Abstract: A valve rocker cover is securely mounted on a cylinder head of an internal combustion engine. The valve rocker cover includes a rocker cover main body made of a plastic and of a generally upturned vessel shape so as to be opened at its bottom end. The main body includes a roof section which is formed with a plurality of openings through which metal pipe members extending from the cylinder head are respectively disposed. A plurality of annular oil seal members are disposed coaxial respectively with the openings and made of an elastomeric material. The annular inward lip section of each seal member is in contact with the metal pipe member. A plurality of annular support members for the oil seal members are disposed coaxial respectively with the openings and made of a plastic. The annular outward section of the oil seal member is fixedly secured to the inner peripheral portion of each annular support member.

Abstract: A vent control valve for controlling fuel vapor flow from a fuel tank to a vapor storage canister during fuel supply to the fuel tank. The vent control valve is fixedly attached to a fuel filler tube and formed therein with first and second chambers. The first and second chambers are located side by side on an immaginary plane along the fuel filler tube. The first and second chambers are communicated respectively with the fuel tank and the vapor storage canister. A valve mechanism is provided between the first and second chambers and adapted to cause the first and second chambers to communicate with each other so as to allow fuel vapor in the fuel tank to flow into the vapor storage canister, when opened. The valve mechanism is opened when a fuel supply gun is inserted into the fuel filler tube to supply fuel into the fuel tank.

Abstract: A gas flow rate control system for controlling the flow rate of blow-by gas to be recirculated back to the combustion chamber in an internal combustion engine. The gas flow rate control system comprises a PCV valve disposed in a gas flow passage through which blow-by gas flows in the direction of the engine combustion chamber. A bypass passage is formed in such a manner as to connect the upstream side and the downstream side of the flow control section of the control valve in the gas flow passage. A bypass control valve is disposed in the bypass passage to control the flow of blow-by gas through the bypass passage in response to an engine operating parameter such as intake manifold vacuum, thereby compensating the control characteristics of the PCV valve in order to achieve precise control of the amount of recirculated blow-by gas in accordance with engine operating conditions.