JP2009149044A

JP2009149044A - Injection mold structure having undercut on inner surface and its forming method

Info

Publication number: JP2009149044A
Application number: JP2007341831A
Authority: JP
Inventors: Takeshi Takahashi; 高橋　　健; Jo Suzuki; 城鈴木
Original assignee: TAMMY MACHINERY CO Ltd
Current assignee: TAMMY MACHINERY CO Ltd
Priority date: 2007-12-20
Filing date: 2007-12-20
Publication date: 2009-07-09

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic molded product in which a pipe inserting stopper forming a large difference in level to cause a large head loss (energy loss) in domestic water supply is improved, the inside of an inner surface is rounded, and the difference in level is made low, and to provide a mold for the same. <P>SOLUTION: A pipe inserting stopper part on the whole periphery of the inside of the inner surface of an elbow is rounded and the stopper is structured to have the difference in level of the stopper made remarkably low only on the half of the outside of the inner surface. As a molding method, an injection molding machine is used for injection, a sleeve is pushed out after cooling and the solidification are finished, divided cores 6 are pushed out by a proper distance simultaneously with the pushing out of the sleeve and the undercut R is rotated and moved outside to be released by jetting air through a gap between the sleeve and the core to push the rounded part of the inside of the inner surface of the molded product in the rotating direction and further to push the molded product in the outside direction N with air discharged from an inclined hole 9-7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

射出金型で内面にアンダカットＲ（３−２）のある成形品で、そのアンダカットをはずすのは一般的に困難な場合が多い、今回は例として給水管のエルボ−（図１）について説明する。このようなエルボ−（図１）（１）が家庭用給水の９０°方向変換の通路として多く用いられている、この形状は単に２方向（Ｆ、Ｐの２方向）にコア−５の横移動とスリ−ブで押す金型構造で非常に簡単である、しかし（図１）に示す如く内面には給水管挿入の当たり面として高い段差と（３−１）と、また９０°エッジ（直角エッジ）となり、従って給水のための水の流れにおいて大きなヘッドロス（エネルギ−損失）を起こしている。これを解消するために考案された方法で内面内側にＲをつけ、且つ段差を低くするプラスチックス成形品及びその金型に関する。 An injection mold with an undercut R (3-2) on the inner surface, and it is generally difficult to remove the undercut. This time, as an example, the elbow of the water supply pipe (Fig. 1) explain. Such elbows (Fig. 1) (1) are often used as passages for 90 ° direction conversion of domestic water supply. This shape is simply in two directions (two directions F and P) and the side of the core-5. It is very simple with a mold structure that moves and pushes with a sleeve. However, as shown in FIG. 1, the inner surface has a high step (3-1) as a contact surface for inserting a water supply pipe, and a 90 ° edge ( Right-angled edge), and thus a large head loss (energy loss) is caused in the flow of water for water supply. The present invention relates to a plastics molded product and a mold thereof in which an inner surface is rounded by a method devised to solve this problem, and a step is lowered.

Conventional injection mold shape

エネルギ−を消費するものは全て省エネが要求される現在、今回取り上げた給水関係のエルボ−（図１）（１）は省エネには程遠い形状といえる。水の通り道が内面外側はＲであるが内側は挿入されるパイプストパ−部（３−１）が金型のコア−の突合せの関係でエッジ（３−１）形状になっていることである、このエッジにより計算値であるが約０．０７８ｍ／個のヘッドロス（エネルギ−損出）が起こる、これが１軒あたり約１０個以上使用されているので、もしこれを（図１）（２）のように内面内側Ｒ（３−２）に変換すれば約０．０３４ｍ／個のヘッドロスとなって小さくなる。現在家は毎年約１２０〜１３０万軒建設されているので、その差を１２０万軒１日で計算すると約１３０万ｋｗ・ｄａｙとなって莫大な省エネとなる。径が大きければ排水管（直径７５ｍｍ以上）のようにコア−をラックギヤ−やモ−タ−で回転して成形品を作ることは既に行われている。しかし家庭給水管は内径１３ｍｍ（ＶＰ１３）で小さく、しかも８〜１２個の多数個取り金型ではそのようなことは出来ない。その理由はそのＲ部分がアンダ−カット（３−２）をはづすことが困難であるからである、そこで研究考案されたのが本案であり、従来の金型を改造するだけで容易に省エネの効果、たとえ新型を起こしても効果／費用の面では最高といえる事が出来る（太陽光、地熱、波力等との比較において）。
公開実用新案公報（Ｕ）実開平６−２３７２４ All energy consuming items are required to save energy, and the water supply elbows (Fig. 1) (1) taken up this time are far from energy saving. The water path is R on the inner surface outer side, but the inner side is that the pipe stopper portion (3-1) to be inserted has an edge (3-1) shape due to the butting of the core of the mold. This edge causes a calculated value of about 0.078 m / piece of head loss (energy loss). Since this is used about 10 or more per house, if this (Fig. 1) (2) Thus, if converted into the inner surface inner side R (3-2), the head loss is reduced to about 0.034 m / piece. Currently, about 1.2 to 1.3 million houses are built every year, and if the difference is calculated in 1.2 million houses per day, it is about 1.3 million kw · day, which is a huge energy saving. If the diameter is large, it has already been done to make a molded product by rotating the core with a rack gear or motor like a drain pipe (diameter 75 mm or more). However, the domestic water supply pipe has a small inner diameter of 13 mm (VP13), and such a multi-cavity mold with 8 to 12 cannot do that. The reason is that it is difficult for the R portion to cause an undercut (3-2). The present invention was devised there, and it can be easily achieved by simply remodeling the conventional mold. It can be said that the energy saving effect, even if a new model is started, is the best in terms of effect / cost (in comparison with sunlight, geothermal, wave power, etc.).
Public Utility Model Gazette (U) 6-28324

この方法は射出金型を用いて曲がり管を成形、これをＲのついた金型に入れ替え内面の温度調整によって内面内側にＲを形成させるもので、最初よりＲ（３−２）の付いた金型で成形し、そのＲをはづすのとは基本的に異なっている、しかもこの方法は成形時間が長くなり、２段回成形のためコスト高につながる。径の大きなものは問題ないが径１３ｍｍのような小口径品では非常に困難と思われる。
審査未請求
公開特許公報（Ａ）特開平５−１６１８６In this method, a bent tube is formed using an injection mold, this is replaced with a mold with R, and R is formed on the inner surface by adjusting the temperature of the inner surface, and R (3-2) is attached from the beginning. This method is basically different from molding with a mold and peeling R, and this method requires a long molding time and leads to high costs due to two-stage molding. There is no problem with a large diameter, but it seems very difficult for a small diameter product such as 13 mm in diameter.
Examination unclaimed published patent publication (A) Japanese Patent Laid-Open No. 5-16186

フュ−ジブルコア−（規定してないが恐らく合成ゴム、シリコンゴム等と考えられる）により内面Ｒをつける方法であるが、エルボ−成形品材質は無可塑ポリ塩化ビニ−ルである、この樹脂の成形温度は１８０°Ｃでコア−の材質では耐熱性が低く金型としての役目を果たさない。
またこの方法は上記実用新案同様、誰でも直ぐに考えつく方法で、小生も、今から十数年前気づき実施したが数十ショットでゴムコア−が耐熱性が低い関係で、ぼろぼろになり実用に耐えなかった経験を持っている、本件も同様なことで審査未請求になっているものと思われる。This is a method of attaching the inner surface R with a fusible core (which is not specified but is probably considered to be synthetic rubber, silicone rubber, etc.), but the elbow is made of unplasticized polyvinyl chloride. The molding temperature is 180 ° C., and the core material has low heat resistance and does not serve as a mold.
Also, this method is a method that anyone can think of immediately like the above-mentioned utility model, and elementary school students have noticed it for dozens of years ago, but because the heat resistance of the rubber core is low in several tens of shots, it becomes crumbly and unbearable This case seems to have been unclaimed for the same reason.

（１）現在使用されている（図１）（１）エルボ−（ＪＩＳ規定）を示し、パイプ挿入ストッパ−部分（３−１）は金型の関係で９０°エッジとなっている、この形状では家庭用給水の流れを阻害し大きなヘッドロス（エネルギ−損失）を引き起こしていることの解消。
（２）各種ゴム等のフュ−ジブルコア−では内面の外内側にＲをつけることは出来るが成形の際耐熱問題で実用に耐えない。
（３）金属であれば問題ないがフュ−ジブル性がない。
（４）従って上記（３）項の金属で如何なる構造にしてアンダ−カットをはずすかである。(1) Currently used (Fig. 1) (1) Shows elbow (JIS regulation), pipe insertion stopper part (3-1) is 90 ° edge due to the mold, this shape Then, it is solved that obstructs the flow of domestic water supply and causes a big head loss (energy loss).
(2) Various fusible cores such as rubber can be provided with an R on the inner side of the inner surface, but cannot withstand practical use due to heat resistance during molding.
(3) There is no problem if it is a metal, but there is no fusibility.
(4) Therefore, what is the structure of the metal of the above item (3) and how to remove the undercut.

Means to solve the problem

解決する手段として（図１）に示す如く
（１）家庭用給水の流れを妨げるパイプ挿入ストッパ−（３−１）をなくしてＲ（３−２）を形成しストッパ−の段差２を低くし、しかも内面外方半分のみとする。
（２）コア−はフュジブルなものは使用せず、長期使用可能な金族性のものとする。
（３）コア−を分割し内面内側のコア−にＲ（３−２）を形成し水がスム−スに流れるようにする。
（４）Ｒ（３−２）はアンダ−カットとなるため、これをはずす方法を考案する。
以下その詳細を説明する。As a means to solve the problem, as shown in FIG. 1, (1) The pipe insertion stopper (3-1) that obstructs the flow of domestic water supply is eliminated, R (3-2) is formed, and the step 2 of the stopper is lowered. In addition, the inner half is only the outer half.
(2) The core shall not be fusible, but shall be of a metallic nature that can be used for a long time.
(3) Divide the core and form R (3-2) in the inner core to allow water to flow smoothly.
(4) Since R (3-2) is undercut, a method of removing this is devised.
The details will be described below.

（図３）に示す如く溶融原料はスプル−（１０−１）より金型に入りストリッパ−ランナ−（１０−２）を第二スプル−（１０−３）、更にランナ−、ゲ−ト（１０−４）（ほぼ同じ太さ）を通ってキャビテ−（成形品エルボ−）に入り内面内側にＲ（３−２）が形成され、冷却されて取り出されるが、コア−６はアンダ−カット（３−２）を有し、はづさなければ、成形品（エルボ−）は取り出すことは出来ない、そこで考案された事項を説明する。（図４）に示す如く、先ずエルボ−横方向コア−５を傾斜ピン又はエア−シリンダ−等にて抜くと縦方向のコア−６，７との当たり面４の部分はフリ−となりコア−６は下部のスプリング（６−２）により、必要な隙間（６−１）だけ上方に動き成形品との間に隙間（６−１）に相当する隙間が出来る、この状態で（図４）に示されているように押出板に保持されているスリ−ブエジェクタ−ピン８、可動コア−６は一緒に適当な距離だけ上昇させる、固定コア−７コア−押え板２５に固定されているので可動しない、従って成形品は全くフリ−な状態になる。 As shown in FIG. 3, the molten raw material enters the mold from the sprue (10-1) and the stripper runner (10-2) to the second sprue (10-3), and further to the runner and gate ( 10-4) It passes through (substantially the same thickness) and enters the cavities (molded product elbow), R (3-2) is formed on the inner surface, cooled and taken out, but the core-6 is undercut If (3-2) is included and not formed, the molded product (elbow) cannot be taken out. As shown in FIG. 4, first, when the elbow-lateral core 5 is pulled out with an inclined pin or an air cylinder, the contact surface 4 portion with the longitudinal cores 6, 7 becomes free and the core- 6 is moved upward by a necessary gap (6-1) by the lower spring (6-2), and a gap corresponding to the gap (6-1) is formed between the molded product in this state (FIG. 4). The sleeve ejector pin 8 and the movable core 6 held on the extrusion plate are fixed to a fixed core-7 core-presser plate 25 which is raised together by an appropriate distance. It does not move, so the part is completely free.

この状態（図４）でエア−通路（９−１）（９−２）を通り送られてくるエア−通路の隙間（９−３）（エア−は通るが溶融原料は入らない隙間）及びエア−通路（９−４）（９−５）を通り送られてくるエア−孔（９−７）より噴出させて成形品をＧを中心として回転（矢印Ｏ）及び外方（図面では上方向矢印Ｐ））に押出してアンダカットをはづす方法で内面内側にＲのついたエルボ−成形品を得ることが出来るし、落下するので無人自動運転が出来る。
更にエア−又は油圧シリンダ−等を設置し押出されて全くフリ−となった成形品の第２スプル−、ランナ−、又は成形品をＮ方向（実際には下方向）に押すことによってアンダ−カットのはづしは更に確実になる、又自動運転確実性は向上する。
尚省エネのため挿入するパイプ（１５−１）の端面は内面テ−パ−３０°以内に削る（この角度以内の縮小、拡大は無視できると水力学の本に記載されている）、外面エッジは糸面取りとし、当たり面（１５−２）は出来るだけ薄くする（０．５ｍｍ程度）とする。In this state (FIG. 4), a gap (9-3) in the air-passage (9-3) (a gap through which the air passes but does not enter the molten raw material) sent through the air-passages (9-1) and (9-2) and The molded product is rotated about G (arrow O) and outward (upward in the drawing) by ejecting from the air hole (9-7) sent through the air passage (9-4) (9-5). An elbow-shaped product with an R on the inner surface can be obtained by extruding it in the direction arrow P)) and undercutting, and since it falls, unmanned automatic operation is possible.
Further, by installing an air or hydraulic cylinder or the like and pushing the second sprue, runner, or molded product of the molded product, which has been completely freed by being pushed out, under the N direction (actually downward) The cut start is further ensured and the automatic driving reliability is improved.
In addition, the end face of the pipe (15-1) to be inserted is cut within 30 ° of the internal taper (this is stated in the hydrodynamic book that the reduction and enlargement within this angle can be ignored). Is a thread chamfer, and the contact surface (15-2) is as thin as possible (about 0.5 mm).

エルボ−について実際に金型を作り成形実施しアンダ−カットをはづし成形品は自動落下確認と別に装置を作り省エネデ−タ−も得ている。 An elbow is actually made and molded, and undercuts are made, and the molded product is manufactured separately from the automatic drop confirmation, and energy saving data is also obtained.

Industrial applicability

上記のとおり実施確認により、更に分岐管の内面内側にＲをつける改良、家庭内ピプ（ＶＰ１３）、本管パイプ（ＶＰ１００）内面の凹凸をなくし、鏡面光沢のパイプを作り、新設又は改造の家屋１２０万軒に適用すれば計算値であるが１８０万ＫＷ／ｄａｙ以上、石炭火力発電で換算すれば炭酸ガス５５５ｔｏｎ／年以上の効果を得るものである。
省エネの叫ばれる今日規制をかけてでも実施すべき事項と考えています。By confirming the implementation as described above, further improve the R inside of the branch pipe, eliminate unevenness on the inner surface of the home pipe (VP13) and main pipe (VP100), create a mirror-gloss pipe, If applied to 1,200,000 houses, the calculated value is 1.8 million KW / day or more, and if converted by coal-fired power generation, carbon dioxide gas of 555 tons / year or more is obtained.
We believe that this is a matter that should be carried out even today's regulations that call for energy conservation.

各図面は一例としてエルボ−成形品とその成形法をもって示す。（本金型構造は他にも適用可能であるため）
（１）現在使用されているＪＩＳに規定のエルボ−断面図でパイプ挿入ストッパ−（３−１）付き、且つ内面内側全周のものを示す。（２）は改良したものを示し、内面内側Ｒ付き、且つストッパ−は内面外周半分とする。金型可動側断面図を示す。溶融原料の射出後固化状態を示す。金型固定側断面図を示し、溶融原料がキャビテ−に入る通路、及びパ−テイングライン（ＰＬ）（Ａ−Ｂ−Ｃ−Ｄ−Ｅ）を示す。可動側断面図で成形品が押出された状態を示す。また可動側コア−６，７が分割コア−を示し、アンタ−カットＲ部分（３−２）が分割されたコア−６にはりついていることを示す。 Each drawing shows an elbow-molded product and its molding method as an example. (Because this mold structure can be applied elsewhere)
(1) An elbow with a pipe insertion stopper (3-1) is shown in the elbow cross-sectional view defined in JIS currently used, and the inner circumference of the inner surface is shown. (2) shows an improved one, with an inner surface inner radius R, and the stopper is half the inner surface outer periphery. The mold movable side sectional view is shown. The solidified state after injection of the molten raw material is shown. A mold fixed side sectional view is shown, and a passage into which a melted raw material enters a cavity, and a parting line (PL) (ABCDE) are shown. The state by which the molded article was extruded with a movable side sectional view is shown. Further, the movable cores 6 and 7 indicate split cores, and the undercut R portion (3-2) sticks to the split core-6.

Explanation of symbols

１−１．内面内側がＲとなっているキャビテ−（成形品面）断面形状（図１）（２）
１−２．内面内側がＲとなっているキャビテ−（成形品面）正面形状（図３）
１−３．内面内側がＲとなっているキャビテ−（成形品面）側面形状（図３）
２．パイプ挿入ストッパ−の段差（図２）
３−１．現在使用中パイプ挿入ストッパ−段差の形状（図１）（１）
３−２．内面内側のＲ（図１、２）
４．横方向スライドコア−５と垂直コア−６，７との押切り面）（図２）
５．横方向スライドコア−５の形状（図２，４）
６．分割コア−（押出しスリ−ブエジェクタ−ピンと一緒に動く）（図２、４）
６−１．分割コア−６の可動隙間（図２）
６−２．分割コア−６を押上げるスプリング（図２，４）
７．分割コア−（コア−押え板に固定）（図２，４）
９−１．エア−通路孔（図２，４）
９−２．エア−通路溝
９−３．エア−噴出孔
９−４．エア−通路溝（９−２）に繋がるエア−通路孔
９−５．エア−通路孔（９−４）に繋がるエア−通路孔
９−６．エア−通路孔（９−５）のエア−孔栓
９−７．エア−噴出孔
１０−１．第１スプル−（図３）
１０−２．ランナ−（図３）
１０−３．第２スプル−（図３）
１０−４．第２ランナ−、ゲート（図３）
１５−１挿入するパイプ本体（図４）
１５−２挿入するパイプの当たり面
１５−３挿入するパイプの内面テエパ−
２０固定側金型取付板（図３）
２１固定側ランナ−ピン固定板（図３）
２２ランナ−ストリッパ−
２５コア−ピン押え板（図２，４）
２６押出板後板
２７押出板前板
Ａ−Ｂ−Ｃ−Ｄ−Ｅ（図３）パ−テイングライン（ＰＬ）
Ｅ．横方向スライドコア−センタ−
Ｇ−Ｈ．スリ−ブエジェクタ−と成形品との境界線（図２，４）
Ｎ．第２スプル−、ランナ−、成形品等を押す矢印（図２，４）
Ｏ．成形品回転の矢印
Ｐ．成形品を押出す方向の矢印（図２）1-1. Cavitation (molded product surface) cross-sectional shape with R on the inner surface (Fig. 1) (2)
1-2. Cavity (inside of molded product) with R on the inner surface
1-3. Cavity (inside of molded product) side face shape with R on the inner surface (Figure 3)
2. Step in the pipe insertion stopper (Fig. 2)
3-1. Pipe insertion stopper currently in use-Step shape (Fig. 1) (1)
3-2. R on the inner surface (Figs. 1 and 2)
4). (Cut surface of horizontal slide core-5 and vertical core-6, 7) (Fig. 2)
5. Horizontal slide core-5 shape (Figs. 2 and 4)
6). Split core (moves with extruded sleeve ejector pin) (Figs. 2, 4)
6-1. Movable gap of split core-6 (Fig. 2)
6-2. Spring to push up the split core-6 (Figs. 2 and 4)
7). Divided core (core-fixed to the holding plate) (Figs. 2 and 4)
9-1. Air-passage hole (Figs. 2 and 4)
9-2. Air-passage groove 9-3. Air-outlet 9-4. Air-passage hole 9-5 connected to the air-passage groove (9-2). Air-passage hole 9-6 connected to the air-passage hole (9-4). Air-hole plug 9-7 of air-passage hole (9-5). Air-outlet 10-1. First sprue (Fig. 3)
10-2. Runner (Figure 3)
10-3. Second sprue (Fig. 3)
10-4. Second runner, gate (Figure 3)
15-1 Pipe body to be inserted (Fig. 4)
15-2 Contact surface of the pipe to be inserted 15-3 Inner surface taper of the pipe to be inserted
20 Fixed mold mounting plate (Fig. 3)
21 Fixed runner pin fixing plate (Fig. 3)
22 Runner Stripper
25 Core-pin holding plate (Figs. 2 and 4)
26 Extrusion plate rear plate 27 Extrusion plate front plate ABCDE (Fig. 3) Parting line (PL)
E. Horizontal slide core-center
GH. Boundary line between sleeve ejector and molded product (Figs. 2 and 4)
N. Arrows that push the second sprue, runner, molded product, etc. (Figs. 2 and 4)
O. Rotation arrow P. Arrow in the direction of extruding the molded product (Fig. 2)

Claims

(Fig. 1) Elbow-Pipe insertion stopper (3-1) on the inner circumference of the inner surface as shown in (1) section (R) (3-2) as shown in (Fig. 1) (2) section, The step 2 of the stopper is very low and has a structure with only the outer half on the inner surface.

As a molding method of the molded article of (Claim 1), an injection molding machine is used for injection, and after the cooling and solidification is completed, the sleeve is extruded, and the core 6 divided simultaneously with the sleeve is suitable as shown in FIG. Extrusion is performed, air is ejected from the gap (9-3) between the rib and the core, the inner part R of the inner surface of the molded product is pushed in the rotational direction O, and further molding is performed with air coming out of the inclined hole (9-7) By pushing the product outward N, the undercut R (3-2) is rotated and moved outward.

In order to ensure the undercut (3-2) (FIG. 3), the second sprue, the runner, and the rod of the air cylinder with the molded part placed on the upper surface of the mold, Alternatively, a method in which the molded product is forced to be moved and dropped by pressing a part with a component installed on it and using air together, or sandwiching a sprue and a runner with a rod and rod accessories.

The core is divided into several parts (in this case, two, six, and seven), one or several of them are provided with an undercut portion, and a spring (6) is provided at the bottom of the core-6 provided with the undercut. -2) to provide a gap structure (6-1) in which the molded product can move