EXPANSION DRILLING JIG

Description

[0001] The invention relates to an expansion drilling device for expanding a pilot borehole created from a starting point to a target point in the ground along a predetermined drilling line, preferably close to the surface, by moving the expansion drilling device along the predetermined drilling line to create a borehole in the ground or in rock for inserting a pipeline or a support structure into the expanded borehole: with a housing; with a drilling side and with a rear side opposite the drilling side; with a drill head having a cutting wheel that is mounted and driven about an axis of rotation and relative to the housing on the drilling side of the expansion drilling device, on which cutting wheel at least one drilling tool for loosening the ground or rock is arranged; with a drilling-side connection for establishing a connection to a pipe string located in the pilot borehole, preferably a pilot drill string,on the drilling side; with a rear connection for the pipeline to be inserted at the rear of the drill head, wherein the drilling side is provided centrally with at least one receiving space for the loosened soil or rock, which is connected via at least one discharge opening to a material conveying device of the reaming drilling device for the loosened soil or rock, wherein the drilling side has at least one receiving space for the loosened soil or rock, which is connected via at least one discharge opening to a material conveying device of the reaming drilling device for the loosened soil or rock, wherein the drilling side has at least one drilling space in which the cutting wheel is arranged, which is arranged around the receiving space, wherein the cutting wheel is annular and is arranged so as to be rotatable around the central receiving space,and wherein the receiving space is connected to the drilling space via at least one conveying opening, so that the loosened soil or rock can be conveyed through the opening into the receiving space.

[0002] For the near-surface installation of underground cables, the open trench method is used. This sometimes leads to significant environmental impacts along the route and involves considerable effort for excavation and backfilling.

[0003] To minimize environmental impacts during the construction phase and minimize construction costs, it is necessary to achieve long trenchless lengths. Trenchless lengths of up to 1,500 m are desirable. A problem with near-surface installation is the limited cover depth of the pipeline (e.g., only 2 to 6 m).

[0004] This is particularly problematic if, for example, the site conditions make it impossible to drill a hole and then directly insert a pipeline into it. In this case, widening the hole may be necessary.

[0005] Such a laying would be conceivable with the Horizontal Directional Drilling (HDD) method in terms of the requirements for diameter and length. With this method, a pilot bore is first created using a rotating drill bit and drill rod from the starting point towards the target point. Positioning accuracy is ensured by a surveying system installed behind the drill bit. The excavated material is brought to the surface with a bentonite slurry. The bentonite slurry is pumped through the drill rod directly to the nozzles attached to the drill bit. The slurry mixes with the loosened soil and flows back to the starting point through the annular space between the drill rod and the ground. After the pilot drilling is completed, the drill bit is replaced with a reamer, which then reams the pilot bore while the pipeline is pulled in.Such a method is known from EP0360321A1.

[0006] However, high mud pressures are required for clean removal of the loosened soil using the HDD method. To prevent unwanted mud leakage at the surface, the HDD method requires the greatest possible installation depths, resulting in overburden of more than 30 m, for example. Installation depths of less than 10 m can lead to unwanted mud leakage with the conventional HDD method under certain soil conditions.

[0007] A previously described drill head is known from DE2701066A1. This is used to expand a pilot bore during pipe jacking. DE2701066A1 discloses a method and a device for laying pipes underground. This involves using a discharge head with which a pilot bore is expanded and to which the pipeline to be installed is attached. A screw conveyor is provided in the pilot pipe string, which conveys away the soil loosened by the blades of the rotating discharge head. The loosened soil enters the conveying chamber of the screw conveyor through openings. With the disclosed method and the disclosed device, in particular the necessary near-surface laying lengths cannot be achieved, especially with relatively small pipeline diameters. Furthermore, the possibleThe soil, which is heavily mixed in the near-surface area, cannot be safely mined and removed using the disclosed method and device.

[0008] The object of the invention is to provide an expansion drilling device with which a near-surface expansion of a pilot bore is possible even in highly heterogeneous soils.

[0009] This object is achieved in that at least one crusher is provided in the drilling chamber, and in that the crusher has crusher bars on the rotatable cutting wheel, which move together with the cutting wheel and has crusher bars on a side of the receiving chamber facing the drilling chamber, which are rigidly arranged together with the receiving chamber, and in that the crusher bars are arranged relative to one another in such a way that a crushing gap exists between the crusher bars.

[0010] The advantage here is that the reaming drilling device can be used close to the surface and can expand a near-surface pilot bore and simultaneously insert a pipe into the expanded borehole, for example a pipe for the construction of a pipeline or a district heating line, or even a protective pipe for laying power lines or the like. The central receiving space enables easy removal through the pipe string located in the pilot bore, thus minimizing the risk of blowouts as in the HDD process. The provision of the crusher ensures that the loosened soil or rock is in a recoverable grain size. Furthermore, this simple crusher design has proven surprisingly effective.

[0011] A further teaching of the invention provides that the receiving space is a hollow cylinder whose end faces are closed. It is also advantageous that the receiving space is a suction box. It is also advantageous that the at least one discharge opening of the receiving space is arranged on an end face of the hollow cylinder. A suction nozzle is preferably provided on the discharge opening. This allows the loosened soil / rock to be removed safely and easily. Furthermore, it has surprisingly been found that by providing the receiving space as a central hollow cylinder, the receiving space can be designed to be particularly small and stable. Furthermore, suction from the hollow cylinder is possible efficiently.

[0012] It is further advantageous that the at least one conveying opening is located on the outer surface of the hollow cylinder, preferably at the top. This allows the loosened soil or rock to be introduced into the receiving chamber in a particularly simple and efficient manner. Suction into the receiving chamber through the receiving opening is possible for additional support. It is advantageous that the cutting wheel is provided with drivers that move the loosened soil or rock toward the conveying opening.

[0013] A further teaching of the invention provides that the receiving space is rigidly connected to the housing. This allows for a simple transmission of the forces required for expansion and retraction.

[0014] A further teaching of the invention provides that the drill-side connection is rigidly connected to the housing or the receiving space. This allows for a simple transmission of the necessary forces for expansion and retraction.

[0015] A further teaching of the invention provides that the at least one conveying opening is a classifying element or that a classifying element is arranged in the at least one conveying opening. This simply ensures that the loosened soil or rock reaches the receiving chamber only in a particle size suitable for removal.

[0016] A further teaching of the invention provides that the material conveying device of the reaming drilling device has at least one conveying pump, the suction side of which is connected to the discharge opening. This allows the loosened soil or rock to be easily conveyed through the pilot drill string. It is advantageous for the at least one conveying pump to be a jet pump. A jet pump enables simple, efficient suction from the discharge chamber. Furthermore, the jet pump makes it possible to convey the loosened soil / rock over lengths of 2000 m and more with small borehole diameters without additional pumps in the pipe string.

[0017] A further teaching of the invention provides that the rear connection for the pipeline to be introduced into the widened bore is rigidly connected to the housing or to the receiving space.

[0018] It is advantageous that the rear connection has a rotatable section which enables relative rotation between the housing of the reaming drilling device and the pipeline to be inserted, preferably a hydraulic cylinder.

[0019] It is further advantageous that the rear connection has a measuring element for measuring the pulling force acting on the pipe to be inserted, preferably a hydraulic cylinder

[0020] A further teaching of the invention provides that the housing has at least a first section, which has a first diameter that is smaller than an inner diameter of the annular cutting wheel and preferably substantially corresponds to the outer diameter of the tubing string located in the pilot borehole, and a second section that is substantially slightly smaller than the inner diameter of the expanded borehole. This allows for a simple separation of the arrangement of the necessary technology for extraction and the necessary technology for drilling.

[0021] A further teaching of the invention provides that at least one discharge opening is provided on the rear side for discharging a bentonite suspension into the annular space of the expanded bore.

[0022] The invention is explained in more detail below using an exemplary embodiment in conjunction with a drawing. The drawings show: Fig. 1 a schematic representation of a first embodiment of the invention, Fig. 2 a schematic representation of a first embodiment of the invention, Fig. 3 a schematic representation of a sectional view of an expansion drill head according to the invention, Fig. 4 a schematic representation of a plan view of an expansion drill head according to the invention Fig. 3 , Fig. 5 a schematic representation of a top view of a cutting wheel according to the invention Fig. 3 , and Fig. 6 a schematic representation of a top view of a receiving space according to the invention Fig. 3 .

[0023] Figure 1shows a first embodiment of an expansion drilling device 10 according to the invention. This device has a housing 11 that is divided into a front section 12 and a rear section 13. The front section 13 has a first diameter that is identical to the diameter of the pipes in the pilot borehole (not shown).

[0024] The rear portion 13 has a second diameter which is slightly smaller than the diameter of a drill head 14 arranged on a drill side 21 of the housing 11.

[0025] Figure 2shows a second embodiment of an expansion drilling device 10 according to the invention. This device comprises a housing 11 that has only the rear section 13. The front section 13 has a first diameter that is identical to the diameter of the pipelines in the pilot borehole (not shown). The rear section 13 here has a diameter that is slightly smaller than the diameter of a drill head 14 arranged on a drilling side 21 of the housing 11.

[0026] The drill head 14 has a cutting wheel that, as shown in the Fig. 3 to 6 is shown, is preferably designed as a cutting ring 15. Drilling tools 16, for example disk chisels, paring knives, drill bits or the like, are attached to the cutting ring 15.

[0027] The cutting ring 15 is driven by hydraulic motors 17. A hydraulic pump 18, driven, for example, by an electric motor 19, is provided to drive the hydraulic motors 17. A tank 20 is also provided for the hydraulic fluid with which the hydraulic pump 18 drives the hydraulic motors 17.

[0028] The drill head 14 is arranged in the drilling side 21. The housing 11 further has a rear side 22, on which a rear stop 23 is arranged for connection to a pipeline (not shown) to be inserted into the borehole. This can be, for example, a swivel with tensile force measurement, preferably designed as a hydraulic cylinder.

[0029] The cutting ring 15 is connected to a receiving chamber for receiving the loosened soil or rock, which is preferably designed as a suction box 24. A feed pump is provided for removing the loosened soil or rock, which is preferably designed as a jet pump 25.

[0030] The jet pump 25 can, as in Figure 1 shown, be arranged in the front section 12 of the housing 11. Alternatively, as also shown in Figure 2As shown, the feed pump can also be provided in the rear section 13 of the housing 11. The jet pump 25 has a drive line 26, which is acted upon by a high-pressure pump (not shown). Furthermore, the jet pump 25 has a discharge line 27, via which the liquid supplied via the drive line 26 is discharged together with the mixture of liquid and loosened soil / rock sucked out of the suction box 24 via a suction line 28. The suction line 28 is connected to a suction nozzle 29, which is connected to at least one discharge opening 30 of the suction box 24.

[0031] Furthermore, a feed line 31 is guided through the front section 12, which supplies the drill head 14 with liquid to support the working face and to remove the loosened soil / rock in the area of the cutting wheel / cutting ring 15.

[0032] Furthermore, a lubricating fluid line 32 is provided, which leads to the rear side 22 of the housing 11. There, a lubricant is discharged through an opening 33 into the annular space (not shown), which serves to support the borehole and reduce friction between the outside of the pipeline to be installed (not shown) and the borehole wall (not shown).

[0033] A front stop 34 is, as in Figure 1 and Figure 2 is shown, connected to the suction box 24. This preferably has a connection option with the front section 12. Particularly preferably, the connection between the stop 34 and the front section 12 is designed to provide angular mobility so that the reaming drilling device 10 can better follow the direction of the pilot borehole.

[0034] In Figure 2The stop 34 serves to connect to the pipeline in the pilot borehole. This connection option is also preferably designed to allow angular mobility so that the reaming drilling device 10 can better follow the direction of the pilot borehole.

[0035] In Figure 1 At the front end 35 of the front section 12 of the housing 11, a connecting element 36 is provided with the pilot drill string located in the borehole.

[0036] Preferably, the connecting element 36 is identical to the connecting element of the stop 34.

[0037] The connecting elements 36 are preferably male or female connecting elements of a tensile-resistant push-in socket connection. This has circumferential grooves in the contact surfaces of the male and female connecting elements, forming a spiral channel with at least one outwardly directed connection opening for inserting a shear element, for example, a chain, to establish a longitudinal force-locking connection.

[0038] After connecting the reaming drilling device 10 to the pipe string located in the pilot borehole and connecting the lines 26, 27, 31, 32, a valve 37 in the suction line 28 is closed, and the jet pump 25 is started. The reaming drilling device 10 is then pulled into the ground / rock by retracting the pilot drill string, for example, using a press frame (not shown), to ream the pilot borehole. During this process, the cutting ring 15 of the drill head 14 rotates. The drilling tools 16 loosen the ground / rock, thereby preferably enlarging the pilot borehole to its final size. Multiple reaming passes are also possible before the final pipe is pulled in.

[0039] As soon as the soil / rock is loosened, the valve 37 is opened and the liquid-soil / rock mixture is sucked from the suction box 24 through the discharge opening 30, the suction nozzle 29 and the suction line 28.

[0040] The cutting ring 15 is in a bore chamber 38 (see Figure 3 to 6 ). The cutting ring 15 has at least one saddle 39 on which drilling tools 16 are arranged. For example, paring knives or drill bits 40 are arranged on the saddles.

[0041] The saddles 39 are preferably provided in a uniformly circumferentially distributed manner on the cutting ring 15.

[0042] The saddles 39 are preferably designed to carry loosened soil / rock. For this purpose, for example, carriers 42 are provided on the saddles 39.

[0043] The saddles 39 / the carriers 42 transport loosened soil / loose rock to conveying openings 41. Through these, the loosened soil / loose rock can reach or be sucked into the receiving space / suction box 24.

[0044] The conveying openings 41 are or contain classifying elements which ensure that only conveyable grain sizes reach the suction box 24.

[0045] Furthermore, the cutting ring 15 preferably has nozzles 43 through which feed fluid, preferably bentonite suspension, is discharged into the bore chamber 38. This serves to fill the bore chamber 387 with fluid to support the working face and to enable the transport of the loosened soil / rock in the bore chamber 38.

[0046] The receiving chamber 24 is preferably designed as a hollow cylinder. The hollow cylinder has an outer wall 44 in which the conveying openings 41 are provided, preferably in the upper section. Furthermore, the end faces 45 of the hollow cylinder are closed to provide the suction box 24.

[0047] Additionally, a crusher 46 is provided in the drilling chamber 38. For this purpose, crusher bars 47 are provided on the rigid outer wall 44 of the receiving chamber 24. These crusher bars are rigidly arranged in the drilling chamber 38. The saddles 39 have a receiving surface 48 facing the rigid crusher bars 47, on which crusher bars 49 are provided. Between the rigid crusher bars 47 and the crusher bars 49, which rotate with the cutting ring 15, for example, in the direction of arrow A, a crusher gap 50 exists when these are radially superimposed, which determines the grain size of the material to be extracted.

Claims

1. Expanding drill device for expanding a pilot bore created from a starting point to a target point in the ground along a specified drilling line by moving the expanding drill device (10) along the specified drilling line in order to create a bore in the ground or in rock for introducing a pipeline or a supporting system into the expanded bore: having a housing (11); having a drill side (21) and having a rear side (22) opposite the drill side (21); having a drill head (14) that has a cutting wheel (15), which is arranged on the drill side (21) of the expanding drill device (10) so as to be mounted and driven rotatably about a rotational axis and relative to the housing and on which at least one drill tool (16) for loosening the ground or the rock is arranged; having a drill-side connection for producing a connection to a pipe section located in the pilot bore on the drill side; having a rear-side connection for the pipeline to be introduced on the rear side of the drill head; wherein the drill side (21) centrally has at least one receiving chamber (24) for the loosened ground or the loosened rock, said receiving chamber being connected via at least one removal opening (30) to a material-conveying device of the expanding drill device (10) for the loosened ground or the loosened rock, wherein the drill side (21) has at least one drill chamber (38) in which the cutting wheel (15) is arranged, which is arranged around the receiving chamber (24), wherein the cutting wheel (15) is annular and is arranged rotatably about the central receiving chamber (24), and wherein the receiving chamber (24) is connected via at least one conveying opening (41) to the drill chamber (38) so that the loosened ground or the loosened rock can be conveyed through the conveying opening (41) into the receiving chamber (24), characterized in that at least one crusher (46) is provided in the drill chamber (38), that the crusher (46) has crusher bars (49) on the rotatable cutting wheel (15), which move together with the cutting wheel (15), and crusher bars (47) on a side of the receiving chamber (24) facing the drill chamber (38), which are fixedly arranged together with the receiving chamber (24), and that the crusher bars (47, 49) are arranged relative to one another such that a crusher gap (50) exists between the crusher bars.

2. Expanding drill device according to Claim 1, characterized in that the receiving chamber (24) is a hollow cylinder, the end faces (45) of which are closed.

3. Expanding drill device according to Claim 2, characterized in that the at least one removal opening (30) of the receiving chamber (24) is arranged on an end face (45) of the hollow cylinder.

4. Expanding drill device according to Claim 2 or 3, characterized in that the at least one conveying opening (41) is arranged on the outer lateral surface of the hollow cylinder.

5. Expanding drill device according to Claim 4, characterized in that the conveying opening (41) is arranged at the top.

6. Expanding drill device according to one of Claims 1 to 5, characterized in that the receiving chamber (24) is connected rigidly to the housing.

7. Expanding drill device according to one of Claims 1 to 6, characterized in that the drill-side connection is connected rigidly to the housing (11) or to the receiving chamber (24).

8. Expanding drill device according to one of Claims 1 to 7, characterized in that the at least one conveying opening (41) is a screening element, or that a screening element is arranged in the at least one conveying opening (41).

9. Expanding drill device according to one of Claims 1 to 8, characterized in that the material-conveying device of the expanding drill device (10) has at least one conveying pump, the suction side of which is connected to the removal opening.

10. Expanding drill device according to Claim 9, characterized in that the at least one conveying pump is a jet pump (25).

11. Expanding drill device according to one of Claims 1 to 10, characterized in that the rear-side connection for one pipeline that is to be introduced into the expanded bore is connected rigidly to the housing (11) or to the receiving chamber (24).

12. Expanding drill device according to Claim 11, characterized in that the rear-side connection has a rotatable portion, which allows a relative rotation between the housing (11) of the expanding drill device (10) and the pipeline to be introduced.

13. Expanding drill device according to Claim 11 or 12, characterized in that the rear-side connection has a measuring element for measuring the drawing-in force acting on the pipeline to be introduced.

14. Expanding drill device according to Claim 12 or 13, characterized in that the rotatable portion and / or the measuring element is / are a hydraulic cylinder.

15. Expanding drill device according to one of Claims 1 to 14, characterized in that at least one discharge opening for discharging a bentonite suspension into the annular space of the expanded bore is provided on the rear side.