EP1213441B1 - Drilling system - Google Patents

Description

The invention relates to a drilling system with a drill head on a Drill pipe is attached, which consists of an outer tube and one in it inserted blow rod consists of, the blow rod consists of several with their end faces against each other.

Such a drilling system is known from EP 0 387 218 B1. It is a rock drilling device to create straight Drill holes for receiving anchors for buildings or explosive charges to carry out rock blasting. The cylindrical shaft of the Drill bit at the front end of the outer tube over a few centimeters long, cylindrical guide with little play axially displaceable held. The same applies to the free end of the rear boring bar on which a percussion piston strikes to apply the impact forces. Each Rod is guided in the area of two bushings at two positions along its length. Axial channels are provided in the area of the guides of the impact rod Passage of a flushing medium is provided, which make it possible to rear end of the drill pipe from through the space between Outer tube and blow rod or through the axially extending channels a flushing medium to the drill head between the outer tube and the blow rod transport. The opposing end faces of the individual rods of the Blow rods extend in the radial direction, so that a maximum effective surface for transmitting the axially acting impact forces is created.

The device described in EP 0 387 218 B1 has some remarkable ones Advantages that essentially result from the fact that the inner percussion linkage consists of various individual rods, which without screwing against each other. The single, short rod has a lot higher natural frequency than a long screwed beater bar. So results the impact force transmission over several short, unscrewed opposing bars a much harder and undamped Clout transmission. Added to this is easier handling during of drilling. After advancing the drilling device by the length of one The outer tube section or an inner rod is the rotary and impact drive separated from the drill pipe and it becomes a new inner rod as well as a new outer tube inserted into the drill pipe. Here result time savings due to the fact that the inner to be inserted Rod does not have to be screwed.

However, the device known from the cited document is due to their structure, they are only used in axial production Direction of the drill pipe running holes suitable.

The document US 2,684,581 discloses a flexible drill pipe with individual articulated links that are screwed together. A Power transmission via this linkage is not provided here not possible due to the screw connection of the individual links.

The object of the present invention is a drilling system with percussion rods to create, which allows a greater variation of the drilling direction.

This object is achieved in that the outer tube is formed deformable along its longitudinal axis and against each other adjacent end faces of two rods are designed such that they an inclination of the axes of the two rods to each other essentially lie flat against each other.

Drilling systems with elastically bendable outer tubes - so-called directional drilling systems - are known from the prior art, for example from DE 196 12 902 A1. In this document it is stated that a drill pipe with a drill head that creates a curved hole pattern for directional drilling is used. When drilling straight ahead, the Drilling head with a constant, usually low angular velocity rotated so that the force deflecting the drill head is evenly on the distributed over the entire circumference of the drill head and thus cancels. For drilling of a radius, the drill head remains in a certain angular position without Drill drive so that it is given due to its design features Curve follows. The drill heads can be very different be trained. The drill pipe is usually on a rail-guided, mounted and has a slide connected to a linear drive a rotary or rotary impact drive with which the linkage rotates move and if necessary can also drive into the ground. With the previously known Directional drilling systems basically became the outer linkage for transmission the punch used. This resulted in addition to that previously described Problem that the long outer linkage has a low natural frequency and has a high mass, an additional one Problem that the wall friction of the outer linkage, which in the curved borehole in the ground is a significant Share of impact energy is reduced. In addition to the mass of the Outer tube the mass of the flushing medium contained in the outer tube be accelerated by the percussion drive. Finally, a blow creates not only axial acceleration on the rear end of a bent tube, but also a bending force. In practice it has been shown that the impact on the rear end of the drill pipe hardly in Area of the drill head arrives.

The inner linkage, which for example from FIGS. 6 and 7 of the DE 196 12 902 A1 is recognizable, could not be used to transmit the impact force be used. Either the individual elements were suggested to connect the inner linkage to one another via universal joints, which be destroyed by sustained strikes. Alternatively, it has been suggested with a sufficiently flexible inner linkage on the cardan joints to renounce. With great flexibility, however, it is not sufficient large power transmission is possible.

The proposal according to the invention, a drilling system with unscrewed against each other as a directional drilling system with a Providing a flexible outer tube enables the transmission of impact force over the inner percussion linkage when the are against each other End faces of two rods are designed such that they also at one Tilting the axes of the two rods to each other essentially lie flat against each other. In other words, had to - starting from the drilling system described in the introduction from EP 387 218 B1 - from end surfaces deviating from the flat, radial shape are proposed, thus an effective transmission of impact force even in the case of bending of the outer tube, which is an inclination of the longitudinal axes of two Stop boring bars to each other, is guaranteed.

Compared to the known impact transmission in directional drilling systems Via the outer tube, the impact force is transmitted via an inner one Percussion linkage has the decisive advantage that the impact force is not reduced Friction of the blow rod on the wall of the bore can be reduced can. As a rule, there is a between the outer tube and inner rod Flushing medium passed, which for example from water with swellable clay (bentonite). The watery, swellable clay has one viscous to pasty consistency and produces relatively low frictional resistance when moving the blow rod against the outer tube. The flushing medium itself is not accelerated by the blows and cannot absorb impact energy.

The blows are from short, straight rod sections of the inner rod transferred, whereby no bending forces can arise because the individual rods of the inner rod are not curved.

An essential feature of the invention is that in the inner blow linkage the directional drilling system according to the invention no fixed connection exists between the ends of the individual rods of the blow rod. In particular, there was no screwing of the rod ends. Especially with directional drilling, in which - unlike straight drilling processes - often only a slow rotary drive of the drill head takes place or the Drill head fully in a certain angular position for a longer one A bolted handlebar is unsuitable. acts a permanent, hydraulic impact drive on a screwed rod, the screw connections are usually loosened by the blows. Only if the linkage is constant due to a rotary drive in the closing direction the screw is driven, it is ensured that despite the Impacts on the linkage will not open the screw connections. at a directional drilling device in which the rotary drive is often for one must be stopped for a long period of time, there is a risk that due to of the strikes the screw connections of the individual rods of the striking drive be resolved, causing destruction of the percussion linkage at one further advance of the drilling system.

This danger does not exist with the drilling system according to the invention, which on fixed connections of the rod ends, especially screw connections the rod ends, waived.

Since the outer tube is designed to be deformable along its longitudinal axis, that is to say that the longitudinal axis can be bent in a radius around a center of a circle, care should be taken that each rod is supported against the inner wall of the outer tube only in one or in two short regions of its length. The solution is particularly preferred in which each rod is supported against the outer tube only in a single annular region of its circumference and has an outer diameter in the other regions of its length that is one or more centimeters smaller than the inner diameter of the outer tube. In the area of a bend in the outer tube, the inner percussion linkage can run from support point to support point in different straight sections.

Care should still be taken to ensure that the unhindered passage of flushing medium through the annular space between the outer tube and the blow rod is possible. This should be done in the area where each rod of the Percussion linkage is guided on the inner wall of the outer tube, one in recess extending in the axial direction or in the axial direction extending channel may be provided so that the passage continues of the flushing medium is possible. For example, in the broad, against areas of the rod in contact with the inner wall of the outer tube Longitudinal grooves are provided, through which the Flushing medium flows. Alternatively, the outer tube can be used over its entire length be provided with axial grooves for the flushing liquid to pass through. However, this leads to an increase in the manufacturing costs for the Outer tube to be expected.

In a particularly preferred embodiment of the invention, the mutually abutting end faces of two rods of the blow rod on the one hand convex and on the other hand concave. Preferably each has Baton rod a first end with a ball head and one second end with a spherical shell, the radii of curvature of the Spherical surfaces of the spherical head and the spherical shell essentially each other correspond. The blow rod of the blow drive, on which the blow piston of the percussion drive should then be one to the end face of the rearmost rod of the blow rod have a complementary surface. The shaft of the drill bit also has an end face with the drill head on that to the foremost end face of the foremost rod of the blow rod is complementary.

With a spherical head-shaped end of the impact rod, the spherical head preferably forms the area for the radial support of the rod against the Inner wall of the outer tube. The cylindrical rod-shaped starting from the ball head Section of the rod has a smaller diameter than the ball head on. To form the axially extending passage channels for The flushing medium has the ball head in the area of its equator axially extending recesses arranged on the longitudinal axis of the rod on.

As mentioned at the beginning, a torque is transmitted to the drill head, to either rotate it continuously or to a certain angular position to bring if a radius is to be drilled. For directional drilling systems according to the state of the art, where possible generated impact forces are transmitted via the outer tube is the Drill head simply rigidly connected to the outer tube. In the present case, in the impact forces are transferred to a drill bit, this can Drill bits are held in the outer tube in a rotationally fixed manner, being a certain distance should be axially movable. Due to the axially movable Storage of the drill bit is avoided that on the drill bit impact energy is introduced into the outer tube. The drill bit is displaceable relative to the outer tube, so that the impact energy transmits directly over the drill head to the bottom of the hole.

The rotationally fixed receptacle of the drill bit in the outer tube can, for example through a positive connection between the shaft of the Drill bit and the outer tube can be achieved. The drill bit shank can be provided with an external toothing, which in a Internal toothing of the outer tube engages. The rotary drive is then with connected to the rear end of the outer tube and is preferably used for Achievement of the required torques hydraulically operated.

Alternatively, the torques can be applied to the drill head via the blow rod are transmitted when the ends of two against each other Rods interlocking interlocking elements exhibit. For example, one of the ends, in particular the end in Shape of a spherical shell, with a recess into which a Projection at the other end, especially the end in the form of the Ball head, protrudes. The spherical shell can be placed on one in the longitudinal direction of the rod-extending great circle lying groove in the area of have outer circumference of the ball. The ball head can be used on two diametrically opposite positions each have a cylindrical shape Have tenons, each of the tenons in one end of the groove in the spherical shell engages. The pins can be moved in the direction of the groove are and are pivoted about their pin axis. Such claw-shaped connection between the end of the first rod and the the end of the second rod adjoining this allows sufficient transmission high torque. In such an embodiment, too the drill bit rotatably with the foremost end face of the blow rod get connected. The rear end of the blow rod must be in this Case with the rotary drive be rotatably connected, so that rotational forces of the drive unit outside the borehole to the drill head can be. Also by transferring the torque through the inner Percussion linkage can significantly reduce the loss of friction. The Rotational forces do not have to counteract the friction within the whole Borehole, but only contrary to that between the outer tube and the Percussion rods acting friction forces are transmitted.

The claw-shaped connection of the rod ends described merely provides an example. There are any other positive connections possible, which is a pivoting of the individual rods of the blow rod allow against each other. It should be noted that a movement game sufficient by a few degrees between the two end faces of the rods can be to the required inclination between two rods too enable. Due to the limited flexibility of the outer tube usually achieved very large radii of the borehole axis, so that the individual rods are only inclined to each other by a few degrees are.

Preferably, the ends of two mutually abutting rods Guide elements, which when axially opposed and Press the rod ends into the projection for torque transmission lead the recess. This ensures that, for example, when Attach a new outer tube and a new inner rod to the Drill pipe without special adjustment by the operating personnel non-rotatable connection between the individual rods of the blow rod is achieved. Even if the rods of the inner rod are in the process of being inserted a new section of the drill pipe from each other then firmly connecting the drill pipe to the drive unit the non-rotatable connection automatically due to the guide elements restored between the individual rods.

In this embodiment, the rotary drive with the percussion linkage be connected. To avoid impact forces in the rotary drive or the gearbox of the rotary actuator, an impact rod should move axially though be rotatably held in the rotary drive. A drive pinion can be used for this have an internal toothing, which with an axially extending External toothing of the impact rod interacts and the axial freedom of movement guaranteed with positive locking in the circumferential direction.

Between the shank of the drill bit and the outer tube is preferred a seal is arranged to prevent uncontrolled leakage of the rinsing liquid to avoid. The shank of the drill bit also has one axially extending channel through which the flushing liquid or the flushing medium from the annular space between the blow rod and the outer tube to Drill head is directed.

To close the drill bit within the end section of the outer tube fix, the outer tube has a radial constriction near the drill head of the inner diameter, one on the shaft of the drill bit Diameter extension is arranged, which is larger than the constriction of the inner diameter of the outer tube. Thus, the drill bit is through radial diameter expansion to prevent it falling out of the end section of the outer tube secured. In a practical embodiment, this is Driver profile of the outer tube in the form of an internal toothing on the Screwed tight end of the outer tube. This screw connection preferably fixes a split retaining ring which can be inserted into the outer tube and which holds the Narrowing of the inner diameter of the outer tube forms. On the shaft of the drill bit is also an annular body, which whose diameter extension forms. That at the end of the front section screwed element of the outer tube with the teeth preferably also a sensor or signal transmitter by means of which the position of the drill head via a measuring device outside the Drill hole can be determined so that the drill drive to achieve the desired Control the drilling process.

All sections of the outer tube are preferably via screwed sockets connected with each other. The screw sockets can one with respect to the Diameter of the sections of the outer tube expanded diameter Have recording of the ball head.

The percussion drive for the percussion linkage strikes in the feed direction rearmost rod of the blow rod. He is usually behind that Flanged to the rotary drive, with it projecting through a rotary drive Impact rod acts, which is axially displaceable relative to the rotary drive, so that the impact forces applied to them do not enter the rotary drive, but be introduced into the blow rod.

The rinse liquid supply is preferably near the front end the impact rod on a screw connection between the rotary drive and the rearmost section of the outer tube and is arranged by a radial channel formed between the outer tube in the annular space Outer tube and blow rod works. Between the outer tube and the The front section of the impact bar is preferably a seal package arranged, which is the annular space between the outer tube and impact rod seals. This ensures that the flushing medium only through the annular space between the outer tube and the blow rod to the front is conveyed to the drill head and not backwards in the direction of the drive for the drill pipe.

In a further preferred embodiment, the blow rod can can optionally be locked in the axial direction with respect to the outer tube. The lock acts at least in the feed direction, in which the Effective. The lock causes the striking forces transferred from the piston to the outer tube via the blow rod become. As long as the impact forces are to be used, the Driving the drill bit as quickly as possible is the outer tube of that To decouple the blow rods so that the impact forces only on the Drill bits act and are transferred from this into the bottom of the borehole become. If it is desired, the outer tube with the striking mechanism To strike, e.g. about high frictional forces in the borehole To overcome, the outer tube can be coupled with the blow rod become. The impact forces can also temporarily in the outer tube, which consists of several screwed pipe sections, to be introduced loosen the screw connections between the pipe sections. The coupling, that is, the connection fixed in the axial direction must at least in the Direction in which the impact forces act.

The coupling between the outer tube and the blow rod is preferably carried out in the area of the drill bit at the front end of the drill pipe. Consequently the percussion linkage is loaded by the percussion mechanism and its Compressive forces at the front end in the area of the drill bit on the outer tube transfer. This is due to the impact forces in the feed direction or direction of impact. The diameter widening is preferred the drill bit, which fixes it in the outer tube, used to effect the axial coupling. This can be done by expanding the diameter in the axial direction against the diameter narrowing of the Outer tube can be designed to be lockable.

This can be achieved in that the outer tube on the tunneling machine Slidable in the axial direction and in at least two different is fixed axially fixed positions. For example, a part of the outer tube have radial pins which are in a sliding sleeve are guided, which is attached to the tunneling machine. The sliding sleeve has a guide groove with an axial one for each radial pin Section and two circumferential holding sections the two ends of the axial section. The radial spigot of the Outer tube can be in the guide groove in either the first or in the second holding section can be included. In the first holding section the front end of the front tube end section of the outer tube against the rear contact surface of the drill bit, so that the drill bit forward, that is in the direction of impact and feed, freely in the Outer tube is held. In the second holding section, however, is the Diameter narrowing of the outer tube against the diameter expansion of the drill bit so that the axial impact forces are exerted on the drill bit be transferred to the outer tube.

Fig. 1

eine schematische Darstellung einer Vorrichtung zur Durchführung des Richtungsbohrens,

Fig. 2

einen erfindungsgemäßen Bohrstrang eines Richtungsbohrsystems,

Fig. 3

eine alternative Ausführungsform des Bohrkopfes des Richtungsbohrsystems aus Fig. 2,

Fig. 4

eine vergrößerte Ansicht der Antriebsvorrichtung des erfindungsgemäßen Bohrsystems,

Fig. 5

eine Ansicht eines Verbindungsbereiches, in dem zwei Abschnitte des Bohrgestänges aneinandergefügt sind,

Fig. 6

den Endabschnitt des Bohrgestänges mit der ersten Ausführungsform des Bohrkopfes aus Fig. 2,

Fig. 7 - 10

eine alternative Ausführungsform des erfindungsgemäßen Richtungsbohrsystems mit einem zur Drehkraftübertragung ausgebildeten Schlaggestänge,

Fig. 11-12

eine den Fig. 7-10 entsprechende Ausführungsform des erfindungsgemäßen Richtungsbohrsystems mit einer Schlagkraftübertragung von dem Schlaggestänge auf das Außenrohr.

The invention is described below using exemplary embodiments with reference to the accompanying drawings. The drawings show in:

Fig. 1

1 shows a schematic representation of a device for performing directional drilling,

Fig. 2

a drill string according to the invention of a directional drilling system,

Fig. 3

2 shows an alternative embodiment of the drilling head of the directional drilling system from FIG. 2,

Fig. 4

2 shows an enlarged view of the drive device of the drilling system according to the invention,

Fig. 5

1 shows a view of a connection area in which two sections of the drill pipe are joined together,

Fig. 6

the end section of the drill pipe with the first embodiment of the drill head from FIG. 2,

7-10

an alternative embodiment of the directional drilling system according to the invention with a blow rod designed for torque transmission,

Fig. 11-12

7-10 corresponding embodiment of the directional drilling system according to the invention with an impact force transmission from the impact rod to the outer tube.

The mode of operation of directional drilling can be seen in FIG. 1. With A boring machine 1 becomes a drilling head for producing a bore 2 driven into the ground at an angle by means of a drill pipe 3. The drill pipe 3 is on a rail-guided carriage Jacking machine 1 is stored and is with a linear drive in the Soil driven. After driving through a certain distance, is on the drill pipe 3 is a new section of the drill pipe 3 consisting of an outer tube section 15 and a rod 14 inserted therein Percussion linkage 13 (see FIG. 2) added and the sled pulled back, to advance the extended drill pipe 3.

In the vicinity of the drill head 2 there is a usually magnetic probe 4 arranged, which allows a navigation system and a monitor unit to determine the exact position of the drill head 2. The tunneling machine 1 also has a rotary drive with which the drill pipe 3 rotated about its longitudinal axis and in a certain angular position can be locked. In this way, the plane of the radius of curvature of the generated bore can be inclined in any direction. The hole can thus be largely parallel to the surface of the earth in any Directions. In particular, the bore - as in FIG. 1 recognizable - with a large radius of curvature from an inlet opening be led into the ground to an outlet opening, so that without an open shoring obstacles such as buildings, water or traffic areas can be overcome. When just drilling sections to be, the drill head 2 is rotated evenly around its axis.

A pumping and mixing unit 5 for a rinsing medium, also support liquid called, which consists of a mixture of bentonite and water connected to the drill pipe 3. The support fluid is under high Pressure is passed into the drill pipe 3 and emerges from flushing nozzles in the drill head 2 out. As a result, the material removal in the area of the drill head 2 causes. The bentonite in the support fluid then settles in the Annular gap between the drill pipe and the borehole. This will on the one hand supports the borehole produced and on the other hand it is quite low-friction Generated sliding film, the resistance to the propulsion of the Drill pipe 3 reduced.

After completion of the pilot bore, the drill head 2, which is made of the Exit opening of the bore has emerged from the drill string 3 away. An extension drill head can then be attached to drill pipe 3 are attached, which in turn with the drill string 3 through Pilot hole is pulled through.

The major part of the material removal during drilling is due to the flushing medium emerging from the flushing nozzles of the drilling head 2. In hard rock in particular, the material is removed by the Impact forces exerted by the drill head and, if necessary, continuous rapid rotational movements elevated.

Fig. 2 shows an inventive drill pipe, which the transmission of impact forces and rotational movements from the propulsion device 1 on the drill head 2. This embodiment includes a directional drilling head, which is designed as a steering shoe. The front one End face 6 of the drill head 2 is to the radial direction of the to be created Hole inclined. Three outlet nozzles 7, 8, 9 for the supporting liquid are exemplary shown, which the drill head 2 through an axial channel 10th is fed. The medium emerging from the outlet nozzle 8 flows along a groove 11 in the end face of the drill head 2 and is distributed then in the borehole. Several outlet nozzles 9 are on the circumference distributed of the drill head 2 and one opens into the end face 6. Die End face 6 of the drill head 2 also has hardened drill tip 47. Because of the inclined face 6, the deflection of the Drill head 2 on a circular path, as shown in Fig. 1. Will the Drill head 2 rotated by rotating the drill string 3, so the rotates Level in which the drill head 2 is deflected.

As can be seen in FIG. 2, the drill pipe 3 consists of an outer tube 12 and a blow rod 13. The blow rod 13 is there from individual rods 14 and the outer tube 12 from individual tube sections 15. The pipe sections 15 are each via connecting sleeves 16 screwed together. The rods 14 of the blow rod 13 are without Connection in the axial direction with their end faces against each other.

On the rearmost rod 14 there is an impact rod 17, through which a hydraulically driven piston 18 (see FIG. 4) axial impacts be applied.

As can be seen in Fig. 1, a light on the entire drill string 3 Curvature applied to the directional drilling typical to follow the curved course of the borehole. The outer tube 12 or its Pipe sections 15 have sufficient flexibility to be elastic to be curved within the borehole. The individual rods 14 of the Percussion linkage 13, however, should be largely rigid to the impact energy towards the drilling head 2 without any delay and without loss transfer. For this reason, the end faces are against each other of the rod ends curved so that the axes of the rods 14 one Can have angles to each other and still a flat concern the rod ends for the transmission of impact force is guaranteed.

5 shows in particular the features of the formation of the various Rod ends. The rear end of the rod in the direction of advance 19 spherical. The front rod end 20 has one smaller diameter and has the shape of a spherical shell, whose Diameter corresponds to the diameter of the spherical rod end 19. It can easily be seen that even with an inclination the longitudinal axes of the two bars 14 shown in Fig. 5 a flat Concern of the rod ends 19.20 against each other is guaranteed. This delivers the effective transmission of impact power from the impact drive the drill head 2 safely. 5 shows the diameter of the rear spherical rod end 19 larger than the diameter in the rest Area of the rod 14. The area of the spherical rod end 19 is also larger than the inside diameter of a pipe section 15. Das spherical rod end 19 is inserted into the connecting sleeve 16, which has a larger inner diameter than that connected to it Pipe sections 15. This is the end of the bar over a certain distance held axially displaceably in the connecting sleeve 16 without out of it to fall out. It can also be seen in FIG. 5 that the surface of the spherical rod end 19 radially outer recesses 21st has, which extend in the axial direction and the passage of the Allow flushing medium. The inside diameter of a pipe section 15 is slightly larger than the outer diameter of a rod 14, so that an inclination the rod 14 by a few degrees within the pipe section 15 is possible.

As shown in Fig. 1, the curvature of the borehole is very large Radius on, so that the boring bars are only a few degrees to each other be inclined and the relatively small gap between the bumper 14 and section 15 of the outer tube 12 is sufficient to To allow the drill string 3 to bend.

Fig. 4 shows the rotary drive 22 and the percussion drive 23, which on the Linear guide of the tunneling machine 1 (Fig. 1) are attached. The rotary drive 22 consists of a hydraulic motor with a pinion on its motor shaft 25 is attached, which meshes with a gear 26 which rotatably via a Connection sleeve 27 is connected to the outer tube 12. The connection sleeve 27 is encompassed by a sealed sleeve 28 into which one Supply line 29 for a flushing medium opens out. The connecting sleeve 27 has two radial feed channels 30 through which the flushing medium the inside of the outer tube 12 can enter.

The gear 26 is hollow along its axis and is one Thrust rod 17 protrudes, the front end face of which is spherical is formed and against the rear end face in the feed direction rearmost rod 14 of the blow rod 13 rests. The beater bar 17 is sealed against the connecting sleeve 27 by a plurality of seals 33, to prevent rinsing liquid from escaping backwards. On the rear end of the impact rod 17 acts the already mentioned hydraulic driven piston 18 of the impact drive 23. Of the piston 18 and the Impact drive 23 are only the front end section in FIG. 4 shown. Such percussion drives for loading drill pipes are well known in the professional world.

When the boring head 2 is being driven, the boring machine 1 (FIG. 1) the drill pipe 3 each forward by a certain length emotional. Then a unit of the drill string 3, consisting of a rod 14 and an outer tube section 15, previously attached the carriage of the tunneling machine 1 is withdrawn. In a new one The carriage step of the driving machine 1 is forward pushed.

The drill string 3 shown in Fig. 2 thus follows the 4 recognizable rotary / impact drive from a variety of Drill pipe sections, the foremost section in the feed direction of the drill pipe 3 with an end portion 31 of the outer tube and a drill bit 32 is connected. The end portion 31 of the outer tube 12 and the drill bit 32 can be seen in particular in FIG. 6. The FIG. 6 shows a representation enlarged with respect to the scale of FIG. 2 of the drill head 2 with the inclined end face 6, the outlet nozzles 7-9 for the flushing medium, which are fed from the axial channel 10. The Drill head 2 and a cylinder rod-shaped one in the forward direction Shank 34 form the two main components of the drill bit 32.

The drill bit 32 is rotatably in the front end portion 21 of the Outer tube 12 held. The shaft 34 of the drill bit 32 has one External toothing 35 which meshes with an internal tooth profile 36. So is the drill shaft 34 axially displaceable and fixed in the direction of rotation Pipe end portion 31 held. The tube end portion 31 is one Sleeve formed, which at the rear end in the direction of advance Carries external thread and with a connecting sleeve 37 at the front end of the foremost pipe section 15 of the outer pipe 12 is screwed tight. A retaining ring 38 is fixed via this threaded connection Diameter narrowing of the outer tube 12 near its end portion 31 forms. This retaining ring 38 interacts with an annular shoulder 39, which is applied to the rear end of the shaft 34 of the drill bit 32 is and forms a diameter extension of the shaft 34. hereby the drill bit 32 is retracted when the drill pipe 3 is pulled back secured against falling out against the direction of advance.

In the retaining ring 36, a seal 40 is also arranged, which the Interior of the outer tube 12 opposite the shaft 34 of the drill bit 32 seals. Are at the rear end of the shaft 34 of the drill bit 32 two inclined channel sections 41 are arranged, which in the Annular gap between the shaft 34 and the outer tube 12 open and that Entry of flushing medium into the axial channel 10 of the drill bit 32 enable.

7 and the enlarged detail representations 8a - 8c, 9a - 9c and 10 show an alternative embodiment of the drilling system in which over the percussion linkage 13 'also transmit rotational forces to the drill head 2 become.

The enlarged individual parts representations 8a-8c show the two ends 19 ' and 20 'of bars 14'. 8a shows the spherical shell-shaped in longitudinal section Rod end 20 ', in which the ball-shaped rod end 19 'is inserted. Fig. 8b shows only the ball-shaped rod end 19 'in plan view and two side views. 8c shows the spherical shell shape Rod end 20 'in plan view, in longitudinal section and in Side view. Each rod 14 'of the blow rod 13' comprises a rear, spherical head-curved rod end 19 ', on which projections 42 in Form a star are arranged. The front, spherical shell-shaped curved rod end 20 'has star-shaped grooves 43 for receiving the Projections 42 of the rear bar end 19 'of the adjacent bar 14' on. By engaging in the grooves 43 projections 42 are opposite rod ends 19 ', 20' in the direction of rotation together connected. The front rod end 20 'is preferably with guide surfaces which the protrusions 42 at the rear bar end 19 'in the grooves 43 at the front rod end 20' of the adjacent Insert rod 14 'when the ends are pressed together. In this way, the rod ends 19 ', 20' need not be in during assembly Direction of rotation to be aligned with each other.

It is not disturbing if the projections 42 and grooves 43 are free Swiveling of the ball joint, which through the rod ends 19 ', 20' is formed. As mentioned earlier, the angle is the Slanting of two adjacent rods to each other very little. A certain amount of play between the projections 42 and the grooves 43 is thus sufficient to ensure sufficient swiveling of adjacent bars 14 'to allow around the parallel position.

In an alternative, enlarged partial representation shown in FIGS. 9a-9c shows the rod ends 19 'and 20' for torque transmission FIG. 9a the rod ends 19 'and 20' which are inserted into one another, FIG the ball-shaped rod end 19 'in side view and Fig. 9c that spherical shell-shaped rod end 20 'in longitudinal section. Here are the Projections 42 'as radially extending, diametrically opposite one another Cones formed. The grooves 43 'in the spherical shell Rod ends 20 'are also diametrically opposite one another and take the pins 42 '. The embodiment of the non-rotatable shown here Connection leaves a larger swivel angle of the ball head 19 ' compared to the spherical shell 20 '.

Due to the transmission of the rotary movement by means of the blow rod 13 ', the driving force of the rotary drive 22 is no longer due to friction of the outer tube 12 reduced on the wall of the borehole.

Change because of the torque transmission by means of the blow rod 13 ' other structural details of the drilling system. So is the drill bit 34 ', which has the drill head 2, freely rotatable in the held front end of the outer tube 12 '. To initiate the torque in the hammer rod 13 'is the hollow gear 26' rotatable in the housing 44 of the rotary drive 22 mounted and not with the outer tube 12 'in Direction of rotation connected. The hollow gear 26 'has an inner tooth profile 45, which has an external toothing 46 on the impact rod 17 ' interacts. Via the inner tooth profile 45 and the external toothing 46 the torque of the rotary drive 22 is thus on the impact rod 17 ' transmitted, the impact rod 17 'with respect to the gear 26' axially is displaceable, so that the piston 18 of the impact drive 23 the rear end of the impact bar 17 'transmitted impact forces the gear 26 ', but only transferred to the percussion linkage 13' become. All spherical and spherical shell-shaped The end faces face the projections 42, 42 'and grooves 43, 43' in the direction of rotation fixed connection, so that the rotary drive 22 rotatably is connected to the drill head 2.

If the inner impact rod 13 'rotatably with the gear 26' of the Rotary drive is connected, of course, the non-rotatable coupling of the outer linkage 12 'on this gear 26' are eliminated. The detailed display 10 shows that the outer tube 12 'opposite the gear 26' a roller bearing 48 is decoupled in the direction of rotation. It can be form-fitting Connection body 49 detachable in the area of the connection between Outer tube 12 'and gear 26' are arranged. When inserting this Connecting body 49, the rotary drive acts both on the percussion linkage 13 'as well as on the outer tube 12'. Become the positive connection body 49 'away, so only the inner punch rod 13' turned.

Figure 11 with the detailed representations 11a and 11b and Figure 12 with the detailed representations 12a and 12b show an embodiment in which the impact energy on the one hand on the drill bit 32 'and on the other hand can be transferred to drill bit 32 'and outer tube 12'. For this is the outer tube 12 'via a sliding sleeve 50 with the tunneling machine connected. The sliding sleeve 50 is in the feed direction in front of the connecting sleeve 27 arranged and cooperates with a coupling section 51, on a shortened rear tube section 52 of the outer tube 12 ' is screwed on.

The coupling section 51 has three circumferential positions in uniform Distances each on a pin 53 which in a guide groove in the Sliding sleeve 50 is added. Each of the three guide grooves includes an axial portion 54 which is circumferential in two Holding sections 55, 56 merges. The pin-groove connection between the Coupling section 51 and the sliding sleeve 50 acts like a bayonet lock. In the first rotational positions shown on the left in FIGS. 11b and 12b of the coupling portion 51, the pin 53 in the axial Section 54 of the guide groove are moved. In the second, in the 11b and 12b the rotational positions of the coupling section shown on the right 51 are the pins 53 in the circumferential direction Holding portions 55,56 of the guide grooves added. The two Rotational positions are in Figures 11a and 12a on the one hand above the Center line (pin 53 received in the holding section 55 or 56) and to others below the center line (pins in the axial section 54 of the Slidable guide groove) shown.

Are the pins 53 in the front holding portion 56, as in Fig. 11 and 11a, the outer tube 12 'is relative to the percussion linkage 13 'and the drill bit 32' pushed into the front position. The drill bit 32 'is largely inserted into the outer tube 12' and can axially driven out of the outer tube 12 'by the percussion linkage 13' become. It can be seen that the annular shoulder 39, which the diameter expansion of the drill bit 32 'forms up to the retaining ring 38 in the Connection sleeve 37 in the feed or lay direction a sufficient Has movement play.

However, the pins 53 are in the rear holding section 55, such as 12 and 12a, the outer tube 12 'is relative to the percussion linkage 13 'and the drill bit 32' pushed into the rear position. The Drill bit 32 'is largely pushed out of the outer tube 12'. The annular shoulder 39, which is the diameter extension of the drill bit 32 'forms, lies axially against the retaining ring 38 in the connecting sleeve 37 so that the blows from the striking linkage 13 'on the drill bit 32 'are transferred from the drill bit 32' into the Outer tube 12 'are passed. This way when drilling impact forces into the outer tube 12 'starting from the bottom of the borehole which are e.g. the linkage with great friction on his Pull the outside further into the drill hole. Before dismantling the The arrangement can transmit the blows transmitted into the outer tube 12 ' the connecting thread between the individual pipe sections 15 of the outer tube 12 'loosen.

LIST OF REFERENCE NUMBERS

1

boring machine

2,2 '

wellhead

3

drill pipe

4

magnetic probe

5

Pumping and mixing device / conveying device

6

face

7

exhaust nozzle

8th

exhaust nozzle

9

exhaust nozzle

10

channel

11

groove

12, 12 '

outer tube

13, 13 '

shock linkage

14, 14 '

pole

15

pipe section

16

coupling sleeve

17, 17 '

impact bar

18

piston

19, 19 '

rear bar end, rear end face, ball head

20, 20 '

front rod end, front end surface, spherical shell

21

recess

22

rotary drive

23

percussion drive

25

pinion

26, 26 '

gear

27

connecting sleeve

28

cuff

29

supply line

30

supply channel

31

Tube end portion

32, 32 '

drill bit

33

poetry

34, 34 '

shaft

35

external teeth

36

Internal tooth profile

37

coupling sleeve

38

Retaining ring, narrowing of diameter

39

ring-shaped heel, diameter extension

40

poetry

41

sloping channel sections

42.42 '

head Start

43.43 '

groove

44

casing

45

tooth profile

46

external teeth

47

drill

48

roller bearing

49

connecting element

50

sliding sleeve

51

coupling section

52

shortened pipe section

53

spigot

54

axial section of the guide groove

55

front holding portion of the guide groove

56

rear holding portion of the guide groove

Claims (26)

1. A drilling system having a drilling head (2, 2') fixed to a drill string (3) which comprises an outer pipe (12, 12') and a percussion string (13, 13') inserted therein, wherein the percussion string (13, 13') comprises a plurality of rods (14, 14') which bear against each other with their end faces (19, 20; 19', 20'), characterised in that the outer pipe (12, 12') is adapted to be deformable along its longitudinal axis and the end faces (19, 20; 19', 20') which bear against each other of two rods (14, 14') are so designed that they bear against each other substantially in surface contact upon inclined positioning of the axes of the two rods (14, 14') relative to each other.
2. A system according to claim 1 characterised in that each rod (14, 14') is supported only in one or two short regions of the length thereof in relation to the inside wall of the outer pipe (12, 12').
3. A system according to claim 2 characterised in that ducts or recesses (21) extending in the axial direction for a flushing medium to pass therethrough are provided in the region in which each rod (14, 14') is supported against the inner wall of the outer pipe (12, 12').
4. A system according to one of claims 1 to 3 characterised in that the end faces (19, 20; 19', 20') which bear against each other of two rods (14, 14') are curved on the one hand convexly and on the other hand concavely.
5. A system according to claim 4 characterised in that one end (19, 19') of each rod is formed by a ball head and the other end (20, 20') of each rod is formed by a ball socket.
6. A system according to claim 5 characterised in that the diameter of the ball head (19, 19') substantially corresponds to the inside diameter of the outer pipe (12, 12').
7. A system according to claim 5 or claim 6 characterised in that the diameter of the section of each rod (14, 14'), which adjoins the ball head (19, 19'), is smaller than the diameter of the ball head (19, 19').
8. A system according to one of claims 5 to 7 characterised in that, in its region which is disposed outwardly in the radial direction of the rod, the ball head (19, 19') has recesses (21) which extend in the axial direction of the rod (14, 14').
9. A system according to one of the preceding claims characterised in that the rod (14, 14') which is the foremost rod in the direction of advance movement of the drill string (3) bears with an end face (20, 20') against an end face of a drilling bit (32, 32') which carries the drilling head (2, 2').
10. A system according to claim 9 characterised in that the drilling bit (32) is held axially movably and non-rotatably in the outer pipe (12).
11. A system according to claim 10 characterised in that the drilling bit (32) has a shank (34) with an external spline configuration (35) which is axially slidably guided in an internal spline profile (36) of the outer pipe (12).
12. A system according to claim 10 or claim 11 characterised in that a rotary drive (22) is connected to the outer pipe (12), the rotary drive preferably being actuated hydraulically.
13. A system according to one of claims 1 to 9 characterised in that the ends (19', 20') of two rods (14') which bear against each other have connecting elements (42, 43, 42', 43') which engage into each other in positively locking relationship, for the transmission of rotary forces.
14. A system according to claim 13 characterised in that the connecting elements comprise on the one hand at least one recess (43, 43') in one (20') of the end faces (19', 20'), which bear against each other, of the rods (14') and on the other hand at least one projection (42, 42') at the end face (20') of the other rod (14').
15. A system according to claim 14 characterised in that the ends (19', 20') of two rods which bear against each other include guide elements which, when the rod ends (19', 20') are axially pressed against each other guide the projection (42, 42') into the recess (43, 43').
16. A system according to one of claims 13 to 15 characterised in that a rotary drive (22) is connected to the percussion string (13'), which rotary drive is preferably actuated hydraulically.
17. A system according to one of claims 9 to 16 characterised in that a seal (40) is arranged between the shank (34) of the drilling bit (32) and the outer pipe (12).
18. A system according to claim 17 characterised in that at least one duct (41) for conducting a flushing medium opens in the region of the shank (34), which is in front of the seal (40) within the outer pipe (12).
19. A system according to one of claims 9 to 18 characterised in that a reduction (38) in the inside diameter is arranged in the outer pipe (12) near the drilling head (2) and that an enlargement in diameter (39) is arranged at the region of the shank (34) of the drilling bit (32), which is in front of the reduction (38) within the outer pipe, which enlargement in diameter (39) is larger than the reduction (38) in the inside diameter of the outer pipe (12).
20. A system according to one of the preceding claims characterised in that the outer pipe (12) comprises pipe sections (15) which are connected together by way of screwable connecting sleeves (16).
21. A system according to one of the preceding claims characterised in that it includes a preferably hydraulically actuated percussion drive whose piston (18) acts on the rod (14, 14') of the percussion string (13, 13'), which is the rearmost rod in the direction of advance movement of the drill string.
22. A system according to one of the preceding claims characterised in that at least one feed duct (30) which passes through the outer pipe (12) for a flushing medium is arranged near the end of the drill string (3), which is the rear end in the direction of advance movement.
23. A system according to claim 22 characterised in that the annular space between the outer pipe (12) and the percussion string (13) is sealed off at the rear end of the drill string (3).
24. A system according to one of the preceding claims characterised in that the percussion string (13') can be fixed in the axial direction with respect to the outer pipe (12') at least in the direction of advance movement.
25. A system according to claim 19 and claim 24 characterised in that the enlargement (39) in the diameter of the drilling bit (32) can be arrested with respect to the outer pipe (12'), wherein it bears in the axial direction against the reduction (38) in diameter of the outer pipe (12').
26. A system according to claim 24 or claim 25 characterised in that the outer pipe (12') is displaceable on the forward drive machine (1) in the axial direction and can be fixably secured in at least two different axial positions.

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