EP3542959B1 - Dressing device - Google Patents

Description

The invention relates to a dressing device for dressing a grinding tool provided with a predetermined grinding profile with the features of the preamble of claim 1 and a method for dressing a grinding tool by means of at least one such dressing device.

Grinding tools have to be dressed after a certain period of time in the grinding operation, whereby several processes are differentiated from one another during dressing.

One of these processes is to sharpen the grinding profile of the grinding tool. In doing so, e.g. impurities are removed, abrasive grains that have become blunt are removed, new abrasive grains are exposed and / or abrasive grains are sharpened, e.g. by breaking.

Another process is to restore the grinding tool's grinding profile. In the course of this process, binder material, abrasive deposits and / or abrasive grains are removed with the aim of restoring the specified grinding profile of the grinding tool.

Dressing tools with a uniform specification, which is designed for a compromise between the different dressing processes, are known from the prior art.

This has a detrimental effect on the maximum service life of the grinding tool, i.e. the period between the first use of the grinding tool and the point in time at which the grinding profile of the grinding tool is damaged to such an extent that the grinding tool has to be sent back to the manufacturer in order to machine the original grinding profile, preferably by spark erosion, to restore, out.

It's over US-A-2005/0245176 known that the dressing device comprises two dressing areas, one of the two dressing areas being based on the pre-profiling process Restoration of the grinding profile and the other of the two dressing areas is optimized for the finish process of restoring the grinding profile.

Alternatively, one could also consider using two different dressing devices, each with a dressing area, one of the two dressing devices being designed for the process of restoring the grinding profile and the other of the two dressing devices for the process of sharpening. However, the two dressing devices would then have to be used alternately, which is associated with increased positioning effort. In comparison, it is possible with the present dressing device to position it only once, for example in a feed device, and to use up the second and then the first dressing area at least for the most part. In this way, there is an automatic change between the process of restoring the grinding profile and the process of sharpening without having to change the position of the dressing device relative to the feed device.

The disadvantage of such a dressing device is the often relatively cumbersome handling.

The object of the present invention is to provide a dressing device which is improved over the prior art and which, in particular, enables an increased service life of the grinding tool dressed with the dressing device. Another object is to specify a method for dressing a grinding tool by means of at least one such dressing device, which in particular enables efficient dressing of a grinding tool and an increased service life of the grinding tool.

These objects are achieved by the features of independent claims 1 and 6.

In the dressing device according to the invention, it is provided that the first dressing area has a first specification for sharpening the grinding profile of the grinding tool and the second dressing area has a second specification deviating from the first specification for restoring the grinding profile of the grinding tool, the first dressing area having a larger volume than the second dressing area has,

• einer Länge von 150 mm bis 250 mm, besonders bevorzugt 180 mm bis 200 mm, und/oder
• einer Breite von 25 mm bis 75 mm, besonders bevorzugt ca. 50 mm, und/oder
• einer Dicke von 2,0 mm bis 10,0 mm, besonders bevorzugt ca. 3,0 mm, 4,0 mm oder 5,5 mm.

and that the dressing device is essentially cuboid, preferably with

• a length of 150 mm to 250 mm, particularly preferably 180 mm to 200 mm, and / or
• a width of 25 mm to 75 mm, particularly preferably approx. 50 mm, and / or
• a thickness of 2.0 mm to 10.0 mm, particularly preferably about 3.0 mm, 4.0 mm or 5.5 mm.

In the dressing device according to the invention, it is therefore provided that the dressing device comprises at least a first dressing area and a second dressing area connected to it, the first dressing area having a first specification for sharpening the grinding profile of the grinding tool and the second dressing area a second specification deviating from the first specification Having restoration of the grinding profile of the grinding tool, and wherein the first dressing area has a larger volume than the second dressing area.

It is also provided that the dressing device is essentially cuboid, preferably with a length of 150 mm to 250 mm, particularly preferably 180 mm to 200 mm, and / or a width of 25 mm to 75 mm, particularly preferably approx. 50 mm mm, and / or a thickness of 2.0 mm to 10.0 mm, particularly preferably approx. 3.0 mm, 4.0 mm or 5.5 mm. A cuboid design of a dressing device with such dimensions additionally facilitates the handling of the dressing device.

With regard to the handling of the dressing device, it is also advantageous that the dressing device has a holding area for holding the dressing device when dressing the grinding tool, preferably wherein the holding area is designed without abrasive grain and / or is glued or sintered on, and / or in It consists essentially of a water-soluble material. Without this holding area, the dressing device would have to be held at one of the two dressing areas, which could no longer be used for dressing in the area used for holding and would have to be disposed of as waste.

In principle, the holding area can already be produced when the two dressing areas are produced. Then a material is used that can withstand pressure and temperature during the manufacture of the dressing areas. Here, for example, a cost-effective ceramic material is available, similar to a "Sparkern" in ceramic grinding wheels.

Alternatively, it is advisable to attach the holding area only after the two dressing areas have been produced, for example by gluing. A wide variety of materials, such as wood, plastic or organic materials, can be used. The prerequisite is sufficient strength and the possibility of bonding to the dressing areas.

In the event that the material of the holding area is water-soluble, the holding area could be disposed of or recycled in a simple manner after its use by dissolving it in water.

Because the first dressing area has a larger volume than the second dressing area, an optimal ratio can be set between the dressing step of profiling and the dressing step of sharpening. In practice it is often the case that a grinding tool is profiled with less frequency than it is sharpened, and that a smaller volume of dressing material is consumed during profiling compared to sharpening.

It has been found to be advantageous that the volume of the first dressing area is approx. 4 to 7 times, preferably approx. 6 times, greater than the volume of the second dressing area.

The specification of the first and second dressing area depends on the specific design of the grinding tool and the specific application of the grinding tool. In general, the specification of the second dressing area will be made more aggressive than the specification of the first dressing area, whereby the specification of the second dressing area is designed to remove more abrasive grains and / or binder material compared to the specification of the first dressing area.

For example, for the dressing of grinding tools which are used for grinding workpieces in the form of glass panes, it is advisable that the first specification has an average pore size of 200 to 500 µm, preferably approx. 350 µm, and / or high-grade corundum white as the abrasive grain, and / or an abrasive grain with a grain size of 120 to 220 mesh, preferably about 180 mesh.

With regard to the second specification, it is advisable that the second specification has a porosity in the range of 10 to 15 percent by volume, and / or has a mixture of white aluminum oxide and pink aluminum oxide and / or red aluminum oxide as the abrasive grain, and / or an abrasive grain with a grain size of 35 to 100 mesh, preferably about 55 mesh.

White corundum consists of more than 99.9% Al ₂ O ₃ (aluminum oxide) and is extremely hard and heat-resistant up to 2000 ° C. Fine corundum pink has a small amount of foreign matter, which gives it a somewhat higher grain toughness and enables it to be used for shape and profile grinding due to its higher edge strength. Otherwise it corresponds to white corundum. Chromium or titanium, for example, are added as foreign substances as oxide in the melting process. In the event that chromium oxide is added as a foreign substance, pink and red aluminum oxide can be distinguished from each other in that pink aluminum oxide is about 0.25% Cr ₂ O ₃ and red aluminum oxide is about 2% Cr ₂ O ₃ contains.

A ceramic bond is suitable as the bond both in the case of the first and in the case of the second specification.

As stated above, protection is also desired for a method for dressing a grinding tool by means of at least one dressing device according to the invention, the method having a first method step in which the grinding profile of the grinding tool is restored by means of the second dressing area of the at least one dressing device, and a second method step, in which the grinding profile of the grinding tool is sharpened by means of the first dressing area of the at least one dressing device.

The first method step preferably takes place before the second method step. However, the two process steps can also be carried out in reverse chronological order.

Furthermore, it is advisable that the first method step is repeated with a first frequency N1 before the implementation of the second method step and the second method step is repeated with a second frequency N2 after the first method step, which is repeated with the frequency N1, where N1 <N2 .

It has also been found to be advantageous that the first method step is carried out or repeated before the second method step is carried out until at least a predominant part of the second dressing area is used up, and the second method step is carried out or repeated after the first method step has been completed, until at least a predominant part of the first dressing area is used up. In this way, an automatic change between the dressing step of profiling and the dressing step of sharpening can be realized.

• das Schleifwerkzeug vor dem ersten Verfahrensschritt, und/oder zwischen dem ersten und zweiten Verfahrensschritt, und/oder nach dem zweiten Verfahrensschritt, und/oder zwischen einer gegebenenfalls vorgesehenen Wiederholung des ersten oder zweiten Verfahrensschritts mehrmals zum Schleifen wenigstens eines Werkstücks, vorzugsweise einer Glasscheibe, verwendet wird, und/oder
• die Abrichtvorrichtung einen Haltebereich zum Halten der Abrichtvorrichtung beim Abrichten des Schleifwerkzeugs aufweist und die wenigstens eine Abrichtvorrichtung zumindest während des ersten und zweiten Verfahrensschritts zumindest am Haltebereich in einer Zuführvorrichtung gehalten wird, und/oder
• das Verfahren sequenziell mit mehreren aufeinanderfolgenden Abrichtvorrichtungen durchgeführt wird, wobei eine weitere Abrichtvorrichtung, vorzugsweise aus einem Magazin, zugeführt wird, sobald eine vorausgehende Abrichtvorrichtung zumindest zum überwiegenden Teil aufgebraucht ist, und/oder
• das Verfahren zumindest zum überwiegenden Teil automatisiert abläuft.

Further advantageous embodiments of the method consist in that

• the grinding tool is used several times for grinding at least one workpiece, preferably a pane of glass, before the first process step, and / or between the first and second process step, and / or after the second process step, and / or between an optionally provided repetition of the first or second process step will, and / or
• the dressing device has a holding area for holding the dressing device when dressing the grinding tool and the at least one dressing device is held at least on the holding area in a feed device at least during the first and second method step, and / or
• the method is carried out sequentially with several successive dressing devices, with a further dressing device, preferably from a magazine, being supplied as soon as a preceding dressing device is at least predominantly used up, and / or
• the process is at least for the most part automated.

Fig. 1a

eine perspektivische, schematische Darstellung einer Anordnung aus einem Werkstück, einem Schleifwerkzeug und einer Abrichtvorrichtung,

Fig. 1b

eine schematische Darstellung eines Schleifenvorgangs eines Werkstücks in einer Seitenansicht, wobei die dargestellte Abrichtvorrichtung außer Eingriff ist,

Fig. 1c

eine schematische Darstellung einer Anordnung aus einem Werkstück und einem Schleifwerkzeug in einer Seitenansicht vor Beginn eines Schleifvorgangs,

Fig. 1d

eine schematische Darstellung einer Anordnung aus einem Werkstück und einem Schleifwerkzeug in einer Seitenansicht während eines Schleifvorgangs,

Fig. 2a

ein erstes bevorzugtes Ausführungsbeispiel einer Abrichtvorrichtung in einer perspektivischen, schematischen Darstellung,

Fig. 2b

ein zweites bevorzugtes Ausführungsbeispiel einer Abrichtvorrichtung in einer perspektivischen, schematischen Darstellung,

Fig. 3

eine perspektivische, schematische Darstellung einer Anordnung aus einem Schleifwerkzeug und zwei Abrichtvorrichtungen in einer ersten Ausführungsform,

Fig. 4a

eine schematische Darstellung einer Anordnung aus einem Schleifwerkzeug und mehreren Abrichtvorrichtungen in einer zweiten Ausführungsform in einer Seitenansicht,

Fig. 4b

eine schematische Darstellung einer Anordnung aus einem Schleifwerkzeug und mehreren Abrichtvorrichtungen in einer dritten Ausführungsform in einer Seitenansicht,

Fig. 4c

eine schematische Darstellung einer Anordnung aus einem Schleifwerkzeug und mehreren Abrichtvorrichtungen in einer vierten Ausführungsform in einer Seitenansicht,

Fig. 5

eine schematische, vergrößerte Darstellung eines Teils einer Abrichtvorrichtung,

Fig. 6a

eine schematische Darstellung des Abrichtschritts des Profilierens eines Schleifwerkzeugs mittels einer Abrichtvorrichtung in einer Seitenansicht,

Fig. 6b

eine schematische Darstellung des Abrichtschritts des Schärfens eines Schleifwerkzeugs mittels einer Abrichtvorrichtung in einer Seitenansicht, und

Fig. 7

ein Verfahren zum Abrichten eines Schleifwerkzeugs, welches zur Bearbeitung eines Werkstücks eingesetzt wird, mittels wenigstens einer Abrichtvorrichtung in einer schematischen Darstellung.

Further details and advantages of the invention are explained in more detail below on the basis of the description of the figures with reference to the drawings. Show in it:

Fig. 1a

a perspective, schematic representation of an arrangement of a workpiece, a grinding tool and a dressing device,

Figure 1b

a schematic representation of a grinding process of a workpiece in a side view, wherein the illustrated dressing device is disengaged,

Figure 1c

a schematic representation of an arrangement of a workpiece and a grinding tool in a side view before the start of a grinding process,

Fig. 1d

a schematic representation of an arrangement of a workpiece and a grinding tool in a side view during a grinding process,

Fig. 2a

a first preferred embodiment of a dressing device in a perspective, schematic representation,

Figure 2b

a second preferred embodiment of a dressing device in a perspective, schematic representation,

Fig. 3

a perspective, schematic representation of an arrangement of a grinding tool and two dressing devices in a first embodiment,

Figure 4a

a schematic representation of an arrangement of a grinding tool and several dressing devices in a second embodiment in a side view,

Figure 4b

a schematic representation of an arrangement of a grinding tool and several dressing devices in a third embodiment in a side view,

Figure 4c

a schematic representation of an arrangement of a grinding tool and several dressing devices in a fourth embodiment in a side view,

Fig. 5

a schematic, enlarged representation of part of a dressing device,

Figure 6a

a schematic representation of the dressing step of profiling a grinding tool by means of a dressing device in a side view,

Figure 6b

a schematic representation of the dressing step of sharpening a grinding tool by means of a dressing device in a side view, and

Fig. 7

a method for dressing a grinding tool, which is used for machining a workpiece, by means of at least one dressing device in a schematic representation.

Figure 1a shows a grinding tool 2, which is rotatably mounted about an axis of rotation 33. The grinding tool 2 has a groove-shaped grinding profile 14 with which the edge 51 of a workpiece 15 can be ground in the form of a glass pane. The invention is of course not limited to the dressing of a groove-shaped grinding profile of a grinding tool.

The workpiece 15 is adjustable and rotatable in all spatial directions 52. Furthermore, a feed device 16 is provided in which a dressing device 1 is mounted. The dressing device 1 is held in the feed device 16 in a form-fitting manner. In addition, a hold-down device 30 is provided for holding the dressing device 1.

As the Figure 1b shows, the workpiece 15 can be arranged on a carrier 32, for example via holding devices 31, wherein the holding devices 31 and / or the carrier 32 can be adjustable in the spatial directions 52.

How to continue from the Figure 1b As can be seen, the grinding tool 2 can be clamped in a clamping device 28 of a grinding machine 26.

The sequence of Figures 1c and 1d illustrates schematically the process of grinding the edge 51 of the workpiece 15 by means of the grinding tool 2. In the position according to FIG Figure 1c the edge 51 of the workpiece 15 is at a distance from the grinding profile 14 of the grinding tool 2. In the position according to Figure 1d If the grinding profile 14 of the grinding tool 2 is in engagement with the edge 51 of the workpiece 15, material of the workpiece 15 is removed relative to the workpiece 15 by a relative movement of the grinding profile 14 and the abrasive grains 13 contained therein.

According to one in the Figure 2a As shown in the first preferred embodiment, the dressing device 1 has a first dressing area 3 and a second dressing area 4 connected to it, the first dressing area 3 having a first specification for sharpening the grinding profile 14 of the grinding tool 2 and the second dressing area 4 a second specification deviating from the first specification for restoring the grinding profile 14 of the grinding tool 2, and wherein the first dressing area 3 has a larger volume than the second dressing area 4.

The dressing device 1 is essentially cuboid, the length of the dressing device 1 being provided with the reference number 6, the width with the reference number 7 and the thickness with the reference number 8.

The dressing device 1 has a longitudinal axis 5. The two dressing areas 3 and 4 are arranged one behind the other in the direction of the longitudinal axis 5.

According to one in the Figure 2b In comparison to the first preferred embodiment, the dressing device 1 shown in the second preferred embodiment has an additional holding area 9 for holding the dressing device 1 when dressing the grinding tool 2, the holding area 9 being designed without abrasive grain.

Of course, the dressing device 1 according to the first preferred exemplary embodiment can also be held during dressing, for example at the dressing area 3, as shown, inter alia, in FIG Figure 3 you can see.

In the in this Figure 3 In the illustrated embodiment, the feed device 16 comprises a magazine 17 for two dressing devices 1, which are arranged one behind the other in the magazine 17 in the direction of the longitudinal axis 5 of the dressing devices 1. One of the dressing devices 1 protrudes a little from the feed device 16. This dressing device 1 is now first used for dressing the grinding tool 2, specifically until the dressing device 1 is used up to such an extent that it can no longer be held in the feed device 16. Thereafter, the dressing device 1 arranged behind it is used for dressing the grinding tool 2.

The vacancy resulting from this in the magazine 17 can be filled by a further dressing device 1.

According to the Figure 4a The embodiment shown, the feed device 16 comprises a magazine 17, which in comparison to that in FIG Figure 3 illustrated magazine has on the one hand a loading device 27 for reloading the dressing devices 1 and an actuator 25 for advancing the dressing devices 1 in the direction of the grinding tool 2 to be dressed. In the case shown, dressing devices 1 according to the second preferred exemplary embodiment are arranged in the magazine 17. As an alternative or in addition, dressing devices 1 according to the first preferred exemplary embodiment can also be arranged in the magazine 17.

Furthermore, a collecting device 29 is provided in which unused remnants of the dressing devices 1 can be collected. In the case of dressing devices 1 according to the second preferred exemplary embodiment, the remnants essentially consist of the holding areas 9 of the dressing devices 1. If the dressing devices 1 in accordance with the first preferred exemplary embodiment are concerned, the remnants essentially consist of sections of the dressing areas 3 and / or 4.

Figure 4b shows an embodiment in which the feed device 16 can be adjusted via a manual feed 18, for example in the form of a spindle drive, in the direction of the grinding tool 2 or in the opposite direction.

Figure 4c shows an embodiment in which the dressing devices 1 can be conveyed fully automatically from the magazine 17 into an active dressing position by means of an actuator 25 which is actuated by an automatic feeder. Furthermore, a detection device 24 is provided with which the stock of dressing devices 1 in the magazine 17 can be detected. Finally, a control and / or regulating device 20 is provided, which communicates at least with the detection device 24 and the delivery machine 19.

Figure 5 shows a schematic, enlarged illustration of part of a dressing device 1. The dressing area 4 comprises a specification for Restoration of the grinding profile of a grinding tool, this specification having a porosity in the range of 10 to 15 percent by volume and a mixture of white aluminum oxide and pink aluminum oxide and / or red aluminum oxide as abrasive grain with a grain size of approx. 55 mesh. The dressing area 3 comprises a specification for sharpening the grinding profile of a grinding tool, this specification having an average pore size of approx. 350 μm and white corundum as abrasive grain with a grain size of approx. 180 mesh.

In the Figure 6a the dressing step of profiling a grinding tool 2 with a dressing device 1 is shown schematically, wherein the grinding tool 2 comes into contact with the dressing area 4. The dressing area 4 is used up until the grinding tool 2 comes into contact with the dressing area 3 (cf. Figure 6b ) and the sharpening dressing step takes place automatically. It is advisable to repeat the method step of restoring the grinding profile of a grinding tool with a frequency N1 and the method step of sharpening with a frequency N2, where N1 <N2.

The change from restoring the grinding profile to sharpening is also shown again schematically in the upper part of the Figure 7 shown. The lower part of the Figure 7 illustrates the option that the grinding tool 2 can be used before the first method step 11, and / or between the first and second method step 11 and 12, and / or after the second method step 12, and / or between a possibly provided repetition of the first or second method step 11 and 12 can be used several times for grinding at least one workpiece 15, preferably a sheet of glass.

Claims (12)

1. Dressing device (1) for dressing a grinding tool (2) provided with a predetermined grinding profile (14), the dressing device (1) comprising at least a first dressing area (3) and a second dressing area (4) connected thereto, the dressing device (1) having a longitudinal axis (5), and both dressing areas (3, 4) are arranged one behind the other in the direction of the longitudinal axis (5), characterized in that the first dressing area (3) has a first specification for sharpening the grinding profile (14) of the grinding tool (2) and the second dressing area (4) has a second specification deviating from the first specification for restoring the grinding profile (14) of the grinding tool (2), and wherein the first dressing area (3) has a larger volume than the second dressing area (4),
   and in that
   the dressing device (1) is essentially cuboid, preferably with

   - a length (6) from 150 mm to 250 mm, particularly preferably from 180 mm to 200 mm, and/or

   - a width (7) from 25 mm to 75 mm, particularly preferably 50 mm, and/or

   - a thickness (8) from 2.0 mm to 10.0 mm, particularly preferably 3.0 mm, 4.0 mm or 5.5 mm.
2. Dressing device (1) according to claim 1, wherein the volume of the first dressing area (3) is about 4 to 7 times, preferably about 6 times, greater than the volume of the second dressing area (4).
3. Dressing device (1) according to one of claims 1 or 2, wherein the first specification

   - has an average pore size from 200 to 500 µm, preferably 350 µm, and/or

   - has white corundum as abrasive grain, and/or

   - has an abrasive grain with a grain size from 120 to 220 mesh, preferably 180 mesh.
4. Dressing device (1) according to any one of claims 1 to 3, wherein the second specification

   - has a porosity in the range from 10 to 15 percent by volume, and/or

   - has a mixture of white corundum and pink corundum and/or red corundum as abrasive grain, and/or

   - has an abrasive grain with a grain size from 35 to 100 mesh, preferably 55 mesh.
5. Dressing device (1) according to one of claims 1 to 4, wherein the dressing device (1) has a holding area (9) for holding the dressing device (1) when dressing the grinding tool (2), preferably wherein

   - the holding area (9) is designed without abrasive grain, and/or

   - is glued on or sintered, and/or

   - consists essentially of a water-soluble material.
6. Method (10) for dressing a grinding tool (2) by means of at least one dressing device (1) according to one of the preceding claims, comprising a first method step (11) in which the grinding profile (14) of the grinding tool (2) is restored by means of the second dressing area (4) of the at least one dressing device (1), and a second method step (12) in which the grinding profile (14) of the grinding tool (2) is sharpened by means of the first dressing area (3) of the at least one dressing device (1).
7. Method (10) according to claim 6, wherein the first method step (11) is repeated with a first frequency N1 before carrying out the second method step (12) and the second method step (12) after completion of the first method step (11) repeated with the frequency N1 is repeated with a second frequency N2, wherein N1 < N2.
8. Method (10) according to claim 6 or 7, wherein the first method step (11) is carried out or repeated before carrying out the second method step (12) until at least a predominant part of the second dressing area (4) is used up, and the second method step (12) is carried out or repeated after completion of the first method step (11) until at least a predominant part of the first dressing area (3) is used up.
9. Method (10) according to any one of claims 6 to 8, wherein the grinding tool (2) before the first method step (11), and/or between the first and second method step (11, 12), and/or after the second method step (12), and/or between an optionally provided repetition of the first or second method step (11, 12) is used several times for grinding at least one workpiece (15), preferably a glass pane.
10. Method (10) according to any one of claims 6 to 9, wherein the dressing device (1) has a holding area (9) for holding the dressing device (1) when dressing the grinding tool (2) and the at least one dressing device (1) at least during the first and second method step (11, 12) is held at least at the holding area (9) in a feed device (16).
11. Method (10) according to any one of claims 6 to 10, wherein the method (10) is carried out sequentially with several successive dressing devices (1), wherein a further dressing device (1), preferably from a magazine (17), is fed, as soon as a previous dressing device (1) is at least for the most part used up.
12. Method (10) according to any one of claims 6 to 11, wherein the method (10) is at least for the most part automated.

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