EP2141285A1 - Drilling and mixing tool - Google Patents

Abstract

The tool (1) has a central part (3) including a rotational axis, and foldable cutters (4-1, 4-2) arranged in the central part. The foldable cutters are movable between expanded and retracted positions along a vertical folding axis. A discharge nozzle (6) is arranged in the tool and supplied with a fluidic medium using a rotatably driven drilling rod. The foldable cutters are arranged along the central part in different planes and connected with the central part using a vertically oriented bolt (8).

Description

The invention relates to a drilling and mixing tool, in particular for connection to a rotationally drivable drill string and a drill bit, wherein the drilling and mixing tool comprises a central part and at least two individual arranged on the central part folding blades, wherein the folding blades each between an unfolded position and a beige-folded position are movable, and wherein outlet nozzles are provided on the drilling and mixing tool, which are supplied via the drill pipe with liquid medium.

Such tools are used for methods for producing soil bodies, in particular for the production of re-foundations of foundations, which are regulated as 'depth Bodenvermörtelung' in DIN EN 14679 (2005-07) and also referred to as 'Deep Soil Mixing' (DSM) and in which the foundation or an upper soil layer is passed through in a borehole with a smaller diameter borehole and then below a foundation a cylindrical foundation body is produced with a second larger diameter by the resulting soil is mixed with a suspension of water and cement , When driving through the well, the folding cutters are folded in, so that the tool has a total outer diameter in the folded-in state, which is not greater than the diameter of the drill bit or the borehole diameter. For Bodenvermörtelung the folding cutters are then unfolded below the foundation plate to a total outer diameter, which is greater than the borehole diameter.

From the DE 10 2004 038 896 A1 Such a drilling and mixing tool is known. The tool comprises a central part and at least two hinged on the central part folding cutters. The folding cutters are infinitely pivotable on transverse axes arranged transversely to the longitudinal axis of the drill string. The control of the folding cutters is done for all folding cutters by means of a complex operating mechanism.

The DE 24 22 489 A1 discloses a soil auger with a drill shank. On the drill shank a hub is provided, are mounted on the pivotable rotary blades. The pivoting of the rotary blade via a reversal of the direction of rotation of the drill shank. The rotary blades are arranged in a common plane.

It is an object of the invention to provide an improved drilling and mixing tool of the type mentioned.

This object is achieved by a drilling and mixing tool, in particular for connection to a rotary drivable drill string and a drill bit, wherein the drilling and mixing tool comprises at least one central part with a rotation axis A and at least two individual arranged on the at least one central part folding blades, wherein the folding cutters are each movable between a folded position and a deployed position, and wherein outlet nozzles are provided on the drilling and mixing tool, which can be supplied via the drill string with liquid medium, which is characterized in that the folding blades along the at least one central part are arranged in different levels.

The drilling and mixing tool according to the invention advantageously allows for foundation of foundations, whereby it is particularly suitable for use in confined spaces, as they are encountered in particular in railway construction, if a subsoil improvement to existing track bodies should be made. In this case, the drilling and mixing tool driven by the drill string rotates through with folded flap cutters in the region of a bottleneck, for example between existing railway sleepers, the upper soil layer.

Below the upper soil layer, the direction of rotation of the drilling and mixing tool is reversed, whereby an unfolding of the folding blades is done automatically by the resistance of the folding blades in the ground. By re-reversing the direction of rotation of the drilling and mixing tool, the folding cutters are automatically hooked, so that the tool can be moved out through the bottleneck from the ground. The drilling and mixing tool has a simple mechanism, since it has only two joints and no additional drive or a lock for the folding blades, so that a low susceptibility to fouling is ensured. The central part of the drilling and mixing tool is designed to be robust, guides the binder unhindered in its interior and can be advantageously connected to other central parts, so that the length of the tool is variable overall.

Due to the arrangement of the folding cutters in different levels, the folding cutters can act independently of each other. In concrete terms, this means, for example, that no material is pressed by the one folding blade against the other, which otherwise can lead to problems especially when folding or folding the folding cutters.

By different levels is meant that at least in the unfolded state, the lower edge of a folding blade is arranged in the vertical direction above the upper edge of the next lower flap cutting edge. However, parts of the folding mechanism, which are firmly connected to the central part, can protrude into the plane of the respective other folding mechanism. The vertical direction is always the direction of the axis of rotation of the drill string, regardless of whether the drill string actually protrudes vertically into the ground.

Preferably, the folding cutters are each movable about a vertical folding axis between the unfolded position and the folded-in position. The automatic folding and folding of the folding blades is effected by reversing the direction of rotation of the drilling and mixing tool. The folding trimmers are automatically unfolded when the tool moves in a direction of rotation, since the outer areas of the folding trimmers wedge into the surrounding soil and the earth pressure against the folding blades acts. In the other direction of rotation, the surrounding soil slows down the folding cutters, resulting in the automatic folding of the folding cutters. It is advantageous that the force required for unfolding or folding the folding cutters is generated solely by the resistance of the soil against the rotation of the drilling and mixing tool. This results in a folding out of the folding cutters, when the rotation of the drilling and mixing tool takes place in a first direction of rotation and a folding of the folding cutters in the corresponding opposite direction of rotation.

Together with the arrangement of the folding cutters in different levels, each automatically hinged folding edge has more space for folding in its own plane. This increases the ratio of the overall outer diameter of the tool when the folding cutters are deployed to the overall outer diameter of the tool when the folding cutters are folded in. This means that now compared to conventional folding cutters larger folding cutters can be folded in a relatively small space, thereby allowing a passage through a well with a relatively small hole diameter is made possible.

Preferably, the folding cutters are connected by means of a vertically arranged bolt with the central part. Advantageously, this results in a robust and few components comprehensive storage of the folding blades on the central part. Since it is assumed here of quasi-static movements, can be advantageous to dispense with the use of special plain bearings here, which in particular guarantees a low susceptibility to contamination of this bearing, so that the folding movement of the folding cutters works safely even with heavy contamination.

In order that each unfolded folding blade is held securely in a defined position relative to the central part of the drilling and mixing tool, each of the folding cutters has at least one contact surface, which is supported on at least one supporting surface of the at least one central part, in addition to the sole bearing. The advantage here is that the contact surfaces and support surfaces can be easily produced by known manufacturing processes and no further components are required for the locking of the folding blades, so that the folding cutting mechanism overall a simple mechanism is based.

The simple mechanical construction of the folding cutters is continued in that the folding cutters each comprise an engagement surface and a radially outwardly disposed wear plate.

Preferably, during the drilling operation, the drilling and mixing tool is supplied with binder mixture, which is treated by an external mixing station, via a hose line via compressed air or with pumps. The binder is introduced via a rotary union, called swivel, into the interior of the drill pipe. The drilling operation can be carried out either by a dry mixing method or by a wet mixing method. In the dry mixing process, the binder is usually a mixture of cement and lime or a combination of cement, lime, gypsum, blast furnace slag or pulverized fly ash. Compressed air is used to introduce the binder into the soil. In the wet mixing process, the binder is usually a cement suspension and it is fed via pumps. If necessary, sand or other additives are added.

The binder supplied to the drilling and mixing tool and optionally also rinsing liquid is advantageously fed to the outlet nozzles in the interior of the central part via at least one channel extending in the interior in the direction of the axis of rotation A, short channels extending radially outward from the at least one channel to each outlet nozzle , The outlet nozzles are used to supply binder in the soil and optionally the application of rinsing fluid to the folding cutters and the folding mechanism.

The outlet nozzles comprise at least binder nozzles. The binder nozzles are used to supply the binder into the soil.

Preferably, at least one binder nozzle is arranged above the uppermost folding edge. While the tool is moved upwards, this is done with the application of the liquid material in an untreated soil layer, the then edited by the tool.

Preferably, at least one binder nozzle is arranged below the lowermost flap cutting edge. During the delivery of the binder, while the tool is being moved down, the application of the liquid material takes place in an untreated soil layer, which is subsequently processed by the tool.

In a preferred embodiment, at least one of the binder nozzles is approximately radially outward. Alternatively or in combination therewith, when circumstances require, individual binder nozzles may be directed approximately obliquely downward or approximately vertically downward.

The outlet nozzles preferably also include rinsing nozzles, which are respectively directed to one of the folding cutters. The rinsing nozzles serve to clean the folding cutters before, during and / or after the mortar. The folding cutters or other parts of the tool can be flushed free of material, whereby the folding function of the folding cutters always remains ensured.

Preferably, the rinsing nozzles are each directed to one of the folding cutters in their folded-in position. As a result, in particular dirt, which has accumulated during the mortar in unfolded folding cutters in the vicinity of the central part and could complicate a clipping of the folding cutters, be washed away. As a result, a rapid Beiklappen the folding cutters is achieved, which also favors a speedy retraction of the entire assembly from the well.

In this case, at least one of the flushing nozzles is arranged above one of the folding cutters and in particular points vertically downwards. Alternatively or in combination, at least one of the flushing nozzles is arranged below one of the folding cutters and in particular points vertically upwards.

Preferably, the drilling and mixing tool after it has been drilled with folded folding cutters through the constriction and the direction of rotation is reversed was, with completely unfolded folding blades and with the desired speed in the soil drilled to a specified depth. Then the drilling and mixing tool is drilled upwards while maintaining the speed and direction of rotation. The beginning of the binder feed can, depending on requirements, commence immediately after the folding cutters are unfolded below the bottleneck or upon reaching the final depth, ie during the drilling.

Preferably, the binder is supplied via the outlet nozzles, which are considered in the drilling direction or feed direction, are located in front of the folding cutters, so that when drilling the binder supply via the lower outlet nozzles and during drilling over the upper outlet nozzles. It is advantageous here that, regardless of whether a binder agent is supplied during drilling or drilling, always optimal mixing of the binder is ensured with the soil. For a better mixing of the soil with binder, an existing drilling hole can be passed through several more times.

If the unfolded folding cutters of the drilling and mixing tool during drilling are about short of the bottleneck, again reverses the direction of rotation, so that the folding blades automatically wobble. To assist the lapping operation, the exit nozzles may advantageously be provided with a rinsing liquid, e.g. Water, to be rinsed. As a result, in particular the discharge nozzles directed vertically onto the folding cutters in the folded-in position ensure that soil residues are washed away between the contact surfaces of the folding cutters and the support surfaces of the central part. These outlet nozzles serve advantageously as flushing nozzles for cleaning in particular of the folding mechanism, so that the folding function of the folding cutters always remains ensured.

In the applications in which certain outlet nozzles are not used, it is provided that they are covered by screw plugs.

The maximum diameter of the drilling and mixing tool is about 300mm to 310mm when the flapper blades are folded (core bore diameter) and about 800mm when the flapper blades are deployed that cylindrical foundation body can be produced with about 800mm diameter, with larger Kembohrungsdurchmessern also larger diameter of the foundation body can be realized.

The drilling and mixing tool can be advantageously carried out in different lengths. In this case, the drilling and mixing tool has at least one central part, at the first end connecting means with an integrated medium feedthrough, preferably a hexagonal connector, are provided and with which the connection to the drill pipe is made. The shortest embodiment of the drilling and mixing tool provides for the second end of this central part connecting means, preferably a hex connector, with which the connection with the drill bit is made. Thus, this shortest embodiment comprises exactly one central part.

The extended embodiments provide for the second end of the first central part connecting means with an integrated medium feedthrough, preferably a hexagonal connector, which are compatible with connection means with integrated medium feedthrough of a second and another, connected thereto central part, which preferably have a hexagonal connector as connecting means ,

By means of this alternating sequence of the compatible connecting means with integrated medium leadthrough, advantageously several central parts can be connected to one another, wherein the last connected central part carries at its second end the drill bit via the preferred hexagonal connector. Advantageously, it follows that the length of the drilling and mixing tool can be adapted to the required drilling depth, the length of the drilling and mixing tool in its shortest execution with a central part without drill bit is about 1000mm.

The connection of the drill bit, which is designed for example as a wing chisel, advantageously facilitates the drilling of the drilling and mixing tool into the soil, wherein the diameter of the drill bit is preferably about 250 mm, which advantageously results in that the folding blades protrude radially beyond the drill bit and a have sufficient free attack surface, with which they come into contact with un-loosened soil.

The drill bit is secured to the hex connector via a central screw and the hex connectors at the connection between two central parts or between the drill string and the first central part are each secured by two dowel pins.

As a connecting means, in addition to or instead of the hexagonal connector, other positive connection means for torque-transmitting connection of the drill string and the drill bit can be provided.

Preferably, the first central part is connected to the drill pipe via a medium-carrying connecting piece, which is connected via connecting means with integrated medium feedthrough to the central part. The connecting means preferably have a hexagonal connector. The fitting is connected to the drill pipe. For this purpose, different types of connection can be provided depending on the drill string used and the drill rod driving power rotary head. Preferably, the connection via a zweigängiges, conical round thread with clamp protection. The clamping protection advantageously ensures that the drilling and mixing tool can rotate in both directions while the connection is permanently secured.

Preferably, the central part is aligned coaxially with the drill pipe.

Figur 1

ein erfindungsgemäßes Bohr- und Mischwerkzeug a) von unten betrachtet, b) von der Seite betrachtet, c) von oben betrachtet;

Figur 2

einen Schnitt durch das Werkzeug gemäß Figur 1 a) bei ausgeklappter Klappschneide entlang der Linie II - II, b) bei beigeklappter Klappschneide entlang der Linie I - I;

Figur 3

das Werkzeug nach Figur 1 in perspektivischer Darstellung: mit einer Klappschneide im beigeklappten, und einer Klappschneide im ausgeklappten Zustand.

A preferred embodiment of the invention is shown in the following figures. Herein shows

FIG. 1

an inventive drilling and mixing tool a) viewed from below, b) viewed from the side, c) viewed from above;

FIG. 2

a section through the tool according to FIG. 1 a) with unfolded folding edge along the line II - II, b) with folded folding edge along the line I - I;

FIG. 3

the tool after FIG. 1 in perspective view: with a folding edge in the beige-folded, and a folding blade in the unfolded state.

The FIGS. 1 to 3 will be described together below.

It can be seen the lower end of a drill string 2, to which a drilling and mixing tool 1 is connected to a rotation axis A, at the top a connector 22 ₁ for connecting the drill string 2 and below a connector 22 _{2 is provided} for connecting the drill bit , The drilling and mixing tool 1 is hereinafter referred to as tool 1.

The connector 22 ₁ is preferably designed as a hexagonal connector with integrated medium feedthrough. The connector 22 ₂ is preferably designed as a hexagonal connector.

At the central part 3, two folding cutters 4 ₁ , 4 _{2 are} movably mounted via a respective bearing device 10. The folding cutters 4 ₁ , 4 ₂ and the bearings 10 are designed identically, so that the following statements apply in principle for both storage facilities and folding cutters.

The figures show the tool 1 in its entirety, each with a folded folding blade 4 ₁ and an unfolded folding blade 4 _second This representation is only for better understanding. In normal operation, the tool 1 will normally not be in the illustrated state with a collapsed and an unfolded folding edge, since the folding cutters usually each jointly unfold or whip, since the tool 1 with two folded folding blades 4 ₁ , 4 ₂ in the Soil is drilled and due to a reversal of rotation both folding blades 4 ₁ , 4 ₂ expand simultaneously, since both are acted upon equally by the resistance of the soil against the rotation of the tool 1, so that it can be dispensed with an additional adjustment of the folding blades 4 ₁ , 4 ₂ .

The bearings 10 each have a fork-shaped stud holder 11, which is welded to the central part 3. The stud holder 11 has two fork arms 12, each with a bore 13. The bores 13 of the fork arms 12 of the stud holder 11 have identical axes, are defined by the respective folding axes B of the folding blades 4 ₁ , 4 ₂ . In the two holes 13 of a stud holder 11, a bolt 8 is held together, which in turn is inserted into a bore 9 of the folding blades 4 ₁ , 4 ₂ . The folding cutters 4 ₁ , 4 ₂ are each arranged between the fork arms 12 of the stud holder 11. By Bolzenlagerüng results in a robust and little components comprehensive storage of the folding blades 4 ₁ , 4 ₂ on the central part 3, which in particular guarantees a low susceptibility to contamination of these bearings. The bolt is secured with a pin fuse 23 against falling out.

Each of the folding blade 4 ₁ , 4 ₂ has a lever arm 14, at the radially outermost end of a wear plate 15 is attached. The wear plate 15 is mounted on the lever arm 14 via suitable fastening means and can be dismantled for renewal.

In the folded-in state, the lever arm 14 bears with a first stop 16 on a first counter-stop 17 of the stud holder 11, as shown in FIG FIG. 2b can be seen. In the unfolded state, the lever arm 14 is located with a second stop 18 on a second counter-stop 19 of the stud holder 11, as in FIG. 2a can be seen. By the counterstops 17, 19 results in an advantageous that the tool 1 no additional locks for the positioning of the folding blades 4 ₁ , 4 ₂ needed.

From the Figures 1b . 2 and 3 It can be seen that the folding blades 4 ₁ , 4 ₂ are arranged in different planes. In this case, a lower edge 20 of the upper flap cutting edge 4 ₁ above an upper edge 21 of the lower flap cutting edge 4 _{2 is} arranged. In addition, in this embodiment, the bearings are arranged completely in different levels. By this arrangement it is ensured that the material which moves each flap cutting edge 4 ₁ , 4 _{2 in} front of him, not pressed against the respective other folding blade 4 ₂ , 4 ₁ .

The central part 3 has two radial recesses 7 ₁ , 7 ₂ . The radial recesses in each case form a receiving space for one of the folding cutters 4 ₁ , 4 ₂ . As a result, in combination with the vertical offset of the folding cutters 4 ₁ , 4 _2, the radial dimensions of the tool in the folded-in state of the folding cutters are kept as small as possible.

Over the interior of the central part 3 at least one extending in the direction of the axis of rotation A channel (not shown) at least binder and optionally rinsing liquid to four outlet nozzles 5, 6 of the tool 1 out. The outlet nozzles 5, 6 are arranged on the circumference of the tool 1, wherein two outlet nozzles can be used by their vertical orientation primarily as rinsing nozzles 5 ₁ , 5 ₂ and two outlet nozzles are used by their horizontal alignment as binder nozzles 6 ₁ , 6 ₂ . It can be provided that all four outlet nozzles 5, 6 can be supplied simultaneously with each binder or rinsing liquid. However, it is also conceivable that for the rinsing nozzles 5 ₁ , 5 ₂ and for the binder nozzles 6 ₁ , 6 ₂ separate channels are provided, so that in each case, if necessary, the binder nozzles 6 ₁ , 6 ₂ with binder and the rinsing nozzles 5 ₁ , 5 _second can be supplied with rinsing liquid.

The binder nozzles 6 ₁ , 6 ₂ point radially outward. The uppermost binding agent nozzle 6 ₁ is arranged above the upper folding blade 4 ₁ . The lowermost binder nozzle 6 ₂ is arranged below the lower flap cutting edge 4 ₂ .

In the upper region of the upper radial recesses 7 ₁ , a first rinsing nozzle 5 _{1 is} mounted, which points approximately vertically downwards. The first rinsing nozzle 5 ₁ is directed to the upper folding edge 4 ₁ approximately vertically downwards, when this is in its folded position. In FIG. 1b Although the first rinsing nozzle 5 ₁ is visibly displayed, which serves only for better understanding. Actually, the first one is Flush nozzle 5 ₁ but not visible on the back of the central part 3 is arranged.

In the lower region of the lower radial recesses 7 ₂ , a second rinsing nozzle 5 _{2 is} mounted, which points approximately vertically upwards. The second rinsing nozzle 5 ₂ is directed to the lower folding edge 4 ₂ , when this is in its folded position. In particular, the vertical on the folding cutters 4 ₁ , 4 ₂ in beigeklappter position directed upper and lower flushing nozzles 5 ₁ , 5 ₂ ensure that during the lapping of the folding blades 4 ₁ , 4 ₂ earth residues between the stops 16, 17 are washed away, so that advantageous cleaning in particular of the folding mechanism takes place and the folding function of the folding blades 4 ₁ , 4 ₂ always remains ensured. Alternatively it can be provided that the second rinsing nozzle 5 _{2 is arranged} in the upper region of the lower recesses 7 ₂ and approximately vertically downwards or that in the upper region of the lower recesses 7 ₂ additionally a third rinsing nozzle (not shown) is arranged and perpendicular to points down.

The drilling and mixing tool 1 according to the invention advantageously allows a foundation of foundations, whereby it is particularly suitable for use in confined spaces. The unfolding and whipping of the folding blades 4 ₁ , 4 ₂ is carried out automatically as a result of reversal of rotation of the drilling and mixing: convincing 1 by the resistance of the folding blades 4 ₁ , 4 ₂ in the ground, without separate adjustment drives are required. The drilling and mixing tool 1 has a simple mechanism, since each of the folding blades 4 ₁ , 4 _{2 is held} only by a bolt 8 in a bearing 10 and no additional locking mechanism for the folding blades 4 ₁ , 4 ₂ has, so that a small Pollution susceptibility is ensured.

LIST OF REFERENCE NUMBERS

1

Drilling and mixing tool

2

drill pipe

3

Central part

4

folding cutting

5

exhaust nozzle

5 ₁ , 5 ₂

rinsing nozzle

6

exhaust nozzle

6 ₁ , 6 ₂

binder nozzle

7

recess

8th

bolt

9

drilling

10

Storage facility

11

Bolzenhalter

12

fork arm

13

drilling

14

lever arm

15

wear plate

16

first stop

17

first counter-attack

18

second stop

19

second counter-attack

20

lower edge

21

top edge

22 ₁ , 22 ₂

Interconnects

23

pin safety

A

axis of rotation

B

folding axis

Claims (15)

Drilling and mixing tool (1), in particular for connection to a rotationally drivable drill string (2) and a drill bit, wherein the drilling and mixing tool (1) at least one central part (3) with a rotation axis A and at least two individual on the at least one Central part (3) arranged folding cutters (4),
wherein the folding cutters (4) are each movable between an unfolded position and a folded-in position,
and wherein outlet nozzles (5, 6) are provided on the drilling and mixing tool (1), which can be supplied with liquid medium via the drill pipe (2),
characterized,
that the folding blades (4) along the at least one central part (3) are arranged in different planes. Drilling and mixing tool according to claim 1,
characterized,
that the tiltable cutters (4) each along a vertical folding axis (B) are movable between the extended position and the collapsed position. Drilling and mixing tool according to one of claims 1 or 2,
characterized,
that the tiltable cutters (4) each by means of a vertically arranged bolt (8) are connected to the central part (3). Drilling and mixing tool according to one of claims 1 to 3,
characterized,
in that the outlet nozzles comprise binder nozzles (6). Drilling and mixing tool according to claim 4,
characterized,
in that at least one of the binder nozzle (6 ₁ ) is arranged above the uppermost folding blade (4 ₁ ). Drilling and mixing tool according to one of claims 4 or 5,
characterized,
in that at least one binder nozzle (6 ₂ ) is arranged below the lowermost flap cutting edge (4 ₂ ). Drilling and mixing tool according to one of claims 4 to 6,
characterized,
in that at least one of the binder nozzles (6) points approximately radially outward. Drilling and mixing tool according to one of claims 4 to 7,
characterized,
in that at least one of the binder nozzles (6) points approximately obliquely downwards. Drilling and mixing tool according to one of claims 4 to 8,
characterized,
in that at least one of the binder nozzles (6) points approximately vertically downwards. Drilling and mixing tool according to one of claims 1 to 9,
characterized,
in that discharge nozzles comprise rinsing nozzles (5) which are respectively directed onto one of the folding cutters (4). Drilling and mixing tool according to one of claims 1 to 10,
characterized,
that the rinsing nozzles (5) are each directed to one of the folding cutters (4) in their folded-in position. Drilling and mixing tool according to one of claims 1 to 11,
characterized,
in that at least one of the rinsing nozzles (5 ₂ ) is arranged below one of the folding cutters (4 ₂ ) and points vertically upwards. Drilling and mixing tool according to one of claims 1 to 12,
characterized,
in that at least one of the rinsing nozzles (5 ₁ ) is arranged above one of the folding cutters (4 ₁ ) and points vertically downwards. Drilling and mixing tool according to one of claims 1 to 14,
characterized,
in that the liquid medium in the interior of the at least one central part (3) is led via at least one channel to at least one of the outlet nozzles (6). Drilling and mixing tool according to one of claims 1 to 13,
characterized,
in that the at least one central part (3) is aligned coaxially with the drill pipe (2).

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