JP3910412B2

JP3910412B2 - Automotive airbag door and method of manufacturing the same

Info

Publication number: JP3910412B2
Application number: JP2001347484A
Authority: JP
Inventors: 幸男大保
Original assignee: Kanto Auto Works Ltd
Current assignee: Toyota Motor East Japan Inc
Priority date: 2001-11-13
Filing date: 2001-11-13
Publication date: 2007-04-25
Anticipated expiration: 2021-11-13
Also published as: JP2003146173A

Description

【０００１】
【発明の属する技術分野】
本発明は、裏面に発泡層が形成されている発泡層付表皮に、合成樹脂製の基材として硬質層が反応射出成形により一体成形されるインストルメントパネルに対して、ドア領域に、硬質層に代えてこの硬質層よりも剛性の低い軟質層が反応射出成形により一体成形されると共に、インストルメントパネル内に収納されたエアバッグの作動により破断開放させるドアを形成するように、このドア形状に対応した破断路が、軟質層に形成されている自動車のエアバッグドア及びその製造方法に関するものである。
【０００２】
【従来の技術】
この種のエアバッグドア２は、インストルメントパネル１に、助手席側の内部にエアバッグを収納するように一体成形されている（図４参照）。また、エアバッグの作動によりエアバッグドア２が破断開放する際に、樹脂部材の飛散を防止するためには、図６に示すように、インストルメントパネル１の発泡層４ａ付表皮４の裏面に、硬質発泡ウレタン製の基材用硬質層５が接合すると共に、ドア領域には、硬質層５に代えて、この硬質層よりも剛性の低い軟質ウレタン製の軟質層６を接合する対策がある。この軟質層には、例えばエアバッグ本体９の取付け用スタッドボルト３ａ付のプレート状リテ−ナ３がインサート成形され、Ｈ形の破断路８が形成される。これにより、エアバッグの作動時に、両側のリテーナ３が端部のスタッドボルト３ａの位置近辺を支点として破断路８に沿って両開きし、その際この破断路の周辺部分は、軟質であることにより飛散するのが回避される。
【０００３】
【発明が解決しようとする課題】
しかしながら、この種の成形では、図７に示すように、表皮４の発泡層４ａに対して硬質層５の領域では特に発泡成形時に相対的に大きな成形圧が加わり（同図Ａ）、したがって軟質層６との境界領域では金型２０からの脱型後に発泡層４ａの圧縮度合の相違に起因してスプリングバック量に差が生じる（同図Ｂ）。つまり、境界領域にドア領域側が凹状になって段差を生じる問題がある。
【０００４】
本発明は、このような点に鑑みて、反応射出成形時に硬質層及び軟質層間の境界領域に段差を生じさせない冒頭に述べた類の自動車のエアバッグ及びその製造方法を提供することを目的とする。
【０００５】
【課題を解決するための手段】
本発明は、この目的を達成するために、裏面に発泡層が形成されている発泡層付表皮に、基材として合成樹脂製の硬質層が反応射出成形により一体成形されるインストルメントパネルに対して、ドア領域に、硬質層に代えてこの硬質層よりも剛性の低い軟質層が反応射出成形により一体成形されると共に、インストルメントパネル内に収納されたエアバッグの作動により破断開放させるドア本体を形成するように、その形状に対応した破断路が、軟質層に形成されている自動車のエアバッグドアにおいて、ドア本体の周辺領域に、軟質層（６）の裏面に硬質層（５）を重ねる境界領域を形成すると共に、この境界領域の軟質層（６）に、境界領域の外周から内周に向けて徐々に肉厚になる傾斜肉薄部分（６Ａ）及びその内周側に続く均一厚みの平行肉薄部分（６Ｂ）を有する肉薄部（６ａ）を形成し、この肉薄部の裏面に重なる硬質層（５）をラップ代（５ａ）として形成し、軟質層（６）にエアバッグ本体を保持するプレート状リテーナ（１０）がインサート成形されると共に、このプレート状リテーナの端部（１０ａ）が、平行肉薄部分（６Ｂ）及びラップ代（５ａ）間に介在し、また端部（１０ａ）の終端に、ラップ代（５ａ）に侵入するように裏側に向けて曲げられた孔（１１ａ）付フランジ部（１１）が形成されていることを特徴とする。
【０００６】
これにより、成形圧が異なる軟質層（６）と硬質層（５）との境界領域において、軟質層（６）の徐々に薄くなる肉薄部（６ａ）にラップ代が重なり、脱型時に発泡層のスプリングバック量の段階的な相違が抑制される。軟質層（６）にインサート成形されるプレート状リテーナ（１０）の端部（１０ａ）が平行肉薄部分（６Ｂ）及びラップ代（５ａ）間に介在することにより、リテーナ（１０）が確実に保持され、また軟質のドア領域も硬質層（５）に確実に保持され、さらに孔（１１ａ）付フランジ部（１１）が硬質層（５）インサート成形されることにより、その樹脂が孔（１１ａ）に侵入して保持が一層確実になる。このようなエアバッグドアの製造方法としては、請求項２により、反応射出成形用の金型（２０）の一方に進退可能に支持されたスライドコア（２１）の先端面（２２）に、この先端面（２２）の途中位置からスライドコア内周端に向けて後退する傾斜後退面（２２ａ）と、この傾斜後退面からさらにスライドコア内周端まで先端面に平行な平行後退面（２２ｂ）とが形成され、金型（２０）の他方に発泡層付表皮（４）がセットされ、孔（１１ａ）付フランジ部（１１）がスライドコア（２１）に侵入するように平行後退面（２２ｂ）にプレート状リテーナ（１０）がセットされた状態でスライドコア（２１）を前進させて金型（２０）を閉鎖し、この金型が閉鎖された状態で、先端面（２２）の内側領域に反応射出成形により軟質層（６）を成形すると共に、この軟質層にプレート状リテーナ（１０）をインサート成形し、さらに傾斜後退面（２２ａ）で傾斜肉薄部分（６Ａ）を、また平行後退面（２２ｂ）で平行肉薄部分（６Ｂ）を成形し、スライドコア（２１）を後退させて、軟質層（６）の周囲に反応射出成形により硬質層（５）を成形すると共に、この硬質層に孔（１１ａ）付フランジ部（１１）をインサート成形することを特徴とする。
【０００７】
【発明の実施の形態】
図１乃至図４を基に本発明の実施の形態による自動車のエアバッグドアを図４に示すエアバッグドアに適用して説明する。このエアバッグドア２は、前述したように、発泡層４ａ付の表皮４の裏面に接合された硬質発泡ウレタン製の基材としての硬質層５におけるエアバッグドア２の領域に相対的に剛性の低いウレタン製の軟質層６が接合されて助手席側のインストルメントパネル１に一体成形されている。
【０００８】
この軟質層にインサート成形されるエアバッグ本体取付け用のスタッドボルト１３付のプレート状のリテ−ナ１０（対応する前述のリテーナ３を参照）の両側の端部１０ａの終端には、裏側に曲げられたフランジ部１１を追加して形成され、成形時に硬質層５の樹脂を染み込ませる孔１１ａが形成されている(図３参照)。
【０００９】
金型２０の上型２０ａには、ドア領域を規定する方形状のスライドコア２１が進退可能に支持されると共に、その先端面２２のスライドコア内周端寄りの途中位置からスライドコア内周端に向けて中間位置まで徐々に後退する傾斜後退面２２ａが形成され、次いでスライドコア内周端まで先端面２２に平行な平行後退面２２ｂが形成されている。さらに、上型２０ａには、実際に両側に開放するドア本体２ａの形状に対応したＨ形の破断路８を形成するための凸部２５(図２参照)が形成されている。
【００１０】
製造に際しては、真空成形、パウダースラッシュ成形等で裏面に発泡層４ａを形成された表皮４を反応射出成形用の金型２０の下型２０ｂにセットする(図１Ａ、図２Ａ)。次いで、リテーナ１０が分離可能にセットされたスライドコア２１を前進させて金型２０を閉じた後に、スライドコア２１の先端面２２の内側領域にウレタン材の反応射出成形により、傾斜後退面２２ａ及び平行後退面２２ｂの形状に対応して軟質層６の裏面に硬質層５が重ねられる境界領域の外周から内周に向けて徐々に肉厚になる傾斜肉薄部分６Ａ及びその外周側に続く均一厚みの平行肉薄部分６Ｂを有する肉薄部６ａを伴う軟質層６を形成する(図１Ｂ、図２Ｂ)。同時にリテ−ナ１０のプレート部分をインサート成形する。続いて、スライドコア２１を後退させて軟質層６の周囲に、硬質層５をウレタン材の反応射出成形により形成し、そのスライドコア２１の形状に対応した方形状の境界領域には肉薄部６ａ並びに裏側では傾斜後退面２２ａ及び平行後退面２２ｂの形状に対応したラップ代５ａが形成される
(図１Ｃ、図２Ｃ)。同時にリテ−ナ１０の端部１０ａが、平行肉薄部分６Ｂ及びラップ代５ａ間に介在した状態で、フランジ部１１を硬質層５にスタッドボルト１３と共にインサート成形する。
【００１１】
このような反応射出成形の際に、硬質層５の特に発泡により相対的に大きな成形圧が生じ、発泡層４ａを相対的に強く圧縮させる。但し、成形圧が小さな軟質層６との境界領域では、その肉薄部６ａの裏側に硬質のラップ代５ａが介在することにより、成形圧の急峻な変化が緩和されて、肉薄部６ａの外周部分が傾斜して徐々に薄くなることにより、成形圧が段階的に変化するのが一層確実に回避される。
【００１２】
脱型により、エアバッグドア２が一体成形されたインストルメントパネル１が製作される(図１Ｄ、図２Ｄ)。その際、発泡層４ａには金型２０による加圧が解除されてスプリングバック現象が生じるが、エアバッグドア２の周辺の境界領域には、成形圧の段階的な変化が抑制されて膨張度の急峻な変化が生じず、表皮４の境界領域に方形状に段差が発生するのが防止される。
【００１３】
ラップ代５ａと肉薄部６ａとの接合領域は、軟質層６の反応射出成形時の離型剤残りによる密着不良の発生が懸念されるが、金型表面をテフロン（登録商標）によるコーティング等により離型剤無しにしなくても、離型剤塗布後にセットされ、かつ接合性の良い鉄製リテーナ１０を介して確実に接合される。また、そのフランジ部１１は、その孔１１ａに硬質層５の樹脂が侵入して、軟質のドア領域は硬質層５に確実に保持され、スタッドボルト１３もラップ代５ａも硬質のラップ代５ａにより確実に保持される。エアバッグの作動時に両側に分離されたリテーナ１０は、スタッドボルト１３の位置近辺を支点として中央の破断路８の位置を開放端としてそのＨ形で規定される軟質層６のドア本体２ａを破断開放させる。
【００１４】
尚、参考例として、プレート状リテーナを備えることなく別のリインフォースがインサート成形される場合にも適用され、このような場合でも、図５に例示するように、ラップ代６ｂを形成することができる。この場合、金型は境界領域同士の接合性を考慮して離型剤レス化にするのが好ましい。
【００１５】
【発明の効果】
請求項１の発明によれば、エアバッグドアが成形圧の異なる軟質層で形成される場合でも周囲の境界領域において軟質層の徐々に外周に向けて薄くなる肉薄部に硬質層のラップ代が重なり、表皮の発泡層に段差が生じず、外観品質を損なうことなく破断開放領域の樹脂部材の飛散が回避される。軟質層にインサート成形されるプレート状リテーナの端部が平行肉薄部分及びラップ代間に介在することにより、リテーナが硬質層に確実に保持され、また軟質のドア領域も硬質層に確実に保持され、さらに孔付フランジ部が硬質層にインサート成形されることにより保持が一層確実になる。
【００１６】
請求項２の発明による製造方法によれば、請求項１の発明によるラップ代がスライドコアを利用して容易に形成されると共に、軟質層にインサート成形されるプレート状リテーナ及び軟質層を硬質層のラップ代に保持させることができる。
【図面の簡単な説明】
【図１】本発明の実施の形態によるエアバッグドアの製造工程の要部を説明する図である。
【図２】同エアバッグドアの製造工程を説明する要部拡大断面図である。
【図３】同エアバッグドアのリテーナの部分斜視図である。
【図４】同エアバッグドアを備えたインストルメントパネルの斜視図である
【図５】本発明の参考例としての硬質層及び軟質層の境界領域を示す断面図である。
【図６】本発明の前提となる構成のエアバックドアの断面図である。
【図７】従来のエアバックドアの反応射出工程の脱型時点の要部断面図である。
【符号の説明】
１インストルメントパネル
２エアバッグドア
４表皮
４ａ発泡層
５硬質層
５ａラップ代
６軟質層
６ａ肉薄部
６Ａ傾斜肉薄部分
６Ｂ平行肉薄部分
８破断路
１０リテ−ナ
１０ａリテ−ナの端部
１１フランジ部
１１ａ孔
２０金型
２０ａ上型
２０ｂ下型
２１スライドコア
２２ａ傾斜後退面
２２ｂ平行後退面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an instrument panel in which a hard layer is integrally formed by reaction injection molding as a synthetic resin base material on a skin with a foam layer having a foam layer formed on the back surface. Instead of this hard layer, a soft layer having a rigidity lower than that of the hard layer is integrally formed by reaction injection molding, and this door shape is formed so as to form a door that is opened by breaking the operation of an airbag stored in the instrument panel. This relates to an automobile airbag door in which a fracture path corresponding to the above is formed in a soft layer and a method for manufacturing the same.
[0002]
[Prior art]
This type of airbag door 2 is integrally formed on the instrument panel 1 so as to accommodate the airbag inside the passenger seat (see FIG. 4). Further, when the airbag door 2 is broken and opened by the operation of the airbag, in order to prevent the resin member from being scattered, as shown in FIG. 6, on the back surface of the skin 4 with the foam layer 4 a of the instrument panel 1. In addition to joining the hard foam base material layer 5 made of hard foamed urethane, there is a measure to join the soft layer 6 made of soft urethane having lower rigidity than the hard layer 5 in the door region instead of the hard layer 5. . In this soft layer, for example, a plate-like retainer 3 with a stud bolt 3a for mounting the airbag main body 9 is insert-molded, and an H-shaped fracture path 8 is formed. Thereby, at the time of the operation of the airbag, the retainers 3 on both sides are opened along the breaking path 8 with the vicinity of the position of the stud bolt 3a at the end as a fulcrum, and the peripheral portion of the breaking path is soft at this time. Spattering is avoided.
[0003]
[Problems to be solved by the invention]
However, in this type of molding, as shown in FIG. 7, a relatively large molding pressure is applied to the foamed layer 4a of the skin 4 in the region of the hard layer 5 particularly in the foam molding (A in FIG. 7). In the boundary region with the layer 6, a difference in the amount of spring back occurs due to the difference in the degree of compression of the foamed layer 4 a after demolding from the mold 20 (B in the figure). That is, there is a problem that the door region side becomes concave in the boundary region and a step is generated.
[0004]
SUMMARY OF THE INVENTION In view of the above, the present invention has an object to provide an automobile airbag of the kind described at the beginning and a method for manufacturing the same that does not cause a step in a boundary region between a hard layer and a soft layer during reaction injection molding. To do.
[0005]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides an instrument panel in which a hard layer made of synthetic resin is integrally formed by reaction injection molding as a base material on a skin with a foam layer formed on the back surface. In the door area, instead of the hard layer, a soft layer having a lower rigidity than the hard layer is integrally formed by reaction injection molding, and the door body is opened by breaking the air bag accommodated in the instrument panel. In the automobile airbag door in which the breakage path corresponding to the shape is formed in the soft layer, the hard layer (5) is formed on the back surface of the soft layer (6) in the peripheral region of the door body. An overlapping boundary region is formed, and the soft layer (6) in this boundary region has an inclined thin portion (6A) that gradually increases in thickness from the outer periphery to the inner periphery of the boundary region, and a uniform thickness that continues to the inner peripheral side. A thin part (6a) having a parallel thin part (6B) is formed, a hard layer (5) overlapping the back surface of this thin part is formed as a wrap margin (5a), and the airbag body is held by the soft layer (6) The plate-like retainer (10) is insert-molded, and the end (10a) of the plate-like retainer is interposed between the parallel thin portion (6B) and the lapping margin (5a), and the end (10a) A flange portion (11) with a hole (11a) bent toward the back side so as to enter the lapping margin (5a) is formed at the end.
[0006]
As a result, in the boundary region between the soft layer (6) and the hard layer (5) having different molding pressures, the wrap allowance overlaps the gradually thinned portion (6a) of the soft layer (6), and the foam layer is removed during demolding. The step difference in the amount of springback is suppressed. The end (10a) of the plate-like retainer (10) insert-molded in the soft layer (6) is interposed between the parallel thin portion (6B) and the wrap margin (5a), so that the retainer (10) is securely held. Further, the soft door region is also securely held by the hard layer (5), and the flange portion (11) with a hole (11a ) is insert-molded so that the resin becomes the hole (11a). It is more secure to enter and hold. According to the second aspect of the present invention, a method for manufacturing such an airbag door is provided on the front end surface (22) of the slide core (21) supported so as to be able to advance and retract on one side of the reaction injection mold (20). An inclined receding surface (22a) that recedes from the midpoint of the tip surface (22) toward the inner peripheral edge of the slide core, and a parallel receding surface (22b) parallel to the tip surface from the inclined receding surface to the inner peripheral edge of the slide core. Are formed on the other side of the mold (20) and the parallel receding surface (22b) is set so that the flange (11a) with the hole (11a ) enters the slide core (21). ) With the plate-like retainer (10) set, the slide core (21) is advanced to close the mold (20), and with this mold closed, the inner region of the tip surface (22) To the soft layer (6 In addition, a plate-like retainer (10) is insert-molded into the soft layer, and the inclined thin portion (6A) is formed on the inclined receding surface (22a), and the parallel thin portion (6B) is formed on the parallel receding surface (22b). The slide core (21) is retreated, and the hard layer (5) is formed around the soft layer (6) by reaction injection molding , and the flange (11) with a hole (11a) is formed in the hard layer. Is formed by insert molding.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
An automobile airbag door according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4 by applying it to the airbag door shown in FIG. As described above, the airbag door 2 is relatively rigid in the region of the airbag door 2 in the hard layer 5 as a base material made of rigid urethane foam bonded to the back surface of the skin 4 with the foam layer 4a. A low urethane soft layer 6 is joined and integrally formed with the instrument panel 1 on the passenger seat side.
[0008]
At the end of both ends 10a of the plate-like retainer 10 (see the corresponding retainer 3 described above) with a stud bolt 13 for mounting the airbag body, which is insert-molded into the soft layer, is bent back . The formed flange portion 11 is added to form a hole 11a that allows the resin of the hard layer 5 to penetrate during molding (see FIG. 3).
[0009]
A rectangular slide core 21 defining a door region is supported on the upper mold 20a of the mold 20 so as to be able to advance and retreat, and the inner end of the slide core from the middle position of the front end surface 22 near the inner periphery of the slide core. An inclined receding surface 22a that gradually recedes to an intermediate position is formed, and then a parallel receding surface 22b that is parallel to the distal end surface 22 is formed up to the inner peripheral end of the slide core. Furthermore, the upper mold | type 20a is formed with the convex part 25 (refer FIG. 2) for forming the H-shaped fracture | rupture path 8 corresponding to the shape of the door main body 2a actually opened on both sides.
[0010]
At the time of manufacture, the skin 4 having the foam layer 4a formed on the back surface by vacuum molding, powder slush molding or the like is set on the lower mold 20b of the reaction injection mold 20 (FIGS. 1A and 2A). Next, after the slide core 21 in which the retainer 10 is separably set is advanced to close the mold 20, the inclined receding surface 22a and the inner surface of the front end surface 22 of the slide core 21 are formed by reaction injection molding of urethane material. Corresponding to the shape of the parallel receding surface 22b, the inclined thin portion 6A that gradually becomes thicker from the outer periphery to the inner periphery of the boundary region where the hard layer 5 is superimposed on the back surface of the soft layer 6, and the uniform thickness continuing to the outer periphery side The soft layer 6 with the thin part 6a having the parallel thin part 6B is formed (FIGS. 1B and 2B). At the same time, the plate portion of the retainer 10 is insert-molded. Subsequently, the slide core 21 is moved backward to form the hard layer 5 around the soft layer 6 by the reaction injection molding of urethane material, and the thin portion 6a is formed in the rectangular boundary region corresponding to the shape of the slide core 21. In addition, a lapping margin 5a corresponding to the shapes of the inclined receding surface 22a and the parallel receding surface 22b is formed on the back side.
(FIG. 1C, FIG. 2C). At the same time , the flange portion 11 is insert-molded together with the stud bolt 13 in the hard layer 5 with the end portion 10a of the retainer 10 interposed between the parallel thin portion 6B and the lapping allowance 5a .
[0011]
In such a reaction injection molding, a relatively large molding pressure is generated by foaming of the hard layer 5 in particular, and the foamed layer 4a is relatively strongly compressed. However, in the boundary region with the soft layer 6 having a small molding pressure, a steep change in the molding pressure is mitigated by the presence of the hard wrap margin 5a on the back side of the thin portion 6a, and the outer peripheral portion of the thin portion 6a. As the thickness of the film gradually decreases, it is more reliably avoided that the molding pressure changes stepwise.
[0012]
By removing the mold, the instrument panel 1 in which the airbag door 2 is integrally formed is manufactured (FIGS. 1D and 2D). At that time, the pressure applied by the mold 20 is released to the foam layer 4a and a spring back phenomenon occurs. However, in the boundary region around the airbag door 2, a step change in molding pressure is suppressed and the degree of expansion is reduced. Thus, it is possible to prevent a step from being formed in a rectangular shape in the boundary region of the skin 4.
[0013]
There is a concern that the bonding area between the wrap margin 5a and the thin part 6a may be caused by poor adhesion due to the remaining release agent during the reaction injection molding of the soft layer 6, but the mold surface is coated with Teflon (registered trademark) or the like. Even without the release agent, it is set after the release agent is applied, and it is reliably bonded through the iron retainer 10 having good bondability. Further, the flange portion 11 has the resin of the hard layer 5 intruded into the hole 11a, the soft door region is securely held by the hard layer 5, and the stud bolt 13 and the wrap allowance 5a are also made by the hard wrap allowance 5a. Holds securely. The retainer 10 separated on both sides at the time of the operation of the airbag breaks the door body 2a of the soft layer 6 defined by the H shape with the position of the central breaking path 8 as an open end with the vicinity of the position of the stud bolt 13 as a fulcrum. Open.
[0014]
In addition, as a reference example , the present invention is also applied to a case where another reinforcement is insert-molded without providing a plate-like retainer. Even in such a case, a wrap allowance 6b can be formed as illustrated in FIG. . In this case, it is preferable that the mold is made free from a release agent in consideration of the bonding property between the boundary regions.
[0015]
【The invention's effect】
According to the invention of claim 1, even when the airbag door is formed of soft layers having different molding pressures, the wrap margin of the hard layer is formed on the thin portion that gradually becomes thinner toward the outer periphery of the soft layer in the peripheral boundary region. Overlap, no step is generated in the foam layer of the skin, and the scattering of the resin member in the fracture open area is avoided without impairing the appearance quality. The end of the plate-like retainer that is insert-molded in the soft layer is interposed between the parallel thin portion and the wrap margin, so that the retainer is securely held by the hard layer, and the soft door region is also securely held by the hard layer. In addition, the holding of the flanged portion with holes is further ensured by insert molding in the hard layer.
[0016]
According to the manufacturing method of the second aspect of the present invention, the lap allowance according to the first aspect of the present invention is easily formed using the slide core, and the plate-like retainer and the soft layer that are insert-molded into the soft layer are hard layers. Can be held at the lap cost.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a main part of a manufacturing process of an airbag door according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part for explaining a manufacturing process of the airbag door.
FIG. 3 is a partial perspective view of the retainer of the airbag door.
FIG. 4 is a perspective view of an instrument panel provided with the airbag door. FIG. 5 is a cross-sectional view showing a boundary region between a hard layer and a soft layer as a reference example of the present invention.
FIG. 6 is a cross-sectional view of an airbag door having a configuration as a premise of the present invention .
FIG. 7 is a cross-sectional view of the main part at the time of demolding in the reaction injection process of the conventional airbag door.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Instrument panel 2 Airbag door 4 Skin 4a Foam layer 5 Hard layer 5a Wrap allowance 6 Soft layer 6a Thin part
6A Inclined thin part
6B Thin parallel part 8 Break path 10 Retainer
10a Retainer end 11 Flange 11a Hole 20 Mold 20a Upper mold 20b Lower mold 21 Slide core 22a Inclined receding surface 22b Parallel receding surface

Claims

In contrast to an instrument panel in which a synthetic resin hard layer is integrally formed by reaction injection molding on the skin with the foam layer formed on the back surface, the door area is replaced with a hard layer. A soft layer with a lower rigidity than the hard layer is integrally formed by reaction injection molding, and a break corresponding to the shape is formed so as to form a door body that is opened and broken by the operation of an airbag housed in the instrument panel. In an automobile airbag door where the road is formed in a soft layer,
In the peripheral area of the door body, a boundary area is formed in which a hard layer is overlapped on the back surface of the soft layer, and the soft layer in the boundary area is gradually inclined from the outer periphery to the inner periphery of the boundary area. Form a thin portion having a thin portion and a parallel thin portion of uniform thickness following the inner peripheral side thereof, and form the hard layer overlapping the back surface of the thin portion as a lapping allowance,
A plate-like retainer for holding the airbag body in the soft layer is insert-molded, and an end portion of the plate-like retainer is interposed between the parallel thin portion and the wrap margin, and at the end of the end portion, An automobile airbag door , wherein a flange portion with a hole bent toward the back side so as to enter the wrapping margin is formed.

A method of manufacturing an automobile airbag door according to claim 1,
An inclined receding surface that recedes from a midway position of the distal end surface toward the inner peripheral end of the slide core on the distal end surface of the slide core that is supported so as to be able to advance and retract on one of the molds for reaction injection molding, and the inclined receding surface And a parallel receding surface parallel to the tip surface from the inner periphery of the slide core to the inner periphery.
The slide core is set on the other side of the mold, and the slide core is advanced with the plate-like retainer set on the parallel receding surface so that the flanged portion with a hole penetrates the slide core. Close the mold,
With this mold closed, a soft layer is formed by reaction injection molding in the inner region of the tip surface, and the plate-like retainer is insert-molded into the soft layer, and the inclined thin portion is formed on the inclined receding surface. In addition, a parallel thin part is formed on the parallel receding surface,
The slide core is retracted, a hard layer is formed around the soft layer by reaction injection molding , and the flanged portion with a hole is insert-molded into the hard layer. Method.
.