Automotive suspension system with variable suspension characteristics and variable damping force shock absorber therefor

An automotive suspension system comprising:

• a shock absorber disposed between a vehicle body and a suspension member rotatably supporting a road wheel, said shock absorber including a cylinder tube connected to one of said vehicle body and said suspension member and defining an internal space, a piston disposed within said internal space for dividing said internal space into first and second chambers and connected to the other of said vehicle body and said suspension member for relative movement with respect to said cylinder tube, said first and second chambers being filled with a working fluid;
• a fluid communication means for establishing fluid communication between said first and second chambers with a limited fluid flow rate for generating a damping force against relative motion between said piston and said cylinder tube;
• a valve means associated with said fluid communication means for controlling flow restriction of said fluid communication means, said valve means being variable of flow restriction characteristics for varying damping characteristics of said shock absorber;
• a sensor means for monitoring fluid pressure in said first chamber for producing a piston stroke indicative signal indicative of magnitude of piston stroke;
• an actuating means, associated with said valve means and responsive to a control signal, for controlling said valve means for adjusting flow restriction characteristics according said said control signal;
• and
• a controlling means, receiving said piston stroke indicative signal, for deriving a piston motion representative data on the basis of said piston stroke indicative signal, comparing said piston motion representative data with a predetermined deadband criteria which are set with respect to a neutral value and defining a predetermined deadband, and detecting said piston motion representative data out of said deadband and reaching a peak value for producing said control signal for harder damping characteristics and detecting said piston motion representative data entering into said deadband for producing said control signal for softer damping characteristics.

An automotive suspension system comprising:

• a shock absorber disposed between a vehicle body and a suspension member rotatably supporting a road wheel, said shock absorber including a cylinder tube connected to one of said vehicle body and said suspension member and defining an internal space, a piston disposed within said internal space for dividing said internal space into first and second chambers and connected to the other of said vehicle body and said suspension member for relative movement with respect to said cylinder tube, said first and second chambers being filled with a working fluid;
• a fluid communication means for establishing fluid communication between said first and second chambers with a limited fluid flow rate for generating a damping force against relative motion between said piston and said cylinder tube;
• a valve means associated with said fluid communication means for controlling flow restriction of said fluid communication means, said valve means being variable of flow restriction characteristics for varying damping characteristics of said shock absorber;
• a sensor means for monitoring fluid pressure in said first chamber for producing a piston stroke indicative signal indicative of magnitude of piston stroke;
• an actuating means, associated with said valve means and responsive to a control signal, for controlling said valve means for adjusting flow restriction characteristics according said said control signal;
• and
• a controlling means, receiving said piston stroke indicative signal, for deriving a piston motion representative data on the basis of said piston stroke indicative signal, comparing said piston motion representative data with a predetermined deadband criteria which are set with respect to a neutral value and defining a predetermined deadband for producing said control signal for harder damping characteristics, and detecting said piston motion representative data varying across one of said deadband criteria to be out of said deadband for producing said control signal for softer damping characteristics, detecting said piston motion representative data reaching a peak value for producing said control signal for harder damping characteristics.

An automotive suspension system comprising:

• a shock absorber disposed between a vehicle body and a suspension member rotatably supporting a road wheel, said shock absorber including a cylinder tube connected to one of said vehicle body and said suspension member and defining an internal space, a piston disposed within said internal space for dividing said internal space into first and second chambers and connected to the other of said vehicle body and said suspension member for relative movement with respect to said cylinder tube, said first and second chambers being filled with a working fluid;
• a fluid communication means for establishing fluid communication between said first and second chambers with a limited fluid flow rate for generating a damping force against relative motion between said piston and said cylinder tube;
• a valve means associated with said fluid communication means for controlling flow restriction of said fluid communication means, said valve means being variable of flow restriction characteristics for varying damping characteristics of said shock absorber;
• a sensor means for monitoring fluid pressure in said first chamber for producing a fluid pressure indicative signal indicative of magnitude of fluid pressure;
• an actuating means, associated with said valve means and responsive to a control signal, for controlling said valve means for adjusting flow restriction characteristics according said said control signal;
• and
• a controlling means, receiving said fluid pressure indicative signal, for deriving a pressure variation representative data on the basis of said fluid pressure indicative signal, comparing said pressure variation representative data with a predetermined deadband criteria which are set with respect to a neutral value and defining a predetermined deadband, and detecting said pressure variation representative data out of said deadband and reaching a peak value for producing said control signal for harder damping characteristics and detecting said pressure variation representative data varying across said neutral value for producing said control signal for softer damping characteristics.

An automotive suspension system comprising:

• a shock absorber disposed between a vehicle body and a suspension member rotatably supporting a road wheel, said shock absorber including a cylinder tube connected to one of said vehicle body and said suspension member and defining an internal space, a piston disposed within said internal space for dividing said internal space into first and second chambers and connected to the other of said vehicle body and said suspension member for relative movement with respect to said cylinder tube, said first and second chambers being filled with a working fluid;
• a fluid communication means for establishing fluid communication between said first and second chambers with a limited fluid flow rate for generating a damping force against relative motion between said piston and said cylinder tube;
• a valve means associated with said fluid communication means for controlling flow restriction of said fluid communication means, said valve means being variable of flow restriction characteristics for varying damping characteristics of said shock absorber;
• a sensor means for monitoring fluid pressure in said first chamber for producing a fluid pressure indicative signal indicative of magnitude of fluid pressure;
• an actuating means, associated with said valve means and responsive to a control signal, for controlling said valve means for adjusting flow restriction characteristics according said said control signal;
• and
• a controlling means, receiving said fluid pressure indicative signal, for deriving a pressure variation representative data on the basis of said fluid pressure indicative signal, comparing said pressure variation representative data with a predetermined deadband criteria which are set with respect to a neutral value and defining a predetermined deadband, and detecting said pressure variation representative data out of said deadband and reaching a peak value for producing said control signal for harder damping characteristics and detecting said pressure variation representative data entering into said deadband for producing said control signal for softer damping characteristics.

An automotive suspension system comprising:

• a shock absorber disposed between a vehicle body and a suspension member rotatably supporting a road wheel, said shock absorber including a cylinder tube connected to one of said vehicle body and said suspension member and defining an internal space, a piston disposed within said internal space for dividing said internal space into first and second chambers and connected to the other of said vehicle body and said suspension member for relative movement with respect to said cylinder tube, said first and second chambers being filled with a working fluid;
• a fluid communication means for establishing fluid communication between said first and second chambers with a limited fluid flow rate for generating a damping force against relative motion between said piston and said cylinder tube;
• a valve means associated with said fluid communication means for controlling flow restriction of said fluid communication means, said valve means being variable of flow restriction characteristics for varying damping characteristics of said shock absorber;
• a sensor means for monitoring fluid pressure in said first chamber for producing a fluid pressure indicative signal indicative of magnitude of fluid pressure;
• an actuating means, associated with said valve means and responsive to a control signal, for controlling said valve means for adjusting flow restriction characteristics according said said control signal;
• and
• a controlling means, receiving said fluid pressure indicative signal, for deriving a pressure variation representative data on the basis of said fluid pressure indicative signal, comparing said pressure variation representative data with a predetermined deadband criteria which are set with respect to a neutral value and defining a predetermined deadband for producing said control signal for harder damping characteristics, and detecting said pressure variation representative data varying across one of said deadband criteria to be out of said deadband for producing said control signal for softer damping characteristics, detecting said pressure variation representative data reaching a peak value for producing said control signal for harder damping characteristics.