Only inlet and not exhale the valve core
The valve core on the inflatable inner tube, similar to a one-way valve, only allows the gas to enter, does not allow the gas to leak out, can facilitate the intake of air, and ensure the sealing of the inflatable inner tube. Its main body is a hollow upper end and a solid cylinder at the lower end, with a small hole connected to the hollow part on the side of the lower end of the cylinder. A stretch of elastic thin-edge hose is then placed underneath to form the valve core.
When you inflate the bicycle tire, the compressed air in the cylinder enters the elastic hose of the small hole from the hollow part, and the air "tops" the elastic rubber tube, thus entering the tire; when it is not inflated, the elastic rubber tube tightens, covering the small hole on the side, so that the air cannot flow back out of the tire.
On the bicycle, a lot of knowledge such as the principle of leverage, the principle of increasing or decreasing friction, and the principle of diffuse reflection of light are also used, which will not be introduced here.
Although the bicycle is simple, but the mechanical principle contained in it is not known to everyone, all kinds of small details in life need us to observe and think, only in the learning of knowledge more attention to life, more thinking about the problem, in order to stimulate and cultivate our creativity, become our mechanical field of available talents.