EP1033210B1 - Cutting insert, particularly for a milling tool - Google Patents

Abstract

The cutting plate (1) for a milling tool has a cutting edge and two bores (5,6) for fastening and positioning the plate in the tool carrier. The fixing bores have a polygonal cross section. A long edge of the polygonal section is parallel to the tool axis. Claims include tool assembly

Description

The invention relates to a cutting insert for a machining tool, in particular a milling tool, with at least one cutting edge and at least one first and a second breakthrough spaced therefrom for positioning and / or fastening of the cutting insert in the tool carrier body.

From DE 196 28 428 such a cutting plate is known, which is provided with two Präzisionsausnehmungen, with which it can be placed on projections provided in the tool support body. The precision recesses are produced by inserting into the tube apertures a foreign material unit having these precision recesses and bonding them therein, for example. The production of this insert is quite expensive.

DE 36 29 157 discloses a cutting plate which is provided with a circular and an elongated opening. In the breakthroughs engage locking pins of a clamping element to the positioning of the cutting plate support. The accuracy of the holes and their location is a high demand, so that an exact positioning is possible.

DE 76 02 409 U1 discloses a mounting holder for a cutting tool, in which the cutting plate is secured by a pin in a form-fitting manner in the tool supporting body. For positioning a seat is provided in the tool support body and corresponding thereto on the knife.

The US 3,207,195 shows a planer blade with a plurality of spaced square holes, which is fastened by appropriately trained carriage bolts.

The milling tool disclosed in US 4,614,463 is provided with knives having a round hole and a slot for attachment. By this configuration, manufacturing tolerances in the introduction of the openings in the Schneidermessem or the threaded holes in the tool body can be compensated.

The invention has the object of providing a cutting plate in such a way that it can be easily positioned and blocked.

To solve the problem, a generic cutting plate is characterized in that the first breakthrough to create a two-point bearing is polygonal in profile and the second breakthrough to create a Einpunktlagers in profile other than the first breakthrough is formed or both breakthroughs in profile polygonal and the profiles are twisted to each other.

The polygonal configuration of the first breakthrough makes it possible to form a two-point bearing for a cylindrical pin. The other breakthrough may be in the profile of arbitrary geometry. Important is only such a configuration that a one-point bearing is created for a cylindrical pin.

As a result of this design of the apertures, the cutting plate is uniquely positioned in its axial and radial position in the tool carrier body in that two cylindrical pins engage with clearance in the apertures. By moving the cutting plate, for example in the direction of the centrifugal forces, the positioning is then carried out by conditioning the profiles on the cylindrical pins. The cylindrical pins may be integrally formed with the tool support body, but they may also be formed by dowel pins or fitting screws.

In order to easily create the possibility for a one-point bearing, the second opening is preferably formed so that it has at least one parallel to the cutting edge of the cutting edge. It is particularly advantageous if the second opening is formed as a slot.

If the circle is chosen large enough relative to the cylindrical pin, the second aperture can also be circular or semicircular.

If both openings in profile polygonal and the profiles are rotated to each other, then preferably an opening with a longitudinal side of its profile extending parallel to the tool axis and the other breakthrough with a tip of its profile to the tool axis arranged pointing. By this configuration, the cutting plate can be formed as a reversible blade.

If the openings in the profile are substantially triangular in shape and the two profiles of the openings are rotated by 60 ° to each other, the positioning is further simplified. By moving the cutting plate in preferably Direction of action of the centrifugal forces creates a cylinder pin, on two sides of the triangular breakthrough and the other on one side of the triangular breakthrough. The mode of action then corresponds to a fixed and a floating bearing.

It can also be provided a plurality of openings, of which only two have a polygonal profile, when the clamping forces of the cutting plate (bolt clamping forces) to be evenly distributed. Preferably, then the two outer openings are designed as a polygon. The other breakthroughs are performed with play to the clamping screw, so as not to affect the unique positioning.

The corners of the polygon profile are preferably rounded to avoid notch stresses. In order to allow a defined abutment on the sides of the triangle, the corner radius of the triangles must be made smaller than the radius of the cylindrical pins. The position of the cylindrical pins in the tool carrier body determines the position of the cutting plate.

The cutting plate is preferably made of hard metal and in particular preferably sintered, wherein the polygonal openings remain unprocessed, in particular not ground.

Characterized in that the positioning takes place inside the cutting plate, the cutting plate can be performed cutting on all sides. The main cutting edge can be formed straight or profiled, whereby different profiles are possible within an insert.

The accuracy of the cutting profile can be significantly increased by the inventive design by the cutting plate is used for grinding in a device in which the cutting plate is positioned in the same manner as in the tool carrier body. On the accuracy of the breakthroughs then no special requirements to make, since the cutting plate is ground according to their installation position.

A machining tool, in particular a milling tool is characterized in that it is provided with a cutting plate as described above. For positioning the cutting plate in the tool carrier body preferably two in the position corresponding to the openings with polygonal profile cylindrical pins are provided whose diameter is smaller than the inner circle of the polygon.

The attachment of the cutting plate in the machining tool can be done directly via fitting screws, whereby the positioning and clamping takes place simultaneously or via dowels, which interact with the polygonal profile, and a clamping jaws. Positioning then takes place via the dowel pins and clamping over the jaws.

If the cutting plate is fixed by means of a support plate, only the support plate must be profiled according to the cutting profile become. The tool carrier is universally applicable.

For grinding the cutting plate, it is also positioned and clamped in a device, as it is then positioned and clamped in the machining tool. That is, the insert is pulled radially outward until it rests with the apertures on the two cylinder pins. By this measure, the displacement of the cutting plate - which occurs during operation by the influence of centrifugal force - thus anticipated and taken into account when grinding the cutting edge. Thus, later the circle diameter of the tool can not change and consequently also set no inaccuracies in the machining of the workpieces.

Figur 1 -

die schematische Ansicht auf eine erfindungsgemäße Schneidplatte;

Figur 2 -

die Seitenansicht der Schneidplatte gemäß Sichtpfeil II nach Figur 1;

Figur 3 -

die vergrößerte Ausschnittsdarstellung gemäß Sichtpfeil III nach Figur 1;

Figur 4 -

eine als Wendeplatte ausgebildete Schneidplatte;

Figur 5 -

die Seitenansicht der Wendeplatte gemäß Sichtpfeil V nach Figur 4;

Figuren 6a bis 6b -

ein Bearbeitungswerkzeug in Teildarstellung mit über Paßschrauben befestigter Schneidplatte;

Figuren 7 bis 7b -

ein Bearbeitungswerkzeug in Teildarstellung mit über Paßstifte positionierter und Spannbacken gespannter Schneidplatte;

Figur 8 -

eine Schneidplatte mit einer Mehrzahl von Durchbrüchen in einer Darstellung analog zu Figur 1;

Figur 9 -

die Seitenansicht der Schneidplatte gemäß Sichtpfeil IX nach Figur 8;

Figur 10 -

die vergrößerte Einzelheit gemäß Sichtpfeil X nach Figur 8;

Figur 11 -

die schematische Ansicht einer anderen Ausführungsform der Schneidplatte;

Figur 11a -

eine Variation der Schneidplatte gemäß Figur 11;

Figur 12 -

die schematische Ansicht einer nochmals anderen Ausführungsform der Schneidplatte;

Figur 12a -

eine Variation der Schneidplatte gemäß Figur 12;

Figur 13 -

die schematische Ansicht einer weiteren Ausführungsform der Schneidplatte;

Figur 13a -

eine Variation der Schneidplatte gemäß Figur 13;

With the help of a drawing, embodiments of the invention will be explained in more detail below. It shows:

FIG. 1 -

the schematic view of an insert according to the invention;

FIG. 2 -

the side view of the insert according to viewing arrow II of Figure 1;

FIG. 3 -

the enlarged detail view according to viewing arrow III of Figure 1;

FIG. 4 -

a cutting plate designed as a turning plate;

FIG. 5 -

the side view of the insert according to visual arrow V of Figure 4;

FIGS. 6a to 6b

a machining tool in partial view with attached via fitting screws cutting plate;

FIGS. 7 to 7b

a machining tool in partial view with over dowel pins positioned and clamping jaws cocked cutting plate;

FIG. 8 -

an insert with a plurality of openings in a representation analogous to Figure 1;

FIG. 9

the side view of the cutting plate according to viewing arrow IX of Figure 8;

FIG. 10 -

the enlarged detail according to visual arrow X of Figure 8;

FIG. 11

the schematic view of another embodiment of the cutting plate;

FIG. 11a -

a variation of the cutting plate according to Figure 11;

FIG. 12 -

the schematic view of yet another embodiment of the cutting plate;

FIG. 12a -

a variation of the cutting plate according to Figure 12;

FIG. 13

the schematic view of another embodiment of the cutting plate;

FIG. 13a

a variation of the cutting plate according to Figure 13;

Figure 1 to 3 show the inventive construction of a first embodiment of a cutting plate 1. On an axis parallel to the tool axis W axis 13 two triangular openings 2, 3 are introduced. The triangular profile 4 of the opening 2 is rotated relative to the profile 4 of the opening 3 by 60 °. As the figures show, the tip of the aperture 2 faces radially outward and the tip of the aperture 3 radially inward. The corners of the profile 4 are rounded. If the apertures 2, 3 have a different polygonal profile, care must be taken that they are so twisted that with respect to the mounting position in the tool of a breakthrough 2 radially inside a straight surface and the other opening 3 forms a corner. The axis 13 does not necessarily have to run parallel to the tool axis W. It is defined by the line connecting the centers of the apertures 2 and 3. If the insert 1 is inserted obliquely into the tool, the axis 13 is oblique to the tool axis W. If only one opening 2 is polygonal, a flexible arrangement of the fastening bolts (fitting screw 11 ) can be achieved in the tool when the other breakthrough 3 is formed, for example, as a slot.

The cutting plate 1 can be used as a turning plate with all-round cutting 7, 8, 8 ', 9 and, as Figure 4 shows, be formed with different profiles of the cutting.

To position the cutting plate 1 cylinder pins 5, 6 are provided, which can be formed either as a fitting screws 11 (Figures 6 to 6b) or dowel pins 12 (Figures 7 to 7b).

The diameter D of the cylindrical pins 5, 6 is smaller than the drawable in the triangular profile 4 inner circle (inscribed circle). By this embodiment, the cutting plate 1 relative to the pins 5, 6 movable. The radius r of the rounded corners is smaller than the radius D / 2 of the cylindrical pins 5, 6. To position the cutting plate 1, this is preferably pulled radially outward. In this case, the profile 4 of the opening 2 engages at a point A on the pin 5 and the profile 4 of the opening 3 at two points B, C on the pin 6 at. The positioning of the cutting plate 1 corresponds to a fixed bearing (B, C) and a floating bearing (A). After this positioning, the cutting plate 1 can be clamped in the tool carrier body 10.

As shown in Figure 6a to 6b, the positioning and clamping of the cutting plate 1 can be done simultaneously by using fitting screws 11. The snug fit of the fitting screws 11 then has the diameter D (Figure 3).

It is also possible to position the cutting insert 1 via dowel pins 12 (FIGS. 7) and to perform clamping by means of a clamping jaw 14, which is wedge-shaped and is pulled radially outward.

In particular, if fitting screws 11 are to be used, a plurality of perforations 2, 3, 23 may be provided in the cutting insert 1 '(FIG. 8) which may lie on an axis 13 and of which only the two outer faces 2, 3 are polygonal Profile 4 have. The remaining openings 23 are designed with clearance to the clamping screw then used.

FIGS. 11 to 13 a show three further embodiments of the cutting insert 1, including variations thereon. As can be seen, only one opening 2 in the profile is polygonal. The other breakthrough 3 may be of different geometry. If an edge 3 'running parallel to the cutting edge 7 is provided, this creates a contact edge for the journal or cylindrical pin 6, whereby only one line contact is established, so that a one-point bearing is provided in a simple manner. The polygon of the other opening 2 must be adjusted so that a tip extends transversely to the cutting edge 7.

As FIGS. 12 and 12a show, the other opening 3 in the profile can also be circular. It is important that the circle diameter relative to the diameter of the pin or cylinder pin 6 is chosen so that adjusts only a linear system. On both sides of the cutting plate 1 recesses 18, 19 may be introduced, which serve as a wear measure during regrinding. Regrinding of the cutting plate 1 is possible as long as the recess 18 or 19 of the front of the cutting plate 1 is visible. If this disappears, the cutting plate 1 must be replaced.

The insert blank, including the polygonal openings, can be produced by sintering. Only on the two wide surfaces 15, 16 and the at least one cutting edge 7, the cutting plate 1 must be ground. The abutment surfaces in the openings 2, 3 can be unprocessed, in particular not ground.

For grinding the cutting plate 1, this is just as well positioned and tensioned in a device not shown here, as they subsequently in the machining tool is positioned and stretched. Regardless of the exact position of the apertures 2, 3, the cutting plate 1 is then ground directly in accordance with their later seat in the machining tool, whereby the accuracy of the profile 4 of the apertures 2, 3 only low requirement must be made, which not only reduces the production costs, but also the replacement of a cutting plate 1 much easier.

Within predetermined limits, the cutting plate 1 can be resharpened on the chip surface or in the profile. The position of the cylindrical pins 5, 6 determines the position of the cutting plate 1 in the tool carrier body 10 and thus also the circle diameter.

LIST OF REFERENCE NUMBERS

1

cutting board

1'

cutting board

2

breakthrough

2 '

edge

3

breakthrough

3 '

edge

4

profile

5

Pin / cylinder pin

6

Pin / cylinder pin

7

cutting edge

8th

cutting edge

8th'

cutting edge

9

cutting edge

10

Tool support body

11

Dowel screw / cylindrical pin

12

Dowel / cylinder pin

13

axis

14

jaws

15

wide area

16

wide area

17

support plate

18

deepening

19

deepening

23

breakthrough

A

contact point

B

contact point

C

contact point

D

diameter

D / 2

radius

r

radius

W

tool axis

Claims (15)

1. Cutting insert for a cutting tool, in particular a milling tool, having at least one cutting edge (7) and at least one first aperture (2) and one second aperture (3) at a distance therefrom for positioning and/or fastening the cutting insert (1) in the tool-carrying body (10), characterized in that the first aperture (3), for creating a two-point bearing (B, C), is of polygonal design in profile (4) and the second aperture (2), for creating a single-point bearing (A), is of different design in profile from the first aperture (3), or both apertures (2, 3) are of polygonal design in profile (4) and the profiles (4) are rotated relative to one another.
2. Cutting insert according to Claim 1, characterized in that the second aperture (3; 2) has at least one edge (3', 2') running parallel to an axis (13).
3. Cutting insert according to Claim 1, characterized in that the second aperture (3) is of circular design.
4. Cutting insert according to Claim 2, characterized in that the second aperture (3) is designed as an elongated hole.
5. Cutting insert according to Claim 2, characterized in that the second aperture (2) is of semicircular design.
6. Cutting insert according to Claim 1, characterized in that the second aperture (3) is arranged with a longitudinal side of its profile (4) parallel to the tool axis W, and the first aperture (2) is arranged with a tip of its profile (4) pointing towards the tool axis W.
7. Cutting insert according to Claim 1, characterized in that the apertures (2, 3) are of essentially triangular design in profile (4), and in that the profiles (4) are rotated by at least 60° relative to one another.
8. Cutting insert according to Claims 1 or 6 or 7, characterized in that a plurality of apertures (2, 3, 23) are provided, of which only two (2, 3) have a polygonal profile (4).
9. Cutting insert according to one of the preceding claims, characterized in that the apertures (2, 3) are unmachined, in particular they are not ground.
10. Cutting insert according to one of Claims 6 to 9, characterized in that the corners of the polygonal profile (4) are rounded off.
11. Cutting insert according to one or more of the preceding claims, characterized in that cutting edges (7, 8, 8', 9) are provided on all four sides.
12. Cutting tool, in particular a milling tool, characterized by a cutting insert (1) according to one or more of Claims 1 to 11.
13. Cutting tool according to Claim 12, characterized in that two straight pins (5, 6; 11, 12) corresponding in position to the apertures (2, 3) having a polygonal profile (4) are provided or can be provided in order to position the cutting insert (1) in the tool carrier (10), the diameter (D) of which straight pins (5, 6; 11, 12) is smaller than the inner circle (inscribed circle) which can be drawn inside the polygon.
14. Cutting tool according to Claim 12 or 13, the cutting insert (1) being fastened in the tool-carrying body (10) via a supporting plate (17), characterized in that only the supporting plate (17) is profiled in accordance with the cutting edge (7) of the cutting insert (1).
15. Cutting tool according to Claim 12, characterized in that the radius (r) of the rounded-off corners of the profile (4) is smaller than the radius D/2 of the straight pins (5, 6; 11, 12).

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