JP7043005B2 - Airbag - Google Patents

Description

The present invention relates to an airbag that is folded and stored in a storage portion and inflates so as to protect an occupant seated in a seat by inflowing an expansion gas into the storage portion.

Conventionally, the airbag includes a bag-shaped bag body and a rectifying cloth for rectifying the expansion gas that has flowed into the inside through the inflow opening formed in the bag body and arranged inside the bag body. There was one having a configuration (see, for example, Patent Document 1). In this airbag, the rectifying cloth covers the upper part of the inflow opening and has a substantially tubular shape with both ends open, and the inflow opening is provided inside the bag body from the outflow openings provided on both ends. It was configured to allow the expansion gas to flow out so as to be substantially along the opening surface of the above.

Japanese Unexamined Patent Publication No. 2014-69582

However, in a conventional airbag, the rectifying cloth is configured as a mere tubular shape, and the openings arranged on both sides of the area covering the upper part of the inflow opening are greatly opened toward the vicinity of the inflow opening, and this opening is opened. Is an opening for outflow, so when the bag body is folded and stored in the storage part, and then the expansion gas flows into the inside to expand, the expansion gas once flows into the rectifying cloth. However, when it is discharged from the outflow opening, it may be deflected by the side wall of the storage portion where the bag body is stored, and there is room for improvement in that the expansion gas is accurately rectified.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide an airbag capable of accurately rectifying the expansion gas that has flowed into the inside by a rectifying cloth and causing it to flow out into the bag body. do.

The airbag according to the present invention is an airbag that is folded and stored in a storage portion and inflates so as to protect an occupant seated in a seat by inflowing an expansion gas into the airbag.
It is composed of a flexible sheet body, has an inflatable bag shape by allowing an expansion gas to flow into the inside, and has an inflow opening for allowing the expansion gas to flow into the inside, and is used for inflow. The bag body is configured so that the periphery of the opening can be attached to the storage site side,
A rectifying cloth that is placed inside the bag body and allows the expansion gas that has flowed in through the inflow opening to flow out in a direction that substantially follows the opening surface of the inflow opening.
Equipped with
The rectifying cloth is configured so that the outflow opening for allowing the expansion gas to flow out into the bag body is offset to the occupant side from the inflow opening when the airbag is expanded and expanded. It is a feature.

In the airbag of the present invention, since the outflow opening provided in the rectifying cloth is offset not on the inflow opening side but on the occupant side away from the inflow opening, the bag main body passes through the inflow opening. The expansion gas that has flowed in can not be directed directly from the inflow opening to the outflow opening side, but can be discharged from the occupant side away from the inflow opening. Therefore, it is possible to prevent the expansion gas that has flowed into the inside from being deflected by the side wall of the storage portion that houses the bag body, and the bag body that protrudes from the storage portion at the initial stage of expansion of the airbag is rectified. The expansion gas that flows into the interior while being rectified by the bag can be widely deployed around the storage area, and the bag body can be prevented from protruding excessively toward the occupant side and can be quickly expanded and expanded. ..

Therefore, in the airbag of the present invention, the expansion gas that has flowed into the inside can be accurately rectified by the rectifying cloth and discharged into the bag body.

Further, the airbag of the present invention is specifically configured to be mounted on the steering wheel of the vehicle, and the rectifying cloth has at least two outflow openings that are substantially radial around the inflow opening. It is preferable that the configuration is arranged.

Further, in the airbag having the above configuration, the outflow openings are arranged at four locations.
It is preferable to form the rectifying cloth in a substantially square shape by connecting the peripheral edges of the rectifying cloth constituent panel in which notches for forming outflow openings are arranged at the four corners.

If the airbag has the above configuration, the rectifying cloth can be easily manufactured, and by arranging the outflow openings at four radial locations, the bag body flows in at the initial stage of expansion of the bag body. It can be widely deployed in a well-balanced manner along the opening surface of the opening.

Furthermore, in the airbag having the above configuration, the rectifying cloth is provided with a ceiling wall portion arranged so as to cover above the inflow opening, and the upper edge of the outflow opening is close to the outer peripheral edge of the ceiling wall portion. When the airbag is expanded and expanded, the expansion gas that has flowed into the interior through the inflow opening is brought into contact with the ceiling wall to maintain the deflected state as much as possible, and the outflow opening is maintained. It is preferable because it can be discharged into the bag body.

Furthermore, in the airbag having the above configuration, the bag body is attached to the storage portion side with an inflow opening, and the top plate is arranged on the occupant side while facing the attachment portion when the expansion is completed. As a configuration including a portion and a peripheral wall portion arranged between the mounting portion and the top plate portion, the expansion complete shape may be configured to be substantially a barrel shape. Even if the bag body is expanded in such a bulky manner, the rectifying cloth can prevent the expansion gas from flowing toward the top plate portion at the initial stage of expansion of the bag body. It is possible to accurately prevent the portion from protruding toward the occupant side more than necessary.

It is a schematic plan view which shows the airbag device for a handle using the airbag which is one Embodiment of this invention. It is a schematic vertical sectional view when the airbag device for a steering wheel of FIG. 1 is mounted on a vehicle. It is a schematic perspective view of the state in which the airbag used for the airbag device for a steering wheel of FIG. 1 is inflated by itself. It is a schematic vertical sectional view of the airbag of FIG. It is a schematic cross-sectional view of the airbag of FIG. 3, and is the figure which shows the state which looked at the inflow opening side. FIG. 3 is a schematic perspective view showing a state in which the rectifying cloth used in the airbag of FIG. 3 is inflated by itself. It is a top view which shows the base cloth which constitutes the airbag of FIG. It is a top view which shows the state which expanded the rectifying cloth composition panel which constitutes a rectifying cloth flat. It is a schematic diagram explaining the process of manufacturing a rectifying cloth. FIG. 3 is a schematic vertical sectional view showing a state in which the airbag has completed expansion in the airbag device for a steering wheel according to the embodiment. It is a schematic diagram which shows the rectifying cloth of another form.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, the airbag 20 for the steering wheel is taken as an example and described. The airbag 20 is used in a steering wheel airbag device (hereinafter abbreviated as "airbag device") M mounted on the steering wheel W as shown in FIGS. 1 and 2. The handle W includes a handle body 1 and an airbag device M arranged above the boss portion B in the center of the handle body 1. In the case of the embodiment, the steering wheel body 1 includes a substantially annular ring portion R that is gripped when the vehicle is steered, a boss portion B that is arranged substantially in the center of the ring portion R and is connected to the shaft SS, and a boss portion B. It is provided with four spoke portions S for connecting the ring portion R. In the embodiment, the front-back, up-down, and left-right directions are based on the straight-ahead steering of the handle W mounted on the vehicle unless otherwise specified, and the shaft SS to which the handle W is assembled (see FIG. 2). The vertical direction along the axial direction of the shaft SS is the vertical direction, the front-rear direction of the vehicle which is the axis orthogonal direction of the shaft SS is the front-rear direction, and the left-right direction of the vehicle which is the axial orthogonal direction of the shaft SS is the left-right direction. It shows the direction.

As shown in FIGS. 1 and 2, the handle body 1 is arranged so as to connect each portion of the ring portion R, the boss portion B, and the spoke portion S, and includes a core metal 3 made of a metal such as an aluminum alloy. There is. A coating layer 5 made of synthetic resin is coated on the portion of the ring portion R in the core metal 3 and the portion on the ring portion R side in each spoke portion S. Further, a steel boss 4 for inserting the shaft SS and fixing the nut N is arranged at the portion of the boss portion B in the core metal 3. Further, a lower cover 6 made of synthetic resin that covers the lower part of the boss portion B is arranged at the lower portion of the handle body 1.

As shown in FIG. 1, the airbag device M is arranged at a boss portion B substantially in the center of the handle W, and supplies an expansion gas to the airbag 20 that is folded and stored and the airbag 20. The inflator 11, the case 12 as a storage part for storing and holding the airbag 20 and the inflator 11, the airbag cover 14 covering the folded airbag 20, and the airbag 20 and the inflator 11 in the case 12. It is equipped with a retainer 10 for mounting.

As shown in FIG. 2, the inflator 11 includes a substantially cylindrical main body portion 11a having a plurality of gas discharge ports 11b, and a flange portion 11c for attaching the inflator 11 to the case 12. The flange portion 11c is formed with a through hole (not shown) for passing each bolt (not shown) of the retainer 10.

As shown in FIG. 2, the case 12 as a storage portion is made of sheet metal, and has a substantially rectangular bottom wall portion 12a to which the inflator 11 is inserted and attached from below, and a peripheral wall extending vertically from the outer peripheral edge of the bottom wall portion 12a. A part 12b and the like are provided. A mounting piece 12c extending outward is formed at the upper end of the peripheral wall portion 12b (see FIG. 1), and a mounting board of a horn switch mechanism (not shown) is mounted on the mounting piece 12c. Then, using this mounting board (not shown), the case 12 is mounted and fixed to the core metal 2 of the handle W, and the airbag device M is mounted on the upper part of the boss portion B of the handle body 1 already mounted on the shaft SS. The Rukoto. Further, a side wall portion 14c of the airbag cover 14 is attached to the peripheral wall portion 12b of the case 12 by using a rivet 15 or the like (see FIG. 2). In the case of the embodiment, the airbag 20 and the inflator 11 use a bolt (not shown) of the retainer 10 arranged in the airbag 20 as a mounting means, and the bolt (not shown) is used as an inflow opening in the mounting portion 22 of the airbag 20. It is attached to the bottom wall portion 12a of the case 12 by penetrating it through the mounting hole 24 on the peripheral edge of the 23, the bottom wall portion 12a of the case 12, and the flange portion 11c of the inflator 11 and fixing it with a nut (not shown).

The airbag cover 14 is made of synthetic resin and has a ceiling wall portion 14a that covers the upper part of the airbag 20 housed in the case 12 and a side wall portion 14c having a substantially square cylinder shape that extends downward from the vicinity of the outer peripheral edge of the ceiling wall portion 14a. And have. The ceiling wall portion 14a is formed with two door portions 14b, 14b that are pushed by the inflatable airbag 20 and open back and forth.

As shown in FIGS. 3 to 5, the airbag 20 includes a bag-shaped bag main body 21 and a rectifying cloth 30 and a tether 45 arranged inside the bag main body 21.

As shown by the two-dot chain line in FIGS. 1 and 2, the bag body 21 is arranged so as to cover substantially the entire upper surface of the ring portion R of the handle W when the expansion is completed, and the case 12 as a storage portion. A peripheral wall arranged between the mounting portion 22 and the top plate portion 28 which faces the mounting portion 22 and is arranged on the occupant side (upper end side) when the expansion is completed. A portion 25 is provided, and the expansion completed shape is substantially a barrel shape. More specifically, in the case of the embodiment, the bag main body 21 is abbreviated as if the outer shape of the bag body 21 as seen from the vertical direction side is chamfered at each corner and each side is gently curved and projected outward. The outer shape is square and slightly tapered so that the upper region on the top plate 28 side is wide and the width is narrower toward the mounting portion 22. At the same time, each corner is chamfered to form a substantially trapezoidal shape in which each side is gently curved and slightly protrudes outward (see the two-dot chain line in FIGS. 1 and 2).

The mounting portion 22 is formed with an inflow opening 23 for allowing the expansion gas G to flow into the inside, which is circularly opened. The inflow opening 23 is for inserting the main body portion 11a of the inflator 11 from below, and four mounting holes 24 through which bolts (not shown) of the retainer 10 are inserted are formed on the peripheral edge of the inflow opening 23. Has been done. The mounting portion 22 is such that the peripheral edge of the inflow opening 23 is mounted on the case 12 side by the retainer 10.

The peripheral wall portion 25 has a substantially barrel shape in which the intermediate portion between the mounting portion 22 and the top plate portion 28 is greatly inflated and converged (reduced in diameter) toward the mounting portion 22 side and the top plate portion 28 side, respectively. The binding sites 26 formed by connecting the peripheral edges 58 and 59 of the peripheral wall constituent panel 57, which will be described later, are arranged at four locations radially around the opening center C of the inflow opening 23. (See Fig. 5). Specifically, the peripheral wall portion 25 has an outer shape when viewed from the left-right direction side when the expansion is completed, so that the upper region on the top plate portion 28 side is wide and the width is narrow toward the mounting portion 22 side. In addition, it is configured to be slightly tapered. In the case of the embodiment, the coupling portion 26 is inflated during straight-ahead steering of the handle W, and the peripheral wall portion 25 is substantially the entire length at four locations, the front and rear sides and the left and right sides of the opening center C in the inflow opening 23. It is formed so as to be continuously along the axial direction (that is, the vertical direction) of the peripheral wall portion 25. More specifically, each binding site 26 converges toward the upper end 26a side so as to reduce the mutual separation distance when the expansion of the airbag 20 is completed, and the upper end 26a side enters the region of the top plate portion 28. It is formed so as to be curved (see FIG. 4).

The rectifying cloth 30 disposed in the bag main body 21 allows the expansion gas G that has flowed in from the inflow opening 23 into the bag main body 21 and the opening surface of the inflow opening 23 (in the case of the embodiment, the handle W). It is a member for flowing out in a direction substantially along the ring surface RF). The rectifying cloth 30 includes a mounting portion 31 mounted on the case 12 together with the mounting portion 22 of the bag body 21, a ceiling wall portion 33 arranged so as to cover above the inflow opening 23, and the mounting portion 31 and the ceiling wall portion. It is provided with a side wall portion 32 arranged between the side wall portion 32 and an outflow opening 35 for allowing the expansion gas G to flow out into the bag main body 21. The mounting portion 31 is formed with openings 31a and 31b formed corresponding to the inflow opening 23 and the mounting hole 24. Specifically, the mounting portion 31 is composed of a region pressed by the retainer 10 together with the mounting portion 22 in the bag body 21 when mounted on a vehicle, and is actually a peripheral edge of the inflow opening 23 (opening 31a). Is connected to the attachment portion 22 side of the bag body 21 by sewing with a suture thread at the site of. The side wall portion 32 is a portion inclined so as to rise from the mounting portion 31, and an outflow opening 35 is arranged on the tip side on the ceiling wall portion 33 side. The ceiling wall portion 33 faces the inflow opening 23 vertically and vertically, and is arranged so as to substantially follow the ring surface RF when the expansion of the airbag 20 is completed (see FIG. 10). Specifically, in the case of the embodiment, the rectifying cloth 30 has a substantially quadrangular frustum shape such that the shape of the bag body 21 at the time of completion of expansion is expanded toward the ceiling wall portion 33 side, and the upper end of the side wall portion 32 is formed. The side is covered with the ceiling wall portion 33 over substantially the entire surface, and the outflow openings 35 are arranged at the four corners of the ceiling wall portion 33. That is, the outflow opening 35 is configured such that the upper edge 35b is arranged close to the outer peripheral edge 33b of the ceiling wall portion 33 so as to be offset toward the occupant side (upper side) from the inflow opening 23 (opening 31a). Is. The outflow openings 35 are arranged at four locations radially around the opening center C of the inflow opening 23, and more specifically, in a state where the bag body 21 is inflated during straight-ahead steering of the handle W. , The inflow opening 23 is formed at four locations, front and rear sides and left and right sides of the opening center C, and each is arranged at a position above the ring surface RF (see FIG. 10). Each outflow opening 35 is configured so that the opening surface 35a is substantially orthogonal to the ring surface RF when the airbag 20 is expanded and expanded (see FIG. 10), and the expansion gas from the outflow opening 35 is formed. G will be discharged so as to be substantially along the ring surface RF (so as to be substantially along the direction orthogonal to the opening surface 35a).

The rectifying cloth 30 is formed by connecting the peripheral edge 41 of the rectifying cloth constituent panel 40 shown in FIG. 8, and the peripheral edge 41 of the rectifying cloth constituent panel 40 is coupled to the ceiling wall portion 33. Four binding sites 34 are arranged so as to extend from the center toward each outflow opening 35 in all directions (see FIGS. 4 and 6). That is, each outflow opening 35 is arranged on the tip 34b side of each binding site 34. In the case of the embodiment, each binding site 34 is formed so as to provide a slight gap between the terminals 34a arranged on the central side of the ceiling wall portion 33 (see the two-dot chain line in FIG. 8). Specifically, each binding site 34 is configured by bending terminals 34a located on the center side of the ceiling wall portion 33 so as to face the end edge side while not overlapping each other and providing a gap between them. .. Due to such a gap between the terminals 34a of each binding site 34, the rectifying cloth 30 of the embodiment has a small opening 33a substantially in the center of the ceiling wall portion 33 (see FIGS. 4 and 6). The opening 33a causes a small amount of the expansion gas that has flowed into the rectifying cloth 30 to be discharged to the bag body 21 side when the airbag 20 is expanded and expanded, and is coupled by the discharge of such a small amount of the expansion gas. It is possible to suppress the occurrence of stress concentration on the terminal 34a of the site 34 and suppress excessive damage to the binding site 34.

Specifically, as shown in FIG. 8, the rectifying cloth constituent panel 40 constituting the rectifying cloth 30 has a substantially square outer shape, and has notches 42 for forming outflow openings arranged at four corners. Has been done. An opening 31a corresponding to the inflow opening 23 is formed in the center of the rectifying cloth configuration panel 40 so as to substantially coincide with the center, and an opening 31b corresponding to the mounting hole 24 is formed on the peripheral edge of the opening 31a. , Is formed. Each notch 42 is formed so as to cut out the four corners of the rectifying cloth constituent panel 40 in a substantially square shape. Then, the rectifying cloth 30 is folded back so that the rectifying cloth component panel 40 is folded in half on the diagonal line CL (see A in FIG. 9), and the folded peripheral edges 41 and 41 are on the side closer to the folded diagonal line CL. Half of the above is sewn with sutures so as to form the binding site 34 (see B and C in FIG. 9), and such joining operations are performed in order along the circumferential direction centered on the opening 31a. By doing so, it can be produced by forming four binding sites 34. In the embodiment, as shown in FIGS. 4 and 6, the rectifying cloth 30 is used in an inverted state so that the binding margin (suture margin) of the binding site 34 is not exposed to the outside.

The tether 45 disposed in the bag body 21 is arranged so as to connect the mounting portion 22 and the top plate portion 28, and regulates the separation distance between the mounting portion 22 and the top plate portion 28 when the expansion is completed. In the case of the embodiment, the inflow opening 23 is formed at four substantially radial locations around the opening 23. Specifically, the tether 45 is formed in a substantially band shape so as to be offset from the outflow opening 35 formed in the rectifying cloth 30, and is diagonally forward left and diagonally forward right about the opening center C of the inflow opening 23. , Left diagonally rearward and right diagonally rearward, respectively, are arranged so that the width direction is inclined with respect to the front-rear direction and the left-right direction (see FIG. 5). The tether 45 is composed of two tether base materials 47U and 47D as shown in FIG. 7. The tether base materials 47U and 47D are the mounting side portions 48U and 48D coupled to the top plate portion 28 side and the mounting portion 22 side, respectively, and the strip-shaped 4 extending radially from the outer peripheral edges of the mounting side portions 48U and 48D, respectively. It is configured to include two tether components 49U and 49D, and the corresponding tether components 49U and 49D are connected to the top plate 28 side and the mounting 22 side with the mounting side portions 48U and 48D. The tether 45 is formed by connecting the ends of the tethers to each other.

The bag body 21 of the embodiment is composed of the airbag base material 55 shown in FIG. 7. The airbag base material 55 includes a top plate constituent panel 56 constituting the top plate portion 28, four peripheral wall constituent panels 57 extending substantially radially from the top plate constituent panel 56, and the tip end side of one peripheral wall constituent panel 57. The mounting configuration panel 62 is provided in the above. In the case of the embodiment, the airbag base material 55 is configured to have a substantially symmetrical shape in the front-rear and left-right directions, except for the mounting configuration panel 62.

In the case of the embodiment, the top plate configuration panel 56 is composed of a substantially square area such that diagonal lines are substantially along the front-rear direction and the left-right direction (so that corners are arranged on both the front-rear side and the left-right side). Has been done.

Each peripheral wall constituent panel 57 (57A, 57B, 57C, 57D) is formed so as to extend in all directions from each edge of the top plate constituent panel 56, and is formed diagonally forward to the left and right from the top plate constituent panel 56. It is formed so as to extend diagonally forward, diagonally to the left, and diagonally to the right. In the case of the embodiment, each peripheral wall configuration panel 57A, 57B, 57C, 57D is configured by matching the outer shape, and specifically, the outer shape is the mounting side end portion 57b which is the mounting portion 22 side. Peripherals 58A, 58B, 58C, 58D, 59A, 59B, 59C, 59D so as to be wide from the (tip) to the intermediate portion and converge to the top plate side end portion 57a (original portion) which is the top plate portion 28 side. Is configured as a substantially band shape curved in a curved shape. In each peripheral wall constituent panel 57, the peripheral edges 58 and 59 are configured as a substantially axisymmetric shape with respect to the center line passing through the center in the width direction of the peripheral wall constituent panel 57.

The mounting configuration panel 62 is formed so as to extend from the mounting side end portion 57b of one peripheral wall configuration panel 57A, and has an external shape, a width dimension of one side, and a mounting side end portion 57b of each peripheral wall configuration panel 57. It has a substantially square shape that is set to be substantially the same as the width dimension. That is, the mounting configuration panel 62 is also oriented substantially the same as the top plate configuration panel 56 so that the diagonal lines are substantially along the front-rear direction and the left-right direction (the corners are arranged on both the front-rear side and the left-right side). It is configured to extend from the peripheral wall configuration panel 57A.

In the airbag 20 of the embodiment, the airbag base material 55 constituting the bag body 21, the rectifying cloth constituent panel 40 constituting the rectifying cloth 30, and the tether base materials 47U and 47D constituting the tether 45 are , Each of which is formed from a flexible woven fabric made of polyamide yarn, polyester yarn, or the like.

Next, the manufacture of the airbag 20 of the embodiment will be described. First, the mounting side portion 48D of the tether base material 47D and the rectifying cloth constituent panel 40 are overlapped on the mounting configuration panel 62 of the airbag base material 44, and the inflow opening 23 (opening 31a) is formed by drilling. And the mounting hole 24 (opening 31b), and sewn with suture at the peripheral portion of the inflow opening 23, and the mounting configuration panel 62 has the mounting side portion 48D and the rectifying cloth configuration panel 40. And are connected. Next, the mounting side portion 48U of the tether base material 47U is sewn onto the top plate constituent panel 56 of the airbag base material 55 using suture threads. In the tether base materials 47U and 47D, the ends of the corresponding tether components 49U and 49D are sewn together to form the tether 45. Then, the peripheral edge 49A on one side of the peripheral wall constituent panel 47A is overlapped with the peripheral edge 48B of the other adjacent peripheral wall constituent panel 47B, and the peripheral edges 49A and 48B are connected to each other by using suture so as to form a binding site 26. The sewing is performed, and such sewing operations are sequentially performed in the circumferential direction around the top plate constituent panel 56 to form four binding sites 26 to form the peripheral wall portion 25. After the peripheral wall portion 25 is formed, the peripheral edge 62a of the mounting configuration panel 62 is joined to the edge of the peripheral wall configuration panel 57B, 57C, 57D on the mounting side end portion 57b side by sewing with sutures, respectively. Then, the bag-shaped bag body 21 can be formed. Then, using the inflow opening 23, the seam allowance (coupling allowance) of the bag body 21 is inverted so as not to be exposed to the outside. After that, the rectifying cloth component panel 40 is pulled out from the inflow opening 23 on the peripheral edge 41 side, and the peripheral edges 41 are sewn together with sutures so as to form a binding site 34, whereby the rectifying cloth 30 is sewn. It can be manufactured, and at the same time, the manufacture of the airbag 20 can be completed.

The airbag 20 manufactured in this way can be mounted on a vehicle as follows. First, the airbag 20 is folded so that it can be stored in the case 12 in a state where the retainer 10 is arranged inside so that a bolt (not shown) protrudes from the mounting hole 24. After that, the folded airbag 20 is housed in the case 12, the main body portion 11a of the inflator 11 is inserted from below, and the inflator 11 and air are used by using bolts and nuts (not shown) protruding from the bottom wall portion 12a. Attach to bag 20 and case 12. Further, if the case 12 is covered with the airbag cover 14, the airbag cover 14 is attached to the case 12 by using the rivet 15 or the like, and then the horn switch mechanism (not shown) is attached to the attachment piece 12c of the case 12. The airbag device M can be assembled. The airbag device M can be mounted on a vehicle by mounting the airbag device M on the handle body 1 previously fastened to the shaft SS by using a mounting board (not shown) of the horn switch mechanism.

In the airbag device M of the embodiment, if the expansion gas G is discharged from the gas discharge port 11b of the inflator 11, the airbag 20 inflows the expansion gas into the inside and expands, and the door of the airbag cover 14 is expanded. The portions 14b and 14b are pushed open and protrude from the case 12, and the expansion is completed so as to cover substantially the entire upper surface of the handle W as shown by the two-dot chain line in FIGS. 1 and 2 and FIG.

The airbag 20 of the embodiment has a configuration in which the outflow opening 35 provided in the rectifying cloth 30 is offset not on the inflow opening 23 side but on the occupant side (upper side) away from the inflow opening 23. Therefore, the expansion gas that has flowed into the bag body 21 through the inflow opening 23 is not directed directly from the inflow opening 23 to the outflow opening 35 side, but from the upper side away from the inflow opening 23. , Can be leaked. Therefore, it is possible to prevent the expansion gas G that has flowed into the interior from being deflected by the side wall (peripheral wall portion 12b) of the case 12 as a storage portion for accommodating the bag body 21, and at the initial stage of expansion of the airbag 20. The bag body 21 protruding from the case 12 can be widely deployed around the case 12 by the expansion gas G that flows into the inside while being rectified by the rectifying cloth 30, and the bag body 21 is excessively large toward the occupant side. It can be suppressed to protrude and can be rapidly expanded and expanded.

Therefore, in the airbag 20 of the embodiment, the expansion gas that has flowed into the inside can be accurately rectified by the rectifying cloth 30 and discharged into the bag body 21.

Further, the airbag 20 of the embodiment is mounted on the steering wheel W for steering the vehicle, and the rectifying cloth 30 has the outflow opening 35 at four locations substantially radial around the inflow opening 23. Since the bag body 21 is arranged so as to be arranged substantially along the opening surface of the inflow opening 23, that is, the ring surface RF of the handle W at the initial stage of expansion, the bag body 21 is widely deployed in a wide, well-balanced manner in the front-rear and left-right directions. Can be made to. Further, since the rectifying cloth 30 is formed by overlapping and connecting the peripheral edges 41 of the rectifying cloth constituent panel 40 having notches 42 for forming outflow openings arranged at four corners in a substantially square shape. , The rectifying cloth 30 can be easily manufactured. If such a point is not taken into consideration, the number of outflow openings is not limited to four, and may be two or more.

In the airbag 20 of the embodiment, the rectifying cloth 30 includes a ceiling wall portion 33 arranged so as to cover above the inflow opening 23, an outflow opening 35, and an upper edge 35b outside the ceiling wall portion 33. Since the airbags are arranged close to the peripheral edge 33b, the expansion gas that has flowed into the interior through the inflow opening 23 is brought into contact with the ceiling wall portion 33 and deflected when the airbag 20 is expanded and expanded. It can be maintained as much as possible and can be discharged from the outflow opening 35 into the bag body 21. Specifically, in the airbag 20 of the embodiment, in the initial expansion of the bag body 21, the rectifying cloth 30 causes each outflow opening 35 to protrude from the case 12, and further, in the embodiment, the ring surface. It will be placed so that it is located above the RF. Therefore, the expansion gas G that has flowed into the rectifying cloth 30 is once filled inside, and then from the outflow opening 35 located above the peripheral wall portion 12b of the case 12, the ring surface RF of the handle W. It will be leaked so as to roughly follow. That is, in the airbag 20 of the embodiment, at the initial stage of expansion of the bag body 21, the expansion gas G is deflected in the bag body 21 and upward (on the occupant side) so as to substantially follow the peripheral wall portion 12b of the case 12. Since the flow toward the occupant can be suppressed as much as possible, it is possible to accurately suppress the bag body 21 from expanding so as to greatly project toward the occupant at the initial stage of expansion. Therefore, as in the embodiment, even if the airbag 20 is configured to expand in a bulky manner with the expansion completed shape being a substantially barrel shape, the expansion gas is directed toward the top plate portion 28 side at the initial stage of expansion of the bag body 21. Since the flow can be suppressed, it is possible to accurately prevent the top plate portion 28 from protruding toward the occupant side more than necessary at the initial stage of expansion.

In the airbag 20 of the embodiment, as described above, the peripheral edges 41 of the rectifying cloth configuration panel 40 in which the cutouts 42 for forming the outflow openings are arranged at the four corners in a substantially square shape are overlapped, and the four binding sites 34 are formed. The rectifying cloth 30 is configured by sewing so as to form. That is, the airbag 20 of the embodiment is formed so as to be in contact with the ceiling wall portion 33 separated from the inflow opening 23 (opening 31a) only by the planar joining work, and is formed so as to be in contact with the ceiling wall portion 33 (inflow opening 23). The rectifying cloth 30 that expands three-dimensionally can be formed so as to dispose the outflow opening 35 capable of allowing the expansion gas to flow out while substantially following the opening surface of the above), thereby suppressing an increase in manufacturing cost and man-hours. The airbag 20 can be manufactured at low cost. Further, in the rectifying cloth 30, the outflow direction and the outflow amount of the expansion gas from the outflow opening 35 can be set by adjusting the size of the notch 42, the angle of the edge, and the like. The outflow amount of the expansion gas from the outflow opening 35 can be adjusted by increasing or decreasing the notch amount of the notch portion 42. Further, the outflow direction of the expansion gas of the outflow opening 35 can be adjusted by the inclination angle of the opening surface 35a of the outflow opening 35 with respect to the side wall portion 32. Specifically, as shown in FIG. 11A, if the cutout portion 42A is configured to shallowly cut out the rectifying cloth configuration panel 40A (set a large inclination angle with respect to the peripheral edge 41A of the edge of the cutout portion 42A). In the rectifying cloth 30A, the outflow opening 35A is arranged so that the opening surface 35a has a smaller inclination angle with respect to the side wall portion 32A. The expansion gas G has a large inclination angle with respect to the ring surface RF as compared with the case where the notch 42B is formed by making a notch (setting the inclination angle of the edge of the notch 42B with respect to the peripheral edge 41B to be small). Then, it flows so as to rise diagonally upward from the ring surface RF. That is, the inclination of the expansion gas flow from the outflow opening 35 is proportional to the inclination angle with respect to the peripheral edge 41 of the edge of the notch 42.

Further, in the rectifying cloth 30 of the embodiment, since the opening 33a formed by the gap between the terminals 34a of the binding site 34 is formed in the vicinity of the center of the ceiling wall portion 33 by a small opening, the airbag 20 is formed. A small amount of the expansion gas flowing into the rectifying cloth 30 can be discharged to the bag body 21 side from the opening 33a at the time of expansion and expansion, and the binding site 34 can be discharged by such a small amount of the expansion gas. It is possible to suppress the occurrence of stress concentration on the terminal 34a of the above and to prevent excessive damage to the binding site 34. If such a point is not taken into consideration, the binding sites may be formed so that the terminals intersect each other so as not to provide a gap. The opening area of this opening can be adjusted by increasing or decreasing the gap between the binding sites, and the opening is set so as not to discharge a large amount of expansion gas, and is used for expansion together with the outflow opening. It may be configured to allow gas to flow out.

In the embodiment, the airbag 20 for the steering wheel has been taken as an example and described. However, the airbag to which the present invention can be applied is not limited to the one for the steering wheel, and is used, for example, for the passenger airbag device. It is also applicable to airbags that are used. Further, the airbag for the steering wheel is not limited to the type that expands into a substantially barrel shape as in the embodiment, and the expansion completed shape is formed into a substantially disk shape by connecting the peripheral edges of the circular base materials to each other. It can also be applied to airbags for the type of steering wheel.

10 ... retainer, 11 ... inflator, 12 ... case (storage part) ... 12b ... peripheral wall part (side wall), 14 ... airbag cover, 20 ... airbag, 21 ... bag body, 22 ... mounting part, 23 ... inflow opening , 25 ... peripheral wall part, 28 ... top plate part, 30 ... rectifying cloth, 31 ... mounting part, 32 ... side wall part, 33 ... ceiling wall part, 33b ... outer peripheral edge, 34 ... joint part, 35 ... outflow opening, 35b ... upper edge, 40 ... rectifying cloth configuration panel, 41 ... peripheral edge, 42 ... notch, C ... opening center, G ... expansion gas, W ... handle, M ... airbag device for handle.

Claims (3)

It is an airbag that is mounted on the steering wheel of the vehicle, folded and stored in the storage part, and inflows expansion gas into the inside to protect the occupants seated in the seat.
It is composed of a flexible sheet body, has an inflatable bag shape by allowing an expansion gas to flow into the inside, and has an inflow opening for allowing the expansion gas to flow into the inside, and the inflow thereof. The bag body is configured so that the peripheral edge of the opening can be attached to the storage area side.
A rectifying cloth, which is arranged in the bag body and allows the expansion gas that has flowed into the inside from the inflow opening to flow out in a direction substantially along the opening surface of the inflow opening.
Equipped with
The rectifying cloth
When the airbag is expanded and expanded, the outflow opening for allowing the expansion gas to flow out into the bag body is configured to be offset from the inflow opening toward the occupant and arranged.
A ceiling wall portion arranged so as to cover the upper part of the inflow opening is provided, and the outflow opening is arranged at four locations substantially radial around the inflow opening.
It is formed as a substantially square shape by joining the peripheral edges of a rectifying cloth configuration panel in which notches for forming outflow openings are arranged at the four corners.
Four binding sites formed by connecting the peripheral edges of the rectifying cloth constituent panel to the ceiling wall portion of the rectifying cloth extend in all directions from the center toward each outflow opening side. , Formed,
The airbag is characterized in that the outflow opening has an upper edge arranged close to the outer peripheral edge of the ceiling wall portion . The airbag according to claim 1, wherein in the rectifying cloth, an opening formed by a gap between terminals of the binding site is formed in the vicinity of the center of the ceiling wall portion. The bag body has a mounting portion having an inflow opening and is mounted on the storage portion side, a top plate portion facing the mounting portion and arranged on the occupant side when expansion is completed, and the mounting portion. The airbag according to claim 1 or 2 , wherein the airbag is configured to include a peripheral wall portion arranged between the top plate portion and the top plate portion, and the expansion completed shape is configured as a substantially barrel shape. ..

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