QUICK COUPLING WITH CENTERING DEVICE

Description

[0001] The present invention relates to a quick coupling for coupling a tool to the boom of a working device according to the preamble of claim 1 and to a working device with such a quick coupling.

[0002] Swivel-type quick couplings are widely used on certain work equipment, such as hydraulic excavators, because they allow for easy and quick changing of different tools such as hydraulic grapples, excavation buckets, grabs, and the like. To couple, only one of the quick coupling's two locking axes needs to be positioned and engaged. This can advantageously be a cross pin that is hooked into a hook-shaped eyelet on the opposite quick coupling part. The boom-side quick coupling part can then be swiveled relative to the tool about the already engaged locking pin to find the locking position in which the second locking pin can be locked. The latter is usually formed by a pair of locking pins that can be moved apart laterally and inserted into corresponding locking holes on the opposite quick coupling part.

[0003] To establish a hydraulic connection, such quick couplings can comprise a power circuit coupling or hydraulic coupling, with each of the quick coupling parts having a corresponding power coupling part, which pivot together with the quick coupling parts and are automatically brought together. To compensate for the circular movement of the power coupling parts relative to each other when pivoting the quick coupling parts about the first locking axis, it is known to movably mount one of the two power coupling parts, usually the tool-side power coupling part, for example, on an arrangement of compression springs. However, this often results in an improper coupling, which can lead to oil leakage.

[0004] To eliminate this deficiency of known power circuit couplings and prevent jamming of the connecting connectors of the power coupling parts, EP 1 239 087 A1 proposes providing a linear guide for the power coupling parts, which forces them to move relative to each other along a straight line, counter to the circular pivoting movement. For this purpose, the linear guide on the boom- and tool-side power coupling parts has guide elements that interact during coupling. These elements can be designed, for example, as guide pins and bores that interlock before the connecting connectors are brought together, resulting in a precisely linear relative movement.

[0005] However, this coupling concept only functions flawlessly if the movably mounted energy coupling part does not deviate from a defined center position, in which the guide elements of the linear guide are aligned and can be guided into each other without jamming. This makes it difficult or even impossible to use the quick coupling in applications where the freely mounted energy coupling part is deflected from the center position by its own weight due to the installation position. This problem increases when hoses are connected to the energy coupling part, whose inherent stress further increases the deflection of the energy coupling part from the center position.

[0006] An example of such a problematic installation position is the use of this type of quick coupling on a wheel loader. Unlike on a hydraulic excavator, the installation orientation of the tool-side power coupling part is vertical, i.e. the straight coupling of the power coupling parts via the linear guide takes place along an essentially horizontal line. Due to the weight of the movable power coupling part, it pivots out of the central position due to gravity, so that the guide elements or guide pins and bores are no longer aligned with one another. The deflection of the movable power coupling part makes coupling or engaging the guide elements difficult or even impossible. This can therefore lead to increased wear or damage if the coupling is carried out using force to overcome the offset.

[0007] The present invention is therefore based on the object of overcoming this disadvantage and enabling the use of such a quick coupling regardless of the installation position and situation of the energy coupling parts.

[0008] According to the invention, this object is achieved by a quick-coupling device having the features of claim 1. Accordingly, the quick-coupling device according to the invention, which is provided for coupling a tool to the boom of a work device, in particular a wheel loader, comprises a boom-side and a tool-side quick-coupling part, as well as a power circuit coupling for automatically coupling a tool-side power connection to a boom-side power connection. The quick-coupling parts can be reversibly locked to one another via a pair of spaced-apart locking axes.

[0009] The power circuit coupling comprises a boom-side power coupling part and a tool-side power coupling part, which are arranged on the two quick-coupling parts in such a way that, when the two quick-coupling parts pivot together about a first of the two locking axes, they move toward each other on a circular path around the first locking axis, thereby automatically coupling with each other. At least one of the two power coupling parts, hereinafter referred to as the movable power coupling part, is mounted so as to be pivotable about an axis parallel to the first locking axis and movable or displaceable perpendicular to it.

[0010] Furthermore, the energy circuit coupling comprises a linear guide which is designed, in cooperation with the movable bearing of the movable energy coupling part, to compensate for the relative movement of the two energy coupling parts along a circular path when the quick coupling parts are pivoted together and to guide the two energy coupling parts linearly, ie along a straight line, towards each other when coupling.

[0011] According to the invention, the quick coupling additionally comprises a centering device, by means of which the movable power coupling part can be held in a central position regardless of its spatial alignment or orientation, and movement of the movable power coupling part relative to the quick coupling part attached thereto can be prevented in the absence of an external force. According to the invention, the centering device is designed to enable movement of the movable power coupling part relative to the quick coupling part attached thereto during automatic coupling with the other power coupling part due to an external force generated by the coupling process.

[0012] In this context, an external force is defined as any force that does not result from the weight of the movable power coupling part or that is permanently applied to it due to the mounting / fastening / connection of the movable power coupling part with cables, hoses, etc. An external force within the meaning of the present invention is, in particular, a force that is generated by the coupling with the other power coupling part when the two quick-coupling parts are brought together and acts on the movable power coupling part.

[0013] The centering device according to the invention ensures that the movable power coupling part does not move from the central position intended for smooth coupling due to its own weight, the connection of hoses, or the like, regardless of the installation position or spatial orientation of the movable power coupling part. This makes it possible, for example, to mount the movable power coupling part vertically on the quick-coupling part of a wheel loader bucket without it swinging downward due to gravity, thus hindering or preventing the coupling of the power coupling parts.

[0014] At the same time, the mobility of the movable energy coupling part should, of course, be maintained within certain limits during the coupling process described in more detail in EP 1 239 087 A1 in order to continue to enable compensation of the circular movement by means of the linear guide. However, this mobility should only be ensured when a coupling process takes place with the other energy coupling part. For this reason, the present invention provides that the centering device is designed to enable movement of the movable energy coupling part - within certain limits - only when an external force acts on it in the sense defined above, i.e. in particular a force generated by the coupling process when the movable energy coupling part makes contact with the other energy coupling part.

[0015] As a result, the quick coupling according to the invention can be used in any installation position and independently of the connection to other components such as hoses, which significantly expands the range of possible applications. However, the present invention not only opens up further application possibilities with installation positions that differ from the current situation on hydraulic excavators. The quick coupling according to the invention with centering device can also be advantageously used on hydraulic excavators with installation positions that are unproblematic in terms of their own weight, namely particularly in cases where a hose layout is used that leads to tilting of the movable power coupling part due to the inherent stresses or prestresses of the hoses.

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

[0017] The quick coupling according to the invention is preferably a quick coupling according to EP 1 239 087 A1, which additionally comprises the centering device according to the invention. The disclosure of EP 1 239 087 A1 is explicitly incorporated into the present teaching. In particular, the quick coupling according to the invention can be designed according to any of the advantageous embodiments described in EP 1 239 087 A1, or according to any combination of the embodiments disclosed therein. The embodiments described in EP 1 239 087 A1 are thus also possible embodiments of the present quick coupling according to the invention.

[0018] Thus, the quick coupling according to the invention can, for example, be a quick coupling for coupling a tool to the boom of a hydraulic excavator and the like, with a boom-side quick coupling part and a tool-side quick coupling part, which can be locked together via a pair of spaced-apart locking axes, such that after locking only a first of the two locking axes, the two quick coupling parts can be pivoted together about the said first locking axis and then the second locking axis can be locked, as well as a power circuit coupling, in particular a hydraulic coupling, for automatically coupling a tool-side power connection to a boom-side power connection, wherein the power circuit coupling has a boom-side power coupling part and a tool-side power coupling part,which are arranged on the boom-side quick-coupling part or the tool-side quick-coupling part at a distance from the first locking axis in such a way that they move together on a circular path around the first locking axis when the two quick-coupling parts are pivoted together about the first locking axis and thereby automatically couple with each other, wherein at least one of the two energy coupling parts is tiltable about an axis parallel to the first locking axis and is mounted so as to be movable perpendicular to the first locking axis, and the energy circuit coupling is assigned a linear guide separate from the energy connections and consisting of a pair of guide pins and associated guide bores into which the said guide pins move when the two energy coupling parts move together,which, in cooperation with the movable bearing, compensates for the pivoting movement of the two energy coupling parts when pivoting together on the circular path around the first locking axis and forces the two energy coupling parts to move precisely linearly relative to one another along a straight line when coupling, wherein the quick coupling is characterized in that a centering device is provided, by means of which the movably mounted energy coupling part can be held in a central position regardless of its orientation and a movement of the movably mounted energy coupling part relative to the quick coupling part attached thereto can be prevented in the absence of an external force, wherein the centering device is designed toto enable movement of the movably mounted energy coupling part relative to the quick-coupling part attached to it during automatic coupling with the other energy coupling part due to an external force generated by the coupling process.

[0019] According to the invention, the centering device comprises at least one centering element, which is fixedly or immovably mounted on the quick-coupling part and, in the absence of an external force, holds the movable energy coupling part in the central position with a force-locking and / or positive locking. The fixation of the movable energy coupling part by means of the centering element can be achieved with both a positive and a non-positive locking action, for example, with a positive locking action in certain directions and a non-positive locking action in other directions.

[0020] According to the invention, the movable energy coupling part is mounted on the quick-action coupling part via a spring device, in particular an arrangement of one or more compression springs, which presses the movable energy coupling part against the centering element and thereby holds it in the central position or - in particular immediately after the removal of an external force deflecting the movable energy coupling part - returns it to the central position. The spring device generates a contact force on the centering element which holds the movable energy coupling part in the correct position, i.e. the spring device is preloaded in the central position. The spring force or contact force must be large enough that the movable energy coupling part is not moved from the central position in any of the possible installation positions by its own weight or the inherent stresses of possible connecting hoses.At the same time, it must be low enough to allow the movable energy coupling part to deflect when connecting with the other energy coupling part, when threading the linear guide components, and during linear merging. The centered movable energy coupling part must therefore exhibit a certain degree of flexibility when applying an external force that exceeds its own weight / hose tension, etc.

[0021] In one embodiment, the centering device comprises at least one retaining element arranged on the movable power coupling part, which is designed to interact with the at least one centering element in a force-locking and / or positive-locking manner. The at least one retaining element is thus movably mounted on the quick-coupling part together with the movable power coupling part and is pressed against the at least one centering element, in particular by the spring device.

[0022] In a further embodiment, the retaining element comprises a recess into which the centering element is at least partially received or retracted in the central position. The retaining element can itself be the recess or can comprise additional parts.

[0023] In a further embodiment, the recess has at least one bevel and / or rounded portion that interacts with at least one bevel and / or rounded portion of the centering element. The bevel / rounded portion of the interacting elements of the centering device ensures a certain degree of mobility of the movable power coupling part, which is required for the engagement process.

[0024] In a further embodiment, the recess is funnel-shaped at least along one direction, wherein the centering element is bevelled and / or rounded at least along that same direction and is preferably bolt-shaped. The recess can therefore be bevelled and / or rounded along at least one direction, resulting in a funnel shape in a corresponding cross-sectional view. As a result, the centering element, which is located in the central position partially within the recess, can move along the bevels when an external force is applied in order to enable movement of the movable energy coupling part during coupling. A bolt-shaped shape of the centering element, i.e. one that is rounded in the direction of the funnel-shaped design, is advantageous in this case.

[0025] The funnel-shaped configuration and the preferably bolt-shaped rounding should be formed at least in a plane perpendicular to the axis about which the movable power coupling part is pivoted during the coupling process. This axis is preferably perpendicular to the straight line along which the linear joining of the power coupling parts occurs, mediated by the linear guide. The bevels can also have an angle of 20-70°, in particular 25-45°.

[0026] In a further embodiment, it is provided that the recess has a particularly continuous recess. The continuous recess is therefore open, i.e. it extends through the component of the movable energy coupling part in which the recess is formed. The recess is preferably smaller than the centering element. This recess has the function of forming an opening within the recess so that no deposits or dirt can accumulate within the recess, which would prevent correct positioning of the centering element. The accumulations pass out of the recess through the recess or are pressed into the recess by the centering element. The recess can, for example, be a bore or a slot and is preferably arranged at the lowest point or bottom of the recess.Additionally or alternatively, the centering element can also have a recess on the side facing the recess, into which dirt accumulating in the recess can be forced to prevent it from clogging. This recess can also be continuous.

[0027] In a further embodiment, the movable power coupling part is mounted on the attached quick-coupling part via two spaced-apart support elements and is preferably arranged between the support elements, each of the support elements having a centering element. The support elements can be plate-shaped and extend substantially perpendicularly from the quick-coupling part. The movable power coupling part can be mounted on the support elements via a spring bearing. The support elements are in particular rigidly connected to the quick-coupling part and partially enclose the movable power coupling part.

[0028] In a further embodiment, the centering elements are bolt-shaped and each interact with a holding element as described above. The holding elements are preferably formed on or in a support block of the movable energy coupling part, which extends substantially between and perpendicular to the support elements. The support block can have one or more connector pieces that form the energy connection of the movable energy coupling part. In the case of recesses as holding elements, the recesses are formed on the upper side of the support block facing away from the quick-coupling part, in particular on the edges or sides adjacent to the support elements.Such a design is particularly easy to implement, since the recesses forming the holding elements only have to be made laterally on the upper side of the support block - for example by milling and / or drilling - and the bolt-shaped centering elements have to be attached - for example screwed - to the inner surfaces of the support elements at the appropriate locations or at the appropriate distance from the quick-coupling part.

[0029] In a further embodiment, the bolt-shaped centering elements are conical and attached to the support elements via their narrower ends. The bevel / rounded conical shape of the centering elements allows for the displacement of any deposits or dirt that may have accumulated in the recesses, thus enabling correct positioning of the centering elements in the recesses. Preferably, the recesses are open toward the sides of the support block, so that the conical shape of the centering elements allows dirt / deposits to be forced out of the recesses.

[0030] In a further embodiment, at least four centering elements and at least four holding elements are provided, wherein each of the support elements has at least two centering elements. Of the at least two centering elements provided on each side, one is preferably connected to the support element via a fixed bearing and the other via a loose bearing, thus forming a fixed-loose arrangement, i.e. the centering element connected via the loose bearing is not rigidly attached to the support element, but is movably mounted so that a certain relative mobility is provided between the two centering elements. This means that more than one centering element can be used per support element, which increases the stability of the centering and still ensures the necessary degree of mobility of the movable energy coupling part for the coupling process.Furthermore, it is conceivable to mount one or more of the centering elements rotatably on the support element.

[0031] In a further embodiment, the power connection of the movable power coupling part is arranged on the side of the carrier block facing away from the movable bearing on the quick-action coupling part and is designed such that, upon coupling with the other power coupling part, a coupling is automatically established with the other power connection arranged thereon to create a power circuit connection. The power connection can comprise one or more connector pieces which can be pushed together or connected with corresponding connector pieces of the other power coupling part and bring about the corresponding power connection (e.g. hydraulic fluid connection). The connector pieces extend in particular perpendicularly away from the carrier block and can be known female and male connector pieces. In this sense, the carrier block can also be referred to as a connector block.

[0032] In a further embodiment, the movable power coupling part is arranged on the tool-side quick-coupling part of a tool, in particular a wheel loader bucket, and is preferably aligned such that the coupling of the power coupling parts mediated by the linear guide takes place along a substantially horizontal line. The movable power coupling part is thus rotated approximately 90° relative to the installation position typically used on hydraulic excavators. Without the centering device according to the invention, the movable power coupling part would be tilted out of the central position required for a smooth coupling procedure due to its own weight, hose tension, and the movable bearing.

[0033] The linear guide preferably comprises at least two guide pins on one power coupling part and corresponding guide bores on the other power coupling part, into which said guide pins move when the two power coupling parts move together. In doing so, they force the spring device to deflect in order to compensate for the pivoting movement component. The guide pins are rigidly connected to the support block and protrude perpendicularly beyond it towards the opposite power coupling part. Each guide pin is preferably essentially cylindrical and has a rounded head, which prevents tilting when inserted into the guide bores. Furthermore, it can be provided that the holding elements / recesses in the support block are aligned or in a line with the guide pins / guide bores of the linear guide.

[0034] The present invention further relates to a work tool, in particular a wheel loader, with a quick-action coupling according to the invention. This obviously results in the same advantages and properties as the quick-action coupling according to the invention, which is why a repeated description is omitted here. The above statements regarding the possible configurations of the quick-action coupling according to the invention therefore apply accordingly.

[0035] Further features, details, and advantages of the invention will become apparent from the following exemplary embodiments explained with reference to the figures. They show: Figure 1: an embodiment of the movable energy coupling part of the quick coupling according to the invention in a perspective view; Figure 2: two support elements for fastening the energy coupling part according to Figure 1 on a quick coupling part in a perspective view; Figure 3: the on the support elements according to Figure 2 attached energy coupling part according to Figure 1 in a plan view; Figure 4: a frontal cross-sectional view of the device according to Figure 3 along the line AA; Figure 5: a side cross-sectional view of the device according to Figure 3 along the line BB; and Figure 6: an alternative embodiment of the movable energy coupling part of the quick coupling according to the invention in a schematic side view.

[0036] The preferred embodiment of the quick coupling according to the invention discussed below is essentially a quick coupling according to EP 1 239 087 A1, with a centering device additionally provided, which is described in detail below. Those elements and properties of the quick coupling according to the invention that are not explicitly described below preferably correspond to one of the embodiments disclosed in EP 1 239 087 A1.

[0037] The quick coupling according to the invention comprises a boom-side and a tool-side quick coupling part, which can be reversibly locked to one another via a pair of spaced-apart, parallel locking axes. The quick coupling has a power circuit coupling comprising a tool-side power coupling part fastened to the tool-side quick coupling part and a boom-side power coupling part fastened to the boom-side quick coupling part. The tool-side power coupling part is movably mounted on the quick coupling part via a spring device 16 and is referred to below as the movable power coupling part 10. The other power coupling part fastened to the boom-side quick coupling part is not movably mounted in this exemplary embodiment, although this is not mandatory. The other power coupling part could therefore also be movably mounted in one embodiment.

[0038] The power coupling parts each have a power connection 12 comprising a plurality of connector pieces 13, each arranged on a support block 18 and projecting perpendicularly therefrom. By connecting or coupling the power connections 12 or the respective connector pieces 13, a power circuit connection is closed, in particular a hydraulic connection for supplying a hydraulic tool with hydraulic oil. This can be, for example, a wheel loader bucket with hydraulic components.

[0039] The energy coupling parts further comprise a linear guide 14, which forces the energy coupling parts to move relative to one another along a line or straight line, counter to the circular pivoting movement around one of the two locking axes. In the present embodiment, the linear guide comprises two parallel guide pins 14, which are arranged on the carrier lock 18 of the movable energy coupling part 10 and protrude perpendicularly therefrom, as well as corresponding guide bores on the other energy guide part, into which the guide pins 14 retract during coupling and force the linear coupling movement before the connector pieces 13 engage with each other.

[0040] For further details, properties, and advantages of the quick-coupling parts, energy coupling parts, and linear guides, as well as the further design of the quick-coupling, reference is explicitly made to EP 1 239 087 A1. In the following, only the movable energy coupling part 10 and its mounting on the quick-coupling part, as well as the centering device according to the invention, are discussed.

[0041] In the Figure 1The movable energy coupling part 10 of the quick coupling according to the invention is shown in a perspective view, wherein the quick coupling part attached thereto has been hidden for reasons of clarity. The movable energy coupling part 10 comprises a substantially plate-shaped support block 18, which is movably mounted on the quick coupling part on a spring device 16 comprising four compression springs. Several connector pieces 13 and two guide pins 14 of the linear guide are arranged on the support block 18, which protrude parallel from the surface of the support block 18 opposite the spring device 16. Furthermore, two pressure tappets 17 are arranged on the side of the spring device 16, the function of which is described in EP 1 239 087 A1.

[0042] The movable energy coupling part 10 is mounted on two lateral support elements 30, which are rigidly connected to the quick-coupling part. The support elements 30 are shown individually in a perspective view in the Figure 2 They are plate-shaped, differ in shape, and are aligned parallel to each other. The support elements 30 are arranged at a distance from one another, so that the support block 18 is mounted between them. The support block 18 is mounted via the spring device 16 on two fastenings 32 formed or mounted on the inner sides of the support elements 30. The pressure tappets 17 are also mounted on the fastenings 32.

[0043] The support block 18 and the positions of the components arranged thereon are axially symmetrical. It has a substantially rectangular basic shape in plan view and extends substantially perpendicularly between the support elements 30. The short sides of the support block 18 rest against the support elements 30.

[0044] According to the invention, a centering element 20 is mounted on the inside of each support element 30, in the present embodiment via a screw connection. Furthermore, the support block 18 has two recesses 24 laterally in the area of ​​the edges, which form the holding elements 22, which interact with the centering elements 20 and, together with them, form the centering device according to the invention. The centering elements 20 are rigidly connected to the quick-coupling part via the support elements 30, while the holding elements 22 are movably mounted due to the spring-loaded mounting of the support block 18 and are movable relative to the centering elements 20.

[0045] The Figure 3 shows the movable energy coupling part 10 together with the support elements 30 to which it is mounted in a plan view. A frontal cross-sectional view along the line AA is shown in the Figure 4 and a side cross-sectional view along the line BB in the Figure 5shown.

[0046] The centering elements 20 are attached to the support elements 30 at such a distance from the fastenings 32 that the support block 18 is pressed against the centering elements 20 by the spring device 16. This contact pressure holds the support block 18 or the movable energy coupling part 10 in a defined position, which is referred to herein as the central position. In this central position, the guide pins 14 can be threaded correctly and without jamming into the corresponding guide bores of the other energy coupling part (not shown) during the coupling process. By pressing on, the movable energy coupling part 10 is held in the central position even if the support block 18 is not oriented substantially horizontally (as is the case, for example, in EP 1 239 087 A1), but has a different, in particular vertical, installation position.The contact force is dimensioned such that, in any installation position, the movable power coupling part 10 does not move from its central position due to its own weight and / or the rigidity / intrinsic stress of the hoses (not shown) connected to it via the hose connectors 11. This makes the quick coupling according to the invention particularly suitable for use on a wheel loader bucket.

[0047] In order to ensure a certain degree of mobility of the support block 18 despite the contact pressure generated by the spring device 16, which is required to compensate for the circular movement during the coupling process by means of the linear guide 14, the recesses 24 are funnel-shaped and the centering elements 20 are designed as round bolts. The recesses 24 have a rectangular or slot-shaped shape in plan view and are conically chamfered towards the center along the short sides of the support block 18. The chamfers have an angle of approximately 30°, although other angles are also possible. In the center of each recess 24, the chamfers merge into a rectangular recess 26 which extends through the entire support block 18 and opens into the underside of the support block 18. The recesses 24 are also open laterally on the short sides of the support block 18, i.e. towards the support elements 30.

[0048] The centering elements 20 are designed as conically shaped bolts with a circular cross-section, which are fastened to the support elements 30 via the short side. In the central position, the centering elements 20 are partially received in the recesses 24 (see. Figures 4 and 5 ). Due to the bevels, a movement of the support block 18, in particular a pivoting or tilting about a pivot axis parallel to the first locking axis and / or a displacement, relative to the centering elements 20 is possible due to external forces occurring during the coupling process. Thus, the support block 18 or the movable power coupling part 10 is held in the central position by the centering elements 20 in a form-fitting manner in the direction of the coupling line defined by the linear guide 14 and in a force-fitting manner in a direction perpendicular thereto.

[0049] The contact force exerted by the spring device 16 is adjusted to ensure the mobility of the support block 18 when an external force generated as a result of the coupling process occurs. If the support block 18 is deflected from the central position by such an external force and this external force disappears, the movable power coupling part 10 is moved or pushed back into the central position by the spring device 16.

[0050] As in the Figure 5As can be seen, the compression springs of the spring device 16 are not evenly compressed in the central position and are not aligned parallel to one another. Furthermore, the centering elements 20 are not arranged centrally above the support block 18, but slightly offset laterally from it, specifically on the straight line connecting the guide pins 14. However, other arrangements of the centering elements 20 are also possible, for example, an arrangement in which they are not aligned with the guide pins 14.

[0051] The recesses 26 in the cutouts 24 prevent dirt or deposits from accumulating in the cutouts 24 and blocking them, which would prevent correct positioning of the movable power coupling part 10. The deposits are pressed into the cutouts 26 by the centering elements 20 and thus forced out of the cutouts 24. Furthermore, the conical shape of the centering elements 20 ensures that dirt or deposits are pushed outward and laterally out of the cutouts 24. This keeps the cutouts 24 free of contamination, ensuring correct positioning in the central position.

[0052] The Figure 6shows a further embodiment of the movable energy coupling part 10 of the quick coupling according to the invention in a side view looking at the short side of the carrier block 18. Here, instead of one centering element 20, two centering elements 20 are provided per carrier element 30. Accordingly, the carrier block 18 has two funnel-shaped recesses 24 on each short side. The two centering elements 20 of each carrier element 30 form a fixed-loose arrangement, with one of the centering elements 20 being connected to the quick coupling part or carrier element 30 via a fixed bearing and the other via a loose bearing. This makes it possible to provide more than one centering element 20 per carrier element 30, which increases the inherent stability of the movable energy coupling part 10 in the central position but still allows a certain mobility of the carrier block 18 for the purpose of coupling with the other energy coupling part.Here, the use of more than two centering elements 20 per side / support element 30 is also conceivable. A rotatable mounting of one or more centering elements 20 on the support elements 30 could also be provided. List of reference symbols:

[0053] 10Movable energy coupling part 11Hose connection 12Energy connection 13Connector piece 14Linear guide / guide pin 16Spring device 17Pressure tappet 18Support block 20Centering element 22Holding element 24Recess 26Recess 30Support piece 32Fastening

Claims

1. Quick coupling (10) for coupling a tool to the boom of a working machine, in particular of a wheel loader, comprising: - a quick coupling part at the boom side and a quick coupling part at the tool side; and - an energy circuit coupling for the automatic coupling of an energy connector at the tool side to an energy connector at the boom side, - wherein the quick coupling parts are reversibly latchable to one another via a pair of spaced latching axles; - wherein the energy circuit coupling comprises an energy coupling part at the boom side and at the tool side that are arranged at the quick coupling parts such that they move toward one another and thereby automatically couple with one another by the pivoting together of the two quick coupling parts about a first latching axle on a circular path about the first latching axle; - wherein at least one movable energy coupling part (12) is pivotable about an axle in parallel with the first latching axle and is movably supported perpendicular thereto; and - wherein the energy circuit coupling comprises a linear guide (14) that is configured to compensate the relative movement of the two energy coupling parts occurring along a circular path on the pivoting together of the quick coupling parts in cooperation with the movable support of the movable energy coupling parts (12) and to guide the two energy coupling parts linearly with respect to one another during coupling, characterized by - a centering device by means of which the movable energy coupling part (12) is holdable in a central position independently of its alignment and a movement of the movable energy coupling part (12) relative to the quick coupling part fastened thereto is preventable in the absence of an external force, - wherein the centering device is configured to enable a movement of the movable energy coupling part (12) relative to the quick coupling part fastened thereto on the automatic coupling with the other energy coupling part due to an external force generated by the coupling procedure, - wherein the centering device comprises at least one centering element (20) that is fixedly supported at the quick coupling part and holds the movable energy coupling part (12) in the central position in a force-fitting and / or form-fitting manner in the absence of an external force, and - wherein the movable energy coupling unit (12) is supported at the quick coupling part via a spring device (16) that presses the movable energy coupling part (12) against the centering element and thereby holds it in the central position or moves it into it.

2. Quick coupling (1) in accordance with claim 1, characterized in that the spring device (16) comprises an arrangement of a plurality of compression springs.

3. Quick coupling (1) in accordance with claim 1 or 2, characterized in that the centering device comprises at least one holding element (22) that is arranged at the movable energy coupling part (12) and that is configured to cooperate with the at least one centering element (20) in a form-fitting and / or force-fitting manner.

4. Quick coupling (10) in accordance with claim 3, characterized in that the holding element (22) comprises a cutout (24) in which the centering element (20) is at least partially received in the central position.

5. Quick coupling (10) in accordance with claim 4, characterized in that the cutout (24) comprises at least one chamfer and / or rounded portion that cooperates with at least one chamfer and / or rounded portion of the centering element (20).

6. Quick coupling (10) in accordance with claim 5, characterized in that the cutout (24) is configured in funnel shape at least along one direction, wherein the centering element (20) is chamfered and / or rounded at least along just that direction and preferably is configured in the type of a pin.

7. Quick coupling (10) in accordance with any one of the claims 4 to 6, characterized in that the cutout (24) comprises an in particular continuous recess (26).

8. Quick coupling (10) in accordance with any one of the preceding claims, characterized in that the movable energy coupling part (12) is supported at the quick coupling part fastened thereto via two spaced apart carrier elements (30) and is preferably arranged between the carrier elements (30), with each of the carrier elements (30) having a centering element (20).

9. Quick coupling (10) in accordance with claim 8, characterized in that the centering elements (20) are configured in the type of a pin and each cooperate with a holding element (22) in accordance with any one of the claims 3 to 7, wherein the holding elements (22) preferably are formed at or in a carrier block (18) of the movable coupling part (12) that substantially extends between the carrier elements (30) and perpendicular thereto.

10. Quick coupling (10) in accordance with claim 9, characterized in that the pin-shaped centering elements (20) are conical and are fastened to the carrier elements (30) via the narrower ends.

11. Quick coupling (10) in accordance with claim 9 or 10, characterized in that at least four centering elements (20) and at least four holding elements (22) are provided, wherein each of the carrier elements (30) comprises at least two respective centering elements (20) of which one is preferably connected to the carrier element (30) via a fixed support and the other via a loose support such that two respective centering elements (20) form a fixed-loose arrangement.

12. Quick coupling (10) in accordance with any one of the claims 9 to 11, characterized in that the energy connector (11) of the movable energy coupling part (12) is arranged on the side of the carrier block (18) facing away from the movable support at the quick coupling part and is configured such that, on the coupling with the other energy coupling part, a coupling with the other energy connector arranged thereat is automatically established to establish an energy circuit connection.

13. Quick coupling (10) in accordance with any one of the preceding claims, characterized in that the movable energy coupling part (12) is arranged at the quick coupling part of a tool, in particular of a wheel loader bucket.

14. Quick coupling (10) in accordance with claim 13, characterized in that the movable energy coupling part (12) is aligned such that the coupling of the energy coupling part communicated by the linear guide (14) takes place along a substantially horizontal line.

15. Working machine, in particular a wheel loader, comprising a quick coupling (10) in accordance with any one of the preceding claims.