Patent ID: 7779805

Claim:
A sealed lash adjuster, comprising: a moving member that has a reservoir chamber filled with liquid and gas, a through-hole that extends from a sliding face of the moving member to the reservoir chamber, and a communication hole that is formed in a high-pressure-chamber-side end portion of the moving member and that permits communication between the reservoir chamber and a high-pressure chamber; a body in which the moving member is slidably housed; a fluid backflow prevention member arranged in the communication hole; and a force-applying member that is arranged in the high-pressure chamber and that applies a force to the moving member to promote protrusion of the moving member from the body, wherein the liquid is sealed in the lash adjuster so that a volume of the gas, which is present in the reservoir chamber when the lash adjuster is being produced and the moving member protrudes from the body to a fullest extent, is equal to or more than 1.24 times as great as a sum of a volume of liquid, that is discharged from the high-pressure chamber when the moving member, which has protruded from the body to the fullest extent, is moved downward to a fullest extent, and an increase in a volume of the liquid which expands, due to heat, when a temperature of the gas in the reservoir chamber changes from a production temperature that is realized when the lash adjuster is being produced to a maximum use temperature that is realized when the lash adjuster is in use; and so that a ratio of the volume of the gas present in the reservoir chamber during production of the lash adjuster to the sum is equal to or higher than a ratio that is derived, based on the production temperature and the maximum use temperature corresponding to a production environment and a use environment, from a temperature range defined by the production temperature and the maximum use temperature, which corresponds to the ratio of the volume of the gas present in the reservoir chamber during production of the lash adjuster to the sum when an inner pressure of the lash adjuster increases by 500 kPa at maximum.