PURPOSE: To obtain an automobile head lamp provided with a level having less measurement errors even by any temperature change of the circumferential atmosphere of the level by providing a lining member having a satisfactory heat conductivity in opposition to a bubble tube in the casing of the level.
CONSTITUTION: A lining member 100 made of aluminium having satisfactory heat conductivity is disposed on the inside of the casing body 72 of a level 70. This lining member 10 smooths the difference in the conducted heat quantity in each area. The smoothed heat in the lining member is isolated by an air layer interposed between the lining member 100 and a bubble tube 80, further smoothed and conducted to the bubble tube 80. Thus, the heat quantity conducted to the bubble tube 80 is longitudinally uniformed, and the temperature difference between front and rear end parts of the bubble tube 80 becomes less. Therefore, in the bubble tube 80, no convection resulted from the temperature difference is generated, and the movement of bubbles is hardly present.
MOCHIZUKI EIJI
OTSUKA YASUSHI
MIYAZAWA KENJI
