Fluid pump control apparatus

• US 20080230035A1
• Filed: 02/27/2008
• Published: 09/25/2008
• Est. Priority Date: 03/23/2007
• Status: Active Grant

• Current Assignee: Aisan Kogyo Kabushiki Kaisha
• Original Assignee: Aisan Kogyo Kabushiki Kaisha
• Inventors: Inoue, Tetsuji
• Granted Patent: US 7,677,224 B2
• Time in Patent Office: Days
• US Class Current: 123/497
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 33/003 Controlling the feeding of liquid fuel from storage containers to carburettors or fuel-injection apparatus control of electrical fuel pumps F02D41/3082, controlling fuel flow to a common rail F02D41/3845; Failure or leakage prevention; Diagnosis or detection of failure; Arrangement of sensors in the fuel system; Electric wiring; Electrostatic discharge
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02M 37/08 electrically driven
• CPC Class Codes: F02M 37/10 submerged in fuel, e.g. in reservoir
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: H02P 7/29 using pulse modulation

Abstract

A fuel supply system comprises an engine control unit (ECU), a fuel pump with a built-in pump motor which is PWM controlled based on a control signal from the ECU, a pump controller for controlling supply of electric power to the pump motor, and sensors for detecting an operating state of the engine. A control section of the pump controller controls to change a frequency to be lower as a duty ratio of a PWM control signal to operate a power transistor of an output circuit is higher and inversely to change the frequency to be higher as the duty ratio is lower.

Claims

1. A fluid pump control apparatus comprising:

a main controller for controlling a vehicle drive source;

a fluid pump internally provided with a motor to be PWM controlled based on a control signal from the main controller;

a sub-controller for controlling supply of electric power to the motor of the fluid pump; and

state detecting means for detecting an operating state of the vehicle drive source,

wherein the sub-controller includes frequency control means for changing a frequency of the PWM control signal to control the fluid pump based on a detection result of the state detecting means.

2. The fluid pump control apparatus according to claim 1, wherein the frequency control means controls to change the frequency of the PWM control signal to be lower as output of the drive source detected by the state detecting means is larger and inversely to change the frequency of the PWM control signal to be higher as the output of the drive source detected by the state detecting means is smaller.

3. The fluid pump control apparatus according to claim 1, wherein the frequency control means controls change the frequency of the PWM control signal to be lower as a duty ratio for driving the motor is higher and inversely to change the frequency of the PWM control signal to be higher as the duty ratio is lower.

4. The fluid pump control apparatus according to claim 3, wherein the frequency control means determines a duty ratio based on a command from the main controller and also determines the frequency of the PWM control signal based on map data describing a relationship between the duty ratio and the frequency of the PWM control signal.

5. The fluid pump control apparatus according to claim 1, wherein

the vehicle drive source is a combination of an engine and an electric motor.

6. The fluid pump control apparatus according to claim 1, further comprising vehicle-speed detecting means for detecting vehicle running speed,

wherein the sub-controller causes the frequency control means to set the frequency of the PWM control signal to be lower than a predetermined value in an audible range when it is determined that the vehicle running speed detected by the vehicle-speed detecting means is larger than zero and smaller than the predetermined value.

7. The fluid pump control apparatus according to claim 6, wherein

the predetermined value of the running speed is 20 km/h or lower.

8. The fluid pump control apparatus according to claim 6, further comprising low-frequency setting permission means for permitting the frequency control means to set the frequency of the PWM control signal to be lower than the predetermined value, and

wherein the sub-controller causes the frequency control means to set the frequency of the PWM control signal to be lower than the predetermined value in the audible range only if the low-frequency setting permission means permits setting of the PWM control signal to a low frequency.

9. The fluid pump control apparatus according to claim 6, wherein

the predetermined value of the frequency in the audible range is 15000 Hz or lower.

10. The fluid pump control apparatus according to claim 6, wherein the predetermined value of the frequency in the audible range is 5000 Hz or lower.

11. A fuel pump control apparatus comprising:

a fuel tank for storing fuel;

a fuel pump placed in the fuel tank to supply the fuel from the fuel tank to an engine;

an engine controller arranged to control operation of the engine;

a fuel pump controller arranged to PWM control supply of electric power to the fuel pump based on a control signal from the engine controller; and

state detecting means for detecting a state of the engine,

wherein the fuel pump controller includes frequency control means for changing a frequency of a PWM control signal for controlling the fuel pump based on a detection result of the state detecting means, and

the frequency control means controls to change the frequency of the PWM control signal to be lower as output of the engine detected by the state detecting means is larger and inversely to change the frequency of the PWM control signal to be higher as the output of the engine detected by the state detecting means is smaller.