EP2475839A1

EP2475839A1 - Rock drilling unit, feed beam, and method for damping vibration

Info

Publication number: EP2475839A1
Application number: EP10815037A
Authority: EP
Inventors: Sampo Sivula; Pekka Saukko; Lassi Luoma; Ilmo PYÖRNY; Esko Sarin; Velipekka Mellin; Mikko PYYKKÖ; Timo Muuttonen
Original assignee: Sandvik Mining and Construction Oy
Current assignee: Sandvik Mining and Construction Oy
Priority date: 2009-09-08
Filing date: 2010-09-01
Publication date: 2012-07-18
Also published as: ZA201202471B; CN102575500B; EP2475839A4; CA2772587C; JP5330602B2; FI20095923A; FI20095923A0; WO2011029992A1; JP2013503990A; AU2010294119B2; CN102575500A; AU2010294119A1; CA2772587A1

Abstract

The invention relates to a rock drilling unit, feed beam,and method for damping vibration in a rock drilling unit.In the rock drilling unit (3),a damping element (13) is arranged between the joint surfaces of two inter-connected components to damp vibration and prevent its transmission on in the structure of the drilling unit. The feed beam (6) may be divided into two or more parts (6a, 6b) with a damping element of possibly elastic material arranged between them.

Description

Rock drilling unit, feed beam, and method for damping vibration

Background of the invention

[0001] The invention relates to a rock drilling unit that is connectable to a rock drilling rig. The rock drilling unit contains a rock drilling machine that is supported to an elongated feed beam and can be moved on the feed beam by means of a feed device. The feed beam is, in turn, connected to a drilling boom of the rock drilling rig by means of a fastening member.

[0002] The invention further relates to a feed beam and method for damping vibration in the rock drilling unit. The field of the invention is described in more detail in the preambles of the independent claims of the patent application.

[0003] Rock drilling rigs are used for drilling holes into rock being excavated both in mines and at earth-moving sites. A rock drilling rig is typically equipped with a drilling boom with a rock drilling unit having at least a rock drilling machine, feed beam, and feed device. The rock drilling machine provides impact pulses to a tool that breaks the rock and forms a borehole. The operation of a rock drilling machine causes quite strong vibration that is transmitted in the rock drilling unit from one component to another and also on to the drilling boom and rest of the structure of the rock drilling rig. Vibration causes sound projection off the surfaces of pieces, whereby an unpleasant noise spreads into the surrounding area. In addition to noise, the vibration propagating in the structures also causes movement between the components, which may cause premature wear and other problems related to the durability of the devices.

Brief description of the invention

[0004] It is an object of this invention to provide a novel and improved rock drilling unit, feed beam, and method for damping vibration.

[0005] The rock drilling unit of the invention is characterised in that the feed beam comprises at least two feed beam parts arranged on top of each other, the first feed beam part being on the side of the rock drilling machine and the second feed beam part being on the side of the fastening member; and that between the first and second feed beam parts, there is at least one damping element that separates the joint surfaces of the feed beam parts from each other. [0006] The feed beam of the invention is characterised in that the cross-section of the feed beam comprises at least one first feed beam part and at least one second feed beam part that are of equal length with the feed beam and that are fastened to each other one on top of the other; and that between the first and second feed beam parts, there is at least one damping element that is arranged to damp vibration in the feed beam or prevent the transmission of vibration between the feed beam parts.

[0007] The method of the invention is characterised by forming the feed beam of at least two parts, and arranging at least one damping element between their joint surfaces to prevent the transmission of vibration through the feed beam.

[0008] The idea of the invention is to damp the vibration caused by the rock drilling machine in the rock drilling unit and to prevent its transmission on between the components belonging to the rock drilling unit. Joint surfaces, which are usually of metal, between the components of a drilling unit can be separated from each other by means of a damping element. The feed beam comprises a first feed beam part and a second feed beam part having one or more damping elements arranged between their joint surfaces.

[0009] An advantage of the invention is that vibration can be damped close to the source of the vibration. Further, it is possible to prevent the propagation of vibration from the rock drilling unit to the drilling boom and elsewhere in the rock drilling rig in an efficient and simple manner. When vibration is damped, it is also possible to reduce the noise caused by the vibration. Requirements related to noise control will become stricter in the near future. The invention provides a relatively simple solution as part of noise control. Further, with the damping arrangements of the invention, it is possible to lengthen the service life of the rock drilling rig and to reduce the need for maintenance, when vibration that causes premature wear in the structures can be reduced.

[0010] The idea of an embodiment is that one or more damping elements are arranged on the section between the rock drilling machine and feed beam. It is then possible to prevent the transmission of vibration from the rock drilling machine to the feed beam. A feed beam often has quite large surfaces that may project noise as a result of vibration. With this embodiment, it is possible to prevent the transmission of structure-borne noise to the feed beam.

[0011] The idea of an embodiment is that the structure of the feed beam comprises one or more damping elements. This, then, reduces the transmission of vibration through the feed beam. Further, the damping element in the feed beam may absorb vibration and, thus, damp vibration in the feed beam.

[0012] The idea of an embodiment is that the feed beam comprises a first feed beam part and a second feed beam part having essentially the same length as the feed beam and having one or more damping elements arranged between their joint surfaces. The feed beam parts are fastened stationary to each other. The first feed beam part is equipped with first support surfaces, to which a carriage can be supported, and the second feed beam part is equipped with second support surfaces, to which a cradle can be supported. This embodiment prevents the transmission of vibration through the structure of the feed beam. In addition, the damping element may damp the vibration of the feed beam. Further, the wall surfaces of a two- or multi-part feed beam are smaller in size than those of a one-part feed beam, whereby the risk of noise caused by the vibration of the wall surfaces is smaller.

[0013] The idea of an embodiment is that the feed beam comprises a first feed beam part and a second feed beam part. The second feed beam part is formed of two components that are connected to each other in the lateral direction of the feed beam. There may be a form-lock fastening between the first and second feed beam parts.

[0014] The idea of an embodiment is that the feed beam is connected by a fastening member to the drilling boom or alternatively to some other structure of the rock drilling rig. At the fastening member, there may be one or more damping elements that reduce the transmission of vibration from the rock drilling unit onward. The fastening member may be a cradle that is supported to an elongated guide surface on the side of the feed beam, whereby the cradle and feed beam may be moved relative to each other. The cradle may be equipped with one or more damping elements. The cradle may also be formed of two or more parts, whereby the damping element may be arranged on the joint surfaces between there parts.

[0015] The idea of an embodiment is that the rock drilling machine is connected with a carriage to the feed beam. The carriage may comprise a first carriage part and a second carriage part arranged on top of each other and having one or more damping elements arranged between them. The first carriage part is arranged against the rock drilling machine and the second carriage part is arranged on the side of the feed beam. During drilling, feed forces are directed to the first carriage part on the drilling machine side, whereby the feed forces are transmitted rigidly to the drilling machine and not through the damping element.

[0016] The idea of an embodiment is that the rock drilling machine is supported to the feed beam by means of one or more replaceable slide blocks. Typically, several slide blocks are used. The rock drilling machine may be connected to the feed beam by means of a carriage and a slide block fastened to the carriage. Alternatively, the drilling machine may be carriage-less, whereby the slide blocks can be fastened to the body of the drilling machine to support it to the feed beam. The damping element may be integrated to the slide block. The slide block may comprise at least two differing materials, namely slide bearing material and elastic damping material. The slide bearing material is very wear-resistant and it is naturally intended to be arranged against a guiding surface on the feed beam.

[0017] The idea of an embodiment is that the rock drilling unit comprises a protective casing that surrounds the feed beam either entirely or at least partly. The rock drilling machine is also inside the protective casing, whereby the protective casing prevents any noise projecting from the drilling machine directly to the surrounding area. The protective casing may be formed of vibration-damping material, and it may be arranged between components belonging to the rock drilling unit so that it also prevents the transmission of vibration between the interconnected components. When vibration is damped in the drilling unit, the vibration directed to the protective casing and the noise caused thereby is also damped. This also simplifies the implementation of the structure and fastening of the protective casing.

[0018] The idea of an embodiment is that the feed beam comprises a first part on the rock drilling machine-side and a second part on the cradle side having a side wall of the protective casing arranged between them to act as a damping element between the joint surfaces. Alternatively, some other part of the protective casing, such as its fastening portion or the like may be arranged to act as the damping element.

[0019] The idea of an embodiment is that a coating arranged on a component belonging to the drilling unit acts as the damping element. The coating may reflect vibration back or it may absorb it. [0020] The idea of an embodiment is that the feed beam is at least partly coated with material suitable for vibration prevention. In some cases, the feed beam or feed beam part is coated entirely with this type of material.

[0021] The idea of an embodiment is that the damping element is made of one or more vibration-damping materials. The vibration-damping material may be rubber, polymer, or some other elastic material that poorly transmits vibration.

[0022] The idea of an embodiment is that the damping element may comprise a mechanical damping member, such as a spring member.

[0023] The idea of an embodiment is that the damping element comprises a pressure medium chamber, in which the pressure medium is arranged to damp vibration and prevent its transmission onward.

Brief description of figures

[0024] Some embodiments of the invention will be described in more detail in the attached drawings, in which

Figure 1 is a schematic side view of a rock drilling rig,

Figure 2 is a schematic side view of a rock drilling unit,

Figure 3 is a schematic cross-sectional view of a feed beam comprising two feed beam parts connected to each other with a damping element,

Figure 4 is a schematic cross-sectional view of a second feed beam and the support of a drilling machine by means of a carriage and slide blocks,

Figure 5 is a schematic cross-sectional view of a third feed beam, where the feed beam part on the cradle side is formed of two pieces interconnected in the lateral direction of the feed beam,

Figure 6 is a schematic cross-sectional view of a feed beam formed of two feed beam parts having a side wall of a protective casing between their joint surfaces,

Figure 7 is a schematic cross-sectional view of a feed beam that is arranged inside a protective casing that acts as a vibration-damping member between the fastening surfaces of the feed beam and cradle-side slide block,

Figure 8 is a schematic cross-sectional view of a feed beam that is fastened to a protective casing that connects the feed beam and cradle-side slide block to each other and also acts as a vibration-damping element,

Figure 9 is a schematic cross-sectional view of a drilling unit having a drill machine arranged on a carriage that is divided into two parts that are separated from each other with a damping element against vibration, Figure 10 is a schematic cross-sectional view of a drilling unit having a damping element between the drilling machine and carriage, and the drilling machine comprises a feed face for transmitting feed forces directly to the drilling machine,

Figure 1 1 is a schematic cross-sectional view of a drilling unit, in which means for connecting to a cradle are arranged in a protective casing,

Figure 12 is a schematic cross-sectional view of a drilling unit, in which the cross-section of the feed beam comprises two beam parts on top of each other and a protective casing is fastened to the cradle-side beam part,

Figures 13 to 15 are schematic cross-sectional views of feed beams that each comprise at least two feed beam parts that are arranged on top of each other and stationary relative to each other,

Figures 16 to 18 are schematic cross-sectional views of feed beams that each comprise a substantially U-shaped cross-section on their rock drilling machine-side portion, and

Figure 19 is a schematic and exploded view of a possible lead- through element, and Figure 20 shows said lead-through element installed in place in a protective casing.

[0025] In the figures, some embodiments of the invention are shown simplified for the sake of clarity. Similar parts are marked with the same reference numbers in the figures.

Detailed description of some embodiments of the invention

[0026] The rock drilling rig shown in Figure 1 comprises a movable carrier 1 having one or more drilling boom 2 equipped with a rock drilling unit 3 arranged thereto. The rock drilling unit 3 comprises a rock drilling machine 4 having a percussion device to provide impact pulses to a tool 5 connected to the drilling machine and transmitting the impact pulses to the rock being drilled. The rock drilling machine 4 is moved on the feed beam 6 by means of a feed device in direction A.

[0027] Figure 2 shows the structure of the rock drilling unit 3 in more detail. The feed beam 6 is an elongated piece, to which the rock drilling machine 4 may be connected by a carriage 7, or alternatively the body of the rock drilling machine 4 may be supported to the feed beam without a carriage by means of suitable sliding blocks, for instance. The feed device 8 may be connected to act on the carriage 7 or, when the structure is without a carriage, the feed device 8 is arranged to act directly on the drilling machine. The feed beam 6 may be supported to the drilling boom 2 by means of a cradle 9 so that the feed beam 6 may be moved in its longitudinal direction B relative to the end of the drilling boom 2. In some cases there may be some other fastening member instead of the cradle between the feed beam 6 and drilling boom 2, if the feed beam 2 need not be moved in direction B. Further, the drilling unit 3 may comprise a protective casing 10 or a corresponding protective structure that surrounds either the entire drilling unit 3 or at least part of it. The purpose of the protective casing 10 is to damp the noise projected from the rock drilling machine 4 to the surrounding area and to protect the people at the drilling site and possibly to protect the drilling unit from external blows.

[0028] The operation of the rock drilling machine 4 causes vibration that is transmitted to the structures of the drilling unit 3. The operation of a percussion device 1 1 in particular, but also that of a rotating device 12, may cause vibration that propagates from the rock drilling machine 4 to the carriage 7 and on to the feed beam 6 and finally through the cradle 9 to the drilling boom 2, from which it may propagate to other structures of the rock drilling rig. Vibration is transmitted from one component to another through joint surfaces between the components. With the damping embodiments presented in the patent application, it is possible to damp vibration in the components belonging to the drilling unit and separate joint surfaces from each other and, thus, prevent the transmission of harmful vibration between the components belonging to the drilling unit. The damping element may act as a separator between components, it may cause the vibration to partially reflect backward, or it may act as a transmission damper, whereby it may absorb vibration and transform vibration energy into heat. Depending on the case, the damping element may damp vibration by using one or more above-mentioned principles.

[0029] Figure 3 shows the cross-section of a vibration-damping feed beam 6. The feed beam 6 comprises a first feed beam part 6a on the rock drilling machine-side, a second feed beam part 6b on the cradle side, and one or more damping elements 13 arranged between the parts to separate the joint surfaces of the feed beam parts 6a, 6b from each other. The damping element 13 may be made of elastic material that damps vibration and prevents its transmission from the first feed beam part 6a to the second feed beam part 6b. In addition to separating, the damping element 13 may also absorb vibration. The first feed beam part 6a has first support surfaces 14, against which slide blocks or corresponding slide surfaces in the carriage or directly in the drilling machine may lean. Correspondingly, the second feed beam part 6b has second support surfaces 15, against which the cradle or a corresponding fastening member may lean. In some cases, it is possible that the feed beam 6 is formed of even more feed beam parts, for instance in such a manner that between the first feed beam part 6a and second feed beam part 6b shown in Figure 3, there is a third, middle feed beam part that is separated by damping elements 13 from the upper and lower feed beam parts. It is also possible to use several separate damping elements instead of one uniform damping element 13.

[0030] Figure 4 shows a feed beam 6 that also comprises two feed beam parts 6a and 6b separated from each other and one on top of the other. Differing from Figure 3, instead of a uniform damping element 13, several separate damping elements 13a, 13b are arranged between the feed beam parts 6a, 6b, and their damping ability may be based on their material, shape, or mechanical functionality. Figure 4 further shows that between the support surfaces 14 of the carriage 7 and first feed beam part 6a, there are slide blocks 16 that may be formed of at least two different materials. The slide block 16 may comprise on the support surface 14 side material 16a having good slide bearing properties and on the carriage 7 side material 16b having good vibration-isolating ability. Further, it may be possible to form the slide block 16 of material having good bearing and damping properties. The slide blocks 16 then also participate in vibration-isolation. Slide blocks 16 of this type may also be utilized in other embodiments described in this patent application.

[0031] Figure 4 also shows that the feed beam 6 and feed beam parts 6a, 6b, being hollow on the inside, may be entirely or partly filled with a filling agent 17. The filling agent 17 may be light, foam-like material, such as polyurethane, that damps the vibration of the feed beam walls and prevents noise generation. A long feed beam often has quite large but at the same time thin wall surfaces that easily begin to vibrate and generate noise. This embodiment may be used to complement the actual vibration-damping, if necessary.

[0032] Figure 5 shows a feed beam 6 that comprises a first feed beam part 6a and a second feed beam part 6b arranged on top of each other. The cradle-side second feed beam part 6b is divided into two elongated components 18a and 18b that may be symmetrical in cross-section. The components 18a and 18b are joined together in the lateral direction C of the feed beam. Further, the bottom surface of the cross-sectional profile of the first feed beam part 6a has a projecting section 19 that may be in the shape of a dovetail, for instance. The joined components 18a and 18b correspondingly form on their rock drilling machine-side top surface a correspondingly shaped space 20 that may receive said projecting section 19. The projecting section 19 and space 20 form a form lock between the feed beam parts 6a and 6b, whereby the fastening of the feed beam parts is firm and the feed beam is made rigid. Further, between the joint surfaces of the feed beam parts 6a and 6b, there is one or more damping elements 13 that prevent vibration transmission in the structure of the feed beam 6. The damping element 13 may also absorb vibration. The damping element 13 remains firmly in place between the shaped feed beam parts 6a and 6b. The cross-sectional form of the damping element may correspond to that of the joint surfaces. The damping element may be a shape- cast or extruded profile, for instance. A screw fastening, for example, may be used between the components 18a, 18b. Thanks to the form lock, the feed beam parts 6a, 6b may remain fastened to each other even without any separate fastening means. Differing from Figure 5, it is also possible that the second feed beam part 6b comprises a projecting part and the first feed beam part 6a comprises the space receiving the projecting part 19.

[0033] The damping element shown in Figures 3 and 5 may be a separate piece, or alternatively it may be a coating or corresponding material layer that is attached to one or both of the feed beam parts 6a, 6b.

[0034] In the solution shown in Figure 6, the first feed beam part 6a is arranged inside a protective casing 10. The side surface 10a of the protective casing 10 may be arranged between the joint surfaces of the first feed beam part 6a and the second feed beam part 6b, in which case the side surface 10a separates the joint surfaces from each other. The protective casing 10 may be formed of material that is capable of isolating vibration transmission, whereby its side surface 10a may act as a damping element between the joint surfaces. Naturally, it is possible to form just one side surface 10a of the protective casing of vibration-isolating material, whereby the remaining material and structure of the protective structure may be freely chosen. It is also possible to arrange a coating made of vibration-isolating material on the side surface 10a of the protective casing and use separate damping elements.

[0035] Figure 7 shows an embodiment, where the rock drilling machine 4 and feed beam 6 are arranged inside the protective casing 10. The feed beam 6 has a cradle-side joint surface 22, to which a slide guide 23 at- tachable to the cradle is fastened. The slide guide 23 comprises slide surfaces 15a that may be supported to the cradle. The side surface 10a of the protective casing is arranged between the joint surface 22 of the feed beam and the slide surface 24 of the slide guide, whereby it may act as a vibration-isolating element. The material of the protective casing 10 may be made of material that isolates and absorbs vibration. This solution does not cause changes to the cross-sectional profile and structure of the conventional rigid feed beam 6.

[0036] Figure 7 also shows that the rock drilling machine 4 may be carriage-less, in which case its body 25 is supported directly to the support surfaces 14 of the feed beam by means of slide blocks 16. An isolating layer may be integrated into the structure of the slide block 16. Further, there may a damping element between the body 25 and slide block.

[0037] Figure 7 further shows that the side surfaces of the feed beam 6 may be equipped with damping strips 35, with which it is possible to act on the vibration properties of the feed beam 6. The number, location, material, and shape of the damping strips 35 may be selected separately for each case.

[0038] In the solution shown in Figure 8, the feed beam 6 is fastened to a protective casing 10 that, in turn, is fastened to a slide guide 23 on the cradle side. The joint surface 22 of the feed beam 6 is not arranged at the joint surface 24 of the slide guide, but the fastening is provided through the wall 10a structure of the protective casing. The protective casing 10 may be made of elastic material, whereby the wall 10a may act as a vibration-isolating fastener between the feed beam 6 and slide guide 23.

[0039] Figure 9 shows a possible embodiment, in which the carriage 7 is divided into a first carriage part 7a on the drilling machine 4 side and a second carriage part 7b on the feed beam side. One or more damping elements 13 are arranged between the carriage parts 7a, 7b, whereby the joint surfaces between the carriage parts are separated from each other. The second carriage part 7b comprises slide blocks 16, with which it is supported to the feed beam. The rock drilling machine 4 may be rigidly fastened to the first carriage part 7a, whereby feed forces may be transmitted from the feed device to the first carriage part 7a. The first carriage part 7a may be equipped with a projecting part 26 that is arranged through an opening 27 in the second carriage part 7b so that it may extend to a groove 28 on the top surface side of the feed beam 6. The feed device may be arranged into said groove. A connecting point 29 to which the feed device may be arranged to direct feed forces is marked with a dashed line on the projecting part 26. When feed forces are directed to the first carriage part 7a, no harmful loads are directed to the damping element 13.

[0040] Figure 10 shows yet another embodiment, in which one or more damping elements 13 are arranged between the body 25 of the rock drilling machine 4 and carriage 7. In this case, the feed force may be directed directly to the body 25 of the rock drilling machine, whereby feed forces do not transmit through the damping elements 13. Thus, the feed forces do not strain the damping elements 13 and, on the other hand, the damping elements 13 do not cause flexes and inaccuracies caused by them in the feed movements. On the bottom surface side of the body 25, there may be a projection 30, and the feed forces may be directed to a connecting point 29 in it. The feed device may be arranged into a groove 28 on the top surface of the feed beam 6. Alternatively, the body 25 may have one or more connecting points 31 , on the top surface thereof, for example.

[0041] It should be mentioned that in the embodiments of Figures 9 and 10, the feed beam 6 may be one uniform structure as shown, or it may be divided into two or more parts separated from each other with a damping element, for instance as shown in Figures 3 to 8. Further, it is possible to combine different damping elements in these embodiments.

[0042] In general, it may further be noted that the joint surfaces of the rock drilling unit components may be coated with vibration-damping material. Alternatively, a separate vibration-damping elastic piece may be arranged between the joint surfaces. Further, it is possible to arrange a mechanical vibration-damping structure to the joint surfaces between the components. The mechanical structure may be based on a spring member, for example. The operation of the damping element may also be based on the use of a pressure medium, for instance.

[0043] Figure 10 also shows by a dashed line a coating 32 that is arranged around the feed beam 6 and may be made of suitable elastic material, such as plastic or rubber. The coating 32 may surround the feed beam entirely, or the coating 32 may be arranged to cover all other portions of the feed beam except the guiding surfaces. Correspondingly, it is possible to arrange coatings around the other components of the rock drilling unit 3. Thus, for instance the carriage 7 and drilling machine 4 may be furnished with coat- ings 33, 34. The coatings may absorb vibration and cause it to reflect back. Further, in some cases, the coating may act as a vibration-isolating layer between components.

[0044] In the embodiment shown in Figure 1 1 , the rock drilling machine 4 and feed beam 6 and a possible carriage 7 are arranged inside a protective casing 10. One or more side surfaces of the protective casing 10 may be equipped with means for attaching them to a cradle. The attachment means may include guide beams 36 or the like with support surfaces 15. In this embodiment, the protective casing 10 may be made fully closed, because there is no need to arrange an opening for the movement between the cradle and feed beam. The sound-proofing of the protective casing 10 may be improved by making it as tight as possible. The feed beam 6 fastens to the cradle through the protective casing 10 and guide beam 36. The material of the protective casing 10 may be selected to isolate the transmission of vibration from the feed beam 6 to the cradle. Naturally, it is possible to arrange damping elements of the type described above to the connecting point between the protective casing 10 and feed beam 6 as well as between the protective casing 6 and guide beam 36.

[0045] Figure 12 shows a feed beam 6, the cross-section of which comprises two beam parts 6a and 6b that are on top of each other and fastened stationary to each other during use and together form a feed beam that is sufficient in rigidity and other properties. The protective casing 10 may be fastened to the cradle-side beam part 6b. The fastening points of the protective casing 10 may be equipped with damping-elements 37 that may be of the type described in this patent application. In this embodiment, the feed beam 6 forms part of the protective casing 10, since the lower feed beam part 6b in the figure forms the bottom part of the protective casing 10.

[0046] Further, it is possible to apply the damping elements and other arrangements described in this patent application not only to the rock drilling unit but also to other mining units, where instead of the rock drilling machine some other power tool causing harmful vibration, such as a bolting machine, is used as the mining tool.

[0047] Figures 13 to 18 show yet other feed beam solutions that may differ from the embodiments described above.

[0048] Figure 13 shows the cross-section of a feed beam 6 that comprises a first feed beam part 6a on the rock drilling machine-side and a second feed beam part 6b on the cradle side. The feed beam parts 6a and 6b are fastened stationary to each other, and they form together a feed beam for supporting a rock drilling machine. The feed beam parts 6a, 6b may be of substantially the same length as the feed beam 6. The feed beam 6 may be as though split in the middle, or asymmetrically, into two longitudinally overlapping parts. In some cases the feed beam may comprise feed beam parts that are shorter than the entire feed beam. For instance, the second feed beam part 6b may comprise one, two or more shorter parts that are separately fastened to the first feed beam part 6a. In this case, too, a cross-section of the feed beam 6 comprises at least one first feed beam part 6a and at least one second feed beam part 6b arranged on top of each other.

[0049] Figure 14 shows a feed beam 6 made up of several longitudinal parts. The cross-section of the feed beam 6 may have a first feed beam part 6a on the drilling machine side and a second feed beam part 6b on the cradle side, and at least the latter may be divided into two or more components 18a, 18b. Between the feed beam parts 6a and 6b, there may be suitable form- lock members, such as a projecting portion 19 and a space 20 receiving it, as described in connection with the embodiment of Figure 5. Corresponding principles also apply to the embodiment of Figure 14. In some cases there may be several feed beam parts on top of each other, and it is further possible that the first feed beam part 6a also consists of two or more components in the transverse direction C.

[0050] In Figure 15, a side wall 10a of a protective casing 10 is arranged between the first and second feed beam parts 6a, 6b that are on top of each other. The protective casing 10 may be made of a thin steel plate that has been found to have good vibration transmission damping.

[0051] It should further be noted that the feed beam formed of feed beam parts may be arranged to form part of the protective casing surrounding the rock drilling machine. The protective casing may then be fastened to the first or second feed beam part or arranged between their connecting surfaces. Alternatively, the two-part feed beam is not part of the casing. The protective casing may then be arranged around the feed beam.

[0052] A common factor for each feed beam of a rock drilling rig shown in Figures 13 to 15 is that the feed beam is an elongated piece and at least part of its cross-section comprises at least one first feed beam part 6a and at least one second feed beam part 6b arranged on top of each other and stationary relative to each other. In addition, the feed beam may comprise in the first feed beam part 6a first support surfaces 14, to which the rock drilling machine 4 is movably supported, and in the second feed beam part 6b second support surfaces 15, with which the feed beam 6 is fastened to the rock drilling rig.

[0053] Figures 16 to 18 show yet other rock drilling units whose feed beams differ from the embodiments described above.

[0054] Figure 16 shows a feed beam 6 with a trough-shaped cross- section having a bottom section 6c and two side sections 6d. The side sections 6d may extend equidistant from the bottom section 6c or, alternatively, their heights may differ, as shown in Figures 17 and 18. The rock drilling machine 6 may be arranged in a carriage 7 in the manner shown in Figures 16 and 18. The carriage 7 may be supported using suitable slide blocks 16 or the like to the bottom section 6c and side sections 6d. The bottom section 6c may also have guiding surfaces or the like, to which the carriage 7 may be supported. In Figure 17, the drilling machine 4 is supported directly to the feed beam 6 without a carriage.

[0055] In Figures 16 to 18, the trough-shaped feed beam 6 or one that has a U-shaped section acts as part of the casing surrounding the rock drilling machine 4. The trough-shaped feed beam 6 may be closed with a lid 38 that may be connected with a hinge 39, for example, to the top part of the side section 6d, whereby the lid 38 can be opened and closed for maintenance and drill rod change, for instance.

[0056] Possible coatings arranged on the feed beam 6 are marked with dashed lines 32 in Figure 16. A coating 32 made of a vibration-damping or isolating material may be arranged on the inside surfaces of the trough-shaped section of the feed beam 6, on the outside surfaces of the feed beam or on both the inside and outside surfaces.

[0057] In the embodiments of Figures 16 to 18, it is possible to apply the solutions disclosed in this patent application for damping vibration and preventing vibration transmission between components.

[0058] In the embodiment shown in Figure 18, the feed beam 6 is formed of two feed beam parts 6a and 6b on top of each other. The cross- section of the first feed beam part 6a is substantially U-shaped. The second feed beam part 6b is equipped with means for attaching it to a cradle. [0059] A common factor for each feed beam of a rock drilling rig shown in Figures 16 to 18 is that the feed beam 6 is an elongated piece, whose rock drilling machine-side section comprises a trough-shaped cross- section with a bottom section 6c and two side sections 6d at a distance from each other. The rock drilling machine-side section may thus have a substantially U-shaped cross-section. The rock drilling machine 4 is moved inside the trough-shaped section. The trough-shaped feed beam forms together with the openable lid 38 a protective casing around the rock drilling machine 4.

[0060] Figures 19 and 20 show a lead-through element 40 which may be fastened to the protective casing 10 and with which the necessary pressure medium connections, electric connections and other possible connections may be arranged between the outside and inside of the protective casing 10. It has been found that drilling noise can be significantly reduced, if the sealing of the protective casing can be improved. By means of the lead-through element 40, different connections can be concentrated in one location and the lead-through element 40 can also be fastened tightly to the protective casing 10.

[0061] As shown in Figure 19, the lead-through element 40 comprises a connecting plate 41 that may be fastened by a screw joint, for instance, at a lead-through opening 42 in the body of the protective casing 10. One or more damping elements 43 may be arranged between the connecting plate 41 and protective casing 10 to prevent vibration transmission between the inter-connected components. Further, there may be one or more sealings 44 between the connecting plate 41 and protective casing 10, whereby the connecting plate 41 may be fastened tightly to the protective casing 10. The connecting plate 41 has openings 45, to which necessary couplers 46 may be fastened for connecting hydraulic hoses, pressurized air hoses, electric cables and the like. Thanks to the couplers 46, disconnecting and re-connecting connections is fast and easy during maintenance, for instance.

[0062] The lead-through element shown in Figures 19 and 20 is characterised in that the lead-through element 40 comprises a connecting plate 41 that is equipped with couplers 46 for leading pressure medium channels through the connecting plate and, further, that there is at least one sealing 44 at the connecting plate 41 . A rock drilling rig protective casing of the type shown in Figures 19 and 20 is characterised in that all the pressure medium channels required by the operation of the rock drilling machine are led through at least one lead-through element 40 between the inside and outside of the protective casing, and that the connecting plate 41 is fastened tightly to the protective casing 10.

[0063] In some cases, the features described in this patent application may be used as such, regardless of other features. On the other hand, the features described in this patent application may also be combined to provide various combinations as necessary.

[0064] The drawings and the related description are only intended to illustrate the idea of the invention. The invention may vary in its details within the scope of the claims.

Claims

1 . A rock drilling unit that comprises:

a rock drilling machine (4);

an elongated feed beam (6), to which the rock drilling machine (4) is supported;

a feed device (8) for moving the rock drilling machine (4) in the longitudinal direction (A) of the feed beam (6); and

a fastening member (9) which is connected to the feed beam (6) and with which the rock drilling unit (3) is to be fastened to a rock drilling rig;

the rock drilling unit (3) having at least one damping element (13) for damping the vibration caused by the operation of the rock drilling machine (4) in a component belonging to the rock drilling unit (3) or vibration transmission between the components of the rock drilling unit (3);

c h a r a c t e r i s e d i n t h a t

the feed beam (6) comprises at least two feed beam parts (6a, 6b) arranged on top of each other, the first feed beam part (6a) being on the side of the rock drilling machine (4) and the second feed beam part (6b) being on the side of the fastening member (9); and

between the first feed beam part (6a) and second feed beam part (6b), there is at least one damping element (13) that separates the joint surfaces of the feed beam parts (6a, 6b) from each other.

2. A feed beam of a rock drilling rig, which is an elongated piece and comprises:

first support surfaces (14), to which the rock drilling machine (4) is movably supported; and

second support surfaces (15), with which the feed beam (6) is to be connected to the rock drilling rig,

c h a r a c t e r i s e d i n t h a t

the cross-section of the feed beam (6) comprises at least one first feed beam part (6a) and at least one second feed beam part (6b) that are of equal length with the feed beam and fastened to each other one on top of the other; and

between the first feed beam part (6a) and second feed beam part (6b), there is at least one damping element (13) that is arranged to damp vibration in the feed beam (6) or prevent vibration transmission between the feed beam parts.

3. A feed beam as claimed in claim 2, characterised in that the second feed beam part (6b) is formed of two elongated pieces

(18a, 18b) that are connected to each other in the lateral direction (C) of the feed beam.

4. A feed beam as claimed in claim 3, characterised in that the cross-sectional profile of the first feed beam part (6a) comprises a projecting part (19) that is directed toward the second feed beam part (6b); and

the elongated pieces (18a, 18b) of the second feed beam part (6b) are arranged to receive the projecting part (19) and form a form-lock with the projecting part (19).

5. A feed beam as claimed in any one of preceding claims 2 to 4, characterised in that

at least one protective casing (10) is fastened to the feed beam (6); and

part of the protective casing (10) is arranged between the joint surfaces of the feed beam parts (6a, 6b).

6. A feed beam as claimed in any one of preceding claims 2 to 5, characterised in that

the damping element (13) is made of elastic material.

7. A method for damping vibration in a rock drilling unit,

the rock drilling unit comprising: a rock drilling machine (4); feed beam (6); feed device (8) for moving the rock drilling machine (4) in the longitudinal direction (A) of the feed beam; and fastening member (9) which is connected to the feed beam (6) and with which the rock drilling unit (3) is to be fastened to a rock drilling rig;

wherein vibration caused by the operation of the rock drilling machine (4) in the rock drilling unit (3) is damped by means of at least one damping element (13);

characterised by

forming the feed beam (6) of at least two parts (6a, 6b), and arranging at least one damping element (13) between their joint surfaces to prevent the transmission of vibration through the feed beam (6).