Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
  • B23B27/04—Cutting-off tools
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
  • B23B27/04—Cutting-off tools
  • B23B27/045—Cutting-off tools with chip-breaking arrangements
• • 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
• • 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
  • Y10T407/25—Cutters, for shaping including cut off tool

Definitions

• the present invention relates to a cutting insert for the turning of grooves and parting operations in accordance with claim 1.
• the cutting insert according to the invention, is suitable for the turning of grooves, although it also can be used for different axial grooving and parting operations, as well as for axial and radial longitudinal turning.
• Chip breaking and chip forming are frequently of decisive importance for undisturbed output.
• Modern, high productive machines are very dependent on good chip transport. Long, uncontrollable chips can easily cause machine interruptions and rejection of parts. Chip control must therefore be given high priority and it governs to a high degree tool design.
• Cutting inserts intended for grooving operations and parting are usually clamped in a holder, which is blade shaped in order to fit into the slot produced.
• Such cutting inserts are for example known from US-A-4,778,311, US-A-4,992,008, US-A-5, 135,336 and US-A-5,423,639.
• a first purpose is to produce a cutting insert, which is well suited to give improved surface finish of the surfaces in the slot produced in a work piece.
• Fig. 1 shows a cutting insert according to the invention in a perspective view as seen obliquely from above.
• Fig. 2 shows the same cutting insert as in fig. 1 as seen straight from the side.
• Fig. 3 shows the same cutting insert as in fig. 1 as seen straight from above.
• Fig. 4 shows the same cutting insert as in fig. 1 as seen straight from its forward end
• Fig. 5 shows a sectional view V-V centrally through the insert in fig. 3.
• Fig. 1 - 5 show a cutting insert for grooving according to the invention including a body of parallelepipedic shape with an upper surface 1, a bottom surface 2, a forward end surface 3, and a rear end surface 4, having the same form as the forward end surface and mutually opposed plane parallel side faces 5, 6.
• the upper surface 1 and the bottom surface 2 of the insert are shaped with a longitudinally concave V-shaped keyway la and 2a.
• the bottom support surfaces 2b, 2c on each side of the central concave groove 2a have been correspondingly inclined and are intended to rest against the correspondingly inclined support surfaces in a blade holder in the way that is described in Swedish patent application 9703434-2, the content of which is hereby incorporated by reference, the central part of the insert is a shank portion with a cutting head formed at each end thereof.
• Each cutting head has an end surface composed of a front clearance surface 7 that by intersection with the upper surface 1 at a positive angle ⁇ forms a transverse edge 8a.
• the cutting edge 8a is circular and extends to side edges 8b with the same uniform radius.
• the cutting edges 8a, 8b have a diameter D which exceeds the perpendicular distance between the side faces 5, 6.
• side edges 8b and their side clearance faces 11, 12 are provided on insert position which protrude laterally outwardly from the insert and via an obliquely inclined break line 13 intersects the side surface 5.
• the main cutting edge could have straight contour oriented perpendicularly towards the longitudinal direction of the cutting insert whereas the side edges extend at a certain clearance angle from the longitudinal direction of said insert.
• the cutting head at each end of the insert is provided with an upper chip surface 13, which is provided with a chip forming device in the form of a number of recesses 14, each of which has concave cross-section. Between these recesses and the cutting edge there is provided a planar reinforcing chamfer 15, which reinforces the cutting edge. Said chamfer 15 is planar in shape and coincides with neutral plane P. These recesses 14 intersect with each other along edges, which extend perpendicularly towards the cutting edge.
• the central surface of the upper side of the cutting head has the form of a convexly curved surface 16, the highest position is located at the same level or somewhat below the bottom of the trail la, as best appears in fig. 5.
• the recesses 14 are provided to give the insert a positive chip angle of 5° to 30° so as to enable plastic deformation of the chip such that it becomes easier to break.
• the transition between convex surface 16 and the area confined by the surfaces la, lb, lc is formed by an upwardly inclined planar surface 17, which should be inclined 30° - 55° relatively to the neutral plane P.
• Each of the longitudinal surfaces lb, lc extends upwardly into a crest, which defines the highest level of the cutting insert portion with height h above the neutral plane P.
• each cutting head is provided with a first upper clearance surface 18 with an unbroken convex surface contour, which extends to the central cutting edge 8a.
• a concave shaped surface 19 forms the transition surface to a lower surface 20, which is displaced axially inwards towards the insert body. Both the surfaces 19 and 20 have their greatest width, which must be smaller than of the cutting head diameter D.
• the lower surface 20 is intended to serve as an axial stop surface with the cutting insert clamped into a holder.
• the surface 20 should preferably form a straight angle with the plane which encompasses the cutting insert bottom surface 2.
• the axial stop surface 20 becomes well protected under continuous machining thanks to the shoulder which is formed by the concave surface 19.
• the main cutting edge in its entirety, could extend perpendicularly towards the longitudinal direction of the cutting insert and in such a case the lower surface 20 could have same width as the cutting head.
• the intermediate surface 19 could be limited in its extent by a curved section line 21 by the intersection with the concave the intermediate surface 19.
• the sectional line between 19 and 20 is in the form of a straight, horizontal line 19a.
• the lower surface 20 is laterally confined against the clearance surface 11 by two straight obliquely extending and symmetrical on the forward end surface of the insert by two straight downward converging sectional lines 22, 23.
• the greatest width between the obliquely downward converging sectional lines 22, 23 should be equal or smaller than the width between the central mutually plane parallel side faces 5, 6.
• the V-shaped recesses formed on the underside of the insert which are formed by the partial surfaces 2a, 2b, 2c extend along the entire length of the insert.
• the intersection line between surface 20 and the inserts front lower end is given a U-shaped contour.
• the size of the radius of the concave surface 19 should be such that one obtains an angular difference between the surfaces 18 and 19, which lies in the range of 10° - 60°, preferably 30°- 45°.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Drilling Tools (AREA)
• Milling Processes (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20412564

Family Applications (1)

Country Status (9)

Cited By (7)

Families Citing this family (24)

Citations (3)

Family Cites Families (16)

• 1998
  • 1998-09-09 SE SE9803083A patent/SE514872C2/sv not_active IP Right Cessation
• 1999
  • 1999-09-08 KR KR1020017003010A patent/KR100676950B1/ko not_active Expired - Lifetime
  • 1999-09-08 AT AT99968645T patent/ATE260728T1/de not_active IP Right Cessation
  • 1999-09-08 EP EP99968645A patent/EP1112132B1/en not_active Revoked
  • 1999-09-08 WO PCT/SE1999/001565 patent/WO2000013824A1/en not_active Ceased
  • 1999-09-08 JP JP2000568615A patent/JP2002524272A/ja not_active Withdrawn
  • 1999-09-08 CN CN99810469A patent/CN1115219C/zh not_active Expired - Lifetime
  • 1999-09-08 US US09/786,757 patent/US6715968B1/en not_active Expired - Lifetime
  • 1999-09-08 DE DE69915315T patent/DE69915315T2/de not_active Revoked
• 2008
  • 2008-12-16 JP JP2008319439A patent/JP2009056594A/ja active Pending

Patent Citations (3)

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