JPS6235898B2 - - Google Patents

Description

【発明の詳細な説明】 本発明は合成樹脂パイプの一端に受口を成形
し、しかも該受口の内周面にはゴム輪装填用の溝
を形成するようなゴム輪装填型受口の成形方法に
関し、特に内型と外型で形成された空窩内へ軟化
した樹脂パイプを圧入しながら増肉して形成する
とき、内型および外型の成形温度差を設けると共
に外型には冷却手段を備えて受口の外表面に硬化
皮膜が形成されてから外型を開くようにした成形
方法に関するものである。Detailed Description of the Invention The present invention relates to a rubber ring loading type socket in which a socket is molded at one end of a synthetic resin pipe, and a groove for loading a rubber ring is formed on the inner peripheral surface of the socket. Regarding the molding method, especially when forming by increasing the thickness while press-fitting a softened resin pipe into the cavity formed by the inner mold and the outer mold, a molding temperature difference is created between the inner mold and the outer mold, and the outer mold is The present invention relates to a molding method in which a cooling means is provided and the outer mold is opened after a hardened film is formed on the outer surface of the socket.

樹脂パイプに受口を二次成形するには拡径芯型
を用いる押込成形、或は外型のみで成形するブロ
ー成形が利用されるが、成形精度のうえから芯型
を用いる押込成形が奨用される。しかしながら前
記の成形手段では拡径によつて肉厚が薄くなり、
強度的に問題が起こることがあり、増肉しつつ成
形する方法が提案されている。そしてこれらの増
肉成形では一般に内型と外型で形成する成形型を
加温すると共に軟化した樹脂パイプを前記外型と
内型の間に形成される空窩に圧入して成形してい
る。また管受口には、挿込パイプと特定の間隙を
保持して互いに僅かの偏心、屈折が許されるよう
に構成されるものがあり、このような受口には前
記間隙をシールすると共に偏心、屈折量を吸収、
支持するゴム輪が設けられる。そしてこのゴム輪
は受口内に安定して位置保持される必要があるか
ら受口内面にはゴム輪装填用溝が形成される。 For secondary molding of sockets on resin pipes, push molding using an expanded core mold or blow molding using only an outer mold is used, but push molding using a core mold is recommended from the standpoint of molding accuracy. used. However, with the above-mentioned forming means, the wall thickness becomes thinner due to diameter expansion.
Problems may arise in terms of strength, and methods have been proposed in which molding is performed while increasing the thickness. In such thickening molding, a mold formed by an inner mold and an outer mold is generally heated, and a softened resin pipe is press-fitted into a cavity formed between the outer mold and the inner mold. . In addition, some pipe sockets are configured to maintain a specific gap with the insertion pipe and allow slight eccentricity and bending from each other. , absorbs the amount of refraction,
A supporting rubber ring is provided. Since this rubber ring needs to be stably held in position within the socket, a groove for loading the rubber ring is formed on the inner surface of the socket.

ところでこのような溝が形成される受口にあつ
ては受口の管肉が複雑に屈曲し、しかも増肉の要
求される管軸方向長さも長いから、一般の押込成
形温度では樹脂の流動性が不足する。従つて内型
および外型が相当高温に保持されて成形される
が、一方成形の完了した受口は硬化してから取り
出す必要があり、成形型の完全冷却を待つてから
取り出していたのでは極めて長い成形サイクルと
なつて生産効率を低下させる。 By the way, in the case of a socket in which such a groove is formed, the pipe wall of the socket is complicatedly bent, and the length in the axial direction of the pipe that requires thickening is long, so the flow of the resin is slowed down at the normal extrusion molding temperature. There is a lack of sex. Therefore, the inner and outer molds are held at a fairly high temperature during molding, but the molded socket must be hardened before being taken out, and the mold must have cooled completely before being taken out. This results in an extremely long molding cycle and reduces production efficiency.

本発明はこれらに着目してなされたもので、前
記したような受口の成形において、外型に冷却手
段を備えると共に、その成形温度を内型より外型
を高温にして押込成形し、押込成形後は先ず外型
を冷却して、受口の外表面に硬化皮膜を形成した
後外型を開き、次いで内型上の受口を強制冷却し
て受口を取り出すようにしたもので成形サイクル
を短縮すると共に確実な成形を効率よく行なうよ
うにしたものである。 The present invention has been made with attention to these points, and in the molding of the socket as described above, the outer mold is equipped with a cooling means, and the molding temperature is set to a higher temperature for the outer mold than the inner mold, and the molding is performed by pressing. After molding, the outer mold is first cooled to form a hardened film on the outer surface of the socket, then the outer mold is opened, and then the socket on the inner mold is forcedly cooled to take out the socket. This shortens the cycle and ensures efficient molding.

以下本発明を図面に基づいて更に詳細に説明す
る。第１図は本発明を利用するに好適な受口およ
び継手の説明図であつて一部を中断して示した側
面図である。１は受口パイプでその一端に前記し
たような受口２が形成される。３は挿込パイプで
その一端が受口２内に挿入され、受口２内には段
付ゴム輪溝４が形成され、該溝４にゴム輪５が配
設される。そしてゴム輪５の頂部には係合山部を
形成し、該山部は溝４の段凹部に嵌装されてゴム
輪５が安定保持される。そしてこのような受口の
成形には例えば第２図で示すような成形型が利用
される。即ち本成形型は７で示す内型と、８で示
す外型で構成され、内型７にはアンダーカツトと
なるゴム輪装填段付溝４の成形部材１２が設けら
れ、該成形部材１２は芯型部材から突出および退
入するように構成される。そしてこれらの成形部
材１２は従来知られたものが利用できるが図は成
形部材１２が多数のスライド片で構成され、かつ
該スライド片１２は互いに隣設するスライド片と
経時的に縮径変位するグループで構成されて、縮
径グループで形成される空間に他のグループが縮
径してスライド片１２が芯型面より没入するもの
を例示した。１１は芯型を形成する固定片、９は
芯、１０は案内片で、前記スライド片１２は摺動
部材１３の矢印方向移動によつて前記したように
突出若しくは没入するように構成される。８，
８′は外型で該外型は２つ割型で構成すると共に
そのそれぞれの内部に冷媒通路１５を形成する。
図は該通路１５が角形のものを示したが自由な断
面形状にできる。またこれらの冷媒通路１５は一
方の割型内でジグザグ状の単路で形成されて冷媒
が循環するように構成される。１６は冷媒導入口
を示した。このように構成された成形型は第２図
に示すように内型７のスライド片１２が突出して
受口の内面を規制し、外型８，８′が内型７を取
り囲んで空窩部１４が形成される。そして該空窩
部１４はパイプ１の肉厚と同等若しくはそれより
厚肉の間隙を形成する。このように構成した成形
型は加熱され、第２図に示すように軟化パイプ１
が圧入され押込リング１８が矢印方向に押圧され
ると増肉成形が完了する。ところが前記したよう
にこのような屈曲の多い受口は成形温度が高く設
定されるので冷却に長時間を要し、例えば従来の
ように押込成形終了後比較的早い時期に外型８，
８′を開型すると、第４図に示すように受口２の
外周面の硬化が充分でなく肉が瘠せて2″となつた
り、或は屈折変形歪が生じる。これらから本発明
では第３図の略図で示すように、内型７と外型８
の間に成形温度差を設けて、外型温度を内型７よ
り高温に保持するように構成するものである。従
つて押し込まれる樹脂パイプ１は外型の温度が高
いので拡径側に押し拡げられて、平行若しくは縮
径方向に指向しながら進むとき、内型７側より高
い温度に接するので成形を円滑にすると共に確実
に成形される。また押し込み圧も少なくてすむ。
そしてその温度差は成形樹脂によつて異なるが塩
化ビニル樹脂では第３図に示すように外型８を内
型７より約02％高く加熱する。次いで第５図に示
すように外型８に設けた冷却装置を作用させて
（例えば冷媒を通過させて）外型を冷却する。こ
れによつて受口２は外周側から硬化が進み、外周
面側に硬化皮膜が形成された状態になるから前述
の様な不都合は回避される。即ち、外型８の温度
が内型７の温度のほぼ50〜60％低くなつた時点
（例えば前記例で図示した40〜70℃）で外表面上
への硬化皮膜形成が達成されるので、その後８，
８′を開型して退避し、次いで第６図に示すよう
に内型７にかぶされたままの受口２に強制冷却を
施す。そしてこの冷却には適当な手段が利用でき
るが、例えば図示したように水１７を流下若しく
は噴出して強制冷却する。このようにして２次冷
却が終つた時点で、第２図で例示したスライド片
１２が芯型より没入し、受口パイプ１は内型７か
ら引き抜かれる。そして引き抜かれた受口には再
び空気、水等によつて３次冷却されるが、これら
は単なる放冷でもよい。 The present invention will be explained in more detail below based on the drawings. FIG. 1 is an explanatory diagram of a socket and a joint suitable for utilizing the present invention, and is a partially interrupted side view. Reference numeral 1 denotes a socket pipe, at one end of which a socket 2 as described above is formed. Reference numeral 3 denotes an insertion pipe, one end of which is inserted into the socket 2. A stepped rubber ring groove 4 is formed in the socket 2, and a rubber ring 5 is disposed in the groove 4. An engaging ridge is formed at the top of the rubber ring 5, and the ridge is fitted into the stepped recess of the groove 4, thereby stably holding the rubber ring 5. For molding such a socket, a mold as shown in FIG. 2, for example, is used. That is, the present molding die is composed of an inner die indicated by 7 and an outer die indicated by 8, and the inner die 7 is provided with a forming member 12 having a rubber ring loading stepped groove 4 serving as an undercut. It is configured to protrude and retract from the core member. Although conventionally known molding members 12 can be used as these molding members 12, the molding member 12 shown in the figure is composed of a large number of slide pieces, and the slide pieces 12 are displaced in diameter with time with respect to adjacent slide pieces. An example is shown in which the slide piece 12 is made up of groups, and the diameter of the other group is reduced in the space formed by the reduced diameter group, so that the slide piece 12 is inserted into the space formed by the reduced diameter group. 11 is a fixed piece forming a core shape, 9 is a core, 10 is a guide piece, and the slide piece 12 is configured to protrude or retract as described above by moving the sliding member 13 in the direction of the arrow. 8,
Reference numeral 8' denotes an outer mold, which is composed of two split molds, each of which has a refrigerant passage 15 formed therein.
Although the figure shows the passage 15 having a rectangular shape, it can have any cross-sectional shape. Further, these refrigerant passages 15 are formed in a zigzag-like single path within one of the split molds, so that the refrigerant circulates. 16 indicates a refrigerant inlet. As shown in FIG. 2, in the mold configured in this way, the slide piece 12 of the inner mold 7 protrudes to regulate the inner surface of the socket, and the outer molds 8 and 8' surround the inner mold 7 to fill the cavity. 14 is formed. The cavity 14 forms a gap with a wall thickness equal to or thicker than that of the pipe 1. The mold configured in this way is heated, and the softened pipe 1 is formed as shown in FIG.
is press-fitted and the push-in ring 18 is pressed in the direction of the arrow, completing the thickening molding. However, as mentioned above, the molding temperature is set high for such a socket with many bends, so it takes a long time to cool down.
When the mold 8' is opened, as shown in FIG. As shown schematically in Figure 3, an inner mold 7 and an outer mold 8
A molding temperature difference is provided between the inner mold 7 and the outer mold 7 so that the outer mold temperature is maintained at a higher temperature than the inner mold 7. Therefore, since the temperature of the outer mold is high, the resin pipe 1 that is pushed in is forced to expand in the diameter-expanding side, and when it advances parallel or oriented in the diameter-reducing direction, it comes into contact with a higher temperature than the inner mold 7 side, so that the molding can be performed smoothly. At the same time, it is molded reliably. Further, the pushing pressure can be reduced.
The temperature difference varies depending on the molding resin, but in the case of vinyl chloride resin, the outer mold 8 is heated approximately 2% higher than the inner mold 7, as shown in FIG. Next, as shown in FIG. 5, a cooling device provided on the outer mold 8 is operated (for example, by passing a refrigerant) to cool the outer mold. As a result, the socket 2 is cured from the outer circumferential side, and a hardened film is formed on the outer circumferential surface, thereby avoiding the above-mentioned inconvenience. That is, the formation of a cured film on the outer surface is achieved when the temperature of the outer mold 8 becomes approximately 50 to 60% lower than the temperature of the inner mold 7 (for example, 40 to 70° C. as shown in the above example). After that 8,
The mold 8' is opened and evacuated, and then, as shown in FIG. 6, the socket 2 covered with the inner mold 7 is forcedly cooled. Appropriate means can be used for this cooling; for example, as shown in the figure, water 17 is forcedly cooled by flowing down or jetting out. When the secondary cooling is completed in this way, the slide piece 12 illustrated in FIG. 2 is recessed from the core mold, and the socket pipe 1 is pulled out from the inner mold 7. The socket from which it has been pulled out is then tertiary cooled again with air, water, etc., but these may simply be left to cool.

本発明ゴム輪装填型受口の成形方法は以上のよ
うに行なうから、曲面の多い受口部成形型に一致
させて行なうことができ、しかも成形外観を綺麗
に成形することができる。また外型冷却に続いて
内型と受口を同時に強制冷却するので成形サイク
ルを短縮し、生産効率を向上することができた。 Since the method for molding the rubber ring-loaded socket of the present invention is carried out as described above, it can be carried out in accordance with the mold for the socket part having many curved surfaces, and the molded appearance can be formed neatly. In addition, after cooling the outer mold, the inner mold and socket are simultaneously forcedly cooled, which shortens the molding cycle and improves production efficiency.

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

第１図はゴム輪装填受口と継手の構成を例示し
た側面図でその一部は中断して示す。第２図は本
発明を実施した成形金型の一例を示した一部断面
側面図、第３図は成形条件を示した説明略図、第
４図は従来成形の欠点説明図、第５図は本発明の
過程を示した説明略図、第６図は強制冷却を示し
た説明図である。 １……受口パイプ、２……受口、３……挿込パ
イプ、４……ゴム輪段付溝、５……ゴム輪、６…
…成形型、７……内型、８……外型、９……芯、
１０……案内片、１１……固定部、１２……スラ
イド片、１３……摺動部材、１４……空窩部、１
５……冷媒通路、１６……導入口、１７……水。 FIG. 1 is a side view illustrating the structure of a rubber ring loading socket and a joint, with a portion thereof being cut off. Fig. 2 is a partially sectional side view showing an example of a molding die embodying the present invention, Fig. 3 is an explanatory diagram showing molding conditions, Fig. 4 is an explanatory diagram of defects in conventional molding, and Fig. 5 is An explanatory diagram showing the process of the present invention, FIG. 6 is an explanatory diagram showing forced cooling. 1... Socket pipe, 2... Socket, 3... Insertion pipe, 4... Rubber ring stepped groove, 5... Rubber ring, 6...
...molding mold, 7...inner mold, 8...outer mold, 9...core,
10... Guide piece, 11... Fixed part, 12... Slide piece, 13... Sliding member, 14... Hollow part, 1
5...Refrigerant passage, 16...Inlet, 17...Water.

Claims (1)

【特許請求の範囲】[Claims] １ 内型および外型で構成された空窩内へ軟化し
た樹脂パイプの一端を圧入してゴム輪装填用溝を
その内面に形成しつつ増肉成形する受口成形方法
であつて、該押込成形型の成形温度を内型より外
型を高温度にし、かつ該外型には冷却手段を備え
て、押込成形後先ず外型を冷却し、受口の外表面
上に硬化皮膜を形成した後外型を開型退避させ、
次いで内型上の成形受口外側から冷却水等による
強制冷却を行なうことを特徴とするゴム輪装填型
受口の成形方法。1. A socket molding method in which one end of a softened resin pipe is press-fitted into a cavity composed of an inner mold and an outer mold, and a groove for inserting a rubber ring is formed on the inner surface of the pipe while the thickness is increased. The molding temperature of the outer mold was set higher than that of the inner mold, and the outer mold was equipped with a cooling means to first cool the outer mold after push molding and form a hardened film on the outer surface of the socket. The rear outer mold is opened and retracted,
A method for molding a rubber ring-loaded socket, characterized in that the molding socket is then forcedly cooled with cooling water or the like from the outside of the molding socket on the inner mold.