JPH0376647B2 - - Google Patents
Info
- Publication number
- JPH0376647B2 JPH0376647B2 JP59221470A JP22147084A JPH0376647B2 JP H0376647 B2 JPH0376647 B2 JP H0376647B2 JP 59221470 A JP59221470 A JP 59221470A JP 22147084 A JP22147084 A JP 22147084A JP H0376647 B2 JPH0376647 B2 JP H0376647B2
- Authority
- JP
- Japan
- Prior art keywords
- ring
- screw
- backflow prevention
- molten plastic
- kneading
- 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 - Lifetime
Links
- 230000002265 prevention Effects 0.000 claims description 35
- 239000004033 plastic Substances 0.000 claims description 32
- 229920003023 plastic Polymers 0.000 claims description 32
- 238000004898 kneading Methods 0.000 claims description 25
- 238000001746 injection moulding Methods 0.000 claims description 11
- 230000000694 effects Effects 0.000 description 10
- 239000000463 material Substances 0.000 description 7
- 230000002093 peripheral effect Effects 0.000 description 5
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000003063 flame retardant Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
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
- B29C45/58—Details
- B29C45/581—Devices for influencing the material flow, e.g. "torpedo constructions" or mixing devices
-
- 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
- B29C45/47—Means for plasticising or homogenising the moulding material or forcing it into the mould using screws
- B29C45/50—Axially movable screw
- B29C45/52—Non-return devices
-
- 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
- B29C45/47—Means for plasticising or homogenising the moulding material or forcing it into the mould using screws
- B29C45/50—Axially movable screw
- B29C45/52—Non-return devices
- B29C2045/528—Mixing means forming part of or in close proximity to the non-return valve
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は射出成形機の逆流防止装置に係り、該
装置に混練効果を持たせたものに関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a backflow prevention device for an injection molding machine, and to a device that has a kneading effect.
粘度の低いプラスチツク（例えばポリエチレ
ン、ナイロン、ポリスチレン）を射出する射出成
形機のスクリユーヘツドには、第１１図及び第１
２図に示すような逆流防止リング５が被嵌されて
いる。このリング５はピン１０と弁座２との間で
軸方向に移動自在に遊嵌され、スクリユーヘツド
３の外周面とリング５の内周面との間に可塑化流
流通用の隙間が形成されている。従つて、スクリ
ユー１を回転させ溶融プラスチツクをスクリユー
ヘツド３の先端側に送り込む際には、第１１図の
如くリング５と弁座２との間が開放され、可塑化
流の流通路が矢印の如く形成される。このとき同
図では図示しないノズルが閉塞されているため、
可塑化流の流通に伴つてシリンダー１は後方へ
（同図のような縦型射出成形機では上方へ）移動
する。次いで、ノズルを開放すると共に、シリン
ダー１の回転を停止しつつ該シリンダー１を水圧
又は油圧により前進させる。すると、シリンダー
ヘツド３の前方に位置する溶融プラスチツクは図
示しない金型内に射出される。このとき射出の反
作用として逆流防止リング５が後方に移動し、そ
のリング後端に形成されたシート面が弁座２に当
接して溶融プラスチツクがシリンダー側に逆流す
るのを防止するものである。
The screw head of an injection molding machine that injects low viscosity plastics (e.g. polyethylene, nylon, polystyrene) should be
A backflow prevention ring 5 as shown in FIG. 2 is fitted. This ring 5 is loosely fitted between the pin 10 and the valve seat 2 so as to be freely movable in the axial direction, and there is a gap between the outer peripheral surface of the screw head 3 and the inner peripheral surface of the ring 5 for the plasticizing flow. It is formed. Therefore, when the screw 1 is rotated to feed the molten plastic to the tip side of the screw head 3, the space between the ring 5 and the valve seat 2 is opened as shown in FIG. It is formed as follows. At this time, the nozzle not shown in the figure is blocked, so
As the plasticizing flow flows, the cylinder 1 moves backward (upward in a vertical injection molding machine as shown in the figure). Next, the nozzle is opened, and while the rotation of the cylinder 1 is stopped, the cylinder 1 is moved forward by water pressure or oil pressure. Then, the molten plastic located in front of the cylinder head 3 is injected into a mold (not shown). At this time, the backflow prevention ring 5 moves rearward as a reaction to the injection, and the seat surface formed at the rear end of the ring comes into contact with the valve seat 2 to prevent the molten plastic from flowing back into the cylinder.
このように、この逆流防止リング５は特に低粘
度のプラスチツク材料の射出成形に当たつては必
要なものであるが、このリングの存在により、そ
の軸方向長さ分だけ溶融プラスチツク材料が成形
機内に長時間滞留することになる。そのため、溶
融したプラスチツク材料がより多く熱分解し、ガ
スが発生して成形機に焼けや黒条を発生させる場
合があつた。特に、プラスチツク材料に難燃助剤
がブレンドされたものについては、その難燃助剤
の熱分解によりさらに多くのガスが発生してい
た。 As described above, this backflow prevention ring 5 is especially necessary for injection molding of low-viscosity plastic materials, but the presence of this ring prevents the molten plastic material from flowing into the molding machine by its axial length. It will stay there for a long time. As a result, more of the molten plastic material was thermally decomposed and gas was generated, which sometimes caused burns and black streaks in the molding machine. In particular, in the case of plastic materials blended with flame retardant additives, even more gas was generated due to thermal decomposition of the flame retardant additives.
なお、実開昭56−135827号公報記載の射出成形
機の逆流防止リングを設けた可塑化スクリユーに
は、その逆流防止リングに螺旋状の突条及びその
突条の切欠きを設けた提案がある。この突条によ
り、溶融樹脂を撹拌すると共にその流れを分断し
ようとするものである。 In addition, in the plasticizing screw equipped with a backflow prevention ring for an injection molding machine described in Japanese Utility Model Application Publication No. 56-135827, there is a proposal in which the backflow prevention ring is provided with a spiral protrusion and a notch in the protrusion. be. The purpose of this protrusion is to stir the molten resin and to interrupt its flow.
しかしながらこの逆流防止リングは、スクリユ
ーに回転自在に嵌装されているため、螺旋状突条
に樹脂が衝突すると、その抵抗によりリング自体
が回転し、撹拌効果を損なう欠点がある。 However, since this backflow prevention ring is rotatably fitted to the screw, when the resin collides with the spiral protrusion, the ring itself rotates due to the resistance, which impairs the stirring effect.
又、実開昭59−171917号公報記載の射出成形機
のスクリユーは、逆流防止リングの内周面と、ス
クリユーネツクの外周面とに夫々同一ピツチの波
状周面を形成したものである。そして、射出時に
は逆流防止リングとスクリユーネツクとの間を波
状に溶融樹脂を流通させるもであるが、その流通
による撹拌効果はそれ程大きなものではない。
又、このスクリユーの逆流防止リングも周方向に
自由に回転できるものである。その点からも撹拌
効果が少ない点がある。 Further, the screw of the injection molding machine described in Japanese Utility Model Application Publication No. 59-171917 has wavy peripheral surfaces of the same pitch formed on the inner peripheral surface of the backflow prevention ring and the outer peripheral surface of the screw neck, respectively. During injection, the molten resin is caused to flow in a wavy manner between the backflow prevention ring and the screw neck, but the stirring effect of this flow is not so great.
Further, the backflow prevention ring of this screw can also freely rotate in the circumferential direction. From this point of view as well, the stirring effect is low.
そこで、本発明は逆流防止リング自体に混練効
果を持たせることにより、その分だけスクリユー
の混練部長さを短くし、全体として溶融プラスチ
ツクの滞留時間を減少させることにより、成形機
内部でのガスの発生を可能な限り防止することを
主たる目的とし、その他の目的として逆流防止リ
ングの効果を補助すると共に、リング内での溶融
プラスチツクの流れを方向ずけることによりその
滞留を防止するものであり、その要旨とするとこ
ろは次の通りである。
Therefore, the present invention provides a kneading effect to the backflow prevention ring itself, thereby shortening the length of the kneading section of the screw and reducing the residence time of the molten plastic as a whole, thereby reducing the amount of gas inside the molding machine. The main purpose is to prevent the occurrence of molten plastic as much as possible, and the other purpose is to assist the effectiveness of the backflow prevention ring and to prevent molten plastic from stagnation by directing the flow of molten plastic within the ring. The main points are as follows.
即ち、射出成形機のスクリユー１の先端に弁座
２及びスクリユーヘツド３が設けられる。そし
て、逆流防止リング５が軸方向に移動自在になる
ように、スクリユーヘツド３の外周に遊嵌され
る。そして、その移動により該リング５の後端に
形成されたシート面４が前記弁座２に接離自在に
構成される。ここにおいて、本発明の特徴とする
ところは、前記リング５又はスクリユーヘツド３
に溶融プラスチツク混練用の螺旋状混練通路６が
形成されると共に、前記リング５の先端部に形成
されたスリツト１５に、前記ヘツド３外周に突設
した回り止め用のピン１０が遊嵌されたことを特
徴とする。 That is, a valve seat 2 and a screw head 3 are provided at the tip of a screw 1 of an injection molding machine. The backflow prevention ring 5 is loosely fitted around the outer periphery of the screw head 3 so as to be freely movable in the axial direction. As a result of this movement, the seat surface 4 formed at the rear end of the ring 5 can move toward and away from the valve seat 2. Here, the feature of the present invention is that the ring 5 or the screw head 3
A spiral kneading passage 6 for kneading molten plastic is formed in the ring 5, and a rotation prevention pin 10 protruding from the outer periphery of the head 3 is loosely fitted into a slit 15 formed at the tip of the ring 5. It is characterized by
次に図面に基づいて本発明の各実施例につき説
明する。
Next, each embodiment of the present invention will be described based on the drawings.
第１図は本発明の第１実施例の要部縦断面図で
あり、第２図はその逆流防止リング５の縦断面斜
視図である。この実施例では第２図の如く逆流防
止リング５の内面に螺旋条の凸条１１が形成され
ている。そのため、溶融プラスチツクはこの凸条
１１に沿つて螺線条に逆流防止リング内を螺回
し、その間に混練されつつスクリユーヘツド３の
前方に移動するものである。なお、このリング５
の後端面にはシート面４が形成され、これがスク
リユーの弁座２に整合する。又、第１図では弁座
２はシリンダ１の先端に設けられているが、この
弁座をスクリユーヘツド３自体に設けてもよい。
次に、逆流防止リング５の先端にはすわり状のス
リツト１５が互いに180度位置を異にして２ヶ所
形成されている。そして、スクリユーヘツド３に
貫通固定されたピン１０が、このスリツト１５に
第１図の如く係止されている。そのため、このリ
ング５は第１図においてスクリユーヘツド３に対
し上下方向に移動自在であるとともに、該スクリ
ユーヘツド３に対し軸の回りには相対的な回転が
拘束されている。 FIG. 1 is a vertical cross-sectional view of a main part of a first embodiment of the present invention, and FIG. 2 is a vertical cross-sectional perspective view of a backflow prevention ring 5 thereof. In this embodiment, a spiral protrusion 11 is formed on the inner surface of the backflow prevention ring 5 as shown in FIG. Therefore, the molten plastic is spirally wound inside the backflow prevention ring along this protruding line 11, and moved to the front of the screw head 3 while being kneaded during this time. In addition, this ring 5
A seat surface 4 is formed on the rear end surface of the screw and is aligned with the valve seat 2 of the screw. Further, although the valve seat 2 is provided at the tip of the cylinder 1 in FIG. 1, this valve seat may be provided on the screw head 3 itself.
Next, two seat-shaped slits 15 are formed at the tip of the backflow prevention ring 5 at positions 180 degrees apart from each other. A pin 10, which is fixed through the screw head 3, is locked in this slit 15 as shown in FIG. Therefore, this ring 5 is movable vertically with respect to the screw head 3 in FIG. 1, and is restrained from rotating relative to the screw head 3 around the axis.
而して、スクリユー１の回転に伴つて溶融プラ
スチツクは下方に押し出され、逆流防止リング５
と弁座２との間に浸入して該リング５の凸条１１
に案内され、螺線条に導かれる。そして、このリ
ング５内で混練されてスクリユーヘツド３前方に
押し出される。従つて、リング５の各凸条の間が
溶融プラスチツクの混練通路６を形成するもので
ある。なお、第１０図はシリンダー１の全体を示
す図であり、上方から供給部L1と圧縮部L2と混
練部L3とが形成されている。そして、この混練
部L3は、従来型射出成形機による本来の混練部
分であるL4と本発明により加えられた逆流防止
リング５内の混練部L5との和により構成されて
いる。故に、本装置では混練効果を同一とすれば
従来の装置に比べてスクリユー自体の混練部の長
さをリングの混練長さ分だけ短くし得る。そのた
め、全体として溶融プラスチツクの滞留時間を短
縮できる。 As the screw 1 rotates, the molten plastic is pushed downward and the backflow prevention ring 5
and the valve seat 2, and the protrusion 11 of the ring 5
guided by and guided by the spiral. Then, it is kneaded within this ring 5 and pushed out in front of the screw head 3. Therefore, a kneading passage 6 for the molten plastic is formed between the respective protrusions of the ring 5. Note that FIG. 10 is a diagram showing the entire cylinder 1, in which a supply section L1 , a compression section L2 , and a kneading section L3 are formed from above. The kneading section L3 is constituted by the sum of the original kneading section L4 of the conventional injection molding machine and the kneading section L5 inside the backflow prevention ring 5 added according to the present invention. Therefore, in this apparatus, the length of the kneading section of the screw itself can be made shorter by the kneading length of the ring compared to the conventional apparatus, provided that the kneading effect is the same. Therefore, the overall residence time of the molten plastic can be shortened.
次に、第３図は本発明の第２実施例であつて、
第２図の実施例と異なる点は凸条１１が複数本形
成されると共に、その凸条１１とリング５の軸線
とのなす傾斜角度がより小さく形成されたもので
ある。 Next, FIG. 3 shows a second embodiment of the present invention, in which
The difference from the embodiment shown in FIG. 2 is that a plurality of protrusions 11 are formed, and the angle of inclination between the protrusions 11 and the axis of the ring 5 is smaller.
又、第４図は本発明の第３実施例であり、凸条
１１の螺回方向が第２図の実施例のものと逆に形
成されている。この第４図の逆流防止リング５を
第１図におけるスクリユー１に取付ければ、第２
図の場合とは逆向きにプラスチツクが混練され
る。 Further, FIG. 4 shows a third embodiment of the present invention, in which the spiral direction of the protrusion 11 is opposite to that of the embodiment shown in FIG. If the backflow prevention ring 5 shown in FIG. 4 is attached to the screw 1 shown in FIG.
The plastic is kneaded in the opposite direction to that shown.
次に第５図は第３図における凸条を逆向きに形
成したものである。次いで、第６図は凸条の代わ
りに螺線条の溝１２を複数本網目状に形成したも
のである。なお、同図において全ての溝１２を同
一方向に形成してもあるいは、一本の溝１２のみ
を螺線条に形成しても良い。 Next, FIG. 5 shows a configuration in which the protrusions in FIG. 3 are formed in the opposite direction. Next, FIG. 6 shows a structure in which a plurality of spiral grooves 12 are formed in a mesh shape instead of the protrusions. In addition, in the figure, all the grooves 12 may be formed in the same direction, or only one groove 12 may be formed in a spiral line.
次いで、第７図は本発明の第６実施例であり、
逆流防止リング５の内面側にリング状の凸条１１
を形成すると共に、リングの外側面にはリング溝
１７を削切する。そして、凸条１１の両側に夫々
複数の孔１６を穿設し、それが夫々リング溝１７
に連通するようにしたものである。従つて、溶融
プラスチツクの混練通路はこの孔１６及びリング
溝１７自体で形成されることになる。 Next, FIG. 7 shows a sixth embodiment of the present invention,
A ring-shaped protrusion 11 is provided on the inner surface of the backflow prevention ring 5.
At the same time, a ring groove 17 is cut on the outer surface of the ring. Then, a plurality of holes 16 are formed on both sides of the protrusion 11, and each of the holes 16 forms a ring groove 17.
It was designed to communicate with the Therefore, the kneading passage for the molten plastic is formed by this hole 16 and the ring groove 17 itself.
次いで、第８図は本発明の第７実施例であり、
この実施例ではスクリユーヘツド３自体に螺線条
の凸条１１を設けたものである。そして、逆流防
止リング５自体は従来のリングと代わるところが
ない。なお、凸条１１の代わりに螺線条凹溝をス
クリユーヘツド３に設けてもよい。又、第９図は
第８図の実施例と凸条１１の向きが異なるもので
ある。 Next, FIG. 8 shows a seventh embodiment of the present invention,
In this embodiment, a spiral protrusion 11 is provided on the screw head 3 itself. The backflow prevention ring 5 itself cannot be replaced with a conventional ring. Incidentally, instead of the protruding strip 11, a spiral groove may be provided on the screw head 3. Furthermore, the embodiment shown in FIG. 9 is different from the embodiment shown in FIG. 8 in the direction of the protrusions 11.
次に本発明の作用につき説明する。 Next, the operation of the present invention will be explained.
先ず、第１０図においてホツパー１８から供給
された粒状のプラスチツク材料はスクリユー１の
回転に伴つて下方に搬送される。そして、圧縮部
L2においてプラスチツク材料は圧縮されると共
に、溶融して本来の混練部であるL4に達する。
次いで、溶融プラスチツクは第１図において弁座
２とシート面４の間からリング５内に浸入し、リ
ング５の混練通路６を通りさらに混練されてスク
リユーヘツド３の前方に押し出される。このとき
ノズル８が閉塞されているため、溶融プラスチツ
クの流動に伴つてスクリユー１はそのスクリユー
ヘツド３と共に上方に移動する。そして、スクリ
ユー１が一定長さ上方に移動すると、その回転を
停止し、図示しない油圧装置又は水圧装置により
スクリユー１が下方へ押し出される。このときノ
ズル８が開放され溶融プラスチツクは金型内に射
出される。すると、この射出の反力により逆流防
止リング５が上方に移動し、シート面４と弁座２
とが密着して可塑化流の逆流を防止する。なお、
混練通路６自体が可塑化流の流体抵抗を増大する
ことになるから、逆流防止リング５はより強く弁
座２に押しつけられ可塑化流の逆流を更に効果的
に防止することになる。又、スクリユー１の回転
中においては可塑化流は常に混練通路６に沿つて
強制的に移動されるため、リング内で可塑化流の
一部に滞留が起こることを防止し得る。 First, in FIG. 10, the granular plastic material supplied from the hopper 18 is conveyed downward as the screw 1 rotates. And the compression section
At L2 , the plastic material is compressed and melted to reach the actual kneading section L4 .
The molten plastic then enters the ring 5 between the valve seat 2 and the seat surface 4 in FIG. At this time, since the nozzle 8 is closed, the screw 1 and its screw head 3 move upward as the molten plastic flows. When the screw 1 moves upward by a certain length, its rotation is stopped and the screw 1 is pushed downward by a hydraulic device or water pressure device (not shown). At this time, the nozzle 8 is opened and the molten plastic is injected into the mold. Then, the backflow prevention ring 5 moves upward due to the reaction force of this injection, and the seat surface 4 and the valve seat 2
are in close contact with each other to prevent backflow of plasticizing flow. In addition,
Since the kneading passage 6 itself increases the fluid resistance of the plasticizing flow, the backflow prevention ring 5 is pressed more strongly against the valve seat 2, and the backflow of the plasticizing flow is more effectively prevented. Furthermore, since the plasticizing flow is always forcibly moved along the kneading path 6 while the screw 1 is rotating, it is possible to prevent a portion of the plasticizing flow from stagnation within the ring.
本装置は、特にそのスクリユーヘツド部に螺旋
状混練通路が形成されると共に、逆流防止リング
５が周方向に回転しないように且つ、軸方向には
移動自在に設けられているから、それにより溶融
プラスチツクを螺旋状に効果的に混練することが
でき、その分だけスクリユー１の混練部L3を短
くし得る効果がある。それにより、全体として溶
融プラスチツクが成形機内部で滞留する時間を可
能な限り短くし、熱分解によるガス成分の発生を
可能な限り防止し、プラスチツク成形品に焼けや
黒条の発生するのを防止し得る。
In this device, a spiral kneading passage is particularly formed in the screw head portion, and the backflow prevention ring 5 is provided so as not to rotate in the circumferential direction but to be movable in the axial direction. The molten plastic can be effectively kneaded in a spiral shape, and the kneading section L3 of the screw 1 can be shortened accordingly. As a result, the time that the molten plastic stays inside the molding machine is minimized, the generation of gas components due to thermal decomposition is prevented as much as possible, and the occurrence of burns and black streaks on plastic molded products is prevented. It is possible.
(2) 又、この混練通路はそれ自体が溶融プラスチ
ツクの流動抵抗を増大させるため、金型への射
出に当たつては、逆流防止リングのシール効果
を補助し得る。即ち、スクリユーヘツド部にお
ける逆流をより確実に防止し得る効果がある。(2) Also, since this kneading passage itself increases the flow resistance of the molten plastic, it can assist the sealing effect of the backflow prevention ring during injection into the mold. That is, there is an effect that backflow in the screw head portion can be more reliably prevented.
(3) 又、本装置によれば溶融プラスチツクは逆流
防止リング５等の混練通路において流れの方向
を一定づけられるため、従来型リング内で起こ
りがちであつた溶融プラスチツクの一部に生ず
る滞留を防止する効果がある。それにより、成
形品の黒条や焼けの発生をさらに効果的に防止
し得る。(3) In addition, according to this device, the flow direction of the molten plastic can be fixed in the kneading passage such as the backflow prevention ring 5, so the stagnation that occurs in a part of the molten plastic that tends to occur in the conventional ring can be avoided. It has the effect of preventing Thereby, the occurrence of black streaks and burns on the molded product can be more effectively prevented.
第１図は本発明の第１実施例の要部縦断面図、
第２図は同実施例の逆流防止リングの縦断面斜視
図、第３図〜第７図は本発明の第２〜第６実施例
の逆流防止リングにおける縦断面斜視図、第８図
及び第９図は本発明の第７実施例及び第８実施例
の要部縦断面図である、第１０図は本発明の逆流
防止装置を有する縦型射出成形機の縦断面略図、
第１１図及び第１２図は従来型射出成形機の要部
縦断面図であつて、夫々溶融プラスチツク材料の
流れを説明する説明図。
１……スクリユー、２……弁座、３……スクリ
ユーヘツド、４……シート面、５……逆流防止リ
ング、６……混練通路、７……スクリユーシリン
ダ、８……ノズル、９……開口、１０……ピン、
１１……凸条、１２……溝、１３……ネジ部、１
４……螺線条、１５……スリツト、１６……孔、
１７……リング溝、１８……ホツパー、L1……
供給部、L2……圧縮部、L3……混練部。
FIG. 1 is a vertical sectional view of the main part of the first embodiment of the present invention,
FIG. 2 is a vertical cross-sectional perspective view of a backflow prevention ring according to the same embodiment, FIGS. 3 to 7 are vertical cross-sectional perspective views of backflow prevention rings according to second to sixth embodiments of the present invention, and FIGS. 9 is a vertical cross-sectional view of main parts of the seventh and eighth embodiments of the present invention, FIG. 10 is a schematic vertical cross-sectional view of a vertical injection molding machine having a backflow prevention device of the present invention,
FIGS. 11 and 12 are longitudinal sectional views of main parts of a conventional injection molding machine, and are explanatory diagrams for explaining the flow of molten plastic material, respectively. 1... Screw, 2... Valve seat, 3... Screw head, 4... Seat surface, 5... Backflow prevention ring, 6... Kneading passage, 7... Screw cylinder, 8... Nozzle, 9 ...Opening, 10...Pin,
11...Convex strip, 12...Groove, 13...Threaded portion, 1
4... spiral stripe, 15... slit, 16... hole,
17...Ring groove, 18...Hopper, L 1 ...
Supply section, L 2 ... compression section, L 3 ... kneading section.
Claims (1)
座２及びスクリユーヘツド３と、軸方向へ移動自
在に該ヘツド３の外周に遊嵌されることにより、
後端に形成されたシート面４が前記弁座２に接離
自在に構成された逆流防止リング５と、を具備す
る逆流防止装置において、前記リング５またはス
クリユーヘツド３に溶融プラスチツク混練用の螺
旋状混練通路６が形成されると共に、前記リング
５の先端部に形成されたスリツト１５に、前記ヘ
ツド３外周に突設した回り止め用のピン１０が遊
嵌されたことを特徴とするスクリユーヘツド部に
おける逆流防止装置。1. The valve seat 2 and the screw head 3 provided at the tip of the screw 1 of the injection molding machine are loosely fitted to the outer periphery of the screw head 3 so as to be movable in the axial direction.
A backflow prevention device comprising a backflow prevention ring 5 having a seat surface 4 formed at the rear end that can freely move toward and away from the valve seat 2, wherein the ring 5 or the screw head 3 is provided with a screw for kneading molten plastic. The screw is characterized in that a spiral kneading passage 6 is formed, and a locking pin 10 protruding from the outer periphery of the head 3 is loosely fitted into a slit 15 formed at the tip of the ring 5. Backflow prevention device in the head section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22147084A JPS61100427A (en) | 1984-10-22 | 1984-10-22 | Apparatus for preventing back-flow at screw head section |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22147084A JPS61100427A (en) | 1984-10-22 | 1984-10-22 | Apparatus for preventing back-flow at screw head section |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61100427A JPS61100427A (en) | 1986-05-19 |
| JPH0376647B2 true JPH0376647B2 (en) | 1991-12-06 |
Family
ID=16767216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22147084A Granted JPS61100427A (en) | 1984-10-22 | 1984-10-22 | Apparatus for preventing back-flow at screw head section |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61100427A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2718800B1 (en) * | 1994-04-13 | 1996-07-12 | Alain Georges Rene Viron | Self-centering floating pin valve with two support points on flats machined or forged at a given angle. |
| DE10217758B4 (en) | 2002-04-20 | 2005-06-16 | Krauss-Maffei Kunststofftechnik Gmbh | Backflow lock for injection molding machine |
| US6709147B1 (en) * | 2002-12-05 | 2004-03-23 | Rauwendaal Extrusion Engineering, Inc. | Intermeshing element mixer |
| JP5589328B2 (en) * | 2009-09-18 | 2014-09-17 | 宇部興産機械株式会社 | Screw for injection molding equipment |
| JP2017056655A (en) * | 2015-09-17 | 2017-03-23 | 東洋機械金属株式会社 | Injection molding machine |
| JP7083678B2 (en) * | 2018-03-29 | 2022-06-13 | 住友重機械工業株式会社 | Injection equipment and injection molding machine |
| JP7209882B2 (en) * | 2018-04-19 | 2023-01-20 | 東洋機械金属株式会社 | screw head |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6027612Y2 (en) * | 1980-03-15 | 1985-08-21 | 株式会社日本製鋼所 | Plasticizing screw with backflow prevention ring for injection molding machine |
| JPS59171917U (en) * | 1983-05-02 | 1984-11-16 | 積水化学工業株式会社 | Injection molding machine screw |
-
1984
- 1984-10-22 JP JP22147084A patent/JPS61100427A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61100427A (en) | 1986-05-19 |
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