JPH0213886B2 - - Google Patents
Info
- Publication number
- JPH0213886B2 JPH0213886B2 JP4883583A JP4883583A JPH0213886B2 JP H0213886 B2 JPH0213886 B2 JP H0213886B2 JP 4883583 A JP4883583 A JP 4883583A JP 4883583 A JP4883583 A JP 4883583A JP H0213886 B2 JPH0213886 B2 JP H0213886B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- sink
- product
- control member
- sink marks
- 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
Links
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 229920005989 resin Polymers 0.000 claims description 8
- 239000011347 resin Substances 0.000 claims description 8
- 229920003002 synthetic resin Polymers 0.000 claims description 6
- 239000000057 synthetic resin Substances 0.000 claims description 6
- 239000011162 core material Substances 0.000 description 4
- 239000011800 void material Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000006082 mold release agent Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000010959 steel Substances 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
- B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
-
- 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
- B29C45/0025—Preventing defects on the moulded article, e.g. weld lines, shrinkage marks
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Injection Moulding Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】
本発明は、ひけを防止した合成樹脂成形品の製
造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a synthetic resin molded article that prevents sink marks.
従来の合成樹脂成形品の製造方法として、ハン
ドルの製造例を第１図並びに第２図を参照して述
べると、第１図は従来より用いられている金型に
より成形されたハンドルスポーク部５の斜視図で
あり、第２図は、第１図のＡ−Ａ断面図である。
該図の如きハンドルを製造するには、ハンドル成
形用金型に芯材４をセツトした後、型閉して形成
されたキヤビテイ内に溶融樹脂を射出し、冷却固
化することによつて行なう。 As a conventional method for manufacturing synthetic resin molded products, an example of manufacturing a handle will be described with reference to FIGS. 1 and 2. FIG. FIG. 2 is a sectional view taken along line AA in FIG. 1.
In order to manufacture a handle as shown in the figure, a core material 4 is set in a handle mold, the mold is closed, molten resin is injected into a cavity, and the resin is cooled and solidified.
しかしながら、このような従来のハンドル製造
方法にあつては、スポーク部５に於て薄肉部２か
ら厚肉部３′へと肉厚が急激に変化する個所が在
ることにより、更には芯材４の形状及び配置によ
り型内において溶融樹脂の乱流を引起し易くなつ
ているため製品厚肉部３′の表面にひけ３が発生
し易かつた。このひけ３の位置と程度を正確に予
測する事は難しく、予め金型寸法にこれを織込ん
で補正する事ができなかつた。従つて得られたス
ポーク部５の稜線１２も鮮明に出ないという問題
点があつた。なお、図中１はハンドルのリング部
である。 However, in such a conventional handle manufacturing method, since there is a portion in the spoke portion 5 where the wall thickness changes rapidly from the thin wall portion 2 to the thick wall portion 3', the core material The shape and arrangement of 4 tend to cause turbulent flow of the molten resin in the mold, so that sink marks 3 tend to occur on the surface of the thick part 3' of the product. It is difficult to accurately predict the position and extent of this sink mark 3, and it has not been possible to incorporate this into the mold dimensions in advance to correct it. Therefore, there was a problem that the ridge lines 12 of the obtained spoke portions 5 were not clearly visible. Note that 1 in the figure is a ring portion of the handle.
本発明は、このような従来の問題点に着目して
なされたもので、製品におけるひけの発生し易い
個所の裏面側に相当する型キヤビテイ面からひけ
制御部材を金型内に立設して、型キヤビテイ内に
溶融樹脂を射出、固化せしめ、上記ひけ制御部材
の先端部周辺でボイドを発生させて製品表面のひ
けを防止することを特徴とする合成樹脂成形品の
製造方法を要旨とするものである。 The present invention has been made in view of these conventional problems, and includes a sink control member that is erected in the mold from the mold cavity surface corresponding to the back side of the part of the product where sink marks are likely to occur. , a method for producing a synthetic resin molded product characterized by injecting and solidifying molten resin into a mold cavity to generate voids around the tip of the sink control member to prevent sink marks on the surface of the product. It is something.
以下、本発明を図面に基づいて説明すると、第
３図並びに第４図は、本発明の一実施例を示す図
である。まず本発明製造方法で用いられる金型の
構成を説明すると、第３図の如く下型７に形成さ
れた製品裏面側の型キヤビテイ面８からひけ制御
部材９を金型内のひけの発生し易い個所に立設す
る。次いで芯材４をセツトし、上型６を型閉し、
形成されたキヤビテイ内に溶融合成樹脂を射出
し、固化してから離型して製品とする。 Hereinafter, the present invention will be explained based on the drawings. FIG. 3 and FIG. 4 are diagrams showing one embodiment of the present invention. First, to explain the configuration of the mold used in the manufacturing method of the present invention, as shown in FIG. Install it in a convenient location. Next, the core material 4 is set, the upper mold 6 is closed,
Molten synthetic resin is injected into the formed cavity, solidified, and then released from the mold to form a product.
前記本発明で用いられるひけ制御部材９は耐熱
性で、且つ熱容量の比較的大きいものであり、立
設する際には成形品の離型が容易であるようにそ
の表面には離型剤を施しておくとよい。材質とし
ては、例えば金属鋼材が好適である。このような
構成の金型内で連続成形を行なえば、ひけ制御部
材９の先端部１０には、樹脂熱が残留するため他
のキヤビテイ面より高温となり、成形品硬化時に
於て、該先端部１０の周辺に在る樹脂は最も長く
流動性を保持する事ができ、それ故に該先端部１
０の周辺にはボイド１１が形成され、その反作用
として、従来は、ひけが形成されていた製品表面
側にはひけが発生しない結果となる。 The sink control member 9 used in the present invention is heat resistant and has a relatively large heat capacity, and when it is installed upright, a mold release agent is applied to its surface so that the molded product can be easily released. It is a good idea to give it. For example, metal steel is suitable as the material. If continuous molding is performed in a mold with such a configuration, resin heat remains at the tip 10 of the sink control member 9, resulting in a higher temperature than other cavity surfaces, and when the molded product hardens, the tip 10 The resin around the tip 1 can maintain fluidity for the longest time, and therefore the resin around the tip 1
A void 11 is formed around the void 11, and as a reaction, no sink mark occurs on the surface of the product, where sink marks were conventionally formed.
以上説明してきたように、本発明によれば、ひ
けの発生し易い個所の製品裏面側の型キヤビテイ
面からひけ制御部材を金型内に立設して成形品内
部にボイドを形成することによつて、ひけの原因
となる材料収縮をそのボイドで相殺するようにし
たため、製品表面のひけを防止でき、寸法精度が
高まり、成形品の稜線を鮮明に出すことができる
という効果が得られる。 As explained above, according to the present invention, voids can be formed inside the molded product by erecting the sink control member in the mold from the mold cavity surface on the back side of the product where sink marks are likely to occur. Therefore, since the material shrinkage that causes sink marks is offset by the voids, it is possible to prevent sink marks on the product surface, improve dimensional accuracy, and make the ridge lines of the molded product clearly visible.
以上、本発明をハンドル製造に適用した場合に
ついて説明したが、本発明はこれに限られるもの
ではなく、各種の合成樹脂成形品のひけ防止に効
果のあるものである。 Although the present invention has been described above in the case where it is applied to handle manufacturing, the present invention is not limited to this, and is effective in preventing sink marks on various synthetic resin molded products.
第１図は従来の金型により成形されたハンドル
スポーク部の斜視図、第２図は、第１図のＡ−Ａ
断面図、第３図は本発明の一実施態様を示す金型
の断面図、第４図は第３図のＢ−Ｂ断面図であ
る。
１……リング部、２……薄肉部、３……ひけ、
３′……厚肉部、４……芯材、５……スポーク部、
６……上型、７……下型、８……キヤビテイ面、
９……ひけ制御部材、１０……先端部、１１……
ボイド、１２……稜線。
Fig. 1 is a perspective view of a handle spoke part molded by a conventional mold, and Fig. 2 is an A-A in Fig. 1.
3 is a sectional view of a mold showing one embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB in FIG. 3. 1...Ring part, 2...Thin wall part, 3...Sink,
3'... Thick wall part, 4... Core material, 5... Spoke part,
6... Upper mold, 7... Lower mold, 8... Cavity surface,
9...Sink control member, 10...Tip portion, 11...
Void, 12...Ridge.
Claims (1)
に相当する型キヤビテイ面からひけ制御部材を金
型内に立設して、型キヤビテイ内に溶融樹脂を射
出、固化せしめ、上記ひけ制御部材の先端部周辺
でボイドを発生させて製品表面のひけを防止する
ことを特徴とする合成樹脂成形品の製造方法。1. A sink control member is erected in the mold from the mold cavity surface corresponding to the back side of the part where sink marks are likely to occur in the product, and molten resin is injected into the mold cavity and solidified, and the tip of the sink control member is A method for producing a synthetic resin molded product, which is characterized by generating voids around the part to prevent sink marks on the product surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4883583A JPS59176026A (en) | 1983-03-25 | 1983-03-25 | Manufacture of molded article made of synthetic resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4883583A JPS59176026A (en) | 1983-03-25 | 1983-03-25 | Manufacture of molded article made of synthetic resin |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59176026A JPS59176026A (en) | 1984-10-05 |
| JPH0213886B2 true JPH0213886B2 (en) | 1990-04-05 |
Family
ID=12814294
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4883583A Granted JPS59176026A (en) | 1983-03-25 | 1983-03-25 | Manufacture of molded article made of synthetic resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59176026A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0767716B2 (en) * | 1991-01-14 | 1995-07-26 | 新日鐵化学株式会社 | Injection molding method of thermoplastic resin molded product and injection molding die |
| JP2002103395A (en) * | 2000-10-03 | 2002-04-09 | Meiwa Ind Co Ltd | Method of injection molding of synthetic resin and molded article thereof |
-
1983
- 1983-03-25 JP JP4883583A patent/JPS59176026A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59176026A (en) | 1984-10-05 |
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