Controllable drilling head

Abstract

A controllable drilling head for a drill string for ground drilling with a drilling head tip and a locating pin that carries the drilling head tip, the drilling head tip having a bore slanted to the longitudinal axis and the locating pin being angled to the longitudinal axis, wherein the drilling head tip can rotate on the locating pin, the drilling head tip and the locating pin being arranged in a first angular position relative to one another for straight drilling, and the drilling head tip and the locating pin being arranged in a second angular position relative to one another for drilling that deviates from straight drilling.

Claims

1. A ground drilling device comprising: a controllable drilling head comprising a drilling head tip and a locating pin that carries the drilling head tip, wherein the drilling head tip has defined therein a bore slanted to a longitudinal axis; wherein the locating pin is angled to the longitudinal axis, and wherein the drilling head tip is rotatable on the locating pin, the drilling head tip and the locating pin being arranged in a first angular position relative to one other for straight drilling, and the drilling head tip and the locating pin being arranged in a second angular position relative to one another for drilling that deviates from straight drilling; and a drive for pushing or pulling a drill string with the drilling head; wherein the drive is adapted to be positioned in an excavation pit or a shaft, wherein the locating pin comprises two locating pin stop surfaces, or the bore is delimited by two bore stop surfaces, and wherein the two locating pin stop surfaces or the two bore stop surfaces are spaced apart from one another in the longitudinal direction of the drilling head tip or the locating pin, and the two locating pin stop surfaces or the two bore stop surfaces form end positions of a relative rotational movement of the locating pin in the bore, and wherein the ground drilling device further comprises a scale positioned in an area of the drive, by means of which a degree of rotation of the two locating pin stop surfaces or the two bore stop surfaces about the longitudinal axis of the locating pin or the bore is displayed.

2. A method for controlling a drilling head of a ground drilling device, the drilling head on a drill string for ground drilling, the drilling head having a drilling head tip and a locating pin that carries the drilling head tip, the drilling head tip having a bore slanted to a longitudinal axis and the locating pin being angled to the longitudinal axis, the method comprising: rotating the drilling head tip relative to the locating pin to bring into a first angular position for straight drilling; and bringing the drilling head tip and the locating pin into a second angular position relative to one another for drilling that deviates from straight drilling, wherein the locating pin comprises two locating pin stop surfaces, or the bore is delimited by two bore stop surfaces, and wherein the two locating pin stop surfaces or the two bore stop surfaces are spaced apart from one another in the longitudinal direction of the drilling head tip or the locating pin, and the two locating pin stop surfaces or the two bore stop surfaces form end positions of a relative rotational movement of the locating pin in the bore, and wherein the ground drilling device comprises a scale positioned in an area of the drive, by means of which a degree of rotation of the two locating pin stop surfaces or the two bore stop surfaces about the longitudinal axis of the locating pin or the bore is displayed.

3. The ground drilling device according to claim 1, wherein the bore forms a 5° angle with respect to the longitudinal axis and/or a bend of the locating pin forms a 5° angle with respect to a longitudinal axis of the locating pin.

4. The ground drilling device according to claim 1, wherein the drilling head tip comprises a diameter of less than 70 mm.

5. The ground drilling device according to claim 1, wherein the locating pin is at least partially surrounded by a wear sleeve.

6. The ground drilling device according to claim 1, wherein the two locating pin stop surfaces or the two bore stop surfaces form an angle of greater than 45° to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is clarified below with reference to the exemplary embodiment shown in the figures.

(2) The figures show:

(3) FIG. 1 a ground drilling device with parts of a drill string in an isometric view;

(4) FIG. 2 a section through a front area of a drill string with a drilling head in a first angular position;

(5) FIG. 3 the front area of the drill string with the drilling head of FIG. 2 in a second angular position; and

(6) FIG. 4 an enlarged view of FIG. 1 in the area of the drive of the ground drilling device.

DETAILED DESCRIPTION

(7) FIG. 1 shows a ground drilling device 1, which can be braced by means of supports 2 arranged on the frame in an excavation pit (not shown).

(8) A drill string can be pushed or pulled into the ground by using an engaging element embodied as a locking pawl 4, which is fastened to a slide 50 that can move forward and backward relative to the frame. The locking pawl 4 engages in one of the grooves 5 of a rod section 6. The hydraulic cylinder 3 is acted upon, moving the locking pawl 4 accordingly, so that the drill string can be pushed into the ground. During the return stroke of the hydraulic cylinder 3, the locking pawl 4 tilts out of a groove 5 to fall into the next groove 5 when it is reached. Another feed cycle can then be initiated.

(9) The application of the hydraulic cylinder 3 can be controlled from a control panel 28. The control panel 28 has a pressure display 27 to provide pressure information or to set pressure by means of a hydraulic valve 26.

(10) FIG. 2 shows a section through a drilling head 7, by means of which the direction of the drill string can be controlled. The drilling head 7 is shown here in a state in which a straight introduction of the drill string can take place. The outer contour of a drilling head tip 9 at the front of the drilling head 7 forms an extension of the drill string. There is no angle between the drilling head tip 9 of the drilling head 7 and the longitudinal axis of the drill string.

(11) The drilling head tip 9 of the drilling head 7 has a bore 10 at an angle of 5° relative to the longitudinal axis X-X, which is not round over the entire circumference in a partial area of its length. By means of the bore 10, the drilling head tip 9 can be inserted onto a locating pin 13, mounted such that it can be rotated relative to the locating pin 13. The locating pin 13 can be rotated relative to the drilling head tip 9. By means of retaining pins (not shown), which can engage with a recess 12, the drilling head tip is secured on the locating pin 13 in the longitudinal axial direction. In the embodiment shown, the locating pin 13 also has an angle of 5° to the longitudinal axis X-X, so that the front side of the locating pin 13 forms an angle to the area 17 of the locating pin 13 that is aligned with the longitudinal axis of the drill string.

(12) In the position shown in FIG. 2, the angles of the bore 10 of the drilling head tip 9 and of the locating pin 13 are in congruent angular position, so the angular deviations of 5° each compensate for one another. The drilling head tip 9 is thus in an angular position that is suitable for a straight drilling path.

(13) The rear end of the locating pin 13 is guided in an adapter 14 and is connected to it via a transverse pin 15 such that rotational, pulling, and pushing movement are prevented. The transverse pin 15 is secured by a wear sleeve 16, which in turn is positively connected at its front end, such that it cannot rotate, to the locating pin 13. The wear sleeve 16 serves as replaceable wear protection.

(14) The adapter 14 has an elliptical bore 18 at the rear end in order to be coupled to a first drill rod, which is also elliptical. In the embodiment shown in FIG. 2, a plug connection, which is secured by means of a pin, is provided for connection to the rod section.

(15) A transmitter 19, which transmits electromagnetic waves to a receiving device in order to be able to determine the current depth and/or the position of the drilling head 7, is mounted in the adapter 14 for above-ground depth measurement and position determination. In the area of the transmitter 19 on the adapter 14, transmitter slots 20 are formed, through which the electromagnetic waves can exit.

(16) In FIG. 2, which depicts the first angular position for straight drilling, it is shown that the bore 10 has a stop surface or stop edge 11, on which a stop surface or stop edge 24 of the locating pin 13 rests.

(17) FIG. 3 shows the drilling head 7 that is depicted in more detail in FIG. 2 in a position, or (second) angular position, that is suitable for introducing a curved path to the drilling path in order to, for example, make corrections to the drilling path and thus to reach a predefined target. The locating pin 13, which has a second stop edge 24 in a partial area 23 of its length to the first stop surface or stop edge 24, is rotated relative to the drilling head tip 9, wherein the soil holds the drilling head tip 9 in position. As a result, the second stop edge 24 of the locating pin 13 arrives at the stop edge 11 of the bore 10 of the drilling head tip 9. The entire drill string, including the drilling head tip 9, can be turned in the direction intended for course correction via the stop edges 11, 24. The angles of 5° each add up to a total of 10° for the angle of the drilling head tip 9, which is shown in FIG. 3. The angles of the bore 10 of the drilling head tip 9 and of the locating pin 13 have been brought into opposite angular positions compared to the position shown in FIG. 2.

(18) Rotation of the locating pin 13 is achieved by attaching a rotary adapter 21 to the rear rod section 6, which is still to be inserted, with a ratchet 22, shown enlarged in FIG. 4. By means of a clockwise rotation of 180° of the entire drill string provided in the embodiment, as well as the components connected thereto in a rotationally fixed manner, as described above, with the adapter 14, the locating pin 13, and the wear sleeve 16, the entire drill string is rotated, wherein the drilling head tip 9 is prevented from rotating by the surrounding soil.

(19) To assist the operator with the control process or the deflection of the locating pin 13, a scale 25 in the form of the time or a roll angle is attached to the rotary adapter 21. After successfully completing the control process (i.e., a completed course correction with a corresponding run of the drill string by pushing it into the soil), the drilling head tip 9 in the illustrated embodiment can be set back to straight ahead (as shown in FIG. 2) by turning the entire drill string counterclockwise by 180°, whereby the locating pin 13 is rotated, and the drilling head tip 9 is in turn prevented from rotating by the soil.