Attachment, vehicle combination, computer program product and use of a control unit

Abstract

Attachment (67), in particular front loader (4), with a) a hydraulic system (26) with at least two hydraulic actuators (59) and b) an implement bus system (27) which has an implement bus interface (32) via which the implement bus system (27) can be connected to a work vehicle bus system (15), c) wherein the implement bus system (27) is connected directly or via a control unit (34) of the implement (67) ca) is coupled with pressure sensors (38, 39, 41, 42) in such a way that measurement signals from the pressure sensors (38, 39, 41, 42) or signals dependent thereon can be transmitted via the implement bus system (27), and / or cb) is coupled with motion sensors (40, 43) in such a way that measurement signals from the motion sensors (40, 43) or signals dependent thereon can be transmitted via the attachment bus system (27).

Description

TECHNICAL AREA OF INVENTION

[0001] The invention relates to a work vehicle. The work vehicle is, for example, a tractor, an excavator, a wheel loader, or a similar carrier vehicle, which has a hydraulic supply system capable of powering hydraulic actuators. The work vehicle itself may have permanently mounted hydraulic components. Furthermore, the work vehicle preferably has an interface to which various attachments can be mounted. The hydraulic supply system preferably includes a central hydraulic pump that provides a flow of pressurized hydraulic fluid. Preferably, the hydraulic supply system further includes a tank into which returning hydraulic fluid from hydraulic actuators can enter, and from which the central hydraulic pump then pumps the hydraulic fluid.

[0002] The invention further relates to an attachment, which may be, for example, a front loader, a wheel loader bucket, a mower, a plow, or similar equipment. Such attachments preferably also have hydraulic functions, which are implemented by hydraulic actuators on the attachment. The hydraulic actuators on the attachment may, for example, be hydraulic actuating cylinders. In some embodiments, the hydraulic actuating cylinders may be differential cylinders with opposing pressure chambers. In other embodiments, several hydraulic actuating cylinders may be connected together to form a (common) hydraulic actuator. In principle, various types of hydraulic actuators may be provided on the attachment.

[0003] The invention also relates to a particular use of a control unit of an attachment or a vehicle combination.

[0004] In the following, particular reference is sometimes made to the design of the work vehicle as a tractor and the design of the attachment as a front loader that can be mounted on the tractor, whereby the same may then apply to a different design of the work vehicle and / or the attachment.

[0005] Tractors equipped with a front loader are used in agriculture or municipal services for lifting, lowering, and transporting loads. It is also possible for a tractor with a front loader to function as a wheel loader.

[0006] Common front loaders feature a boom with a column that can be mounted to a mounting bracket, particularly a tractor's mounting tower. At the end of the boom furthest from the column, the front loader has a tool attachment point, allowing it to be detachably connected to a tool (such as a manure fork, bucket, pallet fork, heavy-duty fork, round bale fork, or beet basket). It is also possible to attach a lifting tool (such as a cutting shear, a box rotator, or a grapple, e.g., a plastic bale grab, a solid manure grab, or a log grab) to the front loader.

[0007] Conventional boom arms consist of a front and a rear beam. The beams are formed from steel tube profiles welded together at an angle at their opposing ends. A lifting cylinder, whose hydraulic actuation is supplied and controlled by the work vehicle, allows the boom arm to pivot around a pivot bearing located between the column and the boom arm. A tilting cylinder, also supplied and controlled by the work vehicle, allows the tool holder to be pivoted relative to the boom arm. The hydraulic actuation of the hydraulic cylinders can be controlled by the operator using levers.Alternatively, the hydraulic actuation of the hydraulic cylinders can be controlled via a joystick or a cross lever. Moving the joystick or cross lever forward and backward raises and lowers the front loader boom, while moving it right and left changes the swivel angle of the implement holder relative to the boom around a transverse axis. Additional push and / or rocker switches can control further functions, in particular the operation of an implement performing a working stroke.

[0008] The hydraulic cylinders are actuated via connecting lines between the work vehicle and the front loader, with the hydraulic fluid supplied by a hydraulic pump on the work vehicle. The hydraulic system can be controlled from the driver's seat using controls such as levers, switches, or a joystick, as well as via controls on the work vehicle and / or on the front loader. The connecting lines of the hydraulic system between the work vehicle and the front loader can be individually coupled via fittings, or a so-called "multi-coupling" can be used, which connects several or all hydraulic connections simultaneously.

[0009] The tool holder can be designed as a so-called Euro quick-change frame or as a tool holder according to one of the standards EN 12525 or ISO 24410.

[0010] Automatic coupling devices are also used, which allow the coupling of the tool holder with the tool and its locking to be achieved without the driver having to leave the driver's cab.

[0011] Parallel guidance systems can be used to coordinate the hydraulic pressures of the hydraulic cylinder for raising and lowering the boom and the hydraulic cylinder for pivoting the tool holder relative to the boom in such a way that the angle between the tool holder and the ground does not change or only changes within narrow limits during the raising and lowering of the boom.

[0012] In this technical field, the invention relates to an attachment for a work vehicle and a vehicle combination comprising a work vehicle and an attachment mounted thereon. Furthermore, the invention relates to a computer program product. STATE OF THE ART

[0013] Patent DE 10 2005 048 280 B4 of the applicant discloses prior art relating to driver-operated valves of the work vehicle for controlling the hydraulic actuation of hydraulic cylinders of the front loader, additional solenoid valves and hydraulic coupling devices for coupling connecting lines between the work vehicle and the front loader.

[0014] The applicant's patent application DE 10 2005 053 041 A1 discloses prior art relating to a front loader with a column, rigidly connected arms, a tool holder, a lifting cylinder, and a tilting cylinder. The front loader has a support leg that can be extended by means of a further hydraulic cylinder. When the support leg is extended, the front loader can be parked on the tool holder or on a tool such as a bucket and the support leg, with the center of gravity of the front loader with the tool located on the ground between the support points. However, the front loader can also extend beyond the space between the support points to allow good access to the column for coupling it to the mounting bracket of the work vehicle.

[0015] Patent DE 10 2009 046 213 B4 of the applicant discloses prior art for the design of a tool holder according to ISO 24410 and with regard to a locking device for locking the tool in the tool holder.

[0016] Patent EP 1 813 730 B1 of the applicant discloses prior art for the design of a hydraulic system for controlling a front loader and for pressure control in the hydraulic system.

[0017] The applicant's patent EP 1 903 147 B1 discloses prior art for the geometric design of the arms of a front loader and the integration of the actuation kinematics of the front loader with the hydraulic cylinders into the front loader.

[0018] The applicant's patent EP 2 840 186 B1 discloses prior art for the design of an attachment console, here in an embodiment with a so-called bone, and for the design of a locking or latching device for locking the column of the front loader to the attachment console of the tractor.

[0019] Patent EP 3 158 842 B1 discloses design possibilities for an attachment console of the work vehicle, which here is formed by two attachment towers on both sides of the work vehicle, which have longitudinally extending plate-shaped frame elements and vertically extending supports with an end-side bone.

[0020] The applicant's patent EP 3 431 668 B1 discloses general prior art applicable within the scope of the invention for the design of a partial fairing for the front loader to cover moving components, in particular a control rod.

[0021] The applicant's patent application EP 4 144 925 A1 discloses further possibilities for the design of an attachment bracket in the form of an attachment tower that can be used within the scope of the invention, wherein the attachment tower is at least partially manufactured by means of solid forming. TASK OF INVENTION

[0022] The present invention is based on the objective of proposing an attachment and a vehicle combination formed with a work vehicle and an attachment, which with regard to - the control and / or - the coordination of the operation of the work vehicle and the attachment and / or - in order to enable an expanded range of functions The invention is improved. Furthermore, the invention aims to propose a computer program product for a correspondingly improved vehicle combination.

[0023] The invention also aims to propose a new use for a control unit of an attachment or vehicle combination. SOLUTION

[0024] The object of the invention is achieved according to the invention by the features of the independent claims. Further preferred embodiments of the invention can be found in the dependent claims. DESCRIPTION OF THE INVENTION

[0025] An attachment according to the invention, in particular a front loader, has a hydraulic system with two, three, or more hydraulic actuators. The hydraulic actuators are, in particular, a single- or double-acting lifting cylinder, by means of which a boom of the attachment can be raised and lowered, and / or a single- or double-acting tilting cylinder, by means of which a tool holder can be pivoted relative to the boom. It is entirely possible within the scope of the invention that the hydraulic system has further hydraulic actuators to enable an extended range of functions. For example, the attachment or the front loader can also have a telescopic boom, wherein the telescoping of the boom is effected by a further actuator in the form of a hydraulic actuating cylinder (cf. the unpublished European patent application EP 23185 356).5, which is the subject of the present disclosure with regard to the control and design of a telescopic boom). The hydraulic actuator may also be a positioning cylinder, hydraulic drive, or hydraulic motor that is part of the attachment or a tool held thereon. It is also possible that a hydraulic actuator is a positioning cylinder of a support leg of a front loader according to DE 10 2005 053 041 A1.

[0026] The invention is based on the understanding that, for conventional vehicle combinations, the interface between the work vehicle and the implement consists exclusively of a hydraulic interface. This interface transmits hydraulic control pressure for a lifting cylinder and a hydraulic control pressure for a tilting cylinder, which are controlled by a valve assembly in the work vehicle, to the implement. The implement is thus a kind of "passive system" whose operating state is determined by the work vehicle without any electronic influence from the implement.

[0027] According to the invention, it is proposed that the attachment has an attachment bus system. The attachment bus system has an attachment bus interface. The attachment bus system can be connected to a work vehicle bus system via the attachment bus interface. For this purpose, the attachment bus interface can be designed as at least a plug or a combined plug strip. It is also possible that the attachment bus interface is designed for a suitable connection for automatic coupling of the attachment to the work vehicle. Furthermore, it is possible that the attachment bus interface is integrated into a comprehensive interface serving other functions, which may also include hydraulic connections.

[0028] In one embodiment of the invention, the attachment has pressure sensors that detect pressures in the hydraulic system. For example, pressure sensors can detect the pressure in one pressure chamber of a hydraulic actuator, or preferably in both pressure chambers of the hydraulic actuator (directly or indirectly), which preferably applies to the lifting cylinder and / or the tilting cylinder. According to the invention, the pressure sensors are then coupled (directly or via a control unit of the attachment) to the attachment bus system in such a way that the measurement signals of the pressure sensors (or signals calculated by the control unit) can be transmitted via the attachment bus system. Furthermore, the measurement signals of the pressure sensors or the calculated signals can also be transmitted to the work vehicle bus system via the attachment bus interface and a work vehicle bus interface.

[0029] For an alternative or cumulative embodiment of the invention, the attachment is equipped with motion sensors. These motion sensors detect a displacement or angle of movement of the attachment, which describes an operating state of the attachment. For example, a motion sensor can detect the displacement of a hydraulic actuator, in particular the lifting cylinder and / or the tilting cylinder. It is also possible for a motion sensor to detect the rotation angle of a joint of the attachment, for example, the rotation angle of the tool holder relative to the boom and / or the rotation angle of the boom relative to the column. The motion sensors are then coupled (directly or via a control unit of the attachment) to the attachment bus system in such a way that the measurement signals of the motion sensors (or signals calculated by the control unit using these signals) are transmitted via the attachment bus system (and possibly also via the control unit).(also via the implement bus interface, the work vehicle bus interface to the work vehicle bus system).

[0030] Within the scope of the invention, the connection between the implement bus interface and the work vehicle bus interface can be used unidirectionally for transmitting signals between the work vehicle and the implement, or unidirectionally for transmitting signals between the implement and the work vehicle. Preferably, data is transmitted bidirectionally between the work vehicle and the implement.

[0031] The measurement signals acquired by means of the pressure sensors and / or motion sensors can (directly or after conversion by a control unit of the attachment) be made available to a control unit of the work vehicle within the scope of the invention and used there to appropriately adapt the operating state of the work vehicle and the assemblies of the work vehicle according to an operating state of the attachment and / or be displayed to a user on a display device in the driver's cab.

[0032] In a further embodiment of the invention, the attachment features an electronically controlled valve assembly. The attachment also has at least one hydraulic supply connection. This hydraulic supply connection is connected to a supply line of the work vehicle to provide pressurized hydraulic fluid. The supply line is pressurized with hydraulic fluid by a pump in the work vehicle.

[0033] Preferably, the attachment has at least one hydraulic supply connection that can be connected to the work vehicle, while no hydraulic control connections exist between the work vehicle and the attachment. Instead, in this case, control signals are transmitted exclusively electrically or electronically, preferably via the attachment's bus interface. A supply connection or line can be a connection or line through which hydraulic fluid is transferred from the work vehicle to the attachment, or a connection or line through which hydraulic fluid is returned from the attachment to the work vehicle.

[0034] Within the scope of the invention, the operation of the pump of the work vehicle can also be controlled as required by means of the measurement signals from the pressure sensors and / or motion sensors transmitted to the work vehicle or the signals calculated therefrom, and / or valve elements in the area of ​​the hydraulic supply system of the work vehicle can be controlled depending on these measurement signals.

[0035] In the embodiment according to the invention, the valve device is responsible for controlling or regulating the hydraulic actuation of the hydraulic actuators depending on information obtained via the attachment data bus.

[0036] This will be explained using a simple example that does not limit the invention: If the operator in the cab of the work vehicle issues a manual signal to raise or lower the attachment (for example, using a joystick), this signal can be transmitted via the work vehicle bus system, the work vehicle bus interface, and the attachment bus interface to the attachment bus system. The valve system is then controlled according to this signal. In this case, the control pressures are not generated on the work vehicle, but directly at the attachment. It is even possible that, based on the measurement signals from the pressure sensors and / or motion sensors, not only are the hydraulic control pressures controlled, but also, by feeding back the actual signals, the hydraulic supply to the hydraulic actuators is regulated.

[0037] In a particular embodiment of the attachment according to the invention, the attachment features a stroke sensor that detects the stroke of a lifting cylinder of the attachment. The stroke sensor can be arranged outside the lifting cylinder and detect the relative position between components that move when the boom is raised and lowered. Alternatively, the stroke sensor can be integrated into the lifting cylinder itself and, for example, detect the relative movement of the piston of the lifting cylinder with respect to the cylinder housing of the lifting cylinder.

[0038] Alternatively or cumulatively, it is possible that the attachment has a tipping distance sensor that detects the tipping distance of a tipping cylinder of the attachment.

[0039] Regarding the integration of the tilting distance sensor into the attachment, what was said previously about the lifting distance sensor applies accordingly.

[0040] Alternatively or cumulatively, the attachment may have a pressure sensor that detects the pressure acting on a pressure chamber of a lifting cylinder, a tilting cylinder, or another hydraulic actuator. Preferably, however, the attachment has a pair of pressure sensors that detect the pressures acting on opposing pressure chambers of a double-acting lifting cylinder, a tilting cylinder, or any other actuating cylinder. Within the scope of the invention, the attachment may also have an angle sensor that detects a pivot angle of the attachment's rocker arm relative to the attachment's column, and / or an angle sensor that detects a pivot angle of a tool holder of the attachment relative to the attachment's rocker arm.Within the scope of the invention, the signals from the aforementioned sensors are then transmitted (directly or after conversion by a control unit of the attachment) via the attachment bus system.

[0041] In a further aspect of the invention, the implement bus system also includes a tool bus interface. The implement bus system can be connected to a tool bus system via this interface. This allows for the creation of a comprehensive bus system through which the work vehicle bus system, the implement bus system, and the tool bus system can communicate with each other (unidirectionally or bidirectionally). This configuration is particularly advantageous when the tool has a hydraulic actuator. In this case, a sensor on the tool, especially a motion sensor or a pressure sensor, can detect the tool's operating position, and this operating state can then be transmitted via the measurement signal (either directly or after conversion by a control unit of the front loader) to the implement bus system and / or the work vehicle bus system. For example, the work vehicle can then...The operating position of the tool can be displayed to the user on a screen, or the operating position can be used to control other actuators or components of the work vehicle or attachment. It is also possible for control signals to be transmitted from the work vehicle via the attachment or from the attachment to the tool bus system, which are then used by a control unit of the tool to control or regulate the operating position of the tool's actuator.

[0042] It is possible that the attachment only has the attachment bus system, which can then be directly coupled to any sensors and / or to any control unit for the valve assembly or components. According to one embodiment of the invention, the attachment has, in addition to the attachment bus system, which, as explained, is coupled to the work vehicle bus system and / or the tool bus system, a further attachment bus system, which preferably does not communicate directly with the work vehicle and the tool. A control unit is then arranged between the attachment bus system and the further attachment bus system, via which the two aforementioned bus systems are connected. It is possible, for example, that the attachment bus system is designed as an ISOBUS, while the further attachment bus system is designed as a CAN bus system.The additional implement bus system then serves to connect to the sensors and / or the valve assembly and any other components. According to this design, the two different bus systems can be specifically adapted to the respective requirements. For example, the additional implement bus system can enable faster data transmission and thus faster control of the valve assembly and actuators. This can be achieved either through a faster data transmission rate of the additional implement bus system and / or by reducing the amount of data exchanged via this additional implement bus system. To give just one example that does not limit the invention, the implement bus system can also transmit image signals, while this is not possible for the additional implement bus system.

[0043] Another solution to the problem underlying the invention is a vehicle combination comprising a work vehicle, in particular a tractor, and an implement attached to the work vehicle, in particular a front loader. The work vehicle then has a work vehicle bus system. The work vehicle bus system has a control device, which can be, for example, a joystick or a touchscreen. Furthermore, the work vehicle bus system can have a display device, such as a monitor, which, if configured as a touchscreen, can also simultaneously provide a control unit.

[0044] In this case, the work vehicle bus system has the previously mentioned work vehicle bus interface. The attachment of the vehicle combination can then be configured as described above. The work vehicle bus system and the attachment bus system are then coupled to each other via a connection between the work vehicle bus interface and the attachment bus interface. It is also possible that the vehicle combination additionally has a tool bus system, in which case the attachment bus system is additionally coupled to the tool bus system via suitable interfaces.

[0045] The interfaces can also be connected for electrical power supply. For example, a power supply interface in the form of a three-pin socket may be provided.

[0046] The implement bus interface and the work vehicle bus interface can, for example, be designed as ISOBUS sockets. To give just one example that does not limit the invention, the ISOBUS socket can be designed as a four-pin Deutsch connector.

[0047] Finally, it is also possible that coupling is achieved via hydraulic connections, especially for a hydraulic supply.

[0048] In a particular aspect of the invention, the work vehicle has an ISOBUS socket at the rear, which is intended for connection to a rear-mounted implement that may be driven by a power take-off shaft. In this case, a cable connection of the work vehicle's ISOBUS bus system can run from the rear to the front of the work vehicle, where coupling with the implement's ISOBUS bus system then takes place via suitable interfaces.For this embodiment, a branch connector or junction box can be installed in the ISOBUS socket already present at the rear. This junction box allows for a branch to one ISOBUS line connected to the implement at the rear, and another ISOBUS line running along the work vehicle from the rear to the front, enabling connection to the work vehicle's bus system at the front. For example, the latter ISOBUS line could run longitudinally underneath the work vehicle from the rear to the front. In this configuration, the ISOBUS line could be integrated into a connecting or wiring harness with other lines, cables, hydraulic lines, etc.

[0049] According to one aspect of the invention, the work vehicle and / or the attachment has a control unit with control logic. This control unit with the control logic then coordinates the operation of the work vehicle and the operation of the attachment via the attachment bus interface. Where a control unit or control logic is mentioned below, this can refer to the case where the control unit with the control logic (and an associated valve assembly for controlling the control pressures for the lifting cylinder and / or the tilting cylinder and any other actuators) can be arranged in the area of ​​the work vehicle and / or in the area of ​​the attachment, without this needing to be explicitly stated in each case.

[0050] However, it is also possible that a control unit with control logic is arranged on both the work vehicle and the attachment, whereby the control units and control logics can then communicate with each other to ensure the functionalities explained below.

[0051] According to the invention, the following extended functional scopes can preferably be provided on an attachment and / or a vehicle combination: a) It is possible that pressure control is implemented based on the pressure signals in the lifting cylinder and / or tilting cylinder and / or any other hydraulic actuator of the attachment or tool. This allows the control logic and control unit to regulate the operating positions of the valve assembly to generate the control pressures for the lifting cylinder, tilting cylinder, or any other hydraulic actuator, thereby achieving increased precision. It is also possible that the pressure control includes a pressure limiter to reliably prevent excessively high pressures that could lead to damage. The following are some possible examples of pressure control that do not limit the invention: It is possible, for example, that a tool is designed as a bale grabber, which is hydraulically actuated by a cylinder or motor of the tool. For comfortable and safe operation, a limit to the clamping force of the bale grabber is necessary, which can be achieved based on pressure regulation. If it is possible that different tools with hydraulic actuators requiring different maximum operating pressures are attached to the implement, the control logic can, based on manually entered or automatically detected information about which tool is currently coupled to the implement, impose a tool-specific pressure limit. It is also possible to ensure a pressure relief function, which is particularly relevant when a hydraulic motor is operated on a tool. This pressure relief prevents overloading of the motor and the tool, which can occur, for example, due to jamming or other blockage of the hydraulic motor. If the pressure exceeds a predefined threshold, the valve is activated to prevent further pressure increases or to reduce the pressure. Simultaneously, information can be transmitted via the bus system to the work vehicle and the user via a monitor or other display device indicating that an overload or malfunction, especially a blockage of the hydraulic motor, has occurred. b) Another possible function within the scope of the invention is that the control logic automatically determines the load carried by the attachment. Alternatively or cumulatively, a coordinate of the center of gravity of a load carried by the attachment can be determined. For example, the load is the mass of the tool held on the attachment and / or the mass of an object or material supported on the tool, in particular a material in a bucket or an object on a pallet. Within the scope of the invention, the load and / or center of gravity can be determined based on the measurement signals from the pressure sensors. The actuating force of a lifting cylinder or tilting cylinder can be calculated from the resulting force exerted hydraulically on the cylinder's piston, which in turn depends on the pressures in the two pressure chambers of the actuating cylinder. If the resulting force is known (for static or dynamic operation), for example in a lifting cylinder, the control logic converts this resulting force into the load via the specific kinematics of the attachment and / or tool.Consideration of the specific kinematics of the attachment is necessary because, for example, the same load on a bucket held by a front loader will result in different required forces in the area of ​​the lifting cylinder for different boom lengths. Furthermore, the load calculation also takes into account the signals from the motion sensors, since, for example, the support force of the lifting cylinder required to hold a load at a predetermined height may depend on the operating position of the attachment, such as the boom's swivel angle relative to the column. The same applies to determining the coordinate of the load's center of gravity. If the control logic is to determine both the load and the coordinates of the center of gravity, two unknown quantities must be determined from a mathematical perspective. Determining these two unknowns requires sufficient measurement signals, namely the pressure signals from the pressure sensors and the motion sensors. Within the scope of the invention, after determining the load and / or the coordinates of the load's center of gravity, these can be taken into account for controlling the operating positions of the attachment or the vehicle combination. For example, the load and the coordinates of the center of gravity can be used to determine when a critical operating condition of the vehicle combination is reached, which can result in reduced stability and the risk of tipping over. Based on a determined load and / or center of gravity, the operating speeds of the actuator cylinders and / or the stroke of the actuator cylinders can also be limited. Preferably, the control logic stores the type of attachment, its kinematics and dimensions, or related characteristic parameters, on the one hand, and the kinematic parameters or characteristic parameters of the tool on the other. It is possible to perform a one-time calibration of an attachment and / or tool by determining the respective parameters, in particular the load and at least one coordinate of the center of gravity, during a test run, and then storing this data. If a specific tool and / or attachment is then used in the vehicle combination, this is automatically detected or manually selected by the user, and the determined parameters are then read and used for subsequent operation with the attachment or tool. Preferably, the load and / or the coordinate of a center of gravity is determined within a specified partial positioning range of the positioning range of the lifting cylinder and / or tilting cylinder. It is also possible that (especially to determine the coordinate of a center of gravity) two different partial positioning ranges or specific different positioning positions of at least one positioning cylinder, in particular the lifting cylinder, are approached. It is possible that the result of the load determination and / or a coordinate of the center of gravity is displayed on a display device of the work vehicle. If multiple weighing processes take place, the control logic can be appropriately designed to add up the multiple determined loads to a total weight. Preferably, a load and / or the coordinates of a center of gravity are determined while the vehicle combination is parked. However, within the scope of the invention, it is also possible for the load and / or the coordinates of the center of gravity to be determined while the vehicle combination is in motion, preferably only below a certain speed threshold. c) A further aspect of the invention is based on the understanding that the force distribution on a lifting cylinder of an attachment depends on the size of the load. If the lifting cylinder is controlled by providing a control pressure, then different loads carried by the attachment result in different lifting speeds of the lifting cylinder for the same control pressure. Here, a lifting speed can be either a positive speed, which leads to an increase in height or lifting, or a negative lifting speed, which decreases the height, thus resulting in lowering. Preferably, the lowering of the boom is controlled or regulated in such a way that, when the same lowering command is given by the driver or by a control unit, e.g., with the same deflection of a joystick controlling the lowering, the same lowering speed of the boom around the joint is achieved, or the same lowering speed of the tool in the vertical direction is achieved, regardless of the load. Known designs of attachments or front loaders can, for example, lead to a situation where, with a heavy load and the driver's command to lower the lifting cylinder, the lowering occurs at too high a speed, which in the worst case makes sensitive control by the user impossible and can lead to damage. According to the invention, the lifting speed of the lifting cylinder and / or the tilting speed of the tilting cylinder can be controlled or regulated depending on the load, taking into account the measurement signals of the pressure sensors and / or the measurement signals of the motion sensors. Such control or regulation can consist of specifying the hydraulic control pressures acting on the lifting cylinder and its pressure chambers. It is also possible that an adjustable throttle is arranged in a pressure chamber which must be emptied to lower the lifting cylinder, the throttle position of which then depends on the load. Within the scope of the invention, it is also possible that the control or regulation of the lifting speed and / or tilting speed is carried out taking into account the position of a control element, in particular a joystick, so that a greater lifting speed or tilting speed is controlled for a stronger actuation or deflection of the control element or joystick than for a smaller actuation or deflection. In one aspect of the invention, the control logic ensures that the lifting speed is the same in both directions, so that the same application of pressure to the control element or deflection of the joystick in different directions results in the same actuating speed of the lifting cylinder in both directions for raising and lowering. However, it is also possible that the controlled or regulated speed is not the speed of the actuator cylinder, but a speed of the attachment or tool at a significant position, which may require that different actuator cylinder speeds be achieved depending on the operating position of the attachment and / or tool and thus depending on the current kinematic conditions. d) Within the scope of the invention, it is possible that when a specific operating state of the attachment and / or the tool is brought about, this specific operating state is stored, in particular by storing the pressures with which the pressure chambers of the lifting cylinder and the tilting cylinder and any further actuator are actuated, and / or the measurement signals of the motion sensors in the specific operating state. If such an operating state is then to be restored to a later state, this can be done automatically by the control logic automatically acting on the hydraulic actuators in such a way that this stored operating state is restored.This automatic restoration of the saved operating state can be triggered manually by the driver, for example via a button, a touchscreen or a joystick, or it can be triggered automatically depending on any operating state of the vehicle combination or on the detection of a specific geodetic position of the vehicle combination via a GPS system or the reaching of a position range. Preferably, saving and / or restoring is possible in two different modes: - For one mode, only the storage and restoration of an operating position of an actuator cylinder, in particular the lifting cylinder or tilting cylinder, takes place. - However, for another operating mode, the combined storage and restoration of both an operating position of the lifting cylinder and an operating position of the tilting cylinder is possible. Alternatively or in addition to storing only specific operating positions, it is also possible to store and restore an entire operating state history. To give just one example that does not limit the invention, such a stored operating state history can include an initial position in which a front loader is lowered and a bucket attached to the front loader rests flat on the ground. In this initial position, the bucket can be filled into a pile of material by moving the vehicle combination forward. Subsequently, the bucket is raised by actuating the lifting cylinder, while at the same time the bucket is tilted backward by actuating the tilting cylinder to secure the contents of the bucket during the lifting movement and any subsequent driving movement. A final position is reached when the boom with the implement is at a predetermined working height.The stored operating state history thus includes the operating parameters and profiles between the initial and final positions. If the same operating state history is required at a later time, the driver does not need to initiate it by specifically controlling the lifting and tilting cylinders. Instead, the control logic can automatically restore the operating state history. The restoration of the operating state history can be triggered by pressing a button or by a specific movement of the joystick. In this case, too, different modes are possible, whereby in one mode only an operating state profile for the lifting cylinder and / or the tilting cylinder can be brought about, while in another mode a restoration of operating state profiles of both the lifting cylinder and the tilting cylinder takes place simultaneously. e) It is possible that the control logic can be used to create an automatic oscillating movement of a tool holder on the attachment. This is advantageous, for example, if a bucket on a front loader is not completely emptied automatically when tipped, but material still adheres to the inner surfaces of the bucket, which is then to be "shaked off" as a result of the oscillating movement. For example, such an automatic oscillating movement could be triggered by a switch, joystick, or similar device. The control logic would then hydraulically actuate the tilting cylinder to produce an oscillating tilting motion. The amplitude of the oscillation could be predetermined by a switch or the degree of joystick actuation. It's possible for the oscillation amplitude to remain constant for a predetermined period or for the duration of an actuation. Alternatively, the oscillation amplitude could decay and decrease over time. The invention offers numerous possibilities for generating the oscillating movement of the tool holder. For example, the valve assembly can be used to alternately and counter-clockwise apply higher and lower pressures to the pressure chambers of the tilting cylinder. Such altered hydraulic pressures to the pressure chambers can be achieved by alternating connections to a pressure source and a pressure sink via the valve assembly. It is also possible to shut off the hydraulic system entirely, but to use an electric drive to limit the hydraulic system or to move a piston in an oscillating motion back and forth.It is also possible that the hydraulic system connected to the tilting cylinder is linked to a hydraulic oscillator, which generates hydraulic oscillations. An initial deflection of the oscillator can be caused by a pressure surge when a pressure chamber of the tilting cylinder is pressurized. It is possible that the oscillating movement of the tool holder is achieved solely by means of the tilting cylinder. It is also possible that the movement is further supported by an oscillating movement of the lifting cylinder. Alternatively or cumulatively, it is also possible that the engine of the work vehicle is driven in such a way that the work vehicle (and thus the front loader with the tool holder) performs an oscillating forward-reverse movement.An oscillating movement of the tool holder can also be used, for example, to shake material arranged in a shovel in such a way that it is compacted. It is possible that the driver sets the frequency of the oscillating movement, or that different specific frequencies can be selected. It is also possible that the frequency of the oscillating movement depends on the load. f) The control logic can ensure automatic vibration damping of the attachment. Vibrations of the attachment can occur, for example, when there is a change in the pressure applied to the actuator cylinders, such as rapid actuation or deceleration of an actuator cylinder. In this case, the resulting dynamic oscillations of the attachment can be dampened by, for example, increasing the throttling effect of restrictors in the supply lines to the pressure chambers of the actuator cylinders, or by actively counteracting this by selectively pressurizing the pressure chambers to reduce the resulting vibration. g) A potential problem arises when several actuator cylinders on the attachment, in particular the lifting cylinder, the tilting cylinder, and at least one other hydraulic actuator of the attachment and / or tool, must be operated in parallel. In this case, the hydraulic fluid may be prioritized for the consumer where the pressure is lowest, potentially leading to an insufficient supply to the other consumers, which could result in them not operating at all or not operating sufficiently. In one aspect of the invention, the control logic, by appropriately controlling the valve assembly, automatically controls and / or regulates the distribution of the hydraulic fluid supply flow, which is transmitted from the work vehicle to the attachment, to the consumers, in particular the lifting cylinder, the tilting cylinder, and / or at least one other hydraulic actuator. This distribution can be achieved, on the one hand, so that despite differing pressures of the individual consumers, the consumers are operated to the required extent. On the other hand, it is also possible for the control logic to distribute the supply flow based on a prioritization mechanism, such that a higher-priority consumer is provided with the entire supply flow or a minimum portion thereof (at least for a certain period of time). Within the scope of the invention, the control logic can also influence the operation of the pump of the work vehicle to control the supply, in particular by controlling the speed of the pump and / or a stroke of the pump. h) Within the scope of the invention, the control logic can also ensure parallel guidance of a tool holder. This design is based on the fact that for specific operating processes, for example, lifting a pallet on a tool designed as a pallet fork, it is important that the orientation of the tool relative to the ground does not change during lifting or lowering. However, the pivoting of the rocker arm by actuating the lifting cylinder for lifting and lowering leads to a change in the angle of the tool holder relative to the ground due to the circular movement of the rocker arm around its pivot point. In this case, the control logic can, in parallel with the actuation of the lifting cylinder, also control the tilting cylinder in such a way that the pivoting of the tool holder resulting from the actuation of the lifting cylinder is counteracted by the actuation of the tilting cylinder, thus preventing any change in the orientation of the tool.For this purpose, the control logic can take into account a previously learned, read-in or user-selected attachment type and / or tool type to determine the automatic control of the lifting cylinder and tilting cylinder to ensure parallel guidance of the tool holder. i) It is possible that the control logic limits the stroke of the lifting cylinder, the tilting cylinder, and / or any other actuating cylinder by specifying a minimum and / or maximum stroke of the actuating cylinder. It is possible that this limit defines a kind of "working window" for the actuating cylinder and thus for the attachment or tool. To give just one example that does not limit the invention, an upper limit on the stroke of the lifting cylinder can be implemented such that the vehicle combination can be operated in a building with a reduced ceiling height, whereby the maximum limit on the stroke of the lifting cylinder is selected to prevent a collision between the attachment and the tool held on it with the ceiling of the building. j) A potential problem is that the travel of an actuator cylinder is limited by a stop. If the actuator cylinder, and thus the attachment, reaches the stop, the resulting impact forces and oscillations caused by the stop can lead to reduced comfort, compromise the load held by the attachment, and cause damage. According to one proposal of the invention, the control logic ensures damping in the area of ​​an end position of a stroke of the lifting cylinder and / or a stroke of the tilting cylinder in order to at least reduce such impairments. This damping can, for example, be achieved by using motion sensors to detect when the actuator cylinder is at a predetermined distance from its end position. If this occurs and the actuator cylinder continues to approach the end position, the control logic can then actuate the valve assembly in such a way that a lower actuating speed is achieved, which can then lead to reduced stop forces. It is also possible that the speed is gradually reduced (in steps or continuously) as the actuator approaches the end position. In a particular aspect of the invention, damping is achieved by taking into account the kinetic energy of the attachment and, if necessary, also the load held by the attachment, such that the damping is increased at higher kinetic energy levels. Besides influencing the hydraulic pressures acting on the pressure chambers of the actuator cylinders, damping can also be achieved by means of an adjustable throttle. In this case, the damping set by the control logic can increase as the end position is approached or depend on the calculated kinetic energy of the attachment, possibly including the tool and the held load. It is also possible that the distance from the end position of the travel path, for which an increase in damping takes effect, depends on a calculated kinetic energy of the attachment, possibly including the tool and the load held on it. k) Another aspect of the invention addresses the operation of the vehicle combination in which the attachment, with its mounted tool and possibly a load, is moved over an uneven road surface. If the operating position of the attachment and the tool remains unchanged in this case, the attachment, the tool, and the load follow the unevenness of the road surface, which can result in considerable dynamic forces. The invention proposes that the control logic reduces and regulates the movement of the tool mount when driving on an uneven road surface. Damping of the vibrations that occur can be achieved by appropriately controlling the pressure chambers of the actuator cylinders and / or increasing the damping for pressurizing the pressure chambers by means of an adjustable throttle device.It is also possible to control the actuator cylinders in such a way that, regardless of road surface irregularities, the control objective is to ensure that the tool holder always has the same absolute height and / or the same orientation. In this case, the valve assembly is controlled to regulate the control pressures of the lifting cylinder and the tilting cylinder, taking into account a height sensor, motion sensors, and / or the measurement signals from the pressure sensors. Alternatively or cumulatively, within the scope of the invention, the control logic can also control a leveling device of the work vehicle in such a way that movement of the work vehicle's chassis when driving on uneven road surfaces is at least reduced, thereby also reducing oscillations of the column and thus of the attachment and tool held on the column. In this case, for example, the chassis of the work vehicle can have air suspension or the chassis of the work vehicle can be supported at the vehicle wheels by adjustable springs and / or dampers. In one aspect of the invention, the damping of tool holder movements is achieved by connecting at least one pressure chamber of an actuating cylinder to a hydraulic accumulator via a valve. Preferably, a hydraulic volume in the accumulator is supported against a pneumatic volume by a movable wall or diaphragm. To achieve damping, the connection between the pressure chamber and the accumulator can be selectively controlled via the valve. Alternatively, the valve may have different operating positions in which the connection is made via different throttle cross-sections (in stages or continuously), thus allowing the degree of damping to be influenced by the valve's operating position. l) In a further aspect of the invention, the control logic is suitably designed to ensure the locking and / or unlocking of a locking device that locks the tool to the tool holder of the attachment. According to the invention, for the first time, this control logic is arranged on the attachment itself with a valve device for actuating the locking device between the locked and unlocked positions. In a particular aspect of the invention, locking and / or unlocking of the locking device is only possible in selected operating positions or operating position ranges, for which the control logic can use the measurement signals from the motion sensors. For example, unlocking of the tool can only be enabled by the control logic when the attachment is lowered. (m) Within the scope of the invention, the multifunctional communication between the work vehicle and the attachment can also be used to activate and / or deactivate a drive system, in particular an all-wheel drive system, of the work vehicle depending on an operating state of the attachment. For example, the all-wheel drive of the work vehicle can be activated depending on the lifting height of the attachment's boom in order to increase the stability of the work vehicle on the ground at a specific lifting height. It is also possible that the all-wheel drive is only activated when the lifting height of the boom falls below a threshold value, thus enabling a bucket attached to the boom to be driven into a pile of material on the ground in all-wheel drive mode.Above the lifting height specified by the threshold, the work vehicle can then move without all-wheel drive, which can lead to a reduction in wear on the vehicle wheels, a reduction in the load and tension on the work vehicle, an increase in steering flexibility and possibly also a smaller turning radius. n) If the load is known, either through the previously described automatic determination of the load carried by the attachment or through manual load input by the user, the control logic can also specify a maximum travel speed for the work vehicle, which depends on the load. This contributes to the operational safety of the work vehicle during travel. o) It is also possible that the control logic establishes a predetermined relationship between the angle of the tool holder and the travel of the actuating cylinders. This predetermined relationship could, for example, involve a guide such that the control of the lifting and tilting cylinders is such that the angle of the tool holder follows a predetermined path during lifting or lowering. For example, the path could be such that, regardless of the actuation of the actuating cylinders, the tool holder always maintains the same angle relative to the ground, thus ensuring parallel guidance. It is also possible that the tool, particularly a bucket, is automatically tilted during lifting and lowering. p) It is also possible that a so-called speed scaling function is provided via the control logic. This means that the control unit, the control logic, and the valve assembly of the attachment can use different conversion characteristics to convert a signal, for example, one specified by the driver via the joystick and transmitted via the attachment bus interface, into a control signal for the lifting cylinder and / or the tilting cylinder. The different conversion characteristics can then be automatically selected by the control unit depending on the operating situation, or the driver can select one conversion characteristic from several available conversion characteristics.For example, a first conversion characteristic might involve a linear dependence of the joystick deflection on the control signal for the valve assembly, on the opening position of a valve, or on pressure adjustment by the valve assembly, while a second conversion characteristic might involve a different linear dependence with a different gain factor, or even a non-linear dependence. Any curved relationship, with or without a jump and / or kink, can be used as a non-linear dependence. To give just one example that does not limit the invention, a small gain factor could be used for a small joystick deflection, while a larger gain factor could be used for a larger joystick deflection.This can be used to advantage by allowing the driver to make sensitive adjustments to the small joystick movements, while for larger movements the cylinder and / or tilt cylinder can be controlled at a higher speed to enable coarse but fast control. q) It is possible that the control logic can provide a so-called speed mode in which the valves and the lifting cylinder and / or the tilting cylinder are controlled to achieve increased or maximum speeds. This may also include increasing or maximizing the amplification factor of a control signal applied via a joystick. r) For one proposal, the control logic ensures a so-called float function. With a float function, opposing pressure chambers of the actuator cylinder, particularly the lift cylinder and / or the tilt cylinder, are short-circuited via the attachment's valve assembly or connected to each other via a throttle in the attachment's valve assembly. This allows the actuator cylinder to be adjusted when external forces are applied to the attachment. For example, if a bucket attached to the implement mount of a front loader is resting on the ground, the float function allows the bucket to perform a compensating movement when driving on uneven ground, thus reducing potential damage to the ground or forces acting on the implement and the front loader. s) Through the interaction and signal exchange between the work vehicle and the attachment via the bus system and bus interfaces, the operation of the work vehicle's pump for providing hydraulic pressure can be coordinated with the respective operating state of the attachment. In particular, it is possible to control the work vehicle's pump depending on the load carried by the attachment. For example, if the attachment's control unit detects that the attachment is carrying a heavy load (especially a load greater than a predefined threshold), the pump can be controlled in such a way that an increased flow rate of hydraulic fluid is provided by increasing the stroke.It is also possible, however, that in this case the speed of the pump of the work vehicle is increased. In one embodiment of the invention, this can be achieved by increasing the speed of the engine of the work vehicle that drives the pump, or by adjusting a gearbox through which the engine of the work vehicle is coupled to the pump. It is also possible to reduce the stroke of the pump in order to provide higher pressures, which can then be applied to the actuator cylinders to enable the positioning movements despite the increased load. Another possibility is that the pump control is continuously varied depending on the magnitude of the load.

[0052] Preferably, the implement or vehicle combination has a database. This database can store specific characteristics of tools that can be coupled to a tool holder on the implement. These characteristics can be provided and stored at the factory or loaded and stored via a data network or cloud connection. Alternatively, the user can teach these characteristics to the implement during the first use with the tool by moving the implement to specific predefined operating positions or by running a test program that then automatically determines the characteristics. When a specific tool is actually used with the implement, the operator can select the specific characteristics of that tool, or these characteristics can be selected automatically.Alternatively or cumulatively, specific identification data of the attachment can also be stored in the database and retrieved for the attachment used in each case, whereby the provisions mentioned above regarding the identification data of the tools apply accordingly to the provision, training and retrieval of the identification data.

[0053] For automatic identification of a specific attachment and / or tool to be used, the attachment or tool can have an RFID chip containing an identifier for the respective attachment or tool type, which can be read to identify the type. Alternatively, another identifier, particularly a scannable barcode or QR code, can be used, or the tool or attachment can be identified using automatic image recognition of an image captured by a camera. It is also possible for the attachment or tool to have a specific contact contour that can then be scanned to identify the attachment or tool type.

[0054] In a further aspect of the invention, the attachment receives (at least) one control variable via the attachment bus interface. This control variable can be set by the operator using a control device or joystick in the operator's cab of the work vehicle. Alternatively or cumulatively, this control variable can be set automatically by a control unit of the work vehicle depending on the operating state of the work vehicle. The control variable can be, for example, a target stroke of an actuator cylinder, in particular the lifting cylinder and / or the tilting cylinder, or another hydraulic actuator (especially the tool). Preferably, this control variable is independent of which specific attachment and / or which specific tool is mounted on the work vehicle.In this proposed version of the invention, the control unit of the attachment incorporates control logic that adapts the control of the valve assembly to the specific attachment and / or tool. The control logic controls the valve assembly to generate the hydraulic actuation of the lifting cylinder, tilting cylinder, and / or actuator, taking into account the control variable received via the attachment bus interface. Additionally, the control logic considers specific characteristics of the tool currently coupled to the attachment. These characteristics may include, for example, tool geometry, characteristic data of the tool's motor or actuator cylinder, dimensions, and the coordinates of pivot points.Alternatively or cumulatively, the control logic can also consider specific characteristics of the attachment's geometry, such as dimensions, in particular the length of a boom arm, its height or offset, pivot points of the column and mounting bracket, pivot points of the actuator cylinders, pivot points of the tool holder, and similar parameters. Alternatively or cumulatively, the control logic can also consider specific characteristics of the lifting cylinder, tilting cylinder, and / or other hydraulic actuators. For example, different actuator cylinders may be used for different types of attachments, achieving the same stroke for different flow rates and / or pressures in the pressure chambers.This embodiment according to the invention thus enables the work vehicle to transmit control signals that are independent of the specific attachment and / or tool used, while the specific adaptation to the attachment and tool is then carried out by the control logic of the attachment's control unit. It is possible for the aforementioned characteristic data to be stored in the attachment's database as described above.

[0055] According to a further aspect of the invention, the attachment has an interface through which operating data of the attachment can be transmitted. This interface can be wired or wireless, with a wireless interface being designed as a WLAN interface, Bluetooth interface, or similar. The operating data can be transmitted via the interface to a central computer of the user, the operator of a fleet of work vehicles, a company where the work is carried out, or to a data cloud. To give just one example, which does not limit the invention, a load automatically determined by the attachment can be transmitted via the interface, and the mass of the transported load can then be documented and stored for documentation purposes.

[0056] Another solution to the problem underlying the invention is a computer program product. This computer program product is suitable for operation on a control unit of the work vehicle or the attachment. The work vehicle is equipped for the attachment of an attachment, as previously described. The computer program product has control logic that enables an operator to control the attachment using a control unit of the work vehicle via control commands. These control commands for controlling hydraulic actuators of the attachment are transmitted to an attachment bus system via a work vehicle bus system, a work vehicle bus interface, and an attachment bus interface.

[0057] Preferably, the computer program product has control logic that enables functions, operating states or measurement signals from pressure sensors or motion sensors of the attachment or a tool held thereon to be displayed to an operator on a display device of the work vehicle.

[0058] Advantageous further developments of the invention result from the claims, the description and the drawings.

[0059] The advantages of features and combinations of features mentioned in the description are merely exemplary and can have an effect alternatively or cumulatively, without the advantages necessarily having to be achieved by embodiments according to the invention.

[0060] Regarding the disclosure content—not the scope of protection—of the original application documents and the utility model, the following applies: Further features can be seen in the drawings—in particular, the geometries shown and the relative dimensions of several components to one another, as well as their relative arrangement and functional connection. The combination of features from different embodiments of the invention or from features of different claims is also possible, deviating from the chosen cross-references of the claims, and is hereby encouraged. This also applies to features that are shown in separate drawings or mentioned in their description. These features can also be combined with features from different claims.Likewise, features listed in the claims may be omitted for further embodiments of the invention, but this does not apply to the independent claims of the registered utility model.

[0061] The features mentioned in the claims and the description are to be understood as meaning that exactly that number, or a greater number than stated, is present, without the need for the explicit use of the adverb "at least". Thus, for example, if one element is mentioned, this is to be understood as meaning that exactly one element, two elements, or more elements are present. The features listed in the claims may be supplemented by further features or may be the only features that the subject matter of the respective claim possesses.

[0062] The reference marks included in the claims do not constitute a limitation of the scope of the subject matter protected by the claims. They merely serve the purpose of making the claims easier to understand. BRIEF DESCRIPTION OF THE FIGURES

[0063] The invention will now be further explained and described with reference to preferred embodiments shown in the figures. Fig. Figure 1 shows a highly schematic representation of a vehicle combination consisting of a work vehicle, a rear-mounted attachment, a front-mounted attachment and a tool. Fig. Figure 2 shows a spatial view of a detail of an attachment designed as a front loader. FIGURE DESCRIPTION

[0064] Fig. 1. A vehicle combination 1. The vehicle combination 1 includes a work vehicle 66. In the following, reference is made to the design of the work vehicle 66 as a tractor 2, without any restriction in this regard.

[0065] A detachable attachment 3 is mounted on the rear of the tractor 2.

[0066] A detachable implement 67 is attached to the front of the tractor 2 in the area of ​​a mounting bracket. In the following, reference is made to the design of the implement 67 as a front loader 4, the column of which is attached to the mounting bracket, without any limitation in this respect.

[0067] The front loader 4 carries a tool 5 in the end area facing away from the tractor 2, in the area of ​​a tool holder, which can be released and locked in place via a locking device.

[0068] The tractor 2 has a control unit 6, which can be configured as a central control unit or can comprise several interconnected sub-control units. The control unit 6 serves to control the functions of the tractor 2 and, for this purpose, controls the tractor 2's components.

[0069] The tractor 2 has a display device 7, in particular a screen 8, and an operating device 9, in particular a joystick 10, pedals, switches, controls, etc. The display device 7 and the operating device 9 communicate with the control unit 6, whereby operating signals entered via the operating device 9 are transmitted to the control unit 6 and the control unit 6 sends information to the display device 7, which is displayed on the display device 7 in order to make this information known to the driver of the tractor 2.

[0070] The control unit 6 controls assemblies, in particular an engine 11 and a gearbox 12 of the tractor 2, according to the inputs of the operating device 9 and according to automatically determined control commands.

[0071] The tractor 2 has a hydraulic system 13. In the hydraulic system 13, a flow of pressurized hydraulic fluid is provided by means of a hydraulic pump 14. The operation of the pump 14 is controlled or regulated by the control unit 6, whereby the control unit 6 can activate and deactivate the pump 14, specify the speed of the pump 14 and / or specify any adjustable stroke of the pump 14.

[0072] The tractor 2 has a work vehicle bus system 15, which is preferably designed as an ISOBUS 16. The control unit 6, the display unit 7, the operating unit 9, the engine 11, the transmission 12 and the pump 14 (as well as other components of the tractor 2) are connected to the work vehicle bus system 15 and communicate via the work vehicle bus system 15.

[0073] The attachment 3 has a control unit 17. The control unit 17 controls the function of a hydraulic power unit 18 of the attachment 3. The work vehicle bus system 15 has a work vehicle bus interface 19, which is connected to an attachment bus interface 20 of the attachment bus system 21. The attachment bus system 21, which is preferably also designed as an ISOBUS, communicates with the control unit 17 of the attachment 3.

[0074] The tractor's pump 14 supplies hydraulic fluid in a supply line 22, which is connected via a work vehicle supply interface 23 to an implement supply interface 24 of the implement 3. The implement supply interface 24 is connected via a supply line 25 to the hydraulic power unit 18 for the purpose of supplying it under control by the control unit 17.

[0075] The front loader 4 has a hydraulic system 26 and an implement bus system 27, which is preferably designed as an ISOBUS. A supply line 28 of the hydraulic system 26 is connected via a connection of an implement supply interface 29 to a work vehicle supply interface 30 to a supply line 31 of the tractor 2, which is supplied with hydraulic fluid by the pump 14.

[0076] The implement bus system 27 is connected to the work vehicle bus system 15 for bidirectional communication via the connection of an implement bus interface 32 with a work vehicle bus interface 33.

[0077] The front loader 4 has a control unit 34 which is connected to the implement bus system 27. The front loader 4 has a valve assembly 35. The valve assembly 35 can be designed as a single valve unit with a common housing or as several valve modules flanged together. It is also possible for the valve assembly 35 to be designed with several valve units distributed around the front loader 4, which are connected to each other via hydraulic lines. The valve unit 35 is supplied with hydraulic pressure and hydraulic flow via the hydraulic system 26.

[0078] The front loader 4, in the illustrated embodiment, has a lifting cylinder 36 and a tilting cylinder 37, each designed as a double-acting cylinder. The pressure chambers of the lifting cylinders 36 and 37 are each pressurized with control pressures, which are controlled by the valve assembly 35 under control by the control unit 34, with the aim of effecting the positioning movements of the lifting cylinder 36 and the tilting cylinder 37 or maintaining them in an effected operating position.

[0079] The lifting cylinder 36 has pressure sensors 38, 39, each assigned to a pressure chamber of the lifting cylinder 36. Furthermore, the lifting cylinder 36 has a motion sensor 40, which detects the stroke of the lifting cylinder 36.

[0080] The tilting cylinder 37 has pressure sensors 41, 42, each assigned to a pressure chamber of the tilting cylinder 37. Furthermore, the tilting cylinder 37 has a motion sensor 43, which detects the stroke of the tilting cylinder 37.

[0081] A motion sensor 44 can detect the movement of the boom, in particular a pivot angle of the boom relative to the column of the front loader 4. It is also possible that a motion sensor 45 detects the movement of the tool 5 relative to a tool holder of the front loader 4, which can also be a pivot angle.

[0082] The pressure sensors 38, 39, 41, 42 and the motion sensors 40, 43, 44, 45 communicate with the attachment bus system 27.

[0083] The tool 5 also has a control unit 46. The control unit 46 controls a valve assembly 47 of the tool 5. The valve assembly 47 controls the control pressures for an assembly of the tool 5, in this case, control pressures for pressure chambers of an actuator 48. The actuator 48 has pressure sensors 49, 50 for detecting the pressures in the pressure chambers and a motion sensor 51 for detecting the stroke of the actuator 48.

[0084] The tool 5 has a hydraulic system 52. A supply line 53 of the hydraulic system 52 provides hydraulic fluid for the valve assembly 47. The supply line 53 is connected via a tool supply interface 54 and an implement supply interface 55 to supply the hydraulic system 26 of the front loader 4 (and via this to the hydraulic system 13 and the pump 14 of the tractor 2).

[0085] The tool 5 has a tool bus system 56, which is specifically designed as an ISOBUS. The tool bus system 56 communicates with the pressure sensors 49, 50 and the motion sensor 51. Furthermore, the tool bus system 56 communicates with the control unit 46.

[0086] The tool bus system 56 communicates via the connection of a tool bus interface 57 with an attachment bus interface 58 with the attachment bus system 27 (and via this with the work vehicle bus system 15).

[0087] The lifting cylinder 36, the tilting cylinder 37 and the positioning cylinder 48 form hydraulic actuators 59, the hydraulic actuation of which is controlled within the scope of the invention via the attachment bus system 27.

[0088] Preferably, the front loader 4 according to the invention (in addition to any bus interfaces and electrical connections) has exclusively at least one hydraulic supply connection, but not a further hydraulic connection for transmitting a hydraulic control pressure from the tractor 2 to the front loader 4.

[0089] It is possible that the control unit of the front loader 4 automatically activates and / or deactivates the headlights of the front loader 4, depending on the motion sensors of the front loader 4, particularly depending on the lifting height. The headlights can, for example, illuminate a target area where unloading, such as tipping a bucket, is to take place. A headlight can be mounted on a crossbar in front of the boom, guided by a parallel guide so that the headlight's orientation relative to the ground remains constant. It is possible that the headlight is only activated when a minimum lifting height is reached, thus illuminating the target area and allowing the bucket to be tipped into the illuminated area.

[0090] Fig.Figure 2 shows a detail of a front loader 4 with a tool holder 60, a boom 61 with two parallel boom arms 62, 63, and associated tilting cylinders 37a, 37b. The boom arms 62, 63 are connected to each other at their front ends by a cross member 64. The control unit 34 and the valve assembly 35 are held on the cross member 64, preferably being flanged to each other. The control unit 34 and the valve assembly 35 are covered by a cover 65 (preferably at least upwards and / or downwards). The cover 65 may be hinged or otherwise removable to allow access to the control unit 34 and / or the valve assembly 35.

[0091] Where a tractor 2 is mentioned here, the statements can apply accordingly to any other work vehicle, and a corresponding substitution can be made. Where a front loader 4 is mentioned here, the statements can apply accordingly to any other attachment, in particular a wheel loader bucket, a mower, a plow, etc., and a corresponding substitution can be made. Where the hydraulic actuators of the front loader 4 are referred to as a lift cylinder or a tilt cylinder, the statements can apply accordingly to any other actuating cylinder, any hydraulic actuator, or any hydraulic unit.

[0092] The invention relates to an attachment 67 for a work vehicle 66, with at least two hydraulic actuators 59, wherein the attachment 67 has a hydraulic attachment supply interface 24 which is configured to be connected to a hydraulic system 13 of the work vehicle 66, wherein the attachment 67 further has an attachment bus interface 32 which is configured to be connected to the work vehicle bus system 15 of the work vehicle 66, wherein the attachment supply interface 24 is configured to supply the attachment 67 with hydraulic fluid provided by the work vehicle 66, and wherein the attachment bus interface 32 is configured to transmit electrical or electronic control commands for actuating the at least two hydraulic actuators 59 of the attachment 67.

[0093] The valve assembly 35 has at least two control valves with which hydraulic fluid provided by the work vehicle 66 can be directed to the control and supply of the at least two hydraulic actuators 59, in particular the lifting cylinder 46 and the tilting cylinder 37, in the form of control pressures for the pressure chambers, wherein the at least two control valves are controlled by the control unit 34.

[0094] It is particularly preferred if the valve assembly 35 has exactly two or exactly three control valves for controlling two or three hydraulic actuators of the attachment 67. A valve assembly 35 with three control valves is relatively compact and can therefore be easily accommodated on an attachment 67. At the same time, if such a valve assembly 35 were mounted on the work vehicle 66, prior art embodiments would already require the connection of two or three hydraulic supply lines (each with a supply line and a return line) or two or three pairs of control lines for the three hydraulic actuators.For an embodiment proposed here, the use of a (single) hydraulic supply interface and the electronic bus interface is sufficient, thus reducing the number of connections that need to be made when attaching the implement to the work vehicle.

[0095] In one proposed configuration, the attachment is a wheel loader bucket carrier, and the tool is a bucket. A first control valve in the valve assembly is configured to actuate a hydraulic actuator for raising, lowering, and / or tilting the bucket. A second control valve can be configured to actuate a hydraulic actuator for raising and lowering the wheel loader bucket carrier. A further control valve is preferably available to actuate an additional, undefined / flexibly configurable function of the attachment.

[0096] The valve assembly preferably has a hydraulic branch, by which hydraulic fluid supplied to the attachment 67 via the hydraulic supply interface is supplied to the hydraulic actuators of the attachment 67 as needed. Preferably, the control valves each have two ports A and B, to which hydraulic fluid can be supplied as needed, with hydraulic fluid then being received in the other port B or A. Preferably, the hydraulic supply interface has a port P, to which pressurized hydraulic fluid is supplied, and a port T, through which hydraulic fluid can flow back into a tank of the work vehicle 66.The valve assembly 35 with the control valves is designed to distribute the pressurized hydraulic fluid supplied at P to the individual ports A and B of the individual hydraulic actuators as required, according to the control commands that the control valves receive from the control unit 34.

[0097] It is possible that the attachment 67 has precisely the hydraulic supply interface described. Conventional attachments often have several (separate) hydraulic supply interfaces for multiple hydraulic actuators. A valve assembly 35 with control valves for operating the hydraulic actuators of the attachment 67 is then typically mounted on the work vehicle. This concept can be departed from here: according to a concept proposed here, the attachment 67 has its own control unit 34, and the hydraulic interface serves (only) to provide pressurized hydraulic fluid as an energy source.

[0098] Preferably, only an electronic interface, in particular the implement bus interface 32, is provided for transmitting control commands for actuating the at least two hydraulic actuators from the work vehicle 66 to the implement 67. Preferably, all information for the operation of the implement 67 or the hydraulic actuators of the implement 67 is transmitted via the electronic interface, in particular the implement bus interface 32, and thus via the work vehicle bus system 15.

[0099] Preferably, the attachment 67 forms a self-contained system with the control unit 34, which communicates with the work vehicle bus system 15 via the attachment bus interface 32.

[0100] An operating system is preferably run on the control unit 6 of the work vehicle 66, on which computer program products 68 belonging to the attachment 67 can be installed and run. The computer program product 68 described here is preferably programmed and configured specifically for the respective attachment 67.

[0101] The operating device 9 of the work vehicle 66 is, for example, a joystick 10 permanently installed in the work vehicle 66. With the computer program product 68, it is possible to use such a joystick 10 or another operating device permanently installed in the work vehicle 66 to control the attachment 67. In particular, the installation of special operating devices for the respective attachment 67 in the work vehicle can be dispensed with.

[0102] The computer program product 68 is particularly preferably set up to display functions of the attachment 67 for an operator on a display or display device 7 of the work vehicle 66.

[0103] The described attachment 67 and the computer program products 68, 69 define a novel interface between attachments 67 and work vehicles 66. Communication with the work vehicle 66 is implemented via the work vehicle bus system 15. The HMI devices (operating devices such as joysticks, displays, or the existing bus infrastructure) present in the work vehicle 66 are used to control the attachment 67. A display in the work vehicle 66 can be used, in particular, for an operator to select and visualize the functionalities of the attachment 67.

[0104] The control unit 34 of the attachment 67 controls the control valves of the valve assembly 35 of the attachment 67 and detects the current state of the attachment 67 using the described sensors. Based on this information, together with the current control commands transmitted via the work vehicle bus system 15, the control unit 34 calculates new setpoint commands for the control valves in the valve assembly 35 of the attachment 67.

[0105] On - the control unit 6 of the work vehicle 66 is a computer program product 68 or - A computer program product 69 is installed in the control unit 34 of the attachment 69, which enables an operator to control or actuate / operate the attachment 67 via the control device 9 of the work vehicle 66. Preferably, the computer program product 68, 69 is also configured to output information about the operation / actuation and, if applicable, the status of the attachment 67 and its hydraulic actuators on the display device 7 of the work vehicle 66.

[0106] It is possible that the attachment 67 can basically be operated autonomously when - Provision of the hydraulic fluid supply from work vehicle 66 and - Provision of the electrical or electronic control signals that are transmitted from the work vehicle 66 to the attachment 67 via the attachment bus interface 32, - Transmission of operating parameters of the attachment 67, in particular based on the measurement signals from the pressure sensors and / or motion sensors, via the attachment bus interface 32 from the attachment 67 to the work vehicle, - electrical power supply between work vehicle 66 and attachment via a suitable plug or power supply connection. REFERENCE MARK LIST 1 vehicle combination 2 tractors 3 attachments 4 front loaders 5 tools 6 Control unit 7 Display device 8-inch screen 9 Control unit 10 Joystick 11 Engine 12 gearboxes 13 Hydraulic system 14 Pump 15 work vehicle bus system 16 ISOBUS 17 Control unit 18 hydraulic unit 19 Work vehicle bus interface 20 attachment bus interface 21 Attachment bus system 22 Supply line 23 Work vehicle supply interface 24 Attachment supply interface 25 Supply line 26 Hydraulic system 27 Attachment bus system 28 Supply line 29 Attachment supply interface 30 Work vehicle supply interface 31 Supply line 32 Attachment bus interface 33 Work vehicle bus interface 34 Control unit 35 Valve assembly 36 lifting cylinders 37 tilt cylinders 38 Pressure sensor 39 Pressure sensor 40 motion sensors 41 Pressure sensor 42 Pressure sensor 43 Motion sensor 44 motion sensor 45 motion sensor 46 Control unit 47 Valve assembly 48 actuator cylinders 49 Pressure sensor 50 pressure sensor 51 motion sensor 52 Hydraulic system 53 Supply line 54 Tool supply interface 55 Attachment supply interface 56 Tool bus system 57 Tool bus interface 58 Attachment bus interface 59 hydraulic actuator 60 Tool holder 61 Swingarm 62 Swing strut 63 Swing strut 64 Cross brace 65 Cover 66 work vehicle 67 Attachment 68 Computer program product 69 Computer program product 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] DE 10 2005 048 280 B4

[0013] DE 10 2005 053 041 A1 [0014, 0025] DE 10 2009 046 213 B4

[0015] EP 1 813 730 B1

[0016] EP 1 903 147 B1

[0017] EP 2 840 186 B1

[0018] EP 3 158 842 B1

[0019] EP 3 431 668 B1

[0020] EP 4 144 925 A1

[0021] EP 23185 356.5

[0025]

Claims

[1] Attachment (67), in particular front loader (4), with a) a hydraulic system (26) with at least two hydraulic actuators (59) and b) an implement bus system (27) which has an implement bus interface (32) via which the implement bus system (27) can be connected to a work vehicle bus system (15), c) wherein the implement bus system (27) is connected directly or via a control unit (34) of the implement (67) ca) is coupled with pressure sensors (38, 39, 41, 42) in such a way that measurement signals from the pressure sensors (38, 39, 41, 42) or signals dependent thereon can be transmitted via the implement bus system (27), and / or cb) is coupled with motion sensors (40, 43) in such a way that measurement signals from the motion sensors (40, 43) or signals dependent thereon can be transmitted via the attachment bus system (27). [2] Attachment (67) according to claim 1, wherein a) the attachment (67) has an electronically controlled valve assembly (35), b) the attachment (67) has a hydraulic attachment supply interface (29) which is connected to the electronically controlled valve assembly (35) of the attachment (67), and c) the valve assembly (35) controls or regulates the hydraulic actuation of the hydraulic actuators depending on information transmitted via the attachment bus system (27). [3] Attachment (67) according to any of the preceding claims, wherein the attachment (67) a) has a stroke sensor that detects the stroke of a lifting cylinder (36) of the attachment (67), preferably the stroke sensor being integrated into the lifting cylinder, and / or b) has a tilting position sensor that detects the tilting position of a tilting cylinder (37) of the attachment (67), preferably the tilting position sensor being integrated into the tilting cylinder, and / or c) has a pressure sensor (38, 39, 41, 42) that detects a pressure applied to a pressure chamber of a hydraulic actuator, in particular the lifting cylinder (36) or the tilting cylinder (37), and / or d) comprising a pair of pressure sensors (38, 39; 41, 42) which detect the pressures applied to opposing pressure chambers of a double-acting hydraulic actuator, in particular the lifting cylinder (36) or tilting cylinder (37), and / or e) has an angle sensor which detects a swivel angle of a swing arm of the attachment (67) relative to a column of the attachment (67), and / or f) has an angle sensor which detects a swivel angle of a tool holder of the attachment (67) relative to a swing arm of the attachment (67). [4] Attachment (67) according to one of the preceding claims, wherein the attachment bus system (27) has a tool bus interface (57) via which the attachment bus system (27) can be connected to a tool bus system (56). [5] Attachment (67) according to one of the preceding claims, wherein the attachment (67) has a further attachment bus system, wherein the attachment bus system (27) and the further attachment bus system are connected to each other via a control unit (34), wherein preferably the further attachment bus system does not communicate directly with the work vehicle and the tool and / or preferably the attachment bus system is designed as an ISOBUS, while the further attachment bus system is designed as a CAN bus system and serves to connect to the sensors and / or the valve device. [6] Attachment (67) according to one of the preceding claims, wherein the attachment bus interface (32) is designed for a connection for automatic coupling of the attachment to the work vehicle and / or the attachment bus interface (32) is integrated into an overall interface serving further functions, in which hydraulic connections are also integrated. [7] Vehicle combination (1) with a) a work vehicle (66), in particular a tractor (2), which has a work vehicle bus system (15) which communicates with an operating device (9) of the work vehicle (66) and has a work vehicle bus interface (33), and b) an attachment (67), in particular a front loader (4), according to any one of claims 1 to 6, c) wherein the work vehicle bus system (15) and the implement bus system (27) are coupled to each other via a connection between the work vehicle bus interface (33) and the implement bus interface (32). [8] Vehicle combination (1) according to claim 7, wherein the work vehicle (66) has an ISOBUS socket in the rear area, which is intended for connection with a rear-mounted implement which may be driven by a power take-off shaft, and a cable connection of the work vehicle bus system (15) designed as ISOBUS runs from the rear area to the front area of ​​the work vehicle (66), where the coupling with the implement bus system (27) also designed as ISOBUS takes place via interfaces, wherein preferably a branch plug or branch point is inserted into the ISOBUS socket already present in the rear area, which enables a branch into an ISOBUS line that is connected to the implement in the rear area, and has an ISOBUS line that runs along the work vehicle from the rear area to the front area and enables coupling with the work vehicle bus system (15) in the front area.wherein in particular the latter ISOBUS strand is routed below the work vehicle (66) in the longitudinal direction of the work vehicle (66) along the work vehicle (66) from the rear area to the front area. [9] Attachment (67) according to one of claims 1 to 6 or vehicle combination (1) according to claim 7 or 8, wherein the work vehicle (66) and / or the attachment (67) has / has a control unit (6, 34) with control logic which coordinates the operation of the work vehicle (66) and the operation of the attachment (67) via the attachment bus interface (32). [10] Attachment (67) or vehicle combination (1) according to claim 9, wherein the control logic is designed such that a) a determination of the load carried by the attachment (67) and a coordinate of the center of gravity of the load carried by the attachment (67) is carried out, wherein, in particular, after the determination of the load and the coordinate of the center of gravity of the load, the same are taken into account for the control of the operating positions of the attachment (67) and from the load and the coordinate of the center of gravity it is determined when a critical operating condition of the attachment (67) and the working vehicle is reached, which may result in reduced stability with the risk of tipping over, and / or b) an automatic oscillating movement of a tool holder of the attachment (67) can be brought about, preferably in order to shake off material adhering to the inner surfaces of the bucket if it is not automatically completely emptied by tilting, or to compact material arranged in a bucket, wherein in particular the automatic oscillating movement is triggered by a switch or a joystick, whereby the control logic then hydraulically actuates the tilting cylinder in such a way as to bring about the oscillating tilting movement, and / or an amplitude of the oscillation is specified by the switch or the extent of an actuation of the joystick, and / or an amplitude of the oscillation is constant for a predetermined period of time or for the duration of an actuation of an actuating element, or decays and decreases over time, and / or c) Automatic vibration damping of the attachment (67) is achieved, preferably by damping the resulting dynamic oscillations of the attachment (67) by increasing the throttling effect of throttles in the supply lines to the pressure chambers of the actuator cylinders or by actively counteracting this by selectively applying pressure to the pressure chambers of the actuator cylinders in such a way as to reduce the resulting vibration, and / or d) by means of suitable control of a valve device, automatic control and / or regulation of the distribution of a supply flow of the hydraulic fluid, which is transferred from the work vehicle to the attachment, to the lifting cylinder, the tilting cylinder and / or at least one further hydraulic actuator is carried out, wherein preferably the distribution is carried out in such a way that, despite different pressures of the individual consumers, the consumers are operated to the required extent, or the control logic distributes the supply flow based on a prioritization such that a higher-priority consumer is provided with the entire supply flow or a minimum portion of the supply flow for at least a period of time, and / or e) damping is achieved in the area of ​​an end position of a stroke of the lifting cylinder (36) and / or a tilting cylinder (37) and / or a hydraulic actuator (59), wherein the damping preferably consists of detecting by means of motion sensors when the actuating cylinder is at a predetermined distance from the end position, and then, when this is the case, and the actuating cylinder continues to approach the end position, a valve device is actuated by means of the control logic in such a way that a lower actuating speed is achieved, which can then lead to reduced stop forces, or the speed is successively reduced in stages or continuously as the end position is approached, and / or a frequency of the oscillating movement is specified by the driver and / or different specific frequencies are possible or the frequency of the oscillating movement depends on the load, and / or f) a reduction of the movements of a tool holder and / or a chassis of the work vehicle (66) when the vehicle combination (1) is driven on an uneven road surface is controlled or regulated, and / or (g) an automatic activation and / or deactivation of an all-wheel drive of the work vehicle (66) depending on an operating state of the work vehicle (66), and / or h) a float function is provided in which preferably opposing pressure chambers of an actuator are short-circuited via the valve assembly of the attachment or connected to each other via a throttle of the valve assembly of the attachment, resulting in the actuator being able to be adjusted when external forces are applied to the attachment, and / or i) pressure regulation of the pressures in the lifting cylinder (36) and / or tilting cylinder (37) and / or a hydraulic actuator (59) is carried out and / or j) a lifting speed and / or tilting speed is controlled or regulated depending on a load and / or k) at least one predetermined operating state or operating state sequence of the attachment (67) is stored and the stored predetermined operating state or operating state sequence is automatically brought about and / or I) a control and / or regulation of a parallel guidance of a tool holder is carried out, wherein preferably the control logic, in parallel with the actuation of the lifting cylinder, also actuates the tilting cylinder in such a way that the pivoting of the tool holder resulting from the actuation of the lifting cylinder is counteracted by the actuation of the tilting cylinder so that no change in the orientation of the tool occurs, wherein in particular the control logic takes into account a previously learned, read-in or user-selected type of attachment and / or type of tool for determining the automatic actuation of the lifting cylinder and the tilting cylinder to ensure the parallel guidance of the tool holder, and / or m) a limitation of the stroke of the lifting cylinder (36) and / or of the stroke of a tilting cylinder (37) and / or of a hydraulic actuator (59) is carried out and / or n) a locking and / or unlocking of a locking device for locking a tool to the tool holder of the work vehicle (66) takes place, wherein preferably a locking and / or unlocking of the locking device is only possible in selected operating positions or operating position ranges, wherein in particular the control logic uses the measuring signals of the motion sensors and / or an unlocking of the tool is only made possible by means of the control logic when the attachment is lowered, and / or o) an automatic adjustment of the maximum driving speed of the work vehicle (66) is carried out in relation to a load carried by the attachment (67) and / or p) a predetermined dependence of the angle of the tool holder on the stroke of the lifting cylinder (36) is established, wherein preferably the predetermined dependence is a guide such that the control of the lifting cylinder and the tilting cylinder is carried out in such a way that, during lifting or lowering, the angle of the tool holder has a predetermined profile, wherein in particular the profile is such that, regardless of the actuation of the positioning cylinders, the tool holder always has the same angle relative to the ground, thus ensuring parallel guidance, or tilting of the tool automatically occurs during lifting and lowering, and / or q) a speed scaling function is executed in which different conversion characteristics are used by means of the control unit, the control logic and the valve assembly of the attachment to convert a signal specified by the driver via a joystick and transmitted via the attachment bus interface into a control of the lift cylinder and / or the tilt cylinder, and / or r) a speed mode is ensured, and / or s) a control of a pump of the work vehicle (66) depending on a load carried by the attachment (67). [11] Attachment (67) or vehicle combination (1) according to claim 9 or 10, wherein a) the control logic is designed such that pressure regulation is carried out on the basis of measurement signals for the pressures in the lifting cylinder and / or tilting cylinder and / or any further hydraulic actuator of the attachment or tool, so that the operating positions of the valve device for generating the control pressures for the lifting cylinder, tilting cylinder or any further hydraulic actuator are regulated by means of the control logic and control unit, and / or b) the control logic is designed such that a pressure control includes a pressure limit that avoids high pressures that could lead to damage, and / or c) a tool is designed as a bale grab, which is hydraulically actuated by an actuating cylinder of the tool, and the clamping force of the bale grab is limited on the basis of a pressure control, and / or d) different tools can be mounted on the attachment, which have hydraulic actuators requiring different maximum operating pressures, and the control logic, based on manually entered or automatically detected information about which tool is coupled to the attachment, imposes a tool-specific pressure limit, and / or e) the control logic is designed such that a pressure relief function is ensured when a hydraulic motor is operated on a tool, whereby the pressure relief prevents overloading of the motor and the tool by controlling the valve device when the pressure exceeds a predefined threshold value, such that no further pressure increase occurs or the pressure decreases, wherein, in particular, information is transmitted via the bus system to the work vehicle and the user via a monitor or other display device that an overload or improper operation has occurred, and / or f) the control logic is designed such that, based on a determined load and / or center of gravity, the operating speeds of the actuator cylinders are limited, and / or g) the control logic is designed such that the type of attachment with its kinematics and dimensions or related characteristic parameters is stored on the one hand, and the kinematic parameters or characteristic parameters of the tool on the other hand, wherein preferably a one-time calibration of an attachment and / or tool is carried out by determining the respective parameters in a test operation with subsequent storage of this data, and then, when a specific tool and / or a specific attachment is used in the vehicle combination, it is automatically recognized or manually selected by the user and the determined parameters are read out and used for the subsequent operation with the attachment or tool, and / or h) the control logic is appropriately designed to add up the multiple determined loads to a total weight when multiple weighing operations are performed, and / or. (i) the control logic is designed such that when a specific operating state of the attachment and / or tool is brought about, the specific operating state is stored, in particular by storing the pressures with which the pressure chambers of the lifting cylinder and the tilting cylinder and any further actuator are actuated and / or the measurement signals of the motion sensors in the specific operating state, wherein if such an operating state is to be restored to a later state, this is done automatically by the control logic automatically acting upon the hydraulic actuators in such a way that this stored operating state is restored.wherein, in particular, the automatic restoration of the stored operating state is manually triggered by the driver, or automatic triggering occurs depending on any operating state of the vehicle combination or based on the recognition of a specific geodetic position of the vehicle combination via a GPS system or upon reaching a position range, wherein preferably an operating state history is stored and restored, and a stored operating state history includes an initial position in which a front loader is lowered and a bucket held on the front loader rests flat on the ground, and subsequently the bucket is raised by actuating the lifting cylinder, wherein during this process the bucket is tilted backwards by actuating the tilting cylinder and an end position is then reached.when the front loader boom with the implement is at a predetermined working height, and the stored operating state history includes the operating parameters and profiles between the starting position and the end position, and if the same operating state history is required at a later time, the operator does not initiate this operating state history by specifically controlling the lift cylinder and the tilt cylinder, but rather an automatic restoration of the operating state history occurs through the control logic, and / or, (j) the implement receives at least one control variable via the implement bus interface, which is specified by the operator via a control device or joystick in the cab of the work vehicle and / or is automatically specified by a control unit of the work vehicle depending on the operating state of the work vehicle and which is a target stroke of an actuator cylinder or hydraulic actuator, wherein the control variable is independent of which specific implement and / or which specific tool is attached to the work vehicle, and the control unit of the implement has control logic that adapts the control of the valve device to the specific implement and / or the specific tool, and / or k) image signals are transmitted via the attachment bus system. [12] Attachment (67) or vehicle combination (1) according to one of the preceding claims, wherein the attachment bus system is coupled to a tool bus system of a tool via suitable interfaces. [13] Attachment (67) or vehicle combination (1) according to one of the preceding claims, wherein a tool database is available in which a) specific characteristics of tools that can be coupled to a tool holder of the attachment (67), and / or b) specific characteristics of implements (67) can be stored. [14] Attachment (67) or vehicle combination (1) according to one of the preceding claims, wherein for automatic identification of a specific attachment and / or a specific tool the attachment or tool has an RFID chip, barcode or QR code which includes an identifier of the respective type of attachment or tool and is read for type identification, wherein the tool or attachment is preferably identified by means of automatic image recognition of an image taken by a camera. [15] Attachment (67) or vehicle combination (1) according to one of the preceding claims, wherein the attachment (67) receives a control variable via the attachment bus interface (32), which is specified in particular via an operating device (9) or a joystick (10) of the work vehicle (66) or a control unit (6) of the work vehicle (66), and the control unit (34) of the attachment (67) has control logic which controls the valve assembly (35) of the attachment to generate the hydraulic actuation of the lifting cylinder (36), the tilting cylinder (37) and / or the actuator (59) taking into account the received control variable and a) specific characteristics of a tool which is coupled to a tool holder of the attachment (67), and / or b) specific characteristics of the geometry of the attachment (67) and / or c) controls specific characteristics of the lifting cylinder (36), the tilting cylinder (37) and / or the actuator (59). [16] Attachment (67) or vehicle combination (1) according to one of the preceding claims, wherein the attachment (67) has an interface via which operating data of the attachment (67), in particular a load determined by the attachment (67), can be transmitted. [17] Computer program product (68; 69) configured for operation on a control unit (6) of an attachment (67) or a vehicle combination (1) according to one of the preceding claims, wherein the computer program product (68; 69) is configured to enable an operator to control the attachment (67) with an operating device (9) of the work vehicle (66) via control commands and to transmit the control commands for controlling hydraulic actuators (59) of the attachment (67) via a work vehicle bus system (15), a work vehicle bus interface (33), an attachment bus interface (32) to an attachment bus system (27). [18] Computer program product (68; 69) according to claim 17, configured to display on a display device (7) of the work vehicle (66) functions or operating states or measurement signals of pressure sensors (38, 39, 41, 42) or motion sensors (40, 43) of the attachment (67) or of a tool held thereon to an operator. [19] Use of a control unit (6, 34) of an attachment (67) or a vehicle combination (1) according to one of the preceding claims for controlling or regulating a hydraulic actuation of the hydraulic actuators via a valve device (35) depending on information transmitted via an attachment bus system (27).

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