US 5,937,975 AGranted

Vibration damper for a motor vehicle and a vibration damper having a damping valve with adjustable damping force for a motor vehicle

AssigneeFichtel & Sachs AG

InventorAndreas Forster

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Abstract

A vibration damper has a cylinder filled with damping medium. In the cylinder, a piston rod with a piston is realized so that the piston can move axially. The piston divides the cylinder into two working chambers. The vibration damper also has a damping valve. The damping force of the damping valve can be changed by a magnetic force generated by a magnetic coil inside a magnetic return body on an armature against a spring force of at least one spring. At least two regulating or adjustment parameters are provided to set at least two characteristics which differ from one another in terms of different flows to the magnetic coil. The characteristics can be set by a change of the effective spring characteristic with reference to a damping valve stroke position of the damping valve and also by the ability to regulate the magnetic conductivity of the magnetic return body by an actuator. The actuator can have a magnetic constriction, to which constriction a magnetic conductor body can be connected in parallel.

Claims20

Dependent claims

A vibration damper having an adjustable damping force characteristic for a motor vehicle, said vibration damper comprising:

a cylinder;
said cylinder being configured to contain a damping medium;
said cylinder comprising a first end and a second end disposed opposite to said first end of said cylinder;
said first end of said cylinder being configured to operatively connect to a first part of a motor vehicle;
a piston rod;
said piston rod sealingly projecting into said second end of said cylinder;
said piston rod comprising a first end and a second end;
said second end of said piston rod being disposed opposite to said first end of said piston rod;
said first end of said piston rod being configured to operatively connect to a second part of a motor vehicle;
a piston;
said piston being disposed on said second end of said piston rod;
said piston being configured and disposed to slide within said cylinder;
said piston being configured and disposed to divide said cylinder into a first chamber and a second chamber;
a damping valve;
said damping valve being configured and disposed to control flow of damping medium from at least one of said first chamber and said second chamber to adjust the damping force characteristic of said vibration damper;
said damping valve having a longitudinal axis;
and
said damping valve comprising:
a magnetic coil;
said magnetic coil being configured to generate magnetic flux upon application of electrical current to said magnetic coil;
a magnetic path to permit guidance of magnetic flux generated by said magnetic coil in said damping valve;
said magnetic path comprising an armature structure;
a portion of said armature structure being configured and disposed to control flow of damping medium through said damping valve to adjust the damping force characteristic of said vibration damper;
said armature structure being configured and disposed to be displaced in a first axial direction by magnetic flux generated by said magnetic coil to control the flow of damping medium through said damping valve;
a spring arrangement;
said spring arrangement being disposed to bias said armature structure in a direction opposite to the first axial direction to control the flow of damping medium through said damping valve;
said spring arrangement being configured to vary the bias applied to said armature structure by said spring arrangement;
said magnetic path comprising an arrangement to adjust the guidance of magnetic flux through said magnetic path to said armature structure to adjust a force in said armature structure produced by said magnetic flux;
said arrangement to adjust the guidance of magnetic flux comprising a first member and a second member;
said first member being configured to restrict guidance of magnetic flux through said magnetic path;
said second member being configured to permit guidance of magnetic flux around said first member;
and
said second member being connected substantially parallel to said first member.

30 more elements

A vibration damper having an adjustable damping force characteristic for a motor vehicle, said vibration damper comprising:

a cylinder;
said cylinder being configured to contain a damping medium;
said cylinder comprising a first end and a second end disposed opposite to said first end of said cylinder;
said first end of said cylinder being configured to operatively connect to a first part of a motor vehicle;
a piston rod;
said piston rod sealingly projecting into said second end of said cylinder;
said piston rod comprising a first end and a second end;
said second end of said piston rod being disposed opposite to said first end of said piston rod;
said first end of said piston rod being configured to operatively connect to a second part of a motor vehicle;
a piston;
said piston being disposed on said second end of said piston rod;
said piston being configured and disposed to slide within said cylinder;
said piston being configured and disposed to divide said cylinder into a first chamber and a second chamber;
a damping valve;
said damping valve being configured and disposed to control flow of damping medium from at least one of said first chamber and said second chamber to adjust the damping force characteristic of said vibration damper;
said damping valve having a longitudinal axis;
and
said damping valve comprising:
a magnetic coil;
said magnetic coil being configured to generate magnetic flux upon application of electrical current to said magnetic coil;
a magnetic path to permit guidance of magnetic flux generated by said magnetic coil in said damping valve;
said magnetic path comprising an armature structure;
a portion of said armature structure being configured and disposed to control flow of damping medium through said damping valve to adjust the damping force characteristic of said vibration damper;
said armature structure being configured and disposed to be displaced in a first axial direction by magnetic flux generated by said magnetic coil to control the flow of damping medium through said damping valve;
a spring arrangement;
said spring arrangement being disposed to bias said armature structure in a direction opposite to the first axial direction to control the flow of damping medium through said damping valve;
said spring arrangement being configured to vary the bias applied to said armature structure by said spring arrangement;
and
said magnetic path comprising an arrangement to adjust the guidance of magnetic flux through said magnetic path to said armature structure to adjust a force in said armature structure produced by said magnetic flux.

26 more elements

Dependencies are inferred from the claim text.