DK2505762T3 - Drilling device and method for horizontal drilling - Google Patents

Description

The invention relates to a drilling device for horizontal drilling having a drill head, a drill rod, at the borehole-sided end of which the drill head is arranged, and a drive means which is arranged at the other end of the drill rod and is designed for the rotational driving and feed driving of the drill rod, wherein the drill rod has an outer rod and an inner rod rotatably supported relative thereto, which are each composed of at least two drill rod elements, between which an annular space is designed for passing a flushing liquid from a rotary connection to the drill head, the inner rod comprises an alignment space, which extends from the drive means up to a terminal element on the drill head side, and in the alignment space at least a part of a target means for directional monitoring of the drill head is arranged, in accordance with the preamble of claim 1.

Furthermore, the invention relates to a method for producing a substantially horizontal borehole with such a drilling device.

Horizontal drilling serves for laying lines, pipes, ducts etc. in the ground without the need to produce a trench over the entire laying length. For horizontal drilling various types of drilling devices are known. For instance horizontal drilling devices are frequently based on the principle of displacement drilling, in which a drill head displaces in-situ ground material laterally and thereby produces the borehole. However, drilling devices of such type are only suitable for relatively soft ground conditions.

Furthermore, it is known that based on a working shaft for horizontal drilling an auger with a surrounding support pipe is used. By means of cutting tools on the drill head ground or rock material is stripped. The stripped ground material can then be discharged via a conveyor screw that is driven in a rotating manner. A problem occurring with all drilling methods for horizontal drilling resides in the precise control of the drill head. For instance during horizontal drilling for laying lines or shafts in an inner-city area this has to be implemented with a high degree of precision. Otherwise, there is the risk that cables, shafts or ducts that have already been laid or even foundations of buildings might suffer damage. A generic drilling device is known from DE 101 16 103 A1. To control the horizontal drilling process an inner drill rod with the drill head is surrounded by an outer control pipe rod. The control pipe rod has a guide section that is offset radially with respect to the drilling axis. For control, the control rod can co-rotate with the drill rod in synchronism or it can be decoupled therefrom. For this purpose, a claw coupling is provided on the joint drive, with which the control rod can be connected to or decoupled from the output side of the drive through an axial coupling movement.

From DE 10 2005 01 1 968 A1 a drilling device can be taken, which has an inner rod with a down-the-hole hammer and an outer rod. A rotary drive and a pressure drive are provided. In the interior of the inner rod an optical gap for measurement is formed, with the outer rod having an asymmetrical slope for control purposes. From US RE 37,975 E another horizontal drilling device can be taken, in which a drive unit is movable together with the drill rod on a carriage. For control, the drill bit has an asymmetrical cutting edge.

In DE 28 24 722 A1 a rotary percussive drilling device is described, in which a protective pipe is driven by a rotary drive and the rotation of the protective pipe is transmitted to a rod that is located in the protective pipe and has a core bit.

The invention is based on the object to provide a drilling device and a method for horizontal drilling which can also be used for positionally precise drilling in hard ground or rock.

In accordance with the invention the object is achieved by a drilling device having the features of claim 1 and by a method having the features of claim 11. Preferred embodiments are stated in the respective dependent claims.

The drilling device according to the invention is characterized in that the inner rod is driven in a rotating manner by a first rotary drive and the outer rod is driven in a rotating manner by a second rotary drive, in that a control means is provided, through which the first rotary drive and the second rotary drive can be set and controlled independently of each other, in that at its end on the drill head side each drill rod element has an adjusting means, by which a defined installation position of a drill rod element of the inner rod to a surrounding drill rod element of the outer rod is predetermined, and in that at the end of the drill rod elements at least of the inner rod or the outer rod facing away from the drill head a marking element is arranged, through which the position of the drill rod element relative to the drill head is visible.

One aspect of the invention is based on the fact that a drill head is used for the removal of material. However, the removed ground material is not conveyed away by a conveyor screw but through the supply of flushing liquid. The flushing liquid is passed through an annular space between the outer rod and the inner rod to the drill head. The discharge of the stripped ground material can either take place via a separate line inside the drill rod or preferably along the outside of the drill rod.

Another aspect of the invention resides in the fact that an inner space of the inner rod remains free and can thus be used as an alignment space for the control and directional monitoring of the drill head. This alignment space extends from the drive means outside the borehole almost up to the drill head. This allows for optical directional monitoring for example. However, directional monitoring can also be effected in a different way by means of the alignment space, for instance through an alignment rod or an alignment wire that are arranged along the alignment space. Other types of directional control using the alignment space are possible too.

According to a further aspect of the invention the outer rod and the inner rod are each driven by a separate rotary drive which can be controlled independently of each other especially with regard to rotational speed and direction of rotation. As a result, the two rods can be driven in synchronism or in any different chosen way in relation to each other. This enables a very precise directional control.

For a precise directional control in the case of composite drill rods it is of advantage that the individual rod elements are each mounted in a precisely defined installation position by corresponding adjusting means and marking elements. A drilling device is created which, owing to a material-removing drill head, can also be employed in hard ground and rock. The flushing liquid cools the drill head and flushes the removed ground material out of the borehole. In this, the flushing liquid is supplied in such a manner that an inner alignment space remains in the drill rod, with which a very precise, reliable control of the drill head is rendered possible.

Provision is made for the outer rod to be rotatably supported relative to the inner rod and for the drill head to be fixed on the inner rod. The rotational movement relevant for the drilling process is transmitted via the inner rod so that relatively little wear of the rotationally driven inner rod is achieved.

Furthermore, according to the invention provision is made advantageously in that the drill head is designed for producing a borehole with a drilling diameter which, for the purpose of forming a free space of return flow for the flushing liquid, is designed larger than an external diameter of the outer rod. The return flow of the flushing liquid on the outside of the drill rod brings about a cooling and a reduction of wear. The flushing liquid flowing back with the drill cuttings can be received at the end of the borehole by a collecting tank for example. From this collecting tank the discharged material can be conveyed away by means of a pump. Basically, the drill head can be designed with various types of drilling and cutting tools. According to the invention it is particularly preferred that the drill head has roller bits as drilling tools which are rotatably supported about roller axes on a drill head base. Such roller bits have roller-shaped base bodies with cutting edges arranged thereon. These serve, in particular, for stripping hard ground material as well as solid rock.

Moreover, according to the invention it is preferred that on the drill head at least one outlet opening for the outlet of the flushing liquid is arranged which is connected to the annular space. In particular, the outlet opening is designed on the plate-shaped drill head base. The outlet opening can also be designed as an outlet nozzle so that the flushing liquid is supplied under pressure and exits at the drill head as a liquid jet. This can foster the loosening of ground material and the flushing-out of the drilling tools.

According to the invention, for a positionally precise drilling the control means is provided for controlling the direction of the drilling device. By way of the control means the position of the drill head can be changed in a defined manner. For this purpose, different types of control elements are possible, such as extendable control plates. By preference, control is effected by rotationally driving the outer rod and the inner rod in the same or in a different manner.

According to the invention a particularly simple and at the same time advantageous control possibility resides in the fact that for control at least one control skid arranged on the outside of the outer rod and a turning means are provided, with which the outer rod with the control skid can be turned with respect to the inner rod in order to control the drilling device. For directional corrections the outer rod is turned until the control skid is at a position that is offset by 180° with respect to the direction, into which the drilling device is to be deflected. The further drilling progress then takes place without rotation of the outer rod so that due to the additional resistance of the radially extended control skid the drilling device swerves in the opposite direction. On continued rotational driving of the inner rod and advancing of the borehole a deflection in a smooth bend is thus brought about by the control skid, while full-surface cutting is effected by the roller bit on the working face. Once the desired deflection is reached the outer rod and the inner rod are once again rotated jointly or the control skid is retracted radially.

Moreover, for good control it is preferred that the target means in the alignment space has a target panel, which is arranged on the terminal element, and that furthermore at an end of the alignment space lying opposite the target panel a target apparatus for determining a positional deviation of the target panel from a nominal position is arranged. The target panel can in particular be a marking which is preferably illuminated. This can be implemented e.g. by suitable light-emitting diodes in the target panel which constitutes the actual target marking. The target apparatus is in particular an optically operating target apparatus which is thus arranged independently of the drill rod and can ascertain deviations of the drill head and the target panel connected thereto from a nominal position.

According to the invention it is especially preferred in the process that the target apparatus has a theodolite and a camera. A theodolite is an optical measuring apparatus for position determination which is sufficiently known from other fields of application for measurement. By way of a camera the target detection can be carried out from outside the borehole and transmitted to a chosen control unit remote from the borehole. The theodolite sets a nominal or directional axis. The target marking of the target panel lies in the directional axis. If the drill head is deflected the target marking moves out of the directional axis and triggers a corresponding counter-control until the target marking lies on the directional axis again.

In this way, deviations can also be readily detected electronically, in which case positional deviations then automatically cause a corresponding directional correction by way of the control means. However, directional correction can also be brought about manually by an operator by means of a screen display for example. Furthermore, according to the invention it is advantageous that in addition to a first rotary drive for the inner rod and a second rotary drive for the outer rod the drive means also has an axial drive for feed movement in the drilling direction.

The two rotary drives are designed in a customary manner as hydraulic drives for example. For the axial drive a so-called stepper drive with an adjustable carriage is preferably provided which can be moved by means of at least one hydraulic cylinder in a guide framework by a predetermined step length. On the movable carriage the drill rod is fixed. The step length of the axial drive is as large as or slightly larger than the length of the sections of the drill rod. In this way, bores of even greater length can be produced by composing the drill rod of a plurality of drill rod segments.

According to the invention provision is made in the process that the drill rod is composed of drill rod elements which each have connecting means at the end and in that in the annular space a partially annular stop plate is arranged at least in the region of the connecting means on the drive side. During installation of a new drill rod element or during dismantling of the drill rod the respective mounting process takes place in a rotational position, in which the opening of the partially annular or C-shaped stop plate is directed upwards. This prevents flushing liquid in the annular space of the drill rod from leaking in larger quantities from the drill rod during mounting. The connecting means can, in a manner known, have wedge couplings with corresponding axial securing parts or threaded connections. By preference, in each drill rod element a bearing is present, with which the outer rod is rotatably supported with respect to the inner rod.

The object is furthermore achieved by a method for producing a substantially horizontal borehole with the previously described drilling device, in which case provision is made in that during drilling a flushing liquid is passed through the annular space between the outer rod and the inner rod to the drill head. In this way, a drilling method with flushing liquid passed through the inner space is rendered possible, whereas at the same time the central inner space of the drill rod remains free for directional monitoring. To control the drilling device the inner rod is driven in a rotating manner by a first rotary drive and the outer rod is driven in a rotating manner by a second rotary drive, in which case a rotation of the rotary drives is set and controlled independently of each other. A preferred further development of the method resides in the fact that the flushing liquid is discharged with the drilled out ground material via a free space of return flow formed between a borehole wall and the outer rod. Through this a cooling of the drill rod as well as an improved lubrication and thus a reduction of wear is attained.

Moreover, it is advantageous for the drive means to be arranged in a shaft on a level of the borehole to be produced. For this purpose, a working or starting shaft which can receive the drive means is initially dug from the ground surface into the ground. In doing so, the drive means is arranged at a depth which approximately corresponds to the depth level of the borehole to be produced. The drilling device with the drive means is then aligned accordingly in the drilling direction. During drilling necessary directional corrections can be carried out. A simple and precise control is achieved in accordance with the invention in that the drilling device is controlled by turning the outer rod with a control skid with respect to the inner rod. By preference, the control skid can be radially extendable when a directional correction is to be carried out. If the control skid protrudes radially in a fixed manner, the outer pipe can stand still in a defined manner with respect to the inner pipe for directional correction. If no directional correction is required the outer rod and the inner rod are driven synchronously so that during the joint rotational movement the control skid constitutes a uniform resistance over the circumference.

The invention is described further hereinafter by way of preferred embodiments illustrated schematically in the drawings, wherein show:

Fig. 1 a perspective view of the drilling device according to the invention;

Fig. 2 a schematic top view with partial cross-sections of the drive means of the drilling device of Fig. 1;

Fig. 3 a schematic cross-sectional view of the drill head and the drill rod;

Fig. 4 an enlarged cross-sectional view of the drill head on the drill rod and

Fig. 5 a schematic partial cross-sectional view of a drill rod with drill head and drive units.

According to Fig. 1 a drilling device 10 pursuant to the invention has a support frame 70 which is arranged in a working shaft for horizontal drilling. The support frame 70 comprises vertical stays 74, between which two guide rails 72 are arranged horizontally and in parallel to the drilling axis. On the guide rails 72 a drive carriage 66 forming part of the drive means 60 is supported in an axially displaceable manner. For axial movement of the drive carriage 66 an axial drive 68 with two positioning cylinders 69 is provided that are arranged parallel to the guide rails 72. The positioning cylinders 69 are supported on the one hand on a rear support plate 76 and on the other hand on the drive carriage 66.

On the drive carriage 66 a first rotary drive 62 for driving an inner rod 32 and a second rotary drive 64, which is supported in front thereof in the drilling direction and designed for driving an outer rod 34, are supported. The outer rod 34 and the inner rod 32 arranged therein coaxially constitute the drill rod 30, at the front end of which a drill head 20 is fastened for removing ground material. At the rear end of the drill rod 30 before the second rotary drive 64 a rotary connection 38, also referred to as flush head, is arranged. The rotary connection 38 serves to connect a flushing liquid line, not depicted, in order to pass flushing liquid through the drill rod 30 to the drill head 20.

The drive means 60 is once more illustrated in greater detail in Fig. 2. The first rotary drive 62 and the second rotary drive 64 are designed with a hollow drive shaft so that an alignment space 40 remains inside the pipe-shaped inner rod 32. This alignment space 40 is open towards the rear end on the drive side so that directional monitoring can be effected by way of an optical target apparatus, indicated in a highly schematic manner, through the central alignment space 40. The target apparatus 54 is arranged in a receiving space behind the first rotary drive 32 and is preferably retained by an adjusting means on the support frame 70.

The outer rod 34 is designed coaxially to the drilling axis 21 and with a distance to the inner rod 32 so that an annular space 36 is designed between the inner rod 32 and the outer rod 34. Via the rotary connection 38 with the radial inlet opening 39 flushing liquid can be passed into the annular space 36.

In Fig. 3 the drill head 20 is shown in greater detail. It has a drill head base 26, on which several roller bits 22 are rotatably supported about roller axes 24 arranged transversely to the drilling axis 21. The drill head base 26 has a cone region, with which the drill head base 26 is releasably inserted into a sleeve-shaped adapter 27 with a corresponding conical receiving bore. The adapter 27 is in turn releasably fastened by means of a shaft nut 15 on the inner drive shaft 13 which is connected in a torque-proof manner to the inner rod 32. On its outside the adapter 27 is supported in a retaining sleeve 27 that is welded via a cap 14 onto an outer terminal rod 12 which is in turn connected in a torque-proof manner to the outer rod 34. By means of the adapter 27 the drill head 20 can be exchanged quickly and replaced e.g. by a drill head with a larger diameter for an expansion bore.

The connection to the outer rod is effected via a rear outer ring 17 and with respect to the pipe-shaped drive shaft 13 via an inner ring 16 which jointly form a connecting means 42 for the drill rod 30. Between the inner drive shaft 13 and the terminal rod 12 spaced radially therefrom the annular space 36 extending along the drill rod is continued, wherein on the cap 14 the annular space 36 leads via a transverse duct 18 into an outlet opening 28 towards the drill head 20.The flow of the flushing liquid through the annular space 36 towards to the drill head 20 is illustrated schematically by arrows.

The drive shaft 13 rotatably supported inside the terminal rod 12 has an inner hollow space, by which the alignment space 40 of the drill rod 30 is continued. At the end of the alignment space 40 on the drill head side a terminal element 41 is fastened, at whose front face pointing towards the alignment space 40 a target panel 52 with a target marking for the target apparatus 54 is arranged to form the target means 50.

According to Fig. 4 the support of the roller bits 22 is effected via the drill head base 26 with the conical insertion region in the funnel-shaped adapter 27. The external diameter d2 of the retaining sleeve 29, the cap 14 and the outer rod 34, not depicted, is smaller than the diameter d1 produced by the rotating roller bits 22. As a result, between the borehole wall and the external diameter of the outer rod 34 a free space is created that serves for the return flow of the flushing liquid. On the outer rod or, as shown in the present example, on the outer terminal rod 12 a control skid 35 protruding radially by the amount a is designed on a certain circumferential section. The strip-shaped control skid 35 extends parallel to the drilling axis 21 and, if not rotated together with the inner rod 32, brings about a deviation of the drill head 20 in the radially opposite direction.

The overall arrangement of the drilling device 10 is once more illustrated schematically in Fig. 5. The pipe-shaped inner rod 32 is connected via an engaging pin 63 to the first rotary drive 62 while the outer rod 34 is connected via a second engaging pin 65 to the second rotary drive 64. By way of a sleeve-shaped terminal sealing 37 the annular space 36 is sealed rearward towards the drives. The drill rod 30 can be composed of any chosen plurality of drill rod elements 31 by means of connecting means 42. The connecting means 42 have inner connecting elements 46 and outer connecting elements 47 which are in each case designed correspondingly to the respective connecting elements of the adjoining rod elements 31. On the connecting elements 46, 47 e.g. recesses or protrusions of the adjusting means are provided, through which an installation position of the inner rod 32 with respect to the outer rod 34 is visible and defined. In this way, it can be determined from outside the borehole, at which rotational position the control skid 35 is located.

The inner rod 32 driven in a rotating manner is rotatably supported via annular slide bearings 44 in the outer rod 34 that can also be driven in a rotating manner. The slide bearings 44 have openings for the passage of the flushing liquid. For mounting and dismantling of the rod elements 31 the annular space is shut off partially towards the respective end sides of the rod element 31 by means of a C-shaped stop plate 48. On a circumferential section the stop plate 48 has an opening for the passage of liquid. In line with the marking element 45, such as a recess or a protrusion, provided on the outside of the drill rod 30 this opening is arranged such that during mounting or dismantling it faces in the upward direction so that no or little liquid leaks from the annular space 36 during the mounting process. The marking element 45 also indicates the position of the drill head 20 towards the rear. A corresponding marking element can also be arranged on the rod elements 31 of the inner rod 32. The marking elements can also ensure that the individual adjoining rod elements 31 are mounted in a single defined position with respect to each other.

Starting from the retracted position depicted in Fig. 1 the drill rod 30 is driven in a rotating manner while at the same time the drive carriage 66 is moved by the axial drive 68 in the axial forward direction into the ground. As soon as the drive carriage 66 has reached its frontal end position, the connecting means 42 in front of the rotary connection 38 is released so that the drill drive carriage 66 can be reset again with the axial drive 68. Now a further drill rod element 31 can be connected to the rotary drives 62, 64 on the drive carriage 66. At the same time, a connection of the drill rod element 31 introduced into the borehole is carried out so that the drill rod 30 is now extended by a further drill rod element 31. Now a further drilling step can take place.

These drilling steps are repeated until the desired drilling length is reached. To dismantle the drill rod 30 the procedure is implemented in the reverse order.

Claims (14)

A horizontal drilling device with - a drilling head (20), - a drill rod (30) on which a drilling head (20) is arranged at the borehole end, and - a driving device (60) arranged at the drill rod (30). a second end and is designed to rotate and to displace the drill rod (30), wherein the drill rod (30) has an outer rod (34) and a rotatably mounted inner rod (32), each of which is composed of at least two drill rod elements (31), between which is formed an annular space (36) for passing a rinsing fluid from a rotatable connection (38) to the drill head (20), - the inner rod (32) comprises a directional space (40) extending from the drive device (60) up to an end member (41) on the drill head side, and - arranged in the direction space (40) at least part of a target device (50) for directional control of the drill head (20), characterized by - rotating the inner rod (32) by a first rotary drive (62) and the outer rod (34) is rotatably driven by a second rotation drive (64) independently of the first rotation drive (62), - a control means through which the first rotation drive (62) and the second rotation drive (64) can be adjusted and independently controlled, - each drill rod element (31) on the drill head side has an adjusting means at which a defined installation position of a drill rod element (31) of the inner rod (32) relative to a surrounding drill rod element (31) of the outer rod (34) is predetermined that at the end of the drill rod elements (31) at least of the inner rod (32) or outer rod (34) facing away from the drill head (20) is arranged a marking element (45) through which the position of the drill rod element (31) relative to the drill head (20) is visible. Drilling device according to claim 1, characterized in that the drilling head (20) is arranged on the inner rod (32). Drilling device according to claim 1 or 2, characterized in that the drilling head (20) is designed to produce a borehole having a borehole diameter which is designed to form a larger space for the return flow of the rinsing liquid than the outer rod (34). ) outer diameter. Drilling device according to any one of claims 1 to 3, characterized in that, as a drilling tool, the drilling head (20) has roller bits (22) which are rotatably rotatable about roller axes (24) on a drilling head base (26). Drilling device according to any one of claims 1 to 4, characterized in that at least one outlet opening (28) for the flushing liquid outlet (28) is arranged on the drilling head and which is connected to the annular space (36). Drilling device according to any one of claims 1 to 5, characterized in that at least one guide member (35) is arranged on the outer side of the outer rod (34) for guiding the drilling device (10), and a turning device is provided with which the outer rod (34) with the guide rod (35) can be rotated relative to the inner rod (32) to guide the drilling device (10). Drilling device according to any one of claims 1 to 6, characterized in that the target device (50) in the directional space (40) has a target board (52) arranged on the closing element (41) and further at one end of the directional space ( 40) positioned opposite the target board (52), a target device (54) is arranged to determine a position deviation of the target board (52) from a desired position. Drilling device according to claim 7, characterized in that the target device (54) has a theodolite and a camera. Drilling device according to any of claims 1 to 8, characterized in that the drive device (60) further has an axial drive (66) for displacement in the drilling feed direction. Drilling device according to any one of claims 1 to 9, characterized in that the drill rod elements (31) are each provided with connecting means (42) at the end and that a partially annular barrier plate (48) is arranged in the annular space (36). at least in the region of the drive members (42) on the drive side, wherein the process of mounting a drill rod element (31) or removal of the drill rod (30) takes place in a rotational position at which an opening for passage of flushing liquid into the partially annular barrier plate (48 ) is directed upwards. Method for producing a substantially horizontal borehole with a drilling device (10) according to one of claims 1 to 10, characterized in that, during drilling, a rinsing fluid is passed through the annular space (36) between the outer rod (34). and the inner rod (32) to the drill head (20). Method according to claim 11, characterized in that the rinsing liquid is discharged with the drilled soil material via a free return chamber formed between a borehole wall and the outer bar (34). Method according to claim 11 or 12, characterized in that the drive device (60) is arranged in a shaft in level with the borehole to be produced. Method according to one of claims 11 to 13, characterized in that the drilling device (10) is controlled by turning the outer rod (34) with a guide link (35) relative to the inner rod (32).