| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an automatic tensioner with an active damping mechanism. SOLUTION: The automatic tensioner provided with an arm 2 pivotably supported on a mount 1 and a tensioned pulley 5 rotatably supported on a tip portion of the arm 2, is provided with a hydraulic damper 8 which is provided with a cylinder body 9 connected to an engine, a piston 12 inserted into the cylinder body 9 and a rod 13 which is fixed and connected to the piston 12 and is connected the arm 2, and the cylinder body 9 is partitioned into two chambers 10, 11, into which magnetorheological fluids MRF is filled, by means of the piston 12, and both of the two chamber 10, 11 are in fluid communication with each other by communicating passage 15, and magnetic force is applied to the magnetorheological fluids MRF in the communicating passage 15 from outside cylinder body 9 by a electromagnet 16. The oscillation of the arm 2 is dampened by resistance of fluid path of the magnetorheological fluids passing through the communicating passage 15 in accordance with its oscillation and the resistance of fluid path of magnetorheological fluids MRF in the communicating passage 15 is varied by change in magnetic force and thus dampen force is variable.</p> |
