EGR system

• US 7,182,075 B2
• Filed: 12/07/2004
• Issued: 02/27/2007
• Est. Priority Date: 12/07/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Shahed, Syed M., Hampson, Gregory J.
• Primary Examiner(s): Cronin; Stephen K.
• Assistant Examiner(s): Castro; Arnold
• Application Number:
  US11/005,983
• Publication Number:
  US 20060117750A1
• Time in Patent Office: 812 Days
• Field of Search: 123/568.11, 12356821-56826, 251/129.11, 606/02
• US Class Current: 123/568.21
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02B 33/32 Engines with pumps other than of reciprocating-piston type with crankcase pumps F02B33/02
• CPC Class Codes: F02B 33/34 with rotary pumps with cell-type pressure exchangers or the like F02B33/42
• CPC Class Codes: F02B 33/38 of Roots type
• CPC Class Codes: F02B 37/00 Engines characterised by provision of pumps driven at least for part of the time by exhaust
• CPC Class Codes: F02B 37/12 Control of the pumps
• CPC Class Codes: F02B 39/04 Mechanical drives; Variable-gear-ratio drives non-mechanical pump drives having variable gear ratio F02B39/08
• CPC Class Codes: F02D 41/0065 Specific aspects of external EGR control constructional details of EGR system F02M26/00
• CPC Class Codes: F02D 41/0077 Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position EGR valve position sensor F02M26/48
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/40 with timing means in the recirculation passage, e.g. cyclically operating valves or regenerators; with arrangements involving pressure pulsations
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: F02M 26/54 Rotary actuators, e.g. step motors
• CPC Class Codes: F02M 26/70 Flap valves; Rotary valves; Sliding valves; Resilient valves
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A flow control mechanism connected to the intake and exhaust systems of an engine. The mechanism may achieve recirculation of exhaust gases despite varying differential pressures or delta pressures between the systems, particularly since intake pressures may often exceed exhaust pressures. Pressure sensors may be situated proximate to the input and output of the flow control mechanism. There may a flow sensor proximate to the flow control mechanism. Cylinder pressure or pulse sensors may be situated in or about the engine. A processor may be connected to various sensors and provide prompt active control of a valve or like device in the flow control mechanism. Such valve may operate sufficiently quickly so as to prevent backflow from the intake system into the exhaust system upon sudden pressure changes in the systems. The quickness of the active valve control may also permit recirculating stipulated amounts of exhaust gas to each cylinder.

Claims

1. A recirculation system for an internal combustion engine comprising:

an actuatable valve;

a first tube connected to the valve and to an exhaust mechanism of the internal combustion engine;

a second tube connected to the valve and to an intake mechanism of the engine;

a first pressure sensor situated in the first tube and connected to the valve, the first pressure sensor configured to sense pulses in exhaust pressure;

a second pressure sensor situated in the second tube and connected to the valve; and

a controller, the controller configured to control a flow area, time of opening and time of closing of the valve.

2. The system of claim 1, wherein:

if the pressure sensed by the first sensor exceeds the pressure sensed by the second sensor, then the valve is at least partially open; and

if the pressure sensed by the first sensor is less than the pressure sensed by the second sensor, then the valve is closed.

3. The system of claim 1, wherein:

the valve comprises a first disk and a second disk;

the first disk has at least one slot;

the second disk has at least one slot;

the first disk and the second disk are rotatable relative to each other; and

the first disk and second disk may be rotated relative to each other to provide an at least partial opening of the valve or to provide a closure of the valve.

4. A recirculation system comprising:

an electrically actuated valve having an adjustable window with a flow area, a time of opening, and a time of closing;

a first tube connected to the valve;

a second tube connected to the valve;

a first pressure sensor situated in the first tube;

a second pressure sensor situated in the second tube; and

a controller connected to the valve, the first sensor and the second sensor, the controller configured to open the valve window only when a first pressure sensed by the first pressure sensor exceeds a second pressure sensed by the second pressure sensor.

5. The system of claim 4, wherein:

the first tube is connected to an exhaust mechanism of an internal combustion engine; and

the second tube is connected to an intake mechanism of the engine.

6. The system of claim 5, wherein:

if the pressure sensed by the first sensor exceeds the pressure sensed by the second sensor, then the valve becomes at least partially open; and

if the pressure sensed by the first sensor is less than the pressure sensed by the second sensor, then the valve becomes closed.

7. The system of claim 5, wherein the first pressure sensor is configured to sense the strength of an exhaust pressure pulse, and the controller is configured to adjust the flow area of the valve window according to the strength of the pulse.

8. The system of claim 4,

the first tube connects the valve to an exhaust mechanism of an internal combustion engine;

the second tube connects the valve to an intake mechanism of the engine; and

the valve comprises a first disk and a second disk;

the first disk has at least one slot;

the second disk has at least one slot;

the first disk and the second disk are rotatable relative to each other; and

the first disk and second disk may be rotated relative to each other to provide an at least partial opening of the valve window or to provide a closure of the valve window.

9. A recirculation system for an internal combustion engine comprising:

a valve;

a first tube connected to the valve and to an exhaust mechanism of the engine;

a second tube connected to the valve and to an intake mechanism of the engine;

a mechanism, connected to the valve, for sensing pressure pulses in the first tube; and

a controller connected to the valve and to the mechanism, the controller configured to adjust an opening time and a closing time of the valve for each pressure pulse.