, the inner tube 36 is inserted into the air bag body 13 to manufacture the air bag 12, and the air bag 12 is flatly deployed, and then the mountain fold is sequentially performed as shown by a dashed line in FIG. Insert the fold C between the fold and the valley fold, and lower edge 13 of the airbag body 13
The bellows is folded so that the side b approaches the side of the upper edge 13a. After the folding, a rupturable tape (not shown) for preventing collapse is used to wrap the airbag 12 at a predetermined position and the mounting brackets 40 are attached to the respective attachment portions 28. In addition, the gas inlet port 15 is provided with the clamp 50 in advance.

Then, the diffuser 52 is attached to the inflator 43. First, the head portion 45 of the inflator 43 is inserted from the base side of the horizontal tubular portion 54 in the diffuser 52, and a predetermined portion of the horizontal tubular portion 54 is caulked to form the fixed portion 54a between the flange portions 44a and 44b. ,
The fixing portion 54b is formed between the flange portions 44b and 44c, and the inflator 43 and the diffuser 52 are assembled. The mounting brackets 47 may be attached to the inflator body 44 in advance,
After mounting the diffuser 52, the mounting brackets 47, 47 may be mounted on the inflator body 44.

Then, the gas inlet portion 15 of the airbag main body 13 which has the clamp 50 exteriorly mounted together with the mounting portion 37 of the inner tube 36 is exteriorly mounted on the diffuser 52 to connect the diffuser 52 and the airbag 12 to each other. Then, the airbag assembly is formed.

Thereafter, the mounting brackets 40 and 47 are arranged at predetermined positions on the inner panel 2 and the bolts 41 and 48 are attached.
Stop and attach the airbag assembly to the body 1. Next, a lead wire (not shown) extending from a predetermined control device for operating the inflator is connected to the inflator 43, and the pillar garnish 4 and the roof head lining 5 are connected.
Attached to the body 1, and further the pillar garnish 6
・ If 7/8 is attached to the body 1, the airbag device M
Can be mounted on the vehicle V.

If the inflator 43 is actuated after the airbag device M is mounted on the vehicle V, the inflator 43
As shown by the chain double-dashed line in FIG.
The gas flows from the gas inlet portion 15 through the gas supply passage portion 21 to the front side and the rear side. Furthermore, the expansion gas G flows downward from the gas supply passage portion 21, and the expansion shield portion 17 begins to expand while canceling the folding. And the airbag 12
1 breaks the tape (not shown) and further pushes open the airbag cover 10 on the lower edge side of the pillar garnish 4 and the roof head lining 5 to project downward,
As indicated by the chain double-dashed line, the windows W1, W2, W3, the intermediate pillar portions P1, P2, and the rear pillar portion RP are greatly expanded and inflated so as to cover the inside of the vehicle.

In the airbag apparatus M of the embodiment, the opening area A of the first gas ejection hole 57 and the opening area B of the second gas ejection hole 58 formed near the lower end of the vertical pipe portion 55 of the diffuser 52 are set. Is the capacity a of the gas inflow portion 19 of the front inflation shield portion 17A of the airbag body 13.
And the capacity b of the gas inflow portion 19 of the rear expansion shield portion 17B
And so that the formula of b / a> B / A is satisfied,
It is set. Therefore, the inflation gas G discharged from the inflator 43 is transferred to the front inflation shield portion 17A on the side close to the base portion 54c side of the lateral pipe portion 54 with the gas inlet port 15 of the airbag body 13 as a boundary, Pipe part 5
Rear expansion shield portion 17 on the side away from the base portion 54c of No. 4
B and B can be made to flow into the airbag main body 13 so as to be inflated and inflated at substantially the same inflation completion time.

That is, in the airbag apparatus M of the embodiment, the inflator 43 is arranged on the upper edge side of the window inside the vehicle V and the vehicle V of the airbag 12 is arranged.
Since the gas inlet port 15 is disposed on the side of the upper edge 13a of the substantially middle portion in the front-back direction, the diffuser 52 connected to the inflator 43 is connected to the airbag 1
It is necessary to bend and arrange it on the 2nd side downward. Therefore, the diffuser 52 of the embodiment bends downward at the tip of the horizontal pipe portion 54 and the horizontal pipe portion 54 that is arranged substantially along the front-rear direction of the vehicle V so as to extend substantially along the axial direction of the inflator 43. And a vertical pipe portion 55 extending in such a manner.

However, in the diffuser 52 having the above structure, if the opening area of the first gas ejection hole 57 and the opening area of the second gas ejection hole 58 are set to be substantially the same, ejection from the second gas ejection hole 58 will be performed. The present inventors have found that the amount of expansion gas ejected is greater than the amount of expansion gas ejected from the first gas ejection hole 57. This is the length dimension L2 of the vertical pipe portion 55 in the diffuser 52.
Is shorter than the length dimension L1 of the straight portion 54e of the horizontal pipe portion 54 and the inner diameter dimension of the vertical pipe portion 55, and the vertical pipe portion 55 is
Near the lower end of the first and second gas ejection holes 57, 58
Are arranged so as to be substantially along the inflow direction of the expansion gas G in the lateral pipe portion 54, and therefore, for expansion per unit area of the second gas ejection holes 58 on the side away from the lateral pipe portion 54. It is estimated that this is because the gas ejection amount is larger than the expansion gas ejection amount per unit area in the first gas ejection hole 57 on the base side of the lateral pipe portion 54.

Therefore, in the airbag apparatus M of the embodiment, the front side inflation shield portion 17A of the airbag body 13 is provided.
B / a> B / A with respect to the capacity a of the gas inflow portion 19 and the capacity b of the gas inflow portion 19 of the rear expansion shield 17B.
Using the diffuser 52 in which the first and second gas ejection holes 57 and 58 having the set opening areas A and B are arranged on the lower end side of the vertical pipe portion 55 so as to satisfy the formula did. Therefore, when the airbag 12 is deployed and inflated, the direction is opposite to the flow direction of the inflation gas G in the lateral tube portion 54, and the front side is the base portion 54c side of the lateral tube portion 54, which tends to delay the completion time of inflation. The expansion completion time of the expansion shield 17A can be shortened, and the expansion shield 17A can be expanded and expanded so that the expansion completion time is substantially equal to that of the rear expansion shield 17B.

Therefore, in the airbag apparatus M of the embodiment, the inflator 43 is arranged on the upper edge side of the windows W1, W2, W3 on the inside of the vehicle V so that the airbag 12 is provided at a substantially intermediate portion in the front-rear direction. Even if the gas inlet port 15 is provided, the portion 17A on the front side of the gas inlet port 15 of the airbag 12 and the portion 17B on the rear side of the gas inlet portion 15 are made to have substantially the same inflation completion time. Can be expanded and inflated.

In the airbag device M of the embodiment,
The capacity a of the gas inflow portion 19 of the front expansion shield 17A and the capacity b of the gas inflow portion 19 of the rear expansion shield 17B are
The airbag 12 which is set to be substantially the same is described as an example, but, of course, if the first and second gas ejection holes 57 and 58 of the diffuser 52 are set so as to satisfy the above-described mathematical expression, the front side inflation is performed. The volume a of the gas inflow portion 19 in the shield portion 17A and the gas inflow portion 1 in the rear expansion shield portion 17B
The present invention may be applied to an airbag having a configuration in which the capacity b of 9 is different.

Further, in the airbag device M of the embodiment,
In the vicinity of the lower end of the vertical pipe portion 55 of the diffuser 52, the opening area C is set to the first inner side at a position that is the vehicle inner side I substantially orthogonal to the inflow direction (the front-back direction of the vehicle V) of the expansion gas G in the horizontal pipe portion 54. The opening area A of the second gas ejection holes 57, 58
One gas auxiliary ejection hole 59 is set to be smaller than B (see FIG. 3). This gas auxiliary ejection hole 59
Is provided in order to shorten the completion time of inflation of the airbag. Therefore, if the gas auxiliary ejection holes 59 are provided, the airbag can be rapidly deployed and inflated even when used in an airbag having a large capacity. When used for an airbag having a large capacity, if the opening areas of the first and second gas ejection holes 57 and 58 are set to be large respectively,
The amount of expansion gas G ejected from the second gas ejection holes 57 and 58 increases, and the expansion gas G is ejected.
-Airbag body 13 near the second gas ejection holes 57 and 58
There is a possibility that the portion of the non-inflow portion 27 in (1) such as the corner portions 29b and 29b of the peripheral edge joint portion 29 and the lateral joint portion 32A may be greatly damaged. Further, if the gas auxiliary ejection holes are arranged, the first and second gas ejection holes 57 are formed.
・ Even if the design of 58 is not changed, it is possible to deal with airbags with large capacities simply by changing the design of the opening area of the gas auxiliary ejection holes, so it is easy to deal with airbags of different capacities. Can be made. Of course, if this point is not taken into consideration, the gas auxiliary ejection hole may not be provided.

The number of the gas auxiliary ejection holes 59 is not limited to one, and for example, one gas auxiliary ejection hole 59 may be provided at each of the vehicle interior side I and the vehicle exterior side O. One may be arranged only at the position on the outside O of the vehicle. However, in the case where the gas auxiliary ejection hole is arranged at a position on the outer side of the vehicle, the inner panel on the body side is arranged on the vehicle outer side of the airbag where the gas auxiliary ejection hole is arranged. Therefore, since the inflation gas ejected from the gas auxiliary ejection hole does not move so as to inflate other parts of the airbag and may damage the airbag, the gas auxiliary ejection hole is It is desirable to arrange it at a position that is the inside I of the vehicle.

Further, in the airbag device M of the embodiment,
First and second gas ejection holes 57 in the diffuser 52
-58 and the gas auxiliary ejection hole 59 respectively set the angle α between the axial direction of the opening and the central axis of the vertical pipe portion 55 to 4
It is arranged so as to be inclined at 5 °. That is, in the airbag device M of the embodiment, the first
-Second gas ejection holes 57 and 58 and gas auxiliary ejection hole 5
The expansion gas G ejected from 9 is ejected obliquely downward along the axial direction of the opening. Therefore,
As shown in FIG. 6, even when the airbag 12 is used without the inner tube, the inflation gas G ejected from the first and second gas ejection holes 57 and 58 and the gas auxiliary ejection hole 59. However, the inflation gas G can be ejected into the airbag 12 in a state in which the corner portions 29b and 29b of the peripheral edge joint portion 29 of the airbag 12 are not directly contacted with each other and damage is suppressed.

In the diffuser 52 of the embodiment, the lower end side of the vertical pipe portion 55 is closed by forming a substantially hemispherical shape, but the shape of the lower end side of the vertical pipe portion 55 is not limited to this. The vertical tube portions 55A, 55B, 55C having the shapes shown in FIGS. 8A, 8B, 8C may be used.

In the vertical pipe portion 55A shown in FIG. 8A, the lower end side is projected in a substantially conical shape to close it, and the first and second
It is arranged such that the axial direction of the openings of the gas ejection holes 57A and 58A is inclined so that the angle β with the central axis is 45 °. Even when the vertical pipe portion 55B has such a structure, the expansion gas G ejected from the first and second gas ejection holes 57B and 58B is ejected obliquely downward along the axial direction of the opening. It will be.

The vertical tube portion 55B shown in FIG. 8B has a substantially conical recess 55a so that the cross section near the lower end has a substantially W shape.
Is provided and the lower end side is closed, and the first and second gas ejection holes 57B and 58B are arranged in the vicinity of the lower end of the peripheral wall forming the vertical pipe portion 55B. The inclination angle γ of the concave portion 55a is set to 45 ° with respect to the central axis of the vertical pipe portion 55B. A gas auxiliary ejection hole 59B that opens downward is formed near the upper end of the recess 55a. Vertical pipe section 55
Even when B has such a configuration, the inflation gas G ejected from the first and second gas ejection holes 57B and 58B is guided to the inclined inner peripheral surface of the wall portion forming the recess 55a. That is, along this inner peripheral surface, the ink is jetted obliquely downward.

The vertical pipe portion 55C shown in FIG. 8C has its lower end substantially closed, and has first and second gas ejection holes 57C and 58C.
Is disposed at a portion near the lower end of the peripheral wall forming the vertical pipe portion 55C. Further, a gas auxiliary ejection hole 59C opening downward is formed on the lower end side. When the vertical pipe portion 55C has such a configuration, the first
The expansion gas G ejected from the second gas ejection holes 57C and 58C should be ejected toward the front side or the rear side along the opening axis direction of the first and second gas ejection holes 57C and 58C. Becomes

[Brief description of drawings]

FIG. 1 is a schematic front view showing a usage state of a head protection airbag apparatus according to an embodiment of the present invention as viewed from the inside of a vehicle.

FIG. 2 is a partially enlarged cross-sectional view of an inflator installation portion in the airbag device of the same embodiment.

FIG. 3 is a bottom view of the diffuser used in the same embodiment.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a front view showing a state in which the airbag used in the same embodiment is flatly deployed.

FIG. 6 is a schematic view showing a flow state of inflation gas ejected from a diffuser in the airbag apparatus of the same embodiment.

FIG. 7 is a partially enlarged cross-sectional view of an inflator installation portion showing a case where the airbag device of the present invention is applied to an airbag having no inner tube.

FIG. 8 is a cross-sectional view showing the vicinity of a lower end of a vertical pipe portion in a diffuser of another form.

[Explanation of symbols]

11 ... airbags, 15 ... Gas inlet, 17 ... expansion shielding part, 17A ... front expansion shield, 17B ... rear expansion shield, 19 ... Gas inlet, 43 ... Inflator, 52 ... Diffuser, 54 ... Horizontal pipe section, 54c ... Motobu, 54d ... tip, 55 / 55A / 55B / 55C ... Vertical pipe section, 57 / 57A / 57B / 57C ... 1st gas ejection hole, 58 / 58A / 58B / 58C ... second gas ejection hole, 59 / 59B / 59C ... Gas auxiliary ejection holes, G ... expansion gas, V ... vehicle, W1, W2, W3 ... windows, M: Head protection airbag device.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3D054 AA02 AA03 AA04 AA07 AA18                       BB21 DD40 FF20

Claims (3)

[Claims] 1. An airbag, which is folded and housed on an upper edge side of a window in a vehicle interior of a vehicle and expands downward so as to cover the vehicle interior of the window when an inflating gas flows in, and the airbag. And an inflator for supplying an inflation gas, the inflator being disposed on an upper edge side of a window inside a vehicle, and the airbag allowing the inflation gas to flow thereinto. An inflating shield portion that shields the vehicle interior side of the window, and a portion that inflates so as to separate the vehicle outer wall portion from the vehicle outer side wall portion, and an upper edge side at a substantially intermediate portion in the front-rear direction of the airbag so as to project upward. A head protection airbag device configured to include one gas inlet port that is disposed in the inflator and allows the inflation gas from the inflator to flow into the expansion shield unit. Is connected so that the expansion gas from the inflator can flow into the expansion shield, and a lateral pipe portion whose axial direction is substantially along the front-rear direction of the vehicle, and a lateral pipe portion of the lateral pipe portion. A diffuser configured to include a vertical pipe portion that is bent downward at a tip is provided, and an expansion gas discharged from the inflator is provided near a lower end of the vertical pipe portion of the diffuser. 2 substantially along the inflow direction in the lateral pipe portion, and is open to the expansion shield portion side on the front side of the gas inlet portion and the expansion shield portion side on the rear side of the gas inlet portion 2 Two gas ejection holes are formed, and the opening area A of the first gas ejection hole disposed on the base side of the lateral pipe portion in the two gas ejection holes and the lateral pipe in the two gas ejection holes Away from the base side of the department And the opening area B of the second gas ejection hole disposed in the airbag is the side close to the base side of the lateral pipe section with the gas inlet section as a boundary in the airbag. When the volume of the inflation gas flowing into the portion is a, and the volume of the inflation gas flowing into the portion of the expansion shield portion on the side away from the base side of the lateral tube portion is b, b / a A head protection airbag device characterized by being set within a range of a mathematical formula represented by> B / A. 2. In the airbag, a volume into which an inflation gas is introduced at a portion of the expansion shield portion that is a side close to a base portion side of the lateral pipe portion and a distance from the base portion side of the lateral pipe portion. 2. The head protection airbag device according to claim 1, wherein the volume of the inflation gas flowing into the portion of the inflation shield portion on the open side is set to be substantially equal to each other. 3. An opening area is provided near the lower end of the vertical pipe portion of the diffuser at least on one side in a direction substantially orthogonal to the inflow direction of the expansion gas in the horizontal pipe portion, The head protection airbag device according to claim 1 or 2, wherein a gas auxiliary ejection hole that is set smaller than an opening area of the second gas ejection hole is formed.