EP1954434A1

EP1954434A1 - Milling cutter head

Info

Publication number: EP1954434A1
Application number: EP06828547A
Authority: EP
Inventors: Markus Heinloth; Ralf KLÖTZER; Helmut Klein
Original assignee: Kennametal Widia Produktions GmbH and Co KG
Current assignee: Kennametal Widia Produktions GmbH and Co KG
Priority date: 2005-12-02
Filing date: 2006-11-21
Publication date: 2008-08-13
Also published as: RU2414333C2; CN101316675A; US20080279643A1; BRPI0619773A2; CA2629097A1; RU2008121564A; JP2009517231A; CN101316675B; DE202005018963U1; KR20080070051A; WO2007062622A1; US7841810B2

Abstract

The invention relates to a milling cutter head having a plurality of blade holders (11) which are inserted into recesses of a parent body (10) and on which respective blades (12) are brazed in position. According to the invention, at least one blade (12') is angled and has a longer section (c), lying radially on the outside with respect to the axis of the milling cutter head, and a shorter section (b) which lies radially on the inside and is angled at 3° to 7°, preferably 5°.

Description

milling head

The invention relates to a Fräsmesserkopf with several, used in recesses of a base cutter carriers, are soldered to the respective cutting, the blade carriers are each axially adjustable via a wedge body and fixed by means of clamping elements in Fräsmesserkopf.

Such a milling cutter head is known in principle from DE 40 03 862 C2. The recesses for the blade carrier extend in the blade head described therein of the one end face of its base parallel to the axis of rotation and at a distance from the circumference, the cutting edges of the cutting plates used protrude only slightly beyond the end face of the body. Furthermore, the axes of the round wedges serving for clamping are each skewed to the axes of the cutting plate carriers carrying the cutting plates. Finally, in each case another round wedge with differential screw for axial adjustment of each cutting plate is provided and arranged in a recess which extends radially inwardly from the circumference of the base body. For axial adjustment and radially outward bracing geometrically equal round wedges are used. As an advantage of this cutter head is highlighted that due to the location of the cutting plate carrier receiving recesses parallel to the axis of rotation of the body only radially directed centrifugal forces occur without axial component. These forces can be well intercepted, because the recesses are not located directly on the circumference of the body, but radially inwardly at a distance from the circumference. The knife head is therefore also suitable for extremely high speeds and the centrifugal forces occurring then. Advantageously, a fine adjustment of the cutting elements in the axial direction without interference with radial components is possible.

Such cutters are used in orthogonal rotary milling without axial feed with eccentric tool adjustment, especially in the car crankshaft production. For this purpose, the workpiece is processed in one or more revolutions with the multi-bladed milling cutter mentioned above. The workpiece turns opposite the cutter about its longitudinal axis, which is vertical to the cutter axis of rotation. Since the blades of the milling cutter head rotate with their points on different radii, different cutting arc lengths result, which causes the cause of uneven cutting edge stress along their length and consequently uneven wear.

In manufacturing technology, the price of an end product made by machining, in particular a crankshaft, is determined by several factors, including tooling and retooling costs.

It is therefore an object of the present invention to improve a Fräsmesserkopf of the type mentioned in that a longer blade life is reached.

This object is achieved by a Fräsmesserkopf according to claim 1.

According to the invention at least one of a plurality of cutting edges is angled and has with respect to the Fräsmesserkopfachse a longer radially outer portion and a radially inner shorter portion which is angled at 3 ° to 7 °, preferably 5 °, so that the two sections a Form angles of 177 ° to 173 °, preferably 175 °. By this measure, the shorter cutting edge sections are taken out of the cutting process at the beginning of the use of a fitted with new cutting cutter blade head. The longer cutting edge makes the final cut and thus wears faster than the short cutting edges. By the measure according to the invention, the convex surface profile is constantly adapted to the wear profile and thus maintained over a longer cutting contact time

Further developments of the invention are described in the subclaims. Thus, preferably, the aspect ratio of the shorter portion to the longer portion of the angled edge is selected to be between 4:17 and 6:17, preferably 5:17.

According to a specific embodiment of the invention, which will be discussed later, the milling cutter head has three blade carriers with cutting edges, which are arranged at an angle of 120 ° to each other. Preferably, one of three or two of three cutting edges is angled, while the non-angled cutting edge is linear.

Furthermore, it has a wear-reducing effect if the ends of the cutters are rounded, preferably at a radius of 0.1 mm and / or if the cutting edges themselves are rounded, preferably at a radius of 0.01 mm.

According to a further embodiment of the invention, the cutting edges consist of a hard metal, CBN or PCD body.

Further advantages and exemplary embodiments will be explained below with reference to the drawings, in which:

Fig. 1 is a perspective view of a Fräsmesserkopfes with three

Schneidenträgem,

2 is a plan view of the Fräsmesserkopf of FIG. 1,

3 is a wireframe-like representation of the Fräsmesserkopfes of FIG. 1,

Fig. 4 is a schematic diagram of the relative position of a blade carrier to a

Clamping piece and a wedge body for axial adjustment,

Fig. 5 is a side view of a cutter support with an angled

cutting, Fig. 6 is a detail view of the Schneidabwinklung and

7 shows a detailed view of a cutting edge of a cutter carrier according to FIG. 4.

The milling cutter head 10 essentially consists of a base body 10, in which three blade carriers 11 are arranged, each with soldered cutting edges 12. The blade carriers 11 are each used in parallel to the longitudinal axis 13 arranged bores. Leaning substantially in the radial direction or slightly inclined thereto, further bores are provided in the base body 10, in which wedge bodies 14 are arranged, which are displaceable in the radial direction via an adjusting screw 15, preferably a double-threaded screw. As can be seen from FIG. 4, these wedge bodies 14 have wedge surfaces 16 which run obliquely to the radial plane of the base body, so that during a radial movement of the wedge body 14, the blade carrier 11 is displaceable along its longitudinal axis, ie in the radial direction. For clamping the blade carrier 11 is a clamping ring 17 (see FIGS. 1 and 2) and a clamping piece 18 which is centrally located and three clamping surfaces 19 which bear against corresponding clamping surfaces 20 of the blade carrier. The clamping piece 18 can be fixed by means of a screw 21, which is preferably designed as a double-threaded screw. The clamping piece 18 is used in the illustrated embodiment for fixing three Schneidenträgem 11, each having a closed surface 20. Due to the design of the clamping piece and the arrangement of the clamping surfaces 19 in a triangle shape, an exact alignment of the blades, the blade carrier is achieved at an angle of 120 ° to each other. Each cutter carrier can be adjusted axially via the circular wedge 14 and the associated screw 15. For axially parallel alignment of the cutting inserts or the cutting insert carrier is the clamping ring 17, which is sleeve-shaped. The main body 10 and the clamping ring 17 have in the clamping state adjacent cylindrical surfaces. As shown in FIG. 4, the blade carrier 11 also has radially outside a narrow ground surface 21 which extends longitudinally axially. This surface 21 provides a double line contact between the clamping ring and the cutting insert. The difference between the at least in essence rectilinear cutting edges 12 and the angled cutting edge 12 'is particularly clear from Fig. 6 and 7. While the cutting edge 12 extends straight over almost its entire length and only over a minimum, outer area a of z. B. 0.5 mm at a total cutting length of 8.5 mm has a bevel inclined by 12 ° and at the other end a corner rounding with a radius R of 0.1 mm, it can be seen from Fig. 5 and 6, that at the radial inside, a cutting edge piece of length b, which extends at an 8.5 mm long edge length of 2.5 mm, is angled at 5 °. In addition, the corner is rounded even under a radius R of 0.1 mm.

In the illustrated embodiment, only one cutting edge is angled over a dimension b, whereas the other two cutting edges (except for the short-angular bend b and the edge rounding) are rectilinear.

According to an alternative, however, such Fräsmesserköpfe are detected in which two of three cutting edges are angled as shown in FIGS. 5 and 6. If the milling cutter head is used for orthogonal rotary milling or axial feed and eccentric tool adjustment, in particular crankshaft lateral surfaces can be produced with a significantly smaller rotary-milled jacket diameter.

The illustrated cutter is particularly suitable for orthogonal Drehfräsarbeiten, but also the fine milling of aluminum workpieces. A particular application of the milling cutter according to the invention is the finishing of crankshafts (instead of grinding), in particular, the wet grinding can be replaced, which has the disadvantage that contaminated cooling lubricants must be disposed of costly and laborious. The milling cutter head according to the invention fulfills high demands on concentricity, surface quality, convexity of the position of the seat and allows economical production of piece items.

Claims

claims

1. milling cutter head with a plurality of recesses in a base body (10) used cutting carriers (11), are soldered to the respective cutting edges (12), wherein the cutter support (11) via a wedge body (14) are axially adjustable and fixable by means of clamping elements in Fräsmesserkopf , characterized in that at least one cutting edge (12a) is angled and has a longer, relative to the Fräsmesserkopfachse radially outer portion (c) and a radially inner shorter portion (b), by 3 ° to 7 °, preferably 5 ° is angled so that the two sections (b, c) form an angle of 177 ° to 173 °, preferably 175 °.

2. Fräsmesserkopf according to claim 1, characterized in that the aspect ratio of the shorter portion (b) to the longer portion (c) of the angled cutting edge between 4:17 and 6:17, preferably 5:17.

3. milling cutter head according to claim 1 or 2, characterized by three blade carrier (11) with cutting edges (12, 12 '), which are arranged at an angle of 120 ° to each other.

4. Fräsmesserkopf according to claim 3, characterized in that only one or two of the three cutting edges (12, 12 ') is angled / are.

5. milling cutter head according to claim 1 to 4, characterized in that the ends of the cutting edges (12, 12 ') are rounded, preferably at a radius of 0.1 mm.

6. milling cutter head according to one of claims 1 to 5, characterized in that the cutting edges are rounded, preferably at a radius of 0.01 mm.

7. Fräsmesserkopf according to one of claims 1 to 6, characterized in that the radially outer region (a) of the cutting edge (12, 12 ') over a distance (a) of at most 1 mm, preferably 0.5 mm at an angle inclined by 12 °.

8. milling cutter head according to one of claims 1 to 7, characterized in that the cutting edges (12, 12 ') consist of a hard metal, CBN or PCD body (CBN = cubic boron nitride, PCD = polycrystalline diamond).