DE202009018579U1 - Device for expanding a pilot hole in the ground - Google Patents

Abstract

Device for expanding a pilot bore in the ground, comprising a) a screw (3) that can be assembled from shots and b) a borehole opener (1) fixed to the screw (3) in a torsion-proof and tensile manner, characterized by c) a screw that can be assembled from shots (3) Surrounding screw tube (9) allowing screw conveyance, the screw tube (9) having at least one spoil opening (10) at its end facing the borehole opener (1) for receiving spoil.

Description

The invention relates to a device for expanding a pilot hole in the ground. The device comprises a screw which can be composed of shots and a borehole opener which is fixed against rotation and tension on the screw. The apparatus can be used in a method in which a borehole opener driven by a screw for rotation is pulled in from a target pit in the direction of a starting pit and transported in the bore extension waste by means of a screw in the starting pit.

It is known when expanding new ears, in particular plastic pipes, to widen a pilot hole already existing between the start and finish pit. In this case, a borehole opener or backreamer is connected to a multi-shot steel pipe in the target pit, to which in turn the new pipe is attached via a connecting piece. Borehole openers and neurohres are drawn to the starting pit via the steel tube. In particular, in the case of plastic new ears whose surface is to protect against excessive engagement of the surrounding soil. As a result, the diameter of the borehole opener is significantly larger than that of the neural tube, and the neural ear is constantly bathed in bentonite. The torque for the hole opener is transmitted through the steel tube. In order to prevent turning of the new pipe, it is connected to the borehole opener with a swivel. The overburden produced by the borehole opener is conveyed together with the bentonite surrounding the new pipe towards the target pit. The amount of bentonite to be used is very high.

From the DE 25 07 984 B2 It is known to expand a pilot hole by means of a borehole opener in the production of a connection tunnel between substantially parallel traffic tunnels, wherein the borehole opener is pulled by a screw conveyor, which simultaneously transports the overburden to the launch tunnel. In order for such a removal is possible, the surrounding soil must be solid, otherwise it would come to Versackungen due to slipping of the soil.

It is an object of the present invention to provide a device of the type mentioned, with which a promotion of the spoil generated by the borehole opener via the screw to the starting pit is possible even in loose soil.

In a device of the aforementioned type, the aforementioned object is achieved by the characterizing features of patent claim 1. Advantageous embodiments of the device according to the invention will become apparent from the dependent claims.

The auger tube supports the pending soil and thus allows only the promotion of the degraded by the borehole opener soil. The borehole opener can be pulled in the case of a tensile trained snail by means of the screw.

It is advantageous to pull the borehole opener by means of the screw tube. The worm then does not need to be trained tensile.

This procedure is particularly advantageous in the case of the retraction of a neuro-ear, in particular one made of plastic. Compared to the previously used and initially described method bentonite is required only for lubrication of the plastic pipe due to the overburden conveyed by the screw tube, resulting in a significant reduction of the required amount of bentonite.

The at least one overburden opening allows access to the overburden in the screw tube, where it is transported by means of auger conveyance into the starting pit. In an advantageous variant, the screw tube, which preferably consists of steel, indirectly draws the borehole opener via a pressure bearing between the end ring of the screw tube and the screw. The tensile force of the screw tube is transmitted via the axial forces receiving thrust bearing on the last shot of the screw, which is rotatably connected with the borehole opener and tensile, whereby the latter can be pulled to the starting pit.

The optional shield element is used to prevent unwanted slipping or falling off the edge of the enlarged borehole. The shield element can be attached to the borehole opener itself and rotate with the borehole opener. But it is also possible to fix the shield element to the coupling unit. If the shield element with its shield function is formed continuously from the coupling unit to the borehole opener, the area between the coupling unit and the borehole opener is thus also protected by the shield element. The latter is possible both when fixed to the coupling unit as well as fixation at the borehole opener.

The shield member may comprise the entire circumference of the borehole opener or only a part thereof. The shield element can, for. B. be provided over one-third to half of the circumference, which may be sufficient in suitable soil, the slipping of the soil from above and if necessary, from the sides in the direction of the overburden opening (s) to prevent.

An advantageous embodiment of the method according to the invention and the device according to the invention are illustrated below with reference to a figure.

The single FIGURE shows a cross-sectional view schematically a borehole opener 1 with shovel elements 2 of which only one is shown here, the borehole opener 1 torsional and tensile with the last shot of a screw 3 via a connection point 4 is fixed. About a Swivel (a tension-resistant swivel joint) 5 is at the borehole opener 1 a train pot 6 connected to that via fixing holes 7 a neuro-ear 8th can be fixed.

The snail 3 is from a snail pipe 9 surrounded, at his the borehole opener 1 facing end overburden openings 10 having. In the spiral tube 9 is at his the borehole opener 1 facing end a closing ring 11 , z. B. by means of a welded joint, fixed. At this end ring 11 is the snail 3 by means of an axial forces receiving thrust bearing 12 rotatably mounted. The snail pipe 9 is like the snail 3 built from several shots, of which in the figure only the last shot can be seen. The shots of the snail pipe 9 are tensile with each other, while a high-tensile connection between the wefts of the screw 3 is dispensable.

For feeding the neuro ear 8th becomes the borehole opener 1 by means of the snail 3 turned while the auger tube 9 does not rotate. When the auger tube 9 is pulled to the starting pit out by means of a traction device, not shown here, the tensile force on the end ring 11 and the thrust bearing 12 on a tail 13 the snail 3 transfer. Because of the over the junction 4 given tensile and rotationally fixed connection between the screw 3 and the borehole opener 1 Be the one with the snail 3 co-rotating borehole openers 1 and with him the swivel 5 and the attached, because of the Swivels 5 not co-rotating neuro-ear 8th also pulled in the direction of the starting pit. The with cutting teeth 15 equipped vane elements 2 of the rotating borehole opener 1 dissolve the soil, which over the Abraumöffnungen 10 in the auger tube 9 falls and then due to the rotational movement of the screw 3 is transported to the starting pit.

So that in case of loose ground this not following the gravity of the edge of the enlarged borehole in the direction of the screw tube 3 slips, is on the train pot 6 a the borehole opener 1 covering shield element 14 intended. The scoop elements 2 of the borehole opener 1 have at their outer end in each case an obliquely outward external tooth 16 on, in front of the shield element 14 the soil cuts and so the shield element 14 clear the way. The shield element 14 As shown in the figure, it is an upper portion of the circumference of the borehole opener 1 limited. The shield element 14 but may also include the borehole opener completely.

During the retraction of the neuro-ear 8th Bentonite is not shown here, through the interior of the neural tube 8th extending supply line through an opening in the pipe wall on the outside of the new ear 8th given (in the figure by arrow 17 indicated), whereby the friction load of the neuro ear 8th is reduced.

LIST OF REFERENCE NUMBERS

1

hole openers

2

vane element

3

slug

4

junction

5

Swivel

6

Zugtopf

7

fixing holes

8th

new pipe

9

steel tube

10

overburden opening

11

end ring

12

thrust bearing

13

tail

14

shield element

15

Scheid tooth

16

outdoor gear

17

Bentonitfluss

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2507984 B2 [0003]

Claims (7)

Device for expanding a pilot hole in the ground, comprising a) a screw which can be assembled from shots ( 3 ) and b) a rotational and tensile strength on the screw ( 3 ) fixed borehole opener ( 1 ), characterized by c) a weft-assemblable, the worm ( 3 ) surrounding, a screw conveyor permitting screw tube ( 9 ), whereby the screw tube ( 9 ) at its the borehole opener ( 1 ) facing end at least one overburden opening ( 10 ) for receiving overburden. Device according to claim 1, characterized in that the screw ( 3 ) in the area of the borehole opener ( 1 ) facing end via an at least axially acting thrust bearing ( 12 ) on the screw tube ( 9 ) rotatably mounted and the screw tube ( 9 ) tensile strength is designed. Apparatus according to claim 2, characterized in that in the screw tube ( 9 ) at which the borehole opener ( 1 ) facing end a closing ring ( 11 ) on the screw tube ( 9 ) and the screw ( 3 ) over the thrust bearing ( 12 ) on the closing ring ( 11 ) is stored. Device according to one of claims 1 to 3, characterized in that the borehole opener ( 1 ) a coupling unit ( 5 . 6 ) for coupling an object, in particular a neuro-ear ( 8th ), is provided. Device according to one of claims 1 to 4, characterized in that a the periphery of the borehole opener ( 1 ) at least partially comprehensive in the pulling direction over the at least one overburden opening ( 10 ) projecting and at least partially slipping off soil from the edge of the widened bore preventing shield element ( 14 ) is provided. Device according to claim 4 and 5, characterized in that the shield element ( 14 ) at the docking unit ( 5 . 6 ) is fixable. Device according to claim 5, characterized in that the shield element ( 14 ) at the borehole opener ( 1 ) is fixed.

Images