Rough grinding wheel comprising a core

Abstract

A rough grinding wheel for processing material surfaces includes a wheel-shaped base body having a central recess penetrated by an axis of rotation for direct or indirect connection to a drive shaft of a tool. The rough grinding wheel has a stabilizing core stabilizing the rough grinding wheel. The stabilizing core is associated with at least one abrasive layer circumferentially adjacent to the central recess. The stabilizing core has a higher strength than the at least one abrasive layer.

Claims

1. A rough grinding disk comprising: a disk-shaped base body comprising a central recess and further comprising a reinforcing layer; at least two abrasive layers supported by the reinforcing layer; and a stabilizing core associated with the abrasive layers, circumferentially adjacent the central recess and having a higher strength than the abrasive layers, the stabilizing core comprising at least two core segments, the at least two core segments corresponding to and having the same thickness as the associated abrasive layers, wherein a separating layer is arranged between the abrasive layers and the corresponding core segments, the separating layer extending continually along a length of the abrasive layers and corresponding core segments, wherein the core segments define the stabilizing core and are separated by the separating layer.

2. The rough grinding disk according to claim 1, in which a ratio of an outer radius of the stabilizing core to an outer radius of the rough grinding wheel is between 2:50 and 25:50.

3. The rough grinding disk according to claim 2, in which the ratio of the outer radius of the stabilizing core to the outer radius of the rough grinding wheel is about 17:50.

4. The rough grinding disk according to claim 1, in which the stabilizing core has a constant outer radius across its thickness.

5. The rough grinding disk according to claim 1, in which the stabilizing core is continuous around the central recess.

6. The rough grinding disk according to claim 1, in which the central recess is a recessed hub.

7. The rough grinding disk according to claim 1, in which the at least two abrasive layers include abrasive grits.

8. The rough grinding disk according to claim 7, in which the abrasive grits is selected from a group consisting of regular brown fused alumina and derivatives, blue fired alumina, white fused alumina, zirconia alumina, silicon carbide, ceramic grain, pink fused alumina, and monocrystalline alumina.

9. The rough grinding disk according to claim 7, in which the abrasive grits includes supporting fillers selected from a group consisting of polyaluminum fluoride, cryolite, pyrite, calcite, wollastonite, and graphite.

10. The rough grinding disk according to claim 7, in which the abrasive grits is bonded by a phenolic resin system.

11. The rough grinding disk according to claim 1, in which the at least one separating layer includes a glass fabric.

12. The rough grinding disk according to claim 1, wherein an axis of rotation for direct or indirect connection to a drive shaft of a tool extends through the central recess.

13. The rough grinding disk according to claim 1, wherein the stabilizing core comprises phenolic resin-bonded rutile, wollastonite, calcite, and basalt.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a section through a rough grinding wheel incorporating the present invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

(2) The rough grinding wheel 1 illustrated in the drawing comprises a base body 3 having a layered structure. The base body 3 comprises a central recess 2 penetrated by an axis of rotation 5 located in the center of rotation of the rough grinding wheel 1. An insert 4 for attaching the rough grinding wheel 1 to a drive shaft of a tool is arranged in the recess 2. A reinforcing layer 6 is arranged on the tool side of the rough grinding wheel 1 facing toward the tool. The reinforcing layer 6 may comprise rutile, wollastonite, calcite and/or basalt, which may be phenolic resin-bonded. A grain size may be between 0.1 mm to 1.0 mm, preferably between 0.2 mm and 0.5 mm. Furthermore, the reinforcing layer 6 may comprise quartz sand. Thus, the reinforcing layer 6 has high strength. It may comprise a net-like interlining in order to further increase the stability of the rough grinding wheel 1.

(3) Furthermore, the rough grinding wheel 1 comprises two abrasive layers 8a, 8b arranged on the side facing away from the tool side of the reinforcing layer 6. The abrasive layers 8a, 8b may comprise abrasive grits, such as regular brown fused alumina and derivatives, blue fired alumina, white fused alumina, zirconia alumina, silicon carbide, ceramic grain, pink fused alumina and/or monocrystalline alumina. Furthermore, the abrasive layers may comprise supporting fillers, such as polyaluminum fluoride, cryolite, pyrite, calcite, wollastonite and/or graphite, which may be bonded by means of phenolic resin systems. Thus, a phenolic resin/abrasive grain mixture is formed, which may contain various fillers and additives. A separating layer 10 is arranged between the two abrasive layers 8a, 8b. Furthermore, another separating layer 10 is arranged between the reinforcing layer 6 and abrasive layer 8a. Each of the separating layers 10 is formed by a glass tissue layer and benefits the strength of the rough grinding wheel 1. The separating layers 10 extend from an outer edge of the rough grinding wheel 1 to the central recess 2 and annularly surround the central recess 2.

(4) Furthermore, the rough grinding wheel 1 comprises a stabilizing core 12 surrounding the axis of rotation 5 of the rough grinding wheel 1 and being adjacent to the central recess 2 and, in sections, forming the edge of the central recess 2. The stabilizing core 12 may comprise rutile, wollastonite, calcite and/or basalt, which may be phenolic resin-bonded. A grain size may be between 0.1 mm to 1.0 mm, preferably between 0.2 mm and 0.5 mm. Furthermore, the reinforcing layer 6 may comprise quartz sand. The stabilizing core 12 has higher strength than the abrasive layers 8a, 8b. The stabilizing core 12 is formed by two core segments 12a, 12b and serves as a force transmission element between the two abrasive layers 8a, 8b and the connection to the drive shaft of the tool.

(5) A core segment 12a, 12b of the stabilizing core 12 is associated with each abrasive layer 8a, 8b. Core segment 12a is arranged between two separating layers 10 adjacent thereto. Core segment 12b is adjacent to a separating layer 10 at the tool side and is open, i.e. not covered by a separating layer 10, at the side facing the work piece. In consequence, the separating layers 10 divide the stabilizing core 12 into two core segments 12a, 12b. The two adjacent core segments 12a, 12b are connected to each other via the interposed separating layer 10 and define the stabilizing core 12.

(6) The outer radius a of the stabilizing core 12 has a ratio of 17:50 to the outer radius b of the rough grinding wheel 1. Furthermore, the stabilizing core 12 has a constant radius across its thickness and in the axial direction of the rough grinding wheel 1.

(7) To ensure an optimal connection to a tool, the central recess 2 is realized as a recessed hub.