SE1451021A1

SE1451021A1 - Cassette for a milling cutter

Info

Publication number: SE1451021A1
Application number: SE1451021A
Authority: SE
Inventors: Jeffrey Kovac; Armin Zimmermann; Xaver Spichtinger; Johann Schneider; Thomas Lehmann
Original assignee: Kennametal Inc
Priority date: 2013-09-03
Filing date: 2014-09-03
Publication date: 2015-03-04
Also published as: KR20150026885A; DE102014111637A1; CN104416211A; JP2015047693A

Abstract

The invention relates to a cassette for a milling cutter having a cutter carrier and a clamping part, which together constitute a generally rectangular cassette, the cutter carrier and the clamping part being loosely placed on each other and together delimiting a fastening opening for a fastening screw by means of which the cassette can be fastened in a receiver of a milling cutter, the cutter carrier having a seat for a cutting insert. The invention additionally relates to a milling cutter having at least one receiver for a cassette and having at least one such cassette. A gap, S, between the cutter carrier and the clamping part is located below the cutting tip of the cutting insert to prevent chips from being lodged in the gap, S.

Description

CASSETTE FOR A MILLING CUTTER CLAIM TO PRIORITY This application is a continuation-in-part of Application Serial No. 13/ 894,497, filed onMay 15, 2013, which is a National Entry application of Gerrnan Application No.102012009739.5, filed on May 16, 2012, the entire contents of both these applications are incorporated herein by reference.

FIELD OF THE INVENTION

[0001] The invention relates to a cassette for a milling cutter, by means of whicha cutting insert can be adjustably attached to the milling cutter. The invention additionally relates to a milling cutter having such a cassette.

BACKGROUND OF THE INVENTION

[0002] Such a milling cutter having a cassette is known in principle from EP 1 753 577 Bl. The cassette can be adjustably mounted in a receiveron the milling cutter by means of a fastening screw and an adjustingscrew. When the cutting insert of the cassette has become wom, the cutting insert can be remachined, or the entire cassette has to be replaced.

SUMMARY OF THE INVENTION

[0003] The object of the invention consists in developing the known cassette insuch a way that the economic efficiency of the milling cutter system usedis increased.

[0004] To achieve this object, there is provided according to the invention a cassette for a milling cutter, having a cutter carrier and a clamping part,which together constitute a generally rectangular cassette, the cuttercarrier and the clamping part being loosely placed on each other andtogether delimiting a fastening opening for a fastening screw by means ofwhich the cassette can be fastened in a receiver of a milling cutter, thecutter carrier having a seat for a cutting insert. The invention is based onthe fundamental concept of dividing the hitherto known cassette into twoparts that are placed loosely on each other, of which one carries the cutting insert and the other effects clamping and support. Both parts

[0005]

[0006]

[0007]

[0008]

[0009]

[00010]

[00011] together, as a Whole, constitute the cassette, which, in respect of itsdimensions, corresponds to the hitherto known cassette. Consequentlythe cassettes used hitherto can be replaced by the new cassettes. Theparticular advantage of the new, divided cassettes consists in that, in thecase of wear, only a part of the cassette need be replaced, namely thecutter carrier, while the other part, i.e. the clamping part, can continue tobe used. As a result, the operating costs are reduced.

According to one embodiment, it is provided that the cutting insert isfixedly mounted on the cutter carrier, in particular soldered or adhesive-bonded into the seat. This is advantageous, in particular, if cuttinginserts made of PCD (polycrystalline diamond) are used.

According to an alternative embodiment, it is provided that the cuttinginsert is inserted in the seat on the cutter carrier. This enables theoperating costs to be reduced yet ﬁarther, since, in the case of wear, it isonly the cutting insert, and not the cutter carrier, that has to be replaced.Preferably, it is provided that the cutting insert is locked positively, in theseat, against displacement in at least one direction. Consequently, thecutting insert is then already reliably fixed in the seat even when thecassette has only been premounted in a preliminary manner on themilling cutter and has not yet been finally clamped.

According to one design of the invention, it is provided that the clampingpart has a support portion, which def1nes an outside face of the cassettethat faces away from the seat for the cutting insert. This ensures that acontinuous, undivided surface is available for positioning the cassette.

It is preferably provided in this case that the support portion terrninatesjust above the bottom surface of the cutter carrier. This prevents amechanical overdeterrnination from coming about when the cassette is inthe mounted state.

According to a preferred embodiment of the invention, it is provided thatthe parting line between the cutter carrier and the clamping part, inrelation to a center line of the fastening opening, runs closer to theclamping part than to the cutter carrier. This offset, which, in particular,can be in the order of magnitude of 20 % of the smallest diameter of thefastening opening, has proved to be particularly advantageous in amechanical respect.

Preferably, it is provided that the clamping part has a clamping surfacethat is located at the end of the clamping part facing away from the

[00012]

[00013]

[00014] support portion, and that is supported on the cutter carrier in the region ofthe seat, or close to the latter. The clamping surface can be used, on theone hand, to transfer the exerted clamping force on to the cutter carrier.If a separate cutting insert, inserted in the seat, is used, the clampingsurface can be used, on the other hand, to clamp the cutting insert in theseat.

According to a preferred embodiment of the invention, there is a slotbetween the cutter part and the clamping part, which slot extends,starting from the clamping portion, beyond the region of the fasteningopening, to the support portion. The slot also serves to preventoverdeterrninations, such that it is reliably ensured that the desiredclamping force is applied via the clamping surface.

According to one embodiment of the invention, at least one coolantchannel is provided in the clamping part. This enables coolant to besupplied to a cutter on the cutting insert.

The coolant channel can extend from a side surface of the clamping partto an outer surface of the clamping part that is disposed above the seat forthe cutting insert. It can also be provided that the coolant channelextends from a top side of the clamping part to this outer surface. Thecourse of the coolant channel can thus be adapted in a ﬂexible manner tothe milling cutter and to the arrangement of coolant supply openings on the milling cutter.

BRIEF DESCRIPTION OF THE DRAWINGS

[00015]

[00016]

[00017][00018][00019][00020][00021][00022] The invention is described in the following on the basis of variousembodiments, which are represented in the appended drawings. In thedrawings: Figure l shows a schematic bottom view of a milling cutter according tothe invention, having cassettes according to the invention; Figure 2 shows the milling cutter from Figure l, in a side view; Figure 3 shows the milling cutter from Figure l, in a perspective view;Figure 4 shows a side view of a cassette according to the invention;Figure 5 shows a top view of the cassette from Figure 4; Figure 6 shows a front view of the cassette from Figure 4; Figure 7 shows a first perspective view of a cassette according to a first embodiment of the invention;

[00023]

[00024]

[00025]

[00026]

[00027]

[00028]

[00029]

[00030][00031] Figure 8 shows a second perspective view of the cassette according to thefirst enibodinient; Figure 9 shows the cutter carrier of the cassette according to the firstenibodinient, in a perspective view; Figure 10 shows the clan1ping part of the cassette according to the firstenibodinient, in a perspective view; Figure 11 shows a perspective view of a cassette according to a secondenibodinient; Figure 12 shows a perspective view of a cassette according to a thirdenibodinient; Figure 13 shows a broken top view of a cutter carrier with a cutting insertfor a cassette, according to a fourth enibodinient; Figure 14 shows a side view of a cassette according to a fourthenibodinient; Figure 15 shows a top view of the cassette froni Figure 14; and Figure 16 shows a front view of the cassette from Figure 14.

DETAILED DESCRIPTION OF THE INVENTION

[00032]

[00033] Figures 1 to 3 show a n1illing cutter 1, which has a tool basic body 2having the general shape of a cylinder, or hollow cylinder. The toolbasic body can be con1posed of aluniinuni, titaniuni, steel or anothersuitable material. On its lateral circun1ferential surface 3, the tool basicbody 2 carries a niultiplicity of cassettes 4, which are disposed in auniforrnly distributed manner on the outer circuniference of the tool basicbody 2. Alternatively, it is possible for the cassettes 4 to be disposedwith an irregular spacing on the outer circuniference of the tool basicbody 2. Provided between the cassettes 4 in the tool basic body 2, in theregion of the circun1ferential surface 3, there are chip guide ﬂutes 6. Thelatter directly adjoin chip guide surfaces 7, which are integrated into eachcassette 4.

Each cassette 4 is attached to the tool basic body 2 in a receiver 21 thatclosely surrounds the respective cassette 4. Provided for the purpose offastening to the tool basic body there is a fastening screw 23, whichextends through the cassette 4. An adjusting screw 32 is assigned to each cassette, for precise setting of the position of the cassette.

[00034]

[00035]

[00036]

[00037]

[00038]

[00039]

[00040] In respect of further details of the mounting of the cassettes 4 and theiradjustment on the milling cutter 1, reference is made to EP 1 753 577.Figures 4 to 10 show a first embodiment of the cassettes 4. Each cassetteconsists of a cutter carrier 40 and a clamping part 70, which are realizedas discrete, separate components and, when put together, result in thegenerally rectangular cassette (see Figure 4), through which there extendsa fastening opening 72.

The cutter carrier 40 itself is again generally rectangular (see Figure 9),and at one corner has a cutting insert 42, which is fixedly connected hereto the cutter carrier 40. The cutting insert 42 can be composed, forexample, of polycrystalline diamond, and can be soldered or adhesive-bonded into an appropriately shaped seat 44 on the cutter carrier 40.

The cutter carrier 40 is additionally provided with a recess, which is partof the fastening opening 72. As can be seen in Figure 4, the center axisM of the fastening opening 72 is located beneath the parting planebetween the cutter carrier 40 and the clamping part 70, such that thedistance between the two edges of the recess for the fastening opening,measured at the edge of the cutter carrier 40 that, in relation to thefigures, is the upper edge, is less than the diameter of the fasteningopening. The fastening opening itself has a portion A of a constantdiameter, which def1nes the smallest diameter of the fastening opening, aportion B, which widens in the form of a wedge, and a portion C, whichagain is of a constant diameter.

Insofar as terms such as "top", "bottom", "front", etc. are used here, theserelate merely to the representation in the drawings. In practice, thecassette can be used in any optional orientation and, when in use, thespatial orientation alters in dependence on the orientation and rotation ofthe milling cutter.

The clamping part 70, as viewed in a side View, has a general L shapeand, on one side, has a clamping surface 74, which is provided to besupported on the cutter carrier 40, and at the opposite end has a supportportion 76, which encompasses the outside of the cutter carrier 40 thatfaces away from the cutting insert 42.

At its front end that faces away from the support portion 76, theclamping part 70 is provided with a chip guide surface 7. The latter terrninates at a short distance from the seat 44 for the cutting insert 42.

[00041]

[00042]

[00043]

[00044]

[00045] Furthermore, in the clamping part 70, the "rest" of the fastening opening72 is provided in the forrn of a recess.

When the clamping part 70 has been placed on the cutter carrier 40 (see,in particular, Figure 4), the support portion 76 terrninates at a shortdistance a above the plane that is defined by the bottom surface B of thecutter carrier 40. As a result, the outer contour of the cassette 4, inrelation to Figure 4, is defined, on the top side and back side of thecassette, solely by the outer faces of the clamping part 70 and, on theunderside, solely by the bottom surface B of the cutter carrier 40. Inparticular, a continuous, homogeneous bearing surface 78 is therebyobtained in the region of the adjusting screw 32. The dimensions of thecutter carrier 40 and of the clamping part 70 are selected such that theclamping part 70 is supported on the cutter carrier 40 only in the regionof the clamping surface 74, i.e. at its front end, and there is otherwise agap S, between the cutter carrier 40 and the clamping part 70, that,starting from the clamping surface 74, extends beyond the region of thefastening opening 72 and into the region in which the support portion 76is located.

The cassette 4 is inserted in the corresponding receiver 21 of the millingcutter 1 such that the cutting insert 42 is located on the outside. Thecassette is fastened in the cassette by means of the fastening screw 23,the fastening screw 23, as such, tending to force apart the two parts,cutter carrier 40 and clamping part 70. Owing to the dimensions andshape of the receiver 21, however, the two parts are held fixedly togetheras a unit, and can be appropriately adjusted in the receiver.

If the cutting insert 42 has become wom, it can either be remachined orreplaced together with the cutter carrier 40. The clamping part 70,however, can continue to be used in each case.

Figure 11 shows a cassette according to a second embodiment. Thedifference in relation to the first embodiment consists in that provided inthe clamping part 70 there is a coolant channel 80, which extendsbetween the chip guide surface 7 and, in relation to Figure 11, the topside of the clamping part 70. As a result, when the cassette 4 has beenmounted in the milling cutter 1, coolant can be directed specif1cally tothe cutting insert 42, via a coolant supply opening, which is disposed in one of the side surfaces of the receiver 21 of the milling cutter.

[00046]

[00047]

[00048]

[00049]

[00050] Figure 12 shows a third embodiment, Which differs from the secondembodiment in the disposition of the coolant channel 80. In the case ofthe third embodiment, the coolant channel 80 terrninates on a side surfaceof the cassette 4, such that the coolant can be directed to the cutting insert42 or, more precisely, to the cutting edge thereof, via a coolant supplyopening provided on the bottom of the receiver 21 in the milling cutter 1.Figure 13 shows a fourth embodiment, Which differs from the first threeembodiments in respect of the cutting insert 42. In the case of the fourthembodiment, the cutting insert 42 is not fixedly soldered-in, but isrealized as an indexable cutting insert, Which is inserted in the seat 44.There, it is fixed by means of the clamping action exerted by theclamping part 70 and, in particular, by the clamping surface 74 thereof.In addition, the cutting insert 42 is locked positively in the seat 44. Forthis purpose, retaining proj ections 50 are provided on the seat, Whichprojections engage in appropriate recesses 52 on the cutting insert 42.

In the case of the fourth embodiment, likeWise, coolant channels can beprovided in the clamping part 70.

Figures 14 to 16 shoW a f1fth embodiment, Which differs from the firstfour embodiments in respect to the relative location of the gap, S,between the cutter carrier 40 and the clamping part 70, and the cutting tip82 of the cutting insert 42. In particular, the gap, S, is located beloW thecutting tip 82 of the cutting insert 42 as shown in Figures 14 and 16. Asa result, chips forrned during a cutting operation are prevented frombeing lodged Within the gap, S.

Claims

WHAT IS CLAIMED IS:

1. A cassette for a milling cutter, having a cutter carrier and a clamping part, Which together constitute a generally rectangular cassette, the cutter carrier and theclamping part being loosely placed on each other and together delimiting a fasteningopening for a fastening screw by means of which the cassette can be fastened in areceiver of a milling cutter, the cutter carrier having a seat for a cutting insert havinga cutting tip, wherein a gap, S, between the cutter carrier and the clamping part islocated below a cutting tip of the cutting insert. . The cassette as claimed in claim 1, wherein the cutting insert is fixedly mounted on the cutter carrier. . The cassette as claimed in claim 1, wherein the cutting insert is inserted in the seat on the cutter carrier. . The cassette as claimed in claim 3, wherein the cutting insert is locked positively in the seat against displacement in at least one direction. . The cassette as claimed in claim 1, wherein the clamping part has a support portion, which def1nes an outside face of the cassette that faces away from the seat for thecutting insert. . The cassette as claimed in claim 5, wherein the support portion terrninates just above the bottom surface of the cutter carrier. . The cassette as claimed in claim 1, wherein the parting line between the cutter carrier and the clamping part, in relation to a center line of the fastening opening, runs closerto the clamping part than to the cutter carrier. . The cassette as claimed in claim 1, wherein the clamping part has a clamping surface that is located at the end of the clamping part facing away from the support portion,and that is supported on the cutter carrier in the region of the seat, or close to thelatter. 10. 11. 1

2. 1

3. The cassette as claimed in claim 1, Wherein there is a slot between the cutter carrierand the clamping part, Which slot extends, starting from the clamping surface beyond the region of the fastening opening to the support portion. The cassette as claimed in claim 1, Wherein at least one coolant channel is provided in the clamping part. The cassette as claimed in claim 10, Wherein the coolant channel extends from aside surface of the clamping part to an outer surface of the clamping part that is disposed above the seat for the cutting insert. The cassette as claimed in claim 10, Wherein the coolant channel extends from a topside of the clamping part to an outer surface of the clamping part that is disposed above the seat for the cutting insert. A milling cutter having at least one receiver for a cassette and having at least one cassette according to claim 1.