JP3042984B2 - Instrument panel with integrated airbag door - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an instrument panel integrally having an airbag door.

[0002]

2. Description of the Related Art An instrument panel is provided from a lower portion of a front window of an automobile to a front passenger seat for holding instruments and protecting a passenger. As the instrument panel, a panel provided with a synthetic resin skin on the surface of a synthetic resin foam layer is frequently used.

[0003] In recent years, an airbag device has been provided on the rear surface of the instrument panel on the passenger seat side to protect an occupant in the passenger seat in the event of a car collision. In the airbag device, a folded airbag is housed in an airbag housing case called a canister together with an actuating device called an inflator. The upper portion of the airbag storage case is an opening for deploying the airbag into the vehicle interior, and the opening is covered with an airbag door. Then, the operating device is activated by the collision of the automobile, and the inflated airbag pushes the airbag door portion open from behind and deploys into the vehicle interior.

As an instrument panel to which the airbag device is attached, there is an instrument panel in which an airbag door portion is formed integrally with the instrument panel. This one-piece instrument panel has problems such as the inconvenience of assembling the airbag door and the variation in assembling, compared to the retrofit-type instrument panel that attaches the airbag door to the opening of the instrument panel. There are no advantages.

FIG. 16 and FIG. 1 showing a cross section of an example of a conventional integrated instrument panel are shown.
7 is shown. This instrument panel P
Has a synthetic resin skin 72 integrally on the surface of the synthetic resin foam layer 71, and the skin 7 corresponding to the airbag deployment opening O.
A predetermined break portion 75 defining an airbag door portion D is formed at the predetermined position of No. 2. In this example, the breakable portion 75 is formed in an H shape as shown in the figure, and defines two airbag door portions D, D.

The portion 72 to be broken of the skin 72 is
After the molding of 2, the high frequency welder, a hot blade, a cold press cutter, or the like is pressed against the back surface of the skin 72 to make a cut or a V-groove to make the portion of the skin 72 thin. In the drawing, reference symbol A denotes an airbag, C denotes an airbag storage case, and I denotes an actuator. Also, reference numeral 76
Is a core material for an instrument panel, 77 is a core material for an airbag door portion provided on the back surface of the airbag door portion D, 7
Reference numeral 9 denotes a fixing member for fixing the airbag housing case C, the instrument panel core 76 and the airbag door core 77.

In the instrument panel P having this structure, as described above, when the airbag A is operated and inflated, the airbag door portion D above the airbag deployment opening O is pushed from the back side, and the The pushing force concentrates stress on the rupture portion 75 of the skin 72, and the skin 72 and the synthetic resin foam layer 71 break along the rupture portion 75 to open the airbag door portion D. Then, with the opening of the airbag door portion D, the airbag A is deployed in the vehicle interior.

[0008] By the way, in the skin 72, the breakable portion 75 defining the airbag door portion D can be more reliably and smoothly broken when the airbag is inflated as the thickness thereof is reduced. In general, in the case of interior materials such as instrument panels of automobiles, the skin 72 deteriorates and shrinks with the passage of time due to the sun rays radiated into the cabin and the high heat inside the cabin. It is known that the surface of the skin 72 is apt to cause poor appearance such as cracks by concentrating on a thin portion of the skin 72. Therefore, the breakable portion 75 needs to be set to a thickness that does not cause the appearance defect of the skin and that the breakage during the inflation of the airbag can be performed reliably and smoothly, and that the thickness is accurately formed.

However, since the average thickness of the skin 72 is extremely thin, about 0.8 to 1.2 mm, the conventional method tends to cause a variation in the thickness of the portion 75 to be broken, and it is difficult to improve the accuracy. In addition, when forming the to-be-ruptured portion 75 by using a high-frequency welder or a hot blade, the skin
Is pressed from the back surface, and the skin 72 may be discolored along the expected break portion 75 in some cases. Therefore, in order to reliably prevent cracks and discoloration from occurring in the breakable portion 75 and to increase the durability of the instrument panel, it is necessary to use the outer skin 72.
It is desirable not to provide such a thin portion as much as possible.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and does not provide a thinned portion of the skin of the instrument panel, has a good appearance, and does not have a risk of discoloration. And once the airbag is inflated, the airbag door can be securely and smoothly
An object of the present invention is to provide an instrument panel integrally having a novel airbag door portion that can be accurately opened.

[0011]

That is, an instrument panel of the present invention having an airbag door unit integrally has a skin having a breakable portion laminated on the surface of a synthetic resin foam layer, and the skin portion having the breakable portion is formed by the breakable portion. In an instrument panel integrally having a defined airbag door portion, the skin comprises a powder slash molded product,
During the powder slush molding,
Backing resin with both slit and air vent
The seat is adhered and integrated on the back surface of the skin, and the strength of the portion of the skin that is to be broken is made lower than the strength of the surrounding area by the slit.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view of an instrument panel integrally having an airbag door portion according to one embodiment of the present invention, FIG. 2 is a 2-2 sectional view thereof, and FIG. 3 is an enlarged sectional view of three portions of FIG. 4 is a perspective view of the backing resin sheet used in the example, and FIG. 5 is a sectional view taken along line 5-5.

FIGS. 6 to 11 show examples of manufacturing the skin used in the embodiment. FIG. 6 is a sectional view showing a powder slush molding apparatus, and FIG. 7 is a view showing the formation of a resin film in the embodiment. FIG. 8 is a cross-sectional view in which a backing resin sheet is adhered to the back surface of the skin in the same example, and FIG.
Is an enlarged perspective view of a main part thereof, FIG. 10 is a cross-sectional view of the obtained skin, and FIG. 11 is a cross-sectional view showing a cross section of a bridge portion of the backing resin sheet.

FIGS. 12 and 13 show an example of manufacturing an instrument panel according to the present invention. FIG. 12 is a sectional view showing a state in which a foaming material is injected into a foaming mold.
FIG. 13 is a cross-sectional view showing the mold clamping.

FIG. 14 is a perspective view showing another example of the backing resin sheet used in the present invention, and FIG.
It is -15 sectional drawing.

As shown in FIGS. 1 to 3, the instrument panel 10 of the present invention has a synthetic resin foam layer 11 and a surface 12 having a rupture portion 13 defining an airbag door portion D on the surface thereof. It is laminated. The airbag door portion D provided on the instrument panel 10 of this example is of a double-opening type, and the breakable portion 13 is formed in a substantially H shape as shown in FIG. The shape of the breakable portion 13 is appropriately determined according to the shape of the airbag door portion D.

Further, the instrument panel 10 of this embodiment is provided with an instrument panel core 20 on the back surface of the synthetic resin foam layer 11. This core material 20
Is used to reinforce the back surface of the instrument panel 10, and is formed by injection molding or the like from hard vinyl chloride resin, polypropylene, or the like. In this embodiment, an airbag deployment opening 22 is formed at a position corresponding to the airbag door portion D, and an airbag door core 21 made of a metal or resin plate is provided in the airbag deployment opening 22. Pressing the bag A inflates the skin 12
It is attached by an attachment member 25 so that it can bend to the side to open the airbag deployment opening 22. Instead of this, a slit or V-groove or the like is formed on the surface of the instrument panel core 20 corresponding to the edge of the airbag door core 21 and the core surrounded by the slit or V-groove or the like. The portion of the material 20 may function as the core material 21 for the airbag door portion.

The airbag device attached to the instrument panel 10 has the same structure as that described in the section of the prior art. Reference symbol A denotes an airbag, I denotes an airbag operating device, and C denotes an airbag operating device. Is an airbag storage case.

The synthetic resin foam layer 11 imparts cushioning to the instrument panel and is made of a polyurethane foam or the like. The instrument panel core material 20 and the airbag door core material 21 have a predetermined thickness on one surface. Is formed. In this embodiment, as can be understood from FIG. 3, a cut 2 is made in the core material 21 for the airbag door along the position of the rupture scheduled portion 13 of the instrument panel 10.
1a, and V-grooves 11a, 11a are provided in the synthetic resin foam layer 11 through the cuts 21a. Thereby, the strength of the synthetic resin foam layer 11 in the portion 13 to be broken is reduced, the pressure at the time of inflation of the airbag is concentrated on the portion 13 to be broken, and the opening of the airbag door portion D is made smoother and faster. I do it.

The skin 12 is composed of an instrument panel 20.
Of soft vinyl chloride resin (PV
C) or a thermoplastic polyurethane resin (TPU) or the like, and is formed into a predetermined instrument panel surface shape by known powder slush molding.

As can be understood from FIG. 2 and FIG. 3 which is an enlarged view of three parts, the backing resin sheet 15 is integrally attached to the back skin of the airbag door portion D. The backing resin sheet 15 has excellent durability against deterioration due to the temperature in the passenger compartment and the sun's rays, and forms the rupture scheduled portion 13 that reliably and smoothly breaks when the airbag is inflated without providing a thin portion on the skin 12. It is for doing. The backing resin sheet 1
The boundary line B (shown in FIG. 3) between the surface 5 and the back surface of the skin 12 is shown in the present embodiment in which the skin 12 is formed by powder slush molding and the backing resin sheet 15 is adhered to the back surface of the skin 12 at the time of molding. Usually, it is unclear or does not appear, but it is clearly shown for easy understanding.

The backing resin sheet 15 is formed of a resin sheet having an appropriate thickness, and as shown in FIG.
It is formed sufficiently larger than the airbag door portion D.
The backing resin sheet 15 is formed with a slit 16 having a shape that matches the breakable portion 13 of the airbag door portion D. The slit 16 forms a portion 13 to be ruptured of the skin 12 and makes the strength of the portion 13 to be ruptured relatively lower than its surroundings. A strong stress concentration occurs in the scheduled fracture portion 13 to
To ensure that it can be broken.

Although the width of the slit 16 is not particularly limited, it is difficult to align the slit 16 with a predetermined position of the breakable portion 13 if it is too narrow. On the other hand, if the width is too wide, the difference in strength between the portion to be broken 13 and the periphery thereof cannot be remarkable. In this embodiment, it is about 6 to 10 mm.

The backing resin sheet 15 has good adhesiveness when adhered to the back surface of the skin 12,
It is desirable to use a material that does not impair the feel of 2 and is flexible so as to conform to the surface shape of the skin 12, and is appropriately selected according to the material forming the skin 12. For example, when the skin is made of a soft vinyl chloride resin, the backing resin sheet is preferably a semi-rigid vinyl chloride resin. In the case where a polyolefin-based thermoplastic elastomer is used for the skin, polyethylene or polypropylene is preferable. The thickness of the backing resin sheet 15 is not particularly limited, but if it is too thick, the feel of the surface of the skin 12 may be impaired, and if it is too thin, the reinforcement around the slit 16 becomes insufficient. In the present embodiment, the same resin sheet as the skin 12 is cut into an appropriate size and used, and its thickness is about 1 mm.

The backing resin sheet 15 of this embodiment
Is attached to the back surface of the skin 12 at the time of powder slush molding of the skin 12, and before the attachment, as shown in FIG. 4 and FIG. Bridges 17 are formed in the slit 16 at appropriate intervals to prevent the spread of the light. The bridge 17 is necessary particularly when the backing resin sheet 15 is formed of a flexible material like the skin 12, and is easily deformed during the attaching operation. The bridge 1
7 is appropriately cut after the sticking operation. Further, small holes 18 for venting air are formed in the backing resin sheet 15 of this example. The small holes 18 for air release are formed in the backing resin sheet 15.
To prevent air from intervening between the skin 12 and the backing resin sheet 15 at the time of sticking work, and to achieve close contact between the skin 12 and the backing resin sheet 15. The thickness and material of the backing resin sheet 15 An appropriate size and number are provided depending on the size, size, and the like. In this example, a hole with a diameter of 3 to 5 mm is about 20 m
They are provided at m intervals.

In the instrument panel 10 having such a structure, a backing resin sheet 15 having a slit 16 formed along a breakable portion 13 is adhered to the back surface of the airbag door portion D of the skin 12. So the epidermis 12
In the vicinity of the airbag door portion D, the portion other than the rupture scheduled portion 13 is reinforced.
Thereby, the thickness is relatively thinner than the surrounding portion, and the strength is reduced. Therefore, even if a thin portion such as a V-groove, which causes deterioration, is not provided on the skin 12, the same operation as if a thin breakable portion is provided on the skin 12 can be obtained. Moreover, since the strength of the rupture scheduled portion 13 can be determined by the thickness of the backing resin sheet 15 and the size of the slit 16, the rupture scheduled portion having a certain strength is different from the rupture scheduled portion such as a V groove formed by a high frequency welder or the like. 13 is easy to obtain. Therefore, the durability of the instrument panel is greatly improved without impairing the opening of the airbag door and the deployment of the airbag in the cabin, and preventing the occurrence of deterioration, cracks, discoloration, etc. due to the thinner skin. Can be improved.

Next, an example of manufacturing the skin 12 by powder slush molding and an example of manufacturing an instrument panel using the skin will be described. At the time of skin formation, as shown in FIG. 6, a resin material 40 for skin made of a thermoplastic synthetic resin powder such as soft vinyl chloride is stored in a powder storage portion 32 of a bucket 31 in a powder slush molding device 30.

Then, a heating medium such as heating oil is supplied to the heating medium circulation pipes 35, 35,... To heat the forming mold 33 formed in a predetermined surface shape of the skin, and the bucket 31 and the forming mold are heated. 33 and is rotated a predetermined number of times as shown by the arrow in the figure. Due to the rotation, as shown in FIG.
And contacts the mold surface 34. The skin resin material 40 is melted and adhered by the heat of the mold surface 34,
A resin film 12a having a predetermined thickness is formed on the mold surface 34 in a layer shape. The thickness of the resin film 12a of this embodiment is about 1.0 mm.

Subsequently, the bucket 31
As shown in FIG. 8 and FIG. 9 in which a part thereof is enlarged, the backing resin sheet 15 previously shown in FIG. 4 and FIG.
Is adhered so as to cover the portion of the resin film 12a formed on the mold surface 34 to be the airbag door portion. The backing resin sheet 15 is formed with the slit 16 having a shape corresponding to the portion to be broken 13 as described above, and the slit 16 is arranged on the resin film 12a so as to match the position to be the portion to be broken 13 of the skin. Is done. This backing resin sheet 1
The arrangement of 5 is preferably performed while the skin is still the resin coating 12a in the molten state on the mold surface 34. Thereby, the backing resin sheet can be firmly joined to the back surface of the skin. Further, depending on the material and thickness of the resin film 12a of the mold surface 34 and the backing resin sheet 15, the molding die 33 may be heated again to melt the backing resin sheet 15 and be integrally adhered to the back surface of the skin.
Further, a suitable adhesive or the like may be interposed between the backing resin sheet 15 and the resin film 12a.

Then, the molding die 33 is cooled, the molten resin film 12a to which the backing resin sheet 15 is adhered is cured, and the skin 12 is released from the molding die 33. Then, in this example, as shown in FIGS. 10 and 11,
Bridge 1 provided on backing resin sheet 15
7 is cut. A backing resin sheet 15 having a slit 16 formed on the back surface of the airbag door portion of the skin 12 along the portion to be broken 13 is integrally attached to the back surface.

Next, a method of manufacturing an instrument panel using the skin 12 will be described. In this embodiment, a manufacturing method by an open injection method is shown. However, the panel of the present invention is not limited to this method, and can be obtained by using a closed injection method or the like. First, as shown in FIG. 12, the mold surface 52 of the lower mold 51 of the foam molding mold 50 is formed.
Then, the outer skin 12 is arranged such that the backing resin sheet 15 is inward (upward). On the other hand, on the mold surface 54 of the upper mold 53 of the foam molding mold 50, the core material 2 for the airbag door portion is provided.
1. Instrument panel core material 20 attached
Is held and arranged by appropriate means. And, the lower mold 51
After injecting a predetermined amount of a foaming material 61 such as a polyurethane raw material from the head 60 of the injector into the back side of the skin 12 of FIG.
As shown in FIG. 7, the upper mold 53 is closed, the foam material 61 is foamed and hardened, and the synthetic resin foam layer 11 is integrally formed on the back surface of the skin 12. Thereafter, the mold is opened, and the desired instrument panel is released. In the airbag door portion of the obtained instrument panel, due to the slits 16 of the backing resin sheet 15 adhered to the back surface of the skin 12, a breakable portion 13 whose strength is relatively lower than that of the surroundings is formed. ing.

As described above, the skin 12 used for the instrument panel 10 can be easily obtained by attaching the backing resin sheet 15 to a predetermined position at the time of powder slush molding of the skin. All of the steps and equipment for forming the breakable portion are unnecessary, and the instrument panel can be manufactured rationally and efficiently.

FIGS. 14 and 15 show another example of the backing resin sheet. Reference numeral 15A is a backing resin sheet, 16A is a slit, and 18A is a small hole for venting air. The slit 16 </ b> A shown in this example is formed of intermittent perforations formed along the portion to be broken. According to this structure, since the gap 17A between the perforations has the same function as the bridge 17 of the backing resin sheet 15 described above, there is no need to form a bridge, and the perforations are not formed after the skin is formed. There is no need to cut the interval 17A.
The size of this perforation is not particularly specified, and in this example, the length is
Perforations of 30 to 40 mm and width of 6 to 10 mm are formed continuously at intervals of about 2 to 3 mm.

[0034]

As shown and described above, according to the instrument panel of the present invention, the skin is powder slurry.
Powder slush molding
Occasionally, slits and small holes for air release
Backing resin sheet with both is integrated on the back of the skin
Have been. As a result, the backing resin
Is firmly joined, and the portion of the skin
And lower strength. Therefore, in the epidermis,
Since it is not necessary to form a thin portion due to a V-groove notch or the like that causes deterioration in the portion to be broken, the appearance of the instrument panel can be kept long and good without causing cracks in the skin due to deterioration over time. Moreover, once the airbag is inflated, the stress concentrates on the portion to be broken, which is made lower in strength than the surroundings by the slit, so that the portion of the skin to be broken is broken quickly and reliably, and the airbag door is released smoothly. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view of an instrument panel integrally having an airbag door portion according to an embodiment of the present invention.

FIG. 2 is a 2-2 cross-sectional view thereof.

FIG. 3 is an enlarged sectional view of three parts in FIG. 2;

FIG. 4 is a perspective view of a backing resin sheet used in the embodiment.

FIG. 5 is a sectional view taken along line 5-5.

FIG. 6 is a cross-sectional view showing a production example of a skin, and showing a powder slush molding apparatus.

FIG. 7 is a cross-sectional view showing a state in which a resin film is formed in the same example.

FIG. 8 is a cross-sectional view in which a backing resin sheet is adhered to the back surface of the skin in the example.

FIG. 9 is an enlarged perspective view of a main part thereof.

FIG. 10 is a cross-sectional view of the obtained epidermis.

FIG. 11 is a cross-sectional view showing cutting of a bridge portion of the backing resin sheet.

FIG. 12 is a view showing a production example of the instrument panel of the present invention, and is a cross-sectional view showing a state where a foaming material is injected into a foaming mold.

FIG. 13 is a cross-sectional view showing a closed state of the foam molding die.

FIG. 14 is a perspective view showing another example of the backing resin sheet.

FIG. 15 is a sectional view taken along line 15-15 of FIG.

FIG. 16 is a perspective view of an instrument panel integrally including a general airbag door.

FIG. 17 is a sectional view taken along line aa of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Instrument panel 11 Synthetic resin foam layer 12 Skin 13 Expected breakage 15 Backing resin sheet 16 Slit D Airbag door

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-48202 (JP, A) JP-A-5-38995 (JP, A) JP-A 9-156445 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B60R 21/045 B60R 21/20

Claims (1)

(57) [Claims] 1. An instrument panel comprising a synthetic resin foam layer and a skin having a rupture portion laminated on a surface of the synthetic resin foam layer and integrally having an airbag door portion defined by the rupture portion, wherein the skin is formed by powder slush molding. Made of goods
During powder slush molding, the slash
Backing resin sheet with both lit and air vent small holes
An instrument panel integrally provided with an airbag door portion, wherein the airbag door portion is adhered and integrated on the back surface of the skin, and the strength of a portion to be broken of the skin is made lower than the surrounding strength by the slit.