WO1979000973A1 - Process and apparatus for joining tube elements of weldable synthetic material - Google Patents

Process and apparatus for joining tube elements of weldable synthetic material Download PDF

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Publication number
WO1979000973A1
WO1979000973A1 PCT/CH1979/000055 CH7900055W WO7900973A1 WO 1979000973 A1 WO1979000973 A1 WO 1979000973A1 CH 7900055 W CH7900055 W CH 7900055W WO 7900973 A1 WO7900973 A1 WO 7900973A1
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WO
WIPO (PCT)
Prior art keywords
welding
value
voltage
circuit
switching stage
Prior art date
Application number
PCT/CH1979/000055
Other languages
German (de)
French (fr)
Inventor
W Sturm
Original Assignee
W Sturm
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Filing date
Publication date
Application filed by W Sturm filed Critical W Sturm
Publication of WO1979000973A1 publication Critical patent/WO1979000973A1/en

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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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
    • B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
    • B29C66/52—Joining tubular articles, bars or profiled elements
    • B29C66/522—Joining tubular articles
    • B29C66/5221—Joining tubular articles for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K11/00—Resistance welding; Severing by resistance heating
    • B23K11/24—Electric supply or control circuits therefor
    • B23K11/25—Monitoring devices
    • 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
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/3404—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint
    • B29C65/342—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint comprising at least a single wire, e.g. in the form of a winding
    • 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
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/3472—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint
    • B29C65/3476—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint being metallic
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
    • B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
    • B29C66/52—Joining tubular articles, bars or profiled elements
    • B29C66/522—Joining tubular articles
    • B29C66/5229—Joining tubular articles involving the use of a socket
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/87—Auxiliary operations or devices
    • B29C66/874—Safety measures or devices
    • B29C66/8748—Safety measures or devices involving the use of warnings
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/912—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux
    • B29C66/9131—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the heat or the thermal flux, i.e. the heat flux
    • B29C66/91311—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the heat or the thermal flux, i.e. the heat flux by measuring the heat generated by Joule heating or induction heating
    • B29C66/91313—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by measuring the temperature, the heat or the thermal flux by measuring the heat or the thermal flux, i.e. the heat flux by measuring the heat generated by Joule heating or induction heating by measuring the voltage, i.e. the electric potential difference or electric tension
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/91—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux
    • B29C66/914—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux
    • B29C66/9161—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the heat or the thermal flux, i.e. the heat flux
    • B29C66/91651—Measuring or controlling the joining process by measuring or controlling the temperature, the heat or the thermal flux by controlling or regulating the temperature, the heat or the thermal flux by controlling or regulating the heat or the thermal flux, i.e. the heat flux by controlling or regulating the heat generated by Joule heating or induction heating
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/96—Measuring or controlling the joining process characterised by the method for implementing the controlling of the joining process
    • B29C66/961—Measuring or controlling the joining process characterised by the method for implementing the controlling of the joining process involving a feedback loop mechanism, e.g. comparison with a desired value
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/94—Measuring or controlling the joining process by measuring or controlling the time
    • 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
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/90—Measuring or controlling the joining process
    • B29C66/94—Measuring or controlling the joining process by measuring or controlling the time
    • B29C66/949—Measuring or controlling the joining process by measuring or controlling the time characterised by specific time values or ranges

Definitions

  • the invention relates to a method for connecting pipeline elements made of weldable plastic by welding their ends by means of electrical resistance heating and a device for carrying out the method.
  • pipeline elements When constructing pipelines from weldable plastic, the methods and devices with which the pipeline elements are connected to one another by electrical resistance heating play a significant role.
  • the term pipeline elements is understood to mean pipes, fittings of all types and fittings which have to be put together to form entire pipelines and piping systems and connected to one another.
  • the execution of the connections for these pipeline elements represents a complex partial operation, which also determines the quality of the pipeline and must therefore be carried out reliably.
  • sleeve connections which form part of the pipe element, or welding sleeves separated from the pipe elements, which are attached to the ends of two pipe elements, are used.
  • OMPI IPO duck plug and are connected to them.
  • a winding made of a resistance heating wire is inserted, which is used for the production .
  • the connection is heated electrically, so that the material of the overlapping ends of the pipeline elements melts in the vicinity of the winding, thereby welding these parts.
  • the heating energy supplied by the winding should be metered in such a way that a perfect connection, ie neither inadequate nor excessive heating of the parts to be connected for metering the heating energy depending on the pipe elements to be connected, a device is used to adjust the heating ⁇ gie done manually or automatically.
  • connection energy supplied for the connection is related to the type of connection and the environmental factors present during the welding, e.g. the ambient temperature or a poor connection, e.g. an interruption in a connector is too small. This usually means that the connection can withstand the stresses mechanically, but is leaky.
  • the invention is therefore based on the object of designing a method of the type described in the introduction in such a way that the greatest possible number of influencing factors is taken into account at least approximately.
  • This object is achieved according to the invention in that the quadratic value of the the same is formed and converted into a pulse frequency corresponding to this value, the pulses being counted by a counter and the welding process being terminated after a setpoint pulse number has been reached. This ensures that the welding energy supplied corresponds very precisely to the setpoint welding energy and that certain environmental influences, for example the outside temperature, the temperature of the sleeve or the like, are also taken into account.
  • a further security with regard to the execution of a welded connection is achieved by a device suitable for carrying out the method according to the invention with a circuit having a switching stage which can be switched off after metering the welding energy in that the switching stage is assigned means for interrupting it when an interruption in the circuit occurs .
  • the invention is shown in the drawing in an exemplary embodiment and described below.
  • the drawing shows a schematic representation of a device for connecting pipe elements made of weldable plastic, which is shown as a block diagram.
  • the device shown in the drawing is intended for the production of connections, especially with welded sockets, but there is in principle no restriction with regard to its use for other types of welded connections, e.g. Socket connections or the like
  • the device shown in the figure is supplied with power via a mains connection 1.
  • the circuit is routed via a switching stage 7.
  • a welding sleeve 3 over a schematically shown.
  • Plug contact 4 connected.
  • a current monitor 6 is arranged at the output of the switching stage 7. This monitors the flowing current and keeps the switching stage, which has a relay, for example, in the working position.
  • a power supply unit 2 is connected to the circuit, by means of which a low voltage, e.g. 12 volts, is generated, which serves to supply the device.
  • the output voltage of the power supply 2 is measured in a transmitter 8 and
  • the output of the transmitter 8 is connected to the input of a pulse generator 9 which generates a pulse frequency corresponding to the square of the voltage.
  • This quadratic value is formed from the charge curve of a capacitor, which is fed directly or indirectly from the voltage at the welding socket via a resistor. If this capacitor is connected to a DC voltage source, the capacitor voltage can only rise up to the level of the supply voltage.
  • the rise in the capacitor voltage is not linear, as is known, but according to the equation
  • Charging voltage and t mean the charging time. If the capacitor is reached when a predetermined charging voltage is reached, e.g. has a comparator, discharges, a new charging process begins and a frequency is obtained which is controlled by the charging voltage or by the mains voltage.
  • a predetermined charging voltage e.g. has a comparator
  • the quadratic function of the mains voltage in the range of, for example, 180-260 V can be simulated by setting the discharge switching point, for example, to a value of 0.39 of the mains voltage at 220 V. If the voltage deviates from this value, the quadratic mains voltage is overcompensated. This overcompensation is necessary for smaller mains voltages in order to counteract the greater heat flow in the plastic material, which occurs due to the longer welding time. This not only increases the welding time according to the lower mains voltage, but also extends it further. This enables a constant welding quality to be achieved, even if the welding time is around the same at a voltage of 180 V, for example. Factor increases. In the same way, by appropriately selecting the partial value of the charging voltage or mains voltage, overcompensation can be achieved at voltages which are above the specified value of the charging voltage or mains voltage.
  • the output of the pulse generator is applied to a counter 10, in which the summation of the pulses takes place.
  • the capacity of counter 10 is e.g. 2 - 2 pulses.
  • a pulse number added up in the counter 10 means a certain heating energy.
  • the number of pulses corresponding to the welding energy is reached in the counter 10. This is ensured by function monitoring 5. If the counter 10 has not yet reached its predetermined number of pulses, e.g. in the event of an interruption in the circuit between the device and the welding sleeve during welding, the functional
  • OMPI Monitoring 5 an interference signal, eg the flashing of a red indicator lamp. As soon as the interference signal sets in, this indicates that the welding of the sleeve 3 must be checked. Simultaneously with the display of the interference signal, the mains voltage is immediately switched off from the welding sleeve 3 by the switching stage 7. The switching on of the circuit by switching on the switching stage 7 is controlled by a switch-on monitor 11. By means of a low voltage, the switch-on monitoring 11 determines whether a welding sleeve 3 or an equivalent resistor is at the circuit output 4. connected. The switch-on monitoring is expediently designed in such a way that the switching on of the current circuit is only possible if the consumer resistance is less than a certain value, for example 3 K ohms.
  • Consequence that the welding power is higher at low ambient temperatures provided, however, that the used electrical resistance heating wire is a PTC thermistor.
  • a form factor taking into account the shape of the welding sleeve can depend on the tension or its quadratic value of the pulse frequency are taken into account. Due to the high counter capacity, it is possible to adhere very precisely to the welding time, which can be in the order of magnitude of, for example, 70-80 lake, and to reliably record times of at least 20 minutes.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)

Abstract

Tube elements, i.e. pipes, shaped pieces and armatures of weldable synthetic material, are interconnected by electric welding. The welding operation is made possible by means of a welding sleeve (3) which is connected to the output (4) of the apparatus. A monitoring device (11) allows the engagement of a stage (7) of the welding circuit. The heating power is determined by a quadratic mean of the welding voltage of the network voltage respectively, in a pulse generator (9) which generates a pulse frequency depending upon this value. The generator pulses are added in a counter (10) and when the counted value corresponds to the heating energy, the stage (7) of the circuit is disengaged. If this value is not reached, a monitoring device (5) produces a failure signal.

Description

Verfahren und Gerät zum Verbinden von Rohrleitungselementen aus schweissbare KunststoffMethod and device for connecting pipe elements made of weldable plastic
Die Erfindung betrifft ein Verfahren zum Verbinden von Rohrleitungselementen aus schweissbarem Kunststoff durch Verschweissen ihrer Enden durch elektrische Widerstands¬ heizung und ein Gerät zur Durchführung des Verfahrens.The invention relates to a method for connecting pipeline elements made of weldable plastic by welding their ends by means of electrical resistance heating and a device for carrying out the method.
Beim Bau von Rohrleitungen aus schweissbarem Kunststoff spielen die Verfahren und Geräte mit denen die Rohrleitungs¬ elemente durch elektrische Widerstandsheizung miteinander verbunden werden, eine erhebliche Rolle. Unter dem Begriff Rohrleitungselemente werden Rohre, Formstücke aller Art und Armaturen verstanden, die zu ganzen Rohrleitungen und Rohrleitungssystemen zusammengesetzt und miteinander ver¬ bunden werden müssen. Die Ausführung der Verbindungen für diese Rohrleitungselemente stellt eine aufwendige Teil¬ operation dar, die zudem die Qualität der Rohrleitung be¬ stimmt und deshalb zuverlässig ausgeführt werden muss. Zum Verbinden der Rohrelemente werden entweder Muffenver¬ bindungen, die einen Teil des Rohrleitungselements dar¬ stellen oder von den Rohrleitungselementen getrennte Schweissmuffen, die auf die Enden zweier Rohrleitungsele-When constructing pipelines from weldable plastic, the methods and devices with which the pipeline elements are connected to one another by electrical resistance heating play a significant role. The term pipeline elements is understood to mean pipes, fittings of all types and fittings which have to be put together to form entire pipelines and piping systems and connected to one another. The execution of the connections for these pipeline elements represents a complex partial operation, which also determines the quality of the pipeline and must therefore be carried out reliably. To connect the pipe elements, either sleeve connections, which form part of the pipe element, or welding sleeves separated from the pipe elements, which are attached to the ends of two pipe elements, are used.
OMPI IPO ente gesteck und mit diesen verbunden werden, verwendet. Im Ueberlappungsbereich dieser Verbindungen ist eine Wicklung aus einem Widerstandsheizdraht eingelegt, der zur Herstellung. der Verbindung elektrisch erhitzt wird, so dass in der Umgebung der Wicklung das Material der sich überlappenden Enden der Rohrleitungselemente schmilzt und dadurch eine Verschweissung dieser Teile erreicht wird. Die durch die Wicklung zugeführte Heizenergie soll hierbei derart dosiert sein, dass eine einwandfreie Verbindung, d.h. weder eine ungenügende noch übermässige Erwärmung der zu verbindenden Teile zur Dosierung der Heizenergie in Abhängigkeit mit der zu verbindenden Rohrelemente wird ein Gerät verwendet, an dem die Einstellung der Heizener¬ gie manuell oder selbsttätig erfolgt.OMPI IPO duck plug and are connected to them. In the overlap area of these connections, a winding made of a resistance heating wire is inserted, which is used for the production . the connection is heated electrically, so that the material of the overlapping ends of the pipeline elements melts in the vicinity of the winding, thereby welding these parts. The heating energy supplied by the winding should be metered in such a way that a perfect connection, ie neither inadequate nor excessive heating of the parts to be connected for metering the heating energy depending on the pipe elements to be connected, a device is used to adjust the heating ¬ gie done manually or automatically.
Beim Schweissen der erwähnten Verbindungen mit einem sol¬ chen Gerät ist es, insbesondere im Hinblick darauf, dass die Verbindungen an einer Baustelle vorgenommen werden müssen, nicht zu vermeiden, dass gelegentlich Verbindungen nicht einwandfrei geschweisst werden. Meistens ist hierbei die für die Verbindung zugeleitete Schweissenergie im Hin¬ blick auf die Art der Verbindung und die während der Schweissung vorliegenden Umgebungsfaktoren, z.B. die Um¬ gebungstemperatur oder eine mangelhafte Verbindung, z.B. ein Unterbruch an einer Steckverbindung zu klein. Dies führt meistens dazu, dass zwar die Verbindung mechanisch den Beanspruchungen standhält, aber undicht ist.When welding the connections mentioned with such a device, in particular with regard to the fact that the connections have to be made at a construction site, it cannot be avoided that connections are occasionally not welded properly. Most of the time, the welding energy supplied for the connection is related to the type of connection and the environmental factors present during the welding, e.g. the ambient temperature or a poor connection, e.g. an interruption in a connector is too small. This usually means that the connection can withstand the stresses mechanically, but is leaky.
Der Erfindung liegt deshalb die Aufgabe zugrunde, ein Ver¬ fahren der eingangs beschriebenen Art so auszugestalten, dass eine möglichst grosse Zahl von Einflussfaktoren min¬ destens näherungsweise berücksichtigt wird. Diese Aufgabe wird ge äss der Erfindung dadurch gelöst, dass aus der Messung der Schweissspannung der quadratische Wert der- selben gebildet und in eine diesem Wert entsprechende Im¬ pulsfrequenz umgeformt wird, wobei die Impulse durch 'einen Zähler gezählt v/erden und nach Erreichen einer Sollwert- Impulszahl der Schweissvorgang abgebrochen wird. Dadurch wird erreicht, dass die zugeführte Ξchweissenergie ent¬ sprechend der Sollwert-Schweissenergie sehr genau eingehal¬ ten und zudem bestimmte Umgebungseinflüsse, z.B. Aussen- temperatur, Temperatur der Muffe o.dgl., berücksichtigt werden.The invention is therefore based on the object of designing a method of the type described in the introduction in such a way that the greatest possible number of influencing factors is taken into account at least approximately. This object is achieved according to the invention in that the quadratic value of the the same is formed and converted into a pulse frequency corresponding to this value, the pulses being counted by a counter and the welding process being terminated after a setpoint pulse number has been reached. This ensures that the welding energy supplied corresponds very precisely to the setpoint welding energy and that certain environmental influences, for example the outside temperature, the temperature of the sleeve or the like, are also taken into account.
Eine weitere Sicherheit bezüglich der Ausführung einer Schweissverbindung wird durch ein für die Durchführung des erfindungsgemässen Verfahrens geeignetes Gerät mit einem, eine nach Dosierung der Schweissenergie ausschaltbare Schaltstufe aufweisenden Stromkreis dadurch erreicht, dass der Schaltstufe Mittel zu ihrer Unterbrechung zugeordnet sind, wenn eine Unterbrechung des Stromkreises auftritt.A further security with regard to the execution of a welded connection is achieved by a device suitable for carrying out the method according to the invention with a circuit having a switching stage which can be switched off after metering the welding energy in that the switching stage is assigned means for interrupting it when an interruption in the circuit occurs .
Die Erfindung ist in der Zeichnung in einem Ausführungsbei- spiel dargestellt und nachfolgend beschrieben. Die Zeich¬ nung zeigt eine schematische Darstellung eines Geräts zum Verbinden von Rohrleitungselementen aus schweissbarem Kunststoff, das als Blockdiagramm dargestellt ist.The invention is shown in the drawing in an exemplary embodiment and described below. The drawing shows a schematic representation of a device for connecting pipe elements made of weldable plastic, which is shown as a block diagram.
Das in der Zeichnung dargestellte Gerät ist für die Her¬ stellung von Verbindungen vor allem mit Schweissmuffen vor¬ gesehen, jedoch besteht grundsätzlich keine Einschränkung bezüglich seiner Verwendung für Schweissverbindungen anderer Art, z.B. Muffenverbindungen o.dgl.The device shown in the drawing is intended for the production of connections, especially with welded sockets, but there is in principle no restriction with regard to its use for other types of welded connections, e.g. Socket connections or the like
Die Stromversorgung des in der Figur dargestellten Geräts erfolgt über einen Netzanschluss 1. Der Stromkreis wird über eine Schaltstufe 7 geführt. Am Ausgang der Schaltstufe ist eine Schweiss uffe 3 über einen schematisch dargestellten. Steckkontakt 4 angeschlossen. Am Ausgang der Schaltstufe 7 ist eine Stromüberwachung 6 angeordnet. Diese überwacht den fliessenden Strom und hält die Schaltstufe, die bei¬ spielsweise ein Relais aufweist, in Arbeitsstellung.The device shown in the figure is supplied with power via a mains connection 1. The circuit is routed via a switching stage 7. At the output of the switching stage a welding sleeve 3 over a schematically shown. Plug contact 4 connected. A current monitor 6 is arranged at the output of the switching stage 7. This monitors the flowing current and keeps the switching stage, which has a relay, for example, in the working position.
Am Stromkreis ist ein Netzteil 2 angeschlossen, mittels welchem eine Kleinspannung, z.B. 12 Volt, erzeugt wird, die zur Versorgung des Geräts dient. Die Ausgangsspannung des Netzteils 2 wird in einem Messumformer 8 gemessen undA power supply unit 2 is connected to the circuit, by means of which a low voltage, e.g. 12 volts, is generated, which serves to supply the device. The output voltage of the power supply 2 is measured in a transmitter 8 and
2 in eine quadratische Nachbildung der Netzspannung U um¬ geformt. Der Ausgang des Messumformers 8 ist mit dem Ein¬ gang eines Impulsgenerators 9 verbunden, der eine dem Quadrat der Spannung entsprechende Impulsfrequenz erzeugt. Dieser quadratische Wert wird aus der Ladungskurve eines Kondensators gebildet, der über einen Widerstand direkt oder- indirekt von der an der Schweissmuffe liegenden Spannung gespeist wird. Wird dieser Kondensator an eine Gleichspannungsqüelle geschaltet, so kann die Kondensator- spannung höchstens bis zur Höhe der Speisespannung steigen Seine Zeitkonstante T, d.h. die Zeit, in der 63% der maximal möglichen Kondensatorspannung erreicht wird, wird aus der Gleichung T = C • R bestimmt, wobei C die Kapazitä •des Kondensators und R seinen ohmschen Widerstand bedeutet Der Anstieg der Kondensatorspannurfg erfolgt in bekannter Weise nicht linear, sondern nach der Gleichung2 reshaped into a quadratic replica of the mains voltage U. The output of the transmitter 8 is connected to the input of a pulse generator 9 which generates a pulse frequency corresponding to the square of the voltage. This quadratic value is formed from the charge curve of a capacitor, which is fed directly or indirectly from the voltage at the welding socket via a resistor. If this capacitor is connected to a DC voltage source, the capacitor voltage can only rise up to the level of the supply voltage. Its time constant T, ie the time in which 63% of the maximum possible capacitor voltage is reached, is determined from the equation T = C • R , where C is the capacitance • of the capacitor and R is its ohmic resistance. The rise in the capacitor voltage is not linear, as is known, but according to the equation
-t/T U = U (1 - e ) wobei U die KondensatorSpannung, U die-t / T U = U (1 - e) where U is the capacitor voltage, U the
Ladespannung und t die Ladezeit bedeuten. Wird bei Errei¬ chen einer vorbestimmten Ladespannung der Kondensator mittels einer Schaltstufe, die z.B. einen Komparator auf¬ weist, entladen, so beginnt ein neuer Ladevorgang und man erhält eine Frequenz, die von der Ladespannung bzw. von der Netzspannung gesteuert wird.Charging voltage and t mean the charging time. If the capacitor is reached when a predetermined charging voltage is reached, e.g. has a comparator, discharges, a new charging process begins and a frequency is obtained which is controlled by the charging voltage or by the mains voltage.
J Die Nachbildung der quadratischen Funktion der Netzspannung im Bereich von z.B. 180 - 260 V kann dadtirch erreicht werden, dass der Schaltpunkt der Entladung z.B. auf einen Wert von 0,39 der Netzspannung bei 220 V festgelegt wird. Weicht die Spannung von diesem Wert ab, erfolgt eine Ueber- kompensation der quadratischen Netzspannung. Diese Ueber- kompensation ist bei kleineren Netzspannungen erforderlich, um den grösseren Wärmeabfluss im Kunststoffmaterial, der durch die längere Schweisszeit auftritt, entgegenzuwirken. Die Schweisszeit wird dadurch nicht nur entsprechend der kleineren Netzspannung, sondern darüber hinaus zusätzlich verlängert. Es kann dadurch eine gleichbleibende Schweiss- güte erreicht werden, auch wenn bei einer Spannung von z.B. 180 V die Schweisszeit um den. Faktor 1,5 ansteigt. In gleicher Weise kann durch entsprechende Wahl des Teil¬ wertes der Ladespannung bzw. Netzspannung eine Ueberkom- pensation bei Spannungen erreicht werden, die über dem festgelegten Wert der Ladespannung bzw. Netzspannung liegen.J The quadratic function of the mains voltage in the range of, for example, 180-260 V can be simulated by setting the discharge switching point, for example, to a value of 0.39 of the mains voltage at 220 V. If the voltage deviates from this value, the quadratic mains voltage is overcompensated. This overcompensation is necessary for smaller mains voltages in order to counteract the greater heat flow in the plastic material, which occurs due to the longer welding time. This not only increases the welding time according to the lower mains voltage, but also extends it further. This enables a constant welding quality to be achieved, even if the welding time is around the same at a voltage of 180 V, for example. Factor increases. In the same way, by appropriately selecting the partial value of the charging voltage or mains voltage, overcompensation can be achieved at voltages which are above the specified value of the charging voltage or mains voltage.
Der Ausgang des Impulsgenerators ist an einen Zähler 10 gelegt, in welchem die Aufsummierung der Impulse erfolgt.The output of the pulse generator is applied to a counter 10, in which the summation of the pulses takes place.
8 24 Die Kapazität des Zählers 10 beträgt z.B. 2 - 2 Im¬ pulse. Entsprechend der Abhängigkeit der Impulsfrequenz des Impulsgenerators 9 vom quadratischen Wert der Spannung bedeutet eine im Zähler 10 aufsummierte Impulszahl eine be- .stimmts Heizenergie.8 24 The capacity of counter 10 is e.g. 2 - 2 pulses. Corresponding to the dependency of the pulse frequency of the pulse generator 9 on the quadratic value of the voltage, a pulse number added up in the counter 10 means a certain heating energy.
Wesentlich ist, dass beim Schweissen der Schweissmuffe 3 die der Schweissenergie entsprechende Impulszahl im Zähler 10 erreicht wird. Dies wird durch eine Funktionsüberwachung 5 sichergestellt. Falls der Zähler 10 seine vorbestimmte Impulszahl noch nicht erreicht hat, z.B. bei einem Unter¬ bruch im Stromkreis zwischen dem Gerät und der Schweiss¬ muffe während des Schweissens, so erzeugt die Funktions-It is essential that when the welding sleeve 3 is welded, the number of pulses corresponding to the welding energy is reached in the counter 10. This is ensured by function monitoring 5. If the counter 10 has not yet reached its predetermined number of pulses, e.g. in the event of an interruption in the circuit between the device and the welding sleeve during welding, the functional
OMPI Überwachung 5 ein Störsignal, z.B. das Blinken einer roten Kontrollampe. Sobald das Störsignal einsetzt, wird damit angezeigt, dass die durchgeführte Schweissung der Muffe 3 überprüft werden muss. Gleichzeitig mit der Anzeige des Störsignals erfolgt eine sofortige Abschaltung der Netz¬ spannung von der Schweissmuffe 3 durch die Schaltstufe 7. Das Einschalten des Stromkreises durch Einschalten der Schaltstufe 7 wird durch eine Einschaltüberwachung 11 ge¬ steuert. Mittels einer Kleinspannung wird von der Ein¬ schaltüberwachung 11 festgestellt, ob am Stromkreisausgang 4 eine Schweissmuffe 3 oder ein äquivalenter Widerstand . angeschlossen ist. Zweckmässig wird die Einschaltüber¬ wachung so ausgelegt, dass das Einschalten des Stromkrei¬ ses nur dann möglich ist, wenn der Verbraucherwiderstand kleiner als ein bestimmter Wert, z.B. 3 K Ohm, ist.OMPI Monitoring 5 an interference signal, eg the flashing of a red indicator lamp. As soon as the interference signal sets in, this indicates that the welding of the sleeve 3 must be checked. Simultaneously with the display of the interference signal, the mains voltage is immediately switched off from the welding sleeve 3 by the switching stage 7. The switching on of the circuit by switching on the switching stage 7 is controlled by a switch-on monitor 11. By means of a low voltage, the switch-on monitoring 11 determines whether a welding sleeve 3 or an equivalent resistor is at the circuit output 4. connected. The switch-on monitoring is expediently designed in such a way that the switching on of the current circuit is only possible if the consumer resistance is less than a certain value, for example 3 K ohms.
Mit dem beschriebenen Gerät wird ein Maximum an Betriebs¬ sicherheit gewährleistet. Der Ausgang für den Stromkreis des Geräts ist so lange gesperrt, bis. ein Verbraucherwider¬ stand mit einem unter einem Grenzwert liegenden Wider¬ standswert angeschlossen ist. Erst dann sperrt die Ein¬ schaltüberwachung 11 nicht mehr und die Schaltstufe 7 kann mittels einer nicht dargestellten Taste eingeschaltet werden.With the device described, maximum operational reliability is guaranteed. The output for the circuit of the device is blocked until. a consumer resistor with a resistance value below a limit value is connected. Only then does the switch-on monitor 11 no longer lock and the switch stage 7 can be switched on by means of a key (not shown).
Aber auch die Umgebungseinflüsse werden mindestens teil¬ weise ausgeschaltet. Da die Heizenergie aufgrund der Span-However, the environmental influences are also at least partially switched off. Since the heating energy due to the
2 nung nach der Formel U • t/R ermittelt wird, hat dies zur2 is determined according to the formula U • t / R, this has to
Folge, dass bei tiefen Umgebungstemperaturen die Schweiss- leistung grösser ist, vorausgesetzt allerdings, der verv/end elektrische Widerstandsheizdraht sei ein Kaltleiter. Eben¬ so kann ein die Form der Schweissmuffe berücksichtigender Formfaktor bei der Abhängigkeit der Spannung bzw. seines quadratischen Wertes von der Impulsfrequenz berücksichtigt werden. Durch die hohe Zählerkapazität ist es möglich, die Schweisszeit, die in der Grössenordnung von z.B. 70 - 80 see liegen kann, sehr genau einzuhalten und auch Zeiten von mindestens 20 min Dauer noch ausreichend sicher zu er¬ fassen.Consequence that the welding power is higher at low ambient temperatures, provided, however, that the used electrical resistance heating wire is a PTC thermistor. Likewise, a form factor taking into account the shape of the welding sleeve can depend on the tension or its quadratic value of the pulse frequency are taken into account. Due to the high counter capacity, it is possible to adhere very precisely to the welding time, which can be in the order of magnitude of, for example, 70-80 lake, and to reliably record times of at least 20 minutes.
Wesentlich ist, dass durch diese Auslegung des Geräts der Aufbau desselben sehr einfach wird und gleichzeitig gegen¬ über den bekannten Ξchweissgeräten eine wesentliche Ge¬ wichtsersparnis, die bis 80% und mehr betragen kann, er¬ reicht wird.It is essential that this design of the device makes the structure of the device very simple and, at the same time, a substantial weight saving, which can be up to 80% and more, is achieved compared to the known welding devices.
fCfREfCfRE
OMPI Λ WIPO OMPI Λ WIPO

Claims

P a t e n t a n s p r ü c h e Patent claims
1. Verfahren zum Verbinden von Rohrleitungselementen aus schweissbarem Kunststoff durch Schweissen ihrer Enden durch elektrische Widerstandsheizung, dadurch gekenn¬ zeichnet, dass aus der Messung der Schweissspannung der quadratische Wert derselben gebildet und in eine diesem Wert entsprechende Impulsfrequenz umgeformt wird, wobei die Impulse durch einen Zähler gezählt werden und nach Erreichen einer Sollwert-Impulszahl der Schweissvorgang abgebrochen wird.1. A method for connecting pipe elements made of weldable plastic by welding their ends by means of electrical resistance heating, characterized in that the quadratic value of the latter is formed from the measurement of the welding voltage and converted into a pulse frequency corresponding to this value, the pulses being counted by a counter be counted and the welding process is stopped after reaching a setpoint pulse number.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, dass bei nicht vollständiger Leerzählung ein Störsignal, z.B. nach einem bestimmten Zeitintervall, ausgelöst wird.2. The method according to claim 1, characterized in that in the case of incomplete empty counting an interference signal, e.g. after a certain time interval.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeich¬ net, dass der quadratische Spannungswert durch Aufladung eines Kondensators über einen Widerstand und Entladung desselben über eine Schaltstufe nach Erreichen einer, einem bestimmten Teilwert der Schweissspannung ent¬ sprechenden Ladespannung gebildet wird.3. The method according to claim 1 or 2, characterized in that the quadratic voltage value is formed by charging a capacitor via a resistor and discharging the same via a switching stage after reaching a charging voltage corresponding to a certain partial value of the welding voltage.
4. Gerät zur Durchführung des Verfahrens nach Anspruch 1, mit einem Stromkreis, der eine Nachdosierung der vor¬ bestimmten Schweissenergie ausschaltbare Schaltstufe aufweist, dadurch gekennzeichnet, dass der Schaltstufe (7) Mittel (5) zu ihrer Unterbrechung zugeordnet sind, wenn eine Unterbrechung des Stromkreises ausserhalb des Geräts auftritt. 4. Apparatus for carrying out the method according to claim 1, with a circuit which has a metering of the predetermined welding energy switchable switching stage, characterized in that the switching stage (7) are assigned means (5) for their interruption when an interruption of the Circuit outside of the device occurs.
5. Gerät nach Anspruch 4, dadurch gekennzeichnet, dass die Mittel (5) eine Anzeigevorrichtung, z.B. ein optisches oder akustisches Signal, aufweisen.Apparatus according to claim 4, characterized in that the means (5) are a display device, e.g. have an optical or acoustic signal.
O PI O PI
PCT/CH1979/000055 1978-04-24 1979-04-23 Process and apparatus for joining tube elements of weldable synthetic material WO1979000973A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH4406/78 1978-04-24
CH440678A CH633746A5 (en) 1978-04-24 1978-04-24 METHOD AND DEVICE FOR CONNECTING PIPELINE ELEMENTS FROM WELDABLE PLASTIC.

Publications (1)

Publication Number Publication Date
WO1979000973A1 true WO1979000973A1 (en) 1979-11-29

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AT (1) AT368264B (en)
CA (1) CA1125388A (en)
CH (1) CH633746A5 (en)
DE (2) DE2945196C1 (en)
FR (1) FR2424118A1 (en)
GB (1) GB2038508B (en)
IT (1) IT1112733B (en)
NL (1) NL191577C (en)
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WO (1) WO1979000973A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001118A1 (en) * 1979-10-29 1981-04-30 A Kullberg A process and a device for hot working
EP0067621A2 (en) * 1981-06-16 1982-12-22 Brintons Limited Jointing fabrics
EP0076043A2 (en) * 1981-09-30 1983-04-06 Fusion Plastics Limited Electro-fusion fitting

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH653611A5 (en) * 1981-12-23 1986-01-15 Fischer Ag Georg METHOD AND DEVICE FOR WELDING LINE ELEMENTS.
JPS63160818A (en) * 1986-12-24 1988-07-04 Sekisui Chem Co Ltd Electric fusing equipment
CN111959047A (en) * 2019-05-20 2020-11-20 株式会社可乐丽 Structure of composite flexible pipe for crude oil and natural gas transportation and laying method thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL80153C (en) * 1949-07-16
CH605082A5 (en) * 1976-03-12 1978-09-29 Rollmaplast Ag Plastic tube welding control

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH518790A (en) * 1970-01-22 1972-02-15 Gebert & Cie Process for achieving a practically constant final temperature when connecting plastic molded parts by means of electrically heatable plastic fittings and a control device for carrying out the process

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL80153C (en) * 1949-07-16
CH605082A5 (en) * 1976-03-12 1978-09-29 Rollmaplast Ag Plastic tube welding control

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001118A1 (en) * 1979-10-29 1981-04-30 A Kullberg A process and a device for hot working
EP0067621A2 (en) * 1981-06-16 1982-12-22 Brintons Limited Jointing fabrics
EP0067621A3 (en) * 1981-06-16 1984-08-01 Brintons Limited Jointing fabrics
EP0076043A2 (en) * 1981-09-30 1983-04-06 Fusion Plastics Limited Electro-fusion fitting
EP0076043A3 (en) * 1981-09-30 1983-06-01 Fusion Plastics Limited Electro-fusion fitting

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DE2945196D2 (en) 1980-11-13
CH633746A5 (en) 1982-12-31
IT7922126A0 (en) 1979-04-24
NL191577B (en) 1995-06-01
SE416279B (en) 1980-12-15
NL191577C (en) 1995-10-03
GB2038508B (en) 1982-10-20
FR2424118A1 (en) 1979-11-23
DE2945196C1 (en) 1989-08-03
AT368264B (en) 1982-09-27
ATA901179A (en) 1982-01-15
JPS6315905B2 (en) 1988-04-06
CA1125388A (en) 1982-06-08
GB2038508A (en) 1980-07-23
SE7909893L (en) 1979-11-30
JPS55500194A (en) 1980-04-03
FR2424118B1 (en) 1984-06-29
IT1112733B (en) 1986-01-20
NL7903071A (en) 1979-10-26

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