Chassis Frame With Spring Cup

Abstract

A chassis frame for a bogie of a rail vehicle which includes at least one longitudinal member having an upper chord and a lower chord, wherein the longitudinal member has at least one end portion, a central portion, and a transition portion lying between the end portion and the central portion, and the end portion of the longitudinal member is formed as a spring cup for receiving a primary spring, where in order to improve the rigidity curve between the spring cup and the transition portion the lower chord is provided with a curvature in the region of the transition portion, where the curvature is formed such that the imaginary extension of the lower chord and the upper chord itself or the imaginary extension of the upper chord intersect in the end portion.

Claims

1-10. (canceled)

11. A chassis frame for a bogie of a rail vehicle, comprising; at least one longitudinal member having an upper chord, a lower chord, at least one end portion, a central portion, and a transition portion lying between the end portion and the central portion, said end portion of the longitudinal member being formed a spring cup for receiving a primary spring suspension; wherein the lower chord has a curvature in a region of the transition portion, which is configured such that an imaginary extension of the lower chord and the upper chord itself or the imaginary extension of the upper chord intersect in the end portion.

12. The chassis frame as claimed in claim 11, wherein an end of the lower chord and an end of the upper chord enclose an angle which is in a region of 60° up to 90°.

13. The chassis frame as claimed in claim 11, wherein the longitudinal member has a first cross-section which is box-shaped at least in sections in the transition portion.

14. The chassis frame as claimed in claim 12, wherein the longitudinal member has a first cross-section which is box-shaped at least in sections in the transition portion.

15. The chassis frame as claimed in claim 11, wherein the longitudinal member has a first cross-section formed as an I-profile at least in sections in the transition portion.

16. The chassis frame as claimed in claim 12, wherein the longitudinal member has a first cross-section formed as an I-profile at least in sections in the transition portion.

17. The chassis frame as claimed in claim 11, wherein the spring cup comprises (i) a spring base for receiving the primary spring suspension and (ii) a jacket for enclosing sections of the primary spring suspension; wherein the jacket of the spring cup has at least one continuation which contacts at least in sections with a section of the lower chord having the curvature.

18. The chassis frame as claimed in claim 17, wherein the lower chord forms the jacket of the spring cup at least in sections.

19. The chassis frame as claimed in claim 17, wherein the at least one continuation of the spring cup contacts the lower chord in a non-curved section which faces the central portion of the longitudinal member.

20. The chassis frame as claimed in claim 18, wherein the at least one continuation of the spring cup contacts the lower chord in a non-curved section which faces the central portion of the longitudinal member.

21. The chassis frame as claimed in claim 17, wherein the upper chord forms the spring base.

22. The chassis frame as claimed in claim 17, wherein the spring base is a plate-shaped element which is connected at least to the upper chord.

23. The chassis frame as claimed in claim 22, wherein the spring base has a fork-like connection section for connection to the upper chord and the lower chord.

24. The chassis frame as claimed in claim 12, wherein the angle is in a region of 70° up to 90°.

25. The chassis frame as claimed in claim 24, wherein the angle is in a region of 80° up to 90°.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] For further explanation of the invention, reference is made to the figures in the following part of the description from which further advantageous embodiments, details and developments of the invention can be derived. The figures are to be understood as exemplary and although they should demonstrate the character of the invention they should not under any circumstances restrict or even definitively represent the character in which:

[0025] FIG. 1 shows a side view of a chassis frame in accordance with the prior art;

[0026] FIG. 2 shows a view of the underside of a chassis frame in accordance with the prior art;

[0027] FIG. 3 shows a side view of an embodiment of a chassis frame in accordance with the invention;

[0028] FIG. 4 shows a view of the underside of a chassis frame in accordacne with the invention;

[0029] FIG. 5 shows a cross-section through a longitudinal member of a chassis frame in accordance with the invention along line AA from FIG. 3;

[0030] FIG. 6 shows an illustration of a bogie having a chassis frame in accordance with the invention;

[0031] FIG. 7 shows an axonometric view of an alternative embodiment of a chassis frame in accordance with the invention; and

[0032] FIG. 8 shows a further axonometric view of an alternative embodiment of a chassis frame in accordance with the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0033] FIGS. 1 and 2 show an offset longitudinal member 1 of a chassis frame for a bogie in accordance with the prior art with an upper chord 2 and a lower chord 3. Here, the longitudinal member 1 has a central portion 6 stepped downward in the operating state, on which a transverse member 13 is arranged. Starting from the central portion 6, two transition portions 5 angled with respect to the central portion are formed, each of which ends in an end portion 4, which end portions 4 extend essentially parallel to the central portion 6. Consequently, only one side of the longitudinal member 1 will be described in detail, where the statements naturally also apply to the other side.

[0034] Upper chord 2 and lower chord 3 extend approximately parallel in the central portion 6, over a large part of the transition portion 5 and in the end portion 4, and are connected to one another via side walls (not illustrated) to form a closed first (here box-shaped) cross-section 7 (see Fig. 5). In this situation, the end portion 4 forms a spring cup 8 that serves to receive a primary spring suspension, such as a cylindrical spring, a Flexicoil spring or a leaf spring, of the bogie. Here, the spring cup B comprises a spring base 10 upon which the primary spring suspension bears and via which spring base 10 the primary spring suspension is centered. In addition, the spring cup 8 also comprises a jacket 11 that surrounds the primary spring suspension in the region of the end portion 4 of the longitudinal member 1.

[0035] In order to enable the primary spring suspension to be received in the spring cup 8, the lower chord 3 is taken only as far as the jacket 11 of the spring cup 8 in the end portion 4 and surrounds the jacket 11 at least along a section of the jacket surface. In other embodiments, the lower chord 3 is formed as a support for the jacket 11 and reaches under said jacket 11 at least in sections, where in this case the lower chord 3 has an opening, through which the primary spring suspension enters the spring cup 8. There are a plurality of further embodiments that will not be discussed here because they all encounter the same problem.

[0036] In the transition region to the spring cup 8 the cross-section switches from the closed box-shaped cross-section 7 (see, e.g. FIG. 5) to an open cross-section, which is due to receiving the primary spring suspension. This causes the occurrence of an abrupt and unfavorable change in the rigidity curve of the longitudinal member 1, in which case the placement of weld seams for connecting the spring cup 8 or the jacket 11 thereof to the upper chord 2 or lower chord 3 also has a negative influence on the curve. The ends of the weld seams constitute particularly vulnerable zones and in the exemplary embodiment described lie in the highly stressed section between spring cup 8 and the transition portion 5 of the longitudinal member 1.

[0037] FIG. 2 shows an alternative view of the embodiment described above of a chassis frame in accordance with the prior art, where the side of the chassis frame receiving the primary spring suspension is illustrated. In particular, the transverse member 13 connected to the central portion 6 of the longitudinal member 1 can be seen here. It can likewise be seen from this figure that the jacket 11 of the spring cup 8 has a rectangular cross-section that is rounded at the corners, and that the jacket 11 is partially enclosed by the lower chord 3.

[0038] FIGS. 3 to 6 now relate to an embodiment of a chassis frame in accordance with the invention. The longitudinal member 1 likewise has a central portion 6, two end portions 4 and two transition portions 5 and is connected in the central portion 6 to a transverse member 13. The differences with regard to the definition of the portions will be described in the following.

[0039] It can be clearly seen in FIG. 3 that in accordance with the invention, the lower chord 3 has a curvature 9 that is formed such that the lower chord 3 closes the box-shaped cross-section 7 in the transition portion 5 in that the lower chord 3 is curved in the direction of the upper chord 2. Here, the radius of curvature or the radius of an osculating curve is chosen to be as large as structurally possible in order to obtain favorable stress conditions. In the exemplary embodiment, the lower chord 3 and thus naturally also an imaginary extension of the lower chord 3 intersect the upper chord 2 directly, whereby an angle of 90° is enclosed between the upper chord 2 and the extension of the lower chord 3. At the closing end of the upper chord 2 and of the lower chord 3 a weld seam is provided that connects upper chord 2 and lower chord 3. The boundary between the transition portion 5 of the longitudinal member 1 and the end portion 4 lies at that location at which upper chord 2 and lower chord 3 intersect, where the interface itself is attributed both to the transition portion 5 and also to the end portion 4.

[0040] Such a configuration offers a plurality of advantages. On the one hand, when viewed in the direction of the transverse member 13, upper chord 2 and lower chord 3 form a continuous closed profile that enables an optimized rigidity curve. On the other hand, the force acting on the longitudinal member 1 is distributed directly to upper chord 2 and lower chord 3.

[0041] A further aspect of the invention relates to the formation of the spring cup 8 which, in conjunction with the aforementioned, results in particularly advantageous synergies. The jacket 11 of the spring cup has, at each side, a continuation 12 that engages around the lower chord 3, in other words makes contact with the lower chord in that region exhibiting the curvature 9. Here, as a general rule, the continuation 12 is in each case connected to the lower chord 3 close to or at the longitudinal edge of the lower chord 3. This means that a weld seam, which connects the spring cup 8 to the lower chord 3, can be made considerably longer, which means that the thickness of the weld seam can be reduced and in particular one end of the weld seam can be arranged in a less stressed section of the lower chord 3 that lies closer to the central portion 6. In this case, the continuations 12 are taken right into a section behind the curvature 9, in which the lower chord 3 is essentially rectilinear. Here, the jacket 11 can he produced from one piece, or can be constructed from a plurality of plate members connected to one another, preferably welded. A width of the continuation, in other words that dimension that specifies the distance of the outer edge of the continuation 12 to the edge making contact with the lower chord 3 is at least 100 to 150 mm in this situation, where widths greater than 150 mm are generally to be preferred, if this is permitted by other assemblies of the chassis frame.

[0042] In order to route the primary spring suspension, it is necessary for the primary spring suspension to be surrounded around its full circumference by the jacket 11. In the exemplary embodiment described, in the section exhibiting the curvature 9 and connected to the upper chord 2 the lower chord 3 forms a part of the jacket surface 11, more precisely the side surface of the jacket 11 facing the transverse member 13.

[0043] The spring base 10 of the spring cup 8 is formed by the upper chord 2. In alternative embodiments, the spring base 10 is however a separate component which is connected to the upper chord 2, preferably welded. This means that the spring base 10 can, in a simple manner, have a greater thickness than the upper chord 2 itself. In order to enable an optimum connection to a lower chord 3 curved in accordanc with the invention, the spring base 10 can, in this situation, have a fork-like connection section, where at least one of the forks is connected to the lower chord 3 and at least one of the forks is connected to the upper chord 2 so that the weld seams do not run directly in the region of the interface of upper chord 2 and lower chord 3.

[0044] The configuration in accordance with the invention of the jacket 11 of the spring cup 8 having the continuations on both sides can be clearly seen from FIG. 4.

[0045] FIG. 6 shows a chassis frame in accordance with the invention in a bogie. In this case, in particular, primary springs 14 are inserted into the spring cups 8 that are connected at that end situated opposite the spring base 10 to a wheelset 15. At the same time, the wheelset 15 is attached via a wheelset guide 16 to the chassis frame. The continuations 12 of the jacket 11 are taken as far as the part of the wheelset guide 16 attached to the chassis frame and are connected to that part, preferably welded. A secondary spring 17 is arranged centrally in the central portion 6 of the longitudinal member 1. In addition to the springs, damper elements 18 are also arranged on each of the springs 14,17.

[0046] FIGS. 7 and 8 show a three-dimensional illustration of an alternative embodiment of a longitudinal member 1 in accordance with the invention, in particular of the transition portion 5 and of the end portion 4. In contrast to the first exemplary embodiment, the first cross-section 7 in the present embodiment is formed as an I-profile, where the upper chord 2 and the lower chord 3 are connected by a crosspiece 19. The spring cup 8 itself can likewise be easily recognized, together with its jacket 11 and the continuation 12 that engages around the curvature 9 in sections. In particular, FIG. 8 shows the spring cup 8 clearly, so that it can be clearly seen where the primary spring 14 is arranged in a bogie.

[0047] Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those element steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements shown described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.