Abstract
The disclosure relates to a screed arrangement for a road paver comprising a base screed, a first extending screed and a second extending screed, the first extending screed and the second extending screed being arranged in front of the base screed in a pulling direction of the screed arrangement and being movable transversely to the pulling direction relative to the base screed, wherein at least one of the two extending screeds comprises a material deflecting member configured to displace paving material transversely to a pulling direction of the screed arrangement when the extending screed is stationary relative to the base screed, wherein the first extending screed comprises the material deflecting member, wherein the second extending screed is positioned further away from the base screed in the pulling direction than the first extending screed.
Claims
1. A screed arrangement for a road paver comprising a base screed, a first extending screed and a second extending screed, the first extending screed and the second extending screed being arranged in front of the base screed in a pulling direction of the screed arrangement and being movable transversely to the pulling direction relative to base screed, wherein the first extending screed includes a material deflecting member configured to displace paving material toward a central axis to the pulling direction of the screed arrangement when the first extending screed is stationary relative to the base screed, the second extending screed is positioned further from the base screed than the first extending screed in the pulling direction, the base screed comprises a shielding element, and the shielding element is configured to prevent displacement of the paving material lying in front of the base screed laterally beyond a width of the base screed during retraction of the first extending screed.
2. The screed arrangement according to claim 1, wherein the central axis is parallel to the pulling direction, each extending screed has an inner side and an outer side, the inner side is closer to the central axis than the outer side in an extended position of the respective extending screed, and the material deflecting member is arranged on the inner side of the first extending screed.
3. The screed arrangement according to claim 1, wherein the shielding element is present as a plate fastened laterally to a base screed body of the base screed and extending beyond the base screed body in the pulling direction.
4. The screed arrangement according to claim 3, wherein the shielding element is formed substantially at a same height as the first extending screed and/or the shielding element extends in the pulling direction corresponding to a working depth of the first extending screed.
5. The screed arrangement according to claim 1, wherein the shielding element is configured such that it can be adjusted and/or dismantled in the pulling direction relative to the base screed.
6. The screed arrangement according to claim 1, wherein the shielding element is formed as part of a sideshift of the base screed.
7. The screed arrangement according to claim 1, wherein the second extending screed also has a material deflecting member configured for displacing paving material.
8. The screed arrangement according to claim 7, wherein the first extending screed has a shielding element for the material deflecting member of the second extending screed.
9. The screed arrangement according to claim 1, wherein the material deflecting member and/or the shielding element can be heated.
10. The screed arrangement according to claim 1, wherein the material deflecting member is rigidly formed on the first extending screed.
11. The screed arrangement according to claim 1, wherein the material deflecting member is adjustable relative to an extending screed body of the first extending screed.
12. The screed arrangement according to claim 11, wherein the material deflecting member is rotatable and/or displaceable relative to the extending screed body of the first extending screed.
13. The screed arrangement according to claim 1, wherein the material deflecting member is in the form of a plow structure.
14. The screed arrangement according to claim 1, wherein the material deflecting member extends in plan view at a non-zero angle to the pulling direction.
15. The screed arrangement according to claim 1, wherein the screed arrangement comprises a screed operating station at the base screed, and facing the first extending screed.
16. A road paver comprising the screed arrangement according to claim 1.
17. A screed arrangement for a road paver comprising a base screed, a first extending screed and a second extending screed, the first extending screed and the second extending screed being arranged in front of the base screed in a pulling direction of the screed arrangement and being movable transversely to the pulling direction relative to base screed, wherein the first extending screed includes a material deflecting member configured to displace paving material transversely to the pulling direction when the first extending screed is stationary relative to the base screed, the second extending screed is positioned further from the base screed than the first extending screed in the pulling direction, the base screed comprises a shielding element, and the shielding element is configured to prevent displacement of the paving material lying in front of the base screed laterally beyond a width of the base screed when the first extending screed is moved from an extended position toward a retracted position.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] In the following, advantageous embodiments of the disclosure are explained in more detail with reference to a drawing.
[0031] FIG. 1 shows a side view of a road paver;
[0032] FIG. 2 shows a screed arrangement according to the disclosure in schematic representation;
[0033] FIG. 3 shows a screed arrangement according to the disclosure when the extending screeds are extended;
[0034] FIG. 4 shows a screed arrangement according to the disclosure in an extended position of the extending screeds;
[0035] FIG. 5 shows a perspective view of an extending screed in isolated representation;
[0036] FIG. 6 shows a schematically illustrated variant of the screed arrangement according to the disclosure in an extended position of the extending screeds; and
[0037] FIG. 7 shows a schematically illustrated further variant of the screed arrangement according to the disclosure in an extended position of the extending screeds;
[0038] Identical components are marked with the same reference signs throughout the Figures.
DETAILED DESCRIPTION
[0039] FIG. 1 shows a side view of a road paver 1, the paving direction of which is indicated by E. The road paver 1 comprises a tractor 2, which has a mix hopper 3 into which asphalt mix can be poured, for example. This mix or paving material can be transported to the rear end of the tractor 2 by a conveyor system (not shown) against the direction of pave travel E of the road paver 1. There, it can be distributed in front of a screed arrangement 4 of the road paver 1 transverse to the direction of pave travel E. The screed arrangement 4 can be mounted on the tractor 2 in a levelable manner by means of support arms 20. The screed arrangement 2 is towed behind the tractor 2 of the road paver 1 in direction of pave travel E.
[0040] Between the tractor 2 of the road paver 1 and the screed arrangement 4 towed thereon, there is a transverse spreading device 18 (see FIG. 2), for example two transverse spreading augers, to spread the paving material to be processed over the paving width in front of the screed arrangement 4. The screed arrangement 4 is used in particular for smoothing and/or pre-compacting the mix.
[0041] In FIG. 1, the road paver 1 is shown as a wheeled paver. Alternatively, the road paver 1 could have a crawler chassis.
[0042] FIG. 2 shows an embodiment of the screed arrangement 4 according to the disclosure. The screed arrangement 4 is of the “front-mounted screed” type, in which a first extending screed 5 and a second extending screed 6 are arranged in front of a base screed 7 as viewed in a pulling direction Z of the screed arrangement 4. The pulling direction Z of the screed arrangement 4 corresponds to the direction of pave travel E of the road paver 1. The first extending screed 5 is positioned closer to the base screed 7 in the pulling direction Z. The second extending screed 6 is positioned further away from the base screed 7 in the pulling direction Z than the first extending screed 5. Consequently, the first extending screed 5 and the second extending screed 6 are arranged one behind the other in the pulling direction Z, i.e., not in the same plane. The base screed 7 can be a single piece or consist of several parts. Each of the screed parts shown in FIG. 2 has means for smoothing and (pre)compacting paving mix or paving material, for example in the form of screed plates and/or tampers.
[0043] FIG. 2 shows a retracted position of the two extending screeds 5, 6. In the direction transverse to the pulling direction Z, both the base screed 7 and the two extending screeds 5, 6 each have essentially the same working width 16. In order to obtain a larger pave width, the extending screeds 5, 6 can be moved in the extending direction A, i.e., transverse to the pulling direction Z, relative to the base screed 7. Suitable drives and guide systems, for example hydraulic drives, guide rails and/or guide rods, are provided for extending and retracting the extending screeds 5, 6.
[0044] On an inner side 9 of the first extending screed 5, a material deflecting member 10 is formed, which in FIG. 2 is wedge-shaped and integrally configured with an extending screed body 5′ of the first extending screed 5. The base screed 7 has a shielding element 13 for the first extending screed 5. The shielding element 13 is provided laterally on a base screed body 7′. It could, for example, be mounted as a rigid plate 13′″, possibly as part of a sideshift formed on the base screed 7. The shielding element 13 forms a wall extending in the pulling direction Z.
[0045] The material deflecting member 10 allows the paving mix to be displaced from an area 12 of the screed arrangement 4 when the extending screed 5 retracts. This can prevent paving material from being jammed between the shielding element 13 of the base screed 7 and the immediately preceding extending screed 5. The shielding element 13 prevents paving material from being spread out laterally beyond the width of the base screed 7 when the extending screed 5 is retracted in front of the base screed 7. On an outer side 11 of each of the extending screeds 5, 6, a sideshift 5a, 6a is provided, which essentially determines the dimension for the paving width of the new road pavement and prevents the paving mix from spreading beyond a desired width.
[0046] FIG. 3 shows the screed arrangement 4 during the extension of the extending screeds 5, 6 in the extending direction A to produce a larger pave width.
[0047] In the embodiment shown in FIG. 3, the second extending screed 6 also has a material deflecting member 10′ on its inner side 9′. In this embodiment, the material deflecting member 10′ is wedge-shaped and integrally formed with an extending screed body 6′ of the second extending screed 6. This material deflecting member 10′ allows paving mix to be displaced from an area 12′ of the screed arrangement 4 when the second extending screed 6 retracts. This can prevent paving material from being jammed between the sideshift 5a of the extending screed 5 and the extending screed 6.
[0048] FIG. 4 shows the screed arrangement 4 in an extended position 17. As shown, each extending screed 5, 6 has a sideshift 5a, 6a on its outer side 11 and a material deflecting member 10, 10′ on its inner side 9. The extended extending screeds 5, 6 allow the total working width 16′ to be substantially three times a working width that can be produced by means of the base screed 7 alone.
[0049] A variant shown in dashed lines in FIG. 4 provides for the first shielding element 13 to be attached laterally to the base screed 7 so that it can be pivoted by means of a hinge 19. A hydraulic drive (not shown) can be activated for this purpose. In a first position 13′, the shielding element 13 is mounted substantially parallel to the pulling direction Z. The shielding element 13 prevents the paving mix or paving material from falling out of the area 12 of the screed arrangement 4 when the screed 5 is retracted, i.e., when the first screed 5 is moved in the retraction direction A′. In a second, position 13″ shown in dashed lines, the shielding element 13 is aligned at an angle α of 30° to 55° to the pulling direction Z in order to displace the paving material in the direction of a (virtual) central axis M of the screed arrangement 4. The shielding element 13 is preferably formed as high as the first extending screed 5. The shielding element 13 extends in pulling direction Z corresponding to a working depth 15 of the first extending screed 5.
[0050] FIG. 4 also shows that the first extending screed 5 has a shielding element 14 for the second extending screed 6. The shielding element 14 prevents paving material spread out in front of the extending screed 5 from being pushed beyond the width of the extending screed 5 when the extending screed 6 is retracted. The shielding element 14 is provided on the side of the extending screed 5′. It could, for example, be mounted as a rigid plate 14′″, possibly provided as part of the sideshift 5a formed on the extending screed 5. The shielding element 14 forms a wall extending in the pulling direction Z.
[0051] Furthermore, FIG. 4 shows in dashed representation a variant according to which the shielding element 14 is pivotally mounted on the sideshift 5a of the first extending screed 5 by means of a hinge 19′ relative to the sideshift 5a in order to further promote the displacement of the paving material from the area 12′ of the screed arrangement 4 during the retraction of the second extending screed 6 in the retraction direction A′. The shielding element 14 can be set between a first position 14′ and a second position 14″ via a hydraulic actuator (not shown). In the first position 14′, the shielding element 14 is substantially parallel to the pulling direction Z. In the second position 14″, the shielding element 14 is aligned with an angle α of 30° to 55° with respect to the pulling direction Z to displace the paving material in the direction of the central axis M of the screed arrangement 4 when the screed arrangement 4 is pulled in the pulling direction Z by the road paver.
[0052] FIG. 4 shows that the material deflecting member 10 together with the shielding element 13 as well as the material deflecting member 10′ together with the shielding element 14 form functional units on the screed arrangement 4 which can prevent jamming of paving material between the shielding element 13 of the base screed 7 and the extending screed 5 as well as between the sideshift 5a of the extending screed 5 and the further extending screed 6. As such, these functional units have a mirror-symmetrical structure offset in the pulling direction Z with respect to the central axis M.
[0053] FIG. 5 shows a perspective view of an extending screed 5, 6, wherein the working depth 15 and a working height 14 of the extending screed 5, 6 are shown.
[0054] FIG. 6 shows a further embodiment of a screed arrangement 4 in the extended position 17 of the extending screeds 5, 6, wherein each extending screed 5, 6 has a material deflecting member 10, 10′, and wherein a shielding element 22, 22′ arranged displaceably relative to the respective sideshifts 5a, 7a is provided on a sideshift 7a of the base screed 7 and on the sideshift 5a of the first extending screed 5.
[0055] FIG. 7 shows a further embodiment of a screed arrangement 4 in an extended position 17 of the extending screeds 5, 6, wherein each extending screed 5, 6 has a material deflecting member 10′, 10′″ pivotable relative to the respective extending screed bodies 5′, 6′. The material deflecting members 10″, 10′″ are pivotable about a hinge 23, 23′. A respective hydraulic drive (not shown) may be provided for this purpose.
[0056] In the embodiments shown, the respective material deflecting members 10, 10′, 10″, 10′″ and/or the shielding elements 13, 14, 22, 22′ may be formed as a heating plate, in particular as an electric heating plate.
[0057] FIGS. 2-4, 6 and 7 show a screed operator station B at the side of the base screed 7. The screed operator station B is positioned facing the first extending screed 5, in particular the area 12.
