WO1989005391A1

WO1989005391A1 - Device for drilling essentially vertical boreholes

Info

Publication number: WO1989005391A1
Application number: PCT/DE1988/000744
Authority: WO
Inventors: Heinz Peter Vogts; Albrecht Heinrichs; Peter Heinrichs
Original assignee: Wirth Maschinen- und Bohrgeräte-Fabrik GmbH
Priority date: 1987-12-09
Filing date: 1988-12-01
Publication date: 1989-06-15
Also published as: EP0349610B1; DE3741717A1; ZA889243B; EP0349610A1; AU2715588A; DE3868322D1

Abstract

A device for drilling essentially vertical boreholes has a guide part (22), which can be fastened to the borehole wall by means of a clamping device, and a working part (21) with a drilling tool (1) which moves relative to the guide part (22). The clamping device comprises clamping pieces (10) which can be moved radially on two clamping planes (AE, BE) by linear drives (14), and forms, at least partly, an adjustment device for adjusting the guide part (22) in a predetermined direction, in order to rapidly re-establish the verticality of a borehole. Each linear drive (14) can be controlled separately in at least one clamping plane. Displacement-measuring devices (47) are connected, at least in part, to the linear drives (14). The clamping device also comprises an actuating system and a separate release device (72, 74, 75, 82, or 92, 83 or 93).

Description

Device for drilling substantially vertical bores

T e c h n i s c h e s G e b i e t

The invention relates to a device according to the preamble of claim 1.

State of the art

A known device of this type (DE-PS 31 03 336) has, in addition to a tensioning device with clamping pieces which can be pushed out and retracted in two planes, an adjusting device with support members which can be moved inwards and outwards and which is separate from the tensioning device. The adjusting device is located on a part that is movable relative to the tensioning device. The support members of the adjusting device are arranged in a third plane at a distance from the two bracing levels. In one embodiment of the known device, the drilling tool can be rotated by means of a drill rod forming the supporting strand.

In shaft drilling machines which are suspended from a rope as a supporting strand, it is also known to provide a rotary drive for the drilling tool in the machine. D arste l__. invention

The object of the invention is to take particularly good account of the requirements of practice, in particular with regard to economy and safety, in a device for drilling substantially vertical bores, primarily large-hole bores. This means, among other things, that the device should be controllable as effectively as possible in order to maintain or quickly restore the verticality of a bore. This is to be achieved without having to take any special precautions in an additional setting level. The device should be suitable for use in different formats, e.g. can work in loose rock as well as in hard rock. Finally, precautions should be taken to ensure that the device also in the event of difficulties, particularly in the area of the transmission of signals, control commands and the like. as well as the energy supply, must not be lost. Further problems connected with all, with which the invention is concerned, result from the respective explanation of the indicated solution.

In a device of the type mentioned at the outset, the invention provides that the tensioning device is at least partially designed as a one-piece device, that each linear drive is individually controllable in at least one tensioning level, that the linear drives are at least partially assigned displacement measuring devices with display elements on the control station are and that for the tensioning device in addition to an 'actuation system, a separate loose device is available.

Such a device is characterized by a number of essential advantages. The fact that at least part of the bracing device is at the same time designed as a device for setting the direction is unnecessary adjusting means on a part movable with the drilling tool in a third plane. This contributes significantly to operational safety and also opens up special work opportunities. A separate loose device for the tensioning device ensures that the device is not lost, but can be brought out of the borehole by means of the load-bearing strand if control lines, signal transmitters, energy supply systems or others for normal operation are tensioned necessary parts of the tensioning device and / or adjusting device are defective or damaged, break or can no longer fulfill their function for other reasons.

Depending on the circumstances and requirements of the application, it may be sufficient to design the bracing device as part of the adjusting device only in one of the two bracing levels at the same time. In many cases it is advantageous to use both bracing planes for a directional adjustment of the guide part of the device. All the linear drives in the two bracing planes are then expediently controllable and equipped with displacement measuring devices.

With the device, a versatile work and thus an adaptation to different needs is possible. It can in particular be carried out in such a way that the device is brought into a position hanging on the supporting strand with the drilling tool at a standstill, that the guide part of the device is first adjusted in the desired direction and that the final bracing is then carried out while fixing the predetermined guide direction . It is also possible to change the setting and thus the drilling direction within certain limits even during drilling. An example of the course of a drilling operation will be explained further below in the second part of the description.

If both bracing levels are designed as adjustment levels at the same time, there are particularly versatile possibilities for setting the direction of the guide part of the device. The result is an exactly definable pivot point for the direction setting. This is of particular importance when drilling in loose rock if there is free space in the area of the drill head.

In an expedient embodiment, the clamping pieces in one bracing plane are offset from one another by an angle in the direction of extension in relation to the clamping pieces of the other bracing plane. This offset angle is advantageously half as large as the angle of the distance between the clamping pieces. If there are four clamping pieces in one plane, which are 90 ° apart, the offset angle is 45 °. This results in a very safe support and also a protection of the borehole wall, because there is no danger that the clamping pieces of one level will reach approximately the same point when the device for the next drilling stroke is added, at which the clamping pieces of the other level have already applied .

A rope or a similar traction element can be provided as the supporting strand on which the device is held from above days. In many cases, a linkage as a supporting strand is particularly advantageous. Above all, such a linkage can form a conveying path for drilling material. This applies primarily to the implementation of the air lifting drilling method or other indirect flushing drilling method for which the device is specially designed in appropriate training. If the load-bearing strand is a rope, a separate conveyor line must be available for the drill material. In the case of a rod as a supporting strand, this can be driven in rotation from a device located above for days so that it conducts a torque to the drill head. The linkage can in particular be non-rotating, in which case a drive for the drill head is arranged in the device.

The basic feature of the separate loose device for the tensioning device is that with this device the tension is released even if it is no longer possible to release from the tensioned state with the operating system normally provided for operating the tensioning device and / or the adjusting device is. This can e.g. be the case when a signal or control line, a power cable or the like. broken, a switching element has failed, or another impairment has occurred.

The separate loose device can be designed in various ways depending on the other design of the device. In an advantageous embodiment, the loose device has an energy store and at least one switching or control element for effecting the release process. The energy storage device makes the device independent of an external energy supply, so that a release of the tension is still possible if the device can no longer be supplied with energy from above days, for example if the energy supply line has been destroyed by unexpected influences .

To increase the overall safety, it may be appropriate to make the training so that actuation of the tensioning device for the guide part of the device tion is only possible with previously filled energy storage. This ensures that the separate loose device is ready for operation before the device begins to work. This is a very important feature.

The training is in particular such that the switching or control element of the release device automatically causes the release process when predetermined conditions occur, for example in cases of the aforementioned type. The energy from the memory can then immediately be supplied to those organs by means of which the tensioning of the guide part of the device can be released.

If it is a hydraulically operating clamping device with linear drives in the form of cylinder-piston units, the separate loose device expediently contains a hydraulic accumulator and a valve device by means of which all cylinder-piston units of the clamping system are released in the sense of a radial for the release process Inward movement of the clamping pieces can be actuated. The valve device in particular has a directional valve which can be automatically returned to a position suitable for effecting the release process.

A displacement measuring device is advantageously provided, by means of which the respective relative movement between the working part and the guide part can be detected. In this way, the condition in question or the current process can be checked well for days. Among other things, it is determined whether the guide part slips on the borehole wall, e.g. when easing by means of the load-bearing strand.

A safety system is assigned to the position measuring device, in particular in the sense of a drive over Fuse. In this way, it can be prevented at the lower stroke end that the drill head comes too deep. When moving, the risk of tearing is avoided. This will be dealt with in the further part of the description.

Between the working part and the guide part there are expediently lifting drives by means of which the two parts can be displaced relative to one another, be it in the sense of merely making up for it, or for applying an additional pressing force. A displacement measuring device is advantageously assigned to at least one lifting drive, in particular in connection with a safety system for preventing undesired or improper movements and operating states and / or for causing processes or actuations of parts or systems of the device in a sense that damage or Destruction can be avoided. Explanations are also given in the following part of the description.

Further details, features and advantages of the invention will become apparent from the following description of exemplary embodiments, which likewise belongs to the description of the invention, from the associated drawing and from the claims. Show it:

1 shows a device according to the invention in view,

2 shows the device according to FIG. 1 on a larger scale, predominantly in a section running along the line II-II in FIG. 4,

3 shows a section along the line III-III in FIG. 2, 4 shows a section along the line IV-IV in FIG. 2,

5 largely schematically shows a hydraulic actuation system for the bracing and adjusting parts of the device with display and control elements on a control station or the like,

Fig. 6 shows a special embodiment of a hydraulic actuation system, largely schematic and

7 shows a partly schematic illustration of a lifting drive between the guide part and the working part with further elements.

FIGS. 1 to 4 show an embodiment of the device which is used to drill directed vertical bores, in particular using the so-called air lifting drilling method. The device can work under water and is suitable for boring holes with a diameter of, for example, 2100 mm, to depths that can be 1000 m and more.

The number 1 denotes a drilling tool in the form of a drilling head which is equipped with roller chisels 2, cutting rollers or the like. is provided. The drilling head 1 is connected to a drive shaft 3, which in the advantageous embodiment shown can be rotated by means of a drive unit 18. The latter can contain one or more hydraulic motors. In particular, the drive unit has an electrically driven rotary head 19 with storage. From the drive unit 18, a non-rotatable hollow rod 4 extends upwards, along which air lines 11 run in this embodiment for the implementation of the air-lifting drilling method. These air lines 11 end in a connecting part 12, in which there are passages opening into the interior of the linkage 4, such that the air supplied from above can enter the interior of the linkage 4 at this point. The drive shaft 3 forms a continuation of the linkage 4 via the power turret 19. Like the latter, it is hollow and is connected to a suction nozzle or inlet channel 5 provided in the drilling head 1. Thus, flushing loaded with drilling material can enter the hollow drive shaft 3 and via the power turret 19 get into the linkage 4 and are promoted upwards.

A cable 6 also runs along the linkage 4 and is inserted into a pressure-tightly encapsulated distributor unit 7. The cable 6 contains measurement, control and power supply lines, such as also the power supply for the drive unit 18 and for motors for driving pumps in a hydraulic system to be explained. Energy, measuring and control lines leading from the distribution unit 7 to such and other units are only indicated schematically in FIG. 2 at the number 8.

The device contains an inclinometer 25 (FIG. 2) working in two measuring planes X and Y at an angle of 90 ° to one another, for example a so-called inclinometer via a measuring line 9, this device 25 is connected to the distributor unit 7 and via this to one Control station connected by day leading cable 6. There it can thus be determined at any time whether or in which direction and by what amount the bore or its section produced differs from the vertical.

In terms of the basic structure of the device, two parts can be distinguished, namely, on the one hand, a working part, designated overall by the number 21 and on the other hand a guide part, designated overall by the number 22.

The working part 21, which can also be referred to as an "inner kelly", includes, inter alia, a lower bearing system 15 for the drive shaft 3 with a connecting flange 20 for the drill head 1, said drive unit 18 and housing parts 17 with various internals. In addition to the distributor unit 7 and the inclinometer 25, the working part 21 accommodates load weights 13, containers for electrical and hydraulic components, a tank for a hydraulic medium, pumps and other parts, which are used to explain the mode of operation of the device and the description of others Details still to be mentioned.

The entire bearing system, namely the lower bearing 15 and the upper bearing in the rotary head 19, is designed to be pressure-compensated with its lubricant supply. Due to the load weights 13 and the other components of the working part 21, at least a substantial part of the pressing force for the drill head 1 is generated when working the same via the bearing system 15. If desired, an additional pressure force can be applied via the linkage 4 and / or other devices to be explained.

The guide part 22, which can also be referred to as an “outer cell”, has a casing or a housing 26 and contains a bracing device with linear drives 14 arranged in two bracing planes AE and BE, by means of which plate-like clamping pieces 10 can be moved radially outwards and inwards.

The load weights 13 are designed and assembled so that they interact with the guide part 2 ^* 2, to ensure proper directional guidance for the working part 21 in the tensioned operating state. Advantageously, there are guide strips 16 made of a suitable material, which are attached either to the guide part 22 or its housing 26 or to the working part 21 or components thereof, for example to the load weights 13, and slide on surfaces on the opposite side in question. As can be seen particularly in FIG. 3, such guide strips 16 can each be provided at locations which are adjacent to the linear drives 14. They can extend over the entire length of the guide part 22 or, in particular, can also be provided only at the upper and lower ends. The latter is the case in the illustrated embodiment of the device.

Between the guide part 22 and the working part 21, two axial movement units 27 are provided parallel to the longitudinal axis L of the device (FIGS. 2, 4 and 8), hereinafter referred to as lifting drives, by means of which the guide part 22 and the working part 21 relative to one another in the direction of the longitudinal axis L of the device are displaceable. (The section in FIG. 2 is such that only one of these lifting drives can be seen there.)

The linear drives 14 of the upper bracing plane AE used to extend and retract the clamping pieces 10 can be offset in relation to those of the lower bracing plane BE in the circumferential direction by 45 ° to one another, as can be seen in FIG. 1, or else without such an offset be arranged differently, as shown in Fig. 2.

Hydraulic cylinder-piston units are provided as linear drives in the advantageous embodiment shown, which are referred to below for the sake of simplicity as hydraulic units. The However, the invention is not limited to such hydraulic units. Rather, all types of linear drives that are suitable for the function can be provided. The same applies to the linear drives 27.

As already mentioned above, the hydraulic supply system with a tank for pressure medium, pump with drive, control elements and other parts required for the operation is accommodated in the device. In the following, explanations of control and operating systems are explained in more detail.

5, the parts which are the same as or correspond to those in the embodiment according to FIGS. 1 to 4 are designated by the same reference numerals as there, with the exception of the linear drives 14, which are now used for better explanation of the upper level AE with AI, A2, A3 and A4 and for the lower level BE with B1, B2, B3 and B4.

5 are the hydraulic units A1, A2, A3, A4 of the upper bracing plane AE and in the left outer part of FIG. 5 the hydraulic units B1, B2, B3, B4 of the lower bracing plane BE ( with a 45 ° offset in the circumferential direction, see FIG. 1). The inclination measuring device is illustrated by the number 25 with a dash-dotted boundary, the measurement in the two planes X and Y being indicated by the symbolic representation of a pendulum in side and front view.

Furthermore, part of a control stand ST located at a suitable point above ground with various display and actuation or control elements is shown with dash-dotted delimitation. In Fig. 5 hydraulic lines are drawn with solid lines and electrical signal or control lines each with dashed lines. The number 23 indicates plug connections or other detachable connections in these lines.

Hydraulic fluid can be conveyed from a tank 30 through a suction line 31 by means of a pump 34 which can be driven by a controllable motor 33 via a line 32 in two lines 35 and 36. The line 35 leads to a distributor block VA for the upper bracing plane AE and the line 36 to a distributor block VB for the lower bracing plane BE. Each of these two distributor blocks contains, from the control station ST, solenoid valves MA and MB to be actuated via control cables 37, 38, such that each hydraulic unit AI to A4 of the upper level and each hydraulic unit Bl to B4 of the lower one are used by means of these solenoid valves Level for itself in the sense of extending the clamping pieces 10 can be controlled.

For this purpose, hydraulic lines 41, 42, 43, 44 lead from the solenoid valves in the distributor block VA to the large cylinder spaces All of the units of the upper level AE and likewise from the solenoid valves in the distributor block VB hydraulic lines 51, 52, 53, 54 the large cylinder rooms B1 of the lower level BE. The small cylinder spaces A12 of the units of the upper level AE are connected by individual lines to a common line 45 going to the distributor block VA. Likewise, the small cylinder spaces B12 of the units of the lower level BE are connected by individual lines to a common line 55 going to the distributor block VB. Numbers 46 and 56 designate outflow lines leading from the distributor blocks VA and VB to the tank 30. It follows from the foregoing that in each of the two planes AE and BE each clamping piece 10 is individually moved radially outward, that is to say are extended. can, while on the other hand all clamping piece 10 is moved together or simultaneously radially inwards in each plane, that is to say can be retracted. For this purpose, the person skilled in the art has the necessary hydraulic and electrical components with their circuit options available, so that there is no need to go into them in detail here.

At the control station ST there are control switches AS1, AS2, AS3, AS4 for the units AI to A4 of the upper level AE and control switches BS1, BS2, BS3, BS4 for the units B1 to B4 of the lower level BE, by means of which each of the units for itself can be operated in the sense of extending. Control switches AR and BR serve to actuate the units of each level in the sense of the common retraction. Finally, there is a further control switch ABS, the function of which will be explained later.

Each unit AI to A4 of the upper level AE and each unit B1 to B4 of the lower level BE is assigned a path measuring device, by means of which the path covered by the clamping pieces 10 or their piston rods or other parts connected therewith is detected and for each Unit can be displayed separately on the control station ST for days on analog or digital display instruments Gl to G4. With appropriate calibration of the displacement measuring devices, the radial position of each clamping piece measured from a reference position can be read directly from these instruments.

Such measuring devices are available to the person skilled in the art in various designs. In the right Half of FIG. 5 are schematically indicated measurement sensors 47, which are connected to a processing unit 48 via signal lines. A signal cable 49 leads from this to the above-mentioned display instruments G1 to G4.

In the left half of FIG. 5 it is shown that the large cylinder spaces B1 of the units B1 to B4 via lines 57 and 58 with hydraulic-electrical transducers 59 and 60 for measuring the pressure and thus for determining the respectively on a clamping piece 10 acting contact pressure are equipped. Controllable shuttle valves 61, 62 are provided in the lines leading from the units B1, B3 and B2, B4 to the transducers 59, 60. This makes it possible to selectively connect one or the other of two opposing cylinders for pressure measurement to the associated transducer 59 or 60. However, a measured value sensor can also be provided for each cylinder. Each measured value on 59, 60 is connected to a display instrument P1 or P2 for the pressure. At the control station you can read the force with which the respective clamping piece is pressed against the borehole wall. By means of the hydraulic system, the contact pressure can therefore be selected individually for each unit in accordance with the requirements and conditions, taking into account the pressure display. This is particularly important when drilling in different formations. For example, when penetrating loose layers, the contact pressure should be lower than in the rock.

Because of the clarity of the illustration, the path measuring and display system 47 to 49, Gl to G4 in FIG. 5 is only for the upper level AE and the pressure measuring and display system 57 to 62, Pl, P2 is only for the lower level BE reproduced. In fact, the explanation ter advantageous embodiment in each of the two levels AE and BE for each unit AI to A4 or Bl to B4 measuring and display systems for path and pressure are available.

The inclination measuring device 25 is connected via lines 24 to display instruments NX and NY at the control station ST, so that the inclination of the device in the X-plane and in the Y-plane can be read with positive or negative values at any time.

The number 66 in FIG. 5 indicates actuators for the lifting drives 27 for displacing the guide part 22 and the working part 21 relative to one another. Advantageously, these stroke drives 27 also include displacement measuring devices with display instruments 67 on the control station ST, so that their operation can also be checked there. An advantageous training will be explained further below.

FIG. 6 illustrates a particularly advantageous embodiment of the device in which a separate loose device is provided for the tensioning device in addition to an actuation system. At the same time ^'this figure can detect system also other parts of Betätigungs¬. Parts which are the same as or correspond to those of the embodiment according to FIG. 5 have the same reference numerals as there.

The delivery line 32 of the pump 34 is connected, on the one hand, via an adjustable pressure relief valve 70 to the lines 35 and 36 leading to the distribution blocks VA and VB, so that pressure medium can flow to the distribution blocks, as shown in FIG. 5. In addition, the conveying line 32 is connected via a check valve 71 to a solenoid valve 72 Line 73 connected. A hydraulic pressure accumulator 75 and a pressure switch 76 are connected to the latter via a line 74 and, when a predetermined pressure in the pressure accumulator 75 is reached, emits a signal which is used in a manner to be explained. When the device is operating properly, the solenoid valve 72 is not in the position shown in FIG. 6, but in the other of its two possible positions. It is held in this position until either a conscious switchover of the valve into the position shown is effected from the control position ST or until it is automatically transferred into this position when certain predetermined conditions occur.

In the position of the valve 72 shown, pressure medium can flow from the pressure accumulator 75 via a line 81 and a check valve 82 to a manifold 83 to which the small cylinder spaces A12 of the units AI to A4 of the upper level AE are connected. Likewise, pressure medium can flow via a line 91 and a check valve 92 to a manifold 93, to which the small cylinder spaces B12 of the units B1 to B4 of the lower level BE are connected.

A line 84 or 94 is also connected to each manifold 83 or 93, in which an unlockable check valve 85 or 95 is arranged. These lines 84 and 94 come from solenoid valves which are located in the distributor block VA and VB and have connections to the pressure lines 35 and 36 and to the outflow lines 46 and 56 to the tank 30.

As also explained in connection with FIG. 5, hydraulic lines 41 to 44 lead from the distributor block VA for the upper level AE to the large cylinder spaces of all of the units AI to A4 of the upper level AE. In these Lines each have unlockable check valves 41a to 44a (FIG. 6), of which a common switching line 88 leads to a shuttle valve 77. The hydraulic lines 41 to 44 start from the solenoid valves housed in the distributor block VA, which can be counted among the solenoid valves generally designated MA in FIG. 5 and which each have connections to the pressure line 35 and to the drain line 46 to the tank 30. These solenoid valves can be actuated individually from the control position, specifically via control switches, as are also shown in FIG. 5 at control position ST at reference numerals AS1 to AS4. Lines leading from non-return valves 105 to 108 lead from the hydraulic lines 41 to 44. These check valves are connected on their outlet sides to an actuating line 109 leading to the unlockable check valve 85 in order to open this and thus allow hydraulic fluid to flow out of one or more of the small cylinder spaces A12 of the units AI to A4, if one or Several of the large cylinder spaces are all supplied with pressure medium by actuation of one or more of the solenoid valves - in order to extend the clamping piece 10 concerned.

While it is thus possible to actuate each unit AI to A4 in the sense of extending a clamping piece 10, it is sufficient to provide a common actuation of the units on one level for the retraction of the clamping pieces. In normal operation, this retraction takes place in that a further solenoid valve of the valve block VA is brought into such a position (for example by actuating the switch AR at the control station ST, FIG. 5), that the pressure medium via this solenoid valve, a line 111, the check valve 85 and the line 83 flows to the small cylinder spaces A12 and the pistons of the units AI to A4 in the sense of Moving in. The pressure in a line 112 branching from line 111 also adjusts the shuttle valve 77, which is also connected to the latter, in such a way that pressure medium can flow via the switching line 88 to the unblockable check valves 41a to 44a, in order to pass them from the large cylinder spaces and then open through the valves of the valve block VA to the outflow line 46, so that an unpressurized outflow of hydraulic fluid can take place in this way.

What has been said above for the actuation of the units AI to A4 of the upper level AE applies analogously and accordingly to the actuation of the units B1 to B4 of the lower level BE in the illustrated advantageous embodiment, so that there is a special explanation unnecessary. 6, the valves corresponding to the check valves 105 to 108 of the upper level AE are designated by the numbers 115 to 118 in the lower level BE.

The invention is not restricted to the reproduced and described details of the systems and the components used. Rather, other suitable parts can also be provided and modifications can be made in the actuation and control systems that serve the desired purpose.

In addition to the described actuation options for the normal operation of the device, a separate release device is provided for the tensioning device. This comes into operation under predefinable conditions, in particular if lines are broken on the way from the control station to the device or in the device itself , and also advantageous when manually triggering a switch or other suitable actuator. In the explanation of FIG. 5, such a switch ABS provided at the control station ST has already been mentioned. Certain details of the hydraulic system have also already been mentioned in connection with FIG. 6. The operation of the separate loose device is explained below using an example.

During the operational use of the device, the coil 72a of the solenoid valve 72 is energized as a result of the current being supplied via the electrical line 78, so that the solenoid valve 72 is in a different position from that shown in FIG. 6 in the other of the two possible positions in which the lines 81 and 91 are connected to the tank. It is now assumed that the aforementioned electrical line 78 is interrupted, for example by damage to the cable containing this line, for example the cable 6 running along the linkage 4 (FIG. 2). Thus, the solenoid 72a of the valve 72 is de-energized so that it or the like under the action of a loading spring. is automatically transferred to the * position shown in the drawing. 6, pressure medium from the previously filled accumulator 75, via line 74, valve 72, lines 81 and 91 and via check valves 82, 92 into collecting lines 83, 93 and thus to the small cylinder spaces A12 and B12 of the units AI to A4 of the upper level AE and the units B1 to B4 of the lower level BE flow. As a result, the clamping pieces 10 of all units are retracted in the two levels, so that the entire device is detached from the borehole wall. From the large cylinder spaces All and B1 of the units AI to A4 and B1 to B4, the displaced hydraulic fluid can be released via the unlockable check valves 41a to 44a shown for the upper level in FIG. 6 and the solenoid valves of the valve block VA and via corresponding elements of the lower level Tank 30 out flow out. The solenoid valves of the valve block VA are each spring-loaded, so that they automatically return to the drawn position both in the event of an intended shutdown and in the event of a power failure. An electrical shutdown can also be effected automatically as a function of another process, in particular as a function of the coil of the solenoid valve 72 becoming de-energized. In the process described, the check valves 41a to 44a for the backflow of the hydraulic fluid from the large cylinder spaces of all of the units AI to A4 in turn is unlocked by supplying pressure medium to line 88, and now pressure medium from memory 75, which reaches switch line 88 via line 113 branching off line 81 and shuttle valve 77. This process takes place in both bracing levels AE and BE at the same time, regardless of how the hydraulic units are operated or controlled in each level, either individually or in one level together.

The pressure switch 76 mentioned above (FIG. 6) can first of all serve to cause a signal on a display device 114 at the control station ST (FIG. 5) for days to indicate that the memory 75 is in the desired position Way is filled with the predetermined pressure. Advantageously, the pressure switch is still used to block or prevent certain switching processes or operating functions until the predetermined storage pressure is reached. In particular, the design is such that the clamping piece 10 can only be extended in the two levels AE and BE when the memory 75 is properly filled. This can be achieved by a simple electrical circuit for which the person skilled in the art has the means at his disposal. This ensures that work on the device in the drilling insert is only just beginning can be when the safety release device has reached its operational state.

The sequence of a drilling process with several steps for correcting the direction is explained below. For the sake of simplicity, only a deviation in the Y plane is considered. If there is a deviation in the X plane, the situation is analogous.

A first state is assumed in which, after drilling a stroke, a deviation from the target axis by a certain amount Y and thus by a certain angle has occurred. This is indicated on the control station ST on the devices NX and NY with corresponding values. The tension is released, i.e. the clamping pieces 10 are retracted. The device is raised somewhat by means of the rod 4 so that the drill head 1 is at a short distance from the bottom of the borehole. If there is a relatively large deviation from the desired direction, the device cannot hang completely freely in the borehole, rather the drill head lies on one side against the borehole wall.

To carry out a correction, the clamping pieces 10 are then first extended by different amounts with the aid of the control in accordance with the respective measured value display so that the device assumes the desired position, whereupon the clamping is then effected in this position.

The circumstances allow the device to be adjusted and braced not only perpendicularly, but in the opposite direction to the deviation, with the aid of the control, in accordance with the respective measured value display. After drilling one or more further sections, it is then determined, for example, that the drill head is on the desired axis. Thus, the device is now set again vertically and clamped, so that its axis coincides with the target axis. Then you can drill in the vertical direction.

In a further measurement, e.g. result that the device hangs freely in the borehole when the drill head is lifted off the bottom of the borehole, without the drill head resting against the borehole wall on any side, and that the longitudinal axis of the device coincides with the desired axis.

Then, all the clamping pieces are extended to the same path until it contacts the borehole wall, and there is _effected, Verspaπnung. The next drilling stroke can then be carried out vertically on the target axis.

Corresponding correction options with a similar procedure exist for deviations in a different direction or to other sides.

As already described above in the explanation of FIGS. 1 to 4, the device is equipped with lifting drives 27, by means of which the guide part 22 and the working part 21 can be displaced relative to one another in the direction of the longitudinal axis L of the device. FIG. 7 shows a schematic representation of the device of such lifting drives together with further advantageous features.

In the embodiment shown, the lifting drives 27 are designed as hydraulic cylinders and piston units arranged parallel to one another. But it is also possible depending on the circumstances and requirements, to select other types of drives for performing linear movements, such as electric motors with rack and pinion gear or the like. As can be seen in FIG. 7, here cylinders 121 with pivot pins 122 are held on bearing blocks 123 which are fastened to the working part 21. The ends of the piston rod 124 are connected to brackets 126 on the guide part 22 via pivot pins 125. The lifting drives 27 can only serve as catch-up devices in order to support the lowering of the guide parts 22 into the starting position for a new drilling stroke after the completion of a drilling stroke. However, they can also be designed as feed devices in order to increase the pressure force of the drill head during drilling. Depending on the requirements, the linear actuators can be single-acting or double-acting

The pressure medium supply for the cylinder-piston units is not particularly shown in the drawing. It can be carried out from the hydraulic unit housed in the working part 21 of the device, with the control station ST for days using the switch 66 or the like. (Fig. 5) to be actuated solenoid valves are available, via which the cylinders 121 of the units 27 can be supplied with pressure medium in the desired manner. Components similar to the units of the bracing devices can therefore be provided.

The device is equipped with a displacement measuring system for detecting the relative movement between working part 21 and guide part 22. In principle, this can be arranged at any point where such a distance measurement is possible. In a simple and expedient embodiment, a displacement measuring system is provided on at least one lifting drive. 7 shows a displacement measuring head 127 on the cylinder-piston unit 27 on the left in this figure. Displacement measuring devices for hydraulic cylinders are known to the person skilled in the art available per se, so that details of the same need not be discussed in more detail here. Such devices can work in particular without contact or with indirect scanning, for example inductively.

From the measuring head 127, a signal line 128 leads to a central command unit 129, from which a line, not shown, goes to the display instrument 67 at the control station ST (FIG. 5), so that here the size of the relative movement between the working part 21 and the guide part is always present 22 or the respective position of the working part can be determined relative to the guide part.

A safety system is linked to the lifting drives 27 and the clamping device for the clamping pieces 10. This serves among other things to prevent damage to the device in the event of incorrect actuation or improper operating conditions. The path which the working part and the guide part can execute relative to one another and which at least essentially corresponds to the drilling stroke is determined by the maximum working stroke of the cylinder-piston units 27. Would this path be exceeded, e.g. by the fact that the working part 21 with the guide part 22 clamped by means of the linkage 4 when the units 27 are extended, pushed down beyond their stroke end or pulled upwards when the units are retracted, this would result in damage or destruction to the parts of the device, to the drill head or to Linkage.

The basic idea of the safety system is that the tensioning of the guide part 22 is automatically released when there is a risk of the permissible relative path between the working part 21 and the guide part 22 being exceeded. For this purpose, at least one reporting point is pre-selected in the lifting drive 27 Distance before a stroke end, in particular at the extension stroke, is provided, when it is reached a warning signal is given on a display device at the control station, so that the operator is made aware that he should switch off the drill head drive and / or the chip removal must solve the guide part. If there is no reaction to the warning signal, the drill head drive 18 is automatically switched off and the tensioning device is automatically released after a predetermined distance. The drill head drive is switched off when the appropriate signal is given by suitable components available to the person skilled in the art in the control system for the drive, for example in the case of electric drill head motors with the aid of electrical switching elements and in the case of hydraulic drill head motors via valves or switching off a pump motor . Depending on the design of the clamping device and the type of linear motors for the clamping pieces 10, the tensioning of the guide part is released by control elements suitable for them. In the hydraulic tensioning device explained above, the command issued by the safety system can be used to actuate the solenoid valves intended for normal operation, or the command of the safety system can be used to separate the separate release device with transfer of the solenoid valve 72 to the one shown in FIG. 6 position shown are triggered.

In FIG. 7, the number 130 denotes a unit which contains, among other things, the distributor blocks VA and VB with the various valves and other components, the signal connection between the command unit 129 and the unit 130 and through a line 131 several lines are indicated the connections to the linear drives 14 of the two bracing levels AE and BE. According to a very advantageous embodiment of the device, when the loose device for the tensioning device takes effect, the drill head drive is also switched off for the sake of safety. In FIG. 7, the number 132 indicates a switching line leading from the command unit 129 to the drive unit 18. The safety system only needs to issue a command to release the tension and switch off the drill head drive at the same time. A manual shutdown with retraction of the clamping pieces 10 can be effected by the already mentioned switch ABS at the control station ST (FIG. 5).

The training can also be made such that a further reporting point is provided between a first reporting point for emitting a warning signal and the end of the stroke, when it is reached the tension is immediately released and the drill head drive is switched off.

All of the above does not only apply to the approach to the end of the stroke when the linear actuators are extended, rather, corresponding precautions can be taken with one or more reporting points even when the end of the stroke is approached when the linear actuators are retracted. The explanations given apply accordingly and accordingly.

All the features mentioned in the above description or shown in the drawing, if the known prior art permits, should be regarded as falling within the scope of the invention, either alone or in combinations.

Claims

P a t e n t a n s r u c h e

Device for drilling substantially vertical bores, in particular large-bore holes, shafts or the like, with a unit that can be suspended in the borehole and suspended on a supporting strand, which includes a drilling tool that can be driven in rotation, a guide part that can be fixed on the borehole wall for carrying out the drilling process, with a tensioning device device, which has two clamping planes at a distance from one another in the longitudinal direction of the device, each having a plurality of clamping pieces which can be moved radially inwards and outwards by linear drives and can be pressed against the wall of the borehole, a working part which can be moved together with the drilling tool relative to the guide part in the drilling direction, and a measuring device - Includes adjusting means and adjusting means for adjusting the guide part in a predeterminable direction, with signal transmission means or the like with display and actuating elements on a control stand. can be connected above ground, and with a device for removing the drilling material upwards, characterized by the following features: - The bracing device (10, 14) at least partially forms the adjusting device,

- each linear drive (14) can be controlled independently in at least one bracing plane (AE or BE,

- The linear drives (14) are at least partially displacement measuring devices (47) with display elements

(Gl to G4) assigned to the steering position (ST),

- For the tensioning device (10, 14), in addition to an actuation system (AS1 to AS4, VA; BS1 to BS4, VB), a separate loose device (72, 74, 75, 82 or 92, 83 or 93) provided.

2. Device according to claim 1, characterized in that all linear drives (14) in the two Verspann¬ planes (AE, BE) are individually controllable and equipped with Wegmeßein¬ devices (47).

3. Device according to one of claims 1 and 2, characterized in that the supporting strand is a non-rotating "linkage (4) and in the working part (21) a rotary drive (18) for the drilling tool (1) is provided.

4. Device according to one of claims 1 and 2, characterized in that a linkage is provided as the supporting strand, via which the drilling tool (1) can be driven in rotation.

5. Device according to one of claims 1 and 2, characterized in that a rope or the like as a supporting strand. is provided.

6. Device according to one of claims 1 to 5, characterized in that it is designed to carry out a Bohr¬ method with indirect rinsing.

7. The device according to claim 6, characterized in that the supporting strand (4) is designed as a conveying path for the drill material.

8. Device according to one of claims 1 to 7, characterized in that at least a part of the Linear¬ drives (14) force or pressure measuring devices (59, 60) are assigned ..

9. Device according to one of claims 1 to 8, characterized in that the separate release device for the tensioning device has an energy store (75) and at least one switching or control element (72, ABS) for effecting the release process.

10. Device according to one of claims 1 to 9, characterized in that the separate Lδseeinrichtung (72, 75) is designed for automatically causing the release process when predetermined conditions occur.

11. The device according to claim 10, characterized in that a condition for the automatic effect of the release process is a failure of signal and / or energy transmission elements (6, 7, 8, 9, 78).

12. Device according to one of claims 9 to 11, marked by an arrangement (76) which allows actuation of the tensioning device for the guide part (22) in the sense of tensioning only when the energy store (75) is full.

13. The device according to one of claims 1 to 12 with a cylinder-piston units as linear actuators comprise the hydraulic bracing device, characterized in that the separate release device has a Contains hydraulic accumulator (75) and a valve device (72), by means of which all cylinder-piston units (AI to A4; Bl to B4) can be actuated in the sense of a radial inward movement of the clamping pieces (10) for the release process.

14. The apparatus according to claim 13, characterized in that the valve device has a directional valve (72) which can be automatically returned into a position suitable for effecting the release process.

15. Device according to one of claims 1 to 14, gekenn¬ characterized by a displacement measuring device (127, 129) for the relative movement between the working part (21) and guide part (22).

16. The device according to one of claims 1 to 15, characterized by a security system, by means of which when predetermined relative positions of the working part (21) and guide part (22) are exceeded, control or actuation processes can be triggered.

17. Device according to one of claims 1 to 16, marked by lifting drives (27), by means of which the guide part (22) and the working part (21) can be displaced relative to one another in the direction of the longitudinal axis (L) of the device.

18. The apparatus according to claim 17, characterized in that the displacement measuring device according to one of claims 15 and 16 are associated with the lifting drives (27).

19. Device according to one of claims 17 and 18, characterized in that the lifting drives (27) are designed exclusively for making up the guide part (22).

20. Device according to one of claims 17 and 18, characterized in that the lifting drives (27) are designed as feed devices.

21. Device according to one of claims 1 to 20, characterized in that the clamping pieces (10) in one bracing plane (AE) relative to the clamping pieces (10) of the other bracing plane (BE) are offset in the circumferential direction by an angle to each other.