ACCUMULATOR USING INTERNAL AND EXTERNAL THREADS

摘要

An accumulator (ACC) in which a container main body(1) and a closure member (5) are screw-joined together. A reverse-buttress internal thread or an internal thread having an included angle of 90 degrees is used as an internal thread of the screw-joined portion. The reverse-buttress internal thread is formed in such a way that the inclination angle ( beta ) of a clearance flank of the buttress internal thread is the inclination angle ( beta ) of a reverse pressure flank (20A) receiving a load, the inclination angle (&thetas;) of a pressure flank is the inclination angle (&thetas;) of a reverse clearance flank (2B). The internal thread having an included angle of 90 degrees is formed in such a way that inclination angles ( alpha ), ( gamma ) of both flanks are equal and the included angle ( delta ) is about 90 degrees.