| 摘要 |
PURPOSE:To give the specified tension to a crawler, by letting pressure oil, making an operating part go up and down, operate on an idler pushing hydraulic cylinder. CONSTITUTION:When a selector valve 17 is operated, pressure oil in a hydraulic pump 19 is fed to a reaping part lifting hydraulic cylinder 15 as well as fed to an idler pushing hydraulic cylinder 12 via a check valve 13, making an idler 9 move in its tension direction. And, when a reaping part goes up to the full and the hydraulic cylinder 15 extends as far as its stroke end, the pressure oil is relieved at a relief valve 21, whereby relief pressure consisting of the specified high pressure is fed to the idler pushing hydraulic cylinder 12. With this constitution, the idler 9 give its fixed pressing force to a crawler. |
