Waste-gas scavenging engine
Technical field
The present invention relates to technical field of engines, more particularly, relate to a kind of waste-gas scavenging engine.
Background technique
Internal-combustion engine has greatly promoted the development of human society and people's growth in the living standard since invention is come out.The many merits such as two-stroke gasoline engine is higher with its power, smooth running, structure and manufacturing are simple are widely used in motorcycle and other is mechanically light.
Present our widely used two-stroke gasoline engine, owing to being to purge ventilation with the waste gas after the internal combustion of inflammable mixture countercylinder firing chamber, fresh inflammable mixture is inhaled into first in the crankcase, when descent of piston, compressed combustible gas in the crankcase, enter cylinder chamber by scavenging port again, incoming mixture has the effect of residual gas being extruded cylinder chamber, namely " scavenging ", so just exist the mutual blending of combustible gas and waste gas inevitably, do not have obvious separatrix between them.In order to make the indoor residual exhaust gases of as far as possible lacking of combusted cylinder, will inevitably some inflammable mixture without work by combustion, just discharge machine by relief opening outer and slatterned in vain.Simultaneously, a part of mixed gas is in waste gas blending process, because the effect of anoxic and high-temp waste gas is decomposed outside the generation poisonous and harmful substance discharge machine, further increases the weight of and worsened exhaust emission.Simultaneously, existing two-stroke gasoline engine is in order to reduce gas exchange loss as far as possible, scavenging port designs lowlyer than relief opening, yet when piston stroking upward, closes first scavenging port, after close relief opening, in period, in the namely scavenging later stage, the indoor a part of combustible gas of combusted cylinder then is extruded outside the machine by relief opening at this section, so not only waste fuel, more increased the weight of pollution.
Therefore, how to provide a kind of waste-gas scavenging engine, utilize the former row of waste gas reduction motor with realization, thereby the control exhaust index is present those skilled in the art's problem demanding prompt solution.
Summary of the invention
In view of this, the invention provides a kind of waste-gas scavenging engine, to realize reducing the former row of motor, the control exhaust index.
In order to achieve the above object, the invention provides following technological scheme:
A kind of waste-gas scavenging engine, comprise cylinder block, piston, relief opening, exhaust passage, crankshaft cavity, scavenging air belt, scavenging port and crankcase, be provided with the exhaust gas recirculation passage that is connected with described exhaust passage and described scavenging air belt on the described cylinder block, the outlet side of described exhaust gas recirculation passage is provided with the one-way valve of being opened to described scavenging air belt direction by described exhaust gas recirculation passage.
Preferably, in above-mentioned waste-gas scavenging engine, the outlet side of described exhaust gas recirculation passage is arranged at the top of described scavenging port.
Preferably, in above-mentioned waste-gas scavenging engine, be provided with two described exhaust gas recirculation passages that are connected with two described scavenging air belts respectively on the described cylinder block, it is positioned at the both sides of described relief opening.
Preferably, in above-mentioned waste-gas scavenging engine, the top of the inlet end of described exhaust gas recirculation passage and described relief opening are positioned on the sustained height line.
Preferably, in above-mentioned waste-gas scavenging engine, described one-way valve is arranged at the top of described scavenging air belt.
Preferably, in above-mentioned waste-gas scavenging engine, when being lower than the air pressure of outlet side of exhaust gas recirculation passage, opens the air pressure of described one-way valve in described scavenging air belt.
In the waste-gas scavenging engine provided by the invention, after flammable mixed oil and gas detonation in the cylinder block firing chamber, internal volume increases rapidly, when pushing piston comes downwards to relief opening, the waste gas overwhelming majority after the burning is discharged through the exhaust passage from relief opening, a part enters the exhaust gas recirculation passage, the one-way valve of opening exhaust gas recirculation passage afterbody by self pressure enters scavenging air belt, the pressure at scavenging air belt top is higher than the pressure of gas in the crankcase at this moment, therefore the mixed oil and gas to be burnt that enters in the scavenging air belt is pressed to crankcase again, has stoped the incendivity mixed oil and gas to enter the firing chamber and discharges with the waste gas after the burning and to affect discharging.Piston continues when descending, crankcase pressure increases gradually, along with relief opening is all opened, exhaust pressure is dwindled gradually, when the air pressure in the scavenging air belt is higher than the air pressure of outlet side of exhaust gas recirculation passage, the one-way valve autoshutdown, this moment the piston approaches bottom dead centre, the bent axle loading pressure constantly increases, cause the movement of oppositely rising of gas in the scavenging air belt, open when the scavenging port of cylinder block inwall, deposit the burned gas ratio that is pressed in upper strata in the scavenging air belt and be introduced into piston head, original residual gas in the firing chamber is accelerated to scan out relief opening and stop mixed oil and gas to be fired to be escaped with waste gas.The present invention imports scavenging air belt by the exhaust gas recirculation passage with high pressure exhaust gas, the pressure that the recycling crankcase scavenging produces is the waste gas pressurization to refluxing again, waste gas after the pressurization enters the process that cylinder cleans out original residual gas in the firing chamber fast, reduced mixed oil and gas to be fired with the discharge capacity of waste gas, reduce former row's value of motor, thereby controlled exhaust index.
Description of drawings
In order to be illustrated more clearly in the embodiment of the invention or technological scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the main sectional view of waste-gas scavenging engine provided by the invention;
Fig. 2 is the left sectional view of waste-gas scavenging engine provided by the invention.
Among the upper figure:
1 is that cylinder block, 2 is that one-way valve, 3 is that end cap, 4 is that scavenging air belt, 5 is that crank, 6 is that bent axle, 7 is that crankcase, 8 is that crankshaft cavity, 9 is that piston, 10 is that relief opening, 11 is that exhaust gas recirculation passage, 12 is that scavenging port, 13 is that firing chamber, 14 is that exhaust passage, 15 is gas-entered passageway.
Embodiment
The invention discloses a kind of waste-gas scavenging engine, to realize utilizing waste gas that motor is carried out scavenging, reduce the former row of motor, thereby controlled the exhaust index of motor.
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technological scheme in the embodiment of the invention is carried out clear, complete description, obviously, described fact Example only is the present invention's part fact Example, rather than whole embodiments.Based on embodiments of the invention, those of ordinary skills belong to the scope of protection of the invention not making the every other embodiment who obtains under the creative work prerequisite.
Please referring to illustrated in figures 1 and 2, Fig. 1 is the main sectional view of waste-gas scavenging engine provided by the invention, and Fig. 2 is the left sectional view of waste-gas scavenging engine provided by the invention.
The waste-gas scavenging engine that the present embodiment provides, comprise cylinder block, piston, relief opening, exhaust passage, crankshaft cavity, scavenging air belt, scavenging port and crankcase, be provided with the exhaust gas recirculation passage that is connected with exhaust passage and scavenging air belt on the cylinder block, the exhaust gas recirculation passage can be realized the connection of scavenging air belt and exhaust passage.The outlet side of exhaust gas recirculation passage is provided with the one-way valve of being opened to the scavenging air belt direction by the exhaust gas recirculation passage, when waste gas is discharged, pass through first the exhaust passage, gas pressure is higher than gas pressure in the scavenging air belt in the exhaust passage at this moment, one-way valve opens, waste gas enters in the scavenging air belt from the exhaust passage by the exhaust gas recirculation passage.
The waste-gas scavenging engine working procedure that provides in the present embodiment is as follows:
After the flammable mixed oil and gas detonation in the cylinder block firing chamber, internal volume increases rapidly, pushing piston come downwards on the relief opening along the time, high temperature after the burning, the high pressure exhaust gas overwhelming majority is discharged through the exhaust passage from relief opening, a part is by the exhaust gas recirculation passage, the one-way valve of opening exhaust gas recirculation passage afterbody by self pressure enters scavenging air belt, the pressure at scavenging air belt top can be higher than the pressure of gas in the crankcase at this moment, therefore the mixed oil and gas to be burnt that enters in the scavenging air belt is pressed to crankcase again by the high pressure reflow waste gas on upper strata, has stoped the incendivity mixed oil and gas to enter the firing chamber and discharges with the waste gas after the burning and to affect discharging.When piston continues when descending, crankcase pressure increases gradually, along with relief opening is all opened, exhaust pressure is dwindled gradually, when the scavenging air belt internal pressure is higher than the outlet side pressure of exhaust gas recirculation passage, the one-way valve autoshutdown, this moment the piston approaches bottom dead centre, the bent axle loading pressure constantly increases, cause the movement of oppositely rising of gas in the scavenging air belt, open when the scavenging port of cylinder block inwall, deposit the backflow burned gas ratio that is pressed in upper strata in the scavenging air belt and be introduced into piston head, original residual gas in the firing chamber is accelerated to scan out relief opening and stop mixed oil and gas to be fired to be escaped with waste gas.
Can draw by above-mentioned scavenging process, waste-gas scavenging engine provided by the invention, by the exhaust gas recirculation passage high pressure exhaust gas is imported scavenging air belt, the pressure that the recycling crankcase scavenging produces is the waste gas pressurization to refluxing again, waste gas after the pressurization enters the process that cylinder cleans out original residual gas in the firing chamber fast, reduced mixed oil and gas to be fired with the discharge capacity of waste gas, reduced former row's value of motor, thereby controlled exhaust index.
In order further to optimize technique scheme, in the waste-gas scavenging engine that provides in above-described embodiment, the outlet side of exhaust gas recirculation passage is arranged at the top of scavenging port, waste gas is when flowing into scavenging air belt by the exhaust gas recirculation passage, because the effect of exhaust pressure is pushed the mixed oil and gas to be fired in the scavenging air belt to the engine crankcase direction, can play when avoiding scavenging port to open, the scavenging port top is deposited the mixed oil and gas to be fired of pressure and is discharged with waste gas, has reduced the discharging of mixed oil and gas and has escaped.
In order further to optimize technique scheme, in the waste-gas scavenging engine that provides in above-described embodiment, be provided with two exhaust gas recirculation passages that are connected with described scavenging air belt respectively on the cylinder block, it is positioned at the both sides of relief opening, and the top of the inlet end of exhaust gas recirculation passage and described relief opening are positioned on the sustained height line.Concrete, a little higher than relief opening in the top of the inlet end of exhaust gas recirculation passage.After in original two scavenging air belts the exhaust gas recirculation passage being set all in the waste-gas scavenging engine, guaranteed that the mixed oil and gas to be fired in the scavenging air belt is all pressed to crankcase by waste gas, avoided mixed oil and gas to be fired to discharge with waste gas in exhaust process because of the mixed oil and gas to be fired that gas pressure imbalance in the passage causes, the exhaust gas recirculation passage is arranged symmetrically with about relief opening, balance the pressure of gas in the scavenging air belt, thereby guaranteed that mixed oil and gas to be fired can not discharge in a large number motor with waste gas and reduce the former row of motor.
In order further to optimize technique scheme, in the waste-gas scavenging engine that provides in above-described embodiment, one-way valve is arranged at the top of described scavenging air belt, when one-way valve is opened when the internal air pressure of scavenging air belt is lower than the air pressure of outlet side of exhaust gas recirculation passage.When descent of piston arrived relief opening, waste gas was discharged through the exhaust passage from relief opening, and the pressure of waste gas still is higher than the scavenging air belt internal pressure in the exhaust passage at this moment, and scavenging air belt is in negative pressure, and one-way valve is opened, and backflow waste gas enters scavenging air belt; The backflow waste gas of this moment enters the scavenging air belt top, mixed oil and gas is owing to the pressure that is subject to high pressure reflow waste gas is pressed towards crankcase in the scavenging air belt, one-way valve is arranged at the scavenging air belt top, when having guaranteed that waste gas enters, mixed oil and gas in the scavenging air belt all is discharged from, and has avoided the top to have remaining mixed oil and gas and affects exhaust index.
When descent of piston is opened to scavenging port, the backflow waste gas that has entered in the scavenging air belt reenters the firing chamber under the pressure of crankcase, original residual gas in the firing chamber is accelerated to scan out relief opening and stop mixed oil and gas to be fired to be escaped with waste gas, reduced former row's index of motor.When waste gas substantially discharge complete after mixed oil and gas enter the firing chamber, motor begins to enter next circulation.
Can find out by above process, the waste-gas scavenging engine that provides in above-described embodiment, utilize spent waste gas as the scavenging medium, scavenging process utilized in different exhaust spaces and time difference, the pressure difference that reaches gas between each passage realizes the function of waste gas scavenging, avoided mixed oil and gas to be fired to discharge the outer situation of motor with waste gas, thereby the former row who has reduced motor effectively control exhaust index.
To the above-mentioned explanation of the disclosed embodiments, make related domain professional and technical personnel can realize or use the present invention.Multiple modification to these embodiments will be apparent concerning those skilled in the art, and General Principle as defined herein can be in the situation that do not break away from the spirit or scope of the present invention, in other embodiments realization.Therefore, the present invention will can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.