EP2146046B1 - Drill head for a drilling device for creating drill holes in insufficiently stable foundation - Google Patents

Description

The present invention relates to a drill head for a drilling device for creating wells in unsustainable soil by displacing the soil material, which drill head can be placed on a drill pipe of the drilling device and forms with the drill pipe a secured against rotation, releasable connection, and which drill head the End of the drill pipe concludes.

If the building found in the depth of the foundations of a construction project to accommodate the loads proves to be insufficiently viable or causes incompatible large subsidence for the construction, z. As piles used. These transfer the building loads to deeper, load-bearing soil layers.

To produce such a displacement boring pile, a steel pipe, referred to below as a drill pipe, is sealed watertight at the lower end with a special tip, the drill head. Drilling head and drill pipe are connected to each other in a rotationally secure manner. By means of a hydraulic drill this drill pipe is screwed under high vertical pressure to the required depth in the soil, the soil material is displaced by the volume of the drill pipe. When the final depth is reached, a prefabricated pile reinforcement is inserted into the drill pipe and the pipe filled with concrete. Subsequently, the drill pipe is retracted under constant rotation. The drill head separates from the drill pipe and remains in the ground. During retraction, the concrete located in the drill pipe flows out and thus fills the resulting cavity after the retraction of the drill pipe to the required level. Particular attention is paid in this phase, that with sufficiently high concrete filling (load) a hydraulic ground breaking within the drill pipe is avoided. After hardening of the concrete is thus obtained the resilient, reinforced displacement bored pile.

Such drill heads are known in many ways. For example, shows the EP-A 1 279 793 a drill head made of cast steel and having a conical shape which is helical. Such a drill head, which can be used only once, is relatively expensive to produce, in addition, it has a relatively high weight and, accordingly, the transport of such drill heads from the production site to the construction site is complex and takes up a lot of space.

From the EP-A-1 860 274 is a drill head with the features of the preamble of claim 1 can be removed.

The object of the present invention is therefore to design a drill head so that it can be produced with little effort and cost, that it has a low weight and can be stored and transported to save space.

According to the invention, the solution of this object is achieved in that the drill head has a base plate with which the Bohrrohrende is closed, on which base plate at least one substantially perpendicular thereto aligned drill head plate is placed, which drill head plate is equipped with cams, which cam by corresponding to the base plate protruding recesses protrude, which drill head plate is connected to the base plate via connecting means and the cams of the at least one drill pipe plate on the Bohrrohrseite above the base plate projecting and protrude into corresponding drill pipe at the end mounted slots.

Such a drill head thus consists of a few plate-like structures, which can be produced very easily and inexpensively, these plate-shaped structures can be assembled directly on site depending on what are used for connecting means, whereby the transport is greatly simplified.

In that the cams of the at least one drill head plate on the Bohrrohrseite over the base plate are prominent and in accordance with the Drilling tube end mounted slots protrude, on the one hand a simple secured against rotation releasable connection between the drill head and drill pipe is achieved and also ensures that the rotational movement of the drill pipe is transmitted in an optimal manner to the drill head plate of the drill head.

Advantageously, the side edges of the at least one drill head plate project over the peripheral edge of the base plate. Since the diameter of the base plate corresponds at least to the outer diameter of the drill pipe, the soil is displaced so far during the drilling process that sufficient clearance is formed between the drill hole and the drill pipe so that the friction between drill pipe and borehole can be minimized.

A further advantageous embodiment of the invention is that the connecting means consist of hook-shaped projections attached to the cam, so that wedges can be inserted between these hook-shaped projections and the base plate. As a result, the drill head can be assembled in the simplest way on site, the connection between the base plate and drill head plates is very stable.

The invention can also be configured such that the connecting means consist of recesses mounted on the cam, in which at least one retaining clip can be inserted, which is supported on the base plate, whereby another simple connection between the base plate and drill head plate can be achieved.

It can also be provided that the at least one drill head plate is equipped with a centrally arranged additional cam, which is also projecting over the base plate and which is provided with indentations, in which a headband can be inserted, which is supported on the base plate. This also gives a simple connection.

Advantageously, the base plate is equipped such that two drill head plates are placed on this, which Bohrkopfplatten are provided with slot-shaped recesses that the drill head plates are crosswise nestable. This achieves a further embodiment of the drill head.

Advantageously, the cams of those drill head plate are provided with hook-shaped projections, wherein in the assembled state of the two drill head plates with the base plate, the slot-shaped recess is directed against the base plate. As a result, only one of the two drill head plates has to be connected to the base plate, for example via the wedges, the drill head plate thereby also fixes the other drill head plate to the base plate.

The drill head plates can be made by cutting from a commercially available steel plate, whereby a cost-effective and easy production can be achieved. The shape of the drill head plates that form the drill bit can be adapted to the properties of the soil to be drilled. Depending on the nature of the soil, the plates can be provided with a pointed angle forming drill head tip, the tip can also be obtuse, it can be provided rounding, the most appropriate form of these drill head plates can be found for example by experiment.

Embodiments of the device according to the invention are explained in more detail below by way of example with reference to the accompanying drawing.

• Fig. 1 in räumlich auseinandergezogender Darstellung eine erste Ausführungsvariante eines Bohrkopfes, der auf das Bohrrohrende aufsteckbar ist;
• Fig. 2 in räumlicher Darstellung den zusammengesetzten Bohrkopf gemäss Fig. 1;
• Fig. 3 der zusammengesetzte Bohrkopf gemäss Fig. 2, im auf das Bohrende aufgesteckten Zustand, bereit für den Bohreinsatz;
• Fig. 4 in räumlich auseinandergezogender Darstellung eine weitere Ausführungsvariante des erfindungsgemässen Bohrkopfes;
• Fig. 5 der Bohrkopf gemäss Fig. 4, wobei die beiden Bohrkopfplatten ineinandergesetzt sind;
• Fig. 6 in räumlicher Darstellung die beiden Bohrkopfplatten gemäss Fig. 5, eingesetzt in die Basisplatte und mit dieser verbunden;
• Fig. 7 der Bohrkopf gemäss Fig. 6 im auf das Bohrrohrende aufgesteckten Zustand, bereit für den Bohreinsatz;
• Fig. 8 eine Schnittdarstellung durch den auf das Bohrrohrende aufgesteckten Bohrkopf gemäss Fig. 7;
• Fig. 9 eine Draufsicht auf einen Bohrkopf mit einer anderen Ausgestaltung der Verbindung;
• Fig. 10 eine Schnittdarstellung des Bohrkopfes gemäss Fig. 9
• Fig. 11 eine Draufsicht auf einen Bohrkopf mit einer weiteren Ausgestaltung der Verbindung
• Fig. 12 eine Schnittdarstellung des Bohrkopfes gemäss Fig. 11
• Fig. 13 eine Draufsicht auf einen Bohrkopf mit einer weiteren Ausgestaltung der Verbindung; und
• Fig. 14 eine Schnittdarstellung des Bohrkopfes gemäss Fig. 13.

It shows

• Fig. 1 in spatially auseinandergezogender representation of a first embodiment of a drill head, which is attachable to the Bohrrohrende;
• Fig. 2 in a spatial representation of the composite drill head according to Fig. 1 ;
• Fig. 3 the composite drill head according to Fig. 2 in the state put on the drilling, ready for the drill bit;
• Fig. 4 in spatially auseinandergezogender representation of a further embodiment of the inventive drill head;
• Fig. 5 the drill head according to Fig. 4 wherein the two drill head plates are placed one inside the other;
• Fig. 6 in a spatial representation of the two drill head plates according Fig. 5 inserted into the base plate and connected to it;
• Fig. 7 the drill head according to Fig. 6 in the plugged on the Bohrrohrende state, ready for the drill bit;
• Fig. 8 a sectional view through the attached to the drill pipe end drill according to Fig. 7 ;
• Fig. 9 a plan view of a drill head with another embodiment of the compound;
• Fig. 10 a sectional view of the drill head according to Fig. 9
• Fig. 11 a plan view of a drill head with a further embodiment of the compound
• Fig. 12 a sectional view of the drill head according to Fig. 11
• Fig. 13 a plan view of a drill head with a further embodiment of the compound; and
• Fig. 14 a sectional view of the drill head according to Fig. 13 ,

From the Fig. 1 to 3 a first embodiment of a drill head according to the invention can be seen. This drill head 1 comprises a base plate 2, which is circular. This base plate is provided with two recesses 3, which are rectangular in shape and lie on a diameter of the base plate 2.

This drill head 1 shown here comprises a drill head plate 4, which consists of a base body 5 which is rectangular in shape and on which two cams 6 are mounted. The drill head plate 4 is placed on the base plate 2, wherein the cams 6 protrude through the recesses 3 of the base plate 2, as is made Fig. 2 is apparent. In this position, in which the drill head plate 4 is perpendicular to the base plate 2, the drill head plate 4 is connected to the base plate 2. For this purpose, connecting means 7 are provided, which consist of hook-shaped projections 8 which are attached to the cam 6. Between these hook-shaped projections 8 and the base plate 2 wedges 9 can be used, whereby the drill head plate 4 is held on the base plate 2. These wedges 9 are inserted by hammering, the edges directly contacting each other are plastically deformed, the wedges 9 are thereby secured against loosening independently.

How out Fig. 3 can be seen, the end portion 10 of the drill pipe 11 can be placed on the thus assembled drill head 1. For this purpose, 11 slots 12 are mounted on the end portion 10 of the drill pipe into which project beyond the base plate 2 projecting cam 6 of the drill head plate 4. Thereby, the rotational movement of the drill pipe 11 is transferred in an optimal manner to the drill head plate 4 during the drilling process.

In order to avoid that the drill head 1 during the drilling process in the longitudinal direction of the cam 6 can slide out of the end portion 10 of the drill pipe 11, 2 additional cams can be mounted on the base plate, which protrude into the free slots 13 of the end portion 10 of the drill pipe 11. As a result, the drill head 1 is held centrally on the end region 10 of the drill pipe 11. These additional cams can be screwed onto the base plate 2, they can also be welded to this.

As a whole out Fig. 3 it can be seen, the diameter of the base plate 2 is slightly larger than the outer diameter of the end portion 10 of the drill pipe 11. In addition, the side edges of the drill head plate 4 project beyond the peripheral edge of the base plate 2. This will make the diameter the bore produced in the soil larger than the diameter of the drill pipe, whereby the friction between the bore wall and drill pipe can be kept low during pipe retraction.

On the outer wall of the end portion 10 of the drill pipe 11 wedges are attached, which are bent and are adjacent to the wall of the end portion 10 of the drill pipe 11, wherein the diameter during the rotation of the drill pipe 11 is increasing.

The base plate 2 and the drill head plate 4 can be produced in a simple manner in which they are cut out of commercially available steel plates. The base plate 2 may have a thickness of, for example, about 10 mm with a bore diameter of about 500 mm, since this only has to close the end region of the drill pipe 11, while the thickness of the drill head plate 4 may be about 30 mm.

As has been described for this present embodiment, the connecting means 7 consist of wedges 9, which allows easy assembly of the drill head of base plate 2 and drill head plate 4 at the site for this drill head. As a result, the drill head can be delivered in individual parts, which greatly facilitates handling and space requirements. Of course, it would also be possible to weld the drill head plate to the base plate, one would also have a cheap production variant here, but the handling would be somewhat more complicated.

Another embodiment of the invention is in the Fig. 4 to 8 shown. In the following description, parts corresponding to the previously described embodiment of the invention are given the same reference numerals. The drill head 1 in turn consists of a base plate 2 which is provided with four recesses 3, which are each arranged at 90 ° on the circular base plate. In this embodiment, two drill head plates 4 and 4 'are provided, which are inserted into the base plate 2. Both drill head plates 4 and 4 'are in turn equipped with two cams 6, which are mounted on the base body 5 of the drill head plates 4 and 4 '.

The two drill head plates 4 and 4 'are inserted crosswise and perpendicular to each other, for which purpose these two drill head plates 4 and 4' are each provided in the middle region with a slot-shaped recess 14, as is apparent from Fig. 5 is apparent. The so-pushed drill head plates 4 and 4 'can then be inserted into the base plate 2, as in Fig. 6 The connecting means 7, with which the drill head plates 4 and 4 'are connectable to the base plate 2, again consist of hook-shaped projections 8 attached to the cams 6 of the drill head plate 4', so that between these hook-shaped projections 8 and the base plate 2 wedges 9 can be driven. The drill head plate 4 is held by the nesting with the drill head plate 4 'via these connecting means 7 also on the base plate 2, for the drill head plate 4 thus the cam 6 need not be provided with hook-shaped projections, as is apparent from Fig. 6 is apparent.

In turn, the end portion 10 of a drill pipe 11 is placed on this drill head 1, for which purpose this end portion 10 is provided with slots 12 into which the cams 6 of the drill head plates 4 and 4 'protrude Fig. 7 is apparent. As a result, in turn, the rotational movement during the drilling process of the drill pipe 11 can be transferred in an optimal manner directly to the drill head plates 4 and 4 '.

Again, for the reasons already described above, the diameter of the base plate 2 is slightly larger than the diameter of the drill pipe 11, the drill head plates 4 and 4 'are laterally above the base plate 2 above, also here at the end portion 10 of the drill pipe wedges 11 can be added.

From the sectional view according to Fig. 8 is the end portion 10 of the drill pipe 11 can be seen, in the slots 12, the cams 6 of the two drill head plates 4 and 4 'are inserted. The two drill head plates 4 and 4 'are held over the hook-shaped projections 8 and driven between these hook-shaped projections 8 and the base plate 2 wedges 9. As can be seen from this illustration, one side 15 of the slots 12 is slightly inclined relative to the cams 6, the other side 16, which presses on the cam during the drilling process, lies fully against this cam. As a result, the end region 10 of the drill pipe 11 can be placed more easily on the drill head 1.

Like that Fig. 4 to 8 can be removed, the base body 5 and 5 'of the drill head plates 4 and 4' against the well plate toward a tapered region. The shaping of these tips may be formed depending on the soil to be drilled, depending on the ground conditions of the soil to be drilled, the shape designs may be different, which is advantageously determined by experiments.

The FIGS. 9 and 10 show a drill head 1, which in turn is formed from two drill head plates 4 and 4 'and a base plate 2. On the cam 6 of the drill head plate 4 'indentations 17 are mounted. In these indentations 17, a headband 18 is inserted such that in each case one leg 19 of this retaining clip 18 comes to rest in a recess 17 of a respective cam 6 and the drill head plate 4 'and thus the drill head plate 4, as has been described for the previously illustrated embodiment , are attached to the base plate 2. The retaining bracket 18 may be made of a metallic rod by appropriate bending.

From the FIGS. 11 and 12 a further variant of a connection between the drill head plates 4 and 4 'with the base plate 2 is shown. The drill head plate 4 'is in this case equipped with an additional, centrally arranged cam 20, which protrudes through a corresponding recess in the base plate 2 and on whose two opposite sides in each case a recess 17 is attached. In these indentations 17, in turn, a headband 18 is inserted such that in each case a leg 19 of this retaining clip 18 comes to lie in one of the indentations 17 of this additional cam 20 and the drill head plate 4 'and Thus, the drill head plate 4 is fixed to the base plate 2. The retaining bracket 18 may in turn be formed from a bent metallic rod.

Another possibility for connection between the drill head plates 4 and 4 'and the base plate 2 is the FIGS. 13 and 14 removable. The drill head plate 4 'is provided with an additional, centrally arranged cam 20, which, as in the previously described variant, is provided with indentations 17. In addition, indentations 17 are also attached to the two cams 6 of this drill head plate 4 ', according to the variant according to FIG FIGS. 9 and 10 , In this indentations 19, two headband 18 and 18 'can be used so that in each case one leg 19 of each retaining bracket 18 and 18' in the recess 17 of a cam 6 comes to rest, while the other leg 19 of each retaining bracket 18 and 18 'in a Dent 17 of the additional cam 20 comes to rest. Again, the headband 18 and 18'jeweils be formed from a correspondingly bent metallic rod. Here, a headband 18 may also be designed such that it is in use in all four indentations.

Also in these inventive embodiments of a drill head 1, the base plate 2 and the drill head plates 4 and 4 'can be cut in a simple manner from commercially available steel plates, as described in the first embodiment. Again, the drill heads 1 can be transported in a simple and space-saving manner to the place of use and assembled on site, which facilitates their handling.

Of course, the base plate 2 and the drill head plates 4 and 4 'are welded together, but this would complicate the handling something.

With this inventive embodiment drilling heads can be produced in a simple manner, which are suitable for creating wells in unsustainable soil, in which holes then concrete piles are created, the drill heads remain in the ground. In addition to the ease of manufacture and handling, these are Drilling heads also cost-effective. In addition, the shape of the drilling area of these drill heads can be designed in many ways, depending on the ground conditions of the soil, in which these holes are to be attached.

LIST OF REFERENCE NUMBERS

1

wellhead

2

baseplate

3

recesses

4,4 '

drill plates

5

body

6

cam

7

connecting means

8th

hook-shaped projections

9

wedges

10

end

11

drill pipe

12

slots

13

free slots

14

slot-shaped recess

15

page

16

page

17

indentations

18.18 '

headband

19

leg

20

additional cam

Claims (9)

1. Drill head for a drilling device for making drill holes in insufficiently stable foundation by displacement of the soil material, which drill head (1) is placeable on a drill pipe (11) of the drilling device and forms with the drill pipe (11) a releasable connection secured against rotation, and which drill head (1) closes off the end of the drill pipe (11), characterised in that the drill head (1) has a base plate (2), with which the drill pipe end is closable, on which base plate (2) at least one drill head plate (4, 4'), oriented substantially perpendicular thereto, is placed, which drill head plate (4, 4') is provided with locking projections (6), which locking projections (6) project through corresponding recesses (3) made on the base plate (2), which drill head plate (4, 4`) is connected to the base plate (2) via connecting means (7) and the locking projections (6) of the at least one drill head plate (4, 4') are protuberant beyond the base plate (2) on the drill pipe side and project into slots (12) made correspondingly on the drill pipe end.
2. Drill head according to claim 1, characterised in that the side edges of the at least one drill head plate (4, 4') are protuberant beyond the peripheral edge of the base plate (2).
3. Drill head according to claim 1 or 2, characterised in that the diameter of the base plate (2) corresponds at least to the outer diameter of the drill pipe (11).
4. Drill head according to one of the claims 1 to 3, characterised in that the connecting means (7) are made up of hook-shaped projections (8) made on the locking projections (6), so that wedges (9) are insertable between these hook-shaped projections (8) and the base plate (2).
5. Drill head according to one of the claims 1 to 3, characterised in that the connecting means (7) are made up of indentations or recesses (17) made on the locking projections (6), in which indentations or recesses at least one holding clamp (18; 18') is insertable, which is supported on the base plate (2).
6. Drill head according to one of the claims 1 to 3 or according to claim 6, characterised in that the at least one drill head plate (4, 4') is provided with a centrally disposed additional locking projection (20), which is likewise protuberant beyond the base plate (2) and which is provided with indentations or recesses (17) in which a holding clamp (18) is insertable, which is supported on the base plate (2).
7. Drill head according to one of the claims 1 to 6, characterised in that the base plate (2) is designed in such a way that two drill head plates (4, 4') are placeable thereon, which drill head plates (4, 4') are provided with slot-shaped recesses (14) in such a way that the drill head plates (4, 4') are able to be put into each other crosswise.
8. Drill head according to claim 7, characterised in that the locking projections (6) are provided to that drill head plate (4') with hook-shaped projections (8), where, in assembled state of the two drill head plates (4, 4') with the base plate (2), the slot-shaped recess (14) is directed toward the base plate (2).
9. Drill head according to one of the claims 1 to 8, characterised in that the drill head plates (4, 4') are producible by means of cutting out from a commercially available steel plate.

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