Turbocharger and EGR system

• US 6,263,672 B1
• Filed: 05/17/2000
• Issued: 07/24/2001
• Est. Priority Date: 01/15/1999
• Status: Expired due to Term

• Current Assignee: BorgWarner Incorporated
• Original Assignee: BorgWarner Incorporated
• Inventors: Roby, Stephen I., McKinley, Steven R.
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US09/572,609
• Time in Patent Office: 433 Days
• Field of Search: 606/02, 606/052, 603/24, 123/568.11, 123/568.21, 123/323
• US Class Current: 60/605.2
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• CPC Class Codes: F02B 37/22 by varying cross-section of exhaust passages or air passages , e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits F02B37/24 takes precedence
• CPC Class Codes: F02B 39/14 Lubrication of pumps; Safety measures therefor
• CPC Class Codes: F02D 2250/34 Control of exhaust back pressure, e.g. for turbocharged engines
• CPC Class Codes: F02D 41/0065 Specific aspects of external EGR control constructional details of EGR system F02M26/00
• CPC Class Codes: F02D 9/04 concerning exhaust conduits throttle valves, or arrangements thereof in conduits F02D9/08
• 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 26/09 Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
• CPC Class Codes: F02M 26/10 having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system
• CPC Class Codes: F02M 26/16 with EGR valves located at or near the connection to the exhaust system
• CPC Class Codes: F02M 26/51 EGR valves combined with other devices, e.g. with intake valves or compressors combined with intake air throttles F02M26/64
• CPC Class Codes: F02M 26/67 Pintles; Spindles; Springs; Bearings; Sealings; Connections to actuators
• CPC Class Codes: F02M 26/70 Flap valves; Rotary valves; Sliding valves; Resilient valves
• CPC Class Codes: F02M 26/71 Multi-way valves
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust gas recirculation system for an internal combustion engine. The present invention includes a turbocharger, restrictor valve, and exhaust gas recirculation valve. The restrictor valve is upstream of the turbine of the turbocharger, and restricts the flow of exhaust gas into the turbine. This restriction results in an increase in pressure of the exhaust gas provided to the restrictor valve. The increased pressure exhaust gas is provided to the inlet of an exhaust gas recirculation valve which may be actuatable independently of the actuation of the restrictor valve. The restrictor valve may be modulated until exhaust pressure is greater than the pressure of the intake gas. The restrictor valve creates a pressure differential suitable for recirculating a portion of exhaust gas through the EGR valve and into the intake manifold of the engine. The restrictor valve may also be operated without recirculation of exhaust gas, such as during cold starting of a diesel engine so as to increase the load on the engine and decrease the warm-up time of the engine. Some embodiments of the present invention utilize an electronic controller for operating the restrictor valve and the EGR valve.

Claims

1. A method for recirculating a predetermined flow of exhaust gas into the intake manifold of a turbocharged engine, comprising:

providing an internal combustion engine, a turbocharger for receiving exhaust gas from the engine at a first pressure and providing intake gas to the engine at a second pressure, a restrictor valve for adjusting the first pressure and an exhaust gas recirculation valve for recirculation of exhaust gas into the intake gas;

alternately adjusting the restrictor valve and the exhaust gas recirculation valve to achieve one or more of a predetermined exhaust gas recirculation flow and a predetermined relationship between the first pressure and the second pressure.

2. An exhaust gas recirculation system for an internal combustion engine producing exhaust gas and accepting intake gas comprising:

a turbocharger for increasing the pressure of the intake gas to the engine, said turbocharger having a turbine;

a restrictor valve with an inlet accepting the exhaust gas from the engine, a first outlet in fluid communication with the turbine, a second outlet in fluid communication with the intake manifold;

said restrictor valve adjustable to increase the pressure of the exhaust gas and to divert exhaust gas selectively between the said first outlet and said second outlet; and

said restrictor valve includes a rotatable barrel-shaped semi-cylindrical valve plug having a first, second, and third position, and intermediate positions throughout,

the first position substantially restricting fluid communication from the inlet to the first outlet and substantially restricting fluid communication from the inlet to the first outlet, the second position permitting unobstructed fluid communication from the inlet to the first outlet and substantially restricting fluid communication from the inlet to the second outlet, and the third position substantially restricting fluid communication from the inlet to the first outlet and permitting unobstructed fluid communication from the inlet to the second outlet.

3. The apparatus of claim 2, wherein one support housing assembly supports said turbine and said restrictor valve.

4. A system comprising:

an internal combustion engine producing exhaust gas and accepting intake gas, the exhaust gas being at a first pressure and the intake gas being at a second pressure, said engine having an intake manifold;

a restrictor valve receiving exhaust gas from said engine, said restrictor valve having an actuatable flow restricting device for varying the first pressure, said restrictor valve having a first outlet;

a turbocharger with a turbine with a first inlet, the first inlet being in fluid communication with the first outlet of said restrictor valve;

said turbocharger having a compressor with a first outlet in fluid communication with said intake manifold;

an exhaust gas recirculation valve having a second inlet accepting the exhaust gas and a second outlet in fluid communication with said intake manifold and is actuatable between an opened position in which the second inlet and second outlet are in fluid communication and a closed position in which the second outlet is substantially sealed from the second inlet;

a first sensor for providing a first signal corresponding to the first pressure;

a second sensor for providing a second signal corresponding to the second pressure; and

a controller responsive to said first signal and said second signal, said controller operable to independently adjust said flow restricting device and said exhaust gas recirculation valve to vary the first pressure and to achieve a predetermined relationship between the first pressure and the second pressure.

5. The system of claim 4 wherein said controller includes a digital processor.

6. The system of claim 4 wherein said controller includes a means for detecting one or more specific engine operating conditions;

and

said controller opens said exhaust gas recirculation valve when the first pressure is greater than the second pressure and when said specific engine operating conditions is detected.

7. The system of claim 6 wherein said specific engine operating condition is warm engine.

8. The system of claim 6 wherein said specific engine operating condition is peak torque.

9. An exhaust gas recirculation system for an internal combustion engine producing exhaust gas and accepting intake gas comprising:

a turbocharger for increasing the pressure of the intake gas to the engine said turbochager having a turbine and a support housing;

a restrictor valve for accepting the exhaust gas from the engine and adjustable to increase the pressure of the exhaust gas, said restrictor valve having an outlet in fluid communication with the turbine; and

an exhaust gas recirculation valve with an inlet and an outlet and a valve member selectively movable between opened and closed position, the inlet being in fluid communication with the exhaust gas, the outlet being in fluid communication with the intake of the engine, the inlet being in fluid communication with the outlet in the opened position, and the inlet being substantially sealed from the outlet in the closed position;

wherein said restrictor valve and said exhaust gas recirculation valve are independently adjustable; and

, said turbine, said restrictor valve, and said exhaust gas recirculation valve are commonly supported within said support housing.

10. The apparatus of claim 9, wherein said exhaust gas recirculation valve includes a poppet valve.

11. The apparatus of claim 9, wherein said exhaust gas recirculation valve includes a wastegate valve.

12. The apparatus of claim 9, wherein said restrictor valve includes a variable geometry turbine inlet.

13. The apparatus of claim 9, wherein said restrictor valve includes a butterfly valve.

14. An exhaust gas recirculation system for an internal combustion engine producing exhaust gas and accepting intake gas comprising:

a turbocharger for increasing the pressure of the intake gas to the engine, said turbocharger having a turbine;

a restrictor valve for accepting the exhaust gas from the engine and adjustable to increase the pressure of the exhaust gas, said restrictor valve having an outlet in fluid communication with the turbine;

an exhaust gas recirculation valve with an inlet and an outlet and a valve member selectively movable between opened and closed position, the inlet being in fluid communication with the exhaust gas, the outlet being in fluid communication with the intake of the engine, the inlet being in fluid communication with the outlet in the opened position, and the outlet being substantially sealed from the inlet in the closed position;

a linkage mechanism coupled to said restrictor valve and slidably coupled to said exhaust gas recirculation valve, said linkage mechanism having a first range of motion adjusting only said restrictor valve and having a second range of motion adjusting both said restrictor valve and said exhaust gas recirculation valve.

15. The apparatus of claim 14 wherein said linkage mechanism includes:

a pivotal lever arm operable to adjust said restrictor valve;

a rocker arm operable to adjust said exhaust gas recirculation valve;

a first linkage coupled to said pivotal lever arm;

a second linkage having a first end and a second end, said first end slidably coupled to said pivotal lever arm; and

said second end of said second linkage coupled to said rocker arm.

16. The apparatus of claim 14 wherein said exhaust gas recirculation valve includes a poppet valve.

17. The apparatus of claim 14 wherein said exhaust gas recirculation valve includes a wastegate valve.

18. The apparatus of claim 14 wherein said restrictor valve includes a variable geometry turbine inlet.

19. The apparatus of claim 14 wherein said restrictor valve includes a butterfly valve.

20. The apparatus of claim 14 wherein said turbocharger includes a support housing and said turbine, said restrictor valve, and said exhaust gas recirculation valve are commonly supported within said support housing.

21. A system comprising:

an internal combustion engine producing exhaust gas and accepting intake gas, the exhaust gas having a first pressure, and the intake gas having a second pressure, said engine having an intake manifold;

a turbocharger with a turbine with a first inlet;

said turbocharger having a compressor with a first outlet in fluid communication with said intake manifold,

a restrictor valve with a second inlet accepting the exhaust gas from the engine, a second outlet in fluid communication with the turbine first inlet, a third outlet in fluid communication with the intake manifold;

a first sensor for providing a first signal corresponding to the first pressure;

a second sensor for providing a second signal corresponding to the second pressure;

a controller responsive to said first signal and said second signal, said controller operable to adjust said restrictor valve to vary the first pressure and to achieve a predetermined relationship between the first pressure and the second pressure.

22. The system of claim 21 wherein said controller includes a means for detecting one or more specific engine operating conditions;

and

said controller is operable to adjust restrictor valve to substantially restrict fluid communication from the second inlet to the third outlet when the second pressure is greater than the first pressure and when said specific engine operating conditions is detected.

23. The system of claim 22 wherein said specific engine operating condition is warm engine.

24. The system of claim 22 wherein said specific engine operating condition is peak torque.