Multiple Temperature-Control Process for Workpieces by Means of a Triplex Furnace

Abstract

Multiple temperature-control process for stators (7) and rotors of electric motors and components consisting of materials with different magnetic properties by means of a triplex furnace (1) for the quick, efficient, and uniform heating-up of preferably tubular components such as stators (7), wherein the magnetic parts of a component are primarily heated up by means of induction and at the same time non-magnetic parts of the same component are primarily heated up by means of infrared radiation, and at the same time and subsequently secondary heating takes place by means of convection, in particular by passive heating elements (10), which serves for finely adjusting the target temperature and for maintaining it.

Claims

1. A multiple temperature-control process for components that comprise different materials with different magnetic and thermal properties, comprising: heating magnetic parts of a component primarily by induction to a target temperature; simultaneously heating non-magnetic parts of the same component primarily by infrared radiation to the target temperature; and simultaneously finely adjusting and/or maintaining the target temperature of the component by convection heating.

2. The multiple temperature-control process according to claim 1, wherein the component is tubular and is simultaneously heated with the induction and with the infrared irradiation, during a primary heating step to ensure quick and uniform heating from inside and from outside of the tubular component.

3. The multiple temperature-control process according to claim 1, wherein heating is by an internal heating source and an external heating source, and wherein intensity of the internal heating source and intensity of the external heating source are regulated and controlled independently of each other according to an energy requirement and the target temperature of the material on or in the component.

4. The multipletemperature-control process according to claim 1, further comprising: rotating the component during heating to ensure uniform temperature distribution and enhanced heat transfer during convective heating.

5. The multiple temperature-control process according to claim 1, wherein convection heating of the component originates partly from an infrared source reflected by the component or the infrared source irradiated past the component.

6. The multiple Multiple temperature-control process according to claim 1, wherein the non-magnetic parts of the component to be heated are electrically conductive and are heated by resistance heating due to high electricity transmission in addition to or as an alternative to infrared irradiation.

7. The multiple Multiple temperature-control process according to claim 1, further comprising: assessing masses and thermal capacity of the magnetic material and the non-magnetic material of the component and determining a required quantity of heat to heat the magnetic material and the non-magnetic material of the component based on the masses of said materials and their thermal capacity, such that the thermal energy acting on each material of a component is supplied as prescribed by a predetermined regimen until the desired quantity of heat is introduced to reach the target temperature.

8. A triplex furnace, comprising: at least one heating station in a thermal chamber, said heating station comprising a primary heater with at least one inductor that is mounted so as to allow movement and at least one infrared radiator that is mounted so as to allow movement; a secondary convection heater; and at least one component transport unit located outside the thermal chamber and having a component rotary drive.

9. The triplex furnace according to claim 8, wherein the secondary convection heater has ferritic passive heating elements that are connected to at least one inductor .

10. The triplex furnace according to claim 8, further comprising actuators to which the at least one inductor and the at least one infrared radiator are connected, so that positions of the at least one inductor and at least one infrared radiator in the heating station may be changed .

11. The triplex furnace according to claim 1, further comprising: a thermally insulated thermal chamber with at least one sealable component feed opening; and a thermal chamber recess running along the direction of movement of the component; temperature sensors lighting and at least one one-way mirrored glass pane .

12. The triplex furnace according to claim 8, wherein the inductor is configured as a flexible hollow body which can optionally be deformed by actuators .

13. The triplex furnace according to-claim 8, further comprising: a temperature control for the at least one inductive heater, a temperature control for the at least one infrared heater, a temperature control for the secondary convection heater, and a temperature control for the at least one component transport unit .

14. The triplex furnace, wherein plurality of heating stations with primary heaters and secondary convection heaters are arranged in series in the thermal chamber .

15. The multiple temperature-control process according to claim 1, wherein the components are stators and rotors of electric motors that comprise soft iron sheets and copper rods.

16. The multiple temperature-control process according to claim 1, further comprising: linearly moving one or more infrared radiators and one or more inductors when heating the component.

17. The multiple temperature-control process according to claim 1, wherein convection heating is introduced by at least one ferritic passive heating element which is tempered by an inductor.

18. The triplex furnace according to claim 8, further comprising one or more infrared light absorbers as passive heating elements for the at least one infrared radiator.

19. The triplex furnace according to claim 11, further comprising: a component transport device which is connected to the thermal chamber; and component carriers associated with the component transport device that project into the thermal chamber and are moved and set in rotation via actuators by means of machine elements.

20. The triplex furnace according to claim 12, wherein the inductor is a copper flex tube or a corrugated copper tube.

Description

DESCRIPTION OF THE DRAWINGS

[0034] The method and an exemplary device in the form of a triplex furnace are explained in more detail in the figures shown in the drawings.

[0035] There is shown in:

[0036] FIG. 1 a possible arrangement of the primary heating elements for simultaneous heating of a stator (7) from inside and outside with different heating sources;

[0037] FIG. 2 a section of an exemplary design of a triplex furnace (1); and

[0038] FIG. 3 a component carrier (6) as an inner clamp with a stator (7) mounted thereon.

DETAILED DESCRIPTION

[0039] FIG. 1 shows a sectional view of a simplified possible arrangement of the active and passive heating elements in the thermal chamber (2), using the example of a component in the form of a stator (7) for electric motors, which essentially consists of a laminated core (7.1) made from soft iron sheets and a copper winding (7.2). The copper rod ends projecting beyond the laminated core on both sides are referred to as the winding head. The laminated core has longitudinal grooves on its inner circumference, into which the copper rods are embedded. The stator (7) is supported, transported, and rotated by a component carrier (6), which is shown here in simplified form as an external tensioner. The thermal chamber (2) is defined by a thermally insulating thermal chamber enclosure (2.1). The thermal chamber enclosure (2.1) comprises at least one slot-shaped recess (2.2) towards the component transport unit (5). Along this recess (2.2) the component carrier (6) and with it also the stator (7) are moved in order to pass from one heating station to the other or from one plant component to the next, all while rotating. For the primary heating of the stator (7), both an inductor (8) arranged on the outside for inductive heating, in particular of the laminated core, and at least one infrared radiator (9) positioned in the central bore of the stator (7) for heating the copper rods can be seen. In conjunction with an actuator and thanks to the movable bearing of the primary heating elements, they can be adapted to different component sizes, in particular to different stator dimensions, or moved into the stators (7). Furthermore, primary heating elements and in particular the inductor (8) can be moved into the effective range of the passive heating elements (10) in order to temper them for convective heating of the thermal chamber (2) and thus of the component. In the case shown, the IR heating tubes are also mounted in a way that they can move axially into and out of the central bore of the stator (7).

[0040] The inductor (8) and/or the IR heating tubes are preferably mounted such as to allow sliding and are connected to actuators for automatic positioning. Thus, the primary heating elements can be adapted to different component dimensions or stator dimensions by means of a control program and, at the same time, can be used as an energy source for the passive heating elements (10) for convective heating of the thermal chamber (2) and the stator (7), e. g., by activating the inductor (8) and moving it into the interaction range of ferritic passive heating elements (10). In this way, the inductor (8) heats either the component or the passive heating element (10). The same method can be used with the IR tubes. Air circulation in the thermal chamber (2) is provided by the rotary motion of the stator (7) and/or a hot air fan (11).

[0041] With this arrangement of heating elements, the stator (7) is heated both from the outside and from the inside by direct heat input by induction into the laminated core and IR radiation into the copper rods and/or additionally and subsequently on all sides by the temperature-controlled air flowing around it, i.e., by convection, to maintain the temperature or to adapt it to the target temperature. The thermal chamber (2) is preferably already heated to the prescribed temperature when the stator (7) is retracted by means of the infrared radiators (9) and the passive heating elements (10).

[0042] FIG. 2 shows a cross-sectional view of a simplified triplex furnace (1) consisting of a component transport unit (5) and a thermal chamber (2). The component carrier (6), which is shown as an inner clamp with a tensioned stator (7), is mounted with its sprockets between chains in the component transport unit (5) and extends into the thermal chamber (2) through a recess (2.2) made along the transport path between the component transport unit (5) and the thermal chamber (2). To allow the axis of the component carrier (6) to move through the sealed recess (2.2), the recess (2.2) is provided with flexible covers, e. g., by means of brushes, curtains, resilient slats, and resilient heat-resistant seals such as inflated silicone hoses. In this illustration, the inductor (8) is arranged externally above the laminated core and the infrared radiators (9) are directed from outside onto the copper rods of the winding heads. The tempered air surrounding the stator (7) for convective heating is not depicted. The thermal chamber (2) consists of an enclosure lined with a thermal insulation layer and at least one component feed opening (3), which is also used for component unloading.

[0043] FIG. 3 shows a component carrier (6) which is equipped as an inner clamp for components with centric bores and carries a stator (7). In the embodiment shown, the component carrier (6) has two sprockets, which are both the bearing points and drive elements for the rotation and transport of the stator (7). The sprockets are supported between chains, as shown in DE 10 2019 004 954.3.

LIST OF REFERENCE NUMERALS

[0044] 1 = Triplex furnace [0045] 2 = Thermal chamber [0046] 2.1 = Thermal chamber enclosure [0047] 2.2 = Thermal chamber recess [0048] 3 = Component feed opening [0049] 4 = Suction opening [0050] 5 = Component transport unit [0051] 6 = Component carriers [0052] 7 = Stator [0053] 7.1 = Laminated core [0054] 7.2 = Copper winding [0055] 8 = Inductor [0056] 9 = Infrared radiator [0057] 10 = Passive heating element [0058] 11= Hot air fan