Fuel pump control apparatus of engine
View Patent ↗By driving a fuel pump suitably to an amount of fuel according to an amount of fuel consumed by an engine and by monitoring an actual motor speed of the fuel pump, F/B control is carried out according to a target motor speed and the actual motor speed of the fuel pump. Meanwhile, by learning and storing a duty value comparable to a deviation between the target and actual motor speeds, duty driving of the fuel pump is corrected to suit an engine condition. It thus becomes possible to provide a fuel pump control apparatus of an engine capable of promoting power saving by suppressing a wasteful energy loss including a current consumption and making an internal circuit of an ECU simpler by enhancing fuel supply accuracy.
1. A fuel pump control apparatus of an engine, comprising:
an operation condition detection portion that detects an operation condition of the engine;
a motorized fuel pump furnished with a fuel pressure regulation function;
an injector that supplies the engine with fuel according to a fuel pressure supplied from the motorized fuel pump;
a power generation portion that generates power by manual rotational driving of a crank shaft of the engine; and
a control portion that is activated by a voltage generated by the power generation portion and computes an amount of fuel to be injected and calculates a fuel pump driving duty according to a detected value from the operation condition detection portion,
wherein the control portion includes:
an injector injection amount calculation functioning portion that calculates an amount of injector injection to be supplied to the engine according to the operation condition of the engine;
a fuel consumption amount calculation functioning portion that calculates an amount of fuel the engine is consuming on a basis of the amount of injector injection, a number of cylinders of the engine, and an engine rotation speed of the engine;
a pump driving fuel amount calculation functioning portion that calculates an amount of fuel to drive the motorized fuel pump on a basis of an output of the fuel consumption amount calculation functioning portion;
a target motor speed calculation functioning portion that calculates a target motor speed on a basis of an output of the pump driving fuel amount calculation functioning portion;
a driving duty calculation functioning portion that calculates the fuel pump driving duty indicating time periods during which the motorized fuel pump is driven, on a basis of an output of the target motor speed calculation functioning portion; and
a feedback (F/B) correction value calculation functioning portion that finds a deviation between an actual motor speed detected from the motorized fuel pump and the target motor speed and calculates a F/B correction value of the fuel pump driving duty so that the deviation is eliminated, wherein:
in a case where a state in which the operation condition of the engine is stable for a predetermined time period or longer and the F/B correction value is stable without yielding the deviation between the actual motor speed and the target motor speed for the predetermined time period or longer, the control portion learns the F/B correction value and stores the F/B correction value in a memory region in the control portion, so that when the control portion is activated a next time after the predetermined time period elapses, the control portion starts control by correcting the fuel pump driving duty with the stored, learned F/B correction value in addition to a subsequent F/B correction value calculated when the control portion is activated the next time.
2. The fuel pump control apparatus of an engine according to claim 1 , wherein:
in a case where a state in which the deviation between the target motor speed and the actual motor speed while a fuel pump rotation speed is controlled is equal to or larger than a parameter value pre-set in a memory region of the control portion has continued for a predetermined time period or longer, presence of an abnormality in the fuel pump control apparatus is determined and the abnormality in the fuel pump control apparatus is confirmed and stored in the control portion; and
the F/B correction value of a pump speed is stopped to carry out control thereafter according to the target motor speed calculated in the control portion and learned data stored therein.