DK172572B1

DK172572B1 - Elongate holding element with at least two cutting elements

Info

Publication number: DK172572B1
Application number: DK86495A
Authority: DK
Inventors: Niels Joergen Hansen
Original assignee: Niels Joergen Hansen
Priority date: 1995-07-27
Filing date: 1995-07-27
Publication date: 1999-01-25
Also published as: DK86495A

Description

DK PR 172572 B1 iDK PR 172572 B1 i

Opfindelsen angår et langstrakt holdeorgan af den art, der er angivet i indledningen til krav 1.The invention relates to an elongated holding member of the kind set forth in the preamble of claim 1.

Fra fig. 49-52 og den hertil hørende tekst i DE-A-3.600.077 kendes en værktøjsholder, der udviser de 5 træk, der som nævnt ovenfor er angivet i indledningen til krav 1. I dette skrift er holderen beskrevet som del af en ende-fræser, men det nævnte værktøj kan selvsagt også anvendes som et boreværktøj, således som det er tilfældet med mange ende-fræsere med et lille antal skær. Indtil nu har 10 man anset det for vigtigt, at en værktøj sholder af denne art, for at kunne fungere godt i en boreoperation, er symmetrisk om sin længdeakse for at undgå ustabilitet ved høje bearbejdningshastigheder, dvs. når der pr. tidsenhed fjernes en stor mængde materiale, og denne symmetribetingelse er 15 da også opfyldt ved det værktøj, der er vist og beskrevet i det nævnte skrift.From FIG. 49-52 and the associated text in DE-A-3,600,077, a tool holder is known which exhibits the five features as mentioned above in the preamble of claim 1. In this specification, the holder is described as part of an end cap. cutters, but said tool can of course also be used as a drilling tool, as is the case with many end cutters with a small number of cutters. Up to now, it has been considered important that a tool holder of this kind, in order to function well in a drilling operation, be symmetrical about its longitudinal axis to avoid instability at high machining speeds, ie. when per time unit, a large amount of material is removed and this condition of symmetry is then also fulfilled by the tool shown and described in said publication.

Det er på denne baggrund opfindelsens formål at anvise et holdeorgan af den indledningsvis nævnte art, hvormed det på en yderst enkel måde er muligt at opnå høje bearbejdnings-20 hastigheder, og dette formål opnås ved hjælp af de træk, der er angivet i den kendetegnende del af krav 1. Hed et holdeorgan, der udviser disse træk, har det vist sig muligt at opnå højere bearbejdningshastigheder end med holdeorganer, hvori skærene er anbragt og orienteret på den sædvanlige 25 symmetriske måde, og den ustabilitet, der kunne forventes, optræder ikke.Accordingly, it is the object of the invention to provide a holding means of the type mentioned in the first, with which it is possible in a very simple manner to obtain high machining speeds, and this object is achieved by the features specified in the characterizing part of claim 1. With a holding member exhibiting these features, it has been found possible to achieve higher machining speeds than with holding means in which the cutters are arranged and oriented in the usual symmetrical manner and the expected instability does not occur. .

Hensigtsmæssige udførelsesformer for holdeorganet ifølge opfindelsen er angivet i krav 2-3.Suitable embodiments of the holding means according to the invention are set out in claims 2-3.

Opfindelsen skal i det følgende forklares nærmere 30 under henvisning til det på tegningen viste udførelseseksempel på et holdeorgan ifølge opfindelsen, idet fig. 1 viser en borholder med påsatte hårdmetalskær, set forfra i retning af pilen I i fig. 2, tilligemed det hul i arbejdsemnet, der er ved at blive boret, og 35 fig. 2 viser det i fig. 1 viste bor, set fra siden i retning af pilen II i fig. 1.BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in greater detail below with reference to the embodiment of a holding device according to the invention shown in the drawing. 1 is a front view of a drill holder with cemented carbide inserts in the direction of arrow I in FIG. 2, as well as the hole in the workpiece being drilled, and FIG. 2 shows that in FIG. 1 in the direction of arrow II in FIG. First

2 DK PR 172572 B12 DK PR 172572 B1

Fig. 1 og 2 viser den forreste ende af et bor bestående af en langstrakt borholder 1, hvoraf kun den forreste ende 2 er vist, og som på i grove træk velkendt måde bærer to hårdmetalskær, nemlig et første skær 3 med sin tilhørende 5 første skæreæg 4 og et andet skær 5 med sin tilhørende anden skæreæg 6.FIG. 1 and 2 show the front end of a drill consisting of an elongated drill holder 1, of which only the front end 2 is shown, and which in a well-known manner carries two cemented carbide inserts, namely a first cutter 3 with its associated first cutting edge 4 and a second cutting 5 with its associated second cutting egg 6.

Skærene 3 og 5 er på kendt måde udformet stort set som ligesidede trekanter, hvori hjørnerne er afrundet og siderne knækket udad på midten, så at skæreæggene 4 og 6 får en af-10 fladet V-form. Skærene 3 og 4 er fastgjort til borholderen 1 på kendt, ikke nærmere vist m&de, således at de kan udtages og vendes og/eller udskiftes.The inserts 3 and 5 are in a known manner formed essentially as equilateral triangles in which the corners are rounded and the sides cracked outwards in the middle, so that the cutting edges 4 and 6 have a flattened V-shape. The inserts 3 and 4 are attached to the drill holder 1 in a known manner, not shown in detail, so that they can be removed and turned and / or replaced.

som det vil kunne ses af fig. 1, ligger den første skæreæg 4 på et meridianplan 7 og strækker sig fra et sted 15 i nærheden af boreaksen 8 til et ydre hjørne 9 i en ikke ubetydelig afstand fra borholderens periferi 10.as will be seen in FIG. 1, the first cutting egg 4 lies on a meridian plane 7 and extends from a location 15 in the vicinity of the drill axis 8 to an outer corner 9 at a not insignificant distance from the periphery 10 of the drill holder.

Den anden skæreæg 6 ligger i et aksialplan 11, som skærer meridianplanet 7 ved det ydre hjørne 9 under en vinkel 12 på mellem 1 og 4°, idet den anden skæreæg 6 strækker sig 20 fra et sted i en ikke ubetydelig afstand fra boreaksen 8 til et ydre hjørne 13, der definerer periferien 14 i det borede hul.The second cutting egg 6 lies in an axial plane 11 which intersects the meridian plane 7 at the outer corner 9 at an angle 12 of between 1 and 4 °, the second cutting egg 6 extending 20 from a location at a not insignificant distance from the drill axis 8 to an outer corner 13 defining the periphery 14 of the drilled hole.

Som det fremgår af fig. 2, er de to skær 3 og 5 således aksialforskudt indbyrdes, at det første skær 3, regnet 25 i borets fremdrivningsretning 19, ligger med en lille afstand 20 bagud, dvs. at belastningen på det andet skær 5 bliver størst. Desuden er skærene således orienteret om sine midterakser, at den inderste halvdel af den første skæreæg 4 danner en vinkel 15 på mellem 8° og 10° med et radialplan 30 16, medens den yderste halvdel af den anden skæreæg 6 danner en vinkel 17 på mellem 5° og 7° med dette radialplan.As shown in FIG. 2, the two inserts 3 and 5 are so axially displaced that the first insert 3, counted 25 in the direction of propulsion 19 of the drill, lies at a small distance 20 backwards, i.e. that the load on the second cutter 5 becomes greatest. In addition, the inserts are oriented around their center axes such that the inner half of the first cutting egg 4 forms an angle 15 of between 8 ° and 10 ° with a radial plane 30 16, while the outer half of the second cutting egg 6 forms an angle 17 of between 5 ° and 7 ° with this radial plane.

Anbringelsen af det andet skær 5, dels i fremdriv-ningsretningen 19 foran det første skær 3, dels i omdrejningsretningen 18 foran en symmetrisk beliggenhed i forhold 35 til det første skær 3 bevirker, at den største skærekraft kommer til at ligge på det andet skær 5. Denne usymmetriske DK PR 172572 B1 3 anbringelse af det andet skær 5 i forhold til det første sker 3 ville normalt forventes at gøre det af borholderen 1 og de to sker 3 og 5 bestående bor ustabilt, dvs. at det højst sandsynligt vil udføre torsionssvingninger under en 5 boreoperation, hvad der på kendt måde medfører dannelse af bearbejdningsmærker i det borede huls periferi 14, og-ikke mindst - en ulidelig støj og risiko for ødelæggelse af skæret, men praktiske forsøg har vist, at dette ikke er tilfældet. En mulig forklaring kunne være, at den usymme-10 triske belastning bevirker en ensidig deformation af holderen 1 til en svagt ekscentrisk beliggenhed af dens frie ende, og at den herved opst&ede ensidige "forspending" forhindrer oscillationer.The placement of the second insert 5, partly in the direction of propulsion 19 in front of the first insert 3, and partly in the direction of rotation 18 in front of a symmetrical position with respect to the first insert 3, causes the greatest cutting force to lie on the second insert 5. This asymmetric DK PR 172572 B1 3 placement of the second insert 5 in relation to the first spoon 3 would normally be expected to make it unstable by the drill holder 1 and the two spoons 3 and 5, ie. that it is most likely to perform torsional vibrations during a drilling operation, which in a known manner results in the formation of machining marks on the periphery of the drilled hole 14, and - not least - an unbearable noise and risk of damage to the cutter, but practical tests have shown that this is not the case. One possible explanation could be that the unsymmetrical load causes a unilateral deformation of the holder 1 to a slightly eccentric location of its free end, and that the resulting unilateral "bias" prevents oscillations.

Forsøg er blevet udført med stål svarende til C 15, 15 9 SMnPb 28K, men andre ståltyper med tilsvarende svingnings dæmpende egenskaber kan selvsagt også bruges.Tests have been carried out with steel corresponding to C 15, 15 9 SMnPb 28K, but other steel types with similar vibration damping properties can of course also be used.

For at forhindre, at borholderen 1 slides ved berøringen med de fremkomne spåner, kan borholderen være således behandlet, at dens overflade bliver tilstrækkelig hård til, 20 at sådan slitage ikke opstår. Dersom borholderen 1 består af blødt stål som omtalt ovenfor, kan dette nemt opnås ved konventionel indsatshærdning, f.eks. i en dybde på ca. 0,5 mm og til en Rockwell-hårdhed mellem 55 og 60. Herved opnås tillige, at spånerne glider lettere på de pågældende over-25 flader, hvad der navnlig er af betydning ved store boredybder, hvor der nemt kan ske en "fastbrænding".In order to prevent the drill holder 1 from slipping on contact with the resulting chips, the drill holder may be so treated that its surface becomes sufficiently hard to prevent such wear from occurring. If the drill holder 1 is made of soft steel as discussed above, this can easily be achieved by conventional insert hardening, e.g. at a depth of approx. 0.5 mm and for a Rockwell hardness of between 55 and 60. This also ensures that the chips slip more easily on the relevant surfaces, which is especially important at large drilling depths where a "burn" can easily be achieved. .

DK PR 172572 B1 4DK PR 172572 B1 4

GENSTANDSFORTEGNELSEOBJECT LIST

1 borholder 2 forreste ende 3 første skær 5 4 første sksreæg 5 andet skær 6 anden sksresg 7 meridianplan 8 boreakse 10 9 ydre hjørne 10 periferi 11 aksialplan 12 vinkel 13 ydre hjørne 15 14 periferi 15 vinkel 16 radialplan 17 vinkel 18 omdrejningsretning 20 19 fremdrivningsretning 20 afstand1 drill holder 2 front end 3 first cutting 5 4 first cutting edge 5 second cutting 6 second cutting edge 7 meridian plane 8 drill axis 10 9 outer corner 10 peripheral 11 axial plane 12 angle 13 outer corner 15 14 peripheral 15 angle 16 radial plane 17 angle 18 direction of rotation 20 19 direction of travel 20 distance

Claims

An elongated retaining member (1) arranged at one end to be retained in a fixed or rotating part of a machining machine, e.g. a lathe or a drill, respectively, and at its other end retains at least two hard metal inserts (3.5) secured to the front end (3.5), which are arranged with their socket edges (4.6) facing substantially forward in that direction. (19), in which the tool of the cutting insert (1) and the cutting inserts (3,5) during a drilling operation moves through the drilled hole (14), the inserts (3,5) also being arranged with the cutting edges (4). 6) extending so that the cutting edge (4) of the first cutter (3) extends in a diametral plane (7) from a location close to the drill axis (8) to a location (9) at a distance from the periphery (14) for 15 the hole to be drilled while the cutting edges (6) of the second cutting insert (5) extend from a location at a distance from the drill axis (8) to said periphery (14), characterized in that: (a) the cutting edges (4, 6) ) are flat V-shaped with the tip of the V 20 facing forwardly in said direction (19), and b) that the cutting edge (6) of the second cutting insert (5) is located, partly, calculated in said direction (19), in front of the cutting edge (4) of the first cutting insert (3), partly, calculated in the working rotation direction (18) of the drill, in front of a symmetrical position 25. relative to the cutting edge (4) of the first cutting insert (3).

Holding device according to claim 1, characterized in that the cutting edge (6) of the second spoon (5) is located in a plane (1i) parallel to the drill axis (8) which touches the radially outermost point (9) of the cutting edge ( 4) on the first cutting insert (3) and forming an angle (12) of 1-4 ° with a diametral plane (7) extending through said outermost point (9). A holding member according to claim 1 or 2, characterized in that it is essentially a homogeneous body consisting of steel corresponding to C 15, 9 SMnPb 28K.