Patent ID: 6276315
Filing Date: 2001-08-21
Classification: F01L

Abstract:
A valve opening and closing mechanism for engines consisting of rocker arms which rock in proportion to actuation of cams, the rocker arms are provided with through holes at each one end, respectively, and through which push rods are inserted, and when the push rods are moved forward with respect to said rocker arms, the valves are opened against the forces by valve springs, whereas when the push rods are moved backward the valves are closed by means of the force by the valve springs, said valve opening and closing mechanism comprising:providing a circlip on the top portion of a push rod,a head of the push rod and an end of a stem of said valve are contacted, providing a displacement absorbing mechanism to absorb the displacement by means of heat expansion of said valve, the displacement absorbing mechanism being formed in the hole of the rocker arm at one end and has a tapered portion which reduces the size as it extends away from the valve, a push rod control means which is movable along the longitudinal direction of the push rod which are provided between the tapered portion and the push rod,the push rod control means actuates as a receiving part of the force of a return spring to absorb displacement due to the heat expansion of the valve, the valve spring pushes the head of the push rod toward the valve direction with a weaker force than the force by said valve spring,when the valves are opened, the push rods control means move backward with respect to the rocker arms and the push rod control means is placed between said rocker arms and push rods, the push rods are forwarded integral with said rocker arms in controlled condition,when the valves are closed, said push rods control means move forward with respect to the rocker arm and said push rods are in released condition and said rocker arm contacts said circlip and said push rods are moved backward.