Screed assembly with a functional connection between a height adjustment device for a screed plate carrier and a tilting device for a secondary screed plate mounted on the screed plate carrier

Abstract

To provide a screed assembly for a road paving machine.SOLUTION: A screed assembly (7) comprises: a main screed (15); and a sub-screed (17). The main screed (15) includes a main screed plate that comes into contact with a pavement material. The sub-screed (17) includes a screed plate carrier (27) and a sub-screed plate (21) that comes into contact with the pavement material. The sub-screed plate (21) is fitted to the screed plate carrier (27) so as to be able to tilt about a slope axis. The screed assembly (7) comprises a height adjustment device (31) configured to lower or raise the screed plate carrier (27) with respect to the main screed (15). The screed assembly (7) comprises a tilting device (45) configured to change the tilting angle of the sub-screed plate (21) about the slope axis.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a screed assembly for a road paver. [Background technology]

[0002] EP 2 199 467 A1 discloses a paving screed for a road paver, comprising a base screed and an extension screed. The extension screed is movable in the direction of movement relative to the base screed to vary the working width. The extension screeds are each supported by an extension guide structure on guides fixed to the base screed. Screed plates are arranged at the bottom of the base screed and the extension screed. The extension screed has a frame with a screed plate for the extension screed. A vertical adjustment device operable by a drive is provided between the extension guide structure and the frame of the extension screed to adjust the height of the frame relative to the extension guide structure.

[0003] Other paving screeds comprising a base screed and an extension screed which is displaceable relative to the base screed are known, for example from EP 1 031 660 A1, EP 2 199 466 A1 and EP 2 218 824 A1. Summary of the Invention [Problem to be solved by the invention]

[0004] According to one aspect of the present invention, there is provided a screed assembly for a road paver. The screed assembly comprises a main screed and a secondary screed. The main screed comprises a main screed plate that contacts the paving material. The secondary screed comprises a screed plate carrier and a secondary screed plate. The secondary screed plate is configured to contact the paving material. The secondary screed plate is attached to the screed plate carrier so as to be tiltable about a tilt axis. The screed assembly comprises a height adjustment device and a tilting device. The height adjustment device is configured to lower or raise the screed plate carrier relative to the main screed. The tilting device is configured to change the tilt angle of the secondary screed plate about the tilt axis. According to a first variant, the height adjustment device and the tilting device are operatively connected such that when the screed plate carrier is lowered or raised relative to the main screed by the height adjustment device, the tilting device is automatically activated to change the tilt angle of the secondary screed plate about the tilt axis. According to a second variant, the height adjustment device and the tilting device are functionally connected such that when the tilt angle of the secondary screed plate about the tilt axis is changed by the tilting device, the height adjustment device is automatically activated to lower or raise the screed plate carrier relative to the main screed. The functional connection of the height adjustment device and the tilting device can be configured according to the first and / or second variant.

[0005] The screed assembly may be configured to form a road paver together with a tow vehicle. The screed assembly may be mountable to a tow vehicle so as to be towed by the tow vehicle. The screed assembly may be configured to be towed behind the tow vehicle in the paving direction.

[0006] The screed assembly can be configured to compact paving material, particularly bituminous paving material, on a subgrade.The screed assembly can be configured to smooth paving material, particularly bituminous paving material, on a subgrade.

[0007] The cross direction is defined as the direction extending in a horizontal plane and perpendicular to the paving direction. The transverse or width direction can be the direction parallel to the cross direction.

[0008] The tilt axis can extend transversely to the paving direction. The tilt axis can extend parallel to the cross direction.

[0009] The secondary screed plate can extend at least partially laterally outward of the primary screed plate. The secondary screed can be configured to provide a wider paving width compared to the paving width of the primary screed.

[0010] The secondary screed may be configured to be displaceable transversely relative to the main screed. The secondary screed may be configured as an extension that extends transversely outward from the main screed to increase the overall paving width of the screed assembly. The screed assembly may include a screed width adjuster configured to move the secondary screed transversely relative to the main screed.

[0011] As an alternative to the secondary screed being transversely movable relative to the main screed, the secondary screed can be attached to the main screed so that it is not transversely movable, and at least a part of the secondary screed can be fixedly connected to the main screed.

[0012] The secondary screed can be positioned completely or partially in front of the main screed in the paving direction. The secondary screed can be positioned completely or partially behind the main screed in the paving direction. The secondary screed can extend beyond the main screed along the paving direction. The secondary screed can extend beyond the main screed in the direction opposite to the paving direction.

[0013] The secondary screed plate can be positioned completely or partially in front of the main screed plate in the paving direction. The secondary screed plate can be positioned completely or partially behind the main screed plate in the paving direction. The main and secondary screed plates can be positioned strictly behind each other (without overlapping) or overlapping along the paving direction. The secondary screed plate can be directly connected to the main screed plate along the paving direction or in the opposite direction. The distance between the main and secondary screed plates along the paving direction can be, for example, less than 50 cm, or less than 20 cm, or less than 10 cm, or less than 5 cm, or between 15 cm and 90 cm. In particular, the distance between the main and secondary screed plates along the paving direction can include, for example, 20 cm, 40 cm, 55 cm, or 85 cm.

[0014] The length of the primary screed plate along the paving direction may be different from the length of the secondary screed plate along the paving direction. The length of the secondary screed plate along the paving direction can be shorter than the length of the primary screed plate along the paving direction. The length of the secondary screed plate along the paving direction can be at most 80%, or at most 70%, or at most 60%, or at most 50% of the length of the primary screed plate along the paving direction. The length of the secondary screed plate along the paving direction can be at least 20%, or at least 30%, or at least 40%, or at least 50% of the length of the primary screed plate along the paving direction. The length of the secondary screed plate along the paving direction can be 30% to 70%, or 40% to 60%, or 45% to 55% of the length of the primary screed plate along the paving direction. The length of the secondary screed plate along the paving direction can be at least substantially 50% of the length of the primary screed plate along the paving direction.

[0015] The length of the primary screed plate along the paving direction may at least substantially correspond to the length of the secondary screed plate along the paving direction.

[0016] The length of the primary screed plate along the paving direction may be shorter than the length of the secondary screed plate along the paving direction.

[0017] The secondary screed can be configured to be tilted as a whole about an axis extending parallel to the paving direction. The secondary screed can be configured to be tilted relative to the main screed about an axis extending parallel to the paving direction. Tilting the secondary screed about an axis extending parallel to the paving direction can simplify the application of roof profiles or sloped road surfaces, for example.

[0018] The screed assembly may be configured to be tiltable as a whole about a general axis extending parallel to the cross direction. The tilt position of the screed assembly as a whole about the general axis may define an angle of attack of the main screed plate relative to the horizontal plane. The angle of attack of the main screed plate may affect the degree of compaction by the main screed. A larger angle of attack of the main screed plate may result in a greater degree of compaction.

[0019] When the screed assembly is tilted about its overall axis, a height offset can occur between the rear edges of the primary and secondary screed plates. This height offset can result in undesirable offsets in the laid pavement during paving operations. The height adjustment device can be used to lower or raise the screed plate carrier of the secondary screed relative to the primary screed to compensate for the height offset between the rear edges of the primary and secondary screed plates.

[0020] When the screed plate carrier is lowered or raised by the height adjustment device, the tilt axis can also be lowered or raised. When the screed plate carrier is lowered or raised by the height adjustment device, the secondary screed plate can also be lowered or raised. The height adjustment device can be configured to lower or raise the screed plate carrier, secondary screed plate and tilt axis together relative to the main screed. The height adjustment device can be configured to lower or raise the screed plate carrier, secondary screed plate and tilt axis together as a unit relative to the main screed.

[0021] The height difference between the leading edge of the primary screed plate and the trailing edge of the primary screed plate may be referred to as the primary screed retraction height.The height difference between the leading edge of the secondary screed plate and the trailing edge of the secondary screed plate may be referred to as the secondary screed retraction height.

[0022] For example, tilting the screed assembly as a whole about its overall axis and / or raising or lowering the screed plate carrier relative to the main screed by means of a height adjustment device can result in a retracted height of the secondary screed plate that is different from the retracted height of the main screed plate, which can undesirably result in different degrees of compaction of the paving material in the area of ​​the main screed and the area of ​​the secondary screed.

[0023] The tilting device may be configured to vary the angle of attack of the secondary screed plate by varying the tilt angle of the secondary screed plate about the tilt axis. The tilting device may be configured to vary the retracted height of the secondary screed plate by varying the tilt angle of the secondary screed plate about the tilt axis, in particular to match the retracted height of the primary screed plate. The tilting device may be configured to vary the angle of attack of the secondary screed plate by varying the tilt angle of the secondary screed plate about the tilt axis, and therefore also to vary the retracted height of the secondary screed plate.

[0024] The coupling of the height adjustment device and the tilting device makes it possible to simplify the adjustment process of the secondary screed during operation. By coupling the height adjustment device and the tilting device, it is possible to avoid or reduce operating errors.

[0025] The height adjustment device and the tilting device can be connected in such a way that the lowering or raising of the screed plate carrier relative to the main screed by the height adjustment device and the associated change in the inclination angle of the secondary screed plate by the tilting device are performed simultaneously.The height adjustment device and the tilting device can be connected in such a way that the change in the inclination angle of the secondary screed plate by the tilting device and the associated lowering or raising of the screed plate carrier relative to the main screed are performed simultaneously by the height adjustment device.If the lowering or raising of the screed plate carrier relative to the main screed and the change in the inclination angle of the secondary screed plate about the tilt axis are performed simultaneously, the time required for the adjustment process of the secondary screed plate can be shortened, which makes it possible to achieve, in particular, improved paving results.

[0026] The height adjustment device and the tilting device can be connected so that the lowering or raising of the screed plate carrier relative to the main screed by the height adjustment device is at a constant ratio to the change in the tilt angle of the secondary screed plate about the tilt axis by the tilting device, which constant ratio can be suitably selected based on the geometric shapes of the main and secondary screeds and their mutual arrangement.

[0027] The height adjustment device and tilting device may be connected so that when the screed plate carrier is lowered or raised relative to the main screed by the height adjustment device, the tilting device automatically operates to change the angle of tilt of the secondary screed plate about the tilt axis so that the difference between the retracted height of the main screed plate and the retracted height of the secondary screed plate is partially or fully compensated.

[0028] The automatic activation of the tilting device when the screed plate carrier is lowered or raised relative to the main screed simplifies the adjustment process of the secondary screed during operation. Due to the height adjustment device being coupled to the tilting device, lowering or raising of the screed plate carrier relative to the main screed can always change the tilt angle of the secondary screed plate about the tilt axis. Individual setting of the tilt angle of the secondary screed plate about the tilt axis can be omitted or simplified.

[0029] In particular, when the secondary screed plate is located completely or partially in front of the main screed plate in the paving direction, the height adjustment device and the tilting device can be coupled so that lowering the screed plate carrier by the height adjustment device activates the tilting device for tilting the secondary screed plate about the tilt axis, thereby increasing the angle of attack of the secondary screed plate with respect to the subgrade.In particular, when the secondary screed plate is located completely or partially in front of the main screed plate in the paving direction, the height adjustment device and the tilting device can be coupled so that raising the screed plate carrier by the height adjustment device activates the tilting device for tilting the secondary screed plate about the tilt axis, thereby decreasing the angle of attack of the secondary screed plate with respect to the subgrade.

[0030] In particular, when the secondary screed plate is located completely or partially behind the main screed plate in the paving direction, the height adjustment device and the tilting device can be coupled so that lowering the screed plate carrier by the height adjustment device activates the tilting device for tilting the secondary screed plate about the tilt axis, thereby reducing the angle of attack of the secondary screed plate with respect to the subgrade.In particular, when the secondary screed plate is located completely or partially behind the main screed plate in the paving direction, the height adjustment device and the tilting device can be coupled so that raising the screed plate carrier by the height adjustment device activates the tilting device for tilting the secondary screed plate about the tilt axis, thereby increasing the angle of attack of the secondary screed plate with respect to the subgrade.

[0031] The height adjustment device and tilting device can be connected to lower or raise the screed plate carrier relative to the main screed so that when the tilt angle of the secondary screed plate around the tilt axis is changed by the tilting device, the height adjustment device is automatically activated to partially or fully compensate for the height difference between the rear edge of the main screed plate and the rear edge of the secondary screed plate.

[0032] The automatic operation of the height adjustment device when changing the tilt angle of the screed plate about the tilt axis simplifies the adjustment process of the screed plate during operation. The height adjustment device is coupled to the tilting device so that changing the tilt angle of the secondary screed plate about the tilt axis always results in immediate lowering or raising of the screed plate carrier relative to the main screed. Separate lowering or raising of the screed plate carrier relative to the main screed can be omitted or simplified.

[0033] In particular, when the secondary screed plate is located completely or partially in front of the main screed plate in the paving direction, the height adjustment device and the tilting device can be connected in such a way that the height adjustment device is actuated to lower the screed plate carrier by tilting the secondary screed plate about the tilt axis so that the angle of attack of the secondary screed plate with respect to the subgrade is increased by the tilting device.In particular, when the secondary screed plate is located completely or partially in front of the main screed plate in the laying direction, the height adjustment device and the tilting device can be connected in such a way that the height adjustment device is actuated to raise the screed plate carrier by tilting the secondary screed plate about the tilt axis so that the angle of attack of the secondary screed plate with respect to the subgrade is reduced by the tilting device.

[0034] In particular, when the secondary screed plate is located completely or partially behind the main screed plate in the paving direction, the height adjustment device and the tilting device can be connected in such a way that the height adjustment device is actuated to lower the screed plate carrier by tilting the secondary screed plate about the tilt axis so that the angle of attack of the secondary screed plate with respect to the subgrade is reduced by the tilting device.In particular, when the secondary screed plate is located completely or partially behind the main screed plate in the laying direction, the height adjustment device and the tilting device can be connected in such a way that the height adjustment device is actuated to raise the screed plate carrier by tilting the secondary screed plate about the tilt axis so that the angle of attack of the secondary screed plate with respect to the subgrade is increased by the tilting device.

[0035] Preferably, the area of ​​the secondary screed plate located rearward in the paving direction is attached to the tilt axis. For example, the connection between the tilt axis and the secondary screed plate can be located 20%, 10%, or 5% rearward of the length of the secondary screed plate in the paving direction. The further rearward the secondary screed plate is attached to the tilt axis, the smaller the change in height of its rear edge when the tilt angle of the secondary screed plate around the tilt axis is changed.

[0036] The tilting device may be configured to raise or lower an end of the secondary screed plate opposite the tilt axis to change the tilt angle of the secondary screed plate relative to the screed plate carrier. The end of the secondary screed plate opposite the tilt axis may be a front end of the secondary screed plate relative to the laying direction. By raising or lowering the front end of the secondary screed plate, the degree of compaction achieved by the secondary screed can be changed.

[0037] The tilting device may include an actuation connection which may be connected to the secondary screed plate and which may be configured to automatically rotate the secondary screed plate about the tilt axis when the screed plate carrier is lowered or raised by the height adjustment device.

[0038] The operational connection is connectable to a front region, in particular a front end, of the secondary screed plate relative to the paving direction.

[0039] The connection point of the secondary screed plate with the working connection may be spaced apart from the connection point of the secondary screed plate with the tilt axis along the paving direction or vice versa, in particular by at least 80%, or at least 70%, or at least 50%, or at least 40%, or at least 30% of the length of the secondary screed plate along the paving direction. Due to the leverage effect, the spaced apart connection points may favour the transmission of forces to the secondary screed plate via the working connection for changing the tilt angle of the secondary screed plate about the tilt axis.

[0040] The height adjustment device and tilting device can be connected such that lowering or raising the screed plate carrier by the carrier adjustment length relative to the primary screed causes the tilting device to be actuated to lower or raise the front end of the secondary screed plate by the screed plate adjustment length relative to the screed plate carrier.

[0041] The height adjustment device and tilting device can be connected such that lowering or raising the front end of the secondary screed plate relative to the screed plate carrier by the screed plate adjustment length activates the height adjustment device to lower or raise the screed plate carrier relative to the primary screed by the carrier adjustment length.

[0042] The screed plate adjustment length can be proportional to the carrier adjustment length.

[0043] The proportionality coefficient between the screed plate adjustment length and the carrier adjustment length can be selected so that when the screed plate carrier is lowered or raised by the height adjustment device by the carrier adjustment length, the front end of the secondary screed plate is lowered or raised, thereby adjusting the retracted height of the secondary screed plate to the retracted height of the main screed plate.

[0044] The proportionality coefficient between the screed plate adjustment length and the carrier adjustment length can be selected so that when the front end of the secondary screed plate is lowered or raised, the height of the rear edge of the secondary screed plate is adjusted to the height of the rear edge of the main screed plate by lowering or raising the screed plate carrier.

[0045] The proportionality factor between the carrier adjustment length and the screed plate adjustment length can at least substantially correspond to the ratio between the length of the primary screed plate in the paving direction and the length of the secondary screed plate in the paving direction. For example, if the length of the primary screed plate in the paving direction corresponds to twice the length of the secondary screed plate in the paving direction, the carrier adjustment length can correspond to twice the screed plate adjustment length. In particular, the secondary screed plate can be directly connected to the primary screed plate along the paving direction.

[0046] The screed assembly may comprise a drive, which may be configured to lower or raise the screed plate carrier relative to the main screed, and which may comprise, for example, a spindle drive.

[0047] The drive can be coupled to the tilt device. The drive can drive the tilt device. If the drive drives both the height adjustment device and the tilt device, the height adjustment device can be coupled to the tilt device in a particularly cost-effective, efficient and reliable manner.

[0048] The drive device may be configured to drive the height adjustment device with a first transmission ratio. The drive device may be configured to drive the tilting device with a second transmission ratio. The first transmission ratio may be different from the second transmission ratio. The first transmission ratio and / or the second transmission ratio may be adaptive, in particular adjustable. The first transmission ratio and / or the second transmission ratio may be adjustable according to installation conditions or default values.

[0049] The functional connection between the height adjustment device and the tilt device may comprise a mechanical connection. Alternatively, or additionally, the functional connection between the height adjustment device and the tilt device may comprise a non-mechanical connection.

[0050] The functional coupling between the height adjustment device and the tilt device may include a coupling implemented in a control system. The coupling implemented in the control technology may, for example, activate the height adjustment device and, additionally, the tilt device based on a user input for controlling the height adjustment device. The coupling implemented in the control technology may, for example, activate the tilt device and, additionally, the height adjustment device based on a user input for controlling the tilt device. The coupling implemented in the control system may, for example, activate both the height adjustment device and the tilt device based on a user input, in particular a single user input, and in particular activate them cooperatively. Separate activation of the height adjustment device and the tilt device by separate user inputs may be omitted.

[0051] The functional connection between the height adjustment device and the tilt device may include an electronic connection or a hydraulic connection.

[0052] The height adjustment device may be configured to increase the distance between the support frame and a support structure provided at a fixed height relative to the main screed by a first length, and in particular simultaneously increase the distance between the support frame and the screed plate carrier by a second length, in order to lower the screed plate carrier relative to the main screed. The height adjustment device may be configured to decrease the distance between the support frame and the support structure by a third length, and in particular simultaneously decrease the distance between the support frame and the screed plate carrier by a fourth length, in order to raise the screed plate carrier relative to the main screed. The ratio of the first length to the second length may correspond to the ratio of the third length to the fourth length.

[0053] The tilting device may include an actuation connection, which may connect the support frame to the secondary screed plate.

[0054] The operational connection may be connected to the support frame at a first connection point. The operational connection may be connected to the secondary screed plate at a second connection point. The operational connection may connect the support frame to the secondary screed plate such that a constant distance is maintained between the first and second connection points.

[0055] When the height adjustment device lowers the screed plate carrier relative to the main screed, the second connection point can be raised relative to the screed plate carrier by a distance corresponding to the second length.When the height adjustment device raises the screed plate carrier relative to the main screed, the second connection point can be lowered by a distance corresponding to the second length.

[0056] The ratio of the first length to the second length may be 1:1.

[0057] The screed assembly may include an inclination adjustment device that allows the inclination angle of the secondary screed plate about the inclination axis to be changed without operating the height adjustment device. The inclination adjustment device allows the inclination angle of the secondary screed plate to be readjusted about the inclination axis, for example to adjust the inclination angle of the secondary screed plate relative to the subgrade. The inclination adjustment device allows the inclination angle of the secondary screed plate to be set offset about the inclination axis.

[0058] According to a further aspect of the present invention, there is provided a road paver comprising a towing vehicle and the screed assembly as described above. The towing vehicle may comprise a hopper for receiving paving material. Preferably, the hopper is located forward of the towing vehicle in the paving direction. Preferably, the screed assembly is mounted rearward of the towing vehicle in the paving direction.

[0059] The road paver may comprise a material handling device configured to transport paving material from a hopper backward, opposite to the paving direction, and to provide the paving material to the paving screed. The road paver may comprise a lateral distribution device, in particular a distribution auger, configured to distribute the paving material transversely in front of the paving screed.

[0060] The present invention will be described in more detail below with reference to embodiments. [Brief explanation of the drawings]

[0061] [Figure 1] FIG. 1 shows a schematic side view of a road paver including a screed assembly according to one embodiment. [Figure 2] FIG. 2 shows a schematic top view of a screed assembly according to one embodiment. [Figure 3] FIG. 3 shows a schematic perspective view of a screed assembly according to one embodiment. [Figure 4] Figure 4 shows a schematic view of the screed assembly of the embodiment shown in Figure 3 in the region of the secondary screed, seen from the direction opposite to the paving direction. [Figure 5] FIG. 5 shows a schematic view of the screed assembly of the embodiment shown in FIG. 3 in the region of the secondary screed, viewed laterally towards the screed assembly. [Figure 6] FIG. 6 is a schematic diagram illustrating the adjustment process for a screed assembly according to one embodiment. [Figure 7] FIG. 7 shows a schematic view of a screed assembly according to an alternative embodiment, viewed from the opposite direction to the paving direction. [Figure 8] FIG. 8 shows a schematic view of a screed assembly according to a further alternative embodiment, viewed from the opposite direction to the paving direction. [Figure 9] FIG. 9 shows a schematic view of a screed assembly according to a further alternative embodiment, viewed from the opposite direction to the paving direction. [Figure 10] FIG. 10 shows a schematic diagram of a screed assembly according to a further alternative embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0062] Figure 1 shows a road paver 1 according to one embodiment. The road paver 1 comprises a tow vehicle 3 and a screed assembly 7 that is towed behind the tow vehicle 3 via a tow bar 5. The screed assembly 7 is shown schematically in Figure 1 and can be configured according to any of the described embodiments.

[0063] The towing vehicle 3 is provided with a hopper 11 located ahead in the paving direction 9 for receiving the paving material. The paving material is transported backwards, counter to the paving direction 9, by a material handling device of the towing vehicle 3 and provided to the screed assembly 7. A lateral distributor 13 in the form of a distribution auger is provided behind the towing vehicle 3, which distributes the paving material ahead of the screed assembly 7 along a transverse direction 14 parallel to the horizontal plane and perpendicular to the paving direction 9.

[0064] FIG. 2 shows a schematic top view of a screed assembly 7 according to one embodiment. The screed assembly 7 comprises a primary screed 15 and two secondary screeds 17. In the illustrated embodiment, the screed assembly 7 is configured as an extending screed assembly. The secondary screeds 17 are displaceable along the transverse direction 14 relative to the primary screed 15 to vary the overall screed assembly width of the screed assembly 7. In FIG. 2, the secondary screed 17 on the right side, as viewed along the paving direction 9, is shown in a fully retracted position, which does not increase the overall screed assembly width of the screed assembly 7. The secondary screed 17 on the left side, as viewed along the paving direction 9, is shown in an extended position, which increases the overall screed assembly width of the screed assembly 7. Intermediate positions are also contemplated.

[0065] In the embodiment shown in Figure 2, the secondary screed 17 is positioned in front of the main screed 15 relative to the paving direction 9. Alternatively, the secondary screed 17 can be positioned behind the main screed 15 relative to the paving direction 9 or at least partially adjacent to the main screed 15.

[0066] Figure 3 shows a schematic perspective view of a screed assembly 7 according to one embodiment, viewed opposite the paving direction 9. The screed assembly 7 is in the configuration shown in Figure 2, i.e. the secondary screed 17 on the left side as viewed along the paving direction 9 extends laterally and the secondary screed 17 on the right side as viewed along the paving direction 9 does not extend. Figure 3 shows a displacement device 19 which makes it possible to move the secondary screed 17 along the cross direction 14.

[0067] Each secondary screed 17 comprises a secondary screed plate 21 which contacts the paving material to compact and smooth it. Correspondingly, the primary screed 15 comprises a primary screed plate 23 which contacts the paving material to compact and smooth it. In the illustrated embodiment, the length of the primary screed screed plates 23 in the paving direction 9 corresponds to twice the length of the secondary screed plates 21 in the paving direction 9.

[0068] 4 shows a schematic view of the screed assembly 7 in the region of the extended secondary screed 17, seen opposite the paving direction 9. The secondary screed 17 comprises a support structure 25, which is provided at a fixed height relative to the main screed 15. In addition, the secondary screed 17 comprises a screed plate carrier 27, to which the secondary screed plate 21 is attached. The screed plate carrier 27 is guided via a guide structure 29 so as to be height-adjustable relative to the support structure 25 and thus relative to the main screed 15. A height adjustment device 31 enables the screed plate carrier 27 to be raised and lowered relative to the support structure 25 and thus relative to the main screed 15. The height adjustment device 31 comprises a drive device 33 in the form of a motor, which synchronously drives two identical spindle devices 35 by means of a chain. The drive device 33 is mounted on a support frame 37. The spindles 35 are each configured as a reverse threaded spindle that connects the screed plate carrier 27 and the support structure 25 to each other.

[0069] To lower the screed plate carrier 27 relative to the main screed 15, the drive 33 drives the spindle 35 to increase the distance between the screed plate carrier 27 and the support frame 37 and the distance between the support frame 37 and the support structure 25. As the distance between the support frame 37 and the support structure 25 increases by a first length, the distance between the support frame 37 and the screed plate carrier 27 increases by a second length. The ratio between the first length and the second length results from the thread ratio of the corresponding spindle portions, which in the illustrated embodiment is 1:1.

[0070] To raise the screed plate carrier 27 relative to the support structure 25, and therefore relative to the main screed 15, the drive 33 drives the spindle 35 to decrease the distance between the support frame 37 and the support structure 25 and the distance between the support frame 37 and the screed plate carrier 27. When the distance between the support frame 37 and the support structure 25 decreases by a third length, the distance between the support frame 37 and the screed plate carrier 27 decreases by a fourth length. The ratio between the third length and the fourth length results from the thread ratio of the corresponding spindle portions, which in the illustrated embodiment is 1:1.

[0071] Figure 5 shows a schematic side view of the screed assembly 7 as seen along the transverse direction 14. As can be seen from Figure 5, the screed assembly 7 can be tilted as a whole about a general axis extending parallel to the transverse direction 14 by means of tilt adjustment means 39. The secondary screed plate 21 is mounted on the screed plate carrier 27 so as to be tiltable about a tilt axis 41. The connection between the secondary screed plate 21 and the tilt axis 41 is located in the rear region of the secondary screed plate 21 relative to the paving direction 9.

[0072] As shown in Figure 4, the support frame 37 and the secondary screed plate 21 are connected to each other by two identically configured actuated connections 43. In particular, the front region of the screed plate 21 relative to the paving direction 9 is connected to the support frame 37 via the actuated connection 43. The actuated connection 43 represents a tilting device 45 that makes it possible to tilt the secondary screed plate 21 about a tilt axis 41.

[0073] The operating connection 43 is connected to the support frame 37, thereby connecting the height adjustment device 31 and the tilt device 45.

[0074] When the screed plate carrier 27 is lowered by the height adjustment device 31, the support frame 37 moves downwards by a first length relative to the support structure 25. Accordingly, the front region of the secondary screed plate 21, which is connected to the support frame 37 via the operational connection 43, also moves downwards by the first length relative to the support structure 25. On the other hand, the screed plate carrier 21 and the tilt axis 41, and therefore the rear end of the secondary screed plate 21, also move downwards by the sum of the first length and the second length relative to the paving direction 9. This causes the front end of the secondary screed plate 21 to rise by the second length relative to the rear end of the secondary screed plate 21. When the screed plate carrier 27 is lowered, this simultaneously tilts the secondary screed plate 21 about the tilt axis 41, increasing the angle of attack between the secondary screed plate 21 and the horizontal surface or subgrade.

[0075] When the screed plate carrier 27 is raised by the height adjustment device 31, the support frame 37 moves upward by a third length relative to the support structure 25. Accordingly, the front region of the secondary screed plate 21, which is connected to the support frame 37 via the operational connection 43, also moves upward by the third length relative to the support structure 25. On the other hand, the screed plate carrier 21 and the tilt axis 41, and therefore the rear end of the secondary screed plate 21, also move upward by the sum of the third length and the fourth length relative to the paving direction 9. This causes the front end of the secondary screed plate 21 to descend by the fourth length relative to the rear end of the secondary screed plate 21. When the screed plate carrier 27 is raised, this simultaneously tilts the secondary screed plate 21 about the tilt axis 41, thereby reducing the angle of attack between the secondary screed plate 21 and the horizontal surface or subgrade.

[0076] Figure 6 is a schematic diagram illustrating the application of the present invention in a paving process. In part A of Figure 6, the paving process is performed in an equilibrium state. Paving material is laid on the subgrade 47, with the laid pavement having a height level 49 behind the screed assembly 7. The height level 49 is defined by the height of the rear edge 51 of the main screed plate 23 and the height of the rear edge 53 of the secondary screed plate 21. In the equilibrium state shown in part A of Figure 6, the rear edge 51 of the main screed plate 23 and the rear edge 53 of the secondary screed plate 21 are at the same height. In part A of Figure 6, the front edge 55 of the main screed plate 23 and the front edge 57 of the secondary screed plate 21 are also at a common height level, i.e., height level 59, so that at least substantially the same compaction is obtained in the area of ​​the main screed 15 and the area of ​​the secondary screed 17.

[0077] Part B of Figure 6 shows the situation after the screed assembly 7 has been rotated about its global axis extending parallel to the transverse direction 14. This can occur, for example, due to a change in the properties of the paving material or a change in the paving thickness. Due to the global tilt of the screed assembly 7, the rear edge 51 of the main screed plate 23 and the rear edge 53 of the secondary screed plate 21 are no longer at the same height level. In the situation shown, the rear edge 51 of the main screed plate 23 is located at a height level 61 higher than the height level 63 at which the rear edge 53 of the secondary screed plate 21 is located. This results in a step change in the paving layer.

[0078] By operating the height adjustment device 31 to raise the screed plate carrier 27, the rear edge 53 of the secondary screed plate 21 can be brought to the height level 61 of the rear edge 51 of the main screed plate 23, thereby forming a flat surface again. As explained above, when the screed plate carrier 27 is raised, both secondary screed plates 21 rise as a whole (arrow 65 in part B of FIG. 6 ), and the secondary screed plates 21 tilt about the tilt axis 41 due to the connection between the height adjustment device 31 and the tilting device 45, thereby reducing the angle of attack of the secondary screed plates 21 with respect to the subgrade 47 (arrow 67 in part B of FIG. 6 ). The tilt axis 41 is located substantially in the area of ​​the rear edge 53 of the secondary screed plates.

[0079] Part C of Figure 6 shows the situation after the screed plate carrier 27 has been raised by the height adjustment device 31. The rear edge 53 of the secondary screed plate 21 has been raised to the height level 61 of the rear edge 51 of the main screed plate 23. At the same time, the secondary screed plate 21 has been tilted about the tilt axis 41 so that the front edge 57 of the secondary screed plate 21 is at the same height level 69 as the front edge 55 of the main screed plate 23. This again provides a flat surface and at least substantially constant compaction.

[0080] FIG. 7 shows an alternative embodiment. The embodiment shown in FIG. 7 substantially corresponds in function and structure to the embodiment shown in FIGS. 3 to 5. For clarity, only the differences from the embodiment shown in FIGS. 3 to 5 will be described. In the embodiment shown in FIG. 7, a tilt adjustment device 71 is provided between the operating connection 43 and the support frame 37. The tilt adjustment device 71 allows the height of the operating connection 43 to be adjusted relative to the support frame 37 via a threaded rod 72 and a rocker 74. The tilt adjustment device 71 therefore allows the tilt angle of the secondary screed plate 21 around the tilt axis 41 to be changed, especially without manually operating the height adjustment device 31. The tilt adjustment device 71 can be used, for example, to correct the tilt angle of the secondary screed plate 21.

[0081] Figure 8 shows a further alternative embodiment. The embodiment shown in Figure 8 substantially corresponds to the embodiment shown in Figure 7 in terms of its function and structure. For the sake of clarity, only the differences from the embodiment shown in Figure 7 will be described. The embodiment shown in Figure 8 also includes an inclination adjustment device 71, which allows the angle of inclination of the secondary screed plate 21 about the inclination axis 41 to be changed, in particular manually, without actuating the height adjustment device 31. In the embodiment shown in Figure 8, however, this is not achieved by adjusting the height of the actuating connection 43 relative to the support frame 37, but by tilting the actuating connection 43 from the vertical. The inclination adjustment device 71 comprises a threaded rod 72 mounted in a bearing 76 for movement along the transverse direction 14. The actuating connection 43 is articulated with the threaded rod 72 at an articulation point 78 so as to be rotatable about an axis extending parallel to the paving direction 9. When the threaded rod 72 moves along the transverse direction 14, the articulation point 78 is displaced along the transverse direction 14, which causes the operating connection 43 to tilt relative to the vertical and, since the operating connection 43 has a certain length, causes the front region of the secondary screed plate 21 to be raised or lowered relative to the support frame 37.

[0082] Figure 9 shows a further alternative embodiment. The embodiment shown in Figure 9 substantially corresponds in function and structure to the embodiment shown in Figures 3 to 5. For clarity, only the differences from the embodiment shown in Figures 3 to 5 will be described. In the embodiment shown in Figure 9, the operational connection 43 between the support frame 37 and the front region of the secondary screed plate 21 is absent. Instead, an operational connection 81 is provided, connecting the front region of the secondary screed plate 21 to the support structure 25. The operational connection 81 is the tilting device 45. The operational connection 81 comprises a lever device 83 having a lever 85 connected to the screed plate carrier 27 via an articulation. When the screed plate carrier 27 is lowered or raised by the height adjustment device 31, the position of the lever device 83 changes so that the front region of the secondary screed plate 21 is raised or lowered as the distance between the support structure 25 and the screed plate carrier 27 changes. The configuration of the lever device 83, which is adapted to the geometry of the screed assembly 7, ensures that when the screed plate carrier 27 is lowered or raised relative to the main screed 15 by the height adjustment device 31, the tilting device 45 is automatically activated to vary the tilt angle of the secondary screed plate 21 about the tilt axis 41, so that the difference between the retracted height of the main screed plate 23 and the retracted height of the secondary screed plate 21 is partially or completely compensated.

[0083] In the above embodiments, the connection between the height adjustment device 31 and the tilting device 45 is mechanical. Figure 10 shows schematically an alternative embodiment in which the height adjustment of the screed plate carrier 27 relative to the main screed 15 is non-mechanically connected to the adjustment of the tilt angle of the secondary screed plate 21 about the tilt axis 41.

[0084] In the embodiment of Figure 10, the tilting device 45 comprises a drive 80 for varying the tilt angle of the secondary screed plate 21 about the tilt axis 41. In addition, a height adjustment device 31 is provided with a drive 82 for lowering or raising the screed plate carrier 27 relative to the main screed 15. The drives 80, 82 are controlled by a control device 84, which can be, for example, electronic or hydraulic.

[0085] The embodiment according to Figure 10 is operable such that the controller 84 receives operator input to lower or raise the screed plate carrier 27 relative to the primary screed 15. In accordance with the operator input, the controller 84 is operable to control the height adjustment device 31. Additionally, the controller 84 is operable to automatically control the tilt device 45 to tilt the secondary screed plate 21 based on the same operator input.

[0086] According to another variation, the controller 84 can receive operator input to adjust the tilt angle of the secondary screed plate 21 about the tilt axis 41. Based on the operator input, the controller 84 can control the tilting device 45 to change the tilt angle. In addition, based on the same operator input, the controller 84 can control the height adjustment device 31 to raise or lower the screed plate carrier 27 relative to the primary screed 15.

[0087] The ratio of the change in height of the screed plate carrier 27 relative to the main screed 15 to the change in the inclination angle can be predetermined, in particular variably predetermined.

Claims

1. a main screed (15) having a main screed plate (23) in contact with the paving material; and a secondary screed (17) having a screed plate carrier (27) and a secondary screed plate (21) in contact with the paving material; A screed assembly (7) for a road paver (1), comprising: The secondary screed plate (21) is mounted on the screed plate carrier (27) so as to be tiltable about a tilt axis (41); the screed assembly (7) comprising a height adjustment device (31) configured to lower or raise the screed plate carrier (27) relative to the main screed (15); The screed assembly (7) comprises a tilting device (45) configured to vary the tilt angle of the secondary screed plate (21) around the tilt axis (41); and The height adjustment device (31) and the tilt device (45) a) the tilting device (45) is operatively connected to automatically operate to change the tilt angle of the secondary screed plate (21) about the tilt axis (41) when the screed plate carrier (27) is lowered or raised relative to the primary screed (15) by the height adjustment device (31); and / or b) a screed assembly (7) for a road paver (1), wherein the height adjustment device (31) is operatively connected to automatically operate to lower or raise the screed plate carrier (27) relative to the main screed (15) when the tilt angle of the secondary screed plate (21) about the tilt axis (41) is changed by the tilting device (45).

2. 2. The screed assembly according to claim 1, wherein the inclined axis (41) extends transversely to the paving direction (9).

3. 3. The screed assembly according to claim 1 or 2, wherein lowering the screed plate carrier (27) by means of the height adjustment device (31) activates the tilting device (45) for tilting the secondary screed plate (21) about the tilt axis (41) to increase the angle of attack of the secondary screed plate (21) with respect to the subgrade (47), and / or raising the screed plate carrier (27) by means of the height adjustment device (31) activates the tilting device (45) for tilting the secondary screed plate (21) about the tilt axis (41) to decrease the angle of attack of the secondary screed plate (21) with respect to the subgrade (47).

4. 3. The screed assembly according to claim 1, wherein the tilting device (45) for tilting the secondary screed plate (21) about the tilt axis (41) is activated by lowering the screed plate carrier (27) using the height adjustment device (31), thereby reducing the angle of attack of the secondary screed plate (21) with respect to the subgrade (47), and / or the tilting device (45) for tilting the secondary screed plate (21) about the tilt axis (41) is activated by raising the screed plate carrier (27) using the height adjustment device (31), thereby increasing the angle of attack of the secondary screed plate (21) with respect to the subgrade (47).

5. 5. The screed assembly according to any one of claims 1 to 4, wherein the area of ​​the secondary screed plate (21) located rearward in the paving direction (9) is attached to the tilt axis (41).

6. 6. The screed assembly according to claim 1, wherein the tilting device (45) is configured to raise or lower an end of the secondary screed plate (21) opposite the tilt axis (41) to change the tilt angle of the secondary screed plate (21) relative to the screed plate carrier (27).

7. 7. The screed assembly according to claim 1, wherein the tilting device (45) comprises an actuation connection (43) connected to the secondary screed plate (21), the actuation connection (43) being configured to automatically rotate the secondary screed plate (21) about the tilting axis (41) when the screed plate carrier (27) is lowered or raised by the height adjustment device (31).

8. 8. A screed assembly according to claim 7, wherein the operational connection (43) is connected to a front region, in particular a front end, of the secondary screed plate (21) relative to the paving direction (9).

9. 9. A screed assembly according to any one of claims 1 to 8, wherein the tilting device (45) is actuated by lowering or raising the screed plate carrier (27) relative to the main screed (15) by a carrier adjustment length, thereby lowering or raising the front end of the secondary screed plate (21) relative to the screed plate carrier (27) by a screed plate adjustment length, the screed plate adjustment length being proportional to the carrier adjustment length.

10. 10. The screed assembly according to claim 9, wherein the proportionality factor between the carrier adjustment length and the screed plate adjustment length corresponds at least substantially to the ratio between the length of the main screed plate (23) in the paving direction (9) and the length of the secondary screed plate (21) in the paving direction (9).

11. 11. The screed assembly (7) according to any one of claims 1 to 10, wherein the screed assembly (7) comprises a drive (33) configured to lower or raise the screed plate carrier (27) relative to the main screed (15).

12. 12. The screed assembly of claim 11, wherein the drive device (33) is coupled to and drives the tilting device (45).

13. 13. The screed assembly according to claim 12, wherein the drive device (33) drives the height adjustment device (31) with a first transmission ratio and drives the tilting device (45) with a second transmission ratio different from the first transmission ratio.

14. 14. The screed assembly according to any one of claims 1 to 13, further comprising a tilt adjustment device (71) that makes it possible to change the tilt angle of the secondary screed plate (21) about the tilt axis (41) without actuating the height adjustment device (31).

15. a towing vehicle (3) positioned ahead in the paving direction (9) and having a hopper (11) for storing paving material; and A screed assembly (7) according to any one of claims 1 to 14, mounted behind the towing vehicle (3) in the paving direction (9). A road paver (1).

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