JP2018075970A - Driver's seat airbag and driver's seat airbag device - Google Patents

Abstract

An airbag for a driver's seat in which the distance from the stitched portion to the rear panel rear end is larger than the distance from the stitched portion between the front panel and the rear panel to the front panel occupant surface in the completed inflation state, and the inflation is completed Provided is an airbag for a driver's seat that is excellent in form stability of a rear panel in a state.
A driver's seat airbag 1 is formed by stitching a front panel 2 and a rear panel 3 together. Cutouts 4 are provided at three or more positions on the periphery of the rear panel 3. By sewing the side edges 4a and 4b of the cutout portion 4, the rear panel 3 is formed into a bowl shape. The outer peripheral edge of the bowl-shaped rear panel 3 and the outer peripheral edge of the front panel 2 are stitched together.
[Selection] Figure 1

Description

  The present invention relates to an airbag and an airbag device for restraining an occupant at the time of a car collision, and more particularly to an airbag and an airbag device for a driver's seat.

  The airbag device for the driver's seat provided on the steering wheel operates the inflator (gas generator) to eject gas in the event of an emergency such as a vehicle collision, supplies gas to the airbag, and operates the airbag with the steering wheel. It is configured to be deployed with a seat occupant.

  2. Description of the Related Art As a driver's seat airbag, one in which peripheral portions of a front panel and a rear panel are stitched together is known.

  Patent Literature 1 describes a driver's seat airbag provided with a cutout portion that has a substantially V-shaped shape from the periphery of the rear panel toward the center of the rear panel. In the state where the airbag for a driver's seat in Patent Document 1 is completely inflated, compared to the distance from the stitched portion between the front panel and the rear panel to the front panel front surface (the most occupant surface), the rear panel rear end (front panel center portion) The distance to) is large. The notches are provided at two locations in the circumferential direction of the rear panel.

  Patent Document 2 describes a driver's seat airbag having a conical rear portion, which is manufactured by providing a single V-shaped notch on the rear panel and stitching it.

  Patent Document 3 describes that a tuck extending in the radial direction (referred to as “wrinkle” in Patent Document 1) is formed by pinching and sewing the peripheral edge of the rear panel near the vent hole. Has been. This tack is for reducing the opening area of the vent hole in the early stage of inflation of the driver's seat airbag. In Patent Document 3, tacks are provided at two locations in the circumferential direction of the rear panel.

Japanese Patent Laid-Open No. 2006-141279 US Pat. No. 8,608,199 JP2015-58919A

  In the airbag for a driver's seat disclosed in Patent Document 1, V-shaped notches are provided at two locations facing the diameter direction of the rear panel, so that the shape of the rear panel in the inflated state is short in the diameter direction. , It tends to be an elliptical cone having a major axis in the orthogonal direction, and the stability of the expanded form is insufficient.

  In Patent Document 2, since the tack portion is provided only in the vicinity of the periphery of the rear panel, the inflation shape of the driver's seat airbag is substantially the same on the front panel side and the rear panel side.

  The present invention provides an airbag for a driver's seat having a large distance from the stitched portion to the rear panel rear end compared to the distance from the stitched portion between the front panel and the rear panel to the front panel occupant surface when the inflation is completed. An object of the present invention is to provide a driver's seat airbag that is excellent in form stability on the rear panel side in a completed state.

  The driver's seat airbag of the present invention is a driver's seat airbag in which the peripheral edges of the front panel and the rear panel are connected to each other. The rear panel has a peripheral length for reducing the circumferential length at three or more locations on the peripheral edge. A length reduction part is provided.

  In one aspect of the present invention, the peripheral length reducing portion is a notch portion provided from the periphery of the rear panel toward the center side, and the sides of the notch portion are coupled to each other.

  In one aspect of the present invention, the circumferential length reducing portion is a tack portion.

  In one aspect of the present invention, a first tether is provided that connects the occupant-facing surface of the driver airbag and the rear end of the driver airbag. In one aspect of the invention, the first tether is configured to increase its length when a predetermined tension or more is applied.

  In one aspect of the present invention, the notch has a narrow portion having a smaller interval between the side edges than the center side of the rear panel at a midway portion in the radial direction of the rear panel. A constriction is formed in the driver's seat airbag.

  In one aspect of the present invention, a second tether for reducing the diameter of the constricted portion is provided.

  In one embodiment of the present invention, the area of the rear panel inside the suture line between the front panel and the rear panel is 1.1 to 1.3 times the area of the front panel inside the suture line, preferably 1.15. ~ 1.2 times.

  The airbag apparatus for driver seats of this invention has the airbag for driver seats of this invention, and the inflator which expands this airbag for driver seats.

  In the driver's seat airbag according to the present invention, three or more circumferential length reduction portions are provided on the peripheral edge portion of the rear panel, so that the circumferential length reduction amount by one circumferential length reduction portion does not become excessive. Therefore, it is excellent in the form stability on the rear panel side in the expansion completed state.

  The airbag for a driver's seat according to the present invention has a rear panel in which the circumference of the rear panel is reduced by the circumference reduction portion to form a bowl shape, and the airbag at the time of completion of inflation is not increased without increasing the diameter of the airbag at the time of completion of inflation. The thickness can be increased.

It is a top view of the panel of the airbag for driver's seats concerning an embodiment. It is a perspective view of the completion state of expansion of a driver's seat airbag concerning an embodiment. It is the III-III sectional view taken on the line of FIG. It is a longitudinal cross-sectional view in the inflation completion state of the airbag for driver's seats of FIGS. It is a top view of the rear panel which concerns on another embodiment. It is a perspective view of the rear panel which concerns on another embodiment. It is the VII-VII sectional view taken on the line of FIG. FIG. 6 is a longitudinal sectional view of a driver seat airbag according to still another embodiment in a state where inflation has been completed. It is a front view of a tether belt. It is a top view of the rear panel of another embodiment. It is a longitudinal cross-sectional view in the inflation completion state of the airbag for driver's seats using the rear panel of FIG. It is a top view of the rear panel of another embodiment. FIG. 13 is a longitudinal sectional view of the driver's seat airbag using the rear panel of FIG. 12 in an inflated state.

  Hereinafter, embodiments will be described with reference to the drawings.

  1 to 4 show a driver airbag 1 according to the first embodiment. The airbag 1 includes a front panel 2 that constitutes an occupant facing surface and a rear panel 3 that constitutes a rear surface opposite to the occupant facing surface. The front panel 2 is a circular panel (base fabric).

  The rear panel 3 is provided with notches 4 at four locations on the peripheral edge of a circular panel. The notch 4 is provided at an equally divided position in the circumferential direction of the rear panel 3. In this embodiment, the cutout 4 is V-shaped and has a pair of side edges 4 a and 4 b that are closer to the center of the rear panel 3.

  An inflator opening 5 is provided at the center of the rear panel 3, and a small hole 6 for inserting a bolt is provided around the inflator opening 5. A vent hole 7 is provided on the center side of the predetermined distance from the periphery of the rear panel 3. The front panel 2 is circular. The area of the rear panel 3 inside the suture line between the front panel 2 and the rear panel 3 is 1.1 to 1.3 times the area of the front panel 2 inside the suture line, particularly 1.15 to 1.2. It is preferable that it is double.

  The rear panel 3 is formed into a hook shape by sewing the side edges 4 a and 4 b of the notch portion 4 with a suture thread 8. The diameter of the outer peripheral end of the bowl-shaped rear panel 3 is substantially the same as the diameter of the circular front panel 2. The driver's seat airbag 1 is constructed by sewing the peripheral edge of the bowl-shaped rear panel 3 and the peripheral edge of the front panel 2 with a suture thread 9 (see FIG. 4).

Since the rear airbag 3 has a bowl shape, the driver's seat airbag 1 has a distance L ₁ from the stitched portion of the rear panel 3 and the front panel 2 to the front surface of the front panel in the inflated state as shown in FIG. compared with, a large distance L ₂ to the airbag 1 rear driver's seat from the suture engaging portion. Therefore, the expansion thickness L ₁ + L ₂ of the driver's seat airbag 1 is larger than the expansion thickness of the driver's seat airbag using a circular panel having the same diameter as the front panel as the rear panel. L ₂ is preferably 1.5 to 4 times, particularly 2 to 3 times, L ₁ .

  Further, this driver's seat airbag 1 is provided with four notches 4 in the rear panel 3, so that it has an inflated configuration on the rear panel 3 side as compared to a driver seat airbag having only two notches. Excellent stability.

  In the above embodiment, the rear panel 3 is provided with the notches 4 at four locations, but may be provided at three locations like the driver airbag 10 of FIG. Also in FIG. 5, the notch 4 is provided at the circumferentially equal position of the rear panel 3. Other configurations of the driver's seat airbag 10 are the same as those of the driver's seat airbag 1, and the same reference numerals indicate the same parts. Although not shown, the notch 4 may be provided at five or more locations. The number of notches 4 is preferably about 3-6. The depth of the notch 4 (the length in the radial direction of the rear panel 3) is preferably 30 to 75%, particularly 50 to 60% of the radius of the rear panel 3, but is not limited thereto.

  In the above embodiment, the cutout 4 is V-shaped, but may be U-shaped, semicircular or semi-elliptical, and may be Ω-shaped with a narrow inlet side.

  In the above embodiment, the rear panel 3 is provided with the notches 4 and the sides 4a and 4b of the notches 4 are stitched to form the rear panel 3 in a bowl shape. However, as with the rear panel 3A in FIG. By providing the tack portions 11 at three or more locations on the periphery of the circular panel where no is provided, it may be formed into a bowl shape.

  The tack portion 11 is formed by a part of the peripheral edge of the circular panel being pushed out to the center side of the rear panel 3 </ b> A and stitching the root portion of the picked-up portion with the suture thread 12.

  In FIG. 6, although the tack part 11 is provided in four places, three places or five places or more may be sufficient. As for the number of the tack parts 11, about 3-6 pieces are preferable.

  In the present invention, a first tether 13 that connects the peripheral portion of the inflator opening 5 of the rear panel 3 and the occupant-facing surface of the front panel 2 may be provided as shown in the driver airbag 1 ′ of FIG. 8. The tether 13 is attached to the front panel 2 and the rear panel 3 with sutures 13a and 13b.

  The first tether may be of a type that has a short length in the initial stage of inflation of the driver airbag and increases in a late stage. FIG. 9 shows an example of such a tether.

  The first tether 14 of FIG. 9 is provided with a large width portion 14a extending in a direction orthogonal to the longitudinal direction at a middle portion in the longitudinal direction, and the large width portion 14a is orthogonal to the longitudinal direction. A cleavable portion 14b extending in the direction is provided.

  Since the tension applied to the tether 14 is small at the beginning of the inflation of the driver airbag, the cleavable portion 14b is not cleaved and the total length of the tether 14 is relatively short. In the later stage of expansion approaching completion of expansion, the tension applied to the tether 14 increases, the cleavable portion 14b is cleaved, and the total length of the tether 14 increases.

  A first tether capable of increasing the length other than the tether provided with the cleavable portion may be used. For example, although not shown, the middle part of the tether may be folded and stitched with a tear seam. In this case, the tear seam is not cut at the initial stage of expansion, and the tether is relatively short. As the tension applied to the tether increases later in the expansion, the tear seam tears and the tether length increases.

  10 and 11 show a driver's seat airbag 18 according to still another embodiment, FIG. 10 is a plan view of the rear panel, and FIG. 11 is a longitudinal section of the driver's seat airbag in the inflated state. FIG.

  The airbag 18 includes a front panel 19 constituting an occupant facing surface and a rear panel 20 constituting a rear surface opposite to the occupant facing surface. The front panel 19 is a circular panel (base fabric).

  The rear panel 20 is provided with notches 21 and 22 at four locations on the periphery of a circular panel. The notches 21 and 22 are provided at four equal positions in the circumferential direction of the rear panel 20. The two first cutouts 21 and 21 face each other in the diameter direction of the rear panel 20. The two second cutouts 22 and 22 are opposed to each other in the diameter direction of the rear panel 20. In this embodiment, the second cutout 22 is V-shaped and has a pair of side sides 22 a and 22 b that are closer to the center of the rear panel 20.

  The first notch 21 has a pair of side edges 21A and 21B. The side edges 21A and 21B are curved, and the side edges 21A and 21B are close to each other in the middle of the rear panel 20 in the radial direction. As a result, the first cutout portion 21 is formed with a rear portion 21a on the center side of the rear panel 20, an inlet portion 21c on the inlet side, that is, the outer peripheral side of the rear panel 20, and a narrow width portion 21b therebetween. . The minimum width of the narrow portion 21b is smaller than the maximum width of the back portion 21a.

  An inflator opening 25 is provided at the center of the rear panel 20, and a small hole 26 for inserting a bolt is provided around the inflator opening 25. A vent hole 27 is provided on the center side of the predetermined distance from the periphery of the rear panel 20.

  In this embodiment, one or more (for example, two in the orthogonal direction) second tethers 23 extending in the radial direction of the rear panel 20 are provided. Both ends of the tether 23 are sewn to the rear panel 20 with sutures 23a. The sewing position between the end portion of the tether 23 and the rear panel 20 is the same radius as the notch portion 22 b with respect to the center of the rear panel 20 in the radial direction of the rear panel 20.

  The rear panel 20 is formed into a hook shape by sewing the side sides 21A and 21B of the first cutout portion 21 and the side sides 22a and 22b of the second cutout portion 22 with sutures. The diameter of the outer peripheral end of the bowl-shaped rear panel 20 is substantially the same as the diameter of the circular front panel 19. The driver's seat airbag 18 is constructed by sewing the peripheral edge of the bowl-shaped rear panel 20 and the peripheral edge of the front panel 19 with a suture thread 29.

  The airbag 18 for the driver's seat also has a rear panel 20 sewn in a hook shape, and therefore, as shown in FIG. 11, compared to the distance from the stitched portion between the rear panel 20 and the front panel 19 to the front panel front surface in the inflated state. Thus, the distance from the stitched portion to the rear end of the driver's seat airbag 18 is large. Therefore, the inflation thickness of the driver's seat airbag 18 is larger than the inflation thickness of the driver's seat airbag using a circular panel having the same diameter as the front panel as the rear panel.

  Further, since the driver seat airbag 18 is provided with the four notches 21 and 22 in the rear panel 20, the rear airbag 20 is inflated as compared with the driver seat airbag provided with only two notches. Excellent form stability.

  Furthermore, in this embodiment, the first cutout portion 21 is provided with the narrow width portion 21b and the second tether 23 is provided. A constricted portion P is provided at 18. That is, the diameter of the driver's seat airbag 18 in the constricted portion P is larger than the diameter of the first largest diameter portion F on the occupant side with respect to the constricted portion P and the diameter of the second largest diameter portion E on the steering wheel 30 side with respect to the constricted portion P. Is also small. The second maximum diameter portion E on the steering wheel 30 side is located closer to the passenger than the steering wheel 30, and the diameter thereof is larger than the diameter of the steering wheel 30. Therefore, the second maximum diameter portion E covers the steering wheel 30 from the passenger side. By engaging the second maximum diameter portion E with the steering wheel 30 in this manner, the posture of the driver's seat airbag 18 at the time of the oblique collision is stabilized.

  12 and 13 further includes a narrow portion 21b so that the constricted portion P is formed at a position overlapping the steering wheel 30 from the inner peripheral side and avoiding spokes (not shown). It is provided on the center side of the rear panel 20 ′. As shown in FIG. 13, the constricted portion P engages with the steering wheel 30 from the inner peripheral side. Further, the second maximum diameter portion E is located on the side opposite to the occupant from the steering wheel 30. The other configuration of the driver's seat airbag 18 'is the same as that of the driver's seat airbag 18, and the same reference numerals have the same parts.

  The driver's seat airbag 18 ′ also has the same effects as the driver's seat airbag 18. In this driver's seat airbag 18 ', the steering wheel 30 is sandwiched between the second largest diameter portion E of the driver's seat airbag 18' and the portion closer to the passenger than the constricted portion P. The stability of the airbag 18 'for the driver's seat at the time is high.

  In the driver-seat airbags 18 and 18 ′ of FIGS. 10 to 13, two second cutout portions 21 and two second cutout portions 22 are provided, but the number of each is limited to this. Instead, for example, only three or more first cutout portions 21 may be provided.

  The above embodiment is an example of the present invention, and the present invention may be other than the above.

1,1 ', 10,18,18'Driver's seat airbag 2,19 Front panel 3,20 Rear panel 4,21,22 Notch 5,25 Inflator opening 7,27 Vent hole 11 Tuck 13,13, 23 Tether 21b Narrow part

Claims (9)

In the driver's seat airbag formed by connecting the peripheral edges of the front panel and the rear panel,
The airbag for a driver's seat, wherein the rear panel is provided with a circumferential length reducing portion for reducing the circumferential length at three or more positions on the periphery.   The driver seat airbag according to claim 1, wherein the peripheral length reducing portion is a notch portion provided from the periphery of the rear panel toward the center side, and the sides of the notch portion are coupled to each other. .   The driver's seat airbag according to claim 1, wherein the circumferential length reducing portion includes a tack portion.   4. The driving according to claim 1, further comprising: a first tether that connects an occupant-facing surface of the driver airbag and a rear end of the driver airbag. 5. Seat airbag.   5. The driver's seat airbag according to claim 4, wherein the first tether increases its length when a predetermined tension or more is applied.   3. The driver seat according to claim 2, wherein the notched portion has a narrow width portion in which a distance between the side sides is smaller than a center side of the rear panel at a middle portion in a radial direction of the rear panel. A driver's seat airbag characterized in that a constriction is formed in the airbag.   The driver's seat airbag according to claim 6, wherein a second tether for reducing the diameter of the constricted portion is provided.   The area of the rear panel inside the stitching line between the front panel and the rear panel according to claim 1 is 1.1 to 1.3 times the area of the front panel inside the stitching line. A driver's seat airbag characterized by being   A driver's seat airbag device comprising: the driver's seat airbag according to any one of claims 1 to 8; and an inflator for inflating the driver's seat airbag.

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