Patent ID: 9227614
Filing Date: 2016-01-05
CPC Classification: B60T,F16K,Y10T

Claim Text:
1. A check valve comprising: a case member having an entrance-side fluid passage where fluid flows in, an exit-side fluid passage where fluid flows out, and a valve seat disposed in a downstream end of the entrance-side fluid passage; a pipeline disposed in a housing, the pipeline being separated into a downstream side pipeline of the check valve and an upstream side pipeline of the check valve by the case member; a valve member that opens and closes a passage between the entrance-side fluid passage and the exit-side fluid passages by touching and separating from the valve seat, and is energized in a valve opening direction by a pressure of the fluid from the entrance-side fluid passage; and a spring that energizes the valve member in a valve closing direction; wherein, the check valve opens when the energization force in the valve opening direction due to the pressure exceeds the energization force in the valve closing direction due to the spring; wherein, the valve member has a piston part that reciprocates, and a valve part that is disposed in the valve seat side and touches and separates to the valve seat; the case member has a piston accommodation cylinder part that accommodates the piston part reciprocatably; the piston part has a valve part accommodating recess that accommodates a part of the valve part; the valve part is disposed in the valve part accommodating recess movably relative to the piston part, and is urged against a wall surface of the valve part accommodating recess by a pressure of the fluid from the entrance-side fluid passage; among the valve part accommodating recess, an anti-valve seat side accommodation space formed between a surface in an anti-valve seat side of the valve part and a wall surface of the valve part accommodating recess communicates to the exit side fluid passage. a damper chamber is formed by the valve member and the case member in an anti-valve seat side of the valve member, the damper chamber generates damping force; the anti-valve seat side accommodation space communicates with the exit side fluid passage through a piston part communicating slot formed in the wall surface of the valve part accommodating recess; the valve part accommodating recess has a tapered surface, and the valve part is contactable to the tapered surface, the anti-valve seat side accommodation space is formed between the piston part and the valve part; and the piston accommodation cylinder part is formed coaxially with the entrance-side fluid passage, and only a single through hole extending in a radial direction is formed in the piston accommodation cylinder part.