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
Application number
JP4883583A
Other languages
Japanese (ja)
Other versions
JPS59176026A (en
Inventor
Yoshitaka Ishiguro
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.)
Nihon Plast Co Ltd
Original Assignee
Nihon Plast 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 Nihon Plast Co Ltd filed Critical Nihon Plast Co Ltd
Priority to JP4883583A priority Critical patent/JPS59176026A/en
Publication of JPS59176026A publication Critical patent/JPS59176026A/en
Publication of JPH0213886B2 publication Critical patent/JPH0213886B2/ja
Granted legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14Injection 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
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/0025Preventing 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.

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

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)

【特許請求の範囲】[Claims] 1 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。
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.
JP4883583A 1983-03-25 1983-03-25 Manufacture of molded article made of synthetic resin Granted JPS59176026A (en)

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)

* Cited by examiner, † Cited by third party
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

Also Published As

Publication number Publication date
JPS59176026A (en) 1984-10-05

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