APPARATUS, ROCKL DRILLING RIG AND METHOD FOR ROCK DRILLING

Abstract

An apparatus, rock drilling rig and method for rock drilling includes a turning device for moving a drilling tool around longitudinal axis of the tool. The turning movement is controlled by an alternating turning system so that direction of turning movement is continuously reversed to first and second turning directions. The turning angle of the tool is restricted and a safety system (is configured to monitor the operation and to ensure that a predetermined turning angle is not exceeded.

Claims

1. An apparatus for rock drilling comprising: a rock drilling machine and a longitudinal drilling tool connectable to the rock drilling machine; and the rock drilling machine including a turning device (TD) for moving the drilling tool around a longitudinal axis of the drilling tool; at least one alternating turning system for controlling the turning device to reverse direction of movement of the drilling tool repeatedly and thereby generating allowed predetermined turning movements in a first turning direction and correspondingly in a second turning direction; and at least one separate safety system configured to secure independently relative to the turning device a magnitude of realized turning movements that are always below the allowed predetermined turning movements.

2. The apparatus as claimed in claim 1, wherein the safety system is configured to monitor operation of the alternating turning system, the safety system being configured to stop operation of the turning device in response to detected deviation in the operation of the alternating turning system.

3. The apparatus as claimed in claim 2, wherein the turning device is a pressure medium operated turning actuator, the alternating turning system including at least one control valve for controlling pressure prevailing in pressure medium ports of the turning device, whereby the turning direction of the turning device is reversed in response to operation of the control valve, and wherein the safety system of the apparatus is configured to monitor operation of the control valve.

4. The apparatus as claimed in claim 3, wherein the safety system includes at least one electrical monitoring element arranged in connection with the control valve for monitoring operation of the control valve.

5. The apparatus as claimed in claim 1, wherein the turning device of the rock drilling machine is a pressure medium operated motor.

6. The apparatus as claimed in claim 1, wherein the turning device of the rock drilling machine is a hydraulic motor, the turning device being connected to a hydraulic circuit by at least one pressure medium duct, the alternating turning system including at least one control valve for controlling pressure medium flow in the mentioned pressure ducts, the safety system including at least one additional second hydraulic motor connected to the at least one pressure medium duct, whereby the second hydraulic motor is series-connected with the hydraulic turning device and a magnitude of the realized turning movements of the additional second hydraulic motor is mechanically limited, whereby the additional second hydraulic motor is configured to prevent the turning device from exceeding allowed predetermined turning movements.

7. The apparatus as claimed in claim 1, wherein the safety system includes at least one sensing device for detecting a turning angle of the produced turning movement, which is directed to the drilling tool, the safety system being provided with at least one maximum turning angle limit and the safety system being configured to stop the turning in response to detected exceed of the maximum turning angle limit.

8. The apparatus as claimed in claim 1, wherein the safety system includes at least one sensing device for detecting realized turning movement of the drilling tool or shank, the safety system being configured to calculate a magnitude of realized turning angle of the drilling tool on a basis of the detection data the safety system being provided with at least one maximum turning angle limit and the safety system is configured to stop operation of the turning device in response to detected exceed of the maximum turning angle limit, whereby the magnitude of the realized turning movement of the drilling tool is always below the allowed predetermined turning movements.

9. The apparatus as claimed in claim 1, wherein the safety system includes at least one sensing device mounted to the rock drilling machine for detecting realized turning movement of the turning device, the safety system being configured to calculate a magnitude of realized turning angle of the drilling tool on a basis of the detection data of the rock drilling machine, the safety system being provided with at least one maximum turning angle limit and the safety system is configured to stop operation of the turning device in response to detected exceed of the maximum turning angle limit, whereby the magnitude of the realized turning movement of the drilling tool is always below the allowed predetermined turning movements.

10. The apparatus as claimed in claim 1, wherein the turning device of the rock drilling machine is a hydraulic motor, the turning device being connected to a hydraulic circuit by pressure ducts, the alternating turning system having at least one control valve, the safety system including at least one dosing cylinder mechanism connected to the pressure ducts of the hydraulic motor, wherein the control valve is configured to control reciprocating motion of the dosing cylinder mechanism (30); and each stroke of the dosing cylinder mechanism is configured to dose limited volume of hydraulic fluid to the hydraulic motor, whereby the dosed batches of hydraulic fluid are configured to generate limited turning movements for the hydraulic motor.

11. The apparatus as claimed in claim 1, wherein the turning device of the rock drilling machine is a pressure medium operated turning actuator connected to a pressure medium system by means of pressure medium lines, the safety system including at least one sensing device configured to sense properties of pressure medium affecting in at least one pressure medium line connected to the pressure medium operated turning actuator and the safety system is configured to monitor the operation of the alternating turning system by means of the sensing data.

12. The apparatus as claimed in claim 11, wherein the safety system includes at least one flow sensing device arranged to detect pressure medium flow conveyed to the turning actuator and the safety system is configured to monitor the operation of the alternating turning system by means of the sensed flow data.

13. The apparatus as claimed in claim 11, wherein the safety system includes at least one pressure sensing device arranged to detect pressure in at least one pressure medium line of the turning actuator and the safety system is configured to monitor the operation of the alternating turning system by means of the sensed pressure data.

14. A rock drilling rig, comprising: a movable carrier; and at least one drilling boom provided with at least one drilling unit having a rock drilling machine and a feed device for moving the rock drilling machine, the rock drilling machine including a turning device for moving the drilling tool around a longitudinal axis of the drilling tool, at least one alternating turning system for controlling the turning device to reverse direction of movement of the drilling tool repeatedly and thereby generating allowed predetermined turning movements in a first turning direction and correspondingly in a second turning direction, and at least one separate safety system configured to secure independently relative to the turning device a magnitude of realized turning movements that are always below the allowed predetermined turning movements.

15. A method for rock drilling, wherein drill hole is drilled by a rock drilling machine and a drilling tool connected to the rock drilling machine, the method comprising: providing a rock drilling machine a turning device to turn the drilling tool around a longitudinal axis of the drilling tool in a turning movement; reversing direction of the turning movement of the drilling tool repeatedly whereby the drilling tool is turned alternately in a first turning direction and correspondingly is a second turning direction; and securing by at least one separate safety system and operationally independently relative to the turning device, wherein a magnitude of realized turning movement in the first turning direction and the second turning direction is always below allowed predetermined turning movements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0075] FIG. 1 is a schematic side view of a rock drilling rig for surface work sites and arranged to implement the disclosed apparatus and method.

[0076] FIG. 2 is a schematic side view of a rock drilling unit provided with a turning device and an alternating turning system for producing repeatedly reversing turning movements.

[0077] FIG. 3 is a schematic diagram presenting elements and features of the disclosed apparatus and examples of gathering sensing data for a safety system.

[0078] FIG. 4 is a schematic diagram presenting alternative turning devices suitable to be used for turning a drilling tool in accordance with the disclosed solution.

[0079] FIG. 5 is a schematic diagram presenting alternative embodiments of an alternating turning system and its control means.

[0080] FIG. 6 is a schematic diagram presenting alternative ways for a safety system to monitor operation of an alternating turning system.

[0081] FIG. 7 is a schematic diagram presenting ways for a safety system to monitor realized alternating turning movements generated by a turning device.

[0082] FIG. 8 is a schematic diagram presenting features relating to structural differences of different type of turning devices, and their structural capability to generate rotation.

[0083] FIG. 9 shows schematically a hydraulic circuit provided with a rock drilling machine comprising a main hydraulic motor serving as a turning device, and wherein a safety system includes an additional second hydraulic motor being series-connected with the main hydraulic motor.

[0084] FIGS. 10a to 10d show schematically, alternative safety systems for securing that magnitude of the generated turning movement is always limited.

[0085] FIG. 11 shows schematically a hydraulic circuit provided with a dosing cylinder mechanism for providing a turning device with dosed pressure fluid batches causing alternating turning movements in both turning directions.

[0086] FIGS. 12a-12d show schematically a safety arrangement wherein a drilling tool is provided with a monitoring band comprising remote readable markers, which are located at a sensing area and are configured to generate detection signals when the drilling tool operates properly at the desired turning range.

[0087] FIG. 13 shows schematically a mechanical safety arrangement wherein a gear transmission is provided with an incomplete gear tooth system, whereby the transmission is not capable to transmit rotation to a drilling tool.

[0088] For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements.

DETAILED DESCRIPTION

[0089] FIG. 1 shows a rock drilling rig 1 including a movable carrier 2, one or more drilling booms 3 and drilling units 4 arranged in the drilling booms 3. The drilling unit 4 includes a feed beam 5 on which a rock drilling machine 6 can be moved by means of a feed device 7. Further, the drilling unit 4 includes a drilling tool 8 with which impact pulses generated by an impact device of the rock drilling machine 6 are transmitted to the rock to be drilled. The rock drilling machine 6 is also provided with a turning device for moving the drilling tool 8 around longitudinal axis of the drilling tool during the drilling. The turning device is controlled to reverse direction of movement of the drilling tool repeatedly, as it is indicated by arrows and a reference numeral T. In some drilling techniques the drilling may be executed without providing the drilling tool with impact pulses, whereby the drilling machine 6 is then without any impact device.

[0090] The rock drilling rig 1 may include one or more control units CU1, which may be configured to control an alternating turning system for providing the repeatedly reversing turning motion T for the drilling tool 8. Alternatively, the alternating turning system may be a pressure medium or electrically controlled control valve arranged to control a pressure fluid operated turning device. Thus, the alternating turning movement may be controlled under a control of a software program and other electrical control means, or by means of hydraulic or pneumatic control means.

[0091] The on-board control unit CU1 may also be configured to operate as a part of a safety system, which safety system is configured to secure that magnitude of the realized turning movements T is always below an allowed predetermined value. Then, the control unit CU1 may be provided with a safety software program. The drilling unit 4 may be provided with one or more sensing devices SD1-SD3 for monitoring the realized turning movements of the tool 8, a shank 9 or inner elements of the rock drilling machine 6, for example. Produced sensing data of the sensing devices SD may be transmitted to the control unit CU1 and may be processed therein. In case the safety system detects that the turning movement exceeds set maximum limit values, then the operation of the drilling machine 6 is stopped.

[0092] Alternatively, the safety system may include a control unit CU2 or a suitable electrical device of its own. The dedicated control unit CU2 may be located on the carrier, or it may be a device external to the rock drilling rig 1. The dedicated control unit CU2 may communicate with the control unit CU1 of the rock drilling rig for receiving sensing data and transmitting control data for triggering an emergency stop. Thus, the alternating turning system and the safety system may be controlled by means of the main control unit CU1 of the rock drilling rig, or alternatively the systems may have one shared control unit or one or more dedicated control units of their own. Further, herein the term control unit may refer to any one of the control units and corresponding electrical control devices suitable for processing the sensing data and executing the defined actions.

[0093] As can be noted in FIG. 1, there is no need to use protection cages around the drilling tool 8 and the rock drilling machine 6 because the disclosed alternating turning system generates repeatedly reversing turning movement for the drilling tool 8 instead of continuous rotation, and because the safety system secures proper operation of the apparatus. Due to this, visibility to the drilling position is good and the drilling unit has smaller outer dimensions and weight.

[0094] FIG. 2 discloses a rock drilling unit 4 having a rock drilling machine 6, which is provided with a hydraulically operated turning device TD and an alternating turning system ATS for controlling the turning device TD. The rock drilling unit 4 further includes a safety system SS for securing the operation of the rock drilling machine 6. The turning device TD may be a hydraulic motor 15 connected to a hydraulic system 10 having pressure medium ducts 11 or fluid ducts, a pressure source 12 and a tank 13. The alternating turning system ATS may comprise a control valve 14 connected to the hydraulic system 10 and being arranged to change direction of pressure medium in pressure ports of the hydraulic motor 15. The control valve 14 may be controlled by means of a control unit CU of the rock drilling rig, for example. The control valve 14 may move linearly between at least two control positions, as it is indicated by means of an arrow in FIG. 2, or in an alternative construction the valve may turn between the control positions. When the control valve 14 changes its control position repeatedly, the turning device TD generates reversing turning motion. In other words, the control valve 14 continuously changes the turning direction of the turning device TD and a drilling tool 8.

[0095] The safety system SS may include one or more movement or position sensing devices SD4 for detecting proper movement or position of the control valve 14. Thus, the sensing device SD4 may monitor working cycle of the control valve 14. Alternatively, or in addition to, pressure or flow sensing devices SD5 and SD6 may be arranged to pressure ports of the hydraulic motor, or to pressure ducts controlled by the control valve 14.

[0096] By means of the sensing devices SD5 and SD6 properties and variations of hydraulic fluid in the controlled pressure lines may be detected and proper operation may be determined based on the sensed data. Further, one or more sensing devices SD7 may be arranged to monitor realized turning movement of the hydraulic motor 15, or properties of pressurized fluid inside the hydraulic motor 15. It is also possible to monitor realized turning movements by means of sensing devices SD1-SD3 in a similar manner as in FIG. 1. The sensing device SD3 may be arranged to detect movement of a transmission element of the rock drilling machine 6, for example. Thus, the safety system SS may includes one or more sensing devices SD and there are several alternative ways to monitor proper operation of the rock drilling machine and the alternating turning system ATS.

[0097] The sensing data generated by the one or more sensing devices SD1-SD7 may be transmitted to the control unit CU of the safety system SS. The control unit CU determines whether the turning device TD and the alternating turning system ATS operates properly, and if defects are noted, the system controls one or more emergency stops ES for stopping the operation of the turning device TD. In FIG. 2 the emergency stop ES may comprise at least one valve configured to prevent pressure medium to flow in the pressure medium ducts 11 when being actuated.

[0098] FIG. 3 is a schematic diagram presenting the already disclosed features of FIGS. 1 and 2 in a more general concept. The safety system SS may include a control unit CU or electrical control device of its own whereby it may be an independent device relative to the control unit of the rock drilling rig. The safety system SS includes input means 16 for feeding sensing data, software programs, control principles and turning angle limit values, for example. The safety system also includes one or more processors 17 for executing input software programs, for making needed calculations and for producing control commands. An operator of the rock drilling rig may be provided with needed information by means of a display device, indicator lamp or corresponding indicating device 18, whereby the operator is aware of the operational status of the disclosed apparatus. The safety system SS may actuate an emergency stop ES for preventing transmitting operating power to the turning device TD. When the turning device is fluid operated the emergency stop ES may be a valve, and when the turning device is electrically operated, the emergency stop may be an electrical switch, for example.

[0099] FIG. 4 is a schematic diagram presenting some alternative turning devices TD suitable to be used for turning a drilling tool in accordance with the disclosed solution. The turning device TD may be an electrically operated motor or actuator, or alternatively, it may be a pressure fluid operated actuator such as hydraulic or pneumatic motor or cylinder.

[0100] FIG. 5 is a schematic diagram presenting alternative embodiments of an alternating turning system. The alternating turning system ATS may have an electrical control element, which may control operation of an electrical turning device. The electrical control element may be a switch, for example, and may be controlled by a software program executed in a control unit. Alternatively, the alternating turning system ATS may comprise a hydraulic or pneumatic control valve 14, which is configured to control pressure medium flows. The control valve 14 may be pressure controlled or electrically controlled in order move the valve between control positions.

[0101] FIG. 6 is a schematic diagram presenting alternative ways for a safety system to monitor operation of an alternating turning system. As it is disclosed already above, the safety system may include sensing devices for detecting physical position of a control valve and/or sensing devices for monitoring prevailing pressures and flows of control fluid directed to a fluid operated control valve of the alternating turning system. Further, the monitoring may be executed without sensing devices when the alternating turning system is controlled by a software program executed in a control unit of the alternating turning system. Then, the safety system may monitor the execution of the software program and the operation of the control unit.

[0102] FIG. 7 is a schematic diagram presenting some feasible ways for a safety system to monitor realized alternating turning motion generated by a turning device. As it is disclosed in connection with the previous figures, the safety system may includes one or more sensing devices for sensing magnitude of the realized turning movement of a drilling tool, a shank and/or a turning device machine or transmission component. A further alternative is to generate and receive detection signals when the drilling tool or any other component turned by means of the turning device is being turned inside an allowed predetermined turning area. This solution is disclosed in more detailed in connection with FIGS. 12a-12d.

[0103] FIG. 8 is a schematic diagram presenting in a general way some features relating to structural differences of different type of possible turning devices. The rock drilling machine may be provided with a turning device an internal structure of which only allows generating limited turning angles without rotation. The turning device may also be provided with transmission means, which are capable to transmit only movements with limited turning movements. Thus, the turning device may be itself safe regarding the rotation. However, in case the turning device is structurally capable to generate rotation, the limited turning movement may be executed by controlling, by means of the alternating turning system, the turning device to only perform limited movements. Alternatively, or in addition to, mechanical stoppers may be utilized for limiting the turning movements. The mechanical stopper may be considered to operate as a mechanical safety system alone or together with an electrical safety systems provided with electrical sensing, processing and actuation means.

[0104] FIG. 9 discloses a hydraulic rock drilling machine 6 connected to a hydraulic circuit 10 having fluid ducts 11a and 11b, pressure medium source 12 and a tank 13. A turning device TD of the rock drilling machine 6 is a first hydraulic motor 15 connected to the fluid ducts 11a and 11b. An alternating turning system ATS includes a control valve 14 for controlling direction of pressure medium flows in the fluid ducts 11a and 11b. A safety system SS includes an additional second hydraulic motor 19 connected to the fluid duct 11b. The second hydraulic motor 19 is series-connected with the first hydraulic motor 15, whereby both hydraulic motors 15, 19 operate simultaneously. Hydraulic volume of the second hydraulic motor 19 may be set according to hydraulic volume of the first hydraulic motor 15 and transmission means of the rock drilling machine, whereby turning movements of the second hydraulic motor 19 and the drilling tool 8 have the same magnitude.

[0105] A magnitude of the realized turning movements of the second hydraulic motor 19 may be limited by a mechanical stopper 20, which may be arranged on a turning element 21, such as an axle. Around the turning element 21 may be stopping surfaces 22, or corresponding mating elements, for limiting the turning motion of the stopper 20. Thus, the disclosed mechanical stopper system stops the second hydraulic motor 19 at the extreme positions of the movement range set by the stopping surfaces 22, where after no hydraulic fluid flows through the second hydraulic motor 19. Thereby, the fluid duct 11b is blocked and the first hydraulic motor 15 is also stopped. It can be considered that the second hydraulic motor 19 doses hydraulic fluid batches though it and thereby have effect on the first hydraulic motor 15 in both turning directions. By means of the control valve 14 direction of fluid flow in the hydraulic circuit 10 and operating direction of the hydraulic motors 15, 19 may be reversed. Between the fluid ducts 11a, 11b may be an anticavitation element 23 for preventing cavitation of the hydraulic pumps 15, 19 by allowing in special situations fluid flow through the cavitation element 23.

[0106] Further, in connection with the stopping surfaces 22 may be limit switches or sensing devices SD8, SD9 for sensing the approaching stopper 20 already before it contacts against the stopping surfaces 22. Produced sensing data is communicated to a control unit CU of the safety system SS, which may generate control data for controlling the control valve 14 of the alternating turning system ATS. Thus, the disclosed system in connection with the second hydraulic motor 19 may be utilized to produce control data for the control valve 14, whereby during normal operation no mechanical stopping occurs. Instead, the second hydraulic motor 19 is stopped hydraulically. The second hydraulic motor 19 may serve as a turning dosing mechanism for allowing batches of fluid to flow in the hydraulic system 10. The control valve 14 changes the direction of the flow in the hydraulic circuit 10 repeatedly. In other words, the stopper 20 is used to monitor the realized turning movements and the monitoring data is utilized for controlling the alternating turning system ATS. In case the alternating turning system ATS or electrical components of the safety system SS fail, then the mechanical stopping means 20, 22 of the safety system SS prevent oversized turning movements. Further, the safety system SS may also comprise emergency switches ES, such as emergency valves, for shutting the fluid ducts 11a, 11b in case of detected failures in the safety system SS.

[0107] FIGS. 10a to 10d disclose alternative safety systems for securing that the turning movement generated by a turning device is limited. In FIG. 10a a turning element 24 is provided with a mechanical stopping system having a stopper 20 on the turning element 24 and stopping surfaces 22 around the turning element. The turning element 24 may be a drilling tool, shank, or a machine component of the rock drilling machine or transmission system. A further possibility is to arrange an auxiliary component provided with the mechanical stopping system between the rock drilling machine and the drilling tool.

[0108] The arrangement of FIG. 10b differs from the one shown in FIG. 10a in that the stopping surfaces 22 are substituted by safety wires 25. When the stopper 20 meets the safety wire 25, this can be sensed by a switch or sensing device and the safety system may stop the turning device. Further, in FIG. 10c the safety wires of FIG. 10b are substituted by limit switches 26, which are actuated by the stopper 20 in case of exceed of set maximum turning angle value. In FIG. 10d it is disclosed a so called yo-yo-type safety device comprising a special switch 27, which is connected to the turning element 24 by means of a bendable wire 28 or strip of a rotatable reel 29. As the turning element 24 is turned by the turning device, the bendable wire 28 tightens and causes force effect for the switch 27. Exceeding of the limited turning movements are arranged to cause the switch 27 to be triggered and the operation of the turning device is then stopped. The length of the wire 28 is dimensioned so that the desired limited turning movement is allowed without causing the switch 27 to be triggered.

[0109] FIG. 11 discloses a hydraulic circuit 10 provided with a dosing cylinder mechanism 30 for providing a turning device TD with dosed pressure fluid batches causing alternative turning movement in both turning directions. The dosing cylinder mechanism 30 includes a working cylinder 31 and a dosing cylinder 32 connected to move together. The working cylinder 31 is controlled by means of a control valve 14 of an alternating turning system ATS to execute reciprocating working cycle. Each stroke of the working cylinder 31 causes the dosing cylinder 32 to dose limited volume of pressurized fluid to a hydraulic motor 15 serving as a turning device TD. The dosed batches of pressurized fluid may allow only limited turning movements to be generated by means of the turning device. Thus, the dosing cylinder mechanism 30 serves as a hydraulic safety system SS.

[0110] In FIG. 11 valve means 33, such as one-way valves, allow pressure fluid to be fed on both cylinder spaces of the dosing cylinder 29 so that pressure in the system is maintained. Leakage flows of the hydraulic motor 15 may be directed to a tank 13b. The hydraulic circuit 10 may also include a pressure relief valve 34 for allowing by-pass flow when pressure in the hydraulic system exceeds a set magnitude.

[0111] FIGS. 12a-12d disclose a safety arrangement wherein a drilling tool 8 is provided with a monitoring band 35 comprising remote readable markers 36, which are located at a sensing area 37 and are configured to generate detection signals when the drilling tool 8 operates properly at the desired turning range. Safety system SS includes a sensing device SD10 for detecting the markers 36 of the monitoring band 35. In FIGS. 12b and 12d the markers 36 of the sensing area 37 move together with the drilling tool 8 the alternating predetermined angular turning movement and detection signal is generated. In case the turning of the drilling tool 8 exceeds the allowed turning angle, then a non-sensing area 38 with no markers 36 becomes at the sensing device SD10 and then no detection signal is generated. This is disclosed in FIG. 12d. In other words, exceed of the allowed turning angle terminates generation of detection signals. Information of the missing detection signal is transmitted to a control unit CU of the safety system SS, which may actuate an emergency stop ES for stopping the turning.

[0112] An alternative solution for the use of the monitoring band 35 is that the sensing device SD10 detects edges 39 or other surface properties or shapes of the drilling tool 8 and the control unit CU determines the turning movements on the basis of that data.

[0113] FIG. 13 shows schematically an additional safety system SS wherein a gear transmission 40 is provided with an incomplete gear tooth system, whereby the transmission 40 is not capable to transmit rotation to a drilling tool in any situation. A turning device TD is controlled by means of an alternating turning system ATS to generate repeated limited turning movements, which are transmitted via the gear transmission 40 forwards. If the alternating turning system ATS fails, then the transmission 40 prevents mechanically oversized turning movements. The transmission may have a first gear wheel 41 and a second gear wheel 42, which both have toothed gear surfaces 43 and 44. The second gear wheel 42 includes a non-operational area or section 45, which is without proper teeth. The non-operational area 45 may comprise an open space 46, such as a cutting or cavity, incompletely manufactured gear teeth or a solid outer surface without any teeth.

[0114] Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.