Ground Drilling Device and Method for Drilling in Soil

Abstract

A ground drilling device for drilling in soil by means of a drill string, wherein the ground drilling device comprises a drilling carriage and a sled movable in translation on the drilling carriage, and on the sled there is arranged a holder a) for the screwed connection of a rod section to the drill string, or b) for the screwed detachment of a rod section from the drill string, wherein the holder can move in translation relative to the sled in order to compensate for a change in the position of the holder caused by the screwing process.

Claims

1. Ground drilling device for drilling in soil by means of a drill string, wherein the ground drilling device comprises a drilling carriage and a sled movable in translation on the drilling carriage, and on the sled there is arranged a holder a) for the screwed connection of a rod section (5) to the drill string or b) for the screwed detachment of a rod section (5) from the drill string, wherein the holder is configured to move in translation relative to the sled in order to compensate for a change in the position of the holder caused by the screwing process.

2. Ground drilling device according to claim 1, wherein a carrier supporting the holder is movably arranged on the sled and configured to be secured to the sled.

3. Ground drilling device according to claim 2, wherein the carrier is configured to be secured on the sled by means of a bolt.

4. Ground drilling device according to claim 1, further comprising a sensor for detecting the end of the screwing process, and providing a signal for receipt by a control device in order to achieve a securing of the holder to the sled.

5. Ground drilling device according to claim 4, wherein the sensor may be configured as one of an end switch, a proximity switch, or a position switch.

6. Ground drilling device according to claim 1, further comprising an input device which produces a signal that can be received by a control device in order to accomplish a securing of the holder on the sled.

7. Method for drilling in soil by means of a drill string, wherein a sled which is movable in translation is used for the pulling and/or pushing of the drill string, and on the sled there is arranged a holder, with which a rod section can be screwed onto or unscrewed from a drill string, wherein the holder is moved in translation relative to the sled in order to compensate for a change in the position of the holder caused by the screwing process.

8. Method according to claim 7, further comprising providing input device which can be activated by means of an attendant, and wherein the holder is secured to the sled by means of an entry using the input device.

9. Method according to claim 7, wherein the holder is secured to the sled responsive to detection of a signal of a sensor.

10. Ground drilling device according to claim 2, wherein the carrier is configured to be secured on the sled by means of a hydraulically activated bolt.

Description

[0029] The drawings show:

[0030] FIG. 1 a side view of a ground drilling device in schematic representation;

[0031] FIG. 2 a sled of a ground drilling device before screwing of a rod section onto an already introduced drill string; and

[0032] FIG. 3 a sled of a ground drilling device after screwing a new rod section onto the already introduced drill string.

[0033] FIG. 1 shows in a schematic representation from the side a ground drilling device 1, which works by soil displacement. With the ground drilling device 1, a drill string comprising rod sections 5 can be introduced into the soil by translation as well as rotation. For this, a sled 4 can move back and forth on a drilling carriage 2. The drilling carriage 2 defines, with the sled 4 or a holder 3, a drill string axis 7. The holder 3 is fashioned on the sled 4 in the form of an adapter or a connection by means of which a newly attached rod section 5 can be connected to the already introduced drill string and then be introduced into the soil.

[0034] The rod sections 5 are screwed together. For this, corresponding interacting threads are provided at the ends on the rod sections 5. The holder 3 forms a form fit with the rod section 5 being connected to the already introduced drill string. The rod section 5 is screwed onto the introduced drill string and the holder 3 and then the sled 4 travels in the direction of the drill string axis 7 on the drilling carriage 2.

[0035] FIG. 2 shows in a schematic view the condition before the holder 3 is connected to the rod section 5. The sled 4 comprises the holder 3, which is firmly connected to it on a carrier 9. The holder 3 is secured to the carrier 9 in the direction of the drill string axis 7. The holder 3 can rotate, but not move by displacement relative to the carrier 9.

[0036] The holder 3 is movable relative to a base 8 of the sled 4, while the carrier 9 may be secured relative to the base 8. For this, a form fit is provided between a bolt 10 and a holder borehole 12. The bolt 10 is designed as a movable bolt on the carrier 9. The bolt 10 is part of a locking device 6. The bolt 10 can be extended and retracted by means of a hydraulic cylinder 11. In the position shown in FIG. 2, the sled 4 is in a rear position on the drilling carriage 2 and extended onto a rod section 5 being screwed onto a drill string already situated in the soil. The carrier 9 has been moved backward relative to the base 8, opposite the drilling direction. The carrier 9 is pulled forward on the base 8 by the subsequent screwing of the holder 3 onto the new rod section 5 and the screwing of the new rod section 5 onto a drill string already located in the soil, not shown here. During the screwing process, the bolt 10 is in the retracted condition, as shown in FIG. 2.

[0037] When both threads of the new rod section 5 have been completely screwed on, i.e., both the front thread to the already introduced drill string and the rear thread to the holder 3, the carrier 9 is in a forward position, as shown in FIG. 3. The bolt 10 in this position of the carrier 9 relative to the base 8 can be retracted into the holder borehole 12 of the base 8 and now prevents a relative movement between base 8 and carrier 9. In this constellation, the drilling process is now continued at once; the sled 4 can be moved as a whole, so that the carrier 9 and the base 8 can be moved together. A travel of the sled 4 or the base 8 until the carrier 9 strikes against the end stop 13 can be avoided. Once the new rod section 5 has been introduced into the soil with the already introduced drill string, the bolt 10 can be retracted and the carrier 9 can move back with the holder 3 and the process of connecting a new rod section 5 to the introduced drill string can begin again.