JP3765335B2 - 2-cycle internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a two-cycle internal combustion engine that prevents the air-fuel mixture in the combustion chamber from being blown through and improves fuel consumption and exhaust purification performance.
[0002]
[Prior art]
In a conventional two-cycle internal combustion engine, fuel supplied by a carburetor or the like is mixed with intake air, and after this mixture is sucked into the crank chamber, it is supplied to the combustion chamber through a scavenging opening and the exhaust opening is opened. Since the timing is set earlier than the opening timing of the scavenging opening (the upper edge of the exhaust opening is higher than the upper edge of the scavenging opening), the air-fuel mixture supplied into the combustion chamber is discharged into the exhaust passage, so-called A colonnade was easy to occur.
[0003]
Although this blow-through is suppressed by the exhaust pulsation effect of the exhaust chamber, it is difficult to suppress over the entire operation range, and as a result, the fuel consumption and the exhaust purification performance are affected.
[0004]
As a solution to this problem, there have been two-cycle internal combustion engines disclosed in Japanese Patent Laid-Open Nos. 3-100318 and 5-302521.
[0005]
In a two-cycle internal combustion engine described in JP-A-3-100318, a high pressure chamber is connected to a crank chamber via a check valve, and the high pressure chamber and the combustion chamber are connected by an air passage. A solenoid valve is disposed at the lower end of the air passage, and a fuel injection valve capable of injecting fuel toward the combustion chamber is provided at the upper end of the air passage.
[0006]
Further, in the two-cycle internal combustion engine described in JP-A-5-302521, a chamber is disposed adjacent to the crankcase and the cylinder block, and an intake control valve is interposed between the crank chamber and the chamber. In addition, a scavenging control valve is interposed between the chamber and the combustion chamber of the cylinder, and a fuel injection valve for injecting fuel into the chamber is provided.
[0007]
[Problems to be solved]
In the two-cycle internal combustion engine disclosed in Japanese Patent Laid-Open No. 3-100318, the fuel adhering to the air passage among the fuel injected from the fuel injection valve falls due to gravity and is cranked via the check valve at the bottom of the air passage. Since it enters the chamber and flows from the crank chamber through the other scavenging openings without being atomized, the blow-through is not sufficiently prevented, and it is difficult to cause stable combustion and fuel into the combustion chamber. There is a problem that the responsiveness is not good because the supply amount is not properly controlled.
[0008]
Further, in the two-cycle internal combustion engine disclosed in JP-A-5-302521, all the intake air in the crank chamber is introduced into the chamber through the intake control valve, and mixed with the fuel injected into the chamber from the fuel injection valve, Since all the air flows into the combustion chamber through the scavenging control valve and only air from the crank chamber can not flow into the combustion chamber through the scavenging opening, blow-by is unavoidable, and upstream of the scavenging control valve. Although the opening is open at the bottom of the chamber, but not at the bottom, the fuel injected into the chamber accumulates at the bottom of the chamber, and the amount of fuel supplied into the combustion chamber cannot accurately correspond to the amount of fuel injected. There is also a drawback that the response is not good.
[0009]
[Means for solving the problems and effects]
The invention of the present application relates to an improvement of a two-cycle internal combustion engine that has overcome such difficulties, and the invention described in claim 1 is provided in the communication path between the combustion chamber and the chamber connected to the fuel injection device. In a two-cycle internal combustion engine that arranges a control valve that controls the passage so that it can be freely opened and closed, and that supplies fuel to the combustion chamber via the communication passage, the chamber is disposed on the side of the combustion chamber, and At least a control part of the control valve is provided below the connection part with the chamber, a scavenging passage for supplying only the air in the crank chamber to the combustion chamber is provided, and a fuel in the communication passage is provided. Baked A communication opening that opens into the room is located above the control valve. The communication path includes a first communication path through which highly compressed air flows from the combustion chamber to the chamber and a second communication path through which air-fuel mixture flows from the chamber to the combustion chamber, and the control valve includes the first communication path. A first control valve provided in the communication passage and a second control valve provided in the second communication passage and having the control unit, the first control valve being in the vicinity of the first communication valve when the exhaust opening is closed. The passage is communicated and the first communication passage is closed during the compression stroke, and the second control valve communicates the second communication passage when the scavenging opening is closed, and the first communication passage during the compression stroke. The second communication passage is closed before the passage is closed. This is a two-cycle internal combustion engine.
[0010]
Since the invention described in claim 1 supplies fuel to the combustion chamber via the communication path as described above, scavenging line As a result, air containing no fuel can be introduced into the combustion chamber through the scavenging passage, and the burned gas in the combustion chamber can be reliably discharged from the exhaust opening. In addition, the scavenging efficiency by air scavenging can be improved at low load.
[0011]
In addition, at least the control unit of the control valve, Said Provided below the area connected to the chamber In addition, since the communication opening that opens into the combustion chamber of the communication passage is located above the control valve, even if the fuel supplied from the fuel supply device into the chamber is the bottom of the chamber or the chamber and the chamber Combustion chamber Even if there is a case where it accumulates in the lower part of the communication passage communicating with the control valve, etc., the stagnant fuel can be surely discharged into the combustion chamber by vigorous fuel flow by intermittent opening and closing of the control valve. As a result, the control of the fuel supply amount into the combustion chamber is appropriately performed with good responsiveness, and a stable combustion state can be obtained.
[0012]
Furthermore, as described above, since the chamber is disposed on the side of the combustion chamber, the entire engine can be combined into a condensed shape having a substantially square shape when viewed from the side. The length of the entire engine can be shortened. As a result, when the engine is mounted on various vehicles, the degree of freedom in layout increases. In particular, when the engine is mounted on a motorcycle, there is no problem that the vehicle height and the minimum ground height increase.
[0018]
further The Since the chamber can be filled with air, the high pressure in the combustion chamber can be used, so that a higher chamber pressure can be obtained more reliably and stably than the filling with the pressure in the crank chamber.
[0019]
In addition, the air-fuel mixture obtained by filling the chamber with air becomes a rich air-fuel mixture, which flows into the combustion chamber sufficiently scavenged by air that does not contain fuel that has passed through other scavenging passages. The air-fuel mixture has an appropriate concentration in the room, and good combustion can be obtained, so that a high level of fuel consumption and high exhaust purification performance can be achieved.
[0020]
In addition, since highly compressed air for producing the rich air-fuel mixture is obtained from the combustion chamber, a control valve disposed in a communication passage that communicates the chamber and the combustion chamber is provided on the cylinder wall near the combustion chamber. As a result, the length of the communication path between the control valve and the mixture injection opening can be shortened, and accordingly, the fuel is required to move through the communication path. The amount of carrier gas (air) can be reduced.
[0021]
In addition, the opening timing of the control valve must be set in consideration of the time required for the fuel to move through the communication passage. Therefore, the higher the rotation speed, the faster the opening timing needs to be set. However, as described above, since the communication path length between the control valve and the mixture injection opening can be shortened, the time required for the fuel to move through the communication path is shortened, and the factor of the time Has a smaller influence on the setting of the opening timing of the control valve. As a result, the opening timing of the control valve can be easily set, and the set opening timing of the control valve can easily be adapted over a wide rotational speed range.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Less than, Embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 to FIG. See ,Book Request Light The fruit Form Having a part in common with a part of (Less than, Basics This is called an embodiment. ).
The spark ignition type two-cycle internal combustion engine 1 of the present invention is mounted on a motorcycle (not shown). In the spark ignition type two cycle internal combustion engine 1, a cylinder block 3 and a cylinder head 4 are sequentially placed above a crankcase 2. They are stacked and joined together.
A piston 6 is slidably fitted up and down in a cylinder hole 5 formed in the cylinder block 3, and the piston 6 and the crankshaft 8 are connected to each other by a connecting rod 7. As a result, the crankshaft 8 is driven to rotate.
[0024]
Further, an intake passage 10 directed from the rear to the front of the vehicle body is connected to the intake passage 10 of the crankcase 2, and a throttle valve 11 and a reed valve 12 are interposed in series in the intake passage 10. The throttle valve 11 is connected to a throttle grip (not shown) via a connecting means that is not provided, and the opening of the throttle valve 11 increases when the throttle grip is twisted in one direction.
[0025]
Furthermore, the crankcase 2 and the cylinder block 3 are formed with four air supply scavenging passages 14 and 15 in total, two on the left and two on the left, which communicate the upper part of the cylinder hole 5 with the crank chamber 9. A rich mixture supply scavenging passage 18 is formed at a position closer to the rear than the scavenging openings 16 and 17 of the air supply scavenging passages 14 and 15, and the scavenging passage 18 is higher. The passage 18 extends downward from the scavenging opening 19 toward the intake passage 10 and is opened to the valve housing hole 20 of the crankcase 2 parallel to the crankshaft 8. The exhaust opening 22 on the cylinder hole 5 side of the exhaust passage 21 is the scavenging opening. It is placed at the position opposite to 19.
[0026]
Moreover, the substantially hemispherical combustion chamber 13 above the cylinder hole 5 is offset toward the exhaust opening 22, and a spark plug 23 is disposed in the combustion chamber 13.
[0027]
An air passage 24 is formed in the cylinder block 3 at a position directly above the intake passage 10, and the intake passage bypasses the outer periphery of the cylinder hole 5 on the lower surface of the cylinder block 3 that contacts the crankcase 2. An air introduction groove 25 communicating the air supply scavenging passage 14 and the air passage 24 closer to 10 is formed, and a reed valve 26 serving as a crank chamber side control valve is provided above the air passage 24. A partition wall 27 is formed on the side of the combustion chamber 13 of the cylinder block 3 so as to surround it, and a lid 28 is detachably attached to the opening edge of the partition wall 27, and the partition wall 27 and the lid 28 constitute a chamber 29. .
[0028]
Further, the cylinder block 3 is formed with air passages 30 oriented in the vertical direction on the left and right sides of the air passage 24. The crankcase 2 communicates with the lower end of the air passage 30 at both the left and right ends and a communication hole at the center portion. A mixing chamber 31 is formed in communication with the valve housing hole 20, and a rotary valve 33 as a combustion chamber side control valve is rotatably fitted in the valve storage hole 20. The rotary valve 33 has a central portion in the longitudinal direction thereof. And a fuel introduction passage 35 communicating with the valve chamber 34 from the left end of the rotary valve 33 is formed in the same direction as the crankshaft 8 (reverse to FIGS. 1 and 4). (Clockwise) at the same rotational speed.
[0029]
Furthermore, a fuel injection valve mounting hole 36 is formed in the crankcase 2 from the rear of the vehicle body toward the mixing chamber 31, and the fuel injection valve 37 is mounted in the fuel injection valve mounting hole 36. A fuel injection valve mounting hole 38 that communicates with the fuel introduction passage 35 from the left side of the fuel injection passage 35 is formed, and the fuel injection valve 39 is mounted in the fuel injection valve mounting hole 38.
[0030]
Further, as shown in FIG. 6, an exhaust control valve 40 is provided near the exhaust opening 22 of the exhaust passage 21, and the exhaust control valve 40 is a recess 41 having an arcuate cross section formed in the cylinder block 3. And an exhaust passage member 42 formed in substantially the same vertical cross-sectional shape as the concave portion 41 and fitted in a gap 43 having substantially the same interval width, and integrally coupled to the exhaust passage member 42 A base of the exhaust control valve 40 is integrally mounted on a rotary shaft 45 rotatably supported by an exhaust pipe mounting member 44, and the rotary shaft 45 is connected to an exhaust control servo motor (not shown), The exhaust control servomotor is controlled by a control signal output from a CPU (not shown) based on an exhaust opening ratio map having the opening of the throttle valve 11 and the rotational speed of the spark ignition type two-cycle internal combustion engine 1 as independent variables. Optimal exhaust that works and adapts to operating conditions The exhaust control valve 40 is swung so as to have an opening ratio.
[0031]
Further, as shown in FIGS. 3 and 11, the crankcase 2 is divided into a left crankcase 21 and a right crankcase 2 r with a split surface 46 as a boundary, and is positioned behind the crankshaft 8. The main shaft 47 and the counter shaft 48 are pivotally supported by the left crankcase 2l and the right crankcase 2r, and the main shaft 47 is provided with a clutch 49, and the main shaft 47 and the counter shaft 48 are provided with transmission gears. The group 50 is provided, the driven gear 52 of the clutch 49 is meshed with the drive gear 51 at the right end of the crankshaft 8, and the chain sprocket 53 is integrally attached to the left end of the countershaft 48. When an endless chain is stretched over the chain sprocket of the wheel, the spark ignition type two-cycle internal combustion engine 1 is in an operating state, and the clutch 49 is set in a connected state, the crankshaft 8 Rotational force drive gear 51, driven gear 52, clutch 49, is transmitted to the chain sprocket 53 via the speed change gear group 50 and the counter shaft 48, the rear wheels are driven to rotate.
[0032]
Furthermore, a balancer weight 54, which is positioned above and obliquely above the crankshaft 8 and cancels the primary inertial force of the crankshaft 8, is rotatably supported by the left crankcase 21 and the right crankcase 2r. In the drawing of the balancer weight 54, a balancer gear 55 is integrally mounted at the right end, and a driven gear 56 is integrally mounted on the right side of the rotary valve 33, and the drive gear 57 and the balancer gear 55 of the crankshaft 8 are driven. When the crankshaft 8 rotates, the balancer weight 54 rotates in the opposite direction to the crankshaft 8, and the rotary valve 33 rotates in the same direction as the crankshaft 8 at the same rotational speed as the crankshaft 8. It is designed to be driven.
[0033]
In addition, a drive gear 58 is fitted to the right end of the rotary valve 33, and a plunger type oil pump 59 is disposed adjacent to the right side of the rotary valve 33, and a driven gear integral with the drive shaft 60 of the oil pump 59 is provided. An intermediate gear 62 is meshed with 61 and the drive gear 58, and when the crankshaft 8 rotates and the rotary valve 33 is driven to rotate, the oil pump 59 is driven.
[0034]
Oil from the oil pump 59 is supplied to the bearing portion of the crankshaft 8 via an oil supply path 63 (see FIG. 2), and to the cylinder hole 5 via an oil supply path 64 (see FIG. 10). It is supplied to the sliding part with the piston 6.
[0035]
Further, as shown in FIG. 2, a driven gear 67 integral with the rotary shaft 66 of the water pump 65 is meshed with the drive gear 51 at the right end of the crankshaft 8, so that the spark ignition type two-cycle internal combustion engine 1 is operated. When the state is reached, the water pump 65 is driven to rotate, and the cooling water in the spark ignition type two-cycle internal combustion engine 1 is sent to a radiator (not shown) to be cooled, and then the cooling water passage 68 of the spark ignition type two cycle internal combustion engine 1. It comes back in again.
[0036]
Since the illustrated spark ignition type two-cycle internal combustion engine 1 is configured as described above, when the crankshaft 8 is driven to rotate counterclockwise in FIGS. 12 to 15 by a starter motor (not shown), the top dead center. (TDC) At 75 ° before the scavenging opening 19 of the rich mixture supply scavenging passage 18 is closed by the piston 6, the combustion chamber 13 is compressed, and the ignition plug 23 is turned on at a predetermined timing before top dead center. The crank chamber 9 continues to expand as the piston 6 rises and the intake continues (see FIG. 12).
[0037]
Then, after reaching the top dead center (TDC), as shown in FIG. 13, the air-fuel mixture in the combustion chamber 13 is combusted and expanded, and the crank chamber 9 is compressed by the lowering of the piston 6, and the crank chamber 9 is compressed. The air in the chamber 9 is compressed.
[0038]
Further, when 90 ° has elapsed from the top dead center (TDC) (which fluctuates depending on the vertical position of the exhaust control valve 40), the exhaust opening 22 is opened, and the combustion gas is discharged from the exhaust passage 21. From almost this time, the compressed air in the crank chamber 9 flows into the air passage 24 from the air supply scavenging passage 14 near the intake passage 10 through the air introduction groove 25, and enters the air passage 24. To the chamber 29 through the reed valve 26.
[0039]
Further, when about 122 ° has elapsed from the top dead center (TDC), the scavenging openings 16 and 17 are opened by the lowering of the piston 6, and the air (not including fuel) in the crank chamber 9 is scavenged for air supply. The gas flows into the combustion chamber 13 from the scavenging openings 16 and 17 through the passages 14 and 15, the burned gas in the combustion chamber 13 is pushed out toward the exhaust opening 22, and scavenging with only air is performed. At the same time, fuel is injected into the mixing chamber 31 from the fuel injection valve 37 and the fuel injection valve 39, and a rich mixture is generated (see FIG. 14).
[0040]
Next, when about 58 ° has elapsed from the bottom dead center (BDC), the scavenging openings 16 and 17 are closed by the rising of the piston 6, and scavenging due to the inflow of air from the scavenging openings 16 and 17 is stopped. From this point, the valve chamber 34 of the rotary valve 33 is opened to both the mixing chamber 31 and the rich mixture supply scavenging passage 18, and the rich mixture in the mixing chamber 31 passes through the rich mixture supply scavenging passage 18. Passed through, and supplied to the combustion chamber 13 through the scavenging opening 19 to scavenge the remaining burned gas, and at the same time, the crank chamber 9 is expanded through the intake valve 10 through the reed valve 12 by the expansion of the piston 6. Air is sucked into 9. In the scavenging of the residual burned gas, there is almost no air blow through of the air-fuel mixture.
[0041]
Thus, in the spark ignition type two-cycle internal combustion engine 1 shown in the figure, scavenging with only air is performed at the beginning of scavenging, so that the air-fuel mixture passes through the combustion chamber 13 as it is and is discharged into the exhaust passage 21. Therefore, improvement in fuel consumption and prevention of air pollution by unburned gas can be achieved.
[0042]
In addition, since only air is supplied into the crank chamber 9, even if the bearing portion of the crankshaft 8 and the sliding portion between the cylinder hole 5 and the piston 6 are not lubricated by the mixed oil in the fuel, Since oil is supplied from the oil pump 59 to the sliding portion between the bearing portion of the crankshaft 8 and the cylinder hole 5 and the piston 6 through the oil supply passages 63 and 64, the spark ignition type two-cycle internal combustion engine 1 has a friction loss. The operation can be performed in a state where there is a small amount of white smoke, and the generation of white smoke due to the mixed oil in the fuel can also be prevented.
[0043]
In addition, since the rotary valve 33 is provided below the communication path 32 and the mixing chamber 31 that are connected to the chamber 29, the fuel supplied from the fuel injection valves 37 and 39 into the mixing chamber 31 is provided. May adhere to the inner wall of the mixing chamber 31 and accumulate in the bottom of the mixing chamber 31 or in the valve chamber 34, the stagnant fuel is substantially removed by vigorous fuel flow due to intermittent opening and closing of the rotary valve 33. All of the fuel can be reliably discharged into the combustion chamber 13, the amount of fuel supplied into the combustion chamber 13 can be controlled appropriately and with good responsiveness, and a stable combustion state can be obtained.
[0044]
Further, since the two fuel injection valves 37 and 39 are provided, not only a large amount of fuel can be injected, but also fine flow rate adjustment can be easily performed while maintaining the measurement accuracy at a high level.
[0045]
Furthermore, since the fuel injection valve 37 is arranged in the radial direction of the rotary valve 33 and the fuel injection valve 39 is arranged in the rotation axis direction of the rotary valve 33, the fuel injection valves 37 and 39 do not interfere with each other. The fuel can be reliably injected into the valve chamber 34 of the rotary valve 33, and the fuel injection amount from the fuel injection valve 37 can be suppressed to suppress the fuel in the mixing chamber 31. In addition, the injected fuel particles injected from the fuel injection valves 37 and 39 can collide with each other to further atomize the injected fuel particles.
[0046]
Moreover, since the fuel injection valve 39 is arranged on the rotation axis of the rotary valve 33, fuel can be injected into the valve chamber 34 regardless of the opening position of the valve chamber 34 of the rotary valve 33. As a result of the injected fuel being allowed to cross the radial airflow passing through the valve chamber 34 of the rotary valve 33 and being sufficiently mixed with the intake air, the atomization of the fuel can be promoted.
[0047]
Further, since the valve chamber 34 in the rotary valve 33 communicates with the concentrated mixture supply scavenging passage 18 from the state previously communicated with the inside of the mixing chamber 31, the liquid fuel in the vicinity of the rotary valve 33 Even if the fuel remains, these fuels adhere to the valve chamber 34 side of the rotary valve 33 and can be atomized by the airflow from the beginning of the next opening timing.
[0048]
Next, the book illustrated in FIGS. Request Light The fruit Processing State explain about.
In this embodiment, the above Basics The air passage 24 in the embodiment is abolished, and the chamber 29 is compressed from the combustion chamber 13 through a pair of air passages 70. line In the process, air compressed to a high pressure is introduced. And in the chamber 29, Basics It is mixed with the fuel injected from the fuel injection valves 83 and 84 similar to that in the embodiment to become a rich mixture, and scavenging line At the end of the process, the fuel is supplied to the combustion chamber 13 through the rich mixture supply scavenging passage 73 (see FIG. 24).
[0049]
Here, the high-pressure air filling from the combustion chamber 13 to the chamber 29 is performed as shown in FIG. line Compress after completion line The operation is started simultaneously with the start of the operation, and is stopped after the supply of the rich mixture to the combustion chamber 13 is stopped. Other operations are described above. Basics Since it is the same as in the embodiment, the description is omitted.
[0050]
Next, in this embodiment, the means for realizing the timing of filling and stopping the high-compressed air from the combustion chamber 13 to the chamber 29 and supplying and stopping the rich mixture from the chamber 29 to the combustion chamber 13 as described above. Will be described.
The pair of air passages 70 and the rich mixture supply scavenging passage 73 are provided with a common control valve capable of opening and closing the passages, and the control valve is also used as the rotary valve 76 in this embodiment. It is configured.
[0051]
The rotary valve 76 is housed in the valve housing hole 82, and the pair of air passages 70 and the rich mixture supply scavenging passage 73 open to the valve housing hole 81.
Further, as shown in FIGS. 21 to 23, these passages are communicated with the outer periphery of the rotary valve 76 at positions corresponding to the pair of air passages 70 and the rich mixture supply scavenging passage 73. A notch 77 having a predetermined length in the circumferential direction and a notch 78 having a substantially semicircular cross section are formed. By these notches, the combustion chamber 13 to the chamber 29 as described above shown in FIG. The timing of filling and stopping the high-compressed air and supplying and stopping the rich mixture from the chamber 29 to the combustion chamber 13 are set.
[0052]
Further, a pulley 79 is integrally attached to the valve shaft end of the rotary valve 76, and the pulley 79 is connected to a pulley 80 integrally attached to the balancer shaft 69 as shown in FIG. When the cog belt 81 is placed between the spark ignition type two-cycle internal combustion engine 1, the crankshaft 8 rotates and the drive gear 57 mounted integrally with the crankshaft 8 is connected to the balancer gear 55. As a result, the balancer weight 54 integrally attached to the balancer shaft 69 rotates in the opposite direction to the crankshaft 8, and the rotary valve 76 also rotates in the opposite direction to the crankshaft 8 at the same rotational speed as the crankshaft 8. It is designed to be driven.
[0053]
Further, a notch 77 which is a fuel control unit of the rotary valve 76 has a flow of the rich mixture passing through the rich mixture supply scavenging passage 73, as better illustrated in FIG. During the control, the position is set to be lower than the air-fuel mixture intake opening 75 which is a part where the rich air-fuel supply scavenging passage 73 is connected to the chamber 29. Note that 74 is an air-fuel mixture jetting opening that is a communication part with the combustion chamber 13 of the scavenging passage 73 for supplying the rich mixture, and 71 is an intake opening for high-compressed air that is a communication part with the combustion chamber 13 in the air passage 70. , 72 are high-compressed air ejection openings which are connected to the chamber 29 of the air passage 70.
[0054]
In the present embodiment, as described above, the air is charged into the chamber 29 from the combustion chamber 13 under the compression stroke through the pair of air passages 70. A constant high pressure can be utilized, Basics Compared with the filling using the pressure in the crank chamber 9 in the embodiment, there is no influence of the pressure drop due to the full opening of the throttle valve accompanying the increase in the engine speed, so a more reliable and stable high chamber pressure can be obtained.
[0055]
The air-fuel mixture obtained by filling the chamber 29 with air is a rich air-fuel mixture, which is sufficiently scavenged by air that does not contain fuel that has passed through the air supply scavenging passages 14 and 15. As a result, the air-fuel mixture has an appropriate concentration in the combustion chamber 13 and good combustion can be obtained, so that high fuel efficiency and high exhaust purification performance can be achieved.
[0056]
In addition, since the high compressed air for producing the rich air-fuel mixture is obtained from the combustion chamber 13, the rotary valve 76 disposed in the communication path that connects the chamber 29 and the combustion chamber 13 is connected to the cylinder near the combustion chamber 13. As a result, the length of the communication path between the rotary valve 76 and the mixture injection opening 74 can be shortened, and fuel can be moved through the communication path accordingly. The amount of air required for the operation can be reduced.
In addition, the time required for the fuel to move through the communication path is shortened, the influence of the time factor on the setting of the opening timing of the rotary valve 76 is reduced, and the opening timing of the rotary valve 76 is easily set. In addition, the opening timing of the set rotary valve 76 is easily adapted over a wide rotational speed range.
[0057]
Further, the notch 77 of the rotary valve 76 communicates and blocks the concentrated gas supply scavenging passage 73, and the part that actually controls the flow of the rich gas mixture (the control unit of the rotary valve 76), Since the fuel is injected from the fuel injection valves 83 and 84, the fuel injected from the fuel injection valves 83 and 84 adheres to the inner wall of the chamber 29, and the bottom of the chamber 29 or the chamber 29 Even if the concentrated gas supply scavenging passage 73 communicated with the rotary valve 76 may accumulate in the lowermost part of the scavenging passage 73 or the rotary valve 76, the stagnant fuel may be substantially reduced by vigorous mixed air flow due to intermittent opening and closing of the rotary valve 76. All the fuel can be reliably discharged into the combustion chamber 13, and as a result, the amount of fuel supplied into the combustion chamber 13 can be appropriately controlled with good responsiveness, and a stable combustion state can be obtained.
[0058]
Next, illustrated in FIGS. Book Wish invention of Similar to the embodiment Embodiments will be described.
This resemblance In an embodiment, Of the present invention In the embodiment, the pair of air passages 70 and the rich mixture supply scavenging passage 73 constitute a common communication passage 86, and the notch 90 of the rotary valve 89 corresponds to 1 as shown in FIG. It is supposed to be.
[0059]
Therefore, both the filling of the highly compressed air from the combustion chamber 13 to the chamber 29 and the supply of the rich air-fuel mixture from the chamber 29 to the combustion chamber 13 are performed via the common communication passage 86, and the communication passage 86 is connected to the rotary valve. This is done while in communication with 89 notches 90. And the power which fills and supplies those fluids to each chamber is the pressure balance of both chambers.
[0060]
Here, as shown in FIG. 34, the timing of stopping the filling of the high compressed air from the combustion chamber 13 to the chamber 29, the start of the supply of the rich mixture from the chamber 29 to the combustion chamber 13, and What is timing? Invention of the present application This is the same as in the embodiment.
On the other hand, the timing of the start of high-compressed air filling from the combustion chamber 13 to the chamber 29 is determined by the operation of the notch 90 having a predetermined length in the circumferential direction of the rotary valve 89 in the communication passage 86. From the start of supply to the combustion chamber 13 from the chamber 29 to the stop of filling of the highly compressed air from the combustion chamber 13 to the chamber 29, the combustion chamber 13 and the chamber 29 are in a continuous communication state. This is when the pressure balance of the gas mixture becomes equal and the supply of the rich mixture to the combustion chamber 13 from the chamber 29 stops. Invention of the present application This is different from the case of the embodiment.
[0061]
In addition, the opening 87, which is a communication portion of the communication path 86 with the combustion chamber 13, is increased in length in the vertical direction so that a sufficient amount of highly compressed air can be taken into the chamber 29. The area is made considerably larger than that in the middle of the passage, and has a shape that widens toward the combustion chamber 13 (see FIGS. 26 and 28).
[0062]
In addition, the communication path 86 is Similar In the embodiment, the communication passage 86a on the combustion chamber 13 side, the communication passage 86b facing obliquely upward on the chamber 29 side, and the communication passage 86b are bent at right angles across the control unit of the rotary valve 89. The communication passage 86c is inclined upward and is composed of three parts, and the end of the communication passage 86c is connected to the chamber 29 through the opening 88.
The fuel injected from two fuel injection valves (not shown) passes through the communication passages 86b of the left and right wings, and sucks the highly compressed air in the chamber 29 through the communication passages 86c. Thus, the fuel is injected into the combustion chamber 13 via the control unit of the rotary valve 89.
[0063]
Therefore, the control unit of the rotary valve 89 is not limited to the opening 88, but to the right-angled bent portion (portion where the suction air from the chamber 29 collides with the injected fuel) with respect to the communication path 86b of the communication path 86c. However, even if fuel may be accumulated in the communication path 86b or the control unit of the rotary valve 89, the staying fuel is caused by intermittent opening and closing of the rotary valve 89. With the vigorous mixed airflow, almost all of the staying fuel can be reliably discharged into the combustion chamber 13, and as a result, the control of the fuel supply amount into the combustion chamber 13 is appropriately performed with good responsiveness, A stable combustion state can be obtained.
[0064]
30 to 33 show the state of the engine at each point of time of compression, air chamber filling, intake, expansion, fuel injection, exhaust, scavenging, exhaust, mixture supply, and intake. Detailed description is omitted.
In addition, 88 is an opening which is a connection portion of the communication path 86 with the chamber 29, 91 is a housing hole for the rotary valve 89, and 92 is a mounting hole for the fuel injection valve.
[0065]
Similar Since the embodiment is configured as described above, the configuration of the high-compression air passage and the scavenging passage for supplying the rich mixture and the configuration of the control valve are simplified, and the manufacture is facilitated.
[Brief description of the drawings]
[Figure 1] Book Request Light The fruit Form Of the basic embodiment of It is a vertical side view.
FIG. 2 is a longitudinal sectional view taken along line II-II in FIG.
3 is a longitudinal sectional view taken along line III-III in FIG. 1. FIG.
4 is an enlarged vertical sectional side view of a main part of FIG. 1. FIG.
5 is a cross-sectional plan view taken along line VV in FIG. 4. FIG.
6 is a cross-sectional plan view taken along line VI-VI in FIG.
7 is a view taken in the direction of arrows VII-VII in FIG. 1, and a portion with a dot is a contact surface with a crankcase.
8 is a view taken along arrow VIII-VIII in FIG.
FIG. 9 is a longitudinal front view of a cylinder block.
10 is a cross-sectional plan view taken along line XX in FIG. 9. FIG.
11 is a XI-XI arrow view of FIG. 1. FIG.
FIG. 12 is a drawing illustrating a state of 45 ° before top dead center (TDC).
FIG. 13 is a drawing illustrating a state of 45 ° after top dead center (TDC).
FIG. 14 is a diagram illustrating a bottom dead center (BDC) state.
FIG. 15 is a drawing illustrating a state of 90 ° before top dead center (TDC).
FIG. 16 Basics It is explanatory drawing which illustrated the driving cycle of embodiment.
FIG. 17 Book Request Light The fruit It is a vertical side view of embodiment.
18 is a cross-sectional plan view taken along line XVIII-XVIII in FIG.
FIG. 19 is an enlarged view of a main part of FIG.
20 is a schematic longitudinal sectional side view showing a power transmission mechanism between a crankshaft and a rotary valve of the embodiment of FIG. 17;
FIG. 21 is a partial longitudinal sectional view of the rotary valve of the embodiment of FIG.
22 is a longitudinal side view cut along the line XXII-XXII in FIG. 21. FIG.
23 is a longitudinal side view taken along line XXIII-XXIII in FIG. 21. FIG.
24 is an explanatory diagram illustrating an operation cycle of the embodiment of FIG. 17;
FIG. 25 Book Request Light The fruit Form Similar embodiments for It is a top view of a cylinder block.
26 is a longitudinal side view cut along the line XXVI-XXVI of FIG. 25, and shows a state where a lid is attached.
27 is a cross-sectional plan view taken along the line XXVII-XXVII in FIG. 26, and shows a state where a lid is removed. FIG.
28 is a longitudinal side view cut along the line XXVIII-XXVIII in FIG.
29 is a partial longitudinal sectional view of the rotary valve of the embodiment of FIG. 25. FIG.
30 is a view illustrating a state at the time of compression, air chamber filling, and intake of the embodiment of FIG. 25;
FIG. 31 is a drawing illustrating a state during the expansion.
FIG. 32 is a drawing illustrating states during fuel injection, exhaust, and scavenging.
FIG. 33 is a drawing illustrating a state during the exhaust / mixture supply / intake.
34 is an explanatory diagram illustrating an operation cycle of the embodiment of FIG. 25. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Spark ignition type 2 cycle internal combustion engine, 2 ... Crank case, 3 ... Cylinder block, 4 ... Cylinder head, 5 ... Cylinder hole, 6 ... Piston, 7 ... Connecting rod, 8 ... Crankshaft, 9 ... Crank chamber, 10 ... intake passage, 11 ... throttle valve, 12 ... reed valve, 13 ... combustion chamber, 14, 15 ... scavenging passage for air supply, 16, 17 ... scavenging opening, 18 ... scavenging passage for supplying rich mixture, 19 ... scavenging opening , 20 ... Valve housing hole, 21 ... Exhaust passage, 22 ... Exhaust opening, 23 ... Spark plug, 24 ... Air passage, 25 ... Air introduction groove, 26 ... Reed valve, 27 ... Septum, 28 ... Lid, 29 ... Chamber, 30 ... Air passage, 31 ... Mixing chamber, 32 ... Communication hole, 33 ... Rotary valve, 34 ... Valve chamber, 35 ... Fuel introduction passage, 36 ... Fuel injection valve mounting hole, 37 ... Fuel injection valve, 38 ... Fuel injection valve Mounting hole, 39 ... Fuel injection valve, 40 ... Exhaust control valve, 41 ... Recess, 42 ... Exhaust passage member, 43 ... Gap, 44 ... Exhaust pipe mounting member, 45 ... Rotating shaft 46 ... Split surface, 47 ... Main shaft, 48 ... Counter shaft, 49 ... Clutch, 50 ... Transmission gear group, 51 ... Drive gear, 52 ... Drive gear, 53 ... Chain sprocket, 54 ... Balancer weight, 55 ... Balancer gear, 56 ... driven gear, 57, 58 ... drive gear, 59 ... oil pump, 60 ... drive shaft, 61 ... driven gear, 62 ... intermediate gear, 63, 64 ... oil supply path, 65 ... water pump, 66 ... rotating shaft, 67 ... driven gear, 68 ... cooling water passage, 69 ... balancer shaft, 70 ... air passage, 71 ... suction opening, 72 ... jetting opening, 73 ... scavenging passage for supplying concentrated mixture, 74 ... jetting opening, 75 ... suction opening , 76 ... Rotary valve, 77 ... Notch, 78 ... Notch, 79 ... Pulley, 80 ... Pulley, 81 ... Cog belt, 82 ... Valve housing hole, 83 ... Fuel injection valve, 84 ... Fuel injection valve, 86 ... Communication path , 87 ... opening, 88 ... opening, 89 ... rotary valve, 90 ... notch, 91 ... valve storage hole, 92 ... fuel injection valve mounting hole.

Claims (2)

A two-cycle internal combustion engine that is provided with a control valve for controlling the communication passage so that the communication passage can be opened and closed, and that supplies fuel to the combustion chamber via the communication passage. In the institution
The chambers are arranged side by side on the combustion chamber side, and at least the control unit of the control valve is provided below the connection portion with the chamber to supply only the air in the crank chamber to the combustion chamber. the scavenging passage is provided for, said communication opening which opens into the combustion chamber of the communication passage is positioned above said control valve is provided, wherein the communication passage includes a first high compressed air flows from said combustion chamber to said chamber A communication passage and a second communication passage through which the air-fuel mixture flows from the chamber to the combustion chamber, and the control valve is provided in the first communication valve and the second communication passage provided in the first communication passage. The second control valve having the control unit, the first control valve communicates the first communication path in the vicinity of the exhaust opening closed time, and closes the first communication path in the middle of the compression stroke, The second control valve is Air- during opening closed communicating the second communication passage, and two-stroke internal combustion engine, wherein said first communication passage in the process of compression stroke to close the second communication passage before being closed. The first control valve and the second control valve are constituted by a common rotary valve, and are provided on the outer periphery of the rotary valve with notches that respectively connect the first communication path and the second communication path. 2. The two-cycle internal combustion engine according to claim 1 , wherein the control portion of the second control valve is configured by the notch .

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