CUTTING TOOLS AND CUTTING INSERTS INCLUDING INTERNAL COOLING
A cutting tool comprises a cutting insert, a tool holder, and a fastener. The cutting insert comprises a cutting edge and a fastener bore adapted to accept a fastener for fastening together the cutting tool and tool holder. A coolant flow recess in the fastener bore is adapted to direct coolant though the coolant flow recess and toward a head portion of the fastener. The tool holder comprises an insert pocket adapted to removably fasten the cutting insert and fastener to the tool holder, and a coolant bore adapted to direct the coolant from the tool holder to the coolant flow recess of the fastener bore. The head portion of the fastener and the coolant flow recess of the fastener bore define a gap that directs the coolant to the cutting edge of the cutting insert.
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This application is a continuation application claiming priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 12/900,544, entitled CUTTING TOOLS AND CUTTING INSTRUMENTS INCLUDING INTERNAL COOLING, filed on Oct. 8, 2010, the entire disclosure of which is hereby incorporated by reference herein.
BACKGROUND OF THE TECHNOLOGY1. Field of the Technology
The present disclosure relates to cutting tools and cutting inserts for machining metallic materials.
2. Description of the Background of the Technology
As used herein, the term “metal cutting” broadly refers to machining, turning, milling, drilling, boring, planing, shaping, reaming, and like material removal operations performed on metallic (i.e., metal and metal alloy) materials. Cutting tools used in metal cutting typically are subjected to high loads and high temperatures. During metal cutting, the cutting tool applies a high load to the metallic workpiece to deform the workpiece. Because of the relative motion of the workpiece and the cutting edge of the cutting tool, shear deformation is produced in the metallic workpiece, generating metal chips from the workpiece. A cutting tool tip or cutting insert will generally include a rake face, which is a portion of the tip or insert that encounters and further deforms chips after the chips are formed at the cutting edge of the tip or insert. Cutting inserts may also include additional features that control chip size and shape. The chips produced in metal cutting are hot from deformation and frictional forces and are in close contact for a time with the cutting tip or cutting insert.
Because cutting inserts experience high loads and frictional contact with the workpiece and the machined chips, the cutting insert, and particularly the insert's cutting edge, is heated to very high temperatures. For example, cemented carbide cutting inserts may be heated to temperatures greater than 1,800° F. (982° C.) during cutting of hard steels. High cutting insert temperatures increase wear during metal cutting and, thus, reduce cutting insert service life. Machine tool operators can reduce tool speed to at least partially counteract high temperature-induced cutting insert wear. Reducing tool speed, however, may adversely affect the finish quality of machined surfaces produced on a metallic workpiece. Instead, a coolant is typically used to cool the cutting edge of a cutting insert during metal cutting.
Metal cutting coolants, which are also referred to as cutting fluids, serve to lubricate the workpiece and reduce frictional forces at low cutting speeds. At higher cutting speeds, coolants predominantly act to cool the workpiece and the cutting insert, and assist in flushing chips away from the cutting insert. The use of coolants in metal cutting significantly increases cutting insert service life, reduces unintended deformation of the workpiece, improves surface finish quality, and enhances chip removal and handling.
Traditionally, coolants are fed from an external source to the region of the interface between the cutting edge of a cutting insert and the workpiece. For example, a flow of coolant may be flooded onto both the workpiece and cutting insert through tubing from an external coolant source. Another method of applying coolant to the cutting edge/workpiece interface region is to direct a jet of coolant at the interface region. Still another method of applying coolant involves misting a coolant with an air jet and directing the mist at the cutting edge/workpiece interface region.
Conventional methods of applying coolants to a cutting edge/workpiece interface region are inefficient. For example, an excess amount of expensive coolant typically is applied during metal cutting to better ensure that coolant will contact the interface region and remove heat from the cutting insert's cutting edge. However, although excess coolant is applied, because of the tight tolerances at the interface region and the continuous generation of chips at the interface, less than an optimal amount of coolant is delivered to the interface region to efficiently and effectively reduce the temperature of the cutting insert's cutting edge. As such, the operating temperature of the cutting insert's cutting edge may remain very high, reducing cutting insert service life.
Accordingly, a need exists for an improved arrangement for reducing the temperature of the cutting edge of a metal cutting insert during cutting operations. In particular, a need exists for an improved system to deliver coolant to the cutting edge/workpiece interface during cutting operations.
SUMMARYAn aspect according to the present disclosure is directed to a cutting insert comprising at least one cutting edge and at least one fastener bore adapted to accept a fastener for removably securing the cutting insert to a tool holder. The fastener bore includes at least one coolant flow recess adapted to direct a coolant though the coolant flow recess and toward the at least one cutting edge when the cutting insert is secured to the tool holder by a fastener.
An additional aspect according to the present disclosure is directed to a cutting tool comprising a cutting insert, a tool holder, and a fastener. The cutting insert comprises at least one cutting edge and at least one fastener bore adapted to accept a fastener for removably securing the cutting insert to the tool holder. The at least one fastener bore includes at least one coolant flow recess adapted to direct a coolant though the coolant flow recess and toward a head portion of the fastener when the cutting insert is secured to the tool holder by the fastener. The tool holder comprises at least one insert pocket adapted to accept the cutting insert and allow the cutting insert to be secured to the tool holder by the fastener. The tool holder further comprises at least one coolant bore adapted to direct coolant from the tool holder to the at least one coolant flow recess of the fastener bore. The head portion of the fastener and the coolant flow recess of the fastener bore define a gap that directs coolant toward the cutting edge of the cutting insert.
An additional aspect according to the present disclosure is directed to a cutting insert including an internal coolant system, wherein the cutting insert comprises at least one cutting edge, at least one fastener bore adapted to accept a fastener for removably fastening the cutting insert to a tool holder, and at least one through cavity positioned adjacent to the fastener bore. The at least one through cavity extends from a top face of the cutting insert to a bottom face of the cutting insert and is adapted to direct a coolant fluid though the cutting insert and toward the at least one cutting edge when the cutting insert is fastened to a tool holder by a fastener.
Yet an additional aspect according to the present disclosure is directed to a cutting tool comprising a cutting insert, a tool holder, and a fastener. The cutting insert comprises at least one cutting edge, at least one fastener bore adapted to accept a fastener for removably fastening the cutting insert to the tool holder, and at least one through cavity adapted to direct a coolant though the cutting insert and toward a head portion of the fastener when the cutting insert is fastened to the tool holder by the fastener. The tool holder comprises at least one coolant bore adapted to direct a coolant from the tool holder to the at least one through cavity of the cutting insert. The head portion of the fastener and the at least one through cavity of the cutting insert define a gap that directs coolant to the at least one cutting edge of the cutting insert.
The features and advantages of methods described herein may be better understood by reference to the accompanying drawings in which:
The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of certain non-limiting embodiments of cutting tools, tool holders, and cutting inserts according to the present disclosure.
DETAILED DESCRIPTION OF CERTAIN NON-LIMITING EMBODIMENTSIn the present description of non-limiting embodiments, other than in the operating examples or where otherwise indicated, all numbers expressing quantities or characteristics are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, any numerical parameters set forth in the following description are approximations that may vary depending on the desired properties one seeks to obtain in the cutting tools, tool holders, and cutting inserts according to the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Any patent, publication, or other disclosure material that is said to be incorporated, in whole or in part, by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in the present disclosure. As such, and to the extent necessary, the disclosure as set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
A non-limiting aspect according to the present disclosure is directed to an improved cutting insert that is adapted to internally channel, divert, and/or direct a coolant (i.e., a cutting fluid) through the cutting insert and toward a cutting edge of the cutting insert. By internally directing coolant to the cutting edge, the ability to remove heat from the cutting edge is improved. The improvement in removing heat from the cutting edge made possible by the present invention reduces the quantity of coolant needed during metal cutting, may allow for increased cutting speeds, reduces frictional heating, and increases the service life of cutting inserts.
As can be seen from
The coolant flow recesses 11 may be formed by cutting or otherwise removing material from the original wall or surface 23 of the fastener bore 12. Alternatively, the coolant flow recesses 11 may be built into the tooling dies and created when the cutting insert 10 is pressed in a mold or extruded in an injection machine. The coolant flow recesses 11 extend from the top face 21 of the cutting insert 10 to the bottom face 22 of the cutting insert 10. The fastener 13 is in physical contact with the cutting insert 10 at the remaining regions of the fastener bore surface 23 and secures the cutting insert 10 to the tool holder 15. In non-limiting embodiments, the cutting insert 10 includes a chamfer 24 (see detail portion of
As shown in
The peripheral gap 29 may be specifically shaped to account for the type and configuration of the cutting insert 10. For example, the bottom face 26 of the head portion 19 may be parallel to a flat plateau 27 on the top face 21 of a cutting insert. Such a design is advantageous if the cutting edge of the cutting insert and the top edge of the fastener bore are at about the same level (when the cutting insert is in an orientation as shown in
As described hereinabove and shown in
In the non-limiting embodiment of a cutting insert depicted as cutting insert 10 in
Optionally, the cutting insert 10, along with other embodiments of cutting inserts according to the present disclosure, may comprise one or more rake faces and chip control features, and any other cutting insert features known to a person having ordinary skill in the art. Such features are conventional and are known to those having ordinary skill in the art. Thus, they are not further discussed herein.
Cutting insert 10 may be made from any material suitable for the cutting operations for which the insert 10 is intended. In certain non-limiting embodiments, the cutting insert 10, along with other embodiments of cutting inserts according to the present disclosure, is manufactured from one or more materials selected from high speed steel, cobalt alloys, cemented carbides, cermets, ceramics, diamond, and polycrystalline diamond. In various embodiments of cutting inserts according to the present disclosure, the cutting inserts comprise any material known to a person skilled in the art that is used now or hereinafter for the manufacture of cutting inserts.
In certain non-limiting embodiments, the cutting insert 10, along with other embodiments of cutting inserts according to the present disclosure, comprises a wear coating, which may be a wear coating composed of single or multiple layers. Examples of non-limiting embodiments of possible wear coatings include one or more of titanium nitride, titanium carbide, aluminum oxide, silicon nitride, and zirconium oxide. In various embodiments of cutting inserts according to the present disclosure, the cutting inserts include coatings of any suitable materials known to a person skilled in the art that is used now or hereinafter for wear coatings on cutting inserts.
According to a non-limiting aspect of the present disclosure, a cutting tool including an internal coolant system comprises: a cutting insert including at least one internal coolant flow recess adapted to channel, divert, and/or direct a coolant (i.e., a cutting fluid) toward at least one active cutting edge of the cutting insert; a tool body adapted to pass coolant through the tool body and into at least one of the internal coolant flow recesses of the cutting insert, and then on to or towards at least one active cutting edge of the cutting insert. By internally directing coolant to the cutting edge, smaller quantities of coolant are required for metal cutting, cutting speeds may be increased, and frictional heating is reduced, resulting in longer cutting insert life.
Further, as shown in
Fasteners, according to certain non-limiting embodiments of this enclosure, may be selected from screws, bolts, clamps, pins, rivets, and any other fasteners known now or heretofore to a person skilled in the art suitable for securing a cutting insert to a tool holder. Possible materials of construction for fasteners include, for example, steels, stainless steels, titanium alloys, and any other materials known now or heretofore by a person skilled in the art to have suitable mechanical properties and corrosion resistance for use in securing a cutting insert to a tool holder. In addition, the fastener must have a configuration and must comprise one or more materials suitable for directing coolant (which may have corrosive properties) toward the cutting edge in action of a cutting insert.
The present disclosure has been written with reference to various exemplary, illustrative, and non-limiting embodiments. However, it will be recognized by persons having ordinary skill in the art that various substitutions, modifications, or combinations of any of the disclosed embodiments (or portions thereof) may be made without departing from the scope of the invention as defined solely by the claims. Thus, it is contemplated and understood that the present disclosure embraces additional embodiments not expressly set forth herein. Such embodiments may be obtained, for example, by combining and/or modifying any of the disclosed steps, ingredients, constituents, components, elements, features, aspects, and the like, of the embodiments described herein. Thus, the present disclosure is not limited by the description of the various exemplary, illustrative, and non-limiting embodiments, but rather solely by the claims. In this manner, it will be understood that the claims may be amended during prosecution of the present patent application to add features to the claimed invention as variously described herein.
Claims
1. A cutting tool comprising:
- a tool holder comprising a coolant port adapted to fluidly communicate with a coolant source;
- a cutting insert comprising a cutting edge and a fastener bore extending through the cutting insert; and
- a fastener comprising a shaft portion adapted to extend through the fastener bore to fasten the cutting insert to the tool holder, and a groove extending along the shaft portion, wherein the groove forms a portion of a coolant flow channel, and wherein the coolant flow channel is adapted to direct coolant from the coolant port, along the coolant flow channel and through the fastener bore, and toward the cutting edge.
2. The cutting tool of claim 1, wherein the cutting insert forms a portion of the coolant flow channel.
3. The cutting tool of claim 1, wherein the fastener further comprises a head portion positioned outside the fastener bore.
4. The cutting tool of claim 3, wherein the head portion further comprises a guide face, and wherein the guide face is angularly oriented toward the cutting edge.
5. The cutting tool of claim 1, wherein the fastener bore comprises a cylindrical passage.
6. The cutting tool of claim 5, wherein the cylindrical passage comprises an inner circumference and the shaft portion comprises an outer circumference, wherein the groove extends radially inward on the shaft portion from the outer circumference, and wherein the outer circumference and the inner circumference form a seal adjacent to the groove.
7. A cutting insert assembly for use with a tool holder, wherein the cutting insert assembly comprises:
- an insert body comprising: a cutting edge; and a fastener bore extending through the insert body; and
- a fastener positioned at least partially through the fastener bore and adapted to fasten the insert body relative to the tool holder, wherein the fastener comprises an recess adapted to direct coolant along the fastener bore and toward the cutting edge.
8. The cutting insert assembly of claim 7, wherein the fastener further comprises a coolant flow guide.
9. The cutting insert assembly of claim 7, wherein the fastener bore comprises an inner perimeter, wherein the fastener comprises an outer perimeter, and wherein the recess extends radially inward from the outer perimeter.
10. The cutting insert assembly of claim 9, wherein regions of the inner perimeter abut the outer perimeter.
11. A cutting tool, comprising:
- a holder comprising a coolant port adapted to fluidly communicate with a coolant source;
- a cutting insert comprising a fastener bore; and
- a fastener, wherein at least a portion of the fastener extends through the fastener bore and comprises a coolant channel adapted to channel coolant from the coolant port through the cutting insert.
12. The cutting tool of claim 11, wherein the coolant channel comprises a recess extending radially inward from an outer perimeter of the fastener.
13. The cutting tool of claim 12, wherein the outer perimeter abuts the cutting insert adjacent to the coolant channel.
14. The cutting tool of claim 11, wherein the fastener further comprises a coolant guide adapted to direct coolant toward a cutting edge of the cutting insert.
15. The cutting tool of claim 14, wherein the fastener further comprises a head, and wherein the coolant guide comprises an angled face of the head.
16. The cutting tool of claim 11, wherein the fastener bore comprises a cylindrical bore through the cutting insert.
17. The cutting tool of claim 11, wherein the fastener bore defines a uniform diameter.
18. A cutting insert assembly for use with a tool holder, the cutting insert assembly comprising:
- a cutting insert body comprising: a cutting edge; and a fastener bore extending through the cutting insert body;
- a fastener adapted to fasten the cutting insert body to the tool holder, wherein the fastener comprises a shaft portion positioned at least partially through the fastener bore, and wherein the shaft portion comprises an outer circumference that forms a seal at regions of the outer circumference, between the fastener and the cutting insert body; and
- a coolant flow channel provided along the fastener bore, wherein the coolant flow channel is defined from the outer circumference of the fastener and into the shaft portion, and wherein the coolant flow channel is adapted to direct coolant through the cutting insert body and toward the cutting edge.
19. The cutting insert assembly of claim 18, wherein the fastener further comprises a head portion positioned outside the fastener bore.
20. The cutting insert assembly of claim 19, wherein the head portion comprises a guide face, and wherein the guide face is angularly oriented toward the cutting edge.
21. The cutting insert assembly of claim 18, wherein the insert forms a portion of the coolant flow channel.
22. A cutting tool, comprising:
- a tool holder comprising a coolant port in fluid communication with a coolant source;
- a cutting insert positionable in a plurality of orientations relative to the tool holder, wherein the plurality of orientations comprises a first orientation, and wherein the cutting insert comprises a plurality of cutting edges, wherein the plurality of cutting edges comprises an first cutting edge portion that is positioned to cut a workpiece when the cutting insert is in the first orientation, and a fastener bore through the cutting insert; and
- a fastener adapted to extend through the fastener bore and secure the cutting insert relative to the tool holder
- wherein the cutting tool comprises a plurality of channels, and wherein the plurality of channels comprises a single active channel in fluid communication with the coolant port when the cutting insert is in the first orientation, wherein the active channel is defined intermediate the fastener and the cutting insert, and wherein the active channel is structured to direct coolant from the coolant port toward the first cutting edge portion.
23. The tool of claim 22, wherein the fastener further comprises a head portion positioned outside the fastener bore.
24. The tool of claim 23, wherein the head portion further comprises a guide face, and wherein the guide face is angularly oriented toward the first cutting edge portion when the cutting insert is positioned in the first orientation.
25. The tool of claim 22, wherein the fastener further comprises a coolant flow guide.
26. The tool of claim 25, wherein the coolant flow guide comprises an axial recess.
27. The tool of claim 22, wherein the fastener bore comprises a cylindrical passage, wherein the fastener comprises an outer perimeter, wherein regions of the outer perimeter are positioned against the insert within the cylindrical passage.
28. The tool of claim 27, wherein the active channel extends inwardly from the outer perimeter of the fastener.
Type: Application
Filed: Mar 5, 2013
Publication Date: Jul 18, 2013
Applicant: TDY INDUSTRIES, LLC (Pittsburgh, PA)
Inventor: TDY Industries, LLC (Pittsburgh, PA)
Application Number: 13/785,375
International Classification: B23B 27/10 (20060101);