Fuel supply device of an internal combustion engine

• US 20050161024A1
• Filed: 01/21/2005
• Published: 07/28/2005
• Est. Priority Date: 01/22/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Wang, Xiumei
• Granted Patent: US 7,017,554 B2
• Time in Patent Office: Days
• US Class Current: 123/456
• 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 41/08 for idling F02D41/06, F02D41/16 take precedence
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• CPC Class Codes: F02M 2200/03 Fuel-injection apparatus having means for reducing or avoiding stress, e.g. the stress caused by mechanical force, by fluid pressure or by temperature variations
• CPC Class Codes: F02M 37/0047 Layout or arrangement of systems for feeding fuel fuel injection apparatus characterised by their conduits and venting means F02M55/00; fuel injection apparatus having a common rail F02M63/0225; arrangement of fuel conduits of low pressure fuel injection apparatus F02M69/462
• CPC Class Codes: F02M 59/04 characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps with rotary valve F02M59/362
• CPC Class Codes: F02M 59/102 Mechanical drive, e.g. tappets or cams F02M45/063 takes precedence
• CPC Class Codes: F02M 59/366 Valves being actuated electrically
• CPC Class Codes: F02M 63/0225 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 Class Codes: F02M 63/028 Returnless common rail system

Abstract

A fuel supply device includes a fuel pump, a plurality of valves, and a controller. The fuel pump includes a plurality of pressure chambers each having a volume that is expanded and contracted by the engine. The plurality of valves open and close the pressure chambers. An expansion time and a contraction time of the pressure chambers are each different. The fuel pump is operable to sealingly store fuel in the pressure chambers by closing the valves. The controller sets closing times for the valves in accordance with a required quantity of fuel to be force fed. The controller switches between a normal control in which all of the pressure chambers sequentially force feed fuel and a thinned-out control in which the force fed fuel is thinned out by stopping closing at least one of the valves.

Claims

1. A fuel supply device of an internal combustion engine comprising:

a fuel pump including a plurality of pressure chambers each having a volume that is expanded and contracted by a power of the engine;

a plurality of opening/closing valves corresponding to the plurality of pressure chambers for opening and closing the pressure chambers, wherein an expansion time and a contraction time of a first pressure chamber is different from that of at least a second pressure chamber, the fuel pump being operable to sealingly store fuel in the pressure chambers by closing the opening/closing valves and supply the fuel in the pressure chambers by contracting of the volumes of the pressure chambers; and

a controller for setting closing times of the opening/closing valves in accordance with a required quantity of fuel to be force fed, wherein the controller freely switches between a normal control in which all of the plurality of pressure chambers sequentially force feed fuel and a thinned-out control in which the force fed fuel is thinned out by stopping closing at least one of the opening/closing valves to place the fuel in the respective pressure chamber in a non-pressurized state.

2. The fuel supply device of claim 1, wherein the device is set to perform a first transition control in which the closing time of the opening/closing valve of the pressure chamber for which the force fed fuel has been thinned out is initially delayed to force feed a small quantity of fuel and is then gradually put ahead to increase the quantity of force fed fuel immediately after switching from the thinned-out control to the normal control.

3. The fuel supply device of claim 1, wherein the device is set to perform a second transition control in which the closing time of the opening/closing valve of the pressure chamber for which the force fed fuel is to be thinned out is gradually delayed to gradually reduce the amount of force fed fuel immediately before switching from the normal control to the thinned-out control.

4. The fuel supply device of claim 1, wherein the controller is set to determine a degree of a request of the force fed fuel at a present time and immediately after the present time based on an operating state of the internal combustion engine and to select the thinned-out control in an operating state in which the degree of the request of the force fed fuel is weak.

5. The fuel supply device of claim 1, wherein the normal control and the thinned-out control are switched in accordance with an operating state of the engine.

6. The fuel supply device of claim 1, wherein the control is switched to the thinned-out control when the injection quantity of the engine is equal to or smaller than an injection quantity reference value and the injection-quantity change amount is equal to or smaller than an injection-quantity change amount reference value,

7. The fuel supply device of claim 1, wherein the pressure chambers stopped during the thinned-out control are sequentially changed out of all the pressure chambers.