TW200528630A - Motorcycles with two-stroke engines - Google Patents

Abstract

A motorcycle includes a two-stroke engine of crankcase scavenged type including a piston reciprocally mounted in a cylinder, the wall of the cylinder having an exhaust port and at least one transfer port formed in it. The transfer port communicates with the interior of the crankcase via a transfer passage. The transfer port is arranged to open before the exhaust port closes, whereby, in use, the cylinder is scavenged. The engine also includes an inlet duct and a carburettor which is arranged to supply fuel into the inlet duct. The inlet duct is divided into two passages, a rich passage and a lean passage, the rich passage being connected to the interior of the crankcase and the lean passage being connected to the transfer passage. The carburettor includes a throttling valve and is so arranged that, when the valve is closed, fuel flows into both the rich and lean passages and, when the valve is open, substantially all the fuel flows into the rich passage and substantially only air flows through the lean passage.

Description

200528630 V. Description of the invention (1) [Technical field to which the invention belongs] The present invention relates to any locomotive with a two-stroke engine, and not only includes a locomotive with a small engine, such as an engine with a capacity of about 100 cc or less. The locomotive of the CC may further include a larger engine locomotive having an engine capacity greater than 100 cci. More specifically, the present invention relates to an engine having a piston driving a crankcase for scavenging. [Prior art]. In a two-stroke engine that uses a piston to drive the crankcase for scavenging, its cylinder 2 has an intake port, an exhaust port, and an air vent controlled by the piston. The exhaust port is designed to be opened before the vent port is opened and closed after the vent port is closed. Wherein, the ventilation port is substantially composed of one or a plurality of ventilation channels. The ventilation channel is connected to the cylinder and the crankcase, and during the engine cycle, the opening and closing of the downstream end of the ventilation channel is controlled by the piston. This type of engine has a sealed crank, and the crankcase communicates with the cylinder through the ventilation port and communicates with the atmosphere through a tube. When the piston executes the cylinder compression stroke, the curve 5 will suck air or oil-gas mixture through the intake pipe. The air or oil lice mixture will be compressed by the piston in the subsequent working stroke, and with the piston's Continue to move, and the downstream end of the ventilation channel will open accordingly. At this time, the air or oil-gas mixture will enter the cylinder from the ventilation channel. ▲ Only when there is a positive pressure difference between the crankcase and the cylinder, the air gap or gas mixture will enter the cylinder for ventilation. At this time, the air or gas mixture newly entering the cylinder will leave the original residue In the cylinder

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Air or a mixture of oil and gas is swept out of the exhaust port. During the implementation of this steam red ^, it is inevitable that the air or oil-gas mixture newly entering the cylinder will have one: as the air or oil-gas mixture originally remaining in the cylinder is discharged together from the exhaust port, causing some loss, and this This type of loss is often called scavenge losses. In the bow cycle of each cycle, this scavenging loss phenomenon also occurs during the closing of the ventilation port and the closing of the exhaust port. This period is generally known as the trapping period (trapping period). ) / And the losses that occur during this stay are usually called trapping losses. 〇 Two-stroke engines are mostly installed on small locomotives, such as light-duty locomotives of other types, or other small two- or three-wheeled small locomotives. vehicle. In envy, this type of locomotive engine is provided with a carburetor / to determine how much fuel is supplied into the intake pipe according to the air flow rate. This means that all the oil and gas mixture entering the crankcase and then into the cylinder is originally a mixture of air and fuel. This means that the gas flowing out of the exhaust port also contains fuel with the scavenging, which makes the two-stroke engine's incomplete combustion of hydrocarbon emissions relatively high. Today, two-stroke locomotive engines are facing stringent exhaust control regulations and durability requirements. It is expected that many countries will formulate stricter regulations for such small engines to control their exhaust emissions. These regulations will not only Restricting emissions of incompletely burned hydrocarbons (HC) and monoxide (c0) will also limit emissions of particulate matter. At present, without the use of emission control equipment such as oxidation catalysts, there is no more effective small two-stroke engine that can meet such requirements.

Page 8 200528630 V. Description of Invention (3) '' Regulations. Therefore, engine manufacturers must use catalysts anyway, or use other potentially expensive emission control equipment, or seek a low-cost solution. Therefore, if after the development of other technologies that can reduce emissions, there is still a need to use catalysts, then, in order to reduce the cost and cost of ^ ^, and to reduce the exhaust temperature and improve the catalyst to treat the combustion Incomplete hydrocarbon catalyst

I should be minimized. It can be seen from the monitoring results of the actual operation of the Da Lin 2 2 3 locomotive that the throttle valve of the engine is not at or close to the no-load and no-load ΐ ^, when it is at or close to full-load operation Fully open. In any case: 'The fuel content of the oil and gas mixture flowing into the engine will be relatively reduced. This means that the fuel in the actual scavenging loss contains a high amount of oil and gas mixture flowing into the engine, and it will be so high, ^ Second, the loss of scavenging gas will also change. In addition, the degree of unacceptability based on environmental protection factors. CharglngC intake method (stratified). However, due to this type of maximum operating efficiency when the engine is running at full load, it should be introduced. Quotation "; u is the problem of mixing fuel and air with the same mass. Fuel and air are inadequate. When the engine is running at no load, the actual effect will be caused. Insufficient (inadequate mixing ratio) causes unsure mass: ί; Manufactured to be the same as air during low-load operation, so that when fuel is introduced in layers at 5 | Note (4) Partially scavenging to reduce the scavenging loss is disclosed in the related content disclosed in WO 99/58829 patent case. It is understood that-a small type of portable device such as a chain saw :: 程The engine's intake pipe system is divided into a high-concentration channel and ": thick two and communicates with a carburetor. The carburetor is in the two-stroke engine: the material is fed into the high-concentration channel and the same θ low / chen Degree channel, and when the two-stroke engine is running at low load, the degree of air mixture is supplied into the high-concentration channel and the low-concentration more air channels respectively. These spaces are channeled due to different applications. The low-concentration space is also connected to the high-concentration curve. The mysterious low / chen degree channel is connected. Among them, the high-concentration space is more connected to a word = ventilation channel, and the high-concentration ventilation channel is connected by an engine: The combustion chamber is connected, and the air port is located at the exhaust port ;;: Acoustic two low-roller space is connected with a low-concentration ventilation channel, and the low-concentration channel is connected to the two through one or more air ports Stroke engine combustion. Jian, and the port is located near the exhaust port Therefore, during the high-load operation of the two-line engine, when the piston performs a compression stroke, fuel and air are sucked into the crankcase, so that the high-concentration space is filled with a high-concentration plug ^ complex, and the low-concentration space It is filled with clean air. When the worker hits the working stroke and works in the opposite direction, the exhaust port will be cleaned 1i first, and then the port is connected to the low-concentration ventilation channel. At this time, dry , Two = will remove the remaining oil and gas mixture remaining in the combustion chamber of the two-stroke engine, and the air port communicating with the high-concentration ventilation channel will also be opened, so that

200528630 V. Description of the invention (5) The oil and gas mixture enters the combustion space, and will not be completely mixed with the clean air phase.

The two-stroke bow engine disclosed in the previous case is quite useful, because it not only automatically mixes fuel and air with mass during low load operation, but also introduces fuel by stratified air intake during high load operation. And air. In addition, the engine uses clean air for scavenging. Therefore, during the scavenging process, only a small amount of fuel will be burned. The incompletely burned fuel is discharged into the atmosphere, or even the incompletely burned fuel is not emitted at all. Be discharged. However, because the engine system disclosed in the previous case needs to divide the interior of the crankcase into a high-concentration space and a low-concentration space, and the crankcase needs to use a bulkhead and a complicated structure sealing ring; therefore, the previous case not only has Disadvantages of manufacturing and the increase of manufacturing costs are caused by the fact that these high-concentration and low-concentration spaces cannot be reliably sealed, so that during the scavenging, not only the clean air will be exhausted, but also some of the incompletely burned fuel will be exhausted Cause scavenging losses. SUMMARY OF THE INVENTION The object of the present invention is to provide a locomotive with a two-stroke engine, and the two-stroke engine not only has the advantages of the above-mentioned engine, but also can solve its disadvantages. More specifically, the locomotive has a two-stroke engine that uses a crankcase for scavenging. The two-stroke engine includes a crankcase, a piston, and a cylinder. The piston is installed in the cylinder in a reciprocating manner. The inner wall of the cylinder has an exhaust port and at least one ventilation port. The ventilation port communicates with the interior of the crankcase through a ventilation channel. And the vent

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It is arranged to be opened before the exhaust port is closed for purging the cylinder. In addition, the three- and two-stroke engines further include an intake pipe and a carburetor for supplying fuel to the intake officer. The intake pipe system is divided into a high-concentration channel and a low-concentration channel. The channel system is in communication with the interior of the crankcase, and the low concentration channel is in communication with the ventilation channel. The carburetor system has a throttle valve, and when the throttle valve is closed, the fuel system flows into the high-concentration channel and the low-concentration channel, and conversely, when the throttle valve is opened, the fuel system all flows into the high-concentration channel. And only air flows through the low-concentration channel.

Although the two-stroke engine used in the locomotive of the present invention is similar to the engine disclosed above, for example, the carburetor is of the type disclosed in the previous case, and the intake pipe is also divided into two channels. However, as described above, the high-concentration channel and the low-concentration channel of the previous case communicate with the interior of the crankcase, and it is necessary to use a partition to form a high-concentration space and a low-concentration space. However, the two-stroke engine used in the locomotive of the present invention only needs to communicate the high-concentration channel with the interior of the crankcase. This means that the crankcase no longer needs to be partitioned into a plurality of sealed spaces; and the engine works During the intake phase of the cycle, the low-concentration channel will communicate with the ventilation channel at a specific stage, that is, when air and fuel are introduced into the crankcase, the engine is under high load operation. The oil and gas mixture is caused to flow in from the high-concentration channel, and clean air is caused to flow into and pass through the ventilation channel substantially from the low-concentration channel. Therefore, after the engine completes the intake phase, the interior of the crankcase will be filled with a mixture of oil and gas, and the ventilation passage will be filled with clean air. In addition, when the engine starts scavenging, the clean air in the ventilation channel first flows into the cylinder and sweeps the remaining oil and gas mixture. As a result, only a small amount of incomplete combustion

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V. Description of the invention (7) 1 ”is discharged into the atmosphere, or there is no emission of incomplete combustion materials. Therefore, after the air flows into the cylinder, most of the air is discharged from the breast discharge port. The air-fuel mixture that fills the crankcase enters the cylinder, so that the intake air of the cylinder is stratified; therefore, the locomotive bow jg of the present invention not only has the advantages of the foregoing case, but also can be easily manufactured and the manufacturing cost can be reduced.

In addition, the period of time when the engine generates negative pressure during intake and when table f is generated during scavenging will cause pressure fluctuations in the crankcase. To avoid the crankcase pressure being gauge pressure, air will The high-concentration channel communicates with the inside of the crankcase, and flows back from the crankcase to the high-concentration channel from the intake port; therefore, the intake pipe of the engine must be provided with a check valve such as a spring valve. To avoid air backflow. Therefore, if the engine can use the piston in the cylinder and control the opening and closing of the air inlet during repeated movements, the need to use a check valve such as a spring valve can be eliminated. In view of this, in a preferred embodiment of the present invention, a circumferential wall of the piston is formed with a groove, and the interior of the crankcase communicates with the air inlet through cooperation with the air inlet. At the dead point, the southern trace channel can communicate with the interior of the crankcase via the groove.

As mentioned above, when the low-concentration channel is in communication with the ventilation channel, and the pressure in the curved suction box is a gauge pressure, the gas is thereby discharged from the ventilation channel: the intake pipe must also be added to stop Return valve; therefore, the same need to eliminate the need for non-return valves such as common valve; in the preferred embodiment described above, the low / agricultural channel is through a side port on the inner wall of the steam rainbow and the The notch of the circumferential wall of the piston is in communication with the ventilation channel. When the piston is near the top dead center, the notch is connected to the ventilation channel and the side port; therefore, the present invention

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V. Description of the invention (8) Different air ports to ensure that the low-concentration channel communicates with the ventilation channel only when the pressure in the crankcase is negative, and air flows into the crankshaft through the ventilation channel The 'piston' blocks the communication with the ventilation channel at other stages; therefore, the piston system can replace the function of the aforementioned valve, so that no additional valve is required for the intake pipe. In addition, during the scavenging process, in order to further reduce any fuel being discharged to the atmosphere, in terms of the air inlet and the air outlet setting, the air inlet should be located opposite the air outlet That is, the air inlet and the air outlet are arranged around the cylinder at an angle of 180 degrees from each other. Furthermore, the locomotive engine of the present invention can not only have a single ventilation channel and a ventilation port, but also a locomotive engine with two ventilation ports, and the two ventilation ports are respectively communicated with the two ventilation channels. One of the ventilation ports is opposite to the other ventilation port, and is 90 degrees to the exhaust port and the air intake port. [Embodiment] Other features and details of the present invention are shown in the following preferred embodiments and related drawings. ^ The main structure of a general locomotive consists of a main body with a section for the driver to ride on, a control front wheel and a driving rear wheel. The driving rear wheel train is connected to an engine with a capacity of 50cc to 100 by a transmission system device. 〇〇 The output of a small two-stroke engine; the transmission system may include a manual clutch and a manual transmission, or a transmission system including a centrifugal clutch and a stepless automatic transmission (CVT), that is, One according to different

200528630 V. Description of the invention (9) Automatically refer to the first figure to the first cylinder (4) using the gear ratio, the cylinder head (6), and the cylinder; among them, the cylinder (4) and an exhaust pipe (16) and the vent (1 8) are respectively a piston (2), in the system; and a crankcase (14) and the axle box (1 4) are connected by the side wall of the port, (2 2)). 2) located in the special (1 8) with all the axle box (1 4) such as the fourth carburetor (3 0 compartment (3 2 lanes (3 4)) the carburetor () is provided with a rod (1 0) the The two ventilation passages communicate with the crankcase when the crankcase has two movable positions; in addition, or the groove (2) is shown in the internal connection diagram, the) is connected, and) is separated into one; Transmission system. In the fourth figure, the two-row engine of the present invention includes: a spark plug (8) is provided in a steam cap (6) for closing the cylinder (4), and an exhaust port (1 5) is provided on the inner wall; The two ventilation ports (18) communicate with each other, and the two communicate with the two ventilation channels (20); the cylinder (4) is reciprocally movable, and is integrated with the cylinder integrally, and the crankshaft (1 2) •, wherein the piston (2 is combined with the crankshaft (1 2). The channels (20) are each communicated through the interior of the two crankcases (14), and the piston (2 plug or notch ( 24), when the piston (the two notches (2 4) will be tied to a corner of the side wall of the piston (2) of the ventilation port and further 6), and the groove (2 6) is the Qu 0 engine By means of an air inlet pipe (2 8) and a chemical tube, the air inlet pipe (2 8) is longitudinally covered by a high-concentration channel (3 _ 6) and a low-concentration universal WO 9 9/58829 patent case has been revealed Relevant structure and operation method, will not be described in detail here

Page 15 200528630 V. Description of the invention (10), but in short, it is used to rotate to a first position 38) when it is turned to the first position, and when the throttle valve (3 state And completely close one of the partitions (40 the carburetor, the throttle valve (8), and then extend the continuation section. Then in the 4th stroke, enter the circular channel (3 mixture (38 holes, the time nozzle) Channel (air. ≫ —— engine is on, burn high concentration and enter 6) and. In addition) turn all (44 3 6) groove at a dead point (please refer to a crankcase, the song 2 6) ) Is the entrant, the petrol injection port (4 when no-load operation (4 8) channel (3 6 the low concentration pass through the low concentration pass, when the two lines to the second fuel (4 8) And full-load spray: Therefore, the third picture, the inlet (5 axle box inlet and the crankcase (30 and 1, then the 3 8) into the compartment (trachea (3 4) and, This section is from the), and the combination (3 channels (3-way engine set, and)) includes a second position from π (4 low concentration), the intake pipe (2 Rotate to the 2nd of the intake pipe (2 4 0) 2 8) Inner compartment 0) includes a full-flow valve without load at the same time 4) 4) Close the full without the 6) channel-carrying nozzle (38 nozzle (through the ; Therefore, all have the nozzle of the compartment running and the (34 flow valve (when the section 8), the two position 8) pipe round hole; the section (3 one without load (46) turn 4 2) the partition ( A thin, and the (40 (42 into the) only contains 3 8) the flow valve (when fully completed, when the length is parallel to it, 2) the nozzle (); the movement to the ejection and 4 0) the concentration of oil and gas Throttle valve) circle), the terminal line of the high-concentration channel (3 6) with clean central and southern concentration is 0), when the piston (2) is close to the upper (50), the piston (2) 1 4) internal communication; and the low concentration

Page 16 200528630 V. Description of the invention (11) Channel (3 4 channel (5 2) port (5 4) (5 4) So, move up and make the piston 50 0), the mixture can be removed from the crankshaft The side of the box (5 4 and the ventilation ports (34), (1 8) and: the crankcase channel (2 0) moves with the downward movement of the inlet (50 and closes the curve when moving down, 2 0 ) Inside the cylinder (4 to the atmosphere.) At the end of the connection, when the two lines are dead (2) and the intake air 14)) and (18 through the ventilation channel (14) Full of two strokes to the bottom of death), the side axle box (then pressurized air,) must never be inside, the two side pass systems are respectively located at the piston (the two notch range engine is at the point, so that the groove (inlet ( 5 tube (2 8 inside; communicate with the vent (), and the side port (5 (20)) thus fills the holding point of a clean empty engine, the π (5 4 1 4) is retracted at the subsequent opening Most of the time when the piston path (5 to the steam 2) is nearly (24 full loaded crankcase 2 6) 0) and even), the 18) to dry 4),) is full of oil and gas. Continued Running piston ) And the replacement part; and when the crankcase opens the exhaust body from the (2) 2) phase cylinder (4 to the upper dead), the (14 moves to the passage, and the concentration passes the notch (, and the clean air notch) (When the curved gas is mixed and communicated, when the inner point of the wall, the piston) the internal crankcase makes the high-density channel (3 2 4) the side port is from the lower 2 4) the axle box (object, and the two sides communicate) On both sides, the ports on the two sides (2 with a negative air intake of 6) are shifted (5 concentration, changed to 14 changed), and the pressure in the port (oil and gas flows to the 4) channel port is under the air flow, when The work 2) blocks the air port (18), while the piston (2 (1.4)) and the air vent (1 5), the exhaust pipe (1 further operates the plug (2), the crankcase leads to communication,) Continue down the air channel (, while making 6), and

Page 17 200528630 V. Description of the invention (12) Open the ventilation port (1 8) and allow the compressed air in the ventilation channel (20) and the crankcase (1 4) to flow into the cylinder (4) ); Therefore, the inflowing air removes or sweeps the original residual gas, and causes the residual gas to flow out of the exhaust pipe (16), and in fact, a part of the gas used to expel the residual gas follows the residual gas Exhaust; therefore, in general, since the air system in the ventilation channel (20) for purging the residual gas is clean air, during the exhaust process, only clean air is exhausted without any loss. fuel. In addition, under the low-load operation of the two-stroke engine, the high-concentration channel (36) and the low-concentration channel (34) both contain a thin mixture of oil and gas 4 and the thin mixture of oil and gas is used for scavenging. As a result, a small amount of fuel is discharged into the atmosphere; because the fuel contained in the discharged oil'-gas mixture is relatively scarce, it is sufficient to show that the retention efficiency of the two-stroke engine of the present invention is quite high. As a result, the same or similar technical disclosure has not been previously disclosed in similar products of the present invention, so it has met the requirements for invention patents and filed an application in accordance with the law.

Page 18 200528630 Brief description of the drawings [Simplified description of the drawings] The first diagram is a schematic side view of the locomotive engine of the present invention, which shows that the piston is near the top dead center. The second figure is a schematic side view of the locomotive engine of the present invention, which shows that the piston is near the bottom dead center. The third figure is a schematic sectional view of a locomotive engine according to the present invention. The fourth figure shows the carburetor of the locomotive engine with a throttle valve in a low-load or no-load position. [Illustration of drawing number] Connecting rod (10) Crankcase (1 4) Exhaust pipe (1 6) Piston (2) Crankcase opening (2 2) Groove (2 6) Carburetor (3 0) Low concentration Channel (3 4) Throttle valve (3 8) Partition (40) Intermediate nozzle (4 4) Fuel (4 8) Side channel (5 2) Cylinder head (6) Crankshaft (1 2) Exhaust port (1 5) Vent (1 8) Vent (2 0) Vent (2 4) Intake pipe (2 8) Partition (3 2) High-concentration channel (3 6) Cylinder (4) No-load nozzle ( 4 2) Full-load nozzle (4 6) Crankcase inlet (5 0) Side port (5 4) Mars plug (8)

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Claims (1)

200528630 6. The scope of the patent application and the stroke crankshaft-cylinder port is arranged to scavenge through the port; this type of locomotive has a crankcase scavenging-type two-stroke engine. The engine includes: 々Λτ · phase, whose inner wall has a row An air port and at least one air vent, the air vent channel is in communication with the interior of the crankcase, and the air vent is opened before the exhaust port is closed, and is used to perform a piston-intake to the cylinder; and the The Nannong system and the ventilating 4 dagger oil have a throttle concentration channel and the part flows into the high 2. The degree channel excuse is located on the energy, it can go to the tube, the channel is the channel connector, and the valve is used. When the low-concentration concentration channel is applied for a patent, an introduction port is provided in the cylinder by the piston; the high-concentration channel is divided into a low-concentration channel and the low-concentration channel communicates with the interior of the crankcase; the low-concentration channel; When the fuel reaches the intake pipe and the carburetor throttle valve is closed, the fuel system flows into the high channel respectively. When the throttle valve is opened, the fuel system is full and only air flows through Low-concentration channel. The locomotive according to item 1 in the scope, wherein the high-density is in communication with the interior of the crankcase, and the introduction is in a position where it is opened and closed during reciprocating movements 3. The locomotive according to item 2 in the scope of patent application, where A groove is formed on the circumferential wall of the piston, and the groove communicates with the interior of the crankcase by the cooperation of the introduction port, and when the piston is near its top dead center, the high-concentration channel can pass through the groove. It communicates with the interior of the crankcase. 4. The locomotive as described in any one of claims 1 to 3, Page 20 200528630 VI. The scope of the patent application The low-concentration channel communicates with the ventilation channel through a side port located on the inner wall of the cylinder and a notch located on the circumferential wall of the piston. When the piston approaches At the dead point, the notch is connected to the ventilation port and the side port. 5. The locomotive according to any one of claims 1 to 4, wherein the introduction port is located opposite the exhaust port. 6. The locomotive as described in item 5 of the scope of the patent application, wherein the two-stroke engine has two ventilation ports, and the two ventilation ports each communicate with a ventilation channel, and one of the ventilation ports is located at the other. Opposite the port. Page 21