Self-propelled construction machine and method for operating a self-propelled construction machine

Abstract

The invention relates to a self-propelled construction machine, which has a machine frame, a milling drum arranged in a milling drum housing, an adjustment device for adjusting the height position of a sealing element relative to the milling drum, and a control device for controlling the adjustment device of at least one sealing element, the milling drum housing having a sealing device including a sealing element, the sealing element being arranged behind the milling drum in the working direction of the construction machine for closing the milling drum housing. The construction machine is characterized in that the sealing device has at least one scraper element, which is pivotably arranged on at least one sealing element so that the scraper element rests on the milled material, the scraper element is pulled over the milled material as the construction machine advances and pivots relative to the milling drum based on the height of the milled material. The height position of at least one sealing element (12) is adjusted based on the pivot position of the scraper element so that the pivot position of the scraper element is within a predetermined pivot range when the construction machine advances.

Description

Technical Field

[0001] The present invention relates to a self-propelled construction machine, in particular a road milling machine, a regenerator or a stabilizer, which comprises a machine frame, a milling drum, an adjustment device and a control device, wherein the milling drum is arranged in a milling drum housing, the milling drum housing has a sealing device, the sealing device has at least one sealing element, the sealing element is arranged behind the milling drum in the working direction of the construction machine for closing the milling drum housing, the adjustment device is used to adjust the height position of the sealing element relative to the milling drum, and the control device is used to control the adjustment device of the sealing element. Background Art

[0002] With known road milling machines, the road surface can be milled away to the actual contour and evenly. A distinction must be made between road milling machines and so-called stabilizers or recyclers, which, by adding a binder, produce a load-bearing substructure from a substructure of a non-load-bearing substrate, such as loose soil (stabilizer) or damaged roadway (recycler), which is suitable for the subsequent construction of a roadway. Road milling machines and stabilizers or recyclers have a working drum, hereinafter referred to as a milling drum, for preparing the ground.

[0003] Road milling machines have a transport device in order to be able to transfer all the milled material from the milling drum housing to the transport vehicle (complete material loading). The volume of milled material to be transported from the milling drum housing is determined by the width of the milling drum (milling width) and the milling depth. When the milled material is to be loaded during operation, the lower edge of the height-adjustable sealing element of the sealing device slides or scrapes on the milled surface so that the surface is stripped clean. Therefore, in road milling machines, the sealing element is also called a scraper element or a scraper or a scraper. The milling drum housing is closed behind the milling drum in the working direction by the sealing element.

[0004] In addition to the rear sealing element, road milling machines also have a sealing element arranged in front of the milling drum in the working direction, which is also called a hold-down device. In addition to the hold-down device and the scraper, road milling machines have left and right edge protection devices extending in the working direction, which close the milling drum housing laterally.

[0005] The road milling machine also offers a further operating mode in which only part of the milled material (partial material loading) or no milled material (no material loading) is loaded, so that the remainder of the milled material or all of the milled material remains in the milling track. For this operating mode, it is necessary to raise the sealing element. However, if the sealing element is positioned too low above the remaining milled material, the milled material remains in the milling drum housing, so that the milling drum housing is increasingly filled with material, which generates additional friction and reduces efficiency and increases wear and fuel consumption. On the other hand, the sealing element cannot be raised as required, otherwise the milling drum housing would be at least partially open behind the milling drum in the working direction. However, the milling drum housing should always be largely closed, otherwise the milled material could be thrown out of the milling drum housing and there is a risk of accidentally entering the milling drum housing.

[0006] The stabilizing machine has no transport device. Therefore, during stabilization, the sealing element which seals the drum housing backwards must be adjusted so that the material can escape from the drum housing. This is also the case for the embodiment of the regenerating machine without transport device.

[0007] DE 10 2013 013 967 A1 describes a road milling machine with a sealing device having a height-adjustable sealing element. The construction machine has a control device, which is adapted to be an adjustment device for adjusting the height of the sealing element, and a measuring device for measuring the distance between the lower edge of the sealing element and the milled material remaining in the milling track. The control device is designed so that the height of the sealing element is adjusted based on the height of the milled material. This ensures that the milled material can escape from the milling drum housing behind the milling drum in the working direction essentially unhindered and that the milling drum housing is essentially closed above the discharged material. However, it is disadvantageous that an additional distance measuring device with a corresponding sensor system must be provided. In addition, in an operating mode with incomplete loading of the milled material, the milled material cannot be stripped off due to the gap between the lower edge of the sealing element and the material. Summary of the invention

[0008] The problem solved by the invention is to provide a self-propelled construction machine, in particular a road milling machine, which can also be operated when the milling material is not loaded, at least not completely loaded, but is to be kept at least to some extent on the milling track. Another problem solved by the invention is to specify a method for operating a self-propelled construction machine when the milling material is not loaded, at least not completely loaded, but is to be kept in the milling track.

[0009] According to the present invention, these problems are solved by the following features.

[0010] The self-propelled construction machine according to the invention is in particular a road milling machine, which in particular has a transport device for transferring the milled material from the milling drum housing to a transport vehicle. The road milling machine can be a front-loading road milling machine, with which the milled material can be loaded over the front of the machine onto a truck traveling ahead, or a rear-loading road milling machine, with which the milled material can be loaded over the rear onto a truck following behind.

[0011] The self-propelled construction machine comprises a machine frame and a milling drum, wherein the milling drum is arranged in a milling drum housing, and the milling drum housing comprises a sealing device, wherein the sealing device comprises at least one sealing element for closing the milling drum housing and arranged behind the milling drum in the working direction of the construction machine, an adjusting device for adjusting the height position of the sealing element relative to the milling drum, and a control device for controlling the adjusting device of at least one sealing element.

[0012] A sealing element is any element by which the milling drum housing is closed towards the ground. However, this does not mean that the drum housing is completely sealed. However, the sealing element prevents milled material from being thrown out of the milling drum housing and accidentally entering the drum housing. Since the sealing element in the construction machine according to the invention does not have to be used to scrape off the milled material, the sealing element does not have to rest on the milled material.

[0013] A self-propelled construction machine, characterized in that the sealing device has at least one scraper element which is pivotably arranged on at least one sealing element so that the at least one scraper element rests on the milled material in one operating mode of the construction machine. In this way, when the scraper element is pulled over the milled material with the advancing construction machine, the scraper element pivots relative to the milling drum based on the height of the milled material. Thus, a "scraper element" is understood to be any element that can be pulled over the surface of the milled material.

[0014] The operating modes of the construction machine described above may be operating modes specified by the machine operator. However, the construction machine may also provide other operating modes that may be specified by the machine operator, in which the sealing element and / or the scraper element assume other positions.

[0015] The self-propelled construction machine has a measuring device for determining the pivot position of at least one scraper element. The measuring device generates a measuring signal which is related to the pivot position and is received by a control device of an adjustment device of at least one sealing element. The measuring signal can be an analog or digital measuring signal describing the pivot position of the scraper element. The pivot position of the scraper element is in turn determined by the height of the milled material supporting the pivotable scraper element.

[0016] The control device of the adjustment device of at least one sealing element is configured so that the adjustment device adjusts the height position of at least one sealing element based on the pivot position of at least one scraper element so that the pivot position of the scraper element is within a predetermined pivot range. This ensures that at least one sealing element is always in the correct height position when the construction machine is advancing, without the risk of milled material being retained in the milling drum housing and accidentally entering the drum housing. If milled material accumulates in the drum housing, the sealing element is automatically raised. For example, if the milling parameters (for example, the forward speed and / or the milling depth) change, or if the volume of milled material removed from the drum housing per unit time is insufficient, milled material may accumulate in the milling drum housing, thereby loading the milled material.

[0017] In the construction machine according to the invention, the scraper element not only serves to scrape off the milled material, but also serves as a tactile element for scanning the milled material remaining in the milling track.

[0018] For the functional principle of the invention, it is irrelevant how the adjustment device for raising and lowering the at least one sealing element is designed.

[0019] It is also irrelevant how the scraper element is designed, as long as the scraper element rests on the milled material with sufficient contact force to be able to scrape off the milled material. Therefore, the scraper element should not just slide on the milled material. The contact force of the scraper element can be its weight. However, the scraper element can also press on the milled material with a contact force that is greater than the weight of the scraper element.

[0020] The specified pivoting range of the scraper element may be defined by an upper limit value and a lower limit value.The pivoting range may be fixed for the construction machine or may be specified by the machine operator.

[0021] One embodiment of the invention is provided such that the control device of the adjustment device of at least one sealing element is configured such that the adjustment device raises the at least one sealing element when the scraper element pivots upwards during the advancement of the construction machine and lowers the sealing element when the scraper element pivots downwards during the advancement of the construction machine. The height of the sealing element can be adjusted in a continuous process so that the movement of the sealing element follows the movement of the scraper element.

[0022] The control device of the adjustment device of at least one sealing element can be configured so that, when the angle between the scraper element and the sealing element is set to be greater than an upper limit value, the adjustment device raises at least one sealing element, and when the angle between the scraper element and the sealing element is set to be less than a lower limit value, the sealing element is lowered. In this case, the angle between the scraper element and the sealing element is defined, which increases when the scraper element is raised and decreases when the scraper element is lowered, which corresponds to the minimum cutting angle. If another angle is defined, the movement occurs in a similar manner. By specifying the limit values ​​of the corresponding angles, the permissible pivoting range can be determined and thus the reaction time of the system.

[0023] Another embodiment is provided such that the upper part of at least one scraper element is fastened to the sealing element so that it can pivot about an axis extending parallel to the axis of rotation of the milling drum. The scraper element is preferably mounted in an articulated manner at its uppermost edge. In principle, the scraper element does not need to be fastened directly to the sealing element. However, the scraper element should follow the vertical movement of the sealing element. The scraper element can be fastened pivotably in the working direction to the rear side of the at least one sealing element. A particular embodiment is provided such that the scraper element is designed as a plate pivotably fastened to the sealing element.

[0024] The measuring device for measuring the angle between at least one sealing element and at least one scraper element can have at least one angle sensor to be able to measure the angle directly. However, the measuring device can also have other sensors that do not measure the angle directly but detect variables that are related to the angle.

[0025] Another embodiment provides a linear drive system for adjusting at least one scraper element, which system acts on the at least one scraper element so that when it is actuated, the lower scraping edge of the scraper element is raised or lowered relative to the sealing element, wherein it can apply a predetermined contact force.

[0026] For controlling the linear drive system, a control device can be provided which is configured such that the lower scraping edge of the at least one scraper element rests on the milled material with a predetermined contact force.

[0027] One embodiment of the linear drive system provides at least one piston / cylinder arrangement, the piston acting on at least one sealing element and the cylinder acting on at least one scraper element, or the piston acting on at least one scraper element and the cylinder acting on at least one sealing element. This embodiment has the advantage that the angle between the scraper element and the sealing element can be easily detected via the stroke position of the piston of the piston / cylinder arrangement. In this embodiment, the measuring device can have at least one position sensor for measuring the stroke position of the piston of the piston / cylinder arrangement.

[0028] The linear drive system not only allows the desired contact pressure to be applied, but also allows the height of the scraper element to be adjusted. The control device for controlling the linear drive system can be configured so that an operating mode can be set in which the scraper element is folded up. Two operating modes can also be provided, wherein the control device is configured so that in one operating mode the scraper element is only partially folded up, for example in a horizontal position, or completely folded up.

[0029] The required pressure of the scraper elements can also be applied by a spring which acts on at least one scraper element and also on at least one sealing element.

[0030] The method according to the invention relates to the operation of a self-propelled construction machine, in particular a road milling machine, a regenerator or a stabilizer, the self-propelled construction machine having a machine frame and a milling drum, the milling drum being arranged in a milling drum housing, which has a sealing device having at least one sealing element, which is arranged behind the milling drum in the working direction of the construction machine for closing the milling drum housing. The method according to the invention is provided for determining the pivot position of at least one scraper element, which is pivotably arranged on at least one sealing element, so that at least one scraper element rests on the milled material in one operating mode of the construction machine, so that when the construction machine advances, the scraper element is pulled through the milled material and pivots relative to the milling drum based on the height of the milled material. The height position of the at least one sealing element is adjusted based on the pivot position of the at least one scraper element, so that when the construction machine advances, the pivot position of the scraper element is within a predetermined pivot range. In this case, the at least one sealing element can be pressed against the ground with a predetermined contact force. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] An embodiment of the present invention is described in more detail below with reference to the accompanying drawings, in which:

[0032] Figure 1 is a side view of a self-propelled construction machine according to the present invention;

[0033] Figure 2A is a partial view of a milling drum housing of a self-propelled construction machine according to the invention, the milling drum housing having a sealing device, wherein the sealing element moves upwards;

[0034] Figure 2B is a partial view of a milling drum housing of a self-propelled construction machine according to the invention, the milling drum housing having a sealing device, wherein the sealing element moves downwards;

[0035] Figure 3A simplified schematic diagram shows a sealing element and a scraper element of a sealing device and a control device for controlling an adjustment device for adjusting the height of the sealing element, wherein the scraper element is in the correct angular position;

[0036] Figure 4 A hydraulic circuit diagram showing a control device for controlling a linear drive system of a scraper element of a sealing device;

[0037] Figure 5 is a plan view of an embodiment of a scraper element of a sealing device;

[0038] Fig. 6A shows the position of the sealing element and the scraper element in relation to the milling drum during advancement of the self-propelled construction machine without or partially loaded with material at time T1 , wherein the volume of milled material in the milling drum housing increases, thereby raising the scraper element;

[0039] Figure 6B shows the positions of the sealing element and the scraper element at time T2 after the sealing element is raised;

[0040] Fig. 7A shows the position of the sealing element and the scraper element at a time T1, wherein the volume of the milled material in the milling drum housing decreases, thereby lowering the scraper element;

[0041] Figure 7B shows the position of the sealing element and the scraper element at time T2 after the sealing element has been lowered;

[0042] Figure 8 The position of the sealing element and the scraper element is shown in the operating mode fully loaded with milled material;

[0043] Fig. 9 showing the position of the sealing element and the scraper element in an operating mode in which the sealing element is in a partially raised position; and

[0044] Fig.10 The positions of the sealing element and the scraper element are shown in an operating mode in which the sealing element is in a fully raised position. DETAILED DESCRIPTION

[0045] Figure 1 The basic components of a road milling machine are shown as an example of a self-propelled construction machine. The road milling machine has a machine frame 1 and a chassis 2, which may include front and rear wheels or track drives. In the present embodiment, the road milling machine has left and right rear wheels and only one front wheel 3. However, the road milling machine may also have left and right front wheels.

[0046] Furthermore, the road milling machine has a milling drum 4, which is arranged in a milling drum housing 5 on the machine frame 1. In the present embodiment, the milling drum housing 5 is located at the rear of the machine.

[0047] In the present embodiment, the height of the machine frame 1 relative to the surface 7A of the ground 7 can only be adjusted by the rear piston / cylinder arrangement 6. The milling depth is adjusted by raising or lowering the machine frame 1 relative to the ground 7. However, the construction machine can also have a front piston / cylinder arrangement for adjusting the height of the machine frame assigned to the wheels or drives.

[0048] The milling track is denoted by reference numeral 7B and its surface is denoted by 7C. The milled material can be loaded onto a transport vehicle. For this purpose, the road milling machine has a transport device 8 with a conveyor belt 9, which transports the milled material from the milling drum housing 5 to the truck. If the milled material is not loaded, it lies in the milling track 7B on the surface 7C.

[0049] On the left and right side in the working direction 10, the milling drum housing 5 is closed by side panels 5A, 5B, wherein Figure 1 Only the side plate 5B on the right side in the working direction is visible. The sealing device 11 is located behind the milling drum 4 in the working direction 10.

[0050] Figure 2A and Figure 2B is a perspective view of a milling drum housing 5 with a sealing device 11. The sealing device 11 has a height-adjustable sealing element 12, by which the milling drum housing 5 can be closed at the rear. The plate-shaped sealing element 12 is guided in a transverse guide 14 in an inlet 13 on the machine frame 1. In this case, the sealing element 12 can be positioned at a slight angle relative to the ground. Instead of a single sealing element, a plurality of sealing elements can also be provided.

[0051] In order to adjust the height of the sealing element 12 , an adjusting device 16 is provided which has a piston / cylinder arrangement 15 , whose cylinder 15A is fixed in an articulated manner on the inlet 13 and whose piston 15B is fastened in an articulated manner to the sealing element 12 . Figure 2A The sealing element 12 is shown in a lowered position, while Figure 2B The sealing element 12 is shown in a raised position.

[0052] In order to control the adjustment device 16 for adjusting the height of the sealing element 12, in particular the piston / cylinder arrangement 15, a control device 17 is provided, which is configured so that the sealing element 12 can be raised or lowered. The control device 17 of the sealing element 12 can be a separate control device or part of a central control and computing unit of the construction machine.

[0053] The sealing device 11 also has a scraper element 18, which is fastened pivotably to the rear side of the sealing element 12 in the working direction 10. In the present embodiment, the scraper element 18 is designed as a substantially rectangular plate, which is connected in an articulated manner to the plate-like sealing element 12 on the upper part of the wide side, wherein the sealing element 12 can be pivoted about a rotation axis 4A ( Figure 3 ). The scraper element 18 preferably extends over the entire width of the milling drum 4, but can also extend over only part of the width of the milling drum. It is also possible for a plurality of scraper elements to be pivotably fastened to the sealing element. The lower part of the scraper element 18 forms a (horizontal) scraping edge 18A which extends parallel to the axis of rotation 4A of the milling drum 4 and rests on the surface 7D of the milled material 7E remaining in the milling track 7B.

[0054] In order to pivot the scraper element 18, a linear drive system 19 ( Figure 4 ), in the present embodiment, the linear drive system 19 comprises a piston / cylinder arrangement 20 which is arranged in a plane extending perpendicularly to the axis 4A of the milling drum 4. The upper end of the cylinder 20A of the piston / cylinder arrangement 20 is connected in an articulated manner to the rear side of the plate-like sealing element 12 via a first articulated joint 21, and the lower end of the piston 20B of the piston-cylinder arrangement 20 is connected in an articulated manner to the upper side of the plate-like scraper element 18 via a second articulated joint 22, so that the scraper element 18 can be lowered by extending the piston 20B and raised by retracting the piston 20B of the piston / cylinder arrangement 20.

[0055] In this embodiment, the scraper element 18 is a substantially rectangular metal plate, on the lower wide side and two narrow sides of which strips 18B, 18C, 18D (made of flexible material such as rubber wings) are fastened respectively. Figure 5 ). The lower material strip 18B forms the scraping edge 18A, while the transverse material strips 18C, 18D flexibly seal the scraper element 18 on both sides relative to the sides of the milling track 7B, so that the milling drum housing 5 is closed at the bottom. This flexible seal also prevents the scraper element 18 from being damaged under mechanical stress. The material strips 18B, 18C, 18D can be screwed onto the metal plate so that these strips can be replaced when worn.

[0056] In the present embodiment, the scraping edge 18A of the scraper element 18 is kept pressed against the ground with a predetermined contact force. When the construction machine advances, the milled material is thrown up in the form of a wall, which can have its maximum height in the middle of the milling track. The scraper element 18 scrapes over the ground with a predetermined contact force, smoothing the milled material, wherein the milled material moves to the side, so that the area under the scraper element is closed over the entire width of the milling track.

[0057] For controlling the linear drive system 19, a hydraulic control device 27 is preferably provided, wherein Figure 4 Only a part of its hydraulic system is shown. The control device 27 of the linear drive system 19 for pivoting the scraper element 18 and the control device 17 of the adjustment device 16 for adjusting the height of the sealing element 12 can be separate devices or form a common device, which can also be part of the central control unit of the construction machine at least to some extent.

[0058] Figure 4 A simplified hydraulic circuit diagram of a control device for a scraper element 18 is shown with a piston / cylinder arrangement 20 for raising or lowering the scraper element 18. During the forward movement of the construction machine, the scraper element 18 is in a floating position so that the scraper element rests on the milled material with a predetermined contact force. In the floating position, a hydraulic valve 23 (not shown in more detail) of the hydraulic unit connects the upper and lower cylinder chambers of the cylinder 20A of the piston / cylinder arrangement 20 to a hydraulic tank (not shown) via hydraulic lines 24, 25 connected to the cylinder connection, so that the system pressure is not applied to the cylinder chambers. The hydraulic valve 23 is a 4 / 3-way valve. For simplicity, the hydraulic lines leading to the valve are not shown. Since no specific hydraulic force acts on the cylinder 20A, the piston 20B can move in the cylinder so that the scraper element 18 pivots downward due to its weight. In the case of the same pressure in both cylinder chambers, this downward movement can be further supported by a corresponding design of the effective contact surface of the hydraulic cylinder if a pressure (preferably which does not correspond to the system pressure) is applied to both cylinder chambers in the floating position. By switching the hydraulic valve 23, the system pressure can be applied to one or the other hydraulic line 24, 25 (pressure line) or one or the other hydraulic line can be connected to the tank (tank line), so that the piston 20B moves upward or downward to pivot the scraper element 18. The contact pressure can be a contact pressure specified by the controller, which can preferably be adjusted by the machine operator within specified limits.

[0059] Instead of a piston / cylinder arrangement, the sealing device can also have a spring element for applying pressure, for example one or more compression springs, wherein one end of the spring is connected to the scraper element and the other end of the spring is connected to the sealing element.

[0060] The sealing device 11 also has a measuring device 26 for determining Figure 3The angle denoted by α in the figure and enclosed by the sealing element 12 and the scraper element 18. However, instead of the angle α, the angle β (β=180°-α) can also be defined, although the conditions are reversed. When the sealing element is folded up, α increases and β decreases. In order to determine the angle, the sealing device can have an angle sensor. Such a sensor is part of the prior art. However, in the present embodiment, the angle is measured with a position sensor 26A, which measures the path of retraction or extension of the piston 20B of the piston / cylinder arrangement 20. The position sensor 26A generates a measurement signal related to the angle α(β). Since the geometric conditions are known, the angle can be derived from the path. A position sensor for a piston / cylinder arrangement is part of the prior art. Using a position sensor instead of an angle sensor has the advantage that the position sensor 26A can be easily integrated into the piston / cylinder arrangement 20.

[0061] Construction machines provide different operating modes that can be specified by the machine operator. Figure 3 , Fig. 6A , Figure 6B , Fig. 7A as well as Figure 7B An operating mode of the construction machine is described in which the milled material is not transported away from the milling drum housing 5 by the transport device 8 and therefore remains in the milling track 7B or only some material is picked up therein. The machine operator can specify that in this operating mode the sealing element 12 does not scrape the surface of the milled ground with its lower edge.

[0062] Figure 3 The scraper element 18 is shown in a pivoted position that is most suitable for adjusting the height of the sealing element. The sealing element 12 is in a position in which its lower edge is slightly above the surface 7D of the milled material 7E, so that the material is not retained by the sealing element. The scraper element 18 is in a position in which its lower scraping edge 18A is located below the lower edge of the sealing element 12. Thus, the milling drum housing 5 is sealed at the bottom and on the sides.

[0063] The scraper element 18 is inclined relative to the sealing element 12 so that no material jamming occurs in the milling drum housing 5. With increasing counterpressure due to material jamming, the scraping edge 18A of the scraper element 18 is raised, i.e. the scraper element pivots clockwise, and in the case of reduced counterpressure, the scraping edge 18A of the scraper element 18 is lowered, i.e. the scraper element pivots counterclockwise. Target angle α between scraper element and sealing element soll It should be between 10° and 80°, preferably greater than 45°, and particularly preferably greater than 60°. In the present embodiment, a target angle of 65° is assumed, wherein if the angle α is greater than 68°, the scraper element 18 will be raised, and if the angle α is less than 62°, the scraper element 18 will be lowered. Target angle α sollPreferably, it is a preset angle, or target angle α, which cannot be changed by the machine operator. soll Can only be changed by the machine operator within specified limits.

[0064] The control device 27 of the linear drive system 19 for pivoting the scraper element 18 and / or the control device 17 of the regulating device 16 can include analog or digital circuits and can be a separate device or part of a central computing and control device of the construction machine. For example, the data or signal processing device can have a general-purpose processor, a digital signal processor (DSP) for continuous processing of digital signals, a microprocessor, an application-specific integrated circuit (ASIC), an integrated circuit composed of logic elements (FPGA) or other integrated circuits (IC) or a hardware component. The data processing program (software) can run on the hardware component. Combinations of different components are also possible.

[0065] The control device 17 of the adjustment device 16 is configured to move the sealing element 12 such that the angle α lies within a desired pivoting range.

[0066] Fig. 6A The situation is shown in which material accumulates in the milling drum housing, for example due to changes in milling parameters, so that the pressure of the material on the sealing element 12 and the scraper element 18 increases. As a result, the scraper element 18 is raised, so that the angle α increases. This change in angle is detected by the measuring device 26. If the angle increases, the control device 17 actuates the piston / cylinder arrangement 15 so that the sealing element 12 is raised. However, in the present embodiment, the sealing element 12 is not raised until the angle α is greater than an upper limit value.

[0067] When the sealing element 12 is raised, the pressure of the material on the sealing element 12 and the scraper element 18 is reduced again, so that the scraper element 18 is lowered again ( Figure 6B ). This angular change is detected by the measuring device 26. If the angle decreases, the control device 17 actuates the piston / cylinder arrangement 15, thereby lowering the sealing element 12. When the scraper element 18 has reached a predetermined lower limit value, in particular at a predetermined target angle α, the scraper element 18 remains at the current height position, so that the drum shell is still sealed and prevented from clogging by material.

[0068] Fig. 7A The opposite situation is shown, in which the volume of the material accumulated in the milling drum housing decreases, so that the pressure of the material decreases. As a result, the scraper element 18 is lowered, so that the angle α decreases. This angle change is detected by the measuring device 26. If the angle decreases, the control device 17 actuates the piston / cylinder arrangement 15, so that the sealing element 12 is lowered.

[0069] The control device 27 of the linear drive system 19 can also be configured so that the machine operator can specify other operating modes. For example, the machine operator can select these operating modes on an input unit.

[0070] Figure 8 The situation of full material loading is shown. If the milled material is to be completely transported away, i.e. not to remain in the milling track, the sealing element 12 is moved downwards in order to scrape the ground when the machine is advanced. The sealing element 12 thus seals the milling drum housing towards the rear. In this operating mode, the sealing element 12 also serves as a scraper element. For this operating mode, the scraper element 18 is pivoted upwards as far as possible by means of the piston / cylinder arrangement 20 so that it does not get stuck in the milling track during the steering movement ( Figure 8 ).

[0071] Fig. 9 The operating mode of the shunting movement is shown. For shunting, the scraper element is pivoted by means of the piston / cylinder arrangement 20 into a position at an angle α of 90°.

[0072] Fig.10 The operating mode is shown in the maintenance position, for example, for changing the chisel of the milling drum. For maintenance, the sealing element 12 is fully raised, wherein the piston 15B of the piston / cylinder arrangement 15 is fully retracted by the control device 17. The scraper element 18 is pivoted upwards as far as possible, wherein the piston 20B of the piston / cylinder arrangement 20 is fully retracted.

[0073] Furthermore, the scraper element 18 can also be controlled manually by the machine operator by actuating an operating element.

Claims

1. A self-propelled construction machine, comprising a machine frame (1), a milling drum (4), an adjusting device (16) and a first control device (17), wherein the milling drum (4) is arranged in a milling drum housing (5), the milling drum housing (5) having a sealing device (11), the sealing device (11) having at least one sealing element (12), the sealing element (12) being arranged behind the milling drum (4) in the working direction of the construction machine for closing the milling drum housing (5), the adjusting device (16) being used for adjusting the height position of the sealing element (12) relative to the milling drum (4), and the first control device (17) being used for controlling the adjusting device (16) of the at least one sealing element (12); Features: The sealing device (11) has at least one scraper element (18) which is pivotably arranged on at least one sealing element (12) so that the at least one scraper element (18) rests on the milled material (7E) in an operating mode of the construction machine, so that the scraper element (18) is pulled through the milled material as the construction machine advances and pivots relative to the milling drum (4) based on the height of the milled material (7E); in A measuring device (26) is provided for determining the pivot position of at least one scraper element (18), which generates a measuring signal which is correlated with the pivot position and is received by a first control device (17) of an adjustment device (16) of at least one sealing element (12); A first control device (17) of an adjusting device (16) of at least one sealing element (12) is configured so that the adjusting device (16) adjusts the height position of at least one sealing element (12) based on the pivot position of the scraper element (18), so that the pivot position of the scraper element (18) is within a predetermined pivot range.

2. The self-propelled construction machine according to claim 1, characterized in that: The first control device (17) of the adjustment device (16) of the at least one sealing element (12) is configured so that the adjustment device (16) raises the at least one sealing element (12) when the scraper element (18) pivots upwards and lowers the sealing element (12) when the scraper element (18) pivots downwards.

3. The self-propelled construction machine according to claim 1, characterized in that: The first control device (17) of the adjusting device (16) of the at least one sealing element (12) is configured such that when the angle (α) between the scraper element (18) and the sealing element (12) is set to be greater than an upper limit value, the adjusting device (16) raises the at least one sealing element (12), and when the angle (α) between the scraper element (18) and the sealing element (12) is set to be less than a lower limit value, the sealing element (12) is lowered.

4. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that: The upper portion of the at least one scraper element (18) is fastened to the sealing element (12) such that it can pivot about an axis extending parallel to the axis of rotation (4A) of the milling drum (4).

5. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that: The at least one scraper element (18) is fastened pivotably in the working direction (10) to the rear side of the at least one sealing element (12).

6. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that: The at least one scraper element (18) is designed as a plate which is pivotably fastened to the at least one sealing element (12).

7. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that: The measuring device (26) has at least one angle sensor for measuring the angle between at least one sealing element (12) and at least one scraper element (18).

8. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that: A linear drive system (19) is provided which acts on the at least one scraper element (18) such that when it is actuated, the lower scraping edge (18A) of the scraper element (18) is raised or lowered relative to the sealing element (12).

9. The self-propelled construction machine according to claim 8, characterized in that A second control device (27) is provided for controlling the linear drive system (19), the second control device (27) being configured so that a lower scraping edge (18A) of at least one scraper element (18) rests on the ground with a predetermined contact force.

10. The self-propelled construction machine according to claim 8, characterized in that The linear drive system (19) has at least one piston / cylinder arrangement (20), whose piston (20B) acts on at least one sealing element (12) and whose cylinder (20A) acts on at least one scraper element (18), or whose piston (20B) acts on at least one scraper element (18) and whose cylinder (20A) acts on at least one sealing element (12).

11. The self-propelled construction machine according to claim 10, characterized in that The measuring device (26) has at least one position sensor (26A) for measuring the stroke position of a piston (20B) of a piston / cylinder arrangement (20).

12. The self-propelled construction machine according to any one of claims 1 to 3, characterized in that A spring is provided which acts on at least one scraper element (18) and also on at least one sealing element (12).

13. The self-propelled construction machine according to claim 9, characterized in that The second control device (27) for controlling the linear drive system (19) is configured such that an operating mode can be set in which the scraper element (18) is folded up.

14. The self-propelled construction machine according to claim 1, characterized in that The self-propelled construction machine is a road milling machine, a reclaimer or a stabilizing machine.

15. Method for operating a self-propelled construction machine, the self-propelled construction machine having a machine frame (1) and a milling drum (4), the milling drum (4) being arranged in a milling drum housing (5), the milling drum housing (5) having a sealing device (11), the sealing device (11) having at least one sealing element (12), the sealing element (12) being arranged behind the milling drum (4) in the working direction of the construction machine for closing the milling drum housing (5); Features: The pivot position of at least one scraper element (18) is determined, and the scraper element (18) can be pivotally arranged on at least one sealing element (12), so that the at least one scraper element (18) rests on the milled material (7E) in an operating mode of the construction machine, so that when the construction machine moves forward, the scraper element (18) is pulled through the milled material and pivots relative to the milling drum (4) based on the height of the milled material, wherein the height position of at least one sealing element (12) is adjusted based on the pivot position of the scraper element (18), so that when the construction machine moves forward, the pivot position of the scraper element (18) is within a predetermined rotation range.

16. The method according to claim 15, characterized in that During the advancement of the construction machine, when at least one scraper element (18) is raised, at least one sealing element (12) is raised, and during the advancement of the construction machine, when at least one scraper element (18) is lowered, at least one sealing element (12) is lowered.

17. The method according to claim 15, characterized in that When the angle (α) between the scraper element (18) and the sealing element (12) is set to be greater than an upper limit value during the advancement of the construction machine, at least one sealing element (12) is raised, and when the angle between the scraper element (18) and the sealing element (12) is set to be less than a lower limit value during the advancement of the construction machine, at least one sealing element (12) is lowered.

18. The method according to any one of claims 15 to 17, characterized in that At least one scraper element (18) is pressed onto the ground surface (7) with a predetermined contact force.

19. The method according to any one of claims 15 to 17, characterized in that An operating mode is set in which at least one scraper element (18) is folded up.

20. The method according to claim 15, characterized in that The self-propelled construction machine is a road milling machine, a reclaimer or a stabilizing machine.

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