Tamping tine for a tamping machine

Abstract

The invention relates to a tamping tine (1) for a tamping machine for tamping sleepers (3) of a track that are mounted in a track ballast bed (2), comprising a tine shaft (5) which, with respect to an intended, approximately vertical orientation, has a lower end on which there is arranged a tine plate (6) which projects beyond the tine shaft (5) at least on one side and comprises an upper cover surface (11). As a result of an inclination of the upper cover surface (11) between the tine shaft (5) and a plate side surface (9), the tine plate (6) has a plate upper edge (12) for displacing ballast stones (14) during an upward movement (13). The last phase of a tamping cycle, namely pulling the tamping tine (1) out of the track ballast bed (2), can thus be carried out in an optimized manner.

Description

[0001] 1

[0002] Darning pick for a darning machine

[0003] The invention relates to a tamping pick for a tamping machine for tamping sleepers of a track laid in a track ballast bed, with a pick shaft which, in relation to an intended, approximately vertical orientation, has a lower end on which a pick plate is arranged which projects beyond the pick shaft at least on one side and comprises an upper cover surface.

[0004] For example, a generic darning pick is known from EP 1 329 554 Al. A pick plate is arranged at the lower end of a pick shaft. This pick plate has a front and a back surface. When the darning pick is oriented vertically, the front surface of the plate is approximately vertical. The back surface slopes upwards and merges into the pick shaft. At the lower free end, the front and back surfaces of the plate form a bottom edge. This bottom edge, like the front and back surfaces, is covered with carbide plates.

[0005] During a tamping cycle, the vibrating tamping pick is inserted into the track ballast. Initially, the lower edge of the pick makes contact with the ballast surface and displaces ballast grains to the side. Once a predetermined depth is reached, the front of the pick is moved against the ballast grains. In this way, the ballast grains captured by the tamping pick are pushed under the sleeper being tamped. Subsequently, the vibration compacts the ballast structure, creating a secure and lasting support for the sleeper. In the final phase of the tamping cycle, the tamping pick is withdrawn from the track ballast.

[0006] The invention is based on the objective of improving a tamping pick of the type mentioned above in such a way that optimal gravel treatment takes place in every phase of a tamping cycle.

[0007] This problem is solved by the features of independent claim 1. Dependent claims specify advantageous embodiments of the invention.

[0008] According to the invention, the tamping pick has a plate edge, created by an inclination of the upper surface between the pick shaft and a plate side, for displacing ballast grains during an upward movement. This optimizes the final phase of the tamping cycle, namely the withdrawal of the tamping pick from the track ballast bed. During the withdrawal process, ballast grains are deflected laterally by means of the plate edge. During this displacement process, the ballast grains largely remain in their position within the ballast structure. In contrast, with conventional tamping picks without a plate edge, ballast grains are carried upwards during the withdrawal process. These ballast grains are then missing from the ballast structure and can be thrown onto the sleeper surfaces or the rail surfaces. Such ballast grains are disruptive to train traffic, particularly due to the dangerous risk of ballast flying on high-speed lines.Furthermore, the missing gravel grains in the gravel structure weaken the lateral displacement resistance of the tamped 3rd

[0009] Thresholds. These disadvantages are avoided with the tamping pick according to the invention.

[0010] Advantageously, the top edge of the pick slab transitions into the pick shaft with a rounded edge. This ensures that even gravel grains lying close to the pick shaft are displaced by the top edge of the pick during the pulling process.

[0011] This design is particularly effective when the rounding has a radius of at least 20%, and especially at least 40%, of the shaft width at the lower end of the pick shaft. The large rounding prevents gravel grains from becoming wedged between the lower end of the pick shaft and other gravel grains.

[0012] In a further improvement, each upper surface of the pickaxe plate forms an angle of inclination of at least 30°, and in particular at least 45°, with a horizontal plane. This results in an acute angle in the cross-section of the plate's upper edge, which facilitates the displacement of the gravel grains during the extraction process.

[0013] The displacement of the gravel grains during the extraction process is further optimized by a sloping profile of the slab's top edge from the pick shaft to the corresponding slab side. The resulting inclination of the slab's top edge leads to additional lateral displacement of the gravel grains.

[0014] Advantageously, the upper edge of the plate runs at a downward angle of at least 10°, and in particular at least 20°, relative to a horizontal plane. This achieves the desired effect without impairing the effective contact area of ​​the pick plate during the setting process.

[0015] An improvement in the service life of the tamping pick is achieved by rounding the top edge of the plate, particularly with a radius of curvature in a range between 0.5 and 3 millimeters, and preferably in a range between 1 and 2 millimeters. This rounding reduces wear on the top edge of the plate, while maintaining the desired effect, namely the displacement of the ballast grains during the withdrawal of the tamping pick from the track ballast bed.

[0016] In a preferred embodiment, the upper edge of the plate is formed by a front upper surface, which abuts a front plate, and a rear upper surface, which connects to a rear plate. The front and rear upper surfaces have, in particular, an approximately equal inclination to a horizontal plane, resulting in a particularly robust cross-section of the pick-shaped plate. The displacement force acting on the individual gravel grain results from the respective inclination.

[0017] In another preferred variant, the upper edge of the plate is formed by the associated upper cover surface and a plate front or a plate back. The cross-sectional angle of the plate's upper edge is essentially determined by the inclination of one of the upper cover surfaces. This inclination determines the resulting displacement force that acts on the individual ballast grains during the withdrawal of the tamping pick from the track ballast bed. 5

[0018] Preferably, the pickaxe plate projects beyond the pickaxe shaft on both sides, with the upper edge of the plate formed on each side. In particular, the tamping pickaxe is symmetrically constructed with respect to a vertical plane. This results in a uniform load distribution on the tamping pickaxe during a tamping operation.

[0019] The invention is explained below by way of example with reference to the accompanying figures. These show, in schematic representation:

[0020] Fig. 1 Pulling process opposite

[0021] Darning pick;

[0022] Fig. 2 Front view of a darning pick, whose

[0023] The pick plate protrudes on one side beyond the pick shaft;

[0024] Fig. 3 Front view of a darning pick, the pick plate of which projects beyond the pick shaft on both sides;

[0025] Fig. 4 Side view of a darning pick with a pick plate in a first embodiment variant;

[0026] Fig. 5 Enlargement of the pickle plate according to Fig. 4;

[0027] Fig. 6 Side view of a pickaxe plate in a second design variant.

[0028] A tamping pick 1 of this type is used for tamping sleepers 3 embedded in a track ballast bed 2. Typically, tamping picks 1 opposite each sleeper 3 to be tamped are arranged in a tamping unit of a track-mounted tamping machine. In Fig. 1, tamping pick holders 4 of the tamping unit are indicated. 24008

[0029] 6

[0030] In the respective darning pick holder 4, a receiving section of a pick shaft 5 of the associated darning pick 1 is attached. The pick shaft 5 protruding from the respective darning pick holder 4 is, in its intended starting position, oriented approximately vertically downwards, as can be seen in Fig. 1 in the uppermost position of the two darning picks 1.

[0031] At the lower end of the pickaxe shaft 5, each pickaxe 1 has a pickaxe plate 6 oriented transversely to a direction of insertion. Between the receiving section and the pickaxe plate 6, the pickaxe shaft 5 tapers downwards. A front plate 7 and a back plate 8 are connected by two plate side surfaces 9 and bounded at the bottom by a plate lower edge 10. At the top, in an area where the pickaxe plate 6 projects laterally beyond the pickaxe shaft 5, a cover surface 11 of the pickaxe plate 6 is formed. In Fig. 2, the pickaxe plate 6 projects beyond the pickaxe shaft 5 only on one side. Another variant, in which the pickaxe plate 6 projects beyond the pickaxe shaft 5 on both sides, is shown in Fig. 3.

[0032] According to the invention, the respective upper cover surface 11 has an inclination, whereby a plate top edge 12 is formed between the pick shaft 5 and the associated plate side surface 9. The respective plate top edge 12 is shown with a thick line in Figures 2-6 and causes a displacement of ballast grains 14 of the track ballast bed 2 during an upward movement 13 of the tamping pick 1.

[0033] A tamping process is usually divided into several phases. In a first phase, the tamping unit is loaded with the 24008

[0034] 7

[0035] Tamping picks 1 are positioned over the sleeper bays on both sides of the sleeper 3 to be tamped. During a subsequent downward movement, the tamping picks 1, subjected to vibration, penetrate the track ballast 2, with the lower edges 10 of the picks first contacting a ballast surface 15. The downward movement continues until the tamping picks 1 reach a predetermined penetration depth. At this penetration depth, the upper edges 12 of the plates are located below the sleeper 3 to be tamped.

[0036] During a tamping operation that begins shortly before or upon reaching the predetermined immersion depth, the tamping picks 1 are moved towards each other, while the vibration is maintained at a reduced frequency of 35 Hz. The pick plates 6, with their front faces 7, push ballast grains 14 under the sleeper 3. In this way, a cavity created under the sleeper 3 by lifting the track is filled. After this filling, the vibrating front faces 7 continue to exert pressure on the ballast grains 14, resulting in sustained compaction of the ballast structure.

[0037] In a final phase of the tamping process, the tamping picks 1 are withdrawn from the track ballast bed 2. This withdrawal process is shown in several stages in Fig. 1. Starting from the lowest position of the tamping picks 1, a coordinated upward movement 13 and return movement of the tamping picks 1 takes place. The respective tamping pick 1 is preferably moved along a trajectory 16 formed by the centroids of the cross-sections of the pick shaft 5. In this way, the previously produced compacted ballast layer for the sleeper 3 is not affected.

[0038] The upper edges 12 of the pickaxe plates 6 according to the invention also prevent the gravel grains 14 from being moved upwards during the extraction process. The inclined upper surfaces 11 of the pickaxe plates 6 cause the gravel grains 14 to be displaced forwards and / or backwards and / or to the side.

[0039] Exemplary tamping picks 1 are shown in Figures 2-6, where in each figure only a lower section of the pick shaft 5 and the pick plate 6 are depicted. In Figures 2 and 3, the lateral displacement of the gravel grains 14 is indicated by arrows. The respective upper edge 12 of the plate preferably slopes downwards from the pick shaft 5 to the associated plate side surface 9. In particular, an angle α between a horizontal plane 17 and the respective upper edge 12 of the plate lies in a range between 10° and 30°, for example, at 20°. Furthermore, the upper edge 12 of the plate advantageously transitions into the pick shaft 5 with a rounded section, this rounded section having a radius λr of at least 20%, for example, 30%, of a shaft width b at the lower end of the pick shaft 5.

[0040] A displacement of the ballast grains 14 forwards and backwards is indicated by arrows in Fig. 4. This effect occurs during the upward movement 13 of the tamping pick 1 through the inclined upper cover surfaces 11. An enlargement of this embodiment is shown in Fig. 5. Here, a front upper cover surface 11 adjoins the front surface 7 of the plate, and a rear upper cover surface 11 adjoins the back surface 8 of the plate.

[0041] The front upper surface 11 forms a first angle of inclination β1 with the horizontal plane 17, and the rear upper surface 11 forms a second angle of inclination β2 with the horizontal plane 17. Preferably, the respective angles of inclination β1 and β2 are in a range between 30° and 75°, particularly between 45° and 60°. Preferably, the resulting cross-sectional angle y of the upper edge of the plate 12 is an acute angle, so that the ballast grains 14 are effectively displaced forwards and backwards during the upward movement 13 and are not carried upwards along with the ballast.

[0042] An improvement in the wear resistance of the plate's top edge 12 is achieved by rounding it with a radius r2 in a range between 0.5 millimeters and 3 millimeters. For example, this radius r2 is equal to 1.5 millimeters.

[0043] An alternative variant of the tamping pick plate 6 is shown in Fig. 6. Here, a single inclined upper cover surface 11, together with the front surface 7 of the plate, forms the plate's upper edge 12. The cover surface 11 forms an angle of inclination β with the horizontal plane 17, this angle of inclination preferably being in a range between 25° and 65°, for example, 45°. The nearly vertical orientation of the pick's front surface 7 thus results in a significantly acute cross-sectional angle y of the plate's upper edge 12.

[0044] Figures 4 to 6 show that the back surface 8 of the plate extends inclined backwards from the lower edge 10 of the plate in a lower section, with this inclined surface transitioning into the pick shaft 5. In 24008

[0045] In the upper section 10, the lateral areas of the back of the plate 8, projecting over the pick shaft 5, run approximately parallel to the front of the plate 7. Carbide plates 18 are arranged on the lower edge 10 of the plate, the front of the plate 7, and the back of the plate 8. Additionally, carbide bolts 19 are arranged in the side surfaces 9 of the plate, thus extending the service life of the pick plate 6. The respective top surface 11 and the respective upper edge of the plate are also preferably

[0046] 12 coated with hard metal plates 18. In this way, the stability of the packing pick 1 is increased in all phases of the packing process.

Claims

11 Patent claims 1. Tamping pick (1) for a tamping machine for tamping sleepers (3) of a track laid in a track ballast bed (2), with a pick shaft (5) which, in relation to an intended, approximately vertical orientation, has a lower end on which a pick plate (6) is arranged, which projects at least on one side over the pick shaft (5) and comprises an upper cover surface (11), characterized in that the pick plate (6) has a plate top edge (12) for displacing ballast grains (14) during an upward movement (13) by means of an inclination of the upper cover surface (11) between the pick shaft (5) and a plate side surface (9).

2. Dotting pick (1) according to claim 1, characterized in that the upper edge of the plate (12) transitions into the pick shaft (5) with a rounded shape.

3. Darning pick (1) according to claim 2, characterized in that the rounding has a radius (rl) of at least 20%, in particular of at least 40% of a shaft width (b) at the lower end of the pick shaft (5).

4. Tamping pick (1) according to one of claims 1 to 3, characterized in that each upper cover surface (11) encloses an angle of inclination (ß, ß1, ß2 ) of at least 30°, in particular of at least 45°, with a horizontal plane (17).

5. Tamping pick (1) according to one of claims 1 to 4, characterized in that the upper edge of the plate (12) from the pick shaft (5) to the associated plate side surface (9) slopes downwards.

6. Stuffing pick (1) according to claim 5, characterized in that the upper edge of the plate (12) slopes downwards at an angle (a) of at least 10°, in particular at least 20°, relative to a horizontal plane (17).

7. Dowel pick (1) according to one of claims 1 to 6, characterized in that the upper edge of the plate (12) is rounded, in particular with a radius of curvature (r2) in a range between 0.5 and 3 millimeters, preferably in a range between 1 and 2 millimeters.

8. Stuffing pick (1) according to one of claims 1 to 7, characterized in that the upper edge of the plate (12) is formed by a front upper cover surface (11) which adjoins a front plate (7) and a rear upper cover surface (11) which adjoins a rear plate (8).

9. Stuffing pick (1) according to one of claims 1 to 7, characterized in that the upper edge of the plate (12) is formed by the associated upper cover surface (11) and a plate front (7) or a plate back (8).

10. Darning pick (1) according to one of claims 1 to 9, characterized in that the pick plate (6) projects over the pick shaft (5) on both sides and that the upper edge of the plate (12) is formed on each side.

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