Internal combustion engine

• US 4,372,269 A
• Filed: 02/25/1981
• Issued: 02/08/1983
• Est. Priority Date: 10/24/1980
• Status: Expired due to Term

• Current Assignee: Donald K. Coles
• Original Assignee: Donald K. Coles
• Inventors: Coles, Donald K.
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): Dolinar, Andrew M.
• Application Number:
  US06/238,253
• Time in Patent Office: 713 Days
• Field of Search: 123/436, 123/435, 123/419, 123/487
• US Class Current: 123/436
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 75/16 Engines characterised by number of cylinders, e.g. single-cylinder engines F02B75/26 takes precedence
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration
• CPC Class Codes: F02D 41/1497 With detection of the mechanical response of the engine
• CPC Class Codes: F02D 41/1498 measuring engine roughness

Abstract

A spark-ignition engine has adaptive adjustment of the size of its fuel rations in dependence on misfires in the engine. A misfire is identified as an abnormal deficiency in energy conversion, this being detected by means of a mechanical energy discriminator which compares the quanta of energy derived from different combustion cycles.

The preferred embodiment is a single cylinder engine having a fuel injector valve. The valve is normally closed, being opened for a short interval during each combustion cycle. The size of a fuel ration is regulated by varying the duration of opening of the valve. The duration of opening of the valve is automatically adjusted in dependence on the frequency of misfires in the cylinder. A misfire is detected by means of a decelerometer which compares engine speeds during successive combustion cycles. When a misfire is detected, the fuel rations are automatically increased. Increase of fuel rations is counteracted by gradually decreasing the fuel rations when the engine is firing without an excessive frequency of misfires. Electrical simulation of engine dynamics allows detection of misfires over a wide range of engine speeds and air intake pressures.

Claims

1. An improved internal combustion engine having a combustion chamber, means for metering a series of air rations and for metering a corresponding series of fuel rations, means for mixing each one of the fuel rations with its corresponding member of the series of air rations and firing the resulting mixture in the combustion chamber so as to produce a quantum of energy, the resulting series of energy quanta being delivered to a power output shaft, the improvement comprising:

means for automatically reducing the size of members of the series of fuel rations while the size of the corresponding series of air rations is held constant, the average rate of fractional reduction of size of the fuel rations, when averaged over a thousand consecutive members of the series of fuel rations, not exceeding one half per thousand consecutive members of the series of fuel rations;

a decelerometer including a clock means for generating clock signals having at least two different frequencies and

a digital counter for counting the clock signals from the clock means,

for determining when a momentary deceleration of the shaft speed exceeds a threshold value, and when the excessive deceleration is immediately followed by a reduction of the excessive deceleration to a small value, the momentary deceleration being measured by counting up from a preset value on the digital counter at a first clock frequency during a first angular displacement of the shaft and then counting downward on the counter at a lower second clock frequency during a second angular displacement of the shaft, the threshold value for abnormal deceleration being determined at least in part by the frequency difference between the up count and the down count;

means for automatically increasing the size of succeeding members of the series of fuel rations when the decelerometer determines that the engine has produced a quantum of energy which is abnormally deficient compared to both the immediately preceding and the immediately succeeding members of the series of energy quanta, the single fractional increase in size of the fuel ration not exceeding one fifth when the size of the air ration is unchanged.

2. An internal combustion engine as recited in claim 1 having only one combustion chamber.

3. An internal combustion engine as recited in claim 1 wherein the second clock frequency is lower than the first clock frequency by a difference which increases with the period of the shaft rotation.