Operating unit for controlling a levelling system

Abstract

An operating unit 21 for controlling a levelling system of a road finisher or asphalt milling machine comprises at least one variable optical signal device 29, 30 for displaying the status of the oper

Description

The invention relates to an operating unit for controlling a levelling system of a road building machine, in particular of a road finisher or a road miller, according to the preamble of claim 1. Road building machines, such as road finishers, are used for processing road surfaces consisting of asphalt and other road building materials, such as concrete or gravel. Road finishers of this kind are designed so as to be self-driving. For this purpose, they comprise a chassis, which may be a crawler chassis or a wheeled chassis. Viewed in the installation direction, road finishers comprise at least one front storage container for receiving the road building material. The asphalt material is transported from the storage container, by means of a conveyor, under a platform comprising a control platform, to a rear auger which distributes the road building material over the working width of the road finisher, in front of at least one screed. In order to produce the road surface, the screed is drawn over the road building material in a floating manner. The spacing between the screed and a substrate, i.e. the layer thickness of the road surface, is adjusted or levelled in by means of hydraulic cylinders or lifting cylinders. In this case, said cylinders engage on a left-hand and right-hand support arm in each case, viewed in the production direction, at the rear end of which the screed is fastened. Road millers comprise, in addition to a chassis, inter alia a milling drum which is moved over the road surface to be removed. The road building material removed by the milling drum or by the milling cutter is discharged by means of a conveyor. The milling depth or the levelling in of the milling drum is adjusted by the height of a milling box above the substrate. This is typically achieved by means of hydraulic drives. The control of a levelling system or of the hydraulic cylinders or of the different drives for adjusting the layer thickness or the milling depth is typically performed by an operator, who is located on a control platform of the road building machine. However, operating units are also known by means of which the above-mentioned components of the road building machine or of the hydraulic cylinders or of the drives can be controlled away from the control platform. In the case of the known operating units, it is found to be disadvantageous that these do not provide the operator with any direct display relating to the operating status of the components or of the hydraulic cylinders or of the drives of the levelling system. However, since difficult viewing conditions may often arise, in particular due to environmental conditions and a very wide range of weather conditions on the construction site, it is extremely essential that the operating status of the components should also be able to be read, directly and in an easily understandable manner, away from the control platform or the operating units. The operating status is understood to mean, for example, the height of the screed above the substrate, or the spacing of the milling box above a substrate, or particular angular positions of the cited components with respect to a predetermined reference. The movement status, i.e. screed moves up or down, and system errors, are also to be understood under the operating status. The object of the invention is therefore that of providing an operating unit for a road building machine, by means of which at least one operating status of a component of a road building machine can be read out particularly easily and reliably. An operating unit for solving this problem comprises the features of claim 1. According thereto, it is provided for the operating unit for controlling a levelling system of a road building machine to comprise at least one adjustable optical signal means. Said at least one signal means makes it possible for a status of hydraulic cylinders and / or drives and / or a component, which may for example be a screed or a milling box, to be displayed. The status or the operating status may be a cylinder position, a setting or orientation of a drive, a spacing or an angular position of the screed or of the milling box relative to a substrate, or the like. It is similarly conceivable that said status may be a display of the energy supply of the mentioned components. Said optical signal means makes it possible for the status of the mentioned components to be identified not only far from the road building machine, but also at a small distance from the operating unit, also in the case of adverse ambient or weather conditions. As a result, the operation, as well as the control of the components, is greatly simplified. Furthermore, a particularly preferred embodiment of the present invention consists in the at least one signal means being designed as coloured strips. The colouring of the strip makes it possible to establish a particularly sharp contrast with respect to the surroundings. In particular in the case of the previous two-colour displays, sufficient contrast for being able to reliably identify information even in poor lighting conditions is often lacking. In this case, it is explicitly noted that the coloured strips of the operating unit may be of different colours. The different colourings make it possible for different situations or statuses to be displaced in an easily and quickly identifiable manner. The invention preferably provides for the strip to be formed by a plurality of illuminants, preferably LEDs, which are arranged inside a housing of the operating unit, the housing comprising a strip-like recess, behind which the illuminants are positioned. The optical signal is generated by the illuminants shining through the strip or through the slit-like recesses. The recesses can for example be filled by a transparent material, or be covered by a corresponding transparent film. As a result, the operating unit also achieves the mechanically necessary robustness, which is necessary on a construction site. Furthermore, it is possible for a homogeneous appearance to be achieved by means of an at least slight opacification of the transparent material, for example. It is preferably provided for a plurality of, i.e. 5, 10, 50, 100, 200 or more, LEDs, preferably different coloured LEDs, to be arranged in a row, such that they exactly coincide with the strip-like recess of the housing. It is thus possible for the width of the strip to comprise exactly one LED or one pixel for example, while the length of the strip comprises a plurality of LEDs arranged close together. This high packing density of the LEDs not only ensures a homogeneous colouring, but also sufficient intensity of the signal. LEDs are particularly suitable, because they are very long-lasting and at the same time consume only very little energy. Furthermore, LEDs are available in a plurality of different colours. It is in particular provided for the plurality of illuminants, for generating signals of one colour and / or for generating signals of different colours, to comprise different colours. The actuation of illuminants of the same colour makes it possible to generate a particularly strong optical signal. Changing the signal from for example red to green makes it possible for different statuses to be displayed. A colour change makes it possible, for example, for a warning or an important indication to be signalled. Ultimately, it can be provided for the operating unit to store customer-specific optical signals, and for a very wide range of data and information to be able to be visually displayed, depending on the application. A particularly preferred embodiment provides for the illuminants, preferably uniformly or of different colours, to be able to be automatically switched on and off at different frequencies, and / or for different, preferably constant, signal patterns to be able to be generated by means of successively switching on and off individual illuminants. In particular the possibility of such signal patterns makes it possible for a plurality of different signals to be generated. It is also conceivable for the operating unit to comprise exactly two strips, which are arranged to the left and right, on the operating unit. In this case, the illuminants of the two strips are actuatable and / or switchable independently of one another. It is conceivable for information relating to a left-hand part of the components and relating to a right-hand part of the components to be able to be displayed for a user by means of the different actuation, and specifically such that said information can be read out quickly and easily, even in poor viewing conditions. Finally, an essential aspect of the invention can consist in the status of the at least one hydraulic cylinder and / or of the at least one further drive, which is associated with a lefthand side of the road building machine viewed in the direction of travel of the road building machine, being able to be displayed, by means of a first signal means arranged on the left-hand side, on the operating unit. The status of the at least one hydraulic cylinder and / or of the at least one further drive, which is associated with a right-hand side of the road building machine viewed in the direction of travel of the road building machine, can be displayed, by means of a second signal means arranged on the right-hand side, on the operating unit. This association of the left-hand signal means with a left-hand hydraulic cylinder or a left-hand part of the screed makes it possible for the control of the screed to be designed in a particularly intuitive manner. It is directly clear to the user, by way of this optical signalling, what the condition of the left-hand half of the screed is. The same of course also applies for the right-hand half of the road building machine and a right-hand signal means of the operating unit. In particular the intuitive read-out of the operating unit by the optical signals creates an operating unit which is particularly easy and reliable to use. Finally it can furthermore be provided that the current length of the left-hand and / or righthand hydraulic or levelling cylinder, and, preferably at least indirectly, a material layer thickness, can be displayed by the first and second signal means. It is thus possible for a statement relating to the layer thickness of the road surface to be displayed, for example by the length or the height of the strip. A completely green strip can for example mean that the layer thickness corresponds to the target value. For this purpose, the invention provides for both the road thickness and the length of the lifting cylinder to be measured by corresponding sensors. Similarly, a green strip can mean that the minimum layer thickness is achieved. A half red right-hand strip could for example mean that the actual value of the layer thickness of a right-hand half of the screed does not correspond to the target value. The layer thickness can be adjusted in a simple manner, by operation of the corresponding operating elements of the operating unit. In this case, an operating element is actuated until the strip is entirely green. It is explicitly noted that this constitutes just one of several possible embodiments. A particularly preferred embodiment of the invention can provide for the current length of the left-hand and / or right-hand hydraulic or levelling cylinder, and, preferably at least indirectly, a material layer thickness, to be able to be displayed by the first and the second signal means. Other or current operating modes of further components of the road building machine can also be optically displayed in this way, by the signal means. The operating unit allows for different components to be associated with the signal means, among which components the operator can select. This association can be selected either by operating the operating elements or by voice input. In this way, the operating unit claimed here can be used in a versatile and also flexible manner. Similarly, it can furthermore be provided for the operating unit to also be able to be used for other road building vehicles not mentioned here. It is furthermore conceivable for the operating unit to be designed as a wired or wireless remote controller. In particular the embodiment comprising a wireless operating unit is particularly advantageous, because the operator can move freely around the road building machine, without being bound by a finite length of a cable. Similarly, a wired operating unit can also prove to be particularly advantageous, because in this case sufficient signal and energy transfer between the road building machine and the operating unit is always ensured. Finally it is conceivable for the strip-like signal means to be able to be used as indicators, in order to perform and monitor the levelling of the components, in particular of the screed or of the milling box, by means of the operating elements. The operator obtains direct and unambiguous feedback relating to the current state of the components via the signal means. This “in situ” display of the operating status makes it possible for all the components to be actuated and controlled in a particularly simple and reliable manner. A preferred embodiment of the invention will be explained in the following, with reference to the drawings, in which: Fig. 1 is a schematic side view of a road finisher, and Fig. 2 is a schematic view of an operating unit. In order to illustrate the invention described here, Fig. 1 shows a road finisher 10 as an example for a road building machine. However, the invention is likewise used in combination with other road building machines, such as a road miller. Therefore, the invention is not restricted to the road finisher 10, described here by way of example, but rather is also applicable to further road building machines. Road finishers 10 are used for producing road surfaces. These may be road surfaces of any kind. The road finisher 10 show in Fig. 1 is designed so as to be self-driving. For this purpose, it comprises a central drive unit 11, which comprises an internal combustion engine for example, which drives hydraulic pumps for supplying hydraulic motors, and optionally a generator for generating energy for electrical drives. The road finisher 10 comprises a chassis 12 which, in the embodiment shown, is designed as a wheeled chassis, but which can also be designed as a crawler chassis or another chassis or running gear. The chassis 12 shown in Fig. 1 comprises two drive wheels 13 and four steerable wheels 14. The drive wheels 13 are driven by the drive unit 11 such that the road finisher 10 can be moved forwards in the production direction 15. Viewed in the production direction 15, a tub-like or trough-like storage container 16 is arranged in front of the drive unit 11. The storage container 16 receives a supply of the material used for manufacturing the road surface, for example asphalt. It is optionally also possible for a plurality of storage containers to be provided. The road building material is transported from the storage container 16, under the drive unit 11, to the rear end of the road finisher 10, viewed in the production direction 15, by means of conveying members (not shown). The road building material is distributed over the entire working width of the road finisher 10 by means of an auger 17 arranged behind the chassis 12. In this case, a supply of the road building material arrives in front of a screed 18 which is attached behind the auger 17 and the chassis 12 and can be moved up and down. The screed 18 is suspended on a right-hand and a left-hand support arm 31, which are in turn connected to the road finisher 10 by means of levelling cylinders 32 and lifting cylinders 33. The height of the screed 18, and thus the layer thickness, can be changed by actuating the levelling cylinders 32. A direct statement relating to the status of the screed 18 and / or the size of the layer thickness can be derived from the lifting position of the cylinders 32, 33. The road finisher 10 is controlled, from a control platform 19, by an operator (not shown). Said control platform 19 can be designed as a closed or open cab. In this case, the control platform comprises at least one, preferably two, driver’s seats 20 which are arranged side-by-side when viewed in the production direction 15 or in the direction of travel. These driver’s seats 20 are optionally movable at least slightly transversely to the production direction 15, in order that the operator can move into an optimal position, during operation of the road finisher 10, in order to monitor, and thus control, the production process. For the operation of the road finisher 10 or a component, such as the screed 18, the road finisher 10 is associated with the operating unit 21 according to the invention (Fig. 2). Said operating unit 21 can be designed as a wireless or wired remote controller. A housing 22 of the operating unit 21 is dimensioned such that it can be held and operated, by an operator, using one hand or both hands. A cuboid-like shape is preferably provided, an upper part 25, which can be associated with a display 23, preferably being slightly angled in order to simplify the readout of information which is shown on the display 23. An embodiment can furthermore provide for the display 23 to be mounted in the housing 22 so as to be pivotable about an axis, in order to be able to set an optimal viewing condition depending on the viewing position or the position of the sun. A lower part 26 of the operating unit 21 comprises a plurality of different operating elements 24. These operating elements 24 can be buttons, switches, rocker switches, rotary knobs, or the like. It is furthermore conceivable for the housing 22 to be associated with capacitively acting operating elements 24. At least virtually all the components of the road finisher 10, such as the screed 18, the auger 17, but also components of other road building vehicles, provided the operating unit 21 is connected thereto, can be operated or controlled by means of said operating elements 24. All the cylinders, as well as other drives of said components, can be actuated by means of said operating elements 24. It is then possible to call up and / or display on the display 23 all the information, in conjunction with the components. The operating unit 21 can communicate directly with the road building vehicle by means of an interface. That is to say that all the inputs or information, which can be performed or read out from the control platform 19, can also be performed or read out via the operating unit 21. All the signals between the operating unit 21 and the road finisher 10 can be exchanged via a cable or by radio. In the embodiment of a wired operating unit 21, this can also be supplied with energy via the cable. The wireless version of the operating unit 21 comprises an accumulator which can be charged for example at a charging station on the road finisher 10. In the embodiment of the operating unit 21 shown in Fig. 2, a right-hand region 27 and a left-hand region 28 of the lower part 26 comprises a right-hand signal means 29 and a lefthand signal means 30. Said signal means 29, 30 are formed in a strip-like manner, longitudinal axes of the strip-like signal means 29, 30 being oriented so as to be in parallel with a longitudinal axis of the operating unit 21. It may be possible for the housing 22 to be formed so as to be transparent in the region of the strip-like signal means 29, 30. In this case, two strip-like apertures in the housing 22 can be covered by a transparent film or a transparent material. Illuminants are positioned in the housing 22 or directly behind the strip-like apertures or recesses. Said illuminants can for example be LEDs. In this case, the LEDs are strip-like, i.e. arranged closely side-by-side under the recesses, such the signal means 29, 30 are formed. According to the invention, said illuminants are designed so as to be different colours and are actuatable independently of one another. For example, too small a left-hand installation thickness of the surface can be displayed by a red half strip of the left-hand signal means 30, while a right-hand green strip of the signal means 29 can show that the current layer of the right-hand half of the screed 18 correspond to the target value. Similarly, it is conceivable that flashing or a colour gradient may be able to be displayed by the illuminants, such that a particular event or a particular situation can be indicated by the signals 29, 30, or a temporally variable process can be illustrated. It is thus possible, for example, to directly display the length of the hydraulic cylinders for the screed 18 by means of the length of the strip-like signal means 29, 30. The status of particular components can be directly changed by means of the operation of the operating elements 24. As a result of this change in the status of the components, the appearance of the signal means 29, 30 also changes at the same time, such that the operator receives direct feedback relating to their control commands. The invention provides for a plurality of different states or statuses of a very wide range of components, cylinders or other drives to be able to be displayed by the coloured signal means 29, 30. In this way, the operating unit 21 described here can be used, in a particularly flexible manner, for a very wide range of vehicles. List of reference signs: road finisher drive unit chassis drive wheel wheel direction of travel storage container auger screed control platform driver’s seat operating unit housing display operating element upper part lower part right-hand region left-hand region right-hand signal means left-hand signal means support arm levelling cylinder lifting cylinder 03 10 25

Claims

1. Operating unit (21) for controlling a levelling system of a road building machine, in particular of a road finisher (10) or an asphalt milling machine, comprising actuating hydraulic levelling cylinders (32), for levelling a screed (18), said operating unit (21) comprising:5 operating elements (24) for actuating said hydraulic levelling cylinders (32), andat least one variable optical signal means (29, 30) for displaying a status of the hydraulic levelling cylinders (32), characterised in that the at least one variable optical signal means (29, 30) comprise first and second signal means (29, 30) which are formed as strips, LEDs of the two strips 10 being actuatable or switchable independently of one another to display the current length of a left-hand hydraulic levelling cylinder (32), which is associated with a left-hand side of the road building machine viewed in the direction of travel (15) of the road building machine, and a right hand hydraulic levelling cylinder (32), which is associated with a right-hand side of the road building machine viewed in the direction of travel (15) of the 15 road building machine, by the first and second signal means (29, 30) respectively, and with that at least indirectly displaying a material layer thickness, wherein each strip is formed by a plurality of LEDs, which are arranged inside a housing (22) of the operating unit (21), the housing comprising a strip-like recess, behind which the LEDs are positioned, wherein each of the signal means (29,30) is designed as a coloured strip and20 wherein the plurality of LEDs comprise at least one colour for generating signals of at least one colour, and wherein:the plurality of LEDs can be automatically switched on and off at different frequencies;different signal patterns can be generated by means of successively switching on 25 and off individual LEDs; andthe status of the left hand hydraulic levelling cylinder (32) can be displayed, by means of a first signal means (30) arranged on the left-hand side, on the operating unit (21), and the status of the right hand hydraulic levelling cylinders (32) can be displayed, by means of a second signal means (29) arranged on the right-hand side, on the30 operating unit (21).

2. Operating unit (21) according to claim 1, characterised in that the plurality of LEDs comprise different colours for generating signals of one colour.LO CXI3. Operating unit (21) according to claim 1, characterised in that the plurality of LEDs comprise different colours for generating signals of different colours.

4. Operating unit (21) according to any preceding claim, in which the different signal 5 patterns are constant.

5. Operating unit (21) according to any of the preceding claims, characterised in that the operating unit (21) is designed as a wired or wireless remote controller.10

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