EP3138961A1 - Paving screed - Google Patents

Abstract

The invention relates to a screed (3) for road pavers (1), with a compressing unit drivable in cyclic work cycles with a selectable stroke (H) and selectable frequency (F), in particular a tamper (13) with a tamper strip (14) for pre-compacting one built-in material (5) built-in covering (6), characterized in that the compression unit has an adjusting gear (24) for remote-controlled adjustment of the stroke (H) of the compression unit, and that in the screed (3) the adjusting gear (24) for adjusting a Position of an eccentric bushing (23) relative to a bearing eccentric shaft (15) is provided.

Description

The invention relates to a screed according to the preamble of patent claim 1.

When installing a pavement made of bituminous or concrete material with a paver, the floating towed screed has to compact the paving as evenly as possible over the entire paving width and to create a closed, level structure. The compression unit, for example a so-called tamper or a tamper and an unbalance vibrator, is intended to produce the highest possible constant and continuous over the lining thickness pre-compaction, so that different or varying coating thicknesses have no appreciable effect on the final compaction. The stroke and the frequency of the tampers influence the precompression and the floating behavior of the screed. The larger the stroke, the higher the pre-compression becomes and the deeper pre-compressed. The frequency can be individually adjusted infinitely. EP 0 493 664 A For example, it discloses the tamper frequency, for example, to adjust as a function of the installation speed. It is also expedient to adapt the tamper stroke of the lining thickness so that the screed incorporates the lowest possible positive angle. If the stroke is too large for the lining thickness, a negative angle of attack of the screed may result, which may lead to an open, cracked surface structure or uncontrollable leveling behavior of the screed, resulting in unevenness. The covering thickness is specified, for example, by adjusting the height of the traction points of the screed on the paver. The frequency and the installation speed must be adapted to each other. So far, the vote is individually chosen so that the screed incorporates the least possible positive angle. On the other hand, the installation speed determines the effect of the compacting unit on the surface. The installation speed should be selected so that the most constant possible material supply is ensured by the transport vehicles. Since the installation speed has a great influence on the precompression, it should be ensured that the screed incorporates a low positive angle of attack in order to ensure good planarity, ie the driven installation speed must allow good precompression. The stroke has hitherto been adjusted manually in several stages, whereby the installation operation must be interrupted in each case. However, each stroke is only a compromise because it fits only to a lining thickness. For example, a larger amount of built-in material is pre-compressed by the tamper bar due to an increase in stroke within the set lining thickness. To increase the pre-compression is also by increasing the frequency. In certain cases, the Tamper with an additional unbalance vibration device in the screed cooperate to achieve even higher pre-compression and flatness.

From the information document "For each task the right screed", the company Joseph Vögele AG, 68146 Mannheim / DE, no. 2400/10 / 2.1997, page 4, it is known to manually adjust the stroke of a tamping unit having a tamper, a rotatable eccentric bushing rotating in a connecting rod driving the tamper strip is rotated relative to an eccentric section of the driving eccentric shaft. The eccentric bushing is stretched on the eccentric portion of the eccentric shaft and thus rotatably coupled to the eccentric, and can rotate after loosening a clamping screw relative to the eccentric and fix it again. The eccentric shaft is driven by a hydraulic motor whose speed is e.g. is infinitely variable. If a certain lining thickness is determined before installation, then the stroke is set to this lining thickness. If the covering thickness is changed, the installation must be interrupted and the stroke adjusted to the new covering thickness. Since the lining thickness can vary even during installation due to external influences, the set stroke often does not match the lining thickness, whereby the precompression varies and the angle of attack of the screed may change, and as a result the flatness and surface quality of the lining suffer. The adjustment is time consuming and cumbersome since e.g. eight connecting rods may be provided in the base beam alone, and requires great care to uniformly pre-compact over the working width.

Out DE 198 36 269 A a method is known to vary the frequency of the tamper depending on the angle of attack of the screed, wherein the angle of attack of the screed is scanned continuously via at least one sensor. The adjustment of the frequency takes place automatically, while other machine parameters are set by an operator depending on the respective installation parameters.

Out DE 40 40 029 A a method is known in which the frequency of the tamper is varied depending on the actual installation speed during installation. Other machine parameters are set flanking by the operator. For example, the stroke of the tamper must be adjusted manually before installation or during an installation interruption. This means a considerable burden for the operator and a high level of expertise.

The invention has for its object to provide a screed and a paver that allow a consistently high quality of a built-in coating, so For example, the installation of a covering with uniform working strength in the direction of travel and both in the transverse direction and the working direction uniform compression.

The stated object is achieved with the features of claim 1.

Since at least the stroke of the compression unit is automatically adjusted depending on at least one installation parameter such as at least the installation speed and / or covering thickness, the stroke and the respective installation parameters are in an optimal relationship to each other, resulting in not only a largely constant pre-compression regardless of variations of the installation parameters but an optimally small positive angle of attack of the screed is maintained, which ensures a closed and even surface of the lining and consistently high quality of the installed lining. The adjustments can be made conveniently on all connecting rods at the same time.

In the screed allows, preferably even during ongoing installation operable adjusting, to adjust the stroke of the compression unit so that the hub, for example, before or during changes in installation speed and / or the thickness of lining, as they occur during installation either due to external influences or to be made on purpose, in each case largely optimally fits the speed of installation and / or covering thickness, resulting in an optimal and constant pre-compression and high quality of the installed lining. If the stroke can be adjusted during installation, which is advisable for all connecting rods, the stroke adjustment installation does not need to be interrupted, and the personnel is relieved. The paver operator or an operator on the screed may alternatively make the adjustment as needed. However, the adjustment is particularly useful automatically depending on installation parameters such as the installation speed and / or covering thickness, so that the uniform high final quality of the coating is achieved without appreciable influence of the staff.

The road paver equipped to carry out the method and with this screed makes it possible, thanks to the control system and generated by actuators actuators, to achieve a consistently high quality of a built-in covering, in an automatic sequence a uniform in installation direction lining thickness and both be regulated in the installation direction as well as transversely to uniform compression, without requiring an operator to solve complicated tasks or to select parameters. Because the manipulated variables, at least by actuators for Creation of the stroke and / or the frequency of the tampers are generated automatically and process-oriented depending on relevant process parameters or machine parameters or installation parameters.

Here, the compacting unit comprises at least one tamper with a plurality of connecting rods in each section of the screed, i. in the basic screed, in each extending screed, and possibly also in screed widening parts attached to the screed. In order to achieve even better pre-compaction, the respective tamper can be combined with an unbalance vibrator, which acts on the screed plate of the screed with substantially vertically acting unbalance pulses. The vibration frequency can, for example, as known, be adjustable over a flow control valve in a certain range, and according to the method also be automatically mitverstellt depending on the at least one installation parameters. If the screed also has a high compression device (see the above-mentioned technical information "The right screed for each task", page 8), which works with high-frequency hydraulic pressure pulses, the frequency and pressure are adjustable, can also be appropriate adjustment of the high compression device depending on made such installation parameters, so that, for example, with varying installation speed and / or extremely uneven lining thickness results in a consistently high final quality of the installed coating.

Especially in view of producing no noticeable changes in the covering thickness or forming the surface in the installed covering, it is favorable in a suitable method variant flanking the stroke and the frequency and / or even the angle of attack of the screed depending on at least one detected or automatically adjust the entered installation parameters. The angle of attack is adjusted by means of the leveling cylinder on the paver, while the frequency of the tamper, if necessary, for example, is adjusted via the rotational speed of the rotary drive of the tamper.

In order to relieve an operator to a great extent, it is expedient according to the method to record the setting angle of the screed and / or the density and / or the rigidity and / or the temperature of the paving material, preferably by means of at least one, as the adjustment parameter for the adjustment of at least the stroke of the tamper Sensors, and, preferably, compared with a target specification, before the adjustment of at least the stroke takes place. The angle of attack is, for example, an extraordinarily meaningful indicator of optimum compaction, which depends essentially on the stroke of the tamper.

In an expedient variant of the method, in addition to the stroke, the frequency of the compression unit is automatically, preferably, adjusted along a characteristic curve dependent on at least one installation parameter or in a characteristic field. The automatic frequency adjustment may also include an unbalance vibrator. This ensures that both the stroke and the frequency are in optimum proportion to the installation parameter.

In an expedient variant of the method, the frequency of the tamper is adjusted according to a characteristic curve or a characteristic field, for example in direct dependence on the respectively set stroke. However, the characteristic curve or characteristic map can also be based on a predetermined proportionality between the stroke and the frequency, wherein, preferably, this proportionality is selected as a function of at least one installation parameter or a predetermined change of at least one installation parameter, such as the installation speed, the angle of attack of the screed , the density or temperature or rigidity of the paving material, and the like.

In an expedient variant of the method, in which the compacting unit has a tamper with a tamper strip which can be driven via at least one connecting rod, an eccentric bushing and a driven eccentric shaft to substantially vertical working strokes, e.g. even with ongoing installation, the eccentric bushing and the eccentric shaft rotated relative to each other and adjusted from the relative rotational position between the eccentric bushing and eccentric shaft stroke of the tamper bar along the curve or in the map. The characteristic curve or the characteristic field is determined in advance. The characteristic curve or the characteristic diagram can be selected such that the precompression in the lining remains at least substantially constant, independently of changes in the lining thickness and / or the installation speed.

According to the method, furthermore, at least the stroke can be adjusted by a control system for which a certain degree of precompression is set and the control parameters such as at least the installation speed and / or the lining thickness are input or supplied. The machine operator or an operator on the screed need not worry about the adjustment during installation, although, in a simple process variant, the adjustment can be made individually by hand. For this purpose, the operator does not need to manipulate the compression unit, but he provides the respective manipulated variable, eg for the hub, conveniently on Control system or in the control panel, which is then implemented by an actuator accordingly.

Appropriately, the stroke of the tamper bar is adjusted hydraulically and / or electrically and / or mechanically by means of an adjusting mechanism arranged between the eccentric shaft and the eccentric bush, expediently either continuously or in predetermined, previously determined as optimal steps.

In the screed advantageously a hydraulically and / or electrically and / or mechanically actuated adjusting mechanism is provided, which allows, if necessary, even during ongoing installation, the adjustment of the stroke at any time, without having to intervene manually.

For this purpose, either on the screed or in the paver, an operatively connected to the adjusting, automatic, preferably computerized, control system be provided in the installation parameters such as at least the installation speed and / or the lining thickness are entered or there are, and on the For example, a degree of compaction to be generated by the compacting unit is adjustable. The control system then automatically adapts the stroke to changes in at least one installation parameter that are apparent during ongoing installation.

For this purpose, the control system should have at least one of installation parameters dependent characteristic or a map for the automatic adjustment of the stroke or the stroke and the frequency of the working cycles of the compression unit.

In an expedient embodiment of the screed, the adjusting mechanism is provided between a rotatably driven eccentric shaft in the screed and an eccentric bush rotatable on the eccentric shaft in a connecting rod which drives the tamper strip with essentially vertical working strokes. The stroke of the Tamperleiste is thus adjustable by a relative rotational adjustment between the eccentric bushing and the eccentric shaft. Depending on the relative rotational position of the eccentric bushing on the eccentric shaft, half the stroke of a power stroke results from the sum of the eccentricity of an eccentric portion of the eccentric shaft and a portion up to the maximum of the eccentricity of the eccentric bushing.

In another expedient embodiment of the screed, the adjusting mechanism is arranged between a rotatably driven eccentric shaft in the screed and a rotationally fixed on the eccentric shaft, but displaceable transversely to the axis of the eccentric shaft, rotatably mounted in a tamper strip driving connecting rod eccentric bushing arranged such that the stroke is adjustable by a transverse displacement of the eccentric bushing relative to the eccentric shaft. The then effective extent of the eccentricity of the eccentric bush depends on the extent of the transverse displacement of the eccentric bushing relative to the eccentric shaft. The eccentric bushing acts eccentrically, but can be formed circular cylindrical.

In a further advantageous embodiment of the screed, the adjusting between a rotatably driven eccentric shaft bearing bracket and a pivotally connected to the tamper bar connecting rod, adjustable in the bearing lever is arranged (toggle principle), wherein the adjusting lever and a driven by the eccentric shaft push rod in a common Joint axis are coupled to the connecting rod, such that an adjustment of the adjusting lever in the bearing block changed over the push rod generated by the rotation of the eccentric shaft, effective stroke of the tamper bar.

In the embodiment with the eccentric shaft rotatable relative to the eccentric shaft expediently rotatably mounted in the eccentric shaft an axially adjustable driver, which engages in a thread-like guide track of the eccentric shaft rotatable eccentric bushing. During an adjustment, preferably by electrical and / or hydraulic and / or mechanical means, of the driver in the axial direction of the eccentric shaft, the eccentric bushing is rotated via the thread-like guide track and fixed again in a rotationally fixed manner in the respectively selected setting.

In an alternative embodiment, an axially movable adjusting mechanism is arranged rotatably in the eccentric, the clockwise cooperating with the rotatably mounted eccentric rotary stepper to rotate the eccentric bush in steps relative to the eccentric shaft, and rotatably in the selected rotational position with the eccentric shaft couple.

In a further alternative embodiment may be provided between the eccentric shaft and the eccentric bush, a clamping mechanism which couples the eccentric positively or frictionally or positively with the eccentric shaft and temporarily supported by a supported in the screed axial release mechanism in a release position, in which the coupling is canceled between the eccentric shaft and the eccentric bush and these two components are rotatable relative to each other or are automatically rotated.

In a further expedient embodiment with the eccentric bush displaceable transversely to the axis of the eccentric shaft, between the eccentric shaft and the eccentric bush rotatably coupled to the eccentric shaft, at least one control shaft adjustable by means of at least one control rod axially displaceable in the eccentric shaft is adjustable with respect to the eccentric shaft, guiding the eccentric bushing with an oblique guide Guidance surface provided. About the inclined guide surface of the guide stone is displaced transversely to the axis of the eccentric shaft to adjust the eccentric bush or to change their effective portion of the eccentricity. The eccentric bushing does not need to be eccentric here, but may be cylindrical.

It is expedient if the inclined guide surface of the guide block, expediently two diametrically opposite guide blocks, axially displaceable abuts an inclined ramp either in the eccentric bushing or on the control rod.

In an expedient embodiment, in which the tamper strip is driven by a toggle mechanism, the bearing block has a straight or arcuate guideway into which a pivot abutment of the adjusting lever engages, which is displaceable by means of the adjusting mechanism along the guideway and fixed in selected Einstellpositionen, wherein the Course of the guideway has at least approximately to the axis of the eccentric shaft. The adjustment of the swiveling abutment of the adjusting lever results in a change of the eccentric shaft tapped strokes of the tamper strip. In this case, it is expedient for the guideway to be arranged with respect to the axis of the eccentric shaft and the articulation axis on the connecting rod in such a way that a bottom dead center of the work cycle induced by the eccentric shaft of the tamper bar connected to the connecting rod is independent of the setting position of the swiveling abutment of the adjusting lever remains stationary along the guideway, preferably or for example stationary in relation to a glazed plate mounted on a frame supporting the bearing block screed. This means that only the top dead center of the power stroke is adjusted in the vertical direction, and the position of the bottom dead center with respect to the screed plate does not change when adjusting the stroke.

To capture installation parameters or changes of installation parameters and to submit the control system or enter into this, is in an expedient embodiment of the paver on the paver itself and / or the screed and / or the spars at least one sensor, preferably several in and across the installation direction distributed sensors, designed to record actual installation parameters, wherein the sensors are linked to the control system or can be linked. Since at least relevant installation parameters, such as at least the angle of attack of the screed, or changes thereof can be detected by the sensors and transmitted to the control system, the operator is relieved, and results in a consistently high quality of the installed coating.

In a further expedient embodiment, the paver and / or screed has an input and display section on the control system or a machine control associated with the control system for additional or alternative setting of quantities, values or parameters, at least for the lift and / or frequency, however also the angle of the screed, provided that can be used by the operator to enter additional information in the control system as needed.

Fig. 1

eine schematische Seitenansicht eines mit einer Einbaubohle ausgestatteten Straßenfertigers beim Einbauen eines Belages,

Fig. 2

ein Diagramm zur Verdeutlichung zweier Kennlinien bzw. eines Kennfeldes,

Fig. 3

eine Perspektivansicht eines Teiles einer mit einem Verdichtungsaggregat ausgestatteten Einbaubohle,

Fig. 4

eine Perspektivschnittdarstellung einer Ausführungsform einer Hubverstelleinrichtung,

Fig. 5

eine perspektivische Teilschnittansicht einer weiteren Ausführungsform einer Hubverstelleinrichtung,

Fig. 6

einen Längsschnitt einer weiteren Ausführungsform einer Hubverstelleinrichtung,

Fig. 7

einen Längsschnitt einer weiteren Ausführungsform einer Hubverstelleinrichtung,

Fig. 8

eine Perspektivschnittansicht einer weiteren Ausführungsform einer Hubverstelleinrichtung,

Fig. 9

eine Perspektivschnittdarstellung einer weiteren Ausführungsform einer Hubverstelleinrichtung, und

Fig. 10

eine Perspektivansicht einer weiteren Ausführungsform einer Hubverstelleinrichtung.

With reference to the drawings, embodiments of the subject invention will be explained. Show it:

Fig. 1

a schematic side view of a equipped with a screed paver when installing a coating,

Fig. 2

a diagram to illustrate two characteristics or a characteristic field,

Fig. 3

a perspective view of a part of a screed equipped with a compactor,

Fig. 4

a perspective sectional view of an embodiment of a Hubverstelleinrichtung,

Fig. 5

a perspective partial sectional view of another embodiment of a Hubverstelleinrichtung,

Fig. 6

a longitudinal section of another embodiment of a Hubverstelleinrichtung,

Fig. 7

a longitudinal section of another embodiment of a Hubverstelleinrichtung,

Fig. 8

a perspective sectional view of another embodiment of a Hubverstelleinrichtung,

Fig. 9

a perspective sectional view of another embodiment of a Hubverstelleinrichtung, and

Fig. 10

a perspective view of another embodiment of a Hubverstelleinrichtung.

A paver 1 in Fig. 1 for installation of a covering 6 of bituminous or concrete installation material 5 on a substrate 7 has on a chassis 2 a built-in material bunker 4 and in a cab a control panel P control, for example, with a control system 25 on. Alternatively, the control system 25 could be arranged elsewhere in the paver 1 or in a towed by the paver screed 3, in functional association with the controller or the control panel P or arranged on the screed 3 outside control panel P '.

The screed 3 is attached to Zugholmen 8, which are connected on both sides to articulation points 9 of the paver 1. The articulation points 9 can be moved up and down via adjustment devices 10, such as leveling cylinders, for example to adjust the covering thickness S of the installed covering 6. The screed 3 comprises, for example, a base screed 11 and extending screeds 12, each with a at least one tamper 14 and a tamper strip comprehensive compression unit 13 and the paving material 5 acting screed plate 18, wherein, preferably, the screed 3 with a small positive angle α works floating against a parallel to the ground 7 level. The Tamperleiste 14 is cyclically driven in pre-compression in working cycles and performs strokes H with a frequency F. With ongoing installation, the paver 1 moves at a speed of installation V on the ground. 7

Optionally, the screed 3 (in the base beam 11 and each Ausziehbohle 12) additionally contains at least one unbalance vibrator (not shown) for applying the Glättbleches 18 with vertical pulses, and, optionally in working direction behind at least one pressure bar of a high compression device (not shown). The unbalance vibrator and the high-compression device are optional options of a screed 3, while the tamper 14 may be part of the basic equipment.

The installation speed V as well as the covering thickness S are installation parameters which may even change or be changed during installation. The tamper 14 has to produce a pre-compression in the loose on the substrate 7 poured paving material 5, regardless of changing installation parameters, at least as far as possible should be kept constant. Further installation parameters which may be relevant for the precompression may be the type and consistency of the paving material 5, its temperature, the ambient conditions, the design of the paving screed 3, and the like.

According to the pre-compression is kept substantially constant regardless of the installation parameters changing during installation by at least the stroke H of the working cycles of the tamper 14 depending on at least one installation parameter, possibly even automatically adjusted, expediently also the frequency F, namely via the control system 25, which receives or knows at least one installation parameter as a control variable, and on which, preferably, a desired degree of precompression is set as the desired value. The control system 25 can be operated with characteristic curves and / or a characteristic map. Each characteristic curve or the characteristic field is predetermined and stored. Suitably, the control system 25 is automatic and computerized.

Fig. 2 shows a diagram of the stroke H (or the frequency F) on the lining thickness S (or the installation speed V). The solid curve H illustrates how the stroke H with increasing lining thickness S (or increasing installation speed V) is continuously increased here. In dashed lines, the measure known from the prior art is indicated to change the stroke H in each case with interrupted installation operation, the obliquely hatched fields X and Y illustrate that the changed after the stair profile stroke H or the pre-compression over a considerable part of the changes in the lining thickness S or the installation speed V does not fit. The solid curve F illustrates the also possible change in the frequency with increasing lining thickness S or installation speed V. The curves H, F can be stored in a map that works the control system 25 during ongoing installation. The characteristic F, H or the map is predetermined so that in view of high and consistent final quality of the built-in coating 6 is always an optimal ratio between the lining thickness and / or the installation speed and at least the stroke H, expediently also the frequency F optimal is. The adjustment of the stroke H, and possibly also the frequency F, is expediently either automatically and even during installation under tapping changes of at least one installation parameter such as the lining thickness S and / or the installation speed V, or operator-guided.

Fig. 3 illustrates the interior of the screed 3 with the tamper 14. The tamper strip 14 is shielded at the front of the screed 3 by a cover 19 (retractable spout) and between the cover 19 and the front edge of the Glättbleches 18 guided substantially vertically movable. On a lower side of the screed plate 18 supporting frame 17 of the screed 3, a bearing block 16 is mounted, the relative altitude is adjustable for example by means of an adjusting screw 20, such that the tamper strip 14 assumes a certain relative position to the screed plate 18 at the bottom dead center of each work cycle. In the bearing block 16 (over the length of the frame 17, a plurality of bearing blocks 16 may be mounted) is an eccentric shaft 15 rotatably mounted, each having an eccentric portion 22 with a certain eccentricity. The eccentric portion 22 is located in a connecting rod 21 which connects the eccentric shaft 15 with the tamper strip 14. On the eccentric portion 22 of the eccentric shaft 15 is an eccentric bushing 23, for example, in the embodiment shown via an adjusting 24, which is supported on the frame 17, rotatably coupled to the eccentric portion 22 and rotatably mounted in the connecting rod 21. By means of the adjusting gear 24, the eccentric bushing 23 can rotate relative to the eccentric portion 22 of the eccentric shaft 15 and rotatably coupled in the rotational position respectively set with the eccentric shaft 15. The relative rotation of the eccentric bushing 23 relative to the eccentric section 22 effects an adjustment of the stroke, which the connecting rod 21 transmits to the tamper strip 14. The adjustment of the stroke can, preferably, be made automatically via the control system 25, which is in operative connection with the adjusting gear 24, in response to changes in certain installation parameters. Alternatively, the adjusting mechanism 24 could be actuated or operated as required by the user.

The representation of the adjusting gear 24 in Fig. 3 is schematically because the adjusting gear 24 of course due to the rotational movement of the eccentric shaft 15 indirectly as Hubverstelleinrichtung via the eccentric shaft 15 has an effect on the eccentric bushing 23. This will be explained in detail with reference to the further embodiment.

At the in Fig. 4 shown adjusting the 24 eccentric sleeve 23 is rotatably mounted on the eccentric portion 22 of the eccentric shaft 15. This is hollow, for example, such that an internal control rod 27 leads to an outside of the eccentric shaft 15 adjustment 26. The control rod 27 is coupled to a in a groove 29 axially adjustable in the eccentric shaft 15, rotatably connected to this driver 28 which engages with an outwardly projecting from the groove 29 extension 30 in a thread-like guide rail 31 of the eccentric bushing 23.

The eccentric portion 22 has the axis of rotation of the eccentric shaft 15 has a first eccentricity, but is cylindrical on the outer circumference. The cylindrical outer circumference of the eccentric bush 23 is eccentric with respect to the cylindrical inner circumference. Since the cylindrical outer periphery of the eccentric bushing 23 is rotatable in the connecting rod 21, and the tamper strip 14 is movable in a fixed vertical plane, the extent of the resulting eccentricity of the first and second eccentricities depends on which relative rotational position between the eccentric bushing 23 and the eccentric portion 22nd is set. The effective amount of eccentricity determines half the stroke H of a power stroke. By displacing the driver 28 in the direction of the axis of the eccentric shaft 15, the stroke H can thus be steplessly adjusted between a minimum and a maximum. The eccentric bushing 23 always remains rotatably coupled to the eccentric shaft 15. The set axial position of the driver 28 is held, for example, by the adjusting drive 26.

The eccentric shaft 15 is, for example, on in Fig. 4 rotatably mounted left end in a bearing block, not shown here and is of in Fig. 4 Right end driven by a hydraulic motor, not shown. The adjusting drive 26 can therefore in front of the left-side end in Fig. 4 be arranged in the screed or on the frame 17.

Fig. 5 differs mainly from Fig. 4 in that the adjusting mechanism 24 contains the driver 28, which is axially displaceable in the outwardly open groove 29 of the eccentric shaft 15, in such a way that the adjusting drive 26 engages via the control rod 27 from the outside of the eccentric shaft 15. The extension 30 of the driver 28 engages in the thread-like guide track 31 of the eccentric bushing 22, although relatively rotatably seated on the eccentric portion 22 of the eccentric shaft 15, but rotatably on the driver 28, the groove 29 and the extension 30 in each axial position of the driver 28 remains coupled to the eccentric shaft 15.

This in Fig. 6 shown adjusting gear 24 has a rotary indexing mechanism, which is cyclically actuated by the example supported on the frame 17 of the screed adjusting 26 to rotate the eccentric bushing 23 relative to the eccentric portion 22 of the eccentric shaft 15. In the connecting rod 21, the eccentric bushing 23 is rotatably supported via at least one rolling bearing 32. In the eccentric portion 22 at least one axial groove 29 is provided, in which an adjusting mechanism 30 is axially movable but rotatably coupled to the eccentric shaft 15 is arranged. At the left-side end of the adjusting mechanism 33 in Fig. 6 a sawtooth toothing 34 (peripheral teeth) is provided, as well as a circumferentially offset sawtooth toothing 35 at the right end of the adjusting 33. The eccentric bushing 23 has at both ends corresponding sawtooth teeth 37 and 36. The axial length of the eccentric bushing 23 between their sawtooth gears 36, 37 is slightly shorter than the clear width between the sawtooth toothings 35, 34. About this difference in width, the adjusting mechanism 33 by means of, for example, an annular piston 41 of the adjustment 26 (hydraulically loadable annular chamber 40) hydraulically adjustable axially. The left-side end of the adjusting mechanism 33 is supported on a spring 39 of a stop 38 on the eccentric shaft 15.

To rotate the eccentric bushing 23 on the eccentric portion 22 of the adjusting mechanism 33 from the in Fig. 6 shown position displaced by the annular piston 41 to the left until the teeth 34, 37 are released and the teeth 35, 36 intermesh. By a circumferential displacement between at least the teeth 34 and 35, the eccentric bushing 23 is rotated by a pitch. Thereafter, the pressure in the annular chamber 40 is reduced, so that the spring 39, the adjusting mechanism 33 back into the in Fig. 6 shifts position shown, and, for example, the eccentric bushing 23 further rotates by a further tooth pitch, which is then again rotatably coupled to the eccentric portion 22.

In Fig. 7 has the adjusting gear 24 as adjusting 26 to the annular piston 41. The adjustment drive 26 can be supported on the frame 17 of the screed. The annular piston 41 engages directly on an axial end of the eccentric bushing 23, which is pressed by the supported on the stop 38 on the eccentric shaft spring 39 via a stop ring 42 and a rolling bearing 43 axially on a conical portion 22 'of the eccentric portion 22 of the eccentric shaft 15 and rotatably is coupled with the eccentric shaft 15. The eccentric bush 23 can be against the force of the spring 39 through the annular piston 41 from the in Fig. 7 Adjust shown position to the left, so that the frictional engagement with the conical portion 22 'is loosened or loosened, and in the rolling bearing 43, for example, the eccentric shaft 15 can rotate relative to the eccentric bushing 23 until the annular piston 41 retracted again and the eccentric bush 23 by the spring 39 are brought into re-frictional engagement with the conical section 22 '. Alternatively, for example, similar to in Fig. 6 , the relative rotational movement are also made on the eccentric bushing 23. The connecting rod 21 makes in the embodiment in Fig. 7 these minor axial movements of the eccentric bushing 23 with. Alternatively, the roller bearing 32 could have an axial play in the connecting rod 21 or on the eccentric bushing 23. In an alternative, not shown, the eccentric bushing 23 could even be rotatably coupled by a toothing with the conical portion 22 'respectively.

At the in Fig. 8 shown embodiment of the Hubverstelleinrichtung with the adjusting gear 24 is in contrast to the previously described embodiments of Fig. 4 to 7 not the eccentric bushing 23 is rotated relative to the eccentric portion 22 of the eccentric shaft 15, but moved transversely to the axis of the eccentric shaft 15 in order to change the total effective eccentricity and thus the stroke.

The eccentric bushing 23 may e.g. with coaxial inner and outer cylindrical peripheries, i. circular cylindrical, formed and rotatably on two opposite guide blocks 44 may be arranged, which are in the outwardly open grooves of the perforated eccentric shaft 15 transversely to the axis of the eccentric shaft 15 slidably and rotatably with the eccentric shaft. Each guide block 44 has internally an inclined guide surface 45 which rests on an inclined guide ramp 47 of a control rod 46, which is axially displaceable in the eccentric shaft 15 by means of the adjustment 26 and in the selected setting position. The adjusting drive 26 may be formed hydraulically, electrically or mechanically. Although the eccentric bush 23 is cylindrical (manufacturing technology favorable), it acts eccentrically relative to the eccentric portion 22.

In the embodiment of the Fig. 9 which is functionally the embodiment of Fig. 8 Similarly, in the eccentric portion 22 of the eccentric shaft 15 two diametrically opposed axial grooves 29 are formed, in which the guide blocks 44 are axially displaceable and rotationally fixed to the eccentric shaft 15 coupled. At each guide block 44 engages a control rod 46 ', which is coupled to the adjusting drive 26 or coupled. The oblique guide surface 47 'is externally formed on the guide block 44 and engages in an axial groove on the inner surface of the eccentric bushing 23 a. In this axial groove, the oblique guide ramp 45 'is shaped, so that by axial adjustment of the guide blocks 44, the eccentric bushing similar to in Fig. 8 is moved transversely to the axis of the eccentric shaft and remains rotationally fixed coupled to the eccentric shaft 15. Again, the eccentric bushing 23 may be cylindrical.

In Fig. 10 the adjusting gear 24 is incorporated into a toggle mechanism, via which the rotational movement of the eccentric shaft 15 is transmitted with its eccentric portion 22 via a rotatably mounted on the eccentric portion 22 thrust rod 48 and a hinge axis 49 on the connecting rod 21 to which the tamper strip 14 is attached. With the connecting rod 21, preferably, on the same hinge axis 49, one end of an adjusting lever 50 is pivotally coupled, which is supported with a pivot abutment 51 (eg a pin) in a guide track 52 of the bearing block 16 'of the eccentric shaft 15. The bearing block 16 'may be fixed on the frame 17 of the screed. The guideway 52 is, for example, a straight or arcuate, slot-shaped slot in the bearing block 16 'and extends in a the eccentric shaft 15 cross-cutting plane. The adjusting drive 26 is effective between the bearing block 16 'and the pivot abutment 51 to adjust the pivot abutment 51 within the guide track 52. As a result, the eccentricity picked up by the eccentric section 22 and transmitted by the adjusting lever 50 to the connecting rod 21 or the stroke of the tamper strip 14 changes.

Suitably, the guideway 52 with respect to the axis of the eccentric shaft 15 and the hinge axis 49 is formed and arranged such that regardless of the adjustment of the pivot abutment 51 in the guideway 52 of the bottom dead center of the strokes of the tamper strip 14 remains stationary in relation to the screed plate 18, ie, only the top dead center shifts during the stroke adjustment.

The rotation of the eccentric shaft 15 moves via the eccentric portion 22, the push rod 48 substantially parallel to the top of the frame 17 back and forth. This oscillating movement causes via the common hinge axis 49 a pivoting movement of the adjusting lever 50 about the pivot abutment 51 following a circular arc section. The adjusting lever 50 derives therefrom a substantially vertical lifting component for the connecting rod 21. The extent of this lifting component is changed by adjusting the pivot abutment 51 in the guideway 52.

The pivot points 9 of the Zugholme 8 of the paver 1 of Fig. 1 with the leveling cylinders 10, for example via actuators 10 '(hydraulic valves or the like.) Height adjustable and affect the angle α of the screed 3. The angle of attack α should be positive but with an optimal size, ie not too shallow and not too steep and is by the Control system 25 kept in optimal size. In addition, 2 lifting cylinders 28 are hinged to the chassis, which engage the Zugholmen 8 and serve to position the screed 3 excavated, for example, for transport, or to perform a screed relief or optionally to increase the contact pressure of the screed 3. The tamper 14 of the compression unit 13 is (see Fig. 3 ) For example, by means of an eccentric drive with selectable stroke H and selectable frequency F operable.

In the control panel P or outdoor control panel P ', a speed selector 26 is provided for setting the installation speed V. The speed selector 26 can be adjusted by an actuator, not shown, if necessary, also from the control system 25 to change the installation speed V. The installation speed V is symbolic indicated sensor 31 is detected and transmitted to the control system 25. The sensor 31 may be placed in the paver, for example, in the control panel P or in a traction drive or scan a reference on the substrate 7. In the control panel P or in the control system 25, an input section 27 may be provided for inputting parameters and / or displaying parameters. The lifting cylinders 28 is at least one actuator 28 ', for example, a solenoid-operated hydraulic valve assigned. Furthermore, as a feature of the paver 1 at least one sensor 30 may be provided, which picks up the temperature, density or consistency of the paving material, for example, immediately before the screed 3 and optionally transmitted as information to the control system 25. This captured information could also be entered by an operator. For example, at the screed 3, at least one sensor 29 is provided, which detects the angle of attack α of the screed relative to the substrate 7. This sensor 29 could tap the angle α also at the Zugholmen 8. It can be provided over the mounting width several sensors 29. Furthermore, a sensor 37 can be provided for picking up the lining thickness S, which scans, for example, the substrate 7 or a reference, not shown, on the substrate 7.

In the paver 1 or the screed 3 actuators for adjusting the Tamperhubes H and the tamper frequency F are provided and can be brought by means of the control system 25 generated control signals to implement control signals. For example, shows Fig. 3 the actuator 24 for the Tamperhub H-forming gear 24 for rotating the eccentric bushing 23 relative to the eccentric 22. The respective adjusted to the mounting parameters setting the Tamperhubes H automatically via the control system 25. The eccentric shaft 15 is rotationally driven, for example by a hydraulic motor 32. Its speed determines the tamper frequency F. As the actuator 33 for the hydraulic motor 32 may serve a solenoid-operated valve, such as a proportional flow control valve, which can be acted upon by the control system 25 with control signals.

Among other things, by means of the control system 25 several different machine or construction site or installation material parameters are automatically controlled in dependence of each other, for example, to minimize error rates in the built-in coating 6 and to increase the quality of the built-in coating 6.

The tamper 14 has to compact the loosely presented paving material 5 so strong that a sufficient for the screed 3 carrying capacity is created. Only then is it guaranteed that the screed 3 with its screed plate 18 with a favorable angle α is dragged floating. The tamper stroke H, the tamper frequency F, the installation speed V and the angle of attack α depend strongly on each other. If, for example, the installation speed V is reduced, this has an effect on the pre-compression of the paving material while the tamper frequency and leveling cylinder setting remain the same. It increases the carrying capacity of the paving material, so that the screed 3 continues to float and reduces the angle of attack α. On the other hand, if the installation speed is increased without increasing the tamper frequency, the load-bearing capacity of the paving material is reduced, and the paving screed builds up with a larger angle of attack α, but with a lower covering thickness S. In order to minimize or avoid such influences on the final quality of the installed covering 6, according to the invention, at least manipulated variables for the compacting unit 13 or the tamper 14 are automatically controlled and regulated by the control system 25 as a function of the relevant processes or machine parameters. In particular, in this way takes place as a contribution to quality assurance a consistent and optimal compression of the paving material over the entire pave width of the screed.

Thus, for example, the angle of attack α is detected by means of the sensor 29 or a plurality of transversely distributed sensors 29 and transmitted to the control system 25, or there for specially responsible for these installation parameters controller to adjust the Tamperhub H at a change in the angle of attack α, so that the angle of attack α is again reduced to an optimum value or can not change appreciably, so that the target lining thickness S is achieved while the optimal pre-compression remains the same.

As a secondary aspect, the angle of attack α can vary over the installation width of the screed 3. Then the control system 25 can make the appropriate adjustment of Tamperhubes H for each tamper 14 individually, so that despite transverse to the installation direction varying covering thickness S, the compression over the pave width remains uniform.

Taking into account the detected angle of attack α or its detected changes, the tamper stroke H and the tamper frequency F can also be adjusted via the control system 25, and an adjustment of the leveling cylinders 10 may additionally be made as an alternative to an adaptation of the tamper frequency F.

The adaptation of the tamper frequency F can be made particularly simple by the tamper frequency F automatically corresponding to a change in the tamper stroke H. is adapted to a characteristic curve or in a characteristic field which is input or present in the control system.

An important installation parameter is, for example, also the density or consistency of the paving material 5. If the road paver 1 is equipped with a sensor 30, as mentioned, by means of which the density or consistency of the paving material can be detected, then the detected value is compared with a target specification, and in the case of a deviation from the target specification via the control system 25, an adaptation of, for example, the tamper stroke H and / or the tamper frequency F and / or the leveling cylinder adjustment is made such that the deviation angle of the detected density or consistency substantially maintains the angle of attack and the same Compression and flatness and thus quality of the coating 6 can be achieved.

The installation speed V is also a significant installation parameter, since an adaptation requires the tamper stroke H and / or the tamper frequency F and / or the leveling cylinder adjustment, for example via the automatic control system 25.

Another significant installation parameters are the rigidity of the paving material 5 and / or its temperature. These installation parameters may, for example, be detected individually and combined by means of the sensor 30 or a stiffness and a temperature sensor and transmitted to the control system 25, or entered after detection by an operator at the section 27, whereupon the control system, if advised by the detected values, the tamper stroke H and / or the tamper frequency F and / or the leveling cylinder adjustment adapts accordingly. As an additional or alternative adaptation, an adjustment to the lifting cylinders 28 can be made, for example, to relieve the screed 3 during installation more or burden with emphasis in the direction of the ground 7, again in view, the angle of attack α as uniform as possible keep, and let the screed 3 work with even compaction of the coating 6.

In essence, such automation minimizes error rates and costs and improves quality, with significant relief for the operator of the paver operator being an automatic but welcome consequence of this method.

Claims (17)

Screed (3) for road paver (1), with a cyclic working cycles with selectable stroke (H) and selectable frequency (F) drivable compression unit, in particular a tamper (13) with a Tamperleiste (14), for pre-compacting a paving material (5 ) built-in covering (6), characterized in that the compression unit has an adjusting gear (24) for remote-controlled adjustment of the stroke (H) of the compression unit, and that in the screed (3) the adjusting gear (24) for adjusting a position of an eccentric bush ( 23) is provided relative to a bearing eccentric shaft (15). Screed according to claim 1, characterized in that the eccentric bushing (23) in a the tamper (14) of the tamper (13) driving with substantially vertical working cycles connecting rod (21) is arranged. Screed according to claim 2, characterized in that for adjusting the stroke (H) by means of the Verstellgetriebes (24) in the connecting rod (21) mounted eccentric bushing (23) relative to the eccentric shaft (15) rotatable or transversely displaceable. Screed according to one of the preceding claims, characterized in that the adjusting mechanism (24) hydraulically and / or electrically and / or mechanically, preferably continuously or in steps, preferably during ongoing installation, can be actuated. Screed according to one of the preceding claims, characterized in that with the adjusting mechanism (24) operatively connected, automatic, preferably computerized, control system (25) is provided in the installation parameters such as at least the installation speed (V) and / or the lining thickness (S ) And a producible by the compression unit target Vorverdichtungsgrad be entered or maintained. Screed according to claim 5, characterized in that the control system (25) has at least one of installation parameters dependent characteristic for the automatic adjustment of the stroke (H) in dependence on the installation parameters. Screed according to claim 5, characterized in that the control system (25) a dependent of installation parameters map for automatic adjustment of the stroke (H) and the frequency (F) of the working cycles of the compression unit in dependence on installation parameters. Screed according to at least one of the preceding claims 1 to 7, characterized in that the adjusting gear (24) between a rotatably driven eccentric shaft (15) in the screed (3) and one on the eccentric shaft (15) in a tamper strip (14) in the Essentially vertical power strokes driving the connecting rod (21) rotatable eccentric bushing (23) acts such that the stroke (H) of the tamper strip (14) by a relative rotational adjustment between the eccentric bushing (23) and the eccentric shaft (15) is adjustable. Screed according to at least one of claims 1 to 7, characterized in that the adjusting gear (24) arranged between a rotatably driven eccentric shaft (15) in the screed (3) and a rotationally fixed on the eccentric shaft (15), transverse to the axis of the eccentric shaft (15 ) displaceable, in a tamper strip (14) driving the connecting rod (21) rotatable eccentric bushing (23) acts such that the stroke (H) by a transverse displacement of the eccentric bushing (23) relative to the eccentric shaft (15) is adjustable. Screed according to claim 8, characterized in that in the eccentric shaft (15) an axially adjustable, preferably electrically and / or hydraulically and / or mechanically adjustable, driver (28) is rotatably mounted in a thread-like guide track (31) of the rotatable the eccentric shaft (15) mounted eccentric bushing (23) engages. Screed according to claim 8 or 10, characterized in that in the eccentric shaft (15) rotationally fixed an axial, preferably electrically and / or hydraulically and / or mechanically, movable adjusting mechanism (33) is arranged, with a on the eccentric shaft (15) rotatably mounted eccentric bushing (23) has cooperating rotary stepping mechanism (35, 36, 34, 37). Screed according to one of the preceding claims 8, 10 or 11, characterized in that between the eccentric shaft (15) and the eccentric shaft (15) rotatably mounted on the eccentric shaft (15) has a clamping mechanism (39, 42) is provided which the eccentric bushing ( 23) non-positively and / or frictionally and / or positively non-rotatably coupled to the eccentric shaft (15), and that the clamping mechanism by a, preferably hydraulic, in the screed (3) supported axial release mechanism (41) is temporarily brought into a release position, in which the coupling between the eccentric shaft (15) and the eccentric bush (23) lifted and the eccentric shaft (15) and the eccentric bushing (23) are rotatable relative to each other. Screed according to claim 9, characterized in that between the eccentric shaft (15) and the rotatably coupled to the eccentric shaft (15), transversely adjustable eccentric bushing (23) by means of at least one in the eccentric shaft (15) axially displaceably guided control rod (46, 46 ') adjustable guide blocks (44), each with an oblique guide surface (45, 47 ') are provided transversely to the eccentric shaft (15). Screed according to claim 13, characterized in that the oblique guide surface (45 or 47 ') axially displaceable on an inclined ramp (47, 47') either in the eccentric bushing (23) or on the control rod (46, 46 '). Screed according to one of claims 9, 13 or 14, characterized in that the transversely adjustable eccentric bush (23) is cylindrical with coaxial inner and outer peripheries and eccentric acts with its outer periphery for the connecting rod. Screed according to one of the preceding claims, characterized in that the tamper strip (14) is drivable via a toggle mechanism. Road paver (1) comprising a screed according to one of the preceding claims.

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