JPH06339975A - Hollow resin molded piece and manufacture thereof - Google Patents
Hollow resin molded piece and manufacture thereofInfo
- Publication number
- JPH06339975A JPH06339975A JP12977193A JP12977193A JPH06339975A JP H06339975 A JPH06339975 A JP H06339975A JP 12977193 A JP12977193 A JP 12977193A JP 12977193 A JP12977193 A JP 12977193A JP H06339975 A JPH06339975 A JP H06339975A
- Authority
- JP
- Japan
- Prior art keywords
- cavity
- thick
- resin
- thin
- molded product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は内部に空洞を有する樹脂
成形品とその製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded product having a cavity inside and a method for manufacturing the same.
【０００２】[0002]
【従来の技術】樹脂成形品の軽量化あるいは樹脂使用量
の低減を目的として、車両用樹脂成形品を中心に内部に
空洞を有する樹脂成形品が提案されている（例えば特開
平３−２４８９３７号、実開平２−６３２５５号）。こ
れらの樹脂成形品は射出成形時に圧縮ガスを注入して、
内部全体に空洞を形成したものである。しかし、このよ
うな成形品においても、くり返し多数の成形を行う際に
常に同一形状の空洞を得ることは経験上難かしく、形状
は通常ばらつき、この結果細部についてみると、樹脂の
肉厚に差が生じ、肉厚の厚い部分ではひけが生じて外観
を害したり、あるいは内部応力の不均一によりねじれ等
の変形が生じ、取付性を害するなどの問題点がある。2. Description of the Related Art For the purpose of reducing the weight of a resin molded product or reducing the amount of resin used, there has been proposed a resin molded product having a cavity inside, mainly a vehicle resin molded product (for example, Japanese Patent Laid-Open No. 3-248937). , Jitsukaihei 2-63255). These resin molded products are injected with compressed gas during injection molding,
A cavity is formed in the entire interior. However, even in the case of such molded products, it is difficult to always obtain a cavity of the same shape when repeatedly molding many times, and the shapes usually vary, and as a result, when looking at the details, there is a difference in the resin thickness. Occurs, and a sink mark is generated in a thick portion to impair the external appearance, or deformation such as twisting due to uneven internal stress occurs, which impairs the mountability.
【０００３】一方、このような空洞を有する樹脂成形品
の裏面側を開口させた内部空間を有する樹脂成形品が望
まれている。図８は車両用のスポイラとして使用される
樹脂成形品の斜視図、図９はこのような成形品として一
般的に考えられるであろう樹脂成形品の構造を示す図８
のＸ−Ｘ断面図である。On the other hand, there is a demand for a resin molded product having an internal space in which the back side of the resin molded product having such a cavity is opened. FIG. 8 is a perspective view of a resin molded product used as a spoiler for a vehicle, and FIG. 9 shows a structure of a resin molded product generally considered as such a molded product.
FIG.
【０００４】図において、１は樹脂成形品で、外表面側
は意匠部２となり、内部空間３を囲むように取付部４が
裏面側に伸び、内部空間３は裏面側に開口している。こ
の成形品１では意匠部２から取付部４までを軽量化のた
め、主として厚さｄ1、ｄ2の薄肉部５で一体に成形す
る。ただし、取付部４の強度不足が予測される場合には
新規な構造として、同図における破線４ａで示すよう
に、取付部４は取付強度を確保するため、厚さＤ1、Ｄ2
（＞ｄ1、ｄ2）の厚肉部６を形成し、全体が一体成形さ
れた成形品も考えられる。In the drawing, reference numeral 1 denotes a resin molded product, the outer surface side of which serves as a design portion 2, a mounting portion 4 extends to the back surface side so as to surround the internal space 3, and the internal space 3 is open to the back surface side. In order to reduce the weight of the design part 2 to the mounting part 4 in this molded product 1, the thin part 5 having thicknesses d 1 and d 2 is integrally molded. However, in the case where the strength of the mounting portion 4 is predicted to be insufficient, as a new structure, as shown by the broken line 4a in the figure, the mounting portion 4 has thicknesses D 1 and D 2 in order to secure the mounting strength.
A molded product in which the thick part 6 of (> d 1 , d 2 ) is formed and the whole is integrally molded is also conceivable.
【０００５】上記の樹脂成形品１は取付部４の先端（裏
面）に両面粘着テープ等の固着手段７を介在させて、車
体パネル等の被取付部８に取付けて使用される。The above-mentioned resin molded product 1 is used by being attached to a mounting portion 8 such as a vehicle body panel with a fixing means 7 such as a double-sided adhesive tape interposed at the tip (back surface) of the mounting portion 4.
【０００６】[0006]
【発明が解決しようとする課題】しかしながら、このよ
うな樹脂成形品１は薄肉部５と厚肉部６とが一体成形さ
れる構造となっているため、これを射出成形により一体
成形すると、厚肉部６の冷却固化が遅れ、厚肉部６の外
表面側にひけが発生して外観を害するほか、内部応力が
不均一となって成形品全体がねじれるなどの変形が発生
し、取付部４における取付性を害するなどの問題点があ
る。However, since such a resin molded product 1 has a structure in which the thin wall portion 5 and the thick wall portion 6 are integrally molded, if they are integrally molded by injection molding, Cooling and solidification of the thick portion 6 is delayed, sink marks occur on the outer surface side of the thick portion 6 to impair the external appearance, and internal stress becomes non-uniform, causing deformation such as twisting of the entire molded product, and There are problems such as impairing the attachability in No. 4.
【０００７】本発明の目的は、薄肉部には空洞を形成せ
ず厚肉部に内部空洞を形成することにより、薄肉部と厚
肉部が一体成形された樹脂成形品におけるひけやねじれ
等の変形を防止し、軽量で外観および取付性に優れた樹
脂成形品およびその製造方法を得ることである。An object of the present invention is to form an internal cavity in a thick portion without forming a cavity in the thin portion, so that a sink or a twist in a resin molded product in which the thin portion and the thick portion are integrally molded. (EN) It is possible to obtain a resin molded product which prevents deformation, is lightweight, and has excellent appearance and mountability, and a manufacturing method thereof.
【０００８】[0008]
【課題を解決するための手段】本発明は次の樹脂成形品
およびその製造方法である。 （１）ほぼ同一の厚さの板状の薄肉部、および薄肉部の
厚さよりも厚い厚さの厚肉部が一体成形され、前記厚肉
部には内部に実質的に密閉された空洞が形成されてお
り、この空洞は厚肉部の外形のほぼ相似的縮小形に形成
され、かつ薄肉部には実質的に及んでいないことを特徴
とする樹脂成形品。 （２）意匠部となる薄肉部および取付部となる厚肉部が
一体成形され、厚肉部に空洞が形成されていることを特
徴とする上記（１）記載の樹脂成形品。 （３）厚肉部には空洞と連結する通気路を有することを
特徴とする上記（１）または（２）記載の樹脂成形品。 （４）ほぼ同一のすき間を面状に有する薄肉部形成部
と、前記すき間よりも大きいすき間の厚肉部形成部とか
らなるキャビティ、および前記厚肉部形成部に圧縮ガス
注入口を有する射出成形型を用い、キャビティに溶融樹
脂を射出し、射出した樹脂がガス注入口を覆った後で、
樹脂がキャビティ内を満たす前に圧縮ガスを注入して、
キャビティ内の樹脂を圧縮ガスとともに流動させること
により、薄肉部形成部で薄肉部を形成し、厚肉部形成部
で厚肉部を形成するとともに、厚肉部の内部に、厚肉部
の外形のほぼ相似的縮小形を有し、実質的に密閉され、
かつ実質的に薄肉部に及んでいない空洞を形成すること
を特徴とする樹脂成形品の製造方法。 （５）ガス注入口は射出成形型のゲートに対向する位置
に形成することを特徴とする上記（４）記載の樹脂成形
品の製造方法。 （６）ガス注入口は射出成形型の凹部に形成することを
特徴とする上記（４）または（５）記載の樹脂成形品の
製造方法。The present invention provides the following resin molded product and its manufacturing method. (1) A plate-shaped thin portion having substantially the same thickness and a thick portion having a thickness larger than that of the thin portion are integrally molded, and the thick portion has a cavity that is substantially sealed inside. A resin molded product characterized in that the cavity is formed to have a reduced shape which is substantially similar to the outer shape of the thick portion and does not substantially extend to the thin portion. (2) The resin molded product according to the above (1), wherein a thin portion serving as a design portion and a thick portion serving as a mounting portion are integrally molded, and a cavity is formed in the thick portion. (3) The resin molded product according to the above (1) or (2), characterized in that the thick portion has an air passage connected to the cavity. (4) Cavity composed of thin-walled portion forming portion having substantially the same gap in a plane and thick-walled portion forming portion having a gap larger than the gap, and injection having a compressed gas injection port in the thick-walled portion forming portion Using a mold, inject molten resin into the cavity, and after the injected resin covers the gas inlet,
Inject compressed gas before the resin fills the cavity,
By flowing the resin in the cavity with the compressed gas, the thin-walled portion forming portion forms a thin-walled portion, the thick-walled portion forming portion forms a thick-walled portion, and the outer shape of the thick-walled portion is formed inside the thick-walled portion. Has a substantially similar reduced form of and is substantially enclosed,
A method for producing a resin molded product, characterized in that a cavity that does not substantially extend to the thin portion is formed. (5) The method for producing a resin molded product according to the above (4), wherein the gas injection port is formed at a position facing the gate of the injection molding die. (6) The method for producing a resin molded product according to the above (4) or (5), characterized in that the gas injection port is formed in the recess of the injection mold.
【０００９】本発明において「厚肉部」とは、内部に空
洞を有する場合でも、外形の厚さが厚い部分をいい、
「薄肉部」はこの「厚肉部」よりも外形の厚さが薄い部
分をいう。In the present invention, the "thick portion" means a portion having a large outer thickness even if it has a cavity inside,
The “thin-walled portion” refers to a portion having a thinner outer shape than the “thick-walled portion”.
【００１０】[0010]
【作用】本発明の樹脂成形品は、射出成形型のキャビテ
ィに樹脂を射出し、樹脂がガス注入口を覆った後に、キ
ャビティに圧縮ガスを注入することにより、薄肉部形成
部で薄肉部を形成し、厚肉部形成部で厚肉部を形成する
とともに、厚肉部の内部に、厚肉部の外形のほぼ相似的
縮小形を有し、実質的に密閉され、かつ実質的に薄肉部
に及んでいない空洞を形成して製造する。In the resin molded product of the present invention, the resin is injected into the cavity of the injection mold, and after the resin covers the gas injection port, the compressed gas is injected into the cavity to form the thin wall portion at the thin wall portion forming portion. The thick-walled portion forming portion forms the thick-walled portion, and the thick-walled portion has a substantially similar outer shape of the thick-walled portion, and is substantially sealed and substantially thin-walled. It is manufactured by forming a cavity that does not reach the part.
【００１１】こうして製造した樹脂成形品は、薄肉部と
厚肉部とが一体成形され、しかも厚肉部の内部に空洞が
形成されているため、薄肉部と厚肉部における冷却固化
速度の差は小さくなり、このため内部に不均一な応力が
発生せず、ねじれ等の変形が小さくなる。また厚肉部の
外表面側にひけが発生せず、これにより所定の正確な形
状を保った厚肉部を有する樹脂成形品が得られ、取付性
が良好になるとともに、優れた外観が得られる。In the resin molded product thus manufactured, the thin wall portion and the thick wall portion are integrally molded, and the hollow portion is formed inside the thick wall portion. Therefore, the difference in the cooling solidification rate between the thin wall portion and the thick wall portion is large. Becomes smaller, so that non-uniform stress does not occur inside and deformation such as twisting becomes small. In addition, sink marks do not occur on the outer surface side of the thick-walled part, which makes it possible to obtain a resin-molded product having a thick-walled part that maintains a predetermined accurate shape, which improves the mountability and provides an excellent appearance. To be
【００１２】[0012]
【実施例】以下、本発明を図面の実施例により説明す
る。図１は実施例の樹脂成形品を示す図８の下面図、図
２（ａ）、（ｂ）、（ｃ）はそれぞれ図１のＡ−Ａ断面
図、Ｂ−Ｂ断面図、Ｃ−Ｃ断面図であり、図８および図
９と同一符号は同一または相当部分を示す。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments of the drawings. FIG. 1 is a bottom view of FIG. 8 showing a resin molded product of the embodiment, and FIGS. 2 (a), 2 (b), and 2 (c) are cross-sectional views taken along the line AA, the line BB, and the line C-C of FIG. 1, respectively. It is a sectional view, and the same reference numerals as those in FIGS. 8 and 9 denote the same or corresponding portions.
【００１３】図において、樹脂成形品１は車両のスポイ
ラとして用いられる長尺の成形品で、従来のものと同様
に外表面側に意匠部２が形成され、内部空間３を囲むよ
うに取付部４が全周から裏面側に伸び、内部空間３は裏
面側に開口している。そして意匠部２は主としてほぼ同
一の厚さｔ1、ｔ2の平板状の薄肉部５からなり、取付部
４は薄肉部５の厚さより厚い厚さＴ1、Ｔ2の厚肉部６か
らなり、一体成形されている。薄肉部５の厚さは３〜
３．５ｍｍ以下が好ましい。厚肉部６の内部には、厚肉
部６の長手方向に沿って空洞１１が形成されている。空
洞１１は厚肉部５の外形とほぼ相似的縮小形となってお
り、実質的に密閉で、薄肉部５には実質的に及んでいな
い。In the figure, a resin molded product 1 is a long molded product used as a spoiler for a vehicle, and like the conventional one, a design part 2 is formed on the outer surface side, and a mounting part is provided so as to surround an internal space 3. 4 extends from the entire circumference to the back surface side, and the internal space 3 is open to the back surface side. The design portion 2 is mainly composed of a flat plate-shaped thin portion 5 having substantially the same thickness t 1 and t 2 , and the mounting portion 4 is formed from a thick portion 6 having a thickness T 1 or T 2 larger than that of the thin portion 5. And is integrally molded. The thin portion 5 has a thickness of 3 to
It is preferably 3.5 mm or less. Inside the thick portion 6, a cavity 11 is formed along the longitudinal direction of the thick portion 6. The cavity 11 has a reduced shape that is substantially similar to the outer shape of the thick portion 5, is substantially sealed, and does not substantially extend to the thin portion 5.
【００１４】上記の薄肉部５と厚肉部６の厚さはＴ1、
Ｔ2＞ｔ1、ｔ2となっており、薄肉部５を薄くして軽量
化が計られ、厚肉部６を厚くして取付強度を大きくして
いる。そして厚肉部６は外形の厚さは厚くなっている
が、内部に空洞１１が形成されているため、空洞１１の
周囲の壁となる厚肉部６の周壁１２の厚さＴは空洞１１
の周囲の壁の厚さとほぼ同じ厚さになっている。The thickness of the thin portion 5 and the thick portion 6 is T 1 ,
Since T 2 > t 1 and t 2 , the thin portion 5 is made thin to reduce the weight, and the thick portion 6 is made thick to increase the mounting strength. The outer thickness of the thick portion 6 is thicker, but since the cavity 11 is formed inside, the thickness T of the peripheral wall 12 of the thick portion 6 which is the wall around the cavity 11 is the cavity 11.
It has almost the same thickness as the surrounding wall.
【００１５】１３は通気孔であり、空洞１１と連絡する
ように厚肉部６の先端、すなわち取付部４の外面である
裏面側に形成され、通気路１４と連結している。１５は
断面Ｌ字状の取付具支持部であって、取付孔１６にクリ
ップ等の取付具９を装着して被取付部８に取付けるよう
になっている。取付具支持部１５と意匠部２との間には
すき間１７が形成されている。１８は成形品１を射出成
形型から外すときの成形品移動防止用突起である。Reference numeral 13 denotes a ventilation hole, which is formed at the tip of the thick portion 6, that is, on the back surface which is the outer surface of the mounting portion 4 so as to communicate with the cavity 11, and is connected to the ventilation passage 14. Reference numeral 15 denotes a fixture support portion having an L-shaped cross section, and the fixture 9 such as a clip is attached to the attachment hole 16 so as to be attached to the attachment portion 8. A gap 17 is formed between the fixture support portion 15 and the design portion 2. Reference numeral 18 is a protrusion for preventing movement of the molded product when the molded product 1 is removed from the injection mold.
【００１６】図３は射出成形型の断面図、図４はコア型
の平面図、図５は成形品の一部の斜視図、図６は使用状
態を示す一部の断面図、図７は射出成形のタイミング図
である。FIG. 3 is a sectional view of the injection molding die, FIG. 4 is a plan view of the core die, FIG. 5 is a perspective view of a part of the molded product, FIG. 6 is a partial sectional view showing a use state, and FIG. It is a timing chart of injection molding.
【００１７】２１は射出成形型であって、キャビティ型
２２およびコア型２３間にキャビティ２４が形成されて
いる。キャビティ２４は薄肉部５に対応するすき間と形
状の薄肉部形成部２５と、前記すき間よりも大きい厚肉
部６に対応するすき間と形状の厚肉部形成部２６とから
形成されている。２７はゲートであって、片側の厚肉部
形成部２６の中央に開口するようにコア型２３に設けら
れ、スプル２８およびランナ２９に連結されている。３
０はコールドスラグである。Reference numeral 21 is an injection mold, and a cavity 24 is formed between a cavity mold 22 and a core mold 23. The cavity 24 is formed of a thin portion forming portion 25 having a gap and a shape corresponding to the thin portion 5, and a thick portion forming portion 26 having a gap and a shape corresponding to the thick portion 6 larger than the gap. Reference numeral 27 denotes a gate, which is provided on the core mold 23 so as to open at the center of the thick portion forming portion 26 on one side, and is connected to the sprue 28 and the runner 29. Three
0 is cold slag.
【００１８】両側の厚肉部形成部２６のゲート２７に対
向する部分のコア型２３には凹部３１が形成され、その
中心部にはガス注入口３２が開口している。また凹部３
１付近のコア型２３には通気路形成部３３が形成されて
いる。ガス注入口３２はガス注入管３４から逆止弁３５
を介してガス注入機３６に連絡している。３７はガスボ
ンベ、３８はガスベント、３９は開放弁であり、両側に
設けられ、それぞれ独立にガス圧、ガス流量、ガス注入
タイミング等を制御できるようにされているが、左側は
図示が省略されている。射出成形型２１には取付具支持
部１５を形成するためにスライドコア型が設けられてい
るが、図示は省略されている。A recess 31 is formed in the core mold 23 at a portion of the thick portion forming portions 26 on both sides facing the gate 27, and a gas inlet 32 is opened at the center thereof. In addition, the concave portion 3
An air passage forming portion 33 is formed in the core mold 23 near 1. The gas inlet 32 is connected to the check valve 35 from the gas inlet pipe 34.
To the gas injecting device 36 via. Reference numeral 37 is a gas cylinder, 38 is a gas vent, and 39 is an open valve, which are provided on both sides and can independently control the gas pressure, the gas flow rate, the gas injection timing, etc., but the left side is not shown. There is. The injection mold 21 is provided with a slide core mold for forming the fixture support portion 15, but is not shown.
【００１９】樹脂成形品１の製造方法は、図７のタイミ
ング図に従って行われる。まず射出成形型２１を型締め
し、射出成形機の射出ノズル（図示せず）から溶融した
液状の樹脂４１を供給し、ランナ２９、スプル２８を直
通してゲート２７からキャビティ２４に射出する。この
間ガス注入機３６はＯＦＦの状態でありガスベント３８
は開の状態である。The method of manufacturing the resin molded product 1 is performed according to the timing chart of FIG. First, the injection mold 21 is clamped, the molten liquid resin 41 is supplied from an injection nozzle (not shown) of the injection molding machine, and the runner 29 and the sprue 28 are directly passed through and injected into the cavity 24 from the gate 27. During this time, the gas injector 36 is off and the gas vent 38
Is open.
【００２０】キャビティ２４に射出された樹脂４１は、
図４のａからｂに示すようにキャビティ２４内に充填さ
れていく。そして樹脂４１がガス注入口３２を覆い、好
ましくはキャビティ２４の約７０〜８０％充填された時
点、すなわち図４のほぼｂの位置まで充填され、図面上
左右端部側のキャビティ２４には未だ樹脂４１が充填さ
れず、キャビティ２４内に未た空間が残っている時点
で、開放弁３９を閉じてガスベント３８を大気と遮へい
し、ガス注入機３６を駆動し、ガス注入管３４を通して
ガス注入口３２からキャビティ２４に圧縮した窒素ガス
等のガス４２を注入する。この際、樹脂４１はゲート２
７から引き続き射出し続けるのが好ましい。The resin 41 injected into the cavity 24 is
The cavity 24 is filled as shown in FIGS. Then, the resin 41 covers the gas inlet 32 and is preferably filled up to about 70 to 80% of the cavity 24, that is, up to the position of approximately b in FIG. 4, and the cavity 24 on the left and right end portions side in the drawing is still filled. At the time when the resin 41 is not filled and there is still a space in the cavity 24, the open valve 39 is closed to shield the gas vent 38 from the atmosphere, drive the gas injector 36, and inject the gas through the gas injection pipe 34. A gas 42 such as compressed nitrogen gas is injected into the cavity 24 from the inlet 32. At this time, the resin 41 is applied to the gate 2
It is preferable to continue injection from No. 7.
【００２１】注入されたガス４２は凹部３１の周壁に樹
脂４１を貼付けた状態で凹部３１の中心部を通ってキャ
ビティ２４に入る。キャビティ２４に入ったガス４２は
まず厚肉部形成部２６内の樹脂４１内に小さな空洞を作
り、引き続きゲート２７から供給される樹脂の流動と、
引き続き供給されるガス４２、およびガスの膨張力によ
って、最も流動抵抗の少ない厚肉部形成部２６内を空洞
１１を作りながら、図４のｃに示すように樹脂が未だ充
填されていない側に向けて進む。これにより樹脂４１は
キャビティ２４内に押広げられた状態で厚肉部形成部２
６の周壁および薄肉部形成部２５の全域に充填される。
こうして薄肉部５および厚肉部６が形成されるととも
に、厚肉部６内に空洞１１が形成される。空洞１１の内
壁は厚肉部６の長手方向に連続して、空洞は薄肉部５と
の境界部近くにとどまり、薄肉部５には実質的に及んで
いない状態で形成される。The injected gas 42 enters the cavity 24 through the center of the recess 31 with the resin 41 attached to the peripheral wall of the recess 31. The gas 42 that has entered the cavity 24 first creates a small cavity in the resin 41 in the thick portion forming portion 26, and then the flow of the resin supplied from the gate 27,
While the cavity 11 is formed in the thick-walled portion forming portion 26 having the smallest flow resistance by the gas 42 continuously supplied and the expansion force of the gas, the resin is not filled with the resin as shown in FIG. 4C. Proceed towards. As a result, the resin 41 is spread in the cavity 24 and the thick portion forming portion 2
The entire area of the peripheral wall 6 and the thin portion forming portion 25 is filled.
Thus, the thin portion 5 and the thick portion 6 are formed, and the cavity 11 is formed in the thick portion 6. The inner wall of the cavity 11 is continuous in the longitudinal direction of the thick portion 6, the cavity remains near the boundary with the thin portion 5, and is formed in a state where it does not substantially extend to the thin portion 5.
【００２２】ガス４２の注入は樹脂４１の射出より遅延
して行い、ガス４２の注入後しばらくして樹脂の射出を
停止して冷却に入るが、ガス注入はさらに継続して所定
のガス圧力による保圧状態を維持する。そして保圧、冷
却の終了により、ガス注入機３６を停止してガスベント
３８を開としガス４２を排出し、空洞１１内の圧力を大
気圧に戻した後に型開きして成形品４３を取出す。移動
防止用突起１８は型開き時のスライドコアの移動時に成
形品４３が移動するのを防止する。The injection of the gas 42 is delayed from the injection of the resin 41, and after a while after the injection of the gas 42, the injection of the resin is stopped and cooling is started, but the gas injection is further continued at a predetermined gas pressure. Maintain the holding pressure. When the pressure holding and cooling are completed, the gas injector 36 is stopped, the gas vent 38 is opened to discharge the gas 42, the pressure inside the cavity 11 is returned to atmospheric pressure, and then the mold is opened to take out the molded product 43. The movement preventing projection 18 prevents the molded product 43 from moving when the slide core moves when the mold is opened.
【００２３】取出された成形品４３は樹脂成形品１に対
応した形状を有するが、図５に示すように凹部３１に対
応する凸部４４および環状凹部４５を有し、凸部４４に
ガス注入跡として通気孔１３が形成されている。また通
気路形成部３３によって通気路１４が形成されている。
そこで凸部４４を折って円形凹部４６を形成すると、円
形凹部４６に通気孔１３が開口する。このようにして得
られた成形品には、次いで塗装などにより、表面に所望
の色の着色層を形成することもできる。The molded product 43 taken out has a shape corresponding to the resin molded product 1, but as shown in FIG. 5, it has a convex portion 44 corresponding to the concave portion 31 and an annular concave portion 45, and gas is injected into the convex portion 44. Vent holes 13 are formed as traces. Further, the ventilation passage 14 is formed by the ventilation passage forming portion 33.
Therefore, when the convex portion 44 is folded to form the circular concave portion 46, the ventilation hole 13 is opened in the circular concave portion 46. A colored layer of a desired color can then be formed on the surface of the molded product thus obtained by coating or the like.
【００２４】こうして製造された樹脂成形品１は図６に
示すように、粘着剤層７ａ、７ｂを有する両面粘着テー
プのような固着手段７を取付部４に固着し、車体パネル
等の被取付部８に固着する。これと同時に図２（ｂ）に
示すように、クリップ等の取付具９を取付具支持部１５
の取付孔１６に取付けて、被取付部８の取付孔８ａに取
付け、２通りの固着手段により固着する。As shown in FIG. 6, the resin molded product 1 manufactured in this manner has a fixing means 7 such as a double-sided adhesive tape having adhesive layers 7a and 7b fixed to the mounting portion 4 to be mounted on a vehicle body panel or the like. Stick to the part 8. At the same time, as shown in FIG. 2B, the attachment 9 such as a clip is attached to the attachment support portion 15.
To the mounting hole 8a of the mounted portion 8 and fixed by two kinds of fixing means.
【００２５】固着状態においては、空洞１１は通気孔１
３および通気路１４を通して大気に通じているため、温
度差により内部の空気が膨張または収縮しても、樹脂成
形品１の変形は生じない。In the fixed state, the cavity 11 has the vent hole 1
3 communicates with the atmosphere through the air passage 14 and the air passage 14, so that the resin molded product 1 is not deformed even if the internal air expands or contracts due to a temperature difference.
【００２６】上記の樹脂成形品１は、薄肉部５と厚肉部
６が一体成形されており、厚肉部６の内部に空洞１１が
形成されているため、射出成形時における薄肉部５と厚
肉部６の冷却固化速度の差は小さくなり、このため内部
に不均一な応力が発生せず、ねじれ等の変形が小さくな
る。また厚肉部６の外表面側にひけが発生せず、これに
より所定の正確な形状を保った厚肉部（取付部）を有す
る樹脂成形品１が得られ、取付性が良好となるととも
に、優れた外観が得られる。In the resin molded product 1 described above, the thin portion 5 and the thick portion 6 are integrally molded, and the cavity 11 is formed inside the thick portion 6, so that the thin portion 5 and the thin portion 5 at the time of injection molding are formed. The difference in the cooling and solidifying speed of the thick portion 6 becomes small, so that non-uniform stress does not occur inside and the deformation such as twisting becomes small. In addition, the sink mark does not occur on the outer surface side of the thick wall portion 6, whereby a resin molded product 1 having a thick wall portion (mounting portion) maintaining a predetermined accurate shape can be obtained, and the mountability becomes good and , An excellent appearance is obtained.
【００２７】上記実施例のように射出成形型２１のゲー
ト２７に対向する位置にガス注入口３２を開口させる
と、射出された樹脂４１が両側に分れる部分であるた
め、ガス４２の注入が容易かつ均一になるが、場合によ
っては他の位置でもよい。また凹部３１にガス注入口３
２を開口させると、樹脂圧が直接かからず、しかも樹脂
が凹部で静止して注入口３２の周辺部が他の部分よりも
相対的に速く固化するためガス４２の注入は容易になる
が、場合によっては他の場所でもよい。When the gas injection port 32 is opened at a position facing the gate 27 of the injection mold 21 as in the above embodiment, the injected resin 41 is divided into both sides, so that the gas 42 is injected. It is easy and uniform, but other positions may be possible. Further, the gas injection port 3 is provided in the recess 31.
When 2 is opened, the resin pressure is not directly applied, and further, the resin stands still in the concave portion and the peripheral portion of the injection port 32 is solidified relatively faster than other portions, so that the gas 42 can be injected easily. , Depending on the case, it may be another place.
【００２８】なお上記実施例では、空洞１１を形成した
厚肉部６を固着する固着手段７として両面粘着テープの
例を示したが、取付ボルトその他の固着手段であっても
よい。 また上記実施例は車両用のスポイラに使用する
樹脂成形品に関するものであったが、ボデー・サイドモ
ール、ホイールオープニングトリム、フイニッシャー等
の他の用途の樹脂成形品にも応用でき、それに伴って形
状、構造等は変更可能である。In the above embodiment, the example of the double-sided adhesive tape is shown as the fixing means 7 for fixing the thick portion 6 in which the cavity 11 is formed, but a fixing bolt or other fixing means may be used. Further, although the above-mentioned embodiment relates to the resin molded product used for the vehicle spoiler, it can be applied to the resin molded products for other uses such as the body / side molding, the wheel opening trim, the finisher, and the like. , The structure, etc. can be changed.
【００２９】[0029]
【発明の効果】本発明の樹脂成形品は、薄肉部と厚肉部
が一体成形され、かつ厚肉部に空洞が形成されているた
め、ひけやねじれ等の変形は少なくなり、取付性および
外観に優れた樹脂成形品が得られる。The resin molded product of the present invention has a thin portion and a thick portion integrally formed, and has a cavity formed in the thick portion, so that deformation such as sink marks and twists is reduced, and the mounting property and A resin molded product having an excellent appearance can be obtained.
【００３０】本発明の樹脂成形品の製造方法は、薄肉部
形成部および厚肉部形成部からなるキャビティ、および
厚肉部形成部にガス注入口を有する射出成形型を用い、
樹脂がガス注入口を覆った後にガスを注入するため、薄
肉部形成部で薄肉部を形成し、厚肉部形成部で厚肉部を
形成するとともに、厚肉部に空洞を形成することがで
き、上記の樹脂成形品を効率よく製造することができ
る。The method for producing a resin molded product of the present invention uses an injection molding die having a cavity formed of a thin portion forming portion and a thick portion forming portion, and a gas injection port in the thick portion forming portion,
Since the gas is injected after the resin covers the gas inlet, it is possible to form a thin portion in the thin portion forming portion, form a thick portion in the thick portion forming portion, and form a cavity in the thick portion. Therefore, the resin molded product can be efficiently manufactured.
【図１】実施例の樹脂成形品を示す図８の下面図であ
る。FIG. 1 is a bottom view of FIG. 8 showing a resin molded product of an example.
【図２】（ａ）は図１のＡ−Ａ断面図、（ｂ）はＢ−Ｂ
断面図、（ｃ）はＣ−Ｃ断面図である。2A is a sectional view taken along line AA of FIG. 1, and FIG. 2B is taken along line BB.
Sectional drawing, (c) is CC sectional drawing.
【図３】射出成形型の断面図である。FIG. 3 is a cross-sectional view of an injection mold.
【図４】コア型の平面図である。FIG. 4 is a plan view of a core type.
【図５】成形品の一部の斜視図である。FIG. 5 is a perspective view of a part of the molded product.
【図６】成形品の使用状態を示す一部の断面図である。FIG. 6 is a partial cross-sectional view showing a usage state of a molded product.
【図７】射出成形のタイミング図である。FIG. 7 is a timing chart of injection molding.
【図８】樹脂成形品の斜視図である。FIG. 8 is a perspective view of a resin molded product.
【図９】樹脂成形品を示す図８のＸ−Ｘ断面図である。9 is a sectional view taken along line XX of FIG. 8 showing a resin molded product.
１ 樹脂成形品 ２ 意匠部 ３ 内部空間 ４ 取付部 ５ 薄肉部 ６ 厚肉部 ７ 固着手段 ８ 被取付部 ９ 取付具 １１ 空洞 １２ 周壁 １３ 通気孔 １４ 通気路 １５ 取付具支持部 ２１ 射出成形型 ２２ キャビティ型 ２３ コア型 ２４ キャビティ ２５ 薄肉部形成部 ２６ 厚肉部形成部 ２７ ゲート ２８ スプル ２９ ランナ ３１ 凹部 ３２ ガス注入口 ３３ 通気路形成部 ３６ ガス注入機 ３７ ガスボンベ ４１ 樹脂 ４２ ガス DESCRIPTION OF SYMBOLS 1 Resin molded product 2 Design part 3 Internal space 4 Mounting part 5 Thin part 6 Thick part 7 Fixing means 8 Attached part 9 Mounting tool 11 Cavity 12 Circumferential wall 13 Vent hole 14 Ventilation path 15 Mounting tool support part 21 Injection molding type 22 Cavity type 23 Core type 24 Cavity 25 Thin portion forming portion 26 Thick portion forming portion 27 Gate 28 Spru 29 Runner 31 Recessed portion 32 Gas injection port 33 Ventilation passage formation portion 36 Gas injector 37 Gas cylinder 41 Resin 42 gas
Claims (6)
薄肉部の厚さよりも厚い厚さの厚肉部が一体成形され、
前記厚肉部には内部に実質的に密閉された空洞が形成さ
れており、この空洞は厚肉部の外形のほぼ相似的縮小形
に形成され、かつ薄肉部には実質的に及んでいないこと
を特徴とする樹脂成形品。1. A plate-shaped thin portion having substantially the same thickness and a thick portion thicker than the thin portion are integrally molded,
A cavity that is substantially closed inside is formed in the thick portion, and the cavity is formed to have a shape similar to the outer shape of the thick portion, and does not substantially extend to the thin portion. A resin molded product characterized by the above.
厚肉部が一体成形され、厚肉部に空洞が形成されている
ことを特徴とする請求項１記載の樹脂成形品。2. The resin molded product according to claim 1, wherein a thin portion serving as a design portion and a thick portion serving as an attachment portion are integrally molded, and a cavity is formed in the thick portion.
ることを特徴とする請求項１または２記載の樹脂成形
品。3. The resin molded product according to claim 1 or 2, wherein the thick portion has an air passage connected to the cavity.
形成部と、前記すき間よりも大きいすき間の厚肉部形成
部とからなるキャビティ、および前記厚肉部形成部に圧
縮ガス注入口を有する射出成形型を用い、 キャビティに溶融樹脂を射出し、射出した樹脂がガス注
入口を覆った後で、樹脂がキャビティ内を満たす前に圧
縮ガスを注入して、キャビティ内の樹脂を圧縮ガスとと
もに流動させることにより、 薄肉部形成部で薄肉部を形成し、厚肉部形成部で厚肉部
を形成するとともに、厚肉部の内部に、厚肉部の外形の
ほぼ相似的縮小形を有し、実質的に密閉され、かつ実質
的に薄肉部に及んでいない空洞を形成することを特徴と
する樹脂成形品の製造方法。4. A cavity formed by a thin-walled portion forming portion having substantially the same gap in a planar shape and a thick-walled portion forming portion having a gap larger than the gap, and a compressed gas injection port in the thick-walled portion forming portion. Using the injection mold that has, the molten resin is injected into the cavity, the compressed resin is injected after the injected resin covers the gas injection port and before the resin fills the cavity, and the resin in the cavity is compressed gas. By flowing the fluid with the thin-walled portion forming portion, the thin-walled portion forming portion forms the thin-walled portion, and the thick-walled portion forming portion forms the thick-walled portion. A method for producing a resin molded article, which comprises forming a cavity which is substantially sealed and which does not substantially extend to a thin portion.
する位置に形成することを特徴とする請求項４記載の樹
脂成形品の製造方法。5. The method for producing a resin molded product according to claim 4, wherein the gas injection port is formed at a position facing the gate of the injection mold.
ることを特徴とする請求項４または５記載の樹脂成形品
の製造方法。6. The method for producing a resin molded product according to claim 4, wherein the gas injection port is formed in a recess of the injection mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5129771A JP2743770B2 (en) | 1993-05-31 | 1993-05-31 | Resin molded product having cavity inside and manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5129771A JP2743770B2 (en) | 1993-05-31 | 1993-05-31 | Resin molded product having cavity inside and manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06339975A true JPH06339975A (en) | 1994-12-13 |
| JP2743770B2 JP2743770B2 (en) | 1998-04-22 |
Family
ID=15017809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5129771A Expired - Fee Related JP2743770B2 (en) | 1993-05-31 | 1993-05-31 | Resin molded product having cavity inside and manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2743770B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102459489A (en) * | 2009-04-15 | 2012-05-16 | 株式会社普利司通 | Adhesive composition, bonding method, laminate and tire |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03218811A (en) * | 1990-01-25 | 1991-09-26 | Asahi Chem Ind Co Ltd | Injection molded body |
| JPH0478510A (en) * | 1990-07-20 | 1992-03-12 | Honda Motor Co Ltd | Production of hollow resin product |
| JPH04103317A (en) * | 1990-08-23 | 1992-04-06 | Nifco Inc | Rotating tank device of fuel for automobile |
| JPH04310712A (en) * | 1991-04-09 | 1992-11-02 | Sekisui Chem Co Ltd | Handle and molding thereof |
| JPH05118170A (en) * | 1991-05-08 | 1993-05-14 | Mitsubishi Gas Chem Co Inc | Handle type molding and its injection molding method plus metal mold |
| JPH05245879A (en) * | 1990-03-14 | 1993-09-24 | Nitrojection Corp | Small nozzle for injection molding small mold, injection molding device, and gas-assisted injection molding |
| JPH06312447A (en) * | 1993-04-28 | 1994-11-08 | Idemitsu Petrochem Co Ltd | Gas injection molding method, mold thereof and molded product |
-
1993
- 1993-05-31 JP JP5129771A patent/JP2743770B2/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03218811A (en) * | 1990-01-25 | 1991-09-26 | Asahi Chem Ind Co Ltd | Injection molded body |
| JPH05245879A (en) * | 1990-03-14 | 1993-09-24 | Nitrojection Corp | Small nozzle for injection molding small mold, injection molding device, and gas-assisted injection molding |
| JPH0478510A (en) * | 1990-07-20 | 1992-03-12 | Honda Motor Co Ltd | Production of hollow resin product |
| JPH04103317A (en) * | 1990-08-23 | 1992-04-06 | Nifco Inc | Rotating tank device of fuel for automobile |
| JPH04310712A (en) * | 1991-04-09 | 1992-11-02 | Sekisui Chem Co Ltd | Handle and molding thereof |
| JPH05118170A (en) * | 1991-05-08 | 1993-05-14 | Mitsubishi Gas Chem Co Inc | Handle type molding and its injection molding method plus metal mold |
| JPH06312447A (en) * | 1993-04-28 | 1994-11-08 | Idemitsu Petrochem Co Ltd | Gas injection molding method, mold thereof and molded product |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102459489A (en) * | 2009-04-15 | 2012-05-16 | 株式会社普利司通 | Adhesive composition, bonding method, laminate and tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2743770B2 (en) | 1998-04-22 |
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