Method for producing a base frame for a car body of a rail vehicle and base frame

Abstract

The invention relates to a method for manufacturing a floor frame (100) for a car body for a rail vehicle (1) comprising the following steps: - providing at least one plate-shaped central section element (101) and - fixing at least two longitudinal elements (105), a central longitudinal beam (107), at least two side longitudinal beams (111) in the direction of the longitudinal axis of the rail vehicle and several transverse elements (113) transverse to the longitudinal axis of the rail vehicle on one side (103) of the plate-shaped central section element (101) by means of laser welding.

Description

[0001] The invention relates to a method for manufacturing a floor frame for a car body of a rail vehicle. The invention further relates to a floor frame for a car body of a rail vehicle manufactured according to the method of the invention.

[0002] In the construction of rail vehicles, almost all vehicle components are subject to high demands regarding stiffness and weight. These demands are further increased by the ever-growing number of additional requirements for various equipment features, such as environmentally friendly air conditioning systems that operate without harmful greenhouse gases but are significantly heavier. At the same time, the permissible wheel loads must not be exceeded in order to avoid impermissible stresses and to minimize energy consumption during operation. The vehicle body in general, and in particular the underframe or floor frame of a rail vehicle, accounts for a large proportion of the vehicle's total weight.

[0003] WO 2020 / 133934 A1 describes a rail vehicle with a chassis.

[0004] CN 102 180 172 A describes a flat rail transport wagon with a chassis.

[0005] The underframe or chassis of a rail vehicle must therefore possess the necessary rigidity and load-bearing capacity to withstand the forces occurring during operation and maintenance. In addition, the underframe must comply with weight restrictions to prevent the rail vehicle from becoming unnecessarily heavy. Furthermore, the manufacturing processes of rail vehicle components are subject to economic considerations.

[0006] The invention is based on the objective of providing an improved method for manufacturing a floor frame for a car body for a rail vehicle and a correspondingly manufactured floor frame.

[0007] This problem is solved by the method for manufacturing a floor frame for a car body for a rail vehicle and by the floor frame according to the independent claims. Advantageous embodiments are the subject of the dependent claims.

[0008] According to one aspect of the invention, a method for manufacturing a floor frame for a car body for a rail vehicle is specified, wherein at least one plate-shaped central section element is provided and wherein at least two longitudinal elements, a central longitudinal beam, at least two side longitudinal beams in the direction of or substantially parallel to the longitudinal axis of the rail vehicle and several transverse elements transverse to the longitudinal axis of the rail vehicle are fixed on one side of the plate-shaped central section element by means of laser welding.

[0009] By fixing the individual elements—i.e., the longitudinal elements, the central beam, the at least two side beams, and the transverse elements—to one side of the plate-shaped central section using laser welding techniques, the lower heat input required for laser welding compared to standard MAG welding allows the central section element to be manufactured with a thinner wall, as there is no risk of the reduced wall thickness burning through the central section element during laser welding. Furthermore, the reduced number of elements used—i.e., the longitudinal elements, the central beam, the at least two side beams, and the transverse elements—compared to conventional construction methods, ensures a sufficiently high, comparable stability as well as the necessary rigidity and load-bearing capacity of the base frame. In particular, a load-bearing capacity can be achieved.Stiffness in a transverse direction of the base frame is ensured and improved. This thus enables the production of a weight-reduced base frame.

[0010] By using only one central longitudinal beam according to the invention, the floor frame is made more torsionally flexible, thus increasing safety with regard to derailment of the rail vehicle.

[0011] By using laser welding to join the individual elements, which results in significantly less heat input due to the lower line energy, the base frame can be manufactured with considerably smaller tolerances than is possible with conventional construction methods.

[0012] Consequently, the base frame consists largely of flat sheets, for example, which cannot form any pockets or closed chambers for moisture and dirt, thus significantly reducing the risk of corrosion.

[0013] This allows the process for manufacturing the base frame to be simplified technically and made more cost-effective.

[0014] This in turn means that fewer adjustments are needed when assembling the entire car body of the vehicle, and the car body can also be assembled more cost-effectively.

[0015] According to one embodiment of the invention, the at least one plate-shaped central element is joined from several sub-elements by means of laser welding. This eliminates the need for costly special manufacturing equipment for producing the central element, which is required for manufacturing a one-piece, plate-shaped central element in the conventional design of rail vehicles.

[0016] By using laser welding technology, the wall thickness of the sub-elements, for example simple, flat sheets, can be further reduced without compromising the load-bearing capacity of the central sub-element constructed in this way.

[0017] According to a preferred embodiment of the invention, the at least one plate-shaped central part element is designed with different material thicknesses, wherein the central part element is designed with a thicker material thickness at least at the points where the central longitudinal beam and the at least two side longitudinal beams are fixed to the central part element.

[0018] This allows for precise and targeted reinforcement of the areas of the central section element, specifically its wall thickness, where the main loads occur during vehicle operation, while maintaining a thinner wall thickness in the remaining areas. This enables the central section element, and consequently the floor frame, to be optimized for reduced weight.

[0019] According to a preferred embodiment of the invention, the central longitudinal beam is designed as an I-beam.

[0020] The design of the central longitudinal beam, which is located in the middle of the central section element and extends in the longitudinal direction of the vehicle and is the essential load-bearing element of the chassis of the rail vehicle, as an I-beam is particularly advantageous due to this shape in order to absorb corresponding stresses or forces, especially with regard to the deflection of the chassis and its stress in the longitudinal direction of the vehicle.

[0021] According to a preferred embodiment of the invention, the central longitudinal beam is joined by welding at least one top chord, one web, and one bottom chord. According to a further preferred embodiment of the invention, the top chord, the web, and the bottom chord are each made with different wall thicknesses. Due to the multi-part design of the central longitudinal beam, the individual parts can be optimized according to their function. For example, the web, which is arranged between the top and bottom chords, can be given a desired shape by means of the cutting process, which corresponds to the required pre-tensioning with respect to the base frame. Furthermore, according to the invention, the top and / or bottom chords can thus have their dimensions, in particular width and / or thickness, with respect to their connection at the top or bottom, especially the top chord with the central section element.Regarding wall thickness, it can be designed accordingly, depending on the requirements. The wall thickness of the web can also be customized and, in particular, differ from that of the top and / or bottom chord, so that the intermediate girder can be assembled in a way that meets the stress requirements and uses minimal material.

[0022] According to a preferred embodiment of the invention, the bridge is designed with recesses.

[0023] By incorporating appropriate, force-flow-optimized recesses, for example in the form of a kind of truss structure, the bridge can also be designed to be weight-optimized.

[0024] According to a further preferred embodiment of the invention, the central longitudinal beam and the at least two side longitudinal beams are designed over the entire length of the at least one plate-shaped central part element in the direction of, or substantially parallel to, the longitudinal axis of the rail vehicle.

[0025] This further improves the necessary rigidity and load-bearing capacity of the rail vehicle's underframe. Furthermore, the side longitudinal beams provide a seal for the vehicle's door openings, which can each be formed, for example, by a flat sheet metal panel running the entire length, with a material thickness optimized for weight. Advantageously, the side longitudinal beams are welded to the top of the central section element with a thicker sheet metal panel using a T-joint, without any overlapping. The same applies to the top flange of the central longitudinal beam.

[0026] According to the invention, the base frame is designed with at least one outer area, wherein the at least one outer area is fixed to the central part element by means of laser welding, and wherein the at least one outer area has at least one plate-shaped outer part element, on one side of which at least one outer longitudinal beam and several transverse elements are fixed by means of laser welding.

[0027] At least one outer section can thus be advantageously assembled using the same construction method as the central section; that is, in particular the outer longitudinal beam, but also the transverse elements are each welded to all other adjacent elements, for example, sheet metal, by means of T-joints and then attached to the central section. This eliminates any overlaps in these areas, thereby permanently preventing areas susceptible to corrosion.

[0028] Thus, the laser welding technique avoids material doubling that would occur, for example, with spot welding, because the individual elements are fixed directly to the central or outer section element via their respective fixing edges, thereby preventing corrosion between such parallel surfaces. This increases the load-bearing capacity and, in particular, the durability of the base frame.

[0029] According to a preferred embodiment of the invention, the at least one plate-shaped outer part element is joined together from several part elements by means of laser welding.

[0030] By using laser welding technology, the wall thickness of the sub-elements, for example simple, flat sheets, can be further reduced without compromising the load-bearing capacity of the outer sub-element constructed in this way.

[0031] According to a preferred embodiment of the invention, the at least one plate-shaped outer part element is designed with different material thicknesses, wherein the outer part element is designed with a thicker material thickness at least at the points where the at least one outer longitudinal beam is fixed to the outer part element.

[0032] This allows for precise and targeted reinforcement or increase of the wall thickness of the outer component element where the main loads occur during vehicle operation, while maintaining a thinner wall thickness on the remaining surfaces. This enables further optimization of the outer component element and, consequently, the floor frame in terms of weight reduction.

[0033] According to a preferred embodiment of the invention, the outer longitudinal beam is designed as a C-beam.

[0034] This particularly improves the stability of the outer edge of the base frame.

[0035] According to a preferred embodiment of the invention, the base frame is made of a metal material.

[0036] This allows for the advantageous provision of a stable and durable floor frame.

[0037] According to a preferred embodiment of the invention, the floor frame is made of corrosion-resistant steel. This eliminates the need for any corrosion protection measures during both the manufacturing and maintenance of the floor frame, i.e., throughout the entire life cycle of the vehicle. This simultaneously increases the vehicle's longevity and reduces maintenance requirements.

[0038] According to a second aspect of the invention, a floor frame for a car body of a rail vehicle is provided, wherein the floor frame is manufactured according to the method for manufacturing a floor frame for a rail vehicle according to one of the preceding embodiments.

[0039] This allows for the provision of an improved floor frame for a rail vehicle, which has the aforementioned technical advantages.

[0040] The features and advantages of this invention described above, as well as the manner in which they are achieved, will be made clearer and more easily understood by the explanations of the following highly simplified, schematic representations of preferred embodiments.

[0041] Each of these shows: FIG 1 a schematic perspective view of a floor frame for a car body for a rail vehicle according to one embodiment, FIG 2a schematic representation of the underside of a floor frame for a car body for a rail vehicle according to one embodiment, FIG 3 a schematic representation of a floor frame for a car body for a rail vehicle in top view according to one embodiment and FIG 4 A detailed section of a schematic representation of the underside of a floor frame for a car body for a rail vehicle according to one embodiment. FIG 1 Figure 1 shows a schematic perspective view of a floor frame 100 for a car body for a rail vehicle 1 according to one embodiment.

[0042] In the illustrated embodiment of the invention, an overview of the essential components of a floor frame 100 for a car body of a rail vehicle 1 is shown. This frame consists of a central section 102 and two outer sections 117, which adjoins and is attached to or integrated with other parts of the underframe of the vehicle 1, in particular the vehicle head 3. Furthermore, corresponding door openings 5 ​​are shown, which are provided for the doors that are installed during the further manufacturing of the rail vehicle 1.

[0043] The main components of the central part 102 are at least one plate-shaped central part element 101, which in this case is formed in one piece, but can alternatively also be made from several sub-elements, for example corresponding flat sheets, by joining them together by means of laser welding.

[0044] Another key component is a central longitudinal beam 107, which is the essential load-bearing element of the underframe 100 of the rail vehicle 1 and is located in the center of the central section element 101, preferably extending longitudinally over the entire length of the central section 102 of the vehicle 1. The use of only one central longitudinal beam 107 according to the invention results in a more torsionally flexible underframe 100, thus increasing safety with regard to derailment of the rail vehicle 1.

[0045] The lateral termination of the central section 102, on the right and left respectively in the longitudinal direction of the vehicle, is formed in this case by two side longitudinal beams 111, which, to further reinforce the rigidity and load-bearing capacity of the floor frame 100, also extend longitudinally of the vehicle 1, preferably over the entire length of the central section 102. The two side longitudinal beams 111 form, in particular, the termination of the central section 102 at the door openings 5.

[0046] The two outer sections 117 are connected to the central section 102 in the area of ​​the side longitudinal beams 111 and each have at least one plate-shaped outer element 119, which is formed in one piece in the present case, but can alternatively also be joined together from several partial elements, for example corresponding flat sheets, by means of laser welding, as well as an outer longitudinal beam 121 as a termination. Further elements and further details, in particular individual manufacturing steps according to the inventive method for manufacturing a floor frame 100, are described in the following Figures 2 to 4 illustrated and explained.

[0047] FIG 2 Figure 1 shows a schematic representation of the underside of a floor frame 100 for a car body for a rail vehicle 1 according to one embodiment.

[0048] To manufacture a central section 102 of a floor frame 100 according to the invention, a necessary number of longitudinal elements 105 can preferably first be attached, depending on the embodiment, to one side 103 of a provided, plate-shaped central section element 101, essentially parallel to the longitudinal axis of the vehicle. Then, the central longitudinal beam 107 in the middle of the central section element 101 and the two side longitudinal beams 111 on the outer sides, right and left, can also be attached, essentially parallel to the longitudinal axis of the vehicle, by laser welding. Afterward, the transverse elements, or crossbeams 113, can be attached transversely, i.e., essentially perpendicular to the longitudinal axis of the vehicle, also preferably by laser welding. The transverse elements 113 themselves can be designed differently depending on requirements, position, and function.For reasons of stability, it is particularly advantageous to attach the transverse elements to side 103 of the central section element 101 at essentially equal intervals, although deviations from this are permissible without restriction if necessary. The outer sections 117 can then be manufactured in the same sequence and subsequently connected to the central section 102 between the door openings 5 ​​by means of laser welding. Specifically, this means that an outer longitudinal beam 121 is first attached to one side of a provided, plate-shaped outer section element 119, essentially parallel to the vehicle's longitudinal axis, as the lateral termination of the respective outer section 117, by means of laser welding. The corresponding transverse elements, or crossbeams 113, can then be attached transversely, i.e., essentially perpendicular to the vehicle's longitudinal axis, also by means of laser welding.Here too, the transverse elements 113 themselves can be designed differently depending on requirements, position and function. It is also advantageous here to attach the transverse elements 113 to the outer part element 119 at essentially equal intervals to one another, and furthermore preferably in line with the crossbeams 113 of the middle part 102, although deviations from this are permitted without restriction if necessary.

[0049] The preferred manufacturing sequence described here, in particular the application of the highly stressed transverse elements 113 in the final steps at the end of the process, results in a higher positional accuracy and thus advantages in the final assembly of a rail vehicle. However, if necessary, the described sequence can be deviated from in any practical way, and the manufacturing steps can be modified accordingly and carried out in a different order.

[0050] To provide a stable and durable floor frame 100, the floor frame 100 is preferably made of a metal material. For this purpose, predominantly flat or planar 2D sheets or sheets with a bent edge to which devices, cables, etc. can be attached are used.

[0051] Since the manufacturing process according to the invention, and in particular the supplementary use of laser welding technology, does not result in any material doubling or gaps, the base frame 100 can also be made of corrosion-resistant steel, so that any corrosion protection measures can be dispensed with over the entire life cycle of the vehicle 1, thereby increasing the longevity of the vehicles while simultaneously reducing maintenance costs.

[0052] FIG 3 shows a schematic representation of a floor frame 100 for a car body for a rail vehicle 1 in top view according to the embodiment shown in Figure 2 .

[0053] In Figure 3 The outer areas 117 between the door openings 5 ​​are already attached to the middle part 102. Figure 3 The figure shows in particular areas with a thicker wall thickness 123 and areas with a thinner wall thickness 125. The central section element 101 has areas of thicker wall thickness 123 precisely where the central longitudinal beam 107 and the two side longitudinal beams 111 are fixed to the central section element 101 by means of laser welding, or where the outer longitudinal beams 121 are fixed to the outer section elements 119, i.e., from below in this illustration, i.e., where the load centers occur during vehicle operation. All other areas 125 of the central section element 101, the central section 102, and the outer section elements 119 of the outer areas 117, in contrast, have a thinner wall thickness.

[0054] Thus, the middle section 102 as well as the attached outer areas 117 and therefore the base frame 100 as a whole can be optimized with regard to a reduced weight.

[0055] FIG 4 shows a detailed section of the schematic representation of the underside of a floor frame 100 for a car body for a rail vehicle 1 according to the embodiment shown in Figure 2 .

[0056] The detail shown depicts a part of side 103 of the central element 101 of the central part 102 of the area where the outer areas 117 are attached to the central element 101 and each adjoin a door opening 5 by means of a special end piece.

[0057] In the areas with thicker wall thickness 123 of the middle section element 101 or the outer section elements 119, the two side longitudinal beams 111, the middle longitudinal beam 107 and the two outer longitudinal beams 121 are fixed essentially parallel to the longitudinal direction of the vehicle on one side 103.

[0058] The remaining areas 125 have a thinner wall thickness, to which longitudinal elements 105 are also fixed essentially parallel to the vehicle's longitudinal direction, and transverse elements or cross braces 113 are fixed transversely to the vehicle's longitudinal direction. The cross braces 113 are designed differently depending on their position and function, as shown.

[0059] The outer longitudinal beams 121 are designed as C-beams because this shape is particularly advantageous with regard to the stability of the closure of the outer areas 117 of the base frame 100 to the outside.

[0060] The central longitudinal beam 107 is designed as an I-beam.

[0061] This shape is particularly advantageous in order to absorb corresponding stresses or forces, especially with regard to deflection of the base frame 100 and stresses in the longitudinal direction of the vehicle 1.

[0062] Furthermore, the intermediate longitudinal beam 107 is constructed in multiple sections and essentially consists of a top chord 108, a web 109, and a bottom chord 110, joined by welding. This allows the individual parts to be optimally designed according to their function. For example, the web 109, which is located between the top chord 108 and the bottom chord 107, can be precisely cut to the desired shape, corresponding to the required pre-bracing with respect to the base frame 100. Additionally, the top chord 108 and / or bottom chord 107, particularly the connection between the top chord 108 and the intermediate section element 101, can be designed with a corresponding width and / or thickness, or wall thickness, depending on the requirements.The wall thickness of the web 109 can therefore be individually designed and, in particular, differ from the upper chord 108 and / or lower chord 110, so that the intermediate longitudinal beam 107 can be joined or assembled in a way that meets the stress requirements and at the same time uses the least amount of material and is therefore weight-optimized.

[0063] To further optimize the weight of the base frame 100, the web 109 is designed with corresponding, force-flow-optimized recesses 115, for example in the form of a kind of truss structure.

[0064] Cutouts of various shapes, for example circular, elliptical, etc., are possible depending on the possibilities and requirements, as can be seen also with other sub-elements, such as the side longitudinal beams 111 or the crossbeams 113, to further reduce the weight of the base frame 100.

[0065] A floor frame 100 with such reduced or optimized weight can therefore be installed in the car body of a rail vehicle, for example a tram.

[0066] Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived by the person skilled in the art without leaving the scope of protection of the invention.

Claims

1. Method for producing a base frame (100) for a car body of a rail vehicle (1) with the following steps: - providing at least one central part element (101) embodied in a plate-shaped manner and - fixing at least two longitudinal elements (105), of a central longitudinal member (107), of at least two lateral longitudinal members (111) in the direction of the rail vehicle longitudinal axis and a number of transverse elements (113) at right angles to the rail vehicle longitudinal axis on a side (103) of the plate-shaped central part element (101) by means of laser welding, characterised in that the base frame (100) is realised with at least one outer region (117), wherein the at least one outer region (117) is fixed to the central part element (101) by means of laser welding and wherein the at least one outer region (117) has at least one outer part element (119) which is embodied in a plate-shaped manner, on the one side of which at least one outer longitudinal member (121) and a number of transverse elements (113) are fixed by means of laser welding.

2. Method according to claim 1, characterised in that the at least one central part element (101) embodied in a plate-shaped manner is assembled from several part elements by means of laser welding.

3. Method according to claim 1 or 2, characterised in that the at least one central part element (101) embodied in a plate-shaped manner is realised with different material thicknesses, wherein the central part element (101) is realised with a thicker material thickness (123) at least at the points at which the central longitudinal member (107) and the at least two lateral longitudinal members (111) are fixed to the central part element (101).

4. Method according to one of claims 1, 2 or 3, characterised in that the central longitudinal member (107) is realised as an I-member.

5. Method according to claim 4, characterised in that the central longitudinal member (107) is assembled at least from an upper belt (108), a web (109) and a lower belt (110) by means of welding.

6. Method according to claim 5, characterised in that the upper belt (108), the web (109) and the lower belt (110) are each realised with different wall thicknesses.

7. Method according to claim 5 or 6, characterised in that the web (109) is realised with cutouts (115).

8. Method according to one of the preceding claims, characterised in that the central longitudinal member (107) and the at least two lateral longitudinal members (111) are realised across the entire length of the at least one central part element (101) embodied in a plate-shaped manner in the direction of the rail vehicle longitudinal axis.

9. Method according to one of the preceding claims, characterised in that the at least one outer part element (101) embodied in a plate-shaped manner is assembled from several subelements by means of laser welding.

10. Method according to one of the preceding claims, characterised in that the at least one outer part element (119) embodied in a plate-shaped manner is realised with different material thicknesses, wherein the outer part element (119) is realised with a thicker material thickness (123) at least at the points at which the at least one outer longitudinal member (121) is fixed to the outer part element (119).

11. Method according to one of the preceding claims, characterised in that the outer longitudinal member (121) is configured as a C-member.

12. Method according to one of the preceding claims, characterised in that the base frame (110) is manufactured from a metallic material.

13. Method according to one of the preceding claims, characterised in that the base frame (100) is manufactured from corrosion-resistant steel.

14. Base frame (100) for a car body of a rail vehicle (1), wherein the base frame (100) is manufactured according to the method for producing a base frame (110) for a rail vehicle (1) according to one of the preceding claims 1 to 13.

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