Double head drilling device and method for producing a bore

Abstract

The invention relates to a double head drilling device for a drill rod having an outer pipe and an inner rod running at least in sections inside the outer pipe, with a first drive unit for driving the inner rod in a rotating manner and a second drive unit for driving the outer pipe in a rotating manner. According to the invention provision is made in that for the releasable clamping of the inner rod a first clamping head and a second clamping head are provided and in that the two clamping heads are supported in an axially displaceable manner with respect to each other. Furthermore, the invention also comprises a method for producing a bore with this double head drilling device.

Claims

1. A double head drilling device for a drill rod having an outer pipe and an inner rod running at least in sections inside the outer pipe, the device comprising: a first drive unit for driving the inner rod in a rotating manner, and a second drive unit for driving the outer pipe in a rotating manner, wherein for a releasable clamping of the inner rod a first clamping head and a second clamping head are provided, the first and second clamping heads are supported in an axially displaceable manner with respect to each other, and the second clamping head is configured to clamp the inner rod and to be displaced axially with the clamped inner rod with respect to the outer pipe while the first clamping head is released from the inner rod.

2. The double head drilling device according to claim 1, wherein the first and second clamping heads can be actuated independently of each other for alternately clamping of the inner rod.

3. The double head drilling device according to claim 1, wherein the first clamping head is firmly arranged on the first drive unit and the second clamping head is supported in an axially displaceable manner with respect to the first drive unit.

4. The double head drilling device according to claim 1, wherein for displacement of the second clamping head at least one displacement cylinder is provided.

5. The double head drilling device according to claim 1, wherein at least one linear guide is provided, along which the second clamping head is guided.

6. The double head drilling device according to claim 1, wherein in a clamped state the first clamping head is designed to hold the inner rod in an axially fixed and rotatable manner for a torque transmission of a torque from the first drive unit.

7. The double head drilling device according to claim 1, wherein in a clamped state the second clamping head is designed to hold the inner rod in an axially fixed and torque-proof manner.

8. The double head drilling device according to claim 1, wherein the first clamping head and/or the second clamping head is configured to be connected in a force-locked manner to the inner rod.

9. The double head drilling device according to claim 1, wherein the second clamping head is of annular design with a passage opening for the inner rod, wherein by means of the second clamping head the inner rod can be moved stepwise into the first drive unit or moved out of the second drive unit.

10. A drilling apparatus having: a carrier vehicle and a mast or a mounting, along which a double head drilling device is guided in a displaceable manner, wherein the double head drilling device according to claim 1 is provided.

11. A method for producing a bore, comprising: setting a drill rod having an outer pipe and an inner rod running at least in sections inside the outer pipe into rotation, and moving the drill rod axially by means of the double head drilling device according to claim 1.

12. The method according to claim 11, wherein for displacement of the inner rod, the inner rod is clamped by the second clamping head, the first clamping head is released from the inner rod, and the second clamping head with the clamped inner rod is displaced axially.

Description

(1) The invention is set out further hereinafter by way of a preferred embodiment illustrated schematically in the drawing.

(2) FIG. 1 shows a side view of a double head drilling device 10 according to the invention.

(3) FIG. 2 shows a side view of a double head drilling device 10 shown in FIG. 1 with an outer pipe.

(4) FIG. 3 shows a system overview showing the drilling device 10 in relation to a ground being drilled.

(5) As shown in FIG. 1, the double head drilling device 10 has a carriage 40, with which the double head drilling device 10 can be moved linearly along a mast 101 of a drilling apparatus 100, as shown in FIG. 3. As shown in FIG. 3, the drilling apparatus 1 is configured to produce a borehole 2 and has a carrier vehicle 102 and the mast 101 or a mounting, along which the double head drilling device 10 is guided in a displaceable manner. In particular, the drilling apparatus 100 can be used for producing bored piles in the ground 1. The carrier vehicle 102 of the drilling apparatus 100 normally has a substantially vertically directed mast 101, along which the double head drilling device 10 is guided in a vertically displaceable manner.

(6) The double head drilling device according to the invention comprises a first drive unit 12 and a second drive unit 14. The second drive unit 14 is designed with an annular drive flange 16, to which a cardanic swivel joint 18 is attached. On the swivel joint 18 an outer pipe 60, also referred to as drill pipe, is fixed which is not illustrated in FIG. 1 for reasons of clarity but shown in FIG. 2. By means of the second drive unit 14 the outer pipe 60 can be driven in a rotating manner in order to be drilled into the ground.

(7) The first drive unit 12 is designed for driving a cylindrical inner rod 50. The inner rod 50 protrudes through the double head drilling device 10 with the annular drive units 12, 14. On the illustrated front end of the inner rod 50 a polygonal connecting piece 52 is arranged, on which a drilling tool, such as a drilling auger or a drilling bucket, can be releasably fixed. The inner rod 50 can be of pipe-shaped design with an internal duct to introduce through this e.g. concrete or another hardening mass into a produced borehole 2.

(8) The two drive units 12, 14 have annular drive wheels for the torque transmission to the inner rod 50 or the outer pipe 60. The torque is produced by rearward arranged hydraulic motors 20 that transmit the torque via a gear transmission means 21 to the drive wheels of the two drive units 12, 14. The two drive units 12, 14 are firmly connected to each other by at least one connecting bar 38. Alternatively, the two drive units 12, 14 can also be axially movable with respect to each other by way of axial positioning cylinders.

(9) For axial movement of the inner rod 50 with respect to the outer pipe 60 an annular first clamping head 22 is arranged at the rear end of the first drive unit 12. In the clamped state the first clamping head 22 can hold the inner rod 50 such that it is axially fixed but rotatable about a drilling axis 11. Moreover, axially spaced thereto a second clamping head 24 is arranged that can clamp the inner rod 50 in an axially fixed and torque-proof manner. The second clamping head 24 can preferably be of annular or of another design.

(10) When a second clamping head 24 is clamped and a first clamping head 22 is released, the second clamping head 24, together with the clamped inner rod 50, can be displaced axially by means of a displacement cylinder 30 between a starting position and an end position. In this, the second clamping head 24 is guided in a torque-proof manner by a guide shoe 35 along a bar-shaped linear guide 34.

(11) Thus, with the second clamping head 24 the inner rod 50 can be displaced axially according to the stroke of the displacement cylinder 30. Afterwards, the second clamping head 24 can be released again and returned to the starting position. During this return movement process the inner rod 50 can be clamped and fixed in the position by the first clamping head 22. Subsequently, a renewed clamping by the second clamping head 24 can take place, in which case the first clamping head 22 is released again from the inner rod 50. Henceforth a displacement step can again be carried out by the second clamping head 24 with the displacement cylinder 30.

(12) In this way, an inner rod 50 of almost any length that protrudes through both drive units 12, 14 and both clamping heads 22, 24 can be used in double head drilling. Through repeated stepwise displacement of the inner rod 50 with respect to the outer pipe 60 a drilling tool can run ahead by almost any length with respect to the lower end of the outer pipe 60.