| 摘要 |
PURPOSE:To enhance the environmental resistance by making openings in the peripheral surface of a vent pipe projecting to the outside of a cover member thereby enhancing the heat dissipation efficiency in the forced air cooling. CONSTITUTION:Upon operation of a fan 3, cool air is blown directly to each hybrid IC 1. The cool air is also blown directly to the surface of a vent pipe 17 and thereby heat is also dissipated from the surface thereof. Furthermore, air flow generated in the vent pipe 17 dissipates heat from the inner surface thereof. In other words, since the vent pipe 17 is opened at first and second asymmetrical positions and the width of opening occupies 40-50% of the outer diameter of vent pipe 17, any one opening is opened entirely or partially toward the upstream side. Consequently, the air flows through the vent pipe 17 from the opening directing toward the upstream side and leaves the opposite opening. This structure realizes positive heat dissipation from the inner perpheral surface of the vent pipe 17. |
