CUTTING INSERT WITH INTERNAL COOLING, MOLD AND METHOD FOR MANUFACTURE THEREOF
20230059599 · 2023-02-23
Inventors
Cpc classification
B23B27/145
PERFORMING OPERATIONS; TRANSPORTING
B23C5/28
PERFORMING OPERATIONS; TRANSPORTING
B23B51/06
PERFORMING OPERATIONS; TRANSPORTING
B30B15/022
PERFORMING OPERATIONS; TRANSPORTING
B23C5/202
PERFORMING OPERATIONS; TRANSPORTING
B23C2210/168
PERFORMING OPERATIONS; TRANSPORTING
B23B2251/50
PERFORMING OPERATIONS; TRANSPORTING
B30B11/02
PERFORMING OPERATIONS; TRANSPORTING
B23B27/10
PERFORMING OPERATIONS; TRANSPORTING
International classification
B23B27/10
PERFORMING OPERATIONS; TRANSPORTING
B23B27/14
PERFORMING OPERATIONS; TRANSPORTING
B23B51/06
PERFORMING OPERATIONS; TRANSPORTING
B23C5/20
PERFORMING OPERATIONS; TRANSPORTING
B23C5/28
PERFORMING OPERATIONS; TRANSPORTING
B30B11/02
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A cutting insert is provided, comprising a top surface, a bottom surface, a plurality of side surfaces spanning therebetween, and a cutting edge formed at an intersection of the side surface and a forwardly-disposed portion of the top the surface. It further comprises a cooling cavity projecting into the insert, a top end thereof being disposed further forwardly than an open bottom end thereof. The cooling cavity defines at least one molding axis such that a solid element having the shape of the cooling cavity and completely inserted therein may be retracted intact therefrom along a linear path parallel to the molding axis. A circumscribing portion is formed on the side surfaces encircling the cutting insert. The circumscribing portion is formed parallel to the molding axis and has a non-zero height along its entire extent. The cutting insert does not extend beyond the circumscribing portion.
Claims
1-15. (canceled)
16. A press-mold for manufacturing a cutting element including a top surface and a bottom surface generally parallel thereto, and a cavity having a characterizing axis, said characterizing axis being angled to the top or bottom surface between 35-65°; said press mold comprising: a male member; and a female member; wherein each of the male and female members have a base surface angled at between 35-65° to a pressing axis of the press-mold, the base surfaces being used to form the top and bottom surface of the cutting element, and at least the male member further having a projection oriented generally along the pressing axis, configured for forming the cavity.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0072] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
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DETAILED DESCRIPTION
[0159] As illustrated in
[0160] As seen in
[0161] The tool holder 20 is further formed with an cooling inlet 26 configured for emitting the cooling fluid provided through the channel 16, and an outlet 28 configured for removal of the cooling fluid from the area of the insert seat space 20.
[0162] As illustrated in
[0163] The base plate 30 further comprises an inlet hole 36 and an outlet hole 38 which, when the base plate 30 is mounted into the insert seat space 20 of the cutting tool holder 10, are aligned with the respective inlet and outlet 26, 28 of the cutting tool holder 10.
[0164] The base plate 30 further comprises a fluid ramp 40 projecting from the top surface 32T thereof, disposed between the inlet 36 and the outlet 38, and configured for directing the flow of the cooling fluid towards a designated area of the cutting insert 50.
[0165] In particular, as shown in
[0166] Attention is now drawn to
[0167] In addition, the cutting insert 50 comprises four cooling cavities 60, each associated with a respective cutting edge 54. Each cooling cavity has an inner space 62 delimited by side walls and a slope 64, tapering away from the cutting edge 54. The inner surface of the cavity provides each cutting corner of the cutting insert 50 with a shell-like geometry (a thin-walled structure) which has an external, operational surface (comprising the cutting edge 54) and an internal, cooling surface constituted by the surface of the cavity 60.
[0168] It is observed that the cooling surface is formed with an array of ribs, including rake ribs 66 which extend generally parallel to the rake surface 56 and relief ribs 68 which extend generally parallel to the relief surface 58. With particular reference to FIG. 5B, the rib array allows the shell-like geometry to be of relatively small thickness t, reaching extremely close to the cutting edge 54. In other words, the arrangement is such that the cavity surface at the cutting zone is much closer to the cutting edge 54 than to the bottom surface 52.sub.B of the cutting insert 50.
[0169] It will be appreciated that a cutting insert 20 may comprise a single rib, which may be a rake rib 66 or relief rib 68 such as described, or a single rib a portion of which is generally parallel to the rake surface 56, and a portion of which is generally parallel to the relief surface 58. The single rib may be disposed centrally within the cavity 60, or off-center.
[0170] Turning to
[0171] It is also noted that the geometry of ribs (as opposed to a straight wall) provides for a much stronger construction, allowing the cavity 60 to be even closer to the cutting edge 54, i.e., provide a smaller thickness between the external, operative surface and internal, cooling surface (as small as 0.5 mm).
[0172] In operation, during cutting of a workpiece (not shown), the cutting edge 54 heats up due to constant friction with the workpiece. This heat, reduction of which is usually facilitated by providing a cooling fluid directly to the cutting edge, propagates towards the center of the cutting insert 50 so that the body 52 of the cutting insert 50 becomes a heat accumulator.
[0173] In order to mitigate this effect, the arrangement according to the subject matter of the present application allows cooling the inner portion of the cutting zone of the cutting insert 50 thereby facilitating both increased cooling of the cutting edge 54 (external cooling is used anyway, though not shown here) and cooling of the body 52 of cutting insert 50 itself.
[0174] With additional reference being made to
[0175] The above described cutting insert 50 is configured for both milling and cutting, or turning, operations. In this regards, the following differences should be noted between these two operations:
[0176] Milling—the cutting edge keeps coming in and out of contact with the workpiece. As a result, when it is in contact with the workpiece the cutting edge heats up, whereas when it is out of contact, the cutting edge cools down. However, this constant motion in and out of the workpiece causes the milling insert to be repeatedly “impacted” by the workpiece, requiring sufficient mechanical robustness and stability;
[0177] Turning—the cutting edge remains within the workpiece throughout the cutting operation, whereby the effect of “impact” by the workpiece, which occurs in milling, is eliminated. However, since the cutting edge is constantly in contact with the workpiece, it constantly heats up, requiring sufficient cooling to prevent mechanical damage to the cutting insert.
[0178] The above described cutting insert 50 provides both for sufficient mechanical integrity to withstand a milling operation as well as sufficient heat removal space for the cooling fluid.
[0179] Turning now to
[0180] Attention is now drawn to
[0181] The only difference between the cutting tool 1′ and cutting tool 1 lies in that the outlets 28′, 38′ of the cutting tool holder 10′ and base plate 30′ respectively, are in the shape of open channels.
[0182] Specifically, the heated cooling fluid emitted from the cavity 60′ of the cutting insert 50′ does not pass through a closed channel as shown in cutting tool 1, but rather through an open channel 38′, 28′ as shown in the above Figs.
[0183] The open channel configuration allows increasing the flow rate of the cooling fluid W by increasing the drainage rate of the cooling fluid.
[0184] Turning now to
[0185] In the present example, the insert seat space 20″ of the cutting tool holder 10″ comprises one inlet 26″ located at the proximity of the working corner and two outlets 28″ located spaced therefrom.
[0186] Respectively, the base plate 30″ comprises an inlet 36″ configured to be aligned with the inlet 26″ and two outlets 38″ spaced therefrom and configured for being aligned with the outlets 28″. Contrary to the previously described example, the base plate 30″ does not comprise a fluid ramp.
[0187] Turning to
[0188] Reverting to
[0189] It is observed that, as opposed to the previously described example, the cutting insert 50″ of the present example comprises much less material, and is therefore less robust. As a result, it may be that the above cutting insert 50″ is more suitable for turning operation rather than milling.
[0190] However, it is noted that the above cutting insert may also be used in milling, in particular, in milling operations in which three corners of the cutting insert 50″ come into contact with the workpiece. In this case, it is appreciated that the cooling fluid W facilitates cooling not only of the main corner towards which the fluid is discharged but also to the adjacent cutting corners due to flow of the cooling fluid towards the discharge outlets 38″.
[0191] Attention is now drawn to
[0192] Reduced corner—the cutting insert 50′″ has a chipped-away portion 59′″ at each corner proximal to the bottom surface 52.sub.B′″, which provides an additional drainage outlet for the cooling fluid during operation, via a formed gap g; and
[0193] Additional holes—the top surface 52.sub.T′″ of the cutting insert 50′″ is provided with four through going drainage holes 57′″ which are configured for facilitating greater removal of cooling fluid from the cutting insert 50′″.
[0194] It is noted that the drainage holes 57′″ are not directed to the cutting corner as they are not intended for providing cooling fluid to the external surface of the cutting edge 54′″. On the contrary—the drainage holes 57′″ are only configured for allowing increased evacuation of cooling fluid from the cutting insert 50′″. Thus, it can be posited that the majority of the cooling fluid emitted from the drainage holes 57′″ does not reach the operative cutting corner at all.
[0195] Turning to
[0196] The male part 130′″ also comprises eight mid-projections 150′″ which are configured for the forming of the ribs disposed along the side of the cutting insert 50′″, between two neighboring corners.
[0197] Turning now to
[0198] With particular reference being made to
[0199] In addition, each insert seat space 220 comprises an inlet 226 configured for provisional cooling fluid into the insert seat space 220 and an outlet 228 configured for removal of cooling fluid therefrom. As opposed to the cutting tool 1 previously described, in this case there is no base plate 30, and the insert seat space 220 itself serves as a base plate.
[0200] Thus, the seat surface 222 is formed with a ramp element 240 projecting from the insert seat space 220 and has a body 242 with a ramp surface 244, an inlet channel 246 and an outlet channel 248 merging with respective inlet and outlet 226, 228. It is also noted that the outlet 228 extends along the insert seat space 220 and has a discharge opening 229 at the rear side of the insert seat space 220, the purpose of which will not be explained.
[0201] Turning to
[0202] In this case, the cooling fluid is discharged from the insert seat space 220 via discharge opening 229. It is noted here that the discharge opening 229 is arranged such the discharged fluid is aimed at the cutting corner of the subsequent cutting insert 250, so it also serves as an addition to the standard external cooling. However, it is noted that the cooling fluid passing through the insert seat space 220 is not used for external cooling of the cutting edge of the cutting insert mounted into that insert seat space.
[0203] Reference is now made to
[0204] With reference to
[0205] With regards to all of the above cutting inserts 50, 50, 50, 50′″ and 250—all can be manufactured in a pressing/sintering process, allowing for convenient mass production of the cutting inserts.
[0206] Attention is now drawn to
[0207] As seen in
[0208] Such an orientation of the insert bore allows forming the cooling cavities 460 closer to the cutting edge 454, since the diagonal orientation leaves more material area to be worked with. This, in turn, allows for a more robust structure of the cutting insert, the mechanical integrity of which is not greatly deteriorated due to the forming of the cooling cavity 460.
[0209] It is observed that the cooling cavity 460 is of conical shape spanning between an open bottom end 460B and a top end 460T, facilitating concentrating the flow of cooling fluid therewithin towards an area of the cutting insert 450 directly adjacent and behind the cutting edge 454 (the flow being designated by arrows 428). In particular, for example as best seen in
[0210] It will be appreciated that owing to the disposition of the top end 460T of each cooling cavity 460 forward of the open bottom end 460B thereof, a portion of the cavity is above material of the cutting insert 450 (i.e., a straight path perpendicular from the bottom surface 452.sub.B to at least some of the cavity passes through material of the insert; along an axis parallel to the top and bottom surfaces 452.sub.T, 452.sub.B, the top end 460T of the cooling cavity 460 is closer to the respective cutting edge than is any part of the open bottom end 460B). Accordingly, a molding process to manufacture the cutting insert 450 must be performed so as to produce it at an angle, as will be described below.
[0211] The geometry of the cooling cavity 460 therefore defines one or more (e.g., a range) molding angles, with respect to the bottom surface 452.sub.B, along which a solid element having the shape of the cooling cavity and completely inserted therein (such as part of a mold) may be retracted therefrom along a linear path. Accordingly, the cutting insert 450 is associated with a molding axis M (for example as indicated in
[0212] The circumscribing portion 462 has a non-zero height, in a direction parallel to the molding axis M, along its entire extent (i.e., the entire way around the circumscribing portion). The significance of the non-zero height will be explained below with respect to the molding process; it will be understood that such explanation will inform one having skill in the art the scope of the term “non-zero height” in the presently disclosed subject matter and appended claims. As illustrated, the height of the circumscribing portion 462 may vary along its extend around the cutting insert 450), or it may be constant thereabout.
[0213] Furthermore, the cutting insert 450 does not extend beyond the circumscribing portion 462, i.e., in any plane in which the molding axis lies, there is no material of the cutting insert beyond the circumscribing portion. Accordingly, for example as best seen in
[0214] As seen for example in
[0215] The shelf 459 may be formed such that it generally faces (i.e., it is disposed so as to face the general direction of) either the top surface 452.sub.T or the bottom surface 452.sub.B. It will be appreciated that while the cutting insert 450 is described herein with reference to and illustrated in the accompanying figures as being formed with shelves 459 on two of its sidewalls 452s, and in particular two adjacent sidewalls between which one of the cooling cavities 460 is disposed, a cutting insert 450 may be provided according to the presently disclosed subject matter having one or more shelves as described above with reference to and as illustrated in the accompanying drawings being formed on fewer or more of the sidewalls, including, but not limited to, on all of the sidewalls, mutatis mutandis.
[0216] Turning now to
[0217] Each of the imprinting surfaces 517a, 517b has a shape which corresponds to that of a respective part of the cutting insert 450 when it is oriented such that its molding axis M is parallel to the sidewalls 511 of the female mold portion 510, each of the parts being demarcated by one of the edges 463a, 463b of the circumscribing portion 462. In particular, each of the imprinting surfaces 517a, 517b comprises a protrusion 540 corresponding to a respective cooling cavity 460. Accordingly, when the cutting insert 450 is produced within the mold 501, the circumscribing portion 462 is defined by the portion of the sidewalls 511 of the female mold portion 510 between the first and second imprinting surfaces 517a, 517b, i.e., it is formed abutting them. Thus, the cavity 515, when the first and second imprinting surfaces 517a, 517b are suitably spaced from one another, has the shape of the cutting insert 450 described above with reference to and illustrated in
[0218] It will be appreciated that the cutting insert 450 is produced by the mold 501 oriented such that its molding axis M is parallel to the longitudinal axis X of the mold 501, i.e., the top and bottom surfaces 452.sub.T, 452.sub.B of the cutting insert are oriented) at an angle with respect to the longitudinal axis X of the mold (the axis along which the mold portions 510, 530 are displaced when pressing) corresponding to the molding angle M. This permits the protrusions 540 to be withdrawn from their respective cooling cavities 460 without being damaged or causing damage to the cutting insert 450. As a result, the cooling cavities 460, which are formed generally along the longitudinal axis, are eventually angled to the cutting edge 454 of the cutting insert 450 at the desired angle.
[0219] It is important to note that while the pressing is performed along a pressing axis which extends generally along the longitudinal direction of the male and female member, the operative surfaces of the latter, the ones used to form the top and bottom surfaces of the cutting insert are angled at 45° to the pressing axis, allowing the forming of the cavity at the desired angle.
[0220] As illustrated in
[0221] In a first step 571 of the method 570, a mold 501, for example as described above with reference to and illustrated in
[0222] In a second step 572 of the method 570, raw material is provided in the cavity 515 of the female mold portion 510 of the mold 501. The amount of raw material is suitable for forming one cutting insert 450, i.e., its volume after the molding process is equal to that of the cutting insert.
[0223] In a third step 573 of the method 570, the male mold portion 530 is inserted into the cavity 515, such that the first and second imprinting surfaces 517a, 517b face one another.
[0224] In a fourth step 574 of the method 570, the cutting insert 450 is formed, in the space of the cavity 515 between the first and second imprinting surfaces 517a, 517b, from the raw material.
[0225] It will be appreciated that during molding of the cutting insert 450, the first and second imprinting surfaces 517a, 517b are spaced from one another, which gives rise to the non-zero height of the circumscribing portion 462. Accordingly, molding the cutting insert 450 having a circumscribing portion 462 as described above with a non-zero height, allows the female and male mold portions 510, 530 to be pressed toward one another without contacting each other, which could result in damage thereto. Similarly, the shelf 459 further facilitates pressing the female and male mold portions 510, 530 toward one another without contacting one another.
[0226] The raw material provided in the second step 572 may be any suitable material, and the forming of the fourth step 574 may be by any process suitable to the raw material. According to some examples, the raw material is a sintering material, for example comprising a ceramic powder, and the forming comprises providing suitable pressure for sintering. According to other examples, the raw material comprises one or more metals, for example provided in liquid form, and the forming comprises allowing the raw material to solidify, e.g., by cooling.
[0227] Turning now to
[0228] Similar elements have been designated with similar reference numbers, with the addition of 600 (i.e., cutting insert 650 uses a similar reference number as cutting insert 450, both having cutting edge 454, 654 etc.)
[0229] However, contrary to the previous example, the cutting insert 650 comprises two portions which are angled to one another at 135°, yielding that the cooling cavities 660 are generally parallel to one another.
[0230] This provides a very important advantage with respect to the pressing process. In particular, contrary to the previous example which required forming the cutting insert 450 at an orientation angled to the pressing axis, in this example, the cutting insert 650 can be formed symmetrically with the pressing axis as the projections forming the cooling cavities 660 extend generally along the pressing axis.
[0231] The above yields an angled configuration of the cutting insert itself 650, in this particular example, each portion of the cutting insert is of a triangular shape, the portions being angled to one another, as shown in
[0232] In addition, with particular reference being made to
[0233] Reverting back to
[0234] The flow channel 659 merges with the chip breaking channel 656 of the cutting insert 650, allowing fluid flow to reach very close to the cutting edge 654 and, at the same time, lift chips removed from the workpiece during a cutting operation.
[0235] Attention is now drawn to
[0236] The main differences between the cutting tool 601′ and 601 are as follows:
[0237] First of all, the holder 610′ is designed with an additional flow channel 618′ and 619′ (
[0238] Secondly, the flow channel 659′ is provided with a blocker 651′ which is configured for preventing chips removed from the workpiece by the cutting edge 654′ from flowing towards the outlet 657′ and blocking it. On the other hand, the blocker 651′ has a stream-line design configured for minimally obstructing cooling fluid emitted from the outlet 657′ towards the cutting edge 654′ (see
[0239] Contrary to the previously described example 601, the cutting insert 650′ further comprises supports 690 in the form of triangular projections 692′ and 694′, configured for being received with the holder 610′. The arrangement of the supports 692′, 694′ is such that allows the cutting insert 650′ more surface contact with the holder 610′ (compared to the example 601).
[0240] Since the bottom surface of the other portion of the cutting insert (the one that, at a given moment, does not perform a cutting operation) is not mated against a base surface of the holder 610′, the supports 692′, 694′ allow preventing a see-saw motion of the cutting insert which could lead to disengagement between the bottom surface 652B′ of the operational cutting portion and the plate 630′.
[0241] Attention is now drawn to
[0242] The main difference between the cutting insert 650″ and the previously described cutting insert 650′ lies in the design of the bottom surface of the cutting insert, 652B″. Whereas the previous cutting insert 650′ was shown to have a see-saw configuration, the cutting insert 650″ has a flat bottom surface 652B″.
[0243] With particular reference being made to
[0244] Attention is now drawn to
[0245] The main difference between the cutting tool 601′″ and the cutting tool 601″ lies in the fastening mechanism used to secure the cutting insert 650′″ to the tool holder 610′″. In particular, a clamping mechanism 700 is used, which operates in conjunction with a recess 635′″ of the cutting insert 650′″, contrary to an insert bore as described with respect to the previous examples.
[0246] Turning now to
[0247] Similar elements have been designated with similar reference numbers, with the addition of 800 (i.e., cutting insert 850 uses a similar reference number as cutting insert 650, both having cutting edge 654, 854 etc.).
[0248] The cutting insert 850 is formed with openings along the circumference thereof configured for allowing cooling fluid to flow therein and reach the entire length of the cutting edge 854 of the cutting insert 850.
[0249] Cooling fluid is provided through the cutting tool holder 810 and intermediate plate 830, and emitted from outlets O (see
[0250] It is noted that the wall of the openings are arranged so as to face the cutting corner of the cutting insert 850 (rather than being perpendicular to the side surfaces 852s of the cutting insert 850).
[0251] Turning now to
[0252] In addition, as shown in
[0253] A first portion of the cooling fluid is directed, similar to cutting tool 601′, back towards the relief surface of the cutting insert 950 via outlet 919b.
[0254] A second portion of the cooling fluid is directed backwards to impact the cutting edge of the subsequent milling insert 950, via outlets 918b.
[0255] In this manner, cooling fluid usage is somewhat optimized to remove heat not only from the cutting insert to which it is originally directed but from a subsequent cutting insert as well. It is appreciated that the subsequent cutting insert has a cooling mechanism of its own and that a portion of the cooling fluid used therein is directed to a cutting insert subsequent thereto and so on, and so forth.
[0256] Attention is now brought to
[0257] In the example described herein, as in previous examples, the cooling cavity 1136 almost reaches the cutting edge 1154 of the drilling tool 1101, allowing to provide cooling fluid directly to the cutting edge 1154.
[0258] However, due to the geometry of the drilling tool 1101 (see
[0259] In particular, when the drilling tool 1101 revolves with respect to the workpiece, the bottom surface of the bore formed in the workpiece constantly carries away with it, during respective turning of the drilling tool, the cooling fluid “stuck” at the dead-end and removes it from the area. This also allows breaking up the boundary layers at the front surface of the drill, allowing for more efficient cooling and fluid flow.
[0260] With particular reference to
[0261] It will be appreciated that while examples described herein with reference to and as illustrated in the accompanying drawing relate to a cutting insert, this is by way of illustrating a non-limiting example only, and are not to be construed as limiting to a cutting insert. The teachings of this disclosure may be applied to any suitable cutting element, and cutting elements provided in accordance with the teachings of this disclosure are included within the scope of the presently disclosed subject matter, mutatis mutandis.
[0262] Those skilled in the art to which this invention pertains will readily appreciate that numerous changes, variations, and modifications can be made without departing from the scope of the invention, mutatis mutandis.