| 摘要 |
PURPOSE: A fireproof door-closer is provided to prevent the diffusion of fire and smoke rapidly by closing a door with strong force and close a fireproof door automatically in higher temperature than predetermined temperature without additional manipulations. CONSTITUTION: A fireproof door-closer is composed as follows. When a piston(20) is moved forward, a flow hole formed in a body part(10) is obstructed by the piston. An auxiliary check valve is installed in one side of the piston additionally and composed to move working fluid in a rear chamber of a cylinder(10b) to the front chamber of a cylinder(10a) by being opened. Flow passages formed in the body part is formed as a flow passage for general use(11) and a flow passage for fire prevention(12). The flow passage for fire prevention is closed by a fireproof valve(70) usually and opened by a fuse at a fire. |
