EP0472115A1 - Quick coupler - Google Patents

Abstract

A quick coupler for fastening tools to the boom of a machine, in particular a shovel (1) to an excavator boom, one of the parts to be connected having at least two claws (3) with claw lobes (5) orientated in parallel and offset relative to one another in the insertion direction as well as perpendicularly thereto, the other part having horizontally extending projections (7) which the claws (3) overlap from the same direction when the parts are connected, and one of the parts pivotably mounting a catch (15) which is pressed under spring loading (22) into a locking position against a stop (7) of the other part, in which locking position it locks at least one claw (3) with an engaged projection and from which it can be disengaged by means of a release device (16), is to be less adversely affected in function by tolerances and wear. To this end, the catch (15) is pressed in the locking position at the end against a chamfer (21) of the stop (21), which chamfer (21) is inclined in the locking direction (V) relative to the pivoting path (S) of the catch end (20) and intersects this pivoting path (S) - preferably at an acute angle - in the normal locking position. <IMAGE>

Description

The invention relates to a quick-change device according to the preamble of patent claim 1.

US Pat. No. 3,237,795 already shows a generic quick-change device in which the claws can either be attached to the tool or the boom and, accordingly, the projections can either be attached to the boom or the tool. The claws are designed as right-angled hooks which overlap a correspondingly shaped upper edge or a hook section of a fastening plate forming the projections. The mounting plate supports a pawl which is pressed for locking under spring pretension over a claw which engages over the hook-shaped section of the plate. In the known device, the boom can be connected to the tool in a single vertical engagement movement after correct height and lateral alignment and horizontal positioning. However, due to the short side stop surfaces and the right-angled claw formation, a very precise alignment is required before engaging. Misalignments cause considerable wear on sections moving into one another during insertion attempts, so that, over time, a considerable splicing play occurs between the connecting parts beyond the tolerance play. In addition, the tool works under load in its attachment, so that the mounting game increases quickly. This can also lead to signs of wear or even overloading the latch for mutual locking, up to the point of unusability of the entire quick-change device.

From DE-OS 31 02 250 a device for automatically holding tools, in particular for excavators, loading vehicles and other earth moving machines is known, in which a cantilever-mounted tool carrier also has claws which engage with dowels in recesses or holes. The tool carrier also stores a pawl, which can be moved under spring tension behind a stop of the tool. When connecting the tool holder and tool, it is problematic that all dowel pins must be correctly aligned with their assigned holes. In this quick-change device, the pretensioned pawl slides when the parts are connected to a tool rear wall with a stop protruding therefrom, whereby a guiding function of the rear wall is impaired. A play of the dowel pins in the holes, which results anyway as a result of manufacturing tolerances and use, is further reinforced by their improper insertion. This device, too, can therefore quickly become unusable, to which a high tool load contributes.

DE-PS 27 34 972 discloses a device for connecting standard interchangeable installation tools, in which the tool must first be lifted into the claws of an interchangeable frame which are open at the top with attachment bolts. Then the tool can be inserted into the laterally opened lower claws of the removable frame with attaching tool lower bolts.

Finally, the lower claws can be closed by pivoting pawls by means of a pawl operating lever. In this device, not only is the connection of the tool to the interchangeable frame complex, but also an increased load on the pawl is given because the attachment tool engages the attachment pin on the attachment arm on the latter. This can lead to a particularly high level of play in the pins in the claws and to premature failure of the connection.

Based on this, the object of the invention is to create an improved quick-change device of the type mentioned, the function of which is less affected by manufacturing tolerances and wear on the components to be connected to one another. Rather, the device is intended to enable a rigid connection of the two parts over a long period of time even under harsh operating conditions. In addition, the connection of tool holder and tool should be simplified.

To achieve this object, the characterizing features of claim 1 are provided in a generic device.

In a quick-change device according to the invention, the pawl, which is pivotably mounted on one of the parts, is pressed in a conventional manner against the stop of the other of the parts when the parts are connected. As long as there is no wear, the pawl end reaches the normal locking position determined by finished tolerances, which is cut at an acute angle by a bevel of the stop, which is inclined in the locking direction to the swivel path of the pawl end. In the normal locking position, the pretensioning of the pawl causes the pawl end to be pinched slightly, thereby securing it in its position. However, the chamfer also ensures that the pawl end secures the components to be connected to one another in a position with claws firmly pressed against the projections by the pawl end assuming a locking position on the chamfer outside the normal locking position. This counteracts a work of the tool in the device under load, which a fastener enlargement of the game up to the failure of the connection can result. In addition, the bevel enables the tool and tool holder to be pressed into their locking position by means of a pawl actuation, which simplifies the connection process.

In an advantageous embodiment of the invention, the claw mouths widen towards the claw opening, thereby making it easier to connect to the projections with largely no impact. This also counteracts wear on the connecting elements.

According to an alternative solution or a further embodiment, the projections are formed by cylindrical rods supported on the other part by means of bearing blocks, and the claw jaws are rounded off correspondingly to the rods. This favors the transmission of force between the tool and the boom, so that the device is only subjected to slight deformations under load and operational wear is counteracted. In addition, the pedestals act as lateral guides for the claws that facilitate the connection process. It is advantageous that by inserting a pair of claws between an associated pair of pedestals, the other pair of claws can be aligned with the associated pair of pedestals. According to a further development, the lateral alignment of the tool and the tool carrier is further favored in that two bearing blocks offset in the insertion direction are parts of a common bearing plate.

The rods preferably carry conical disks for guiding the claws laterally when the rods are inserted, which promote simple, shock-free and wear-resistant insertion.

If one part supports the pawl and the bevel is formed on a rod of the other part on the side facing the claw mouth in the case of an overlapping claw, the rod is used in a constructional simplification both as a holder and as a tolerance and wear-compensating stop and as a locking part. A contact surface of one part preferably extends between the claws parallel to the direction of insertion and a counter-contact surface of the other part for guiding the contact surface between the projections. When connecting the tool and the boom, the contact surface then only has to be pressed against the counter contact surface, whereupon the parts can be pushed together in the insertion direction simply and with little impact and wear, without both rods having to be visible to an operator.

The bars are supported by two lateral bearing blocks for a favorable transmission of torsional moments. This also counteracts wear caused by working the connection under operational stress. Each rod preferably also has a central bearing block for further stabilization. For play-free transmission of torsional moments, two laterally offset claw jaws that are aligned with one another can overlap a projection.

In order to increase the rigidity of the construction, the claws of the quick-change device can be formed in parallel side walls of a box-like support with a rear wall supporting the side walls against one another and possibly further transverse walls. Such a carrier is dimensionally stable even with large tool loads. The side walls between the claws preferably hold a shaft for supporting the pawl, so that high locking forces are dissipated in the dimensionally stable carrier. Advantageously, at least one compression spring can be supported for locking between the pawl and the rear wall. Furthermore, the rear wall can have a passage opening for an actuating end of the pawl, which e.g. can be operated hydraulically, pneumatically or mechanically.

According to a practical development, a hydraulic cylinder can act on the actuating arm of the pawl. When the hydraulic cylinder engages the actuating arm in a box-like carrier without a through opening, the actuating devices are largely protected against disruptive environmental influences.

According to a further development, the hydraulic cylinder is connected to the actuating arm and has a hydraulic control which can hold the pawl in the locking position. This locking mechanism is intended to prevent the latch from being unintentionally unlocked by objects that have got between the tool and the tool holder. The connection of the hydraulic cylinder to the actuating arm is necessary in order to be able to both engage it and hold it in the locking position. The hydraulic cylinder can be a double-acting cylinder, which is controlled by means of a four / three-way valve. In the locked position, the feed lines of the cylinder are separated from the hydraulic pump or hydraulic tank. To connect the tool and the tool carrier, the valve is switched so that it connects the two feed lines of the cylinder to one another and, if necessary, to the hydraulic tank (if a differential cylinder requires fluid compensation). In a third position of the valve, one feed line of the cylinder is connected to the pump and the other to the hydraulic tank to unlock the pawl.

Finally, an advantageous embodiment device provided that the boom of the working machine has the claws and the tool has the projections. The structurally simpler parts of the quick-change device are then arranged on the interchangeable tools. In this case, the structurally complex pawl is advantageously to be mounted on the boom, which also simplifies its operation.

• Fig. 1 Träger einer Schnellwechselvorrichtung mit einem daran befestigten Löffel in Seitenansicht;
• Fig. 2 dieselbe Schnellwechselvorrichtung in einem vergrößerten Teilschnitt um die Klinke;
• Fig. 3 Träger derselben Schnellwechselvorrichtung vor dem Einbau einer Klinke in Seitenansicht;
• Fig. 4 denselben Träger in der Hinteransicht;
• Fig. 5 denselben Träger in der Vorderansicht;
• Fig. 6 eine vergrößerte Darstellung der Einzelheit VI gemäß Fig. 3;
• Fig. 7 eine vergrößerte Darstellung der Einzelheit VII gemäß Fig. 3;
• Fig. 8 Löffel derselben Schnellwechselvorrichtung in der Hinteransicht;
• Fig. 9 den oberen Lagerbock desselben Löffels in vergrößerter Seitenansicht;
• Fig. 10 den unteren Lagerbock desselben Löffels in vergrößerter Seitenansicht;
• Fig. 11 eine Kegelscheibe desselben Löffels in vergrößerter Hinteransicht;
• Fig. 12 eine andere Schnellwechselvorrichtung mit mittigen Lagerböcken an werkzeugfesten Stangen in einem Querschnitt.

Further details and advantages of the subject matter of the invention will become apparent from the following description of the accompanying drawings, which show two preferred embodiments of a quick-change device according to the invention. The drawings show:

• Figure 1 Carrier of a quick-change device with a spoon attached to it in side view.
• Figure 2 shows the same quick-change device in an enlarged partial section around the pawl.
• Fig. 3 carrier of the same quick-change device before installing a pawl in side view;
• Figure 4 shows the same carrier in the rear view.
• Figure 5 shows the same carrier in front view.
• Fig. 6 is an enlarged view of detail VI of FIG. 3;
• Fig. 7 is an enlarged view of detail VII of FIG. 3;
• Fig. 8 spoons of the same quick-change device in the rear view;
• 9 shows the upper bearing block of the same spoon in an enlarged side view;
• Figure 10 shows the lower bracket of the same spoon in an enlarged side view.
• 11 shows a conical disk of the same spoon in an enlarged rear view;
• Fig. 12 shows another quick-change device with central bearing blocks on tool-fixed rods in a cross section.

In the quick-change device according to FIG. 1, a bucket 1 is connected to a carrier 2, which in turn can be directed to a boom of an excavator, not shown, by means of two axes. The carrier 2 has upper claws 3 and lower claws 4, which are staggered one behind the other perpendicular to the plane of the drawing. The claw jaws 5 of the upper claws 3 are aligned parallel to the claw jaws 6 of the lower claws 4.

An upper rod 7 is inserted into the two upper claws 3 and a lower rod 8 into the two lower claws 4. The rods 7, 8 are mounted laterally on the spoon 1 by means of upper bearing blocks 9 and lower bearing blocks 10.

The upper claws 3 are arranged offset in the direction of insertion E and perpendicularly with respect to the lower claws 4, so that both rods 7, 8 can be guided into one another in a single linear movement of the carrier 2 against the direction of insertion E when the tray 1 and carrier 2 are correctly aligned . The pre-alignment of the carrier 2 on the spoon 1 is facilitated by two lateral contact surfaces 11 of the carrier 2 and a counter-contact surface 12 of the spoon 1, which extend exactly in the insertion direction E lying one on top of the other.

Details of the locking of the quick-change device with rods 7, 8 inserted into the claws 3, 4 can be seen in FIG. 2. The carrier 2 has a shaft 13 inside, which supports at least one eye 14 of a pawl 15 which is bent at right angles to the eye 14. An actuating arm 16 of the pawl 15 protrudes approximately perpendicular to the contact surface 11 from a through opening 17 of a welded-on rear wall 18 of the carrier 2. A pneumatic actuator can attack there.

A working arm 19 of the pawl 15 extends approximately parallel to the contact surface 11, its pawl end 20 being bent over the contact surface.

The pawl end 20 abuts in the normal locking position shown against a bevel 21 of the upper rod 7. In this position, the pawl 15 is pressed by two compression springs 22, which are supported on the one hand on this and on the other hand on the rear wall 18. Finishing tolerances have already been compensated for here.

The pawl end 20 describes a pivot path S about the axis 13, which is cut at an acute angle by the bevel 21 in the locking direction V. If the mutual position of the spoon 1 and the carrier 2 changes as a result of wear, the pawl end 20 looks for a different locking position on the bevel 21, in which a safe and play-free connection between the spoon 1 and the carrier 2 is provided. Due to their parallel alignment, the claws absorb 3 and 4 moments due to the tearing and breakaway forces of the bucket 1. The pawl 15 only needs to support compressive forces that are directed approximately counter to the direction of insertion E.

3 to 5 show, the claws 3, 4 are formed in two parallel side walls 23, 24 of the carrier 2, which also have bores 25, 26 for receiving the axis 13. The rear wall 18 connects the side walls 23, 24 and is provided with blind bores 27, 28 for holding the compression springs 22. The carrier 2 is further stabilized by an upper transverse wall 29 between the side walls 23, 24. Since the through opening 17 almost over the entire width of the Extending rear wall 18, high locking or unlocking forces can be introduced.

6 and 7 show, the claw jaws 5, 6 of the upper and lower claws 3, 4 are extended towards the claw opening, whereby the insertion of the rods 7, 8 is facilitated. For the same reasons, the adjacent end regions of the side walls 23, 24 are rounded on the outside. Above the central plane of the rods 7, 8, however, the inner contour of the claw jaws 5, 6 corresponds to the outer contour of the rods, as a result of which a tight fit and a uniform transfer of force are ensured.

8 and 9 can be seen better how the rods 7, 8 are attached to the spoon 1 by means of bearing blocks 9, 10 on both sides. The upper bearing blocks 9 are located on an inclined surface 30 of the spoon 1, so that the rear wall of the spoon can form the flat counter-contact surface 12 for the contact surface of the carrier. The rods 7, 8 can be connected to the bearing blocks 9, 10 and possibly also the bearing blocks to the spoon 1 by welding or brazing.

The upper bearing blocks 9 and the lower bearing blocks 10 are each spaced further apart from one another than the upper claws 3 and the lower claws 4, so that the claws are guided laterally by the bearing blocks. In order to facilitate the insertion of the rods 7, 8 into the claws 3, 4, the rods carry conical disks 31 which bear with their large diameter on the bearing blocks 9, 10 and on which the claws 3, 4 can slide into their correct fastening position. The connection between the conical disks 31 and the rods 7, 8 or the bearing blocks 9, 10 can also be made by welding or brazing.

In the quick-change device according to FIG. 12, reference numerals are provided as in the device according to FIGS. 1 to 11, insofar as the designated parts are structurally and functionally comparable. In this respect, reference is made to the above statements. Only the deviations are discussed below.

The upper and lower rods 7, 8 each have an additional, central bearing block 32, which is firmly connected to the spoon 1 and increases the rigidity of the construction. The pawl 15 is provided starting from the pawl end 20 with a longitudinal slot 33 which receives the central bearing block 32. In addition to the upper transverse wall 29, a lower transverse wall 34 is provided below the actuating arm 16 of the pawl 15, which connects the side walls 23, 24 to one another and also contributes to stabilizing the construction. A rear wall is therefore unnecessary.

Claims (17)

1. Quick-change device for connecting tools to the boom of a working machine, in particular a bucket (1) with an excavator boom, one of the parts to be connected has at least two claws (3, 4) with parallel alignment and in the insertion direction (E) and perpendicular to one another has offset claw jaws (5, 6), the other of the parts has horizontally extended projections (7, 8) which, when the parts are connected, are overlapped by the claws (3, 4) from the same direction, and one of the parts has a pawl (15 ) pivotally mounted, which is pressed under pretension into a locking position against a stop of the other of the parts, in which it locks at least one claw (3) with an indented projection (7) in the claws (3, 4) and from which it is by means of a release device (16) can be moved, characterized in that the pawl presses in the locking position at the end against a bevel (21) of the stop (7) which is inclined in the locking direction (V) to the swivel path (S) of the pawl end (20) and cuts it in the normal locking position - preferably at an acute angle. 2. Device according to claim 1, characterized in that the claw mouths (5, 6) widen towards the claw opening. 3. Device according to the preamble of claim 1, in particular in connection with the characterizing features of claim 1 and / or claim 2, characterized in that the projections (7, 8) by means of bearing blocks (9, 10, 32) supported on the other part , cylindrical rods (7, 8) are formed, and that the claw jaws (5, 6) are rounded according to the rods. 4. The device according to claim 3, characterized in that in each case two bearing blocks offset in the insertion direction are parts of a common bearing plate. 5. Apparatus according to claim 3 or 4, characterized in that the rods (7, 8) conical washers (31) for laterally guiding the claws (3, 4) when inserting the rods. 6. Device according to one of claims 3 to 5, characterized in that the one part supports the pawl (15) and that the chamfer supply (21) is formed on a rod (7) of the other part on the side facing the claw mouth (5, 6) in the case of an overlapping claw (3, 4). 7. Device according to one of claims 1 to 6, characterized in that between the claws (3, 4) parallel to the insertion direction (E) has a contact surface (11) of one part and between the projections (7, 8) a counter-contact surface ( 12) of the other part for guiding the contact surface. 8. Device according to one of claims 1 to 7, characterized in that the rods (7, 8) are each supported by two lateral bearing blocks (9, 10). 9. Device according to one of claims 3 to 8, characterized in that each rod (7, 8) has a central bearing block (32). 10. Device according to one of claims 1 to 9, characterized in that two laterally offset and mutually aligned claw jaws (5, 6) overlap a projection (7, 8). 11. The device according to one of claims 1 to 10, characterized in that the claws (3, 4) in parallel side walls (23, 24) of a box-like carrier (2) with a back wall supporting the side walls against each other (18) and possibly further Cross walls (29, 34) are formed between the side walls. 12. The apparatus according to claim 11, characterized in that the side walls (23, 24) between the claws (3, 4) hold a shaft (13) for supporting the pawl (15). 13. The apparatus of claim 11 or 12, characterized in that at least one compression spring (22) between the pawl (15) and rear wall (18) is supported. 14. Device according to one of claims 11 to 13, characterized in that the rear wall (18) has a through opening (17) for an actuating arm (16) of the pawl (15). 15. The device according to one of claims 1 to 14, characterized in that a hydraulic cylinder acts on the actuating arm of the pawl. 16. The apparatus according to claim 15, characterized in that the hydraulic cylinder is connected to the actuating arm and has a hydraulic control which can hold the pawl in the locking position. 17. The device according to one of claims 1 to 16, characterized in that the boom of the working machine has the claws (3, 4) and the tool (1) has the projections (7, 8).

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