CONSTRUCTION MACHINE AND METHOD FOR OPERATING A CONSTRUCTION MACHINE

Abstract

The invention relates to a construction machine, in particular drilling rig, comprising a mast, along which a tool is movably mounted, wherein the tool is suspended on a cable which can be actuated by means of cable winch for raising and lowering the tool, which cable winch is driven by an electric motor, as a winch drive, in a drive mode, wherein the electric motor is designed for operating in a recuperation mode in which the electric motor preferably generates electrical energy when the tool is lowered and outputs said electrical energy to an energy store, and a controller, which is designed to actuate the electric motor, depending on a specifiable target value, in such a way that the cable is tensioned both in the drive mode and in the recuperation mode of the electric motor.

Claims

1. A construction machine, in particular drilling rig, comprising a mast, along which a tool means is movably mounted, wherein the tool means is suspended on a cable which can be actuated by means of cable winch for raising and lowering the tool means, which cable winch is driven by an electric motor, as a winch drive, in a drive mode, wherein the electric motor is designed for operating in a recuperation mode in which the electric motor preferably generates and outputs electrical energy when the tool means is lowered, and a controller, which is designed to actuate the electric motor, depending on a specifiable target value, in such a way that the cable is tensioned both in the drive mode and in the recuperation mode of the electric motor.

2. The construction machine according to claim 1, wherein the target value for the electric motor is a specified cable traction.

3. The construction machine according to claim 2, wherein a force measuring device is provided for measuring the cable traction, and in that the force measuring device is connected to the controller for the purpose of controlling the electric motor depending on the measured cable traction.

4. The construction machine according to claim 3 wherein the force measuring device comprises a force measuring pin on a deflection roller of the cable, or a force measuring lug on a winch block of the cable winch.

5. The construction machine according to claim 2, wherein the specifiable cable tension can be changed by means of the controller.

6. The construction machine according to claim 1, wherein the construction machine is designed as a drilling rig, on the mast of which a rotary drilling drive is adjustably mounted, which drive can be moved along the mast by means of at least one actuating drive.

7. A method for operating a construction machine, in particular according to claim 1, comprising a mast, along which a tool means is movably mounted, wherein the tool means is suspended on a cable which is actuated by means of a cable winch in order to raise and lower the tool means, which cable winch is driven by an electric motor, as a winch drive, in a drive mode, wherein the electric motor is designed for operation in a recuperation mode in which the electric motor preferably generates and outputs electrical energy during lowering of the tool means, wherein the electric motor is actuated by a controller dependent on a specifiable target value, such that the cable is tensioned both in the drive mode and in the recuperation mode of the electric motor.

8. The method according to claim 7, wherein the electric motor is actuated dependent on a specifiable cable traction as the target value.

9. The method according to claim 8, wherein the specifiable cable traction is changed by the controller or an operator.

10. The method according to claim 7, wherein a cable traction is measured by means of a force measuring device, wherein the force measuring device is connected to the controller, wherein the electric motor is controlled or adjusted dependent on the measured cable traction.

Description

[0024] The invention will be described in more detail in the following, with reference to a preferred, exemplary embodiment which is shown schematically in the FIGURE.

[0025] The single the FIGURE is a side view of a construction machine 10 according to the invention, comprising a carrier device 12. The carrier device 12 comprises a tracked chassis as an undercarriage 14, on which an upper structure 16 is rotatably mounted. A controller 60 for the construction machine 10 is located in a control cab of the upper structure 16. A mast 20 is adjustably mounted on the upper structure 16 by means of a link mechanism 18, which mast is in a substantially vertical position during operation.

[0026] According to the exemplary embodiment shown, the mast 20 can be designed as a leader 21 having a linear guide 24 on the front side thereof. A work carriage 38 comprising a rotary drilling drive 36 can be mounted so as to be vertically movable along the linear guide 24. As a result, the construction machine 10 can be designed as a drilling rig. In the FIGURE, an upper position of the rotary drilling drive 36, and a lower position with an interrupted linear guide, are shown.

[0027] A cable 40 can be guided over a mast head 22 at the upper end of the mast 20, at one end of which cable a preferably telescopic Kelly bar 32, comprising a drilling tool 34 as the tool mean 30 is provided. The Kelly rod 32 can be guided on the work carriage 38 by means of a sleeve-like drive wheel of the rotary drilling drive 36, such that a torque can be transmitted from the rotary drilling drive 36 via carrier bars (not shown) to the Kelly bar 32. A drilling tool 34 for making a drilled hole in the ground is arranged at the lower end of the Kelly bar 32. The drilling tool 34 can in principle be designed as desired, and can in particular comprise an auger or a drilling bucket.

[0028] Proceeding from the Kelly bar 32, the cable 40 is guided along the mast 20, via deflection rollers 26 on the mast head 22, as far as a cable winch 46 in the upper structure 16. According to the invention, the cable winch 46 is driven by an electric motor 50, which can also be operated in a recuperation mode. The Kelly bar 32, together with the drilling tool 34, can be raised and lowered via the cable winch 46, by means of the cable 40. During lowering, potential energy can be converted, by the electric motor 50, into electrical energy and output to a storage device or an electrical consumer.

[0029] The work carriage 38, together with the rotary drilling drive 36, can be drawn upwards via a further adjusting cable 29, by means of an adjusting drive 28 comprising a winch, on the mast 20. Corresponding driving of the adjusting drive 28 in the opposite direction makes it possible for the work carriage 38, together with the rotary drilling drive 36 to also be lowered downwards. The adjusting drive 28 can also be equipped with an electric motor (not shown) which can likewise be operated in recuperation mode The work carriage 38 comprising the rotary drilling drive 36 can also be considered as part of the tool means 30.

[0030] In the embodiment shown, a force measuring device 62 is preferably arranged on a deflection roller 26, on the mast head 22. The force measuring device 62 can for example be designed as a force measuring pin, by means of which a cable traction at the cable 40 can be detected. The force measuring device 62 is connected to the controller 60 on the upper structure 16.

[0031] The controller 60 actuates the at least one electric motor 50 for operating the cable winch 46, and preferably also the further electric motor for operating the adjusting drive 28 designed as a winch. In this case, the actuation of the electric motor 50 by the controller 60 is carried out in such a way that the at least one electric motor 50 is actuated, depending on a specified target value for the cable traction, in such a way that the cable 40 has a provided minimum tension not only in the drive mode but also in the recuperation mode of the electric motor 50. In particular, the controller 60 can control and change an electromotive resistance of the at least one electric motor 50., wherein the recuperation capacity of the electric motor 50 also changes accordingly. The controller 60 is designed, overall, such that a minimum tension of the cable 40 is ensured, even if the recuperation capacity of the electric motor 50 is reduced as a result, compared with a maximum possible value, at least for a certain period of time. A sufficient cable tension ensures that no slack line forms, for example in the case if braking of the drilling tool 34 is taken place during lowering into a borehole filled with liquid. As a result, the formation of slack line, with the risk of the cable 40 springing out of the deflection roller 26 or a disordered winding on the cable winch 46 is prevented.

[0032] The construction machine 10 according to the invention, and the associated method according to the invention, make it possible for a more energy-saving, and thus more environmentally friendly and more economical, operation to be achieved, with still reliable operating procedure.