DE1069306B

DE1069306B -

Info

Publication number: DE1069306B
Application number: DENDAT1069306D
Authority: DE
Publication date: 1959-11-19

Description

DEUTSCHESGERMAN

Sollen zwei oder mehrere metallische Körper oder Werkstücke miteinander verbunden werden, beispielsweise durch einen Preßvorgang oder dadurch, daß ein zwischen den Körpern belassener Zwischenraum ausgegossen wird, so ist es zur Erzielung einer einwandfreien Verbindung notwendig, die Körper im Bereich der Verbindungsstelle gleichzeitig und gleichmäßig auf eine bestimmte Temperatur zu erwärmen. Handelt es sich dabei nicht um gleichartige Körper, d.h. sollen Körper verbunden werden, die hinsichtlich ihrer Gestalt bzw. ihrer Querschnittsbemessungen und/oder ihres Materials größere Unterschiede aufweisen, so ist eine gleichzeitige und gleichmäßige Erwärmung mit den üblichen Mitteln wie öl- oder Gasflamraen nur schwer zu erreichen. Auch induktive Erhitzungsverfahren bringen nicht ohne weiteres Abhilfe.Should two or more metallic bodies or workpieces be connected to one another, for example by a pressing process or by pouring a gap left between the bodies So in order to achieve a proper connection it is necessary to have the bodies in the area the joint to be heated to a certain temperature at the same time and evenly. Acts These are not bodies of the same kind, i.e. bodies should be connected that are related to their shape or their cross-sectional dimensions and / or their material show major differences, so is a simultaneous and even heating with the usual means such as oil or Difficult to reach gas flames. Inductive heating processes are also not easy to achieve Remedy.

Bei diesen Verfahren ist bekanntlich der Verlauf der Erwärmung sehr von der Frequenz des induzierenden Stromes abhängig. Höhere Frequenzen eignen sich infolge ihrer geringen Eindringtiefe vorzugsweise zur Erwärmung von Körpern schwachen Querschnittes, während starkwandige Körper vorteilhaft mittels niedriger Frequenzen, vorzugsweise durch Netzfrequenz, erwärmt werden. Wollte man beispielsweise innerhalb einer Induktionsspule gleichzeitig einen dickwandigen und einen dünnwandigen Körper erwärmen, so würde sich bei einer dem ersteren angepaßten Frequenz der letztere schlecht bzw. zu langsam erwärmen, und umgekehrt.In these processes, it is known that the course of the heating depends very much on the frequency of the induction Current dependent. Higher frequencies are preferably suitable due to their low penetration depth for heating bodies with a weak cross-section, while thick-walled bodies are advantageous be heated by means of low frequencies, preferably by mains frequency. You wanted to For example, a thick-walled and a thin-walled coil at the same time within an induction coil If the body heats up, if the frequency is adapted to the former, the latter would be poorly resp. heat too slowly and vice versa.

Zur Überwindung der genannten Schwierigkeiten sieht die Erfindung bei einer Vorrichtung zur gleichzeitigen und gleichmäßigen bzw. in einem bestimmten Verhältnis stehenden Erwärmung zweier oder mehrerer nach Form und/oder Material verschiedener metallischer Werkstücke als Wärmeerzeuger eine induktive Heizvorrichtung vor, deren Induktionsspule gleichzeitig durch Ströme zweier oder mehrerer verschiedener Frequenzen gespeist wird.To overcome the difficulties mentioned, the invention provides a device for simultaneous and uniform or proportional heating of two or more Depending on the shape and / or material of various metallic workpieces, an inductive heat generator is used as a heat generator Heating device in front of whose induction coil simultaneously by currents of two or more different Frequencies is fed.

Es ist an sich wohl bekannt, metallisches Gut in einer Induktionsspule nacheinander mit verschiedenen Frequenzen zu erwärmen; und zwar mit niedriger Frequenz bis zum Curiepunkt, während die Weitererwärmung über diesen Punkt hinaus mit höherer Frequenz erfolgt. Es ist dabei auch bekannt, die beiden verschiedenen Frequenzen gleichzeitig anzuwenden. Diese bekannten Verfahren verfolgen jedoch einen völlig anderen Zweck als die vorliegende Erfindung. Sie dienen nämlich dazu, eine wirksame Erhitzung gleichartiger Körper über den Curiepunkt hinaus zu ermöglichen. Für eine gleichzeitige und gleichmäßige Erwärmung zweier oder mehrerer in der Form oder im Metall verschiedener Körper als Vorbereitung zur anschließenden Verbindung dieserIt is well known per se, metallic material in an induction coil successively with different To heat frequencies; with a low frequency up to the Curie point, while the Further heating beyond this point takes place at a higher frequency. It is also known apply the two different frequencies at the same time. Follow these known practices however, for a completely different purpose from the present invention. Namely, they serve to make an effective To enable the same type of body to be heated beyond the Curie point. For a simultaneous and uniform heating of two or more bodies different in shape or in metal than Preparation for the subsequent connection of these

Vorrichtungcontraption

zur gleichmäßigen Erwärmungfor even heating

zweier oder mehrerer nach Form und/oder Material verschiedenertwo or more different in shape and / or material

metallischer Werkstückemetallic workpieces

Anmelder:Applicant:

Brown, Boveri & Cie. Aktiengesellschaft, Mannheim-Käfertal, Boveristr. 22Brown, Boveri & Cie. Aktiengesellschaft, Mannheim-Käfertal, Boveristr. 22nd

Dipl.-Ing. Fritz Hegewaldt, Kirchende über Dortmund, und Hugo Haiverscheid, Dortmund, sind als Erfinder genannt wordenDipl.-Ing. Fritz Hegewaldt, end of the church about Dortmund, and Hugo Haiverscheid, Dortmund, have been named as inventors

Körper oder zu ähnlichen Zwecken sind diese Verfahren bzw. die zu ihrer Durchführung bekannten Einrichtungen nicht geeignet.These processes or those known for their implementation are bodies or for similar purposes Facilities not suitable.

Die erfindungsgemäße Vorrichtung kann zweckmäßigerweise so ausgestaltet werden, daß die Erwärmung der verschiedenen Werkstücke durch entsprechende Leistungssteuerung oder Leistungsregelung der Stromquellen der verschiedenen Frequenzen nach gleichen .oder unterschiedlichen Programmen erfolgt zur Erzielung gleicher oder unterschiedlicher Erwärmungscharakteristiken. Zu diesem Zweck kann die Leistungsbeeinflussung durch Regeltrafos, regelbare Impedanzen oder durch Beeinflussung der Erregung der Stromerzeuger erfolgen.The device according to the invention can expediently be designed so that the heating of the different workpieces by appropriate power control or power regulation of the power sources of the different frequencies according to the same or different programs to achieve the same or different programs Heating characteristics. For this purpose, the power can be influenced by regulating transformers, controllable Impedances or by influencing the excitation of the power generator.

Durch diese Mittel können für die verschieden artig gestalteten Körper erforderlichenfalls in einem gewünschten Verhältnis stehende Erwärmungstemperaturen erzielt werden.By this means can for the differently shaped body if necessary in one Desired ratio standing heating temperatures can be achieved.

In der Fig. 1 ist eine Erhitzungseinrichtung nach der Erfindung dargestellt. Die Induktionsspule 1, in welcher sich die zu erwärmenden Körper befinden, ist bei 2 und 3 an ein Wechselstromnetz angeschlossen, von dem die Spule mit Netzfrequenz gespeist wird. Außerdem wird der Spule 1 Mittelfrequenzenergie über einen Transformator 4 zugeführt, dessen1 shows a heating device according to the invention. The induction coil 1, in which body to be heated is located is connected to an alternating current network at 2 and 3, from which the coil is fed at mains frequency. In addition, the coil 1 receives medium frequency energy fed through a transformer 4, whose

So Primärwicklung bei 5 und 6 an einen nicht dargestellten Mittelfrequenzgenerator angeschlossen ist.So primary winding at 5 and 6 to a not shown Medium frequency generator is connected.

Da die beiden verschiedenen Frequenzen auf ein und demselben Induktor arbeiten, sind Mittel vorgesehen, durch die eine gegenseitige Beeinflussung derSince the two different frequencies work on one and the same inductor, means are provided due to the mutual influencing of the

909' 649/356909 '649/356

Claims

Power sources of different frequency is avoided. These means can consist of sieve elements - such as series and parallel oscillating circuits. The impedances of the current sources or the pre-transformers can serve as parts of the filter elements. In the embodiment shown, a choke coil 7 and a capacitance 8 are connected in parallel in the supply line from the low-frequency network to the induction coil 1, which form a blocking circuit for the medium frequency, while in one of the secondary connections of the transformer 4 with the induction coil 1 there is a capacitance 9 which in connection with the secondary coil of the transformer forms a series resonant circuit tuned to the medium frequency. The most favorable ratio of the two frequencies at which the different types of bodies located in the coil 1 can be brought to the predetermined temperature at the same time after a predetermined heating time can, if necessary, be determined by a few experiments. After the required temperature has been reached, the bodies are connected by means which are known per se and are not shown in the figures, for example by means of a pressing process. The device according to the invention can be used for the simultaneous and uniform heating of a metal piston, for example an aluminum piston, and a steel ring to be connected to this by a casting or pressing process. An embodiment of the invention directed to this application is shown in FIGS. It means 10 an aluminum blank which is to be connected to a piston ring 11 made of steel under the action of heat. With 1 an induction coil is again referred to, which comprises the two bodies 10 and 11 and within which they are held by a holding device (not shown) in a position which already corresponds to or approximates the position which the two bodies are to assume after their union . The heating of the bodies 10 and 11 takes place according to the invention by means of two different frequencies. Fig. 3 shows the finished press connection of the two bodies. If necessary, two or more piston rings can also be heated together with one piston. The invention is not limited to the illustrated embodiment. In particular, the mutual interlocks of the circuits of different frequencies can be designed in a different way. For example, the lower frequency can also be blocked from the medium-frequency transformer by a parallel resonance circuit, while a series resonance circuit can be located in the feed line to the low-frequency power source. Combinations of series and parallel resonance circuits are also possible. Furthermore, the device according to the invention does not necessarily need to be designed for operation with mains frequency and medium frequency, but if this should be necessary due to the workpiece dimensions or the material properties of the body to be connected, other η frequencies, for example also high frequencies, can be used Application. Depending on the intended use of the device, it can also be expedient to use more than two frequencies in one coil. The device according to the invention can readily be adapted for various purposes. It can, for example, be structurally modified or designed so that it can be used to heat the workpieces when rolling a copper plating onto a steel body or when making the connection of two different metal strips for the purpose of making bimetal bodies. Loop-shaped inductors, such as are known per se for heating strip strips on both sides, can also be used. P Λ T E N T A N S P K 0 C U E:

1. Device for simultaneous and uniform or in a certain ratio standing heating of two or more different metallic ones according to shape and / or material Workpieces, characterized in that an inductive heating device is used as the heat generator whose induction coil is used simultaneously by currents of two or more different frequencies is fed.

2. Arrangement according to claim 1, characterized in that the currents of different frequencies can be controlled independently of each other.

3. Arrangement according to claim 1 or 2, characterized in that a mutual influence the power sources of the various frequencies through filter elements, such as. B. series and Parallel resonant circuits, is avoided.

4. Arrangement according to claim 3, characterized in that the impedances of the current sources or the pre-transformers serve as parts of the filter elements.

5. Application of a device according to one of the preceding claims for the simultaneous and uniform heating of an aluminum piston and one with it by potting or the steel ring to be connected by a pressing process.

1 sheet of drawings