| 摘要 |
PURPOSE: A valve opening and closing device is provided to prevent the deformation of a rotation angle by setting the rotation angle of a rotary angle. CONSTITUTION: A valve opening and closing device comprises a housing(10), a rotating unit(20), a plurality of piston unit(30), a plurality of finished units(40) and a pressure hole(12). A through hole(11) is formed on the housing. The rotating unit is installed on the center of the through hole to rotate. A plurality of finished units finishes the both ends of the through hole. The pressure hole is formed to pass through the through hole of the housing.
|
