Patent Application
20080245571
The invention relates to an earth drilling device in accordance with the preamble of claim 1. An earth drilling device of such kind is designed with an auger, an encasing tube which surrounds the auger, a rotary drive for driving at least the auger in a rotating manner about a drilling axis, an ejecting device for discharging drill spoil from the auger, wherein the ejecting device has a discharge line for the drill spoil, and a mast element along which the auger can be moved together with the ejecting device.
A device for cased earth drilling is known for instance from JP 60-238516 A. In this known drilling device, an ejection opening is provided at the upper end of the encasing tube below the rotary drill drive, through which the drill spoil conveyed by the auger can emerge. From the ejection opening the drill spoil falls along the encasing tube next to the drill tube to the ground. Since the ejection of drill spoil takes place on a level with the rotary drive, a great height of drop is present especially at the beginning of the drilling when the rotary drive is still located at a large distance from the ground. Therefore, special safety measures may be required to prevent accidents caused by drill spoil being dropped. In addition, the largely uncontrolled ejection of drill spoil on a level with the rotary drive can lead to considerable pollution of the construction site.
A generic earth drilling device is known from JP 06-257363 A. In this drilling device a flexible discharge bag is provided at the ejection opening, which forms a discharge line for the drill spoil and guides the drill spoil when dropping down. An undirected swirling around of ejected drill spoil is thereby prevented so that the risk of accidents is reduced and pollution of the construction site is counteracted.
The discharge bag known from JP 06-257363 is designed such that it reaches to just above ground level when the drilling tool is withdrawn completely. This brings about a comparatively great length so that in windy weather conditions the fabric bag can move in an undesired way and get entangled in the device. Moreover, especially in the case of greater drilling depths a clogging of the bag may occur in particular if the drill spoil is humid and adheres to the bag.
The object of the invention is to provide an earth drilling device, which ensures a particularly secure, clean and reliable discharge of drill spoil.
The object is solved in accordance with the invention by an earth drilling device having the features of claim 1. Preferred embodiments are stated in the dependent claims.
The earth drilling device according to the invention is characterized in that a device for changing the length of the discharge line is provided.
A fundamental idea of the invention can be seen in the fact that the discharge line for the ejected drill spoil is provided in a length-adjustable manner. This renders it possible to adapt the length of the discharge line to the actual drilling depth, i.e. to shorten the discharge line during downward drilling, that is when the ejecting device is lowered to the ground together with the auger and/or the encasing tube, and to extend the discharge line again during withdrawal. As a result, this ensures that the end-side outlet opening of the discharge line is always located a bit above the ground, whereby prevention is made of the discharge line resting on the ground during downward drilling. In this way a continuous removal of drill spoil from the discharge line can be ensured even in great drilling depths, which in turn counteracts clogging of the discharge line. According to this aspect of the invention the change of the length of the discharge line is suitably accompanied by a change of the dimensions of the discharge line longitudinally to the drilling axis, i.e. longitudinally to the mast element. Moreover, according to the invention the wind influence sensitivity is reduced because parts of the discharge line that are not required temporarily can be telescoped so that the loads stemming from wind are decreased.
Basically, the discharge line can be designed e.g. as a slide that is open on one side. However, for a particularly reliable guidance of the ejected drill spoil it is of advantage that the discharge line is designed as a discharge tube. Through this an all-round guidance of the drill spoil is provided and an undesired swirling around of drill spoil is thereby prevented in an especially effective way.
A length change of the discharge line can be effected for example in that additional elements are attached to or removed from the line. If use is made of a flexible discharge line, such as a fabric hose, the line could be shortened e.g. through winding up or gathering. However, it is particularly advantageous for the discharge line to be telescopic. If the discharge line has a telescopic design the length change of the line can be carried out in a particularly simple and reliable manner. A telescopic design of the discharge line is of particular advantage if the discharge line is to be designed in a rigid manner in order to reduce wind influence sensitivity.
It is especially advantageous for the discharge line to have a plurality of tube elements which can preferably be telescoped in order to shorten the discharge line. Through this a telescopic function can be realized in an especially simple way.
Furthermore, according to the invention it is advantageous for the tube elements to narrow towards an end portion. This renders it possible for the tube elements of the discharge line to be provided, at least by approximation, with the same dimensions whilst realizing at the same time the telescopic function. The telescope-like retracting of adjacent tube elements into one another is ensured in this case by the narrowing portions of the tube elements. To allow for a particularly reliable guidance of the drill spoil the narrowing portions suitably run in such a way that the diameter of the tube elements decreases with an increasing distance to the rotary drive, i.e. normally towards the ground. If the tube elements are provided with narrowing portions the elements can if necessary also be referred to as a funnel on account of their shape, in which case the entire discharge line can then be referred to as a funnel chain. Particularly, for an especially simple production the narrowing portions are suitably conical taperings. Apart from narrowing portions in the tube elements a telescopic function of the discharge line can also be provided in that tube elements of different cross-sections are employed.
Another particularly preferred embodiment of the invention resides in the fact that the device for changing the length of the discharge line has at least one hoisting cable and that, in addition, the device for changing the length of the discharge line preferably has at least one winch device for changing the free length of the hoisting cable. As a result, a length adjustment of the discharge line is rendered possible in an especially simple and reliable manner. More particularly, a hoisting cable operation is comparatively insensitive to distortions and deflections of the discharge line which may occur for example due to wind load. Basically, e.g. a rack-and-pinion mechanism can also be provided for changing the length of the discharge line. With regard to force absorption it is of advantage that several hoisting cables, e.g. two hoisting cables, are provided, which then can have an own winch device each.
From a constructional point of view an especially simple mechanism for changing the length of the discharge line is given in that the hoisting cable is fixed to at least one of the tube elements. By preference, the hoisting cable is fixed to a tube element located at the end, i.e. in particular to a tube element arranged the furthest away from the rotary drive and/or the closest to the ground. In such case the discharge line can be telescoped along its entire length, and during shortening the tube elements arranged in the end portion of the discharge line, i.e. the lower tube elements located close to the ground, are telescoped first and gradually these elements take along the tube elements lying above. To increase the stability of the discharge line it is of advantage that the remaining tube elements are each guided on the hoisting cable in a longitudinally movable manner. To this end, it is suitable for the tube elements to have guide openings, through which the hoisting cable is guided so that the tube elements can be moved freely along the hoisting cable. In this case the hoisting cable serves not only for holding a tube element but also for laterally stabilizing the remaining tube elements disposed above.
Additionally or alternatively, provision can be made for the hoisting cable to run through guides on the tube elements, and below these guides the hoisting cable has a respective engaging piece in the form of a cable rest. This renders it possible that the distances between the individual tube elements become shorter upon a decreasing of the free length of the hoisting cable and that the individual tube elements slide into one another.
With regard to the reliability of the earth drilling device according to the invention it is especially advantageous that means are provided that limit travel during the extension of adjacent tube elements. For this purpose e.g. stop elements can be provided on the tube elements which limit an axial relative movement of the individual tube elements with respect to one another. For example on the upper side of the tube elements a radially protruding stop element can be provided, which, on reaching maximum extension travel, comes to rest against a radially inward protruding stop element of the tube element lying above. However, it is particularly preferred that adjacent tube elements are each connected to one another by at least one retaining cable. By preference, the retaining cable is fixed thereby to the opposite lying ends or to the respective upper end of adjacent tube elements. It is particularly suitable for adjacent tube elements to be connected to one another by three retaining cables each, which are distributed equidistant along the periphery of the tube elements. By limiting the axial movement of adjacent tube elements, e.g. through retaining cables or stops, prevention can be made of undesired interspaces occurring during extension of the discharge line between adjacent tube elements, from which drill spoil might emerge.
It is especially useful that the ejecting device has a collecting container which preferably surrounds the auger. The collecting container, which can have a cylindrical design in particular, suitably serves to receive drill spoil from the auger and to deliver it to the discharge line. Preferably, the collecting container is arranged at the upper end of the encasing tube, i.e. at the end facing away from the ground, and/or at the underside of the rotary drive.
It is particularly advantageous for an ejecting chute to be provided on the collecting container for supplying drill spoil to the discharge line. This allows for an especially reliable transfer of drill spoil from the collecting container to the discharge line. To permit a gravity-based supply the ejecting chute is preferably directed away from the collecting container in the downward direction. For best suitability the ejecting chute ends above the uppermost tube element of the discharge line so that drill spoil can be fed in a simple manner into the discharge line.
For best suitability the encasing tube and the auger are provided in a rotating manner relative to the collecting container. To permit a passage of drill spoil from the auger to the collecting container at least one through-hole is suitably provided in the encasing tube on a level with the collecting container. The collecting container can have a closure device, by which a passage of drill spoil from the collecting container to the ejecting chute and/or to the discharge line can be blocked selectively.
If the drill string with the auger and the encasing tube is drilled down to a large depth, the collecting container is normally located only just above the ground so that the discharge line telescoped to minimal length would perhaps also rest on the ground and a controlled ejection of drill spoil would then be no longer possible. To prevent this in particular it is of advantage that a lifting device is provided, by means of which the discharge line can be moved, in particular together with the winch device, relative to the rotary drive and/or the ejecting device for example in the direction of the drilling axis. More particularly, the lifting device renders it possible to lift the discharge line in its entirety when the drill string is drilled down to a large depth and thereby prevent ground contact. If the drill string is drilled down to a large depth, provision can be made for the drill spoil to be no longer ejected via the discharge line but discarded directly from the collecting container because in this case the dropping distance for the drill spoil is only comparatively short. For this purpose the discharge line can be moved by means of the lifting device in the upward direction and/or perhaps also in the radial direction and/or in the circumferential direction so that drill spoil from the collecting container is no longer passed on to the discharge line.
The lifting device suitably has a crane device, by which the discharge line can be lifted and/or pivoted together with the winch device. By preference, the crane device is fixed to the collecting container, especially below the rotary drive.
Furthermore, in accordance with the invention it is advantageous that a control is provided which is adapted to set the length of the discharge line as a function of the position of a feed drive for the auger and/or the ejecting device. According to this embodiment the length of the discharge line, and therefore its dimension in the drilling direction, is adjusted automatically to the feed of the drill string and therefore to the position of the collecting container above the ground, whereby ground contact of the discharge line is counteracted automatically. It is suitable for the discharge line to extend at least approximately parallel to the drilling direction, i.e. at least approximately longitudinally to the mast element.
For best suitability the rotary drive is a twin-head rotary drive, by which both the auger and the encasing tube can be set into rotation, by preference independently of each other. To this end the rotary drive suitably has two separate drive units. The collecting container is appropriately arranged below the lower drive unit provided for driving the encasing tube.
The invention also relates to a method for producing a borehole in the ground with an earth drilling device in accordance with the invention, in which the auger is set into rotation about the drilling axis by means of the rotary drive and is moved together with the ejecting device in the direction of the drilling axis in the ground, and in doing so the length of the discharge line is adapted in the direction of the drilling axis. By making use of the earth drilling device according to the invention the advantages set out in this connection can be realized.
In the following the invention will be described in greater detail by way of preferred embodiments shown schematically in the accompanying drawings, wherein:
As shown in particular in
On the mast element 3 a feed drive 41 designed as a winch drive is provided, which is connected via a cable pull mechanism with the rotary drive 20. Through operation of the feed drive 41, the rotary drive 20 can be moved together with the auger 4 and the encasing tube 5 both arranged on the said rotary drive in the longitudinal direction of the mast element 3, that is in the direction of the drilling axis 1, so that the auger 4 and the encasing tube 5 can penetrate into the ground 8. During penetration of the ground 8 soil material is stripped by the auger 4 which is conveyed from the auger 4 inside the encasing tube 5 towards the rotary drive 20 in the upward direction. To discharge the stripped soil material from the auger 4 an ejecting device 10 is provided.
The ejecting device 10 has a collecting container 30. The said cylindrically designed collecting container 30 is arranged on the rotary drive 20 below the lower, second drive unit 25 of the rotary drive 20. The collecting container 30 surrounds the encasing tube 5 and the auger 4 arranged inside the latter. The said container serves to receive drill spoil that is conveyed during drilling operation from the auger 4 in the upward direction inside the encasing tube 5 in the direction of the drilling axis 1. In the part of the collecting container 30 the drill spoil is delivered through openings in the encasing tube 5 from the auger 4 into the collecting container 30.
As can be seen in
As depicted furthermore in
As depicted especially in
As illustrated furthermore in
For operation of the hoisting cable 18 a winch device 19 is provided. As shown in particular in
Moreover, as depicted in
The winch device 19 permits a selective length change of the discharge line 11. If the first hoisting cable 18 and the second hoisting cable not shown here are wound up by means of the winch device 19, the hoisting cables hoist the lowermost tube element 14. On its way upwards the lowermost tube element 14 successively takes along the remaining tube elements 14′ 14″ etc. until the discharge line 11 is eventually telescoped completely, as depicted in
For automatic operation of the winch device 19 a control 40 is provided, which sets the length L of the discharge line 11 longitudinally of the drilling axis 1 as a function of the position of the feed drive 41 and therefore of the position of the auger 4 and the encasing tube 5.
As can be taken from
The drilling device shown in
At the beginning of the drilling operation the encasing tube 5 and the auger 4 are located over-ground 8 and the discharge line 11 is extended completely, as illustrated in
During introduction of the auger 4 with the encasing tube 5 into the ground the collecting container 30 as well as the discharge line 11, which are fixed to the upper side of the encasing tube 5, are lowered, too. To prevent the discharge line 11 from resting on the ground 8 during lowering the length L of the discharge line 11 is reduced with an increasing drilling depth by means of the control 40. To this end the control 40 operates the winch device 19, which in turn causes the tube elements 14, 14′, 14″ to 14n to be hoisted by the hoisting cable 18, starting with the lowermost tube element.
Upon an increasing drilling depth the single tube elements 14, 14′, 14″ to 14n are telescoped more and more so that eventually the discharge line 11 reaches the minimum length as set in
In order to prevent the discharge line 11 from resting on the ground 8 due to its remaining length during continued downward drilling, the line 11 is subsequently lifted in its entirety by the lifting device 35 and moved away from the ejecting chute 33, as shown in
The invention, which has been described by way of example in conjunction with vertical drilling can also be applied to inclined drilling and basically also to horizontal drilling, in which case an arrangement on the upper side can be understood as an arrangement facing away from the drilling ground.
| Number | Date | Country | Kind |
|---|---|---|---|
| 07 007 186.5 | Apr 2007 | EP | regional |
