DRILL BROWS AND METHOD FOR MAKING A BOIL IN THE GROUND

Abstract

Drill bucket with a tubular base body (20), on the upper side of which a connecting device to a drill rod is arranged and on the lower side of which a bottom (30) is hingedly mounted, wherein a cutting device (40) for removing soil material and at least one through-opening (32) are provided on the bottom (30), which is designed for the passage of removed soil material into an interior space (11) of the tubular base body (20), characterized in that at least one baffle wall (50) is provided in the interior space (11) of the tubular base body (20), wherein the at least one baffle wall (50) is inclined relative to a longitudinal axis of the tubular base body (20) and the distance of the at least one baffle wall (50) from the longitudinal axis decreases upwards, and that the baffle wall (50) extends substantially over the entire axial length of the interior space (11).the interior (11) of the tubular base body (20) is partially restricted and forms an impact surface for soil material taken up in the interior (11).

Description

The invention relates to a drill bucket with a tubular base body, on the top of which a connecting device to a drill rod is arranged and on the bottom of which a bottom is hingedly mounted, wherein a cutting device for removing soil material and at least one through-opening are provided on the bottom, which is designed for the passage of removed soil material into an interior of the tubular base body, according to the preamble of claim 1. The invention further relates to a method for producing a borehole in the ground with such a drill bucket, wherein the drill bucket is driven in a rotating manner and inserted into the ground, wherein soil material is removed and taken into an interior of a tubular base body of the drill bucket, and the drill bucket is pulled out of the borehole for emptying and a bottom on the tubular base body is opened, according to the preamble of claim 7. These types of drill buckets, also known as box drills, have been used for decades for creating a hole in the ground intermittently. The drill bucket is inserted into the ground by rotating a drill rod. A cutting mechanism removes soil material, which is then conveyed through an opening in the bottom of the drill bucket into an internal chamber until it reaches the desired fill level. The opening is then closed, and the drill bucket is pulled out of the borehole along with the drill rod and moved to an emptying position. The drill bucket is not emptied through the opening, but rather by unlocking and opening the bottom of the drill bucket. This allows for relatively easy emptying of the drill bucket, especially in loose soil. With cohesive soil materials, such as clay, and a relatively high fill level in the drill bucket, the soil can adhere to the bucket and not simply fall out under the influence of gravity. In such a case, it is common practice for the drill operator to vibrate the drill bucket to dislodge the adhering soil material. If this is unsuccessful or insufficient, the drilling process must be interrupted, the drill bucket lowered to ground level, and the adhering soil material manually removed by personnel. Such manual cleaning is time-consuming and therefore costly. Furthermore, personnel must enter the working area of ​​a drilling rig, which can be problematic for occupational safety reasons. A drill bucket of this type is known from US 2013 / 0 269 220 A1. Inside the drill bucket, a partition parallel to the longitudinal axis is arranged, which separates a release mechanism for the hinged bottom from the receiving chamber for drill cuttings. US 1 210 196 A teaches a cement conveying bucket with a downward-facing slope. The invention is based on the objective of providing a drilling bucket and a method for creating a borehole in the ground, with which a particularly reliable and safe emptying of a drilling bucket can be achieved. The problem is solved according to the invention by a drilling bucket having the features of claim 1 and a method having the features of claim 7. Preferred embodiments of the invention are specified in the dependent claims. The drilling bucket according to the invention is characterized in that at least one baffle wall is installed in the interior of the tubular base body, which extends substantially over the entire axial length of the interior, partially restricts the interior of the tubular base body and forms a baffle surface for soil material taken up in the interior. One insight of the invention is based on the fact that cohesive soil material can form a plug in the interior of a drill bucket, which remains in place despite vigorous shaking, not only due to its adhesive forces with the walls of the drill bucket, but also due to a suction or negative pressure effect. According to a fundamental concept of the invention, the cylindrical or rotationally symmetrical shape of the interior is deliberately interrupted. According to another aspect of the invention, at least one baffle is arranged in the interior, so that when the drill bucket is reversed, the soil material inside is repeatedly and deliberately pressed against this baffle.On the one hand, the shape of a soil plug within the interior is altered and preferably reduced in size so that a space is formed along the plug, thus counteracting the formation of a negative pressure between the upper side of the soil plug and the drill bucket. On the other hand, when the drill bucket is rotated in reverse, the baffle wall according to the invention exerts an additional force on the soil material in the circumferential direction of the drill bucket, thereby facilitating the overcoming of the lateral adhesive forces of the soil material in the drill bucket by a circumferential movement of the soil material. The drilling bucket according to the invention significantly facilitates the loosening of soil material, particularly cohesive soil material, within the bucket, thus practically eliminating or at least largely reducing the need for manual emptying by personnel. This not only increases occupational safety but also ensures a reliable and efficient drilling process using a drilling bucket. A preferred embodiment of the invention consists in the at least one baffle wall having an inlet radius and / or an outlet radius. This ensures that, despite the baffle wall provided in the drill bucket, the excavated soil material is introduced into the interior of the tubular base body with minimal friction during drilling. In principle, a number of baffles can be provided on the inside of the tubular base. A particularly advantageous design of the drill bucket is achieved by providing two baffles positioned opposite each other inside. This results in a mutual reinforcement of the impact forces when the drill bucket is shaken by a reversing rotation. Furthermore, a preferred embodiment of the invention can be achieved by having the tubular base body be cylindrical or conical. A cylindrical shape is particularly economical to manufacture. A conical shape of the base body, which tapers towards its top, facilitates the removal of adhering soil material, especially a soil plug in the interior. According to the invention, the effect of loosening the soil material is further improved by the fact that at least one impact wall is inclined relative to a longitudinal axis of the tubular base body. The inclination is designed such that the distance of the impact wall from the longitudinal axis decreases upwards. In principle, the at least one baffle wall can be integrally formed with the tubular base body or be formed in one piece with it. According to a further development of the invention, it is particularly advantageous that the at least one baffle wall separates a rear compartment from the interior, in which lines or a rod are arranged. The line can be a hose or a ventilation duct extending along the drill bucket in the rear compartment. Furthermore, a locking mechanism, in particular a rod for unlocking the base plate, can also be provided in the rear compartment, the rod preferably extending from an underside of the drill bucket to an upper side and beyond. Preferably, the baffle wall is a plate-shaped element that is inserted into the base body, preferably welded in place. Generally, when drilling cohesive soil, a sealing plate is not required to close the at least one through-hole in the bottom of the drill bucket, since the cohesive soil largely remains inside when the drill bucket is withdrawn from the borehole. However, if soil layers containing loose material, such as sand or gravel, are also to be drilled, one embodiment of the invention prefers that the bottom have a rotatable sealing plate with which the at least one through-hole can be closed. The sealing plate is rotatably mounted such that it is moved into an open position in one direction of drilling rotation, while in the opposite direction of rotation, the sealing plate is rotated relative to the bottom, thus moving it into a closed position in which it closes the at least one through-hole. With regard to the method, the invention is characterized in that the drill bucket is rotated in reverse during emptying, whereby soil material taken up in the drill bucket is pressed against at least one impact wall and the soil material is selectively compacted and deformed to make it easier to remove from the interior. The process can be carried out in particular with the previously described drill bucket, which is attached to a conventional earth auger. The drill rod can be a simple drill rod or a telescopic drill string, a so-called Kelly bar. A reversing rotation of the drill bucket can only take place after the bottom has been opened, or even when the bottom is still in its closed position on the tubular base, so that the compacted soil material forms an easily removable plug. According to a further development of the invention, a preferred method variant consists in filling the drilled borehole with a preferably hardenable mass, thereby producing a pile-shaped foundation element. In particular, a foundation pile can be produced with a concrete mass. The invention is further described below with reference to a preferred embodiment, which is shown schematically in the accompanying drawings. The drawings show: Fig. 1 a perspective view of a drill bucket according to the invention; Fig. 2 a partially sectioned side view of the drill bucket of Fig. 1; Fig. 3 a side view of the drill bucket of Fig. 1 and Fig. 2; and Fig. 4 a cross-sectional view according to section AA of Fig. 3. A drilling bucket 10 according to the invention, as shown in Fig. 1, has a cylindrical, tubular base body 20, on the upper side of which a connecting device 12 for a drill rod is attached. On its underside, facing the ground, the tubular base body 20 has a plate-shaped bottom 30, on which a cutting device 40 for removing soil material is arranged. The cutting device 40 comprises a centrally projecting pilot cutting edge 42, from which several cutting teeth 44 extend helically to a through-opening 32 in the bottom 30. The through-opening 32 is designed to allow the removed soil material to pass into an interior 11 of the tubular base body 20. To empty the interior 11, the bottom 30 can be opened from a locked position, as shown in Fig. 1, by means of a locking device 60. The locking device 60 comprises an actuating bolt 64 on the upper side of the tubular base body 20 in the area of ​​the connecting device 12. As shown in more detail in Fig. 2, a spring-loaded actuating bolt 64 actuates a linkage 62 inside the tubular base body 20, whereby a lower locking section 66 releases the plate-shaped bottom 30. The plate-shaped bottom 30 can be pivoted downwards via a lateral pivot joint 36, which is oriented transversely to a longitudinal or drilling axis of the drill bucket 10. In this pivoted position, soil material can be emptied from the interior 11 at a discharge point. To close the bottom 30, it is simply pressed downwards against the ground together with the drill bucket 10, whereby the bottom 30 pivots back and is locked again to the locking section 66 in a substantially horizontal position. The linkage 62 is arranged in a rear space 14 of the tubular base body 20, wherein the rear space 14 is separated from the interior space 11 provided for receiving the soil material by means of a baffle wall 50, as is shown in more detail in Fig. 3 and Fig. 4. In the illustrated drilling bucket 10 according to the invention, a total of two substantially opposing baffle walls 50 are arranged in the interior 11, extending along the entire interior 11 from the bottom 30 to a cover plate 22 on the top of the tubular base body 20. An opening 24 for pressure equalization is provided in the cover plate 22. The baffle walls 50 narrow the interior 11 of the tubular base body 20, with inlet radii 52 provided to facilitate the flow and distribution of the excavated soil material into the interior 11. These inlet radii adjoin a flat, plate-shaped section of the baffle walls 50 and form a transition to an inner wall of the tubular base body 20, at least on one side of the baffle wall 50. The baffles 50 are arranged at an angle to the longitudinal axis of the drill bucket 10, with the distance of the baffles 50 to the longitudinal axis decreasing upwards. Thus, the interior 11 is conically tapered upwards, which facilitates the emptying of the soil material from the interior 11 downwards. The rear space 14, which is separated from the interior 11 by the impact walls 50 and is formed between the impact walls 50 and the inner wall of the tubular base body 20, serves to accommodate the linkage 62 of the locking device 60 or other lines and components not shown here.

Claims

Drill bucket with a tubular base body (20), on the upper side of which a connecting device to a drill rod is arranged and on the lower side of which a bottom (30) is hingedly mounted, wherein a cutting device (40) for removing soil material and at least one through-opening (32) are provided on the bottom (30), which is designed for the passage of removed soil material into an interior space (11) of the tubular base body (20), characterized in that at least one baffle wall (50) is provided in the interior space (11) of the tubular base body (20), wherein the at least one baffle wall (50) is inclined relative to a longitudinal axis of the tubular base body (20) and the distance of the at least one baffle wall (50) from the longitudinal axis decreases upwards, and that the baffle wall (50) extends substantially over the entire axial length of the interior space (11).the interior (11) of the tubular base body (20) is partially restricted and forms an impact surface for soil material taken up in the interior (11). Drill bucket according to claim 1, characterized in that the at least one baffle wall (50) has an inlet radius (52) and / or an outlet radius. Drill bucket according to claim 1 or 2, characterized in that two impact walls (50) are provided which are opposite each other in the interior (11). Drill bucket according to one of claims 1 to 3, characterized in that the tubular base body (20) is cylindrical or conical on the inside. Drill bucket according to one of claims 1 to 4, characterized in that a rear space (14) is separated from the interior (11) by the at least one baffle wall (50), in which lines and / or a rod (62) are arranged. Drill bucket according to one of claims 1 to 5, characterized in that the bottom (30) has a rotatable closure plate with which the at least one through-opening (32) can be closed. A method for producing a borehole in the ground using a drill bucket (10) according to any one of claims 1 to 6, wherein the drill bucket (10) is driven in a rotating manner and inserted into the ground, whereby soil material is removed and received into an interior (11) of a tubular base body (20) of the drill bucket (10), and the drill bucket (10) is withdrawn from the borehole for emptying and a bottom (30) of the tubular base body (20) is opened, characterized in that the drill bucket (10) is rotated in reverse during emptying, wherein soil material received in the drill bucket (10) is pressed against at least one baffle wall (50) and the soil material is thereby selectively compacted and deformed to facilitate its removal from the interior (11). Method according to claim 7, characterized in that the borehole created is filled with a curable mass, whereby a pile-shaped foundation element is produced.

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