EP0065118A2 - Excavator - Google Patents

Abstract

In the case of an excavator with a support frame (1) and support arms (2, 3), on which wheels (4) and / or footrests (5) are arranged, there is always the problem of a simple changeover from walking operation to driving operation. In the excavator described, a height-adjustable wheel (9) is arranged on the superstructure (6), which can be rotated with respect to the supporting frame (1) about an approximately vertical axis (7), which in the lowered position together with at least one pair of supporting arms (3 ) arranged wheels (4) forms a chassis. At least one of the wheels (4 or 9) is driven.

Description

The invention relates to an excavator, consisting of a support frame, each with a pair of support arms on opposite sides thereof, on which wheel and / or footrests are arranged, and a superstructure which can be rotated about an approximately vertical axis relative to the support frame and on which a digging, Cutting or machining tools carrying boom attacks.

Excavators of this type (AT-A-305.910) are very mobile and can therefore be used in the most difficult terrain, because to move the excavator, the front end of the support frame is raised during operation by supporting the digging tool against the ground, the excavator by moving the tool supporting boom moved back and forth or steered by turning the superstructure and then lowered back onto the footrests, so that the excavator moves gradually by repeating these operations. To adapt the excavator to uneven terrain, it is known to pivot each support arm independently and independently of the others in a vertical plane. However, only a so-called walking movement is possible here.

In order to bring such excavators to a construction site or from one job to another, there is practically only the possibility to transport the excavator as a trailer vehicle. If the locomotion takes place in the field or on a street due to the walking movement, on the one hand damage to the ground results from the intervention of the digging tools and on the other hand the locomotion speed to be achieved is nevertheless very low.

An embodiment has already become known (DE-B- - 2807 517), in which a combination of a walking movement and a pure driving movement is sought. It For this purpose, both wheels and footrests are arranged on the free ends of the support arms, which are lowered as required. When digging, the footrests are in use and the wheels are raised accordingly, whereas when the excavator moves to another construction site, the wheels are lowered and the footrests are raised. On the one hand, with such a configuration, it is necessary to provide additional possibilities for steering these wheels provided at the free ends of the support arms, and on the other hand, these wheels and footrests always arranged on the free ends of the support arms represent a space problem.

The present invention has for its object to provide an excavator that can perform both a pure walking movement and a pure driving movement without the need for the arrangement of edges on all four support arms, the steering should be made possible in a simple manner .

According to the invention it is proposed that at least one height-adjustable wheel is arranged on the superstructure, and at least one of the wheels arranged on the superstructure and on the support arms is designed to be driven.

By means of these measures according to the invention, a quick changeover is created in a structurally simple manner in order to be able to convert the excavator from a pure walking movement into a pure driving movement. The height of such a wheel can be adjusted using structurally simple means, no additional measures being required for the steering during the travel movement, since this steering can be carried out in a simple manner by rotating the superstructure about an approximately vertical axis.

The measure according to the invention also brings a significant advantage in terms of space, since wheels do not have to be additionally attached to the free ends of at least one pair of support arms. It is therefore possible to design the footrests arranged at the free ends of these support arms in a necessary manner, since the space conditions are not influenced by additional wheels to be attached. In addition, the usability of the excavator is much greater, since relatively narrow support arms are required, especially in difficult and steep terrain, on which then no additional ballasts projecting laterally should be at the front. Without difficult measures, the excavator operator can quickly switch from a walking operation to a driving operation, it being very important that the wheel additionally arranged on the superstructure of the excavator does not impede the excavator operator in terms of either the least or the unobstructed view.

Further features according to the invention and special advantages are explained in more detail in the following description with reference to the drawings.

• Fig. 1 eine Seitenansicht eines Baggers in Arbeitsstellung;
• Fig. 2 eine Draufsicht gemäß Fig. 1;
• Fig. 3 einen Bagger in Fahrstellung und
• Fig. 4 eine Draufsicht auf diese Stellung gemäß Fig. 3;
• Fig. 5 eine Draufsicht auf einen Bagger in Fahrstellung, wobei ein Lenkvorgang angedeutet ist;
• Fig. 6 eine Seitenansicht eines zweiten Ausführungsbeispieles, wobei die Fahrstellung dargestellt ist;
• Fig. 7 eine Draufsicht gemäß Fig. 6;
• Fig. 8 eine Draufsicht auf einen am Oberbau höhenverstellbaren Tragteil, wobei eine Lenkeinstellung des Rades dargestellt ist.

Show it:

• Figure 1 is a side view of an excavator in the working position.
• FIG. 2 shows a top view according to FIG. 1;
• Fig. 3 shows an excavator in the driving position
• FIG. 4 shows a top view of this position according to FIG. 3;
• 5 shows a plan view of an excavator in the driving position, with a steering process being indicated;
• Fig. 6 is a side view of a second embodiment, the driving position is shown;
• FIG. 7 is a top view according to FIG. 6;
• Fig. 8 is a plan view of a height-adjustable support part on the superstructure, wherein a steering setting of the wheel is shown.

The excavator consists of a support frame 1, a pair of support arms 2 and 3 being arranged on opposite sides of the support arm frame 1. Wheels 4 and footrests 5 are arranged on these support arms. The superstructure 6 of the excavator can be rotated relative to the support frame 1 about an approximately vertical axis 7. A boom 8 acts on this superstructure 6, only a part of this boom 8 being shown in FIGS. 1 and 3. G _rab , cutting or machining tools are then arranged at the free end of this boom 8, the movement of the boom and these tools being effected by hydraulic cylinders.

A height-adjustable wheel 9 is arranged on the superstructure 6. This ^d ad 9 is expediently arranged on the side of the superstructure 6 opposite the boom 8 and held at the free end of an arm 11 which can be pivoted about a horizontal axis 10 on the superstructure. This arm 11 is pivotally held by a hydraulic cylinder 12. One or both wheels 4 can be equipped with a hydraulic drive in order to achieve a driving movement.

When working, the excavator is in the position shown in Figs. 1 and 2, i.e. digging or other work is carried out with the boom between the two support arms 2. The support arms 3 with the wheels 4 are arranged opposite the boom 8. When the excavator strides forward, the tool arranged at the free end of the boom 8 is supported on the ground, and by lifting and bending the boom 8 the support arms 2 are raised on the one hand and on the other hand the excavator itself is pulled further in the direction of the arrow 13. After lifting the boom, the support arms 2 are lowered again so that the footrests 5 are used. Work can now continue at the new location. The wheel 9 arranged on the superstructure 6 is located on the rear of the driver's cab 14 and is therefore in no way a hindrance during the excavation work.

If now a greater distance to be covered Agger with the ^B, it is possible in a simple manner to a driving operation - to be changed by the moment of the upper structure is rotated through approximately 1800 about the vertical axis 7 6 namely, so that with constant position of the support frame 1 and thus the support arms 2 and 3 of the boom 8 now point in the other direction, as shown in FIGS. 3 to 5. Now the wheel 9 can be pivoted downwards by the hydraulic cylinder 12, so that this wheel 9 is supported on the drivable floor. The support arms 2 and thus the footrests 5 are raised solely by correspondingly depressing the wheel 9. Of course, it is also possible to additionally raise the footrests 5 by actuating the hydraulic cylinders 15.

In this position, a three-wheel chassis is created, so to speak, which has a relatively good stability due to the large wheelbase. Since the track width of the wheels 4 is also large, a tilting movement cannot occur despite the arrangement of only one wheel 9 on one side. By inserting a corresponding drive on the wheels 4, the excavator can now be moved in any manner, steering being possible in a very simple manner by rotating the superstructure 6 about a vertical axis 7. Such a rotary setting can be found in particular in FIG. 5 from which it can be seen that a steering operation can be carried out very easily.

After the receipt of the new job, only the wheel 9 must be increased accordingly by means of the arm 11, whereupon the arm 8 is again ready for use after turning the superstructure by 180 6 ^0th So there is very little work to be done, and all of this work can be carried out in a simple manner from the cab by inserting hydraulic cylinders.

In the embodiment according to FIGS. 6 to 8, the wheel 9 is also provided on the side of the superstructure 6 opposite the arm 8. A supporting part 20 is connected to the superstructure 6 so as to be pivotable about a horizontal axis 21, wherein this supporting part 20 can be pivoted downwards into a driving position or upwards into a rest position by hydraulic cylinders 12. The wheel 9 is held in an approximately U-shaped support arm 23, the support arm 23 being pivotable about the axis 22 relative to the support part 20. This axis 22 lies in an approximately vertical plane and is oriented approximately vertically in the driving position (FIG. 6), the angle of the axis 22 to the vertical depending on the adjustment angle of the support part 20 deviating accordingly from the vertical. It only has to be achieved that the wheel 9 receives a steering lock by rotating the support arm 23 about the axis 22. The wheels 4 and 9 can be dimensioned differently or can also have the same size (diameter, width).

In this embodiment, the pivot axis 22 between the support arm 23 and the support member 20 is seen in the operating position of the wheel 9 at a horizontal distance from the axis of rotation 24 of the wheel 9. Of course, it is also possible within the scope of the invention to arrange the wheel 9 directly below the support part 20, so that the support arm 23 is aligned in an approximately vertical position, in which case the axes 22 and 24 intersect. A corresponding steering deflection can also be achieved in a simple manner in such an embodiment.

To carry out the steering movement, a hydraulic cylinder 25 is provided which engages both on the support arm 23 and on the support part 20. This hydraulic cylinder 25 engages one leg of the U-shaped support arm 23, so that when the piston of the hydraulic cylinder is pushed or retracted, the support arm 23 is entangled about the axis 22 becomes. The greater the distance between the fastening points of the hydraulic cylinder 25 and the axis 22, the smaller the force required for the steering movement. If the hydraulic cylinder only acts on the support arm 23 via a short lever arm in relation to the axis 22, then the adjustment movement of the support arm 23 is greater with respect to the movement of the hydraulic cylinder 25, but correspondingly greater forces are then required.

The support part 20 is shown in the drawing as a closed plate, it being possible, of course, to choose from different design variants. Of course, a pure frame construction is also possible. If appropriate, it would also be possible with a corresponding structural design to provide only one hydraulic cylinder 12 instead of the two hydraulic cylinders 12 for pivoting the supporting part 20. The structural design of the support arm can also be carried out in various ways. It would also be conceivable to provide only a type of L-shaped design for the support arm 23, so that the wheel 9 can then be attached to one leg of this support arm 23 on the fly.

For digging or other work, the excavator is in a position in which the boom lies between the two support arms 2, that is to say in a position pivoted by 180 ° with respect to the illustration in FIGS. 1 and 2. If a longer distance is now to be covered with the excavator, it is easy to switch to driving mode, namely by initially rotating the superstructure 6 about the vertical axis 7 by approximately 180 °, so that the supporting frame 1 remains in the same position and thus the support arms 2 and 3 of the boom 8 now point in the other direction, as shown in FIGS. 1 and 2. Now the wheel 9 with the supporting part 20 can be pivoted downwards by the hydraulic cylinders 12, so that the wheel 9 is supported on the drivable floor. The support arms 2 and thus the footrests 5 are raised solely by correspondingly depressing the wheel 9. Of course, it is possible to additionally raise the footrests 5 by actuating the hydraulic cylinders 15.

If curves with a relatively narrow radius are now to be negotiated, a greater steering setting can be achieved by the pivotability of the wheel 9 relative to the support part 20. The steering process can therefore be achieved solely by pivoting the support arm 23 on the support part 20 or by rotating the superstructure 6 or by mutual support of both measures.

By the embodiment according to FIGS. 6 to 8, regardless of the distance between the support arms which carry the footrests or wheels, steering can also be carried out additionally or separately from the steering movement by rotating the superstructure, so that even curves with a relatively small radius can be carried out in a simple manner can be driven on. This construction represents an additional improvement of the embodiment according to FIGS. 1 to 5, without requiring a great deal of design effort.

It is also of particular advantage that the superstructure can remain aligned in the longitudinal direction of the excavator, particularly in narrow passages, so that in such cases the wheel alone can be pivoted relative to the height-adjustable support part.

Instead of your pivotable arm 11 or a support member 20, there are of course also other possibilities for arranging the wheel 9 in an adjustable manner. For example, it would also be conceivable to provide vertical guide rails along which a corresponding wheel carrier (arm 11 or support part 20) can be moved. It would also be think bar, such a wheel 9 to be provided laterally next to the driver's cab 14 on the side areas of the superstructure 6, in which case these wheels can also be lowered accordingly.

Within the scope of the invention, it would also be conceivable to design the wheel 9 to be driven or possibly only to drive this wheel 9 and to design the wheels 4 without a drive. An embodiment according to the invention can of course also be used in excavators in which, for example, footrests and wheels are provided, which can be used alternately on the support arms 3. These wheels are then lowered according to a driving movement and the footrests are raised. Of course, at least three wheels are required for a real movement.

The configuration according to the invention is thus designed in a structurally simple manner so that an excavator which essentially functions as a walking excavator when used in work is so that it can be continuously converted into a mobile excavator if required.

Claims (9)

1. Excavator, consisting of a support frame (1), each with a pair of support arms (2, 3) on opposite sides thereof, on which wheels (4) and / or footrests (5) are arranged, and an approximately vertical axis ( 7) the superstructure (6), which can be rotated relative to the supporting frame (1) and on which a boom (8) carrying a digging, cutting or processing tool acts, characterized in that at least one height-adjustable wheel (9) is arranged on the superstructure (6), and at least one of the wheels (4, 9) arranged on the superstructure (6) and on the support arms (2, 3) is designed to be driven. 2. Excavator according to claim 1, characterized in that the wheel (9) on the boom (8) opposite side of the superstructure (6) is arranged. 3. Excavator according to claims 1 and 2, characterized in that the wheel (9) is held at the free end of an arm (11) pivotable about a horizontal axis (10) on the superstructure (6). 4. Excavator according to claim 3, characterized in that the arm (11) carrying the wheel (9) is hydraulically height-adjustable. 5. Excavator according to claim 1, characterized in that the wheel (9) on a rotatable superstructure (6) height-adjustable support member (20) about a lying in a vertical plane and approximately vertically aligned axis (22) is held pivotably. 6. Excavator according to claim 5, characterized in that the wheel (9) is mounted in an approximately U-shaped support arm (23) and this support arm (23) is pivotally connected to the support member (20). 7. Excavator according to claims 5 and 6, characterized in that the pivot axis (22) between the support arm (23) and support member (20) in the operating position of the wheel (9) and the axis of rotation (24) of the wheel (9) in the horizontal direction seen at a distance from each other. 8. Excavator according to claims 5 and 6, characterized in that the pivot axis (22) for the wheel. (9) or its support arm (23) and the axis of rotation (24) of the wheel (9) are arranged in a common plane . 9. Excavator according to claims 5 to 8, characterized in that a hydraulic cylinder (25) or piston engages on the supporting part (20) and on the supporting arm (23) at a distance from the axis (22).

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