Damper with digital valve

摘要

A shock absorber has a compression valve assembly that provides a high damping load during a compression stroke and an extension valve assembly that provides a high damping load during an extension stroke. One or more digital valve assemblies is positioned to work in parallel with the compression valve assembly and the extension valve assembly to provide a lower damping load. The lowering of the damping load is based upon the cross sectional area of flow passages provided by the one or more digital valve assemblies.

主权项

1. A shock absorber comprising:
a pressure tube forming a working chamber; a piston assembly slidably disposed within said pressure tube, said piston assembly dividing said working chamber into an upper working chamber and a lower working chamber, said piston assembly including a piston body defining a first fluid passage extending through said piston body and a first valve assembly controlling fluid flow through said first fluid passage; a piston rod assembly attached to said piston assembly; a second fluid passage separate from said first fluid passage, said second fluid passage extending from one of said upper and lower working chambers to a fluid chamber; and a digital valve assembly controlling fluid flow through said second fluid passage; wherein fluid flow through said first valve assembly generates a high damping load for said shock absorber; fluid flow through said first and digital valve assemblies generates a low damping load, lower than said high damping load, for said shock absorber; said second fluid passage is defined by said piston rod assembly; said digital valve assembly is disposed within said piston rod assembly; said second fluid passage extends between said upper and lower working chambers; the other of said upper and lower working chambers defines said fluid chamber; said digital valve assembly includes a first member, a second member disposed within said first member to move in an axial direction within said first member and a third member configured to move said second member in the axial direction; said digital valve assembly includes a single inlet, a first outlet and a second outlet separate from the first outlet; and fluid flow from said single inlet to said first outlet is in a first direction parallel to said axial direction and fluid flow from said single inlet to said second outlet is in a second direction parallel to said axial direction, said second direction being opposite to said first direction.