JPS6024914A - Injection molding machine - Google Patents
Injection molding machineInfo
- Publication number
- JPS6024914A JPS6024914A JP13329483A JP13329483A JPS6024914A JP S6024914 A JPS6024914 A JP S6024914A JP 13329483 A JP13329483 A JP 13329483A JP 13329483 A JP13329483 A JP 13329483A JP S6024914 A JPS6024914 A JP S6024914A
- Authority
- JP
- Japan
- Prior art keywords
- mold
- molten resin
- nozzle cylinder
- injection
- screw
- 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.)
- Pending
Links
Landscapes
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は寸法精度が高く、空隙のない成形品を成形し得
る射出成形機に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molding machine that can mold a molded product with high dimensional accuracy and no voids.
最近、合成樹脂の射出成形品は厚肉化傾向にあり、さら
にガラス繊維や各種充填剤を混入して高強度、難燃性等
をもたせることになり、その用途はエンジニアプラスチ
ックの分野にまで拡大してきている。そのため特性、寸
法精度ともに高水準の射出成形品を成形し得る射出成形
機の開発が強く望まれている。In recent years, synthetic resin injection molded products have become thicker, and glass fiber and various fillers have been mixed in to give them high strength and flame retardancy, and their use has expanded to the field of engineering plastics. I've been doing it. Therefore, there is a strong desire to develop an injection molding machine that can mold injection molded products with high levels of properties and dimensional accuracy.
第１図は、従来の射出スクリュー１を射出シリンダー２
内に内装した射出成形機の一例を図示したものである。Figure 1 shows a conventional injection screw 1 and an injection cylinder 2.
This figure shows an example of an injection molding machine installed inside the machine.
射出シリンダー２および射出用スクリュー１の後部には
、このスクリュー１を駆動させる駆動機構４が設けられ
、前部のヘッドには固定金型５ａと移動金型５ｂからな
る金型５が樹脂通路を一致させて固定されている。A drive mechanism 4 for driving the injection cylinder 2 and the injection screw 1 is provided at the rear of the injection cylinder 2 and the injection screw 1, and a mold 5 consisting of a fixed mold 5a and a movable mold 5b is installed at the front head of the injection cylinder 2 and the injection screw 1. The match has been fixed.
このような射出成形機においては、まず、スクリュー１
０回転によりホッパー３内の合成樹脂が射出シリンダー
２内に送り込まれ、溶融混練されながら順次前進し、そ
の先端部に蓄積される。スクリュー１がさらに回転を続
ける゛ことにより先端部に順次溶融した合成樹脂が蓄積
される一方、スクリューは後退し一射出分の合成樹脂が
蓄積したところで停止する。しかるのち後部の駆動機構
４によりスクリューが前進し、溶融蓄積された合成樹脂
６が金型５内に充填され、次いで冷却固化されて成形品
が得られる。In such an injection molding machine, first, the screw 1
By the zero rotation, the synthetic resin in the hopper 3 is fed into the injection cylinder 2, and while being melted and kneaded, it advances one by one and is accumulated at its tip. As the screw 1 continues to rotate further, molten synthetic resin is accumulated at the tip, while the screw retreats and stops when the amount of synthetic resin for one injection has accumulated. Thereafter, the screw is advanced by the drive mechanism 4 at the rear, and the mold 5 is filled with the molten and accumulated synthetic resin 6, which is then cooled and solidified to obtain a molded product.
このような従来の射出成形機では、合成樹脂が金型内で
冷却固化される間に合成樹脂の熱収縮によるヒケや空隙
が生じ易く、成形品に歪みや変形が起こることは避けら
れず寸法精度の高い製品を得ることは困難である。In such conventional injection molding machines, sink marks and voids are likely to occur due to heat shrinkage of the synthetic resin while the synthetic resin is cooled and solidified in the mold, which inevitably causes distortion and deformation of the molded product. It is difficult to obtain products with high precision.
このような問題を解決するには溶融樹脂の金型内への充
填射出圧力を高くシ、かつこの状態を保持したまま冷却
同化を行うようにすればよく、最近かなし高い射出圧力
の射出成形機も開発されている。しかしながらスクリュ
一式の射出成形機においては高圧になればなる程スクリ
ュースリットからの溶融樹脂のバックフローは大となり
、充分な効果を得ることが難しくなる。またこのバック
フロー防止のためにチェックリング等を使用したものも
知られているがチェックリング等を使用すれば硬質塩化
ビニル樹脂のような溶融粘度の高い合成樹脂では合成樹
脂の滞留による焼けが生じ易くなるという難点がある。To solve this problem, the injection pressure for filling the molten resin into the mold can be increased, and cooling and assimilation can be performed while maintaining this state.Recently, high injection pressure injection molding A machine is also being developed. However, in a screw injection molding machine, the higher the pressure, the greater the backflow of molten resin from the screw slit, making it difficult to obtain sufficient effects. There are also known devices that use check rings to prevent this backflow, but if check rings are used, synthetic resins with high melt viscosity such as hard vinyl chloride resins will suffer from burning due to retention of the synthetic resin. The problem is that it becomes easier.
さらにこのような射出成形機では、スクリュー断面に高
圧力を受けるのでスクリュー材質の座屈強度との関係か
らアマリスクリューの長さを長くできないという問題も
ある。Furthermore, in such an injection molding machine, there is a problem that the length of the amarylic screw cannot be increased due to the buckling strength of the screw material since the cross section of the screw is subjected to high pressure.
本発明者はこのような事情に基づき、合成樹脂の熱収縮
に打ちかつような高い射出圧力をもち、その結果精密で
高品質な成形品が得られる射出成形機を提供しようとし
、スクリューの先端に、このスクリューより小径の円柱
状ピストン部を突設するとともにシリンダー先端のヘッ
ド部の樹脂通路に前記円柱状ピストン部を受入れるノズ
ルシリンダ一部を形成することにより、高い射出圧力を
得た。しかしこのような射出成形機においても、円柱状
ピストン部とノズルシリンダー内壁との僅かな間隙から
溶融樹脂がバックフローするのを完全に防止することが
難しい。Based on these circumstances, the present inventor sought to provide an injection molding machine that has a high injection pressure that can overcome the heat shrinkage of synthetic resins, and as a result can produce precision and high quality molded products. In addition, a high injection pressure was obtained by protruding a cylindrical piston portion with a smaller diameter than the screw and forming a part of the nozzle cylinder that receives the cylindrical piston portion in the resin passage of the head portion at the tip of the cylinder. However, even in such an injection molding machine, it is difficult to completely prevent molten resin from backflowing through the small gap between the cylindrical piston and the inner wall of the nozzle cylinder.
本発明は、円柱状ピストン部とノズルシリンダー内壁と
の間隙を実質的になくすことにより、溶融樹脂のバック
フローを無くシ、もって高い射出圧力が効率的に得られ
、精密で高い品質の成形品を成形し得る射出成形機を提
供することを目的とする。The present invention eliminates the backflow of molten resin by substantially eliminating the gap between the cylindrical piston part and the inner wall of the nozzle cylinder, thereby efficiently obtaining high injection pressure and producing precision and high quality molded products. The purpose of the present invention is to provide an injection molding machine capable of molding.
本発明の要旨は、スクリューが前進してシリンダー内の
溶融樹脂をヘッド先端に装着した金型内に圧入するよう
にした射出成形機において、前記スクリューの先端に、
このスクリューより小径の円柱状ピストン部を突設し、
かつ前記ヘッドの樹脂通路に前記円柱状ピストン部を受
入るノズルシリンダ一部を形成しており、前記円柱状ピ
ストン部に周溝を設け、この周溝に、ノズルシリンダ一
部の外径と同一もしｋはそれよりやや犬なる外径を有し
、かつピストン部の外径より小さい内径を有するリング
を装着してなることを特徴とする射出成形機に存する。The gist of the present invention is to provide an injection molding machine in which a screw moves forward and press-fits molten resin in a cylinder into a mold attached to a head tip.
A cylindrical piston part with a smaller diameter is provided protruding from this screw,
and a part of a nozzle cylinder that receives the cylindrical piston part is formed in the resin passage of the head, a circumferential groove is provided in the cylindrical piston part, and the circumferential groove has a diameter that is the same as the outer diameter of the part of the nozzle cylinder. If k is an injection molding machine characterized in that it is equipped with a ring having an outer diameter slightly smaller than that and an inner diameter smaller than the outer diameter of the piston part.
以下本発明の一実施例を図面を用いて詳細に説明する。An embodiment of the present invention will be described in detail below with reference to the drawings.
第２図は本発明の射出成形機の一実施例の要部の縦断面
図である。なお、同図において第１図と共通する部分に
は同一の符号を付しである。FIG. 2 is a longitudinal cross-sectional view of essential parts of an embodiment of the injection molding machine of the present invention. In this figure, parts common to those in FIG. 1 are given the same reference numerals.
第２図において、符号１は図示を省略した駆動機構によ
り射出シリンダー２中で、前後進および回転可能なスク
リューで、その先端には回動軸と同軸に円柱状ピストン
部７が突設されている。射出シリンダー２の先端に装着
されたヘッドＨの樹脂通路にはこの円柱状ピストン部７
を受入れるノズルシリンダ一部８が形成されている。円
柱状ピストン部７の先端に周溝７１が設けられ、との周
溝７１に、耐熱性ゴム、耐熱性合成樹脂等からなるある
程度の弾性を有するリング９が装着されている。リング
９の外径右はノズルシリンダ一部８の内径＾と同一かや
や大きくされている。またリング９の内径ｔ３ はピス
トン部７の外径ｔ４ より小サイ。リング９を周溝７１
に装着する釦はピストン部７の先端部より強制的に嵌合
してもよいが図示の如くピストン部７の先端部を別体と
して着脱可能にしておけばリング９の装着、交換等が容
易となる。In FIG. 2, reference numeral 1 denotes a screw that can be moved forward and backward and rotated in the injection cylinder 2 by a drive mechanism (not shown), and a cylindrical piston portion 7 is provided protruding from the tip of the screw coaxially with the rotation axis. There is. This cylindrical piston portion 7 is located in the resin passage of the head H attached to the tip of the injection cylinder 2.
A nozzle cylinder part 8 is formed which receives the nozzle cylinder. A circumferential groove 71 is provided at the tip of the cylindrical piston portion 7, and a ring 9 having a certain degree of elasticity and made of heat-resistant rubber, heat-resistant synthetic resin, etc. is attached to the circumferential groove 71. The right outer diameter of the ring 9 is the same as or slightly larger than the inner diameter of the nozzle cylinder part 8. Also, the inner diameter t3 of the ring 9 is smaller than the outer diameter t4 of the piston portion 7. Ring 9 in circumferential groove 71
The button attached to the ring 9 may be forcibly fitted from the tip of the piston 7, but if the tip of the piston 7 is made detachable as a separate body as shown in the figure, it will be easier to attach and replace the ring 9. becomes.
また、リング９は割リング状でもよいがその場合には複
数個をその切欠き部の位置をすらし装着するのが好まし
い。さらにヘッドＨのノズルシリンタ一部８の後方には
溶融樹脂６ｂを一時的に逃がす逃は場１０が設けられて
いる。この逃げ場１０は油圧シリンダー１１のピストン
の前後進により開閉自在とされている。Further, the ring 9 may be in the shape of a split ring, but in that case, it is preferable to attach a plurality of rings with their notched portions aligned. Further, behind the nozzle cylinder part 8 of the head H, an escape field 10 is provided to temporarily release the molten resin 6b. This escape area 10 can be opened and closed by moving the piston of the hydraulic cylinder 11 back and forth.
上記溝底の射出成形機を用いて射出成形するには、まず
スクリュー１の回転により図示を省略したホッパーより
送り込まれた合成樹脂６ａは射出シリンダー２内を溶融
混練されながら順次前進し、次いで内圧によりスクリュ
ー１は後退し、−射出量分の溶融樹脂６ｂが蓄積された
位置で停止する。To carry out injection molding using the groove-bottomed injection molding machine, first, the synthetic resin 6a fed from a hopper (not shown) by the rotation of the screw 1 is sequentially advanced inside the injection cylinder 2 while being melted and kneaded, and then the internal pressure The screw 1 moves backward and stops at the position where the molten resin 6b equivalent to the injection amount has been accumulated.
続いて後部の駆動機構からの圧力でスクリュー１は前進
し、射出工程に入り、金型５内に溶融樹脂が充填される
。次いで、円柱状ピストン部７に装着されたリング９が
ノズルシリンダ一部８の端部に接触する。このとき、リ
ング９はノズルシリンタ一部８の内径り、と同一かやや
大きくなされた外径ｔ、を有するので、ノズルシリンダ
一部８内の溶融樹脂６ｃは射出シリンダー２内の溶融樹
脂６ｂと完全に分離され、逃げ場１０は油圧シリンダー
１１のピストンの後退に伴なって順次開放される。Subsequently, the screw 1 is moved forward by the pressure from the rear drive mechanism, enters the injection process, and the mold 5 is filled with molten resin. A ring 9 mounted on the cylindrical piston part 7 then contacts the end of the nozzle cylinder part 8. At this time, since the ring 9 has an outer diameter t that is the same as or slightly larger than the inner diameter of the nozzle cylinder part 8, the molten resin 6c in the nozzle cylinder part 8 is completely equal to the molten resin 6b in the injection cylinder 2. The escape areas 10 are sequentially opened as the piston of the hydraulic cylinder 11 retreats.
スクリュー１は前進を続は円柱状ピストン部７がノズル
シリンダ一部８内に侵入するにともないノズルシリンダ
一部８後方の溶融樹脂６ｂは逃げ場１０に入る。その結
果射出圧力は、スクリュー径より小さな内径をもつ円柱
状ピストン部断面に加えられ、ノズルシリンダ一部８内
の溶融樹脂６Ｃを介して高い射出圧力が金型５内に加え
られ、溶融樹脂６ｃの一部が高圧でもって金型５内に補
充充填される。金型内に圧入された溶融樹脂６ｄは、こ
の高圧下で冷却固化され金ｍ５内の型窩どおりの形状に
成形される。As the screw 1 continues to move forward and the cylindrical piston part 7 enters the nozzle cylinder part 8, the molten resin 6b behind the nozzle cylinder part 8 enters the escape area 10. As a result, injection pressure is applied to the cross section of the cylindrical piston portion having an inner diameter smaller than the screw diameter, and high injection pressure is applied to the mold 5 through the molten resin 6C in the nozzle cylinder part 8, and the molten resin 6c A part of the liquid is replenished into the mold 5 under high pressure. The molten resin 6d press-fitted into the mold is cooled and solidified under this high pressure and molded into the shape of the mold cavity in the metal m5.
この実施例の射出成形機によれば、金型内には円柱状ピ
ストン部とノズルシリンダ一部により高圧が加えられる
のでスクリュースリットからのバックフローは、完全に
防止することができ、この実施例の射出成形機は特に硬
質塩化ビニル樹脂等の溶融粘度の高い合成樹脂に適する
。According to the injection molding machine of this embodiment, high pressure is applied inside the mold by the cylindrical piston part and part of the nozzle cylinder, so backflow from the screw slit can be completely prevented. This injection molding machine is particularly suitable for synthetic resins with high melt viscosity such as hard vinyl chloride resin.
以上説明したように本発明の射出成形機によれば、溶融
樹脂の金型充填過程の最終段階および金型内での冷却過
程において高い射出圧力が維持されるので、空隙の発生
がなく、精度、品質ともに優れた製品を成形することが
できる。しかもスクリューの推力は従来と変らないので
、汎用射出成形機の一部を改造するだけでもよく、また
溶融樹脂の金型充填の前段階では低射出圧力でょいがら
、射出シリンダー及びスクリューの径を大きくでき、射
出ストロークを小さくできるので小形化でき極めて経済
的である。As explained above, according to the injection molding machine of the present invention, a high injection pressure is maintained during the final stage of filling the mold with molten resin and during the cooling process within the mold, so there is no generation of voids and precision. , it is possible to mold products with excellent quality. Moreover, the thrust force of the screw is the same as before, so it is only necessary to modify a part of the general-purpose injection molding machine, and in the pre-filling stage of mold filling with molten resin, the injection cylinder and screw diameters are quite low. Since the injection stroke can be made small and the injection stroke can be made small, it can be made compact and extremely economical.
第１図は従来射出成形機の一例の断面図、第２図は本発
明の射出成形機の一実施例を示す断面図、第３図は同上
のピストンリングの部分拡大図であ 辻る。
１・・・・・・・・・・・・スクリュー２・・・・・・
・・・・・・射出シリンダー３・・・・・・・・・・・
・ホッパー
４・・・・・・・・・・・・駆動機構
５・・・・・・・・・・・・金型
５ａ・・・・・・・・・固定金型
５ｂ・・・・・・中移動金型
６・・・・・・・・・・・・溶融樹脂
６ａ、６ｂ・・・溶融樹脂
７・・・・・・・・・・・・円柱状ピストン８・・・・
・・・・・・・・ノズルシリンダ一部９・・・・・・・
・・・・・逃げ場
■・・・・・・・・・・・・ヘッド
ｊ願人 積水化学工業株式会社
代表者 藤沼基利FIG. 1 is a sectional view of an example of a conventional injection molding machine, FIG. 2 is a sectional view of an embodiment of the injection molding machine of the present invention, and FIG. 3 is a partially enlarged view of the same piston ring. １・・・・・・・・・・・・Screw 2・・・・・・
・・・・・・Injection cylinder 3・・・・・・・・・・・・
・Hopper 4... Drive mechanism 5... Mold 5a... Fixed mold 5b... ...Medium moving mold 6...Melted resin 6a, 6b...Melted resin 7...Cylindrical piston 8...
・・・・・・Nozzle cylinder part 9・・・・・・
・・・・・・Escape■・・・・・・・・・・・・Head J Applicant Sekisui Chemical Co., Ltd. Representative Mototoshi Fujinuma
Claims (1)
先端に装着した金型内に圧入するようにした射出成形機
において、前記スクリューの先端に、このスクリューよ
り小径の円柱状ピストン部を突設し、かつ前記ヘッドの
樹脂通路に前記円柱状ピストン部を受入れるノズルシリ
ンダ一部を形成しており、前記円柱状ピストン部に周溝
を設け、該周溝に、ノズルシリンダーの内径と同一もし
くはそれよりやや大なる外径を有し、かつピストン部の
外径よ秒小さい内径を有する゛リングを装着してなるこ
とを特徴とする射出成形機。In an injection molding machine in which a screw moves forward to press-fit molten resin in a cylinder into a mold attached to the tip of the head, a cylindrical piston portion having a smaller diameter than the screw is protruded from the tip of the screw, and a part of a nozzle cylinder that receives the cylindrical piston part is formed in the resin passage of the head, a circumferential groove is provided in the cylindrical piston part, and the circumferential groove has a diameter that is the same as or slightly larger than the inner diameter of the nozzle cylinder. An injection molding machine characterized by being equipped with a ring having a large outer diameter and an inner diameter smaller than the outer diameter of a piston part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13329483A JPS6024914A (en) | 1983-07-20 | 1983-07-20 | Injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13329483A JPS6024914A (en) | 1983-07-20 | 1983-07-20 | Injection molding machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6024914A true JPS6024914A (en) | 1985-02-07 |
Family
ID=15101287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13329483A Pending JPS6024914A (en) | 1983-07-20 | 1983-07-20 | Injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6024914A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9931773B2 (en) | 2014-12-04 | 2018-04-03 | Extrude To Fill, LLC | Injection molding system and method of fabricating a component |
| US10086550B2 (en) | 2014-12-04 | 2018-10-02 | Extrude To Fill, LLC | Molding machine and method of molding a part |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5677126A (en) * | 1979-11-29 | 1981-06-25 | Yamashiro Seiki Seisakusho:Kk | Injection molding machine for high injection pressure use |
-
1983
- 1983-07-20 JP JP13329483A patent/JPS6024914A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5677126A (en) * | 1979-11-29 | 1981-06-25 | Yamashiro Seiki Seisakusho:Kk | Injection molding machine for high injection pressure use |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9931773B2 (en) | 2014-12-04 | 2018-04-03 | Extrude To Fill, LLC | Injection molding system and method of fabricating a component |
| US10086550B2 (en) | 2014-12-04 | 2018-10-02 | Extrude To Fill, LLC | Molding machine and method of molding a part |
| US11292178B2 (en) | 2014-12-04 | 2022-04-05 | Extrude to Fill, Inc. | Nozzle shut off for injection molding system |
| US11945150B2 (en) | 2014-12-04 | 2024-04-02 | Extrude to Fill, Inc. | Nozzle shut off for injection molding system |
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