JPH08258658A - Structure of cabin side member having air bag door and manufacture of cabin side member - Google Patents

Abstract

PURPOSE: To eliminate risk that the part to be ruptured bears degradated appearance such as cracking originating from deterioration or contraction of the skin and generate a certain rupture when air bag is inflated. CONSTITUTION: A cabin side member 10 is equipped in a single piece with a skin 12 where a rupturable part 14 bounding an air back door part D is formed on the oversurface of a synthetic resin foaming layer 11, wherein a thin part 13 is provided on the rear surface of the skin with a constant width along the rupturable part, and a sponge-form material 30 embedded in the synthetic resin foaming layer is provided in the thin part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile air bag device, and more particularly to a structure of a vehicle interior side member having an air bag door portion and a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, as shown in FIG. 12 of the accompanying drawings, an airbag device provided on the passenger side of an automobile has a folded airbag A actuated in an accommodating member (container) C called a canister. It is housed together with I and is housed in an instrument panel which is a passenger compartment side member P on the front side of the passenger seat. The upper portion of the airbag accommodating member C is configured as an opening O for deploying the airbag A into the vehicle compartment, and the deployment opening O is normally covered by the airbag door portion D, so that the vehicle once In the event of a big impact, the actuating device I is actuated, and the inflated airbag A pushes the airbag door portion D from the inside and deploys it into the passenger compartment.

As the structure of the airbag door portion covering the deployment opening O of the airbag, there are a type in which an airbag door member is separately molded and is attached to a corresponding empty space in a passenger compartment member, and a passenger compartment. There is a type in which the airbag door is formed integrally with the side member, but the present invention relates to the latter structure.

That is, FIGS. 12 to 13 show a conventional example in which the airbag door portion D is integrally formed with the passenger compartment member P, but the passenger compartment member (instrument panel) P is made of synthetic resin. A skin 72 is integrally formed on the upper surface of the foam layer 71, and a thin rupturable portion 73 that defines an airbag back D is formed at a predetermined position of the skin 72 corresponding to the airbag deployment opening O. The thin portion 73 of the skin 72 to be broken is formed by forming a cut or a V groove with a high-frequency welder, a hot blade, a cold press cutter or the like after molding the skin 72. Reference numeral 74 in the figure
Is a core material provided on the back surface of the passenger compartment member P, 75 is an airbag door core material provided on the back surface of the airbag door portion D, and 76 is the airbag housing member C and the core material 74 (and the airbag). An attachment member for fixing the door core material 75), T is a breakable portion of the passenger compartment member P.

In this structure, as described above, when the airbag A is actuated and inflated, the airbag deployment opening O is opened.
The airbag door portion D of the upper passenger compartment member P is pushed from the rear surface side to push up the airbag door core material 75,
Due to the pushing-up force, stress concentrates on the thin-walled breakage portion 73 of the skin 72 and breaks, and the passenger compartment side member P tears off from the tearing (planned) portion T, and as shown in FIG. Opens. Reference numerals 73a and 73b in FIG. 14 represent fracture (planned) portions of the divided outer skin 72, and Ta and Tb represent the fractured (planned) portions of the similarly divided compartment P on the vehicle interior side. With the opening of the airbag door portion D, the airbag A is deployed in the passenger compartment.

However, the thin-walled breakable portion 73 that defines the air bag door portion D of the outer skin 72 of the passenger compartment member P is approximately 0.3 mm so that the breakable portion 73 can be reliably broken when the air bag is inflated. It is formed to have the following thickness. However, it is generally known that the vehicle interior side member P such as an instrument panel of an automobile is exposed to the sun rays radiated into the vehicle interior and the high heat inside the vehicle interior, and the skin 72 thereof deteriorates and contracts with the passage of time. Has been. When a thin scheduled breakage portion 73 having a thickness of 0.3 mm or less is formed on the skin 72 of the passenger compartment member P, the thin skin is expected to be ruptured due to deterioration of the skin 72 and shrinkage. It becomes the largest in part 73, and as a result,
It has been pointed out that problems such as cracks in the breakable portion 73 and the appearance of the synthetic resin foam layer 71 on the inside are likely to occur.

In response to this problem, if the thickness of the skin 72 at the breakable portion 73 is increased until the cracks due to deterioration are less likely to occur, the breakable portion 73 will not smoothly break when the airbag A inflates. There is a fear.

The deterioration of the skin 72 is caused by the deterioration of the skin 72.
The plasticizer contained in the vinyl chloride resin that constitutes the
2 is promoted by migrating into the synthetic resin foam layer 71 in contact with 2, or by migrating an amine contained in the synthetic resin foam layer 71 as a cross-linking agent or a catalyst into the skin 72, which is also thin and weak in strength. Expected break 7
It is believed that this also causes a crack in No. 3.

[0009]

SUMMARY OF THE INVENTION According to the present invention, when a thin portion to be fractured is formed on the skin of the vehicle interior side member as described above, the portion to be broken has an appearance such as a crack due to deterioration or shrinkage of the skin. An object of the present invention is to provide a structure of a vehicle-cabin-side member having a novel air bag door portion and a manufacturing method thereof, which can be reliably broken when the airbag is inflated without causing a defect.

[0010]

That is, the present invention provides:
In a passenger compartment member integrally having a skin in which a breakable portion that defines an airbag door portion is formed on an upper surface of a synthetic resin foam layer, a thin portion having a constant width on the back surface side of the skin along the breakable portion And a sponge-like material embedded in the synthetic resin foam layer is disposed in the thin portion, and a passenger compartment member having an airbag door portion is proposed. .

Further, as a method for realizing the above structure, a sponge having a constant width along the planned skin rupture portion while the skin resin material is still in a molten state at the time of powder slush molding of the skin with the skin resin material. A step of press-fitting a spongy material to obtain a skin in which a part of the spongy material is embedded and the embedded part is formed as a thin portion, and then the spongy material is integrally arranged in the thin portion. A synthetic resin foam material is injected into the back surface side of the skin to form a synthetic resin foam layer, and the sponge-like material is embedded in the synthetic resin foam layer and has a breakable portion on the upper surface that defines an airbag door portion. And a step of obtaining a vehicle interior side member having the above-mentioned. A method for manufacturing a vehicle interior side member having an airbag door section is proposed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. 1 is a schematic perspective view of an instrument panel of an automobile showing one embodiment of the structure of the present invention, FIG. 2 is a sectional view of a portion to which the airbag device is attached, and FIG. 3 is FIG.
4 is an enlarged sectional view of a portion indicated by an arrow 3 in FIG. 4, FIG. 4 is a perspective view showing an example of a spongy object, and FIG.

FIGS. 6 to 11 relate to a method of manufacturing a vehicle interior side member having an airbag door portion according to the present invention, and FIG. 6 is a sectional view showing a powder slush molding die used for molding a skin. 7 is a cross-sectional view showing the skin slush molding state of the powder slush molding die shown in FIG. 6, FIG. 8 is a cross-sectional view showing a state in which a spongy material is pressed into the skin resin material in the powder slush molding die, and FIG. 9 is a diagram. 8 is an enlarged cross-sectional view of a portion indicated by an arrow 9 in FIG. 8, and FIG.
FIG. 11 is a sectional view showing the foam-molded state.

As shown in FIGS. 1 to 3, the present invention relates to a vehicle-cabin-side member 10 such as an instrument panel, and in particular, a fracture plan for defining an airbag door portion D on the upper surface of a synthetic resin foam layer 11. The present invention relates to one integrally having the skin 12 on which the portion 14 is formed. The illustrated airbag device has a structure similar to that described in the section of the prior art, reference numeral A is an airbag, I is an operating device of the airbag A, C is an airbag accommodating member, O Is a deployment opening portion of the airbag, T is a (planned) portion of the vehicle compartment side member, 20 is a core material of the vehicle interior side member, 21 is a core material for an airbag door disposed above the airbag deployment opening portion, Reference numerals 22 and 23 denote attachment members for fixing the airbag accommodating member C to the passenger compartment member 10.

In the structure of the present invention, as is best understood from the enlarged sectional view of FIG. 3, a thin wall portion 13 having a constant width is formed along the planned breaking portion 14 on the back surface side of the skin 12 of the passenger compartment member 10. It is characterized in that the spongy material 30 embedded in the synthetic resin foam layer 11 is disposed in the thin portion 13 while being formed.

That is, the passenger compartment member 10 is formed in a predetermined instrument panel shape, and the upper surface of the synthetic resin foam layer 11 made of polyurethane foam or the like is the skin 1.
Covered by two. The skin 12 is formed by, for example, known powder slush molding, and the material thereof is generally soft PVC, PVC-urethane copolymer or thermoplastic polyolefin elastomer.

On the back surface 12a side of the skin 12, a thin portion 13 having a constant width and being weaker than the general portion is formed along the planned break portion 14. As shown in FIG. 3, the thin wall portion 13 has a portion 14 to be broken when the airbag door portion D is pressed from the inside by the expansion of the airbag A.
It is for easily and surely breaking. As for the thickness of the thin portion 13, the thickness of the general portion of the skin 12 is 1 to
In the case of about 2 mm, it is preferable to set it to 0.1 mm to 0.3 mm.

The spongy material 30 embedded in the synthetic resin foam layer 11 is disposed in the thin portion 13.
This spongy material 30 is for partially reinforcing the synthetic resin foam layer 11 and for avoiding the inconvenience caused by the deterioration of the thin skin portion 13 with time, as will be understood from FIG. It has a three-dimensional net-like skeleton structure in which a large number of holes 32, 32, ... Are formed on the surface and inside by the irregular and discontinuous net-like body 31.

The sponge-like material 30 is formed in a band shape in conformity with the shape of the thin portion 13, that is, a to-be-ruptured portion 14 having a substantially U-shape as shown in FIG.
In the case of having 3), it becomes a substantially U-shape similar to this.

A known foam material having a melting point higher than that of the skin 12 and having a large number of holes communicating with each other is preferable as a material forming the spongy material 30. For example, slab urethane, polyether-based or polyester-based foam and the like. In addition, metal wool and the like also have a favorable three-dimensional network skeleton structure, which is one of the preferable materials. The diameter of the hole 32 of the spongy material 30 is preferably about 0.5 to 3 mm.

Since the spongy material 30 is arranged in the thin-walled portion 13 in a state of being partially embedded in the synthetic resin foam layer 11 as described above, the foam layer in the hole 32 of the mesh body 31. The synthetic resin forming 11 has entered. Therefore, the skin 12 of the portion where the spongy material 30 is arranged
While the strength of is reduced by the thin portion 13, the synthetic resin foam layer 11 in the portion where the spongy material 30 is embedded is reinforced by the mesh body 31 of the spongy material 30. Therefore, the synthetic resin foam layer 11 in the portion in which the spongy material 30 is embedded in the thin portion 13 has a relatively higher strength than other general portions, and the airbag A expands to cause the airbag door portion. When D is pressed from the back surface, strong stress concentration occurs at the boundary between the two, and it is reliably broken. In addition, scattering of fragments and the like at the ruptured portion when the airbag is deployed is reduced.

Since the spongy material 30 arranged in the thin portion 13 of the outer skin 12 has an irregular and discontinuous shape having a constant width, not a continuous linear shape, The stress caused by the deterioration and shrinkage of the skin with time due to the sunlight radiated on the surface of the vehicle and the high heat in the passenger compartment was not concentrated in one place on the skin but was discontinuously distributed with a constant width on the planned fracture portion 14. It becomes a shape, and it is possible to prevent cracks and the like generated in the epidermis.

In the present embodiment, the thin portion 13 and the spongy material 30 are arranged outside along the breakable portion 14, but they may be arranged inside the breakable portion 14.

Further, depending on the form of the thin portion 13, the spongy material 30 can be formed intermittently along the breakable portion 14. In such a configuration, the thin wall portion has an intermittent perforated shape, and the heat resistance performance can be further improved without disturbing the breaking performance of the epidermis.

Further, when the spongy material 30 is made of the same material as the skin, for example, a soft PVC skin and PV
When the sponge-like material made of C foam is used, the breaking load of the skin is reduced and the door is easily broken without lowering the heat resistance of the skin.

Next, with reference to FIGS. 6 to 11, a method of manufacturing the vehicle interior side member having the structure of the present invention will be described. The method of manufacturing the vehicle interior side member having the airbag door portion proposed here is a step of obtaining a skin in which a spongy material is arranged in a thin portion,
A step of integrally forming a synthetic resin foam layer on the back surface side of the skin.

First, the skin forming process will be described.
As shown in FIGS. 6 and 7, the skin is formed by a known powder slush molding die 40. As shown in FIG. 6, the bucket 4 of the powder slush mold 40
In one powder container 42, a resin material 50 for the skin made of a thermoplastic synthetic resin powder such as soft PVC powder is contained.

The heating medium such as heating oil is supplied to the heating medium circulation pipes 55, 55, ... While heating the molding die 43 formed in a predetermined surface shape of the skin, the bucket 41 and the molding die 43 Is clamped and rotated a predetermined number of times as indicated by arrow a. Due to the rotation, as shown in FIG. 7, the resin material 50 for skin in the bucket 41 moves into the molding die 43 and comes into contact with the die surface 44. The resin material for skin 50
Is melted by the heat of the mold surface 44 and adheres to the mold surface 44 in a layered manner with a predetermined thickness to form a skin 51.

At the time of forming the skin, as shown in FIG. 8, the skin resin material contacting the mold surface 44 is still in a molten state (for example, the material temperature is about 190 ° C. to 210 ° C.).
(.Degree. C.) layered body 51a, a predetermined breaking portion 56
The spongy material 30 is press-fitted along. This sponge 30
The configuration of is as described above.

By pressing such a spongy material 30 into the layered body 51a of the epidermis which is still in a molten state, the spongy material 30 is embedded in the back surface of the layered body 51a as shown in FIG. The skin 51 in which the inserted portion is formed as the thin portion 52 is obtained. The thickness of the thin portion 52 is appropriately determined according to the embedding depth of the spongy material 30. Further, as described above, the spongy material 30 has a higher melting point than the resin material 50 for the skin, and therefore the skin layered body 51.
At the time of press-fitting into the inside a, it does not weld to the layered body 51a, and the skin 5 is maintained while the shape of the mesh body 31 is maintained.
It is embedded in 1.

Then, a synthetic resin foam layer is integrally formed on the back surface side of the outer skin 51 in which the spongy material 30 obtained as described above is embedded. That is, as shown in FIGS. 10 and 11, the mold surface 63 of the lower mold 61 of the foam molding mold 60.
Then, the skin 51 is arranged so that the side in which the spongy material 30 is embedded is the inner side. On the other hand, on the mold surface 64 of the upper mold 62 of the foam molding mold 60, the vehicle interior side member core material 53 and the airbag door core material 54 are appropriately held and arranged.

Then, the epidermis 5 arranged on the lower mold 61.
A predetermined amount of synthetic resin foam raw material 66 such as polyurethane raw material is injected from the pouring machine 65 to the back surface of No. 1 and then the upper mold 62 is closed to perform foam molding. Synthetic resin foam raw material 66
Foams and cures to form the synthetic resin foam layer 67. The spongy material 30 embedded in the outer skin 51 is embedded in the synthetic resin foam layer 67 by infiltrating and impregnating the synthetic resin foam raw material 66 into the holes 32. Then, the vehicle interior side member 68 having the skin 51 having the planned breakage portion 56 that defines the airbag door portion D on the upper surface side (the lower surface side in the mold) is obtained.

As described above, according to the manufacturing method of the present invention, the vehicle interior side member integrally having the synthetic resin foam layer on the back surface side of the skin in which the spongy material is integrally arranged in the thin portion is easily, easily and surely provided. Can be obtained.

[0034]

As shown and described above, according to the structure of the passenger compartment member having the airbag door portion of the present invention,
A thin portion is formed on the back surface of the skin with a certain width along the planned breakage portion, and the spongy material embedded in the synthetic resin foam layer is arranged in the thin portion, so the thin portion is linear. Instead, they will be dispersed discontinuously with a certain width. Therefore, even if the skin deteriorates over time and shrinks, stress concentration in one place of the thin part is prevented, and even if the skin deteriorates, cracks are prevented from occurring in the thin part. can do.

Further, since the sponge-like material reinforces the foam layer at the portion to be broken, the difference in strength between the thin-walled portion and the thin-walled portion where the spongy-like material is arranged and other general portions becomes significantly large. Therefore, when the airbag presses the airbag door portion from the inside, stress is effectively concentrated at the boundary portion between the two, that is, the portion to be broken, and the thin portion can be reliably broken.

Further, according to the manufacturing method of the invention disclosed herein, the vehicle interior side member having the above structure can be obtained easily, easily and surely.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an automobile instrument panel showing an embodiment of the structure of the present invention.

FIG. 2 is a cross-sectional view of a portion to which the airbag device is attached.

FIG. 3 is an enlarged sectional view of a portion indicated by an arrow 3 in FIG.

FIG. 4 is a perspective view showing an example of a spongy material.

FIG. 5 is a cross-sectional view showing a state in which the airbag door portion of the invention structure is opened.

FIG. 6 is a sectional view showing a powder slush molding die used for molding a skin, which relates to a method of manufacturing a vehicle interior side member having an airbag door portion according to the present invention.

FIG. 7 is a cross-sectional view showing a skin forming state of the powder slush molding die shown in FIG.

FIG. 8 is a cross-sectional view showing a state in which a spongy material is pressed into a skin resin material in a powder slush molding die.

9 is an enlarged sectional view of a portion indicated by an arrow 9 in FIG.

FIG. 10 is a cross-sectional view showing a state in which a synthetic resin foam material is injected into the back surface side of the epidermis on which the spongy material is placed.

FIG. 11 is a cross-sectional view showing the foam-molded state.

FIG. 12 is a cross-sectional view of a vehicle interior side member having a general airbag door portion.

FIG. 13 is an enlarged cross-sectional view of the relevant part.

FIG. 14 is a cross-sectional view showing a state in which the airbag door portion of the vehicle interior side member shown in FIG. 12 is deployed.

[Explanation of symbols]

 10 Vehicle Side Member 11 Synthetic Resin Foam Layer 12 Skin 13 Thinned Part 14 Expected Breakage Site 30 Sponge D Airbag Door

Claims (3)

[Claims] 1. A passenger compartment member integrally having a skin on which an air bag door portion is defined to be broken, which is formed on an upper surface of a synthetic resin foam layer, wherein the back surface side of the skin is along the break portion. A thin portion having a constant width is formed, and a sponge-like material embedded in the synthetic resin foam layer is arranged in the thin portion. Construction. 2. The structure of the vehicle interior side member according to claim 1, wherein the sponge-like material is an airbag door portion made of a foam material having a three-dimensional net-like skeleton structure. 3. The sponge material is formed by press-fitting a spongy material with a constant width along a skin breakage portion while the skin resin material is still in a molten state during powder slush molding of the skin with the skin resin material. A step of obtaining a skin in which a part of the filling material is embedded and the embedded portion is formed as a thin portion, and then a synthetic resin foam material on the back surface side of the skin in which the spongy material is integrally arranged in the thin portion. Is injected to form a synthetic resin foam layer, and the sponge-like material is embedded in the synthetic resin foam layer, and a vehicle interior side member having a skin with a planned breaking portion defining an airbag door portion on the upper surface is obtained. A method of manufacturing a vehicle interior side member having an airbag door portion, the method including: