JPH0811175A - Plunger for preplastication type injection molding machine - Google Patents
Plunger for preplastication type injection molding machineInfo
- Publication number
- JPH0811175A JPH0811175A JP17983594A JP17983594A JPH0811175A JP H0811175 A JPH0811175 A JP H0811175A JP 17983594 A JP17983594 A JP 17983594A JP 17983594 A JP17983594 A JP 17983594A JP H0811175 A JPH0811175 A JP H0811175A
- Authority
- JP
- Japan
- Prior art keywords
- injection
- plunger
- opening
- nozzle
- hole
- 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
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
- B29C45/53—Means for plasticising or homogenising the moulding material or forcing it into the mould using injection ram or piston
- B29C45/54—Means for plasticising or homogenising the moulding material or forcing it into the mould using injection ram or piston and plasticising screw
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、可塑化部と射出部とを
別設したプリプラ式射出成形機に係り、詳しくは射出室
に材料を滞留させないようにした射出ノズル及び射出室
に加えて、そのプランジャの構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pre-plastic injection molding machine in which a plasticizing part and an injection part are provided separately, and more specifically, in addition to an injection nozzle and an injection chamber in which a material is not retained in the injection chamber. , Concerning the structure of the plunger.
【０００２】[0002]
【従来の技術】一般的なプリプラ式射出成形機を図５を
用いて説明するに、加熱シリンダ１０にスクリュ１１が
挿嵌された射出部１の後方に、該スクリュ１１を回転す
るためのモータ（一般的にはサーボモータ）４０及び図
示していないが油圧駆動部等からなる駆動部４を備え、
該スクリュ１１の回転と図示していないバンドヒータに
よってホッパー８から落下した樹脂を混練して溶融し、
連通路１２を介して射出部２へ、前記溶融した樹脂材料
が送られるようになっている。射出部２は、射出孔３０
を有するノズル３を射出シリンダ３３の前方に有し、該
射出部２の後方には射出用駆動部５が前記可塑化部１と
一体に組立てられ、全体として射出装置が形成されてい
る。この射出用駆動部５は、射出シリンダ５０内でラム
５１、ピストン５２が挿嵌され、該ラム５１によって押
圧油室５３と引戻し油室５４とを形成し、また、該ピス
トン５２は射出プランジャ２１と連結され、該プランジ
ャ２１は射出シリンダ３３の孔３４に摺動可能に挿嵌さ
れるとともに、該プランジャ２１の頭部２２とノズル側
壁面３６及び該孔３４で形成される空所で射出室３５を
形成している。該射出室３５は、前記したように連通路
１２によって可塑化部１と射出部２とを連通し、溶融し
た樹脂はその注入圧力でプランジャ２１を後退させて材
料を蓄積計量する。射出容量は、プランジャ２１の後退
ストロークによって計量されるようになっている。2. Description of the Related Art A general pre-plastic injection molding machine will be described with reference to FIG. 5, in which a motor for rotating a screw 11 behind a injection part 1 in which the screw 11 is fitted is rotated. (Generally, a servomotor) 40 and a drive unit 4 including a hydraulic drive unit (not shown) are provided,
The resin dropped from the hopper 8 is kneaded and melted by the rotation of the screw 11 and a band heater (not shown),
The molten resin material is sent to the injection unit 2 via the communication passage 12. The injection part 2 has an injection hole 30.
The nozzle 3 having the above is provided in front of the injection cylinder 33, and the injection drive unit 5 is integrally assembled with the plasticizing unit 1 behind the injection unit 2 to form an injection device as a whole. In the injection drive unit 5, a ram 51 and a piston 52 are inserted and fitted in an injection cylinder 50, and the ram 51 forms a pressing oil chamber 53 and a withdrawal oil chamber 54, and the piston 52 is attached to the injection plunger 21. And the plunger 21 is slidably fitted in the hole 34 of the injection cylinder 33, and the injection chamber is formed in the void formed by the head 22, the nozzle side wall surface 36 and the hole 34 of the plunger 21. 35 are formed. In the injection chamber 35, the plasticizing portion 1 and the injection portion 2 are communicated with each other by the communication passage 12 as described above, and the molten resin causes the plunger 21 to retreat by its injection pressure to accumulate and measure the material. The injection capacity is measured by the backward stroke of the plunger 21.
【０００３】射出室３５に蓄積された樹脂の射出は、射
出装置を移動用シリンダ７の作動によって、固定盤６に
取付けた（図示していない）金型のスプルにノズル３の
先端３１とを当接（図５では射出装置が前進した状態）
させて、前記押圧油室５３に油圧を供給してプランジャ
２１を前進して行なわせる。このとき、連通路１２に設
置した逆止弁１３を作動させ、スクリュ１１側への樹脂
の逆流を防止するようになっている。この逆止弁１３の
作動に代わって、スクリュ１１の回転を停止して前進さ
せて連通路１２を閉塞する（特公平５−３７８１０号公
報参照）ようにしたものも実施されている。For the injection of the resin accumulated in the injection chamber 35, the tip of the nozzle 3 is attached to the sprue of a mold (not shown) attached to the fixed platen 6 by the operation of the moving cylinder 7 of the injection device. Abutment (Injection device has advanced in Fig. 5)
Then, the hydraulic pressure is supplied to the pressing oil chamber 53 to move the plunger 21 forward. At this time, the check valve 13 installed in the communication passage 12 is operated to prevent the reverse flow of the resin to the screw 11 side. In place of the operation of the check valve 13, the screw 11 is also stopped to rotate and moved forward to close the communication passage 12 (see Japanese Patent Publication No. 5-37810).
【０００４】プリプラ式射出成形機はインライン式射出
成形機と比較して、射出容量や射出圧力を大きくとれる
点で優れているが、溶融材料が滞留しがちなので、熱分
解を起こし易い材料（例えば、ポリカボネート、硬質塩
化ビニール樹脂）には使用できず、また、構造上、材料
替えや色替えに手間がかかるとされている。The pre-plastic injection molding machine is superior to the in-line injection molding machine in that the injection capacity and the injection pressure can be made large, but since the molten material tends to stay, a material that easily causes thermal decomposition (for example, , Polycarbonate, hard vinyl chloride resin), and due to the structure, it takes time and effort to change materials and colors.
【０００５】この構造上の欠点とは、前述した逆止弁１
３の部分で溶融樹脂材料が滞留することと、図６に示す
ように、連通路１２から注入される溶融材料は、射出シ
リンダ３３の孔３４内で、その壁面３６に対して連通路
１２から流出する樹脂が、射出孔３０を中心に孔３４の
内周面に沿うように流路ａ及び外側流路ｂ、ｂを形成し
て注入され、連通路１２の反対側の領域で樹脂溜りを形
成してしまう。そこで、本特許出願人は特開平６−２３
７９６号公報で提案しているように、かかる滞留する樹
脂を早期に排出できるように図っている。This structural defect is due to the above-mentioned check valve 1
The molten resin material stays in the portion 3 and, as shown in FIG. 6, the molten material injected from the communication passage 12 enters the hole 34 of the injection cylinder 33 from the communication passage 12 to the wall surface 36 thereof. The resin flowing out is injected by forming the flow path a and the outer flow paths b, b around the injection hole 30 along the inner peripheral surface of the hole 34, and collects the resin pool in the region on the opposite side of the communication path 12. Will be formed. Therefore, the applicant of the present patent application is Japanese Patent Laid-Open No. 6-23
As proposed in Japanese Patent No. 796, it is intended that the stagnant resin can be discharged at an early stage.
【０００６】すなわち、その要部構成を図３及び図４で
示すように、射出シリンダ３３の前方でノズルアダプタ
３９をそのボルト（図示していない）取付孔３８で締付
け固定され、該ノズルアダプタ３９の一端が、射出室３
５のノズル側壁面３６における、射出孔３０の開口３０
ａを挟んだ連通路１２の開口１２ａと反対側となる領域
に開口３７ａし、他端が射出孔３０に連通する射出副路
３７を設ける。プランジャ２１の前進にともない、射出
室３５内の溶融材料は、射出孔３０からノズル３に導か
れるとともに、前回の射出時に滞留した部分の材料は射
出副路３７を通ってノズル３に導かれるようにして、射
出室３５内に滞留し易い部分の材料を、射出毎に速やか
にノズル３に導く構成としている。That is, as shown in FIGS. 3 and 4, the main structure of the nozzle adapter 39 is fixed in front of the injection cylinder 33 by a bolt (not shown) mounting hole 38, and the nozzle adapter 39 is fixed. One end of the injection chamber 3
5, the opening 30 of the injection hole 30 in the nozzle side wall surface 36
An opening 37a is provided in a region on the opposite side of the opening 12a of the communication passage 12 sandwiching a, and an injection sub-passage 37 having the other end communicating with the injection hole 30 is provided. With the advance of the plunger 21, the molten material in the injection chamber 35 is guided from the injection hole 30 to the nozzle 3, and the material of the portion retained at the previous injection is guided to the nozzle 3 through the injection sub passage 37. Thus, the material of the portion that easily stays in the injection chamber 35 is promptly guided to the nozzle 3 after each injection.
【０００７】ところで、上述したように射出室３５に一
旦蓄積され、計量された材料はプランジャ２１の前進に
より射出孔３０と射出副路３７とを通って、ノズル３に
導かれるが、その射出室３５に蓄積されるときの材料
は、図６に示すようにその壁面３６に対して連通路１２
から射出孔３０を中心にして、かつ孔３４の内周に沿う
ように流路ａ及び外側流路ｂ、ｂを形成しながらプラン
ジャ２１を後退させるから、該連通路１２の開口１２ａ
とは反対側に設けた射出副路３７の開口３７ａ側に蓄積
され、さらには、前記樹脂の圧力により引き退がるプラ
ンジャ２１とその孔３４の摺動隙間に残留した薄皮状の
前回の付着樹脂をも剥離もしくは洗滌して、開口３７ａ
側に蓄積させ、頭部２２の前方に集積される。従って、
経時的に観たとき、プランジャ２１が計量を完了したス
トローク終端で、最も古い樹脂が該プランジャ２１の頭
部２２前方側に集積されて後、射出行程が行なわれるこ
とになる。By the way, as described above, the material once accumulated and measured in the injection chamber 35 is guided by the advance of the plunger 21 to the nozzle 3 through the injection hole 30 and the injection auxiliary passage 37. As shown in FIG. 6, when the material is accumulated in 35, the communication passage 12 is
Since the plunger 21 is retracted while forming the flow passage a and the outer flow passages b, b around the injection hole 30 and along the inner circumference of the hole 34, the opening 12a of the communication passage 12 is formed.
Previously adhered in the form of a thin skin remaining in the sliding gap between the plunger 21 and its hole 34, which accumulates on the side of the opening 37a of the injection sub-passage 37 provided on the side opposite to and is retracted by the pressure of the resin. The resin is also peeled off or washed to form the opening 37a.
It is accumulated on the side and accumulated in front of the head 22. Therefore,
When viewed over time, the injection stroke is performed after the oldest resin is accumulated on the front side of the head 22 of the plunger 21 at the end of the stroke when the plunger 21 has finished weighing.
【０００８】この射出の際に、金型のキャビテイへの充
填初期では、射出室３５から押出される樹脂圧力の方が
高いので、前記のように射出孔３０及び射出副路３７か
ら材料は供給される。しかしながら、材料が金型キャビ
テイ内に充満されるようになると、射出室３５内の樹脂
圧力と金型内の樹脂圧力とが均衡化されてきて、樹脂の
流れも遅くなり、ついで保圧行程に入る。この保圧の
時、一般的には壁面３６と頭部２２との間に１〜５ｍｍ
程度の間隔があるようにして保圧され、キャビテイ内の
適正量の樹脂を圧縮したままの状態で、ゲートシールさ
れるまで保持する。すなわち、保圧時には、前記した孔
３４内を浚えた前回の付着樹脂を、プランジャ２１の前
進によって壁面３６と頭部２２の間に移送して残留さ
せ、保圧終了後、再び計量を始めることとなる。At the time of this injection, the pressure of the resin extruded from the injection chamber 35 is higher at the initial stage of filling the cavity of the die, so that the material is supplied from the injection hole 30 and the injection sub-passage 37 as described above. To be done. However, when the material is filled in the mold cavity, the resin pressure in the injection chamber 35 and the resin pressure in the mold are balanced, the flow of the resin is slowed, and then the pressure holding process is started. enter. At the time of this holding pressure, generally 1 to 5 mm between the wall surface 36 and the head 22.
The pressure is maintained so that there is a certain interval, and an appropriate amount of resin in the cavity is compressed and held until the gate is sealed. That is, at the time of pressure holding, the previously adhered resin that has dredged in the hole 34 is transferred between the wall surface 36 and the head 22 by the advance of the plunger 21 to be left behind, and after the pressure holding is finished, the measurement is restarted. Becomes
【０００９】[0009]
【発明が解決しようとする課題】上述したように、特開
平６−２３７９６号公報に記載された構成とすることに
より、色替えや材料替えをする場合、その成果を達成す
ることができたが、度重ねた実験の結果、熱影響を受け
易いポリアセタールや塩化ビニール樹脂を成形すると、
樹脂容量とも関係するが、成形品によっては老化現象と
観られる変色部が該成形品に稀に観られた。この原因と
しては、前述のように保圧行程前に射出室３５内の樹脂
圧力と金型キャビテイ内の樹脂圧力とが均衡化してき
て、射出孔３０では、その開口３０ａからは射出室３５
内の材料を吸い込むように誘導するが、その圧力の均衡
化によって射出副路３７の開口３７ａ側で材料は流れを
停滞させられ、さらには、保圧時、壁面２６と頭部２２
との間に僅かな間隔を残して保圧状態に入るため、孔３
４内周面を浚えた付着樹脂を該間隔にプランジャ２１の
前進によって移送させ、計量行程が始まって保圧行程が
完了するまでの一射出の間、長時間残留させることが原
因している、と考えられる。また、その行程中に保圧行
程を有するかぎり、計量毎に孔３４内を浚えた前回の付
着樹脂まで残さずに射出することができないこと、特に
プランジャ２１の後退限で蓄積される浚えた前回の付着
樹脂は、該プランジャ２１の前進により、その頭部２２
の前方に経時的には最も古い樹脂を前進させて、充填完
了時に残留させることになる。As described above, by adopting the configuration described in Japanese Patent Laid-Open No. 6-23796, the result can be achieved when changing colors or changing materials. As a result of repeated experiments, when molding polyacetal or vinyl chloride resin, which is easily affected by heat,
Although it is related to the resin capacity, a discolored part which is considered to be an aging phenomenon was rarely seen in the molded product depending on the molded product. The cause of this is that the resin pressure in the injection chamber 35 and the resin pressure in the mold cavity have been balanced before the pressure-holding stroke as described above, and the injection hole 35 is injected from the opening 30a in the injection hole 30.
Although the material inside is guided to be sucked in, the flow of the material is stagnated on the side of the opening 37a of the injection sub-passage 37 due to the pressure equalization.
Since there is a slight gap between the
(4) The reason is that the adhering resin that has drowned the inner peripheral surface is transferred to the interval by the advance of the plunger 21, and is left for a long time during one injection from the start of the measuring process to the completion of the pressure-holding process. it is conceivable that. In addition, as long as there is a pressure-holding stroke in the stroke, it is not possible to inject without leaving even the previously adhered resin drowning in the hole 34 for each measurement, in particular, the drastic last time accumulated in the backward limit of the plunger 21. The adhering resin of the
Will advance the oldest resin over time and will remain on completion of filling.
【００１０】本発明は、特開平６−２３７９６号公報の
発明による成果を、より確実にするようにしたもので、
孔３４内周面を浚えた付着樹脂（以下、残滓という）を
残留させることなく、射出副路３７からノズル３へと優
先して流入させることを目的としている。The present invention is intended to make the results of the invention of JP-A-6-23796 more reliable.
The purpose is to preferentially flow into the nozzle 3 from the injection sub-passage 37 without leaving the adhered resin (hereinafter, referred to as residue) that has drowned the inner peripheral surface of the hole 34.
【００１１】[0011]
【課題を解決するための手段】そこで、本発明は、加熱
シリンダ（１０）内にてスクリュ（１１）を回転して合
成樹脂材料を可塑化する可塑化部（１）と、該可塑化部
（１）から連通路（１２）で連通された射出室（３５）
に前記可塑化された溶融樹脂を蓄積・計量する射出部
（２）と、を備え、該射出部は射出シリンダ（３３）内
に計量された樹脂材料を射出プランジャ（２１）の前進
によって金型に射出するプリプラ式射出成形機であっ
て、前記射出室（３５）のノズル側壁面（３６）の周縁
部に配置された前記連通路（１２）の開口（１２ａ）
と、一端が、前記射出室（３５）のノズル側壁面（３
６）の中央に開口（３０ａ）し、かつ他端が前記ノズル
（３）の射出口（３２）に連通する射出孔（３０）と、
一端が、前記射出室（３５）のノズル側壁面（３６）に
おける、前記射出孔（３０）の開口（３０ａ）を挟んで
前記連通路（１２）の反対となる領域に開口（３７ａ）
し、かつ他端が前記射出孔（３０）に連通する、少なく
とも１個の射出副路（３７）とを備えたプリプラ式射出
成形機用プランジャに係るものである。Therefore, according to the present invention, there is provided a plasticizing section (1) for rotating a screw (11) in a heating cylinder (10) to plasticize a synthetic resin material, and the plasticizing section. The injection chamber (35) communicated with the communication passage (12) from (1)
An injection part (2) for accumulating and measuring the plasticized molten resin, and the injection part ejects the resin material measured in the injection cylinder (33) by advancing the injection plunger (21). A pre-plastic injection molding machine for injecting into the interior of the injection chamber (35), the opening (12a) of the communication passage (12) arranged at the peripheral portion of the nozzle side wall surface (36).
And one end of the nozzle side wall surface (3) of the injection chamber (35).
An injection hole (30) having an opening (30a) in the center of 6) and the other end communicating with the injection port (32) of the nozzle (3);
The one end has an opening (37a) in a region of the nozzle side wall surface (36) of the injection chamber (35) opposite to the communication passage (12) with the opening (30a) of the injection hole (30) interposed therebetween.
In addition, the present invention relates to a plunger for a pre-plastic injection molding machine having at least one injection auxiliary path (37), the other end of which communicates with the injection hole (30).
【００１２】そして、第１の発明は、そのプランジャ頭
部（２２）側中央で前記ノズル（３）側に突出し、かつ
前記射出孔（３０）に挿入可能とした棒状突起（２３）
を形成して、該突起（２３）は前記プランジャ（２１）
が前進して射出充填完了前に前記射出孔（３０）に挿入
されて開口（３０ａ）を閉塞し、前記射出室（３５）に
おける残留し易い残滓を、前記射出副路（３７）から前
記ノズル（３）に導くようにしている。The first aspect of the present invention is a rod-shaped projection (23) projecting toward the nozzle (3) side at the center of the plunger head (22) side and insertable into the injection hole (30).
And the projection (23) forms the plunger (21).
Is advanced to be inserted into the injection hole (30) to close the opening (30a) before completion of injection filling, and the residue easily left in the injection chamber (35) is removed from the injection auxiliary passage (37) to the nozzle. I am trying to lead to (3).
【００１３】また、第２の発明は、前記プランジャ頭部
（２２）側中央で形成した棒状突起（２３）は、太さが
同一直径の円柱もしくはその先端側が細くなるようにし
た截頭円錐状の円柱で形成されている。According to a second aspect of the present invention, the rod-shaped projection (23) formed at the center of the plunger head (22) side is a cylinder having the same diameter or a truncated cone shape in which the tip side is thin. It is formed of a cylinder.
【００１４】[0014]
【作用】上述のように、プランジャ（２１）の頭部（２
２）中央で突出する棒状突起（２３）を設置し、該突起
（２３）は射出孔（３０）に挿入可能な太さであり、か
つ長さは保圧時においては射出孔（３０）に該突起（２
３）先端が挿入される長さを有していることに基づき、
プランジャ（２１）が前進して金型への樹脂充填が充満
状態になる寸前に、換言して、射出室（３５）内の樹脂
圧力と金型内の樹脂圧力とが均衡化される直前に、突起
（２３）の先端が開口（３０ａ）を閉塞状態にし、さら
に、充填が完了して保圧状態になるまでプランジャ（２
１）は前進するので、射出室（３５）内の材料は積極的
に射出副路（３７）の開口（３７ａ）から、該射出副路
（３７）と連通した射出孔（３０）へと進入する。した
がって、残滓は強制的に優先して、前記開口（３７ａ）
から射出副路（３７）及び射出孔（３０）を通じて金型
側へと排出されてしまう。As described above, the head (2) of the plunger (21) is
2) A rod-shaped projection (23) protruding in the center is provided, and the projection (23) has a thickness that can be inserted into the injection hole (30), and the length is set to the injection hole (30) at the time of pressure holding. The protrusion (2
3) Based on that the tip has a length to be inserted,
Immediately before the plunger (21) moves forward to fill the mold with resin, in other words, immediately before the resin pressure in the injection chamber (35) and the resin pressure in the mold are balanced. , The tip of the protrusion (23) closes the opening (30a), and further, the plunger (2
Since 1) advances, the material in the injection chamber (35) positively enters from the opening (37a) of the injection sub-passage (37) into the injection hole (30) communicating with the injection sub-passage (37). To do. Therefore, the residue is forcibly prioritized to the opening (37a).
Is discharged to the mold side through the injection sub-passage (37) and the injection hole (30).
【００１５】さらには、第２の発明では、円柱状の突起
（２３）の形状を変えることによって、射出孔（３０）
に挿入される該突起（２３）は、該射出孔（３０）を直
接通過注入される樹脂の容量を制限し、漸次射出副路
（３７）から射出孔（３０）へと注入される樹脂容量を
増加させ、残滓を万遍なく排出するようにしている。Furthermore, in the second aspect of the invention, the shape of the cylindrical projection (23) is changed so that the injection hole (30) is formed.
The protrusion (23) inserted into the injection hole limits the volume of resin injected directly through the injection hole (30), and the volume of resin injected gradually from the injection auxiliary passage (37) into the injection hole (30). Is increased so that the residue is evenly discharged.
【００１６】なお、上述括弧内の符号は、図面を対照す
るものであるが、何等本発明の構成を限定するものでは
ない。The reference numerals in the above parentheses refer to the drawings, but do not limit the structure of the present invention.
【００１７】[0017]
【実施例】本発明の実施例を図１及び図２に沿って説明
するが、従来例と同一の構成、同一部分については、図
３、図４及び図５を利用して同一符号を用いて詳述する
ことにする。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. 1 and 2. The same components and parts as those of the conventional example are designated by the same reference numerals by using FIGS. 3, 4 and 5. Will be described in detail.
【００１８】まず、可塑化部１は、加熱シリンダ１０及
びスクリュ１１を有しており、該シリンダ１０の後方に
はホッパー８と、該スクリュ１１を回転させるモータ４
０及びスクリュ１１を前進させる油圧装置からなる駆動
部４とを備えている。そして、前記可塑化部１は連通路
１２を介して、射出部２の射出室３５と連通され、ノズ
ル３側の壁面３６に開口１２ａしている。スクリュ１１
の前進は、連通路１２を閉塞させて連通を遮断するとき
に作動されるように構成している。First, the plasticizing section 1 has a heating cylinder 10 and a screw 11, and a hopper 8 behind the cylinder 10 and a motor 4 for rotating the screw 11.
0 and a drive unit 4 including a hydraulic device for moving the screw 11 forward. The plasticizing section 1 is communicated with the injection chamber 35 of the injection section 2 through the communication passage 12, and has an opening 12a in the wall surface 36 on the nozzle 3 side. Screw 11
Is configured to be activated when the communication passage 12 is closed and communication is cut off.
【００１９】射出部２には、ノズル３が取付けられ、前
記壁面３６の中央でノズル３の先端３１側の射出口３２
へと貫通する射出孔３０が開口３０ａし、該開口３０ａ
を挟んで前記連通路１２の開口１２ａの反対側に少なく
とも一個の射出副路３７が開口３７ａしており、該射出
副路３７は壁面３６の外周縁に設置され、その開口３７
ａから傾斜して射出孔３０と連通している。そして、射
出シリンダ３３の孔３４にはプランジャ２１が挿嵌さ
れ、該プランジャ２１は射出用駆動部５と連結され、前
記孔３４とその壁面３６及び該プランジャ２１の頭部２
２とで射出室３５を形成している。A nozzle 3 is attached to the injection part 2, and an injection port 32 on the tip 31 side of the nozzle 3 is provided at the center of the wall surface 36.
The injection hole 30 penetrating to
At least one injection sub-passage 37 is formed on the opposite side of the opening 12a of the communication passage 12 across the opening 37a. The injection sub-passage 37 is installed on the outer peripheral edge of the wall surface 36, and the opening 37
It is inclined from a and communicates with the injection hole 30. Then, the plunger 21 is inserted into the hole 34 of the injection cylinder 33, the plunger 21 is connected to the injection drive unit 5, the hole 34 and its wall surface 36, and the head 2 of the plunger 21.
The injection chamber 35 is formed by 2 and.
【００２０】また、ノズルアダプタ３９は射出シリンダ
３３の前方でその取付孔３８にボルト（図示していな
い）を挿通して締付け固定され、該アダプタ３９にはノ
ズル３が装着されている。このノズルアダプタ３９は、
一側端中心部が凹状に形成されて射出室３５のノズル側
壁面３６を構成しており、該壁面３６の底面はプランジ
ャ２１の頭部２２と同じように円錐状に窪んで形成され
ている。さらに、該ノズルアダプタ３９の中央部分には
射出孔３０が貫通して形成されており、該射出孔３０は
その一端が前記ノズル側壁面３６の中央に開口３０ａし
ているとともに、他端がノズル３の先端３１の射出口３
２に連通している。そして、該ノズルアダプタ３９には
連通路１２が形成されており、該連通路１２は可塑化部
１の加熱シリンダ１０からの連通路１２と整合・連通し
ているとともに、他端がノズル側壁面３６における射出
室３５の周縁部近傍に開口１２ａしている。なお、前記
射出副路３７は射出孔３０に対して傾斜して穿設され、
その射出室３５の周縁近傍に開口３７ａするように形成
されるので、ノズルアダプタ３９に形成する凹所は穿設
加工の加工性からみて、できるだけ浅く形成されること
が望ましい。The nozzle adapter 39 is fixed in front of the injection cylinder 33 by inserting a bolt (not shown) into a mounting hole 38 of the injection cylinder 33, and the nozzle 3 is mounted on the adapter 39. This nozzle adapter 39 is
The central portion of one side end is formed in a concave shape to form a nozzle side wall surface 36 of the injection chamber 35, and the bottom surface of the wall surface 36 is formed in a conical recess similar to the head 22 of the plunger 21. . Further, an injection hole 30 is formed so as to penetrate through the central portion of the nozzle adapter 39, and one end of the injection hole 30 has an opening 30a at the center of the nozzle side wall surface 36 and the other end is the nozzle. Injection port 3 of tip 3 of 3
It communicates with 2. A communication passage 12 is formed in the nozzle adapter 39. The communication passage 12 is aligned with and communicates with the communication passage 12 from the heating cylinder 10 of the plasticizing section 1, and the other end is a nozzle side wall surface. An opening 12 a is formed in the vicinity of the peripheral edge of the injection chamber 35 in 36. The injection sub-path 37 is formed so as to be inclined with respect to the injection hole 30,
Since the opening is formed in the vicinity of the peripheral edge of the injection chamber 35, the recess formed in the nozzle adapter 39 is preferably formed as shallow as possible in view of the workability of the drilling process.
【００２１】そして、ノズルアダプタ３９には、射出孔
３０よりも小径の射出副路３７が穿設され、該射出副路
３７はその一端が、前記ノズル側壁面３６における、前
記射出孔３０の開口３０ａを挟んで、前記連通路１２の
開口１２ａと反対側となる射出室３５の周縁部近傍に開
口３７ａしているとともに、他端が射出孔３０に連通し
ており、かつその間を直線状に斜めに延びている。即
ち、射出副路３７の開口３７ａは、ノズル側壁面３６の
周縁部における、連通路１２の開口１２ａに対して１８
０°離れた位置に開口する。また、この射出副路３７は
図示では前記のように開口１２ａに対して１８０°離れ
た位置に開口３７ａしているが、該開口３７ａを一個に
限らず複数個設ける場合もある。The nozzle adapter 39 is provided with an injection sub-path 37 having a diameter smaller than that of the injection hole 30. One end of the injection sub-path 37 is opened at the nozzle side wall surface 36 of the injection hole 30. An opening 37a is formed in the vicinity of the peripheral edge of the injection chamber 35 on the opposite side of the opening 12a of the communication passage 12 with the opening 30a interposed therebetween, and the other end communicates with the injection hole 30, and the space between them is linear. It extends diagonally. That is, the opening 37 a of the injection sub-passage 37 is 18 times larger than the opening 12 a of the communication passage 12 in the peripheral portion of the nozzle side wall surface 36.
Open at 0 ° apart. Further, although the injection sub-passage 37 is opened at a position 180 ° away from the opening 12a as described above in the drawing, the number of the openings 37a is not limited to one, but a plurality of openings may be provided.
【００２２】また、図１では頭部２２に設けた棒状突起
２３は円柱状に形成し、図２は射出プランジャ２１全体
を図示して、該頭部２２に設けた該突起２３を截頭円錐
状としている。該突起２３を円柱状としたのは、前述の
射出孔３０に該突起２３の先端が開口３０ａを通過する
と直ちに該開口３０ａを閉塞するようにしたものであ
り、該截頭円錐状としたのは、円錐部分が開口３０ａか
ら射出孔３０に進入しても該円錐部分が開口３０ａとの
隙間によって、ある程度その隙間から樹脂を供給できる
ようになっている。該射出プランジャ２１は、ピストン
５２と連結される取付部２５と柄部２４及び頭部２２と
で形成され、該頭部２２に突出する突起２３とで一体に
なっており、該頭部２２の直径Ｄ０は、射出シリンダ３
３の孔３４に摺接して挿嵌できるように僅かに小さい太
さにされ、充分な安定性を保つために頭部２２の長さＭ
を該頭部２２の直径Ｄ０と同等か、それ以上の長さとし
ている。そして、突起２３は、僅かに傾斜する円錐状の
頭部２２の中央に、射出孔３０の直径よりも細い直径ｄ
に形成され、棒状で、長さＮは、プランジャ２１が前進
して射出後に保圧される頭部２２と壁面３６との間隔よ
りも長く、通常保圧時は１〜５ｍｍ程度の間隔であるの
で、それよりも３ｍｍ程度長くしている。また、該頭部
２２の直径Ｄ０よりもやや細い直径Ｄ１とした柄部２４
とで、前方スクレーパー２６と後方スクレーパー２７と
を形成して、該射出プランジャ２１の前進のときは前方
スクレーパー２６によって孔３４内の付着樹脂を掻き取
りを、後退のときは後方スクレーパー２７によって掻き
取るようになっている。さらに、柄部２４は頭部２２よ
りも直径Ｄ１がやや細い直径となっているから、後方ス
クレーパー２７で掻き取られた樹脂は、溶融した軟らか
いうちに堰を作らせないように、該孔３４と該柄部２４
との間で扱くように押出せるようになっている。Further, in FIG. 1, the rod-like projection 23 provided on the head 22 is formed in a cylindrical shape, and FIG. 2 shows the entire injection plunger 21, and the projection 23 provided on the head 22 is truncated cone. I am in a state. The projection 23 has a cylindrical shape so that the opening 30a is immediately closed when the tip of the projection 23 passes through the opening 30a in the injection hole 30 and has a truncated cone shape. Even if the conical portion enters the injection hole 30 through the opening 30a, the conical portion allows the resin to be supplied to some extent through the clearance with the opening 30a. The injection plunger 21 is formed of a mounting portion 25 connected to the piston 52, a handle portion 24 and a head portion 22, and is integrally formed with a protrusion 23 projecting from the head portion 22. Diameter D 0 is for injection cylinder 3
3 has a slightly smaller thickness so that it can be slidably fitted into the hole 34 and the length M of the head 22 is kept to maintain sufficient stability.
Is equal to or longer than the diameter D 0 of the head 22. The protrusion 23 has a diameter d smaller than the diameter of the injection hole 30 at the center of the conical head 22 that is slightly inclined.
Is formed into a rod shape, and the length N is longer than the distance between the head portion 22 and the wall surface 36 where the plunger 21 advances and is held after injection, and is a distance of about 1 to 5 mm during normal pressure holding. Therefore, it is about 3 mm longer than that. Further, the handle portion 24 having a diameter D 1 slightly smaller than the diameter D 0 of the head 22
And the front scraper 26 and the rear scraper 27 are formed, and when the injection plunger 21 is advanced, the front scraper 26 scrapes off the resin adhered in the holes 34, and when the injection plunger 21 is retracted, the rear scraper 27 is scraped off. It is like this. Further, since the handle portion 24 has a diameter D 1 slightly smaller than that of the head portion 22, the resin scraped off by the rear scraper 27 prevents the weir from being formed while it is molten and soft. 34 and the handle 24
It can be pushed out to handle between
【００２３】このプランジャ２１において、棒状の突起
２３は該プランジャ２１の柄部２４及び頭部２２とを一
体的に形成しているが、該突起２３は頭部２１に焼嵌め
によって固定してもよい。焼嵌めに代わって、ネジ固着
によっても一体的にできるが、該プランジャ２１は、常
に射出シリンダ３３内で摺動され、圧力を受ける場合が
多く、目視確認できない該射出シリンダ３３内に挿嵌さ
れているので、柄部２４、頭部２２とともに突起２３は
一体的に切削加工したほうが信頼性が高まる。In this plunger 21, the rod-shaped projection 23 integrally forms the shank 24 and the head 22 of the plunger 21, but the projection 23 may be fixed to the head 21 by shrink fitting. Good. The plunger 21 is always slid in the injection cylinder 33 and is often subjected to pressure, which can be integrated by screw fixing instead of shrink fitting, but is inserted into the injection cylinder 33 which cannot be visually confirmed. Therefore, it is more reliable to integrally machine the protrusion 23 together with the handle 24 and the head 22.
【００２４】本実施例は、以上のような構成からなるの
で、保圧行程にあっては、射出プランジャ２１の頭部２
２前面はノズル側壁面３６から数ｍｍ離れた位置にあ
り、また、突起２３は射出孔３０内に開口３０ａを閉塞
して、該開口３０ａからその先端が数ｍｍ挿入された状
態にあり、キャビテイ内樹脂の冷却にかかわらず、射出
副路３７と連通する射出孔３０へと樹脂圧力を伝達して
所定保圧力を保証し、樹脂の冷却を待つ。そして、該保
圧行程が終了して計量行程に入ると、可塑化部１のスク
リュ１１は回転を始め、該スクリュ１１の回転にともな
って可塑化された樹脂圧力によって該スクリュ１１は後
退して、該スクリュ１１の先端で閉塞していた連通路１
２との接触を解き、開口１２ａから勢い良く溶融樹脂は
注入される。この注入の始めは前記のように突起２３は
射出孔３０にその先端が挿入され、壁面３６と頭部２２
との間は数ｍｍ離れているので、図６に示すように流路
ａ及び外側流路ｂ、ｂが形成され、射出シリンダ３３の
孔３４の内周面、壁面３６及び頭部２２の前面の残留し
た材料を剥離しながら洗滌し、プランジャ２１を後退さ
せる。該プランジャ２１の後退に伴い、突起２３も洗滌
し、前記した流路ａと外側流路ｂ、ｂの流れを維持しな
がらプランジャ２１は後退し、かつプランジャ２１と孔
３４内周面との僅かな摺動隙間に残った薄皮状で、後方
スクレーパー２７で掻き取った残りの前回の付着樹脂
（残滓）も新しい樹脂によって剥離・洗滌されながら、
溶融材料は該プランジャ２１の後退により計量される。Since this embodiment is constructed as described above, the head portion 2 of the injection plunger 21 is held in the pressure-holding stroke.
2 The front surface is located a few mm away from the nozzle side wall surface 36, and the projection 23 closes the opening 30a in the injection hole 30 so that its tip is inserted from the opening 30a by a few mm. Regardless of the cooling of the inner resin, the resin pressure is transmitted to the injection hole 30 communicating with the injection sub-passage 37 to guarantee a predetermined holding pressure, and the resin is waited for cooling. Then, when the pressure-holding step is completed and the metering step is started, the screw 11 of the plasticizing section 1 starts to rotate, and the screw 11 is retracted by the resin pressure plasticized with the rotation of the screw 11. , The communication passage 1 closed at the tip of the screw 11.
The contact with 2 is released, and the molten resin is vigorously injected from the opening 12a. At the beginning of this injection, the tip of the projection 23 is inserted into the injection hole 30 as described above, and the wall surface 36 and the head 22 are inserted.
Since a distance of a few millimeters from each other, a flow path a and outer flow paths b, b are formed as shown in FIG. 6, and the inner peripheral surface of the hole 34 of the injection cylinder 33, the wall surface 36, and the front surface of the head 22 are formed. The remaining material of (1) is washed while being peeled off, and the plunger 21 is retracted. As the plunger 21 retreats, the protrusion 23 is also washed, the plunger 21 retreats while maintaining the flow of the flow passage a and the outer flow passages b, b, and the plunger 21 and the inner peripheral surface of the hole 34 slightly. It is a thin skin remaining in the sliding gap, and the remaining resin (residuals) from the previous scraping with the rear scraper 27 is also peeled and washed by the new resin,
The molten material is metered by retracting the plunger 21.
【００２５】計量行程の終端では、前記保圧行程時に必
要な残留樹脂及び前記計量開始時に剥離・洗滌された樹
脂は開口１２ａの反対側の開口３７ａ側に群をなして集
められ、かつ、プランジャ２１の後退によって該プラン
ジャ２１と孔３４との僅かな摺動隙間に残留させられた
前回の付着樹脂（残滓）も、新しい溶融樹脂で浚えら
れ、頭部２２の前方で開口３７ａ側に集積される。そし
て、プランジャ２１が所定量後退して、計量行程が完了
すると、前述したスクリュ１１の回転を停止するととも
に、駆動部４に油圧を送り、スクリュ１１を前進させて
連通路１２を閉塞する。これにより射出室３５からの可
塑化部１側への逆流は阻止され、押圧油室５３に圧油が
送られ、ラム５１が前進して、射出プランジャ２１も前
進して射出行程に入る。At the end of the measuring process, the residual resin necessary for the pressure-holding process and the resin peeled and washed at the start of the measuring process are collected in groups on the side of the opening 37a opposite to the opening 12a, and The previously adhered resin (residuals) left in the slight sliding gap between the plunger 21 and the hole 34 due to the retreat of 21 is also dredged by the new molten resin and accumulated in front of the head 22 on the side of the opening 37a. To be done. Then, when the plunger 21 retracts by a predetermined amount and the measuring stroke is completed, the rotation of the screw 11 is stopped and the hydraulic pressure is sent to the drive unit 4 to move the screw 11 forward to close the communication passage 12. As a result, backflow from the injection chamber 35 to the plasticizing section 1 side is blocked, pressure oil is sent to the pressing oil chamber 53, the ram 51 advances, and the injection plunger 21 also advances to enter the injection stroke.
【００２６】ついで射出行程にあっては、射出室３５内
の樹脂は、射出プランジャ２１の前進に伴って射出孔３
０に導入され、かつ射出孔３０の開口３０ａを挟んで連
通路開口１２ａの反対側に位置する部分の樹脂は、射出
副路３７を通って射出孔３０に導かれ、そして、これら
樹脂は合流して、ノズル３の先端３１の射出口３２から
金型のキャビテイ内に射出される。この射出のとき、開
口３７ａ付近に集められた前回保圧行程時に残留した樹
脂は、射出副路３７から逸早く射出孔３０へと導かれ射
出される。また、射出プランジャ２１の前進によって、
前方スクレーパー２６は孔３４内周面を掻き取るように
樹脂を浚え、押圧して射出する。Next, in the injection stroke, the resin in the injection chamber 35 is injected into the injection hole 3 as the injection plunger 21 advances.
0, and the resin in the portion located on the opposite side of the communication passage opening 12a with the opening 30a of the injection hole 30 interposed therebetween is guided to the injection hole 30 through the injection auxiliary passage 37, and these resins merge. Then, it is injected into the cavity of the mold from the injection port 32 of the tip 31 of the nozzle 3. At the time of this injection, the resin collected in the vicinity of the opening 37a and remaining in the previous pressure-holding process is quickly guided from the injection sub-passage 37 to the injection hole 30 and is injected. In addition, the forward movement of the injection plunger 21
The front scraper 26 scrapes the resin so as to scrape the inner peripheral surface of the hole 34, presses it, and ejects it.
【００２７】さらに、射出が進むにつれ、頭部２２の前
方で、開口３７ａ側に集積され頭部２２前方にあった孔
３４内周面に付着していた樹脂（残滓）が、該プランジ
ャ２１の前進によって壁面３６に接近してきて、射出副
路３７から射出孔３０へと導入され、ついでには頭部２
２の中央で形成した突起２３が開口３０ａを通過して射
出孔３０内に進入すると、該開口３０ａは閉塞され、開
口３７ａ付近へと接近していた残滓は優先して、積極的
に射出副路３７から射出孔３０へと導かれるようにな
る。この際、射出孔３０より射出副路３７の孔直径が小
さいので、射出充填の完了前で、キャビテイ内にもかな
りの樹脂が注入されており、射出室３５内の樹脂圧力が
均衡化して流量が低下しようとするときでもあるが、該
小さい直径の射出副路３７を主流とするから、保圧から
計量、計量から射出への経時的に見て最も長時間滞留し
ていた残滓は、該射出副路３７を通じてから射出・排出
される。Further, as the injection progresses, the resin (residuals) accumulated on the inner peripheral surface of the hole 34 in front of the head 22 and accumulated on the side of the opening 37a in front of the head 22 of the plunger 21. As it advances, it approaches the wall surface 36 and is introduced into the injection hole 30 from the injection auxiliary passage 37, and then the head 2
When the protrusion 23 formed at the center of the second part 2 passes through the opening 30a and enters the injection hole 30, the opening 30a is closed, and the residue that has approached the vicinity of the opening 37a is given priority and the injection auxiliary is positively performed. It comes to be guided from the passage 37 to the injection hole 30. At this time, since the hole diameter of the injection sub-passage 37 is smaller than that of the injection hole 30, a considerable amount of resin is injected into the cavity before the injection filling is completed, and the resin pressure in the injection chamber 35 is balanced and the flow rate is increased. However, since the injection sub-path 37 having a small diameter is the main flow, the residue that has stayed for the longest time from the holding pressure to the metering and from the metering to the injection is It is ejected and discharged from the injection sub-passage 37.
【００２８】上述実施例では、プランジャ２１の頭部２
２中央部に射出孔３０に対して平行な外周面を有する円
柱状の突起２３とした図１について述べたが、図２に示
すように截頭円錐状の突起２３とすることにより、前記
円柱状の突起２３が開口３０ａから射出孔３０へと進入
すると、該開口３０ａは閉塞されて射出室３５内の樹脂
は射出副路３７へと積極的に流入させられるのに対し
て、該截頭円錐状突起２３は射出孔３０へ進入するに従
い該開口３０ａが絞られ、その進入量によって射出副路
３７への樹脂流量が逐次増加していくようになる。即
ち、射出孔３０へ流通される開口３０ａからの流量を減
少させながら、開口３７ａから射出副路３７を通じて射
出孔３０に導かれる樹脂流量を多くして、残滓を平均的
に射出・排出する。In the above embodiment, the head 2 of the plunger 21 is used.
2 The cylindrical protrusion 23 having an outer peripheral surface parallel to the injection hole 30 at the center has been described with reference to FIG. 1. However, by using the truncated cone-shaped protrusion 23 as shown in FIG. When the columnar projection 23 enters the injection hole 30 through the opening 30a, the opening 30a is closed and the resin in the injection chamber 35 is positively flown into the injection sub-passage 37, whereas the truncated head is formed. The opening 30a of the conical projection 23 is narrowed as it enters the injection hole 30, and the resin flow rate to the injection sub-passage 37 is gradually increased depending on the amount of penetration. That is, while decreasing the flow rate from the opening 30a circulated to the injection hole 30, the flow rate of the resin introduced from the opening 37a to the injection hole 30 through the injection sub-passage 37 is increased to inject and discharge the residue on average.
【００２９】[0029]
【発明の効果】本発明は上記のような構成としているの
で、射出行程がが開始されると、中央の射出孔には射出
孔開口と射出副路開口とから新しい樹脂と、滞留し易い
部分の樹脂とが混合されてノズル側射出孔に導かれ、射
出口から金型キャビテイに供給される。そしてまた、射
出充填が完了する前にプランジャ頭部に設けた突起が射
出孔内に進入して射出孔開口を閉塞するから、残滓も新
しい樹脂とともに射出副路から射出孔へと導かれて、該
射出口から金型に供給されることになる。従って、一射
出毎に射出室内の樹脂は新規な樹脂と入れ替わり、長期
にわたって滞留する樹脂はなくなるから、熱影響を受け
易い材料であっても、老化現象を誘起するような不良原
因は解消でき、また、色替え、材料替えに対しても早期
に処理できる等の効果が得られる。Since the present invention has the above-mentioned structure, when the injection stroke is started, a new resin is apt to stay in the central injection hole from the injection hole opening and the injection auxiliary passage opening. Resin is mixed and guided to the nozzle side injection hole, and is supplied to the mold cavity from the injection port. Also, before the injection filling is completed, the projection provided on the plunger head enters the injection hole and closes the opening of the injection hole, so that the residue is also guided from the injection sub-path to the injection hole together with the new resin, It is supplied to the mold from the injection port. Therefore, the resin in the injection chamber is replaced with a new resin for each injection, and the resin that stays for a long period of time disappears, so even if the material is easily affected by heat, the cause of defects such as aging can be eliminated. In addition, it is possible to obtain an effect such that the color change and the material change can be processed at an early stage.
【図１】本発明のノズルと射出室及びプランジャの部分
を示す断面図。FIG. 1 is a cross-sectional view showing a nozzle, an injection chamber, and a plunger of the present invention.
【図２】本発明のプランジャの実施例の一例を示す図。FIG. 2 is a diagram showing an example of an embodiment of a plunger of the present invention.
【図３】そのノズル側壁面を示す正面図。FIG. 3 is a front view showing the side wall surface of the nozzle.
【図４】従来例のノズルと射出室及びプランジャの部分
を示す断面図。FIG. 4 is a cross-sectional view showing a nozzle, an injection chamber, and a plunger portion of a conventional example.
【図５】従来例の射出装置の全体側面（一部断面）図。FIG. 5 is an overall side view (partially sectional view) of an injection device of a conventional example.
【図６】そのノズル側壁面を示す正面図。FIG. 6 is a front view showing the side wall surface of the nozzle.
１ 可塑化部 ２ 射出部 ３ ノズル １０ 加熱シリンダ １１ スクリュ １２ 連通路 １２ａ （連通路）開口 ２１ （射出）プランジャ ２２ 頭部 ２３ 突起 ３０ 射出孔 ３０ａ （射出孔）開口 ３２ 射出口 ３３ 射出シリンダ ３５ 射出室 ３６ （ノズル側）壁面 ３７ 射出副路 ３７ａ （射出副路）開口 1 Plasticizing Part 2 Injection Part 3 Nozzle 10 Heating Cylinder 11 Screw 12 Communication Passage 12a (Communication Passage) Opening 21 (Injection) Plunger 22 Head 23 Protrusion 30 Injection Hole 30a (Injection Hole) Opening 32 Injection Port 33 Injection Cylinder 35 Injection Chamber 36 (nozzle side) wall surface 37 Injection sub path 37a (ejection sub path) opening
Claims (2)
合成樹脂材料を可塑化する可塑化部と、該可塑化部から
連通路で連通された射出室に前記可塑化された溶融樹脂
を蓄積・計量する射出部と、を備え、 該射出部は射出シリンダ内に計量された樹脂材料を射出
プランジャの前進によって金型に射出するプリプラ式射
出成形機であって、 前記射出室のノズル側壁面の周縁部に配置された前記連
通路の開口と、 一端が、前記射出室のノズル側壁面の中央に開口し、か
つ他端が前記ノズルの射出口に連通する射出孔と、 一端が、前記射出室のノズル側壁面における、前記射出
孔の開口を挟んで前記連通路の反対となる領域に開口
し、 かつ他端が前記射出孔に連通する、少なくとも１個の射
出副路とを備えたプリプラ式射出成形機用プランジャに
おいて、 該プランジャ頭部側中央で前記ノズル側に突出し、かつ
前記射出孔に挿入可能とした棒状突起を形成して、 該突起は前記プランジャが前進して射出充填完了前に前
記射出孔に挿入されて開口を閉塞し、 前記射出室における残留し易い残滓を、前記射出副路に
導くこと、 を特徴とする、プリプラ式射出成形機用プランジャ。1. A plasticizing section for rotating a screw in a heating cylinder to plasticize a synthetic resin material, and the plasticized molten resin is accumulated in an injection chamber communicated from the plasticizing section through a communication passage. An injection section for measuring, the injection section being a pre-plastic injection molding machine for injecting a resin material measured in an injection cylinder into a mold by advancing an injection plunger, wherein a nozzle side wall surface of the injection chamber An opening of the communication passage arranged at a peripheral edge portion of the nozzle; an injection hole having one end opening at the center of the nozzle side wall surface of the injection chamber and the other end communicating with the injection port of the nozzle; The nozzle side wall of the injection chamber has at least one injection sub-passage that opens in a region opposite to the communication passage across the opening of the injection hole and has the other end communicating with the injection hole. Plunger for injection molding machine A rod-shaped projection that protrudes toward the nozzle at the center of the plunger head side and that can be inserted into the injection hole, and the projection is inserted into the injection hole before the plunger advances and injection filling is completed. A plug for a pre-plastic injection molding machine, characterized in that the opening is closed to guide the residue, which tends to remain in the injection chamber, to the injection sub-passage.
状突起は、太さが同一直径の円柱もしくはその先端側が
細くなるようにした截頭円錐状の円柱であること、 を特徴とする、請求項１のプリプラ式射出成形機用プラ
ンジャ。2. The rod-shaped projection formed at the center of the plunger head side is a columnar cylinder having the same diameter or a truncated cone with its tip side narrowed. A plunger for a pre-plastic injection molding machine according to Item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17983594A JPH0811175A (en) | 1994-06-27 | 1994-06-27 | Plunger for preplastication type injection molding machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17983594A JPH0811175A (en) | 1994-06-27 | 1994-06-27 | Plunger for preplastication type injection molding machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0811175A true JPH0811175A (en) | 1996-01-16 |
Family
ID=16072735
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17983594A Pending JPH0811175A (en) | 1994-06-27 | 1994-06-27 | Plunger for preplastication type injection molding machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0811175A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009137260A (en) * | 2007-12-10 | 2009-06-25 | Canon Electronics Inc | Injection molding machine, resin material plasticizing and delivering apparatus and its rotor |
| CN113414074A (en) * | 2021-04-02 | 2021-09-21 | 中材科技（邯郸）风电叶片有限公司 | Flushing-free device for epoxy resin mixed glue |
-
1994
- 1994-06-27 JP JP17983594A patent/JPH0811175A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009137260A (en) * | 2007-12-10 | 2009-06-25 | Canon Electronics Inc | Injection molding machine, resin material plasticizing and delivering apparatus and its rotor |
| CN113414074A (en) * | 2021-04-02 | 2021-09-21 | 中材科技（邯郸）风电叶片有限公司 | Flushing-free device for epoxy resin mixed glue |
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