Fuel supply device

Patent metadata

Field	Value
Publication number	US-9732694-B2
Application number	US-201314434838-A
Country	US
Kind code	B2
Filing date	Oct 9, 2013
Priority date	Oct 15, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A fuel supply device ( 1 ) has a valve ( 13 ) in a fuel passage between a fuel pump ( 3 ) and an engine ( 5 ). In a storage portion of an ECU ( 18 - 21 ) is stored a relationship between a fuel pressure and a flow rate, which are required by the engine, and voltage which is supplied to a motor ( 7 ). The ECU senses voltages V 26 , V 27 , V 28 supplied to the motor from a controller ( 22 ) when the valve is opened from change points C 1 ′, C 2 ′, C 3 ′ at which a characteristic between the voltage and the current which are supplied to the motor ( 7 ) is changed. Then, the ECU corrects the voltage stored in the storage portion on the basis of differences between voltages V 1 , V 2 , V 5 stored in the storage portion at the change points C 1 , C 2 , C 3 and the voltages V 26 , V 27 , V 28 when the valve is opened. In this way, the fuel supply device can correctly control the motor in correspondence to the fuel pressure and the flow rate which are required by the engine.

First claim

The invention claimed is:

1. A fuel supply device for supplying an engine with fuel sucked up from a fuel tank, the fuel supply device comprising:
a fuel pump for sucking up the fuel from the fuel tank by rotation of a motor;
a valve that is provided in a fuel passage for supplying the engine with the fuel sucked up by the fuel pump and that is opened when the fuel flowing in the fuel passage reaches a specified pressure to thereby discharge the fuel from the fuel passage;
a storage portion for storing a relationship among a fuel pressure, a flow rate, which are required by the engine, and voltage and current which are supplied to the motor;
a controller configured to supply the motor with the voltage and the current based on the relationship stored in the storage portion;
a sensing portion for sensing the voltage and current, which is supplied to the motor by the controller when the valve is opened at a change point wherein a characteristic of the current and the voltage, which are supplied to the motor, is changed at a specified flow rate required by the engine;
a calculation portion for calculating a difference between the voltage and the current which are stored in the storage portion in correspondence to a valve opening voltage, and the voltage and the current which are sensed by the sensing portion when the valve is opened; and
a correction portion for correcting the voltage and the current, which are stored in the storage portion, on the basis of the differences calculated by the calculation portion.

2. A fuel supply device as claimed in claim 1 , further comprising:
an orifice for regulating a flow rate of the fuel discharged from the valve,
wherein the sensing portion senses the voltage and the current, which is supplied to the motor by the controller when the orifice starts to regulate the flow rate at a second change point wherein the characteristic of the current and the voltage, which are supplied to the motor is changed, at the current and the voltage, which is higher than those at the change point,
wherein the calculation portion calculates a difference between the voltage and the current, which are stored in the storage portion in correspondence to a fuel pressure corresponding to a flow rate regulation of the orifice, and the voltage and the current when the valve is opened at the second change point which are sensed by the sensing portion, and
wherein the correction portion linearly corrects the voltage and the current, which are stored in the storage portion, on the basis of the differences at the change point and the differences at the second change point which are calculated by the calculation portion.

3. A fuel supply device as claimed in claim 1 , further comprising:
a second valve that is provided in the fuel passage and that is opened at a fuel pressure different from the valve to thereby discharge the fuel from the fuel passage;
wherein the sensing portion senses the voltage and the current, which is supplied to the motor by the controller when the second valve is opened at a third change point wherein a characteristic of the current and the voltage, which are supplied to the motor, is changed, at current and voltage, which are different from the change point or a second change point,
wherein the calculation portion calculates a difference between the voltage and the current, which are stored in the storage portion in correspondence to a valve opening pressure of the second valve, and the voltage and the current when the second valve is opened at the third change point which is sensed by the sensing portion, and
wherein the correction portion linearly corrects the voltage and the current, which are stored in the storage portion, on the basis of the differences at the change point and the differences at the third change point which are calculated by the calculation portion.

4. A fuel supply device as claimed in claim 1 ,
wherein the sensing portion does not use the current supplied to the motor from the controller so as to sense the change point for a period of time in which an inrush current is developed after the controller starts to supply the motor with electricity.

5. A fuel supply device as claimed in claim 1 ,
wherein the sensing portion, the calculation portion, and the correction portion perform their processings when the engine is started, when a flow rate of the fuel required by the engine is constant at a value of 0 or is constant at a value other than 0, or after a specified time passes after the engine is stopped.

6. A fuel supply device as claimed in claim 5 ,
wherein the controller changes a relationship among the voltage and the current supplied to the motor and time according to a condition of the engine, thereby regulating time necessary for the sensing portion, the calculation portion, and the correction portion to perform their processings.

7. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes the voltage supplied to the motor at a specified rate for a specified time, the sensing portion calculates a differential coefficient of the current with respect to the time and senses the change point by the use of the differential coefficient.

8. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes the voltage supplied to the motor at a specified rate for a specified time, the sensing portion calculates a differential coefficient of a number of revolutions of the motor with respect to the time and senses the change point by the use of the differential coefficient.

9. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes the current supplied to the motor at a specified rate for a specified time, the sensing portion calculates a differential coefficient of a number of revolutions of the motor with respect to the time and senses the change point by the use of the differential coefficient.

10. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes a number of revolutions of the motor at a specified rate for a specified time, the sensing portion calculates a differential coefficient of the voltage or the current with respect to the time and senses the change point by the use of the differential coefficient.

11. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes the voltage and the current, which are supplied to the motor, at a specified rate for a specified time, the sensing portion calculates a second order differential coefficient acquired by further differentiating a differential coefficient of the voltage or the current with respect to the time and senses the change point by the use of the second order differential coefficient.

12. A fuel supply device as claimed in claim 11 ,
wherein when the second order differential coefficient is larger than a specified fluctuation range with center at a mean value of the second order differential coefficient, the sensing portion senses the change point.

13. A fuel supply device as claimed in claim 1 ,
wherein when the controller changes the voltage and the current, which are supplied to the motor, at a specified rate for a specified time, the sensing portion calculates a differential coefficient of the voltage or the current with respect to the time, and
wherein when the differential coefficient is larger than a specified threshold value, the sensing portion senses the change point.

14. A fuel supply device as claimed in claim 11 ,
wherein when the second order differential coefficient is larger than a second threshold value, the sensing portion senses the change point.

Assignees

• Denso Corp

Inventors

• Mori Hideyuki
• Satake Nobuyuki

Classifications

• F02M37/106

  the pump being installed in a sub-tank · CPC title

• F02D33/003

  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 title

• F02D2250/31

  Control of the fuel pressure · CPC title

• F02M69/00

  Low-pressure fuel-injection apparatus {; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel} · CPC title

• F02D2041/2051

  using voltage control · CPC title