JPH0478806B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention provides a combustion chamber with no intake port or exhaust port.
Regarding cycle engines.

In a conventional four-stroke engine, the intake port and exhaust port are located in the combustion chamber, so the exhaust valve that opens and closes the exhaust port will be stuck with carbon, making it impossible for it to come into close contact with the valve seat. Furthermore, since the intake valve and exhaust valve are closed by the elasticity of the valve spring, if the valve spring causes phenomena such as surging or jumping during high-speed rotation, the valve will not come into close contact with the valve seat. Therefore, as the highly compressed air-fuel mixture rotates at high speed, it leaks from the exhaust port and is discharged into the atmosphere, causing air pollution.

The present invention aims to provide a four-cycle engine in which the combustion chamber has neither an intake port nor an exhaust port in order to prevent the air-fuel mixture from escaping as described above.

Embodiments of the invention will be described below with reference to the drawings.

An intake port 2 and an exhaust port 3 are provided on the wall of the cylinder 1, and fresh air mixed by the carburetor is passed through the intake passage 4.
The exhaust gas is drawn into the cylinder 1 from the intake port 2 through the exhaust port 3, and is discharged into the atmosphere from the exhaust port 3 through the exhaust passage 5. The intake passage 4 is provided with a rotary valve 6 for opening and closing the intake passage, and the rotary valve 6 is interlocked with the crankshaft 7 and rotates once during two rotations of the crankshaft 7, so that the notch 8 of the rotary valve 6 opens and closes the intake passage. It is designed to open 4. The exhaust passage 5 is provided with a rotary valve 9 for opening and closing the exhaust passage, and the rotary valve 9 is interlocked with the crankshaft and rotates once during two rotations of the crankshaft 7, so that the notch 10 of the rotary valve 9 opens and closes the exhaust passage 5. It's starting to open.
The crank chamber 11 is sealed, and the air passage 12
An air port 13 is provided in the wall of the cylinder 1, and when the crank chamber 11 becomes negative pressure as the piston 14 rises and the air port 13 is opened, air purified by the air cleaner passes through the air passage 12. The air is sucked into the crank chamber 11 through the air port 13. An air flow control valve 17 is provided in the air passage 12, and the air flow control valve 17 is operated by hand or foot via a cable, lever, or the like. 15 is a scavenging passage, which connects the crank chamber 1
The air sucked into the cylinder 1 is compressed by the downward movement of the piston 14, and is ejected into the cylinder 1 when the scavenging port 16 is opened by the piston 14.

With the structure described above, the piston 14 begins to descend during the intake stroke, and the roller piston 14 creates a negative pressure inside the cylinder 1.
When the intake passage 4 is opened by the notch 8 of the rotary valve 6 for opening and closing the intake passage, air-fuel mixture flows into the cylinder 1 from the carburetor. piston 1
4 passes the midpoint and opens the scavenging port 16, the air in the crank chamber 11 enters the cylinder 1 through the scavenging passage 15. Since the amount of air in the crank chamber 11 corresponds to the opening degree of the air flow control valve 17, when the air-fuel mixture in the cylinder 1 is low, it is sucked into the cylinder 1 due to negative pressure, and
If there is a very small amount of air in the crank chamber 11, it will not be sucked in, and if there is a large amount of air in the crank chamber 11, it will be forced in. It is better that the air from the crank chamber 11 does not create swirls. In the compression stroke, the intake passage 4 and the exhaust passage 5 are closed by rotary valves 6 and 9, respectively, and when the piston 14 closes the intake port 2 and exhaust port 3, the compression is low, and the piston 14 closes the intake port 2 and the exhaust port 3. 3 is closed, high compression occurs, so there is no air-fuel mixture leakage at maximum compression, and blow-by is only air entering the lower side of the air-fuel mixture, and there is no air-fuel mixture. During the explosion stroke, the rotary valves 6 and 9 are protected by the piston 14 at the maximum pressure of the explosion, and when the piston 14 opens the intake port 2 and the exhaust port 3, the pressure on the rotary valves 6 and 9 is small. Therefore, since complete contact is not required, there is no friction loss in the rotary valves 6 and 9, and the unburned oil from the engine is sufficient as the lubricating oil on the exhaust side, and the air-fuel mixture passes through the suction side. Also, add oil if necessary. When the piston 14 passes the midpoint, the exhaust passage 5 is opened by the notch 10 of the rotary valve 9 and exhaust gas begins to be discharged. When the exhaust passage 5 is opened, the gas that has expanded to the maximum within the cylinder 1 is exhausted at a tremendous speed, and the pressure within the cylinder 1 instantly drops to near the back pressure within the muffler. The scavenging port 16 is the piston 1
4, the gas in cylinder 1 that has expanded to its maximum is a very small amount, and when it is cooled by fresh air from the crank chamber, it rapidly contracts, and the new air easily enters the underside of the exhaust gas in cylinder 1. As the piston 14 rises, the exhaust gas is completely exhausted, and the rotary valve 9 closes the exhaust passage 5.

The four-stroke engine of the present invention is as described above, and since the combustion chamber has neither an intake port nor an exhaust port, there is no risk of harm from carbon and the exhaust passage is reliably sealed.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an embodiment of the present invention. 1 is a cylinder, 2 is an intake port, 3 is an exhaust port, 4 is an intake passage, 5 is an exhaust passage, 6 is a rotary valve for opening and closing the intake passage, 9 is a rotary valve for opening and closing the exhaust passage, 11 is a crank chamber, 14 is a piston.

Claims (1)

[Claims] 1. It is a 4-stroke engine with no intake or exhaust port in the combustion chamber, and the crank chamber is sealed.
The cylinder wall is equipped with an intake port and an exhaust port that are opened and closed around the upper circumference of the piston, and the intake passage leading to the intake port is equipped with a rotary valve for opening and closing the intake passage that is linked to the crankshaft. A four-stroke engine characterized by being provided with a rotary valve for opening and closing an exhaust passage that is linked with a crankshaft, and an air flow control valve being provided in an air passage that opens into the crank chamber.