Rammer for ramming sleepers for railway tracks

Abstract

A tamper (1) for tamping sleepers of a track (2) has a machine frame (4) which extends in the longitudinal direction of the tamper and which can be moved on two rail running mechanisms (9), and a work carriage (3) which is arranged between the rail running mechanisms (9) and which can be moved on the track (2) by means of a running mechanism (10), the work carriage being connected to the machine frame (14) by means of a longitudinal guide (18) of the work carriage, and having a track-lifting and correcting unit (7). In order to advantageously achieve a positioning condition, it is proposed that the work carriage (3) is directly connected to the machine frame (4) by means of a linear drive (4) with a position detector, wherein the linear drive (4) accelerates and decelerates the work carriage (3) between the rail running mechanisms (9) in a predetermined displacement range (A) in order to maintain a predetermined displacement amount, wherein two hydraulic cylinders (4) are provided, one of which pushes the work carriage (3) and the other of which pulls the work carriage when the work carriage is moved between the rail running mechanisms (9).

Description

Technical Field

[0001] This invention relates to a tamping machine for tamping sleepers in a track. The tamping machine has a mechanical frame extending longitudinally along the tamping machine and capable of running on two rail traveling mechanisms, and a working trolley or auxiliary device arranged between these rail traveling mechanisms and capable of running on the track via the traveling mechanisms. The working trolley is guided and connected to the mechanical frame via a working trolley longitudinal guide. Between the traveling mechanisms and the working trolley longitudinal guide, there are tamping units and track straightening units with adjustable height relative to the working trolley. The working trolley is directly connected to the mechanical frame via a linear drive device with a position detector. The linear drive device accelerates and decelerates the working trolley between the rail traveling mechanisms within a preset range of movement, thereby maintaining a preset amount of movement (sleeper spacing or sleeper boxes therein). Background Technology

[0002] This type of tamping machinery, such as that known in document DE 3409846 A1, continuously operates via a work trolley, referred to herein as the work trolley. The tamping machinery travels at a constant speed during operation, while the integrated tamping work trolley moves discontinuously from the tamping area to the tamping area via the tamping unit, track lifting and straightening device, and measuring carriage, lifting and straightening the track and tamping the sleepers.

[0003] Such tamping machinery that moves continuously during operation is known, for example, by document US 6,705,232. A significant advantage of this type of tamping machinery is that the main machine, with its considerably larger mass, does not need to stop and then accelerate again after each sleeper tamping. Thus, the operating speed of the machine is increased relative to machines performing periodic operations, and the acceleration acting on the machine is also reduced. The periodic forward movement from sleeper area to sleeper area restricts the work trolley supporting the tamping unit, which is designed to be longitudinally movable relative to the main frame of the machinery. Such machinery is also known by document AT 401943 B.

[0004] If the track geometry exceeds the comfort or safety limits determined by the train's orientation, track tamping is planned and implemented promptly. Currently, track superstructure engineering machinery is used in most cases to eliminate and correct track geometry faults.

[0005] During maintenance work, the tamping unit is fixed in position on the track. This is achieved by a tamping tool, referred to herein as a tamping pick, which is inserted into the ballast next to the sleeper and compacts the ballast under the sleeper through a linear closing motion, with the compaction vibration superimposed on the closing motion.

[0006] Tamping machinery specifically designed for tamping turnouts (featuring detachable tamping units, i.e., split-type units, additional lifting devices for branch lines, and rotatable tampers) and preferred constructions for tamping track sections are provided. These tamping machines are known to operate periodically but also continuously. In addition, monosleeper tamping machines and multisleeper tamping machines exist. Multisleeper tamping machines tampe multiple sleepers per operation cycle. However, they can also be configured to tampe only monosleepers.

[0007] In known solutions, the trolley frame is mounted on a traveling mechanism connected to braking and drive mechanisms acting on the wheels. A drawback of this method is that the work is not performed without delay, but rather involves periods of inactivity. Like braking, the drive depends on the friction between the wheel-rail and the material on the traveling mechanism. If the driving or braking force is too high, the drive wheels may slip or lock. Slippage results in excessive wear on the rails and significant time loss. Locking causes the trolley to slip beyond the planned feed. Subsequently, the trolley must be retracted to allow the tamping pick to be inserted into the sleeper box between the sleepers. This also results in time loss and interrupts the continuity of the work. Continuous tamping machines operate with fixed tamping times. When the tamping time varies, the forward speed of the main machine must always match the changing tamping time, or even stop if the trolley exhausts its adjustment stroke. A method is known from document AT515801, in which a favorable tamping time is automatically determined and preset by the machine itself. The method described in document AT515801 demonstrates practical effectiveness, resulting in a very long, maintainable track position and thus achieving significant economic advantages. However, the application of this method does not involve predictable variations in tamping time, which even makes continuous tamping difficult or impossible.

[0008] Tamping operations exhibit high-cost operating conditions, which means the tamping machinery must have the highest possible operating power and the highest possible maintainability of the corrected track position.

[0009] The drive unit of the walking mechanism consists of energy, regulation circuit, transmission mechanism and drive motor, and is very expensive and costly.

[0010] As known from document EP 1387003 B1, the driving mechanism of the work trolley can be supported by an accelerator cylinder. While this partially compensates for the starting delay of the drive mechanism, the accelerator cylinder does not participate in the precise positioning of the work trolley. Nor does the accelerator cylinder participate in braking the work trolley. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to avoid the aforementioned disadvantages and to achieve precise and rapid position adjustment of the work trolley.

[0012] The technical problem is solved according to the present invention as follows: two hydraulic cylinders are provided, and when the working trolley moves between the rail traveling mechanisms, one hydraulic cylinder pushes the working trolley and the other hydraulic cylinder pulls or brakes the working trolley.

[0013] According to the invention, different tamping times are automatically compensated for by a linear drive device through matching the starting and braking accelerations. The trolley advances rapidly for longer tamping times and slows down for shorter tamping times. Two or more hydraulic cylinders can also be used, one part pushing the trolley between the rail travel mechanisms during movement, and another part pulling or braking the trolley when it reaches the destination position. Thus, the same effect can be achieved as with the use of double-bar hydraulic cylinders. Therefore, continuous operation can be achieved even with different tamping times by adjusting acceleration and delay. Preferably, at least one cylinder is provided at the front and rear of the trolley along the working direction. Particularly advantageously, the rear cylinder is a push cylinder that pushes the trolley forward along the working direction, and the front cylinder is a brake cylinder that precisely brakes the trolley to the desired destination position. Both cylinders are equipped with stroke sensors for controlling and adjusting the position.

[0014] This invention enables higher starting and braking acceleration for the work trolley because the pushing hydraulic cylinder can achieve a larger feed force, and the pulling brake cylinder can achieve both pulling and braking forces. This pulling and braking force is necessary if the work trolley needs to be strongly pushed forward in the working direction and then strongly braked at the working position. Furthermore, a large oil reservoir can be omitted, as only the grease required for drive needs to be pumped back and forth between the two cylinders.

[0015] Another important advantage of the present invention is that the driving and braking devices for the working trolley traveling mechanism can be eliminated, and the working trolley can be positioned very accurately between two rail traveling mechanisms. Furthermore, the position can be quickly corrected within the track in case of deviation, because compared with the driving and braking devices on the traveling mechanism, for example by slipping between the wheels and the rails, only a very small rest time and action delay are provided.

[0016] The trolley is fixedly connected to the mechanical frame of the tamping machine via at least two linear drive units. Each linear drive unit is embedded at one end in the mechanical frame and at the other end in the trolley. The linear drive unit can be designed as a hydraulic cylinder with a position sensor. This linear drive unit is used both to accelerate the trolley and to decelerate it when positioning it between the rail travel mechanisms of the tamping machine. The starting and braking inclinations are precisely preset via proportional control valves or servo valves and corresponding regulating electronics. The trolley's mass is only 10-15% of the main machine's mass, so the operator on the continuously moving main machine experiences relatively small impacts during starting and braking. Furthermore, reaction forces (acceleration momentum reaction and braking momentum reaction) can be selected by choosing the appropriate acceleration and braking inclinations. The linear drive unit accelerates and decelerates the trolley within a preset range of movement between the rail travel mechanisms, thereby maintaining a preset amount of movement. Based on the cycle time of the tamping unit and the track straightening unit, the travel speed of the tamping machinery, and the travel range of the trolley, a preset amount of movement is maintained. This amount of movement is within the allowable range and represents the amount of movement of the trolley relative to the mechanical frame along the track. Additionally, a travel drive and braking device can be constructed to provide support. This has the advantage of allowing for the redundancy and support of the hydraulic cylinders, which can be designed in a compact manner. Two linear drive units can also be used, one pulling forward in the working direction and the other squeezing and applying force in the opposite direction during braking. This has the advantage of applying the same force during acceleration and braking. The hydraulic cylinders, as linear drive units, have different force applications based on the piston surface and the annular surface, respectively, according to the operating direction.

[0017] A key advantage of this invention is the elimination of the braking devices for the travel drive and the trolley drive, allowing for particularly precise positioning of the trolley between the two rail travel mechanisms and rapid correction of any deviations. This is because, compared to the travel drive and braking devices on the travel mechanisms, there is significantly less stationary time and delay due to slippage between the wheels and rails. Furthermore, it is independent of wheel-rail friction values. For example, in autumn, the speed of the matching tamping machine must be adjusted based on the existing poor friction values ​​(due to leaves on the rails), thus reducing operating speed. This is avoided in the embodiments according to the invention. In single-sleeper tamping machines, the preset forward stroke is the sleeper spacing (typically 60 cm), or in multi-sleeper tamping machines, it is a corresponding multiple of the sleeper spacing. The advantage provided by the invention is that the automatic adjustment of acceleration and braking delays by the linear drive mechanism balances different tamping times and thereby reliably maintains continuous forward movement of the main machine. Overall, the operating speed of the tamping machine is increased by eliminating the stationary time of the trolley's travel drive. Another advantage of this invention is that it automatically adjusts the starting acceleration and braking acceleration when increasing or decreasing the constant forward speed of the tamping machine. This allows for even higher operating speeds.

[0018] The linear drive preferably includes at least two hydraulic cylinders, particularly double-rod hydraulic cylinders, with position detectors. In particular, an adjustment circuit may be provided, which, based on a particularly constant tamping machine travel speed, pre-determines the starting and braking accelerations of the trolley via the linear drive to achieve a preset permissible amount of movement. Attached Figure Description

[0019] In the appendix Figure 1 The technical solution of the present invention is illustrated in the accompanying drawings.

[0020] Figure 1 The diagram shows a side view of a continuously operating tamping machine 1, which includes a trolley 3 and a linear drive device 4.

[0021] Figure 2 Showing the travel time curve, and

[0022] Figure 3 Similarly, a travel time curve is shown. Detailed Implementation

[0023] The tamping machine 1 for tamping the sleepers of the track 2 includes a mechanical frame 14 and a working trolley 3. The mechanical frame is capable of running on two rail traveling mechanisms 9 and extends longitudinally along the tamping machine. The working trolley is arranged between the rail traveling mechanisms 9 and can run on the track 2 via a traveling mechanism 10. The working trolley is guidedly connected to the mechanical frame 14 via a working trolley longitudinal guide 18. The working trolley has a tamping unit 5 and a track straightening unit 7 with an adjustable height relative to the working trolley 3 between the traveling mechanism 10 and the working trolley longitudinal guide 18.

[0024] The trolley 3 is directly connected to the mechanical frame 14 via a linear drive device 4 with a position detector. The linear drive device 4 accelerates and decelerates the trolley 3 between the rail travel mechanism 9 within a preset movement range A, thereby maintaining a preset amount of movement.

[0025] Within the mechanical frame 14 of the machine, a longitudinally movable trolley 3 is mounted on a traveling mechanism 10. The trolley 3 is guided longitudinally within the mechanical frame 14 in the form of a unicycle, passing through the traveling mechanism at one end and a guide arm at the other end via a longitudinal guide 18. The machine 1, equipped with a tamping operation cabin 15, can travel on the track 2 via a bogie. The machine has track measuring systems 6, 11, and 12, integrated within the trolley 3, for adjusting the track straightening unit 7. A liftable tamping unit 5 is mounted on the trolley 3. This tamping unit can rotate by an angle α around the height axis via a rotary gear ring 19 and can also move laterally via a moving device 20 positioned transversely to the working direction. The track straightening unit can move longitudinally along the track via a linear drive 8 connected to the trolley frame 13. The track straightening unit 7 is equipped with at least one lifting cylinder H and at least one straightening cylinder R.

[0026] The machine operates along the working direction AR. The work trolley 3 is capable of moving relative to the machine frame 14 within a range of motion A, the amount of movement related to the work (straightening and / or tamping, track bed quality) being within this range. The linear drive unit 4 has a particularly integrated travel measurement system, through which the work trolley 3 is guided within or under the machine frame 14, accelerates forward in the travel direction, and brakes again in a timely manner to accurately reach the required travel distance.

[0027] Figure 2 The graph depicts the journey *s* on the vertical axis and the time axis *t* on the horizontal axis. The tamping machine 1 maintains a constant forward speed *v*. M The travel-time curve of the work trolley 3 is shown by a straight line. st Corresponding tamping time, tT The stationary time of the corresponding drive unit, 'a' corresponds to the forward travel distance (sleeper spacing) and 't'... F Corresponding to the forward time. A stationary time t occurs at point ST. st’ The abnormal extension occurred because the forward travel of the trolley was exhausted, so the main machine had to stop for time t. Mst Furthermore, the movement of the work trolley 3 can only resume after it has moved forward.

[0028] Figure 3 The graph depicts the journey *s* on the vertical axis and the time axis *t* on the horizontal axis. The tamping machine 1 maintains a constant forward speed *v*. M The travel-time curve of the work trolley 3 is shown by a straight line. st1 The tamping time corresponding to the first tamping, and t F1 This corresponds to the advance time. Because the linear drive device according to the present invention does not have a rest time t... T Therefore, the time t available for forward movement F At a comparable forward velocity v M The second tamping may require a longer time. The starting acceleration and braking of the trolley 3 can be performed gently. The second tamping may require, for example, a longer time t. st2 Accordingly, the forward travel time t is shortened. F2 The starting and braking accelerations are automatically matched, with a greater acceleration. The third tamping requires time t. st3 With the corresponding set starting and braking accelerations, the forward travel time is t. F3 And so on. In this way, even if the tamping time is different, the tamping machine 1 can still operate at a constant speed.

Claims

1. A tamping machine (1) for tamping sleepers of a track (2), the tamping machine having a mechanical frame (14) extending longitudinally along the tamping machine and capable of running on two rail traveling mechanisms (9), and a working trolley (3) arranged between these rail traveling mechanisms (9) and capable of running on the track (2) via a traveling mechanism (10), the working trolley being guided and connected to the mechanical frame (14) via a working trolley longitudinal guide (18), and having a tamping unit (5) and a track straightening unit (7) with adjustable height relative to the working trolley (3) between the traveling mechanism (10) and the working trolley longitudinal guide (18), wherein, The trolley (3) is directly connected to the mechanical frame (14) via a linear drive device (4) with a position detector. The linear drive device (4) causes the trolley (3) to accelerate and decelerate between the rail travel mechanism (9) within a preset movement range (A) to maintain a preset movement amount. The linear drive device (4) consists of two hydraulic cylinders with position detectors. When the trolley moves between the rail travel mechanism (9), one hydraulic cylinder pushes the trolley (3) and the other hydraulic cylinder pulls the trolley.

2. The tamping machine according to claim 1, characterized in that, The linear drive device (4) is a dual-bar hydraulic cylinder with a position detector.

3. The tamping machine according to claim 1 or 2, characterized in that, An adjustment circuit is provided, which, based on the constant tamping machine travel speed, predetermines the starting acceleration and braking acceleration of the working trolley (3) using the linear drive device (4) in order to achieve a preset allowable amount of movement.

4. The tamping machine according to claim 1, characterized in that, An adjustment loop is provided, which adjusts the tamping time (t) Fi Under different conditions, the starting acceleration and braking acceleration of the working trolley (3) are predetermined by the linear drive device (4) based on the constant tamping machine travel speed, so as to achieve the preset allowable amount of movement.

5. The tamping machine according to claim 1, characterized in that, In addition to the linear drive device (4), the traveling mechanism (10) of the working trolley (3) is also equipped with a travel drive device (16).

6. The tamping machine according to claim 1, characterized in that, In addition to the linear drive device (4), the traveling mechanism (10) of the working trolley (3) is also equipped with a braking device (17).

7. The tamping machine according to claim 1, characterized in that, The rear hydraulic cylinder is a push cylinder, which pushes the work trolley (3) forward along the working direction, and the front hydraulic cylinder is a brake cylinder, which brakes the work trolley to the position it should reach.

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