Self-propelled road milling machine

Abstract

The road milling machine according to the invention comprises a cleaning device which has a cleaning unit arranged in front of the work roller in the working direction. The cleaning unit ensures that the surface of the terrain over which the wheels or running gears travel is clear of material. As a result, an optimum milling result is always achieved. The invention takes effect in particular when using small millers which have at least one rear wheel or running gear which can be moved into an inner working position in relation to a longitudinal side of the machine frame and into an outer working position in relation to a longitudinal side of the machine frame. In this preferred embodiment, the cleaning device comprises a pivot device which is designed in such a way that the cleaning unit can be moved into an inner working position in relation to a longitudinal side of the machine frame and into an outer working position in relation to a longitudinal side of the machine frame. In the inner or outer working position, the cleaning unit is arranged on the same track as the rear wheel or running gear which can be moved into the inner or outer working position. This ensures that the track of the rear wheel or running gear is clear of milled material or other dirt, wherein the cleaning unit does not protrude too far beyond the rear wheel or running gear.

Claims

1. A self-propelled civil engineering machine, comprising: a machine frame; at least two rear ground engaging supports and at least one front ground engaging support configured to support the machine frame from a ground surface, at least one of the rear ground engaging supports being a movable rear ground engaging support movable into an inner support working position in relation to a longitudinal side of the machine frame and into an outer support working position in relation to the longitudinal side of the machine frame; a working roller arranged between the rear ground engaging supports; and a cleaning assembly including a cleaning tool arranged in front of the working roller in a working direction, the cleaning unit being configured to remove material from a portion of the ground surface over which the movable rear ground engaging support will travel in at least the outer support working position.

2. The machine of claim 1, wherein the cleaning tool comprises a sweeping tool.

3. The machine of claim 2, wherein the sweeping tool has a working width at least as wide as the movable rear ground engaging support.

4. The machine of claim 2, wherein the sweeping tool comprises a disc brush.

5. The machine of claim 4, wherein: the cleaning assembly includes a pivot assembly configured such that a work angle of the disc brush can be adjusted about at least one axis.

6. The machine of claim 1, further comprising: lifting mechanisms connecting the rear ground engaging supports to the machine frame so that a height of the rear ground engaging supports can be adjusted relative to the machine frame.

7. A self-propelled civil engineering machine, comprising: a machine frame; at least two rear ground engaging supports and at least one front ground engaging support configured to support the machine frame from a ground surface, at least one of the rear ground engaging supports being a movable rear ground engaging support movable into an inner support working position in relation to a longitudinal side of the machine frame and into an outer support working position in relation to the longitudinal side of the machine frame; a working roller arranged between the rear ground engaging supports; and a cleaning assembly including a cleaning tool arranged in front of the working roller in a working direction; wherein the cleaning assembly includes a pivot assembly configured such that the cleaning tool can be moved into an inner tool working position in relation to the longitudinal side of the machine frame and into an outer tool working position in relation to the longitudinal side of the machine frame.

8. The machine of claim 7, wherein: the pivot assembly is configured such that when the cleaning tool is in the inner tool working position or the outer tool working position, the cleaning tool is substantially arranged on a same track as the at least one movable rear ground engaging support in its inner support working position or outer support working position, respectively.

9. The machine of claim 7, wherein: the pivot assembly is configured such that in the outer tool working position the cleaning tool is arranged in the working direction between the at least one front ground engaging support and the rear ground engaging supports.

10. The machine of claim 7, wherein: the pivot assembly is configured such that in the inner tool working position the cleaning tool is arranged in the working direction in front of the at least one front ground engaging support.

11. The machine of claim 7, wherein: the pivot assembly is configured such that in the inner and outer tool working positions the cleaning tool is floatingly mounted such that the cleaning tool rests on the ground surface with a predetermined contact force.

12. The machine of claim 7, wherein: the pivot assembly is configured such that the cleaning tool can be moved into an idle position in which the cleaning tool does not rest on the ground surface.

13. A self-propelled civil engineering machine, comprising: a machine frame; at least two rear ground engaging supports and at least one front ground engaging support configured to support the machine frame from a ground surface, at least one of the rear ground engaging supports being a movable rear ground engaging support movable into an inner support working position in relation to a longitudinal side of the machine frame and into an outer support working position in relation to the longitudinal side of the machine frame; a working roller arranged between the rear ground engaging supports; and a cleaning assembly including a disc brush arranged in front of the working roller in a working direction; wherein: the movable rear ground engaging support is a right rear ground engaging support; and the cleaning assembly includes a pivot assembly configured such that: the disc brush can be moved into an outer tool working position on a right-hand side of the machine frame, and relative to the working direction behind the at least one front ground engaging support and in front of the rear ground engaging supports, the disc brush being rotatably driven counter-clockwise; and the disc brush can be moved into an inner tool working position on a right-hand side of a longitudinal axis of the machine frame, and relative to the working direction in front of the at least one front ground engaging support, the disc brush being rotatably driven counter-clockwise.

14. A self-propelled civil engineering machine, comprising: a machine frame; at least two rear ground engaging supports and at least one front ground engaging support configured to support the machine frame from a ground surface, at least one of the rear ground engaging supports being a movable rear ground engaging support movable into an inner support working position in relation to a longitudinal side of the machine frame and into an outer support working position in relation to the longitudinal side of the machine frame; a working roller arranged between the rear ground engaging supports; and a cleaning assembly including a cleaning tool arranged in front of the working roller in a working direction; wherein: the cleaning assembly includes a pivot assembly including: a first pivot arm pivotally connected to the machine frame such that the first pivot arm can pivot relative to the machine frame about a vertical axis; a second pivot arm pivotally connected to the first pivot arm such that the second pivot arm can pivot relative to the first pivot arm about a first horizontal axis; and wherein the cleaning tool is pivotally connected to the second pivot arm such that the cleaning tool can pivot relative to the second pivot arm about a second horizontal axis.

15. The machine of claim 14, wherein: the pivot assembly further includes a lever assembly, the lever assembly including: first and second lever arms, the first lever arm being rotatably connected to the second pivot arm and to the second lever arm, the second lever arm also being rotatably connected to the first pivot arm; and a piston and cylinder arrangement including a first end rotatably connected to both the first and second lever arms, and a second end rotatably connected to the first pivot arm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment of the invention is explained in more detail hereinafter with reference to the drawings, in which:

(2) FIG. 1 is a side view of a road milling machine,

(3) FIG. 2 is a simplified schematic plan view of the road milling machine in FIG. 1, wherein the cleaning unit is in the outer working position,

(4) FIG. 3 shows the road milling machine, wherein the cleaning unit is in the inner working position,

(5) FIG. 4 shows the road milling machine, wherein the cleaning unit is in the idle position and the right-hand rear wheel is in the outer working position,

(6) FIG. 5 shows the road milling machine, wherein the cleaning unit is in the idle position and the right-hand rear wheel is in the inner working position,

(7) FIG. 6 is a side view of the cleaning device,

(8) FIG. 7 is a plan view of the cleaning device, wherein the cleaning unit is pivoted backwards in the working direction, and

(9) FIG. 8 is a plan view of the cleaning device, wherein the cleaning unit is pivoted forwards in the working direction.

DETAILED DESCRIPTION

(10) FIG. 1 is a side view of an embodiment of a road miller, in this case a small miller. The road miller comprises a machine frame 1 which is supported by a chassis 2. The chassis 2 comprises in the working direction A a front right-hand wheel 3R and a front left-hand wheel 3L and a rear right-hand wheel 4R and a rear left-hand wheel 4L. However, caterpillar tracks may also be provided in place of wheels. The wheels or caterpillar tracks may be referred to as ground engaging supports.

(11) The road miller comprises a working device having a work roller (5) which is a milling roller equipped with milling tools. The milling roller (5) is arranged in a milling roller housing 6 which is closed by an edge protector 7R (7L) on both the left-hand and right-hand side in the working direction A. The operator's platform 8 is arranged above the milling roller housing 6. A transport device 9 (only shown in part) is arranged at the rear of the road miller, behind the milling roller (5) in the working direction A, and comprises a conveyor belt which is used to carry away the material removed by the milling tools in the milling roller housing 6.

(12) The road miller further comprises a device 10 for lifting or lowering the rear left-hand and right-hand wheels 4R, (4L), which rest on the ground, relative to the machine frame 1. The device 10 for lifting or lowering wheels comprises a lifting device 10R associated with the right-hand wheel 4R and a lifting device (10L) associated with the left-hand wheel (4L). In order to set the milling depth, the height of the rear wheels is adjusted relative to the machine frame 1, and therefore the milling roller (5) can penetrate the ground material 11.

(13) FIGS. 2 to 5 are simplified schematic views of the road miller in FIG. 1, wherein corresponding parts are provided with the same reference signs. In the road miller, the right-hand rear wheel 4R in the working direction A is pivotally mounted. The rear right-hand wheel 4R can be moved out of an outer working position in relation to the right-hand longitudinal side 1R of the machine frame 1 into an inner working position in relation to the right-hand longitudinal side 1R of the machine frame 1. In the outer working position shown in FIG. 2, the two rear wheels 4R, 4L are located on a common axis 13, wherein the milling roller 5 is arranged between the rear wheels 4R, 4L with its axis substantially in the same vertical plane as the rear wheels. In the inner working position, the rear right-hand wheel 4R is arranged in front of the milling roller 6 in the working direction A in a recess 14 in the machine frame 1. In this working position, the right-hand rear wheel 4R does not laterally protrude beyond the right-hand edge of the milling roller 6, and therefore the milling roller of the road miller can move closely past obstacles. The pivot mechanism for the rear wheel is described in detail in DE 196 31 042 A1 (U.S. Pat. No. 6,106,073A) for example.

(14) The road miller comprises a cleaning device 14 which is only shown schematically in FIGS. 2 to 5. The cleaning device 14 comprises a cleaning unit 15 which can be moved by means of a pivot device 16. The cleaning device 14 may be referred to as a cleaning assembly 14, and the cleaning unit 15 may also be referred to as a cleaning tool 15. The pivot device 16 may be referred to as a pivot assembly 16. In the present embodiment, the cleaning unit 15 is a sweeping unit which has a disc brush 15A. The pivot device 16 allows for the cleaning unit 15 to be moved into an outer working position, shown in FIG. 2, and into an inner working position, shown in FIG. 3. In addition, the cleaning unit 15 can be moved into an idle position which is shown in FIGS. 4 and 5.

(15) In the outer position, the disc brush 15A of the cleaning unit 15 is arranged in the working direction A on the right-hand side of the machine, to the side of the outer right-hand edge of the machine frame 1, between the front and rear wheels 3L, 3R, 4L, 4R. The axis of rotation 15B of the disc brush 15A and the right-hand rear wheel 4R are arranged on a common axis 12 which extends in parallel with the longitudinal axis 1A of the machine frame 1, and therefore the disc brush 15A is located in the track of the rear wheel 4R. Since the working region of the disc brush 15A, which is determined by the diameter of the disc brush, is larger than the width of the rear wheel 4R, the entire width of the track 17 of the rear wheel 4R is cleaned. In small millers of which the milling roller is arranged between the rear wheels, the track of the front wheel does not need to be cleaned since the front wheels lifting due to material lying in the track does not affect the milling result.

(16) If a road miller is used to machine a large surface area in a plurality of work steps, the right-hand rear wheel 4R is located in the milling track of the previous milling step, while the left-hand rear wheel 4L is in contact with the ground that is yet to be milled. The height offset between the left-hand and right-hand side is compensated by the left-hand lifting device 10L being retracted and the right-hand lifting device 10R being extended. Since the right-hand milling track is clear of milled material or other dirt, the milling roller 5 always stays at the correct height with regard to the surface of the road surface to be machined as the machine advances. The road miller is also unable to carry out lateral tilt movements because of unevenness due to milled material which could be located in the right-hand milling track.

(17) In the inner working position, the disc brush 15A of the cleaning unit 15 is arranged in front of the front wheels 3L, 3R in the working direction A. The cleaning unit 15 assumes this position when the right-hand rear wheel 4R is in the inner working position. In this position, the axis of rotation 15B of the disc brush 15A and the rear wheel 4R are once again arranged on a common longitudinal axis which extends in parallel with the longitudinal axis 1A of the construction machine, and therefore the disc brush is once again located in the track of the rear wheel 4R which is henceforth pivoted inwards. In the present embodiment, the geometric dimensions of the machine require the disc brush 15A to be pivoted slightly outwards in the inner working position in order to align the disc brush with the rear wheel. This position is shown in FIG. 3 by solid lines.

(18) In the idle position, the pivot device 16 is folded up so that it requires less space. It is then arranged on the front of the road miller (FIGS. 4 and 5).

(19) In the present embodiment, the pivot device 16 comprises hydraulic drive means (not shown in FIGS. 2 to 5). The drive means of the pivot device 16 are actuated in such a way that, in the inner and the outer working position, the disc brush 15A is floatingly mounted such that it rests on the ground with a specific contact force. A floating mounting of this type is known from the prior art.

(20) The disc brush 15A rotates anti-clockwise in the outer and inner working position. In the outer working position, the material thrown up in the previous milling step is swept to the left-hand side in front of the milling roller 5 in the working direction A by the disc brush 15A arranged between front and rear wheels 3L, 3R, 4L, 4R, and therefore the material lies in the milling track 18 of the subsequent milling step.

(21) The cleaning device 14 is described in detail with reference to FIGS. 6 to 8. The pivot device 16 of the cleaning device 14 comprises two pivot arms 19, 20. The first end of the first pivot arm 19 is mounted on a first attachment part 22, which is attached to the front right-hand corner of the machine frame 1 or is integrally formed with the machine frame, such that it can pivot about a vertical axis 21. The movement of the first pivot arm 19 in a horizontal plane allows for a pivot movement of the cleaning unit 15 either on the outside (FIG. 2) or the inside (FIG. 3). The first end of the second pivot arm 20 is attached to a second attachment part 23, which is arranged on the second end of the first pivot arm 19, such that it can pivot about a horizontal axis 24. The second attachment part 23 can either be integral with the pivot arm or can be a part fastened to the pivot arm. The movement of the second pivot arm 20 in a vertical plane allows for the cleaning unit 15 to fold upwards (FIGS. 4 and 5) or downwards (FIGS. 2 and 3) in the working direction A. Together with the disc brush 15A, the cleaning unit 15 is mounted on the second end of the second pivot arm 20 so that it can pivot about a horizontal axis 25. The disc brush 15A is used in the rear or front position such that the front region thereof contacts the ground. In this case, the disc brush 15A is pushed in the working direction A. The disc brush 15A comprises bristles 15C preferably made of polypropylene PP. The disc brush 15A is driven by a hydraulic motor 15D which sits above the brush.

(22) In order to achieve a pivot movement that is as uniform as possible when unfolding the second pivot arm 20, the pivot device 16 comprises a lever mechanism 26. The lever mechanism 26 comprises a first steering arm 27, the first end of which is connected to a central portion of the second pivot arm 20 such that it can rotate about a horizontal axis 28. A second steering arm 29 is connected to the second end of the first steering arm 27 such that it can rotate about a horizontal axis 30, the second end of which second steering arm is in turn connected to the second attachment part 23 such that it can rotate about a horizontal axis 31. The lever mechanism 26 is actuated by means of a first piston/cylinder arrangement 32, the piston 32A of which is connected to the second end of the first steering arm 27 and to the first end of the second steering arm 29 such that it can rotate about a horizontal axis 33, and the cylinder 32B of which is connected to the second attachment part 23 such that it can rotate about a horizontal axis 34. By retracting and extending the first piston/cylinder arrangement 32, the cleaning unit 15 can be raised or lowered (FIG. 6). The lever mechanism 26 may be referred to as a lever assembly 26. The first and second steering arms 27 and 29 may also be referred to as first and second lever arms 27 and 29.

(23) The work angle of the disc brush 15A can be set by means of a second piston/cylinder arrangement 35, the cylinder 35A of which is linked to the second pivot arm 20 and the piston 35B of which is linked to a lever arm 36 which is connected to the second end of the second pivot arm 20 in an articulated manner.