JPH1076555A - Method for injection molding of plastic molded article with partly thin part and mold used for injection molding - Google Patents
Method for injection molding of plastic molded article with partly thin part and mold used for injection moldingInfo
- Publication number
- JPH1076555A JPH1076555A JP23524096A JP23524096A JPH1076555A JP H1076555 A JPH1076555 A JP H1076555A JP 23524096 A JP23524096 A JP 23524096A JP 23524096 A JP23524096 A JP 23524096A JP H1076555 A JPH1076555 A JP H1076555A
- Authority
- JP
- Japan
- Prior art keywords
- movable core
- mold
- cooling
- thin
- injection molding
- 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
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、一部に薄肉部を有
するプラスチック製品の射出成形方法とこの方法の実施
に用いられるプラスチック製品の射出成形用金型に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for injection-molding a plastic product partially having a thin portion and a mold for injection-molding a plastic product used in the method.
【0002】[0002]
【従来の技術】プラスチックの成形品において、一部が
薄肉であったり、或いは穴があると不均一な樹脂の流動
によってウェルドが生じる。こうしたウェルドは、成形
品の外観を悪くするだけではなく、ウェルド部の強度は
他の部分に比べて劣るため、極端な薄肉部が出ないよう
に成形品を設計しなければならないなど制限がある。
又、薄肉部の位置や成形品肉厚によっては、樹脂が未充
填となるために、このような場合には成形品を何点かの
パーツに分けて成形し、後から接着する等の二次加工が
必要となる。2. Description of the Related Art In a molded plastic product, if a part of the molded product is thin or has a hole, a non-uniform resin flow causes welding. Such welds not only deteriorate the appearance of the molded product, but also have a limitation in that the strength of the welded portion is inferior to other parts, so that the molded product must be designed so as not to have an extremely thin portion. .
Also, since the resin is not filled depending on the position of the thin portion and the thickness of the molded product, in such a case, the molded product is divided into several parts and molded, and then bonded later. Next processing is required.
【0003】しかし、コスト低減や軽量化の面からは、
最近の成形品においては肉厚は薄く、さらには薄肉部や
厚肉部が混在する等複雑な形状のものが多くなってい
る。こうした傾向は、ウェルド部を更に成長させ、成形
品強度を低下させる。さらに、各種パーツを一体化する
ために、一度で射出成形しようとすると、薄肉部へ樹脂
が充填されず、それを改善しようとしてさらに充填圧力
を高くすれば、反りなどの新たな外観不良が発生する。
また、金型のキャビティ温度を上げて、ウェルドを抑え
るようにすると、成形サイクルが長くなったり、取り出
し後の反りが問題となる。However, in terms of cost reduction and weight reduction,
In recent molded products, the thickness is thin, and the shape of a complicated shape such as a mixture of a thin portion and a thick portion is increasing. Such a tendency further increases the weld portion and lowers the strength of the molded product. Furthermore, when trying to perform injection molding all at once to integrate various parts, the resin is not filled in the thin part, and if the filling pressure is further increased to improve it, new appearance defects such as warpage will occur I do.
In addition, when the cavity temperature of the mold is raised to suppress the weld, the molding cycle becomes longer, and the warpage after the removal becomes a problem.
【0004】これらの問題を解決するために、特開昭6
3−295228号、特開昭63−302013号、特
開平2−92607号、特開平2−141219号、特
開平3−39219号、特開平5−8262号公報に
は、薄肉成形に関する手法やウェルドを発生させないで
成形する手法が明示されている。これらの手法は、キャ
ビティ内に進退可能な薄肉成形用のコアを有する金型を
用いて成形するものである。又、単にコアを進退させる
だけではなく、特開平3−112616号公報には、加
振、振動させながらコアをキャビティ内の樹脂に挿入す
るようにした金型も示されている。In order to solve these problems, Japanese Patent Laid-Open No.
JP-A-3-295228, JP-A-63-302013, JP-A-2-92607, JP-A-2-141219, JP-A-3-39219 and JP-A-5-8262 disclose techniques and welds relating to thin-wall molding. The method of forming without causing the generation is specified. In these methods, molding is performed using a mold having a thin-wall molding core that can advance and retreat in a cavity. Further, in addition to simply moving the core forward and backward, JP-A-3-112616 discloses a mold in which the core is inserted into the resin in the cavity while being vibrated and vibrated.
【0005】[0005]
【発明が解決しようとする課題】しかし、例えば必要と
する成形品の肉厚が極めて薄い場合や、薄肉にする部分
がゲートに近い部分と遠い部分に離れて存在する場合な
どでは、可動コアの前進以前に、固定側及び可動側にス
キン層が発達し、薄肉部形成を妨げる結果となる。ま
た、加振、加圧によって薄肉部を形成させる方法におい
ては、可動コアの樹脂に対するせん断応力が緩和されて
キャビティ内へ前進し易くなるが、薄肉部形成を妨げる
スキン層の発達を抑えることは出来ない。また、比較的
スキン層の発達していない、すなわち樹脂充填中にコア
を前進させる場合においては、薄肉部の形成は容易にな
るものの、成形品の品質は可動コアの挿入タイミング等
によって不安定となる。また、高速で樹脂を充填する場
合についても同様である。更に、高温のキャビティ内で
射出成形を行った場合については、成形サイクルが長く
なってしまうなどの問題が発生し、効率よく薄肉部を形
成することが出来ない。以上のように、成形品の一部に
効率よく薄肉部を形成するためには、スキン層の発達を
抑制する必要がある。However, for example, when the thickness of a required molded product is extremely thin, or when a portion to be thinned exists in a portion close to the gate and a portion far from the gate, for example, the movable core has a large thickness. Prior to advancing, skin layers develop on the fixed and movable sides, resulting in impeding the formation of thin sections. In addition, in the method of forming a thin portion by vibration and pressure, the shear stress of the movable core against the resin is eased and the movable core is easily advanced into the cavity, but the development of the skin layer that hinders the formation of the thin portion cannot be suppressed. Can not. Also, when the skin layer is relatively undeveloped, that is, when the core is advanced during resin filling, the formation of the thin portion is easy, but the quality of the molded product is unstable due to the insertion timing of the movable core. Become. The same applies to the case where the resin is filled at a high speed. Further, when injection molding is performed in a high-temperature cavity, problems such as a long molding cycle occur, and a thin-walled portion cannot be formed efficiently. As described above, it is necessary to suppress the development of the skin layer in order to efficiently form a thin portion in a part of a molded product.
【0006】[0006]
【課題を解決するための手段】本発明者は、可動コアを
用いてプラスチック成形品の一部に薄肉部を形成する射
出成形方法及びこの成形に用いられる金型において、ス
キン層を発達させない手法を鋭意研究した結果、次の方
法と金型を用いることにより、効果的にスキン層の発達
を抑制し、結果としてウェルドの発生を防止できること
が判った。この方法及び金型の構成上の要点は次のとお
りである。Means for Solving the Problems The present inventor has proposed an injection molding method for forming a thin portion in a part of a plastic molded product using a movable core, and a method for preventing a skin layer from developing in a mold used for this molding. As a result of extensive studies, it was found that the use of the following method and mold effectively suppressed the development of the skin layer, and as a result, prevented the occurrence of weld. The points of this method and the configuration of the mold are as follows.
【0007】1.プラスチック射出成形用金型内に可動
コアを組み込み、樹脂充填後直ちにこの可動コアを一定
距離まで前進させてここに薄肉部を成形する射出成形方
法において、前記可動コア内に加熱手段と冷却手段を組
み込み、金型内への樹脂充填と可動コアの前進時に前記
加熱手段を駆動して可動コアを発熱させることにより薄
肉部の樹脂を加熱し、金型の冷却時に前記冷却手段を駆
動して薄肉部を冷却することにより、スキン層の発達を
抑制しながら行う一部に薄肉部を有するプラスチック成
形品を射出成形する方法。[0007] 1. In the injection molding method of incorporating a movable core in a plastic injection mold and immediately moving the movable core to a certain distance after filling with a resin to form a thin portion here, a heating means and a cooling means are provided in the movable core. By incorporating the resin into the mold and moving the movable core forward, the heating means is driven to generate heat in the movable core to heat the resin in the thin portion, and when the mold is cooled, the cooling means is driven to drive the thin portion to reduce the thickness. A method of injection-molding a plastic molded product having a thin part in part while cooling the part to suppress the development of the skin layer.
【0008】2.一部に薄肉部を有するプラスチック成
形品の射出成形用金型において、該金型の一部に前進及
び後退可能なように薄肉部成形用の可動コアを組み込む
と共に、この可動コア内に加熱手段と冷却手段を組み込
み、製品成形時に前記加熱手段を駆動し、冷却時に前記
冷却手段を駆動することにより、スキン層の発達を抑制
するように構成した一部に薄肉部を有するプラスチック
成形品の射出成形用金型。[0008] 2. In a mold for injection molding of a plastic molded product having a thin part in a part, a movable core for molding a thin part is incorporated in a part of the mold so as to be able to advance and retreat, and heating means is provided in the movable core. Injection of a plastic molded article having a thin part in a part configured to suppress the development of the skin layer by driving the heating means during product molding and driving the cooling means during cooling to incorporate the cooling means Mold for molding.
【0009】3.加熱手段として可動コア内に電気ヒー
タを組み込み、冷却手段として可動コア内に冷媒循環流
路を形成して成る前記2記載の一部に薄肉部を有するプ
ラスチック成形品の射出成形用金型。3. 3. A mold for injection molding a plastic molded product having a thin part in part as described in the above item 2, wherein an electric heater is incorporated in the movable core as a heating means, and a refrigerant circulation channel is formed in the movable core as a cooling means.
【0010】4.加熱手段及び冷却手段として、可動コ
ア内に熱媒循環流路を形成し、加熱時にこの熱媒循環流
路内に熱媒を循環させ、冷却時に冷媒を循環させるよう
に構成して成る前記2記載の一部に薄肉部を有するプラ
スチック成形品の射出成形用金型。[0010] 4. A heating medium circulating passage is formed in a movable core as a heating means and a cooling means, and a heating medium is circulated in the heating medium circulating passage during heating, and a refrigerant is circulated during cooling. A mold for injection molding of a plastic molded product having a thin portion in a part of the description.
【0011】5.可動コアを組み込んだ金型と対向する
金型側に加熱手段と冷却手段を組み込んだ補助コアを組
み込み、この補助コアと可動コアの作用により薄肉部を
成形するように構成して成る前記2又は3又は4記載の
一部に薄肉部を有するプラスチック成形品の射出成形用
金型。5. An auxiliary core incorporating a heating means and a cooling means is incorporated on the mold side opposite to the mold incorporating the movable core, and the thin portion is formed by the action of the auxiliary core and the movable core. 5. A mold for injection molding a plastic molded product having a thin part in part according to 3 or 4.
【0012】6.補助コアを可動コアの前進に合わせて
前進させることにより、薄肉部を成形品の肉厚の中間に
形成するように構成した前記5記載の一部に薄肉部を有
するプラスチック成形品の射出成形用金型。6. The injection molding of a plastic molded article having a thin part in part as described in the above item 5, wherein the thin part is formed in the middle of the thickness of the molded article by advancing the auxiliary core in accordance with the advance of the movable core. Mold.
【0013】7.可動コア又は補助コアと金型との間に
断熱材を配置して成る前記項2又は3又は4又は5又は
6記載の一部に薄肉部を有するプラスチック成形品の射
出成形用金型。7. 7. A mold for injection molding of a plastic molded product having a thin part in a part according to item 2 or 3, wherein a heat insulating material is arranged between the movable core or the auxiliary core and the mold.
【0014】[0014]
【作用】射出成形において、キャビティ内に樹脂を充填
する工程及び可動コアを前進させる工程において、可動
コア内の加熱手段を駆動すると、この加熱手段により可
動コアは高温に保持されて、可動コアと接する周囲の樹
脂、特に可動コアの先端面であって薄肉部を形成する部
分の樹脂が加熱される。そして、金型の冷却工程におい
ては、可動コア内の冷却手段が駆動されることにより、
薄肉部が冷却される。この作用により、薄肉部に発生す
るスキン層の発達が抑制される。In the injection molding, in the step of filling the resin into the cavity and the step of advancing the movable core, when the heating means in the movable core is driven, the movable core is held at a high temperature by this heating means, and the movable core is connected to the movable core. The surrounding resin in contact therewith, in particular, the resin at the portion forming the thin portion on the distal end surface of the movable core is heated. Then, in the mold cooling step, the cooling means in the movable core is driven,
The thin part is cooled. By this action, the development of the skin layer generated in the thin portion is suppressed.
【0015】[0015]
【発明の実施の形態】本発明に係る一部に薄肉部を有す
るプラスチック成形品の成形用金型には、油圧シリンダ
等の駆動手段により前進と後退を行う可動コアが組み込
まれている。この可動コアは、金型の移動側又は固定側
又はこの双方に組み込みが可能であって、製品の設計に
合わせてその数、位置、大きさ等が決定される。可動コ
アの駆動手段には、油圧シリンダー、エアシリンダー、
或いは駆動モータ等を用いることができる。但し、本発
明において、この駆動手段はタイミング良く可動コアを
前進又は後退させることができる手段であればどのよう
なものでもよい。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A movable core for moving forward and backward by a driving means such as a hydraulic cylinder is incorporated in a mold for molding a plastic molded product having a thin portion in part according to the present invention. The movable cores can be incorporated into the movable side and / or the fixed side of the mold, and the number, position, size, and the like are determined according to the product design. The driving means of the movable core includes a hydraulic cylinder, an air cylinder,
Alternatively, a drive motor or the like can be used. However, in the present invention, this drive means may be any means as long as it can move the movable core forward or backward with good timing.
【0016】可動コア内に組み込んでこの可動コアを加
熱する手段としては、ジュール熱を利用した棒状抵抗に
よるヒーターであったり、或いは高温油などを熱媒とし
たヒーターであっても構わない。又、薄肉部形成後に可
動コアの冷却のために通す冷媒循環流路は急冷が可能な
ように設計し、ここにシリンダーやポンプ等を用いて冷
媒を循環させる。用いる冷媒としては、窒素や空気など
のガスであったり、或いは水やシリコン油などの液体で
あっても構わない。加熱又は冷却の効果を得るために、
可動コア周辺に断熱材を配置すると良い。但し、この断
熱材は、金型材料としての強度が必要であることから、
例えばセラミックなどが好ましい。The means for heating the movable core incorporated in the movable core may be a heater using a rod-shaped resistance utilizing Joule heat, or a heater using a high-temperature oil or the like as a heat medium. Further, the refrigerant circulation passage for cooling the movable core after the formation of the thin portion is designed so that rapid cooling is possible, and the refrigerant is circulated through a cylinder or a pump here. The refrigerant to be used may be a gas such as nitrogen or air, or a liquid such as water or silicone oil. To get the effect of heating or cooling,
It is good to arrange a heat insulator around the movable core. However, since this heat insulating material needs strength as a mold material,
For example, ceramic is preferable.
【0017】射出成形時に可動コアを加熱するタイミン
グは、樹脂が充填される工程と、可動コアが前進して薄
肉部を形成している工程である。そして、樹脂の充填が
終わると同時に可動コア内に冷媒が循環して可動コアが
急冷され、これにより薄肉部が冷却される。可動コア
は、金型が離れるとき後退する。The timing of heating the movable core during injection molding is a step of filling the resin and a step of moving the movable core forward to form a thin portion. At the same time as the filling of the resin is completed, the refrigerant circulates in the movable core to rapidly cool the movable core, thereby cooling the thin portion. The movable core retracts when the mold leaves.
【0018】[0018]
【実施例1】先ず、金型の実施例を添付の図面に基づい
て説明する。図1は本発明の実施例における金型の基本
構成を示すものである。この金型は、図1で示すよう
に、キャビティ1に対して垂直方向に可動コア2が組み
込まれており、この可動コア2の周囲は、断熱材(セラ
ミック)4と可動部摺動のために隙間があり、更に断熱
材4によって金型主型3と断熱されている。又、可動コ
ア2は図外の油圧シリンダーヘッド等に接続され、金型
外部の油圧源によって、キャビティ1と同一面であった
り、或いは薄肉部を形成するためにキャビティに対して
垂直方向に前進するものである。Embodiment 1 First, an embodiment of a mold will be described with reference to the accompanying drawings. FIG. 1 shows a basic configuration of a mold according to an embodiment of the present invention. In this mold, as shown in FIG. 1, a movable core 2 is incorporated in a direction perpendicular to the cavity 1, and the periphery of the movable core 2 is insulated by a heat insulating material (ceramic) 4 and a movable portion. There is a gap, and the heat insulating material 4 insulates the mold main mold 3. The movable core 2 is connected to a hydraulic cylinder head or the like (not shown), and is advanced by a hydraulic source outside the mold in the same direction as the cavity 1 or in a direction perpendicular to the cavity to form a thin portion. Is what you do.
【0019】図2は実施例1で用いた可動コア2の内部
の構成を示すものである。この可動コア2の内部には、
キャビティ1に近い先端部に、ジュール熱によってコア
を加熱させる、カートリッジヒーター(抵抗体)5が組
み込まれている。更に、可動コア2を冷却するための冷
媒を導くために、可動コア2の内部に冷媒導入管6が挿
入され、この先端には、連結穴8が形成されていて、送
媒口7から流入した冷媒は冷媒導入管6から連絡穴8を
経由して可動コア2内の冷媒循環流路2a内に流出し、
ここを矢印aのように上昇して返媒口9から可動コア2
外に流出し、図示しない冷媒供給源に戻る。FIG. 2 shows the internal structure of the movable core 2 used in the first embodiment. Inside the movable core 2,
A cartridge heater (resistor) 5 for heating the core by Joule heat is incorporated in a tip portion near the cavity 1. Further, a coolant introduction pipe 6 is inserted into the movable core 2 to guide a coolant for cooling the movable core 2, and a connection hole 8 is formed at a tip of the coolant introduction pipe 6. The refrigerant that has flowed out from the refrigerant introduction pipe 6 through the communication hole 8 into the refrigerant circulation flow path 2a in the movable core 2,
The movable core 2 is moved upward as shown by arrow a from the return port 9.
It flows out and returns to a coolant supply source (not shown).
【0020】上記した金型を用いて、可動コアの温度上
昇及び冷却状態について確認を行った。金型主型3は通
常の金型鋼材S55Cを用い、可動コア2の周囲には低
熱伝動性ジルコニアを断熱材4として用いた。金型主型
3の温度は、外部冷温水ユニットで50℃に設定した。
この状態において、可動コア2の内部のカートリッジヒ
ーター(50V−30W)5に通電を開始した。通電開
始から、約15秒後に可動コア2のキャビティ面温度は
約100℃に達し、更にその10秒後には可動コア2の
表面の温度は約130℃に達した。又、更に通電時間を
延ばせば、上昇する傾向にあった。Using the above-mentioned mold, the temperature rise and the cooling state of the movable core were confirmed. The mold main mold 3 was made of a normal mold steel S55C, and zirconia having low thermal conductivity was used as the heat insulating material 4 around the movable core 2. The temperature of the mold main mold 3 was set to 50 ° C. using an external cold / hot water unit.
In this state, power supply to the cartridge heater (50 V-30 W) 5 inside the movable core 2 was started. About 15 seconds after the start of energization, the cavity surface temperature of the movable core 2 reached about 100 ° C., and 10 seconds later, the surface temperature of the movable core 2 reached about 130 ° C. Further, if the energization time is further extended, the tendency tends to increase.
【0021】次に、100℃に加熱された可動コア2内
へ冷媒としての20℃のN2 ガス(10kgf/cm
2 )を注入し、可動コア2の冷却を行った。N2 ガス注
入後約10秒後に可動コア2のキャビティ面温度は65
℃まで降下し、更にその5秒後には55℃まで降下し
た。Next, a 20 ° C. N 2 gas (10 kgf / cm 2) as a refrigerant is introduced into the movable core 2 heated to 100 ° C.
2 ) was injected, and the movable core 2 was cooled. About 10 seconds after the N 2 gas injection, the cavity surface temperature of the movable core 2 becomes 65
C., and 5 seconds later, the temperature dropped to 55.degree.
【0022】[0022]
【実施例2】この実施例2は、可動コア2と金型主型3
が接する面に断熱材4を配置しない例であって、図3で
示すような可動コアの周囲を通常鋼材によって囲まれた
キャビティ1を用い、可動コア2の加熱、冷却を行っ
た。金型主型3は通常の金型鋼材S55Cを用い、金型
主型3の温度は、外部冷温水ユニットで50℃に設定し
た。この状態において、可動コア2の内部のカートリッ
ジヒーター(50V−30W)5に通電を開始した。通
電開始から、約15秒後には75℃、更にその10秒後
には約85℃に達したものの、実施例1と比較すると昇
温速度が遅く、更に、可動コア2近傍の金型主型3の温
度も上昇していた。Embodiment 2 In Embodiment 2, the movable core 2 and the mold main mold 3 are used.
This is an example in which the heat insulating material 4 is not arranged on the surface in contact with the movable core 2, and the movable core 2 is heated and cooled using the cavity 1 in which the movable core is generally surrounded by a steel material as shown in FIG. The mold main mold 3 was made of a normal mold steel material S55C, and the temperature of the mold main mold 3 was set to 50 ° C. by an external cooling / heating water unit. In this state, power supply to the cartridge heater (50 V-30 W) 5 inside the movable core 2 was started. After about 15 seconds from the start of energization, the temperature reached 75 ° C. and further about 10 seconds later, about 85 ° C., but the heating rate was slower than in Example 1, and the mold main mold 3 near the movable core 2 Temperature was also rising.
【0023】次に、約90℃に加熱された可動コア2内
へ、20℃のN2 ガス(10kgf/cm2 )を注入
し、可動コア2の冷却を行った。N2 ガス注入後約10
秒後に可動コア2のキャビティ面の温度は、75℃、更
にその5秒後は68℃であった。この実施例1及び2か
ら、可動コア2を加熱及び冷却手段によって、加熱又は
冷却が出来ることを確認した。しかし、可動コア2の周
辺に、断熱材4を用いない実施例2においては、可動コ
ア2からの放熱が大きく、金型主型3方向へ熱が奪われ
ていることが確認された。したがって、生産サイクルを
短くするためには、断熱材4の配置は必須であるが、生
産サイクルに余裕がある場合は、断熱材4は必ずしも必
要ではない。Next, N 2 gas (10 kgf / cm 2 ) at 20 ° C. was injected into the movable core 2 heated to about 90 ° C. to cool the movable core 2. About 10 after N 2 gas injection
After 2 seconds, the temperature of the cavity surface of the movable core 2 was 75 ° C., and after 5 seconds, 68 ° C. From Examples 1 and 2, it was confirmed that the movable core 2 could be heated or cooled by the heating and cooling means. However, in Example 2 in which the heat insulating material 4 was not used around the movable core 2, it was confirmed that heat dissipation from the movable core 2 was large and heat was taken in the direction of the mold main mold 3. Therefore, in order to shorten the production cycle, the arrangement of the heat insulating material 4 is indispensable, but when there is a margin in the production cycle, the heat insulating material 4 is not necessarily required.
【0024】[0024]
【実施例3】実施例1の金型を用い、部分的に薄肉部を
有する成形品の射出成形を行った。成形品の大きさは3
00mm×300mm、平均肉厚は2.5mmで成形品
中央部に直径Ф20.0mmで厚さ0.10mmの薄肉
部を形成する場合である。実施例1の金型を用いて射出
成形を行うために、キャビティ1内に前進する可動コア
2の駆動源としてФ30mmの油圧シリンダー及び油圧
ユニット(油研工業株式会社製のYA16−C−6−
3.7−14)を用いた。ここで外部油圧ユニット圧力
は100kgf/cm2 とした。射出成形機(東芝機械
株式会社製IS350E)によってキャビティ1は、固
定側主型と可動側主型によって閉じられ、薄肉部を形成
するための可動コア2は、肉厚2.5mmを形成するキ
ャビティ1と同じ面高さにある。樹脂を充填する前、予
め可動コア2を約120℃までカートリッジヒーター
(50V−30W)5で加熱し、ハイインパクトポリス
チレン樹脂(出光石油化学株式会社製HT560)を充
填した。Example 3 Using the mold of Example 1, a molded product having a partially thin portion was injection-molded. The size of the molded product is 3
This is a case where a thin portion having a diameter of 20.0 mm and a thickness of 0.10 mm is formed at the center of a molded product, having a thickness of 00 mm × 300 mm and an average thickness of 2.5 mm. In order to perform injection molding using the mold of Example 1, a hydraulic cylinder and a hydraulic unit (YA16-C-6 manufactured by Yuken Kogyo Co., Ltd.) serving as a drive source of the movable core 2 that advances into the cavity 1 are used.
3.7-14) was used. Here, the external hydraulic unit pressure was 100 kgf / cm 2 . The cavity 1 is closed by a fixed-side main mold and a movable-side main mold by an injection molding machine (IS350E manufactured by Toshiba Machine Co., Ltd.), and the movable core 2 for forming a thin-walled part is a cavity having a thickness of 2.5 mm. It is at the same level as 1. Before filling the resin, the movable core 2 was previously heated to about 120 ° C. with a cartridge heater (50 V-30 W) 5 and filled with a high-impact polystyrene resin (HT560 manufactured by Idemitsu Petrochemical Co., Ltd.).
【0025】次に、キャビティ1全体に樹脂が充填され
た後、油圧シリンダーを動作させて可動コア2をキャビ
ティ1内に前進させた。キャビティ1の前進によって、
可動コア2の前方の樹脂は周囲に押し出され、可動コア
2は0.10mmを形成するために、規定位置2.4m
m前進した位置で停止した。可動コア2が規定位置に達
したと同時に、カートリッジヒーター5への通電を停止
し、代わって可動コア2内へ20℃のN2 ガス(10k
gf/cm2 )を冷媒導入管6より注入し、冷媒循環流
路2a内にN2 ガスを循環させて可動コア2の冷却を行
った。これによって、薄肉部及びその周辺樹脂は急速に
冷却された。その結果、ウェルドを生じない0.10m
mの薄肉部を成形することが出来た。Next, after the entire cavity 1 was filled with resin, the movable core 2 was advanced into the cavity 1 by operating the hydraulic cylinder. By the advance of the cavity 1,
The resin in front of the movable core 2 is extruded to the periphery, and the movable core 2 has a specified position of 2.4 m to form 0.10 mm.
It stopped at the position where it moved forward m. At the same time as the movable core 2 reaches the specified position, the power supply to the cartridge heater 5 is stopped, and instead, N 2 gas (10 k
gf / cm 2 ) was injected from the refrigerant introduction pipe 6, and N 2 gas was circulated in the refrigerant circulation channel 2 a to cool the movable core 2. As a result, the thin portion and its surrounding resin were rapidly cooled. As a result, 0.10m without weld
m was able to be molded.
【0026】[0026]
【実施例4】この実施例は、加熱及び冷却に熱媒を用い
た例であって、図4に示すように、可動コア2内に流体
を熱媒とした場合の熱交換部10を内蔵した金型であ
る。ここで使用する熱媒には、シリコンオイルを用い、
これを図外の高周波誘導加熱装置により、昇温及び冷却
を行い、熱媒入口11から供給した熱媒を前記熱交換部
10を経由して熱媒出口12から高周波誘導装置に戻す
ようにした。成形方法は実施例1の金型を用いた場合と
同様で行った。その結果、実施例3と同様にウェルドを
生じない0.10mmの薄肉部を成形することが出来
た。Embodiment 4 This embodiment is an example in which a heat medium is used for heating and cooling. As shown in FIG. 4, a heat exchange unit 10 in which a fluid is used as a heat medium is built in the movable core 2. Mold. The heat medium used here uses silicone oil,
This was heated and cooled by a high-frequency induction heating device (not shown), and the heat medium supplied from the heat medium inlet 11 was returned to the high-frequency induction device from the heat medium outlet 12 via the heat exchange unit 10. . The molding method was the same as in the case where the mold of Example 1 was used. As a result, it was possible to form a 0.10 mm thin portion in which no weld was formed as in Example 3.
【0027】[0027]
【実施例5】この実施例は、金型において、固定側と移
動側に加熱及び冷却手段を組み込んだ可動コア2及び補
助コア13を組み込んで薄肉部を形成する実施例であっ
て、図5に示すように、可動コア2に対してキャビティ
1を境に相対する部分に、補助コア13を組み込んで、
実施例3と同様に射出成形を行った。この場合、補助コ
ア13の加熱及び冷却の開始については、可動コア2と
同期させた。但し、補助コア13は固定されており、前
進しない。なお、可動コア2と補助コア13の内部構造
(加熱、冷却手段)は実施例1の場合と同様である。そ
の結果、実施例2と同様にウェルドを生じない0.10
mmの薄肉部を成形することが出来た。なお、上記実施
例において、補助コア13側は、加熱及び冷却のタイミ
ングを可動コア2側と同期させているが、このタイミン
グは、薄肉部の成形条件によってはずらしてもよい。Embodiment 5 This embodiment is an embodiment in which a thin portion is formed by incorporating a movable core 2 incorporating heating and cooling means and an auxiliary core 13 on a fixed side and a moving side in a mold. As shown in the figure, an auxiliary core 13 is incorporated in a portion facing the movable core 2 with the cavity 1 as a boundary,
Injection molding was performed in the same manner as in Example 3. In this case, the start of heating and cooling of the auxiliary core 13 was synchronized with the movable core 2. However, the auxiliary core 13 is fixed and does not move forward. The internal structures (heating and cooling means) of the movable core 2 and the auxiliary core 13 are the same as in the first embodiment. As a result, as in the case of Example 2, no weld was generated.
mm thin part could be formed. In the above embodiment, the heating and cooling timings of the auxiliary core 13 are synchronized with the movable core 2, but the timings may be shifted depending on the molding conditions of the thin portion.
【0028】[0028]
【実施例6】この実施例は、前記実施例5において、可
動コア2と共に、補助コア13も同時に前進させたり、
後退させるようにしたものである。この実施例による
と、例えば図6に示すように、薄肉部aを成形品bにお
いて肉厚(W)内に成形することが可能である。この実
施例においても、ウェルドを生じない0.10mmの薄
肉部を成形することが出来た。Embodiment 6 This embodiment is different from Embodiment 5 in that the auxiliary core 13 is advanced simultaneously with the movable core 2,
It is designed to retreat. According to this embodiment, for example, as shown in FIG. 6, it is possible to form a thin portion a into a thickness (W) in a molded product b. Also in this example, it was possible to form a thin portion having a thickness of 0.10 mm which does not cause welding.
【0029】[0029]
【発明の効果】本発明は以上のように、可動コア内に加
熱手段と冷却手段を組み込み、樹脂充填及び可動コア前
進時において、加熱手段を駆動して薄肉部の樹脂を加熱
しながら成形を行い、金型冷却時には冷却手段を駆動さ
せて薄肉部を冷却するようにした。この結果、スキン層
の発達を抑制しながら薄肉部にウェルドを発生させない
成形が可能である。又、可動コア及び補助コアを強制的
に冷却することにより、成形サイクルを短くすることが
できる。As described above, according to the present invention, the heating means and the cooling means are incorporated in the movable core, and when the resin is filled and the movable core is advanced, the heating means is driven to heat and mold the thin-walled resin. Then, at the time of cooling the mold, the cooling means was driven to cool the thin portion. As a result, it is possible to perform molding that suppresses the development of the skin layer and does not generate weld in the thin portion. Further, by forcibly cooling the movable core and the auxiliary core, the molding cycle can be shortened.
【図1】本発明の実施例1における金型キャビティ部の
横断面図。FIG. 1 is a cross-sectional view of a mold cavity according to a first embodiment of the present invention.
【図2】実施例1における可動コア内部構成の横断面
図。FIG. 2 is a cross-sectional view of the internal configuration of the movable core according to the first embodiment.
【図3】実施例2における金型キャビティ部の横断面
図。FIG. 3 is a cross-sectional view of a mold cavity portion according to a second embodiment.
【図4】実施例4における加熱及び冷却に熱媒を用いた
場合の金型キャビティ部、可動コア内部の横断面図。FIG. 4 is a cross-sectional view of a mold cavity portion and the inside of a movable core when a heating medium is used for heating and cooling according to a fourth embodiment.
【図5】実施例5における補助コアを用いた金型キャビ
ティ部、可動コア内部の横断面図。FIG. 5 is a cross-sectional view of a mold cavity portion and an inside of a movable core using an auxiliary core according to a fifth embodiment.
【図6】実施例6における可動コア及び補助コアの双方
を前進させて薄肉部を成形した成形品の説明図。FIG. 6 is an explanatory diagram of a molded product in which both a movable core and an auxiliary core are advanced to form a thin portion in a sixth embodiment.
1 キャビティ 2 可動コア 2a 冷媒循環流路 3 金型主型 4 断熱材 5 カートリッジヒーター 6 冷媒導入管 7 送媒口 8 連絡穴 9 返媒口 10 熱交換部 11 熱媒入口 12 熱媒出口 13 補助コア DESCRIPTION OF SYMBOLS 1 Cavity 2 Movable core 2a Refrigerant circulation channel 3 Mold main mold 4 Insulation material 5 Cartridge heater 6 Refrigerant introduction pipe 7 Transmission medium port 8 Communication hole 9 Return medium port 10 Heat exchange part 11 Heat medium inlet 12 Heat medium outlet 13 Auxiliary core
Claims (7)
アを組み込み、樹脂充填後直ちにこの可動コアを一定距
離まで前進させてここに薄肉部を成形する射出成形方法
において、前記可動コア内に加熱手段と冷却手段を組み
込み、金型内への樹脂充填と可動コアの前進時に前記加
熱手段を駆動して可動コアを発熱させることにより薄肉
部の樹脂を加熱し、金型の冷却時に前記冷却手段を駆動
して薄肉部を冷却することにより、スキン層の発達を抑
制しながら行う一部に薄肉部を有するプラスチック成形
品を射出成形する方法。1. An injection molding method in which a movable core is incorporated in a plastic injection mold, and immediately after filling with a resin, the movable core is advanced to a predetermined distance to form a thin portion here. Means for cooling the thin-walled resin by driving the heating means to generate heat in the movable core when filling the resin into the mold and moving the movable core forward, and for cooling the mold when the mold is cooled. A method of injection-molding a plastic molded product having a thin part in a part while controlling the development of the skin layer by cooling the thin part.
品の射出成形用金型において、該金型の一部に前進及び
後退可能なように薄肉部成形用の可動コアを組み込むと
共に、この可動コア内に加熱手段と冷却手段を組み込
み、製品成形時に前記加熱手段を駆動し、冷却時に前記
冷却手段を駆動することにより、スキン層の発達を抑制
するように構成した一部に薄肉部を有するプラスチック
成形品の射出成形用金型。2. A mold for injection molding of a plastic molded product having a thin part in a part thereof, wherein a movable core for molding a thin part is incorporated into a part of the mold so as to be able to advance and retreat, and the movable core is formed in the mold. A heating means and a cooling means are incorporated in the core, the heating means is driven at the time of product molding, and the cooling means is driven at the time of cooling, so that a part configured to suppress the development of the skin layer has a thin portion. Mold for injection molding of plastic molded products.
を組み込み、冷却手段として可動コア内に冷媒循環流路
を形成して成る請求項2記載の一部に薄肉部を有するプ
ラスチック成形品の射出成形用金型。3. The injection of a plastic molded product having a thin part in part according to claim 2, wherein an electric heater is incorporated in the movable core as heating means, and a refrigerant circulation channel is formed in the movable core as cooling means. Mold for molding.
内に熱媒循環流路を形成し、加熱時にこの熱媒循環流路
内に熱媒を循環させ、冷却時に冷媒を循環させるように
構成して成る請求項2記載の一部に薄肉部を有するプラ
スチック成形品の射出成形用金型。4. A heating medium circulating passage is formed in a movable core as a heating means and a cooling means, and a heating medium is circulated in the heating medium circulating passage during heating, and a refrigerant is circulated during cooling. 3. A mold for injection molding a plastic molded product having a thin part in part according to claim 2.
型側に加熱手段と冷却手段を組み込んだ補助コアを組み
込み、この補助コアと可動コアの作用により薄肉部を成
形するように構成して成る請求項2又は3又は4記載の
一部に薄肉部を有するプラスチック成形品の射出成形用
金型。5. An auxiliary core incorporating a heating means and a cooling means is incorporated into a mold opposite to a mold incorporating a movable core, and a thin portion is formed by the action of the auxiliary core and the movable core. The injection molding die for a plastic molded product having a thin part in a part according to claim 2, 3 or 4.
進させることにより、薄肉部を成形品の肉厚の中間に形
成するように構成した請求項5記載の一部に薄肉部を有
するプラスチック成形品の射出成形用金型。6. A plastic partly having a thin part according to claim 5, wherein the auxiliary core is advanced in accordance with the advance of the movable core so that the thin part is formed in the middle of the thickness of the molded product. Mold for injection molding of molded products.
熱材を配置して成る請求項2又は3又は4又は5又は6
記載の一部に薄肉部を有するプラスチック成形品の射出
成形用金型。7. A heat insulating material is arranged between a movable core or an auxiliary core and a mold.
A mold for injection molding of a plastic molded product having a thin portion in a part of the description.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23524096A JPH1076555A (en) | 1996-09-05 | 1996-09-05 | Method for injection molding of plastic molded article with partly thin part and mold used for injection molding |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23524096A JPH1076555A (en) | 1996-09-05 | 1996-09-05 | Method for injection molding of plastic molded article with partly thin part and mold used for injection molding |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH1076555A true JPH1076555A (en) | 1998-03-24 |
Family
ID=16983163
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP23524096A Pending JPH1076555A (en) | 1996-09-05 | 1996-09-05 | Method for injection molding of plastic molded article with partly thin part and mold used for injection molding |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH1076555A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1488913A2 (en) * | 2003-06-12 | 2004-12-22 | Munekata Co. Ltd. | Welding of thermoplastic resin products. |
JP2005507803A (en) * | 2001-10-25 | 2005-03-24 | ファウンテン パテンツ ベー.フェー.イー.オー. | Method and apparatus for forming thin-walled products and products produced thereby |
JP2007185797A (en) * | 2006-01-11 | 2007-07-26 | Toyoda Gosei Co Ltd | Manufacturing method of air bag cover |
KR101172404B1 (en) | 2005-10-24 | 2012-08-08 | 삼성전자주식회사 | Mold Apparatus and Heater Cartridge for Mold |
-
1996
- 1996-09-05 JP JP23524096A patent/JPH1076555A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005507803A (en) * | 2001-10-25 | 2005-03-24 | ファウンテン パテンツ ベー.フェー.イー.オー. | Method and apparatus for forming thin-walled products and products produced thereby |
EP1488913A2 (en) * | 2003-06-12 | 2004-12-22 | Munekata Co. Ltd. | Welding of thermoplastic resin products. |
EP1488913A3 (en) * | 2003-06-12 | 2007-04-11 | Munekata Co. Ltd. | Welding of thermoplastic resin products. |
KR101172404B1 (en) | 2005-10-24 | 2012-08-08 | 삼성전자주식회사 | Mold Apparatus and Heater Cartridge for Mold |
JP2007185797A (en) * | 2006-01-11 | 2007-07-26 | Toyoda Gosei Co Ltd | Manufacturing method of air bag cover |
JP4677904B2 (en) * | 2006-01-11 | 2011-04-27 | 豊田合成株式会社 | Manufacturing method of airbag cover |
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