JP3042981B2 - Instrument panel integrally having airbag door and method of manufacturing the same - 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 having an airbag door and a method of manufacturing the same.

[0002]

2. Description of the Related Art In an automobile, an instrument panel is provided from a lower portion of a front window to a front passenger seat for holding instruments and protecting a passenger.
As the instrument panel, a panel in which a synthetic resin skin is provided 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 a passenger on the passenger seat in the event of an automobile 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 at the time of assembling, as compared with the retrofit-type instrument panel that attaches the airbag door to the opening of the instrument panel. There are no benefits.

FIGS. 14 and 15 show examples of a conventional integrated instrument panel. The instrument panel P has a synthetic resin skin 102 integrally on the surface of the synthetic resin foam layer 101,
At a predetermined position of the skin 102 corresponding to the airbag deployment opening O, a thin-walled breakable portion 105 defining an airbag door D is formed.

The to-be-fractured portion 105 of the skin 102 is formed by pressing a high-frequency welder, a hot blade, a cold press cutter, or the like into the back surface of the skin 102 after the formation of the skin 102 to form a cut or a V-groove. In the drawing, reference symbol A denotes an airbag, C denotes an airbag storage case, and I denotes an actuator. 106 is a core material, 107 is an airbag door core provided on the back surface of the airbag door D, and 109 is an airbag housing case C, the core 106 and the airbag door core 107. The fixing member to be fixed, T, is an imaginary line which is an expected breaking line of the synthetic resin foam layer.

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 Epidermis 102 by pushing force
The stress concentrates on the rupture scheduled portion 105, and the skin 102 and the synthetic resin foam layer 101 break along the rupture scheduled portion,
As shown in FIG. 16, the airbag door portion D opens. FIG.
Reference numerals 105a and 105b denote broken portions of the skin 102, and Ta and Tb denote broken portions of the synthetic resin foam layer. Then, with the opening of the airbag door portion D, the airbag A is deployed in the vehicle interior.

By the way, the instrument panel P
In the outer skin 102, the to-be-ruptured portion 105 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 an interior material such as an instrument panel P of an automobile, the skin 102 deteriorates and shrinks with the passage of time due to the sunlight radiated into the interior of the vehicle and the high heat in the interior of the vehicle. , Its deterioration, shrinkage,
It is known that a thin portion of the skin 102 tends to cause poor appearance such as a crack. Therefore, the expected fracture portion 10
5 is required to be set to a thickness that can prevent poor appearance of the skin and ensure that breakage when the airbag is inflated is made smooth and smooth, and that the thickness is accurately formed.

[0010] However, the conventional scheduled breaking portion 105
After forming the skin 102 as described above, a high-frequency welder, a hot blade, a cold press cutter, or the like is used to form the skin 10.
Since it is formed by pressing the back surface of No. 2 and making a cut or a V-groove, the thickness tends to vary and it is not easy to make the thickness accurate. In addition, a minute notch or the like is easily formed on the back surface of the skin 102 due to the mechanical processing, which is one factor of the crack in the above-mentioned deterioration with time. Further, at that time, since the skin 102 is pressed from the back surface, the surface of the skin 102 may be discolored along the portion 105 to be broken.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and in the case where a breakable portion is provided on the skin of an instrument panel, a variation in thickness and a deterioration factor at the breakable portion are provided. The present invention provides an instrument panel having an airbag door portion having a novel structure, which has a small appearance, has no discoloration at a portion to be broken, has a good appearance, and also reliably breaks when the airbag is inflated, and a method for producing the same. is there.

[0012]

SUMMARY OF THE INVENTION The present invention relates to an instrument panel integrally having an airbag door portion. The invention relates to a synthetic resin skin in which a scheduled break portion defining an airbag door portion is formed on a surface of a synthetic resin foam layer. In the instrument panel integrally having, a flexible elongated skin thin-wall forming member that is non-weld to the skin or weak in welding force is formed in the portion of the skin to be broken ,
Protrude to the back side of the epidermis and form a tapered cross-section wedge
And the thickness between the skin thin-wall forming member and the front and back surfaces of the skin is made smaller than the thickness between the front and back surfaces of the skin in the other part.

Further, the invention relating to a method of manufacturing an instrument panel integrally having an airbag door portion is provided by a synthetic resin.
Expected break to define the airbag door on the surface of the foam layer
Instrument having a synthetic resin skin integrally formed
In the method for manufacturing a skin panel, during the powder slush molding of the skin with the resin material for the skin, the resin material for the skin adheres to the mold surface of the powder slush molding die and a thin molten resin film thinner than a predetermined skin thickness is formed. At the time of the formation, a thin, thin skin-forming member that is not welded to the molten resin film or has a low welding force is formed on the surface of the thin molten resin film, and the edge on the airbag door side is formed. Epidermal
It is placed as a tapered cross-sectional wedge shape projecting to the back side along the portion to be broken of the skin, and then the skin thin material forming member is covered and the skin resin material is further adhered to the thin molten resin film surface. A step of obtaining a synthetic resin skin having a predetermined thickness in which the skin thin-wall forming member is buried in the predetermined portion to be broken, and forming a synthetic resin foam layer by injecting a synthetic resin foam material into the back side of the skin. A step of obtaining an instrument panel integrally having a skin in which a breakable portion defining an airbag door portion is formed.

[0014]

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. FIG. 4 is a cross-sectional view showing the airbag of the embodiment when the airbag is inflated, and FIG. 5 is a perspective view showing a part of the skin thin-wall forming member in the embodiment.

FIG. 6 is a cross-sectional view showing an example of a method of manufacturing an instrument panel integrally having an airbag door portion according to the present invention, which shows a powder slush forming apparatus.
FIG. 7 is a cross-sectional view showing a state in which a thin molten resin film is formed in the same example, FIG. 8 is a cross-sectional view showing a state in which a skin thin-wall forming member is placed, FIG. 9 is an enlarged cross-sectional view of a portion 9 in FIG. FIG. 10 is a cross-sectional view showing the embedding of the skin thin-wall forming member, FIG. 11 is an enlarged cross-sectional view of part 11 of FIG. 10, and FIG. 12 shows a case where a synthetic resin foam material is injected into the back side of the skin in the embodiment. FIG. 13 is a sectional view showing the foam molding state.

The instrument panel 20 shown in FIGS. 1 to 3 integrally has a skin 22 in which a breakable portion 25 defining an airbag door portion D1 is formed on the surface of a synthetic resin foam layer 21. The airbag door portion D1 in this embodiment is a single-opening type, and the breakable portion 25 is formed in a substantially U-shape as shown in FIG. 1, but the airbag door portion is a double-opening type. , A breakable portion is formed in a substantially H shape. Reference numeral T1 denotes an expected break line of the synthetic resin foam layer 21, and reference numeral 30 denotes an instrument panel 2.
0 core material. The airbag device attached to the instrument panel 20 has the same structure as that described in the section of the prior art, wherein reference numeral A denotes an airbag, I denotes an airbag operating device, and C denotes an airbag. It is a storage case.

The synthetic resin foam layer 21 imparts cushioning to the instrument panel, and is made of polyurethane foam or the like. A slit 21a is formed on the back surface of the skin 22 at a position corresponding to the portion 25 to be broken, and air is blown. When the bag is inflated, it breaks from the slit 21a.

The skin 22 is composed of the 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 shape by known powder slush molding.

As is better understood from FIG. 3, a thin and long skin forming member 27 is buried in the cut portion 25 of the skin 22, as is better understood from FIG. The skin thin-wall forming member 27 is made of a flexible material so as not to impair the feel of the skin 22, and is non-welded or weakly welded to the skin 22, and the surface of the skin thin-wall forming member 27 and the surface of the skin 22 are formed. The thickness d1 between the upper surface 22a and the thickness d2 between the upper surface 22b and the rear surface 22b is smaller than the thickness d3 between the upper surface and the lower surface in another portion of the outer skin 22. Thereby, the epidermis 22
Of the airbag A
When the to-be-ruptured part 25 is pushed up from the back side by the expansion of the slab, it can be quickly broken. In this example, d
1, d2 is about 0.5 mm and d3 is about 1 mm.

The skin thin-wall forming member 27 is buried in a molten resin film adhered to a mold surface of a powder slush molding die during powder slush molding of the skin 22, as described later. It is formed of a material that does not adhere to the film or a material that has a low welding force. The skin thin-wall forming member 27 and the skin 22 are not limited to those made of different materials, but may be made of the same kind of material. In this embodiment, the outer skin 22 is made of a soft vinyl chloride resin, whereas the thin skin forming member 27 is not fused with the soft vinyl chloride resin that does not melt at the temperature at the time of powder slush molding of the outer skin 22. Elastomer (T
PO). In addition, the skin thin-wall forming member 27 is the skin 2
2 and the color of the skin thin-wall forming member 27 is
It is preferable not to be transparent from the surface. On the other hand, as an example of the skin thin-wall forming member having a weak welding force, when the skin 22 is made of soft vinyl chloride resin, the skin thin-wall forming member 2
7 is formed from a mixture of a soft vinyl chloride resin and a thermoplastic polyolefin-based elastomer.

The skin thin-wall forming member 27 of this embodiment
As shown in FIG. 3 and FIG. 5, a locking hole 28 is formed at a predetermined interval through a thin and long plate-like body (0.7 mm in thickness and 10 mm in width), and a skin is formed in the locking hole 28. 22 synthetic resins have entered. This locking hole 28
The skin thin-wall forming member 27 that is not welded or weakly welded to the skin 22 is securely fixed in the scheduled break portion 22 of the skin 22, and when the skin 22 breaks at the scheduled break portion 22, the skin thin-wall forming member 27 is removed. Separation from the epidermis 22 prevents scattering.

Further, the skin thin-wall forming member 27 in this embodiment has an edge 27a on the airbag door D1 side.
However, it projects to the back side of the skin 22 and has a tapered cross-sectional wedge shape. As a result, the skin thin-wall forming member 27
The tip of the wedge-shaped edge 27a is the rear surface 22b of the skin 22.
, The back side of the rupturable portion 25 becomes thinner, so that the inflatable airbag A inflates the rupture portion 25 very quickly.

If the thin skin forming member 27 is formed of a material harder than the skin 22, the thin skin forming member 2 can be formed.
7, the strength of the skin 22 changes greatly at the edge 27a, and therefore the portion 2 to be broken when the airbag is inflated.
5 is easier to break. Further, in this case, the wedge-shaped edge 27a functions as a knife, and
, Thereby breaking the portion to be broken 25 more smoothly.

The core member 30 includes the instrument panel 2
No. 0 is used to reinforce the back surface, 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 31 is formed at a position corresponding to the airbag door portion D1,
An airbag door core 33 made of a metal or a resin plate is bent in the airbag deployment opening 31 toward the outer skin 22 by the pressure caused by the expansion of the airbag A, and the airbag deployment opening 31 can be opened. As shown in FIG.
Installed with. Instead of this, a slit, a V-groove or the like is formed on the surface of the core material 30 corresponding to the edge of the core material 33 for the airbag door portion, and a portion of the core material 30 surrounded by the slit or the V-groove or the like. Thus, the airbag door portion core material 33 may function.

In the instrument panel 20 having the above-described structure, the cut portion 25 of the skin 22 is
The surface 22a of the skin 22 at the portion 25 to be broken and the skin thin-wall forming member 27 are buried in the inside thereof with the skin 22 which is not welded to the skin 22 or has a weak welding force.
Between the back, the back surface 22b of the skin 22 and the skin thin-wall forming member 2
Since the thickness of each of the portions 7 is made thinner, the thickness of the portion 25 to be ruptured is small, and the thickness of the portion 25 to be ruptured is small, unlike a device in which a hot blade or a cutter is pressed against the back surface of the skin to form a thin portion. It does not have a fine notch or the like, which is a factor of the above, does not cause discoloration or the like due to the pressing of the skin, and has a good appearance.

In the instrument panel 20, when the airbag device is operated, as shown in FIG. 4, the push-up force due to the inflation of the airbag A causes the airbag door core 33 and the synthetic resin foam. Epidermis 2 through layer 21
2 and the rupture portion 25 is ruptured, and the synthetic resin foam layer 21 is ruptured from the slit 21a. As a result, the instrument panel 20 breaks along the predetermined breaking line T1, the airbag door portion D1 is smoothly pushed open into the vehicle interior, and the airbag A is deployed.

Next, an example of a method of manufacturing an instrument panel having the above structure will be described with reference to FIGS. The same members as those described above are denoted by the same reference numerals. This manufacturing method includes a step of obtaining a skin in which a skin thin-wall forming member is embedded in a portion to be broken and a step of obtaining an instrument panel integrally having a synthetic resin skin in which a portion to be broken defining an airbag door portion is formed. And

In the step of obtaining the skin, as shown in FIGS. 6 and 7, a known powder slush molding method using a powder slush molding die 50 is used. In this step, first, as shown in FIG. 6, the powder accommodating portion 5 of the bucket 51 combined with the powder slash molding die 50 is used.
2 stores a skin resin material 60 made of a thermoplastic resin powder such as a soft vinyl chloride resin.

Next, the bucket 51 and the mold 50 are rotated a predetermined number of times as indicated by an arrow a while heating the mold 50 by supplying a heat medium such as heating oil to the heat circulation pipe 53.
The rotation causes the skin resin material 60 in the bucket 51 to adhere to the mold surface 54 of the molding die 50 and is melted by the heat of the mold surface 54 as shown in FIG. To form a thin molten resin film 61 thinner than the thickness of the resin film 61. When the thickness of the target skin 22 is 1 mm, the thin molten resin film 61 in this embodiment has a thickness of about 0.5 mm.
mm.

When the thin molten resin film 61 is formed on the mold surface 54, the rotation of the mold 50 and the bucket 51 is temporarily stopped, and the bucket 51 is removed from the mold 50.
Then, as shown in FIG. 8 and FIG. 9 which is an enlarged view of the nine portions thereof, the surface of the thin molten resin film 61 formed on the mold surface 54 is formed along a portion to be a fractured portion of the skin. The skin thin-wall forming member 27 is placed. At this time, the skin thin-wall forming member 27 is configured such that the wedge-shaped edge 27a faces the airbag door D1 surrounded by the breakable portion 25 shown in FIG. 1 and the like, and the tip of the edge 27a is a thin layer. From the surface 61a of the molten resin film 61 (upward in FIGS. 8 and 9).

Then, as shown in FIG. 10 and FIG. 11 in which the 11 part is enlarged, the bucket 51 and the forming die 50 are combined and rotated again to cover the skin thin-wall forming member 27 and to form a thin molten resin film. A skin resin material 60 is further adhered on the surface of 61 in a layer shape having a thickness of 5 mm in this example, and a molten resin film 62 having a predetermined thickness integrated with the thin molten resin film 61 is formed. At this time, the thin skin forming member 27 is non-welded or weakly welded to the molten resin film 62. Then, the mold 50 is cooled to cure the molten resin film 62, and the skin 22 is
Demold from 0. The to-be-broken portion 25 is formed in the thus obtained skin 22 as described above, and thereby the airbag door portion D1 is defined.

Next, a step of obtaining an instrument panel integrally having the skin 22 is performed. In this process,
First, as shown in FIG. 12, the skin 22 is arranged on the mold surface 73 of the lower mold 71 of the foaming mold 70 so that the back surface faces inward (upward). On the mold surface 74, the core member 30 to which the airbag door core member 33 is attached is held and arranged by appropriate means.

Then, after a predetermined amount of a synthetic resin foam material 81 such as a polyurethane raw material is injected from the head 80 of the injector into the back side of the skin 22 of the lower mold 71, the upper mold 72 is closed and foam molding is performed. As a result, the synthetic foamed foam material 81 foams and hardens to form the synthetic resin foamed layer 21, and the instrument panel integrally has a surface 22 on which a breakable portion 25 defining the airbag door portion D <b> 1 is formed. 20 is obtained.

As described above, according to the above-described manufacturing method, the instrument panel having the skin in which the non-adhesive or the thin skin-forming member having a low welding force is embedded in the surface to be broken is integrally formed on the surface of the synthetic resin foam layer. Can be obtained simply and easily. Moreover, since the portion of the skin to be broken is not formed by pressing a cutter or the like after the skin is formed, the thickness has little variation, does not have a fine notch or the like that causes deterioration, and there is no discoloration or the like. The appearance is good.

[0035]

As shown and described above, according to the instrument panel of the present invention, in the portion of the skin to be broken, the thin-wall forming member that is not welded to the skin or has a weak welding force is provided with the airbag. Edge on the door side is the back of the skin
It is buried as a tapered cross-sectional shape protruding to the side, and the thickness between the front and back surfaces of the part to be broken and the thin skin forming member is reduced, so the airbag inflates quickly at the part where the skin is to be broken And the airbag door opens smoothly.

Furthermore, according to the instrument panel of the present invention, the portion of the skin to be broken is not formed by pressing the cutter or the like after the skin is formed. It has no notch, no discoloration, etc., and has good appearance.

Further, according to the manufacturing method of the present invention, an instrument panel having the above-mentioned effect can be obtained easily and easily with a constant quality.

[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 sectional view taken along line 2-2 of FIG.

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

FIG. 4 is a cross-sectional view showing the airbag of the embodiment when inflated.

FIG. 5 is a perspective view showing a part of the skin thin-wall forming member in the embodiment.

FIG. 6 is a sectional view of a powder slush molding apparatus used in an example of the production method of the present invention.

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

FIG. 8 is a cross-sectional view showing a state where the skin thin-wall forming member is placed in the embodiment.

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

FIG. 10 is a cross-sectional view showing a state where the skin thin-wall forming member is embedded in the embodiment.

FIG. 11 is an enlarged sectional view of a portion 11 in FIG. 10;

FIG. 12 is a cross-sectional view showing a state at the time of injecting a synthetic resin foam material in the example.

FIG. 13 is a cross-sectional view showing the synthetic resin foam material in the same example when foamed.

FIG. 14 is a cross-sectional view of a main part of an instrument panel having a conventional airbag door.

15 is an enlarged view of a portion 15 in FIG.

FIG. 16 is a cross-sectional view showing a state where an airbag door portion is opened in a conventional instrument panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Synthetic resin foam layer 22 Synthetic resin skin 25 Expected break portion 27 Skin thin-wall forming member 28 Locking hole 30 Core material 31 Airbag deployment opening 33 Core material for airbag door D1 Airbag door

Claims (2)

(57) [Claims] 1. An instrument panel having a synthetic resin skin integrally formed on a surface of a synthetic resin foam layer with a rupture portion defining an airbag door portion, wherein the skin is included in the rupture portion of the skin. weak flexible elongated skin thin member of a non-weldable or welding force, the
The tapered edge of the airbag door that projects to the back of the skin
An airbag door portion embedded in a wedge-shaped cross section, wherein the thickness between the skin thin-wall forming member and the front and back surfaces of the skin is smaller than the thickness between the front and back surfaces of the skin in the other portion. Instrument panel with a. (2)Airbagged on the surface of the synthetic resin foam layer
Synthetic resin skin with a ruptured part that defines the part
In the method of manufacturing an instrument panel with
And  Powder slush molding of skin with resin material for skin
When the powder slush mold is used, the surface resin
A thin layer of molten wood that is thinner than the specified skin thickness due to the adhesion of material
When the grease film is formed, the surface of the thin molten resin film is
On the surface, it is non-weldable or has low welding power with the molten resin film.
Flexible thin and thin skin forming member, Airbag door
The edge that becomes the side has a tapered cross-sectional wedge shape that projects to the back side of the epidermis
do itPlace along the part of the skin that will be broken, and then
And covering the thin skin forming member with a thin molten resin film
A further surface resin material is adhered to the surface,
Synthesizing of predetermined thickness with skin thin forming member embedded in fixed part
A step of obtaining a resin-made skin;
By forming a fat foam layer, the airbag door section is
Having an integral skin with a predetermined fracture
Obtaining a instrument panel.
Instrument panel with an airbag door
Manufacturing method.