CN1090014A

CN1090014A - two-stroke internal combustion engine

Info

Publication number: CN1090014A
Application number: CN93101258A
Authority: CN
Inventors: 布赖恩·莱斯利·鲍威尔
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-18
Filing date: 1993-01-18
Publication date: 1994-07-27
Anticipated expiration: 2013-01-18
Also published as: CN1045217C

Abstract

A kind of two-stroke internal combustion engine, it comprise one in pressurized chamber 6 pistons reciprocating 8, one allows scavenging air to be supplied to the suction valve 5 of pressurized chamber with high pressure, one has limited 9 the little volume outer cylinder 3 that is communicated with pressurized chamber 6, one allows a kind of mixed fuel/air mixture mixture is spurted into the valve 2 of firing chamber, this mixture of a part flows into the pressurized chamber and scavenging air wherein forms rare mixture of a kind of fuel and the ignition mechanism 1 of lighting the dense mixture of fuel in the firing chamber, then make the fuel that is firing refire the rare mixture of fuel in the pressurized chamber, make operating temperature in the pressurized chamber keep enough low like this, to suppress to generate nitrogen oxide within it.

Description

Two-stroke internal combustion engine

The present invention relates to a kind of internal-combustion engine, particularly a kind of internal-combustion engine according to the two-stroke cycle operation.The present invention can be applied to any two-stroke internal combustion engine, has the internal-combustion engine and the crankless engine of a conventional crankshaft and connecting rod such as those.

Though two-stroke internal combustion engine has come out century more than one, they still have serious defective and purposes limited.Two-stroke internal combustion engine can run into heating problems usually.In addition, from the waste gas that this motor is discharged, several atmospheric pollutants have been comprised, for example carbon monoxide, hydrocarbon and nitrogen oxide.

Carbon monoxide is toxic gas colourless, odorless, and is light slightly than air.Having this harmful gas in the waste gas effluent is the imperfect combustion result of fuel, and wherein a part of carbon is oxidized to carbon monoxide, rather than is completely oxidized to carbon dioxide.This is because the oxygen deficiency in the firing chamber causes.Most of conventional firing chamber plays bad reaction to the glut of oxygen or to the fuel of a kind of being commonly referred to " rare mixture ".

Exist hydrocarbon to illustrate that also fuel burns incompletely and wastes in the waste gas effluent.In general, in the effluent of two-cycle engine, the percentage of its hydrocarbon-containiproducts all is higher, and this is particularly because the character situation that motor carries out scavenging.Though the hydrocarbon gas of finding usually in atmosphere with concentration is non-toxicity, because their effects in forming photochemical smog, they still are a kind of main pollutant.

When producing nitrogen oxide during with very high temperature combustion fuel under the situation that has oxygen.Nitrogen oxide and hydrocarbon chemical combination form and a kind of thick fog are formed the effective complicated kind secondary pollution that is called photochemical oxidant.In the waste gas effluent, exist nitrogen oxide to become a subject matter of all conventional two-stroke internal combustion engines, especially reduce in the occasion of carbon monoxide with rare mixture that burns in effort.Some test unit is general through rare mixture that successfully burns, but unnecessary oxygen has become nitrogen oxide in the firing chamber, and the catalyst that this nitrogen oxide is only set up a costliness in the past just can be removed.

In forming the nitrogen oxide of air pollutant, that frequent appearance is nitrous oxide (NO) and nitrogen dioxide (NO ₂).Nitrous oxide is a kind of colourless toxic gas that is at high temperature formed by nitrogen and oxygen.It is converted into nitrogen dioxide in the exhaust of internal-combustion engine, a kind of spur and Toxic.

The formation of nitrogen oxide is by too much oxygen, and the temperature of firing chamber exceeds 1650 degree Celsius and piston caused in the withholding period of upper dead center.In the reciprocating engine of a routine, withholding period, can not shorten.Yet, it is found that if the position that had polyoxy is left in the high-temperature zone, nitrogen oxide produces and can be inhibited.

An object of the present invention is to reduce harmful effluent of two-stroke internal combustion engine as far as possible.

Another object of the present invention is to reduce the general heating problems of linking existing two-stroke internal combustion engine of closing as far as possible.

The present invention proposes a kind of two-stroke internal combustion engine, it has a cylinder, pressurized chamber in cylinder, at least one is suitable for piston reciprocating in the pressurized chamber, the suction port that at least one is connected with the pressurized chamber, scavenging air under high pressure is supplied to the device of pressurized chamber by suction port, at least one is used for relief opening that the product of scavenging air and burning is discharged from the pressurized chamber, a little volume outer cylinder that is communicated with the pressurized chamber limitedly, in the firing chamber, spray a kind of device of dense fuel/air mixture mixture, this mixture of a part enters the pressurized chamber and scavenging air wherein forms the rare mixture of a kind of fuel, with being contained on the firing chamber the dense mixture of fuel is wherein lighted a fire, then make burnt fuel light the ignition mechanism of the rare mixture of fuel in the pressurized chamber, its structural configuration will make enough the hanging down with inhibition of temperature maintenance in the on-stream pressurized chamber generate nitrogen oxide within it.

So not only suppressed the generation of nitrogen oxide, and since in the firing chamber the filling part of oxygen supply, fuel is perfect combustion basically also, thereby make the discharging of carbon monoxide and hydrocarbon also reduce to minimum.Big capacity scavenging air by the pressurized chamber is enough to and can please washes and cool off cylinder effectively.Owing to the dense mixture of fuel and the rare mixture of the fuel in the pressurized chamber that fuel are divided in little volume firing chamber, two-stroke internal combustion engine of the present invention has the characteristics of remarkable fuel saving.

With reference to the accompanying drawings two embodiments of the present invention are illustrated, in the accompanying drawing:

Fig. 1 is the sectional view according to the cylinder assembly of single piston two-stroke internal combustion engine of one embodiment of the invention;

Fig. 2 is the sectional view according to the cylinder assembly of the two-stroke internal combustion engine with opposed pistons of second embodiment of the invention;

Fig. 3 is perpendicular to the sectional view of Fig. 1 and 2; With

Fig. 4 is perpendicular to another sectional view of Fig. 2.

Shown in Figure 1 be one has a cylinder assembly that is suitable for the two-stroke internal combustion engine of single piston 8 reciprocating in a cylinder 4.Piston 8 is connected on the connecting rod and bent axle (not shown) of a routine.Except main pressurized chamber 6, also be formed with a little volume exterior combustion chamber 3 in the cylinder 4.Firing chamber 3 separates with pressurized chamber 6, but can be connected limitedly with it along a narrow passage 9.As shown in Figure 3, passage 9 is deflections, so it enters pressurized chamber 6 with the direction of tangent line basically.

Spark plug 1 is installed on the exterior combustion chamber 3 in order to fuel/air mixture mixture is wherein lighted a fire.The fuel/air mixture mixture is to go into firing chamber 3 by a tuned port injection by poppet valve 2 controls.Air is supplied by a blower (not shown).

The general high voltage scavenging air is pressed in the pressurized chamber 6 by a suction port by 5 controls of a poppet valve.Scavenging air is discharged from pressurized chamber 6 together with the product of burning by one or more relief openings 7.The opening and closing of relief opening 7 are realized when it is reciprocating in cylinder 4 by piston 8.

In order to supply jumbo high pressure scavenging air, be provided with a blower (not shown).This same blower also can be used for being supplied as fuel combination and the air of usefulness,, and for the scavenging purpose and, if desired, the air of usefulness for supercharging.Blower can be by engine-driving, if desired, and also can be by means of turbo-exhauster.The supply bond of a large amount of high-pressure air chargings the suitable throughput of scavenging air, not only please wash cylinder and also it cooled off.Effectively cooling segment ground is owing to scavenging air flows downward on the inwall of pressurized chamber 6 and causes along being substantially spiral path with high speed.This vortex type motion of scavenging air in pressurized chamber 6 is what to be facilitated by the suitable project organization of scavenging air suction port.As long as suction port, just can be provided with device such as the fin (not shown) by poppet valve control so that can suitably make its deflection when scavenging air enters pressurized chamber 6.

It is smaller that the suction port of air/fuel mixture is compared with other gas port.Preferably, the suction port of scavenging air and relief opening 7 are than used bigger of the conventional engine of identical size.Bigger suction port and relief opening help supplying the scavenging air of suitable throughput.

Motor is finished a two-stroke cycle operation completely in such a way.Suppose that this circulation is initial and begin in cylinder 4 to rise at its lower dead centre place with piston 8.Poppet valve 5 is closed with the route with scavenging air and cuts off.So will be full of the air of cleaning basically in the pressurized chamber 6.Poppet valve 2 will be or open or be about to and open.In order to prevent that fuel from escaping in the atmosphere when the scavenging, before piston 8 was closed fully or almost completely closed relief opening 7, poppet valve 2 can not opened.

When poppet valve 2 was opened, a kind of dense slightly fuel/air mixture mixture was injected in the exterior combustion chamber 3.A part of fuel/air mixture charging 9 enters in the pressurized chamber 6 from mistress 3 along passage.The layout that is essentially tangent line of passage 9 as shown in Figure 3 makes the charging that enters pressurized chamber 6 and the vorticla motion of wherein air be same direction and spread apart therefrom.The quantity that allows to enter the charging of pressurized chamber 6 depends on desired power and revolution when engine running.Yet, when piston 8 rise and the fuel mix material also fail to descend arrive the position of relief opening 7 in the pressurized chamber 6 before, relief opening 7 has promptly been closed.Under any circumstance, also there is no need to make the fuel mix material to descend above a semipath, because the sole purpose that allows fuel enter pressurized chamber 6 is to dilute so that a kind of rare mixture to be provided with remaining scavenging air to this position.The rare mixture in pressurized chamber 6 and the oxygen of excess impel all fuel perfect combustions.Till supercharging if desired, poppet valve 2 must be opened when piston 8 is closed relief opening 7 fully always.

After poppet valve 2 cut out, piston 8 continued to rise in cylinder 4 and carries out its compression stroke.Air in the cylinder 4 is compressed in passage 9 and the firing chamber 3 in the pressurized chamber 6.Yet the size of passage 9 will make the fuel/air mixture mixture of contiguous spark plug 1 keep enough concentration that it can be blasted by spark ignition thereupon, and this blast can force the fuel that is firing to enter pressurized chamber 6 along passage 9.Mix with scavenging air and thinning left charging is lighted by dense charging burning, need not ignite promptly to take fire.When burnt fuel was pressed into pressurized chamber 6 with the identical direction of vorticla motion of the air in it, the speed of air flows had increased and has promoted burning.

Relation between firing chamber 3 and the pressurized chamber 6 is such, and promptly they cause the significantly different district that separates of two its temperature.At first, the center near blast produces a high-temperature zone in firing chamber 3.Secondly, obviously lower district of a temperature is arranged in pressurized chamber 6.Consequently, the high-temperature zone of firing chamber 3 is separated effectively with the excess oxygen of pressurized chamber's 6 interior rare mixtures.The low generation that the temperature of excess oxygen is enough with the inhibition nitrogen oxide.In addition, because the existence of excess oxygen reaches perfect combustion basically, do not contain carbon monoxide and hydrocarbon in the waste gas effluent thereby make.Another consequence is that the to-and-fro motion of piston 8 in cylinder 4 is cool operation, thereby motor has just been avoided the traditional heating problem relevant with two-stroke engine usually.

So power stroke then carries out exhaust, at this moment piston 8 exposes relief opening 7.At this moment poppet valve 5 is being opened, and scavenging air is pressed into pressurized chamber 6 so that with cleaned air it being removed the end cleans, and cooling cylinder 4.

Cylinder structure shown in Figure 2 is in order to be used for horizontally-opposed piston.Used label is the same with the maintenance among Fig. 1 with the running principle among this figure, and the gas port 15 that is being unlocked except the poppet valve 5 of Fig. 1 replaces, and this gas port is opened and closed by one in the pistons reciprocating 8.Gas port 15 is to be arranged on like this on the cylinder 4, and promptly relief opening 7 just in time exposed so that exhaust before gas port 15.As shown in Figure 4, the suction port 15 of scavenging air is a bevel, thereby air is to enter pressurized chamber 6 with the direction that is essentially tangent line, so that produce a kind of vorticla motion of scavenging air within it.

An advantage of this motor is that relief opening 7 can not be restricted around the periphery of cylinder 4.This is because there is not the reason of transfer port, and this transfer port all is necessary on the relief opening of the two-stroke engine of most of routine, but it does not need in the present invention's design.So just allow more effectively ventilation.

Apparatus of the present invention also allow conventional two-stroke engine to use wet oil groove fuel feeding lubricating method in the running, because do not need lubricant oil in the fuel.The size dimension of motor can be competed mutually with four stroke engine.

Above-described two-stroke engine can be suitable for using a kind of in the large-scale various fuel, for example gasoline, coal gas and diesel oil and without any need for special additive.

Relief opening 7 and suction valve 5 can be exchanged according to the described embodiment of Fig. 1, thereby the flow pattern of scavenging air is reversed.The advantage of this arrangement is that any remaining waste gas and any may can returning in the firing chamber 3 by piston 8 escaping gas go in expansion stroke.

In another kind of improved type, the embodiment of Fig. 1 and 2 can dispose one by the other suction port of poppet valve control with so that scavenging air enter in the firing chamber 3.This can make firing chamber 3 and passage 9 obtain scavenging.This arrangement is suitable for big-block engine.

In another improved type, the gas port that adds in addition in the firing chamber can be used as relief opening.Any gas of overflowing by piston 8 in expansion can return in the firing chamber 3 like this.In addition, any unburned hydrocarbon will be oxidized through overheated firing chamber 3 time.

In another embodiment, pressurized chamber 6 can be equipped with a big relief opening by a poppet valve control, thereby other gas port of pressurized chamber 6, and if any, the gas port that adds in addition of firing chamber 3 can be arranged to use as the suction port of scavenging air.

In above-mentioned any embodiment, can dispose outer cylinder 3 more than one, especially true in big-block engine.Firing chamber 3 respectively has a passage 9, and can turn up the soil separately be centered around pressurized chamber 6 around.In addition, motor can use the cylinder 4 more than.

As previously mentioned, passage 9 is essentially the layout of tangent position, as shown in Figure 3, make the fuel-feed that enters pressurized chamber 6 and in it vorticla motion of air be in same direction and by to spread apart.This is general situation.Yet,, have necessity and make fuel-feed enter pressurized chamber 6 so that weaken the strong excessively vorticla motion of air against the direction of vortex for the motor of certain displacement volume.Under the sort of situation, still have effective diffusion of fuel-feed.

Other improvement pattern of above-mentioned details for person skilled in the art in the industry all be very easily understand and can make various variations and the summary inventive concept that do not break away from here to be narrated.For example, can dispose radiating fin on the outer surface of cylinder to assist cooling.

Claims

1, a kind of two-stroke internal combustion engine, it comprises a cylinder, pressurized chamber in cylinder, at least one is suitable for piston reciprocating in the pressurized chamber, the suction port that at least one is connected with the pressurized chamber, scavenging air under high pressure is supplied to the device of pressurized chamber by suction port, at least one is used for relief opening that the product of scavenging air and burning is discharged from the pressurized chamber, a little volume outer cylinder that is communicated with the pressurized chamber limitedly, in the firing chamber, spray a kind of device of dense fuel/air mixture mixture, this mixture of a part enters the pressurized chamber and scavenging air wherein forms the rare mixture of a kind of fuel, with being contained on the firing chamber the dense mixture of fuel is wherein lighted a fire, then make burnt fuel light the ignition mechanism of the rare mixture of fuel in the pressurized chamber, this structural configuration will make enough the hanging down of the temperature maintenance in the on-stream pressurized chamber wherein generate nitrogen oxide to be suppressed at.

2, internal-combustion engine as claimed in claim 1 is characterized in that: wherein, air inlet is designed to cause the vorticla motion of scavenging air in the pressurized chamber.

3, internal-combustion engine as claimed in claim 2 is characterized in that: wherein, fin of configuration is so that the scavenging air deflection that enters causes vorticla motion on the air inlet.

4, internal-combustion engine as claimed in claim 2 is characterized in that: wherein, air inlet is arranged to the drift angle, is oriented in a tangential direction basically to produce vortex movement thereby make air enter the pressurized chamber.

5, internal-combustion engine as claimed in claim 1 is characterized in that: wherein, a narrow passage provides limited connection between firing chamber and pressurized chamber.

6, internal-combustion engine as claimed in claim 5 is characterized in that: wherein, passage is setovered, and makes it enter the pressurized chamber with the direction that is essentially tangent line.

7, internal-combustion engine as claimed in claim 1 is characterized in that: wherein, passage is arranged to make fuel to enter the pressurized chamber with the direction identical with air swirl motion in the pressurized chamber.

8, internal-combustion engine as claimed in claim 1 is characterized in that: it has a gas port that adds in addition to carry out its scavenging work in the firing chamber.

9, internal-combustion engine as claimed in claim 1 is characterized in that: wherein, be provided with the scavenging air of an external blower to pressurized chamber's supply high pressure.

10, internal-combustion engine as claimed in claim 9 is characterized in that: wherein, blower is the supply of the fuel mix material in spurting into firing chamber air also.

11, internal-combustion engine as claimed in claim 1 is characterized in that: it has a plurality of outer cylinders, turns up the soil separately and be distributed in the also coupled logical of pressurized chamber all around in those firing chambers.