JP5984644B2 - Method and apparatus for adjusting the amplitude of a tamping beam of a road finishing device, and a tamping beam and a road finishing device - Google Patents

Description

  The present invention is for adjusting the amplitude of a tamping beam of a road finishing device, comprising a rotary drive for the tamping beam, wherein the tamping beam performs an oscillating vertical motion having a top dead center and a bottom dead center. It relates to a method and an apparatus.

  As is conventionally known, a road finishing device is used to form a road surface in a planar shape. In this case, the paving material, for example asphalt, is distributed to the desired paving width in front of the paving screed which pulls the paving material to the desired paving thickness and smoothes the surface. A tamping beam, also called a tamping device, can be placed in front of the paving screed, which solidifies the paving material by tamping vertical movement and supports the flow of material to be paved under the paving screed. For this purpose, the tamping beam is connected via a push rod to a rotary drive, during which the oscillating vertical motion specified as the amplitude or stroke of the tamping beam is created. It is. In the known tamping beam, the drive device comprises a crankshaft, for example.

  Usually, the hardening by the tamping beam of the road finishing device does not replace the subsequent hardening by the roller. This is because in the case of hardening with a tamping beam, there is also a pre-stamping story. However, in order to achieve a better pavement surface, a high degree of pre-stamping with a tamping beam is advantageous. It is also particularly efficient because it takes place at the highest possible temperature of the paving material and minimizes the risk of material sliding during subsequent rolling compaction. Furthermore, it is possible to reduce the roller compaction force.

  The known tamping beam has a flat base surface with a width of about 2 to 3 cm, and its front approach angle is about 60 degrees. The reason why such geometry is selected is that it is possible to pave all of the pavement used and the normal layer thickness without any damage to the pavement or pavement equipment. Because there is. This involves a compromise that does not have an equally advantageous effect on all layer thicknesses and materials. For example, in a tamped beam with a large layer thickness and a small base area, the material is mainly pushed forward, with only a slight compression (consolidation) in the vertical direction. In this case, it rests on the material already present below the paving screed, thereby facilitating to some extent the flow of another material below the paving screed. With a relatively large base area tamped beam, it is certainly possible to achieve increased vertical compression (consolidation) with thick layers, but with thin layers on the order of 2 cm, the material no longer flows forward. There is a risk of granular fragmentation. The vertical reaction force of the relatively wide tamping beam lifts the paving screed associated with each stroke, creating waves on the surface of the paving material.

  It is of course known to manually adjust the vibration amplitude of the tamping beam. For this purpose, however, this requires high assembly costs, since it must first allow the operator access to the adjustment device. Usually, at least a portion of the machine cladding must be removed. This means that the operation of the road finishing device has to be interrupted, which has an adverse effect on the quality of the material layer being paved.

  A general device for a tamping beam is known from DE 102006046250A1. The tamping beam is attached to a lever arm having a predetermined effective length, and this arm is driven by an eccentric drive device. To adjust the stroke of the tamping beam, the effective length of the lever arm relative to the eccentric drive is varied while maintaining the effective length of the lever arm relative to the tamping beam. This ensures that the bottom dead center of the tamping beam does not change regardless of the adjusted stroke. Another general device for adjusting the stroke of the tamping beam is known in DE 1459670A and EP 2325392 A2. All these devices have the common feature that the top dead center and bottom dead center of the tamping beam are defined invariably by the eccentricity of the eccentric drive. The eccentric drive determines the downward movement to the bottom dead center of the tamping beam and the retreat movement to the top dead center of the tamping beam.

DE102006046250A1 DE1459670A EP2325392A2

  Accordingly, it is an object of the present invention to provide a method and apparatus of the type described at the outset that allows simple amplitude adjustment.

  The challenge is to drive the tamping beam toward the bottom dead center, disconnect it from it, and retract it toward the top dead center to create vertical vibrations, and the length of the retract path can be adjusted arbitrarily Achieved by a top dead center configuration that can be adjusted by various regulations.

  The concept underlying the present invention is therefore that the deflection of the tamping beam is not proportional to the deflection of the tamping beam drive.

  According to another preferred development, energy is stored during driving of the tamping beam and this energy is used for the retraction movement of the tamping beam. Thereby, the tamping beam is positively displaced only by the downward driving force.

  In a particularly advantageous configuration, the drive is configured as a cam drive or eccentric shaft with a constant amplitude to which the tamping beam is operatively connected for displacement to bottom dead center, where the tamping beam is at top dead center. A retraction device is provided which is operatively connected for displacement to the position and independent of the amplitude of the cam device, and an arbitrarily vertically adjustable stop is provided to fix the top dead center.

  Other suitable developments are described in the dependent claims.

  The present invention is advantageous in that the base surface of the tamping beam at bottom dead center is maintained in the plane of the base region of the pavement screed and independent of the adjusted stroke when the amplitude is changed. Therefore, compared with the conventional tamping beam, the width of the base surface of the tamping beam can be expanded to such an extent that it can be sufficiently solidified even with a large thickness. When a thin layer is hardened, it can be easily adjusted to an appropriate amplitude. Therefore, it is not necessary to align again after changing the amplitude. There is only one component that has to be adjusted to change the amplitude, which can be done constructively by relatively simple means and the camshaft stroke can be kept constant. The amplitude can be changed quickly. Another advantage is that the amplitude can be kept essentially small, thereby reducing wear and working noise.

  According to yet another preferred development of the invention, the frequency of the amplitude vibration is set depending on the top dead center. This has the advantage that the frequency varies depending on the amplitude of the tamping beam and that frequency is also adapted to the pavement layer thickness.

  Furthermore, it is advantageous to keep the impact distance of the tamping beam constant, i.e. to increase the frequency in proportion to the paving speed. Here, the collision distance is understood as a distance between two dead points during forward movement of the road finishing device.

  In principle, it is possible to provide a gradual adjustment of the stop. However, the continuous adjustment of the stop (stop) is particularly advantageous, which makes it possible to change the amplitude steplessly. In this way, the optimum hardening for each layer thickness and each material can be precisely adjusted without any subsequent damage to the surface or the device.

  According to another preferred development of the invention, the stop is operatively connected to the push rod. This has the advantage that the adjustment of the stop can be made parallel or concentric with the push rod.

  By providing an adjusting device for the stop which can be operated from the driver's seat of the road finishing device, amplitude adjustment without interruption of the operation is particularly ensured.

  For the adjustment, a drive device, preferably a mechanical, electric or hydraulic device can be used. Convenient is a mechanical adjustment device in which the stop is preferably configured as a linearly displaceable bushing guided by a push rod or chain and cooperating with a non-displaceable counterpiece attached to the push rod. .

  The adjustment of the bushing has an external screw guided by the internal screw on the housing side, and in the simplest case, the internal screw and the external screw are formed by a bushing composed of a control pin and a control curve for the control pin, respectively. In particular, it can be achieved simply. Preferably, the control pin is disposed on the bushing side, and the control curve is disposed on the housing side. This has the advantage that adjustment of the stop can be achieved simply by twisting the bushing around its axis.

  In a preferred alternative arrangement of the adjusting device, it comprises a spindle drive device by which the stop can be displaced parallel to the push rod.

  As a result, the amplitude adjustment can be done manually by the operator and he can proceed with the next observation and visual inspection or proceed according to the specifications regarding the pavement and the required layer thickness to obtain a good working result. It becomes possible. However, the present invention is particularly advantageous for automatic amplitude adjustment, since adjustment of the stop can be achieved relatively easily by a controlled or adjusted device, such as a motor or motor controller.

An optimally adjusted amplitude adjustment is obtained by using at least one of the following control variables measured by the sensor.
-Hydraulics of the tamping beam drive,
− Compression force of the tamping beam − Compression stress of the push rod of the tamping beam − Vertical movement of the pavement screed structure − Vertical acceleration of the pavement screed structure − Density as the vibration rate EVIB [MN / m ² ] especially behind the pavement screed And / or soil firmness

  These control variables can be advantageously combined with other parameters such as tamping beam vibration frequency, pavement screed progression, pavement layer thickness.

The invention will be further described with reference to the four embodiments schematically shown in the drawings.
FIG. 2 is a partially cut side view of a first device for adjusting the amplitude of a tamping beam. FIG. 6 is a partially cut side view of a second device for adjusting the amplitude of a tamping beam. FIG. 6 is a partially cut side view of a third device for adjusting the amplitude of a tamping beam. FIG. 7 is a partially cut side view of a fourth device for adjusting the amplitude of a tamping beam.

  1, 2 and 3, reference numeral 10 denotes a tamping beam of a road finishing device (not shown) mounted so as to be vertically displaceable so as to be able to carry out a vertical vibration with top dead center and bottom dead center. Show. This tamping beam 10 has a vertical push rod 11 with a head surface 12 located at the upper end. The push rod 11 is moved in one direction by the first driving device and is moved in the opposite direction by the second driving device separated from the first driving device. In the illustrated example, the first drive device is a cam drive device 13, which is located at the upper end, and an eccentric cam 14 attached to the shaft 30 with the tamping beam 10 operatively connected thereto. Is configured to slide and rotate on the head surface 12. Since the cam 14 is not rigidly or positively connected to the tamping beam 10, it is tamped only when moving towards the tamping beam 10, ie in the clockwise direction in the illustrated example. Only when moving toward the beam 10 can the driving force be transmitted. When moving away from the tamping beam 10, the cam driving device 13 does not transmit any driving force to the tamping beam 10.

  The second drive device is here configured as a compression spring 20 that is operatively connected to the tamping beam 10 so as to transmit the kinetic energy absorbed from the cam drive device to the tamping beam 10 with respect to the tamping beam 10. The retractor is a retractor. After the displacement by the first drive device, the second drive device, ie the compression spring 20, automatically retracts the tamping beam 10 to its start position. Accordingly, the second driving device can similarly transmit the driving force to the tamping beam 10 only in one direction, that is, in the retracting direction opposite to the direction of the driving force of the first driving device.

  The tamping beam 10 and the cam driving device 13 are disposed on the base frame 15 of the paving screed 16 of the road finishing device. The push rod 11 is guided to the friction bearing 18 and the screw bushing 19 on the base frame 15. The screw bushing 19 has an external thread 36 that cooperates with a complementary internal thread of the base frame 15. As a result, the position of the screw bushing 19 can be adjusted concentrically with respect to the base frame 15 and the push rod 11 by turning it. The paving creed 16 has a slide plate 17 whose base surface 24 is substantially flat and lies on the material to be paved. The tamping beam 10 is located in front of the slide plate 17 in the traveling direction of the road finishing device.

  The cam driving device 13 has a constant maximum amplitude A1 determined by the eccentricity of the cam 14. At the maximum amplitude A <b> 1 of the cam 14, the tamping beam 10 is deflected downward to a bottom dead center where the lower surface of the tamping beam 10 is flat with respect to the base surface 17 of the slide plate 17 of the pavement screed 16. This state is shown in the drawing. The cam drive device 13 drives the push rod only in the direction toward the bottom dead center.

  Driving toward the top dead center is achieved by a compression spring 20 which is pulled by the cam 14 during movement to the bottom dead center and is fatigue-resistant and configured as a settlement-free. The drive to the top dead center of the push rod 11 is separated from the drive to the bottom dead center. That is, the movement to the top dead center is independent of the cam drive device 13. The compression spring 20 is disposed between the base frame 15 and the collar 21 located on the push rod 11. As the cam 14 moves toward bottom dead center, it pushes the push rod 11 downward, pulling the compression spring 20 and storing energy during this process. During the movement away from the bottom dead center of the cam 14, the compression spring 21 is relaxed and the stored energy is released, so that the push rod 11 moves upward without driving the push rod 11 by the cam drive device 13. Is pushed.

  The top dead center is here arbitrarily adjusted by means of an adjustment device formed by a vertically adjustable stop 22. The stop forms an arbitrary limit that allows the length of the retract path of the push rod 11 to be adjusted. This restricts the upward movement of the push rod 11 without arbitrarily connecting the cam drive device 13 to the push rod 11 and without affecting the length of the retracting path of the push rod 11. .

  Since the retracting of the tamping beam 10 is separated from the cam drive device 13, the length of the evacuation path of the tamping beam 10 can be adjusted independently of the retracting path of the cam 14. If the length of the retracting path of the tamping beam 10 is adjusted to be shorter than the length of the retracting path of the cam 14, the cam 14 is arbitrarily operated on the tamping beam 10 with a corresponding delay when moving downward. Connected. Thus, in a range of angles, the cam 14 rotates freely, i.e. without moving the tamping beam 10 downward. The magnitude of this angular range depends on the adjusted length of the retract path of the tamping beam 10.

  In the illustrated example, the stop 22 is formed by the lower front surface of the screw bushing 19. A stop counterpiece (stop counterpiece) 25 of the push rod 11 is here formed by the upper front surface of the collar 21. A shock absorber for reducing the impact of the collar 21 on the stop 22 is provided, which in the illustrated embodiment is configured as a shock absorber 23 made of an impact absorbing material on the stop 22. Alternatively, a compression spring (not shown) may be provided between the stop portion 22 and the stop portion counter piece 25 as a shock absorber.

  Therefore, the tamping beam 10 is between a bottom dead center fixedly determined in advance by the amplitude A1 of the cam driving device 13 and a stop portion 22 that can be arbitrarily adjusted linearly along the push rod 11. Oscillating movement is performed, thereby creating an adjustable amplitude regulation. Since the bottom dead center does not change during amplitude adjustment, the bottom surface of the tamping beam 10 is kept flat with respect to the base surface 24 of the slide plate 17 at all set amplitudes of the tamping beam 10.

  For upward or downward adjustment of the stop 22, the screw bushing 19 is twisted in the base frame 15 so that it is offset upward or downward as desired according to the arrow P2. The screw bushing 19 is twisted by an adjustment lever 26 which is attached to the screw bushing 19 in the radial direction and can be operated by a transmission device (not shown) manually or automatically controlled. If a plurality of devices of the type described above are provided over the length of the tamping beam, the associated adjusting lever 26 is adjusted together via a transmission, preferably a horizontal push rod (not shown). In order to be possible, they are operatively connected to each other.

  The tamping beam 10 is deflected with an amplitude A2 corresponding to the distance from the stop portion counterpiece 25 to the stop portion 22. By means of the stop 22, it is possible to continuously adjust the top dead center of the tamping beam 10, and thus the amplitude A2, without changing the bottom dead center of the tamping beam 10.

  The base surface of the tamping beam 10 has three regions in its profile, and in this respect is wider than a conventional tamping beam. The base surface has a rear region 27 that is aligned with the lower surface 24 of the slide plate 17 of the pavement screed 16 at the bottom dead center and is located immediately in front of the slide plate 17. On the side away from the ride plate 17, i.e. on the side of the tamping beam located forward in the direction of travel of the road finishing device, there is a relatively steep run-in slope for the material to be paved. A transition part 29 is provided between the approach slope part 28 and the rear region 27, and the transition part also has a slope toward the front, but the slope is smaller than that of the approach slope part 28. The total width of the base surface of the tamping beam 10 is 4 to 10 cm, and preferably 5 to 8 cm when the width of the rear region 27 is preferably 2 cm. The inclination of the transition part 29 is preferably 1 ° to 20 °, and its width is preferably 4 to 6 cm. By keeping the bottom dead center constant at all amplitudes of the tamping beam 10, a greater overall width of the base surface and the construction of the transition region 29 is possible, so that it acts on the pavement even at small amplitudes. The tamping force is large enough to sufficiently solidify the pavement located below the tamping beam 10.

  In the second embodiment of FIG. 2, an imbalance 31 is disposed on the shaft 30 of the cam drive 13, thereby creating a vibration of the pavement screed 16. The rotation angle position of the imbalance 31 is opposite to the rotation angle position of the cam 14 so that the centrifugal force of the imbalance 31 opposes the movement of the tamping beam 10.

  In the third embodiment of FIG. 3, the cam drive 13 also acts as a drive 32 for a device (not shown) for creating vibrations of the pavement screed 16. This additional drive 32 is attached to the base frame 15 of the pavement screed 16 and has another head surface 33 with another push rod 34. The cam 14 rolls over this additional head surface 33, creating another push rod 34 deflection, illustrated by the cam dashed line. The additional push rod 34 is pretensioned against this deflection by another return spring 35, so that the additional push rod 34 returns to its initial position as soon as the cam 14 opens the other head surface 33, As a result, an oscillating motion indicated by an arrow P3 is created, and this is transmitted to the pavement screed 16 by a transmission device (not shown).

  In the fourth embodiment of FIG. 4, the tamping beam 10 'comprises two push rods 11a, 11b that are spaced apart but parallel to each other, and these push rods 11a, 11b are connected to the camshaft 30'. And two cams 14a and 14b are vibrated vertically by a cam driving device 13 ′. The cam drive 13 ′ is attached to the base frame of the road finishing device by means of a shaft bearing 37.

  The two push rods 11a, 11b are similarly operatively connected to devices 40a, 40b that adjust the amplitude of the tamping beam 10 '. In order to avoid repetition, only the device 40a shown on the left side will be described below in relation to the push rod 11a. Accordingly, the following description also applies to a similar device 40b shown on the right.

  The push rod 11a includes a collar 21 ', by which a retracting device configured as a compression spring 20 is supported upward. The compression spring 20 is further supported downward by an adjustable stop 41. When the push rod 11a and the tamping beam are displaced toward the bottom dead center by the cam 14a, the compression spring 20 is pretensioned. It acts as a drive and moves the push rod 11a along with the tamping beam 10 'to top dead center independent of the cam drive 13'.

  In the example shown, the stop 41 is adjusted by a transmission configured as a spindle drive 42 attached to the base frame 15 of the road finishing device. The spindle driving device 42 is located at the center between the two push rods 11a and 11b. In the illustrated example, this is configured symmetrically with respect to the two push rods 11a, 11b. That is, although different similar adjusting devices are assigned to the push rods 11a and 11b, only the adjusting device assigned to the left push rod will be described below. Accordingly, all described members are provided in pairs. The adjusting device comprises a screw spindle 43 parallel to the push rods 11a, 11b, which is rotatably mounted at one end to a base frame side housing 44 and at its free end to a carriage 45. Installed. The carriage 45 is provided with a spindle nut 46, whereby the position of the carriage 45 is adjusted upward or downward when the screw spindle 43 is rotated according to the rotation direction. A horizontal arm 49 is attached to the carriage 45, and a stop 41 is formed at the free end thereof.

  The rotation of the screw spindle 43 is performed by a vertical rack 47 that engages with a pinion 48 on the screw spindle 43. The rack 47 includes a connection piece 49 for an adjusting device (not shown), and can be adjusted manually or automatically by the adjusting device. In addition to the example shown, it is also possible to operably connect one rack to the pinions of both adjusting devices so that both adjusting devices can be adjusted synchronously.

  The stop part counterpiece 50 is located below the stop part 41 at the end of the push rod 11a on the tamping beam side. The stop portion counter piece 50 includes a shoulder 51 that moves on the stop portion 41 or the buffer member 52 on the stop portion 41 when the upward movement of the push rod 11a is stopped due to the amplitude restriction.

  The top dead center of the oscillating movement of the tamping beam 10 ′ is arbitrarily adjusted by adjusting the stop 1, while the bottom dead center depending on the amplitude of the cam driving device 13 ′ is kept constant.

Claims (21)

A method in which the tamping beam has a swinging vertical vibration having a top dead center and a bottom dead center, the top dead center is adjustable, and the bottom dead center is maintained constant,
The vertical vibration is created by driving the tamping beam toward the bottom dead center, disconnecting it from the bottom dead center, and retracting the tamping beam toward the top dead center. A method for adjusting the amplitude of a tamping beam of a road finishing device, characterized in that it is adjustable by an arbitrarily adjustable regulation of the length of the road finishing device.   The method for adjusting the amplitude of the tamping beam of a road finishing device according to claim 1, wherein energy is stored during driving of the tamping beam, and the energy is used to retract the tamping beam. The adjustment of the top dead center is performed as a function of at least one reference value, which is the hydraulic pressure of the tamping beam drive, the compressive force of the tamping beam, the compressive stress of the push rod of the tamping beam. 3. A tamping beam for a road finishing device according to claim 1 or 2, comprising any one of a vertical movement of a paved screed structure, a density of pavement material or soil hardness behind the paved screed, or a combination thereof. To adjust the amplitude.   The method of adjusting the amplitude of the tamping beam of the road finishing device according to any one of claims 1 to 3, wherein the frequency of the oscillating vibration is set as a function of the top dead center.   The method for adjusting the amplitude of the tamping beam of the road finishing device according to any one of claims 1 to 4, wherein the collision distance is kept constant. A device for adjusting the amplitude of a tamping beam (10) of a road finishing device having a tamping beam (10) having a swinging vertical vibration having a top dead center and a bottom dead center by a first driving device,
Including an adjusting device for the top dead center while maintaining the bottom dead center constant,
In order to retract the tamping beam (10), a second driving device acting in the direction toward the top dead center is provided, and the second driving device acting in the direction toward the top dead center is the first driving device. A device for adjusting the amplitude of the tamping beam of the road finishing device, which is separated from the drive device and the length of the retreat path can be arbitrarily adjusted for the amplitude adjustment.   The first drive is configured as a cam drive (13) in which the tamping beam (10) is operatively connected for displacement to the bottom dead center or as an eccentric shaft having a constant amplitude (A1), The cam drive (13) is not operatively engaged with the tamping beam (10) for deflection of the tamping beam (10) to the top dead center, and the tamping beam (10) is not dead. A retraction device is provided as a second drive device that is operatively connected for deviation to a point and is independent of the amplitude of the cam drive device (13), and can be arbitrarily adjusted vertically to determine the top dead center 7. A device for adjusting the amplitude of the tamping beam of a road finishing device according to claim 6, wherein a stop (22, 41) is provided. 8. A device for adjusting the amplitude of a tamping beam of a road finishing device according to claim 7 , wherein the retracting device is a spring (20). 9. A device for adjusting the amplitude of a tamping beam of a road finishing device according to claim 7 or 8 , wherein the stop (22, 41) for the top dead center is continuously adjustable. The stop portion (22) for the top dead center is configured as a bushing in which the push rod (11) of the tamping beam (10) is guided, and the push rod (11) includes a stop portion. A device for adjusting the amplitude of the tamping beam of a road finishing device according to any one of claims 7 to 9, wherein a counterpiece (25) is provided. The bushing is configured as a screw bushing (19) with an external screw (36) attached to a complementary screw part fixed to the base frame, whereby the screw bushing (19) by twisting the screw bushing (19) The apparatus for adjusting the amplitude of the tamping beam of the road finishing device according to claim 10, wherein an axial displacement of 19) is produced. The stop for the top dead center (22, 41) adjusts the amplitude of the tamping beam road finisher according to any one of claims 7-11 in the transmission is thus adjustable apparatus. Device for adjusting the amplitude of the tamping beam of a road finishing device according to any one of claims 7 to 12, wherein the stop (22, 41) for the top dead center comprises a shock absorber. Base surface of the tamping beam (10) includes a rear region (27) extending in a plane provided with the base surface of the pavement screed (16) to (24), a front penetration slope (28), forward device for adjusting the amplitude of the tamping beam road finisher according to any one of claims 7-13 that have a intermediate transition region (29) comprising an inclined rising Te. 15. A device for adjusting the amplitude of a tamping beam of a road finishing device according to claim 14, wherein the slope of the intermediate transition region (29) rises forward with a tilt angle of 1 [deg.] To 20 [deg.]. A device for adjusting the amplitude of the tamping beam of a road finishing device according to any one of claims 7 to 15 , wherein the cam drive (13) comprises an imbalance (31) for creating paved screed vibrations. The amplitude of the tamping beam of a road finishing device according to any one of claims 7 to 16 , wherein the cam drive (13) is configured as a drive (32) for a device that creates paving screed vibrations. Device to adjust. Each comprising a two mutually spaced apart push rod with a device according to any one of claims 6-17, compaction beam for road finisher. 19. A tamping beam according to claim 18 , wherein the adjusting device of the two devices for amplitude adjustment is operatively connected to each other via a transmission. Wherein the drive movement device for the adjusting device, tamping beam of claim 19 which is synchronized in the rotation speed and rotation angle position for the top dead center assigned to both the push rod. A road finishing apparatus comprising the apparatus according to any one of claims 6 to 17 or the tamping beam according to any one of claims 18 to 20 .

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