FI3862490T3

FI3862490T3 - Mobile working machine with a tool holding device for holding a working tool

Info

Publication number: FI3862490T3
Application number: FIEP21154069.5T
Authority: FI
Inventors: Stephan Engler; Josef Schele; Martin Anders
Original assignee: Kramer Werke Gmbh
Priority date: 2020-02-10
Filing date: 2021-01-28
Publication date: 2024-04-17
Also published as: EP3862490B1; EP3862490A3; DE102020103320A1; EP3862490A2

Description

1 EP3 862 490

MOBILE WORKING MACHINE WITH A TOOL HOLDING DEVICE FOR

HOLDING A WORKING TOOL

Description

The invention relates to a mobile working machine having a tool holding device for holding a working tool according to the preamble of claim 1.

State of the art

Mobile working machines, in particular wheel loaders, telescopic loaders, diggers, tractors or the like, having a vehicle chassis and a drive unit for driving at least one drive element, e.g., a driven wheel and/or a tracked vehicle driving gear, nowadays often have so-called "quick changers" for attachable tools such as buckets, grab buckets, snow plows, snow blowers, forks, digger buckets, digger grabs, or the like.

These standardized quick-change systems usually operate hydraulically to actuate the coupling/uncoupling or locking/unlocking of the implement or of the tool from the cab. It is often necessary to change different tools several times a day. In some cases, in addition to purely "passive" tools, "active" tools or working devices such as hydraulic hammers, brooms or grab buckets, i.e., with "active" or adjustable or (motor) driven components, are used.

For these "active" or driven components, power transmission from the vehicle to the tool is therefore required.

In addition to the hitherto relatively few electric "active" tools or implements with electric motors, electromagnets or the like, "active" implements/tools are usually driven hydraulically, for example by means of hydraulic cylinders or hydraulic motors, so that a hydraulic connection must also be established or released during the tool change. In the case of commercially available wheel loaders or diggers, telescopic loaders, etc., the driver must still climb down to manually couple and uncouple this hydraulic connection/line. This is inconvenient and time-consuming for the driver and sometimes leads to injury or faults in the hydraulics when getting in and out, e.g., due to haste.

2 EP3 862 490

However, quick-change systems have already become known from EP 1 329 559 A2,

DE 697 17 080 T2 or DE 692 10 405 T2, wherein hydraulic coupling/uncoupling of the attachment is also made possible at the same time as the mechanical coupling or locking/unlocking. However, these systems have hitherto not been able to establish themselves in the market or on the construction sites.

As is known, such construction vehicles or implements are subjected to very high and very rough conditions during operation. On the one hand, construction site dirt and, on the other hand, the sometimes large forces that act on the components and can deform/bend them, can impair the functionality of the couplings, both of the hydraulic and of the mechanical coupling components. For example, the implements can also become dirty during long periods of the non-use, which in particular can impair the hydraulic coupling components and would have to be prevented by attaching closure plugs or the like. However, the driver must then in turn manually attach and remove such closure plugs before and after the tool change and leave the driver's cab for this purpose.

Object and advantages of the invention

In this respect, the object of the invention is to propose a mobile working machine having a tool holding device that at least partially improves the disadvantages of the prior art and that, in particular under construction site conditions, can reliably ensure preferably trouble-free and/or fully automated operation or tool change, even over a longer period of time.

Proceeding from a mobile working machine of the type mentioned in the introduction, this object is achieved in particular by the features of claim 1.

Advantageous embodiments and developments of the invention are possible by the measures mentioned in the dependent claims.

Accordingly, a mobile working machine according to the invention having a tool holding device is characterized in that the first receptacle device of the working tool and/or the first transmission device of the working tool has at least one first dirt opening and/or a first dirt duct for discharging and/or conducting dirt.

3 EP3 862 490

With this measure, any contamination or dirt that may be present during or even as a result of the coupling or locking can be eliminated or at least reduced. A "self- cleaning system" can thus advantageously be implemented according to the invention. Accordingly, the operational reliability can be improved or, even in the case of rough and dirty construction site conditions, a long or low-trouble/trouble- free mode of operation can be achieved for so-called "quick changers." Thus, even in the case of "active tools" or implements having an integrated actuator, such as a motor, linear drive or the like, it is possible to implement, for example, a "fully automatic" change of tool or implement, i.e., without manual handling of the implement or without the driver having to leave the cab. The latter in particular reduces the risk of injury to the driver considerably/completely and also saves a lot of time. Working machines are currently already in use that have implements, working devices or tools having electric actuators such as electric motors or electric coils/magnets, etc. For this purpose, an electrical power transmission from the drive vehicle or from the wheel loader, digger, telescopic loader or the like to the implement or tool is to be provided. In some cases, the drive vehicle has at least one electric drive of the running wheel(s) and/or at least one hydraulic system to operate, for example, the lift frame or lift/support arm and/or the steering system, in particular a pivot steering system.

According to the invention, at least one hydraulic unit comprising at least one hydraulic fluid and/or one hydraulic oil is provided, wherein in particular the hydraulic unit comprises at least one first piston, which is adjustable in a hydraulic cylinder, and/or the power transmission unit. In this way, existing, proven components can be advantageously used, which allow for a cost-effective and reliable working machine according to the invention. The working tool or implement can thus advantageously have a hydraulic actuator, preferably a hydraulic cylinder having a piston.

According to the invention, at least one position sensor for at least detecting the piston in a terminal position region and/or the first locking bar element in the unlocking position is provided, and/or a first activation element for activating the first locking bar element of the locking unit and/or the piston is provided. The object of the invention can thus also be achieved, namely to improve, at least in part, the disadvantages of the prior art and, in particular under construction site

4 EP3 862 490 conditions, to be able to reliably ensure preferably trouble-free and/or fully automated operation or tool change, even over a longer period of time. For example, by knowing or detecting the position of the piston or locking element, it is possible to ensure that the working tool is securely locked or fixed to/with the tool holding device. This is of great importance to a considerable extent for operational reliability and/or for trouble-free coupling or uncoupling, in particular of the power transmission unit and/or of the hydraulic system or of hydraulic components such as hydraulic couplings/connections.

According to the invention, the hydraulic unit has at least one pressure valve, such as a pressure relief valve, etc., for relieving the pressure of the hydraulic unit, and a second activation element for activating the pressure relief valve, wherein a control unit is configured in such a manner that the first locking bar element is activatable in the unlocking position when the second activation element is activated. This makes it possible, for example, to first relieve the pressure of the hydraulic unit; only then can the (first) locking bar element be actuated. Thus, in particular in hydraulic systems, it can be ensured that no, or at least very little, hydraulic fluid/oil escapes or leaks when the hydraulic coupling/connection is coupled/decoupled or connected or disconnected. In this way, adhesive bonding of the oil with dirt can be effectively prevented, and thus impairment of the next coupling and disadvantageous oil loss can be effectively prevented. Accordingly, the object according to the invention is also achieved by this measure.

According to the invention, at least one activation sensor is provided for detecting a position of the (first) activation element. The object of the invention can thus also be achieved, namely to improve, at least in part, the disadvantages of the prior art and, in particular under construction site conditions, to be able to reliably ensure preferably trouble-free and/or fully automated operation or tool change, even over a longer period of time. For example, by knowing or detecting the position of the at least one activation element or of a plurality of activation elements, it is possible to ensure that the working tool can be securely locked or can be fixed to/with the tool holding device. For example, a pressure relief/reduction of the power transmission unit and/or of the transmission device and/or of the transmission element can thus be achieved or a power supply can be shut off/prevented. This is of great importance to a considerable extent for operational reliability and/or for trouble-

EP3 862 490 free coupling or uncoupling, in particular of the power transmission unit and/or of the hydraulic system or of hydraulic components such as hydraulic couplings/connections.

Preferably, a two-stage or multi-stage mode of operation/circuit is advantageous. 5 In a first stage, the power supply or pressurization is shut off/interrupted or at least advantageously reduced. In a second stage, for example, the coupling/locking or the uncoupling/unlocking is made possible only by means of the activation sensor and/or a control unit or the like. In this case, an actuation of an activation element or of the first activation element, in particular of a switch such as a locking button/switch/pushbutton or the like, and the detection of this activation or its position by means of the advantageous sensor can advantageously release a further or second activation element or this can be operationally ready in order to realize the locking or unlocking. For example, a toggle switch or the like is used, which only has to be released by pressing or actuating a locking button/slide or a second switch/pushbutton/activation element or the like.

Advantageously, the first activation element and the second activation element are configured as separate switches for two-handed operation, wherein a switch spacing between the first activation element/switch and the second activation element/switch is provided. The switch spacing is, for example, at least as large as a hand. Advantageously, the driver must thereby actuate the two switches with both hands in order to operate or actuate them. It is thereby advantageously ensured that no unintentional, in particular simultaneous activation of the two activation elements or switches can take place during the work or operation of the support/lifting arm and/or the tool. This also improves operational reliability.

According to the invention, it is generally advantageous that at least one length- compensation unit is provided for compensating differences in length oriented along the second adjustment path. In this way, manufacturing tolerances and/or damage or deformations or the like that occur over time due to the rough operating or construction site conditions can advantageously be compensated. The power transmission can thus also be ensured in the case of differently sized second adjustment paths or spacings/distances between the releasing position and the

6 EP3 862 490 transmitting position of the adjustable transmission element, i.e., different differences in length according to the invention.

At least the length-compensation unit is preferably designed at least as a hydraulic fluid, in particular a hydraulic oil, and/or the first hydraulic length-compensation unit comprising the first piston, which is adjustable in the hydraulic cylinder, wherein provided is in particular a pressure limiting valve for limiting pressure. On the one hand, a relatively large length difference and/or a length difference varying over time can thereby be bridged or adapted to the invention, even if unintentional deformations of the tool holding device occur due to external forces. Thus, with this measure, the object of the invention can also be achieved, namely to reliably ensure, even under construction site conditions, preferably trouble-free and/or fully automated operation or tool change, even over a longer period of time.

The advantageous pressure limiting valve limits the maximum pressure of the system or of the hydraulic cylinder/piston so that the transmission element rests/is pressed firmly but not too firmly against the transmission device. In addition, energy savings are thereby realized because the hydraulic system, in particular during continuous operation, only has to apply the limited contact pressure or transmission pressure and not the maximum system pressure. The hydraulic components are also correspondingly protected, which improves/extends the life of the hydraulic system.

In a preferred variant of the invention, at least one transverse-adjustment unit is provided for adjusting different positions of the power transmission unit and/or the transmission element and/or the transmission device and/or receptacle device and/or the first locking bar element, which positions are oriented transverse/perpendicular to the second adjustment path. In this way, manufacturing tolerances and/or damage or deformations or the like that occur over time due to the rough operating or construction site conditions can advantageously be compensated. Accordingly, advantageous relative movements/adjustments can be realized between the coupling components in order to advantageously compensate for existing or occurring tolerances/deformations. In particular, the power transmission or the hydraulic fluid transmission can be ensured even in the case of different positions of the

7 EP3 862 490 corresponding components, i.e., different positions existing transversely to the second/first adjustment path.

In principle, it is at least conceivable that the power transmission or the transmission element/device is realized or operated largely separately and/or at a distance from the unlocking/locking or from the locking unit/locking bar element.

For example, the first adjustment path can be designed in parallel or even at an acute angle and/or with different lengths in relation to the second adjustment path.

However, in a particularly preferred embodiment of the invention, the first transmission element is at least partially disposed within the first locking bar element of the locking unit, and/or the first adjustable locking bar element and/or the first adjustable transmission element are/is at least partially disposed within the hydraulic cylinder, and/or the first adjustment part coincides with the second adjustment path. This not only reduces the design and economic effort, for example by implementing a common/single adjustment path actuator for the two identical adjustment paths of the (two) adjustable elements or components, in particular also by the "double use" of the first piston or hydraulic cylinder.

Thus, the operational reliability is also increased by the aforementioned advantageous measures in that, for example, the first locking bar element surrounds the first transmission element largely or completely, at least in the region of the coupling or locking, i.e., at the "interfaces" between/on the tool holding device and the working tool. In this case, in particular during coupling, there is a particularly high risk of damage or deformation of the above-mentioned components due to the large force/weights of such working machines and implements, in particular the components of the power transmission such as the hydraulic components or hoses/connections, which are "susceptible" in particular to external forces.

Advantageously, the first, adjustable locking bar element and/or the first, adjustable transmission element and/or the piston has at least one frontal end face oriented transversely to the first/second adjustment path, wherein at least one axial sealing element for sealing the transmission of the hydraulic fluid and/or the hydraulic oil is advantageously arranged on the frontal end face, wherein in particular the axial sealing element is arranged centrally about the longitudinal axis

8 EP3 862 490 of the piston/transmission element, for example as an O-ring or flat circular ring seal. For tight transmission of the hydraulic fluid and/or the hydraulic oil, the first, adjustable transmission element and/or the piston can certainly have a radial seal on the circumferential side or on the outer circumference, so that the hydraulic fluid or the oil is effectively sealed off from the outside.

The advantageous axial seal, i.e., the seal on the end face, along the adjustment path, with sealing surfaces oriented transversely/perpendicular to the adjustment path, however, advantageously allows an arrangement or dimensioning in which the sealing surfaces of the seal can be arranged very close to or directly at the coupling point or the flow opening of the hydraulic system. It is thereby achieved that very little or virtually no oil or fluid can leak or escape during coupling and uncoupling or during connection and during release. Somewhat larger amounts of escaping hydraulic fluid or oil can also become stuck with dirt/dust, which is disadvantageous for the coupling/uncoupling or for the hydraulic system and can impair operation.

In an advantageous variant of the invention, at least one first support element for supporting the working tool has at least one first receptacle opening for the first locking bar element and/or the hydraulic cylinder has at least one first end face oriented transversely to the first/second adjustment path, wherein in the locking position of the first locking bar element a first spacing is preferably provided between the first support element and the first end face of the hydraulic cylinder.

Thus, even in the case of certain deformations, in particular deformations occurring over the course of time, of the corresponding components, the coupling can be ensured and, above all, the power transmission can be ensured in the case of different or changed adjustment paths or spacings/distances, for example between the support element and the receptacle device and/or between the releasing position of the adjustable transmission element and the transmission device. In this way, for example, manufacturing tolerances and/or damage or deformations or the like, in particular of the tool holding device or the support element and/or the working tool, which occur over time due to the rough operating or construction site conditions, can advantageously be compensated.

9 EP3 862 490

Advantageously, the hydraulic/length-compensation unit and/or the first piston has at least a first detent face for stopping and/or limiting a stroke travel, wherein in particular the first detent face is configured as a frontal end face. Due to the advantageous stopping according to the invention, the hydraulic length- compensation unit or the piston can advantageously extend, i.e., for coupling/locking, until said hydraulic length-compensation unit or piston hits the first stop surface on the working device. This eliminates the need for purely mechanical or additional length adjustment.

The first receptacle device and/or the first transmission device of the working tool preferably has at least a second detent face for stopping on the first detent face of the piston and/or of the length-compensation unit. A clear definition or fixation of the adjustment path or of the extension of the piston or of the locking bar element can thus be implemented, so that even in the case of deformations, etc., of the corresponding components that occur over time, a contact and thus also advantageously a reliable locking or transmission of the power or of the hydraulic fluid/oil can advantageously be ensured. This in turn increases operational reliability or trouble-free operation and ensures a long service life.

According to the invention, the first locking bar element of the locking unit and/or the first piston of the hydraulic cylinder is designed as a dirt clearing element for at least partially clearing dirt from the first receptacle device of the working tool and/or from the first transmission device of the working tool. It is thus advantageously possible to eliminate or at least decisively reduce existing contamination or dirt/dust during or as a result of the coupling/locking by means of the dirt clearing element according to the invention. Accordingly, an automatic coupling of the working tool or a "self-cleaning system" can advantageously be realized according to the invention. This means that manual intervention or cleaning of the connection components or of the tool holding device and/or of the working tool, in particular of the components/elements for the power transmission, is unnecessary or can be omitted.

Accordingly, with a mobile working machine according to the invention, a complete fully automatic so-called "quick change" of the implement(s) can be realized, even in the case of "active" working devices with "actuators" or

10 EP3 862 490

Energy consumers such as motors, linear drives, cylinders or the like. As a result, it is possible to completely eliminate the need for the driver to leave the driver's seat or the driver's cab, compared to the prior art in previous so-called "quick- change systems." The latter in particular reduces the risk of injury to the driver considerably/completely and also saves a lot of time. All of this improves the operational reliability, as a result of which a long or low-trouble/trouble-free mode of operation can be achieved according to the invention, even or especially in the case of rough and dirty construction site conditions.

Preferably, the first dirt opening and/or the first dirt duct is arranged at least partially in the vertical direction below the first transmission element and/or the first locking element. The dirt can thus be removed by means of gravity, which is favorable from a design and cost standpoint.

In an advantageous embodiment of the invention, the first transmission device of the working tool has at least one first receptacle sleeve for receiving the first locking bar element, wherein the first receptacle sleeve comprises at least the first dirt duct and/or wherein at least the first dirt duct is arranged between the first support element and the first receptacle sleeve. For example, a clear spacing or air gap is provided between the tool holding device or the support element and the first transmission device of the working tool or the first receptacle sleeve.

Alternatively or in combination therewith, the first dirt duct can advantageously be aligned at an acute angle with respect to the first and/or second adjustment path.

Thus, the dirt can preferably be pushed by means of the dirt clearing element to or through the air gap or dirt duct or the dirt opening, or fall down/out through them, for example, onto the ground.

Advantageously, the first dirt duct has at least one ring duct of the first receptacle sleeve and/or the first transmission device. This measure ensures that dirt/dust can be at least partially removed, for example by means of the locking bar element/piston, in particular from the region/contact of the power transmission unit or a hydraulic line or hydraulic coupling, so that the contact or the contact surfaces are largely free of dirt/impurities at least between the transmission element and the transmission device. This also improves operational reliability, in particular power transmission.

11 EP3 862 490

In a special further development of the invention, the locking unit has at least one second, adjustable locking bar element, wherein the second locking bar element is arranged at least partially in a second receptacle device of the working tool in the locking position, and/or the power transmission unit has at least one second, adjustable transmission element, wherein the second transmission element is at least partially connected in the transmission position to a second transmission device of the working tool, and/or the first and the second, adjustable locking bar elements and/or the first and the second, adjustable transmission elements are arranged at least partially within the hydraulic cylinder of the hydraulic unit, and/or the first adjustment path of the first locking bar element is oriented in the opposite direction to the first adjustment path of the second locking bar element and/or the second adjustment path of the first transmission element is oriented in the opposite direction to the second adjustment path of the second transmission element. One or more of these measures can improve the power transmission and/or the holding/locking/fixing of the working tool.

A two-sided or "mirror-inverted" holding of the working tool about the central middle axis of the working machine can preferably be realized. On the one hand, this improves the mechanics/statics and, on the other hand, identical components can be used on the first and second sides. This also improves the economic efficiency of the invention.

In a preferred variant of the invention, at least the first piston and a second piston and/or the first and second adjustable locking bar elements and/or the first and second adjustable transmission elements are arranged in a common cylinder housing of the hydraulic cylinder. In this way, both pistons can advantageously be actuated or pressurized simultaneously and in the same way with a single or common hydraulic connection of the hydraulic cylinder. This not only reduces the number of components required, but also results in an advantageous hydraulic system and thus also to an advantageous locking and unlocking or adjustment of the two locking bar elements.

Exemplary embodiment

12 EP3 862 490

An exemplary embodiment of the invention is illustrated in the drawing and is explained in more detail below with reference to the figures.

In the figures:

Fig. 1 is a schematic, perspective view of a mobile working machine with an implement according to the invention,

Fig. 2 is a schematic view of the implement according to Fig. 1 with its hydraulic system,

Fig. 3 shows a coupling point according to the invention, schematically shown in a longitudinal section, in the locked position,

Fig. 4 shows the coupling point shown schematically in a longitudinal section according to the invention in different positions during a coupling process,

Fig. 5 shows a schematically illustrated receptacle sleeve of the implement according to the invention in a longitudinal section and in a cross section, and

Fig. 6 is a schematic excerpt of a hydraulic circuit diagram of the mobile working machine according to Fig. 1.

Fig. 1 schematically shows a wheel loader 1 or a mobile working machine 1 with an implement or a working tool 2 according to the invention. In the present case, the working tool 2 is a so-called "grab bucket" 2, i.e., this bucket is not only "passive," but a part of the grab bucket 2 can be actively adjusted by means of two hydraulic cylinders 3, for example for quick emptying of construction material such as gravel or sand. Accordingly, it is an "active working tool" 2 within the meaning of the invention, wherein power, i.e., in the present case, hydraulic energy by means of hydraulic oil, is advantageously to be transmitted from a drive vehicle 4 to the working tool 2.

Without more detailed representation, the drive vehicle 4 advantageously has a drive motor, in particular a diesel engine, and a hydraulic pump, in order, on the one hand, to provide the drive power for driven wheels, in particular for all-wheel drive, and, on the other hand, to provide the hydraulic power for a lifting arm 5, a

13 EP3 862 490 steering system 6, and the working tool 2 or the grab bucket 2, i.e., the hydraulic cylinders 3, and to be able to operate them accordingly.

A driver (not shown) controls the working machine 1 or the working tool 2 from a driver's seat 7 and, in addition to the steering system 6, also has an operating element 8 or a so-called "joystick" 8.

Furthermore, the wheel loader 1 has a tool holding device 9 or a so-called "quick- change system" or a so-called "quick-change plate," which in the present case can be in operative connection with two receptacles 10 of the working tool 2. Thus, on each side of the lifting arm 5, i.e., on both sides of a so-called longitudinal central plane of the drive vehicle 4, an upper recess of the receptacle 10 can receive a bolt 11 of the tool holding device 9, and a lower bore 12 of the receptacle 10 can receive a bolt 13 of the tool holding device 9 or a piston 13 of a hydraulic cylinder 14. Vertical and horizontal spacing as well as diameters/dimensions of the receptacles 10, bolts 13, bores 12, etc. are advantageously standardized, so that a wide variety of working tools 2 such as buckets, lifting forks, grippers, brooms, snow plows, etc. can be coupled and uncoupled, i.e., changed, quickly and without much effort on the lifting arm 5.

In "quick-change systems" according to the prior art, the driver did not have to leave the driver's seat 7 or a driver's cab in the case of "passive" working tools 2 and could carry out the change automatically. In contrast, in the case of "active" working tools 2, such as the grab bucket 2 shown, the driver had to leave the driver's cab or the driver's seat 7 to connect or release hydraulic couplings/hoses and/or to remove dirt from dirty coupling components, in particular the hydraulic couplings, especially of the working tool 2, which took a considerable amount of time and during which the driver may have repeatedly injured himself due to haste or carelessness.

Fig. 2 schematically shows the grab bucket 2 viewed from behind, wherein hydraulic lines are provided between the two hydraulic cylinders 3 and two transmission devices 14. These transmission devices 14 are arranged on the receptacles 10 or support arms 10, wherein holes or openings 15 are already visible in Fig. 2 on the underside of the transmission devices 14.

14 EP3 862 490

These openings 15 or holes 15 and their function can be clearly seen, especially in

Fig. 4. Fig. 4 shows different moments or positions in a locking or coupling process of the lifting arm 5 on/with the working tool 2. Fig. 4 a) only shows the support arm 10 or receptacle 10 of the working tool 2 with the transmission device 14, wherein the latter comprises a fixing bush 16 for fixing a receiving/centering bush 17 and a first hydraulic coupling element 18 of a hydraulic line.

In Fig. 4 b), the bolt 11 of the lifting arm 5 (not shown here) has already engaged in the upper region of the receptacle 10, wherein the locking bar 13 with a second hydraulic coupling element 19 arranged at the end or at the end face and a cylinder housing 20 for the locking bar 13, which is thus at the same time the piston 13 of a hydraulic cylinder 21 of the lifting arm 5 or of the tool holding device 9.

The individual illustrations of Fig. 4 also show, as an example, contamination with dirt 22 that has accumulated in the bore 12 and in the centering sleeve 17 due to a prolonged pause or non-use of the working device 2. This dirt 22 could impair the hydraulic coupling/connection by means of the two coupling elements 18, 19 and thus, among other things, the function of the cylinders 3 and/or lead to a (more extensive) leakage of this coupling. The two coupling elements 18, 19 advantageously each have valves (cf. Fig. 3), in particular check valves, in order to reliably seal the hydraulic system in the non-coupled state (cf. Fig. 4 b)) and only allow the hydraulic fluid to flow only in the coupled state according to Fig. 4 e). The open state of the valves is shown schematically in Fig. 3, wherein in addition the closed state of the valve of the locking bar/piston 13 is shown only schematically by dashed lines.

As is clear in Fig. 4 c), the locking bar 13 or the piston 13 clear/pushes the dirt 22 ofthebore 12 out of the bore by its adjustment or by its advance. In this case, this dirt 22 falls out of the opening 15 or duct 15 arranged below the bore 12. In the next illustration or Fig. 4 d), the locking bar/piston 13 is further extended and pushes/clears the dirt 22 in the centering sleeve 17 via a dirt duct 23 directed downwards at an acute angle in relation to the adjustment direction or the longitudinal axis of the hydraulic cylinder 21.

15 EP3 862 490

In the end position according to Fig. 4 e), the locking bar/piston 13 advantageously abuts the transmission device 14 or the centering sleeve 17 with a stop 25 or a ring surface 25 of its end face. In addition, an advantageous ring duct 24 is formed, wherein it is designed as a cavity between the locking bar/piston 13 or the stop 25 and the centering sleeve 17 or as a recess of the centering sleeve 17. In this case, the stop 25 is also designed as an axial seal 25 according to the invention. In this position, dirt 22 continues to fall through the duct 23 or is removed. Excessive or otherwise non-cleared/non-pushed-out dirt 22 can now advantageously remain in the ring duct 24 (for now) and optionally migrate downwards during operation and fall out through the duct 23. It is of great advantage that the locking bar/piston 13 abuts the end face by means of the ring surface or the stop 25, i.e., the adjustment path is limited by this and not by a stop of the piston 13 on the cylinder housing 20. This is somewhat clarified, among other things, in Fig. 3, wherein, in particular, in the end position, i.e., at a maximum adjustment path or stroke, there is advantageously a spacing 27 or cavity 27 between a shoulder 26 of the piston 13 and the cylinder housing 20. In this way, manufacturing tolerances and/or deformations or damage, for example of the receptacles 10 or the like, which occur over time, can advantageously be compensated. This is/can be achieved by allowing the piston(s) 13 of the hydraulic cylinder 21 to extend further, i.e., to have an adapted, longer adjustment path, for example when the spacing between the two receptacles 10 of the working device 2 is greater. It is thus ensured that the piston 13 or its coupling element 19 always extends to/abuts the coupling element 18 of the working device 2 or the transmission device 14 and a sealed hydraulic connection according to the invention is realized.

Furthermore, an air gap 28 or spacing 28 is provided between the receptacle 10 or the support arm 10 of the working device 2 and the hydraulic cylinder 21 or the cylinder housing 20. This axial spacing 28 or air gap 28 oriented in the direction of the adjustment path of the locking bar 13 or piston 13 is of great advantage, because usually the connection or the design between the tool holding device 9 or the so-called "quick-change plate" 9 and the working device 2 or the receptacles 10, this tolerance or such play is helpful for a jam-free suspension and hanging. In practice, this play or spacing 28 is usually between O and 10 mm. According to the

16 EP3 862 490 invention, this play or tolerance is advantageously hydraulically compensated by the hydraulic cylinder 21 or its changeable stroke length/adjustment path (see above). Overall, according to the invention, tolerances of more than approximately 10 mm can advantageously be compensated hydraulically, so that not only manufacturing tolerances, but also deformations/damage that occur over time due to the harsh operating conditions can be compensated. This ensures a particularly reliable mode of operation, in particular that the hydraulic coupling elements 18, 19 are (always) securely and completely connected, thus allowing for low-loss hydraulic energy/power transmission and ensuring a long service life.

Fig. 5is, on the one hand, a schematic view of a cross section (Fig. 5 a)) and, on the other hand, a schematic view of a longitudinal section (Fig. 5 b)) of the transmission device 14. In addition, a radial play 29 or gap 29 between the fixing bush 16 and the centering bush 17 is also advantageously provided. The play 29 makes it possible to compensate in particular for manufacturing tolerances or tolerances with respect to the (substantially vertically oriented) spacing between the bolt 11 or the of the corresponding recess of the receptacle 10 and the locking bar/piston 13. The centering bush 17 is thus advantageously adjustably mounted/clamped on the fixing bush 16, for example by means of a locking ring/washer or so-called "snap ring," "Seeger circlip ring" or the like and optionally by means of an intermediate piece or clamping element. As a result, the exact radial position of the centering bush 17 and thus of the coupling element 18 can be adapted to the actual dimensions or positions so that exact coupling is possible.

This improves operational reliability.

Fig. 6 schematically shows a hydraulic circuit diagram of a section of the hydraulic system of the mobile working machine 1 according to the invention. Fig. 6 illustrates that it is a common hydraulic cylinder 21 for the two adjustable locking bars/pistons 13. This means that a common cylinder housing 20 guides/comprises the two oppositely arranged pistons 13. On both opposite sides, the corresponding piston 13 is thus locked in the bore 12 of the corresponding receptacle 10 of the working device 2. The hydraulic fluid is advantageously guided through recesses or bores of the piston 13 within the locking bar element/piston 13 to the end face or the outer end of the piston 13 toward the corresponding valve or check valve.

For pressurization, two connections X, Y are shown in Fig. 6, wherein the

17 EP3 862 490 hydraulic fluid can flow from the connections Y and X via advantageous valves, in particular 2/2-way valves A, C, in each case through an opening of the cylinder housing 20 to the corresponding adjustable piston 13 and within the latter to a check valve, and thus as required to the working tool 2 or its actuators/cylinders 3.

Inthe present case, the two piston/locking bar elements 13 are adjusted by means of pressurization, for example from the connection X via an optional pressure accumulator F and an advantageous valve B, in particular a 2/2-way valve, and preferably via a pressure limiting element D, in particular a pressure shut-off valve, to the center/intermediate space or into the central region of the cylinder housing 20, i.e., into the intermediate space between the two pistons 13 arranged opposite one another and rotating in opposite directions. When the intermediate space is pressurized, the two pistons 13 move up to their respective stop (see Fig. 3, 4).

Two advantageous sensors 31 or position sensors 31 detect the position or the end position of the respective piston/locking bar 13 so that an (electrical) signal is advantageously generated or the locking is detected and transmitted to the driver and/or an advantageous (electrical) control unit and can optionally be signaled/displayed. This improves the operational reliability of the system.

The pressure accumulator F is also used in particular to damp the coupling process in an advantageous manner and to absorb any excess oil when the oil volume in the components is, for example, heated, in particular during the use or operation of so-called "permanent oil consumers" such as snow blowers, brooms or the like.

The pressure limiting element D, in particular the pressure shut-off valve, ensures that the piston(s) 13 ensures locking not at a maximum system pressure of, for example, approximately 200 bar, but, for example, (adjustably) at a permanent pressure of about 20 bar. This saves power and protects the components. In addition, the hydraulic length compensation can also be realized in an advantageous manner.

The unlocking or retracting of the piston/locking bar 13 takes place in that the chambers 27 arranged at the ends are advantageously pressurized via the connection Y. A safety system is preferably provided, which achieves/realizes that

18 EP3 862 490 the coupling or locking of the tool holding device 9 can be realized only when the hydraulic lines which are located inside the piston 13 are disconnected. This means that the zero or minimum pressure is within the pistons 13, but for movement or adjustment, the intermediate chamber/space between the two opposing pistons 13 for moving/locking. The same is likewise realized in an advantageous manner during the retraction or unlocking of the pistons/locking bars 13 with respect to the chambers 27. In this case, it is advantageous that the sensors 31 can detect the position of the piston/locking bar or the signal thereof can advantageously be used for this purpose.

In addition, according to the invention, a second switch/pushbutton 30 is present in the driver's cab or for the driver next to the operating element 8 or joystick 8, which switch/pushbutton is located far away from the operating element 8. The control unit or controller is thus designed such that both the switch/pushbutton 30 must be actuated and a switch/pushbutton/locking bar of the operating element 8 must also be actuated in order to allow the piston/locking bar 13 to be moved, preferably both during locking/extending and during unlocking/retracting of the piston(s)/bolt(s) 13. This increases the operational reliability of the mobile working machine 1 or the coupling and uncoupling of the working tool 2 and increases the service life of the (hydraulic) components.

19 EP3 862 490

List of reference signs 1 wheel loader 2 grab bucket 3 hydraulic cylinder 4 drive vehicle 5 lifting arm 6 steering system 7 driver's seat 8 operating element 9 tool holding device 10 receptacle 11 bolt 12 bore 13 locking bar/piston 14 transmission device 15 opening 16 fixing bush 17 centering bush 18 coupling element 19 coupling element 20 cylinder housing

20 EP3 862 490 21 hydraulic cylinder 22 dirt 23 — dirt duct 24 ring duct 25 stop 26 shoulder 27 spacing 28 spacing 29 play switch 31 sensor

Claims

1 EP3 862 490 MOBILE MACHINE EQUIPPED WITH A TOOL HOLDER FOR HOLDING THE TOOL PATENT CLAIMS

1. A mobile work machine (1), especially a wheel loader (1), a telescopic loader, — an excavator, a tractor or the like, which has a vehicle chassis with a detachably connectable tool (2) and which has a drive unit for at least one drive element, e.g. a drive wheel and/ or for using the drive device of a tracked vehicle, in which case at least one tool holding device (9) is provided to hold the releasably connectable tool (2); wherein the tool holding device (9) comprises at least one locking unit (21) — for releasably locking the tool (2), and at least one power transmission unit (18, 19) for transferring power for the tool (2); whereby the locking unit (21) has at least a first locking bar element (13) which is adjustable along the first adjustment path between the opening position and the locking position; whereby the first locking bar element (13) is in the locking position at least partially placed in at least the first receiving device (12, 14) of the tool (2); wherein the power transmission unit (18, 19) has at least a first transmission element (19) which is adjustable along a second adjustment path between the release position and the transmission position; whereby the first transfer element (19) is at least partially connected to the first transfer device (18) of the tool (2) in the transfer position; whereby the first receiving device (12, 14) of the tool (2) and/or the first transfer device (18) of the tool (2) has at least the first dirt opening (15, 23) and/or the first dirt channel (15, 23) for dirt (22) to remove and/or move through; whereby at least one hydraulic unit is provided, which comprises at least one hydraulic fluid and/or one hydraulic oil; where in particular the hydraulic unit comprises at least the first adjustable piston (13) in the hydraulic cylinder (21) and/or power transmission unit (19), characterized in that the first locking rod element (13) of the locking unit (21) and/or the first piston (13) of the hydraulic cylinder (21) is configured as a dirt removal element (13) for removing dirt (22) at least partially from the first receiving device (12) of the tool (2) and/or from the first transfer device (18) of the tool (2).

2. Work machine according to claim 1, characterized in that at least one position sensor (31) is arranged to detect the end position of at least the piston (13)

2 EP3 862 490 in the area and/or for detecting the first locking rod element (13) in the opening position, and/or that a first activation element (8, 30) is arranged to activate the first locking rod element (13) and/or piston (13) of the locking unit (21).

3. A work machine according to one of the preceding claims, characterized in that the hydraulic unit has at least one pressure valve (D) for reducing the pressure of the hydraulic unit and a second activation element (8, 30) for activating the pressure reduction valve (D), in which case the control unit is configured so that the first locking rod element (13) is to be activated in the unlocking position when the second = activation element (8, 30) is activated.

4. Work machine according to claim 3, characterized in that the first activation element (8, 30) and the second activation element (8, 30) are configured as separate switches (8, 30) for two-handed use, whereby the first activation element/switch (8, 30) and a switch gap is provided between the second — activation element/switch (8, 30).

5. Work machine according to claim 1, characterized in that at least one length compensation unit is arranged to compensate for length differences along the second adjustment path.

6. Work machine according to claim 5, characterized in that at least the length compensation unit is configured as at least a hydraulic length compensation unit (21) with hydraulic fluid, in particular hydraulic oil, and/or the first piston (13) which is adjustable in the hydraulic cylinder (21), whereby a pressure limiting valve is provided in particular (D) to limit pressure.

7. A work machine according to one of the preceding claims, characterized in that the first transfer element (19) is at least partially placed in the first locking bar element (13) of the locking unit (21) and/or that the first adjustable locking bar element (13) and/or the first adjustable transfer element (19) is at least partially placed inside the hydraulic cylinder (21) and/or that the first adjustment part coincides with the second adjustment path.

3 EP3 862 490

8. A work machine according to one of the preceding claims, characterized in that the first adjustable locking bar element (13) and/or the first adjustable transfer element (19) and/or the piston (13) has at least one front end surface (25) which is directed transversely to the first/second — relative to the adjustment path, and that at least one axial sealing element (25) is placed on the front end surface (25) to seal the transfer of hydraulic fluid and/or hydraulic oil.

9. A work machine according to one of the preceding claims, characterized in that at least the first support element (10) for supporting the tool (2) — comprises at least a first receiving opening (12) for the first locking bar element, and/or that the hydraulic cylinder (21) has at least a first end surface which is directed transversely to the first/second adjustment path.

10. A work machine according to one of the preceding claims, — characterized in that in the locking position of the first locking rod element (13) there is a first distance (28) between the first support element (10) and the first end surface of the hydraulic cylinder (21).

11. A work machine according to one of claims or 6, characterized in that the length compensation unit and/or the first piston (13) has at least a first detent surface (26) to stop and/or limit the impact movement, where in particular the first detent surface (26) is configured as a front end surface.

12. A work machine according to one of the preceding claims, characterized in that the first receiving device (14) and/or the first transfer device (18) of the tool (2) has at least one second detent surface for stopping the piston (13) and/or the first detent surface of the length compensation unit.

13. A work machine according to one of the preceding claims, characterized in that the first dirt opening (15) and/or the first dirt channel (23) is at least partially positioned in the vertical direction of the first transfer element (18) and/or the first

4 EP3 862 490 below the first piston (13) of the locking rod element (13) and/or the hydraulic cylinder (21).