JPH04173123A - Blow-forming method of resin pipe - Google Patents
Blow-forming method of resin pipeInfo
- Publication number
- JPH04173123A JPH04173123A JP2298398A JP29839890A JPH04173123A JP H04173123 A JPH04173123 A JP H04173123A JP 2298398 A JP2298398 A JP 2298398A JP 29839890 A JP29839890 A JP 29839890A JP H04173123 A JPH04173123 A JP H04173123A
- Authority
- JP
- Japan
- Prior art keywords
- parison
- core
- inner diameter
- resin pipe
- 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.)
- Granted
Links
- 229920005989 resin Polymers 0.000 title claims abstract description 29
- 239000011347 resin Substances 0.000 title claims abstract description 29
- 238000000034 method Methods 0.000 title claims abstract description 17
- 238000000071 blow moulding Methods 0.000 title claims description 29
- 238000007664 blowing Methods 0.000 claims abstract description 12
- 230000001105 regulatory effect Effects 0.000 claims description 10
- 238000000465 moulding Methods 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 5
- 238000007493 shaping process Methods 0.000 claims 1
- 230000000694 effects Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin 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
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/08—Biaxial stretching during blow-moulding
- B29C49/16—Biaxial stretching during blow-moulding using pressure difference for pre-stretching, e.g. pre-blowing
-
- 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
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
-
- 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
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
- B29C2049/4807—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity by movable mould parts in the mould halves
-
- 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
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
- B29C49/04—Extrusion blow-moulding
-
- 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
- B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
- B29C49/42—Component parts, details or accessories; Auxiliary operations
- B29C49/48—Moulds
- B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
- B29C49/4812—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity and welding opposite wall parts of the parisons or preforms to each other
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- B29L2031/00—Other particular articles
- B29L2031/703—Bellows
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Moulds For Moulding Plastics Or The Like (AREA)
- Blow-Moulding Or Thermoforming 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、熱可塑性樹脂製のパリソンがらブロー成形法
により所定形状の樹脂パイプを成形する方法に関し、特
に端部における内径寸法精度を向１−させた樹脂パイプ
のブロー成形方法に関する。Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method of molding a resin pipe of a predetermined shape by blow molding a parison made of thermoplastic resin, and in particular, a method of molding a resin pipe of a predetermined shape by blow molding a thermoplastic resin parison. -Regarding a blow molding method for a resin pipe.
（従来の技術）
近年、ブロー成形法により成形した中空合成樹脂製品の
両端袋状部を切断してダクト笠と１゜て使用する樹脂パ
イプを成形することが成用されている。(Prior Art) In recent years, it has become common practice to cut the bag-like portions at both ends of a hollow synthetic resin product molded by blow molding to form a resin pipe that is used as a duct shade.
ところで、樹脂パイプは一般に他物に接続して使用する
関係１−１特定の用途においては、樹脂パイプの接続端
部における内径寸法の精度が厳格に要求され、内径寸法
を均一な高精度のものにしなければならなかった。By the way, resin pipes are generally used by connecting them to other objects. 1-1 In certain applications, the accuracy of the inner diameter dimension at the connecting end of the resin pipe is strictly required, and the inner diameter dimension must be uniform and highly accurate. I had to.
しかしながら、元来、ブロー成形方法は中空成形品の内
面形状を規制することができないものであり、市むを得
ず次のような方法を採用して内径寸法を規制するように
努めていた。However, originally, the blow molding method was unable to control the inner shape of the hollow molded product, and the following method was inevitably adopted in an effort to control the inner diameter dimension.
即ち、第１の方法は、パリソンコントローラを用いるも
ので、押出機のノズル七マンドレルの間から押出される
パリソンの肉厚を部分的に変化させ、試行錯誤により比
較的精度の高い内径寸法が得られたパリソンの肉厚を選
択調整してブロー成形を行うものである。That is, the first method uses a parison controller, which partially changes the wall thickness of the parison extruded from between the seven mandrels of the extruder nozzle, and through trial and error, obtains a relatively accurate inner diameter dimension. Blow molding is performed by selectively adjusting the wall thickness of the parison.
第２の方法は、パリソンの端部を袋状とせず開口させて
おき、このパリソンの端部内にパリソンより小径の内径
規制棒を挿入した状態で型締めし、金型と内径規制棒と
の間でパリソン端部を挾持して肉厚を制御し、パイプ端
部における内径寸法の均一化を図ろうとするものである
（例えば、特開平２−９２６１５号公報参照）。The second method is to leave the end of the parison open instead of bag-shaped, and then clamp the mold with an inner diameter regulating rod smaller in diameter than the parison inserted into the end of the parison, thereby connecting the mold and the inner diameter regulating rod. The purpose is to control the wall thickness by holding the parison end between the tubes and to make the inner diameter dimension uniform at the pipe end (see, for example, Japanese Patent Laid-Open No. 2-92615).
（発明が解決１．ようとする課題）
しかしながら、ト記第１の方法においては、パリソンの
ドローダウン、パリソンの射出速度の変化、材料ロット
の相違等の影響を受け、内径寸法を常に一定にすること
が困難なほか、金型が上下の割合型からなり、下型の溝
にパリソンを収納した後、型締めして圧縮空気を吹込む
方式のブロー成形方法の場合には、下型の溝に接触した
パリソンの部分において収納後すくに冷却同化が進行し
、その部分の肉厚が厚くなってしまい、内径寸法の規制
を実現できない問題点があった。(Problem to be solved by the invention 1.) However, in the first method, the inner diameter is always kept constant due to the influence of parison drawdown, changes in parison injection speed, differences in material lots, etc. In addition, in the case of a blow molding method in which the mold consists of an upper and lower mold, and the parison is stored in a groove in the lower mold, the mold is clamped and compressed air is blown into the lower mold. Cooling and assimilation proceeded quickly after storage in the portion of the parison that came into contact with the groove, and the wall thickness in that portion became thicker, posing the problem that it was not possible to regulate the inner diameter dimension.
また、上記第２の方法においては、パリソン内径より大
径の内径規制棒が使用不可能であるため、内径寸法を規
制できる樹脂パイプの内径サイズは著しく制限されるほ
か、押し出したパリソンの下端をパリソンピンチで挟ん
でプリブローをかけることができないので、複雑な形状
の中空成形品において成形後の製品の肉厚コントロール
が難しい欠点あり、さらに、前述したＬ型と下型とで構
成される割金型を使用し、下型の溝にパリソンを収納す
る方式のブロー成形方法においては、ｉ記内径規制棒は
当然使用できず、しかもプリブローを行ってパリソンを
保形することもてきないため、１−０記第２の方法を採
用できる余地がないものであった。In addition, in the second method described above, since it is impossible to use an inner diameter regulating rod with a diameter larger than the inner diameter of the parison, the inner diameter size of the resin pipe that can regulate the inner diameter dimension is significantly limited, and the lower end of the extruded parison is Since pre-blowing cannot be performed by pinching the parison, it is difficult to control the wall thickness of the molded product in complex-shaped hollow molded products. In the blow molding method that uses a mold and stores the parison in the groove of the lower mold, the inner diameter regulating rod listed in i cannot be used, and furthermore, it is not possible to perform pre-blowing to maintain the shape of the parison. - There was no room for adopting the second method.
（課題を解決するための手段）
本発明は、ト述した問題点を解決することを課題とし、
一対の割合型が左右の金型で構成されるブロー成形方法
（縦型ブロー成形方法）と一対の割金型が上下の金型で
構成されるブロー成形方法（横型ブロー成形方法）とを
問わず採用でき、さらに、樹脂°パイプの端部内径をパ
リソンの内径より大径に賦形する場合であっても、その
端部内径の寸法を規制できるブロー成形刃ｄξを提供す
ることを目的としている。(Means for Solving the Problems) An object of the present invention is to solve the above-mentioned problems,
A blow molding method (vertical blow molding method) in which a pair of proportion molds consists of left and right molds and a blow molding method (horizontal blow molding method) in which a pair of split molds consist of upper and lower molds The purpose of the present invention is to provide a blow molding blade dξ that can be adopted without any problem, and that can also regulate the size of the inner diameter of the end even when the inner diameter of the end of the resin pipe is shaped to be larger than the inner diameter of the parison. There is.
本発明は、上記課題を解決するため、少なくとも一端部
における内径寸法が規制された樹脂パイプをブロー成形
する方法として、
一対の割金型間にパリソンを配置して型締めする工程、
Ｆ記パリソンの内部に圧縮空気を吹込んでこのパリソン
を膨ませると同時にこのパリソンの少なくとも一端部側
から中子を上記割合型間に形成された間隙に圧入するこ
とにより、上記中子により上記パリソンの袋部を押圧し
つつこの袋部をパリソンの内部に向って所定位置まで折
返し、上記割金型とＦ記中子との間で所定形状の中空成
形品を賦形する工程、
上記中空成形品を冷却した後、上記割合型を型開きして
取出した中空成形品の内部に形成されたＦ記袋部からな
る中壁を除去する工程、とで構成することを手段とする
ものである。In order to solve the above-mentioned problems, the present invention provides a method for blow molding a resin pipe in which the inner diameter dimension at least at one end is regulated, and includes a step of placing a parison between a pair of split molds and clamping the mold. By blowing compressed air into the inside of the parison to inflate the parison, and at the same time press-fitting a core from at least one end side of the parison into the gap formed between the ratio molds, the bag portion of the parison is expanded by the core. a step of folding the bag portion toward the inside of the parison to a predetermined position while pressing and forming a hollow molded product of a predetermined shape between the split mold and the core F; cooling the hollow molded product; After that, the proportioning mold is opened and the hollow molded product is taken out.
また、上記のブロー成形方法において、割合型間に配置
されたパリソンの内径より大径の中子を上記パリソンを
膨張させながら圧入すること、さらには、パリソン内部
に吹込んだ圧縮空気の一部を中子に穿設したガス抜き孔
を通して、外部に排出しながら中子の圧入及び中空成形
品の賦形を行うことを手段とするものである。Further, in the above blow molding method, a core having a diameter larger than the inner diameter of the parison placed between the proportion molds is press-fitted while expanding the parison, and further, a part of the compressed air blown into the inside of the parison is The method is to press-fit the core and shape the hollow molded product while discharging the gas to the outside through a gas vent hole bored in the core.
（作 用）
本発明にあっては、一対の割金型間へのパリソンの配置
、割金型の型締めの後、パリソン内部に圧縮空気を吹き
込みパリソンが膨張して割金型に押しつけられる瞬間に
、パリソンの端部から所望の樹脂パイプの端部内径寸法
に合致した径の中子を圧入するようにしたので、端部内
径寸法を均一化した樹脂パイプを前述した縦型ブロー成
形方法はもちろんのこと横型ブロー成形方法によっても
成形できるほか、配置されたパリソンの内径より大径の
中子を圧入することが可能となる。(Function) In the present invention, after placing the parison between a pair of split molds and clamping the split molds, compressed air is blown into the parison to expand the parison and press it against the split molds. Since a core with a diameter that matches the inner diameter of the end of the desired resin pipe is instantly press-fitted from the end of the parison, the vertical blow molding method described above can produce a resin pipe with a uniform inner diameter of the end. Of course, it can also be molded by a horizontal blow molding method, and it is also possible to press-fit a core with a larger diameter than the inner diameter of the arranged parison.
また、中子の圧入に際してパリソン内の圧縮空気の一部
を外部に排出するようにした場合には、中子が圧縮空気
の圧力に負けて後退することなく、中子を円滑に前述さ
せることができ、樹脂パイプのブロー成形を容易に行う
ことができる。In addition, when a part of the compressed air inside the parison is discharged to the outside when press-fitting the core, it is possible to smoothly move the core forward without the core retreating due to the pressure of the compressed air. This allows easy blow molding of resin pipes.
（実 施 例） 以下、本発明の実施例を図面に基づいて説明する。(Example) Embodiments of the present invention will be described below based on the drawings.
第１図ｃａｌ〜ｆｇ）は樹脂パイプＰのブロー成形の工
程を示す断面図であり、一対の割金型としてト型ｌと下
型２を用い、まず下型２のキャビテ顕
イに図示しない押手機ヘッドから押し出されたパリソン
３を収納する（（ａ）図）。このパリソン３は両端部を
パリソンピンチで挟んで袋部３ａにされており、その内
部にプリブローにより注入したエアーにより形状が保持
されている。次いで、下型２にト、型１を市ね合わせて
型締めを行う（（ｂ）図）。このとき、計上型間の一側
縁は密閉されず開放されており、計上型間には間隙４が
形成されている。次に、一方の１−下型間がらエアーシ
リンダーに連結されたエアー吹込みノズル５をパリソン
３に打ち込み圧縮空気をγ＋大してパリソン３の膨張を
開始させる（（Ｃ）図）。Fig. 1 (cal to fg) is a cross-sectional view showing the process of blow molding a resin pipe P, in which a pair of split molds are used as a pair of molds 1 and a lower mold 2, and the cavity of the lower mold 2 is exposed first. The parison 3 pushed out from the pusher head is stored (Figure (a)). This parison 3 is formed into a bag portion 3a by pinching both ends of the bag portion 3a, and its shape is maintained by air injected into the bag portion 3a by pre-blowing. Next, the mold 1 is placed on the lower mold 2 and the molds are clamped (see figure (b)). At this time, one side edge between the counting molds is not sealed and is open, and a gap 4 is formed between the counting molds. Next, an air blowing nozzle 5 connected to an air cylinder between one of the lower molds is injected into the parison 3, and the compressed air is increased by γ+ to start the expansion of the parison 3 (Figure (C)).
と同時に、開放されているｌ−下型間の間隙４に外部か
らエアーシリンダーにより中子６を圧入して、所定位置
まで１−下型の内部に前進させる（ｃｄ）図）。At the same time, a core 6 is press-fitted from the outside into the open gap 4 between the lower mold 1 by an air cylinder, and is advanced into the interior of the lower mold 1 to a predetermined position (Figure CD).
この中子６は、成形する樹脂パイプＰの所定の端部内径
寸法に合致させた外径に形成されており、圧縮空気の注
入により膨張しつつあるパリソン先部の袋部３ａを押圧
しながら内部に折り返し、ヒ下型１．２と中子６の外周
面との間でバリンの袋部３ａから外方へ延出するパリソ
ン端部３ｂを挾持している。This core 6 is formed to have an outer diameter that matches the inner diameter of a predetermined end of the resin pipe P to be molded, and is pressed against the bag portion 3a at the tip of the parison, which is being expanded by injection of compressed air. The parison end portion 3b extending outward from the bag portion 3a of the balline is held between the lower die 1.2 and the outer peripheral surface of the core 6 by folding it back inside.
そして、この状態で圧縮空気の注入を継続して行い、Ｌ
下型と中子との間で所定形状の中空成形品を賦形する。Then, in this state, continue to inject compressed air, and
A hollow molded product of a predetermined shape is formed between the lower mold and the core.
続いて、前期（ｄ１図の状態のままＬ下型の冷却を行い
中空成形品を冷却して成形を完了させた後、中子を引き
抜き上下型の型開きを行って中空成形品Ａを取出す（（
ｅ）図）。次いで、この中空成形品の両端部７．８を切
断しく（ｆ）図）、最後にパリソンの袋部から形成され
た中壁９を除去して（（ｇ１図）、中子によりパリソノ
端部３ｂの肉厚が強制的に均一化された結果、端部１ｏ
の内径が規制され寸法が均一化された樹脂パイプＰが得
られることになる。Next, the lower L mold is cooled in the state shown in Figure d1 in the first half, and the hollow molded product is cooled to complete the molding, and then the core is pulled out and the upper and lower molds are opened to take out the hollow molded product A. ((
e) Figure). Next, both ends 7.8 of this hollow molded product are cut off (Figure (f)), and finally the inner wall 9 formed from the bag part of the parison is removed (Figure (g1)), and the ends of the parison are cut with a core. As a result of forcibly making the wall thickness of 3b uniform, the end portion 1o
A resin pipe P whose inner diameter is regulated and whose dimensions are uniform can be obtained.
第２図は、樹脂パイプＰ′を縦型のブロー成形方法によ
り蛇腹状に成形する例を示すもので、その成形工程は第
１図に示すものとほとんど同様である。FIG. 2 shows an example of molding a resin pipe P' into a bellows shape by a vertical blow molding method, and the molding process is almost the same as that shown in FIG.
即ち、左右の一対の金型１１．１２間にパリソン１３を
垂下させる（（ａ）図）。このとき、パリソンの下端部
はパリソンピンチで挟んで袋部１３ａを形成し、その内
部にはプリブローをかけてエアーを注入している。次い
で、左右の金型■】、１２を型締めしてパリソン１３の
１一端部をピンチする（（ｂ）図）。このとき、左右の
金型間の下方は密閉されておらず、間隙１４が形成され
ている。次に、パリソン１３のト端部からエアー吹込み
ノズル１５を打ち込み、パリソン１３内部に圧縮空気を
注入し左右の金型内面の蛇腹形状に沿って膨張を開始さ
せる（（Ｃ）図〕。パリソンが膨張を開始する瞬間にパ
リソン１３の下方から間隙］４内に所定外径の中子１６
を１一方へ向って圧入して、パリソンの袋部１３ａを押
圧しつつト方へ折返しながら所定位置までト昇させる（
（ｄ）図）。That is, the parison 13 is suspended between a pair of left and right molds 11 and 12 (FIG. (a)). At this time, the lower end of the parison is pinched with a parison pinch to form a bag portion 13a, and the inside of the bag portion 13a is pre-blown and air is injected. Next, the left and right molds 1] and 12 are clamped, and one end of the parison 13 is pinched (see figure (b)). At this time, the lower part between the left and right molds is not sealed, and a gap 14 is formed. Next, the air blowing nozzle 15 is driven into the top end of the parison 13, compressed air is injected into the inside of the parison 13, and the expansion starts along the bellows shape of the inner surfaces of the left and right molds (Figure (C)). At the moment when the parison 13 starts to expand, a core 16 of a predetermined outer diameter is inserted into the gap]4 from below the parison 13.
1 towards one side, and while pressing the bag part 13a of the parison, raise it to a predetermined position while folding it towards the side (
(d) Figure).
なお、この中子Ｉ６の外径はパリソン１３の内径より大
径のものである。Note that the outer diameter of this core I6 is larger than the inner diameter of the parison 13.
そして、この状態で圧縮空気の注入を続は所定形状の中
空形成品Ａ′を賦形した後、この中空成形品Ａ′を冷却
して成形を完了する。Then, in this state, compressed air is injected to shape the hollow molded product A' into a predetermined shape, and then the hollow molded product A' is cooled to complete the molding.
次いで、型開きして金型から中空成形品Ａ′を取出しく
（ｅ）図）、その両端部１７．１８を切断しくげ）図）
、パリソン袋部から形成された中壁１９を除去して端部
内径が規制された蛇腹状の樹脂パイプＰ′が得られる。Next, the mold is opened and the hollow molded product A' is taken out from the mold (Fig. e), and its both ends 17 and 18 are cut off (Fig.).
By removing the inner wall 19 formed from the parison bag portion, a bellows-shaped resin pipe P' having a regulated end inner diameter is obtained.
第３図は別の実施例を示す拡大断面図であり、パリソン
２１の端部から圧入する中子２２にガス抜き孔２３を穿
設しておき、中子２２の圧入時にパリソン内部の圧縮空
気をパリソン袋部２１ａの壁を破裂させて矢印のとおり
ガス抜き孔２３を通して外部へ排出するようにしたもの
である。FIG. 3 is an enlarged sectional view showing another embodiment, in which a gas vent hole 23 is provided in the core 22 that is press-fitted from the end of the parison 21, so that when the core 22 is press-fitted, the compressed air inside the parison is removed. The wall of the parison bag portion 21a is ruptured and the gas is discharged to the outside through the gas vent hole 23 as shown by the arrow.
第４図は樹脂パイプの内径規制を両端部において行う実
施例であり、１−型３Ｉと下型３２の間に収納されたパ
リソン３３にその一端部からエアー吹込みノズル３４に
より圧縮空気をγ十人しつつ、パリソン両端部から左右
の中子３５．３６を圧入するようにしたものである。FIG. 4 shows an embodiment in which the inner diameter of the resin pipe is regulated at both ends, and compressed air is injected from one end into the parison 33 housed between the 1-mold 3I and the lower mold 32 by an air blowing nozzle 34. Using ten people, the left and right cores 35 and 36 are press-fitted from both ends of the parison.
この例においては、１下型間の左右の側縁部が開放され
ており、一方の側縁部においてエアーシリンダー３７に
連結したエアー吹込みノズル３４を打ち込むと同時にこ
のエアー吹込みノズル３４の周囲に配置した中子３５を
エアーシリンダー３８により圧入するＬ共に他方の中子
３Ｇも圧入して、パリソン両端部の袋部３３ａ、３３ｂ
を中子３５．３６により押圧して内部に折返し、中子３
５．３６の外径寸法により両端部の内径が規制された樹
脂パイプが成形されるものである。In this example, the left and right side edges between the first lower mold are open, and at the same time when the air blowing nozzle 34 connected to the air cylinder 37 is driven into one side edge, the surroundings of the air blowing nozzle 34 are opened. Press-fit the core 35 placed in L with the air cylinder 38, and press-fit the other core 3G as well to form the bag portions 33a and 33b at both ends of the parison.
is pressed by cores 35 and 36, folded back inside, and core 3
A resin pipe is molded in which the inner diameter of both ends is regulated by the outer diameter dimension of 5.36 mm.
（発明の効果）
本発明においては、パリソンを膨張させると同時にその
端部から中子を圧入するようにしたので、パリソン端部
を金型と中子との間で挾持して強制的に肉厚の制御を行
うことができ、成形条件が種々変化しても、樹脂パイプ
の端部内径を常に中子の外径に合致した所定の寸法に成
形できる。しかも、この樹脂パイプのブロー成形方法と
して、縦型ブロー成形方法と横型ブロー成形方法のいず
れをも採用でき、多様なブロー成形において利用できる
利点がある。(Effects of the Invention) In the present invention, the core is press-fitted from the end of the parison at the same time as the parison is expanded, so the end of the parison is held between the mold and the core and forced to tighten. The thickness can be controlled, and even if the molding conditions vary, the inner diameter of the end of the resin pipe can always be molded to a predetermined size that matches the outer diameter of the core. Moreover, as a blow molding method for this resin pipe, either a vertical blow molding method or a horizontal blow molding method can be adopted, which has the advantage of being usable in a variety of blow moldings.
また、中子としてパリソン内径よりも大きな外径のもの
を使用することにより、パリソン内径より大径の内径寸
法の樹脂パイプであっても、その内径の均一化を実現で
き優れた内径精度を確保できる。In addition, by using a core with an outer diameter larger than the inner diameter of the parison, even if the inner diameter is larger than the inner diameter of the parison, the inner diameter can be made uniform and excellent inner diameter accuracy can be ensured. can.
さらに、中子の圧入の際に圧縮空気の一部を排出するよ
うにした場合には、圧縮空気の圧力に負けることなく中
子をスムーズに突き出すことができ圧入操作がしやすい
ほか、中空成形品の内部に空気を流通させる結果となる
ため、冷却効果が向トし冷却時間を短縮できる利点もあ
る。Furthermore, if a part of the compressed air is discharged when press-fitting the core, the core can be smoothly ejected without losing the pressure of the compressed air, making the press-fitting operation easier. As a result, air is circulated inside the product, which has the advantage of increasing the cooling effect and shortening the cooling time.
図面は本発明の実施例を示し、第１図および第２図はブ
ロー成形方法の１稈を示す概略断面図、第３図は他の実
施例の一部拡大断面図、第４図は別の実施例を説明する
断面図である。
１ 、 ２ 、１１．１２，３１．３２．−−−−一
割金型、３ 、１３．２１．３３． −−−〜− −−
−＝ パリソン、５ 、１５．３４． −−−− エ
アー吹込みノズル、６ 、 １６． ２２． ３５．
３６ −−−−− − 中 子。The drawings show an embodiment of the present invention, FIGS. 1 and 2 are schematic cross-sectional views showing one culm of the blow molding method, FIG. 3 is a partially enlarged sectional view of another embodiment, and FIG. 4 is a separate diagram. It is a sectional view explaining an example. 1, 2, 11.12, 31.32. ------1
Split mold, 3, 13.21.33. −−−〜− −−
-= parison, 5, 15.34. ----- Air blowing nozzle, 6, 16. 22. 35.
36 ------- - Core.
Claims (3)
樹脂パイプを成形する方法であって、 一対の割金型間にパリソンを配置して型締めする工程、 上記パリソンの内部に圧縮空気を吹込んでこのパリソン
を膨ませると同時にこのパリソンの少なくとも一端部側
から中子を上記割金型間に形成された間隙に圧入するこ
とにより、上記中子により上記パリソンの袋部を押圧し
つつこの袋部をパリソンの内部に向って所定位置まで折
返し、上記割金型と上記中子との間で所定形状の中空成
形品を賦形する工程、上記中空成形品を冷却した後、上
記割金型を型開きして取出した中空成形品の内部に形成
された上記袋部からなる中壁を除去する工程、 とからなる樹脂パイプのブロー成形方法。(1) A method for molding a resin pipe with a regulated inner diameter dimension at least at one end, the process comprising placing a parison between a pair of split molds and clamping the mold, and blowing compressed air into the inside of the parison. At the same time as this parison is inflated, a core is press-fitted from at least one end side of the parison into the gap formed between the split molds, so that the bag portion of the parison is pressed by the core and the bag portion is pressed. A step of folding the molded product back toward the inside of the parison to a predetermined position and forming a hollow molded product of a predetermined shape between the split mold and the core. After cooling the hollow molded product, the split mold is A method for blow molding a resin pipe, comprising the steps of: removing an inner wall made of the bag portion formed inside a hollow molded product taken out by opening the mold.
リソンの内径より大径の中子を上記パリソンを膨張させ
ながら圧入するようにした樹脂パイプのブロー成形方法
。(2) A blow molding method for a resin pipe according to claim (1), wherein a core having a diameter larger than the inner diameter of the parison placed between the split molds is press-fitted while expanding the parison.
に吹込んだ圧縮空気の一部を中子に穿設したガス抜き孔
を通して外部に排出しながら中子の圧入及び中空成形品
の賦形を行うようにした樹脂パイプのブロー成形方法。(3) In claim (1) or (2), a part of the compressed air blown into the parison is discharged to the outside through a gas vent hole formed in the core, and the core is press-fitted and the blow-molded product is A blow molding method for resin pipes that involves shaping.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2298398A JPH0675910B2 (en) | 1990-11-02 | 1990-11-02 | Blow molding method for resin pipes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2298398A JPH0675910B2 (en) | 1990-11-02 | 1990-11-02 | Blow molding method for resin pipes |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04173123A true JPH04173123A (en) | 1992-06-19 |
| JPH0675910B2 JPH0675910B2 (en) | 1994-09-28 |
Family
ID=17859189
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2298398A Expired - Fee Related JPH0675910B2 (en) | 1990-11-02 | 1990-11-02 | Blow molding method for resin pipes |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0675910B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1053855A1 (en) * | 1999-05-21 | 2000-11-22 | CRS Srl Centro Ricerche e Sperimentazioni | Apparatus and method for moulding articles of thermoplastic material |
| JP2007245443A (en) * | 2006-03-15 | 2007-09-27 | Opuco:Kk | Blow molding machine and blow molding method |
| JP2016043564A (en) * | 2014-08-22 | 2016-04-04 | 株式会社Fts | Blow molding method |
| EP4292803A3 (en) * | 2019-03-27 | 2023-12-27 | Subaru Corporation | Dust cover, suspension device and dust cover manufacturing method |
-
1990
- 1990-11-02 JP JP2298398A patent/JPH0675910B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1053855A1 (en) * | 1999-05-21 | 2000-11-22 | CRS Srl Centro Ricerche e Sperimentazioni | Apparatus and method for moulding articles of thermoplastic material |
| JP2007245443A (en) * | 2006-03-15 | 2007-09-27 | Opuco:Kk | Blow molding machine and blow molding method |
| JP4698450B2 (en) * | 2006-03-15 | 2011-06-08 | 株式会社オプコ | Blow molding apparatus and blow molding method |
| JP2016043564A (en) * | 2014-08-22 | 2016-04-04 | 株式会社Fts | Blow molding method |
| EP4292803A3 (en) * | 2019-03-27 | 2023-12-27 | Subaru Corporation | Dust cover, suspension device and dust cover manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0675910B2 (en) | 1994-09-28 |
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