Internal-combustion engines – Engine speed regulator – Having condition responsive means with engine being part of...
Patent
1981-03-03
1983-01-18
Cox, Ronald B.
Internal-combustion engines
Engine speed regulator
Having condition responsive means with engine being part of...
123486, 123416, 123358, 123501, F02D 104, F02D 106
Patent
active
043687059
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Technical Field
This invention relates generally to diesel engines and more particularly to a control system for regulating the engine timing advance and the rack limit position of the fuel pump associated with the engine.
2. Background Art
The operation of a diesel engine is controlled basically by varying the amount of fuel delivered to the engine cylinders and by setting the time of fuel injection into the cylinders relative to the time that the pistons reach top dead center on their compression strokes. In general, the amount of fuel delivered to the engine will control the speed of the engine and the timing of fuel injection will affect the efficiency of fuel combustion and engine operation. For example, if the engine speed increases, the timing advance angle of fuel injection must be increased to provide more time in a cycle of operation for compression, ignition and combustion of the injected fuel. If the timing advance is too great, however, ignition and combustion will occur too early in the cycle and the efficiency of operation will be adversely affected.
A typical four-stroke-cycle diesel engine includes a timing shaft which is gear driven by the engine crank shaft at half engine speed, the timing shaft being coupled to the fuel camshaft of a fuel pump by a timing mechanism so that the fuel pump is engine driven and will deliver fuel to half of the engine cylinders during one engine revolution and to the other half of the cylinders during the next revolution. The fuel pump includes a movable, throttle-actuated fuel rack, under the control of the engine operation, to vary the amount of fuel delivered by the pump to the engine, up to the maximum amount permitted by the governor, or rack limit. The timing mechanism will vary the angular relationship between the rotating timing shaft and fuel camshaft to control the time of fuel injection into the cylinders.
The Environmental Protection Agency (EPA) has set Federal emission standards regulating the amount of smoke and gaseous emission which may be exhausted from an engine. Catalytic converters and exhaust gas recirculation have been used to reduce emission to acceptable levels, but at a significant reduction in fuel economy. It is preferable, as in the present invention, to control engine operation so that the fuel in the engine cylinders sufficiently burns and the exhaust components are within the required levels. To achieve the desired degree of combustion of the fuel-air mixture in the cylinders, a sufficient amount of air, relative to the amount of fuel in the mixture must be present for combustion and sufficient time must be allowed for the fuel to burn.
In order to accomplish this, it is necessary to regulate the operation of the fuel pump so that the amount of fuel which the operator can demand, by throttle operation, to be delivered to the cylinders, be limited to that which can be burned with the necessary degree of combustion in the available air in the fuel-air mixture.
At the same time, and in order to provide for maximum allowable engine performance and fuel economy, it may be desired that the engine timing advance not be greater, nor the fuel rack limit be less, than that required to meet the emission standards.
As a consequence, there is a need for an automatic engine control which will precisely regulate engine timing and rack limit so that emission standards are met with the least possible loss of overall engine efficiency.
There are considerable problems involved in providing such an engine control.
If an engine were to be operated at a constant speed and constant load, it would be a relatively simple matter to set the timing and fuel rack for optimal performance. However, that is not the case where vehicle engines are concerned, since many different modes of engine operation are necessary. Operation of the engine while cold will require settings of optimal timing advance for the many various combinations of engine speed and fuel rate which are different from the optimal timing advance for engine operation at normal
REFERENCES:
patent: 3699935 (1972-10-01), Adler et al.
patent: 3796192 (1974-03-01), Locher et al.
patent: 3815564 (1974-06-01), Suoa et al.
patent: 3960120 (1976-06-01), Aono et al.
patent: 3964443 (1976-06-01), Hartford
patent: 4019478 (1977-04-01), Aono et al.
patent: 4048965 (1977-09-01), Bianchi
patent: 4084240 (1978-04-01), Lappington
patent: 4128900 (1978-12-01), Lappington
patent: 4191137 (1980-03-01), Williams et al.
patent: 4205377 (1980-05-01), Oyama et al.
patent: 4212065 (1980-07-01), Marchak et al.
patent: 4217862 (1980-08-01), Fort et al.
patent: 4223654 (1980-09-01), Wessel et al.
patent: 4265200 (1981-05-01), Wessel et al.
Research Disclosure Dated Nov. 1978.
Stevenson Thomas T.
Szentes John F.
Zenios Marios C.
Caterpillar Tractor Co.
Cox Ronald B.
Noe Stephen L.
LandOfFree
Engine control system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Engine control system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Engine control system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-133447