The invention relates to a sound dampening housing for a rock drill which moves along a feed beam in a longitudinal direction thereof, the sound dampening housing being attachable to the feed beam of the rock drill on its both sides so that together with the feed beam the sound dampening housing constitutes a substantially closed space within which the rock drill and at least a main part of a drill rod outside a hole are located.
When drilling rock, drill rigs are used that comprise one or more booms mounted on a base and a drill movably mounted on a feed beam provided on the boom(s). Often the feed beam is also installed at an end of a boom movably in its longitudinal direction by a separate cradle so as to enable the feed beam to be arranged in a desired position and in a desired direction for drilling. In view of these various movements of the boom and the feed beam, the drill rig is provided with various transfer cylinders or hydraulic motors known per se that are driven by pressure fluid.
A typical problem in rock drilling is noise. The noise is produced by a rock drill impacting on a head of a tool and the tool impacting on rock, as well as by various other movements, such as rotation, etc. The noise, which propagates even quite widely to the neighbourhood, keeps causing more and more problems, particularly in the vicinity of housing areas. In order to prevent the noise from causing restrictions on working hours or sites, attempts have been made to solve the issue particularly in surface drilling by using various noise damping housings around the feed beam and the drill. Such solutions are known e.g. from WO 2006/038850, WO 00/39412, SE 523874, U.S. Pat. No. 3,667,571, and JP 5-295978. The problem with all these solutions is that they are difficult to implement or they do not dampen the noise over the entire area of the drill. In addition, the mechanical apparatuses used for opening the sound dampening housing when replacing or adding a drill rod are complex and laborious. Further, the sound dampening housings are quite large and heavy, which makes them difficult to manufacture and use.
An object of the present invention is to provide a sound dampening housing with a lighter structure and a better sound dampening capability.
The sound dampening housing according to the invention is characterized in that at least part of the sound dampening housing is formed from two shells, i.e. an inner shell and an outer shell, arranged one within another and attached to one another so as to form a substantially stiff unity and a space containing air or another gas or a gaseous mixture being provided therebetween.
An idea underlying the invention is that the sound dampening housing is at least partly double-shelled such that it comprises an inner shell, i.e. an inner surface layer, and an outer shell, i.e. an outer surface layer, an airspace being provided therebetween so as to produce a stiff and sound dampening structure. According to an embodiment of the invention, the sound dampening housing is formed from a plurality of housing components attached to one another, each component being double-shelled.
An advantage of the sound dampening housing according to the invention is that when a double-shell structure is used wherein only air is provided between the shells, the result is a sound damping housing whose structure is stiff and whose dampening properties are good but which, nevertheless, is quite light. It is also easy to manufacture such a sound dampening housing from appropriately dimensioned and shaped components since the components are easy to attach to one another such that also the joints can be made noise insulating.
The invention will be described in closer detail in the accompanying drawings, in which
One end of the boom 4, rotatably therewith, is provided with a cradle 5 which, in turn, is provided with a feed beam 6 movable in its longitudinal direction. The feed beam 6 may be moved with respect to the cradle 5 by a pressure medium cylinder 6a in a manner known per se. The feed beam 6 is provided with a rock drill (not shown) known per se for drilling holes by means of a tool, i.e. a drill rod, shown in connection with
For installation and removal of the drill rod, a sufficiently large and long opening is to be provided between the sound dampening housing 7 and the cover part 7a. Therefore, in the longitudinal direction of the sound dampening housing 7 and the feed beam 6 the transfer cylinders 12 are situated at a distance from one another enabling the drill rod 9 to be moved from between the transfer cylinders 12 in between the sound dampening housing 7 and the cover part 7a and, correspondingly, away therefrom. The travelling length of the transfer cylinders 12 may be selected differently. They may either be equal in length or their travelling length may be different on different sides of the sound dampening housing, in which case the cover part 7a is, in a manner of speaking, made to turn in a transverse direction of the sound dampening housing 7 a distance out of the way of the drill rod.
Various intermediate parts interconnecting the shells may be provided between the shells, such as sleeve-like lead-throughs, for attaching different parts to the sound dampening housing. The cross-section of the outer shell and the inner shell is shaped such that on one hand they stiffen the sound dampening housing and on the other hand they dampen noise as well as possible. This, on one hand, enables a robust structure to be achieved and, on the other hand, the cover part 7a of the sound dampening housing to be moved so that it becomes attached to the sound dampening housing 7 tightly and steadily such that the gap therebetween is sealed and noise-dampening remains efficient.
It is particularly to be noted herein that a way to seal a seam between the cover part 7a and the sound dampening housing 7 is to use slanting surfaces 16a and 16b in the edges of the sound dampening housing and the cover part such that when the cover part 7a is moved so that it becomes attached to the sound dampening housing, the slant surfaces 16a and 16b are pressed against one another, constituting a compressed sealing joint. The seams between the cover part 7a and the rest of the sound dampening housing may, of course, also be sealed by separate seals in manners known per se.
In both shells 13a and 13b, respectively, ribs 17a to 17d can be seen. In the shell 13a, the longitudinal ribs 17a reside on the side of the airspace 13c between the shells 13a and 13b while the rib 17b, which, in a manner of speaking, is a fold formed in the shell, in turn resides on the inside of the shell 13a, i.e. in the same space as the rock drill. Similarly, in the shell 13b, a longitudinal rib 17c and a transverse rib 17d are both provided on the side of the airspace 13c between the shells 13a and 13b. Such ribs may be provided only in one of the shells or in both shells, either longitudinally or transversely. Further, they may be provided either on the outside or inside of a shell. If a rib is provided between shells, it may even extend all the way to the other shell. The ribs serve to stiffen a shell, if so required by the material of the shell. The ribs may be either completely solid or they may be hollow or folds provided in a shell.
The travelling length of the transfer cylinders 12 may be selected in different ways. They may be either equal in length or their travelling length may be different in different sides of the sound dampening housing, enabling, in a manner of speaking, the sound dampening housing to turn a distance out of the way of the drill rod.
When necessary, the inside of the housing 7 may be provided with separate support members attached to the sound dampening housing 7, such as supporting arches 18 and supporting bars 19 in the longitudinal direction of the sound dampening housing, to stiffen the sound dampening housing 7. The material of the arches 18 and the bars 19 may be solid, but preferably they are hollow tubular or open profiles, such as U, I, and L profiles. The arches and bars may be structures fixedly integrated with one another or separate parts attached to one another. It is, of course, obvious that the support members of the cover part 7a constitute a unity of their own while the support members of the rest of the sound dampening housing, i.e. the portion attached to the feed beam 6, constitute a unity of their own. Further, the inside of the sound dampening housing 7 may be provided with a dampening plate 20 made of a separate dampening material, which at least partly covers the inner surface of the sound dampening housing 7. Such a plate may be e.g. a perforated plate made of metal or another material, attached, for instance resting on supporting arches 18 and supporting bars, to a side opposite the sound dampening housing 7. The dampening plate may be completely or only partly perforated or even unperforated, as necessary. The dampening plate 20 may also be used without support members, in which case it is naturally attached to the sound dampening housing 7 directly so as to rest on separate support sleeves or the like and/or to the ribs facing the inside of the inner shell 13a.
In the above description and drawings, the invention has been described only by way of example, and it is by no means restricted thereto. The point is that the sound dampening housing, together with its parts, is formed from two shells located at a distance from one another such that a space is provided therebetween for air or gas.
Number | Date | Country | Kind |
---|---|---|---|
20075230 | Apr 2007 | FI | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/FI2008/050165 | 4/4/2008 | WO | 00 | 10/2/2009 |