Damping pilot valve having vibration damper-related characteristic curves

A vibration damper comprising:

• a cylinder with an axis;
• a piston rod passing movably in an axial direction through at least one end of the cylinder;
• a piston connected inside the cylinder to the piston rod;
• a plurality of fluid chambers variable in capacity in relation to one another as a function of a movement of the piston rod relative to the cylinder;
• at least one fluid connection between at least two of the fluid chambers;
• said at least one fluid connection comprising a control valve assembly between a first section, in which a first section fluid pressure prevails, and a second section, in which a second section fluid pressure prevails, of said at least one fluid connection, the control valve assembly being constructed with at least one valve seat adjacent to which there is said first section;
• a valve control element having a first side nearer to said valve seat and a second side farther from said valve seat;
• resilient means exerting a biasing force on said valve control element such as to urge said first side of said valve control element toward a valve seat abutting position with respect to said valve seat;
• a control chamber located adjacent to the second side of the valve control element;
• a throttle section providing a fluid communication between the first section and the control chamber even if the valve control element is in the valve seat abutting position;
• control chamber outlet means extending between said control chamber and said second section;
• an externally controlled outlet cross-section dimensioning means associated with said control chamber outlet means for adjusting an outlet cross-sectional area of said control chamber outlet means to a plurality of cross-sectional area values;
• said control chamber outlet means permitting a control chamber fluid throughflow from said first section to said second section via said throttle section, said control chamber and said control chamber outlet means depending on respective cross-sectional area values of said outlet cross-sectional area of said control chamber outlet means;
• said first side of said valve control element being subjected to a first section side fluid force provided by said first section fluid pressure prevailing in said first section;
• said second side of said valve control element being subjected to a control chamber side fluid force provided by a control chamber fluid pressure prevailing in said control chamber;
• said valve control element being liftable from said valve seat in response to a lifting relationship between the magnitudes of said biasing force, said first section side fluid force and said control chamber side fluid force;
• lifting start influencing means being provided for influencing the start of lifting off said valve control element from said valve seat such that at least for cross-sectional area values above a predetermined cross-sectional area value of the control chamber outlet means the valve control element starts to lift from said valve seat in response to an increasing pressure difference between said first section fluid pressure and said second section fluid pressure at a substantially constant throughflow rate of said control chamber fluid throughflow irrespective of the respective cross-sectional area value of said outlet cross-sectional area of said control chamber outlet means.

A vibration damper comprising:

• a cylinder with an axis;
• a piston rod passing movably in an axial direction through at least one end of the cylinder;
• a piston connected inside the cylinder to the piston rod;
• a plurality of fluid chambers variable in capacity in relation to one another as a function of a movement of the piston rod relative to the cylinder;
• at least one fluid connection between at least two of the fluid chambers;
• said at least one fluid connection comprising a control valve assembly between a first section, in which a first section fluid pressure prevails, and a second section, in which a second section fluid pressure prevails, of said at least one fluid connection, the control valve assembly being constructed with at least one valve seat adjacent to which there is said first section;
• a valve control element having a first side nearer to said valve seat and a second side farther from said valve seat;
• resilient means exerting a biasing force on said valve control element such as to urge said first side of said valve control element toward a valve seat abutting position with respect to said valve seat;
• a control chamber located adjacent to the second side of the valve control element;
• a throttle section providing a fluid communication between the first section and the control chamber even if the valve control element is in the valve seat abutting position;
• control chamber outlet means extending between said control chamber and said second section;
• an externally controlled outlet cross-section dimensioning means associated with said control chamber outlet means for adjusting an outlet cross-sectional area of said control chamber outlet means to a plurality of cross-sectional area values;
• said control chamber outlet means permitting a control chamber fluid throughflow from said first section to said second section via said throttle section, said control chamber and said control chamber outlet means depending on respective cross-sectional area values of said outlet cross-sectional area of said control chamber outlet means;
• said first side of said valve control element being subjected to a first section side fluid force provided by a first section fluid pressure prevailing in said first section;
• said second side of said valve control element being subjected to a control chamber side fluid force provided by a control chamber fluid pressure prevailing in said control chamber;
• said valve control element being liftable from said valve seat in response to a lifting relationship between the magnitudes of said biasing force, said first section side fluid force and said control chamber side fluid force;
• lifting start influencing means being provided for influencing the start of lifting off said valve control element from said valve seat such that for decreasing cross-sectional area values the valve control element starts to lift from said valve seat in response to an increasing pressure difference between said first section fluid pressure and said second section fluid pressure at decreasing throughflow rates of said control chamber fluid throughflow.

A vibration damper comprising:

• a cylinder with an axis;
• a piston rod passing movably in an axial direction through at least one end of the cylinder;
• a piston connected inside the cylinder to the piston rod;
• a plurality of fluid chambers variable in capacity in relation to one another as a function of a movement of the piston rod relative to the cylinder;
• at least one fluid connection between at least two of the fluid chambers;
• said at least one fluid connection comprising a control valve assembly between a first section, in which a first section fluid pressure prevails, and a second section, in which a second section fluid pressure prevails, of said at least one fluid connection, the control valve assembly being constructed with at least one valve seat adjacent to which there is said first section;
• a valve control element having a first side nearer to said valve seat and a second side farther from said valve seat;
• resilient means exerting a biasing force on said valve control element such as to urge said first side of said valve control element toward a valve seat abutting position with respect to said valve seat;
• a control chamber located adjacent to the second side of the valve control element;
• a throttle section providing a fluid communication between the first section and the control chamber even if the valve control element is in the valve seat abutting position;
• control chamber outlet means extending between said control chamber and said second section;
• an externally controlled outlet cross-section dimensioning means associated with said control chamber outlet means for adjusting an outlet cross-sectional area of said control chamber outlet means to a plurality of cross-sectional area values;
• said control chamber outlet means permitting a control chamber fluid throughflow from said first section to said second section via said throttle section, said control chamber and said control chamber outlet means depending on respective cross-sectional area values of said outlet cross-sectional area of said control chamber outlet means;
• said first side of said valve control element being subjected to a first section side fluid force provided by a first section fluid pressure prevailing in said first section;
• said second side of said valve control element being subjected to a control chamber side fluid force provided by a control chamber fluid pressure prevailing in said control chamber;
• said valve control element being liftable from said valve seat in response to a lifting relationship between the magnitudes of said biasing force, said first section side fluid force and said control chamber side fluid force;
• one of first and second lifting start influencing means being provided for influencing the start of lifting off said valve control element from said valve seat,
• said first lifting start influencing means being such that at least for cross-sectional area values above a predetermined cross-sectional area value of the control chamber outlet means the valve control element starts to lift from said valve seat in response to an increasing pressure difference between said first section fluid pressure and said second section fluid pressure at a substantially constant throughflow rate of said control chamber fluid throughflow irrespective of the respective cross-sectional area value of said outlet cross-sectional area of said control chamber outlet means, and
• said second lifting start influencing means being such that for decreasing cross-sectional area values the valve control element starts to lift from said valve seat in response to an increasing pressure difference between said first section fluid pressure and said second section fluid pressure at decreasing throughflow rates of said control chamber fluid throughflow.

A vibration damper comprising:

• a cylinder with an axis;
• a piston rod passing movably in an axial direction through at least one end of the cylinder;
• a piston connected inside the cylinder to the piston rod;
• a plurality of fluid chambers variable in capacity in relation to one another as a function of a movement of the piston rod relative to the cylinder;
• at least one fluid connection between at least two of the fluid chambers;
• said at least one fluid connection comprising a control valve assembly between a first section, in which a first section fluid pressure prevails, and a second section, in which a second section fluid pressure prevails, of said at least one fluid connection, the control valve assembly being constructed with at least one valve seat adjacent to which there is said first section;
• a valve control element having a first side nearer to said valve seat and a second side farther from said valve seat;
• resilient means exerting a biasing force on said valve control element such as to urge said first side of said valve control element toward a valve seat abutting position with respect to said valve seat;
• a control chamber located adjacent to the second side of the valve control element;
• a throttle section providing a fluid communication between the first section and the control chamber even if the valve control element is in the valve seat abutting position;
• control chamber outlet means extending between said control chamber and said second section;
• an externally controlled outlet cross-section dimensioning means associated with said control chamber outlet means for adjusting an outlet cross-sectional area of said control chamber outlet means to a plurality of cross-sectional area values;
• said control chamber outlet means permitting a control chamber fluid throughflow from said first section to said second section via said throttle section, said control chamber and said control chamber outlet means depending on respective cross-sectional area values;
• said first side of said valve control element being subjected to a first section side fluid force provided by said first section fluid pressure prevailing in said first section;
• said second side of said valve control element being subjected to a control chamber side fluid force provided by a control chamber fluid pressure prevailing in said control chamber;
• said valve control element being liftable from said valve seat in response to a lifting relationship between the magnitudes of said biasing force, said first section side fluid force and said control chamber side fluid force;
• wherein, when the outlet cross-sectional dimensioning means is set for a maximum cross-sectional area value of the outlet cross-sectional area of the control chamber outlet means, the valve control element starts to lift from the valve seat when said control chamber fluid throughflow amounts to at least 0.2 times a total throughflow through the control valve assembly that results in response to a damper velocity of 1 m/sec.