Variable damping force shock absorber
AssigneeHUSCO International, Inc.
InventorRaud A. Wilke
Life of this patent
Estimating the term…
Abstract
A semi-active vehicle suspension system employing a shock absorber whose damping characteristics are variable under the control of a signal representing one or more conditions of the vehicle. The system employs a coaxially arranged valve pair to provide one or two fluid flow paths between a chamber of the shock absorber and a reservoir. Two of such coaxial valve pairs may be used in tandem to control both chambers of the shock absorber in an inverse relationship. Both of the tandem pairs may be controlled by a single spool which is controlled by a single control signal.
Claims22
A shock absorber for variably damping the transmission of forces between a body of a vehicle and a suspension member supporting a road wheel, the vehicle being of the type which has an apparatus for sensing one or more operating conditions and transmitting one or more control signals which are indicative of the operating conditions, the shock absorber comprising:
- (a) a housing adapted for connection to one of the vehicle body and the suspension member and defining an internal space, and a piston adapted for connection to the other of the vehicle body and the suspension member and disposed within the internal space for dividing the internal space into a first working chamber and a second working chamber and for moving relative to the housing, the working chambers containing a working fluid;
- (b) an assembly of a threshold valve and a main valve adapted to supplementarily control the flow of fluid from the first working chamber to a receiving chamber, the threshold valve and the main valve having front sides subject to the pressure in the first working chamber and opposite back sides;
- (c) a pilot fluid path from the front sides of the threshold and main valves to the back sides;
- (d) a pilot circuit providing fluid communication from the pilot fluid path through a variable orifice to the receiving chamber;
- (e) an orifice modifier adapted to vary the size of the variable orifice in the pilot circuit;
- (f) a remotely controlled actuator adapted to operate the orifice modifier, the actuator being controlled by the one or more control signals;
- (g) means for providing for a complete circuit of the fluid among the working chambers and the receiving chamber;
- (h) whereby varying the cross sectional area of the variable orifice varies the pressure on the back sides of the threshold valve and the main valve and thereby varies the amount of pressure in the first working chamber needed to open the threshold valve and the main valve.
A shock absorber for variably damping the transmission of forces between a body of a vehicle and a suspension member supporting a road wheel, the vehicle being of the type which has an apparatus for sensing one or more operating conditions and transmitting one or more control signals which are indicative of the operating conditions, the shock absorber comprising:
- (a) a housing adapted for connection to one of the vehicle body and the suspension member and defining an internal space, and a piston adapted for connection to the other of the vehicle body and the suspension member and disposed within the internal space for dividing the internal space into a first working chamber and a second working chamber and for moving relative to the housing, the working chambers containing a working fluid;
- (b) a first valve assembly adapted to control the flow of fluid from the first working chamber to a first receiving chamber, the first valve assembly having a front side subject to the pressure in the first working chamber and an opposite back side;
- (c) a second valve assembly adapted to control the flow of fluid from the second working chamber to a second receiving chamber, the second valve assembly having a front side subject to the pressure in the first working chamber and an opposite back side;
- (d) a first pilot fluid path from the front side of the first valve assembly to the back side;
- (e) a second pilot fluid path from the front side of the second valve assembly to the back side;
- (f) a pilot circuit providing fluid communication from the first pilot fluid path through a first variable orifice to the first receiving chamber and from the second pilot fluid path through a second variable orifice to the second receiving chamber;
- (g) an orifice modifier apparatus adapted respectively to vary the size of the first variable orifice and the size of the second variable orifice, the orifice modifier apparatus being inversely ganged so that any orifice modifying operation both enlarges one of the first and second variable orifices and reduces the other of the first and second variable orifices;
- (h) a remotely controlled actuator adapted to operate the orifice modifier apparatus, the actuator being controlled by the one or more control signals;
- and
- (i) means for providing for a complete circuit of the fluid among the working chambers and the receiving chambers;
- (j) whereby varying the sizes of the first and second variable orifices varies the pressure on the back sides of the first and second valve assemblies and thereby varies the amount of pressure in the first and second working chambers respectively needed to open the first and second valve assemblies.
Dependencies are inferred from the claim text.