JPS6160764B2 - - Google Patents
Info
- Publication number
- JPS6160764B2 JPS6160764B2 JP55025973A JP2597380A JPS6160764B2 JP S6160764 B2 JPS6160764 B2 JP S6160764B2 JP 55025973 A JP55025973 A JP 55025973A JP 2597380 A JP2597380 A JP 2597380A JP S6160764 B2 JPS6160764 B2 JP S6160764B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- mold
- injection
- resin
- gate
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/46—Means for plasticising or homogenising the moulding material or forcing it into the mould
- B29C45/57—Exerting after-pressure on the moulding material
- B29C45/572—Exerting after-pressure on the moulding material using movable mould wall or runner parts
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】
この発明は合成樹脂材料の射出成形方法に関す
るものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for injection molding synthetic resin materials.
通常の手段による射出成形では、ゲート部分を
中心に射出時の大きな応力が残留内部歪として成
形品に残る。この歪を低減する手段として、金型
内に充填した樹脂に圧縮力を加える方法が既に公
知となつている。その一つは、やや低い圧力で金
型を閉じておき、充填圧力によつて金型をわずか
に開かせたのち、型締圧力を増大させて金型を完
全に閉じ、そのときに充填樹脂に圧縮力を加える
場合と、通常の方法で射出を行つたのち、突出し
ピン兼用のプランジヤを充填樹脂に圧入する場合
とがある。 In injection molding using normal means, large stress during injection remains in the molded product as residual internal strain around the gate portion. As a means to reduce this distortion, a method of applying compressive force to the resin filled in the mold is already known. One method is to close the mold with a slightly low pressure, then open the mold slightly using the filling pressure, then increase the clamping pressure to completely close the mold, and then fill the mold with the resin. In some cases, a compressive force is applied to the resin, and in other cases, a plunger, which also serves as an ejector pin, is press-fitted into the filled resin after injection is performed in the usual manner.
上記従来方法のうち、前者は金型を開いておい
て充填してから完全に閉じるため、複雑な金型に
は不適当であり、またバリが発生し易く、金型を
充填圧により適度に開くことにも技術上の困難さ
があつた。 Of the conventional methods mentioned above, the former method is unsuitable for complex molds because the mold is opened, filled, and then completely closed.Furthermore, burrs are likely to occur, and the mold is not properly filled with filling pressure. There were also technical difficulties in opening it.
次に後者は金型を完全に閉じて行うことから、
前者のような欠点はないが、突出ピンなどを圧入
する関係上、よほどの厚肉で収縮率の大きな樹脂
でなければ応用できず、その利用も厚肉のヒケ、
ボイド防止に止どまる。 Next, since the latter is done with the mold completely closed,
Although it does not have the disadvantages of the former, since it involves press-fitting protruding pins, etc., it cannot be applied unless the resin is extremely thick and has a high shrinkage rate, and its use can also be used to prevent sinks and sinks in thick walls.
It stops at preventing voids.
この発明は金型を完全かつ強力に閉鎖した状態
において、金型内の充填樹脂に圧力を付与し、そ
の圧力によつて射出時に生じた充填樹脂中の不当
な圧力をゲートより射出シリンダー側へ逃出さ
せ、内部歪の少ない精密成形品を能率よく成形す
ることができる新たな方法を提供しようとするも
のである。 This invention applies pressure to the filled resin in the mold when the mold is completely and strongly closed, and the unreasonable pressure in the filled resin generated during injection is transferred from the gate to the injection cylinder side. The objective is to provide a new method that allows for efficient molding of precision molded products with little internal strain.
以下この発明を図示の例により詳細に説明す
る。 The present invention will be explained in detail below using illustrated examples.
１は固定盤２に取付けた固定金型、３はタイバ
ー４，４を摺動移動する型締板５に取付けた可動
金型で、キヤビテイ中央部はプランジヤ６による
可動キヤビテイとなつている。この可動キヤビテ
イは成形品の特に精度または内部歪の少ないこと
を要求される部分の大きさ（面積）とすることが
好ましい。 1 is a fixed mold attached to a fixed platen 2; 3 is a movable mold attached to a mold clamping plate 5 on which tie bars 4, 4 are slidably moved; the central part of the cavity is a movable cavity by a plunger 6. It is preferable that this movable cavity has a size (area) of a portion of the molded product that requires particularly high precision or low internal distortion.
７は上記可動キヤビテイの油圧シリンダーで、
ラム８に連結したプレート９にプランジヤが取付
けてある。１０はノツクアウトピンで、上記型締
板５に内装した油圧シリンダー１１のラム１２に
より作動する。 7 is the hydraulic cylinder of the movable cavity,
A plunger is attached to a plate 9 connected to the ram 8. Reference numeral 10 denotes a knockout pin, which is operated by a ram 12 of a hydraulic cylinder 11 housed in the mold clamping plate 5.
第２図は上記油圧シリンダー７の回路を示すも
ので、V1は切換バルブ、V2は押圧力調整バル
ブ、V3は押圧力を制御信号により変化させる電
磁リリーフバルブである。また１３は上記可動キ
ヤビテイのプランジヤ６が設定値以上に前進し、
充填樹脂を不当に押圧するのを防止するリミツト
スイツチ或は光電子スイツチなどからなる異常前
進検出器である。 FIG. 2 shows the circuit of the hydraulic cylinder 7, where V 1 is a switching valve, V 2 is a pressing force adjustment valve, and V 3 is an electromagnetic relief valve whose pressing force is changed by a control signal. Further, 13 indicates that the plunger 6 of the movable cavity advances beyond a set value,
This is an abnormal advance detector consisting of a limit switch or a photoelectronic switch that prevents the filled resin from being unduly pressed.
しかして、第３図に示す光学部品１４の成形を
例としてこの発明の方法を以下に述べる。なお光
学部品１４にあつては、周辺１４ａよりも中央部
の光透過部１４ｂに可動キヤビテイによる圧力を
付与する。まず金型１のゲートに射出装置１５を
ノズルタツチさせて溶融樹脂の射出を行う。この
際金型１，３は型締板５をもつて完全かつ強力に
閉鎖して置き、またプランジヤ６は後退位置にセ
ツトして置く。 The method of the present invention will be described below using the molding of the optical component 14 shown in FIG. 3 as an example. In the case of the optical component 14, the movable cavity applies more pressure to the light transmitting portion 14b in the center than to the periphery 14a. First, the nozzle of the injection device 15 is touched to the gate of the mold 1 to inject molten resin. At this time, the molds 1 and 3 are completely and strongly closed with the mold clamping plate 5, and the plunger 6 is set in the retracted position.
次に充填が完了したならば、射出装置５をノズ
ルタツチさせたまま上記油圧シリンダー１１を作
動してプランジヤ６を充填樹脂１６へと押圧し、
硬化する前に充填樹脂１６に出力を付与する。な
お、このときの油圧シリンダー７の出力は、型締
力の１／10〜１／20程度でよく、またプランジヤ
６の押出ストロークは、金型１，３や材料樹脂、
成形条件によつて異なるが、通常0.01〜0.2mm程
度である。 Next, when the filling is completed, the hydraulic cylinder 11 is operated while the nozzle of the injection device 5 is touched, and the plunger 6 is pressed into the filled resin 16.
Power is applied to the filled resin 16 before it hardens. In addition, the output of the hydraulic cylinder 7 at this time may be about 1/10 to 1/20 of the mold clamping force, and the extrusion stroke of the plunger 6 is limited to the molds 1 and 3, the material resin,
Although it varies depending on the molding conditions, it is usually about 0.01 to 0.2 mm.
また圧力の付与は、一般には最初は小さな圧力
で次に大きくするが、内部応力を特に減したいと
きには、まず電磁リリーフバルブV3の設定圧を
低圧にして一次的に行い、次に高圧に設定した押
圧力調整バルブV2の圧力範囲にて二次的に行
い、最後に再び低圧にする。 In addition, pressure is generally applied at a small pressure at first and then increased, but if you want to particularly reduce internal stress, first set the pressure on the electromagnetic relief valve V 3 to a low pressure, temporarily apply it, and then set it to a high pressure. This is performed secondarily within the pressure range of the pressure adjustment valve V 2 , and finally the pressure is reduced to low again.
さらにまた油圧シリンダー７の作動は、射出圧
力の保圧切換信号よりの計時によつて行う。上記
保圧切換信号は、射出プランジヤの位置または射
出圧力がプレツシヤモニターの設定圧に達したと
き、或は型内圧センサーが設定圧を感知したとき
に発信される。そして油圧シリンダー７の作動時
間もタイマーで制御するとともに、万一作動中に
プランジヤ６が設定位置を越えて異常に前進し、
充填樹脂１６を必要以上に押圧するようなときに
は、設定位置より前進しかかつたときに、上記検
出器１３が働いて油圧シリンダー７の作動を自動
的に停止する。 Furthermore, the hydraulic cylinder 7 is operated by timing based on the injection pressure holding pressure switching signal. The holding pressure switching signal is transmitted when the position of the injection plunger or the injection pressure reaches the set pressure of the pressure monitor, or when the mold internal pressure sensor senses the set pressure. The operating time of the hydraulic cylinder 7 is also controlled by a timer, and in the unlikely event that the plunger 6 abnormally advances beyond the set position during operation,
If the filled resin 16 is pressed more than necessary, the detector 13 is activated to automatically stop the operation of the hydraulic cylinder 7 when the hydraulic cylinder 7 is about to advance beyond the set position.
上記のごとくし圧力を付与された充填樹脂１６
では、ノズルタツチによつてゲートと射出装置１
５の射出シリンダー１５ａとが連絡していること
から、内部圧力はゲートから射出シリンダー側へ
と逃出する。このゲートからの圧力の逃出は可動
キヤビテイにおける押圧力と射出シリンダー１５
ａの保圧力によつて制御し、また可動キヤビテイ
の押圧力は、油圧シリンダー７の油圧を多段に変
化させることによつて適当に調整する。 Filled resin 16 applied with combing pressure as described above
Now, use the nozzle touch to connect the gate and injection device 1.
Since the injection cylinder 15a of No. 5 is in communication with the injection cylinder 15a, the internal pressure escapes from the gate to the injection cylinder side. The release of pressure from this gate is due to the pressing force in the movable cavity and the injection cylinder 15.
The pressure of the movable cavity is controlled by the holding force of a, and the pressing force of the movable cavity is appropriately adjusted by changing the oil pressure of the hydraulic cylinder 7 in multiple stages.
上記のように内部圧力を減じて成形した光学部
品１４は、歪となる残留圧力が除かれることか
ら、高精度となり、特に光透過部１４ｂには歪が
生じない。 The optical component 14 molded with reduced internal pressure as described above has high precision because the residual pressure that causes distortion is removed, and in particular, no distortion occurs in the light transmitting portion 14b.
この発明は上述のように、ノズルタツチした状
態において、金型内の充填樹脂に圧力を付与し、
充填樹脂の内部圧力をゲートより射出シリンダー
側に逃出させるとともに、押圧力と保圧力とのバ
ランスにより応力を均等化して成形品の歪の原因
となる残留圧力を除去したことから、残留内部歪
が非常に少ない成形品が得られ、光学部品等にあ
つては不可欠な表面の平滑度が非常に良好とな
る。またフレネルレンズなどの凹凸面を精密に成
形でき、ウエルドラインを消去することもでき
る。さらにまた高速で低温成形することが可能で
あるから、精密成形を能率よく行うことができる
などの特長を有する。 As mentioned above, this invention applies pressure to the resin filled in the mold when the nozzle is touched,
The internal pressure of the filled resin is released from the gate to the injection cylinder side, and the stress is equalized by the balance between the pressing force and holding force, and the residual pressure that causes distortion of the molded product is removed, thereby reducing the residual internal distortion. A molded product with very little oxidation can be obtained, and the surface smoothness, which is essential for optical parts, etc., is very good. In addition, it is possible to precisely mold the uneven surfaces of Fresnel lenses, etc., and it is also possible to eliminate weld lines. Furthermore, since high-speed and low-temperature molding is possible, precision molding can be carried out efficiently.
図面はこの発明の射出成形方法を実施し得る装
置を例示するもので、第１図は成形完了時におけ
る縦断平面図、第２図は押圧用油圧シリンダーの
回路図、第３図は成形品の斜視図である。
１……固定金型、３……可動金型、５……型締
板、６……プランジヤ、７……押圧用の油圧シリ
ンダー、８……押圧用のラム、１４……光学部
品、１５……射出装置、１５ａ……射出シリンダ
ー、１６……充填樹脂、V1……切換バルブ、V2
……押圧力調整バルブ、V3……電磁リリーフバ
ルブ。
The drawings illustrate an apparatus that can carry out the injection molding method of the present invention, and FIG. 1 is a vertical cross-sectional plan view when molding is completed, FIG. 2 is a circuit diagram of a hydraulic cylinder for pressing, and FIG. 3 is a diagram of a molded product. FIG. 1... Fixed mold, 3... Movable mold, 5... Mold clamping plate, 6... Plunger, 7... Hydraulic cylinder for pressing, 8... Ram for pressing, 14... Optical component, 15 ... Injection device, 15a ... Injection cylinder, 16 ... Filled resin, V 1 ... Switching valve, V 2
...Press force adjustment valve, V3 ...Solenoid relief valve.
Claims (1)
射出充填したのち、射出シリンダーをノズルタツ
チしたまま金型の一部を可動して充填樹脂に押圧
力を付与し、その圧力により射出時に生じた充填
樹脂中の不当な圧力をゲートから射出シリンダー
側に逃出させるとともに、ゲートからの圧力の逃
出を上記押圧力と射出シリンダー側の保圧力とに
より制御してなることを特徴とする射出成形方
法。1 After injecting and filling the molten resin into a mold that is completely and strongly closed, a part of the mold is moved while the nozzle is still touching the injection cylinder to apply pressing force to the filled resin, and this pressure causes the injection to occur during injection. Injection molding characterized in that undue pressure in the filled resin is released from the gate to the injection cylinder side, and the release of the pressure from the gate is controlled by the above-mentioned pressing force and the holding force on the injection cylinder side. Method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2597380A JPS56121748A (en) | 1980-02-29 | 1980-02-29 | Injection molding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2597380A JPS56121748A (en) | 1980-02-29 | 1980-02-29 | Injection molding method |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15932285A Division JPS6183016A (en) | 1985-07-19 | 1985-07-19 | Injection and compression molding machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56121748A JPS56121748A (en) | 1981-09-24 |
| JPS6160764B2 true JPS6160764B2 (en) | 1986-12-22 |
Family
ID=12180665
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2597380A Granted JPS56121748A (en) | 1980-02-29 | 1980-02-29 | Injection molding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56121748A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63150553U (en) * | 1987-03-25 | 1988-10-04 |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60242028A (en) * | 1984-04-11 | 1985-12-02 | Mitsubishi Heavy Ind Ltd | Injection compression molding method |
| JPH0763983B2 (en) * | 1986-07-16 | 1995-07-12 | 大日本印刷株式会社 | Injection molding method and apparatus for molded article having concave portion on surface |
| US9395470B2 (en) | 2012-04-05 | 2016-07-19 | Canon Kabushiki Kaisha | Molded-article manufacturing method, mold, and optical element including fresnel lens |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4872259A (en) * | 1971-12-29 | 1973-09-29 | ||
| DE2614213A1 (en) * | 1976-04-02 | 1977-10-20 | Ver Foerderung Inst Kunststoff | Injection-moulding of thick-walled, large-volume mouldings - by effecting successive pressure impulses during a post-pressure phase, on the compressible moulding cpd. in the mould |
| JPS556054A (en) * | 1978-06-30 | 1980-01-17 | Nippon Kokan Kk <Nkk> | Intermediate wall assembly method for low-temperature double-shell tank |
-
1980
- 1980-02-29 JP JP2597380A patent/JPS56121748A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63150553U (en) * | 1987-03-25 | 1988-10-04 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56121748A (en) | 1981-09-24 |
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