Abstract: A system for providing the fuel requirements of an engine based on an estimated value of the temperature of the intake region of the engine.

Abstract: Induction air flow to an internal combustion engine is controlled or measured by a butterfly valve which extends into undercut recesses on opposite sides of the valve bore. The valve member rotates in excess of 90.degree. between its minimum air flow position and its maximum air flow position and offers a relatively low normalized change in the flow area around the valve.

Abstract: A dual fuel supply system for an automotive engine has a fuel tank adapted to contain both methane and propane at pressures up to 17,000 kPa. A switching valve assembly directs methane to the engine fuel metering apparatus when the fuel tank pressure exceeds 1400 kPa and directs propane to the engine fuel metering apparatus when the fuel tank pressure is less than 1400 kPa.

Abstract: A pressure transducer of the manometer type comprises two interconnected columns of liquid with means for applying differential pressure across the columns. The liquid is a magnetic liquid and a magnetic field is impressed on the columns to attract the liquid by magnetic force to a reference position. The applied differential pressure acts counter to the magnetic force to shift the columns so that their difference in lengths reflects the pressure. By using capacitor plates to define the walls for the liquid columns and a magnetic liquid which is a dielectric, the capacitance between the plates is a function of the column lengths and therefore is a function of the applied differential pressure.

Abstract: To measure the mass air flow in the induction passage of an engine, a small venturi located centrally in the passage serves as an air sampling tube. A slotted aperture in the wall of the tube at the venturi throat allows a hot film sensor to extend into the venturi throat from a support such as a printed circuit board mounted outside the venturi. The film sensor is in the form of a loop supported only at its ends on the support. The loop comprises a substrate of flexible insulating film material coated with an electrical resistance layer forming the active element of the sensor. The loop has a major dimension extending arcuately and transversely of the air flow through the venturi and a minor dimension extending parallel to the air flow.

Abstract: A balanced dual valve member is positioned by a pressure responsive diaphragm and a solenoid reference device to provide an air flow through an engine throttle bypass passage which does not vary with changes in engine manifold pressure.

Abstract: In an internal combustion engine, recirculation of exhaust gases is controlled to maintain the control pressure in a zone of the recirculation passage proportional to a reference pressure and thus to provide exhaust gas recirculation as a proportion of induction air flow. A duty cycle modulated valve controls an exhaust back-pressure port and an atmospheric pressure port to create the reference pressure, whereby the proportion of exhaust gases recirculated is established by the duty cycle and is independent of the induction air flow.

Abstract: A motor vehicle combustion engine has an exhaust gas recirculation system in which the flow of recirculated exhaust gas is controlled through an orifice having exhaust back pressure on one side and a control pressure on the other as determined by an EGR valve. A pressure transducer compares the control pressure with a reference pressure provided in part by an electromagnetic force to provide an operating pressure for positioning the EGR valve to obtain a control pressure equal to the reference pressure. At engine idle, the EGR valve is closed and the control pressure is equal to the exhaust back pressure. When this condition exists, the electromagnetic force is varied until the reference pressure is substantially equal to the control pressure, the magnitude of the electromagnetic force being a measure of the control pressure at idle and which comprises a calibration value that is stored for use as a reference for controlling exhaust back pressure during other engine operating conditions.

Abstract: An engine charge forming device controls the fuel metering orifice area in proportion to the throttled air flow area of the induction passage and controls the pressure drop across the fuel metering orifice in proportion to a vacuum signal which is substantially independent of the compressibility effects of throttled air flow; fuel flow is thereby proportioned to air flow throughout the range of engine operating conditions. Adjustments are provided for varying the fuel metering orifice area to set minimum and maximum fuel flows, and controls are provided for modifying the vacuum signal to vary air-fuel ratio.

Abstract: A valve controlling the rate of air flow from a supply pump to an engine exhaust system directs the air flow to the exhaust system through an orifice in a diaphragm valve which is associated with a valve seat separating the air supply from an excess air discharge port. The pressures acting on the diaphragm displace the diaphragm from the valve seat the amount necessary for the rate of air flow through the orifice to the exhaust system to be proportional to the rate of exhaust flow through the exhaust system and for the excess air flow supplied by the pump to be discharged through the excess air port.

Abstract: During operation of an internal combustion engine at low temperatures, the carburetor choke is closed to the extent necessary to provide the fuel which will maintain the mean effective pressure of combustion equal to the mean effective pressure occurring during operation at normal temperatures. The torque produced during low temperature engine operation is thus maintained equal to the torque produced during operation at normal temperatures.

Abstract: In a carburetor, a linear motor assembly urges the metering apparatus against a biasing spring with a force related to the linear motor current, and an adjusting screw grounds a portion of the active turns of the biasing spring to vary its spring rate and thereby establish the position of the metering apparatus and thus the carburetor fuel flow for a selected linear motor current.

Abstract: An engine charge forming device controls the fuel metering orifice area in proportion to the throttled air flow area of the induction passage and controls the pressure drop across the fuel metering orifice in proportion to a vacuum signal which is substantially independent of the compressibility effects of throttled air flow; fuel flow is thereby proportioned to air flow throughout the range of engine operating conditions. Adjustments are provided for varying the fuel metering orifice area to set minimum and maximum fuel flows, and controls are provided for modifying the vacuum signal to vary air-fuel ratio.

Abstract: A command signal drives a carburetor metering valve to provide the carburetor fuel flow which will establish a desired air-fuel ratio; simultaneously, the command signal drives a control unit which purges fuel vapor from a fuel vapor storage region. The control unit minimizes purge flow when either maximum fuel flow or minimum fuel flow is commanded and maximizes purge flow when an intermediate fuel flow is commanded; accordingly, fuel vapor is purged from the vapor storage region only when the purge flow cannot unduly enrich or unduly lean the mixture.

Abstract: An electronic throttle body fuel injection system in which a fuel pump delivers fuel at constant flow and pressure to a jet in a pressure controlled chamber which is continuously ported upstream of the jet discharge to a fuel nozzle in a throttle bore and is periodically ported to bypass back to the pump fuel supply by an electrically operated on-off valve. The valve has an atmospheric reference pressure bias and is operable with a fuel demand signal from a conventional electronic fuel injection control system to open and close for time periods which vary with the fuel signal to vary the pressure in the controlled chamber between a value which induces fuel flow through the fuel nozzle for such time periods and a value which does not to thereby effect a metered flow to the fuel nozzle according to the fuel demand signal to provide the desired air/fuel ratio for optimum engine running conditions.

Abstract: A regulating unit senses the pressures in two zones of a recirculation passage to create a control pressure, and a transducer regulates an operating pressure which positions a control valve to provide exhaust gas recirculation at rates which establish the pressures in the zones necessary to maintain the control pressure equal to a reference pressure. Exhaust gas recirculation thus varies with engine exhaust backpressure and accordingly is a proportion of induction air flow with the proportion being ruled by the regulating unit.

Abstract: A switching member simultaneously establishes a reference pressure and selects the pressure in one of two zones of a recirculation passage to create a control pressure, and a transducer regulates an operating pressure which positions a control valve to provide exhaust gas recirculation at rates which establish the pressures in the zones necessary to maintain the control pressure equal to the reference pressure. Exhaust gas recirculation thus varies with engine exhaust backpressure and accordingly is a proportion of induction air flow with the proportion being ruled by the switching member.

Abstract: In a carburetor, an electromagnet energized according to a pulse width modulated duty cycle has a stationary pole member which drives a pair of magnetically responsive valves--one or both being permanently magnetic--to control fuel flow through a main metering orifice and air flow through an idle air bleed.

Abstract: A system for positioning an engine control element has a sensor measuring a value corresponding to the actual position of the element, a reference providing a command value establishing the proper position for the element, an electronic control which compares the measured value with the command value, and an actuator including a fluid pressure responsive motor for moving the element and a pressure regulator directed by the electronic control to regulate the fluid pressure delivered to the motor and cause the motor to move the control element to the proper position. The pressure regulator has a coil energized by the electronic control and a valve member which floats between a regulated-pressure-reducing bias caused by the magnetic flux created in the coil and a regulated-pressure-increasing bias caused by a varying but uncontrolled pressure differential.

Abstract: An electromagnetic vacuum regulator responds to an electrical signal to supply a regulated vacuum output to vacuum sensitive air-fuel ratio control means in an engine carburetor, the air-fuel ratio control means providing a leaner air-fuel ratio with increasing manifold vacuum. The vacuum regulator includes a regulated vacuum output connected to the air-fuel ratio control means, a constant pressure input connected to a source of constant low vacuum and a variable pressure input normally supplied with the engine manifold vacuum so that the regulated output vacuum is normally always greater than the constant vacuum supplied to the constant pressure input. The carburetor throttle mechanism, however, includes means to actuate a valve opening the variable pressure inlet to the atmosphere during wide open throttle so that the regulated vacuum outlet supplies atmospheric pressure for a richer than normal air-fuel ratio regardless of the electric signal.