| 摘要 |
PURPOSE:To form a dimple whose dimension is micronized or whose arrangement is randomized on a cooling drum in a working device by which the dimple is formed on the surface of the cooling drum for casting a cast billet by irradiating the surface of the cooling drum with a laser beam. CONSTITUTION:The working device is provided with a laser means 1 which generates the laser beam, a laser exiting means 2 which controls the oscillating frequency and output of the laser beam, an optical path means 3 which is provided with a mirror and a lens to form an optical path system and by which the surface of the cooling drum 5 is irradiated with the laser beam and a working means 4 by which, at least, one dimension of the diameter or position of the dimple formed on the surface of the cooling drum 5 is determined at random in a specific range and an optical path controlling signal is transmitted to the optical path system of the optical path means 3. The optical path system is shifted according to the optical path controlling signal and the irradiating condition of the laser beam on the surface of the cooling drum 5 is changed by the optical path means. |
