JP3925242B2

JP3925242B2 - Resin molded product and its insert molding method

Info

Publication number: JP3925242B2
Application number: JP2002053023A
Authority: JP
Inventors: 玉樹浅川
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2002-02-28
Filing date: 2002-02-28
Publication date: 2007-06-06
Anticipated expiration: 2022-02-28
Also published as: JP2003251633A

Description

【０００１】
【発明の属する技術分野】
本発明は、金属板をインサート部材としてその金属板が埋設，一体化された樹脂成形品とその成形品をインサート成形する方法に関し、さらに詳しくは、金属板の上に重なり合うようにしてリブが突設されている場合に、その金属板のうちリブに相当する部分に予め形成された穴を通して金属板の表裏両面側の樹脂層を相互に接続・一体化してなる樹脂成形品とそのインサート成形方法に関する。
【０００２】
【従来の技術】
この種の樹脂成形品およびインサート成形に関する技術として例えば図７〜９に示す構造のものが知られている。この従来の技術では、同図に示すように、一般部樹脂層５１の裏面に露出することになる矩形状の金属板５３をインサート部材としつつリブ５２が突設された複合タイプの樹脂成形品５０を射出成形するにあたり、金属板５３のうちリブ５２の長手方向に沿う部分に予め複数の穴５４を貫通形成しておき、これらの穴５４を通して金属板５３の表面側の一般部樹脂層５１とリブ５２となるべき樹脂層とを相互に接続することにより、金属板５３と、それ以外のリブ５２を含む一般部樹脂層５１との抜け止めもしくは剥離防止を施すようになっている。
【０００３】
そして、このような樹脂成形品５０について、例えば金属板５３をはさんでリブ５２とは反対側の一般部樹脂層５１の表面側を意匠面として使用する場合には、リブ５２の根元厚（図８，９の１／２ｔ相当部）が大きくなればなるほどひけの発生が顕著となることから、リブ５２の根元厚を一般部樹脂層５１の板厚ｔの１／２程度に制限する一方、同時に意匠面となる部位に加飾のために深さが３０μｍ程度のシボ加工を施すことで（シボ加工面を符号５５で示す）、リブ５２の根元部相当部でのひけの発生を抑制しつつ、万が一発生しても目立たないように考慮した構造となっている。
【０００４】
【発明が解決しようとする課題】
このような構造では、インサート部材である金属板５３として例えば一般部樹脂層５１の板厚ｔの１／３程度の厚みのものを使用することから、一般部樹脂層５１そのものと金属板５３との収縮差を無視することができず、特に意匠面であるシボ加工面５５のうち金属板５３側の穴５４相当部でのひけＱの発生が顕著となり、成形品質の向上が望めない。ここで、ひけＱは周知のようにリブ５２やボスの裏面の如き成形品の肉厚の大きな部分に発生しやすく、図９の例ではリブ５２の根元部に内接する仮想円Ｐの直径が大きくなるほどひけの発生が著しいことになる。
【０００５】
本発明はこのような課題に着目してなされたものであり、インサート部材として機能することになる金属板に予めわずかな改良を加えるだけで上記のようなひけの発生を防止して、成形品質の向上を図った樹脂成形品とそのインサート成形方法を提供するものである。
【０００６】
【課題を解決するための手段】
請求項１に記載の発明は、金属板をインサート部材としてその金属板が埋設，一体化されているとともに、その金属板の上に重なり合うようにしてリブが突設されていて、金属板のうちリブに相当する部分に予め形成された穴を通して金属板の表裏両面側の樹脂層を相互に接続・一体化してなる樹脂成形品であって、上記金属板には、リブに相当する部分がそのリブ側に向けて予め切り起こされていることにより切り起こし片部とともに連通穴が形成されていて、この切り起こし片部がリブ根元部の内隅部を支点として斜状に折れ曲がった形状となっているとともに、切り起こし片部の根元部にその金属板の一般面よりも一段低くなるジョッグル面が予め形成されていることを特徴としている。
【０００７】
この場合において、請求項２に記載のように、上記切り起こし片部の先端の一部がリブの根元部の表面に露出するように設定されていると、その切り起こし片部の先端の一部が金型に接触することになるので、インサート部材である位置決め精度向上の上で望ましい。
【０００９】
さらには、請求項３に記載のように、金属板にはリブの長手方向に沿って複数の切り起こし片部が互い違いに形成されていることが樹脂層との接触面積の増大化の上でより望ましい。
【００１０】
したがって、請求項１に記載の発明では、金属板に切り起こし片部を形成したことに伴い同時形成される連通穴は従来と同様の貫通穴として機能することから、インサート部材である金属板をはさんでその表裏両面側の樹脂層が連通穴を通して相互に接続される。その一方、連通穴相当部には斜状に折れ曲がった形状の切り起こし片部が形成されているので、貫通穴として機能すべき連通穴の有効開口面積は従来のものより著しく小さいものとなり、リブの根元部における局部的な厚肉化が回避される。その結果として、リブに相当する部分でのひけの発生が抑制されることになる。
【００１１】
その上、金属板のうち切り起こし片部の根元部にその金属板の一般面よりも一段低くなるジョッグル面が予め形成されているので、その切り起こし片部自体に弾性変形による自由度を持たせることができるようになり、例えば切り起こし片部の折れ曲がり角度として充分な精度を有していない場合でも、射出圧によって切り起こし片部を弾性変形させて金型に当接させることができるようになる。
【００１２】
特に、請求項２に記載のように切り起こし片部の先端の一部がリブの根元部の表面に露出してことは、その切り起こし片部の先端の一部が金型に直接接触していて位置決めされていることにほかならず、したがって射出圧を受けたとしてもインサート部材である金属板の位置ずれを未然に防止できるようになる。
【００１３】
ここで、請求項１の記載において、切り起こし片部がリブの根元部を支点として斜状に折れ曲がった形状となっていることは、切り起こし片部の根元部がリブ根元部の内隅部に一致していて、実質的に射出成形時に切り起こし片部の根元部が上記リブ根元部の内隅部の成形を司る金型の一部に当接することを意味する。
【００１５】
請求項４に記載の発明は、上記記載事項を前提として、請求項２に記載の樹脂成形品を射出成形法によりインサート成形する方法であって、上記金属板には、リブに相当する部分がそのリブ側に向けて予め切り起こされていることにより切り起こし片部とともに連通穴が形成されていて、この切り起こし片部がリブ根元部の内隅部を支点として斜状に折れ曲がった形状となるように、その切り起こし片部をリブ根元部の内隅部の成形を司る金型の一部に当接させるとともに、上記切り起こし片部の先端をリブ根元部の反対側の内隅部の成形を司る金型の一部に当接させた状態で一体成形することを特徴としている。
【００１６】
【発明の効果】
請求項１に記載の発明によれば、インサート部材として埋設されることになる金属板に連通穴とともに形成された切り起こし片部がリブ根元部の内隅部を支点として斜状に折れ曲がった形状となっているため、従来と同等の機能を有しながらもリブ根元部での厚肉化が回避されて、そのリブ相当部でのひけの発生を抑制できるようになる。また、切り起こし片部の根元部にその金属板の一般面よりも一段低くなるジョッグル面を形成したことにより、切り起こし片部をその根元部から積極的に弾性変形させて、例えば切り起こし片部の傾斜角精度が充分でない場合に射出圧により撓ませて金型に接触させることが可能であり、切り起こし片部の形状精度出しをより確実に行えるとともに、ひけ発生度合いのばらつきを解消できる利点がある。
【００１７】
請求項２，４に記載の発明によれば、切り起こし片部の根元部だけでなくその先端の一部までもが金型の一部に接触することで直接的に位置決めされるため、請求項１に記載の発明と同様の効果に加えて、射出圧による金属板の位置ずれを確実に防止して、その位置決め精度の一層の向上が図れる利点がある。
【００１９】
請求項３に記載の発明によれば、金属板にリブの長手方向に沿って複数の切り起こし片部を互い違いに形成したことにより、請求項１または２に記載の発明と同様の効果に加えて、樹脂層とインサート部材である金属板との接触面積をより大きく確保して、両者の接合強度を一段と高めることができる利点がある。
【００２０】
【発明の実施の形態】
図１〜３は本発明の好ましい実施の形態を示す図であり、特に図１は樹脂成形品の要部斜視図を、図２の（Ａ）はインサート部材として樹脂成形品に埋設されることになる金属板単独での斜視図を、同図（Ｂ）は図１および図２の（Ａ）のａ−ａ線に沿う断面図をそれぞれ示している。
【００２１】
図１，２に示すように、略矩形状の樹脂成形品１は同じく矩形状の金属板２をインサート部材として射出成形法により一体成形されたもので、意匠面となる表面側にはシボ加工が施されているとともに（シボ加工面を符号３で示す）、裏面側には剛性確保のための補強用のリブ４が一体に突出形成されている。なお、金属板２としては一般部樹脂層５の厚みｔの１／３ｔ程度の厚みのものが使用され、一般部樹脂層５の裏面側にそれと面一状態となるように大きく露出している。また、リブ４の根元部での厚みは図２の（Ｂ）のように一般部樹脂層５の厚みｔの１／２ｔ程度の大きさに設定されている。
【００２２】
インサート部材として機能する金属板２のうちリブ４に相当する部分には、その長手方向に沿って複数の切り起こし片部６が互い違いにもしくは千鳥状に並設されている。これらの切り起こし部６は、金属板２の一般面よりも一段低くなるジョッグル面７を印圧成形しつつその印圧方向と反対側に切り起こし片部６を切り起こしつつ斜状に折り曲げたもので、その切り起こし片部６の先端部側を一般面よりも突出させることで金属板２を板厚方向に貫通する連通穴８が同時形成される。そして、このような金属板２をインサート部材として樹脂成形品１の射出インサート成形を行った時には、金属板２の一部が樹脂成形品１の一部と面一状態となって露出することはあっても、樹脂成形品１の輪郭よりも外側に突出することがないように設定されている。
【００２３】
したがって、このような樹脂成形品１を常法により成形する場合には、図３に示すように製品形状部となる金型９のキャビティＲ内にインサート部材たる金属板２を予め位置決めすることになるが、リブ４の根元部おける一方の内隅部１０の成形を司ることになる金型９のコーナー部１１に切り起こし片部６の根元部を当接させ、同時にリブ４の根元部おける他方の内隅部１２の成形を司ることになる金型９の内側面に切り起こし片部６の先端を当接させて位置決めする。こうすることにより、例え樹脂材料の射出圧を受けたとしても金属板２の位置ずれが生じにくく、その位置決め精度が良好なものとなる。
【００２４】
金属板２が位置決めされたならば、公知の方法によりキャビティＲ内に樹脂材料を射出して成形を行う。そして、例えば図３に示すように一般部樹脂層５となるべき部位から樹脂材料が射出されるものとすると、樹脂材料は各切り起こし片部６に付帯している連通穴８を通してリブ４側にまで充満し、金属板２の表面側の一般部樹脂層５と裏面側のリブ４とが上記連通穴８の樹脂層をもって相互に接続されて両者の抜け止めもしくは剥離防止が施されることになる。同時に各切り起こし片部６のジョッグル面７も樹脂にて埋設されるとともに、一般部脂層５の表面には従来と同様にシボ加工によるシボ加工面３が形成される。
【００２５】
また、金属板２の寸法ばらつきにより、例えばリブ４の根元部おける一方の内隅部１０の成形を司ることになる金型のコーナー部１１に切り起こし片部６の根元部が当接していないような場合には、射出圧（樹脂圧）を受けて切り起こし片部６がその根元部から弾性変形して上記金型９側のコーナー部１１に確実に当接するようになる。
【００２６】
そして、成形後の樹脂成形品１は、図１，２に示すように一般部樹脂層５と面一状態となるように金属板２が一体的に埋設され、同時にリブ４の根元部における内隅部１０，１２には金属板２の一部が露出するかたちとなる。
【００２７】
このような樹脂成形品１においては、一般部樹脂層５とリブ４を形成している樹脂層とが連通穴８を通して相互に接続されてはいても、リブ４の根元部には斜状の切り起こし片部６が位置しているため、図９のものと比べてそのリブ４根元部での厚肉化が極力回避されて、一般部５の表面と金属板２との間に内接する仮想円Ｐの直径が図９に比べて小さくなっている。これにより、一般部樹脂層５の表面側のうちリブ４に相当する部分でのひけの発生が大幅に抑制される。
【００２８】
しかも、切り起こし片部６の根元部に一般面よりも一段低いジョッグル面７が予め形成されていることにより、先に述べたように切り起こし片部６を射出圧によって積極的に弾性変形させることが可能となり、これによって切り起こし片部６を金型９側のコーナー部１１に確実に当接させることができるほか、最終的にはそのジョッグル面７が樹脂にて覆われるのに加えて、複数の切り起こし片部６がリブ４の長手方向に沿って並設されていることで金属板２と一般部樹脂層５との接触面積の増大により両者の接合強度も高くなる。
【００２９】
図４〜６は本発明のより具体的な第２の実施の形態として自動車の樹脂製バックドア２１に適用した例を示し、図４はそのドアインナパネル単独での正面図を、図５は図４，６のｂ−ｂ線に沿う拡大断面図を、図６は図４のＤ部の拡大分解図をそれぞれ示している。
【００３０】
図４〜６に示すように、バックドア２１は略枠状のドアアウタパネル２２とほぼ同形状のドアインナパネル２３とを備えていて、両者を例えば接着剤にて接合することにより構成される。ドアインナパネル２３は、その剛性確保のための第１の実施の形態のものと同様にインサート部材として例えば断面略Ｌ字状をなす金属板２４が埋設されているとともに、その要所要所にリブ２５が突設されている。金属板２４のうちリブ２５に相当する部分では図２と同様にして連通穴８が付帯することになる切り起こし片部６がリブ２５の長手方向に沿って互い違いに形成されていて、上記連通穴８を通してドアインナパネル２３の一般部２６とリブ２５とが相互に接続されていることになる。
【００３１】
この第２の実施の形態においても、基本的には第１の実施の形態のものと同一構造となっていることから、特にドアインナパネル２３の意匠面としてのその表面側におけるひけ発生防止効果が発揮されることになる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態として樹脂成形品の概略構造を示す要部斜視図。
【図２】（Ａ）は図１の樹脂成形品にインサート部材として埋設されることになる金属板単独での斜視図、（Ｂ）は同図（Ａ）のａ−ａ線に沿う拡大断面図。
【図３】図２の（Ｂ）と同等部位での射出成形用金型の断面図。
【図４】本発明の第２の実施の形態を示す図で、自動車のバックドアインナパネルの正面図。
【図５】図４および図６のｂ−ｂ線に沿う拡大断面図。
【図６】図４のＤ部相当部での分解斜視図。
【図７】インサート成形タイプの樹脂成形品の一例を示す要部斜視図。
【図８】図７の正面図。
【図９】図７のｃ−ｃ線に沿う断面図。
【符号の説明】
１…樹脂成形品
２…金属板（インサート部材）
４…リブ
５…一般部樹脂層
６…切り起こし片部
７…ジョッグル面
８…連通穴
９…金型
１０，１２…内隅部
２３…バックドアインナパネル（樹脂成形品）
２４…金属板（インサート部材）
２５…リブ
２６…一般部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molded product in which the metal plate is embedded and integrated using the metal plate as an insert member, and a method of insert-molding the molded product. More specifically, the rib protrudes so as to overlap the metal plate. A resin molded product in which the resin layers on both the front and back sides of the metal plate are mutually connected and integrated through holes formed in advance in the portion corresponding to the rib of the metal plate, and its insert molding method. About.
[0002]
[Prior art]
As a technique relating to this type of resin molded product and insert molding, for example, those having structures shown in FIGS. 7 to 9 are known. In this prior art, as shown in the figure, a composite type resin molded product in which ribs 52 are projected while a rectangular metal plate 53 that is exposed on the back surface of the general resin layer 51 is used as an insert member. In injection molding 50, a plurality of holes 54 are formed in advance in portions of the metal plate 53 along the longitudinal direction of the ribs 52, and the general resin layer 51 on the surface side of the metal plate 53 is passed through these holes 54. And the resin layer to be the rib 52 are connected to each other, thereby preventing the metal plate 53 and the general resin layer 51 including the other ribs 52 from coming off or preventing peeling.
[0003]
And about such a resin molded product 50, when using the surface side of the general part resin layer 51 on the opposite side to the rib 52 across the metal plate 53 as a design surface, for example, the base thickness ( Since the occurrence of sink marks becomes more significant as the portion corresponding to 1 / 2t in FIGS. 8 and 9 becomes larger, the root thickness of the rib 52 is limited to about 1/2 of the plate thickness t of the general resin layer 51. At the same time, the surface of the design surface is subjected to embossing with a depth of about 30 μm for decoration (the embossed surface is indicated by reference numeral 55), thereby suppressing the occurrence of sink marks at the base portion corresponding to the rib 52. However, the structure is designed so that it does not stand out even if it occurs.
[0004]
[Problems to be solved by the invention]
In such a structure, since the metal plate 53 that is an insert member has a thickness of about 1/3 of the thickness t of the general resin layer 51, for example, the general resin layer 51 itself and the metal plate 53 The shrinkage difference cannot be ignored, and in particular, the occurrence of sink marks Q in the portion corresponding to the hole 54 on the metal plate 53 side in the embossed surface 55 which is a design surface becomes remarkable, and improvement in molding quality cannot be expected. Here, as is well known, sink marks Q are likely to occur in a thick portion of the molded product such as the rib 52 or the back surface of the boss. In the example of FIG. 9, the diameter of the virtual circle P inscribed in the root portion of the rib 52 is The larger the size, the more marked the occurrence of sink marks.
[0005]
The present invention has been made paying attention to such a problem, and it is possible to prevent the occurrence of sinks as described above by simply making a slight improvement in advance on a metal plate that will function as an insert member. A resin molded product and an insert molding method thereof are provided.
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, the metal plate is embedded and integrated using the metal plate as an insert member, and the rib is projected so as to overlap the metal plate. A resin molded product obtained by connecting and integrating the resin layers on both the front and back sides of a metal plate through holes formed in advance in a portion corresponding to a rib. The metal plate includes a portion corresponding to a rib. The cut hole is formed in advance with the cut and raised piece by being cut and raised in advance toward the rib side, and the cut and raised piece is bent obliquely with the inner corner of the rib root as a fulcrum. And a joggle surface that is one step lower than the general surface of the metal plate is formed in advance at the base of the cut and raised piece .
[0007]
In this case, as described in claim 2, if a part of the tip of the cut-and-raised piece portion is set to be exposed on the surface of the root portion of the rib, one end of the cut-and-raised piece portion is provided. Since the portion comes into contact with the mold, it is desirable for improving positioning accuracy as an insert member.
[0009]
Furthermore, as described in claim 3 , the metal plate has a plurality of cut and raised pieces formed alternately along the longitudinal direction of the ribs in order to increase the contact area with the resin layer. More desirable.
[0010]
Therefore, in the invention according to claim 1, since the communication holes formed simultaneously with the cut and raised pieces formed on the metal plate function as through holes as in the conventional case, the metal plate as the insert member is The resin layers on both sides of the front and back are connected to each other through the communication hole. On the other hand, since the cut-and-raised piece portion that is bent obliquely is formed in the communication hole equivalent portion, the effective opening area of the communication hole that should function as a through hole is significantly smaller than the conventional one, and the rib A local thickening at the root of the shell is avoided. As a result, the occurrence of sink marks at the portion corresponding to the rib is suppressed.
[0011]
In addition, since the joggle surface that is one step lower than the general surface of the metal plate is formed in advance at the base of the cut and raised piece portion of the metal plate, the cut and raised piece portion itself has a degree of freedom due to elastic deformation. For example, even when the bending angle of the cut and raised piece portion does not have sufficient accuracy, the cut and raised piece portion can be elastically deformed by the injection pressure and brought into contact with the mold. become.
[0012]
In particular, as described in claim 2, a part of the tip of the cut and raised piece part is exposed on the surface of the base part of the rib. This means that the part of the tip of the cut and raised piece part directly contacts the mold. Therefore, even if the injection pressure is applied, the displacement of the metal plate as the insert member can be prevented in advance.
[0013]
Here, in the description of claim 1, the cut-and-raised piece portion has a shape bent obliquely with the root portion of the rib as a fulcrum, so that the root portion of the cut-and-raised piece portion is the inner corner of the rib root portion. It means that the root part of the piece part cut and raised substantially at the time of injection molding comes into contact with a part of the mold that controls the inner corner part of the rib base part.
[0015]
The invention described in claim 4 is a method of insert- molding the resin molded product according to claim 2 by an injection molding method on the premise of the above-described matters, and the metal plate has a portion corresponding to a rib. A communication hole is formed together with the cut and raised piece by being cut and raised in advance toward the rib side, and the cut and raised piece is bent obliquely with the inner corner of the rib root as a fulcrum. The cut and raised piece is brought into contact with a part of a mold for forming the inner corner of the rib base, and the tip of the cut and raised piece is the inner corner on the opposite side of the rib root. It is characterized in that it is integrally molded in a state where it is in contact with a part of a mold that controls the molding.
[0016]
【The invention's effect】
According to the first aspect of the present invention, the cut-and-raised piece portion formed with the communication hole in the metal plate to be embedded as the insert member is bent obliquely with the inner corner portion of the rib base portion as a fulcrum. Therefore, while having a function equivalent to that of the conventional art, thickening at the rib base portion is avoided, and occurrence of sink marks at the rib corresponding portion can be suppressed. In addition, by forming a joggle surface that is one step lower than the general surface of the metal plate at the base part of the cut and raised piece part, the cut and raised piece part is positively elastically deformed from the root part, for example, the cut and raised piece When the inclination angle accuracy of the part is not sufficient, it can be bent by the injection pressure and brought into contact with the mold, and the shape accuracy of the cut and raised piece part can be more reliably determined, and the variation in the degree of occurrence of sink marks can be eliminated. There are advantages.
[0017]
According to the second and fourth aspects of the invention, not only the root part of the cut and raised piece part but also a part of the tip thereof is directly positioned by contacting a part of the mold. In addition to the effect similar to that of the invention described in item 1, there is an advantage that the positional deviation of the metal plate due to the injection pressure can be reliably prevented and the positioning accuracy can be further improved.
[0019]
According to the invention described in claim 3, in addition to the same effect as that of the invention described in claim 1 or 2 , the metal plate is formed with a plurality of cut and raised pieces along the longitudinal direction of the rib. Thus, there is an advantage that a larger contact area between the resin layer and the metal plate as the insert member can be ensured, and the joint strength between them can be further increased.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 are diagrams showing a preferred embodiment of the present invention. In particular, FIG. 1 is a perspective view of a principal part of a resin molded product, and FIG. 2A is embedded in a resin molded product as an insert member. A perspective view of the metal plate alone is shown, and FIG. 5B is a cross-sectional view taken along the line aa in FIG. 1 and FIG.
[0021]
As shown in FIGS. 1 and 2, a substantially rectangular resin molded product 1 is also integrally molded by an injection molding method using a rectangular metal plate 2 as an insert member. (The embossed surface is indicated by reference numeral 3), and a reinforcing rib 4 for securing rigidity is integrally formed on the back surface side. The metal plate 2 has a thickness of about 1 / 3t of the thickness t of the general resin layer 5 and is largely exposed on the back side of the general resin layer 5 so as to be flush with it. . Further, the thickness at the base portion of the rib 4 is set to a size of about 1/2 t of the thickness t of the general resin layer 5 as shown in FIG.
[0022]
In a portion corresponding to the rib 4 of the metal plate 2 functioning as an insert member, a plurality of cut and raised pieces 6 are arranged alternately or in a staggered manner along the longitudinal direction. These cut-and-raised portions 6 were bent in a slanting manner while cutting and raising the piece portion 6 while cutting and raising the jog surface 7 which is one step lower than the general surface of the metal plate 2 while printing and forming the jog surface 7. Thus, the communicating hole 8 penetrating the metal plate 2 in the plate thickness direction is simultaneously formed by projecting the tip end side of the cut and raised piece portion 6 from the general surface. And when injection insert molding of the resin molded product 1 is performed using such a metal plate 2 as an insert member, a part of the metal plate 2 is exposed to be flush with a part of the resin molded product 1. Even if it exists, it is set so that it may not protrude outside the outline of the resin molded product 1.
[0023]
Therefore, when such a resin molded product 1 is molded by a conventional method, as shown in FIG. 3, the metal plate 2 as an insert member is positioned in advance in the cavity R of the mold 9 as a product shape portion. However, the base portion of the piece portion 6 is brought into contact with the corner portion 11 of the mold 9 which is responsible for forming one inner corner portion 10 at the base portion of the rib 4, and at the same time at the base portion of the rib 4. The other inner corner 12 is formed by cutting and raising on the inner surface of the mold 9 that will control the inner corner 12 and bringing the tip of the piece 6 into contact. By doing so, even if the injection pressure of the resin material is applied, the metal plate 2 is hardly displaced, and the positioning accuracy is good.
[0024]
When the metal plate 2 is positioned, the resin material is injected into the cavity R by a known method to perform molding. Then, for example, as shown in FIG. 3, if the resin material is injected from a portion that should become the general resin layer 5, the resin material passes through the communication hole 8 attached to each cut-and-raised piece 6 and is on the rib 4 side. And the general resin layer 5 on the front side of the metal plate 2 and the rib 4 on the back side are connected to each other with the resin layer of the communication hole 8 to prevent the both from coming off or preventing peeling. become. At the same time, the joggle surface 7 of each cut-and-raised piece 6 is also embedded with resin, and a textured surface 3 is formed on the surface of the general part grease layer 5 by a textured process as in the prior art.
[0025]
Further, due to the dimensional variation of the metal plate 2, for example, the root portion of the piece portion 6 is not brought into contact with the corner portion 11 of the mold that controls the formation of one inner corner portion 10 at the base portion of the rib 4. In such a case, the cut-and-raised piece portion 6 is elastically deformed from the base portion under the injection pressure (resin pressure), and comes into contact with the corner portion 11 on the mold 9 side with certainty.
[0026]
As shown in FIGS. 1 and 2, the molded resin product 1 after molding is integrally embedded with a metal plate 2 so as to be flush with the general resin layer 5, and at the same time, the inner portion of the rib 4 at the root portion. A part of the metal plate 2 is exposed at the corners 10 and 12.
[0027]
In such a resin molded product 1, even if the general resin layer 5 and the resin layer forming the rib 4 are connected to each other through the communication hole 8, the root portion of the rib 4 has an oblique shape. Since the cut-and-raised piece portion 6 is located, the thickness of the base portion of the rib 4 is avoided as much as possible as compared with that of FIG. 9, and is inscribed between the surface of the general portion 5 and the metal plate 2. The diameter of the virtual circle P is smaller than that in FIG. As a result, the occurrence of sink marks in the portion corresponding to the rib 4 in the surface side of the general resin layer 5 is greatly suppressed.
[0028]
Moreover, since the joggle surface 7 that is one step lower than the general surface is formed in advance at the root of the cut and raised piece 6, the cut and raised piece 6 is positively elastically deformed by the injection pressure as described above. As a result, the cut-and-raised piece 6 can be reliably brought into contact with the corner 11 on the mold 9 side, and finally the joggle surface 7 is covered with resin. Since the plurality of cut-and-raised pieces 6 are arranged in parallel along the longitudinal direction of the rib 4, the contact area between the metal plate 2 and the general resin layer 5 is increased, so that the bonding strength between them is increased.
[0029]
4 to 6 show an example in which the present invention is applied to an automobile resin back door 21 as a more specific second embodiment of the present invention, FIG. 4 is a front view of the door inner panel alone, and FIG. 4 and 6 are enlarged sectional views taken along the line bb of FIG. 4, and FIG. 6 is an enlarged exploded view of part D of FIG.
[0030]
As shown in FIGS. 4 to 6, the back door 21 includes a substantially frame-shaped door outer panel 22 and a door inner panel 23 having substantially the same shape, and is configured by joining the two together with an adhesive, for example. The door inner panel 23 is embedded with, for example, a metal plate 24 having a substantially L-shaped cross section as an insert member in the same manner as in the first embodiment for securing its rigidity, and ribs are provided at necessary points. 25 is protrudingly provided. In the portion corresponding to the ribs 25 in the metal plate 24, the cut and raised pieces 6 to which the communication holes 8 are attached are formed alternately along the longitudinal direction of the ribs 25 in the same manner as in FIG. The general portion 26 and the rib 25 of the door inner panel 23 are connected to each other through the hole 8.
[0031]
Also in the second embodiment, since it basically has the same structure as that of the first embodiment, the effect of preventing the occurrence of sink marks particularly on the surface side as the design surface of the door inner panel 23. Will be demonstrated.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic structure of a resin molded product according to a first embodiment of the present invention.
2A is a perspective view of a metal plate alone to be embedded as an insert member in the resin molded product of FIG. 1, and FIG. 2B is an enlarged cross section taken along the line aa in FIG. Figure.
3 is a cross-sectional view of an injection mold at the same site as FIG. 2B. FIG.
FIG. 4 is a diagram showing a second embodiment of the present invention and a front view of a back door inner panel of an automobile.
5 is an enlarged cross-sectional view taken along the line bb in FIGS. 4 and 6. FIG.
6 is an exploded perspective view of a portion corresponding to portion D in FIG. 4;
FIG. 7 is a perspective view of an essential part showing an example of an insert molding type resin molded product.
8 is a front view of FIG. 7. FIG.
9 is a cross-sectional view taken along the line cc of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Resin molded product 2 ... Metal plate (insert member)
4 ... rib 5 ... general part resin layer 6 ... cut and raised piece part 7 ... jogging surface 8 ... communication hole 9 ... mold 10, 12 ... inner corner 23 ... back door inner panel (resin molded product)
24 ... Metal plate (insert member)
25 ... Rib 26 ... General part

Claims

The metal plate is embedded and integrated using the metal plate as an insert member, and a rib is projected so as to overlap the metal plate, and is formed in advance on a portion of the metal plate corresponding to the rib. A resin molded product that connects and integrates the resin layers on the front and back sides of a metal plate through a hole,
In the metal plate, a portion corresponding to the rib is cut and raised in advance toward the rib side, so that a communication hole is formed together with the cut and raised piece portion,
This cut and raised piece has a shape bent obliquely with the inner corner of the rib base as a fulcrum ,
A resin molded product, wherein a joggle surface that is one step lower than a general surface of the metal plate is formed in advance at the base of the cut and raised piece .

The resin molded product according to claim 1, wherein a part of the tip of the cut and raised piece part is exposed on the surface of the base part of the rib.

3. The resin molded product according to claim 1, wherein a plurality of cut and raised pieces are alternately formed along the longitudinal direction of the ribs on the metal plate.

A method of insert molding the resin molded product according to claim 2 by an injection molding method ,
In the metal plate, a portion corresponding to the rib is cut and raised in advance toward the rib side, so that a communication hole is formed together with the cut and raised piece portion,
The die that controls the forming of the inner corner of the rib base is formed so that the cut and raised piece is bent obliquely with the inner corner of the rib base as a fulcrum. In addition to being brought into contact with a part, the tip of the cut-and-raised piece part is integrally molded in a state of being brought into contact with a part of a mold that controls the molding of the inner corner on the opposite side of the rib base part. Insert molding method.