| 摘要 |
<p>PROBLEM TO BE SOLVED: To additionally switch to a central intermediate position for a delay position (basic opening/closing period) and an early position (rotation moment position), by immovably fixing a first hydraulic piston to the central position by an adjusting device. SOLUTION: A compression spring 17 loaded with a bias is provided in a hollow chamber 16 between a first hydraulic piston 14 and a second hydraulic piston 15, and an adjusting device 19 is built in and arranged in a casing 18. The first hydraulic piston 14 is immovably positioned, by this adjusting device 19, at central positions MS and D, namely rotation moment positions optimized between a delay position (basic opening/closing period) and an early position (rotation moment position). Thus, a fluid pressure and the compression spring 17 that is always loaded between the first and second hydraulic pistons 14, 15 can ensure tension defined by a chain in the directions of a load part 6 and a loose part 7.</p> |
