JP3368328B2 - Mold for injection compression molding of thermoplastic resin and injection compression molding method using the mold - Google Patents
Mold for injection compression molding of thermoplastic resin and injection compression molding method using the moldInfo
- Publication number
- JP3368328B2 JP3368328B2 JP19227295A JP19227295A JP3368328B2 JP 3368328 B2 JP3368328 B2 JP 3368328B2 JP 19227295 A JP19227295 A JP 19227295A JP 19227295 A JP19227295 A JP 19227295A JP 3368328 B2 JP3368328 B2 JP 3368328B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- thermoplastic resin
- compression molding
- injection
- injection compression
- 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
Links
Landscapes
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、熱可塑性樹脂の射出圧
縮成形用金型、及びその金型を使用した射出圧縮成形方
法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for injection compression molding of thermoplastic resin, and an injection compression molding method using the mold.
【０００２】[0002]
【従来の技術】熱可塑性樹脂の射出成形技術としては、
成形品形状に対応したキャビティ内に熱可塑性樹脂（溶
融樹脂）を射出充填し、そのまま固化を待つ通常の射出
成形方法と、キャビティが成形品形状と一致する寸前で
可動側金型を待機させて溶融樹脂を射出充填した後、キ
ャビティが成形品形状と一致するまで可動側金型を移動
し、圧縮を加える射出圧縮成形方法とが知られている。
成形時に加圧する後者の射出圧縮形成方法は、樹脂の配
向や成形収縮等に伴なって生ずる反り、ヒケ、変形等の
防止に有効な手段であり、近年注目されている技術であ
るが、単に圧縮を加えるだけでは、圧縮時に、キャビテ
ィ内に充填された溶融樹脂がゲートから逆流し、圧縮効
果が損なわれて反りやヒケ、変形等の発生防止に対する
効果が不充分となり、板状部ではその影響が顕著に現わ
れるし、ランナやスプルー部の樹脂が加圧されて金型離
れが悪くなってしまう。ゲート部が固化してから圧縮を
行なえば逆流を阻止できるが、その時点では、キャビテ
ィの内表面に接触しているスキン層は固化が始まってい
るため、圧縮効果が不充分となる。又、キャビティ内へ
の樹脂の供給量によって、厚みが変動する問題もある。
そこで従来において、例えば特開昭５７−９５４２９号
公報に記載の如く、固定側金型にゲート遮断ピンを設
け、そのゲート遮断ピンでゲートをその内方部位で閉塞
することによって溶融樹脂の逆流を防止する手段が提案
されている。2. Description of the Related Art As a thermoplastic resin injection molding technique,
Injection molding of thermoplastic resin (molten resin) into the cavity corresponding to the shape of the molded product, waiting for solidification as it is, the normal injection molding method, and making the movable mold stand by just before the cavity matches the shape of the molded product An injection compression molding method is known in which, after injection filling with a molten resin, a movable side mold is moved and compression is applied until the cavity matches the shape of the molded product.
The latter injection compression molding method in which pressure is applied during molding is a means effective in preventing warpage, sink marks, deformation, etc. that occur with the orientation and molding shrinkage of the resin, and is a technology that has been drawing attention in recent years. If only compression is applied, the molten resin filled in the cavity will flow back from the gate during compression, and the compression effect will be impaired, and the effect of preventing warpage, sink marks, deformation, etc. will be insufficient, The effect is noticeable, and the resin in the runner and sprue is pressed, and the mold separation becomes worse. The backflow can be prevented by performing compression after the gate portion is solidified, but at that point, the skin layer in contact with the inner surface of the cavity begins to solidify, and the compression effect becomes insufficient. There is also a problem that the thickness varies depending on the amount of resin supplied into the cavity.
Therefore, conventionally, as described in, for example, Japanese Patent Application Laid-Open No. 57-95429, a gate blocking pin is provided on the fixed mold, and the gate blocking pin closes the gate at its inner portion to prevent the reverse flow of the molten resin. Preventive measures have been proposed.
【０００３】[0003]
【発明が解決しようとする課題】固定側金型にゲート遮
断ピンを設けると、固定側金型が大型化してしまうと共
に、射出流路が長くなるので、その流路内で温度低下を
起こして樹脂の流動性が悪くなるし、取り出された成形
品には、ゲート部の一部が付着している。又、ゲートの
遮断タイミングがずれたり、可動側金型の位置決め精度
が低いと、キャビティ内の圧力不足や、逆に圧力過多を
招くといった問題があり、位置決め精度を向上させるた
めには膨大な費用を要する。If the gate blocking pin is provided on the fixed side mold, the fixed side mold becomes large and the injection flow path becomes long, so that the temperature is lowered in the flow path. The fluidity of the resin deteriorates, and a part of the gate portion is attached to the molded product taken out. In addition, if the gate cutoff timing is shifted or the positioning accuracy of the movable die is low, there is a problem that the pressure in the cavity becomes insufficient and conversely excessive pressure occurs. Requires.
【０００４】[0004]
【課題を解決するための手段】本発明は、ピンホールを
有するか、又は有していても支障のない熱可塑性樹脂成
形品の成形時における圧縮効果を高めることを目的とし
たもので、その構成は、熱可塑性樹脂成形品の外形形状
に対応するキャビティを、可動側金型と固定側金型とで
形成可能とすると共に、成形操作において、前記可動側
金型を、金型が完全閉塞されて前記キャビティが成形品
形状に一致する第１の位置から、それより手前にあた
り、金型が僅かに開いた第２の位置まで退避可能とした
射出圧縮成形用金型であって、前記固定側金型に、樹脂
を射出導入するためのピンゲートを設ける一方、可動側
金型の前記ピンゲートに対向した面に、可動側金型が第
１の位置とその直前の位置である第３の位置との間にあ
るとき、ピンゲートの射出口を閉塞する固定ピンを突設
した熱可塑性樹脂の射出圧縮成形用金型と、その金型を
使用し、可動側金型を第３の位置と第２の位置との間に
おける任意位置にしてキャビティ内へ熱可塑性樹脂を射
出した後、可動側金型を第１の位置まで移動させること
によって、固定ピンでピンゲートの射出口を閉塞すると
共に、樹脂に圧縮力を加える熱可塑性樹脂の射出圧縮成
形方法とにある。そしてそれら射出圧縮成形用金型及び
射出圧縮成形方法は、板状部を備え、その板状部にピン
ホールを有している熱可塑性樹脂成形品に好適であり、
前記射出圧縮成形方法では、任意の位置を第２の位置近
傍とし、射出された熱可塑性樹脂の圧力で可動側金型を
第２の位置まで退避させたり、任意の位置を第２の位置
とし、成形機の操作により、一旦金型を閉じた後、強制
的に可動側金型を第２の位置まで退避させることができ
る。DISCLOSURE OF THE INVENTION The present invention is intended to enhance the compression effect at the time of molding of a thermoplastic resin molded product having a pinhole or having no trouble, The structure is such that a cavity corresponding to the outer shape of the thermoplastic resin molded product can be formed by the movable side mold and the fixed side mold, and in the molding operation, the movable side mold is completely closed by the mold. A mold for injection compression molding which is retractable from a first position where the cavity corresponds to the shape of the molded product to a second position where the mold is slightly opened and located in front of the fixed position. The side mold is provided with a pin gate for injecting and injecting resin, while the movable mold has a first position and a third position which is a position immediately before the movable mold on a surface of the movable mold facing the pin gate. When it's between A mold for injection compression molding of a thermoplastic resin in which a fixing pin that closes the injection port is provided, and the mold is used, and the movable side mold is located at an arbitrary position between the third position and the second position. After injecting the thermoplastic resin into the cavity by moving the movable side mold to the first position, the fixing pin closes the injection port of the pin gate, and at the same time the thermoplastic resin that applies compressive force to the resin Injection compression molding method. And the injection compression molding die and the injection compression molding method are suitable for a thermoplastic resin molded article having a plate-shaped portion and having a pinhole in the plate-shaped portion,
In the injection compression molding method, an arbitrary position is set in the vicinity of the second position, the movable side mold is retracted to the second position by the pressure of the injected thermoplastic resin, or the arbitrary position is set as the second position. By operating the molding machine, it is possible to forcibly retract the movable side mold to the second position after closing the mold once.
【０００５】[0005]
【作用】可動側金型が第３の位置に到達すると、固定ピ
ンがピンゲートの射出口を閉塞し、ノズルに至る流路が
ピンゲートとキャビティとの境界で遮断されるので、取
り出される成形品からは一切の付属物がなくなるし、圧
縮時、加圧力はキャビティ内に封じ込められ、射出され
た樹脂組成物に対して１００％作用する。そして流路内
には圧縮力が作用しないので、ランナやスプルー部へ圧
縮力の影響は殆どない。又ピンゲートの閉塞タイミング
は、可動側金型の位置に連動し、必ず可動側金型が第３
の位置に到達した時に閉塞されるから、加圧力は常に一
定し、成形品の厚みにはバラツキはない。When the movable mold reaches the third position, the fixed pin closes the injection port of the pin gate and the flow path to the nozzle is blocked at the boundary between the pin gate and the cavity, so that the molded product taken out from Has no attachments, and the compression force is contained in the cavity during compression, and acts 100% on the injected resin composition. Since the compressive force does not act in the flow passage, the compressive force hardly affects the runner and the sprue portion. Also, the closing timing of the pin gate is interlocked with the position of the movable side mold, and the movable side mold is always the third
Since it is closed when it reaches the position, the pressing force is always constant and there is no variation in the thickness of the molded product.
【０００６】[0006]
【実施例】本発明に係る熱可塑性樹脂の射出圧縮成形用
金型、及びその金型を使用した射出圧縮成形方法を図面
に基づいて説明する。図１は、図２に示す成形品１を形
成するための射出圧縮成形用金型を示したもので、成形
品１は、正方形の基板１ａ裏面の対向する側縁に、丈の
低い側板１ｂ，１ｂが垂下形成され、基板１ａの中心に
ピンホール２を有した蓋状を呈している。図１の射出圧
縮成形用金型において、３は可動側金型としての下型で
あり、可動側取付板４によって成形機の可動盤（図示せ
ず）に固定され、その下型３は上面中央に凹部５を有
し、その凹部５には、底面の両サイドに前記成形品１の
側板１ｂ，１ｂに対応した段部５ａ，５ａが設けられ、
成形品の厚さより深く形成されている。そして前記段部
５ａ，５ａの各底部には、エジェクタピン６，６・・が
配置されている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A mold for injection compression molding of a thermoplastic resin according to the present invention and an injection compression molding method using the mold will be described with reference to the drawings. FIG. 1 shows an injection compression molding die for forming the molded product 1 shown in FIG. 2, in which the molded product 1 has a side plate 1b having a short length on the opposite side edges of the back surface of the square substrate 1a. , 1b are formed so as to hang down, and have a lid shape having a pinhole 2 at the center of the substrate 1a. In the injection compression molding die of FIG. 1, 3 is a lower die as a movable side die, which is fixed to a movable plate (not shown) of a molding machine by a movable side mounting plate 4, and the lower die 3 is an upper surface. The recess 5 is provided in the center, and the recess 5 is provided with step portions 5a, 5a corresponding to the side plates 1b, 1b of the molded article 1 on both sides of the bottom surface.
It is formed deeper than the thickness of the molded product. Ejector pins 6, 6 ... Are arranged at the bottoms of the steps 5a, 5a.
【０００７】７は、固定側金型としての上型であり、固
定側取付板８によって成形機の固定盤（図示せず）に固
定され、その上型７の下面中央には、前記凹部５に嵌合
し、完全に押し込んだ状態で、成形品形状に忠実なキャ
ビティを形成する隆起部９を有し、更に、その隆起部の
中央下面に開口したピンゲート１０の射出口と、その射
出口に連通するランナ１１、及びスプルー１２とから成
る射出流路が形成されている。そして、成形機の可動盤
を押し上げることによって、これに固定された下型３を
上昇させて隆起部９を凹部５に嵌合させれば、図３に示
すように、下型３と上型７とによってキャビティ１３が
形成される。又、前記下型３は、金型が閉じられ、キャ
ビティ１３が成形品形状と一致する第１の位置Ｐ1 に正
確に位置決めできると共に、金型を僅かに開かせた第２
の位置Ｐ2 に至る任意位置まで退避可能となっていて、
エジェクタピン６は、その先端が下型３の凹部５におけ
る段部５ａの底面と同じ高さから凹部５（キャビティ１
３）内に突出可能になっている。更に、前記下型３の中
心には、その下型３が第１の位置Ｐ1 に極めて近い位置
にあるとき、ピンゲート１０の射出口に嵌合してピンゲ
ート１０の射出口を閉塞する固定ピン１４が突設されて
いる。Reference numeral 7 denotes an upper die as a fixed-side die, which is fixed to a fixed plate (not shown) of a molding machine by a fixed-side mounting plate 8, and the recess 5 is provided at the center of the lower surface of the upper die 7. Has a raised portion 9 that forms a cavity faithful to the shape of the molded product in a state where it is completely pushed in, and further has an injection port of a pin gate 10 opened at the central lower surface of the protrusion and its injection port. An injection flow path including a runner 11 and a sprue 12 that communicate with each other is formed. Then, by pushing up the movable plate of the molding machine, the lower mold 3 fixed to this is raised, and the raised portion 9 is fitted into the concave portion 5, as shown in FIG. The cavity 13 is formed by 7 and. In addition, the lower mold 3 can be accurately positioned at the first position P 1 in which the mold 13 is closed so that the cavity 13 matches the shape of the molded product, and the second mold is slightly opened.
It is possible to retract to any position up to the position P 2 of
The tip of the ejector pin 6 is located at the same height as the bottom surface of the step 5a in the recess 5 of the lower mold 3 so that the recess 5 (cavity 1
3) Can be projected inside. Further, at the center of the lower die 3, when the lower die 3 is in a position extremely close to the first position P 1 , a fixing pin that fits into the ejection opening of the pin gate 10 and closes the ejection opening of the pin gate 10. 14 is projected.
【０００８】このように形成された成形用金型は、下型
３を第１の位置Ｐ1 に位置決めして金型を閉塞し、キャ
ビティ１３が成形品形状に一致した状態と、下型３を第
２の位置Ｐ2 に位置決めして金型を開いた状態との間を
移動させることによりキャビティ１３のボリュームを連
続的に増減でき、又、下型３を第１の位置Ｐ1 に近付け
ることにより、その第１の位置Ｐ1 直前で、固定ピン１
４の先端でピンゲート１０の射出口が閉塞される。尚、
前記スプルー１１及びランナ１２とから成る射出流路に
は、図示しない射出シリンダが接続される。In the molding die thus formed, the lower die 3 is positioned at the first position P 1 to close the die, and the cavity 13 conforms to the shape of the molded product, and the lower die 3 The volume of the cavity 13 can be continuously increased or decreased by moving the mold to the second position P 2 and moving the mold to the open position, and the lower mold 3 is brought closer to the first position P 1 . As a result, immediately before the first position P 1 , the fixing pin 1
The injection port of the pin gate 10 is closed at the tip of 4. still,
An injection cylinder (not shown) is connected to the injection flow path including the sprue 11 and the runner 12.
【０００９】次にこのように形成された射出圧縮成形用
金型を使用した熱可塑性樹脂の成形方法を説明する。先
ず下型３が固定された成形機の可動盤を上昇させ、エジ
ェクタピン１４が没入状態にある下型３を、第１の位置
Ｐ1 と第２の位置Ｐ2 との間にあたる任意位置で待機さ
せ、キャビティ１３内に溶融樹脂を射出してキャビティ
１３内を溶融樹脂で充満させ、その樹脂の圧力で下型３
を第２の位置Ｐ2 まで下降させる（図４のａ）。又、型
締位置の制御が可能な成形機を使用する場合、型締によ
り一旦可動側金型を第１の位置Ｐ1 まで移動させた後、
成形機の操作により強制的に可動側金型を後退させるな
どの方法で、可動側金型を第２の位置Ｐ2 に位置決め
し、その状態でキャビティ１３内に溶融樹脂を射出充填
する方法を採用することもできる。この場合、より正確
な可動側金型の位置決めと、充填される樹脂量の制御が
可能になる。次に下型３を第１の位置Ｐ1 側に押し出す
と、最初は溶融樹脂の一部が射出流路内に押し戻される
が、下型３が、第１の位置Ｐ1 の直前である第３の位置
Ｐ3に到達すると、固定ピン１４がピンゲート１０に嵌
合し、射出口が閉塞されてキャビティ１３は密封される
（図４のｂ）。その後下型３が第１の位置Ｐ1 に到達す
るまでは、固定ピン１４の先端部はピンゲート１０内に
深く挿入され、キャビティ内に封じ込められた溶融樹脂
が圧縮される（図４のｃ）。このようにして、下型が第
１の位置直前の第３の位置に到達すると、射出流路がキ
ャビティとの境にあたる射出口で遮断され、キャビティ
内の樹脂の逃げ道はなくなるので、圧縮力は１００％作
用する。樹脂が固化したら下型３が固定されている可動
盤を下降させて金型を開き、エジェクタピン６を突出さ
せて成形品１を取り出し、同時に上型を分割して、成形
品１から切り離されたスプルー及びランナ部１５を取り
出す（図５）。この方法によれば、成形品のピンホール
部周囲にウエルドラインが発生しないし、固定ピンでゲ
ートを閉塞する際、ピンホールの形成と同時に、成形品
はゲート部と切り離されるから、ピンホールの穿設やゲ
ート部の切断工程を省略できる。Next, a method of molding a thermoplastic resin using the injection compression molding die thus formed will be described. First, the movable platen of the molding machine to which the lower mold 3 is fixed is raised, and the lower mold 3 in which the ejector pins 14 are retracted is moved to an arbitrary position between the first position P 1 and the second position P 2. The molten resin is injected into the cavity 13 by making it stand by, the cavity 13 is filled with the molten resin, and the lower mold 3 is pressed by the pressure of the resin.
Is lowered to the second position P 2 (a in FIG. 4). Further, when a molding machine capable of controlling the mold clamping position is used, after the movable mold is once moved to the first position P 1 by the mold clamping,
A method in which the movable-side mold is positioned at the second position P 2 by, for example, forcibly retracting the movable-side mold by operating the molding machine, and the molten resin is injected and filled into the cavity 13 in that state It can also be adopted. In this case, more accurate positioning of the movable mold and control of the amount of resin to be filled can be performed. Next, when the lower mold 3 is extruded to the first position P 1 side, a part of the molten resin is first pushed back into the injection flow path, but the lower mold 3 is immediately before the first position P 1 . When the position P 3 of 3 is reached, the fixed pin 14 is fitted into the pin gate 10, the injection port is closed, and the cavity 13 is sealed (b in FIG. 4). After that, until the lower die 3 reaches the first position P 1 , the tip of the fixing pin 14 is deeply inserted into the pin gate 10 and the molten resin enclosed in the cavity is compressed (c in FIG. 4). . In this way, when the lower mold reaches the third position immediately before the first position, the injection flow path is blocked at the injection port that is the boundary with the cavity, and there is no escape path for the resin in the cavity. It works 100%. When the resin is solidified, the movable platen to which the lower mold 3 is fixed is lowered to open the mold, the ejector pins 6 are projected, and the molded product 1 is taken out. At the same time, the upper mold is divided and separated from the molded product 1. Remove the sprue and runner portion 15 (FIG. 5). According to this method, no weld line is generated around the pinhole portion of the molded product, and when the gate is closed by the fixing pin, the molded product is separated from the gate portion at the same time when the pinhole is formed. It is possible to omit the step of drilling and cutting the gate portion.
【００１０】このように本発明の装置では、下型を第２
の位置側から第１の位置側に向かって移動する過程で、
キャビティ内の溶融樹脂を射出流路内に押し戻し、キャ
ビティが所定のボリュームとなる第３の位置に達する
と、ゲートが閉塞されるから、溶融樹脂の射出時におけ
る下型の位置は気にする必要はなく、又ゲートが閉塞さ
れるタイミングも常に一定しているので、金型の位置決
め精度が低い型締装置であっても、精度の高い成形品を
成形できる。そして本発明の方法においては、キャビテ
ィ内に溶融樹脂を射出し始める時と射出終了時における
下型の位置は実施例に限定されず、射出時に第１の位置
にして射出圧により第２の位置まで押し戻したり、第２
の位置の手前まで押し戻し、そこで待機させるようにし
てもかまわない。As described above, in the apparatus of the present invention, the lower die is the second
In the process of moving from the position side of to the first position side,
When the molten resin in the cavity is pushed back into the injection channel and the cavity reaches the third position where it has a predetermined volume, the gate is closed, so it is necessary to pay attention to the position of the lower mold when injecting the molten resin. Moreover, since the timing of closing the gate is always constant, it is possible to mold a molded product with high accuracy even with a mold clamping device with low mold positioning accuracy. In the method of the present invention, the position of the lower mold at the time of injecting the molten resin into the cavity and at the time of injecting the molten resin is not limited to that of the embodiment, and the first position is set at the time of injection to the second position by the injection pressure. Back to the second,
You may push it back to the position before and wait there.
【００１１】前記実施例の方法により成形された成形品
を、従来の方法で形成した比較データを例示する。熱可
塑性樹脂組成物としては、ガラス繊維を３０重量％配合
した液晶ポリマを使用した。Comparative data of the molded product molded by the method of the above-mentioned embodiment by the conventional method will be illustrated. A liquid crystal polymer containing 30% by weight of glass fiber was used as the thermoplastic resin composition.
【表１】 [Table 1]
【００１２】この表から、圧縮を伴なう射出圧縮成形方
法は、圧縮を伴なわない射出成形方法よりも成形収縮率
が少なくなるので、反り変形量、ヒケ量共、良好な結果
が確認され、その圧縮を伴なう射出圧縮成形方法の中で
も、ゲートを閉塞する本発明の方法で形成された成形品
は、反りやヒケ量が少なくなり、精度アップに効果的で
あることがわかる。本発明の方法を利用すれば、キャビ
ティのボリュームが一定の値になったときゲートが遮断
されて圧縮作用が働くため、待機及び退避位置がどこで
あっても圧縮効果は常に一定する。又キャビティ内の樹
脂が硬化し始める前に圧縮作用が働くため、冷却及び結
晶化によって生ずる体積減少が最小となり、成形収縮率
が大きい結晶性樹脂に最適といえ、特に、板状部を備
え、その板状部にピンホールを有した成形品に好適であ
る。From this table, it is confirmed that the injection compression molding method with compression has a smaller molding shrinkage rate than the injection molding method without compression, so that the warp deformation amount and the sink amount are good. It can be seen that among the injection compression molding methods accompanied with the compression, the molded product formed by the method of the present invention for closing the gate has less warpage and sink amount and is effective in improving accuracy. When the method of the present invention is used, when the volume of the cavity reaches a constant value, the gate is shut off and the compression action works, so that the compression effect is always constant regardless of the standby and retract positions. In addition, since the compression action works before the resin in the cavity begins to harden, the volume reduction caused by cooling and crystallization is minimized, and it can be said that it is most suitable for crystalline resin with a large molding shrinkage ratio, especially with a plate-like portion, It is suitable for a molded product having a pinhole in its plate portion.
【００１３】前記実施例では、下型が可動側金型で、上
型が固定側金型となっているが、固定側金型と固定側金
型の配置は実施例に限定されず、金型構造も、成形品の
形状等に応じ、本発明の前記目的が達成される範囲内に
おいて適宜変更できる。尚本発明において、射出口の位
置は、成形品に形成され、或は形成されていても支障の
ないピンホールの位置により決定され、形成可能な成形
品には、ピンホールを有することが必須ではあるが、ピ
ンホールを埋める加工を追加すれば、ピンホールを有し
ない成形品への応用も可能となる。又、ピンホールを有
する板状部ばかりでなく、貫通孔を有した筒状体にも適
用できる。更に、ピンホールの径には制限はなく、本発
明のピンゲートは、穴形状であるもの一切を包含する。In the above embodiment, the lower mold is the movable mold and the upper mold is the fixed mold, but the arrangement of the fixed mold and the fixed mold is not limited to the embodiment, and The mold structure can also be appropriately changed within the range where the above-mentioned object of the present invention is achieved, depending on the shape of the molded product. In the present invention, the position of the injection port is determined by the position of the pinhole formed in the molded product or the position of the pinhole which does not hinder the formation, and it is essential that the moldable product has the pinhole. However, if a process of filling the pinhole is added, it can be applied to a molded product having no pinhole. Further, it can be applied not only to a plate-shaped portion having a pinhole but also to a cylindrical body having a through hole. Further, there is no limitation on the diameter of the pinhole, and the pingate of the present invention includes all that have a hole shape.
【００１４】[0014]
【発明の効果】本発明の金型によれば、下型に突設され
ている固定ピンによりノズルが閉塞されるので、閉塞と
同時にピンホールの形成とゲートカットとが完了し、圧
縮時には、射出されたキャビティ内の溶融樹脂をスプル
ー側に逆流させることを防止できる。そして本発明の方
法によれば、キャビティ内の加圧力を逃がすことがなく
なり、又ゲートの閉塞タイミングは、溶融樹脂の射出タ
イミングに関係なく極めて正確で、而も圧縮効果が最大
限生かされ、精度の高い成形品を提供できる。よって可
動側金型の位置決め精度が低い成形機であっても、精度
が高く、均一した成形品の生産が可能となる。According to the mold of the present invention, since the nozzle is closed by the fixing pin protruding from the lower mold, the formation of the pinhole and the gate cut are completed at the same time when the nozzle is closed. It is possible to prevent the molten resin in the injected cavity from flowing back to the sprue side. Further, according to the method of the present invention, the pressing force in the cavity is not released, and the gate closing timing is extremely accurate regardless of the molten resin injection timing, and the compression effect is maximized and the accuracy is improved. It is possible to provide high-quality molded products. Therefore, even with a molding machine in which the positioning accuracy of the movable die is low, it is possible to produce a molded product with high accuracy and uniformity.
【図１】 本発明に係る成形用金型の説明図である。FIG. 1 is an explanatory view of a molding die according to the present invention.
【図２】 成形される成形品の形状を示す説明図であ
る。FIG. 2 is an explanatory view showing the shape of a molded product to be molded.
【図３】 成形用金型の動作説明図である。FIG. 3 is an operation explanatory view of a molding die.
【図４】 ａ，ｂ，ｃは成形方法の工程を示す説明図で
ある。4A, 4B, and 4C are explanatory views showing steps of a molding method.
【図５】 成形品の取り出し操作を示す説明図である。FIG. 5 is an explanatory view showing an operation of taking out a molded product.
１・・成形品、１ａ・・基板、１ｂ・・側板、２・・ピ
ンホール、３・・下型、４・・可動側取付板、５・・凹
部、５ａ・・段部、６・・エジェクタピン、７・・上
型、８・・固定側取付板、９・・隆起部、１０・・ピン
ゲート、１１・・ランナ、１２・・スプルー、１３・・
キャビティ、１４・・固定ピン、１５・・スプルー及び
ランナ部、Ｐ1 ・・第１の位置、Ｐ2 ・・第２の位置、
Ｐ3 ・・第３の位置。1 ... Molded product, 1a ... Substrate, 1b ... Side plate, 2 ... Pinhole, 3 ... Lower mold, 4 ... Movable side mounting plate, 5 ... Recess, 5a ... Step, 6 ... Ejector pin, 7 ・ ・ Upper mold, 8 ・ ・ Fixed side mounting plate, 9 ・ ・ Raised part, 10 ・ ・ Pin gate, 11 ・ ・ Runner, 12 ・ ・ Sprue, 13 ・ ・
Cavity, 14 ··· fixing pin, 15 · · · sprue and runner portion, P 1 · · 1st position, P 2 · · 2nd position,
P 3 ... 3rd position.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平２−86420（ＪＰ，Ａ) 特開 平８−281714（ＪＰ，Ａ) 特開 平８−20050（ＪＰ，Ａ) 特開 昭47−25255（ＪＰ，Ａ) 特開 平４−246523（ＪＰ，Ａ) 特開 平４−35922（ＪＰ，Ａ) 特開 平６−278166（ＪＰ，Ａ) 特開 昭62−16119（ＪＰ，Ａ) 特開 昭57−95429（ＪＰ，Ａ) 特開 平８−323813（ＪＰ，Ａ) 実開 平６−17919（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) B29C 45/56 B29C 45/26 B29C 45/38 B29C 45/70 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-2-86420 (JP, A) JP-A-8-281714 (JP, A) JP-A-8-20050 (JP, A) JP-A-47- 25255 (JP, A) JP-A-4-246523 (JP, A) JP-A-4-35922 (JP, A) JP-A-6-278166 (JP, A) JP-A-62-16119 (JP, A) JP-A-57-95429 (JP, A) JP-A-8-323813 (JP, A) Fukukaihei 6-17919 (JP, U) (58) Fields investigated (Int.Cl. 7 , DB name) B29C 45/56 B29C 45/26 B29C 45/38 B29C 45/70
Claims (5)
るキャビティを、可動側金型と固定側金型とで形成可能
とすると共に、成形操作において、前記可動側金型を、
金型が完全閉塞されて前記キャビティが成形品形状に一
致する第１の位置から、それより手前にあたり、金型が
僅かに開いた第２の位置まで退避可能とした射出圧縮成
形用金型であって、前記固定側金型に、樹脂を射出導入
するためのピンゲートを設ける一方、可動側金型の前記
ピンゲートに対向した面に、可動側金型が第１の位置と
その直前の位置である第３の位置との間にあるとき、ピ
ンゲートの射出口を閉塞する固定ピンを突設したことを
特徴とする熱可塑性樹脂の射出圧縮成形用金型。1. A cavity corresponding to the outer shape of a thermoplastic resin molded article can be formed by a movable side mold and a fixed side mold, and in the molding operation, the movable side mold is
A mold for injection compression molding which can be retracted from a first position where the mold is completely closed and the cavity matches the shape of the molded product to a second position where the mold is slightly opened and the mold is slightly opened. Then, the fixed side mold is provided with a pin gate for injecting and injecting resin, while the movable side mold is provided at a first position and a position immediately before it on a surface of the movable side mold facing the pin gate. A mold for injection compression molding of a thermoplastic resin, characterized in that a fixing pin is provided so as to close the injection port of the pin gate when the pin is located between the third position and the third position.
え、その板状部にピンホールを有している請求項１に記
載した熱可塑性樹脂の射出圧縮成形用金型。2. The mold for injection compression molding of a thermoplastic resin according to claim 1, wherein the thermoplastic resin molded product has a plate-shaped portion, and the plate-shaped portion has a pinhole.
を使用し、可動側金型を第３の位置と第２の位置との間
における任意位置にしてキャビティ内へ熱可塑性樹脂を
射出した後、可動側金型を第１の位置まで移動させるこ
とによって、固定ピンでピンゲートの射出口を閉塞する
と共に、樹脂に圧縮力を加える熱可塑性樹脂の射出圧縮
成形方法。3. The injection compression molding mold according to claim 1 is used, and the movable mold is set to an arbitrary position between the third position and the second position, and thermoplastic resin is introduced into the cavity. After injection, the movable side mold is moved to the first position to close the injection port of the pin gate with the fixed pin and to apply compression force to the resin.
し、射出された熱可塑性樹脂の圧力で可動側金型を第２
の位置まで退避させる請求項３に記載した熱可塑性樹脂
の射出圧縮成形方法。4. The movable position mold is moved to the second position by the pressure of the injected thermoplastic resin, with the arbitrary position being in the vicinity of the second position.
The injection compression molding method for thermoplastic resin according to claim 3, wherein the thermoplastic resin is retracted to the position.
機の操作により、一旦金型を閉じた後、強制的に可動側
金型を第２の位置まで退避させる請求項３に記載した熱
可塑性樹脂の射出圧縮成形方法。5. The method according to claim 3, wherein the arbitrary position is set to the second position, the mold is closed once by operating the molding machine, and then the movable mold is forcibly retracted to the second position. Method for injection compression molding of thermoplastic resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19227295A JP3368328B2 (en) | 1995-07-27 | 1995-07-27 | Mold for injection compression molding of thermoplastic resin and injection compression molding method using the mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19227295A JP3368328B2 (en) | 1995-07-27 | 1995-07-27 | Mold for injection compression molding of thermoplastic resin and injection compression molding method using the mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0939046A JPH0939046A (en) | 1997-02-10 |
| JP3368328B2 true JP3368328B2 (en) | 2003-01-20 |
Family
ID=16288522
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19227295A Expired - Fee Related JP3368328B2 (en) | 1995-07-27 | 1995-07-27 | Mold for injection compression molding of thermoplastic resin and injection compression molding method using the mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3368328B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6016579B2 (en) * | 2012-10-29 | 2016-10-26 | キヤノン株式会社 | unit |
| JP6264907B2 (en) * | 2014-01-31 | 2018-01-24 | 東洋製罐グループホールディングス株式会社 | Injection molded product having a bottomed cylindrical shape and molding method |
-
1995
- 1995-07-27 JP JP19227295A patent/JP3368328B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0939046A (en) | 1997-02-10 |
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