WORK MACHINE, IN PARTICULAR MATERIAL HANDLING DEVICE WITH A BOOM AND BOOM CLAMPING

Description

[0001] The invention relates to a working machine, in particular a material handling device with a boom and a boom bracing system that can be operated by means of an actuator.

[0002] Material handling machines, such as excavators, comprise a boom system to which the required attachment is mounted. The boom is regularly pivoted on the machine's slewing platform. During operation, the load lifted by the attachment generates a bending moment on the boom system, which necessitates appropriate technical measures to ensure boom stability, especially with large machines or high payloads.

[0003] To increase the load-bearing capacity of the material handler, the boom system must therefore be dimensioned more robustly, which, however, has a negative impact on the manufacturing costs for the machine as well as its weight and thus energy efficiency.

[0004] To avoid the aforementioned disadvantages, an alternative approach was taken in WO 2018 / 138409 A1. An excavator with a guyed boom system is proposed. However, the solution shown has the disadvantage that a reduction of the bending moment cannot be achieved uniformly over the entire boom length. Excavators, in particular, are regularly built with special boom shapes that do not have a straight profile, but instead are banana-shaped, angled, or kinked. Furthermore, the solution in WO 2018 / 138409 A1 neither considers nor reduces lateral moments.

[0005] A working machine with the features of the preamble of claim 1 is known from DE 20 2005 009317 U1.

[0006] The present application therefore aims to equip a previously known work machine, in particular a material handling machine such as an excavator, with an improved boom bracing system in order to eliminate the aforementioned deficiencies and ideally to further optimize the maximum payload of the machine.

[0007] This problem is solved by a working machine according to the features of claim 1. Advantageous embodiments of the working machine are the subject of the dependent claims.

[0008] It is generally proposed that the actuator for operating the boom bracing is articulated to the turntable. However, the actuator is not directly connected to the boom bracing, but instead indirectly via a connecting element in the form of an actuator lever. Such an actuator lever is connected on one side to the mechanically moved actuator element and on the other side to the bracing, in particular to at least one tension element of the bracing. The actuator lever is also rotatable, preferably about a horizontal axis, and is articulated to the handling device, in particular the turntable. With the described kinematics, the actuator can introduce the necessary tensile force into the bracing.

[0009] According to the invention, the working machine has a stick pivotably articulated to the boom, wherein the boom bracing consists of two or more tension elements which are connected to each other and to the boom by means of at least one connecting lever attached to the boom, and wherein the connecting lever(s) is / are rotatably or rigidly articulated to the boom and the at least one connecting lever is articulated to a boom cross tube, in particular to a cross tube for introducing the lifting actuator forces or the stick actuator forces into the boom.

[0010] The proposed kinematics allow for a simple reduction of bending moments over a larger range of the boom length. Particularly with special boom shapes, the distance between the bracing and the neutral axis of the boom can be adjusted to the boom contour as needed. Furthermore, the proposed kinematics offer a degree of universality with regard to installed boom types or sizes; that is, the combination of actuator and actuator lever, as well as their specific arrangement on the turntable, can be universally applied to different boom types and sizes, ideally with consistent bearing positions on the turntable.

[0011] Furthermore, this design offers advantages when using an energy recovery system, for example, by means of an energy recovery cylinder arranged on the boom or superstructure, as it allows for optimization of the torque characteristic curve of the energy recovery system around the boom attachment point. Energy recovery in this context occurs when lowering the working equipment. Here, the potential energy of the boom assembly is stored in a pressure medium, e.g., by compressing a gaseous medium.

[0012] The actuator lever can be pivotally connected to the superstructure at its end, with the actuator and bracing then engaging at the free end of the actuator lever. The actuator is therefore designed as a pull actuator. If the actuator is designed as a cylinder, the tensile tension in the bracing can be increased by retracting the cylinder rod. Alternatively, the actuator lever can be connected to the actuator at its first end and to the bracing at its second end. The pivot point of the actuator lever then lies between these connection points, preferably closer to the end connection point of the actuator. In this case, the actuator is designed as a push actuator, so that when using a cylinder actuator, an extension movement of the piston rod increases the tensile tension in the bracing.

[0013] According to the invention, the boom bracing is designed in multiple parts. It is conceivable that it consists of several bracing elements or tension elements connected to one another via appropriate connection points. It is conceivable and particularly advantageous if individual tension elements are connected to one another via corresponding connecting levers. Such connecting levers are hinged to the boom at one end, while the tension elements are mounted at the free end of the connecting levers. This provides additional support for the bracing against the boom. The connecting levers can be either rotatably or rigidly hinged to the boom.

[0014] As explained above, the boom bracing system according to the invention is suitable for use with various boom types. For example, an angled or kinked boom, particularly a monoblock boom, may be mentioned. Such booms can be curved in a banana shape or be angled or kinked. Due to the multi-part design of the boom bracing system, it is possible to configure it with a suitable angular offset; that is, the bracing elements are connected to each other at a certain angle, so that the bracing can be guided at an ideal distance along the boom axis to optimize the distance between the centroid of the boom system and the bracing. In particular, the distance between the bracing and the neutral axis of the monoblock boom is adjusted as required, so that an ideal reduction of the bending moment can be achieved.

[0015] The uppermost tension element of the boom bracing can be hinged at the top of the boom. It can be advantageous to hinge the uppermost tension element at the boom's connecting assembly to a stick of the machine attached to that assembly. Hinging the uppermost tension element directly at the stick is also conceivable.

[0016] As explained above, a corresponding energy recovery cylinder can be provided. This can serve as an additional lifting actuator for the boom system. The lifting actuator can preferably be designed either as a hydraulic cylinder connected to a hydraulic accumulator. Energy storage takes place in the compressible medium within the accumulator. Alternatively, the lifting actuator can be designed as a cylinder containing a compressible medium for energy storage.

[0017] Such a lifting actuator, preferably a hydraulic cylinder, is articulated to both the slewing platform and the boom, pushing the boom upwards during lifting. When lowering the boom system, the lifting actuator can utilize the resulting pressure buildup for energy recovery. Due to the use and mounting of the actuator lever on the slewing platform, a better adaptation of the energy recovery system's moment characteristic around the boom's pivot point on the superstructure is possible. The maximum moment of the energy recovery system's characteristic curve occurs at the kinematically optimal boom slew angle.

[0018] The at least one connecting lever for linking the multi-section boom bracing can be directly articulated to the boom. Alternatively, the connecting lever can be articulated to a bearing axis of the aforementioned lifting actuator. If the boom optionally includes a stick with a separate stick actuator for operating the stick, at least one connecting lever (for connecting the upper tensioning elements) can be mounted at the bearing point of the stick cylinder.

[0019] According to the invention, the at least one connecting lever is attached to a boom cross tube, i.e., a tube that extends transversely to the luffing axis through the boom box and typically exits at the side walls of the boom system. Boom cross tubes are often used to improve the transmission of actuator forces, e.g., from a lifting or stick actuator, into the boom structure. The laterally exiting section of the cross tube can then form suitable bearing points for attaching the at least one connecting lever. It is advantageous to form suitable tabs on the cross tube, particularly in the exit area. The tabs are perpendicular to the tube's circumference and allow for easy attachment of the connecting lever.

[0020] According to a particularly preferred embodiment of the invention, at least two parallel boom bracing systems are provided. In this context, "parallel" means running side by side and is not to be understood in a strictly geometric sense. Each of the at least two parallel boom bracing systems can be configured as described above, i.e., equipped with at least one actuator lever and at least one associated actuator. The parallel boom bracing systems can be assembled from multiple tension elements, which are themselves supported relative to the boom by connecting levers. The connection of the connecting levers to the boom is advantageously identical for both boom bracing systems. It is also highly advantageous if the bracing systems run slightly offset laterally from the boom's luffing axis, thereby creating a spatial or...Lateral bracing can be achieved to compensate for any lateral moments.

[0021] It is particularly advantageous if the boom stays or their tension elements are routed above the side plates of the boom cross-section. This results in the distance, calculated parallel to the luffing plane, between the centroid of the tension element and the centroid of the boom being greater than the distance between the top chord of the boom and the centroid of the boom box. Similarly, the distance, calculated perpendicular to the luffing plane, between the centroid of the tension element and the centroid of the boom box is greater than the distance between the side plates of the boom and the centroid of the boom box.

[0022] Further advantages and features of the invention will be explained in more detail below with reference to the exemplary embodiments shown in the drawings. The drawings show: Figure 1: a side view of the boom on a working machine according to a first embodiment, Figure 2: a working machine according to a second embodiment, Figure 3: a third embodiment of the working machine, Figure 4: a fourth embodiment of the working machine, Figure 5: a modification of the working machine according to one of the embodiments of the Figures 1 - 4 Figure 6: a further modification of the embodiments according to Figures 1-4, Figure 7: a further modification of the embodiments according to Figures 1-4, Figure 8: a further modification of the embodiments according to the Figures 1 - 4 Figures 9a, 9b: a modification according to the invention of the embodiments as shown in the Figures 1 - 4 Figure 10: a further modification according to the invention of the embodiments as shown in the Figures 1 - 4 Figure 11: a further modification according to the invention of the embodiments as shown in the Figures 1 - 4Figure 12: a sectional view through the boom system including the bracing according to an embodiment with at least two parallel bracing elements; Figure 13: a further modification of the embodiment according to the Figures 1 - 4 .

[0023] The basic idea of ​​the present invention can be clearly illustrated using the first embodiment of the Figure 1 explaining, which represents a part of the inventive machine in the form of a material handler. Visible here is the box-shaped monoblock boom 1, which is pivotally connected at its end to a rotary platform 2 of the upper carriage of the machine. The neutral fiber of the boom is in Figure 1and in the subsequent figures always designated 1a. At the upper end of the boom 1, a stick 3 is pivotally connected relative to the boom 1; the pivoting movement is effected by an actuator, e.g., a stick cylinder 6. The stick 3 carries a working device in the form of a gripper 4 at its end. According to the invention, the boom 1 is now braced by a guy wire 10 in order to reduce the bending moment introduced into the boom 1 due to the load and thus further increase the load-bearing capacity of the handling device.

[0024] The bracing 10 according to the first embodiment of the Figure 1It consists of a single tension element 11, e.g., a guy rod, which is pivotally mounted at the pivot point 12 at the upper end of the boom head. Alternatively, the tension element can be a cable or chain. The turntable-side end of the tension element 11 is pivotally attached to the free end of an actuator lever 13. One or more actuators in the form of a hydraulic cylinder or energy recovery cylinder 14 are attached to the same end of the at least one actuator lever 13. Specifically, the actuator 14 is fixed to the turntable, and the eye of the piston rod is pivotally mounted on the actuator lever.

[0025] Furthermore, the actuator lever 13 is rotatably mounted on the turntable 2 about a horizontal axis. In the embodiment shown here, the cylinder 14 is configured for pulling, meaning that a retraction movement of the piston rod leads to an increase in the tensile stress in the bracing 10. The resulting upward rocking motion of the boom 1 is supported by at least one lifting cylinder 5, which is connected to the boom 1 and to the turntable 2. An extension movement of the lifting actuator 5 supports the upward rocking motion; at the same time, however, the cylinder 5 can be used for energy recovery by retracting the cylinder rod during the lowering of the boom 1 due to the boom's own weight, thus compressing the corresponding compressible medium (gas) for energy storage.

[0026] One of the Figure 1 A different embodiment is shown in Figure 2 shown. The only change compared to the Figure 1The feature is that the bracing is designed in multiple parts and consists of several individual tension elements 11a, 11b. The lower tension element 11a is connected to the upper tension element 11b via a connecting lever 15, the lever 15 being pivotally mounted on the boom 1 and both tension elements 11a, 11b pivotally attached to its free end.

[0027] Figure 3 clarifies that the exemplary embodiment of the Figure 2 It can also be used without problems for other boom types with different boom shapes. The boom 1' shown there is also designed as a box-shaped monoblock, but with an angled or kinked longitudinal profile. Due to the two-part design, the bracing can perfectly follow the neutral fiber of the monoblock 1'. The individual elements 11a, 11b are connected via the connecting lever 15 with a certain angular offset.

[0028] Figure 4Figure 1 shows a further variation of the boom shape. Here, the boom is shaped as a banana-shaped mono boom 1. In this case, the guying is designed in three parts with guying elements 11a, 11b, and 11c. Due to the three-part design of the guying, an additional connecting lever 16 is required.

[0029] The following Figures 5 to 13 show modifications of the presented embodiments of the Figures 1 - 4 As already explained above, the statements of Figures 1 - 4 The kinematics of the actuator lever 13 and actuator 14 are executed in a pulling manner. Alternatively, the kinematics could also be, as in Figure 5As depicted, the action is realized by pressing. In this case, one end of the actuator lever 13' is connected to the actuator 14', while the opposite end of the lever is connected to the lowest tension element 11. The lever 13' is supported via a pivot point located between the aforementioned connection points, which here is closer to the connection point of the actuator 14'. Lifting the working equipment, i.e., rocking the boom 1, is then achieved by extending the rod of the actuator 14'.

[0030] Figure 6 Figure 1 shows a detailed view of the linkage of the stick 3 to the boom 1. In this modification, the uppermost tension element 11, 11b, 11c is connected to the bearing axis of the stick 3 at the boom head.

[0031] The execution of the Figure 7 This concerns a modified linkage of the actuator lever 13 on the turntable 2. Here, the linkage point is chosen so that it falls exactly on the bearing point of the boom 1 on the turntable 2.

[0032] According to the modification from Figure 8 It is proposed to link at least one connecting lever 15 in the area of ​​the bearing point of the lifting cylinder 5 on the boom 1, i.e. at the bolting there.

[0033] According to Figure 9a A different embodiment according to the invention is proposed. Here, an existing boom cross tube 17 is used, which is usually employed to introduce the forces of the lifting actuator 5 into the boom system 1. The boom tube 17 runs transversely to the boom longitudinal axis in the horizontal direction and opens onto the side walls 1b, 1c (see figure). Figure 9b ) of the box-shaped boom 1. Mounting lugs 18 are formed on the circumference of the protruding pipe section, which serve for bolting to the connecting lever 15. Position 11 shows tension elements in section.

[0034] The Figures 10 and 11The figures show corresponding modifications according to the invention for the connection of the uppermost connecting lever 15, 16, which is to be pivoted here in the area of ​​the bearing axis of the stem cylinder 6. If a corresponding boom cross tube 17 is also provided there, it is to be designed equivalently to the design of the Figure 9b for connecting the connecting lever 15, 16 ( Figure 11 ).

[0035] Figure 13 shows another modification to Figure 6 , in which the uppermost pull element 11b, 11c is directly connected to the stem 3.

[0036] The Figure 12 Figure 1 shows an improved version of the working machine, which now has not a single bracing but instead two parallel and identically designed bracings 10a, 10b. Each of these bracings is designed according to one embodiment of the Figures 1 to 11or 13. However, for the parallel bracing 10a, 10b, it is crucial that the distance b of the tension element's centroid to the jib box's centroid is greater than the distance a of the jib box's upper chord 1e to the jib box's centroid. The same applies to the lateral distance d of the tension element's centroid to the jib box's centroid, which is greater than the distance c of the side walls 1b, 1c of the jib 1 to the jib box's centroid. Spatial bracing allows not only bending moments but also lateral moments to be compensated.

Claims

1. A working machine, in particular material handling machine, comprising a turntable (2), a boom (1) and a boom bracing (10) to be actuated by means of at least one actuator (14), wherein the at least one actuator (14) is operatively connected to the boom bracing (10) by means of an actuator lever (13) rotatably articulated to the turntable (2), in order to introduce the required tensile force into the bracing (10), characterized in that the working machine includes a dipper arm (3) pivotally articulated to the boom (1), wherein the multipart boom bracing (10) consists of two or more tension elements (11a, 11b) which are connected to each other and to the boom (1) by means of at least one connecting lever (15) attached to the boom (1), and wherein the one or more connecting levers (15) is / are rotatably or firmly articulated to the boom (1) and the at least one connecting lever (15) is articulated to a boom transverse tube (17), in particular to a transverse tube for introducing the lifting actuator forces or the dipper arm actuator forces into the boom (1).

2. The working machine according to claim 2, characterized in that the boom (1) is a bent or angled or kinked boom and the multipart boom bracing (10) includes corresponding angular offsets between the tension elements (11a, 11b) in order to follow the bent or angled course of the boom (1).

3. The working machine according to any of the preceding claims, characterized in that the at least one uppermost tension element of (11a, 11b) the boom bracing (10) is articulated to the connection assembly between boom (1) and dipper arm (3), in particular to one or more bolt connections, or alternatively directly to the dipper arm (3).

4. The working machine according to any of the preceding claims, characterized in that at least one additional lifting actuator (5) is provided, which is articulated to the turntable (2) and to the boom (1) and pushes the boom (1) upwards during lifting.

5. The working machine according to claim 4, characterized in that the at least one connecting lever (15) is articulated to the bearing axle of the lifting actuator (5) or of a dipper arm actuator at the boom (1).

6. The working machine according to any of the preceding claims, characterized in that the connection between connecting lever (15) and boom transverse tube (17) is effected by means of at least one tab (18) integrally molded to the outer circumference of the boom transverse tube (17).

7. The working machine according to any of the preceding claims, characterized in that the actuator lever (13) is articulated to the connection assembly, in particular bolt connection, between boom (1) and turntable (2).

8. The working machine according to any of the preceding claims, characterized in that there are provided at least two boom bracings (10a, 10b) extending in parallel, wherein each of the bracings (10a, 10b) can be actuated by means of one or more actuator / actuator lever combinations and possibly comprises a plurality of tension elements (11) connected by means of a connecting lever.

9. The working machine according to claim 8, characterized in that the boom bracings (10a, 10b) or their tension elements (11) are guided in a luffing direction above the side cheeks of the boom cross-section.

10. The working machine according to any of the preceding claims, characterized in that the bearing points of the actuator (14) and connecting lever (15) at the turntable (2) are chosen independently of the type and order of magnitude of the boom system so that they can be used for different boom types and sizes.