Abstract: A brake pedal for a motor vehicle brake-by-wire brake system including a pedal lever pivotally supported on a body of the motor vehicle, a foot pad on the pedal lever, and a compliant member having a plurality of parallel beams defining cantilever springs. A pedal force on the foot pad effects pedal travel of the pedal lever from a release position toward a brake full apply position. The parallel beams defining cantilever springs are arrayed in series between the pedal lever and the motor vehicle body and engage is series so that the effective stiffness of the compliant member increases during pedal travel. The stiffness of each of the parallel beams and the magnitudes of a plurality of clearance spans therebetween are “tuned” to yield a pedal force which initially increases slowly relative to pedal travel and then increases exponentially relative to pedal travel thereby emulating the relationship between pedal force and pedal travel of a brake pedal in a traditional motor vehicle brake system.

Abstract: A rotary damper for use in an automotive vehicle. The rotary damper includes an outer casing having a main chamber and a pair of piston orifices, the main chamber and the piston orifices being filled with a damping fluid, a pivotable cam located in the main chamber and attached to an arm for transferring the rotary movement of the arm to the cam. The damper also includes a pair of pistons, each located in its own orifice, and connected to opposite sides of the cam. When the ami transfers the rotary movement to the cam, each piston is moved in opposite directions in its respective piston orifice to damp the rotary movement of the arm.

Abstract: A magnetorheological fluid damper is provided which permits effective control of damping while minimizing assembly size and costs by including a thin-walled insert in a flow gap formed between a flux ring and a piston body. The insert may include a thin-walled tubular insert having a generally smooth cylindrical shape for increasing the shear surface area. Alternatively, a corrugated insert may be provided having corrugations formed by edges extending axially along the insert. The corrugations may be formed in a variety of locations, sizes, shapes and spacings along the axial extent of the insert and the circumference of the insert. The corrugations advantageously effectively align the insert within the flow gap and also function to securely connect the flux ring to the piston body without the use of other devices such as plates thereby reducing the size and cost of the assembly.

Abstract: An improved magnetorheological fluid damper is provided which closely approximates ideal performance requirements by providing an increased turn-up ratio and improving the linearity of damping force response. The MR damper includes a plurality of concentric annular flow gaps formed between concentrically mounted flux rings positioned on a piston core. By utilizing multiple flow gaps, the present damper increases the overall magnetorheological damping affect thereby creating a higher damping force and an increased tun-up ratio for a given piston size. Alternatively, the present multiple flow gap design permits a given damping force requirement to be achieved with a piston having a significantly reduced length thereby permitting a longer piston stroke. Also, multiple flow gaps permit greater design optimization for controlling damping force linearity.

Abstract: A master cylinder provides separate flow paths through its secondary piston to provide greater fluid flow capacity from the reservoir to both the primary and secondary pressure chambers in response to the removal of brake fluid from the brake lines fed by the primary and secondary pressure chambers by a pump providing brake pressure for activation of one or more wheel brakes independently of the master cylinder. The secondary piston is provided with an axial fluid flow passage having check valves at each axial end permitting fluid flow only out of the axial fluid flow passage into the primary and secondary pressure chambers. A cross flow passage intersects the axial fluid flow passage between the primary and secondary check valves to communicate the axial fluid flow passage with the intermediate chamber and thus with the reservoir through the secondary compensation opening. The additional flow capacity to both pressure chambers provides improved reaction time for a traction control system at any wheel brake.

Abstract: A roll control system for installation between axially aligned wheels of a motor vehicle, the roll control system comprising a torsion bar; a first hydraulic actuator attached to one end of the torsion bar and attachable to one of the wheels; a second hydraulic actuator attached to the other end of the torsion bar and attachable to the other wheel; and an electronic control unit monitoring one or more predetermined vehicle operating conditions; wherein the first and second hydraulic actuators are substantially identical, each comprising a compression chamber containing hydraulic fluid, a rebound chamber containing hydraulic fluid, a movable piston between and fluidly isolating the compression chamber and the rebound chamber, a piston rod connected to the piston and extending through the rebound chamber, a gas chamber containing pressurised gas acting on the hydraulic fluid in the rebound chamber, and an electrically operated valve between the compression chamber and the rebound chamber and actuated by the con

Abstract: Improved control for a hydraulic system pump motor useful in automotive braking applications, particularly in motor-based ABS, includes a routine for controlling a pump motor so that it is operated in a manner that is not disturbing to automotive vehicle occupants. In particular, the control routine of the present invention controls pump motor operation after an ABS braking event so that the motor is running only when the motor noise is masked by the pulsing of the ABS solenoids or after driver braking pressure is released from the master cylinder. In this way, the amount of objectionable noise transmitted to the automotive vehicle occupants is reduced, while important ABS pump functions, such as the draining of the accumulators following an ABS braking event, are facilitated.

Abstract: This method for controlling the behaviour of an automotive vehicle during cornering consisting in measuring the rotational wheel speed of the front and rear wheels of the vehicle, establishing the wheel speed difference between the front and rear wheels and modifying the brake pressure applied to the rear wheel brakes of the vehicle according to a vehicle behaviour to be obtained, comprises the steps of elaborating a function of the absolute value of the wheel speed difference between the inner front wheel and the outer rear wheel, considering the cornering direction and using said function to determine the brake pressure variations to be applied to the rear wheel brakes.

Abstract: A snap ring closure system is particularly useful in securing a rod guide in an end of a tube of a hydraulic damper. The snap ring closure system utilizes an end cap or rod guide having a double-lobed groove and a peripheral flange about its outer end. The double-lobed groove includes an outer lobe and an inner lobe of a lesser depth than the outer lobe. A groove is formed on the tube and is positioned to design with the doubled-lobed groove when the end cap is inserted in the tube. The end cap includes a first snap ring in the outer lobe which expands outwardly into the tube groove when the cap is first inserted. The cap is secured by engagement of the first snap ring with the inner more shallow lobe. A second snap ring is placed between the flange and the end of the tube to remove any play between the end cap and tube.

Abstract: A single-operation valve assembly useful in such braking system applications, as well as others, includes a flow passage and a valve member located within the flow passage at a first position in which the valve member prevents fluid flow from an upstream side of the valve member to a downstream side of the valve member. The valve member and flow passage are configured for movement of the valve member from the first position along the flow passage to a second position along the flow passage when a pressure difference between the upstream side of the valve member and the downstream side of the valve member exceeds a threshold level. The valve member and the flow passage are also configured for free flow of fluid along the flow passage in either direction when the valve member moves to the second position. Thus, in a braking system circuit the subject valve assembly does not interfere with fluid flow in the circuit after the valve member has been blown to the second position.

Abstract: A novel and improved magnetorheological fluid damper is provided which effectively secures a flux ring to a piston core in a manner which prevents relative axial and radial movement between the flux ring and the core throughout operation. The damper includes crimp portions formed on each end of the flux ring for engaging respective end plates positioned at each end of the piston core to secure the end plates and thus the flux ring to the piston core. One of the end plates may, in turn, function to maintain a piston rod in connection with the piston core. Specifically, each end plate functions as a spring device by being elastically deformed during a crimping process causing the end plates to apply a spring force against the flux ring. One of the end plates may also apply another spring force to the piston rod. A crimping method is also provided which effectively and efficiently permits crimping in a simple manner.

Abstract: A base valve assembly fore regulating the flow of fluid through a twin tube fluid vehicle damper is provided. The base valve assembly has opposing compression and rebound surfaces. Inner and outer annular seats extend from the compression surface and define an annular channel therebetween. At least one fluid passageway connects the annular channel and the rebound surface for providing fluid communication therebetween. A connector secures a blow-off valve to the cylinder end. The blow-off valve has a hollow cylindrical portion with a flange extending transversely from an end thereof. The flange is adjacent the annular seats when the blow-off valve is in a closed position. The blow-off valve is movable from the closed position to an open position away from the compression surface. A helical spring is interposed between the connector and the blow-off valve for biasing the blow-off valve to the closed position.

Abstract: A method of operating a four quadrant motor involves (a) monitoring a motor voltage magnitude request signal which varies between zero and a maximum value and (b) monitoring a motor direction request input. In step (c), based upon the request signal and input monitored in steps (a) and (b), a voltage request reference signal is established. In a step (d) a current magnitude request signal is monitored and in a step (e) a first current request reference signal and a second current request reference signal are established based upon the signal monitored in step (d). In a step (f) a voltage across a current sense resistor of a bus connected for powering the motor is monitored and in a step (g) a sense resistor reference signal is established based upon the signal monitored in step (f). In a step (h) the first current request reference signal is compared with a feedback current signal and in a step (i) the second current request reference signal is also compared with the feedback current signal.

Abstract: A roll control system (20) for installation between axially aligned wheels of a motor vehicle, the roll control system comprising a torsion bar (22); a first hydraulic actuator (24) attached to one end (28) of the torsion bar and attachable to one of the wheels; a second hydraulic actuator (24) attached to the other end (28) of the torsion bar and attachable to the other wheel; and an electronic control unit (26) monitoring one or more predetermined vehicle operating conditions; wherein the first and second hydraulic actuators are substantially identical, each comprising a compression chamber (30) containing hydraulic fluid, a rebound chamber (32) containing hydraulic fluid, a movable piston (34) between and fluidly isolating the compression chamber and the rebound chamber, a piston rod (58) connected to the piston and extending through the rebound chamber, a gas chamber (38) containing pressurised gas acting on the hydraulic fluid in the compression chamber, a compressible spring means (80) biasing the pisto

Abstract: A valve assembly for a fluid vehicle damper having a cylinder with a valve body is provided. The valve body has an outer surface adjacent to an interior wall of the cylinder and includes first and second opposing surfaces. The valve body defines first and second fluid chambers within the damper, which are adjacent to the first and second surfaces, respectively. Inner and outer annular seats extend from the first surface and define an annular channel therebetween. At least one fluid passageway is connects the annular channel and second surface for providing fluid communication therebetween. A high speed bypass valve assembly is attached to the valve body and is movable between an open position and a closed position adjacent to the annular seats. An orifice disc is interposed between the annular seats and the high speed bypass valve assembly for providing low speed bypass of fluid from the second chamber to the first chamber when the high speed bypass valve assembly is in the closed position.

Abstract: A vehicle suspension control includes a vehicle body control responsive to body/wheel velocity at the corners of the vehicle body to derive a demand force command for dampers at each corner of the vehicle body for vehicle body control and applies each of the derived demand force commands to its respective damper only when a comparison of the direction of the demand force command with the sensed relative velocity of the damper indicates that a force corresponding to the demand force command can be effectively exerted by the damper. But the suspension control also includes a vehicle stability control responsive to an indicated vehicle lateral acceleration in a turn to determine, independently of the vehicle body control, a stability compression damping command for the suspension dampers on the side of the vehicle opposite the direction of the lateral acceleration and a stability rebound damping command for the suspension dampers on the side of the vehicle in the direction of the lateral acceleration.

Abstract: A suspension damper includes a tube and a damping piston assembly disposed within the tube and slidably mounted therein for reciprocal movement in the tube. The suspension damper also includes a piston rod extending through the tube and connected to the damping piston assembly, a rod guide assembly closing one end of the tube and a self-aligning rebound cut-off disc carried in the tube between the rod guide assembly and the damping piston assembly and cooperating with the rod guide assembly to provide a rebound cut-off effect and to compensate for misalignment between the piston rod and the damping piston assembly.

Abstract: A vacuum brake booster provides a braking speed of application enhancement by increasing the air valve opening when a vehicle operator applies braking force quickly and forcefully. This is accomplished with a two part air valve which is normally expanded axially to a normal length by an internal spring but which may be shortened to open the air valve by a greater amount when the brake pedal input force is sufficient to move the air valve axially against another spring into contact with a shoulder of the power piston. The internal spring has a much higher preload than the other spring so that the booster operates with a fully axially expanded air valve in normal, low force brake activation. Once the air valve axially engages the power piston, however, the increase in air valve opening is immediate and substantial with any further increase in braking force.

Abstract: An improved active brake control method which compensates for the effects of a banked road surface under both steady state and transient operating conditions of the vehicle. The control includes an observer for estimating the lateral velocity of the vehicle as a means of determining vehicle slip angle, and a time derivative of the estimated lateral velocity is used along with measured values of lateral acceleration, vehicle speed and yaw rate to compute the lateral acceleration component due to the banked road surface, referred to as the bank acceleration. The bank acceleration, in turn, is then used to correct the values of measured steering angle and the measured lateral acceleration used (1) to develop the desired yaw rate, slip angle and lateral acceleration, and (2) to estimate the surface coefficient of adhesion and slip angle. Partial compensation can be achieved by applying suitable gain factors to the computed bank acceleration, if desired.

Abstract: A vehicle wheel suspension has a composite, transversely oriented, leaf spring which is vertically thick and stiff in end regions extending inward from each end of the spring past the vehicle body support area but is vertically thin and compliant in a middle region between the end regions. The spring is constructed of a long, longitudinally aligned fiber and resin composite which is split at each outer end of the middle region into upper and lower horizontal layers separated by a core having a tapered inner end and extending through the end region. The inserts provide the additional vertical thickness in the end regions without widening the middle region and may be made of a different material, such as a short, randomly oriented fiber and resin composite. The spring thus flexes easily in the heave mode, in which the thin middle region of the spring flexes vertically in opposition to each end.