JP2000135959A - Lid structure of air bag device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten appearance and quality of an instrument panel through the suppression of creases formed in the skin layer of a laminated sheet and to prevent the formation of fragments of the instrument panel and the scatter of the fragments when an air bag is expanded by heightening the three adhesive strength of the laminated sheet, an air bag lid and instrument panel core material. SOLUTION: A protruding face 17 extended along a cleaved groove 15 formed at an air bag lid 11 is provided at a joint face of the air bag lid 11 to instrument panel core material 20. A thin layer injection-molded integrally with the instrument panel core material 20 at injection-molding the instrument panel core material 20 is formed between the protruding face 17 and the back face of a laminated sheet 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seamless type lid structure in which an airbag grid, which is a component of an airbag device for a vehicle, is integrally attached to the back side of a core material of an instrument panel. The present invention relates to a lid structure of an airbag device for a vehicle configured to increase a holding force of a connection between a grid and an instrument panel.

[0002]

2. Description of the Related Art A general configuration of an airbag device installed inside an instrument panel of an automobile includes an inflator, an airbag module including an airbag, and an airbag inflated by activation of the inflator. The airbag module is configured to receive the inflation force of the airbag and cleave it to inflate to the outside. The air bag grid is insert-molded integrally with the core material of the instrument panel, and by receiving the inflation force of the air bag,
The airbag that has been cleaved and inflated with the instrument panel 2 is inflated to the outside of the instrument panel.

As a conventional example of a mounting structure of the air bag grid to an instrument panel, for example, Japanese Patent Application Laid-Open Nos. 9-226413 and 9-301013.
There is a thing shown in the gazette. These conventional examples are shown in FIGS. 5 and 6, and in each of the conventional examples, an injection mold (not shown) for injection-molding the core material 1 of the instrument panel.
The air bag grid 2 and the skin sheet 3 which have been previously formed are inserted into the inside of the air bag grid, and the resin for forming the core 1 is injected into the injection mold after the injection mold is closed. , Skin sheet 3
The instrument panel core material 1 integral with the above is injection-molded.

[0004]

As described above, in any of the conventional examples, the airbag grid 2 is inserted at the time of injection molding of the instrument panel core material 1 so that the instrument panel core material 1 and the airbag grid 2 are integrated. For example, as shown in FIG.
6413), the surface of the airbag grid 2 is formed flat except for the hinge part 4, and the airbag grid 2 is provided between the surface of the airbag grid 2 and the skin sheet 3. Since the thin portion 5 of the instrument panel core 1 is formed, the airbag grid 2 is inflated and deployed by the airbag 7 of the airbag module 6.
In this case, the thin portion 5 of the instrument panel core material 1 is broken at the time of deployment, and the broken pieces are liable to be scattered. In addition, when the air bag grid 2 is deployed, the air bag grid is not smoothly deployed, and the air bag grid is liable to be broken due to brittleness of the resin material particularly in cold weather.

In the conventional example shown in FIG. 6 (Japanese Patent Application Laid-Open No. 9-301013), a bent portion formed at a portion of the airbag lid 2 to be broken is in contact with the skin. Therefore, at the time of injection molding of the instrument panel core material 1 into which the air backgrid 2 and the skin sheet 3 are inserted, due to the difference in the heat shrinkage of the air bag grid 2, the skin sheet 3, and the instrument panel core material 1, There were inconveniences such as the formation of corrugated wrinkles on the surface and the deterioration of quality.

The present invention has been made in view of such conventional problems, and includes an air bag grid formed by resin molding in advance, and a two-layer laminate sheet or a skin layer, a foam layer, and a backing layer comprising a skin layer and a foam layer. In the lid structure of an airbag apparatus, which is formed by injecting a resin for molding an instrument panel core material into an instrument panel molding die into which a three-layer laminate sheet composed of: To increase the adhesive strength of the three layers with the material,
And to suppress the generation of wrinkles, particularly in the skin layer of the laminate sheet, to enhance the appearance and quality of the instrument panel, and to prevent the generation of fragments of the instrument panel and the scattering of the fragments when the airbag is inflated. A first object is to provide an airbag grid structure that can be prevented.

According to the present invention, in the lid structure of the airbag device, the low-temperature embrittlement of the three layers is enhanced, and the airbag grid is broken when the airbag grid is split and expanded when the airbag is inflated. Not
It is a second object of the present invention to provide a structure of a lid hinge portion that can be accurately deployed with a previously formed hinge portion as a boundary.

[0008]

According to the first aspect of the present invention, there is provided a laminate sheet comprising a skin layer and a foam layer, or a laminate layer comprising a skin layer, a foam layer and a backing layer. By injecting a resin for forming an instrument panel core into a mold having a three-layer laminate sheet made of
In the lid structure in which the instrument panel core is integrally formed with the air bag grid, the convex surface along the cleavage groove formed in the air bag grid is formed on the joint surface of the air bag grid with the instrument panel core. Provided, between this ridge surface and the back of the laminate sheet,
The present invention is characterized in that it is a lid structure of a vehicle airbag device in which a thin layer is formed by injection molding integrally with an instrument panel core at the time of injection molding of an instrument panel core.

According to a second aspect of the present invention, in order to achieve the second object, the instrument panel is positioned on the back side of the instrument panel core material having a laminate sheet attached to the surface thereof, in parallel with the instrument panel back side. In a lid structure having an air bag grid formed by integrally forming a cleavage wall surface and a lid side wall formed on the periphery of the cleavage wall surface via a hinge portion, the hinge portion rises from the cleavage wall surface.
The cross-section has a substantially U-shape including a rising portion of the strip and a flat portion connecting between the rising edges of the rising portions. The thickness of the pair of rising portions is equal to the thickness of the flat portion, and the splitting is performed. The thickness of the wall is set to be thinner than the thickness of the wall, and the thickness of the cleavage wall is set to be thinner than the thickness of the lid side wall. It is characterized in that it is a lid structure of a vehicle airbag device which is parallel through a thin portion.

According to claim 3 of the present invention, claims 1 and 2
In addition, at least the skin layer and the backing layer of the laminate sheet have an olefinic thermoplastic elastomer (TPO)
The lid structure of the airbag device for a vehicle, which is formed by the above method.

According to a fourth aspect of the present invention, in addition to the first aspect, a lid structure of a vehicle airbag device having a thin layer having a thickness of about 0.5 mm is provided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in FIGS. 1 to 3. First, the configuration of a cleavage groove for an air bag grid will be described.

The airbag device for a vehicle according to this embodiment includes an airbag module 10 fixed to the vehicle body.
And an airbag lid 11 disposed opposite to the airbag inflating opening side. The airbag grid 11 is formed by using, for example, an olefin-based thermoplastic elastomer (TPO) as a molding material, and its shape is a cleavage position that is positioned so as to overlap along the back surface of an instrument panel core material described later. Wall 12
And a lid side wall 13 extending from each side edge of the cleaved wall surface 12 to the back side of the airbag lid 11, and an outer surface of each of the lid side walls 13 is protruded from the side wall surface to form an instrument panel. Ribs 14 are formed to increase the bonding strength with the core material.

Further, on the cleavage wall surface 12 forming the air bag grid 11, there is formed an application portion 16 of a cleavage groove 15 extending in a plane H shape or a U-shape, and the cleavage groove application portion 16 is provided on the cleavage wall surface. The protruding side protruding from the surface side of 12 (the side in contact with the instrument panel core material) forms a flat convex ridge surface 17. Numeral 18 protrudes from the front surface of the cleavage wall surface 12, and the protruding side is a flat surface. The hinge 18 is formed into a generally U-shaped cross-section. The details will be described later.

Reference numeral 19 denotes a laminated sheet formed by a powder slush molding method or a vacuum molding method. The laminated sheet 19 is made of an olefin-based thermoplastic elastomer (TPO) as a molding material and has a thickness of, for example, about 1 m.
m, a foam layer 19B having a thickness of about 3 mm using PPF as a molding material, and a backing layer 19C having a thickness of about 0.5 mm using TPO as a molding material. It is. In this embodiment, the above 3
Although the laminated sheet 19 having a layer structure is used, the present invention is not limited to this. For example, a laminated sheet having a two-layer structure excluding the backing layer 19C may be used.

Reference numeral 20 denotes an instrument panel core material that is injection-molded in a mold in which the air bag grid 11 and the laminate sheet 19 are inserted. When molding the instrument panel core material with a resin, first, a predetermined molding die is used. The airbag lid 11 is inserted into one of the molds (not shown), the laminate sheet 19 is inserted into the other mold, and both molds are closed.

Next, a polypropylene resin compatible with the above-mentioned TPO, for example, a molten resin of PPC is injected into the mold, so that the laminate sheet 19 and the airbag lid 1 are formed.
Instrument panel core material 20 integrally joined with 1
Is formed. After releasing the molded article thus molded, the air bag grid 1 is removed by laser cutting means or the like.
The intended lid structure can be obtained by forming the cleavage groove 15 along the central portion of the cleavage groove applying portion 16 of the ridge formed in FIG.

In the thus constructed lid structure, the convex ridge 17 provided on the air bag grid 11 when the mold is inserted into the injection mold and the mold is closed, and the back surface of the laminate sheet 19 are provided. Is about 0
Since the thickness is set to 5 mm, the injection thickness of the resin injected into the gap between the convex ridge surface 17 and the back surface of the laminate sheet 19 during the injection molding of the instrument panel core material 20 is about 0. A thin layer 21 of 0.5 mm is formed. The thin layer 21 of the resin serves as an adhesive for bonding the convex surface 17 of the airbag lid 11 and the back surface of the laminate sheet 19, thereby enhancing the adhesion between the airbag lid 11 and the laminate sheet 19. It is.

The T forming the backing layer 19C
The physical properties of the PO against temperature are as shown in Table 1. By setting such physical property values, it becomes possible to prevent brittle rupture of the backing layer 19C, which causes rupture of the airbag grid 11, and particularly to prevent low temperature resistance. The embrittlement was good, and the backing layer 19C was not brittlely broken, for example, in an airbag deployment test at −40 ° C.

[0020]

[Table 1]

Also, the convex ridge 1 of the air bag grid 11 is provided.
Since the thin layer 21 but the PPC resin is interposed between the metal sheet 7 and the back surface of the laminate sheet 19, the difference in the heat shrinkage of the instrument panel core 20 and the air back grid 11 with respect to the laminate sheet 19 is absorbed. The instrument panel core 20
Of the laminate sheet 19 at the time of injection molding can be prevented.

Next, a specific configuration of the hinge portion 18 forming the air bag grid 11 will be described with reference to the drawings.
As shown in FIG. 1, the airbag lid 11 has a cleavage wall surface 12 positioned parallel to the laminate sheet 19, and a lid side wall 13 extending from both side edges of the cleavage wall surface 12 toward the back side of the airbag lid 11. In the vicinity of each lid side wall 13 of the cleavage wall surface 12, hinge portions 18 projecting from the surface side of the cleavage wall surface 12 are formed.

The shape of the hinge 18 will be described in more detail. As shown in FIG.
A pair of rising portions 22 that are bent and raised toward the surface of the cleavage wall surface 12 and a flat portion 23 that connects between the rising edges of the rising portions 22 and that is parallel to the surface of the cleavage wall surface 12.
And has a U-shaped cross section. The surface of the flat portion 23 is laminated on the laminate sheet 19 through a thin portion 20A formed integrally with the instrument panel core 20.
And are located in parallel.

The thickness of the two rising portions 22 is a
1, a3, the thickness of the flat portion 23 is a2, the thickness of the lid side wall 13 is b, and the thickness of the cleavage wall surface 12 is c, the thicknesses are set as follows. .

A1 = a2 = a3 <c <b In other words, both the rising portions 22 and the flat portion 23 have the same thickness,
The wall thickness of the rising portion 22 and the flat portion 23 is the thickness of the cleavage wall surface 12.
It is set to be thinner than the wall thickness. Further, the thickness of the cleavage wall surface 12 is set smaller than the thickness of the lid side wall 13.

A curved radius R1 is formed between the front and back surfaces of the cleavage wall surface 12 and the inner and outer surfaces of the upright portion 22, and a corner formed by the inner surface of the upright portion 22 and the back surface of the flat portion 23. Is formed in a curved radius R2.

In the hinge portion 18 having such a cross-sectional shape, when the cleavage wall surface 12 receives the inflation force of the airbag,
As described above, the fracture occurs along the cleavage groove 15 formed on the cleavage wall surface 12, and the cleavage wall surface 12 is opened. The opening of the cleavage wall 12 is formed on the basis of the hinge 18, and the rising portion 22 and the flat portion 2 of the hinge 18 are formed.
3 is formed to be thinner than the thicknesses of the other cleavage wall surface 12 and the lid side wall 13, the hinge 18
The opening operation (hinge operation) of the cleavage wall surface 12 at the boundary is smoothly performed. In particular, when the outside air is at a low temperature, the hinge portion 18 made of resin is hard to bend. However, since the hinge portion 18 is formed to be thinner than the other portions, it is possible to eliminate the difficulty in bending.

Further, since the hinge 18 has a substantially U-shaped cross section, the overall length of the axis Y in the planar direction of the hinge 18 can be made longer, so that when the cleavage wall surface 12 is torn. In this case, the extension of the hinge portion 18 can be reduced, whereby the deployment operation of the cleavage wall surface 12 can be smoothed. Further, the hinge 18
By making the surface of the flat portion 23 a smooth surface, the inward breaking of the flat portion 23 particularly when the cleavage wall surface 12 is unfolded becomes smooth, and the unfolded wall surface 12 is further easily unfolded.

The thickness c of the cleavage wall surface 12 is made smaller than the thickness b of the lid side wall portion 13 to reduce the weight of the cleavage wall surface 12. The inertial force acting on the wall surface 12 can be reduced, and the inner surface of the upright portion 22 and the flat portion 2
3 is formed so as to be less likely to crack at the corners when the cleavage wall surface 12 is deployed, so that the cleavage wall surface 12 is formed when the cleavage wall surface 12 is deployed. The disadvantage that the hinge portion 18 is broken at the boundary can be prevented beforehand.

Further, the thickness of the instrument panel core 20 near the cleavage groove 15 provided in the air bag grid 11 is a thin layer 21 of about 0.5 mm.
Moreover, since the instrument panel core 20 is wrapped by the ridges of the airbag lid 11 and the laminate 19, the fragments of the instrument panel core 20 during the opening operation of the airbag lid 11 related to the inflation of the airbag. Will not be scattered.

[0031]

As described above, according to the lid structure of the present invention, the adhesive force between the laminate sheet 19 and the airbag lid 11 is increased via the injection-molded instrument panel core 20 and the instrument At the time of injection molding of the panel core material 20, wrinkles do not occur on the laminated sheet inserted in the mold, and it is possible to prevent the quality of the instrument panel including the lid structure from deteriorating. Further, at the time of deployment of the airbag lid accompanying the inflation of the airbag, the cleaved wall surface 12 can be smoothly deployed with the hinge portion 18 as a boundary, and the cleaved wall surface 12 is broken from the hinge portion 18; Alternatively, the generation of fragments of the instrument panel core material and its scattering can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a lid structure according to the present invention.

FIG. 2 is an explanatory plan view showing a form of a convex surface formed on an air bag grid.

FIG. 3 is an enlarged sectional view of a main part in FIG. 1;

FIG. 4 is an enlarged view showing a hinge portion of a lid structure according to the present invention.

FIG. 5 is a sectional explanatory view showing a conventional lid structure.

FIG. 6 is an explanatory sectional view showing another conventional lid structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Air backgrid 12 ... Cleaving wall surface 13 ... Lid side wall 14 ... Rib 15 ... Cleaving groove 16 ... Cleaving groove application part 17 ... Convex ridge 18 ... Hinge part 19 ... Laminated sheet 20 ... Instrument panel core material 21 ... Thin layer 22 … Rising part 23… Flat part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kazuhiro Saito 2-1910 Nisshin-cho, Omiya-shi, Saitama F-term in Kansei Co., Ltd. (Reference) 3D044 BA01 BA14 BB01 BC03 BC04 BD04 3D054 AA14 BB09 BB23 FF04 FF20

Claims (4)

[Claims] 1. An air bag grid (11) pre-formed with a resin, comprising a two-layer laminate sheet comprising a skin layer and a foam layer or a three-layer laminate sheet comprising a skin layer, a foam layer and a backing layer. The resin for forming the instrument panel core material is injected into a molding die having the above-mentioned inserts, and the instrument panel core material (20) is added to the laminate sheet and the air backgrid.
Are formed integrally with each other, and the joint surface of the air bag grid (11) with the instrument panel core (20) is formed along a cleavage groove (15) formed in the air bag grid (11). A striation surface (17) is provided, and is integrated with the instrument panel core material (20) between the convex striation surface (17) and the back surface of the laminate sheet (19) during the injection molding of the instrument panel core material (20). A lid structure for an airbag device for a vehicle, wherein a thin layer (21) is formed by injection-molding the airbag device. 2. A cleavage wall surface (12) positioned parallel to the back surface of the instrument panel on the back side of the instrument panel core (20) having a laminate sheet (19) attached to the front surface thereof; In a lid structure having an airbag lid (11) in which a lid side wall (13) formed via a hinge portion (18) is integrally formed on an edge of the lid portion (12), the hinge portion (18) has a cleavage wall surface. (12) Two rising portions (22) rising from the upper surface and a planar portion (2) connecting between the rising edges of the rising portions (22).
3), the thickness of the pair of rising portions (22) and the thickness of the flat portion (23) are set to be equal and smaller than the thickness of the cleavage wall surface (12). The thickness of the cleavage wall surface (12) is the same as that of the lid side wall (13).
And the surface of the flat portion (23) was flattened to be parallel to the back surface of the laminate sheet (19) via the thin portion (20A) of the instrument panel (20). A lid structure for an airbag device for a vehicle, comprising: 3. The vehicle core according to claim 1, wherein at least the skin layer (19A) and the backing layer (19C) of the laminate sheet (19) are formed of an olefin-based thermoplastic elastomer. Lid structure of bag device. 4. The lid structure according to claim 1, wherein the thickness of the thin layer (21) is about 0.5 mm.