JP7207091B2 - Airbag - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag configured in the shape of a bag that is inflated to protect a person to be protected by allowing inflation gas to flow therein.

Conventionally, as an airbag device, an airbag is deployed and inflated to protect a seated occupant in the event of a vehicle accident. was stored in There is a strong demand for miniaturization of airbag devices, and in order to meet this demand, for example, in Japanese Unexamined Patent Application Publication No. 2002-100000, a bag assembly is formed by wrapping an airbag folded into a small size with a film sheet. A bag assembly is disclosed in which a film sheet is preliminarily laminated with a high-strength resin layer so that the folded shape of the airbag can be maintained.

Japanese Patent Application Laid-Open No. 2007-168486

However, in Patent Document 1, in a vehicle airbag device to be mounted on a vehicle, a film sheet that wraps a small folded body of the airbag is required to maintain the folded shape of the airbag. It takes time and effort to laminate the resin layers.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide an airbag device that can more easily maintain the folded shape of the folded airbag. It is in.

In order to achieve the above object, a folded body in which a bag-like airbag, which is inflated so as to protect a person to be protected by flowing an inflation gas into the inside thereof, is folded so as to be deployed and inflatable; and a wrapping material that covers the periphery and retains the folded shape, wherein the wrapping material is formed of a nonwoven fabric having a higher deformation resistance than the airbag. The bag assembly is characterized by:

According to the above configuration, the non-woven fabric is post-processed by wrapping the folded body of the airbag with the wrapping member formed of the non-woven fabric whose deformation resistance is set higher than that of the airbag. It is possible to easily suppress the collapse of the folds. Moreover, by using a nonwoven fabric for the material of the wrapping member, it is possible to suppress damage to the airbag when wrapping the folded body.

The invention according to claim 2 is the invention according to claim 1, wherein the wrapping material is formed in a shape along the outer shape of the folded body. A bag assembly is used.

According to the above configuration, by using the wrapping material that is preliminarily formed in a shape that conforms to the outer shape of the folded body, it is possible to improve the assembling workability when wrapping the folded body with the wrapping material. It is possible to assemble without applying excessive force to the wrapping material, and it is possible to prevent damage to the wrapping material.

According to the present invention, by using a wrapping member formed of a non-woven fabric having a higher deformation resistance than the airbag, the airbag is wrapped into a folded body, thereby easily suppressing collapse of the folded body. be able to.

1 is a schematic plan view of a steering wheel equipped with an airbag device using an airbag that is an embodiment of the present invention; FIG. 1 is a vertical cross-sectional view of a steering wheel equipped with an airbag device according to an embodiment; FIG. It is a top view of the state where the airbag of embodiment was inflated by itself. FIG. 4 is a cross-sectional view of the IV-IV portion of FIG. 3; FIG. 4 is a cross-sectional view of the VV portion of FIG. 3; FIG. 4 is a schematic perspective view of a folded body in which the airbag of FIG. 3 is folded; Fig. 2 is a schematic perspective view of a folded body wrapped in a wrapping material; 4 is a schematic partial cross-sectional view of a folded body wrapped in a wrapping material; FIG. FIG. 4 is a schematic bottom view of a folded body wrapped in a wrapping material; It is a perspective view of a wrapping material. It is a cross-sectional view of the wrapping material. It is a schematic sectional drawing explaining the folding process of the airbag of embodiment. FIG. 13 is a schematic plan view for explaining a small-diameter folding step in the folding step of the airbag of the embodiment, showing the step after FIG. 12 ; FIG. 14 is a schematic plan view for explaining a small-diameter folding step in the folding step of the airbag of the embodiment, and shows the step after FIG. 13 ; FIG. 15 is a schematic cross-sectional view for explaining a compression step in the folding step of the airbag of the embodiment, showing the step after FIG. 14 ; FIG. 16 is a schematic cross-sectional view for explaining a compression step in the folding step of the airbag of the embodiment, showing the step after FIG. 15 ; FIG. 17 is a schematic cross-sectional view for explaining a compression step in the folding step of the airbag of the embodiment, showing the step after FIG. 16 ; FIG. 4 is a schematic vertical cross-sectional view showing a state in which the airbag of the embodiment has completed inflation; FIG. 4 is a schematic front view showing a state in which the airbag of the embodiment has completed inflation; It is the schematic which shows the modification of the wrapping material which wraps the folded body which folded the airbag of embodiment.

An embodiment of the present invention will be described below with reference to the drawings. In the embodiment, a steering wheel airbag 20 used in an airbag device M mounted on a steering wheel W to protect a driver MD as a person to be protected will be described as an example. The steering wheel W, as shown in FIG. 1, includes a steering wheel body 1 and an airbag device M arranged above a central boss portion B of the steering wheel body 1 . The steering wheel main body 1 includes an annular ring portion R that is gripped during steering, a boss portion B that is arranged substantially in the center of the ring portion R and is connected to the steering shaft SS, and the boss portion B and the ring portion R that are connected. and a spoke portion S to be provided.

In the embodiments, unless otherwise specified, the front-rear, up-down, left-right directions are based on the straight-ahead steering of the steering wheel W mounted on the vehicle V, and the steering shaft SS ( 2) is defined as the up-down direction, the front-rear direction of the vehicle V that is perpendicular to the axis of the steering shaft SS is defined as the front-rear direction, and the left-right direction of the vehicle V that is perpendicular to the axis of the steering shaft SS is defined as the left-right direction. , indicates the directions of front and back, up and down, and left and right.

In the steering wheel W of the embodiment, three spokes S are arranged on both the left and right sides of the boss B and on the rear side. As shown in FIGS. 1 and 2, the steering wheel body 1 includes a core metal 2 made of a metal such as an aluminum alloy, which is arranged so as to connect the ring portion R, the boss portion B, and the spoke portion S. ing. A portion of the core bar 2 where the ring portion R is located and a portion of each spoke portion S on the ring portion R side are covered with a synthetic resin coating layer 5 . A steel boss 4 for inserting the steering shaft SS and fastening with a nut N is disposed at the boss portion B of the core bar 2 . Further, a lower cover 6 made of synthetic resin is arranged on the lower part of the steering wheel main body 1 to cover the lower part of the boss portion B. As shown in FIG.

The airbag device M, as shown in FIGS. 1 and 2, is arranged on a boss portion B substantially in the center of the steering wheel W. The airbag 20 is folded and accommodated, and the airbag 20 is supplied with inflation gas. an inflator 11 that supplies air, a bag holder 12 that houses and holds the airbag 20 and the inflator 11, an airbag cover (pad) 14 that covers the folded airbag 20, the airbag 20 and the inflator 11 It comprises a retainer 10 for attachment to the bag holder 12 and a wrapping material 80 for wrapping a substantially cylindrical folded body 50 formed by folding the airbag 20 .

As shown in FIG. 2, the inflator 11 includes a substantially cylindrical body portion 11a having a plurality of gas discharge ports 11b and a flange portion 11c for attaching the inflator 11 to the bag holder 12. there is The flange portion 11c is formed with through-holes (not shown) for passing the bolts 10a of the retainer 10 therethrough.

The airbag cover 14 is made of a synthetic resin such as olefinic thermoplastic elastomer (TPO), and is arranged above the boss B near the center of the steering wheel W, as shown in FIGS. The airbag cover 14 includes a ceiling wall portion 15 that covers the upper side of the airbag 20 (folded body 50) that is folded and stored inside the boss portion B, and a side wall that extends from the lower surface of the ceiling wall portion 15 in a substantially cylindrical shape. a portion 16; The ceiling wall portion 15 is formed with a disc-shaped door portion 15a that opens forward when pushed by the inflating airbag 20 . A locking leg portion 16a coupled to the bag holder 12 is formed at a predetermined location on the side wall portion 16 of the airbag cover 14 so as to extend downward.

The bag holder 12 is made of sheet metal, and holds the folded airbag 20, the inflator 11, and the airbag cover 14 as shown in FIG. It is configured to be attached to the wheel body 1 side. In the case of the embodiment, the airbag 20 and the inflator 11 are attached using the bolts 10a of the retainer 10 arranged in the airbag 20, and the bolts 10a are attached to the attachment holes on the periphery of the inflow opening 24 in the airbag 20. 25, the bag holder 12 and the flange portion 11c of the inflator 11 are passed through and attached to the bag holder 12 by fastening with nuts (not shown).

The airbag 20 is configured in the form of a bag that is inflated so as to protect the driver MD as a person to be protected by allowing an inflation gas to flow therein. and a projecting expansion part 35 as a specific expansion part arranged to partially protrude from the body expansion part 21 .

1 and 2 and FIGS. 18 and 19, the main body expansion part 21 as a general expansion part is formed in a disk shape that can cover the entire upper surface of the ring part R when expanded. The peripheral edges of the driver side wall portion 27 and the vehicle body side wall portion 23, which have substantially the same circular outer shape, are sewn together with suture thread to form a bag shape ( 4 and 5). The vehicle body side wall portion 23 is a portion that is arranged on the side of the steering wheel W when inflation is completed. is formed with four mounting holes 25 for passing bolts 10a of the retainer 10 (see FIG. 3). The driver side wall portion 27 is a portion arranged on the side of the driver MD as a person to be protected when the inflation is completed. A communication hole 28 is formed in the driver side wall portion 27 to communicate with the protruding expansion portion 35 (see FIGS. 4 and 5). The communication hole 28 is formed at a position away from the center of the driver side wall portion 27 (connecting portion of the tether 30, which will be described later). Specifically, the opening shape of the communication hole 28 is substantially the same as the external shape of the protruding expansion portion 35 when viewed from the vertical side, and the left and right centers are located in front of the center of the driver side wall portion 27. The left and right end sides of the driver side wall portion 27 are positioned substantially in the center of the front and rear sides of the driver side wall portion 27, respectively. As shown in FIGS. 4 and 5, inside the body inflation portion 21, the center of the driver side wall portion 27 and the peripheral edge of the inflow opening 24 in the vehicle body side wall portion 23 are connected to each other to provide a driving force at the completion of inflation. A tether 30 is provided to regulate the separation distance of the side wall portion 27 from the side wall portion 23 of the vehicle body. The main body inflatable portion 21 (vehicle side wall portion 23, driver side wall portion 27, tether 30) as a general inflatable portion is made of a woven fabric having gas permeability such as polyamide thread or polyester thread. In the case of the embodiment, the woven fabric forming the body inflatable portion 21 has a flexural modulus of 3.4 GPa.

The protruding inflation portion 35 as a specific inflation portion is disposed so as to protrude rearward from the driver side wall portion 27 of the main body inflation portion 21 when inflation is completed. As shown in FIG. 3, when the airbag 20 is viewed from the top and bottom, it has a substantially inverted V shape, and when the airbag 20 at the completion of inflation is viewed from the left and right, the rear end portion It is configured as a stepped shape that protrudes outward (see FIGS. 4 and 18). In addition, the protruding expansion portion 35 communicates with the main expansion portion 21 over the entire area on the side of the lower end 35a. The protruding inflatable portion 35 is arranged in the front area of the main inflatable portion 21 at the completion of inflation so as to be able to restrain the head MH to the shoulder MS of the driver MD when the inflation is completed. , the expansion completion shape is configured as a substantially symmetrical shape. More specifically, the protruding expanding portion 35 has a substantially inverted V-shape when viewed from the top and bottom, and is arranged on the head protecting portion 36 and both end sides of the head protecting portion 36 . The configuration includes shoulder restraint portions 37L and 37R. The shoulder restraint portions 37L and 37R have an inflated shape that protrudes upward from the head protection portion 36 and has a substantially columnar shape in which the axial direction thereof extends substantially along the vertical direction. It is configured to be able to restrain the shoulder portion MS of the driver MD moving forward toward the steering wheel W side at the time of completion of inflation (see FIGS. 18 and 19). More specifically, the shoulder restraint portions 37L and 37R are arranged at positions on the left and right sides of the center of the main body inflation portion 21 when the airbag 20 is viewed from the top and bottom when the inflation is completed. The head protection portion 36 is formed so as to extend toward the front of the central side from the shoulder restraint portions 37L and 37R in a state in which the inflated shape is completed, when viewed from the up-down direction side. , so that the center in the left-right direction is positioned on the front side. The head protection portion 36 has a projection amount that is about half that of the shoulder restraint portions 37L and 37R when inflation is completed (see FIGS. 4 and 5). It is configured to receive and protect the head MH of the driver MD whose both shoulders MS are restrained by 37L and 37R. Specifically, the protruding inflation portion 35 uses ceiling walls 36a, 37a arranged on the side of the driver MD in the head protection portion 36 and the shoulder restraint portions 37L, 37R as receiving surfaces for receiving the driver MD, and the sidewalls By buckling deformation of 36b and 37b, it is configured to protect the driver MD (see FIGS. 4, 5 and 18).

The protruding expansion portion 35 is made of a material that is set to have a higher resistance during deformation than the base material forming the main expansion portion 21 . In the case of the embodiment, the protruding inflatable portion 35 is made of non-woven fabric and three-dimensionally formed by deep drawing while making the thickness substantially uniform. Specifically, the nonwoven fabric forming the protruding inflatable portion 35 is set to have a higher bending elastic modulus than the woven fabric forming the main inflatable portion 21 (3.4 GPa).

In addition, the lower end 35a side of the protruding expansion portion 35 is coupled to the peripheral edge 28a of the communication hole 28 of the driver side wall portion 27 of the main expansion portion 21 along the entire circumference. It is sewn on using

The folded body 50 formed by folding the airbag 20 includes, as shown in FIGS. 54, and a substantially cylindrical three-dimensional shape having a side surface portion 55 between them. As shown in FIG. 12, the folded body 50 is folded into a small-diameter folding step (see FIGS. 13 and 14) and a compression step (FIG. 15) from the folding preparatory body 45 that has been flatly unfolded while the retainer 10 is arranged inside. 17) and is folded through. In addition, the folded body 50 has a concave portion 52 corresponding to the upper area of the columnar main body 11a of the inflator 11 so that the upper area can be accommodated in the center of the bottom surface 51. ing. Further, a concave portion 53 is provided on the outer peripheral edge side of the bottom portion 51 of the folded body 50 by recessing the outer side of the retainer 10 .

As shown in FIGS. 10 and 11, the wrapping material 80 that wraps (covers) the folded body 50 has a substantially cylindrical shape with an open bottom end. a side cover portion 82 extending substantially cylindrically from the peripheral edge of the ceiling cover portion 81 to cover the side portion 55 of the folded body 50; , and the lower end side of the side cover portion 82 serves as an insertion opening 82a for inserting the folded body 50. As shown in FIG. The mounting pieces 83 have locking holes 83a that are locked to the bolts 10a of the retainer 10 protruding from the folded body 50, and four mounting pieces 83 are provided corresponding to the bolts 10a. At the boundary portion between the ceiling cover portion 81 and the side cover portion 82, a breakable portion 84 that can be broken when the airbag 20 is deployed and inflated intermittently, except for a part, substantially along the periphery of the ceiling cover portion 81. It is formed by providing such a slit 84a. That is, the portion to be broken 84 is composed of a slit 84a and a connecting portion 84b between the slits 84a, 84a. A portion between the ends of the portion to be broken 84 constitutes a hinge portion 85 that serves as a center of rotation when the ceiling cover portion 81 is opened when the portion to be broken 84 is broken when the airbag 20 is inflated. . In the wrapping material 80, the inner diameter of the side cover portion 82 is set to be slightly larger than the outer diameter of the folded body 50 so that the folded body 50 can be inserted, and the length of the side cover portion 82 is set to The dimension is set so that the folded body 50 can be slightly compressed in the vertical direction when the folded body 50 is wrapped around (when the bolt 10a is inserted into the locking hole 83a). The wrapping material 80 is made of non-woven fabric and is three-dimensionally formed by deep drawing while making the thickness substantially uniform. The nonwoven fabric forming the wrapping material 80 has a bending elastic modulus greater than the bending elastic modulus (3.4 GPa) of the woven fabric forming the main body inflatable portion 21, so that the airbag 20 is more elastic than the airbag 20 when deformed. increasing resistance.

Next, the mounting of the airbag device M on the vehicle will be described. First, the airbag 20 is folded. The folded body 50 formed by folding the airbag 20 is formed through a small-diameter folding process and a compression process.

In the small-diameter folding process, first, as shown in FIGS. and the driver side wall portion 27 are overlapped to flatten the main body inflatable portion 21, and the protruding inflatable portion 35 is flattened and superimposed on the driver side wall portion 27 so as to flatten the airbag 20. to form a folding preparatory body 45 which is unfolded into Next, as shown in FIG. 12C, the folding preparatory body 45 is set in the bag folding machine 60, and as shown in FIGS. and fold it so that it has a small diameter.

As shown in FIG. 13, the bag folding machine 60 includes a bottom substrate 61, a ceiling substrate 64 arranged above the bottom substrate 61 so as to be movable up and down, and a bottom substrate 64 on the bottom substrate 61. It is configured to have two types of pressing tools 67 and 68 of eight each that move toward the center of the substrate 61 . A set portion 62 for fitting each bolt 10a of the retainer 10 projecting from the folding preparatory member 45 is provided in the center of the upper surface side of the bottom substrate 61 . A set portion 62 on the upper surface side of the bottom substrate 61 is formed with small unevenness that can form the concave portions 52 and 53 of the folded body 50 . Also, the portion of the set portion 62 is configured to be movable upward from the bottom substrate 61 (see C in FIG. 15). By moving the set portion 62 upward, the folded body 50 (pre-folded body 49) after the small-diameter folding process can be pushed out and taken out so as to shift to the compression process. The pushing tools 67 are configured to be able to grip eight points on the outer peripheral edge of the folding preparatory body 45 and push them toward the center (see FIG. 13). A mold surface 67a corresponding to the arc-shaped curved surface of the cylindrical side surface of the folded body is formed on the set portion 62 side of the pushing tool 67. As shown in FIG. The pushing tool 68 has a substantially triangular plate shape tapered toward the setting portion 62 side.

In the small-diameter folding step, first, as shown in FIGS. 12A and 12B, the folding preparatory body 45 is placed on the bottom side substrate 61 by setting the bolts 10a in the setting portion 62, and then, As shown in FIG. 12C, the ceiling side is placed at a predetermined height (equivalent to the height from the bottom portion 51 to the ceiling portion 54 of the folding body 50) from the set portion 62 of the bottom substrate 61. A substrate 64 is placed. Thereafter, as shown in FIG. 13, the pushing tools 67 and 68 are moved toward the set portion 62, and the pushing tools 67 are caused to grip predetermined eight positions of the outer peripheral edge 45a of the folding preparatory body 45. As shown in FIG. After that, as shown in A of FIG. 14 , each pushing tool 68 is first moved toward the setting section 62 side (inflow opening 24 side), and the area of the pushing tool 67 in the folding preparatory body 45 on the setting section 62 side is moved. are left, and the eight push-in portions 47 of the outer peripheral edge 45a of the folding preparatory body 45 are pushed toward the set portion 62 side. After that, the gripping portions 46 of the outer peripheral edge 45a of each pushing tool 67 are released, and each pushing tool 67 is moved toward the setting section 62 to set the eight positions 46 as shown in FIG. 14B. It is pushed to the part 62 side. 14B and 15A, a substantially cylindrical pre-folded body 49 equivalent to the substantially cylindrical folded body 50 is formed. .

After the small-diameter folding process, the ceiling-side substrate 64 is replaced with the ceiling-side substrate 64 provided with the tube jig 70 so that the compression process can be performed. The tube jig 70 includes a cylindrical tubular portion 70a through which the pre-folded body 49 can be inserted, and a flange portion 70b that can be attached to the periphery of the insertion hole formed in the ceiling-side substrate 64. As shown in FIG. A locking pin 70c capable of locking the side cover portion of the wrapping material 80 is arranged on the cylindrical portion 70a. As shown in FIG. 15C , the tube jig 70 is covered with the wrapping material 80 , and the set portion 62 is pushed up together with the pre-folded body 49 . 70a.

Next, as shown in FIG. 16A, the tube jig 70 containing the pre-folded body 49 is set in the set portion 73a of the fixed side portion 73 of the bag press machine 72 which performs the compression process.

The bag press machine 72 has a fixed side portion 73 and a movable side portion 76, as shown in FIG. The fixed side portion 73 has a recessed portion capable of accommodating the tube jig 70 to which the wrapping material 80 is assembled. The movable side portion 76 has a pressing jig 77 at its lower end side that forms a recessed portion 52 for accommodating the inflator 11 in the folded body 50, and is disposed so as to be vertically movable. A collar portion 78 is formed on the upper edge side to contact the bottom surface portion 51 of the folded body 50 . The collar portion 78 is formed with a through hole (not shown) through which each bolt 10a can pass.

Then, as shown in FIG. 16A, the tube jig 70 containing the prefolded body 49 is set so as to be inserted into the concave portion of the fixed side portion 73, and then, as shown in FIG. Then, by lowering the movable side portion 76 and shaping the concave portion 52 with the pressing jig 77, the folded body 50 can be formed. After the compression process, as shown in FIG. 17A, the tube jig 70 is pulled out, the movable side portion 76 is restored, and each mounting piece 83 of the wrapping material 80 is secured using the locking hole 83a. 17B), a bag assembly 90 in which the folded body 50 is wrapped with the wrapping material 80 can be obtained.

Then, the bag assembly 90 formed in this manner is fitted to the inner peripheral surface side of the side wall portion 16 of the airbag cover 14, and each locking leg portion 16a of the airbag cover 14 is inserted into the bag holder 12. to attach the airbag cover 14 to the bag holder 12 . After that, each bolt 10a protruding from the bag holder 12 is passed through a through hole (not shown) of the inflator 11, a nut (not shown) is fastened to each bolt 10a, and the airbag cover 14 is attached to the bag holder 12. Furthermore, the airbag device M can be assembled by attaching and fixing the bag assembly 90 and the inflator 11 . This airbag device M can be installed in a vehicle V by attaching it to the steering wheel body 1 which has been fastened to the steering shaft SS in advance using a mounting board (not shown) of the horn switch mechanism (not shown). can do.

In the airbag device M of the embodiment, when the inflation gas is discharged from the gas discharge port 11b of the inflator 11, the folded airbag 20 is inflated by the inflow of the inflation gas, and the wrapping material 80 is inflated. The ceiling cover portion 81 is opened by breaking the portion to be broken 84 provided, and the door portion 15a of the ceiling wall portion 15 of the airbag cover 14 is pushed open to protrude from the opened opening of the door portion 15a. , 2 and FIGS. 18 and 19, the expansion is completed so as to cover substantially the entire upper surface of the steering wheel W. FIG.

In the airbag 20 used in the airbag device M of the embodiment, when the inflation is completed, the main inflation portion 21 as the general inflation portion and the protruding inflation portion 35 as the specific inflation portion complete the inflation and protrude. The expansion portion 35 receives the driver MD. In the embodiment, the peripheral wall of the projecting expansion portion 35 as the specific expansion portion constituting the area for receiving the driver MD as the person to be protected is set to have a higher deformation resistance than the peripheral wall of the main expansion portion 21 as the general expansion portion. Therefore, when the protruding inflatable portion 35 receives the driver MD, the peripheral wall is subjected to buckling deformation or bending deformation, thereby moving toward the airbag 20 side of the driver MD. Compared to the case where the kinetic energy (moving forward) is received by the general expansion portion (main expansion portion 21), it is possible to absorb it accurately with a small receiving stroke, and to restrain the driver MD accurately. can. In addition, in the airbag 20 of the embodiment, since the projecting inflation portion 35 as the specific inflation portion is made of a material different from that of the main inflation portion 21 as the general inflation portion, the length of the peripheral wall of the projecting inflation portion 35 By changing the shape and the material itself including the , it is possible to easily adjust the amount of deformation of the peripheral wall of the projecting expansion portion 35 when receiving the driver MD, in other words, the kinetic energy of the driver MD can be easily adjusted, it is easy to adjust the occupant protection performance of the protruding inflatable portion 35 according to the vehicle type or the like.

Therefore, in the airbag 20 of the embodiment, it is possible to easily adjust the protection performance of the person to be protected according to the type of vehicle, the mounting position, and the like.

In addition, in the airbag 20 of the embodiment, the projecting inflation portion 35 as the specific inflation portion is formed of non-woven fabric and configured to inflate so as to partially protrude from the main inflation portion 21 as the general inflation portion. ing. Therefore, the protruding inflatable part 35 can be formed by three-dimensionally molding a non-woven fabric, and even if it is configured to partially protrude from the main inflatable part 21, the stitching work for manufacturing the protruding inflatable part 35 itself can be performed. is not required, the manufacturing man-hours and cost can be reduced, and the folded shape can be made compact because there is no sewn portion with a suture thread in the area of the protruding inflatable portion 35 itself. In particular, in the airbag 20 of the embodiment, the protruding inflation portion 35 includes a head protection portion 36 protruding from the driver side wall portion 27 and two shoulder restraint portions 37L protruding further upward than the head protection portion 36. , 37R and has a complicated shape, but since it is constructed by three-dimensionally molding a non-woven fabric, it is possible to appropriately suppress increases in manufacturing man-hours and costs. In the airbag 20 of the embodiment, the head protection portion 36 and the shoulder restraint portions 37L, 37R of the protruding inflatable portion 35 made of non-woven fabric are attached to the ceiling wall 36a, 37R, respectively. When the shoulder MS or the head MH of the driver MD is received by the 37a, the sidewalls 36b, 37b are buckled to absorb the kinetic energy of the driver MD and receive the driver MD. Therefore, the driver MD can be stably protected.

The material for forming the specific expansion portion is not limited to the nonwoven fabric, and may be formed from, for example, a synthetic resin sheet having physical properties equivalent to those of the nonwoven fabric used in the embodiment. Moreover, if the above points are not taken into consideration, the specific inflating portion may be formed using a woven fabric that is set to have a higher deformation resistance than the woven fabric that constitutes the general inflating portion. Further, in the embodiment, the specific expansion portion is configured to expand so as to partially protrude from the general expansion portion. You may configure so that a part of the region arranged in the is used as a specific expansion portion.

Furthermore, in the airbag 20 of the embodiment, the projecting inflation portion 35 is configured to include the head protection portion 36 capable of protecting the head MH of the driver MD when inflation is completed. The head MH can be stably received by the projecting expansion portion 35 .

In the airbag 20 of the embodiment, the projecting inflation portion 35 as the specific inflation portion is made of non-woven fabric and is configured to have a uniform thickness. For example, if the regions of the shoulder restraint portions 37L and 37R are made thick and the region of the head protection portion 36 is made relatively thin, the thick shoulder restraint portions 37L and 37R may restrain the shoulders of the driver MD. The MS can be accurately restrained while absorbing a large amount of kinetic energy. Conversely, the thin head protection portion 36 can softly receive the head MH of the approaching driver MD. If non-woven fabric is used, it is easy to partially change the thickness, and by changing the shape and physical properties of the material, or by applying a coating agent etc. to the surface after molding, the specific expansion part It is possible to easily adjust the protected person protection performance. In the embodiment, the protruding inflatable portion 35 made of non-woven fabric is joined to the main inflatable portion 21 by sewing using a suture thread. may be applied. In the embodiment, the head protection portion 36 and the shoulder restraint portions 37L, 37R of the protruding inflation portion 35 are respectively controlled by the ceiling walls 36a, 37a arranged on the side of the driver MD, so that the shoulder portion MS of the driver MD is restrained. Alternatively, when receiving the head MH, the side walls 36b and 37b are buckling deformed to absorb the kinetic energy of the driver MD and receive the driver MD, but the ceiling walls 36a and 37a themselves are deformed. It may be configured to absorb the kinetic energy of the driver MD.

In addition, in the airbag device M of the embodiment, the wrapping material 80 that wraps the folded body 50 of the airbag 20 is also made of nonwoven fabric. As compared with the wrapping material, it is difficult to stretch, the compressed state of the folded body 50 after wrapping can be maintained, the occurrence of springback can be suppressed, and the compact state of the folded body 50 can be stabilized. can be maintained. Therefore, it is suitable for a steering wheel with a small mounting space. The shape of the wrapping material 80 is not limited to the embodiment. For example, the wrapping material 80A shown in A of FIG. A cross-shaped slit 92A or an arc-shaped slit 92B may be provided in the region, and the regions surrounded by the slits 92A and 92B may be used as door portions 93A and 93B to be opened when the airbag is inflated. Further, like the wrapping material 80C shown in FIG. 20C, the ceiling cover portion 81C may be provided with a recess from the back surface side, and the thin area where the recess is arranged may be used as the breaking portion 84C. Furthermore, when a non-woven fabric is used as the wrapping material, it is sufficient that the elongation is smaller than that of the peripheral wall constituting the body inflatable portion 21 as a general inflatable portion, and the deformation resistance need not necessarily be high.

In the embodiment, an airbag for a steering wheel for protecting a driver as a person to be protected is taken as an example, but the airbag to which the present invention can be applied is limited to this. Instead, there are passenger-side airbags that are installed in front of the passenger seat, head-protection airbags that inflate to cover the inside of the vehicle to protect the occupant's head, and walking to protect pedestrians. The present invention can be applied to airbags for persons and the like.

10... Retainer 11... Inflator 12... Bag holder 14... Air bag cover 20... Air bag 21... Body expansion part (general expansion part) 27... Driver side wall part 35... Protruding expansion part (specific expansion part) part), 36... head protection part, 37L, 37R... shoulder restraint part, MD... driver (person to be protected), H... head, W... steering wheel, M... air bag device for steering wheel.

Claims (3)

a folded body (50) in which a bag-shaped airbag (20), which is inflated so as to protect a person to be protected, is folded so as to be deployed and inflatable;
a wrapping material (80) that covers the periphery of the folded body (50) and retains the folded shape;
A bag assembly (90) comprising:
The folded body (50) includes a bottom portion (51), a ceiling portion (54) facing the bottom portion (50), and the bottom portion (50) and the ceiling portion (54). It has a three-dimensional shape with a side part (55) between
The wrapping material (80) is
The airbag (20) is made of non-woven fabric having a higher deformation resistance than the airbag (20), and is three-dimensionally molded along the outer shape of the folded body (50),
A ceiling cover portion (81) covering the ceiling portion (54) of the folded body (50), and a side cover portion (82) extending from the peripheral edge of the ceiling cover portion (81) and covering the side portions of the folded body (50). ), wherein the ceiling cover portion (81) can be opened when the airbag (20) is deployed and inflated . The wrapping material (80) has a breakable portion (84) arranged at the boundary between the ceiling cover portion (81) and the side cover portion (82) to be broken when the airbag (20) is deployed and inflated. The bag assembly (90) according to claim 1, characterized in that it is provided with a The wrapping materials (80A, 80B) are provided with slits (92A, 92B) in the areas of the ceiling cover parts (81A, 81B), and the areas surrounded by the slits (92A, 92B) are covered with door parts (93A, 92B). 93B) is configured to be opened when the airbag is deployed and inflated.

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