EP0569026B1 - Quick coupling device - Google Patents

Abstract

Quick-coupling device for earthmoving vehicles for exchanging implements which are detachably connected to an adaptor pivotable on the boom of the earthmoving machine about a horizontal axis, the adaptor having fixed and displaceably mounted coupling members (36) to which fixed coupling members (16) on the implement are allocated, and the displaceably mounted coupling members (36) of the adaptor being locking bolts having coupling surfaces with tapered circumferences, to which coupling members having tapered circumferences on the implement are allocated, which are designed so as to be load-bearing merely over an area of 180 DEG with the corresponding tapered circumferences of the allocated fixed coupling members (16) of the implement. <IMAGE>

Description

The invention relates to a quick-change device for earthmoving vehicles for replacing work tools, which are releasably connected to the boom by means of an adapter which can be pivoted about a horizontal axis on the boom of the earthmoving machine and which has coupling elements designed as fixed claws and mounted as displaceable locking bolts, to which corresponding coupling elements are attached Appliances are assigned, of which the one coupling member has an opening for the entry of the sliding coupling members locking plate and the other coupling member forms a coupling axis at least partially encompassed by the claws, the bracing between the adapter and the implement taking place via the abutment surfaces of the coupling members.

EP-A 0 273 828 shows such a fixed and displaceable coupling member quick change device. Since space is required for pivoting and pivoting the adapter into the implement relative to the locking plate, this is correspondingly far away from the coupling axis to be gripped by the claws, so that only the claws with the coupling axis and the bolts with the openings in the locking plate are clamped when coupling. As a result of this design of the coupling members, only a uniaxial bracing between the implement and the adapter on the boom takes place via the abutment surfaces of the coupling members. However, such a connection is not sufficiently rigid for heavy earthmoving operations. In addition, due to the essentially linear contact between the coupling surfaces during use of the earth moving vehicle, high relative surface loads occur on the coupling members.

However, both lead to undesirable rapid wear of the coupling members. Finally, instructing help for the driver of the earthmoving vehicle is necessary for changing tools.

Furthermore, quick-change devices are known in which the coupling members fixed to the housing have a coupling axis on the implement and these partially encompassing receiving claws on the extension arm, the displaceably mounted coupling element being a spring-loaded wedge which interacts with the fixed coupling element arranged on the implement in the form of a hook, the wedge can be locked outside the active position by a locking device which is triggered during the coupling process between the boom and the implement, so that for the purpose of locking the wedge is pushed under the hook under the action of the spring; see AT-B 389 906.

It is also known to design the displaceable coupling members as locking bolts which can be inserted into associated bores in a support plate of the implement via a lever mechanism; see DE-B 1 784 323.

There are also known quick-change devices in which spring-loaded pawls are provided as movable coupling members, which overlap a counter-locking part in the coupling state and can be unlocked against the spring force by external force application; compare DE-A 3 312 442.

Finally, from EP-A 0 143 074 a device for fastening a spoon to the boom of an excavator is known, which consists of a gripping device on the boom and a catching device on the bucket. Via a hydraulically driven wedge arranged on the gripping device, which, in the locked state, grips between the surfaces of two lugs on the catching device and the bottom surface of the gripping device, which enclose an acute angle with one another clamps the gripping device, which rests against a bolt of the safety device, via a wall formed as a ring segment.

Apart from the danger that the safety gear, which is open to the outside, is quickly clogged with dredged material in rough excavator operation, the forces acting on the bucket act in the opening direction on the wedge, which is only held hydraulically, ie resiliently. Furthermore, since the distance between the opposing abutment surfaces of the catching device and the gripping device must be strictly observed for securely bracing the catching device and the gripping device, there is an exchangeable wear plate between the abutting surfaces of the catching device and the gripping device adjacent to the wedge. The wear of such a wear plate can only be monitored very imprecisely, so that the operational safety of the known device leaves many wishes unfulfilled.

In addition to the properties of the quick-change device explained at the outset, these quick-change devices also have in common the complex training and the susceptibility to malfunction, taking into account the rough use in earthmoving work. Also, with these quick-change devices, the goal of carrying out a change of the work equipment by the driver of the earth-moving machine alone without additional auxiliary personnel cannot be achieved.

On the other hand, however, there is a great need for quick-change devices that work reliably over long operating times and are easy to operate.

Starting from the quick-change device according to EP-A 0 273 828, the object of the invention is to further develop it in such a way that reliable use of less and also taking into account the unavoidable wear over long operating times of components reliably locking the implement and boom of an earth moving machine alone from the driver.

This object is achieved in that the one abutment surface of the coupling members of the adapter is designed as a cylindrical jacket-shaped abutment surface delimited on both sides by the claws for the purpose of support on the outer surface of the coupling axis of the implement, while the other abutment surface is flat and forms an imaginary plane connecting both abutment surfaces is arranged inclined that the locking plate has an abutment surface of the adapter facing and corresponding with this and in the locked state fully lying abutment surface, and that the abutment surfaces with the surfaces of the sliding coupling members and the openings corresponding to them in the locking plate a sliding and tensioning mutually facing abutment surfaces of the adapter and the implement form a wedge gear.

According to a further feature of the invention, the coupling surfaces of the displaceably mounted coupling members of the adapter and the coupling members of the implement are designed and assigned to one another in such a way that they form a wedge gear that clamps the adapter housing and the adapter plate together.

According to a further feature of the invention, the coupling surfaces of the displaceable coupling members and the coupling surfaces of the associated coupling members of the locking plate are designed as conical outer surfaces which correspond to one another over a circumferential angle of approximately 180 °, the circumferential partial surfaces of the coupling members assigned to the locking plate being complementary to the circumferential angle being 360 ° Include a predetermined bearing clearance circumferential surface areas of the sliding coupling members.

Further advantageous embodiments of the invention result from the subclaims.

The inventive design of the components of the quick-change device used for locking has the advantage that during the locking process the locking bolts essentially have a supporting function in the upper lateral surface half of the frustoconical area and the oblique clamping surface of the adapter housing slides over the entire surface onto the oblique clamping surface of the locking plate, so that with a multiaxial bracing of adapter and implement takes place simultaneously with the initiation of the locking process.

During the coupling process, the adapter housing is pressed forward against the coupling axis, and the preferably elliptical space between the locking bolts and openings in the locking plate ensures that the locking bolts continuously adjust, that is to say can move into the locking position. The locking bolts, which are under spring tension, thus assume a low-tension function, whereby the contact claws on the coupling axis create a surface pressure between the above-mentioned inclined surfaces.

If tolerances caused by wear should occur, these are compensated for by the fact that the spring-loaded locking bolts can be pushed further into the free space of the openings in the locking plate.

By means of the centering elements, a pre-centering is achieved when lowering the adapter housing onto the adapter plate assigned to the implement, which not only facilitates the locking process and significantly reduces wear due to canting between the adapter housing and implement, but also enables instruction-free changing of implement.

The switching shaft of the locking device can be driven both mechanically and hydraulically, in the mechanical embodiment, an articulated lever mechanism with locking via the dead center, and in the hydraulic embodiment, the locking bolts are articulated via an oscillating pressure compensation bridge and a hydraulic cylinder.

Figur 1

einen Querschnitt der teilweise dem Ausleger einer Erdbewegungsmaschine und teilweise dem Arbeitsgerät zugeordneten Schnellwechselvorrichtung vor dem gegenseitigen Eingriff,

Figur 2

die Schnellwechselvorrichtung nach Figur 1 in Eingriff und

Figur 3

eine Ansicht auf eine Einzelheit der Schnellwechselvorrichtung in Richtung des Pfeiles 3 in Figur 1.

The invention is described below with reference to an embodiment shown in the drawing. Show in it:

Figure 1

1 shows a cross section of the quick-change device, which is partly assigned to the boom of an earthmoving machine and partly to the implement, before mutual engagement,

Figure 2

the quick-change device according to Figure 1 in engagement and

Figure 3

a view of a detail of the quick-change device in the direction of arrow 3 in Figure 1.

A quick change device, designated overall by the reference number 10 in FIG. 1, comprises an adapter consisting of adapter housing 30 and adapter plate 12, of which the housing 30 is associated with an extension arm (not shown here) of an earthmoving machine (also not shown) and the adapter plate 12 is associated with the implement (also not shown) so they are firmly connected.

The adapter plate 12 comprises a base plate 14, on which a locking plate 16 is welded at one end and a coupling axis 19 is welded at the opposite end by means of fastening tabs 17. The locking plate 16 has on the side facing the coupling axis a clamping surface 20 which is inclined to the vertical surface 20 'by 3 ° to 35 °, preferably by 5 ° to 15 °. The locking plate 16 is furthermore, as can be seen in particular from FIG. 3, provided with two openings 21 and 22 which are arranged at a distance a from one another and have a conical cross section. The cone angle of the openings delimited by conical surface areas is dimensioned accordingly and is 5 ° to 15 ° in the exemplary embodiment shown.

These 360 ° conical surface areas of the openings 21 and 22 are each assigned two centers Z1 and Z2 at the same distance, so that there are two conical surface areas, of which the lower conical surface area in relation to FIG. 1 compared to the imaginary, the upper conical surface area to a complete one Truncated cone complementary conical surface has a bearing play S to be described.

The approximately cuboidal adapter housing 30 has a receiving claw 31 on its side faces, which in the retracted state - compare FIG. 2 - encompass the coupling axis 19. The end face of the housing 30 located between the receiving claws 31 merges into an abutment surface 32 in the form of a cylinder jacket, which — as also shown in FIG. 2 — is supported on the cylinder jacket surface of the coupling axis 19 in the retracted state.

The facing end face 34 is inclined by 3 ° to 35 °, preferably by 5 ° to 15 °, with respect to the vertical - corresponding to the clamping surface 20 of the locking plate 16 - and also has two openings 35 through which one each is mounted in the housing 30 so as to be longitudinally displaceable Latch bolt 36 can pass through.

Each locking bolt 36 has a spring 38 arranged in a blind bore 37, the free end of which is supported on a spring plate 39, to which the end face of an angle lever 41 is assigned. The angle lever 41 is articulated by means of a connecting bolt 42 on a switching cam 43 which is fixedly connected to a switching shaft 44. The facing arm of the angle lever 41 is connected in an articulated manner to the locking bolt 36 via a connecting bolt 45, which extends through an elongated hole 46 at the facing end of the locking bolt 36.

The parts described above form a known toggle lever mechanism, which is driven via the selector shaft 44 and moves beyond the dead center position - imaginary connecting line of the center points of the selector shaft 44 and connecting bolt 45 - when moving from the rest position shown in FIG. 1 into the working position shown in FIG and locked with it. In this way, automatic release of the extended locking bolts 36 from the locking position shown in Figure 2 is prevented.

The opposite ends 50 of the locking bolts 36 are frustoconical in shape with a cone angle of 5 ° to 15 ° and correspond to the openings 21, 22 in the locking plate 16, as can also be clearly seen from FIG. 2.

For the purpose of pre-centering when lowering the adapter housing 30 onto the adapter plate 12 of the implement, centering members are provided, of which the centering members assigned to the adapter housing 30 are designed as cylindrical pins 52 (FIG. 1) which lie in the flat end face 34 on both sides of the displaceable locking bolts 36. The centering members assigned to the locking plate 16 are inclined surfaces 51 (FIG. 3) lying in the lowering path of the adapter housing 30. When the adapter housing 30 is lowered onto the adapter plate 12 - see FIG. 1 - as a result of the inclined surfaces 51, the adapter housing and thus the displaceable locking bolts 36 are aligned and thus centered with respect to the openings 21, 22, so that the coupling process between locking bolts 36 and openings 21 , 22 is carried out without interference.

As a result of the eccentricity - bearing play S - of the lower conical surface portions of the openings 21, 22 of the locking plate 16 in relation to FIGS. 1 to 3, in the engagement position according to FIG. 2, the frustoconical end regions 50 of the locking bolts 36 lie only on the upper partial conical surface surfaces of the openings 21, 22 , ie over about 180 ° of the circumferential surface, while the conical surface areas of the lower regions do not lie but are exposed, as is indicated by the gap S in FIG. For this purpose, the planes assigned to the centers Z1 - compare FIG. 3 - are aligned so that they cut the connecting bolts 45 of the locking bolts 36 in the center and the locking bolts 36 are guided in parallel in the adapter housing 30 by means of correspondingly dimensioned slide bearings 49.

In this engagement position, in which the adapter housing 30 between the abutment surface resting on the coupling axis 19 32 and the clamping surface 20 of the locking plate 16, which lies against the end face 34 of the adapter housing, the locking bolts 36 clamp the adapter housing 30 on the adapter plate 12 as a result of the locking bolts 36 being moved from the rest position shown in FIG. 1 to the position shown in FIG. 2 Actual position shown as a wedge gear acting conical surface areas and form the second load-transmitting bearing point of the quick-change device, which is opposite the coupling axis 16 forming the first bearing point, which is encompassed by the receiving claws 31.

Of course, other geometrical shapes of the clamping surfaces and locking surfaces are also possible without leaving the inventive concept; For example, instead of conical surface areas, flat inclined surfaces for the movable locking members and their associated housing-fixed coupling members are also possible. The only decisive factor is that there is sufficient bearing play S between the coupling members concerned and forming a wedge gear.

Claims (3)

1. Quick change device (10) for earth moving vehicles for changing implements, having an adaptor (30), which is pivotable about a horizontal axis on a bracket of the earth moving machine and has coupling members which are constructed as fixed claws (31) and coupling members which are constructed as shiftable locking pins (36) which are routed in parallel, for detachably connecting coupling members (16, 19) on the implement that correspond thereto, of which the one coupling member is a locking plate (16) having openings (21, 22) for insertion of the shiftable coupling members (36), and the other coupling member forms a coupling axle (19) which is surrounded at least partially by the claws (31), with the abutment surface (32) of the coupling members of the adaptor (30), which abutment surface is associated with the claws (31), being constructed as a cylinder-jacket-like abutment surface which is delimited on both sides by the claws (31), for the purpose of support on the lateral surface of the coupling axle (19) of the implement, while the abutment surface (34) which is associated with the locking plate (16) is constructed in a manner such that it is planar and is arranged in a manner such that it is inclined with respect to a perpendicular surface (20') of the locking plate (16) and has an abutment surface (20) which faces the abutment surface (34) of the adapter (30) and corresponds thereto and in the locked state rests with its full surface thereon, and the coupling surfaces (50) of the shiftable coupling members (36) and the coupling surfaces of the associated coupling members (21, 22) of the locking plate (16) are constructed as conical lateral surfaces which correspond to each other over an angle at circumference of approximately 180°, with the partial circumferential surfaces of the coupling members (21, 22) associated with the locking plate (16), which partial circumferential surfaces make up the angle at circumference to 360°, together with the associated circumferential surface regions of the shiftable coupling members enclosing a predetermined bearing clearance (S), the abutment surfaces (34, 20) together with the surfaces of the shiftable coupling members and the openings in the locking plate (16) that correspond thereto forming a wedge mechanism which forces sliding on and bracing of the abutment surfaces (34, 20, 32, 19) of adapter and implement that face each other, and the locking pins (36) which are routed in parallel by means of bearing sleeves (49) in the adaptor housing (30) being constructed in a manner such that, by way of a common selector shaft (44), by means of a respective knee lever mechanism (41, 42, 43, 45) with the insertion of a respective compression spring (38), they can be moved out of the position of rest into the active position which is below the dead centre position.
2. Quick change device according to claim 1, characterised in that the coupling members constructed as locking pins (36) and the coupling members (21, 22) associated with the locking plate (16) and corresponding to the circumferential surfaces (50) of the shiftable coupling members have two centres (Z1, Z2) arranged at a distance (S), of which the one centre (Z1) lies centrally with respect to the associated locking pin (36).
3. Quick change device according to claim 1, characterised in that the planar abutment surfaces (20, 34) have an inclination of 3° to 35°, preferably 5° to 15°, with respect to the vertical surface (20'), and in that the coupling surfaces (50, 21, 22) have an angle of inclination which corresponds to the inclination of the abutment surfaces.

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