JP5411798B2 - Airbag device - Google Patents

Description

The present invention relates to an airbag device that absorbs an impact by deploying a tubular airbag in which a metal plate is folded and the openings at both ends in the longitudinal direction are closed with a gas generated by an inflator.

  By storing a cloth airbag folded inside the pillar garnish that covers the front of the front pillar of an automobile, and supplying the gas generated by the inflator at the time of collision with a pedestrian to the airbag, from the gap where the pillar garnish broke A pedestrian protection airbag apparatus that protects a pedestrian by deploying an airbag along the front surface of the front pillar is known from Patent Document 1 below.

  In addition, the pillar garnish that covers the front of the front pillar of the automobile is supported on the pillar skeleton member via a link-type pillar drive mechanism, and the pillar garnish is lifted from the pillar skeleton member by the pillar drive mechanism at the time of a collision with a pedestrian, A pedestrian protection shock absorbing structure that absorbs collision energy by allowing a pillar garnish to stroke is known from Patent Document 2 below.

JP 2002-283939 A JP 2006-282105 A

  However, in the invention described in Patent Document 1, it is difficult to maintain the deployed state for a long time because the airbag is made of cloth, and depending on the timing at which the pedestrian collides with the front pillar, the impact is sufficient. There was a possibility that the absorption effect could not be exhibited.

  Further, the invention described in Patent Document 2 has a complicated structure of a link-type pillar drive mechanism that movably supports the pillar garnish on the pillar skeleton member, which increases the number of parts and causes a cost increase. was there.

  Therefore, the present applicant arranges a metal airbag folded in a zigzag manner between the front window glass and the front pillar, and deploys the airbag in a tube shape along the front pillar when colliding with a pedestrian, This has already been proposed in Japanese Patent Application No. 2009-224380.

  However, the one proposed in the above Japanese Patent Application No. 2009-224380 is such that both ends in the longitudinal direction of the folded airbag are fixed to the opening of the end cap by press fitting, so that both ends in the longitudinal direction of the airbag are long. It becomes difficult to deploy compared to the center of the direction. As a result, the folded state is not released sufficiently at both ends in the longitudinal direction even after the airbag is deployed, the rigidity is increased because the cross-sectional shape is not circular, and the impact absorption performance when a pedestrian collides is reduced. There was a possibility.

The present invention has been made in view of the above circumstances, by lowering the rigidity of the longitudinal ends of the metallic-made airbag, intended to ensure a uniform shock absorbing capacity over the entire length in the longitudinal direction And

In order to achieve the above object, according to the first aspect of the present invention, a tubular air bag in which a metal plate is folded to close the openings at both ends in the longitudinal direction is expanded with a gas generated by an inflator and subjected to an impact. An airbag device is proposed in which the thickness of both end portions in the longitudinal direction is thinner than the thickness of the central portion in the longitudinal direction.

  According to the invention described in claim 2, in addition to the configuration of claim 1, there is provided an airbag apparatus characterized in that a plate thickness of the central portion in the longitudinal direction of the airbag is 0.7 mm or more. Proposed.

  According to the invention described in claim 3, in addition to the structure of claim 1 or claim 2, the difference between the plate thickness at both longitudinal ends of the airbag and the plate thickness at the central portion in the longitudinal direction. An air bag device is proposed, characterized in that it is 0.2 mm to 0.3 mm.

  According to the invention described in claim 4, in addition to the structure of any one of claims 1 to 3, the blank material forming the airbag has both longitudinal end portions having different plate thicknesses. An airbag apparatus is proposed in which the center part in the longitudinal direction is joined by tailored blank welding.

  According to the invention described in claim 5, in addition to the structure of any one of claims 1 to 3, the blank material that constitutes the airbag has both longitudinal end portions with different plate thicknesses. An airbag apparatus is proposed in which the center portion and the longitudinal center portion are overlapped and joined by spot welding.

  According to the invention described in claim 6, in addition to the configuration of any one of claims 1 to 5, the airbag has a length at both ends in the longitudinal direction and a length at the center in the longitudinal direction. An airbag device is proposed in which the two are substantially equal.

According to the first aspect, without collapsible and longitudinal ends occluded tubular airbag opening of folded metal plate once deployed, to absorb the shock by the plastic deformation of the metal because, not only reduces the weight and cost by employing the small inflator capacity, it is possible to exhibit a stable impact absorption performance regardless shift of timing of collision. In addition, the plate thickness at both longitudinal ends of the airbag, which is difficult to deploy and may reduce shock absorption performance, is made thinner than the plate thickness at the longitudinal central portion where it is easy to deploy. By reducing the rigidity of both end portions in the longitudinal direction while maintaining the rigidity of the central portion in the direction, uniform shock absorbing performance can be ensured over the entire length of the airbag.

According to the second aspect of the present invention, since the plate thickness of the central portion in the longitudinal direction of the airbag is set to 0.7 mm or more, the rigidity of the central portion in the longitudinal direction can be ensured to prevent bottoming at the time of collision. .

  According to the third aspect of the present invention, since the difference between the plate thickness at both ends in the longitudinal direction of the airbag and the plate thickness at the central portion in the longitudinal direction is 0.2 mm to 0.3 mm, the entire length of the airbag is maintained. And uniform shock absorption performance.

  Moreover, according to the structure of Claim 4, since what used the thing which joined the longitudinal direction both ends from which plate | board thickness differs in a longitudinal direction center part by tailored blank welding to the blank material which comprises an airbag, the blank material is low. Can be obtained at a cost.

  Moreover, according to the structure of Claim 5, since the blank material which comprises an airbag uses what overlapped the longitudinal direction both ends and longitudinal direction center part from which board thickness differs, and was joined by spot welding, The blank material Can be obtained at low cost, and a gap between adjacent spot welds can be used as a vent hole.

  Further, according to the configuration of the sixth aspect, since the length of both end portions in the longitudinal direction of the airbag and the length of the central portion in the longitudinal direction are substantially equal, the structure of the blank material can be simplified and the cost can be reduced.

The top view of the vehicle body front part of a motor vehicle. FIG. 2 is an enlarged sectional view taken along line 2-2 in FIG. 1. The perspective view of an airbag. FIG. FIG. 5 is an enlarged perspective view of part 5 of FIG. Action explanatory drawing at the time of air bag deployment corresponding to FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 3. Explanatory drawing of the manufacturing method of a blank material. The graph which shows the relationship between the board thickness of the longitudinal direction both ends of a blank material, and a head impact value.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the automobile is provided with a front window glass 12 behind a hood 11, and between the left and right edges 12 a and 12 a of the front window glass 12 and the door glasses 14 and 14 of the front doors 13 and 13. Front pillars 15 and 15 are arranged so as to be sandwiched.

  As shown in FIG. 2, the front pillar 15 has a closed cross-section formed by connecting an outer panel 16 positioned on the outer side of the vehicle body and an inner panel 17 positioned on the inner side of the vehicle body. A metal airbag 18 also serving as a garnish is provided in a folded state. The edge portion 12a of the front window glass 12 is overlapped with the front surface of the coupling portions 16c and 17a of the outer panel 16 and the inner panel 17 via the dam rubber 20, and is bonded with an adhesive 21.

  The airbag 18 made of a folded metal tube includes a garnish portion 18a, a window glass side folding portion 18b, an outer panel side folding portion 18c, and an inflator support portion 18d. The garnish portion 18a is smoothly connected from the side surface 16b of the outer panel 16 of the front pillar 15 toward the front window glass 12, and functions as a pillar garnish disposed between the outer panel 16 and the front window glass 12. Yes.

  The window glass side folding portion 18b and the outer panel side folding portion 18c are folded in a zigzag manner on the back surface side (rear side) of the garnish portion 18a in order to secure an allowance when the airbag 18 is deployed. In that case, the folding width W2 of the outer panel side folding part 18c is set larger than the folding width W1 of the window glass side folding part 18b.

  As apparent from FIGS. 3 and 5, both ends of the folded airbag 18 are thinly press-molded, and end caps 24 and 24 are fitted and welded to the ends of the airbag 18. The part is sealed. In addition, if the space which arrange | positions the both ends of the airbag 18 can be ensured on the vehicle body side, it is not necessary to press-mold both ends thinly. Each end cap 24 includes a mounting portion 24 a, and a nut 27 is screwed into a bolt 26 passing through the bolt hole 24 b of the mounting portion 24 a and the vehicle body panel 25, so that the airbag 18 extends along the front pillar 15. Fixed.

  An inflator 19 that generates gas for deploying the airbag 18 is attached to a lower end portion of the inflator support portion 18d facing the garnish portion 18a with the window glass side folding portion 18b and the outer panel side folding portion 18c interposed therebetween.

  As is apparent from FIGS. 2 to 4, the cylindrical inflator 19 is fixed to the inner surface of a mounting bracket 28 having a U-shaped cross section by two fixing tools 29, 29. The mounting bracket 28 is an airbag. The opening 18e formed in the 18 inflator support portion 18d is covered from the outside and fixed with bolts 30 and nuts 31.

  As apparent from FIG. 2, an outer panel side lip 32 is provided at the boundary between the garnish portion 18 a of the airbag 18 and the outer panel side folded portion 18 c, and this outer panel side lip 32 is the front surface 16 a of the outer panel 16. Abut. Further, a window glass side lip 33 is provided at the boundary between the window glass side folding portion 18b and the inflator support portion 18d of the airbag 18, and this window glass side lip 33 contacts the front surface of the edge portion 12a of the front window glass 12. Touch. The outer panel side lip 32 and the window glass side lip 33 can prevent rainwater and the like from entering the inflator support portion 18d side of the airbag 18, thereby protecting the inflator 19.

  As shown in FIGS. 7 and 8A, the blank 34 of the airbag 18 is a tailored blank in which two longitudinal ends 34a and 34a and one longitudinal center 34b are tailored blank welded w1. Composed of materials. The tailored blank material is obtained by abutting and welding the end portions of blank materials having different plate thicknesses. In the present embodiment, the plate thicknesses of the longitudinal end portions 34a and 34a are 0.4 mm to 0.5 mm. The plate thickness of the central portion 34b in the longitudinal direction is 0.7 mm. That is, the difference between the plate thickness of the longitudinal ends 34a, 34a of the blank 34 and the plate thickness of the longitudinal center 34b is 0.2 mm to 0.3 mm.

  When the total length of the blank material 34 is L, the lengths of the longitudinal end portions 34a and 34a are L / 3, and the length of the longitudinal center portion 34b is L / 3. That is, the blank 34 is configured by tailored blank welding w1 of two longitudinal ends 34a, 34a and one longitudinal center 34b having equal length L / 3.

  The blank material 34 is formed into a tube shape by being folded by roll forming or pressing, and then superposed on both side edges along the longitudinal direction and MIG welding or spot welding.

  Note that, as shown in FIG. 8B, the blank material 34 may be formed by spot welding w2 by superimposing two longitudinal ends 34a, 34a and one longitudinal center 34b. good. At this time, if the step is formed in the thick-side longitudinal central portion 34b and the thin-side longitudinal ends 34a, 34a are overlapped with the step, the connecting portion can be made smooth. The air bag 18 completed in this way leaks gas from between the portions where the blank material 34 is discontinuously spot welded w2. However, by making this gap function as a vent hole for the air bag 18, a special vent hole is formed. The manufacturing cost can be reduced by eliminating the need for forming.

  And the airbag 18 is comprised by obstruct | occluding the both ends opening part of the metal tube manufactured from the said blank material 34 with the end caps 24 and 24. FIG.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  During normal times when the airbag 18 is not deployed, the garnish portion 18a of the airbag 18 is smoothly connected to the side surface 16b of the outer panel 16 of the front pillar 15 to exhibit the function of the pillar garnish. The number of parts can be reduced. Moreover, since the airbag 18 is compactly disposed between the front pillar 15 and the front window glass 12 by replacing the conventional pillar garnish, the front pillar is eliminated while eliminating the case and cover for storing the folded airbag 18. The appearance around 15 can be maintained well.

  Now, when it is detected that the vehicle has collided with a pedestrian, the inflator 19 is activated, and the internal pressure of the airbag 18 is increased by the gas generated by the inflator 19. As shown in FIG. 6, the window glass side folding portion 18 b and the outer panel side folding portion 18 c of the airbag 18 are first inflated toward the outside of the vehicle body and then the outer panel of the front pillar 15, as shown in FIG. 16 is developed in the left-right direction so as to cover the front surface 16a and the side surface 16b.

  At this time, since the airbag 18 includes the window glass side folding portion 18b and the outer panel side folding portion 18c, a large circumferential length of the airbag 18 after deployment is ensured, and a large area of the front pillar 15 is covered to absorb shock. Performance can be increased. Further, since the front pillar 15 is harder than the front window glass 12, the impact given to the pedestrian is increased, but the folding width W2 of the outer panel side folding part 18c is set larger than the folding width W1 of the window glass side folding part 18b. As a result, the expansion allowance (expansion amount) at the time of deployment of the outer panel side folding portion 18c is increased, and the airbag 18 is deployed so as to wrap around the side surface 16b side of the outer panel 16 to further improve the shock absorbing performance. it can.

  The airbag device for pedestrians has a characteristic that a relatively large difference is likely to occur in the time until the pedestrian collides with the front pillar 15 according to the physique of the pedestrian and the vehicle speed at the time of the collision. Therefore, the conventional fabric airbag has a problem that a large-capacity inflator that continuously generates gas is required to maintain the deployed state for a predetermined time. On the other hand, in the present embodiment, since the metal airbag 18 is adopted, the airbag 18 once deployed is maintained in the deployed state even after the supply of gas is stopped. Since the impact of the collision is absorbed, effective impact absorbing performance can be exhibited regardless of the timing at which the pedestrian collides with the front pillar 15 while reducing the capacity of the inflator 19.

  By the way, when the airbag 18 is deployed, the longitudinal end portions 34a, 34a are coupled to the closing members 24, 24 in a folded state, so that it is difficult to deploy compared to the longitudinal center portion 34b. As a result, the longitudinal center portion 34b of the airbag 18 expands in a substantially circular cross-section, whereas the longitudinal end portions 34a and 34a are unfolded completely so that they are unfolded. By functioning as a reinforcing rib, there is a possibility that the rigidity when an occupant collides becomes too high and effective shock absorbing performance cannot be exhibited.

  However, in this embodiment, since the plate thickness of the longitudinal end portions 34a, 34a of the airbag 18 is made smaller than the plate thickness of the longitudinal center portion 34b, the longitudinal end portions 34a, 34a that are difficult to deploy are easily deployed. The airbag 18 can be deployed in the same manner as the central portion 34b in the longitudinal direction, and the rigidity of the airbag 18 can be made uniform over the entire length to improve the impact absorption performance. In addition, the weight of the airbag 18 can be reduced. At this time, if the thickness of the entire blank material 34 of the airbag 18 is reduced to 0.7 mm or less, the rigidity of the longitudinal center portion 34b that is easy to deploy becomes insufficient, and the passenger collides with the airbag 18. There is a possibility that the bottom with the bottom (a state in which the airbag 18 is completely crushed and the inner surfaces are in contact with each other) is generated and the shock absorbing performance is deteriorated.

  Further, if the thickness of one blank 34 is changed between the longitudinal ends 34a and 34a and the longitudinal center 34b, there is a problem that the manufacturing cost increases, but the two longitudinal ends 34a, By adopting the blank material 34 in which 34a and one longitudinal center part 34b are joined, the manufacturing cost can be reduced. Furthermore, since the lengths of the two longitudinal ends 34a, 34a of the blank material 34 are equal to the length of the longitudinal center portion 34b of the blank material 34, the dimensional management of the blank material 34 is simplified and further cost is increased. Reduction can be achieved.

  FIG. 9 shows the relationship between the plate thickness (horizontal axis) and the head impact value (vertical axis) of the longitudinal end portions 34a and 34a in the airbag 18 having a length of 800 mm. At a position 250 mm from the longitudinal center of the airbag 18 (see the solid line) and at a position 300 mm from the longitudinal center of the airbag 18 (see the broken line), the head impact value falls below the threshold when the plate thickness becomes 0.6 mm or more. It can be seen that sufficient shock absorbing performance is not exhibited. Therefore, it is considered that the plate thickness of the longitudinal ends 34a and 34a at which the head impact value does not exceed the threshold value and the necessary strength is obtained is 0.4 mm to 0.5 mm. From the above, in the blank material 34 of the present embodiment, the plate thickness of the longitudinal end portions 34a and 34a is 0.7 mm, and the plate thickness of the longitudinal center portion 34b is 0.5 mm.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the method of folding the airbag 18 is not limited to the embodiment, and any folding method can be adopted.

18 Airbag 19 Inflator 34 Blank 34a Longitudinal ends 34b Longitudinal center w1 Tailored blank welding w2 Spot welding

Claims (6)

A tubular airbag (18) in which a metal plate is folded to close the opening at both longitudinal ends (34a) is expanded with a gas generated by an inflator (19) to absorb an impact ,
The airbag device (18) is characterized in that the plate thickness of both longitudinal end portions (34a) is thinner than the plate thickness of the longitudinal center portion (34b).   The airbag device according to claim 1, wherein a plate thickness of the longitudinal center portion (34b) of the airbag (18) is 0.7 mm or more.   The difference between the thickness of the longitudinal end portions (34a) of the airbag (18) and the thickness of the longitudinal center portion (34b) is 0.2 mm to 0.3 mm. The airbag apparatus of Claim 1 or Claim 2.   In the blank material (34) constituting the airbag (18), the longitudinal end portions (34a) and the longitudinal center portion (34b) having different plate thicknesses are joined by tailored blank welding (w1). The airbag device according to any one of claims 1 to 3, wherein the airbag device is characterized by the following.   The blank material (34) constituting the airbag (18) is joined by spot welding (w2) with the longitudinal end portions (34a) and the longitudinal center portion (34b) having different thicknesses overlapped. The airbag device according to any one of claims 1 to 3, wherein the airbag device is characterized in that:   The length of the longitudinal direction both ends (34a) and the length of a longitudinal direction center part (34b) of the said blank material (34) are substantially equal, The any one of Claims 1-5 characterized by the above-mentioned. The airbag apparatus as described in.

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