EP3951128B1 - Device for clearing a helical gap between turns of an auger and method for producing a borehole - Google Patents

Description

The invention relates to a device for clearing a space between the spirals of an auger, with a holder for holding the device on the mast of a drill, a guide tube which encloses the auger in sections and is mounted on the mount, and a clearing element which engages in the space between the spirals and is rotatable is mounted on the holder about a drilling axis, according to the preamble of claim 1.

The invention further relates to a method for creating a hole in the ground with a drilling device, wherein an auger is screwed into the ground to form the hole and then pulled out again, according to the preamble of claim 10.

When drilling a hole in the ground, in particular with cohesive soil material, it is often necessary to remove soil material remaining on the drill spirals after pulling the auger. It is known to provide a clearing device on a drilling device for such clearing of the drill helix interspaces and cleaning of the auger from remaining soil material.

In a simple structure, the clearing device has a stationary guide tube on which a clearing plate can be pivoted into an intermediate space in the helix to clear it. Through a coordinated turning and pulling movement of the In this way, any soil material left by the clearing plate can be removed from the space between the spirals.

Such a clearing device is, for example, from the DE 34 46 902 A1 out. Furthermore, from the EP 1 081 329 B1 a clearing device with an impeller-like clearing element is known. This impeller-like clearing member meshes with the auger flights to engage in the spaces between the flights and clean them of remaining soil material.

From the EP 2 749 729 A1 a drill with a clearing device is known, in which the clearing element is rotatably mounted around the auger and is driven by a rotary motor. A rotating drive of the clearing element allows it to revolve around the auger and thus free the space between the spirals of remaining soil material with a coordinated pulling movement of the auger. However, an energy supply via hydraulic lines or electrical lines is necessary for such an arrangement, which is associated with increased effort. The routing of power lines in the area close to the borehole, where a clearing device is basically located, is exposed to the increased risk of damage during operation. In addition, the rotary movement of the clearing element by the rotary motor and the pulling movement of the auger must be precisely coordinated, since otherwise there is a risk of damage to the clearing element and the auger.

Another clearing device is from the EP 0 744 525 B1 known. This clearing device has a holder with a guide tube firmly attached to it. A broaching device is mounted on an underside of the guide tube via an axial bearing so that it can rotate freely about the drilling axis, so that the broaching device can revolve around the drilling axis.

For clearing with this device, it is provided that it is first moved to an upper end area of the mast, so that the clearing device can move down due to its own weight when the auger is pulled. As a result, the scraper engaging in the space between the coils can move helically through the space between the coils and thus scrape off the remaining soil material. With this arrangement, the intended thrust bearing is not only axial forces but also exposed to significant transverse forces, which affects the functionality and service life of the thrust bearing and the assembly as a whole.

The SU 705 099 A1 shows a generic device according to the preamble of claim 1, with a stripping plate which engages in the space between the coils and achieves a good stripping effect only if the coil pitch remains the same. In the event of deviations, such as those caused by manufacturing tolerances in the spiral pitch, the scraper plate must be dimensioned correspondingly smaller, which reduces the clearing success in cohesive soils.

The FR 2 609 307 A1 does not show any scrapers that can rotate freely in a guide tube relative to the drilling axis, which leads to a slower clearing of the intermediate space and this only on the upper side of the spiral.

The invention is based on the object of specifying a device for clearing a space between the spirals of an auger and a method for this, with which the spaces between the spirals of a drill auger can be cleared out in a simple and reliable manner.

According to the invention, the object is achieved on the one hand by a device having the features of claim 1 and on the other hand by a method having the features of claim 10 . Preferred embodiments of the invention are given in the dependent claims.

The device according to the invention is characterized in that the guide tube is mounted on the holder so that it can rotate freely about the drilling axis, that the broaching element is fixedly attached to the rotatably mounted guide tube, that the guide tube is fixed axially in the direction of the drilling axis for broaching, and that by a pulling process the auger of the clearing element with the guide tube for clearing the auger can be rotated about the drilling axis.

A basic idea of the invention consists in mounting the guide tube, through which the auger penetrates, so that it can rotate freely on the holder. Due to the size of the guide tube, reliable and stable mounting on the holder can be provided. The clearing element is fastened to the rotatably mounted guide tube, so that the clearing element can be freely rotated with the guide tube. Freely rotatable within the meaning of the invention means that no active rotary drive is provided for rotating the clearing element, but the clearing element can perform a rotary movement due to interaction with the screw geometry when pulled. The clearing element can be attached to the guide tube in a detachable and/or adjustable manner.

A further aspect of the invention is that for broaching, the guide tube is axially fixed relative to the drilling axis. This can be achieved, for example, in that the holder is fixed or clamped to a mast of a drill. Overall, the device is designed so that by pulling the auger, the clearing element, which in the space between the coils the auger engages, with the guide tube is set in rotation about the drilling axis. Due to the auger geometry and in particular the geometry of the auger helix, an axial pulling movement of the auger is converted into a rotary movement of the clearing element together with the guide tube about the drilling axis. In this case, an axial pulling movement and the rotary movement of the clearing element are automatically and passively coordinated with one another. When the auger is pulled, it can rotate to a certain extent or stand still in the circumferential direction.

With the invention, a drill auger can be reliably cleared of remaining soil material with an overall simple and durable construction without a complex control or energy supply of the clearing device.

According to the invention, the clearing element has a clearing plate with a receiving slot in which the drill helix engages.

With the receiving slot, the clearing plate encloses the drill helix on the top and bottom from the free edge. In this case, the clearing plate can be designed in such a way that it extends entirely or over a substantial part of the radial dimension of the drill helix. This ensures that the clearing plate sweeps over the drill helix reliably and scrapes off the soil material.

According to a further development of the device according to the invention, it is advantageous that the clearing plate comprises a plate base body on which at least one adjusting plate for forming the receiving slot is adjustably mounted. Two adjusting plates are preferably provided, which form an upper edge and a lower edge of the receiving slot. Due to the adjustability of the adjusting plates on the plate body, a slot width can be freely set and adapted to the respective sheet thickness of the drill helix of an auger. The adjusting plates are preferably made of a particularly wear-resistant material, since they can rest against the drill helix and scrape off the soil material.

In the event of excessive wear, the setting plates can also be easily removed and replaced. A screw connection with slotted holes is preferably provided on the positioning plate to hold the at least one positioning plate.

The edges of the receiving slot of the broaching element can come into contact with the axially moving auger during broaching operation, so that due to the pitch of the auger helix, a displacement and thus a rotary movement of the broaching element about the drilling axis is effected.

To improve the movement of the clearing element in adaptation to the movement of the auger, a further embodiment of the invention provides that at least one guide roller is rotatably mounted on the clearing element for contact with the spiral of the auger. The at least one guide roller is preferably arranged on the clearing element in such a way that it comes to rest on an underside of the drill helix. The underside of the drill helix is the side opposite the top on which the soil material lies. Since the drill helix in particular is often not completely filled with soil material, a particularly gentle positioning of the guide roller is achieved in this way. This is further improved by the fact that the guide roller is located behind the clearing plate in a clearing direction, so that the guide roller itself does not or hardly comes into contact with soil material. The guide roller serves as a kind of cam roller which, together with the drill spiral, forms a kind of cam follower mechanism in order to convert the axial pulling movement of the auger into a rotating orbital movement of the clearing element and the guide tube.

Furthermore, according to one embodiment of the invention, particularly good mounting of the guide tube is achieved in that the holder has a ring mount on which the guide tube is rotatably mounted and accommodated. The guide tube is therefore rotatably mounted on the other side over the entire circumference, so that both axial forces and transverse forces can be reliably absorbed. In principle, the guide tube is held in a detachable and exchangeable manner, so that if the auger is changed, it can be easily adapted to a changed diameter by exchanging the guide tube.

It is particularly advantageous that a plurality of bearing rollers are arranged on the ring receptacle, with which the guide tube is rotatably mounted about the drilling axis and axially fixed to the drilling axis on the holder. The bearing rollers are mounted on the holder, in particular on an inside of the ring holder, each with a roller axis which is directed radially to the drilling axis. The bearing rollers are designed in particular as bearing rollers, with an upper ring web on the outer circumference of the guide tube resting on the bearing rollers. In order to prevent the guide sleeve from being displaced axially upwards, a lower ring web can also be attached to the outer circumference of the guide roller sleeve. The upper and the lower ring web are spaced axially by an amount which corresponds approximately to the outer diameter of the transversely directed bearing rollers. Bearing rollers arranged in this way are also referred to as tiger rollers.

A further advantageous embodiment of the invention is that the ring holder is designed with two swivel arms, which are mounted so that they can swivel between a closed operating position, in which the swivel arms are swiveled together to form the ring holder and are connected to one another via a detachable connecting device, and an open position which the swivel arms are swiveled apart to the side. This allows the ring mount to be opened, so that, for example, the auger can be removed and changed from the side in a simplified manner. In addition, swinging open the ring holder when drilling the auger, for which a clearing device is not yet required, allows this to be largely removed from the work area. This makes it possible for the clearing device not to prevent the drilling drive from moving downwards along the mast, so that the drilling drive can largely be moved downwards along the mast to the ground.

When the auger is then pulled, the pivoted pivot arms on the holder can be pivoted together again in a simple manner and firmly connected to one another again with a suitable connecting device, such as a locking bolt.

It is particularly advantageous that the guide tube can be divided to open. The guide tube can preferably be opened in two half-shells, with each half-shell preferably being held on a swivel arm. If necessary can the half-shells can also be removed from the swivel arms or fixed to the swivel arms in the open state by means of a separate fastening device. Suitable connecting devices, such as tension clamps or screw connections, can also be provided on the outer circumference of the guide tube, so that the two half-shells are reliably connected to one another again when the guide tube is closed.

According to a development of the invention, it is expedient for the holder to have a carriage guide for displaceably guiding it along the mast of the drilling device and a locking device for fixing the holder to the mast. In particular, the holder can have a sliding shoe, with which the holder and the drilling device carriage are slidably mounted along a guide on a mast, in particular a leader. Displacement can take place in any suitable manner, for example by means of an actuating cylinder or a traction cable. In particular, clamps can be provided as a locking device, which can be actuated by hand or by power.

The invention also includes a drilling device with an undercarriage, an uppercarriage mounted thereon and a mast along which a drilling drive with a driven auger is slidably mounted, the device according to the invention described above being arranged for clearing. In particular, the device is arranged in the area of the mast on the drilling device. The drilling device can in particular be a pile drilling device, with the mast being arranged and mounted essentially vertically on a carrier device with an undercarriage and superstructure.

Furthermore, the invention includes a method for creating a hole in the ground with the drilling device described above, wherein an auger is screwed into the ground to form the hole and then pulled out again. When screwing in the auger, which can in particular be a so-called endless auger, which essentially extends along the entire length of the mast, soil material is removed, which can be deposited on the helical drill helix.

It is according to the invention that when the auger is pulled, a helix gap of the auger is cleared of remaining soil material by means of the device according to the invention described above. The method is carried out by the device described above, resulting in the advantages described above.

Depending on the method, the drilled hole can be filled with a hardenable mass, in particular a concrete suspension, preferably through a core pipe of the auger, in order to form a drilled or foundation pile.

Fig. 1

eine perspektivische Ansicht einer erfindungsgemäßen Vorrichtung;

Fig. 2

eine Vorderansicht der Vorrichtung von Fig. 1;

Fig. 3

eine Draufsicht auf die Vorrichtung der Figuren 1 und 2 von oben; und

Fig. 4

eine perspektivische Teilansicht auf die Vorrichtung gemäß den Figuren 1 bis 3 mit entferntem Führungsrohr.

The invention is further described below with reference to a preferred exemplary embodiment, which is illustrated schematically in the accompanying drawings. In the drawings show:

1

a perspective view of a device according to the invention;

2

a front view of the device of FIG 1 ;

3

a top view of the device figures 1 and 2 from above; and

4

a perspective partial view of the device according to Figures 1 to 3 with the guide tube removed.

Like the Figures 1 to 3 it can be seen that a device 10 according to the invention for clearing a space between the helices of an auger (not shown) has a holder 12 with a carriage-like base body 14 . On a rear side of the base body 14 16 sliding shoes are arranged to form a carriage guide, with which the holder 12 is slidably guided and fixed along a linear guide on a mast, in particular a leader, of a drill. The carriage guide 16 can correspond to the guide on a drill drive on the mast of the drill.

On its front side, the holder 12 has a ring receptacle 50 which is usually arranged horizontally during operation and is formed by two swivel arms 52 . The swivel arms 52 are each connected via a swivel joint 56 on the base body 14 and the holder 12 between a closed operating position, which is in shown in the figures, and an open position, in which the pivot arms 52 are each pivoted laterally outwards about the pivot joint 56 . In the operating position, the swivel arms 52 are releasably connected via a connecting device 54 . In the illustrated embodiment, the connecting device 54 has a vertically directed locking bolt.

In the closed operating position of the ring receptacle 50, a guide tube 20 is received in it and is mounted so as to be rotatable about a vertically directed drilling axis 5. An inner diameter of the guide tube 20 is adapted to an outer diameter of the auger, not shown, so that the auger is held in the guide tube 20 in a guiding and rotatable manner. The guide tube 20 can itself be divisible into two parts, which is indicated schematically by an axially running parting line 24 on the guide tube 20 .

When the ring receptacle 50 is opened, the guide tube 20 can also be held and removed with a hoist with a hook, with retaining eyes 26 being arranged on the upper side of the guide tube 20 for corresponding hooks of the hoist.

The guide tube 20 protrudes through the ring receptacle 50, a clearing element 30 having a clearing holder 37 being detachably and adjustably fastened to a lower end of the guide tube 20. A plate base body 34 with a receiving slot 38 is provided on the clearing holder 37 . The receiving slot 38 is designed for laterally receiving a drill helix of the auger. A clearing plate 32 with upper and lower positioning plates 36 is provided on the plate base body 34 in order to adapt to the geometry of the auger. The upper and lower adjusting plates 36 are fastened adjustably via screw connections and corresponding elongated holes in the adjusting plates 36 for adjusting the geometry and the width of the receiving slot. The broaching mount 37 can have a swivel joint, about which the broaching element 30 can be swiveled out of a broaching position in the auger into a release position.

Furthermore, the clearing element 30 has a radially directed guide roller 40 which is arranged and designed in such a way that it comes to rest on an underside or an upper side of the drill helix. The guide roller 40 can roll on the drill helix, so that with an axial pulling movement of the auger vertically upwards due to the pitch of the drill helix, a force is exerted in the circumferential direction on the clearing element 30 and thus on the firmly connected guide tube 20 .

According to the invention, the guide tube 20 is rotatably mounted about the drilling axis 5, which is usually oriented vertically. For this purpose, the guide tube 20 has two ring ridges 22 on its outside, wherein in the figures 1 and 3 in each case only the upper annular web 22 can be seen. With the upper ring web 22, the guide tube 22 rests on radially directed bearing rollers 60 on an inner side of the ring receptacle 50, with the bearing rollers 60 in 4 are shown. In the exemplary embodiment shown, two bearing rollers 60 are each arranged on one of the two swivel arms 52 with a radially directed roller axis. On the guide tube 20, the lower ring ridge is spaced axially downwards from the upper ring ridge 22 by an amount which approximately corresponds to the diameter of the bearing rollers 60, so that the guide tube 20 is rotatably but axially fixed in the ring receptacle 50.

Due to the geometry described, when the auger is pulled axially with a certain auger pitch, a force can be exerted on the clearing element 30 with the guide roller 40, so that the freely rotatably mounted guide tube 20 with the attached clearing element 30 is set in a circular motion about the drilling axis 5 . The clearing plate 32, which engages in a space between the augers and the auger, sweeps over this area and can thus scrape off any soil material that remains on the auger.

A recess 28 for ejecting the soil material is provided in a lower region of the guide tube 20 to facilitate ejection of the soil material through the clearing plate 32, which is adapted to the space between the spirals in terms of radial and axial dimensioning.

Claims (10)

1. Device for clearing a helix gap of an auger, comprising

   - a retainer (12) for holding the device (10) on a mast of a drill,

   - a guide tube (20) which surrounds the auger in portions and is mounted on the retainer (12), and

   - a clearing element (30) which engages in the helix gap and is mounted on the retainer (12) so as to be freely rotatable about a drilling axis (5),

   - wherein the guide tube (20) is mounted on the retainer (12) so as to be freely rotatable about the drilling axis (5),

   - wherein the clearing element (30) is firmly attached to the rotatably mounted guide tube (20),

   - wherein for clearing, the guide tube (20) is axially fixed in the direction of the drilling axis (5), and

   - wherein by means of a pulling procedure of the auger, the clearing element (30), together with the guide tube (20), can be caused to rotate about the drilling axis (5), for the purpose of clearing the auger,

   characterized in that
   the clearing element (30) comprises a clearing plate (32) having a receiving slit (38) in which the drill helix engages.
2. Device according to claim 1,
   characterized in that
   the clearing plate (32) comprises a plate main body (34), on which at least one adjusting plate (36) is adjustably mounted, in order to form the receiving slit (38), wherein two adjusting plates (36) are preferably provided, which form an upper edge and a lower edge of the receiving slit (38).
3. Device according to any of claims 1 to 2,
   characterized in that
   at least one guide roller (40) for resting on a drill helix of the auger is rotatably mounted on the clearing element (30).
4. Device according to any of claims 1 to 3,
   characterized in that
   the retainer (12) comprises an annular receptacle (50) on which the guide tube (20) is rotatably mounted and received.
5. Device according to claim 4,
   characterized in that
   a plurality of bearing rollers (60) is arranged on the annular receptacle (50), by means of which rollers the guide tube (20) is mounted on the retainer (12) so as to be rotatable about the drilling axis (5) and axially fixed with respect to the drilling axis (5).
6. Device according to claim 4 or 5,
   characterized in that
   the annular receptacle (50) is formed having two pivot arms (52), which are mounted so as to be pivotable between a closed operating position, in which the pivot arms (52) are pivoted together in order to form the annular receptacle (50) and are interconnected by means of a detachable connection means (54), and an open position, in which the pivot arms (52) are pivoted apart from one another laterally.
7. Device according to any of claims 1 to 6,
   characterized in that
   the guide tube (20) is separable for the purpose of opening.
8. Device according to any of claims 1 to 7,
   characterized in that
   the retainer (12) comprises a carriage guide (16) for displaceable guidance along the mast of the drill, and a fixing means for fixing the retainer (12) on the mast.
9. Drill

   comprising an undercarriage, an upper structure mounted thereon, and a mast, along which a drilling drive comprising a driven auger is displaceably mounted, characterized in that

   a device (10) according to any of claims 1 to 8 is arranged.
10. Method for making a drilled hole in the ground using a drill according to claim 9, wherein an auger for forming the drilled hole is screwed into the ground and subsequently drawn again,
    characterized in that
    during pulling of the auger, remaining ground material is cleared from a helix gap of the auger by means of a device (10) according to any of claims 1 to 8.

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