DK2378006T3

DK2378006T3 - Quick-change device with an active clamping support for attaching a tool to a working machine

Info

Publication number: DK2378006T3
Application number: DK11161157.0T
Authority: DK
Inventors: Leone Laurito; Peter Lehnhoff; Jan Rotard
Original assignee: Lehnhoff Hartstahl Gmbh & Co Kg
Priority date: 2010-04-16
Filing date: 2011-04-05
Publication date: 2017-03-13
Also published as: ES2616785T3; PL2378006T3; EP2378006B1; DE102010016491B4; HUE033323T2; EP2378006A1; DE102010016491A1

Description

A quick-change device with an active tensioning support for coupling a tool to a work machine

The invention relates to a quick-change device for coupling a tool to a work machine, of the type specified in the preamble of claim 1.

Quick-change devices of this kind are well known for use with earth-moving machines such as excavators in which case they enable fast and easy change of various hydraulic tools such as screening buckets, tilt buckets, hydraulic hammers and the like. A quick-change device of the generic type is disclosed in WO 91/01414. The disclosed quick-change device has a quick-change unit associated with the excavator and which comprises a pivoting and locking device, and an adapter associated with the tool. Besides means for establishing a mechanical connection between the quick-change unit and the adapter, the quick-change device moreover includes an automatic coupler comprising a coupler part on the quick-change unit side and a coupler part on the adapter side. The coupler acts to automatically couple a hydraulic circuit on the excavator side to a hydraulic circuit on the tool side when the two coupler parts are pivoted together. This will not require any further action by the machine operator such as exiting the excavator cab and manually coupling the excavator-side hydraulic circuit to the tool-side hydraulic circuit.

Another quick-change device of the generic type is described in DE 101 59 417 A1. This quick-change device is characterized, amongst other things, in that the coupling block on the quick-change unit side and/or the coupling block on the adapter side are movably mounted.

Further measures for minimizing leakage caused by the spreading forces acting between the two coupling valves in the coupled state, so as to prevent leakage of hydraulic fluid and consequential ground contamination, are not disclosed in the above mentioned documents.

Another quick-change device having a tensioning support which is movably mounted in the coupling block is disclosed both in EP 1 473 415 A1 and in FR 2 886 372. A disadvantage of this device is that it requires an additional controller as well as additional hydraulic lines and valves for moving the tensioning support.

It is the object of the invention to further develop a quick-change device for coupling a tool to a work machine, of the type specified in the preamble of claim 1, in such a manner that the resulting coupling is reliable in operation.

This object is accomplished by the characterizing features of claim 1 in combination with the features of its preamble.

The subclaims define advantageous embodiments of the invention.

In a known manner, the quick-change device comprises a quick-change unit attached to a work machine and an adapter attached to a tool, as well as a locking device which acts between the quick-change unit and the adapter so as to mechanically couple the work machine to the tool. For a hydraulic connection between the work machine and the tool, the quick-change device furthermore includes a hydraulic coupling. Said hydraulic coupling in turn comprises a hydraulic block on the quick-change unit side, with hydraulic lines and corresponding hydraulic coupling valves, as well as a coupling block on the adapter side, with hydraulic lines and coupling valves. Moreover, the quick-change unit side coupling block and/or the adapter side hydraulic block is elastically mounted in its surrounding housing, i.e. in the quick-change unit side housing or in the adapter side housing, resp.

In accordance with the invention, the quick-change unit side coupling block has a tensioning support in the form of a hollow body in at least one of its hydraulic lines, which tensioning support is disposed downstream of the coupling valve, as viewed in the direction of flow S, partially extends into the hydraulic line and is mounted therein so as to be slidable in the direction of flow S. The portion of the tensioning support which is inside the hydraulic line has a pressure application surface, and the portion which extends out of the hydraulic line has a contact surface formed thereon which rests against the surrounding housing.

As a result of the hydraulic fluid flowing through the coupling valves in the coupled state and the pressure application surface provided on the tensioning support, the tensioning support of the invention will act as a hydraulic cylinder and will be displaced in the direction of flow S, and its contact surface will be tensioned to the surrounding housing. Due to the fact that the quick-change unit side coupling block and/or the adapter side coupling block are elastically mounted, this will cause the two coupling blocks to be pressed upon each other, thus clearly reducing the danger of leakage.

Another advantage of the tensioning support according to the invention is that it will be “automatically” active in the coupled state, i.e. during the passage of hydraulic fluid, due to its portion which is located inside the hydraulic line and is provided with the pressure application surface.

Another advantage of the present invention is that no further attachment, for example lateral attachment, will be required anymore, because of the tensioning provided between the quick-change unit side coupling block and the adapter side coupling block by means of the tensioning support.

As pointed out above, the portion of the tensioning support that is inside the hydraulic line has a pressure application surface. In order to ensure sufficient flow of hydraulic fluid, the ring-shaped front face - ring surface - of the tensioning support constitutes the pressure application surface.

Preferably, the portion of the tensioning support which extends outside the hydraulic line includes a flange-like projection with a contact surface that faces the housing. The increase in diameter of the tensioning support due to the flange-like projection is an advantageous way of ensuring “full” contact between the tensioning support and the housing. Moreover, this design prevents the tensioning support from “slipping inside”, i.e. the tensioning support is positioned in a way that makes it secure from loss.

In order to prevent leakage of hydraulic fluid, a seal, preferably an O-ring seal, is provided between the hydraulic line and the tensioning support.

Preferably, the coupling valves are active coupling valves. The term active coupling valves relates to the fact that the coupling valves will not necessarily open when the coupling blocks are connected, but will be actively opened or closed when energy is supplied. The use of active coupling valves has the advantage that their design requires little space and yet ensures a high flow rate.

It is also conceivable to provide the coupling valves in the form of short-lift valves which will merely require a lift of 1 to 5 mm, for example, to operate the valve. This is advantageous in that it allows a compact design of the coupling valves, due to the short valve lifts.

In a particular advantageous embodiment of the invention, the quick-change unit side coupling block and/or the adapter side coupling block is elastically mounted on its surrounding housing by means of an elastic pressing-off element. The use of an elastic pressing-off element proves particularly advantageous since it constitutes an inexpensive and low-maintenance mounting which moreover also has a sealing function.

Additional advantages, features and possible applications of the present invention may be gathered from the description which follows, in which reference is made to the embodiment illustrated in the drawings.

The invention is described in more detail below with reference to an embodiment illustrated in the drawings.

Throughout the description, the claims, the abstract and the drawings, those terms and associated reference signs are used as are listed in the list of reference signs which follows after the description. In the drawings,

Fig. 1 is a perspective view of a quick-change device having a quick-change unit and an adapter, in which the quick-change unit is connected to an excavator and the adapter is connected to a screening bucket;

Fig. 2 is an enlarged sectional view of the quick-change device of Fig. 1 having an integrated tensioning support, and

Fig. 3 is a view of an enlarged detail of Fig. 2.

In order to avoid repetitions, identical reference signs are used to designate identical component parts in the description below as well as in the drawings, as long as no further differentiation is required.

Fig. 1 is a view of a quick-change device 10 which is used to detachably mount a screening bucket 12 on an excavator 14. For the sake of clarity, this view merely shows the boom of the excavator 14.

The quick-change device 10 comprises a quick-change unit 16 connected to the boom and an adapter 18 provided on the screening bucket 12. A locking device which is not shown or described here can be used to mechanically couple the quick-change unit 16 to the adapter 18 in a known manner, thus allowing fast and simple changing of tools, for example releasing the screening bucket 12 shown and installing a hydraulic hammer or the like.

For connecting the tool, for example the screening bucket 12 shown, to the hydraulic system of the excavator, the quick-change device 10 moreover includes a hydraulic coupling which is generally defined by the reference number 20. The hydraulic coupling 20 in turn comprises a coupling block 20a on the side of the quick-change unit and a coupling block 20b on the side of the adapter.

As can be seen from Fig. 2, the coupling block 20a on the side of the quick-change unit has hydraulic lines 22a, 24a and 26a as well as associated coupling valves 28a, 30a and 32a. Similarly, the coupling block 20b on the side of the adapter has hydraulic lines 22b, 24b and 26b with associated coupling valves 28b, 30b and 32b. As can further be seen in Fig. 2, the coupling valves 28a, 28b; 30a, 30b; 32a, 32b are perfectly aligned above one another in the coupled state so as to ensure the passage of hydraulic fluid through the hydraulic lines 22a, 22b; 24a, 24b and 26a, 26b from the quick-change unit 16 to the adapter 18 and vice versa.

The tensioning support according to the invention can best be seen in Fig. 3. As is shown in Fig. 3, a tensioning support 34 is connected downstream of the coupling valve 30a, as viewed in the direction of flow S. Part of the tensioning support 34 which is designed as a hollow body extends into the hydraulic line 24a and is slidably mounted therein, as viewed in the direction of flow S. In order to prevent undesired leakage of hydraulic fluid between the outer circumferential surface of the tensioning support 34 and the inner circumferential surface of the hydraulic line, the tensioning support has a groove in its outer circumferential surface, which groove has a corresponding seal 36 inserted in it.

Moreover, the tensioning support has a ring-shaped pressure application surface 38 on its end facing the coupling valve. Outside the hydraulic line 24a, the tensioning support 34 has a flange-like projection 40. The flange-like projection 40 constitutes a contact surface 42 via which the tensioning support 34 is in contact with the surrounding housing 44.

When, in the coupled state, hydraulic fluid flows through the coupling valve 30a in a direction of flow S, some pressure will build on the pressure application surface 38 of the tensioning support 34. This means that the tensioning support 34 will be displaced in the direction of flow S in a manner comparable to a hydraulic piston. As a result, the contact surface 42 of the tensioning support 34 will become tensioned against the surrounding housing 44. The ensuing reaction will press the two coupling blocks onto each other and thus tension the two coupling blocks relative to each other.

For the sake of completeness, it is to be noted that the active piston surface on which the pressure prevailing in the valve acts is not restricted to the pressure application surface 38 but is the total surface of the diameter of the hydraulic line in which the tensioning support 34 is guided and which is sealed by the seal 36. This is actually the active surface which presses the two valve blocks onto each other.

List of Reference Signs 10 quick-change device 12 screening bucket 14 excavator 16 quick-change unit 18 adapter 20 coupling 20a quick-change unit side coupling block 20b adapter side coupling block 22a hydraulic line 22b hydraulic line 24a hydraulic line 24b hydraulic line 26a hydraulic line 26b hydraulic line 28a coupling valve 28b coupling valve 30a coupling valve 30b coupling valve 32a coupling valve 32b coupling valve 34 tensioning support 36 seal 38 pressure application surface 40 flange-like projection 42 contact surface 44 housing S direction of flow

Claims

A quick change device (10) for connecting a tool (12) to a working machine (14), comprising - a quick change switch (16) fixed to a working machine (14); an adapter (18) attached to the tool (12); - a locking device operable between the quick-release switch (16) and the adapter (18) for establishing a mechanical coupling between the working machine (14) and the tool (12); a hydraulic coupling (20) for establishing a hydraulic connection between a hydraulic system existing on the working machine (14) and a hydraulic system in the tool (12), wherein the hydraulic coupling (20) has a coupling block (20a) on the quick-change side with hydraulic lines (22a) , 24a, 26a) and coupling valves (28a, 30a, 32a) - quick-release coupling block - and a coupling block (20b) on the adapter side with hydraulic lines (22b, 24b, 26b) and coupling valves (28b, 30b, 32b) - adapter block - and at least one coupling block (20a, 20b) is resiliently mounted in its surrounding housing (44), wherein the coupling block (20a) on the quick-change side of at least one first hydraulic line (22a, 24a, 26a) of its hydraulic lines (22a, 24a, 26a) is seen in flow direction (S) from the coupling block (20b) on the adapter side to the coupling block (20a) on the quick-change side, the clamping support (34) arranged downstream of the coupling valves (28) is arranged as a hollow body. a, 30a, 32a) on the quick-change side, extending regionally into the first hydraulic line (22a, 24a, 26a) and in flow direction (S) is displaceable in the first hydraulic line (22a, 24a, 26a), characterized in that the clamping support (34) has a front side extending into the first hydraulic line (22a, 24a, 26a) and forming a pressure-engaging surface (38) and the clamping support (34) at its region extending out of the first hydraulic line (22a, 24a, 24b) exhibit an abutment surface (42) through which the clamping support (34) abuts against the surrounding housing (44) of the speed switch (16).

Quick change device (10) according to claim 1, characterized in that the pressure-engaging surface (38) is formed as an annular surface.

Quick change device (10) according to claim 1 or 2, characterized in that the clamping support (34) outside a first hydraulic line (22a, 24a, 26a) has a flange-like collar (40) on which the abutment surface (42) is formed.

Quick change device (10) according to one of the preceding claims, characterized in that a seal (36) is arranged between the first hydraulic line (22a, 24a, 26a) and the clamping support (34), in particular an O-ring seal.

Rapid switching device (10) according to one of the preceding claims, characterized in that the switching valves (28a, 30a, 32a; 28b, 30b, 32b) are active switching valves.

Quick change device (10) according to one of claims 1 to 4, characterized in that the valves (28a, 30a, 32a; 28b, 30b, 32b) are short-stroke valves.

Quick change device (10) according to one of the preceding claims, characterized in that the coupling block (20a, 20b) on the quick change side and / or on the adapter side is elastically mounted on its surrounding housing (44).