Abstract: A valve assembly (14) has an internal main flow passage through a valve body (24) between a first port (25) and a second port (26), an electric actuator (30), and a valve (86) operated by an armature (58) of the actuator to selectively open and close the passage. A force-balancing mechanism (92) applies to the valve (86) a force that opposes force created by pressure differential between the first and second ports. This mechanism includes an internal chamber (126) bounded in part by a fluid-impermeable movable wall (94) that extends between and is sealed to both the body (24) and the valve (86), and a communication passage (110, 112) that communicates one of the ports (26) to the chamber space when the valve is closing the passage. The valve (86) has a head part (88) and a seal part (90) joined together. The seal part seals the head part to the valve seat (29) when the valve is closing the passage. A retainer part (116) holds the inner margin of the movable wall sealed on the head part.

Abstract: An internal combustion engine intake manifold has a wall separating internal manifold space from an external space. The body of a purge valve for purging fuel vapors from an evaporative emission space of a fuel storage system for an engine is disposed in the external space mounted on the wall such that a portion of the purge valve body that contains an outlet port confronts the wall, and the portion of the wall confronted by that portion of the purge valve body contains an opening through which the outlet port communicates with the internal manifold space. The outlet port may be a nipple which passes through the opening in the manifold wall to communicate the outlet port with the internal manifold space.

Abstract: A module for an on-board evaporative emission leak detection system that detects leakage from an evaporative emission space of a fuel system of an automotive vehicle. Interior space of the module's enclosure is communicated to atmosphere. A pump is disposed within space and has an inlet communicated to the interior space and a flow passage at its outlet to allow the pump to create pressure in the evaporative emission space suitable for performance of a leak test. A vent valve is disposed within space and is selectively operable to vent and not vent the flow passage to space. An electromagnet actuator has a single electric coil that operates both the pump and the vent valve by cantilever-mounted armatures responsive to electric control current in the coil having a first current component for controlling the pump and a second current component for controlling the vent valve.

Abstract: A valve assembly (14) has an internal main flow passage through a valve body (24) between a first port (25) and a second port (26), an electric actuator (30), and a valve (86) operated by an armature (58) of the actuator to selectively open and close the passage. A force-balancing mechanism (92) applies to the valve (86) a force that opposes force created by pressure differential between the first and second ports. The valve has cushion media (76, 80, 142) that cushions impact of lateral displacements of the armature and cushion media (76) for cushioning axial impact between the armature and stator. An overmold (32) encloses internal parts, and one of the ports contains sonic nozzle structure (28). the valve exhibits improved noise attenuation, durability, and performance.

Abstract: An electric vacuum regulator has an enclosure containing an interior space and a solenoid assembly. An inlet port communicates the interior space to source vacuum. Vacuum communicated to the interior space is vented through a filter to atmosphere. Regulated vacuum is provided through an outlet port. A valve mechanism operated by the solenoid assembly selectively vents vacuum from the inlet port to the vent port and thereby creates regulated vacuum at the outlet port. The valve mechanism includes a valve element and a seat element. The latter has a continuous annular seat surface which circumscribes a vent path from the interior space to atmosphere that is opened and closed by the valve element, and a further surface which is disposed radially outward of the seat surface and against which the valve element also seats when closing the vent path. A groove that separates the further surface from the seat surface is vented to the interior space by through-holes in the valve element.

Abstract: An on-board evaporative emission leak detection system has a module for detecting leakage from an evaporative emission space of a fuel system of an automotive vehicle. Interior space of the module's enclosure is communicated to atmosphere. A pump is disposed within space and has an inlet communicated to the interior space and a flow passage at its outlet to allow the pump to create pressure in the evaporative emission space suitable for performance of a leak test. A vent valve is disposed within space and is selectively operable to vent and not vent the flow passage to space. An electromagnet actuator has a single electric coil that operates both the pump and the vent valve by cantilever-mounted armatures responsive to electric control current in the coil having a first current component for controlling the pump and a second current component for controlling the vent valve.

Abstract: A system and method for an engine-powered automotive vehicle evaporative emission control system having an evaporative emission space for containing volatile fuel vapors, and a leak detection system for detecting leakage from the evaporative emission space. At the beginning of a test, an initial test pressure that differs sufficiently from atmospheric pressure to allow a leak to be detected is created in the evaporative emission space. After attainment of the initial test pressure in the evaporative emission space, the initial test pressure is restored whenever the pressure changes by a predetermined amount due to a leak. The test includes measuring at least one of: a time interval required for pressure in the evaporative emission space to change from the initial test pressure by the predetermined amount; and b) a time interval required to restore the initial test pressure in the evaporative emission space.

Abstract: An on-board diagnostic system for an evaporative emission control system of an internal combustion engine powered vehicle employs a leak detection module that is fluid connected in a vent passage for the evaporative emission space. The leak detection module contains an electric motor driven impeller, a solenoid operated valve assembly that is selectively operable to three positions, and a pressure-responsive switch whose switching characteristic possesses hysteresis corresponding to an upper regulating limit and a lower regulating limit.

Abstract: Vent control valving is described for an automotive fuel vapor recovery system, in which a baffle arrangement prevents or otherwise restricts liquid fuel from entering a vent passage to a charcoal canister. A sealing arrangement prevents or otherwise restricts the escape of fuel when the vehicle is turned at a sufficient rate of turn, operated on a sufficient incline, or rolled over, and prevents overfilling of the tank, which could allow liquid fuel to enter the vent passage. In one embodiment, a differential pressure is developed across a diaphragm during refueling which unseats the diaphragm from a seat to allow unrestricted venting during refueling, restricted venting is established whenever the diaphragm is seated to limited the flow of vapors to the canister.

Abstract: A vapor collection canister vent valve contains both an electric pressure sensor for measuring evaporative emission space pressure during a diagnostic test and an electric actuator for operating the vent valve closed during a diagnostic test. Use of the valve in an evaporative emission control system reduces the number of connections, both electrical and fluid, that are required to install the valve in a system. The remote location of the pressure sensor damps the effect of pressure transients, such as those due to tank fuel slosh, on the sensor.

Abstract: The purge valve embodies a solenoid that has a linear force vs. current characteristic acting on the armature. Effects of hysteresis are minimized by certain constructional features and the manner of operating the valve by an associated control circuit.

Abstract: The solenoid-operated valve's outlet port (26) is a tube having a thread (60) threaded into a threaded socket (66, 68) in a valve housing member (34). The valve seat (62) is at an end of the tube, and the extent to which the tube is threaded into the socket sets the position of the seat within the housing's interior (42). Once the position has been set, an adhesive sealant is applied and upon setting, forms a plug (164) which locks the tube in place and seals between the tube and the socket. The valve element (33) is spring-biased (160) closed on the seat, but when the solenoid is energized, it is unseated by the solenoid's armature (122) to which it is attached. The solenoid's stator (86, 88, 90) includes an annular shunt (90) which forms an air gap to the armature for the magnetic circuit that acts on the armature to unseat the valve element and which also holds the outer margin (154) of a diaphragm (124) sealed against the solenoid. The inner margin of the diaphragm is sealed to the armature.

Abstract: A purge valve has a novel seal element on the head end of a reciprocating valve member that features a frustoconical projection for improved noise attenuation and sealing against a flat annular surface of a valve seat. As the projection comes to closed position against the seat surface, it flexes slightly so that the sealing diameter of its rounded free end contracts, to wipe the seat surface. In one embodiment, the seal element is provided with another projection that absorbs impact upon the valve member coming to maximum open position. In another embodiment, an elastomeric damper element is provided on an end of a pole piece of a solenoid assembly to absorb impact of the valve member as it comes to its maximum open position.

Abstract: The purge valve embodies a solenoid that has a linear force vs. current characteristic acting on the armature. Effects of hysteresis are minimized by certain constructional features and the manner of operating the valve. Several embodiments are disclosed.

Abstract: A vacuum sustaining valve (VSV) for temporarily sustaining at least some engine intake manifold vacuum to an EGR valve when engine intake manifold vacuum falls below a predetermined value. The VSV has an inlet port, an outlet port, and a flow path between the two ports. A check valve is disposed with the flow path and is selectively positioned in accordance with manifold vacuum. When manifold vacuum is above a predetermined magnitude, the check valve is positioned to allow bi-directional flow between the two ports. When manifold vacuum is below the predetermined magnitude, the check valve is positioned to function as a check that allows vacuum to pass from the inlet port to the outlet port, but not in the opposite direction.

Abstract: An EGR valve is well-suited for use in a diesel engine by employing a butterfly-type valve operated by a torque motor. Sealing of the butterfly blade to the wall of the passage through the valve body utilizes a sealing ring that is mounted in a groove of the passage wall. The blade and the sealing ring are self-aligned at assembly, and the groove is cooperatively defined by two body segments that are fitted axially together to capture the sealing ring. Two additional rings are used between the sealing ring and the sides of the groove. In certain embodiments, the axis of the passage in the vicinity of the groove is straight; in others, it has a 45 degree offset so that portions of the axis to opposite sides of the groove are non-collinear.

Abstract: An electrically operated EGR valve has a pintle for opening and closing the valve. The pintle is actuated by an linear actuator to open and close two ports which are connected to the outlet of the valve. The pintle has a frustoconical surface which mates with the two ports. The input passageway to the EGR valve is in fluid communication with both sides of the pintle which are the sides taken in direction of the movement of the linear actuator. The pintle being pressure-balanced when the electrically operated linear actuator attempts to move the pintle to either further open or further close the ports, the pintle is more responsive without increasing the size of the actuator.

Abstract: A canister purge flow regulator for regulating the purging of a fuel vapor collection canister to the engine. The purge flow regulator has in the purge flow path, two parallel branch paths, and an associated valve for each branch path. The two valves are operatively related for motion in unison by an actuating mechanism. When the two valves are closed, manifold vacuum is applied in opposite senses, thereby canceling the effect of variations in manifold vacuum on opening of the purge flow regulator. The actuating mechanism senses the differential pressure drop across an orifice in the flow path to automatically adjust the valves to maintain the purge flow commanded by an electric signal input to a solenoid.

Abstract: An on-board diagnostic system for an evaporative emission control system of an internal combustion engine powered vehicle employs a positive displacement reciprocating pump to create in evaporative emission space a pressure that differs significantly from ambient atmospheric pressure. The pump is powered by using engine intake manifold vacuum to force an intake stroke during which both an internal spring is increasingly compressed and a charge of ambient atmospheric air is created in an air pumping chamber space. Vacuum is then removed, and the spring relaxes to force a compression stroke wherein a portion of the air charge is forced into the evaporative emission space. The pump operation is under the control of a computer that contains an algorithm for operating the pump in particular modes of operation to arrive at a decision concerning integrity of the evaporative emission space against leakage.

Abstract: Differential flow sensing through respective flow path portions of a system for detecting leakage from an evaporative emission control system. A series flow path comprises a first flow sensor for sensing the entire output flow of an impeller pump used to positively pressurized the system under test, a second sensor in a portion of the series flow path that is downstream of the first flow sensor, and a calibrated orifice downstream of the second flow sensor. A branch circuit to the evaporative emission space under leakage test tees into the aforementioned series circuit between the first flow sensor and the second flow sensor. A differential amplifier receives signal from the respective sensors. Any difference in sensed flows, once the pressure has been brought to a predetermined pressure, is output by the differential amplifier to signify leakage in an amount correlated with the sensed difference in the flows.