EP2770157A1 - Drilling tool and method for drilling in soil - Google Patents

Abstract

The drilling tool has a drill rod element (14) connected to a rotary drive and driven in a rotating manner about a drilling axis (7). A removal tooth (26) is supported in a radially adjustable manner in a frame-like housing (12) between a retracted position in the housing and an operating position in which the removal tooth projects radially from the housing. A transmission mechanism (30) is arranged on the drill rod element in the housing, so as to translate a stroke and/or rotational movement of the drill rod element into a radial movement for radial adjustment of the removal tooth. An independent claim is also included for a method for producing a bore in the ground.

Description

The invention relates to a drilling tool for Erdbohren with a drill string element which is connectable to a rotary drive and rotatably driven about a drilling axis, a frame-like housing and at least one Abtragszahn which is mounted radially adjustable in the housing between a retreat position in the housing and a working position in which the at least one removal tooth protrudes radially out of the housing, according to the preamble of claim 1.

The invention further relates to a method for producing a bore in the ground with such a drilling tool.

Drilling tools for earth drilling are used in particular for the creation of foundation piles for buildings. In this case, a drilling tool is rotationally introduced into the soil by means of a drill with a rotary drilling drive, wherein soil material is removed and conveyed away to the ground surface. As a result, a bore is created which has a substantially uniform bore diameter over the entire bore depth.

For certain applications, however, it is desirable or necessary to extend the bore diameter in a lower region of the bore. For this purpose, for example, a generic drilling tool can be used, which from the DE 32 19 362 C1 is known. In this known drilling tool can be adjusted by means of a hydraulic cylinder Abtragszahn on a housing-like body from a retreat position into a radially projecting working position. In this projecting removal position, an enlarged bore diameter can be achieved with an adjustment in the borehole.

After performing the Bohrdurchmessererweiterung the erosion tooth can be reset by the hydraulic cylinder, so that the drilling tool can be withdrawn through the upper hole area with smaller bore diameter again.

However, with rotationally driven drilling tools with a drill string, a supply of hydraulic fluid to the drilling tool is problematic. Thus, the supply of hydraulic fluid from outside the borehole to a rotating drilling tool necessarily requires a so-called rotary feedthrough in which a rotating connection part is to be sealed against high pressure against a stationary connection part. The leadership and arrangement of the hydraulic lines in the hole is prone to failure. For solid hydraulic lines along the drill string additional seals must be provided if additional drill string elements must be used to accommodate larger drilling depths. An alternative supply of hydraulic fluid via a flexible hose is susceptible to damage in harsh site conditions and also requires a separate hose feed with hose reel.

The invention has for its object to provide a drilling tool and a method for earth drilling, with which an extension of the drill diameter in a lower region of the well is made possible in a simple and reliable manner.

The object is achieved on the one hand with a drilling tool having the features of claim 1 and on the other hand by a method having the features of claim 10. Preferred embodiments of the invention are specified in the respective dependent claims.

The drilling tool according to the invention is characterized in that in the drill pipe element in the housing, a transmission mechanism is arranged, by which a lifting movement or a lifting and rotating movement of the drill string element in a radial movement for radially adjusting the at least one Abtragszahnes is translatable.

A basic idea of the invention is the necessary energy for actuating an adjustable erosion tooth on the drilling tool via a normal stroke. and / or to apply rotary motion of the drill string. It can therefore be dispensed with hydraulic or electrical actuators and corresponding feeds for hydraulic fluid or electricity. For this purpose, a transmission mechanism is arranged in the housing of the drilling tool, can be picked up by which a lifting or rotary movement of the drill string element and translated into a desired radial movement of the at least one Abtragszahnes. It is thus provided a mechanical actuating mechanism, which is actuated directly by the drill pipe and its movements. The drill pipe serves in a known manner for transmitting an axial feed movement during drilling and for transmitting the Bohrdrehmomentes of a rotary drilling drive, which is arranged on the ground surface. Preferably, a rotary drilling machine is provided with a vertical mast on which in known manner the drilling drive is mounted so as to be displaceable vertically displaceably on a drilling carriage.

The purely mechanical solution for the radial adjustment of erosion teeth on the drilling tool is robust, low maintenance and therefore less susceptible to interference.

A preferred embodiment of the drilling tool according to the invention is that the transmission mechanism has a sliding sleeve, which is mounted axially displaceable along the drilling axis, that at least one radially adjustable mounted in the housing sliding member is arranged on which at least one Abtragszahn is attached, and that at least a deflection lever is articulated on the one hand to the sliding sleeve and on the other hand to the sliding member, wherein an axial lifting movement of the sliding sleeve in a radial adjusting movement of the sliding member can be implemented by the deflection lever. The sliding sleeve is preferably mounted axially displaceable concentrically with the drilling axis on the drill string element or as part of the drill string element of the drilling tool.

The axial displacement movement can preferably be applied by the drilling tool being placed on the bottom of the hole and the sliding sleeve being displaced axially by a predetermined distance due to the pressure exerted from above. This thrust movement, which is parallel to the drilling axis, causes a radial adjusting movement of a sliding element, which is guided radially adjustable in the housing, via radially directed, inclined deflection levers. The sliding member serves as a carrier for receiving and holding one or more erosion teeth.

The drilling tool according to the invention is advantageously further developed in that on an upper side an upper connection for a drill pipe and that on a lower side a lower connection for a removal device for the removal of soil at the bottom of the hole is provided. The drilling tool according to the invention can therefore be as an intermediate or insert member of a larger drilling tool unit. Thus, as a removal device, for example, a radially directed drill bit or, preferably, a drill bit for a discontinuous Kellybohren be provided. At the top, an upper port is preferably formed as a so-called Kellybox with a square opening. It can be made as a connection to a conventional drill pipe, in particular a telescopic Kelly rod.

A further advantageous embodiment variant of the drilling tool according to the invention is that the upper connection to the lower terminal via a Befestigungselemet rotatably and axially slidably connected to a predetermined stroke and that the axial stroke is limited by means of the sliding sleeve. The housing extending drill pipe element is thus not rigid, but at least formed in two parts. Between the two parts, a coupling member may be provided, which allows a rotationally fixed connection, but a relative to the drilling axis axial movement. For this purpose, for example, be provided a keyway, which is provided on the inner or an outer side of the Befestigungselemetes as a coupling member. The axial Stelloder stroke is limited by mechanical stops.

An alternative embodiment variant of the drilling tool according to the invention can be seen in that the transmission mechanism has a rotary member which is rotatably mounted about the drilling axis, that at least one pivotally mounted on the housing pivot member is arranged on which at least one Abtragszahn is mounted, and that at least one Pivot lever is hinged on the one hand to the rotary member and on the other hand on the pivot member, wherein a rotational movement of the rotary member can be converted into a radial adjusting movement of the pivot member by the pivot lever. By this arrangement with a rotary member, a rotational movement of the drill string can be translated into a desired radial displacement movement of the Abtragszahnes.

Similar to the previously described sliding sleeve while the rotational movement of the rotary member can be limited by appropriate stops to a predetermined angle of rotation. It is also the upper port relative to the lower port rotatably mounted by an angular amount.

An advantageous development of this arrangement consists according to the invention in that the rotary member between a first rotational position, in which the at least one Abtragszahn is in the retracted position in the housing, and a second rotational position is rotatable, wherein the Abtragszahn in the working position radially located outside the housing, and that the rotary member in the first rotational position and / or the second rotational position is lockable. A locking or unlocking can be done via a Verbolzung from outside the borehole. Preferably, however, a locking or unlocking can take place by an axial adjusting movement of the drill string, as is known, for example, in the locking or unlocking of a telescoping Kellybohrgetänges. For this purpose, corresponding axial latch pockets can be provided on the linkage element of the drilling tool.

According to another embodiment of the invention, it is advantageous that at the bottom of a removal device for removing soil is connected to the bottom of the hole. The removal device may in particular be a drilling screw. But there are also other removal device, such as a drilling bucket conceivable.

Further, it is preferred according to the invention that the removal device is designed as a drilling screw with at least one drill spiral. However, in particular in the area of the lower boring cutting edge, two or more boring spirals can also be arranged.

Especially with longer augers, it is advantageous according to the invention that at least one folding tooth is arranged on the auger in a lower region, which can be folded in pending ground from a retracted retraction position into a radially projecting removal position. Preferably, two or more folding teeth are pivotally mounted at the lower end of the auger. The arrangement is preferably chosen so that in an unloaded state, the folding teeth are in the retracted retraction position and not radially protrude towards the drill helices. By placing on the bottom of the hole and the pending pressure of the drilling tool, the folding teeth can then expand into their removal position in which they project radially relative to the drill helices. Preferably, the folding teeth on the auger in the removal position are just as far radially as the erosion teeth of the drilling tool in the radially expanded working position.

The inventive method for producing a hole in the ground is characterized in that at least temporarily soil is removed with a drilling tool, which was previously described. A drilling tool unit can be of modular design, wherein the drilling tool according to the invention is a modular member, which is mounted only at certain working sections in the preparation of the borehole to the drill string.

A particularly preferred variant of the method according to the invention is that first a cased bore is produced with a support tube having an inner diameter and an outer diameter up to a first drilling depth, that a connection bore is continued below the support tube to a second drilling depth, wherein the connection bore a Drill diameter which corresponds to the inner diameter of the support tube, and that the bore diameter of the connection bore is extended at least in a partial area with the drilling tool according to the invention to a bore diameter which is equal to or greater than the outer diameter of the support tube.

With this method, a uniform drill or foundation pile can be created with a constant bore diameter, which is provided in its upper region to stabilize the well with a drill or support tube. In this case, this metal support tube usually extends only a few meters into the ground. The support or drill pipe is usually introduced in addition to the drilling tool in the ground. In conventional drilling then there is the problem that the bore is limited below the support tube to the inner diameter of the support tube. With the drilling tool according to the invention, it is now possible in a simple manner below the support tube by extending the radially adjustable Abtragszähne a connection bore below the support tube on from a first bore diameter corresponding to the inner diameter of the support tube to expand to a larger second bore diameter, in particular to the outer diameter of the support tube.

Fig. 1:

eine Seitenansicht eines erfindungsgemäßen Bohrwerkzeuges mit ausgefahrenen Klappzähnen;

Fig. 2:

eine Draufsicht von unten auf das Bohrwerkzeug von Fig. 1;

Fig. 3:

eine Seitenansicht des Bohrwerkzeuges von Fig. 1 mit eingezogenen Klappzähnen;

Fig. 4:

eine Draufsicht von unten auf das Bohrwerkzeug von Fig. 3;

Fig.5:

eine Seitenansicht zu einem erfindungsgemäßen Bohrwerkzeug mit Schiebeglied in eingefahrener Position;

Fig. 6:

eine Querschnittsansicht zu Fig. 5;

Fig. 7:

eine Seitenansicht des Bohrwerkzeuges von Fig. 5 mit ausgefahrenem Schiebeglied;

Fig. 8:

eine Querschnittsansicht zu Fig. 7;

Fig. 9:

eine perspektivische Ansicht des Bohrwerkzeuges mit Schiebeglied;

Figuren 10 bis 12:

Querschnittsansichten zu einem weiteren erfindungsgemäßen Bohrwerkzeug in verschiedenen radialen Ausfahrpositionen der Abtragszähne;

Fig. 13:

eine perspektivische Explosionsdarstellung zu dem Bohrwerkzeug von Figuren 10 bis 12, jedoch ohne Übertragungsmechanismus; und

Fig. 14:

eine zusammengebaute Darstellung des Bohrwerkzeuges von Fig. 13.

The invention will be further described by means of preferred embodiments, which are shown schematically in the accompanying drawings. In the drawings show:

Fig. 1:

a side view of a drilling tool according to the invention with extended folding teeth;

Fig. 2:

a top view from below of the drilling tool of Fig. 1 ;

3:

a side view of the drilling tool of Fig. 1 with retracted folding teeth;

4:

a top view from below of the drilling tool of Fig. 3 ;

Figure 5:

a side view of a drilling tool according to the invention with sliding member in the retracted position;

Fig. 6:

a cross-sectional view too Fig. 5 ;

Fig. 7:

a side view of the drilling tool of Fig. 5 with extended sliding member;

Fig. 8:

a cross-sectional view too Fig. 7 ;

Fig. 9:

a perspective view of the drilling tool with sliding member;

FIGS. 10 to 12:

Cross-sectional views of another drilling tool according to the invention in different radial extension positions of the Abtragszähne;

Fig. 13:

an exploded perspective view of the drilling tool of FIGS. 10 to 12 but without transmission mechanism; and

Fig. 14:

an assembled representation of the drilling tool of Fig. 13 ,

A basic structure of the drilling tool 10 according to the invention, which is part of a drilling tool unit 5, can FIGS. 1 to 4 be removed. The drilling tool 10 according to the invention has a frame-like, sleeve-shaped housing 12 whose outer diameter corresponds approximately to the drill diameter. The housing 12 has on its upper side a cover element 18 and on its underside a bottom element 16. In the peripheral wall of the cylindrical housing 12, two opposite passage openings 20 are arranged for Abtragszähne. The radially expository erosion teeth of the drilling tool 10 are in the FIGS. 1 and 3 for clarity not shown and will be explained later.

At the lower bottom element 16 of the drilling tool 10, a lower terminal 24 is arranged in the form of a square Kellyverbindung. At the lower connection 24, a removal device 50, which is designed as a drilling screw 52, is releasably attached to the drilling tool 10 for forming the boring unit 5.

The auger 52 has a coaxial with the drilling axis 7 extending drill shank 54, at the lower end of a so-called pilot 60 is arranged for centering. Over the length of the drill shank 54, a first drill helix 56 extends for the removal and picking up of removed soil material. In the lower region, a second drill spiral 58 extends through which a symmetrical removal of the soil material by means of arranged cutting teeth 62 is made possible. In the lower region of the first and second boring spirals 56, 58, respective folding teeth 64 are arranged, which are arranged on a folding tooth carrier 66 hinged around a pivot pin 86. The folding tooth carrier 66 is located between a retracted retraction position, which in Fig. 4 is shown, and an unfolded, radially projecting removal position pivotally, which in Fig. 2 is clear.

In the unloaded state, the folding tooth carrier 66 pivots downward in the retraction position according to Fig. 4 , With pending soil material of the folding tooth carrier 66 to broaden the diameter of the drill bit with respect to the diameter of the first drill 56 outward in the position according to Fig. 2 pressed. The folding teeth 64 thus also allow below the drilling tool 10 according to the invention a Bohrdurchmessererweiterung.

In the housing 12 according to FIGS. 1 and 3 can be used to form the drilling tool 10 according to the invention a removal device, which closer in connection with the FIGS. 5 to 9 is shown and described.

A first transmission mechanism 30 has a fastening element 32, which is mounted coaxially to the drilling axis 7 on a drill pipe element 14. The drill pipe element 14 has, as not shown in detail, a separate lower element and a separate, but rotatably but axially slidably connected thereto second upper drill pipe element 14 'on. Two diametrically opposite guide plates 35 are fastened to the fastening element 32, along which a respective plate-shaped sliding member 34 is mounted so as to be radially movable. For each slide member 34 are each two bearing levers 36 are arranged, which are articulated on the one hand on the fastening element 32 and the attached guide plate 35 and on the other hand articulated to the sliding member 34.

The retraction position of the sliding member 34, on the outside of a plurality of Abtragszähnen 26 are releasably secured, is in FIGS. 5 and 6 shown. In the direction of the lower terminal 24, an annular sliding sleeve 40 is provided, which is mounted coaxially to the drilling axis 7 on the drill pipe element 14 axially displaceable. By pushing down the upper connection 22 against the borehole bottom, the sliding sleeve 40 is pressed in the direction of the fastening element 32 by means of the borehole bottom. On the sliding sleeve lever 37 are hinged. These lever 37 and the bearing levers 36 are pivoted when pressed down to a shallower angular position, which in Fig. 7 is shown. As a result of this pivoting movement of the deflection lever 37, the sliding member 34 mounted in a radially displaceable manner is adjusted radially outward along the guide plate 35. As a result, the Abtragszähne 26 of a smaller first bore diameter, which is determined by the Abtragseinrichtung 50, radially outwardly from the only schematically in Fig. 5 indicated housing 12 adjusted, as in the FIGS. 7 and 8 is clarified. The axial stroke of the sliding sleeve 40 is limited by the lower portion of the fastener 32 ..

Another embodiment of a drilling tool 10 according to the invention with a second transmission mechanism 130 will be described below in connection with FIGS FIGS. 10 to 14 explained.

A second transmission mechanism 130 with a rotatable about the drilling axis 7 mounted rotary member 132 is in the various operating positions in the FIGS. 10 to 12 shown. At the lower terminal 24, a stop device with three evenly distributed around the circumference of stops 140 are arranged, which are formed segment-like. Corresponding thereto, an annular disk-shaped rotary member 132 is formed, which has three likewise offset by 120 ° to each other driver elements 133.

The rotary member 132 is rotatably connected to the upper terminal 22, as in particular from Fig. 13 can be seen. As a result, a drill pipe element is formed as a whole, which is connected in a rotationally fixed manner via the upper connection 22 to the overlying drill pipe so that a torque transmission via the driver elements 133 and the stops 140 can be transmitted to the drill pipe element 14, which is connected in a rotationally fixed manner to the lower connection 24 is. Internal keyway structures 139 serve essentially for axial guidance.

In order to form the second transmission mechanism 130, a respective deflection lever 136 is pivotably articulated to the three driver elements 133. The opposite free end of the Auslenkhebels 136 is pivotally connected to a pivot member 134, on which releasably Abtragszähne 26 are arranged. The pivot member 134 merges into a bearing lever 137, which is pivotally mounted on a bearing block 138 which is fixed to the inside of the sleeve-shaped housing 12.

In Fig. 10 the drilling tool 10 according to the invention is shown with the second transmission mechanism 130 in the retracted position, in which the Abtragszähne 26 are disposed within the housing 12. In this position, the driver elements 133 of the rotary member 132 are in the clockwise direction of the segment-shaped stops 140, which are rotatably connected to the housing 12 and the lower terminal 24.

By a rotation of the rotary member 132 in the counterclockwise direction, as in Fig. 11 1, rotary motion of the drill string is translated radially outward by the second transmission mechanism 130 into radial movement of the abrasive teeth 26. By the rotation of the rotary member 132, the lever 136 are pressed in a more radial position, as in Fig. 12 shown. As a result, the pivot member 134 is pushed with the bearing lever 137 radially outward, whereby the Abtragszähne 26 occur through a passage opening, not shown here in the housing 12 out of this radially outward into a working position, which in Fig. 12 is shown. By a reverse rotation, the Abtragszähne 26 can be retracted accordingly.

How out Fig. 13 can be seen, the cylindrical housing 12 in the illustrated drilling tool 10 according to the invention three through openings 20 along the peripheral wall of the housing 12 for the passage of the Abtragszähne 26. The respective abutment surfaces of the driver elements 133 of the rotary member 132 and the corresponding abutment surfaces of the stops 140 may be beveled, so that the rotary member 132 in an axially unloaded state, in which the drilling tool 10 is suspended freely about a drill pipe, from the axial engagement position, which in Fig. 14 is shown, relatively slips upwards by a predetermined axial stroke. It is also possible to mount the rotary member 132 relative to the housing 12 so that it remains in the axial engaged position even in an axially unloaded condition. In this way, the drilling tool 10 can be introduced approximately by an inserted support tube in an existing bore with a first diameter. If the drilling tool 10 then abuts against the bottom of the hole, the upper connection 22 and the lower connection 24 are pushed axially toward one another so that the rotary element 132 can reach the engagement position with the driver elements 133, which in FIG Fig. 14 is shown.

By transferring the Bohrdrehmomentomentes counterclockwise so the retracted Abtragszähne 26 according to Fig. 10 in the extended working position according to Fig. 12 to be turned around. In this way, an extension of the drill diameter corresponding to the outer diameter of the extended removal teeth 26 can now be performed approximately below a support tube.

After completion of the drilling and transmission of a Bohrdrehmomentomentes clockwise Abtragszähne 26 by the transmission mechanism 130 again from the working position in accordance with Fig. 12 in the retreat position according to Fig. 10 reset. When lifting the drilling tool 10, the lower terminal 24 is again axially removed from the upper terminal 22 due to the now acting weight force, wherein in the case of tapered entrainment elements 133 and inclined surfaces on the stops 140 by the driver elements 133 and the inclined surfaces on the stops 140th the erosion teeth 26 by the transmission mechanism 130 again from the working position according to Fig. 12 in the retreat position according to Fig. 10 be reset.

Claims (11)

Drilling tool for drilling with a drill string element (14) which can be connected to a rotary drive and is driven to rotate about a drilling axis (7), - A frame-like housing (12) and - At least one Abtragszahn (26) which is mounted radially adjustable in the housing (12) between a retracted position in the housing (12) and a working position in which the at least one Abtragszahn (26) radially from the housing (12), characterized ,
that on the drill string (14) in the housing (12), a transmission mechanism (30, 130) is arranged, through which a lifting movement of the drill string (14) is translatable in a radial movement for radial adjustment of at least one Abtragszahnes (26). Drilling tool according to claim 1,
characterized, - That the transmission mechanism (30) has a sliding sleeve (40) which is mounted axially displaceable along the drilling axis (7), - That at least one radially adjustable in the housing (12) mounted sliding member (34) is arranged, on which at least one Abtragszahn (26) is mounted, and - That at least one deflection lever (37) on the one hand on the sliding sleeve (40) and on the other hand on the sliding member (34) is articulated, wherein by the deflection lever (37) an axial lifting movement of the sliding sleeve (40) in a radial adjusting movement of the sliding member (34) is feasible. Drilling tool according to claim 1 or 2,
characterized ,
that a lower connection for a drill string and a lower surface (24) for a Abtragseinrichtung (50) for the removal of soil at the bottom of a hole provided on an upper surface of an upper connection (22). Drilling tool according to claim 3,
characterized ,
in that the upper connection (22) is non-rotatably connected with the lower connection (24) via a fastening element (32) and is displaceably connected axially by a predetermined stroke, and
that the axial stroke is limited by means of the sliding sleeve (40). Drilling tool according to claim 1 or 3,
characterized , - That the transmission mechanism (130) additionally comprises a rotary member (132) which is rotatably mounted about the drilling axis (7), - That at least one radially pivotally mounted on the housing (12) mounted pivot member (134) is arranged on which at least one Abtragszahn (26) is mounted, and - That at least one pivot lever (136) on the one hand on the rotary member (132) and on the other hand on the pivot member (134) is articulated, wherein by the pivot lever (136) a rotational movement of the rotary member (132) in a radial adjusting movement of the pivot member (134) can be implemented is. Drilling tool according to claim 5,
characterized, - That the rotary member (134) between a first rotational position in which the at least one Abtragszahn (26) is in the retracted position in the housing (26), and a second rotational position is rotatable, wherein the Abtragszahn (26) in the Working position is located radially outside the housing (26), and - That the rotary member (134) in the first rotational position and / or the second rotational position is lockable. Drilling tool according to one of claims 1 to 6,
characterized,
that at the bottom of a removal device (50) for removing soil is connected to the bottom of the hole. Drilling tool according to claim 7,
characterized,
that the Abtragseinrichtung (50) as an auger (52) with at least one drill helix (56, 58) is formed. Drilling tool according to claim 8,
characterized,
that at least one folding tooth (64) is arranged on the drilling screw (52) in a lower region, which can be folded out from a retracted retraction position into a radially protruding removal position when the bottom is in contact. Method of making a hole in the ground,
characterized,
that soil is at least temporarily removed with a drilling tool (10) according to one of claims 1 to 9. Method according to claim 10,
characterized, that first a cased bore is produced with a support tube having an inner diameter and an outer diameter up to a first drilling depth, - That a connection hole is continued below the support tube to a second drilling depth, wherein the connection bore has a bore diameter which corresponds to the inner diameter of the support tube, and - That the bore diameter of the connection bore is widened at least in a partial area with the drilling tool (10) according to one of claims 1 to 9 to a bore diameter which is equal to or greater than the outer diameter of the support tube.

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