Turbocharger and EGR system

• US 6,089,019 A
• Filed: 01/15/1999
• Issued: 07/18/2000
• 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:
  US09/232,361
• Time in Patent Office: 550 Days
• Field of Search: 123/568.11, 123/568.21, 123/323, 60/602, 60/605.2, 60/324
• 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. 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; and

an exhaust gas recirculation valve with an inlet for receiving exhaust gas from the engine and settable for providing exhaust gas to the intake gas of the engine;

wherein said restrictor valve is adjustable independently of the setting of said exhaust gas recirculation valve.

2. The apparatus of claim 1 wherein said restrictor valve includes movable turbine inlet vanes.

3. The apparatus of claim 1 wherein said restrictor valve includes a butterfly valve.

4. The apparatus of claim 1 wherein said restrictor valve includes a barrel valve.

5. An apparatus comprising:

a turbocharger with a turbine and an inlet passage, the inlet passage having a first flow resistance;

a restrictor valve located proximate to the inlet passage, said restrictor valve having a variable flow resistance selectively variable between a maximum and a minimum, the maximum flow resistance being greater than the first flow resistance, said restrictor valve having a first inlet and a first outlet, the first outlet being in fluid communication with the turbine; and

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

wherein said restrictor valve is selectively variable independently of the movement of said valve member of said exhaust gas recirculation valve.

6. The apparatus of claim 5 wherein said restrictor valve includes variable turbine inlet vanes.

7. The apparatus of claim 5 wherein said restrictor valve includes a butterfly valve.

8. The apparatus of claim 5 wherein said restrictor valve includes a barrel valve.

9. An apparatus comprising:

an internal combustion engine accepting intake gas and producing exhaust gas;

a restrictor valve with an inlet for accepting exhaust gas from an internal combustion engine, a first outlet, a second outlet, and a flow restricting device movable between first and second positions, in which the first position substantially restricts fluid communication from the inlet to the first outlet and from the inlet to the second outlet, and the second position substantially restricts fluid communication from the inlet to the first outlet; and

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

wherein exhaust gas from the second outlet is mixed with intake gas.

10. The apparatus of claim 9 which further comprises an exhaust gas recirculation valve for receiving exhaust gas from the second outlet and providing the exhaust gas for mixing with the intake gas.

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

12. 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 a variable flow resistance and an actuatable flow restricting device for varying the flow resistance of said restrictor valve, 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;

an exhaust gas recirculation valve having a second inlet accepting the exhaust gas and a second outlet in fluid communication with said 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; and

a controller responsive to said first signal and said second signal, said controller actuating said flow restricting device to increase the first pressure so that the first pressure is greater than the second pressure.

13. The system of claim 12 wherein said exhaust gas recirculation valve 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, and said controller opens said exhaust gas recirculation valve when the first pressure is greater than the second pressure.

14. The system of claim 12 wherein said controller includes a digital processor.

15. A turbocharger for an internal combustion engine producing exhaust gas, comprising:

a turbine with a first inlet;

a compressor with a first outlet;

a restrictor valve for restricting the flow of exhaust gas into the first inlet of said turbine;

a poppet valve with a second inlet and a second outlet, the second inlet being in fluid communication with the first inlet of said turbine, the second outlet being in fluid communication with the first outlet of said compressor, said poppet valve having an opened position in which the second outlet is in fluid communication with the second inlet and a closed position in which the second outlet is substantially sealed from the second inlet; and

a support housing assembly which supports said turbine, said compressor, said restrictor valve, and said poppet valve.

16. 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, and an exhaust gas recirculation valve;

adjusting the restrictor valve to increase the first exhaust pressure provided to the turbocharger until the first exhaust pressure is greater than the second intake pressure;

opening an exhaust gas recirculation valve to permit recirculation of exhaust gas into the intake gas; and

readjusting the restrictor valve to achieve the predetermined exhaust gas flow.