JP2974615B2 - Hollow mold - Google Patents
Hollow moldInfo
- Publication number
- JP2974615B2 JP2974615B2 JP18042096A JP18042096A JP2974615B2 JP 2974615 B2 JP2974615 B2 JP 2974615B2 JP 18042096 A JP18042096 A JP 18042096A JP 18042096 A JP18042096 A JP 18042096A JP 2974615 B2 JP2974615 B2 JP 2974615B2
- Authority
- JP
- Japan
- Prior art keywords
- movable core
- resin
- stage movable
- gas
- hollow
- 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
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
- B29C45/1705—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 using movable mould parts
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
【０００１】[0001]
【発明の属する技術分野】本発明は中空品成形金型に関
し、特に自動車産業分野において、エンジンルーム内で
使用される気体および液体循環用のパイプ、ダクト、消
音用のレゾネータ等を成形するための中空品成形金型に
関し、その他一般産業分野において、パイプ・ダクトの
他、把手やシャフト、ポンプの吸込口、厚肉部を有する
ケーシング等の肉抜きなどに応用可能な中空品成形金型
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding hollow articles, and more particularly to a mold for forming pipes and ducts for circulating gas and liquid used in an engine room, a resonator for silencing, etc. in the automobile industry. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow product molding die, which is applicable to, in other general industrial fields, pipes, ducts, handles, shafts, suction ports of pumps, hollowing of casings having thick portions, and the like.
【０００２】[0002]
【従来の技術】自動車エンジン等に使用される複雑な形
状の中空管や中空曲管を樹脂材料により製造する方法と
しては、例えば、ガスアシストインジェクション成形法
が知られている。このガスアシストインジェクション成
形法とは、「溶融流動状態の樹脂材料を金型内のキャビ
ティに導入し、次いでこの樹脂材料内に加圧ガスを注入
し、ガス圧により樹脂材料を金型内面に向かって押しつ
けつつ薄肉化し、所定形状の管状体を製造すること」を
特徴とする成形法である。2. Description of the Related Art As a method of manufacturing a hollow tube or a hollow curved tube having a complicated shape used for an automobile engine or the like from a resin material, for example, a gas assist injection molding method is known. This gas-assisted injection molding method refers to "introducing a resin material in a molten and fluidized state into a cavity in a mold, then injecting a pressurized gas into the resin material, and moving the resin material toward the mold inner surface by gas pressure. To produce a tubular body having a predetermined shape ".
【０００３】このガスアシストインジェクション成形法
により図３（ａ）に示すような形状の管状中空品Ｐを成
形する場合、図３（ｂ）に示すように、金型内にキャビ
ティ１を設け、このキャビティ１に樹脂ゲート２より溶
融流動状態の樹脂材料を射出し、樹脂ゲート２より射出
された樹脂がキャビティ１内容積の数十％に達したとき
にガス注入口３より不活性ガスを注入すると、注入され
た不活性ガスは樹脂の溶融粘度の低いところを選択的に
流れるため、管状成形品の中心部に中空部４が形成さ
れ、不活性ガスはさらに樹脂材料を引き伸ばしつつキャ
ビティ内に充満する。そして、所定の冷却時間を経て樹
脂が固化すると、一定圧力で保持されていたガスは注入
口３から排出される。When a tubular hollow article P having a shape as shown in FIG. 3A is formed by this gas assisted injection molding method, a cavity 1 is provided in a mold as shown in FIG. When a molten resin material is injected from the resin gate 2 into the cavity 1 and an inert gas is injected from the gas injection port 3 when the resin injected from the resin gate 2 reaches several tens% of the internal volume of the cavity 1. Since the injected inert gas flows selectively in a portion where the melt viscosity of the resin is low, a hollow portion 4 is formed in the center of the tubular molded product, and the inert gas fills the cavity while further stretching the resin material. I do. When the resin solidifies after a predetermined cooling time, the gas held at a constant pressure is discharged from the inlet 3.
【０００４】この後、金型から取り出された管状成形品
に必要な機械加工を施して、図３（ａ）に示すような形
状の管状中空品を得ることができる。[0004] Thereafter, necessary machining is performed on the tubular molded product taken out of the mold to obtain a tubular hollow product having a shape as shown in FIG.
【０００５】[0005]
【発明が解決しようとする課題】ところが、従来のガス
アシストインジェクション成形法では、成形品の内径
（Ｄ）に対する長さ（Ｌ）の割合（Ｌ／Ｄ）が１０以上
のパイプ状のものは比較的良好に成形しうるが、Ｌ／Ｄ
が２〜６と比較的小さい中空成形品を成形しようとする
と、図３（ｂ）に示すように、キャビティ内に先に射出
された樹脂が流動先端部（ガス注入口と逆側のキャビテ
ィ最奥部）に残存し、管状中空部より肉厚の厚い厚肉部
５が先端部に形成されてしまう。このような厚肉部が形
成される結果、「余分な樹脂材料が必要になるので、
材料コストの上昇を招く。肉が厚い分だけ冷却・固化
に必要な時間が長くなる。局部的に樹脂の収縮率が大
きくなるため、寸法が安定せず、ヒケ・ソリ等が発生し
やすくなる。厚肉部を穿孔して中空にする必要がある
ので、機械加工の量が多く、加工も複雑になる。」等の
問題が生じる。However, in the conventional gas-assisted injection molding method, the ratio of the length (L) to the inner diameter (D) of the molded article (L / D) is not less than 10 pipes. Good molding, but L / D
When a hollow molded article having a relatively small diameter of 2 to 6 is to be molded, as shown in FIG. (A deep portion), and a thick portion 5 thicker than the tubular hollow portion is formed at the distal end. As a result of the formation of such a thick portion, "an extra resin material is required,
This leads to an increase in material costs. The thicker the meat, the longer the time required for cooling and solidification. Since the shrinkage of the resin locally increases, the dimensions are not stable, and sink marks and warpage are likely to occur. Since it is necessary to pierce the thick portion to make it hollow, the amount of machining is large and the machining becomes complicated. And so on.
【０００６】上記のような問題を解決するために本出願
人は、先に、図４に示すように、「厚肉部を形成しやす
い流動樹脂先端部に可動式コア６を配し、可動式コア６
をジョイントシャフト７を介して定荷重発生装置８に連
結する構成とし、キャビティ１ａの容積の２０〜４０％
に相当する溶融樹脂を射出成形機（図示せず）のノズル
からランナー９を経て樹脂ゲート２よりキャビティ１ａ
内に射出後、ガス注入口３から３０〜１５０ｋｇ／ｃｍ
2 に加圧された不活性ガス（Ｎ2 ガス）を注入し、ガス
圧により引き伸ばされた樹脂の流動先端部が可動式コア
６に達すると、可動式コア６が樹脂圧およびガス圧によ
り後退し、さらにガスを供給し続けることによりキャビ
ティ容積が拡大したのと同様の効果を生ずるので、樹脂
の流動先端部が可動式コア６の動きに追随しつつ金型内
面に沿って薄く引き伸ばされ、全体としてほぼ均一な厚
さの薄肉管状成形品を得ることができる。」中空品成形
金型に関する特許出願をした（特願平７−２３６３７３
号）。ところが、管の内径が大きくて（Ｄ≧３０mm）、
長尺（Ｌ≧１５０mm）の物を上記特許出願に係る金型で
製作しようとする場合、管容積の拡大に伴って可動式コ
アの移動によって得られる容積も大きくしなければなら
ないので、次のような不都合なことがある。 (1) 可動部の容積が大きくなると、部分的に薄肉部がで
きるなど成形が不安定となりやすく、ガス射出遅延時間
等の成形条件の幅が狭くなる。 (2) 可動部の容積が大きいほど、無駄な樹脂材料が必要
となる。 (3) 可動式コアの移動量が大きくなるので、より大きな
金型が必要となる。[0006] In order to solve the above-mentioned problem, the applicant of the present invention has previously described, as shown in FIG. Formula core 6
Is connected to a constant load generator 8 via a joint shaft 7, and 20 to 40% of the volume of the cavity 1a.
From the nozzle of the injection molding machine (not shown) through the runner 9 and the resin gate 2 into the cavity 1a.
After injection into the gas injection port 3 from 30 to 150 kg / cm
When a pressurized inert gas (N 2 gas) is injected into the gas turbine 2 and the flow front of the resin stretched by the gas pressure reaches the movable core 6, the movable core 6 is retracted by the resin pressure and the gas pressure. Further, since the same effect as when the cavity volume is expanded by continuing to supply the gas is produced, the flow front portion of the resin is thinly stretched along the inner surface of the mold while following the movement of the movable core 6, It is possible to obtain a thin tubular molded product having a substantially uniform thickness as a whole. "A patent application was filed for a hollow product molding die (Japanese Patent Application No. Hei 7-236373).
issue). However, the inner diameter of the pipe is large (D ≧ 30 mm),
When a long product (L ≧ 150 mm) is to be manufactured using the mold according to the above patent application, the volume obtained by moving the movable core must be increased with the increase in the tube volume. There are such inconveniences. (1) When the volume of the movable part is large, molding tends to be unstable, for example, a thin part is formed, and the range of molding conditions such as gas injection delay time is narrowed. (2) The larger the volume of the movable part, the more wasteful resin material is required. (3) Since the moving amount of the movable core increases, a larger mold is required.
【０００７】本発明は従来の技術の有するこのような問
題点に鑑みてなされたものであって、その目的は、得よ
うとする中空成形品の内径や長さに関わりなく、不要な
厚肉部の生成を抑制し、しかも安定した成形が可能で、
樹脂材料の無駄が少ない中空品成形金型を提供すること
にある。The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide an unnecessary thick wall regardless of the inner diameter and length of a hollow molded product to be obtained. Part formation is suppressed and stable molding is possible.
An object of the present invention is to provide a mold for molding a hollow article with less waste of resin material.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に本発明は、可動式コアを大断面積の第一段可動コアと
小断面積の第二段可動コアの２段構成とし、第二段可動
コアを第一段可動コアと同一方向に移動可能に第一段可
動コア内に配置することとしている。そこで、第一段可
動コアを終端位置まで移動させても厚肉部が存在する場
合には、第一段可動コア内の第二段可動コアを終端位置
まで移動させることにより新たなキャビティを形成し、
このキャビティ内に厚肉部を引き込むことにより、全体
としてほぼ均一な厚さを有する中空品を得ることができ
る。In order to achieve the above object, the present invention provides a movable core having a two-stage structure comprising a first stage movable core having a large sectional area and a second stage movable core having a small sectional area. The two-stage movable core is arranged in the first-stage movable core so as to be movable in the same direction as the first-stage movable core. Therefore, if the thick part exists even when the first stage movable core is moved to the terminal position, a new cavity is formed by moving the second stage movable core in the first stage movable core to the terminal position. And
By drawing the thick portion into the cavity, a hollow article having a substantially uniform thickness as a whole can be obtained.
【０００９】[0009]
【発明の実施の形態】すなわち、本発明は、金型内のキ
ャビティに導入した溶融流動状態の樹脂材料内に加圧ガ
スを注入し、ガス圧により樹脂材料を金型内面に向かっ
て押しつけつつ薄肉化し、キャビティ内を流動する樹脂
の先端部に可動式コアを配し、該可動式コアを定荷重発
生装置に連結した中空品成形金型において、可動式コア
を大断面積の第一段可動コアと小断面積の第二段可動コ
アの２段構成とし、第二段可動コアを第一段可動コアと
同一方向に移動可能に第一段可動コア内に配したことを
特徴としている。More specifically, the present invention provides a method of injecting a pressurized gas into a resin material in a molten and fluidized state introduced into a cavity in a mold and pressing the resin material against the inner surface of the mold by gas pressure. A movable core is arranged at the tip of a resin that is thinned and flows in a cavity, and the movable core is connected to a constant load generator. It has a two-stage configuration of a movable core and a second-stage movable core having a small cross-sectional area, and the second-stage movable core is arranged in the first-stage movable core so as to be movable in the same direction as the first-stage movable core. .
【００１０】上記のように構成される中空品成形金型に
よれば、従来の成形法では厚肉部が形成される流動樹脂
先端部には可動式コアがあり、この可動式コアを２段構
成としたので、第一段可動コアを終端位置まで移動させ
ても厚肉部が存在する場合には、第一段可動コア内の第
二段可動コアを終端位置まで移動させることにより、新
たなキャビティを形成し、このキャビティ内に厚肉部を
引き込むことにより、全体としてほぼ均一な厚さを有す
る中空品を得ることができる。[0010] According to the hollow article molding die configured as described above, in the conventional molding method, there is a movable core at the tip of the fluid resin where a thick portion is formed. Since the thick section exists even when the first-stage movable core is moved to the terminal position, the second-stage movable core in the first-stage movable core is moved to the terminal position. By forming a thick cavity and drawing the thick portion into the cavity, it is possible to obtain a hollow article having a substantially uniform thickness as a whole.
【００１１】[0011]
【実施例】以下に本発明の実施例を図面に基づいて説明
する。図１において、厚肉部を形成しやすい流動樹脂先
端部に第一段可動コア６ａと第二段可動コア６ｂからな
る可動式コアを配し、第二段可動コア６ｂをジョイント
シャフト７を介して定荷重発生装置８に連結する。第一
段可動コア６ａはＡ位置とＢ位置の間を移動可能であ
り、第二段可動コア６ｂは第一段可動コア６ａがＢ位置
に達するまでは第一段可動コア６ａの先端面と面一を保
って移動し、第一段可動コア６ａがＢ位置に達した後
は、第一段可動コア６ａ内のＢ位置とＣ位置の間を移動
可能である（図１は、第一段可動コア６ａと第二段可動
コア６ｂが終端位置まで移動した状態を示す）。定荷重
発生装置８はこれら可動コアの移動に際し、樹脂圧およ
びガス圧に対して適当な大きさの抵抗力で対抗しつつ可
動コアのスムーズな動作を妨げないものであれば、特に
その方式は限定されるものではなく、例えば、バネ、シ
リンダー、油圧シリンダ、エアシリンダ等を用いること
ができる。図１の場合は、定荷重発生装置８を油圧シリ
ンダとし、油圧によりジョイントシャフト７を移動させ
る例を示す。Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a movable core composed of a first stage movable core 6a and a second stage movable core 6b is arranged at the tip of a flowing resin that easily forms a thick portion, and the second stage movable core 6b is connected via a joint shaft 7. To the constant load generator 8. The first stage movable core 6a is movable between the A position and the B position, and the second stage movable core 6b is in contact with the distal end surface of the first stage movable core 6a until the first stage movable core 6a reaches the B position. After moving while keeping the same level and the first stage movable core 6a has reached the B position, it can be moved between the B position and the C position in the first stage movable core 6a (FIG. This shows a state in which the step movable core 6a and the second step movable core 6b have moved to the terminal positions. When the constant load generating device 8 does not hinder the smooth operation of the movable core while resisting the resin pressure and the gas pressure with an appropriate magnitude when moving the movable core, the method is particularly applicable to the method. It is not limited, and for example, a spring, a cylinder, a hydraulic cylinder, an air cylinder, or the like can be used. FIG. 1 shows an example in which the constant load generating device 8 is a hydraulic cylinder and the joint shaft 7 is moved by hydraulic pressure.
【００１２】図１は、上記構成を有する金型によりＬ／
Ｄが４、内径が４０mmの中空曲管（自動車用吸気パイ
プ）を成形した場合であり、その成形法を以下に説明す
る。まず、キャビティ１ａの容積の２０〜４０％に相当
する溶融樹脂を、射出成形機（図示せず）のノズルから
ランナー９を経て樹脂ゲート２よりキャビティ１ａ内に
射出後、ガス注入口３から３０〜１５０ｋｇ／ｃｍ2 に
加圧された不活性ガス（Ｎ2 ガス）を注入すると、先に
キャビティ１ａ内に入った樹脂はガス圧により引き伸ば
されつつ中空部４ａを形成する。樹脂の流動先端部が第
一段可動コア６ａに達すると、第一段可動コア６ａは樹
脂圧およびガス圧により左方に移動しつつ第一段可動コ
アの移動跡外壁に樹脂を押しつけていき、図１に示すよ
うに、第一段可動コア６ａは終端位置Ｂに達する。そし
て、ガス注入口３からさらにガスを注入すると、第二段
可動コア６ｂは樹脂圧およびガス圧により終端位置に停
止した状態の第一段可動コア６ａ内を左方に移動して、
特に厚肉を形成しやすい流動先端中心部の樹脂を第二段
可動コア６ｂの移動跡に引き込んで厚肉部を緩和し、樹
脂溜まり部１０においての肉厚を中空部４ａと略同一と
すると同時に、第一段可動コア６ａおよび第二段可動コ
ア６ｂに接触する部分の肉厚差を小さくし、第二段可動
コア６ｂに接触する部分が先端ディスク部の中心を抜い
ているので、冷却硬化時の収縮の影響を極小に抑えるこ
とができる。なお、得られた成形品は、図１におけるＡ
位置およびＤ位置で切断して目的とする中空曲管を得
る。FIG. 1 shows that the mold having the above-described structure has a L /
This is a case where a hollow curved pipe (intake pipe for automobile) having a diameter D of 4 and an inner diameter of 40 mm is formed, and the forming method is described below. First, a molten resin corresponding to 20 to 40% of the volume of the cavity 1a is injected from the nozzle of the injection molding machine (not shown) into the cavity 1a from the resin gate 2 via the runner 9 and then from the gas injection port 3 to 30. When an inert gas (N 2 gas) pressurized to １５０150 kg / cm 2 is injected, the resin that has previously entered the cavity 1a forms the hollow portion 4a while being stretched by the gas pressure. When the leading end of the resin reaches the first movable core 6a, the first movable core 6a presses the resin against the outer wall of the movement trace of the first movable core while moving leftward by the resin pressure and the gas pressure. As shown in FIG. 1, the first stage movable core 6a reaches the end position B. When the gas is further injected from the gas injection port 3, the second-stage movable core 6b moves leftward in the first-stage movable core 6a stopped at the terminal position by the resin pressure and the gas pressure,
Particularly, it is assumed that the resin at the center of the flow front which easily forms a thick wall is drawn into the movement trace of the second-stage movable core 6b to relieve the thick part, and the thickness in the resin reservoir 10 is made substantially the same as the hollow part 4a. At the same time, the thickness difference between the portions contacting the first-stage movable core 6a and the second-stage movable core 6b is reduced, and the portion contacting the second-stage movable core 6b cuts out the center of the distal end disk portion. The effect of shrinkage during curing can be minimized. In addition, the obtained molded product is A in FIG.
Cut at positions D and D to obtain the desired hollow curved tube.
【００１３】図２は、本発明の別の実施例の金型により
一端がラッパ状の中空品（ラッパ状端面内径８０mm、他
端内径４０mm、長さ１５０mm）を成形する場合であり、
可動コアの動作を、順を追って説明する。FIG. 2 shows a case where a hollow product having a trumpet shape at one end (80 mm inside diameter at the end face, 40 mm inside diameter at the other end, and 150 mm length) is formed by a mold according to another embodiment of the present invention.
The operation of the movable core will be described step by step.
【００１４】図２（ａ）は、可動コアの動作開始時の状
態を示し、キャビティ１の容積の２０〜４０％に相当す
る溶融樹脂を樹脂ゲート２からキャビティ１内に射出
後、ガス注入口３から３０〜１５０ｋｇ／ｃｍ2 に加圧
された不活性ガス（Ｎ2 ガス）を注入すると、中空部４
を形成しつつ樹脂は薄く引き伸ばされ、第一段可動コア
６ａは樹脂の流動先端部およびガス圧により押圧されて
左方に移動し、図２（ｂ）の状態になる。この場合、第
一段可動コア６ａに当接する部分、特にその中心部には
厚肉部１１が形成されているが、さらにガス注入口３か
らガスを注入し続けると、第二段可動コア６ｂが第一段
可動コア６ａ内を左方に移動することにより形成される
新たなキャビティ内に上記厚肉部１１の樹脂が引き込ま
れ、最終的に図２（ｃ）に示すように、樹脂溜まり部１
０においても他と同様に一様な中空部４を有する、全体
としてほぼ均一な厚さを有し、樹脂溜まり部１０の中心
部が抜けて冷却収縮を緩和するようになった薄肉パイプ
状成形品を得ることができる。得られた薄肉パイプ状成
形品を図２（ｃ）のＡ´およびＤで切断し、一端がラッ
パ状の中空品を得る。本例における第一段可動コア６ａ
の移動距離（Ａ→Ｂ）は２５mm、第二段可動コア６ｂの
移動距離（Ｂ→Ｃ）は２０mmであり、同じ中空品につい
て従来の一段式可動コアを用いた場合の移動距離は３５
mmであり、移動距離を約３０％減少させ、前記樹脂溜ま
り部等の無駄な樹脂材料を１／２に減少させることがで
きた。FIG. 2A shows a state at the start of the operation of the movable core. After a molten resin corresponding to 20 to 40% of the volume of the cavity 1 is injected from the resin gate 2 into the cavity 1, the gas injection port is formed. When an inert gas (N 2 gas) pressurized from 3 to 30 to 150 kg / cm 2 is injected, the hollow portion 4
The first stage movable core 6a is pressed by the flow tip of the resin and the gas pressure and moves to the left, forming the state shown in FIG. 2B. In this case, a thick portion 11 is formed at a portion in contact with the first-stage movable core 6a, particularly at a central portion thereof. However, when gas is continuously injected from the gas injection port 3, the second-stage movable core 6b Move into the first movable core 6a to the left, the resin of the thick portion 11 is drawn into a new cavity formed, and finally, the resin pool is accumulated as shown in FIG. Part 1
0 has a uniform hollow portion 4 similarly to the others, has a substantially uniform thickness as a whole, and has a central portion of the resin reservoir portion 10 so that a thin-walled pipe-shaped molding capable of relaxing cooling shrinkage. Goods can be obtained. The obtained thin pipe-shaped molded product is cut at A ′ and D in FIG. 2C to obtain a hollow product having a trumpet-shaped end. First stage movable core 6a in this example
The moving distance (A → B) is 25 mm, the moving distance (B → C) of the second stage movable core 6b is 20 mm, and the traveling distance of the same hollow product when using the conventional one-stage movable core is 35.
mm, the moving distance was reduced by about 30%, and the useless resin material such as the resin pool portion was reduced to half.
【００１５】本発明において用いられる樹脂は、熱可塑
性のエンジニアリングプラスチックと呼ばれる樹脂で、
例えば、ポリアセタール、ポリカーボネート、ポリアミ
ド、ポリフェニレンサルファイド、ポリエステル等の樹
脂単体およびこれらのブレンドやアロイ化したもの、ガ
ラス繊維、炭素繊維やアラミド繊維等で補強されたもの
等を挙げることができる。The resin used in the present invention is a resin called a thermoplastic engineering plastic.
For example, a resin alone such as polyacetal, polycarbonate, polyamide, polyphenylene sulfide, and polyester, and a blend or alloy thereof, a resin reinforced with glass fiber, carbon fiber, aramid fiber, and the like can be given.
【００１６】[0016]
【発明の効果】本発明は上記のとおり構成されているの
で、次の効果を奏する。 全体としてほぼ均一な厚さで冷却時の収縮の影響の
少ない中空品を得ることができる。 大断面の可動コアの移動距離が短くなるので、部分
的な薄肉部が生じず、成形が安定し、ガス射出遅延時間
等の成形条件の範囲が広くなる。 大断面の可動コアの移動距離が短くなるので、無駄
な樹脂材料の量が少なくなり、また、金型の小型化が可
能となる。Since the present invention is configured as described above, the following effects can be obtained. A hollow article having a substantially uniform thickness as a whole and less affected by shrinkage during cooling can be obtained. Since the moving distance of the movable core having a large cross section is short, a partial thin portion is not generated, molding is stable, and the range of molding conditions such as gas injection delay time is widened. Since the moving distance of the movable core having the large cross section is short, the amount of useless resin material is reduced, and the size of the mold can be reduced.
【図１】本発明の中空品成形金型の第一の実施例の側断
面図である。FIG. 1 is a side sectional view of a first embodiment of a mold for forming a hollow article of the present invention.
【図２】本発明の中空品成形金型の第二の実施例の可動
式コアの動作状態を示す図であり、図２（ａ）は可動式
コアの動作開始時の状態を示す側断面図、図２（ｂ）は
第一段可動コアが終端位置に達した状態を示す側断面
図、図２（ｃ）は第二段可動コアが終端位置に達した状
態を示す側断面図である。FIG. 2 is a view showing an operation state of a movable core of a second embodiment of a hollow article molding die according to the present invention, and FIG. 2 (a) is a side sectional view showing a state at the start of operation of the movable core. FIG. 2B is a side sectional view showing a state where the first stage movable core has reached the terminal position, and FIG. 2C is a side sectional view showing a state where the second stage movable core has reached the terminal position. is there.
【図３】図３（ａ）は中空成形品の一実施例の断面図、
図３（ｂ）はその中空品の成形法を説明する図である。FIG. 3A is a sectional view of one embodiment of a hollow molded product.
FIG. 3B is a diagram illustrating a method of forming the hollow article.
【図４】従来の中空品成形金型の側断面図である。FIG. 4 is a side sectional view of a conventional hollow article molding die.
１、１ａ…キャビティ ２…樹脂ゲート ３…ガス注入口 ４、４ａ…中空部 ５、１１…厚肉部 ６…可動式コア ６ａ…第一段可動コア ６ｂ…第二段可動コア ７…ジョイントシャフト ８…定荷重発生装置 ９…ランナー １０…樹脂溜まり部 Ｐ…管状中空品 1, 1a cavity 2 resin gate 3 gas inlet 4, 4a hollow part 5, 11 thick part 6 movable core 6a first stage movable core 6b second stage movable core 7 joint shaft 8 Constant load generator 9 Runner 10 Resin pool P Hollow tubular product
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平７−144336（ＪＰ，Ａ) 特開 平８−323818（ＪＰ，Ａ) 特開 平９−76273（ＪＰ，Ａ) 特開 平６−285895（ＪＰ，Ａ) 特開 平８−267496（ＪＰ，Ａ) 特開 平７−186178（ＪＰ，Ａ) 特開 平７−164486（ＪＰ，Ａ) 特開 平７−32423（ＪＰ，Ａ) 特開 平７−16864（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) B29C 45/26 B29C 45/00 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-144336 (JP, A) JP-A-8-323818 (JP, A) JP-A-9-76273 (JP, A) 285895 (JP, A) JP-A-8-267496 (JP, A) JP-A-7-186178 (JP, A) JP-A-7-164486 (JP, A) JP-A-7-32423 (JP, A) JP-A-7-16864 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) B29C 45/26 B29C 45/00
Claims (1)
状態の樹脂材料内に加圧ガスを注入し、ガス圧により樹
脂材料を金型内面に向かって押しつけつつ薄肉化し、キ
ャビティ内を流動する樹脂の先端部に可動式コアを配
し、該可動式コアを定荷重発生装置に連結した中空品成
形金型において、可動式コアを大断面積の第一段可動コ
アと小断面積の第二段可動コアの２段構成とし、第二段
可動コアを第一段可動コアと同一方向に移動可能に第一
段可動コア内にを配したことを特徴とする中空品成形金
型。1. A pressurized gas is injected into a molten and flowable resin material introduced into a cavity in a mold, and the resin material is thinned while being pressed against an inner surface of the mold by gas pressure, and flows in the cavity. A movable core is disposed at the tip of the resin, and the movable core is connected to a constant load generating device. A hollow article molding die having a two-stage movable core configuration, wherein a second-stage movable core is disposed in the first-stage movable core so as to be movable in the same direction as the first-stage movable core.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18042096A JP2974615B2 (en) | 1996-07-10 | 1996-07-10 | Hollow mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18042096A JP2974615B2 (en) | 1996-07-10 | 1996-07-10 | Hollow mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1024457A JPH1024457A (en) | 1998-01-27 |
| JP2974615B2 true JP2974615B2 (en) | 1999-11-10 |
Family
ID=16082957
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18042096A Expired - Fee Related JP2974615B2 (en) | 1996-07-10 | 1996-07-10 | Hollow mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2974615B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2902364B2 (en) * | 1996-10-14 | 1999-06-07 | バンドー化学株式会社 | Hollow tubular body for air intake duct, molding die thereof and molding method thereof |
-
1996
- 1996-07-10 JP JP18042096A patent/JP2974615B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1024457A (en) | 1998-01-27 |
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