JPH0740374A - Hollow injection molding machine - Google Patents

Hollow injection molding machine

Info

Publication number
JPH0740374A
JPH0740374A JP18983893A JP18983893A JPH0740374A JP H0740374 A JPH0740374 A JP H0740374A JP 18983893 A JP18983893 A JP 18983893A JP 18983893 A JP18983893 A JP 18983893A JP H0740374 A JPH0740374 A JP H0740374A
Authority
JP
Japan
Prior art keywords
gate
gas
resin material
flow
cavity
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.)
Granted
Application number
JP18983893A
Other languages
Japanese (ja)
Other versions
JP3036309B2 (en
Inventor
Kyosuke Yasumi
恭介 八角
Hidenori Miyazono
英徳 宮園
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nissan Motor Co Ltd
Original Assignee
Nissan Motor Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nissan Motor Co Ltd filed Critical Nissan Motor Co Ltd
Priority to JP18983893A priority Critical patent/JP3036309B2/en
Publication of JPH0740374A publication Critical patent/JPH0740374A/en
Application granted granted Critical
Publication of JP3036309B2 publication Critical patent/JP3036309B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • B29C45/1703—Introducing an auxiliary fluid into the mould
    • B29C45/1704—Introducing an auxiliary fluid into the mould the fluid being introduced into the interior of the injected material which is still in a molten state, e.g. for producing hollow articles

Abstract

PURPOSE:To prevent the back flow of gas from a gate after the completion of injection by locally reducing the depth of the part opposed to an inert gas flow direction of the outlet opening part of the gate to form a constricted part. CONSTITUTION:The central part 12b meeting with the gas passage on the side of a gas channel 7 while directly opposed to the gas passage of the opening part 12 of a fan gate 11 having a flat and wide outlet opening part 12 is locally set small so that the depth H2 thereof becomes 1/2 or less the depth H1 of other part 12a. Since flow resistance in this constricted part 12b increases slightly but the increase degree of the flow resistance is slight as compared with the general part 12a, the original function of the gate is held. A resin material is rapidly cooled and solidified in the constricted part 12b immediately after the injection of the resin material into a cavity 3 is completed and gas sealing effect is developed. Therefore, injected inert gas passes through the gate 11 to be prevented from flowing backward to the upstream side and is allowed to flow along a thick-walled part 8 to apply inner pressure to the cavity. As a result, the flow of the resin material is promoted and the generation of a sink is prevented.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、樹脂の射出成形時にキ
ャビティ内の樹脂材料のなかにガスを導入することによ
って、樹脂成形品の一部に中空部を形成するようにした
中空射出成形装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow injection molding apparatus for forming a hollow portion in a part of a resin molded product by introducing a gas into a resin material in a cavity during resin injection molding. Regarding

【０００２】[0002]

【従来の技術】自動車用バンパーのバンパーフェイシア
（以下、成形品という）の成形を目的とした中空射出形
成装置としては、例えば実開昭６３−４３７１１号公報
等に紹介されたものがある。2. Description of the Related Art As a hollow injection molding apparatus for molding a bumper fascia (hereinafter referred to as a molded product) of a bumper for an automobile, there is, for example, one introduced in Japanese Utility Model Publication No. 63-43711.

【０００３】ところで、射出成形装置にあっては、ガス
インジェクションタイプのものも知られており、本出願
人はその試みとして図３，４，５に示すように、固定型
（キャビティブロック）１と可動型（コアブロック）２
とで形成されたキャビティ３に対して、図示外のスプル
ー部から導入された樹脂材料をランナ４とファンゲート
５を通して充填する一方、所定のタイミング例えば樹脂
材料の射出完了直後に予めキャビティ３に臨ませたガス
ノズル６からキャビティ３内の樹脂材料のなかに窒素ガ
スに代表されるような不活性ガスを導入するようにした
ものでバンパーフェイシアＷを成形しようとするもので
ある。By the way, as the injection molding apparatus, a gas injection type is also known, and the applicant of the present invention has tried to make a fixed mold (cavity block) 1 as shown in FIGS. Movable type (core block) 2
While the resin material introduced from the sprue portion (not shown) is filled into the cavity 3 formed by and through the runner 4 and the fan gate 5, the resin is introduced into the cavity 3 in advance at a predetermined timing, for example, immediately after the injection of the resin material is completed. The bumper fascia W is intended to be formed by introducing an inert gas typified by nitrogen gas into the resin material in the cavity 3 from the gas nozzle 6 which is not present.

【０００４】そして、前記キャビティ３内に導入された
不活性ガスは、ガスチャンネル７から成形品Ｗとなるべ
き部分のうち通流抵抗の少ない部分、すなわち相対的に
冷却固化が遅れ気味の厚肉部８の中心部を通流して拡が
ることになる。なお、上記のガスチャンネル７は、ガス
ノズル６と、成形品の一部となる厚肉部８とを、連続し
たガス通路として相互に接続する機能を有する。The inert gas introduced into the cavity 3 is a portion having a small flow resistance in the portion to be the molded product W from the gas channel 7, that is, a thick wall with a relatively delayed cooling and solidification. It will flow through the central part of the part 8 and spread. The gas channel 7 has a function of interconnecting the gas nozzle 6 and the thick portion 8 which is a part of the molded product as a continuous gas passage.

【０００５】その結果、通流中のガスは樹脂材料に内圧
をかけることによりその樹脂材料の流動を助けると同時
に、ひけ等の発生を防止し、さらには成形品Ｗの厚肉部
８にはガスの通路がそのまま中空部９として残ることに
より補強リブとして機能することになる。As a result, the flowing gas applies an internal pressure to the resin material to assist the flow of the resin material and at the same time prevent the occurrence of sink marks and the thick wall portion 8 of the molded product W. Since the gas passage remains as the hollow portion 9 as it is, it functions as a reinforcing rib.

【０００６】ところで、上記のバンパーフェイシアＷの
成形においては、バンパーフェイシアＷ自体が大型の成
形品である点を考慮し、キャビティ３の各部の樹脂材料
の充填が均一となるように偏平幅広の出口側開口部５ａ
をもつファンゲート５を採用しているものであるが、そ
の出口側開口部５ａの面積が小さいと、樹脂材料の流動
の抵抗となって充填不足（ショートショット）等の成形
不良の原因となり、逆に出口側開口部５ａの面積が大き
すぎると、射出完了直後に樹脂材料をゲート部分で速や
かに冷却固化させて逆流しないようにしてその通路を封
鎖するいわゆるゲートシール機能に支障をきたすことに
なる。このようなことから、従来は上記の諸点を考慮し
てファンゲート５の出口側開口部５ａの面積を経験的に
選定している。なお、図５の符号１０は、出口側開口部
５ａから吐出される樹脂材料の当初の流動形態を示して
いる。In the molding of the bumper fascia W, in consideration of the fact that the bumper fascia W itself is a large molded product, a flat wide outlet is provided so that the resin material in each portion of the cavity 3 is uniformly filled. Side opening 5a
However, if the area of the outlet side opening 5a is small, it causes flow resistance of the resin material and causes molding defects such as insufficient filling (short shot). On the contrary, if the area of the outlet side opening 5a is too large, the so-called gate seal function of blocking the passage by blocking the backward flow of the resin material by immediately cooling and solidifying the resin material immediately after the completion of injection is impaired. Become. For this reason, conventionally, the area of the outlet side opening 5a of the fan gate 5 is empirically selected in consideration of the above points. The reference numeral 10 in FIG. 5 indicates the initial flow form of the resin material discharged from the outlet side opening 5a.

【０００７】[0007]

【発明が解決しようとする課題】しかしながら、上記の
ような従来の構造においては、ファンゲート５の出口側
開口部５ａの面積の選定にあたって不活性ガスの流動が
考慮されていないため、特に図３，４，５に示すように
ファンゲート５とガスノズル６が比較的近い位置に設置
されていて、しかも、その出口側開口部５ａに向かって
不活性ガスが通流する場合には、図６に示すように不活
性ガスがファンゲート５を通過してランナ４および射出
ノズル側に逆流してしまい、次のショットの際に支障を
きたす結果となって好ましくない。However, in the conventional structure as described above, the flow of the inert gas is not taken into consideration in the selection of the area of the outlet side opening 5a of the fan gate 5, so that the structure shown in FIG. 6, 4 and 5, the fan gate 5 and the gas nozzle 6 are installed relatively close to each other, and when the inert gas flows toward the outlet side opening 5a thereof, as shown in FIG. As shown in the drawing, the inert gas passes through the fan gate 5 and flows back to the runner 4 and the injection nozzle side, which causes a trouble in the next shot, which is not preferable.

【０００８】本発明は以上のような課題に着目してなさ
れたもので、その目的とするところは、ファンゲートか
らその上流側へのガスの逆流を防止した構造を提供する
ことにある。The present invention has been made in view of the above problems, and an object of the present invention is to provide a structure which prevents the reverse flow of gas from a fan gate to its upstream side.

【０００９】[0009]

【課題を解決するための手段】本発明は、偏平幅広の出
口側開口部をもつゲートを通して射出成形金型のキャビ
ティに樹脂材料を充填する一方、前記キャビティに臨ま
せたガスノズルからキャビティ内の樹脂材料にガスを導
入して成形品の一部に中空部を形成するようにした中空
射出成形装置において、前記ゲートの出口側開口部のう
ちガスの流れ方向と直接対向する部分の深さを局部的に
狭めて狭窄部を形成したことを特徴としている。According to the present invention, a cavity of an injection molding die is filled with a resin material through a gate having a flat and wide outlet side opening, and a resin in the cavity is injected from a gas nozzle facing the cavity. In a hollow injection molding device in which a gas is introduced into a material to form a hollow portion in a part of a molded article, the depth of a portion of the opening on the outlet side of the gate that directly faces the gas flow direction is locally determined. It is characterized in that a narrowed portion is formed by narrowing it.

【００１０】[0010]

【作用】この構造によると、ゲートの出口側開口部のう
ちガスの流れと直接対向する部分の深さを局部的に狭め
て狭窄部としていることから、射出完了時点ではその狭
めた部分から固化が始まってゲートシール機能が発揮さ
れる。したがって、例えば射出完了直後にガスの導入を
行っても、ゲートからその上流側へのガスの逆流が阻止
される。According to this structure, the depth of the portion of the opening on the outlet side of the gate that directly faces the gas flow is locally narrowed to form a narrowed portion, so at the completion of injection, the narrowed portion is solidified. Starts and the gate seal function is demonstrated. Therefore, for example, even if the gas is introduced immediately after the completion of the injection, the reverse flow of the gas from the gate to the upstream side is prevented.

【００１１】[0011]

【実施例】図１，２は本発明の一実施例を示す図で、図
３，４，５に示した従来構造と共通する部分には同一符
号を付してある。1 and 2 are views showing an embodiment of the present invention, in which parts common to those of the conventional structure shown in FIGS.

【００１２】図１，２に示すように、ファンゲート１１
はゲート幅Ｇ1およびゲートランドＧ2の偏平幅広の出口
側開口部１２を有しているものであるが、この出口側開
口部１２のうちガスの流れすなわちガスチャンネル７側
のガス通路と直接正対しつつ合流する中央部分につい
て、その深さＨ2を一般部１２ａの深さＨ1に比べておよ
そ二分の一以下となるように局部的に小さく設定して狭
窄部１２ｂを形成してある。As shown in FIGS. 1 and 2, the fan gate 11
Has an outlet-side opening 12 having a flat width of the gate width G 1 and the gate land G 2 , and the gas flow in the outlet-side opening 12 is directly connected to the gas passage on the gas channel 7 side. The constricted portion 12b is formed by locally setting the depth H 2 of the central portion, which is directly facing and joining, to be less than or equal to one half of the depth H 1 of the general portion 12a. .

【００１３】そして、上記の狭窄部１２ｂを形成したこ
とによってファンゲート１１本来の機能に支障をきたす
ことがないように、この狭窄部１２ｂと一般部１２ａと
からなる出口側開口部１２全体の開口面積が設定されて
いる。Then, in order to prevent the original function of the fan gate 11 from being hindered by the formation of the narrowed portion 12b, the entire opening of the outlet side opening 12 composed of the narrowed portion 12b and the general portion 12a. The area is set.

【００１４】このような構造によると、樹脂材料の射出
時にはファンゲート１１は従来と同様にゲート本来の機
能を発揮する。そして、前記ファンゲート１１の出口側
開口部１２のうちの狭窄部１２ｂでは、それ以外の一般
部１２ａに比べて深さＨ2が小さいために樹脂材料の流
動抵抗が多少増大することになるものの、その狭窄部１
２ｂの範囲が一般部１２ａに比べてごくわずかであるた
めに、キャビティ３全体に樹脂材料を均一に充填すると
するファンゲート１１本来の機能に支障をきたすような
ことはない。According to such a structure, the fan gate 11 exhibits the original function of the gate when the resin material is injected, as in the conventional case. In the narrowed portion 12b of the outlet side opening 12 of the fan gate 11, the depth H 2 is smaller than that of the other general portion 12a, so that the flow resistance of the resin material is somewhat increased. , The narrowed part 1
Since the range of 2b is much smaller than that of the general portion 12a, the original function of the fan gate 11 for uniformly filling the entire cavity 3 with the resin material is not hindered.

【００１５】一方、前記キャビティ３に対する樹脂材料
の射出完了直後にガスノズル６（図３）から窒素ガス等
の不活性ガスを導入するものとすると、射出完了時点で
はファンゲート１１では従来と同様にゲートシール機能
を発揮する。すなわち、樹脂材料の射出完了と同時に、
ファンゲート１１における樹脂材料を速やかに冷却固化
させて逆流を防止し、その通路を封鎖する。その際、前
記ファンゲート１１の出口側開口部１２のなかでも、深
さＨ1のい一般部１２ａよりも深さＨ1の狭窄部１２ｂの
方が先に冷却固化が進行する。On the other hand, assuming that an inert gas such as nitrogen gas is introduced from the gas nozzle 6 (FIG. 3) immediately after the injection of the resin material into the cavity 3 is completed, the fan gate 11 will be operated at the same time as the conventional gate when the injection is completed. Demonstrate the sealing function. That is, at the same time when the injection of the resin material is completed,
The resin material in the fan gate 11 is quickly cooled and solidified to prevent backflow, and the passage is closed. At that time, the Among outlet opening 12 of the fan gate 11, towards the depth H 1 Noi general portion of the depth H 1 than 12a constriction 12b progresses is cooled and solidified earlier.

【００１６】したがって、上記のようにガスノズル６か
らキャビティ３内の樹脂材料に対して不活性ガスが導入
された場合、その不活性ガスはガスチャンネル７から厚
肉部８側へと流れるべく、ガスチャンネル７を通過した
不活性ガスがファンゲート１１の出口側開口部１２に向
かって流れることになる。その一方、その出口側開口部
１２のうち不活性ガスの流れと正対する狭窄部１２ｂで
は既に樹脂材料の冷却固化が進行していて通路を封鎖し
ているので、不活性ガスがファンゲート１１を通過して
その上流側に逆流することはなく、不活性ガスは上記の
厚肉部８の長手方向に沿って流れることになる。Therefore, when the inert gas is introduced from the gas nozzle 6 into the resin material in the cavity 3 as described above, the inert gas flows so as to flow from the gas channel 7 to the thick portion 8 side. The inert gas that has passed through the channels 7 flows toward the outlet side opening 12 of the fan gate 11. On the other hand, in the narrowed portion 12b of the outlet-side opening 12 that faces the flow of the inert gas, the resin material has already been cooled and solidified to block the passage. The inert gas does not flow back to the upstream side thereof, and the inert gas flows along the longitudinal direction of the thick portion 8.

【００１７】なお、上記の実施例ではファンゲート１１
を例にとって説明したが、該ファンゲート１１と同様に
偏平幅広の出口側開口部をもつフィルムゲート等につい
ても本発明を適用することが可能である。In the above embodiment, the fan gate 11 is used.
However, the present invention can be applied to a film gate or the like having a flat and wide outlet side opening as in the fan gate 11.

【００１８】[0018]

【発明の効果】以上のように本発明によれば、ファンゲ
ート等のゲートの偏平幅広の出口側開口部のうちガスの
流れと直接対向する部分の深さを局部的に小さくして狭
窄部を形成したことにより、その出口側開口部に向かっ
てガスが流れる場合にも、上記の狭窄部から始まるゲー
トシール機能のためにガスがゲートを通ってその上流側
に逆流することがなく、従来のようなガスの逆流による
次のショットの際のトラブルを未然に防止することがで
きる。As described above, according to the present invention, the depth of the portion of the flat wide exit side opening of a gate such as a fan gate, which directly faces the gas flow, is locally reduced to narrow the narrowed portion. Due to the formation of the gas, even when the gas flows toward the outlet side opening, the gas does not flow back through the gate to the upstream side due to the gate sealing function starting from the constriction described above. It is possible to prevent the trouble at the next shot due to the reverse flow of gas as described above.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の一実施例を示す図で、（Ａ）は成形品
とファンゲートとの関係を示す正面説明図、（Ｂ）は同
図（Ａ）のａ−ａ線に沿う断面説明図、（Ｃ）は同図
（Ａ）のｂ−ｂ線に沿う断面説明図。1A and 1B are views showing an embodiment of the present invention, in which FIG. 1A is a front explanatory view showing the relationship between a molded product and a fan gate, and FIG. 1B is a sectional view taken along line aa in FIG. 1A. Explanatory drawing, (C) is sectional explanatory drawing which follows the bb line of the same figure (A).

【図２】射出成形金型のファンゲート付近の断面説明
図。FIG. 2 is an explanatory cross-sectional view near the fan gate of the injection molding die.

【図３】従来の射出成形金型の構造を示すファンゲート
付近の断面説明図。FIG. 3 is an explanatory cross-sectional view near a fan gate showing a structure of a conventional injection molding die.

【図４】図３の要部の斜視図。FIG. 4 is a perspective view of a main part of FIG.

【図５】図４のｅ方向矢視図。5 is a view in the direction of arrow e in FIG.

【図６】図３の金型構造におけるガス逆流時の断面説明
図。FIG. 6 is an explanatory cross-sectional view of the mold structure of FIG. 3 during reverse gas flow.

【符号の説明】[Explanation of symbols]

１…固定型 ２…可動型 ３…キャビティ ６…ガスノズル １１…ファンゲート １２…出口側開口部 １２ａ…一般部 １２ｂ…狭窄部 Ｗ…バンパーフェイシア（成形品） 1 ... Fixed type 2 ... Movable type 3 ... Cavity 6 ... Gas nozzle 11 ... Fan gate 12 ... Exit side opening 12a ... General part 12b ... Narrow part W ... Bumper fascia (molded product)

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 偏平幅広の出口側開口部をもつゲートを
通して射出成形金型のキャビティに樹脂材料を充填する
一方、前記キャビティに臨ませたガスノズルからキャビ
ティ内の樹脂材料にガスを導入して成形品の一部に中空
部を形成するようにした中空射出成形装置において、 前記ゲートの出口側開口部のうちガスの流れ方向と直接
対向する部分の深さを局部的に狭めて狭窄部を形成した
ことを特徴とする中空射出成形装置。1. A resin material is filled into a cavity of an injection molding die through a gate having a flat wide outlet side opening, and a gas is introduced into the resin material in the cavity from a gas nozzle facing the cavity for molding. In a hollow injection molding apparatus in which a hollow portion is formed in a part of a product, a narrowed portion is locally formed by locally narrowing the depth of a portion of the opening on the outlet side of the gate, which directly faces the gas flow direction. A hollow injection molding device characterized in that
JP18983893A 1993-07-30 1993-07-30 Hollow injection molding equipment Expired - Lifetime JP3036309B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP18983893A JP3036309B2 (en) 1993-07-30 1993-07-30 Hollow injection molding equipment

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP18983893A JP3036309B2 (en) 1993-07-30 1993-07-30 Hollow injection molding equipment

Publications (2)

Publication Number Publication Date
JPH0740374A true JPH0740374A (en) 1995-02-10
JP3036309B2 JP3036309B2 (en) 2000-04-24

Family

ID=16248059

Family Applications (1)

Application Number Title Priority Date Filing Date
JP18983893A Expired - Lifetime JP3036309B2 (en) 1993-07-30 1993-07-30 Hollow injection molding equipment

Country Status (1)

Country Link
JP (1) JP3036309B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006281448A (en) * 2005-03-31 2006-10-19 Nishikawa Kasei Co Ltd Injection mold of ring-shaped product made of resin

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006281448A (en) * 2005-03-31 2006-10-19 Nishikawa Kasei Co Ltd Injection mold of ring-shaped product made of resin
JP4585901B2 (en) * 2005-03-31 2010-11-24 ダイキョーニシカワ株式会社 Plastic ring-shaped injection mold

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