CN1039846C - Exhaust gas purifier for two-cycle engine - Google Patents
Exhaust gas purifier for two-cycle engine Download PDFInfo
- Publication number
- CN1039846C CN1039846C CN93108982A CN93108982A CN1039846C CN 1039846 C CN1039846 C CN 1039846C CN 93108982 A CN93108982 A CN 93108982A CN 93108982 A CN93108982 A CN 93108982A CN 1039846 C CN1039846 C CN 1039846C
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- CN
- China
- Prior art keywords
- flow
- limiting valve
- outlet pipe
- exhaust
- throttle valve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Exhaust Gas After Treatment (AREA)
- Characterised By The Charging Evacuation (AREA)
- Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Exhaust Silencers (AREA)
Abstract
To improve uneven combustion apt to be generated at the time of low rotation, low throttle valve opening, and the like, and also improve the increase of discharge of hydrocarbon into exhaust in a two-cycle engine utilizing exhaust pulsation in order to improve output during high rotation. A two-cycle engine 16 is provided with a throttle valve 24 in an exhaust pipe 22. This throttle valve 24 is interlocked with a throttle valve 39 so as to throttle exhaust passage area when the throttle valve opening is low. In this case, the throttle valve 24 is formed in such a way that the ratio Ks of the exhaust passage area throttled by this throttle valve 24 to the sectional area of the exhaust pipe 22 satisfies the relation of 0.02<=Ks<=0.4, and provided in such a position that the ratio Kv of the exhaust pipe internal volume from the cylinder face to the throttle face, to engine exhaust quantity satisfies the relation of 1<=Kv<=5.
Description
The present invention relates to a kind of catalytic converter of two stroke engine, especially relate to a kind of catalytic converter that hydrocarbons content reduces in the waste gas that makes.
In two stroke engine, the exhaust pulsation is utilized to improve output power.In other words, piston move up above the lower dead centre and closing scavenge port after close relief opening, at this constantly, because exhaust pulsation and produce positive pressure in exhaust ports, this positive pressure can be used to prevent to miss fresh air.
Yet above-mentioned harmonious property between exhaust pulsation and piston stroke designs when the high rotary speed working by motor, and has just lost this harmonious property when engine low rotation speed.When the slow-speed of revolution, when closing scavenge port and relief opening, what produce in exhaust ports is negative pressure, and this negative pressure tends to make fresh air to sew.Especially under the less situation of throttle opening, because original FAI Fresh Air Intake amount is just smaller, therefore motor may lack fire sometimes in this case, thereby causes non homogeneous combustion.Its consequence is to have increased fuel consumption, and contains a large amount of unburned hydrocarbons (hereafter is HC) in waste gas.
In order to address this problem, postpone in open 60-72925 number in the disclosed engine output regulator in Japanese Utility Model, with outlet pipe that engine exhaust port links to each other in establish a cavity, rotating fly valve is housed in the chamber, leave the gap between the inner circumference in this fly valve and chamber, the opening and the interlock of pass and closure of fly valve.
Being intended that of above-mentioned prior art limited the waste gas circulation by installing a flow-limiting valve, and flow-limiting valve for example is above-mentioned fly valve, and it is used for reducing the HC content in the waste gas, thus purifying exhaust air.Yet in order to reach this purpose, only installing is not enough with the flow-limiting valve that closure links in outlet pipe, because the geomery of outlet pipe is different to various cylinder swept volumes, and exhausted air quantity is also inequality.
Please disclose a kind of internal combustion engine exhaust system by EP0278032 in the European patent, it is intended that the output characteristics of improving quartastroke engine.In its outlet pipe, be provided with flow-limiting valve, be used to regulate the valid circulation area of waste gas.Yet only adopt this measure to have above-mentioned defective equally, and can't obtain satisfied waste-gas cleaning effect.
In view of the above, the objective of the invention is, the geomery by designing flow-limiting valve more rightly and select the position of flow-limiting valve in outlet pipe more rightly obtains enough waste-gas cleaning effects.
According to the present invention, a kind of catalytic converter that is used for two stroke engine is provided, it comprises single cylinder, single outlet pipe and be located in the outlet pipe flow-limiting valve in order to restriction waste gas circulation area, when hour this flow-limiting valve and closure interlock of throttle opening, it is characterized by: flow-limiting valve is designed to, make the ratio Ks of waste gas circulation area B and outlet pipe sectional area A under flow-limiting valve restriction satisfy relation 0.02≤Ks≤0.4, and flow-limiting valve is arranged on such position, outlet pipe internal volume D between making from the cylinder surface to the flow-limiting valve and the ratio Kv of cylinder swept volume C satisfy relation 1≤Kv≤5.
The position in outlet pipe by specific design flow-limiting valve and definite flow-limiting valve to satisfy the above-mentioned relation formula, can reduce the HC content in the waste gas effectively under the situation of engine low rotation speed and the little aperture of closure.If Ks and Kv value outside the scope of afore mentioned rules, then can not obtain enough HC reduced rates.
Below in conjunction with accompanying drawing embodiments of the invention are described.
Fig. 1 scooter side view comprises one according to catalytic converter of the present invention;
The outlet pipe part side view of throttle valve is housed in Fig. 2;
Fig. 3 is along the sectional drawing of III-III line among Fig. 2;
Fig. 4 represents near the schematic representation of the structure of motor;
Fig. 5 illustrates the view of ratio K s;
Fig. 6 illustrates the view of ratio K v;
Fig. 7 represents the plotted curve that concerns between Ks value and the HC rate of descent;
Fig. 8 represents the plotted curve that concerns between Kv and the HC rate of descent.
Fig. 1 is the side view of a scooter, and it has one according to catalytic converter of the present invention.Body forward structure 1 is connected with body tail 2 by low base plate 3.The vehicle frame 4 that constitutes body frame extends to following in body forward structure 1, along base plate 3 downsides backward, and upwards rises backward in body tail 2.Vehicle seat 5 is located at the top of body tail 2, comprises that the driving steering head 7 of handlebar 6 is located at the top of body forward structure 1.
Front-wheel 9 is suspended on the body forward structure 1 by front fork 8, and it can be handled by handlebar 6.Carriage 10 is welded in the following rear portion of vehicle frame 4, and extends back.Swing member 12 by connecting rod 11 can around the pivot vertical oscillation be bearing on the carriage 10.Trailing wheel 13 can be rotated to support on the rearward end of swing member 12 by means of car rear axle 14.Rear shock absorber 15 is contained between swing member 12 rear portions and vehicle frame 4 superior posteriors.
The length of outlet pipe 22 is chosen as, and when the high quick-actions of motor 16 are changeed, utilizes the exhaust pulsating energy to prevent that fresh air from sewing.That is because exhaust pulsation in the latter stage of ventilation stroke, produces a positive pressure at relief opening 21 places, this positive pressure can prevent that fresh air from sewing.Point out that in passing in the certain outlet pipe 22 of length, the cycle of exhaust pulsation (in other words, being that the reflected pressure ripple that causes arrives the required time of relief opening 21 because waste gas expands baffler 23 in) has nothing to do with engine speed, it is an individual constant.Otherwise a ventilation needed time of stroke but changes with engine speed.Therefore, when engine speed reduces, just lost the harmonious property between ventilation stroke and exhaust pulsation, thereby, produced a negative pressure at relief opening 21 places in ventilation stroke latter stage.Consequently cause the leakage of fresh air, this just causes unburned HC to enter the phenomenon of waste gas.
In addition, under the less situation of throttle opening, owing to total air inflow that fresh air is original is just smaller, thus make motor lack fire easily, thus non homogeneous combustion caused.Therefore the HC discharge amount in waste gas can further increase.
For addressing the above problem,, establish a flow-limiting valve 24 in the rearward end of outlet pipe 22.So under the less situation of throttle opening, flow-limiting valve has limited the waste gas circulation area, cause a flow resistance to waste gas.Consequently, exhaust gas pressure increases, thereby the negative pressure that stroke relief opening in latter stage 21 places of will taking a breath produce is converted into positive pressure, has avoided the loss of fresh air thus.
Fig. 2 is outlet pipe 22 partial side views that flow-limiting valve is housed, and Fig. 3 is the sectional drawing along III-III line among Fig. 2.Flow-limiting valve 24 comprises a fly valve that is fixed on the axle 25, and fly valve can cross outlet pipe 22 and rotate.The tube wall that one end of axle 25 passes outlet pipe 22 reaches the outside, and pulley 26 is fixed on this overhanging end.A radially outwards outstanding outer extension member 27 is arranged on the pulley.On the other hand, the block 28 and 29 that contacts with outer extension member 27 is located on the outlet pipe 22, for axle, constitutes an angle that is approximately 90 ° between them.Outer extension member 27 is positioned between block 28 and 29.Therefore, pulley 26, axle 25 and flow-limiting valve 24 can be between outer extension member 27 and block 28 position contacting and outer extension member 27 and block 29 position contacting, rotate in being approximately 90 ° scope.
Torsion spring 30 is contained between pulley 26 and the outlet pipe 22.As shown in Figure 2, pulley 26 is under the effect of the power of spring 30 and tend to make outer extension member 27 and block 28 position contacting at one.As shown in Figure 3, under such position, flow-limiting valve 24 is almost perpendicular to the axis of outlet pipe 22.Yet because the outer periphery of flow-limiting valve 24 is less than the internal diameter of outlet pipe 22, outlet pipe 22 is not cut out fully by flow-limiting valve 24, so waste gas can also flow by part vacant between outlet pipe 22 and the flow-limiting valve 24 32.
Cable wire 31 is around pulley 26 excircles, and the termination 31a of cable wire 31 is connected with pulley 26.Therefore, when cable wire 31 along from direction (shown in Fig. 2 arrow a) pull of pulley 26 back-roll the time, pulley 26 approximately rotates 90 °, until outer extension member 27 with till block 29 contacts, so flow-limiting valve 24 this moment along outlet pipe 22 axially, outlet pipe 22 is opened fully.
Fig. 4 schematically illustrates near the structure at the position of above-mentioned motor.From motor 16 and enter the waste gas of outlet pipe 22, in the expansion chamber 33 of baffler 23, expand, then, be discharged into the vehicle body rear side by muffler 34.Cable wire 31 passes A/C 35 (see figure 2)s slidably, extends to the cable wire connection set 36 that is fixed on the vehicle body appropriate location, and is fixed on this cable wire connection set 36.
Cable wire connection set 36 is made up of two pulley 37a and 37b, and these two pulleys rotate together.Cable wire 31 is connected at tie point 31a place with pulley 37a.Pulley 37b is connected with the other end of closure cable wire 38a at tie point 38c, this closure cable wire 38a and the throttle grip (not shown) interlock that is located on the handlebar 6.The other end of this closure cable wire 38a is connected with the end of second closure cable wire 38b at tie point 38d.The other end of this closure cable wire 38b is connected on the closure 39 of above-mentioned Carburetor 18.
When closure cable wire 38a when throttle grip is handled the direction pull of lower edge arrow a, closure cable wire 38b is also drawn along the direction of arrow a, makes closure 39 apertures increase, shown in solid line among the figure.So the rotating speed of motor 16 is increased.But then because pulley 37a and pulley 37b make one, so when closure cable wire 38a pressed the above tension, pulley 37a pressed among the figure and counterclockwise rotates.Consequently, cable wire 31 is drawn (identical with arrow a direction among Fig. 2) along the direction of arrow a, so that rotary pulley 26 is to making outer extension member 27 and block 29 position contacting, so flow-limiting valve 24 is in fully open position, shown in solid line among Fig. 4.Therefore,, can effectively utilize the exhaust pulsation, and therefore help to improve power as designed.
When throttle grip when above-mentioned such state returns, closure cable wire 38a and 38b and cable wire 31 are under the appropriate return spring effect that is provided with, opposite direction along arrow a is slided, and therefore closure 39 is placed a little aperture position, and simultaneously flow-limiting valve 24 is placed the current limliting position.Fig. 4 has dotted these positions.Like this, be at closure under the situation of little aperture, the throttle valve 24 with closure 39 interlocks is limited the exhaust-gas flow area.
Replace above-mentioned cable wire and connect, can establish a throttle sensor that detects throttle opening, flow-limiting valve 24 can be according to the checkout value of sensor, by a servo motor driven.
The inventor has found the following fact, promptly under the situation of the slow-speed of revolution and the little aperture of closure, adopts above-mentioned throttle valve 24 to reduce the effect of HC discharge amount, and is very big with the Ks and the Kv value relation of the following stated.
Ks is the circulation area B (sectional area of waste gas circulation part 32, oblique line part in Fig. 5 (b)) of outlet pipe after the place that flow-limiting valve 24 is housed is by flow-limiting valve 24 current limlitings, and with the ratio of outlet pipe sectional area A (the oblique line part among Fig. 5 (a)), its representation is
Ks＝B/A
Fig. 6 is the schematic representation of outlet pipe 22.The cylinder 40 of motor 16 links to each other with outlet pipe 22, and flow-limiting valve 24 is located among the outlet pipe 22.So shown in the figure bend, the swept volume of supposing cylinder 40 is C (then being the total swept volume of a plurality of cylinders when outlet pipe 22 links to each other with a plurality of cylinders), outlet pipe internal volume from cylinder surface that is relief opening 21 to flow-limiting valve 24 is D, and then the representation of ratio K v is
Kv＝D/C
Get three kinds of motors that are in the idling work state, change the Ks value, and measure the HC content in every kind of engine exhaust.Like this,, can obtain a rate of descent (purification ratio) according to the HC value that records, that is because the percentage of HC amount when the HC reduction amount brought behind the flow-limiting valve 24 being installed and flow-limiting valve 24 not being set.The curve representation of Fig. 7 The above results, abscissa is represented the Ks value among the figure, y coordinate is represented the HC rate of descent.The measurement result of these different motors is expressed as curve E, F and G respectively.In addition, be maximum corresponding to the cylinder swept volume of curve E, corresponding to the cylinder swept volume minimum of curve G.
By Fig. 7 obviously as seen, the HC rate of descent of any motor all depends on the Ks value.In order to obtain 20% or bigger HC rate of descent, the Ks value must be in the 0.02-0.4 scope.
To three kinds of motors that are in the idling work state, change the position of flow-limiting valve 24 in outlet pipe 22, that is change the Kv value, and, obtain the HC rate of descent of every kind of motor by the above identical method.These measurement results of gained are expressed as curve E, F and G in Fig. 8, abscissa is represented the Kv value among the figure, and y coordinate is represented the HC rate of descent.
By Fig. 8 obviously as seen, the HC rate of descent also depends on the Kv value.In order to obtain 20% or bigger HC rate of descent, the Kv value must be in the scope of 1-5.
Therefore, in this embodiment, flow-limiting valve to be designed to, waste gas circulation area B when making flow-limiting valve 24 current limlitings satisfies relation 0.02≤Ks≤0.4 with the ratio Ks of outlet pipe sectional area A, and flow-limiting valve is located at such position, promptly to make from cylinder surface 21 to flow-limiting valve 24 outlet pipe internal volume D and the ratio Kv of cylinder swept volume C satisfy relation 1≤Kv≤5.
In catalytic converter according to the present invention, the flow-limiting valve in the outlet pipe is designed to have the optimum shape size, and is arranged on the optimum position, therefore, can obtain fabulous waste-gas cleaning effect.
Claims (1)
- A kind of catalytic converter that is used for two stroke engine, it comprises single cylinder, single outlet pipe and be located in the outlet pipe flow-limiting valve in order to restriction waste gas circulation area, when hour this flow-limiting valve and closure interlock of throttle opening, it is characterized by: flow-limiting valve is designed to, make the ratio Ks of waste gas circulation area B and outlet pipe sectional area A under flow-limiting valve restriction satisfy relation 0.02≤Ks≤0.4, and flow-limiting valve is arranged on such position, outlet pipe internal volume D between making from the cylinder surface to the flow-limiting valve and the ratio Kv of cylinder swept volume C satisfy relation 1≤Kv≤5.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP257549/92 | 1992-09-02 | ||
| JP4257549 | 1992-09-02 | ||
| JP25754992A JP3148398B2 (en) | 1992-09-02 | 1992-09-02 | Exhaust purification system for two-cycle engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1085983A CN1085983A (en) | 1994-04-27 |
| CN1039846C true CN1039846C (en) | 1998-09-16 |
Family
ID=17307830
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN93108982A Expired - Fee Related CN1039846C (en) | 1992-09-02 | 1993-07-20 | Exhaust gas purifier for two-cycle engine |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP3148398B2 (en) |
| CN (1) | CN1039846C (en) |
| TW (1) | TW217437B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW286341B (en) * | 1993-11-26 | 1996-09-21 | Honda Motor Co Ltd | |
| TW303415B (en) * | 1993-11-26 | 1997-04-21 | Honda Motor Co Ltd | |
| JP4015218B2 (en) * | 1997-02-17 | 2007-11-28 | ヤマハ発動機株式会社 | Scooter type motorcycle |
| CN1076436C (en) * | 1998-01-21 | 2001-12-19 | 干方飞 | Exhaust muffler for internal combustion engine |
| ITUB20160332A1 (en) * | 2016-01-26 | 2017-07-26 | Ansa Tech S R L | PARTIALIZATION VALVE AND DUCT FOR EXHAUST GAS |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0278032A1 (en) * | 1987-02-11 | 1988-08-17 | Yamaha Motor Co., Ltd. | High performance exhaust system for internal combustion engine |
-
1992
- 1992-09-02 JP JP25754992A patent/JP3148398B2/en not_active Expired - Fee Related
-
1993
- 1993-05-13 TW TW082103758A patent/TW217437B/en active
- 1993-07-20 CN CN93108982A patent/CN1039846C/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0278032A1 (en) * | 1987-02-11 | 1988-08-17 | Yamaha Motor Co., Ltd. | High performance exhaust system for internal combustion engine |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1085983A (en) | 1994-04-27 |
| TW217437B (en) | 1993-12-11 |
| JPH0681661A (en) | 1994-03-22 |
| JP3148398B2 (en) | 2001-03-19 |
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| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |