The madeborg hemispheric experiment is well known. In 1654, Otto von Grick, then mayor of madeborg, carried out a scientific experiment in Regensburg (now Regensburg, Germany) of the Holy Roman Empire to prove the existence of atmospheric pressure. With the cooperation of him and his assistant, he made two hemispheres with a diameter of about 37 cm. Grick and his assistant pumped a vacuum in the hemisphere in public. Four grooms and eight big horses pulled the hemisphere in the opposite direction. With some efforts, the hemispheric striated wire did not move. Through this “large-scale experiment”, people finally believe that the atmosphere has pressure and is amazing.
Under normal conditions, the vacuum booster of most models maintains a vacuum degree of 600mbar-800mbar. Vacuum is generated by the venturi around the intake pipe of the engine, or by the electronic vacuum pump (EVP).
As shown in the figure, the balanced vacuum booster is mainly composed of the just mentioned front cavity and rear cavity, and the middle membrane flap (black) separates the front and rear cavities.
The figure shows the booster state during braking. It can be seen that part of the atmosphere enters the rear chamber due to the propulsion of the entry pole (note that it is part, which is determined by the driver’s pedal force, i.e. depth).
As shown in the figure, the balanced vacuum booster is mainly composed of the just mentioned front cavity and rear cavity, and the middle membrane flap (black) separates the front and rear cavities.