WO2006119900A1

WO2006119900A1 - Grinding disc for a grinding wheel

Info

Publication number: WO2006119900A1
Application number: PCT/EP2006/004127
Authority: WO
Inventors: Peter Schiebener
Original assignee: Hans Lingl Anlagenbau Und Verfahrenstechnik Gmbh & Co. Kg
Priority date: 2005-05-06
Filing date: 2006-05-03
Publication date: 2006-11-16
Also published as: EP1888301A1; DE102005043548A1

Abstract

The invention relates to a grinding disc (1a; 1b) for a grinding wheel (2) comprising grinding elements (17) for grinding objects and pumping segments (4) which are used and placed for pumping a fluid during grinding in a radial direction of the grinding disc or the grinding wheel from inside to outside.

Description

Slip ring for a grinding wheel

The present invention relates to a slip ring for a grinding wheel for grinding objects (such as bricks or the like).

A grinding wheel is a generally circular disc that rotates about a drive axis. On one or both of the large side surfaces, a slip ring is arranged or integrated, which has grinding elements with which the objects to be ground are ground. The slip ring is either a separate component that has the abrasive elements, wherein the slip ring can be manufactured separately and then applied to the grinding wheel or attached next to it. Alternatively, the slip ring is an integral part of the grinding wheel, i. The grinding wheel is already manufactured together with the slip rings having the grinding elements.

During grinding, the grinding wheel is driven by the slip ring and rotates while the articles to be ground are transported past it, thereby correspondingly grinding the edges or surfaces of the objects to be ground through the abrasive segments. In the prior art, there is now the problem that from the objects to be ground abraded abrasive particles remain on the grinding elements or on the grinding elements or on the grinding wheel and affect the grinding process. Some prior art systems use compressed air that is blown or directed outwardly from the center of the grinding wheel to carry these abrasive particles radially outward. This often causes the problem that abrasion of the grinding elements is generated by the transported with the compressed air abrasive particles. The washings generated thereby on the abrasive elements reduce the effective grinding surface of the abrasive segments and consequently have a negative effect on the life of the grinding wheels.

Furthermore, in the case of asymmetric washouts, the result is an imbalance of the slip ring, as a result of which damage to the machine, the slip ring or the product to be ground may occur.

The present invention therefore has the object of providing a grinding wheel for a grinding wheel, with grinding segments for grinding objects, which is designed so that the life is increased and an effective grinding is enabled. The above object is achieved by a slip ring for a grinding wheel according to claim 1.

The grinding wheel according to the invention for a grinding wheel comprises grinding elements for grinding objects and pumping segments, wherein the pumping segments are configured and arranged such that during grinding fluid is pumped from inside to outside in the radial direction of the slip ring or the grinding wheel.

The present invention is therefore based in particular on the idea to form the pump segments so that a removal of the resulting during grinding abrasive particles without external energy, such. B. compressed air, in the most effective manner possible. The fluid pumped outwardly through the design and arrangement of the pumping segments can be, for example, ambient air, a suitable gas, a suitable liquid or the like.

Advantageously, the pump segments are configured and arranged such that the pumping action is generated by an increase in the speed of the fluid during transport radially outward during grinding. The term "radial" here refers to the radius of the slip ring or the grinding wheel on which the slip ring is arranged or attached.

Further advantageously, the pump segments extend over the entire width of the slip ring and form between them each flow channels for the fluid. Advantageously, the flow channels have a constant cross-sectional area. Alternatively, the flow channels may also have a varying cross-sectional area, e.g. B. have an increasing from the inside out or a radially decreasing from the inside to the outside cross-sectional area. Advantageously, the pumping elements as arc segments, z. B. as circular arc elements formed. Advantageously, the pumping elements have a constant curvature. Alternatively, the pumping elements may also have a varying curvature.

Advantageously, the grinding elements of the slip ring according to the invention are arranged on the pump segments. In this case, the grinding elements can advantageously be arranged only on the radially outer regions of the pump segments. In one embodiment, the grinding elements are integrated in the radially outer regions of the pump segments and, alternatively, the grinding elements can also form the radially outer regions of the pump segments. Additionally or alternatively, one or more abrasive elements in each case between be arranged adjacent pumping segments. Advantageously, at least a part of the grinding elements extends over the entire width of the slip ring.

The following invention further relates to a grinding wheel with a slip ring according to the invention.

The present invention will be explained in more detail below with reference to a preferred embodiment with reference to the accompanying drawings, wherein

1 shows a schematic side view of an embodiment of a slip ring according to the invention and of a grinding wheel,

2 schematically shows the transport of abrasive particles with a slip ring according to the prior art,

3 schematically shows the transport of abrasive particles with a slip ring according to the present invention,

Fig. 4 shows schematically a side view of a grinding process with a slip ring according to the invention with objects to be ground, and

Fig. 5 shows schematically a longitudinal view of a grinding wheel with a slip ring according to the invention and objects to be ground.

Fig. 6 schematically shows a side view of a slip ring with cover and

conveyor belts,

7 shows schematically a side view of a further embodiment of a grinding wheel according to the invention,

FIG. 1 shows a schematic side view of a first exemplary embodiment of a slip ring 1 according to the invention with a grinding wheel 2. The grinding wheel 2, which may also be referred to as a grinding wheel, has a center hole 3 through which the grinding wheel 2 can be mounted on a drive shaft. The slip ring 1 is either an integral part of the grinding wheel 2 or a separately manufactured workpiece that is mounted on the grinding wheel 2 after manufacture and attached thereto. The slip ring 1 has pump segments 4, which are designed and arranged on the slip ring 1, that during the grinding process, the ambient air or other suitable fluid in the radial direction of the grinding wheel 2 is pumped from the inside to the outside. Here, the large arrow next to the center hole 3 of the grinding wheel 2 illustrates the direction of rotation, ie with respect to the plane of the drawing in the clockwise direction, and the two straight arrows between two pumping segments 4 visualize the flow direction of the pumped fluid. The pumping action is in this case caused according to the present invention without the supply of external energy, ie alone by the design and arrangement of the pumping segments 4 in cooperation with the rotation of the slip ring 1 during the grinding process.

The slip ring according to the present invention comprises not only the pumping segments 4 but also grinding elements 17 for grinding objects. In the exemplary embodiment shown in FIG. 1, the grinding elements 17 are arranged on radially outer regions of the slip ring 1. In this case, radially outward means those regions which lie outside in the radial direction of the slip ring 1 or the grinding wheel 2. In this case, the grinding elements 17 can either form separate elements which adjoin the pump segments 4 radially on the outside and are arranged, as it were, next to them. In a further embodiment, the grinding elements 17 can be integrated as inserts in the respective pump segments 4 or placed on them. Here, the grinding elements z. B. as a single abrasive particles such. As diamonds, inserted or integrated into the surface of the radially outer regions of the pump segments 4. However, the grinding elements 17 may also extend over the entire width B of the slip ring. This embodiment is z. B. for small slip rings advantage. It should be noted that usually between the plane of rotation of the slip ring and the grinding wheel and the grinding plane of the objects to be ground an acute angle is present, so that the objects to be ground are contacted only by the radially outer portions of the slip ring 1, so that need only be arranged in this area grinding elements 17.

As can be seen in Fig. 1, the pumping segments 4 are configured and arranged such that the pumping action is generated by an increase in the speed of the fluid during transport radially outward during grinding. In the embodiment shown, the pump segments 4 extend over the entire width B of the slip ring 1 and form between them each flow channels 14 for the fluid. Here, the pump segments 4 are arranged and designed such that the radially further inwardly lying areas of the pump segments 4 lead during operation, the more outer areas. This can be seen for example in Fig. 4, where an inventive slip ring 2 is shown together with objects to be ground 5. 4, the direction of rotation of the slip ring 1 in the clockwise direction, wherein the objects to be ground 5, such as bricks or the like, are transported from right to left at the bottom of the slip ring 1 over. The radially inner regions of the pump segments 4 and thus also the radially inner regions or grinding elements 17 rush to the respectively associated outer regions of the grinding elements 17. This in turn means that the outwardly exposed regions 21 of the pumping segments 4 accelerate the fluid present in the flow channels 14 outwards, whereby a negative pressure is created in the flow channels 14, which is compensated for by suction of fluid from radially further inward regions. This results in a pumping action, ie a transport of fluid through the flow channels 14 from the inside to the outside. This pumping effect is enhanced if the flow channels and the pump segments and the inner radial region of the grinding wheel 2 are covered. A part of the cover may be caused by the objects 5 to be ground, as shown in the longitudinal view in Fig. 5. Since the objects to be ground 5 cover the lower portion of the slip ring 2 and the pump segments 4, fluid, in the example shown, ambient air from the upper regions and sucked from outside the grinding wheel 2, as indicated by the arrow 9. This effect can be enhanced if further covers are also present in the upper part of the grinding wheel 2. An example of this is shown in Fig. 6, which schematically shows a side view of a slip ring 1 according to the invention with the objects 5 to be ground according to FIG. 4, wherein additionally in the upper region of the slip ring 1, a housing cover 18, which optionally an exhaust for the fluid may be present. Above the objects to be ground 5 is schematically illustrated a conveyor belt 19 with pressure stations for generating a pressure on the objects 5 to be ground and a conveyor belt 20 below the objects 5, which transports them past the grinding wheel 1 while they are being ground.

The arrow in the lower region of the housing cover 18 illustrates how ambient air is drawn in from the outside between the housing cover 18 and the conveyor belt 19.

If, however, as already briefly indicated above, an acute angle exists between the objects 5 to be ground and the plane of rotation of the grinding wheel 2, then only the radially outer regions of the slip ring 1 contact, that is to say only the grinding elements 17 as a rule to be dragged Articles 5. In this case, also in the lower part of the grinding wheel 2, a cover may be present to enhance the pumping action.

In the embodiment shown in Fig. 1, the shape of the pumping segments 4 is such that the pumping segments 4 are formed as arcuate segments, each pumping segment 4 having a substantially constant width b. Alternatively, the pump segments 4 may have a radially increasing width b from the inside to the outside or a width b decreasing radially from the inside to the outside. The curved shape of the pumping segments 4 can be generated, for example, by a constant curvature of the outer edges 12, 13. However, it is also an embodiment with a varying curvature of the outer edges 12, 13 conceivable. Furthermore, it is conceivable to equip the pump segments 4 not as arc segments but with a different geometric configuration, for example with (outer sections) straight outer edges 12, 13. It is important that the pumping effect according to the invention is caused. To assist the pumping action, it may be advantageous if the flow channels 14 each have a cross-sectional area which is the same radially from the inside to the outside or possibly even increases. However, embodiments are possible in which the cross-sectional area of the flow channels 14 decreases radially from the inside to the outside. Here, the cross-sectional area of the flow channels 14 is essentially determined by the geometric configuration of the pump segments 4. If, as shown in Fig. 1, the width b of the pumping segments 4 is substantially constant, the width of the flow channels increases from the inside to the outside. In order to achieve a constant cross-sectional area of the flow channels 14, therefore, the height of the pump segments 4 must decrease accordingly from the inside to the outside. In the context of the present invention, it is generally advantageous if the pump segments 4 have the narrowest possible width, since in this way optimum results are achieved with regard to the pumping action and the removal of abrasive particles from the inside to the outside.

In Figures 2 and 3, the advantageous effect of the present invention is explained in more detail. In Fig. 2 is schematically the transport of abraded abrasive particles

15 with respect to known from the prior art grinding elements 16. As mentioned in the introduction to the description, in the prior art there is an embodiment in which pressurized air from radially inward is supplied in order to remove abrasive particles 15 to the outside. Because the abrasive segments used

However, as has long been known, are arranged substantially tangentially, so the abrasive particles 15 more or less perpendicular to the side surfaces of the abrasive segments 16, as shown by the arrow 6. This creates a Abrasion on the grinding elements 16, which affect the grinding action and the life of the grinding elements 16. In contrast, the present invention not only allows a pumping action without supplying additional external energy, as it is necessary for compressed air, but also allows transport of abrasive particles 15 along the side walls of the pumping segments 4 and thus also on the integrated into the outer regions grinding elements 17, without any abrasion, as shown schematically in Fig. 3. An abrasive particle 15 is entrained radially from the inside to the outside by the pumped fluid and slides along the inside wall of a pumping segment 4, as shown by arrows 7 and 8. Due to the greatly reduced momentum exchange compared to the prior art of FIG. 2, abrasion of the abrasive elements 17 is effectively reduced.

7 shows a schematic plan view of a further possible embodiment of a slip ring 1 according to the invention. The embodiment of the slip ring 1 according to the invention shown in FIG. 7 comprises, similar to the embodiment shown in FIG. 1, a number of pump segments 4 extending from the inner radius of the slip ring 1 extend to the outer radius. At the radially outer regions of the pump segments 4 grinding elements 17 are arranged or integrated. It should be noted at this point that the embodiments and functions explained with reference to FIGS. 1 to 5 completely apply to the embodiment of FIG. 7 and are to be transmitted. In contrast to the embodiment of the slip ring 1a of FIG. 1, the slip ring 1b of FIG. 7 has additional grinding elements 17 which are arranged on the outer regions of the slip ring 1 between those grinding elements which are arranged on or adjacent to the pump segments 4. In other words, in addition to the grinding elements 17, which form the extension of the pump segments 4 in the radially outer regions of the slip ring 1 or are integrated into the radially outer regions of the pump segments 4 in this further grinding elements 17, which are not associated pump segments and are each arranged between adjacent pumping segments 4 at the radially outer regions of the slip ring Ib. These, so to speak, exposed grinding elements 17 are therefore arranged on the radially outer outlet openings of the flow channels 14. In order not to impair the flow in the flow channels 14, the grinding elements 17 are arranged so that their longitudinal axes parallel to the direction of flow of the fluid at the outlet openings of the flow channels 14. As can be seen in FIG. 7, the longitudinal axis of the grinding elements 17 is at an acute angle to the respective tangential direction on the outer radius of the slip ring 1b. It should generally be noted in the slip ring according to the invention that the grinding elements 17 as little as possible the fluid and abrasive particles transported from the inside to the outside To oppose resistance. Although in Fig. 7 the abrasive elements 17 have a rectangular end on their radially inner sides, it is advantageous in practice if a tapered end, for example a trapezoidal end, is provided to resist as little resistance as possible to the fluid being pumped outwardly , The same applies to the grinding elements 17, which are arranged on the outer regions of the pump segments 4. Again, a smooth transition between the pumping segments 4 and the abrasive segments 17 should be made without edges or the like are formed, as shown in the schematic representation of FIG. 7.

As explained above, the orientation of the pump segments 4 and grinding elements 17 is such that the radially inner regions lead the radially outer regions in the direction of rotation of the slip ring 1. The specific orientation and design of the pumping segments 4 with respect to the entry angle (radially inward) and exit angle (radially outward) depend on the size of the slip ring 1 and the specific requirements. Here, a goal is to arrange the pumping segments 4 on the radially inner side with such an angle that the relative speed between the fluid and the pumping segment 4 is minimal. An essential factor here is the cross-sectional area of the flow channels 14 at the inlet and outlet.

In general, the present invention enables targeted entrainment and transport of loose abrasive particles 15 from the center of the grinding wheel 2 and the grinding wheel outwardly through the flow channels 14 without damaging the abrasive segments 17. Furthermore, the flow of fluid past the pump segments 4 through the flow channels 14 allows for increased cooling of the abrasive segments 4. Furthermore, there is a reduced heat load on the surfaces of the pump segments 4 by short engagement lengths during grinding and by convection and circulation of the fluid on the surface of the segments 4 caused by the flow past, wherein the object to be sanded acts like a stationary housing cover disk during pumping. In addition, as mentioned, the abrasion of the abrasive segments 17 by the abrasive particles is greatly reduced by the reduced impulse load because the impact angle of the abrasive particles 15 on the abrasive segment 17 is greatly reduced. The abrasive particles 15 are drawn in the flow channels 14 by means of the main flow of the fluid through the channel or prevented by the boundary layer flows on the surfaces of the pump segments 4 from a direct contact.

Claims

claims

A slip ring (1a, 1b) for a grinding wheel (2), with grinding elements (17) for grinding objects and with pumping segments (4), wherein the pumping segments (4) are designed and arranged in such a way that during grinding, fluid in the radial direction the slip ring or the grinding wheel is pumped from the inside out.

The slip ring (1a, 1b) according to claim 1, wherein the pumping segments (4) are configured and arranged such that the pumping action is generated by an increase in the velocity of the fluid during transport radially outward during grinding.

Slip ring (Ia; Ib) according to claim 1 or 2, wherein the pumping segments (4) extend over the entire width (B) of the slip ring (Ia; Ib) and form between them respective flow channels (14) for the fluid.

The slip ring (1a, 1b) according to claim 3, wherein the flow channels (14) each have (4) a constant cross-sectional area (b).

5. slip ring (Ia; Ib) according to claim 3, wherein the flow channels (14) each have a radially increasing from the inside to the outside cross-sectional area.

6. slip ring (Ia, Ib) according to claim 3, wherein the flow channels (14) each have a radially decreasing from the inside to the outside cross-sectional area.

7. slip ring (Ia, Ib) according to one of claims 1 to 6, wherein the pumping elements (4) are formed as arc segments.

8. slip ring (Ia, Ib) according to one of claims 1 to 7, wherein the pumping segments (4) have a constant curvature.

9. slip ring (Ia, Ib) according to one of claims 1 to 7, wherein the pumping elements (4) have a varying curvature.

10. slip ring (Ia; Ib) according to any one of claims 1 to 9, wherein the grinding elements are arranged on radially outer region of the slip ring.

11. slip ring (1) according to one of claims 1 to 10, wherein at the radially outer regions of the pump segments grinding elements (17) are arranged.

12. slip ring (Ia; Ib) according to claim 11, wherein the grinding elements (17) are integrated into the radially outer portions of the pumping segments.

13. Slip ring (Ia; Ib) according to claim 11, wherein the grinding elements (17) form the radially outer portions of the pumping segments.

14. slip ring (Ia; Ib) according to any one of claims 1 to 13, wherein in each case one or more grinding elements (17) are arranged between adjacent pumping segments.

A slip ring (Ia; Ib) according to any one of claims 1 to 14, wherein at least a part of the abrasive elements extends over the entire width (B) of the slip ring (Ia; Ib).

16. grinding wheel (2) with a slip ring (Ia, Ib) according to one of claims 1 to 10.