Fuel supply system, marine propulsion device and outboard motor

Patent metadata

Field	Value
Publication number	US-9879631-B2
Application number	US-201615378170-A
Country	US
Kind code	B2
Filing date	Dec 14, 2016
Priority date	Dec 15, 2015
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A fuel supply system includes a sub fuel tank, a booster pump, a fuel pipe, a fuel pressure sensor and a controller. The sub fuel tank stores a fuel supplied thereto from a main fuel tank. The booster pump is disposed inside the sub fuel tank. The fuel pipe has a returnless structure and supplies the fuel with a pressure increased by the booster pump to a fuel injection device of an engine. The fuel pressure sensor detects the pressure of the fuel inside the fuel pipe. The controller is configured or programmed to perform a feedback control of the booster pump based on a value of the pressure of the fuel detected by the fuel pressure sensor such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to a first threshold.

First claim

What is claimed is:

1. A fuel supply system comprising;
a sub fuel tank that stores a fuel supplied thereto from a main fuel tank;
a booster pump disposed inside the sub fuel tank;
a fuel pipe with a returnless structure, the fuel pipe supplying the fuel with a pressure increased by the booster pump to a fuel injection device of an engine;
a fuel pressure sensor that detects a pressure of the fuel inside the fuel pipe; and
a controller configured or programmed to perform a feedback control of the booster pump based on a value of the pressure of the fuel detected by the fuel pressure sensor such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to a first threshold.

2. The fuel supply system according to claim 1 , wherein the sub fuel tank is not provided with a return pipe connected thereto.

3. The fuel supply system according to claim 1 , wherein the fuel injection device is not provided with a return pipe connected thereto.

4. The fuel supply system according to claim 1 , wherein all of the fuel to be discharged from the sub fuel tank to the fuel pipe is discharged outside of the fuel pipe from the fuel injection device.

5. The fuel supply system according to claim 1 , wherein the controller is configured or programmed to perform an intermittent operation of the booster pump such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to the first threshold and becomes less than or equal to a second threshold, the second threshold being greater than the first threshold.

6. The fuel supply system according to claim 5 , wherein the controller is configured or programmed to alternately repeat a drive period and a stop period in the intermittent operation, the drive period being set to drive the booster pump by supplying electric power to the booster pump, the stop period being set to stop the booster pump by stopping supplying electric power to the booster pump.

7. The fuel supply system according to claim 6 , wherein the controller is configured or programmed to set the drive period such that the booster pump discharges an amount of the fuel required to be injected by the fuel injection device during the drive period.

8. The fuel supply system according to claim 5 , wherein the controller is configured or programmed to control an injection duration of the fuel injection device based on at least the value of the pressure of the fuel inside the fuel pipe and an amount of the fuel required to be injected by the fuel injection device.

9. The fuel supply system according to claim 8 , wherein the controller is configured or programmed to control the injection duration with reference to a map indicating a relationship at least between the value of the pressure of the fuel inside the fuel pipe and the amount of the fuel required to be injected.

10. The fuel supply system according to claim 5 , wherein the controller is configured or programmed to perform the intermittent operation when an amount of the fuel required to be injected is less than a predetermined threshold.

11. A marine propulsion device configured to be attached to a watercraft hull including a main fuel tank, the marine propulsion device comprising:
an engine including a fuel injection device; and
a fuel supply system that supplies fuel to the engine; wherein
the fuel supply system includes:
a sub fuel tank that stores the fuel supplied thereto from the main fuel tank;
a booster pump disposed inside the sub fuel tank;
a fuel pipe with a returnless structure, the fuel pipe supplying the fuel with a pressure increased by the booster pump to the fuel injection device;
a fuel pressure sensor that detects the pressure of the fuel inside the fuel pipe; and
a controller configured or programmed to perform a feedback control of the booster pump based on a value of the pressure of the fuel detected by the fuel pressure sensor such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to a first threshold.

12. The marine propulsion device according to claim 11 , wherein the booster pump supplies the fuel from the main fuel tank to the sub fuel tank.

13. An outboard motor configured to be attached to a watercraft hull including a main fuel tank, the outboard motor comprising:
an engine including a fuel injection device;
a cowl accommodating the engine; and
a fuel supply system that supplies fuel to the engine; wherein
the fuel supply system includes:
a sub fuel tank that stores the fuel supplied thereto from the main fuel tank;
a booster pump disposed inside the sub fuel tank;
a fuel pipe with a returnless structure, the fuel pipe supplying the fuel with a pressure increased by the booster pump to the fuel injection device;
a fuel pressure sensor that detects the pressure of the fuel inside the fuel pipe; and
a controller configured or programmed to perform a feedback control of the booster pump based on a value of the pressure of the fuel detected by the fuel pressure sensor such that the pressure of the fuel inside the fuel pipe becomes greater than or equal to a first threshold; and

the sub fuel tank is disposed inside the cowl.

Assignees

• Yamaha Motor Co Ltd

Inventors

• Kadobayashi Yoshiyuki

Classifications

• F02M59/38

  Pumps characterised by adaptations to special uses or conditions · CPC title

• F02D41/3082 Primary

  Control of electrical fuel pumps · CPC title

• F02M2200/247

  Pressure sensors · CPC title

• F02M37/0058

  Returnless fuel systems, i.e. the fuel return lines are not entering the fuel tank · CPC title

• F02M37/0088

  Multiple separate fuel tanks or tanks being at least partially partitioned · CPC title