JPH092181A - Air bag cover - Google Patents

Abstract

PURPOSE: To provide an air bag cover to facilitate formation of a break scheduled part even in a decorative sheet having a skin layer and arranged on a core surface. CONSTITUTION: A folded air bag is covered with an air bag cover 10, and a break scheduled part 16 broken to protrude the air bag during expansion is formed. The air bag cover comprises a core 11; and a decorative sheet 12 arranged on the surface side of the core 11. The decorative sheet 12 comprises a skin layer 13 on the surface side of the decorative sheet 12; a barrier layer 14 formed on the back side of the decorative sheet 12 and for protecting the skin layer 13 during injection-molding of the core 11. The break scheduled part 16 comprises a recessed part 16a formed on the back side of the core 11; a cut part 16b formed in the barrier layer 14 of the decorative sheet 12; and a pin hole 16c extending through the skin layer 13 of the decorative sheet 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air bag cover for an automobile instrument panel, a door trim, a seat back, a steering wheel pad, etc., which covers a folded air bag of an air bag device. The present invention relates to an airbag cover made of a synthetic resin, in which a to-be-broken portion to be broken for projecting a bag is arranged, and a decorative sheet is arranged on a surface side of a core material.

[0002]

2. Description of the Related Art Conventionally, as an airbag cover of this type, a core material made of a synthetic resin and a decorative sheet provided on the surface of the core material in consideration of the design of the interior member in the peripheral portion are used. It was configured (see Japanese Utility Model Laid-Open No. 63-22262, etc.).

In order to make the airbag rupture when the airbag is inflated and to project the airbag, the airbag cover is
A part to be broken was formed. This portion to be broken was formed by forming a recess in the airbag cover by a processing jig using high frequency, heat, and ultrasonic waves (Japanese Patent Laid-Open No. 2-248).
238, JP-A-4-151345, JP-A-6-218811).

[0004]

If this recess is provided on the front surface side of the airbag cover, it will reduce the designability of the airbag cover, so it is provided on the back surface side, and
In order to break the airbag cover smoothly, it is necessary to provide it on the decorative sheet.

In this case, as the decoration sheet, an outer skin layer made of soft vinyl chloride or the like is arranged on the front surface side of the decoration sheet, and is arranged on the back surface side of the decoration sheet to prevent heat and injection pressure during injection molding of the core material. A barrier layer made of polypropylene or the like for protecting the outer skin layer and, if necessary, a foam layer made of expanded polypropylene or the like interposed between the outer skin layer and the barrier layer for improving the feel are laminated and integrated. When a sheet material is used, it is necessary to form recesses not only on the barrier layer but also on the back surface side of the outer skin layer.

However, the skin layer has a thickness of 1 mm.
The front and back are thin, and it is not easy to control the thickness of the outer skin layer when forming the recess. In particular, the airbag cover often has a curved surface due to the requirement of a design shape, and a portion to be fractured is formed on the curved surface, so that it is very difficult to control the thickness of the outer skin layer.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an airbag cover which is provided with an outer skin layer and can easily form a breakable portion in a decorative sheet arranged on the surface of a core material. And

[0008]

An airbag cover according to the present invention comprises a core material and a decorative sheet arranged on the surface side of the core material, and the decorative sheet comprises:
A folded air bag that is configured by including an outer skin layer on the front surface side of the decorative sheet and a barrier layer disposed on the rear surface side of the decorative sheet for protecting the outer skin layer during injection molding of the core material. And an airbag cover made of a synthetic resin in which a planned breaking portion for breaking the airbag when inflated is arranged, wherein the breaking portion is a recess provided on the back surface side of the core member. And a cutout portion provided in the barrier layer of the decorative sheet, and a pinhole or slit penetrating the outer skin layer of the decorative sheet.

When the decorative sheet is constituted by interposing a foam layer between the outer skin layer and the barrier layer,
It is preferable that the pinhole or slit is extended to the foam layer and the cutout portion is formed as a recess that is recessed to the foam layer.

[0010]

In the airbag cover according to the present invention, the portion to be ruptured provided on the decorative sheet is composed of the pinhole or slit of the outer skin layer and the cutout portion obtained by cutting off the barrier layer. Since the outer skin layer need only be provided with pinholes or slits so as to penetrate therethrough without forming recesses, the intended breakage portion can be easily formed without controlling the wall thickness. Also,
When processing the cut portion of the barrier layer, even if the back surface side of the outer skin layer is to be recessed to reduce the wall thickness, it is enough to secure the wall thickness of the outer skin layer above a predetermined level. This is much simpler than the thickness control for ensuring the thickness within a certain range when a concave portion is provided as a breakable portion of the skin layer to deal with it.

The pinholes or slits provided in the outer skin layer may be formed in the outer skin layer in advance before injection molding of the core material that integrates the decorative sheet and the core material. May be formed by injection-molding to be integrated with the decorative sheet. Further, the cutout portion provided in the barrier layer may be formed in the barrier layer in advance before injection molding of the core material that integrates the decorative sheet and the core material, or the core material may be injection molded. When forming the concave portion of the core material after being integrated with the decorative sheet, the barrier layer may be processed by using a processing jig for forming the concave portion.

Therefore, the airbag cover according to the present invention can easily form the breakable portion even on the decorative sheet provided with the outer skin layer and disposed on the surface of the core material, and smoothly when the airbag is inflated. The airbag can be projected by being broken.

When the decorative sheet is formed by interposing a foam layer between the outer skin layer and the barrier layer, pinholes or slits are extended to the foam layer, and the cut portion is formed by the foam layer. If it is formed as a recess that is recessed up to
It serves as a buffer for both processes, and it is unlikely that the outer skin layer will be recessed when the excision is processed.

Since the foam layer itself is easy to break, the presence or absence of pinholes, slits or recesses does not affect the break of the decorative sheet.

[0015]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the airbag cover 10 of the first embodiment is formed as a part of an instrument panel (hereinafter abbreviated as instrument panel) 8 of an automobile, and the instrument panel 8 is a instrument panel main body 9 And the airbag cover 10.

The instrument panel body 9 comprises a base material 9a made of a hard synthetic resin such as polypropylene containing a filler,
A decorative sheet 12 described later is provided to extend and a decorative sheet 9b arranged to cover the base material 9a.

The airbag cover 10 is arranged at a position to cover the folded airbag 2 of the airbag device 1, and comprises a core material 11 and a decorative sheet 12 arranged on the front surface side of the core material 11. It is configured.

The airbag device 1 will be described. The airbag device 1 includes a bag-shaped airbag 2 that is folded and stored, and a cylinder type inflator 3 that supplies inflation gas to the airbag 2. , A cylindrical diffuser 4 for diffusing gas from the inflator 3 and flowing into the airbag 2, and a box-shaped case 5 covering the airbag 2, the inflator 3, and the diffuser 4 There is.

Reference numeral 4a is a gas flow hole for diffusing the gas from the inflator 3 into the airbag 2 and inflowing it. Reference numeral 4b is a plurality of bolts projecting from the diffuser 4. These bolts 4b are By fixing the nut 6, the case 5, the airbag 2, and the diffuser 4 are integrated, and the airbag device 1 is attached and fixed to the bracket 7 protruding from the frame of the vehicle.

The side wall of the case 5 has a double structure including an inner panel 5a and an outer panel 5b. The outer panel 5b has a predetermined number of claws 5c that are cut and raised and extend toward the inner panel 5a. Are formed. These claws 5c lock a bracket 11a described later.

The airbag cover 10 is constructed so that the breakable portion 16 is arranged in an "H" shape when viewed from above so that the two door portions 17 and 18 can be opened when the airbag 2 is inflated. There is. It should be noted that the position between the upper and lower ends of the “H” shape of the scheduled breakage portion 16 becomes the hinge portion 19 as the center of rotation when the door portions 17 and 18 are opened.

The core material 11 is a thermoplastic elastomer having compatibility with the base material 9a in order to secure the bending property of the hinge portion 19 without breaking and to secure the bonding force with the base material 9a. Are formed from. In the case of the examples, the base material 9a is formed of polypropylene containing a filler, and examples of the thermoplastic elastomer having compatibility with polypropylene include olefin-based thermoplastic elastomer and styrene-based thermoplastic elastomer. In the case of the examples, the core material 11 is formed of an olefinic thermoplastic elastomer.

Further, the core material 11 has
A bracket 11a having a rectangular tube shape is provided so as to project, and a mounting hole 11b for inserting and locking the claw 5c of the case 5 of the airbag device 1 is formed in the bracket 11a. The bracket 11a includes the planned breakage portion 16 and the door portions 17 and 18,
It is formed to connect the portion of the airbag cover 10 to the case 5 of the airbag device 1 so as to be arranged accurately above the folded airbag 2.

The decorative sheet 12 has a skin layer 13 on the front side.
And a barrier layer 14 disposed on the back surface side for protecting the outer skin layer 13 during injection molding of the core material 11, and a foam layer 15 interposed between the outer skin layer 13 and the barrier layer 14. It is configured. The barrier layer 14 also serves to protect the foam layer 15 when the core material 11 is molded.

In the case of the embodiment, the outer skin layer 13 is formed of soft vinyl chloride, the barrier layer 14 is formed of the same olefinic thermoplastic elastomer as the core material 11, and the foam layer 15 is formed of expanded polypropylene. There is. The outer skin layer 13 has a wall thickness of 0.7 mm, the barrier layer 14 has a wall thickness of 1.0 mm, and the foam layer 15 has a wall thickness of 3.0 mm.

A recess 16a is formed in the core material 11 at the site of the breakable portion 16, and the cut portion 1 is formed in the barrier layer 14.
6b is formed, and the outer skin layer 13 is provided with a large number of pinholes or slits 16c arranged along the breakable portion 16. The cutout portion 16b is a recessed portion 16d in which the recessed portion 16a of the core material 11 is extended to the site of the foam layer 15.
It is formed as a part of.

The recesses 16a and 16d are the portions to be broken 1
It may be formed continuously or intermittently along the “H” of 6.

The inner diameter of the pinhole 16c is preferably 0.1 to 0.5 mm (0.3 mm in the embodiment). If the inner diameter is less than 0.1 mm, the breaking strength increases,
This is because there is a disadvantage that the deployment performance is deteriorated, and when the inner diameter exceeds 0.5 mm, there is a disadvantage that the appearance is deteriorated.

In the pinhole 16c, the interval formed along the "H" shape of the breakable portion 16 is 1 to 4 mm.
(2 mm pitch in the embodiment) is preferable. This is because if the distance is less than 1 mm, the durability cannot be ensured such as breakage during normal use, and if it exceeds 4 mm, the breaking strength becomes large and the deployment performance deteriorates.

When the slit 16c is formed in the outer skin layer 13, it is preferable that the width thereof be almost 0 mm and the length of one slit 16c be 0.5 to 3.0 mm.
If it is less than 0.5 mm, the breaking strength becomes large and the developing performance is deteriorated, and if it exceeds 3.0 mm, the avoidance of the slit 16c appears in the appearance during normal use. Further, the interval between the slits 16c is preferably 5 to 8 mm. If it is less than 5 mm, there is a problem that durability such as breakage during normal use cannot be ensured, and if it exceeds 8 mm, breaking strength becomes large and deployment performance is deteriorated.

The airbag cover 10 and the instrument panel 8
First, the sheet-shaped decorative sheet 12 including the portion of the decorative sheet 9b is vacuum-formed into a predetermined shape to be embedded in the instrument panel 8, and then, as shown in the upper stage of FIG. , A large number of pins P on the decorative sheet 12
To form the pinhole 16c or use the cutter P having a small thickness to form the slit 16c.

Then, the decorative sheet 1 in which a molding die for injection molding the base material 9a of the instrument panel body 9 is formed into a predetermined shape.
2. 9 is set and the base material 9a is formed.

After that, the core material 11 of the airbag cover 10
Set it in the injection mold of and, as shown in the middle of Fig. 4,
The core material 11 is formed.

After releasing the mold, as shown in the lower part of FIG. 4, the recess 1 is formed by using the processing horn H of the ultrasonic welder.
The instrument panel 8 can be manufactured by forming 6 a and 16 d and further forming the mounting hole 11 b in the bracket 11 a of the core material 11.

Since the base material 9a, the core material 11, and the barrier layers 14 of the decorative sheets 9 and 12 have the same kind or compatibility with each other, they are strong without using an adhesive agent separately. Will be joined to.

When forming the recesses 16a and 16d, in addition to using an ultrasonic welder, a heated cutter or a cutter using high frequency is used.
16d may be formed.

After the instrument panel 8 is manufactured, when the instrument panel 8 is mounted on the vehicle and then connected to the airbag apparatus 1, the inner panel 5a in the case 5 of the airbag apparatus 1 integrated by using the bolts 4b is integrated. The bracket 11a is inserted between the outer panel 5b and each of the claws 5c to be inserted and locked in the mounting hole 11b, and the airbag device 1 is attached to the instrument panel 8.
When the bracket 7 is fixed to the bolts 4b by the nut 6 and the other end of the bracket 7 is fixed to a frame (not shown), the airbag device 1 can be attached to the vehicle by connecting to the instrument panel 8. . It should be noted that when the instrument panel 8 is mounted on the vehicle, a predetermined instrument or the like is provided.

When the gas from the inflator 3 is discharged at a predetermined time, the gas is flown into the airbag 2 through the gas circulation hole 4a of the diffuser 4, and the airbag 2 is broken at a portion 16 to be broken. Let the hinge part 19
The door parts 17 and 18 are opened with the center of rotation as the center of rotation, and the door parts 17 and 18 largely project from the instrument panel 8.

As described above, in the airbag cover 10 according to the first embodiment, the breakable portion 16 provided on the decorative sheet 12 has the pinhole or the slit 16c of the outer skin layer 13.
And a cut-off portion 16b obtained by cutting the barrier layer 14, and the outer skin layer 13 does not need to be provided with a recessed portion but only needs to be provided with a pinhole or slit 16c so as to penetrate therethrough. Therefore, the planned breakage portion 16 can be easily formed without performing the thickness control.
When the airbag 2 is inflated, the airbag 2 can be smoothly broken and the airbag 2 can be projected.

Further, in the airbag cover 10 of the embodiment, the decorative sheet 12 is constituted by interposing the foam layer 15 between the outer skin layer 13 and the barrier layer 14, and foams the pinhole or slit 16c. If the cutout portion 16b is extended to the layer 15 and the cutout portion 16b is formed as a recessed portion 16d that is recessed into the foam layer 15, the foamed layer 15 serves as a buffer portion for processing both of them, and the outer skin layer 13 may be recessed during the cutout portion 16b. It does not occur either.

Incidentally, the airbag cover 10 of the first embodiment.
Then, the decorative sheet 12 includes the outer skin layer 13, the barrier layer 14,
Also, a three-layer structure having the foam layer 15 is shown.
You may make it use the decorative sheet of the two-layer structure which does not have the foam layer 15. In this case, when the cutout portion 16b of the barrier layer 14 as shown in the lower part of FIG. 4 is processed, even if the back surface side of the outer skin layer 13 is recessed to reduce the wall thickness, the outer skin layer 13 is formed. Since it suffices to perform processing to secure a predetermined thickness or more, it is significantly simpler than the thickness management that secures a thickness within a certain range when a concave portion is provided as a planned breakage portion of the outer skin layer 13 to deal with it. As a result, it is possible to easily form the breakable portion in the airbag cover.

Further, the airbag cover 10 of the first embodiment.
Then, in the case where the core member 11 is provided with the bracket 11a that is connected to the case 5 of the airbag device 1 in order to properly dispose the planned breakage portion 16 and the door portions 17 and 18 above the folded airbag 2. However, if the airbag cover 10 is disposed above the airbag 2 with high accuracy, like the airbag cover 20 of the second embodiment shown in FIG. 5,
It is not necessary to provide a bracket for connecting to the case 5.

Further, the airbag cover 10 of the first embodiment.
Then, a pinhole or slit 16 provided in the outer skin layer 13
Although c is shown in the case of being formed on the outer skin layer 13 in advance before the injection molding of the core material 11 in which the decorative sheet 12 and the core material 11 are integrated, it is shown that after the core material 11 is formed ( Recess 16a
May be formed before or after forming), and a pinhole or a slit 16c may be formed in the outer skin layer 13.

Further, the airbag cover 1 of the first embodiment.
At 0, the cutout portion 16b provided in the barrier layer 14 is replaced with
After injection molding 1 to make it integral with the decorative sheet 12,
The case where the concave portion 16a of the core material 11 is formed at the same time by using the processing jig H is shown.
Before the injection molding of the core material 11 in which the core material 11 and the core material 11 are integrated,
The cutout portion 16b may be formed in the barrier layer 14 of the decorative sheet 12 in advance. In that case, the decorative sheet 12
After shaping into a predetermined shape, pinhole or slit 1
6c and the cutout portion 16b are provided, and after that, the core material 11 is molded and the recessed portion 16a is formed in the core material 11, so that the planned breakage portion is the same as the airbag cover 30 of the third embodiment shown in FIG. Reference numeral 16 includes a recess 16a provided in the core material 11, a recess 16d recessed to the foam layer 15 including the cutout portion 16b of the barrier layer 14 in the decorative sheet 12, and a pinhole or slit 16c in the outer skin layer 13. Will be done. By the way, when the core material 11 is molded after the cutout portion 16b is provided in the barrier layer 14, the foam layer 15 and the outer skin layer 13 may be damaged by heat or injection pressure during molding of the core material 11. However, since the cutout portion 16b has a narrow width (0.5 mm or less), the foam layer 15 and the outer skin layer 13 are not damaged to such an extent that the outer surface of the decorative sheet 12 is affected. .

The concave portion 16a provided in the core material 11 is formed by a cutter or the like after the core material 11 is formed by injection molding, and the core material 11 is formed by a mold surface during injection molding of the core material 11.
It may be formed at the same time as the molding.

Furthermore, in the airbag covers 10, 20 and 30 of the respective embodiments, the pinhole or slit 16c is formed.
Although the case of penetrating to the portion of the recess 16d provided in the foam layer 15 is shown, a pin extending halfway through the foam layer 15 as in the airbag cover 40 of the fourth embodiment shown in FIG. It may be a hole or a slit 16c. By the way, since the foam layer 15 itself easily breaks, the breakage of the decorative sheet 12 is not affected by the presence or absence of the pinholes or the slits 16c or the recesses 16d. When the pinholes or slits 16c are formed so as to penetrate the decoration sheet 12 as shown in the upper part of FIG. 4, the foam layer 15 of the decoration sheet 12 is different from the airbag cover 40 of FIG. Since it is not necessary to stop the movement of the pin or the cutter P in the middle of the part, the pinhole or the slit 16c can be easily processed.

Further, in each of the embodiments, the airbag cover 10, 20, 30, 40 used for the instrument panel 8 is shown, but it is arranged so as to cover the airbag of the airbag device other than the instrument panel. The present invention can be applied to door trims, seat backs, steering wheel pads, and the like.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view showing a main part of a first embodiment of the present invention.

FIG. 2 is a perspective view of the embodiment.

FIG. 3 is a sectional view showing a mode of use of the embodiment.

FIG. 4 is a diagram showing a process of processing a to-be-broken part of the embodiment.

FIG. 5 is a cross-sectional view showing a mode of use of the second embodiment.

FIG. 6 is an enlarged sectional view of a third embodiment.

FIG. 7 is an enlarged sectional view of a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Airbag device, 2 ... Airbag, 10/20/30/40 ... Airbag cover, 11 ... Core material, 12 ... Decorative sheet, 13 ... Outer skin layer, 14 ... Barrier layer, 15 ... Foam layer, 16 ... Expected breakage portion, 16a ... Recessed portion, 16b ... Cutout portion, 16c ... Pinhole / slit.

Claims (2)

[Claims] 1. A core material and a decoration sheet arranged on the front surface side of the core material, wherein the decoration sheet is provided on an outer skin layer on the front surface side of the decoration sheet and on a back surface side of the decoration sheet. And a barrier layer for protecting the outer skin layer when the core material is injection-molded, covering the folded airbag and breaking to protrude the airbag when inflated. An airbag cover made of a synthetic resin in which a breakable portion is arranged, wherein the breakable portion is a recessed portion provided on the back surface side of the core member, and a cutout portion provided in the barrier layer of the decorative sheet,
An airbag cover, comprising: a pinhole or a slit penetrating an outer skin layer of the decorative sheet. 2. The decorative sheet is configured by interposing a foam layer between the outer skin layer and the barrier layer, the pinhole or slit is extended to the foam layer, and the cutout portion is The airbag cover according to claim 1, wherein the airbag cover is formed as a recess that is recessed to the foam layer.