Mechanical control element having wear-resistant surface
OwnerFriedhelm Reinke, Friedhelm Emdeinventors
Life of this patent
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Abstract
Arrangement for providing an enhanced wear-resistant contact region for a cast iron mechanical control element such as a rocker arm. The control element is cast in a desired shape. It is then preheated to a temperature between room temperature and the Ms temperature of the iron element (Ms temperature is a function of the carbon content of the iron) to adjust the total hardness of the iron element. A surface region of a cast iron control element, intended for forming the contact region, is partially melted and then cooled to create a hard ledeburitic structure which has a mixed crystal structure and is at least partly martensitic and has a mixed hardness of at least 670 Hv.
Claims9
A mechanical control element formed by the following process:
- casting an iron element in a desired shape;
- preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness;
- partially melting a surface region of the control element;
- and
- subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
A method for forming a mechanical control element comprising the following steps:
- casting an iron element in a desired shape;
- preheating the iron element to a temperature up to about the Ms temperature of the iron element to adjust its total hardness;
- partially melting a surface region of the control element;
- and
- subsequently cooling the partially melted surface region to form a fine-grained, essentially ledeburitic structure which has a mixed crystal structure that is at least partly martensitic and has a mixed hardness of at least 670 Hv.
A control element for a control system of an engine, comprising:
- a cast iron element having a contact region for sliding on the surface of a control cam and having a hard, wear-resistant structure with a mixed hardness of at least 670 Hv and a maximum layer thickness of substantially 1 mm, the control element being formed in part by heating it to a temperature up to about its Ms temperature to adjust the total hardness of the element and then providing the contact region with a ledeburitic-martensitic structure by partially melting the surface region and then cooling it.
Dependencies are inferred from the claim text.