4hw.com.cn: how much do you know about the recessive functions of cars? Have you noticed that behind the central rear-view mirror of the front windshield, there are small black spots on the glass, and there is a circle of black edges around the windshield. Why should good glass make these small black spots and black edges on it? What's the effect?
1. Improve glass clarity
The production environment of the front windshield needs to be heated to 280-350 ℃. If the temperature transmission is uneven during the heating process, it will cause the front windshield to deform and affect the optical performance, which is very unfavorable for us to grasp the distance between the obstacles in front, and the driving safety will not be guaranteed naturally. (you can use your brain to mend the mirror.)
The problem can be solved by making the heat conduction more uniform by using the high thermal conductivity of black spots, so that the front glass can be made clearer.
2. Improve glass durability
The glass that has just been filled with boiling water is likely to break down after washing under cold water. It is very common for a sudden rainstorm after direct heat in summer, but I have never heard that the front screen glass will burst because of this reason. In fact, this is also the credit of these black spots.
Black heat absorption, through these black spots of different sizes to absorb and store heat, let the heat evenly transfer to the middle of the glass, can effectively prevent the front glass from bursting.
3. Protect vision
The coverage area of black spots in many cars is not arbitrary. After accurate calculation and design by the manufacturer, these black spots can reduce the direct sunlight to the eyes as much as possible without hindering the driver's vision, so as to reduce the damage of strong light to the glasses, which also helps to alleviate driving fatigue.
4. Black technology in Tibet
This is only for high-end cars. For example, the automatic driving camera, sun rain sensor, automatic wiper sensor, etc. are usually hidden in these black spots. Because they are all black, they will not appear abrupt.
The car owner who has replaced the black edge on the front windshield may know that the front windshield is fixed with rubber strip and sealing glue, mainly to prevent rain water and reduce wind noise, but the main material of the sealant strip is polyurethane, which is not heat-resistant, and the ultraviolet light in the sun can easily aging it.
The black edge is used to cover the sealant strip to avoid direct sunlight, which also slows down the aging progress of the strip. The rough surface of the black edge can further improve the viscosity of the sealant and improve the water resistance of the front windshield. At the same time, the use of black edge to block the traces of glue can also improve the appearance.