JP2642993B2 - Plastic molding method - Google Patents

Plastic molding method

Info

Publication number
JP2642993B2
JP2642993B2 JP27149989A JP27149989A JP2642993B2 JP 2642993 B2 JP2642993 B2 JP 2642993B2 JP 27149989 A JP27149989 A JP 27149989A JP 27149989 A JP27149989 A JP 27149989A JP 2642993 B2 JP2642993 B2 JP 2642993B2
Authority
JP
Japan
Prior art keywords
mold
gas
plastic
injection
cavity
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.)
Expired - Fee Related
Application number
JP27149989A
Other languages
Japanese (ja)
Other versions
JPH03133618A (en
Inventor
義雄 鹿瀬
利男 宮島
Original Assignee
三菱重工業株式会社
中菱エンジニアリング株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 三菱重工業株式会社, 中菱エンジニアリング株式会社 filed Critical 三菱重工業株式会社
Priority to JP27149989A priority Critical patent/JP2642993B2/en
Publication of JPH03133618A publication Critical patent/JPH03133618A/en
Application granted granted Critical
Publication of JP2642993B2 publication Critical patent/JP2642993B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17Component parts, details or accessories; Auxiliary operations
    • B29C45/1703Introducing an auxiliary fluid into the mould
    • B29C45/1704Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles
    • B29C45/1705Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles using movable mould parts

Description

【発明の詳細な説明】 (産業上の利用分野) 本発明は射出成形機とプレスモールド成形機に適用さ
れる高精度なプラスチック成形品の成形方法に関するも
のである。
Description: TECHNICAL FIELD The present invention relates to a method for molding a high-precision plastic molded product applied to an injection molding machine and a press molding machine.
(従来の技術) 型キャビティを満たすに不充分な量の溶融樹脂を型キ
ャビティに注入した後、引続き同じ入口よりガス体を単
独で、或は溶融樹脂を注入しつつ圧入し、更に必要に応
じて溶融樹脂を注入して型キャビティを満たすことを特
徴とする中空型物の成形法が特公昭57−14968号公報に
示す如く提案されている。
(Prior art) After injecting an insufficient amount of molten resin into the mold cavity to fill the mold cavity, a gas body is continuously injected from the same inlet alone or while injecting the molten resin, and further, if necessary. Japanese Patent Publication No. Sho 57-14968 proposes a method for molding a hollow mold characterized by filling a mold cavity by injecting a molten resin.
前記従来の方法を実施する装置を第6図について説明
すると、射出シリンダ31内に、樹脂の可塑化及び射出を
行うスクリュ32で可塑化された樹脂39を貯め、溶融樹脂
39を型41及び42で作られた型キャビティ43に、同型キャ
ビティ43を満たす不充分な量の樹脂39を注入した後、引
続きノズル部につくられたガス体注入口34よりガス体を
圧入する。ガス体注入口34は、ノズル部の中央に装置部
品33で固定されており、ガス体は溶融樹脂の中を通っ
て、型キャビティ43に圧入される。なお、ガス体は別に
設けたガス圧入シリンダ35の高圧ラム36の前進により、
シリンダ35に貯められたガス体40を圧入するものであ
る。またガス体の圧入の方法は次の4法のうちいずれで
も良い。即ち、型キャビティを満たすに不充分な量の溶
融樹脂を注入した後、(1)ガス体を圧入、(2)ガス
体を圧入した後、更に溶融樹脂を注入、(3)溶融樹脂
を注入しつつガス体を圧入、(4)溶融樹脂を注入しつ
つガス体を圧入した後、更に溶融樹脂を注入、の4方法
のいずれでもよい。
Referring to FIG. 6, an apparatus for carrying out the above-mentioned conventional method will be described. A resin 39 plasticized by a screw 32 for plasticizing and injecting a resin is stored in an injection cylinder 31, and a molten resin
After injecting an insufficient amount of the resin 39 filling the mold cavity 43 into the mold cavity 43 formed by the molds 41 and 42, the gas body is subsequently press-fitted from the gas body injection port 34 formed in the nozzle portion. . The gas inlet 34 is fixed to the center of the nozzle portion by an apparatus component 33. The gas passes through the molten resin and is pressed into the mold cavity 43. In addition, the gas body is moved by the advance of the high pressure ram 36 of the gas press-in cylinder 35 separately provided.
The gas body 40 stored in the cylinder 35 is press-fitted. In addition, any one of the following four methods may be used for pressurizing the gas body. That is, after injecting an insufficient amount of molten resin to fill the mold cavity, (1) press-in the gas body, (2) press-in the gas body, then inject the molten resin further, and (3) inject the molten resin. (4) Pressurizing the gas while injecting the molten resin, and then injecting the molten resin.
しかし前記の従来方法は型キャビティ43の容積の変化
はなく、キャビティの薄い通路にプラスチックを流すの
で、高い射出力とガス圧力を必要とし、整形品に残留応
力を発生させる。
However, in the above-mentioned conventional method, since the volume of the mold cavity 43 does not change and the plastic flows through the thin passage of the cavity, a high firing power and gas pressure are required, and a residual stress is generated in the shaped product.
(発明が解決しようとする課題) 前記の従来方法で部分的中空型物成形品の製品精度
(寸法、表面精度)を上げようとすると、高圧ガスが必
要となる。即ち、高圧ガス取締法の容器、器具、取扱法
規等の制約を受ける問題が生じ、また型が完全に閉じた
状態で射出すると、プラスチックをキャビティの薄肉部
分に流し、キャビティの形に完全に沿った形で保持する
には高い射出圧力を必要とし、このまま冷却、固化する
と、成形品に残留応力が発生し、成形後に変形を起こす
欠点があった。
(Problems to be Solved by the Invention) In order to increase the product accuracy (dimensions, surface accuracy) of a partially hollow molded article by the above-mentioned conventional method, a high-pressure gas is required. That is, there is a problem of being restricted by containers, instruments, handling rules, etc. of the High Pressure Gas Control Law, and when the mold is injected in a completely closed state, the plastic flows into the thin portion of the cavity and completely follows the shape of the cavity. A high injection pressure is required to maintain the shape, and if it is cooled and solidified as it is, a residual stress is generated in the molded product, and there is a disadvantage that the molded product is deformed after molding.
本発明は前記従来の課題を解決するために提案された
ものである。
The present invention has been proposed to solve the above-mentioned conventional problems.
(課題を解決するための手段) このため本発明は、型を完全に閉じない寸開状態に置
いたまま溶融プラスチックを型キャビティに不充分な量
を注入し、引続き同じ型の注入口、又はプラスチックの
流路の任意の位置に設けたガスの注入口からガス体を注
入しつつ型内のプラスチックを膨らませ、次いで溶融プ
ラスチックとガスの注入路を閉じた後型締力を上昇させ
ると共に、完全に型を閉じて中空部をもったプラスチッ
クで型キャビティを満たし、かつプラスチック中空部内
ガスを高圧ガスにしてなるもので、これを課題解決のた
めの手段とするものである。
SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for injecting an insufficient amount of molten plastic into a mold cavity while leaving the mold in a slightly open state that does not completely close the mold, and subsequently injecting the same mold inlet, or The plastic in the mold is inflated while injecting gas from the gas inlet provided at an arbitrary position in the plastic flow path.Then, the injection path for the molten plastic and the gas is closed, and then the mold clamping force is increased and complete. The mold cavity is filled with plastic having a hollow portion by closing the mold, and the gas in the plastic hollow portion is converted into a high-pressure gas, which is used as a means for solving the problem.
(作用) 型内に溶融プラスチックを注入し、引続きガスを注入
してプラスチックを膨らませた後、型キャビティの容積
を縮めてガスを圧縮することにより高圧を得る。高圧に
なったプラスチック内部のガスで、キャビティの形に完
全に沿ったままでプラスチックを保持し冷却する。
(Operation) After injecting molten plastic into the mold and subsequently injecting gas to inflate the plastic, the volume of the mold cavity is reduced and the gas is compressed to obtain a high pressure. The gas inside the plastic at high pressure holds and cools the plastic while remaining completely in line with the shape of the cavity.
(実施例) 以下本発明を図面の実施例について説明すると、第1
図及び第2図は本発明の第1実施例を示し、通常の射出
成形機に適用した例である。
(Embodiments) The present invention will be described below with reference to the embodiments in the drawings.
FIG. 2 and FIG. 2 show a first embodiment of the present invention, which is an example applied to a normal injection molding machine.
図において1は射出シリンダで、内部に射出スクリュ
2、先端に射出シリンダ先端3を取付けてある。4はガ
ス注入部材で、ここにガス用接手8が取付けられると共
に、ガスは3方弁7によって注入、排出及び停止され
る。またガス注入部材4には2方弁5が組込まれてい
る。6はガス注入部材4の先端に設けられた射出ノズル
で、溶融プラスチック18はこのノズル6を通って型内に
注入される。
In the figure, reference numeral 1 denotes an injection cylinder, in which an injection screw 2 is mounted, and an injection cylinder tip 3 is mounted at the tip. Reference numeral 4 denotes a gas injection member to which a gas joint 8 is attached, and gas is injected, discharged and stopped by a three-way valve 7. Further, a two-way valve 5 is incorporated in the gas injection member 4. Reference numeral 6 denotes an injection nozzle provided at the tip of the gas injection member 4, through which the molten plastic 18 is injected into the mold.
9は固定型盤で、固定側の型10が取付けられている。
また11は移動型盤で、型12が取付けられている。13は型
押用油圧シリンダで、中を油圧ピストン14が滑動し、ピ
ストンロッド15により油圧力が型盤11に伝えられるよう
になっている。16は移動型盤11の位置検出用のリミット
スイッチで、型10,12の締切位置より少し戻った位置を
検出し、ピストン14を停止させて型を決められた位置に
保持すると共に、支持棒17により支えられて位置の調節
が出来るようになっている。また溶融プラスチック18
は、第1図では射出シリンダ先端部3及び射出リンダ1
に定量溜められた状態を示している。19は型10,12で形
成されたキャビティであり、第1図では型10,12の締切
りより少し戻った位置に、リミットスイッチ16により感
知され油圧ピストン14により位置保持されている状態を
示している。
Reference numeral 9 denotes a fixed mold plate on which a fixed mold 10 is attached.
Reference numeral 11 denotes a movable mold plate, on which a mold 12 is mounted. Reference numeral 13 denotes a mold-pressing hydraulic cylinder, in which a hydraulic piston 14 slides, and hydraulic pressure is transmitted to the mold plate 11 by a piston rod 15. Reference numeral 16 denotes a limit switch for detecting the position of the movable mold platen 11, which detects a position of the molds 10 and 12 slightly returned from the cut-off position, stops the piston 14 and holds the mold at a predetermined position, and also includes a support rod. The position can be adjusted by being supported by 17. Also molten plastic 18
In FIG. 1, the injection cylinder tip 3 and the injection cylinder 1
Fig. 3 shows a state in which a fixed amount is stored. Reference numeral 19 denotes a cavity formed by the molds 10 and 12, and FIG. 1 shows a state where the cavity is sensed by the limit switch 16 and is held at a position slightly returned from the cutoff of the molds 10 and 12 by the hydraulic piston 14. I have.
次に第1図の実施例について作用を、第2図の作業工
程に従い(a)〜(d)の順序に従って説明する。
Next, the operation of the embodiment of FIG. 1 will be described in accordance with the working steps of FIG. 2 and in the order of (a) to (d).
(a).型12を少し開いた状態で保持し、溶融プラスチ
ック18を注入する。型12はこれ以上開かぬよう弱い力f
で押えておくか、型押し油圧シリンダ13の作動油が逃げ
ないよう流路を閉じておく。
(A). While holding the mold 12 slightly open, the molten plastic 18 is injected. The mold 12 has a weak force f so as not to open any more.
Or the flow passage is closed so that the hydraulic oil of the embossed hydraulic cylinder 13 does not escape.
(b).溶融プラスチック18の注入の途中又は注入後、
ガス用の3方弁7を操作してガスを2方弁5と射出ノズ
ル6とを通して型内に注入する。この時型10と型12とは
少し開いており、キャビティは厚いのでプラスチックは
低い射出圧力で流れ、プラスチックの厚みの芯の部分は
まだ溶融状態にあり、粘度が低く、かつガス圧が低くて
も、ガスはプラスチックの中に入って行く。
(B). During or after the injection of molten plastic 18,
The gas is injected into the mold through the two-way valve 5 and the injection nozzle 6 by operating the three-way valve 7 for gas. At this time, the mold 10 and the mold 12 are slightly opened, the plastic flows at a low injection pressure because the cavity is thick, the core of the plastic thickness is still in a molten state, the viscosity is low, and the gas pressure is low. But gas goes into the plastic.
(c).2方片5を閉に、ガス用の3方弁7も閉にしてお
いて大きな型締力Fで型を締切る。この時溶融プラスチ
ック18は押し力で型10,12で形成されたキャビティ19に
充填されると共に、中空内のガスも圧縮されて高圧とな
り、溶融プラスチック18はキャビティの型に沿って強く
押し付けられたまま冷却、固化する。
(C). With the two pieces 5 closed and the three-way valve 7 for gas closed, the mold is closed with a large mold clamping force F. At this time, the molten plastic 18 was filled into the cavity 19 formed by the molds 10 and 12 with a pressing force, and the gas in the hollow was also compressed to a high pressure, and the molten plastic 18 was strongly pressed along the cavity mold. Cool and solidify as it is.
(d).プラスチック材の冷却、固化後、ガス3方弁7
を排気に操作し、2方弁5を開いてプラスチック中空部
内のガスを放出し、プラスチック成形品内のガス圧を充
分低下させてから、型12を開きキャビティ19内の樹脂を
成形品として取り出す。なお、プラスチック中空部内の
ガスは、固定側の型10からノズル6を後退させて生ずる
隙間より放出させてもよい。
(D). After cooling and solidifying the plastic material, gas three-way valve 7
Is operated to exhaust gas, the two-way valve 5 is opened to release the gas in the plastic hollow portion, the gas pressure in the plastic molded product is sufficiently reduced, and then the mold 12 is opened to take out the resin in the cavity 19 as a molded product. . The gas in the plastic hollow portion may be discharged from a gap formed by retracting the nozzle 6 from the fixed mold 10.
次に第3図の第2実施例について説明すると、この実
施例は第1実施例の溶融プラスチック注入時とガス注入
時に型を若干開いておき、溶融プラスチックとガスの入
口を塞いだ後に型締を行うことにより型キャビティ容積
を縮める代わりに、型は全閉にしておいて、横方よりプ
ランジャを押し込むことにより、型キャビティ容積を縮
小しようとする方式である。なお、第3図は型を若干開
にする方式を採らず、型の合せ目にプランジャを押し込
む構造を採る以外は、第1実施例と同じ構造である。
Next, the second embodiment of FIG. 3 will be described. In this embodiment, the mold is slightly opened at the time of injection of the molten plastic and at the time of gas injection of the first embodiment, and after closing the inlet of the molten plastic and gas, the mold is clamped. Instead of reducing the volume of the mold cavity by performing the above, the mold is fully closed and the plunger is pushed in from the side to reduce the volume of the mold cavity. FIG. 3 shows the same structure as that of the first embodiment, except that the mold is not opened slightly but a structure in which the plunger is pushed into the joint of the molds.
さて第3図において25は固定側の型で、油圧シリンダ
21を取付けてあり、同油圧シリンダ21にはピストン22及
びピストン軸兼用のプランジャ23が内蔵されている。26
は移動側の型で、この型が押し出されて固定側の型25と
圧着したとき、型25と型26の合せ面に中空の円筒が形成
されるようになっている。なお、この円筒の中心線は合
せ面上にある。またウランジャ23はこの型25と26で形成
された円筒内を出入でき、かつ同円筒は型25,26で形成
される型キャビティ24に通じている。
Now, in FIG. 3, reference numeral 25 denotes a fixed side mold, which is a hydraulic cylinder.
The hydraulic cylinder 21 has a built-in piston 22 and a plunger 23 also serving as a piston shaft. 26
Is a mold on the moving side, and when this mold is extruded and pressed against the mold 25 on the fixed side, a hollow cylinder is formed on the mating surface of the mold 25 and the mold 26. The center line of this cylinder is on the mating surface. Uranja 23 can enter and exit the cylinder formed by the molds 25 and 26, and the cylinder communicates with the mold cavity 24 formed by the molds 25 and 26.
次に第3図の第2実施例について作用を説明する。な
お、ここでは前記第1実施例の作用(作業工程)と比較
して説明する。
Next, the operation of the second embodiment shown in FIG. 3 will be described. Here, a description will be given in comparison with the operation (work process) of the first embodiment.
(a).型26を閉の位置まで充分に押し込み、溶融プラ
スチック18を注入する。
(A). The mold 26 is pushed fully to the closed position and the molten plastic 18 is injected.
(b).溶融プラスチック18の注入の途中又は注入後、
ガス用の3方弁7を操作してガス2方弁5と射出ノズル
6とを通して型25,26内に注入する。型内の溶融プラス
チック18は型25,26の壁に沿った部分は固まり始める
が、芯部分はまだ溶融状態にあり、ガス圧が低くてもガ
スは溶融プラスチック18内に入って行く。
(B). During or after the injection of molten plastic 18,
The gas is injected into the molds 25 and 26 through the gas two-way valve 5 and the injection nozzle 6 by operating the gas three-way valve 7. Although the molten plastic 18 in the mold starts to solidify along the walls of the molds 25 and 26, the core is still in a molten state, and gas enters the molten plastic 18 even at a low gas pressure.
(c).2方弁5を閉じ、ガス用の3方弁7も閉にしてお
いて、型26には充分型締力をかけたまま油圧によりプラ
ンジャ23を押し込む。この時溶融プラスチック18は型の
キャビティ24に充填されると共に、プラスチック中空内
のガスも圧縮されて高圧となり、プラスチックは型25,2
6にキャビティ24の型に沿って強く押し付けられたまま
冷却、固化する。
(C) With the two-way valve 5 closed and the three-way valve 7 for gas closed as well, the plunger 23 is pushed in by hydraulic pressure with sufficient mold clamping force applied to the mold 26. At this time, the molten plastic 18 is filled into the cavity 24 of the mold, and the gas in the plastic hollow is also compressed to a high pressure.
It cools and solidifies while being strongly pressed along the mold of the cavity 24 into 6.
(d).プラスチック材の冷却、固化後、ガス3方弁7
を排気に操作し、2方弁5を開いてプラスチック中空部
内のガス圧を放出し、成形品内のガス圧を充分低下させ
てから型26を開き、キャビティ24内の樹脂を成形品とし
て取り出す。
(D). After cooling and solidifying the plastic material, gas three-way valve 7
, The two-way valve 5 is opened to release the gas pressure in the hollow portion of the plastic, the gas pressure in the molded product is sufficiently reduced, the mold 26 is opened, and the resin in the cavity 24 is taken out as a molded product. .
次に第4図の第3実施例について説明すると、1は射
出シリンダで、内部に射出スクリュ2、先端に射出シリ
ンダ先端3を取付けてある。31は球形バルブ32を内蔵す
る逆止弁である。33はガス注入部材で、接手8、3方弁
7を通してガスの供給源に繋がっている。6は射出ノズ
ルで、溶融プラスチック及び注入ガスはこのノズル6を
通って下型10′内に注入される。12′は上型で型盤11に
取付けられており、同型盤11はプレス35の油圧シリンダ
34により上下移動を行い、かつ型押圧を加えられるよう
になっている。16はリミットスイッチで、型盤11の位置
検出用であり、位置の調整はバー17上で行う。35はプレ
スモールド用プレス、36は射出シリンダ1及びノズル固
定用ジャッキである。
Next, a third embodiment of FIG. 4 will be described. Reference numeral 1 denotes an injection cylinder, in which an injection screw 2 is mounted, and an injection cylinder tip 3 is mounted at the tip. Reference numeral 31 denotes a check valve incorporating a spherical valve 32. A gas injection member 33 is connected to a gas supply source through a joint 8 and a three-way valve 7. Reference numeral 6 denotes an injection nozzle through which molten plastic and an injection gas are injected into the lower mold 10 '. 12 'is an upper die which is mounted on the mold plate 11. The mold plate 11 is a hydraulic cylinder of the press 35.
34 allows vertical movement and mold pressing. Reference numeral 16 denotes a limit switch for detecting the position of the mold board 11, and the position is adjusted on a bar 17. 35 is a press for press molding, and 36 is a jack for fixing the injection cylinder 1 and the nozzle.
次に第4図の第3実施例の作用を、第5図の作業工程
に従い(a)〜(d)の順に説明する。
Next, the operation of the third embodiment shown in FIG. 4 will be described in the order of FIGS.
(a).上型12′を離したまま射出シリンダ1、射出ス
クリュ2で定量の溶融プラスチック18をノズル6から下
型10′に押し出す。この時ガス弁7は閉じている。
(A). While the upper mold 12 'is kept separated, a certain amount of the molten plastic 18 is extruded from the nozzle 6 to the lower mold 10' by the injection cylinder 1 and the injection screw 2. At this time, the gas valve 7 is closed.
(b).一定量の溶融プラスチック18の押し出しが終わ
った後、上型12′を下げて下型10′との締切りの少し手
前で停止する。この位置の検出はリミットスイッチ16で
行い、同リミットスイッチ16から送られる信号により、
油圧による上型12′の停止、位置保持の操作を行う。こ
の状態では溶融プラスチック18は潰されるが、ギャビテ
ィ37の隅々までは充填されていない。この時ガス3方弁
7は閉じている。
(B). After a certain amount of molten plastic 18 has been extruded, the upper mold 12 'is lowered and stopped shortly before the cutoff with the lower mold 10'. The detection of this position is performed by the limit switch 16, and a signal sent from the limit switch 16
The upper die 12 'is stopped and its position is maintained by hydraulic pressure. In this state, the molten plastic 18 is crushed, but is not filled up to the corners of the cavities 37. At this time, the gas three-way valve 7 is closed.
(c).ガス用3方弁7を切換えてガスを注入すると、
ガスはノズル6から型内の軟かいプラスチックに中空部
を形成しつつプラスチックを押し拡げる。
(C). When the gas is injected by switching the gas three-way valve 7,
The gas spreads the plastic from the nozzle 6 while forming a hollow in the soft plastic in the mold.
(d).ガス用3方弁7を閉じ、上型12′を強い型締力
Fで押すと、プラスチック中空部内のガスが高圧とな
り、プラスチックはキャビティ37に充填され、キャビテ
ィ37に沿って強く押付けられたまま冷却、固化する。
(D). When the gas three-way valve 7 is closed and the upper mold 12 'is pushed with a strong mold clamping force F, the gas in the plastic hollow becomes high pressure, the plastic is filled into the cavity 37, and the plastic is kept pressed strongly along the cavity 37. Cool and solidify.
冷却、固化後、ガス3方弁7を排出側に切り換えてキ
ャビティ37の成形品の内部のガスを抜くか、又は下型1
0′よりノズル6を後退させてできた隙間よりガスを放
出してから上型12′を上げて成形品を取り出す。
After cooling and solidification, the gas three-way valve 7 is switched to the discharge side to release the gas inside the molded product in the cavity 37, or the lower mold 1
The gas is released from the gap formed by retracting the nozzle 6 from 0 ', and then the upper mold 12' is raised to take out the molded product.
(発明の効果) 以上詳細に説明した如く本発明では、型を少し開いた
状態でガスを注入する時のガス圧は比較的低いが、ガス
注入後、ガスの通路を閉じ、強大な型締力で型を押すの
で、ガス圧は高圧となる。従って本発明によると、高圧
ガス取締法適用外の比較的低いガスの供給減を使用し、
型締力を利用して高圧ガスと為し、大きな内圧力による
プラスチック材の型への押付けが行われるので、ひけの
ない、精度の良い、表面の美麗な成形品が得られる。な
お、型を少し開いた状態で射出ガス注入を行うようにす
れば、射出圧力、ガス圧力は低くでき、また射出後型を
圧縮するため分子配向が均一化されるので、内部応力の
小さい成形後の変形の小さな成形品が得られる。またキ
ャビティを部分的に圧縮して内部ガス圧を高くし、大き
な内圧でプラスチック材を型のキャビティに沿って強く
押しつけるようにすれば、ひけのない美麗な成形品が得
られる。
(Effects of the Invention) As described in detail above, in the present invention, the gas pressure when injecting gas with the mold slightly opened is relatively low, but after gas injection, the gas passage is closed and the mold is strongly clamped. Since the mold is pressed by force, the gas pressure becomes high. Therefore, according to the present invention, using a relatively low supply of gas that is not applicable to the High Pressure Gas Control Law,
A high pressure gas is produced by using the mold clamping force, and the plastic material is pressed against the mold by a large internal pressure, so that a molded product with no sink marks, high accuracy, and a beautiful surface can be obtained. If the injection gas is injected while the mold is slightly opened, the injection pressure and gas pressure can be reduced, and after the injection, the mold is compressed, so that the molecular orientation is uniform, so that molding with small internal stress is performed. A molded article with a small deformation afterwards is obtained. If the internal gas pressure is increased by partially compressing the cavity and the plastic material is strongly pressed along the cavity of the mold with a large internal pressure, a beautiful molded product without sinking can be obtained.
【図面の簡単な説明】[Brief description of the drawings]
第1図は本発明の第1実施例の方法を実施する装置の平
面断面図、第2図(a)(b)(c)(d)は第1図の
装置における作動の順序を順に示す説明図、第3図は本
発明の第2実施例の方法を実施する装置の平面断面図、
第4図は本発明の第3実施例の方法を実施する装置の平
面断面図、第5図(a)(b)(c)(d)は第4図の
装置における作動の順序を順に示す説明図、第6図は従
来の射出方法を示す装置の断面図である。 図の主要部分の説明 1……射出シリンダ 2……射出スクリュ 4……ガス注入部材 5……2方弁 6……射出ノズル 7……3方弁 9……固体型盤 10……固定側の型 11……移動型盤 12……型 13……型押用油圧シリンダ 14……油圧ピストン 15……ピストンロッド 16……位置検出用リミットスイッチ 18……溶融プラスチック 19……キャビティ
FIG. 1 is a plan sectional view of an apparatus for carrying out the method according to the first embodiment of the present invention, and FIGS. 2 (a), 2 (b), 2 (c) and 2 (d) show the order of operation in the apparatus of FIG. FIG. 3 is a plan sectional view of an apparatus for performing the method according to the second embodiment of the present invention;
FIG. 4 is a plan sectional view of an apparatus for performing the method of the third embodiment of the present invention, and FIGS. 5 (a), (b), (c) and (d) show the order of operation in the apparatus of FIG. FIG. 6 is a sectional view of an apparatus showing a conventional injection method. Description of main parts in the drawing 1 ... Injection cylinder 2 ... Injection screw 4 ... Gas injection member 5 ... 2 way valve 6 ... Injection nozzle 7 ... 3 way valve 9 ... Solid mold board 10 ... Fixed side Mold 11… Movable mold plate 12 …… Model 13 …… Hydraulic cylinder for stamping 14 …… Hydraulic piston 15 …… Piston rod 16 …… Limit switch for position detection 18 …… Molten plastic 19 …… Cavity

Claims (1)

    (57)【特許請求の範囲】(57) [Claims]
  1. 【請求項1】型を完全に閉じない寸開状態に置いたまま
    溶融プラスチックを型キャビティに不充分な量を注入
    し、引続き同じ型への注入口、又はプラスチックの流路
    の任意の位置に設けたガスの注入口からガス体を注入し
    つつ型内のプラスチックを膨らませ、次いで溶融プラス
    チックとガスの注入路を閉じた後型締力を上昇させると
    共に、完全に型を閉じて中空部をもったプラスチックで
    型キャビティを満たし、かつプラスチック中空部内ガス
    を高圧ガスにすることを特徴とするプラスチック成形品
    の成形方法。
    1. Injecting an insufficient amount of molten plastic into a mold cavity while leaving the mold in a slightly open state that does not completely close the mold, and subsequently injecting into the same mold, or any position in the plastic flow path. The plastic in the mold is inflated while injecting a gas body from the gas inlet provided, then the injection path of the molten plastic and the gas is closed, and then the mold clamping force is increased, and the mold is completely closed to form a hollow portion. A method of molding a plastic molded article, characterized in that a mold cavity is filled with a plastic and a gas in a plastic hollow portion is a high-pressure gas.
JP27149989A 1989-10-20 1989-10-20 Plastic molding method Expired - Fee Related JP2642993B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP27149989A JP2642993B2 (en) 1989-10-20 1989-10-20 Plastic molding method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27149989A JP2642993B2 (en) 1989-10-20 1989-10-20 Plastic molding method

Publications (2)

Publication Number Publication Date
JPH03133618A JPH03133618A (en) 1991-06-06
JP2642993B2 true JP2642993B2 (en) 1997-08-20

Family

ID=17500910

Family Applications (1)

Application Number Title Priority Date Filing Date
JP27149989A Expired - Fee Related JP2642993B2 (en) 1989-10-20 1989-10-20 Plastic molding method

Country Status (1)

Country Link
JP (1) JP2642993B2 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0622834B2 (en) * 1990-07-10 1994-03-30 株式会社日本製鋼所 Injection compression molding method and apparatus
JP2976059B2 (en) * 1991-02-08 1999-11-10 住友化学工業株式会社 Manufacturing method of hollow molded products
US5344596A (en) * 1992-03-23 1994-09-06 Icp Systems, Inc. Method for fluid compression of injection molded plastic material
KR100497970B1 (en) * 2002-08-13 2005-07-01 현대모비스 주식회사 Injection molder for mixing gas

Also Published As

Publication number Publication date
JPH03133618A (en) 1991-06-06

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