Quick-change device for excavators

Abstract

 A quick-change device (1) is disclosed for connecting implements to an excavator while simultaneously connecting hydraulic conduits, wherein the quick-change device has a main body (2) in which at least one locking component (9,10,11) is accommodated, wherein the main body (2) is confined or terminated at the sides by one-piece side plates (3,4), wherein the at least one locking component (9,10,11) extends and moves essentially parallel to the side plates. Furthermore, a quick-change device is disclosed for connecting implements to an excavator while simultaneously connecting hydraulic conduits, wherein the quick-change device has a main body in which at least one locking component is accommodated, wherein the main body is confined or terminated at the sides by one-piece side plates, wherein the at least one locking component extends and moves essentially parallel to the side plates, wherein the side portions, in an area near to the position where the at least one locking component exits or extends from the main body, respectively have a recess (15) for engagement with a corresponding bolt or projection on the implement.

Description

[0001] The invention generally relates to quick-change devices for attaching implements onto work machines while simultaneously connecting hydraulic conduits.

[0002] When operating excavators, it has become more and more common to change various implements e. g. back hoes, milling tools, hydraulic hammers or combination buckets. It is often necessary to change these implements several times a day, and this forces the driver either to attach or release the associated hydraulic hoses manually, or to use a quick-change device with an integrated or associated hydraulic hose coupler. This type of system is disclosed e. g. DE 692 10 405 T2, DE 102 00 836 A1 and WO 97/30231.

[0003] A disadvantage associated with these quick-change devices is, for example, the expensive construction of the quick-change devices and the type of locking mechanism. Moreover, there are often numerous hydraulic hoses which are to be attached, and this requires a corresponding number of hydraulic couplings. Besides a hydraulic fluid feed and outlet for the main function of the tool, it may well be necessary to provide corresponding control lines for additional secondary functions. A feed and an outlet are also required for operating (locking and unlocking) the quick-change device. Because of the large number of hydraulic hoses, there is increased risk of one of the hydraulic hoses becoming trapped or even sheared off between movable parts.

[0004] Particularly when using a hydraulic hammer, the quick-change device must apply great forces in order to attach the excavator boom or stick to the tool without any vibrations. Any play between the excavator boom or stick and the tool may result in the quick-change device becoming worn out and or its function becoming adversely effected. In this way, for example, the hydraulic couplings could become leaky because of slight relative movements between the excavator boom or stick and the tools. Conventional quick-change devices hook onto the tool at one end and caulk, wedge, or clamp the quick-change device to the tool by means of the locking components along the whole length of the quick-change device. In so doing, huge forces are applied so as to create an attachment free from play. These forces can lead to deformation of the quick-change device so that the locking components and/or the hydraulic couplings must be appropriately readjusted so as to maintain a reliable attachment.

[0005] In view of these problems of the prior art, the invention aims to overcome or avoid the disadvantages of the prior art, and to provide an optimised quick-change device.

[0006] A preferred embodiment of this invention is shown in the drawings and is described in greater detail, with reference to the drawings, in the following.

Fig. 1

is a perspective view of a quick-change device in accordance with this invention, wherein the locking components are partially extended;

Fig. 2

is a side view of the quick-change device in accordance with Fig. 1 with retracted locking components; and

Fig. 3

is a perspective front view of the quick-change device in accordance with fig. 1, wherein the locking components are partially extended.

[0007] The invention is explained hereinafter in more detail by referring to Figs. 1 to 3. The illustrated quick-change device 1 has a main body 2 which is confined or terminated at the sides by side portions, preferably by one-piece side plates 3, 4. The one-piece design means that the side plates 3, 4 are given increased stability and can be produced more easily in comparison with quick-change devices which have the lugs, for example, welded on for attachment to the excavator boom or stick.

[0008] In order to increase the stability further and to provide a seal between the tool and the quick-change device, reinforcement plates 5, 6 can be provided on the side plates 3, 4. The reinforcement plates 5, 6 can, for example, be welded onto the side plates 3, 4.

[0009] Holes 7 which pass through the side plates 3, 4, and, if necessary, through the reinforcement plates 5, 6, are provided for holding bearing bushings 8 for attachment to a excavator boom or stick. The holes 7 can also be provided at a later stage so that the otherwise finished quick-change device can be adapted to the situation of an existing excavator boom or stick.

[0010] In an excavator, it is often sufficient to have a single input flow (or port) and a single output flow (or port) for a proper hydraulic function of the tool or implement. In accordance with the invention, however, locking components with multiple couplings can also be used so that several hydraulic work functions are made possible. Preferably, three locking components 9, 10, 11 are provided; but it is also possible to provide more or less locking components. With three locking components, one locking component may provide an input port and another locking component may provide an output port. To this end, hydraulic couplings and corresponding feed conduits with a large diameter are provided so as to guarantee a high flow rate. For hydraulic functions with less demanding requirements with respect to flow rates of the hydraulic work fluid, several smaller hydraulic couplings with correspondingly smaller feed conduits can be combined in one single locking component, as shown in Figs. 1 and 3 for the central locking component 10.

[0011] The locking components 9, 10, 11 have an essentially cylindrical shape, and this simplifies their production as well as the maintenance of tolerances and the provision of corresponding bearings as compared to other shapes of locking components. Preferably, the locking components have a diameter of approx. 10 centimetres, thereby providing a small structural size in combination with reliable locking. On the outer end, the locking components preferably have a bevel 9a, 10a, 11 a which makes it easy to introduce the locking components into corresponding recesses in the tool (not shown) and which makes it possible to provide caulking wedging, or Clamping persistently free from play, in the recess for the tool. The locking components 9, 10, 11 extend and move essentially parallel to the side plates 3, 4.

[0012] Separate hydraulic couplings 12, 13, 14 are provided in the locking components 9, 10, 11 which may be fixedly, elastically or spring mounted. The hydraulic couplings can, for example, be screwed in, wherein preferably the corresponding screw socket is elastically mounted in the locking component by means of a rubber sleeve or gasket, or is spring mounted by means of a Belleville spring or a coil spring.

[0013] In accordance with the invention, the side plates 3, 4 respectively have on the rear lower end, in accordance with Figs. 1 and 3, or alternatively on the right hand side at the bottom, in accordance with fig. 2, a recess 15 for engagement with a corresponding bolt or projection on the tool. Moreover, the side plates 3, 4 have on the front end, in accordance with Figs. 1 and 3, or alternatively on the left hand side, in accordance with fig. 2, a hook-like projection 16 which defines a recess 17.

[0014] The recess 15 essentially serves to fix the tool and the quick-change device in a vertical direction as shown in the Figures. In the prior art, this type of recess will also transfer the large caulking or clamping forces in a horizontal direction.

[0015] In contrast to this, the horizontal caulking or clamping forces applied by the locking components 9, 10, 11 for locking are transferred by the recess 17 when a bolt or projection (not shown) provided on the tool engages with the recess 17. In this way, there is a considerably reduced horizontal distance between the points of contact for the high horizontal caulking or clamping forces between the quick-change device and the tool. Deformation of the quick-change device and play between the quick-change device and the tool can be reliably prevented by this structure.

[0016] A directional control valve (not shown) can be provided in the quick-change device 1. The directional control valve serves to switch over hydraulic conduits for less frequently used functions. For example, secondary functions of the tool are only rarely used, and the same hydraulic supply conduits can, thanks to the directional control valve, also be used for locking and unlocking the quick-change device, especially since the functions of the tool are never required at the same time during locking or unlocking of the quick-change device. In this way, the number of required hydraulic supply conduits may be reduced by two.

[0017] With the quick-change device 1 shown, the main supply conduits for the main functions are attached via correspondingly sized connections 18, 19 with the quick-change device or the couplings 12, 14 in the locking components 9, 11. Additional, preferably small supply conduits for the secondary functions or for the locking and unlocking of the quick-change device are connected to corresponding connections 20, 21. From the connections 20, 21 and via the directional control valve, either a connection can be made to the hydraulic couplings 13 in the locking component 10, or the operation cylinder(s) (not shown) for the locking components 9, 10, 11 can be operated.

[0018] The invention is also directed to work tools or implements for cooperation with the quick-change device.

[0019] In accordance with a preferred embodiment of the present invention, the connections 18-21 may be provided on a movable carriage which can move together with the locking components 9, 10, 11. The carriage covers and seals an elongate opening beneath the carriage and prevents dirt or debris from entering.

[0020] Preferably, the bearing bushings 8 are sized and arranged such that conduits connected to the connections 18-21 have sufficient clearance for passing by the excavator boom or stick and may also adapt to a tilting movement e. g. of a bucket.

[0021] Also, by using correspondingly sized bearing bushings 8 having a suitable axial length, excavator booms or sticks having various widths may be accommodated without having to change the basic construction of the quick-change device, in particular with regard to the main body or the side plates.

[0022] In another advantageous variation of the present invention, four or more locking members may be provided. Preferably, these four or more locking members are aligned side by side across the width of the main body of the quick-change device, thereby forming an array of locking members. Then, the outer locking members in the array may accommodate couplings having a relatively small diameter for handling a smaller flow rate, such as for secondary hydraulic functions of the implement, and the inner locking members of the array may accommodate couplings having a relatively larger diameter for handling a larger flow rate, such as for the primary hydraulic function of the implement. In fact, the diameter of the outer locking members accommodating the smaller diameter couplings may be even larger than the diameter of the inner locking members accommodating the larger diameter couplings, thereby providing outer locking members which are mechanically very robust and sturdy, whereas the inner locking members only play a minor role in the mechanical locking of the quick-change device and the implement. Since the highest forces are applied near the outer sides of the quick-change device, the strong outer locking members can withstand these high forces while keeping the overall dimensions of the locking members and of the quick-change device relatively small and compact. The absolute size of the locking members will, of course, also depend on the size of the hydraulic coupling accommodated therein. In this context, it is emphasized that it may be advantageous that the outer locking members be mechanically stronger than the inner locking members. Depending on the particular application, one may even consider to provide solid outer locking members without hydraulic couplings, and to provide only the inner locking members with hydraulic couplings of whatever size is required. In such a case, the inner locking members may be sized according to the mechanical and hydraulic requirements.

Claims

1. Quick-change device (1) for connecting implements to an excavator while simultaneously connecting hydraulic conduits,
said quick-change device (1) comprising a main body (2) in which at least one locking component (9, 10, 11) is accommodated,
wherein the main body (2) is confined or terminated at the sides by one-piece side plates (3, 4),
wherein the at least one locking component (9, 10, 11) extends and moves essentially parallel to the side plates (3, 4).

2. Quick-change device (1) in accordance with claim 1, wherein reinforcement plates (5, 6) are provided on the side plates (3, 4).

3. Quick-change device (1) in accordance with claim 2, wherein the reinforcement plates (5, 6) are welded onto the side plates (3, 4).

4. Quick-change device (1) in accordance with any of the preceding claims, wherein three locking components (9, 10, 11) are provided.

5. Quick-change device (1) for connecting implements to an excavator while simultaneously connecting hydraulic conduits,
said quick-change device (1) comprising a main body (2) in which at least one locking component (9, 10, 11) is accommodated,
wherein three locking components (9, 10, 11) are provided.

6. Quick-change device (1) in accordance with claim 4 or 5, wherein one locking component (9, 11) provides an input port and another locking component (9, 11) provides an output port, each having a corresponding hydraulic coupling (12, 14), and
wherein the third locking component (10) has several smaller hydraulic couplings (13).

7. Quick-change device (1) in accordance with any of the preceding claims, wherein the at least one locking component (9, 10, 11) has an essentially cylindrical shape.

8. Quick-change device (1) in accordance with any of the preceding claims, wherein the at least one locking component (9, 10, 11) has a bevel (9a, 10a, 11 a) on the outer end thereof.

9. Quick-change device (1) in accordance with any of the preceding claims, wherein separate hydraulic couplings (12, 13, 14), which are elastically or spring mounted, are provided in the at least one locking component (9, 10, 11).

10. Quick-change device (1) in accordance with any of the preceding claims, wherein the side plates (3, 4), in an area opposite to the position where the at least one locking component (9, 10, 11) exits or extends from the main body (2), respectively have a first recess (15) for engagement with a corresponding bolt or projection on the implement.

11. Quick-change device (1) in accordance with any of the preceding claims, wherein the side plates (3, 4), in an area near to the position where the at least one locking component (9, 10, 11) exits or extends from the main body (2), respectively have a second recess (17) for engagement with a corresponding bolt or projection on the implement.

12. Quick-change device (1) in accordance with claim 11, wherein the side plates (3, 4) have a hook-like projection (16) which defines the second recess (17).

13. Quick-change device (1) in accordance with any of the preceding claims, wherein the quick-change device has a directional control valve.

14. Quick-change device (1) in accordance with claim 12, wherein the directional control valve switches hydraulic conduits for secondary functions of the implement and for the locking and unlocking of the quick-change device.

15. Quick-change device (1) for connecting implements to an excavator while simultaneously connecting hydraulic conduits,
said quick-change device (1) comprising a main body (2) in which at least one locking component (9, 10, 11) is accommodated,
wherein the main body (2) is confined or terminated on its sides by side portions (3, 4),
wherein the at least one locking component (9, 10, 11) extends and moves essentially parallel to the side portions (3, 4),
wherein the side portions (3, 4), in an area near to the position where the at least one locking component (9, 10, 11) exits or extends from the main body (2), respectively have a recess (17) for engagement with a corresponding bolt or projection on the implement.

16. Quick-change device (1) in accordance with claim 15, wherein the side portions (3, 4) have a hook-like projection (16) which defines the recess (17).

17. Implement for cooperation with the quick-change device (1) of claim 15 or 16, wherein the implement comprises a bolt or projection for engagement with the recess (17) of the quick-change device (1).

18. Combination of a quick-change device in accordance with any of claims 1-16 and an implement in accordance with claim 17.

Drawing