CN102758683A

CN102758683A - Lean burn engine

Info

Publication number: CN102758683A
Application number: CN201110104415XA
Authority: CN
Inventors: 毛庆平
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-25
Filing date: 2011-04-25
Publication date: 2012-10-31

Abstract

The invention relates to a lean burn engine. Gas entering a cylinder is split and the flow direction of gas flow is controlled, so that part of air entering the cylinder cannot be sufficiently mixed with fuel; the fuel concentration of the gas at each part in the cylinder is different; and the fuel concentration of the gas close to a spark plug (1) is relatively high, so that the gas close to the spark plug (1) is easy to ignite to cause stratified combustion so as to fulfill the aim of lean combustion.

Description

A kind of lean-combustion engine

Affiliated technical field:

The present invention relates to a kind of energy-saving engine, practice thrift the consumption of automobile gasoline through lean combustion, thus reach fuel-efficient with reduce discharge of harmful gases, slowed down greatly human to the energy consumption and reduce pollution to environment.

Background technique:

The energy is the material base of mankind's activity.Say that in a sense development of human society be unable to do without the appearance of high-grade energy and the use of advanced energy technology.In the world today, the development of the energy, the energy and environment are the whole world, whole mankind's questions of common interest.

According to economist and scientist's generally estimation,, also be about the year two thousand fifty to the middle of this century; Petroleum resources will be exploited totally; Its price is raised to very high, when being inappropriate for popular popularization and application, if new energy system is set up as yet; Energy crisis will have swept the globe, and the developed country that greatly depends on petroleum resources with the America and Europe especially is injured and attaches most importance to.The most serious state no more than industry atrophy significantly, or even produces a war because seizing remaining petroleum resources.

Along with energy crisis is closed on day by day, each state is all readjusting the energy structure, and vigorously implements energy-saving and emission-reduction, to delay energy consumption and the pollution that reduces environment.Wherein be mainly reflected in the automobile aspect, automobile has become important component part indispensable in people's daily life as the traffic tool.The generally use of automobile will change the economic society structure, form a whole set of new economy, culture, life system, improve people's quality of life, advance social progress, promote economic development.But the non-renewable energy resources that automobile will consume just let earth resource be close to exhaustion, and the cost of resource and environment has been paid in the fast development of automobile.Each state is all at the motor of putting forth effort to study energy-conservation or alternative energy source for this reason, and some motor corporation has developed lean-combustion engine, can save the consumption of automobile to gasoline greatly.

Lean-burn is exactly that gasoline content in the engine mixed gas is low, and gasoline can reach more than 1: 25 with the ratio of air.

Understand lean combustion, just will understand the air fuel ratio of motor earlier.Air fuel ratio is meant the air of suction cylinder in the engine charge stroke and the ratio of fuel oil (gasoline) weight, that is to say that the air in the mixed gas and the ratio of fuel oil are called air fuel ratio.When gasoline and air mixing burning, air quantity is too much perhaps very few all can not effectively burn.The necessary AIR Proportional of gasoline perfect combustion can obtain according to theoretical calculation, and is referred to as chemically correct fuel.Specifically, a gasoline is to 14.7 parts of air.Therefore chemically correct fuel is 14.7.Must change air fuel ratio according to the operating mode of motor.

In having the motor of triple effect catalytic converter, motor must be adjusted to chemically correct fuel, 14.7: 1.When part was with closure to open, general motor was with thinner mixed gas, and promptly air fuel ratio is at 15-16: turn round 1 scope in, but in lean combustion engine, will be with more thin mixed gas, promptly air fuel ratio is greater than 18.

The maximum characteristics of Lean Burning Technique are exactly the combustion efficiency height, and economy, environmental protection can also promote the power output of motor simultaneously.Because under the condition of lean combustion; Because ignition of mixed gas is than difficulty under the chemically correct fuel condition; Deflagration is also with regard to more difficult generation; Therefore can adopt higher compression ratio design to improve thermal energy conversion efficiency, adding gasoline can fully burn in excessive air, so under the support of these conditions, can squeeze all energy of every gasoline.

Spray petrol engine (GDI) in more famous Mitsubishi's cylinder can make proportions of ingredients reach 40: 1.It adopts vertical intakeport mode, and the unique way air-breathing from the top of cylinder head produces powerful downward flow.This downward flow is strengthened near the curved top surface piston and in cylinder, is formed the longitudinal shrinking turbulence turn of tidal stream.Under the effect of high-pressure rotary ejector filler, the compression process later stage is formed dense spraying by the fuel in the direct spray inlet casing, and being sprayed in the end face space of curved top surface piston is not diffusion but gasification.

Popular straight spray petrol engine (FSI) then is to have adopted a high-pressure service pump, and gasoline arrives the high-pressure injection valve of Electromagnetic Control through a shunting track (rail altogether).Its feature is in intake duct, to have produced variable vortex, makes inlet stream form best eddy current form and gets in the firing chamber, and the mode of filling with layering promotes, and mixed gas is concentrated on be positioned at around the spark plug of firing chamber central authorities.

The up-to-date VTEC motor of Honda also will adopt lean burn technology.This is named as 2.0 liters of motors of VTEC-i will be than general Honda motor fuel-efficient 20%; Be characterized in the VTEC technology is combined with lean burn technology; Also be when one group of IC Intake Valve Closes wherein in slow-speed of revolution season; In the firing chamber, form one thin mixed gas eddy current, layered arrangement is lighted ignition around concentrating at spark plug, thereby plays the lean combustion effect.

Along with the increase of air fuel ratio, engine consumption obviously descends, and this is mainly from the reason of several aspects: at first be that thermal efficiency of cycle improves when adopting the lean mixture gas firing.The actual cycle of petrol engine approaches the constant volume heat cycles, and the relation of the indicated thermal efficiency of constant volume heat cycles and compression ratio and adiabatic index can be seen, improves the adiabatic index of working medium and the raising that compression ratio helps indicated thermal efficiency.Along with the raising of air fuel ratio, the shared amount of air increases, so the adiabatic index of working medium moves closer to the adiabatic index in air, and in theory, when air fuel ratio reached infinity, the thermal efficiency reached maximum value.In addition, because lean-burn mixture combustion temperature is low, the disassociation of products of combustion loss reduces, and has reduced the heat transfer with cylinder wall surface, and the thermal efficiency is improved.Because the restriction of the knock limit when lean-combustion engine does not generally receive high load can be adopted higher compression ratios, helps the raising of the thermal efficiency.When adopting the lean mixture gas firing; Increase owing to get into the amount of air in the cylinder, reduced pump and inhaled loss, this improvement to petrol engine sub load Economy is clearly; Also can adopt simultaneously rotten the adjusting; Without closure or little throttling, can inhale loss by less greatly pump, be particularly conducive to the improvement part load performance.

But, along with the increase of air fuel ratio, owing to adopt rare mixed gas that FT is reduced; The discharging of NOx obviously reduces, and the oxygen composition in the products of combustion helps the oxidation of HC and CO simultaneously, therefore; The discharging of HC and CO also reduces, yet, along with air fuel ratio is increased to a certain degree; Because the reduction of velocity of combustion may make incomplete combustion, the discharging of HC can increase sharply.If can firing chamber reasonably compact to design, and organize air movement burning is accomplished at short notice, three kinds of dischargings can significantly reduce so.

In addition; Lean-combustion engine is because the adding of sparger has caused all suitable height of requirement to design and manufacturing; If arrange that unreasonable, accuracy of manufacturing does not reach requirement and causes insufficient rigidity even gas leakage to lose more than gain, render to wide model application on the market so can't become main product.

Summary of the invention:

Technological scheme such as Fig. 1-1 that the present invention adopts; Shown in the 1-2: the gas that will get into cylinder is shunted before the unmixed fuel in suction tude; Make partly the gas can not be fully and fuel mix, and control the opening and closing of two or more air inlet split channels simultaneously, make the gas of entering cylinder in cylinder, form convection current by a cylinder valve; The fuel concentration of each position gas is all different in the cylinder; The air-flow that gets into cylinder near the gas-entered passageway of spark plug one side is the gas through fuel combination, and these can concentrate near the spark plug after getting into cylinder, are easy to when plug ignition, fire burns; Near the air-flow of the cylinder that gas-entered passageway gets into of piston one side gas without mix fuel; The attraction force steering flow that is produced by piston motion flows to; The air-flow of air and mixed gas can form backflow separately when impact piston; These air that get into cylinders can distribute be filled in around the cylinder wall with piston near, thereby improved the ratio of interior air of cylinder and gasoline on the whole, finally reach the purpose of lean combustion.

The lean-combustion engine of each producer's development all adopts the in-cylinder direct injection fuel system at present, and this motor is quite high to the requirement of design and manufacturing process; And can increase the cost of making and safeguarding, the invention has the beneficial effects as follows: adopts traditional in the past oil spout mode, can realize the air-flow of entering cylinder is shunted and led; The trend of control gaseous in cylinder lets the mixed gas that reaches chemically correct fuel concentrate at around the spark plug, and burning can be accomplished at short notice; Reduce the generation of harmful gas; Reach environmental protection and fuel-efficient purpose, and good leak tightness, practical.

Description of drawings

Below in conjunction with accompanying drawing the present invention is further specified:

Fig. 1-1,1-2 are schematic diagrams of the present invention

Fig. 1-the 3rd, the schematic diagram of the function of air intake valve

Among Fig. 1-1 1, suction port 2, spray bar 3, valve rod 4, spring 5, relief opening 6, spark plug 7, mixed gas 8, piston 9, cylinder valve 10, air 11, cylinder wall 12, air throttle 13, mixed gas manifold 14, air manifold

Among Fig. 1-2 1, spark plug 2, oil nozzle 3, separation baffles or cut off 4, suction tude 5, air throttle 6, fuel tank 7, air throttle 8, control system 9, piston 10, firing chamber

Among Fig. 1-3 1, valve rod 2, flow distribution plate 3, cylinder valve

Embodiment

In Fig. 1-1: suction port (1) will get into the air of cylinder and shunt, and when the air process spray bar (2) of process gas-entered passageway (13), mix formation fuel mix air-flow with the fuel of ejection, from getting into cylinder near spark plug one side; The air that passes through gas-entered passageway (14) does not in addition mix with fuel; In cylinder, form convection current with the fuel mix air-flow; The attraction force steering flow that is produced by piston motion flows to, and two kinds of air-flows can form backflow separately when impact piston, and fuel mix gas adfluxion is tied at spark plug (6) on every side; Be easy to ignition, thereby guarantee the ignition at short notice of fuel mixture physical efficiency; Gas gets into the flow of cylinder can regulate the ratio that changes air and mixed gas in the cylinder through air throttle (12), improves the air fuel ratio of the interior gas of cylinder on the whole to greatest extent, finally realizes the purpose of energy-conservation fuel-efficient and environmental protection.

In Fig. 1-2: (is preceding with airintake direction) is separated into two or more zones with suction tude in the preceding position of oil nozzle (2) for separation baffles or partition (3), until the cylinder valve place.Its effect be air with it is advanced shunting before fuel mixes; Make the part air that gets into cylinder can not be fully and fuel mix; The fuel concentration of each position gas is all different in the cylinder like this, and is higher relatively near the fuel concentration of gas spark plug (1), is easy to catch fire; Cause stratified mixture combustion, thereby reach the purpose of lean combustion.

In Fig. 1-3: when gas got into cylinder, cutoff board (2) played a part to separate and guiding gas flows to.

Claims

1. a lean-combustion engine can be shunted the gas that gets into cylinder, and the flow direction of control air-flow, and it is characterized in that: a cylinder valve is being controlled the opening and closing of two or more inlet holes simultaneously.

2. lean-combustion engine according to claim 1 is characterized in that: be provided with separation baffles or partition in the suction tude of cylinder.

3. lean-combustion engine according to claim 1 is characterized in that: the suction tude of cylinder is distinguished through the gas gas passage of fuel combination and the gas channel of unmixed fuel, and shared their air inlet of cylinder valve control.

4. lean-combustion engine according to claim 1 is characterized in that: cylinder valve connecting rod or connecting rod parallel position are provided with flow distribution plate, and cylinder valve is provided with splitter box.

5. lean-combustion engine according to claim 1 is characterized in that: the piston top be provided with the gas splitter box (position, piston head air-flow watershed is projection a little, is formed slopely groove to both sides, to piston skirt more a little projection form the recovery state).