Airbag device

Abstract

To provide an airbag device which can be attached easily and enables an airbag to protect a head of an operator from a steering part of a handle properly when its expansion is completed.SOLUTION: In an airbag device 30, an expanded airbag 40 is arranged between a steering part 4 of a handle 3 and an operator MD during an operation. A storage portion 29 in which the airbag is folded is arranged as a portion of a lap belt part 22 in a seat belt 20 disposed at a driver seat 10 on which the operator is seated so that the expanded airbag is deployed and expanded upward from the storage portion to be arranged between the steering part and an upper half body MU of the operator. When the expansion is completed, the airbag 40 includes a handle support surface 50, which is supported by an operator facing surface 4a of the handle, at a front surface 40c side and further includes a head receiving expansion part 54, which may receive a head MH of the operator at the rear surface side, at its upper part 40a side.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an airbag device that protects a driver by disposing an inflated airbag between the driver and a steering portion of a steering wheel that the driver holds when activated. [Background technology]

[0002] Conventionally, airbag devices that, when activated, place an inflated airbag between the driver and the steering portion of the steering wheel held by the driver include a folded airbag that is stored near the left-right center of the seat of the driver's seat and, when activated, protrudes upward from a storage location between the driver's left and right thighs to place the inflated airbag between the driver and the steering portion of the steering wheel (see, for example, Patent Document 1).

[0003] In addition, there has been a system in which a shape-retaining lap bar is connected to both sides of the driver's seat and disposed in front of the lap belt portion of the seat belt worn by a seated driver, and a folded airbag is stored in the lap bar.When activated, the airbag protrudes upward from the storage portion of the lap bar, and an inflated airbag is disposed between the steering portion of the steering wheel and the driver (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-104592 A [Patent Document 1] JP 2013-139184 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the airbag device of Patent Document 1, the airbag protrudes upward between the thighs of the seated driver, and if the driver's posture is poor, there is a risk that the airbag will deploy and inflate on the back side of the steering part of the steering wheel, which is the side opposite to the driver's side, and in that case, the head of the driver moving forward cannot be properly protected from the steering part of the steering wheel. Note that the steering part of the steering wheel is rotated around a steering central axis arranged in a rearward upward direction, and the driver-facing surface facing the driver in a direction approximately perpendicular to the steering central axis on the upper surface side of the steering part is arranged inclined rearward downward, and the lower end side of the steering part is arranged close to the driver's side. Therefore, in the airbag device of Patent Document 1, if the inflating airbag interferes with the driver's thighs and the protruding direction is deviated, there is a risk that the airbag will enter the back side of the steering part. Furthermore, in the airbag device of Patent Document 2, a lap bar must be set in front of the seated driver in addition to the seat belt, which makes it difficult to install and takes time and effort to install.

[0006] The present invention is devised to solve the above-mentioned problems, and has an object to provide an airbag device which is easy to install and which, when fully inflated, can adequately protect the driver's head from the steering portion of the steering wheel. [Means for solving the problem]

[0007] The airbag device according to the present invention is configured such that a steering portion of a steering wheel which is gripped by a driver and rotated around a steering central axis has a driver-facing surface facing the driver in a direction substantially perpendicular to the steering central axis on the upper surface side, the driver-facing surface being inclined downward toward the rear, An airbag device configured to dispose an inflated airbag between the steering unit and a driver when activated, a storage portion in which the airbag is folded is disposed as a portion of a lap belt portion of a seat belt disposed in a driver's seat in which a driver sits, and the airbag is deployed and inflated upward from the storage portion when inflated, and disposed between the steering portion and the upper body of the driver, The airbag when fully inflated is characterized in that it has a handle support surface on the front side that is supported on the driver-facing surface of the handle, and a head-receiving inflation portion on the upper side that is capable of receiving the driver's head on the rear side.

[0008] In the airbag device according to the present invention, a storage portion for storing a folded airbag is disposed in a portion of the lap belt portion of the seat belt worn by the driver seated in the driver's seat. Therefore, when the driver fastens the seat belt and positions the lap belt portion of the seat belt in front of the waist of the seated driver, the storage portion for the airbag of the airbag device can be easily attached to the driver. After the airbag storage portion is positioned in front of the driver's waist, when the airbag device is activated, the airbag deploys and inflates upward from the storage portion when inflated and is positioned between the steering portion of the steering wheel and the upper body of the driver, and the front side steering wheel support surface is positioned on the side of the steering portion of the steering wheel facing the driver, and a head receiving expansion portion capable of receiving the driver's head on the rear side is positioned on the upper side, completing the inflation.Therefore, even if the upper body of the driver moving forward tries to interfere with the steering portion of the steering wheel, the steering wheel support surface is supported on the side of the steering portion of the steering wheel facing the driver, and the head receiving expansion portion of the airbag, which has a secured reaction force, can accurately receive and protect the head. In addition, since the lap belt portion of the seat belt worn by the driver is positioned rearward and downward from the rear end of the steering portion of the steering wheel, the storage portion of the airbag is also positioned rearward and downward from the rear end of the steering portion of the steering wheel.This means that the airbag, which deploys and inflates upward from the storage portion, is less likely to interfere with the steering portion and is smoothly positioned between the steering portion of the steering wheel and the upper body of the driver.

[0009] Therefore, the airbag device according to the present invention can be easily installed, and the airbag can adequately protect the driver's head from the steering portion of the steering wheel when fully inflated.

[0010] In the airbag device according to the present invention, it is desirable that the airbag be configured such that, when fully inflated, its thickness in the front-to-rear direction gradually decreases from the upper end side to the storage area at the lower end side.

[0011] In such a configuration, as the longitudinal distance between the driver-facing surface of the steering wheel's steering portion and the front side of the seated driver's upper body gradually decreases from top to bottom, the airbag inflates to close the space between the steering wheel's steering portion and the driver's upper body, enabling the airbag to quickly and effectively receive and protect almost the entire upper body, including the driver's head, as it moves forward, with its rear side.

[0012] In this case, it is desirable that the airbag, when fully inflated, has an outer shape viewed from the left and right side that is approximately triangular, with two sides that approach each other from the steering wheel support surface on the front side and the driver restraint surface on the rear side that supports the driver toward the lower end side of the storage area, and an upper side that connects the steering wheel support surface and the driver restraint surface near their upper ends.

[0013] In this configuration, the driver restraint surface of the airbag when fully inflated is substantially flat and does not have any partially protruding portions, allowing a wide area to softly receive the driver's upper body, including the head. Also, the airbag when fully inflated is substantially triangular when viewed from the side, that is, the airbag is substantially triangular in shape consisting of the steering wheel support surface, the driver restraint surface, and the upper surface connecting the upper ends of the steering wheel support surface and the driver restraint surface, each of which is substantially flat, and the upper surface side of the airbag is not curved in a shape that bulges significantly upward, so that the volume can be reduced and the airbag can be configured compactly.

[0014] Furthermore, in the airbag device of the present invention, it is desirable that when inflation is complete, a lower region of the handle support surface of the airbag extending from the driver-facing surface of the handle toward the storage location is prevented from protruding forward beyond the rear end of the steering section, and is formed as a protrusion-suppressing surface portion that is gently connected to the storage location.

[0015] In this configuration, when the airbag deploys and inflates upward from the storage portion of the lap belt portion during activation, the airbag itself at the time of full inflation does not have a portion that protrudes forward beyond the rear end of the steering portion in the lower region that is connected from the driver-facing side of the steering wheel support surface to the storage portion side, so it does not enter and get caught on the back side of the steering portion (the surface opposite the driver-facing surface). Therefore, the airbag quickly deploys and inflates to its fully inflated shape, and the head-receiving inflation portion can be disposed on the upper side. [Brief description of the drawings]

[0016] [Figure 1] 1 is a right side view of a driver's seat illustrating a state before activation of an airbag device according to an embodiment of the present invention. [Diagram 2] 1 is a front view of a driver's seat illustrating a state before the airbag device of the embodiment is activated. [Diagram 3] 1 is a left side view of a driver's seat illustrating a state before the airbag device of the embodiment is activated. FIG. [Figure 4] 4 is a schematic cross-sectional view of a storage portion of the airbag according to the embodiment, which corresponds to the portion IV-IV in FIG. 2. [Diagram 5] FIG. 2 is a right side view of the airbag device according to the embodiment when it is activated. [Figure 6] 2 is a schematic perspective view showing a state where the airbag in the airbag device according to the embodiment has completed inflation by itself; FIG. [Figure 7] FIG. 2 is a plan view of the components forming the airbag, the conduit portion, and the belt attachment portion used in the embodiment. [Figure 8] FIG. 11 is a right side view of a modified example of the airbag device of the embodiment during activation. [Figure 9] 9 is a schematic perspective view showing the airbag in the airbag device shown in FIG. 8 when the airbag has completed inflation by itself. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] An embodiment of the present invention will be described below with reference to the drawings. As shown in Figs. 1 to 3, an airbag device 30 of the embodiment is disposed in a driver's seat 10 arranged behind a steering wheel 3. The driver's seat 10 is a seat on which a driver MD sits, and includes a backrest portion 12 and a seat portion 14. The airbag device 30 of the embodiment, together with a seat belt 20, constitutes a driver protection device 18 that protects the driver MD.

[0018] The steering wheel 3 is connected to the rear end of a steering shaft (not shown) that constitutes a steering central axis 2 of the steering device 1 that steers the vehicle, and is configured to include a substantially annular steering unit 4 that is gripped by a driver MD to steer the steering wheel 3. When steering the vehicle, the steering unit 4 is rotated and steered around the rotation central axis 2, and the upper surface side of the steering unit 4 is disposed along a direction substantially perpendicular to the steering central axis 2, and since the steering central axis 2 is inclined upward toward the rear, it constitutes a driver-facing surface 4a that faces the driver MD as a rear-downward inclined surface.

[0019] The seat belt 20 is arranged so as to be retractable from a retractor 23 disposed on the upper right side 12a of the backrest portion 12 on one side of the driver's seat 10 in the left-right direction (the right side in this embodiment) so as to restrain the driver MD seated in the driver's seat 10, and the end 20a extending downward from the retractor 23 is connected to an anchor member 25 on the right side portion 16 of the seat portion 14 of the driver's seat 10. When the driver MD is seated in the driver's seat 10, the tongue 28 arranged between the anchor member 25 and the retractor 23 is fastened to the buckle 27 arranged on the left side 15 of the seat portion 14 while unwinding the seat belt 20 from the retractor 23. This causes the portion of the seat belt 20 from the tongue 28 to the anchor member 25 to become a lap belt portion 22 that covers the front of the driver MD's waist MW and suppresses forward movement of the driver MD's waist MW, and the portion of the seat belt 20 from the tongue 28 to the retractor 23 to become a shoulder belt portion 21 that suppresses forward movement of the driver MD's upper body MU, including the chest MB.

[0020] 3 is a pressing member that holds the seat belt 20 so that it can be inserted and does not come off the right side 16 of the seat 14. The buckle 27 is provided with a release button (not shown), and when the fastened tongue 28 is to be released, the tongue 28 can be removed from the buckle 27 by pressing the release button. The retractor 23 is further configured to have a pretensioner that stops the seat belt 20 from being pulled out if the seat belt 20 is suddenly pulled out, and can retract the pulled-out seat belt 20 if a vehicle collision or the like occurs.

[0021] When the seat belt 20 is worn by the driver MD, the vicinity of the center in the left-right direction on the upper surface 22a side of the lap belt portion 22 is a storage portion (which may be called a mounting portion or a placement portion in the case of the embodiment) 29 for the folded airbag 40 in the airbag device 30. Since the lap belt portion 22 of the seat belt 20 worn by the driver MD is positioned rearward and downward from the rear end 4c of the steering portion 4 of the steering wheel 3, the storage portion 29 for the airbag 40 is also positioned rearward and downward from the rear end 4c of the steering portion 4 of the steering wheel 3.

[0022] The airbag device 30 is configured to include an airbag 40 that deploys and inflates upward from the storage area 29 when inflation gas G flows in, and is positioned between the steering unit 4 and the upper body MU of the driver MD, an inflator 31 that supplies inflation gas G (see Figures 5 and 6) to the airbag 40, a conduit portion 58 that guides the inflation gas G from the inflator 31 to the inlet portion 56 of the airbag 40, a belt attachment portion 62 that attaches the folded airbag 40 to the storage area 29 of the lap belt portion 22, and a breakable cover 64 that covers the folded airbag 40 together with the belt attachment portion 62 (see Figures 2 and 4).

[0023] The inflator 31 includes a generally cylindrical inflator body 32 that discharges inflation gas G, and a pipe section 33 that protrudes from the inflator body 32 and is bent into a generally L-shape, and is attached and fixed to the rear side of the seat section 14 of the driver's seat 10 (see FIGS. 1 and 2). A tip section 58b of a conduit section 58 that is connected to the airbag 40 is fitted to the pipe section 33, and is further fastened and connected to the pipe section 33 by a clamp 34.

[0024] The base portion 58a side of the conduit portion 58 is connected to an inlet portion 56 for allowing the inflating gas G of the airbag 40 to flow in (see FIG. 6). A communication port 59 corresponding to the inlet 56a of the inlet portion 56 is opened on an upper surface (front surface) 58aa side of the base portion 58a.

[0025] The belt attachment portion 62 is connected to the underside (back surface) 58ab side of the base portion 58a of the conduit portion 58, and is attached to the lap belt portion 22 by wrapping the storage portion (attachment portion) 29 of the lap belt portion 22 as a circular ring (see Figure 4).

[0026] The belt attachment portion 62 is tubular and has an insertion hole 62a through which the lap belt portion 22 passes, and is attached to a lower surface 58ab of the base portion 58a of the conduit portion 58.

[0027] The cover 64 is formed from a flexible, breakable sheet material such as cloth, and is arranged to cover the folded airbag 40, the base portion 58a of the conduit portion 58, and the belt attachment portion 62 through which the lap belt portion 22 is inserted.

[0028] The airbag 40 is folded and stored with the vicinity of the center in the left-right direction on the upper surface 22a side of the portion that becomes the lap belt portion 22 of the seat belt 20 as a storage portion (attachment portion) 29. The airbag 40 is made of flexible woven fabric such as polyester. Like the airbag 40, the conduit portion 58 and the belt attachment portion 62 are also made of flexible woven fabric such as polyester.

[0029] When the airbag 40 is fully inflated, as shown in Figures 1 to 3 and 5, it is configured to have a handle support surface 50 on the front 41c side that is supported by the driver-facing surface 4a of the steering section 4 of the handle 3, and a head receiving inflation portion 54 on the upper portion 40a side that is capable of receiving the head MH of the driver MD on the rear surface 40d side.

[0030] More specifically, in the case of the embodiment, when the airbag 40 is fully inflated, the peripheral wall 41 is configured to include a substantially rectangular front wall portion 42, a substantially rectangular rear wall portion 44, substantially triangular left and right side wall portions 46 (L, R) between the front wall portion 42 and the rear wall portion 44, and a substantially elongated upper wall portion 48, and is substantially triangular prism-shaped when viewed from the left and right direction (see Figures 5 and 6).

[0031] In other words, the airbag 40 when fully inflated has an outer shape as viewed from the left and right direction, which is a substantially triangular shape having two sides SF, SB approaching each other from the handle support surface 50 on the front surface 40c side and the driver restraint surface 53 on the rear surface 40d side that receives the driver MD toward the lower ends 50ba, 53ba of the storage area 29, and an upper side SU connecting the handle support surface 50 and the driver restraint surface 53 near the upper ends 50aa, 53aa. Therefore, in the embodiment, the airbag 40 when fully inflated is configured such that the thickness dimension TL in the front-rear direction (see Figs. 1 and 5) gradually decreases from the upper end 40aa side to the storage area 29 on the lower end 40ba side.

[0032] The vicinity of the lower end 40ba of the airbag 40 constitutes an inlet section 56 having an inlet 56a for allowing the inflation gas G to flow into the airbag 40 (see FIG. 6). In the present embodiment, two inlets 56a are provided side by side in the left-right direction, and a base section 58a of a conduit section 58 is connected to the inlet section 56 so that a communication port 59 communicates with each inlet 56a.

[0033] Furthermore, in the case of the embodiment, when the airbag 40 is fully inflated while mounted in the vehicle, a lower region (lower part) 50b of the steering wheel support surface 50 of the airbag 40 extending from the driver-facing surface 4a of the steering wheel 3 toward the storage area 29 is prevented from protruding forward beyond the rear end 4c of the steering section 4, forming a protrusion suppression surface portion 51 that is gently connected to the storage area 29 (see Figure 5).

[0034] The upper portion 50a side of the handle support surface 50 is disposed so that an upper end 50aa extends upward beyond the driver-facing surface 4a of the handle 3.

[0035] In addition, when the airbag 40 is fully inflated, the mutual intersection angle θ (see FIG. 5) between the handle support surface 50 and the driver restraint surface 53 is formed to be approximately 30° within the range of 10 to 50° (preferably within the range of 20 to 40°).

[0036] 7, the bag base fabric 70 forming the airbag 40 includes a substantially rectangular front wall portion 71 constituting the front wall portion 42 of the airbag 40, a substantially rectangular rear wall portion 72 continuing along the longitudinal direction of the front wall portion 71 and constituting the rear wall portion 44 of the airbag 40, a substantially rectangular upper wall portion 75 continuing along the longitudinal direction of the front wall portion 71 and constituting the upper wall portion 48 of the airbag 40, and substantially triangular side wall portions 73, 74 continuing on both the left and right sides of the front wall portion 71, respectively, and constituting the left and right side wall portions 46 (L, R) of the airbag 40. Inflow ports 56a, 56a are opened near the boundaries between the front wall portion 71 and the rear wall portion 72.

[0037] The conduit portion 58 is formed by sewing together the outer peripheries of a front material 77 and a back material 78 which form the upper and lower sides. A communication port 59 is formed in the front material 77, and a connecting portion 78a which is connected to the belt attachment portion 62 is provided in the back material 78.

[0038] The belt attachment portion 62 is formed from a single sheet-like attachment member 80, and end edges 80a, 80a of the attachment member 80 are sewn together to wrap the lap belt portion 22 and attach it to the lap belt portion 22. The portion indicated by reference symbol 80b is a connecting portion that is connected to the connecting portion 78a of the conduit portion 58.

[0039] The airbag 40 is manufactured while joining the conduit portion 58. That is, the peripheral edge of the communication openings 59, 59 of the front material 77 of the conduit portion 58 is sewn to the peripheral edge of the inlet 56a, 56a of the bag base fabric 70 provided with the inlet 56a, the side edges 73a, 74a of the left and right side wall portions 73, 74 of the bag base fabric 70 are sewn to the side edges 72a, 72b of the rear wall portion 72, the edges 73b, 74b of the left and right side wall portions 73, 74 are sewn to the side edges 75a, 75b of the upper wall portion 75, and the edge 75c of the upper wall portion 75 is sewn to the edge 72c of the rear wall portion 72, whereby the peripheral wall 41 of the airbag 40 can be formed. Then, the outer peripheral edges of the back material 78 of the conduit portion 58, with the connecting portion 80b of the mounting member 80 connected to the connecting portion 78a, and the front material 77 of the conduit portion 58, connected to the peripheral wall 41 of the airbag 40, are sewn together to form the conduit portion 58, thereby forming the airbag 40 with the conduit portion 58 connected. Then, the airbag 40 is folded, and the folded body 85 is attached to the storage portion 29 of the lap belt portion 22. In this attachment, the belt attachment portion 62, in a state in which the edges 80a, 80a of the attachment member 80 are not sewn together, is disposed so as to be wrapped around the storage portion (attachment portion) 29 of the lap belt portion 22 of the seat belt 20, and the edges 80a, 80a of the attachment member 80 are sewn together to form an annular insertion hole 62a to form the belt attachment portion 62, while attaching the belt attachment portion 62 to the storage portion (attachment portion) 29 of the lap belt portion 22, and then the folded airbag 40 (folded body 85) is wrapped together with the belt attachment portion 62 and the base portion 58a of the conduit portion 58 with the cover 64, whereby the folded body 85 can be attached to the storage portion 29 of the seat belt 20. Furthermore, by connecting the tip portion 58b of the conduit portion 58 extending from the airbag 40 to the pipe portion 33 extending from the inflator body 32 of the inflator 31, the airbag device 30 can be mounted on the driver's seat 10.

[0040] In the airbag device 30 of the embodiment, a storage portion 29 that stores a folded airbag 40 is disposed in a portion of the lap belt portion 22 of the seat belt 20 worn by the driver MD seated in the driver's seat 10. Therefore, when the driver MD wears the seat belt 20 and positions the lap belt portion 22 of the seat belt 20 in front of the waist MW of the seated driver MD, the storage portion 29 of the airbag 40 of the airbag device 30 can be easily attached to the driver MD. Then, after the storage portion 29 of the airbag 40 is disposed in front of the waist MW of the driver MD, when the vehicle collides and the airbag device 30 is activated, the airbag 40 deploys and inflates upward from the storage portion 29 and is disposed between the steering portion 4 of the steering wheel 3 and the upper body MU of the driver MD, and as shown in Fig. 5, the steering wheel support surface 50 on the front surface 40c side is disposed on the driver-facing surface 4a side of the steering portion 4 of the steering wheel 3, and the head receiving expansion portion 54 capable of receiving the head MH of the driver MD on the rear surface 40d side is disposed on the upper portion 40a side, completing the inflation. Therefore, even if the upper body MU of the driver MD moving forward tries to interfere with the steering portion 4 of the steering wheel 3, the steering wheel support surface 50 is supported on the driver-facing surface 4a of the steering portion 4 of the steering wheel 3, and the head receiving expansion portion 54 of the airbag 40, which has secured a reaction force, can adequately receive and protect the head MH. Since the storage portion 29 of the airbag 40 in the lap belt portion 22 is positioned rearward and downward from the rear end 4c of the steering portion 4 of the handlebars 3, the airbag 40 which deploys and inflates upward from the storage portion 29 is unlikely to interfere with the steering portion 4, and is smoothly positioned between the steering portion 4 of the handlebars 3 and the upper body MU of the driver MD.

[0041] Therefore, the airbag device 30 of the embodiment can be easily attached, and the airbag 40 can adequately protect the head MH of the driver MD from the steering portion 4 of the steering wheel 3 when fully inflated.

[0042] In the airbag device 30 of this embodiment, the airbag 40 is configured such that the thickness dimension TL in the front-rear direction of the airbag 40 at the time of complete inflation gradually decreases from the upper end 40aa side to the storage portion 29 on the lower end 40ba side.

[0043] Therefore, in the embodiment, the airbag 40 inflates so as to block the space SP (see FIG. 1) between the steering part 4 of the steering wheel 3 and the upper body MU of the driver MD, in response to the longitudinal distance FL between the driver-facing surface 4a of the steering part 4 of the steering wheel 3 and the front side of the upper body MU of the seated driver MD gradually decreasing from the top to the bottom (see FIG. 1 and FIG. 5). Thus, the airbag 40 is able to quickly and suitably receive and protect substantially the entire upper body MU, including the head MH of the driver MD as it moves forward, on its rear surface 40d side.

[0044] In this case, in the embodiment, the airbag 40 when fully inflated has an outer shape viewed from the left and right side that is approximately triangular with two sides SF, SB that approach each other from the handle support surface 50 on the front surface 40c side and the driver restraint surface 53 that receives the driver MD on the rear surface 40d side toward the lower end 40ba on the storage area 29 side, and an upper side SU that connects the handle support surface 50 and the driver restraint surface 53 near their upper ends 50aa, 53aa (see Figure 5).

[0045] Therefore, in the embodiment, the driver restraint surface 53 of the airbag 40 at the time of completion of the inflation is substantially planar, and does not have any partially protruding portion, and can softly receive the upper body MU including the head MH of the driver MD over a wide area. In addition, the airbag 40 at the time of completion of the inflation is substantially triangular when viewed from the side, that is, the steering wheel support surface 50, the driver restraint surface 53, and the upper surface 40e connecting the upper ends 50aa, 53aa of the steering wheel support surface 50 and the driver restraint surface 53, each of which is substantially planar, and the upper surface 40e side of the airbag 40 is not curved so as to bulge significantly upward, so that the volume can be reduced and the airbag 40 can be configured compactly.

[0046] In addition, in this embodiment, the airbag 40 is formed so that the mutual intersection angle θ between the handle support surface 50 and the driver restraint surface 53 at the time of completion of inflation is approximately 30° within the range of 10 to 50° (preferably within the range of 20 to 40°).

[0047] Therefore, in the case of the embodiment, since the intersection angle θ between the handle support surface 50 and the driver restraint surface 53 is not less than 10°, the thickness dimension in the front-rear direction of the airbag 40 at the time of complete inflation can be ensured, and the upper body of the driver MD can be received and protected with good cushioning. Also, since the intersection angle between the handle support surface 50 and the driver restraint surface 53 does not exceed 50°, the amount of rearward protrusion of the upper end 40aa side of the airbag 40 at the time of complete inflation can be suppressed, and the upper body MU including the head of the driver MD can be received with good cushioning.

[0048] Furthermore, in the airbag device 30 of the embodiment, a lower region 50b of the handle support surface 50 of the airbag 40 when inflation is complete, which extends from the driver-facing surface 4a of the handle 3 toward the storage area 29, is prevented from protruding forward beyond the rear end 4c of the steering section 4, and is formed as a protrusion suppression surface portion 51 that is gently connected to the storage area 29.

[0049] Therefore, in the embodiment, when the airbag 40 deploys and inflates upward from the storage portion 29 of the lap belt portion 22 during activation, the airbag 40 itself at the time of complete inflation does not have a portion that protrudes forward beyond the rear end 4c of the steering portion 4 in the lower region 50b that is connected from the driver-facing surface 4a side of the steering wheel 3 to the storage portion 29 side of the steering wheel support surface 50, and therefore does not enter and get caught on the back surface 4b side (the surface opposite to the driver-facing surface 4a) of the steering portion 4. Therefore, the airbag 40 quickly deploys and inflates to the fully inflated shape, and the head-receiving inflation portion 54 can be disposed on the upper portion 40a side.

[0050] Although the airbag 40 in the embodiment has a substantially triangular prism shape when viewed from the side, the airbag when fully inflated may have a steering wheel support surface on the front side that is supported by the surface of the steering wheel facing the driver, and a head receiving inflatable portion on the upper side that can receive the driver's head on the rear side. Therefore, for example, like the airbag 40A of the airbag device 30A shown in Figs. 7 and 8, the airbag may have a shape that has a substantially rectangular parallelepiped front inflatable portion 90 and a substantially oval spherical rear inflatable portion 91 on the upper rear side of the front inflatable portion 90 when fully inflated.

[0051] In this airbag 40A, the front surface 90a of the substantially rectangular parallelepiped front inflation section 90 at the time of inflation becomes the steering wheel support surface 50A supported by the driver-facing surface 4a of the steering section 4 of the steering wheel 3, and the rear inflation section 91 forms the head receiving inflation section 54A capable of receiving the head MH of the driver MD on the rear side. The inflation gas G from the inflator 31 flows through the communication port 59 of the conduit section 58 and the inlet 56a into the front inflation section 90 of the airbag 40A, and then flows through the communication port 92 provided at the top of the front inflation section 90 into the rear inflation section 91, thereby inflating the airbag 40A.

[0052] In the embodiment, the seat belt 20 is attached to the seat, and the retractor 23 that retracts the seat belt 20 and the anchor member 25 to which the tip 20a of the seat belt 20 is connected are arranged on the right side of the driver's seat (seat) 10. However, the retractor 23 that retracts the seat belt 20 and the anchor member 25 to which the tip 20a of the seat belt 20 is connected may be arranged on the vehicle body side, i.e., near the pillar portion, and more specifically, the seat belt 20 may be retracted from the upper side of the B pillar to the side of the driver's seat 10 and the tip 20a of the seat belt 20 may be connected to the anchor member 25 arranged near the lower part of the B pillar, so that the seat belt 20 is attached to the vehicle body. [Explanation of symbols]

[0053] 2...Steering center axis, 3...Steering wheel, 4...Steering section, 4a...(upper surface) driver-facing surface, 4b...(lower surface) rear surface, 4c...rear end, 10...(seat) driver's seat, 20...seat belt, 21...shoulder belt section, 22...lap belt section, 29...(mounting portion, arrangement portion) storage portion, 30, 30A...airbag device, 40, 40A...airbag, 40a...upper portion, 40aa...upper end, 40b ...lower part, 40ba...lower end, 40c...front surface, 40d...rear surface, 50, 50A...steering wheel support surface, 50aa...upper end, 50b...(lower region) lower part, 50ba...lower end, 51...protrusion suppression surface portion, 53...driver restraint surface, 53aa...upper end, 53ba...lower end, 54, 54A...head receiving expansion portion, 90...front side expansion portion, 90a...(steering wheel support surface) front side, 91...(head receiving expansion portion) rear side expansion portion, SF...(front) side, SB...(rear) side, SU...top side, TL...(front-to-back) thickness dimension, MD...driver, MU...upper body, MH...head.

Claims

1. A steering portion of a steering wheel which is gripped by a driver and rotated around a steering central axis is arranged so that a driver-facing surface facing the driver in a direction substantially perpendicular to the steering central axis on the upper surface side is inclined downward toward the rear, An airbag device configured to dispose an inflated airbag between the steering unit and a driver when activated, a storage portion in which the airbag is folded is disposed as a portion of a lap belt portion of a seat belt disposed in a driver's seat in which a driver sits, and the airbag is deployed and inflated upward from the storage portion when inflated, and disposed between the steering portion and the upper body of the driver, the airbag when fully inflated comprises, on its front side, a handle support surface that is supported on the driver-facing surface of the handle, the handle support surface forming the front surface of a substantially rectangular parallelepiped front inflatable portion, and, on its upper rear side, a head receiving inflatable portion that is capable of receiving the driver's head, the head receiving inflatable portion forming the rear surface of a substantially elliptical rear inflatable portion that protrudes rearward from the rear surface of the front inflatable portion, an inflator that releases inflation gas to be supplied to the airbag to inflate the airbag is attached to an underside of a seat portion of the driver's seat;

2. a conduit portion for guiding the inflation gas discharged from the inflator to the airbag; a belt attachment portion for attaching the folded airbag to the lap belt; a cover for covering the belt attachment portion and the folded airbag; 10. The airbag device according to claim 1, further comprising:

3. 3. The airbag device according to claim 1, wherein a lower region of the steering wheel support surface of the airbag when the airbag is fully inflated, which extends from the driver-facing surface of the steering wheel toward the storage location, is prevented from protruding forward beyond the rear end of the steering section, and serves as a protrusion suppression surface portion that is gently connected to the storage location.

Images