JPH0243009B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a kind of rotary pipe valve structure for a two-stroke gasoline engine, especially a kind of rotary pipe valve structure that rotates synchronously with the crankshaft (same direction or opposite direction). Refers to a rotary valve device, which uses the opening on the rotary valve to sometimes match with the two passages above the valve seat to compress the air into the rotary valve. Compressed air passes through two passages above the valve seat and is injected into the exhaust port or crankshaft box. This prevents fresh air from leaking out, and also eliminates fresh air inside the cylinder. It is also possible to increase the pressure of the scavenging air flow, thereby increasing the intake and exhaust efficiency of a two-stroke gasoline engine.

[Conventional technology]

Two-stroke gasoline engines have advantages such as simple structure, low manufacturing cost, easy maintenance, and stable output.
At the same time, engines have disadvantages such as fuel consumption and high exhaust pollution, which must be solved at a time when the pressure for energy conservation and environmental protection is increasing today.

The main reason for the above-mentioned disadvantages such as fuel consumption and high exhaust pollution is that during the engine exhaust process, the air-fuel mixture that partially enters the new cylinder is exhausted directly from the exhaust port together with the exhaust gas. Normally, the emissions amount to 25 to 40%.

Normally, an engine is designed with appropriate dimensions such as the length of the exhaust pipe and the expansion pipe and tapered pipe inside the exhaust pipe. It provides appropriate positive pressure and reverse pressure to the engine, promotes the removal of exhaust gas, and prevents fresh air from being exhausted from the exhaust pipe.
Matching the exhaust timing is called exhaust timing matching.The ideal relationship is that when the piston is at the lower dead point, the intake port is open and the exhaust port is in a reverse pressure state, and conversely, the intake port is closed. The exhaust port is under positive pressure during the period from when the exhaust port closes. However, since the pressure wave transfer speed (sound speed) is unrelated to the engine rotational speed, once the exhaust pipe dimensions are designed and fixed, the exhaust pressure wave has a timing adjustment effect only within a certain engine rotational speed range. However, outside the rotational speed range, the timing effect cannot be achieved, and on the contrary, it has a bad effect, for example, if the pressure wave is too early, it will interfere with the back pressure of the exhaust gas, and the gas exchange rate will be low. If it is too late, fresh air will leak out and the volumetric effect will be reduced.

[Problems in solving inventions]

The purpose of the present invention is to provide a device that prevents fresh air from leaking out from the outside of the exhaust port using jet airflow, and the jet timing is synchronized with the rotation of the engine, so timing can be synchronized with any rotational speed. It is no longer limited by exhaust pressure waves.

Another object of the present invention is to increase the pressure of the intake air of the engine using the above-mentioned injection airflow, that is, to increase the appropriate amount of air and promote combustion, thereby increasing power and reducing exhaust pollution.

Another object of the present invention is to provide a simple valve structure that synchronizes with the engine rotation to achieve the functions of increasing the pressure of the intake air of the engine using the above-mentioned injection airflow and preventing fresh air from leaking out.

In order to achieve the above-mentioned object, the present invention installs a rotary valve at a suitable position on the cylinder surface outside the engine exhaust port, and the circumferential surface of the pipe is composed of a circular pipe and a hole seat. As the pipe rotates, there is one opening in the pipe, which faces the two passages above the hole seat.The two passages are led separately to the exhaust port and crankshaft box, and the compressed air introduced into the pipe is The new air is ejected to the exhaust port via these two passages to prevent fresh air from leaking out, or it is ejected to the crankshaft box to increase the pressure of the engine's intake air. Since the rotation of the pipe is mechanically coupled to the rotation of the engine crankshaft, it is possible to adjust the jet air in conjunction with the rotation of the engine.

After the ignition of a two-stroke engine explodes, the piston is pressed down, and then the exhaust port is opened to let the high-pressure waste air in the cylinder exit from the cylinder in a natural way, and then the intake port is opened. , compressed fresh air filled in the crankshaft box enters the cylinder through the intake port to scavenge air, and also pushes low-pressure waste air to the exhaust port. When the piston rises past the lower dead point and attempts to close the intake port, the exhaust port is still open, and at this time, the opening of the rotating pipe is aligned with one of the passages (that passage is These high-speed air currents form an air curtain near the exhaust port to prevent fresh air from leaking out. Subsequently, the piston is continuously pressed upward (the rotating pipe also rotates synchronously), the exhaust port is closed, and the high-speed air jetting operation of the rotating pipe is also stopped.

As the piston continues to rise and is just short of the upper dead point, an opening in the rotary pipe valve faces yet another passage opening (which leads to the crankshaft box) and is open to the compressed air stream. Spout into the crankshaft box; when the piston passes the upper dead point, the rotary pipe valve's compressed air flow jetting operation also stops. The piston then moves downward under the action of the two-stroke engine power stroke, and this movement recompresses the compressed air filling the crankshaft box.
In this way, the intake and exhaust efficiency of the two-stroke engine can be increased.

〔Example〕

Referring to FIG. 1, FIG. 1 is a cross-sectional view of a common carburetor according to the present invention installed in a two-stroke engine that supplies air-fuel mixture. It is constructed with a crankshaft box 13 in which a piston 14, a rack 15 and a crankshaft 16 move. The crankshaft box 13 has a one-side closed air supply port 17 formed by a spring valve 171, and two sets of intake passages 191, 192 (Fig. 2A) and an exhaust port opened symmetrically to the exhaust port 181 leading to the cylinder 18. A third intake passage 193 is provided opposite to the third intake passage 193.

As is well known, during the upward movement of the piston 14, the air-fuel mixture supplied by the carburetor (not shown) is transferred from the air supply port 17 to the crankshaft by opening the spring valve 171 due to the pressure difference. Go inside box 13. At the same time, the air-fuel mixture in the cylinder 18 above the piston 14 is compressed and ignited when the piston approaches the upper dead point, generating power and pushing the piston downward.
1 is closed, the high-pressure waste air in the cylinder 18 is opened to the exhaust port 1, in which the air-fuel mixture in the crankshaft box 13 is precompressed by the lowering of the piston 14.
When 81 is exposed, it is immediately discharged, and then each intake passage 191, 192, 193 is exposed one after another,
The pre-pressurized air-fuel mixture in the crankshaft box 183 enters the cylinder 18 and pushes low-pressure waste air to the exhaust port 181. After the piston 14 has passed the lower dead point, when it rises again and attempts to close the intake passages 191, 192, 193 one after another, the exhaust port 181 is still open, and at this time, the intake and Due to the flow inertia of the exhaust gas and the rise of the piston 14, the space inside the cylinder 18 is reduced, so that fresh air is easily followed by the exhaust gas and leaks from the exhaust port 181, resulting in wasted gasoline consumption and pollution. To increase.

Therefore, the present invention provides a compressed air injection device to inject a powerful air stream to the exhaust port 181 at the end of the exhaust timing to form an air curtain.
It stops fresh air from leaking out; it goes one step further and blows excess air into the cylinder 18 and crankshaft box 13 at the appropriate time to increase the pressure of the intake air. The best embodiment of this is to install one rotary pipe valve 2 in the cylinder body 12 at an appropriate position near the exhaust port 181, and use one circular pipe 21 to connect the circular hole seat 2 in the cylinder body 12.
It is composed by setting it within 0. hole seat 20
A first passage 20 communicating with the exhaust port 181 on the circumferential surface
1 and a second passage 202 communicating with the crankshaft box, the interior of the pipe 21 is connected to a source of compressed air (not shown) and is connected to a compressed air source (not shown).
Only when the elongated opening 211 opened on the circumferential surface of the cylinder 1 faces the two passages 201 and 202 and blows air into the exhaust port 181 or the crankshaft box,
The compressed air is trapped inside the pipe 21 at other times when the compressed air is released, the rotation of the pipe 21 is synchronous with the rotation of the crankshaft 16, and the method is well known such as gears, belts, chains, etc. The opening 211 and the passage 20 can be achieved by simply connecting the two with an interlocking device.
By designing a suitable correlation position between 1 and 202, the timing of the jet air is matched with the end of exhaust of the cylinder 18 and the end of air supply of the crankshaft box 13, and this structure and effect can be achieved again in the second stage.
Explanations will be added in the order of operation from A to 2D diagrams. In these figures, the pipe 21 is in synchronous and reverse connection with the crankshaft 16.

In FIG. 2A, the piston 14 is located at the lower dead point, and the exhaust port 181 and each intake passage 1
91, 192, 193 are all open,
Most of the waste air in the cylinder 18 is discharged through the exhaust port 181, before the pipe valve opening 211 reaches the position of the first passage 201.

Subsequently, the piston 14 moves upward and the second
At the timing shown in Figure B, each intake passage 193 etc. is closed, but the exhaust port 181 is not completely closed. At this time, the pipe opening 211
is opposed to the first passage 201 and ejects fumes to the exhaust port 181 in the direction shown by arrow b.
It is possible to stop the fresh air leaking from the cylinder 18, and also to blow the air back into the cylinder 18.
The pressure of the air-fuel mixture in the air-fuel mixture can be increased, thereby promoting complete combustion when the air-fuel mixture is combusted, thereby increasing output and reducing exhaust pollution.

Of course, the jet strength is determined by the cross-sectional area of the opening 211 and the pressure of the compressed air source; this strength is determined by the fact that the pressure of the mixture exiting the cylinder 18 is sufficiently large; and the jet timing is determined by the fact that the opening 211 This timing is determined by the time of passage, and this timing is determined by the time when the intake passage is closed and the exhaust port 1 is closed.
81 should be closed, and such factors can be appropriately adjusted in the design to obtain the optimum effect. Generally speaking, a source of compressed air can set a stable pressure or can be modulated depending on the engine speed, e.g. increasing the pressure at high speeds and increasing the pressure at low speeds. Supply of these air sources, such as reduction, can be achieved using common techniques, so redundant explanation will be omitted here.

Regarding the airflow injected toward the exhaust port 181,
The airflow remaining outside the exhaust port after the exhaust port closes can also be used at the beginning of the engine's next exhaust stroke, as the partially incompletely combusted air-fuel mixture is mixed into the hot waste air blown out by the exhaust port. It continuously oxidizes to carbon dioxide and water vapor, taking one step further in reducing waste air pollution.

FIG. 2C shows the situation after the exhaust port has emitted fumes. The pipe valve 2 has just rotated and closed, and the piston 14 closes the exhaust port 181 and moves upward to create a mixture inside the cylinder 18. Compress the air. At the same time, the volume of the crankshaft box 13 increases and air is introduced from the air supply port 17.

By the time shown in FIG. 2D, the piston 14 has reached the upper dead point and is in the process of combustion explosion in the cylinder 18, and at this time the volume of the crankshaft box 13 has increased to its maximum, and the air supply port 1
7, the pipe valve opening 211 directly faces the second passage 202, and the compressed air is injected into the crankshaft box 13 as shown by arrow d, thereby starting the crankshaft box 13. increasing the pressure of the air-fuel mixture in the shaft box 13;
Thereby, the air-fuel mixture can be quickly drawn into the cylinder 18, and the low-pressure waste gas remaining in the cylinder 18 can be quickly discharged. in this way,
Since air-fuel mixture can be taken in quickly and low-pressure exhaust gas can be discharged quickly, it can sufficiently handle even high-speed engine rotations. Of course, the control of the amount of jet and the timing of the jet can be adjusted during design depending on factors such as the cutting area of the opening 211, the pressure difference between the compressed air source and the crankshaft box 13, and the opening/closing timing of the opening 211 versus the passage 202. .

After the timing of FIG. 2D is over, the piston 14 is moved downward by the power generated from the combustion explosion, and as it goes through the exhaust and intake processes, the cycle is completed as shown in FIG. 2A. continue to cycle.

Although the above operating situation has been explained with reference to a two-stroke engine that uses an air-fuel mixture mixed with gasoline before entering the crankshaft box, the present invention can actually be used in any type of two-stroke engine, such as a jet engine. This is a jet-type oil injection engine that supplies fresh air to the crankshaft box by supplying oil into the cylinder with a type oil injection device. The present invention is particularly applicable to such jet-type oil injection engines, because the mixture concentration can be elastically controlled, and by adding the intake pressure boosting effect of the present invention, the engine can achieve maximum efficiency. can.

FIG. 3 shows the rotary pipe valve 2 according to the present invention.
2 is a cross-sectional view of a two-stroke engine 5 with jet oil injection installed in the cylinder. The engine 5 has roughly the same structure as the engine shown in FIG.
Air supply port 57, spring valve 571, cylinder 58, exhaust port 581, intake path 591, 592
(not shown) and 593. However, the fuel for the engine is supplied into the cylinder 58 by one jet type oil injector 6, and one of the most suitable systems is to provide one vaporization chamber 541 inside the piston 54, as shown in the figure. The fuel is first injected into the vaporization chamber 541, which opens toward the third intake passage 593 and in the direction of the oil injection device 6, absorbs high heat on the piston and vaporizes, and after vaporization, Stored in the third intake passage 593 for a while,
The air drawn back into the cylinder and admitted or pre-pressurized from the crankshaft box 53 is simply fresh air. This design can lower the temperature of the piston, which will increase the combustion efficiency of the engine (as the combustion efficiency increases, the engine temperature will increase, and in ordinary engines, when the heat dissipation of the piston is not good, it will burn out). ), therefore, using it together with the present invention has the effect of killing two birds with one stone. Regarding the configuration of the rotary valve 2, the hole seat 20, passages 201, 2
02, the movement combination situation of the pipe 21, the opening 211, and the piston 54 is the same as that of the above-mentioned 2A to 2.
This is the same as the explanation up to Figure D.

Furthermore, although only a single engine is depicted in the above-mentioned drawings, in reality, the present invention can be applied to a multi-cylinder engine, in which the pipes 21 can be inserted through a plurality of cylinders, and a plurality of openings 211 can be installed on the pipes 21. The above function can be achieved by installing the first and second passages 201 and 202 individually to match each cylinder.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the structure of the present invention, which is installed in a two-stroke gasoline/air premix engine. Figures 2A to 2D are functional explanatory diagrams of the present invention, showing the present invention and its engine in four different positions during continuous rotation.
Fig. 2A therein shows the piston positioned at the lower dead point; Fig. 2B shows the situation in which the present invention blows into the exhaust port following Fig. 2A; Fig. 2C is Fig. 2B. 2D is a situation in which the piston is at the upper dead point and the invention is injecting into the crankshaft box. FIG. 3 is a cross-sectional view of the structure of the present invention installed in a two-stroke jet oil injection engine.

Claims (1)

[Scope of Claims] 1. A cylindrical hole seat provided with at least two or more passages that communicate separately with a two-stroke gasoline engine, an exhaust port, and a crankshaft box;
A cylindrical pipe is housed in the hole seat and has an opening formed in the peripheral wall, and the pipe is rotatably housed in the hole seat and the outer peripheral wall of the pipe and the inner peripheral wall of the hole seat are connected to each other. The pipe is housed in an airtight manner, and one end of this pipe is connected to a compressed air source that supplies compressed air into the pipe, and the opening of the pipe is connected to a hole in the exhaust gas at the end of the exhaust stroke of a two-stroke gasoline engine. communicates with the mouth passage,
and a rotating means for adjusting the rotation of the pipe in conjunction with the rotation of the crankshaft so that the opening of the pipe communicates with the crankshaft box side passage of the hole seat at the end of the compression stroke. A rotary pipe valve structure for a two-stroke gasoline engine.