Directional drilling device

Abstract

A directional drilling device for installing a subterranean cable or pipe, the directional drilling device comprising: a housing having a drilling space extending between two openings in a side of the housing for receiving a drill string through the two openings and defining a longitudinal drilling axis; and a drive mechanism arranged in the housing for engagement with the drill string, the drive mechanism configured to move the drill string in a drilling direction along the longitudinal drilling axis and configured to selectively rotate the drill string about the longitudinal drilling axis to perform directional drilling; the driving mechanism comprises a first clamping device used for clamping a drill column. The driving mechanism further comprises a second clamping device used for clamping the drill column. Wherein the first clamping device and the second clamping device are each configured to be arranged in a clamped state, in which the drill string is clamped by the respective clamping device, and a released state, in which the drill string is movable relative to the respective clamping device, and wherein the drive mechanism is configured to move the clamping devices back and forth along the longitudinal drilling axis, and wherein the directional drilling device comprises a control device operatively connected to the drive mechanism and to the clamping device for alternately moving the clamping device and for switching the clamping device between a clamped state and a released state for performing directional drilling.

Description

Technical Field

[0001] The present invention relates to a directional drilling device for installing underground cables or pipes, a directional drilling assembly, an attachment for a small excavator, a small excavator and a method for directional drilling in the ground. Background Art

[0002] Known horizontal directional drilling systems are used for directional drilling in the ground to install pipes and pipelines where trenches are not possible or required. Such systems typically include a drill string with a steerable drill bit and a drilling device placed at an entry hole for pushing the drill string into the ground.

[0003] Known systems for horizontal directional drilling (HDD) generally require specialized equipment that is relatively large, heavy, difficult to move, and has limited operating speeds. Therefore, known HDDs are relatively expensive and are generally only used for larger pipe diameters and lengths.

[0004] An example can be found in US2020 / 0392798A1, which discloses a drilling machine with a hybrid thrust / pullback system, the drilling machine comprising a track with two drive mechanisms, a main bracket and a sub-bracket. The first drive mechanism is coupled to the main bracket and the track, and the second drive mechanism is coupled to the main bracket and the sub-bracket. The drilling machine can operate in a state where the first drive mechanism drives the main bracket along the track and the second drive mechanism drives the main bracket relative to the sub-bracket.

[0005] Therefore, to quickly install pipes or cables, especially those of smaller diameter or shorter lengths, more compact unguided rockets moved by the pressure of a pulsating fluid, such as air, are often used. The rocket is manually positioned horizontally at the desired depth in a starting pit in the ground, travels in a straight line and then hopes to emerge with luck near the desired exit pit.

[0006] However, it has been found that maps of underground cables and pipelines, while present, are not always accurate and unguided rockets may be deflected by objects in the ground. This can lead to deviations from the intended drilling path and can quickly lead to problems such as damage to existing cables, pipelines, vegetation or foundations. For example, in the case of existing power, water or gas pipelines, this can lead to dangerous or environmentally unfavorable situations that could not be avoided by good luck alone.

[0007] Therefore, it is beneficial to apply directional drilling in situations where unguided rockets are commonly used today and where existing directional systems are not suitable due to their size, weight or slow working and movement speed. In particular, when multiple relatively short boreholes are required, it is desirable to be able to steer drilling without using the large, heavy and slow existing systems.

[0008] US6279667B1 discloses a rotary push rod drilling system, which includes a push rod rotator and a push rod drilling rig having a bracket for pushing a drill string into the ground. The rotator includes a non-rotating guide tube with a spiral groove and a rotating component, the rotating component having a pin following the groove for causing rotation while being pushed by a hydraulic cylinder. The rotary pushing motion is transmitted to the drill string through a one-way sliding clamping device.

[0009] However, such devices are still relatively slow and not adaptable to varying soil types, particularly due to the need to be placed in a starting pit.

[0010] In view of current sustainability and modernization challenges, for example in existing residential areas, such as in regions with older gas-heated houses, it is desirable to provide a relatively large number of houses with a hot water network connection, a newer electricity connection with higher power and / or a fiber optic connection within a short period of time.

[0011] Purpose of the Invention

[0012] Therefore, the object of the present invention is to provide a directional drilling device for installing underground cables or pipes, which at least partially overcomes the shortcomings of the prior art, or at least provides an alternative directional drilling device, such as a directional drilling device suitable for drilling a house connection device of a utility pipeline, for example, a directional drilling device that is relatively compact and / or lightweight and can be used relatively efficiently, reliably and / or quickly. Summary of the invention

[0013] According to the invention, this object is achieved by a directional drilling device according to claim 1. The directional drilling device can be configured to install underground cables or pipes, such as building connection utility lines.

[0014] The drilling device comprises a housing having a drilling space extending between two openings in the side of the housing for accommodating a drill string passing through the two openings. The drilling space defines a longitudinal drilling axis. In use, the longitudinal axis of the drill string arranged in the drilling space will coincide with the longitudinal drilling axis.

[0015] The drive mechanism is arranged in the housing for engaging with the drill string and is configured to move the drill string in a drilling direction along the longitudinal drilling axis. The drive mechanism is configured to selectively rotate the drill string about the longitudinal drilling axis to perform directional drilling. The drilling direction can be determined by a fixed angle of the longitudinal drilling axis relative to the housing, i.e., by rotating the housing, the drilling direction can be determined relative to the ground and can be determined by rotating the drill string about the longitudinal drilling axis.

[0016] The drive mechanism comprises a first clamping device for clamping the drill string. The drive mechanism also comprises a second clamping device for clamping the drill string. The first clamping device and the second clamping device may be arranged at a distance from each other along the longitudinal drilling axis.

[0017] The first clamping device and the second clamping device are each configured to be arranged in a clamping state and a release state, in which the drill string is clamped by the corresponding clamping device, and in which the drill string can move relative to the corresponding clamping device, for example, can move in the drilling direction and rotate around the longitudinal drilling axis. The drive mechanism is configured to move the clamping device forward and backward along the longitudinal drilling axis.

[0018] The directional drilling device includes a control device operatively connected to the driving mechanism and the clamping device for alternately moving the clamping device and for switching the clamping device between a clamping state and a releasing state.

[0019] Directional drilling equipment can provide a variety of benefits:

[0020] First, since the drilling device includes two clamping devices that move alternately, drilling can be performed relatively quickly. For example, drilling can be performed by the first clamping device in a clamped state in a drilling direction, while the second clamping device is moved against the drilling direction in a released state. Subsequently, the second clamping device can be moved in the drilling direction in a clamped state, and the first clamping device can be moved against the drilling direction in a released state. In this way, a relatively continuous movement of the drill string can be obtained.

[0021] Furthermore, the mode of operation of the gripping device may be varied to provide flexibility, as will be explained herein.In addition, due to the selective rotation of the drill string about the longitudinal drilling axis, longitudinal movement of the drill string along the longitudinal drilling axis may be controlled independently of rotational movement.

[0022] Secondly, the clamping device and the two openings allow the drilling device to be relatively compact. In particular, when the drill string is clamped by the clamping device, the drill string can protrude through the two openings in the housing, so that the housing can be shorter than a single drill string section. Therefore, the weight of the device can be reduced.

[0023] In particular, the drill string can be prefabricated to be relatively long, so that during drilling, relatively little or no time is required to extend the drill string, as in the prior art. In this way, drilling can be performed substantially continuously and will therefore be very fast. In contrast to the prior art, the length of a single drill string section can be longer than the length of the drilling device. A drill string with one or more drill string sections can, for example, have the entire intended length of the borehole to be drilled in the ground before drilling, so that the borehole can be drilled in one go.

[0024] Third, because the longitudinal drilling axis is defined by the opening in the side of the housing, the drilling direction can be adjusted by rotating the housing and / or selecting the position of the opening.

[0025] Thus, the drilling device can be adapted for use in smaller locations, such as sidewalks or front yards, with relatively little disturbance compared to known directional drilling devices and other techniques, such as digging trenches in gardens and streets. The drilling device can now advantageously be small enough to be transported in a small van or on a relatively small trailer compared to the prior art.

[0026] Due to the relatively small size, relatively high speed and relatively low weight, the drilling device can be used in applications and locations not seen in the prior art because it combines speed with directional drilling. By having a drive mechanism, the physical strength required by the operator to operate the drilling device is relatively low.

[0027] Directional drilling devices are capable of drilling or drilling non-vertical holes, i.e. holes that are not completely vertical, such as approximately horizontal holes. Directional drilling devices are suitable for installing underground cables or pipes, for example, from a starting pit. Such a pit is a location where a utility line, such as a cable or pipe, is planned to enter or leave a borehole in the soil and can be excavated, for example, before drilling. However, drilling can also be performed from the soil surface without prior excavation. The directional drilling device can, for example, be configured to perform directional drilling after being positioned near a pit or soil surface, without further preparation of the pit or soil surface. The directional drilling device can be configured to perform directional drilling without being supported by the pit or the soil surface in the pit.

[0028] Compared to injecting a drill string into a pre-drilled hole, a directional drilling device can directionally drill into the soil to form a hole by pushing and / or rotating the drill string.

[0029] The openings may be arranged on opposite sides of the housing. The openings may be arranged in sides that are parallel to each other so that the drilling space determines a straight longitudinal drilling axis that determines the drilling direction. Alternatively, the openings may be arranged in sides that are angled relative to each other, for example in the top side and the front side of the housing. In this way, the drilling space may be curved. When the drill string is arranged in the drilling space, the longitudinal drilling axis is curved. The drill string may extend from the drilling space at an angle relative to the housing when being advanced along the drilling axis so that the drilling direction is angled relative to the housing.

[0030] A guide element may be provided in the drilling space and / or the opening for guiding the drill string through the opening. The position of the guide element and / or the opening may be adjustable to adjust the longitudinal drilling axis.

[0031] The housing may include a support element configured to provide support to the housing during drilling. The support unit may include an extension or stabilizer configured to support the housing against the ground surface. The extension or stabilizer may be telescopic. Additionally or alternatively, the support element may include other means for temporarily securing the housing to the ground. For example, the support element is provided with an opening through which a stabilizing pin may be inserted into the ground surface. By having a support element, the housing can be kept stationary during drilling with relatively little or no effort.

[0032] The clamping device comprising the first clamping device and the second clamping device can have any desired shape. Each clamping device can be formed, for example, by a pivotally connected segment, such as two segments. The segments can be partially circular. The segment shape corresponding to the outer contour of the drill string can be advantageous for obtaining a relatively large contact area and a relatively high clamping force.

[0033] The clamping device may be configured to circumferentially surround the drill string at the location of the respective clamping device in the clamped state. In this way, a relatively large contact surface may be obtained between the drill string and the clamping device compared to the width of the clamping device in the direction of the longitudinal drilling axis, which may be advantageous because the large width may limit the fore-and-aft movement of the clamping device.

[0034] The clamping device can be configured to have a circular internal shape corresponding to the external shape of the drill string in the clamped state. Alternatively, the clamping device can be provided with an internal shape different from the drill string, for example a non-circular shape. Therefore, the drill string can be locally elastically deformed to conform to the internal shape of the clamping device. The deformation of the drill string towards a non-circular shape can contribute to a high clamping force because it allows a higher torque to be transmitted from the clamping device to the drill string on the one hand. On the other hand, the normal force is increased due to the elastic force of the drill string material. The internal shape can be, for example, an ellipse. At least one clamping device can partially or completely have an internal shape different from the drill string, for example the shape of at least one of the clamping devices can be such that the internal clamping profile is at least partially flat, elliptical, polygonal, provided with notches and / or other profiles.

[0035] The gripping device may be shaped to have, in the released state, an inner diameter which is greater than the outer diameter of the drill string, for example an inner diameter which is greater than or equal to the smallest diameter of the opening.

[0036] The clamping device may be shaped to have, in the clamped state, an inner diameter which is smaller than or equal to the outer diameter of the drill string, for example smaller than or equal to the smallest diameter of the opening.

[0037] The clamping device may comprise at least two sections each connected to a pivot and an actuator. In an embodiment, the at least two sections are connected to the same actuator. In this way, an effective clamping device that can be controlled by a single actuator can be obtained. The actuator can be, for example, a hydraulic, pneumatic or electric piston mechanism or a gear mechanism.

[0038] The actuator may be operatively connected to the control device and the control device may be configured to control the clamping force applied by the actuator. In this way, the clamping force may be adjusted to ground type and drill string type.

[0039] The directional drilling device may include a rotation sensor configured to provide a rotation signal representative of the rotational position of the drill string. The rotation sensor may be arranged in a housing and may measure, for example, the rotation of the drill string or the rotation of the gripping device in an optical or magnetic manner. The control device may be configured to receive an operator input regarding a desired drilling direction.

[0040] The control device may be configured to cause the clamping device to move based on the rotation signal and / or received operator input.

[0041] The control means may be any control means, such as a hydraulic control means, a pneumatic control means or an electric control means. The control means may include a computer or a remote control means for inputting operator input.

[0042] The clamping device may be configured to continuously rotate the drill string in the clamped state. For example, the drive mechanism may include a rotary motor, and the clamping device may be rotated by means of the rotatable motor.

[0043] The control device may be configured to control the rotation motor so that the gripping device rotates continuously during drilling.

[0044] The control device may be designed to switch the clamping device between the clamping state and the release state within 2 seconds, for example within 0.5 seconds.

[0045] In an embodiment, the directional drilling device comprises a support configured to support the housing, wherein the support is positioned relative to the drilling space so that when the housing is supported by the support, a drill string arranged in the drilling space is directed to the surface at an angle α of -45° to 45°, such as -30° to 30°, relative to the horizontal plane. The support may be formed by a support element, a mounting bracket for attaching the directional drilling device to a tool such as an excavator, or another type of support.

[0046] The drilling space may be shaped such that the drill string leaves the drilling space perpendicular to the two open exit openings and the exit openings face the surface at an angle of -45° to 45°, such as -30° to 30°, relative to the horizontal.

[0047] Alternatively, the drilling space may be shaped so that the drill string leaves the drilling space at a non-vertical angle, wherein the drilling space is shaped so that the drill string bends into a curve when leaving the drilling space so that the drill string points to the surface at an angle of -45° to 45°, such as -30° to 30°, relative to the horizontal. The drilling space may for example be curved.

[0048] In an embodiment, the control device is configured to cause the first clamping device and the second clamping device to move alternately in the drilling direction in a clamped state.

[0049] In this way, the first clamping device moves in the drilling direction in the clamped state to advance the drill string, for example, from an initial position to a final position. Then, the first clamping device moves back to the initial position in the released state and the second clamping device moves in the drilling direction in the clamped state to further advance the drill string. Therefore, directional drilling can be performed relatively quickly.

[0050] The first and second gripping devices may move at similar or different speeds. The second gripping device may be arranged in a gripping state before the first gripping device is arranged in a released state, and vice versa. In this way, the chance of movement of the drill string while the gripping devices are simultaneously in a released state may be further reduced.

[0051] In an embodiment, the control device is configured to selectively move the first clamping device and the second clamping device simultaneously in the drilling direction in the clamped state. By moving the clamping devices simultaneously, the longitudinal movement of each of the clamping devices helps to advance the drill string, so that the force applied to the drill string can be relatively large.

[0052] The control device may for example be provided with a plurality of operating modes, such as a first mode, a second mode and / or a third mode, in which the first clamping device and the second clamping device move alternately, in which the first clamping device and the second clamping device move simultaneously, and in which one of the clamping devices does not move along the longitudinal drilling axis but only switches between a clamping state and a release state. By having a plurality of operating modes, the drilling device can adapt to the environment to provide additional speed, longitudinal force or energy efficiency, respectively.

[0053] The operating mode can be selected by an operator, for example via a remote control.

[0054] The longitudinal pressure applied to the clamping device in the direction of the longitudinal drilling axis may be adjustable.The control device may be configured to receive the desired pressure from an operator, for example via a remote control device, or to automatically control the longitudinal pressure depending on process parameters.

[0055] In this way, the longitudinal pressure can be adapted to the working conditions, such as process parameters and soil conditions. For example, to pull a pipe, cable or reamer back in a negative drilling direction, a different pressure may be required than the pressure required for drilling in the drilling direction.

[0056] In an embodiment, the rotational speed at which the drive mechanism rotates the drill string about the longitudinal drilling axis is adjustable. By increasing or decreasing the rotational speed, drilling can be adapted to the working conditions. For example, a higher rotational speed can result in faster removal of relatively dense material. The control device can be configured to receive a desired rotational speed from an operator, for example via a remote control device, or to automatically control the rotational speed based on process parameters.

[0057] The drive mechanism may, for example, comprise a motor, such as an electric motor or a hydraulic motor with a variable rotational speed, operatively connected to the control means.

[0058] The rotational speed and / or longitudinal pressure may be adjustable in discrete steps or over a continuous range.

[0059] In an embodiment in which the drive mechanism comprises a rotary motor, the rotary motor is configured to rotate the first clamping device in the clamped state about the drilling axis while rotating the second clamping device, and vice versa.

[0060] By rotating the clamping devices simultaneously, a relatively compact and durable mechanism can be provided. Furthermore, the fixed rotation difference between the clamping devices can be adapted to, for example, 90°, so that different sides of the drill string are clamped during drilling. In this way, wear or deformation of the drill string can be reduced. Thus, the two clamping devices can be rotated in their respective clamped state by the rotary motor, and the two clamping devices can be rotated in the same direction.

[0061] In an embodiment where the drive mechanism comprises a rotary motor, the rotary motor is configured to rotate the first clamping device around the drilling axis in the clamped state without rotating the second clamping device, and vice versa. Thus, the two clamping devices can be rotated by the rotary motor in their respective clamped states. Preferably, after switching the first clamping device from the clamped state to the released state and switching the second clamping device from the released state to the clamped state, the clamping devices can be rotated in the same direction to continue directional horizontal drilling in the drilling direction, and vice versa.

[0062] Instead of a single rotary motor, a plurality of rotary motors may be provided, each connected to one of the gripping devices. However, by having a single rotary motor, the drilling device may be more compact.

[0063] In an embodiment, the drive mechanism comprises a longitudinal actuator attached to the clamping device and configured to move the clamping device along the longitudinal drilling axis, wherein the rotary motor is configured to rotate the longitudinal actuator together with the clamping device. In the past, fixed longitudinal actuators have been used to achieve a relatively simple structure. However, it has been found that having a longitudinal actuator attached to the clamping device and rotating together with the clamping device allows to omit a relatively complex coupling between the rotating and non-rotating parts of the drilling device, which further contributes to achieving compactness of the drilling device.

[0064] A plurality of longitudinal actuators may be provided. For example, the longitudinal actuators may be attached to each other to form a rotatable sub-frame that can rotate about the longitudinal drilling axis. The rotatable sub-frame may be supported by bearings, such as ball bearings. The bearings may provide the only support for the sub-frame. The bearings may be disposed on the outer ends of the sub-frame along the longitudinal drilling axis in the housing to provide advantageous stability and reduce the complexity of the sub-frame.

[0065] In an embodiment, the longitudinal actuator comprises a pin, track or rod extending parallel to the drilling axis and arranged to rotate with the clamping device about the longitudinal drilling axis, wherein the clamping device is movably attached to the pin, track or rod.

[0066] The rods may for example each be piston rods of a hydraulic cylinder, a pneumatic cylinder or an electric cylinder. Each piston rod may be provided with a cylinder attached to a clamping device. The cylinder may be configured to move the clamping device parallel to the longitudinal drilling axis. The piston rod may be a continuous rod protruding from two sides of the cylinder. The cylinder may be advantageous because the cylinder may be relatively simple to maintain in a stationary position in the event of a structural or power failure, for example by closing a valve.

[0067] Additionally or alternatively, the rod may be part of a linear drive configured to move the clamping device parallel to the longitudinal drilling axis.

[0068] The outer ends of the pins, rails or rods, for example the two outer ends of a continuous piston rod, can be connected to each other to form a rotatable sub-frame. The piston rods can be connected by a connection provided with an opening drilled into the space.

[0069] A separate pin or rod may be provided for each clamping device, or multiple clamping devices may be moved by a single pin or rod.

[0070] In an embodiment, each clamping device is provided with a set of pins, rails or rods circumferentially spaced around the drilling axis. In this way, the force can be evenly distributed. The set of longitudinal actuators can be evenly spaced around the longitudinal drilling axis, for example two longitudinal actuators are arranged opposite each other or three longitudinal actuators are arranged at 120° relative to each other.

[0071] Each clamping device may be provided with a through opening to provide space for a longitudinal actuator, such as a piston rod, connected to the other clamping device.

[0072] In this way, pins, rails or rods of different clamping devices can be arranged evenly spaced apart from each other, for example around the longitudinal drilling axis.

[0073] The longitudinal actuator may be configured to provide a force of at least 1000N, for example 2500N, to each clamping device.

[0074] In an embodiment, the drilling device further comprises a bearing configured to align the drill string with the drilling axis, wherein the bearing is provided with a fluid passage for distributing fluid to the drive mechanism, wherein the fluid passage comprises a fixed port and a rotating port that rotates with the drill string.

[0075] In this way, an actuating fluid, such as oil, for actuating the clamping device and / or the longitudinal actuator can be provided relatively easily from a single bearing.The bearing can be provided with separate fixed ports and rotating ports for each clamping device.

[0076] The present invention provides a horizontal drilling assembly, which includes a directional drilling device according to any embodiment disclosed herein and a drill string to be accommodated in a drilling space of the directional drilling device, wherein the length of the drill string is greater than the length of the drilling space.

[0077] The drill string may include a head. The length of the drill string without the head may be greater than the length of the drilling space.

[0078] The drill string may include multiple sections connected to each other by couplings. The length of the drill string sections may be greater than the length of the drilling space. The couplings may include threads, form-locking couplings or other types of couplings.

[0079] The drill string may have a cylindrical shape. The head may be asymmetric so that when the drill string is rotated and moved along the longitudinal drilling axis, the drill bit moves forward along a relatively straight line, but when the drill string is moved along the longitudinal drilling axis without rotation, the drill bit moves in a drilling direction determined by the asymmetry of the head. In this way, directional drilling may be performed.

[0080] The drill string may include a relatively elastic material, such as plastic or a composite material. The elasticity may allow the drill string to have a relatively small bending radius, such as a bending radius of less than 10 meters, such as less than 5 meters, such as a bending radius of about 1 meter or 2 meters. In this way, relatively accurate directional drilling may be performed. In addition, the elasticity may allow the drill string to bend past undesirable obstacles in the ground and / or further reduce the possibility of damaging structures in the ground.

[0081] The drill string may include metal, such as aluminum or steel. The metal may provide additional strength to allow relatively high drilling forces and reduce wear. The drill string may include metal reinforcements attached to another drill string material.

[0082] The drill string may comprise a plurality of drill string sections which can be coupled to each other in a releasable manner. The drill string sections can be coupled via couplings, such as threaded couplings or bayonet couplings. The drill string sections may have a length of, for example, 1,5 meters.

[0083] The drill string can have a greater length than the length of the drilling device. In this way, very high working speeds are possible, since it is no longer necessary to frequently connect new drill string sections. The use of a relatively long drill string in combination with not having to place the drilling device in a starting pit that would limit the drilling length contributes to a favorable speed of the drilling device.

[0084] In particular, compared to the prior art, the drill string sections may have a greater length than the length of the drilling device.

[0085] The drilling device may have a length of less than 2,5 meters, for example less than 1,5 meters. The drill string may have a length of more than 2,5 meters, for example 6 meters.

[0086] The diameter of the drill string may be less than 15 cm, such as less than 10 cm, for example 2 cm to 5 cm.

[0087] The drill string may include a drilling fluid passage extending from the drill bit toward a fluid inlet port to provide drilling fluid at the drill bit. The fluid inlet port may be disposed at a rear end of the drill string. The fluid inlet port may be connected to a drilling fluid source, such as water or a bentonite source.

[0088] The drilling fluid pressure at the drill bit may be adjustable. For example, the control device may be configured to regulate a valve or pump fluidly connected to a drilling fluid source.

[0089] In an embodiment, each clamping device defines an inner clamping diameter, wherein in the clamped state the inner clamping diameter is smaller than the diameter of the drill string, such that the drill string deforms locally to improve the clamping between the clamping device and the drill string. It has been found that elastic deformation of the drill string can contribute to high clamping forces.

[0090] The clamping device may be shaped differently from the drill string, so that the drill string is deformed into another shape. At least one of the clamping devices may partially or completely have an internal shape different from the drill string, for example, at least one of the clamping devices may be shaped such that in the clamped state the internal clamping contour is at least partially flat, elliptical, polygonal, provided with notches and / or other contours. In the case of a drill string having a substantially circular cross section, the drill string may be deformed into a non-circular shape in the clamped state of the corresponding clamping device.

[0091] In an embodiment, a directional drilling device includes an interface, such as a display, wherein the drill string includes a fluid channel, a tracking device configured to transmit a tracking signal, wherein the interface is configured to receive the tracking signal and display position data representing the position of the tracking device based on the tracking signal, wherein the tracking device is disposed in a tracking device compartment in the drill string that is separated from the fluid channel.

[0092] The interface can be used as a remote control device.

[0093] The tracking device may emit a signal, such as a magnetic signal, which is detected by a monitoring device on the surface, or vice versa. The tracking device may include sensors, such as accelerometers, magnetometers, and gyroscopes. The interface may be configured to display an estimated position of the drill string based on position data, such as actual drill head angle, input from an operator or control device, and / or an initial position of the drill string.

[0094] The interface may be a screen, display, phone or computer, or a software interface provided on an external device, such as a cloud interface.

[0095] The control device can be configured to control the gripping device based on the tracking signal. In this way, drilling can be performed automatically.

[0096] In an embodiment, the horizontal drilling device includes an extension associated with the housing and configured to be arranged in a guiding position to guide a portion of the drill string protruding through one of the two openings to the exterior of the housing to avoid bending of the drill string portion away from the longitudinal axis.

[0097] In certain circumstances, such as when a relatively elastic drill string is used and / or when the drill string encounters relatively hard soil, the drill string may bend away from the longitudinal drilling axis between the ground entry point and the housing.

[0098] By having two clamping devices, the directional drilling device supports the drill string in the housing at least at two support points during drilling, which reduces the bending of the drill string compared to having a single clamping device. By having an extension, the drill string can be supported between the housing and the soil, so that the bending of the drill string is further advantageously reduced.

[0099] The extension can be arranged in a guiding position to guide the drill string portion to avoid bending of the drill string away from the longitudinal axis.

[0100] The extension is removable from the housing to guide the drill string portion in a guide position of the extension. Additionally or alternatively, the extension is moveable between a guide position and a storage position in which the extension is configured to guide the drill string portion.

[0101] The extension may include a mounting element for mounting the extension to the housing and a guide element for guiding the drill string portion. The guide element may be configured to support the drill string along the longitudinal axis in a guiding position. The guide element may include an inlet opening and an outlet opening. For example, the guide element may include a hollow shape, such as a tubular shape. The extension may include a mounting element arranged so that when mounted, the inlet opening of the extension faces the opening of the housing for accommodating the drill string through the corresponding opening of the housing and the inlet opening.

[0102] The housing may include a second mounting element configured to cooperate with the mounting element to attach the extension to the housing.The mounting element and the second mounting element may, for example, include a pin hole, a bolt connection or a latch connection.

[0103] The second mounting element may be formed by at least one of the supporting elements of the housing. In particular, the supporting element and the mounting element may each be provided with an opening through which the supporting element and the second mounting element may be connected. The opening of the second mounting element and the opening of the supporting element may be shaped such that a stabilizing pin may be inserted into the ground through the opening. Thus, the housing and the extension may be attached to each other and fixed to the ground using a single action, such as inserting a stabilizing pin.

[0104] In directional drilling devices not according to the present invention, extensions may also be beneficial and provide advantages.

[0105] According to another aspect, the present invention provides an attachment for an excavator, such as a small excavator, which includes a directional drilling device according to any embodiment of the embodiments disclosed herein or a horizontal drilling assembly according to any embodiment of the embodiments disclosed herein and an excavator mounting part for attaching the directional drilling device to the excavator.

[0106] As explained above for the directional drilling device, several advantages can be obtained with this attachment. By using the directional drilling device as an attachment, the excavator can be used for multiple purposes, the directional drilling device can be supported by the excavator during drilling and / or can be powered by the excavator during drilling.

[0107] The excavator mount may include a mounting bracket, such as a quick release mounting bracket, for mounting the drilling device to a small excavator.

[0108] The mounting bracket is rotatable about a generally vertical axis so that the horizontal orientation of the longitudinal drilling axis relative to the excavator can be adjusted.

[0109] The mounting bracket is rotatable about a generally horizontal axis so that the vertical orientation of the longitudinal drilling axis relative to the excavator can be adjusted.

[0110] The excavator may provide support to the housing during drilling. The mounting bracket may serve as a support element configured to provide support to the housing during drilling. In particular, the excavator may be relatively heavy, so that the housing is fixed relative to the ground by being attached to the excavator.

[0111] When attached to the excavator, the attachment may be supported by the excavator so that the weight of the attachment is carried by the excavator rather than, for example, by the soil directly below the attachment. Thus, the soil in the starting pit may carry less or no load, which may be beneficial because the soil in the starting pit may be weakened by the drilling activity, for example by the drilling fluid.

[0112] The attachment may be configured to be transportable on, ie, sized to fit in, a small truck or a conventional tandem axle trailer.

[0113] The present invention provides an excavator, which includes an attachment according to any embodiment of the embodiments disclosed herein, wherein the attachment is provided with a power connection to a power system of a small excavator for providing power to a drive mechanism. The power system can be an electric system, a pneumatic system, a hydraulic system or other system capable of providing power to a directional drilling device. For example, the attachment is provided with a fluid connection to a fluid system of a small excavator for providing power to a drive mechanism in a hydraulic manner. The excavator can advantageously be a relatively small excavator having a weight of less than 6000kg, for example less than 3000kg, such as 1000kg to 2000kg. The excavator can be a small excavator.

[0114] The excavator may provide power, such as electricity and / or hydraulics, and may thereby be used as a power source. Additionally or alternatively, the excavator may provide support to the directional drilling device. Furthermore, by including the directional drilling device as an add-on device for the excavator, only the add-on device may be required in addition to the excavator that is typically already present at the cable laying site. Thus, an additional separate power source or support device for horizontal drilling may not be required for performing both the excavation operation and the drilling operation.

[0115] However, the directional drilling apparatus can additionally or alternatively operate independently or on another tool.For example, a support configured to provide support to the housing during drilling may be provided.

[0116] The invention also relates to the use of a drilling device, an attachment or an excavator for directional drilling in the ground.

[0117] The present invention provides a method for horizontal directional drilling, comprising the following steps: providing a drill string in a directional drilling device, wherein the length of the drill string, for example the length of the drill string without its drill bit, is greater than the length of the directional drilling device;

[0118] Positioning the device so that the drill string enters the surface at a desired angle, for example, at an angle of -45° to 45°, such as -30° to 30°, relative to the horizontal plane;

[0119] Clamping the drill string with a first clamping device and moving the first clamping device parallel to the longitudinal drilling axis away from an initial position to advance the drill string into the ground;

[0120] releasing the first gripping device and gripping the drill string with the second gripping device, and moving the second gripping device parallel to the drilling axis to further advance the drill string into the ground;

[0121] While advancing the drill string using the first gripping device and / or the second gripping device, rotating the drill string about the drilling axis to advance the drill string along a straight path, and holding the drill string in a fixed rotational position to advance the drill string along a curved path corresponding to the fixed rotational position; and

[0122] While the drill string is advanced with the second clamping device, the first clamping device is moved back to the initial position, for example for continued drilling, or the first clamping device and the second clamping device are moved together in the clamped state, for example for drilling with greater force.

[0123] The drill string may comprise a plurality of drill string sections. The length of the drill string section may be greater than the length of the directional drilling device. The drill channel may have a diameter of less than 15 cm, such as less than 10 cm, for example 2 cm to 5 cm.

[0124] In an embodiment, the method further comprises the steps of attaching the reamer and / or a common line, such as a pipe or cable, to the drill string while drilling, and then retracting the drill string by gripping the drill string while moving the gripping device in the opposite direction. The common line may be coupled to the drill bit and / or to the reamer via a rotatable coupling.

[0125] According to the invention, a relatively high clamping force can be obtained while the drill string can be moved at a relatively high speed. In the prior art, the clamping force is limited, so that one or more separate reaming steps are usually required before the common pipeline can be pulled through the soil. Since a relatively high clamping force can be obtained according to the invention, the reamer and the common pipeline can be attached to the drill string while drilling, and reaming and pulling the drill string through the drilled pipe can be performed during a single reverse movement of the drill string until a relatively high diameter is reached, for example for pulling a common pipeline, such as a cable or a pipeline, which may have a diameter of up to 20 mm, in particular up to 10 mm.

[0126] In an embodiment, the method further comprises the following steps: before drilling, digging a starting pit and / or an exit pit using a tool, such as a small excavator;

[0127] Optionally, removing an excavating device, such as an excavator bucket, from the tool;

[0128] attaching a directional drilling device to the tool;

[0129] and performing the step of advancing the drill string from the starting pit and / or towards the exit pit using the directional drilling device. The step of advancing the drill string is performed using the directional drilling device attached to the tool. Thus, both digging a pit, such as the starting pit and the exit pit, and the drilling itself can be performed using a single tool. In particular, now only one tool, such as a small excavator, may be required to perform the steps of digging a pit and drilling. The small excavator may be used as a power source and provide support to the directional drilling device.

[0130] The use and the method can be carried out, for example, in sand, peat or clay, such as is typical in the Netherlands.

[0131] The use and method may provide similar advantages as explained herein for the drilling device, attachment and excavator. Especially for connecting houses to common pipelines in existing communities, the present invention may provide a combination of speed, safety and precision not seen in the prior art, and thus may significantly help connect houses to faster Internet and sustainable heat sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0132] Other features of the invention will be explained below with reference to the embodiments shown in the accompanying drawings, in which:

[0133] Figure 1 schematically depicts a top view of an attachment for an excavator according to an embodiment of the present invention;

[0134] Figure 2 schematically depicts the Figure 1 A side view of a cross section of the attachment device along line AA;

[0135] Figure 3A schematically depicts an enlarged side view of the clamping device and the longitudinal actuator of the embodiment of FIG. 2 , wherein the clamping device is in an initial position according to a first operating mode;

[0136] Figure 3B Schematically depicts the Figure 3A An enlarged side view of the device, wherein the clamping device moves along the longitudinal axis toward the second position according to the first operating mode;

[0137] Figure 4A schematically depicts an enlarged side view of the clamping device and the longitudinal actuator of the embodiment of FIG. 2 , wherein the clamping device is in an initial position according to a second operating mode;

[0138] Figure 4B Schematically depicts the Figure 4A An enlarged side view of the device, wherein the clamping device moves along the longitudinal axis toward the second position according to the second operating mode;

[0139] Figure 5A schematically depicts a clamping device with an attached cylinder and piston according to an embodiment of the present invention;

[0140] Figure 5B Schematically depicts Figure 5A A rear view of the clamping device;

[0141] Figure 5C Schematically depicts Figure 5A A front view of a clamping device;

[0142] Fig. 6A schematically depicts an embodiment of a directional drilling apparatus provided with an extension member; and

[0143] Figure 6B Schematic depiction of the use of Fig. 6A The directional drilling device of the embodiment of the present invention advances the drill string from the starting pit.

[0144] Throughout the drawings, the same reference numerals are used to designate corresponding parts or parts having corresponding functions. DETAILED DESCRIPTION

[0145] Figure 1Schematically depicted is a top view of an attachment 10 for an excavator, the attachment 10 comprising a drilling device 1 having a housing 2 having a drilling space 20 extending between two openings 21, 22 in the sides of the housing for accommodating a drill string 90 passing through the two openings 21, 22, the two openings 21, 22 being arranged on opposite sides of the housing 2 parallel to each other. The drilling space 20 defines a longitudinal drilling axis A of the drill string 90. Bearings 6, 6' are arranged close to the openings 21, 22 and guide the drill string 90. A support element 24 provided with an opening 23 is provided to provide support for the housing when deemed necessary by pushing the support element 24 towards the ground surface or by inserting a stabilizing pin through the opening 23 into the ground to temporarily fix the housing 2 to the ground.

[0146] The drive mechanism 3 is arranged in the housing for engaging with the drill string 90 and is configured to move the drill string in a drilling direction d along the longitudinal drilling axis A. Since the openings 21 , 22 are arranged in a straight line, the longitudinal axis A enters the housing 2 perpendicularly to the drilling device 2 , so that the initial drilling direction of the drill string is perpendicular to the housing 2 .

[0147] The driving mechanism comprises a first clamping device 31 and a second clamping device 32 for clamping the drill string 90 , the first clamping device 31 and the second clamping device 32 being arranged along the longitudinal drilling axis A at a distance from each other.

[0148] The first clamping device 31 and the second clamping device 32 are each configured to be arranged in a clamping state and a released state, such as Figure 5B and Figure 5C As shown in FIG. 1 , in the clamped state, the drill string 90 is clamped by the corresponding clamping device, and in the released state, the drill string 90 can move relative to the corresponding clamping device in the drilling direction d and rotate around the longitudinal drilling axis A. The driving mechanism 3 is configured to selectively rotate the drill string around the longitudinal drilling axis A to perform directional drilling by moving the clamping devices 31, 32 backward in the negative drilling direction along the longitudinal drilling axis A and forward in the drilling direction d.

[0149] The clamping devices 31, 32 are shaped similar to Figure 5B and Figure 5C The clamping device D1 includes two part-circular segments 56 which are pivotally connected via a pivot hinge 57 and have a circular inner shape corresponding to the outer contour of a circular drill string 90 in the clamped state so as to circumferentially surround the drill string 90 in the clamped state. In the clamped state, the inner diameter D1 of the clamping device D1 is smaller than or equal to the outer diameter of the drill string 90.

[0150] In this embodiment the inner clamping shape is circular, but the inner shape of the clamping device may alternatively differ from the outer shape of the drill string such that the drill string is deformed into another shape, for example a non-circular shape, such as a slightly oval shape.

[0151] The gripping devices 31, 32 are provided with an actuator 58, which in this embodiment is a hydraulic cylinder with a piston, which is pivotally connected to the two sections 56 via a hinge 57'. In the released state, the piston extends from the cylinder so that the hinges 57' are pushed away from each other. In the released state, the inner diameter D1 of the gripping devices 31, 32 is greater than the outer diameter of the drill string 90 and greater than or equal to the smallest diameter of the openings 21, 22.

[0152] The clamping device may be provided with a friction surface 59, such as a structured surface or padding of a high friction material, for increasing the clamping force.

[0153] The directional drilling device includes a control device 4, which is operatively connected to the drive mechanism 3 and the actuator 58 of the clamping devices 31, 32 via hydraulic connections 43, 44, and to the bearing 6 via hydraulic lines (not shown). The control device 4 can be connected to, for example, a sensor 45 via an electric wire 42 in addition or alternatively. In this embodiment, the control device includes a computer and a hydraulic adjustment device. The remote control device 7 is a touch interface configured to receive input operator input, and is used as a remote control device by wirelessly communicating with the control device, for example via a wireless Internet connection.

[0154] The control device 4 is configured to control the clamping force applied by the actuator by regulating the flow of hydraulic fluid via a valve or a pump. The directional drilling device 1 includes a rotation sensor 45, which is an optical sensor in this embodiment. The rotation sensor 45 is arranged in the housing 2 and is configured to provide a rotation signal representing the rotational position of the drill string 90.

[0155] The control device 4 is configured to wirelessly communicate with the remote control device 7 and receive operator input regarding the desired drilling direction. The control device 4 is configured to move the clamping devices 31, 32 based on the rotation signal and / or the received operator input. The control device 34 is configured to switch the clamping device between the clamping state and the release state within 2 seconds, for example within 0.5 seconds.

[0156] The control device 4 is configured to operate in multiple operating modes and receive a desired operating mode from the remote control device 7. FIG. 3A to FIG. 3B The first mode of operation is depicted in FIG. 4A to FIG. 4B A second mode of operation is depicted in FIG.

[0157] In the first mode, the first clamping device 31 and the second clamping device 32 are alternately moved in the drilling direction by the controller in the clamping state. The first clamping device 31 moves in the drilling direction d in the clamping state to move the drill string 90 from the drilling direction d to the drilling direction d. Figure 3A The initial position of the first clamping device 31 depicted in FIG. Figure 3B The final position of the first clamping device 31 depicted in FIG. At the same time, the second clamping device 32 is released from Figure 3A Move the position to Figure 3B position to achieve Figure 3B The location depicted in .

[0158] Then, the first clamping device 31 moves back to the position in the released state. Figure 3A The second clamping device 32 moves in the drilling direction d in the clamping state to further advance the drill string 90, thereby achieving Figure 3A This alternating motion may be repeated until the drill string 90 is fully advanced, for example when the drill bit 91 reaches the exit position and extends from the ground.

[0159] In the second mode, the control device 4 positions the clamping devices 31, 32 Figure 4A Then, the first clamping device 31 and the second clamping device 32 are simultaneously moved along the drilling direction d to reach Figure 4B at the location.

[0160] In this mode, the control device 4 selectively enables the clamping device to move along the drilling direction D while in the clamped state.

[0161] The two clamping devices can then be switched to the released state simultaneously and moved back to Figure 4A If the simultaneous movement of the gripping devices 31, 32 in the released state will result in an undesired movement of the drill string 90, one of the gripping devices 31, 32 may first be moved from Figure 4B Move the position to the release state Figure 4A position, arranged in a clamping state to clamp the drill string 90, after which the other of the clamping devices is subsequently moved back to Figure 4A location.

[0162] The second operating mode is slower than the first operating mode, but provides additional force in the direction of the longitudinal drilling axis, for example in compacted soil. A third operating mode may also be provided, in which one of the clamping devices does not move along the longitudinal drilling axis, but only switches between a clamped state and a released state.

[0163] The drive mechanism 3 comprises a motor 33, such as an electric motor or a hydraulic motor, operatively connected to the control device 4. The rotation speed and / or the longitudinal pressure are adjustable within a continuous range by varying the voltage or the hydraulic fluid flow rate using the controller 4. The rotation motor 33 is configured to rotate the first clamping device 31 around the longitudinal drilling axis A in a clamped state while rotating the second clamping device 32, and vice versa.

[0164] The drive mechanism 3 comprises a longitudinal actuator 5 attached to the clamping devices 31 , 32 and configured to move the clamping devices along the longitudinal drilling axis A. A rotary motor 33 is configured to rotate the longitudinal actuator 5 together with the clamping devices 31 , 32 via a chain 35 or belt attached to a rotor 34 of the motor 33 .

[0165] The longitudinal actuators 5 are attached to each other by circular plates 36 to form a rotatable sub-frame which is rotatable about the longitudinal drilling axis A and supported by ball bearings 6, 6' on the outer ends of the rotatable sub-frame, which form the only support for the sub-frame. One of the circular plates 36 is provided with a sprocket 36' for rotation via a chain 35. Between the circular plates 36, reinforcing beams 37 extending parallel to the longitudinal drilling axis are provided to provide additional rigidity to the rotatable sub-frame.

[0166] Each longitudinal actuator 5 comprises a hydraulic cylinder 52 attached to the respective clamping device 31, 32, the hydraulic cylinder 52 having a continuous piston rod 51 protruding from both sides of the cylinder 52 and extending parallel to the longitudinal drilling axis A and arranged to rotate together with the clamping device 31, 32 about the longitudinal drilling axis A. Since the cylinder 52 is movable on the piston rod 51 and is fixed to the clamping device by a mounting plate 54, the clamping device is attached to the piston rod 51 in a movably manner. The cylinder 52 is configured to move the respective clamping device 31, 32 parallel to the longitudinal drilling axis.

[0167] The outer ends of the continuous piston rods 51 are connected to each other at two outer ends 53 by connecting elements, for example plates 36 provided with drilled space openings, to form a rotatable sub-frame.

[0168] Each clamping device 31, 32 is provided with a set of two cylinders 52 with piston rods 51, the two cylinders 52 being evenly spaced apart, i.e. 180° relative to each other, on opposite sides of the axis A. The mounting plate 54 of each clamping device is provided with a through opening 55 to provide space for a longitudinal actuator 52', such as a piston rod, connected to the other clamping device. The cylinders 52 each provide a force of at least 1000N, such as 1250N, thus for example 2500N, to each clamping device 31, 32.

[0169] The longitudinal pressure applied to the gripping devices 31, 32 in the direction of the longitudinal drilling axis A is adjustable, and the rotational speed of the motor 33 is adjustable. The control device 4 is configured to receive the desired pressure and rotational speed from an operator, for example via a remote control device 7, or to automatically control the longitudinal pressure and rotational speed depending on process parameters such as measured torque or force.

[0170] The bearings 6, 6' are configured to align the drill string 90 with the drilling axis A. One of the bearings 6 is provided with a fluid channel 61 for distributing fluid to the drive mechanism, wherein the fluid channel 61 includes a fixed port and a rotating port for each clamping device and for each longitudinal actuator. The rotating port rotates with the subframe and the drill string 90.

[0171] The drill string 90 has a cylindrical shape and includes an asymmetric drill head 91, so that when the drill string rotates and moves along the longitudinal drilling axis, the drill head moves forward along a relatively straight line, but when the drill string moves along the longitudinal drilling axis without rotating, the drill head moves in a drilling direction determined by the asymmetry of the head. In this way, directional drilling can be performed.

[0172] The drill string comprises a relatively elastic plastic, resulting in a bending radius of less than 10 meters, such as less than 5 meters, for example a bending radius of about 1 meter or 2 meters. The drill string also includes a coupling 94 for releasably coupling a plurality of drill string sections to each other, in this case via a bayonet coupling. The coupling 94 and the drill bit 91 are made of steel.

[0173] The drill string section may for example have a length L1 of 1.5 meters or more, which is greater than the length of the drilling device 1. The drilling device has a length of less than 2.5 meters, in particular less than 1.5 meters. In this way, the attachment 11 is configured to be transportable on a small truck or a conventional double-axle trailer. In this embodiment, the drill string has a length of a single section, but a plurality of sections may be coupled to a length greater than 2.5 meters, for example 6 meters. The diameter of the drill string is less than 15 cm, for example less than 10 cm, for example 2 cm to 5 cm.

[0174] The drill string includes a drilling fluid passage extending from an opening 92 in the drill bit 91 toward a fluid inlet port 95 at the rear end of the drill string 90 to connect to a drilling fluid source, such as a source of water or bentonite. The drilling fluid pressure at the drill bit 91 is adjustable. The control device 4 is configured to wirelessly communicate with the drilling fluid source to adjust a valve or pump fluidly connected to the drilling fluid source based on operator input or process parameters.

[0175] The drill string 90 comprises a tracking device compartment 93 separated from the drilling fluid passage for housing a tracking device configured to emit magnetic tracking signals. The remote control device 7 comprises a display and is configured to receive the tracking signals and to display position data representing the position of the tracking device based on the tracking signals.

[0176] The remote control device 7 may receive data from the tracking device directly or via a monitoring device on the surface. The tracking device includes sensors such as accelerometers, magnetometers, and gyroscopes. The remote control device 7 is configured to show an estimated position of the drill string 90 based on position data including, for example, actual drill head angle, input from an operator, and an initial position of the drill string.

[0177] The attachment 10 comprises an excavator mount, which in this embodiment is a quick release mounting bracket 11 for mounting the drilling device 1 to a small excavator. Additionally or alternatively other mounts may be provided for mounting the attachment to other tools.

[0178] The mounting bracket 11 is rotatable about a substantially vertical axis V and a substantially horizontal axis H so that the vertical and horizontal orientation of the longitudinal drilling axis A relative to the excavator can be adjusted. The attachment 10 is provided with a fluid connection 41 to the fluid system of a 1000kg to 2000kg small excavator for powering the drive mechanism 3.

[0179] like Fig. 6A and Figure 6B As shown in FIG. 1 , the directional drilling device 1 may optionally be provided with an extension member 70 configured to guide a portion of the drill string 90 protruding through the opening 21 to the outside of the housing 2. Fig. 6A As shown in FIG. 1 , the extension member 70 can be removed from the housing 2 to guide the drill string section to a position such as Figure 6B In the embodiment of the present invention, the extension 70 is provided with a guide position of attachment shown in FIG. Additionally or alternatively, the extension 70 may be hingedly connected to the housing 2 to be movable between a guide position in which the extension is configured to guide a drill string portion and a storage position. The extension 70 comprises a mounting element 73 for mounting the extension 70 to the housing 2 and a hollow tubular guide element configured to support the drill string along the longitudinal axis A in the guide position. The guide element comprises an inlet opening 71 and an outlet opening 72.

[0180] The support element 24 on the housing 2 forms a second mounting element configured to cooperate with the mounting element 74 to attach the extension piece 70 to the housing 2. When mounted, the inlet opening 71 of the extension piece faces the opening 21 of the housing 2.

[0181] The support element 24 and the mounting element 74 are each provided with a respective opening which is shaped such that the stabilizing pin 25 can be inserted therethrough into the ground 97 .

[0182] In use, a drill string 90 is provided in the directional drilling device 1. The length of the drill string, for example without its drill bit, is greater than the length of the directional drilling device 1 in this embodiment. The device 1 is then positioned near the starting pit by a small excavator via the attachment 11, which provides support to the housing and is arranged so that the drill string 90 is directed to the surface at a desired angle α, for example at an angle α of -45° to 45°, such as -30° to 30°, relative to the horizontal plane.

[0183] Optionally, an extension 70 may be provided to provide additional support to the drill string 90 to avoid bending of the portion of the drill string 90 between the housing 2 and the ground 97. The extension 70 may be attached to the housing 2 and the housing 2 may be fixed to the ground 97 by inserting at least one of the stabilizing pins 25, for example 2 stabilizing pins, through corresponding openings in the support element 24 and the mounting element 74.

[0184] The drill string 90 is clamped with the first clamping device 31, and the first clamping device 31 is moved away from the initial position parallel to the longitudinal drilling axis A to advance the drill string into the ground. The drill string 90, in particular a single drill string section, may have a length L1 that is longer than the length L2 of the drilling space. The first clamping device 31 is then released and the drill string 32 is clamped with the second clamping device 32 and further moved parallel to the drilling axis A to advance the drill string 90. At the same time, the drill string 90 is rotated about the drilling axis A to advance the drill string 90 along a straight path, and when a change of direction is required, the drill string 90 is maintained in a fixed rotational position to advance the drill string along a path that is curved corresponding to the fixed rotational position due to the asymmetric drill bit 91.

[0185] While the drill string 90 is advanced by the second gripping device 2, the first gripping device 31 moves back to the initial position for continued drilling in the first operating mode. Alternatively, the first gripping device 31 moves together with the second gripping device 32 for drilling with greater force.

[0186] When the desired position is reached with the drill bit 91, the reamer 96 and / or a common pipeline, such as a pipe or cable, is attached to the drill string 90, and then the drill string 90 is moved in a backward direction, i.e., in the opposite direction to the drilling direction, by clamping the drill string while moving the clamping devices 31, 32 in the opposite direction to the drilling direction. The common pipeline can be connected to the drill bit and / or the reamer via a rotatable coupling.

[0187] Since a relatively high clamping force can be obtained and the drill string can be moved at a relatively high speed, the reamer and the common line can be attached to the drill string simultaneously while drilling, and reaming and pulling the drill string through the drilled pipe can be performed during a single reverse movement of the drill string until a relatively high diameter is reached. The common line can, for example, have a diameter of up to 10 mm.

Claims

1. A directional drilling device (1) for installing underground cables or pipes, the directional drilling device (1) comprising: a housing (2) having a drilling space extending between two openings (21, 22) in the sides of the housing for receiving a drill string (90) passing through the two openings and defining a longitudinal drilling axis (A); as well as a drive mechanism (3) arranged in the housing for engagement with the drill string, the drive mechanism (3) being configured to move the drill string in a drilling direction (d) along the longitudinal drilling axis and to selectively rotate the drill string about the longitudinal drilling axis to perform directional drilling; wherein the drive mechanism comprises a first clamping device (31) for clamping the drill string; Wherein, the driving mechanism further comprises a second clamping device (32) for clamping the drill string; The first clamping device (31) and the second clamping device (32) are each configured to be arranged in a clamping state and a release state, wherein in the clamping state, the drill string (90) is clamped by the corresponding clamping device, and in the release state, the drill string can move relative to the corresponding clamping device. wherein the driving mechanism (3) is configured to move the clamping device forward and backward along the longitudinal drilling axis (A), and The directional drilling device comprises a control device (4), which is operatively connected to the driving mechanism and the clamping device so as to cause the clamping device to move alternately and to cause the clamping device (31, 32) to switch between the clamping state and the releasing state to perform directional drilling.

2. Directional drilling device according to the preceding claim, wherein: The directional drilling device includes a support configured to support the shell, wherein the support is positioned relative to the drilling space so that when the shell is supported by the support, a drill string arranged in the drilling space points to the ground surface at an angle (α) of -45° to 45°, such as -30° to 30°, relative to a horizontal plane.

3. The directional drilling device according to claim 1 or 2, wherein: The control device (4) is configured to cause the first clamping device (31) and the second clamping device (32) to move alternately along the drilling direction in the clamping state.

4. A directional drilling device according to any one of the preceding claims, wherein: The control device is configured to selectively move the first clamping device (31) and the second clamping device (32) along the drilling direction in the clamping state simultaneously.

5. A directional drilling device according to any one of the preceding claims, wherein: The rotation speed of the driving mechanism (3) to rotate the drill string around the longitudinal drilling axis is adjustable.

6. A directional drilling device according to any one of the preceding claims, wherein: The driving mechanism comprises a rotary motor (33) for rotating the first clamping device and the second clamping device, wherein the rotary motor (33) is configured to: - rotating the first clamping device (31) around the drilling axis in the clamped state while rotating the second clamping device (32), and vice versa, rotating the second clamping device (32) around the drilling axis in the clamped state while rotating the first clamping device (31), or - rotating the first clamping device in the clamped state about the drilling axis without rotating the second clamping device, and conversely, rotating the second clamping device in the clamped state about the drilling axis without rotating the first clamping device.

7. The directional drilling device according to claim 6, wherein: The drive mechanism comprises a longitudinal actuator (5) attached to the clamping device (31, 32) and configured to move the clamping device along the longitudinal drilling axis, Wherein, the rotary motor is configured to rotate the longitudinal actuator (5) together with the clamping device.

8. The directional drilling device according to claim 7, wherein: The longitudinal actuator comprises a pin, track or rod (51) extending parallel to the drilling axis and arranged to rotate together with the clamping device around the longitudinal drilling axis, wherein the clamping device (31, 32) is movably attached to the pin, track or rod.

9. The directional drilling device according to any one of the preceding claims, further comprising a bearing (6) configured to align the drill string (90) with the drilling axis, wherein The bearing is provided with a fluid passage (61) for distributing fluid to the drive mechanism (3), wherein the fluid passage comprises a fixed port and a rotating port that rotates with the drill string.

10. The directional drilling device according to any one of the preceding claims, further comprising an extension member (70), which is associated with the housing (2) and is configured to be arranged in a guiding position to guide a portion of the drill string protruding to the outside of the housing through one of the two openings (21), thereby avoiding bending of the portion of the drill string away from the longitudinal drilling axis (A).

11. A directional drilling assembly, comprising: A directional drilling device (1) according to any one of the preceding claims, and a drill string (90) received in the drilling space of the directional drilling device, wherein, for example without a drill bit, the length (L1) of the drill string (90) is greater than the length (L2) of the drilling space, for example, wherein the length of a drill string section is greater than the length (L2) of the drilling space.

12. The directional drilling assembly of claim 11, wherein: Each clamping device defines an inner clamping diameter (D1), wherein in the clamped state, the inner clamping diameter (D1) is smaller than the diameter of the drill string (90), so that the drill string is locally deformed to improve the clamping between the clamping device (31, 32) and the drill string.

13. The directional drilling assembly of claim 12, wherein: At least one of the clamping devices is provided with an internal clamping shape that is different from the external shape of the drill string, so that the drill string is deformed into another shape, for example a non-circular shape.

14. The directional drilling assembly according to any one of claims 11 to 13, wherein: The directional drilling device comprises an interface (6), such as a remote control device, wherein the drill string (90) comprises a drilling fluid passage and a tracking device configured to transmit a tracking signal, wherein the interface is configured to receive the tracking signal and to display position data representing the position of the tracking device based on the tracking signal, The tracking device is arranged in a tracking device compartment (93) in the drill string which is separated from the drilling fluid channel.

15. An attachment (10) for an excavator, such as a mini excavator, comprising a directional drilling device according to any one of claims 1 to 10 or a horizontal drilling assembly according to any one of claims 11 to 14 and an excavator mounting for attaching the directional drilling device to the excavator.

16. An excavator comprising an attachment (10) according to claim 15, wherein: The attachment is provided with a power connection, such as a fluid connection (41), to a power system, such as a fluid system, of the small excavator for providing power to the drive mechanism.

17. A method for directional drilling in the earth, the method comprising the steps of: Providing a drill string (90) in a directional drilling device (1), for example, wherein the length of the drill string is greater than the length of the directional drilling device; Positioning the device so that the drilling direction (d) reaches the surface at a desired angle (α) relative to the horizontal, for example at an angle of -45° to 45°, such as -30° to 30°; Clamping the drill string with a first clamping device (31) and moving the first clamping device parallel to the longitudinal drilling axis (A) away from an initial position to advance the drill string into the ground (97); Release the first clamping device (31) and clamp the drill string with the second clamping device (32); moving the second gripping device parallel to the drilling axis to further advance the drill string into the ground; while advancing the drill string (90) using the first gripping device and / or the second gripping device, rotating the drill string about the drilling axis to advance the drill string along a straight path, and maintaining the drill string in a fixed rotational position to advance the drill string along a curved path corresponding to the fixed rotational position; and while the drill string is advanced by the second clamping device, the first clamping device is moved back to the initial position, or vice versa, while the drill string is advanced by the first clamping device, the second clamping device is moved back to the initial position, or the first clamping device and the second clamping device are moved together in the drilling direction in the clamped state.

18. The method according to claim 17, wherein: Before drilling, the length of the drill string is greater than the length of the directional drilling device.

19. The method according to claim 18, wherein: Prior to drilling, the length of the drill string is the entire intended length of the borehole to be drilled in the ground.

20. The method according to any one of claims 17 to 19, further comprising the steps of: Before drilling, dig the starting pit and / or exit pit using tools such as a small excavator; Optionally, removing an excavating device, such as an excavator bucket, from the tool; Attaching a directional drilling device to the tool; • Using the directional drilling device attached to the tool, the step of advancing the drill string from the starting pit and / or towards the exit pit using the directional drilling device is performed.

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