Patent Application
20120051843
The invention, in general, relates to tunnel drilling machines. More specifically, the invention relates to a tunnel drilling machine which drills an epitrochoidal tunnel.
Tunnel drilling machines have long been used to drill underground tunnels through rocks and soil. Typically, tunnel drilling machines have a circular drilling face which drills a circular tunnel. These tunnels are used to lay automotive or train passes to provide means of public transport. However, a circular tunnel may not be convenient for constructing automotive or train passes as these passes usually require additional spaces on either side of the tunnel to allow for cabling, lighting, maintenance, etc. Also, when multiple automotive or train passes are laid alongside each other, a circular tunnel may have to be drilled for each of the multiple automotive or train passes. Drilling multiple circular tunnels alongside each other may raise structural safety concerns and may also not be economically feasible.
Thus, there is a need for a tunnel drilling machine for drilling an epitrochoidal tunnel wherein, two maximum extension points at the sides of the tunnel and two contraction points at the top and bottom of the tunnel are formed.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the invention.
Before describing in detail embodiments that are in accordance with the invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a method and tunnel drilling machine for drilling an epitrochoidal tunnel. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
Generally speaking, pursuant to various embodiments, the invention provides a tunnel drilling machine and a method of drilling an epitrochoidal tunnel using the tunnel drilling machine. The tunnel drilling machine includes a tunneling machine body; a fixed gear operatively coupled to a frontal end of the tunneling machine body along a central axis of the tunneling machine body, and a drill head having a substantially triangular periphery and including an internal gear ring. The internal gear ring is mounted on the fixed gear, wherein the fixed gear drives the internal gear ring around the fixed gear with a gear ratio of 3:1. Here, driving the drill head with a gear ratio of 3:1 allows the tunnel drilling machine to drill an epitrochoidal tunnel through rocks and soil.
In addition to enabling tunnel drilling machine 100 to drill in an angularly upward or downward direction, wheels 106 may be individually extended sideways to cause tunnel drilling machine 100 to move in one of a left direction or right direction. For example, tunnel drilling machine 100 may be caused to move right by extending one or more of lower left rear wheel 106-1 and upper left rear wheel 106-3.
It will be apparent to a person skilled in the art that movement of tunnel drilling machine 100 includes but is not limited to the above stated degrees of freedom. Alternate degrees of freedom may be achieved by independently extending wheels 106 in one of more directions.
Tunneling machine body 102 also includes one or more of a plurality of heating torches 108 and a plurality of nozzles (not shown in
Although the nozzles are not shown in
Tunnel drilling machine 100 further includes a drill head 104 having a substantially triangular periphery. Drill head 104 is operatively coupled to tunneling machine body 102 through an internal gear ring mounted on a fixed gear with a gear ratio of 3:1. Here, the fixed gear drives the drill head with a gear ratio of 3:1 to trace an epitrochoidal path. The mounting of the internal gear ring on the fixed gear is further elaborated in conjunction with
Drill head 104 having a substantially triangular periphery has a sloped front face and is one of a substantially pyramidal shape and a substantially conical shape. The sloped drill head allows for gradual drilling and also to provide strong attachment points to a plurality of helically arranged cutting tools 110, wherein cutting tools 110 are configured to crush the rocks. The helical arrangement of cutting tools 110 provides the thrust force needed to drive tunnel drilling machine 100 through the rocks. Additionally, drill head 104 may also include one or more openings through which cutting tools 110 are cooled or cleaned by passing a fluid at high pressure. The fluid at high pressure is forced through the one or more opening by selectively activating the nozzles.
In addition to cutting tools 110 and the one or more openings, drill head 104 further includes a plurality of relief cuts 112. Relief cuts 112, in an embodiment, may be shaped with a helix angle and may be cut along each side of the drill head having the substantially triangular periphery. Relief cuts 112 functions to move drill remains away from drill head 104 during rotation of drill head 104. Alternatively, the one or more nozzles may be activated to spray fluid at high pressure to remove loose rock or soil. Once one or more of relief cuts 112 and the nozzles cause the drill remains to move away from the drill head, one or more suction holes on tunneling machine body 102 draw the drill remains into tunneling machine body 102. The drill remains may subsequently be ejected from tunneling machine body 102 through an outlet at a distal end of tunneling machine body 102.
The coupling between fixed gear 202 and internal gear ring 204 is based on the Wankel rotary engine, wherein fixed gear 202 drives internal gear ring 204 with a gear ratio of 3:1. Since internal gear ring 204 is coupled to drill head 104, three rotations of fixed gear 202 causes one complete rotation of drill head 104. The substantially triangular periphery of drill head 104 in conjunction with the interaction between fixed gear 202 and drill head 104 enables drilling an epitrochoidal tunnel. Here, due to the 3:1 coupling, drill head 104 is associated with multiple axes of rotation and the rotation of drill head 104 along these multiple axes traces out an epitrochoid.
The epitrochoidal path traced by the drill head enables selectively activating one or more of heating torches 108 and the nozzles. For example, the exposed heating torches 302 illustrated in
In an embodiment, drill head 104 may include one or more vibration sensors. The vibration sensors determine a hardness of rocks surrounding drill head 104. In response to determining the hardness of rocks, one or more exposed heating torches 302 are selectively activated to heat the rocks. For example, a limited number of exposed heating torches 302 may be activated if the vibration sensors determine that the surrounding rocks are relatively soft, whereas a larger number of exposed torches 302 may be activated for heating harder rocks. Also, the intensity of heat produced by exposed heating torches 302 may be controlled depending on the hardness of the rocks. In a similar manner, one or more exposed nozzles may also be selectively activated based on the hardness of the surrounding rocks.
In response to heating the rocks, one or more nozzles are activated at step 404. The nozzles spray a fluid at high pressure at the rocks to quench the rocks. Quenching corresponds to the sudden cooling of the rocks. This sudden cooling of the heated rocks causes the rocks to crack, thereby allowing drill head 104 to drill through the rocks at step 406. Drilling is accomplished by rotation of drill head 104 around fixed gear 202. Fixed gear 202 drives drill head 104 with a gear ratio of 3:1 thereby allowing drilling of an epitrochoidal tunnel. Activation of cutting tools 110 further enables gradual drilling through the rocks.
On drilling through rocks and soil, drill remains are moved away from drill head 104 by one or more of one or more relief cuts 112 and a fluid at high pressure as described in conjunction with
Various embodiments of this disclosure provide a tunnel drilling machine and methods for drilling an epitrochoidal tunnel using the tunnel drilling machine. The tunnel drilling machine includes a fixed gear which drives a drill head through an epitrochoidal path thereby enabling drilling an epitrochoidal tunnel. Due to the drill head tracing an epitrochoidal path, one or more heating torches and nozzles included in the tunneling machine body may be selectively activated. The one or more heating torches or nozzles are selectively activated based on the rotation of the drill head through the epitrochoidal path. Additionally, the epitrochoidal shape allows support against counter torque when rotating the cutting tools. Also, the epitrochoidal shape allows for wheels of the tunnel drilling machine to advance, rotate and retract the drilling machine.
Those skilled in the art will realize that the above recognized advantages and other advantages described herein are merely exemplary and are not meant to be a complete rendering of all of the advantages of the various embodiments of this disclosure.
In the foregoing specification, specific embodiments of this disclosure have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of this disclosure as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of this disclosure. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. This disclosure is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.
