| 摘要 |
PURPOSE:To prolong the life of a wire dot printer by reducing the advance of the abrasion of a core, by forming a highly hard layer to the load receiving part of a core material without damaging various magnetical characteristics. CONSTITUTION:The core 2 of a wire dot printer head receives repeated load by a leaf spring 6 and is easy to receive abrasion. In order to prevent this obrasion, a highly hard layer 2a is formed to said core 2 by a method wherein a hardening agent such as a carburizing agent or a borating agent containing either one of or two kinds of more of C, B, B4C, Fe-B and Ni-B is preliminarily applied to the upper surface of the core 2 and laser having output suitable for surface hardening is allowed to irradiate the desired position of the formed coating layer in a spot like state to form a layer of Fe3C, FeB or Fe2B. Because it is unnecessary to overheat the whole in this surface hardening treatment by laser and only a specific hardening requiring part can be treated within a short time, the effect to magnetic characteristics is extremely little and no effect is exerted on operational capacity. |
