MOBILE WORK MACHINE, IN PARTICULAR EXCAVATORS, WITH A VEHICLE FRAME AND A LIFTING ARM

Description

[0001] The invention relates to a mobile working machine, in particular an excavator, wheel loader, tractor, telescopic loader or the like, with a vehicle frame and with at least one lifting arm for raising and / or lowering a tool holding device according to the preamble of claim 1. State of the art

[0002] Various excavators and mobile work machines with a lifting arm for raising and lowering loads or work tools are known. For example, backhoe loaders in a wide variety of sizes and configurations are used in construction work to move materials such as earth, gravel, sand, or similar substances.

[0003] In this system, a shovel or bucket is attached to the lifting arm by means of a hydraulic cylinder and can be replaced, for example to use a hydraulic hammer for breaking up concrete or rocks on the lifting arm.

[0004] Various backhoes, lifting arms, and similar devices are also known in agriculture. These can be attached to a tractor or its three-point hydraulic system and can be used, for example, with an excavator bucket or a grab cable to move soil, manure, silage, or similar materials.

[0005] Accordingly, the lifting arm is connected to the vehicle frame via a substantially horizontally oriented first pivot axis and / or indirectly via an additional lifting arm holding unit arranged between the lifting arm and the actual frame, whereby, for example, the aforementioned three-point hydraulics or a so-called "swivel console" with a substantially vertically oriented second pivot axis can be provided, for example, in so-called "mini excavators" or the aforementioned backhoe loaders.

[0006] However, EP 0 887 475 B1 already discloses a large excavator in which the lifting arm is rotatably mounted directly to the support frame, but the hydraulic cylinder is pivotally attached to a connecting lever, which in turn is pivotally mounted to the vehicle frame. Furthermore, the hydraulic cylinder and the connecting lever, or rather their common axis of rotation, are pivotally mounted to the lifting arm via a second connecting lever.

[0007] This lever mechanism, or four-axis swivel mechanism, allows for a reduced transport height for large excavators with long lifting arms when they are transported on low-loaders or similar vehicles over roads. This is intended to enable the transport of excavators, for example, under power lines or through tunnels. However, the reduction in transport height is irrelevant for so-called mini-excavators or backhoes for tractors, as these can typically be transported through tunnels and similar structures even on low-loaders.

[0008] During operation, mini excavators can lower their lifting arms accordingly, so that the maximum excavator height / size is determined not by the lifting arm, but by the operator's cab. For this purpose, they often have foldable or collapsible operator's cabs to temporarily reduce the maximum vehicle height, for example, to pass through a doorway or garage door. Purpose and advantages of the invention

[0009] In contrast, the object of the invention is to propose a mobile working machine, in particular an excavator, wheel loader, tractor, telescopic loader or the like, with a vehicle frame and with at least one lifting arm for raising and / or lowering a tool holding device, which at least partially improves the performance and / or stability of the working machine or the lifting arm.

[0010] This problem is solved, starting from a mobile work machine of the type mentioned in the introduction, by the features of claim 1. Advantageous embodiments and further developments of the invention are possible by the measures mentioned in the dependent claims.

[0011] Accordingly, a mobile working machine according to the invention is characterized in that the first lifting arm end section of the lifting arm has at least one receiving recess arranged between two arm cheek sections for receiving at least one end of the second lever element, wherein the two arm cheek sections are designed to receive at least the second lever shaft, and that the second lever element has a double curved shape and / or is S-shaped.

[0012] With the aid of the two arm cheek sections or the receiving recess according to the invention, a particularly compact and stable design of the lifting arm is possible. In addition, the driver can, for example, see through between the two arm cheek sections or the receiving recess, thus significantly improving their view and control of the work tool or the work area.

[0013] Furthermore, the arrangement of the second lever element between the two arm cheek sections advantageously allows for the second lever element to be supported on both sides of the lifting arm. This enables a particularly stable, torsionally rigid mounting of the second bearing shaft or the second lever element. This is especially advantageous under the high loads / forces encountered in excavators or similar equipment.

[0014] Thus, the bearing width of the lifting arm does not need to be widened according to the invention, so that, for example, in systems with swivel brackets or the like according to the invention, there are no restrictions in the swivel angle / range.

[0015] In contrast, EP 0 887 475 B1 discloses two separate levers or connecting pieces, arranged on either side of the lifting arm and supported on one side, between the lifting cylinder and the lifting arm. This necessitates not only a cantilevered bearing but also a comparatively wide design with relatively long bearing shafts.

[0016] Preferably, the second lever element is arranged at least partially within the lifting arm and / or between the two arm cheek sections, and / or the two arm cheek sections are arranged side by side in a horizontal direction, with the receiving recess oriented vertically. This enables a particularly stable and compact design.

[0017] In a preferred embodiment of the invention, the first and second holding shafts and the first and second lever shafts are aligned in a horizontal direction. This creates an advantageous four-point mechanism by means of which the lifting arm and the lifting cylinder can be pivoted.

[0018] In an advantageous embodiment of the invention, at least one vertically oriented bearing shaft for horizontal pivoting of the lifting arm is arranged between the vehicle frame and the lifting arm support unit. This increases the flexibility of the lifting arm, which can pivot about this vertical axis of rotation, thus increasing the working range.

[0019] Advantageously, at least one boom arm is arranged between the lifting arm and the tool holder, and in particular, at least one boom shaft is arranged between the lifting arm and the boom arm. This allows a further arm to be pivoted advantageously, which increases the reach of the machine when the work location is fixed.

[0020] In a particular embodiment of the invention, the second lever element comprises at least two lever cheeks that receive the first lever shaft, wherein the lifting cylinder is arranged at least partially between the two lever cheeks, and / or the first lever element comprises at least two cheeks that receive the first lever shaft, wherein the lifting cylinder is arranged at least partially between the two cheeks, in particular the two lever cheeks of the second lever element are arranged at least partially between the two cheeks of the first lever element. This advantageously allows for double-sided support of the lifting cylinder / hydraulic cylinder and / or the second lever element, resulting in a particularly stable and rigid mounting. This is especially advantageous under the high loads / forces encountered in excavators or similar applications.

[0021] In general, according to the invention, the following advantageous features or measures can be implemented individually and / or in combination with one another: Advantageously, the first distance between the first holding shaft and the second lever shaft is smaller than the second distance between the second holding shaft and the first lever shaft. The second lever element has a double-curved shape or is S-shaped. Advantageously, during operation of the machine, i.e., in a movement cycle from a lower end position of the lifting arm to an upper end position of the lifting arm and vice versa, the second lever shaft performs an arc-shaped movement that at least partially surrounds the first holding shaft. The same applies to the second lever element, which also moves at least partially around the first holding shaft. Advantageously, neither the second lever shaft nor the second lever element intersects the axis of the first holding shaft. The lifting arm is advantageously arranged in front of the cab, particularly centrally.Unlike many large excavators, where the lifting arm must be positioned to the side of the cab to enable its swiveling, especially so-called "mini-swing excavators," such large excavators can rotate the upper structure without any component of the upper structure protruding beyond the outer dimensions of the undercarriage. However, in a particular, alternative embodiment of the invention, the lifting arm can also be arranged centrally. According to an advantageous embodiment, the lifting arm is located essentially centrally on a transverse side of a so-called...

[0022] The arm is arranged on the "superstructure" of the work machine or excavator, wherein the superstructure is rotatable about a substantially vertically oriented axis of rotation (not shown in detail) on a mobile "undercarriage," in particular with the track drive or wheel unit. The arm is positioned in front of an operator's workstation. According to this embodiment, the upward or backward pivoting of the arm is therefore limited by the safety zone of the operator or a cabin. Consequently, the arm is at least partially substantially vertical in its upper end position. This means that, according to this embodiment, the longitudinal axis of the foot end of the lifting arm extends substantially vertically in its upper end position.

[0023] Initial tests and investigations with a machine according to the invention have surprisingly shown that, compared to previously used arrangements and mechanisms, an improved / increased lifting force can be achieved. Specifically, in the upper lifting range, i.e., when the lifting arm is raised, a particularly high torque is present, e.g., approximately 50% to 60% compared to previously used lifting arms.

[0024] This advantageously allows for the lifting of larger loads, particularly in the upper area, with approximately the same dimensions for the lifting cylinder, especially the hydraulic cylinder, and / or the lifting arm, i.e., without reinforcing the structure or walls, etc. Accordingly, greater performance of the mobile work machine is achieved in an energy-saving and therefore environmentally friendly manner. This is accomplished with a nearly identical / comparable weight for the lifting arm assembly or the entire boom, so that, for example, a larger drive motor and / or a more robust hydraulic system are not required. This enables a cost-effective and economical implementation of the invention, especially for retrofitting existing mobile work machines such as excavators or similar equipment.

[0025] In addition to the significantly improved lifting capacity compared to previously common systems, the now lower pressure level of the lifting cylinder, which previously often carried the load pressure, can have a positive effect on the energy balance of the hydraulic system and thus also on the overall performance, productivity and economy of the mobile working machine according to the invention.

[0026] In initial tests, for example, a mini excavator was able to lift and transport a vibratory plate compactor, something that previously could not do without the inventive design. Accordingly, the invention has significantly improved and expanded the operational capability and performance of the mini excavator in question. Example of implementation

[0027] An embodiment of the invention is shown in the drawing and is explained in more detail below with reference to the figures.

[0028] In detail: Figure 1 is a schematic representation of a mini excavator with a lifting arm according to the invention in the middle position; Figure 2 is a schematic, enlarged and partially cutaway section of the lifting arm according to the invention. Figure 1 Figure 3 is a schematic representation of the mini excavator according to Figure 1 with lifting arm in upper position and Figure 4 a schematic representation of the mini excavator according to Figure 1 with lifting arm in lower position.

[0029] The figures schematically depict a so-called mini-excavator 1, which has a lifting and lowering lifting arm 2, wherein the lifting arm 2 can be operated or adjusted / swivelled with a hydraulic cylinder 3.

[0030] In a generally conventional manner, the mini excavator 1 includes a driver's cab 4 and, as drive elements, two track drives 5 and an optional dozer blade 6.

[0031] In the illustrated mini-excavator 1, the lifting arm 2 is arranged / mounted on a so-called swivel console 7. With the help of the optionally provided, already widely used swivel console 7, which has a vertically oriented swivel axis 8 (see figure). Figure 2 The lifting arm 2 can be pivoted horizontally, i.e., to the right and / or left, about the pivot axis 8. This increases the flexibility and usability of the mini excavator 1.

[0032] The swivel console 7 or lifting arm support unit 7 can also be an integral part of a vehicle frame or the so-called "upper structure" of an excavator. Therefore, a swivel console 7 is not necessarily required.

[0033] According to the invention, the lifting arm 2 has two cheeks 10 at a lower foot end 9, between which a connecting rod 11 is rotatably mounted. In addition, a connecting rod 12 is arranged between the hydraulic cylinder 3 and the swivel bracket 7, so that a particularly compact and stable arrangement / mounting is achieved.

[0034] This is especially true in Figure 2 , in which, among other things, the connecting rod 11 is shown in section, it can be seen that a total of four axes of rotation 13 to 16 or shafts 13 to 16 are provided, around which or with which the lifting arm unit or the lifting arm 2 and the hydraulic cylinder 3 as well as the rods 11, 12 are pivotably mounted.

[0035] The connecting rod 11, in turn, has a fork in its lower section (not shown in detail for clarity) that surrounds the hydraulic cylinder or between which the cylinder is positioned. Furthermore, another fork of the connecting rod 12 surrounds this fork of the connecting rod 11 in the area of ​​the axle / shaft 14, resulting in a particularly compact and stable arrangement / bearing.

[0036] Advantageously, the axis / shaft 10 for pivoting the connecting rod 11 is arranged (essentially) parallel to the axis / shaft 16 for pivoting the lifting arm 2.

[0037] Furthermore, the two axes / shafts 13, 14 of the connecting rod 12 are (essentially) aligned / arranged parallel to each other. It is precisely by means of the connecting rod 12 that advantageous leverage ratios are achieved in the upper lifting range of the lifting arm 2 (cf. Figure 3), so that particularly large torques or lifting forces can be achieved here.

[0038] Furthermore, a tool arm 17 is pivotably arranged on the lifting arm 2, to which a detachably connectable or replaceable tool (not shown in detail) can be attached in a known manner.

[0039] In general, according to the invention, the following advantageous features and measures can be implemented individually and / or in combination with one another: Advantageously, the distance between the first holding shaft 16 and the second lever shaft 15 (in all positions of the lifting arm 2) is smaller than the distance between the second holding shaft 13 and the first lever shaft 14. The second lever element 11 advantageously has a double-curved shape or is S-shaped. The second lever shaft 15 advantageously moves during operation of the working machine 1, i.e., in one movement cycle from a lower end position of the lifting arm 2 (cf. Figure 4) to an upper end position of the lifting arm 2 (see Figure 3 ) an arc-shaped movement that runs at least partially around the first retaining shaft 16. The same applies to the second lever element 11, which moves at least partially around the first retaining shaft 16. Advantageously, neither the second lever shaft 15 nor the second lever element 11 intersects the axis of the first retaining shaft 16. The arm 2 is arranged in front of the cab 4, specifically in the center. In contrast to many large excavators, where the arm 2 must be positioned to the side of the cab 4 to achieve the pivoting motion as described in Fig. 1To achieve this, especially with so-called "mini-swing excavators," such large excavators can rotate their upper structure without any component of the upper structure protruding beyond the outer dimensions of the undercarriage. This allows the excavator to operate even in extremely confined construction sites. As a special, alternative variant, however, the lifting arm 2 can also be positioned centrally. According to the illustrated embodiment, the arm 2 is arranged essentially centrally on a transverse side of the upper structure of an excavator, the upper structure being rotatable about a substantially vertically oriented axis of rotation (not shown in detail) on a mobile undercarriage, in particular with the track drive 5.

[0040] The arm 2 is positioned in front of an operator's workstation. According to the illustrated embodiment, the upward and backward pivoting of the arm 2 is therefore limited by the operator's safety zone or a cabin. Consequently, in its upper end position, the arm 2 is essentially vertical, at least in some areas. This means that, according to the illustrated embodiment, the longitudinal axis of the foot end 9 of the lifting arm 2 extends essentially vertically in its upper end position. Reference symbol list

[0041] 1 Mini excavator 2 Lifting arm 3 Hydraulic cylinder 4 Operator's cab 5 Track drive 6 Dozer blade 7 Swivel console 8 Swivel axle 9 Foot end 10 Side arm 11 Rod 12 Rod 13 Axle / shaft 14 Axle / shaft 15 Axle / shaft 16 Axle / shaft 17 Tool arm

Claims

1. Mobile working machine (1), in particular excavator (1), earthmover, tractor, telehandler or the like, with a vehicle frame and with at least one lift arm (2) for lifting and / or lowering a tool holding device, wherein a drive unit for driving at least one drive element (5) such as a drive wheel or a drive chain (5) is provided, wherein at least the tool holding device is designed for holding a releasably connectable working tool, in particular a bucket, grab bucket, fork arms, grab fork or the like, wherein at least one lift cylinder (3), in particular a hydraulic cylinder (3), is arranged on the lift arm (2), wherein at least one lift arm holding unit (7) is provided for holding / mounting the lift arm (2) and / or the lift cylinder (3), wherein a first holding shaft (16) for pivoting the lift arm (2) is arranged between the lift arm holding unit (7) and a first lift arm end portion (9), in particular a bottom end (9), of the lift arm (2), and at least one first lever element (12) is arranged between the lift arm holding unit (7) and the lift cylinder (3), wherein at least one second holding shaft (13) is provided between the lift arm holding unit (7) and the first lever element (12), and at least one first lever shaft (14) is provided between the first lever element (12) and the lift cylinder (3), wherein at least one second lever element (11) is arranged between the lift arm (2) and the first lever shaft (12) or the lift cylinder (3), wherein at least one second lever shaft (15) is arranged between the second lever element (11) and the lift arm (2), characterized in that the first lift arm end portion (9) of the lift arm (2) has at least one receiving recess arranged between two arm cheek portions (10) for receiving at least one end of the second lever element (11), wherein the two arm cheek portions (10) are designed for receiving at least the second lever shaft (15), and in that the second lever element (11) has a double curved shape and / or is S-shaped.

2. Working machine according to Claim 1, characterized in that the second lever element (11) is arranged at least partially within the lift arm (2) and / or between the two arm cheek portions (10).

3. Working machine according to one of the preceding claims, characterized in that the two arm cheek portions (10) are arranged next to one another in the horizontal direction, with the result that the receiving recess is oriented in the vertical direction.

4. Working machine according to one of the preceding claims, characterized in that the first and second holding shaft (16, 13) and the first and second lever shaft (14, 15) are oriented in the horizontal direction.

5. Working machine according to one of the preceding claims, characterized in that at least one vertically oriented bearing shaft (8) is arranged between the vehicle frame and the lift arm holding unit (7) for horizontal swivelling of the lift arm (2).

6. Working machine according to one of the preceding claims, characterized in that at least one boom arm (17) is arranged between the lift arm (2) and the tool holding device.

7. Working machine according to Claim 6, characterized in that at least one boom shaft is arranged between the lift arm (2) and the boom arm (17).

8. Working machine according to one of the preceding claims, characterized in that the second lever element (11) comprises at least two lever cheeks which receive the first lever shaft (14), wherein the lift cylinder (3) is arranged at least partially between the two lever cheeks.

9. Working machine according to one of the preceding claims, characterized in that the first lever element (12) comprises at least two cheeks which receive the first lever shaft (14), wherein the lift cylinder (3) is arranged at least partially between the two cheeks.

10. Working machine according to Claim 8 and according to Claim 9, characterized in that the two lever cheeks of the second lever element (11) are arranged at least partially between the two cheeks of the first lever element (12).