JP2000247201A - Instrument panel for air bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy the door performance at a low temperature with the low cost in an instrument panel for an air bag comprising a door for the air bag device, integrated with a resin base material. SOLUTION: A film 26 made of a resin having a brittle point lower than that of a resin forming a base material 14 and superior in the low temperature characteristic, is attached to a door part 18a to be pressed and opened by the expansion of an air bag 36, of the resin base material 14 forming the approximately whole of an instrument panel 10, so that the base material 14 can be prevented from scattering in the low temperature rupture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an airbag for an automobile, in particular, an airbag for a passenger seat is housed inside in a folded state. The present invention relates to an instrument panel for an airbag, which is split so as to be deployed forward.

[0002]

2. Description of the Related Art In recent automobile instrument panels, an airbag device for inflating and deploying an airbag in a vehicle compartment at the time of a vehicle collision to restrain an occupant is often provided inside the instrument panel. This type of instrument panel requires a configuration for inflating the airbag into the vehicle compartment.

For example, a conventional instrument panel 100 for an airbag shown in FIG. 10 has a urethane foam between a skin material 101 made of a relatively soft material and a base material 102 made of a relatively hard material. An airbag including a folded airbag 111, an inflator 112 for supplying gas to the airbag 111, and a case 113 for accommodating the airbag 111, An apparatus 110 is provided. In the instrument panel 100, the airbag 11
The part that is pushed open with the expansion of
An opening 104 is provided, and a pair of double door-shaped door members 105 are arranged so as to close the opening 104. Further, the butt end 10 of the door material 105 is attached to the skin material 101.
6 is provided with a fragile portion 107 that is broken.

In this case, at the time of vehicle collision, the airbag 111
When the door material 105 is pushed open by the expansion of the opening, and the butted end portion 106 breaks the fragile portion 107 of the skin material 101, the instrument panel 100 is torn as shown by a two-dot chain line in FIG. Thereby, the airbag 111 inflates into the vehicle interior.

[0005]

However, in the above-mentioned conventional structure, in order to inflate the airbag 111,
Since the door member 105 which is a separate part from the base member 102 is required, there are problems that the number of parts is large and the number of assembling steps is large.

In this case, the door material 105 is simply attached to the base material 10.
Although it is possible to reduce the number of parts and the number of assembling steps simply by integrally molding the same material as 2, the base material is usually made of polypropylene (PP). The base material scatters due to its brittleness, and the door performance cannot be secured. To avoid this,
It is necessary to mold the entire base material including the door material with a resin having a low embrittlement point such as an ABS / PC resin, but these resins are expensive and increase the cost.

[0007] On the other hand, as shown in FIG.
While the base material 102 is formed of inexpensive PP by a two-stage injection molding in which the door portion 120 is formed integrally with another resin, the door portion 120 is formed.
Is formed of an olefin-based thermoplastic elastomer (TPO) having excellent low-temperature properties. However, in such a configuration, there is a problem that the injection mold becomes complicated and the equipment cost increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and is intended to provide an airbag instrument panel in which a door for an airbag device is integrated with a base material, at low cost and at low temperatures. It is an object of the present invention to provide a device that can satisfy the door deployment performance in the vehicle.

[0009]

An instrument panel for an airbag according to the present invention is provided with an airbag device inside thereof, which is broken by the inflation of the airbag when the vehicle collides and the airbag is placed in the vehicle interior. In the airbag instrument panel to be inflated, a door portion pushed and opened by the inflation of the airbag is formed integrally with a resin base material that constitutes substantially the entire area of the instrument panel, and Is a film in which a film made of a resin having a lower embrittlement point than the resin constituting the base material is adhered to at least the door portion.

According to such a configuration, even when a resin having insufficient low-temperature characteristics is used for the substrate, the film adhered to the door portion of the substrate has excellent low-temperature characteristics, so that the substrate is scattered at the time of low-temperature cleavage. Can be prevented. Therefore, while using a cheap resin for the base material including the door portion to reduce the cost, the film formed on the door portion can satisfy the door deployment performance at a low temperature.

In the above-mentioned instrument panel,
As described in claim 2, the base material may be an injection-molded product of a resin, and the film may be integrally attached to the base material by injection-molding the base material. in this case,
Since the film is integrally attached to the substrate when the substrate is injection-molded, the number of manufacturing steps is reduced.

In the above-mentioned instrument panel, the film may be attached to a preformed base material via an adhesive.

Further, the instrument panel includes:
As described in claim 4, a foam may be formed between the base material and the skin material forming the instrument panel surface in some cases. Further, the instrument panel may have a one-layer structure composed of only a base material, or may be a product obtained by injection-molding a resin base material on the back surface of a skin material having a single-layer structure or a multi-layer structure.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of an airbag instrument panel 10 according to one embodiment of the present invention. The instrument panel 10 includes a passenger seat airbag device 30 inside as a cover body, and covers an upper surface opening 32a of a case 32 thereof.

The instrument panel 10 includes a skin material 12 made of a relatively soft material such as polyvinyl chloride (PVC) or a thermoplastic elastomer (TPE) such as an olefin-based, styrene-based, or urethane-based material, and a polypropylene (PP). ) And a base material 14 made of a relatively hard resin such as acrylonitrile / styrene / glass (ASG), a foam 16 such as urethane foam is foam-formed to form a skin material 12, a base material 14, and a foam. 16 are integrated.

The airbag device 30 has an inflator 34 and a folded airbag 36 housed in a case 32 that opens upward, and when the vehicle collides, the inflator 34 is activated to supply the airbag. Depending on the gas
The airbag 36 is configured to be inflated and deployed from the opening 32a of the case 32.

A portion of the instrument panel 10 that covers the opening 32a of the case 32 is a door portion 18 that is pushed open when the airbag 36 is inflated. That is, the skin material 12 is formed with a thin-walled fragile portion 20 extending in the vehicle width direction substantially at the center of the portion covering the case opening 32a in the vehicle front-rear direction.
The base member 14 is also formed with a thin fragile portion 22 corresponding thereto, and the fragile portions 20 and 22 are broken by the upward pressing force accompanying the inflation of the airbag 36, and the cover is covered. The part opens back and forth.

The case opening 3 of the door portion 18
The door portion 18a on the side of the base member 14 that directly faces the base member 2a is integrally formed of the same synthetic resin material as the main body of the base member 14 by injection molding.

Reference numeral 24 denotes a mounting wall for connecting the instrument panel 10 and the case 32.
4, projecting from the rear surface of the door portion 18 a toward the case 32 and attached to the side surface of the case 32.

The door portion 18a of the base material 14
A film 26 made of a synthetic resin having better low-temperature characteristics than that of the synthetic resin is formed. This film 2
Reference numeral 6 denotes a low elongation film having a lower embrittlement point than the synthetic resin constituting the base material, and is made of, for example, a PC / ABS resin. The thickness of the film 26 is 0.2 to
It is about 0.8 mm.

In this embodiment, as shown in FIG. 2, the film 26 is provided only on the door portion 18a which is slightly wider than the case opening 32a. Further, the film 26 is disposed on the front side of the base material 14, that is, on the upper surface, as shown in FIG.

The film 26 is formed on the surface of the substrate 14 by so-called in-mold molding, which is integrally attached to the substrate 14 by injection molding the substrate 14. Specifically, as shown in FIG. 3, the film 26 is set on an upper mold 42, which is one of the injection molds 40, and adheres to the mold surface by vacuum suction. A certain lower mold 44 is closed, and a resin for forming the base material 14 is injected. Thereafter, the film 26 is cooled and removed from the mold, so that the film 26 is attached to the door portion 18a.
4 is obtained.

Then, as shown in FIG. 4, the obtained base material 14 is set on the upper mold 52 which is one of the foam molding dies 50, and the separately molded skin material 12 is placed on the foam molding mold 5.
The instrument panel 10 is obtained by setting and closing the lower mold 54, which is the other mold of the mold 0, and foaming the foaming raw material 17 between the base material 14 and the skin material 12.

In the instrument panel 10, at the time of a vehicle collision, the inflator 34 operates to supply gas to the airbag 36.
6 begins to expand. By the inflating airbag 36, the door portion 18a of the base material 14 of the instrument panel 10 is pressed upward to break the fragile portion 22, and furthermore, the fragile portion 20 of the skin material 12 is broken. As shown by a two-dot chain line, the door portion 18 is pushed back and forth to form an opening in the instrument panel 10. From this opening, the airbag 36 is inflated and deployed in the vehicle compartment to receive the occupant.

In the airbag instrument panel 10 of the present embodiment, the door portion 18a that is pushed open by the inflation of the airbag 36 is integrally formed of the same material as the main body of the base material 14, so that a separate component is provided. The number of parts and the number of assembling steps can be reduced as compared with the case where the door material is used. Further, since the film 26 having excellent low-temperature characteristics is adhered to the door portion 18a of the base material 14, the airbag device 30 at low temperature can be formed even though the base material 14 is made of a resin such as PP which does not have sufficient low-temperature characteristics. It is possible to prevent the base material 14 from being cracked or scattered during operation. Therefore, the door performance at low temperatures can be satisfied even though the base material 14 including the door portion 18a has a low-cost configuration made of inexpensive resin.

In the above embodiment, the film 26 is adhered to the surface side of the substrate 14, but the film 2
6 may be adhered to the back side of the substrate 14.

In the above embodiment, the film 26 is integrally attached to the base material 14 by in-mold molding. However, as shown in FIG. The film 26 can also be applied. In this case, an adhesive layer is formed on the back surface of the film 26, and this is attached to the surface of the base material 14, or an adhesive is applied to the surface of the base material 14, and the film 26 is You may make it stick to.

FIG. 6 is an enlarged sectional view of a main part of an instrument panel 60 for an airbag according to another embodiment.
This instrument panel 60 is made of a resin base material 14.
This is an instrument panel with a single layer structure consisting only of an instrument panel. In this case, a film 26 is attached to the back side of the door portion 18a of the base material 14. The film 26
Even if it is integrally attached to the base material 14 by in-mold molding,
Alternatively, the base material 14 may be formed in advance, and may be attached to the back surface of the base material via an adhesive.

FIG. 7 is an enlarged sectional view of a main part of an instrument panel 65 for an airbag according to still another embodiment. The instrument panel 65 includes a skin material 66.
This is an instrument panel having a multilayer structure in which the skin material 66 and the base material 14 are integrated by injection molding a resin constituting the base material 14 on the back side of the instrument panel. In this case, the skin material 6
Numeral 6 is obtained by polymerizing and integrating two layers of a skin layer 68 formed of PVC or the like and a buffer layer 69 formed of a polyolefin foam such as foamed PP on the back surface. The skin material 66 may have a single-layer structure.

Also in this case, the door portion 1 on the base material 14
A film 26 is adhered to the back surface side of 8a. This film 26 can be adhered to the back surface of the preformed base material 14 with an adhesive, or the base material 14
When performing injection molding on the back side of the base material, the base material 14 may be integrally attached.

FIG. 8 is a cross-sectional view of an airbag instrument panel 70 according to still another embodiment. In this embodiment, the film 26 is the door portion 1 of the substrate 14.
The embodiment is different from the embodiment shown in FIG. 1 in that it is attached not only to 8a but also to the entire surface of the base material 14. In addition, about the structure similar to the same embodiment, the same referential mark is attached | subjected in a figure, and description is abbreviate | omitted.

In this embodiment, as a method for applying the film 26 to the surface of the base material 14, a method of attaching the film 26 to the surface of the base material 14 formed in advance via an adhesive is preferable, as shown in FIG. is there.

That is, as shown in FIG. 9A, an adhesive is applied to the surface of the preformed base material 14 using a spray means 72 or the like, and this is applied to a forming die 74 capable of vacuum suction. set. On the other hand, the film 26 is
, And is heated using a heater 78. Then, as shown in FIG. 9B, the heated film 26 is put on the surface of the substrate 14, and the molding die 74 is vacuum-sucked to adhere the film 26 to the substrate 14. In addition, through holes are provided at appropriate places in the base material 14 so that the film 26 adheres to the base material 14 by vacuum suction. After the mold release, the edge of the film 26 is cut 80
Thus, the substrate 14 having the film 26 attached on the entire surface is obtained. The obtained base material 14 is set in a foaming mold together with the skin material 12 separately molded, and the foam 16 is foam-molded, whereby the instrument panel 70 is obtained.

When an adhesive layer such as a hot-melt layer is provided on the back surface of the film 26, it is not necessary to apply an adhesive to the surface of the substrate 14; Adhered to.

As described above, the film 26 may be formed not only on the door portion 18a of the base material 14, but also on the entire surface. In addition, if priority is given to cost, it is preferable to form it only on the door portion 18a of the base material 14 as in the above-described embodiment. However, even in the case where the film 26 is formed on the entire surface, the film 26 is sufficiently thin with respect to the base material 14, so that the cost can be sufficiently reduced as compared with the case where expensive resin is used for the base material 14 itself. .

[0037]

According to the instrument panel for an airbag of the present invention, even when a resin having insufficient low-temperature characteristics is used for a substrate, a film excellent in low-temperature characteristics adhered to a door portion of the substrate can be used. In addition, cracking and scattering of the base material at the time of low-temperature cleavage can be prevented. Therefore, while using a cheap or low-grade resin for the base material including the door portion to reduce the cost, the film formed on the door portion can satisfy the door deployment performance at low temperatures.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an instrument panel for an airbag according to one embodiment of the present invention (II enlarged sectional view of FIG. 2);
It is.

FIG. 2 is a perspective view of an instrument panel.

FIG. 3 is a cross-sectional view showing an injection molding step of a base material used for an instrument panel.

FIG. 4 is a cross-sectional view showing a foam molding step of the instrument panel.

FIG. 5 is a cross-sectional view showing a state where a film is applied to a base material.

FIG. 6 is a cross-sectional view of a main part of an instrument panel according to another embodiment.

FIG. 7 is a sectional view of a main part of an instrument panel according to still another embodiment.

FIG. 8 is a sectional view of an instrument panel according to still another embodiment.

FIGS. 9A and 9B are cross-sectional views showing a step of attaching a film to a base material in the instrument panel.

FIG. 10 is a sectional view of a main part of a conventional instrument panel for an airbag.

FIG. 11 is a sectional view of a main part of another conventional instrument panel for an airbag.

[Explanation of symbols]

10 Instrument panel for airbag 12 Skin material 14 Base material 16 Foam 18 Door part 18a Door part of base material 26 Film 30 Airbag device 36 Air Bags 60, 65, 70 ... Instrument panels for airbags

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidehiro Uno 1-17-18 Edobori, Nishi-ku, Osaka-shi, Osaka Toyo Tire & Rubber Co., Ltd. (72) Inventor Hideo Kondo 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor F term in the company (reference) 3D044 BA08 BA11 BA14 BB01 BC04 BD04 3D054 AA03 AA14 BB09 BB17 BB30 FF04 FF16

Claims (4)

[Claims] 1. An airbag instrument panel in which an airbag device is disposed inside, and the airbag device is cleaved with the inflation of the airbag at the time of a vehicle collision to inflate the airbag into a vehicle compartment. The door part that is pushed open by expansion is
It is molded integrally with a resin base material constituting substantially the entire area of the instrument panel, and the base material has at least the door portion, a resin having a lower embrittlement point than the resin constituting the base material. An instrument panel for an airbag, wherein the instrument panel has a film formed thereon. 2. The substrate according to claim 1, wherein the substrate is an injection-molded article of a resin, and the film is integrally attached to the substrate by injection-molding the substrate. Instrument panel for airbags. 3. The film according to claim 1, wherein said film is adhered to a preformed base material via an adhesive.
The described instrument panel for an airbag. 4. The instrument panel for an airbag according to claim 1, wherein a foam is formed between the base material and a skin material forming the surface of the instrument panel.