DRILLING DRIVE ARRANGEMENT FOR UNDERGROUND CONSTRUCTION AND METHOD FOR OPERATING A DRILLING DRIVE ARRANGEMENT FOR UNDERGROUND CONSTRUCTION

Description

The invention relates to a drilling drive arrangement for underground construction, with a drilling drive carriage which is mounted so as to can be displaced along a mast of a drilling rig for underground construction, wherein at least one rotary drive is arranged on the drilling drive carriage for rotatably driving a drilling tool for drilling into a ground, which rotary drive is configured as an electric motor in accordance with the preamble of claim 1.

The invention further relates to a method for operating a drilling drive arrangement for underground construction with a drilling drive carriage which is mounted so as to can be displaced along a mast of a drilling rig for underground construction, wherein at least one rotary drive is arranged on the drilling drive carriage for rotatably driving a drilling tool for drilling of the ground, which rotary drive is configured as an electric motor, in accordance with the preamble of claim 12.

Purely electrically driven underground construction machines have been known for some time now and are used in particular at work sites where noise, vibrations and exhaust gases are undesirable. These burdensome factors can occur, for example, in underground construction machines powered by combustion engines. Due to the high energy requirements of such electrically powered underground construction machines, they often have a supply device for supplying electrical energy from an external power source, in particular from an electrical power grid. This requires the provision of an appropriate electrical cable.

Furthermore, electrically powered underground construction machines are regularly equipped with a rechargeable battery unit, which serves in particular to supply the mobile underground construction machine with sufficient electrical energy during movement or travel, when the electrical cable connection is frequently disconnected. po For efficient operation of the underground construction machine, it is crucial that the energy is distributed at the underground construction machine in a demand-oriented manner. EP 4 245 923 B1 discloses an electrically powered underground construction machine with a drilling drive arrangement and an intermediate circuit for demand-oriented distribution of electrical energy. The intermediate circuit is configured as an electrical conductor to which consumer units, in particular a battery unit and an electric motor, are connected. This ensures that electrical energy is efficiently transmitted to the drilling drive arrangement, in particular to an electric motor, during operation of the underground construction machine. Electrical energy can be supplied from the intermediate circuit to an electric motor via an inverter unit, wherein the inverter unit is configured to return energy to the intermediate circuit in a recuperation mode of the electric motor.

The invention addresses the problem of specifying a drilling drive arrangement for underground construction and a method for operating it, which enable particularly economical and efficient operation of the drilling drive arrangement.

The problem is solved on the one hand by a drilling drive arrangement for underground construction with the features of claim 1 and on the other hand by a method for operating a drilling drive arrangement for underground construction with the features of claim 12. Preferred embodiments are specified in the respective dependent claims.

The drilling drive arrangement according to the invention is characterised in that a control unit for controlling the at least one electric motor is configured with a drillingmode for drilling the drill tool into the ground while removing soil material and a release mode for releasing soil material from the drill tool, wherein, in the release mode, current and/or voltage for supplying electrical energy to the at least one electric motor is automatically controlled such that the drilling tool repeatedly performs a rotation-stop movement with or without a reversal of the direction of rotation.

A basic idea of the invention is to operate a drilling drive arrangement in different operating modes with an electric motor. This is achieved by providing a control unit for the targeted control of the electric motor, wherein different operating states of the drilling drive arrangement can be initiated with the electric motor. Depending on the type of application of the drilling drive assembly, the electric motor can be operated optionally by the control unit in a drilling mode or in a release mode, wherein the drilling mode and the release mode differ in particular in terms of rotational speed and torsional force. This enables particularly flexible and economical use of the drilling drive assembly. A machine operator can operate the drilling drive arrangement safely and efficiently by simply selecting the desired mode.

Another aspect of the invention is to enable the releasing of soil material adhering to the drilling drive arrangement by means of a special control of the electric motor. For this purpose, the current and/or voltage of the electric motor are varied in such a way that the direction of rotation or the rotational speed changes within a short time interval. This means that the current and/or voltage are automatically controlled so that the electric motor performs a rotation-stop movement in order to shake off soil material by briefly changing the rotational speed and torque. This allows soil material adhering to the drilling drive assembly after a drilling operation to be quickly and easily released, resulting in more economical drilling operation overall. The automated control can be effected in particular so that high release forces are exerted, which are hardly possible with manual control of the electric motor.

A preferred embodiment of the invention is that more than two electric motors are provided. It is particularly preferred that at least two electric motors are arranged on the drilling drive carriage, with which a drive shaft, in particular a hollow drive shaft, can be driven in a rotated manner for driving the drilling tool via a summation gear. This allows the drive force to be transmitted particularly efficiently from the drilling drive arrangement according to the invention to the drilling tool. It is advantageous if the at least two electric motors transmit the drive force to a hollow shaft via a summation gear with a planetary gear and, if necessary, further gear stages. This enables a particularly compact construction of the drilling drive arrangement.

The at least two electric motors can in principle be operated synchronously or asynchronously. However, it is particularly advantageous if both electric motors are operated synchronously.

An inverter unit for converting current and/or voltage can be provided in particular for bidirectional power supply of the electric motor. It is advantageous if the at least two electric motors are connected to each other in a rotationally fixed manner via at least one gearing.

A further advantageous configuration of the invention is that the at least two electric motors are torque-controlled by the control unit in the release mode. This allows higher rotational speed change rates, in particular higher than 6,000 rpm/s, to be achieved. Such high rotational speed change rates are particularly suitable for operating the drilling drive arrangement in the release mode. It is preferred that the torque control of the at least two electric motors in the release mode is configured such that the drilling drive arrangement can be controlled synchronously by the at least two electric motors. It is preferable herein if a target torque corresponding to half the total torque of the first and second electric motors is provided for the torque control. This allows the drilling drive arrangement according to the invention to be operated particularly efficiently.

A useful further development of the drilling drive arrangement according to the invention consists in the fact that the at least two electric motors are rotational speed-controlled by the control unit in drilling mode and, in particular, can be controlled in a master-slave operation. It is advantageous if the at least two electric motors can be synchronised with each other in such a way that they drive the drilling drive arrangement with the same torque. Alternatively or in addition to this, it is advantageous if, in master-slave operation, a first electric motor, in particular with an additional control unit, is rotational speed-controlled and a second electric motor is torque-controlled. This allows different drive types of the drilling drive arrangement to be implemented flexibly.

In certain cases, for example if higher torques are required or if the installation space is limited only to smaller motors, three, four or more electric motors can also be arranged.

A further development of the invention consists in the fact that, in the release mode for the rotation-stop movement, a rotation angle, a rotation direction reversal, a number of rotation-stop steps and/or a cycle time can be specified. This allows these parameters to be set individually depending on the respective conditions, such as the type of soil, and thereby achieving particularly efficient releasing of soil from the drilling tool in the release mode. In particular, this allows the release duration or the time duration required for largely complete releasing of the soil material to be kept low, which significantly increases the cost-effectiveness of the drilling process. Similarly, in the release mode, the temporal change or the temporal progression of the rotational speed and/or torque can also be specified as a target value. It is advantageous if the specified release mode parameters can be stored in the control unit and be adjusted as required and requested, for example depending on the soil conditions. A suitable input device, such as a keyboard or touch screen, may be provided for an operator to enter. If individual parameters are entered or changed, the control unit can automatically adjust the other parameters in the selected operating mode to ensure efficient operation of the at least one electric motor.

A particularly useful further development of the invention is that in the drilling mode, a rotational speed can be specified by a machine operator and/or by the control unit. This allows the drilling operation to be flexibly and individually adapted to conditions such as soil conditions and/or drilling depth. This also simplifies the control of the drilling drive arrangement. It is useful if an input device is provided, in particular a mobile computing unit, for the machine operator to enter the rotational speed. In principle, the mobile computing unit can thereby be provided for forwarding control commands to the control unit. It is advantageous if the control unit is configured as a computing unit for processing input data, in particular setpoints in the drilling and/or release mode.

In general, the at least one electric motor can be configured as desired. However, a particularly preferred embodiment of the invention resides, however, in that the at least one electric motor can be controlled by the control unit to operate the electric motor in a recuperation mode for recovering electrical energy in a recuperation mode. In other words, the electric motor can be switched from a drive mode to a recuperation mode and from a recuperation mode to a drive mode by the control unit. It is advantageous if the control unit is configured to operate the electric motor in a recuperation mode depending on the rotational speed and/or torque of the rotary drive. This allows the drilling drive arrangement to be flexibly adapted to changing operating conditions of the drilling rig.

By operating the at least one electric motor in a recuperation mode, energy generated during operation of the drilling drive arrangement can be recovered in an advantageous manner, in particular braking energy which is generated during a rotation-stop movement with or without reversal of the direction of rotation of the drilling tool and is converted into usable or storable electrical energy in the at least one electric motor in recuperation mode.

Thereby, it is particularly preferred that an intermediate circuit for distributing electrical energy as required is connected to the drilling drive arrangement by line, wherein at least one excess energy consumption unit, in particular a brake chopper, is provided for absorbing power peaks of the drilling drive arrangement in drilling and/or releasing operation from the intermediate circuit. The intermediate circuit can here be configured in particular for conducting and distributing direct current. It is particularly advantageous if the intermediate circuit is configured with a supply device for connecting the intermediate circuit to a local power distribution network. The supply device can thereby additionally have a converter device for converting current and/or voltage. It is advantageous if the at least one electric motor comprises an inverter unit for supplying and/or removing electrical energy from the intermediate circuit, wherein the inverter unit is configured for bidirectional conversion of direct current into alternating current. This allows the at least one electric motor to be connected to the intermediate circuit in a particularly efficient manner. The intermediate circuit is in this respect configured to divert excess electrical energy from the at least one electric motor to the at least one excess energy consumption unit in order to prevent in this way excessive loading of electrical components if overvoltages occur.

A particularly reliable embodiment of the invention is achieved in that the at least one excess energy consumption unit is assigned a control system for supplying and discharging electrical energy as required. It is advantageous if the supply and discharge of electrical energy depends on status values, in particular the voltage of the intermediate circuit. This allows overvoltage to be detected at an early stage and to be avoided. In this way, a short-term overvoltage occurring in the intermediate circuit can also be compensated particularly quickly by the control system. The control system can be configured with the control unit for controlling the at least one electric motor, but also with an additional control unit. The control system of the at least one electric motor as well as the excess energy consumption unit can generally be embodied centrally or decentrally with several control units.

According to a development of the invention, it is particularly advantageous that at least one internal rechargeable battery unit is provided for receiving and storing electrical energy and for supplying the at least one electric motor with electrical energy depending on the state of charge of the battery unit. It is advantageous if the battery unit is connected to the intermediate circuit, wherein the battery unit may be configured with or without a converter unit for supplying and/or dissipating electrical energy to the intermediate circuit. It is preferred that the voltage level of the intermediate circuit corresponds to the voltage level of the battery unit depending on the state of charge. It is also preferred here that the battery unit is configured as an excess energy consumption unit to compensate power peaks. This allows the electric motor to be supplied with electrical energy flexibly and as required. The direct connection of the battery unit to the intermediate circuit eliminates the need for additional converter units and thereby costs are reduced.

The drilling drive arrangement according to the invention can be used in a variety of ways. The invention comprises, in particular, a drilling rig for underground construction, with a carrier device, which is preferably configured to be mobile with a chassis, and a mast, which is arranged on the carrier device, wherein a drilling drive arrangement according to the invention is arranged on a drilling drive carriage, which is mounted in particular so as to be displaceable along the mast.

The drilling tool of the drilling rig can preferably be configured as a discontinuous drilling tool, such as an auger or a box drill, which is to be withdrawn from the ground at certain intervals and to be emptied.

The method according to the invention is characterised in that a control unit for controlling the at least one electric motor is configured with a drilling mode for drilling the drilling tool into the ground and with a release mode for releasing soil material from the drilling tool, wherein, in the release mode, the control units automatically control or change the current and/or voltage for the electrical power supply of the at least one electric motor in such a way that the drilling tool repeatedly performs a rotation-stop movement with or without a reversal of the direction of rotation.

The method can be carried out, in particular with the drilling drive arrangement according to the invention described above. The advantages described above can be achieved thereby.

A preferred method variant of the invention is in that at least one excess energy consumption device is provided, wherein the power output from the drilling drive arrangement to the excess energy consumption device in a drilling mode and/or release mode is adjusted depending on a detected limit value. The limit value may comprise electrical condition data, in particular current and/or voltage values of the intermediate circuit and/or of the at least one electric motor. If the detected limit value is exceeded, excess or accumulating electrical energy can be dissipated to the excess energy consumption device, wherein the dissipation of electrical energy can be controlled by the control unit or separately. The limit value can thereby be measured by a measuring device for detecting electrical condition data. This prevents overvoltages from braking processes and with it associated damage.

Another preferred embodiment of the method according to the invention consists in that to adapt a control algorithm to previous and/or current overload condition data of the drilling drive arrangement in order to retain at least one limit value, preferably by means of machine learning, wherein the power dissipation of the drilling drive arrangement is controlled by the control algorithm.

The control algorithm can thereby be implemented in the control unit for controlling the at least one electric motor or separately. The overload condition data of the drilling drive arrangement can preferably comprise current or voltage and can be measured with a measuring device. This makes it possible to adjust the power discharge dynamically and within a short time so that power peaks and overloads of the electrical components are avoided by anticipating the power fed back. This also reduces wear of the affected components. In particular, braking energy generated during a rotation-stop movement with or without reversal of the direction of rotation of the drilling tool can be converted into usable or storable electrical energy in the at least one electric motor in recuperation mode. This power recovery enables energy-efficient releasing operation.

A particularly useful further development of the method according to the invention consists also in the fact that, depending on the power recovery of the at least one electric motor, the power recovery of at least one further power recovery unit is adjusted. This means that when a limit value of the power recovery of the at least one electric motor is exceeded, the power recovery from other machine functions capable of being fed back, in particular the main winch, is blocked or limited. This can prevent in particular the excess energy consumption device and the intermediate circuit from being overloaded due to overvoltages. It is advantageous if the total power recovery sum of the various power recovery units is recorded in real time and, if a limit value is exceeded, the power recovery of certain power recovery units is reduced. This means that, depending on the total power recovery of a first and a second electric motor, the power recovery of the first and/or the second electric motor is adjusted to a setpoint.

The invention is further explained below using preferred exemplary embodiments, which are schematically illustrated in the drawings. The drawings show:

FIG. 1: a side view of the drilling drive arrangement according to the invention;

FIG. 2: a schematic representation of a circuit arrangement according to the invention with an intermediate circuit and possible components;

FIG. 3: a schematic representation of a circuit arrangement according to the invention with additional battery converter units;

FIG. 4: a schematic side view of the drilling drive carriage according to the invention with two electric motors; and

FIG. 5: a schematic representation of the drilling drive carriage according to the invention from behind, with two electric motors.

A drilling drive arrangement 80 according to the invention with a carrier device 12 is shown in FIG. 1. The carrier device 12 can preferably comprise a crawler track as an undercarriage 14, on which a superstructure 16 can be mounted, in particular rotatably. A control device 60 for the drilling drive arrangement 80 can be located in an operating cabin of the superstructure 16. In particular, a mast 20 can be mounted on the superstructure 16, preferably in an adjustable manner, via an linkage mechanism 18, which can have a substantially vertical position during operation.

According to the exemplary embodiment shown, the mast 20 can preferably be configured as a leader 21 with a linear guide 24 on its front side. A drilling drive carriage 38 with a rotary drive 36 can, for example, be mounted so as to be vertically moveable along the linear guide 24. This allows the drilling rig 10 to be embodied as an underground construction machine. The drawing shows an upper position of the rotary drive 36 as well as a lower position with a broken line.

A cable 40 can be guided over a mast head 22 at the upper end of the mast 20, at one end of which a preferably telescopic Kelly bar 32 with an exemplary drilling tool 34 for forming an underground construction tool 30 can be provided. The Kelly bar 32 can be guided by a sleeve-shaped drive wheel of the rotary drive 36 on the drilling drive carriage 38, so that a torque can be transmitted from the rotary drive 36 to the Kelly bar 32, for example via driver bars not shown. The drilling tool 34 for making a borehole in the ground can be arranged at the lower end of the Kelly bar 32. The drilling tool 34 can basically be configured in any way and can, in particular, have a drill auger or a drill bucket.

The cable 40 can be guided from the Kelly bar 32 via deflection rollers 26 on the mast head 22 along the mast 20 up to a cable winch 46 in the superstructure 16. The cable winch 46 is driven by a motor 50, which can also be operated in a recuperation mode. The Kelly bar 32 with the drilling tool 34 can be raised and lowered by means of the cable 40 via the cable winch 46. During lowering, potential energy can be converted into electrical energy by the motor 50 and transferred to an intermediate circuit 98, which will be described in more detail below.

The drilling drive carriage 38 with the rotary drive 36 can be pulled upwards via a further adjusting cable 29 by means of an actuator 28 with a winch on the mast 20. By corresponding driving the actuator 28 in the opposite direction, the drilling drive carriage 38 with the rotary drive 36 can also be lowered downwards. The rotary drive 36 can be formed with at least one electric motor 84, which, in particular converts braking energy, which occurs during a rotation-stop movement with or without reversal of the direction of rotation of the drilling tool 34, into usable or storable electrical energy in a recuperation mode. The actuator 28 can also be equipped with an electric motor (not shown) which, as well as the electric motor 84, can be operated in a recuperation mode. The drilling drive carriage 38 with the rotary drive 36 can also be regarded as part of the underground construction tool 30.

In the exemplary 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 configured as a force measuring bolt through which a cable pull force on the cable 40 can be detected. The force measuring device 62 is connected to the control device 60 on the superstructure 16.

The control device 60 controls the at least one motor 50 for operating the cable winch 46 and preferably also the electric motor 84 for operating the rotary drive 36. The control device 60 can be configured, in particular as a control unit 88.

FIG. 2 schematically shows a circuit arrangement for operating the drilling drive arrangement 80 according to the invention. The circuit arrangement is here configured to supply and remove electrical energy to and from a first electric motor 84 and a second electric motor 86. The first electric motor 84 can preferably be configured to supply and remove mechanical energy to a mechanical consumer unit 125, for example during a braking or lowering process. Similarly, the second electric motor 86 can preferably be configured to supply and remove mechanical energy to a mechanical consumer unit 130. The first electric motor 84 and the second electric motor 86 can each be operated either selectively or in phases in a recuperation or drive mode. For the supply or removal of electrical energy from a DC intermediate circuit 98 as required, a first inverter unit 91 may be assigned to the first electric motor 84 and/or a second inverter unit 93 may be assigned to the second electric motor 86 for example, as shown in FIG. 2. For direct motor control, a first motor control unit 90 can basically be assigned to the first electric motor 84 and a second motor control unit 92 to the second electric motor 86. The motor control can here be carried out, in particular with a control unit as a higher-level control device 88 and the first and second motor control units 90, 92 in a master-slave operation. In general, the control unit 88 can also be configured specifically to directly control the first electric motor 84 and/or the second electric motor 86 of the drilling drive arrangement 80 according to the invention.

As further shown in FIG. 2, additional consumer units 120, such as peripheral devices, can preferably be connected to the intermediate circuit 98 for the demand-based distribution of electrical energy. The intermediate circuit 98 can preferably be configured to carry a direct voltage at a voltage level of approximately 400 V to 800 V. In particular, the intermediate circuit can be configured to carry a voltage level of 750 V.

Furthermore, the intermediate circuit 98, shown schematically in FIG. 2, can be configured with a supply device 104 for supplying and removing electrical energy from an external energy source 106 as required. The external energy source 106 can thereby be configured, in particular as a local energy distribution network, in particular as an alternating voltage network. Preferably, the supply device can have a feed-in device, such as a plug connection. An inverter unit can also be provided for the supply device to convert alternating voltage from a local energy distribution network into direct volt. A control device may be assigned to the supply device 104 to control the inflow and outflow of electrical energy to and from the intermediate circuit 98.

In general, the voltage level and, in particular, the energy distribution in the intermediate circuit 98 can be controlled centrally, for example by the control unit 88. Similarly, the voltage level and the energy distribution in the intermediate circuit 98 can also be controlled decentrally, for example by individual control devices of the components electrically connected to the intermediate circuit. As schematically indicated in FIG. 2, the individual control devices of the electrical components connected to the intermediate circuit 98 and the control unit 88 can be connected via a communication network 134. The control devices in this sense also include, in particular, the first motor control unit 90 and the second motor control unit 92. As shown in FIG. 2, these control units may also include a first battery control unit 94 and a second battery control unit 96, which may be provided for controlling a first battery unit 110 and a second battery unit 112.

The components electrically connected to the intermediate circuit 98 may also include, in particular, an excess energy consumption unit 100 for buffering and smoothing power peaks. The excess energy consumption unit 100 may preferably also have its own control device which is connected to the communication network 134. Excess electrical energy generated by the electric motors can thus be fed, for example, from the intermediate circuit 98 to the excess energy consumption unit 100 and/or the battery units 110, 112.

As can be seen from FIG. 3, a first converter unit 114 can be assigned, in particular to the first battery unit 110 and a second converter unit 116 to the second battery unit 112. This means that the voltage level in the intermediate circuit 98 can be determined independently of the voltage level, in particular the state of charge of the first battery unit 110, and/or the voltage level, in particular the state of charge of the second battery unit 112. This means that the components electrically connected to the intermediate circuit 98 can be operated independently of the voltage level of the first battery unit 110 and/or the voltage level of the second battery unit 112.

FIG. 4 shows a side view and FIG. 5 shows a rear view of the electric rotary drive 36 with a first electric motor 84 and a second electric motor 86 on the drilling drive carriage 38. The rotary drive 36 can preferably be bolted to the drilling drive carriage 38, which can be moved on the mast. The first electric motor 84 and the second electric motor 86 can preferably drive a hollow shaft via a common summation gear, wherein the hollow shaft transmits the drive torque to a drilling tool not shown here.