Motor driven fuel pump and control system for internal combustion engines
First Claim
1. A motor driven fuel system including a supply line and a fuel source for supplying fuel under pressure to an internal combustion engine, comprising a sensing apparatus to sense the pressure of the fuel flow to said engine, and a control unit operating said fuel source at a selected constant power input with the pressure at or below a first selected level and operating said fuel source with at least a selected lesser power input including a constant minimum power input with the pressure at or above a second selected level and operating said fuel source with a varying power input with the pressure between said first and second selected levels.
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Accused Products
Abstract
An in-tank motor-pump unit includes a motor driven gear pump, a pressure transducer, and a control module as a single integrated package establishing fuel flow at a constant pressure by creating a pulse-modulated motor drive having a fixed "off" and a variable "on" period. A permanent magnet DC motor drives a rotary pump with the required torque operating over the specified speed range and without stalling out at low flow demand. An integrated circuit board includes an IC timing chip, operating in an astable mode, has an input connected to the transducer and an output connected to a MOSFET switch which connects the motor to a power supply. A series resistor connects an amplified voltage signal of the transducer to charge the capacitor and discharge resistor separately connects the capacitor to the input of the timing chip to generate a constant "off" period and a variable operative "on" period of the MOSFET. A slight recycle fuel flow is established with substantially equal "on" and "off" periods at substantially zero fuel flow.
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Citations
26 Claims
- 1. A motor driven fuel system including a supply line and a fuel source for supplying fuel under pressure to an internal combustion engine, comprising a sensing apparatus to sense the pressure of the fuel flow to said engine, and a control unit operating said fuel source at a selected constant power input with the pressure at or below a first selected level and operating said fuel source with at least a selected lesser power input including a constant minimum power input with the pressure at or above a second selected level and operating said fuel source with a varying power input with the pressure between said first and second selected levels.
- 6. A motor driven fuel supply system comprising a motor-pump unit including a motor and a pump connected to an inlet end of said motor and said motor having an outlet end establishing a pressurized output, an outlet passageway unit connected to said outlet end, a control unit secured in abutting relation to the said motor, said control unit having a sealed housing with a high heat transfer wall secured in tight abutting engagement with said motor for optimum heat transfer, said control unit including a pressure transducer aligned with said outlet end of said motor, said motor having an outlet end frame having a sensing passageway coupled to said outlet end and providing an input signal to said pressure transducer, said pressure transducer having a housing secured within said control unit and having a sensing member extending outwardly therefrom into said sensing passageway, said control unit having a mounting member secured to said housing and having a power input unit connected to said mounting member for supplying of power to said control unit, said control unit having a motor power terminal unit for supplying power from within said control unit to said motor, said control unit including a electronic circuit means connected to said pressure transducer and to said motor power terminal unit for providing said power to said motor in accordance with the output of said pressure transducer, said control circuit having a power section and a control section interconnected to each other and to said pressure transducer and to said power terminal unit, said control section being mounted to a supporting base and said base wall secured in tight abutment to said heat transfer wall.
- 9. A control circuit for energizing of a motor pump unit establishing and maintaining fuel flow therefrom at a selected output pressure range, comprising a pressure transducer having an input configured for servicing the fuel flow from the motor pump unit and operable to establish an electrical pressure related signal proportional to the fuel pressure from said motor pump unit, an amplifying circuit for receiving of said pressure related signal and establishing an output control voltage related thereto, a timing circuit adapted to establish an essentially constant output voltage in response to a first voltage input signal and an essentially minimal output voltage in response to a second input voltage signal, said timing circuit having an input connected to said output of said amplifying circuit for establishing an output related to said output control voltage, said timing circuit including a rapid acting solid state switch connected in an output circuit with said motor and operable to establish a continuous constant voltage level to said motor with said pressure at or below said selected pressure and a pulse width modulated voltage to said motor with said pressure above said selected level.
- 12. A motor-driven fuel supply apparatus for an internal combustion engine, comprising a fuel pump unit having an output line, a motor connected to operate said fuel pump and establishing a pressurized fuel flow in said output line, a pressure transducer providing an output voltage signal related to the output pressure of said pump unit, an amplifier for amplifying of said voltage signal from said transducer, a control circuit having an output connected to said motor and a timing circuit having an input connected to said amplified voltage signal and operating to maintain an essentially constant output power to said motor with said pressure transducer establishing a voltage signal in accordance with a pressure equal to or less than a first selected output pressure in said output line and reducing said output power including a constant reduced output power for a second selected pressure above said first selected output pressure.
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25. A method for maintaining a fuel supply at a substantially constant pressure to an internal combustion engine with a motor pump unit having the capability of establishing a minimum selected fuel pressure with a selected voltage applied to said motor, comprising sensing said fuel pressure and establishing a control signal related thereto, comparing said sensed signal with a reference signal corresponding to said substantially constant pressure, supplying full power to said motor pump unit with said control signal at or below said minimum selected pressure level and supplying a pulse width modulated voltage to said motor when said sensed fuel pressure is at or above said minimum selected pressure level and thereby maintaining said substantially constant fuel supply pressure to said engine.
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26. A method for maintaining a fuel supply at a substantially constant pressure to an internal combustion engine with a motor pump unit having the capability of establishing a minimum selected fuel pressure with a selected voltage applied to said motor, comprising sensing said fuel pressure and continuously supplying a constant input power to said motor pump unit with the fuel pressure at or below said selected fuel pressure, and pulse width modulating said power supplied to said motor pump with a fixed "off" period and a variable "on" period to maintain the substantially constant pressure and flow from the unit with said fuel pressure above said minimum selected fuel pressure.
Specification