Mobile working machine and method for operating a mobile working machine

Abstract

Mobile working machine (100) with a substructure (10) supporting a working boom (14), which has a chassis with at least two wheel axles (31, 32) and wheels (30) arranged thereon, a support device (20, 22) arranged on the substructure (10) which can be supported on a surface (28) when the working machine (100) is raised, and a measuring sensor system (50, 60) for determining a wheel load acting on the wheels (30) of the at least two wheel axles (31, 32), as well as a computing unit (42) for performing a stability calculation, wherein the stability calculation includes a residual wheel load acting on at least one wheel (30) of a wheel axle (31, 32) when the working machine (100) is not fully raised.

Description

Technical field

[0001] The present invention relates to a mobile working machine and a method for operating a mobile working machine. Description of the state of the art

[0002] Mobile work machines, such as mobile concrete pumps, must be positioned stably on the ground at the work site or construction site. This is achieved using outriggers (extendable support arms), which improve the stability of the machine at the work site. The outriggers are positioned as far away from the vehicle's center of gravity as possible, ensuring the most rigid setup possible (without using the vehicle's suspension). The less load remains on the sprung axles, the more stable the machine. Fully extending the wheels thus maximizes the reach of the boom. Such work machines are known, for example, from DE 198 05 359 A1 and EP 3 091 143 A1.

[0003] On the other hand, particularly in the case of mobile concrete pumps, it can be advantageous to have the rear axle resting on the ground to prevent vibrations. On sloping terrain, it can also be beneficial to leave at least one axle on the ground or not to fully excavate it. In practice, this can be managed by measuring the axle's excavation depth and considering an axle as excavated once a certain threshold is reached. Below this threshold, the system cannot operate properly, while above it, full operation is possible. Summary of the invention

[0004] Based on this, a mobile working machine with the features of claim 1 and a method with the features of claim 5 are proposed according to the invention. Furthermore, a computer program with the features of claim 9 and a control device for a mobile working machine with the features of claim 10 are proposed according to the invention.

[0005] The invention is based on the finding of a flexible adjustment of the reach of a working boom of a mobile work machine, taking into account a residual wheel load acting on at least one wheel when the work machine is not fully raised. Residual wheel load is understood to be the residual load acting on a wheel of an axle when the wheel (and thus also the axle) is not fully raised (as a value between the full load when no support is provided and the load-free state when fully raised).

[0006] Below is a numbered list of aspects of the invention: 1. A mobile work machine with a substructure supporting a working boom, comprising a chassis with at least two wheel axles and wheels arranged thereon, a support device arranged on the substructure that can be supported on a surface when the work machine is raised, and measuring sensors for determining a wheel load acting on the wheels of the at least two wheel axles, as well as a processing unit for performing a stability calculation, wherein the stability calculation includes a residual wheel load acting on at least one wheel of a wheel axle when the work machine is not fully raised. 2. A mobile work machine according to aspect 1, in which the measuring sensors are designed for directly measuring the residual wheel load and / or in which the measuring sensors are designed for measuring a force in the support device. 3.1. Mobile working machine according to aspect 1 or 2, where the residual wheel load at the time the working machine is supported is included in the stability calculation and / or where the residual wheel load is continuously included in the stability calculation during operation of the working boom. 2. Mobile working machine according to one of aspects 1 to 3, where a mass dependent on the residual wheel load is subtracted from a mass of the working machine or from a mass of the substructure in the stability calculation. 3. Mobile working machine according to aspect 4, where the position of at least one residual wheel load is additionally included in the calculation of the center of gravity position of the working machine or the substructure. 4. Mobile working machine according to one of aspects 1 to 5, where, if a residual wheel load is present, the result of an inclination monitoring is included as a further parameter in the stability calculation. 5.Mobile working machine according to aspect 6, in which the tilt monitoring comprises measuring and recording an initial tilt after support has been established and comparing a current tilt during operation of the working machine with the recorded initial tilt. 8. Method for operating a mobile working machine, in particular according to one of aspects 1 to 7, comprising, after providing a mobile working machine with at least two wheel axles and a support device on a surface and supporting the working machine on the surface by means of the support device, the following steps: determining a wheel load acting on at least one wheel of the two wheel axles, and performing a stability calculation taking into account a residual wheel load acting on at least one wheel of a wheel axle when the working machine is not fully raised. 9.Method according to aspect 8, in which the step of determining the wheel load acting on the at least one wheel comprises: measuring the residual wheel load directly at the wheel or wheel axle and / or deriving the residual wheel load from a force measured in the support device. 10. Method according to aspect 8 or 9, in which the stability calculation is performed at the time the working machine is supported and / or in which the stability calculation is performed continuously during the operation of a working boom. 11. Method according to one of aspects 8 to 10, in which the step of performing the stability calculation comprises subtracting a mass dependent on the residual wheel load from a mass of the working machine or from a mass of the substructure. 12.Method according to aspect 11, in which the execution step additionally includes the position of at least one residual wheel load in the calculation of the center of gravity position of the machine or the substructure. 13. Method according to one of aspects 8 to 12, in which, if a residual wheel load is present, the result of an inclination monitoring is included as a further parameter in the stability calculation. 14. Method according to aspect 13, comprising the step of measuring and recording an initial inclination after support has been provided and the step of preferably continuously measuring a current inclination during operation of the machine and comparing it with the recorded initial inclination. 15.16. Computer program with program code means to carry out all steps of a procedure according to any one of aspects 8 to 14, if the computer program is executed on a computer or a corresponding computing unit, in particular a control unit of a mobile working machine. 17. Computer program according to aspect 15, which is stored on a computer-readable data carrier. 18. Control unit for a mobile working machine, in particular according to any one of aspects 1 to 7, which is designed to carry out a procedure according to any one of aspects 8 to 14, or in which a computer program according to aspect 15 is stored suitable for execution.

[0007] Further advantages and embodiments of the invention will become apparent from the dependent claims, the description and the accompanying drawing.

[0008] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0009] The invention is schematically illustrated in the drawing using an exemplary embodiment and is described in detail below with reference to the drawing. Brief description of the drawing

[0010] Figures 1a and 1b The side view shows a two-axle truck-mounted concrete pump in driving position and in the raised position. Figure 2 shows, in a highly schematic and simplified side view, one of the representations of Figures 1a and 1b similar four-axle truck-mounted concrete pump in the excavated position. Figure 3 The truck-mounted concrete pump is shown. Figure 2 in a partially raised position with the front axles raised. Figure 4 The truck-mounted concrete pump is shown. Figure 3with the front support legs raised. Figure 5 The truck-mounted concrete pump is shown. Figure 2 in a supported, but not lifted, situation. Figure 6 shows the process of a method according to the invention as a block diagram. Figure 7 shows a refined representation of the block diagram of the Figure 6 . Detailed description

[0011] Identical and similar features depicted in the individual figures are designated with the same reference symbols.

[0012] The embodiment described below with reference to the drawing shows a mobile concrete pump 100 as the mobile work machine according to the invention. Of course, the invention can also be implemented with other mobile work machines.

[0013] The in Figure 1a in driving position and in Figure 1bThe mobile working machine or concrete pump 100 shown in the raised pumping position comprises a substructure 10, which in the illustrated embodiment is designed as a two-axle chassis with front axle 31 and rear axle 32 and wheels 30, as well as a working boom 14, for example in the form of a concrete placing boom 14 rotatably mounted on a mast support 12 near the front axle about a vertical axis.

[0014] Furthermore, the mobile concrete pump 100 includes a high-viscosity pump 16 with a rear-mounted material feed hopper 18 and a support device consisting of two front and two rear support legs 20, 22 as is known.

[0015] The support legs 20, 22 can each be supported on a surface or floor 28 by means of a downwardly extendable foot section 24, 26 by raising the chassis 10.

[0016] As from the Figures 1a and bAs can be seen, the wheels 30 of the rear axle 32 are suspended from the frame 36 of the chassis 10 by means of wheel springs 34, which can be pre-tensioned by the action of the wheel or axle load. In the illustrated embodiment, the wheel springs 34 are designed as layered leaf springs.

[0017] Each wheel 30 of the rear axle 32 can also be assigned a locking mechanism 38 in a manner known per se, with which the spring travel of the respective wheel spring 34 is limited before being raised into the pumping position. Figure 1b The locking mechanism 38 can be configured in such a way that it is automatically actuated in the locking direction when the foot section is extended and automatically in the releasing direction when the foot section is retracted.

[0018] Figure 2 shows one of the representations of Figure 1bA similar, but highly schematic and simplified, side view of a four-axle truck-mounted concrete pump 100 in the raised position. In this fully raised position, where none of the wheels 30 are in contact with the ground 28, a maximum load moment is possible during the extension of the boom 14. This is therefore a rigid setup without any remaining vehicle suspension.

[0019] Very often, however, the work machine 100 is only lifted by its front axle(s) 31 during operation on the construction site, while the rear axle(s) 32, although also supported, still maintain contact with the ground, as exemplified in Figure 3 is shown.

[0020] This "partial excavation" has the advantage that the hopper of the material feed container 18 can be more easily filled by a concrete mixer supplying the concrete to be processed, due to the lowered hopper edge, and also that vibrations introduced into the substructure 10 by the switching movement of the high-viscosity pump 16 can be effectively suppressed. With this partial excavation, unlike the fully excavated position of the Figure 2 - a partial vehicle suspension, combined with what is referred to as residual wheel load or residual axle load within the scope of the present invention.

[0021] However, in the case of the concrete pump not being fully excavated, according to the illustration of the Figure 3 With a large load moment and the associated load on the corresponding leg springs, the support legs facing away from the load moment (here the front support legs 20) may lift off.

[0022] This is due to the presentation of the Figure 4 This illustrates where, with the working boom 14 extended, the increased load on the rear support legs 22 and the wheels of the rear axle 32 causes the front support legs 20 to lift off the ground. This lifting increases the inclination of the machine and makes its support structure "softer" or more elastic, and therefore more susceptible to vibration and tipping.

[0023] Even when parking the machine on a slope, it can be advantageous in practice to leave at least part of the axles on the ground. Figure 5 shows a support variant in which all wheels 30 of both the front and rear axles 31, 32 still have contact with the ground (on level ground).

[0024] For this reason, a stability calculation is carried out according to the invention to plan for additional safety.

[0025] The invention provides measuring sensors 50, 60 for determining the wheel load acting on the wheels 30 of the wheel axles 31, 32. Naturally, the load measurement can also be performed as a measurement of the axle load acting on the wheel axle, thereby capturing the combined wheel loads of the wheels assigned to that axle. Therefore, when the following refers to measuring the residual wheel load, it should also be understood as measuring the residual axle load.

[0026] The measuring sensors to be provided can comprise, on the one hand, a measuring sensor 50 for directly measuring the residual wheel or axle load and / or, on the other hand, a measuring sensor 60 for measuring a force in the support legs 20, 22. In the schematic representations of the Figures 2 to 5 The measuring sensors 50, 60 are represented as rectangles assigned to the wheels or wheel axles or the support legs.

[0027] The measuring sensor system 50 for directly measuring the residual wheel load can include, for example, sensors for measuring wheel or axle suspension travel, force transducers, strain gauges, etc. The measuring sensor system 60 for measuring a force in the support device can include, for example, strain gauges, force transducers, pressure sensors in the support cylinder, etc.

[0028] The measurement can be carried out, for example, via the vehicle suspension, alternatively, it can also be carried out using a separately provided spring installed in the force flow, or via the pressure in the hydraulic or pneumatic suspension.

[0029] The force in the support device could be measured using force sensors, pressure measurements, spring travel measurements, or deformation measurements. The total wheel load is then calculated as the minimum total load minus the sum of the support loads.

[0030] The invention is based on the consideration of taking into account the residual axle load acting on at least one wheel axle in the stability calculation of a work machine that is not fully raised.

[0031] This is done, for example, by subtracting mass (corresponding to the residual wheel or axle load) from the machine 100 or its undercarriage 10. Alternatively, this can also be done by adding a general (predefined) safety factor. For example, depending on the size of the residual axle load, a general value could be added to the distance of the machine's center of gravity from the tipping edge, such as an additional general distance of 1000 mm from the tipping edge for residual axle loads above 50%, and 1500 mm for a residual axle load of 75%.

[0032] Preferably, the subtraction takes place at the point where the affected wheel axle is located.

[0033] According to the invention, the wheel or axle load, referred to as residual wheel load or residual axle load, and its position are subtracted from the working machine 100 or the substructure 10, and preferably from its center of gravity position, resulting in a new working machine or substructure weight and a new center of gravity position. The reduced machine or substructure mass resulting from the subtraction of the corresponding residual load is associated with a reduced reach of the working boom.

[0034] Furthermore, it is possible to consider the position of the contact point between the wheel in question and the ground, i.e., to subtract the mass of the wheel loads (at least partially) from the total mass used in the stability calculation, so that the corrected mass is the total machine mass minus the sum of the wheel loads (Corrected Mass = Total Machine Mass - Sum of Wheel Loads). The corrected center of gravity vector would then be the center of gravity vector of the total machine mass minus the result of wheel loads * wheel contact point vector, and then divided by the corrected mass (Corrected Center of Gravity Vector = (Center of Gravity Vector * Total Machine Mass - Sum of Wheel Loads * Wheel Contact Point Vector)) / Corrected Mass).

[0035] As already stated above with reference to Figure 2As explained, if the machine is completely resting on its outriggers, i.e., fully raised, no vehicle suspension remains. In this configuration, a shift in the center of gravity during operation will not result in any (significant) inherent tilting of the machine before two legs lift off the ground and the machine tips over.

[0036] If a residual wheel load or residual axle load is determined according to the invention, it must be assumed – as also explained above – that part of the machine's own weight is located on at least one of the (sprung) wheels. From this fact, it follows that a shift in the center of gravity will result in a machine tilting before the machine tips over.

[0037] In this case, according to the present invention, inclination-based support monitoring can be carried out, in which the initial inclination of the machine is measured and recorded after completion of the support process.

[0038] During operation, tilt monitoring is performed by measuring the current tilt and comparing it to the recorded initial tilt. If a discrepancy becomes too large, machine movement is restricted. Tilt measurement during operation can be continuous or performed at predefined time intervals. A threshold value (tilt threshold or pre-warning tilt) can be defined or entered for the discrepancy to trigger the restriction of machine movement. This pre-warning tilt is typically set to less than 3.0°, for example, between 0.1° and 2°. Preferably, the pre-warning tilt is no more than approximately 1.0° to 1.2°.

[0039] The Figures 6 and 7 Illustrate in block diagram the process of a method according to the invention 200.

[0040] According to Figure 6First, a mobile work machine 100, as previously described, is positioned 210. Then, the work machine 100 is supported 220 on the ground 28 using the support device 20, 22.

[0041] Subsequently, a computing unit 42, which is preferably part of a control unit 40 of the working machine 100, is used (see schematic representation of the Figure 2 ), a determination 230 of a wheel load acting on at least one wheel of the two wheel axles 31, 32 or alternatively of an axle load acting on the at least two wheel axles 31, 32, which within the scope of the present invention are referred to as residual wheel load or residual axle load. This residual wheel or axle load is taken into account in the performance 240 of a stability calculation for the not fully raised work machine (preferably also in the control device 40 or computing unit 42).

[0042] Figure 7Figure 200 shows a refined representation of the inventive method by showing partial steps 232 and 234 as well as 242 and 244 of method steps 230 and 240 respectively.

[0043] According to the invention, the step of determining 230 the wheel load acting on one wheel of the two wheel axles or the axle load acting on the at least two wheel axles can include measuring 232 the residual wheel load directly at the wheels 30 or the residual axle load directly at the wheel axles 31, 32 (measuring sensor 50) and / or deriving 234 the residual axle load from a force measured in the support device (support legs 20, 22) (measuring sensor 60).

[0044] According to the invention, the step of performing the stability calculation 240 can include subtracting 242 a mass dependent on the residual wheel / axle load from a mass of the working machine 100 or from a mass of the substructure 10.

[0045] Preferably, as described above, the position of at least one residual wheel load can be taken into account in the calculation of the center of gravity position of the working machine or the substructure, i.e., a (at least partial) subtraction 244 of a position of the mass of the residual wheel or axle load(s) from a center of gravity position of the working machine 100 or of the substructure 10 can be carried out.

[0046] The inventive method allows the reach of a work machine, in particular a mobile concrete pump, to be flexibly adapted to the excavation situation of the supported substructure by subtracting from the machine's own weight a mass that rests on the axle that is not fully excavated (when the mass is fully excavated, the mass to be subtracted is zero). Preferably, the center of gravity of the entire machine is also corrected with the axle position of the acting mass (residual wheel load or residual axle load). Reference symbol list

[0047] 10 Substructure 12 Mast stand 14 Working boom 16 Thick fuel pump 18 Material feed hopper 20 Support device, outriggers 22 Support device, outriggers 30 Wheels 31 Wheel axle, front axle 32 Wheel axle, rear axle 34 Wheel springs 40 Control unit 42 Computing unit 50 Measuring sensors 60 Measuring sensors 100Work machine, concrete pump 200Procedure for operating a mobile work machine 210Providing a work machine 220Supporting the work machine 230Determining an axle load 232Measuring the residual axle load 234Deriving the residual axle load 240Performing a stability calculation 242Subtracting a mass 244Subtracting a position

Claims

1. Mobile working machine (100) with a substructure (10) supporting a working boom (14), which has a chassis with at least two wheel axles (31, 32) and wheels (30) arranged thereon, a support device (20, 22) arranged on the substructure (10) which can be supported on a surface (28) when the working machine (100) is raised, and a measuring sensor system (50, 60) for determining a wheel load acting on the wheels (30) of the at least two wheel axles (31, 32), as well as a computing unit (42) for performing a stability calculation, wherein a residual wheel load acting on at least one wheel (30) of a wheel axle (31, 32) when the working machine (100) is not fully raised is included in the stability calculation.

2. Mobile working machine (100) according to claim 1, wherein the measuring sensor (50) is designed for directly measuring the residual wheel load and / or wherein the measuring sensor (60) is designed for measuring a force in the support device (20, 22).

3. Mobile working machine (100) according to claim 1 or 2, wherein the residual wheel load at the time of support of the working machine (100) is included in the stability calculation and / or wherein the residual wheel load is continuously included in the stability calculation during operation of the working boom (14).

4. Mobile working machine (100) according to one of claims 1 to 3, in which, in the stability calculation, a mass dependent on the residual wheel load is subtracted from a mass of the working machine (100) or from a mass of the substructure (10), and preferably additionally, a position of at least one residual wheel load is taken into account in the calculation of the center of gravity position of the working machine (100) or of the substructure (10).

5. Mobile working machine according to one of claims 1 to 4, wherein, in the presence of a residual wheel load, the result of an inclination monitoring is included as a further parameter in the stability calculation, wherein the inclination monitoring preferably comprises measuring and recording an initial inclination after support has been provided and comparing a current inclination during operation of the working machine with the recorded initial inclination.

6. Method (200) for operating a mobile working machine (100), in particular according to one of claims 1 to 5, which, after providing (210) a mobile working machine (100) with at least two wheel axles (31, 32) and a support device (20, 22) on a surface (28) and supporting (220) the working machine (100) on the surface (28) by means of the support device (20, 22), comprises the following steps: - Determining (230) a wheel load acting on at least one wheel (30) of the two wheel axles (31, 32), and - Performing (240) a stability calculation taking into account a residual wheel load acting on at least one wheel (30) of a wheel axle (31, 32) when the working machine (100) is not fully raised.

7. Method (200) according to claim 6, wherein the step of determining (230) the wheel load acting on the at least one wheel (30) comprises: - measuring (232) the residual wheel load directly at the wheel (30) or the wheel axle (31, 32) and / or - deriving (234) the residual wheel load from a force measured in the support device (20, 22).

8. Method (200) according to claim 6 or 7, wherein the stability calculation is performed at the time of support of the working machine (100) and / or wherein the stability calculation is performed continuously during the operation of a working boom (14).

9. Method (200) according to one of claims 6 to 8, wherein the step of performing (240) the stability calculation comprises subtracting (242) a mass dependent on the residual wheel load from a mass of the working machine (100) or from a mass of the substructure (10), and wherein preferably the step of performing (240) additionally includes a position of at least one residual wheel load in the calculation of the center of gravity position of the working machine (100) or of the substructure (10).

10. Method according to one of claims 6 to 9, wherein, in the presence of a residual wheel load, the result of an inclination monitoring is included as a further parameter in the stability calculation, preferably with the steps of measuring and recording an initial inclination after support has been provided and preferably continuously measuring a current inclination during operation of the machine and comparing it with the recorded initial inclination.

11. Computer program with program code means to carry out all steps of a method (200) according to any one of claims 6 to 10, when the computer program is executed on a computer or a corresponding computing unit (42), in particular a control unit (40) of a mobile working machine (100).

12. Control device (40) for a mobile working machine (100), in particular according to one of claims 1 to 5, which is designed to carry out a method (200) according to one of claims 6 to 10, or in which a computer program according to claim 11 is stored suitable for execution.

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