JP7207093B2 - Airbag - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag that is stored in a storage portion in a folded state in front of an occupant seated on a seat and inflates so as to protect the occupant.

Conventionally, as an airbag, there is an airbag for a steering wheel, which inflates in a truncated cone shape so as to cover substantially the entire upper surface of the steering wheel. Specifically, the airbag has a substantially circular body side wall portion that is arranged on the steering wheel side when inflation is completed, and a substantially circular body side wall portion that is disposed on the driver side when inflation is completed and is set larger in outer diameter than the vehicle body side wall portion. It has a circular driver side wall portion and a side wall portion connecting the vehicle body side wall portion and the driver side wall portion, and has a substantially truncated conical shape whose diameter expands toward the driver side after completion of expansion. (See Patent Document 1, for example).

Japanese Patent Application Laid-Open No. 2018-20737

However, in this conventional steering wheel airbag, when the inflation is completed, the side wall of the driver is arranged in a substantially flat shape over the entire surface, so the head of the driver as a passenger is softly protected. There was room for

SUMMARY OF THE INVENTION An object of the present invention is to provide an airbag capable of softly protecting the head of an occupant.

An airbag according to the present invention is an airbag that is stored in a storage portion in a folded state in front of an occupant seated on a seat and inflates so as to protect the occupant,
a bag body that is inflated by inflating an inflation gas therein; and a tether that is disposed in the bag body and regulates the shape of the bag body after inflation,
A configuration in which the bag main body includes a vehicle body side wall portion that is arranged on the storage portion side when inflation is completed and has an attachment portion that is attached to the storage portion, and an occupant side wall portion that is arranged on the occupant side when inflation is completed and receives the occupant. is,
The occupant side wall portion has a substantially circular outer shape and is composed of a separate base material,
a substantially annular outer peripheral edge side portion disposed on the outer peripheral edge side when expansion is completed;
a central side portion that is arranged on the central side and has a substantially circular shape when inflation is completed;
an intermediate portion arranged between the outer peripheral edge side portion and the central side portion and having a substantially annular shape, the inner edge being coupled to the outer peripheral edge of the central side portion, and the outer edge being coupled to the inner edge of the outer peripheral edge side portion;
and
A tether is disposed so as to connect the outer peripheral edge side of the central side portion and the mounting portion side,
The outer peripheral edge of the central side portion is pulled by the tether when the bag main body is completely inflated, and is disposed closer to the mounting portion than the inner edge of the outer peripheral side portion.

In the airbag of the present invention, in the occupant side wall portion, when the inflation is completed, the central side portion arranged on the central side has an outer peripheral edge closer to the attachment portion than the inner edge of the outer peripheral edge side portion arranged on the outer peripheral edge side. It will be arranged so as to be positioned at. That is, in the airbag of the present invention, in the occupant side wall portion, the intermediate portion disposed between the central side portion and the outer peripheral edge side portion is arranged between the inner edge side and the outer edge side so that the inner edge side is disposed lower than the outer edge side. is inflated toward the passenger side. When the intermediate portion in such an inflated state receives the head of the occupant, the portion between the inner edge and the outer edge is inflated toward the driver side and recessed toward the mounting portion. Looking at the cross-sectional shape from the center to the outer circumference, the action of denting the middle section between the inner and outer rims creates wrinkles. Since it is difficult for the intermediate portion itself to exhibit tension that would extend the length of the film, it can receive the occupant's head as a small reaction force. On the other hand, when the occupant's chest is received by the side of the outer peripheral edge of the airbag at the completion of inflation, the behavior of recessing the inflated side of the outer peripheral edge toward the mounting portion is the behavior of widening the outer diameter of the side of the outer peripheral edge. As a result, the internal pressure of the airbag itself is counteracted, and a reaction force is added to expand the film length on the outer edge side of the outer peripheral edge side along the circumferential direction. can be done.

Therefore, the airbag of the present invention can softly protect the occupant's head and accurately protect the occupant's upper body such as the chest, which has high kinetic energy.

Further, in the airbag of the present invention, in the intermediate portion, the width dimension between the outer edge joined to the inner edge of the outer peripheral side portion and the inner edge joined to the outer peripheral edge of the central side portion is defined as the outer periphery at the completion of inflation. If the dimension is set to be larger than the separation distance between the inner edge of the edge side portion and the outer peripheral edge of the central side portion, the intermediate portion will be positioned between the outer peripheral edge side portion and the central side portion when the inflation of the airbag is completed. Since the amount of upward projection in an annular shape can be increased, a large receiving stroke can be secured when the occupant's head is received, and the forwardly moving occupant's head can be It is possible to receive it more softly, which is preferable.

Further, in the airbag having the above configuration, the bag body has a vehicle body side wall portion, an occupant side wall portion, and a side wall portion connecting the outer peripheral edges of the vehicle body side wall portion and the occupant side wall portion, and has a completed inflation shape. is substantially columnar, when receiving the occupant, the side wall expands so as to expand the outer diameter dimension, and the kinetic energy of the occupant in the airbag can be increased, and the entire upper body of the occupant This is preferable because it enables accurate restraint.

Furthermore, if the airbag of the present invention is mounted on a steering wheel that is gripped during steering and is configured to be able to cover substantially the entire upper surface of the steering wheel when inflation is completed, the fully inflated airbag can be used by an occupant. It is preferable because the driver's head and chest can be received smoothly.

1 is a schematic plan view of a steering wheel on which a steering wheel airbag device using the airbag of the present invention is mounted; FIG. 1 is a schematic vertical cross-sectional view of a steering wheel airbag device according to an embodiment; FIG. FIG. 4 is a schematic perspective view of the airbag of the embodiment inflated by itself, viewed from the rear upper side. FIG. 4 is a schematic perspective view of the airbag of FIG. 3 as seen from the front lower side; 4 is a schematic bottom view of the airbag of FIG. 3; FIG. FIG. 6 is a cross-sectional view of the VI-VI portion of FIG. 5; FIG. 6 is a cross-sectional view of the VII-VII portion of FIG. 5; FIG. 4 is a partially enlarged schematic cross-sectional view showing a state in which the driver's side wall is flatly deployed and a state in which the inflation is completed, in the airbag of the embodiment. FIG. 3 is a plan view of the state in which base materials constituting the airbag of the embodiment are arranged. FIG. 2 is a schematic vertical cross-sectional view of the steering wheel airbag device of the embodiment in a state in which the airbag has completed inflation. FIG. 4 is a schematic diagram illustrating a state in which an inflated airbag receives a driver in the steering wheel airbag device of the embodiment;

An embodiment of the present invention will be described below with reference to the drawings. In the embodiment, an airbag 20 used in a steering wheel airbag device M as shown in FIGS. 1 and 2 will be described as an example. A steering wheel H on which an airbag device M is mounted is arranged in front of a driver MD as a passenger seated in a seat (not shown) (see FIG. 11), and as shown in FIGS. and an airbag device M arranged above the central boss portion B of the handle body 1 . In the embodiments, unless otherwise specified, the front-rear, up-down, and left-right directions are based on the straight-ahead steering of the steering wheel H mounted on the vehicle. The vertical direction along the axial direction of the shaft SS is defined as the front-rear direction of the vehicle, and the left-right direction of the vehicle, which is the direction orthogonal to the axis of the shaft SS, is defined as the left-right direction. It shows the direction.

As shown in FIGS. 1 and 2, the handle body 1 includes a grip portion G gripped by the driver MD, a boss portion B arranged near the center and fastened to the shaft SS, the grip portion G and the boss portion B. and a spoke portion S that connects the The gripping portions G (GL, GR) are disposed on the left and right sides of the boss portion B. When the handle body 1 is viewed from above, the front and rear central sides are positioned outward on the left and right. It is curved in a substantially arc shape so as to protrude outward. The spoke portions S (SL, SR) are arranged so as to be inclined with respect to the front-rear direction so as to connect the rear ends of the gripping portions G (GL, GR) and the boss portions B. As shown in FIG. 1 and 2, the handle body 1 is arranged so as to connect the grip portion G, the boss portion B, and the spoke portion S, and a metal core 3 made of a metal such as an aluminum alloy. I have it. A portion of the core metal 3 where the gripping portion G is located and a portion of the spoke portion S on the side of the gripping portion G are covered with a synthetic resin coating layer 5 . 2, a boss 4 made of steel for inserting the shaft SS and fastening it with a nut N is disposed at the boss portion B of the core bar 3. As shown in FIG. Further, a synthetic resin lower cover 6 covering the lower part of the boss portion B is provided on the lower portion of the handle body 1 . In this embodiment, as shown in FIG. 1, the steering wheel H (handle body 1) has a width dimension W1 in the front-rear direction that is smaller than a width dimension W2 in the left-right direction when viewed from above in a straight-ahead steering state. configured to be set. Specifically, compared to a general steering wheel (steering wheel) having an annular ring (gripping portion), the steering wheel H has a front region and a rear region that are notched so that it can move in the front-rear direction. The width dimension on the side is set small.

As shown in FIG. 1, the airbag device M is arranged on a boss portion B positioned substantially in the center of the front, rear, left, and right of the handle body 1 (handle H), and as shown in FIG. The airbag 20, the inflator 11 for supplying inflation gas to the airbag 20, the case 12 as a storage part for storing and holding the airbag 20 and the inflator 11, and the folded airbag 20 are covered. An airbag cover 14 and a retainer 10 for attaching the airbag 20 and the inflator 11 to the case 12 are provided. That is, the airbag 20 is configured such that an attachment portion 28 (which coincides with the retainer 10), which will be described later, is attached to a position substantially centered in front, rear, left, and right of the handle body 1 (see FIG. 1).

The inflator 11 includes, as shown in FIG. 2, 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 case 12. As shown in FIG. The flange portion 11c is formed with through holes (not shown) through which respective bolts (not shown) of the retainer 10 are passed.

As shown in FIG. 2, the case 12 as a storage portion is made of sheet metal, and has a substantially rectangular plate-like bottom wall portion 12a to which the inflator 11 is inserted from below and attached, and extends vertically from the outer peripheral edge of the bottom wall portion 12a. and a peripheral wall portion 12b. A rearwardly extending mounting piece 12c is formed at the upper end of the peripheral wall portion 12b (see FIG. 1), and a mounting board (not shown) of a horn switch mechanism is mounted on the mounting piece 12c. The case 12 is fixed to the core metal 3 of the handle body 1 by using this mounting board (not shown) or another mounting member, and the airbag device M is attached to the boss portion of the handle body 1 already mounted on the shaft SS. It will be mounted on top of B. A side wall portion 14c of the airbag cover 14 is attached to the peripheral wall portion 12b of the case 12 using rivets 15 or the like (see FIG. 2). In the case of the embodiment, the airbag 20 and the inflator 11 are attached by bolts (not shown) of the retainer 10 arranged in the airbag 20, and these bolts (not shown) are attached to the peripheral edge of the inflow opening 27 of the airbag 20. A mounting hole 28a formed in the mounting portion 28, the bottom wall portion 12a of the case 12, and the flange portion 11c of the inflator 11 are passed through and fastened with a nut (not shown), thereby removing the bottom wall portion 12a of the case 12. attached to the

The airbag cover 14 is made of synthetic resin, and includes a ceiling wall portion 14a covering the upper side of the airbag 20 housed in the case 12, and a substantially rectangular cylindrical side wall portion 14c extending 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 forward and backward by the inflating airbag 20 to open.

The airbag 20 is configured to inflate so as to cover the entire upper surface of the steering wheel H so as to protect the driver MD as a passenger (see two-dot chain lines in FIGS. 1 and 2 and FIG. 10). As shown in FIGS. 3 to 7, a bag-like bag main body 21, a regulating cloth 45 for regulating inflation gas flowing into the bag main body 21, and a shape of the bag main body 21 that is disposed in the bag main body 21 to complete the expansion of the bag main body 21. and a tether 48 for regulating.

1 and 2 and FIG. 10, the bag body 21 is disposed so as to cover substantially the entire upper surface of the handle body 1 when inflation is completed. A vehicle body side wall portion 23 arranged on the side (storage portion side), a driver side wall portion 35 (passenger side wall portion) arranged on the driver MD side as a passenger when inflation is completed, the vehicle body side wall portion 23 and the driver side wall It has a side wall portion 30 that connects the outer peripheral edges 24 and 35a with the portion 35, and has a substantially columnar shape when the expansion is completed.

The vehicle body side wall portion 23 is formed from a vehicle body side panel 55, which will be described later, and in the case of the embodiment, as shown in FIG. It has a substantially trapezoidal shape. Specifically, the vehicle body side wall portion 23 has a front edge 24a, a left edge 24b, and a right edge 24c that are curved so as to protrude slightly outward, and a rear edge 24d that is substantially straight in the left-right direction. It is configured as a shape. The vehicle body side wall portion 23 is configured to cover the entire upper surface of the handle body 1 when the bag body 21 is fully inflated (see the two-dot chain line in FIG. 1 and FIG. 10). The main body portion 11a of the inflator 11 is inserted from below at a position on the front side of the center of the inflator 11, and the inflow opening 27 for introducing the inflation gas discharged from the gas discharge port 11b of the inflator 11 into the interior is approximately It is formed with a circular opening (see FIGS. 4 and 5). In addition, in the bag body 21 of the embodiment, the peripheral edge of the inflow opening 27 in the vehicle body side wall portion 23 serves as a mounting portion 28 that is mounted to the case 12 (storage portion). Four mounting holes 28a for inserting bolts are formed (see FIGS. 4 and 5).

As described above, the vehicle body side wall portion 23 is configured such that the inflow opening 27 is positioned forward of the center in the front-rear direction, and is substantially bilaterally symmetrical when viewed from above when the bag main body 21 is fully inflated. In addition, the amount of protrusion from the handle body 1 is configured such that the amount of protrusion T2 in the rearward direction is larger than the amount of protrusion T1 in the left-right direction (see FIG. 1). More specifically, FIG. 5 shows the outer shape of the vehicle body side wall 23 when the airbag 20 is viewed from below when inflation is completed (same as when the airbag 20 is fully inflated and viewed from above). , the rear edge 24d is positioned behind an arc L1 (see the two-dot chain line in FIG. 5) that passes through the left edge 24b or the right edge 24c with the center C of the inflow opening 27 (mounting portion 28) as the center. At the same time, the regions near the intersections of the trailing edge 24d, the left edge 24b, and the right edge 24c (the left end 24da and the right end 24db of the trailing edge 24d) are moved radially (left The protruding portions 25, 25 protruding obliquely rearward and obliquely rearward to the right are configured to be positioned outward from the arc L1. In the case of the embodiment, the vehicle body side wall portion 23 (vehicle body side panel 55) has a width dimension W3 (see FIG. 9) on the left-right direction side in a flat unfolded state, and a width dimension W2 on the left-right direction side of the handle body 1 ( 1), and the separation distance T3 between the center C of the inflow opening 27 and the rear edge 24d is set to about 10/9 of the distance between the center C of the inflow opening 27 and the left edge 24b (right edge 24c). It is set to about 7/6 of the separation distance T4 (see FIG. 9). Further, the vehicle body side wall portion 23 (vehicle side panel 55) has a separation distance T5 between the center C of the inflow opening 27 and the front edge 24a, which is 4 of the separation distance T3 between the center C of the inflow opening 27 and the rear edge 24d. /7 (see FIG. 9).

A driver side wall portion 35 as an occupant side wall portion has a substantially circular outer shape. As shown in FIGS. 3, 6, and 7, the driver side wall portion 35 is composed of a separate base material, and has a substantially annular outer peripheral edge side portion 37 disposed on the side of the outer peripheral edge 35a when inflation is completed. , a central side portion 38 that is arranged on the central side and has a substantially circular shape when inflation is completed, and a substantially annular intermediate portion 39 that is arranged between the outer peripheral edge side portion 37 and the central side portion 38. It is configured. The outer peripheral edge side portion 37 is configured to have a substantially constant width dimension over the entire circumference. In the case of the embodiment, as shown in FIGS. 6 and 7, the intermediate portion 39 is arranged so as to protrude toward the driver side (upward) beyond the outer peripheral edge side portion 37 and the central side portion 38 when the inflation of the bag body 21 is completed. It is arranged in a convex shape. As shown in FIG. 3, when the bag main body 21 is completely inflated, the intermediate portion 39 protrudes in an annular shape with a substantially constant amount of protrusion over the entire circumference, and is arranged so as to generate wrinkles in the region. be. The outer peripheral edge 38a of the central side portion 38 is pulled toward the mounting portion 28 by a tether 48. When the bag main body 21 is fully inflated, the outer peripheral edge 38a of the central side portion 38 is pulled closer to the attaching portion 28 than the inner edge 37a of the outer peripheral side portion 37. It is configured to be arranged on the side of the handle body 1 . That is, in the airbag 20 of the embodiment, when the bag main body 21 is completely inflated, the central side portion 38 is arranged at a position closer to the attachment portion 28 than the outer peripheral edge side portion 37, and the central side portion 38 is surrounded by , and an intermediate portion 39 projecting toward the driver side from the outer peripheral edge side portion 37 is arranged so as to surround the central side portion 38 over the entire circumference (see FIGS. 6 and 7).

The driver side wall portion 35 joins the inner edge 37a (60a) of the outer peripheral edge side portion 37 (an outer peripheral edge portion constituting panel 61 to be described later) and the outer edge 39a (67a) of the intermediate portion 39 (an intermediate portion constituting panel 67 to be described later). By connecting the outer peripheral edge 38a (64a) of the central side portion 38 (body portion 64 of the central side portion constituting panel 63 described later) and the inner edge 39b (67b) of the intermediate portion 39 (intermediate portion constituting panel 67), The central side portion 38, the intermediate portion 39, and the outer peripheral edge side portion 37 are concentrically aligned with each other. In the case of the embodiment, the outer diameter dimension of the driver side wall portion 35 (the outer diameter dimension of the outer peripheral edge portion constituting panel 61) D1 is the center C and the rear edge of the inflow opening 27 in the vehicle body side wall portion 23 (vehicle side panel 55). 24d is set to about 2.8 times the separation distance T3 (see FIG. 9). That is, the radius of the driver side wall portion 35 is set to be slightly larger than the separation distance T3 between the center C of the inflow opening 27 in the vehicle body side wall portion 23 and the rear edge 24d.

The side wall portion 30, which connects the outer peripheral edges 24, 35a of the vehicle body side wall portion 23 and the driver side wall portion 35, has a substantially cylindrical shape when the expansion is completed, and the upper edge 30a at the time of the completion of the expansion is the driver side wall portion 35. The lower edge 30b is joined to the outer peripheral edge 35a, and the lower edge 30b at the time of completion of inflation is joined to the outer peripheral edge 24 of the vehicle body side wall portion 23. As shown in FIG. The side wall portion 30 is configured such that the height dimension is substantially constant over the entire circumference. In the side wall portion 30, in the region arranged on the front side when inflation is completed, vent holes 31 for discharging surplus inflation gas that has flowed into the bag main body 21 are formed at two substantially symmetrical circular vent holes 31. (see FIGS. 4 and 10).

In the bag main body 21 of the embodiment, a mounting portion 28 (inflow opening 27) attached to the vicinity of the center of the handle body 1 is arranged in a region where the vehicle body side wall portion 23 is on the front side of the front-rear center. The driver side wall portion 35 has a substantially circular outer shape, and the outer peripheral edge 38 a of the center side portion 38 arranged on the center side is pulled toward the attachment portion 28 by a tether 48 . The side wall portion 30, which connects the outer peripheral edges 24, 35a of the vehicle body side wall portion 23 and the driver side wall portion 35, has a constant height dimension over the entire circumference. Therefore, as shown in FIG. 10, the bag main body 21 of the embodiment is inflated so that the central side portion 38 is positioned directly above the inflator 11 (right above the mounting portion 28), so that the bag main body 21 inflates in the front-rear direction at the time of completion of inflation. In the cross-section along the T3 (inflow opening 27 The distance between the center C of the opening 27 and the rear edge 24d) and T5 (the distance between the center C of the inflow opening 27 and the front edge 24a) is shortened by the dimensional difference (see FIG. 7), and the rear end at the completion of inflation The rear end region 22 on the 21a side expands thicker than the region on the front end 21b side when expansion is completed (see FIG. 10).

As shown in FIGS. 6 and 7, the rectifying cloth 45 arranged in the bag main body 21 is arranged so as to cover the upper side of the inflow opening 27 when the bag main body 21 is completely inflated. It has a substantially cylindrical shape with both ends in the front-rear direction opened so that the inflation gas that flows in from the opening can be rectified to both front-rear sides. In the case of the embodiment, the rectifying cloth 45 is composed of the rectifying cloth material 70 shown in FIG. The regulating cloth material 70 includes a central portion 70a, and substantially fan-shaped left and right portions 70b and 70c projecting left and right from the central portion 70a. The side portion 70a is joined (sewn) to the peripheral edge (mounting portion 28) of the inflow opening 27, and the left side portion 70b and the right side portion 70c are sewn (joined) to each other at their outer peripheral edges. A rectifying cloth 45 having openings is formed.

The tether 48 arranged in the bag main body 21 is arranged so as to connect the mounting portion 28 side and the outer peripheral edge 38a side of the central side portion 38 of the driver side wall portion 35, as shown in FIGS. It regulates the separation distance between the mounting portion 28 and the central side portion 38 at the completion of inflation, and in the case of the embodiment, is formed at four substantially radial locations centered on the inflow opening 27 . Specifically, the tether 48 is strip-shaped, and is arranged at four points, obliquely forward left, obliquely forward right, obliquely rearward left, and obliquely rearward right of the inflow opening 27 . In the embodiment, the tether 48 is composed of a central side panel 63 forming the central side 38 and a tether base material 75, as shown in FIG. The central side component panel 63 includes a substantially circular body portion 64 that constitutes the central side portion 38 and four tether component portions 65 radially extending from the outer edge 64 a of the body portion 64 . . The tether base material 75 includes a substantially circular connecting portion 76 coupled to the attachment portion 28 side, and four strip-shaped tether forming portions 77 radially extending from the outer peripheral edge 76 a of the connecting portion 76 . Openings (not shown) are formed in the connecting portion 76 so as to correspond to the inflow opening 27 and the mounting hole 28a. It is configured to be coupled to the peripheral mounting portion 28 . The tether forming portion 77 is formed corresponding to the tether forming portion 65 of the central side portion forming panel 63 . In the embodiment, each tether 48 is formed by sewing (bonding) the ends 65a and 77a of the tether-constituting portions 65 and 77 to each other using a suture thread (see FIGS. 6 and 7). ). When the airbag 20 is completely inflated, the tether 48 pulls the central side portion 38 toward the attachment portion 28 so that the outer peripheral edge 38a of the central side portion 38 is pulled from the inner edge 37a of the outer peripheral side portion 37. are set to dimensions so that they are positioned on the mounting portion 28 side (lower side).

As shown in FIG. 9, the bag main body 21 of the embodiment has a vehicle body side panel 55 that constitutes the vehicle body side wall portion 23, a driver side panel 60 that constitutes the driver side wall portion 35, and a side wall structure that constitutes the side wall portion. The panel 57 and the like.

As shown in FIGS. 5 and 9, the vehicle body side panel 55 constituting the vehicle body side wall portion 23 has an external shape substantially identical to that of the vehicle body side wall portion 23, and has a substantially trapezoidal external shape as described above. there is The vehicle body side panel 55 has an outer edge 55a that is joined to the lower edge 57b of the side wall constituting panel 57 over the entire circumference. The vehicle body side panel 55 is formed with an inflow opening 27 and a mounting hole 28a.

The side wall forming panel 57 forming the side wall portion 30 has an upper edge coupled to the outer edge 61a of the outer peripheral edge forming panel 61 of the driver side panel 60 rather than a lower edge 57b coupled to the outer edge 55a of the vehicle body side panel 55. While the length of 57a is lengthened, the width dimension is made constant, and it is made into the shape of a slightly curved belt (refer to Drawing 9). The peripheral length of the lower edge 57b of the side wall component panel 57 is set to be substantially the same as the peripheral length of the outer edge 55a of the vehicle body side panel 55, and the peripheral length of the upper edge 57a is set to the peripheral length of the outer edge 51a of the outer peripheral edge component panel 61. are set to be approximately the same. This side wall constituting panel 57 constitutes the cylindrical side wall portion 30 by connecting the longitudinal side edges 57c and 57d to each other. 61a. A vent hole 31 is formed in the side wall constituting panel 57 . The width dimension W5 of the side wall constituting panel 57 is set to about 3/5 of the outer diameter dimension D1 of the driver side wall portion 35 (the outer diameter dimension of the outer peripheral edge portion constituting panel 61) (see FIG. 9). .

The outer peripheral edge component panel 61 has a substantially annular shape whose width dimension is constant over the entire circumference, and the outer edge 61a is connected to the upper edge 57a of the side wall component panel 57, and the inner edge 61b is connected to the middle component panel 67 over the entire length. is coupled with the outer edge 67a of the . The peripheral length of the inner edge 61 b of the outer peripheral edge component panel 61 is set to be substantially the same as the peripheral length of the outer edge 67 a of the intermediate component panel 67 .

A central side panel 63 forming the central side 38 includes a substantially circular main body 64 forming the central side 38 and a tether forming part 65 radially extending from an outer edge 64 a of the main body 64 . . The body portion 64 of the central side panel 63 has an outer diameter D2 set smaller than the inner diameter d1 of the opening of the outer peripheral panel 61 (see FIG. 9). In the case of the embodiment, the outer diameter dimension D2 of the main body portion 64 is set to about 7/9 of the inner diameter dimension d1 of the opening portion of the outer peripheral edge portion constituting panel 61 . The body portion 64 of the central side component panel 63 is configured such that the outer edge 64a is joined to the inner edge 67b of the intermediate component panel 67 . The peripheral length of the outer edge 64a of the body portion 64 is set substantially equal to the peripheral length of the inner edge 67b of the panel 67 constituting the intermediate portion.

As shown in FIG. 9, the panel 67 forming the intermediate portion 39 has an outer edge 67b coupled to the outer edge 64a of the body portion 64 forming the central side portion 38. The length of the outer edge 67a coupled to the inner edge 61b of the peripheral edge component panel 61 is increased, and the width dimension is substantially constant to form a curved strip. The intermediate portion forming panel 67 forms the substantially annular intermediate portion 39 by connecting the longitudinal side edges 67c and 67d to each other. The width dimension W4 (see FIG. 9) between the outer edge 67a and the inner edge 67b of the intermediate portion constituting panel 67 is the outer diameter dimension D2 of the main body portion 64 constituting the central side portion 38 and the opening of the outer peripheral edge portion constituting panel 61. The inner diameter dimension d1 of the part and the dimensional difference T6 (matches the separation distance T7 between the inner edge 37a of the outer peripheral side portion 37 and the outer peripheral edge 38a of the central side portion 38 in the flattened state, see FIGS. 8 and 9 ) and larger than the separation distance T8 (see FIG. 6) between the inner edge 37a of the outer peripheral side portion 37 and the outer peripheral edge 38a of the central side portion 38 at the completion of inflation. there is In the case of the embodiment, the width W4 of the intermediate panel 67 is set to about seven times the distance T7 between the outer peripheral edge side 37 and the center side 38 in the flatly unfolded state. The intermediate portion constituting panel 67 is formed by connecting the inner edge 67b to the outer edge 64a of the main body portion 64 constituting the central side portion 38, and by connecting the outer edge 67a to the inner edge 61b of the outer peripheral portion constituting panel 61. Since the intermediate portion 39 is formed, the intermediate portion 39 protrudes largely from between the outer peripheral edge side portion 37 and the central side portion 38 in a state in which the driver side wall portion 35 is flattened. (See A in FIG. 8). Further, even when the airbag 20 completes inflation, the intermediate portion 39 is disposed so as to protrude further toward the driver side (upward) than the outer peripheral edge side portion 37 (FIGS. 6, 7 and 8). B).

Next, mounting of the airbag 20 on the vehicle will be described. First, the airbag 20 is folded so that it can be stored in the case 12 with the retainer 10 arranged inside so that bolts (not shown) protrude from the mounting holes 28a. 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 the air are connected by using bolts and nuts (not shown) projecting from the bottom wall portion 12a. Attach the bag 20 to the case 12 . Furthermore, if the case 12 is covered with the airbag cover 14, the airbag cover 14 is attached to the case 12 using rivets 15 or the like, and then the horn switch mechanism (not shown) is attached to the attachment piece 12c of the case 12, An airbag device M can be assembled. The airbag device M can be mounted on a vehicle by attaching it to the steering wheel main body 1, which has been fastened to the shaft SS in advance, using a mounting board or mounting member (not shown) of the horn switch mechanism. .

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 airbag 20 is inflated by the inflow of the inflation gas, and the door portion of the airbag cover 14 is expanded. 14b, 14b are pushed open to protrude from the case 12, and as shown in two-dot chain lines in FIGS. 1 and 2 and FIG.

In the airbag 20 of the embodiment, in the driver side wall portion 35 as the occupant side wall portion, the central side portion 38 arranged on the central side has the outer peripheral edge 38a arranged on the side of the outer peripheral edge 35a when inflation is completed. It is arranged so as to be positioned closer to the mounting portion 28 than the inner edge 37a of the outer peripheral edge side portion 37 provided. That is, in the airbag 20 of the embodiment, in the driver side wall portion 35, the intermediate portion 39 arranged between the central side portion 38 and the outer peripheral edge side portion 37 is arranged such that the inner edge 39b side is arranged below the outer edge 39a side. As a result, the space between the inner edge 39b and the outer edge 39a expands toward the driver MD side (upward). When the intermediate portion 39 in such an inflated state receives the head MH of the driver MD, the space between the inner edge 39b and the outer edge 39a is inflated toward the driver MD and then recessed toward the mounting portion 28. However, looking at the cross-sectional shape from the center to the outer peripheral side of the driver side wall portion 35, the behavior is such that the intermediate portion 39 is recessed so as to wrinkle between the inner edge 39b and the outer edge 39a (B in FIG. 8). ), it is difficult for the intermediate portion 39 itself to exert a tension that expands the film length by simply recessing the intermediate portion 39 against the internal pressure of the airbag 20 itself. can receive the head MH of the driver MD. On the other hand, as shown in FIG. 11A, when the outer peripheral edge side portion 37 of the airbag 20 at the completion of inflation receives the chest MB of the driver MD, the inflated state of the outer peripheral edge side portion 37 is placed on the mounting portion 28 side. The denting behavior is a behavior of widening the outer diameter dimension of the outer peripheral edge side portion 37 to counteract the internal pressure of the airbag 20 itself, and the outer edge side of the outer peripheral edge side portion 37 (the outer peripheral edge 35a side of the driver side wall portion 35). The large reaction force can receive the chest MB of the driver MD with high kinetic energy.

Therefore, the airbag 20 of the embodiment can softly protect the head MH of the driver MD, and accurately protect the upper body such as the chest MB of the driver MD having high kinetic energy.

Further, in the airbag 20 of the embodiment, the width dimension W4 of the intermediate portion 39 (intermediate portion constituting panel 67) is between the inner edge 37a of the outer peripheral side portion 37 and the outer peripheral edge 38a of the central side portion 38 when inflation is completed. is set to be larger than the separation distance T8, when the inflation of the airbag is completed, the intermediate portion 39 moves upward in an annular shape between the outer peripheral edge side portion 37 and the central side portion 38. The amount of protrusion can be increased, a large receiving stroke can be secured when the head MH of the driver MD is received, and the head MH of the driver MD moving forward can be further moved by the intermediate portion 39 projecting upward. You can take it softly. In particular, in the airbag 20 of the embodiment, the width dimension W4 of the intermediate portion 39 is set to be approximately seven times the separation distance T7 between the outer peripheral edge side portion 37 and the central side portion 38 in a flatly deployed state. Therefore, the intermediate portion 39 can be made to protrude greatly from the outer peripheral edge side portion 37 and the central side portion 38, and the intermediate portion 39 is arranged so as to cause wrinkles in the region. The head MH of the driver MD can be softly and stably protected. In the embodiment, in the airbag 20 at the completion of inflation, the separation distance T8 on the front-rear direction side between the inner edge 37a of the outer peripheral edge side portion 37 and the outer peripheral edge 38a of the central side portion 38 is equal to the inner edge 37a of the outer peripheral edge side portion 37. and the outer peripheral edge 38a of the central side portion 38 (see FIG. 6).

If such a point is not considered, the width dimension W4 of the intermediate portion 39' may be set substantially equal to the separation distance T8, as indicated by the two-dot chain line in FIG. 8B. In this configuration, the intermediate portion 39' is arranged to gently connect the outer peripheral side portion 37 and the central side portion 38. As shown in FIG.

In the airbag 20 of the embodiment, the intermediate portion 39 has an annular shape and is arranged at a position corresponding to the head MH of the driver MD moving forward as shown in FIG. 11B. It is possible to smoothly protect the head MH of the driver MD. In addition, the intermediate portion 39 also prevents the head MH of the driver MD, who moves forward from the waist with the waist restrained by the seat belt (not shown), as shown in FIG. 11A. can be accepted with certainty.

In addition, in the airbag 20 of the embodiment, the bag body 21 includes the vehicle body side wall portion 23, the driver side wall portion 35, and the side wall connecting the outer peripheral edges 24, 35a of the vehicle body side wall portion 23 and the driver side wall portion 35 to each other. It has a portion 30 and has a substantially columnar shape when the expansion is completed. Therefore, when the driver is received, the side wall portion 30 is inflated so as to widen the outside diameter, and the amount of kinetic energy of the driver MD absorbed by the airbag 20 can be increased. can be constrained precisely. If such a point is not taken into account, an airbag may be used in which the outer peripheral edges of the vehicle body side wall portion and the driver side wall portion, both of which have substantially circular outer shapes, are joined together. .

In particular, in the embodiment, the airbag 20 inflated into a substantially columnar shape is arranged so as to protrude greatly rearward from the handle body 1 when the handle body 1 is viewed from above (two points in FIG. 1). See the chain line), when viewed from the side, the rear end 21a protrudes further rearward than the handle body 1, and has a region protruding below the rear end 1a of the handle body 1. Therefore, even if the driver side wall portion 35 of the airbag 20 after completion of inflation receives the forward moving driver MD and is pushed by the driver MD to move, the rear end 1a of the steering wheel main body 1 does not move. As shown in FIG. 11B, the rear end side region 22 (part on the side of the rear end 21a) protruding downward is inflated, and is positioned between the rear end 1a of the handle body 1 and the abdomen MA of the driver MD. can be accurately interposed between them, and the abdomen MA of the driver MD can be appropriately protected.

In the steering wheel H on which the airbag 20 of the embodiment is mounted, the grip portions GL and GR that are gripped during steering are arranged only on the left and right sides of the boss portion B. It is a configuration that is not arranged in front of the . Therefore, in the bag main body 21 at the completion of inflation, the front end 21b side portion arranged on the front side of the boss portion B cannot secure the reaction force from the handle main body 1 side when receiving the driver MD. However, since the bag main body 21 of the embodiment is inflated into a substantially columnar shape with a thick wall, when the upper body of the driver MD moving forward is received by the driver side wall portion 35, the driver side wall portion 35 is While being pushed by the driver MD and moving substantially along the vertical direction, the portion of the bag body 21 on the front end 21b side is further thickened by being partially compressed, and the driver MD moves forward. MH can be protected by this thick portion (see FIG. 11B). Therefore, even in a configuration in which the handle body 1 is mounted on the handle body 1 that does not have a grip portion in the front region, the front end 21b side portion can appropriately restrain the head MH of the driver MD moving forward. . That is, the airbag 20 of the embodiment has a front region and a rear region that are notched compared to a general steering wheel (steering wheel) having an annular ring (grip portion). Even with a configuration in which it is mounted on the steering wheel H, which is set to have a small width dimension in the front-rear direction, the abdomen MA and the head MH of the driver MD can be restrained appropriately.

The airbag 20 of the embodiment is mounted on the steering wheel H that is gripped during steering, and covers substantially the entire upper surface of the steering wheel H when inflation is completed. The head MH and chest MB of the driver MD as a passenger can be received smoothly. In the embodiments, the airbag used in the steering wheel airbag device is exemplified, but the airbag of the present invention is not limited to the steering wheel airbag. The airbag of the present invention can also be applied, for example, to an airbag for a mid-mount type front passenger airbag device that is arranged in front of an occupant seated on the front passenger seat. If the height dimension is changed, it can be applied to a top mount type front passenger seat airbag that inflates so as to substantially follow the occupant side wall in the vertical direction.

DESCRIPTION OF SYMBOLS 20... Airbag 21... Bag main body 23... Vehicle body side wall part 28... Mounting part 30... Side wall part 35... Driver side wall part 37... Outer peripheral side part 37a... Inner edge 38... Central side part, 38a Outer peripheral edge 39 Intermediate portion 39a Outer edge 39b Inner edge 48 Tether H Handle M Airbag device.

Claims (5)

An airbag that is stored in a storage portion in a folded state in front of an occupant seated on a seat and inflates so as to protect the occupant,
The bag includes a bag body that is inflated by inflating an inflation gas, and a tether that is disposed in the bag body and regulates the shape of the bag body when the inflation is completed,
a vehicle body side wall portion in which the bag main body is arranged on the side of the storage portion when inflation is completed and has a mounting portion attached to the storage portion; and
The occupant side wall portion has a substantially circular outer shape and is composed of a separate base material,
a substantially annular outer peripheral edge side portion disposed on the outer peripheral edge side when expansion is completed;
a central side portion that is arranged on the central side and has a substantially circular shape when inflation is completed;
An intermediate portion arranged between the outer peripheral edge side portion and the central side portion and having a substantially annular shape, the inner edge being coupled to the outer peripheral edge of the central side portion, and the outer edge being coupled to the inner edge of the outer peripheral edge side portion. When,
and
The tether is disposed so as to connect the outer peripheral edge side of the central side portion and the mounting portion side,
The outer peripheral edge of the central side portion is pulled by the tether when the bag body is completely inflated, and is disposed closer to the attachment portion than the inner edge of the outer peripheral side portion ,
When the bag main body is fully inflated, the central side portion is arranged at a position closer to the mounting portion than the outer peripheral edge side portion, and the intermediate portion protrudes toward the occupant from the outer peripheral edge side portion. The airbag is arranged so as to surround the entire circumference of the central side portion . The intermediate portion has a width dimension between the outer edge coupled to the inner edge of the outer peripheral edge side portion and the inner edge coupled to the outer peripheral edge of the central side portion, and the width dimension of the outer peripheral edge side portion at the completion of inflation. 2. The airbag according to claim 1, wherein the dimension is set to be larger than the separation distance between the inner edge and the outer peripheral edge of the central side portion. The bag main body has the vehicle body side wall portion, the occupant side wall portion, and a side wall portion connecting the outer peripheral edges of the vehicle body side wall portion and the occupant side wall portion, and has a substantially columnar shape after inflation. 3. The airbag according to claim 1 or 2, characterized in that: 4. The airbag according to any one of claims 1 to 3, wherein the airbag is mounted on a steering wheel that is gripped during steering, and is configured to be able to cover substantially the entire upper surface of the steering wheel when inflation is complete. airbag. The airbag is mounted on a handle that is gripped during steering, and is configured to be able to cover substantially the entire upper surface of the handle when inflation is complete ,
4. The airbag according to claim 3, wherein the width of the steering wheel in the front-rear direction in the straight-ahead steering state is set smaller than the width in the left-right direction.

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