MXPA98001671A - Tool holder to remove and finish one piece of trab - Google Patents

Abstract

A tool holder (10) for removing material from a workpiece (18) where the workpiece and the tool holder are rotational with respect to each other. The tool holder includes a body (12) having a plurality of cavities (14, 16). A roughing insert (28) is carried in one of the cavities of the body. The roughing insert with a rough edge. The roughing insert is of a first degree. A finishing insert (30) is carried in another of the cavities of the body. The finishing insert has a finishing edge. The finishing insert is of a different degree than the insert of the desbas

Description

TOOL HOLDER TO DRILL AND FINISH ONE PIECE OF WORK BACKGROUND OF THE INVENTION The invention pertains to a tool holder for roughing and finishing a work piece, as well as to a method for using same. More specifically, the invention pertains to a tool holder for roughing and finishing a workpiece, and a method of using same, which provides an acceptable workpiece surface finish after only one step of the relative tool holder. to the work piece. In a typical material removal operation where the workpiece and the cutter insert move and rotate relative to each other, there are three basic components. These components comprise the cutting insert, the tool holder that carries the cutting insert, and the material of the workpiece. Typical material removal operations for which this invention is suitable include turning, threading, drilling, boring and brushing. In some of these types of material removal, the toolholder cuts one or more cutting inserts in such a way that only a single type of cutting insert attacks the workpiece at any given time. Although the specific process varies depending on the material of the workpiece and the desired end result, many machining operations include at least two cuts, or steps relative to, the workpiece. In the first cut (or roughing) generally, a roughing insert attacks the work piece in order to remove a preselected volume of material from said work in order to achieve a desired dimension and a surface finish of the workpiece. After having completed the roughing cut, the roughing insert is either replaced for a finishing insert, or the roughing insert moves out of position and a finishing insert occupies that position, where the finishing insert attacks the surface of the workpiece that has already been machined by the roughing insert in order to machine the work piece to a desired final dimension and a desired finishing surface. While the first arrays of tool holders by which the roughing insert and a finishing insert sequentially attack the work piece thus achieving satisfactory results, some aspects remain to be improved. This is especially the case with respect to the operating efficiencies associated with the first processes in which the roughing insert and the finishing insert sequentially attack the work piece.

% In this regard, it would be desirable to provide a tool holder that carries both a roughing insert and a finishing insert so that the work piece is trimmed and finished in only one cut in contrast with a plurality of cuts. The efficiency of the complete machining process improves in a decrease in the number of cuts needed to produce a workpiece with the appropriate final dimension and the final surface finish also appropriate. BRIEF DESCRIPTION OF THE INVENTION It is an object of the invention to provide a tool holder that carries both a roughing insert and a finishing insert so that the work piece is trimmed and finished in only one cut in contrast with a plurality of cuts. From here, the invention is a tool holder for removing material from a workpiece where the tool holder and the workpiece are rotatable with respect to each other. The toolholder comprises a body having a plurality of cavities where a roughing insert is carried in one of the cavities of the body. The roughing insert has a roughing edge. The roughing insert is of a first degree. A finishing insert is carried in another of the cavities of the body. The finishing insert has a finishing edge. The finishing insert is of a different degree than that of the said roughing insert. In another form, of all this, the invention is a tool holder to remove material from a work piece where the work piece and the tool holder are rotational with respect to each other. The tool holder comprises a body having a plurality of cavities. A roughing insert is carried by the body, the roughing insert has a roughing edge. A finished finish is carried by the body. The finishing insert has a finishing edge. The finishing edge of the insert is sharper than the roughing edge of said roughing insert. In yet another form of all this, the invention is a tool holder for removal of material from a workpiece where the tool holder and the workpiece are rotatable with respect to each other. The tool holder comprises a body having a plurality of cavities. A roughing insert is carried by the body and has a roughing edge. A finishing insert is carried by the body and has a finishing edge. The body includes a front face. The finishing edge of the finishing insert projects a greater distance from the front face of the body than that which exists up to the roughing edge of said roughing insert. In yet another form of all this, the invention is a method of removing material from a workpiece comprising the steps of: providing a tool holder with a face, the face containing a front cavity and a rear cavity; providing a roughing insert being positioned with the front cavity where said roughing insert is of one degree; providing a finishing insert being positioned in the rear cavity where the finishing insert is made of a different degree of the degree of each said roughing insert; moving the workpiece and the tool holder relative to one another so that the roughing insert first attacks the workpiece and then the finishing insert attacks the surface of the workpiece already attacked by the insert. roughing. BRIEF DESCRIPTION OF THE DRAWING The following is a brief description of the drawings forming a part of this patent application: Figure 1 is a side view of a specific embodiment of a workpiece of the invention illustrated in combination with a workpiece work that is rotating around its longitudinal central axis; Figure 2 is a perspective view of the thin film diamond roughing insert of the specific embodiment illustrated in Figure 1; Figure 3 is a top view of the roughing insert of Figure 2; Figure 4 is a side view of the roughing insert of Figure 2; Figure 5 is a perspective view of a finishing insert, which has a tip composed of polycrystalline diamond, of the specific embodiment shown in Figure 1; Figure 6 is a top view of the finishing insert of Figure 5; and Figure 7 is a side view of the finishing insert of Figure 5. DETAILED DESCRIPTION OF A PREFERRED MODALITY Referring to the drawings, Figure 1 represents a specific embodiment of the working tool of the invention, generally designated as 10. Work tool 10 includes a body 12 together with cavities 14 and 16. Figure 1 also illustrates a workpiece, generally designated 18, which rotates about its central longitudinal axis to -A. The work piece 18 presents three surface conditions; otherwise, a machining surface 22, a roughened surface 24, and a finished surface 26.

The pre-machined surface 22 has the surface condition of the work piece prior to the start of any machining operation. The roughened surface 24 is the result of machining of the workpiece 18 by a roughing insert 28. As shown in Fig. 1 the roughing insert 28 is fixed in the cavity 14 of the body 12 of the working tool. The finished surface 26 is the result of machining of the work piece by a finishing insert 30. As shown in Figure 1, the insert 30 is fixed in the cavity 16. The body of the work tool 12 includes two basic parts; that is, a front part 32 and a rear part 36. These parts 32, 36 have a relative movement with respect to each other so that at the moment when the tool holder 10 reaches the end of a cut with the roughing insert. 28, the front part 32 of the tool holder body 12 retracts away from the work piece, with the rear part 36 motionless, in this way the tool holder 10 can continue to move relatively to the work piece thus causing the finishing insert 30 can finish the cut. In the specific embodiment illustrated in the drawings, the roughing insert 28 is of an insert style SPGN-422 ("American National Standard for Cutting Tools - In-dexabble Inserts Identification System"), ANSÍ Standar B212.4-1986 ), which is a two-nosed radio insert. As shown in Figures 2 to 4, the roughing insert 28 includes an upper surface 32, a lower surface 34, and four side surfaces 36, 38, 40 and 42. The joining of the surfaces (36, 38, 40 and 42) form four corners (44, 46, 48 and 50) having a radius "R1". See Figure 4. The side surface (36, 38, 40, 42) are arranged at an angle β (see Figure 4) with respect to a plane perpendicular to the top surface 32 which is equal to 11 degrees. The roughing insert 28 has a thin diamond film on it. The roughing insert 28 is commercially available as a KCD25 insert produced by Kennametal Inc. of Trobe Pennsylvania. The style of the thin diamond film of a roughing insert is the subject of a pending American application with serial number 08 / 159,272 filed on November 30, 1993 entitled "Diamond Coated Tool and Process for Making It". And assigned to the assignee of the present application. The pending American application with serial number 08 / 159,272 filed on November 30, 1993 entitled "Coated Diamond Tool and Process for Making It" is incorporated herein by reference. Due to the nature of the process of applying the thin diamond film to the substrate of the insert, the cutting edges (or rough edges) of the roughing insert 28 is not as sharp as one would wish it to be. This is due to the fact that the substrate is ground prior to the application of the diamond coating. Although the roughing insert of the specific embodiment has a thin diamond film therein it is not intended to limit the scope of the invention to this specific type of roughing insert. Referring to Figures 5 to 7, these drawings illustrate one embodiment of a finishing insert 30. The specific geometry of the finishing insert 30 is a three-nosed radius insert style, and this insert functions in the same manner as the insert finishing 30 in this specific mode. The use of a nose nose three insert does not attempt to limit the scope of the present invention. The finishing insert 30 includes an upper surface 34, a lower surface 56, and four side surfaces 58, 60, 62, and 64. The joining of the adjacent side surfaces form four corners 66, 68, 70 and 72 that have a radius "R2". (See figure 6). As shown in Figure 7, the side surfaces are disposed at an angle "T" with respect to a plane perpendicular to the top surface 54 that is equal to 11 degrees. Referring to figures 5 and 6, the finishing insert 30 has a polycrystalline diamond tip 76 that defines the upper cutting edge (or finishing edge) 77. The use of a polycrystalline diamond tip 76 results in a finishing insert 30 having a very cutting edge. sharp 77. The welded edge 77 of the finishing insert 30 is sharper than the cutting edge of the roughing insert 28. The present disclosure describes a specific embodiment of a toolholder where there are three distinct differences between the roughing insert and the insert. finish. One area of difference lies in the degree of uncertainty in which the finishing insert is of a different degree from that of the roughing insert. A second area of difference lies in the roughness of the surface of the cut edges of the insert in which the cutting edge of the finishing insert is more sharp, and produces a surface finish of the smoothest workpiece, which that of the cutting edge of the roughing insert. A third area of difference lies in the distance of the exposed cutting edge projected from the phase of the front face of the head of the tool holder. More specifically, the cutting edge of the finishing insert projects to a larger distance from the front face than does the cutting edge of the roughing insert. In operation, the workpiece 18 rotates about its longitudinal axis A-A in the direction of the arrow "B". The tool holder 10 then moves in the "C" direction relative to the workpiece. The direction?, C "is generally parallel to the central longitudinal axis AA of the workpiece As can be seen, the first cutting insert attacking the surface of the workpiece is the roughing insert 28. This insert roughing 28 removes material from the workpiece to a specific "D" depth that also results in the portion of the workpiece (rough surface 24) having a specific surface slab. it attacks the roughened surface 24 in a manner to remove material at a depth "E" from the surface roughened to form the finished surface 26. The finished surface 26 is of a specific roughness.The final result of the aforementioned operation, in One step of the tool holder relative to the workpiece produces a finished product having a surface of roughness and specific dimension.It is specifically contemplated that the tool holder of the tool present invention, in addition to the tool that rotates it shown in figure 1, can also be a bore or bar, for example, having at least one roughing insert and at least one finishing insert therein. All documents referred to in this description are hereby incorporated by reference.

Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the description or practice of the invention disclosed herein. It is understood that the description and examples are considered only as illustrative, with the true scope and spirit of the invention being indicated by the following claims.

Claims (20)

1. CLAIMS 1. A tool holder for removing material from a work piece where the tool holder and the work piece are rotating with respect to each other, the tools comprising: a body having a plurality of cavities; a roughing insert being carried in one of the cavities of the body, the roughing insert having a roughing edge, the roughing insert being of a first grade the material; a finishing insert being carried in another of the cavities of the body, the finishing insert having a finishing edge, the finishing insert being of a second material grade different from that of said roughing insert; and where said body is selected from a lathe, drill and bore tool body. The tool holder of claim 1 wherein the roughing edge of the roughing insert projects a first distance from the front face of the tool holder; the finishing edge of the finishing insert projects a second distance from the front face of the tool holder; and the first distance being less than the second distance. The tooling implement of claim 1 wherein the finishing edge of the finishing insert produces a surface finish of the work piece that is smoother than the roughing edge of said roughing insert. The tooling implement of claim 1 wherein said roughing insert comprises a substrate having a diamond film thereon so as to cover the roughing edge of said roughing insert. The tool holder of claim 4 wherein the finishing insert has a portion composed of polycrystalline diamond defining the finishing edge. 6. The tool holder of claim 1 wherein the workpiece rotates relatively to the tool holder. 7. The tool holder of claim 1 wherein the tool holder rotates relatively to the workpiece. 8. The tool holder of claim 1 wherein the toolholder body includes a pair of portions, one of the portions carrying the debris insert, this portion being movable with respect to the other portion. 9. A tool holder for removing material from a work piece where the workpiece and the tool holder are rotational with respect to each other, the tool holder comprising: a body having a plurality of cavities; a roughing insert being carried by the body, the roughing insert having a roughing edge; a finishing insert being carried by the body, the finishing insert having a finishing edge; and the finishing edge of the finishing insert being sharper than the roughing edge of said roughing insert. The tool holder of claim 9 wherein the roughing insert is made of a selected grade of material, and the finishing insert is made of a different material grade with respect to that of the roughing insert. 11. The tool holder of claim 9 wherein the body includes a front face, the finishing edge of the finishing insert projects a greater distance from the front face of the body than that of the rough edge of said roughing insert. 12. A tool holder for removing material from a workpiece where the tool holder and the workpiece are rotational with respect to each other, the tool holder comprising: a body having a plurality of cavities; a roughing insert being carried by the body and presenting a rough edge; a finishing insert being carried by the body and presenting a finishing body; the body includes a front face, the finishing edge of the finishing insert projects a greater distance from the front face of the body than that of the roughing edge of said roughing insert.; and wherein said body is selected from the group formed of a winch, drill and barrel body. The tool holder of claim 12 wherein the roughing insert is made of a selected grade of material, and the finishing insert is made of a different material grade with respect to that of the roughing insert. The tool holder of claim 12 wherein the finishing edge of the finishing insert is sharper than the roughing edge of each said roughing insert. 15. A method of removing material from a workpiece comprising the steps of: providing a tool with a work face, the face containing a front cavity and a back cavity; providing a roughing insert being positioned with the front cavity where said roughing insert is of a material grade; providing a finishing insert being positioned in the rear cavity where the finishing insert is made of a second grade of material different from the degree of each said roughing insert; moving the tool holder and the workpiece relatively relative to each other so that the roughing insert first attacks the workpiece and then the finishing insert attacks the surface of the workpiece already attacked by the insert. roughing; and wherein said method is selected from the group consisting of turning, drilling and boring. The method of claim 15 wherein said roughing insert comprises a substrate with a thin diamond film thereon so as to cover a roughing edge thereon. The method of claim 15 wherein the finishing insert has a polycrystalline diamond composite portion defining a finishing edge. The method of claim 15 wherein said roughing insert has a roughing edge, the finishing insert has a finishing edge, and the roughing edge of said roughing insert projects a greater distance from the front face of the tool holder than that of the finishing edge that the one of the finishing insert. 19. The method of claim 15 further including the step of retracting the roughing insert away from the workpiece after completion of the workpiece attack by the roughing insert. 20. The method of claim 15 further including the step of rotating the workpiece relatively to the tool holder, and wherein the moving step in- cludes moving the tool holder relative to the work piece by rotating it.