JP2003291769A - Airbag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a coupling portion to an airbag body in a tether from being damaged, by simple constitution. <P>SOLUTION: An airbag 41 is provided with the flexible bag-like airbag main body 42 for constituting an outer circumferential wall when inflation is finished, and the tether 56. The tether 56 comprises a flexible band-like cloth material 60, and regulates a shape of the airbag main body 42 when the inflation is finished, as a coupling end 57 for coupling a longitudinal-directional end part to the air bag main body 42. The coupling end 57 of the tether is provided with a folded part 58 formed by folding an edge 64 of the cloth material 60 for the tether to impart a fold C along a longitudinal direction Y of the tether, in at least one edge 64 side in a width direction X of the tether 56. The folded part 58 of the tether is coupled to the airbag main body 42 under the condition where the cloth material 60 is overlapped to be integrated. <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 used in an airbag device mounted on a vehicle, and in particular,
The present invention relates to an airbag provided with a tether for controlling the thickness and shape of the airbag when the inflation is completed.

[0002]

2. Description of the Related Art Conventionally, as an air bag of an air bag device, there has been a structure shown in Japanese Patent Laid-Open No. 2001-114060. In this airbag device, the airbag includes the flexible airbag body that constitutes the outer peripheral wall of the airbag, and the strip-shaped tether made of a flexible cloth material.

The tether regulates the shape of the airbag body at the time of completion of inflation by using both ends in the longitudinal direction as joining ends for joining the airbag body. That is, the tether of the above-mentioned publication is arranged in order to regulate the thickness of the airbag body and maintain the plate shape of the airbag body.

However, since a large tension acts on the tether when the inflation of the airbag body is completed, the connecting end of the tether is easily damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an airbag capable of preventing damage to the joining portion of the tether to the airbag body with a simple structure. .

[0006]

SUMMARY OF THE INVENTION An airbag according to the present invention comprises a flexible bag-shaped airbag main body which constitutes an outer peripheral wall at the time of completion of inflation, and an airbag main body having an end portion in the longitudinal direction. A tether made of a flexible band-shaped cloth material capable of restricting the shape of the airbag body at the time of completion of inflation as a joining end to be joined to The tether is provided with a folding portion formed by folding the edge of the cloth material for the tether so that a fold along the length direction of the tether is formed on at least one edge side in the width direction of the tether. The part is joined to the airbag body in a state where the cloth materials are overlapped and integrated.

In the airbag according to the present invention, at least one edge side in the tether width direction at the joint end of the tether, the tether applies any one of the plurality of layers in which the folded portions are overlapped to each other as a reinforcement (buffer) patch cloth. It is used as in and bonded to the airbag body. Therefore, even when a strong impact is applied to the edge side end portion of the joining portion of the tether joining end with the airbag body when the airbag is inflated, the impact is alleviated and damage to the tether is suppressed.

In particular, the folded portion folds the edge of the tether in the width direction, and does not fold the edge of the tether in the length direction to join the airbag body. Therefore, when a tensile force is applied to the tether, stress concentration is likely to occur particularly in the edge side end portion in the width direction of the tether in the area of the joining portion of the tether to the airbag body. However, in the present invention, the folded portion is formed by folding the edge side in the width direction of the tether. Therefore, it is possible to arrange the folding portion along the entire length along the length direction of the tether, so that the stress concentration acting on the edge side end portion of the joining portion of the tether with the airbag body can be reduced. The particles can be dispersed according to the number of stacked layers (number of sheets). As a result, the tether of the present invention can further prevent damage to the joining portion of the tether with the airbag body, as compared with the case where the lengthwise edge of the tether is folded and joined to the airbag body. .

The structure for preventing damage to the connecting portion of the tether with the airbag body can be easily formed by simply folding the widthwise edge of the tether.

Therefore, in the airbag according to the present invention, it is possible to prevent damage to the joining portion of the tether with the airbag body with a simple structure.

The strip-shaped tether folds may be provided at both edges in the width direction of the tether, but at both edges in the width direction of the tether, one edge is larger than the other edge. When receiving a large tension, a folding portion may be provided only on one edge side thereof to join the tether to the airbag body side.

If a flexible reinforcing cloth is interposed between the folded portion of the tether and the joining portion of the folded portion of the airbag body, as described in claim 2, The reinforcing cloth serves as a cushioning material for the airbag body, and it is possible to prevent damage to the joining portion of the airbag body with the tether.

Further, in this case, when the reinforcing cloth is integrated with the cloth material for the tether as in claim 3, the reinforcing cloth for the tether is different from the case where the reinforcing cloth is separate from the cloth material for the tether. Arrangement work such as positioning of the cloth material and the reinforcing cloth on the airbag body becomes easy. That is, if the reinforcing cloth is separate from the tether cloth material, it may be largely disengaged or dropped from between the tether cloth material and the airbag body.
However, if the reinforcing cloth is integrated with the tether cloth material, it can be prevented from being largely disengaged or dropped from between the tether cloth material and the airbag body.

Further, when the reinforcing cloth is provided, the reinforcing cloth is connected to the airbag main body by providing a peripheral connecting portion whose outer peripheral edge is connected to the airbag main body. However, if it is arranged so as to surround the edge-side end portion located at the folded portion at the joining portion of the tether with the airbag body, the following actions and effects can be obtained.

That is, with such a structure, the tensile force of the entire airbag body at the time of inflation is difficult to propagate in the area of the airbag body surrounded by the reinforcing cloth due to the peripheral edge joint portion. Therefore, it is difficult for the tensile force of the entire airbag body to be transmitted to the edge side end portion of the joining portion with the airbag body in the tether, and the folding portion of the tether located at the edge side end portion is joined to the airbag body. Strength is improved.

Further, in this case, when the connecting portion of the tether with the airbag body and the peripheral connecting portion of the reinforcing cloth are formed by suturing the sutures, Since the connecting portion can be formed by a continuous operation without cutting a suture, the connecting operation of the reinforcing cloth and the tether to the airbag body can be easily performed.

[0017]

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 FIGS. 1 to 4, an airbag 41 of the embodiment is used in an airbag device S for knee protection. ing. This knee protection airbag device S is shown in FIG.
As shown in FIGS. 4 to 4, it is arranged below the steering column 3 on the vehicle front side of the driver MD (occupant M) so as to protect the knee K of the driver MD.

The terms up, down, left, right, and front and rear in this specification correspond to the up, down, left, and right of the vehicle when the knee protection airbag device S is mounted on the vehicle.

As shown in FIG. 1, the steering column 3 includes a column body 4 connected to the steering wheel 1 and a column cover 8 arranged to cover the column body 4 below the steering wheel 1. , And are configured. The column body 4 is the main shaft 5
And the column tube 6 covering the periphery of the main shaft 5.
And are provided.

The column cover 8 is made of a synthetic resin having a substantially rectangular tube shape and covers the column body 4 so as to cover the column body 4.
Are arranged along the axial direction of. The cover 8 is an instrument panel (hereinafter abbreviated as “instrument panel”) 10
The lower surface 8a of the portion projecting from is formed in a substantially rectangular shape, and is formed in a curved shape that rises backward in the vehicle front-rear direction.

The knee protection airbag device S comprises a folded airbag 41, an inflator 32 for supplying inflation gas to the airbag 41, and a folded airbag 41.
And a inflator 32, and a case 12 that is open on the vehicle rear side, and an airbag cover 18 that covers the vehicle rear side of the case 12.

As shown in FIGS. 1 to 3, the case 12 is made of sheet metal, has a box shape having an opening 12e on the rear side of the vehicle, and is arranged on the lower side of the steering column 3. Walls 12a of the case 12 facing each other in the vertical direction
A plurality of hooks 14 having a substantially U-shaped cross section are fixed to the outer peripheral surface of 12b. Further, the case 12 is formed with an insertion hole 12c through which an end portion of a main body 33 of the inflator 32, which will be described later, can be inserted, and an insertion hole 12d for inserting a bolt 34c of the inflator 32, which will be described later, ( (See FIG. 3). The case 12 is connected and fixed to an instrument panel reinforcement (not shown) arranged near the column body 4 by using a bracket (not shown).

The air bag cover 18 is made of a thermoplastic elastomer such as polyolefin, and is used for the case 1
It is configured so that it can cover the rear side of the vehicle 2.

The airbag cover 18 is a lower panel 10b on the peripheral edge of the column cover 8 in the instrument panel 10.
The column cover 8 is disposed on the side and covers the lower peripheral edge of the column cover 8 protruding from the instrument panel 10. The instrument panel 10 is composed of an upper panel 10a and a lower panel 10b. The cover 18 includes a door portion 30 that covers the opening 12e of the case 12 and a general portion 20 that is arranged around the door portion 30.

The door portion 30 is formed slightly larger than the opening 12e of the case, and is formed in a substantially rectangular plate shape that covers the opening 12e. The door portion 30 has a hinge portion 29, which serves as a center of rotation when the door portion 30 is opened, arranged at the lower end thereof, and a thin portion to be broken 28 is formed at an inverted U-shaped portion of the outer peripheral edge excluding the hinge portion 29. It is arranged.

At a portion of the general portion 20 near the peripheral edge of the door portion 30, four side wall portions 23, 24, which are arranged on the outer peripheral side of the case 12 so as to project to the front side of the vehicle.
25 and 26 are provided. Then, the upper side wall part 23 arranged on the upper side of the case 12 and the lower side wall part 24 arranged on the lower side of the case 12 serve as a connecting portion for connecting the airbag cover 18 to the case 12. .
The upper side wall portion 23 and the lower side wall portion 24 respectively include the case 1
Locking holes 23a and 24 whose peripheral edges are locked to the hook 14 of No. 2
a is formed.

At a predetermined position in the general section 20,
Mounting legs 21 for mounting and fixing the airbag cover 18 to the lower panel 10b are formed so as to extend toward the vehicle front side. This mounting leg portion 21 is used for the lower panel 10.
It is locked to the peripheral edge of the locking hole 10e of b. The lower panel 10b includes a storage recess 10c for storing the case 12. A flange portion 10d is provided on the periphery of the storage recess 10c.
And a locking hole 10e is formed in the flange portion 10d (see FIG. 3). A rib 21a is formed at the base of the mounting leg portion 21. This rib 21a is
When the mounting leg portion 21 is locked in the locking hole 10e, it abuts the flange portion 10d of the lower panel 10b to support the general portion 20.

As shown in FIGS. 1 to 3, the inflator 32 is of a cylinder type in which the axial direction is arranged along the lateral direction of the vehicle. The inflator 32 includes a substantially cylindrical main body 33 and a diffuser 34. Body 3
A plurality of gas discharge ports 33 a are formed on one end side of 3. A connector 38 to which a lead wire 39 for inputting an operation signal is connected is connected to the other end of the main body 33. The diffuser 34 includes a holding cylinder portion 34a made of a substantially cylindrical sheet metal capable of covering the main body 33, and a holding cylinder portion 34a.
Plural (two in the embodiment) bolts 34c protruding from the
And consists of. The holding cylinder portion 34a opens a plurality of gas outlets 34b capable of flowing out the inflation gas discharged from the gas discharge port 33a of the main body 33, on the surface of the holding cylinder portion 34a mounted on the vehicle on the vehicle rear side. ing.

It is to be noted that the inflator 32 is provided with an airbag operating circuit mounted on the vehicle through a lead wire 39 together with an airbag device (not shown) mounted on the steering wheel 1 when a frontal collision of the vehicle is detected. Then, the operation signal is input.

As shown in FIGS. 5 and 6, the air bag 41 includes an air bag main body 42 which constitutes a bag-shaped outer peripheral wall, and two tethers 56 and 5 arranged in the air bag main body 42.
6 is provided.

The airbag body 42 is formed of one piece of woven fabric (cloth material 43 for the airbag body) made of flexible polyester or polyamide thread, and as shown in FIGS. The shape at the time of completion of expansion and expansion is a substantially fan plate shape with a narrower bottom. The airbag body 42 has a lower end 42.
The a-side inflator 32 is housed in the mounting portion 45, and the inflating portion 44 is disposed above the mounting portion 45 and has a lateral width larger than that of the mounting portion 45.

The mounting portion 45 is a portion on the upstream side of the inflation gas G, and when the inflation and inflation of the airbag 41 is completed,
The inflator 3 is housed in the case 12
2 is used to serve as a portion held by the case 12.

The inflating portion 44 is located on the downstream side of the inflating gas G, and when the airbag 41 is inflated and inflated, the inflatable portion 44 projects from the case opening 12e to inflate and inflate to protect the knees of the driver MD. Further, when the inflation of the airbag 41 is completed, the inflatable portion 44 covers from the vicinity of the opening 12e of the case 12 to the vicinity of the upper end 8b on the column cover lower surface 8a side.

The airbag 41 is composed of the airbag body 4
The cloth material 43 for an airbag body made of one piece of woven fabric that constitutes the outer peripheral wall of 2 is folded at the portion which becomes the lower end 42a of the airbag body 42, and the edges of the opposing portions are folded together by the suture thread 54. It is formed by stitching. The airbag body 42 has a substantially fan shape.
The passenger side wall portion 47 on the D side and the vehicle body side wall portion 48 on the column cover 8 side are provided. In addition, suture thread 5
Reference numeral 4 is formed of a synthetic resin multifilament such as polyester or polyamide.

Mounting portion 4 on the lower side of the vehicle body side wall portion 48
Two insertion holes 45a, 45a and one insertion hole 45b are formed in the region of 5. Insertion holes 45a ・ 45a
Is for inserting each bolt 34c of the inflator 32, and the insertion hole 45b is for inserting the main body 33 of the inflator 32.

In the inflating portion 44 of the air bag body 42, band-shaped tethers 56, 56 are arranged in two steps in the vertical direction. When the inflation of the airbag 41 is completed, each of the tethers 56 has a central portion 44.
It is arranged so that the plate shape of the airbag body 42 can be maintained without increasing the wall thickness in the vicinity of a. Therefore, the tethers 56, 56 are arranged near the central portion 44a of the inflating portion 44.

Each end of each tether 56 in the lengthwise direction Y is a connecting end 57 which is connected to the passenger side wall portion 47 and the vehicle body side wall portion 48 of the airbag body 42. Then, each tether 56 defines the distance between the passenger side wall portion 47 and the vehicle body side wall portion 48 in the airbag main body 42 at the time of completion of inflation by the length dimension between the coupling ends 57, 57. . Then, the folded portions 58 are respectively provided on both edges in the left-right direction which is orthogonal to the length direction Y and becomes the width direction X.
Are formed (see FIG. 7).

Each folding portion 58 has a tether cloth material 6 which will be described later.
It is a part where two edges 60 of the cloth material 60 are stacked by folding the edge 64 in the left-right direction of 0, and is extended to the part of the coupling end 57.
It is arranged. Further, in the case of the embodiment, each tether 5
Each of 6 is formed of two tether cloth materials 60 that are joined at the intermediate portion of the joining ends 57, 57.

Further, in the case of the embodiment, a substantially rectangular plate-shaped reinforcing cloth 73 is interposed between the tether 56 and the airbag main body 42 on the left and right edges in the width direction X, respectively. There is.

The cloth material 60 for each tether is the airbag body 4
Like No. 2, it is made of flexible woven fabric such as polyester or polyamide. In the case of the embodiment, as shown in FIGS. 5 to 8, the connecting piece portion 61 and the reinforcing cloth 7 are provided.
3, and two reinforcing portions 69, 69, which form part 3, are provided. The connection piece portion 61 has a length dimension corresponding to the tether 56 to be arranged and has a rectangular plate shape extending in the left-right direction which is the width direction X of the tether 56 when flatly expanded, as shown in FIG. The side edges 64 in the left-right direction are folded along the lengthwise direction Y of the tether 56, and the edges 6 are folded.
The folded portion 58 is formed by 4 and the overlapping portion 65 that overlaps the edge portion 64.

The tether cloth material 60 is used for the tether 5
6, one end portion along the length direction Y of 6 is a tether side end portion 62.
The end portions 62 are joined together to form the tether 56. In addition, each cloth material 60 has the other end portion along the length direction Y of the tether 56 as the body side end portion 63, which is joined to the passenger side wall portion 47 or the vehicle body side wall portion 48 of the airbag body 42. I am trying.

Each of the reinforcing portions 69 has a substantially rectangular plate shape when the cloth material 60 is flatly developed, and protrudes in the left-right direction from the edge portion 64 of the connecting piece portion 61.
The connecting piece portion 61 is formed so as to be displaced from the main body side end portion 63 in the length direction Y of the tether 56 and project from the connecting piece portion 61. Edge portions 64 of each reinforcing portion 69 and connecting piece portion 61
Along the fold C, the tether-side end 62 is
A cut 67 is formed to enter from the side. The size of each reinforcing portion 69 is larger than the width dimension W0 of the folded portion 58, and is formed in a substantially quadrangular shape having a side length dimension (outer dimension) W1 which is about 2 to 3 times the width dimension W0. . The length of the cut 67 is set so that the tip portion 67a of the cloth material 60 in a flattened state is located near the extension line of the main body side joint portion 71 formed by the suture thread 54, which will be described later. . In addition, the main body side connection portion 71 is formed by the suture thread 54.
Is a site that is bound by the binding end 5 of the tether 56.
7 is a connecting portion to the airbag main body 42, more specifically, a connecting portion to the airbag main body 42 at the main body side end portion 63 of the connecting piece portion 61.

To connect the tether cloth material 60 to the airbag body cloth material 43, first, from the state where each cloth material 60 is flatly developed, to the left and right edge portions 64 side of the connecting piece portion 61, A crease C is provided, and the edge portion 64 is folded so as to overlap the overlapping portion 65 to form a folded portion 58, and each reinforcing portion 69 is projected from the folded portion 58 of the connection piece portion 61. Fold it back at the position of the break 67 (see FIGS. 8 and 9). Then, while applying each reinforcing cloth 69 to a predetermined portion of the airbag body cloth material 43 (a predetermined portion on the inner peripheral surface side of the airbag main body 42), the main body side end portion 63 of the connecting piece portion 61 is connected to the airbag. It is applied to a predetermined portion of the body cloth material 43.

At this time, if the tether-side end portion 62 side of the connecting piece portion 61 is raised from the main body cloth material 43, as shown in FIG.
・ The state becomes 11. In this state, the left and right edges 63 of the body-side end 63 of the connecting piece 61 are arranged.
In a, the edge portion 64 of the folded portion 58 does not directly contact the airbag body cloth material 43, and the reinforcing cloth 73 (reinforcement portion 69) is interposed between the edge portion 64 and the cloth material 43. It will be. By the way, if the tether side end portion 62 side of the connecting piece portion 61 is disposed substantially perpendicular to the main body side end portion 63 by further raising, the state of the tether cloth material 60 will be the airbag body. The state when the expansion of 42 is completed is substantially the same.

After the tether cloth material 60 having the folded portion 58 is arranged on the airbag body cloth material 43, the connecting piece is operated by the operation of the industrial sewing machine using the suture thread 54. The main body side end portion 63 of the portion 61 is sewn and joined to the main body cloth material 43. At this time, at the body side end portion 63, a connecting portion 71 to the body cloth material 43 by the suture thread 54 is linearly formed along the left-right direction of the airbag 42. Then, the folded portions 58 near the left and right edge-side end portions 71 a of the joining portion 71 are joined to the body cloth material 43 with the reinforcing cloth 73 interposed.

At the time of suturing, the suture thread 54
The outer peripheral edge of the reinforcing cloth 73 is sewn and joined to the main body cloth material 43. The outer peripheral edge of the reinforcing cloth 73 is connected to the main body cloth material 43 by a peripheral edge connecting portion 75. The peripheral edge coupling portion 75 is formed so as to surround the edge-side end portion 71a by approximately a half circumference around the edge-side edge portion 71a of the main body-side coupling portion 71 in the main body-side end portion 63. The locus for half the circumference of the peripheral edge joint portion 75 is a substantially C-shape that encloses the end portion 71a on the side away from the main body side joint portion 71.

Further, in the case of the embodiment, the connecting portion 77 is provided without cutting the suture thread 54, and the edge side end portion 71a of the main body side joint portion 71 and the peripheral edge joint portion 75 are continuously stitched together. Is forming. In the case of the embodiment, the connecting portion 77 linearly extends the sewn portion of the suture thread 54 in the direction away from the tether-side end portion 62 of the connecting piece portion 61 from the end portion 71 a, and the peripheral edge joint portion 75. Connected to.

Then, the connecting piece portion 61 of the tether cloth material 60.
After the reinforcing member 69 and the reinforcing portion 69 are joined to the airbag body cloth material 43, the airbag body cloth material 43 is folded at a portion which will be the lower end 42a of the airbag body 42, and the corresponding tether of the connecting piece portion 61. The side ends 62 are mutually connected by the suture thread 54,
Each tether 56 is formed by stitching, and further,
The airbag 41 can be manufactured by suturing the overlapping portions of the outer peripheral edge of the main body cloth material 43 with the suture thread 54.

When the outer peripheral edge of the cloth material 43 for the main body is sewn, the unsewn portion 42b (see FIG. 5) is left, and the inflator 32 is housed in the airbag 41 from the portion 42b, and each bolt 34c is inserted. Is projected from the insertion hole 45a, and the base portion side of the inflator body 33 is projected from the insertion hole 45b, and then the unsewn portion 42b of the airbag body 42 is sewn.

When assembling the thus manufactured airbag 41 into the airbag apparatus S, first, the airbag 4 is assembled.
1 is folded, and then the airbag 41 is wrapped with a rupturable wrapping film (not shown) for preventing collapse. At this time, the bolt 34c of the inflator 32 and the end portion of the main body 33 protruding from the insertion holes 45a and 45b are
Leave it protruding from the wrapping film.

Then, each bolt 3 of the inflator 32
4c is projected from the insertion hole 12d of the case 12, and the end portion of the inflator body 33 is projected from the insertion hole 12c of the case 12, so that the inflator 3
2 together with folded airbag 41, case 1
The inflator 32 and the airbag 41 can be housed in the case 12 and attached to the case 12 by housing them in the housing 2 and fastening the nuts 36 to the bolts 34c.

Thereafter, the bracket (not shown) of the case 12 is attached to the instrument panel reinforcement of the vehicle to which the upper panel 10a and the lower panel 10b are already attached, and the connector 38 to which the lead wire 39 is connected is connected to the main body 33 of the inflator 32. Then, push the airbag cover 18 toward the front side of the vehicle to remove the mounting leg portions 2
1 is inserted and locked in the locking hole 10e of the lower panel 10b, and each locking hole 2 of the upper side wall 23 and the lower side wall 24
When the hook 14 of the case 12 is locked to the 3a and 24a and the airbag cover 18 is connected to the case 12, the airbag device S can be mounted on the vehicle.

After the airbag apparatus S is mounted on the vehicle, if an actuation signal is input to the main body 33 of the inflator 32 via the lead wire 39, the inflation gas G is discharged from the gas discharge port 33a of the inflator 32, The expansion gas G
The gas flows into the inflatable portion 44 of the airbag body 42 via the gas outlet 34b of the diffuser 34. Then, the airbag main body 42 expands to break the wrapping film (not shown), presses the door portion 30 of the airbag cover 18 to break the planned breaking portion 28, and the hinge portion 29 is used as the center of rotation for the door portion. 30 will be opened downward. As a result, the airbag body 42 (the airbag 4
In 1), as indicated by the chain double-dashed line in FIGS. 1 and 4, along the lower surface 8a of the column cover, it is greatly expanded and expanded upward.

In the airbag 41 of the embodiment,
The width direction X of the tether 56 at the joining end 57 of the tether 56
On the edge side of the, the tether 56 is connected to the airbag body 42 by using one of the overlapping portions 64 and 65 of the folded portion 58 as a reinforcing (buffering) patch cloth. Therefore, when the airbag 41 is inflated, even if a strong impact is applied to the edge-side end portion 71a of the joining portion 71 of the tether joining end 57 with the airbag body 42, the impact is relieved and damage to the tether 56 is suppressed. To be

In particular, the folded portion 58 folds the edge of the tether 56 in the width direction X and the tether 56 in the length direction Y.
The edge of is not to be joined to the airbag body 42 by folding. Therefore, when a tensile force acts on the tether 56,
Connection part 7 with airbag body 42 in tether 56
In the area No. 1, stress concentration is likely to occur particularly at the edge end 71a of the tether 56 in the width direction X. However, in the embodiment, the edge 64 side of the tether 56 in the width direction X is folded,
A folded portion 58 is formed. Therefore, the folded portion 58
Can be arranged over the entire length of the tether 56 in the longitudinal direction Y, and the stress concentration acting on the edge side end portion 71a of the joining portion 71 of the tether 56 with the airbag body 42 can be reduced. It can be dispersed according to the number of layers (number of layers) of the folded portions 64 and 65 of 58. As a result, the tether 56 can further prevent breakage of the joining portion 71 of the tether 56 with the airbag body 42 as compared with the case where the edge of the tether 56 in the length direction Y is folded and joined.

The structure for preventing damage to the connecting portion 71 of the tether 56 with the airbag body 42 is as follows.
Simply fold the widthwise X edge 64 of the tether 56,
It can be easily formed.

Therefore, in the airbag 41 of the embodiment, it is possible to prevent damage to the joining portion 71 of the tether 56 with the airbag body 42 with a simple structure.

The folded portion 58 of the strip-shaped tether 56 is
The tethers 56 may be provided at both edges 64 in the width direction X, but at the both edges 64 in the width direction X of the tether 56,
When one edge 64 receives a larger tension than the other edge 64, even if the folding portion 58 is provided only on the one edge side 64 and the tether 56 is coupled to the airbag body 42 side. Good.

Further, in the embodiment, the folded portion 58 is formed into the edge portion 6.
Although the number of sheets 4 and the number of overlapping portions 65 are two, the number of sheets of the cloth material 60 of the folding portion 58 to be overlapped may be increased by further providing a fold C.

Further, in the embodiment, the folded portion 58 of the tether 56 and the folded portion 5 of the airbag body 42.
A reinforcing cloth 73 having flexibility is interposed between the joint portion 50 and the joint portion 50. Therefore, the reinforcing cloth 73 serves as a cushioning material for the airbag body 42, and the airbag body 42
It is possible to prevent breakage of the connecting portion 50 with the tether 56 in the.

Further, in the embodiment, the reinforcing cloth 73 is integrated with the tether cloth material 60. Therefore, as compared with the case where the reinforcing cloth 73 is a separate body from the tether cloth material 60, positioning work such as positioning of the tether cloth material 60 and the reinforcing cloth 73 in the airbag body 42 becomes easier. That is, if the reinforcing cloth 73 is separate from the tether cloth material 60, it may be largely disengaged or dropped from between the tether cloth material 60 and the airbag body 42. However, if the reinforcing cloth 73 is integrated with the tether cloth material 60 as the reinforcing portion 69 as in the embodiment, the tether cloth material 60 is formed.
It is prevented from being largely disengaged or dropped from between the airbag body 42 and the airbag body 42.

Of course, if the above-mentioned action and effect are not taken into consideration, the reinforcing cloth 69 may not be provided on the tether cloth material 60, and the reinforcing cloth 73 may be provided separately from the tether cloth material 60. Good.

Further, in the embodiment, the reinforcing cloth 73 has the outer peripheral edge connected to the airbag main body 42, and the peripheral edge connecting portion 7 is formed.
5 is provided and is joined to the airbag body 42, and the peripheral edge joining portion 75 is located at the folding portion 58 of the joining portion 71 of the tether 56 with the airbag body 42.
It is arranged so as to surround a.

With such a structure, in the area 51 of the airbag body 42 surrounded by the reinforcing cloth 73, the entire periphery of the airbag body 42 at the time of inflation, particularly in the airbag body 42, is provided by the peripheral edge joint portion 75. The tensile force of the portion of the tether 56 away from the connecting end 57 becomes difficult to propagate. Therefore, the airbag body 42 in the tether 56
The tensile force of the entire airbag body 42 is less likely to be propagated to the edge-side end portion 71a of the joining portion 71 with the fold portion 58 of the tether 56 located at the edge-side end portion 71a and the airbag body 42. The bond strength is improved.

Further, in the case of the embodiment, the connecting portion 71 of the tether 56 with the airbag body 42 and the peripheral connecting portion 75 of the reinforcing cloth 73 are provided with the connecting portion 77, and the suture thread 54 is provided.
Are formed by continuous stitching. for that reason,
Since these joining portions 71 and 75 can be formed by continuous work without cutting the suture thread 54, the joining work of the body side end portion 63 of the tether 56 and the reinforcing cloth 73 to the airbag body 42 can be easily performed. .

The action and effect as described above is obtained by the reinforcing cloth 7
Even when 3 is separated from the tether cloth material 60, the same result can be obtained.

When the reinforcing portion as the reinforcing cloth is formed integrally with the tether cloth material, the tether cloth material 60A shown in FIGS. Similar to the tether cloth material 60, the tether cloth material 60A is formed of a flexible woven cloth, and if it is spread flat, as shown in FIG. The two reinforcing portions 69 that form the cloth 73 are provided.

However, each reinforcing portion 69 of the cloth material 60A is
Similar to the cloth material 60, it is on both left and right edges of the main body side end portion 63 of the connection piece portion 61, but does not extend from the main body side end portion 63 to the left and right sides and extends in a direction away from the tether side end portion 62. ing. Further, the edge-side end portion 71 a of the connecting portion 71 of the body-side end portion 63 with the airbag body 42 is the reinforcing portion 69.
The reinforcing portion 69 projects from the main body side end portion 63 with the extending portion 79 interposed so as to be arranged near the center of the.
The extending portion 79 has a width dimension W0 of the folding portion 58 formed on the edge side in the width direction X of the tether 56 and extends from the left and right edges 64 of the connecting piece portion 61.

To bond the cloth material 60A to the airbag body cloth material 43, first, from the state where each cloth material 60A is unfolded flat, to the left and right edge portions 64 side of the connecting piece portion 61, While making a fold C along the length direction Y of the tether 56,
The edge portion 64 is folded so as to overlap the overlapping portion 65, and the folded portion 58 is formed. At this time, the extension 79 side is also folded. Thereafter, a fold C1 along the width direction X of the tether 56 is attached to a boundary portion between each extending portion 79 and the reinforcing portion 69, and each reinforcing portion 69 is folded toward the edge portion 64 side of the folding portion 58 (Fig. 15
reference).

Then, each reinforcing cloth 69 is applied to a predetermined portion of the airbag body cloth material 43 (a predetermined portion on the inner peripheral surface side of the airbag main body 42), and the main body side end portion 6 of the connecting piece portion 61.
3 is applied to a predetermined portion of the airbag body cloth material 43, and the joining portions 71, 75, 77 are formed by the operation of the industrial sewing machine using the suture thread 54, and the main body side end of the connecting piece portion 61. While connecting the part 63 to the main body cloth material 43,
The reinforcing portion 69 forming the reinforcing cloth 73 is joined to the main body cloth material 43.

It should be noted that, in the peripheral edge joint portion 75, as shown in FIG.
As shown in 2.13, the tether side end portion 6 of the connecting piece portion 61
2 side, causing the edge end 71a of the binding site 71 to rise.
You may make it extend so that the length which surrounds the circumference of may be lengthened.
Furthermore, the tip end portion 75a may be bent and directed toward the edge end portion 71a so that stress concentration does not occur when the inflation of the airbag body 42 is completed.

Further, in the embodiment, the case in which the reinforcing cloth 73 is provided and the tether 56 is coupled to the airbag body 42 is shown, but as shown in FIGS. 16 to 19, the tether 56 is not provided and the tether 56 is not provided. Only the folded portion 58 may be formed at the edge of the width direction X of 56 to be joined to the airbag body 42.

Further, when the connecting portion 71 of the connecting end 57 of the tether 56 with the airbag body 42 is formed by suturing using the suture thread 54, as shown in FIG. It may be formed by a plurality of (two in the illustrated example) linear stitch lines L1 and L2 along X.

Further, the edge side end portion 71 of the connecting portion 71 is
In order to cope with the large stress concentration acting on a, as shown in FIG. 17, the stitching lines L1 and L2 of the edge end 71a are formed.
May be connected by a semi-circular suture line L3, or as shown in FIG. 18, the suture lines L1 and L2 may be connected by an arc-shaped suture line L4.

When the arcuate lines L3 and L4 are provided at the ends of such a straight stitching line, as shown in FIG.
As shown in, the straight stitch line L1 may be a single line.

Further, in the embodiment, the suture thread 54 is used as the connecting means for connecting the tether 56 and the reinforcing cloth 73 to the airbag body 42, but the connecting means is not limited to this, and for example, an adhesive is used. You may use agents etc.

Further, in the embodiment, one strip-shaped tether 56 in which the coupling ends 57 are arranged at two positions at both ends in the lengthwise direction.
However, even in the case of a tether having three connecting ends that are connected to the airbag body, such as a three-pronged tether, or a tether having more connecting ends, the connecting ends of those tethers are described. On the side, the folding part of the present invention is provided,
The present invention may be applied.

Furthermore, in the embodiment, the airbag of the airbag device S for knee protection is described as an example. However, the airbag to which the present invention is applicable is not limited to this, and may include a tether. For example, the present invention can be applied to airbags such as side collision airbag devices, passenger seat airbag devices, steering wheel airbag devices, and the like.

Further, according to the present invention, not only the airbag in which the tether is connected to the inner peripheral surface side of the airbag main body but also the outer peripheral surface side of the airbag main body is regulated so as to regulate the inflated shape of the airbag main body. The present invention can also be applied to an airbag in which a tether is combined.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view in the vehicle front-rear direction showing a usage state of a knee protection airbag device using an airbag according to an embodiment of the present invention.

FIG. 2 is a schematic enlarged cross-sectional view in the vehicle front-rear direction of the knee protection airbag device shown in FIG.

3 is a cross-sectional view of a III-III portion of FIG.

FIG. 4 is a schematic front view showing a usage state of the knee protecting airbag device shown in FIG. 1, as seen from the vehicle rear side.

FIG. 5 is a front view of the airbag used in the embodiment.

6 is a schematic enlarged cross-sectional view of a VI-VI portion of FIG.

FIG. 7 is a partial perspective view showing a joined state of the tether of the airbag and the airbag body of the embodiment.

FIG. 8 is a partially omitted plan view in which the tether cloth material of the embodiment is flatly developed.

FIG. 9 is a perspective view illustrating a folded state of the tether cloth material according to the same embodiment.

FIG. 10 is another perspective view illustrating the folded state of the tether cloth material according to the same embodiment.

FIG. 11 is a perspective view of the state shown in FIG. 10 viewed from the opposite side.

FIG. 12 is a partial perspective view showing a combined state of the tether and the airbag body when another tether cloth material is used.

FIG. 13 is a perspective view of the state shown in FIG. 12 viewed from the opposite side.

FIG. 14 is a partially omitted plan view in which the tether cloth material shown in FIGS.

FIG. 15 is a perspective view illustrating a folded state of the tether cloth material illustrated in FIG.

FIG. 16 is a partial perspective view showing a combined state of another tether and an airbag body.

FIG. 17 is a partial perspective view showing a combined state of still another tether and an airbag body.

FIG. 18 is a partial perspective view showing a combined state of still another tether and an airbag body.

FIG. 19 is a partial perspective view showing a combined state of still another tether and an airbag body.

[Explanation of symbols]

41 ... Airbag, 42 ... Airbag body, 43 ... Base fabric for airbag body, 54 ... suture, 56 ... Tether, 57 ... Join end, 58 ... fold, 60 / 60A ... Cloth for tether, 64 ... edge, 65 ... the overlapping part, 69 ... Reinforcement part, 71 ... Main body side binding site, 71a ... edge side end, 73 ... Reinforcing cloth, 75 ... peripheral binding site, 73 ... Reinforcing cloth, upper edge, 56 ... Sutured site (coupling site), Y ... longitudinal direction of tether, X ... Width direction of tether.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshio Mizuno             Aichi Prefecture Kasuga-cho, Nishikasugai-gun Ochiai character Nagahata 1             Address within Toyoda Gosei Co., Ltd. F term (reference) 3D054 AA02 AA08 BB13 BB23 CC11                       CC34 CC42 CC43 DD14

Claims (5)

[Claims] 1. A flexible bag-shaped airbag main body that constitutes an outer peripheral wall at the time of completion of inflation, and a lengthwise end portion as a connecting end for connecting to the airbag body. A tether made of a flexible band-shaped cloth material capable of restricting the shape of the airbag body, wherein the connecting end of the tether has a width of the tether. At least one edge side in the direction, so as to make a crease along the length direction of the tether, a fold portion formed by folding the edge of the cloth material for the tether, the fold portion of the tether, An airbag, wherein the airbag material is joined to the airbag body in a state where the cloth materials are overlapped and integrated. 2. A flexible reinforcing cloth is interposed between the folded portion of the tether and a joint portion of the airbag body with the folded portion. The airbag according to claim 1. 3. The airbag according to claim 2, wherein the reinforcing cloth is connected to the tether cloth material and is integrated with the tether cloth material. 4. The reinforcing cloth is connected to the airbag body by providing a peripheral connecting portion having an outer peripheral edge connected to the airbag body, and the peripheral connecting portion is the airbag body of the tether. The airbag according to claim 2 or 3, wherein the airbag is arranged so as to surround an edge-side end portion located at the folded portion in a joint portion with. 5. The connecting part of the tether to the airbag body and the peripheral connecting part of the reinforcing cloth are formed by stitching continuous sutures. The airbag described in.