A plunger ( 45 ) and a piston ( 46 ) are displaceably held in a housing ( 104 ) for opening and closing a valve path ( 107 ) defined in the housing ( 104 ), and a single common seat block ( 44 ) provided for the plunger ( 45 ) and the piston ( 46 ) is fixed to the housing ( 104 ) and has seat portions ( 47 ) each formed from a soft material for respective of the plunger ( 45 ) and the piston ( 46 ) to be pressed thereon. This arrangement provides a valve device which is simplified in structure and can be manufactured with reduced man-hour.
1. A valve device comprising:
a housing in which a valve path is defined;
plural valve bodies displaceably held in said housing for opening and closing said valve path; and
a single common seat block provided for said plural valve bodies and fixed to said housing for said plural valve bodies to be pressed thereon, said seat block having seat portions each comprising a soft material for said valve bodies to be pressed on respective of said seat portions, wherein:
said seat block comprises a base comprising a hard material, a first seat-forming member fitted on said base to form a first one of said seat portions, and a second seat-forming member coupled to said base to form a second one of said seat portions, each of the first and second seat-forming members comprising the soft material;
said base is fixed to said housing;
said second seat-forming member is held between said base and said housing; and
said base and said second seat-forming member provide sealing when a closed loop sharp ridge formed on said base is brought into contact with said second seat-forming member.
2. The valve device according to claim 1 , wherein:
said housing comprises plural housing members joined together; and
said seat block has a sandwiched portion and is fixed to said housing by said sandwiched portion sandwiched between said housing members.
3. The valve device according to claim 1 , wherein said seat block is fixed to said housing by thread engagement.
4. The valve device according to claim 1 , wherein said seat block is fixed to said housing by partial deformation of said housing made by caulking.
5. The valve device according to claim 1 , wherein:
the soft material is rubber or resin;
the hard material is stainless steel.
6. The valve device according to claim 5 , wherein:
said housing comprises plural housing members joined together; and
said seat block has a sandwiched portion and is fixed to said housing by said sandwiched portion sandwiched between said housing members.
7. The valve device according to claim 5 , wherein said seat block is fixed to said housing by thread engagement.
8. The valve device according to claim 5 , wherein said seat block is fixed to said housing by partial deformation of said housing made by caulking.
9. A valve device comprising:
a housing defining a valve path;
plural valve bodies displaceably disposed in the housing for opening and closing the valve path; and
a single common seat block provided for the plural valve bodies, the seat block fixed within the housing, each of the valve bodies arranged to shift between an open position spaced away from the seat block and a closed position pressed against the seat block, the seat block comprising a base and having opposed seat portions on opposite sides of the base;
a plurality of seat forming members, each seat forming member coupled to the seat block to form each seat portion, each seat forming member formed of a first material having a first stiffness;
the base of the seat block formed of a second material having a second stiffness, the second stiffness greater than the first stiffness;
at least one of the seat forming members being fitted on the base and secured between a portion of the base and a portion of the housing; and
the base and the at least one seat forming member sealed to one another at a contact surface portion, the contact surface portion including an annular ridge formed on the base and positioned to contact the at least one seat forming member.
10. The valve device of claim 9 , wherein the first material is selected from the group consisting of plastic or resin, and wherein the second material is selected from the group consisting of brass or stainless steel.