Mining or construction vehicle and a hydraulic cylinder conduit enclosing a conduit arrangement

1. An extendable boom comprising at least a first telescopic section and a second telescopic section, wherein the first telescopic section and the second telescopic section extend in a longitudinal direction, wherein the first telescopic section is arranged to be connected to a mining or construction vehicle and a hydraulic device is arranged to be connected to a mounting device in connection to a free end of the second telescopic section, wherein the hydraulic device is a hydraulic percussive drilling machine, wherein at least one hydraulic conduit for supply of hydraulic fluid to the hydraulic device connected to the mounting device is arranged inside the extendable boom, wherein in order to allow the at least one hydraulic conduit to rotate with a rotation of a rotation device, a swivel arrangement is arranged, wherein the at least one hydraulic conduit for the supply of the hydraulic fluid to the hydraulic device is arranged inside a hydraulic cylinder, and wherein the hydraulic cylinder is arranged inside the extendable boom.

2. The extendable boom according to claim 1 , wherein the at least one hydraulic conduit is arranged through the free end of the second telescopic section of the extendable boom.

3. The extendable boom according to claim 2 , wherein the at least one hydraulic conduit extends substantially in parallel with the extendable boom in the longitudinal direction out from the free end of the second telescopic section of the extendable boom.

4. The extendable boom according to claim 1 , wherein the at least one hydraulic conduit for supply to the hydraulic device is telescopically extendable.

5. The extendable boom according to claim 1 , wherein the hydraulic percussive drilling machine comprises a percussive unit and wherein the at least one hydraulic conduit is arranged to supply the percussive unit with the hydraulic fluid.

6. The extendable boom according to claim 1 , wherein four different hydraulic conduits are arranged alongside inside the extendable boom, a first conduit to a percussive unit of the drilling machine, a second conduit to a rotation motor of the drilling machine, a third conduit to a feed device for feeding the drilling machine back and forth, and a fourth conduit for a return flow to tank.

7. The extendable boom according to claim 1 , further comprising a hydraulic cylinder, in which at least one hydraulic conduit is arranged for feeding pressurised hydraulic fluid to a hydraulic device, wherein the hydraulic cylinder is arranged in connection to the extendable boom to govern extension of the extendable boom; a command unit arranged to command the extension of the hydraulic cylinder; a sensor arranged to monitor the extension of the hydraulic cylinder; and a control unit arranged to compare said monitored extension with the commanded extension.

8. The extendable boom according to claim 7 , wherein the hydraulic device is a hydraulic percussive drilling machine comprising a percussive unit and wherein the hydraulic conduit is arranged to supply the percussive unit with hydraulic fluid.

9. The extendable boom according to claim 7 , wherein an alert signal is issued when the control unit detects a discrepancy between the monitored extension and the commanded extension of the hydraulic cylinder.

10. The extendable boom according to claim 7 , wherein a feed system is arranged to compensate a fluid volume in the at least one hydraulic conduit for supply of hydraulic fluid to the hydraulic device, and wherein the control unit is arranged to control a supply of hydraulic fluid to the at least one hydraulic conduit corresponding to the increased volume of said at least one hydraulic conduit, and, when the at least one hydraulic conduit is compacted, the control unit is arranged to control a discharge of hydraulic fluid from the at least one hydraulic conduit corresponding to the decreased volume of said at least one hydraulic conduit due to that it is being compacted.

11. The extendable boom according to claim 7 , wherein the hydraulic device is a rock drilling machine that may operate at different hammering frequencies, and wherein the control unit is arranged to control the operation of the drilling machine so as to avoid hammering frequencies that have been identified to be prone to produce resonances in the at least one hydraulic conduit and/or to control the extension of the extendable boom so as to avoid a length of the at least one hydraulic conduit that may interfere with a desired hammering frequency.

12. A mining or construction vehicle comprising the extendable boom according to claim 1 .

13. The mining or construction vehicle according to claim 12 , wherein the mining or construction vehicle is a drill rig.

14. An extendable boom comprising at least a first telescopic section and a second telescopic section, wherein the first telescopic section and the second telescopic section extending in a longitudinal direction, wherein the first telescopic section is arranged to be connected to a mining or construction vehicle and a hydraulic device is arranged to be connected to a mounting device in connection to a free end of the second telescopic section, wherein the hydraulic device is a hydraulic percussive drilling machine, wherein at least one hydraulic conduit for supply of hydraulic fluid to the hydraulic device connected to the mounting device is arranged inside the extendable boom, wherein in order to allow the at least one hydraulic conduit to rotate with a rotation of a rotation device, a swivel arrangement is arranged, and wherein four different hydraulic conduits are arranged alongside inside the extendable boom, a first conduit to a percussive unit of the drilling machine, a second conduit to a rotation motor of the drilling machine, a third conduit to a feed device for feeding the drilling machine back and forth, and a fourth conduit for a return flow to a tank.

15. The extendable boom according to claim 14 , wherein the at least one hydraulic conduit is arranged through the free end of the second telescopic section of the extendable boom.

16. The extendable boom according to claim 15 , wherein the at least one hydraulic conduit extends substantially in parallel with the extendable boom in the longitudinal direction out from the free end of the second telescopic section of the extendable boom.

17. The extendable boom according to claim 14 , wherein the at least one hydraulic conduit for supply to the hydraulic device is telescopically extendable.

18. The extendable boom according to claim 14 , wherein the hydraulic percussive drilling machine comprises a percussive unit and wherein the at least one hydraulic conduit is arranged to supply the percussive unit with the hydraulic fluid.