The distinction between water and fog of automobile lamps
In recent years, the car has become an important means of transport in people's daily life. With the ever-changing car styling, magnificent lights more and more people's favorite. Today's automotive lighting manufacturing industry, the design, manufacture, technology are becoming more mature, the quality of the lights increasingly perfect. But so far, the lamp fog is still an important reason affecting the quality of the lights.
Here, we must first understand a concept: lamp fog is not equivalent to the lamp into the water.
Lamp water is a quality problem that can be avoided and is not allowed to occur. In the case of normal use, the lamp due to poor sealing caused by internal water failure, will seriously affect the lamp life and circuit safety. Factors that cause quality problems can be summarized as three categories:
① lamp itself, poor design of the seal;
② lamp end and harness end plug between the seal with improper;
③ lamps and body clearance, face difference is bad.
Lamp water problem can be solved by reasonable structural design. Lamp fog is a natural phenomenon, but the fog will be lighting and lighting of the internal circuit, lamp beads life and appearance have a certain impact, so through the rational design of the lamp structure to reduce the fog caused by the impact of lighting. From another point of view, although the fog lamps meet regulatory requirements, but the market is not satisfied, that is, the direction of quality improvement.
Simply put, the formation of fog and lamp air contained in the high concentration of water vapor.
Good sealing of the lamps, there will be no leakage phenomenon, then why the water contained in the air vapor concentration will be high? This is related to the "breathing" of the lamp. The inspiration of the lamp is the most important and often overlooked. In the rainy day or car wash process, when the lights go out and the rain is not stopped, the lamp in the rain erosion, the lamp chamber temperature suddenly dropped, resulting in negative pressure forced waterproof tape or seal glue under pressure from weak or thin Deformation, forced suction, for better air tightness of the lamps, the water is basically concentrated in the suction process. By the inlet position, gap size, rainfall size and many other factors, good air tightness in the light when the rain is not stopped when the probability of inhalation of rain 5% to 8%, and with the increase in the number of years and waterproof tape Aging and increased. This situation often appears on the front fog lights and headlights.
When the ambient temperature is lower than the critical temperature of water vapor condensation, if the water vapor within the lamp can not flow enough to spread to the external environment, when the water temperature in the lamp is higher than that in the ambient temperature, , Still maintain a high concentration, the lamp within the water vapor condensation - in the lamp glass surface to form a film and beads-like condensation, that is fog phenomenon.