Quick coupling with centering device

Abstract

To make it possible to use a quick coupling regardless of an assembly position and status of a power coupling portion.SOLUTION: A quick coupling for coupling a tool to a boom of a working machines, especially a wheel loader in this invention comprises: a boom side quick coupling portion and a tool side quick coupling portion that are hooked to one another via two spaced apart latching shafts; and a power circuit coupling for an automatic coupling of a tool side power coupling portion and a boom side power coupling portion by moving on a circulating track toward one another by pivoting together about a first latching shaft. At least one of the power coupling portions is movably supported. The power circuit coupling comprises a linear guide that compensates for a circular relative movement of the power coupling portions on pivoting and guides them linearly toward one another. In this invention, the quick coupling includes a centering device which holds the movable power coupling portion at a center position regardless of its disposition, prevents movement when there is no external force, and enables movement of the movable power coupling portion by an external force generated in a connection process in automatically connecting.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a quick joint for connecting a tool to a boom of a work machine according to the preamble of claim 1, and to a work machine having such a quick joint. [Background technology]

[0002] Swivel-type quick couplings are widely used on certain work machines, such as hydraulic excavators, to allow easy and fast exchange of various tools, such as hydraulic grabs, excavation buckets, and reachers. First, only one of the two latch shafts of the quick coupling needs to be aligned and engaged for connection. This is preferably achieved by a cross pin that hooks into a hook-shaped eyelet on the opposite quick coupling section. The boom-side quick coupling section can then be swiveled around the already engaged latch shaft relative to the tool to a latched position that can be locked at a second latch angle. The latch shafts are generally formed by a pair of latch pins that move separately into corresponding latch holes on the opposite quick coupling section.

[0003] To make the hydraulic connection, such a quick coupling can have a power circuit coupling or a hydraulic coupling, and each quick coupling part has a corresponding power coupling part that pivots with the quick coupling part and automatically merges together. To compensate for the circular movement of the power coupling parts relative to each other as they pivot about the first latch axis, it is known to movably support one of the two power coupling parts, typically the tool side power coupling part, for example by means of a compression spring. However, this method often leads to improper coupling and oil leakage.

[0004] In order to overcome this drawback of known power circuit joints and to prevent the connecting connectors of the power coupling parts from tilting, Patent Document 1 proposes providing a linear guide for the power coupling parts in order to move the power coupling parts linearly relative to each other along a straight line against a pivoting movement. For this purpose, the linear guide has guide elements which cooperate with the boom side power coupling part and the tool side power coupling part when they are connected, and the guide elements can be configured, for example, as guide pins and guide holes which engage with each other before the connecting connectors come together to perform a precise linear relative movement.

[0005] However, this concept of connection only works without failure if the movably supported power coupling part does not deviate from a well-defined center or central position where the guide elements of the linear guide are aligned and can guide each other without tilting. Therefore, it is difficult or prohibited to use quick couplings in applications where the freely supported power coupling part deviates from the central position due to its own weight. This problem becomes even more serious when a tube is connected to the power coupling part and the tension in the tube itself causes the power coupling part to deviate significantly from the central position. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent Application Publication No. 1239087 Summary of the Invention [Problem to be solved by the invention]

[0007] An example of such a problematic mounting position is the use of such a quick coupling in a wheel loader. Unlike hydraulic excavators, the assembly orientation of the tool-side power coupling part is vertical, i.e. the linear coupling of the power coupling part connected by the linear guide is substantially along a horizontal line. The movable power coupling part rotates under its own weight and moves out of the center position under the influence of gravity, so that the guide elements, i.e. the guide pins and the guide bores, are not aligned with each other. The misalignment of the movable power coupling part makes it more difficult or even impossible to couple or connect the guide elements. Therefore, a forced coupling to eliminate the misalignment can cause significant wear and damage.

[0008] SUMMARY OF THEINVENTION The object of the present invention is therefore to overcome this drawback and to make it possible to use such a quick coupling regardless of the installation position and circumstances of the power coupling part. [Means for solving the problem]

[0009] According to the present invention, this object is achieved by a quick coupling having the features of claim 1. The quick coupling according to the invention is provided for connecting a tool to the boom of a work machine, in particular a wheel loader, and comprises a boom side quick coupling part and a tool side quick coupling part and a power circuit coupling for automatically connecting the tool side power connection part to the boom side power connection part. The quick coupling parts can be reversibly latched to each other by a pair of spaced apart latch shafts.

[0010] The power circuit coupling comprises a boom side power coupling section and a tool side power coupling section, which are arranged in the quick coupling section such that the two quick coupling sections are automatically coupled to each other by pivoting together about the first latch shaft and thereby moving towards each other on a circular path about the first latch shaft. At least one of the two power coupling sections, hereinafter also referred to as the movable power coupling section, is supported so as to be movable around an axis parallel to the first latch shaft or displaceable perpendicular to the first latch shaft.

[0011] Furthermore, the power circuit joint is provided with a linear guide, which cooperates with the movable support of the movable power joint part to compensate for the relative movement of the two power joint parts that occurs along the circular orbit in which the quick joint parts rotate together, and is configured to guide the two power joint parts linearly, i.e., along a straight line, relative to each other when connected.

[0012] According to the invention, the quick coupling further comprises a centering device capable of holding the movable power coupling part in a central position regardless of its arrangement or orientation and capable of preventing the movable power coupling part from moving in the absence of an external force relative to the quick coupling part fixed to the movable power coupling part. According to the invention, the centering device is configured to allow the movable power coupling part to move in the absence of an external force generated by the coupling process relative to the quick coupling part fixed to the movable power coupling part during automatic coupling with another power coupling part.

[0013] In this specification, an external force is defined as a force that is not caused by the weight of the movable power coupling part or that does not permanently act on the movable power coupling part due to the holding / fixing / connection of the cables, tubes, etc. In particular, an external force in the sense of the present invention is a force that acts on the movable power coupling part when two quick coupling parts are brought together, which is generated by the connection with other power coupling parts.

[0014] The centering device according to the present invention prevents the movable power coupling from moving from its center position for frictionless connection due to its own weight, tube connection, etc., regardless of the installation position or spatial orientation of the movable power coupling. Therefore, for example, the movable power coupling can be attached at a right angle to the quick coupling of a wheel loader blade, and the movable power coupling will not rotate downward due to gravity, making it difficult or impeded to connect the power coupling.

[0015] At the same time, the coupling process, the details of which are given in EP 1 239 087 A1, naturally requires that the mobility of the movable power coupling part must be maintained within a predefined range in order to allow the linear guide to continue to correct the circular movement. However, this mobility should only occur when the coupling process with the other power coupling part is carried out. For this reason, in the present invention, the centering device is designed to only allow the movement of the movable power coupling part within a predefined range when it is subjected to external forces in the sense of the above definition, i.e. forces which arise in particular from the coupling process when the movable power coupling part comes into contact with the other power coupling part.

[0016] The quick coupling according to the invention can therefore be used in any installation position, independent of the connection to other components such as tubes, thus significantly expanding the possibilities of application. However, the invention does not only open up the possibility of application in installation positions different from the previous situation of hydraulic excavators. The quick coupling according to the invention with a centering device can also be effectively used in hydraulic excavators in installation positions where there are no problems with regard to the self-weight, i.e. especially when a tube arrangement is used in which the stress or preload of the tubes results in the movable power coupling section tilting.

[0017] Advantageous configurations of the invention are explained below based on the dependent claims.

[0018] The quick joint according to the invention is preferably a quick joint according to EP 1 239 087 A further comprising a centering device according to the invention. The disclosure content of EP 1 239 087 A is expressly incorporated herein. In particular, the quick joint according to the invention can be constructed according to any of the advantageous embodiments described in EP 1 239 087 A or according to any combination of the embodiments disclosed therein. The embodiments described in EP 1 239 087 A are thus likewise possible embodiments of the quick joint according to the invention.

[0019] The quick coupling according to the present invention is for connecting a tool to, for example, the boom of a hydraulic excavator, and has a boom-side quick coupling part and a tool-side quick coupling part. These quick coupling parts can be engaged with each other via a pair of spaced apart latch shafts so that after only a first latch shaft of the two latch shafts is engaged, the two quick coupling parts can be rotated together around the first latch shaft before the second latch shaft is engaged. This quick coupling has, in particular, a power circuit coupling which is a hydraulic coupling for automatically connecting the tool-side power coupling to the boom-side power coupling. The power circuit coupling has a boom side power coupling section and a tool side power coupling section arranged away from the latch axis at the boom side quick coupling section or the tool side quick coupling section, the two quick coupling sections move together by rotating together around the first latch axis on a track around the first latch axis, thereby automatically connecting to each other, at least one of the two power coupling sections is supported so that the inclination angle can be changed around an axis parallel to the first latch axis and is movable perpendicular to the first latch axis, and a linear guide separate from the power coupling, which has a pair of guide pins and corresponding guide holes through which the guide pins move as the two power coupling sections move together, cooperates with the power circuit coupling and, by interaction with the movable support, corrects the rotating motion when the two power coupling sections rotate together on a track centered on the first latch axis, and forces the two power coupling sections to make accurate linear movement with each other along a straight line when connected. The quick coupling is characterized in that a centering device is provided, by which the movably supported power coupling part can be held in a central position regardless of its arrangement, and which can prevent movement of the power coupling part movably supported relative to the quick coupling part in the absence of an external force, and the centering device is configured so that when automatically coupling with another power coupling part, it is movable relative to the quick coupling part to which it is fixed due to external forces generated by the coupling process.

[0020] In one embodiment, the centering device has at least one centering element that is fixedly or immovably supported on the quick coupling part and holds the movable power coupling part in a center position in a force-transmitting and / or form-transmitting manner in the absence of an external force. The fixing of the movable power coupling part by the centering element can be both form-conforming and force-transmitting, for example form-conforming in one direction and force-transmitting in another direction.

[0021] In another embodiment, the movable power coupling part is supported on the quick coupling part via a spring device, in particular an arrangement of one or more compression springs, which presses the movable power coupling part against the centering element to hold it in a central position or to move it to the central position, in particular immediately after the removal of an external force that deforms the movable power coupling part. The spring device generates a pressing force on the centering element that holds the movable power coupling part in the correct position, i.e. the spring device is preloaded in the central position. The spring force or pressing force must be large enough that the movable power coupling part does not move from the central position in any of the possible assembly positions due to its own weight or the tension of the possible connecting tube. At the same time, the spring force or pressing force must be small enough to allow a deviation of the movable power coupling part when it is connected to the other power coupling part, when the linear guide parts advance and when they are linearly guided together. Thus, the movable power coupling part in the center must have a certain degree of mobility when an external force exceeding its own weight / tube tension etc. is applied to it.

[0022] In yet another embodiment, the centering device comprises at least one retaining element arranged on the movable power part and configured to cooperate with the at least one centering element in a force-transmitting manner and / or form-matching manner, the at least one retaining element thus being movably supported on the quick coupling part together with the movable power coupling part and being pressed against the at least one centering element, in particular by a spring device.

[0023] In yet another embodiment, the retaining element has a notch into which the centering element is at least partially received or moved in a central position. The retaining element may itself be a notch or may further comprise additional parts.

[0024] In yet another embodiment, the cutout has at least one chamfer and / or curved portion which cooperates with at least one chamfer and / or curved portion of the centering element, the chamfer / curved portion of the cooperating element of the centering device ensuring a certain mobility of the movable power coupling part which is necessary for the coupling process.

[0025] In a further embodiment, the cutout is funnel-shaped in at least one direction and the centering element has a chamfer and / or a curved portion in at least that direction, preferably configured as a pin. The cutout can thus have a chamfer and / or a curved portion in at least one direction, such that it is funnel-shaped in the corresponding cross-sectional view. The centering element, which is partially located in the cutout in a central position, can be moved by application of an external force along the chamfer, allowing a movement of the movable power coupling part when coupled. In this respect, a pin-like shape of the centering element, i.e. a rounded shape in the direction of the funnel-shaped embodiment, is preferred.

[0026] The funnel-shaped configuration and preferably the pin-shaped curved portion should at least be formed in a plane perpendicular to the axis about which the movable power coupling part pivots during the pivoting process, which is preferably perpendicular to the line along which the linear merging of the power coupling parts mediated by the linear guide takes place. Furthermore, the chamfer can have an angle of 20-70°, in particular 25-45°.

[0027] In yet another embodiment, the cutout has in particular a continuous recess. The continuous recess is therefore open, i.e. it penetrates the component of the movable power coupling part in which the cutout is formed. The recess is preferably smaller than the centering element. This recess has the function of forming an opening in the recess, so that deposits and dirt that would prevent the correct positioning of the centering element do not accumulate in the cutout. The accumulations either move through the recess and out of the cutout or are pushed into the recess by the centering element. The recess can be, for example, a hole or a groove and is preferably arranged at the lowest point or bottom of the cutout. Additionally or alternatively, the centering element can have a recess on the side facing the cutout, in order to push dirt that accumulates in the cutout and prevent it from becoming clogged. Likewise, the cutout can be continuous.

[0028] In yet another embodiment, the movable power coupling part is supported on the attached quick coupling part via two spaced apart carrier elements, preferably arranged between the carrier elements, each of the carrier elements having a centering element. The carrier elements are formed in a plate shape and extend substantially perpendicularly from the quick coupling part. The movable power coupling part may be supported on the carrier element by a spring support. In particular, the carrier element is rigidly connected to the quick coupling part and partially surrounds the movable power coupling part.

[0029] In yet another embodiment, the centering elements are formed in the shape of a pin and each of them cooperates with the aforementioned holding element. The holding elements are preferably formed in the carrier block of the movable coupling part, which extends substantially at a right angle between the carrier elements, or inside the carrier block. The carrier block may have one or more connector pieces forming the power connector of the movable power coupling part. In the case of a cut-out as a holding element, the cut-out is formed on the upper side of the carrier block remote from the quick coupling part, in particular on an edge or side adjacent to the carrier element. Such an embodiment is particularly easy, since the cut-out forming the holding element only needs to be formed laterally on the upper side of the carrier block, for example by milling or drilling, and the pin-shaped centering element only needs to be attached, for example by screwing, to the inner surface of the carrier element at a corresponding position or a corresponding distance from the quick coupling part.

[0030] In yet another embodiment, the pin-like centering element is conical and is attached to the carrier element via its narrow end. The chamfer / curved portion of the conical shape of the centering element allows for correct positioning of the centering element in the cutout, as any dirt or debris that may have accumulated therein can be pushed out of the cutout. Preferably, the cutout opens towards the side of the carrier block, so that the conical shape of the centering element allows for the dirt / debris to be pushed out of the cutout.

[0031] In yet another embodiment, at least four centering elements and at least four holding elements are provided, each of the carrier elements having at least two centering elements. Of the at least two centering elements, preferably one is connected to the carrier element by a fixed support and the other by a loose support, forming a fixed / loose support arrangement, i.e. the centering element connected by a loose support is not rigidly connected to the carrier element but is movably mounted so as to allow a certain relative movement between the two centering elements. This allows the use of multiple centering elements per carrier element, thus increasing the centering stability and nevertheless ensuring the required degree of mobility of the movable power coupling for the coupling process. Furthermore, it is also conceivable to rotatably support one or more centering elements on the carrier element.

[0032] In yet another embodiment, the power coupling of the movable power coupling section is arranged on a side of the carrier block away from the movable bearing of the quick coupling section and is configured to automatically couple with the other power couplings arranged thereon to establish a power circuit connection when coupled to the other power coupling section. The power connector can have one or more connector pieces that can press or connect to corresponding connector pieces of the other power coupling section to achieve a corresponding power connection (e.g., hydraulic fluid connection). In particular, the connector pieces extend 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.

[0033] In yet another embodiment, the movable power coupling is arranged in a quick coupling of a tool, in particular a tool-side blade of a wheel loader, preferably aligned so that the coupling of the power coupling, which is connected by a linear guide, is substantially along a horizontal line. The movable power coupling is therefore rotated by about 90° with respect to the general mounting position of the excavator. Without the centering device according to the invention, the movable power coupling would be tilted from the center position required for a frictionless coupling process by its own weight, by the tension of the tubes and by the movable support.

[0034] Preferably, the linear guide has at least two guide pins of one power coupling section and corresponding guide bores of the other power coupling section into which the guide pins move when the two power coupling sections move together. In the process, the spring device is forced to deflect in order to compensate for the pivoting movement component. The guide pins are rigidly connected to the carrier block and project at a right angle towards the oppositely arranged power coupling section. Each guide pin is preferably substantially cylindrical and has a rounded head to prevent tilting when introduced into the guide pin. Furthermore, the retaining elements / cutouts of the carrier block are arranged in alignment or in a line with the guide pins / guide bores of the linear guide.

[0035] Furthermore, the invention relates to a working machine, in particular a wheel loader, having a quick joint according to the invention. In this respect, the same advantages and properties as the quick joint according to the invention clearly arise, so that they will not be repeated at this point. The above explanations regarding the possible embodiments of the quick joint according to the invention apply accordingly.

[0036] Further features, details and advantages of the present invention will become apparent from the following description of the embodiments with reference to the drawings. [Brief description of the drawings]

[0037] [Figure 1] FIG. 1 is a perspective view of an embodiment of a movable power coupling portion of a quick coupling according to the present invention. [Diagram 2] FIG. 2 is a perspective view of two carrier elements for fastening the power coupling part of the quick coupling shown in FIG. 1 to the quick coupling part. [Diagram 3] 3 is a plan view of the power coupling part shown in FIG. 1 fixed to the carrier element according to FIG. 2; [Figure 4] FIG. 4 is a front cross-sectional view of the device shown in FIG. 3 taken along line AA. [Diagram 5] FIG. 5 is a side cross-sectional view of the device shown in FIG. 3 taken along line BB. [Figure 6] FIG. 6 is a schematic side view of a movable power coupling portion of a quick coupling according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] A preferred embodiment of the quick joint according to the invention described below is essentially a quick joint according to EP 1 239 087 with the addition of a centering device, which is described in detail below. Elements and features of the quick joint according to the invention that are not explicitly described below preferably correspond to one of the embodiments disclosed in EP 1 239 087.

[0039] The quick coupling according to the present invention has boom side and tool side quick coupling parts, which can be reversibly latched to each other by a pair of latch shafts arranged in parallel at a distance. The quick coupling has a power circuit coupling with a tool side power coupling part fixed to the tool side quick coupling part and a boom side power coupling part fixed to the boom side quick coupling part. The tool side power coupling part is movably supported on the quick coupling part via a spring device 16, and is hereinafter referred to as a movable power coupling part 10. Note that in this embodiment, the other power coupling part fixed to the boom side quick coupling part is not movably supported, but this is not essential. Therefore, in some embodiments, the other power coupling part can be movably supported in the same way.

[0040] The power coupling section includes a power coupling 12 with a number of connector pieces 13 each disposed on a carrier block 18 and projecting at right angles therefrom. Connecting or coupling the power coupling 12 or each connector piece 13 completes a power circuit connection, particularly a hydraulic connection for supplying hydraulic fluid to a hydraulic tool, such as the blade of a wheel loader having hydraulic components in this regard.

[0041] The power coupling parts further comprise a linear guide 14, which forces the power coupling parts to move towards each other along a line segment or straight line for orbital movement around one of the two latch axes. In this embodiment, the linear guide comprises two parallel guide pins 14 arranged on and projecting at right angles from the carrier block 18 of the movable power coupling part 10 and corresponding guide bores in the other power guide part, which move into the coupling to force a linear coupling movement before the connector pieces 13 engage with each other.

[0042] Further details, features and advantages of the quick coupling part, the power coupling part and the linear guide as well as further constructions of the quick coupling are given in EP 1 239 087. In the following only the movable power coupling part 10 according to the invention and its support and centering device in the quick coupling part are described.

[0043] In Fig. 1 a movable power coupling part 10 of a quick coupling according to the invention is shown in a perspective view, with the quick coupling part fixed thereto removed for the sake of clarity. The movable power coupling part 10 has a substantially plate-shaped carrier block 18 which is movably supported in the quick coupling part by a spring arrangement 16 with four compression springs. In the carrier block 18 a number of connector pieces 13 of a linear guide and two guide pins 14 are arranged, which project parallel from the surface of the carrier block 18 opposite the spring arrangement 16. Furthermore, on the side of the spring arrangement 16 two pressure rams 17, the function of which is described in EP 1 239 087 A1, are arranged.

[0044] The movable power coupling part 10 is supported on two lateral carrier elements 30 which are rigidly connected to the quick coupling part. The carrier elements 30 are shown separately in the perspective view of FIG. 2. They are formed as plates of different shapes and aligned parallel to each other. The carrier elements 30 are spaced apart from each other so that the carrier block 18 is supported between them, which is attached by the spring device 16 with two fasteners 32 formed or attached to the inner surface of the carrier elements 30. Also attached to the fasteners 32 is the pressure ram 17.

[0045] The position of the carrier block 18 and the components arranged thereon is axially symmetrical. The carrier block has a substantially rectangular basic shape in plan view and extends substantially at right angles between the carrier elements 30. The short sides of the carrier block 18 abut on the carrier elements 30.

[0046] According to the invention, a centering element 20 is attached to the inner surface of each carrier element 30, in this embodiment by means of a screw connection. Furthermore, the carrier block 18 has two cutouts 24 in the region of its lateral edges, said cutouts 24 forming holding elements 22 which cooperate with the centering elements 20 and together with the centering elements form a centering device according to the invention. The centering elements 20 are rigidly connected to the quick coupling via the carrier elements 30, while the holding elements 22 are movably supported and can be moved relative to the centering elements 20 by means of the spring support of the carrier block 18.

[0047] Figure 3 shows a plan view of the movable power coupling part 10 together with the carrier element 30 to which it is mounted. A front cross-sectional view along line AA is shown in Figure 4, and a side cross-sectional view along line BB is shown in Figure 5.

[0048] The centering element 20 is fixed to the carrier element 30 at a distance from the fastener 32 such that the carrier block 18 is pressed against the centering element 20 by the spring device 16. The carrier block 18 or the movable power coupling part 10 is held in a defined position, referred to herein as the central position, by this pressing force. In this central position, the guide pin 14 can be passed without the correct tilt into the corresponding guide bore of the other power coupling part (not shown) during the coupling process. The movable power coupling part 10 is held in the central position by pressing, even if the carrier block 18 is not substantially horizontal (as for example in EP 1 239 087 A1) but rather has a different, in particular vertical, mounting position. Here, the pressing force is determined in such a way that the movable power coupling part 10, in any mounting position, cannot move from the central position due to the weight and / or the stiffness / tension of the tube (not shown) connected via the tube connector 11. This makes the quick coupling according to the invention particularly suitable for use in the blade of a wheel loader.

[0049] In order to guarantee a certain mobility of the carrier block 18, necessary to compensate for the circular movement during the coupling process by the linear guide 14, despite the pressing force generated by the spring device 16, the notches 24 are funnel-shaped and the centering elements 20 are circular pins. The notches 24 have a rectangular or slit shape in plan view and are cone-shaped chamfered towards the centre along the short sides of the carrier block 18. The angle of the chamfer is approximately 30°, but other angles are also possible. In the centre of each notch 24, the chamfer merges with a rectangular recess 25 which passes through the entire carrier block 18 and opens onto the underside of the carrier block 18. Furthermore, the chamfer 24 opens laterally towards the short sides of the carrier block 18, i.e. towards the carrier elements 30.

[0050] The centering element 20 is formed as a conical pin with a circular cross section and is attached on its short side to the carrier element 30. In the central position, the centering element 20 is partially received in the recess 24 (see figures 4 and 5). The chamfer allows movements of the carrier block 18 due to external forces occurring during the coupling process, in particular a pivoting or tilting movement around a rotation axis parallel to the first latch axis and / or a displacement relative to the centering element 20. The carrier block 18 or the movable power coupling part 10 is thus held in a central position by the centering element 20 in a form-matching manner in the direction of the coupling line defined by the linear guide 14 and in a force-transmitting manner perpendicular thereto.

[0051] The pressing force of the spring device 16 is set to ensure the mobility of the carrier block 18 upon the occurrence of an external force resulting from the coupling operation. If the carrier block 18 is displaced from the center position by such an external force and this external force is removed, the movable power coupling part 10 is returned or pushed back to the center position again by the spring device 16.

[0052] 5, the compression springs of the spring arrangement 16 are not uniformly compressed at a central location and are not aligned parallel to one another. Additionally, the centering elements 20 are not centered above the carrier block 18, but are slightly laterally offset from the center in a line connecting the guide pins 14. However, other arrangements of the centering elements 20 are possible, such as an arrangement that is not aligned with the guide pins 14.

[0053] The recess 26 in the cutout 24 prevents dirt and debris from accumulating in the recess 24 and blocking it, which would prevent correct positioning of the movable power coupling part 10. The debris is forced into the cutout 26 by the centering element 20 and is forced out of the cutout 24. Furthermore, the conical shape of the centering element 20 forces the dirt and debris to be pushed laterally out of the cutout 24. Thus, the cutout 24 always remains clean, and correct positioning in the center is guaranteed.

[0054] FIG. 6 shows a side view of another embodiment of the movable power coupling part 10 of the quick coupling according to the invention, seen towards the short side of the carrier block 18. In this figure, instead of one centering element 20, two are provided per carrier element 30. The carrier block 18 thus has two funnel-shaped cutouts 24 on each short side. The two centering elements 20 of each carrier element 30 form a fixed-loose arrangement, one of the centering elements 20 being connected to the quick coupling part or carrier element 30 by a fixed support and the other by a loose support. It is therefore possible to provide several centering elements 20 per carrier element 30, which allows for an increased inherent stability in the central position of the movable power coupling part 10, while at the same time allowing a certain mobility of the carrier block 18 for connection with other power coupling parts. Here, it is also conceivable to use more than two centering elements 20 per side / carrier element 30. It is also possible for one or more centering elements 20 to be rotatably supported on the carrier element 30. [Explanation of symbols]

[0055] 10 Movable power coupling 11 Tube Connector 12 Power coupling 13 Connector piece 14 Linear guide / guide pin 16 Spring device 17 Pressure Ram 18 Carrier Block 20 Centering Elements 22 Retention elements 24 Cutout 26 Recess 30 Carrier Piece 32 Fasteners

Claims

1. A quick coupling (10) for connecting a tool to a boom of a work machine, comprising: a boom side quick coupling portion and a tool side quick coupling portion; a power circuit coupling for automatically connecting the tool side power connection to the boom side power connection, The quick coupling parts can be reversibly latched to each other by a pair of latch shafts arranged at a distance from each other, the power circuit coupling comprises a boom side power coupling section and a tool side power coupling section, the power coupling sections being arranged on the quick coupling section such that the two quick coupling sections are automatically coupled to each other by pivoting together about the first latch axis and moving toward each other on an orbit about the first latch axis; At least one power coupling portion (12) is supported so as to be pivotable about an axis parallel to the first latch shaft and displaceable perpendicular to the first latch shaft; The power circuit joint includes a linear guide (14), and the linear guide (14) is configured to cooperate with a movable support of the movable power joint part (12) to compensate for the relative movement of the two power joint parts that occurs along a circular track along which the quick joint parts rotate together, and to linearly guide the two power joint parts relative to each other when connected; The quick joint comprises: The movable power coupling section (12) is provided with a centering device capable of holding the movable power coupling section (12) in a central position regardless of its arrangement and capable of preventing the movable power coupling section (12) from moving relative to a quick coupling section fixed to the movable power coupling section (12) in the absence of an external force; the centering device is configured to allow the movable power coupling section (12) to move relative to the quick coupling section fixed to the movable power coupling section by an external force generated by the coupling process during automatic coupling with another power coupling section; The centering device has at least one centering element (20) fixedly supported on the quick coupling part and holding the movable power coupling part (12) in a center position in a force-transmitting and / or form-matching manner in the absence of an external force; The centering device has at least one holding element (22) arranged on the movable power coupling part (12) and adapted to cooperate in a force-transmitting manner and / or a form-matching manner with the at least one centering element (20), A quick joint (10) characterized in that the retaining element (22) has a notch (24) in which the centering element (20) is at least partially received in a central position.

2. The quick joint (10) according to claim 1, A quick coupling (10) characterized in that a movable power coupling part (12) is supported on a quick coupling part via a spring device (16) that presses the movable power coupling part (12) against a centering element to hold the movable power coupling part (12) in a center position or to move the movable power coupling part (12) to the center position.

3. The quick joint (10) according to claim 1, A quick joint (10), characterized in that the notch (24) has at least one chamfer and / or curved portion which cooperates with at least one chamfer and / or curved portion of the centering element (20).

4. In the quick joint (10) according to claim 3, The quick joint (10) is characterized in that the notch (24) is formed in a funnel shape in at least one direction, and the centering element (20) has a chamfered portion and / or a curved portion in at least that direction and is configured in a pin shape.

5. A quick joint (10) according to any one of claims 1 to 4, A quick coupling (10) characterized in that the notch (24) has a continuous recess (26).

6. A quick joint (10) according to any one of claims 1 to 5, A quick coupling (10) characterized in that a movable power coupling portion (12) is supported on a quick coupling portion attached via two spaced apart carrier elements (30) and is disposed between the carrier elements (30), each of the carrier elements (30) having a centering element (20).

7. A quick joint (10) according to claim 6, 1. A quick joint (10), characterized in that the centering elements (20) are formed in the shape of a pin and each of them cooperates with a retaining element (22) according to any one of claims 1 to 5, the retaining element (22) being formed in or inside a carrier block (18) of a movable joint part (12) extending substantially at a right angle between the carrier elements (30).

8. In the quick joint (10) according to claim 7, A quick joint (10), characterized in that the pin-shaped centering element (20) is conical in shape and is attached via its narrow end to a carrier element (30).

9. In the quick joint (10) according to claim 7 or 8, The quick joint (10) is provided with at least four centering elements (20) and at least four holding elements (22), each of the carrier elements (30) having at least two centering elements (20), one of which is connected to the carrier element (30) by a fixed support and the other of which is connected to the carrier element (30) by a loose support, such that the two centering elements (20) form a fixed-loose support device.

10. A quick joint (10) according to any one of claims 7 to 9, A quick coupling (10) characterized in that a power coupling (11) of a movable power coupling section (12) is arranged on a side of a carrier block (18) away from a movable support section of the quick coupling section, and is configured to automatically couple with another power connector arranged thereon to establish a power circuit connection when coupled to another power coupling section.

11. A quick joint (10) according to any one of claims 1 to 10, A quick coupling (10) is characterized in that a movable power coupling part (12) is disposed in a quick coupling part of a tool and is aligned so that the coupling of the power coupling parts connected by a linear guide (14) is performed substantially along a horizontal line.

12. A working machine comprising a quick coupling part (10) according to any one of claims 1 to 11.

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