Gm Global Technolgoy Operations, Inc.

Kenneth R Meloche

James G McLeish

Herbert A Libkie

Harry C Buchanan, Jr

Bernard J Finn

Ming-Chih Yew

Charles B Steger

Gene A Maguran

Coburn C Bland, Jr

Ronald R Terry

Douglas R Bach

An electrically controlled shock absorber includes a pumping unit which provides unidirectional fluid flow through an electrically controlled valve apparatus. The electrically controlled valve apparatus is contained in a housing external to the pumping unit in a housing defining an inlet chamber and a control chamber. A horizontally reciprocable inlet valve member controls fluid flow from the pumping unit into the inlet chamber, from which it can flow unimpeded to a reservoir chamber. The inlet valve member has an inlet orifice therethrough to allow fluid flow into the control chamber, create a pressure drop across the inlet valve member effective to cancel a constant closing bias thereon, and damp inlet valve member movement. An electromagnetically controlled pilot valve in an outlet from the control chamber to the reservoir chamber produces a control pressure in the control chamber as a function of an input electric current. The inlet valve opens as necessary to ensure that the pressure of the fluid pumped out of the pumping unit substantially equals the control pressure. The damping force is thus a function of input current independent of fluid flow rate. The pilot valve is designed for stable operation.

Electrically controlled shock absorber

Active suspension for vehicles with a dual acting hydraulic actuator providing foreshortened overall length for a given amount of stroke. A conventional suspension unit when designed to give appropriate wheel travel protruded through the hood. The cylinder tube of the actuator of this invention makes use of concentric tubes proportioned to provide the same pressure-force relationship in both directions and to be no larger than the conventional unit. This actuator also incorporates a trapped air volume that is separate from the oil volumes. This air volume can be appropriately sized so that an air-spring is created by the moving piston. The air spring is of approximately the correct load an rate for the vehicle. This removes the requirement for carrying static vehicle load from the hydraulic portion of the device, which reduces power consumption. This eliminates the requirement for a coil spring around the actuator to carry these static loads and provides a 'limp-home' capability in the event that the hydraulic system becomes damaged.

Dual acting hydraulic actuator for active suspension system

An adaptive ride control for a wheeled vehicle having sprung and unsprung masses connected by a variable damper periodically senses, during a predetermined time period, the vertical separation between the sprung and unsprung masses and generates first and second numbers from the number of road-caused oscillations of said vertical separation and the maximum range of said vertical separation, respectively, during the predetermined time period. The control includes lookup memory apparatus effective to store damping control numbers as a function of predetermined values of said first and second numbers and uses the first and second numbers to periodically obtain damping control numbers therefrom in order to adjust the variable damper in response to sensed road conditions.

Adaptive ride control for motor vehicle

A level control system for a motor vehicle with an unsprung mass including a wheel, a sprung mass, and a shock absorber connecting the sprung and unsprung masses comprises fluid power apparatus activatable to level the sprung mass with respect to the unsprung mass, a sensor effective to generate a signal indicating the level of the sprung mass relative to the unsprung mass and apparatus responsive to the sensor to compute the difference between the total times, within a predetermined time period, spent by the level above and below a predetermined trim band and apparatus effective to compare the difference of the times with a reference comprising a predetermined percentage of the predetermined time period and activate the fluid power apparatus if the difference exceeds the reference in magnitude, whereby the system can maintain a narrow trim band while the vehicle is not moving while avoiding unnecessary corrections and cycling due to excursions above and below the trim band during vehicle movement over rough surfaces.

Automatic vehicle level control

A level control system for a wheeled motor vehicle with sprung and unsprung masses, an accessory the activation of which indicates the probability of an associated vehicle load change, fluid power apparatus activatable to level the sprung mass relative to the unsprung mass and sensor apparatus effective to periodically indicate a trim or out-of-trim level condition according to predetermined criteria further comprises apparatus defining a service mode with a time period shorter than a predetermined activation time of the fluid power apparatus which avoids overshoot in level adjustment, a cruise mode with a time period longer than the out-of-trim duration of a predetermined long highway feature and a decision mode with a time period of duration intermediate the service and cruise time period durations and longer than the period of sprung mass oscillation during vehicle movement. It further comprises logic control apparatus effective to select from the service, cruise and decision time modes for the determination of trim level condition based on the previous mode, the trim level determination in the previous period and detection of an actuation of the accessory, with the decision mode being selected upon the initiation of system operation and as an intermediate step between service and cruise modes.

An automotive vehicle having a turbocharged internal combustion engine and a heat initiated exhaust treatment device, such as a catalytic converter, in the exhaust system is provided with a multiple function turbine bypass valve with controls that provide bypass of the exhaust gases directly to the treatment device during warm-up and also provide a boost controlling wastegate function that limits the turbocharger boost pressure during normal operation. Full throttle bypass override to provide turbocharger boost during warm-up as well as other control and operating functions are also disclosed.

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Warren, MI, United States of America

Kenneth R Meloche