Tunnel cleaning device

Abstract

The invention relates to a cleaning device for the dry cleaning of a tunnel, comprising a feeding device for feeding a flow of air to a surface being cleaned, wherein the feeding device has an exit opening, through which the flow of air emerges from the feeding device, and a removal device comprising at least one removal pipe with a free end with an opening for suctioning away direct or trash from the surface with the opening of the free end in a first direction. The feeding device is arranged such that the flow of air from the exit opening emerges from the feeding device in a second direction toward the opening of the free end of the removal pipe and impinges on the surface. The first direction is oriented at an angle between 45 and 80 to the second direction.

Claims

1. Cleaning device for the dry cleaning of a tunnel, comprising a) a feeding device for feeding a flow of air to a surface being cleaned, wherein the feeding device has an exit opening, through which the flow of air emerges from the feeding device b) a removal device comprising several removal pipes arranged in a row alongside each other, each removal pipe having a free end with an opening for suctioning away dirt or trash from the surface with the opening of the free end in a first direction, wherein the feeding device is arranged such that the flow of air from the exit opening emerges from the feeding device in a second direction toward the opening of the free end of the removal pipe and impinges on the surface, the first direction being oriented at an angle between 45 and 80 to the second direction and wherein each of the removal pipes comprises an end element at an end of the removal pipe, the end element being directed toward the surface being cleaned, wherein an end element of a first of the removal pipes is movable relative to an end element of a second of the removal pipes.

2. Cleaning device according to claim 1, wherein the removal pipe comprises an end element at an end of the removal pipe directed toward the surface being cleaned, wherein the end element is movable relative to the feeding device.

3. Cleaning device according to claim 1, wherein the removal pipe has a flexible region after the end element in the suction direction and then a rigid region, so that the end element can swivel relative to the rigid region of the removal pipe.

4. Cleaning device according to claim 1, wherein the removal pipe has an inner diameter between 5 and 30 cm.

5. Cleaning device according to claim 4, wherein the removal pipe has an inner diameter between 8 and 20 cm.

6. Cleaning device according to claim 1, wherein the feeding device comprises several feed pipes for the feeding of the flow of air.

7. Cleaning device according to claim 1, wherein a brush is arranged in an end region of the removal pipe, for brushing off the surface being cleaned.

8. Cleaning module comprising a cleaning device according to claim 1, a compressed air source for generating an air pressure in the feeding device, a suction device for generating a partial vacuum in the removal device, and a container to hold the suctioned dirt and trash.

9. Cleaning module according to claim 8, wherein the volume flow for the feeding device generated by the compressed air source is between 1000 m.sup.3/h and 4000 m.sup.3/h.

10. Cleaning module according to claim 8, wherein the suction power generated for the removal device by the suction device is between 20,000 m.sup.3/h and 60,000 m.sup.3/h.

11. Cleaning module according to claim 8, comprising a chamber formed by four side walls and a cover, wherein at least one lower end region of the removal device and a lower end region of the feeding device are enclosed by the chamber, wherein a pressure can be generated in the chamber which is less than atmospheric pressure.

12. Cleaning module according to claim 8, comprising a detection device for detecting obstacles, an evaluation unit and a drive for adjusting the removal device in the vertical direction relative to the feeding device, wherein the detection device is designed to send signals to the evaluation unit and wherein the evaluation unit is designed to control the drive in dependence on the signals.

13. Rail vehicle comprising a cleaning module according to claim 8.

14. Rail vehicle according to claim 13, wherein the rail vehicle comprises at least four wheels each with a running surface, wherein the free end of the removal pipe can be lowered past the lowermost point on the running surface of a wheel by at least 15 cm, preferably at least 20 cm, in the vertical direction.

15. Cleaning device according to claim 1, wherein the several removal pipes are arranged in a row alongside each other.

16. Cleaning device according to claim 1, comprising at least 10 removal pipes per meter.

17. Cleaning device according to claim 16, comprising at least 20 removal pipes per meter.

18. Method for the dry cleaning of a tunnel with a cleaning device according to claim 1, involving the steps of positioning of the cleaning device relative to the surface being cleaned, moving the cleaning device relative to the surface along a longitudinal axis of the tunnel, during the movement, feeding a flow of air onto the surface, so that dirt or trash is loosened from the surface, and during the movement, removing the loosened dirt or trash from the surface with a removal device.

19. Method according to claim 18, wherein at least one removal pipe of several removal pipes of the removal device is moved during the cleaning of the tunnel in a direction relative to the surface and relative to another one of the removal pipes which is different from the longitudinal axis of the tunnel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings used to explain the sample embodiment show:

(2) FIG. 1A a view of a cross section through a railroad tunnel, in which a rail vehicle according to the invention is situated with a cleaning module according to the invention,

(3) FIG. 1B a side view of the rail vehicle with the cleaning unit for the rail bed,

(4) FIG. 2A a schematic representation of the cleaning unit for the tunnel wall,

(5) FIG. 2B a side view of the cleaning unit for the tunnel wall,

(6) FIG. 2C a diagonal view of the cleaning unit for the tunnel wall,

(7) FIG. 2D a diagonal view of a further embodiment of the cleaning unit for the tunnel wall,

(8) FIG. 2E a side view of the further embodiment of the cleaning unit for the tunnel wall,

(9) FIG. 3 a schematic representation of the cleaning unit for the shoulder,

(10) FIG. 4 a schematic representation of the cleaning unit for the rail bed,

(11) FIG. 5 a perspective representation of the cleaning unit for the rail bed on the rail vehicle,

(12) FIG. 6 a detail view of an area of the cleaning unit for the rail bed,

(13) FIG. 7 a view of the cleaning unit for the rail bed with lowered and extended chamber in the cleaning position, and

(14) FIG. 8 a view of the cleaning unit transversely to the travel direction.

(15) Basically, the same parts are provided with the same reference numbers in the figures.

WAYS OF IMPLEMENTING THE INVENTION

(16) FIG. 1A shows a view of a cross section through a railroad tunnel, in which a rail vehicle 10 according to the invention is situated. The rail vehicle 10 is shown from the rear.

(17) The rail vehicle 10 comprises several cars. On one car is arranged a cleaning module 1 according to the invention. This comprises a cleaning device having a tunnel wall cleaning unit 100, a shoulder cleaning unit 200 and a rail bed cleaning unit 300. The cleaning devices each comprise a feeding device for feeding a flow of air to the surface being cleaned and a removal device with removal pipes for sucking up dirt and trash from the surface in the tunnel. Moreover, the cleaning module 1 comprises a blower for generating a partial vacuum in the removal pipes, a compressor for generating an air pressure in feed lines of the feeding devices of the cleaning units 100, 200, 300 as well as a dirt container 13 for catching and collecting the suctioned dirt and trash, as can be seen in FIG. 1B. For this, the cleaning units 100, 200, 300 are connected by means of flexible pipelines 11 to the dirt container 13. On the same car there is furthermore arranged a driver's position 14. A user can steer the cleaning units 100, 200, 300 here. The rail vehicle 10 further comprises a flatbed car, on which further dirt containers 13 are placed, which can be swapped out for the dirt container 13 which is connected to the cleaning devices 100, 200, 300. Other cars of the rail vehicle 10 contain passenger cabins or cargo space.

(18) In FIG. 1B one can see the car of the rail vehicle 10 on which the cleaning unit 300 is arranged. In this representation, one notices that the dirt container 13 is arranged on the car in front of the cleaning unit 300 for the rail bed, looking in the travel direction 2. The driver's position 14 is located on the car behind the cleaning unit 300, looking in the travel direction 2.

(19) For the cleaning of the railroad tunnel, the cleaning units 100, 200, 300 are positioned with respect to a surface being cleaned 20 in the tunnel and the blower and the compressor are switched on. After this, the rail vehicle 10 moves through the tunnel at a walking pace, the cleaning units 100, 200, 300 being moved along the inner tunnel surfaces.

(20) FIGS. 2 to 4 each show a schematic representation of the three cleaning units 100, 200, 300 for the tunnel wall, for the shoulder and for the rail bed. The function of these cleaning units shall be described in detail hereafter.

(21) FIG. 2A shows schematically the cleaning unit 100 for the tunnel wall. FIG. 2B shows a side view, and FIG. 2C a diagonal view of the cleaning unit 100 for the tunnel wall.

(22) The travel direction 2 of a vehicle carrying this cleaning unit 100 is indicated by an arrow. As is evident from FIG. 2, this cleaning unit 100 for the tunnel wall comprises a feeding device in the form of feed pipes 110 to for supplying a flow of air 130 to the surface being cleaned. At a free end 111, pointing toward the surface, each feed pipe 110 has a nozzle 113, through which a flow of air emerges from the feed pipe 110 and is guided onto the surface 20 being cleaned. The cleaning unit 100 furthermore comprises a removal device with a removal pipe 120 for taking away the dirt or trash from the surface. The removal pipe has a suction mouth 122 at its free end 121 directed toward the surface. Moreover, a brush 123 surrounding the suction mouth 122 is arranged at this free end 121 of the removal pipe 120, which brushes off the surface being cleaned 20 during the operation of the cleaning unit 100 and borders the suction channel at least partly in the travel direction 2. The feed pipe 110 is mounted by a joint 112 in the region of the free end of the removal pipe 121 so as to be able to swivel, so that the free end of the feed pipe 111 can be swiveled relative to the free end of the removal pipe 121.

(23) Preferably, the suction mouth 122 of the removal pipe 120 is substantially rectangular or oblong oval in configuration and has several feed pipes 110 at a rear long side, in the travel direction 2, so that several flows of air 130 can be directed onto the surface 20 being cleaned per each removal pipe 120. The suction mouth 122 is connected by the removal pipe, which is designed as a flexible removal pipeline, to the dirt container 13 and the blower on the rail vehicle 10. The dirt and trash sucked up is thus sucked through the suction mouth 122 and arrives in the dirt container 13 through the removal pipeline.

(24) The cleaning module 1 comprises a holding device with drive unit (not shown) for the cleaning unit 100 for the tunnel wall. By means of the holding device, the removal pipe 120 and the feed pipes 110 of the tunnel wall cleaning unit are held on the rail vehicle 10. The holding device comprises a telescopic arm, which is mounted at an inner end on the rail vehicle 10 and carries at its outer end the free end of the removal pipe 121 and the feed pipes 110 mounted on the removal pipe. In this way, the free end of the removal pipe 121 can be moved with respect to the rail vehicle 10. Thus, the free end of the removal pipe 121 with the suction mouth 122 can be moved transversely to the travel direction of the rail vehicle 10 away from the rail vehicle 10 or toward the rail vehicle. Furthermore, the free end of the removal pipe 121 can be swiveled about a rotational axis. Thanks to this adjustability, the cleaning unit 100 can be oriented precisely toward the tunnel wall or toward the tunnel ceiling, so that the brush 123 touches the surface 20. This adjustment occurs by means of the drive unit of the holding device. For this, the drive unit comprises one electric motor each for extension and retraction of the telescopic arm and for swiveling of the free end of the removal pipe 121. The electric motors can be controlled by the operator at the driver's position 14 of the rail vehicle 10 or by an automatic control system.

(25) For the cleaning of the tunnel, the cleaning unit 100 for the tunnel wall is taken up to the surface 20 of the tunnel wall or the tunnel ceiling, so that the brush 123 touches the surface 20 of the tunnel. Since the brush 123 comprises flexible bristles, small obstacles such as cable ducts and signs can be driven over with the brush 123, without having to move the cleaning unit 100 away from the surface 20. As the feed pipes 110 are mounted movably on the removal pipe 120, they are briefly pushed away from the surface 20 when driving over obstacles and in this way suffer no damage.

(26) Since the brush 123 which is arranged at the free end of the removal pipe 121 is arranged partly in front of the suction mouth 122 of the removal pipe 120, looking in the travel direction 2, it first brushes off this surface 20 being cleaned, before the suction mouth 122 sucks up the dust and the loosened dirt particles. In order for the dust and loosened dirt to be sucked in by the removal pipe 120, the blower of the cleaning module on the rail vehicle 10 generates a partial vacuum, so that a suction flow is created at the free end of the removal pipe 121. The suction power of the blower in this case is around 90,000 m.sup.3/h in total.

(27) The flow of air 130 conducted in the feed pipes 110 is under a pressure of around 6000 Pa. This pressure is generated by the compressor on the rail vehicle 10. The flow of air 130 emerges through the nozzle 113 of the feed pipe 110 and impinges on the surface 20 being cleaned in the direction of the suction mouth 122 of the removal pipe 120. In this way, on the one hand the dirt is loosened from the surface 20 and on the other hand it is blown in the direction of the suction mouth 122. In this process, the longitudinal axis of an end region of the feed pipe 110 stands at an acute angle to the longitudinal axis of an end region of the removal pipe 120. By orienting the end region of the removal pipe 120, the dust and the dirt are sucked up from the surface in a first direction. The flow of air 130 emerging from the exit opening of the feed pipe 110 is directed toward the suction mouth 122 of the free end of the removal pipe 121 and impinges on the surface in a second direction. The first direction is oriented at an angle between 45 and 80 to the second direction.

(28) In FIGS. 2D and 2E, a further embodiment of the cleaning unit 101 for the tunnel wall is represented. By contrast with the above described embodiment, this cleaning unit 101 has a rotating brush roller 102. The brush roller 102 is driven by an electric motor 103, which is arranged on a housing of the brush roller 102. As can be seen in FIG. 2E, the brush roller 102 rotates in a direction contrary to the travel direction 2 of the rail vehicle 10. In this way, even dirt very strongly attached to the surface can be loosened from the surface of the tunnel wall or tunnel ceiling.

(29) FIG. 3 represents schematically the cleaning unit 200 for the rail shoulder. This comprises a feeding device in the form of a feed pipe 210 and a removal device in the form of a removal pipe 220, having a suction opening 222 at its free end 221. In the area of a free end 211, the feed pipe 210 is connected immovably to the free end 221 of the removal pipe 220 (not represented). During operation, the longitudinal axis of the end region of the removal pipe 220 is oriented substantially at right angles to the surface 20 of the tunnel. The supplied flow of air 230 emerges in the front region of the feed pipe 210 through a nozzle 213 and impinges on the surface 20 being cleaned in the direction of the suction opening 222 of the removal pipe 220. The feed pipe 210 is located behind the removal pipe 220, looking in the travel direction, wherein the emerging flow of air 230 is conducted in the travel direction 2 toward the surface 20.

(30) The angle between the direction in which the flow of air 230 impinges on the surface and the direction in which the dirt is sucked up by the removal pipe 220 lies in the range of 45 to 80.

(31) As described above for the cleaning unit 100 for the tunnel wall, the dirt in the shoulder is loosened by the supplied flow of air 230 and sucked up with the suction opening 222 of the removal pipe 220. The suction opening 222 has a round circular cross section, preferably with an inner diameter between 20 cm and 40 cm. The removal pipe 220 has, in the area of its free end 221, an end section 224 made of a stiff material, such as steel sheeting. This end section 224 is conical in configuration (not represented in FIG. 3) and is connected by a flexible removal pipeline to the dirt container 13 and the blower on the rail vehicle 10. The end section 224 is secured by means of two chains to a structure on the rail vehicle 10 such that the end section 224 and thus the suction opening 222 and the free end of the feed pipe 211 can be moved in the vertical direction with respect to the shoulder.

(32) FIG. 4 shows schematically the cleaning unit 300 for the rail bed. This has several feed pipes 310 and several removal pipes 320. The feed pipes 310 are arranged, looking in the travel direction, in front of and behind the removal pipes 320, and also transversely to the travel direction at the side of the removal pipes 320, as can be seen from FIGS. 5 and 6.

(33) The removal pipes 320 are arranged in two rows alongside each other transversely to the travel direction. In the sample embodiment shown, the cleaning unit 300 for the rail bed comprises two groups of 15 removal pipes 320 each in the form of removal pipe units 350.1, 350.2. This arrangement of the removal pipes 320 can be seen in FIGS. 5 and 7 and is described in detail below.

(34) Each removal pipe 320 has an inner diameter of 10 cm, the outer diameter being slightly larger. This produces a maximum width covered by the removal pipes 320 of over 4 m. Furthermore, each removal pipe 320 has an end element 325 in the area of its free end, which is formed from a stiff material, such as steel sheeting. The end element 325 has a circular round cross section and forms a suction mouth 322 for sucking up the dirt and trash from the surface. Looking in the suction direction, a flexible section 326 is arranged behind the end element 325, comprising a bellows, making possible a lengthwise contraction (cf. FIGS. 5-7). The flexible sections 326 of several removal pipes 320 are joined by a hood 327. The hood 327 together with the removal pipes 320 forms a removal pipe unit 350.1, 350.2, which preferably comprises 10-15 removal pipes 320. The hood 327 of each removal pipe unit 350.1, 350.2 is connected by a main removal pipe 351 to the dirt container 13 and the blower on the rail vehicle 10.

(35) Thanks to the flexible bellows section 326, the end elements 325 of the removal pipes 320 can be raised and lowered in the vertical direction with respect to the hood 327 by cable pulleys individually and independently of the other end elements 325. This adjustment is done by lifting or lowering an end element 325 by means of two cables, fastened to the end element 325, in the vertical direction. The cables may also be activated by the operator in the driver's position 14 in order to be able to move the end elements 325 during operation. In other embodiments, the end elements 325 may also be lifted or lowered by means of an electrical, hydraulic or pneumatic drive unit. An individual end element 325 can be lifted by a maximum of 30 cm relative to the other end elements 325. In this way, the end elements 325 can be lifted or lowered individually and independently of each other in the area of a track switch or an obstacle, in order to clean the subgrade in precise manner. Furthermore, the hood 327 together with the removal pipes 320 can be moved as a whole relative to the rail vehicle 10. This adjustment option shall be described in detail further below in connection with FIGS. 5 and 6.

(36) The flexible section 326 moreover enables a swiveling of the respective removal pipe 320 if its end element 325 touches an obstacle.

(37) As is indicated schematically in FIG. 4, the area of the free ends of the feed pipes 310, the end elements 325 and the flexible sections 326 of the removal pipes 320 are surrounded by a chamber 340. This comprises four side walls and a cover. In the chamber 340, a partial vacuum of around 40,000 Pa can be generated. The lower regions of the side walls of the chamber 340 are formed from elastic aprons. In this way, the entire chamber 340 with the cleaning unit 300 can be lowered onto the rail bed, so that the elastic aprons are pushed away by the rails in the area of the rails.

(38) As with the cleaning unit 100 for the tunnel wall and the cleaning unit 200 for the shoulder, the feed pipes 310 of the cleaning unit 300 for the rail bed serve for loosening the dirt from the surface being cleaned with a flow of air 330. The loosened dirt is sucked up from the surface by the suction mouths 322 of the removal pipes 320 in a first direction. The flow of air 330 emerging from a nozzle 313 in the feed pipe 310 is directed toward the suction mouths 322 and impinges on the surface in a second direction. The first direction is oriented at an angle between 45 and 80 to the second direction.

(39) FIG. 5 shows a perspective view of the cleaning unit 300 for the rail bed according to the invention, mounted on the rail vehicle 10. A circle marks a feature which is shown enlarged in FIG. 6.

(40) Furthermore, one can see in FIG. 5 the chamber 340 which is arranged on an underside of the rail vehicle 10 and which has a rectangular base area. The bordering edge of the chamber 340 comprises four vertically oriented side walls, which are formed by elastic aprons (cf. FIG. 6). These are arranged in two halves, which can be moved relative to one another in the horizontal direction, transversely to the travel direction. In this way, the base area or the volume of the chamber 340 can be altered. The aprons are fastened on a framelike linkage 341. At the top, the chamber is closed by a (transparent) cover.

(41) In FIG. 5 it can be seen that the feed pipes 310 are arranged along the four side walls of the chamber 340. For simplicity, FIGS. 5-8 only represent the frontmost regions of the free ends of the feed pipes 310. The feed pipes 310 are fastened on the framelike linkage 341 and can swivel, so that they swivel away when they touch an obstacle. The respective outlets of the feed pipes 310 point toward the middle of the chamber 340 to the removal pipes 320 situated there. In this way, the dirt and dust during operation is blown by the flow of air 330 from the feed pipes 310 in the travel direction as well as transversely to the travel direction toward the suction mouths 322 of the removal pipes 320 in the chamber 340.

(42) Furthermore, the two removal pipe units 350.1, 350.2 empty into the chamber 340. For this, the respective hood 327 of the removal pipe units 350.1, 350.2 is connected to the framelike linkage 341 of the chamber 340. Moreover, one can see in FIG. 5 the main removal pipes 351 which connect each of the removal pipe units 350.1, 350.1 to the dirt container 13.

(43) As can be seen in FIG. 5, the cleaning unit 300 for the rail bed comprises an adjusting device 370 for adjusting the removal pipe units 350.1, 350.2 with respect to the rail vehicle 10. For this, the adjusting device 370 contains two transversely extending linear guides, along which the removal pipe units 350.1, 350.2 can be displaced transversely to the travel direction of the rail vehicle 10. The removal pipe units 350.1, 350.2 are displaced manually by hand or by means of an electric, hydraulic, or pneumatic drive unit. Thus, each removal pipe unit 350.1, 350.2 can be moved outward from the middle of the vehicle on one side. Here, the two halves of the chamber 340 are likewise moved to the outside with respect to one another. The removal pipe units 350.1, 3502 can be moved outward from the middle of the vehicle until the rows of removal pipes 320, looking in the travel direction, no longer overlap, so that all removal pipes 320 are arranged alongside each other, as can be seen in FIG. 7.

(44) Moreover, the adjusting device 370 comprises hoists, with which the chamber 340 together with both removal pipe units 350.1, 350.2 can be raised or lowered in the vertical direction relative to the rail bed. In addition to this adjustment option, each removal pipe unit 350.1, 350.2 comprises the cable pulleys described above in connection with FIG. 4 so as to move the end elements 325 of the removal pipes 320 individually and independently of each other. The adjusting device 370 moreover comprises electric motors for operating the cable pulleys and for moving the removal pipe units 350.1, 350.2 along the guides. The electric motors may in this case be controlled by the operator from the driver's position 14. Moreover, the cable pulleys for the individual removal pipes 340 may also be operated from the driver's position 14. Alternatively, the end elements 325, as mentioned above, may also be raised or lowered by means of an electric, hydraulic or pneumatic drive unit.

(45) Moreover, from the driver's position 14 the operator can also control the compressor for generating the air pressure in the feed pipes 110, 210, 310 and the blower for generating the suction power in the removal pipes 120, 220, 320. The compressor generates an air pressure of 600,000 Pa and achieves a volume flow of around 2100 m.sup.3/h. The blower achieves a suction power of 90,000 m.sup.3/h.

(46) While FIG. 6 shows the position of the cleaning unit 300 for the rail bed in a ready position, in which the chamber 340 has been raised, FIG. 7 shows the position of the cleaning unit 300 for the rail bed during the cleaning of the rail bed, where the chamber 340 finds itself in a lowered cleaning position. In the cleaning position shown, the two halves of the chamber 340 have been moved apart from each other transversely to the travel direction and the two removal pipe units 350.1, 350.2 are likewise moved apart from each other transversely to the travel direction, so that the removal pipe units 350.1, 350.2 are arranged alongside each other and in this way the removal pipes 320 can cover a maximum width of the rail bed.

(47) In the cleaning position, even small obstacles like signals or signs which stick out at most by 30 cm from the subgrade can be driven over without having to raise the chamber 340. Since the feed pipes 310 are mounted movably on the framelike linkage 341, they are briefly swiveled upward by the obstacle. The same thing occurs with the end elements 325 of the removal pipes 320. These can be pushed away by an obstacle, thanks to the flexible section 326, without suffering damage. They automatically return to their working position by virtue of gravity, once the obstacle has been driven over.

(48) The cleaning unit 300 for the rail bed can be lowered so that the free ends of the feed pipes 310 and the removal pipes 320 are close to the gravel bed or the fixed bed of the rails, preferably up to 2 cm above it. Thanks to the described arrangement of the removal pipes 320 and the adjustment possibility of the individual end elements 325, the rail bed can also be cleaned thoroughly in the area of a track switch, since the end elements 325 of the removal pipes 320 can be individually raised or lowered in order to adjust the suctioning surface exactly to the subgrade.

(49) The adjusting of the end elements 325 can be done manually. In another embodiment, however, the adjustment can also be automatic. For this, the cleaning module 300 has sensors arranged in front of the removal pipes 320 in the travel direction for detecting the rail bed and a control unit for evaluating the sensor signals and for controlling the adjusting device 370. In this embodiment, the subgrade is monitored by the sensors constantly when driving over the subgrade. If an obstacle is identified, the control unit moves the individual end elements 325 of the removal pipes 320. Thus, for example, individual end elements 325 are raised when the rail vehicle 10 is traveling over a track switch, or a larger obstacle stands in the way.

(50) FIG. 8 shows a view of the cleaning unit 300 transversely to the travel direction. One can see in particular the feed pipes 310, which are arranged along the border of the chamber 340. Their mouths are positioned beneath a rolling plane defined by the rail head 23. The aprons, which form the side walls of the chamber 340, moreover reach almost down to the firm roadway 22, so that a partial vacuum can be built up inside the chamber 340 with a relatively low suction power. Some of the feed pipes 310 are arranged on the outside of the chamber 340 on a framelike linkage 341. Their mouth points toward the lowermost region of the tunnel wall 21. The compressed air put out by these feed pipes loosens dust and dirt in this area. Because of the partial vacuum in the chamber 340, this dust and dirt is also sucked into the chamber 340 and thus removed.

(51) In summary, the cleaning device according to the invention enables an efficient and at the same time a thorough cleaning of a tunnel.