Patent ID: 8771118

Claim:
A chain tensioner device comprising: a main arm that has an upper end and a lower end located on an opposite end thereof, the upper end being pivotably supported by a first support shaft, wherein the main arm is brought into slide contact with an endless chain; a tensioner lifter that generates a biasing force for biasing the main arm toward the endless chain, wherein the tensioner lifter is of hydraulic type and is disposed so that a plunger protrudes upwards and an extension-and-contraction direction of the tensioner lifter is substantially in parallel with the cylinder axis of an engine cylinder, the cylinder axis of the engine cylinder spaced apart from the tension lifter, so as to apply a predetermined tension to the endless chain, the endless chain being wrapped around a drive sprocket provided on a driving shaft and a follower sprocket provided on a follower shaft; and a sub-arm that has a lower end pivotably supported by a second support shaft where the sub-arm is located between the tensioner lifter and the lower end of the main arm, the second support shaft also being located remote relative to the main arm, the sub-arm being in direct contact with the plunger of the tensioner lifter and which transfers the biasing force of the tensioner lifter to the main arm, wherein a first slide surface provided on a lower end side of the main arm and a second slide surface provided on an upper end side of the sub-arm are slidably abutted against each other to increase a stroke of the tensioner lifter and transfer the stroke to the main arm.