Apparatus for connecting an implement to a work machine, and method for monitoring a mechanical load on said apparatus

Abstract

An apparatus (4) for connecting an implement to a work machine (1) has a rotation device (5), by means of which an implement connection device (7) can be rotated about an axis of rotation relative to a work machine connection device (6). The rotation device has a worm gear with a driveable worm shaft having an external thread, and a worm wheel which is mounted for rotation about the axis of rotation and is in meshing engagement with the external thread of the worm shaft. In a measuring section of the worm shaft between the first bearing device and the external thread, a force measuring device for acquiring force characteristic variables for axial forces exerted on the measuring section of the worm shaft and directed in an axial direction along the worm shaft axis is arranged on or in the worm shaft.

Description

[0001] Device for connecting a work tool to a

[0002] Working machine and method for monitoring a mechanical load on this device

[0003] The invention relates to a device for connecting a working tool to a working machine, wherein the device comprises a working machine connection device for connection to the working machine, a working tool connection device for connection to the working tool, and a rotation device with which the working tool connection device is rotatable relative to the working machine connection device about an axis of rotation, wherein the rotation device comprises a worm gear with a driveable worm shaft having an external thread, and a worm wheel rotatably mounted about the axis of rotation, which meshes with the external thread of the worm shaft, wherein the worm shaft is rotatably mounted along a worm shaft axis extending transversely to the axis of rotation in a first bearing device arranged along the worm shaft axis at a distance from the external thread.wherein the rotating device has a drive unit which is operatively connected to a drive section of the worm shaft, and with which the worm shaft can be driven to a rotational movement about the worm shaft axis. Such devices, with which a working tool can be rotatably attached to a machine and used on the machine for the respective purpose, are suitable and known for a wide variety of applications. The machine can, for example, be a construction machine such as an excavator, and the working tool can be a tool or an interchangeable attachment such as an excavator bucket. Such a connecting device with a swiveling mechanism can also be a component of a truck-mounted crane or a container crane, a machine tool,a machining plant or a component of a process automation system. The machine connection device and the tool connection device are each suitably designed and configured to ensure a reliable and sufficiently mechanically robust connection between the machine and the tool with the device, and to allow for a quick and reliable fastening process as well as any possible removal and replacement process.

[0004] The rotary device described above is characterized by the highly reliable operation of its swivel mechanism, which can transmit high forces and torques during operation. An exemplary embodiment of such a rotary device is shown and described, for example, in DE 10 2013 206 574 A1. The rotary device comprises a worm gear with a worm wheel rotatably mounted about an axis of rotation and a worm shaft. The worm shaft can be driven to rotate and is operatively connected to the worm wheel via an external thread, such that a rotational movement of the worm shaft about its axis causes a rotational movement of the worm wheel about its axis of rotation. The rotational movement of the worm shaft can typically be effected hydraulically or with the aid of electric motors.Particularly when the device is used in construction machinery such as an excavator, the rotary device can be integrated into the drive concept of the construction machine and, for example, operated with a hydraulic device that is also used for operating the construction machine or the working tool of the construction machine.

[0005] It is known from practice that during the intended use of the device as a component of, for example, a construction machine, an unintentionally large mechanical load on the work tool or machine, or an excessive force, may occur, which could potentially lead to overloading and damage to the device or the components attached to it.

[0006] From DE 10 2022 132 871 B3, for example, it is known that a pressure relief valve is provided in a hydraulically operated rotary drive, which is opened in the event of an increase in the pressure of a hydraulic fluid in the hydraulic line used for actuating the rotary drive, and that the rotary drive is designed without a self-locking mechanism, so that a working device connected to the working machine via the rotary drive can be rotated freely and thus, in most cases, excessive mechanical stress and damage can be avoided.

[0007] From US 2018 / 0073945 A1, it is known to measure the forces acting on a hydraulically actuated cylinder piston in a hydraulically operated construction machine. A comparable approach is described, for example, in DE 10 2018 112 723 A1 of fenbart. Measuring forces acting on a hydraulic cylinder or other components of a hydraulic system is complex and only allows for an indirect determination of the mechanical load exerted on the device, and in particular on the swivel mechanism.

[0008] It is considered an object of the present invention to design a measuring device in such a way that an impending excessive stress on the rotational device of the apparatus can be detected and monitored as reliably as possible with the least possible effort.

[0009] This problem is solved according to the invention by arranging a force measuring device in a measuring section of the worm shaft between the first bearing assembly and the external thread for recording force parameters for axial forces exerted on the measuring section of the worm shaft and directed in an axial direction along the worm shaft axis on or in the worm shaft. Particularly in construction machinery such as an excavator, working implements such as an excavator bucket (also called a bucket) are advantageously equipped with a rotating device at one end of a bucket handle.

[0010] The excavator's bucket is fixed in such a way that it can be rotated around the end of the bucket arm. With such a rotation device, for example, a bucket used as a backhoe bucket can be transformed into a digging bucket by rotating it 180°, allowing the construction machine to be used for other tasks and work steps without having to change the attachment. In conjunction with a movable bucket arm and, if necessary, an additional swivel mechanism, the bucket then has many degrees of freedom for movement relative to the excavator's base.

[0011] Rotary devices with the features described above, or with a worm gear and a worm shaft driving a worm wheel, are known from practical experience and have proven very effective, among other things, in construction machinery. It has been shown that any overload of the rotary device can be reliably detected and monitored with minimal effort by arranging the force measuring device used for this purpose at a suitable location on or in the worm shaft, and by being able to detect at least the axial forces directed in one direction along the worm shaft axis.A suitable arrangement and mounting of the force measuring device between the first bearing assembly and the external thread of the worm shaft is easily achievable and allows for protected positioning of the force measuring device in a region of the worm shaft where the axial forces acting on the worm shaft can be reliably and precisely measured. In this way, both obstructions during a rotational movement of the rotating device as required during operation and externally acting torques can be detected. These external torques can act on the rotating device if it is fixed in rotation during operation, thereby exerting an additional torque on the rotating device.

[0012] The worm shaft preferably has a single-start external thread with a self-locking effect. However, it is also conceivable that the worm shaft has a multi-start external thread and, additionally or instead of a self-locking effect, a braking device with which rotational movement of the worm shaft can be hindered or completely prevented, for example, if the working tool is to be held and fixed in a predetermined orientation relative to the machine.

[0013] Additional measuring devices may be provided, but are not strictly necessary in practice for detecting and monitoring any potential overload of the rotating device. According to one embodiment of the invention, it is therefore also provided that only a single force measuring device is arranged on or in the measuring section of the worm shaft in the device, and that only this force measuring device detects and monitors the impending excessive stress on the rotating device.

[0014] According to an advantageous embodiment of the

[0015] The invention provides that the worm shaft has a measuring recess on an end face facing away from the external thread. This recess extends along the axis of the worm shaft in the direction of the external thread. The force measuring device is arranged and fixed in this recess so that tensile and / or compressive forces exerted on the worm shaft can be detected. It has been shown that when the force measuring device is arranged in a recess accessible from the end face of the worm shaft, a comparatively precise measurement of the axial forces acting on the worm shaft is possible, and the force measuring device is protected from mechanical stresses within the recess. Various designs of force measuring devices are known from practice that can be manufactured cost-effectively and fixed in the recess.By arranging it in the recess, no additional installation space is required for the arrangement of the force measuring device in an area around the worm gear.

[0016] According to a further aspect of the invention, the worm shaft can be rotatably mounted in a second bearing on the side of the external thread opposite the first bearing. The second bearing provides positive guidance for the worm shaft in such a way that transverse forces occurring perpendicular to the worm shaft axis can be absorbed by the two bearings, and the force measuring device essentially detects axial forces without the transverse forces unduly affecting the force parameters for the axial forces detected by the force measuring device or distorting the detection of the axial forces.

[0017] For many applications, it can be advantageous for the force measuring device to include a sensor and a power supply unit that provides electrical energy to the sensor. For the operation of the rotary device, it is often beneficial that the worm shaft can not only be pivoted around its axis over a certain angular range, but also that it can rotate continuously in one direction or the opposite direction around the axis and be driven accordingly. The force measuring device can use a battery as its power supply unit to power the sensor. However, with prolonged use of the rotary device, it is then necessary to replace or recharge the battery at intervals.

[0018] Advantageously, the power supply unit may include a power transmission device with which electrical energy can be transmitted wirelessly, i.e., without a continuous electrical conductor, from a power supply unit to the measuring recess of the worm shaft, which is rotatably mounted in the bearing assembly. The electrical energy can, for example, be transferred by induction from an energy storage unit outside the worm shaft to the force measuring device on or in the worm shaft. It is also conceivable that the electrical energy is transferred to the rotating worm shaft via brush contacts or friction contacts.

[0019] With a view to the most comprehensive possible evaluation of the force parameters recorded, possibly over a longer period, it may be advantageous, according to a further aspect of the invention, for the device to have a transmission device for transmitting the force parameters recorded by the force measuring device for axial forces exerted on the measuring section of the worm shaft to an evaluation device. This transmission can be provided either continuously, at time intervals, or only when needed and upon corresponding activation. The data transmission can be wired or wireless.The transmission device can optionally be designed and configured so that, in the event of an impending or already detected mechanical overload of the device, a warning signal or an alarm signal is transmitted to one or more recipients, for example as a message via the mobile network or the Internet.

[0020] It can also be advantageous, and is optionally provided, for the device to have a storage unit for storing a number of force parameters successively recorded by the force measuring device for axial forces exerted on the measuring section of the worm shaft. The storage unit can, for example, be designed to provide sufficient storage capacity for force parameters over an extended period of intended use of the device. The force parameters recorded by the force measuring device can then be stored completely in the storage unit and read out and evaluated as needed or at regular intervals. A comprehensive evaluation of the recorded force parameters is then possible even without a dedicated transmission device and without continuous transmission of the force parameters to an evaluation unit.This is particularly advantageous if continuous or reliable transmission of the recorded force parameters to the transmission device is not possible, for example, because a data transmission connection cannot be established between the transmission device and the evaluation device. The storage device can also store comprehensive information about specific events or times, so that, for example, in the event of an impending or actual overload of the device, additional data such as the time, further parameters, or specifications for the operation of the device and the associated machine and tool can be recorded and made available for later evaluation, in addition to the force parameters.

[0021] According to a particularly advantageous embodiment of the invention, the device also includes a pivoting device with which the implement connection device can be pivoted relative to the machine connection device about a pivot axis, wherein the pivoting device comprises a hollow cylinder, a piston shaft pivotably mounted in the hollow cylinder about a pivot axis, and an annular piston sleeve mounted axially displaceable in an axial direction along the pivot axis between the hollow cylinder and the piston shaft, the annular piston sleeve engaging with a piston shaft engagement section of the piston shaft adapted thereto via a sleeve piston engagement section, so that a forced axial displacement of the annular piston sleeve causes a pivoting movement of the piston shaft pivotably mounted in the hollow cylinder.wherein the piston shaft is rotatably mounted in the hollow cylinder via two radial bearings arranged axially spaced apart from each other, wherein the piston shaft has, successively in the axial direction between the two radial bearings, a ring piston sleeve sliding section with a sliding section diameter and the piston shaft engagement section with an engagement section diameter that is larger than the sliding section diameter, and wherein a torque measuring device is arranged on or in the piston shaft in the piston shaft engagement section, with which a torque parameter for a torque acting on the piston shaft can be detected.

[0022] With an additional swiveling device, the mobility and application possibilities of the implement connected to the machine can be significantly expanded, since the implement connection device can be swivelled relative to the machine connection device about a swivel axis, and thus the implement is not only rotatable but also swivelleable relative to the machine. A fundamentally suitable swiveling device is shown and described, for example, in DE 1 426 525 A1. In the swiveling device shown in DE 1 426 525 A1, the annular piston sleeve has a first steep thread engagement with the piston shaft engagement section of the piston shaft and a second steep thread engagement with an oppositely directed steep thread angle with the hollow cylinder surrounding the annular piston sleeve.In this way, large swivel angles between the piston shaft and the hollow cylinder can be achieved by a forced axial displacement of the ring piston sleeve, and large torques can be transmitted.

[0023] Since the piston shaft engagement section has a larger engagement section diameter than the sliding section diameter of the annular piston sleeve sliding section, the piston shaft engagement section forms a stiffer part of the piston shaft, through which a greater proportion of the forces and moments exerted on the piston shaft are transferred. Compared to an arrangement of the torque measuring device in the annular piston sleeve sliding section of the piston shaft, a torque measuring device arranged on or in the piston shaft engagement section of the piston shaft can detect a greater proportion of the moments exerted on the piston shaft and therefore a better estimation of an impending overload can be achieved.

[0024] The torque measuring device can continuously or at short intervals record torque parameters and compare these actual values ​​with a threshold value, which, for example, was determined and defined beforehand or determined and specified through simulations. If, in individual cases, the device, and in particular its swivel mechanism, is unintentionally damaged, the torque parameters recorded immediately before the damage, or the torque parameter trends over the period immediately preceding the damage, can be used to determine which torques caused the damage.

[0025] The piston shaft engagement section is defined as the section of the piston shaft which, compared to the sliding section diameter of the piston shaft in the annular piston sleeve sliding section, has an engagement section diameter that is larger than the sliding section diameter. The piston shaft engagement section typically extends axially over a region with a positive engagement with the annular piston sleeve to an associated end face of the piston shaft that is located a shorter distance from the steep thread. Similarly, the annular piston sleeve sliding section of the piston shaft extends axially to the end face of the piston shaft associated with the annular piston sleeve sliding section of the piston shaft that is located a greater distance from the engagement region of the piston shaft.In many cases, an arrangement of the torque measuring device that overlaps the engagement area in the axial direction can be advantageous.

[0026] However, it can also be provided that the torque measuring device is arranged in the immediate vicinity of the end face of the piston shaft associated with the piston shaft engagement section, between positively engaged engagement elements on the one hand and this end face on the other, and thus, for example, in an area of ​​a bearing assembly where no positive engagement is formed. Furthermore, the pivoting device can also be designed such that the annular piston sleeve is axially displaceable in the piston shaft engagement section and is rotationally connected to the piston shaft by means of a suitable positive guide, while a steep thread engagement used for the pivoting movement is formed between the annular piston sleeve and the surrounding hollow cylinder.

[0027] Due to the positive engagement between the piston sleeve engagement section of the annular piston sleeve on the one hand and the piston shaft engagement section of the piston shaft on the other, a distance is regularly defined in this area between the positive engagement and an end face of the piston shaft associated with the piston shaft engagement section, regardless of the diameter of the piston shaft. This distance is shorter than the distance between this positive engagement and the opposite end face associated with the annular piston sleeve sliding section. Because of the shorter length between the end face and the positive engagement, the piston shaft engagement section is typically more torsionally rigid than the annular piston sleeve sliding section of the piston shaft. Therefore, for this reason as well, the arrangement of the torque measuring device in the piston shaft engagement section is advantageous.

[0028] For many applications, it is considered advantageous to have a steep thread engagement between the annular piston sleeve and the piston shaft in the engagement section, and also a steep thread engagement between the annular piston sleeve and the surrounding hollow cylinder. However, configurations of the pivoting device are also conceivable in which either a positive engagement between the hollow cylinder and the annular piston sleeve or a positive engagement between the annular piston sleeve and the piston shaft is not designed as a steep thread engagement, but rather as a twisted positive engagement with, for example, axially extending serrations.The swiveling device can, for example, be designed in such a way that the ring piston sleeve is axially displaceable in the piston shaft engagement section and is connected to the piston shaft in a twisted manner with the aid of a suitable positive guide, while a steep thread engagement used for the swiveling movement is formed between the ring piston sleeve and the surrounding hollow cylinder.

[0029] The annular piston sleeve sliding section typically has a cylindrical surface with a uniform sliding sleeve diameter. The diameter of the piston shaft engagement section is regularly larger so that, due to the larger diameter, the externally arranged engagement elements and the moments acting upon them have the largest possible lever arm relative to the pivot axis, thereby enabling the reliable absorption and transmission of higher torques. The respective diameter is determined along the axial direction as the distance between opposing areas of a cylindrical surface that circumferentially rests against and encloses the piston shaft. For example, the engagement section diameter of the piston shaft engagement section in an area with a radially outwardly projecting steep thread is...

[0030] Nominal diameter of the steep thread, and in an area without a radially outwardly projecting steep thread, the diameter of the cylindrically shaped piston shaft in this area. Regardless of the design and arrangement of the positive engagement between the annular piston sleeve and the piston shaft, the section of the piston shaft with the larger diameter is considered and designated as the piston shaft engagement section, even if the positive engagement should be arranged in a section of the piston shaft with a smaller diameter, so that, according to the invention, the torque measuring device is always arranged in an axial section of the piston shaft with a larger diameter than in an opposite section with a smaller diameter.

[0031] For detecting and monitoring excessive torque loads, a torque measuring device arranged on or in the piston shaft engagement section of the piston shaft is sufficient. In this way, the torque exerted on the piston shaft during operation can be continuously detected with minimal manufacturing and evaluation effort. According to one embodiment of the invention, it is therefore also provided that the device contains only a single torque measuring device arranged on or in the piston shaft engagement section of the piston shaft, and that only this torque measuring device detects and monitors the impending excessive stress on the swivel mechanism of the device.The measured values ​​acquired by the torque measuring device, which correlate with the torque exerted on the piston shaft, can be continuously compared with a torque threshold during operation. A warning signal can be triggered if the measured values ​​exceed the torque threshold, thus indicating an impending overload of the piston shaft and consequently of the swivel mechanism or the entire device. It is also possible to save the measured values ​​acquired by the torque measuring device and, if necessary or at regular intervals, to evaluate the stored data in order to, for example, identify load peaks and to assess increasing material fatigue or an impending failure of the swivel mechanism.

[0032] According to a particularly advantageous embodiment of the invention, the piston shaft has a measuring recess on an end face facing the piston shaft engagement section. This recess extends axially into the piston shaft engagement section, and the torque measuring device is arranged and fixed in this recess so that a torque parameter for a torque acting on the piston shaft can be detected. By arranging the torque measuring device in the measuring recess, the device is protected during operation by the surrounding areas of the piston shaft. Furthermore, the torque measuring device can advantageously be arranged and fixed in the recess such that the torque acting on the piston shaft is measured in a way that allows the torque to be measured in the recess.

[0033] Moments can be precisely measured. Optionally, the torque measuring device includes a deformation body with a deformation zone and a sensor device located within that zone. The deformation body is force-transmittingly fixed in the measuring recess, allowing the sensor device to detect the mechanical stress transmitted to the deformation body by the piston shaft and the resulting deformation of the deformation zone. Suitable deformation bodies are available in various designs and combinations with different sensor devices, enabling the torque measuring device to be procured cost-effectively and installed in the piston shaft.

[0034] Advantageously, it is optionally provided that an elastically deformable press-fit element is arranged at each of two opposite ends of the deformation body, so that the press-fit element adapts to an inner wall of the measuring recess and is pressed firmly against the inner wall, thereby transferring a mechanical stress from the piston shaft to the deformation body via the press-fit elements and causing a deformation of the deformation area of ​​the deformation body that can be detected by the sensor device. A torque measuring device designed in this way is disclosed, for example, in EP 4 185 850 A1. Such a torque measuring device can also be inserted into a recess not designed as a precision bore with minimal assembly effort and reliably fixed in such a way that the moments acting on the piston shaft can be transferred to the deformation body and reliably and precisely detected there by the sensor device.

[0035] According to an advantageous embodiment of the invention, the torque measuring device can further be arranged in an axial direction at least partially overlapping with a radial bearing of the piston shaft. In the area of ​​a radial bearing, the piston shaft expediently has a radially projecting and particularly deformation-resistant ridge or flange, so that this area of ​​the piston shaft absorbs a particularly high proportion of the forces and torques exerted on it. This makes the measured values ​​acquired by the torque measuring device particularly meaningful and allows for reliable detection and monitoring of the torque exerted on the piston shaft.

[0036] Optionally, in addition to the torque measuring device in the annular piston sleeve sliding section of the piston shaft, a first auxiliary measuring device may be arranged on or in the piston shaft. This auxiliary measuring device allows for the acquisition of a first auxiliary parameter for forces and / or torques acting on the piston shaft. By using an auxiliary measuring device and arranging it in a different area of ​​the piston shaft, which has a different stiffness due to its sliding section diameter differing from and being smaller than that of the piston shaft engagement section, an auxiliary parameter for a torque acting on the piston shaft can be acquired. This auxiliary parameter can then be used to support, control, and, if necessary, improve the evaluation of the torque parameter acquired by the torque measuring device.For example, a correlation between the auxiliary parameters recorded by the auxiliary measuring device and the torque parameters recorded by the torque measuring device can be determined in advance for a number of predefined torques and stored in a characteristic map or in a parameter set for a correlation function in order to monitor the torque parameter recorded by the torque measuring device during operation based on the auxiliary parameters recorded by the auxiliary measuring device and to avoid or at least identify any malfunctions or disturbances in the recording of the torque parameter and the monitoring of a load on the piston shaft.

[0037] It is also conceivable that, with the auxiliary measuring device and the auxiliary parameters recorded by the auxiliary measuring device, the influence of the ring piston sleeve, which may shift axially, and thus of the thread engagement between the ring piston sleeve and the piston shaft, can be detected and taken into account when determining a torque acting on the piston shaft, since an axial shift of the ring piston sleeve and thus of the positive engagement with the piston shaft can lead to a change in the stiffness of the piston shaft in the piston shaft engagement section.

[0038] It is also conceivable that the auxiliary measuring device could detect forces acting on the piston shaft. In this way, in addition to the mechanical load caused by torque, unexpected shock loads or tensile and compressive forces exerted on the piston shaft in addition to torque could also be detected.

[0039] The auxiliary measuring device can comprise one or more sensors spaced apart from each other on or in the piston shaft. The sensors can be designed, configured, and arranged such that they can detect either moments or forces, or both, acting on the piston shaft.

[0040] According to a further embodiment of the invention, a fixing device for securing the hollow cylinder to the machine or tool is arranged on an outer surface of the hollow cylinder, and a second auxiliary measuring device is arranged on or in the fixing device, with which at least one second auxiliary parameter for forces and / or moments acting on the hollow cylinder can be detected. With such a second auxiliary measuring device, moments or forces acting on the fixing device of the hollow cylinder of the pivoting device, in which the piston shaft is pivotably mounted, can also be detected. By a suitable arrangement and design of the second auxiliary measuring device, additional information about the mechanical loads occurring in the device during operation of the machine can be acquired.This information can be used, for example, to identify and, if necessary, differentiate between various causes of gradual or sudden damage to the device. It can also be used to record and analyze the loads expected to occur during operation over a longer period, in order to improve the design and dimensioning of the entire device as well as individual components.

[0041] With a view to the most comprehensive possible evaluation of the torque parameters, which may be recorded over a longer period, it may be advantageous, according to a further aspect of the invention, for the device to have a transmission device for transmitting the torque parameters recorded by the torque measuring device for a torque acting on the piston shaft to an evaluation device. The transmission device can be designed and configured such that auxiliary parameters and secondary auxiliary parameters, if any, can also be transmitted to the evaluation device. Transmission can be provided either continuously, at time intervals, or only when needed and activated accordingly. Data transmission can be wired or wireless.The transmission device can optionally be designed and configured so that, in the event of an impending or already detected mechanical overload of the device, a warning signal or an alarm signal is transmitted to one or more recipients, for example as a message via the mobile network or the Internet.

[0042] It can also be advantageous for the device to have a storage unit for storing a number of torque parameters successively acquired by the torque measuring device for a torque acting on the piston shaft. The storage unit can, for example, be designed to provide sufficient storage capacity for torque parameters over an extended period of intended use of the device. The torque parameters acquired by the torque measuring device can then be stored completely in the storage unit and read out and evaluated as needed or at regular intervals. A comprehensive evaluation of the acquired torque parameters is then possible even without a dedicated transmission device and without continuous transmission of the torque parameters to an evaluation unit.This is particularly advantageous if continuous or reliable transmission of the recorded momentary parameters to the transmission device is not possible, for example, because a data transmission connection cannot be established between the transmission device and the evaluation device. The storage device can also store comprehensive information about specific events or times, so that, for example, in the event of an impending or actual overload of the device, additional data such as the time, further parameters or specifications for the operation of the device and the associated machine and tool, or time-relevant auxiliary parameters, can be recorded and made available for later evaluation.

[0043] The invention also relates to a method for monitoring the mechanical load on a device for connecting a working tool to a machine, wherein the device has one of the previously described combinations of features. According to the invention, a force parameter detected by the force measuring device for axial forces exerted on the measuring section of the worm shaft and directed in an axial direction along the worm shaft axis is transmitted to an evaluation device, and the evaluation device checks whether the force parameter is less than or greater than a predefinable force parameter threshold. The evaluation device can be arranged in the device itself, so that the evaluation of the detected force parameters can be carried out within the device itself.The evaluation unit can also be located on or in the machine and, if applicable, also on or in the implement to which the device is connected. Alternatively or additionally, the evaluation unit can also be located externally and continuously or at time intervals transmit force parameters to the external evaluation unit for evaluation.

[0044] Furthermore, it can be advantageously provided that a number of the force parameters successively recorded by the force measuring device for axial forces exerted on the measuring section of the worm shaft are transmitted to a storage device and stored there. The storage device can also be arranged on or in the device, or it can be an external storage device to which the force parameters must be transmitted continuously or at time intervals. Various embodiments of the device are described below.

[0045] The inventive concept is explained in more detail, exemplified in the

[0046] The drawings are shown. It shows:

[0047] Fig. 1 shows a perspective view of a working machine, represented as an example of a construction machine, to which a device for connecting a working tool to the working machine is attached.

[0048] Fig. 2 shows a perspective view of a rotating device which is arranged in the device according to Fig. 1 between a working machine connection device of the device for connection with the working machine and a working tool connection device of the device for connection with the working tool.

[0049] Fig. 3 shows a sectional view of the rotary device shown in Fig. 2 with a rotatably mounted worm wheel and a worm shaft meshing with the worm wheel.

[0050] Fig. 4 shows a perspective view of a hollow cylinder and a piston shaft pivotably mounted therein, which can be integrated as part of a pivoting device in the device shown in Fig. 1.

[0051] Fig. 5 shows a sectional view through the hollow cylinder shown in Fig. 4 with the piston shaft mounted therein and an annular piston sleeve that can be displaced in an axial direction between the piston shaft and the hollow cylinder. Fig. 6 shows a perspective view of the piston shaft shown in Figs. 4 and 5 with a piston shaft engagement section and an annular piston sleeve sliding section.

[0052] Fig. 7 shows a side view of the piston shaft shown in Fig. 6.

[0053] Fig. 8 shows a perspective view of a combination of the rotary device shown in Figs. 2 and 3 with the hollow cylinder and the piston shaft pivotably mounted therein, as shown in Figs. 4 and 5.

[0054] Fig. 9 shows a sectioned view of the combination shown in Fig. 8, cut into two parts.

[0055] Fig. 10 shows a perspective view of a device with a swiveling device and with a rotating device, and

[0056] Fig. 11 shows a perspective view of the machine also shown in Fig. 1 with the device shown in Fig. 10.

[0057] A working machine 1, shown in Fig. 1 as an example of a construction machine or hydraulic excavator, has a device 4 at an outer end 3 of a lever arm 2 (also called a hopper handle) for connecting a working tool (not shown in the figures) to the working machine 1. The device 4 has a [missing information] shown enlarged and in more detail in Figs. 2 and 3.

[0058] The rotating device 5 is arranged in the device 4 between a working machine connection device 6, arranged above it in Fig. 1, for connection to the working machine 1, and a working tool connection device 7, arranged below it in Fig. 1, for connection to the working tool (not shown in detail). The working tool connection device 7 is rotatably connected to the working machine connection device 6 by the rotating device 5 and is rotatably mounted thereon.

[0059] Figures 2 and 3 show a perspective view and a sectional view of the rotary device 5. The rotary device 5 has a worm gear 8, which is rotatably mounted in a rotary device housing 9 about a rotation axis 10 of the worm gear 8. A worm shaft 11 is also arranged in the rotary device housing 9 and is rotatably mounted about a worm shaft axis 12 in a first bearing arrangement 13 and in a second bearing arrangement 14 spaced apart from it. The worm shaft 11 has an external thread 15, which has one thread and is self-locking.The external thread 15 is spaced apart from the first bearing assembly 13 and arranged between the first bearing assembly 13 and the second bearing assembly 14, and is arranged and adapted to the worm gear 8 such that the external thread 15 meshes with the worm gear 8 on a circumferential surface of the worm gear 8, so that a rotational movement of the worm shaft 11 causes a rotational movement of the worm gear 8 about the axis of rotation 10. The worm shaft 11 can be driven by means of a drive device 16, which is operatively connected to the worm shaft 11, and can be set into rotational movements about the worm shaft axis 12 in either direction.

[0060] In a measuring section 17 of the worm shaft 11, which is arranged axially along the worm shaft axis 12 between the first bearing assembly 13 and the external thread 15, a recess 18 is formed which is accessible from an end face 19 of the worm shaft 11. A force measuring device 20 is arranged in this recess 18 and is fixed in such a way that force parameters for axial forces exerted on the measuring section 17 of the worm shaft 11 and directed in the axial direction along the worm shaft axis 12 can be recorded with this force measuring device 20.The meshing engagement between the external thread 15 of the worm shaft 11 and the worm wheel 8 generates an axial force acting on the worm wheel 8 via the external thread 15 through the external thread 15, whereby a force parameter for a tensile or compressive force exerted on the worm shaft 11 in the measuring section 17 can be recorded with the force measuring device 20.

[0061] The force measuring device 20 comprises a sensor device (not shown in detail in the figures) and a power supply device (also not shown in detail) that supplies the sensor device with electrical energy. The power supply device includes a power transmission device by which electrical energy can be wirelessly transmitted from a power supply device to the measuring recess 18 of the worm shaft 11, which is rotatably mounted in the first and second bearing arrangements 13 and 14.

[0062] The device 4 can also incorporate a pivoting device 21, shown in various views in Figures 4 and 5 as well as in Figures 8 to 11, as exemplified in Figures 10 and 11. The pivoting device 21 comprises a hollow cylinder 22 and a piston shaft 24 pivotably mounted therein about a pivot axis 23 extending in an axial direction, which are shown separately in Figures 4 and 5. The piston shaft 24 is supported in the hollow cylinder 22 by two radial bearings 25, which are arranged at opposite ends of the piston shaft 24. The radial bearings 25 also provide axial support and prevent axial displacement of the piston shaft 24 relative to the surrounding hollow cylinder 22 during operation. A ring piston sleeve 26 is arranged between the piston shaft 24 and the hollow cylinder 22 which surrounds the piston shaft 24 in a radial direction.The annular piston sleeve 26 is supported at an end face 27 by a sliding ring 28 on an annular piston sleeve sliding section 29 of the piston shaft 24. At an opposite end, the annular piston sleeve 26 has a sleeve piston engagement section 30 with an inwardly formed steep thread, which engages with a corresponding outwardly formed steep thread in a piston shaft engagement section 31 of the piston shaft 24. The annular piston sleeve 26 engages with the surrounding hollow cylinder 22 in a sleeve cylinder engagement section 44 via a further positive engagement.The annular piston sleeve 26, through the sliding ring 28 and a fluid-tight annular seal 32, divides a hollow cylindrical cavity 33, which surrounds the piston shaft 24 between the two radial bearings 25, into two fluid-filled pressure chambers 34, 35. These chambers can be alternately pressurized, thereby forcing an axial displacement of the annular piston sleeve 26. The steep thread engagement between the sleeve piston engagement section 30 and the piston shaft engagement section 31 converts this forced axial displacement of the annular piston sleeve 26 into a pivoting movement of the piston shaft 24, which engages the annular piston sleeve 26 via the steep thread engagement. In this way the piston shaft 24 can be pivoted relative to the hollow cylinder 22 and thereby a corresponding pivoting movement of the working tool connection device 7 relative to the working machine connection device 6 can be effected.

[0063] The annular piston sleeve sliding section 29 of the piston shaft 24 has a sliding section diameter DG. The piston shaft engagement section 31 of the piston shaft 24 has an engagement section diameter DE. The sliding section diameter DG is smaller than the engagement section diameter DE. For this reason, the stiffness of the piston shaft 24 in the piston shaft engagement section 31 of the piston shaft 24 is greater than in the annular piston sleeve sliding section 29 of the piston shaft 24.

[0064] During the intended use of the device 4, torques act on the piston shaft 24. The intended use of the device 4 is expediently limited to movements and loads that are considered safe for the device 4 and do not regularly represent excessive stress on the device 4. However, it cannot be ruled out, and occasionally occurs in practice, that, for example, during normal use of the device 4 in a construction machine 1 for moving a bucket, the bucket encounters an unexpected obstacle that hinders the continuation of the intended movement sequence for the bucket, thereby causing an unexpectedly high mechanical load on the device 4.

[0065] To monitor undesirable excessive stress on the device 4 and, if necessary, to warn of an impending overload, a torque measuring device 38 is arranged and fixed in a recess 37 accessible from an end face 36 in the piston shaft 24 such that torque parameters can be detected with the torque measuring device 38, each of which correlates with a torque exerted on the piston shaft 24. Since the torque measuring device 38 is arranged in the piston shaft engagement section 31 of the piston shaft 24, which has a higher stiffness than the opposing annular piston sleeve sliding section 29 of the piston shaft 24, torque parameters can be detected with this arrangement of the torque measuring device 38, on the basis of which a more precise and reliable determination of the torques exerted on the piston shaft 24 is possible.It may optionally be provided that the recess 37 with the one arranged therein is additionally spaced apart.

[0066] In the area 39 of the annular piston sleeve sliding section 29, indicated only by way of example in Fig. 5, a first auxiliary measuring device 40 is arranged on or in the piston shaft 24, with which a first auxiliary characteristic value for forces and / or torques acting on the piston shaft 24 can be detected. Due to the different stiffness of the piston shaft 24 in the annular piston sleeve sliding section 29 compared to the piston shaft engagement section 31 of the piston shaft 24, the torque characteristics or first auxiliary characteristics detected by the torque measuring device 38 and by the first auxiliary measuring device 40 will differ, even if the torque measuring device 38 and the first auxiliary measuring device 40 are identically designed and configured and are arranged and fixed in a comparable manner in the piston shaft 24.By conducting preliminary reference measurements with a reference piston shaft 24, a characteristic map with torque parameters and initial auxiliary parameters can be determined if required, and a correlation between the torque parameters and the initial auxiliary parameters can be established. In this way, the initial auxiliary parameters can be used to check the plausibility and error-free recording of the corresponding torque parameters. It is also possible to improve the precision and accuracy in determining the actual torque acting on the piston shaft 24 by considering the initial auxiliary parameters, and thus also to make the monitoring of an impending or already occurring overload of the piston shaft 24 and therefore of the pivoting device 21 more reliable. It can additionally be provided that an external...

[0067] lateral surface 41 of the hollow cylinder 22 a

[0068] A fixing device 42 for fixing the hollow cylinder 22 to the working machine 1 or to the working device is arranged, and a second auxiliary measuring device 43, shown only schematically in Fig. 4, is arranged on or in the fixing device 42, with which at least a second auxiliary parameter for forces and / or moments acting on the hollow cylinder 22 can be detected.

[0069] Figures 6 and 7 each show a view of the piston shaft 24 with the annular piston sleeve sliding section 29 and the piston shaft engagement section 31 for illustrative purposes. In the piston shaft engagement section 31, the piston shaft 24 has an outwardly formed steep thread, which engages with the adapted and inwardly formed steep thread of the sleeve piston engagement section 30 of the annular piston sleeve 26 (not shown). The sliding section diameter DG is smaller than the engagement section diameter DE.

[0070] In Figures 8 and 9, the hollow cylinder 22 with the piston shaft 24 mounted therein, as shown in Figures 4 and 5, is mounted on the rotary device 5 shown in Figures 2 and 3. With the torque measuring device 38 arranged in the piston shaft 24 of the swiveling device 21 and the force measuring device 20 arranged in the worm shaft 11 of the rotary device 5, torque and force parameters for forces and moments exerted on the device 4 can be reliably recorded, and thus the mechanical load on the device 4 can be determined and monitored.

[0071] Figure 10 shows the device 4 with the machine connection device 6 for connecting to the machine 1, the implement connection device 7 for connecting to an implement (not shown), the pivoting device 21 arranged between the machine connection device 6 and the implement connection device 7, and the rotation device 9 also arranged between the machine connection device 6 and the implement connection device 7. With this device 4, for example, a bucket fixed to the implement connection device 7 and connected via the device 4 to the bucket arm of a machine 7 designed as an excavator can be aligned in almost all directions and moved over the bucket arm within a large working range.With the torque measuring device 24 and the force measuring device 43, a mechanical load on the device 4 and thus on the spoon and the working machine 1 can be detected and monitored during the use of the working machine 1.

[0072] In Fig. 11, a working machine 1 is shown for illustrative purposes only, as in Fig. 1, as an example of a construction machine or hydraulic excavator. The working machine 1 has, on the lever arm 2 (also referred to as the boom handle), a device 4 for connecting a working implement (not shown in the figures) to the working machine 1 at the outer end 3 of the lever arm 2. The device 4 corresponds to the variant shown in Fig. 10 and, in addition to the rotating device 5 shown enlarged and in more detail in Figs. 2 and 3, also has the pivoting device 21 shown in Figs. 4 and 5. With this device 4, the working implement connection device 7 can be both rotated and pivoted with the

[0073] Working machine connection device 6 connected and mounted on it so as to be rotatable and pivotable.

Claims

P A T E N T A N S P R Ü C H E 1. Device (4) for connecting a working tool to a working machine (1), wherein the device (4) comprises a working machine connection device (6) for connection to the working machine (1), a working tool connection device (7) for connection to the working tool, and a rotation device (5) with which the working tool connection device (7) is rotatable relative to the working machine connection device (6) about an axis of rotation (10), wherein the rotation device (5) comprises a worm gear with a driveable worm shaft (11) having an external thread (15), and a worm wheel (8) rotatably mounted about the axis of rotation (10), which meshes with the external thread (15) of the worm shaft (11).wherein the worm shaft (11) is rotatably mounted and axially fixed along a worm shaft axis (12) extending transversely to the axis of rotation (10) in a first bearing device (13) arranged along the worm shaft axis (12) at a distance from the external thread (15), wherein the rotation device (5) has a drive device (16) which is operatively connected to a drive section of the worm shaft (11) and with which the worm shaft (11) can be driven to a rotational movement about the worm shaft axis (12), characterized in that a force measuring device (20) is provided in a measuring section (17) of the worm shaft (11) between the first bearing device (13) and the external thread (15) for, Measurement of force parameters for forces exerted on the measuring section (17) of the worm shaft (11) and in an axial direction Axial forces directed along the worm shaft axis (12) are arranged on or in the worm shaft (11).

2. Device (4) according to claim 1, characterized in that the worm shaft (11) has a measuring recess (18) extending along the axis of the worm shaft (12) in the direction of the external thread (15) on an end face (19) of the worm shaft (11) facing away from the external thread (15), in which the force measuring device (20) is arranged and fixed in such a way that tensile and / or compressive forces exerted on the worm shaft (11) can be detected by the force measuring device (20).

3. Device (4) according to claim 1 or claim 2, characterized in that the worm shaft (11) is rotatably mounted on a second bearing device (14) on one side of the external thread (15) opposite the first bearing device (13).

4. Device (4) according to one of the preceding claims, characterized in that the force measuring device (20) has a sensor device and a power supply device that supplies the sensor device with electrical energy.

5. Device (4) according to claim 2 and claim 4, characterized in that the power supply device has a power transmission device with which electrical energy can be wirelessly transmitted from a Energy supply device into the measuring recess (18) of the rotatably mounted in the bearing device (13) worm shaft (11) is transferable.

6. Device (4) according to one of the preceding claims, characterized in that the device (4) has a transmission device for transmitting the force parameters detected by the force measuring device (20) for axial forces exerted on the measuring section (17) of the worm shaft (11) to an evaluation device.

7. Device (4) according to one of the preceding claims, characterized in that the device (4) has a storage device for storing a number of force parameters successively recorded with the force measuring device (20) for axial forces exerted on the measuring section (17) of the worm shaft (11).

8. Device (4) according to one of the preceding claims, characterized in that the device (4) has a pivoting device (21) with which the working implement connection device (7) can be pivoted relative to the working machine connection device (6) about a pivoting axis (23), wherein the pivoting device (21) has a hollow cylinder (22), a piston shaft (24) pivotably mounted in the hollow cylinder (22) about a pivoting axis (23) and an annular piston sleeve (26) mounted between the hollow cylinder (22) and the piston shaft (24) so ​​as to be displaceable in an axial direction along the pivoting axis (23), the annular piston sleeve (26) being positively locked to the surrounding hollow cylinder (22) via a sleeve cylinder engagement section (44) and to a sleeve piston engagement section (30) The piston shaft engagement section (31) of the piston shaft (24) is adapted to this, so that a forced axial displacement of the annular piston sleeve (26) causes a pivoting movement of the piston shaft (24), which is pivotably mounted in the hollow cylinder (22), relative to the hollow cylinder (22), wherein the piston shaft (24) is rotatably mounted in the hollow cylinder (22) via two radial bearings (25) arranged axially spaced apart from each other, wherein the piston shaft (24) has, successively in the axial direction between the two radial bearings (25), an annular piston sleeve sliding section (29) with a sliding section diameter (DG) and the piston shaft engagement section (31) with an engagement section diameter (DE) that is larger than the sliding section diameter (DG), and wherein a torque measuring device (38) is arranged on or in the piston shaft (24) in the piston shaft engagement section (31).with which a moment parameter for a torque acting on the piston shaft (24) can be determined.

9. Device (4) according to claim 8, characterized in that the piston shaft (24) has a measuring recess (37) extending axially into the piston shaft engagement section (31) on an end face (36) facing the piston shaft engagement section (31), in which the torque measuring device (38) is arranged and fixed in such a way that a torque parameter for a torque acting on the piston shaft (24) can be detected with the torque measuring device (38).

10. Device (4) according to claim 9, characterized in that the torque measuring device (38) has a deformation body which has a deformation area and a sensor device which is fixed in the deformation area, and that the deformation body is fixed in the measuring recess (37) in a force-transmitting manner, so that a mechanical stress transmitted to the deformation body due to the mechanical stress of the piston shaft (24) and thereby forced deformation of the deformation area of ​​the deformation body can be detected with the sensor device.

11. Device (4) according to claim 10, characterized in that an elastically deformable press-in element is arranged at each of two opposite ends of the deformation body, such that the press-in element adapts to an inner wall of the measuring recess (37) and is pressed forcefully against the inner wall and thereby a mechanical stress of the piston shaft (24) is transferred via the press-in elements to the deformation body and causes a deformation of the deformation area of ​​the deformation body that can be detected by the sensor device.

12. Device (4) according to one of the preceding claims 8 to 11, characterized in that the torque measuring device (38) is arranged in the axial direction at least partially overlapping with a radial bearing (25) of the piston shaft (24).

13. Device (4) according to one of the preceding claims 8 to 12, characterized in that, in addition to the torque measuring device (38) in the A first auxiliary measuring device (40) is arranged on or in the piston shaft (24) in the ring piston sleeve sliding section (29) of the piston shaft (24), with which a first auxiliary characteristic parameter for a torque acting on the piston shaft (24) can be detected.

14. Device (4) according to one of the preceding claims, characterized in that a fixing device (42) for fixing the hollow cylinder (22) to the working machine (1) or to the working device is arranged on an outer cylindrical surface (41) of the hollow cylinder (22), and that a second auxiliary measuring device (443) is arranged on or in the fixing device (42), with which at least a second auxiliary characteristic parameter for forces and / or moments acting on the hollow cylinder (22) can be detected.

15. Method for monitoring a mechanical load on a device (4) for connecting a working tool to a working machine (1) according to one of claims 1 to 14, characterized in that a force parameter detected by the force measuring device (20) for axial forces exerted on the measuring section (17) of the worm shaft (11) and directed in an axial direction along the worm shaft axis (12) is transmitted to an evaluation device and checked with the evaluation device whether the force parameter is smaller or larger than a predefinable force parameter threshold value.

16. Method according to claim 15, characterized in that a number of the force measuring devices are successively connected to the force measuring device. (20) recorded force parameters for the measurement section (17) axial forces exerted on the worm shaft ( 11 ) on a The data is transmitted to the storage device and stored there.

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