Device, as well as method for working ground surfaces or roadways

Abstract

A device for working ground surfaces or roadways including a machine frame and a working drum in a drum housing arranged on said machine frame, where no less than one spraying device extending parallel to the working drum and featuring several outlet nozzles for spraying agents arranged next to one another and directed towards the working drum is arranged on the drum housing. Wherein each outlet nozzle includes a drivable closing mechanism with a closing element which, in an open position, fully uncovers the nozzle channel of the outlet nozzle. In a closed position, closes the nozzle channel. Such that the following functions are achieved: that a controller drives the closing mechanisms, with the outlet nozzles and the related closing elements being adapted to one another in such a fashion that the flow cross-section in the outlet nozzle is variable in accordance with the position of the closing element on a specified path between the open position and closed position.

Claims

1. An apparatus for working ground surfaces or roadways, comprising: a machine frame; a drum housing supported from the machine frame; a working drum located in the drum housing; at least one spraying system including at least first and second outlet nozzle assemblies arranged next to one another and directed toward the working drum for spraying agents, each of the first and second outlet nozzle assemblies including: an outlet nozzle including a nozzle channel having a channel outlet; a drivable closing mechanism including a closing element movable on a specified path between an open position, and a closed position, each closing element including a first section facing the channel outlet and a second section on an opposite side of the first section from the channel outlet, the first section having a smaller cross-sectional area than the second section, the second section being sized to close the nozzle channel; and the outlet nozzle and the closing element being configured such that a discontinuous variation in flow cross-section between the nozzle channel and the closing element is provided in accordance with a position of the closing element on the specified path; and a controller operably associated with the drivable closing mechanisms and configured to position at least one of the closing elements in at least one intermediate position between the open and closed positions of the at least one closing element.

2. The apparatus of claim 1, wherein: the discontinuous variation is provided at least in part by a discontinuous cross section of the nozzle channel.

3. The apparatus of claim 1, wherein: the discontinuous variation is provided at least in part by a discontinuous cross section of the closing element.

4. The apparatus of claim 3, wherein: the discontinuous cross section of the closing element includes a tapered portion of the closing element.

5. The apparatus of claim 3, wherein: the discontinuous cross section of the closing element includes a stepped portion of the closing element.

6. The apparatus of claim 1, wherein: the discontinuous variation in flow cross-section between the nozzle channel and the closing element is provided at least in part by a taper in at least one of the nozzle channel and the closing element.

7. The apparatus of claim 1, wherein: the discontinuous variation in flow cross-section between the nozzle channel and the closing element is provided at least in part by a step in at least one of the nozzle channel and the closing element.

8. The apparatus of claim 1, wherein: the discontinuous variation in flow cross-section between the nozzle channel and the closing element is provided at least in part by a cut-out in at least one of the nozzle channel and the closing element.

9. The apparatus of claim 1, wherein: the discontinuous variation in flow cross-section between the nozzle channel and the closing element is provided at least in part by a discontinuity in at least one of the nozzle channel and the closing element.

10. The apparatus of claim 1, wherein: the closing elements of the first and second outlet nozzle assemblies are positionable by the controller in individually different intermediate positions between their open and closed positions.

11. The apparatus of claim 1, wherein: the flow cross-section between each nozzle channel and its respective closing element decreases discontinuously as the closing element moves toward the closed position.

12. The apparatus of claim 1, wherein: each closing element is movable and positionable coaxially with the nozzle channel of its respective outlet nozzle.

13. The apparatus of claim 1, wherein: each outlet nozzle includes a variable nozzle geometry such that the flow cross-section between the nozzle channel and its respective closing element decreases as the closing element moves toward the closed position.

14. The apparatus of claim 1, wherein: the controller is configured to cause an additional movement of each closing element beyond the closed position to enable material accumulations in and/or in front of the outlet nozzle to be removed.

15. The apparatus of claim 1, wherein: the nozzle channel of each outlet nozzle includes on an inlet side a first section having a conical cross-section narrowing in a direction of flow of the outlet nozzle.

16. An apparatus for working ground surfaces or roadways, comprising: a machine frame; a drum housing supported from the machine frame; a working drum located in the drum housing; at least one spraying system including at least first and second outlet nozzle assemblies arranged next to one another and directed toward the working drum for spraying agents, each of the first and second outlet nozzle assemblies including: a nozzle channel having a channel outlet; a drivable closing mechanism including a closing element movable on a specified path between an open position and a closed position, each closing element including a first cylindrical portion closest to the channel outlet and a second cylindrical portion on an opposite side of the first cylindrical portion from the channel outlet, the first cylindrical portion having a smaller cross-sectional area than the second cylindrical portion; and the nozzle channel and the closing element being configured such that a flow cross-section between the nozzle channel and the closing element is variable in accordance with a position of the closing element on the specified path; and a controller operably associated with the drivable closing mechanisms and configured to drive the closing mechanisms.

17. The apparatus of claim 16, wherein: the nozzle channel has a variable cross-sectional area including a smallest channel cross-section portion; and in a partially open position the first cylindrical portion of the closing element is concentrically received in the smallest channel cross-section portion such that there is an annular flow area between the first cylindrical portion of the closing element and the smallest channel cross-section portion.

18. The apparatus of claim 17, wherein: the first cylindrical portion of the closing element has an axial length greater than an axial length of the smallest channel cross-section portion.

19. The apparatus of claim 16, wherein: the nozzle channel has a variable cross-sectional area including a smallest channel cross-section portion; and the first cylindrical portion of the closing element has an axial length greater than an axial length of the smallest channel cross-section portion.

20. The apparatus of claim 16, wherein: the nozzle channel has a variable cross-sectional area including a smallest channel cross-section portion; and the nozzle channel has a lowermost radially outwardly tapered portion below the smallest channel cross-section portion.

21. The apparatus of claim 16, wherein: the closing element is extendable axially outward from the nozzle channel beyond the closed position.

22. An apparatus for working ground surfaces or roadways, comprising: a machine frame; a drum housing supported from the machine frame; a working drum located in the drum housing; at least one spraying system including at least first and second outlet nozzle assemblies arranged next to one another and directed toward the working drum for spraying agents, each of the first and second outlet nozzle assemblies including: a nozzle channel, the nozzle channel having a variable cross-sectional area including a smallest channel cross-section portion; a drivable closing mechanism including a closing element movable on a specified path between an open position and a closed position, each closing element including a larger diameter closing element portion and a cylindrical smaller diameter closing element portion, the cylindrical smaller diameter closing element portion being received in the smallest channel cross-section portion in a partially open position of the closing element; and the nozzle channel and the closing element being configured such that a flow cross-section between the nozzle channel and the closing element is variable in accordance with a position of the closing element on the specified path; and a controller operably associated with the drivable closing mechanisms and configured to drive the closing mechanisms.

23. The apparatus of claim 22, wherein: in the closed position the larger diameter closing element portion closes the nozzle channel.

24. The apparatus of claim 22, wherein: in the partially open position the cylindrical smaller diameter closing element portion is concentrically received in the smallest channel cross-section portion such that there is an annular flow area between the cylindrical smaller diameter closing element portion and the smallest channel cross-section portion.

25. The apparatus of claim 22, wherein: the cylindrical smaller diameter closing element portion has an axial length greater than an axial length of the smallest channel cross-section portion.

26. The apparatus of claim 22, wherein: the nozzle channel has a lowermost radially outwardly tapered portion below the smallest channel cross-section portion.

27. The apparatus of claim 22, wherein: the closing element is extendable axially outward from the nozzle channel beyond the closed position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following, embodiments of the invention are explained in more detail with reference to the drawings:

(2) The following is shown:

(3) FIG. 1 shows a road construction machine.

(4) FIG. 2 shows the working chamber of a working drum underneath a drum housing with injection device.

(5) FIG. 3a shows an open position of the closing element.

(6) FIG. 3b shows a closed position of the closing element.

(7) FIG. 3c shows a further extended position of the closing element.

(8) FIG. 4a shows one embodiment of an outlet nozzle with an initially conical nozzle channel.

(9) FIG. 4b shows another embodiment of an outlet nozzle with an initially conical nozzle channel.

(10) FIG. 5a shows one embodiment of an outlet nozzle with a nozzle channel featuring a constant cross-section.

(11) FIG. 5b shows a second embodiment of an outlet nozzle with a nozzle channel featuring a constant cross-section.

(12) FIG. 5c shows a third embodiment of an outlet nozzle with a nozzle channel featuring a constant cross-section.

(13) FIG. 6 shows a closing element with altered tip geometry.

(14) FIG. 7 shows an embodiment of an outlet nozzle for foamed bitumen.

DETAILED DESCRIPTION

(15) FIG. 1 shows an automotive device for working roadways, in particular a cold recycler or a soil stabilizer, with a machine frame 1 carried by wheels 2 and an operator's platform comprised of a driver's cabin 3. The wheels 2 may be driven individually and may alternatively also be replaced by crawler tracks.

(16) A working drum 4 is arranged underneath the machine frame 1 in a drum housing 8 which forms the boundary of the working chamber 6 of the working drum 4 towards the top and to the sides. A detailed description of the road construction machine shown in FIG. 1 can be inferred from WO-A96/24725 (U.S. Pat. No. 5,893,677), the details of which are incorporated herein by reference.

(17) The drum housing 8 features a spraying device 10 in its upper section which can be used to inject, by means of several outlet nozzles 12 arranged preferably next to one another, for example, binding agents or water into the working chamber 6 and onto the working drum 4.

(18) The binding agent can include hydraulic or bituminous binding agents and, in case of mixtures of hydraulic binding agents and water, of slurries, such as water-cement slurry, or, in case of mixtures of bituminous binding agents and water, of emulsions. Furthermore, foamed bitumen can be injected via the outlet nozzles 12 where, for the production of foamed bitumen, heated, liquid bitumen is mixed with cold water. This causes the bitumen to foam, the original volume of the components increasing by about 20 times.

(19) The spraying device 10 obtains the binding agent or water via a conduit 14 which may be a loop conduit. The binding agent or water runs transverse to the outlet nozzle 12. The outlet nozzle 12 attached to the conduit 14 is directed into the working chamber 6 and is arranged in a cut-out of the drum housing 8 adapted to the outlet nozzle 12. The tools 16 of the working drum have a cutting circle which may exhibit a relatively small distance to the drum housing 8 of, for example, approx. 50 mm. For each outlet nozzle 12, a closing mechanism 18 is intended which is comprised of a piston-cylinder unit 20, the piston rod of which forms or drives a closing element 22 for the outlet nozzle 12. The closing mechanism 18 drivable, for example, by a controller is variably adjustable. In an open position of the closing element 22 (FIG. 3a), the outlet nozzle is fully uncovered. In the closed position (FIG. 3b), the outlet nozzle 12 is closed so that no binding agent or water can exit at said outlet nozzle 12. In addition, no material 24 worked off and mixed with binding agents or water can penetrate the nozzle channel 26 of the outlet nozzle 12 from the working chamber 6. Between the open position and the closed position, the controller can adjust any intermediate positions in order to variably adapt the flow cross-section through the outlet nozzle to the current working conditions. In a special function, the closing element 22 can further be transferred into a cleaning position beyond the closed position.

(20) The tip of the closing element 22 facing the working chamber 6 terminates at the end of the nozzle channel 26 facing the working chamber 6 and is preferably recessed vis--vis the shell surface 9 of the drum housing 8 facing the working chamber 6 in order to avoid damage to the closing element 22 during the working operation.

(21) FIGS. 4a and 4b show an embodiment of an outlet nozzle 12 at its nozzle inlet opening 28 comprising a first section 27 which narrows conically in the direction of flow, as well as a second section 29 following in the direction of flow which comprises a nozzle channel 26 with a constant cross-section.

(22) Depending on the position of the cylindrical closing element 22, a different flow cross-section results as a function of the variable position of the closing element 22 when the closing element 22 is in the area of the outlet nozzle 12.

(23) It is understood that, in variation of the embodiment in FIGS. 4a and 4b, a different narrowing cross-sectional shape of the first section 27 is also possible in which the nozzle cross-section of the nozzle channel does not narrow continuously.

(24) FIGS. 5a to 5c show another embodiment of the outlet nozzle 22 in which the nozzle channel 26 preferably features a non-alterable cross-section and is additionally preferably cylindrical in shape.

(25) In general, the embodiments shown in FIGS. 5a to 5c relate to an embodiment in which the first section 27 of the outlet nozzle 12 comprises no less than one cut-out 31 which may be of different designs.

(26) In the embodiment shown in FIG. 5a, the first section 27 comprises a wall with a basically cylindrically hollow cross-section, where the cut-out 31, in the embodiment of FIG. 5a, forms approx. one half of a hollow cylinder. It is understood that the cut-out 31 may also have a smaller or larger circumference or that several cut-outs 31 may also be arranged in the basically cylindrically hollow first section 27.

(27) The embodiment of FIG. 5b shows a first section 27 of the outlet nozzle 12 in which the cut-out 31 tapers in the direction of flow of the outlet nozzle 12. In this embodiment, it is also possible for several such V-shaped cut-outs 31 to be distributed on the circumference of the first section.

(28) In the embodiment of FIG. 5c, the first section 27 of the outlet nozzle 12 has an initially basically cylindrically hollow shape, in which arrangement one or several cylindrical cut-outs 31 may be arranged in the hollow cylinder forming the section 27.

(29) Finally, cut-outs of different designs may also be intended for all embodiments of FIGS. 4a to 5c.

(30) It is understood that the first section 27 of the outlet nozzle 12 is mounted in such a fashion that the cut-outs are pressurized, from the outside, with the fluid pressure of the spraying agent.

(31) In principle, there is also the possibility to combine the design of the first section 27 according to FIG. 4a or 4b with the design of the embodiments shown in FIGS. 5a to 5c.

(32) In all embodiments, the nozzle cross-section can therefore be varied in accordance with the position of the closing element 22.

(33) FIG. 6 shows an embodiment of an outlet nozzle 12 in which the closing element 22 comprises a first section 21 facing the outlet nozzle 12, said first section 21 exhibiting a smaller cross-sectional area than the cross-sectional area of the nozzle channel 26 while the second section 23, which follows behind the first section 21 as seen in the direction of flow of the outlet nozzle 12, is precisely adapted to the cross-section of the nozzle channel 26 in order to be able to close the nozzle channel 26.

(34) The section 21 may also feature a continuously changing cross-sectional area, for example, a conically tapering tip of the closing element 22.

(35) In this design, the closing element 22 may also be driven, in an intermediate position between the open position and the closed position, by the controller 11 in such a fashion that a changed nozzle cross-section is adjustable.

(36) The embodiment of FIG. 6 with a closing element 22 tapering towards the tip is also combinable with the embodiments of FIGS. 4a-4b and 5a-5c.

(37) All embodiments shown in FIGS. 4a to 6 have in common that the controller 11 can drive the closing elements 22 in such a fashion that the flow cross-section in the outlet nozzle 12 is variable in accordance with the position of the closing element 22.

(38) In this arrangement, several outlet nozzles can be driven by the controller in the same way or individually.

(39) In a further switching position shown in FIG. 3c in which the closing element 22 is moved, via an additional stroke movement of the closing element 22, beyond the closed position, the closing element 22 can remove material accumulations of the worked-off material 24 in and/or in front of the outlet nozzle 12.

(40) FIG. 7 shows an embodiment of a spraying device 10 for foamed bitumen with a mixing device 36. The mixing device 36 comprises an expansion chamber 38 in which hot bitumen supplied via a bitumen injection nozzle 40 is mixable with water or with water and air for the production of foamed bitumen. The expansion chamber 38 shown in FIG. 7 is comprised of a mixing chamber 42 and an injection chamber 44 connected to the mixing chamber 42, with the outlet nozzle 12 and the related closing mechanism 18 being arranged at the injection chamber 44. The hot bitumen is supplied via a loop conduit 15, with a valve tappet 46 actuated by a drivable driving device being able to close or uncover the nozzle inlet opening of the bitumen injection nozzle 40. Water or water and air can be supplied via one or two connections 41 of the mixing chamber 42.

(41) The mixing device 36 may be surrounded by a heating device 48 which prevents hardening of the bitumen during the working operation. The closing element 22 of the closing mechanism 18 traverses the injection chamber 44 for the purpose of closing or cleaning the outlet nozzle 12.

(42) It is understood that it is also possible to use other driving devices drivable by the controller, such as electric motors, linear drives or similar.