Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B5/00—Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor
  • B23B5/08—Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor for turning axles, bars, rods, tubes, rolls, i.e. shaft-turning lathes, roll lathes; Centreless turning
  • B23B5/12—Turning-machines or devices specially adapted for particular work; Accessories specially adapted therefor for turning axles, bars, rods, tubes, rolls, i.e. shaft-turning lathes, roll lathes; Centreless turning for peeling bars or tubes by making use of cutting bits arranged around the workpiece
• • 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
  • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
  • B23B27/16—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped
  • B23B27/1614—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped with plate-like cutting inserts of special shape clamped against the walls of the recess in the shank by a clamping member acting upon the wall of a hole in the insert
• • 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
  • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
  • B23B27/16—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped
  • B23B27/1614—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped with plate-like cutting inserts of special shape clamped against the walls of the recess in the shank by a clamping member acting upon the wall of a hole in the insert
  • B23B27/1622—Cutting tools of which the bits or tips or cutting inserts are of special material with exchangeable cutting bits or cutting inserts, e.g. able to be clamped with plate-like cutting inserts of special shape clamped against the walls of the recess in the shank by a clamping member acting upon the wall of a hole in the insert characterised by having a special shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2200/00—Details of cutting inserts
  • B23B2200/04—Overall shape
  • B23B2200/0471—Square
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2200/00—Details of cutting inserts
  • B23B2200/04—Overall shape
  • B23B2200/0471—Square
  • B23B2200/0476—Square rounded
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2220/00—Details of turning, boring or drilling processes
  • B23B2220/40—Peeling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23B—TURNING; BORING
  • B23B2220/00—Details of turning, boring or drilling processes
  • B23B2220/44—Roughing
  • B23B2220/445—Roughing and finishing

Definitions

• Bar-peeling is a machining operation which differs from both a standard turning operation in which the workpiece is rotated and from a standard milling operation in which the cutting tool rotates and the workpiece is static.
• a bar-peeling operation an elongated bar is moved (relatively) in an axial direction through an area where a bar-peeling cutting tool assembly is located, and a peeling head rotates around the bar ‘peeling’ away the outer layer.
• Such operations are characterized as very “rough” machining operations with large chip loads and resulting high forces on the cutting insert and cutting assembly, as well as instability with substantial resultant vibration being typical.
• Fig. 1 of US 5,256,008 shows in a schematic representation of a conventional bar peeling operation useful for understanding.
• US 5,256,008 is directed to a tool assembly for a peeling operation in which the toolholder is provided with a roughing insert with convexly curved cutting edges and a finishing insert with basically linear cutting edges.
• the bar-peeling insert positioned to first contact a workpiece hereinafter alternatively called “bar”
• a roughing bar-peeling insert or for conciseness “roughing insert”
• a finishing bar-peeling insert or for conciseness “finishing insert”.
• DE 2 820 810 discloses an elongated two-edged insert in which each of the edges has what will be called hereinafter a peeling sub-edge and a wiper sub-edge.
• the peeling sub-edge, as well as being inclined at a different angle to the wiper sub-edge, is itself further inclined at two different angles, this being for the stated purpose of reducing the risk of edge breakage.
• the reason given is that a curved shape (the two different angles) is beneficial to prevent breakage but reduces surface finish. It is understood from the disclosure that the use of an elongated insert allows also a large depth of cut to be made.
• FR 2 483 819 appears to show a convexly curved triangular-shaped insert, and an embodiment in which three such inserts are used together.
• prior art inserts have an elongated shape allowing the increased depth of cut and stabilizing effect described in the prior art publications, or a triangular type shape which is known in the art to be more stable giving the cutting force directions for a bar peeling operation.
• a separate object of the present invention is a new shim.
• cutting inserts are not perfect polygonal shapes, and that the words, “square-shaped” means that a square is the closest regular shape (alternatively “basic square-shaped”, “near-square-shaped” could be used). This is in similarity with prior art inserts described as pentagonal, hexagonal, triangular or trigon, etc.
• the present invention is directed to providing a more versatile bar-peeling insert than is known hitherto.
• a square-shaped bar-peeling insert comprising a cutting edge; the cutting edge comprising: a straight wiper sub-edge and at least partially curved first and second peeling sub edges respectively located on opposing sides of the wiper sub-edges and connecting the wiper sub-edge to an adjacent corner.
• first and second peeling sub-edges are mirror symmetric about the center of the wiper-sub-edge
• a first reason is that the wiper sub-edge is conventionally significantly elongated from the peeling sub-edge to the end, or basically the end, of the bar-peeling insert. This is because bar-peeling is an extremely rough machining operation and said wiper sub-edge not only provides a wiper function but also a stabilizing function, as noted above in the explanation of US 7,972,092. So called wiper sub-edges of other machining applications are typically relatively far small (e.g. 1mm) because their entire function is to produce finish and not to stabilize, which differs from bar-peeling inserts in which the wiper sub-edge is typically significantly longer than even the so-called “peeling sub-edge”.
• a second reason that the wiper sub-edge is elongated is to allow greater depth of cut as noted above in reference to the explanation of DE 2 820 810.
• the loss of the stabilizing length is notable particularly because the bar peeling insert here is square-shaped and not elongated as per some of the prior art inserts, making the loss of length of the wiper sub-edge more notable.
• the bar peeling insert be relatively large for a cutting insert.
• an inscribed circle IC of the bar peeling insert have a diameter D fulfilling the condition: D > 30mm, more preferably D > 35mm.
• such bar-peeling inserts are typically made of relatively expensive cemented carbide and large inserts are more difficult to press, hence it is preferred that they not be made larger than needed.
• the inserts fulfill the condition: D ⁇ 45mm, more preferably D ⁇ 40mm.
• a separate significant advantage relating to versatility is that the same peeling insert can also be used as the roughing bar-peeling insert in which the entire cutting edge along one side thereof, including even the second peeling sub-edge, is utilized (see Fig. 5B).
• each of the first, second, third and fourth peripheral sub-surfaces is associated with a wiper sub-edge which defines said imaginary square and each of the first, second, third and fourth corners are located spaced inwardly from the imaginary square.
• Corners spaced inwardly as described are typically considered disadvantageous for cutting inserts which normally have significant radiused or round corners to increase tool-life. It will be understood that sharper corners are more prone to breakage. However, for the given application of bar-peeling, a sharp corner or as defined above an inwardly spaced corner allows more of the cutting edge to be utilized. Notably, unlike other machining operations the corner of a bar-peeling insert is not intended to machine a workpiece.
• corners being “located spaced inwardly from the imaginary square” could be that the corners are, in a plan view of the first rake surface, sharp-edged corners (i.e. as opposed to round-edged corners). The same is applicable for preferred embodiments with a cutting edge along the second surface.
• US 2019/0054542 discloses a bar-peeling insert with even more edges
• the present invention is thought advantageous at least for the longer wiper (and stabilizing) sub-edge and overall machining depth length along one side of the insert as shown in the roughing bar-peeling insert in Fig. 5B.
• the second rake surface can be identical to the first rake surface, but at the very least comprises a cutting edge configured for a bar-peeling operation to be formed on a second surface located opposite the rake surface.
• the second cutting edge can comprise the same features as the first cutting edge.
• second surface in the specification and claims refer to a second “rake” surface (even if the name “second surface” remains for ease of readability) after it is indicated that such surface is a rake surface (e.g. formed with a cutting edge extending along the intersection thereof with the insert peripheral surface).
• all cutting edges be located adjacent to a chip-former arrangement, such as a groove (certainly for embodiments where the cutting insert itself is a negative insert and a positive edge is needed for compensation).
• a double-sided insert can double the number of cutting edges. Meaning that if along a single side of the square-shaped insert there are two peeling sub-edges, consequently there can eight peeling sub-edges on each rake surface.
• a square-shaped bar-peeling insert comprising: a first rake surface and a second rake surface located opposite thereto; an insert peripheral surface connecting the first rake surface and second surface; and a first cutting edge extending along an intersection of the insert peripheral surface and the first rake surface; the insert peripheral surface comprising first, second, third and fourth peripheral sub-surfaces and first, second, third and fourth corners connecting the first, second, third and fourth peripheral sub-surfaces; wherein, in a plan view of the first rake surface, between each adjacent pair of the each of the first, second, third and fourth corners, the first cutting edge comprises: a straight wiper sub-edge defining
• the second surface can preferably be a rake surface comprising a cutting edge (also called below a “second cutting edge”) along the intersection thereof with the insert peripheral surface.
• a chip forming groove or construction can preferably extend adjacent the cutting edge.
• each of the first, second, third and fourth corners are preferably located spaced inwardly from the imaginary square.
• the insert peripheral surface preferably extends perpendicular relative to both the first rake surface and second surface.
• a peeling sub-edge comprises a primary sub-edge connected to said wiper sub-edge and a secondary sub-edge connected at one side thereof to the primary sub-edge and at the other side thereof to said corner; wherein, in a plan view of the rake surface on which the peeling sub-edges is located, the primary sub-edge is more curved than the secondary sub-edge.
• each of the first and second peeling sub-edges of the bar-peeling insert comprise said primary sub-edge and said secondary sub-edges, in which each respective primary sub-edge is more curved than the adjacent secondary sub-edge.
• the secondary sub-edge is straight.
• the length of one of the sides of the imaginary square defines an insert side-length SL
• the length of each wiper sub edge in the same view defines a wiper length WL
• the insert fulfills the following condition: WL/SL ⁇ 0.6, more preferably WL/SL ⁇ 0.5, and most preferably WL/SL ⁇ 0.45. Nonetheless it is believed advantageous for the wiper length WL not to be overly small so as to not provide a beneficial finish/stabilizing effect.
• the insert fulfills the following condition: WL/SL > 0.20, more preferably WL/SL > 0.30 and most preferably WL/SL > 0.35.
• each corner has a corner radius smaller than any of said first and second peeling sub edges. Since the primary sub-edge has a smaller radius than the secondary sub-edge, preferably each corner has a corner radius smaller than any of said primary sub-edges.
• the length of one of the sides of the imaginary square defines an insert side-length SL
• the length of each peeling sub-edge in a parallel direction to an adjacent one of the sides of the imaginary square defines a peeling length PL
• the insert fulfills the following condition: PL/SL ⁇ 0.3, more preferably PL/SL ⁇ 0.25.
• the peeling sub-edge is functional and preferably should not be overly small. Accordingly, it is preferable for the insert to fulfill the following condition: PL/SL > 0.10, more preferably PL/SL > 0.15.
• At least one, and more preferably both, of the first cutting edge and second cutting edge is 90° rotationally symmetric about an insert axis extending through the centers of both the first rake surface and the second surface.
• the secondary sub-edge is straight in a plan view of the rake surface of the bar-peeling insert. This can allow a relatively small, but not overly small, lead angle.
• a primary sub-edge’s length, primary length P1L be longer than a secondary sub-edge’s length, secondary length P2L.
• a bar-peeling insert-holder comprising: a shank portion and a cutting portion; the cutting portion comprising first and second insert pockets opening out in the same direction; each of the first and second insert pockets comprising a pocket base surface and first and second pocket side surfaces extending from the pocket base surface; wherein, in a plan view of each respective pocket base surface: the first and second pocket side surfaces define two sides of an imaginary square; and the imaginary square of said each pocket base surface is rotated relative to the imaginary square of the other pocket base surface.
• the versatile design of the bar-peeling insert allows it to be used as both a roughing bar-peeling insert or a finishing bar-peeling insert.
• FR 2 483 819 appears to show an embodiment in which identical inserts are used together, the lack of a significant wiper sub-edge seems to be the cause for the need to use three insert pockets instead of only two in the present aspect. And even with three inserts it is believed the wiper sub-edges of the present invention will provide a better finish, as well as other advantages (such as the comparatively long cutting edge, and additional edges per insert).
• the insert pockets can have a corresponding shape.
• the first and second pocket side surfaces of each of the respective first and second insert pockets extend along adjacent sides of the imaginary square.
• the first insert pocket i.e. the insert pocket intended to hold the roughing bar-peeling insert
• said third pocket side surface is not used to abut the bar-peeling insert and hence has only been added for protecting the bar-peeling insert from damage. It is however conceivable that a different abutment arrangement could be utilized in which the bar-peeling insert abuts the third pocket side surface.
• one of the first and second pocket side surfaces of the second insert pocket is parallel with an elongation direction of the insert-holder.
• a shim can be used to protect an insert-holder from being damaged when a bar-peeling insert breaks.
• the shim is made of a harder material than the insert-holder, typically cemented carbide.
• both of the first and second insert pockets are surrounded at least one of the pocket base surfaces is formed with a centrally located screw hole and two shim-screw-holes spaced apart from the centrally located screw hole.
• an insert-holder comprising an insert pocket having a pocket base surface formed with a centrally located screw hole and two shim-screw-holes spaced apart from the centrally located screw hole.
• the bar-peeling tool assembly can also preferably comprise a shim according to the eighth aspect.
• the second insert is orientated such that the first peeling sub-edge thereof, which is located closer than the second peeling sub-edge thereof to the first insert, is positioned to contact the bar workpiece.
• the second insert is orientated such that the second peeling sub-edge thereof, is positioned to not contact the bar workpiece.
• Fig. 1 is a perspective view of a tool assembly according to an inventive aspect the present invention
• Fig. 2A is a perspective view of a shim according to a separately inventive aspect of the present invention, and which is also used in the tool assembly of Fig. 1;
• Fig. 2B is a plan view of the shim in Fig. 2A;
• Fig. 3A is a perspective view of a bar-peeling insert according to an inventive aspect the present invention, and which is also used in the tool assembly of Fig. 1;
• Fig. 3C is a side view of the insert in Fig. 3 A;
• Fig. 4A is a perspective view of a portion of an insert-holder according to an inventive aspect the present invention, and which is also used in the tool assembly of Fig. 1, imaginary hatch-lines are used to show intended abutment regions;
• Fig. 4B is a plan view of the portion of the insert-holder in Fig. 4A and imaginary dashed- squares;
• Fig. 4C is a side view of the insert in Fig. 4A;
• Fig. 5B is a near-plan view (i.e. slightly non-perpendicular to the insert-holder top surface as will be explained below) of a portion of the assembly in Fig. 5A, shown schematically carrying out a bar-peeling operation on a bar workpiece.
• the insert peripheral surface 46 can be considered to comprise first, second, third and fourth peripheral sub-surfaces 48, 50, 52, 54 and first, second, third and fourth corners 56, 58, 60, 62 connecting the first, second, third and fourth peripheral sub-surfaces 48, 50, 52, 54.
• a first cutting edge 66 extends along an intersection of the insert peripheral surface 46 and the first rake surface 42. In this preferred example the first cutting edge 66 extends along the entire insert peripheral surface 46.
• the diameter D is also equal in length to an insert side-length SL length of the imaginary square S.
• the secondary length P2L in this preferred example is about 2mm.
• the cutting portion 94 will be described in more detail.
• the cutting portion 94 comprises first and second insert pockets 22, 24 opening out in the same direction.
• the first insert pocket 22 further comprises a third pocket side surface 114 which in this non-limiting embodiment is intended not to contact the roughing insert 14.
• the roughing insert 14 only contacts the pocket base surface 96 (or more precisely, in this embodiment which comprises shims, the first shim 18 which in turn contacts the pocket base surface 96) and only the first, second and third pocket abutment surfaces 102, 108, 110.
• a different abutment arrangement could conceivably include an abutment surface on the third pocket side surface 114.
• the second insert pocket 24 comprises a pocket base surface 116, circumferentially adjacent first and second pocket side surfaces 118, 120 which define two sides of a second imaginary square S2.
• the pocket base surface 116 of the second insert pocket 24 and the pocket base surface 96 of the first insert pocket 22 face in the same direction.
• the angular orientation of the first pocket 22 differs from the angular orientation of the second pocket 24. Therefore, the imaginary squares SI, S2 of the two pockets 22, 24, respectively, are rotated relative to each other in said plan view, such rotation being around a center of a corresponding imaginary square SI or S2.
• All of the pocket abutment surfaces (shown with schematic hatching in Fig. 4A) of the second insert pocket 24 are formed on the first and second pocket side surfaces 118, 120.
• the first pocket side surface 118 comprises a first pocket abutment surface 122.
• the second pocket side surface 120 comprises a second pocket abutment surface 124 and a third pocket abutment surface 126 which are separated by a relief recess 128.
• the pocket base surface 96 of the first insert pocket 22 is formed with a centrally located threaded screw -hole 130 and two threaded shim-screw- holes 132, 134 spaced apart from the centrally located screw -hole 130 (with a corresponding construction formed in the second insert pocket 24).

Landscapes

• Mechanical Engineering (AREA)
• Engineering & Computer Science (AREA)
• Milling Processes (AREA)
• Turning (AREA)
• Hand Tools For Fitting Together And Separating, Or Other Hand Tools (AREA)
• Packaging Of Annular Or Rod-Shaped Articles, Wearing Apparel, Cassettes, Or The Like (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Control And Other Processes For Unpacking Of Materials (AREA)
• Polishing Bodies And Polishing Tools (AREA)
• Devices For Warming Or Keeping Food Or Tableware Hot (AREA)
• Knives (AREA)
• Food-Manufacturing Devices (AREA)
• A Measuring Device Byusing Mechanical Method (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=74626045

Family Applications (1)

Country Status (10)

Cited By (1)

Families Citing this family (2)

Citations (10)

Family Cites Families (30)

• 2020
  • 2020-11-27 TW TW109141700A patent/TW202130433A/zh unknown
  • 2020-12-01 US US17/108,248 patent/US11833593B2/en active Active
• 2021
  • 2021-01-26 CA CA3163967A patent/CA3163967A1/en active Pending
  • 2021-01-26 JP JP2022539732A patent/JP7629462B2/ja active Active
  • 2021-01-26 BR BR112022013121A patent/BR112022013121A2/pt not_active IP Right Cessation
  • 2021-01-26 WO PCT/IL2021/050084 patent/WO2021161301A1/en not_active Ceased
  • 2021-01-26 KR KR1020227027203A patent/KR20220130718A/ko active Pending
  • 2021-01-26 EP EP21705626.6A patent/EP4103345A1/en active Pending
  • 2021-01-26 IL IL294579A patent/IL294579B2/en unknown
  • 2021-01-26 CN CN202180014384.0A patent/CN115038537B/zh active Active

Patent Citations (10)

Also Published As

Similar Documents

Legal Events