This invention is concerned with an intake/exhaust air pressure balancer connected to an intake system which induces the mixture of air and fuel or the air into a cylinder and to an exhaust system which draws off the combustion gas expanded in a cylinder to the environment, and a method of reducing resistance built up in the process of internal combustion engine cycles for automobiles or heavily equipped vehicles.
In general, operational cycles of an internal combustion engine are composed of an intake stroke inducing the mixture of air and fuel into a cylinder in case of a carburetor-type internal combustion engine, or the air into a cylinder or an intake manifold in case of an injection-type internal combustion engine; a compression stroke compressing the intaken mixture or air (hereinafter referred to as "intaken air"); and an explosion stroke which enables instant explosion of the compressed mixture of air and fuel, or the air, upon applying electric ignition at a proper time near the end of the compression stroke, or upon spraying fuel onto the compressed air, respectively, because of ignition and combustion of the fuel therein. When fuel is instantly ignited and exploded, the intaken air in a cylinder is rapidly expanded; this rapidly expanded combustion gas moves a piston to transform heat energy into mechanical energy; and at the end of the expansion stroke, an exhaust valve is open to draw off the gas in the cylinder to the environment through an exhaust manifold and an exhaust pipe, and this process is an exhaust stroke. This stage is connected to the next intake stroke, and these whole stages are repeated in cycle.
Among the operational cycles of the above internal combustion engine, during an intake stroke inducing the gas into a cylinder, if a crank shaft is rotated, the piston is lowered in the cylinder, and an inlet valve is open thus making the inside of the cylinder in a vacuum state. Due to this vacuum power, a negative pressure is built in the intake apparatus, and the intaken air induced through an air-cleaner or a carburetor is sucked into each cylinder through an intake manifold and then an open intake valve.
Therefore, in the intake stroke described in the above, due to the vacuum power in the cylinder, the intaken air is rapidly and strongly sucked into the inside of the cylinder through the intake manifold; if an intake valve is closed at the end of an intake stroke, the intaken air being sucked with a strong suction power is then collided to a closed intake valve and reflected; and the intaken air thus reflected and flowed out in an opposite direction is then reversely flowed toward the intake manifold and collided with the intaken air which is being induced constantly. This collision creates a great deal of resistance and interference with the intaken air which has been flowed in at the next intake stroke as well as loud noise, thus reducing the power of an internal combustion engine.
Thus, in order to avoid interference and resistance inherent to the intaken air at the stage of an intake stroke, in the past, the spacial interval between a cylinder for the intake stroke and that for the next intake stroke has been left as widely as possible and a large space for the intake manifold has been allowed to increase the volume of the intaken air. However, this method had been proved to be a failure because there was an increase in resistance in proportion to the quantity of the intaken air reversely flowed out.
Further, among the operational cycles of the internal combustion engine, during an exhaust stroke, the gas exhausted through an exhaust equipment was subject to heavy vibration due to a rapid expansion of the gas resulting from changes in the combustion pressure and quantity of the flowed air under high temperature and high pressure. In order to minimize vibration due to such rapid overexpansion of the exhausted gas, in the past, a method of reducing pumping loss (intake loss+exhaust loss) by attempting to decrease resistance in the exhaust path and thus allowing a smooth expansion of the gas, and of installing a muffler to reduce noise, had been employed.
However, in spite of such attempts to improve an exhaust equipment, it has not been possible to resolve problems of heavy noise and low engine power coming from vibrations inherent to the engine due to bending of the exhaust manifold and exhaust pipe and due to suspension system of the exhaust pipe as well as vibration inherent to road surfaces.