Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C5/00—Milling-cutters
  • B23C5/02—Milling-cutters characterised by the shape of the cutter
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C5/00—Milling-cutters
  • B23C5/16—Milling-cutters characterised by physical features other than shape
  • B23C5/20—Milling-cutters characterised by physical features other than shape with removable cutter bits or teeth or cutting inserts
  • B23C5/202—Plate-like cutting inserts with special form
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C2200/00—Details of milling cutting inserts
  • B23C2200/12—Side or flank surfaces
  • B23C2200/125—Side or flank surfaces discontinuous
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C2200/00—Details of milling cutting inserts
  • B23C2200/12—Side or flank surfaces
  • B23C2200/128—Side or flank surfaces with one or more grooves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C2200/00—Details of milling cutting inserts
  • B23C2200/20—Top or side views of the cutting edge
  • B23C2200/205—Discontinuous cutting edges
• • 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
  • Y10T407/00—Cutters, for shaping
  • Y10T407/23—Cutters, for shaping including tool having plural alternatively usable cutting edges
  • Y10T407/235—Cutters, for shaping including tool having plural alternatively usable cutting edges with integral chip breaker, guide or deflector
• • 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
  • Y10T407/00—Cutters, for shaping
  • Y10T407/24—Cutters, for shaping with chip breaker, guide or deflector
• • 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
  • Y10T407/00—Cutters, for shaping
  • Y10T407/24—Cutters, for shaping with chip breaker, guide or deflector
  • Y10T407/245—Cutters, for shaping with chip breaker, guide or deflector comprising concave surface in cutting face of tool

Definitions

• the present invention relates to a tool and a cutting insert for milling according to the preambles of the independent claims.
• the U.S. Patent Specifications Serial Nos. 5,145,295, 5,207,538 and 5,078,550 show milling inserts of the above-captioned type.
• Each known cutting insert comprises planar major sides that during localization in a milling body or a grinding fixture can make the positioning unstable due to dust collections. The instability brings drawbacks for the results from the milling operation and from the grinding of the cutting edges. In addition the known cutting insert demands a lot of grinding when producing the cutting edges.
• the U.S. Patent Specification Serial No. 5,803,674 discloses a milling insert that has a ledge extending circumferentially and in the plane of the associated support surface.
• One object of the present invention is to provide a tool and a cutting insert for milling, which enables rigid localization of the cutting insert in both the milling body and the grinding fixture.
• Another object of the present invention is to provide a cutting insert for milling, which reduces the amount of material to grind. Still another object of the present invention is to provide a cutting insert for milling, which increases the geometrical freedom during grinding.
• Still another object of the present invention is to provide a cutting insert for milling, which reduces th ⁇ environmental pollution at grinding.
• Still another object of the present invention is to provide a tool and a cutting insert for milling, at which the extension of flank wear is predetermined.
• Figs. 1A and 1 B show a cutting insert according to the present invention in a top view and a bottom view, respectively.
• Fig. 2 shows the cutting insert in a side view.
• Fig. 3 shows the cutting insert in a cross section according to line Ill-Ill in Fig. 1A.
• Fig. 4 shows the cutting insert in a perspective view.
• Fig. 5 shows an enlarged cross section of a cutting corner according to the line V in Fig. 1A.
• Fig. 6 shows an enlarged cross section of a cutting corner according to the line VI in Fig. 1A.
• Fig. 7 shows cutting inserts according to the present invention mounted to a milling cutter body.
• a one-sided cutting insert 10 for milling according to the present invention is shown, which has a parallelepipedical basic shape and is manufactured from directly pressed cemented carbide.
• cemented carbide is here meant WC, TiC, TaC, NbC, etc in sintered combination with a binder metal such as for example Co or Ni.
• the cutting insert is to be mounted in a milling body, not shown, intended to be rotated in a milling machine.
• the milling body comprises at least one pocket to receive the parallelepipedical cutting insert.
• the cutting insert 10 comprises two, in a top view substantially parallel, major sides 11 , 12 and them uniting minor sides 13, 14 as well as upper and lower sides 15 and 16.
• the upper side 14 forms major cutting edges 17, 18 at lines of intersection with the major sides 11 , 12.
• the major cutting edges slope in opposite directions such that each edge forms an acute angle with the lower side 16. Thereby they give the opposite sides of the cutting insert increased, but oppositely directed axial angles.
• Each major cutting edge increases the tool's operative, positive axial angle when mounted in the cutting insert pocket in the milling body.
• the upper side 15 forms minor cutting edges or wiper edges 19, 20 at lines of intersection with a smaller portion of each minor side 13, 14.
• the major cutting edge 17, 18 and the respective associated minor cutting edge 19, 20 form a pair of cutting edges which is active during the milling while the other pair is passive. Two connected edges intersect in the area of a cutting corner 28.
• the cutting corner defines a bisector B which divides the corner into two equal angles.
• the bisector B does not intersect the radius center of the corner 28, 29.
• the upper side constitutes a chip surface in the area of the cutting edges and forms an edge angle with the major and the minor sides which is smaller than 90°, i.e. the cutting insert has a positive basic shape.
• the chip surface 15 forms a, preferably incrementally varying, positive rake angle in order to cut easy in the work piece.
• the lower side 16 forms an obtuse inner angle with the associated parts 24-27 of the minor and major sides in order to obtain clearance in relation to the work piece.
• a centrally placed hole 21 is provided to receive a fastening device such as a screw at mounting in the milling body 40, Fig. 7.
• the milling cutter is preferably provided for shoulder milling of 90° corners.
• Each pair of cutting edges 17, 19 and 18, 20 connects in direction towards the lower side 16 to a ledge or protruding first clearance surface 22 and 23, respectively.
• the ledge 22, 23 projects substantially outside the planes P1 , P2 containing the major parts of the minor and major sides, i.e. parts 24-27.
• the ledge has a greatest height in the magnitude of 0.4 to 2 mm or about 10-20 % of the height of the cutting insert 10.
• the ledge 22B, 23B is higher at the minor cutting edge, see H1 in Fig. 5, than at 22A, 22B at the major cutting edge, see H2 in Fig. 6.
• the ledge 23B is shorter than the length of the minor side 13 for reducing grinding work.
• the remaining part of the minor side edge is not intended to cut.
• the ledge projects in the interval from about 0.02 to 0.1 mm at line Ill-Ill in Fig. 1A.
• the distance L is measured perpendicularly from an imaginary extension line of the major cutting edge 18 to about a quarter of the length of the minor side 13, 14.
• the ledge thus projects relative to the remaining clearance surfaces, such that advanced grinding of the cutting edges 17-20 can done by conventional grinding methods by grinding the ledge simultaneously as a minimum of material need be machined, which in addition reduces the environmental pollution during grinding. Furthermore, the ledge acts as protection for the milling body at a cutting edge breakage.
• the lower side 16 forms, as stated above, obtuse inner angles with the parts 24- 27 of associated minor and major sides, which parts will constitute positioning surfaces in a grinding fixture and a milling body. Said parts are directly pressed and consequently shall not be ground.
• the recesses 30, 31 are formed in the parts 24, 25 contained by the major sides.
• the recesses 30, 31 are substantially rectangular and are placed longitudinally centrally to reduce the surface on the parts 24, 25 in such a way that the available surface in the plane P1 is displaced in direction towards the corners of the cutting insert.
• Each recess 30 and 31 is of the same size as or most preferably somewhat greater than each abutment surface 24A, 24B and 25A, 25B, respectively, which are formed at each side of each recess.
• Each recess 30, 31 has an essentially concave shape and extends in the height direction from close to the lower side 16 to close to the ledge 23, 24 such that neither the size of the lower side nor the strength of the ledge is influenced.
• the cutting edges 17-20 connect to a reinforcing chamfer 32, Figs. 5 and 6, which have a width W along the major cutting edges 17, 18 and the minor cutting edges 19, 20 and a greater width at the cutting corners 28 substantially symmetrically about the bisector B. Thereby the strength at the cutting corners is increased.
• a bevel 32 forms an acute angle with a plane P3 parallel with the lower side 16.
• the angle ⁇ 1 is about 13° and at the major cutting edge, according to Fig. 6, the angle ⁇ 2 is about 9°.
• the present invention thus relates to a tool and a cutting insert for milling, which enables rigid localization of the cutting insert in both the milling body and the grinding fixture, whereby the amount of material to grind is reduced and the grinding possibilities are increased.
• the surface on which flank wear occurs is predetermined by the height of the ledge.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Milling Processes (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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ID=20412540

Family Applications (1)

Country Status (9)

Cited By (5)

Families Citing this family (75)

Citations (2)

Family Cites Families (10)

• 1998
  • 1998-09-08 SE SE9803056A patent/SE514032C2/sv not_active IP Right Cessation
• 1999
  • 1999-09-02 JP JP2000568622A patent/JP2002524275A/ja active Pending
  • 1999-09-02 KR KR1020017002976A patent/KR100643224B1/ko not_active Expired - Lifetime
  • 1999-09-02 DE DE69915654T patent/DE69915654T2/de not_active Expired - Lifetime
  • 1999-09-02 WO PCT/SE1999/001516 patent/WO2000013831A1/en not_active Ceased
  • 1999-09-02 HK HK02102154.6A patent/HK1040658B/zh not_active IP Right Cessation
  • 1999-09-02 EP EP99946550A patent/EP1112137B1/en not_active Expired - Lifetime
  • 1999-09-02 CN CN99810471A patent/CN1113719C/zh not_active Expired - Lifetime
  • 1999-09-08 US US09/391,397 patent/US6142716A/en not_active Expired - Lifetime

Patent Citations (2)

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