EP3647494A1 - Road construction machine and method for operating a road construction machine - Google Patents

Abstract

The self-propelled construction machine 1, in particular road milling machine, has a machine frame 3 on which a milling drum 10 is arranged, and at least one drive 4, 6 on the left in the working direction A and at least one drive 5, 7 on the right in the working direction A, to which lifting devices 4A, 5A, 6A, 7A, from which the machine frame 3 is supported. In addition, the construction machine has a leveling device 15 for controlling the lifting devices 4A, 5A, 6A, 7A, which is designed such that the height and / or inclination of the machine frame 3 can be adjusted with respect to the traffic area (8). The leveling device 15 provides a special control mode which is intended for the operation of the construction machine 1 in the event that a section of the route on the outside of the road 20A is to be worked. This leveling device 15 provides distance measurements for the control of the lifting devices 4A, 5A, 6A, 7A only on a common side of the machine frame 3.

Description

The invention relates to a road milling machine which has a machine frame on which a milling drum is arranged. The invention also relates to a method for controlling a road milling machine.

Self-propelled construction machines of various types are used in road construction. These machines include the well-known road milling machines with which existing road layers of the road surface can be removed. The known road milling machines have a rotating milling drum which is equipped with milling tools for machining the road. The milling drum is arranged on the machine frame, the height of which can be adjusted relative to the traffic area to be processed. The height of the machine frame is adjusted using lifting devices that are assigned to the individual crawler tracks or wheels (running gear). The machine frame is lowered to mill off a defective road surface so that the milling drum penetrates the road surface. The lifting devices allow both the height adjustment of the machine frame or the milling drum and the setting of a predetermined inclination of the machine frame or the milling drum transversely to the feed direction of the road milling machine.

For precise setting of the milling depth and inclination, the known road milling machines have a leveling device which has one or more distance measuring devices for measuring the distance between a reference point in relation to the machine frame and the traffic area. The distance measuring devices have one or more distance sensors. Distance measuring devices with several distance sensors (multiplex) arranged offset in the longitudinal direction of the machine frame are used to take into account long-wave unevenness. In the multiplex systems, the distance sensors can be attached to an elongated arm that is attached to one side of the machine frame.

From the DE 10 2006 020 293 A1 A leveling device for a road milling machine is known, which provides on the left and right side of the road milling machine a sensor for detecting the actual value of the milling depth and a sensor for detecting the current cross-slope of the milling drum with respect to the horizontal. The milling depth on the left and right side of the machine can be regulated depending on the deviation of the measured actual values from the target values. The milling depth on each of the two sides can be regulated depending on the actual values of the milling depth on the respective side. The milling depth can also be regulated on one of the two sides depending on the actual values of the milling depth. In this case, the milling depth on the opposite side can be regulated via the cross slope.

The EP 0 547 378 B1 describes a leveling device for a road milling machine, which has three ultrasonic sensors, which are arranged one behind the other in the feed direction of the milling machine. The traffic area is to be scanned with the ultrasound sensors as a reference area. Two distance sensors are located on the machine frame at the height of the drives and a sensor is arranged between the drives. The distance values are evaluated statistically, for example an average is formed in order to generate a control signal for the lifting devices for height adjustment of the drives. Leveling devices are also out of the DE 10 2006 062 129 A1 , EP 2 392 731 A2 or EP 1 154 075 A2 known.

The streets to be worked on can have different profiles. A street can have a roof profile on a straight section of the route. In a right curve, the road surface can be inclined to the right in the direction of travel and in a left curve to the left in relation to the horizontal.

The invention relates to a milling process, also known as copy milling, in which a covering with the same thickness (milling depth) is to be milled off at every point on the road, the inclination of the milled surface of the road (traffic area) with respect to the horizontal not to be changed. For example, if the road surface of the right-hand lane is to be milled off on a street with a roof profile, the If the road milling machine is to drive on the right (right-hand traffic), the milling drum must penetrate the road surface with a predetermined milling depth, whereby the milling drum or the machine frame to which the milling drum is attached must be inclined to the right by a predetermined angle with respect to the horizontal. If the road or road to be milled has a greater width than the milling drum, the road or road must be milled in several sections (tracks). For example, a route section on the outside of the carriageway (1st milling track) and then a section of the route on the inside of the carriageway (2nd milling track) are processed.

At the start of the milling work, the road milling machine is positioned on the road. The lifting devices assigned to the drives are then retracted so that the machine frame is lowered with the milling drum. The machine frame is lowered until the milling tools of the rotating milling drum just touch the road surface. This process is called "scratching". The milling drum should be aligned parallel to the road surface, which determines the alignment of the machine frame.

If a section of road is to be milled outside, the milling depth can be measured on the left side of the milling drum in the working direction. For this purpose, the distance of a reference point related to the machine frame of the road milling machine, which is located on the left side of the milling drum, to the non-milled traffic area is measured. However, a suitable reference surface is not available on the right side of the construction machine in the working direction. Therefore, a distance measurement on the right outer edge of the lane cannot be carried out easily. A guide wire could be laid for a distance measurement on the right-hand side, but this proves to be relatively complex in practice.

In the present case, the milling depth on the right side of the construction machine could also be regulated via the inclination of the machine. Tilting the construction machine to the left increases the milling depth and tilting the machine to the right decreases the milling depth on the right. To be able to control the milling depth on the right-hand side by changing the inclination of the construction machine, the inclination to be set but be known over the entire route. Therefore, additional information (data) about the course of the inclination of the road must be provided, which makes the control of the construction machine relatively complex.

The invention has for its object to provide a road milling machine that enables an exact processing of a traffic area, in particular an exact processing of a traffic area without the provision of additional information about the inclination of the area to be processed. In addition, it is an object of the invention to specify a method which allows an exact processing of a traffic area, in particular without the provision of additional information about the inclination of the area to be processed.

These objects are achieved according to the invention with the features of the independent claims. The subjects of the dependent claims relate to advantageous embodiments of the invention.

The self-propelled road milling machine according to the invention has a machine frame on which a milling drum is arranged, and at least one drive left in the working direction and at least one drive right in the working direction. A total of at least three drives are provided. The road milling machine preferably has a front and a rear, left drive and a front and a rear, right drive. The individual drives are assigned lifting devices from which the machine frame is supported. With the lifting devices, the height and / or inclination of the machine frame or the milling drum in relation to the traffic area (road surface) or the horizontal can be increased or decreased.

In addition, the road milling machine has a leveling device for controlling the lifting devices, which is designed such that the height and / or inclination of the machine frame is adjusted with respect to the traffic area or the horizontal.

The leveling device has a first distance measuring device which is designed such that the distance between at least one reference point and the traffic area is measured, a first distance value being determined, and a second distance measuring device which is designed such that the distance between at least one reference point and the traffic area is measured, a second distance value being determined. In this context, a reference point is understood to be a reference that defines a certain height. A line or plane on which the reference point lies can also be assumed as a reference. If several distance measurements are made for (each) a reference point, a distance value can be determined from the measured values, which is available for further evaluation. For example, the mean value of the measured values can be calculated.

The leveling device has a control and arithmetic unit which is configured such that the distance value determined by the first and second distance measuring devices is compared in each case with a predetermined distance value, and control signals for the lifting devices depending on the deviation of the determined distance value from the predetermined distance value be generated. In this context, control signals are understood to mean the signals or data required for controlling the lifting devices or their associated assemblies, for example hydraulic units. The lifting devices raise and lower or align the mesh frame depending on the control signals.

The control and arithmetic unit of the leveling device can form an independent assembly or at least partially be part of the central control and arithmetic unit of the construction machine. The control and computing unit can, for example, a general processor, a digital signal processor (DSP) for the continuous processing of digital signals, a microprocessor, an application-specific integrated circuit (ASIC), an integrated circuit consisting of logic elements (FPGA) or other integrated circuits (IC) or have hardware components in order to control the lifting devices. A data processing program (software) can run on the hardware components. A combination of the different components is also possible.

The leveling device provides a special control mode which is intended for the operation of the road milling machine in the event that a section of the route is to be machined on the outside of the roadway. This control mode is referred to as leveling mode for a section of road on the outside of the road. The leveling device can also provide other control modes which are intended for other operating cases.

The first and second distance measuring devices are designed for the leveling mode for a section of road on the outside of the roadway in such a way that their reference points in the working direction lie only on a common side of the milling drum, the reference point of the second distance measuring device being at a predetermined lateral distance from the reference point of the first distance measuring device the side of the reference point of the first distance measuring device facing away from the milling drum. The first measurement can be made close to the milling drum.

The control and arithmetic unit is configured such that the control and arithmetic unit, as a function of the deviation of the first distance value determined by the first distance measuring device from the predetermined distance value, control signals for the lifting device which is assigned to the drive and which is the reference point of the first distance measuring device facing, generated, and generates, depending on the deviation of the second distance value determined by the second distance measuring device from the predetermined distance value, control signals for the lifting device, which is assigned to the drive which is facing away from the reference point of the first distance measuring device.

If two drives are provided on the left or right side, control signals can be generated for the lifting device assigned to the front and / or rear drives.

The common side on which the two reference points lie depends on whether the road milling machine moves in the working direction on the right side (right-hand traffic) or on the left side (left-hand traffic).

A particularly preferred embodiment of the road milling machine is particularly suitable for right-hand traffic. This embodiment is referred to below.

The first and second distance measuring devices for leveling mode for a section of road on the outside of the lane are designed for right-hand traffic in such a way that their reference points in the working direction lie on the left side of the milling drum, the reference point of the second distance measuring device being at a predetermined lateral distance from the reference point of the first Distance measuring device is on the left side of the reference point of the first distance measuring device. The first measurement can be made on the left side of the machine, close to the milling drum.

The control and arithmetic unit intended for right-hand traffic is configured such that the control and arithmetic unit generates control signals for the lifting device assigned to the drive on the left in the working direction depending on the deviation of the first distance value determined by the first distance measuring device from the predetermined distance value Depending on the deviation of the second distance value determined by the second distance measuring device from the predetermined distance value, control signals are generated for the lifting device assigned to the right-hand drive in the working direction.

For the machining of a section of road on the inside of the roadway, the first distance measuring device is designed such that its reference point lies on the left side of the milling drum in the working direction, and the second distance measuring device is designed such that its reference point lies on the right side of the milling drum in the working direction. The reference point of the second distance measuring device is thus at a predetermined lateral distance from the reference point of the first distance measuring device on the right side of the reference point of the first distance measuring device. The two measurements can be placed close to each Milling drum done. This leveling mode is part of the state of the art.

To raise and lower the machine frame and / or to adjust the inclination of the machine frame, the control and computing unit can be configured such that the lifting devices are retracted or extended. Consequently, the deviation of the first or second distance value determined by the first or second distance measuring device from the predetermined distance value can be minimized.

For the leveling mode in a section of road on the outside of the roadway, the control and arithmetic unit can be configured such that the lifting device assigned to the drive on the left in the working direction is retracted if the first distance value determined by the first distance measuring device is greater than the predetermined distance value, and that the lifting device assigned to the left drive in the working direction is extended when the first distance value determined by the first distance measuring device is smaller than the predetermined distance value, and the lifting device assigned to the right driving direction in the working direction is extended when the second distance value determined by the second distance measuring device is greater than the predetermined distance Distance value is, and the lifting device assigned to the drive on the right in the working direction is retracted when the second distance value determined by the second distance measuring device is smaller than the predetermined distance is worth.

For the leveling mode in a section of the route on the inside of the road, the control and computing unit can be configured such that the lifting device assigned to the drive on the left in the working direction is retracted if the first distance value determined by the first distance measuring device is greater than the predetermined distance value, and that the lifting device assigned in the left drive direction in the working direction is extended when the first distance value determined by the first distance measuring device is smaller than the predetermined distance value, and the lifting device assigned in the working direction right drive is retracted when the second distance value determined by the second distance measuring device is greater than the predetermined one Distance value, and the drive in the right direction assigned lifting device is extended when the second distance value determined by the second distance measuring device is smaller than the predetermined distance value.

In a road milling machine that is intended for left-hand traffic, the situation is reversed in an analogous manner.

For each of the two leveling modes, only two distance measurements offset to one another are required. Therefore, basically only two distance measuring devices are required. The distance measuring devices can have interchangeable scanning sensors on the road milling machine, which can be attached to suitable holders. If interchangeable distance sensors are provided, the road milling machine can be converted for one or the other leveling mode, in which one of the two distance sensors is mounted on the same side as the other distance sensor or on the other side. However, the road milling machine can also be equipped with three permanently mounted distance sensors, in which case only two distance sensors are active at any time and, depending on the leveling mode, it is switched back and forth between the distance sensors.

The control and computing unit of the leveling device can basically use the same computing algorithms for the two leveling modes. The same hardware components and assemblies can also be used for the control. The difference in the evaluation of the measured values essentially lies only in the fact that when the measurement is shifted from one side of the road milling machine to the other side, for example from the right side to the left side, in particular in the area of the center of the lane, there is an opposite movement of the associated lifting device (s). For example, the lifting device assigned to the drive on the right in the working direction is not retracted, but rather extended when the second distance value determined by the second distance measuring device is greater than the predetermined distance value.

A preferred embodiment provides that the lateral distance of the Reference point of the second distance measuring device to the reference point of the first distance measuring device in the leveling mode for a route section on the outside of the road surface essentially corresponds to the lateral distance of the reference point of the second distance measuring device to the reference point of the first distance measuring device in the leveling mode for a route section on the inside of the roadway.

The lateral distance of the reference point of the second distance measuring device to the reference point of the first distance measuring device can largely correspond to the width of the machine frame of the road milling machine or the distance between the drives (track width) or the width of the milling drum. The lateral distance can also be larger or smaller. Choosing the same distance for both operating modes has the advantage that, with the same control deviation, the lifting device is moved by the same amount in both operating modes, the movement being only in opposite directions. Consequently, for the different configuration of the control and arithmetic unit for both leveling modes, when evaluating the measured values, only consideration of a "sign reversal" is required, so that only a relatively small programming effort is required for the implementation of the system on the road milling machines according to the prior art .

If the lateral distance of the reference point of the second distance measuring device to the reference point of the first distance measuring device is different in both operating modes, for example if the conditions on the construction site should make this necessary, a conversion factor must be taken into account in addition to the "sign reversal", which is the ratio between the distance in one mode and the distance in the other mode. For example, the control signals for the piston / cylinder devices of the lifting devices can be offset with a factor. If the distance in the operating mode according to the invention, in which both distance sensors are on one side of the machine frame, corresponds to half the distance of the two distance sensors in the operating mode in which both distance sensors are on different sides of the machine frame, this results in a conversion factor of 2 for the operating mode according to the invention, which corresponds to the ratio of the distances.

The first and / or second distance measuring device can each have one or more distance sensors. For the leveling mode for the outside of the road, only an additional distance sensor needs to be provided or an existing distance sensor has to be installed on the other side of the machine.

The distance sensor can be, for example, any tactile or non-contact distance sensor. The edge protection provided on the end faces of the milling drum in the known road milling machines and standing on the ground can also act as a scanning element of a tactile distance sensor. Optical or inductive or capacitive distance sensors or ultrasonic distance sensors can be used as contactless distance sensors. The distance measurement can be a point measurement. In practice, however, the known distance sensors provide for the measurement in relation to an area, for example a circular area in the case of an ultrasonic sensor or the contact area of an edge protector. To take unevenness into account, the first and / or second distance measuring device can have a number of distance sensors arranged in the longitudinal direction of the road milling machine (multiplex), the distance measuring device being designed such that the distance value is determined from the distances measured by the distance sensors. The distance value can be, for example, the mean value from the measured distances.

An embodiment of the method according to the invention provides that the reference points (R1, R2) lie in the working direction (A) on the right side of the milling drum (10), the reference point (R2) of the second distance measurement (17) being at a lateral distance (c ) to the reference point (R1) of the first distance measurement (16) is on the right side of the reference point (R1) of the first distance measurement (16), and depending on the deviation of the first distance value from the predetermined distance value that in the working direction (A) right drive (5, 7) associated lifting device (5A, 7A) is controlled, and depending on the deviation of the second distance value from the predetermined distance value which is controlled by the lifting device (4A, 6A) assigned to the left drive (A) in the working direction (A).

A further embodiment of the method according to the invention provides that the lifting device (5A, 7A) assigned to the right drive (A) in the working direction (A) is retracted when the first distance value is greater than the predetermined distance value and that in the working direction the lifting device (5A, 7A) assigned to the right drive (5, 7) is extended when the first distance value is smaller than the specified distance value, and the lifting device (4A, 6A) assigned to the drive (4, 6) on the left in the working direction (A) is extended when the second distance value is greater than the predetermined distance value, and the lifting device (4A, 6A) associated with the drive (4, 6) on the left in the working direction (A) is retracted when the second distance value is less than the predetermined distance value.

A further embodiment of the method according to the invention provides that when the construction machine moves in a section of track on the inside of the roadway (20B), the lifting device (4A, 6A) assigned to the drive (4, 6) on the left in the working direction (A) is retracted when the the first distance value is greater than the predetermined distance value, and the lifting device (4A, 6A) assigned to the drive (4, 6) on the left in the working direction is extended when the first distance value is less than the predetermined distance value and that in the working direction (A) the lifting device (5A, 7A) assigned to the right drive is retracted when the second distance value is greater than the predetermined distance value, and the lifting device (5A, 7A) assigned to the drive in the right direction (A) is extended when the second distance value is smaller than that specified distance value.

A further embodiment of the method according to the invention provides that the lifting devices (4A, 5A, 6A, 7A) are retracted or extended so that the deviation of the first distance value determined by the first distance measurement (16) or that of the second distance measurement (17) determined second distance value is minimized from the predetermined distance value.

A further embodiment of the method according to the invention provides that the lateral distance (c) of the reference point (R2) of the second distance measurement to the reference point (R1) of the first distance measurement in the leveling mode for a section of road on the outside of the roadway (20A) is the lateral distance of the reference point (R2 ') of the second distance measurement to the reference point (R1) corresponds to the first distance measurement in the leveling mode for a section of the route on the inside of the roadway (20A).

A further embodiment of the method according to the invention provides that the distance measurement is a tactile or non-contact distance measurement.

A further embodiment of the method according to the invention provides that the distance to the traffic area (8) is measured at a number of reference points arranged offset in the longitudinal direction of the road milling machine.

An exemplary embodiment of the invention is described in detail below with reference to the drawings.

Fig. 1

eine Straßenfräsmaschine in der Seitenansicht,

Fig. 2

die Nivelliereinrichtung der Straßenfräsmaschine in einer stark vereinfachten schematischen Darstellung,

Fig. 3

eine Draufsicht auf eine Fahrbahn, die von der Straßenfräsmaschine bearbeitet wird, wobei die Straßenfräsmaschine einen fahrbahnaußenseitigen Streckenabschnitt bearbeitet,

Fig. 4

eine Draufsicht auf eine Fahrbahn, die von der Straßenfräsmaschine bearbeitet wird, wobei die Straßenfräsmaschine einen fahrbahninnseitigen Streckenabschnitt bearbeitet und

Fig. 5

die den fahrbahnaußenseitigen Streckenabschnitt bearbeitende Straßenfräsmaschine in vereinfachter schematischer Darstellung.

Show it:

Fig. 1

a side milling machine in side view,

Fig. 2

the leveling device of the road milling machine in a highly simplified schematic representation,

Fig. 3

2 shows a plan view of a roadway that is being processed by the road milling machine, the road milling machine processing a route section on the outside of the roadway,

Fig. 4

a plan view of a roadway that is processed by the road milling machine, wherein the road milling machine a route section inside the roadway edited and

Fig. 5

the road milling machine processing the outside of the road section in a simplified schematic representation.

Fig. 1 shows a side view of a self-driving road milling machine 1 for milling road surfaces. The road milling machine 1 has a chassis 2 and a machine frame 3. The chassis 1 has a front left drive 4 in the working direction A and a front right drive 5 as well as a rear left drive 6 and a rear right drive 7. Chain drives or wheels can be provided as drives.

In order to adjust the height and / or inclination of the machine frame 3 relative to the surface of the ground (traffic area), the road milling machine has lifting devices 4A, 5A, 6A, 7A assigned to the individual drives 4, 5A, 6A, 7A, by which the machine frame 3 is supported . The lifting devices 4A, 5A, 6A, 7A each have a piston / cylinder arrangement 9.

The road milling machine 1 also has a milling drum 10 equipped with milling tools, which is arranged on the machine frame 3 between the front and rear drives 4, 5, 6, 7 in a milling drum housing 11 which is provided on the longitudinal sides with left and right edge guards 12, 13 is closed.

By retracting and extending the piston / cylinder arrangements 9 of the lifting devices 4A, 5A, 6A, 7A, the height and / or inclination of the machine frame 3 and the milling drum 10 arranged on the machine frame relative to the traffic area 8 can be adjusted.

A conveyor device 14 with a conveyor belt is provided for the removal of the milled off road surface.

The road milling machine according to the invention has a leveling device 15 for actuating the lifting devices 4A, 5A, 6A, 7A, which in FIG Fig. 1 is only hinted at. Fig. 2 shows a highly simplified schematic representation of the leveling device. The leveling device 15 is described below.

The leveling device 15 has a first distance measuring device 16 and a second distance measuring device 17, each of which has a distance sensor 16A, 17A in the present exemplary embodiment. Instead of distance measuring devices with only one sensor, it is also possible to use distance measuring devices with several distance sensors arranged in a row, which belong to the prior art. A further description of these distance measuring systems is therefore omitted.

The leveling device 15 described below is intended for a road milling machine that is particularly suitable for right-hand traffic.

The first distance measuring device 16 has a distance sensor 16A, which is arranged on the left side of the machine frame 3 in the working direction A between the front and rear drives 4, 5, 6, 7, preferably laterally next to the milling drum 10 ( Fig. 5 ). In the present exemplary embodiment, this distance sensor 16A is a tactile distance sensor which makes use of the left edge protection 12, to which a cable pull sensor 12A is attached. If the edge protection is fastened in a height-adjustable manner by means of two hydraulic cylinders arranged offset in the direction of travel, the height of the edge protection can also be detected by means of a position measuring system integrated in the hydraulic cylinder instead of by means of a cable pull sensor. The edge protection 12 rests on the traffic area 8. The cable pull sensor 12A measures the distance by which the edge protector 12 moves up and down. Consequently, the distance a between a first reference point R1 relating to the road milling machine and the traffic area 8 on which the edge protector 12 rests can be measured.

In the present exemplary embodiment, the second distance measuring device 17 has an optical distance sensor 17A, which is located on the left-hand side of the Machine frame 3 between the front and rear drives 4, 5, 6, 7 is preferably arranged at the level of the milling drum 10. The reference points R1 and R2 of the first and second distance sensors 16, 17 preferably lie in a vertical plane which is cut essentially orthogonally by the longitudinal axis of the machine frame and in which the axis of the milling drum preferably also lies essentially. The reference point R2 of the second distance sensor 17A lies at a predetermined lateral distance c from the reference point R1 of the first distance sensor 16A on the left in the working direction A of the reference point R1 of the first distance sensor 16A. The second distance sensor 17A is fastened to a holder 19, for example to a laterally projecting linkage, which in turn is attached to the machine frame 3.

The measurement on the inside of the carriageway 20B is preferably carried out in the area of the carriageway center 20C, particularly preferably on the carriageway center 20C, since the carriageway 20 has the least damage there. As a result, a measurement is not made on the hard shoulder 20D of the road 20 (banquets). In the present exemplary embodiment, the carriageway 20 is approximately twice as wide as the width of the milling drum 10 (milling track). The predetermined distance c between the two distance sensors 16A, 17A should therefore correspond to approximately half the width of the roadway or the width of the road milling machine or the width of the milling drum or the distance of the drives (track width). In an analogous view, other distances result from the respective roadway width or the width of the milling track.

In addition, the leveling device 15 has a control and computing unit 21, which is configured such that the following steps are carried out.

In the leveling mode for a section of road on the outside of the road 20A, the control and computing unit 21 activates the first and second distance measuring devices 16, 17. The first distance sensor 16A measures the distance a and the second distance sensor 17A measures the distance b. If a plurality of distances a ₁ , a ₂ , a ₃ or b ₁ , b ₂ , b ₃ are measured with a plurality of distance sensors, the control and computing unit 21 of the leveling device 15 calculates as the distance value a _is or b _is, for example, the mean value the distances a ₁ , a ₂ , a ₃ and b ₁ , b ₂ , b ₃ . After adjusting the distance measuring device, the milling depth can be determined from the distance values, which is described in more detail below.

At the start of the milling work, the leveling device 15 is adjusted, in particular the zero point is set. In order to set the zero point, the lifting devices 4, 5, 6, 7 are set such that the milling drum 10 touches the traffic area 8 with the cylindrical lateral surface described by the tips of the milling tools. For this purpose, the lifting devices 4A, 5A, 6A, 7A are retracted until the milling tools of the rotating milling drum 10 begin to scratch the floor. This process is also known as scratching. When the milling cutters touch the traffic area 8, the distance measuring devices 16, 17 are set to zero. If the lifting devices 4A, 5A, 6A, 7A are retracted further and the milling drum 10 penetrates into the ground, negative distance values are determined. The distance values correspond to the milling depth. The determined distance values can be used as positive values, e.g. B. milling depth 5 cm.

The determined distance values a _ist and b _ist are compared in each case with predetermined distance values a _soll and b _soll .

The Figures 3 and 5 show the case that the road milling machine 1 is to machine the right section on the outside of the road 20A, this section being inclined in the direction of the outside of the road. When aligning, the road milling machine 1 therefore assumes an inclination with respect to the horizontal. The set milling depth corresponds to the thickness of the surface to be removed from the road surface.

During the advancement of the road milling machine 1, the determined distance values a _ist and b _ist , which correspond to the actual milling depth, are compared with the predetermined distance values a _soll and b _soll , which correspond to the desired milling depth (Δa = a _ist - a _soll or Δb = b _is - b _should ). Depending on the deviation of the actual distance value from the target distance value of the first distance sensor 16A (Δa = a _ist - a _soll ) control signals are generated for the lifting device (s) 4A, 6A, which are assigned to the front and / or rear drives 4, 6 in the working direction, and as a function of the deviation of the actual distance value from the target distance value of the second distance sensor 17 (Δb = b _ist - b _should ) control signals are generated for the lifting device (s) 5A, 7A, which are assigned to the front and / or rear right hand drives 5, 7 in the working direction. The control signals are received by the lifting devices 4A, 5A, 6A, 7A and the lifting devices are moved in such a way that the difference between the actual values and the target values is minimal.

The lifting devices 4A, 6A assigned to the front and / or rear, left hand drives 4, 6 in the working direction A are retracted when the first distance value a determined by the first distance measuring device 16 _is greater than the predetermined distance value a _should , and that in the working direction A lifting devices 4A, 6A assigned to front and / or rear, left drives 4, 6 are extended when the first distance value a determined by the first distance measuring device 16 _is smaller than the predetermined distance value a _should . Analogously, the lifting devices 5A, 7A assigned to the front and / or rear right hand drives 5, 7 in the working direction A are extended when the second distance value b determined by the second distance measuring device 17 _is greater than the predetermined distance value b _should , and the The lifting devices 5A, 7A assigned to the front and / or rear, right hand drives 5, 7 in the working direction A are retracted when the second distance value b determined by the second distance measuring device 17 _is smaller than the predetermined distance value b _should .

The front and rear lifting devices 4A, 5A, 6A, 7A can each be retracted or extended by the same amount if the distance sensors are at the level of the longitudinal axis 18 in the middle between the front and rear drives 4, 5, 6, 7 arranged milling drum 9 lie.

With the regulation described above, the desired milling depth is maintained across the width of the machined road section. Since the roadway 20 is wider than the milling track, in the present exemplary embodiment it is approximately twice as wide as the milling track, section 20B on the inside of the road still has to be machined. The leveling device 15 provides a different leveling mode for processing this section. This leveling mode corresponds to the known leveling, in which a distance measurement is carried out on the end faces of the milling drum 10 on both sides of the road milling machine. Consequently, use can be made of the first distance measuring device 16 which is designed such that its reference point R1 lies in the working direction A on the left side of the milling drum 10. The leveling device 15 again generates the control signals for the lifting devices 4A, 6A of the front and / or rear left drives 4, 6. However, the leveling device 15 in the present embodiment cannot make use of the second distance measuring device 17. This distance measuring device 17 can therefore be deactivated or need not be present (installed).

The control signals for the front and / or rear, left and right lifting devices 4, 5, 6, 7 are now generated by a leveling device 15, which will be described below. Since the leveling mode again provides two distance measuring devices 16, 17 for the inside of the road, these distance measuring devices are again referred to as first and second distance measuring devices 16, 17. The leveling device 15 for the inside of the carriageway 20B can be provided by the leveling device for the outside of the carriageway 20A described above, if the distance sensor 17A of the second distance measuring device 17 on the right in the working direction A of the machine frame 3 at a predetermined distance c from the distance sensor 16A first distance measuring device 16 is arranged.

The distance sensors 16A, 17A can be designed as interchangeable units that can be attached to suitable holders, so that the road milling machine can be equipped with suitable distance sensors for the respective leveling mode. However, it is also possible to provide three distance measuring devices or at least three distance sensors on the road milling machine 1, of which only two distance measuring devices or distance sensors are activated for the respective leveling mode.

In the present exemplary embodiment, the distance measurement is carried out on the right machine side with an optical distance sensor 17A '( Figures 4 and 5 ). The distance measurement on the right side of the machine can also be done with the right edge protection and a cable pull sensor, which is already available on the left and right side in the known road milling machines.

The control and arithmetic unit 21 is configured for the leveling mode in the left-hand section of the road on the inside 20B in such a way that the lifting devices 4A, 6A of the front and / or rear, left-hand drives 4, 6 are retracted when that of the first distance measuring device 16 The first distance value determined is greater than the predetermined distance value, and the lifting devices 4A, 6A of the front and / or rear left drive 4, 6 are extended when the first distance value determined by the first distance measuring device 16 is smaller than the predetermined distance value. In an analogous manner, the lifting devices 5A, 7A of the front and / or rear right-hand drives 5, 7 are retracted if the second distance value determined by the second distance measuring device 17 'is greater than the predetermined distance value, and the lifting devices 5A, 7A of the front and / or the rear, right drives 5, 7 are extended when the second distance value determined by the second distance measuring device 17 'is smaller than the predetermined distance value. With this regulation, the inside of the road 20A can be processed.

Claims (15)

Road milling machine with
a machine frame (3) on which a milling drum (10) is arranged,
at least one drive (4, 6) on the left in the working direction (A) and at least one drive (5, 7) on the right in the working direction,
the lifting devices (4A, 5A, 6A, 7A) assigned to the drives (4, 5, 6, 7) and from which the machine frame (3) is supported,
a leveling device (15) for controlling the lifting devices (4A, 5A, 6A, 7A), which is designed in such a way that the height and / or inclination of the machine frame (3) with respect to the traffic area (8) can be adjusted,
the leveling device (15) having: a first distance measuring device (16) which is designed such that the distance (a) between at least one reference point (R1) and the traffic area (8) is measured, a first distance value being determined, and a second distance measuring device (17) which is designed such that the distance (b) between at least one reference point (R2) and the traffic area (8) is measured, a second distance value being determined, and a control and arithmetic unit (21) which is configured such that the distance value determined by the first and second distance measuring device (16, 17) is compared in each case with a predetermined distance value, and as a function of the deviation of the determined distance value from the predetermined distance value Control signals for the lifting devices (4, 5, 6, 7) are generated, characterized in that the leveling device (15) provides a leveling mode for a section of road on the outside of the roadway (20A), wherein the first and second distance measuring devices (16, 17) are designed such that their reference points (R1, R2) lie in the working direction (A) on a common side of the milling drum (10), the reference point (R2) of the second distance measuring device (17) at a lateral distance (c) from the reference point (R1) of the first distance measuring device (16) on the side of the reference point (R1) of the first distance measuring device (16) facing away from the milling drum (10), and the control and computing unit (21) is configured such that the control and computing unit as a function of the deviation of the first distance value determined by the first distance measuring device (16) from the predetermined distance value, control signals for the lifting device (4A, 6A), which the Drive (4, 6) is assigned, which faces the reference point (R1) of the first distance measuring device (16), and, depending on the deviation of the second distance value (17) determined by the second distance measuring device (17) from the predetermined distance value, control signals for the Lifting device (5A, 7A), which is assigned to the drive (5, 7) that faces away from the reference point (R1) of the first distance measuring device (16). Road milling machine according to claim 1, characterized in that the leveling device (15) provides a leveling mode for a route section on the inside of the roadway (20B), wherein
the first distance measuring device (16) is designed such that its reference point (R1) lies in the working direction (A) on the left side of the milling drum (10), and the second distance measuring device (17 ') is designed such that its reference point (R2' ) in the working direction (A) on the right side of the milling drum (10) the reference point (R2 ') of the second distance measuring device (17') at a lateral distance (c) from the reference point (R1) of the first distance measuring device (16) on the right side of the reference point (R1) of the first distance measuring device (16) lies. Road milling machine according to claim 1, characterized in that
the first and second distance measuring devices (16, 17) are designed such that their reference points (R1, R2) lie in the working direction (A) on the left side of the milling drum (10), the reference point (R2) of the second distance measuring device (17) at a lateral distance (c) from the reference point (R1) of the first distance measuring device (16) on the left side of the reference point (R1) of the first distance measuring device (16), and
the control and arithmetic unit (21) for the leveling mode is configured in a route section on the outside of the road (20A) such that the control and arithmetic unit is dependent on the deviation of the first distance value determined by the first distance measuring device (16) from the predetermined distance value Control signals for the lifting device (4, 6) assigned to the left drive (A) in the working direction (A) are generated, and, depending on the deviation of the second distance value determined by the second distance measuring device (17) from the predetermined distance value, control signals for the in the working direction (A) right drive (5, 7) associated lifting device (5A, 7A) generated. Road milling machine according to claim 3, characterized in that the control and arithmetic unit (21) for the leveling mode is configured in a section of the route on the outside of the roadway (20A) in such a way that the lifting device assigned to the drive (4, 6) on the left in the working direction (A) (4, A 6A) is retracted when the first distance value determined by the first distance measuring device (16) is greater than the predetermined distance value, and the lifting device (4A, 6A) assigned to the drive (4, 6) on the left in the working direction (A) is extended when the the first distance value determined by the first distance measuring device (16) is smaller than the predetermined distance value, and the lifting device (5A, 7A) assigned to the drive (5, 7) on the right in the working direction (A) is extended when the one by the second distance measuring device (17 ) the second distance value determined is greater than the predetermined distance value, and the lifting device (5A, 7A) assigned to the drive on the right in the working direction (A) is retracted if the second distance value determined by the second distance measuring device (17) is smaller than the predetermined distance value. Road milling machine according to claim 1, characterized in that the first and second distance measuring devices (16, 17) are designed such that their reference points (R1, R2) lie in the working direction (A) on the right side of the milling drum (10), the reference point (R2) of the second distance measuring device (17) lies at a lateral distance (c) from the reference point (R1) of the first distance measuring device (16) on the right side of the reference point (R1) of the first distance measuring device (16), and
the control and arithmetic unit (21) for the leveling mode is configured in a route section on the outside of the road (20A) such that the control and arithmetic unit is dependent on the deviation of the first distance value determined by the first distance measuring device (16) from the predetermined distance value Control signals for the lifting device (5, 7A) assigned to the drive (5, 7) on the right in the working direction (A) are generated, and, depending on the deviation of the second distance value determined by the second distance measuring device (17) from the predetermined distance value, control signals for the lifting device (4A, 6A) assigned to the left drive (4, 6) in the working direction (A). Road milling machine according to claim 5, characterized in that the control and arithmetic unit (21) for the leveling mode is configured in a section of the route on the outside of the roadway (20A) in such a way that the lifting device assigned to the drive (5, 7) on the right in the working direction (A) (5A, 7A) is retracted when the first distance value determined by the first distance measuring device (16) is greater than the predetermined distance value, and the lifting device (5A, 7A) assigned to the right-hand drive (A) in the working direction (A) is extended when the one from the first distance value (16) determined by the first distance measuring device (16) is smaller than the predetermined distance value, and the lifting device (4A, 6A) assigned to the left drive (A) in the working direction (A) is extended when the lifting device (4A, 6A) assigned by the second distance measuring device (17) The second distance value determined is greater than the predetermined distance value, and the lifting device (4A, 6A) assigned to the drive on the left in the working direction (A) is retracted if the second distance value determined by the second distance measuring device (17) is smaller than the predetermined distance value. Road milling machine according to claim 2, characterized in that the control and arithmetic unit (21) for the leveling mode is configured in a route section on the inside of the roadway (20B) such that
the lifting device (4A, 6A) assigned to the left drive (A) in the working direction (A) is retracted when the first distance value determined by the first distance measuring device (16) is greater than the predetermined distance value, and the lifting device (A ) the left drive (4, 6) associated lifting device (4A, 6A) is extended when the first distance value determined by the first distance measuring device (16) is smaller than the predetermined distance value, and
the lifting device (5A, 7A) assigned to the right-hand drive (A) in the working direction (A) is retracted when the second distance value determined by the second distance-measuring device (17 ') is greater than the predetermined distance value, and the right-hand one in the working direction Drive (5, 7) assigned to the lifting device (5A, 7A) is extended when the second distance value determined by the second distance measuring device (17 ') is smaller than the predetermined distance value. Road milling machine according to one of claims 1 to 7, characterized in that the control and computing unit (21) is configured such that the lifting devices (4A, 5A, 6A, 7A) are retracted or extended so that the deviation of the first distance value determined by the first distance measuring device (16) or of the second distance value determined by the second distance measuring device (17) from the predetermined distance value is minimized. Road milling machine according to one of claims 1 to 8, characterized in that the lateral distance (c) of the reference point (R2) of the second distance measuring device (17) to the reference point (R1) of the first distance measuring device (16) in the leveling mode for a section of the road The outside of the roadway (20B) corresponds to the lateral distance (c) of the reference point (R2 ') of the second distance measuring device (17') to the reference point (R1) of the first distance measuring device (16) in the leveling mode for a section of the route on the inside of the roadway (20A). Road milling machine according to one of claims 1 to 9, characterized in that the first and / or second distance measuring device 16, 17) have at least one distance sensor (16A, 17A), which is a tactile distance sensor or a non-contact distance sensor. Road milling machine according to one of claims 1 to 10, characterized in that the first and / or second distance measuring device (16, 17) have a number of distance sensors arranged offset in the longitudinal direction of the road milling machine, the first and / or the second distance measuring device (16, 17 ) is designed such that the distance value is determined from the distances measured by the distance sensors. Method of controlling a road milling machine comprising: a machine frame (3) on which a milling drum (10) is arranged, at least one drive (4, 6) on the left in the working direction and at least one drive (5, 7) on the right in the working direction, the drives (4, 5, 6, 7) associated lifting devices (4A, 5A, 6A, 7A), by which the machine frame (3) is supported, wherein the distance (a) between at least a first reference point (R1) and the traffic area (8) is measured with a first distance measurement, a first distance value being determined, and with a second distance measurement the distance (b) between at least one second reference point (R2 ) and the traffic area (8) is measured, with a second distance value being determined, and the first and second distance values being compared in each case with a predetermined distance value, and depending on the deviation of the determined distance value from the predetermined distance value, the lifting devices (4A, 5A , 6A, 7A) can be controlled, characterized in that In a leveling mode for a section of road on the outside of the roadway (20A), the reference points (R1, R2) of the first and second distance measurements in the working direction (A) lie on a common side of the milling drum (10), the reference point (R2) of the second distance measurement ( 17) at a lateral distance (c) from the reference point (R1) of the first distance measurement (16) on the side of the reference point (R1) of the first distance measurement (16) facing away from the milling drum (10), and
depending on the deviation of the first distance value from the predetermined distance value, the lifting device (4A, 6A), which is assigned to the drive (4, 6), which faces the reference point (R1) of the first distance measurement (16), and depending on the deviation of the second distance value from the predetermined distance value, the lifting device (5A, 7A), which is assigned to the drive (5, 7), which faces away from the reference point (R1) of the first distance measurement (16). A method according to claim 12, characterized in that the leveling device provides a leveling mode for a route section on the inside of the roadway (20B), wherein
the reference point (R1) of the first distance measurement (16) in the working direction (A) is on the left side of the milling drum (10), and the reference point (R2 ') of the second distance measurement (17) in the working direction is on the right side of the milling drum (10 ), whereby the reference point (R2 ') of the second distance measurement lies at a predetermined lateral distance (c) from the reference point (R1) of the first distance measurement on the right side of the reference point (R1) of the first distance measurement. A method according to claim 12, characterized in that the reference points (R1, R2) of the first and second distance measurement in the working direction (A) are on the left side of the milling drum (10), the reference point (R2) of the second distance measurement (17) in a lateral distance (c) to the reference point (R1) of the first distance measurement (16) lies on the left side of the reference point (R1) of the first distance measurement (16), and
as a function of the deviation of the first distance value from the specified distance value, the lifting device (4A, 6A) assigned to the drive (A) on the left in the working direction (A) is actuated, and as a function of the deviation of the second distance value from the specified distance value the lifting device (5A, 7A) assigned to the drive (5, 7) on the right in the working direction (A). A method according to claim 14, characterized in that when the construction machine moves in a section on the outside of the roadway (20B), the lifting device (4A, 6A) assigned to the drive (4), which is on the left in the working direction (A), is retracted when the first one Distance value is greater than the predetermined distance value, and the lifting device (4A, 6A) assigned to the drive on the left in the working direction is extended when the first distance value is smaller than the predetermined distance value, and that of the drive (5, 7) on the right in working direction (A) ) assigned lifting device (5A, 7A) is extended when the second distance value is greater than the predetermined distance value, and the lifting device (5A, 7A) assigned to the drive (5, 7) on the right in the working direction (A) is retracted when the second distance value is less than the predetermined distance value.

Images