Tool, in particular wheel loader

Abstract

The invention relates to a work machine, in particular a wheel loader, with a hydraulic circuit and a lifting frame with Z-bar linkage. The lifting frame comprises a lifting arm, which is pivotable about a horizontal pivot axis, and a deflection lever articulated to a connecting part, which is pivotally connected to the lifting arm about a horizontal pivot axis. The lifting frame further comprises an attachment frame to which an attachment can be reversibly mounted and which is pivotally connected to the front end of the lifting arm, spaced apart from the pivot axis, and to the connecting part about two parallel pivot axes. The attachment frame has a hydraulic coupling part which, by attaching an attachment to the attachment frame, can be automatically and reversibly coupled to a hydraulic coupling part on the attachment side, thereby establishing a hydraulic supply to the attachment.The hydraulic coupling component is connected to the hydraulic circuit via at least two hydraulic lines, the hydraulic lines being flexible at least in sections. According to the invention, the hydraulic lines are attached to the deflection lever via a first suspension that is rotatably connected to the deflection lever about a horizontal axis of rotation.

Description

[0001] The present invention relates to a working device, in particular a wheel loader, according to the preamble of claim 1.

[0002] For many implements, it is common practice to use quick-coupling systems for the quick and uncomplicated attachment of hydraulically operated work tools. These systems are equipped with a hydraulic coupling that automatically establishes a hydraulic connection between the hydraulic consumers of the attachment and the hydraulic system of the implement upon attachment. Such a fully automatic hydraulic quick-coupling system is disclosed for hydraulic excavators, for example, in EP 1 239 087 A1.

[0003] For work equipment with a lifting frame with Z-kinematics, as is often used on wheel loaders, hydraulic couplings can also be used to quickly and easily attach a hydraulically operated work device or tool, such as a high-tip bucket, to the lifting frame.

[0004] An example of such a wheel loader 1 known from the prior art is shown in Figure 1shown. The wheel loader 1 has a hydraulic circuit and a chassis 2, which in this example comprises a rear carriage and a front carriage connected to it via an articulated joint. A lifting frame 10 with Z-kinematics is attached to the front carriage, at the front end of which a wheel loader bucket 60 is pivotally mounted. The lifting frame 10 comprises a lifting arm 12 which can be pivoted by means of two hydraulic lifting cylinders 5 and is H-shaped in plan view with a cross tube 18 forming the H-web. A deflection lever 14 is articulated to the lifting arm 12 and can be pivoted by means of a hydraulic tilting cylinder 6. The deflection lever 14 is articulated at the front end (i.e. facing away from the chassis) to a connecting part 16 (also called a connecting plate). The lifting frame 10 further comprises an attachment frame 20 to which an attachment 60 (in this example the wheel loader bucket 60) can be reversibly mounted.The attachment frame 20 is hinged to the front end of the lifting arm 12 and to the end of the connecting part 16 facing away from the deflection arm 14 about two parallel horizontal axes and can be pivoted by pivoting the deflection lever 14 relative to the lifting arm 12 by means of the tilt cylinder 6. A hydraulic coupling for providing a hydraulic supply to the attachment 60 can be arranged on the attachment frame 20. The attachment frame can also be a quick coupler.

[0005] This special kinematics and the movement paths of the individual components resulting from a movement of the mast affect the hydraulic lines that have to be laid from the hydraulic circuit of the work equipment to the front attachment frame or a hydraulic coupling arranged there and therefore poses a challenge for the integration of a fully automatic hydraulic coupling device. In particular, due to the large traversable angular ranges of the bell crank and the attachment frame, sufficiently long hydraulic lines must be available.

[0006] The hydraulic lines are typically routed via fixed suspensions or attachments along the lift arm and / or the bell crank to the front end of the lift arm or to the connecting link, as the latter pivots less than the attachment frame. This requires additional hydraulic hoses and connections to route and connect the hydraulic lines to the attachment in a small, segmented manner, increasing costs, maintenance effort, and the risk of leaks.

[0007] In addition, the hydraulic hoses must be long enough to ensure that sufficient hose length is available even in extreme positions of the mast, particularly when the attachment or attachment is fully swiveled in and out. In less extreme positions, this results in hose bulges that can protrude into the work area and require additional, complex protective measures such as steel hose coils. The necessarily exposed position of the hoses in such a case also reduces their service life. The use of swiveling hydraulic connections such as swivel fittings on the hydraulic coupling is also disadvantageous, as this increases costs, maintenance effort and the risk of leaks.

[0008] DE 10 2015 104 187 A1 discloses a wheel loader with a Z-kinematic lifting frame, to which an attachment in the form of a bucket can be mechanically mounted. There is no hydraulic connection. US 2015 / 132095 A1 discloses a work machine with a lifting arm that can be pivoted about a horizontal pivot axis, at the end of which an attachment frame for attaching an attachment is pivotably mounted. A hydraulic coupling is located on the lifting arm, from which hydraulic lines run along the lifting arm to the supporting structure of the work machine.

[0009] Against this background, the present invention is based on the object of providing a work tool with a lifting frame with Z-kinematics that enables a fast and fully automatic hydraulic connection of an attachment to the hydraulic circuit of the work tool. The required hydraulic line system of the work tool should be simple and cost-effective and be characterized by a low risk of leakage.

[0010] According to the invention, this object is achieved by a work device having the features of claim 1. Accordingly, the work device according to the invention, which is in particular a wheel loader, comprises a hydraulic circuit and a lifting frame with Z-kinematics. The lifting frame comprises a lifting arm, which can be pivoted about a horizontal pivot axis, and a reversing lever, which is articulated to a connecting part and pivotably connected to the lifting arm about a horizontal pivot axis. Preferably, the lifting arm is pivotable by means of at least one lifting cylinder, and the reversing lever is pivotable by means of at least one tilting cylinder.

[0011] The lifting frame further comprises an attachment frame to which an attachment can be reversibly mounted and which is pivotably connected to the front end of the lifting arm, spaced from the pivot axis, and to the connecting part about two parallel pivot axes. The attachment frame has a hydraulic coupling part which, by attaching an attachment to the attachment frame, can be automatically and reversibly coupled to a hydraulic coupling part on the attachment side, thereby establishing a hydraulic supply to the attachment. The hydraulic coupling part is connected to the hydraulic circuit of the work device via at least two hydraulic lines, with the hydraulic lines being designed to be flexible, at least in sections.

[0012] According to the invention, the hydraulic lines are attached to the bell crank via a first suspension which is connected to the bell crank so as to be rotatable about a horizontal axis of rotation.

[0013] The pivoting bearing of the first suspension on the rocker arm allows the hydraulic lines to be optimally aligned in any position of the mast. This eliminates the need for excessive hydraulic line lengths, which can lead to annoying bulges or even protrude into the work area in certain positions. Instead, the entire lift and tilt range can be traversed without protruding hydraulic lines or those subject to high tensile stress, which protects the hydraulic lines and extends their service life.

[0014] Furthermore, the rotatable first suspension according to the invention enables a direct connection of several hydraulic lines to a fully automatic hydraulic quick coupling, in this case to the hydraulic coupling part, which significantly simplifies and accelerates the attachment process. Because one of the suspensions of the hydraulic lines is designed to be rotatable, the hydraulic lines can be connected to the hydraulic coupling part via fixed connections, which is more cost-effective and less prone to leaks than pivoting hydraulic connections such as rotary fittings. The rotatability of the first suspension, however, does not affect the hydraulic lines fastened in or through it or connected to it, since there is no movement of individual hydraulic line sections relative to one another, but rather a movement or alignment of the hydraulic lines relative to the mast.

[0015] Furthermore, the flexible hydraulic routing according to the invention is independent of the specific quick-coupling or hydraulic coupling system used, since only the coupling-side hydraulic connections may need to be adjusted. Furthermore, the implement according to the invention requires fewer hydraulic line suspensions or fastenings, which reduces costs and maintenance effort. Finally, the hydraulic line routing according to the invention is also suitable for large line or hose diameters, since sharp bends are avoided and the hydraulic lines automatically adapt to the position of the mast.

[0016] Advantageous embodiments of the invention emerge from the subclaims and the following description.

[0017] The hydraulic coupling parts preferably form a hydraulic coupling as disclosed in EP 1 239 087 A1.

[0018] In one embodiment, it is provided that the lifting arm is H-shaped in plan view and has a cross tube forming the H-web, wherein the deflection lever is preferably hinged in a rocker-like manner to a cheek formed on the cross tube.

[0019] In a further embodiment, the first suspension is arranged in the region of the pivot axis of the bell crank, with the rotation axis preferably coinciding with the pivot axis of the bell crank. In the latter case, the first suspension can be mounted on the deflection pin, which forms the pivot axis of the bell crank, with the first suspension being rotatable relative to the deflection pin. By placing the first suspension in the region of the deflection pin, the hydraulic lines can optimally adapt to the movement of the lifting mast, while the attachment point formed by the first suspension is ideally located between the hydraulic coupling part and other possible fixed attachment points of the hydraulic lines on the lifting arm in the direction of its pivot axis. The "range" within the meaning of this invention can be considered, in particular, half the length of the bell crank in both directions.A "range" can also be considered to be within a few centimeters, e.g., 10-15 cm, of the deflection pin. However, it is also conceivable that there are mast geometries where mounting the first suspension at a different location on the deflection lever is advantageous, for example, outside the previously defined range.

[0020] In a further embodiment, the hydraulic coupling part has fixed hydraulic connections to which the hydraulic lines are connected, wherein the hydraulic connections assume a predetermined angle with respect to the hydraulic coupling part. Such fixed hydraulic connections are stable and cost-effective and can be used here due to the adaptability of the alignment of the hydraulic hoses by means of the first suspension, wherein the fixed hydraulic connections can have a certain degree of flexibility or tolerances, for example through the use of spring elements. The angle of the hydraulic connections to the rear surface of the hydraulic coupling part or to the plane passing through the pivot axes of the attachment frame is preferably 90°, but can also have other values ​​and a certain tolerance of, for example, a few degrees. This can also depend on the exact geometry of the lifting frame.

[0021] In a further embodiment, the hydraulic lines are attached to the lifting arm via a second suspension that is permanently connected to the lifting arm. The second suspension is preferably attached or mounted to the cross tube. Alternatively, the second suspension can also be arranged on the inside of the outer struts of the H-shaped lifting arm. The fixed second suspension is simple and cost-effective to implement, for example, as a simple hose clamp or pipe. The adaptability of the hydraulic lines to the position of the lifting mast is already ensured by the rotatable first suspension.

[0022] In a further embodiment, the hydraulic lines between the hydraulic coupling part and the second suspension are connected to the lifting frame only by means of the first suspension, wherein, apart from the first suspension, no further movable, i.e., in particular rotatable, suspensions for attaching the hydraulic lines are preferably provided on the lifting frame. The first suspension is sufficient to ensure optimal adaptability of the alignment of the hydraulic lines. Thus, additional fastenings or suspensions for the hydraulic lines can be dispensed with, which reduces the cost and complexity of the hydraulic line routing.

[0023] In a further embodiment, the first suspension forms a mounting angle with the vertical, which remains essentially constant during movement of the bell crank or the attachment frame while the lifting arm remains stationary. The mounting angle is defined in particular by the angle between the vertical and the plane containing the rotation axis of the first suspension and running perpendicularly through the hydraulic lines at the point closest to the rotation axis. This plane is referred to below as the "first auxiliary plane."

[0024] The mounting angle depends on the position of the lift arm and the length of the hydraulic lines. In a configuration in which a first line section or hydraulic hose is used for each hydraulic line between the hydraulic coupling part and the first suspension, and a second line section or hydraulic hose is used between the first and second suspensions, which are connected to one another via corresponding hydraulic connections of the first suspension, the mounting angle depends on the respective lengths of the line sections or hydraulic hoses. In a configuration in which continuous hydraulic lines are used which are merely held or clamped by the first suspension, the mounting angle depends on the lengths of the line sections on both sides of the first suspension. The mounting angle can therefore be optimally adapted to the geometry of the mast by adjusting the lengths of the line sections orHydraulic hoses must be selected accordingly. This gives the hydraulic line routing according to the invention a high degree of flexibility.

[0025] A configuration of the hydraulic lines, i.e. as described above, in particular the lengths of the line sections or hydraulic hoses, is also possible in which the angle of the previously defined first auxiliary plane to the longitudinal axis of the lift arm, also referred to as the relative mounting angle, remains essentially constant during any movement of the lifting frame, i.e. of the lift arm and / or the bell crank. The relative mounting angle can be between 10 and 80°, preferably between 30 and 60°. With a non-linear geometry of the lift arm, its longitudinal axis can be defined differently to determine the relative mounting angle. For example, the longitudinal axis of the lift arm can be defined as the line lying centrally between the side struts of the lift arm in a plan view, which line runs within the plane that intersects the pivot axis of the lift arm and the lower pivot axis of the attachment frame.Depending on the configuration / geometry of the lifting arm, other definitions may also be useful.

[0026] The above term "substantially constant" means that the mounting angle (or the relative mounting angle) is obviously not completely fixed, but is subject to a certain fluctuation or variation depending on the position of the mast. However, this fluctuation or variation is significantly smaller than the entire angular range of the bell crank or attachment frame. Furthermore, the mounting angle resulting from a specific lift arm position and for a specific choice of hydraulic hose lengths and / or suspension arrangements may also vary slightly due to certain tolerances, such as material and / or manufacturing tolerances.

[0027] In a further embodiment, the variation in the mounting angle during a movement of the bell crank or attachment frame and a simultaneously stationary lifting arm is less than 20°, preferably less than 10°, and particularly preferably less than 5°. In a particularly preferred embodiment, the variation is less than 3°. These values ​​can also apply to the previously defined relative mounting angle. A variation of more than 10° can occur in particular when the first suspension is arranged outside the bell crank, i.e., when the rotational axis of the first suspension does not coincide with the pivot axis of the bell crank.

[0028] In a further embodiment, the hydraulic lines comprise flexible hoses arranged between hydraulic ports and / or hydraulic connections. For the purposes of the present invention, the combinations of hydraulic hoses, ports, and connections can then be referred to as hydraulic lines. The hydraulic lines as a whole (i.e., especially in the area between the hydraulic coupling part and the second suspension) can be designed as continuous hydraulic hoses that are connected to hydraulic ports of the hydraulic coupling part. Alternatively, the hydraulic lines can be composed of several hose sections per line, which are connected to one another, for example, by hydraulic connections. Bulkhead fittings can be used for this purpose.

[0029] In a further embodiment, the first suspension has hydraulic connections, wherein the hydraulic lines between the hydraulic coupling part and the first suspension are designed as flexible hydraulic hoses and connected to the hydraulic connections. The hydraulic connections themselves are fixedly attached to the first suspension and have first connections, which preferably extend in the direction of the hydraulic coupling part. The latter feature means, in particular, that the first connections of the hydraulic connections, when viewed from a plane that perpendicularly intersects the longitudinal axis of the lifting arm and contains the axis of rotation of the first suspension (hereinafter referred to as the "second auxiliary plane"), point to the side of this plane on which the hydraulic coupling part is located.

[0030] In a further embodiment, the hydraulic lines between the first and second suspensions are designed as flexible hydraulic hoses and connected to the hydraulic connections. For this purpose, the hydraulic connections have second connections, which preferably extend toward the second suspension. This again means that the second connections point toward the side of the second auxiliary plane on which the second suspension is located.

[0031] In a configuration in which the hydraulic lines between the hydraulic coupling part and the second suspension are designed as continuous hydraulic hoses, the hydraulic connections are preferably hose feedthroughs, whereby the end regions of the hose feedthroughs on both sides can be considered connections in the previously described sense. In a configuration in which the hydraulic lines between the hydraulic coupling part and the first suspension, on the one hand, and between the first and second suspension, on the other hand, are designed as separate hydraulic hose pieces, the hydraulic connections have actual connections on both sides of the first suspension, to which the hydraulic hose pieces are connected. These are preferably bulkhead fittings.However, it is also conceivable that a combination of hydraulic connection with actual connectors and hose clamps is used, for example with several different hydraulic lines.

[0032] In both cases, the second suspension can include a hose clamp or be designed as such, which represents a particularly simple design. Alternatively or additionally, hydraulic connections with connectors to which the hydraulic hoses are connected can also be used.

[0033] InIn a further embodiment, the hydraulic connections pointing in the direction of the hydraulic coupling part and / or the second suspension are angled, in particular angled downwards in the direction of the lifting arm, so that the hydraulic hoses are connected to the first suspension at a predetermined angle, regardless of the movement of the lifting mast. In particular, it is the previously described connections of the hydraulic connections that are angled. However, correspondingly angled hose feedthroughs can also be used here. As a result, the end regions of the hydraulic hoses adjacent to the connections always assume a specific angle to the first auxiliary plane, which corresponds to the angle of the connections of the hydraulic connections. The angle can be 45°, for example.

[0034] The angled hydraulic connections prevent uncontrolled bulging of the hydraulic hoses when the mast moves, particularly in the area between the hydraulic coupling and the first suspension. Without a specified angle by the hydraulic connections, uncontrollable and irreversible bulging of the hydraulic hoses can occur in this area, especially near the first suspension. Such an unintentional change in direction can occur spontaneously or be caused, for example, by a pressure surge in a hydraulic line. This can lead to damage to the hydraulic hoses, for example, through contact with nearby components, and to chafing and kinking.

[0035] In a further embodiment, the hydraulic hoses in the area of ​​the hydraulic connections of the first suspension have a curvature with a constant sign, regardless of the movement of the mast. In particular, the hydraulic hoses in the area of ​​the first suspension have a bulge directed downwards or toward the lift arm, which points in the same direction regardless of the movement of the mast and thus always has a uniform (i.e., negative or positive - depending on the definition or viewing direction) curvature, the magnitude of which, however, depends on the position of the mast. "Curvature" refers in particular to the mathematical curvature in a lateral view of the work equipment or the hydraulic hoses.

[0036] The hydraulic hoses in the area of ​​the hydraulic connections of the hydraulic coupling part, on the other hand, preferably have a curvature whose sign varies with the movement of the lifting mast. This means that, depending on the position, particularly of the attachment, the hydraulic hoses curve upwards or downwards away from the hydraulic connection of the hydraulic coupling part. For example, with a wheel loader bucket tilted downwards, the hydraulic hoses curve downwards, and with a wheel loader bucket tilted upwards, they curve upwards toward the first suspension. This ensures that the spatial routing of the hydraulic hoses is always defined and prevents unwanted changes in direction.

[0037] In a further embodiment, the hydraulic lines in the area between the hydraulic coupling part and the first suspension are located above a lower edge of the working device, regardless of the position of the lifting mast. The lower edge is in particular the lower edge of the attachment frame, although it can also be a lower edge of an attachment. This ensures that the hydraulic lines never touch the ground or protrude into the working area of ​​the working device and thus become damaged. The smallest distance of the hydraulic lines to the ground, which is also referred to as sag, is particularly small when the lifting arm is lowered and the attachment frame or attachment is tilted in. The sag is preferably greater than 5 cm, particularly preferably greater than 10 cm, in order to have a sufficient safety distance from the ground.

[0038] In a further embodiment, the attachment frame has two hydraulic coupling parts which can be automatically and reversibly coupled to two attachment-side hydraulic coupling parts by attaching an attachment to the attachment frame, thereby establishing a hydraulic supply to the attachment. A hydraulic supply using two hydraulic coupling parts can be advantageous, for example, for an attachment with multiple hydraulic consumers, such as a high-tip bucket with a hydraulic hold-down device. Each hydraulic coupling part is connected via at least two hydraulic lines to a separate or a shared hydraulic circuit of the work device in order to supply the various consumers of the attachment. If the hydraulic coupling parts are connected to a shared hydraulic circuit, the supply to the individual consumers can be controlled via hydraulic valves in the hydraulic circuit.

[0039] Preferably, a separate first suspension and a separate second suspension are provided for each hydraulic coupling part, which are arranged, particularly in a plan view of the lifting frame, on opposite sides of the longitudinal axis of the lifting arm, i.e., to the right and left of it but at the same height. It can be provided that the axes of rotation of the two first suspensions coincide and, furthermore, preferably coincide with the pivot axis of the reversing lever.

[0040] All of the previously described embodiments apply to such an arrangement of multiple hydraulic coupling parts, each with multiple first and optionally second suspensions. A different number of hydraulic lines, possibly with different shapes or diameters and possibly with different material properties such as stiffness, can be connected to each of the hydraulic coupling parts. For example, one of the hydraulic coupling parts can be connected to two hydraulic lines and the other hydraulic coupling part can be connected to three hydraulic lines. In the latter case, the three hydraulic lines are held by the associated first and second suspensions. Each of the hydraulic couplings is preferably formed by a hydraulic coupling block, as disclosed in EP 1 239 087 A1.

[0041] In a further embodiment, the pivot axes of the attachment frame simultaneously serve as the locking axes for locking the attachment, i.e., the attachment frame is connected and locked to the attachment frame via the pivot axes. This results in a connection between the attachment frame and the attachment frame without any extension dimension or attachment height, which increases the maximum load-bearing capacity of the implement. In particular, the attachment frame is a quick coupler without any extension dimension, i.e., without any attachment height. The combination of a quick coupler without any extension dimension and a fully automatic hydraulic quick coupling is only made possible and significantly easier by the flexible hydraulic line routing according to the invention.

[0042] Further features, details, and advantages of the invention will become apparent from the exemplary embodiments explained with reference to the figures. They show: Figure 1: an example of a wheel loader known from the prior art in a perspective view; Figure 2: the lifting frame of the work device according to the invention according to an embodiment in a first position in a schematic side view; Figure 3: the lifting frame according to Figure 2 in a second position; Figure 4: the lifting frame according to Figure 2 in a third position; Figure 5: a schematic visualization of the mounting angle and the variance of the mounting angle; Figure 6: the deflection lever including the first suspension of the working device according to the invention according to an embodiment in a perspective exploded view; Figure 7: the lifting frame of the working device according to the invention according to an embodiment in a lateral cross-sectional view; Figure 8: the lifting frame according to Figure 7 in a plan view; Figure 9: an enlargement of the hydraulic coupling of the embodiment according to Figure 7in a side cross-sectional view; Figure 10: the lifting frame according to Figure 7 in a further position with the lifting arm upright; and Figure 11: the lifting frame according to Figure 7 in another position with the lifting arm lowered.

[0043] The Figure 1 shows a wheel loader 1 known from the prior art with a lifting frame in Z-kinematics according to the preamble of claim 1, wherein the hydraulic coupling and the hydraulic lines are not shown here. Figure 1 has already been described at the beginning, so that a repeated description can be omitted at this point. The exemplary embodiments of the working device according to the invention described below are based on a wheel loader 1 as shown in Figure 1 However, it can also be any other implement with a Z-kinematic mast.

[0044] The Figures 2-4show schematic side views of the front part of the work device 1 according to the invention as longitudinal sections through the lifting frame 10 in three different positions of the lifting frame 10. The lifting arm 12, which can be pivoted by means of the lifting cylinders 5 (not shown here), is pivotally connected to the front carriage of the work device 1 about a horizontal pivot axis A. The deflection lever 14 is pivotally connected to a cheek 19 formed on the cross tube 18 about a horizontal pivot axis B. The attachment frame 20 is pivotally connected both at the front end of the lifting arm 12 about a horizontal pivot axis C and at the front end of the connecting part 16 about a horizontal pivot axis D. The pivot axes A, B, C and D as well as the cross tube 18 run parallel to one another. The reference number 4 designates one of the front wheels of the work device 1.By actuating the tilting cylinder 6, the deflection lever 14 is pivoted about the pivot axis B, whereby in turn, due to the coupling by the connecting part 16, the attachment frame 20 and thus also the attachment 60 are pivoted or tilted about the pivot axis C.

[0045] The attachment frame 20 is designed as a quick-coupling part of a quick-change device, by means of which an attachment 60 (in the present embodiment, a wheel loader bucket) can be quickly and easily reversibly mounted. For this purpose, an attachment-side quick-coupling part is mounted on the attachment 60, which can be engaged and locked with the quick-coupling part or attachment frame 20 on the work tool side. The quick-coupling part or attachment frame 20 has no projection dimension or no mounting height, wherein the pivot axes C and D simultaneously serve to fasten and lock the attachment 60. In contrast, a quick coupler with mounting height or projection dimension would mean that the pivot axes C and D of the attachment frame 20 and the locking axes to which the attachment 60 can be fastened are separate, i.e., are spaced apart from one another.However, this results in a larger lever arm, which has a negative effect on the maximum load capacity of the working device 10.

[0046] In order to quickly and easily establish a hydraulic supply to the attachment 60 during installation of the attachment 60 (for example, when using a high-tip bucket as the attachment 60), a hydraulic coupling part 22 is arranged on the attachment frame 20. This hydraulic coupling part interacts with a corresponding hydraulic coupling part 21 on the attachment side during installation of the attachment 60. This creates a fully automatic hydraulic connection when the attachment 60 is installed. For this purpose, the hydraulic coupling part 22 is connected to the hydraulic circuit of the work device 1 via several hydraulic lines 50.

[0047] For this purpose, the hydraulic coupling part 22 has hydraulic connections 24, to which flexible first hydraulic hoses 52 are connected. The hydraulic connections 24 are firmly connected to the hydraulic coupling part 22 and form a fixed angle of, for example, 90° to its rear wall or to a plane passing through the pivot axes C and D. The first hydraulic hoses 52 are attached at the other end to the reversing lever 14 via a first suspension 30 to achieve a flexible and defined hose routing.

[0048] In particular, the two hydraulic coupling parts or halves 21, 22 couple from a circular movement due to a corresponding circular movement when connecting the attachment 60 to the attachment frame or the quick coupler 20. This is the case, for example, with a hydraulic coupling such as that described in EP 1 239 087 A1. In such a case, with regard to the coupling taking place from a circular movement, it can be advantageous if the fixed hydraulic connections 24 have a certain angular tolerance, for example 90° ± a few degrees. This can be achieved, for example, with flexible elements such as springs. Alternatively or additionally, it can be provided that after the circular movement has ended during the coupling, the two hydraulic coupling parts 21, 22 are brought together linearly, for example by means of an actuator.

[0049] The first suspension 30 is mounted on the bell crank 14 so as to be rotatable about a rotation axis E, wherein the rotation axis E coincides with the pivot axis B. For this purpose, the first suspension 30 is attached to the deflection pin of the bell crank 14 forming the pivot axis B and is mounted so as to be freely rotatable relative to it (see Figure 6 ). The first suspension 30 has hydraulic connections 32, 34 located on both sides of the Figures 2-4 drawn first auxiliary plane H. The sections of the hydraulic connections arranged on the side of the hydraulic coupling part 22 are designated 32 and the sections arranged on the other side are designated 34. In this exemplary embodiment, the hydraulic connections 32, 34 are designed as bulkhead screw connections and therefore have connections 32, 34 on each side of the plane H. The first hydraulic hoses 52 are connected to the connections 32 of the hydraulic connections 32, 34.

[0050] Second flexible hydraulic hoses 54 are connected to the opposite connections 34 of the hydraulic connections 32, 34 and extend to a second suspension 40, via which the second hydraulic hoses 54 are firmly connected to the lifting arm 12. The second suspension 40 is fixed, ie immovably mounted on the outside of the cross tube 18 of the lifting arm 12, in this embodiment in the upper area of ​​the cross tube 18 facing the pivot axis A. Starting from the second suspension 40, the hydraulic lines 50 are directed to lines not specified in more detail here and in the Figures 2-4connected to the hydraulic circuit of the working device 1 in a manner indicated by two parallel lines. The placement of the second suspension 40 can influence (apart from the hose lengths used), in particular, the paths of the first and second hydraulic hoses 52, 54 as well as the position, ie, in particular the mounting angle, of the first suspension 30. In other words, the second hydraulic hoses 54 hold the first suspension 30 or the first hydraulic hoses 52 in the desired position.

[0051] The connections of the hydraulic connections 32, 34, ie the projecting ends of the bulkhead screw connections, are opposite the first auxiliary plane H (ie in the Figures 2-4downwards in the direction of the lifting arm 12), for example by 45°. This determines the direction in which the hydraulic hoses 52, 54 run in the area of ​​the first suspension 30, so that unwanted or uncontrolled bulging or inversion of the hydraulic hoses 52, 54, in particular of the first hydraulic hoses 52, cannot occur. Such unwanted and potentially irreversible inversion 53 of the first hydraulic hoses 52 is Figure 4 Alternatively, the hydraulic connections 32, 34 can be straight and the ends or connections of the hydraulic hoses 52, 54 can be angled.

[0052] The free rotation of the first suspension 30, the fixed hydraulic connections 24 on the hydraulic coupling part 22, the angled design of the hydraulic connections 32, 34, and the second suspension 40 fixedly arranged on the cross tube 18 create a flexible hydraulic hose guide that allows multiple hydraulic lines 50 to be connected to a fully automatic hydraulic coupling, reduces the number of required fastenings, provides a defined and therefore gentle hose guide, and eliminates the need for movable hydraulic couplings or connections or rotary fittings that are prone to leaks. Depending on the position or movement of the lifting frame 10, the freely rotatable first suspension 30 automatically aligns itself so that sufficient hose length is always available without kinks or excessively small curvature radii in the hydraulic hoses 52, 54.In addition, the controlled hydraulic hose movement provides the operator with a better view of the working area of ​​the work device 1, since the hydraulic lines 50 do not protrude as far into the working area.

[0053] To illustrate this flexible adaptability of the hydraulic guide according to the invention, the Figures 2-4 The lifting frame 10 is shown in three different positions, in which the lifting arm 12 remains in a lowered position and the attachment frame 20 or attachment 60 is tilted into different positions by pivoting the bell crank 14. As can be seen, the angle of the first auxiliary plane H relative to the vertical V, which is also referred to as the mounting angle α, remains essentially the same. The rotation of the bell crank 14 is thus compensated by the rotatably mounted first suspension 30.

[0054] The mounting angle α depends on the lifting / tilting position of the lifting arm 12 as well as on the hose lengths of the hydraulic hoses 52 and 54 and is set to a specific value α for a specific position of the lifting arm 12 depending on the selected hose lengths. This results in a certain tolerance in the selected length of the first hydraulic hoses 52, which is Figure 4 designated by the reference symbol x. This tolerance can be approximately 20% of the hose length of the first hydraulic hoses 52. Furthermore, the length of the second hydraulic hoses 54 can also be varied. By varying the lengths of the first and / or second hydraulic hoses 52, 54, the mounting angle α can be flexibly adapted to the conditions.

[0055] During operation, ie when the mast 10 is moving, the mounting angle α varies only by a few degrees, as shown in the Figure 5This shows the very small variation Δα of the mounting angle α when pivoting the attachment frame 20, which can amount to only a few degrees (e.g., approximately 5° or 3°) compared to the entire movable angle range of the attachment frame 20 or the deflection lever 14. Reasons for the variation Δα can also be fluctuating material parameters (diameter, stiffness, etc.) and hose lengths. In particular, the mounting angle α exhibits the greatest deviations at the inward and outward tipping end positions of the attachment 60 or the attachment frame 20.

[0056] While the mounting angle α is only relevant for a specific position of the lifting arm 12 (such as the position shown in the Figures 2-4 shown lowered position) remains substantially constant, the above-described relative mounting angle, which is defined with respect to the lifting arm 12, ie its longitudinal axis, does not substantially change regardless of the lifting arm position.

[0057] Due to the hydraulic hose guide according to the invention, the sign of the curvature of the first hydraulic hoses 52 remains constant in the area of ​​the hydraulic connections 32 of the first suspension 30. Thus, in the Figures 2-4 It can be seen that the first hydraulic hoses 52 bend to the left in each position towards the attachment frame 20. In contrast, the sign of the curvature changes in the area of ​​the fixed hydraulic connections 24 on the hydraulic coupling part 22. In the Figures 2 and 3 the first hydraulic hoses 52 bend to the left or upwards towards the lower edge of the lifting arm 12, while in the Figure 4 , in which the wheel loader bucket 60 is fully tipped out, curve to the right toward the upper edge of the lifting arm 12. In this position, the first hydraulic hoses 52 run in an S-shape, thus undergoing a change in curvature sign. In the positions of the Figures 2 and 3the curvature sign remains the same.

[0058] The optimized hose routing also prevents the hydraulic hoses 52 from touching the ground when the mast 10 is in the lowered position. This is particularly problematic when the attachment 60 is tilted when the lift arm 12 is lowered. This position is Figure 3 As can be seen, the flexible hose routing results in a minimal sag d (i.e., a safety distance from the ground). This sag d is preferably at least 8-10 cm. Preferably, a variance of approximately 20% of the hose length of the first hydraulic hoses 52 results in an equal sag d.

[0059] It can be provided that, apart from the first and second suspensions 30, 40, there is no further fastening of the hydraulic lines 50 on the lifting frame 10. Alternatively, a further fixed fastening of the hydraulic lines 50 can be arranged between the second suspension 40 and the chassis 2 on the lifting arm 12, in particular on an inner side of the H-shaped lifting arm 12. For this purpose, the second hydraulic hoses 54 can extend to this further fastening, being held and fixed by the second suspension 40, which is designed, for example, as a hose clamp.

[0060] Instead of providing separate, i.e., separate first and second hydraulic hoses 52, 54, which are connected to each other via angled bulkhead fittings 32, 34, continuous hydraulic hoses can also be used, with the hydraulic connections 32, 34 then preferably being designed as angled hose feedthroughs or holders. This also allows the continuous hydraulic hoses to be directed in the required direction.

[0061] In the Figure 6An embodiment of the first suspension 30 is shown as an exploded view, in which the hydraulic connections 32, 34 are formed by bulkhead screw connections, which are fastened in a holding plate 36 rotatably mounted relative to the bell crank 14. In the embodiment shown here, it is not the bulkhead screw connections 32, 34 that are angled, but rather the ends of the hydraulic hoses 52, 54 (not shown). Accordingly, the bulkhead screw connections 32, 34 are straight here.

[0062] The retaining plate 36 is attached here by means of a screw connection in the center of the bell crank pin, which forms the pivot axis B of the bell crank 14. The central element is a screw connection or screw 38, which is then provided with a washer or flat washer on an outer screw head and is passed through a bracket 37 fastened to the retaining plate 36. The retaining plate 34 is provided with several (here two) through holes into which the bulkhead screw connections 32, 34 are screwed or enclosed. The number of bulkhead screw connections 32, 34 depends on the number of hydraulic lines 50 to be attached. The hydraulic hoses 52, 54, which are angled in particular at the ends, are screwed onto the protruding ends of the bulkhead screw connections 32, 34. The screw connection 38 is fixed to the deflection bolt, whereby a nut 39 counters the screw connection 38 towards the deflection lever 14 and a further washer or washer is attached.Thus, the bracket 37 can remain movable relative to the deflection lever 14 or deflection bolt due to the arrangement of the washers on both sides and the countered screw connection.

[0063] The Figures 7-8 show the lifting frame 10 and the hydraulic hose guide according to the invention using a concrete embodiment, wherein the Figure 8 a top view of the lifting arm 12 and the Figure 7 a side view along the Figure 8 shows a section labeled a2. The hydraulic lines 50 between the second suspension 40 and the hydraulic circuit of the working device 1 are not shown for reasons of clarity.

[0064] Above, only a single hydraulic coupling or hydraulic coupling part 22 and the hydraulic lines 50 connected thereto (including the corresponding hydraulic connections 24, hydraulic connections 32, 34 and hydraulic hoses 52, 54) were considered. As particularly shown in the Figure 8 As can be seen, this hydraulic arrangement can be arranged on one side of the bell crank 14 (in the Figure 8 This is the left side as seen from cab 3. It can of course be on the other side (i.e. in the Figure 8the right-hand side) a second hydraulic coupling with corresponding hydraulic lines 50 can be provided. The number and material properties (such as diameter, rigidity, etc.) of the hydraulic lines 50 of the second hydraulic coupling can be different from those of the first hydraulic lines 50. The first and second suspensions 30, 40 are in this case preferably arranged on the opposite side of the bellcrank 14, i.e. mirror-symmetrically to the longitudinal axis of the lifting frame 10 or lifting arm 12 or bellcrank 14. Both hydraulic coupling parts 22 can be connected to separate or a common hydraulic circuit of the working device 1. This can be used, for example, in the case of an attachment 60 with several hydraulic consumers (such as a high-tip bucket with hydraulic hold-down device).As hydraulic lines 50, for example, an inlet and a return line can be connected to the first hydraulic coupling part 22, and an inlet, a return line, and a leakage oil line can be connected to the second hydraulic coupling part 22. However, other arrangements are also conceivable in which more than two hydraulic couplings and corresponding hydraulic lines 50 and suspensions 30, 40 are used.

[0065] In the Figure 9 Finally, the area marked with the reference symbol a1 is Figure 7enlargement, showing the connected hydraulic coupling with the implement-side and attachment-side hydraulic coupling parts 21, 22. It can be seen that the hydraulic coupling in this exemplary embodiment comprises a spring 23 and a linear guide, thus ensuring a precisely fitting, trouble-free, and leak-free, fully automatic coupling of the hydraulic coupling halves 21, 22 when the quick-coupling parts are brought together. Regarding the details of this hydraulic coupling, explicit reference is made to the disclosure of EP 1 239 087 A1.

[0066] In the Figures 10 and 11 is this already in Figure 7 The lifting frame 10 shown is shown in two different positions, which differ in the position of the deflection lever 14 as well as in the position of the lifting arm 12. In the Figure 10the lifting arm 12 is in a raised position with the lifting cylinder 5 extended and the tilting cylinder 6 retracted, so that the wheel loader bucket 60 is pivoted downwards. Figure 11 the lifting arm 12, on the other hand, is completely lowered by retracting the lifting cylinder 5, while the tilting cylinder 6 is extended, so that the wheel loader bucket 60 is pivoted upwards.

[0067] In both figures, the respective auxiliary plane H is shown, the angle of which to the vertical V (not shown here) defines the mounting angle α for the respective mast position. As previously described, the mounting angle α remains essentially constant for a specific (fixed) position of the lifting arm 12 during a movement of the deflection lever 14. However, the mounting angle α changes with a movement of the lifting arm 12, resulting in different mounting angles α for different positions of the lifting arm 12.

[0068] This results in a maximum angular range for the mast 10 through which the mounting angle α can travel during a movement of the mast 10. This angular range is defined by the minimum and maximum mounting angles α min and α max in the extreme positions of the mast 10 and depends on the geometry of the mast 10 and the hydraulic hose suspension, i.e. in particular the positions of the first and second suspensions 30, 40 and / or the lengths of the first and second hydraulic hoses 52, 54 used. The value of this angular range |α max - α min | can, for example, be between 80° and 120° or between 90° and 110°. Within this angular range, it follows that for a specific fixed position of the lifting arm 12, a mounting angle α is established which remains essentially constant when only the deflection lever 14 is moved, i.e. in particular only varies by a few degrees Δα.

[0069] In the Figures 10 and 11It can be seen that the angle between the first auxiliary plane H and the longitudinal axis of the lifting arm 12 (not shown), the so-called relative mounting angle, is essentially constant for both mast positions. The longitudinal axis of the non-linearly designed lifting arm can be defined as the line that runs through the pivot axes A and C and, viewed from above, runs centrally between the side struts of the lifting arm 12.

[0070] In the Figures 10 and 11 It is also clearly visible that the curvature of the first hydraulic hoses 52 in the area of ​​the fixed hydraulic connections 24 changes its sign depending on the mast position (in the Figure 10 the first hydraulic hoses 52 are directed downwards and in the Figure 11upwards away from the fixed hydraulic connections 24), while the sign of the hose curvature in the area of ​​the first suspension 30 remains the same (in both figures, the first hydraulic hoses 52 curve to the left away from the first suspension 30). Furthermore, it can be seen that in the Figure 11 In the extreme lifting mast position shown with the wheel loader bucket 60 pivoted upwards and the lifting arm 12 fully lowered, the first hydraulic hoses 52 do not protrude beyond the lower edge of the wheel loader bucket 60 into the working area. List of reference symbols:

[0071] 1Working device 2Vehicle frame 3Driver's cab 4Wheel 5Lift cylinder 6Tipping cylinder 10Lift mast 12Lift arm 14Reversing lever 16Connecting part 18Cross tube 19Chest 20Mounting frame 21Hydraulic coupling part (attachment side) 22Hydraulic coupling part (work device side) 23Spring 24Hydraulic connections 30First suspension 32Hydraulic connection 34Hydraulic connection 36Retaining plate 37Bracket 38Screw connection / screw 39Nut 40Second suspension 50Hydraulic lines 52First hydraulic hoses 53Uncontrolled bulging of the first hydraulic hoses 54Second hydraulic hoses 60Attachment ASwivel axis Lift arm BSwivel axis Reversing lever CSwivel axis Mounting frame dSag DSwivel axis Mounting frame ERotation axis first suspension HFirst auxiliary plane VVertical αMounting angle α min Minimum mounting angle α max Maximum mounting angle

Claims

1. Implement (1), in particular a wheel loader, having a hydraulic circuit and a lifting frame (10) with Z-kinematics, wherein the lifting frame (10) comprises a lifting arm (12) pivotable about a horizontal pivot axis (A), a deflection lever (14) pivotably coupled to the lifting arm (12) about a horizontal pivot axis (B), which deflection lever is coupled in an articulated manner to a connecting part (16), and an attachment frame (20), on which an attachment (60) can be reversibly mounted and that is pivotably articulated about two parallel pivot axes (C, D) to the front end of the lifting arm (12) spaced apart from the pivot axis (A) and to the connecting part (16), wherein the attachment frame (20) has a hydraulic coupling part (22), which can be automatically and reversibly coupled to a hydraulic coupling part (21) on the attachment side by attaching an attachment (60) to the attachment frame (20), thereby producing a hydraulic supply to the attachment (60), and wherein the hydraulic coupling part (22) is connected to the hydraulic circuit via at least two hydraulic lines (50) that are flexible at least in sections, characterised in that the hydraulic lines (50) are attached to the deflection lever (14) via a first suspension (30) fastened to the deflection lever (14) so as to be rotatable about a horizontal axis of rotation (E).

2. Implement (1) according to claim 1, characterised in that the lifting arm (12) is H-shaped and has a transverse tube (18) forming the H-shaped bar, wherein the deflection lever (14) is preferably articulated in a rocker-like manner to a cheek formed on the transverse tube (14).

3. Implement (1) according to claim 1 or 2, characterised in that the first suspension (30) is arranged in the region of the pivot axis (B) of the deflection lever (14), wherein the axis of rotation (E) preferably coincides with the pivot axis (B) of the deflection lever (14).

4. Implement (1) according to any one of the preceding claims, characterised in that the hydraulic coupling part (22) has fixed hydraulic connections (24) to which the hydraulic lines (50) are connected, wherein the hydraulic connections (24) assume a predetermined angle in relation to the hydraulic coupling part (22), wherein the angle is preferably 90°.

5. Implement (1) according to any one of the preceding claims, characterised in that the hydraulic lines (50) are attached to the lifting arm (12) via a second suspension (40) that is connected to the lifting arm (12) in a fixed manner, wherein the second suspension (40) is preferably fastened to the transverse tube (18).

6. Implement (1) according to claim 5, characterised in that the hydraulic lines (50) between the hydraulic coupling part (22) and the second suspension (40) are connected to the lifting frame (10) only by means of the first suspension (30), wherein preferably, apart from the first suspension (30), no further movable suspensions are provided on the lifting frame (10) for fastening the hydraulic lines (50).

7. Implement (1) according to any one of the preceding claims, characterised in that the first suspension (30) forms a mounting angle (α) with the vertical, which remains essentially constant when the deflection lever (14) is moved and the lifting arm (12) is stationary at the same time, wherein the variation of the mounting angle (α) is preferably less than 20°, more preferably less than 10° and particularly preferably less than 5° when the deflection lever (14) is moved and the lifting arm (12) is simultaneously stationary.

8. Implement (1) according to any one of the preceding claims, characterised in that the hydraulic lines (50) comprise flexible hydraulic hoses (52, 54), which are arranged between hydraulic connections (24) and / or hydraulic links (32, 34).

9. Implement (1) according to claim 8, characterised in that the first suspension (30) has hydraulic links (32, 34), wherein the hydraulic lines (50) between the hydraulic coupling part (22) and the first suspension (30) are designed as flexible hydraulic hoses (52) and are connected to the hydraulic links (32), wherein the hydraulic links (32) are preferably hose feed-throughs or bulkhead fittings.

10. Implement (1) according to claims 5 and 9, characterised in that the hydraulic lines (50) between the first and second suspensions (30, 40) are designed as flexible hydraulic hoses (54) and are connected to the hydraulic links (34), wherein the second suspension (40) preferably comprises a hose clamp.

11. Implement (1) according to claim 9 or 10, characterised in that the hydraulic links (32, 34) pointing in the direction of the hydraulic coupling part (22) and / or the second suspension (40) are angled, in particular angled in the direction of the lifting arm (12) such that the hydraulic hoses (52, 54) are connected to the first suspension (30) at a predetermined angle regardless of the movement of the lifting frame (10).

12. Implement (1) according to any one of claims 9 to 11, characterised in that the hydraulic hoses (52) in the region of the hydraulic links (32) of the first suspension (30) have a curvature with a constant sign irrespective of the movement of the lifting frame (10), wherein the hydraulic hoses (52) in the region of the hydraulic connections (24) of the hydraulic coupling part (22) preferably have a curvature, the sign of which varies with the movement of the lifting frame (10).

13. Implement (1) according to any one of the preceding claims, characterised in that the hydraulic lines (50) in the region between the hydraulic coupling part (22) and the first suspension (30) are located above a lower edge of the implement (1), irrespective of the position of the lifting frame (10), wherein the lower edge of the implement (1) is in particular the lower edge of the attachment frame (20) or an attachment (60).

14. Implement (1) according to any one of the preceding claims, characterised in that the attachment frame (20) has two hydraulic coupling parts (22), which can be automatically and reversibly coupled by attaching an attachment (60) to the attachment frame (20) with two hydraulic coupling parts (21) on the attachment side, thereby establishing a hydraulic supply to the attachment (60), wherein each hydraulic coupling part (22) is connected to a separate or a common hydraulic circuit via at least two hydraulic lines (50), wherein preferably a separate first suspension (30) and a separate second suspension (40) are provided for each hydraulic coupling part (22), which in particular are arranged on opposite sides of the longitudinal axis of the lifting arm in a plan view of the lifting frame (10).

15. Implement (1) according to any one of the preceding claims, characterised in that the pivot axes (C, D) of the attachment frame (20) simultaneously represent the locking axes for locking the attachment (60), wherein the attachment frame (20) is, in particular, a quick coupler without a front section.

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