Patent ID: 8997467
Filing Date: 2015-04-07
Classification: F01N

Abstract:
1. A machine, comprising: an engine having a coolant system, an electrical system having a power storage device, and an exhaust system associated therewith; a diesel exhaust fluid (DEF) injector disposed to provide metered amounts of DEF into the exhaust system; the DEF injector including a housing that forms a coolant passage therethrough, said coolant passage adapted to accommodate a flow of coolant therethrough for cooling the DEF injector; a DEF pump arranged to provide DEF to the DEF injector from a reservoir during operation of the engine; a power management module that includes a controller associated with the electrical system, the DEF injector and the DEF pump; an auxiliary power unit that includes a battery array, is separate from the power storage device of the electrical system, and is associated with the controller, said auxiliary power unit being configured to remain active after the engine electrical system has been deactivated; a temperature sensor disposed to measure a temperature associated with a temperature of the DEF injector and provide a temperature signal indicative of said temperature to the controller of the power management module, an electrically operated coolant pump associated with the power management module and responsive to commands from the controller, said coolant pump being powered by the auxiliary power unit following engine shut-down and operating to route an auxiliary flow of coolant through the coolant passage of the housing, the auxiliary flow of coolant being routed to the housing separately from the coolant system of the engine, wherein the controller is programmed to cause a purge of the DEF from the DEF injector when the engine is shut down, and wherein the power management module is further configured to activate said coolant pump using power provided by the auxiliary power unit when the temperature signal is indicative of a condition in which the temperature of the DEF injector exceeds or is estimated to exceed a threshold temperature after the engine electrical system is shut down.