JPH0899203A - Insert with polycrystalline cutting edge part capable of free indexing - Google Patents

Abstract

PURPOSE: To display a plurality of side faces for use in cutting operation by partly cutting off a cemented carbide material from at least one of the top and bottom surfaces of an insert at a crossing position of the top or bottom surfaces of the insert with a side wall so as to form a chip breaker. CONSTITUTION: An insert 10 comprises a top surface 12, a bottom surface 14, and a side wall 16 forming a shell part 18 of the insert by surrounding the insert between these top surface 16 and bottom surface 14 substantially without discontinuing. A cutting blade 20 formed of a polycrystalline material is formed by partly grinding or removing the top surface 12 and/or the bottom surface 14 at a position where the side wall 16 is crossed with the top surface 12 or the bottom surface 14 so as to form a chip breaker 22. In the insert 10 the chip breaker 22 extends along the entire peripheral surface of the insert 10 so as to appear a plurality of side faces for use in cutting operation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to indexable cutting inserts of tungsten carbide-polycrystalline material-tungsten carbide. Tungsten carbide is ground to form a chip breaker, which exposes a polycrystalline material for use as a cutting edge. The polycrystalline material may be diamond, cubic boron nitride (cBN) or any other suitable polycrystalline material. The invention further relates to the use of the polycrystalline composite material as a cutting insert without the need for gluing, brazing or otherwise fixing to the insert body.

[0002]

2. Description of the Prior Art U.S. Pat. No. 5,193,948 has a pocket formed at one corner of an insert, to which a wafer of tungsten carbide-polycrystalline material-tungsten carbide is bonded. A cutting insert is described. The upper surface of the wafer forms a ground chip breaker, where the cutting surface of polycrystalline diamond is exposed. This US Pat. No. 5,19
No. 3,948 cutting insert is truly indexable unless a pocket is formed at each corner of the insert body and the wafer is bonded to the pocket thereby providing a polycrystalline cutting edge. I can't say that there is.
Furthermore, forming a large number of pockets and adhering a wafer of polycrystalline material thereto is both expensive and time consuming. Thus, the demand for indexability is not met. US Pat. No. 4,854,784
Control inserts with diamond tips are described,
The control insert incorporates polycrystalline diamond or cubic boron nitride as the cutting edge material, and the insert substrate includes an integrated chip control that eliminates the need for a separate mechanical chip breaker. Be done. The control insert of this U.S. patent differs from that of the present invention in that the control insert first forms a chip breaker and then a slot is cut into the insert body, and finally the slot is filled with polycrystalline material. It is different from the present invention. This arrangement is expensive, labor-intensive, and does not provide the true indexability of cutting edges made of polycrystalline material. U.S. Pat. No. 4,498,549 describes a cutting element for a rotary drill bit consisting of a substrate and a porous material adhered to the substrate. This cutting member, or drill, is not provided with a chip breaker portion and therefore does not use the tungsten carbide-polycrystalline material-tungsten carbide wafer of the present invention. U.S. Pat. No. 4,605,343 describes a sintered polycrystalline diamond compact having an integral metal heat sink adhered to and attached to at least the outer diamond surface. A metal heat sink is used to extend its life when using this sintered polycrystalline diamond compact for material removal without fluid coolant. The present invention does not require a metal heat sink for dry cutting. Further, the present invention not only provides indexability for inserts where the polycrystalline material appears at the cutting edge position of the insert, but also provides a chip breaker. U.S. Pat. No. 4,899,922 describes a brazed, thermally stable polycrystalline diamond compact. This polycrystalline diamond compact has a network in which interconnected hollow pores are dispersed throughout, and is brazed with a filling metal that may be an alloy having a liquid phase at about 700 ° C. or higher. To adhere to the substrate. The use of polycrystalline wafers as indexable metal cutting inserts is not disclosed here.

[0003]

The true realization of indexability is that the chip breaker extends along the entire perimeter of the insert, thereby revealing multiple sides for use in a cutting operation. Is to provide inserts.

[0004]

DISCLOSURE OF THE INVENTION The present invention is an indexable cutting insert made of cemented carbide-polycrystalline material-cemented carbide, the chip breaker-shaped portion of which is formed on one surface. The present invention relates to a cutting insert in which a crystalline material is exposed as a cutting edge of the insert. The insert thus formed is truly indexable and presents the polycrystalline material as a cutting edge along the front circumference of the insert.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings wherein like reference numerals represent like parts, and in particular in FIG.
A bottom surface 14 and a side wall 16 that defines a body portion 18 of the insert that circulates between the top surface 12 and the bottom surface substantially without interruption. Although the insert is shown as polygonal, it may be circular or any other desired shape. For convenience, but not limitation, the sidewall is further formed with a side section, i.e., a sidewall portion extending from one corner to the next in the polygonal insert. If the insert is not polygonal, the side section of the insert is that part of the side wall which is oriented towards the side where it is visible.

The insert may further include diamond or c
Included is a cutting edge 20 formed of a polycrystalline material such as BN or any other suitable polycrystalline material. This cutting edge 20
Is formed by grinding or removing a part of the top surface and / or the bottom surface at a position where the side wall and the top surface or the bottom surface intersect, to form the chip breaker 22. Thus, the inserts of the present invention are truly indexable, with the chip breaker extending along the entire perimeter of the insert, thereby revealing multiple sides for use in a cutting operation. The chip breaker is ground on the top surface and has a concave shape, at least one flank 30 being integral with the chip breaker and close to the cutting edge. Those skilled in the art will recognize that any form of chip breaker can be formed on the top surface to expose a cutting edge of polycrystalline material.

Referring to FIG. 3, there is shown a cross-sectional view of the insert taken along line 3-3 of FIG. 2 to show the structure of the insert barrel. Specifically, this insert body is a composite wafer composed of a wafer made of cemented carbide 24, a polycrystalline material 26 and a cemented carbide layer 28. Such wafers are currently available in sizes large enough for use as insert bodies, typically DRIL.
It is available as a product from Mega Diamond, a branch of Smith International, Inc. in Provo, Utah, under the trademark pax. The polycrystalline material is preferably diamond, but can be cBN or any other suitable polycrystalline material. The cemented carbide portion of the wafer is preferably tungsten carbide, although other cemented carbides may be used. The insert is formed by processing such a composite amount of material to the desired insert thickness and dimensions. After achieving the desired wall thickness,
A chip breaker is machined on the top surface to expose a polycrystalline material for use as a cutting edge. When working,
The insert is clamped or otherwise secured to the tool holder and the work piece is presented in any manner known to those skilled in the art. Cutting edges made of polycrystalline material are particularly suitable for use in cutting highly abrasive materials such as aluminum and high strength steel. Although the present invention has been described above with reference to specific examples, it should be understood that many modifications can be made within the present invention.

[0008]

The insert is provided with true indexability, with the chip breaker extending along the entire perimeter of the insert, thereby revealing multiple sides for use in a cutting operation. It

[Brief description of drawings]

FIG. 1 is a perspective view of an insert of the present invention.

FIG. 2 is a plan view showing the features of the insert of the present invention.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

[Explanation of symbols]

 10 insert 12 upper surface 14 bottom surface 16 sidewall 18 insert body 20 cutting edge 22 chip breaker 30 flank 26 polycrystalline material 28 cemented carbide layer

Claims (5)

[Claims] 1. An indexable cutting insert having a cutting edge made of a polycrystalline material along the entire circumference of the insert, the upper surface and the bottom surface being provided without interruption between the upper surface and the bottom surface. And a side wall formed by extending to form a body portion, the body portion being made of a composite wafer made of a cemented carbide material, a polycrystalline material and a cemented carbide material, and the cutting edge being made of a porous material. A chip breaker is formed behind the cutting edge and the chip breaker partially removes the cemented carbide material from at least one of the top or bottom surface of the insert at the intersection of the top or bottom surface and the side wall. An indexable cutting insert formed by. 2. The indexable cutting insert of claim 1 wherein the cutting edge made of polycrystalline material is selected from the group consisting of polycrystalline diamond, cubic boron nitride, and mixtures thereof. 3. The indexable cutting insert according to claim 1, wherein the cemented carbide material is tungsten carbide. 4. The insert is polygonal in shape.
A cutting insert that can be freely indexed. 5. The indexable cutting insert according to claim 1, wherein the chip breaker is integrated with the chip breaker and has a flank that is close to the cutting edge.