JPH09144545A - Two-cycle internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-cycle internal combustion engine which impedes a blowby, enhances the fuel consumption efficiency and exhaust purifying performance further improves responsiveness of a fuel injection amount. SOLUTION: In a two-cycle internal combustion engine arranged with a chamber 29 in scavenge passages 30, 31 connecting a crank chamber 9 and a combustion chamber 6, provided with closable control valves 26, 33 respectively in an inlet/outlet of the chamber 29 and provided with a fuel supply device 37 supplying fuel into the chamber, the chamber 29 communicates with one scavenge passage 18 of a plurality of the parallel scavenge passages, a combustion chamber side control valve 33, provided in the outlet of the chamber 29 in the scavenge downstream from the crank chamber side control valve 26 provided in the inlet of the chamber 29, is arranged in the lowest part of the scavenge passage 18 communicating with the chamber 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents blowout of air-fuel mixture in a combustion chamber to improve fuel economy and exhaust gas purification performance.
The present invention relates to a cycle internal combustion engine.

[0002]

2. Description of the Related Art In a conventional two-stroke internal combustion engine, fuel supplied by a carburetor or the like is mixed with intake air, and this mixture is sucked into a crank chamber and then supplied to a combustion chamber through a scavenging opening. Since the opening timing of the exhaust opening 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 to the exhaust passage. Thus, the so-called blow-by easily occurred.

Although this blow-by is suppressed by the exhaust pulsation effect of the exhaust chamber, it is difficult to suppress it over the entire operating range, and as a result, fuel consumption and exhaust purification performance are affected.

To solve this problem, Japanese Patent Laid-Open Publication No.
[0031] There is a two-stroke internal combustion engine disclosed in JP-A-00318 and JP-A-5-302521.

In the two-cycle internal combustion engine described in Japanese Patent Laid-Open No. 3-100318, a high pressure chamber is connected to the crank chamber via a check valve, and the high pressure chamber and the combustion chamber are connected by an air passage, An electromagnetic valve is provided 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.

Further, in the two-cycle internal combustion engine disclosed in JP-A-5-302521, a chamber is arranged adjacent to the crank case and the cylinder block, and an intake control valve is interposed between the crank chamber and the chamber. A scavenging control valve is provided between the chamber and the combustion chamber of the cylinder, and a fuel injection valve for injecting fuel into the chamber is provided.

[0007]

In the two-cycle internal combustion engine disclosed in Japanese Patent Laid-Open No. 3-100318, of the fuel injected from the fuel injection valve, the fuel adhering to the air passage falls due to gravity, and the bottom portion of the air passage is formed. Enters the crank chamber through the check valve and flows from the crank chamber through the other scavenging openings into the combustion chamber without being atomized, so that blow-by is not sufficiently prevented and stable combustion is difficult to occur. In addition, the fuel supply amount into the combustion chamber is not properly controlled, resulting in poor response.

Further, JP-A-5-302521, No. 2
In a cycle internal combustion engine, all the intake air in the crank chamber is introduced into the chamber through the intake control valve, mixed with the fuel injected into the chamber from the fuel injection valve, and all is introduced into the combustion chamber through the scavenging control valve. Since only air from the crank chamber can flow into the combustion chamber through the scavenging opening, blow-through is unavoidable, and the upstream port of the scavenging control valve does not open below the chamber. However, since it is not at the bottom, the fuel injected into the chamber accumulates at the bottom of the chamber, and the fuel supply amount into the combustion chamber cannot accurately correspond to the fuel injection amount,
After all, there is a drawback that the response is not good.

[0009]

The invention of the present application relates to an improvement of a two-cycle internal combustion engine which overcomes the above problems, and the invention described in claim 1 thereof is a combustion chamber and a fuel injection device. In a two-cycle internal combustion engine, a control valve for controlling opening and closing of the communication passage is provided in a communication passage with a chamber in which the chamber is provided, and the fuel is supplied to the combustion chamber through the communication passage. Is disposed on the side of the combustion chamber, and at least the control portion of the control valve is provided below a connection portion with the chamber.

According to the first aspect of the present invention, the fuel is supplied to the combustion chamber through the communication passage as described above. Therefore, in the scavenging step, air containing no fuel is passed through the scavenging passage to enter the combustion chamber. By introducing it, burnt gas in the combustion chamber can be reliably discharged from the exhaust opening, and as a result, blow-through of the air-fuel mixture in the combustion chamber can be prevented, and at the time of low addition, scavenging efficiency by air scavenging Can be improved.

Further, since at least the control portion of the control valve is provided below the connection portion with the chamber,
Even if the fuel supplied from the fuel supply device into the chamber may accumulate at the bottom of the chamber, the communication passage communicating with the chamber, the lower portion of the control valve, etc.
It is possible to reliably discharge substantially all of the accumulated fuel into the combustion chamber by violent fuel flow due to the intermittent opening and closing of the control valve, and as a result, it is possible to properly control the fuel supply amount into the combustion chamber and to improve the responsiveness. It will be performed well and a stable combustion state can be obtained.

Further, as described above, since the chamber is arranged on the side of the combustion chamber, the entire engine can be gathered into a condensed shape having a substantially rectangular shape in a side view. By comparison, the vertical 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 is increased, and particularly when the engine is mounted on a motorcycle, the vehicle height and the minimum ground clearance are not increased.

Next, by constructing the invention according to claim 1 as described in claim 2, since the fuel supplied to the combustion chamber scavenges the remaining burned gas, the blow-through is prevented. Therefore, the fuel can be reliably fed into the combustion chamber.

By constructing the invention according to claim 1 or claim 2 as described in claim 3, it becomes easy to control the opening and closing of the control valve in synchronization with the rotation of the crankshaft of the engine.

Further, by constructing the invention according to any one of claims 1 to 3 as described in claim 4, the fuel is mixed with the fuel supplied to the combustion chamber through the communication passage between the combustion chamber and the chamber. A relatively small amount of air can be reliably taken into the chamber, and sufficient pressure can be obtained to send the air-fuel mixture into the combustion chamber through the communication passage.

The mixture becomes a rich mixture and flows into the combustion chamber sufficiently scavenged by the fuel-free air that has passed through the other scavenging passages.
In the combustion chamber, an air-fuel mixture having an appropriate concentration can be obtained, good combustion can be obtained, and a high level of fuel consumption and high exhaust gas purification performance can be achieved.

In addition, at the initial stage of scavenging, the valves (gate valve and control valve) at the inlet and outlet of the chamber are closed, air containing no fuel is introduced into the combustion chamber from another scavenging passage, and the burnt gas in the combustion chamber is burned. It is possible to reliably discharge the gas from the exhaust opening, and as a result, it is possible to prevent blow-through of the air-fuel mixture introduced into the combustion chamber through the communication passage at the end of scavenging (when the scavenging opening is closed).

Further, by constructing the invention according to any one of claims 1 to 3 as described in claim 5, since the high pressure in the combustion chamber can be utilized for filling the chamber with air, the crank chamber can be utilized. Compared to filling by pressure
A more reliable and stable high chamber pressure can be obtained.

Further, 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 the fuel-free air passing through the other scavenging passages. In this case, the air-fuel mixture has an appropriate concentration in the combustion chamber, good combustion can be obtained, and a high level of fuel consumption and high exhaust gas purification performance can be achieved.

Further, since the highly compressed air for producing the rich air-fuel mixture is obtained from the combustion chamber, the control valve provided in the communication passage connecting the chamber and the combustion chamber is provided with a cylinder wall near the combustion chamber. As a result, the length of the communication passage between the control valve and the mixture injection opening can be shortened, and as a result, it is necessary to move the fuel through the communication passage. The amount of carrier gas (air) that has been retained can be reduced.

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 rotational speed, the earlier the opening timing should be set. Where necessary, as described above, since the length of the communication passage between the control valve and the mixture injection opening can be shortened, the time required for the fuel to move through the communication passage is shortened, The influence of the time factor on the setting of the opening timing of the control valve is small, and as a result, the opening timing of the control valve can be set easily, and the set opening timing of the control valve can be easily adapted over a wide rotational speed range. Become.

Furthermore, by constructing the invention according to claim 5 as described in claim 6, the structure of the communication passage is simplified, and the manufacture is facilitated.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION First, one embodiment (hereinafter, referred to as a first embodiment) of the invention described in claims 1 to 4 of the present application shown in FIGS. 1 to 16 will be described below.
Will be described. 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 arranged above a crankcase 2. They are overlapped and are integrally connected to each other.
Further, a piston 6 is fitted in a cylinder hole 5 formed in the cylinder block 3 so as to be vertically slidable.
The crankshaft 8 and the crankshaft 8 are interconnected by a connecting rod 7, and the crankshaft 8 is rotationally driven as the piston 6 moves up and down.

Further, an intake passage 10 directed from the rear side to the front side 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 provided in series in the intake passage 10, and a throttle valve Reference numeral 11 is connected to a throttle grip (not shown) via a connecting means (not shown), and when the throttle grip is twisted in one direction, the opening of the throttle valve 11 is increased.

Further, the crankcase 2 and the cylinder block 3 are provided with four air supply scavenging passages 14 and 15 for connecting the upper part of the cylinder hole 5 and the crank chamber 9 with each two left and right. At the same time, the scavenging openings 16 and 17 of the air supply scavenging passages 14 and 15 are located near the rear of the vehicle body.
The position of the scavenging opening 19 is higher than that of the scavenging passage for supplying rich mixture
18 is formed, and the scavenging passage 18 for supplying the rich mixture is a scavenging opening.
Extend downward from 19 toward the intake passage 10 to reach the crankshaft 8
Is opened in the valve housing hole 20 of the crankcase 2 parallel to the cylinder case 5 and the exhaust opening 22 on the cylinder hole 5 side of the exhaust passage 21 is arranged at a position opposed to the scavenging opening 19.

Moreover, the substantially hemispherical combustion chamber 13 above the cylinder hole 5 is offset toward the exhaust opening 22, and the spark plug 23 is disposed in the combustion chamber 13.

The cylinder block 3 has an intake passage.
An air passage 24 is formed at a position directly above 10 and a lower surface of the cylinder block 3 that abuts the crankcase 2 bypasses the outer periphery of the cylinder hole 5 and an air supply scavenging passage 14 near the intake passage 10. An air introduction groove 25 that communicates with the air passage 24 is formed, a reed valve 26 that is a crank chamber side control valve is provided above the air passage 24, and the combustion chamber 13 of the cylinder block 3 surrounds the reed valve 26. A partition 27 is formed at a lateral position, a lid 28 is detachably attached to an opening edge of the partition 27, and the partition 27 and the lid 28 form a chamber 29.

Further, the cylinder block 3 has an air passage.
An air passage 30 oriented vertically is formed on both right and left sides of 24, and the crankcase 2 has a mixing chamber 31 which communicates with a lower end of the air passage 30 at both left and right end portions and a central portion through a communication hole 32. And a rotary valve 33, which is a combustion chamber side control valve, is rotatably fitted in the valve housing hole 20.
33 is a valve chamber that opens in the circumferential direction at the center in the longitudinal direction.
A fuel introduction passage that communicates with the valve chamber 34 from the left end of the rotary valve 33 and the rotary valve 33.
35 are formed, and as will be described later, they are rotationally driven in the same direction as the crankshaft 8 (counterclockwise in FIGS. 1 and 4) at the same rotational speed.

Furthermore, a fuel injection valve mounting hole 36 is formed in the crankcase 2 from the rear of the vehicle toward the mixing chamber 31, and a fuel injection valve 37 is mounted in the fuel injection valve mounting hole 36. A fuel injection valve mounting hole 38, which communicates with the fuel introduction passage 35 from the left side surface of the crankcase 2 toward the fuel introduction passage 35, is formed, and the fuel injection valve 39 is attached to the fuel injection valve attachment hole 38.

Further, as shown in FIG. 6, the exhaust passage
An exhaust control valve 40 is provided in the vicinity of the exhaust opening 22 of 21, and the exhaust control valve 40 has a recess 41 formed in the cylinder block 3 and having an arcuate vertical cross section, and a vertical cross sectional shape substantially the same as the recess 41. The exhaust passage member 42 is fitted in a gap 43 located between the exhaust passage member 42 and the formed exhaust passage member 42, and is rotatably pivoted to the exhaust passage member 42 and an exhaust pipe mounting member 44 integrally connected to the exhaust passage member 42. A base portion of the exhaust control valve 40 is integrally mounted on a supported rotary shaft 45, and the rotary shaft 45 is connected to an exhaust control servomotor (not shown). The opening of the throttle valve 11 and the spark ignition type two-cycle internal combustion engine. The exhaust control servomotor is operated by a control signal output from a CPU (not shown) on the basis of a map of the exhaust opening ratio in which the rotation speed of the engine 1 is an independent variable, and the optimum exhaust opening ratio suitable for the operating condition is obtained. Exhaust control valve 40 is swung so that It has become to so that.

Further, as shown in FIGS. 3 and 11, the crankcase 2 is divided into a left crankcase 2l and a right crankcase 2r with the split surface 46 as a boundary, and is located behind the crankshaft 8. Is positioned at a main shaft 47 and a counter shaft 48, which are rotatably supported by the left crank case 2l and the right crank case 2r. The main shaft 47 is provided with a clutch 49 and the main shaft 47 and the counter shaft 48. Is provided with a speed change gear group 50, a drive gear 51 at the right end of the crankshaft 8 is meshed with a driven gear 52 of a clutch 49, and a chain sprocket 53 is integrally mounted at the left end of the counter shaft 48. An endless chain is mounted on the chain sprocket (not shown) on the rear wheel.
The cycle internal combustion engine 1 is in the operating state, and the clutch 49
Is set to the connected state, the rotational force of the crankshaft 8 is transmitted to the chain sprocket 53 via the drive gear 51, the driven gear 52, the clutch 49, the speed change gear group 50 and the counter shaft 48, and the rear wheels are rotationally driven. It is supposed to be done.

Further, a balancer weight 54 located diagonally above and above the crankshaft 8 for canceling the primary inertial force of the crankshaft 8 is rotatable between the left crankcase 2l and the right crankcase 2r. The balancer is pivotally supported
54, the balancer gear 55 is integrally mounted on the right end, and the driven gear 56 on the right side of the rotary valve 33 is integrally mounted. The drive gear 57 of the crankshaft 8 and the balancer gear
55 and the driven gear 56 are sequentially meshed, and the crankshaft 8
When the rotary shaft is rotated, the balancer weight 54 is rotationally driven in the direction opposite to the crankshaft 8 and the rotary valve 33 is rotationally driven in the same direction as the crankshaft 8 at the same rotational speed as the crankshaft 8.

Further, the drive gear 58 is fitted to the right end of the rotary valve 33, and the plunger type oil pump 59 is disposed adjacent to the right side of the rotary valve 33, and the drive shaft 60 of the oil pump 59.
An intermediate gear 62 is meshed with a driven gear 61 and a drive gear 58 that are integrated with the oil pump 59. When the crankshaft 8 rotates and the rotary valve 33 is rotationally driven, the oil pump 59 is driven. .

The oil from the oil pump 59 is supplied to the bearing portion of the crankshaft 8 via the oil supply passage 63 (see FIG. 2) and the oil supply passage 64 (see FIG. 10).
It is supplied to the sliding portion between the cylinder hole 5 and the piston 6 via.

Further, as shown in FIG. 2, a drive gear 51 at the right end of the crankshaft 8 is meshed with a driven gear 67 which is integral with a rotary shaft 66 of a water pump 65, and a spark ignition type two-cycle internal combustion engine. When 1 is in the operating state, the water pump 65 is rotationally driven, and the cooling water in the spark ignition two-cycle internal combustion engine 1 is sent to a radiator (not shown) to be cooled, and then the spark ignition two-cycle internal combustion engine 1 is cooled. It returns to the water passage 68 again.

Since the illustrated spark ignition type two-cycle internal combustion engine 1 is constructed as described above, when the crankshaft 8 is rotationally driven counterclockwise in FIGS. 12 to 15 by a starter motor (not shown), 75 ° before top dead center (TDC)
At this time point, the scavenging opening 19 of the rich air-fuel mixture supply scavenging passage 18 is closed by the piston 6, the combustion chamber 13 is compressed, the spark plug 23 is ignited at a predetermined timing before top dead center, and the piston 6 Crank chamber 9 continues to expand due to the rise of the intake air, and intake is continued (see FIG. 12).

After reaching the top dead center (TDC),
As shown in FIG. 13, the air-fuel mixture in the combustion chamber 13 burns and expands, and the piston 6 descends to compress the crank chamber 9, and the air in the crank chamber 9 is compressed.

Further, when 90 ° has passed from the top dead center (TDC) (it fluctuates depending on the vertical position of the exhaust control valve 40), the exhaust opening 22 is opened and the combustion gas is exhausted from the exhaust passage 21. From about this time point, the compressed air in the crank chamber 9 is transferred to the air supply scavenging passage 14 near the intake passage 10.
Flows into the air passage 24 through the air introduction groove 25 and is introduced into the chamber 29 from the air passage 24 through the reed valve 26.

Furthermore, about 122% from the top dead center (TDC)
°, the scavenging opening 1
6 and 17 are opened, and the air (not containing fuel) in the crank chamber 9 flows into the combustion chamber 13 through the scavenging openings 16 and 17 through the air supply scavenging passages 14 and 15, and the inside of the combustion chamber 13 is reached. The burned gas of the is extruded toward the exhaust opening 22, scavenging is performed only with air, and 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. Generated (see Figure 14).

Next, when about 58 ° has passed from the bottom dead center (BDC), the scavenging openings 16 and 17 are closed by the rise of the piston 6, and the scavenging by the inflow of air from the scavenging openings 16 and 17 is stopped. Together with this, from almost this time, the valve chamber of the rotary valve 33
34 is opened to both the mixing chamber 31 and the scavenging passage 18 for supplying rich mixture, the rich mixture in the mixing chamber 31 passes through the scavenging passage 18 for supplying rich mixture, and the combustion chamber 13 is opened from the scavenging opening 19. Is supplied to the inside of the crank chamber 9 to scavenge the residual burned gas, and at the same time, due to expansion of the crank chamber 9 due to the rise of the piston 6, air is sucked into the crank chamber 9 from the intake passage 10 via the reed valve 12.
In the scavenging of the residual burned gas, there is almost no blow-by of the air-fuel mixture.

As described above, in the illustrated spark ignition type two-cycle internal combustion engine 1, since the scavenging is performed only by the air at the initial stage of the scavenging, the air-fuel mixture passes through the combustion chamber 13 as it is and is discharged to the exhaust passage 21. Bypassing can be prevented, fuel economy can be improved, and air pollution due to unburned gas can be prevented.

Further, since only air is supplied into the crank chamber 9, the crankshaft 8 due to oil mixed in the fuel is used.
Even if lubrication of the bearing portion of the crankshaft 8 and the sliding portion between the cylinder hole 5 and the piston 6 is not performed, the bearing portion of the crankshaft 8 and the cylinder hole 5 and the piston 6 are transmitted from the oil pump 59 through the oil supply passages 63 and 64. Since the oil is supplied to the sliding portion between the two, the spark ignition type two-cycle internal combustion engine 1 can be operated in a state where the friction loss is small, and the generation of white smoke due to the mixed oil in the fuel can be prevented.

Further, since the rotary valve 33 is provided below the communication passage 32 and the mixing chamber 31 which are the connecting portions with the chamber 29, even if the fuel injection valves 37 and 39 are connected to the mixing chamber.
Even if the fuel supplied into 31 adheres to the inner wall of the mixing chamber 31 and collects in the bottom of the mixing chamber 31 or the valve chamber 34,
With the violent fuel flow due to the intermittent opening and closing of the rotary valve 33, almost all of the accumulated fuel can be reliably discharged into the combustion chamber 13, and the control of the fuel supply amount into the combustion chamber 13 responds appropriately. It becomes possible to obtain a stable combustion state.

Further, since the two fuel injection valves 37 and 39 are provided, not only a large amount of fuel can be injected, but also the delicate flow rate adjustment can be easily performed while maintaining a high metering accuracy.

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 rotational axis direction of the rotary valve 33, the fuel injection valves 37, 39 do not interfere with each other. Can be disposed near the rotary valve 33, can reliably inject fuel into the valve chamber 34 of the rotary valve 33, and suppress the fuel injection amount from the fuel injection valve 37 to suppress the mixing chamber 31. The remaining fuel inside can be prevented, and further, the injected fuel particles injected from the fuel injection valves 37, 39 can collide with each other to further atomize the injected fuel particles.

Moreover, since the fuel injection valve 39 is arranged on the rotation axis of the rotary valve 33, the fuel can be injected into the valve chamber 34 regardless of the opening position of the valve chamber 34 of the rotary valve 33, and the fuel injection can be performed. The fuel injected from the valve 39 can be sufficiently mixed with the intake air by intersecting the radial airflow passing through the valve chamber 34 of the rotary valve 33, so that atomization of the fuel can be promoted.

Further, since the valve chamber 34 in the rotary valve 33 communicates with the scavenging passage 18 for supplying the rich mixture from the state in which the valve chamber 34 is communicated with the interior of the mixing chamber 31, the liquid chamber near the rotary valve 33 becomes liquid. Even if the remaining fuel remains, these fuels will still remain in the valve chamber of the rotary valve 33.
It can be attached to the 34 side and atomized by the airflow from the beginning of the next opening time.

Next, as shown in FIGS.
One embodiment of the invention described in claim 5 of the present application (hereinafter,
This is called the second embodiment. ) Will be described. In this embodiment, the air passage 24 in the first embodiment is used.
Is abolished, and the air that has been compressed to a high pressure in the compression process is taken into the chamber 29 from the combustion chamber 13 via the pair of air passages 70. Then, in the chamber 29, the same fuel injection valve as in the first embodiment.
It is mixed with the fuel injected from 83 and 84 to form a rich air-fuel mixture, which is supplied to the combustion chamber 13 through the rich air-fuel mixture supply scavenging passage 73 at the end of the scavenging process (see FIG. 24).

Here, the filling of the high pressure air from the combustion chamber 13 to the chamber 29 is started at the same time as the start of the compression process after the end of the exhaust process, as shown in FIG. It is stopped after the supply to the chamber 13 is stopped. The other operations are the same as those in the first embodiment, and the description thereof will be omitted.

Next, in the present embodiment, the timing of filling and stopping high-compressed air from the combustion chamber 13 to the chamber 29 and supplying and stopping the rich air-fuel mixture from the chamber 29 to the combustion chamber 13 will be described. The means for realizing will be described. The pair of air passages 70 and the rich air-fuel mixture scavenging passage 73 are provided with a common control valve capable of opening and closing those passages, and the control valve is also the rotary valve 76 in the present embodiment.
Is configured as

The rotary valve 76 is housed in the valve housing hole 82, and the pair of air passages 70 and the rich air-fuel mixture scavenging passage 73 are opened in the valve housing hole 81.
The outer circumference of the rotary valve 76 is shown in FIGS.
As shown in FIG. 7, at a position corresponding to the pair of air passages 70 and the rich air-fuel mixture supply scavenging passage 73, a notch 77 having a predetermined circumferential direction for communicating these passages, having a substantially half-moon shape in cross section. Notches 78 are formed, and these notches fill the high-compressed air from the combustion chamber 13 to the chamber 29 and stop the high-compressed air as shown in FIG. The timing of supplying and stopping the chamber 13 is designed.

Further, a pulley 79 is integrally attached to the valve shaft end of the rotary valve 76, and the pulley 79 is integrally attached to the balancer shaft 69 as shown in FIG. When the cog belt 81 is bridged between the crankshaft 8 and the spark ignition type two-cycle internal combustion engine 1, the crankshaft 8 rotates, and the drive gear 57 integrally mounted on the crankshaft 8 balances the drive gear 57. Meshes with gear 55, which allows
The balancer weight 54, which is integrally mounted on the balancer shaft 69, is rotationally driven in the opposite direction to the crankshaft 8 and the rotary valve 76 is also rotationally driven in the reverse direction to the crankshaft 8 at the same rotational speed as the crankshaft 8. ing.

Further, the notch 77, which is the fuel control portion of the rotary valve 76, passes through the rich air-fuel mixture scavenging passage 73, as shown better in FIG. When the flow of the mixture is controlled, its position is substantially below the mixture intake opening 75, which is a portion where the rich mixture supply scavenging passage 73 is connected to the chamber 29. In addition, 74 is a mixture gas ejection opening which is a communication portion of the rich mixture supply scavenging passage 73 with the combustion chamber 13, and 71 is a highly compressed air suction opening which is a communication portion of the air passage 70 with the combustion chamber 13. , 72
Is an ejection opening for highly compressed air, which is a connecting portion of the air passage 70 with the chamber 29.

In the present embodiment, as described above, the air filling in the chamber 29 is performed by the combustion chamber under the compression process.
Since it is performed from 13 through the pair of air passages 70, a substantially constant high pressure in the combustion chamber 13 can be used for filling, and the pressure in the crank chamber 9 in the first embodiment is used. Compared to filling, there is no influence of pressure drop due to full opening of the throttle valve due to increase in engine speed, so a more reliable and stable high chamber pressure can be obtained.

The air-fuel mixture obtained by filling the chamber 29 with air is a rich air-fuel mixture, which is sufficiently scavenged by the fuel-free air that has passed through the air-supply scavenging passages 14, 15. Since it flows into the combustion chamber 13,
In the combustion chamber 13, an air-fuel mixture having an appropriate concentration can be obtained, good combustion can be obtained, and a high level of fuel consumption and high exhaust gas purification performance can be achieved.

Further, since the highly compressed air for producing the rich air-fuel mixture is obtained from the combustion chamber 13, the rotary valve 76 disposed in the communication passage connecting the chamber 29 and the combustion chamber 13 is used as the combustion chamber.
It is possible to provide it on the cylinder wall in the vicinity of 13, and as a result, it is possible to shorten the length of the communication passage between the rotary valve 76 and the mixture injection opening 74, and to allow the fuel to pass through the communication passage accordingly. The amount of air required to be moved can be reduced. In addition, the time required for the fuel to move through the communication passage is shortened, the influence of the factor of the time 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. And the set rotary valve
The opening timing of 76 becomes easy to adapt over a wide range of rotational speeds.

Further, the notch 77 of the rotary valve 76 communicates with and cuts off the scavenging passage 73 for supplying the rich air-fuel mixture to actually control the flow of the rich air-fuel mixture (control portion of the rotary valve 76). )
However, even if the fuel injected from the fuel injection valves 83 and 84 adheres to the inner wall of the chamber 29, the bottom of the chamber 29 and the Even if the scavenging passage 73 for supplying the rich air-fuel mixture, which communicates with the chamber 29, or the rotary valve 76 may be accumulated, the accumulated fuel may be accumulated due to the vigorous mixed air flow due to the intermittent opening and closing of the rotary valve 76. 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 can be appropriately performed with good responsiveness, and a stable combustion state can be obtained. .

Next, an embodiment of the invention described in claim 6 of the present application shown in FIGS. 25 to 34 will be described. In the present embodiment, the pair of air passages 70 and the rich air-fuel mixture supply scavenging passage 73 in the second embodiment are common communication passages 86, and the cutout 90 of the rotary valve 89 is provided.
Also, as shown in FIG. 29, there is one corresponding thereto.

Therefore, both the high-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 connected to each other via the common communication passage 86. This is performed while the cutout 90 of the rotary valve 89 is in the communicating state. The power for filling and supplying these fluids to the respective chambers is the pressure balance between both chambers.

Here, as shown in FIG. 34, the timing of stopping the filling of the highly compressed air from the combustion chamber 13 to the chamber 29 and the start of the supply of the rich mixture from the chamber 29 to the combustion chamber 13. The timing of the stop is the same as in the case of the second embodiment. On the other hand, at the timing of starting the filling of the highly compressed air from the combustion chamber 13 to the chamber 29, the communication passage 86 is provided with a cutout 90 of a predetermined length in the circumferential direction of the rotary valve 89 so that a rich mixture is generated. From the start of the supply from the chamber 29 to the combustion chamber 13 to the stop of the filling of the highly compressed air from the combustion chamber 13 to the chamber 29, the combustion chamber 13 and the chamber 29 are continuously connected. The pressure balance of the
When the supply from the fuel cell to the combustion chamber 13 is stopped, this point is different from the case in the second embodiment.

Further, the opening 87, which is a communicating portion of the communication passage 86 with the combustion chamber 13, is a chamber of a sufficient amount of highly compressed air.
In order to facilitate the incorporation into 29, its length in the longitudinal direction is made large, and the cross-sectional area is made considerably larger than that in the middle of the passage so that it is widened toward the combustion chamber 13 (Fig. 26). And FIG. 28).

Further, in the present embodiment, the communication passage 86 sandwiches the control portion of the rotary valve 89, and the communication passage 86a on the combustion chamber 13 side and the communication passage 86b facing obliquely upward on the chamber 29 side.
And a communication passage 86c that is bent at a right angle to the communication passage 86b and is directed obliquely upward. The end of the communication passage 86c is connected to the chamber 29 through the opening 88. ing. Then, the fuel injected from the two fuel injection valves (not shown) passes through the communication passages 86b of the left and right wings,
While sucking the highly compressed air in the chamber 29 through the communication passage 86c, it becomes a rich air-fuel mixture and is injected into the combustion chamber 13 through the control unit of the rotary valve 89.

Therefore, the control portion of the rotary valve 89 has the right-angled bent portion (the portion where the sucked air from the chamber 29 and the injected fuel collide with each other not only with respect to the opening 88 but also with respect to the communication passage 86b of the communication passage 86c). However, even if fuel is accumulated in the communication passage 86b or in the control portion of the rotary valve 89, these accumulated fuel is intermittently stored in the rotary valve 89. It is possible to reliably discharge almost all of the accumulated fuel into the combustion chamber 13 with a vigorous mixed air flow by opening and closing, and as a result, the amount of fuel supplied to the combustion chamber 13 can be controlled appropriately and with good responsiveness. Therefore, a stable combustion state can be obtained.

FIGS. 30 to 33 show the states of the engine at the time of compression, air chamber filling / intake, expansion, fuel injection / exhaust / scavenging, exhaust / mixture supply / intake. However, detailed description is omitted. In addition,
88 is an opening that is a connection portion of the communication passage 86 with the chamber 29,
Reference numeral 91 is a housing hole for the rotary valve 89, and 92 is a mounting hole for the fuel injection valve.

Since the present embodiment is constructed as described above, the structure of the highly compressed air passage and the scavenging passage for supplying the rich air-fuel mixture and the structure of the control valve are simple, and the manufacture is easy.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is a longitudinal sectional view cut along the line III-III in FIG. 1;

FIG. 4 is an enlarged vertical side view of a main part of FIG.

FIG. 5 is a cross-sectional plan view taken along line VV of FIG. 4;

6 is a cross-sectional plan view taken along the line VI-VI of FIG.

FIG. 7 is a VII-VII arrow view of FIG. 1, and a dotted portion is a contact surface with the crankcase.

FIG. 8 is a view on arrow VIII-VIII in FIG.

FIG. 9 is a vertical sectional front view of a cylinder block.

10 is a cross-sectional plan view cut along the line XX of FIG.

FIG. 11 is a view taken along the line XI-XI in FIG.

FIG. 12 is a diagram illustrating a state of 45 ° before top dead center (TDC).

FIG. 13 is a diagram illustrating a state of 45 ° after top dead center (TDC).

FIG. 14 is a diagram illustrating a state of bottom dead center (BDC).

FIG. 15 is a diagram illustrating a state of 90 ° before top dead center (TDC).

FIG. 16 is an explanatory diagram illustrating an operation cycle of the present embodiment.

FIG. 17 is a vertical sectional side view of the second embodiment of the present invention.

18 is a cross-sectional plan view cut along the line XVIII-XVIII in FIG.

FIG. 19 is an enlarged view of a main part of FIG.

FIG. 20 is a schematic vertical sectional side view showing a power transmission mechanism between the crankshaft and the rotary valve of the embodiment of FIG. 17.

21 is a partial vertical cross-sectional view of the rotary valve of the embodiment of FIG.

FIG. 22 is a vertical sectional side view cut along the line XXII-XXII in FIG. 21.

FIG. 23 is a vertical sectional side view cut along the line XXIII-XXIII in FIG. 21.

FIG. 24 is an explanatory diagram illustrating an operation cycle of the embodiment of FIG.

FIG. 25 is a plan view of a cylinder block according to a third embodiment of the present invention.

FIG. 26 is a vertical sectional side view cut along the line XXVI-XXVI in FIG. 25, showing a state in which a lid is attached.

27 is a cross-sectional plan view cut along the line XXVII-XXVII in FIG. 26, showing the state in which the lid is removed.

FIG. 28 is a vertical sectional side view cut along the line XXVIII-XXVIII in FIG. 26.

FIG. 29 is a partial vertical cross-sectional view of the rotary valve of the embodiment of FIG. 25.

FIG. 30 is a diagram illustrating a state at the time of compression, air chamber filling, and intake of the embodiment of FIG. 25.

FIG. 31 is a view showing a state of the same expansion.

FIG. 32 is a diagram illustrating a state at the time of fuel injection / exhaust / scavenging.

FIG. 33 is a diagram illustrating a state at the time of exhaust, mixture supply, and intake.

FIG. 34 is an explanatory diagram illustrating the operation cycle of the embodiment of FIG. 25.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spark ignition type 2 cycle internal combustion engine, 2 ... Crankcase, 3 ... Cylinder block, 4 ... Cylinder head, 5 ...
Cylinder hole, 6 ... Piston, 7 ... Connecting rod, 8 ... Crank shaft, 9 ... Crank chamber, 10 ... Intake passage, 11 ... Throttle valve, 12 ... Reed valve, 13 ... Combustion chamber, 14, 15 ... Air supply scavenging air Passages, 16, 17 ... Scavenging openings, 18 ... Scavenging passages for supplying rich mixture, 19 ... Scavenging openings, 20 ... Valve storage holes, 21 ... Exhaust passages, 22 ...
Exhaust opening, 23 ... Spark plug, 24 ... Air passage, 25 ... Air introduction groove, 26 ... Reed valve, 27 ... Partition wall, 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 ... Shift gear group, 51 ... Drive gear, 52 ... Driven gear, 53
… Chain sprocket, 54… Balancer weight, 55… Balancer gear, 56… Drive gear, 57,58… Drive gear, 59… Oil pump, 60… Drive shaft, 61… Drive gear, 62… Intermediate gear, 63,64… Oil supply passage, 65 ... Water pump, 66 ... Rotating shaft, 67 ... Driven gear, 68 ... Cooling water passage, 69 ... Balancer shaft, 70 ... Air passage, 71 ... Suction opening, 72 ... Jet opening, 73
... scavenging passage for supplying rich mixture, 74 ... ejection opening, 75 ... suction opening, 76 ... rotary valve, 77 ... notch, 78 ... notch, 79 ... pulley, 80 ... pulley, 81 ... cog belt, 82 ... valve storage Hole, 83 ...
Fuel injection valve, 84 ... Fuel injection valve, 86 ... Communication passage, 87 ... Opening,
88 ... Opening, 89 ... Rotating valve, 90 ... Notch, 91 ... Valve storage hole, 92
… Fuel injection valve mounting hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichi Isomura 1-4-1 Chuo, Wako-shi, Saitama Inside Honda R & D Co., Ltd. (72) Inventor Hideki Noritake 1-4-1 Chuo, Wako, Saitama Incorporated Honda Technical Research Institute (72) Inventor Masami Takubo 1-4-1 Chuo, Wako, Saitama Incorporated Honda Technical Research Institute

Claims (6)

[Claims] 1. A control valve for controlling the communication passage to open and close is provided in a communication passage between the combustion chamber and a chamber connected to the fuel injection device, and fuel is supplied to the combustion chamber through the communication passage. In a two-cycle internal combustion engine for supplying, the chambers are arranged side by side in the combustion chamber,
A two-cycle internal combustion engine, wherein at least a control portion of the control valve is provided below a connection portion with the chamber. 2. The control valve connects the communication passage near the time when the scavenging opening is closed after the bottom dead center of the engine, and closes the communication passage during the compression process after closing the exhaust opening. The two-cycle internal combustion engine according to claim 1. 3. The two-stroke internal combustion engine according to claim 1, wherein the control valve is a rotary valve that rotates in association with rotation of a crankshaft of the engine. 4. The chamber communicates with a crank chamber of the engine, and the communication portion is provided with a sluice valve that communicates the chamber with the crank chamber only during an exhaust process of the engine. A two-cycle internal combustion engine according to any one of claims 1 to 3, wherein 5. The communication passage comprises a first communication passage through which highly compressed air flows from the combustion chamber to the chamber, and a second communication passage through which a mixture gas flows from the chamber to the combustion chamber. The first control valve provided in the communication passage connects the first communication passage near the time when the exhaust opening is closed, closes the first communication passage during the compression process, and is provided in the second communication passage. The second control valve is configured to connect the second communication passage when the scavenging opening is closed, and close the second communication passage before the first communication passage is closed during the compression process. A two-cycle internal combustion engine according to any one of claims 1 to 3. 6. The first communication passage and the second communication passage,
The two-stroke internal combustion engine according to claim 5, wherein the two-stroke internal combustion engine has a common communication passage.