Patent Publication Number: US-7905300-B2

Title: Drilling device and drilling method utilizing dual drives

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a drilling device comprising a mast, a drilling carriage which is guided along the mast in a displaceable manner and a drive unit for moving the drilling carriage on the mast. 
     The invention further relates to a drilling method for producing a drill hole, in which a first rod and a second rod are moved and in particular introduced into the ground with a drilling carriage, which is guided on a mast. 
     2. Description of related art including information disclosed under 37 CFR §§1.97 and 1.98 
     In drilling devices of such type, which are employed in particular in deep-hole drilling, there are usually two main modes of operation. These comprise the drilling on the one hand and the lining of the drill hole with casing pipes on the other hand. The first main mode of operation, which claims the largest part of the operating time, serves for the drilling or extraction of drill rod segments. In this case the change of the rod segments has to take place rapidly because during this time the flushing of the drilling is interrupted. In doing so there is a risk of the drill head getting stuck. 
     On reaching a certain drilling depth the drill hole has to be lined with casing pipes and concreted against the soil externally in order to stabilize the drill hole and prevent a contamination of the various soil layers, as for example during gas or oil drilling. For this purpose rod segments of greater length are installed, connected to one another and then concreted from the outside. To this end the feeding system requires great tensile forces. 
     A drilling device, in which a telescopic mast can be moved by a hydraulic cylinder, is known from EP 0 114 146 A. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is based on the object to provide a drilling device and a drilling method, by means of which an efficient operation in the different main modes of operation is rendered possible. 
     In accordance with the invention the object is solved on the one hand by a drilling device having a mast, a drilling carriage which is guided along the mast in a displaceable manner, and a drive unit for moving the carriage on the mast, wherein the drive unit has both a hydraulic cylinder drive and a rope winch drive and the drilling carriage can be coupled with the hydraulic cylinder drive and with the rope winch drive; and on the other hand by a drilling method for implementation with such a drilling device, to produce a drill hole, in which a first rod and a second rod are moved and in particular introduced into the ground with a drilling carriage, which is guided on a mast, wherein for the introduction of the first rod the drilling carriage is moved with a hydraulic cylinder drive and for the introduction of the second rod the drilling carriage is moved with a rope winch drive. 
     The drilling device according to the invention is characterized in that the drive unit has both a hydraulic cylinder drive and a rope winch drive and in that the drilling carriage can be coupled with the hydraulic cylinder drive and with the rope winch drive. 
     With the two different drives it is possible to implement the different modes of operation in an efficient manner. The hydraulic cylinder drive permits high feeding and movement speeds, which prove to be especially advantageous during drilling or extraction of the drill rod segments. The rope winch drive, in turn, can be used effectively during the lining of the drill hole, for instance by introducing the casing pipes. For these operations a feeding system with high tensile forces is required. This can be achieved in a cost-saving and compact way by a rope winch drive, with which high tensile forces are made available at reduced feeding speeds in particular due to a multiple reeving of the hoisting rope in line with the chain block principle. 
     In principle, during both modes of operation the drilling carriage can be connected to both the hydraulic cylinder drive and the rope winch drive. However, according to the invention it is especially useful that a coupling device is provided, by means of which the drilling carriage can be connected alternately to the hydraulic cylinder drive and the rope winch drive. The coupling device can be operated manually, for example by insertable retaining bolts, or automatically, for example by corresponding hydraulic cylinders that actuate a lock mechanism on the drilling carriage. 
     According to the invention it is particularly preferable that the mast has a mast base element and at least one telescopic mast element, which is guided in a telescopic manner in the mast base element, and that for movement of the at least one telescopic mast element the hydraulic cylinder drive can be coupled with the former. In this manner the hydraulic cylinder drive can be used not only for movement of the drilling carriage but also for telescoping the mast. The telescopic facility of the mast proves to be especially useful for the set-up of the drilling device, in which case the mast is pivoted from a substantially horizontal transport position into the substantially vertical operating position. The smaller the dimension of the mast in this operation, the lower the raising forces required. Moreover, the extension of the mast is useful if, for the purpose of lining the drill hole after the drilling, casing pipes with rod segments are used, the length of which is greater than the length of the drill rod segments. 
     A high flexibility with regard to the movement path of the drilling carriage is achieved in accordance with the invention in that the drilling carriage has a first guide for guidance along the mast base element and at least a further guide for guidance along the at least one telescopic mast element. On account of its telescopic facility the telescopic mast element has a different shape, usually a smaller one than that of the mast base element. To ensure here a reliable guidance of the drilling carriage, the mast base element has a first guide that differs from the second guide on the telescopic mast element. These can be guide rails or guide grooves in particular. On the drilling carriage corresponding slide shoes or guide shoes are provided for the two guides so that when the mast is extended the drilling carriage can be moved without transition from the mast base element to the telescopic mast element. According to the number of telescopic mast elements provision can also be made for more than two guides. 
     Furthermore, provision is made in accordance with the invention for the rope winch drive to have a rope winch, which is arranged on the bed of the drilling device, and a rope, which is guided via a pulley arrangement on the mast head of the mast. With this arrangement high tensile forces can be applied via the mast head onto the drilling carriage. This applies in particular if the pulley arrangement provides for an additional force transmission in accordance with the chain block principle. The arrangement of the rope winch on the bed of the drilling device allows for a stable construction and a direct introduction of force into the stable bed of the device. 
     In this context, it is especially preferred that for the purpose of pivoting of the mast in or from the vertical, the rope winch drive can be connected to the mast. In this way the rope winch drive can also be used to raise the mast from the substantially horizontal transport position into the vertical operating position. To this end the rope has to be detached from the drilling carriage and attached to a point of attachment provided on the rear strut arrangement of the mast. 
     According to the invention a stable construction is fostered by the fact that the hydraulic cylinder drive has at least one hydraulic cylinder that is arranged on the base of the mast. In addition to the point of articulation located on the base of the mast the hydraulic cylinder has a further point of articulation that is detachably fixed on the drilling carriage. For the telescopic facility of the telescopic mast element the detachable fixing point of the hydraulic cylinder can thus be coupled to the telescopic mast element so as to retract or extend the latter. 
     The drilling method according to the invention is characterized in that for the introduction of the first rod the drilling carriage is moved with a hydraulic cylinder drive and for the introduction of the second rod the drilling carriage is moved with a rope winch drive. The hydraulic cylinder drive permits a quick movement which is especially advantageous for the inner drill rod segments. The rope winch drive in turn permits the application of high feeding forces, as required during the introduction of casing pipes. 
     In accordance with the invention it is of advantage that the first rod is an inner drill rod and the second rod is an outer pipe rod. On the ground-facing end of the inner drill rod the drill head is located. The outer pipe rod can be employed for lining and concreting the drill hole in order to secure it. 
     Furthermore, it is preferred according to the invention that the first rod is composed of first rod segments and the second rod is composed of second rod segments, that the first rod segments have a length that is smaller than the length of the second rod segments, that before the introduction of the second rod a telescopic mast element is extended on a mast base element for extension and that the second rod is introduced segment by segment into the ground by moving the drilling carriage along the extended mast. Alternatively, the segments of the first rod can also be longer than those of the second rod. 
     The drilling method according to the invention allows for an efficient operation in both main modes of operation. For example for the drilling with a drill rod the drilling carriage can be moved solely along the mast base element. In this case use can be made of shorter drill rod segments. If in the other main mode of operation longer casing pipes are used as second rod for instance for lining the drill hole, the mast can be extended for these longer rod segments. 
     According to the invention a drilling device and a drilling method are achieved in all, in which case the drilling device is much more cost-saving as compared to conventional drilling devices with a comparable performance. For, a considerably larger dimensioning of the rope winch drive would be required in order to reach with a rope winch drive both the high feeding speeds of a hydraulic cylinder and at the same time the necessary high feeding forces. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The invention will be described further by way of preferred embodiments which are shown schematically in the drawings, wherein: 
         FIG. 1  shows a perspective view of a first drilling device according to the invention; 
         FIG. 2  shows a side view of the drilling device of  FIG. 1 ; 
         FIG. 3  shows a perspective view of the drilling device of  FIG. 1  with a pivoted mast; 
         FIG. 4  shows a perspective view of a further drilling device according to the invention with equipment; 
         FIG. 5  shows a perspective view of a further drilling device according to the invention and 
         FIG. 6  shows a front view of the drilling device of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  show a first drilling device  10  according to the invention with a bed  12 , in which a container-shaped power unit  14  for the energy and hydraulic supply is arranged. At the opposite end of the bed  12  a fork-shaped ground support  16  is provided which extends around a drill hole frame  5 . On the legs of the fork-shaped ground support  16  a mast  23  is articulated in a pivotable manner by means of a V-shaped bipod  20 . On the rear side of the mast  23  that faces away from the drill hole frame  5  said mast is supported with respect to the bed  12  through a strut arrangement  18  with a so-called A-trestle. 
     On the transition of the mast  23  to the bipod  20  the substantially horizontally extending drilling table  22  with a box-shaped control station  62  is mounted. Below the drilling table  22 , which is supported by struts  21  with respect to the fork-shaped ground support  16 , a blowout-preventer  60  with corresponding clamping devices is provided in a known manner for screw-connecting and breaking the individual rod segments. 
     In the illustrated embodiment of the drilling device  10  the mast  23  is designed in a telescopic manner with a mast base element  24 , in which a telescopic mast element  26  is guided in a displaceable manner. The mast base body  24  and the telescopic mast element  26  have rail-like guides at their front sides, along which a drilling carriage  50  with a rotary head  52  is guided in a displaceable manner along the mast  23 . On the side directed towards the mast the drilling carriage  50  has guide shoes as a first guide  54  and a second guide  56 , which, together with the guide on the mast base element  24  or with the guide on the telescopic mast element  26 , respectively, provide a reliable linear displacement of the drilling carriage  50 . 
     In accordance with the invention the drilling carriage  50  can be moved both by a hydraulic cylinder drive  40  and by a rope winch drive  30 . The rope winch drive  30  has a drum-shaped rope winch  32  with a rotary drive. The rope winch  32  is arranged on the bed  12  between the fork-shaped ground support  16  and the power unit  14 . By means of a deflection pulley  34  located on the mast head  28  a rope not depicted here is connected via a pulley arrangement  36  along the mast  23  to the drilling carriage  50 . By way of a multiple reeving of the rope in the pulley arrangement  36  an increase in the tensile force according to the chain block principle is achieved in order to displace the drilling carriage  50 . To the same extent that the tensile force increases, the displacement speed of the rope winch drive  30  decreases. 
     According to the invention to achieve a quicker displacement in the case of lower tensile forces the drilling carriage  50  can be coupled with the hydraulic cylinder drive  40 . The hydraulic cylinder drive  40  has a hydraulic cylinder  42  that extends along the mast  23 , which is U-shaped in cross-section, in the inner space thereof. The hydraulic cylinder  42  has a lower point of attachment  44  and an upper point of attachment  46 . By way of these points of attachment  44 ,  46  the hydraulic cylinder  42  can be connected optionally to the base of the mast  23 , to the drilling carriage  50  or to the displaceable telescopic mast element  26 . 
     According to the invention the telescopic mast element  26  can be extended from the mast base element  24  for extension of the mast  23  especially in those cases where longer rod segments have to be drilled in or extracted. Depending on the desired feeding speed or the required tensile forces, the drilling carriage  50  can then be operated either by the rope winch drive  30  or by the hydraulic cylinder drive  40 . 
       FIG. 3  shows the drilling device  10  in the folded assembly position, in which the mast  23  is articulated by means of the pivot joints  17  located at the lower end of the bipod  20  to the fork-shaped ground support  16 . To raise the mast  23 , which is in its telescoped condition in order to reduce forces, the rope winch drive  30  can be employed. To this end the rope  33 , illustrated in part only, is articulated by means of the folded strut arrangement  18  to the mast  23 . In this way the mast  23  can be pivoted from its horizontal transport position into the vertical operating position and vice versa. 
     A further drilling device  10  is shown in  FIG. 4 . This drilling device  10  substantially corresponds to the previously described drilling device. Unlike the afore-mentioned device, a different strut arrangement  18  with a box-shaped intermediate element is chosen in this case. 
     The drilling device  10  according to  FIG. 4  is shown with the equipment commonly used at drilling sites. First rod segments  71  are pivoted by an as such known handling device  70  from a horizontal starting position into a vertical position and lifted on the level of the drilling table  22 . By means of the drilling carriage  50  the first drill rod segments  71  can be screw-connected to one another so as to form the first rod and introduced segment by segment into the ground. The dismantling of the first rod takes place in the reverse order. 
     In addition, a second rod composed of second rod segments  72  can be introduced with the drilling carriage  50 . In the illustration according to  FIG. 4  said rod segments are arranged in a pipe rod store. The length of the second rod segments  72  is greater than the length of the first rod segments  71 . For movement of the longer second rod segments  72  the mast  23  can be extended, as illustrated, so that the drilling carriage  50 , on being moved towards the upper mast head  28 , is also able to receive the second rod segments  72  and introduce them into the ground or extract them respectively. 
     In  FIGS. 5 and 6  a further drilling device  10  according to the invention is shown. This device substantially corresponds to the previously described drilling devices so that in the following only the varying construction of details will be depicted. 
     In the drilling device  10  according to  FIGS. 5 and 6  a single-piece mast  23  with a fixed mast length is provided. The length of the mast  23  is designed to match the largest anticipated length of a rod segment. In the case of shorter rod segments the drilling carriage  50  only moves up to the height in each case required on the mast  23 .