| 摘要 |
PURPOSE:To execute the hardening of the substance to be worked having small heat capacity so as to make the both surfaces thereof equal to each other in the hardness and depth by simultaneously hardening the both surfaces by irradiating one surface and place opposite to another surface with bisected laser beams. CONSTITUTION:A laser beam is bisected by reflecting surfaces 44 and 45 with a ridgeline 43 of a beam splitter 42 as a boundary. The laser beams reflected on the reflecting surfaces 44 and 45 is reflected by scanner mirrors 50 and 51, and heating and hardening are executed while the spring surfaces on both sides of the substance S to be worked are scanned. By the conventional method by which heating and hardening are executed by one side, heat is conducted to the opposite side since the substance to be worked is thin at the time of secondary heating by laser beams, and the previously hardened part is tempered. Since it is executed both to the front and back surfaces simultaneously, tempering is not generated, the applied heat conducts to the interior, and the hardened depth is made high. |
