GB2255801A

GB2255801A - Diesel engine air intake control.

Info

Publication number: GB2255801A
Application number: GB9110301A
Authority: GB
Inventors: Martyn Trevor Mercer
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-05-13
Filing date: 1991-05-13
Publication date: 1992-11-18
Also published as: GB9110301D0

Abstract

A throttle valve 11 is opened against spring bias by a diaphragm 15 subject to intake vacuum to reduce the diesel engine air intake at lower speeds. <IMAGE>

Description

D.A.C. - DIESEL AIR CONTROL This invention relates to the D.A.C. - Diesel Air Control HOW DOES IT WORK? The D.A.C. utilises the engine speed to give automatic Air Fuel Ratio control of the engine by a feedback signal to a vacuum diaphragm which controls a throttle plate, this is turn controls the weight of air available to the engine thus achieving optimised values through the load, speed range of the engine. (Refer to illustration of unit) As can be seen since the engine is excess air, the majority of running is in the high Air Fuel Ratios - the poorest area for combustion efficiency. By fitting the D.A.C. and automatically controlling the air mass inducted, optimum combustion efficiency can be achieved.

THIS UNIT GIVES PROVED FUEL ECONOMY: Tests with the D.A.C. have shown a minimum fuel saving of 5% THIS UNIT DESTROYS SLACK SMOKE: The D.A.C. does not add any chemicals, it merely controls the natural element of air in the engine. By improving the combustion efficiency the emissions are reduced.

THIS U2MII' GIVES IMPROVED PERFOSt4LUNC3: A diesel engine is "sluggish" and requires to be "wound up" on acceleration.

The D.A.C.'s close Air Fuel Ratio operating range enhances response.

THIS UIT REDUCES VIBRATION: At low revs (idle), due to the very lean mixture, vibration is a major and extrenely annoying problem. With the D.A.C. the Air Fuel Ratio is improved thus eliminating the lean mixture and the vibration is dramatically reduced.

THIS UNIT REDUCES NOISE: As with vibration the lean mixture at idle causes excessive engine noise. Improved Air Fuel Ratio gives significant reduction in the engine noise levels.

THIS UNIT PRODUCES LONGER NGIL LIFE - LOWER MSINTEìXANCS: A more efficient engine with less vibration results in longer life and reduced maintenance, i.e. engine mounts etc.

THE D.A.C. HELPS CREATE A GREENER ENVIRONMENT PARTICULATES: Soot from a diesel engine is a major problem.

Because of uncontrolled Air Fuel Ratios there is uneven combustion, temperatures and burn rates in the chamber which therefore produces soot (black smoke). Improved combustion performance through controlling the Air Fuel Ratio with the D.A.C. results in the elimination of black smoke and a dramatic reduction in blue smoke.

CARBON MONOXIDE (CO): As the diesel already produces less CO than a petrol engine, by fitting the D.A.C. the CO level is always controlled to minimum output.

HYDROCARBONS: The Hydrocarbon level is a function of the Air Fuel Ratio. The D.A.C. ensures minimum Hydrocarbon levels.

NITROUS OXIDE (NOX): Unfortunately good combustion efficiency increases the level of Nox, but by controlling the Air Fuel Ratio with the D.A.C. they are held within an acceptable level bearing in mind that a diesel engine's emissions of Nox are already well below that of a petrol engine's.

THE PROBLEMS WITH A DIESEL ENGINE ARE: The Diesel engine is an excess air engine which unlike the petrol engine does not control the air supply.

The optimum power, efficiency, emission control and fuel economy from any engine is dependent solely on controlling the Air Fuel Ratio in cylinders.

The Diesel engine could be greatly improved by controlling the air supply to achieve an Air Fuel Ratio in balance with the engine's requirements.

THE AN7WER: It is a popular misconception that if you control the air in a Diesel engine it will not perform properly. Restricting the air will certainly cause a drop off in engine performance, but accurate control by the D.A.C. will give the engine the correct amount of air it requires to improve its performance. Optimum combustion is achieved by having the exact mix of air and fuel - no control of the air means that the diesel will rarely operate at optimum combustion.

At idle the weight of air within the cylinder causes an extremely lean mix. At high revs and load the mixture becomes rich. The volume and weight of air remain constant therefore the fuel pump can only match the air flow to give the correct Air Fuel Ratio over a very narrow R.P.M. and power band.

DIESEL AIR CONTROL - D.A.C.

On a normal Diesel Engine there is no control on the air supply, which means that the engine rarely gives an optimum burn as the air being taken into the engine is not balanced to the fuel supply. When the engine is running at slow speed the amount of air in the engine causes a very weak mixture (i.e. High Air Fuel Ratio). When the engine is running at high revs and load, the mixture becomes very rich. By controlling the air and the fuel in the engine the D.A.C. maximises fuel economy, smooths out the engine and reduces exhaust emissions.

HOW DOES IT WORK Fit the Control in the air intake. By using a vacuum unit fitted to a "butterfly" the unit controls the air going into the engine. When the engine is started the butterfly flap (11) is in the closed position, thus balancing the air to the fuel. When the engine speed is increased it increases the vacuum in the inlet manifold. The depression in the manifold will cause a vacuum on the top of the diaphragm (its) which will raise the diaphragm (15) opening the butterfly (11) to the correc. opening to the engine speed.

The Diesel Air Control - D.A.C. - is made out of Nylon or Acetal which makes it withstand engine vibration and can also be fitted with a speed restrict or by fitting restrictor in the venturee.

GUIDE TO ILLUSTRATION OF UNIT 10 Main Body 11 Butterfly Flap 12 Butterfly Spindle 13 Rubber Tube 14 Crank Arm 15 Diaphragm 16 Larger Internal Return Spring 17 Smaller Internal Override Spring 18 Operating Rod Connected Throw 17 19 Speed Restrictor Optional Fitting 20 Rubber Sealing Rings 21 Swivel Ball Joint 22 Centre Vacuum Unit Spindle

Claims

CL D.A.C.

(Diesel Air Control) Here is the Answer for 'Environment Friendly' Engineers.

The D.A.C. - for Quieter, Smoother, Cleaner and more Economical Diesel Engines.

The D.A.C. (Diesel Air Control) has been designed to simply fit into the air intake of any diesel engine to greatly enhance the operating efficiency.

The D.A.C. (Diesel Air Control) is a very important contributionary factor to answering the problems of Diesel Emissions. By improving combustion it minimises gas and particle emissions and by using less fuel you automatically pollute less.

The D.A.C. (Diesel Air Control) is designed to be fitted after production and is therefore able to give improved emissions to vehicles on the road NOW and not at some point in the future when this system is incorporated into production models.

The D.A.C. (Diesel Air Control) has an optional speed control so that if you want to control the top speed, the D.A.C. will do this without losing the pulling power at low speeds.

I can honestly claim that this product is En-romment2 Wr Friendly.