Internal-combustion engines – Charge forming device – Fuel injection system
Patent
1990-08-27
1992-03-31
Argenbright, Tony M.
Internal-combustion engines
Charge forming device
Fuel injection system
123478, F02P 3045, F02D 4102
Patent
active
050998102
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention relates to a device for producing control signals in timed relation to the rotation of a shaft, especially the crankshaft or camshaft of an internal combustion engine for triggering fuel ignition and/or fuel injection operations.
BACKGROUND OF THE INVENTION
Such a device is known from U.S. Pat. No. 3,943,898. In this known device, the reference mark resets a counter which counts pulses produced by a pulse generator at 1.degree. intervals of rotation of the crankshaft of the internal combustion engine. The control signals are produced by a decoder connected to the output of the counter. The control signals are processed by a computer which produces trigger signals for triggering ignition sparks, the number of control signals being equal to the number of engine cylinders. The computer delays the trigger signals with respect to the control signals in accordance with engine operating parameters (engine speed, air intake pressure, cooling water temperature) in order to obtain the desired optimum ignition timing.
The European patent application EP-A 187,182 describes a "High resolution electronic ignition control loop circuit 22 including a voltage-controlled oscillator (VCO) and a digital phase comparator 24, which receives an input signal from a speed sensor together with a divided output signal from the VCO. A filter 26 lies between the phase comparator and the VCO. The speed is sensed from a wheel having a plurality of teeth. Therefore, the response time of the phase lock loop circuit 22 with its filter 26 does not create any problems, when one turn of the sensed wheel is monitored. However, the known circuitry is too slow in its response time, when reference marks are sensed.
An example of a voltage-controlled oscillator is disclosed in "Handbook of Operational Amplifier Circuit Design": McGraw-Hill, 1976, pages 21-5 to 21-10.
Such a device has the disadvantage that, due to its complexity and the large numbers of input parameters required, it does not lend itself to use as a stand-by or back-up system for carrying on the function of a control apparatus in the event of failure of a microprocessor in the latter.
SUMMARY OF THE INVENTION
The arrangement of the invention overcomes the above disadvantage. In particular, trigger signals for the ignition or injection operations for the individual cylinders of the internal combustion engine can be obtained from a single input signal (reference mark) produced once for each revolution of the crankshaft and in exact timed relationship with the rotation of the crankshaft. The angular movement of the crankshaft is divided into the desired equal sectors to produce control signals at the instant required for the respective signals. A separate pulse generator and associated counter as disclosed in U.S. Pat. No. 3,943,898 are not required. The phase relationship between the output signal and the input signal is fixed. A precise angular relationship between the peaks of the output waveform is possible. The correct frequency and phase relationship are obtained after each change in the frequency of the input signal (shaft speed). The PLL in the device of the present invention is especially suitable for low frequencies. The properties of the PLL are maintained over a very high frequency range, for example, 1 hertz to 250 hertz (60 r.p.m. to 15000 r.p.m.)
GB-A-15 86 013 illustrates the use of a conventional PLL in conjunction with an ignition system but it is used to derive fuel injection trigger pulses from ignition pulses and timing is not critical in the case of petrol injection into the intake manifold.
According to another feature of the invention, in which the control voltage for the VCO is obtained from a frequency determining capacitor and the output of the VCO is fed to an output capacitor, a triangular waveform can be obtained from the latter and the PLL responds rapidly to changes in the engine speed.
It is advantageous, if the time constants pertaining to the two capacitors are matched as any frequency adjustment consequent
REFERENCES:
patent: 3943898 (1976-03-01), Kiencke
patent: 3990417 (1976-11-01), Tershak
patent: 3991727 (1976-11-01), Kawai et al.
patent: 4164926 (1979-08-01), Kindlmann
patent: 4262643 (1981-04-01), Cavil et al.
patent: 4347819 (1982-09-01), Roberts
patent: 4351287 (1982-09-01), Shirasaki et al.
patent: 4467763 (1984-08-01), Gillespie et al.
patent: 4494509 (1985-01-01), Long
patent: 4787354 (1988-11-01), Wilens et al.
"Handbook of Operational Amplifier Circuit Design" by D. F. Stout et al., McGraw Hill Book Company.
Argenbright Tony M.
Ottesen Walter
Robert & Bosch GmbH
LandOfFree
Device for producing control signals in timed relation to the ro does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for producing control signals in timed relation to the ro, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for producing control signals in timed relation to the ro will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2251676