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1. EP2484886 - INTERNAL COMBUSTION ENGINE CONTROL DEVICE

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[ EN ]
Claims

1. An internal combustion engine control apparatus comprising: a throttle valve arranged in an air intake passage of an internal combustion engine; a bypass passage that is communicated with the air intake passage and bypasses the throttle valve; an idle-speed control valve that controls an idle speed of the internal combustion engine by adjusting a flow rate of air flowing in the bypass passage; a stepping motor that drives the idle-speed control valve; and a microcomputer that controls an entire operation of the internal combustion engine, wherein
the device further comprises:

a driving unit that step-drives the stepping motor in response to a control signal input from the microcomputer;

a current detecting unit that detects a current flowing in the stepping motor via the driving unit;

a current-abnormality detecting unit that compares a current value detected by the current detecting unit with a predetermined threshold, and outputs a current abnormality signal when the current value is equal to or less than the predetermined threshold; and

an output-current abnormality-signal holding unit that determines whether the current abnormality signal is being output from the current-abnormality detecting unit continuously for a predetermined time or longer, and outputs a current abnormality signal when the current abnormality signal is being output continuously for a predetermined time or longer, and does not output a current abnormality signal when the current abnormality signal is output continuously for less than the predetermined time, and

the microcomputer stops an output of a control signal to the driving unit in response to an input of the current abnormality signal from the current abnormality-signal holding unit.


  2. The internal combustion engine control apparatus according to claim 1, wherein the predetermined time corresponds to a time during which the control signal input from the microcomputer to the driving unit is at a high level.
  3. The internal combustion engine control apparatus according to claim 1, wherein a time point of starting a measurement of the predetermined time and a time point of inputting the control signal from the microcomputer to the driving unit are substantially a same time point.
  4. The internal combustion engine control apparatus according to claim 1, further comprising a denoising unit that removes noise superimposed on an output signal of the current detecting unit, between the current detecting unit and the current-abnormality detecting unit.
  5. The internal combustion engine control apparatus according to claim 1, wherein at least the current detecting unit, the current-abnormality detecting unit, and the current abnormality-signal holding unit are arranged in a same integrated circuit, and the integrated circuit and the microcomputer are arranged in a same package.