Method of manufacturing an abrasive tool

Abstract

 A method for manufacturing an abrasive tool (1), comprising the steps that consist in:
- depositing, on a working surface (2a) formed on a metallic supporting body (2), an abrasive powder (3);
- heating the working surface (2a) and the abrasive powder (3) to a temperature above 400°C;
- pressing the abrasive powder (3) against the working surface (2a) with a pressure of more than 0.75 t/cm²;
- cooling the metallic supporting body (2) in oil in a time comprised between 2.5 minutes and 10 minutes.

Description

[0001] The present invention relates to a method for manufacturing an abrasive tool.

[0002] Typically, abrasive tools are constituted by a metallic supporting body, which is for example disk-shaped and has a working surface that supports the abrasive powder.

[0003] The supporting body is mounted on a machine tool, for example a sanding machine, which transmits to the tool a motion, typically a cyclic, linear, oscillating or rotary motion, so as to move the working surface into contact with the part to be machined.

[0004] The tool can also be stationary, such as for example a lathe tool.

[0005] Known abrasive tools, for example backing pads, are constituted by a metallic supporting body, typically made of steel, that has a working surface covered by a layer of abrasive powders (for example diamond powder) mixed with a bonding substance, such as for example an adhesive.

[0006] Although these constructive solutions are used extensively, they are not free from drawbacks.

[0007] First of all, the use of bonding agents leads to a lower efficiency of the abrasive capacity of the working surface.

[0008] Secondly, in order to ensure a stable grip of the abrasive powder and of the bonding agent to the working surface, supporting bodies made of steel of considerable weight are often used: this causes an increase in the operating costs of the abrasive tool as well as vibrations.

[0009] The aim of the present invention is to eliminate or at least reduce drastically the drawbacks described above.

[0010] Within this aim, an object of the invention is to provide a method for manufacturing an abrasive tool that makes it possible to obtain an abrasive tool without using bonding agents or adhesives.

[0011] A further object of the invention is to provide a method for manufacturing an abrasive tool that is extremely lightweight, so as to reduce the operating costs and the risk of the onset of vibrations.

[0012] This aim, as well as these and other objects that will become more apparent hereinafter, are achieved by a method for manufacturing an abrasive tool according to claim 1.

[0013] Further characteristics and advantages of the invention will become more apparent from the description of some preferred but not exclusive embodiments of a method for manufacturing an abrasive tool according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a sectional view of an abrasive tool obtained by means of the method according to the invention.

[0014] The present invention relates to a method for manufacturing an abrasive tool, generally designated by the reference numeral 1. The method comprises:

• a step of depositing, on a working surface 2a formed on a metallic supporting body 2, an abrasive powder 3;
• a step of heating the working surface 2a and the abrasive powder 3 to a temperature above 400 °C;
• a step of pressing the abrasive powder 3 against the working surface 2a at a pressure of more than 0.75 t/cm²;
• a step of cooling the metallic supporting body 2 in oil in a time comprised between 2.5 minutes and 10 minutes.

[0015] Advantageously, the abrasive powder 3 is selected from the group that comprises:

• diamond powder;
• synthetic diamond powder;
• super-abrasive powder;
• molten carbides of tungsten, titanium, tantalum (widia);
• zirconium;
  or mixtures thereof.

[0016] Conveniently, the metallic supporting body 2 is made of aluminum or alloys thereof.

[0017] It has been found that it is particularly advantageous for the heating step to comprise heating to a temperature above 520 °C and preferably comprised between 545 °C and 555 °C.

[0018] The step of pressing the abrasive powder against the working surface is performed preferably at a pressure of more than 1.45 t/cm² and preferably substantially equal to 1.50 t/cm².

[0019] By way of example, the heating step can be performed at a temperature comprised between 400 °C and 600 °C while the pressing step provides for a pressure comprised between 0.75 t/cm² and 2 t/cm².

[0020] In this regard it has been observed experimentally that by increasing the temperature at which the heating step is performed it is possible to use pressures that correspond to the lowest values of the range cited above, whereas by decreasing the temperature at which the heating step is performed it is necessary to use pressures that correspond to the highest values of the range cited above.

[0021] Advantageously, the step of cooling the metallic supporting body 2 in oil is performed in a time comprised between 4 minutes and 6 minutes and preferably over a time substantially equal to 5 minutes.

[0022] As shown, the method according to the invention has been found to be extremely satisfactory for the production of abrasive tools 1 of any shape and type, such as, merely by way of example, backing pads, cutters (cylindrical, spherical, conical, etc.), files, floats, including fixed ones, etcetera.

[0023] According to a further aspect, the present invention relates to an abrasive tool 1 that is provided by means of a method according to what has been described above.

[0024] All the characteristics of the invention indicated above as advantageous, convenient or the like may also be omitted or be replaced with equivalents.

[0025] The individual characteristics presented with reference to general teachings or to particular embodiments may all be present in other embodiments or may replace characteristics in these embodiments.

[0026] In practice it has been found that the invention has achieved the intended aim and objects in all of its embodiments.

[0027] In particular, it has been found that an abrasive tool 1 obtained by means of the method according to the invention has a significantly longer life than currently commercially available tools.

[0028] Moreover, by using the process parameters cited above it has been found surprisingly that it is possible to fix the abrasive powder to a metallic body made of aluminum or aluminum alloy, thus reducing the vibrations and overheating of the abrasive tool during its use.

[0029] All the details may further be replaced with other technically equivalent elements.

[0030] In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements and to the state of the art.

[0031] The disclosures in Italian Patent Application no. VR2012A000097, from which this application claims priority, are incorporated herein by reference.

[0032] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A method for manufacturing an abrasive tool (1), comprising the steps that consist in:

- depositing, on a working surface (2a) formed on a metallic supporting body (2), an abrasive powder (3);

- heating said working surface (2a) and said abrasive powder (3) to a temperature above 400 °C;

- pressing said abrasive powder (3) against said working surface (2a) with a pressure of more than 0.75 t/cm²;

- cooling said metallic supporting body (2) in oil in a time comprised between 2.5 minutes and 10 minutes.

2. The method according to claim 1, characterized in that said abrasive powder (3) is selected from the group that comprises:

- diamond powder;

- synthetic diamond powder;

- super-abrasive powder;

- molten carbides of tungsten, titanium, tantalum (widia);

- zirconium;
or mixtures thereof.

3. The method according to one or more of the preceding claims, characterized in that said metallic supporting body (2) is made of aluminum or alloys thereof.

4. The method according to one or more of the preceding claims, characterized in that said heating step comprises heating to a temperature above 520 °C and preferably comprised between 545 °C and 555 °C.

5. The method according to one or more of the preceding claims, characterized in that said step of pressing said abrasive powder (3) against said working surface (2a) is performed at a pressure of more than 1.25 t/cm² and preferably substantially equal to 1.50 t/cm².

6. The method according to one or more of the preceding claims, characterized in that said step of cooling said metallic supporting body (2) in oil is performed in a time comprised between 4 minutes and 6 minutes and preferably in a time substantially equal to 5 minutes.

7. The method according to one or more of the preceding claims, characterized in that said abrasive tool (1) is selected from the group that comprises:

- a backing pad;

- a cutter (cylindrical, spherical, conical, etcetera);

- a file;

- a float;
or the like.

8. An abrasive tool (1) provided by means of a method according to one or more of claims 1 to 6.

Drawing