JP2997395B2 - Injection mold - Google Patents
Injection moldInfo
- Publication number
- JP2997395B2 JP2997395B2 JP6331472A JP33147294A JP2997395B2 JP 2997395 B2 JP2997395 B2 JP 2997395B2 JP 6331472 A JP6331472 A JP 6331472A JP 33147294 A JP33147294 A JP 33147294A JP 2997395 B2 JP2997395 B2 JP 2997395B2
- Authority
- JP
- Japan
- Prior art keywords
- gate
- gate cutter
- tip
- cutter
- flat
- 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)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、コンパクトディスクや
光ディスク等のディスク成形用金型に関する。従来、金
型内でゲートカッタのみの駆動でゲートを剪断するもの
として、図４ないし図５に示す形式のものがある。この
タイプはゲートカッタ１の先端部を２段の同心円筒状に
形成し、先端の小径円筒部１ａは型締時にダイス２とゲ
ート厚ｔのクリアランスとゲートランド部ｇを設けた構
造となっている。そのため、ゲートランド部ｇによりキ
ャビティ３への流入樹脂の整流は行なわれるものの、ゲ
ートランド部からキャビティー３への樹脂流路が屈曲し
ているため、樹脂の流動抵抗が増大し、それ故スプルー
の離型性を悪化させる欠点があった。さらに、ゲートカ
ッタ１の微小な傾きでもゲート厚ｔが小径円筒部１ａの
円周方向で均一でなくなるため、キャビティ３への樹脂
の充填に際し、円周方向での樹脂の圧力伝達が不均一と
なり、円周方向での樹脂の内部組織が不均一となり光学
特性や転写特性の均一性を妨げる欠点があった。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a disk such as a compact disk or an optical disk. Conventionally, there is a type shown in FIGS. 4 and 5 for shearing a gate by driving only a gate cutter in a mold. In this type, the tip of the gate cutter 1 is formed in a two-stage concentric cylindrical shape, and the small-diameter cylindrical portion 1a at the tip is provided with a die 2, a clearance of a gate thickness t, and a gate land g at the time of mold clamping. I have. Therefore, although the resin flowing into the cavity 3 is rectified by the gate land portion g, the resin flow path from the gate land portion to the cavity 3 is bent, so that the flow resistance of the resin increases, and therefore the sprue is increased. There is a drawback that the mold releasability is deteriorated. Further, even when the gate cutter 1 is slightly inclined, the gate thickness t is not uniform in the circumferential direction of the small-diameter cylindrical portion 1a, so that when the cavity 3 is filled with the resin, the pressure transmission of the resin in the circumferential direction becomes uneven. In addition, there is a disadvantage that the internal structure of the resin in the circumferential direction becomes non-uniform and hinders the uniformity of optical characteristics and transfer characteristics.
【０００２】[0002]
【発明が解決しようとする課題】本発明は、ゲートから
キャビティ内へ流入する樹脂の流動抵抗を低減し、スプ
ルーの離型性を向上させるとともに、常時円周方向にお
けるゲート厚を均一に保ち、製品の光学特性ならびに転
写特性の均一化を図ることを目的とする。SUMMARY OF THE INVENTION The present invention reduces the flow resistance of the resin flowing from the gate into the cavity, improves the releasability of the sprue, and always keeps the gate thickness uniform in the circumferential direction. The objective is to achieve uniform optical and transfer characteristics of the product.
【０００３】[0003]
【課題を解決するための手段】固定金型６内にスプルー
ブッシュ７とダイス２を固設し、前記スプルーブッシュ
７に対向してその先端中心部にアンダーカット部ｅを穿
設せるゲートカッタ１を可動金型９内に摺動可能に設置
してなる射出成形用金型において、前記スプルーブッシ
ュ７の先端部を扁平形状とし、前記スプルーブッシュ７
の樹脂射出口をラッパ状湾曲面ｒに形成させるととも
に、前記ゲートカッタ１の先端面の前記アンダーカット
部ｅ以外を扁平形状のゲートランド部ｇに形成させたこ
とを特徴とする。そして、前記アンダーカット部ｅの直
径ｃをゲートカッタ１の直径ｄの１／２〜１／３の大き
さにしてゲートカッタ１の先端部に扁平形状の大きいゲ
ートランド部ｇを形成させたことである。Means for Solving the Problems A gate cutter 1 in which a sprue bush 7 and a die 2 are fixedly mounted in a fixed mold 6, and an undercut portion e is formed at the center of the front end of the sprue bush 7 opposite to the sprue bush 7. In the injection mold, which is slidably installed in the movable mold 9, the tip of the sprue bush 7 has a flat shape, and the sprue bush 7 has
The resin injection port is formed in a trumpet-shaped curved surface r, and a portion other than the undercut portion e on the end surface of the gate cutter 1 is formed in a flat gate land portion g. The diameter c of the undercut portion e is set to 1/2 to 1/3 of the diameter d of the gate cutter 1 to form a large flat land g at the tip of the gate cutter 1. It is.
【０００４】[0004]
【作用】本発明では、溶融樹脂は扁平な流路ｂ部で整流
されてからキャビティ３へ充填されるため、樹脂の流動
抵抗を減少させるのでスプルーの離型性を向上させる。
またゲートカッタ１の先端部を扁平形状としてゲートカ
ッタの多少の傾きがあっても、ゲート厚ｔの円周方向の
均一性を保持してキャビティー３ヘ樹脂を均一に流入さ
せることにより、製品の光学特性、転写特性を向上させ
る。According to the present invention, since the molten resin is rectified in the flat flow path b and then filled into the cavity 3, the flow resistance of the resin is reduced, so that the releasability of the sprue is improved.
In addition, even if the tip of the gate cutter 1 has a flat shape and the gate cutter has a slight inclination, the uniformity of the gate thickness t in the circumferential direction is maintained, and the resin is uniformly flowed into the cavity 3. To improve the optical characteristics and transfer characteristics.
【０００５】[0005]
【実施例】つぎに、本発明の実施例について図１〜図２
に基づき説明する。図１は本発明のゲートカッタを装備
する金型の断面図、図２は図１の要部拡大図である。４
はノズル、５は固定プラテン、６は固定金型、７は固定
金型に固設されているスプルーブッシュ、８は可動プラ
テン、９は可動金型、１０はゲートカッタの中心孔に挿
通するエジェクターピン、１１はゲートカッタ１を挿通
するスリーブである。本発明は、スプルーブッシュの先
端部を扁平形状に形成し、樹脂射出口をラッパ状湾曲面
ｒに形成している。そして、ゲートカッタの先端部を扁
平形状とし、中心部に穿設されているアンダーカット部
の直径ｃをゲートカッタの直径ｄの約１／２〜１／３と
し、ゲートランド部ｇを大きくした構造にした点であ
る。上記構造としたことにより、溶融樹脂はノズル４か
らスプルーブッシュ７のラッパ状湾曲面ｒに形成された
樹脂射出口を経由してスプルーブッシュ７の扁平な先端
部とゲートカッタ１の先端部の扁平なゲートランド部ｇ
とで形成される扁平な流路ｂで整流されてキャビティー
３へ充填される。図３は、金型、成形機、成形条件を同
一条件にして、本発明にかかるゲートカッタ、及び図４
に示す従来のゲートカッタを用いてディスクを成形した
ときの充填圧力とを比較した実測値である。横軸は時間
（秒）、縦軸は圧力（kgf/cm2）である。図中実線は本
発明、点線は従来例によるときである。この図から本発
明におけるゲート通過時の圧力が９５kgf/cm2となって
おり、従来の１００kgf/cm2に比べて約５％低く、樹脂
がキャビティ内に充填される間本発明の方が全体的に低
下していることが確認された。このことは、ゲートカッ
タ１の先端部を扁平形状にしゲートランド部ｇを大きく
したことにより流路ｂ部で整流されるため樹脂の流動抵
抗が減少していることを物語っており、ダイスの内壁に
加わる圧力が低下し、スプルーの離型性の向上に寄与し
ている。DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
It will be described based on. FIG. 1 is a sectional view of a mold equipped with the gate cutter of the present invention, and FIG. 2 is an enlarged view of a main part of FIG. 4
Is a nozzle, 5 is a fixed platen, 6 is a fixed mold, 7 is a sprue bush fixed to the fixed mold, 8 is a movable platen, 9 is a movable mold, and 10 is an ejector inserted into the center hole of the gate cutter. Pins 11 are sleeves through which the gate cutter 1 is inserted. In the present invention, the tip end of the sprue bush is formed in a flat shape, and the resin injection port is formed in a trumpet-shaped curved surface r. The tip of the gate cutter has a flat shape, the diameter c of the undercut portion formed in the center is set to about 1/2 to 1/3 of the diameter d of the gate cutter, and the gate land g is increased. This is the structure. With the above structure, the molten resin flows from the nozzle 4 through the resin injection port formed on the flared curved surface r of the sprue bush 7 and the flat end of the sprue bush 7 and the flat end of the gate cutter 1. Gate land part g
The flow is rectified by the flat flow path b formed by the above and is filled in the cavity 3. FIG. 3 shows a gate cutter according to the present invention under the same conditions of a mold, a molding machine, and molding conditions, and FIG.
3 is an actually measured value in comparison with a filling pressure when a disk is molded using the conventional gate cutter shown in FIG. The horizontal axis is time (seconds), and the vertical axis is pressure (kgf / cm2). In the figure, the solid line is for the present invention, and the dotted line is for the conventional example. From this figure, the pressure at the time of passing through the gate in the present invention is 95 kgf / cm2, which is about 5% lower than the conventional 100 kgf / cm2. It was confirmed that it had decreased. This indicates that the flow resistance of the resin is reduced because the tip of the gate cutter 1 is flattened and the gate land g is enlarged, so that the flow is rectified in the channel b. The pressure applied to the sprue is reduced, which contributes to the improvement of the releasability of the sprue.
【０００６】[0006]
【発明の効果】本発明によれば、ゲートカッタ先端部を
扁平面にし、その中心部に穿設せるアンダーカット部の
直径ｃをゲートカッタの直径ｄの１／２以下としてゲー
トランド部ｇを大きくしたことにより、キャビティー３
へ流入する樹脂の流動抵抗が減少し、スプルーの離型性
が向上した。さらに、離型性の向上により、従来ではス
プルー残り等で成形ができなかった成形条件でも成形が
可能（例えばゲートカットのタイミングを遅らせたり、
ゲートカッタ温調温度等の成形条件の設定幅の拡大）と
なった。また、ゲートカッタの先端部を扁平面としたこ
とにより、ゲートカッタの多少の傾きがあってもゲート
厚ｔの円周方向での均一性が保たれるためゲートからキ
ャビティへ樹脂は均一に流入されるので製品の光学特性
及び転写特性を向上させるとともに、ゲートカッタの先
端部の形状が従来に比べ複雑でないので該部の加工が簡
略化され、保守も容易である等の効果がある。According to the present invention, the tip of the gate cutter is made flat, and the diameter c of the undercut portion formed at the center thereof is set to be not more than 1/2 of the diameter d of the gate cutter, and the gate land portion g is formed. The cavity 3
The flow resistance of the resin flowing into the sprue was reduced, and the releasability of the sprue was improved. Furthermore, due to the improved releasability, molding can be performed even under molding conditions in which molding could not be conventionally performed due to remaining sprues (for example, the timing of gate cutting can be delayed,
The setting range of molding conditions such as gate cutter temperature control temperature was expanded. In addition, since the tip of the gate cutter has a flat surface, even if the gate cutter is slightly inclined, the uniformity of the gate thickness t in the circumferential direction is maintained, so that the resin flows uniformly from the gate to the cavity. Thus, the optical characteristics and transfer characteristics of the product are improved, and the shape of the tip of the gate cutter is less complicated than in the past, so that processing of the portion is simplified and maintenance is easy.
【００１２】[0012]
【図１】本発明にかかる金型の概略を示す断面図。FIG. 1 is a sectional view schematically showing a mold according to the present invention.
【図２】図１の要部の拡大断面図。FIG. 2 is an enlarged sectional view of a main part of FIG.
【図３】本発明と従来例によるときの充填圧力の比較線
図。FIG. 3 is a comparison diagram of filling pressures according to the present invention and a conventional example.
【図４】従来の金型の概略を示す断面図。FIG. 4 is a sectional view schematically showing a conventional mold.
【図５】図４の要部の拡大断面図。FIG. 5 is an enlarged sectional view of a main part of FIG. 4;
１ ゲートカッタ、 ２ ダイス、 ３
キャビティ、４ ノズル、 ５ 固定
プラテン、６ 固定金型、７ スプルーブッシュ、
８ 可動プラテン、９ 可動金型、１０ エジ
ェクタピン、 １１ スリーブ、ｂ 流路、
ｃ アンダーカット部直径、ｄ ゲ
ートカッタ先端部直径、 ｅ アンダーカット部、ｇ
ゲートランド部、 ｔ ゲート厚1 gate cutter, 2 dice, 3
Cavity, 4 nozzles, 5 fixed platen, 6 fixed mold, 7 sprue bush,
8 movable platen, 9 movable mold, 10 ejector pin, 11 sleeve, b flow path,
c Undercut diameter, d Gate cutter tip diameter, e Undercut, g
Gate land, t Gate thickness
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平６−143364（ＪＰ，Ａ) 特開 平５−285994（ＪＰ，Ａ) 特開 平６−304974（ＪＰ，Ａ) 特開 平６−290491（ＪＰ，Ａ) 特開 平６−55586（ＪＰ，Ａ) 特開 平１−182018（ＪＰ，Ａ) 特開 平８−112840（ＪＰ，Ａ) 特開 平７−68604（ＪＰ，Ａ) 実開 平５−56421（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) B29C 45/26 - 45/44 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-143364 (JP, A) JP-A-5-285994 (JP, A) JP-A-6-304974 (JP, A) JP-A-6-304974 290491 (JP, A) JP-A-6-55586 (JP, A) JP-A-1-182018 (JP, A) JP-A 8-112840 (JP, A) JP-A-7-68604 (JP, A) Hira 5-56421 (JP, U) (58) Field surveyed (Int. Cl. 7 , DB name) B29C 45/26-45/44
Claims (2)
（７）とダイス（２）を固設し、前記スプルーブッシュ
（７）に対向してその先端中心部にアンダーカット部
（ｅ）を穿設せるゲートカッタ（１）を可動金型（９）
内に摺動可能に設置してなる射出成形用金型において、
前記スプルーブッシュ（７）の先端部を扁平形状とし、
該スプルーブッシュ（７）の樹脂射出口をラッパ状湾曲
面（ｒ）に形成させるとともに、前記ゲートカッタ
（１）の先端面の前記アンダーカット部（ｅ）以外を扁
平形状のゲートランド部（ｇ）としたことを特徴とする
射出成形用金型。1. A sprue bush (7) and a die (2) are fixedly installed in a fixed mold (6), and an undercut portion (e) is provided at the center of the tip of the sprue bush (7). Movable mold (9) with gate cutter (1) to be pierced
In the injection mold that is slidably installed inside,
The tip of the sprue bush (7) has a flat shape,
The sprue bush (7) has a resin injection port with a trumpet shape
An injection molding die formed on a surface (r), wherein a portion other than the undercut portion (e) at the tip end surface of the gate cutter (1) is a flat gate land portion (g).
し、該ゲートカッタ先端中心部に穿設されるアンダーカ
ット部（ｅ）の直径（ｃ）をゲートカッタの直径（ｄ）
の１／２〜１／３として、ゲートカッタ（１）の先端部
に扁平形状のゲートランド部（ｇ）を形成させたことを
特徴とする請求項１記載の射出成形用金型。2. The gate cutter (1) has a flat front end surface, and the diameter (c) of an undercut portion (e) formed at the center of the front end of the gate cutter is determined by the diameter (d) of the gate cutter.
The injection mold according to claim 1, wherein a flat gate land (g) is formed at the tip of the gate cutter (1/3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6331472A JP2997395B2 (en) | 1994-12-12 | 1994-12-12 | Injection mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6331472A JP2997395B2 (en) | 1994-12-12 | 1994-12-12 | Injection mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08156038A JPH08156038A (en) | 1996-06-18 |
| JP2997395B2 true JP2997395B2 (en) | 2000-01-11 |
Family
ID=18244033
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6331472A Expired - Fee Related JP2997395B2 (en) | 1994-12-12 | 1994-12-12 | Injection mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2997395B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3934775B2 (en) | 1998-02-25 | 2007-06-20 | 富士フイルム株式会社 | Injection molding method and injection mold |
| CN102029690A (en) * | 2010-10-29 | 2011-04-27 | 深圳创维－Rgb电子有限公司 | Hot nozzle sprue bush |
-
1994
- 1994-12-12 JP JP6331472A patent/JP2997395B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08156038A (en) | 1996-06-18 |
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