Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B51/00—Tools for drilling machines
  • B23B51/02—Twist drills
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B51/00—Tools for drilling machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2228/00—Properties of materials of tools or workpieces, materials of tools or workpieces applied in a specific manner
  • B23B2228/10—Coatings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2251/00—Details of tools for drilling machines
  • B23B2251/24—Overall form of drilling tools
  • B23B2251/241—Cross sections of the diameter of the drill
  • B23B2251/244—Cross sections of the diameter of the drill decreasing in a direction towards the shank from the tool tip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2251/00—Details of tools for drilling machines
  • B23B2251/40—Flutes, i.e. chip conveying grooves
  • B23B2251/402—Flutes, i.e. chip conveying grooves with increasing depth in a direction towards the shank from the tool tip
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B51/00—Tools for drilling machines
  • B23B51/06—Drills with lubricating or cooling equipment
  • B23B51/063—Deep hole drills, e.g. ejector drills
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T408/00—Cutting by use of rotating axially moving tool
  • Y10T408/44—Cutting by use of rotating axially moving tool with means to apply transient, fluent medium to work or product
  • Y10T408/45—Cutting by use of rotating axially moving tool with means to apply transient, fluent medium to work or product including Tool with duct
  • Y10T408/455—Conducting channel extending to end of Tool

Definitions

• the present invention relates to a drill, in particular a deep hole drill, with a shaft for clamping in a corresponding chuck and a flute having portion whose length is more than three times the nominal diameter and whose front end is formed by a drill bit, which by the front side of the front end of the drill arranged main cutting edges is defined.
• Corresponding drills have been known for a long time.
• the invention is particularly directed to so-called deep hole drills in which the flute portion (hereinafter “flute nut portion”) is at least six times, and possibly more than ten times, the nominal diameter of the drill
• the features and principles of the present invention are Advantage also applicable to drills in which the ratio of the length of the flute section to the nominal diameter of the drill is below 8 and therefore usually not referred to as a deep hole drill, even if the benefits of the measures according to the invention for use in such shorter drills not necessarily be required to like.
• the present invention seeks to provide a drill with the features mentioned above, which is able, in continuous operation very deep holes of more than 10 times to more than the 20th - Perform times the nominal diameter and it works very economical.
• the drill tip and at least the adjoining the drill tip portion of the flutes to a distance T from the tip of the drill, which is at most three times the nominal diameter, coated with a hard material, while at least the flutes in the Area not more than T away from the tip, are not coated with the hard material
• the drill core has a maximum diameter in the area of the drill bit or near the drill bit that is at least 30% to 55% of the nominal diameter of the drill, wherein this core diameter tapers to a minimum diameter of at most 20% to 50% of the nominal diameter towards a region of the flute portion closer to the shank, the difference between the maximum core diameter in the region of the tip and the minimum core diameter in the region closer to the clamping profile. cut at least 5% of the nominal diameter diameter is.
• a drill with this combination of features has proven to be surprisingly favorable in terms of its chipbreaking and chip handling properties.
• the coated tip which is known per se for purposes of increasing the service life and improving the wear resistance of the drill, apparently also contributes to a favorable chip forming.
• the core diameter decreases from the tip to a region closer to the shaft, so that the flutes become correspondingly deeper and can have a larger cross-section. This facilitates the chip transport through the flutes, in particular with regard to the fact that the chip removal takes place predominantly by cooling lubricant or compressed air, but to a certain extent by the new chips produced at the drill tip.
• the flutes preferably extend helically, which further facilitates chip removal, since the chips then partially rub against the drill wall and are simultaneously driven through the base or the wall of the flute, which in effect produces a force component directed toward the shank on the chips ,
• this may be the pitch of the flutes or the slope of the flutes limiting minor cutting on the outer circumference of the drill to be relatively small, i. with the axis a relatively large angle of at least 20, preferably at least 30 ° include.
• the coating in the interior of the grooves is limited to a maximum of three times the diameter of the drill bit, measured from the tip.
• the hard coating usually has a larger coefficient of friction for the chips than the ground structure of the flutes of the uncoated drill. For this reason, it is favorable for the chip transport, if for the greater part of the length of the flutes a lower friction is present, so the flutes remain uncoated.
• the flutes can also be polished.
• outer surfaces of the webs in particular the round bevels, could also be coated over the entire length of the flute part with a hard material.
• the webs or round bevels it is not absolutely necessary for the webs or round bevels to be coated on their outer side, but the round bevels in the front region adjacent to the tip are expediently also coated, where the inner surfaces of the flutes are also coated.
• flutes and webs are coated over the same axial length overall. This counteracts the wear of the round bevels in the area adjacent to the tip.
• the outer diameter of the drill tapers, starting from a maximum diameter at the drill tip, more precisely at the transition of the drill bit to the flute portion, in the direction of the shaft, but to a lesser extent than the core.
• the taper of the outer diameter between 1 .mu.m and 8 .mu.m per mm distance from the drill tip or of the - -
• Point of maximum diameter is.
• This diameter taper takes place, seen from the top, over an axial length of at most 8 times, preferably at most 5 times and at least 2 times the nominal diameter of the drill and in the remaining area up to the clamping end, the outer diameter remains the drill constant.
• the degree of taper and depending on the nominal diameter of the drill then has, for example, at diameters above 2 mm in the flute adjacent to the shaft section by at least 4 ⁇ m and for example up to about 1 mm smaller diameter than in the region of the drill bit.
• the maximum core diameter at or near the tip of the drill is at least 35% and at most 50% of the nominal diameter of the drill. Furthermore, it is preferable that the difference between the maximum core diameter at the tip of the drill and the minimum core diameter farther back in the vicinity of the chucking portion is at most 20% of the nominal diameter. Preferred are differences between maximum and minimum core diameter in the order of 5 to 12% of the nominal diameter, preferably between 6 and 10%.
• the measure T over which the flutes and optionally also the outer surfaces of the webs, starting from the tip, are coated with a hard material, about 0.5 to 2.5 times and more preferably between the 1 and 1.5 times the nominal diameter of the drill.
• the distance T measured from the axially rear end of the drill bit, i. from the position at which the drill has its maximum diameter or nominal diameter determined by the radially outer corners of the main cutting edges at the tip of the drill.
• the drill according to the invention in its preferred embodiment also channels for the supply of a coolant.
• FIG. 1 The single figure shows a partially sectioned schematically side view of a drill according to the invention, in which, however, the diameter is greatly increased in relation to the drill length and wherein webs and the flutes are represented only by the envelope of the round bevels, in the upper portion of a cylinder and further down to the top corresponds to a cone.
• the drill generally designated 10, has a shank 1, an adjoining flute section 2 and a drill tip 3 delimiting the front end of the flute section.
• the shank 1 is shown in a side view, while the major part of the flute cut is shown in an axial longitudinal section (but without reproducing the helical course of the flutes), in which the inner core region 4 is shown hatched.
• the drill bit 3 generally has two main blades 5 extending outwardly at an angle of between 60 and 70 degrees relative to the axis of the drill from the center or a position near the center and the outer maximum diameter through their outer ends D of the drill.
• the core diameter of the drill decreases continuously, and then at the end of Nutab- section 2 and the shaft portion 1 back to increase until finally to the full diameter of the shaft 1, where the individual flutes 6 end.
• the depth of the flutes accordingly increases, starting from the tip 3 of the drill, toward the shaft.
• the outer diameter of the drill decreases, starting from the value D at the outer cutting corners 7, in the direction of the shaft 2, over a length L which is between 2 times and 8 times the nominal diameter D.
• Drill diameter preferably in the range of 1 to 1, 5 times the diameter of the drill bit, wherein, moreover, the entire tip 3 is coated with a hard material.
• the axial length A, over which the core taper takes place, corresponds approximately to the maximum borehole depth for which the drill is provided, that is to say approximately 10 to 20 times the drill diameter D or even more.
• Maximum ratios of length to diameter, on the order of more than 40 have already been practically realized by the applicant in experiments. Where a ratio of more than 20 is particularly preferred.
• the web width can also be made relatively low from the outset.
• the cross-sectional shape of the flutes 6 corresponds in such an embodiment, for example, the so-called "UFU” cross section, as defined in the German patent application DE 196 27 436, and is thus designed for optimum chip removal.
• the flutes may be polished, possibly also in the front, coated with hard material section.
• the tapering of both the core and the outside diameter from their respective maximum to the minimum values preferably takes place continuously and in a longitudinal section or with an envelope, as shown in the figure, along a straight line, although other courses of the cross-section or outside diameter taper would be readily possible. If necessary, the rejuvenations could also take place in several stages.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Drilling Tools (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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ID=36177644

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (26)

Citations (4)

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• 2005
  • 2005-02-09 DE DE102005005982A patent/DE102005005982A1/de not_active Withdrawn
• 2006
  • 2006-02-08 DE DE502006003318T patent/DE502006003318D1/de not_active Expired - Lifetime
  • 2006-02-08 WO PCT/EP2006/050757 patent/WO2006084859A1/de not_active Ceased
  • 2006-02-08 EP EP06708103A patent/EP1846186B1/de not_active Expired - Lifetime
  • 2006-02-08 KR KR1020077020550A patent/KR20080008318A/ko not_active Withdrawn
  • 2006-02-08 CN CNA2006800043509A patent/CN101115579A/zh active Pending
  • 2006-02-08 US US11/883,917 patent/US20090047080A1/en not_active Abandoned
  • 2006-02-08 AT AT06708103T patent/ATE427177T1/de active
  • 2006-02-08 JP JP2007554551A patent/JP2008529811A/ja active Pending

Patent Citations (4)

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