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

• Drilling tool in particular rock drill
• the invention relates to a drilling tool, in particular a rock drill according to the preamble of claim 1.
• Drilling tools and in particular rock drills generally consist of a drill head equipped with a hard metal cutting insert, a helical shaft with a conveying helix for drilling dust or drilling cuttings and a clamping shank which is designed depending on the machine type of the drive machine.
• the feed spiral is usually produced by machining, but possibly also without cutting.
• Drilling tools are also known from DE 69 33 778-U or also from EP 0 361 189 AI which consist of profiled bars with one or more attached wings or ribs, the conveying helix being produced by twisting such a rod-shaped or rod-shaped blank .
• the clamping end of the drilling tool according to DE 69 33 778 forms a positive entrainment in a conventional chuck with three movable jaws (3-jaw chuck) z.
• a rod-shaped blank with at least one lateral rib is used used, which is twisted into a conveyor spiral.
• the clamping shaft is designed as a hexagonal profile, which is attached in one piece to the conveyor spiral.
• each rod-shaped starting material must be provided with at least one, preferably two or even three longitudinal ribs or wings in order to obtain a sufficiently large helical groove for the transport of drilling dust.
• this requires more expensive, not commercially available bar material as the starting product.
• the invention has for its object to provide an inexpensive manufacture for a drilling tool, in particular a machining operation for the production of the feed spiral should be dispensed with.
• This object is achieved on the basis of a drilling tool according to the preamble of claim 1 by the characterizing features of claim 1.
• Advantageous and expedient developments of the drilling tool according to claim 1 are specified in the subclaims.
• the invention is based on the astonishing knowledge per se that the production of an effective conveyor helix is also possible through a ribless or wingless polygonal profile which is twisted to produce the conveyor helix.
• the prior art usually proposes profiles with at least one rib-shaped attachment for this purpose.
• the present invention uses a polygonal profile bar such as z. B. a conventional hexagonal steel with a hexagonal profile as a blank, which is twisted into a spiral conveyor.
• the invention is based on the knowledge that the drilling performance of drilling tools is largely determined by what can be achieved Flow rate of drilling dust in the drilling dust grooves is determined.
• Flow rate of drilling dust in the drilling dust grooves is determined.
• conventional drills there are generally one or two, in exceptional cases 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 can lead to strength problems in the helical shaft, in particular in the case of drilling tools with small diameters of, for example, 2 mm to 6 mm.
• 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 cross-sectionally hexagonal profile bar in the area of the conveyor helix therefore leads to useful results, in particular for drilling tools with smaller nominal diameters when used in commercially available turning or impact drills.
• Hexagonal, square or triangular profiles can be used, the latter resulting in enlarged drilling dust grooves when twisted.
• such rod-shaped blanks with a clamping shank required depending on the application, for. B. in an extrusion process or a forging process and the spiral section is used to produce the spiral conveyor z. B. subsequently twisted.
• a special clamping shank can also be subsequently connected to a correspondingly produced, possibly already twisted conveyor spiral section by means of a suitable welding process.
• a rod-shaped starting material can also be used as the polygonal profile, which has at least three symmetrically arranged and evenly or preferably concavely curved side faces, which in twisted form lead to enlarged drilling dust grooves.
• Such a polygonal profile can also form the helical shaft in a twisted form and the clamping shaft in an untwisted form.
• a hard metal insert is used on the face side of such a manufactured and twisted profile to form the drill head.
• FIG. 1 is a perspective view of a first embodiment of a drilling tool
• FIG. 2 shows a side view of the drilling tool according to FIG. 1,
• FIG. 2a shows a plan view of the drilling tool according to FIG. 2, 2b is an enlarged view of the illustration of FIG. 2a,
• FIG. 4 shows a further exemplary embodiment with a profile bar which is approximately triangular in cross section in the direction of the section line I-I in FIG. 2,
• FIG. 5 shows the embodiment of FIG. 4 with concave side surfaces
• FIGS. 1 to 3 shows an initial blank in side view for producing the drilling tool according to FIGS. 1 to 3,
• Fig. 6a is a plan view of the blank according to Fig. 6 and
• FIG. 7 shows a side view of the blank according to FIG. 6.
• the rock drill 1 shown in FIGS. 1 to 3 consists in a first embodiment of a drill head 2, a helical shank 3 and a clamping shank 4.
• the drill head has a commercially available roof-shaped hard metal cutting plate 5 which forms the nominal drill diameter D.
• the helical shaft 3 consists of a hexagonal profile rod 6 as the starting material, as is shown in each case in a side view in FIGS. 6, 7.
• This hexagonal profile bar can 6 and 7 can be produced in an extrusion process or a forging process together with a cylindrical clamping shank 4, the cylindrical clamping shank 4 having the diameter d 3 .
• the hexagonal profile 6 is characterized by its width across flats s, the diagonal 8 being represented by the corner points 7 or by the longitudinal edges 7 'in FIG. 2b. If you twist such a profile about the longitudinal central axis 9 z. B. by 360 °, the result is shown in FIGS. 1 to 3 spiral conveyor with a circumference 10 with a
• Diameter di which corresponds to the length of the diagonals 8 through the corner points 7.
• the helix angle ⁇ of the groove increase, measured in relation to the longitudinal central axis, is 9 ⁇ 20-40 °.
• the six key surfaces 11 of the hexagonal profile rod thus form the bottom of the drill groove groove in the twisted state, while the longitudinal edges 7 "of the hexagon profile form the line-shaped boundaries of the respective drill dust groove 12.
• the drill dust groove 12 is consequently defined by the surface sections 11 and Circle 10 formed, as shown hatched in Fig. 2b.
• the circumference 13 with the diameter D forms the outer boundary of the borehole due to the formation of the hard metal cutting edge 5, so that the actual drilling dust groove is formed between the circumference 13 and the drilling dust groove base 11.
• the hexagonal profile 6 of the exemplary embodiment according to FIGS. 1 to 3 is varied in the exemplary embodiment according to FIG. 4.
• a circular basic profile 6 ' is used, with three key surfaces 11' spaced at a circumferential angle of 120 °, which are connected to one another via circular arc sections 14.
• the diameter of this circumference 14 in turn corresponds to that Diameter d in Fig. 2b. If you twist one
• Triangular profile results in the drilling dust grooves 12 'as shown in Fig. 4.
• the arc angle ⁇ of the key surfaces 11 ' is the same size or greater than the arc angle ⁇ of the circular arc sections 14.
• the angle ⁇ is z. B. ⁇ «60-70, preferably 65 °, the angle ⁇ is ⁇ « 50-60, preferably 55 °.
• the key surface 11 'for enlarging the drilling dust groove 12' in FIG. 4 can also be arranged closer to the center of the circle 15, as is indicated, for example, by the auxiliary line 16.
• the drilling dust groove 12 ′ increases when the circular arc section 14 is reduced.
• the embodiment according to FIG. 5 differs from that according to FIG. 4 essentially in that the key surfaces are designed as concave key surfaces 12 ′′ in order to further enlarge the drilling dust grooves 12 ′′.
• Such an initial profile 6 ′′ also forms the circumference d lf in the twisted state as described for FIGS . 1 to 3.
• the clamping shaft 14 with its diameter d 3 can, depending on the application, be adapted to the chuck of a hammer drill or an impact drill.
• this clamping shaft 4 is designed as a conventional hammer drilling machine clamping shaft, as is standardized for hammer drilling machines.
• connection between the spiral shaft 3 and the clamping shaft 4 takes place either via the manufacturing method by means of a Extrusion blank or a forging blank as shown in Fig. 6 and 7, wherein after the production of the blank, the feed spiral is produced by twisting the initial profile.
• a rod-shaped polygonal profile can also be used, which is clamped at two ends and subsequently twisted in opposite directions. This can be connected to the clamping shank using a suitable welding process.
• the order of the manufacturing steps can also be varied.
• clamping shank can also be used as an untwisted polygonal profile, i. H. for example as a hexagonal profile 6 'or as a cross-sectionally triangular profile 6', 6 '' according to the representations in FIGS. 2b, 4 and 5.
• the hard metal cutting insert 5 is inserted symmetrically into the triangular cross section of the twisted conveying spiral, i. H. the longitudinal axis 17 of the hard metal cutting edge points in the direction of a tip 18 of the triangular cross section.
• the polygonal profile to be twisted for the conveying helix can also be a square profile or rectangular profile, provided that this should not simultaneously serve as a clamping shaft - in the untwisted state.

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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)

Applications Claiming Priority (3)

Publications (1)

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• 1997
  • 1997-05-30 DE DE1997122518 patent/DE19722518A1/de not_active Withdrawn
• 1998
  • 1998-05-15 JP JP50008599A patent/JP2002500713A/ja active Pending
  • 1998-05-15 CN CN988056380A patent/CN1094169C/zh not_active Expired - Fee Related
  • 1998-05-15 EP EP98933546A patent/EP0985080A1/de not_active Withdrawn
  • 1998-05-15 WO PCT/DE1998/001358 patent/WO1998054434A1/de not_active Application Discontinuation

Non-Patent Citations (1)

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