JPH0195007A - Molding method for boss section of resin molded product - Google Patents
Molding method for boss section of resin molded productInfo
- Publication number
- JPH0195007A JPH0195007A JP25417487A JP25417487A JPH0195007A JP H0195007 A JPH0195007 A JP H0195007A JP 25417487 A JP25417487 A JP 25417487A JP 25417487 A JP25417487 A JP 25417487A JP H0195007 A JPH0195007 A JP H0195007A
- Authority
- JP
- Japan
- Prior art keywords
- boss
- section
- mold
- opening
- molded product
- 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.)
- Pending
Links
- 229920005989 resin Polymers 0.000 title claims abstract description 20
- 239000011347 resin Substances 0.000 title claims abstract description 20
- 238000000465 moulding Methods 0.000 title claims abstract description 12
- 238000000034 method Methods 0.000 title claims description 7
- 239000012530 fluid Substances 0.000 claims abstract description 5
- 239000000463 material Substances 0.000 abstract description 8
- 238000000748 compression moulding Methods 0.000 abstract description 4
- 238000002347 injection Methods 0.000 abstract description 4
- 239000007924 injection Substances 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 239000011148 porous material Substances 0.000 abstract 1
- 238000001746 injection moulding Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 238000007664 blowing Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
- B29C45/1703—Introducing an auxiliary fluid into the mould
- B29C45/174—Applying a pressurised fluid to the outer surface of the injected material inside the mould cavity, e.g. for preventing shrinkage marks
-
- 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
- B29C45/1734—Nozzles therefor
- B29C45/1736—Nozzles therefor provided with small holes permitting the flow of gas therethrough, e.g. using a porous element of sintered material
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Casting Or Compression Moulding Of Plastics Or The Like (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、樹脂成形品のボス部に発生し易いひげを防止
するための樹脂成形品のボス部の成形方法に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for molding a boss portion of a resin molded product to prevent whiskers that tend to occur on the boss portion of the resin molded product.
〈従来の技術〉
従来、樹脂成形品の平坦面の裏面側にボス部を成形する
場合には、肉厚の違いにより冷え易い部分と冷え難い部
分とが隣接することとなり、先に冷え易い部分が冷却固
化して圧力が加わらなくなった状態で、後から冷え難い
部分が冷却固化して体積収縮するため、先に冷却固化し
た表面に生じる凹みであるひけが発生し易いことが知ら
れている。このひけが製品の表面に発生すると外観の品
質低下を生じる問題となる。<Conventional technology> Conventionally, when a boss part is molded on the back side of a flat surface of a resin molded product, a part that cools easily and a part that does not cool easily are adjacent to each other due to the difference in wall thickness, and the part that cools easily first. It is known that sink marks, which are dents that appear on the surface that has cooled and solidified first, are likely to occur because the parts that are difficult to cool later solidify and shrink in volume when the surface is cooled and solidified and no pressure is applied. . When this sink mark occurs on the surface of the product, it becomes a problem that the quality of the appearance deteriorates.
そこで、例えば特公昭５７−４７０１１号公報には、ボ
ス部近傍の肉厚を好適に変化させるように形状を工夫す
ることにより、冷却固化時間の差を減少して、ひけの発
生を防止するようにしたものが開示されている。また、
射出圧縮成形によれば、溶融樹脂の充填後金型の圧縮力
によって樹脂材料を加圧成形して、樹脂材料の冷却収縮
に応じて形状が変らないように圧縮力を好適に減少する
ことから、ひけを防止することができる。Therefore, for example, Japanese Patent Publication No. 57-47011 discloses a method to reduce the difference in cooling solidification time and prevent the occurrence of sink marks by devising the shape so that the wall thickness near the boss portion is suitably changed. What has been done is disclosed. Also,
According to injection compression molding, the resin material is pressure-molded by the compression force of the mold after filling with molten resin, and the compression force is suitably reduced so that the shape does not change as the resin material cools and shrinks. , can prevent sink marks.
〈発明が解決しようとする問題点）
しかしながら、形状を工夫して対処する場合にはボス部
の多種多様の形状に対応して金型を製作したり修正する
ことが煩雑化しがちであり、また射出圧縮成形にあって
は専用の成形機が必要となり、製造コストが高臆すると
いう問題がある。<Problems to be Solved by the Invention> However, when solving the problem by devising the shape, it tends to be complicated to manufacture and modify molds corresponding to the various shapes of the boss portion, and Injection compression molding requires a special molding machine, which raises the problem of high manufacturing costs.
このような従来技術の開閉点に鑑み、本発明の主な目的
は、簡単な構造でひけを防止し得る樹脂成形品のボス部
の成形方法を提供することにある。In view of such opening/closing points in the prior art, the main object of the present invention is to provide a method for molding a boss portion of a resin molded product that can prevent sink marks with a simple structure.
〈問題点を解決するための手段〉
このような目的は、本発明によれば、樹脂成形品の真面
側にボス部を成形する方法であって、前記ボス部のボス
孔の底部を前記裏面側から加圧流体により加圧すること
を特徴とする樹脂成形品のボス部の成形方法を提供する
ことにより達成される。<Means for Solving the Problems> According to the present invention, an object of the present invention is to provide a method for molding a boss portion on the front side of a resin molded product, the bottom of the boss hole of the boss portion being This is achieved by providing a method for molding a boss portion of a resin molded product, which is characterized in that the boss portion of a resin molded product is pressurized from the back side with a pressurized fluid.
〈作用〉
このように、ボス部のボス孔の底部を加圧流体により加
圧することにより、ボス部の基部の駄肉がアンダーカッ
ト処理されて、ボス部の基部と他の部分との肉厚の変化
を減少させることができるため、ひけが発生することを
防止できる。<Operation> In this way, by pressurizing the bottom of the boss hole of the boss part with the pressurized fluid, the waste material at the base of the boss part is undercut, and the thickness between the base of the boss part and other parts is reduced. Since it is possible to reduce changes in the amount of water, it is possible to prevent sink marks from occurring.
〈実施例〉
以下、本発明の好適実施例を添付の図面について詳しく
説明する。<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
第１図は、本発明が適用された射出成形装置のボス部成
形用金型を示す断面図である。図の上方に配設された上
部金型１と下方に配設された下部金型２とが所定の間隔
をもって互いに対向しており、両者の間の部分にはキャ
ビティ部３が郭成されている。このキャビティ部３には
図示されないノズルから噴出された溶融状態の樹脂材料
４が充填され、その樹脂材料４が冷却固化して製品とな
る。FIG. 1 is a sectional view showing a mold for forming a boss portion of an injection molding apparatus to which the present invention is applied. An upper mold 1 placed at the top of the figure and a lower mold 2 placed at the bottom face each other at a predetermined interval, and a cavity 3 is formed in the area between them. There is. This cavity portion 3 is filled with a molten resin material 4 ejected from a nozzle (not shown), and the resin material 4 is cooled and solidified to become a product.
製品にボス部５を一体的に形成するべく、下部金型２に
は両金型１．２間のキャビティ部３に開口する孔６が穿
設されていると共に、孔６の下部には上方に向けて凸形
状断面の円筒形状をなすボス用金型７が固着されている
。このボス用金型７の小径部分であるボスビン部９によ
り、有底形状のボス孔８が形成されることとなる。In order to integrally form the boss portion 5 on the product, the lower mold 2 is provided with a hole 6 that opens into the cavity portion 3 between the two molds 1. A boss mold 7 having a cylindrical shape with a convex cross section is fixed. A boss hole 8 with a bottom is formed by the boss bottle portion 9, which is a small diameter portion of the boss mold 7.
ボス用金型７内には、ボス用金型７の図の下方の軸線方
向端面に開口すると共にボスピン部９の先端部１１近傍
に至る通路１２が軸心に沿って穿設されている。孔６の
下方の下部金型２内には、加圧流体としての圧縮空気の
供給源（図示せず）と通路１１とを連通ずる圧縮空気の
供給通路１３が形成されている。更に、ボスビン部９の
先端部１１には、供給通路１３を介して通路１２に供給
される圧縮空気をキャビティ部３内に噴出させるため、
内径０．０５〜０．１ｍｍ程度の複数の微小孔１４が例
えばレーザ加工により穿設されている。尚、圧縮空気の
圧力は３〜７ｋｇ／ａ！にすると良い。Inside the boss mold 7, a passage 12 is bored along the axis, opening at the lower axial end face of the boss mold 7 in the figure and reaching the vicinity of the tip 11 of the boss pin part 9. A compressed air supply passage 13 is formed in the lower mold 2 below the hole 6 and communicates the passage 11 with a supply source (not shown) of compressed air as a pressurized fluid. Further, the tip end 11 of the boss bottle part 9 is provided with a structure for blowing compressed air supplied to the passage 12 through the supply passage 13 into the cavity part 3.
A plurality of microholes 14 having an inner diameter of approximately 0.05 to 0.1 mm are bored by, for example, laser machining. In addition, the pressure of compressed air is 3 to 7 kg/a! It's good to do this.
このようにして構成された金型にあっては、前記したよ
うにキャビティ部３内に樹脂材料４を充填した後に圧縮
空気を微小孔１４から噴射することにより、この圧縮空
気によりボス孔８の底部を形成する部分の樹脂材料４が
加圧されて、図に示されるようにボス孔８の底部に四部
１５が形成される。この凹部１５が形成されることによ
りボス部５の基部の駄肉がアンダーカット処理されたこ
ととなり、ボス部５の基部と他の平坦部との間の肉厚の
変化が減少される。従って、肉厚の差による冷却同化時
間の差が小さくなるため、ひけが発生することを防止で
きる。In the mold configured in this way, compressed air is injected from the micro holes 14 after the resin material 4 is filled into the cavity 3 as described above, so that the boss holes 8 are filled with the compressed air. The resin material 4 in the portion forming the bottom is pressurized to form a four part 15 at the bottom of the boss hole 8 as shown in the figure. By forming this concave portion 15, the waste material at the base of the boss portion 5 is undercut, and the variation in wall thickness between the base portion of the boss portion 5 and other flat portions is reduced. Therefore, the difference in cooling assimilation time due to the difference in wall thickness is reduced, so it is possible to prevent sink marks from occurring.
尚、本実施例にあっては、射出成形について示したが、
射出成形に限ることなく熱可塑性樹脂の成形全般に用い
ることができる。Although injection molding was shown in this example,
It can be used for general molding of thermoplastic resins without being limited to injection molding.
〈発明の効果〉
このように本発明によれば、樹脂成形品のボス部を成形
する場合に、ボス部の形状及び肉厚を考慮した金型を製
作することなく、また射出圧縮成形などの専用の成形機
を用いることなく、ひけの無い高品質の外観を有する製
品を簡単に成形することができるため、その効果は極め
て大である。<Effects of the Invention> As described above, according to the present invention, when molding the boss portion of a resin molded product, there is no need to manufacture a mold that takes into account the shape and wall thickness of the boss portion, and it is possible to use injection compression molding or the like. The effect is extremely large because it is possible to easily mold products with a high-quality appearance without sink marks without using a special molding machine.
第１図は、本発明が適用されたボス部を成形するための
金型の構造を示す断面図である。
１・・・上部金型 ２・・・下部金型３・・・キ
ャビティ部 ４・・・樹脂材料５・・・ボス部
６・・・孔FIG. 1 is a sectional view showing the structure of a mold for molding a boss portion to which the present invention is applied. 1... Upper mold 2... Lower mold 3... Cavity part 4... Resin material 5... Boss part
6...hole
Claims (1)
より加圧することを特徴とする樹脂成形品のボス部の成
形方法。[Scope of Claims] A method of molding a boss portion on the back side of a resin molded product, the resin molded product characterized in that the bottom of the boss hole of the boss portion is pressurized from the back side with pressurized fluid. How to form the boss part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25417487A JPH0195007A (en) | 1987-10-08 | 1987-10-08 | Molding method for boss section of resin molded product |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25417487A JPH0195007A (en) | 1987-10-08 | 1987-10-08 | Molding method for boss section of resin molded product |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0195007A true JPH0195007A (en) | 1989-04-13 |
Family
ID=17261258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25417487A Pending JPH0195007A (en) | 1987-10-08 | 1987-10-08 | Molding method for boss section of resin molded product |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0195007A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0485726A2 (en) * | 1990-11-15 | 1992-05-20 | Möller Werke GmbH | Nozzle for injecting gas into the cavity of a mould for plastic material, in particular an injection mould |
| JPH0467023U (en) * | 1990-10-17 | 1992-06-15 | ||
| JPH0557754A (en) * | 1991-09-02 | 1993-03-09 | Taiho Kogyo Kk | Gas pressure feed mold |
| CH683976A5 (en) * | 1991-08-29 | 1994-06-30 | Schoeller Plast Ag | Gas injection unit for internal gas pressure sprayer. |
-
1987
- 1987-10-08 JP JP25417487A patent/JPH0195007A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0467023U (en) * | 1990-10-17 | 1992-06-15 | ||
| EP0485726A2 (en) * | 1990-11-15 | 1992-05-20 | Möller Werke GmbH | Nozzle for injecting gas into the cavity of a mould for plastic material, in particular an injection mould |
| CH683976A5 (en) * | 1991-08-29 | 1994-06-30 | Schoeller Plast Ag | Gas injection unit for internal gas pressure sprayer. |
| JPH0557754A (en) * | 1991-09-02 | 1993-03-09 | Taiho Kogyo Kk | Gas pressure feed mold |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0767716B2 (en) | Injection molding method of thermoplastic resin molded product and injection molding die | |
| JPH0195007A (en) | Molding method for boss section of resin molded product | |
| JP2896495B2 (en) | Equipment for manufacturing caps made of synthetic resin | |
| CN1539623B (en) | Blowing injection moulded vessel with holes and method of and appts. for such vessel | |
| JPH0462118A (en) | Method for molding of hollow resin molded item | |
| JP3044631B2 (en) | Molding method of pull cap and mold device therefor | |
| JP3300531B2 (en) | Injection molding method and its mold | |
| JP2905420B2 (en) | Mold for cap injection molding | |
| JP3240353B2 (en) | Mold for thin-walled molded products and molding method | |
| WO1997016293A1 (en) | Valve gate type injection molding method and apparatus therefor | |
| CN220593885U (en) | Gas-assisted forming mechanism suitable for injection mold | |
| JPH05162174A (en) | Tube container and production thereof | |
| JPH0478511A (en) | Hollow molded form of resin | |
| JPH0880553A (en) | Injection mold | |
| JPH07223246A (en) | Manufacture and device for injection molded plastic product | |
| JPS59127740A (en) | Plastic injection molding apparatus | |
| CN206690465U (en) | A kind of eyeglass jetting mold with molding function | |
| JPS63281818A (en) | Injection mold assembly | |
| JPH0136767B2 (en) | ||
| JPH0723223Y2 (en) | Gas press-fitting mold | |
| JPH02215516A (en) | Method and mold for injection molding of hollow molded product | |
| JPS646269Y2 (en) | ||
| JPH07106587B2 (en) | Molding method of thick cap and its cap | |
| JPH07137071A (en) | Gas injection nozzle | |
| JP3719660B2 (en) | Injection mold for molded article with film and method for producing molded article with film |