Electronic turbocharger control

• US 4,656,834 A
• Filed: 12/24/1985
• Issued: 04/14/1987
• Est. Priority Date: 12/24/1985
• Status: Expired due to Fees

• Current Assignee: The Garrett Corporation
• Original Assignee: The Garrett Corporation
• Inventors: Elpern, David G.
• Primary Examiner(s): Husar, Stephen F.
• Application Number:
  US06/813,114
• Time in Patent Office: 476 Days
• Field of Search: 60/600, 60/601, 60/602, 60/603, 251/66, 251/68
• US Class Current: 60/602
• CPC Class Codes: F02B 37/183 Arrangements of bypass valves or actuators therefor
• CPC Class Codes: F02B 37/186 Arrangements of actuators or linkage for bypass valves
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An electrically responsive turbocharger control for a turbocharged internal combustion engine includes an electrically operated control device selectively energizable to engage and lock in position the actuator for a wastegate control valve. This control device provides a manner of overriding the normal actuating forces acting in the wastegate control valve.

Claims

1. A turbocharger comprising:

a turbine adapted to be rotatably driven by exhaust gas flow from an engine;

a compressor rotatably driven by said turbine and adapted to deliver pressurized airflow to the engine;

housing means for defining a turbine gas inlet and outlet to direct gas flow to and from said turbine, and for defining a compressor air inlet and outlet to direct airflow to and from said compressor, said housing means further defining a wastegate passage interconnecting said turbine gas inlet and outlet in bypassing relation to said turbine;

a valve in said wastegate passage for modulating the volume of gas flow therethrough in bypassing relation to said turbine, said valve arranged such that pressure of gas flow in said turbine gas inlet urge said valve toward an open position;

an actuator operably engaging said valve for moving the latter;

biasing means operably engaging said actuator for urging said valve toward a closed position;

means for generating an electrical control signal in response to an engine operating parameter; and

control means responsive to said electrical control signal for engaging and disengaging said actuator, said control means operable upon engaging said actuator to override the urgings of said biasing means and said turbine inlet pressure and hold said actuator and said valve stationary.

2. A turbocharger as set forth in claim 1 wherein said control means is a solenoid having an armature for engaging and disengaging said actuator.

3. A turbocharger as set forth in claim 1 wherein said signal means comprises means for generating an electrical signal in relation to compressor discharge pressure.

4. A turbocharger comprising:

a turbine adapted to be rotatably driven by exhaust gas flow from an engine;

a compressor rotatably driven by said turbine and adapted to deliver pressurized airflow to the engine;

housing means for defining a turbine gas inlet and outlet to direct gas flow to and from said turbine, and for defining a compressor air inlet and outlet to direct airflow to and from said compressor, said housing means further defining a wastegate passage interconnecting said turbine gas inlet and outlet in bypassing relation to said turbine;

a valve in said wastegate passage for modulating the volume of gas flow therethrough in bypassing relation to said turbine, said valve arranged such that pressure of gas flow in said turbine gas inlet urges said valve toward an open position;

a linearly shiftable actuator rod movably mounted to said housing means and connected to said valve for moving the latter between said open position and a closed position;

a spring extending between said housing means and said actuator rod for urging the latter to move said valve toward said closed position;

an electrically energizable control device having a member movable into locking engagement with said actuator rod upon energization of said control device to hold said rod and said valve in position against the opposing forces of said spring and said pressure of gas flow, said member being released from locking engagement with said rod upon deenergization of said control device to permit said valve to move in response to said opposing forces; and

means for generating an electrical signal to energize said control device.

5. A turbocharger as set forth in claim 4 wherein said control device is a solenoid, and said member is an armature of said solenoid.

6. A turbocharger as set forth in claim 5 wherein said actuator includes a rod having a plurality of grooves, said armature being movable into one of said grooves to lock said actuator rod upon energization of said solenoid.

7. A turbocharger as set forth in claim 5 wherein said actuator rod includes a plurality of grooves, said armature being movable into one of said grooves to lock said actuator rod upon energization of said solenoid.

8. A turbocharger as set forth in claim 5 wherein said actuator rod is configured with a plurality of teeth on the outer surface of a portion of said actuator rod, said armature having an end configured with teeth for mating, locking interengagement with said teeth of the actuator rod.

9. A turbocharger as set forth in claim 5 further including frictional material secured to one end of said armature for frictional, locking engagement with said actuator rod upon energization of said solenoid.

10. A turbocharger as set forth in claim 4 wherein said control device is an electrical stepper motor, and said member is a ratchet wheel driven by said motor, said ratchet wheel having ratchet teeth about the periphery thereof, said actuator rod having a plurality of lands and grooves for lockably receiving one of said ratchet teeth, said stepper motor upon energization effecting locking engagement of said ratchet teeth with said rod.

11. A turbocharger as set forth in claim 4 wherein said signal means comprises means for generating an electrical signal in relation to compressor discharge pressure.

12. In a wastegate controlled turbocharger:

a turbine adapted to be rotatably driven by engine exhaust gas flow;

a housing defining a gas inlet and gas outlet for directing engine exhaust gas flow to and from said turbine, said housing defining a wastegate passage interconnecting said gas inlet and outlet in bypassing relationship to said turbine;

a valve in said wastegate passage movable to modulate flow of exhaust gas through said wastegate passage, said valve arranged to be urged toward an open position by inlet pressure in said gas inlet;

biasing means for urging said valve toward a closed position;

an actuator operably connected to said valve;

signal means for generating an electrical control signal; and

control means responsive to said signal means for engaging said actuator, said control means operable to hold said actuator and said valve relatively stationary upon engaging said actuator.

13. In a turbocharger having an exhaust gas driven turbine, a duct for carrying exhaust gas in bypassing, nondriving relationship to the turbine, and a valve in said wastegate duct for modulating flow of exhaust gas therethrough to control turbine speed:

an actuator operably associated with said valve for moving the latter;

biasing means operably engaging said actuator for urging said valve toward a closed position, said valve arranged such that the pressure of exhaust gas in said wastegate duct urges said valve toward an open position;

signal means for generating an electrical control signal; and

control means responsive to said signal means for engaging said actuator, said control means operable to hold said actuator and said valve relatively stationary upon engaging said actuator.

14. In a turbocharger having an exhaust gas driven turbine, a wastegate duct for carrying exhaust gas in bypassing, nondriving relationship to the turbine, and a valve in said wastegate duct for modulating flow of exhaust gas therethrough to control turbine speed:

an actuator rod connected with said valve for moving the latter;

biasing means operably engaging said actuator rod for urging said valve toward a closed position, said valve arranged such that the pressure of exhaust gas in said wastegate duct urges said valve toward an open position; and

an electrically energizable control brake movable to a position relatively rigidly engaging said actuator rod to prevent movement of said rod and said valve upon energization of said control brake, said control brake upon being deenergized permitting movement of said rod and said valve.

15. A turbocharger as set forth in claim 14 wherein said control brake includes a solenoid having an armature movable into locking engagement with said actuator rod upon energization of said solenoid.

16. A turbocharger as set forth in claim 15 wherein said actuator rod includes a plurality of grooves, said armature being movable into one of said grooves to lock said actuator rod upon energization of said solenoid.

17. A turbocharger as set forth in claim 15 wherein said actuator rod is configured with a plurality of teeth on the outer surface of a portion of said actuator rod, said armature having an end configured with teeth for mating, locking interengagement with said teeth of the actuator rod.

18. A turbocharger as set forth in claim 15 further including frictional material secured to one end of said armature for frictional, locking engagement with said actuator rod upon energization of said solenoid.

19. A turbocharger as set forth in claim 14 wherein said control brake is an electrical stepper motor having a ratchet wheel with ratchet teeth about the periphery thereof, said actuator rod having a plurality of lands and grooves for lockably receiving one of said ratchet teeth, said stepper motor upon energization effecting locking engagement of said ratchet teeth with said rod.

20. A turbocharger as set forth in claim 14, further including signal means for generating an electrical signal to energize said control brake.

21. A turbocharger as set forth in claim 20 wherein said signal means comprises means for generating an electrical signal in relation to compressor discharge pressure.

22. A method for adjusting the speed of a turbine of an exhaust gas driven turbocharger, comprising the steps of:

directing motive exhaust gas flow in parallel relationship to the turbine and to a wastegate duct bypassing the turbine;

modulating exhaust gas flow through the wastegate duct by variably positioning a wastegate valve therein;

utilizing the pressure of exhaust gas flow to urge the wastegate valve toward a fully open position;

spring biasing an actuator attached to the wastegate valve in a direction urging the wastegate valve toward a fully closed position;

generating an electrical control signal responsive to a preselected engine operating parameter; and

energizing and deenergizing a control mechanism in response to said electrical control signal to respectively lock the actuator and wastegate valve against movement by the opposing forces of the exhaust gas pressure and the spring bias, and release the actuator for movement in response to said opposing forces.

23. A method for adjusting the speed of a turbine of an exhaust gas driven turbocharger, comprising the steps of:

directing motive exhaust gas flow in parallel relationship to the turbine and to a wastegate duct bypassing the turbine;

modulating exhaust gas flow through the wastegate duct by variably positioning a wastegate valve therein;

utilizing the pressure of exhaust gas flow to urge the wastegate valve toward a fully open position;

spring biasing an actuator attached to the wastegate valve in a direction urging the wastegate valve toward a fully closed position;

generating an electrical control signal responsive to a preselected engine operating parameter; and

overriding the forces exerted by the exhaust gas pressure and the spring bias and rigidly holding the actuator and wastegate valve against movement in response to said electrical control signal.

24. A method as set forth in claim 23 wherein said overriding step includes energizing a solenoid in response to said electrical signal to drive an armature of the solenoid into locking engagement with the actuator.