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US 2019/0160557 A1Published application
Single-sided three-way indexable milling insert having high void volume to material volume ratio and insert mill therefor
AssigneeIscar, Ltd.
InventorsGIL HECHT, Assaf BALLAS
Life of this patent
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Abstract
A single-sided three-way indexable milling insert for 90° shoulder milling operations, includes a positive basic shape, a rake surface, a peripheral surface including side abutment surfaces, a base bearing surface and a screw hole connecting the rake and base bearing surfaces. The insert has three main cutting edges which lie along an imaginary equilateral triangle. A material volume VF of the cutting insert and a void volume VS of the insert's screw hole fulfill the condition VS/VF≥0.30.
Claims21
A single-sided three-way indexable cutting insert having a positive basic shape and comprising:
- a rake surface;
- a base bearing surface located opposite the rake surface;
- an insert axis (AI) extending perpendicular to the base bearing surface and through the center of the insert, the insert axis defining:
- an upward direction from the base bearing surface towards the rake surface, a downward direction opposite to the upward direction, and an outward direction perpendicular to the upward and downward directions and extending away from the insert axis;
- a cutting insert height (HI) measurable parallel to the insert axis, from the base bearing surface to a highest point of the rake surface;
- a peripheral surface connecting the rake surface and base bearing surface;
- a cutting edge formed along an intersection of the peripheral surface and the rake surface, the cutting edge defining, in a view parallel to the insert axis (AI), an imaginary edge circumscribed circle (CE) having an edge circumscribed diameter (DE);
- and
- a screw hole opening out to the rake and base bearing surfaces, the screw hole comprising:
- a screw hole bottom at an intersection with the base bearing surface;
- a screw hole top at an intersection with the rake surface;
- a void volume (Vs) calculated as the volume of a void extending from the screw hole bottom to the screw hole top;
- and
- a hole circle (CS) defined, in a view parallel to the insert axis (AI), at an intersection of the rake surface and the screw hole, the hole circle (CS) having a hole diameter (DS);
- the base bearing surface defines, in a bottom view parallel to the insert axis (AI), an imaginary base circumscribed circle (CB) having a base diameter (DB);
- the peripheral surface comprises:
- first, second and third abutment surfaces which, in a bottom view along the insert axis, extend parallel with sides of an imaginary equilateral triangle;
- the cutting edge comprises:
- exactly three main sub-edges, which are the three longest sub-edges of the cutting edge and which, in a top view parallel to the insert axis (AI), each extend along a side of an imaginary equilateral triangle and define an edge inscribed circle (CM) having an edge inscribed diameter (DM);
- wherein:
- the base circumscribed diameter (DB) is smaller than the edge circumscribed diameter (DE);
- and
- a volume ratio VS/VF of the void volume (VS) and a material volume (VF) defined by the amount of material of the cutting insert fulfills the condition:
- VS/VF≥0.30.
21 more elements
A tool holder comprising:
- a rear end;
- a front end;
- a tool periphery extending from the rear end to the front end;
- a rotation axis extending through the center of the tool holder and defining a forward direction extending from the rear end to the front end, a rearward direction opposite to the forward direction, and an outward direction perpendicular to the rotation axis and directed from the rotation axis to the tool periphery;
- a shank portion extending forward of the rear end;
- and
- a cutting portion extending forward of the shank portion to the front end, the cutting portion having a tool diameter (DT) at the front end and exactly two circumferentially spaced flutes extending rearwardly from at an intersection of the front end and the tool periphery;
- each of the flutes comprises a pocket formed at the intersection of the front end and the tool periphery;
- each of the two pockets comprising:
- a seat abutment surface;
- a threaded pocket hole opening out to the seat abutment surface;
- and
- first and second lateral abutment surfaces which are straight and oriented at an acute angle to each other in a plan view of the seat abutment surface;
- each first lateral abutment surface extending in an outward and forward direction;
- each second lateral abutment surface extending in an outward and rearward direction;
- and
- the tool diameter (DT) fulfilling the condition DT<11 mm.
14 more elements
Dependencies are inferred from the claim text.