Apparatus, rock breaking machine and method of monitoring rock breaking machine

Abstract

A hydraulic rock breaking machine and an apparatus and method for monitoring operation of the same is provided. The apparatus includes at least one pneumatic sensor arranged for monitoring an inner space of the machine and at least one control unit configured to receive and process the pneumatic sensing data.

Claims

1. A hydraulic rock drilling machine arranged to be mounted to a work machine, the rock drilling machine comprising: a body; a percussion device mounted inside the body, the percussion device being hydraulically operated, whereby a reciprocating percussion piston of the percussion device is moved by means of pressurized hydraulic fluid, and the percussion device being configured to generate impact pulses by means of the reciprocating piston to a drilling tool mountable to a front end of the body; at least one apparatus for sensing prevailing fluid pressure inside the rock drilling machine, wherein the apparatus includes at least one pressure sensing device arranged for sensing pressure of fluid inside the rock drilling machine, and at least one control unit configured to receive sensed pressure data from the at least one pressure sensing device, wherein the control unit is configured to process the received sensing data and to provide monitoring data in accordance with a control strategy input to the control unit; an oil mist lubrication system arranged for providing pressurized air-oil mist flow, the oil mist lubrication system being disposed inside the body; and at least one sensor of the at least one pressure sensing device being arranged for sensing pneumatic pressure of the air-oil mist prevailing inside the body and arranged to monitor pneumatic pressure fluctuation caused by the hydraulically movable piston of the hydraulic percussion device.

2. The rock drilling machine as claimed in claim 1, further comprising a shank adapter arranged for connecting the drilling tool, the shank adapter or the drilling tool being rotated by a rotating device via a gearing surrounding the shank adapter or the drilling tool, the oil mist lubricating system being configured to lubricate a front space surrounding a rear end portion of the shank adapter or the drilling tool and the gearing, wherein the at least one sensor is a pneumatic sensor in pneumatic connection with the front space and is arranged to sense pneumatic pressure of the air-oil mist prevailing inside the front space.

3. The rock drilling machine as claimed in claim 1, further comprising a rear space located at a rear end portion of the body, wherein the rear space is limited by a rear cover mounted releasably to the body, the rear space being in pneumatic communication with a rear end of the reciprocating piston of the percussion device, and wherein the at least one sensor is a pneumatic sensor in pneumatic connection with the rear space and is arranged to sense pneumatic pressure prevailing inside the rear space.

4. The rock drilling machine as claimed in claim 1, further comprising a feed port arranged for feeding the pressurized air-oil mist, and lubricating ducts for conveying the air-oil mist to at least one lubricating target inside the body, the at least one sensor being a pneumatic sensor arranged to sense pneumatic pressure prevailing inside the feed port or the lubricating ducts.

5. The rock drilling machine as claimed in claim 1, wherein the at least one sensor is mounted in direct connection with a monitored inner space of the rock drilling machine, wherein the at least one sensor is mounted close to the monitored inner space.

6. The rock drilling machine as claimed in claim 1, further comprising a dedicated monitoring space which is pressurized with gas and inside which a rear end of the piston of the percussion device is configured to move, and wherein the at least one sensor is in pneumatic connection with the dedicated monitoring space and is configured to detect fluctuating pneumatic pressure caused by the reciprocating rear end of the piston.

7. The rock drilling machine as claimed in claim 1, wherein lubrication oil and pressurized air of the oil mist lubrication system are fed inside the body, and wherein the pressurized air is configured to serve as a carrier medium for the lubrication oil, the at least one sensor being arranged to sense pneumatic pressure of the carrier medium prevailing inside the body.

8. A method for monitoring operation of a hydraulic rock drilling machine, the method comprising: providing the rock drilling machine with at least one sensing device for providing pressure data for the monitoring; providing pressurized air-oil mist flow inside a body of the rock drilling machine to lubricate the rock drilling machine; sensing pneumatic pressure of the prevailing air-oil mist inside the body of the rock drilling machine by means of the at least one sensing device; transmitting the sensed pneumatic pressure data to at least one control unit; and processing the sensed pneumatic pressure data in the control unit and generating monitoring data.

9. The method as claimed in claim 8, further comprising determining operational condition of the rock drilling machine by examining the monitoring data.

10. The method as claimed in claim 8, further comprising utilizing the monitoring data for providing predictive maintenance for the rock drilling machine.

11. The method as claimed in claim 8, further comprising controlling operating parameters of the rock drilling machine on the basis of the monitoring data, whereby the monitoring data is utilized for detecting different rock breaking situations and for controlling them.

12. The method as claimed in claim 8, further comprising determining speed of a piston of a percussion device of the rock drilling machine in an impact direction and a return direction in response to the detected pneumatic pressure variations.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic side view of a rock drilling rig, wherein a hydraulic rock drilling machine is provided with a pneumatic monitoring system.

(2) FIG. 2 is a schematic view of a work machine wherein a hydraulic rock breaking hammer is provided with a pneumatic monitoring system.

(3) FIG. 3 is a schematic view of a hydraulic rock drilling machine and pneumatic sensors arranged at possible measuring points.

(4) FIG. 4 is a diagram showing some pressure curves in function of time.

(5) FIG. 5 is a diagram showing some basic features relating to a pneumatic monitoring system.

(6) FIG. 6 is a diagram showing possible use cases for the generated monitoring data.

(7) FIG. 7 is a schematic view of a hydraulic rock drilling machine provided with a circulation lubrication system and including several pneumatic sensors arranged at possible measuring points.

(8) FIG. 8 is a schematic view of a rear space of the breaking machine including an inner space with a pneumatic space and pneumatic sensing arrangement.

(9) 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

(10) FIG. 1 shows a rock drilling rig 1 intended for drilling drill holes 2 in a rock surface 3. In this case the rock drilling rig 1 is intended for surface drilling, but the same principles disclosed apply also for underground drilling machines. The rock drilling rig 1 includes a movable carrier 4 and one or more drilling booms 5 connected to the carrier 4. At a distal end portion of the drilling boom 5 is a rock drilling unit 6 provided with a feed beam 7 and a rock drilling machine 8 supported thereon.

(11) A drilling tool 9 is connectable to the rock drilling machine 8. The rock drilling machine 8 is a hydraulic rock breaking machine 10, which is connected to a hydraulic system powered by a hydraulic unit 11. The rock drilling machine 8 includes a percussion device for generating impact pulses to the tool 9 in impact direction A. The rock drilling machine 8 also includes a rotating device R for turning the tool 9 around its longitudinal axis. The rock drilling machine 8 is further provided with one or more pneumatic sensors S, whereby the rock drilling machine 8 is instrumented. In other words, the hydraulically operated machine is examined by means of pneumatic sensing means.

(12) The rock drilling rig 1 may have one or more control units CU, which receive measuring signals from the sensors S and process the input sensing data. The control unit CU may be a dedicated device intended for the pneumatic monitoring system, or alternatively, a basic control unit of the rig 1 may serve also a processor for the pneumatic monitoring system. Alternatively, or in addition to, the system may have one or more external control units CU. Data communication between the sensors S and the on-board control unit CU may be wired or wireless. Further, the system may include at least one user interface UI or display unit through which the system may provide an operator with the monitoring data and by means of which the operator may input data, parameters, computer programs and make selections.

(13) FIG. 2 discloses an excavator 12, which is provided with boom 5 and hydraulic breaking hammer 13 at a distal end of the boom. The breaking hammer 13 is a hydraulic breaking machine 10 connected to a hydraulic system of the excavator 12 and is powered by means of a hydraulic unit 11. The breaking hammer 13 includes a percussion device 14, which is intended to provide a tool 9 with impact pulses for breaking rock material 15. The breaking hammer 13 is provided with one or more pneumatic sensors S, which monitor operation of the machine 10. Sensing data is transmitted to an on-board control unit CU or to an external control unit. The sensors S may detect pressure fluctuation inside the breaking hammer, which fluctuation is caused by a reciprocating percussion piston of the percussion device 14.

(14) FIG. 3 is a highly simplified presentation of a hydraulic rock drilling machine 8. The drilling machine 8 includes a main body 16 inside which is a percussion device 14 including a percussion piston 17. The piston 17 moves in a reciprocating manner towards impact direct A and return direction B. A front end of the piston 17 strikes rear end of tool 9. The tool 9 transmits impact pulses to a rock surface processed.

(15) The piston 17 is controlled by means of control valve 18, which may be located around the piston 17. The tool 9 is rotated around its longitudinal axis by means of a rotating device 19, which may be arranged to transmit the generated rotation via a gear 20 and rotation bushing 21 to a chuck 22 which receives the tool 9 or shank adapter. A front cover 23 may form a gear housing 24 surrounding the rotation means. At an opposite rear end of body 16 is a rear cover 25, which includes an inner rear space 26, which is in communication with a rear end 17a of the piston 17.

(16) The machine 10 may be provided with an air-oil lubrication system, whereby air-oil mist is fed through a feed port 27 inside the rear cover 25. The gaseous lubrication medium is conveyed through lubrication channel 28 to the front part of the machine 10 in order to lubricate the rotation gearing, the shank adapter and their bearings. Thus, inside the gearing housing 24 is an inner space wherein pressurized gaseous lubrication medium prevails.

(17) As it is shown, there may be one or more pneumatic sensors S mounted at the front part of the machine 10 for detecting gas pressures therein. Further, the air-oil lubrication system may be in fluid connection with the inner rear space 26. There may be a narrow venting channel 29 for allowing the lubrication system to be vented to the inner rear space 26 whereby gas pressure prevails also therein.

(18) The rear cover 25 is provided with a pneumatic sensor S for sensing pressure in the space 26. When the rear end portion 17a of the piston 17 moves forwards and backwards, it causes pressure fluctuation inside the space 26 and this can be sensed by means of the sensor S. The movement of the piston 17 causes pneumatic pressure variations also in the front part of the machine 10 and they can also be detected by means of the sensors located at the front end portion.

(19) An alternative to the solution shown in FIG. 3 is that there is no venting channel 29 to the lubrication system, but instead there is a gas feed port for providing the inner space 26 with any other gaseous medium. Also the pressure variations can be measured by means of one or more pneumatic sensors S.

(20) FIG. 4 shows two pressure curves of pneumatic sensors mounted to a rear portion of a percussion device (a curve with greater amplitude) and mounted to a front portion (smaller amplitude). Movement of a piston of the percussion device may be analyzed based on the pressure data and the curves. When the piston moves in the impact direction, then pressure decreases at the rear portion and correspondingly when the piston moves in the return direction, pressure increases. More detailed analyzing programs allow use of the pressure data in a versatile manner. It has been noticed, that interesting curves are gathered from the sensors inside a rear cover of the machine and in volume spaces where the piston is striking. Thus, in practical solutions, the rear cover appears to be the best place to measure. Moreover, the rear cover area is usually well accessible and, in many cases, a threaded hole that could be used for a sensor already exists therein or can be easily made.

(21) FIG. 5 shows a simplified diagram showing basic components of the disclosed pneumatic monitoring system and basic process steps executed in the monitoring. The presented issues have already been disclosed above in this document.

(22) FIG. 6 discloses some possible applications for the monitoring data produced by the disclosed pneumatic monitoring system. The figure is self-explanatory, and further, the presented issues have already been disclosed above in this document.

(23) FIG. 7 discloses a rock drilling machine provided with an oil circulation system wherein pressurized air is fed through a channel 30 and lubrication oil is fed through a channel 31. The pressurized air makes the oil to circulate inside the body. Otherwise, the solution of FIG. 7 may correspond to that shown in FIG. 3.

(24) FIG. 8 discloses end cover 25 of a breaking machine. Inner space 26 is provided with breathing channel 32, which may be provided with a throttle device, which may have fixed adjustment or it may be adjustable. In this case, the inner space is not connected to the lubrication system as it is in solutions disclosed in FIGS. 3 and 7. Sensor S may detect pressure fluctuations inside the space 26 caused by the reciprocating movement of the hydraulically moved piston 17.

(25) 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.