EP2712704A2 - Cup grinding wheel - Google Patents

Abstract

The grinding disc (1) has a circular base disc (2) and several grinding segments (3). Each grinding segment is radially formed in outwardly open V-shape, and is provided with legs which are arranged axially symmetrical to a plane extending in the radial direction, in symmetry axis. The legs of grinding segment are extended to edge of circular base disc in radial direction.

Description

According to a first teaching, the invention relates to a cup grinding wheel having the features of the preamble of claim 1, a grinding segment for a cup grinding wheel having the features of the preamble of claim 10 and a grinding segment for a cup grinding wheel having the features of the preamble of claim 14.

According to a second teaching, which has independent significance, the invention relates to a base disk for a cup grinding wheel with the features of the preamble of claim 15.

Cup wheels are commonly used to abrade and polish hard surfaces such as concrete, marble, granite and other rocks, as well as to remove paint, varnish and other coatings from such base material. This is done by attaching such a cup grinding wheel to a central attachment opening of its round base disk on a portable grinder. The grinder then rotates the cup grinding wheel at the appropriate speed. The actual grinding action then regularly stirs from the attached on the surface of this base disk and projecting from her abrasive segments, which have about a diamond layer, the required hardness.

Such a cup grinding wheel, such as those from the EP 1 304 190 B1 is known, must meet various requirements. First, the grinding effect should be as strong as possible, so that a speedy and effective grinding is achieved even without strong contact pressure. Second, a uniform as possible grinding effect in the sense that even a non-uniform contact pressure of the cup grinding wheel on the surface to be ground does not lead to penetration of the cup grinding wheel in the surface to be ground at the relevant point. Third, it must also be ensured that abraded material does not deposit on the cup grinding wheel, but is moved away from it.

The realization of these and other advantageous properties depends essentially on the design and arrangement of the abrasive segments on the cup grinding wheel from. Their location, cross-sectional shape, orientation, size, and other geometric properties determine how these and other goals can be achieved.

The problem underlying the first teaching of the invention is consequently to further develop the cup grinding wheel known from the prior art and a grinding segment for such a cup grinding wheel so that both improved grinding action is achieved and excessive soiling of the cup grinding wheel by abraded material is avoided.

The above problem is in a cup grinding wheel according to the preamble of claim 1 by the features of the characterizing part of claim 1, in a grinding segment according to the preamble of claim 10 by the features of the characterizing part of claim 10 and in a grinding segment according to the preamble of the claim 14 solved by the features of the characterizing part of claim 14.

It is essential, based on the grinding cup, the realization that the known from the prior art - arrangement of the abrasive segments in the circumferential direction on the cup grinding wheel basically makes sense, advantageously the arms or legs of the abrasive segments but not in a tangential direction, but much more are arranged radially. Accordingly, with a V-shaped configuration of the abrasive segments, their respective open side is aligned in the radially outward direction. At first glance, this alignment is counterintuitive because it makes the abrasive segments seemingly transversely to the direction of rotation of the cup grinding wheel. In fact, it is better suited. In fact, since both legs of the V-shaped grinding segments have a substantially radial extent with respect to the cup grinding wheel, they have a significantly greater abrasive effect on both of them and on the edges formed by them over this entire length. The space between the legs then allows the abraded material to detach from the surface of the abrasive segments and initially deposit in that space. In addition, since this space is substantially closed or at least narrowed in the radial inner direction - since the legs converge here - the abraded material is simultaneously moved by the rotation Direction of the edge of the cup grinding wheel, where it is then removed from the cup grinding wheel.

With regard to the abrasive segment itself, the effect just described is promoted in particular by the fact that the further the legs of the grinding segment move away from each other, the more the effective grinding surface of the segment increases. It has been recognized in this context that it does not depend on the size of the space between the legs, as long as a certain minimum size of this space is guaranteed. Therefore, the area between the legs, which is due to the V-shape of the abrasive segments and therefore increases in the opening direction, can be used according to the invention for the most part and with good effect for the grinding surface itself.

Further, it has been recognized that a V-shaped abrasive segment assembly having a radially outwardly enlarging abrasive surface can also be made by allowing two or more widening abrasive segments to be aligned and angularly aligned with each other.

The preferred embodiment according to the first teaching of the cup grinding wheel according to the invention, in particular according to claim 2, and the inventive grinding segment according to claims 11 and 12 relate to embodiments in which the space between the legs of the grinding segment is formed particularly advantageous, in particular by having a ensures very good drainage of the abraded material from this space away from the cup grinding wheel and in particular prevents unwanted movement of the abraded material in the direction of the center of the cup grinding wheel.

Claims 3 to 5 related to the cup grinding wheel according to the first teaching again relate to advantageous embodiments of the end region of the V shape formed by the grinding segments. By a drop-like widening of the legs of the abrasive segments towards the edge, both the grinding effect can be improved as well as a located between the leg surface of the base disk are at least laterally enclosed, thereby adjusting in particular advantageous air flow conditions along the circumference of the cup grinding wheel.

Claims 5 and 6 as well as 8 and 9, which are also related to the cup grinding wheel according to the first teaching, additionally provide openings in the base disk, both as cutouts at the edge and as openings spaced from the edge. These not only improve the drainage of abraded material in addition, but also increase the effective cooling of the cup grinding wheel during operation.

Further relates to the Topfschleifscheibe according to the first teaching related claim 7 passages on the base disc, which are formed between the abrasive segments and contribute by their funnel-like nature, abraded material from inner regions of the grinding cup effectively to the edge of the cup grinding wheel and from there of the cup grinding wheel to move away.

Finally, the preferred embodiment of the grinding segment according to the first teaching of claim 13 specifically describes the lateral edges of the legs of the abrasive segments forming the V-shape.

The background of the second teaching of the invention further takes into account that in addition to the above abrasive segments, the cup grinding wheel often also has cutouts on the edge or passage openings through which the discharge of abraded material from the space between cup grinding wheel and grinding surface to be enabled and which next to a certain air circulation and provide the resulting cooling. In this way it is prevented that such material accumulates on the surface of the cup grinding wheel.

As a base disk is understood in relation to the second teaching of the invention, in particular only with reference to the second teaching of the invention, here and below the disk-shaped component, which either has a rough surface itself for grinding - in which case the base disk at the same time the associated Cup grinding wheel as a whole - or which is adapted to receive special protrusions for grinding such as said abrasive segments. If these projections are already arranged on the base plate, these projections in turn form together with the base disk, a cup wheel, otherwise it is a base disk, which is only by attaching these structures to a cup grinding wheel.

Thus, according to the second teaching of the invention, structural elements such as the abovementioned abrasive segments, cutouts and passage openings are present or at least provided regularly on such a base disk of a cup grinding wheel. The high speeds of the cup grinding wheel during operation require that advantageously the cup grinding wheel has its center of mass on its central axis, which corresponds to the axis of rotation during its rotational movement. Otherwise, a corresponding unbalance during operation would have a negative impact. The centering of the center of mass on the central axis is regularly achieved in that the said structural elements are arranged rotationally symmetrically on the base disk.

However, this symmetry often causes the problem that the cup grinding wheel becomes susceptible to resonant vibrations, which can also be distracting.

The problem underlying the invention according to the second teaching is therefore to further develop the known from the prior art base plate for cup grinding wheels to the effect that both caused by a shift of the center of mass unbalance and the occurrence of resonant vibrations is effectively prevented.

The above problem is solved according to the second teaching of the invention in a base disk for a cup grinding wheel having a central axis on which a center of mass of the base disk lies, the base disk comprising a group of structural elements, wherein each structural element of the group of structural elements is equidistant from the central axis and is arranged offset to adjacent structural elements of the group of structural elements with respect to the central axis by a predetermined angle, achieved in that at least two structural elements of the group of structural elements have a different cross-sectional contour. The following Embodiments relate to the second teaching of the invention and in particular only to the second teaching of the invention.

It is essential to realize that the requirement for a center of mass on the central axis of the base disk can be combined with a deviation from a rotational symmetry. Each structural element contributes to a displacement of the center of mass of an otherwise circularly symmetrical base disk from its central axis, either by a more mass - such as a grinding segment - or by a missing mass - in a depression or a passage opening with respect to a flat base. A rotationally symmetrical arrangement of such - in particular with regard to their cross-sectional contour - identical structural elements leads to compensate for each resulting by a single structural element shifts again.

However, even with non-identical cross-sectional contours of the structural elements, the center of gravity of the base plate can be held on the central axis by designing the cross-sectional contours of the structural elements precisely for this purpose. This applies equally to abrasive segments as well as to cut-outs and openings.

It is therefore apart, the angular offset offset around the central axis of the structural elements - as usual in the art - always give the same cross-sectional contour. On the contrary, at least two structural elements diverging in their cross-sectional contour are provided, but the resulting center of mass of the base disk (and also of the cup grinding wheel) remains on the central axis.

Maintaining the center of mass on the center axis of the base disk prevents the occurrence of imbalance. At the same time, the irregularity of the structural elements also prevents the occurrence of resonance vibrations.

As already explained, in principle a cup grinding wheel of this type can consist only of the base disk. Alternatively, the cup grinding wheel also have other components, including about subsequently attached Abrasive segments or any other structures can count. Of course, the central axis is only a fictitious line in the mathematical sense and also runs outside the base disk. The center of mass within the meaning of the present invention does not necessarily have to lie within the base disk or cup grinding wheel. Thus, the base disk may have deformations out of the plane of the base disk through which the center of mass shifts into an area outside the base disk.

A structural element in the sense of the second teaching of the invention means any structure on the base disk which leads to a contribution of the relevant point of the base disk to the calculation of the center of mass, which deviates from that of a base disk with only a flat surface. Primarily, as such structural elements on the one hand projections from the base disk such as abrasive segments and on the other hand through holes and cut-outs into consideration. In a broader sense, however, such structural elements also include any other types of material weakenings or material reinforcements. Bulges or bulges of the base disk, which have no weakening or amplification of the thickness of the base disk result, do not apply as structural elements in this sense.

Adjacent structural elements in this sense are those which have the smallest angular distance from one another in a direction of rotation relative to the central axis. It follows that each structural element has two adjacent structural elements - namely one for each direction of rotation - with the same distance to the central axis. The fact that each structural element of the group of structural elements is arranged offset to adjacent structural elements of the group of structural elements with respect to the central axis by a predetermined angle means, together with the already established equal distance from the central axis that substantially uniformly along a circle around the group of structural elements Center axis is arranged, wherein the angular distance between two adjacent structural elements corresponds to the predetermined angle.

Even with regard to the distance to the central axis of the structural elements of the group of structural elements, only a substantially equal distance is observed.

Both for assessing the angular offset and the distance to the central axis is to be based on the centroid of the respective structural elements. Just by a different cross-sectional contour can cause shifts of the centroid, which, however, are insignificant both for the assessment of the offset by the predetermined angle and for the distance to the central axis.

A cross-sectional contour in the sense of the second teaching of the invention means the outline of a structural element, that is to say a projection in the form of a grinding wheel or a depression in the form of a passage opening or a cutout. This outline corresponds to the cross section of the structural element, this cross section being formed by a plane which is arranged at right angles to the central axis of the base plate according to the invention in accordance with the second teaching. Advantageously, for the purpose of comparing the relevant cross sections, the same plane is used for the determination of all cross sections to be compared.

With regard to the tolerances to be used in the second teaching of the invention, the cross-sectional contour of one structural element from the cross-sectional contour of another structural element is considered to be different if the deviation is significant for the calculation of the center of mass.

Compared to a planar base disk, the contribution of a structural element to the center of mass can be regarded essentially as the integral of the position vector via the area enclosed by the cross-sectional contour of the structural element. A deviation between two cross-sectional contours in the sense of the invention is present if the integral calculated for the one cross-sectional contour can not also be used for the other cross-sectional contour. If a recalculation is necessary, there is a deviation. This is also the case if the contribution of the two cross-sectional contours despite deviation should prove to be identical after the calculation.

A preferred embodiment of the second teaching of the invention relates to preferred embodiments of the types of cross-sectional contours, which have the structural elements.

A further preferred embodiment of the second teaching of the invention, in turn, provides a further development in that the compensation of the effect on the center of mass of irregular structural elements does not take place within a single group of structural elements, but that at least one further group of structural elements is present and both groups of Structural elements together offset a shift of the center of mass. In other words, the structural elements of this further group cause, per se, a shift in the center of mass from the central axis. Together with the other structural elements of the base disk, in particular the structural elements of the first group, these displacements cancel each other again. With this possibility, the circle of variable structure elements to further increase, there are even more degrees of freedom in the design of the base disk.

Fig. 1

eine erste vorschlagsgemäße Topfschleifscheibe gemäß der ersten Lehre in einer Schrägansicht;

Fig. 2

dieselbe Ansicht wie in der Fig. 1 mit zusätzlicher Kenntlichmachung des Bewegungsverlaufs von abgeschliffenem Material;

Fig. 3

die vorschlagsgemäße Topfschleifscheibe der Fig. 1 gemäß der ersten Lehre in einer Draufsicht.

Fig. 4

die vorschlagsgemäße Topfschleifscheibe der Fig. 1 gemäß der ersten Lehre in einer Seitenansicht;

Fig. 5

eine weitere vorschlagsgemäße Topfschleifscheibe gemäß der ersten Lehre in einer Schrägansicht;

Fig. 6a

ein erstes vorschlagsgemäßes Schleifsegment gemäß der ersten Lehre für eine vorschlagsgemäße Topfschleifscheibe wie in der Fig. 1 in einer Schrägansicht;

Fig. 6b

das vorschlagsgemäße Schleifsegment der Fig. 6a in einer Draufsicht;

Fig. 7

ein weiteres vorschlagsgemäßes Schleifsegment gemäß der ersten Lehre in einer Draufsicht;

Fig. 8

eine vorschlagsgemäße Grundscheibe für eine Topfschleifscheibe gemäß der zweiten Lehre in einer Schrägansicht;

Fig. 9

die vorschlagsgemäße Grundscheibe der Fig. 8 in einer Draufsicht.

Fig. 10

die vorschlagsgemäße Grundscheibe der Fig. 8 in einer Seitenansicht.

In the following, the invention will be explained in more detail according to the first-mentioned teaching with reference to a respective two embodiments of a cup grinding wheel according to the invention and a grinding segment according to the invention. The invention according to the second teaching is illustrated in the drawing with reference to only one embodiment thereof. In the drawing shows

Fig. 1

a first proposed cup grinding wheel according to the first teaching in an oblique view;

Fig. 2

the same view as in the Fig. 1 with additional identification of the course of movement of abraded material;

Fig. 3

the proposed cup grinding wheel of Fig. 1 according to the first teaching in a plan view.

Fig. 4

the proposed cup grinding wheel of Fig. 1 according to the first teaching in a side view;

Fig. 5

another proposed cup grinding wheel according to the first teaching in an oblique view;

Fig. 6a

a first proposed abrasive segment according to the first teaching for a proposed cup grinding wheel as in Fig. 1 in an oblique view;

Fig. 6b

the proposed abrasive segment of the Fig. 6a in a plan view;

Fig. 7

a further proposed abrasive segment according to the first teaching in a plan view;

Fig. 8

a proposed base plate for a cup grinding wheel according to the second teaching in an oblique view;

Fig. 9

the proposed basic disc of Fig. 8 in a top view.

Fig. 10

the proposed basic disc of Fig. 8 in a side view.

The Fig. 1 to 4 The drawing shows a first grinding wheel according to the invention 1 according to the first teaching, which is suitable for grinding hard, especially stone surfaces. The Fig. 5 The drawing shows a further grinding wheel 1 according to the invention according to the first teaching, which is identical in its not explicitly described as differently described features to the first grinding wheel 1 according to the invention according to the first teaching. Unless otherwise explicitly distinguished between these two cup grinding wheels 1, consequently, both cup grinding wheels 1 are equally meant.

The cup grinding wheel 1 has a substantially circular base writing 2. Furthermore, the cup wheel 1 has a plurality of abrasive segments 3. These each have a radially outwardly open V-shape, which is formed by two legs 4, 5 of the abrasive segments 3. In other words, the two legs 4, 5 of the abrasive segments 3, which correspond to the two legs of the V-shape, run in the radial direction inwardly toward one another. In the context of the present invention according to the The first teaching is always meant with the radial direction of the radial direction of the cup grinding wheel 1 and thus also the base plate 2.

In the embodiments of the cup wheel 1 shown here according to the Fig. 1 to 5 For example, the V-shape of each grinding segment 3 consists of a single, integral grinding segment 3, so that the grinding segment 3 itself has this V-shape. However, it would also be conceivable that some or all of the V-shapes are formed from a multiplicity of individual abrasive segments, that is, abrasive segment sections. Consequently, the V-shape would be formed by a plurality of abrasive segments, not all of which would necessarily be V-shaped themselves. In this case, more or less large gaps could also be present between the individual grinding segment sections, which gaps are missing in the present case of the one-piece grinding segments 3. In the context of the invention according to the first teaching, and in particular hereinafter, by the term of a grinding segment 3 which has a V-shape, consequently also meant any group of grinding segment sections arranged in a V-shape.

In order to realize the advantageous properties of the V-shapes for both possible directions of rotation of the cup grinding wheel 1, it is particularly preferred that the legs 4, 5 are arranged axially symmetrical to a respective axis of symmetry 6 extending in the radial direction.

It is conceivable that the legs 4, 5, which form the V-shape of the abrasive segments 3, have an opening at the respective vertex of the V-shape, that is to say a distance between the two legs 4, 5 at the vertex of the V-shape. Form exists. However, it is preferred that the respective legs 4, 5 of a grinding segment 3 in the radial direction inwardly touch.

It is also conceivable that the contact of the two legs 4, 5 takes place in the form of a cross-connection, whereby approximately in the tangential direction of the base plate 2 straight edge could be formed on the abrasive segments 3. Alternatively, it is possible that - as in the Fig. 1 to 5 illustrated in the drawing - the respective legs 4, 5 of a grinding segment 3 at a respective point of contact in the radial direction inwardly form a convex bulge 7. Such a bulge 7 prevents that from happening the radially inwardly facing side of this point of contact of the legs 4, 5 can accumulate abraded material.

A particularly good grinding effect can be achieved by widening the respective legs 4, 5 of a grinding segment 3 along their radial extent to the outside in the tangential direction. It is preferred that the respective legs 4, 5 widen in a drop-like manner. By a drop-like broadening is here meant that the respective legs 4, 5 widened with a substantially uniform widening rate, ie not abruptly, and that this widening takes place without edges or kinks on the edge of the legs 4, 5. In this way, widened shoes 8, 9 at the respective divergent ends 4a, 5a of the legs 4, 5 are formed. The resulting widened surface of the abrasive segments 3 leads to a stronger abrasive action at the edges of the cup grinding wheel 1.

In order to achieve this good grinding action over the entire radial extent of the base disk 2, it is preferably provided that the respective legs 4, 5 of a grinding segment 3 extend in the radial direction as far as an edge of the base disk 2.

An advantageous embodiment provides that the respective legs 4, 5 of a grinding segment 3 at least partially - and preferably completely - enclose a respective edge surface 10 of the base disk 2 adjoining an edge of the base disk 2. This edge surface 10 has several technical functions. On the one hand, it forms a free space into which the material sanded off by a rotary motion in the first leg 4 can fall. It is thus prevented that this material affects the grinding action of the respective - depending on the direction of rotation - second leg 5. At the same time an inner edge 11a of this second leg 5 is exposed by this space. This inner edge 11a increases the grinding action of the second leg 5 compared to the hypothetical case in which a grinding segment structure between the two legs 4, 5 extends continuously in the tangential direction. Likewise, a corresponding opposite inner edge 11b of the first leg 4 is exposed.

Particularly good grinding properties result from the fact that the abrasive segment 3 forms a superficial angle β both at a point of contact of the inner edge 11a and at a point of contact of the inner edge 11b with the edge of the base plate 2. Preferably, this angle β is between 100 ° and 110 °. In particular, it can be 103 °. As a result, a course of the inner edge 11b is ensured, which ensures that abraded material is moved on this inner edge 11b in any case in the radial direction to the outside.

Finally, the peripheral surface 10, which is thus at least partially surrounded by the legs 4, 5, results in a reinforced air flow being formed around the circumference of the cup grinding wheel 1 by the rotary motion of the cup grinding wheel 1, which is suitable for grinding the abraded material from the surface of the cup grinding wheel 1 to remove. In this connection, it is particularly preferred that the legs 4, 5 completely surround the edge surface 10 adjoining the edge of the base disk 2. By such a complete enclosure is meant a complete enclosure of that part of the edge surface 10 which is not already enclosed by the edge of the base disk 2 itself. In other words, in this sense, the edge surface 10 is completely enclosed by the legs 4, 5 and the edge of the base plate 2.

In order to facilitate a flow away of the abraded material from the enclosed edge surface 10 and a cooling of the cup wheel 1 is preferred and as in the Fig. 1 to 4 provided that the edge surface 10 has a respective cutout 12 of the base plate 2. A cutout 12 in this sense is a recess or opening in the base disk 2, which is open relative to the edge of the base disk 2 and in particular completely penetrates the base disk 2. In the Fig. 2 possible cutout discharge directions 13 of the abraded material are represented by the cutout 12.

Based on this, it is advantageously provided that the cutout 12 as well as in the Fig. 1 to 4 shown - is arranged substantially centrally with respect to a vertex 14 of the respective grinding segment 3 in the tangential direction.

It can also be provided that the edge surface 10 has a respective edge passage opening 12a, as in the embodiment of FIG Fig. 5 is shown. This edge passage opening 12a, which delimits itself from the cutout 12 in that it is not open to the edge of the base disk 2, can alternatively - as shown here - or be present in addition to the cutout 12. It can then replace or reinforce the drainage and cooling effects of the cutout 12.

In addition to the improved grinding behavior of the abrasive segments 3 and the facilitated drainage of the abraded material from the edge surface 10 of the base plate 2, the abrasive segments 3 can also be arranged so that also an improved outflow of abraded material from centrally located portions of the cup grinding wheel 1 is achieved. For this purpose, it is preferably provided that passages 17 tapering in the radial direction are formed between the grinding segments 3 by respective outer edges 15, 16 of the legs 4, 5. The passages 17 formed in this way - which can also be referred to as funnel-like channels - between the inner region of the cup grinding wheel 1 and its edge ensure a largely residue-free outflow of abraded material from the central regions of the cup grinding wheel 1. The corresponding passage drainage direction 18 is in the Fig. 2 entered the drawing.

A particularly good outflow in this passage outlet direction 18 can be achieved, in particular, by the outer edges 15, 16 running straight at least in sections.

In this case, it is again particularly preferably provided that the outer edges 15, 16 are designed so that the straight running respective portion of the outer edges 15, 16 is arranged at an angle α to the edge of the base plate 2, which is preferably between 35 ° and 45 °. In particular, it is preferred that this angle α is 41 °. It has been found that with such an angle α, the outer edge 15 of the respective first leg 4 relative to the direction of rotation has a particularly suitable geometry for its grinding action.

An optimal outflow effect through the above-described passages 17 in turn arises from the fact that the straight running respective portions of the outer edges 15, 16 of adjacent abrasive segments 3 are arranged at an angle δ to each other, which is between 70 ° and 80 °. In particular, it is preferred that this angle δ is 72 °. This then corresponds to the opening angle of the passages 17. As from the Fig. 3 recognizable meet the imaginary extensions of said straight portions of the outer edges 15, 16 in just this angle, but at a point which lies outside the base plate 2.

It is also preferred that the straight running respective portions of the outer edges 15, 16 of a single grinding segment 3 are arranged at an angle γ to each other which is between 140 ° and 150 °. In particular, the straight portions of the outer edges 15, 16 of a single grinding segment 3, as shown in FIGS Fig. 3 shown to form an angle γ of 144 ° to each other. In this way, a good compromise is achieved, which on the one hand ensures a suitable angle of the outer edge 15 of the respective first leg 4 with respect to its grinding action and at the same time an adequate expansion of the legs 4, 5 in the radial inner direction on the base plate 2.

A further preferred embodiment of the cup grinding wheel 1 provides that the base disk 2 has an outer region 19, an inner region 20, preferably axially offset, and a transition region 21 between the outer region 19 and the inner region 20, the abrasive segments 3 being arranged in the outer region 19 , The inner region 20 regularly has the attachment opening 22, by means of which the cup grinding wheel 1 can be fastened to a grinding device. The axial return of the inner region 20 creates the possibly required space for such attachment. The oblique course of the transition region 21 prevents abraded material from sticking to the outer edge of the inner region 20. The abraded material thus flows out of the inner region 20 into the outer region 19 and from there, transported by the abrasive segment arrangement 3 away from the cup grinding wheel 1, as is likewise characterized by the throughflow direction 18.

In order to further improve the outflow of the abraded material and to additionally support the cooling of the cup grinding wheel 1, it is preferably further provided that the base plate 2 has axial passage openings 23, wherein the passage openings 23 extend at least partially into the passages 17. These through-holes 23 serve for the drainage of abraded material from both the inner region 20, as illustrated by the Durchgangsabflussrichtung 24, as well as directly from the abrasive segments 3, as the Segmentabflussrichtung 25 in the Fig. 2 is shown. Preferably, the passage openings 23 are arranged in the outer region 19.

Advantageously, the passage openings 23 are arranged in the tangential direction in each case centrally in the passages 17.

Likewise, it is preferred that the passage openings 23 are arranged at a distance from the abrasive segments 3. In other words, the passage openings 23 accordingly do not directly adjoin the outer edges 15, 16 of the legs 4, 5, but a planar part of the outer area 19 of the base plate 2 is located between the passage openings 23 and the outer edges 15, 16.

The Fig. 6a and 6b The drawing shows a single inventive abrasive segment 3 according to the first teaching of a cup grinding wheel 1 again. According to the invention, the abrasive segment 3 according to the first teaching on a V-shape, which is formed by two legs 4, 5 of the grinding segment 3, wherein the legs 4, 5 widen at their divergent ends 4a, 5a. This preferably takes place in the form of drops in the same sense as has already been described with regard to the cup grinding wheel 1 according to the invention in accordance with the first teaching. The diverging ends 4a, 5a of the legs are therefore those ends 4a, 5a of the legs 4, 5, which are arranged at the open end of the V-shape formed by the legs 4, 5.

Preferably, the legs 4, 5 are arranged axially symmetrically.

It is further preferred that the legs 4, 5 form a convex bulge 7 at its point of contact on an outer side 26 of the grinding segment 3. With the outer side 26 of the grinding segment 3 is meant the side of the grinding segment 3 pointing radially inwardly on the cup grinding wheel.

It is likewise preferred, as already described with regard to the cup grinding wheel 1, that the legs 4, 5 have outer edges 15, 16 which run straight at least in sections.

An undesired accumulation of abraded material within the concave side of a grinding segment 3 according to the invention can be avoided in particular in that the legs 4, 5 form a round recess 27 at its point of contact on an inner side of the grinding segment 3. According to the above definition of the outside 26, the inside of the grinding segment 3 on the cup wheel 1 radially outward.

As has already been described in connection with the cup grinding wheel 1 according to the first teaching according to the invention, it is also preferably provided in a grinding segment 3 according to the first teaching that the legs 4, 5 each have an inner edge 11a, 11b which extends straight at least in sections ,

Based on this, it is particularly preferred that these inner edges 11a, 11b are arranged at an angle to the respective outer edge 15, 16 of the leg 4, 5. This is a particularly elegant way to produce the preferred drop-like broadening of the legs 4, 5 at their divergent ends 4a, 5a.

It is likewise preferred that the cup grinding wheel 1, including the grinding segments 3, has one or more rotational symmetries relative to a central axis 28.

Further preferred embodiments of the inventive grinding segment 3 according to the first teaching will become apparent from the description of the cup grinding wheel 1 according to the invention in accordance with the first teaching.

Conversely, further preferred embodiments of the cup grinding wheel 1 according to the invention according to the first teaching are characterized in that they

Abrasive segments 3 having features which correspond to the preferred embodiments of the inventive grinding segment 3 according to the first teaching.

Finally, the Fig. 7 Another inventive abrasive segment 3a according to the first teaching for a cup grinding wheel 1 again. The grinding segment 3a has a leg 4b, which widens drop-wise at a leg end 4c. This drop-like broadening is to be understood as well as the corresponding drop-like broadening of the already described grinding segment 3 according to the first teaching with the two legs 4, 5.

It is preferred that the grinding segment 3a has a single leg 4b.

It is further preferred that this leg 4b at its leg end 4c also formed so that the longer edge 15a of the leg 4b to the foot edge 29 of the leg 4b at the drop-like widened leg end 4c forms an angle α, which the angle α of the grinding segment 3 with the two legs 4, 5 corresponds.

It is also preferred that the shorter edge 11c of the leg 4b forms an angle β to the foot edge 29 of the leg 4b at the drop-like widened leg end 4c which corresponds to the angle β of the grinding segment 3 with the two legs 4, 5.

Preferred embodiments of the further inventive grinding segment 3a according to the first teaching related to the angles α and β correspond to preferred embodiments of the grinding segment 3 with the two legs 4, 5.

That in the Fig. 7 shown abrasive segment 3a is particularly adapted to be arranged together with a corresponding, mirrored grinding segment, which forms a counterpart together on a cup grinding wheel 1 so that a grinding segment arrangement is formed, which substantially the contour of the in the Fig. 6a illustrated grinding segment 3 with the two legs 4, 5 corresponds, wherein, in contrast to the situation in the Fig. 6b between the Abrasive segment 3a and its counterpart a gap can remain.

Accordingly, further preferred embodiments of the further inventive grinding segment 3a according to the first teaching of preferred embodiments of the already described inventive grinding segment 3 with the two legs 4, 5 according to the first teaching, wherein the features of the grinding segment 3a from the corresponding features of the grinding segment 3 directly or follow suit.

The drawing continues in the Fig. 8 . 9 and 10 an inventive base plate 101 for a cup grinding wheel 102 according to the second teaching. This cup grinding wheel 102 is suitable for grinding hard, especially stone surfaces. It can be seen that it has an outer, lying in a first plane outer region 103, an inner, lying in a recessed plane inner region 104 and extending at an angle to these two levels transition region 105. The inner region 104 has a concentrically arranged, circular attachment opening 106. A central axis 107 of the cup grinding wheel 102 extends through the center of the outer region 103, the inner region 104, the transition region 105 and the circular attachment opening 106. By means of the circular attachment opening 106, the base disk 101 shown can be attached to a grinding device, not shown here, which in turn the cup grinding wheel 102 for the grinding process in the corresponding rotation can put. The center axis 107 of the base disk runs concentrically with the outer region 103, the inner region 104, the transition region 105 and the attachment opening 106.

In total, three groups of structural elements 108, 109, 110 are arranged on the base plate 101, each along a circle about the central axis 107 in the outer area 103: a first group of structural elements 108 is formed of five through holes 108a, a second group of structural elements 109 is formed of five abrasive segments 109a and a third group of structural elements 110 is formed of five cutouts 110a on the edge of the base plate 101. Each of these mentioned sets of structural elements 108, 109, 110 basically represents in each case a group of structural elements 108, 109, 110 Interior area 104 is not considered a structural element in this sense, since it is not a local weakening or reinforcement of the material of the base disk 101.

According to the invention, according to the second teaching, the base disk 101 comprises a group of structural elements 110, wherein, according to the exemplary embodiment shown in the drawing, the group of structural elements 110 formed by the cutouts 110a in the form of circular segments is decisive.

According to the invention according to the second teaching, each structural element 110 of this group of structural elements 110 is at the same distance from the central axis 107 and is offset relative to adjacent structural elements 110 of the group of structural elements 110 with respect to the central axis 107 by a predetermined angle.

Like from the Fig. 8 can be seen, the distance between these cutouts 110a to the central axis 107 is greater than that of the abrasive segments 109a, which in turn is greater than that of the through holes 108a. According to a number of five structural elements 108, 109, 110 for all said groups, the predetermined angle by which the structural elements 108, 109, 110 are offset to their neighbors, in the present case 72 °.

The base disk 101 according to the invention according to the second teaching is characterized in that at least two structural elements 110 of the group of structural elements 110 have a different cross-sectional contour. Specifically, in the base disk 101 shown in the drawing, the cutouts 110b have a cross-sectional contour which deviates from the cross-sectional contour of the cutouts 110c. This cross-sectional contour, in turn, deviates from the cross-sectional contour of the cutout 110d. In this case, the cross-sectional contour of the cutouts 110b is identical to one another, just like the cross-sectional contour of the cutouts 110c relative to one another. It can be seen that the radius of the corresponding circle of the circle segments of the cutouts 110c is greater than the radius corresponding to the cutouts 110b. This in turn is greater than the radius corresponding to the cutout 110d.

However, for the group of cutouts 110a, consisting of the cutouts 110b, the cutouts 110c and the cutout 110d, it holds true that despite the deviations in the respective cross sectional contour described, this embodiment of the cutouts 110a does not shift the center of mass of the base disk 101. The structural elements 110 - ie cutouts 110a - of the group formed by them balance each other out so that the center of mass of the base plate 101 is still on the central axis 107. This is the case if and only if the - fictitious, but calculable - center of mass of the "negative", because missing mass defined by the cutouts 110a also lies on the central axis 107.

It is particularly preferred that the mutually deviating respective cross-sectional contour of the at least two structural elements 110 has a deviation of the respective area of the cross-sectional contour of at least 5 percent. In other words, the two cross-sectional contours in question in any case differ from one another in that the area of one cross-sectional contour is greater by at least 5 percent than the area of the respective other cross-sectional contour. Preferred advancements provide that this difference in area is at least 10 percent, and in particular at least 15 percent.

It is also particularly preferred that the cross-sectional contour of each structural element 110 of the group of structural elements 110 belongs to the same contour type. The Fig. 9 illustrates alternative and preferred contours formed by a cut with a polygon 110e, a circle 110f, or an ellipse 110g. Accordingly, the cross-sectional contour of each structural element 110 belongs to a group of structural elements 110 of the type of a curve, a polygon (110e), a circle (110f) of an oval or an ellipse (110g). The cross-sectional contours formed thereby may also belong to the type of a segment of a polygon 110e, a segment of a circle 110f, or a segment of an ellipse 110g. These may also be cross-sectional contours of a complete polygon 110e, a circle 110f or an ellipse 110g. In addition, corresponding contours based on a curve or an oval and its corresponding segments are preferred. The fact that each structural element belongs to the same type of contour ensures that the structural elements 110 look similar to a group. The differences in cross-sectional contour can be designed in this way so that they hardly or not at all notice the superficial viewer. As a result, the user's aesthetic desire for a symmetrical base disk 101 is taken into account. In the present case, the cutouts 110a have a cross-sectional contour in the manner of a circle segment. It is not essential that - from the perspective of the base disk 101 - outer boundary of the circle segment is not formed by a straight line, as is strictly the case with a circular segment of the case, but by a circular arc, namely that of the base plate 101. The same applies for segments formed by other types of contours.

According to another preferred embodiment, each structural element 110 of the group of structural elements 110 has the same axial extension direction. The axial direction of extension of a structural element can either be a positive expansion direction in the case of protrusions or other structural elements produced from the surrounding plane, or a negative expansion direction for openings, recesses and depressions. In other words, this preferred embodiment can be described by the fact that within a group all structural elements are exclusively projections only - in the sense of material reinforcements - or openings, recesses or recesses - in the sense of material weakenings. In the exemplary embodiment shown, this applies to all three groups of structural elements 108, 109, 110 according to FIG Fig. 8 The first group consists only of through holes 108a with a negative axial extension direction, the second group only of abrasive segments 109a with a positive axial extension direction and the third group of cutouts 110a in turn with a negative axial extension direction.

It is also preferred that the base plate 101 comprises a further group of structural elements, wherein each structural element of the further group of structural elements has a same further distance from the central axis 107 and adjacent structural elements of the further group of structural elements with respect to the central axis 107 by a further predetermined angle is arranged offset, wherein at least two structural elements of the other Group of structural elements have a different cross-sectional contour. In this case, the same further distance to the central axis 107 of this further group of structural elements is regularly different from the distance to the central axis of the (first) group of structural elements 110 and can be either smaller or larger. This also applies to the further predetermined angle by which the further group of structural elements is offset.

In other words, in this embodiment it is preferred that, in addition to the (first) group of structural elements 110 required herein consisting of the cutouts 110a, another (second) group of structural elements having the properties required according to the invention for the (first) group of structural elements is available. In the embodiment shown in the drawing according to the Fig. 8 the cutouts 110a form the (first) group of structural elements 110. Thus, in principle, the through-openings 108a and the abrasive segments 109a would also be considered as a further group in the sense of this preferred embodiment.

A preferred further development provides that each structural element of the further group of structural elements has an axial expansion direction which corresponds to the axial expansion direction of the (first) group of structural elements 110.

In the illustrated embodiment, this would basically apply to the group of through-openings 108a, since all the through-openings 108a as well as the cut-outs 110a of the (first) group of structural elements 110 have a negative axial expansion direction corresponding to the character of an opening or material weakening.

An alternative development - which could also be realized in the same embodiment, if additionally such a group of structural elements is present - provides that each structural element of the further group of structural elements has an axial extension direction which the axial extension direction of the (first) group of Structural elements 110 is directed opposite. In the embodiment shown here, this would basically apply to the group of abrasive segments 109a, because all of the abrasive segments 109a represent protrusions having a positive axial extension direction, whereas the cutouts 110a of the (first) group of structural elements 110 have a negative and thus opposite axial extension direction.

It is also preferred that at least two structural elements 110 of the group of structural elements 110 have an identical contour contour. This means nothing else than that not all structural elements 110 of a group have a respective unique outline contour. Thus, both the two cutouts 110b and the two cutouts 110c each have an identical outline contour.

It may be advantageous for the group of structural elements 110 to consist of an even number of structural elements 110.

On the other hand, advantages also result if the group of structural elements 110 consists of an odd number of structural elements 110. Thus, in the embodiment shown in the drawing, five cutouts 110a are present in the group of structural elements 110.

Furthermore, it is preferred that each structural element 110 from the group of structural elements 110 has an identical cross-sectional contour to a respective further structural element 110 from the group of structural elements 110. In other words, according to this preferred embodiment, none of the structural elements 110 of the group of structural elements 110 has a unique cross-sectional contour.

Alternatively, it is also preferred that a structural element 110 of the group of structural elements 110 has a cross-sectional contour that deviates from the cross-sectional contour of the other structural elements 110 of the group of structural elements 110. In other words, this advantageous refinement can be described in that at least one structural element 110 of the respective group of structural elements 110 has a unique cross-sectional contour, which in the case illustrated here applies specifically to the cutout 110d. The others, a total of four cutouts 110b and 110c all have a to the cross-sectional contour of the cutout 110d different cross-sectional contour.

A preferred embodiment is characterized in that the group of structural elements 110 consists of abrasive segments with an axial extension direction in the protrusion direction. In principle, the grinding segments 109a of the cup grinding wheel 102 would be suitable for this purpose.

According to an alternative embodiment, the group of structural elements 110 consists of recesses with an axial extension direction in the recess direction. This is the case for the cutouts 110a, since these are cutouts which belong to the cutouts with respect to their axial extension direction. In addition, the passage openings 108a of the cup wheel 102 could be considered.

It is particularly preferred that the recesses completely penetrate the base disk 101. In this way, there is the possibility that the recesses not only fulfill a function with respect to the centering of the center of mass while canceling the circular symmetry, but also allow, for example, the removal of abraded material through these recesses. Thus, in the present embodiment, both the cutouts 110a and the through openings 108a form recesses which completely penetrate the base disk 101.

It is further preferred that the recesses comprise cutouts 110a at an edge of the base disk 101. It is particularly preferred that the recesses consist of cutouts 110a at one edge of the base plate 101. Cutouts in this sense are recesses which are open towards the edge of the base plate 101 and in particular completely penetrate the base plate 101. Depending on the arrangement of the abrasive segments 109a, an arrangement of such recesses on the edge of the base disk 101 for the removal of abraded material and cooling of the cup grinding wheel 102 can be particularly helpful.

Claims (15)

Cup grinding wheel (1) having a substantially circular base disk (2) and a plurality of grinding segments (3),
characterized in that
the abrasive segments (3) each have a radially outwardly open V-shape, which is formed by two legs (4, 5) of the abrasive segments (3), preferably, that the legs (4, 5) axisymmetric to a in Radial direction extending respective symmetry axis (6) are arranged, in particular, that the respective legs (4, 5) of a grinding segment (3) in the radial direction inwardly touch. Cup grinding wheel (1) according to claim 1, characterized in that the respective legs (4, 5) of a grinding segment (3) at a respective point of contact in the radial direction inwardly form a convex bulge (7). Cup grinding wheel (1) according to Claim 1 or 2, characterized in that the respective limbs (4, 5) of a grinding segment (3) widen outward along their radial extent in the tangential direction, preferably in a drop-like manner. Cup grinding wheel (1) according to one of claims 1 to 3, characterized in that the respective legs (4, 5) of a grinding segment (3) extend in the radial direction up to an edge of the base disk (2). Cup grinding wheel (1) according to one of claims 1 to 4, characterized in that the respective legs (4, 5) of a grinding segment (3) at one edge of the base disc (2) adjacent respective edge surface (10) of the base disc (2) at least partially, preferably completely, enclose, in particular, that the edge surface (10) has a respective cutout (12) of the base disk (2), further in particular that the cutout (12) substantially tangentially in the tangential direction with respect to a vertex (14) of the respective Abrasive segment (3) is arranged. Cup grinding wheel (1) according to claim 5, characterized in that the edge surface (10) has a respective edge passage opening (12a). Cup grinding wheel (1) according to one of claims 1 to 6, characterized in that between the grinding segments (3) by respective outer edges (15, 16) of the legs (4, 5) in the radial direction funnel-like converging passages (17) are formed, preferably in that the outer edges (15, 16) run straight at least in sections. Cup grinding wheel (1) according to claim 7, characterized in that the base disc (2) has an outer region (19), an axially offset inner region (20) and a transition region (21) between the outer region (19) and the inner region (20 ), wherein the abrasive segments (3) in the outer region (19) are arranged. Cup grinding wheel (1) according to claim 7 or 8, characterized in that the base disc (2) has axial passage openings (23), wherein the passage openings (23) extend at least partially into the passages (17), wherein in particular the passage openings (23) are arranged in the outer region (19), preferably that the through-openings (23) are arranged in the tangential direction in each case centrally in the passages (17), more preferably, that the passage openings (23) spaced from the abrasive segments (3) are arranged. Grinding segment (3) for a cup grinding wheel (1), the grinding segment (3) having a V-shape which is formed by two limbs (4, 5) of the grinding segment (3),
characterized in that
the limbs (4, 5) widen at their divergent ends (4a, 5a), preferably like drops. Sanding segment (3) according to claim 10, characterized in that the legs (4, 5) are arranged axially symmetrically. Sanding segment (3) according to claim 10 or 11, characterized in that the legs (4, 5) form a convex bulge (7) at their point of contact on an outer side (26) of the sanding segment (3). Abrasive segment (3) according to any one of claims 10 to 12, characterized in that the legs (4, 5) outer edges (15, 16) which run at least partially straight. Grinding segment (3a) for a cup grinding wheel (1), the grinding segment (3a) having a, preferably individual, limb (4b),
characterized in that
the leg (4b) widened dropwise at one leg end (4c). A base disk (101) for a cup wheel (102) having a central axis (107) on which a center of mass of the base disk (101) lies, wherein the base disk (101)
comprises a group of structural elements (110),
each structural element (110) of the group of structural elements (110) being equidistant from the central axis (107) and
is arranged offset to adjacent structural elements (110) of the group of structural elements (110) with respect to the central axis (107) by a predetermined angle,
characterized in that - At least two structural elements (110) of the group of structural elements (110) have a respective divergent respective cross-sectional contour.

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