| 摘要 |
PURPOSE:To avoid overtension of a wound power transmitting component, by making the titled device into structure giving a predetermined tensile state always through bouncing action of a tension spring and hydraulic pressure action of a hydraulic pressure chamber. CONSTITUTION:An automatic tension unit A fixed to a main body E of an engine possesses a plunger 26 sliding within a cylinder 25 and the plunger 26 is provided with a valve hole 31 communicating a hydraulic pressure chamber 27 and a supply oil chamber 28 with each other and a check valve 32 opening and closing the valve hole 31. A tension spring 34 arranged in the hydraulic pressure chamber 27 pushes up the plunger 26 and gives predetermined tension force to a timing chain 10 through a bell-crank lever 19 and a pressure plate 14. Although the plunger 26 is apt to be pressed downward when tensile force is acted upon the timing chain 10, the retreat of the pressure plate is controlled as the hydraulic pressure of the hydraulic pressure chamber 27 opposes against the pressure plate. A part of lubricating oil which has completed lubricating action is dropped and stored in a sump 24 communicating with the supply oil chamber 28. |
