Construction machine and method for controlling a construction machine

Abstract

The invention relates to a construction machine and a method for controlling a construction machine with a mast, along which a tool is movably mounted, the tool being suspended from a cable which can be actuated to raise and lower the tool by means of a cable winch, which is driven by a hydraulic motor is driven in rotation as a winch drive. The hydraulic motor is driven in a hydraulic circuit by a hydraulic pump, which is designed as a pivotable hydraulic pump, through which a hydraulic flow can be generated in both directions. To control the hydraulic pump, a control device is provided, which is designed to control the hydraulic pump as a function of a predefinable cable tensioning force.

Description

[0001] The invention relates to a construction machine according to claim 1.

[0002] The invention further relates to a method for controlling a construction machine according to claim 9.

[0003] Such a construction machine, designed as a rotary drilling rig, is described, for example, in EP 1 862 636 B1. A winch at the rear of the drilling rig uses a cable, which runs over the top of a mast, to raise and lower a drilling tool, such as a drill bucket or auger. The pulling motion is applied via the winch, while the downward movement is generated by the weight of the tool or by a separate feed system for the rotary drive.

[0004] US Patent 5.63 0.477 discloses a tracked vehicle with a mast extending horizontally forward. A Kelly bar is mounted in a U-shaped clamp at the front end of the mast. The Kelly bar is telescopic and features square, concentric extensions within it.

[0005] The rotary drive is hydrostatically powered by a first hydraulic pump, with torque being transmitted from the hollow drive shaft to the drilling tool. The feed system for the rotary drive, used to move the drive along the mast, has a second hydraulic pump. This pump drives an actuating cylinder or a hydraulic actuator. The drilling tool typically comprises a Kelly bar, which is suspended from the cable running over the mast head. Torque is transmitted from the rotary drive to the Kelly bar and thus to the tool, such as a box drill. A downward feed force can be exerted from the feed system via axial locking pockets in the Kelly bar.

[0006] As the drilling depth increases and the drilling tool moves downwards, it is necessary to advance the cable of the winch using a cable tensioning device while maintaining a predetermined tensioning or retraction force, which usually depends on the type of drilling method.

[0007] One known method is to use a clutch of a free-fall brake to generate a retraction force during the drilling process. The braking torque is generated by an adjustable control pressure. Alternatively, in the case of a hydrostatically driven winch, the working connections of the winch-driving hydraulic motor can be connected by means of a hydraulic circuit to enable a rope tensioning function. The required retraction force is determined by the hydraulic circuit. A hydraulic control system for a winch is described, for example, in EP 1 247 778 B1.

[0008] The invention is based on the Task The basis is to specify a construction machine and a method for controlling a construction machine in which rope tension can be adjusted in a simple and reliable manner over a wide operating range.

[0009] The problem is solved, firstly, by a construction machine with the features of claim 1 and, secondly, by a method with the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims.

[0010] In the construction machine according to the invention, it is provided that the hydraulic motor is driven in a hydraulic circuit by a hydraulic pump, which is designed as a pivotable hydraulic pump, through which a hydraulic flow can be generated in both directions, and that a control device is provided for controlling the hydraulic pump, which is designed to control the hydraulic pump depending on a predefinable rope tension force.

[0011] By using a swiveling hydraulic pump, such as a swashplate pump, a flow rate can be generated in both directions of the hydraulic circuit. This allows the hydraulic motor to be used for both lifting and active lowering, with the winch setting a fixed unwinding speed independent of the attached cable load. This ensures a reliably defined cable tension not only during lifting but also during lowering.

[0012] A further advantage of the invention, particularly compared to free-fall clutches, is that a rope tension force can be freely specified via the control device and the hydraulic pump is driven based on this.

[0013] A preferred embodiment of the invention consists in the control device allowing the swivel angle of the hydraulic pump to be adjusted. By influencing the swivel angle, the hydraulic pump can be continuously adjusted so that virtually any clamping or retraction force can be set and maintained.

[0014] A further advantageous embodiment of the invention lies in the provision of a force measuring device for measuring the cable pull force and in the fact that the force measuring device is connected to the control device for controlling / regulating the hydraulic pump depending on the measured cable pull force values. By measuring the instantaneous cable pull force, the hydraulic pump and thus the hydraulic motor can be controlled by corresponding feedback of the measured cable pull force values.

[0015] In principle, the force measuring device can be designed in any way, in particular performing direct or indirect measurements. A particularly advantageous design involves the force measuring device having a force-measuring bolt on a pulley of the rope or a force-measuring lug on a winch stand of the winch. The pulley can be located, in particular, at the top of the mast. The force-measuring bolt thus allows for a very precise measurement of the instantaneous rope force. The instantaneous rope force can also be determined via a force measuring device on the winch stand, i.e., the bearing frame of a winch drum. The force measuring device can be connected to the control unit via a cable or wirelessly.

[0016] According to a further development of the invention, efficient operation is achieved by making the preset cable tension force variable via the control unit. The control unit can, in particular, include an input unit with which a cable tension force can be preset. A data storage device can also be provided in which preset cable tension forces for specific operating modes of the tool are stored. These preset cable tension forces may have been determined in advance through testing. Additionally or alternatively, the control unit can also include further measuring devices for determining the operating mode of the tool, such as the rotational speed or feed rate, so that the control unit programmatically sets an appropriate cable tension force.

[0017] According to a preferred embodiment of the invention, it is provided that the rope tension force can be changed by the control device depending on adjustment parameters.

[0018] It is particularly preferred that at least one adjustment parameter is selected from the parameters rope speed, feed rate, feed force, and / or operating method, especially an operating mode of a rotary drilling drive. The selection of the adjustment parameters can be carried out manually or automatically by the control unit via appropriate sensors on the construction machine. This ensures that the rope tension can be appropriately controlled and adjusted for the respective operating condition and operating method. This guarantees safe and trouble-free operation of the construction machine and also prevents excessive rope wear.

[0019] Furthermore, according to the invention, it is preferred that the hydraulic circuit is closed and equipped with a diverter valve through which hydraulic fluid can be discharged in a controlled manner for cooling. During intensive operation, the temperature of the hydraulic fluid in the hydraulic circuit can rise. To prevent excessive heating, a diverter valve is provided through which hydraulic fluid can be discharged in a controlled manner. Control can be achieved by means of a temperature sensor or via a predefined control program by the control unit. For cooling, hydraulic fluid can be directed into a receiving tank, which may preferably be equipped with a separate cooling device. Corresponding to the discharge of hydraulic fluid via the diverter valve, cool hydraulic fluid is returned to the hydraulic circuit via a corresponding supply valve.

[0020] In principle, construction machinery can be designed for a wide variety of uses.

[0021] According to the invention, the construction machine is designed as a drilling rig, on the mast of which a rotary drilling drive is adjustably mounted and can be moved along the mast by means of at least one actuator. As described in the introduction to the prior art, the drilling rig can have a first hydraulic drive for supplying power to the rotary drilling drive and a second hydraulic drive as an actuator for a feed system. The feed system uses hydraulic cylinders or a servo motor to axially move a feed carriage with the rotary drilling drive along the mast. In particular, the actuator of the feed system can apply a downward feed force to the tool. The tool can be a conventional rotary drilling tool, in particular a drill auger, a box drill, a displacement drill, or another drilling device.

[0022] In the inventive method for controlling a construction machine, the hydraulic motor is driven in a hydraulic circuit by a hydraulic pump, which is designed as a pivotable hydraulic pump capable of generating a hydraulic flow in both directions. The hydraulic pump is controlled by a control device depending on a predefinable cable tension force. This method can be used, in particular, for controlling the aforementioned construction machine. The advantages described above are thus realized.

[0023] The invention is further described below with reference to preferred embodiments, which are schematically illustrated in the figures. The figures show: Fig. 1: a schematic view of a construction machine according to the invention and Fig. 2: a schematic hydraulic circuit diagram for a construction machine according to the invention.

[0024] According to Fig. 1A construction machine according to the invention is shown as a drilling rig 50 with a mast 52, along which a feed carriage 59 with a rotary drilling drive 58 is mounted vertically displaceable on a mast guide (not shown). For the vertical movement of the feed carriage 59, a hydraulic cylinder is arranged as an actuator 66, which is driven by a first hydraulic drive 71.

[0025] The rotary drilling drive 58 has a hollow shaft through which a Kelly bar 56 projects in a known manner, and a box drill bit is attached to the lower end of the Kelly bar as a tool 54. A torque and a downward feed force can be applied from the rotary drilling drive 58 and at the feed slide 59 to the Kelly bar 56 and thus to the tool 54 via drive strips and locking pockets (not shown). The hydraulic rotary drilling drive 58 is supplied with energy via a second hydraulic drive 72, i.e., a hydraulic pump, in a hydraulic circuit.

[0026] The Kelly bar 56 is suspended in a known manner from a rope 64, which is led via a first deflection pulley 46 and a second deflection pulley 47 at a transverse masthead 53 of the mast 52 to a winch 1. The winch 1 comprises a rope drum 60 rotatably mounted in a winch stand 62. The rope drum 60 of the winch 1 is driven via a drive shaft by a hydraulic motor 3, which is connected in a hydraulic circuit to a hydraulic pump 10.

[0027] The hydraulic pump 10, as well as the first hydraulic drive 71 designed as a hydraulic pump for the feed system and the second hydraulic drive 72 for the rotary drilling drive 58 are supplied with energy by a diesel engine 70 via a gearbox 75.

[0028] To ensure the desired cable tension during the lifting and lowering of the tool 54, the hydraulic pump 10 is designed to swivel, in particular as a swashplate hydraulic pump. By means of the swiveling hydraulic pump 10, a hydraulic flow can be generated in both directions of the hydraulic circuit 20, so that the hydraulic motor 3 and thus the winch 1 can be operated in both directions of rotation.

[0029] A control unit 40 is provided for controlling the winch 1, which is operatively connected to the hydraulic pump 10. According to a first control variant, a target cable tension force can be entered into the control unit via a data input device. Based on the specified cable tension force, the hydraulic pump 10, and thus also the winch 1, is controlled both when raising and lowering the tool 54.

[0030] In the illustrated embodiment according to Fig. 1 For the purpose of implementing control with the control unit 40, a force measuring device 44 with a force measuring bolt is arranged on the first deflection pulley 46. This allows the tensile force on the rope 64 to be measured directly, whereby the measured rope tension values ​​are transmitted to the control unit 40 for controlling the hydraulic pump 10 according to a further control variant.

[0031] In the illustrated embodiment, the control unit 40 is also connected to further sensor devices on the drive shaft of the winch 1, the actuator 66 of the feed system for the rotary drilling drive 58, and on the rotary drilling drive 58 for controlling the hydraulic pump 10. A corresponding program is stored in the control unit 40, which uses the transmitted measurement data to determine an appropriate cable tension force and to control compliance with this value.

[0032] According to the hydraulic circuit diagram Fig. 2, which refers in particular to the construction machine after Fig. 1 The winch 1, which operates the tool 54, is driven by a hydraulic motor 3 with adjustable displacement and capable of rotation in two directions. The hydraulic motor 3 operates in a closed hydraulic circuit supplied by an adjustable hydraulic pump 10. The direction of rotation of the hydraulic motor 3 is determined by the delivery direction of the hydraulic pump 10. Since the hydraulic oil in the closed circuit heats up due to friction losses, a specific quantity of oil can be continuously or at predetermined times diverted from the closed hydraulic circuit via a diverter valve 9 and supplied to a hydraulic tank. The contents of the hydraulic tank can be cooled. The resulting loss of hydraulic oil is compensated for by an integrated feed pump.

[0033] A first electroproportional 3-2-way valve 5 uses a magnetic adjustment to set the swivel angle of the hydraulic motor 3 between a minimum and a maximum displacement volume. Furthermore, a second 3-2-way valve 4 provides pressure cut-off for adjusting the swivel angle of the hydraulic motor 3.

[0034] A pressure switch 6 indicates a saturated circuit to the control unit. If this is not the case, for example due to a hose rupture, the control unit does not enable the winch function. In this case, a holding or parking brake 2 remains closed. A check valve 18 is designed to engage the parking brake 2 on the winch 1 in the event of a sudden pressure loss due to a line rupture. A shuttle valve 7 with an upstream controlled valve 8 is used to release and vent the parking brake 2 with a specific delay during normal operation, ensuring slip-free load transfer between the parking brake 2 and the hydraulic motor 10, and vice versa. A pressure sensor 17 serves as the input signal transmitter for the control unit.

[0035] The hydraulic pump 10, designed as a pivoting swashplate pump, is controlled via a control valve 11, with a control piston 16 being directly mechanically connected to the hydraulic pump 10. A first pressure relief valve 13 protects the high-pressure side of the hydraulic pump 10 against maximum pressure. A second pressure relief valve 14 cuts off the pressure in the hydraulic pump 10 at maximum operating pressure. A third pressure relief valve 15 protects the hydraulic pump 10 on the low-pressure side, analogous to the first pressure relief valve 13. The pilot control of the arrangement is operated via a supply pressure 12 of 35 bar.

Claims

1. Construction machine configured as a drilling apparatus (50), having a mast (52) along which a tool (54) is supported in a movable manner, wherein the tool (54) is suspended on a rope (64) which, for the purpose of lifting and lowering the tool (54), can be actuated by means of a rope winch (1) that is driven in a rotating manner by a hydraulic motor (3) as a winch drive, wherein a feed carriage (59) with a rotary drill drive (58) is mounted on a mast guide along the mast (52) so as to be vertically movable and can be moved via an actuator (66), wherein a hydraulic cylinder is arranged as an actuator (66) for the vertical movement of the feed carriage (59), which is driven by a first hydraulic drive (71), wherein the hydraulic motor (3) is driven in a hydraulic circuit (20) by a hydraulic pump (10), that is designed as a bidirectional hydraulic pump (10) by which a hydraulic flow can be generated in both directions, and wherein for the control of the hydraulic pump (10) a control means is provided which is designed to control the hydraulic pump (10) depending on a predeterminable rope tensioning force.

2. Construction machine according to claim 1, characterized in that by the control means (40) a pivot angle of the hydraulic pump (10) is adjustable.

3. Construction machine according to claim 1 or 2, characterized in that a force measuring means (44) for measuring the rope pull force is provided and, in that the force measuring means (44) is connected to the control means (40) for controlling / regulating the hydraulic pump (10) depending on measured rope pull force values.

4. Construction machine according to claim 3, characterized in that, that the force measuring means (44) has a force measuring bolt on a deflection pulley (46) of the rope (64) or a force measuring strap on a winch block (62) of the rope winch (1).

5. A construction machine according to any one of claims 1 to 4, characterized in that the predeterminable rope tensioning force can be changed by the control means (40).

6. Construction machine according to claim 5, characterized in that by the control means (40) the rope tensioning force can be changed depending on adjustment parameters.

7. Construction machine according to claim 6, characterized in that at least one adjustment parameter is selected from the parameters rope speed, feed speed, feed force, and / or working method, in particular an operating mode of a rotary drill drive (58).

8. Construction machine according to any one of claims 1 to 7, characterized in that the hydraulic circuit (20) is closed and designed with a branch-off valve (9), via which hydraulic fluid for cooling can be discharged in a controlled manner.

9. A method for controlling a construction machine according to any one of claims 1 to 8, having a mast (52) along which a tool (54) is supported in a movable manner, wherein the tool (54) is suspended from a rope (64) which, for the purpose of lifting and lowering the tool (54), is actuated by means of a rope winch (1) that is driven in a rotating manner by a hydraulic motor (3) as a winch drive, wherein a feed carriage (59) with a rotary drill drive (58) is mounted on a mast guide along the mast (52) so as to be vertically movable and can be moved via an actuator (66), wherein a hydraulic cylinder is arranged as an actuator (66) for the vertical movement of the feed carriage (59), which is driven by a first hydraulic drive (71), wherein the hydraulic motor (3) is driven in a hydraulic circuit (20) by a hydraulic pump (10) that is designed as a bidirectional hydraulic pump (10), by which a hydraulic flow can be generated in both directions, and wherein the hydraulic pump (10) is controlled by means of a control means (40) depending on a predeterminable rope tensioning force.

Images