WO2012034785A1

WO2012034785A1 - Grinding wheel

Info

Publication number: WO2012034785A1
Application number: PCT/EP2011/063468
Authority: WO
Inventors: Roman Zaech; Peter Eggenberger
Original assignee: Robert Bosch Gmbh
Priority date: 2010-09-13
Filing date: 2011-08-04
Publication date: 2012-03-22
Also published as: US20130344783A1; EP2616217A1; DE202010012502U1

Abstract

The invention relates to a circular grinding wheel (1) with a centre point (M), comprising a multiplicity of extraction holes (2), in particular circular extraction holes, wherein the centre point of each extraction hole (2) is arranged at the point of intersection of a radial line (S₁, S₂,...) extending from the centre point (M) of the grinding wheel (1) with a circle of holes (K₁, K₂,...) that is arranged concentrically with respect to the centre point (M) and has a radius (r₁, r₂,...). At least one of the radial lines (S₁, S₂,...) is a single-hole radial line (S_i1, S_i2,...), on which the centre point of only a single extraction hole (2) is arranged. The centre points of all the extraction holes (2) that are arranged on a single-hole radial line (S_i1, S_i2,...) lie substantially on a common single-hole circle (K_i) having a radius (r_i). Each radial line (S_j) comprises the centre point of an extraction hole (2) on at least one radius (r_j) on which the two radial lines (S_j-1, S_j+1) that are adjacent to this radial line (S_j) in the circumferential direction have no centre point of an extraction hole (2).

Description

description

title

grinding wheel

Background of the Invention The present invention relates to a circular grinding wheel having a plurality of suction holes according to the preamble of claim 1. Such grinding wheels are also known as "multi-hole grinding wheels".

When machining a workpiece with a rotating grinding wheel, grinding dust is generated which would clog the grinding wheel without further measures and would therefore lead to very short service lives. The grinding wheel must therefore be replaced often, which is extremely laborious and uneconomical.

To remedy this problem, grinding wheel extraction holes are known for a long time, which penetrate the grinding surface. Through these suction holes through the grinding dust can be removed. These grinding wheels can be attached to sanding plates, which also identify corresponding suction holes. This removal is particularly effective when the sanding dust is actively sucked by generating a negative pressure in the sanding pad.

Such generic grinding wheels are known for example from EP 1 977 858 AI. The grinding wheels disclosed there have a plurality of suction holes, through which the dust can be sucked. Due to the special arrangement of the suction holes (the so-called "hole pattern"), it is possible to suck off the grinding dust almost independently of the relative rotational position between the grinding wheel and the sanding pad Further generic grinding wheels with other hole patterns are known, for example, from WO 2008/042775 A1, where a Arrangement of the suction holes at the vertices of a Triangle grid is described, or from EP 781 629 AI, where the suction holes are arranged at the vertices of a square grid.

The hole pattern should simultaneously meet a variety of criteria. On the one hand, the total area of all suction holes should be large enough for suction to take place at all. On the other hand, the total area of all suction holes may not be too large, so that sufficient abrasive grain can be arranged on the remaining grinding surface to ensure material removal at all.

In addition, it is desirable for practical reasons that the grinding wheel can be attached to as many different grinding plates as possible, the hole pattern of which can vary greatly from provider to provider. There should always be sufficient overlap between the extraction holes of the grinding wheel and those of the sanding plate. In addition, it is desirable that the suction power be substantially independent of the relative rotational position between the grinding wheel and the sanding pad; the user no longer has to laboriously bring the suction holes of the grinding wheel and grinding disc into line. Finally, the distance between the holes on the one hand should not be too large, otherwise no uniform suction is possible. On the other hand, the distance between the suction holes must not be too small, since the grinding wheel could otherwise lose its stability and could break or tear, for example, at the webs between the suction holes.

It is therefore an object of the present invention to provide a grinding wheel with which the best possible compromise between the above-mentioned effects can be achieved. In particular, so the highest possible and uniform extraction should be possible, and indeed largely independent of the hole pattern of the grinding disc used and the relative rotational position between the grinding wheel and grinding disc. Disclosure of Invention Advantages of the Invention These and other objects are achieved by a circular grinding wheel having a center and a plurality of, in particular, circular suction holes. The grinding wheel may have in its center a particular circular attachment opening. In this case, the center is to be understood only as an imaginary reference point, from which the geometric arrangement of the suction holes described below is defined. In any case, the center of the grinding wheel is understood to be the geometric center of the circular circumference of the grinding wheel.

Each suction hole is assigned its own center. This center is also an imaginary reference point of the grinding wheel, which corresponds to the geometric center of gravity of the suction hole. For example, if the suction hole is circular, its center coincides with the geometric center of the circle that forms the edge of the suction hole. The center of each suction hole on the one hand defines a beam emanating from the center of the grinding wheel, on which the center of the suction hole lies. On the other hand, the center of the suction hole defines a circle of holes concentric with the center of the grinding wheel and on which lies the center of the suction hole. The center of the suction hole is then on the intersection of the beam with the bolt circle.

According to the invention, the arrangement of the suction holes is characterized by the following properties: First, only the center of a single suction hole is arranged on at least one of the rays emanating from the center. Such a beam is referred to here and below as a single-hole beam.

Furthermore, the centers of all suction holes, which are arranged on a single-hole jet, should lie substantially on a common single-hole circle with the same radius. Consequently, they are all substantially the same distance from the center of the grinding wheel. The phrase "essentially" means in that the distances of the centers of the suction surface from the center of the grinding wheel differ from each other by at most half a diameter of the individual suction holes. The above characteristic does not exclude that on the single-hole circle are also the centers of suction holes, which are not arranged on a single-hole jet. At least one of the suction holes on the single-hole circle must lie on a single-hole jet at the same time.

Finally, each beam should have the center of a suction hole at at least one radius, at which radius the two beams adjacent to this beam in the circumferential direction do not have a center point of a suction hole.

The combination of these features leads to a particularly good compromise between suction and uniformity, independence from the hole pattern of the sanding pad and the positioning and stability of the Schleischeibe. The arrangement of the suction holes, which lie both on a single-hole jet and on the single-hole circle, ensures, for example, that the suction holes are circumferentially offset from each other. As a result, a relatively uniform arrangement of the suction holes is achieved without the suction holes must be too close together to reduce the stability of the grinding wheel. In addition, it has been found that the removal rate (ie the amount of material removed from a machined surface during grinding per time) can be significantly increased by such a hole pattern. In addition, it was found in many experiments that the surface roughness of the machined surface remained virtually unchanged.

In preferred embodiments, the number of circles whose radius is smaller than the radius of the one-hole circle, in the range of 2 to 5. In other words, the one-hole circle is the third smallest, fourth smallest, fifth smallest or sixth smallest radius, are arranged on the suction holes. Preferably, the number of circles whose radius is smaller than the radius of the single-hole circle, 3 or 4. The more hole circles are within the single-hole circle, the farther out is the single-hole circle. In these outer areas of the grinding surface of the angular offset described above is particularly favorable. Each jet having at least one center of a suction hole can be assigned to a jet type. By definition, this type of jet indicates the totality of the radii at which the center of a suction hole is arranged on this jet. For example, a jet type could be characterized by having a first hole at the smallest radius, a second hole at the third smallest radius, and a third hole at the fifth smallest radius.

The grinding wheel preferably has at most 5, preferably at most 4, more preferably at most 3, particularly preferably exactly 3 different types of jet. One of these beam types is always the beam type of single-hole beams. Since, according to the invention, the centers of all the suction holes arranged on a single-hole jet lie substantially on a common single-hole circle, the grinding disk contains only a single single-hole jet type. The other types of jet always contain at least the centers of two suction holes as a result of the properties of the invention.

Preferably, at most 6, preferably at most 4, more preferably at most 3 centers of suction holes are arranged on each jet. In this way it can be ensured that the distances of the suction holes are large enough from one another to ensure the stability of the grinding wheel.

Also preferably, the center of at least 3 suction holes are arranged on each beam which is not a single-hole jet. In other words, there are no jet types that contain exactly two suction holes. This leads to the grinding wheel containing a sufficient number of suction holes.

It has proved to be advantageous if the number of all suction holes is in the range from 20 to 100, preferably from 30 to 80, particularly preferably from 40 to 64. This provides a good compromise between high and uniform suction and simultaneous stability of the grinding wheel.

The number of jets containing at least one center of a suction hole is advantageously in the range of 10 to 50, preferably between 20 and 30 and is particularly preferred 24. A smaller number of jets would mean an accumulation of the suction holes in certain areas of the grinding wheel, which would lead to uneven suction. A larger number of jets would result in a high density of the suction openings, which would reduce the stability of the grinding wheel. Also preferably, the number of hole circles, on which the center of at least one suction hole is arranged, in the range of 3 to 10, preferably from 4 to 8, particularly preferably from 4 to 6. Too small a number of bolt circles would lead to an uneven suction along lead the radial direction. Too large a number, however, would entail a loss of stability in the radial direction.

Preferably, the radii of the hole circles are distributed substantially uniformly over the radius of the entire grinding wheel. The smallest radius of a lock circle can be between 15% and 35%, preferably between 20% and 30% of the radius of the grinding wheel. The largest radius of a lock circle can be between 70% and 90%, preferably between 75% and 85% of the radius of the grinding wheel. To characterize the uniform distribution of the radii, the average absolute deviation of the radial distances of each two adjacent hole circles can be used. Preferably, this mean absolute deviation is less than 30%, preferably less than 15% of the mean radial distance between two adjacent bolt holes.

The average number of suction holes whose centers lie on a jet is preferably in the range from 1.2 to 3, preferably from 1.4 to 2.85, particularly preferably from 1.6 to 2.7. A smaller average number would result in nonuniform suction along the radial direction, while a larger average number would decrease the stability of the grinding wheel.

Also preferably, the average number of suction holes, the centers of which lie on a circle of holes, is preferably in the range from 6 to 20, preferably from 8 to 15, particularly preferably from 10 to 12.5. A smaller average number would result in non-uniform suction along the circumferential direction, while a larger average number would decrease the stability of the grinding wheel. As explained above, the ratio of the total area of all suction holes to the total surface of the grinding wheel determines, on the one hand, the effect of the suction and, on the other hand, the stability of the grinding wheel. Advantageously, this ratio is in the range from 2% to 20%, preferably from 6% to 12%, more preferably from 4% to 7%. The total area of the grinding wheel includes both the actual grinding surface on which the abrasive grains are applied and the total area of all the suction holes. If the grinding wheel has a central attachment opening, however, its area is not added to the total area of the grinding wheel. Thus, if the grinding wheel has a diameter D and if it has a central, circular attachment opening with a diameter b, then the total area of the grinding wheel is calculated by

- (D ² - b ² ).

4

In advantageous embodiments, at least 80%, preferably at least 90%, particularly preferably all suction holes are circular and have a diameter ranging from 3 mm to 6 mm, preferably from 3.5 mm to 4.5 mm, particularly preferably from 4 mm to 5 mm. With such diameters, a particularly good suction could be achieved. Preferably, the centers of at least 8 suction holes are arranged on each bolt circle, preferably of exactly 8 suction holes or exactly 16 suction holes.

Advantageously, the suction holes are arranged uniformly in the circumferential direction on each bolt circle. If a bolt circle contains, for example, 8 suction holes, then two suction holes arranged on the hole circle and adjacent to one another in the circumferential direction are arranged at an angular distance of 45 ° from one another.

It is advantageous if the arrangement of the suction holes is not substantially translucent symmetrical. An arrangement is referred to as translationally symmetric if it is converted into itself by a linear displacement. The phrase "substantially" means that the arrangement can not be completely self-transposed due to the finite number of suction holes in the peripheral areas of the grinding wheel due to such translation For example, the arrangement at the vertices of a square grid (as in EP 781 629 AI) or at the vertices of a triangular grid (as in WO 2008/042775 AI). The grinding wheel may contain any known backing, for example paper or vulcanized fiber. The suction holes can be produced for example by punching in the documents. The abrasive grain may be any known per se, for example alumina, silicon carbide or silicon nitride. The abrasive grains may have conventional grain sizes, eg P80, P180, P240 or P400. The abrasive grain can be fixed to the substrate with a binder which is also known per se.

Alternatively or in addition to a central attachment opening, the grinding wheel may have on its back side (i.e., on the side facing away from the abrasive grain) further attachment means for attachment to a sanding pad. For example, these may be loops and / or hooks of a loop-hook connection, ie a Velcro connection. It is also conceivable that the fastening means are formed by a coating with a pressure-sensitive adhesive. The following Table 1 gives particularly preferred combinations of parameters describing the arrangement of the suction holes:

Parameter 1 2 3 4 5 6

Diameter of the grinding wheel in 150 150 150 125 150 150 mm

Diameter of the suction holes in 4 4.5 5 4.5 4 4.5 mm

Number of suction holes 56 56 56 40 64 64

Number of bolt circles 5 5 5 4 6 6

Number of suction holes on 8 8 8 8 8 8

Hole circles 8 8 8 8 8 8

16 16 16 16 8 8

8 8 8 8 16 16

16 16 16 8 8

16 16 Number of bolt circles whose 3 3 3 3 4 4 radius is smaller than the radius

of the single-hole circle

Number of jet types 3 3 3 3 3 3

Number of suction holes on the 1; 1; 3 1; 1; 3 1; 1; 3 1; 1; 3 1; 3; 4 1; 3; 4 types of jet

Table 1

Description of the drawings

In the following the invention will be explained in more detail with reference to six concrete embodiments and figures, which embody the above variants. Showing:

Figure 1: a first embodiment of an inventive

Grinding wheel with 56 suction holes with a diameter of 4 mm;

Figure 2: a second embodiment of an inventive

Grinding wheel with 56 suction holes with a diameter of 4.5 mm;

Figure 3: a third embodiment of an inventive

Grinding wheel with 56 suction holes with a diameter of 5 mm;

Figure 4: a fourth embodiment of an inventive

Grinding wheel with 40 suction holes with a diameter of 4.5 mm;

Figure 5: a fifth embodiment of an inventive

Grinding wheel with 64 suction holes with a diameter of 4 mm;

Figure 6: a sixth embodiment of an inventive

Grinding wheel with 64 suction holes with a diameter of 4.5 mm. Description of the embodiments

The first embodiment shown in Figure 1 shows a circular grinding wheel 1 with a diameter D = 150 mm. In the center of the grinding wheel 1, a circular attachment opening 3 with a diameter of b = 16 mm is arranged, by means of which the grinding wheel 1 can be connected in a manner known per se to a sanding pad (not illustrated here). The grinding wheel 1 includes an imaginary center M, which represents the geometric center of the circular outer periphery 4 of the grinding wheel 1.

The grinding wheel 1 contains a total of n _L = 56 circular suction holes 2 with a diameter of 4 mm. The center point of each suction hole 2 is on one of n _s = 24 emanating from the midpoint M rays as well as on one of n _K = 5 hole circles Ki, K ₅ with associated radii ri = 18.5 mm, r ₂ = 27.5 mm, r ₃ = 40 mm, r ₄ = 50 mm and r ₅ = 60 mm arranged. On the hole circles Ki, K _5, the center points of n are _L i = 8, n _L2 = 8, n = 16 _L 3, n _L4 = 8 and n = 16 _L 5 exhaust holes 2 are arranged. On each of the hole circles Ki, ..., K5, the suction holes 2 are arranged uniformly in each case in the circumferential direction: on the hole circles Ki, K ₂ and K ₄ , the suction holes 2 are thus arranged at an angular distance of 45 ° from each other, while the suction holes 2 on the hole circles K ₃ and K ₅ are arranged at an angular distance of 22.5 ° from each other. The eight beams S ₂ , S ₅ , S ₈ , Sn, S _i4 , Si ₇ , S ₂₀ and S ₂₃ each contain only the center of a single suction hole 2. These beams are therefore referred to as single-hole beams. The total of 8 suction holes 2 on the single-hole beams are all on the same bolt circle K ₄ and consequently all have the same distance from the center M of the grinding wheel 1. The bolt circle is therefore referred to as a single-hole circle. The three circle of holes Ki, K ₂ and K ₃ thus have smaller radii than the one-hole circle K ₄ .

As can also be seen from FIG. 1, each jet S 1, S _{24 has} the center of a suction hole 2 at at least one radius, at which radius the two beams adjacent to this jet in the circumferential direction do not have a center point of a suction hole 2. For example, the jet Si at the radius R _{2 contains} the center of a suction hole 2, which therefore lies on the bolt circle K ₂ . The circumferentially adjacent beams S ₂ and S ₂₄ included in this Distance r _2, however, no suction hole 2. The jet S ₂ contains the center of a suction hole 2 at the radius r ₄ , but the circumferentially adjacent beams Si and S ₃ are not. This results in that the suction holes 2 are angularly offset from each other. Thus, the suction holes 2 are arranged on the one hand relatively uniform and allow a relatively uniform suction. On the other hand, the distances between the suction holes 2 are large enough to prevent cracking or breaking of the webs between adjacent suction holes 2.

The grinding wheel 1 contains exactly three types of jet Ti, T ₂ and T ₃ : The jet type Ti contains only a single suction hole 2 at the radius r ₄ and therefore forms a single-hole jet. The jet type T ₂ contains an exhaust hole ₂ at the radii r ₂ , r ₃ and r ₅ , while the jet type T ₃ at the radii ri, r ₃ and r _{5 contains} an exhaust hole 2. Each of the beams Si, S ₂ ,... Or each of the jet types Ti, T ₂ , T ₃ thus contains either exactly one or exactly three centers of suction holes 2. The beam types are in the circumferential direction U in the order T ₂ , Ti, T ₃ , wherein this order is repeated eight times over the entire angular range of 360 °. The angle between T ₂ and Ti and between T ₂ and Ti is 11.25 °, while between Ti and T ₃ is 22.5 °. The arrangement of the suction holes 2 is in rotation about the center M by 45 ° in itself, so has a achtzählige symmetry. The grinding wheel 1 shown in Figure 1 has a total area

A = - [(150 mm) ² - (16 mm) ² l «17470 mm ² .

4

Each of the suction holes 2 has an area of a = - (4 mm) ² ~ 12.57 mm ² .

4

Thus, the ratio of the total area of all suction holes 2 to the total area A of the grinding wheel 1 is approximately

56 · (4 mm) ²

= 4.03%.

(150 mm) ² - (16 mm) ² The mean distance between two adjacent hole circles in FIG. 1 is 10.375 mm. The mean absolute deviation from this mean distance is 1.0625 mm. Consequently, the mean absolute deviation is about 10% of the mean radial distance. Figures 2 and 3 show a second and third embodiment, the first embodiment differ only by the diameter of the suction holes 2: In the second embodiment according to Figure 2, this diameter d = 4.5 mm, while in the one shown in Figure 3 third embodiment d = 5 mm. The fourth exemplary embodiment illustrated in FIG. 4 is a further modification of that shown in FIG. In contrast to Figure 2, the grinding wheel 1 of Figure 4 has a diameter of D = 125 mm, and the diameter of the central attachment opening is 12 mm. In addition, it has only four bolt circles Ki, K ₄ , their arrangement and radii corresponding to those in Figure 2. However, the grinding wheel 1 shown in FIG. 4 does not contain a fifth pitch circle.

FIGS. 5 and 6 show further exemplary embodiments with 6 perforated circles Ki, K ₆ and associated radii ri, r _6, respectively. The numbers of the holes of the hole circles are in this embodiment _L n i = n _L2 = n _L 3 = n _L 5 = 8 and n _L 5 = n _L 6 16 = Also, the grinding wheel 1 illustrated in the figures 5 and 6 have n _s = 24 rays belonging to three steel types Ti, T ₂ , T ₃ : The jet type Ti contains only a single suction hole 2 at the radius r ₅ and therefore forms a single-hole jet. The jet type T ₂ contains at the radii r ₂ , r ₄ and r ₆ a suction hole 2, while the jet type T ₃ at the radii ri, r ₃ , r ₄ and r ₆ includes a suction hole 2. Each of the beams Si, S ₂ ,... Or each of the jet types Ti, T ₂ , T ₃ therefore contains exactly one, exactly three or exactly four centers of suction holes 2. The beam types are in the circumferential direction U in the order T ₂ , Ti , T ₃ , this sequence being repeated eight times over the entire angular range of 360 °. The angle between T ₂ and Ti and between T ₂ and Ti is 11.25 °, while between Ti and T ₃ is 22.5 °. The arrangement of the suction holes 2 is in rotation about the center M by 45 ° in itself, so has a achtzählige symmetry. The following table 2 summarizes the parameters for the embodiments described above:

Parameters Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

Diameter D of the 150 150 150 125 150 150

Grinding wheel 1 in mm

Diameter of the central 16 16 16 12 16 16

Mounting hole in mm

Total area A of 17470 17470 17470 12158 17470 17470

Grinding wheel 1 in mm ²

Diameter d of 4 4.5 5 4.5 4 4.5

Suction holes 2 in mm

Diameter of the central 16 16 16 12 16 16

Mounting hole 3 in mm

Number n _{L of} the suction holes 2 56 56 56 40 64 64

Number n _{K of} the bolt circles 5 5 5 4 6 6

Radii ri, r ₂ , ... the 18.5 18.5 18.5 18.5 17.5 17.5

Hole circles in mm 27.5 27.5 27.5 27.5 25 25

40 40 40 40 28.75 28.75

50 50 50 50 40 40

60 60 60 50 50

60 60

_Numbers η _Κ ι, η _Κ2 , ··· the 8 8 8 8 8 8

Exhaust holes 2 on the 8 8 8 8 8 8

Hole circles 16 16 16 16 8 8

8 8 8 8 16 16

16 16 16 8 8

16 16

Radius η of the single-hole circle 50 50 50 50 50 50 in mm

Number of hole circles whose 3 3 3 3 4 4

Radius is smaller than that

Radius of the single hole circle

Number n _s of beams 24 24 24 24 24 24 Number of jet types 3 3 3 3 3 3

Number of suction holes 2 1; 1; 3 1; 1; 3 1; 1; 3 1; 1; 3 1; 3; 4 1; 3; 4 on the types of jet

average number of 11.20 11.20 11.20 10.00 10.67 10.67

Suction holes 2 per bolt circle average number of 2.33 2.33 2.33 1.67 2.67 2.67

Suction holes 2 per jet

nJns

Ratio of total area 4.0% 5.1% 6.3% 5.2% 4.6% 5.8% of all 2 suction holes

Total area (A) of

Grinding wheel 1

Table 2

The inventive grinding wheels allow an efficient removal of grinding dust. The service life of the grinding wheel can thereby be significantly extended, so that the grinding wheels are consumed less quickly and therefore less often need to be replaced.

Claims

claims

Circular grinding wheel (1) having a center (M), comprising a plurality of in particular circular suction holes (2), wherein the

Center of each suction hole (2) on the intersection of a from the center (M) of the grinding wheel (1) outgoing beam (Si, S ₂ , ...) with a concentric with the center (M) arranged bolt circle (Ki, K ₂ , .. .) With radius (ri, r ₂ , ...) is arranged,

characterized in that

- At least one of the beams (Si, S ₂ , ...) is a Einlochstrahl (Su, S _i2 , ...), on which the center of only a single suction hole (2) is arranged;

- The centers of all suction holes (2), which are arranged on a Einlochstrahl (Su, S _i2 , ...), substantially on a common single-hole circle (K,) with radius (η) are;

- Each beam (S _j ) at least one radius () has the center of a suction hole (2), at which radius () the two in the circumferential direction of this beam (S _j ) adjacent beams (S _j -i, S _{j +} i) have no center of a suction hole (2).

Grinding wheel (1) according to claim 1,

characterized in that

the number of hole circles (Ki, K ₂ , ...) whose radius (ri, r ₂ , ...) is smaller than the radius (η) of the one-hole circle (K,) is in the range of 2 to 5 and preferably 3 or 4.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

each beam (Si, S _2, ...) is assignable to a jet type (Ti, T _2, ...), which indicates the amount of the radii (ri, r _2, ...), where (in this beam Si, S ₂ , ...) the center of a suction hole (2) is arranged, wherein the grinding wheel (1) at most 5, preferably at most 4, more preferably at most 3, particularly preferably exactly 3 different types of jet (Ti, T ₂ , ...).

Grinding wheel (1) according to one of the preceding claims,

characterized in that

on each beam (Si _, S ₂ , ...) at most 6, preferably at most 4, more preferably at most 3 centers of suction holes (2) are arranged.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

on each beam (Si _, S ₂ , ...) that is not a single-hole beam (Su, S _i2 , ...), the

Centers of at least 3 suction holes (2) are arranged.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

the number (n _L ) of all suction holes (2) is in the range from 20 to 100, preferably from 30 to 80, particularly preferably from 40 to 64.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

the number (n _s ) of the jets (Si, S ₂ , ...) containing at least one center of a suction hole (2) is in the range of 10 to 50, preferably 20 to 30, and more preferably 24.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

the number (n _K ) of the hole circles (Ki, K ₂ ,...) on which the center of at least one suction hole (2) is arranged is in the range from 3 to 10, preferably from 4 to 8, particularly preferably from 4 to 6 lies.

Grinding wheel (1) according to one of the preceding claims,

characterized in that

the average of the number of suction holes centered on a jet is in the range of 1.2 to 3, preferably 1.4 to 2.85, more preferably 1.6 to 2.7.

10. Grinding wheel (1) according to one of the preceding claims,

characterized in that

the average number of suction holes whose centers lie on a circle of holes is in the range from 6 to 20, preferably from 8 to 15, particularly preferably from 10 to 12.

11. Grinding wheel (1) according to one of the preceding claims,

characterized in that

the ratio of the total area of all suction holes (2) to the total area (A) of the grinding wheel (1) is in the range from 2% to 20%, preferably from 6% to 12%, particularly preferably from 4% to 7%.

12. Grinding wheel (1) according to one of the preceding claims,

characterized in that

at least 80%, preferably at least 90%, more preferably all the suction holes (2) are circular and have a diameter in the range of 3 mm to 6 mm, preferably 3.5 mm to 4.5 mm, particularly preferably 4 mm to 5 mm.

13. Grinding wheel (1) according to one of the preceding claims,

characterized in that

on each circle of holes (Ki, K ₂ , ...) the center of at least 8

Suction holes (2) are arranged, in particular of exactly 8 suction holes (2) or exactly 16 suction holes (2).

14. Grinding wheel (1) according to one of the preceding claims,

characterized in that

on each bolt circle (Ki, K ₂ , ...), the suction holes (2) are arranged uniformly in the circumferential direction.

15. Grinding wheel (1) according to one of the preceding claims,

characterized in that

the arrangement of the suction holes (2) is not substantially

is translationally symmetrical, the suction holes (2) are not arranged in particular at the vertices of a square grid or a triangular grid.