JP2006290305A - Interior panel for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interior panel for an automobile furnished with a skin and a cushion layer having soft feeling not requiring perforation work, good in tactile impression and in outer appearance, integrating an airbag device inside, capable of certainly rupturing along a predetermined rupturing line in actuation of the airbag device and high in reliability as a safety device. <P>SOLUTION: This interior panel with the stored airbag built therein has a hard resin made base material layer arranged on the side of the airbag device, a cushion layer stacked on the base material layer and the soft polyurethane resin made skin stacked on the cushion layer, a weak part is formed on the side facing the airbag device as a predetermined rupturing part of the skin and a slope part to gradually reduce height along the weak part and toward a weak part peripheral edge is characteristically provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automobile interior panel having an airbag device mounted therein.

The airbag device senses an impact when the automobile receives an impact, inflates and deploys the airbag, and interposes between the vehicle body and the occupant, thereby protecting the occupant.
In recent years, it has spread rapidly, not only the steering wheel for the driver's seat and the instrument panel for the passenger's seat, but also the side airbag on the side of the vehicle body that protects the passengers from the impact on the side. It came to be established.
Among these, in the airbag device for the passenger seat disposed at the lower part of the instrument panel, an airbag cover for covering the airbag device is prepared separately from the instrument panel, and this is provided on the instrument panel. In recent years, there has been a desire to streamline manufacturing and assembly operations by integrating them into modules, and to improve the appearance of instrument panels as interior parts. Has been.

And what has integrated the airbag cover body in the instrument panel in this way has already been proposed, for example, the thing of Unexamined-Japanese-Patent No. 11-291069 (patent document 1) is an instrument panel. In this method, injection molding is performed without providing an opening, and laser processing is performed at a position corresponding to the airbag storage position on the back surface of the panel to form a planned fracture line.
In addition, there has also been proposed a molding method in which a planned fracture line is formed at the time of molding without post-processing the planned fracture line for deploying the airbag cover body after panel formation (Japanese Patent Laid-Open No. 2002-2002). No. 234413, Patent Document 2).
Furthermore, when a planned fracture line is machined into a hard instrument panel made of a hard material, a block with needle pins is advanced and retracted into the cavity for the machining, and on the opposite side of the block temperature of the fractured line machining surface. A molding method has also been proposed in which the mold temperature is raised to prevent the block pressing trace from appearing on the surface (Japanese Patent Laid-Open No. 2003-146171, Patent Document 3).

However, the former method of post-processing the expected fracture line requires a laser processing machine for this purpose, and also has a problem from the viewpoint of productivity, such as requiring subtle processing operations after molding. .
In addition, the latter molding method is a rational method in that no post-processing is required, but it is necessary to provide a core for forming a planned fracture line in the molding die so that it can be moved forward and backward. It becomes complicated and the molding method becomes complicated.

In addition, since the instrument panel is an interior part, its appearance and touch are also important. For this reason, various types have been proposed in which the surface layer of the panel is made of a soft and soft material and is laminated on the base material layer. In addition, a method has been proposed in which the surface layer is used as a skin layer, a foam layer, and a barrier layer, and this is inserted to insert a base material layer (Japanese Patent Laid-Open No. 2000-16216, patent) Reference 4).
The planned rupture portion is constituted by a cut portion extending from the surface side of the base material layer to the barrier layer of the epidermis, and a corresponding portion of the skin layer is provided with a hole capable of breaking the skin layer.
JP-A-11-291069 JP 2002-234413 A JP 2003-146171 A JP 2000-16216 A

In an airbag cover integrated with an automobile interior member such as an instrument panel, its appearance and feel are important.
Therefore, it is desirable that the airbag cover has a structure having a cushion layer. However, in the airbag cover having a skin with a cushion layer, in order to make the break smooth, the skin side also needs to be drilled as shown above after molding the skin in the position corresponding to the planned fracture portion, as described above. In addition to having a problem with the properties, the presence of pores in the epidermis is a problem in appearance even though they are minute holes.

  Under such circumstances, the present invention is an automotive interior panel in which an air bag device is integrated therein, which is excellent in tactile sensation and appearance with a soft skin and cushion layer that do not require hole processing, In addition, an object of the present invention is to provide an automobile interior panel that can be reliably broken along a planned break line when the airbag device is operated and has high reliability as a safety device.

  As a result of diligent study, the present inventors firstly formed the above-described object by forming a raised portion having a predetermined shape on the cushion layer side of the soft skin so that the panel is smoothly broken when the airbag is operated. As a result, the present invention has been found.

That is, the present invention
(1) An interior for an automobile in which a portion to be broken that covers the airbag inflating direction of an airbag device incorporating a stored airbag and forms a door portion by deployment of the airbag is formed on the side facing the airbag device. A panel,
A hard resin base material layer disposed on the airbag device side, a cushion layer laminated on the base material layer, and a soft polyurethane resin skin further laminated on the cushion layer;
The skin is provided with a weak portion that constitutes the planned fracture portion,
A raised portion is formed along at least one side of the edge of the weak portion, and the raised portion has a slope portion that gradually decreases in height toward the outside of the weak portion with the upper edge side of the side wall of the weak portion as the highest point. An automotive interior panel characterized by having,
(2) The interior of an automobile according to (1), wherein the weak part has a bent part that bends in one direction from one direction, and the raised part is formed at least on the outer periphery side of the bent part. panel,
About.

According to the present invention, in the interior panel for automobiles in which the airbag device is integrated therein, as the skin, a skin made of soft polyurethane that is not hole-processed after molding is provided, and a cushion layer is provided in the lower part thereof. A panel with excellent appearance and tactile sensation, and when the airbag device is activated, a weak portion formed on the side of the airbag device and a slope portion that gradually reduces the height toward the outside of the weak portion. Therefore, the airbag can be smoothly broken as expected along the site without breaking beyond the planned site of breakage when the airbag is operated, and a highly reliable automobile interior panel can be obtained.
In addition, when the cushion layer extends inside the weak part of the skin, the weak surface provided on the skin does not affect the panel surface visually. Therefore, it is possible to obtain an excellent surface appearance that is completely compatible with the general part of the interior panel both in terms of feeling and visual.
Further, even in a panel with a cushion layer interposed, a weak portion is formed by a raised portion formed so as to have a slope portion that gradually decreases in height toward the outside of the weak portion with the upper edge side of the side wall of the weak portion as the highest point. In addition, the breaking stress is stably applied, and the breaking is not propagated off the weak part. Furthermore, the surface appearance is also limited to a gradual change in the thickness in the vicinity of the weak part and the peripheral part, and the occurrence of poor appearance during molding can be suppressed.

As described above, the automobile interior panel of the present invention includes the base material layer, the cushion layer laminated thereon, and the skin laminated thereon.
The base material layer preferably has a thickness of 2.5 to 4.0 mm, and is preferably formed by an injection molding method from a relatively hard material, for example, PPC resin in which polypropylene is reinforced with talc or the like. The hard material can be appropriately selected from resins such as a composite resin (polymer alloy) of polycarbonate and ABS resin, maleimide resin (SMA), and modified polyphenylene oxide (mPPO). Moreover, the cushion layer laminated | stacked on it becomes like this. Preferably it is 5-8 mm in thickness, and it is preferable to shape | mold by a reaction injection molding method using a foaming material, for example, a polyurethane foam.
Furthermore, the skin layered thereon is made of a soft polyurethane material having good tactile sensation, the thickness is 0.5 to 1.0 mm in the general part, and the thickness in the first weak part is 1.0 to 2 0.5 mm, preferably about 1.5 mm, the groove width is 1.0 to 2.5 mm, preferably about 2.0 mm, the thickness at the second weak part is about 0.2 mm to 0.5 mm, and the width or diameter is 0. It is preferable to use a long groove and / or a plurality of holes of about 7 to 2.5 mm, preferably about 1.0 mm. Further, the raised portion provided in a more preferred embodiment of the present invention preferably has a height from the general portion of 1.0 to 3.0 mm, more preferably about 2.0 mm, and the top width is 2. 5 mm to 6.0 mm is preferable. The skin is thin in this way, and in particular, it has a very thin structure at the site where it is expected to break. Therefore, the polyurethane resin material is preferably a low-viscosity material with high fluidity and a small shrinkage after molding. Is preferred. And it is preferable to shape | mold by such an injection molding or reaction injection molding method using such a material. The cushion layer is formed by inserting the base material layer and the skin into the mold and injecting them between them, and filling the inside of the concave portion of the skin, and the cushion layer extends there It is also preferred that As a result, the skin appearance can be prevented from being affected by the recess.

Moreover, in the site | part which a fracture | rupture planned part cross | intersects, in order to make it fracture | rupture smoothly, it is preferable that a 2nd weak part is continuously formed in a cross | intersection site | part (bending part).
In the present invention, in order to further ensure smooth rupture, a raised portion is provided at the bent portion of the weak portion, and the soft, thin, low-strength skin exceeds the weak portion constituting the planned rupture line. It is preferable to further wipe away the fear of breaking to the area outside the planned portion. Therefore, the bulge may be provided on one side or both sides along all of the weak parts of the epidermis, but the region where the unscheduled shift may occur more at the rupture site, for example, the planned rupture line intersects. It is good to provide intensively on the crossing outer periphery side of a part (bending part).
By adopting such a structure for the portion to be ruptured, a panel having a three-layer structure including a cushion layer in the intermediate layer and a thin and low-strength skin can be viewed from below when the airbag device is operated. By pushing up the airbag to be inflated, the airbag does not break beyond the planned break portion, and the airbag can be smoothly deployed.
The raised portion can also contribute to improving the surface appearance of the epidermis. That is, as a result of preventing the shift to the unexpected region at the time of breakage, the general portion other than the concave portion can be made thinner, and thereby the appearance and touch can be finished to a softer feeling.
This weak portion can be provided in a U-shape in the case of a single door, or in an H shape in the case of a double door, according to the shape of the door portion of the airbag cover.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of an upper panel for an instrument panel, which is an automobile interior panel in which an airbag device is integrated. FIG. 2 is an explanatory view of the back surface of the panel shown in FIG. FIG. 3 illustrates the structure of the back surface of the skin layer of the panel of FIG. 1, which is intended for a double door (left side in FIG. 3) and a single door (right side in FIG. 3) for deploying an airbag, respectively. It is. 4 is a sectional view taken along line AA in FIG. 2, and FIG. 5 is a sectional view taken along line BB in FIG. FIG. 6 is a plan view for explaining a concave portion (a weak portion to be broken) provided on the back surface of the skin, and FIG. 7 is a cross-sectional explanatory view taken along the line XX in FIG. Further, FIG. 8 is an explanatory view showing a modification at the position corresponding to FIG.

  In these drawings, 1 is an automotive interior panel body, 2 is a soft resin inner member (a support member for a door part), 3 is a door part, 4 is a door reinforcing part, 5 is a hinge part, and 6 is a skin rupture line. 7 is a gap portion, 8 is a thin hinge portion, 9 is a weak portion of the base material layer, 10 is a joint portion, 11 is a retainer fixing hole, 12 is an outer peripheral edge portion, 13 is a soft polyurethane skin, and 14 is a hard resin base material layer , 15 is a cushion layer, 16 is a discontinuous recess, 17 is a continuous recess, and 18 is a raised portion.

In this embodiment, the concave portion is provided as a hole in the entire region that is a planned fracture line. However, continuous grooves were formed at the portions where the planned fracture lines intersect. The holes were 0.5 mmφ and the distance between the holes was 0.3 mm.
In the manufacture of the panel shown in FIG. 1, first, the skin is formed by an injection molding or reaction injection molding method using a mold corresponding to the structure of the planned fracture portion.
As the polyurethane material, since the skin of the present invention has a very thin portion, it is preferable to use a polyurethane material having high fluidity, for example, a viscosity of 500 to 1000 centipoise in filling. Further, a molding material having a shrinkage rate after molding as small as possible, for example, about 3 to 1 / 10,000 is preferable. For smooth cleavage, the skin preferably has a specific gravity of 0.8 or more, non-foaming or fine foaming, and a tensile load of 70 kgf / cm or less.

As described above, the base material layer is manufactured by injection molding from, for example, polypropylene filled with talc. The weak part of a base material layer may be provided at the time of the shaping | molding, and the part concerned may be excised after shaping | molding. Next, the skin and the base material layer are inserted into a mold, and a polyurethane foam material is filled between the members by a reaction injection molding method to form the automobile interior panel shown in FIG.
In addition, the soft inner member which accommodates an airbag apparatus shown in FIG. 1 is joined with the panel main body by vibration welding in the door reinforcement part and the outer periphery part by the welding rib.

  FIG. 9 is a single perspective view of a panel skin 20 that adopts a structure to be broken similar to the structure of FIG. 8 and shows a cross-sectional shape of the part to be broken with a part cut away. The panel skin 20 is made of polyurethane resin by an injection reaction molding method. The general skin portion 21 has a thickness of 1.0 mm, and the to-be-broken portion 22 having a substantially H shape has a cylindrical shape with a diameter of 1.0 mmφ at the bottom of the groove portion 23. A large number of holes 24 are formed and formed. There is a continuous groove 27 in the array of holes 24. When the continuous groove 27 is disposed at a bending point (intersection) 39 of the planned fracture portion, it is a continuous groove 27a having a substantially T-shape in a plane, and an I-shaped continuous groove 27b in the middle portion.

  FIG. 10 shows a cross-section of the Y part in FIG. Although the thickness of the bottom part of the hole 24 is 0.5 mm, the bottom part is in a range of 0.3 mm to 0.8 mm, etc., and the bottom part is a small L-shaped end part 22d, etc. You may make it change the thickness of. In the example shown in the figure, the thickness of the bottom of the H-shaped central transverse portion 22c and the side portions 22a and 22b is 0.5 mm, and the end portion 22d is 0.7 mm.

  The raised portion 30 forms a flat portion 25 with a width of, for example, 4.0 mm in the horizontal direction from the upper edge portion 28 a of the side wall 28 of the groove portion 23, and a slope portion 26 that gradually decreases in height toward the general skin portion 21 therefrom. Forming. Although the length of the slope of this slope part 26 can be selected suitably, it shall be about 15 mm, for example. That is, the thickness of the flat portion 25 is 3.0 mm, and the slope portion 26 from the end of the flat portion is gently connected with a height difference of 2.0 mm from the general skin portion 21 by an oblique side length of 15 mm.

  Since it did in this way, it becomes difficult for the modeling of the back surface side to appear on the surface appearance, and the position and shape of the planned fracture portion itself are regulated by the mold at the time of molding due to the uneven shape of the mold for molding the groove 23 and the hole 24. However, since the position and shape of the regulation from the flat part 25 to the slope part 26 are gentler than the part to be ruptured, the molding distortion of the part to be rupture is alleviated and taken out from the mold (mold release, mold release). It will be easier. Therefore, the subsequent transfer to the molding process of the cushion layer is facilitated, making it possible to greatly contribute to realizing high-quality appearance as a whole at the mass production level, improving productivity and yield, and reducing manufacturing costs.

  The set portion of the bulge 30 extends over the entire length of the planned fracture portion 22, but at least at the location of the bending point 39, particularly at the outer peripheral side of the turn of the bending point 39, the desired rupture can be stably achieved. It is preferable in generating. Further, the flat portion 25 is high at the bending point 39 and the vicinity thereof, and is gradually lowered at other portions, or the flat portion 25 is widened at the bending point 39 and the vicinity thereof, and is appropriately narrowed at other portions or zero. You can also do it.

The perspective view of the interior panel for motor vehicles which integrated the airbag apparatus of this invention. Explanatory drawing of the back surface of FIG. The back surface explanatory drawing of the skin in the interior panel for motor vehicles of this invention. FIG. 2A-A sectional explanatory drawing. FIG. 2B-B line sectional explanatory drawing. The top view explaining the recessed part (fracture plan weak part) provided in the back surface of an outer skin. Cross-sectional explanatory drawing in the XX line site | part in FIG. Explanatory drawing which shows the modification in the position corresponding to FIG. The single-piece | unit perspective view of the outer skin in the interior panel for motor vehicles of this invention. Cross-sectional explanatory drawing in the YY line | wire site | part of FIG.

Claims (2)

An automotive interior panel in which a planned breakage portion that covers the airbag inflating direction of an airbag device incorporating a stored airbag and forms a door portion by deployment of the airbag is formed on the side facing the airbag device. ,
A hard resin base material layer disposed on the airbag device side, a cushion layer laminated on the base material layer, and a soft polyurethane resin skin further laminated on the cushion layer;
The skin is provided with a weak portion that constitutes the planned fracture portion,
A raised portion is formed along at least one side of the edge of the weak portion, and the raised portion has a slope portion that gradually decreases in height toward the outside of the weak portion with the upper edge side of the side wall of the weak portion as the highest point. An automotive interior panel characterized by comprising: 2. The automobile interior panel according to claim 1, wherein the weak part has a bent part that is bent in one direction from one direction, and the raised part is formed at least on the outer periphery side of the bent part.

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