PURPOSE: To construct fins having good radiation performance by folding the side section of a radiation fin parallel with the air flow while arranging a plurality of band type raising sections, where the sides facing against the air flow are raised and opened on the radiation fin around the side and the rear section of the anode side section, and fixing them to the folded side section of the fin.
CONSTITUTION: Since raising sections 11 are provided, the pressure loss of the air flow passing through said sections 11 will increase while simultaneously the air flow will decrease thereby the wind flow at the section provided with no raising sections 11 will increase correspondingly. Consequently, the air flow toward the center of a radiation fin 9 is induced gradually at the rear stream side of an anode or a fin collar thus the dead water area 13 reduces considerably. Since the foot part of the raising section 11 has obliquely constructed joint side 14 to provide an elevation angle against the air flow, the air flow will vary abruptly at the foot part to cause turbulence, increasing the heat conductivity. While since the raising sections 11 are connected to the side section 10 of the fin, the efficiency of fin radiation is improved, lowering the entire thermal resistance of the fin 9 resulting in reduction of the temperature nonuniformity around the anode.
AKUTAGAWA RYUTARO
ASO SHINICHI
TAKEGAWA HIROZO
ADACHI MASAAKI
