EP4589115A1

EP4589115A1 - Protective device, method, and rock drilling unit

Info

Publication number: EP4589115A1
Application number: EP24152602.9A
Authority: EP
Inventors: Aleksi MÄKILOUKO
Original assignee: Sandvik Mining and Construction Oy
Current assignee: Sandvik Mining and Construction Oy
Priority date: 2024-01-18
Filing date: 2024-01-18
Publication date: 2025-07-23
Also published as: WO2025153251A1

Abstract

A protective device (8), a rock drilling unit (4) and a method for providing protection in a rock drilling unit. The protective device comprises a protective casing (9) mountable to surround a drilling tool (7) connected to a rock drilling machine (6). The protective casing is a volute spring (10) which is a compression spring coiled of flat strip material (13) to a volute and forming inside the volute spring a longitudinally elastic tool space (15) for receiving the drilling tool.

Description

Background of the invention

The invention relates to a protective device ar-rangeable around a drilling tool of a rock drilling rig.
The invention further relates to a rock drilling unit provided with a protective device, and a method for providing protection in a rock drilling unit.
The field of the invention is defined more specifically in the preambles of the independent claims.
In mines, construction sites and at other work areas different type of rock drilling rigs are used for drilling holes for different purposes. The rock drilling rigs are provided with one or more booms and rock drilling units are arranged at distal ends of the booms for drilling the drill holes. During drilling rotating drilling tools are provided with impact pulses. There exists a need to use protective devices around the drilling tools. This is the case particularly in surface drilling. However, the present protective devices have shown to contain some disadvantages regarding their complicated, expensive and clumsy structure.

Brief description of the invention

An object of the invention is to provide a novel and improved protective device and method for a rock drilling unit. The invention further relates to a novel and improved rock drilling unit implementing the protective device.
The protective device according to the invention is characterized by the characterizing features of the first independent apparatus claim.
The rock drilling unit according to the invention is characterized by the characterizing features of the second independent apparatus claim.
The method according to the invention is characterized by the characterizing features of the independent method claim.
An idea of the disclosed solution is that a protective device comprises a protective casing which is mountable to surround a drilling tool connected to a rock drilling machine. The protective casing is a volute spring which is a compression spring coiled of flat strip material to a volute and forming inside the volute spring a longitudinally elastic tool space for receiving the drilling tool.
In other words, the volute spring is implemented to form a continuously telescoping protective structure to surround the drilling tool on a feed beam of the rock drilling unit. The volute spring forms a longitudinally continuous elastic structure made of rigid material.
An advantage of the disclosed solution is that the volute spring is a simple, inexpensive, and robust structure which is now implemented in a new way as a protective casing and not as a conventional spring element.
The volute spring is a rigid structure so that it can remain in its position coaxially around the drilling tool without coming in physical contact with the drilling tool even though reach of the volute spring is long in the disclosed implementation. Further, the volute spring can be made of material that withstands well harsh conditions at the drilling site and tolerates also external forces, vibration, and wear.
The coils of the flat strip material overlap each other and are guided radially by each other during compression of the volute spring, thus giving the volute spring stability against bending.
According to an embodiment, the volute spring is made of rigid metallic material, such as steel.
According to an embodiment, compressed minimum length of the volute spring is less than 160 mm and free length or equilibrium length of the volute spring, is at least 2850 mm, whereby range of the volute spring can be huge. In the equilibrium length the volute spring is not compressed nor stretched. It should be noted that maximum length of the volute spring can of course be much greater than the equilibrium length.
According to an embodiment, the tool space is a closed space during the drilling operation when the drilling tool is passing through the device. An advantage is that noise reduction is improved when closed airtight space is surrounding the object being isolated.
According to an embodiment, the volute spring has a continuous homogenous structure extending from end to end. Thus, the volute spring has a one-piece uniform structure which is telescopically elastic in longitudinal direction. Thus, only one volute spring is enough for covering length of the drilling tool present on the feed beam.
According to an embodiment, the protective casing is a physical shield structure or guard configured to prevent access to the rotating drilling tool. Thus, the volute spring can serve as a physical safety device preventing contact with rotating parts, such as a rotating drilling tool or a rotating shank wherein the drilling tool is coupled. There is not necessarily need for sound isolation and absorbing means.
According to an embodiment, the protective casing is a sound isolating structure mountable to surround the drilling tool. Then the volute spring may be a dual-purpose element serving as a noise protecting element and also as a physical guarding element.
According to an embodiment, the volute spring comprises at least one layer of noise absorbing material on inner surfaces limiting the tool space. In other words, the absorbing material arranged on the inner surfaces receives acoustic waves and changes their acoustic energy into heat inside the absorbing material.
According to an embodiment, the inner surfaces of the strip of the volute spring are coated with noise absorbing material.
According to an embodiment, a separate noise absorbing material layer is attached on the inner surface of the strip of the volute spring.
According to an embodiment, the noise absorbing material is porous material comprising small cavities. When sound propagates in the small spaces, it loses energy.
Acoustic porosity is one of the most important factors in sound absorbing properties of material. Porous material may be of polyurethane (PU) composite foam, or other polymeric materials or foams, for example. It is also possible to use sound insulating wool materials, such as acoustic mineral wools and rock wools.
According to an embodiment, the inner surfaces are provided with protruding elements for facilitating attaching of the noise absorbing material. The absorbing material may be a separate sheet material element and its fastening may be based on adhesive fastening, mechanical fastening or combination of the adhesive and mechanical fastening principles.
According to an embodiment, edge portions of the strip material of the volute spring are provided with seals. In other words, the edges of the strip material of the volute spring are sealed for further improving airtightness inside the tool space. The sealing can block possible clearances between the coils. The airtightness is an important feature for the sound isolation.
According to an embodiment, the seals are made of rubber or rubber-like sealing material.
According to an embodiment, the seals are made of low friction sealing material. Then the sealing material slides better, and less loading is directed to the fastening of the seals. Due to the low friction less reduction to feed forces may also occur.
According to an embodiment, the seals are formed of a continuous sealing strip coiled on the edge portions. Thus, the sealing strip is a separate element attached to the volute spring and extending end to end.
According to an embodiment, the device comprises a first fastening element at a first end of the volute spring and a second fastening element at an opposite second end of the volute spring whereby the volute spring is supportable between a front end portion of a feed beam and a rock drilling machine. In other words, one of the first and second fastening elements can be mounted immovably to a front end portion of the feed beam and one of the first and second fastening elements can be mounted to a front end portion of the rock drilling machine or to a carriage on which the rock drilling machine is mounted. Thus, one end of the volute spring is immovable in relation to the feed beam and another opposite end is movable in relation to the feed beam during the drilling operation.
According to an embodiment, the device is without any intermediate support elements between the ends of the volute spring.
According to an embodiment, the device comprises vibration dampers for isolating the device from vibrations of the rock drilling unit. The vibration dampers are arranged in connection with the fastening elements.
At least the fastening elements at the side of the rock drilling machine comprise vibration dampers for isolating the device from vibrations of the rock drilling machine. This way, transfer of vibrations from the rock drilling unit to the device can be prevented or decreased and vibration born noise in the device can be avoided or decreased.
Further, it has been noted that the structure of the volute spring is as such of noise dampening type and can dampen vibrations caused by the rock drilling machine.
According to an embodiment, the first end of the volute spring has greater diameter than the second end. The first end with the greater diameter is provided with first fastening elements for mounting to the front end of feed beam, and the second end with the minor diameter is provided with second fastening elements for mounting to the rock drilling machine or to a carriage. There may be more available space for the first end with the greater diameter at the front end of the feed beam.
According to an alternative embodiment, the volute spring is arranged vice versa compared to the previous embodiment. The first end with the greater diameter is provided with the first fastening elements for mounting to the rock drilling machine or to a carriage, and the second end with the minor diameter is provided with second fastening elements for mounting to the front end of feed beam.
According to an embodiment, the device comprises end sealing elements at both ends of the volute spring for providing the tool space with airtight axial ends. In other words, the volute spring forms a tight cover and now the tightness of the tool space is completed by means of the sealed ends.
According to an embodiment, at least at one end of the device is a sealing plate with a central opening through which the drilling tool can penetrate. The opening is surrounded with a resilient sealing material.
According to an embodiment, at least at one end of the device is a sealing element to be mounted between a fastening element of the volute spring and a cover plate of a flushing housing of the rock drilling machine. In an alternative structure the sealing element may cover the flushing housing at least partly.
According to an embodiment, the volute spring has overlapping coil areas where longitudinal edges of the coiled flat strip material overlap each other. Further, magnitude of generated restoring force of the volute spring is dimensioned to compress the overlapping coil areas against each other for providing airtight fitting and rigid extendable joint between the edges of the coiled strip. In other words, magnitude of the restoring force or spring force can be dimensioned to be relatively low since the force is needed only for providing the tool space with the needed air tightness and for providing the volute spring with self-supporting properties.
The volute spring does not act as a spring element as such, but it is a protective and isolating element surrounding the drilling tool.
As a matter of fact, the spring force of the volute spring is minimized because the spring force extending the volute spring needs to be compensated by feed forces in a drilling direction. Thus, a feed device needs to compress the volute spring during the drilling.
However, the restoring force of the volute spring can be implemented to keep the volute spring being constantly pushed against its fastening elements at the ends of the volute spring. Then, the volute spring is automatically set to proper length and there is no need to pull the volute spring. This may be beneficial when designing and dimensioning fastening elements of the volute spring. In other words, the spring force tries to extend the volute spring to a designed equilibrium length.
Magnitude of the spring force increases as the volute spring is compressed. Thus, the spring force is in its maximum when the rock drilling machine is moved to its front most position and the volute spring is fully retracted.
According to an embodiment, at one end of the volute spring is a locking device for selectively locking the volute spring into compressed state and releasing the volute spring to move towards a free length of the volute spring. In other words, the volute spring can be locked after being compressed into its minimum length. This way the protective structure can be packed into small space when it is not needed. The compressed volute spring takes only very little space in the axial direction and thereby does not form visibility obstacles nor act as a barrier on the feed beam. The compressed and locked state can also be utilized when changing the drilling tools.
According to an embodiment, the locking device comprises at least one remote or automatically controlled actuator.
According to an embodiment, the disclosed solution relates also to a rock drilling unit comprising: a feed beam; a rock drilling machine supported on the feed beam; a feed device for moving the rock drilling machine in a drilling direction and reverse direction; and a protective device comprising a protective casing surrounding at least a drilling tool mountable to the rock drilling machine. The protective device is in accordance with the features and embodiment disclosed in this document and comprises a volute spring serving as the protective casing. Further, one end of the volute spring is mounted to a front end portion of the feed beam and another opposite end is arranged to face a front portion of the rock drilling machine whereby length of the volute spring is configured to adjust freely in response to movements of the rock drilling machine in the feed direction and in the reverse direction.
According to an embodiment, the volute spring has an end with a greater diameter and another end with a smaller diameter. The end of the volute spring with the greater diameter is mounted immovably to a front end portion of the feed beam and the end with the smaller diameter is connected to the rock drilling machine.
According to an embodiment, one end of the volute spring is provided with selectively connectable and releasable fastening element whereby one end of the volute spring can be released. In other words, the volute spring can be uncoupled at one end after being compressed into its minimum length. Thus, the rock drilling machine can be moved in the drilling direction to its front most position wherein connection between the volute spring and the rock drilling machine can be released. There are also locking means for keeping the volute spring in the compressed state so that the rock drilling machine can be moved in the reverse direction without the volute spring following the movement. This way, it is possible to change the drilling tool. When the tool change is completed, the volute spring can be released so that the drilling can proceed in a protected state. The released volute spring can be recoupled to the rock drilling machine. The coupling and locking can be executed by means of remote controlled actuators arranged to move suitable quick coupling elements. This feature can be implemented for example when changing the drilling tool, or when adding new drill rods in extension drilling.
According to an embodiment, the disclosed solution relates also to a method for providing protection in a rock drilling unit. The method comprises: arranging a protective casing to surround a drilling tool connected to a rock drilling machine of the rock drilling unit; and using as the protective casing a volute spring and forming a longitudinally elastic element between a front end portion of a feed beam of the rock drilling unit and the rock drilling machine.
According to an embodiment, the method further comprises providing an airtight tool space inside the volute spring for the drilling tool by sealing at least ends of the volute spring.
According to an embodiment, the method further comprises dampening noise inside the volute spring by means of noise absorbing material arranged inside the volute spring.
The above disclosed embodiments may be combined in order to form suitable solutions having those of the above features that are needed.

Brief description of the figures

Some embodiments are described in more detail in the accompanying drawings, in which

Figure 1 is a schematic side view of a rock drilling rig for surface drilling and being provided with a protective device;
Figure 2 is a schematic diagram of some features of a protective device;
Figure 3 is a schematic and cross-sectional side view of a principle of a volute spring;
Figure 4 is a schematic side view of drilling unit provided with a protective casing surrounding a drilling tool;
Figure 5 is a schematic view of some components of a protective casing;
Figure 6 is a schematic view of a front end portion of a drilling unit provided with a protective casing; and
Figure 7 is a schematic view of a rear end portion of a drilling unit provided with a protective casing.

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 of some embodiments

Figure 1 discloses a rock drilling rig 1. The rock drilling rig 1 comprises a movable carrier 2 and at least one boom 3 connected to the carrier 2. At a distal end portion of the boom 3 is a drilling unit 4. The drilling unit 4 comprises a feed beam 5 and a rock drilling machine 6 movable by means of a feed device 27 on the feed beam 5. The rock drilling machine 6 may comprise a rotating device for rotating R a drilling tool 7. The rock drilling machine 6 may also comprise an impact device, which generates impact pulses for the drilling tool 7. A protective device 8 is arranged to surround the drilling tool 7. The protective device 8 may provide physical protection by preventing access to the rotating drilling tool 7 and may also serve as a noise dampening structure for lowering noise level caused by the rock drilling machine 6 during drilling operation. The protective element is in accordance with the features and embodiments disclosed in this document.
In Figure 1 a surface rock drilling rig is disclosed. However, it is of course possible to implement the disclosed protective device also in other type of drilling rigs and drilling machines. Thereby, the disclosed solution may be implemented in rock drilling rigs intended for underground drilling and may be used also in rotary and DTH drilling as well as in exploration drilling.
Figure 2 discloses that a protective element 8 comprises a protective casing 9 which is formed of a volute spring 10. The volute spring 10 can serve as a noise isolating structure 11 around a drilling tool and as a physical shield 12 providing safety by preventing possibility of an operator or anyone else working at a drilling work site from clinging to the rotating drilling tool.
Figure 3 discloses a basic principle of a volute spring 10 in a simplified manner. The volute spring 10 is a compression spring coiled of flat strip material 13 to a volute. The coiling can be seen by means of slanted edges 14 of the strip material 13, for example. Inside the volute spring 10 is a longitudinally elastic tool space 15 for receiving a drilling tool 7. When the volute spring 10 is serving as a noise isolating structure, both ends of the volute spring 10 may be provided with end sealing elements 16, 17 for providing the tool space 15 with airtight axial ends. Figure 3 further discloses that the volute spring 10 has overlapping coil areas 18 where longitudinal edges of the coiled flat strip material 13 overlap each other. The volute spring 10 can be compressed into a minimum compressed length Lc and can be extended to an extended length Le. The volute coil 10 has a maximum extended length and also an equilibrium length wherein the volute spring is not subject to any compressing or extending forces.
Figure 4 discloses a rock drilling unit 4 wherein a volute spring 10 is mounted between a front end portion 5a of a feed beam 5 and a rock drilling machine 6. There is a first fastening element 19 at the first end 5a for mounting the volute spring 10 to a feed beam 5. A second fastening element 20 is located at an opposite second end of the volute spring 10 to fasten the volute spring 10 to a rock drilling machine 6, or alternatively, to a carriage 21 on which the rock drilling machine 6 is moved on the feed beam 5. When the rock drilling machine 6 moves in a drilling direction A and in a reverse direction B, the volute spring 10 adjusts its length. Thereby, the volute spring 10 forms a protective casing 9 with a longitudinally elastic structure. As can be seen, a drilling tool 7 is fully covered by the volute spring 19 for the entire length of the feed beam 5. Figure 4 further shows that at the front end portion 5a there may be a housing 22 for receiving the volute spring 10 when being compressed into its minimum length by moving the rock drilling machine 6 in the drilling direction A. In connection with the housing 22 may be a locking element 23 for keeping the volute spring 10 in the fully compressed state. Further, in connection with the second fastening element 20 there may be an actuator 24 for selectively coupling and releasing the second fastening element under remote control. The locking element 23 and the actuator 24 can be operated when there is a need to open a tool space provided by the volute spring 10. This way, change of the drilling tool 7 is possible.
Figure 5 discloses some components of a protective casing 9. A volute spring 10 may as such provide a needed protective structure around a drilling tool 7. However, when proper noise isolation is required, then a layer of noise absorbing material 25 may be provided on inner surfaces limiting a tool space 15 provided by the volute spring 10. Further, edge portions 14 of a strip material 13 of the volute spring 10 can be equipped with seals 26 for improving air tightness of the tool space 15 and thereby improving noise isolation. The seals 26 can also be seen in Figure 4.
Figure 6 discloses mounting of a volute spring 10 to a front end portion 5a of a feed beam 5. Figure 7 discloses mounting of the volute spring 10 to front end of a rock drilling machine 6. Fastening elements 20 may be arranged around a flushing housing 28, for example.
The drawings and the related description are only intended to illustrate the idea of the invention. In its details, the invention may vary within the scope of the claims.

Claims

A protective device (8) for a rock drilling unit (4), wherein the device (8) comprises:
a protective casing (9) mountable to surround a drilling tool (7) connectable to a rock drilling machine (6) of the rock drilling unit (4);

characterized in that

the protective casing (9) is a volute spring (10) which is a compression spring coiled of flat strip material (13) to a volute and forming inside the volute spring (10) a longitudinally elastic tool space (15) for receiving the drilling tool (7).
The device as claimed in claim 1, characterized in that
the volute spring (10) comprises at least one layer of noise absorbing material (25) on inner surfaces limiting the tool space (15).
The device as claimed in claim 1 or 2, characterized in that
edge portions (14) of the strip material (13) of the volute spring (10) are provided with seals (26).
The device as claimed in any one of the preceding claims 1 - 3, characterized in that
the device (8) comprises a first fastening element (19) at a first end of the volute spring (10) and a second fastening element (20) at an opposite second end of the volute spring (10) whereby the volute spring (10) is supportable between a front end portion (5a) of a feed beam (5) and a rock drilling machine (6).
The device as claimed in any one of the preceding claims 1 - 4, characterized in that
the device (8) comprises end sealing elements (16, 17) at both ends of the volute spring (10) for providing the tool space (15) with airtight axial ends.
The device as claimed in any one of the preceding claims 1 - 5, characterized in that
the volute spring (10) has overlapping coil areas (18) where longitudinal edges (14) of the coiled flat strip material (13) overlap each other;

and magnitude of generated restoring force of the volute spring (10) is dimensioned to compress the overlapping coil areas (18) against each other for providing airtight fitting and rigid extendable joint between the edges (14) of the coiled strip (13).
The device as claimed in any one of the preceding claims 1 - 6, characterized in that
at one end of the volute spring (10) is a locking device (23) for selectively locking the volute spring (10) into compressed state and releasing the volute spring (10) to move towards a free length of the volute spring (10).
The device as claimed in any one of the preceding claims 1 - 7, characterized in that
the protective casing (9) is a sound isolating structure (11) mountable to surround the drilling tool (7).
The device as claimed in any one of the preceding claims 1 - 8, characterized in that
the protective casing (9) is a physical shield structure (12) configured to prevent access to the rotating (R) drilling tool (7).
A rock drilling unit (4) comprising:
a feed beam (5);

a rock drilling machine (6) supported on the feed beam (5);

a feed device (27) for moving the rock drilling machine (6) in a drilling direction (A) and reverse direction (B); and

a protective device (8) comprising a protective casing (10) surrounding at least a drilling tool (7) mountable to the rock drilling machine (6);

characterized in that

the protective device (8) is in accordance with the device (8) disclosed in the previous claims 1 - 9 and comprises the volute spring (10) as the protective casing (9);

one end of the volute spring (10) is mounted to a front end portion (5a) of the feed beam (5) and another opposite end is arranged to face a front portion of the rock drilling machine (6) whereby length of the volute spring (10) is configured to adjust freely in response to movements of the rock drilling machine (6) in the feed direction (A) and in the reverse direction (B).
The rock drilling unit as claimed in claim 10, characterized in that
the volute spring (10) has an end with a greater diameter and another end with a smaller diameter;

the end of the volute spring (10) with the greater diameter is mounted immovably to a front end portion (5a) of the feed beam (5) and the end with the smaller diameter is connected to the rock drilling machine (6).
The rock drilling unit as claimed in claim 10 or 11, characterized in that
one end of the volute spring (10) is provided with selectively connectable and releasable fastening element (20) whereby one end of the volute spring (10) can be released.
A method for providing protection in a rock drilling unit (4),
wherein the method comprises:
arranging a protective casing (9) to surround a drilling tool (7) connected to a rock drilling machine (6) of the rock drilling unit (4);

characterized by

using as the protective casing (9) a volute spring (10) and forming a longitudinally elastic element between a front end portion (5a) of a feed beam (5) of the rock drilling unit (4) and the rock drilling machine (6).
The method as claimed in claim 13, characterized by
providing an airtight tool space (15) inside the volute spring (10) for the drilling tool (7) by sealing at least ends of the volute spring (10).
The method as claimed in claim 13 or 14, characterized by
dampening noise inside the volute spring (10) by means of noise absorbing material (25) arranged inside the volute spring (10).