Abstract
The invention relates to a road paver or a feeder with a machine frame, a travel carriage powered by a drive unit, and a material hopper with a material retention device arranged in the front in the operating direction, the material retention device comprising a fastening device and a retention element fastened to the material hopper through the fastening device, the material retention device having an overload protection device, which is designed in such a way that in the event of an overload applied thereto the retention element is detached the from material hopper and the fastening device, the latter remaining on the hopper, without damage. The invention also relates to a material retention device of such a road paver or feeder and a method for protecting a material retention device of such a road paver or feeder.
Claims
1. A road paver or feeder comprising: a machine frame; a travel carriage powered by a drive unit; and a material hopper with a material retention device arranged in the front in an operating direction, the material retention device comprising a fastening device and a retention element fastened to the material hopper by the fastening device, wherein the material retention device has an overload protection device, which is designed in such a way that in the event of an applied overload the retention element detaches from the material hopper and the fastening device, the latter remaining on the hopper, without damage.
2. The road paver or feeder according to claim 1, wherein the fastening device fastens the retention element to the material hopper by means of a force fit and/or an elastic form lock.
3. The road paver or feeder according to claim 1, wherein the fastening device comprises a threaded bolt mounted on the material hopper and a nut, a cap nut, preferably with an integrated washer.
4. The road paver or feeder according to claim 3, wherein the threaded bolt is shorter than the thickness of the retention element.
5. The road paver or feeder according to claim 1, wherein a screw-in stop is provided on the fastening device and/or on the material hopper, which restricts the extent to which the fastening device presses the retention element onto the material hopper in that the fastening device is stopped by the screw-in stop.
6. The road paver or feeder according to claim 1, wherein the retention element has a fastening opening, through which the fastening device penetrates the retention element, and a release recess, the release recess being designed as a slot running linearly from the fastening opening to the edge of the retention element.
7. The road paver or feeder according to claim 6, wherein the retention element is configured to be elastic and the release recess is narrower than the diameter of the fastening device such that an elastic form lock exists between the fastening device and the retention element.
8. The road paver or feeder according to any one of claim 6, wherein the longitudinal extension of the release recess runs from the fastening opening in a direction opposite the operating direction of the road paver or feeder, and horizontally.
9. The road paver or feeder according to claim 1, wherein multiple fastening devices are provided, which are arranged on the retention element vertically staggered to each other.
10. The road paver or feeder according to claim 9, wherein respectively one release recess is provided for each fastening device, and that the release recesses are configured to run parallel to each other.
11. The road paver or feeder according to claim 1, wherein the retention element has a tapered design on a face side mounted on the material hopper, and is tapered off on a vertically lower side.
12. A material retention device for a road paver or a feeder, the material retention device comprising at least one of the following features: the material retention device has an overload protection device; the material retention device comprises a retention element, the retention element having a fastening opening, through which a fastening device penetrates the retention element, and a release recess, the release recess being designed as a slot running linearly from the fastening opening to the edge of the retention element; the retention element is designed to be elastic and the release recess is narrower than the diameter of the fastening device such that an elastic form lock exists between the fastening device and the retention element; the longitudinal extension of the release recess runs parallel to a contact side of the retention element, and horizontally; multiple fastening devices are provided, which are arranged on the retention element vertically staggered to each other; and the retention element has a tapered design on a face side mounted on the material hopper, in such a way that it tapers off on a vertically lower side.
13. A method for the protection of a material retention device of a road paver or a feeder, comprising the following steps: a) fastening a retention element of the material retention device to a material hopper of the road paver or feeder by means of a fastening device; and b) detaching the retention element from the material hopper without damage and without detaching the fastening device.
14. The method according to claim 13, comprising in step b): sliding of the retention element past the fastening device by means of a release recess arranged in the retention element.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be explained in further detail below based on the exemplary embodiments shown in the figures. In the schematic figures:
[0025] FIG. 1 is a side view of a road paver;
[0026] FIG. 2 is a side view of a feeder;
[0027] FIG. 3 is a perspective view of a material hopper;
[0028] FIG. 4 is a perspective view of the connection of a retention element on the material hopper;
[0029] FIG. 5 is a side view of an end of a retention element fastened on the material hopper;
[0030] FIG. 6 is a sectional view of a first exemplary embodiment of a fastening device;
[0031] FIG. 7 is a sectional view of a second exemplary embodiment of a fastening device;
[0032] FIG. 8 is a sectional view of a third exemplary embodiment of a fastening device;
[0033] FIG. 9 shows a first exemplary embodiment of a release recess;
[0034] FIG. 10 shows a second exemplary embodiment of a release recess; and
[0035] FIG. 11 is a flowchart of the method.
DETAILED DESCRIPTION
[0036] Identical and identically functioning components are designated in the figures with the same reference signs. Recurring components are not separately designated in each figure.
[0037] FIGS. 1 and 2 show generic road construction machines, namely a road paver 1 (FIG. 1) and a feeder 9 (FIG. 2). The road construction machines 1, 9 have an operator platform 2 and a machine frame 3. Furthermore, they comprise a travel carriage 6, with which road construction machines 1, 9 move forward in operating direction a and which is powered by a drive unit 4, which most frequently comprises a diesel engine. The road paver 1 has a paving screed 7 on its rear, with which it can spread, smooth, and compact paving material transversely to the operating direction a. The feeder 9 on the other hand does not comprise a paving screed 7, but rather a feed conveyor 10, with which it can transfer paving material to a road paver 1. The road paver 1 as well as the feeder 9 have a material hopper 5 for paving material. The feeder 9 can transfer paving material from its material hopper 5 via the fee conveyor 10 into the material hopper 5 of the road paver 1. Moreover, the road paver 1, as well as the feeder 9, may be supplied with paving material by a transport vehicle not depicted, for example, a truck. For this type of loading, the road construction machines 1, 9 have buffer rollers 8 arranged in the front in the operating direction a. Using the buffer rollers 8, they push a transport vehicle in front of them during the loading process, while paving material is transferred from the transport vehicle to the material hopper 5. During the paving of a base layer by a road paver 1, normally multiple loads of paving material must be transferred from transport vehicles to the road paver 1 and/or the feeder 9.
[0038] FIG. 3 shows a perspective view diagonally from above and in the operating a in the front of the material hopper 5 of the road construction machines 1, 9. The material hopper 5 has a hopper floor 12 and side walls 14. The side walls 14 of the material hopper 5 be pivoted in normal operation to enable the hopper to be loaded and/or to influence the size the loading area. A screw conveyor 11 is located on the side of the material hopper 5 situated the rear in the operating direction a, which transfers the paving material from the material hopper 5 to a scraper belt 13, from which the paving material is conveyed in a direction opposite the operating direction a through the road construction machine 1, 9 and is either brought to a paving screed 7 or a feed conveyor 10.
[0039] On the side of the material hopper 5 situated in the front in the operating direction a, there is a material retention device 18. The material retention device 18 is located therefore on that side of the material hopper 5 on which a transport vehicle is pushed ahead during the loading process by the road construction machine 1, 9 via the buffer rollers 8. This side of the material hopper 5 is therefore also referred to as the filling side or the docking side. To enable the transfer process of the paving material from the transport vehicle to the material hopper 5, the material hopper 5 does not have a side wall projecting rigidly in the vertical direction on this side. Instead, the material retention device 18 is located here, which is composed of individual retention elements 15, 16, 17. The individual retention elements 15, 16, 17 are independently designed to enable the retention elements 15, 16, 17 to be displaced relative to each other. Thus, for example, the receiving volume of the material hopper 5 can be enlarged or reduced by pulling the hopper floor 12 apart or pushing it together in the direction of arrow b. Overall, the material retention device 18 has the effect that little or no paving material falls out of the material hopper 5 or is lost after or during loading from the transport vehicle to the material hopper 5 in the operating direction a. To ensure that the loading process is not impacted or hindered, the retention elements 15, 16, 17 of the material retention device 18 are designed elastically, for example, as rubber belts or rubber mats, particularly with fabric reinforcement. At least the retention elements 15 located on the outside transversely to the operating direction a, are mounted with their ends on the material hopper 5 or on side walls 4 of the material hopper 5. This connection of the retention elements 15 on the side walls 14 of the material hopper 5 is particularly exposed to high forces if the rear of the transport vehicle gets caught on the material retention device when loading the paving material, for example, when driving away after transferring the paving material. The retention element 15 is often torn out and damaged or destroyed at this point due to the enormous forces applied on the retention element 15. The retention elements 15 used in this case are about 2 meters long, about 3 centimeters high, and about 1 centimeter thick.
[0040] The overload protection 19 provisioned according to the invention is shown in further detail in FIGS. 4 and 5. FIG. 4 shows the end of the retention element 15, which is to the side wall 14 of the material hopper 5 according to Section A marked in FIG. 3. The retention element 15 is designed as a wide rubber belt, which is positioned essentially with its width B on the side of the material hopper 5 located in the front in the operating direction a. The thickness is designated with D and refers to the thickness of the retention element transversely to the width B or the distance of the two maximum outer surfaces of the retention element. The retention element prevents paving material from falling out of the material hopper 5 in this area. As revealed in FIGS. 4 and 5, the retention element 15 is fastened with its depicted end to the side wall 14 of the material hopper 5 via the fastening devices 21. As can also be seen in the figures, the retention element 15 is designed on this with a diagonal edge 31 in such a way that the edge 31 runs diagonally downwards vertically and the retention element 15 is therefore tapered or pointed. The tapered or pointed end of the retention element 15 is arranged on the side of the retention element 15 located vertically on bottom. Three fastening devices 21, through which the retention element 15 is fastened to the side wall 14 of the material hopper 5 are arranged vertically staggered with respect to each other in such a way that each fastening device 21 is spaced equally distant from the edge 31 the retention element 15 running diagonally. Thus, the fastening devices 21 are arranged in a step-like manner, which, especially together with the diagonal design of the end of the retention element 15, results in a particularly compact design and secure fastening of the material retention device 18 and particularly of the retention element 15. Release recesses 20 are also shown in FIGS. 4 and 5, through which the fastening devices 21 can be moved detachment of the retention element 15 from the fastening devices 21 and from the material hopper 5. During the detachment through the overload protection device 19, the retention element 15 moves forwards in the operating direction a in relation to the fastening devices 21 and the material hopper 5. As a result, the fastening devices 21 slide through the release recesses 20 and therefore release the retention element 15. The release recesses 20 extend in parallel to the operating direction a and parallel to each other. Thus, the overload protection device 19 is optimally geared for those forces that occur if the rear of a transport vehicle a tensile force on the retention element 15 when driving away from in front of road construction machine 1, 9, which would normally cause the retention element 15 to be destroyed.
[0041] FIG. 6 shows a first embodiment of the fastening device 21 in a sectional view the section line B of FIG. 5. The retention element 15 is attached on the side wall 14 of the material hopper 5 via the fastening device 21. The fastening device 21 passes completely through the retention element 15 from its first side 29 up to its second side 30 through the fastening opening 32 provided in the retention element 15. The fastening device 21 comprises threaded bolt 22 welded onto the side wall 14 of the material hopper 5 with an external thread and a nut 23, in this case a cap nut, with a washer 27, which is designed here integrally with nut 23. The nut 23 comprises an internal thread, with which it can be screwed onto the bolt 22. The thread of the nut 23 is closed toward the loading area of the material hopper 5 so that no paving material can get into the thread of the nut 23 or onto the thread of the threaded bolt 22. At the same time, the blank end of the thread of the nut 23 acts as a screw-in stop 24, which precisely defines how far the nut 23 can be screwed onto the threaded bolt 22. Based this specification, the force applied by the nut 23 on the retention element 15 is always the same, whereby the retention element 15 is always pressed with equal force against the side 14 of the material hopper 5. Therefore, the same force is always needed for pulling out or detaching the retention element 15 from the fastening device 21 in the operating direction a. During this type of detachment process, the fastening device 21 or threaded bolt 22 moves in relation to the retention element 15 through the release recess 20 and thus slides along the retention element 15 without damaging it.
[0042] FIG. 7 shows a view corresponding to FIG. 6 with an additional embodiment of a fastening device 21. The fastening device 21 in FIG. 7 also has a material hopper 5 or threaded bolt 22 welded onto the side wall 14, onto which a nut 23 is screwed. Unlike the embodiment according to FIG. 6, the length of the threaded bolt 22 is shorter than the thickness of the retention element 15. The thickness of the retention element 15 particularly denotes the distance between the first side 29 and the second side 30 of the retention element 15. The two sides 29, 30 are respectively those sides of the retention element 15 which have the largest area. Due to the fact that the length of the threaded bolt 22 is shorter than the thickness of the retention element 15, the retention element 15 must be slightly compressed in the area of the fastening opening 32 until the nut 23 can be screwed onto the external thread of the threaded bolt 22. However, this is readily possible due to the material of the retention element 15. Because the fastening device 21 has an overall shorter design, it protrudes less beyond the second side 30 of the retention element 15. As a whole, the fastening device 21 is therefore less at risk of being damaged during operating by paving material in the material hopper 5 or by the rear of a transport vehicle transferring paving material.
[0043] FIG. 8 shows an additional embodiment of the fastening device 21 pursuant to the view in accordance with FIG. 6. In contrast to the embodiments described above, the fastening device 21 of FIG. 8 has no threaded bolt 22 and no nut 23, but rather a screw 25, which is designed with an integrated washer 27 and which can be screwed into a threaded hole 26 in the side wall 14 of the material hopper 5. The threaded hole 26 of the material hopper 5 is designed as a blind hole and thus has a screw-in stop 24. The screw-in stop 24 restricts how far the screw 25 can be screwed into the threaded hole 26 and therefore the force with which the screw 25 holds the retention element 15 on the material hopper 5. In the event the retention element 15 is detached from the fastening device 21 by the overload protection device 19, the screw 25 will move with its shaft relative to the retention element 15 through the release recess 20 without the retention element 15 being damaged or destroyed in the process.
[0044] FIGS. 9 and 10 show different embodiments of the release recess 20 in a sectional view along the line C according to FIG. 8. In each case, the retention element 15 has a fastening opening 32. The fastening device 21, or more specifically the threaded bolt 22 or shaft of screw 25, extends through the fastening opening 32. The shaft of the screw 25 or the threaded bolt 22 has a diameter H.sub.1. In contrast, the embodiment of the release recess 20 depicted in FIG. 9 has a passage width or clear width H.sub.2 which is narrower than diameter The release recess 20 connects the fastening opening 32 with the edge 31 of the retention element 15. In other words, the fastening opening 32 is opened towards the edge 31 through release recess 20. Thus, there is a continuous recess from the edge 32 to the fastening device in the fastening opening 32. Due to the different dimensions of diameter H.sub.1 of the fastening device 21 and the passage width H.sub.2 of the release recess 20, an elastic stop 28 develops on transition between the fastening opening 32 and the release recess 20, which forms an elastic form lock between the retention element 15 and the fastening device 21. The elastic form is based on the elasticity of the material of the retention element 15, and its strength can be adjusted through the elasticity of this material. Now, if the retention element 15 is to be detached from the fastening device 21 and thus from the material hopper 5, in addition to the force fit, which is effected by the fastening device 21 pressing the retention element 15 onto material hopper 5, the elastic form lock must likewise be overcome on the elastic stop 28. In other words, to ensure that the threaded bolt 22 or the shaft of the screw 25 can slide through the release recess 20, it must first be widened to the diameter H.sub.1 of the fastening device 21. Together with the force fit through the fastening device 21, the force necessary for this adds to the total retention force that fastens the retention element 15 on the material hopper 5 and the fastening device 21. In contrast, the retention element 20 has a passage width H.sub.3 which is larger than diameter H.sub.1 of the threaded bolt 22 or the shaft of the screw 25 in the alternative embodiment according to FIG. 10. Thus, once the force fit has been overcome by the fastening device 21, it can pass through the release recess 20 unhindered. Due to the retention element 21 sliding along unhindered through the release recess 20 in this embodiment, to the retention element 15 is prevented particularly efficiently.
[0045] FIG. 11 shows a flowchart of the method 36 according to the invention. The method begins in step 33 with the fastening of the retention element 15 on the material hopper 5 by means of the fastening device 21. Subsequently, if an overload occurs during normal of the road construction machine 1, 9, i.e., if forces are applied to the retention element 15 which exceed the specified threshold value, the retention element 15 will be detached from material hopper 5 in step 34 without damage or destruction, while the fastening device 21 is detached and continues to remain on the material hopper 5. In this connection, the threshold value is selected such that, on the one hand, the retention element 15 will not be detached if only those forces act upon it that can be absorbed by the elasticity of the material of the retention element 15 without damaging or destroying it. On the other hand, the threshold is selected such that the retention element 15 is ensured to be detached before a risk of or destruction of the retention element 15 occurs. The exact selection of the threshold value may vary depending on the used material for the retention element 15, and may be by means of simple trial and error. The threshold value on the overload protection device 19 set through the configuration of the fastening device 21 and/or a potential elastic form lock. in all, an overload protection device 19 is achieved which enables damage and/or destruction the retention element 15 to be reliably prevented. As illustrated by the reverse arrow in FIG. 11, the retention element 15 can be easily remounted in its position on the material hopper 5 after being successfully detached from the material hopper 5 or the fastening device 21 by detaching the fastening device 21 and then reattaching it with the retention element 15 on the material hopper 5. Thus, the retention element 15 can be protected against destruction and reused due to the method according to the invention, and does therefore not need to be by a new retention element 15. If the overload protection device 19 or the retention element is used with a release recess 20, step 34 (detachment of the retention element 15) may optionally be supplemented by step 35, which involves the retention element 15 passing past the fastening device 21 through the release recess 20 arranged in the retention element 15. Overall, the intensity of maintenance and the consumption of wear materials on the road construction machine 1, 9 according to the invention can be reduced in this manner, whereby the invention contributes to lowering operating costs.
