Control system for fuel pump for internal combustion engine

• US 4,577,604 A
• Filed: 09/28/1984
• Issued: 03/25/1986
• Est. Priority Date: 09/28/1984
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hara, Yoichi, Seimiya, Yasuo
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/655,554
• Time in Patent Office: 543 Days
• Field of Search: 123/397, 123/358
• US Class Current: 123/397
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02M 2037/085 Electric circuits therefor
• CPC Class Codes: F02M 37/08 electrically driven

Abstract

A fuel pump control system controls the operating speed of the fuel pump to control the fuel pressure in a fuel supply circuit for a internal combustion engine. The control system includes a main control circuit constantly connecting a fuel pump driver to a vehicle battery which acts as a power source and a normally-open auxiliary circuit. The main control circuit adjusts the power supply to the fuel pump driver to adjust the operating speed of the fuel pump to either a first maximum or a second minimum speed. The auxiliary circuit establishes electrical communication between the fuel pump driver and the battery when a demand for increasing of the fuel pressure in the supply line and thus for enrichment of the air/fuel mixture beyond a predetermined value is detected on the basis of one or more preselected engine operating parameters.

Claims

1. A control system for a fuel pump in a fuel supply system for an internal combustion engine comprising:

a fuel pump driver associated with said fuel pump to drive the latter at a controlled speed;

a sensor for monitoring a preselected engine operating parameter and producing a sensor signal indicative of the engine operating parameter;

a controller responsive to said sensor signal for deriving a desired fuel pump speed value on the basis of the value of said sensor signal and operating said fuel pump driver to drive said fuel pump in accordance with said desired speed in one of a predetermined speed range defined by a first maximum speed and a second minimum speed, and a predetermined ultimate speed in excess of said first speed and said controller being responsive to the sensor signal representative of a desired fuel pump speed in excess of said first maximum speed to operate said fuel pump driver to drive said fuel pump at said ultimate speed.

2. The control system as set forth in claim 1, which further comprises a first power supply line for supplying said fuel pump driver with electric power sufficient to drive said fuel pump within said predetermined speed range between said first and second speeds, and a normally-open second power supply line supplying said fuel pump driver with electrical power sufficient to drive said fuel pump at said ultimate speed, said second power supply line being closed in response to a control signal produced by the controller when said desired speed exceeds said first speed.

3. The control system as set forth in claim 2, wherein said fuel pump driver is an electric motor, the operating speed of which depends upon the voltage supplied thereto.

4. A control system for a fuel pump in a fuel supply system for an internal combustion engine comprising:

a fuel pump driver associated with said fuel pump to drive the latter at a controlled speed;

a sensor for monitoring a preselected engine operating parameter and producing a sensor signal indicative of the engine operating parameter;

a controller responsive to said sensor signal for deriving a desired fuel pump speed value on the basis of the value of said sensor signal and operating said fuel pump driver to drive said fuel pump in accordance with said desired speed in one of a predetermined speed range defined by a first maximum speed and a second minimum speed, and a predetermined ultimate speed in excess of said first speed and said controller being responsive to the sensor signal representative of a desired fuel pump speed in excess of said first maximum speed to operate said fuel pump driver to drive said fuel pump at said ultimate speed;

a first power supply line for supplying said fuel pump driver with electric power sufficient to drive said fuel pump within said predetermined speed range between said first and second speeds; and

a normally-open second power supply line supplying said fuel pump driver with electrical power sufficient to drive said fuel pump at said ultimate speed, said second power supply line being closed in response to a control signal produced by the controller when said desired speed exceeds said first speed;

wherein said fuel pump driver is an electric motor, the operating speed of which depends upon the voltage supplied thereto; and

wherein said second power supply line has a lower effective resistance than said first power supply line.

5. The control system as set forth in claim 4, wherein said controller responds to closure of a starter switch to calculate a desired fuel pump speed in excess of said first speed.

6. The control system as set forth in claim 4, wherein said controller responds to a signal from a fuel temperature sensor to calculate a desired fuel pump speed in excess of said first speed whenever the fuel temperature detected by said fuel temperature sensor is higher than a given temperature threshold.

7. The control system as set forth in claim 5, which further comprises means for holding said desired fuel pump speed in excess of said first speed for a given period of time.

8. The control system as set forth in claim 4, wherein said second power supply line includes a normally-open relay circuit closed by said controller when the desired fuel pump speed exceeds said first speed.

9. The control system as set forth in claim 8, wherein said relay circuit is disposed near said fuel pump so as to be connected to said fuel pump driver via the shortest possible wiring.

10. A control system for a fuel pump in a fuel supply system for an internal combustion engine comprising:

a fuel pump driver associated with said fuel pump to drive the latter at a controlled speed;

a sensor for monitoring a preselected engine operating parameter and producing a sensor signal indicative of the engine operating parameter; and

a controller responsive to said sensor signal for deriving a desired fuel pump speed value on the basis of the value of said sensor signal and operating said fuel pump driver to drive said fuel pump in accordance with said desired speed in one of a predetermined speed range defined by a first maximum speed and a second minimum speed, and a predetermined ultimate speed in excess of said first speed and said controller being responsive to the sensor signal representative of a desired fuel pump speed in excess of said first maximum speed to operate said fuel pump driver to drive said fuel pump at said ultimate speed;

wherein said controller responds to closure of a starter switch to calculate a desired fuel pump speed in excess of said first speed.

11. The control system as set forth in claim 10, further comprising a first power supply line for supplying said fuel pump driver with electric power sufficient to drive said fuel pump within said predetermined speed range between said first and second speeds, and a normally-open second power supply line supplying said fuel pump driver with electrical power sufficient to drive said fuel pump at said ultimate speed, said second power supply line being closed in response to a control signal produced by the controller when said desired speed exceeds said first speed.

12. The control system as set forth in claim 10, which further comprises means for holding said desired fuel pump speed in excess of said first speed for a given period of time.

13. A control system for a fuel pump in a fuel supply system for an internal combustion engine comprising:

a fuel pump driver associated with said fuel pump to drive the latter at a controlled speed;

a sensor for monitoring a preselected engine operating parameter and producing a sensor signal indicative of the engine operating parameter; and

a controller responsive to said sensor signal for deriving a desired fuel pump speed value on the basis of the value of said sensor signal and operating said fuel pump driver to drive said fuel pump in accordance with said desired speed in one of a predetermined speed range defined by a first maximum speed and a second minimum speed, and a predetermined ultimate speed in excess of said first speed and said controller being responsive to the sensor signal representative of a desired fuel pump speed in excess of said first maximum speed to operate said fuel pump driver to drive said fuel pump at said ultimate speed;

wherein said controller responds to a signal from a fuel temperature sensor to calculate a desired fuel pump speed in excess of said first speed whenever the fuel temperature detected by said fuel temperature sensor is higher than a given temperature threshold.

14. The control system as set forth in claim 13, further comprising a first power supply line for supplying said fuel pump driver with electric power sufficient to drive said fuel pump within said predetermined speed range between said first and second speeds, and a normally-open second power supply line supplying said fuel pump driver with electrical power sufficient to drive said fuel pump at said ultimate speed, said second power supply line being closed in response to a control signal produced by the controller when said desired speed exceeds said first speed.