WO2008037320A1

WO2008037320A1 - Abrasive disc and abrasive wheel comprising the latter

Info

Publication number: WO2008037320A1
Application number: PCT/EP2007/007031
Authority: WO
Inventors: Georg Klug
Original assignee: Lukas-Erzett Vereinigte Schleif- Und Fräswerkzeugfabriken Gmbh & Co. Kg
Priority date: 2006-09-25
Filing date: 2007-08-09
Publication date: 2008-04-03
Also published as: DE102006045552B3

Abstract

An abrasive disc (1), in particular for abrasive wheels (15) which can be driven in a rotating manner, comprising an outer edge (2) and an inner edge (3), which merge one into the other at a first point of intersection Si, wherein the inner edge (3) has, at least over part of its extent, a concave portion (7), which is formed such that it is congruent with a convex portion (16) of the outer edge (2), wherein the convex portion (16) of the outer edge (2) extends from the first point of intersection Si over a part of the outer edge (2) and wherein the concave portion (7) of the inner edge and the convex portion (16) of the outer edge (2) are arranged point-symmetrically in relation to each other.

Description

Abrasive blade and grinding wheel containing it

description

The invention relates to a grinding blade, in particular for rotating drivable grinding wheels and a grinding wheel with such grinding blades.

Abrasive wheels, which have a plurality of abrasive flaps are placed on a prime mover to z. B. workpieces surface grinding process. Such grinding wheels and grinding blades are known in the prior art in various embodiments.

EP 1 142 673 B1 discloses abrasive lamellae having two mutually parallel edges and between these a convex and a concave third and fourth edge. The abrasive lamellae are applied like a tile overlapping on an annular support portion of a carrier.

The convex and concave edges are designed as circular arcs and have the same radius, the centers of the circular arcs are arranged offset from one another in a line. Thus, the grinding blades can be continuously cut from an endless belt, with no or only a small waste produced.

DE 200 18 756 U1 shows elements for a grinding or polishing tool, which are of similar construction and can be cut off continuously from an endless belt. In this case, however, the individual elements are not arranged in the form of a roof tile overlapping on a support, but put together to form a blank. The object of the present invention is to propose a grinding blade and a grinding wheel, in the production of which a minimal waste is obtained.

According to the invention, the object is achieved by a grinding lamella, in particular for grinding wheels which can be driven in rotation, which comprise an outer edge and an inner edge, which merge into one another at a first intersection, the inner edge having a concave section over at least part of its extent is formed congruent with a convex portion of the outer edge, wherein the convex portion of the outer edge extending from the first intersection over a portion of the outer edge and wherein the concave portion of the inner edge and the convex portion of the outer edge are arranged point-symmetrical to each other.

Due to the point-symmetrical design and arrangement of the convex portion and the concave portion, two grinding lamellae can be cut out of a band material such that the two grinding lamellae intermesh with each other by 180 degrees, with the concave portion of the inner edge extending along the convex portion of the outer edge. Thus, the grinding lamellae can be interleaved out of a strip material so that only a small amount of waste is produced.

The abrasive blade also has a connecting edge so that the outer edge, the inner edge and the connecting edge define the abrasive blade. In this case, the inner edge merges into the outer edge in a second intersection point into the connecting edge and the connecting edge at a third intersection point.

It is preferably provided that the outer edge has a circular-arc-shaped section with a first center, that the arcuate section merges into a transition section of greater curvature and that the outer edge merges with the transition section in the first intersection into the inner edge.

It can be provided that the convex portion of the outer edge, starting from the first intersection over the transition region and a part of the circular arc portion of the outer edge extends.

Preferably, provision must accordingly be made for the concave section of the inner edge to have a circular-arc-shaped section with a second center, which merges into a transition section of greater curvature. Here, the radius of the circular arc-shaped portion of the inner edge is identical to the radius of the circular arc-shaped portion of the outer edge.

By the transition portions of greater curvature ensures that the abrasive blade has a variable radial width with respect to the first center. As a result, when the individual grinding lamellae are stacked in such a way that the circular arcuate portions of the outer edges together form an outer contour of the grinding wheels, a stepped inner area at the inner edges, so that each individual grinding lamella over a large angular range of the inner edge around the first center z. B. can be glued to a carrier of a grinding wheel.

Here, the transition portion of the outer edge and the transition portion of the inner edge may be designed spirally.

In order to ensure a continuous transition between the circular arc-shaped sections and the spiral-shaped sections, it is provided that the pole of the spiral-shaped transition section of the outer edge is identical to the second center point and the pole of the spiral-shaped transition section of the inner edge is identical to the first center point.

In order to ensure a simple geometry of the grinding lamella, it can be provided that the inner edge, starting from the first intersection, has an intermediate section which merges into the concave section of the inner edge.

Preferably, the abrasive slats are cut out of a continuous band having a defined width by means of laser cutting. Furthermore, the object is achieved by a grinding wheel with a plate-shaped carrier, which is rotatably driven about an axis, and is provided with a plurality of aforementioned grinding lamellae, which are partially attached overlapping on the carrier solved.

In this case, the individual grinding lamellae are arranged such that the first center points lie on one another and the grinding lamellae are arranged at an angle to each other with respect to the first center.

Thus, the outer contour of the grinding wheel is formed by the arcuate portions of the outer edges of the grinding blades.

Preferably, the carrier of the grinding blade is plate-shaped, wherein on this a ring of mutually partially overlapping grinding blades is arranged. The abrasive flaps can be glued to the support element by a resin. The plate-shaped carrier may consist of a metal, a resin-bonded glass fiber fabric, a fiber material, a plastic material or another solid or hard, tough as possible non-splintering material. Material combinations are also possible, e.g. for partially reinforcing the carrier in the area around a central opening, which serves to engage a Einspannzapfens a drive machine on which the grinding wheel is fixed. It is also possible to make a grinding wheel without a separate carrier. In this case, as already described, the individual grinding lamellae are arranged partially overlapping around the first superimposed centers and bonded together by means of a resin, the resin layer itself, together with the grinding lamellae, giving rise to sufficient rigidity of the grinding wheel.

A preferred embodiment will be explained in more detail with reference to the drawings.

Herein shows

Figure 1 is a plan view of a back side of a grinding blade according to the invention; Figure 2 is a plan view of a front side of a grinding wheel according to the invention;

Figure 3 is a plan view of a back side of a grinding wheel according to Figure 2 and

4 shows a pattern for a grinding blade according to the invention.

Figure 1 shows a grinding blade 1, which is bounded by an outer edge 2, an inner edge 3 and a connecting edge 4. Here, the outer edge 2 is in a first intersection Si in the inner edge 3, the inner edge 3 in a second intersection S ₂ in the connecting edge 4 and the connecting edge 4 in a third intersection S ₃ in the outer edge 2 via.

The outer edge 2 has over a part of its extension a convex portion 16 which begins at the first intersection Si and ends at a first point Pi of the outer edge 2. The inner edge 3 has over a part of its extension a concave portion 7, which begins at a second point P _{2 of} the inner edge 3 and ends at the second intersection S ₂ . The concave portion 7 of the inner edge 3 has, starting from the second point P _{2 on the} same course, as the convex portion 16 starting from the first intersection Si. For this purpose, the convex portion 16 and the concave portion 7 are arranged point symmetrical about a symmetry point Sp.

Due to the point-symmetrical design and arrangement of the convex portion 16 and the concave portion 7, two abrasive slats 1 can be cut out of a strip material such that the two abrasive slats 1 rotated by 180 ° to each other in mesh, wherein the convex portion 16 of the outer edge 2 along the concave Section 7 of the inner edge 3 runs. Thus, the grinding lamellae 1 can be nested in such a way cut out of a strip material that only a small waste produced.

The outer edge 2 has a circular arc-shaped section 5 with a center Mi on, which extends over the angle range α from a first beam Ri to a second beam R ₂ . The circular-arc-shaped section 5 is adjoined by a transition section 6 whose curvature is greater than that of the circular arc-shaped section 5 of the outer edge 2, so that its radial distance to the first center M ₁ decreases continuously. The transition section 6 ends in the first intersection Si ₁ in which the outer edge 2 merges into the inner edge 3.

The inner edge 3 has a circular arc-shaped portion 8, which starts from the second intersection S ₂ and has a second center M ₂ . The second center M ₂ is offset from the first center Mi. The circular arc-shaped portion 8 of the inner edge 3 extends from a first beam T ₁ over an angular range ß to a second beam r ₂ The radius of the circular arc-shaped portion 8 of the inner edge 3 is identical to the radius of the arcuate portion 5 of the outer edge. 2

At the circular arc-shaped portion 8 of the inner edge 3, a transition section 9 connects, whose curvature is greater than that of the circular arc-shaped portion 8 of the inner edge 3, so that its radial distance to the second center M ₂ decreases continuously. This transition section 9 is formed corresponding to the transition section 6 of the outer edge 2. The transition section 6 of the outer edge 2 is formed spirally, wherein the pole is formed by the second center M ₂ . The spiral transition section 6 extends through an angle γ from a beam R 'to the beam R ".The transition section 9 of the inner edge 3 is also helical, the pole being represented by the first center Mi. The spiral transition section 9 extends over the angle δ from the beam r 'to the beam r ". The rays Ri. R2, r \ r "and r '" start from the first center M ₁ and the rays n, r _2, R' and R "start from the second center M ₂ , the rays r ', R ¹ Thus, a part of the contour of the circular arc portion 8 and the spiral transition portion 9 of the inner edge 3 corresponds to a part of the contour of the circular arc portion 5 and the spiral transition portion 6 of the outer edge 2. This makes it possible that two slats 1 are interleaved can. Here are the spiral transition sections 6 and 9 and a part of the circular arc-shaped portion 5 of the outer edge 2 and the circular arc-shaped portion 8 of the inner edge 3 to each other. The rays R ₂ , R ', r ₂ and r ¹ lie on a common line containing the two centers Mi and M ₂ .

The transition sections 6, 9 can also be realized differently than spirally. It may be e.g. to act arcuate sections whose center are offset from the center of the adjacent circular arc-shaped sections 5, 8. In principle, even edges are conceivable.

The inner edge 3 further has, following the spiral transition section 9, an intermediate section 10, which extends over the angular region ε. The intermediate section 10 is formed spirally and continues the spiral shape of the transition section 9. The pole is therefore represented by the center M ₁ . However, the intermediate section 10 can also be different, for. B. circular arc, be designed.

FIG. 2 shows a top view of a grinding wheel 15 with six grinding lamellae 1 according to the invention according to FIG. 1. The grinding lamellae 1 are arranged relative to each other such that their first centers Mi lie one on top of the other and are arranged uniformly angularly offset from each other. Here, the circular arc-shaped sections 5 of the outer edge 2 together form an outer contour 11 of the grinding wheel.

The grinding blades 1 are glued on a support 12, which has a central bore 13 for fixing the grinding wheels 15 to a tool.

FIG. 3 shows a rear view of the grinding wheel according to FIG. 2 without a carrier. It can be seen here that due to the spiral-shaped transitional sections on an inner circumference 14 of the grinding wheel 15, a step-shaped area results. One of the grinding lamellae 1 is highlighted in black, the black surface representing that surface which can be glued on a support of the grinding wheel 15. It can be seen that the grinding blade 1 can be glued over its entire length of the inner edge 3 with a carrier, so that a particularly good grip of the grinding blade 1 results on the support.

FIG. 4 shows a cutting pattern for producing abrasive flaps according to the invention. It can be seen how the grinding lamellae 1 are interleaved and lie in the course matching parts of the edges together. If this pattern is transferred to a continuous belt, thus the blending can be kept extremely low, although the shape of the grinding blade 1 is made complex.

LIST OF REFERENCE NUMBERS

1 grinding lamella

2 outer edge

3 inner edge

4 connecting edge

5 arcuate portion of the outer edge

6 transition section of the outer edge

7 concave section

8 arcuate portion of the inner edge

9 transition section of the inner edge

10 transitional area

11 outer contour

12 carriers

13 hole

14 inner circumference

15 grinding wheel

16 convex section

α angle ß angle

Y angle δ angle ε angle

Ri beam

R ₂ beam

R 'beam

R "beam n beam

X ₂ ray r 'ray r "ray r"' ray

Mi first center point (pole of the transition section of the inner edge)

M2 second center point (pole of the transition section of the outer edge)

Pi first point

P2 second point

Sp symmetry point

51 intersection

5 ₂ intersection

Claims

claims

1. Abrasive blade (1), in particular for rotationally drivable grinding wheels (15), comprising an outer edge (2) and an inner edge (3) which merge into each other in a first intersection (Si), wherein the inner edge (3) at least over a part its extension has a concave portion (7) congruent with a convex portion (16) of the outer edge (2) is formed, wherein the convex portion (16) of the outer edge (2) starting from the first intersection (Si) over a part the outer edge (2) and wherein the concave portion (7) of the inner edge and the convex portion (16) of the outer edge (2) are arranged point-symmetrical to one another.

2. Abrasive blade according to claim 1,

characterized,

in that the grinding lamella further has a connecting edge (4) and in that the outer edge (2), the inner edge (3) and the connecting edge (4) form the

Limiting grinding lamella.

3. Abrasive blade according to claim 2, characterized,

the inner edge (3) merges into the connecting edge (4) at a second point of intersection (S ₂ ).

4. Abrasive blade according to one of claims 2 or 3,

characterized,

the connecting edge (4) merges into the outer edge (2) at a third point of intersection (S ₃ ).

5. Abrasive blade according to one of the preceding claims,

characterized,

in that the outer edge (2) has an arcuate section (5) with a first center (Mi), that the arcuate section (5) merges into a transition section (6) of greater curvature, and that the outer edge (2) merges with the transition section (6). in the first intersection (Si) in the concave inner edge (3) passes.

6. Abrasive blade according to claim 5,

characterized,

that the convex portion (16) of the outer edge (2) extends from the first intersection (Si) over the transition region and a part of the circular arc section (5) of the outer edge (2).

7. Abrasive blade according to one of claims 5 or 6, characterized,

in that the concave portion (7) of the inner edge (3) has an arcuate section (8) with a second center (M ₂ ) which merges into a transition section (9) of greater curvature.

8. Abrasive blade according to claim 7,

characterized,

in that the transition section (6) of the outer edge (2) and the transition section (9) of the inner edge (3) are spirally shaped.

9. Abrasive blade according to claim 8,

characterized,

in that the pole of the spiral transition section (6) of the outer edge (2) is identical to the second center point (M ₂ ) and that the pole of the spiral transition section (9) of the inner edge (3) is identical to the first center point (M ₁ ).

10. Abrasive blade according to one of the preceding claims,

characterized,

the inner edge (3), starting from the first intersection (S ₁ ), has an intermediate section (10) which merges into the concave section (7) of the inner edge (3).

11. Abrasive blade according to one of the preceding claims,

characterized, in that the grinding lamella (1) is cut out of a continuous band with a defined width by means of laser cutting.

12. Grinding wheel (15) with a plate-shaped carrier (12) which is rotationally drivable about an axis, and with a plurality of grinding blades (1) according to one of the preceding claims, which are partially overlapping, mounted on the carrier (12) ,

13. Grinding wheel according to claim 12,

characterized,

in that the outer contour (11) of the grinding wheel (15) is formed by circular-arc-shaped sections (5) of the outer edges (2) of the grinding lamellae (1).