The present invention relates to a valve mechanism, particularly to a valve mechanism which can be used for a tube-type fluid container.
As this type of valve mechanism, for example, as described in Japanese Patent Laid-open No. 2001-179139, a valve mechanism having a spherical valve body and a spring for giving momentum to the valve body toward a valve seat has been used. Manufacturing costs of the valve mechanism using the spherical valve body and the spring, however, tend to be high.
Consequently, a valve mechanism having a resinous valve seat, and a resinous valve body which moves between a closed position in which the valve body contacts the valve seat and an open position in which the valve body separates from the valve seat is commonly used.
In the resinous valve mechanism, it is preferred that the valve mechanism has a simple configuration which can close a fluid flow reliably. Additionally, it is preferred that the configuration can alter a flow rate of the fluid passing through the valve mechanism discretionally according to a pressure applied to the fluid. As matters stand, however, a valve mechanism satisfying these requirements is not reported.