Method for determining wear on a linkage of a ground drilling device

Abstract

A method for determining the wear on a linkage of a ground drilling device includes detecting a bending load of the linkage. The bending load is used to carry out a service life calculation.

Claims

1. A method for determining wear on a linkage of a ground drilling device, comprising detecting, in a ground bore by a sensor on at least one linkage section of the linkage, a bending load on the at least one linkage section and using the bending load to carry out a service life calculation for a plurality of linkage lengths of the linkage; wherein detecting the bending load by the sensor on the at least one linkage section in the ground bore comprises detecting, in the ground bore, the bending load by at least one expansion sensor arranged on a rod-shaped section of the at least one linkage section protected by a protective casing in which the rod-shaped section is arranged, wherein the rod-shaped section has a smaller cross-section than a cross-section of the plurality of linkage lengths of the linkage.

2. The method according to claim 1, wherein the expansion sensor comprises at least one of a wire strain gauge or a fiber-Bragg grating sensor.

3. The method according to claim 1, wherein the service life calculation is based in part on a position of the linkage length in the linkage.

4. The method according to claim 1, wherein the rod-shaped section of the at least one linkage section is in line with the linkage lengths.

5. The method according to claim 1, wherein the sensor on the rod-shaped section of the at least one linkage section is arranged on a middle portion of the rod-shaped section of the at least one linkage section.

6. The method according to claim 1, wherein the protective casing protecting the at least one linkage section is detachably fixed to the rod-shaped section of the at least one linkage section.

7. A ground drilling device, comprising a linkage and at least one linkage section connected to the linkage, wherein the at least one linkage section comprises an expansion sensor for measuring a bending load on the at least one linkage section when it is in a borehole, wherein a data connection can be established between the at least one linkage section and a receiving device to transmit the bending load measured on the at least one linkage section to carry out a service life calculation for a plurality of linkage lengths, where the sensor is arranged on a rod-shaped section of the at least one linkage section protected by a protective casing in which the rod-shaped section is arranged, the rod-shaped section having a smaller cross-section than a cross-section of the plurality of linkage lengths of the linkage.

8. The ground drilling device according to claim 7, wherein a signal from the sensor can be transmitted by the data connection to a control.

9. The ground drilling device according to claim 7, wherein the rod-shaped section of the at least one linkage section is in line with the linkage lengths on which at least one sensor is arranged.

10. The ground drilling device according to claim 9, wherein the rod-shaped section is hollow.

11. The ground drilling device of claim 7, wherein the protective casing is detachably fixed to the rod-shaped section of the at least one linkage section.

12. A method for determining wear on a plurality of linkages of a ground drilling device, comprising detecting, in a ground bore by a sensor on each of the plurality of linkages, a bending load on each of the plurality of linkages and using the bending loads to carry out service life calculations for a plurality of linkage lengths of the linkage; wherein detecting the bending load by the sensor on each of the plurality of linkages in the ground bore comprises detecting, in the ground bore, the bending load by at least one expansion sensor arranged on a rod-shaped section of each of the plurality of linkages, wherein each rod-shaped section is protected by a detachably fixed protective casing fixed to the rod-shaped section, wherein the rod-shaped section has a smaller cross-section than a cross-section of the plurality of linkage lengths of the linkage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in detail in the following using an exemplary embodiment shown in the drawings.

(2) FIG. 1 shows a ground drilling device in a schematic view;

(3) FIG. 2 shows an end area of the linkage of the ground drilling device in FIG. 1; and

(4) FIG. 3 shows a detailed view of a linkage section in FIG. 2.

DETAILED DESCRIPTION

(5) FIG. 1 shows a schematic view of a ground drilling device. The ground borehole device comprises a drive device 1 with two hydraulic cylinders 2 operated in parallel and whose piston rods 3 transmit a linear movement onto a linkage 6 of the ground drilling device via a pressure bridge 4 and the coupling element 5 associated with the latter. The transmission takes place step-by-step in that the hydraulic cylinders 2 of the drive device 1 cyclically execute a working and a return stroke.

(6) The ground drilling device with the drive device 1 is suitable for a pushing as well as for a drawing operation. The linkage 6 comprises a plurality of linkage lengths 8 connected to each other by couplings 7.

(7) The ground drilling device comprises a detection apparatus for detecting an instantaneous loading of the linkage which apparatus comprises a pressure sensor 9 and the linkage section 15 shown in FIG. 2 and FIG. 3 which is described in detail in conjunction with the FIGS. 2 and 3.

(8) Furthermore, the ground drilling device shown in FIG. 1 comprises an evaluation apparatus 13 for carrying out a service life calculation for the linkage.

(9) The hydraulic pressure in one or also in both of the hydraulic cylinders 2 can be measured by the pressure sensor 9. The hydraulic pressure is proportional to the forces of pressure and traction exerted on the linkage 6. The hydraulic pressure is transmitted to a computer unit of the evaluation apparatus 13.

(10) The ground drilling device additionally comprises a transmission apparatus 16 which comprises in the exemplary example shown a writing unit 10 and a reading unit 11. Data can be written to and read out from storage elements 12, of which one of them is fastened on each of the linkage lengths 8, by the transmission apparatus 16. The writing unit 10 as well as the reading unit 11 are connected to the evaluation apparatus 13.

(11) The ground drilling device makes it possible to determine the individual loads to which the individual linkage lengths 8 are exposed and to perform individual service life calculations from this. To this end the data stored on the corresponding storage element 12 (optionally at previous usages of this linkage length 8 which already took place) is read out by the reading unit 11 for each of the linkage lengths 8 shortly before the decoupling. Based on the work procedure in which the linkage length 8 was used, the load exerted on the linkage length 8 is determined by the evaluation apparatus 13, wherein the data of the pressure sensor 9 and of the data detected on the linkage section 15 is evaluated for the determination. Starting from these concrete values, an individual service life calculation can be carried out for each individual one of the linkage lengths 8 of the linkage 6 in the evaluation unit 13. The result of the service life calculation, in which in addition to the current working procedure even all previous loads of the particular linkage length 8 are considered, is again stored by the writing unit 10 on the storage element 12 of the particular linkage lengths 8, which element is designed as an RFID chip, so that this data is available again in a subsequent usage of the corresponding linkage length 8 and can be considered in a subsequent updating of the service life calculation. An appropriate service life calculation is carried out for each of the linkage lengths 8 of the linkage 6. Different results can result for all of the linkage lengths 8 depending on the position at which they are or were incorporated into the linkage 6. For example, the first linkage length 8 of the linkage 6 which is directly connected to the drilling head is loaded the longest since it is coupled on as the first linkage length and decoupled again as the last one (for example, when carrying out a pilot bore and withdrawing the linkage with a widening-out head).

(12) The following data can be stored on the RFID chip in one embodiment: production order number, average pressure, fissure check yes/no, Remaining service life total stroke number, stroke number per load horizon (8 times), total previous damage, most damaging load horizon, expected service life at full load, expected service life at an average load.

(13) In the embodiment of a ground drilling device shown in FIG. 1 the device comprises a monitor 14 on which the result of the service life calculation as it is stored during the decoupling of each linkage length 8 on the corresponding RFID chip is shown. This makes it possible for the user of the ground drilling device to read off the information shown there regarding the service life to be expected for the particular linkage length 8. As a result thereof, for example, linkage lengths 8 whose expected service life is no longer long enough for a subsequent use can be directly separated out. In addition, the individual linkage lengths 8 can be sorted according to their expected service life after the decoupling and appropriately stored. In this manner it is made possible, for example, in subsequent work projects to couple those linkage lengths 8 which have only a short expectation of service life late on the linkage 6 in order to keep the additional loads on these linkage lengths 8 low and/or to be able to rescue such a linkage length 8 rapidly and in a simple manner for the case that it is destroyed. There is also the possibility of providing a portable managing device which comprises at least an appropriate reading unit and a display. With this portable managing device the storage elements 12 of stored linkage lengths 8 can also be read out independently of the drive device 1 in order to be able to appropriately plan the future use of the individual linkage lengths 8. The read-out values can be used, for example, for an inventory or also for preparing renting lists, etc.

(14) FIG. 2 schematically shows an oblique rear view of a front area of the drill string with linkage lengths 8 and a drilling head 17. The transmitting section 18 with a transmitter is arranged between the drilling head 17 and the linkage lengths 8 which transmitter is followed by the linkage section 15. The transmitter in the transmitter section 18 serves to localize the drilling head 17 and for localizing the drill string. The drilling head 17 with following transmitter section 18 and linkage section 15 as well as the linkage lengths 8 follow the ground borehole which is carried out in the ground. The curvature of the course of the ground borehole can be detected with the linkage section 15. The linkage section 15 detects a bending load. The linkage section 15 is shown on an enlarged scale in FIG. 3. The linkage section 15 comprises a rod-shaped section 19 whose diameter is smaller than the diameter of the linkage lengths 8. The rod-shaped section 19 is surrounded by a protective casing 20 which substantially comprises an outer dimension corresponding to the dimension of drilling head 17 and transmitter section 18. The protective casing 20 protects the rod-shaped section, which is designed to be hollow. In particular, the protective casing 20 protects expansion sensors 21 arranged on the rod-shaped section 19 which are substantially fastened centrally as regards the longitudinal extension of the rod-shaped section 19 to the latter.

(15) The embodiment shown in FIGS. 2 and 3 shows a cable 22 for connecting to a receiving device 23 which transmits the data to a control of the ground drilling device or to the evaluation device 13. Instead of a cable 22 shown in FIGS. 2 and 3, a wireless transmission of the values of the expansion sensors 21 to the receiving device 23 can take place. The receiving device 23 is connected to the evaluation device 13 by cable or in a wireless manner. The receiving device 23 transmits the signals of the expansion sensor 21 to the evaluation device 13 in an evaluated form and/or in a raw version so that the evaluation device 13 can perform a service life calculation for the linkage and/or the individual linkage length 8 with inclusion of the data of the pressure sensor 9.