• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    It is proposed a circuit for inductive heating of an optionally embedded in a non-magnetic bed metal with a transformer. The transformer induces eddy currents in the metal as a function of an exciter current IL and an excitation voltage UL and together with the metal to be heated forms a load impedance XL. In addition, a temperature control for the metal to be heated is provided. In order to provide advantageous monitoring conditions, it is proposed that the load impedance XL is preferably operated in the region of its resonant frequency, that the excitation current IL and excitation voltage UL and their phase shift Acp are measured and recorded with respect to each other during heating of the metal and that a temperature profile of excitation current proportional to the phase shift Acp lL, excitation voltage UL and phase shift Acp is calculated.
    公开号:AT512427A1
    申请号:T50006/2012
    申请日:2012-01-17
    公开日:2013-08-15
    发明作者:
    申请人:Ke Kelit Kunststoffwerk Gmbh；
    IPC主号:
    专利说明:

    1
    (38426) HEL
    The invention relates to a circuit for inductive heating of an optionally embedded in a non-magnetic bed metal with a transformer which induces eddy currents in the metal in response to an excitation current and an excitation voltage and forms a load impedance together with the metal to be heated, wherein a temperature monitoring for the metal to be heated is provided.
    Such circuits integrated in welding devices are used, for example, for connecting individual shots of a plastic line. For this purpose, pipes or jacket pipes made of a thermoplastic material are connected to one another via a thermoplastic connecting sleeve. For this purpose, it is known (WO 2007/128384 A2), insert a self-contained ring of a perforated plate between the sleeve and the thermoplastic pipes to be connected, in order then with the aid of an induction coil enclosing the sleeve in the region of the perforated metal sheet ring To induce eddy currents through which the sheet metal ring is heated with the result that the thermoplastic material of the sleeve and the jacket pipes to be joined is melted in the connection area, so that established by the perforated plate an intimate weld between the sleeve and the jacket pipes.
    Such a device is also described in A 2058/2010. One of the main advantages of a possible welding method is that for 2 the supply of the required welding energy to the connection sleeve no connection wires are required. As a result, there are no fault zones at the transition between welded and unwelded material, as in the case of heating coil resistance welding methods in the passage region of the connecting wires. As with all methods, however, it is desirable to monitor the welding process in terms of temperature, if necessary, also be able to regulate. So far, this can only be done with a temperature sensor provided in the welding area, but this is impractical for assembly-technical reasons
    The invention is thus based on the object, a circuit for inductive heating of an optionally embedded in a non-magnetic bed metal, in particular for inductive welding a sleeve with the jacket tube of a district heating pipe, so that a determination of the temperature profile in the welding area is possible without the safe To endanger welding. In particular, according to a development of the invention, a monitoring of a complete melting of the welding area and a logging of the weld seam should be possible.
    The invention achieves this object by virtue of the fact that the load impedance is preferably operated in the region of its resonant frequency, that the exciter current and exciter voltage and their phase shift are measured and recorded relative to one another during heating of the metal, and that a temperature profile which is proportional to the phase shift is calculated from excitation current, exciter voltage and phase shift , Advantageous developments of the invention are illustrated in the subclaims.
    In the drawing, the invention is shown schematically in one embodiment. Show it
    1 is a simplified circuit diagram of the circuit according to the invention. FIG. 2 is a diagram illustrating the enthalpy over time during the welding process of a plastic sleeve
    3
    3 shows a diagram of the temperature profile in the welding region of a plastic sleeve over time.
    In order to avoid the system weaknesses - which are associated with the addition or introduction of electrically conductive cables or wires for both welding and for temperature monitoring in the welding zone - a non-contact indirect temperature measurement is provided according to the invention.
    For this purpose, it is necessary to be able to determine the temperature in the secondary coil, ie the closed heating metal, for example a heating metal strip, from parameters which are transmitted via a primary coil during induction welding into the welding generator and evaluated there. The solution of this metrological task will be described below.
    In the present case of application, the energy transfer takes place inductively from a primary air coil to the secondary side, the metal to be heated, a metal band. The temperature of the metal strip must be recorded for process and Prüftechnischen reasons without direct measurement.
    Depending on the material used, the metal strip has a more or less positive or negative temperature coefficient, ie it is made of materials that conduct electricity better at lower temperatures than at higher temperatures. Their electrical resistance thus increases with increasing temperature. This fact is used to detect the temperature during the welding process. As can be seen from the sketch of the block diagram (FIG. 1), the predominantly inductive load circuit is compensated with a parallel capacitance. In FIG. 1, C1 is a parallel capacitance, X1 is a leakage inductance, X2 is an inductance for the magnetization, X3 is a secondary inductance (converted to the primary side) and RL is the temperature-dependent metal resistance, that is to say the band resistance in the example. These regenerators together form the load impedance XL at a supply, to which the excitation current and the exciter voltage are applied.
    4
    In the illustrated model, a resistance change AR1 of the band resistance causes a change in the total resistance Z | _ of the overall circuit. This causes independent of other influences such as power, voltage, and current changes a phase shift in the power supply, between supply voltage Uv and supply current lv- If the circuit operated in the range of the resonant frequency, this leads to very useful results. In particular, AR1 is proportional to AZ1 and AZ1 is equivalent to Aq>, so ARL is equivalent to Δφ. By measuring supply voltage Uv and supply current Iv over time, in particular in real time, it is thus possible to calculate phase shift Δφ in the energy supply and subsequently the resistance Rl of the metal with the aid of the mathematical model. Thus, the resistance profile can be logged during the welding process. Due to the thermistor properties of the metal, that is to say because of the temperature dependence, this resistance profile is proportional to the temperature profile during the welding process.
    R1-R0 * eh (Ti-7b)
    With Ro as nominal resistance at, for example, room temperature To, with b as the material constant and with Tl of the temperature to be determined and assigned to the respective calculated resistance RL.
    A calibration of the circuit can for example be carried out so that the input frequency F of the power supply is changed by AF. On the basis of the model calculation this causes a change of the load impedance X1, in consequence a defined band resistance change AR1 and a defined measured value of Δφ.
    With the invention, a calculated value can be determined, which is proportional to the heating strip temperature and based on the course of which the relative change of the temperature value in the welding area can be very well mapped. All induction heating methods (eg also the bottom plate material for induction stoves), where the secondary winding is made of material with a positive temperature coefficient, could be calibrated and thus monitored for a relative temperature change result by this method.
    An improved and more accurate assignment to a physical quantity (° C, ° K) is possible with the circuit described below. FIGS. 2 and 3 schematically show the melting behavior of a semicrystalline polymer (for example polyethylene). With increasing temperature (T), the enthalpy content H (amount of energy per gram) of the substance increases. Due to their molecular structure, polymers do not have a defined melting point but a melting range, which can be assumed to be the area below the curve of the hatched area.
    With this material property, in the melting process with thermoplastics with the same power supply, before and after the state of aggregate change, a fairly constant increase in temperature takes place (FIG. 3). In the area of crystalline melting (at PE, 142 ° C.), with constant energy input, an increase in temperature in the weld nugget will not take place until the material around the heating metal has predominantly changed to the plasticized state. This delay in the temperature increase at this temperature point is shown in FIG.
    This circumstance we according to the invention used to the effect that in operation always the resistance of the metal formed as a PTC thermistor is calculated and mitlogiert, the resistance bet reaching the melting temperature of the bed until the melting of the bed remains at least almost constant and rises again after melting, and that the temperature profile calculated from the resistance curve is adjusted with the melting temperature associated with the bed material before the temperature profile is stored in a memory.
    With the help of appropriate software support, the recorded measured data are "pinned" to the crystalline melting point temperature after passing through this temperature point during each welding process - and thus the temperature profile
    6 real measured values can be assigned. All values before and after can thus be assigned to an exact, to a few degrees Celsius, sweatband temperature and the log files are shown in the form of appropriate temperature curves, if a balance between the calculated from the resistance curve temperature profile with the bed material own melting temperature. For this purpose, the curve of the calculated temperature profile in the calculated melting range is shifted, for example, by the material-characteristic melting temperature in the direction of the temperature axis.
    Furthermore, the invention relates to an unspecified induction welding device, in particular for induction connection sleeves for fusion bonding weldable thermoplastic body, with a circuit described above.
    权利要求:
    Claims (5)
    [1]
    Patent Attorneys Dipl.-Ing. Helmut Hübscher Dipl.-Ing. 1. A circuit for inductive heating of a metal optionally embedded in a nonmagnetic bed with a transformer which induces eddy currents in the metal as a function of an excitation current L and an excitation voltage U1, and the together with the metal to be heated forms a load impedance Xl, wherein a temperature monitoring is provided for the metal to be heated, characterized in that the load impedance Xl is preferably operated in the region of its resonant frequency that the excitation current L and excitation voltage UL and their phase shift Δφ to each other during heating of the metal are measured and recorded and that one of the phase shift Δφ proportional temperature profile of excitation current II, excitation voltage Ul and phase shift Δφ is calculated.
    [2]
    2. A circuit according to claim 1, characterized in that the excitation frequency F of the applied to the load impedance XL excitation voltage Ul for calibration is changed by AF, causing a phase shift Δφ and a load impedance change AX] _, which is preferably also logged, wherein the associated Exciter current L, the associated exciter voltage Ul and the associated phase shift Δφ is calculated from a mathematical model of the load impedance Xl the change in resistance AB of the designed as a PTC thermistor or metal thermistor.
    [3]
    3. A circuit according to claim 1 or 2, characterized in that always calculated during operation of the resistance of the metal formed as a PTC thermistor or thermistor and preferably mitlogiert, wherein the resistance Rl upon reaching a state of aggregate state, in particular upon reaching the melting temperature of the bed until melting 2 of the bed remains at least nearly constant and rises again only after melting, and that the temperature profile calculated from the resistance curve is adjusted with the melting temperature associated with the bed material before the temperature profile is stored in a memory.
    [4]
    4. A circuit according to any one of claims 1 to 3, characterized in that the metal is embedded in a, in particular a connecting sleeve forming, plastic bed.
    [5]
    5. induction welding machine, in particular for induction connection sleeves for fusion bonding weldable Themoplastkörper, with a circuit according to one of claims 1 to 4. Linz, 17 January 2012 KE-KELIT Kunststoffwerk Gesellschaft m.b.H. by:
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    同族专利:
    公开号 | 公开日
    AT512427B1|2014-01-15|
    US10165628B2|2018-12-25|
    EP2805138B1|2018-10-24|
    DK2805138T3|2019-02-18|
    US20140361007A1|2014-12-11|
    WO2013106877A1|2013-07-25|
    KR102007550B1|2019-10-01|
    EP2805138A1|2014-11-26|
    PL2805138T3|2019-03-29|
    RU2014133551A|2016-03-10|
    KR20140116876A|2014-10-06|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    EP0014729A1|1979-02-26|1980-09-03|Sensor Corporation|A digital eddy current apparatus for identifying specimens of electrically conductive material of unknown composition|
    US5373143A|1991-09-30|1994-12-13|Tocco, Inc.|Apparatus and method of measuring temperature|
    US5573613A|1995-01-03|1996-11-12|Lunden; C. David|Induction thermometry|
    US5760379A|1995-10-26|1998-06-02|The Boeing Company|Monitoring the bond line temperature in thermoplastic welds|
    US6455825B1|2000-11-21|2002-09-24|Sandia Corporation|Use of miniature magnetic sensors for real-time control of the induction heating process|
    EP0082842A1|1981-01-21|1983-07-06|PAYNE, Nicholas John|Sensing temperature variations in a material|
    US5125690A|1989-12-15|1992-06-30|Metcal, Inc.|Pipe joining system and method|
    ES2246640B1|2003-05-15|2006-11-01|Bsh Electrodomesticos España, S.A.|TEMPERATURE REGULATION FOR AN INDUITED HEATING HEATER ELEMENT.|
    EP2021163A2|2006-05-05|2009-02-11|Bindring SA|Method and device for connecting tubes made out of thermoplastic material|
    DE102009047185B4|2009-11-26|2012-10-31|E.G.O. Elektro-Gerätebau GmbH|Method and induction heating device for determining a temperature of a cooking vessel bottom heated by means of an induction heating coil|
    AT510265B1|2010-12-14|2012-03-15|Ke Kelit Kunststoffwerk Gmbh|DEVICE FOR THE INDUCTIVE WELDING OF THE THERMOPLASTIC MANTEL TUBE OF A REMOTE HEATING PIPE WITH A THERMOPLASTIC PLASTIC MUFF|JP6306931B2|2014-04-23|2018-04-04|トクデン株式会社|Induction heating roller device|
    DE102016120043A1|2016-10-20|2018-04-26|Ke-Kelit Kunststoffwerk Gmbh|Thermal bonding of plastic objects by low Curie temperature heating means|
    DE102016120049A1|2016-10-20|2018-04-26|Ke-Kelit Kunststoffwerk Gmbh|Inductive welding of plastic objects by means of a coil arrangement with several individual coils|
    DE102016120037A1|2016-10-20|2018-04-26|Ke-Kelit Kunststoffwerk Gmbh|Inductive welding of plastic objects with electrically interrupted heating means|
    GB2582930A|2019-04-08|2020-10-14|Edwards Ltd|Induction heating method and apparatus|
    法律状态:
    2022-01-15| PC| Change of the owner|Owner name: BRUGG ROHRSYSTEM AG, CH Effective date: 20211116 |
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50006/2012A|AT512427B1|2012-01-17|2012-01-17|CIRCUIT FOR INDUCTIVE HEATING OF METAL|ATA50006/2012A| AT512427B1|2012-01-17|2012-01-17|CIRCUIT FOR INDUCTIVE HEATING OF METAL|
    EP13704343.6A| EP2805138B1|2012-01-17|2013-01-15|Circuit for the inductive heating of a metal|
    RU2014133551A| RU2014133551A|2012-01-17|2013-01-15|DIAGRAM FOR INDUCTIVE HEATING OF METAL|
    PL13704343T| PL2805138T3|2012-01-17|2013-01-15|Circuit for the inductive heating of a metal|
    KR1020147020088A| KR102007550B1|2012-01-17|2013-01-15|Circuit for the inductive heating of a metal|
    US14/372,557| US10165628B2|2012-01-17|2013-01-15|Circuit for the inductive heating of a metal|
    DK13704343.6T| DK2805138T3|2012-01-17|2013-01-15|Circuit for inductive heating of metal|
    PCT/AT2013/050010| WO2013106877A1|2012-01-17|2013-01-15|Circuit for the inductive heating of a metal|
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