Under-floor machining for bogies
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- SIEMENS MOBILITY AUSTRIA GMBH
- Filing Date
- 2024-07-12
- Publication Date
- 2026-04-29
AI Technical Summary
Current processing methods for rail vehicle chassis are time-consuming and require precise time and quality control, with existing technologies not effectively synchronizing processing operations across multiple wheel sets and components.
A procedure involving two tools that process different wheel sets or wheels in alternating steps, allowing for flexible movement and positioning, enabling simultaneous or sequential processing of various operations like mechanical and thermal treatments, regardless of wheel positions or intervals, with a hub lift device for adjusting tool access.
This approach enhances maintenance efficiency by allowing synchronized and flexible processing of rail vehicle components, reducing time and increasing flexibility in maintenance operations, while enabling precise process control and quality assurance.
Smart Images
Figure EP2024069884_06022025_PF_FP_ABST
Abstract
Description
[0001] Underfloor machining for chassis
[0002] The invention relates to a method for underfloor machining of running gears of rail vehicles, wherein in a first method step a first wheelset of a rail vehicle or a first wheel of the rail vehicle is machined by means of a first tool and in a second method step a second wheelset of the rail vehicle or a second wheel of the rail vehicle is machined by means of the first tool, wherein a relative movement between the rail vehicle and the first tool is carried out to change the machining position between the first method step and the second method step.
[0003] Rail vehicle bogies may require machining operations that must be performed in a sequence. Such machining operations often result in time-consuming processes. These machining operations may also require precise timing as well as process and / or quality control.
[0004] From the prior art, for example, DE 10 2020 127 991 A1 is known, which describes a method and a device for machining a railway wheel. In the method, a wheel rim of the railway wheel is hardened, wherein a laser spot is projected onto the wheel rim by means of a heat source while the railway wheel rotates. The device with which the method is carried out comprises an underfloor lathe with a clamping device for servicing railway wheel sets. The heat source for projecting the laser spot is assigned to the clamping device.
[0005] Furthermore, DE 10 2017 122 023 A1 shows an underfloor lathe for reprofiling wheels and brake discs of rail vehicle wheelsets. Using the underfloor lathe, wheelsets of different track gauges can be machined. For this purpose, components of a machine stand of the underfloor lathe can be moved relative to one another.
[0006] The invention is based on the object of specifying a method which is further developed compared to the prior art and with which machining processes on the running gear of rail vehicles can be synchronized.
[0007] According to the invention, this object is achieved by a method according to claim 1, in which in a third method step a third wheelset of the rail vehicle or a third wheel of the rail vehicle is machined by means of a second tool and in a fourth method step the first wheelset, a fourth wheelset of the rail vehicle, the first wheel or a fourth wheel of the rail vehicle is machined by means of the second tool, wherein the second tool is moved to change the machining position between the third method step and the fourth method step.
[0008] This measure results in an increase in efficiency in maintenance and / or repair processes on the running gear of rail vehicles. By means of the method according to the invention, running gear wheels and, for example, other wheelset components such as brake discs can be machined. Because the second tool is moved, machining positions on the rail vehicle can be reached flexibly. For example, while the first tool is carrying out a first machining operation on the first wheelset, the second tool can carry out a second machining operation on the third wheelset, etc. Sequential machining processes are also possible. For example, the first tool can machine the first wheelset first, and after such machining of the first wheelset has been completed by the first tool, the second tool can be moved to the first wheelset and continue machining it.For example, the first wheel set can first be subjected to mechanical machining using the first tool (the first tool can be designed, for example, as an underfloor lathe) and then to thermal treatment using the second tool (the second tool can be designed, for example, as a heat source), etc.
[0009] By means of the method according to the invention, machining of wheel sets or wheels is made possible regardless of their positions on the rail vehicle and regardless of their distances from one another.
[0010] Removal of the wheel sets or wheels from the rail vehicle (for example, to carry out the third
[0011] process step or the fourth process step ) can be avoided .
[0012] Further advantageous embodiments of the method according to the invention emerge from the subclaims.
[0013] It is advantageous, for example, if the first method step and the third method step are carried out within a first time interval beginning with a first start time and the second method step and the fourth method step are carried out within a second time interval beginning with a second start time.
[0014] This measure allows the first process step and the third process step to be carried out simultaneously or at an overlapping time.
[0015] A temporal staggering of process steps is achieved if the second process step and the fourth process step are carried out after the first process step and the third process step.
[0016] By this measure, for example, the first wheel set can be machined first using the first tool and then using the second tool. Various sequences are conceivable for carrying out the method according to the invention; for example, it may be helpful if the first method step and the third method step are carried out after the second method step and the fourth method step.
[0017] By this measure, for example, the first wheel set can be machined first using the second tool and then using the first tool.
[0018] An advantageous solution is obtained if the rail vehicle is moved during the relative movement to the processing position change between the first process step and the second process step.
[0019] As a result, for example, an infrastructure can be used for the method according to the invention in which the rail vehicle is arranged, for example, on a maintenance track above a maintenance pit and is positioned by a travel movement on the maintenance track for processing (e.g. of the first wheelset, etc.) relative to a processing machine arranged in the maintenance pit, etc.
[0020] A movement of the second tool parallel to a direction of movement of the rail vehicle is made possible if the rail vehicle is moved translationally along a first trajectory and the second tool is moved translationally along a second trajectory, wherein the first trajectory and the second trajectory are aligned parallel to each other.
[0021] It is also advantageous if mechanical processing is carried out in the first process step and in the second process step.
[0022] Mechanical machining operations may include, for example, turning, milling, rolling, grinding, measurements, testing, or mechanical cleaning treatments, etc. Turning of wheel sets or wheels of rail vehicles (e.g., for profiling or reprofiling of the wheels), etc., is possible when turning is performed as mechanical machining.
[0023] A preferred solution is achieved if thermal processing is carried out in the third and fourth process steps .
[0024] Thermal treatments can include, for example, hardening treatments, tempering treatments, coating treatments, welding treatments or thermal cleaning treatments, etc.
[0025] It is advantageous, for example, to perform hardening treatments as part of the thermal processing. This measure can, for example, increase the wear resistance of wheel sets or wheels of a rail vehicle (e.g., after reprofiling of the wheel sets or wheels), etc.
[0026] Machining of complete circumferences of wheel sets or wheels by means of the second tool is made possible if, in the third method step, the third wheel set or the third wheel is lifted and rotated by means of a lifting and rotating device and, in the fourth method step, the first wheel set, the fourth wheel set, the first wheel or the fourth wheel is lifted and rotated by means of the lifting and rotating device, wherein the lifting and rotating device is moved between the third method step and the fourth method step from a first position below the third wheel set or the third wheel into a second position below the first wheel set, the fourth wheel set, the first wheel or the fourth wheel.
[0027] By moving the lifting and rotating device, machining positions on the rail vehicle can be flexibly reached. Furthermore, a high degree of flexibility is achieved when manipulating wheel sets or wheels of the rail vehicle.
[0028] Precise process control and / or automated quality control are / will be made possible if process parameters are recorded at least during the third process step and during the fourth process step.
[0029] Process parameters that can be recorded include, for example, the power of a heat source, a rotational speed, the duration of a machining operation, and / or thermal energy absorption. Process parameters such as the power of the heat source can also be recorded as time-dependent, rotational speed-dependent, or angle-dependent. Recording the process parameters also enables their storage (e.g., for evaluation).
[0030] A promising field of application for the method according to the invention can be developed with a device for underfloor machining of running gears of rail vehicles, which is configured to carry out the method according to the invention, wherein the device comprises a first tool and a second tool as well as a lifting and rotating device, wherein the first tool is configured to machine a first wheelset of a rail vehicle or a first wheel of the rail vehicle in a first method step and to machine a second wheelset of the rail vehicle or a second wheel of the rail vehicle in a second method step, wherein the second tool is configured to machine a third wheelset of the rail vehicle or a third wheel of the rail vehicle in a third method step and to machine the first wheelset, a fourth wheelset of the rail vehicle,to machine the first wheel or a fourth wheel of the rail vehicle, wherein at least the second tool is designed to be movable for changing the machining position, wherein the second tool is configured to be moved between the third method step and the fourth method step, and wherein the lifting and rotating device is configured to lift and rotate the third wheel set or the third wheel in the third method step, to lift and rotate the first wheel set, the fourth wheel set, the first wheel or the fourth wheel in the fourth method step, and to be moved between the third method step and the fourth method step from a first position below the third wheel set or the third wheel to a second position below the first wheel set, the fourth wheel set, the first wheel or the fourth wheel.
[0031] This measure enables efficient maintenance and / or repair operations on the running gear of rail vehicles, whereby the maintenance and / or repair operations can, for example, be synchronised and staggered in time, etc.
[0032] Use of the device according to the invention in a maintenance and / or repair facility for rail vehicles with a track infrastructure is made possible if the device comprises a track configured to move the rail vehicle thereon, wherein at least the first tool and the lifting and rotating device are arranged at least partially below the track. The invention is explained in more detail below using exemplary embodiments.
[0033] Examples include:
[0034] Fig. 1: A flow chart for an exemplary embodiment of a method according to the invention for underfloor machining of the bogies of a rail vehicle,
[0035] Fig. 2: A schematic side view of an exemplary embodiment of a device according to the invention for underfloor machining of the bogies of a rail vehicle, wherein the rail vehicle is shown in a first machining state,
[0036] Fig. 3: A schematic side view of that exemplary embodiment of a device according to the invention for underfloor machining of bogies of a rail vehicle according to Fig. 2, wherein a section of the rail vehicle is shown in a second machining state, and
[0037] Fig. 4: A schematic floor plan of a section of a wheelset which is heat-treated in a method step of that exemplary embodiment of a method according to the invention for underfloor machining of the running gear of a rail vehicle according to Fig. 1. Fig. 1 shows a flow chart for an exemplary embodiment of a method according to the invention for underfloor machining of the running gear of rail vehicles. By means of the method, a rail vehicle 1 is machined, as shown by way of example in Fig. 2 and Fig. 3.
[0038] In a first method step 2, a first wheel 6 of a first wheelset 10 of a first bogie 14 of the rail vehicle 1 is machined and thereby reprofiled using a first tool 17, which is designed as a turning tool of an underfloor lathe and is shown by way of example in Fig. 2 and Fig. 3. In this process, a first tread and a first flange of the first wheel 6 are turned.
[0039] In a second method step 3, a second wheel 7 of a second wheelset 11 of a second chassis 15 of the rail vehicle 1 is machined by means of the first tool 17 and thereby reprofiled.
[0040] Thus, in the first process step 2 and in the second process step 3, turning operations, which are mechanical operations, are carried out, wherein the first chassis 14 and the second chassis 15 are machined.
[0041] To change the processing position between the first method step 2 and the second method step 3, a relative movement is carried out between the rail vehicle 1 and the first tool 17, in which the rail vehicle 1 is moved on a track 19 above a maintenance pit 20, as shown by way of example in Fig. 2 and Fig. 3. The rail vehicle 1 is moved in a positive axial direction of an x-axis 21, as shown by way of example in Fig. 2 and Fig. 3. In the first method step 2, the first tool 17 is arranged below the first wheel 6, and in the second method step 3 below the second wheel 7.
[0042] In a third method step 4, a third wheel 8 of a third wheel set 12 of the first chassis 14 is machined using a second tool 18, which is designed as a heat source for generating a laser spot with which a second tread and a second wheel flange of the third wheel 8 are scanned, and as shown by way of example in Fig. 2 and Fig. 3. The third wheel 8 was reprofiled using the first tool 17 before the third method step 4.
[0043] In a fourth method step 5, as also shown by way of example in Fig. 4, the first wheel 6 is machined by means of the second tool 18, wherein the first tread and the first flange of the first wheel 6 are scanned by means of the laser spot.
[0044] By scanning with the laser spot, the surfaces of the third wheel 8 and the first wheel 6 are hardened. Thus, in the third process step 4 and the fourth process step 5, hardening treatments, which are thermal processing steps, are carried out.
[0045] In order to change the processing position between the third method step 4 and the fourth method step 5, the second tool 18 is moved. The second tool 18 is arranged at a height level of the track 19 and is guided via first running wheels on first guide rails. In the third method step 4, the second tool 18 is arranged near the third wheel 8, and in the fourth method step 5, it is arranged near the first wheel 6. The second tool 18 is movable along the rail vehicle 1 and the track 19. In order to change the processing position between the first method step 2 and the second method step 3, the rail vehicle 1 is moved translationally along a first trajectory, which is predetermined by the track 19. The second tool 18 is moved translationally along a second trajectory, which is predetermined by the first guide rails.The first traj ectory and the second traj ectory are aligned parallel to each other.
[0046] In the third method step 4, the first chassis 14 with the first wheel set 10, the first wheel 6, the third wheel set 12 and the third wheel 8 is lifted by means of a lifting and rotating device 22, as shown by way of example in Fig. 2 and Fig. 3, wherein the third wheel 8 is rotated by means of rollers of the lifting and rotating device 22, which contact the third wheel 8, for machining by means of the second tool 18.
[0047] In the fourth method step 5, the first chassis 14 with the first wheel set 10, the first wheel 6, the third wheel set 12 and the third wheel 8 is again lifted by means of the lifting and rotating device 22, wherein the first wheel 6 is now rotated by means of the rollers of the lifting and rotating device 22, which now contact the first wheel 6, for machining by means of the second tool 18.
[0048] The lifting and rotating device 22 is designed as a lifting platform, on the upper side of which the rollers for rotating the wheels of the rail vehicle 1 are arranged. On its underside, the lifting and rotating device 22 has second running wheels, via which the lifting and rotating device 22 is movable in the maintenance pit 20 on second guide rails. The lifting and rotating device 22 is arranged on the second guide rails.
[0049] The lifting and rotating device 22 is thus moved between the third method step 4 and the fourth method step 5 from a first position below the third wheel set 12 to a second position below the first wheel set 10.
[0050] The first method step 2 and the third method step 4 are carried out within a first time interval beginning with a first start time.
[0051] The second method step 3 and the fourth method step 5 are carried out within a second time interval beginning with a second start time.
[0052] The second method step 3 and the fourth method step 5 are carried out after the first method step 2 and the third method step 4.
[0053] The first process step 2 and the third
[0054] Process step 4 on the one hand and the second
[0055] Method step 3 and the fourth method step 5, on the other hand, are carried out in staggered time, the first method step 2 being carried out simultaneously with the third method step 4 and the second method step 3 being carried out simultaneously with the fourth method step 5.
[0056] According to the invention, it is conceivable that, for example, the first method step 2 overlaps the third method step 4 in time and the second method step 3 overlaps the fourth method step 5 in time if, for example, the first method step 2 has a longer processing time than the third method step 4 and the second method step 3 has a longer processing time than the fourth method step 5.
[0057] During the first method step 2, the second method step 3, the third method step 4 and the fourth method step 5, wheel speeds and durations of machining operations are recorded as method parameters.
[0058] During the third process step 4 and the fourth process step 5, the power of the heat source and the heat energy absorption by the third wheel 8 and the first wheel 6 are additionally recorded as process parameters in a time-dependent and wheel speed-dependent manner.
[0059] The process parameters are recorded using sensors. The sensor measurement results are transmitted via signal lines to a computer unit in a control center of a maintenance facility, where they are stored and evaluated. The sensor measurement results are also used to control the process via the control center.
[0060] According to the invention, it is also conceivable that in the fourth method step 5, a different wheelset or a different wheel than the first wheelset 10 or the first wheel 6 is machined. For example, a fourth wheelset 13 of a third bogie 16 of the rail vehicle 1 or a fourth wheel 9 of the third bogie 16 can be machined, etc.
[0061] According to the invention, it is further conceivable to carry out the method, depending on requirements and the tools used, in a different processing sequence than that described in connection with Fig. 1. For example, the first method step 2 and the third method step 4 can also be carried out after the second method step 3 and the fourth method step 5, etc.
[0062] Fig. 2 shows a schematic side view of an exemplary embodiment of a device according to the invention for underfloor machining of the running gear of a rail vehicle 1. The rail vehicle 1 is shown in a first machining state. The device is configured to carry out a method according to the invention, as described by way of example in connection with Fig. 1.
[0063] The device comprises a first tool 17, a second tool 18, a lifting and rotating device 22 and a track 19.
[0064] The rail vehicle 1 is arranged on the track 19 and can be moved thereon, for example, in a positive axial direction of an x-axis 21. The track 19 is therefore configured to move the rail vehicle 1 thereon. The rail vehicle 1 has a first bogie 14, a second bogie 15 and a third bogie 16. The first bogie 14 has a first wheelset 10 with a first wheel 6. The second bogie 15 has a second wheelset 11 with a second wheel 7. The first bogie 14 has a third wheelset 12 with a third wheel 8. The third bogie 16 has a fourth wheelset 13 with a fourth wheel 9.
[0065] The first tool 17 and the lifting and rotating device 22 are arranged below the track 19 in a maintenance pit 20. The second tool 18 is arranged at a level with the track 19.
[0066] The first tool 17 is designed as a turning tool of an underfloor lathe and, in the first machining state shown in Fig. 2, is arranged below the first wheel set 10. The first tool 17 is arranged immovably in the maintenance pit 20.
[0067] The second tool 18 is designed as a heat source for generating a laser spot, with which the running surface and flanges of wheels of the rail vehicle 1 can be scanned. The second tool 18 is arranged in the first processing state according to Fig. 2 near the third wheelset 12. The second tool 18 is guided via first running wheels (not shown in Fig. 2) with first drives on first guide rails (not visible in Fig. 2). The first guide rails are aligned parallel to the track 19.
[0068] The lifting and rotating device 22 is designed as a lifting platform, on the upper side of which rollers (not shown in Fig. 2) are arranged for rotating wheels of the rail vehicle 1. On its underside, the lifting and rotating device 22 has second running wheels (not shown in Fig. 2) with second drives, via which the lifting and rotating device 22 is movable in the maintenance pit 20 on second guide rails (not shown in Fig. 2). The lifting and rotating device 22 is arranged on the second guide rails.
[0069] The device is part of a maintenance facility for rail vehicles. The maintenance facility has a control station (not shown in Fig. 2) with a computing unit. The computing unit is connected via signal lines (not shown in Fig. 2) to the first tool 17, the second tool 18, the lifting and rotating device 22 and to sensors (not shown in Fig. 2) of the device and of the rail vehicle 1. This makes it possible to control movements of the second tool 18 and the lifting and rotating device 22 and machining processes of the method according to Fig. 1, and method parameters of the method according to Fig. 1 can be recorded and evaluated in the computing unit.
[0070] The rail vehicle 1 is moved by a train driver who receives corresponding instructions for positioning the rail vehicle 1 via radio from the control center.
[0071] The first tool 17 is configured to machine the first wheel set 10 or the first wheel 6 in a first method step 2 of the method according to Fig. 1 and to machine the second wheel set 11 or the second wheel 7 in a second method step 3 of the method according to Fig. 1. The second tool 18 is configured to machine the third wheel set 12 or the third wheel 8 in a third method step 4 of the method according to Fig. 1 and to machine the first wheel set 10, the fourth wheel set 13, the first wheel 6 or the fourth wheel 9 in a fourth method step 5 of the method according to Fig. 1, wherein the second tool 18 is designed to be movable in order to change the machining position.
[0072] The second tool 18 is thus configured to be moved between the third method step 4 and the fourth method step 5 .
[0073] The lifting and spinning device 22 is configured to lift and rotate the third wheel set 12 or the third wheel 8 in the third method step 4, to lift and rotate the first wheel set 10, the fourth wheel set 13, the first wheel 6 or the fourth wheel 9 in the fourth method step 5, and to be moved between the third method step 4 and the fourth method step 5 from a first position below the third wheel set 12 or the third wheel 8 to a second position below the first wheel set 10, the fourth wheel set 13, the first wheel 6 or the fourth wheel 9.
[0074] Fig. 3 shows a schematic side view of an exemplary embodiment of a device according to the invention for underfloor machining of the running gear of a rail vehicle 1, as is also shown by way of example in Fig. 2.
[0075] Therefore, the same reference numerals are used in Fig. 3 as in Fig. 2.
[0076] While Fig. 2 shows a first processing state, Fig. 3 shows a second processing state.
[0077] The rail vehicle 1 has a first bogie 14, a second bogie 15 and a third bogie 16. The first bogie 14 has a first wheelset 10 with a first wheel 6. The second bogie 15 has a second wheelset 11 with a second wheel 7. The first bogie 14 has a third wheelset 12 with a third wheel 8. The third bogie 16 has a fourth wheelset 13 with a fourth wheel 9.
[0078] In the second machining state, a first tool 17 of the device is arranged below the second wheel set 11, a second tool 18 of the device is arranged near the first wheel set 10 and a lifting and rotating device 22 of the device is arranged below the first wheel set 10.
[0079] Between the first processing state and the second processing state, the rail vehicle 1, the second tool 18 and the lifting-rotating device 22 are moved in a positive direction of an x-axis 21.
[0080] Fig. 4 discloses a schematic plan view of a section of a first wheel set 10, the first wheel 6 of which is heat-treated by means of a method according to the invention, as described by way of example in connection with Fig. 1.
[0081] The method according to Fig. 1 comprises a first method step 2, a second method step 3, a third method step 4 and a fourth method step 5, wherein the first method step 2 and the second method step 3 are carried out by means of a first tool 17 for turning, as shown by way of example in Fig. 2 and Fig. 3, and wherein the third method step 4 and the fourth method step 5 are carried out by means of a second tool 18 for thermal processing.
[0082] Fig. 4 shows the first wheel set 10 during the fourth method step 5. The first wheel 6 is machined by means of the second tool 18, which is designed as a heat source for generating laser spots for hardening treatment, wherein a first running surface and a first flange of the first wheel 6 are scanned by means of the laser spot.
[0083] According to the invention, it is also conceivable that the second tool 18 is designed as a heat source which acts indirectly on the first wheel 6.
[0084] List of names
[0085] 1 rail vehicle
[0086] 2 First procedural step
[0087] 3 Second procedural step
[0088] 4 Third procedural step
[0089] 5 Fourth procedural step
[0090] 6 First wheel
[0091] 7 Second wheel
[0092] 8 Third Wheel
[0093] 9 Fourth wheel
[0094] 10 First wheelset
[0095] 11 Second wheelset
[0096] 12 Third wheelset
[0097] 13 Fourth wheel set
[0098] 14 First landing gear
[0099] 15 Second landing gear
[0100] 16 Third landing gear
[0101] 17 First tool
[0102] 18 Second tool
[0103] 19 track
[0104] 20 maintenance pit
[0105] 21 x-axis
[0106] 22 Lifting and rotating device
Claims
Patent claims 1. A method for underfloor machining of running gear of rail vehicles, wherein in a first method step (2) a first wheelset (10) of a rail vehicle (1) or a first wheel (6) of the rail vehicle (1) is machined by means of a first tool (17) and in a second method step (3) a second wheelset (11) of the rail vehicle (1) or a second wheel (7) of the rail vehicle (1) is machined by means of the first tool (17), wherein a relative movement between the rail vehicle (1) and the first tool (17) is carried out to change the machining position between the first method step (2) and the second method step (3), characterized in that in a third method step (4) a third wheelset (12) of the rail vehicle (1) or a third wheel (8) of the rail vehicle (1) is machined by means of a second tool (18) and in a fourth method step (5) the first wheelset (10),a fourth wheel set (13) of the rail vehicle (1), the first wheel (6) or a fourth wheel (9) of the rail vehicle (1) is machined by means of the second tool (18), wherein the second tool (18) is moved to change the machining position between the third method step (4) and the fourth method step (5).
2. Method according to claim 1, characterized in that the first method step (2) and the third method step (4) are carried out within a first time interval beginning with a first start time and the second method step (3) and the fourth method step (5) are carried out within a second time interval beginning with a second start time.
3. Method according to claim 1 or 2, characterized in that the second method step (3) and the fourth Process step (5) is carried out after the first process step (2) and the third process step (4).
4. Method according to claim 1 or 2, characterized in that the first method step (2) and the third method step (4) are carried out after the second method step (3) and the fourth method step (5).
5. Method according to one of claims 1 to 4, characterized in that the rail vehicle (1) is moved during the relative movement for changing the processing position between the first method step (2) and the second method step (3).
6. The method according to claim 5, characterized in that the rail vehicle (1) is moved translationally along a first trajectory and the second tool (18) is moved translationally along a second trajectory, wherein the first trajectory and the second trajectory are aligned parallel to one another.
7. Method according to one of claims 1 to 6, characterized in that mechanical machining is carried out in the first method step (2) and in the second method step (3).
8. Method according to claim 7, characterized in that turning operations are carried out as mechanical machining operations.
9. Method according to one of claims 1 to 8, characterized in that thermal processing is carried out in the third method step (4) and in the fourth method step (5).
10. A method according to claim 9, characterized in that hardening treatments are carried out as thermal treatments.
11. The method according to one of claims 1 to 10, characterized in that in the third method step (4) the third wheel set (12) or the third wheel (8) is lifted and rotated by means of a lifting and rotating device (22) and in the fourth method step (5) the first wheel set (10), the fourth wheel set (13), the first wheel (6) or the fourth wheel (9) is lifted and rotated by means of the lifting and rotating device (22), wherein the lifting and rotating device (22) is moved between the third method step (4) and the fourth method step (5) from a first position below the third wheel set (12) or the third wheel (8) to a second position below the first wheel set (10), the fourth wheel set (13), the first wheel (6) or the fourth wheel (9).
12. Method according to one of claims 1 to 11, characterized in that at least a first chassis (14) of the rail vehicle (1) and a second chassis (15) of the rail vehicle (1) are machined.
13. Method according to one of claims 1 to 12, characterized in that process parameters are recorded at least during the third process step (4) and during the fourth process step (5).
14. Device for underfloor machining of running gears of rail vehicles, which is configured to carry out the method according to one of claims 1 to 13, wherein the device comprises a first tool (17) and a second tool (18) as well as a lifting and rotating device (22), wherein the first tool (17) is configured to, in a first method step (2), a first wheel set (10) of a rail vehicle (1) or a first wheel (6) of the rail vehicle (1) and, in a second method step (3), to machine a second wheelset (11) of the rail vehicle (1) or a second wheel (7) of the rail vehicle (1), characterized in that the second tool (18) is configured, in a third method step (4), to machine a third wheelset (12) of the rail vehicle (1) or a third wheel (8) of the rail vehicle (1), and, in a fourth method step (5), to machine the first wheelset (10), a fourth wheelset (13) of the rail vehicle (1), the first wheel (6), or a fourth wheel (9) of the rail vehicle (1), wherein at least the second tool (18) is designed to be movable for changing the machining position, wherein the second tool (18) is configured to be moved between the third method step (4) and the fourth method step (5), and wherein the lifting and rotating device (22) is configured toin the third method step (4) to lift and rotate the third wheel set (12) or the third wheel (8), in the fourth method step (5) to lift and rotate the first wheel set (10), the fourth wheel set (13), the first wheel (6) or the fourth wheel (9) and between the third method step (4) and the fourth method step (5) from a first position below the third wheel set, (12) or the third wheel (8) into a second position below the first wheel set (10), the fourth wheel set (13) , the first wheel (6) or the fourth wheel (9).
15. Device according to claim 14, characterized in that the device comprises a track (19) which is configured to move the rail vehicle (1) thereon, wherein at least the first tool (17) and the lifting and rotating device (22) are arranged at least partially below the track (19).