Ground milling machine with dust removal device and service tunnel and method

Abstract

A ground milling machine, comprising a milling drum, rotatably mounted in a milling-drum housing, for removing ground material, a milled-material conveying apparatus for transporting the removed ground material and a dust extraction apparatus for extracting dust-containing air from a region of the milled-material conveying apparatus, the dust extraction apparatus comprising at least one extraction line, which opens into the region of the milled-material conveying apparatus via an extraction opening, the ground milling machine comprising a left side wall, a right side wall, a front wall and a rear wall, and wherein a maintenance tunnel is provided which is designed such that it establishes an access connection, accessible from outside the ground milling machine, between the extraction opening and one of the side walls, the front wall or the rear wall of the ground milling machine. A method for maintenance of the dust extraction apparatus is also disclosed.

Claims

1. A ground milling machine for machining ground in, or counter to, a working direction, comprising: a machine frame, supported by travel apparatuses, comprising a drive engine; a milling drum, rotatably mounted in a milling-drum housing arranged on the machine frame, for removing ground material; a milled-material conveying apparatus for transporting the removed ground material from the milling-drum housing to a discharge point; and a dust extraction apparatus for extracting dust-containing air from a region of the milled-material conveying apparatus, wherein the dust extraction apparatus comprises at least one extraction line, which opens into the region of the milled-material conveying apparatus via an extraction opening, wherein the ground milling machine comprises a left side wall, a right side wall, a front wall and a rear wall, wherein a maintenance tunnel is provided which comprises a tunnel entrance opening and a tunnel exit opening and is configured such that, via the tunnel entrance opening, the maintenance tunnel establishes an access connection, accessible from outside the ground milling machine, between one of the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine and the extraction opening; and wherein the left side wall, the right side wall, the front wall and the rear wall are each outer walls of the ground milling machine.

2. The ground milling machine according to claim 1, wherein the dust extraction apparatus comprises an extraction hood which is open towards the region of the milled-material conveying apparatus, comprises the extraction opening arranged in the region of the milled-material conveying apparatus and into which both the extraction line and the maintenance tunnel open.

3. The ground milling machine according to claim 1, wherein two maintenance tunnels are provided, wherein the second maintenance tunnel establishes an access connection between the extraction opening and an additional one of the left side wall, the right side wall, the front wall or the rear wall.

4. The ground milling machine according to claim 3, wherein one of the two maintenance tunnels is arranged with its tunnel entrance opening on the left side wall and the other of the two maintenance tunnels is arranged with its tunnel entrance opening on the right side wall, and wherein the two maintenance tunnels open into the extraction opening.

5. The ground milling machine according to claim 4, wherein the two maintenance tunnels open into the extraction opening, in an extraction hood.

6. The ground milling machine according to claim 5, wherein the two maintenance tunnels open into the extraction opening, in the extraction hood, opposite one another.

7. The ground milling machine according to claim 1, wherein the maintenance tunnel has at least one of the following features: the maintenance tunnel extends in a straight line and/or without bends and/or without coils; the maintenance tunnel is configured such that the tunnel entrance opening is arranged to be vertically higher than the tunnel exit opening; the maintenance tunnel extends horizontally; the maintenance tunnel is configured such that its clear width from the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine remains constant or decreases or increases up to the extraction opening or an extraction hood; the maintenance tunnel extends through a water tank of the ground milling machine at least in part; the maintenance tunnel extends substantially perpendicularly to a steering axis of the ground milling machine or in parallel with a rotational axis of the milling drum; the maintenance tunnel is arranged on the ground milling machine such that, when the ground milling machine is in a maintenance position, the maintenance tunnel is located at most 2 m vertically above the ground.

8. The ground milling machine according to claim 7, wherein the maintenance tunnel is arranged on the ground milling machine such that, when the ground milling machine is in the maintenance position, the maintenance tunnel is located at most 1.5 m vertically above the ground.

9. The ground milling machine according to claim 1, wherein on a side of the maintenance tunnel arranged to face away from the extraction opening, a maintenance cover is movable between an open position and a closed position is provided, which cover is configured such that the cover can close the maintenance tunnel on the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine.

10. The ground milling machine according to claim 9, wherein the maintenance cover is connected to a plug such that the plug closes the tunnel exit opening between the extraction opening or an extraction hood and the maintenance tunnel when the maintenance cover closes the maintenance tunnel on the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine.

11. The ground milling machine according to claim 9, wherein a closure sensor is provided which is configured to determine whether the maintenance cover is in the closed position.

12. A method for the maintenance of the dust extraction apparatus for extracting dust-containing air from the milled-material conveying apparatus of the ground milling machine, according to claim 1, comprising the steps of: a) opening the maintenance tunnel which establishes the access connection between the extraction opening and/or an extraction hood of the dust extraction apparatus and the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine; b) performing maintenance on the at least one extraction line and/or the extraction hood and/or the extraction opening through the maintenance tunnel; and c) closing the maintenance tunnel on the left side wall, the right side wall, the front wall or the rear wall of the ground milling machine.

13. The method according to claim 12, wherein the method is carried out by an operator standing beside the ground milling machine.

14. The ground milling machine according to claim 1, wherein the ground milling machine is a road milling machine, a recycler or a stabilizer.

15. The ground milling machine according to claim 1, wherein the maintenance tunnel extends between the tunnel entrance opening and the tunnel exit opening.

16. The ground milling machine according to claim 1, wherein the maintenance tunnel comprises at least one wall portion extending around a longitudinal tunnel axis.

17. The ground milling machine according to claim 1, wherein the maintenance tunnel is formed as an elongate cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in greater detail in the following with reference to the embodiments shown in the drawings, in which, schematically:

(2) FIG. 1 is a side view of a ground milling machine in a work train with a transport vehicle;

(3) FIG. 2 is an enlarged side view of the ground milling machine according to FIG. 1;

(4) FIG. 3 is a perspective oblique view of part of the machine frame and the dust extraction apparatus of a ground milling machine from behind and from above;

(5) FIG. 4 shows a maintenance cover comprising a plug;

(6) FIG. 5 is another perspective view according to FIG. 3 from behind;

(7) FIG. 6 is another perspective view according to FIG. 3 from below; and

(8) FIG. 7 is a flow diagram of the method.

DETAILED DESCRIPTION

(9) Identical or identically functioning components are denoted by identical reference signs in the drawings. Repeated components are not denoted separately in each figure.

(10) FIG. 1 shows a work train comprising a ground milling machine 1, in this case a road milling machine, and a transport vehicle 11, specifically a truck. The ground milling machine 1 is shown again in FIG. 2 in an enlarged manner. It comprises a machine frame 3 comprising a driver's platform 2. The machine frame 3 is supported by travel apparatuses 6, which are crawler tracks in the embodiment shown, but could also be wheels. The travel apparatuses 6 are mounted on the machine frame 3 by height-adjustable lifting columns 14. For powering, the ground milling machine 1 comprises an engine 4, which is typically a diesel internal combustion engine. The ground milling machine 1 comprises a milling drum 9, which is rotatably mounted in a milling-drum housing 7. The milling drum 9 is equipped with milling tools and mills off ground material from the ground 8 by rotating during the work operation of the ground milling machine 1. In this process, the ground milling machine 1 moves in or counter to the working direction a. In the embodiment shown, the milled-off ground material is loaded from the milling-drum housing 7 forwards in the working direction a onto the transport vehicle 11 by means of a milled-material conveying apparatus 28. The milled-material conveying apparatus 28 comprises two separate conveying apparatuses. A loading conveying apparatus 10, which receives the milled material from the milling-drum housing 7 and conveys it forwards through the machine frame 3 at least in part in the working direction a, is located in the interior of the machine. At the end of the machine frame 3 at the front in the working direction a, the loading conveying apparatus 10 then loads the milled material onto a discharge conveying apparatus 5 attached to the machine frame 3. The discharge conveying apparatus 5 then transports the milled material further towards the transport vehicle 11 and vertically upwards as far as a discharge point 27, from which the milled material is discharged onto the transport bed of the transport vehicle 11. The loading conveying apparatus 10 and the discharge conveying apparatus 5 are designed as conveyor belts, for example. It is also possible for the milled-material conveying apparatus 28 to only comprise one single transport conveyor belt. The present embodiment also shows a ground milling machine 1 comprising a milling-drum housing 7 positioned between the front and the rear travel apparatuses 6, when viewed in the working direction, at a distance therefrom in the working direction a in each case. Ground milling machines 1 of this kind are also called central rotor milling machines. However, the invention also equally relates to ground milling machines in which the milling-drum housing 7 is positioned at the rear, specifically between the two rear travel apparatuses 6, i.e. what are known as rear rotor milling machines. It is also not necessary, although it is preferred, for all the travel apparatuses 6 to each be connected to the machine frame 3 by a height-adjustable lifting apparatus, for example lifting columns 14.

(11) In order to prevent dust-polluted air from being output into the external environment around the ground milling machine 1 as far as possible or to at least considerably reduce this, the ground milling machine 1 comprises a dust extraction apparatus 16. This may for example be designed in the same way as in the prior art mentioned at the outset. It may comprise a fan or another extraction apparatus, by means of which the dust-polluted air is extracted from a region of the milled-material conveying apparatus 28 via at least one extraction line 12. This region is characterized in that it constitutes a space through which the milled-material conveying apparatus 28 passes in part and in which dust-polluted air develops during the milling operation of the ground milling machine 1. Usually, this region is therefore a region adjoining the milling-drum housing in the conveying direction of the milled material. The region relevant for the dust extraction here is also in the interior of the ground milling machine 1 itself or in a part of the machine through which the loading conveying apparatus 10 passes, and not in the region of the outer conveyor belt or the discharge conveying apparatus 5. In the embodiment shown, the dust extraction apparatus 16 extracts dust-polluted air in the region of the loading conveying apparatus 10, for example, specifically in the conveying shaft 22 of the loading conveying apparatus 10. The dust is then removed from this air or this air is merely fed back to the milled material in the region of the discharge conveying apparatus 5, for example. This alone makes it possible to reduce the dust pollution in the environment in the region of the ground milling machine 1. As shown in FIG. 2, the dust extraction apparatus 16 may extend through a water tank 13 of the ground milling machine 1 at least in part. In this way, the capacity of the water tank 13 is reduced as little as possible by the dust extraction apparatus 16.

(12) In particular, the region of the dust extraction apparatus 16 which opens into the region or conveying shaft 22 of the milled-material conveying apparatus 28, specifically the loading conveying apparatus 10, can become very dirty during operation, meaning that blockages may occur. This region is also called the extraction region AB. The extraction region AB is therefore in particular the region in which the extraction effect of the dust extraction occurs during operation. The extraction region AB may become blocked in particular in the region of the inlet openings of the extraction lines 12 (variants comprising just one extraction opening and/or one extraction line are also included here). By means of the maintenance tunnel 15, which is described in greater detail in the following, the invention provides the possibility of cleaning this extraction region AB more easily, as described in greater detail in the following, in particular with reference to FIGS. 3, 5 and 6. For this purpose, as shown in FIG. 2, the maintenance tunnel 15 is arranged on the ground milling machine 1 such that, in the maintenance position of the ground milling machine 1, it is at a height H that is easily accessible to an operator standing beside the ground milling machine 1. The height H denotes the vertical distance between the tunnel entrance opening 33 (see FIG. 3, for example) of the maintenance tunnel 15 and the ground 8.

(13) FIG. 3 is an oblique perspective view from behind and from the left of the part of the ground milling machine 1 according to detail A from FIG. 2. Other parts of the ground milling machine 1 and parts of the machine frame 3 have been omitted for the sake of clarity. In particular, FIG. 3 shows the inner space in the water tank 13 through which two extraction lines 12 extend in the present embodiment. Both extraction lines 12 proceed forwards from an extraction hood 19 in the working direction a and open into continuing hose connections to the extraction apparatus in the front side of the machine frame. As shown in particular in the view from below according to FIG. 6, the extraction hood 19 is open vertically at the bottom, with a passage through the water-tank base 18 also being arranged here. Overall, the extraction opening 30 is therefore formed, which establishes a connection between the conveying shaft 22 of the loading conveying apparatus 10, which is below the water tank 13, and the extraction hood 19. Overall, the dust extraction apparatus 16 therefore extracts dust-polluted air from the conveying shaft 22 into the extraction hood 19 through the extraction opening 30 and, from there, extracts it into the extraction lines 12, from which the dust-polluted air is transported away. The extraction region therefore substantially comprises the extraction opening 30 and the extraction hood 19 as well as the inlets to the extraction lines 12. This region may become coated or blocked with dirt during the work operation of the ground milling machine 1. Until now, in the prior art, it was necessary to drain the water from the water tank 13 in order to perform maintenance on the extraction region and to then gain access to the extraction hood 19 from above through the service hatch 21 (see FIG. 3) or to crawl underneath the machine. The extraction hood 19 then had to be opened in order for it to be possible to carry out cleaning, for example. On one hand, a drawback of this is the high level of additional work involved in draining the water tank 13 and opening the extraction hood 19 as well as the service hatch 21. On the other hand, the service hatch 21 is only accessible from the top of the ground milling machine 1, which means that, to use it, an operator has to climb onto the machine, which is not only inconvenient, but can also be dangerous.

(14) By contrast, the invention proposes providing at least one maintenance tunnel 20, through which the extraction region and in particular the extraction opening 30 is accessible to an operator standing on the unmilled surface of the ground beside the ground milling machine 1. In the specific embodiment, two maintenance tunnels 20 are provided, which open into the extraction hood 19 from opposite sides of the ground milling machine 1. In the present case, a distinction is made between four different sides of the ground milling machine 1 in total. All of these sides form the boundaries of the outer contour of the machine frame 3 and are accessible to an operator standing beside the ground milling machine 1 from the outside. Therefore, the ground milling machine 1 comprises a left side wall 23 and a right side wall 24, for example. The side walls 23, 24 form the left and right lateral boundary of the ground milling machine 1 and extend substantially vertically and in parallel with the working direction a, and they may likewise contain curves or steps. Furthermore, the ground milling machine 1 comprises a front wall 29. The front wall 29 is the wall at the front end of the machine frame 3 in the working direction. A conveying apparatus arranged further forwards in the working direction a, i.e. the discharge conveying apparatus 5 in the embodiment shown, is not seen here. The support 17 for the discharge conveying apparatus 5 is therefore likewise arranged on the front wall 29 of the ground milling machine 1. In addition, the ground milling machine 1 of course likewise comprises a rear wall 32 (see FIGS. 1 and 2), which forms the boundary of the machine frame 3 at the rear in the working direction a. The front wall 29 and the rear wall 32 are oriented substantially vertically and transversely to the working direction a. In principle, the maintenance tunnel 20 according to the invention could then be arranged on each of said sides, i.e. the left side wall 23, the right side wall 24, the front wall 29 or the rear wall 32. In the embodiment shown in the drawings, a total of two maintenance tunnels 20 are provided, with one maintenance tunnel 20 being arranged on the left side wall 23 and one maintenance tunnel 20 being arranged on the right side wall 24.

(15) A maintenance tunnel 20 according to the invention comprises a tunnel entrance opening 33 and a tunnel exit opening 34. The tunnel exit opening 34 establishes the connection between the inner space in the maintenance tunnel 20 and the extraction hood 19. In the embodiment shown, the tunnel exit openings 34 of the two maintenance tunnels 20 are on opposite sides of the extraction hood 19, meaning that they are particularly easily accessible. The tunnel entrance opening 33 in turn connects the inner space in the maintenance tunnel 20 to the external environment around the ground milling machine 1. Therefore, the tunnel entrance openings 33 of the two maintenance tunnels 20 in the embodiment shown are arranged on the left side wall 23 and the right side wall 24, respectively. The maintenance tunnel 20 extends between the tunnel entrance opening 33 and the tunnel exit opening 34 in a straight line with a constant clear width. In the same way as the extraction lines 12, the maintenance tunnels 20 extend through the inner space in the water tank 13, in order to limit the volume thereof less significantly than would be the case if an indentation were formed in the water tank 13. An operator standing beside the ground milling machine 1 can easily use the access to the extraction hood 19 through the maintenance tunnels 20 for maintenance or cleaning work. For example, a maintenance tool, for example a pressure washer, can be inserted through the maintenance tunnels 20 as far as the extraction region, for example the extraction hood 19. Stubborn blockages in the extraction region can also be removed in this way.

(16) To avoid that the dust extraction apparatus 16 draws in air through the maintenance tunnels 20, which would mean that the extraction power was reduced in the region of the milled-material conveying apparatus 28, a maintenance cover 15 is provided, which can cover the maintenance tunnels 20 at least at their tunnel entrance openings 33. The maintenance cover 15 is fastened to the machine frame 3 in a hinged manner, for example, such that it can be moved between an open position, in which it opens the tunnel entrance opening 33, and a closed position, in which it closes the tunnel entrance opening 33. In particular, the maintenance cover 15 is formed such that it closes the tunnel entrance opening 33 in an airtight manner. In this way, it is ensured that the dust extraction apparatus 16 operates properly.

(17) FIG. 4 shows a possible complete closure for the maintenance tunnel 20. FIG. 4 shows a closure element 25, the shape of which is adapted to the inner space in the maintenance tunnel 20. The closure element 25 likewise comprises the maintenance cover 15 and also comprises a plug 26. The plug 26 is in particular designed such that it closes the tunnel exit opening 34 of the maintenance tunnel 20, in particular at least substantially in an airtight manner, when the closure element 25 is inserted into the maintenance tunnel 20. At the same time, the maintenance cover 15, which the closure element 25 also comprises, closes the tunnel entrance opening 33 in this position. The closure element 25 therefore comprises both the maintenance cover 15 and the plug 26, which are interconnected. This does not have to be produced by the cylindrical configuration shown in FIG. 4, but instead different designs can also be used. It is only important that the closure element 25 together with the maintenance cover 15 closes the tunnel entrance opening 23 and simultaneously the tunnel exit opening 34 by means of the plug 26. In this closed position of the closure element 25, the plug 26 is in particular arranged so as to be flush with the extraction hood 19. This means that the plug 26 does not project or protrude into the extraction hood 19. In this way, the flow conditions in the extraction hood 19 are not influenced by the plug 26. At the same time, any influence through the maintenance tunnel 20 via the tunnel exit opening 34 is likewise prevented. Overall, when the closure element 25 is closed, the same flow conditions therefore prevail in the extraction hood 19 that would prevail without the maintenance tunnel 20. At the same time, dirt is prevented from penetrating into the maintenance tunnel 20 via the tunnel exit opening 34.

(18) The closure element 25 and/or the maintenance cover 15 may likewise comprise a locking element 31, by means of which the closure element 25 and/or the maintenance cover 15 can be held in the closed position. For example, the locking element 31 may be a thread and/or a lock.

(19) In order to prevent the dust extraction apparatus 16 from being operated when one of the maintenance tunnels 20 is open, according to a preferred embodiment, it is possible that a closure sensor 35 is provided. In particular, a separate closure sensor 35 is provided for each maintenance tunnel 20. The closure sensor 35 detects whether or not the maintenance cover 15 or closure element 25 is in the closed position. If all the maintenance covers 15 or closure elements 25 are not in the closed position, a warning can be displayed to the operator on the driver's platform 2 of the ground milling machine 1. For this purpose, the closure sensors 35 are connected to a control unit of the ground milling machine 1 or the on-board computer thereof. Additionally or alternatively, it may also be provided that the dust extraction apparatus 16 can only be operated when all the maintenance covers 15 or closure elements 25 are in the closed position and the maintenance tunnels 20 are closed.

(20) FIG. 7 is a flow diagram of the method 50 according to the invention. The method 50 begins by opening 51 a maintenance tunnel 20, for example by opening a maintenance cover 15 or by removing a closure element 25 from the maintenance tunnel 20. The maintenance tunnel 20 then opens an access connection between the outside of the ground milling machine 1, for example one of the side walls 23, 24, the front wall 29 or the rear wall 32 of the ground milling machine 1, and the extraction region of the dust extraction apparatus 16. Next, maintenance 52 or cleaning of the extraction region can therefore be carried out through the maintenance tunnel 20. This can preferably be performed easily by an operator standing on the ground 8 beside the ground milling machine 1, since the maintenance tunnels 20 are arranged vertically above the ground 8 at a height that is easy to reach. For example, a blockage in the extraction region, for example the extraction opening, can be flushed free using a maintenance tool such as a pressure washer. Finally, the maintenance tunnel 20 is then closed 53 on the relevant side of the ground milling machine. Here, in particular the maintenance cover 15 and/or the closure element 25 are brought into the closed position, meaning that the tunnel entrance opening 33 and/or the tunnel exit opening 34 are closed in an airtight manner Overall, the invention therefore greatly simplifies the cleaning of the extraction region of the dust extraction apparatus 16 of the ground milling machine 1, meaning that both the safety and comfort of the operator and the cost-effectiveness of the work operation of the ground milling machine 1 are improved.