Mobile working machine with a pivotable boom

Abstract

A mobile work machine (1) with a vehicle frame and with a boom (5) pivotable about a pivot axis with respect to the vehicle frame is proposed, wherein the boom (5) comprises a vertical boom longitudinal center plane (25) oriented perpendicular to the pivot axis and a tool holding device (9) for holding a work tool, wherein at least one lifting cylinder (23) having a first piston and a first piston rod is provided for pivoting the boom (5) relative to the vehicle frame, wherein a tilting unit for pivoting / tilting the tool holding device (9) relative to the boom (5) comprises at least one tilting lever (29) and a tilting cylinder (24) having a second piston rod and a second piston, wherein the tilting cylinder (24) is rotatably arranged / mounted at a first end (31) of the tilting lever (29), wherein a tilting rod (26) is rotatably arranged / mounted at a second end (32) of the tilting lever (29).wherein the disadvantages of the prior art are at least partially improved or avoided, in particular the installation space is optimized, with only one lifting cylinder (23) being present within the boom (5) or the rocker contour, if possible. This is achieved, among other things, by the tilting rod (26) being movable on the vertical boom longitudinal center plane (25), wherein the first end (31) of the tilting lever (29) is arranged offset next to the vertical boom longitudinal center plane (25) when viewed in the horizontal direction.

Description

[0001] The invention relates to a mobile work machine, in particular a wheel loader, telescopic loader, excavator, tractor or the like, with a pivotable boom. State of the art

[0002] Mobile work machines, especially wheel loaders, telehandlers, excavators, tractors, or the like, with a vehicle frame and a drive unit for driving at least one drive element such as a wheel or track, are nowadays usually powered by a refillable fuel. Diesel-powered vehicles are primarily used today. Electric-powered machines are also now in use.

[0003] Except for wheel loaders with large buckets on the lifting arm, modern mobile work machines often feature detachably connectable work tools, e.g., which are held or released using so-called "quick couplers" or "interchangeable plates." In addition to "passive" work tools such as shovels, bale forks, or the like, there are also work tools such as brooms, mulchers, grapple arms, grab buckets, lifting forks, or the like, which accordingly feature an "active" or energy-driven tool.

[0004] Currently, loaders typically have a loading boom with a two-arm boom. To raise the boom, two lifting cylinders are generally used, each mounted below one of the boom arms, usually on the outside of the frame. To tilt the implement, particularly the bucket or fork, a so-called TP kinematics is often used. A hydraulic cylinder, the so-called tilt cylinder, is mounted centrally below the boom. This cylinder, via Z-kinematics and a bell crank, actuates a drawbar or tilt rod. This drawbar or tilt rod, in turn, often actuates another bell crank and another drawbar or tilt rod via a parallel kinematic. The latter then actuates a mounting plate for attachments or the implement.

[0005] Disadvantages include the large installation space, the double design of the lifting cylinders, located laterally below the swing arms, including hoses and mounting, increased costs, increased risk of failure, and increased maintenance. This also includes additional machining of the frame, which in turn leads to increased costs. This also restricts the field of vision of the attachment or tool. Due to the central mounting of the tilt cylinder, there is no space for an internal lifting cylinder, i.e., between the two swing arms, especially on smaller machines.

[0006] In addition, if one lifting cylinder is blocked when two lifting cylinders are installed, the second cylinder acts against the other and thus causes damage to the loading arm. Object and advantages of the invention

[0007] The object of the invention is, in contrast, to propose a mobile work machine, wherein the disadvantages of the prior art are at least partially improved or avoided, in particular the installation space is optimized, wherein, if possible, only one lifting cylinder is present within the boom or the swing arm contour and / or the view of the attachment is improved and / or low costs and / or lower error potential can be realized.

[0008] This object is achieved by the features of claim 1, starting from a mobile work machine of the type mentioned in the introduction. Advantageous embodiments and further developments of the invention are possible through the measures mentioned in the subclaims.

[0009] Accordingly, a mobile work machine according to the invention comprises a vehicle frame, a boom pivotable about a pivot axis with respect to the vehicle frame, wherein the boom comprises a vertical boom longitudinal center plane oriented perpendicular to the pivot axis, and a tool holding device for holding a work tool, wherein at least one lifting cylinder having a first piston and a first piston rod is provided for pivoting the boom relative to the vehicle frame, wherein the boom has at least one first rocker and a second rocker, wherein a distance is provided between the first and the second rocker, wherein a tilting unit for pivoting / tilting the tool holding device relative to the boom comprises at least one rocker arm and a tilting cylinder having a second piston rod and a second piston,wherein the tilt cylinder and / or the tilt lever are arranged at least partially between the first and the second rocker, wherein the tilt lever of the tilt unit is pivotable about a rotational axis oriented transversely, in particular perpendicularly, to the vertical longitudinal center plane of the boom, wherein the tilt lever connects a tilt rod and the tilt cylinder, wherein the tilt cylinder is rotatably arranged / mounted at a first end of the tilt lever, wherein the tilt rod is rotatably arranged / mounted at a second end of the tilt lever, wherein the tilt rod is movable on the vertical longitudinal center plane of the boom, wherein the first end of the tilt lever is arranged offset next to the vertical longitudinal center plane of the boom, viewed in the horizontal direction.

[0010] This measure allows for more flexible positioning and arrangement of the tilt cylinder, in particular. This opens up new possibilities regarding its placement and / or the arrangement of the lifting cylinder. As a result, the tilt cylinder does not necessarily have to be positioned centrally on the vertical longitudinal center plane of the boom; instead, the tilt cylinder can be positioned almost anywhere. The lifting cylinder can also be arranged almost anywhere. This allows the use of a single lifting cylinder and significantly improves, among other things, cost-effectiveness, operational reliability, and visibility of the tool.

[0011] In principle, the boom can have a longitudinal axis that lies on the vertical longitudinal center plane of the boom. Preferably, the vertical longitudinal center plane of the boom or the longitudinal axis of the boom, viewed in the horizontal direction, is arranged / aligned in the center of the boom or between the two boom rockers.

[0012] Advantageously, the second end of the tilt lever is positioned horizontally on the vertical longitudinal center plane of the boom, particularly centrally. This optimizes the design effort as well as the force ratios and force transmission to the tilt rod. Costs and operational reliability are also improved, especially with regard to the tilt rod, which is movably arranged on the vertical longitudinal center plane of the boom.

[0013] In a special development of the invention, the tilt cylinder is arranged on a first side of the vertical boom longitudinal center plane, viewed horizontally, and the lifting cylinder is arranged on a second side of the vertical boom longitudinal center plane, opposite the first side. This enables a particularly space-saving design and provides the operator with an advantageous view of the implement.

[0014] It is conceivable that, viewed in the horizontal direction, the tilt cylinder or its longitudinal axis and / or its piston rod is arranged at an acute angle to the vertical boom longitudinal center plane, e.g., at an angle between 1° and 25° relative to the vertical boom longitudinal center plane. However, the first piston rod of the lifting cylinder is preferably arranged parallel to the vertical boom longitudinal center plane and / or the second piston rod of the tilt cylinder is arranged parallel to the vertical boom longitudinal center plane. This allows advantageous force ratios to be achieved.

[0015] Advantageously, an offset section is provided between the first end of the rocker arm and the second end of the rocker arm, viewed in the direction of the rocker arm's rotational axis. The advantageous offset section between the two ends of the rocker arm can advantageously compensate for the offset between the two cylinders or their arrangement.

[0016] In an advantageous variant of the invention, the tilt cylinder is arranged at the first end of the tilt lever, and the tilt rod is arranged at the second end of the tilt lever. This results in advantageous tilt kinematics.

[0017] In a particular development of the invention, the rocker arm has a first lever rocker and a second lever rocker, with a lever spacing provided between the first and second lever rockers, particularly when viewed horizontally. This results in a particularly stable and rigid construction of the rocker arm. This improves operational reliability and longevity.

[0018] For exampleThe offset distance between the first end of the rocker arm and the second end of the rocker arm can be realized with two linear levers that are offset from one another on the rocker arm's rotational axis, particularly a sleeve or similar. Thus, the first and second lever rockers can advantageously be arranged at a right angle or 90° with respect to the rotational axis, with the offset distance between them being realized in the direction of the rotational axis.

[0019] Advantageously, an angle is provided between the rotational axis of the rocker arm and the first lever rocker, and between the rotational axis of the rocker arm and the second lever rocker, wherein the angle is less than 90°, in particular between 60° and 85°, preferably between 75° and 85°. This allows an oblique arrangement of the rocker arm with respect to the rotational axis to be realized. This reduces the effort required, for example, to achieve a particularly stable offset between the first and second ends. Accordingly, the offset distance between the first end of the rocker arm and the second end of the rocker arm is advantageously implemented by means of this incline.

[0020] In an advantageous variant of the invention, at least one stiffening element is provided on each side of the rotation axis, aligned in the longitudinal direction of the rotation axis, to stiffen the first and / or second lever rocker. This allows for particularly stable force ratios to be achieved.

[0021] In general, the invention eliminates the need for a single cylinder to be mounted centrally to the swing arm's longitudinal axis or the vertical boom's longitudinal center plane. Instead, a tilting and a lifting cylinder can be mounted side by side within the swing arm. This is made possible, for example, by a bent bellcrank or tilting lever, which allows for the central application of force to the front bellcrank and thus to the support plate or tool.

[0022] In principle, to maximize the available space, the lifting and tilting cylinders can be arranged side by side within the boom, especially in a bearing block. In this case, the tilting lever can be advantageously designed so that the force from the off-center tilting cylinder is redirected to the central linkage of the tilting rod. This results in a new, advantageous tilting lever shape. Character description

[0023] An embodiment of the invention is shown in the drawing and is explained in more detail below with reference to the figures.

[0024] In detail: Figure 1 shows a schematic, perspective view of an exemplary, first, mobile work machine, in particular a wheel loader, Figure 2 shows a schematic top view of a section of a boom according to the invention of a second, mobile work machine and Figure 3 shows a schematic, sectional side view of the boom according to Figure 2 in two different tilt positions.

[0025] In Figure 1 A mobile work machine 1 or a drive vehicle 4, a wheel loader 1, is schematically shown with an attachment or a work tool 2. The work tool 2 in this case is a so-called "grab bucket" 2, meaning that this bucket is not only "passive," but that a part of the grab bucket 2 can be actively adjusted by means of two hydraulic cylinders 3, e.g., for quickly emptying construction material such as gravel or sand.

[0026] Without further illustration, the drive vehicle 4 advantageously has a drive motor, in particular a diesel engine or electric motor, and a hydraulic pump in order to provide, on the one hand, the drive energy for drive wheels, in particular for an all-wheel drive, and, on the other hand, the hydraulic energy, for example, for a lifting arm 5 or boom 5, a steering system 6 and the working tool 2 or the grab bucket 2, ie the hydraulic cylinders 3, and to be able to operate them accordingly.

[0027] A driver (not shown) controls the work machine 1 or the work tool 2 from a driver's seat 7 and, in addition to the steering 6, also has a control element 8 or a so-called "control stick" 8, i.e. also referred to / known as a so-called "joystick" 8, at his disposal.

[0028] In addition, the wheel loader 1 has a tool holding device 9 or a so-called "quick-change system" or a so-called "quick-change plate," which in this case can be operatively connected to two receptacles 10 of the work tool 2. Thus, on each side of the lifting arm 5, i.e., on both sides of a so-called vertical longitudinal center plane of the drive vehicle 4, an upper recess of the receptacle 10 can accommodate a bolt 11 of the tool holding device 9, and a lower bore 12 of the receptacle 10 can accommodate a latch 13 of the tool holding device 9 or a piston 13 of an actuator 14. Vertical and horizontal distances as well as diameters or dimensions of the receptacles 10, bars 13, bores 12 etc. are advantageously standardized so that a wide variety of work tools 2 such as shovels, lifting forks, grapples, brooms, snow plows etc. can be coupled and uncoupled, i.e. replaced, on the lifting arm 5 quickly and without great effort.

[0029] Figure 2shows a schematic section of a boom 5 or lifting arm 5 of an advantageous variant according to the invention. The lifting arm 5 has two spaced-apart rockers 21, 22. A vertical boom longitudinal center plane 25 as well as a lifting cylinder 23 for raising and lowering the lifting arm 5 and a tilting cylinder 24 for tilting the tool 2 or the tool holding device 9 are arranged centrally between the rockers 21, 22. In the present case, the vertical boom longitudinal center plane 25 is identical to the vertical vehicle longitudinal center plane, since the lifting arm 5 or boom 5 is arranged centrally or on the vertical vehicle longitudinal center plane of the work machine 1. Work machines are also available, e.g. telescopic loaders, etc., in which the lifting arm 5 or telescopic arm is arranged off-center next to the cabin, so that the vertical vehicle longitudinal center plane is arranged offset parallel to the vertical boom longitudinal center plane 25.In addition, a tilting rod 26 and a deflection or lever mechanism 27 are arranged on the vertical boom longitudinal center plane 25.

[0030] A tilt lever 29 is arranged between the tilt cylinder 24 and the tilt rod 26 around a rotation axis 28. The tilt lever 29 has a first end 31 for the tilt cylinder 24 and a second end 32 for the tilt rod 26. Both the tilt cylinder 24 and the tilt rod 26 are rotatably mounted on the tilt lever 29.

[0031] In Figure 3 Two different tilt positions of the tilt kinematics, particularly the TP kinematics, are shown. These show how the tilt system is positioned with the piston rod of the tilt cylinder 24 retracted and with the piston rod of the tilt cylinder 24 extended, as well as which element can be rotated around which axis.

[0032] Figure 2illustrates an advantageous embodiment of the tilting lever 29 according to the invention. Thus, the first end 31 for the tilting cylinder 24 is arranged to the left of the vertical boom longitudinal center plane 25, viewed in the horizontal direction. Overall, in the illustrated variant, the tilting cylinder 24 is arranged parallel to the vertical boom longitudinal center plane 25, viewed in the horizontal direction, particularly on the left. Likewise, the lifting cylinder 23 is arranged parallel to the vertical boom longitudinal center plane 25, viewed in the horizontal direction, but on the other or right side of the vertical boom longitudinal center plane 25.

[0033] The second end 32 of the rocker arm 29 is arranged on the vertical longitudinal center plane 25 of the boom. In the present case, the advantageous rocker arm 29 has two spaced-apart lever rockers 33, 34, which are aligned at an acute angle to the rotational axis 28 of the rocker arm 29. In addition to stabilization, the rocker arm 29 advantageously has two stiffening elements 35, 36 between the two lever rockers 33, 34 and on either side of the rotational axis 28.

[0034] In general, the rocker arm 29 can advantageously be manufactured as a welded construction or from a cast iron. Furthermore, the invention can be used for mobile work machines such as loaders, etc., with articulated steering as well as with single-wheel or all-wheel steering.

Claims

1. A mobile work machine (1) comprising a vehicle frame and a boom (5) pivotable about a pivot axis relative to the vehicle frame, wherein the boom (5) comprises a vertical boom longitudinal center plane (25) oriented perpendicular to the pivot axis and a tool holding device (9) for holding a work tool (2), wherein at least one lifting cylinder (23) having a first piston and a first piston rod is provided for pivoting the boom (5) relative to the vehicle frame, wherein the boom (5) has at least one first rocker (21) and a second rocker (22), wherein a distance is provided between the first and second rockers (21, 22), wherein a tilting unit for pivoting / tilting the tool holding device (9) relative to the boom (5) comprises at least one rocker arm (29) and a tilting cylinder (24) having a second piston rod and a second piston,wherein the tilt cylinder (24) and / or the tilt lever (29) are arranged at least partially between the first and the second rocker (21, 22), wherein the tilt lever (29) of the tilt unit is pivotable about a rotation axis (28) oriented transversely to the vertical boom longitudinal center plane (25), wherein the tilt lever (29) connects a tilt rod (26) and the tilt cylinder (24), wherein the tilt cylinder (24) is rotatably arranged / mounted at a first end (31) of the tilt lever (29), wherein the tilt rod (26) is rotatably arranged / mounted at a second end (32) of the tilt lever (29), wherein the tilt rod (26) is movable on the vertical boom longitudinal center plane (25), wherein the first end (31) of the tilt lever (29) is arranged offset next to the vertical boom longitudinal center plane (25) when viewed in the horizontal direction.

2. Working machine according to claim 1, characterized in thatthe second end (32) of the rocker arm (29) is arranged on the vertical boom longitudinal center plane (25) when viewed in the horizontal direction.

3. Working machine according to one of the preceding claims, characterized in that viewed in the horizontal direction, the tilting cylinder (24) is arranged on a first side of the vertical boom longitudinal center plane (25) and the lifting cylinder (23) is arranged on a second side of the vertical boom longitudinal center plane (25) opposite the first side.

4. Working machine according to one of the preceding claims, characterized in that the first piston rod of the lifting cylinder (23) is arranged parallel to the vertical boom longitudinal center plane (25) and / or that the second piston rod of the tilting cylinder (24) is arranged parallel to the vertical boom longitudinal center plane (25).

5. Working machine according to one of the preceding claims, characterized in thatviewed in the direction of the axis of rotation (28) of the rocker arm (29), an offset section is provided between the first end (31) of the rocker arm (29) and the second end (32) of the rocker arm (29).

6. Working machine according to one of the preceding claims, characterized in that the tilt cylinder (24) is arranged at the first end (31) of the tilt lever (29) and the tilt rod (26) is arranged at the second end (32) of the tilt lever (29).

7. Working machine according to one of the preceding claims, characterized in that the rocker arm (29) has a first lever rocker (33) and a second lever rocker (34), wherein a lever distance is provided between the first and the second lever rocker (33, 34).

8. Working machine according to one of the preceding claims, characterized in thatan angle is provided between the axis of rotation (28) of the rocker arm (29) and the first lever rocker (33) and between the axis of rotation (28) of the rocker arm (29) and the second lever rocker (34), wherein the angle is less than 90°.

9. Working machine according to one of the preceding claims, characterized in that the angle is between 75° and 85°.

10. Working machine according to one of the preceding claims, characterized in that on both sides of the axis of rotation (28) of the rocker arm (29) at least one stiffening element (35, 36) aligned in the longitudinal direction of the axis of rotation (28) is provided for stiffening the first and / or the second lever rocker (33, 34).

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