WELDING UNIT FOR WELDING RAILS OF A TRACK

Abstract

A welding unit for welding rails of a track includes a first sub-unit which is displaceable on unit guides in a rail longitudinal direction relative to a second sub-unit by using displacement cylinders. Each sub-unit includes clamping cylinders disposed underneath the unit guides and coupled to clamping jaws for clamping the rails. The two sub-units are connected by the displacement cylinders in that a cylinder body of the respective displacement cylinder is connected to one sub-unit and a piston rod of the respective displacement cylinder is connected to the other sub-unit. Thus, it is not necessary to support the displacement cylinders relative to a transverse beam disposed at the front.

Claims

1-10. (canceled)

11. A welding unit for welding rails of a track, the welding unit comprising: unit guides extending in a rail longitudinal direction; clamping jaws for clamping the rails; displacement cylinders each having a respective cylinder body and a respective piston rod; first and second sub-units, said first sub-unit being displaceable on said unit guides in said rail longitudinal direction relative to said second sub-unit by said displacement cylinders, each of said sub-units including clamping cylinders disposed underneath said unit guides and coupled to said clamping jaws; and said cylinder body of a respective displacement cylinder being connected to one of said sub-units and said piston rod of said respective displacement cylinder being connected to another of said sub-units, for interconnecting said first and second sub-units.

12. The welding unit according to claim 11, wherein said displacement cylinders have longitudinal axes, said clamping cylinders have longitudinal axes, and said longitudinal axes of said displacement cylinders and of said clamping cylinders are disposed approximately in a common plane.

13. The welding unit according to claim 12, wherein said clamping jaws are located to permit the rails for welding to be clamped with a neutral axis lying in said common plane.

14. The welding unit according to claim 11, wherein each of said sub-units has a clamping body underneath said unit guides, and a plurality of said clamping cylinders are integrated into said clamping bodies side by side.

15. The welding unit according to claim 11, wherein said sub-units have lateral outer surfaces, and said displacement cylinders are flange-mounted to said lateral outer surfaces.

16. The welding unit according to claim 11, wherein said unit guides include three unit guides disposed offset relative to one another.

17. The welding unit according to claim 16, wherein said unit guides are sliding tubes.

18. The welding unit according to claim 16, wherein said unit guides include two outer unit guides disposed side by side and a central unit guide disposed upwardly offset from said two outer unit guides.

19. The welding unit according to claim 11, which further comprises a transverse connecting part, said first sub-unit being disposed between said second sub-unit and said transverse connecting part, and said unit guides being rigidly connected to said second sub-unit and to said transverse connecting part.

20. The welding unit according to claim 11, wherein each of said sub-units has a respective structurally identical basic body.

21. The welding unit according to claim 20, wherein said displacement cylinders have different lengths, and each of said basic bodies has a plurality of connecting points disposed side by side at two longitudinal sides for flange-mounting said displacement cylinders having different lengths.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be described below by way of example with reference to the accompanying drawings. There is shown in a schematic manner in:

[0018] FIG. 1 a welding unit in a side view

[0019] FIG. 2 a welding unit in a front view

[0020] FIG. 3 a welding unit in a first oblique view

[0021] FIG. 4 a welding unit in a second oblique view

DESCRIPTION OF THE EMBODIMENTS

[0022] In the welding unit 1 depicted in FIGS. 1 to 4, a first sub-unit 2 is displaceable relative to a second sub-unit 5 along unit guides 4 by means of displacement cylinders 3. The unit guides 4, arranged at the corner points of an isosceles triangle in cross-section, are rigidly connected at the ends to a transverse connecting part 6. At the opposite side to the transverse connecting part 6, the unit guides 4 are rigidly connected to the second sub-unit 5. The displaceable first sub-unit 2 is arranged there between. In this way, the unit guides 4 and the connections at the ends form a rigid guide system.

[0023] Each sub-unit 2, 5 comprises a structurally identical basic body 7 that is designed, for example, as a welded structure. In the embodiment shown, the unit guides 4 comprise three sliding tubes. Two lower sliding tubes are arranged symmetrically with respect to a vertical symmetry surface 8. An upper sliding tube is arranged centrally above the former, so that the longitudinal axis of the sliding tube lies in the symmetry surface 8. Arranged in the basic body 7 of the first sub-unit 2 are slide bushings which slide on the sliding tubes. The sliding tubes are clamped tightly in the basic body 7 of the second sub-unit 5.

[0024] Below the unit guides 4 at both sides of a free space 9, each sub-unit 2, 5 has a respective clamping body 10. Arranged side by side in the clamping body 10 in each case are three inner cylinders in which pistons having piston rods are guided. In this manner, each clamping body 10 comprises three hydraulically coupled clamping cylinders 11, the piston rods of which are connected at the ends to a common clamping jaw 12. At the outer surfaces of the respective clamping body 10, the clamping cylinders 11 are closed off by means of cylinder covers 13.

[0025] In the free space 9 between the clamping bodies 10, rails 14 to be welded are received and clamped tightly. Specifically, a hydraulic actuation of the clamping cylinders 11 takes place during operation, as a result of which the clamping jaws 12 are pressed to the rails 14 to be welded to one another.

[0026] The displacement cylinders 3 are flange-connected at both sides to lateral outside surfaces of the sub-units 2, 5. In this, a cylinder body 15 of the respective displacement cylinder 3 is connected to the one sub-unit 2, and a piston rod 16 is connected to the other sub-unit 5. Favourably, connecting points 17 for the displacement cylinders 3 are arranged in the area between two clamping cylinders 11 of the respective clamping body 10. In this way, longitudinal axes of the displacement cylinders 3 and longitudinal axes of the clamping cylinders 11 are arranged approximately in a common plane 18. The object is the avoidance of bending moments caused by vertically spaced force axes.

[0027] For the purpose of using displacement cylinders 3 of different lengths, it is expedient if each clamping body 10 has two connecting points 17 between the three clamping cylinders 11. Then, in order to muster greater displacement forces, longer displacement cylinders 3 having several pressure chambers can be flange-connected to the connecting points 17 that are distanced furthest from one another.

[0028] As a result of the structural separation of the clamping cylinder arrangement and the guide system, no pulling forces are introduced into the guide system during a welding operation. Only the weight force of the welding unit and of the rails 14 to be welded as well as rail tension forces in vertical direction are acting on the guide system.

[0029] A shearing device for removing a welding bead is provided between the two sub-units 2, 5. A lifting device for lifting the rails is fastened to each outer front surface of the two sub-units 2, 5.

[0030] In preparation of the welding operation, both rails 14 are lifted from the sleepers laying thereunder by means of the lifting devices and are pressed against stop elements. Subsequently, the clamping cylinders 11 are actuated in order to press the clamping jaws to a rail web of the respective rail 14 with a high clamping force (1600 kN, for example). The clamping jaws 12 are connected to a secondary electric circuit of the welding unit 1 and cause a transmission of current to the rails 14. Alternatively, separate electric electrodes may also be pressed to the rails 14.

[0031] To initiate a welding procedure, the sub-units 2, 5 together with the gripped rails 14 are moved towards one another with a pulling force by actuation of the displacement drives 3. In this, up to 1500 kN are achieved in the course of a so-called closure welding. As soon as the spacing of the two rail ends as required for the welding has been achieved, the supply of electric current is started.

[0032] In case that the ambient temperature is above the neutral temperature, it is also possible during a closure welding to initially move the rails 14 apart from one another—by corresponding actuation of the two displacement drives 3—in order to produce a welding gap.