Hydraulic lash adjuster

摘要

A hydraulic lash adjuster for an internal combustion engine is disclosed. The hydraulic lash adjuster includes a low-pressure chamber defined in the plunger and filled with a hydraulic fluid and a high-pressure chamber filled with hydraulic fluid defined in a lower interior of the cylinder and partitioned by the bottom wall of the plunger from the low-pressure chamber. A valve port is formed through the bottom wall of the plunger so as to communicate with both the low-pressure and high-pressure chambers. The valve port has at the high-pressure chamber side an opening edge formed with a valve seat face. A valve element is provided in the high-pressure chamber so as to abut and depart from the valve seat face, thereby closing and opening the valve port. The valve element is made of a material having a specific gravity smaller than steel.