Patent Grant
7727337
The present invention relates generally to a chemical method for cleaning stamping or other work piece deformation tools by removing locally adhered build-up of work piece metal.
It is well known that steel tools used for extruding metals such as aluminum can collect substantial amounts of aluminum or other work piece metal within the cavities after the completion of the extrusion process. These tools are typically cleaned by immersing them in warm caustic solutions for several days to dissolve the aluminum without affecting the steel tooling. While this method works well for the aluminum extrusion industry, it is impractical with stamping tools due to the length of time required for cleaning and the relatively small amounts of aluminum and/or other metals remaining in localized regions on the stamping tools after use. Currently, tooling used for stamping at room temperature is hand wiped to remove buildup. An alternative approach is to cool the tool to room temperature and then polish with sandpaper and diamond paste. The problem with this approach is that some of the ferrous tooling material in the vicinity of the aluminum that is built up is also removed which can locally change dimensions or deformation conditions like friction, both of which are critical for part forming and dimensional control. Additionally, if the tool is coated for some desirable characteristics, there is a danger that some of this coating could get damaged or removed.
This invention is believed to provide advantages and alternatives over prior practices by providing a method of cleaning stamping and other metal forming tools which utilizes localized application of a solution of caustic character in the form of basic or mild acid compositions that only attack the buildup (depending on the metal being formed) to remove metal buildup within a few minutes. This avoids the necessity of taking the tool off line or applying aggressive shape-deforming treatments.
The accompanying drawings which are incorporated in and which constitute a portion of this specification illustrate an exemplary practice according to the present invention wherein;
While embodiments of the invention have been illustrated and generally described above and will hereinafter be described in connection with certain potentially preferred procedures and practices, it is to be understood and appreciated that in no event is the invention to be limited to such embodiments and procedures as may be illustrated and described herein. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the broad principles of the invention within the true spirit and scope thereof.
While the following description will be presented in terms of a stamping operation, it is to be understood that reference to such a stamping operation is intended to be illustrative only and that practice of the invention is in no way limited to stamping tools. To the contrary, it is contemplated and intended that the inventive cleaning practices may be equally applicable to any number of forming tools that apply controlled deformation to a work piece including cutting tools, extrusion tools and the like as will be well known to those of skill in the art.
Reference will now be made to the various drawings wherein to the extent possible, like elements are designated by corresponding reference numerals in the various views. In
According to potentially preferred practices, the caustic material may be either basic or acidic in nature. By way of example only, and not limitation, exemplary caustic compositions include NaOH, KOH, acetic acid, phosphoric acid and chemicals with similar caustic properties, and any combination of such materials depending on the adhered material and the tooling material used. By way of example only, and not limitation one caustic material that has been found to be effective is a gel marketed under the trade designation DRANO®. In accordance with a particularly preferred practice, the cleaning operation may be performed at slightly elevated temperatures such as 50-100° C. in order to accelerate the reaction.
The present method is believed to be particularly beneficial for cleaning ferrous stamping tools with deposits from aluminum and aluminum alloy metal work pieces. However, the practice can also be applied to clean other tooling materials including ceramics and the like and other work piece metals that stick to such tooling including magnesium, titanium, zinc coatings on steel and the like. The composition of the cleaning agent preferably in gel form is tailored such that it is reactive to the adhered material and has no reaction with the tooling material, which can be steel or another material suitable for tooling.
It is to be understood that while the present invention has been illustrated and described in relation to potentially preferred embodiments, constructions, and procedures, that such embodiments, constructions, and procedures are illustrative only and that the invention is in no event limited thereto. Rather, it is contemplated that modifications and variations embodying the principals of the invention will no doubt occur to those of skill in the art. It is therefore contemplated and intended that the present invention shall extend to all such modifications and variations as may incorporate the broad aspects of the invention within the true spirit and scope thereof.
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|---|---|---|---|
| 3033710 | Hightower et al. | May 1962 | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20080083426 A1 | Apr 2008 | US |
