FLOOR TILLING MACHINE AND METHOD FOR OPERATING A DUST EXTRACTION DEVICE OF A FLOOR TILLING MACHINE

Description

[0001] The invention relates to a soil milling machine, in particular a road milling machine, a recycler or a stabilizer, for processing soil in or against a working direction. Furthermore, the invention also relates to a method for operating a dust extraction device of a soil milling machine.

[0002] Soil milling machines of this type are used in road and path construction and are described, for example, in EP3225738B1. They have a machine frame supported by drive mechanisms and a drive motor that typically provides the power required for travel and operation. The drive mechanisms can be, for example, tracks or wheels. The drive motor can be, for example, an internal combustion engine, such as a diesel engine. Such machines are preferably self-propelled and move under their own power across the ground to be worked. The central working unit of soil milling machines of this type is a milling drum, rotatably mounted in a milling drum housing attached to the machine frame, for removing soil material.The milling drum can have a hollow cylindrical body on whose outer surface a multitude of milling tools, such as milling chisels, are mounted radially projecting from the outer surface. During operation, the milling drum rotates around an axis of rotation, which is usually horizontal and perpendicular to the working direction of the soil milling machine. The milling tools are driven into the subsoil to be removed by lowering and moving the soil milling machine in a travel or working direction, thus milling it to a specified depth. The milling drum housing surrounds the milling drum like a hood and is open towards the bottom, allowing the milling drum to project downwards beyond the lower edge of the housing for soil penetration.The milling drum housing can include height-adjustable wall elements relative to the milling drum, such as a scraper plate, one or more side plates, and / or a front plate. These elements allow the lower sealing edge of the milling drum housing to be adapted to various milling conditions, particularly regarding milling depth and / or soil conditions. The milled material collected in the milling drum housing is typically transported from there through a discharge opening in the housing to a material conveying system. From there, the material conveying system directs the material to a discharge point. This is also referred to below as the material conveying path. The material conveying system can comprise one or more conveyor belts arranged in series. At the discharge point, the material conveying system discharges the soil material onto the loading platform of a transport vehicle, such as a truck, for further removal.

[0003] Milling and conveying or transporting soil material can generate significant dust during operation of the soil milling machine. The resulting dust can impair the vision and / or health of people on or near the machine. Air in which this dust is dispersed is referred to below as dusty air. To minimize the release of dust into the surrounding environment, it is already known to equip soil milling machines of this type with a dust extraction system.Depending on the design, the purpose of this dust extraction system is to control dust emissions, particularly in the area of ​​the milling drum housing and / or in the area of ​​the milled material conveying system, and either to direct the dust to specific points on the milling machine, for example, to a milled material discharge point of the conveying system leading to a transport vehicle, and / or to capture the resulting dust in order to reduce the overall dust emissions of the milling machine. Of particular relevance here are inert dust (E-dust) and respirable dust (A-dust), as defined in DIN EN 481. The dust extraction system typically comprises at least one extraction fan and an extraction duct connected to the extraction fan in a flow-connected manner. The extraction fan, which has a suction side and an exhaust side, thus creates a negative pressure on the suction side and ultimately an air suction in the extraction duct.The extraction duct, in turn, refers to an air-permeable connection between the interior of the milling drum housing and / or a section of the material conveying system and the extraction fan. The extraction duct can be designed as a conduit / channel that is at least partially separate from the material conveying system, but it can also share a common space with the material conveying system, at least partially. Therefore, the milled material and the extraction duct, or the dust-laden air conveyed in the extraction duct, do not necessarily have to be completely spatially separated, but can, at least partially, also pass through the same spatial compartment.Particularly because the material conveying system in soil milling machines of this type is often enclosed by a housing perpendicular to the conveying direction of the material, thus forming a channel-like structure, it is possible that at least parts or sections of the material conveying system are also part of the extraction duct. Crucially, the design of the extraction duct must ensure that the suction generated by the extraction fan can ultimately act as far as, ideally, the milling drum housing, especially its interior, and / or a portion of the material conveying path of the material conveying system. This allows dust-laden air to be extracted from the interior of the milling drum housing and / or the conveying path of the material conveying system and transported via the extraction duct to the extraction fan and downstream to an outlet point.Upstream and / or downstream of the extraction fan, the extracted dust-laden air can further be passed through a dust reduction device or dust separation device, for example, a filter device such as an electrostatic and / or fabric and / or cyclone filter, and / or a water spray device. Soil milling machines with dust extraction devices are disclosed, for example, in EP 0 971 075 A1, CN 108 797 291 A, and EP 3 225 738 B1. A generic soil milling machine with a dust extraction device is described, for example, in German document DE102012022879B4.

[0004] Even though a number of measures for reducing dust exposure, particularly for the operator, from dust generated during the milling process of a soil milling machine of this type are already known, the operating procedure is often still not optimal. Known extraction systems can usually only be activated and deactivated. However, the operating conditions for the soil milling machine frequently change. This can involve, for example, the individual operating conditions on site, which depend on the weather and soil material, or the current operating configuration of the soil milling machine itself. This can include different milling depths, milling operations that only affect a portion of the milling drum's width, and different positions of the elements sealing the milling drum housing at the bottom (front shield, scraper, side shields, etc.).The varying positions of the lifting mechanisms of the drive units, the swiveling and / or tilting positions of parts of the milled material conveying system, the different widths of the milling drum arranged in the milling drum housing, etc., create extremely diverse operating conditions for the soil milling machine, especially during milling operations. This necessitates that the extraction system be configured so that the suction generated by the extraction fan is reliably sufficient across the entire operating range to ensure effective extraction of dust-laden air from the milling drum housing under all the aforementioned conditions. Therefore, the dust extraction system is typically designed to generate a very high suction force at the milling drum housing, generated by the extraction fan, in the hope of ensuring sufficient suction for dust extraction under a wide variety of operating conditions.

[0005] However, this can be disadvantageous in several respects. For example, when using an electrostatic precipitator / separator located in the extraction duct, it is particularly advantageous if the flow velocities occurring in the electrostatic precipitator / separator are rather low, in order to enable the separation of relatively larger dust particles and / or to keep the required separation distance as compact as possible. Furthermore, a comparatively high negative pressure in the surrounding environment around the milling drum housing, especially in the area of ​​its lower edge, can create a kind of vacuum cleaner effect. In this way, dust generated during the milling process is also drawn in, along with any additional dust present outside the milling drum housing.Existing small particles are drawn in, which can significantly impair the separation efficiency of filter devices located in the extraction duct. Furthermore, the maximum filter capacity of the filter elements used can be reached relatively quickly, since naturally, at high suction pressure and / or suction velocities, comparatively larger particles are also drawn in, enter the extraction duct, and are conveyed to the corresponding filter element.

[0006] Based on this, the object of the invention is therefore to provide a way to improve the operation of an extraction device for extracting dust-containing air from the milling drum box of a soil milling machine.

[0007] The problem is solved using a soil milling machine and a method according to the independent claims. Preferred embodiments are specified in the dependent claims.

[0008] A soil milling machine of this type, in particular a road milling machine, recycler, or stabilizer, comprises a machine frame supported by transport devices, a drive motor, and a milling drum rotatably mounted in a milling drum housing arranged on the machine frame for removing soil material. The transport devices may be connected to the machine frame via height-adjustable lifting devices, such as lifting columns. During milling operation, dust may be generated by the milling process and / or by the transport of the milled material within the soil milling machine. To reduce the dust generated, an extraction system is provided to draw dust-laden air from the milling drum housing and / or a section of a conveying channel or a material conveying path. The extraction system includes at least one extraction fan capable of generating the suction required for extraction.The extraction fan can have at least one fan drive, in particular a fan motor, which drives, for example, at least one air-conveying element, such as an impeller. With the aid of the extraction fan, a suction effect and thus a directed airflow can be generated at the rotary tiller, through which dust-laden air can be drawn in. On the upstream side of the extraction fan, a negative pressure and thus the suction effect is generated during operation of the extraction fan by the conveying of the air. In order to extend the resulting suction effect to one of the locations relevant for dust generation in the milling process, in particular the interior of the milling drum housing and / or an area in the conveying channel of the milled material, for the extraction of dust-laden air, the extraction system also includes an extraction duct that runs from the milling drum housing and / or an area in the conveying channel of the milled material to the extraction fan.The extraction channel thus structurally refers to those areas of the soil milling machine which, in their interaction, enable the negative pressure or suction generated by the extraction fan to act as far as the milling drum housing and, in particular, as far as its interior and / or an area of ​​the conveying channel for the milled material, so that, due to the air conveying effect created by the extraction fan, a negative pressure is present inside the milling drum housing and / or in an area of ​​the conveying channel for the milled material during extraction, or can be generated by the extraction fan.It is understood that the extraction duct does not necessarily have to be essentially hermetically sealed, but that in practical use, leaks may occur at least in certain areas of the extraction duct between the interior of the milling drum housing and / or the conveying duct and the extraction fan, for example, at a transfer point from the interior of the milling drum housing to a conveyor belt, between successive conveyor belts in the conveying direction, at the material transfer point from the milling drum housing to the conveying device, etc. This can, however, be countered in a manner known per se by ensuring sufficient suction power from the extraction device. Furthermore, a discharge duct can be connected downstream of the extraction device, through which the extracted air, having passed through the extraction fan, can be blown out of the road milling machine in a specific area.This could be, for example, the end of a conveyor belt or another area of ​​the road milling machine.

[0009] It is essential that the extraction device according to the invention comprises a control device. The control device is designed such that the extraction capacity of the extraction device available for extracting dust-laden air from the milling drum housing and / or the area of ​​the conveying channel for the milled material can be changed, in particular regulated. In other words, the control device allows for a change, in particular a regulated change, in the operation of the extraction device such that the volume of air available per unit of time for extracting dust-laden air from the milling drum housing and / or an area of ​​the conveying channel for the milled material can be changed. With the help of the control device, the extraction device can thus, for example, be adjusted with regard to its current dust conveying capacity or...The suction power (e.g., air delivery volume per unit of time) can be adjusted and operated between at least two or more power levels and / or within a power range. In this context, it is explicitly stated that switching off or deactivating the extraction device, or in particular even just the extraction fan itself, for example, by stopping a fan wheel from rotating, is explicitly not to be understood as "operation of the extraction device." "Operation of the extraction device" is thus defined as occurring when the extraction fan is also delivering air. According to the invention, the extraction device can therefore be varied in suction mode, for example, between at least two or more power levels or within a power range, in which it delivers sometimes more and sometimes less air per unit of time under constant operating conditions.The system extracts dust from the milling drum housing and / or the material feed channel. The control unit is designed so that, for example, the extraction fan can be adjusted to at least two different speeds or within a speed range, particularly in a regulated manner. The higher the speed of the extraction fan, the more air is conveyed per unit of time, and the higher the extraction capacity can be. Thus, the extraction capacity currently available during operation of the rotary tiller is variable via the control unit, allowing for improved adjustment of the extraction capacity available for dust-laden air to the prevailing operating conditions of the rotary tiller.

[0010] Such an adjustment of the extraction capacity available for dust-laden air can be made manually, in particular by directly or indirectly controlling the speed of the extraction fan's drive motor using a suitable input device, such as a keypad, or the control unit. Specifically, it can be provided, for example, that an operator selects between at least two speeds of the extraction fan and / or within a speed range, for example, by means of a corresponding manual input. Additionally or alternatively, a variable dependent on the extraction fan's speed can also be specified, such as suction, negative pressure, a pressure differential, etc. The control unit can include a regulating device that adjusts or regulates the operation of the extraction fan, in particular its speed, within a defined range.The crucial point here is that control and / or regulation is achieved by influencing the operation of the extraction fan itself, particularly its speed and / or impeller position. Additionally or alternatively, control, especially regulation, of the extraction capacity of the extraction system at or within the milling drum housing and / or in a section of the conveying channel can also be achieved by influencing the design or configuration of the extraction channel of the extraction system through the control unit, in order to vary the extraction capacity available for extracting dust-laden air. For this purpose, the extraction system can, for example, include intake openings and / or channel sections whose cross-sectional area can be varied by the control unit, through which additional air is drawn into the extraction system to a variable extent.For this purpose, it may be provided that, for example, within a section of the extraction duct, a device controlled by the control unit, either automatically or manually, is present. This device could be one or more flaps, for instance, whose adjustment allows the flow cross-section of the extraction duct to be varied, in particular increased and / or decreased. Additionally or alternatively, elements controlled by the control unit may be present that allow ambient air to be drawn into the extraction duct in addition to the dust-laden air. In this embodiment, the area to which the suction effect generated by the extraction fan extends is thus variable, so that non-dust-laden air can also be drawn in, thereby reducing the proportion of suction available for extracting dust-laden air.Such an air supply device can, for example, be designed in the form of adjustable louvers and / or flaps covering an air passage opening in a wall of the extraction duct. By providing the control unit, the extraction capacity of the extraction system can be adapted to various working conditions, such as the current working and / or environmental conditions and / or machine configuration, and / or to the extraction result, depending on the requirements. How the current requirement can be determined and / or according to which criteria the control unit can even regulate itself automatically can vary and will be described in more detail below using examples. It is therefore essential that the extraction system, when activated, i.e.,The suction state can be operated by the control unit at least two power levels and / or variably within a power range with regard to the extraction capacity available for the extraction of dust-containing air.

[0011] In principle, it is possible for the control unit to set the current extraction capacity requirement based on one or more machine settings or configurations. For example, the control unit may be able to adjust the current extraction capacity, continuously or incrementally, within a controllable range of the extraction system, depending on factors such as the current milling depth, the relative position of a side plate, a hold-down device, one or more drive units, a conveyor, and / or any other ground contact element relative to the machine frame or a stationary reference point, the current machine inclination relative to the ground (whether transverse and / or longitudinal), the pivot position of a side plate relative to a milling drum housing or the machine frame, the width of a milling drum, the number and / or density of milling tools on the milling drum, etc., is regulated. For one or more of these operating parameters, corresponding characteristic maps or comparable data sets can be stored in a machine control system or similar device. Crucially, for each machine setting or configuration, at least one sensor is ideally available, designed for the direct and / or indirect acquisition of an actual value of the operating parameter(s). Based on this acquired actual value(s), the control unit then regulates the operation of the extraction system to achieve the desired setting. This preferred embodiment is thus characterized by the fact that the extraction system and its control unit are designed such that the regulation occurs depending on a setting position and / or change in setting and / or an operating state of a machine element, particularly during a milling process.This type of control can also be referred to as a configuration mode, since the operation of the extraction system depends on one or more machine configurations. The current machine configuration can be entered manually and / or determined by suitable sensors.

[0012] It is also possible, additionally or alternatively, for the control unit to regulate the extraction capacity to determine or consider operating parameters of the extraction system itself—that is, parameters or quantities that directly or indirectly result from the effect of the air extraction—and to use these to regulate the extraction capacity. For this purpose, the extraction system may include a sensor device that determines and / or monitors one or more quantities, in particular actual values ​​of one or more operating parameters of the extraction system and / or operating parameters of the rotary tiller influenced by it, which affect and / or depend on the extraction capacity available for extracting dust-laden air.The sensor device can be wirelessly and / or via cable connected to the control unit for data and / or signal transmission, so that the control unit regulates the extraction capacity of the extraction unit and / or its operating status based on the data and / or signals detected and / or monitored by the sensor device. It is therefore possible for the control unit to be designed in such a way that it regulates the extraction capacity available for extracting air from the milling drum housing as a function of an operating parameter of the extraction unit. In other words, this embodiment provides that the extraction capacity of the extraction unit, regulated by the control unit, monitors and takes into account one or more effects or consequences of the extraction work performed by the extraction unit via the sensor device, and the regulation thus takes place depending on these effects or consequences.Effects of the extraction process can include, for example, flow velocity, flow rate, the occurrence or, ideally, the absence of dust formation, pressure, especially a negative pressure compared to the outside environment, a pressure difference, suction force, and similar effects.

[0013] It is particularly advantageous, either additionally or alternatively, if the extraction system and its control unit are designed such that the extraction rate is regulated based on the current dust emission, especially dust emission from the milling drum housing into the external environment. In this case, the control unit is preferably designed such that, when dust or dust-laden air escapes from the milling drum housing, the extraction rate for air extraction from the milling drum housing is increased, for example, by increasing the fan speed of the extraction blower. Additionally or alternatively, it can also be provided that, when no dust-laden air escapes from the milling drum housing, the extraction rate is reduced, for example, by decreasing the fan speed of the extraction blower.In this context, it may also be stipulated that a minimum speed of the extraction fan and / or a minimum value of another effective parameter must not be undercut.

[0014] To determine the information usable for control by the control unit, the extraction system may include a sensor device. The sensor device or its individual sensors do not necessarily have to form a structurally integrated unit with the other elements of the extraction system. What is essential is that the sensor device has at least one sensor that provides the control unit with a sensor value representing an actual value. The control unit can use this value, not only for display to the operator, but preferably, and especially, for controlling the extraction capacity available for extracting dust-laden air.The sensor device can be designed to determine the current value and / or a correlated measured value of an active variable of the extraction system and / or a dust emission, which is particularly representative of the extraction of dust-laden air from the milling drum housing and / or the escape of dust from the milling drum housing to the outside environment. This does not mean that a value representative of the extraction of dust-laden air from the milling drum housing can only be determined if dust-laden air is actually being extracted from the milling drum housing. This value is also representative if, under the current operating conditions of the extraction system, it can be assumed that dust-contaminated air would also be extracted from the milling drum housing and / or a section of the conveying channel if dust were actually being generated.

[0015] Specifically, the sensor device can be designed, for example, such that an effective variable of the extraction system determined by it is at least an air pressure within the milling drum housing and / or within a section of the extraction duct, particularly with regard to the conveying path of the milled material between the milling drum housing and the extraction fan, and / or an air pressure difference between an air pressure within the milling drum housing and / or within a section of an extraction duct, particularly with regard to the conveying path of the milled material between the milling drum housing and the extraction fan, and an air pressure outside the milling drum housing and outside the extraction system, in particular the ambient air pressure of the soil milling machine. Using these air pressure measurements, it can be determined whether a negative pressure exists in the milling drum housing and / or within the respective section of the extraction duct.This occurs particularly when there is a suction effect at the respective point, directed towards the extraction fan. Additionally or alternatively, the sensor device can be designed to detect the direction of airflow into the interior of the milling drum housing, or more generally, the direction of airflow. Determining the flow velocity is also possible. Based on this (flow direction and / or flow velocity), it can be determined in which direction the air is flowing or whether a suction effect exists at the measuring point of the sensor(s). Furthermore, additionally or alternatively, the volume flow rate of air flowing into the interior of the milling drum housing and / or into the area of ​​the conveying channel, particularly from outside, can also be determined, which ultimately provides a quantitative assessment of the current suction effect.It is understood that the aforementioned effective variables can be determined directly and / or in the form of a measured quantity that correlates with the respective effective variable. The control device can preferably be designed such that it controls the extraction capacity available for the extraction of dust-laden air, in particular the rotational speed of an extraction fan, in such a way that a negative pressure and / or suction exists, but is as low as possible. For this purpose, a minimum limit value, for example for a pressure difference, flow velocity, etc., which must not be exceeded or fallen below, can be stored in the control device.

[0016] The specific selection of the sensor(s) used to detect an active variable of the extraction system can also vary. For example, if air pressure is to be detected, an air pressure sensor, particularly an electronic one, is preferred. This allows for absolute and / or relative air pressure measurements. In particular, a preferred air pressure sensor can be MEMS-based. Additionally or alternatively, a differential pressure sensor and / or a dynamic pressure sensor can also be part of the sensor system. Additionally or alternatively, one or more volumetric flow sensors, flow meters (especially vane anemometers), and / or flow direction sensors can be used.What all the aforementioned sensors have in common is that they either directly or indirectly provide information about air pressure or air movement by directly affecting the respective sensor, thus allowing conclusions to be drawn as to whether the currently available suction capacity is sufficient for extracting dust-laden air.

[0017] Alternatively or additionally, the sensor device may also include a means of detecting dust, particularly moving air containing dust. This can be achieved, for example, by using a camera, especially a digital camera and / or stereo camera. Furthermore, in this case, the sensor device may include suitable image processing software designed to detect or identify dust in air within one or more camera images. This can be done, for example, through image sharpness analysis and / or the identification of other phenomena characteristic of air containing dust, such as image comparison, video analysis, etc. Alternatively or additionally, a dust sensor or dust detector may be used to perform real-time dust measurement, preferably continuously.Such detectors are known, for example, under the trade names Microdust Pro CEL-712 or DustTrak II. A dust sensor can, in principle, incorporate a laser photometer, which uses light scattering measurements to detect dust. Additionally or alternatively, an optical dust sensor, particularly one based on a photometric measurement principle (extinction or scattering), can be used. Other dust sensors / detectors can also be employed.

[0018] There is also considerable flexibility regarding the placement of the sensor(s) on the soil milling machine. Ideally, the sensor(s) should be located at one or more points where meaningful sensor readings can be obtained for the ongoing extraction system during milling. Air pressure measurement, particularly differential pressure measurement, can include measurement of the ambient air pressure. It is advisable to position the suitable air pressure sensor, for example, on the milling drum housing. Alternatively, it can also be advantageous to position this air pressure sensor elsewhere on the soil milling machine, so that the sensor does not need to be reconnected when, for example, the milling drum housing is changed.An air pressure sensor for determining an internal pressure, for example within the milling drum housing and / or in a section of the material feed channel and / or within the extraction duct, is preferably arranged such that neither the material being milled nor dust-laden air flows directly over the sensor, in order to reduce, for example, the wear of any sensor housing that may be present. Accordingly, blind-hole-like measuring openings may be provided for this purpose, opening into the milling drum housing and / or the material feed channel and / or the extraction duct, with the respective pressure sensor located at the other end of these openings, so that a spatial connection with identical pressure conditions exists between the sensor and the measuring chamber.A differential air pressure sensor, volumetric flow sensor, flow meter, and / or flow direction sensor can, for example, be installed in a wall element of the milling drum housing, the conveying channel, and / or the extraction duct that defines the respective interior space. This allows air to be drawn in from outside this space during extraction operation, particularly from the external environment, and flow through this opening past the respective sensor into the interior space. The advantage here is that the air used for measurement does not necessarily have to be dusty. However, the potential mixing of dust-free air slightly reduces the efficiency of the extraction process, albeit only marginally. Therefore, it is also possible to position one of these sensors directly in the extraction duct itself, so that the extracted dusty air flows directly past the respective sensor.A key requirement for these types of sensors is that they are positioned within the suction area of ​​the extraction system. Regarding the camera and / or dust sensor placement, it is important that the camera's viewing direction is such that it captures an area where dust can escape from the milling drum housing, the conveyor system, and / or the extraction duct to the outside environment during milling operations. A particularly relevant area is the area where the lower edge of the milling drum housing meets the floor and / or the area of ​​the transfer opening in the milling drum housing onto a conveyor system. Accordingly, it can also be advantageous if the dust sensor is positioned at least near the lower edge of the milling drum housing. This could, for example, also be on the underside of the machine frame, particularly between the front and / or rear drive units.This area is generally suitable for camera placement. It may be sufficient if only part of the lower edge is captured by such a camera.

[0019] According to the invention, the control unit controls and / or regulates the extraction capacity available for dust-laden air depending on various machine configurations. This is based on the fundamental idea that changes in machine settings and / or configurations can influence how well or efficiently dust-laden air is extracted from the milling drum housing and / or the area of ​​the milled material's conveying channel at a given extraction capacity of the extraction device. Accordingly, it may be advantageous to increase or decrease the extraction capacity of the extraction device in certain configurations of the floor milling machine. This can be the case, for example, if one or more of the sealing elements of the milling drum housing towards the floor, such as the side plates and / or a scraper plate,The milling drums may not be optimally aligned between the ground surface and the rest of the milling machine, for example, due to misalignment, uneven ground, a milling edge within the milling width, etc. In such operating situations, it can be advantageous to adjust the extraction capacity of the dust extraction system to maintain sufficient dust removal, for example, to increase it, in order to compensate for a milling drum housing that is comparatively less dense than the ground surface. Additionally or alternatively, significantly more dust may be generated during so-called fine milling operations compared to milling at relatively large depths. In this case, it is advisable to aim for increased extraction capacity of the dust extraction system, for example, at shallow milling depths. A water-saving mode may also be incorporated.where the amount of water dispensed into the milling box during milling operations is reduced, for example, due to a low water level in the soil milling machine's water tank. Less water means that the tendency for increased dust generation increases. In this case, too, it can be advantageous to increase the extraction capacity for dust-laden air to compensate for the reduced water output for dust control. In a preferred embodiment of the invention, the sensor device is therefore also designed to determine the current value and / or a correlated measured variable of an adjustment position and / or change in adjustment and / or an operating state of at least one machine element.and that the control unit controls and / or regulates the extraction capacity available for drawing air from the milling drum housing as a function of at least this determined setting position and / or setting change and / or this determined operating state. It should be noted again at this point, for the avoidance of doubt, that switching an extraction fan on and off is explicitly not included in the regulation of the extraction capacity of the extraction device available for drawing air from the milling drum housing and / or the area of ​​the conveying channel for the milled material. It is therefore provided according to the invention that the sensor device is designed to determine the setting position and / or the setting change of the at least one machine element, specifically to determine the stroke position and / or stroke position change of a scraper plate of the milling drum housing, in particular relative to the machine frame.The device is designed to determine the lifting and / or pivoting position and / or changes in the lifting and / or pivoting position of at least one side plate of the milling drum housing, particularly relative to the machine frame, and to determine the actual milling width of a milling drum. Furthermore, it may be designed to determine the milling depth, the longitudinal and / or lateral tilt of the machine, the pivoting position and / or operating status of a belt conveyor, the lifting position of a hold-down device relative to the machine frame, and / or the tank level. Additionally or alternatively, the sensor device for determining the operating status may, for example, include a device for determining whether a milling drum of the soil milling machine is driven and / or rotating about its axis of rotation, and / or at what speed the milling drum rotates about its axis of rotation, a device for determining...whether the milling drum is in milling mode and / or in active milling machine feed, a device for determining a milling depth, a device for determining whether a water sprinkler system, which applies water into the interior of the milling drum housing and / or in the conveying area of ​​the milled material within the soil milling machine and / or in the area of ​​a material discharge point, is activated or deactivated and / or what the water discharge rate is per unit of time, a device for determining whether a particle filter device, in particular an electrostatic precipitator, is present and / or activated, a device for determining the operating status of one or more travel devices and / or one or more elements associated with the drive train of at least one of the travel devices. It is understood thatthat the aforementioned sensor values ​​can be determined directly and / or in the form of a measured quantity correlating with the respective position and / or change in position. Essential for this preferred embodiment is that the control device controls and / or regulates the extraction capacity available for extracting air from the milling drum housing as a function of at least one of the machine configurations, changes in machine settings and / or configurations, and / or operating states detected and / or monitored by the sensor device.

[0020] The specific design of the dust extraction system and its configuration for changing the extraction capacity available for extracting dust-laden air from the milling drum housing can also vary. For example, it is advantageous if the extraction fan has a fan drive motor whose drive speed and / or fan wheel speed is continuously adjustable, particularly within a speed range, and which is controlled by the control unit, specifically regulated by the control unit with regard to its target speed. It is understood that the fan drive motor has a suitable speed sensor for detecting the actual speed. The drive motor, in particular the fan drive motor, can be, in particular, an electrically, electro-hydraulically, or hydraulically driven drive motor.The drive of the blower drive motor, in particular a hydraulic or electric motor, is preferably carried out in such a way that the drive power supplied to it, whether in the form of hydraulic or electrical energy per unit of time, can be varied continuously and / or incrementally by the control device.

[0021] The dust extraction system can comprise a plurality of blower drive motors, each driving at least one fan wheel. It is advantageous if the multiple dust extraction systems and / or extraction fans are arranged at least partially in parallel with respect to their airflow, so that the air conveyed by them does not pass through several extraction fans in succession. To control / regulate the extraction capacity available for dust-laden air, it is then possible, for example, to switch individual extraction units, in particular extraction fans, on and off from a plurality of parallel-arranged units.

[0022] Additionally or alternatively, the dust extraction system can include an air supply device, particularly a controllable one, specifically comprising an air supply flap and / or damper with a variable opening area or flow cross-section. This allows dust-laden air, for example, non-dust-laden air, particularly from the external environment of the rotary tiller, to be mixed with the dust-laden air in the extraction duct, thereby ultimately influencing the extraction capacity available for dust-laden air (i.e., the proportion of the total extraction capacity of the system that can be used for dust-laden air). Such an air supply device can be arranged, in particular, in or on the extraction duct in the area between the milling drum housing and the extraction fan. Additionally or alternatively, a bypass intake of air is also possible.In this case, in addition to the extraction duct, an additional intake duct is present, particularly in direct flow connection with the extraction fan. Unlike the previous embodiment, there is therefore no mixing of the additionally drawn-in air with the drawn-in dust-laden air upstream of the extraction fan. Furthermore, or alternatively, elements can also be present in the extraction duct that modify the flow cross-section within the extraction duct and thus influence the extraction capacity available for dust-laden air.

[0023] The control device itself, insofar as it regulates the operation of the extraction system, can also be configured differently with regard to its control regime. For example, it is preferred if the control device is configured to regulate the extraction capacity available for drawing air from the milling drum housing up to a limit value that cannot be exceeded or fallen below. Additionally or alternatively, the control device can be configured to continuously regulate the extraction capacity available for drawing air from the milling drum housing within a limit value range. However, it is also possible for incremental or staged control to be implemented, in particular such that, in addition to a deactivated state of the extraction system, it can switch between at least two extraction capacities generated by the extraction system, especially speeds of the extraction fan.Additionally or alternatively, a regulation may be implemented to ensure that a flow velocity and / or a flow velocity range of a portion of the upstream extraction duct and / or the downstream discharge duct is not exceeded or fallen below. This could, for example, be the flow velocity of the extracted dust-laden air passing through a dust particle separator, in particular an electrostatic precipitator, viewed in the direction of flow, upstream, within, or downstream of such a separator.

[0024] The control unit can include a memory device with one or more characteristic maps that form the basis for the control, for example, as described above. Additionally or alternatively, the control unit can also include a learning mode. In this mode, an operator can, for example, manually change or adjust the extraction capacity available for air removal from the milling drum housing in a specific operating situation of the soil milling machine, for example, by manipulating the speed of the extraction fan, until a satisfactory setup is achieved.It may then be provided that the operator switches the control unit to a subsequent "control mode" in which the control unit regulates the extraction system, in particular the extraction capacity available for extracting dust-laden air, in response to changes occurring during operation, such that the available extraction capacity for dust-laden air selected in the learning mode is at least maintained and / or kept as constant as possible. Alternatively, the flow velocity of a separation element, in particular an electrostatic precipitator, can be monitored and set as a target value, especially within a defined range, for controlling the extraction system. Furthermore, predefined operating modes may be provided in addition to or as an alternative to one or more manually defined target values ​​for the control system.In this context, the control unit can, for example, be designed to maintain a defined negative pressure and / or a defined inflow velocity and / or a defined pressure differential between the internal pressure within the milling drum housing or the extraction duct and the external ambient pressure of the soil milling machine. This can be achieved, for example, by controlling the speed of the extraction fan. One or more predefined settings and / or setting modes can also be provided at the factory. Ideally, the control system should operate as a limit value control, ensuring that no dust escapes into the external environment.This can be achieved indirectly by setting a minimum internal negative pressure in the milling drum housing and / or a section of the extraction duct, or directly by monitoring actual dust emissions during operation of the floor milling machine, particularly using a dust sensor and / or at least one camera. Based on this basic arrangement, the control unit can, for example, continuously or incrementally reduce the extraction pressure for dust-laden air from a starting value that is known to be excessive, until dust is emitted from the milling drum housing and / or from an internal section of the extraction duct, and / or the dust emission increases significantly.The extraction capacity available for extracting dust-containing air can then be maintained at the current extraction rate or, preferably, increased again by a defined proportion in order to counteract the observed dust emission on the one hand, but on the other hand still be able to maintain the extraction capacity at a level lower than the starting value.

[0025] Another aspect of the invention relates to a method for operating an extraction device of a soil milling machine according to the invention for extracting dust-laden air from the milling drum housing and / or a section of a conveying channel for the milled material. A key feature of the method according to the invention is that the extraction capacity available for extracting air from the milling drum housing can be varied, in particular regulated, by means of a control device. Particularly during milling operations, it is possible for the control device to control and / or regulate the extraction capacity available for extracting dust-laden air.This allows the extraction capacity of the extraction device to be varied, especially during the milling operation of the soil milling machine, and adapted to operating conditions, whether with regard to a machine configuration and / or an effective parameter and / or an operating size of the soil milling machine, in particular as required.

[0026] The method according to the invention is particularly intended for use with a soil milling machine according to the invention. The method steps disclosed for the soil milling machine according to the invention thus represent, individually and in combination, preferred embodiments of the method according to the invention. Reference is made here to the relevant disclosure within the description of the soil milling machine according to the invention.

[0027] It is advantageous if the extraction rate is regulated by the control device depending on at least one operating parameter of the extraction device and / or a dust emission, in particular from the milling drum housing into the external environment, and / or an adjustment position and / or adjustment change or machine configuration and / or configuration change of a machine element and / or an operating state of at least one machine element. For possible operating parameters, dust emissions, adjustment positions and / or adjustment changes or machine configurations and / or configuration changes of one or more machine elements and / or operating states, reference is made to the preceding disclosure.

[0028] For the method according to the invention, it is preferred if at least one active parameter of the extraction device and / or a dust emission, in particular originating from the milling drum housing into the external environment, an adjustment position and / or change in setting or machine configuration and / or change in configuration of a machine element and / or an operating state of at least one machine element and / or a corresponding measured parameter is detected by means of a sensor device and transmitted to the control device for controlling, in particular for regulating, the extraction capacity available for extracting air from the milling drum housing. For possible active parameters, dust emissions, adjustment positions and / or changes in setting or machine configurations and / or changes in configuration of one or more machine elements and / or operating states, reference is made to the preceding disclosure.

[0029] There are various possibilities regarding the specific regulation of the extraction capacity available for the extraction of dust-containing air by the control device.For example, it is advantageous if the extraction capacity available for drawing air from the milling drum housing is regulated by changing the drive speed of one or more extraction fans of the extraction device from a first drive speed to at least a second drive speed, and / or by changing the drive power used to drive one or more extraction fans of the extraction device, and / or by adding or removing an extraction fan from another extraction fan of the extraction device, and / or by changing the flow cross-section in the extraction duct of the extraction device, and / or by changing an opening area through which air is drawn into the extraction device from outside the extraction device, and / or by controlling / regulating a supply air device. For further details, reference is made to the preceding disclosure.

[0030] The invention is explained in more detail below with reference to the embodiments shown in the figures. The figures schematically show: Figure 1: a side view of a soil tiller in a work train with a transport vehicle; Figure 2: an enlarged side view of the soil tiller according to Figure 1 Figure 3: an extraction device; and Figure 4: a flowchart of a process.

[0031] Identical or similarly functioning components are designated with the same reference numerals in the figures. Repeating components are not designated separately in each figure.

[0032] Figure 1 The figure shows a work train comprising a soil milling machine 1, here a road milling machine, and a transport vehicle 2, specifically a truck. The soil milling machine 1 is enlarged (except for part of the conveyor belt) and shown again in Figure 2 depicted.

[0033] The soil milling machine 1 has a machine frame 3, which forms the main supporting structure of the machine. The soil milling machine can be operated from a driver's platform 4, which may be partially open and / or closed, or designed as a driver's cab. The machine frame 3 is supported by front and rear drive units 5, viewed in the working direction a. These can be designed as tracked undercarriages or wheels. Some or all of the drive units 5 can be powered. The drive units 5 are mounted on the machine frame 3 via height-adjustable lifting devices 6, such as lifting columns. To provide the drive energy required for travel and milling operations, the soil milling machine 1 has a drive motor 7. This can be, for example, a diesel combustion engine or a comparable primary drive unit.The soil milling machine 1 has a milling unit 8, the essential components of which are a milling tool, in this case a milling drum 9, and a milling drum housing 10. The milling drum housing 10 surrounds the milling tool laterally and upwards, thus shielding the working area of ​​the milling tool from the external environment when it engages the subsoil. The milling tool can be a milling drum 9 comprising a substantially hollow cylindrical support tube, on the outer surface of which a plurality of milling chisels and / or similar milling tools are arranged. During milling operation of the soil milling machine 1, the milling drum engages the subsoil to a milling depth FT and, with continuous machine feed in the working direction a, mills away subsoil material.This material is collected inside the milling drum housing 10 and passes through a suitable outlet opening onto a material conveying device 11 of the soil milling machine 1. The material is conveyed by this device to a discharge point 14 on the side of the soil milling machine 1 and from there, for example, discharged into the transport vehicle 2 for removal of the milled material. The material conveying device 11 can, as in the present embodiment, have two conveying units arranged in series, in this case an inner conveyor belt 12 and an outer conveyor belt 13, or it can have only one conveying unit or even more than two. The soil milling machine thus includes a separate material conveying section for the milled material from the milling drum housing 10 to the discharge point 14. This conveying section for the milled material can be partially enclosed or shielded by housing elements, thereby creating a substantially shaft-like or...The conveyor has a channel-like structure and is therefore also referred to as a conveying channel. It is known, in particular for the inner conveyor belt 12, to arrange this within a receiving chute of the machine, such that parts of the machine frame and / or machine components surround a free space in which the inner conveyor belt and the milled material conveying section run. For the outer conveyor belt 13, it is known to arrange wall elements on the support frame of the outer conveyor belt to delimit the conveying section to the outside. It is also possible that the milled material conveying device 11 is not mounted with its discharge point facing forward in the forward direction a on the soil milling machine 1, as in the present case, but is additionally and / or alternatively oriented to one side and / or to the rear when viewed in the working direction A.A transfer point can be provided between the inner conveyor belt 12 and the outer conveyor belt 13, at which the milled material is discharged from the inner conveyor belt 12 onto the outer conveyor belt 13 in the conveying direction. In the present embodiment, the milling unit 8 is arranged in the working direction A between the front and rear drive units 5. This type of soil milling machine is also referred to as a mid-rotor milling machine. So-called rear-rotor milling machines are also known, in which the milling unit is arranged between the two rear drive units. The invention also extends to this type of soil milling machine.

[0034] Furthermore, so-called stabilizers and recyclers are known in the prior art as other types of soil milling machines. These can have a comparable design. Stabilizers serve to mill the subsoil and mix it with a binding agent. Recyclers mill soil material and can also mix additives into the milled material. Stabilizers and recyclers comprise a milling unit, but often no conveying device for the milled material, since the soil material they process regularly remains on the soil surface. The invention also extends to these machines in the manner described, but without the respective references to the conveying device for the milled material.

[0035] During the milling operation of the soil milling machine 1, a considerable amount of dust can be generated. This can be caused in particular by the milling work of the milling unit 8 itself and / or the transport of the milled material along the material conveyor. Accordingly, dust-laden air can escape into the surrounding environment, especially in the area of ​​the milling drum housing 10 and / or in the area of ​​the material conveyor 11, particularly in the area of ​​the inner conveyor belt 12, and / or at the discharge point 14.

[0036] Soil milling machines 1 of the present type can have a sprinkler system 15 with which water, in particular in the form of a spray mist, can be applied to the interior of the milling drum housing, a section of the material conveying path, and / or in the area of ​​the discharge point, among other things, to bind dust in dusty air. The figures show only exemplary outlet nozzles of the sprinkler system 15. This system further comprises at least one water tank and / or a suitable piping and / or valve system. The water applied to the interior of the milling drum housing can also be used for cooling the milling tools. The dust reduction achieved with the water sprinkler system 15 is regularly insufficient.

[0037] To reliably reduce dust emissions in the area of ​​the milling drum housing 10 and the milled material conveyor, the soil milling machine 1 includes an extraction device 16. This device can include an extraction fan 17 or other suction device, through which the dust-laden air can be extracted from the milled material conveyor and / or the milling drum housing 10 via an extraction duct 18. Regardless of the specific embodiment, the extraction fan can be, in particular, a radial fan. With the aid of the extraction fan 17, a volume of air can thus be conveyed, thereby creating a negative pressure and ultimately a suction effect on one suction side of the extraction fan 17.The extraction duct 18 allows areas of the milled material conveying system and / or the milling drum housing 10, specifically its interior, to be integrated into the suction effect generated by the extraction fan 17, such that dust-laden air present and / or generated there is extracted from the extraction fan 17 to the extraction fan. The extraction duct 18 thus defines the air path between the area of ​​the milled material conveying system and / or the milling drum housing, from which dust-laden air is extracted to the extraction fan. The extraction duct can extend at least partially into the space of the milled material conveying system, as shown in [reference]. Fig. 2shown in section I. The exemplary design of a possible extraction blower 17 and an extraction duct 18 described so far is known in the prior art and is described, for example, in EP3225738B1. It is also already known that a section of the extraction duct 18 runs along and / or through the milled material conveying path. In the present case, an extraction nozzle 20 can, in particular, project into the receiving chute of the inner conveyor belt 12 and run downstream of it in a line, in particular a pipeline, separate from the milled material conveying path, up to the extraction blower 17, as shown in Fig. 2This is shown as an example. With this arrangement, a particularly good suction effect can be achieved in the area of ​​the milled material conveying path, practically immediately adjacent to the point where the milled material is transferred from the milling drum housing to the milled material conveying device 11. This is also advantageous in that the suction effect generated by the extraction fan can then extend particularly effectively into the interior of the milling drum housing, so that dust-laden air can also be extracted from the interior of the milling drum housing. Additionally or alternatively, regardless of the specific design of the milled material conveying path and the milled material conveying device, it can be provided that the described extraction duct, which runs separately from the milled material conveying path, is connected directly to the interior of the milling drum housing 10.

[0038] In Figure 2To further clarify the above information, the movement of the milled material along the milled material conveying path is shown with arrows M1, M2 and M3, and the movement of the extracted dust-laden air is shown with arrows D1, D2, D3, D4 and D5 up to the extraction blower 17 (and in Fig. 3This is further indicated by arrows D6 and D7 (downstream of the extraction fan to the outlet). The milled material exits the interior of the milling drum housing 10 at arrow M1 and is transferred to the internal conveyor belt 12. This conveys the milled material along arrow M2 to the transfer point onto the external conveyor belt 13, from where it is transported along arrow M3 to the discharge point 14. Dusty air is extracted from the interior of the milling drum housing 10, via a common space (where the milled material is also transported according to arrow M1), towards the extraction fan 17, as indicated by arrow D1. The extraction area also extends over a portion of the interior of the soil milling machine 1 where the internal conveyor belt 12 runs, as illustrated by arrow D2. This space is in Figure 1The section labeled I is used for the spatial separation of the extracted dust-laden air and the milled material. This separation occurs at the extraction port 20 (D3), from which, looking downstream, the dust-laden air is guided spatially separated from the milled material to the extraction blower 17, as indicated by arrows D4 and D5. A further duct section 21 can be provided downstream of the extraction blower, through which the extracted air can be directed to a desired outlet point.

[0039] It may also be provided that the extracted and expelled air is guided along the path of the duct through a separation device 22, which is designed to separate dust particles contained in the dust-laden air from the airflow. An example of this is shown in Figure 2An electrostatic separator 22 is provided as a separation device through which the extracted dust-containing air is passed, in this case only as an example downstream of the extraction blower 17. The positioning of the separation device 22 in relation to the path of the extracted and expelled air, as well as its structural design, can vary. For example, cyclone filters, fabric filters, and similar separation devices 22 can also be used here. An arrangement upstream of the extraction blower is also possible.

[0040] Essential to the inventive design of the soil milling machine 1 is that the extraction device 16 comprises a control unit 19. The task and function of the control unit 19 is to regulate the extraction capacity of the extraction device 16, in particular the extraction blower 17, available for extracting air from the milling drum housing and / or the area of ​​the conveying channel for the milled material. The control unit 19 thus makes it possible to change the extraction capacity available for extracting dust-containing air from the milling drum housing and / or the area of ​​the conveying channel for the milled material and thus, for example, to react to changing operating conditions of the soil milling machine 1. Simply switching the device on and off is not sufficient.By activating and deactivating the extraction device, it is at least possible, according to the invention, to vary the activated state of the extraction device, i.e., a state in which dust-laden air is extracted, between at least two operating stages that differ with respect to the extraction capacity available for extracting dust-laden air, and / or within a possible operating range in which the extraction capacity available for extracting dust-laden air can be changed, and / or the operating state of the extraction device, in particular the drive and / or fan speed of the extraction blower. This also allows, in particular, the extraction of dust-laden air from the relevant areas of the soil milling machine 1 described above to be adapted to the current requirements or to operating situations with increased or decreased dust generation.With regard to further developments according to the invention, explicit reference is also made to the variations disclosed above before the description of the figures, which are not necessarily shown explicitly in every detail in the figures.

[0041] The control unit 19 preferably controls a device of the extraction unit 16, with the aid of which the extraction capacity available for extracting dust-containing air can be varied. This can be done, for example, by controlling a blower drive unit 23, such as an electric and / or hydraulic motor. Figure 2A control line 24 is provided for this purpose, connecting the control unit 19 to the blower drive unit 23. Additionally or alternatively, a controllable supply air device 25 can also be provided upstream of the extraction blower 17. The supply air device 25 can be a device with a supply air opening through which additional air, particularly dust-free air, can be drawn in from the outside environment of the soil milling machine 1. The cross-sectional area of ​​the supply air opening can be variable to adjust the amount of additional ambient air flowing in. Controllable, driven flap and / or louver elements or similar devices can be provided for this purpose.A variable proportion of the extraction power generated by the extraction fan 17 can then be diverted to the intake of dust-free air by means of the supply air device 25, so that, as a result, less extraction power is available overall for extracting dust-containing air, and vice versa. The supply air device 25 can also be connected to the control unit 19 via a control line. It should be noted here, for the avoidance of doubt, that the design of the control lines and / or signal lines mentioned in the invention is obviously variable with regard to the specific embodiment and that, for example, wired and / or wireless signal and / or control lines can be used. Furthermore, or alternatively, the angle of the fan blades can also be changed and adjusted by the control unit 19 to alter the extraction power of the extraction device 16.It goes without saying that in this case the fan wheel has correspondingly adjustable guide vanes.

[0042] In order to adapt the extraction capacity available for regulating the extraction of dust-laden air to different conditions, the extraction device 16 can include a sensor device 26. This can be varied in many respects and is used in particular in connection with the Figure 3 explained in more detail. In the exemplary embodiment according to the Figure 1 and 2The sensor device 26 can include a camera 27, which is arranged on the floor milling machine 1 such that its field of view captures an area, particularly between the lower edge of the milling drum housing 10 and the floor covering B, in which dust-laden air can escape from inside the milling drum housing 10 to the outside environment. Using suitable image processing software, the acquired image information can then be used to determine whether the recorded image(s) show a dust cloud or not, for example, through image comparisons, 3D image analysis, and / or similar methods. Additionally or alternatively, a pressure sensor 28 is arranged on and / or in the milling drum housing, which can be used to determine whether and / or how high a negative pressure is inside the milling drum housing 10. If a negative pressure exists there, this indicates that dust-laden air is being extracted from inside the milling drum housing towards the extraction fan 17.This provides suction power at the milling drum housing. The sensor 28 can also be a flow direction sensor or similar device, which can be used to determine whether air is drawn into the milling drum housing from the outside environment via this sensor due to a negative pressure maintained inside the milling drum housing 10. It is understood that the corresponding sensors are also in signal communication with the control unit 19.

[0043] Figure 3Figure 1 illustrates the interaction of the control unit 19 with other elements of the extraction system 16. The control unit 19, which, regardless of the specific embodiment, can be a control device, can, for example, control the blower drive unit 23 via the control line 24. Furthermore, a feedback line 29 can be provided, via which the control unit 19 can receive actual operating data for the operation of the blower drive unit 23, such as the current fan speed. Additionally, a control line 30 can connect the control unit 19 to the supply air unit 25. This unit can, for example, have a driven damper and a supply air opening variably covered by it, which is in flow connection with the extraction duct 18. The supply air unit 25 can also report information about its current status back to the control unit 19.The control commands transmitted by the control unit 19 to the blower drive unit 23 and / or supply air unit 25 in the present embodiment can be based on operating data obtained via the sensor unit 26.

[0044] The sensor arrangement 26 can include one or more sensors that record relevant actual operating data for the current dust generation of the soil milling machine 1. For example, the sensor arrangement 26 can be configured to record an active parameter of the extraction system 16. Examples of such sensors are shown in section 26.1. Figure 3The following are specified. For example, a pressure sensor 28 may be provided for this purpose, which can detect the air pressure existing within the milling drum housing and / or within a section of the extraction duct 18, in particular between the milling drum housing 10 and the extraction fan 17. Additionally or alternatively, a differential air pressure sensor 30 may also be provided, which is designed to determine the air pressure difference between the milling drum housing 10 and / or within a section of the extraction duct, in particular between the milling drum housing and the extraction fan, and the air pressure outside the milling drum housing 10 and outside the extraction device, in particular the ambient air pressure of the soil milling machine 1. The differential air pressure sensor 30 may, for example, comprise two air pressure sensors arranged at suitable locations to determine the existing air pressure difference (inside vs. outside).Additionally or alternatively, a flow direction sensor 31 and / or a volume flow sensor 32 can also be components of the sensor assembly 26, which can be used to determine the existence of a directed airflow and / or the extent of an existing airflow. The sensors 31 and / or 32 can be integrated into a corresponding through-measuring opening in one of the wall elements of the milling drum housing 10 and / or the extraction duct 18. If a negative pressure exists in one or both of these areas, air from outside is drawn into the interior of the milling drum housing and / or the extraction duct 18 through the corresponding through-measuring opening at and / or through the sensors 31 and / or 32. Furthermore, additionally or alternatively, a flow velocity sensor (not shown in detail) can also be present, which determines the flow velocity of the extracted dust-laden air and / or the air blown out downstream of the extraction fan.Such a flow velocity sensor can be particularly useful in combination with a separation device, especially an electrostatic precipitator and / or a cyclone separator, whereby the flow velocity sensor can be positioned upstream, inside, or downstream of the separation device, viewed in the direction of flow. For an electrostatic precipitator, for example, it may be advantageous to ensure that a maximum flow velocity is not exceeded to prevent already deposited material from being re-entrained by the airflow. Conversely, for a cyclone separator, it may be advantageous to ensure that a minimum flow velocity is not undercut to guarantee a sufficiently effective separation process.It is also possible to define a flow velocity range within which the flow velocity of the extracted dust-laden air should lie (obviously always in relation to the specific measuring point). This can be defined, particularly when using a combined cyclone separator and an electrostatic precipitator, both arranged in series, by the maximum and minimum flow velocities described above.

[0045] Additionally or alternatively, the sensor device 26 can include a sensor that determines a measured value that correlates with actual dust generation and / or dust emission, in particular from the interior of the milling drum housing 10 to the outside environment and / or from the conveyor section or the milled material conveying device 11 to the outside environment, and transmits this value to the control device 19. Examples of suitable sensors for this purpose are listed in subgroup 26.2 of the sensor device 26. Figure 3As specified. In addition to the camera 27 and suitable image processing software, a dust sensor or dust detector 33 can also be used, either additionally or alternatively. Such a dust sensor can, for example, provide a qualitative and / or quantitative assessment of the current dust load in the air supplied to the dust sensor, based on a photometric measuring principle (extension or dispersion). The dust sensor 33 is advantageously positioned on the soil milling machine 1 in an area where dust escaping from the interior of the milling drum housing and / or the material conveying system will be present during milling operation of the soil milling machine 1. This can be, in particular, the external area surrounding the milling drum housing 10, the external area around and / or along the elements of the soil milling machine 1 that enclose the material conveying system.Particularly with regard to unwanted dust exposure of the operator of the soil milling machine 1, such a dust sensor 33 can also be located in the area of ​​the operator's station 4. Since the locations where dust can potentially escape from the areas mentioned here into the outside environment are also dependent on wind, it is advisable to simultaneously install and monitor such sensors at several potentially relevant locations on the soil milling machine 1. Regardless, it should be noted as a precaution that dust emissions from the milling drum housing and / or the material conveying system do not necessarily have to be directed towards the outside environment and do not have to serve as a measure of dust emissions. Of course, there may also be areas within the soil milling machine 1, for example in the intake chute of the internal conveyor belt, where dust can (also) escape.Of course, dust emissions can also be determined at these locations in the manner described above.

[0046] Additionally or alternatively, the sensor device 26 can also comprise one or more sensors with which the operating state of at least one machine element can be determined. This sensor group is described in block 26.3 in Figure 3specified. In particular, the sensor device 26 can include a position sensor 34 designed to determine the position and / or a change in position of a machine element of the soil milling machine 1 relative to another element. This could be, for example, the stroke position of a lifting device connecting a drive unit to the machine frame, the stroke and / or pivot position of a side plate relative to the rest of the milling drum housing and / or the machine frame, the stroke position of a scraper plate, the pivot position of a part of the milled material conveying device 11, or similar. These adjustable elements can influence, for example, the tightness of the milling drum housing 10 and / or the extraction duct 18 and thus be an indicator of when, for example, the speed of the extraction fan 17 can be increased or decreased to prevent dust from escaping to the outside.The control unit 19 can, in particular for this case, also include one or more characteristic maps which summarize different control and / or regulation parameters controlled by the control unit 19 for certain configurations of the soil milling machine 1.

[0047] Category 26.3 of sensors of the sensor device 26 also includes, additionally or alternatively, sensors with which the operating state of elements of the soil milling machine, in particular with regard to activation and / or the activation itself, can be determined and transmitted to the control device 19. Such operating state sensors are in Figure 3Designated above with reference numeral 35. Such operating condition sensors can, for example, be designed to detect the operating condition of the milling drum 9, the sprinkler system 15, the milled material conveying device 11, the separating device 22 or similar in the manner described above and transmit it to the control unit 19.

[0048] All of the sensor measurements described above can be direct measurements of the determined quantity and / or values ​​correlating with it.

[0049] Figure 4 illustrates possible embodiments of a method according to the invention, in particular for a soil milling machine 1 with a control device 19, as shown in the Figure 1 , 2 and 3 Described using an example.

[0050] The central aspect of the method according to the invention is the control, in particular regulation 36, of the suction capacity available for extracting air from the milling drum housing by means of a control device, in particular the control device 19. For this purpose, it can be provided that the control, in particular regulation 36, comprises the transmission 37 of control commands to a device for changing the suction capacity available for extracting air from the milling drum housing. This device can, in particular, be a blower drive device, such as a hydraulically and / or electrically driven fan motor, and / or an air supply device. With the help of the transmitted control command, the current operating state of the suction device with regard to the suction capacity available for extracting air from the milling drum housing can thus be changed in step 38.It is understood that this can be done unidirectionally or bidirectionally, whereby in the latter case the control unit receives feedback on the new actual value of the respective operating state of the extraction device resulting from the change.

[0051] In particular, the control 36 can be dependent on various parameters. For example, the transmission 39 of an effective parameter of the extraction system can be provided. This could, for example, be a pressure measurement. For this and other alternatives, reference is made to the preceding explanations. Additionally or alternatively, the transmission 40 of a current dust emission can also be provided, with reference again to the preceding explanations for further details. Furthermore, additionally or alternatively, it is also possible that the transmission 41 of a setting position and / or change in setting position of a machine element and / or an operating state of at least one machine element is provided, depending on which the control 36 of the extraction capacity can be carried out. For further details again, reference is made to the preceding explanations.

[0052] The actual values ​​shown in steps 39, 40, and 41 can be recorded during the ongoing milling operation using suitable sensors in steps 42, 43, and 44. Which sensors and measurement locations are preferable has already been described above, so reference is made here to the preceding explanations regarding this matter.

[0053] The steps described above can be carried out continuously during milling operations. The effects of the change 38 can be detected, in particular via steps 42 and 43, and further considered for the rule 36. This is in Figure 4 Listed as 45.

[0054] In principle, the inventive method can be designed with regard to the extraction capacity available for dust-containing air such that at least two performance levels, for example, at least two different speeds of an extraction fan, can be set depending on the parameters described above. A substantially stepless change, in particular of the speed of an extraction fan, within a speed range is also possible. However, it is optimal if the extraction capacity available for dust-containing air is not permanently set too high. If the extraction capacity available for dust-like air is set too high, this is disadvantageous from both an energy and environmental perspective.On the other hand, this can negatively affect the separation efficiency of one or more existing separation devices. For example, excessively high extraction rates and the associated comparatively high flow velocities within the extraction duct can negatively impact the separation rate of an electrostatic precipitator. Therefore, rule 36 is preferably implemented such that the extraction device is operated at the lowest possible extraction rate available for extracting dust-laden air. Using the arrangement described above, this can be achieved, for example, by aiming for only a comparatively low negative pressure and / or a comparatively low inflow of air into the milling drum housing or similar components. Specific, practical limit values ​​regularly depend on the actual structural conditions.

[0055] In this context, it is particularly efficient with regard to the operation of the extraction device and simultaneously with regard to dust extraction if a possible dust emission from the milling drum housing and / or a section of the milled material conveying device is monitored, as already described above, and the extraction capacity is regulated such that no dust, or at least only a very small amount of dust, escapes. The control 36 is thus preferably implemented as a limit load control, where the limit load here is the prevention of dust emission from the milling drum housing and / or a section of the milled material conveying device, particularly into the external environment. The control device 19 can therefore also be designed as a limit load control device, irrespective of the above merely exemplary details of the inventive method.

Claims

1. A ground milling machine (1), in particular a road milling machine, recycler or stabilizer, for working a ground in or against a working direction (a), comprising - a machine frame (3) supported by travel units (5) and having a drive motor (7), - a milling drum (9) rotatably mounted in a milling drum box (10) arranged on the machine frame (3) for removing ground material, and - an extraction device (16) for extracting dust-laden air from the milling drum box (10) and / or a region of a conveying duct of the milled material, comprising an extraction fan (17) and at least one extraction duct (18) extending from the milling drum box (10) to the extraction fan (17), wherein the extraction device (16) comprises a control device and is configured such that, with the aid of the control device (19), the extraction power of the extraction device (16) available for extracting dust-laden air from the milling drum box (10) and / or the region of the conveying duct of the milled material can be varied, characterized in that the extraction device (16) comprises a sensor device (26) configured such that it determines the current value, and / or a measured variable correlating therewith, of a setting position and / or setting change of at least one machine element, wherein the sensor device (26) is configured to determine the setting position and / or the setting change of the at least one machine element and has at least one of the following features: - it is configured to determine a lifting position and / or lifting position change of a stripping plate of the milling drum box (10), in particular relative to the machine frame; - it is configured to determine a lifting and / or pivoting position and / or lifting and / or pivoting position change of at least one side shield of the milling drum box (10), in particular relative to the machine frame; - it is configured to determine an actual milling width of a milling drum (9), and that the control device (19) regulates the extraction power available for extracting air from the milling drum box (10) as a function of at least this determined setting position and / or setting change.

2. The ground milling machine (1) according to claim 1, characterized in that the control device (19) is configured such that it regulates the extraction power available for extracting air from the milling drum box (10) as a function of - an effect-related variable of the extraction device (16) and / or - a dust emission and / or - a setting position and / or setting change and / or an operating state of a machine element, in particular during a milling process.

3. The ground milling machine (1) according to any one of the preceding claims, characterized in that the extraction device (16) comprises a sensor device configured such that it determines a current value, and / or a measured variable correlating therewith, of an effect-related variable of the extraction device (16) and / or of a dust emission, which is in particular representative of - extraction of air from the milling drum box (10) and / or - escape of dust from the milling drum box (10) to the external environment.

4. The ground milling machine (1) according to any one of the preceding claims, characterized in that the extraction device (16) comprises a sensor device (26) configured such that an effect-related variable of the extraction device (16) determined by it is at least one of the following effect-related variables and / or a measured variable which correlates with the respective effect-related variable: - an air pressure within the milling drum box (10) and / or within a region of an extraction duct (18), in particular between the milling drum box (10) and the extraction fan; - an air pressure difference between an air pressure inside the milling drum box (10) and / or inside a region of an extraction duct, in particular between the milling drum box (10) and the extraction fan, and an air pressure outside the milling drum box (10) and outside the extraction device (16), in particular an ambient air pressure of the ground milling machine (1); - a direction of air inflow into an interior of the milling drum box (10); - a volumetric flow of air flowing into the interior of the milling drum box (10).

5. The ground milling machine (1) according to any one of the preceding claims, characterized in that the extraction device (16) comprises a sensor device (26) having at least one of the following sensors: - an air pressure sensor; - an air pressure difference sensor; - a back pressure sensor; - a volumetric flow sensor; - a flow direction sensor; - a camera; - a dust detector.

6. The ground milling machine (1) according to any one of the preceding claims, characterized in that the extraction device (16) comprises a sensor device (26) which has at least one of the following features for determining the operating state of the at least one machine element: - a device for determining whether a milling drum (9) of the ground milling machine (1) is driven and / or rotates about its rotation axis and / or at what speed the milling drum rotates about its rotation axis; - a device for determining whether the milling drum is in milling operation; - a device for determining a milling depth; - a device for determining whether a water sprinkler system, which applies water to the interior of the milling drum box (10) and / or a conveying region of the milled material within the ground milling machine (1) and / or a region of a material discharge point, is activated or deactivated; - a device for determining whether a particulate filter device, in particular an electrostatic separator, is present and / or activated; and in that the control device (19) regulates the extraction power available for extracting air from the milling drum box (10) as a function of at least one of these operating states.

7. The ground milling machine (1) according to any one of the preceding claims, characterized in that the dust extraction device (16) has at least one of the following features for varying the extraction power available for extracting air from the milling drum box (10): - the extraction fan comprises a fan drive motor, in particular a hydraulic or electric motor, which is continuously adjustable with regard to its drive speed, in particular within a speed range; - the fan drive motor, in particular a hydraulic or electric motor, is driven such that the drive power supplied to it for the extraction fan is varied by the control device (19), - it comprises a plurality of fan drive motors each driving at least one fan wheel; - it comprises an air supply device, in particular a controllable air supply device, in particular comprising an air supply flap / slide valve which is variable with respect to its opening area.

8. The ground milling machine (1) according to any one of the preceding claims, characterized in that the control device (19) is configured such that it regulates the extraction power available for extracting air from the milling drum box (10) - toward a limit value not to be exceeded or fallen below; - continuously within a limit value range; or - in addition to a deactivated state of the extraction device (16), between at least two extraction powers generated by the extraction device (16).

9. A method for operating a dust extraction device (16) of the ground milling machine (1) according to any one of the preceding claims, characterized in that the extraction power available for extracting air from the milling drum box (10) can be varied, in particular in a regulated manner, with the aid of a control device (19).

10. The method according to claim 9, characterized in that the extraction power is regulated as a function of at least - an effect-related variable of the extraction device (16) and / or - a dust emission and / or - a setting position and / or setting change of a machine element and / or - an operating state of at least one machine element.

11. The method according to any one of claims 9 or 10, characterized in that with the aid of a sensor device (26), at least - an effect-related variable of the extraction device (16) and / or - a dust emission and / or - a setting position and / or setting change of a machine element and / or - an operating state of at least one machine element and / or a measured variable correlating therewith is detected and transmitted to the control device (19) for regulating the extraction power available for extracting air from the milling drum box (10).

12. The method according to any one of claims 9 to 11, characterized in that the extraction power available for extracting air from the milling drum box (10) is regulated - by changing a drive speed of one or more extraction fans of the extraction device (16) from a first drive speed to at least a second drive speed; and / or - by changing a drive power used to drive one or more extraction fans of the extraction device (16); and / or - by adding or disconnecting an extraction fan to / from another extraction fan of the extraction device (16); - by changing a flow cross-section in an extraction duct of the extraction device (16); - and / or by changing an opening area through which air is drawn in by the extraction device (16) from outside the extraction device (16).