Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B10/00—Drill bits
  • E21B10/44—Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts
  • E21B10/445—Bits with helical conveying portion, e.g. screw type bits; Augers with leading portion or with detachable parts percussion type, e.g. for masonry

Definitions

• the invention relates to a drilling tool, in particular a rock drill according to the preamble of claim 1.
• Known drilling tools for processing rock consist of a drill head with an inserted hard metal cutting plate, an adjoining spiral shaft with a spiral conveying spiral and a clamping shaft for inserting the drilling tool into a drive machine, such as an impact drill or the like.
• the spiral conveyor spiral of rock drills are machined or also non-cutting, in order to introduce the flutes into the generally cylindrical starting material.
• the main task of rock drill bits in rock drills is to challenge material loosened by the hard metal cutting edge, ie the drilling dust or cuttings, from the borehole.
• the conveying groove cross-section is selected approximately in known drills in such a way that a diameter ratio of the core diameter to the conveying helix diameter of approximately 0.5 results. Too large a conveying groove cross section has the disadvantage that the core diameter of the conveying helix is greatly weakened, which can lead to breaks. Apart from that elaborate production of the conveyor grooves also very high-quality alloy tool steels have to be used in order to meet the requirements.
• the invention has for its object to provide a drilling tool and in particular a rock drill for rotating and / or rotating impact, which is extremely inexpensive to manufacture and yet has sufficiently good conveying properties of drilling dust.
• a drilling tool and in particular a rock drill for rotating and / or rotating impact which is extremely inexpensive to manufacture and yet has sufficiently good conveying properties of drilling dust.
• the invention is based on the knowledge that the drilling performance of drilling tools is also largely determined by the achievable delivery volume of drilling dust in the drilling dust grooves.
• conventional drills there are generally one or two, exceptionally also three conveyor helical grooves available, which must have a corresponding groove cross-section in order to enable the drilling dust to be transported away.
• the required groove cross section basically weakens the core cross section of the drilling tool in the helical area, which is particularly the case with drilling tools with small diameters of e.g. 2 mm to 6 mm can lead to strength problems in the spiral shaft.
• the present invention can solve the problem of the weakening of the core cross section as a result of introduced spiral spiral grooves according to the invention by replacing two spiral spiral grooves, e.g. six such grooves are used, which can be twisted e.g. of a hexagon steel.
• a profile rod which is twisted only in the area of the conveying helix and has a polygonal cross section forms a multiplicity of conveying spirals which bring about very positive drilling dust transport.
• the twisting, in particular of a profile bar with a hexagonal cross section in the area of the conveyor helix therefore leads to usable results, especially for drilling tools with smaller nominal diameters when used in commercially available turning or screw drilling machines.
• the starting material for the complete drilling tool is selected in such a way that the clamping shank forms clamping surfaces for use in a commercially available three-jaw chuck of a turning or impact drill, i.e. the polygonal profile must have at least three clamping surfaces that are offset by 120 °. This ensures a positive clamping of the drill shaft, i.e. a turning of the drilling tool in the jaw chuck of the drilling machine is almost impossible.
• FIG. 1 is a perspective view of a rock drill with a hexagonal cross section
• FIG. 2 shows a side view of the rock drill according to FIG. 1,
• FIG. 2a is a plan view of the rock drill of FIG. 2,
• FIG. 2b is an enlarged view of FIG. 2a
• Fig. 4 shows a further variant of the basic profile
• Fig. 5 shows a further variant of the basic profile.
• the rock drill 1 shown in FIGS. 1 to 3 has a drill head 2, a helical shank 3 and a clamping shank 4.
• the drill head 2 has a commercially available, roof-shaped hard metal cutting plate 5 which, with its outer diameter D, forms the nominal drill diameter.
• a commercially available hexagonal steel is used as the starting material for producing the rock drill, as is available in a wide variety of dimensions, for example in DIN 176, DIN 1015 or DIN 59110 (hexagonal wire rod).
• the key width s is used to determine the respective dimensions.
• Diagonal 8 has a length of d ⁇ . If such a hexagonal profile is twisted as shown in FIGS. 1 to 3, the longitudinal edges 7 'lie on the circumference 10 of the conveyor helix thus formed. 3, the hexagonal profile 6 of the
• the ratio of the diameter D of the hard metal cutting plate 5 to the diameter d 1 of the conveying helix 3 and thus the protrusion of the hard metal cutting plate is selected in conventional dimensions by conventional drilling tools.
• Drilling tests have shown that good drilling results can be achieved with such a tool with a hexagonal profile in commercially available impact drills. It is of great advantage that the manufacturing costs for such a drilling tool can be reduced enormously compared to the usual manufacturing costs, since no machining is required to produce the conveyor helix.
• a particular advantage of using such profile bars, e.g. Hexagonal profiles also lie in the shape of the clamping shank, the key surfaces 11 of which, due to their arrangement, automatically form clamping surfaces in a conventional three-jaw chuck of an impact drill or the like.
• the drilling tool can be clamped firmly and positively into the processing machine without the otherwise very frequent spinning of the drilling tool in the processing machine.
• the clamping jaws of the three-jaw chuck do not offer sufficient support for a conventional circular-cylindrical clamping shank due to the closure on frequently used drilling machines.
• the positive clamping by means of a hexagonal clamping shaft therefore also offers considerable advantages.
• the invention can be extended by the designs of the profile bars 6 ', 6'', for example according to FIGS. 4 and 5.
• the insert 5 was only drawn in with a dashed line for a better representation of the profile.
• a triangular profile bar is selected as the starting material, with three flat clamping surfaces 11 ′ which are connected to one another via an arc section 14.
• the arc angle ⁇ of the clamping surfaces 11 ' is chosen to be somewhat larger than the arc angle ⁇ of the circular arc sections 14. This results in larger drilling dust grooves 12' with a corresponding twisting of this profile.
• the clamping surfaces 11 ' can move further to the center of the circle 15, as required, in order to further enlarge the drilling dust grooves 12'. As a result, the circular arc sections 14 are reduced accordingly.
• the clamping surface 16 is shown in FIG. 4 as an example of such a displacement. Of course, three such clamping surfaces 16 are arranged at a corresponding rotation angle of 120 °.
• FIG. 5 corresponds to that according to FIG. 4, however the clamping surfaces 11 ′′ are concave, i.e. 15 curved surfaces formed inwards to the center of the circle. This also results in a further enlargement of the drilling dust groove 12 ′′.
• the clamping surfaces 11 ′′ form the form-fitting receiving elements for a three-jaw chuck of the drilling machine. The same profile is twisted in the area of the helical shaft as described in relation to FIGS. 1 to 3 and thus forms the necessary drilling dust grooves.
• rod-shaped starting materials according to Figures 4 and 5 can also be rolled or drawn as inexpensive Special profiles are available or are produced to form the drilling tool according to the invention.

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• Engineering & Computer Science (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Processing Of Stones Or Stones Resemblance Materials (AREA)
• Drilling Tools (AREA)
• Earth Drilling (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Cited By (1)

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Citations (6)

• 1997
  • 1997-05-30 DE DE19722517A patent/DE19722517A1/de not_active Withdrawn
• 1998
  • 1998-05-15 DK DK98934749T patent/DK0985081T3/da active
  • 1998-05-15 DE DE59806280T patent/DE59806280D1/de not_active Expired - Fee Related
  • 1998-05-15 WO PCT/DE1998/001377 patent/WO1998054436A1/de active IP Right Grant
  • 1998-05-15 EP EP98934749A patent/EP0985081B1/de not_active Expired - Lifetime
  • 1998-05-15 CN CN98805670A patent/CN1259189A/zh active Pending

Patent Citations (6)

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