| 摘要 |
A door closer having a simple structure. The door closer has a stationary shaft (10) and a tubular housing (20) fixed to a door. In the housing (20) are received a non-rotatable piston (80); an inner communication path (83) provided with a check valve (84) and interconnecting a high-pressure oil chamber (81) and a low-pressure oil chamber (82) that are located on both sides of the piston (80); outer communication paths (102, 104) which, when the piston (80) moves from the low-pressure oil chamber (82) side to the high-pressure oil chamber (81) side, allows oil in the high-pressure oil chamber (81) to flow to the low-pressure oil chamber (82) side; a high-pressure-side cam member (91); and a low-pressure-side cam member (96). When the door becomes opened to rotate the housing (20), the high-pressure-side cam member (91) pushes out the piston (80) from the high-pressure oil chamber (81) side to the low-pressure oil chamber (82) side. Further, when the door becomes rotated in a closing direction, the low-pressure-side cam member (96) pushes out the piston (80) from the low-pressure oil chamber (82) side to the high-pressure oil chamber (81) side. |
