Ignition timing control unit for a car engine and method thereof

Claim 1

An ignition timing control unit for a car engine which comprises an operational control circuit for controlling the output timing of ignition current to be applied to a spark plug in accordance with a crank angle signal produced for every equal crank angle in synchronization with the rotation of a crank shaft; said operational control circuit further comprising; (a) engine speed detecting means for detecting the engine speed in accordance with the crank angle signal, (b) memory means for storing averaged values of the engine speed, (c) basic spark advance angle calculating means for calculating a basic spark advance value from running conditions of the engine, (d) averaging means for newly carrying out an averaging process in accordance with the engine speed and an averaged value of the engine speed and afterward storing the result of the averaging process into said memory means as one averaged value of the engine speed and for updating said average value of the engine speed which has been stored in said memory means, and (e) calculating means for calculating an amount to be corrected of the spark advance angle in accordance with the difference between the averaged out value and the engine speed and for controlling the output timing of the ignition current in accordance with the amount thus corrected of the basic spark advance angle value by said amount to be corrected.

Claim 3

A method for controlling an ignition timing for a car engine by use of a microprocessor having a ROM and a RAM, which comprises the steps of: (a) determining whether or not a crank angle is in the suitable timing for the ignition control in accordance with the signals from the crank sensor and from a cylinder identifying sensor; (b) detecting the current engine speed and storing the data corresponding to the engine speed in a memory, as the result of the first determination; (c) determining whether or not the current engine speed NE detected above is larger than a weighting averaged value NE i-1 which was detected previously and which has been stored in the memory of the microprocessor; (d) updating the old weighting averaged value NE i-1 stored in the memory with a new weighting averaged value NE i by detecting new current engine speed NE as the result of the second determination; (e) calculating the difference ΔNE between said new averaged out value NE i and the current engine speed NE and calculating a delay angle amount Δθ to be corrected for the spark advance angle of a crank angle by the following equation; Δθ=C×ΔNE (where C indicates a constant) (f) calculating an effective spark advance angle value θ by the following equation; θ=θ.sub.base -Δθ after calculating a basic spark advance angle value θ base in accordance with current running conditions of the engine e.g. engine cooling water temperature, engine load; (g) controlling the output timing of ignition current to be applied to a spark plug in accordance with the effective spark advance angle value θ thus calculation.

Claim 4

A method for controlling an ignition timing for a car engine by use of a microprocessor having a ROM and a RAM, which comprises the steps of: (a) determining whether or not a crank angle is in the suitable timing for the ignition control in accordance with the signals from the crank sensor and from a cylinder identifying sensor; (b) detecting the current engine speed and storing the data corresponding to the engine speed in a memory, as the result of the first determination; (c) determining whether or not the current engine speed NE detected above is larger than a weighting averaged value NE i-1 which was detected previously and which has been stored in the memory of the microprocessor; (d) updating the old weighting averaged value NE i-1 stored in the memory with a new weighting averaged value NE i by detecting new current engine speed NE as the result of the second determination; (e) calculating the difference ΔNE between said new averaged out value NE i and the current engine speed NE and calculating a delay angle amount Δθ to be corrected for the spark advance angle of a crank angle by the following equation; Δθ=C×ΔNE (where C indicates a constant) (f) calculating an effective spark advance angle value θ by the following equation; θ=θ.sub.base -Δθ after calculating a basic spark advance angle value θ base in accordance with current running conditions of the engine e.g. engine cooling water temperature, engine load; (g) controlling the output timing of ignition current to be applied to a spark plug in accordance with the effective spark advance angle value θ thus calculation.

Claim 6

A method for controlling an ignition timing for a car engine by use of a microprocessor having a ROM, and a RAM, which comprises the steps of: (a) determining whether or not the crank angle is in a suitable timing for the ignition control in accordance with the signals from the crank angle sensor and from the cylinder identifying sensor; (b) detecting the current engine speed and storing the data corresponding to the engine speed in a memory, as the result of the first determination; (c) updating the old averaged value stored in the memory with a new weighting averaged value NE i by detecting new current engine speed NE, as the result of the second determination; (d) calculating the difference NE i and the current engine speed NE and calculating a delay angle amount Δθ to be corrected for the spark advance angle of the crank angle by the following equation; Δθ=C×ΔNE (where C indicates a constant) (e) calculating an effective spark advance angle value θ by the following equation; θ=θ.sub.base -Δθ after calculating a basic spark advance value θ base in accordance with current running conditions of the engine, e.g. engine cooling water temperature, engine load, etc; and (f) controlling the output timing of, the ignition current to be applied to the spark plug in accordance with the effective spark advance angle value θ thus calculated.

Claim 7

A method for controlling an ignition timing for a car engine by use of a microprocessor having a ROM, and a RAM, which comprises the steps of: (a) determining whether or not the crank angle is in a suitable timing for the ignition control in accordance with the signals from the crank angle sensor and from the cylinder identifying sensor; (b) detecting the current engine speed and storing the data corresponding to the engine speed in a memory, as the result of the first determination; (c) updating the old averaged value stored in the memory with a new weighting averaged value NE i by detecting new current engine speed NE, as the result of the second determination; (d) calculating the difference NE i and the current engine speed NE and calculating a delay angle amount Δθ to be corrected for the spark advance angle of the crank angle by the following equation; Δθ=C×ΔNE (where C indicates a constant) (e) calculating an effective spark advance angle value θ by the following equation; θ=θ.sub.base -Δθ after calculating a basic spark advance value θ base in accordance with current running conditions of the engine, e.g. engine cooling water temperature, engine load, etc; and (f) controlling the output timing of, the ignition current to be applied to the spark plug in accordance with the effective spark advance angle value θ thus calculated.