Patent ID: 7875009

Claim:
A fluid control device, comprising: a first fluid path and a second fluid path each having a hollow shape; a housing portion formed between said first fluid path and said second fluid path and having a hollow portion with a cross sectional area larger than those of said first and second fluid paths; and a valve member mounted at an opening portion at which said first fluid path communicates with said hollow portion, the valve member having a body and a projection portion formed of an elastic material, wherein the body of said valve member is formed of a cylindrical member which can be inserted into said first fluid path, the cylindrical member including a side portion having at least one communication portion to allow a fluid flow from the first fluid path to the hollow portion, wherein said projection portion is formed at a tip end portion of said cylindrical member on the side of the hollow portion, and is configured to project towards an inner wall face of said housing portion and have on an inner side of the body a hollow cavity portion which communicates with said communication portion, wherein at least a part of an outer edge portion of said hollow cavity portion sits on an inner wall face of said housing portion to close the fluid flow from the first fluid path to said hollow portion below a predetermined fluid pressure, and allow the foregoing fluid flow above a predetermined fluid pressure, wherein a cavity shape of the hollow portion on a second-fluid-path side is of an approximately-circular cone having a diameter which is successively reduced from the first-fluid-path side toward the second-fluid-path side, wherein mutually engageable engaging portions are provided in the first fluid path and in an end portion of the valve member on a side opposite to the projection portion, and wherein the valve member is located in the first fluid path, so that an engagement of said mutually engageable engaging portions cause the valve member to be placed under a tension in a lengthwise direction in the first fluid path.