DE2302458C3

DE2302458C3 - Method and device for producing a welding socket used to connect thermoplastic plastic pipes

Info

Publication number: DE2302458C3
Application number: DE19732302458
Authority: DE
Inventors: Kurt 4100 Duisburg; Wimmershoff Herbert 5602 Langenberg Peitz
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Filing date: 1973-01-16
Publication date: 1976-03-25

Description

Für die Durchführung des Verfahrens wird ein Aufweitedorn verwendet, der aus einem zylindrischen hohlen Kern mit Anschlüssen zum Zu- und Abführen eines Heiz- und eines Kühlmittels, z. B. Dampf bzw. Kaltwasser, und einem von dem Kern abstreifbaren, in mehrereTo carry out the method, an expanding mandrel is used, which consists of a cylindrical hollow Core with connections for supplying and removing a heating and a coolant, e.g. B. steam or cold water, and one strippable from the core, into several

ϊ.ϊ.

Segmfente zerlegbaren Kernmantel besteht. Erfindungsgemäß weist der Kernmantel auf seinem Umfang eine oder mehrere um seine Längsachse schraubenlinienförmig angeordnete, dichu nebeneinanderliegende Nuten zur Aufnahme der Heli.element-Drahtwindung auf.Segmfente is composed of separable kernmantle. According to the invention the core jacket has one or more helical lines around its longitudinal axis on its circumference arranged, dichu side-by-side grooves to accommodate the Heli.element wire winding on.

Gemäß den weiteren Merkmalen der Erfindung ist der Kernmantel zweckmäßigerweise auf einer auf den Dornkern aufschiebbaren Hülse angeordnet. Diese Anordnung empfiehlt sich vor allem dann, wenn ein größerer Vorrat an mit der Heizdrahtwicklung versehenen Kernmänteln geschaffen werden soll, die nacheinander in den die Schweißmuffe bildenden Kunststoffrohrabschnitt eingepreßt werden. Damit diese Hülse leicht von der Oberfläche des Dornkernes entfernt werden kann, sind die Außenflächen in Richtung auf das Dornende und die Innenfläche der den Kernmantel bildenden Segmente in entgegengesetzte/ Richtung konisch ausgebildetAccording to the further features of the invention, the core sheath is expediently on a Mandrel core arranged slide-on sleeve. This arrangement is particularly recommended when a larger Supply of core sheaths provided with the heating wire winding is to be created, one after the other into the plastic pipe section forming the welding socket be pressed in. So that this sleeve can be easily removed from the surface of the mandrel core can, the outer surfaces are in the direction of the mandrel end and the inner surface of the core shell forming Segments in the opposite / conical direction

Zweckmäßigerweise ist die Hülse mit dem Dornkern durch eine Verriegelung lösbar verbunden, z. B. durch einen Bajonettverschluß, durch Splinte od. dgl.Appropriately, the sleeve is releasably connected to the mandrel core by a lock, for. B. by a bayonet lock, by cotter pins or the like.

Die Erfindung sieht weiterhin ein zur Aufnahme des hülsenförmigen Kunststoffrohres dienendes, zwei- oder mehrteiliges Spannfutter, welches zum Durchleiten von Heiz- und Kühlflüssigkeit doppelwandig ausgebi'det und für die Kalibrierung der aufgeweiteten Muffe anstellbar istThe invention also provides a two-way or one that serves to receive the sleeve-shaped plastic pipe multi-part chuck, which is double-walled for the passage of heating and cooling liquid and can be used to calibrate the expanded sleeve

In den Zeichnungen sind Ausführungsbeispiele der Erfindung dargestellt Es zeigtIn the drawings, exemplary embodiments of the invention are shown

A b b. 1 einen Längsschnitt durch eine fertige Kunststoffrohrverbindung, A b b. 1 a longitudinal section through a finished plastic pipe connection,

A b b. 2 einen Längsschnitt durch den Dorn mit der aufgesetzten Heizdrahtwicklung, und zwar vor dem Einführen undA b b. 2 shows a longitudinal section through the mandrel with the heating wire winding attached, namely before Introduce and

A b b. 3 den gleichen Dorn nach dem Einführen in die Muffenhülse,A b b. 3 the same mandrel after inserting it into the socket sleeve,

A b b. 4 einen Dorn mit konischer Wandung.A b b. 4 a mandrel with a conical wall.

Zur Herstellung einer die beiden Rohrenden 11 und 12 miteinander verbindenden Schweißmuffe, welche aus dem Rohrabschnitt 7 und der in dessen Innenwandung eingelagerten Heizelement-Drahtwindungen 5 besteht (Abb. 1), dient der zylindrische hohle Kern 1, der mit dem Einlaß 2 und dem Auslaß 3 für das flüssige Heiz- bzw. Kühlmittel versehen ist. Auf dem Umfang der Hülse 6 des Domes ist der in mehrere Segmente unterteilte Kernmantel 4 angeordnet, der eine schraubenlinienförmig angeordnete Nute zur Aufnahme der Heizelement-Drahtwindungen 5 aufweist.To produce a welding socket connecting the two pipe ends 11 and 12 to one another, which from the pipe section 7 and in its inner wall embedded heating element wire windings 5 (Fig. 1), the cylindrical hollow core 1 is used, which is provided with the inlet 2 and the outlet 3 for the liquid heating or cooling medium. On the perimeter The sleeve 6 of the dome is arranged with the core jacket 4, which is subdivided into several segments and one of which is helical arranged grooves for receiving the heating element wire windings 5.

Der dermaßen vorbereitete Kern wird in den thermoplastischen Rohrabschnitt 7 hineingepreßt, welcher sich in einem zylindrischen, mit einem Zulauf 9 und einem Ablauf 10 für das flüssige Heiz- bzw. Kühlmittel versehenen Spannfutter 8 befindet. Wie in A b b. 3 dargestellt, werden dabei die Heizelement-Drahtwindungen 5 in die Innenwand des Rohrabschnittes 7 hineingepreßt. Nach erfolgtem Abkühlen wird der Kern 1 nach oben hinausgezogen. Anschließend werden die Kernmantelsegmente 4 von der Heizelement-Drahtwindung 5 gelöst und ebenfalls nach oben herausgenommen.The core prepared in this way is placed in the thermoplastic Pipe section 7 pressed in, which is in a cylindrical, with an inlet 9 and a drain 10 for the liquid heating or coolant provided chuck 8 is located. As in A b b. 3 shown, the heating element wire windings 5 are pressed into the inner wall of the pipe section 7. After cooling, the core 1 is pulled out upwards. Then the core shell segments 4 released from the heating element wire winding 5 and also taken out upwards.

Die in Abb.4 dargestellte Vorrichtung weist eine nach unten sich konisch verjüngende Hülse 6 des Kernes auf, auf welcher Kernmantelsegmenie 4 angeordnet sind, die sich in entgegengesetzter Richtung nach oben konisch verjüngen. Diese Anordnung bezweckt ein leichtes Entfernen des Kernes 1.The device shown in Fig.4 has a downwardly tapering sleeve 6 of the core, on which core shell segment 4 is arranged which taper conically upwards in the opposite direction. This arrangement is intended easy removal of the core 1.

Hierzu 2 Blatt ZeichnungenFor this purpose 2 sheets of drawings

Claims

Patent claims:

1. A method for producing a welding socket used to connect thermoplastic plastic pipes, with a mono- or bifilar heating wire winding that can be connected to an electrical power source in a helical arrangement and with a small spacing of the individual windings from each other embedded in the inner wall of a pipe section made of polyethylene, characterized in that first the outer wall of the pipe section is heated to a temperature of about 115 ° C, while the temperature of the inside is kept lower, that the heating wire winding is then brought into contact with the inner wall of the pipe section at the same time as the pipe section is expanded , and that then the inner wall of the pipe section is ^{heated to a temperature of about 180 0} C and thereby the heating wire winding is embedded in the pipe section and then the pipe section is cooled to room temperature while maintaining its inner diameter.

2. The method according to claim 1, characterized in that the heating wire winding on one known expanding mandrel applied, the mandrel pressed axially into the plastic pipe section and heated to a temperature causing the wire winding to melt, whereupon the expanding mandrel is cooled and removed from the finished welding socket after it has cooled down will.

3. Apparatus for performing the method according to claim 1, consisting of a cylindrisehen hollow core with connections for supply and ^ discharge of a heating and a coolant, z. B. Steam or cold water, and one that can be stripped from the core and can be broken down into several segments Jacket, characterized in that the core jacket has one or more around its circumference Longitudinal axis helically arranged closely spaced grooves for receiving the heating element wire coil.

4. Apparatus according to claim 3, characterized in that the core jacket (4) on one on the Mandrel core push-on sleeve (6) is arranged.

5. Device according to claims 3 and 4, characterized in that the outer surface of the Sleeve (6) towards the end of the mandrel and the intial surface that of the segments forming the core jacket (4) is conical in the opposite direction are trained.

6. Device according to claims 3 to 5, characterized in that the sleeve (6) with the Mandrel core by a lock z. B. releasably connected by a bayonet lock or by split pins is.

7. Device according to claims 3 to 6, characterized by a two-part or multi-part chuck (8) serving to receive the sleeve-shaped plastic pipe section, which is double-walled for the passage of heating and cooling liquid and is adjustable for the calibration of the expanded sleeve . (> 5

The invention relates to a method and a device for producing a for connecting thermoplastic Plastic pipes serving welding socket, wherein in the inner wall of a pipe section Made of polyethylene, a mono- or bifilar heating wire winding that can be connected to an electrical power source embedded in a helical arrangement and with a small distance between the individual turns will.

Such welding sleeves are known to be used to put thermoplastic plastic pipes in place their use with each other to simple and from external influences, z. B. wind or rain, largely independent way to firmly join together. This is done by inserting the ends of the joints to be joined Pipes in the welding socket and applying a current to the heating wire winding of the socket, whereby the pipes inserted into the socket and the socket soften on the surfaces exposed to the heating and melting, so that the nested parts firmly together after switching off the power and cooling are welded.

The previously known way of manufacturing such sleeves is the injection molding process, but some economic and manufacturing difficulties, especially for plastic pipes with a larger than 200 mm in diameter. In this process, the wire is wrapped in a Molded with the thermoplastic plastic.

With the DT-OS 20 53 938 it has also become known that one of an extruder slot die Exiting warm band made of thermoplastic material around the one set in rotation Thorn held heating wire winding is wound, whereupon after achieving the desired sleeve wall thickness severed the tape and the sleeve, if necessary, after trimming its front ends from the mandrel is deducted.

The object of the invention is to create a method and a device which make it possible to Manufacture welding sleeves of the type mentioned in particular in larger dimensions.

This object is achieved according to the invention in that first the outer wall of the pipe section is heated to a temperature of about 115 ° C, while the temperature of the inner wall is kept lower, that the heating wire winding is then brought into contact with the inner wall of the pipe section at the same time as the pipe section is expanded and is then heated that the inner wall of the pipe section to a temperature of about 18O ⁰ C and thereby the heating wire coil is embedded in the tube section, and then cooled, the pipe section while maintaining its inside diameter to room temperature.

According to the further feature of the invention, the heating wire winding is based on a known per se Applied expanding mandrel, the mandrel is pressed axially into the plastic pipe section and on a Melting the wire winding causing temperature is heated, whereupon the expanding mandrel is cooled and after the finished welding socket has cooled down, it is removed therefrom.