Multi-mode engine-disconnect clutch assemblies and control logic for hybrid electric vehicles
Presented are engine-disconnect clutches with attendant control logic, methods for making/operating such disconnect clutches, and hybrid electric vehicles (HEV) equipped with an engine that is coupled to/decoupled from a transmission and electric motor via a disconnect clutch. A representative method for controlling an HEV powertrain includes receiving an HEV powertrain operation command, then determining a clutch mode of a multi-mode clutch device to execute the HEV powertrain operation. This multi-mode clutch device is operable in: a lock-lock mode, in which the clutch device transmits torque to and from the engine; a free-free mode, in which the clutch device disconnects the engine's output member from the transmission's input member, preventing torque transmission to and from the engine; a lock-free mode, in which the clutch device transmits torque from but not to the engine; and, a free-lock mode, in which the clutch device transmits torque to but not from the engine.
1. A method for controlling operation of a hybrid electric vehicle (HEV) powertrain, the HEV powertrain including an engine with an engine output member, a transmission with a transmission input member, an electric motor with a motor output member selectively connectable to the transmission input member, and a multi-mode clutch device selectively disconnecting the engine output member from the transmission input member, the method comprising:
receiving a command signal indicative of an HEV powertrain operation, the HEV powertrain operation being dependent upon a driver input and a current vehicle operating condition;
determining a current clutch mode of the multi-mode clutch device, the current clutch mode being dependent upon the current vehicle operating condition;
determining a matching clutch mode of the multi-mode clutch device to execute the HEV powertrain operation, the multi-mode clutch device being operable in the following modes:
a lock-lock mode in which the multi-mode clutch device transmits torque to and from the engine,
a free-free mode in which the multi-mode clutch device disconnects the engine output member from the transmission input member and thereby prevents torque transmission to and from the engine,
a lock-free mode in which the multi-mode clutch device transmits torque from and not to the engine, and
a free-lock mode in which the multi-mode clutch device transmits torque to and not from the engine; and
responsive to the current and matching clutch modes being different, transmitting a command signal to the multi-mode clutch device to switch from the current clutch mode to the determined matching clutch mode.
2. The method of claim 1 , wherein the HEV powertrain operation is an engine-only driving operation, and the matching clutch mode is either one of the lock-lock mode and the lock-free mode.
3. The method of claim 1 , wherein the HEV powertrain operation is a motor-only driving operation, and the matching clutch mode is either one of the free-free mode and the lock-free mode.
4. The method of claim 1 , wherein the HEV powertrain operation is a motor-boosting engine-driving operation, and the matching clutch mode is either one of the lock-lock mode and the lock-free mode.
5. The method of claim 1 , wherein the HEV powertrain operation is a key-crank operation, and the matching clutch mode is either one of the lock-lock mode and the lock-free mode.
6. The method of claim 1 , wherein the HEV powertrain operation is a regenerative-braking engine-connected operation, and the matching clutch mode is either one of the lock-lock mode and the free-lock mode.
7. The method of claim 1 , wherein the HEV powertrain operation is a regenerative-braking engine-disconnected operation, and the matching clutch mode is either one of the lock-free mode and the free-free mode.
8. The method of claim 1 , wherein the HEV powertrain operation is a power upshift operation, and the matching clutch mode is the lock-lock mode.
9. The method of claim 1 , wherein the HEV powertrain operation is a power downshift operation, and the matching clutch mode is either one of the lock-lock mode and the lock-free mode.
10. The method of claim 1 , wherein the HEV powertrain operation is a tip-in engine-disconnect operation, and the matching clutch mode is the lock-free mode.
11. The method of claim 1 , wherein the HEV powertrain operation is a tip-in engine-connect operation, and the matching clutch mode is the lock-lock mode.
12. The method of claim 1 , wherein the HEV powertrain operation is a tip-out engine-connect operation, and the matching clutch mode is either one of the lock-lock mode and the free-lock mode.
13. The method of claim 1 , wherein the HEV powertrain operation is a tip-out engine-disconnect operation, and the matching clutch mode is either one of the lock-free mode and the free-free mode.
14. A hybrid electric vehicle (HEV) comprising:
a vehicle body with a plurality of road wheels;
an internal combustion engine (ICE) assembly attached to the vehicle body, the ICE assembly including a crankshaft configured to output torque generated by the ICE assembly;
a motor/generator unit (MGU) attached to the vehicle body and connected in parallel power-flow communication with the ICE assembly, the MGU including a motor output shaft configured to output torque generated by the MGU;
a multi-speed transmission operable to receive, selectively modify, and transmit torque output by the MGU and ICE assembly to one or more of the road wheels;
a multi-mode selectable one-way clutch (SOWC) interposed between the ICE assembly and both the MGU and multi-speed transmission, the multi-mode SOWC being operable in: a lock-lock mode in which the multi-mode SOWC transmits torque to and from the engine; a free-free mode in which the multi-mode SOWC disconnects the engine from the transmission and the MGU to thereby prevent torque transmission to and from the engine; a lock-free mode in which the multi-mode SOWC transmits torque from and not to the engine; and a free-lock mode in which the multi-mode SOWC transmits torque to and not from the engine; and
a vehicle controller communicatively connected to the multi-mode SOWC and programmed to execute memory stored instructions to:
receive a command signal indicative of an HEV powertrain operation;
determine a current clutch mode of the multi-mode SOWC;
determine a matching clutch mode of the multi-mode SOWC to execute the HEV powertrain operation; and
responsive to the current and matching clutch modes being different, transmit a command signal to the multi-mode SOWC to switch from the current clutch mode to the determined matching clutch mode.
15. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
an engine-only driving operation with the matching clutch mode being either one of the lock-lock mode and the lock-free mode; and
a motor-only driving operation with the matching clutch mode being either one of the free-free mode and the lock-free mode.
16. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
a regenerative-braking engine-connected operation with the matching clutch mode being either one of the lock-lock mode and the free-lock mode; and
a regenerative-braking engine-disconnected operation with the matching clutch mode being either one of the lock-free mode and the free-free mode.
17. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
a power upshift operation with the matching clutch mode being the lock-lock mode; and
a power downshift operation with the matching clutch mode being either one of the lock-lock mode and the lock-free mode.
18. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
a tip-in engine-disconnect operation with the matching clutch mode being the lock-free mode; and
a tip-in engine-connect operation with the matching clutch mode being the lock-lock mode.
19. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
a tip-out engine-connect operation with the matching clutch mode being either one of the lock-lock mode and the free-lock mode; and
a tip-out engine-disconnect operation with the matching clutch mode being either one of the lock-free mode and the free-free mode.
20. The hybrid electric vehicle of claim 14 , wherein the HEV powertrain operation is either one of:
a motor-boosting engine-driving operation with the matching clutch mode being either one of the lock-lock mode and the lock-free mode; and
a key-crank operation with the matching clutch mode being either one of the lock-lock mode and the lock-free mode.