coupling device and mobile work machine

Abstract

Coupling device (40) for connecting an attachment (26) to a mobile working machine (10), wherein the coupling device (40) comprises the following: - a mounting interface (60) for mounting on a boom (22) of a mobile working machine (10), - an attachment interface (62) for the detachable mounting of an attachment (26), which has a frame (140) and a locking unit (80) for the attachment (26), wherein the locking unit (80) has a cylinder arrangement (82) for actuation which is fluidically coupled to a locking fluid path (254), - a housing (170) that contains one or more cylinders (260) of the cylinder arrangement (82) and that is movable relative to the frame (140) when actuated, and - at least one working fluid path (280) for the attachment (26), which opens into a pressure medium supply port (180) at the housing (170), to which a fluid line of the attachment (26) can be coupled, wherein the at least one working fluid path (280) extends between a connecting piece (172) fixed to the frame (140) and the housing (170), wherein a fluid-conducting pipe section (182) is arranged between the connecting piece (172) and the housing (170), through which the working fluid path (280) extends, and wherein the pipe section (182) is slidably mounted in a recess (178) in the housing (170) or in the connecting piece (172) in order to compensate for a relative movement (188) between the housing (170) and the connecting piece (172), characterized by a pressure relief arrangement (250), which relieves at least one working fluid path (280),when the housing (170) and the connecting piece (172) move towards each other when the locking unit (80) is actuated.

Description

[0001] The present disclosure relates to a coupling device for connecting an attachment to a mobile working machine, comprising a mounting interface for mounting on a boom of a mobile working machine, an attachment interface for the detachable reception of an attachment, a frame, and a locking unit for the attachment, wherein the locking unit comprises a cylinder arrangement for actuation which is fluidically coupled to a locking fluid path, a housing which accommodates one or more cylinders of the cylinder arrangement and which is movable relative to the frame during actuation, and at least one working fluid path for the attachment which opens into a pressure medium supply port at the housing to which a fluid line of the attachment can be coupled, wherein the at least one working fluid path extends between a connecting piece which is fixed to the frame and the housing.wherein a fluid-conducting pipe section is arranged between the connector and the housing, through which the working fluid path extends, and wherein the pipe section is slidably mounted in a recess in the housing or in the connector to compensate for a relative movement between the housing and the connector.

[0002] EP 4 328 387 A1 describes various embodiments of such coupling devices in which the housing, which contains (at least partially) the at least one cylinder arrangement, moves relative to the frame of the mounting interface when the locking unit is actuated to secure or release an attachment. A rotary feedthrough allows several fluid paths to be safely guided into the housing, regardless of the relative position of the attachment interface relative to the mounting interface. These fluid paths can include at least one locking fluid path and at least one working fluid path.

[0003] Another design of a coupling device is known, for example, from EP 3 954 835 A2.

[0004] Coupling devices serve, for example, as quick couplers for attachments on mobile machinery. This reduces setup time. Coupling devices can provide additional degrees of freedom, such as rotation and / or swiveling motion, which may not be available when the attachment is directly mounted to an interface on the machine.

[0005] The coupling devices typically include a mounting interface with a fluidically actuated locking unit that secures a mounted attachment to the mounting interface. For this purpose, a pressure medium (e.g., hydraulic oil, compressed air, or the like) must be supplied to the locking unit. This is achieved via the locking fluid path. However, if the coupling device provides a rotational degree of freedom, it must be ensured that the pressure medium can be supplied to the locking unit regardless of its current rotational position. Rotary unions are used for this purpose.

[0006] Furthermore, it is conceivable to provide additional fluid channels and, if necessary, other channels for transmitting (electrical) energy and / or signals at the attachment interface, particularly by utilizing the rotary union. This allows for additional degrees of freedom in the attachment, for example, in the case of a gripper, tongs, shears, a vibratory plate, a grinding tool, a hammer tool, or the like. Attachments can be supplied with fluidic and / or electrical energy as required. Furthermore, communication with attachments is possible as needed, for example, for control purposes, signal transmission, data acquisition, and the like. Fluid paths for supplying the attachments can be referred to as working fluid paths.

[0007] The mounting interface includes, for example, a frame that supports the locking unit. The locking unit includes, for example, a housing that is movable relative to the frame. The housing can contain one or more actuators (cylinder assemblies), which are designed, for example, as hydraulic cylinders. In other words, the housing contains a cylinder chamber. In this way, for example, when using one actuator, both a locking element of a first mounting and a locking element of a second mounting can be actuated. If this housing now has a hydraulic fluid supply port (for attachments), this hydraulic fluid supply port would also move relative to the frame of the mounting interface.

[0008] If the housing moves relative to the frame when the locking unit is actuated, this can lead to undesirable effects on at least one working fluid path. When the locking unit is actuated, the working fluid path is regularly blocked on both the inlet and outlet sides. This occurs, for example, when no line is connected to the provided hydraulic supply connections. Furthermore, the machine's hydraulic system typically blocks the working fluid path on the inlet side if no attached implement with the corresponding functionality is actively being used.

[0009] In other words, the hydraulic fluid in the working fluid path is often trapped under high pressure during the locking or unlocking of the locking unit. Since the hydraulic fluid supply ports are typically located on the housing, the movement of the housing relative to the frame must also be compensated for in the working fluid paths. This can be achieved, for example, by means of fluid-conducting tubing sections through which the respective working fluid path extends. The tubing sections can compensate for the relative movement between the housing and the frame if the immersion depth of the tubing sections adjusts accordingly with respect to a recess when the locking unit is actuated.

[0010] However, it has been shown that this can lead to a further increase in the pressure of the hydraulic fluid trapped in the working fluid path if the pipe sections are inserted deeper into their respective recesses. This regularly results in a reduction in volume and consequently further compression of the hydraulic fluid. The hydraulic fluid is only minimally compressible. Likewise, the pipe itself has only minimal compressibility. Therefore, comparatively small changes in volume lead to a significant increase in pressure.

[0011] This increases the force required to actuate the locking mechanism. In some cases, the increased pressure can even lead to leaks and / or damage, for example, to seals and similar components. Depending on the specific situation, the movement of the housing towards the frame may even be blocked if the actuation forces become too high due to compression.

[0012] Against this background, the present disclosure aims to provide a coupling device for connecting an attachment to a mobile work machine, the locking unit of which can be operated reliably and reproducibly. In particular, malfunctions or even a blockage of the locking unit should be effectively prevented. The function of the coupling device should also be permanently guaranteed in everyday operation. This should be achieved, if possible, without any structural modifications to the on-board hydraulics of the work machine.

[0013] This task is solved in the coupling device mentioned at the beginning by a pressure relief arrangement that relieves at least one working fluid path when the housing and the connecting piece move towards each other when the locking unit is actuated.

[0014] The task of revelation is thus solved.

[0015] As disclosed, the pressure relief arrangement ensures that no potentially harmful pressure increase occurs in at least one working fluid path. This guarantees the functionality of the locking unit. The durability of the coupling devices and the associated hydraulic system can be optimized.

[0016] The present disclosure relates to coupling devices in which the housing of the locking unit, which contains the cylinder assembly (in particular a cylinder chamber thereof), is slidably mounted relative to a frame of the mounting interface. This "floating" mounting of the housing allows the locking unit to be used to actuate two opposite receptacles.

[0017] In such a design, if the hydraulic fluid (usually hydraulic fluid) is fed into the housing without flexible hoses, pipe sections are provided to compensate for relative movement. These sections extend into recesses and are slidably mounted within them. This ensures that any changes in the distance between the housing and the opposite part (here: the connecting piece) for the fluid paths can be compensated for. However, the insertion of the pipe sections into their respective recesses reduces the volume there, resulting in a pressure increase in the hydraulic fluid if no special precautions are taken. The pressure relief device prevents an undesirable increase in pressure. In this way, potentially disruptive influences on the actuation of the locking unit are avoided.

[0018] The pressure relief device is particularly effective when at least one section of pipe enters a corresponding recess to displace volume. This reduces the actuating force required to operate the locking unit, potentially improving operational reliability and wear characteristics.

[0019] The pressure relief device can also be referred to as a pressure-relieving circuit. This device is particularly suitable for hydraulic systems where the working fluid paths for any attachments are blocked when the locking unit (via at least one locking fluid path) is actuated. In designs where the fluid is "trapped" in the working fluid paths during this operating mode, a potentially disruptive pressure increase can occur as the pipe sections are inserted into the recesses. The pressure relief device counteracts this pressure increase.

[0020] According to an exemplary embodiment, the at least one working fluid path is coupled to a return line upon which the pressure relief arrangement acts, wherein the pressure relief arrangement comprises a pressure relief valve that is arranged between the at least one working fluid path and the return line and has a pressure relief position. The coupling refers to a fluidic coupling. The arrangement of the pressure relief valve between the working fluid path and the return line refers to a fluidic intermediate circuit.

[0021] In other words, in the pressure relief position, a kind of bypass is provided through which pressurised fluid can flow towards the return line if the pressure in the working fluid path is too high.

[0022] According to another exemplary embodiment, the pressure relief valve is brought into the pressure relief position by a control device when the locking unit is actuated via the locking fluid path in order to generate a movement of the housing towards the connecting piece.

[0023] Depending on the design of the locking unit, this can occur when opening or closing the locking unit to release or secure the attachment.

[0024] According to another exemplary embodiment, the pressure relief valve is a magnetically actuated directional control valve that, in addition to the pressure relief position, has a closed position. For example, the pressure relief valve is a 2 / 2 directional control valve with two ports and two positions, where the first port is connected to some or all of the working fluid paths and the second port is connected to the return line. In this way, pressure relief can be provided with only one pressure relief valve for some or all of the working fluid paths where a pressure increase is likely due to the movement of the pipe section.

[0025] In addition to the pressure relief position, the pressure relief valve can have a blocking position in which this direction is blocked for the hydraulic fluid. When the respective attachment is used with the working fluid path, the hydraulic fluid flows through the working fluid path through a corresponding consumer (degrees of freedom) on the attachment and from there back to the tank via the return line, without passing through the pressure relief valve.

[0026] For example, in the closed position, a check valve of the pressure relief valve is effective, preventing backflow from the working fluid path into the return line. The check valve may also be spring-loaded.

[0027] According to a further exemplary embodiment, the cylinder arrangement of the locking unit has at least one double-acting cylinder or two single-acting cylinders, wherein the locking fluid path has a first line and a second line coupled to the cylinder or cylinders, wherein in particular a locking control valve for reversing the direction is provided, and wherein the pressure relief valve is moved into the pressure relief position when the locking control valve is moved into a position in which the housing and the connecting piece move towards each other.

[0028] According to this design, the pressure relief valve is only moved into the pressure relief position if there is actually a risk of pressure increase due to the relative movement between the housing and the connecting piece.

[0029] The use of double-acting cylinders in the locking unit has the advantage that movement in two directions (retraction and retraction) can be controlled with just one cylinder. In principle, a comparable function can also be achieved with two single-acting cylinders operating in opposite directions. The cylinders can incorporate various return mechanisms (springs, hydraulic return, mechanical return).

[0030] According to another exemplary embodiment, several working fluid paths are provided, each having a fluid-conducting pipe section that is slidably mounted in a recess in the housing or in the connecting piece in order to compensate for the relative movement between the housing and the connecting piece.

[0031] If multiple pipe sections are used that are displaced in corresponding recesses during relative movement, the potentially disruptive influence of the pressure increase during immersion of the pipe sections increases. The pressure relief arrangement can remedy this for several or all of the working fluid paths by providing appropriate pressure relief.

[0032] According to another exemplary embodiment, the locking unit has two parallel-acting cylinders arranged at a distance from each other within the housing. The two cylinders are positioned, for example, on the right and left sides of the housing to lock or release pairwise right and left recesses of the locking unit. Several hydraulic supply connections for attachments can be provided between the two cylinders, supplied via working fluid paths extending through a pipe section designed to compensate for relative movement between the housing and the connecting piece.

[0033] According to another exemplary embodiment, the coupling device further comprises a rotary union, wherein the locking fluid path and the at least one working fluid path extend along the rotary union to compensate for one degree of rotational freedom about a rotational axis. The rotary union serves as a hydraulic rotary union (although an electrical rotary union is also conceivable). The rotary union supplies the locking unit and the at least one pressure medium supply connection at the housing. The rotary union ensures the fluidic supply without prejudice to the degree of rotational freedom provided by a corresponding rotational axis. The rotary union extends along the rotational axis.

[0034] According to another exemplary embodiment, the rotary feedthrough for the pressure medium supply is coupled to the pressure medium supply connection and the locking unit without hoses. The connection in each case is fluidic. Eliminating hose lines increases the robustness of the coupling device. Furthermore, this method increases the stiffness of the locking fluid path and at least one working fluid path, thereby ensuring reliable and reproducible fluidic functions.

[0035] According to another exemplary embodiment, the pressure relief device is arranged in an inlet block mounted on the rotary feedthrough. In this embodiment, the pressure relief device is located on the inlet side of the rotary feedthrough. This allows the pressure relief valve to be integrated with minimal additional construction effort. Any pressure increases in at least one working fluid path also affect the inlet block, enabling pressure relief there.

[0036] According to another exemplary embodiment, the pressure relief device is located in the connecting piece. In this embodiment, the pressure relief device (in particular its pressure relief valve) is located on the outlet side at the rotary feedthrough, i.e., between the rotary feedthrough and the housing. The pressure relief valve can be controlled via electrical lines, which, for example, also extend across the rotary feedthrough.

[0037] According to another exemplary embodiment, the pressure relief device is located inside the housing. The pressure relief device can also provide pressure relief there.

[0038] According to another exemplary embodiment, the pipe section is fixed to the housing, with the pipe section dipping into the connector as the housing and the connector move towards each other. In other words, volume is displaced in the connector as the housing and the connector are moved towards each other.

[0039] According to another exemplary embodiment, the pipe section is fixed to the connector, with the pipe section dipping into the housing as the housing and the connector move towards each other. In other words, volume is displaced within the housing as the housing and the connector are moved towards each other.

[0040] According to another exemplary embodiment, the pipe section is suspended between the housing and the connecting piece, without any fixing (with respect to its axial position) of the pipe section relative to either element. In this way, too, the pipe section can compensate for the relative movement between the housing and the connecting bridge.

[0041] According to another exemplary embodiment, the pipe section and the pressure medium supply connection of at least one working fluid path are aligned coaxially with each other. In this way, the housing and the connecting piece can be designed to be comparatively compact. The pipe section and the pressure medium supply connection are oriented parallel to at least one cylinder of the cylinder arrangement of the locking unit.

[0042] According to another exemplary embodiment, the pipe section is structurally integrated into the pressure medium supply connection. This eliminates the need to fix the pipe section separately within the housing. In yet another exemplary embodiment, the pipe section and the flange of the pressure medium supply connection are formed as a single unit. This reduces the number of parts required. The integrated design is particularly advantageous when the pipe section and pressure medium supply connection are coaxially aligned.

[0043] According to another exemplary embodiment, the coupling device further comprises a rotary section arranged between the mounting interface and the attachment interface, with a rotary drive for generating a relevant rotation between the mounting interface and the attachment interface about a rotational axis. In this way, the coupling device provides an additional degree of freedom for the attachment. The hydraulic fluid supply can be provided via the rotary union. The rotary union is oriented concentrically to the rotational axis.

[0044] According to another exemplary embodiment, the coupling device further comprises a pivoting section with a pivoting drive for generating a pivoting movement between the mounting interface and the attachment interface about a pivot axis. In this way, the coupling device provides an additional degree of freedom for the attachment. In exemplary embodiments, the pivoting section is arranged between the mounting interface and the rotary section (or the subsequent attachment interface). In other words, during a pivoting movement in the pivoting section, the rotary section and the attachment interface pivot together relative to the mounting interface.

[0045] According to another aspect, the present disclosure relates to a mobile working machine with a chassis, a superstructure supported by the chassis, and at least one articulated boom which carries a coupling device according to at least one of the embodiments described herein for coupling an attachment.

[0046] The boom is designed, for example, as an articulated arm. In one exemplary embodiment, the boom, together with the superstructure, is movable relative to the chassis (for example, a slewing ring between the chassis and superstructure). In another exemplary embodiment, the boom is movable relative to the superstructure, in particular pivotable. For example, the machine has an onboard hydraulic system with a hydraulic pump, pressure generator, and / or pressure accumulator. In this way, fluidic energy can be supplied to the coupling device and, if applicable, to the attachment via corresponding lines extending along the boom.

[0047] Mobile machinery includes, for example, excavators (crawler excavators, wheeled excavators, and the like). Mobile machinery can encompass construction equipment, agricultural and forestry vehicles. Examples include wheel loaders, excavators, tractors, towing vehicles in general, and trailers. Mobile machinery can be equipped with its own drive system. However, it is also possible to design mobile machinery without its own drive system.

[0048] Many different types of attachments are known, such as buckets, shovels, grapples, hammers, shears, magnets, vibratory plates, grinding heads, milling machines, and the like. Attachments can have their own degrees of freedom, for example, for opening and closing a grapple or demolition shears.

[0049] It is understood that the features of the disclosure mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present disclosure.

[0050] Further features and advantages will become apparent from the following description of several preferred embodiments with reference to the drawings. These show: Fig. 1: A side view of an exemplary design of a mobile work machine in the form of a crawler excavator; Fig. 2 a perspective view of an embodiment of a coupling device; Fig. 3: An enlarged cutaway view of the coupling device according to Fig. 2; Fig. 4: A cutaway detail view of the coupling device with rotary feedthrough; and Fig. 5: A schematic view of a hydraulic design of the coupling device to illustrate a pressure relief arrangement.

[0051] Fig. Figure 1 shows a simplified schematic representation of a mobile work machine designated as 10. In the exemplary embodiment, the work machine 10 is designed as an excavator, for example as a crawler excavator. Other designs are, however, conceivable.

[0052] The machine 10 comprises a chassis 12 that supports a superstructure 14. In exemplary embodiments, the superstructure 14 is rotatable relative to the chassis 12 about a vertically oriented axis. The superstructure 14 houses, for example, a hydraulic power unit 16, which serves to supply the hydraulic fluid. This is usually hydraulic oil, which is pressurized by the hydraulic power unit 16. It is understood that the hydraulic power unit 16 may also include a pressure accumulator.

[0053] In the exemplary embodiment, a knuckle arm 20 with several degrees of freedom is mounted on the superstructure 14. The knuckle arm 20 can also generally be referred to as a boom 22. The knuckle arm 20 extends between the superstructure 14 and an attachment 26. In the exemplary embodiment, the attachment 26 is designed as a bucket 28. This is not to be understood as a limitation. Other types of attachments 26 are conceivable.

[0054] It is generally conceivable to attach the attachment 26 directly to the boom 22 of the mobile work machine 10. The attachment 26 typically has connecting elements, such as connecting bolts and / or coupling rods. At the end of the boom 22 furthest (kinematically) from the superstructure 14, a suitable interface for directly receiving the attachment 26 is usually provided. However, such direct mounting is not suitable for quick changes of the attachment 26. Furthermore, such direct mounting does not allow any additional degrees of freedom (rotation and / or pivoting) between the attachment 26 and the boom 22.

[0055] So-called quick couplers are known, which are installed as an interface between the boom 22 and the attachment 26. One such quick coupler is known, for example, from EP 3 954 835 A2.

[0056] In the exemplary embodiment according to Fig. In Figure 1, a coupling device 40 serves as a quick coupler. The coupling device 40 is designed, by way of example, as a so-called tiltrotator 42, without this being to be understood as a limitation. Accordingly, the coupling device 40 can, at least in exemplary embodiments, provide a rotation axis 46 (compare the curved double arrow 48 to illustrate the rotational movement) between the attachment 26 and the boom 22. In exemplary embodiments, a pivot axis 50 (compare the curved double arrow 52 to illustrate the pivoting movement) is also provided between the attachment 26 and the boom 22. In this way, the range of applications of the mobile work machine 10 is broadened when suitable attachments 26 are installed. Overall, the performance potential of the mobile work machine 10 can be increased.

[0057] With reference to the Fig. Sections 2-5 illustrate various aspects of the design of a coupling device designated as 40 in total.

[0058] The coupling device 40 is designed in its basic structure similarly to the coupling devices described in EP 4 328 387 A1.

[0059] The coupling device 40 has, in the manner already described above, a mounting interface 60 for mounting on a mobile work machine 10; furthermore, an attachment interface 62 is provided for receiving an attachment device 26, see also Fig. 1. A swivel section 64 and a rotary section 66 are arranged between the mounting interface 60 and the attachment interface 62.

[0060] The mounting interface 62 is rotatable relative to the assembly interface 60 about a rotary axis 46; compare also the rotary movement indicated by 48. The mounting interface 62 is pivotable relative to the assembly interface 60 about a swivel axis 50; compare also the swivel movement indicated by 52. ​​For receiving and securing attachments 26 ( Fig. 1) A locking unit 80 serves to secure a cylinder arrangement 82 (in Fig. 2 (concealed) which serves as an actuator. The locking unit 80 allows attachments 26 to be mounted and secured on a first receptacle 84 and a second receptacle 86 of the mounting interface 62. For a description of this functionality, reference is again made to EP 4 328 387 A1 and EP 3 954 835 A2.

[0061] The pivoting movement 52 is generated by a pivoting drive 90, which is assigned to the pivoting section 64 and pivots a pivoting bridge 92 assigned to the mounting interface 62 relative to a mounting bracket 70 assigned to the mounting interface 60. In the exemplary embodiment, the pivoting drive 90 comprises two actuators 96, which are coupled to the pivoting bridge 92 via a first coupling point 104 and to the mounting bracket 70 via a second coupling point 106. The actuators 96 are typically designed as cylinders so that the distance between the two coupling points 104, 106 can be varied. In this way, the pivoting movement 52 can be generated about the pivot axis 50 running through pivot bearings 110.

[0062] The Fig. 2 and Fig. Figure 3 further illustrates a rotary drive 120, which is assigned to the rotary section 66. The rotary drive 120 has a stator 122 and a rotor 124. The stator 122 is rigidly connected to the pivot bridge 92 with respect to any rotational movements 48 about the axis of rotation 46. The rotor 124, on the other hand, is rotatable relative to the pivot bridge 92 about the pivot axis 46. The rotor 124 includes, for example, a slewing ring 130, which supports a frame 140. The frame 140 is part of the mounting interface 62.

[0063] The coupling device 40 comprises a rotary feedthrough 146 for hydraulic lines, which in the exemplary embodiment is oriented concentrically to the axis of rotation 46. The rotary feedthrough 146 comprises a center 158 and a sleeve 164, between which relative rotation is possible. In the exemplary embodiment according to the Fig. 2 and Fig. 3. The casing 164 is rotatable together with the rotary ring 130 when the frame 140 with the locking unit 80 mounted on it is also rotated about the axis of rotation 46. The center 158 of the rotary union 146 remains stationary during this rotation, so that no rotation of the center 158 about the axis of rotation 46 is possible. In this way, channels 166 for fluid guidance can form a fluidic connection between an inlet of the rotary union 146 (in the Fig. 2 and Fig. 3 not explicitly shown) and provide the locking unit 80.

[0064] In alternative embodiments, the center 158 of the rotary feedthrough 146 is rotatable. The center then serves as the rotor, and the casing 164 forms the stator. The input block 148 is then attached to the casing 164, which would serve as the input to the rotary feedthrough 146.

[0065] The locking unit 80 comprises a housing 170, which also serves as a connection block for the hydraulic fluid supply. The housing 170 is fluidically connected to a connecting piece 172, which, together with the sleeve 164 of the rotary feedthrough 146, can be rotated about the axis of rotation 46. The channels 166 are connected to the housing 170 via fluid paths 176. In this way, a hydraulic fluid supply to the cylinder assembly 82 of the locking unit 80 can be provided.

[0066] The housing 170 also provides a pressure medium supply for attachments via one or more pressure medium supply connections 180. Attachment lines 26 ( Fig. 1) can connect there. It is understood that usually several channels 166 and, accordingly, several fluid paths 176 are connected to the housing 170 via the rotary feedthrough 146. In Fig. Figure 3 merely illustrates a cover 204 for the pressure medium supply connection 180, which protects and covers it as needed.

[0067] A pipe section 182 is arranged between the connecting piece 172 and the housing 170, providing a fluidic connection between the housing 170 and the connecting piece 172. It should be noted that a sliding movement 188 of the housing 170 relative to the frame 140, and thus also relative to the connecting piece 172, occurs when the locking unit 80 is actuated via its cylinder assembly 82. For example, the sliding movement 188 is oriented perpendicular to the axis of rotation 46.

[0068] This sliding movement 188 creates a variable distance between the housing 170 and the connecting piece 172. The pipe section 182 bridges this distance and compensates for any fluctuations. In the exemplary embodiment, the pipe section 182 is fixedly arranged in the housing 170 via a seat 190. One end of the pipe section 182 opens into the housing, pointing towards the pressure medium supply connection 180. At an end 192 facing away from the housing 170, the pipe section 182 engages in a recess 178 in the connecting piece 172. In this way, the fluid path 176 can be connected to the pressure medium supply connection 180.

[0069] The immersion depth of the pipe section 182 in the recess 178 in the connecting piece 172 depends on the respective distance between the housing 170 and the connecting piece 172. It is understood that the fixed fit of the pipe section 182 in the housing 170 and the sliding fit of the pipe section 182 in the connecting piece 172 are designed to be as fluid-tight as possible by suitable seals and designs.

[0070] Fig. Figure 3 further illustrates a coaxial arrangement of the pipe section 182 with respect to the pressure medium supply connection 180. In the exemplary embodiment, the coaxial arrangement also includes the recess 178 in the connecting piece 172. A longitudinal axis 194 extends between the recess 178, the pipe section 182, and the pressure medium supply connection 180. In this way, the housing 170 of the locking unit 80 can be designed to be particularly compact. Ideally, deflections in the fluid path 176 can be avoided.

[0071] Fig. Figure 3 illustrates an embodiment in which the pipe section 182 is fixedly arranged in the housing 170 and slidably in the connecting piece 172. It is understood that a reverse arrangement is also conceivable, in which the pipe section 182 is arranged in the connecting piece 172 and slidably in the housing 170. EP 4 328 387 A1 illustrates such an embodiment. Finally, designs are also conceivable in which the pipe section 182 is floatingly mounted, i.e., slidably arranged in both the connecting piece 172 and the housing 170.

[0072] In one exemplary embodiment, the pipe section 182 is structurally integrated into the pressure medium supply connection 180. Consequently, the pipe section 182 does not need to be separately fixed in the housing 170. In particular, the pipe section 182 can be formed as a single piece with a flange of the pressure medium supply connection 180.

[0073] Fig. 4 is based on the representations according to Fig. 2 and Fig. 3 and illustrates a lateral section through the axis of rotation 48. Fig. Figure 4 shows the rotary union 146 with an inlet block 148 arranged on it, which contains hydraulic connections, associated lines and optionally hydraulic functional elements. The inlet block 148 opens into the rotary union 146. In the exemplary embodiment, the inlet block 148 sits on the center 158 of the rotary union 146, which serves as a stator. The inlet block 148 is in the Fig. 2 and Fig. 3 not shown for illustrative purposes.

[0074] The at least one pressure medium supply connection 180 (usually several are provided) is fed via a fluid path 176, which can also be referred to as the working fluid path, since it supplies pressure medium to an attachment 26 ( Fig. 1) serves.

[0075] The fluid path 176 bridges a gap between the housing 170 and the connecting piece 172. This gap is bridged by the pipe section 182. In the exemplary embodiment, the pipe section 182 is firmly seated in its seat 190 in the housing 170. With its end 192 facing away from the housing 170, the pipe section 182 extends into the recess 178 in the connecting piece 172. This ensures that, despite the relative movement (arrow 188) between the housing 170 and the connecting piece 172, a hose-free fluidic connection is maintained. Therefore, it is not necessary to install a flexible hose between the rotary feedthrough 146 and the pressure medium supply connection 180.

[0076] In Fig. Figure 4 illustrates a possible position of the pipe section 182 in the recess 178 when the housing 170 is close to the connecting piece 172. The double arrow 188 illustrates the corresponding relative movement. As the pipe section 182 moves deeper into the recess 178, it displaces a volume there, compressing the fluid in the fluid path 176. This can lead to a significant pressure increase. This can result in malfunctions and / or excessive wear. Wear can occur, in particular, due to excessive stress on installed seals, lines, and the like. Malfunctions can occur immediately if, due to the pressure increase in the fluid path 176, the cylinder assembly 82 (see Figure 4) is damaged. Fig. 2) is no longer able to move the housing 170 close enough to the connecting piece 172 to actuate the locking unit 80.

[0077] With reference to Fig. Figure 5 illustrates a pressure relief arrangement designated 250, which is intended to counteract a pressure increase in at least one working fluid path.

[0078] Fig. Figure 5 is a schematic view of a hydraulic diagram illustrating the pressure medium supply to the coupling device 40 (also referred to as a quick coupler). The system boundaries of the inlet block 148, which feeds into the (in Fig. 5 (symbolically represented) rotary feedthrough 146 opens. In the embodiment according to Fig. 4 The inlet block 148 sits on the (as stator) center 158 of the rotary feedthrough 146.

[0079] In connection with the Fig. 3 and Fig. 4 Fluid paths are generally designated with 176. Fig. Figure 5 shows that the fluid paths can include so-called locking fluid paths 254 and so-called working fluid paths 280. The locking fluid paths 254 supply the cylinder assembly 82, i.e., actuate the locking unit 80. The working fluid paths 280 supply attachments 26. The fluid paths 254 and 280 are routed into the housing 170 through the rotary feedthrough 146.

[0080] In the housing 170, the locking fluid paths 254 open into the cylinder arrangement 82, which in the exemplary embodiment has two parallel cylinders 260. Each cylinder 260 comprises a piston rod 262 and, in the exemplary embodiment, is designed as a double-acting cylinder. The cylinders 260 are assigned to a right and a left side of the mounting interface 62 in order to lock or release the opposite receptacles 84, 86. Actuation of the locking unit 80 comprises a sliding movement (double arrow 188) of the housing 170. The cylinders 260 are actuated via the locking fluid paths 254, as shown by the Fig. 5 Each of the locking fluid paths 254 serves to open the quick coupler (SW-O) and to close the quick coupler (SW-C).

[0081] A locking control valve 266 is used to switch between open and closed positions. In the exemplary embodiment, the locking control valve 266 is controlled by a control device 270, which is coupled to an actuator of the locking control valve 266 via a control line 272.

[0082] The working fluid paths 280 serve to supply the pressure medium supply connections 180 at the housing 170. Attachments 26 can be connected there to provide corresponding degrees of freedom for further functions. This includes, in the exemplary embodiment according to Fig. 5 multiple working fluid paths 280, which, for example, support functions of attachments 26 such as hammer (H), shear (S), gripping / rotating (GD). In this way, the coupling device 40 can supply a wide variety of attachments 26.

[0083] The working fluid paths 280 are normally blocked when the cylinder assembly 82 is actuated to open or close the locking unit 80. This leads to the situation associated with Fig. Figure 4 illustrated the pressure increase in the working fluid paths 280 when the cylinder arrangement 82 is actuated via the locking fluid paths 254 and the pipe sections 182 are immersed in their respective recesses 178.

[0084] At least some of the working fluid paths 280 are coupled to a return line 282, which allows free return flow into the tank when the respective function (H, S, GD, etc.) is used. In the exemplary embodiment, there is a common return line for several of the working fluid paths 280. To prevent (fluidic) short circuits, the working fluid paths 280 in the exemplary embodiment each have check valves 286, which define the flow direction towards the return line 282 and thus prevent a flow of pressurized fluid to other working fluid paths 280 (short circuit).

[0085] For pressure relief, the pressure relief arrangement 250 has a pressure relief valve 284, which in the exemplary embodiment is designed as a 2 / 2-way valve with two ports and two switching positions. The pressure relief valve 284 has a closed position (in Fig. 5. The valve has two positions: a closed position (with the check valve) and a pressure relief position (opening position). In the closed position, pressure relief from the working fluid paths 280 towards the return line 282 is not permitted. In the pressure relief position, pressure relief from the working fluid paths 280 towards the return line 282 is permitted.

[0086] This is the case, for example, when the pipe section 182 displaces volume in the recess 178 during the movement of the housing 170 relative to the connecting piece 172, thereby significantly increasing the pressure in the respective working fluid path 280. The pressure relief arrangement 250 with the pressure relief valve 284 can thus significantly improve the functional reliability of the locking unit 80.

[0087] The pressure relief valve 284 is coupled to the control unit 270 via a control line 274. In this way, the control unit 270 can actuate an actuator of the pressure relief valve 284 to move it into the pressure relief position or the closed position. For example, the control unit 270 moves the pressure relief valve 284 into the pressure relief position when the cylinder assembly 82 is actuated to actuate the locking unit 80, thereby moving the housing 170 towards the connecting piece 172.

[0088] In the exemplary embodiment, the pressure relief valve 284 of the pressure relief assembly 250 is integrated into the inlet block 148, which is mounted on the rotary feedthrough 146. It is understood that the pressure relief valve 284 can alternatively also be installed in the connecting piece 172 or in the housing 170 (see relevant sections). Fig.4) The pressure relief valve 284 can generally be provided where the working fluid paths 280 run, in order to act upon them. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 4 328 387 A1 [0002, 0058, 0060, 0071] EP 3 954 835 A2 [0003, 0055, 0060]

Claims

[1] Coupling device (40) for connecting an attachment (26) to a mobile working machine (10), wherein the coupling device (40) comprises the following: - a mounting interface (60) for mounting on a boom (22) of a mobile working machine (10), - an attachment interface (62) for the detachable mounting of an attachment (26), which has a frame (140) and a locking unit (80) for the attachment (26), wherein the locking unit (80) has a cylinder arrangement (82) for actuation which is fluidically coupled to a locking fluid path (254), - a housing (170) that contains one or more cylinders (260) of the cylinder arrangement (82) and that is movable relative to the frame (140) when actuated, and - at least one working fluid path (280) for the attachment (26) which opens into a pressure medium supply port (180) at the housing (170) to which a fluid line of the attachment (26) can be coupled, wherein the at least one working fluid path (280) extends between a connecting piece (172) fixed to the frame (140) and the housing (170), wherein a fluid-conducting pipe section (182) is arranged between the connecting piece (172) and the housing (170) through which the working fluid path (280) extends, and wherein the pipe section (182) is slidably mounted in a recess (178) in the housing (170) or in the connecting piece (172) in order to compensate for a relative movement (188) between the housing (170) and the connecting piece (172), characterized bya pressure relief arrangement (250) that relieves the at least one working fluid path (280) when the housing (170) and the connecting piece (172) move towards each other when the locking unit (80) is actuated. [2] Coupling device (40) according to claim 1, wherein the at least one working fluid path (280) is coupled to a return line (282) on which the pressure relief arrangement (250) acts, and wherein the pressure relief arrangement (250) has a pressure relief valve (284) which is arranged between the at least one working fluid path (280) and the return line (282) and has a pressure relief position. [3] Coupling device (40) according to claim 2, wherein the pressure relief valve (284) is brought into the pressure relief position by a control device (270) when the locking unit (80) is actuated via the locking fluid path (254) to generate a movement of the housing (170) towards the connecting piece (172). [4] Coupling device (40) according to claim 2 or 3, wherein the pressure relief valve (284) is a directional control valve with magnetic actuation which has a blocking position in addition to the pressure relief position. [5] Coupling device (40) according to one of claims 2-4, wherein the cylinder arrangement (82) of the locking unit (80) comprises at least one double-acting cylinder (260) or two single-acting cylinders, wherein the locking fluid path (254) comprises a first line (SW-C) and a second line (SW-O) coupled to the cylinder (260) or cylinders, wherein in particular a locking control valve (266) is provided for reversing the direction, and wherein the pressure relief valve (284) is moved into the pressure relief position when the locking control valve (266) is moved into a position in which the housing (170) and the connecting piece (172) move towards each other. [6] Coupling device (40) according to one of claims 1-5, wherein several working fluid paths (280) are provided, each having a fluid-conducting tube section (182) which is slidably mounted in a recess (178) in the housing (170) or in the connecting piece (172) to compensate for the relative movement (188) between the housing (170) and the connecting piece (172). [7] Coupling device (40) according to one of claims 1-6, wherein the locking unit (80) has two parallel acting cylinders (260) which are spaced apart from each other in the housing (170). [8] Coupling device (40) according to one of claims 1-7, further comprising a rotary feedthrough (146), wherein the locking fluid path (254) and the at least one working fluid path (280) extend along the rotary feedthrough (146) to compensate for one degree of rotational freedom about a rotational axis (46). [9] Coupling device (40) according to claim 8, wherein the rotary feedthrough (146) for pressure medium supply is coupled without hoses to the pressure medium supply connection (180) and the locking unit (80). [10] Coupling device (40) according to claim 8 or 9, wherein the pressure relief arrangement (250) is arranged in an input block (148) which is arranged on the rotary feedthrough (146). [11] Coupling device (40) according to one of claims 1-10, wherein the pressure relief arrangement (250) is arranged in the connecting piece (172) or in the housing (170). [12] Coupling device (40) according to one of claims 1-11, wherein the tube section (182) is fixed to the housing (170) and dips into the connecting piece (172) when the housing (170) and the connecting piece (172) move towards each other. [13] Coupling device (40) according to one of claims 1-12, wherein the tube section (182) is fixed to the connecting piece (172) and dips into the housing (170) when the housing (170) and the connecting piece (172) move towards each other. [14] Coupling device (40) according to one of claims 1-13, wherein the pipe section (182) and the pressure medium supply connection (180) of at least one working fluid path (280) are aligned coaxially to each other. [15] Coupling device (40) according to one of claims 1-14, wherein the pipe section (182) is structurally integrated into the pressure medium supply connection (180) and is designed in one piece with a flange of the pressure medium supply connection (180). [16] Coupling device (40) according to one of claims 1-15, further comprising a rotary section (66) arranged between the mounting interface (60) and the attachment interface (62) with a rotary drive (120) for generating a relevant rotation between the mounting interface (60) and the attachment interface (62) about a rotational axis (46). [17] Coupling device (40) according to one of claims 1-16, further comprising a pivoting section (64) with a pivoting drive (90) for generating a pivoting movement between the mounting interface (60) and the attachment interface (62) about a pivoting axis. [18] Mobile working machine (10) comprising a chassis (12), a superstructure (14) supported by the chassis (12), and at least one articulated boom (22) which carries a coupling device (40) according to one of claims 1-17 for coupling an attachment (26).

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