SE1450819A1

SE1450819A1 - Method and arrangement for post-drilling insertion

Info

Publication number: SE1450819A1
Application number: SE1450819A
Authority: SE
Inventors: Federico Scolari
Original assignee: Sandvik Mining & Constr Oy
Priority date: 2011-12-28
Filing date: 2011-12-28
Publication date: 2014-07-02
Also published as: WO2013098459A1

Abstract

The invention relates to a method and arrangement for post drilling insertion. A mining vehicle (1, 16) includes at least one boom (5b) provided with an insertion unit (17) for feeding an insertion object (26) into a pre-drilled hole (7). In order to facilitate the feeding rear end of the inserting object (26) is transversally moved during the feed. The insertion unit comprises a feed beam (23) along which a feed device (24) is moved in the feeding direction. Rear end (23b) of the feed beam can be moved along a curved path.(Figure 6a)

Description

Method and arrangement for post-drilling insertion Background of the invention The invention relates to method for post drilling insertion, whereinan elongated insertion object is fed into a pre-drilled hole. The feeding is per-formed by means of an insertion unit, which is arranged to a free end a boomthat belongs to a mining vehicle. The insertion object is pushed to the pre-drilled hole at least partly.

The invention still further relates to an insertion unit and to a miningvehicle.

The field of the invention is defined more specifically in the pream-bles of the independent claims.

Rock may be drilled in rounds. Then, drill holes are first drilled inrock, after which the drill holes are charged and blasted. Rock material be-comes detached from the rock by the amount of the length of the round, and itis transported elsewhere before drilling the next round. Various tunnels, under-ground storage halls, containers, parking spaces or other corresponding rockcaverns may be formed in the rock by excavation. However, the rock in whichsuch rock caverns are excavated is not always sufficiently firm, uniform andstable by nature. Also, blasting a round may break or otherwise weaken therock defining the rock cavern, so that the firmness of the rock is insufficientafter excavation. Thus, it is rather typical that the ceiling and walls of the rockcavern, sometimes even the floor, must be reinforced. Reinforcing may bedone by drilling to the rock several reinforcement holes in which a rock bolt, acable or the like reinforcement member or reinforcement material is fitted. Thereinforcement holes may be drilled by using a mining vehicle provided with adrilling boom having a drilling unit and means for mounting the reinforcement inthe drilled hole. The drilling unit and reinforcement insertion means are ar-ranged to the drilling boom so that at first a drill hole is drilled and there afterthe drilling unit is indexed away and the insertion means are placed in the frontof the drill hole mouth. The drilling boom is kept stationary and the units at thefree end of it are moved. A disadvantage in such arrangement is one unitstands still while the other unit is operating, whereby the working principle isineffective. Also this arrangement causes extra weight and stresses to theboom construction.

Brief description of the invention An object of the invention is to provide a novel and improved meth-od, an insertion unit and a mining vehicle for inserting objects into pre-drilleddri|| holes.

The method according to the invention is characterized by changingfeeding angle of the insertion object during the insertion relative to the directionof the pre-drilled hole.

The insertion unit according to the invention is characterized in thatthe insertion unit comprises at least one angle adjusting device for changingthe feeding angle of the insertion object.

The mining vehicle according to the invention is characterized inthat the insertion unit comprises at least one angle adjusting device, whereby afeeding angle of the insertion object can be changed during the feed.

An idea is that the drilling unit and the insertion unit are in differentbooms. Furthermore, the insertion unit is provided with one or more angle ad-justing device which is arranged to change or alternate feeding angle of theinsertion object relative to the direction of the pre-drilled hole.

An advantage of this is that when the operating units are in boomsof their own the operation is effective. Further, the disclosed angle adjustingfeature finds the hole direction automatically, whereby there is no need to posi-tion the inserting unit exactly to the same direction as a center line of the pre-drilled hole. This makes the positioning of the insertion unit faster. Further, lessdemand is set to directional information of the pre-drilled hole and insertionunit. l\/loreover, the insertion object penetrates more easily to the pre-drilledhole due to the feeding angle adjustment, whereby feed force can be de-creased. The construction is subjected to minor stresses, which improves theoperational life of the insertion unit. Also, thanks to the presented solutionfeeding of the insertion object can be ensured even in demanding circum-stances and situations. Thereby preplanned post-drilling measures can be per-formed effectively. All in all, a solution is presented to miss-alignment and holeirregularity problems occurring in the insertion procedure.

According to an embodiment the insertion unit is provided with anangle adjusting device which is arranged to move the rear end of the feedbeam in transverse direction relative to the feed line. During the adjustment thefront end of the feed beam can be kept stationary in transverse direction.

According to an embodiment a front end of the insertion object iskept stationary in a transverse direction during the change in the feeding an-gle. Thereby the change in the feeding angle is performed relative to the frontend.

According to an embodiment the adjustment of feeding angle of theinsertion object is set to be proportional to the feeding distance. At the begin-ning the feeding angle is changed with a greater magnitude and when feedingproceeds, the angle adjustment decreases. At the end of the feeding cycle thefeeding angle adjustment may be terminated. The decrease in angular adjust-ment can be continuous or it can be accomplished step wise.

According to an embodiment the angle adjusting device is arrangedto rotate or turn the rear end of the feed beam along a curved path of move-ment.

According to an embodiment the feeding angle is changed by apply-ing a spiral movement, whereby the rear part of the insertion object proceedsduring the insertion along a helical path of movement as it is simultaneouslymoved in its longitudinal feed direction.

According to an embodiment the insertion unit is provided with oneor more sensing means for detecting load that resists pushing of the insertionobject into the pre-drilled hole. The insertion unit may comprise one or moreforce sensor, for example a strain gauge, or alternatively force generated bythe feeding device can be measured. ln case feeding angle of the insertionobject is incorrect, the rock is fractured or otherwise unstable, or if the pre-drilled hole includes a partly collapsed narrow section, there occurs increasedforce resisting the feeding of the insertion object. ln the control unit there maybe a preset force level above which level insertion aid measures are started atthe latest.

According to an embodiment the feeding of the insertion object isstopped when the force resisting the feeding exceeds the preset force level.This avoids jamming of the insertion object and breakage of the feedingequipment and the insertion object.

According to an embodiment the feeding of the inserted object isstopped and the feeding direction is changed from the normal feed direction tothe reverse direction when the force resisting the feeding exceeds the presetforce level. The insertion object can be pulled backwards for a relatively shortdistance and after that the feeding to the normal feed direction is started again. lf necessary this push and pull sequence is repeated. The feeding aid cycleincluding the change in the feeding direction can be combined with the feedingaid cycle including the change in the feeding angle. At the end of the feeding ofthe insertion object when no angle adjustment is no longer possible problemsoccurring in the feeding can be solved by means of push and pull aid cycle.

According to an embodiment the insertion unit is controlled by oneor more control unit. The control unit may be provided with two, three, four oreven more installation modes having different control strategy for installing anobject into a pre-drilled hole.

According to an embodiment the operation cycle of the insertion unitis controlled automatically by means of the control unit. When the drill hole po-sition is detected by the positioning system the control unit may start the auto-matically insertion cycle including the steps and measures disclosed in thisapplication.

According to an embodiment the operation cycle of the insertion unitis controlled manually by an operator of the mining vehicle or alternatively inco-operation with the control unit.

According to an embodiment the inserting unit is provided with oneor more installation aid means in addition to the angle adjusting device.

According to an embodiment vibrating forces are directed to the in-stalled object in order to facilitate the installation. The installation unit may beprovided with one or more vibrating device. The vibrating device may comprisea hydraulic motor which is arranged to rotate an eccentric piece, for example.The vibration may occur simultaneously with one or more other installation aidmeans disclosed in this application.

According to an embodiment the installed object is rotated aroundits longitudinal axis in order to facilitate the installation. The installation unitmay be provided with a rotation device. The rotation device may correspond toa hydraulic rotation motor of a drilling machine, for example. The rotation mayoccur simultaneously with one or more other installation aid means disclosedin this application.

According to an embodiment impact pulses are directed to the in-stalled object during insertion. Thus longitudinally propagating stress wavesare formed so that the installation is facilitated. The installation unit may beprovided with an impact device. The impact device may be hydraulically oper- ated, for example. Percussion may occur simultaneously with one or more oth-er installation aid means disclosed in this application.

According to an embodiment the pre-drilled hole is a reinforcinghole. ln this case the insertion object may be an elongated physical piece suchas a rock bolt, tube or cable that is pushed into the drill hole. Alternatively theinsertion object may be a feed hose, tube or channel that can be partly pushedinto the drill hole where after reinforcing injection material such as a concreteor any other soldering material can be fed through the hose inside the drillhole. Thereby the insertion object may be a reinforcing piece or feeding meansfor charging material.

According to an embodiment the pre-drilled hole is a blasting hole.ln a post-drilling phase an explosive is fed to the drill hole. The explosive canbe in a form of a powder or granules whereby it can be fed into the drill hole bymeans of an elongated feed hose, tube or channel pushed at least partly in-side the drill hole. Further, it is possible to use explosive cartridges or packag-es, which can be rammed to the drill hole by means of an elongated bar.l\/loreover, in a small-charge-blasting mining method propellant charges are fedinto the drill hole through an elongated hose or tube. Thereby the insertion ob-ject may be an elongated explosive package or feeding means for blasting orpropellant material.

According to an embodiment in the post drilling phase an elongatedmeasuring probe is fed into the drill hole. Thereby the insertion object may bea sensing or measuring instrument. By means of such instrument drilling accu-racy compared to a drilling plan can be confirmed. For example direction of thedrill hole and bottom coordinates of the drill hole can be determined.

According to an embodiment the mining vehicle is a post-drilling ve-hicle without any drilling unit. Such a mining vehicle is a special-purpose vehi-cle equipped only for feeding insertion objects into the pre-drilled holes. Con-struction and control of such special mining vehicle can be optimized accordingto one purpose only.

According to an embodiment the mining vehicle is a multi-use vehi-cle being capable of drilling and insertion operations. Such a mining vehicle isprovided with at least two booms wherein at least one first boom is a drillingboom provided with a drilling unit and at least one second boom is a post-drilling boom provided with an insertion unit.

According to an embodiment the positioning of an insertion unit at apre-drilled hole includes two phases, namely a rough positioning and a finepositioning. The rough positioning is based on information gathered during thedrilling of the hole in question. For example coordinates and directional anglesof the holes are stored during drilling. By means of the rough positioning theinsertion boom and the insertion unit therein can be positioned close to thepre-drilled hole. ln the fine positioning the insertion unit is positioned to the pre-drilled hole so that it is possible to feed a front end of the insertion object to ahole collar. The insertion device may be provided with one or more camerasand a hole recognition system to identify the pre-drilled hole in a rock surface.The hole recognition system detects accurate position of the pre-drilled holeand control commands are given to boom actuators to implement the fine posi-tioning. Also, the insertion unit may be equipped with another type of detectorto detect or measure the accurate position of the hole mouth. An advantage ofthis embodiment is that positioning is faster since in the rough positioning theinsertion unit can be moved with rapid movements at a proximity of the pre-drilled hole after which only a short distance needs to be moved accurately inthe fine positioning step. The stored positioning information allows the fastrough positioning. This embodiment also makes it possible to use unmannedmining vehicles for post-drilling insertion.

According to an embodiment one or more identifier is arranged inconnection with at least one drilled bore hole in order to facilitate positioning ofdevices used in the post-drilling phases. The insertion unit may be providedwith means for reading or identifying the identifier placed into the drill hole ornear the mouth of the borehole. The drilling unit may be provided with a mount-ing or applying device for arranging the identifier at the drill hole before startingthe drilling operation, during the drilling operation or directly after the drilling.The identifier is installed before the drilling unit is moved away from the drilledhole towards the next drill hole position. The use of the identifier fastens andsimplifies the positioning of the post drilling units and devices and makes thepositioning accurate too.

According to an embodiment one or more drilled hole is providedwith one or more physical identifier piece. The identifier may be a tubularpiece, which can be partly inserted in a borehole, for example. The identifierimproves detection of the drilled hole. The identifier may have a colour or ashape that is easier to detect by means of a camera. The identifier piece may form a sharp edge for the drill hole, which improves detection of the hole byoptical means. Furthermore the identifier may comprise a transmitter and thepost-drilling device may comprise a receiver whereby a wireless data connec-tion can be created between the identifier and the insertion device. The datatransmission can be used for positioning the post-drilling units accurately to thepredrilled hole. The identifier may comprise a RFID (Radio Frequency lDentifi-cation) tag, for example.

According to an embodiment one or more pre-drilled hole is provid-ed with one or more colour medium. Around the drilled hole a colour markingcan be painted. The marking may have an annular shape. The drilling unit maybe provided with a spraying device or nozzle for applying the colour medium tothe drill hole collar. The colour medium can be selected so that the pre-drilledhole can be detected more easily with an optical hole recognition system com-prising one or more cameras and a computer vision system. Thanks to thepainted marking influence of shadows and surface irregularities can be dimin-ished. One possibility is to use reflecting paint or electromagnetic waves emit-ting paint and to provide the insertion unit with a light source or another suita-ble emitter. The computer vision system executes an image processing for dig-ital images taken by a digital camera arranged in the post-drilling unit. The im-age processing can be based on feature detection and feature extraction. As aresult of the image processing accurate position of the pre-drilled hole can beautomatically detected and control commands can be formed in a control unitof the mining vehicle for controlling boom actuators. The identifier according tothis embodiment can radically improve efficiency of the optical hole recogni-tion. Painted identifier is also easy to apply, inexpensive and endures well indemanding conditions.

According to an embodiment colour medium is fed through a drillingtool in order to make a position identifier to the rock surface. The colour medi-um can be fed via normal flushing channels to a drill bit wherefrom the colourmedium spreads to surrounding surfaces. An advantage of this embodiment isthat no separate paint system needs to be arranged in the drilling unit.

According to an embodiment colour medium is fed through a drill bitafter being extracted from the drill hole. Thereby a painted ring is formedaround the drill hole opening. This improves optical detection of the edge ofthe drill hole opening. lf desired, the paint inside the hole can be removed byreinserting the drill bit inside the drill hole and feeding flushing water through the drill bit to the drill hole whereby the paint is flushed away from the insidesurfaces of the drill hole. When the paint is removed inside the hole the edgedetection of the drill hole opening is improved since the drill hole shows as adark circle, which is surrounded by the colour marking. The colour medium canbe chosen so that a clear contrast occurs between the dark circle and the an-nular paint marking.

According to an embodiment two or more different colours areused for marking the drilled holes. The above disclosed physical identifierpiece or painted marking may have a colour code system wherein differentcolours may indicate rock features such as rock stability, fractured rock orvoids in rock. Hazardous drill holes can also be provided with a specific colourcode. lnformation for the colour code system can be gathered during the drill-ing manually by the operator of the rock drilling rig and automatically by meansof sensors and a drilling monitoring system.

Brief description of the figures Some embodiments are described in closer detail in the accompa-nying drawings, in which Figure 1 shows schematically a rock drilling rig positioned in theface of a rock cavern for drilling reinforcement or blasting holes, Figure 2 shows schematically a perspective view of a tunnel havingblasting holes and a reinforcement fan, Figure 3 shows schematically and seen from above an embodimentwherein a separate drilling vehicle and post-drilling vehicle are used, Figure 4 shows schematically and seen from above an embodimentwherein a mining vehicle includes a drilling boom and a post-drilling boom, Figure 5 shows schematically an insertion unit, Figures 6a - 6c show schematically an insertion cycle comprisingfeed and feed angle adjustment and possible other feeding aid measures, Figures 7 - 10 show schematically some alternatives for moving arear end of an insertion object along a curved path of movement, Figure 11 schematically shows a rock surface area wherein drillholes are drilled and some of the openings of the drill holes are provided withan identification aid, Figure 12 is a simplified diagram showing some features disclosedin this application.

For the sake of clarity, the figures show some embodiments of theinvention in a Simplified manner. ln the figures, like reference numerals identifylike elements.

Detailed description of some embodiments Figure 1 shows a rock drilling rig 1 navigated in a face 3 of a tunnel2 or the like rock cavern. The rock drilling rig 1 comprises a movable carrier 4provided with one or more drilling booms 5, each of which has a rock drillingunit 6 at its outermost end. The drilling unit 6 may be positioned at a start loca-tion of a drill hole 7 by moving the boom 5. Drill holes 7 can be drilled for around 8 and for a reinforcement fan 9. When the rock drilling rig 1 is driven tothe drilling location, navigation is first carried out in which the coordinate sys-tem of the drilling rig is connected to the coordinate system of the working site.The actual drilling cycle is performed for each drill hole after the drilling unit 6has first been positioned in the start location and direction determined by thedrilling pattern or controlled by an operator manually. The control system maycomprise one or more control units 12, which may be a computer or a proces-sor capable of determining the actual position of the boom. The boom 5 maycomprise two or more boom parts connected to each other by means of joints.ln the boom 5, there may be sensors 11 or the like measuring devices, and onthe basis of the position information obtained from them, the control unit 12can determine the location and direction of the drilling unit 6. The positioningdata of each hole 7 being drilled is stored and can be utilized in post-drillingactions such as in reinforcement or explosive insertion. Information can begathered also during the drilling utilizing a so called measuring while drillingsystem. This hole specific information can be utilized in post-drilling measurestoo. The drill hole data can be transmitted to a control unit 13 of a mine or di-rectly to a control unit of a second mining vehicle comprising post-drilling inser-tion means. ln Figure 1, the drilling unit 6 is positioned at the point of an excava-tion drill hole 7a to be drilled. The tunnel 2 is excavated by drilling in the face 3several excavation holes 7a substantially in the direction of a tunnel line L,which are charged with explosives after the drilling. At least positioning infor-mation of such blast holes 7a are saved for post-drilling charging. ln blasting,rock material is detached from the rock by the volume of the round 9. Blastinga round may damage the rock defining the tunnel contour, or the firmness ofthe rock may be insufficient by nature in order to guarantee a safe tunnel.

Thus, there may be a need to reinforce the ceiling 14 and walls 15 of the tun-nel 2. The rock may be reinforced by drilling, several adjacent reinforcementholes 7b to which a rock bolt or the like reinforcement members can be fitted.The number, depth, diameter, start locations and directions of reinforcementholes 7b among other drilling information may be stored in a memory mediaand can be used in post-drilling reinforcement insertion. The reinforcementholes 7b may be drilled in a fan form, whereby there are drill holes on bothwalls 15 and on the ceiling 14 of the tunnel. The direction of the reinforcementholes 7b is crosswise to the tunnel line L. ln Figure 2 it is illustrated a tunnel 2 having blast holes 7a for exca-vating a round 8 and a reinforcement fan 9 provided with several reinforcementholes 7b. ln a post-drilling phase insertion objects can be inserted into thesepre-drilled holes 7 by means of an insertion unit arranged in a post-drillingboom. Charges such as explosives or propellants can be inserted into the blastholes and reinforcing members such as rock bolts or injection material orgrouting material can be inserted into the pre-drilled holes.

Figure 3 shows an arrangement wherein drilling is performed by amining vehicle 1 having one or more drilling booms 5a provided with drillingunits 6, and for the post-drilling operation there is a special post-drilling miningvehicle 16 having one or more post drilling booms 5b provided with insertionunits 17. At first a rock drilling rig 1 is positioned to a drilling site and plannedholes 7 are drilled. Thereafter the post drilling mining vehicle 16 is positionedto the drilling site and insertion objects are fed into the pre-drilled holes 7. Co-ordinates, directional angle and other positioning information is stored duringthe drilling phase and the positioning information can be communicated fromthe control unit 12 of the rig 1 to a mine control unit 13 and to a control unit 18of the post-drilling mining vehicle 16. Thereby positioning information gatheredduring drilling can be utilized in positioning the insertion unit 17 at the pre-drilled hole.

The positioning of the mining vehicles 1, 16 to the working site canbe based on fixed position identifiers 19, scanned wall surface profiles 20 ofthe working site, distance measurement based on dead reckoning, peg num-bers 21 identifying mine distances, positioning based on wireless beacons,positioning in a wireless network, or their combination. Furthermore, in posi-tioning a tunnel laser 22 may also be utilized. After the positioning the miningvehicle is navigated so that one united coordinate system is used in drilling and 11 post-drilling actions. At least the position of each drilled hole is stored when thedrilling unit is positioned and drilling is started. Thereby coordinates of thedrilled holes are known by the positioning system. Positioning data can bestored and managed by using a standardized format, such as IREDES (Inter-national Rock Excavation Data Exchange System), whereby data is compatiblefor different control units involved. The positioning information is communicat-ed to the post-drilling mining vehicle 16, which is positioned and navigated tothe working site where the pre-drilled holes are located. The insertion unit 17 ispositioned according to the stored drill hole position information close to thepre-drilled hole 7. Since there may be inaccuracy in the positioning because ofclearances of the boom joints, it may be impossible or difficult to position theinsertion unit 17 directly to a collar of the pre-drilled hole. Therefore the posi-tioning may be completed with a fine positioning wherein the insertion unit 17is moved accurately to the collar of the pre-drilled hole. ln the fine positioning acomputer vision system can be utilized or different hole identifiers can be de-tected, for example. The fine positioning principles are discussed above in thisapplication and also in connection with Figure 5. ln Figure 4 an alternative arrangement is disclosed. The mining ve-hicle 1 is provided with one or more drilling booms 5a with drilling units 6 andone or more post-drilling or insertion booms 5b with insertion units 16. ln thisembodiment the mining vehicle 1 is a multi-use apparatus that can be posi-tioned and navigated to the working site in a manner disclosed in the descrip-tion of Figure 3. The drilling and insertion are carried out with different booms5a, 5b wherefore positioning data of the drilled holes are stored and utilizedwhen rough positioning the insertion unit 17 after drilling close to the pre-drilledhole 7 indicated as a black circle in Figure 4. Positioning information can bestored in the control unit 12 of the mining vehicle 1 and, if needed, it can becommunicated to one or more external control unit 13. ln Figure 5 one possible insertion unit 17 is shown. The insertionunit 17 comprises a feed beam 23 and a feed device 24 supported on the feedbeam. The feed beam 23 can be attached to a post-drilling boom 5b by meansof a cradle 25 or corresponding means. An insertion object 26 can be support-ed to a shank 27 of the feed device 24 and can be supported by a front sup-port 28 to a front end 23a of the feed beam. Thereby the insertion object 26 isin a feed line 29 and can be pushed forward and pulled rearward by the feeddevice 24, which is movable on the feed beam 23. The front end portion 23a of 12 the feed beam may comprise one or more cameras 30 in order to detect thepre-drilled holes after the insertion unit 17 is rough positioned 31 at a proximity32 to the pre-drilled hole on the basis of collected drilling position information.Thereafter the insertion unit 17 is fine positioned 33 from the proximity position32 accurately to a mouth of the pre-drilled hole 7. ln fine positioning 33 severalcameras can be used in order to produce stereo pictures or videos. The controlunit 12 comprises an image processing system for detecting optically the accu-rate position of the pre-drilled hole 7. Alternatively or in addition to cameras theinsertion unit 17 may comprise one or more identifiers, receivers or other de-tection means for hole recognition.

As can be seen in Figure 5, there may be an angle between thefeed line 29 and a center line 34 of the pre-drilled hole. ln case the insertionobject 26 has incorrect feed direction relative to hole direction there exist forc-es resisting the feeding. The inserting device 17 may comprise one or moresensors, measuring units or other sensing means 35 for detecting the feed re-sistance. When feed resistance is detected the control unit 12 can start variousfeed aid measures in order to facilitate the insertion. The insertion unit 17 maycomprise one or more angle adjusting device 36 by means of which a rear endportion 23b of the feed beam can be moved in transverse direction. The angleadjusting device 36 may rotate R the rear part 23b of the feed beam as it isshown in Figure 5. The rotation R is executed simultaneously with the feed Fwhereby a rear end of the insertion object 26 proceeds in a helical pattern. Thefront end of the feed beam may be supported against a rock surface or is keptstationary in some other way.

Figure 6a shows in a simplified manner start of the insertion cycle.At the beginning the rotation R has a greater magnitude i.e rotation is per-formed with a greater radius. That is because at first the purpose is to senseand find the direction 34 of the pre-drilled hole 7. As the insertion proceedsand the insertion object 26 penetrates into the hole 7 the angle adjustment isdecreased, as it is shown in Figures 6b and 6c. Further, in Figure 6c resistingforces are detected because there is an irregular portion 37 in the hole thatcauses problems for the insertion. lncreased feed resistance is detected andthe control unit may thereafter control the feeding with different feed aid controlmodes. According to one control mode feed direction is changed 38 betweennormal direction and reverse direction according to the feed resistance. ln an- 13 other control mode the insertion object 26 is rotated or turned around its longi-tudinal axis 39 during the feed.

Figures 7 to 9 illustrate in a highly simplified manner some possibleangle adjusting devices 36 for implementing a transverse movement for a feedbeam rear end 26b. ln Figure 7 the angle adjusting device 36 comprises apressure medium cylinder or a corresponding linear actuator 40 which can beturned a limited angle by means of turning actuator 41. When the actuators 40,41 are executed simultaneously the rear end of the feed beam can be rotatedR in a desired magnitude and rotation direction. Depending the controlling ofthe actuators 40, 41 other curved movement paths and also linear transversemovements can be generated. ln Figure 8 the angle adjusting device 36 com-prises two linear actuators 42, 43, such as cylinders, which can be simultane-ously controlled for generating rotation R and various paths of movements. lnFigures 7 and 8 the combined action of two or more actuators causes thecurved movement path. ln Figure 9 the angle adjusting device 36 comprises acurved guide surface 44 along which the rear end of the feed beam 23 can bemoved by a drive mechanism 45. ln this embodiment the shape of the guidesurface defines the movement path. ln Figure 10 there are shown two more alternatives for angular ad-justment devices. An alternative angle adjusting device 36a can be arrangedbetween the feed beam 23 and the feed device 24. The device 36a may in-clude actuators for moving the feed device 24 in the transverse direction. Fur-ther, an angular adjusting device 36b can be integrated to the feed device 24or to a shank or adapter attached to the feed device. The adjusting device 36bcomprises at least one linear actuator for moving the rear end of the insertionobject 26 in a transverse direction and at least one rotation device for rotatingthe rear end of the insertion object around axis l\/I after being first transversallymoved 29a by the linear actuator. The operation of the device 36b is thusbased on eccentric position of the rear end of the insertion object 26 and simul-taneous rotation. These angular adjustment devices 36a, 36b may be sufficientin some cases or they may be used in combination with the angular adjustmentdevices influencing the feed beam. Further, it is to be noted that other possibili-ties exists for rotating or moving the rear end portion of the insertion object dur-ing the insertion cycle. ln Figure 11 there is a rock surface area wherein drill holes aredrilled and some of the openings of the pre-drilled holes 7 are provided with an 14 identification aid. The pre-drilled holes 7 show as dark circles in optical detec-tion means. A physical identifier 46 may be arranged in a drilling cycle insidethe hole 7. The identifier 46 may a tubular piece having an outer edge 47 hav-ing a color or shape which improves optical detection. One possibility is topaint around the hole opening an annular identification marking 48 which im-proves the optical hole recognition. Furthermore, the hole may be providedwith a RFID tag or corresponding machine readable active or passive wirelessidentifier 49. ln Figure 12 some of the above discussed embodiments and fea-tures are shown in a simplified diagram. ln some cases, the features disclosed in the present applicationmay be used as such, irrespective of other features. On the other hand, whennecessary, the features disclosed in the present application may be combinedso as to provide different new combinations.

The drawings and the related description are only intended to illus-trate the idea of the invention. ln its details, the invention may vary within thescope of the claims.

Claims

1. A method for post-drilling insertion, the method comprising: positioning an insertion unit (17) at a pre-drilled hole (7); and inserting at least one elongated insertion object (26) into the pre-drilled hole (7) by directing a feed force from a feeding device (24) to the inser-tion object (26); characterized by changing feeding angle of the insertion object (26) during the inser-tion relative to the direction of the pre-drilled hole.

2. A method as claimed in claim 1, characterized by keeping a front end of the insertion object (26) stationary in a trans-verse direction during the change in the feeding angle and changing trans-verse position of a rear end of the insertion object (26), whereby the change inthe feeding angle is performed relative to the front end.

3. A method as claimed in claim1or2, characterized by arranging magnitude of the feeding angle change in relation to afeeding depth of the insertion object (26); and applying a greater feeding angle change at a beginning of the feed-ing of the insertion object (26) than at the end of the feeding.

4. A method as claimed in any of the preceding claims, c h a r a c -t e r i z e d b y changing the feeding angle by applying a spiral movement, wherebythe rear part of the insertion object (26) proceeds during the insertion along ahelical path of movement caused by the simultaneous spiral movement andlongitudinal linear movement.

5. A method as claimed in any of the preceding claims, c h a r a c -t e r i z e d b y sensing by means of sensing means (35) force resisting the feedingof the insertion object (26); and controlling the insertion by taking into account the detected feed re-sistance. 16

6. A method as claimed in claim 5, characterized by pulling the insertion object (26) in reverse direction as the feed re-sistance exceeds a predetermined limit; returning the feed direction to the original; and alternating pushing and pulling of the insertion object (26) accordingto the feeding resistance.

7. A method as claimed in any of the preceding claims, c h a r a c -te r i z e d b yvibrating the insertion object (26) during the insertion.

8. A method as claimed in any of the preceding claims, c h a r a c -te r i z e d b y rotating (39) the insertion object (26) around its Iongitudinal axis dur-ing the insertion.

9. An insertion unit for feeding an insertion object into a pre-drilledhole comprising: a feed beam (23), which is an elongated piece having a front end(23a) and a rear end (23b); a feed device (24), which is supported by the feed beam (23), andwhich is movable in a feeding direction towards the front end (23a) and in areverse direction; and at least one feed support (27) in the feed device (24) for attachingthe insertion object (26) on a feed line (29) for the feed; characterized in that the insertion unit (17) comprises at least one angle adjusting device(36) for changing a feeding angle of the insertion object during the feed.

10. An insertion unit according to claim 9, c h a racte rized inthat the angle adjusting device (36) moves the rear end (23b) of the feedbeam in transverse direction relative to the feed line (29) while keeping thefront end (23a) of the feed beam stationary in transverse direction. 17

11. An insertion unit according to claim 10, c h a r a c t e r i z e d inthat the angle adjusting device (36) is arranged to move the rear end(23b) of the feed beam along a curved path of movement.

12. An insertion unit according to any one of the preceding claims 9to 11, characterized in that the insertion unit (17) is controlled by at least one control unit (12); the insertion unit is provided with at least one sensing unit (35) fordetecting force resisting the feeding of the insertion object (26); and the control unit (12) alternates at least the forward feed and reversefeed according to the detected feed resistance.

13. An insertion unit according to any one of the preceding claims 9to 12, characterized in that the insertion unit (17) is provided with at least one detector (30) fordetecting accurate position of the pre-drilled hole (7).

14. A mining vehicle, comprising: a movable carrier (4); at least one boom (5) movable relative to the carrier (4); at least one boom (5b) is provided with an insertion unit (17) forfeeding at least one insertion object (26) into a pre-drilled hole (7), and whereinthe insertion unit (17) comprises a feed beam (23), a feed device (24) and atleast one feed support (27) in the feed device for attaching the insertion object(26): characterized in that the insertion unit (17) comprises at least one angle adjusting device(36), whereby a feeding angle of the insertion object can be changed duringthe feed.

15. A mining vehicle as claimed in claim 14, c h a r a c t e r i z e d inthat the angle adjusting device (36) is arranged to move a rear end (23b)of the feed beam in transverse direction while keeping a front end (23a) of thefeed beam transversally stationary. 18

16. A mining vehicle as claimed in claim 14 or 15, c h a racte r -i z e d in that the mining vehicle is a post-drilling vehicle (16) without any drillingunit.

17. A mining vehicle as claimed in claim 14 or 15, c h a racte r -i z e d in that the mining vehicle (1) is provided with at least two booms; and a first boom is a drilling boom (5a) provided with a drilling unit (6)and a second boom is a post-drilling boom (5b) provided with an insertion unit(17).