Abstract: A method of validating a leak detection test for a fuel tank in a vehicle includes the steps of determining a vacuum decay rate of a fuel vapor in the fuel tank and dividing the vacuum decay rate into a set of adjacent segments distributed over a series of consecutive time intervals. The method also includes the steps of determining a slope of the segments, determining if a difference between two consecutive slopes of the segments meets a predetermined criteria, and validating the leak detection test if the difference meets the predetermined criteria.

Abstract: A method of improving the operating characteristics of an internal combustion engine equipped with electronic throttle control employs variable cam timing to vary the phasing of the intake valves and/or exhaust valves so as to achieve lower feed gas emissions and improved fuel economy while delivering as closely as possible the desired torque. The method can be implemented using a fuel-lead strategy or an air-lead strategy. Whenever a change is requested in the amount of torque, the method responds by adjusting the amount of fuel flow, the spark timing, the position of the throttle and/or the positions of the intake valves and/or the exhaust valves so as to deliver the desired torque. The method adjusts those operating parameters in a way that improves the ability of the engine to deliver the desired torque, produce less feed gas emissions, idle more stably, and consume less fuel.

Abstract: An improved method of diagnosing evaporative emission system leaks at engine idle, wherein the system is closed and drawn down to a sub-atmospheric pressure early in a driving cycle prior to the achievement of an idle condition appropriate for leak testing. When the test enabling conditions other than engine idle are met, the system vent is closed, and the purge valve is modulated to regulate the fuel tank pressure at a sub-atmospheric value substantially equivalent to the leak test pressure to be used at engine idle. When engine idle is achieved, the purge valve is closed, and the leak test is conducted with little or no delay. The time required to conduct the leak test is improved because the system pressure is at or near the test pressure when the engine idle condition is achieved, and at the same time, the reliability of the leak test data is improved because vapor generation equilibrium in the fuel tank is more nearly achieved when the leak test is initiated.

Abstract: Disclosed herein is an apparatus and process for punching and placing inserts of electrolyte and other material into a substrate layer for a gas sensor. The insert can be the solid electrolyte, porous electrolyte or protective layer of a gas sensor. The substrate material is typically alumina. The apparatus punches a hole in the alumina substrate, and then, in one step, punches an insert of a second material, such as a solid electrolyte, into the previously formed hole, thereby forming a composite layer/insert.

Abstract: An improved control methodology for an engine control valve, in which the valve is positioned in response to a commanded flow rate of the controlled medium. The method involves a valve characterization procedure in which the actual flow rate is measured for various combinations of valve position and pressure ratio across the valve, subject to a standard set of upstream pressure and temperature values. This results in a table of valve position in terms of pressure ratio and standard flow rate—that is, flow rate under the standard upstream pressure and temperature values. In operation, a controller addresses the table to obtain the desired valve position as a function of a determined pressure ratio across the valve, and a desired standard flow rate determined based on the commanded flow rate and the pressure and temperature of the controlled medium upstream of the valve, relative to the standard pressure and temperature values.

Abstract: A fuel tank cover assembly for a fuel tank of a vehicle includes a cover adapted to close an opening in the fuel tank having a fuel reservoir disposed therein and a universal joint coupling disposed between the cover and the fuel reservoir to allow the cover to be skewed from a bottom of the fuel tank.

Abstract: Purging of a fuel vapor storage canister of an internal combustion engine is optimized through the provision of fuel vapor storage apparatus. A real time measurement of the fuel vapor content of the canister is enabled by providing the canister with a fuel vapor sensor located in at least one of the purge line and the fresh air port of the canister. The fuel vapor sensor is most preferably an adsorption sensitive resistor which operates on the principle of adsorption according to Vander Walls “a” constant, and the electrical resistance of the fuel vapor sensor preferably varies with respect to the fuel vapor concentration present.

Abstract: An ion sensor glow plug assembly includes a shell for attachment to a cylinder head of a compression ignition engine and having a passageway extending axially therethrough. The ion sensor glow plug assembly also includes a center terminal disposed at least partially in the passageway of the shell and connected to a source of power to create a heating circuit. The ion sensor glow plug assembly includes a glow sheath disposed at least partially is the passageway of the shell and about the center terminal to create an ion sensing circuit. The ion sensor glow plug assembly further includes an insulator disposed at least partially in the passageway of the shell and about a portion of the glow sheath and extending axially therefrom to clean off soot on the glow sheath. The ion sensor glow plug assembly includes a coating disposed about a portion of the glow sheath between the glow sheath and the shell to isolate the shell from the glow sheath.

Abstract: A mass flow sensor for measuring flow of a medium comprises a body, a membrane fixed on the body, a pair of thin film heating elements arranged on the membrane, and a sensing element arranged on the membrane adjacent the pair of heating elements and connected between the pair of heating elements. The heating elements are further arranged in a spaced relationship, transverse to the direction of medium flow such that one heating element is upstream of the other heating element in the medium flow. The sensing element provides an electrical signal for determining the voltage across the total series resistance of the heating elements which is indicative of the medium flow magnitude, and for determining the relative resistance of the upstream heating element compared to the downstream heating element which is indicative of medium flow direction. In another aspect of the invention a system for measuring flow of a medium is disclosed.

Abstract: A method for controlling a power supply for a vehicle engine utilizes two sensors monitoring a power supply control member. In the event of a disturbance of the one of the sensor signals, the other sensor signal is used for determining the actuator control signals. If such other sensor signal exceeds a limit value, the actuator control signals are determined by a proportional-plus integral control, with the integral portion of the control being based on an operating state of the vehicle when the limit value is exceeded.

Abstract: An improved cruise control which produces a desired throttle position that is based in part on a selectively updated integral term. The integral term is only updated when the magnitude of the speed error exceeds a predefined value, thereby eliminating changes in the integral term when the speed error is smaller than the predefined threshold. In other words, the integral term is dynamic and responsive to a current error condition when the speed error magnitude exceeds the threshold, and static when the speed error is within the threshold. In this way, the operational advantages of the integral term are retained while avoiding its disadvantages, and the transition between the static and dynamic states of the integral term are smooth and seamless.

Abstract: A fuel vapor control apparatus on a motor vehicle fuel tank including a vapor storage canister, a plurality of vent valves on the fuel tank, a plurality of vapor ducts between the vent valves and the vapor storage canister, a plurality of primary liquid traps, and a secondary liquid trap which cooperates with the primary liquid traps in preventing liquid fuel leaking through the vent valves from reaching and contaminating the vapor storage canister. The primary liquid traps are segments of respective ones of the vapor ducts defining standpipes above corresponding ones of the vent valves when the fuel tank is inclined. The primary liquid traps retain liquid fuel leaking through the vent valves and drain by gravity to the fuel tank when the incline of the fuel tank is reduced to zero. The secondary liquid trap is a secondary tank on the top of the fuel tank interposed between the vapor storage canister and the segments of the vapor ducts defining the standpipes.

Abstract: A method of manufacturing an exhaust control valve includes casting first and second subhousings as separate pieces and machining smooth the inner faces of both. Each subhousing has a stem portion and a flow portion. Each flow portion defines a cylindrical bore from which a seat arc extends radially inward and approximately 180° along. The seat arc of the first subhousing lies below, and the seat arc of the second subhousing lies above, a horizontal plane that bisects the subhousings. Each seat arc has a semicircular inner sidewall that serves as a valve seat. Their inner faces facing each other, the two subhousings are mated so that their two stem portions form a stem housing and their two flow portions form a flow housing. During the mating step, the cylindrical bores are aligned to form a flow passage through the flow housing, with the two valve seats spaced equidistantly from a vertical plane defined by the inner faces along which the subhousings mate.

Abstract: In an exemplary embodiment, the present invention provides an exhaust constituent sensor comprising a planar sensing element securely held in place within a tubular inner shield by known methods. Improved thermal management of the sensor is provided by disposing a thermally conductive material between said planar sensing element and said tubular shield. In an exemplary embodiment, the thermally conductive material comprises a high thermal conductivity metal mesh which transfers heat within said tubular shield to said tubular shield via thermal conduction. The heat is then dissipated into the surrounding environment via thermal convection at an outer surface of the tubular shield. By optionally disposing an annular heat fin on the outer surface of the tubular shield, a greater amount of heat is dissipated into the surrounding environment via thermal convection in less time.

Abstract: An ion sensor glow plug assembly includes a metal shell for attachment to a cylinder head of a compression ignition engine. The ion sensor glow plug assembly also includes a center terminal at least partially disposed in the metal shell and connected to a source of power to create a heating circuit. The ion sensor glow plug assembly includes a metal glow sheath disposed at least partially in the metal shell and about the center terminal. The ion sensor glow plug assembly further includes an insulative seal disposed at least partially around the metal glow sheath to isolate the metal shell from the metal glow sheath to create an ion sensing circuit.

Abstract: A wrap spring clutch (10) including an input side rotating member (12), an output side rotating member (14), a pole piece (16) containing a cylindrical center bore (18), a coil spring (20) having a first end (22), a second end (24), an outer diameter (24A) and an inner diameter (24B), an end frame (26) and a switch element (28). The cylindrical center bore (18) maintains the outer diameter (24A) of the coil spring (20) thereby minimizing variations in the performance of the wrap spring clutch (10) and reducing the cost and difficulties associated with the manufacture and assembly of known designs.

Abstract: An improved closed-loop feedback fuel control with a model-based A/F ratio estimator, wherein the estimator, controller and portions of the model are updated on a fixed time interval basis, thereby minimizing the impact of the control on event-based throughput. Engine transport delays and oxygen sensor dynamics are modeled to estimate the sensed A/F ratio, and the estimate is compared with the sensed A/F ratio to adaptively adjust the model and to develop a closed-loop adjustment of the commanded fuel amount. The engine transport delay model is carried out on an engine event basis, but the sensor dynamics model is carried out on a time basis to accurately reflect the analog nature of the sensor. The estimator and the controller are also carried out on a time basis to reduce throughput requirements at higher engine speeds, and the control gain is scheduled to account for differences between the engine event and time update rates.

Abstract: An auxiliary canister operates with a storage canister of an evaporative emissions control system to reduce the amount of fuel vapor emitted from a vehicle to very low levels. The storage canister contains a first sorbent material and has a vent port in communication therewith. The auxiliary canister comprises an enclosure, first and second passages, a heater and a connector. Inside the enclosure, a second sorbent material is in thermal contact with the heater. Attached at one end to the bottom of the enclosure, the first passage is connectable at its other end to the vent port to allow flow between the storage and auxiliary canisters. Attached at one end to a top of the enclosure, the second passage is connectable at its other end to a vent valve of the control system to allow flow between the auxiliary canister and the vent valve. Incorporated into the enclosure, the connector is used to convey electrical power from the vehicle to the heater.

Abstract: A secondary fuel pump assembly for a fuel tank in a vehicle includes a reservoir adapted to be disposed in the fuel tank having a top defining an overflow fuel level of the reservoir. The secondary fuel pump assembly also includes a conduit conducting return fuel from an engine of the vehicle to the reservoir and a jet pump having a discharge outlet in the reservoir and an inlet operatively connected to the conduit. The secondary fuel pump assembly includes an overflow fuel member defining a flow path for overflow of fuel in the reservoir and a guide member extending into the overflow fuel member and having at least one aperture extending therethough. The secondary fuel pump assembly further includes a guide disposed over the guide member and movable relative thereto to open and close the at least one aperture and a float connected to the guide to move the guide as a fuel level rises and falls in the reservoir.

Abstract: The power generation system and method of the present invention employ a solid oxide fuel cell which reforms fuel to a degree which is controlled by the amount of fuel introduced to the solid oxide fuel cell. The effluent is directed preferably through a heat exchanger and then into an engine. This hybrid system more efficiently produces energy, both mechanical and electrical, over conventional systems.