Method of recuperating energy from a motor vehicle

Patent metadata

Field	Value
Publication number	US-9458790-B2
Application number	US-201414162659-A
Country	US
Kind code	B2
Filing date	Jan 23, 2014
Priority date	Feb 14, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A system and method for recuperating energy from a motor vehicle is described in which during an engine overrun period kinetic energy from the slowing motor vehicle is used to drive a high pressure fuel pump at a high demand level so as to store fuel at high pressure in a fuel accumulator for later use by an engine of the motor vehicle.

First claim

The invention claimed is:

1. A method of recuperating energy from a motor vehicle, comprising:
during a vehicle over-run event wherein substantially no fuel is supplied to an engine, operating a high pressure fuel pump at a high demand level to store fuel in an accumulator, the high pressure fuel pump being engine driven and operable at least at high and low demand levels, and the accumulator being selectively connectable to the high pressure fuel pump and the engine, and
during the vehicle over-run event, operating the high pressure fuel pump at the high demand level if a speed of the motor vehicle is above a predefined minimum vehicle speed and operating the high pressure fuel pump at the low demand level if the speed of the motor vehicle is below the predefined minimum vehicle speed.

2. The method of claim 1 , wherein the high demand level is a maximum demand level of the high pressure fuel pump, the maximum demand level selected to deliver a maximum flow of fuel from the high pressure fuel pump based on an engine speed.

3. The method of claim 1 , further comprising supplying fuel from the accumulator to the engine during a subsequent engine fuel demand event and operating the high pressure fuel pump at the low demand level during a period in which fuel is supplied from the accumulator to the engine.

4. The method of claim 3 , wherein the subsequent engine fuel demand event is an event in which fuel is used by the engine to accelerate the motor vehicle.

5. The method of claim 1 , wherein the low demand level is a minimum demand level of the high pressure fuel pump.

6. The method of claim 1 , further comprising, during the vehicle over-run event, reducing a demand level for the high pressure fuel pump from the high demand level to the low demand level if the accumulator is full.

7. A motor vehicle with a fuel supply system, comprising:
an engine;
a fuel reservoir;
a low pressure fuel pump to supply fuel from the reservoir to an engine driven variable output high pressure fuel pump operable at least at high and low demand levels;
at least one fuel injector to supply fuel at high pressure to the engine;
a fuel accumulator to store fuel at high pressure;
a valve means to control a flow of fuel between the high pressure fuel pump, the accumulator, and the engine; and
an electronic controller to control an operation of the high pressure fuel pump, the valve means and the at least one fuel injector, wherein the electronic controller is operable during a vehicle over-run event in which substantially no fuel is supplied to the engine, to operate the high pressure fuel pump at the high demand level while controlling the valve means to supply fuel from the high pressure fuel pump to the fuel accumulator,
wherein, during the vehicle over-run event, the electronic controller operates the high pressure fuel pump at the high demand level if a speed of the motor vehicle is above a predefined minimum vehicle speed, and operates the high pressure fuel pump at the low demand level if the speed of the motor vehicle is below the predefined minimum vehicle speed.

8. The fuel supply system of claim 7 , wherein the high demand level is a maximum demand level of the high pressure fuel pump, the maximum demand level selected to deliver a maximum flow of fuel from the high pressure fuel pump based on an engine speed.

9. The fuel supply system of claim 7 , wherein, during a subsequent engine fuel demand event, the valve means is controlled by the electronic controller to supply fuel from the accumulator to the engine, and the high pressure fuel pump is operated by the electronic controller at the low demand level during a period in which fuel is being supplied from the accumulator to the engine.

10. The fuel supply system of claim 9 , wherein the subsequent engine fuel demand event is an event in which fuel is used by the engine to accelerate the motor vehicle.

11. The fuel supply system of claim 7 , wherein the low demand level is a minimum demand level of the high pressure fuel pump.

12. The fuel supply system of claim 7 , wherein, during the vehicle over-run event, the electronic controller is further operable to reduce the demand level for the high pressure fuel pump from the high demand level to the low demand level if the accumulator is full.

13. The fuel supply system of claim 7 , wherein the accumulator comprises a body defining a flow passage by which fuel can enter or leave a storage volume defined by a cup shaped piston, a metal bellows and the body, wherein the piston supports the bellows and is slidingly supported by the body, and wherein a spring biases the piston towards an end of the body at which fuel enters or leaves the storage volume via the flow passage, the bellows being sealed to both the body and the piston.

14. A motor vehicle with an engine, comprising:
at least one electrical traction motor to assist with driving of the motor vehicle; and
an electrical generator to recuperate energy from the motor vehicle while storing the energy for subsequent use by the at least one electrical traction motor, wherein
when a speed of the motor vehicle is above a predefined minimum vehicle speed, a fuel supply system is used during a vehicle over-run event to recuperate energy from the motor vehicle by operating a high pressure fuel pump at a high demand level to store fuel in an accumulator while the electrical generator is simultaneously used to recuperate energy from the motor vehicle; and
when the speed of the motor vehicle is below the predefined minimum vehicle speed, the high pressure fuel pump operates at a low demand level during the over-run event while the electrical generator is used to recuperate energy from the motor vehicle and store the recuperated energy as electrical energy.

15. The motor vehicle of claim 14 , wherein the electrical traction motor and the electrical generator are provided by a single electrical machine.

16. The motor vehicle of claim 14 , wherein the high demand level is a maximum demand level of the high pressure fuel pump, and wherein the maximum demand level is selected to deliver a maximum flow of fuel from the high pressure fuel pump based on an engine speed.

17. The motor vehicle of claim 14 , wherein, during a subsequent engine fuel demand event that is used to accelerate the motor vehicle, a valve means is controlled by an electronic controller to supply fuel from the accumulator to the engine, and the high pressure fuel pump is operated by the electronic controller at the low demand level during a period in which fuel is being supplied from the accumulator to the engine.

18. The motor vehicle of claim 14 , wherein an electronic controller is operable to reduce a demand level for the high pressure fuel pump from the high demand level to the low demand level if the accumulator is full during the vehicle over-run event.

Assignees

• Ford Global Tech Llc

Inventors

• Kees Donatus Andreas Josephine
• Lane Stuart Alexander

Classifications

• F02D41/3082 Primary

  Control of electrical fuel pumps · CPC title

• F02M63/0225

  Fuel-injection apparatus having a common rail feeding several injectors (F02M63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails · CPC title

• Y10S903/905

  Combustion engine · CPC title

• F02D41/3845

  by controlling the flow into the common rail, e.g. the amount of fuel pumped · CPC title

• F02D41/123 Primary

  the fuel injection being cut-off · CPC title