WO2011141500A1 - Grinding disc - Google Patents

Abstract

The present invention relates to a grinding disc which comprises a carrier (1), which is drilled through in the centre (6) for mounting purposes, and a working region (2) which forms the outer edge of the grinding disc (7) and has at least two different annular abrasive coatings (3) and (4) which are interconnected so as to adjoin one another, wherein the outer annular abrasive coating (4) is a coarse grain coating and the inner abrasive coating (3) is a fine grain coating.

Description

 grinding wheel

The present invention relates to a grinding wheel having a working surface with two different abrasive coatings.

A grinding wheel can be in various forms. The most widely used grinding wheels consist of a superposition of the following three components, namely a rigid support on which a layer of abrasive particles is arranged, which are secured to the support by at least one or two layers of binder. These materials are then cut to the desired circular shape and pierced in the middle with an opening which their attachment by tightening on the shaft of a

Tool allowed.

Further grinding wheels consist of a rigid support, which is provided at the edge with a working area in which hair or brushes, which are for example made of metal and distributed such that the plane passing through the working area parallel to the grinding wheel plane or perpendicular to the axis of rotation of Grinding wheel is after it has been attached to the tool.

Other grinding wheels consist of a rigid support and are provided at the edge in their work area with lamellae, which consist of conventional abrasives. The lamellae are secured to the circumference of the grinding wheel with one edge, their opposite free edges forming grinding edges. They are inclined and sufficiently close to each other to partially overlap in a given amount.

The choice of grinding wheel depends on the nature of the material to be ground, such as wood, plastic, composite or metal and the amount of material to be removed. From US 3,628,292 A a grinding wheel is known which is provided with a coating containing abrasive grains in a resin binder. The grinding wheel is provided with brushes and cavities which alternate radially.

From US 5,197,249 A a segmented grinding wheel is known, from

Abrasive contains free areas to extend the life of the grinding wheel.

The object of the present invention is to provide a grinding wheel with a work surface with which can be ground quickly and with a good surface is achieved.

The present invention is achieved by a grinding wheel having a carrier pierced for attachment in the center and comprising a working area forming the outer periphery of the grinding wheel and having at least two different annular abrasive coatings joined together adjacent to each other the outer annular abrasive coating contains coarse grain and the inner abrasive coating contains fine grain.

A preferred embodiment of the invention is a grinding wheel, wherein an abrasive coating has a coarse grain of D64 to D126 and an abrasive coating has a fine grain of D15 to D46.

Another preferred embodiment of the invention is a grinding wheel wherein an abrasive coating has a coarse grain of D46 to D151 and an abrasive coating has a fine grain of D7 to D76.

The areas for the grain size correspond approximately to the dimension micrometer (μιτι). The grain sizes are reported according to the Federation of European Producers of Abrasives (FEPA). The numbers are preceded by the letters D for diamond or B for Borazon. The particle size specifications given here correspond to DIN ISO 6106. Table 1 below discloses how the indicated grain sizes can be related to other applicable units:

Table 1

A preferred embodiment of the invention is a grinding wheel, wherein the working area has a combination of an abrasive coating with D64 to D91 coarse and an abrasive coating with D25 to D46 fine.

A preferred embodiment of the invention is a grinding wheel, wherein the abrasive coatings phenolic resin, polyamide resin, metal powder ver, diamond or boron nitride, in particular borazon contain. Thermally curable binders include phenolic resins, epoxy resins, and alkyd resins. The metal powder is preferably an aluminum powder, a copper powder, a nickel powder or an alloy comprising at least aluminum, copper or nickel. The metal powder is particularly preferably a copper-containing alloy and in particular an alloy of copper and tin, namely a bronze powder. The abrasive article to be used may be included in the formulation prior to application or may be applied to the formulation

 Binder layer are applied after their application and before curing. The abrasive article is incorporated into the formulation in an amount of up to about 50% by weight of the formulation prior to application.

The abrasive article may be fired alumina, ceramic alumina, silicon carbide, chromia, alumina, zirconia, diamond, iron oxide, Ceria, cubic boron nitride, boron carbide, garnet, and combinations thereof. Any other synthetic or natural abrasive article known in the art may also be used. The distribution of the abrasive article on the backing layer and its average particle size and size distribution may be conventional. They can be oriented or applied without orientation.

In a particularly preferred embodiment of the invention contains the

Abrasive wheel of 20 wt .-% to 40 wt .-% binder, preferably phenolic resin, from 20 wt .-% to 60 wt .-% metal powder, preferably copper powder and from 20 wt .-% to 50 wt .-% filler, preferably Alumina or silicon carbide. The filler increases the wear resistance of the grinding wheel.

The diamond concentration or borazon concentration of a

The grinding wheel according to the invention is preferably from C75 to C125, which corresponds to 3.3 carats / cm ³ to 5.5 carats / cm ³ .

Boron nitride is constructed under normal conditions analogous to graphite and also very temperature resistant. It only reacts with air at 750 ° C. The diamond-like modification Borazon is the hardest material after diamond.

A preferred embodiment of the invention is a grinding wheel, wherein the carrier is substantially rigid and contains a composite material with at least one plastic such as phenolic resin and / or polyamide resin with reinforcing fibers such as glass fibers or metals such as steel, aluminum or aluminum alloys.

Preferably, aluminum alloys are used. The alloys contain aluminum, magnesium, silicon, iron, copper, manganese, tin, titanium and other metals. Most preferably, the aluminum alloy is used. The alloy has the composition listed in Table 2. Underneath it falls completely

particularly preferred aluminum alloy AlMgSM. A preferred embodiment of the invention is a grinding wheel, wherein the grinding wheel has a diameter of 75 mm to 250 mm, particularly preferably 100 mm to 200 mm. Very advantageous are diameters of 125 mm, 150 mm and 200 mm. Long diameters are achieved with the diameters according to the invention.

Table 2

A preferred embodiment of the invention is a grinding wheel, wherein the covering width of the working range of 2.0 mm to 5.0 mm, preferably from 2.5 mm to 2.9 mm. The work area is advantageously very narrow and fits in the gaps, in particular between teeth of the workpiece to be ground, for example in a circular saw blade.

A preferred embodiment of the invention is a grinding wheel, wherein the outer ßure coating angle of 15 ° to 30 °, preferably from 20 ° to 25 °. With these pad angles, good results are achieved when grinding.

The axial lining depth is according to the invention of 1 mm to 15 mm from 4 mm to 6 mm. The total height of the grinding wheel is according to the invention from 10 mm to 15 mm, preferably from 1 1 mm to 14 mm.

A preferred embodiment of the invention is a grinding wheel, wherein the abrasive coating with coarse grain forms a lower layer, which is horizontally and vertically connected to the carrier in the recess and the abrasive Fine Grain Coating forms an upper layer horizontally bonded to the abrasive coating and vertically to the carrier in the recess.

The present invention is further achieved by a method for producing a grinding wheel, wherein:

a) the support is made with a bore and recess at the edge,

b) the coarse grain abrasive coating is applied as the lower circular layer and is horizontally and vertically bonded to the carrier in the recess and thermally cured,

c) the fine grain abrasive coating is applied as an upper circular layer to the coarse grain abrasive coating and is vertically bonded to the carrier in the recess and thermally cured, and

d) mechanically machining the working area with the outer coarse grain annular abrasive coating and the inner fine grain abrasive coating.

The present invention is further solved by the use of a grinding wheel for grinding breast surfaces, rake faces and ridges of saw teeth in cutting circular saw blades and for use in saw sharpening machines. It is sanded quickly with a grinding wheel and obtained a good surface. Particularly effective can carbide teeth of Trennkreissägeblättern, especially for small gaps between teeth, so-called chip spaces grind.

The grinding wheel according to the invention with two abrasive coatings saves time, with improved flatness of the cutting surface of the

Carbide saw tooth is obtained in circular saw blade. This result was surprising and unexpected.

The invention will be explained in more detail with reference to a drawing and an example. Show it:

1 shows a plan view of a grinding wheel according to the invention, 2 shows a cross-sectional drawing along the line A - A 'in Fig. 1st

The plan view shown in Fig. 1 shows the grinding wheel 7 according to the invention from above. The carrier 1 is preferably made of an aluminum alloy (AlMgSil). The carrier 1 is pierced for mounting in the middle. The bore 6 has a

Diameter of 32 mm. The working area 2 forms the outer edge of the grinding wheel 7. The main components of the working area 2 are phenolic resin, metal powder and abrasive diamond. The work area 2 comprises at least two different annular abrasive coatings 3 and 4. The abrasive coatings 3 and 4 are adjacent to each other and bonded together. The outer annular abrasive coating 4 contains coarse grain. The inner abrasive coating 3 contains fine grain. In FIG. 2, the dimensions, the thicknesses and the geometry of the grinding wheel 7 become clear from the cross section. The coarse grain abrasive coating 3 forms a lower layer horizontally and vertically connected to the carrier 1 in the recess 5. The fine grain abrasive coating 4 forms an upper layer horizontally bonded to the abrasive coating 3 and vertically to the carrier 1 in the recess 5. Clearly visible are the coating width w, the axially measured

Covering depth x and the covering angle of the grinding wheel 7.

example

The inventive grinding wheels S1 was tested. The grinding wheel S1 had a diameter of 125 mm and a bore with a diameter of 32 mm. The height of the grinding wheel S1 was 13 mm. The covering width w of the grinding wheel S1 was 2.5 mm. The axially measured lining depth x the

Grinding wheel S1 was 5.5 m. The coating angle was 25 °. The working area 2 of the grinding wheel S1 contained two abrasive grinding surfaces 3 and 4. Comparative example

Two prior art wheels T1 and T2 of the same dimensions and compositions as abrasive wheel S1 were made. The working range of the grinding wheels T1 and T2, however, contained only an abrasive coating.

The compositions as well as the results of grinding wheels S1, T1 and T2 are shown in Table 3 below.

Table 3

This result was unexpected and surprising to the skilled person.

reference numeral

1 carrier

 2 workspace

 3 abrasive coating

 4 abrasive coating

 5 recess

 6 hole

 7 grinding wheel

 outer covering angle w covering width

 X axially measured pad depth

Claims

claims 1 . Grinding wheel comprising a support (1) for attachment in the middle (6)  is perforated and includes a working area (2) forming the outer edge of the grinding wheel (7) and having at least two different annular abrasive coatings (3, 4) joined together adjacent to each other, the outer annular abrasive  Coating (4) coarse grain and the inner abrasive coating (3) contains fine grain. A grinding wheel according to claim 1, wherein the abrasive coating (3) has a coarse grain of D64 to D126 and the abrasive coating (4) has a fine grain of D15 to D46. 3. Grinding wheel according to claim 1 or 2, wherein the working area (2) has a combination of abrasive coating (3) with D64 to D91 coarse and abrasive coating (4) with D25 to D46 fine. 4. Grinding wheel according to one of claims 1 to 3, wherein the abrasive  Coatings (3, 4) Phenolic resin, polyamide resin, metal powder, diamond or boron nitride, in particular Borazon included. 5. Abrasive wheel according to one of claims 1 to 4, wherein the carrier (1) is substantially rigid and contains a composite material with at least one plastic such as phenolic resin and / or polyamide resin with reinforcing fibers such as glass fibers or metals such as steel, aluminum or aluminum alloys. 6. Grinding wheel according to one of claims 1 to 5, wherein the grinding wheel (7) has a diameter of 75 mm to 250 mm, preferably from 100 mm to 200 mm. 7. Grinding wheel according to one of claims 1 to 6 wherein the covering width of the working area (2) of 2.0 mm to 5.0 mm, preferably from 2.5 mm to 2.9 mm. 8. Grinding wheel according to one of claims 1 to 7, wherein the outer  Coating angle cc of 15 ° to 30 °, preferably from 20 ° to 25 °. 9. Grinding wheel according to one of claims 1 to 8, wherein the abrasive  Coarse grain coating (4) forms a lower layer which is horizontally and vertically connected to the support (1) in the recess (5) and the fine grain abrasive coating (3) forms an upper layer horizontal with the abrasive one Coating (4) and vertically to the carrier (1) in the recess (5) is connected. A method of manufacturing a grinding wheel according to any one of claims 1 to 9, wherein:  a) the carrier (1) with a bore (6) and recess (5) is made at the edge,  b) the coarse grain abrasive coating (4) is applied as the lower circular layer and is horizontally and vertically bonded to the support (1) in the recess (5) and thermally cured,  c) the abrasive coating (3) is applied with fine grain as an upper circular layer on the abrasive coating (4) with coarse grain and vertically with the support (1) in the recess (5) and is thermally cured, and  d) the working area (2) with the outer annular abrasive Coating (4) with coarse grain and the inner abrasive coating (3) is mechanically processed with fine grain. Use of a grinding wheel according to one of claims 1 to 9 for grinding of breast surfaces, rake faces and ridges of saw teeth in Trennkreissägeblättern and for use in Sägenschärfautomaten, which is ground quickly with a grinding wheel and a good surface is obtained.