EP3735514B1

EP3735514B1 - Device at tunnel boring machine arranged for drilling operations without operators in the borehole

Info

Publication number: EP3735514B1
Application number: EP18898967.7A
Authority: EP
Inventors: Per Olav Haughom
Original assignee: Norhard Asset AS
Current assignee: Norhard Asset AS
Priority date: 2018-01-02
Filing date: 2018-12-18
Publication date: 2023-02-15
Anticipated expiration: 2038-12-18
Also published as: EP3735514A1; NO20181428A1; EP3735514A4

Description

This invention concerns a tunnel-boring machine which is designed and adapted for carrying out directional-boring operations over long stretches, typically 2-3 km, without operators in the borehole. More particularly, it relates to a tunnel-boring machine comprising a frame, a rotating boring head with rolling disc cutters supported at a front end of a first frame portion, and a second, polygonal frame portion that extends rearwards from the first frame portion.
Today's technology for boring holes through rock formations may, in the main, be divided into two main categories:

Machines that bore with diameters up to about 1.5 m and are generally operated from a control unit out in the open.
When the diameter of the borehole is from about 1.5 m and upwards, the machines are operated with operators in the borehole. A machine operator is positioned in an operator cabin connected to the machine itself and controls the machine functions.

With today's requirements for safety and HSE, there will be extensive safety measures to meet rules and regulations. An extensive system with ventilation and safe escape routes is expensive, especially for long boreholes. When the machines are arranged for only minor maintenance works inside the borehole, the machines must be transported out for any major repairs. This is demanding and expensive operations, especially in long boreholes.
Directional control of today's unmanned tunnel-boring machines has limitations when the turning radius of the borehole prevents a line of sight from the outside in to the tunnel-boring machine.
Mass that is broken loose from the boring operation must be transported out by conveyor belts or rail cars. All this requires operators in the borehole for operating and maintaining the equipment.
Today's market asks for cost-effective machine solutions with no operators inside the borehole during the boring operations.
From AU708331 B2 , a boring machine for boring tunnels of a non-circular cross section is known, the boring machine being provided with two main cutters that each form semi-circular side portions of the borehole, whereas upper and lower elongated trimming cutters take out a straight ceiling portion and a straight floor portion which connect the two semi-circular side portions. The cutters are supported in a front unit which is connected to a rear unit via jacks that provide feeding of the cutters as they work into the material that is to be removed. The rear unit has a sectioned frame, wherein a straight main section may rest on the floor of the tunnel, semi-circular side sections may be clamped against the side walls of the tunnel by means of actuators moving the side sections sideways relative to the main section, and a straight top section may be clamped against the ceiling of the tunnel by means of actuators moving the top section sideways relative to the main section.
WO2008010189 A2 discloses a mining robot provided with a propulsion system including drive rollers arranged at end portions of two pairs of telescopic legs supporting a robot body on a surface under, possibly under and over, the robot as the legs are pivotable into different positions relative to the robot body. The drive rollers provide for the robot to be able to move in a passage that is defined by said surfaces.
From US2012032494 A1 , a boring machine provided with a boom carrying a cutter head via a rotary joint is known. A frame is provided with a driving apparatus which, via tracks, can provide for movement of the boring machine, and the frame is provided with several devices for anchoring the boring machine to surrounding surfaces during a boring operation. The cutter head is pressed against the material that is to be removed, by the boom being moved in its longitudinal direction relative to the clamped frame.
US 3,485,309 discloses an earth boring apparatus comprising an anchor tube assembly selectively anchored at its forward end within a pilot bore at a point within the rock or other material to be cut ahead of a rotating main cutter head that is axially slidable along the anchor tube assembly and the rotating cutter head is pulled forwardly into the material face toward the anchored front end of the anchor tube assembly. The anchor tube assembly near its read end carries rib jacks engaging the tunnel wall. Thrust reaction forces caused by the main cutting head action are transmitted directly to the rib packs by a system including levers pivoted on the anchor tube assembly connected by thrust links to the rib jacks and mounting thrust cylinders connected for urging the cutting head forwardly along the anchor tube assembly.
The present invention has for its object to remedy, or at least reduce, one or more of the drawbacks of the prior art.
The object is achieved according to the invention through the features that are specified in the description that follows and in the claims.
The invention provides a tunnel-boring machine arranged to bore circular holes through a rock formation, the tunnel-boring machine comprising a boring head (drill bit) rotating around the longitudinal axis of the borehole and being provided with rolling disc cutters or rolling discs which, by rotation of the boring head, break material loose when subjected to compressive forces against the rock. The rotation of the boring head is provided by a driving apparatus, typically in the form of one or more electromotors with step-down gearing between the motor(s) and the boring head.
To provide the necessary push force (feeding force) axially on boring head, an anchoring unit is arranged, which is axially movable on a portion of a frame in the tunnel-boring machine and is provided with a set of radially displaceable anchoring feet that can be clamped against a surrounding borehole wall and constitute the anchoring attachments for one or more feeding cylinders that are attached to the anchoring unit and the frame, so that the tunnel-boring machine may be pushed in its longitudinal direction and apply a desired feeding force to the boring head.
To control the direction of the borehole, the frame is provided with a set of supporting rollers near the boring head. The supporting rollers rest against the borehole wall and provides for the boring head to be stabilized sideways. The anchoring unit is placed behind the supporting rollers and is so arranged that each anchoring foot can be adjusted individually. Thereby the direction of the boring machine can be given an angular change by pivoting about one or more of the supporting rollers, so that the direction of boring and thereby the direction of the borehole is changed. The data used for setting the desired directional change may come from a directional-control unit placed at some distance behind the tunnel-boring machine.
Cuttings that is broken loose by the boring head may be transported away from the boring head by, for example, water flushing and a mechanical transport device suitable for the purpose. The mixture of cuttings and water may be carried into a pumping unit by means of said transport device.
From the pumping unit, the mixture of water and cuttings is carried through pipes or hoses to a collecting point outside the borehole.
To be able to move the tunnel-boring machine into and out of the borehole, a transport device (tractor) is arranged in association with the tunnel-boring machine, which makes it possible, by means of electrically or hydraulically driven wheels or track sections, to move the boring machine in the borehole. The wheels or track sections are arranged on radially movable structures which can push the wheels or track sections against the borehole wall to achieve sufficient friction.
To prevent the tunnel-boring machine from rotating around the longitudinal axis of the borehole while being moved, it is an advantage if at least one of the driving wheels or one of the track sections is supported in joints so that, by means of a hydraulic cylinder, said wheel or track section can be given a directional change relative to the longitudinal axis of the borehole.
Outside the borehole are placed a control unit, typically arranged in an operator cabin, and necessary equipment for power supply and for handling cables, hoses and pipes, typically arranged on drums.
The invention is defined by the independent claim. The dependent claims define advantageous embodiments of the invention.
The invention relates, more specifically, to a tunnel-boring machine comprising a frame, a rotating boring head with rolling disc cutters supported at a front end of a first frame portion, and a second, polygonal frame portion extending rearwards from the first frame portion, characterized by an anchoring unit, which is provided with several radially movable anchoring feet, being rotationally rigidly arranged on the second frame portion and being arranged to be displaceable in a longitudinal direction of a longitudinal axis of the tunnel-boring machine by means of at least one hydraulic feeding cylinder; a transport device, which is arranged to move the tunnel-boring machine in a borehole, being connected to the frame; and the transport device comprising several wheel sets, each wheel set including at least one wheel that is connected to a driving motor, the wheel sets being supported in bogies which are pivotally connected to telescopic structures which are radially displaceable by means of hydraulic cylinders, and the first frame portion is provided with several supporting rollers which, by abutment against a surrounding borehole wall, form a pivot point in a change of direction by the tunnel-boring machine by individual radial displacement of the anchoring feet.
A transport device may be in association with a pumping unit and be arranged to feed cuttings into the pumping unit.
The wheel sets may form part of a drive-track arrangement.
At least one of the wheel sets may include a steered wheel arranged in a wheel attachment which is pivotable around a king pin by means of a third cylinder.
The boring operation may be controllable from an operator cabin outside the borehole.
In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings, in which:

Figure 1: shows a side view of a tunnel-boring machine placed inside a borehole in a rock formation that is shown in section;
Figure 2: shows, on a larger scale, a perspective drawing of a tunnel-boring machine with a boring head and an anchoring unit;
Figure 3: shows, on a larger scale, anchoring feet in a section of the tunnel-boring machine;
Figure 4: shows, on a smaller scale, a perspective drawing of the tunnel-boring machine with a boring head, an anchoring unit, a tractor and a pumping unit arranged in a borehole that is shown in an axial section;
Figure 5: shows, on a larger scale, a perspective drawing of the anchoring feet with displacing devices;
Figure 6: shows a perspective drawing of a transport device (tractor) connected to the tunnel-boring machine;
Figure 7: shows a perspective drawing of the transport device provided with wheels;
Figure 8: shows the transport device in a side view;
Figure 9: shows a side view of the transport device with steered-wheel support;
Figure 10: shows a cross section X-X according to figure 8 through the transport device;
Figure 11: shows, on a smaller scale, a principle drawing of the directional control of the tunnel-boring machine; and
Figure 12: shows an end view seen in the direction A-A according to figure 11 of the anchoring feet in the activated position.

Reference is first made to figures 1 to 5. A borehole 2 is bored through a rock formation 1 by means of a tunnel-boring machine 3 which is provided with a boring head 4 with rolling disc cutters 5. The tunnel-boring machine 3 is further provided with a frame 6 comprising a first frame portion 6a, shown here as a portion with a circular cross section, and a second frame portion 6b shown here as a portion with a substantially quadrangular cross section.
In the first frame portion 6a, a driving apparatus (not shown) for rotating the boring head 4 projecting from an end of the first frame portion 6a is installed. The first frame portion 6a is provided with supporting rollers 9 arranged near the boring head 4. The supporting rollers 9 are arranged to rest against a borehole wall 2a formed by the boring head 4, in order thereby to position the boring head 4 radially.
Axial feeding force on the boring head 4 is provided by an anchoring unit 7 which is rotationally rigidly displaceable on the second frame portion 6b. The anchoring unit 7 is provided with several anchoring feet 11, shown here as four anchoring feet 11, which can be pressed against the borehole wall 2a by means of first hydraulic cylinders 16 in order thereby to form an anchoring for a feeding cylinder 10 connected to the anchoring unit 7 and the frame 6, typically the first frame portion 6a, and arranged to push the frame 6 relative to the anchoring unit 7 and thereby relative to the surrounding borehole wall 2a to which the anchoring unit 7 is clamped. The second frame portion 6b provides a travelling path for the anchoring unit 7 with a length adapted to a preferred length of stroke of the feeding sequence, that is to say the length of stroke of the feeding cylinder 10. The second frame portion is provided with sliding rails 8 against which the anchoring unit 7 is resting supportingly. By the anchoring unit 7 being arranged in a rotationally rigid manner on the polygonal second frame portion, a torque from the boring head 4 may be transmitted to the borehole wall 2a via the anchoring unit 7.
The radial displacement of the anchoring feet 11 relative to the frame 6, 6b is provided by means of first and second links 13, 14 connected to the anchoring feet 11 and to a sliding structure 15 via first and second link joints 17, 18 and connected to first hydraulic cylinders 16 by third link joints 19. The first hydraulic cylinders 16 displace the anchoring feet 11 radially by a displacement of the third link joints 19 relative to the sliding structure 15 in the longitudinal direction of the second frame portion 6b.
Reference is now made to figures 1, 4 and 6-10. The tunnel-boring machine 3 may be transported in and out through the borehole 2 with a transport device (tractor) 20 placed behind the actual boring machine 3, where it is connected to the second frame portion 6b. A number of wheels 21 form several wheel sets 21a, which are possibly provided with tracks (not shown), and are arranged on bogies 22 which, via bolt connections 23, are articulately supported in telescopic structures 24 that are radially displaceable by means of second hydraulic cylinders 25. The telescopic structures 24 are, in turn, connected to a frame structure 26 (see figures 6 and 7). The wheels 21 are driven by electric or hydraulic motors 27.
Reference is now made to figure 9. One of the wheels 28 may be attached to a wheel attachment 31 as a steered wheel pivotably supported on a king pin 29 so that the wheel 28 may be given an angle 32 relative to a longitudinal axis 33 of the tractor. Thereby the direction of motion of the tunnel-boring machine 3 can be controlled during transport in and out. A third hydraulic cylinder 30 controls the direction of the steered wheel 28.
Reference is again made to figures 1 and 4. The out-transport of cuttings may be carried out with a pumping unit 34 connected to the tunnel-boring machine 3, placed behind the transport device 20 here and with a transport device 35, for example a conveyor belt carrying cuttings from the boring head 4 up into the pumping unit 34. From the pumping unit 34 a mixture of cuttings and added water is pumped out through pipes or hoses 36.
Power and control cables run from cable drums 37 outside the borehole 2 in to the tunnel-boring machine 3 inside the borehole 2.
A cabin 38 for manned operation of the boring operation is placed outside the borehole 2.
Reference is now made to figures 11 and 12. The direction of the borehole 2 is controlled by the longitudinal axis 33 of the tunnel-boring machine 3 being given an angular displacement around a pivot point 41 formed by one or more of the supporting rollers 9 arranged on the frame 6 near the boring head 4 so that an axis 39 forms an angle 40 with the centre axis of the borehole 2, represented by the earlier position of the longitudinal axis 33 of the tunnel-boring machine 3. The angular displacement is provided by the anchoring feet 11 being set by individual radial movements 42 (see figure 12) in two planes by means of the first hydraulic cylinders 16.
It should be noted that all the above-mentioned embodiments illustrate the invention, but do not limit it, and persons skilled in the art may construct many alternative embodiments without departing from the scope of the attached claims. In the claims, reference numbers in brackets are not to be regarded as restrictive.
The use of the verb "to comprise" and its different forms does not exclude the presence of elements or steps that are not mentioned in the claims. The indefinite article "a" or "an" before an element does not exclude the presence of several such elements.
The fact that some features are indicated in mutually different dependent claims does not indicate that a combination of these features cannot be used with advantage.

Claims

A tunnel-boring machine (3) comprising
a frame (6)

a rotating boring head (4) with rolling disc cutters (5) supported at a front end of a first frame portion (6a), and

a second, polygonal frame portion (6b) extending rearwards from the first frame portion (6a),

an anchoring unit (7) which is provided with several radially displaceable anchoring feet (11) is arranged in a rotationally rigid manner on the second frame portion (6b) and is arranged to be displaceable in a longitudinal direction of a longitudinal axis (33) of the tunnel-boring machine (3) by means of at least one hydraulic feeding cylinder (10);

a transport device (20), which is arranged to move the tunnel-boring machine (3) in a borehole (2), is connected to the frame (6);

the transport device (20) comprises several wheel sets (21a), each wheel set (21a) including at least one wheel (21) that is connected to a driving motor (27), and the wheel sets (21a) are supported in bogies (23) which are pivotably connected to telescopic structures (24) which are radially displaceable by means of hydraulic cylinders (25); and characterized in that the first frame portion (6a) is provided with several supporting rollers (9) which, by abutment against a surrounding borehole wall, form a pivotpoint (41) for a directional change (40) of the tunnel-boring machine (3) by individual radial displacement of the anchoring feet (11).
The tunnel-boring machine (3) according to claim 1, wherein a transport device (35) is connected to a pumping unit (34) and is arranged to feed cuttings into the pumping unit (34).
The tunnel-boring machine (3) according to claim 1, wherein the wheel sets (21a) form part of a drive-track arrangement.
The tunnel-boring machine (3) according to claim 1, wherein at least one of the wheel sets (21a) comprises a steered wheel (28) arranged in a wheel attachment (31) which is pivotable around a king pin (29) by means of a third cylinder (30).
The tunnel-boring machine (3) according to claim 1, wherein the boring operation is controllable from an operator cabin (38) outside the borehole (2).