INDUCTION HARDENING SYSTEM

Abstract

An induction hardening system for inductively hardening a component includes a first inductor group with at least two inductors configured to heat a region to be hardened on the component, a drive unit configured to move the component along the at least two inductors, and a generator. The at least two inductors are electrically energized by the generator, and the generator is configured to send a current of a same frequency and a same strength to the at least two inductors of the first inductor group.

Claims

1. An induction hardening system for inductively hardening a component, the induction hardening system comprising: at least one inductor group including a first inductor group having at least two inductors configured to heat a region to be hardened on the component, a drive unit configured to move the component along the at least two inductors, and a generator, wherein the at least two inductors of the first inductor group are electrically energized by the generator, and wherein the generator is configured to send a current of a same frequency and a same strength to the at least two inductors of the first inductor group.

2. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are electrically connected to the generator in parallel.

3. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are electrically connected to the generator in series.

4. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are uniformly distributed around a circumference of the component.

5. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are distributed along the component and configured to heat different axial portions and/or different radial portions of the component.

6. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are connected to the generator in series, and wherein a first inductor of the at least two inductors of the first inductor group is structurally different than a second inductor of the at least two inductors of the first inductor group.

7. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group are connected to the generator in series, wherein a first inductor of the at least two inductors of the first inductor group is spaced from the component by a first distance, and wherein a second inductor of the at least two inductors of the first inductor group is spaced from the component by a second distance different than the first distance.

8. The induction hardening system according to claim 1, wherein the at least two inductors of the first inductor group include a first inductor and a second inductor opposing the first inductor, and wherein the first inductor and the second inductor are straight inductors or wherein the first inductor and the second inductor are curved inductors.

9. The induction hardening system according to claim 1, wherein the inductors of the at least one inductor group together cover less than ¼ of a total surface area of the component.

10. The induction hardening system according to claim 1, wherein the inductors of the at least one inductor group together cover less than 1/10 of a total surface area of the component.

11. The induction hardening system according to claim 1, wherein the inductors of the at least one inductor group together cover less than 1/20 of a total surface area of the component.

12. The induction hardening system according to claim 1, wherein the component is a ring, a gear, a roller, a journal, a bush or a disk.

13. The induction hardening system according to claim 1. wherein the at least two inductors of the first inductor group include a first inductor and a second inductor, wherein the first inductor includes a first conductor section facing the component and a second conductor section facing the component, and wherein the first conductor section and the second conductor section are connected to each other in parallel.

14. The induction hardening system according to claim 1. wherein the at least two inductors of the first inductor group include a first inductor and a second inductor, wherein the first inductor includes a first conductor section facing the component and a second conductor section facing the component, and wherein the first conductor section and the second conductor section are connected to each other in series.

15. An inductor for an induction hardening system, comprising: a conductor having a first conductor section configured to face the component and a second conductor section configured to face the component, wherein the first conductor section and the second conductor section are configured to be connected to a generator in parallel.

16. An inductor for an induction hardening system, comprising: a conductor having a first conductor section configured to face the component and a second conductor section configured to face the component, wherein the first conductor section and the second conductor section are configured to be connected to a generator in series.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG. 1 is a schematic representation of an induction hardening system according to a first embodiment of the present disclosure.

[0042] FIG. 2 is a schematic representation of an induction hardening system according to a second embodiment of the present disclosure.

[0043] FIG. 3 is a schematic representation of an induction hardening system according to a third embodiment of the present disclosure.

[0044] FIG. 4 is a schematic representation of an induction hardening system according to a fourth embodiment of the present disclosure.

[0045] FIG. 5 is a schematic representation of a first embodiment of an inductor according to the present disclosure.

[0046] FIG. 6 is a schematic representation of a second embodiment of an inductor according to the present disclosure.

DETAILED DESCRIPTION

[0047] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0048] FIGS. 1 to 4 schematically show a preferred exemplary embodiment of an inductive hardening system 100 that is configured as a pulse hardening system or as a progressive hardening system. In the depicted induction hardening system 100, a component 2, for example, the bearing ring depicted here, is supported on a work table 4, e.g., a rotating table, and can be traversed by induction coils 8-1, 8-2 with the aid of drive devices 6-1, 6-2, 6-3.

[0049] In order to securely fasten the component 2 to the work table 4 or to move the component 2, three drive devices 6-1, 6-2, 6-3 are respectively provided. The drive devices 6-1, 6-2, 6-3 can each include clamping jaws/rollers 10-1, 10-2, 10-3 that are displaceable in the radial direction and configured to hold the component 2 and/or optionally also to rotate the component if the work table is not a rotating table.

[0050] In the exemplary embodiment of the inductive hardening system 100, two inductors 8-1 and 8-2 are associated with an inductor group and are disposed opposite each other. It is of course also possible to use more than two inductors and/or more than one inductor group.

[0051] In particular, it is preferred to use an even number of inductors 8 per inductor group; the inductors 8 are disposed opposite each other and/or distributed evenly around the circumference of the component 2. The forces introduced by the inductors 8 of the corresponding inductor group into the component 2 can thereby be compensated for, since opposing forces cancel each other out. Here it is preferred in particular when opposing inductors 8 are configured identically.

[0052] As can furthermore be seen from FIGS. 1 and 3, the inductors 8-1, 8-2 are not arranged identically in the radial direction, with the result that a coupling distance d2, i.e., the distance between the inductor 8 and the component 2, of the inductor 8-2 is greater than the coupling distance dl of the inductor 8-1. The inductors 8-1, 8-2 can additionally or alternatively also be disposed differently with respect to each other in the axial direction (into the drawing plane or out of it).

[0053] Alternatively or in addition to different coupling gaps D1, D2, the inductors 8-1, 8-2 can also be configured differently geometrically, as shown in FIGS. 2 and 4. In these exemplary embodiments, the inductors 8-1 are each configured as straight inductors, i.e., inductors that do not follow the individual curvature of the component 2, while the inductors 8-2 are configured as curved inductors that are adapted to the curvature of the component 2.

[0054] In order to supply the inductors 8 with current of a certain frequency, voltage, and strength, the inductors are disposed in inductor groups with which a single generator 12 is furthermore associated that supplies all inductors 8 of the inductor group with alternating current of the same frequency, voltage, and strength. In the exemplary embodiments of FIGS. 1 to 4, only two inductors are shown that are associated with an inductor group, and are therefore supplied by a single generator 12 with current of equal frequency, voltage, and strength.

[0055] In the case of a plurality of inductors 8, separate generators would usually be necessary for each inductor 8-1, 8-2, in order to separately control the energy input for each inductor. In addition, according to conventional teaching, only the use of separate generators allows an optimization of the generator power and generator frequency.

[0056] Like the separate generators, the single generator 12 is also supplied with energy from a suitable electric grid; however, the single generator 12 modulates the current frequency and current strength required for the inductors 8 of the associated inductor group for all inductors in the same way.

[0057] With the use of a single generator 12 for energizing all inductors 8 of an inductor group, particularly symmetrical force ratios between the component 2 and the inductors 8 of the inductor group can be achieved. If a symmetrical distribution of the inductors 8 of the inductor group around the component is also provided, asymmetrical coupling distances (as shown in FIGS. 1 and 3) or differently designed inductors (as shown in FIGS. 2 and 4) will not produce asymmetrical forces or contact between the inductor and the component. In addition, there can thereby be no more mutual influencing of magnetic fields of different frequency.

[0058] Furthermore, the energization of several inductors 8 using only a single generator 12 has the advantage that a simpler process control/NC program and a more robust process with regard to possible variances in the coupling distance or a more robust process with regard to possible variances in geometric differences of the individual inductors 8 is possible.

[0059] Due to the use of only a single generator 12, a more robust process is also possible while operating at the limits. In particular, it can thereby be ensured that in the event of a failure or a curtailment of the generator 12, all inductors 8 will be currentless, or curtailed, so that no further forces will act on the component 2. With the use of a plurality of generators, as in the prior art, a failure or a curtailment of a single generator would lead to one-sided forces on the component 2 that in the worst cause contact between the component and the inductor.

[0060] In addition, the drive device 6, in particular its drive components in the form of rollers or retaining components 10, is also protected from excessive wear, since no asymmetrical forces are to be expected and no longer need to be compensated for.

[0061] With the use of a single generator 12, there are in principle two possibilities to integrate the inductors 8 into the current circuit provided by the generator 12. On the one hand, as shown in FIGS. 1 and 2, the inductors 8-1 and 8-2 can be energized in parallel. For this purpose the respective input 14-1, 14-2 of each inductor 8-1, 8-2 is connected to the generator 12 by a current supply line 16-1, 16-2. Furthermore, each current output 18-1, 18-2 of the inductors 8-1, 8-2 is also connected to the generator 12 by a current discharge line 20-1, 20-2. Here the plurality of current supply lines 16-1, 16-2 can be connected directly to a generator output 22 or branch off later from a common current line. In an analogous manner, the separate current discharge lines 20-1, 20-2 can be connected to a generator input 24-1, 24-2, or can combine upstream of the generator 12 into a common current line that is then in turn connected to the generator input 24.

[0062] Alternatively, as depicted in FIGS. 3 and 4, a series circuit of the inductors 8-1, 8-2 can also be realized. Then only an inductor, in the depicted case the inductor 8-1, is energized with current from the generator 12 wherein in this case the current supply line 16-1 connects the generator output 22 to the current input 14-1 of the inductor 8-1. Connected in series, the current discharge line 20-1 connected to the inductor output 18-1 of the first inductor 8-1 functions simultaneously as the current supply line 16-2 for the second inductor 8-2 and is connected to the current input 14-2 of the second inductor 8-2. The current output 18-2 of the second inductor 8-2 is then in turn connected via the current discharge line 20-2 to the input 24 of the generator.

[0063] Even if in FIGS. 1 to 4 only two inductors 8-1, 8-2 are depicted, the above-described energizing principle can also be used for a plurality of inductors.

[0064] Similarly, this means that it is possible to energize groups of inductors in parallel and to energize the inductors of the respective groups in series, or to energize groups of inductors in series and to energize the inductors of the respective groups in parallel.

[0065] Furthermore, with large components 2 or correspondingly large inductors 8, the inductors 8 themselves can also be energized in parallel or in series. FIGS. 5 and 6 accordingly show a parallel energizing (FIG. 5) as well as a series energizing (FIG. 6) of an inductor 8. FIGS. 5 and 6 schematically show the arrangement of a large-surface inductor 8 along a component 2.

[0066] In the depicted exemplary embodiments, the inductor 8 includes an energized conductor 26 facing the component 2; the energized conductor 26 has a first conductor section 26-1 and a second conductor section 26-2. In the case of a parallel circuit of the conductor sections 26-1, 26- 2, as depicted in FIG. 5, the two conductor sections 26-1, 26-2 are separately connected to a current supply line 28, which simultaneously supplies the conductor sections 26-1, 26-2 with current. At both conductor ends 30-1, 30-2 the current is also discharged again and guided out of the inductor 8 by a current discharge line 32.

[0067] In contrast, in the case of a series circuit (see FIG. 6), only one of the conductor sections, in the depicted case the conductor section 26-1, is coupled with the current supply 28, while the other conductor section 26-2 is merely coupled with the current discharge line 32. The conductor sections 26-1, 26-2 are mutually connected to each other by a connection 34 that simultaneously serves as the current discharge from the conductor section 26-1 and current supply for the conductor section 26-2.

[0068] The series circuit offers the advantage that coupling gap differences due to incorrect design of the inductors or poor execution quality, or cost-effective design of the inductors, do not lead to unequal currents in the conductor sections 26-1 and 26-2. Unequal currents would lead here to unequal energy transmission and unequal forces, which the coupling gap differences could in turn negatively influence.

[0069] Overall, the above-described induction hardening system makes possible a stable and reproducible induction hardening process with simple control in that only a single generator must be controlled. In addition, due to the equal current frequency and current strength at all inductors, a reduction of the warpage on the component is possible, since forces are uniformly coupled and the heat input is also equalized. This also allows a reduction of the processing additives and an avoidance of waste due to inductor-component contact, or meltings due to a locally too-high heat input. In addition, the novel energizing makes possible an avoidance or a reduction of the inductor wear.

[0070] A further advantage of a single generator per inductor group is the possibility to supply all inductors of the associated inductor group with identical frequency, current and voltage, and thus to be able to operate the process more uniformly and more stably. In the case of a plurality of generators, this is not possible due to the mutual influencing of the oscillating circuits.

[0071] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved induction hardening systems.

[0072] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention.

[0073] Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0074] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0075] 100 Induction hardening system [0076] 2 Component [0077] 4 Work table [0078] 6 Drive device [0079] 8 Induction coil [0080] 10 Clamping jaw [0081] 12 Generator [0082] 14 Induction coil current input [0083] 16 Current supply line [0084] 18 Induction coil current discharge [0085] 20 Current discharge line [0086] 22 Generator output [0087] 24 Generator input [0088] 26 Induction coil part [0089] 28 Current supply [0090] 30 Conductor end [0091] 32 Current discharge