Check valve device

1. A check valve device comprising:

a body having a fluid passage communicating with a first port and a second port;

a valve plug arranged in said fluid passage of said body, said valve plug being in a valve-opened state when separated from a seat section, and said valve plug being in a valve-closed state when seated on said seat section; and

an elastic member arranged in said fluid passage of said body and urging said valve plug so that said valve plug is seated on said seat section,

wherein said body, said valve plug, and said elastic member are formed of resin materials, said elastic member includes a central ring member, a plurality of legs extending radially outwardly from said central ring member, said central ring member and said plurality of legs lying in a common plane, spring sections bent from ends of said legs, said spring sections being thin-walled as compared with said legs, and an annular member connected to ends of said spring sections, and said annular member installed to said valve plug is capable of approaching said legs or separating from said legs when said spring sections bend.

2. The check valve device according to claim 1 , wherein a support member of a resin material is interposed between said valve plug and said elastic member, and said support member includes an outer circumferential section, an inner circumferential section, and a plurality of intermediate sections which integrally connect said outer circumferential section and said inner circumferential section.

3. The check valve device according to claim 2 , wherein said inner circumferential section of said support member is provided displaceably in an axial direction of a valve section formed on said valve plug corresponding to said valve-opened state or said valve-closed state of said valve plug.

4. The check valve device according to claim 2 , wherein gaps are formed between said outer circumferential section and said inner circumferential section of said support member, and a pressure fluid flows through said gaps when said valve plug is in said valve-opened state.

5. The check valve device according to claim 1 , wherein said body includes a first valve block and a second valve block which are coupled to one another by a ring-shaped nut member.

6. The check valve device according to claim 5 , wherein said valve plug includes an annular section interposed between said first valve block and said second valve block, a substantially columnar valve section arranged at a central portion of said annular section, and a plurality of thin-walled sections separated from each other by predetermined angles in a circumferential direction for connecting said annular section and said valve section.

7. The check valve device according to claim 6 , wherein gaps are formed between said adjoining thin-walled sections, and a pressure fluid flows through said gaps when said valve plug is in said valve-opened state.

8. A check valve device comprising:

a body having a fluid passage communicating with a first port and a second port;

a valve plug arranged in said fluid passage of said body, said valve plug being in a valve-opened state when separated from a seat section, and said valve plug being in a valve-closed state when seated on said seat section; and

an elastic member arranged in said fluid passage of said body and urging said valve plug so that said valve plug is seated on said seat section,

wherein said body, said valve plug, and said elastic member are formed of resin materials, said elastic member includes a plurality of legs, spring sections bent from ends of said legs, and an annular member connected to ends of said spring sections, and said annular member installed to said valve plug is capable of approaching said legs or separating from said legs when said spring sections bend, and

wherein a support member of a resin material is interposed between said valve plug and said elastic member, and said support member includes an outer circumferential section, an inner circumferential section, and a plurality of intermediate sections which integrally connect said outer circumferential section and said inner circumferential section.

9. The check valve device according to claim 8 , wherein said inner circumferential section of said support member is provided displaceably in an axial direction of a valve section formed on said valve plug corresponding to said valve-opened state or said valve-closed state of said valve plug.

10. The check valve device according to claim 8 , wherein gaps are formed between maid outer circumferential section and said inner circumferential section of said support member, and a pressure fluid flows through said gaps when said valve plug is in said valve-opened state.

11. The check valve device according to claim 8 , wherein said body includes a first valve block and a second valve block which are coupled to one another by a ring-shaped nut member.

12. The check valve device according to claim 11 , wherein said valve plug includes an annular section interposed between said first valve block and said second valve block, a substantially columnar valve section arranged at a central portion of said annular section, and a plurality of thin-walled sections separated from each other by predetermined angles in a circumferential direction for connecting said annular section and said valve section.

13. The check valve device according to claim 12 , wherein gaps are formed between said adjoining thin-walled sections, and a pressure fluid flows through said gaps when said valve plug is in said valve-opened state.