Automatic adjustment resonance device

The invention discloses an automatic adjustment resonance device, which is applied to an air inlet system of an engine. The device comprises a rubber buffer block, a variable rigidity spring, a first plate, a second plate and a third plate. The variable rigidity spring is fixed on the rubber buffer block and the free end thereof is rightly contacted with the third plate; the first plate, the second plate and the third plate and the bottom surface of a pressure-stabilizing cavity form a four link structure; the basic shape of the four link structure is a rectangle with the height lower than the lower edge of an air inlet manifold. The automatic adjustment resonance device has compact structure, eliminates the original resonance cavity part, is beneficial to total distribution of an engine bin, has automatic adjustment capability, changes reflection characteristics to pressure wave of an air inlet manifold, utilizes the pulsation effect to increase the air inlet charging coefficient and realizes the improvement