| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic automatic tensioner for preventing a push rod from being pushed in by pushing force from a belt, when stopping an engine. SOLUTION: An upper opening of a cylinder 11 is sealed by incorporation of a seal member 14, and pressing force of a return spring 18 is applied to the push rod 16 of slidably penetrating through the seal member. A nut member 30 is incorporated into an upper side position than the seal member of the cylinder, and a male screw 34 formed on the outer periphery of a screw rod 33 is engaged by a screw with a female screw 32 formed on the inner periphery of the nut member. The female screw and the male screw are formed as a sawtooth-shaped screw larger than a crank angle of a play side crank in a pressure side crank for receiving the pushing force applied to the screw rod, and a screw clearance in the axial direction is arranged between screw engaging parts of the sawtooth-shaped screw, and when the pushing force is applied to the screw rod from the belt, the pressure side cranks of the female screw and the male screw are mutually contacted, and the screw rod is locked by frictional resistance acting on its contact part. COPYRIGHT: (C)2011,JPO&INPIT
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