Compression spring for suspending motor vehicle, has foam block constituted of superimposed layers and compressed between upper and lower shells, where non compacted density of foam is lower than specific values

摘要

The spring (1) has a foam block (2) including a cellular structure with elastomer e.g. diene elastomer with butyl rubber, based closed cell, where the block is constituted of superimposed layers. The foam block is compressed between upper and lower shells (3, 4), and is in a form of cylinder of circular section. Non compacted density of the foam is lower than 0.2. A cylindrical central cavity (6) houses an element, and guides and dampens movement of the spring. The cavity is sealed to contain quantity of pressurized fluid whose pressure is controlled to modulate the stiffness of the spring.