Patent Application
20140255116
The invention pertains generally to a rotary cutting tool (e.g. a drill, a milling cutter, a reamer or similar device) having, for example, a tool shank or tool body and a replaceable or an exchangeable cutting insert made of or including at least one hard cutting material, e.g. a tungsten carbide cutting alloy, oxide ceramic or similar material. More particularly, the invention pertains to a replaceable cutting insert with internal channels formed therein for delivering a coolant material and a related method for making the replaceable cutting insert having internal channels formed therein.
During operation of a rotary cutting tool (e.g. a drilling operation), substantial stresses are exerted on the various tool components. Therefore, the tool should be sufficiently strong and durable. It is known to produce a replaceable cutting insert that can be inserted into the body of the tool. The cutting insert, when sufficiently worn by use in a cutting operation, can be removed and replaced with a new cutting insert. In the particular case of a drill, the cutting insert often contains the entire cutting end of the drill, including the drill tip, the cutting faces, the cutting edges, as well as portions of the chip flutes. Such a cutting insert is connected to the drill body in a secure but removable fashion.
Also during operation of a rotary cutting tool (e.g. a drilling operation), heat is generated at the interface between the cutting insert and the location where material is being removed from a workpiece (i.e., the insert-workpiece interface). It is well-known that excessive heat at the insert-workpiece interface can negatively impact upon the useful tool life of the cutting insert. As can be appreciated, a shorter useful tool life increases operating costs and decreases overall production efficiency. Hence, there are readily apparent advantages connected with decreasing the heat at the insert-workpiece interface. It is known to provide a coolant material to the insert-workpiece interface to decrease the heat and increase the useful tool life.
However, it will be appreciated that most known systems for providing a coolant material to the insert-workpiece interface are difficult and/or expensive to manufacture while still maintaining the overall integrity of the cutting tool components. Thus, it would be desirable to provide an improved rotary cutting tool and, in particular, an improved cutting insert that overcomes limitations, shortcomings and/or disadvantages of known rotary cutting tools and cutting inserts.
In accordance with an aspect of the invention, a replaceable cutting insert includes a cutting insert body having a forward cutting face and an opposing rearward base and an inlet coolant channel formed in the cutting insert body and defining an inlet opening at the rearward base of the cutting insert body, the inlet coolant channel having a longitudinal axis. The replaceable cutting insert also includes a first outlet coolant channel formed in the cutting insert body and in fluid communication with the inlet coolant channel, the first outlet coolant channel defining a first outlet opening at the forward cutting face of the cutting insert body, wherein the first outlet coolant channel includes a first longitudinal axis that is not axially aligned with the longitudinal axis of the inlet coolant channel. The replaceable cutting insert further includes a second outlet coolant channel formed in the cutting insert body and in fluid communication with the inlet coolant channel, the second outlet coolant channel defining a second outlet opening at the forward cutting face of the cutting insert body, wherein the second outlet coolant channel includes a second longitudinal axis that is not axially aligned with the longitudinal axis of the inlet coolant channel.
In accordance with another aspect of the invention, a replaceable cutting insert includes: a cutting insert body having a forward cutting face and an opposing rearward base; a first inlet coolant channel formed in the cutting insert body and defining a first inlet opening at the rearward base of the cutting insert body, the first inlet coolant channel having a first longitudinal axis; a second inlet coolant channel formed in the cutting insert body and defining a second inlet opening at the rearward base of the cutting insert body, the second inlet coolant channel having a second longitudinal axis; a first outlet coolant channel formed in the cutting insert body and in fluid communication with the first inlet coolant channel, the first outlet coolant channel defining a first outlet opening at the forward cutting face of the cutting insert body, wherein the first outlet coolant channel includes a third longitudinal axis that is not axially aligned with the first longitudinal axis of the first inlet coolant channel; and a second outlet coolant channel formed in the cutting insert body and in fluid communication with the second inlet coolant channel, the second outlet coolant channel defining a second outlet opening at the forward cutting face of the cutting insert body, wherein the second outlet coolant channel includes a fourth longitudinal axis that is not axially aligned with the second longitudinal axis of the second inlet coolant channel.
In accordance with another aspect of the invention, a rotary cutting tool includes a tool body having an axial forward end and an axial rearward end, the tool body defining a coolant channel that extends therethrough from the axial rearward end to the axial forward end and a replaceable cutting insert structured and arranged for releasable attachment to the axial forward end of the tool body. The replaceable cutting insert includes a cutting insert body having a forward cutting face and an opposing rearward base positionable adjacent the axial forward end of the tool body, and an inlet coolant channel formed in the cutting insert body and defining an inlet opening at the rearward base of the cutting insert body, the inlet coolant channel having a longitudinal axis, wherein the inlet coolant channel is positionable to be in fluid communication with the coolant channel of the tool body. The replaceable cutting insert also includes a first outlet coolant channel formed in the cutting insert body and in fluid communication with the inlet coolant channel, the first outlet coolant channel defining a first outlet opening at the forward cutting face of the cutting insert body, wherein the first outlet coolant channel includes a first longitudinal axis that is not axially aligned with the longitudinal axis of the inlet coolant channel. The replaceable cutting insert further includes a second outlet coolant channel formed in the cutting insert body and in fluid communication with the inlet coolant channel, the second outlet coolant channel defining a second outlet opening at the forward cutting face of the cutting insert body, wherein the second outlet coolant channel includes a second longitudinal axis that is not axially aligned with the longitudinal axis of the inlet coolant channel
In accordance with yet another aspect of the invention, a method of making a replaceable cutting insert includes forming a hard cutting material mixture, injecting the hard cutting material mixture into a die for forming a replaceable cutting insert body having an inlet coolant channel in fluid communication with a first outlet coolant channel and a second outlet coolant channel, wherein the first outlet coolant channel includes a first longitudinal axis that is not axially aligned with a longitudinal axis of the inlet coolant channel and the second outlet coolant channel includes a second longitudinal axis that is not axially aligned with the longitudinal axis of the inlet coolant channel. The method also includes removing the replaceable cutting insert body from the die. In one aspect, the method further includes configuring the die to include a first linear tooling element for forming the first outlet coolant channel, a second linear tooling element for forming the second outlet coolant channel and a third linear tooling element for forming the inlet coolant channel, wherein the first linear tooling element is interconnected with the third linear tooling element and the second linear tooling element is interconnected with the third linear tooling element. In another aspect, the method includes withdrawing the first and second linear tooling elements before removing the replaceable cutting insert body from the die. In yet another aspect, alternatively the method includes withdrawing the first and second linear tooling elements after removing the replaceable cutting insert body from the die.
These and other aspects of the present invention will be more fully understood following a review of this specification and drawings.
The following description is for purposes of illustrating various aspects of the invention only and not for purposes of limiting the scope of the invention.
Referring generally to
Rotary cutting tool 10 includes a tool body 12, in accordance with an aspect of the invention. The tool body 12 includes an axial rearward end 14 and an axial forward end 16. In the example of the rotary cutting tool 10 being in the form of a drill, the tool body 12 may define one or more flutes 17 formed therein. The tool body 12 also includes a central longitudinal axis A-A which extends therethrough from the axial rearward end 14 to the axial forward end 16. In one aspect, the central longitudinal axis A-A is also a central rotational axis of the rotary cutting tool 10.
As shown in
As shown in
The replaceable cutting insert 24 includes a central longitudinal axis B-B which extends therethrough from the forward cutting face 28 to the opposing rearward base 30. In one aspect, the central longitudinal axis B-B is also a central rotational axis of the replaceable cutting insert 24.
Referring to FIGS. 2 and 4-5, the replaceable cutting insert 24 further includes an inlet coolant channel 34, a first outlet coolant channel 36 and a second outlet coolant channel 38 all formed in the cutting insert body 26, in accordance with an aspect of the invention. The first outlet coolant channel 36 and the second outlet coolant channel 38 are structured and arranged to be in fluid communication with the inlet coolant channel 34. The inlet coolant channel 34 defines an inlet opening 40 at or adjacent the rearward base 40 of the cutting insert body 26. The first outlet coolant channel 36 defines an outlet opening 42 at or adjacent the forward cutting face 28 of the cutting insert body 26. The second outlet coolant channel 38 defines an outlet opening 44 at or adjacent the forward cutting face 28 of the cutting insert body 26.
In one aspect, the inlet coolant channel 34 is located at or adjacent the central longitudinal axis B-B of the replaceable cutting insert 24, although it will be appreciated that the coolant channel 34 may be located at other locations in or throughout the cutting insert body 26. The inlet coolant channel 34 is structured and arranged to be in fluid communication with the coolant channel 18 of the tool body 12. In one aspect, the inlet opening 40 is positionable adjacent the coolant channel outlet 22 of coolant channel 18 so as to be in fluid communication therewith.
Thus, it will be appreciated that the described and illustrated configuration of coolant channel 18, inlet coolant channel 34 and first and second outlet coolant channels 36, 38 provides for a coolant material to pass through the rotary cutting tool 10 and be delivered to the forward cutting face 28 of the replaceable cutting insert 24, i.e. to the insert-workpiece interface to decrease the heat and increase the useful life of the rotary cutting tool 10 and, more particularly, to increase the useful life of the replaceable cutting insert 24.
As illustrated in
In accordance with an aspect of the invention, while the inlet coolant channel 34 is in fluid communication with the first outlet coolant channel 36, the longitudinal axis X-X of the inlet coolant channel 34 is not axially aligned with the longitudinal axis Y-Y of the first outlet coolant channel 36. In another aspect, the inlet coolant channel 34 is linear and the first outlet coolant channel 36 is linear and the inlet coolant channel 34 and the first outlet coolant channel 36 are not axially aligned.
In accordance with an aspect of the invention, while the inlet coolant channel 34 is in fluid communication with the second outlet coolant channel 38, the longitudinal axis X-X of the inlet coolant channel 34 is not axially aligned with the longitudinal axis Z-Z of the second outlet coolant channel 38. In another aspect, the inlet coolant channel 34 is linear and the second outlet coolant channel 38 is linear and the inlet coolant channel 34 and the second outlet coolant channel 38 are not axially aligned.
Still referring to
Yet another aspect of the invention is that the second outlet coolant channel 38 extends at an angle N relative to the inlet coolant channel 34. In other words, the longitudinal axis Z-Z of the second outlet coolant channel 38 extends at the angle N relative to the longitudinal axis X-X of the inlet coolant channel 34. The angle N may be, for example, in the range of about 90 degrees to about 160 degrees.
In another aspect of the invention, the longitudinal axis Y-Y of the first outlet coolant channel 36 is not axially aligned with the longitudinal axis Z-Z of the second outlet coolant channel 38. In another aspect of the invention, the longitudinal axis Y-Y of the first outlet coolant channel 36 is positioned at an angle P relative to the longitudinal axis Z-Z of the second outlet coolant channel 38. The angle P may be, for example, in the range of about 20 degrees to about 180 degrees.
Referring to
Still referring to
In accordance with an aspect of the invention, while the second inlet coolant channel 137 is in fluid communication with the second outlet coolant channel 138, the longitudinal axis X2-X2 of the second inlet coolant channel 137 is not axially aligned with the longitudinal axis Z-Z of the second outlet coolant channel 138. In another aspect, the second inlet coolant channel 137 is linear and the second outlet coolant channel 138 is linear and the second inlet coolant channel 137 and the second outlet coolant channel 138 are not axially aligned.
In another aspect of the invention, the first outlet coolant channel 136 extends at an angle relative to the first inlet coolant channel 134 and the second outlet coolant channel 138 extends at an angle relative to the second inlet coolant channel 137 as similarly described herein regarding replaceable cutting insert 24 and illustrated in
The tool body 12 portion of the rotary cutting tool 10 is made of, for example, steel or any other suitable materials having similar characteristics and properties. The replaceable cutting insert 24 is made of a hard cutting material, e.g. a tungsten carbide cutting alloy, oxide ceramic or any other suitable materials having similar characteristics and properties.
A method of making a replaceable cutting insert such as, for example, the replaceable cutting insert 24, is also provided. In one aspect, the method includes forming a hard cutting material mixture. As described, the replaceable cutting insert can be made of a hard cutting material, e.g. a tungsten carbide cutting alloy, oxide ceramic or any other suitable materials having similar characteristics and properties. In addition to the hard cutting material, a thermoplastics binder, for example, is added to make the mixture. In one aspect, the thermoplastic binder is mixed above its melting temperature with, for example, a carbide powder so that the powder is well dispersed and the mixture flows well at this temperature.
In another aspect, the method includes injecting the hard cutting material mixture into a die for forming a replaceable cutting insert body (e.g. insert body 26) having an inlet coolant channel (e.g. inlet coolant channel 34) in fluid communication with an outlet coolant channel (e.g. first outlet coolant channel 36), wherein the inlet coolant channel includes a longitudinal axis (e.g. axis X-X) that is not axially aligned with a longitudinal axis of the outlet coolant channel (e.g. axis Y-Y). The cutting insert body can also be formed to have an additional or second outlet coolant channel (e.g. second outlet coolant channel 38) wherein the longitudinal axis of the inlet coolant channel is not axially aligned with a longitudinal axis of the additional or second outlet coolant channel (e.g. axis Z-Z).
In order to make the replaceable cutting insert having the described structure, or variations thereof, the method also can include forming, for example, replaceable cutting inserts 24a and/or 24b (schematically represented in
In another aspect, the method includes removing the replaceable cutting insert body and the corresponding linear tooling elements from the die. The removal of the replaceable cutting insert body from the die may be performed in more than one way.
First, referring to
Second, referring to
The third linear tooling elements 50a, 50b can be directly removed (in the direction indicated by arrow H) from the cavity by the die opening action, since these elements, e.g. pins are collinear or in the same general direction with the axis of the die opening, e.g. as represented, for example, by arrow D .
Whereas particular aspects of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.
