Controlled engine shutdown for a hybrid electric vehicle
First Claim
1. A system to control an engine shutdown for a hybrid electric vehicle (HEV) comprising at least one control unit operating to:
- control engine torque;
control engine speed;
stop purge flow from a vapor management valve (VMV);
stop exhaust gas recirculation (EGR)flow from an EGR valve;
ramp off fuel injectors;
flush an engine intake manifold of residual fuel once all sources of fuel are halted; and
disable an ignition system.
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0 Petitions
Accused Products
Abstract
A method and system to control engine shutdown for a hybrid electric vehicle (HEV) is provided. Tailpipe emissions are reduced during the many engine shutdowns and subsequent restarts during the course of an HEV drive cycle, and evaporative emissions are reduced during an HEV “soak” (inactive) period. The engine shutdown routine can ramp off fuel injectors, control engine torque (via electronic throttle control), control engine speed, stop spark delivery by disabling the ignition system, stop purge vapor flow by closing a vapor management valve (VMV), stop exhaust gas recirculation (EGR) flow by closing an EGR valve, and flush the intake manifold of residual fuel (vapor and puddles) into the combustion chamber to be combusted chamber to be combusted. The resulting exhaust gas byproducts are then converted in the catalytic converter.
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Citations
16 Claims
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1. A system to control an engine shutdown for a hybrid electric vehicle (HEV) comprising at least one control unit operating to:
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control engine torque;
control engine speed;
stop purge flow from a vapor management valve (VMV);
stop exhaust gas recirculation (EGR)flow from an EGR valve;
ramp off fuel injectors;
flush an engine intake manifold of residual fuel once all sources of fuel are halted; and
disable an ignition system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method to control an engine shutdown for a hybrid electric vehicle (HEV) comprising the steps of:
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ramping off fuel injectors;
controlling engine torque;
controlling engine speed;
disabling an ignition system;
stopping purge flow from a vapor management valve (VMV);
stopping exhaust gas recirculation (EGR) flow from an EGR valve; and
flushing an engine intake manifold of residual fuel after halting all sources of fuel in the fuel injectors, VMV, and EGR valve. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification